Mass transfer parameters of celeriac during vacuum drying

NASA Astrophysics Data System (ADS)

Beigi, Mohsen

2017-04-01

An accurate prediction of moisture transfer parameters is very important for efficient mass transfer analysis, accurate modelling of drying process, and better designing of new dryers and optimization of existing drying process. The present study aimed to investigate the influence of temperature (e.g., 55, 65 and 75 °C) and chamber pressure (e.g., 0.1, 3, 7, 10, 13 and 17 kPa) on effective diffusivity and convective mass transfer coefficient of celeriac slices during vacuum drying. The obtained Biot number indicated that the moisture transfer in the celeriac slices was controlled by both internal and external resistance. The effective diffusivity obtained to be in the ranges of 7.5231 × 10-10-3.8015 × 10-9 m2 s-1. The results showed that the diffusivity increased with increasing temperature and decreasing pressure. The mass transfer coefficient values varied from 4.6789 × 10-7 to 1.0059 × 10-6 m s-1, and any increment in drying temperature and pressure caused an increment in the coefficient.

Development of a modified dry curing process for beef.

PubMed

Hayes, J E; Kenny, T A; Ward, P; Kerry, J P

2007-11-01

The development of a dry curing process using physical treatments to promote the diffusion of the cure ingredients was studied. Vacuum pulsing with and without tumbling, continuous vacuum, and tumbling only treatments were compared with a conventional static dry cure control method on beef M. supraspinatus. Vacuum tumble and tumble only treatments gave highest core salt content after 7 days conditioning (3.3% and 3.1%, respectively). All test treatments resulted in higher colour uniformity and lower % cook loss in comparison to control (P<0.001). The control and vacuum pulsed samples were tougher (P<0.001). Vacuum tumble and tumble only treatments gave higher acceptability (P<0.001). Based on these findings for M. supraspinatus, indicating that the vacuum tumble treatments gave the best results, further testing of this method was conducted using the M. biceps femoris in addition to the M. supraspinatus. Cured beef slices were stored in modified atmosphere packs (MAP) (80%N(2):20%CO(2)) for up to 28 day at 4°C. Redness (a(∗), P<0.001) decreased over storage time in M. biceps femoris. Vacuum tumble treatment increased (P<0.05) redness in M. supraspinatus. Results obtained demonstrate the benefits of vacuum tumbling over the other physical treatments as a method for accelerating the dry curing process, producing dry cured beef products with enhanced organoleptic quality and increased yields.

Drying characteristics of whole Musa AA group ‘Kluai Leb Mu Nang’ using hot air and infrared vacuum

NASA Astrophysics Data System (ADS)

Kulketwong, C.; Thungsotanon, D.; Suwanpayak, N.

2017-06-01

Dried Musa AA group ‘Kluai Leb Mu Nang’ are the famous processing goods of Chumphon province, the south of Thailand. In this paper, we improved the qualities of whole Musa AA group ‘Kluai leb Mu Nang’ by using the hot air and infrared vacuum (HA and infrared vacuum) drying method which has two stages. The first stage of the method is the hot air (HA) and hot air-infrared (HAI) drying for rapidly reducing the moisture content and the drying times at atmospheric pressure, and the second stage, the moisture content, and color of the samples can be controlled by the HA and infrared vacuum drying. The experiment was evaluated by the terms of firmness, color change, moisture content, vacuum pressure and energy consumption at various temperatures. The results were found that the suitable temperature of the HAI and HA and infrared vacuum drying stages at 70°C and 55°C, respectively, while the suitable vacuum pressure in the second process was -0.4 bar. The samples were dried in a total of 28 hrs using 13.83 MJ/kg of specific energy consumption (stage 1 with 8.8 MJ/kg and stage 2 of 5.03 MJ/kg). The physical characteristics of the 21% (wb) of dried bananas can be measured the color change, L*=38.56, a*=16.47 and b*=16.3, was approximate the goods from the local market, whereas the firmness of them was more tender and shown a value of 849.56 kN/m3.

Development of a compact freeze vacuum drying for jelly fish (Schypomedusae)

NASA Astrophysics Data System (ADS)

Alhamid, M. Idrus; Yulianto, M.; Nasruddin

2012-06-01

A new design of a freeze vacuum drying with internal cooling and heater from condenser's heat loss was built and tested. The dryer was used to dry jelly fish (schypomedusae), to study the effect of drying parameters such as the temperature within the drying chamber on mass losses (evaporation) during the freezing stage and the moisture ratio at the end of the drying process. The midili thin layer mathematical drying model was used to estimate and predict the moisture ratio curve based on different drying chamber temperatures. This experiment shows that decreasing the drying chamber temperature with constant pressure results in less mass loss during the freezing stage Drying time was reduced with an increase in drying temperature. Decreasing the drying chamber temperature results in lower pressure saturation of the material has no effect of drying chamber pressure on mass transfer.

Evaluation of Dry, Rough Vacuum Pumps

NASA Technical Reports Server (NTRS)

Hunter, Brian

2006-01-01

This document provides information on the testing and evaluation of thirteen dry rough vacuum pumps of various designs and from various manufacturers. Several types of rough vacuum pumps were evaluated, including scroll, roots, and diaphragm pumps. Tests included long term testing, speed curve generation, voltage variance, vibrations emissions and susceptibility, electromagnetic interference emissions and susceptibility, static leak rate, exhaust restriction, response/recovery time tests, and a contamination analysis for scroll pumps. Parameters were found for operation with helium, which often is not provided from the manufacturer

Drying kinetics and characteristics of combined infrared-vacuum drying of button mushroom slices

NASA Astrophysics Data System (ADS)

Salehi, Fakhreddin; Kashaninejad, Mahdi; Jafarianlari, Ali

2017-05-01

Infrared-vacuum drying characteristics of button mushroom ( Agaricus bisporus) were evaluated in a combined dryer system. The effects of drying parameters, including infrared radiation power (150-375 W), system pressure (5-15 kPa) and time (0-160 min) on the drying kinetics and characteristics of button mushroom slices were investigated. Both the infrared lamp power and vacuum pressure influenced the drying time of button mushroom slices. The rate constants of the nine different kinetic's models for thin layer drying were established by nonlinear regression analysis of the experimental data which were found to be affected mainly by the infrared power level while system pressure had a little effect on the moisture ratios. The regression results showed that the Page model satisfactorily described the drying behavior of button mushroom slices with highest R value and lowest SE values. The effective moisture diffusivity increases as power increases and range between 0.83 and 2.33 × 10-9 m2/s. The rise in infrared power has a negative effect on the ΔE and with increasing in infrared radiation power it was increased.

Vis-NIR hyperspectral imaging in visualizing moisture distribution of mango slices during microwave-vacuum drying.

PubMed

Pu, Yuan-Yuan; Sun, Da-Wen

2015-12-01

Mango slices were dried by microwave-vacuum drying using a domestic microwave oven equipped with a vacuum desiccator inside. Two lab-scale hyperspectral imaging (HSI) systems were employed for moisture prediction. The Page and the Two-term thin-layer drying models were suitable to describe the current drying process with a fitting goodness of R(2)=0.978. Partial least square (PLS) was applied to correlate the mean spectrum of each slice and reference moisture content. With three waveband selection strategies, optimal wavebands corresponding to moisture prediction were identified. The best model RC-PLS-2 (Rp(2)=0.972 and RMSEP=4.611%) was implemented into the moisture visualization procedure. Moisture distribution map clearly showed that the moisture content in the central part of the mango slices was lower than that of other parts. The present study demonstrated that hyperspectral imaging was a useful tool for non-destructively and rapidly measuring and visualizing the moisture content during drying process. Copyright © 2015 Elsevier Ltd. All rights reserved.

New model for colour kinetics of plum under infrared vacuum condition and microwave drying.

PubMed

Chayjan, Reza Amiri; Alaei, Behnam

2016-01-01

Quality of dried foods is affected by the drying method and physiochemical changes in tissue. The drying method affects properties such as colour. The colour of processed food is one of the most important quality indices and plays a determinant role in consumer acceptability of food materials and the processing method. The colour of food materials can be used as an indirect factor to determine changes in quality, since it is simpler and faster than chemical methods. The study focused on the kinetics of colour changes of plum slices, under infrared vacuum and microwave conditions. Drying the samples was implemented at the absolute pressures of 20 and 60 kPa, drying temperatures of 50 and 60°C and microwave power of 90, 270, 450 and 630 W. Colour changes were quantified by the tri-stimulus L* (whiteness/darkness), a* (redness/greenness) and b* (yellowness/blueness) model, which is an international standard for color measurement developed by the Commission Internationale d'Eclairage (CIE). These values were also used to calculate total colour change (∆E), chroma, hue angle, and browning index (BI). A new model was used for mathematical modelling of colour change kinetics. The drying process changed the colour parameters of L*, a*, and b*, causing a colour shift toward the darker region. The values of L* and hue angle decreased, whereas the values of a*, b*, ∆E, chroma and browning index increased during exposure to infrared vacuum conditions and microwave drying. Comparing the results obtained using the new model with two conventional models of zero-order and first-order kinetics indicated that the new model presented more compatibility with the data of colour kinetics for all colour parameters and drying conditions. All kinetic changes in colour parameters can be explained by the new model presented in this study. The hybrid drying system included infrared vacuum conditions and microwave power for initial slow drying of plum slices and provided the desired

Microwave application on air drying of apple (var. Granny Smith). The influence of vacuum impregnation pretreatment

NASA Astrophysics Data System (ADS)

Martin Esparza, Maria Eugenia

Combined hot air-microwave drying has been studied on apple (var. Granny Smith), with and without vacuum impregnation (VI) pretreatment with isotonic solution, respect to kinetics, microstructural and final quality items. In order to reach this objective, a drier has been designed and built, that allows to control and to register all the variables which take place during the drying process. Thermal and dielectric properties, that are very important characteristics when studying heat and mass transfer phenomena that occur during the combined drying process, have been related to temperature and/or moisture content throughout empirical equations. It could be observed that all these properties decreased with product moisture content. Respect to dielectric properties, a relationship among water binding forms to food structure and water molecules relaxation frequency has been found. On the other hand, the effect of drying treatment conditions (air rate, drying temperature, sample thickness and incident microwave power) on the drying rate, from an empirical model based on diffusional mechanisms with two kinetic parameters (k1 and k2), both function of the incident microwave power, has been studied. Microwave application to air drying implied a notable decrease on drying time, the higher the applied power the higher the reduction. Microstructural study by Cryo-Sem revealed fast water vaporization taking place when microwaves are applied. Vacuum impregnation did not implied an additional advantage for combined drying as drying rate was similar to that of NIV samples. Finally, it has been studied the influence of process conditions on the color and mechanical properties of the dried product (IV and NIV). Vacuum impregnation implied an increase on the fracture resistance and less purity and tone angle. Microwave application induced product browning with respect to air drying (tone decreased and purity increased).

Total phenolics content, anthocyanins, and dietary fiber content of apple pomace powders produced by vacuum-belt drying.

PubMed

Yan, Huitong; Kerr, William L

2013-04-01

Apple pomace is a waste material from apple juice processing, and contains significant amounts of dietary fiber and phytochemicals. Many of these compounds may be degraded post-pressing and during drying operations. Continuous vacuum-belt drying (VBD) was studied as a means of drying and maintaining quality of apple pomace. The color and chemical properties of samples dried by vacuum-belt drying at different temperatures were evaluated including total phenolics content (TPC), monomeric anthocyanins (TMA) and dietary fiber content (TDF). VBD powders were pale golden yellow, and those dried at 80°C did not differ in L*, a* and b* values from freeze-dried powders. VBD pomace had 44.9 to 51.9 g gallic acid equivalents kg(-1) TPC, with greatest retention for pomace dried at 80 and 95°C. TPC for pomace dried at 80 or 95°C was not significantly different from that for freeze-dried pomace. TMA levels (74.0 mg C3G kg(-1), where C3G is cyanidine 3-O-glucoside equivalents) were highest in pomace vacuum dried at 80°C. TDF ranged from 442 to 495 g kg(-1) in vacuum-dried pomace and was not significantly different from TDF of freeze-dried poamce (480 g kg(-1)). In all cases, TPC, TMA and TDF were higher in VBD pomace than in freeze-dried whole apple, while VBD pomace prepared at 80 or 95°C had fiber and phytochemical levels similar to freeze-dried powders. © 2012 Society of Chemical Industry.

Non-enzymatic browning and flavour kinetics of vacuum dried onion slices

NASA Astrophysics Data System (ADS)

Mitra, Jayeeta; Shrivastava, Shanker L.; Rao, Pavuluri S.

2015-01-01

Onion slices were dehydrated under vacuum to produce good quality dried ready-to-use onion slices. Colour development due to non-enzymatic browning and flavour loss in terms of thiosulphinate concentration was determined, along with moisture content and rehydration ratio. Kinetics of non-enzymatic browning and thiosulphinate loss during drying was analysed. Colour change due to non-enzymatic browning was found to be much lower in the case of vacuum dried onion, and improved flavour retention was observed as compared to hot air dried onion slices. The optical index values for non-enzymatic browning varied from 18.41 to 38.68 for untreated onion slices and from 16.73 to 36.51 for treated slices, whereas thiosulphinate concentration in the case of untreated onion slices was within the range of 2.96-3.92 μmol g-1 for dried sample and 3.71-4.43 μmol g-1 for the treated onion slices. Rehydration ratio was also increased, which may be attributed to a better porous structure attained due to vacuum drying. The treatment applied was found very suitable in controlling non-enzymatic browning and flavour loss during drying, besides increasing rehydration ratio. Hence, high quality dried ready- to-use onion slices were prepared.

Ultrasonic Spray Drying vs High Vacuum and Microwaves Technology for Blueberries

NASA Astrophysics Data System (ADS)

Candia-Muñoz, N.; Ramirez-Bunster, M.; Vargas-Hernández, Y.; Gaete-Garretón, L.

Interest in high quality foods: good taste and a high content of nutrients with healthy beneficial effects are increasing. Fruits have good properties but, they are lost because the oxidation process, additionally, for different reasons a 40% of harvested fruit are lost. To conserve the fruit properties an ultrasonic assisted spray dryer was developed and tested, comparing its results with microwave-vacuum drying technology. Results did shown taste, color, smell, particle shape and size distribution better than the conventional one. The antioxidants conservation were quite good except in the anthocyanins, in which the microwave and vacuum technology shown best results.

Preparation of High-Grade Powders from Tomato Paste Using a Vacuum Foam Drying Method.

PubMed

Sramek, Martin; Schweiggert, Ralf Martin; van Kampen, Andreas; Carle, Reinhold; Kohlus, Reinhard

2015-08-01

We present a rapid and gentle drying method for the production of high-grade tomato powders from double concentrated tomato paste, comparing results with powders obtained by foam mat air drying and freeze dried powders. The principle of this method consists of drying tomato paste in foamed state at low temperatures in vacuum. The formulations were dried at temperatures of 50, 60, and 70 °C and vacuum of 200 mbar. Foam stability was affected by low serum viscosity and the presence of solid particles in tomato paste. Consequently, serum viscosity was increased by maltodextrin addition, yielding optimum stability at tomato paste:maltodextrin ratio of 2.4:1 (w/w) in dry matter. Material foamability was improved by addition of 0.5% (w/w, fresh weight) egg white. Because of solid particles in tomato paste, foam air filling had to be limited to critical air volume fraction of Φ = 0.7. The paste was first pre-foamed to Φ = 0.2 and subsequently expanded in vacuo. After drying to a moisture content of 5.6% to 7.5% wet base (w.b.), the materials obtained were in glassy state. Qualities of the resulting powders were compared with those produced by freeze and air drying. Total color changes were the least after vacuum drying, whereas air drying resulted in noticeable color changes. Vacuum foam drying at 50 °C led to insignificant carotenoid losses, being equivalent to the time-consuming freeze drying method. In contrast, air drying caused lycopene and β-carotene losses of 18% to 33% and 14% to 19% respectively. Thus, vacuum foam drying enables production of high-grade tomato powders being qualitatively similar to powders obtained by freeze drying. © 2015 Institute of Food Technologists®

Cold Vacuum Drying facility civil structural system design description (SYS 06)

DOE Office of Scientific and Technical Information (OSTI.GOV)

PITKOFF, C.C.

This document describes the Cold Vacuum Drying (CVD) Facility civil - structural system. This system consists of the facility structure, including the administrative and process areas. The system's primary purpose is to provide for a facility to house the CVD process and personnel and to provide a tertiary level of containment. The document provides a description of the facility and demonstrates how the design meets the various requirements imposed by the safety analysis report and the design requirements document.

SLUDGE TREATMENT PROJECT KOP DISPOSITION - THERMAL AND GAS ANALYSIS FOR THE COLD VACUUM DRYING FACILITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

SWENSON JA; CROWE RD; APTHORPE R

2010-03-09

The purpose of this document is to present conceptual design phase thermal process calculations that support the process design and process safety basis for the cold vacuum drying of K Basin KOP material. This document is intended to demonstrate that the conceptual approach: (1) Represents a workable process design that is suitable for development in preliminary design; and (2) Will support formal safety documentation to be prepared during the definitive design phase to establish an acceptable safety basis. The Sludge Treatment Project (STP) is responsible for the disposition of Knock Out Pot (KOP) sludge within the 105-K West (KW) Basin.more » KOP sludge consists of size segregated material (primarily canister particulate) from the fuel and scrap cleaning process used in the Spent Nuclear Fuel process at K Basin. The KOP sludge will be pre-treated to remove fines and some of the constituents containing chemically bound water, after which it is referred to as KOP material. The KOP material will then be loaded into a Multi-Canister Overpack (MCO), dried at the Cold Vacuum Drying Facility (CVDF) and stored in the Canister Storage Building (CSB). This process is patterned after the successful drying of 2100 metric tons of spent fuel, and uses the same facilities and much of the same equipment that was used for drying fuel and scrap. Table ES-l present similarities and differences between KOP material and fuel and between MCOs loaded with these materials. The potential content of bound water bearing constituents limits the mass ofKOP material in an MCO load to a fraction of that in an MCO containing fuel and scrap; however, the small particle size of the KOP material causes the surface area to be significantly higher. This relatively large reactive surface area represents an input to the KOP thermal calculations that is significantly different from the calculations for fuel MCOs. The conceptual design provides for a copper insert block that limits the volume

Insulation Technology in Dry Air and Vacuum for a 72kV Low Pressured Dry Air Insulated Switchgear

NASA Astrophysics Data System (ADS)

Yoshida, Tadahiro; Koga, Hiromi; Harada, Takakazu; Miki, Shinichi; Arioka, Masahiro; Sato, Shinji; Yoshida, Satoru; Inoue, Naoaki; Maruyama, Akihiko; Takeuchi, Toshie

A new 72kV rated low pressured dry air insulated switchgear applying electromagnetic actuation and function that supports CBM has been developed. First, dielectric characteristics in dry air under lightning impulse application has been investigated at bare and insulator covered electrodes. Dependence of the breakdown electric field strength on the effective area has been clarified to apply the configuration design of the insulation mold for the vacuum interrupter. In addition, moisture volume dependence on surface resistance has been clarified to decide moisture volume in gas pressure tank. Next, a new vacuum circuit breaker (VCB) has been designed. To keep dimensions from former 72kV SF6 gas insulated switchgear, distance between contacts in vacuum interrupter is needed to be shorter than that of former switchgear. Voltage withstand capability between electrodes practically designed for vacuum interrupter has been investigated under dc voltage application simulated the small capacitive current breaking test. Gap configuration including contacts and slits has been optimized and distance has been shortened 11% from former switchgear. As a result, the new low pressured dry air insulated switchgear has been designed comparably in outer size to former SF6 gas insulated switchgear. Using dry air as an insulation medium with low pressure has been able to reduce the environmental burden.

Method for calculating the duration of vacuum drying of a metal-concrete container for spent nuclear fuel

NASA Astrophysics Data System (ADS)

Karyakin, Yu. E.; Nekhozhin, M. A.; Pletnev, A. A.

2013-07-01

A method for calculating the quantity of moisture in a metal-concrete container in the process of its charging with spent nuclear fuel is proposed. A computing method and results obtained by it for conservative estimation of the time of vacuum drying of a container charged with spent nuclear fuel by technologies with quantization and without quantization of the lower fuel element cluster are presented. It has been shown that the absence of quantization in loading spent fuel increases several times the time of vacuum drying of the metal-concrete container.

Effect of Microwave Vacuum Drying on the Drying Characteristics, Color, Microstructure, and Antioxidant Activity of Green Coffee Beans.

PubMed

Dong, Wenjiang; Cheng, Ke; Hu, Rongsuo; Chu, Zhong; Zhao, Jianping; Long, Yuzhou

2018-05-11

The aim of this study is to investigate the effect of microwave vacuum drying (MVD) on the drying characteristics and quality attributes of green coffee beans. We specifically focused on the effective moisture diffusion coefficient ( D eff ), surface temperature, glass transition temperature ( T g ), water state, and microstructure. The kinetics of color changes during drying, total phenolic content (TPC), and antioxidant activity (DPPH, FRAP, and ABTS) were also characterized. Microwave power during MVD affected the porosity of coffee beans, their color, TPC, and antioxidant activity. The Allometric 1 model was the most suitable for simulating surface temperature rise kinetics. Thermal processing of green coffee beans resulted in increased b* , L* , Δ E , and TPC values, and greater antioxidant capacity. These findings may provide a theoretical reference for the technical improvement, mechanisms of flavor compound formation, and quality control of dried green coffee beans.

Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives.

PubMed

Purtov, Julia; Frensemeier, Mareike; Kroner, Elmar

2015-11-04

Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects.

Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives

PubMed Central

2015-01-01

Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm2 provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects. PMID:26457864

Cold Vacuum Drying (CVD) Facility Acceptance for Beneficial Use

DOE Office of Scientific and Technical Information (OSTI.GOV)

BRISBIN, S.A.

2000-01-05

This document provides a checklist of the items required for turnover of the Cold Vacuum Drying Facility from the Construction Projects organization to the Operations organization. This document will be updated periodically to document completion of additional deliverables.

Changes in non-volatile taste components of button mushroom (Agaricus bisporus) during different stages of freeze drying and freeze drying combined with microwave vacuum drying.

PubMed

Pei, Fei; Shi, Ying; Gao, Xingyang; Wu, Fangning; Mariga, Alfred Mugambi; Yang, Wenjian; Zhao, Liyan; An, Xinxin; Xin, Zhihong; Yang, Fangmei; Hu, Qiuhui

2014-12-15

Button mushroom slices were dehydrated using freeze drying (FD) or FD combined with microwave vacuum drying (FMVD), and the non-volatile component profiles were studied. The results showed that the level of non-volatile components in button mushroom firstly increased during sublimation of FD/FMVD process and then fell during desorption in FD process and MVD in FMVD process. Compared to FD products, the contents of soluble sugars and polyols in FMVD products were relatively low, whereas the contents of total free amino acids were significantly higher, close to the level of fresh mushroom. However, there was no significant difference in the contents of 5'-nucleotides and organic acids between FD and FMVD products. The equivalent umami concentration (EUC) values for FD and FMVD products did not differ from fresh, indicating that both drying methods could effectively preserve MSG (monosodium glutamate)-like components in button mushroom. Copyright © 2014 Elsevier Ltd. All rights reserved.

Short communication: Effects of vacuum freeze-drying on inactivation of Cronobacter sakazakii ATCC29544 in liquid media with different initial inoculum levels.

PubMed

Jiao, Rui; Gao, Jina; Zhang, Xiyan; Zhang, Maofeng; Chen, Jiren; Wu, Qingping; Zhang, Jumei; Ye, Yingwang

2017-03-01

Vacuum freeze-drying is an important food-processing technology for valid retention of nutrients and bioactive compounds. Cronobacter sakazakii has been reported to be associated with severe infections in neonates through consumption of contaminated powdered infant formula. In this study, effects of vacuum freeze-drying treatment for 12, 24, and 36 h on inactivation of C. sakazakii with different initial inoculum levels in sterile water, tryptic soy broth (TSB), skim milk, and whole milk were determined. Results indicated that the lethality rate of C. sakazakii in each sample increased with the extension of vacuum freeze-drying time. With initial inoculum levels of 10 2 and 10 3 cfu/mL, the survival of C. sakazakii in different liquid media was significantly affected by vacuum freeze-drying for 12, 24, and 36 h. In addition, the lethality rates of C. sakazakii in whole milk, skim milk, and TSB was significantly reduced compared with those in sterile water. Furthermore, whole milk showed the strongest protective role for C. sakazakii cells, followed by skim milk and TSB medium. Using the scanning electron microscope, the intracellular damage and obvious distortion of C. sakazakii cells were observed after vacuum freeze-drying for 24 and 36 h compared with the untreated sample, and the injured cells increased with the extension of vacuum-drying time. We concluded that inactivation of vacuum freeze-drying on C. sakazakii cells is related to the food matrix, and a combination with other methods for inactivating C. sakazakii is required for ensuring microbial safety of powdered infant formula. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Graphene oxide for acid catalyzed-reactions: Effect of drying process

NASA Astrophysics Data System (ADS)

Gong, H. P.; Hua, W. M.; Yue, Y. H.; Gao, Z.

2017-03-01

Graphene oxides (GOs) were prepared by Hummers method through various drying processes, and characterized by XRD, SEM, FTIR, XPS and N2 adsorption. Their acidities were measured using potentiometric titration and acid-base titration. The catalytic properties were investigated in the alkylation of anisole with benzyl alcohol and transesterification of triacetin with methanol. GOs are active catalysts for both reaction, whose activity is greatly affected by their drying processes. Vacuum drying GO exhibits the best performance in transesterification while freezing drying GO is most active for alkylation. The excellent catalytic behavior comes from abundant surface acid sites as well as proper surface functional groups, which can be obtained by selecting appropriate drying process.

Vacuum Drying for Extending Litchi Shelf-Life: Vitamin C, Total Phenolics, Texture and Shelf-Life Assessment.

PubMed

Richter Reis, Felipe; de Oliveira, Aline Caroline; Gadelha, Gabriella Giani Pieretti; de Abreu, Marcela Breves; Soares, Hillary Isabelle

2017-06-01

In an attempt to obtain shelf-stable litchi fruit with preserved nutritional quality and good sensory features, quarters of peeled and pitted fruits were vacuum dried at 50, 60 and 70 °C at a constant pressure of 8.0 kPa. The product was assessed for its vitamin C, total phenolics and texture (hardness). In addition, the product with the best texture was assessed for its shelf-life by means of accelerated testing. Results suggest that vacuum dried litchi retained almost 70% of the vitamin C and total phenolics when compared to frozen fruits (control). Vitamin C and phenolic compounds content significantly decreased with drying, while no difference was found between different drying temperatures. Hardness increased with drying temperature. The sample dried at 70 °C presented crispness, which is a desired quality feature in dried fruit products. This sample was subjected to shelf-life evaluation, whose result suggests a shelf-life of eight months at 23 °C. Total color change (CIE ΔE 00 ) was the expiry criterion. Vacuum drying was a suitable technique for producing shelf-stable litchi fruit with good texture while preserving its desirable original nutrients. Consumption of vacuum dried litchi may be beneficial to health due to its remarkable content of phenolic compounds and vitamin C.

Influence of vacuum drying temperature on: physico-chemical composition and antioxidant properties of murta berries

USDA-ARS?s Scientific Manuscript database

Murta (Ugni molinae T.) berries were vacuum dried at a constant pressure of 15 kPa. The effects of processing temperatures (50, 60, 70, 80 and 90 °C) on the physico-chemical characteristics, the phenolic and flavonoid compounds, the antioxidant activity (measured by DPPH and ORAC) and the sugar and ...

A New Freezing Method Using Pre-Dehydration by Microwave-Vacuum Drying

NASA Astrophysics Data System (ADS)

Tsuruta, Takaharu; Hamidi, Nurkholis

Partial dehydration by microwave-vacuum drying has been applied to tuna and strawberry in order to reduce cell-damages caused by the formation of large ice-crystals during freezing. The samples were subjected to microwave vacuum drying at pressure of 5 kPa and temperature less than 27°C to remove small amount of water prior to freezing. The tuna were cooled by using the freezing chamber at temperature -50°C or -150°C, while the strawberries were frozen at temperature -30°C or -80°C, respectively. The temperature transients in tuna showed that removing some water before freezing made the freezing time shorter. The observations of ice crystal clearly indicated that rapid cooling and pre-dehydration prior to freezing were effective in minimizing the size of ice crystal. It is also understood that the formation of large ice crystals has a close relation to the cell damages. After thawing, the observation of microstructure was done on the tuna and strawberry halves. The pre-dehydrated samples showed a better structure than the un-dehydrated one. It is concluded that the pre-dehydration by microwave-vacuum drying is one promising method for the cryo-preservation of foods.

Stabilities of Dried Suspensions of Influenza Virus Sealed in a Vacuum or Under Different Gases

PubMed Central

Greiff, Donald; Rightsel, Wilton A.

1969-01-01

Suspensions of purified influenza virus, dried to a 1.4% content of residual moisture by sublimation of ice in vacuo, were sealed in a vacuum or under different gases of high purity. The stabilities of the several preparations were determined by an accelerated storage test. Based on the times predicted for the dried preparations stored at different temperatures to lose 1 log of infectivity titer, the order of stabilities in relation to sealing in vacuum or under different gases was as follows: helium > hydrogen > vacuum > argon > nitrogen > oxygen > carbon dioxide. Images PMID:5797938

Lipid and protein oxidation and sensory properties of vacuum-packaged dry-cured ham subjected to high hydrostatic pressure.

PubMed

Fuentes, Verónica; Ventanas, Jesús; Morcuende, David; Estévez, Mario; Ventanas, Sonia

2010-07-01

The effect of HHP treatment (600 MPa) on the oxidative stability of lipids and proteins of vacuum-packaged Iberian dry-cured ham and the impact on the sensory characteristics of the product was investigated. In order to assess how different commercial presentations are affected by HHP treatment, three different presentations of vacuum-packaged Iberian dry-cured ham were considered, namely, (i) intact format (IF) corresponding to non-sliced vacuum-packaged dry-cured ham, (ii) conventional-sliced format (CSF) corresponding to dry-cured ham slices placed stretched out in the package and (iii) alternative-sliced format (ASF) corresponding to dry-cured ham slices piled up horizontally. The oxidation of dry-cured ham lipids and proteins was enhanced by HHP-treatment with the presentation being highly influential on these oxidative reactions. Pre-slicing dry-cured ham results in a more susceptible product to oxidative reactions during pressurisation and subsequent refrigerated storage. Possible mechanisms, by which HHP-induced oxidative reactions would affect particular sensory traits in vacuum-packaged Iberian dry-cured ham such as colour, texture and flavour attributes, are discussed. Copyright 2010 Elsevier Ltd. All rights reserved.

Overview of High Power Vacuum Dry RF Load Designs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krasnykh, Anatoly

2015-08-27

A specific feature of RF linacs based on the pulsed traveling wave (TW) mode of operation is that only a portion of the RF energy is used for the beam acceleration. The residual RF energy has to be terminated into an RF load. Higher accelerating gradients require higher RF sources and RF loads, which can stably terminate the residual RF power. RF feeders (from the RF source though the accelerating section to the load) are vacuumed to transmit multi-megawatt high power RF. This overview will outline vacuumed RF loads only. A common method to terminate multi-MW RF power is tomore » use circulated water (or other liquid) as an absorbing medium. A solid dielectric interface (a high quality ceramic) is required to separate vacuum and liquid RF absorber mediums. Using such RF load approaches in TW linacs is troubling because there is a fragile ceramic window barrier and a failure could become catastrophic for linac vacuum and RF systems. Traditional loads comprising of a ceramic disk have limited peak and average power handling capability and are therefore not suitable for high gradient TW linacs. This overview will focus on ''vacuum dry'' or ''all-metal'' loads that do not employ any dielectric interface between vacuum and absorber. The first prototype is an original design of RF loads for the Stanford Two-Mile Accelerator.« less

Meat quality, microbiological status and consumer preference of beef gluteus medius aged in a dry ageing bag or vacuum.

PubMed

Li, Xin; Babol, Jakub; Wallby, Anna; Lundström, Kerstin

2013-10-01

This study investigated meat quality and consumer preference after ageing beef gluteus medius in a water vapour-permeable dry-ageing bag or in vacuum for 14 days. Higher ageing and trim losses but lower thawing loss, cooking loss and water content were found in samples aged in dry ageing bags compared to those aged in vacuum. Samples aged in dry ageing bags had higher total bacteria and yeast counts but lower lactic acid bacteria counts than those aged in vacuum, both before and after trimming. Meat aged in dry ageing bag was more tender and juicier and overall preferred by consumers compared with samples aged in vacuum. Female participants outperformed the males in detecting differences in palatability. No differences were found in pH, smell, shear force, colour, Enterobacteriaceae, and mould counts. Thus, by using a dry ageing bag, it is possible to produce dry-aged meat in a more controlled condition without negative effects on sensory or other quality attributes. Copyright © 2013. Published by Elsevier Ltd.

Characterisation of Aronia powders obtained by different drying processes.

PubMed

Horszwald, Anna; Julien, Heritier; Andlauer, Wilfried

2013-12-01

Nowadays, food industry is facing challenges connected with the preservation of the highest possible quality of fruit products obtained after processing. Attention has been drawn to Aronia fruits due to numerous health promoting properties of their products. However, processing of Aronia, like other berries, leads to difficulties that stem from the preparation process, as well as changes in the composition of bioactive compounds. Consequently, in this study, Aronia commercial juice was subjected to different drying techniques: spray drying, freeze drying and vacuum drying with the temperature range of 40-80 °C. All powders obtained had a high content of total polyphenols. Powders gained by spray drying had the highest values which corresponded to a high content of total flavonoids, total monomeric anthocyanins, cyaniding-3-glucoside and total proanthocyanidins. Analysis of the results exhibited a correlation between selected bioactive compounds and their antioxidant capacity. In conclusion, drying techniques have an impact on selected quality parameters, and different drying techniques cause changes in the content of bioactives analysed. Spray drying can be recommended for preservation of bioactives in Aronia products. Powder quality depends mainly on the process applied and parameters chosen. Therefore, Aronia powders production should be adapted to the requirements and design of the final product. Copyright © 2013 Elsevier Ltd. All rights reserved.

Drying based on temperature-detection-assisted control in microwave-assisted pulse-spouted vacuum drying.

PubMed

Cao, Xiaohuang; Zhang, Min; Qian, He; Mujumdar, Arun S

2017-06-01

An online temperature-detection-assisted control system of microwave-assisted pulse-spouted vacuum drying was newly developed. By using this system, temperature control can be automatically and continuously adjusted based on the detection of drying temperature and preset temperature. Various strategies for constant temperature control, linear temperature control and three-step temperature control were applied to drying carrot cubes. Drying kinetics and the quality of various temperature-controlled strategies online are evaluated for the new drying technology as well as its suitability as an alternative drying method. Drying time in 70 °C mode 1 had the shortest drying time and lowest energy consumption in all modes. A suitable colour, highest re-hydration ratio and fracture-hardness, and longest drying time occurred in 30-40-50 °C mode 3. The number of hot spots was reduced in 40-50-60 °C mode 3. Acceptable carrot snacks were obtained in 50-60-70 °C mode 3 and 70 °C mode 2. All temperature curves showed that the actual temperatures followed the preset temperatures appropriately. With this system, a linear temperature-controlled strategy and a three-step temperature-controlled strategy can improve product quality and heating non-uniformity compared to constant temperature control, but need greater energy consumption and longer drying time. A temperature-detection-assisted control system was developed for providing various drying strategies as a suitable alternative in making a snack product. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Consumer preference and effect of correct or misleading information after ageing beef longissimus muscle using vacuum, dry ageing, or a dry ageing bag.

PubMed

Stenström, Helena; Li, Xin; Hunt, Melvin C; Lundström, Kerstin

2014-02-01

The objective of this study was to determine which ageing treatment of beef was sensorially preferred by consumers and how their preference changed when given information about the ageing treatment used. Longissimus thoracis et lumborum from four young bulls were randomly assigned three ageing treatments: dry ageing, vacuum ageing and ageing in a highly moisture permeable bag (bag dry-ageing); each was aged at 1.6 °C for another 13 days. A preference test (171 consumers) with questions about overall liking, tenderness, and juiciness was performed. Thereafter, a deceptive test (61 consumers) was performed with two taste samples, the first taste sample with correct information about ageing treatment and the second with false information. In the preference test, consumers preferred dry ageing and bag dry-ageing to vacuum ageing. In the deceptive test, dry ageing was preferred, but the information given influenced preference. © 2013.

Simple and Rapid Immobilization of Coating Polymers on Poly(dimethyl siloxane)-glass Hybrid Microchips by a Vacuum-drying Method.

PubMed

Kitagawa, Fumihiko; Nakagawara, Syo; Nukatsuka, Isoshi; Hori, Yusuke; Sueyoshi, Kenji; Otsuka, Koji

2015-01-01

A simple and rapid vacuum-drying modification method was applied to several neutral and charged polymers to obtain coating layers for controlling electroosmotic flow (EOF) and suppressing sample adsorption on poly(dimethyl siloxane) (PDMS)-glass hybrid microchips. In the vacuum-dried poly(vinylpyrrolidone) coating, the electroosmotic mobility (μeo) was suppressed from +2.1 to +0.88 × 10(-4) cm(2)/V·s, and the relative standard deviation (RSD) of μeo was improved from 10.2 to 2.5% relative to the bare microchannel. Among several neutral polymers, poly(vinylalcohol) (PVA) and poly(dimethylacrylamide) coatings gave more suppressed and repeatable EOF with RSDs of less than 2.3%. The vacuum-drying method was also applicable to polyanions and polycations to provide accelerated and inversed EOF, respectively, with acceptable RSDs of less than 4.9%. In the microchip electrophoresis (MCE) analysis of bovine serum albumin (BSA) in the vacuum-dried and thermally-treated PVA coating channel, an almost symmetric peak of BSA was obtained, while in the native microchannel a significantly skewed peak was observed. The results demonstrated that the vacuum-dried polymer coatings were effective to control the EOF, and reduced the surface adsorption of proteins in MCE.

Relevance of nanocomposite packaging on the stability of vacuum-packed dry cured ham.

PubMed

Lloret, Elsa; Fernandez, Avelina; Trbojevich, Raul; Arnau, Jacint; Picouet, Pierre A

2016-08-01

In this study effects of a novel high barrier multilayer polyamide film containing dispersed nanoclays (PAN) on the stability of vacuum packed dry-cured ham were investigated during 90days refrigerated storage in comparison with non-modified multilayer polyamide (PA) and a commercial high barrier film. Characteristic bands of the mineral in FT-IR spectra confirmed the presence of nanoclays in PAN, enhancing oxygen transmission barrier properties and UV protection. Packaging in PAN films did not originate significant changes on colour or lipid oxidation during prolonged storage of vacuum-packed dry-cured ham. Larger oxygen transmission rates in PA films caused changes in CIE b* during refrigerated storage. Ham quality was not affected by light exposition during 90days and only curing had a significant benefit on colour and TBARS, being cured samples more stable during storage in all the packages used. Packaging of dry-cured ham in PAN was equivalent to commercial high barrier films. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Freeze drying process optimization of ginger juice-adjuvant for Chinese materia medica processing and stability of freeze-dried ginger juice powder].

PubMed

Yang, Chun-Yu; Guo, Feng-Qian; Zang, Chen; Cao, Hui; Zhang, Bao-Xian

2018-02-01

Ginger juice， a commonly used adjuvant for Chinese materia medica， is applied in processing of multiple Chinese herbal decoction pieces. Because of the raw materials and preparation process of ginger juice， it is difficult to be preserved for a long time， and the dosage of ginger juice in the processing can not be determined base on its content of main compositions. Ginger juice from different sources is hard to achieve consistent effect during the processing of traditional Chinese herbal decoction pieces. Based on the previous studies， the freeze drying of ginger juice under different shelf temperatures and vacuum degrees were studied， and the optimized freeze drying condition of ginger juice was determined. The content determination method for 6-gingerol， 8-gingerol， 10-gingerol and 6-shagaol in ginger juice and redissolved ginger juice was established. The content changes of 6-gingerol， 8-gingerol， 10-gingerol， 6-gingerol， 6-shagaol， volatile oil and total phenol were studied through the drying process and 30 days preservation period. The results showed that the freeze drying time of ginger juice was shortened after process optimization; the compositions basically remained unchanged after freeze drying， and there was no significant changes in the total phenol content and gingerol content， but the volatile oil content was significantly decreased( P <0.05). Within 30 days， the contents of gingerol， total phenol， and volatile oil were on the decline as a whole. This study has preliminarily proved the feasibility of freeze-drying process of ginger juice as an adjuvant for Chinese medicine processing. Copyright© by the Chinese Pharmaceutical Association.

Formulation design and optimization of mouth dissolve tablets of nimesulide using vacuum drying technique.

PubMed

Gohel, Mukesh; Patel, Madhabhai; Amin, Avani; Agrawal, Ruchi; Dave, Rikita; Bariya, Nehal

2004-04-26

The purpose of this research was to develop mouth dissolve tablets of nimesulide. Granules containing nimesulide, camphor, crospovidone, and lactose were prepared by wet granulation technique. Camphor was sublimed from the dried granules by exposure to vacuum. The porous granules were then compressed. Alternatively, tablets were first prepared and later exposed to vacuum. The tablets were evaluated for percentage friability, wetting time, and disintegration time. In the investigation, a 32 full factorial design was used to investigate the joint influence of 2 formulation variables: amount of camphor and crospovidone. The results of multiple linear regression analysis revealed that for obtaining a rapidly disintegrating dosage form, tablets should be prepared using an optimum concentration of camphor and a higher percentage of crospovidone. A contour plot is also presented to graphically represent the effect of the independent variables on the disintegration time and percentage friability. A checkpoint batch was also prepared to prove the validity of the evolved mathematical model. Sublimation of camphor from tablets resulted in superior tablets as compared with the tablets prepared from granules that were exposed to vacuum. The systematic formulation approach helped in understanding the effect of formulation processing variables.

Vacuum mechatronics

NASA Technical Reports Server (NTRS)

Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

1989-01-01

The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

Cold Vacuum Drying (CVD) Set Point Determination

DOE Office of Scientific and Technical Information (OSTI.GOV)

PHILIPP, B.L.

2000-03-21

The Safety Class Instrumentation and Control (SCIC) system provides active detection and response to process anomalies that, if unmitigated, would result in a safety event. Specifically, actuation of the SCIC system includes two portions. The portion which isolates the MCO and initiates the safety-class helium (SCHe) purge, and the portion which detects and stops excessive heat input to the MCO on high tempered water MCO inlet temperature. For the MCO isolation and purge, the SCIC receives signals from MCO pressure (both positive pressure and vacuum), helium flow rate, bay high temperature switches, seismic trips and time under vacuum trips.

New Processes for Freeze-Drying in Dual-Chamber Systems.

PubMed

Werk, T; Ludwig, I S; Luemkemann, J; Huwyler, J; Mahler, H-C; Haeuser, C R; Hafner, M

2016-01-01

Dual-chamber systems can offer self-administration and home care use for lyophilized biologics. Only a few products have been launched in dual-chamber systems so far-presumably due to dual-chamber systems' complex and costly drug product manufacturing process. Within this paper, two improved processes (both based on tray filling technology) for freeze-drying pharmaceuticals in dual-chamber systems are described. Challenges with regards to heat transfer were tackled by (1) performing the freeze-drying step in a needle-down orientation in combination with an aluminum block, or (2) freeze-drying the drug product "externally" in a metal cartridge with subsequent filling of the lyophilized cake into the dual-chamber system. Metal-mediated heat transfer was shown to be efficient in both cases and batch (unit-to-unit) homogeneity with regards to sublimation rate was increased. It was difficult to influence ice crystal size using different methods when in use with an aluminum block due to its heat capacity. Using such a metal carrier implies a large heat capacity leading to relatively small ice crystals. Compared to the established process, drying times were reduced by half using the new processes. The drying time was, however, longer for syringes compared to vials due to the syringe design (long and slim). The differences in drying times were less pronounced for aggressive drying cycles. The proposed processes may help to considerably decrease investment costs into dual-chamber system fill-finish equipment. Dual-chamber syringes offer self-administration and home care use for freeze-dried pharmaceuticals. Only a few products have been launched in dual-chamber syringes so far-presumably due to their complex and costly drug product manufacturing process. In this paper two improved processes for freeze-drying pharmaceuticals in dual-chamber syringes are described. The major challenge of freeze-drying is to transfer heat through a vacuum. The proposed processes cope with this

Robust Vacuum-/Air-Dried Graphene Aerogels and Fast Recoverable Shape-Memory Hybrid Foams.

PubMed

Li, Chenwei; Qiu, Ling; Zhang, Baoqing; Li, Dan; Liu, Chen-Yang

2016-02-17

New graphene aerogels can be fabricated by vacuum/air drying, and because of the mechanical robustness of the graphene aerogels, shape-memory polymer/graphene hybrid foams can be fabricated by a simple infiltration-air-drying-crosslinking method. Due to the superelasticity, high strength, and good electrical conductivity of the as-prepared graphene aerogels, the shape-memory hybrid foams exhibit excellent thermotropical and electrical shape-memory properties, outperforming previously reported shape-memory polymer foams. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Drying performance of fermented cassava (fercaf) using a convective multiple flash dryer

NASA Astrophysics Data System (ADS)

Handojo, Lienda A.; Zefanya, Samuel; Christanto, Yohanes

2017-05-01

Fermented cassava (fercaf) is a tropical versatile carbohydrate source flour which is produced by modifying the characteristics of cassava. Drying process is one of the processes that could influence the quality of fercaf. In general, for food application, convective and vacuum drying were used, however recently another advanced method using combination of both convective and vacuum, i.e. convective multiple flash drying (CMFD), was proposed. This method is conducted by repeating cycles of convective and vacuum drying in intermittent manner. Cassava chips with thickness of 0.1-0.2 cm were fermented for 24 hours at room condition. Then, the drying process was conducted by using 3 techniques, i.e. convective, vacuum, and combined method (CMFD), with operation temperatures between 50 and 70°C for 10 hours or until fermented cassava reached a moisture content of less than 20%. The study shows that CMFD was the fastest drying method with only 5-6 hours period compared to 8-10 hours using vacuum and more than 10 hours using convective method. CMFD also produces harder fercaf chips than those of vacuum and convective methods. Moreover, this research also proves that the operating pressure and temperature influence the moisture content.

Effect of vacuum and of strong adsorbed water films on micropore formation in aluminum hydroxide xerogel powders.

PubMed

Beruto, Dario T; Botter, Rodolfo; Converti, Attilio

2009-02-01

Aluminum hydroxide gels were washed with water, ethanol, methanol and isopropanol to obtain new gels with different liquid phases that were dried either in air at 120 degrees C or under vacuum at 80 degrees C. Drying in air leads to alcoholic xerogels with BET surface areas larger than the aqueous ones. The effect of the alcoholic groups as substitutes of the hydroxyl ones has been discussed to account for the final size of xerogel crystallites. Drying under vacuum decreases the BET surface of the methanol xerogels, but no micropores are formed in all the alcoholic xerogel matrixes. On the contrary, the vacuum drying process changes significantly the microstructure of the aqueous xerogels. Their BET surface increases by 34 m(2)/g, and micropores are formed within their crystallite aggregates. It has been experimentally shown that these changes are due to a shear transformation that occurs in the boehmite xerogels obtained under vacuum. To discuss these data, the existence of chemical compounds such as AlOOHnH(2)O was postulated. On this ground, a neat analogy between vacuum drying process and vacuum interfacial decomposition reactions of inorganic salts can be drawn. This analogy explains how a state of stresses forms in aqueous xerogel matrix during vacuum drying process.

Critically safe volume vacuum pickup for use in wet or dry cleanup of radioactive enclosures

DOEpatents

Zeren, J.D.

1993-12-28

A physical compact vacuum pickup device of critically safe volume and geometric shape is provided for use in radioactive enclosures, such as a small glove box, to facilitate manual cleanup of either wet or dry radioactive material. The device is constructed and arranged so as to remain safe when filled to capacity with plutonium-239 oxide. Two fine mesh filter bags are supported on the exterior of a rigid fine mesh stainless steel cup. This assembly is sealed within, and spaced from, the interior walls of a stainless steel canister. An air inlet communicates with the interior of the canister. A modified conventional vacuum head is physically connected to, and associated with, the interior of the mesh cup. The volume of the canister, as defined by the space between the mesh cup and the interior walls of the canister, forms a critically safe volume and geometric shape for dry radioactive particles that are gathered within the canister. A critically safe liquid volume is maintained by operation of a suction terminating float valve, and/or by operation of redundant vacuum check/liquid drain valves and placement of the air inlet. 5 figures.

Critically safe volume vacuum pickup for use in wet or dry cleanup of radioactive enclosures

DOEpatents

Zeren, Joseph D.

1993-12-28

A physical compact vacuum pickup device of critically safe volume and geometric shape is provided for use in radioactive enclosures, such as a small glove box, to facilitate manual cleanup of either wet or dry radioactive material. The device is constructed and arranged so as to remain safe when filled to capacity with plutonium-239 oxide. Two fine mesh filter bags are supported on the exterior of a rigid fine mesh stainless steel cup. This assembly is sealed within, and spaced from, the interior walls of a stainless steel canister. An air inlet communicates with the interior of the canister. A modified conventional vacuum head is physically connected to, and associated with, the interior of the mesh cup. The volume of the canister, as defined by the space between the mesh cup and the interior walls of the canister, forms a critically safe volume and geometric shape for dry radioactive particles that are gathered within the canister. A critically safe liquid volume is maintained by operation of a suction terminating float valve, and/or by operation of redundant vacuum check/liquid drain valves and placement of the air inlet.

Effects of four different drying methods on the carotenoid composition and antioxidant capacity of dried Gac peel.

PubMed

Chuyen, Hoang V; Roach, Paul D; Golding, John B; Parks, Sophie E; Nguyen, Minh H

2017-03-01

Gac fruit (Momordica cochinchinensis Spreng.) is a rich source of carotenoids for the manufacture of powder, oil and capsules for food, cosmetic and pharmaceutical uses. Currently, only the aril of the Gac fruit is processed and the peel, similar to the other components, is discarded, although it contains high level of carotenoids, which could be extracted for commercial use. In the present study, four different drying methods (hot-air, vacuum, heat pump and freeze drying), different temperatures and drying times were investigated for producing dried Gac peel suitable for carotenoid extraction. The drying methods and drying temperatures significantly affected the drying time, carotenoid content and antioxidant capacity of the dried Gac peel. Among the investigated drying methods, hot-air drying at 80  o C and vacuum drying at 50  o C produced dried Gac peel that exhibited the highest retention of carotenoids and the strongest antioxidant capacity. Hot-air drying at 80  o C and vacuum drying at 50  o C are recommended for the drying of Gac peel. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Multipurpose Vacuum Induction Processing System

NASA Astrophysics Data System (ADS)

Govindaraju, M.; Kulkarni, Deepak; Balasubramanian, K.

2012-11-01

Multipurpose vacuum processing systems are cost effective; occupy less space, multiple functional under one roof and user friendly. A multipurpose vacuum induction system was designed, fabricated and installed in a record time of 6 months time at NFTDC Hyderabad. It was designed to function as a) vacuum induction melting/refining of oxygen free electronic copper/pure metals, b) vacuum induction melting furnace for ferrous materials c) vacuum induction melting for non ferrous materials d) large vacuum heat treatment chamber by resistance heating (by detachable coil and hot zone) e) bottom discharge vacuum induction melting system for non ferrous materials f) Induction heat treatment system and g) directional solidification /investment casting. It contains provision for future capacity addition. The attachments require to manufacture multiple shaped castings and continuous rod casting can be added whenever need arises. Present capacity is decided on the requirement for 10years of development path; presently it has 1.2 ton liquid copper handling capacity. It is equipped with provision for capacity addition up to 2 ton liquid copper handling capacity in future. Provision is made to carry out the capacity addition in easy steps quickly. For easy operational maintenance and troubleshooting, design was made in easily detachable sections. High vacuum system is also is detachable, independent and easily movable which is first of its kind in the country. Detailed design parameters, advantages and development history are presented in this paper.

Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets

PubMed Central

Yu, Chang Ho; Yiin, Lih-Ming; Fan, Zhi-Hua (Tina); Rhoads, George G.

2014-01-01

Dry steam cleaning, which has gained recent attention as an effective method to reduce house dust mite (HDM) allergen concentration and loading in carpets, was evaluated in this study for its efficacy in lowering levels of polycyclic aromatic hydrocarbons (PAHs) as well as HDM allergens. Fifty urban homes with wail-to-wall carpets, mostly low-income and with known lead contamination, were studied in 2003 and 2004. Two carpet-cleaning interventions were compared: Repeated HEPA (High Efficiency Particulate Air filtered) vacuuming alone and repeated HEPA vacuuming supplemented with dry steam cleaning. Vacuum samples were collected to measure carpet loading of dust and contaminants immediately before and after cleaning. Paired comparisons were conducted to evaluate the effectiveness of the cleaning protocols in reducing the levels of PAHs and HDM allergens in carpets. The results indicated that both cleaning methods substantially reduced the loading of PAHs and HDM allergens as well as dust in carpets (p < 0.0001). The reductions in loading of dust (64.4%), PAHs (69.1%), and HDM allergens (85.5%), by dry steam cleaning plus repetitive HEPA vacuuming were larger than the reductions by regular HEPA vacuuming alone: dust (55.5%), PAHs (58.6%), and HDM allergens (80.8%), although the difference was statistically significant only for dust and PAHs. We conclude that intensive HEPA vacuum cleaning substantially reduced the loading of PAHs and HDM allergens in carpets in these urban homes and that dry steam cleaning added modestly to cleaning effectiveness. PMID:19137159

Investigating steam penetration using thermometric methods in dental handpieces with narrow internal lumens during sterilizing processes with non-vacuum or vacuum processes.

PubMed

Winter, S; Smith, A; Lappin, D; McDonagh, G; Kirk, B

2017-12-01

Dental handpieces are required to be sterilized between patient use. Vacuum steam sterilization processes with fractionated pre/post-vacuum phases or unique cycles for specified medical devices are required for hollow instruments with internal lumens to assure successful air removal. Entrapped air will compromise achievement of required sterilization conditions. Many countries and professional organizations still advocate non-vacuum sterilization processes for these devices. To investigate non-vacuum downward/gravity displacement, type-N steam sterilization of dental handpieces, using thermometric methods to measure time to achieve sterilization temperature at different handpiece locations. Measurements at different positions within air turbines were undertaken with thermocouples and data loggers. Two examples of widely used UK benchtop steam sterilizers were tested: a non-vacuum benchtop sterilizer (Little Sister 3; Eschmann, Lancing, UK) and a vacuum benchtop sterilizer (Lisa; W&H, Bürmoos, Austria). Each sterilizer cycle was completed with three handpieces and each cycle in triplicate. A total of 140 measurements inside dental handpiece lumens were recorded. The non-vacuum process failed (time range: 0-150 s) to reliably achieve sterilization temperatures within the time limit specified by the international standard (15 s equilibration time). The measurement point at the base of the handpiece failed in all test runs (N = 9) to meet the standard. No failures were detected with the vacuum steam sterilization type B process with fractionated pre-vacuum and post-vacuum phases. Non-vacuum downward/gravity displacement, type-N steam sterilization processes are unreliable in achieving sterilization conditions inside dental handpieces, and the base of the handpiece is the site most likely to fail. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Effect of sugar additives on stability of human serum albumin during vacuum foam drying and storage.

PubMed

Hajare, A A; More, H N; Pisal, S S

2011-11-01

No literature on the protein stabilization of human serum albumin (HSA) by vacuum foam drying (VFD) has been reported. The purpose of this study was to investigate the effect of sugar-additive systems on the stability of HSA by VFD. For the assessment, HSA was formulated with sucrose and mannitol, respectively, alone or in combination with stabilizers, which were vacuum foam dried and stored at 25C. Protein content of the resulting dried formulations was analyzed by Lowry method. Fourier-transform infrared spectroscopy (FT-IR) analysis of the HSA secondary structure showed apparent protein structure-stabilizing effects of the amorphous sugar and phosphate combination during the VFD. In particular, sucrose-sodium phosphate monobasic mixture provide an interesting alternative to pure saccharide formulations due to their high glass transition temperatures and their increased ability to maintain a low melting transition temperature in the presence of small amounts of water. Inhibition of the sucrose crystallization in solutions under vacuum resulted in highly amorphous sucrose. Changes in the endothermic melting transition suggested reduced sucrose molecular mobility with increase in the sodium phosphate ratio. The addition of phosphate salts to sugar systems has several interesting features that merit its consideration in formulations to protect dehydrated labile biomaterials. In conclusion, our data suggest that sucrose and phosphate as additives seem to protect HSA during VFD better than lyophilized products and also maintain its stability in the VFD state during storage.

Vacuum-sealed microcavity formed from suspended graphene by using a low-pressure dry-transfer technique

NASA Astrophysics Data System (ADS)

Takahashi, K.; Ishida, H.; Sawada, K.

2018-01-01

We report the development of a microcavity drum sealed by suspended graphene. The drum is fabricated by using a low-pressure dry-transfer technique, which involves vacuum de-aeration between a graphene sheet and a substrate and raising the temperature to above the glass transition of the supporting poly(methyl methacrylate) film, which serves to increase the real contact area. The result is a suspended graphene sheet with a maximum diameter of 48.6 μm. The Raman spectrum of the suspended graphene has a 2D/G ratio of 1.79 and a few D peaks, which suggests that the material is high-quality single-layer graphene. The dry-transfer technique yields a vacuum-sealed microcavity drum 1.1 μm deep up to 4.5 μm in diameter. The Raman shift indicates that the suspended graphene is subjected to a tensile strain of 0.05%, which is attributed to the pressure difference between the evacuated cavity and the exterior gas.

Improved shelf life of dried Beauveria bassiana blastospores using convective drying and active packaging processes.

PubMed

Mascarin, Gabriel Moura; Jackson, Mark A; Behle, Robert W; Kobori, Nilce N; Júnior, Ítalo Delalibera

2016-10-01

The yeast form (blastospore) of the dimorphic insect-pathogenic fungus Beauveria bassiana can be rapidly produced using liquid fermentation methods but is generally unable to survive rapid dehydration processes or storage under non-refrigerated conditions. In this study, we evaluated the influence of two convective drying methods, various modified atmosphere packaging systems, and storage temperatures on the desiccation tolerance, storage stability, and virulence of blastospores of B. bassiana ESALQ 1432. All blastospore formulations were dried to <5 % water content equivalent to aw < 0.3. The viability of B. bassiana blastospores after air drying and spray drying was greater than 80 %. Vacuum-packaged blastospores remained viable longer when stored at 4 °C compared with 28 °C with virtually no loss in viability over 9 months regardless the drying method. When both oxygen and moisture scavengers were added to sealed packages of dried blastospore formulations stored at 28 °C, viability was significantly prolonged for both air- and spray-dried blastospores. The addition of ascorbic acid during spray drying did not improve desiccation tolerance but enhanced cell stability (∼twofold higher half-life) when stored at 28 °C. After storage for 4 months at 28 °C, air-dried blastospores produced a lower LC80 and resulted in higher mortality to whitefly nymphs (Bemisia tabaci) when compared with spray-dried blastospores. These studies identified key storage conditions (low aw and oxygen availability) that improved blastospore storage stability at 28 °C and will facilitate the commercial development of blastospores-based bioinsecticides.

Moisture Sorption and Thermodynamic Properties of Vacuum-Dried Capsosiphon fulvescens Powder

PubMed Central

Zuo, Li; Rhim, Jong-Whan; Lee, Jun Ho

2015-01-01

The moisture sorption isotherms of vacuum-dried edible green alga (Capsosiphon fulvescens) powders were determined at 25, 35, and 45°C and water activity (aw) in the range of 0.11~0.94. An inversion effect of temperature was found at high water activity (>0.75). Various mathematical models were fitted to the experimental data, and Brunauer, Emmett, and Teller model was found to be the most suitable model describing the relationship between equilibrium moisture content and water activity (<0.45). Henderson model could also provide excellent agreement between the experimental and predicted values despite of the intersection point. Net isosteric heat of adsorption decreased from 15.77 to 9.08 kJ/mol with an increase in equilibrium moisture content from 0.055 to 0.090 kg H2O/kg solids. The isokinetic temperature (Tβ) was 434.79 K, at which all the adsorption reactions took place at the same rate. The enthalpy-entropy compensation suggested that the mechanism of the adsorption process was shown to be enthalpy-driven. PMID:26451360

Effect of low-temperature preservation on the quality of vacuum-packaged dry-cured ham: Refrigerated boneless ham and frozen ham cuts.

PubMed

Cilla, Irene; Martínez, Luis; Beltrán, José Antonio; Roncalés, Pedro

2006-05-01

The effect of storage on dry-cured ham quality was studied. Sixteen vacuum-packaged boneless dry-cured hams and sixteen vacuum-packaged dry-cured ham cuts were stored in darkness under refrigeration (4±2°C; 8 months) or freezing (-18±1°C; 24 months), respectively. Instrumental colour and texture, physico-chemical and biochemical parameters, sensory profile and consumer acceptability and purchase satisfaction were measured throughout storage. The overall quality of refrigerated boneless dry-cured hams and frozen dry-cured ham cuts showed only limited changes throughout long-term storage. Significant changes involved loss of odour and flavour, increased adhesiveness and modification of hardness, the Semimembranosus muscle became tender while Biceps femoris became harder, leading to a higher textural homogeneity. In agreement with those changes, the overall acceptability assessed by a trained panel decreased throughout storage, though this was significant regarding only frozen hams. However, consumer evaluation of acceptability, as well as satisfaction with hypothetical purchasing, did not vary significantly throughout storage.

Degradation kinetics of cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside during hot air and vacuum drying in mulberry (Morus alba L.) fruit: A comparative study based on solid food system.

PubMed

Zhou, Mo; Chen, Qinqin; Bi, Jinfeng; Wang, Yixiu; Wu, Xinye

2017-08-15

The aim of this study is to ascertain the degradation kinetic of anthocyanin in dehydration process of solid food system. Mulberry fruit was treated by hot air and vacuum drying at 60 and 75°C. The contents of cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside were determined by using high performance liquid chromatography. Kinetic and thermodynamic parameters were calculated for analysing the degradation characteristics. Model fitting results showed monomeric anthocyanin degradations were followed the second-order kinetic. Vacuum drying presented high kinetic rate constants and low t 1/2 values. Thermodynamic parameters including the activation energy, enthalpy change and entropy change appeared significant differences between hot air and vacuum drying. Both heating techniques showed similar effects on polyphenol oxidase activities. These results indicate the anthocyanin degradation kinetic in solid food system is different from that in liquid and the oxygen can be regarded as a catalyst to accelerate the degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Intensification of the penicillin drying process based on the theory of short-term contact of material with a heat-exchange surface].

PubMed

Sadykov, R A; Migunov, V V

1987-01-01

The process of potassium benzylpenicillin vacuum drying was investigated. The kinetics of the process showed that a larger period of the drying process was needed for eliminating bound moisture. The influence of the angular velocity of the drier drum rotation on drying duration was studied in a short-term contact model. It was shown that intensity of drying increased with increasing velocity of the drum rotation. Experimental trials confirmed the conclusion and revealed adequacy of the relationship between the drying time and dispersion intensity in the short-term contact model. A qualitative dependence of the coefficient of convective heat exchange between the heating surface and the product on the angular velocity of the drier drum rotation was constructed.

[Optimization of vacuum belt drying process of Gardeniae Fructus in Reduning injection by Box-Behnken design-response surface methodology].

PubMed

Huang, Dao-sheng; Shi, Wei; Han, Lei; Sun, Ke; Chen, Guang-bo; Wu Jian-xiong; Xu, Gui-hong; Bi, Yu-an; Wang, Zhen-zhong; Xiao, Wei

2015-06-01

To optimize the belt drying process conditions optimization of Gardeniae Fructus extract from Reduning injection by Box-Behnken design-response surface methodology, on the basis of single factor experiment, a three-factor and three-level Box-Behnken experimental design was employed to optimize the drying technology of Gardeniae Fructus extract from Reduning injection. With drying temperature, drying time, feeding speed as independent variables and the content of geniposide as dependent variable, the experimental data were fitted to a second order polynomial equation, establishing the mathematical relationship between the content of geniposide and respective variables. With the experimental data analyzed by Design-Expert 8. 0. 6, the optimal drying parameter was as follows: the drying temperature was 98.5 degrees C , the drying time was 89 min, the feeding speed was 99.8 r x min(-1). Three verification experiments were taked under this technology and the measured average content of geniposide was 564. 108 mg x g(-1), which was close to the model prediction: 563. 307 mg x g(-1). According to the verification test, the Gardeniae Fructus belt drying process is steady and feasible. So single factor experiments combined with response surface method (RSM) could be used to optimize the drying technology of Reduning injection Gardenia extract.

Thermodynamic performance of multi-stage gradational lead screw vacuum pump

NASA Astrophysics Data System (ADS)

Zhao, Fan; Zhang, Shiwei; Sun, Kun; Zhang, Zhijun

2018-02-01

As a kind of dry mechanical vacuum pump, the twin-screw vacuum pump has an outstanding pumping performance during operation, widely used in the semiconductor industry. Compared with the constant lead screw (CLS) vacuum pump, the gradational lead screw (GLS) vacuum pump is more popularly applied in recent years. Nevertheless, not many comparative studies on the thermodynamic performance of GLS vacuum pump can be found in the literature. Our study focuses on one type of GLS vacuum pump, the multi-stage gradational lead screw (MGLS) vacuum pump, gives a detailed description of its construction and illustrates it with the drawing. Based on the structural analysis, the thermodynamic procedure is divided into four distinctive processes, including sucking process, transferring (compressing) process, backlashing process and exhausting process. The internal mechanism of each process is qualitatively illustrated and the mathematical expressions of seven thermodynamic parameters are given under the ideal situation. The performance curves of MGLS vacuum pump are plotted by MATLAB software and compared with those of the CLS vacuum pump in the same case. The results can well explain why the MGLS vacuum pump has more favorable pumping performance than the CLS vacuum pump in saving energy, reducing noise and heat dissipation.

Particle monitoring and control in vacuum processing equipment

NASA Astrophysics Data System (ADS)

Borden, Peter G., Dr.; Gregg, John

1989-10-01

Particle contamination during vacuum processes has emerged as the largest single source of yield loss in VLSI manufacturing. While a number of tools have been available to help understand the sources and nature of this contamination, only recently has it been possible to monitor free particle levels within vacuum equipment in real-time. As a result, a better picture is available of how particle contamination can affect a variety of processes. This paper reviews some of the work that has been done to monitor particles in vacuum loadlocks and in processes such as etching, sputtering and ion implantation. The aim has been to make free particles in vacuum equipment a measurable process parameter. Achieving this allows particles to be controlled using statistical process control. It will be shown that free particle levels in load locks correlate to wafer surface counts, device yield and process conditions, but that these levels are considerable higher during production than when dummy wafers are run to qualify a system. It will also be shown how real-time free particle monitoring can be used to monitor and control cleaning cycles, how major episodic events can be detected, and how data can be gathered in a format suitable for statistical process control.

Suitability of microwave drying for mealworms (Tenebrio molitor) as alternative to freeze drying: Impact on nutritional quality and colour.

PubMed

Lenaerts, S; Van Der Borght, M; Callens, A; Van Campenhout, L

2018-07-15

Freeze drying represents the current practice to stabilize mealworms, even though it is an energy demanding technique. Therefore, it was examined in the present study whether microwave drying could be a proper alternative. To this end, the impact of both drying techniques on the proximate composition, vitamin B 12 content, fatty acid profile, oxidation status and colour parameters of mealworms was investigated. Furthermore, the influence of the application of vacuum during microwave drying was studied. The different drying technologies resulted in small differences in the proximate composition, while the vitamin B 12 content was only reduced by microwave drying. The fat fraction of freeze dried mealworms showed a higher oxidation status than the fat of microwave dried mealworms. Application of a vacuum during the microwave drying process did not appear to offer advantages. This research shows that for mealworms microwave drying can be a proper alternative to freeze drying. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of implants coated with recombinant human bone morphogenetic protein-2 and vacuum-dried using the critical-size supraalveolar peri-implant defect model in dogs.

PubMed

Decker, John F; Lee, Jaebum; Cortella, Carlo Alberto; Polimeni, Giuseppe; Rohrer, Michael D; Wozney, John M; Hall, Jan; Susin, Cristiano; Wikesjö, Ulf M E

2010-12-01

Endosseous implants coated with recombinant human bone morphogenetic protein-2 (rhBMP-2) in a laboratory bench setting and air-dried induce relevant bone formation but also resident bone remodeling. Thus, the objective of this study is to evaluate the effect of implants fully or partially coated with rhBMP-2 and vacuum-dried using an industrial process on local bone formation and resident bone remodeling. Twelve male adult Hound Labrador mongrel dogs were used. Critical-size, supraalveolar, peri-implant defects received titanium porous oxide surface implants coated in their most coronal aspect with rhBMP-2 (coronal-load, six animals), or by immersion of the entire implant in a rhBMP-2 solution (soak-load, six animals) for a total of 30 μg rhBMP-2 per implant. All implants were vacuum-dried. The animals were sacrificed at 8 weeks for histometric evaluation. Clinical healing was unremarkable. Bone formation was not significantly affected by the rhBMP-2 application protocol. New bone height and area averaged (± SE) 3.2 ± 0.5 versus 3.6 ± 0.3 mm, and 2.3 ± 0.5 versus 2.6 ± 0.8 mm(2) for coronal-load and soak-load implants, respectively (P >0.05). The corresponding bone density and bone-implant contact registrations averaged 46.7% ± 5.8% versus 31.6% ± 4.4%, and 28% ± 5.6% versus 36.9% ± 3.4% (P >0.05). In contrast, resident bone remodeling was significantly influenced by the rhBMP-2 application protocol. Peri-implant bone density averaged 72.2% ± 2.1% for coronal-load versus 60.6% ± 4.7% for soak-load implants (P <0.05); the corresponding bone-implant contact averaged 70.7% ± 6.1% versus 47.2% ± 6.0% (P <0.05). Local application of rhBMP-2 and vacuum-drying using industrial process seems to be a viable technology to manufacture implants that support local bone formation and osseointegration. Coronal-load implants obviate resident bone remodeling without compromising local bone formation.

Quality assessment of microwave-vacuum dried material with the use of computer image analysis and neural model

NASA Astrophysics Data System (ADS)

Koszela, K.; OtrzÄ sek, J.; Zaborowicz, M.; Boniecki, P.; Mueller, W.; Raba, B.; Lewicki, A.; Przybył, K.

2014-04-01

The farming area for vegetables in Poland is constantly changed and modified. Each year the cultivation structure of particular vegetables is different. However, it is the cultivation of carrots that plays a significant role among vegetables. According to the Main Statistical Office (GUS), in 2012 carrot held second position among the cultivated root vegetables, and it was estimated at 835 thousand tons. In the world we are perceived as the leading producer of carrot, due to the fourth place in the ranking of global producers. Poland is the largest producer of this vegetable in the EU [1]. It is also noteworthy, that the demand for dried vegetables is still increasing. This tendency affects the development of drying industry in our country, contributing to utilization of the product surplus. Dried vegetables are used increasingly often in various sectors of food products industry, due to high nutrition value, as well as to changing alimentary preferences of consumers [2-3]. Dried carrot plays a crucial role among dried vegetables, because of its wide scope of use and high nutrition value. It contains a lot of carotene and sugar present in the form of crystals. Carrot also undergoes many different drying processes, which makes it difficult to perform a reliable quality assessment and classification of this dried material. One of many qualitative properties of dried carrot, having important influence on a positive or negative result of the quality assessment, is color and shape. The aim of the research project was to develop a method for the analysis of microwave-vacuum dried carrot images, and its application for the classification of individual fractions in the sample studied for quality assessment. During the research digital photographs of dried carrot were taken, which constituted the basis for assessment performed by a dedicated computer programme developed as a part of the research. Consequently, using a neural model, the dried material was classified [4-6].

Vacuum pull down method for an enhanced bonding process

DOEpatents

Davidson, James C.; Balch, Joseph W.

1999-01-01

A process for effectively bonding arbitrary size or shape substrates. The process incorporates vacuum pull down techniques to ensure uniform surface contact during the bonding process. The essence of the process for bonding substrates, such as glass, plastic, or alloys, etc., which have a moderate melting point with a gradual softening point curve, involves the application of an active vacuum source to evacuate interstices between the substrates while at the same time providing a positive force to hold the parts to be bonded in contact. This enables increasing the temperature of the bonding process to ensure that the softening point has been reached and small void areas are filled and come in contact with the opposing substrate. The process is most effective where at least one of the two plates or substrates contain channels or grooves that can be used to apply vacuum between the plates or substrates during the thermal bonding cycle. Also, it is beneficial to provide a vacuum groove or channel near the perimeter of the plates or substrates to ensure bonding of the perimeter of the plates or substrates and reduce the unbonded regions inside the interior region of the plates or substrates.

Interruption of a dry-type transformer in no-load by a vacuum circuit-breaker

NASA Astrophysics Data System (ADS)

Vandenheuvel, W. M. C.; Daalder, J. E.; Boone, M. J. M.; Wilmes, L. A. H.

1983-08-01

Overvoltages generated during interruption of a dry type delta-star connected transformer in no load by a vacuum breaker were studied. During interruption of inrush current 37% of the phase-to-ground overvoltages were 5 pu, and 6% 7 pu. Comparison of experimental and theoretical results using Boyle's model shows no discrepancy for inrush currents and clean overvoltages from the steady-state interruption. Overvoltages due to repetitive reignitions (not covered by Boyle's model) are higher than the calculated values during steady-state switching.

Space Technology for Crop Drying

NASA Technical Reports Server (NTRS)

1980-01-01

McDonnell Douglas came up with a new method of drying agricultural crops derived from vacuum chamber technology called MIVAC, a compression of microwave vacuum drying system. A distant cousin of the home microwave oven, MIVAC dries by means of electrically- generated microwaves introduced to a crop-containing vacuum chamber. Microwaves remove moisture quickly and the very low pressure atmosphere in the chamber permits effective drying at much lower than customary temperatures. Thus energy demand is doubly reduced by lower heat requirement and by the shorter time electric power is needed.

Drying of restructured chips made from the old stalks of Asparagus officinalis: impact of different drying methods.

PubMed

Liu, Zhenbin; Zhang, Min; Wang, Yuchuan

2016-06-01

Old stalks of Asparagus officinalis, which account for one third of the total length of each spear, are always discarded as waste. To make full use of the resource, a kind of restructured Asparagus officinalis chip was made. The effects of pulse-spouted microwave-assisted vacuum drying (PSMVD), microwave-assisted vacuum drying (MVD) and vacuum drying (VD) on texture, color and other quality parameters of restructured chips were then studied to obtain high-quality dried chips. Results indicated that the drying time was significantly affected by drying methods, and PSMVD had much better drying uniformity than MVD. The expansion ratio and crispness of chips increased with increasing microwave power and vacuum degree. The browning reaction of samples in VD was more serious, which was confirmed by the results of color test and electronic nose. The PSMVD drying method showed much better drying uniformity than MVD. The dried chips obtained by PSMVD showed optimal quality and were more readily accepted by consumers. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Assessment of Performance of the Industrial Process of Bulk Vacuum Packaging of Raw Meat with Nondestructive Optical Oxygen Sensing Systems.

PubMed

Kelly, Caroline A; Cruz-Romero, Malco; Kerry, Joseph P; Papkovsky, Dmitri P

2018-05-02

The commercially-available optical oxygen-sensing system Optech-O₂ Platinum was applied to nondestructively assess the in situ performance of bulk, vacuum-packaged raw beef in three ~300 kg containers. Twenty sensors were attached to the inner surface of the standard bin-contained laminate bag (10 on the front and back sides), such that after filling with meat and sealing under vacuum, the sensors were accessible for optical interrogation with the external reader device. After filling and sealing each bag, the sensors were measured repetitively and nondestructively over a 15-day storage period at 1 °C, thus tracking residual oxygen distribution in the bag and changes during storage. The sensors revealed a number of unidentified meat quality and processing issues, and helped to improve the packaging process by pouring flakes of dry ice into the bag. Sensor utility in mapping the distribution of residual O₂ in sealed bulk containers and optimising and improving the packaging process, including handling and storage of bulk vacuum-packaged meat bins, was evident.

Wet/Dry Vacuum Cleaner

NASA Technical Reports Server (NTRS)

Reimers, Harold; Andampour, Jay; Kunitser, Craig; Thomas, Ike

1995-01-01

Vacuum cleaner collects and retains dust, wet debris, and liquids. Designed for housekeeping on Space Station Freedom, it functions equally well in normal Earth Gravity or in microgravity. Generates acoustic noise at comfortably low levels and includes circuitry that reduces electromagnetic interference to other electronic equipment. Draws materials into bag made of hydrophobic sheet with layers of hydrophilic super-absorbing pads at downstream end material. Hydrophilic material can gel many times its own weight of liquid. Blower also provides secondary airflow to cool its electronic components.

Evaluation of Double-Vacuum-Bag Process For Composite Fabrication

NASA Technical Reports Server (NTRS)

Hou, T. H.; Jensen, B. J.

2004-01-01

A non-autoclave vacuum bag process using atmospheric pressure alone that eliminates the need for external pressure normally supplied by an autoclave or a press is an attractive method for composite fabrication. This type of process does not require large capital expenditures for tooling and processing equipment. In the molding cycle (temperature/pressure profile) for a given composite system, the vacuum application point has to be carefully selected to achieve the final consolidated laminate net shape and resin content without excessive resin squeeze-out. The traditional single-vacuum- bag (SVB) process is best suited for molding epoxy matrix based composites because of their superior flow and the absence of reaction by-products or other volatiles. Other classes of materials, such as polyimides and phenolics, generate water during cure. In addition, these materials are commonly synthesized as oligomers using solvents to facilitate processability. Volatiles (solvents and reaction byproducts) management therefore becomes a critical issue. SVB molding, without additional pressure, normally fails to yield void-free quality composites for these classes of resin systems. A double-vacuum- bag (DVB) process for volatile management was envisioned, designed and built at the NASA Langley Research Center. This experimental DVB process affords superior volatiles management compared to the traditional SVB process. Void-free composites are consistently fabricated as measured by C-scan and optical photomicroscopy for high performance polyimide and phenolic resins.

Redesigning the continuous vacuum sealer packaging machine to improve the processing speed

NASA Astrophysics Data System (ADS)

Belo, J. B.; Widyanto, S. A.; Jamari, J.

2017-01-01

Vacuum sealer as a product packaging tool of food products to be able to vacuum air inside the plastic which is filled with food products and it causes the pressure lower. In this condition, the optimal heating temperature is reached in a shorter time, so that damage on plastic sealer of vacuumed food products could be prevented to be more effective and efficient. The purpose of this redesigning is to design a vacuum sealer packaging machine continuously through a conveyor mechanism on the packaging quality, time of processing speed of vacuuming food product in the plastic package. This designing process is conducted through several steps of designing and constructing tools until the products are ready to operate. Data analysis is done through quality test of vacuum and sealer to the plastic thickness of 75 µm, 80 µm, and 100 µm with temperature of 170°C, 180°C, 190°C and vacuum duration of 5 seconds, 8 seconds, and 60 seconds. Results of this designing process indicate that vacuum sealer works practically and more optimally with the time of vacuum processing speed of 0 to 1 minute/s; whereas, the pressure of vacuuming suction is until 1e-5 MPa. The results of tensile strength test are at a maximum of 32,796 (N/mm2) and a minimum of 20,155 (N/mm2) and the analysis of plastic composite with EDX. This result shows that the vacuum pressure and the quality of vacuum sealer are better and more efficient.

Failure of non-vacuum steam sterilization processes for dental handpieces.

PubMed

Winter, S; Smith, A; Lappin, D; McDonagh, G; Kirk, B

2017-12-01

Dental handpieces are used in critical and semi-critical operative interventions. Although some dental professional bodies recommend that dental handpieces are sterilized between patient use there is a lack of clarity and understanding of the effectiveness of different steam sterilization processes. The internal mechanisms of dental handpieces contain narrow lumens (0.8-2.3 mm) which can impede the removal of air and ingress of saturated steam required to achieve sterilization conditions. To identify the extent of sterilization failure in dental handpieces using a non-vacuum process. In-vitro and in-vivo investigations were conducted on widely used UK bench-top steam sterilizers and three different types of dental handpieces. The sterilization process was monitored inside the lumens of dental handpieces using thermometric (TM; dataloggers), chemical indicator (CI), and biological indicator (BI) methods. All three methods of assessing achievement of sterility within dental handpieces that had been exposed to non-vacuum sterilization conditions demonstrated a significant number of failures [CI: 8/3024 (fails/no. of tests); BI: 15/3024; TM: 56/56] compared to vacuum sterilization conditions (CI: 2/1944; BI: 0/1944; TM: 0/36). The dental handpiece most likely to fail sterilization in the non-vacuum process was the surgical handpiece. Non-vacuum sterilizers located in general dental practice had a higher rate of sterilization failure (CI: 25/1620; BI: 32/1620; TM: 56/56) with no failures in vacuum process. Non-vacuum downward/gravity displacement, type N steam sterilizers are an unreliable method for sterilization of dental handpieces in general dental practice. The handpiece most likely to fail sterilization is the type most frequently used for surgical interventions. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Apple snack enriched with L-arginine using vacuum impregnation/ohmic heating technology.

PubMed

Moreno, Jorge; Echeverria, Julian; Silva, Andrea; Escudero, Andrea; Petzold, Guillermo; Mella, Karla; Escudero, Carlos

2017-07-01

Modern life has created a high demand for functional food, and in this context, emerging technologies such as vacuum impregnation and ohmic heating have been applied to generate functional foods. The aim of this research was to enrich the content of the semi-essential amino acid L-arginine in apple cubes using vacuum impregnation, conventional heating, and ohmic heating. Additionally, combined vacuum impregnation/conventional heating and vacuum impregnation/ohmic heating treatments were evaluated. The above treatments were applied at 30, 40 and 50  ℃ and combined with air-drying at 40 ℃ in order to obtain an apple snack rich in L-arginine. Both the impregnation kinetics of L-arginine and sample color were evaluated. The impregnated samples created using vacuum impregnation/ohmic heating at 50 ℃ presented a high content of L-arginine, an effect attributed primarily to electropermeabilization. Overall, vacuum impregnation/ohmic heating treatment at 50 ℃, followed by drying at 40 ℃, was the best process for obtaining an apple snack rich in L-arginine.

Boiling process modelling peculiarities analysis of the vacuum boiler

NASA Astrophysics Data System (ADS)

Slobodina, E. N.; Mikhailov, A. G.

2017-06-01

The analysis of the low and medium powered boiler equipment development was carried out, boiler units possible development directions with the purpose of energy efficiency improvement were identified. Engineering studies for the vacuum boilers applying are represented. Vacuum boiler heat-exchange processes where boiling water is the working body are considered. Heat-exchange intensification method under boiling at the maximum heat- transfer coefficient is examined. As a result of the conducted calculation studies, heat-transfer coefficients variation curves depending on the pressure, calculated through the analytical and numerical methodologies were obtained. The conclusion about the possibility of numerical computing method application through RPI ANSYS CFX for the boiling process description in boiler vacuum volume was given.

Effect of drying methods (microwave vacuum, freeze, hot air and sun drying) on physical, chemical and nutritional attributes of five pepper (Capsicum annuum var. annuum) cultivars.

PubMed

Maurya, Vaibhav Kumar; Gothandam, Kodiveri Muthukaliannan; Ranjan, Vijay; Shakya, Amita; Pareek, Sunil

2018-07-01

A randomized block design experiment was performed to investigate the influence of drying on the physical, chemical and nutritional quality attributes of five prominent cultivars of India under sun drying (SD) (mean temperature 35.5 °C, average daily radiation 5.26 kW h m -2 and mean relative humidity 73.66% RH), hot air drying (HD) at 65 °C, microwave vacuum drying (MVD) (800 W, 5 kPa) and freeze drying (FD) (-50 °C, 5 kPa). Water activity, pH, total phenolic content (TPC), ascorbic acid (AA), capsaicin, β-carotene, color and Scoville heat unit were studied. TPC, AA, capsaicin content, β-carotene, color and water activity were significantly affected by the drying method. FD was observed to be most efficient in minimizing the loss of color, capsaicin and β-carotene. The hotness of analyzed samples decreased in the order 'Bird's Eye' > 'Sannam S4' > 'CO-4' > 'PLR-1' > 'PKM-1' among the studied cultivars, and FD > MVD > HD > SD among the drying methods. The FD method was observed to be the most efficient drying method for retaining capsaicin content over other drying methods (SD, HD, MVD), whereas MVD was found to be most efficient in minimizing the loss to nutritional attributes for all five pepper cultivars. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Effect of Sol Concentration, Aging and Drying Process on Cerium Stabilization Zirconium Gel Produced by External Gelation

NASA Astrophysics Data System (ADS)

Sukarsono, R.; Rachmawati, M.; Susilowati, S. R.; Husnurrofiq, D.; Nurwidyaningrum, K.; Dewi, A. K.

2018-02-01

Cerium Stabilized Zirconium gel has been prepared using external gelation process. As the raw materials was used ZrO(NO3)2 and Ce(NO3)4 nitrate salt which was dissolved with water into Zr-Ce nitrate mixture. The concentration of the nitrate salt mixture in the sol solution was varied by varying the concentration of zirconium and cerium nitrate in the sol solution and the addition of PVA and THFA to produce a sol with a viscosity of 40-60 cP. The viscosity range of 40-60cP is the viscosity of the sol solution that was easy to produce a good gel in the gelation apparatus. Sol solution was casted in a gelation column equipped with following tools: a 1 mm diameter drip nozzle which was vibrated to adjust the best frequency and amplitude of vibration, a flow meter to measure the flow rate of sol, flowing of NH3 gas to presolidification process. Gelation column was contained NH4OH solution as gelation medium and gel container to collect gel product. Gel obtained from the gelation process than processed with ageing, washing, drying and calcinations to get round gel and not broken at calcinations up to 500°C. The parameters observed in this research are variation of Zr nitrate concentration, Ce nitrate concentration, ratio of Zr and Ce in the sol and ageing and drying process method which was appropriate to get a good gel. From the gelation processes that has been done, it can be seen that with the presolidification process can be obtained a round gel and without presolidification process, produce not round gel. In the process of ageing to get not broken gel, ageing was done on the rotary flask so that during the ageing, gels rotate in gelation media. Gels, then be washed by dilute ammonium nitrate, demireralized water and iso prophyl alcohol. The washed gel was then dried by vacuum drying to form pores on the gel which become the path for the gases resulting from decomposition of the gel to exit the gel. Vacuum drying can prevent cracking because the pores allow the gel

Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Kai; Li, Ruixin; Jiang, Wenxue, E-mail: jiangortholivea@sina.cn

In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher thanmore » those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.« less

Survival of experimentally induced Toxoplasma gondii tissue cysts in vacuum packed goat meat and dry fermented goat meat sausages.

PubMed

Neumayerová, Helena; Juránková, Jana; Saláková, Alena; Gallas, Leo; Kovařčík, Kamil; Koudela, Břetislav

2014-05-01

Ingestion of raw or undercooked meat is a potential source of human toxoplasmosis. The aim of this study was to determine the viability of Toxoplasma gondii cysts in vacuum packed (VP) goat meat and in dry fermented sausages (DFS), and evaluate certain physical and chemical parameters, like water activity (aw), pH value, content of salt, dry matter and fat. A portion of muscle tissue from experimentally infected animals was used for production of VP meat with or without addition of 2.5% curing salt, and stored at 4 °C or at -20 °C. Results of bioassay showed that, samples of vacuum packed Toxoplasma positive meat without salt addition were alive after six weeks at 4 °C. Incubation at -20 °C supported the viability after 3 h, but not after 4 h. After 7 days in 2.5% of curing salt, samples of T. gondii VP goat meat were still viable, but not after 14 days at 4 °C. All the DFS samples were not positive for infective cysts which mean that, they do not pose a risk of T. gondii transmission. These data suggest that vacuum packaging increases the survival of T. gondii cysts. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of high pressure application (400 and 900 MPa) and refrigerated storage time on the oxidative stability of sliced skin vacuum packed dry-cured ham.

PubMed

Clariana, Maria; Guerrero, Luis; Sárraga, Carmen; Garcia-Regueiro, José A

2012-02-01

The effect of high pressure processing at 400 MPa and 900 MPa on the oxidative stability of sliced and vacuum packaged commercial dry-cured ham was determined by analyzing the antioxidant enzyme activities, TBARS levels (thiobarbituric acid reactive substances), vitamin E content and physicochemical characteristics during refrigerated storage for 50 days in different light conditions. In dry-cured ham pressurized at 400 MPa color changes and sensory analyses were also assessed. The high pressure process at 900 MPa produced a decrease in superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities and increased vitamin E content. In contrast, pressurization at 400 MPa, increased SOD activity, and showed no effect on vitamin E content and GSHPx activity. In general the physicochemical parameters determined (fat, moisture and collagen) were unaffected by pressurization. Treatment at 400 MPa increased the instrumental color measurement of lightness (L* values, CIELAB). This level of pressure also modified the hardness, chewiness, saltiness and color intensity. These changes of the sensory attributes in dry-cured ham were significant, but small. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evaluation of the impact of food matrix change on the in vitro bioaccessibility of carotenoids in pumpkin (Cucurbita moschata) slices during two drying processes.

PubMed

Zhang, Zhongyuan; Wang, Xiaoyan; Li, Yixiang; Wei, Qiuyu; Liu, Chunju; Nie, Meimei; Li, Dajing; Xiao, Yadong; Liu, Chunquan; Xu, Lang; Zhang, Min; Jiang, Ning

2017-12-13

The food matrix is a limiting factor in determining the bioaccessibility of carotenoids. The impact of food matrix change on the bioaccessibility of carotenoids during drying processes is still unknown. The effect of intermittent microwave vacuum-assisted drying (IMVD) and hot air drying (HAD) on the in vitro liberation and micellization of carotenoids in pumpkin slices was studied. This variable depended on the changes of the matrix driven by the drying process. Different changes in the cell morphology and carotenoid distribution of pumpkin slices during the two processing methods were observed. For IMVD, cell wall degradation and complete chromoplast organelle disruption contributed to the improvement in the liberation and micellization of carotenoids. In the HAD-dried sample, large pigment aggregates hindered the liberation of carotenoids. The carotenoid level in the micellar fraction appeared to be lower than that in the aqueous supernatant during the two processes, suggesting that the new obstacles formed during processing and/or digestion hindered the incorporation of carotenoids in mixed micelles.

Physicochemical properties of whole fruit plum powders obtained using different drying technologies.

PubMed

Michalska, Anna; Wojdyło, Aneta; Lech, Krzysztof; Łysiak, Grzegorz P; Figiel, Adam

2016-09-15

Physicochemical quality parameters of plum powders obtained by applying conventional drying methods and their combination devised to process plums were evaluated. The effect of freeze-drying (FD), vacuum drying (VD), convective drying (CD), microwave-vacuum drying (MVD) and combination of convective pre-drying and microwave finish-drying (CPD-MVFD) affected physical (bulk density, porosity, colour, solubility) and chemical (polyphenolic compounds determined by UPLC and antioxidant capacity by TEAC ABTS and FRAP methods) properties of plum powders. The MVD at 1.2 W g(-1) and a novel combination for plum powders production - CPD-MVFD at 70 °C/1.2 W g(-1) allowed the best preservation of phenolic compounds and increased the efficiency of production. Results obtained support the use of MVD and its combination for better quality of dried plum products. The study proved that the determination of the browning index and HMF level (formed via Maillard reaction) might be good tool for monitoring the thermal processing of plum powders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Double Vacuum Bag Process for Resin Matrix Composite Manufacturing

NASA Technical Reports Server (NTRS)

Hou, Tan-Hung (Inventor); Jensen, Brian J. (Inventor)

2007-01-01

A double vacuum bag molding assembly with improved void management and laminate net shape control which provides a double vacuum enviromnent for use in fabricating composites from prepregs containing air and/or volatiles such as reactive resin matrix composites or composites from solvent containing prepregs with non-reactive resins matrices. By using two vacuum environments during the curing process, a vacuum can be drawn during a B-stage of a two-step cycle without placing the composite under significant relative pressure. During the final cure stage, a significant pressure can be applied by releasing the vacuum in one of the two environments. Inner and outer bags are useful for creating the two vacuum environments with a perforated tool intermediate the two. The composite is placed intermediate a tool plate and a caul plate in the first environment with the inner bag and tool plate defining the first environment. The second environment is characterized by the outer bag which is placed over the inner bag and the tool plate.

CFD simulation of a dry scroll vacuum pump with clearances, solid heating and thermal deformation

NASA Astrophysics Data System (ADS)

Spille-Kohoff, A.; Hesse, J.; Andres, R.; Hetze, F.

2017-08-01

Although dry scroll vacuum pumps (DSPV) are essential devices in many different industrial processes, the CFD simulation of such pumps is not widely used and often restricted to simplified cases due to its complexity: The working principle with a fixed and an orbiting scroll leads to working chambers that are changing in time and are connected through moving small radial and axial clearances in the range of 10 to 100 μm. Due to the low densities and low mass flow rates in vacuum pumps, it is important to include heat transfer towards and inside the solid components. Solid heating is very slow compared to the scroll revolution speed and the gas behaviour, thus a special workflow is necessary to reach the working conditions in reasonable simulation times. The resulting solid temperature is then used to compute the thermal deformation, which usually results in gap size changes that influence leakage flows. In this paper, setup steps and results for the simulation of a DSVP are shown and compared to theoretical and experimental results. The time-varying working chambers are meshed with TwinMesh, a hexahedral meshing programme for positive displacement machines. The CFD simulation with ANSYS CFX accounts for gas flow with compressibility and turbulence effects, conjugate heat transfer between gas and solids, and leakage flows through the clearances. Time-resolved results for torques, chamber pressure, mass flow, and heat flow between gas and solids are shown, as well as time- and space-resolved results for pressure, velocity, and temperature for different operating conditions of the DSVP.

Ethanol production from food waste at high solids content with vacuum recovery technology.

PubMed

Huang, Haibo; Qureshi, Nasib; Chen, Ming-Hsu; Liu, Wei; Singh, Vijay

2015-03-18

Ethanol production from food wastes does not only solve environmental issues but also provides renewable biofuels. This study investigated the feasibility of producing ethanol from food wastes at high solids content (35%, w/w). A vacuum recovery system was developed and applied to remove ethanol from fermentation broth to reduce yeast ethanol inhibition. A high concentration of ethanol (144 g/L) was produced by the conventional fermentation of food waste without a vacuum recovery system. When the vacuum recovery is applied to the fermentation process, the ethanol concentration in the fermentation broth was controlled below 100 g/L, thus reducing yeast ethanol inhibition. At the end of the conventional fermentation, the residual glucose in the fermentation broth was 5.7 g/L, indicating incomplete utilization of glucose, while the vacuum fermentation allowed for complete utilization of glucose. The ethanol yield for the vacuum fermentation was found to be 358 g/kg of food waste (dry basis), higher than that for the conventional fermentation at 327 g/kg of food waste (dry basis).

Challenges to a blow/fill/seal process with airborne microorganisms having different resistances to dry heat.

PubMed

Poisson, Patrick; Sinclair, Colin S; Tallentire, Alan

2006-01-01

Controlled challenges with air dispersed microorganisms having widely different resistances to dry heat, carried out on 624 BFS machine processing growth medium, have shown that higher the heat resistance, the greater the extent of vial contamination. Differences in heat resistance affected also the extent of vial contamination when parison and vial formation were knowingly manipulated through changes made to each of three process variables, provision of ballooning air, mould vacuum delay, and parison extrusion rate. The findings demonstrate that, in this investigational system, exposure of challenge micoorganisms to heat inherent in the process has a controlling influence on vial contamination, an influence that could also control microbiological risk in production environments.

Drying process of fermented inulin fiber concentrate by Bifidobacterium bifidum as a dietary fiber source for cholesterol binder

NASA Astrophysics Data System (ADS)

Susilowati, Agustine; Aspiyanto, Ghozali, Muhammad

2017-11-01

Fermentation on inulin hydrolysate as fructooligosaccharides (FOS) by Bifidobacterium bifidum as a result of hydrolysis by inulase enzyme of Scopulariopsis sp.-CBS1 fungi has been performed to bind cholesterol. Their applications on preparation of fermented pour beverages was conducted via a series of concentration process using dead-end Stirred Ultrafiltration Cell (SUFC) mode at stirrer rotation of 400 rpm, room temperature and pressure of 40 psia for 0 minute (pre-concentration process) as concentrate (A) and 45 minutes as concentrate (B), and drying process using vacuum dryer at 30 °C and 22 cm Hg for 0, 8, 16, 24, 32, 40 and 48 hours. Based on optimization of Total Dietary Fiber (TDF), the best time of drying process was achieved for 40 hours. Long time of drying process would increase TDF and total solids, decreased total acids, and fluctuated dissolved protein and Cholesterol Binding Capacity (CBC). At the optimum condition of drying process was get fermented inulin fiber powder from concentration processes using both UF as pre process (0 minute) as concentrate (A) and UF for 45 minutes as concentrate (B) with compositions of total solids of 92.31 % and 93.67 %, TDF of 59.07 % (dry weight) and 69.28 %, total acids of 7.03 % and 7.5 %, dissolved protein of 3.95 mg/mL and 3.05 mg/mL, and CBC pH 2 15.71 mg/g and 16.8 mg/g, respectively. Concentration process through dead-end SUFC mode gave distribution of particles with better smoothness level than without through dead-end SUFC mode.

Determination of end point of primary drying in freeze-drying process control.

PubMed

Patel, Sajal M; Doen, Takayuki; Pikal, Michael J

2010-03-01

Freeze-drying is a relatively expensive process requiring long processing time, and hence one of the key objectives during freeze-drying process development is to minimize the primary drying time, which is the longest of the three steps in freeze-drying. However, increasing the shelf temperature into secondary drying before all of the ice is removed from the product will likely cause collapse or eutectic melt. Thus, from product quality as well as process economics standpoint, it is very critical to detect the end of primary drying. Experiments were conducted with 5% mannitol and 5% sucrose as model systems. The apparent end point of primary drying was determined by comparative pressure measurement (i.e., Pirani vs. MKS Baratron), dew point, Lyotrack (gas plasma spectroscopy), water concentration from tunable diode laser absorption spectroscopy, condenser pressure, pressure rise test (manometric temperature measurement or variations of this method), and product thermocouples. Vials were pulled out from the drying chamber using a sample thief during late primary and early secondary drying to determine percent residual moisture either gravimetrically or by Karl Fischer, and the cake structure was determined visually for melt-back, collapse, and retention of cake structure at the apparent end point of primary drying (i.e., onset, midpoint, and offset). By far, the Pirani is the best choice of the methods tested for evaluation of the end point of primary drying. Also, it is a batch technique, which is cheap, steam sterilizable, and easy to install without requiring any modification to the existing dryer.

Drying process strongly affects probiotics viability and functionalities.

PubMed

Iaconelli, Cyril; Lemetais, Guillaume; Kechaou, Noura; Chain, Florian; Bermúdez-Humarán, Luis G; Langella, Philippe; Gervais, Patrick; Beney, Laurent

2015-11-20

Probiotic formulations are widely used and are proposed to have a variety of beneficial effects, depending on the probiotic strains present in the product. The impact of drying processes on the viability of probiotics is well documented. However, the impact of these processes on probiotics functionality remains unclear. In this work, we investigated variations in seven different bacterial markers after various desiccation processes. Markers were composed of four different viability evaluation (combining two growth abilities and two cytometric measurements) and in three in vitro functionalities: stimulation of IL-10 and IL-12 production by PBMCs (immunomodulation) and bacterial adhesion to hexadecane. We measured the impact of three drying processes (air-drying, freeze-drying and spray-drying), without the use of protective agents, on three types of probiotic bacteria: Bifidobacterium bifidum, Lactobacillus plantarum and Lactobacillus zeae. Our results show that the bacteria respond differently to the three different drying processes, in terms of viability and functionality. Drying methods produce important variations in bacterial immunomodulation and hydrophobicity, which are correlated. We also show that adherence can be stimulated (air-drying) or inhibited (spray-drying) by drying processes. Results of a multivariate analysis show no direct correlation between bacterial survival and functionality, but do show a correlation between probiotic responses to desiccation-rewetting and the process used to dry the bacteria. Copyright © 2015 Elsevier B.V. All rights reserved.

Apollo Experiment Report: Lunar-Sample Processing in the Lunar Receiving Laboratory High-Vacuum Complex

NASA Technical Reports Server (NTRS)

White, D. R.

1976-01-01

A high-vacuum complex composed of an atmospheric decontamination system, sample-processing chambers, storage chambers, and a transfer system was built to process and examine lunar material while maintaining quarantine status. Problems identified, equipment modifications, and procedure changes made for Apollo 11 and 12 sample processing are presented. The sample processing experiences indicate that only a few operating personnel are required to process the sample efficiently, safely, and rapidly in the high-vacuum complex. The high-vacuum complex was designed to handle the many contingencies, both quarantine and scientific, associated with handling an unknown entity such as the lunar sample. Lunar sample handling necessitated a complex system that could not respond rapidly to changing scientific requirements as the characteristics of the lunar sample were better defined. Although the complex successfully handled the processing of Apollo 11 and 12 lunar samples, the scientific requirement for vacuum samples was deleted after the Apollo 12 mission just as the vacuum system was reaching its full potential.

Method for sequentially processing a multi-level interconnect circuit in a vacuum chamber

NASA Technical Reports Server (NTRS)

Routh, D. E.; Sharma, G. C. (Inventor)

1984-01-01

An apparatus is disclosed which includes a vacuum system having a vacuum chamber in which wafers are processed on rotating turntables. The vacuum chamber is provided with an RF sputtering system and a dc magnetron sputtering system. A gas inlet introduces various gases to the vacuum chamber and creates various gas plasma during the sputtering steps. The rotating turntables insure that the respective wafers are present under the sputtering guns for an average amount of time such that consistency in sputtering and deposition is achieved. By continuous and sequential processing of the wafers in a common vacuum chamber without removal, the adverse affects of exposure to atmospheric conditions are eliminated providing higher quality circuit contacts and functional device.

Impact of vacuum cooking process on the texture degradation of selected apple cultivars.

PubMed

Bourles, E; Mehinagic, E; Courthaudon, J L; Jourjon, F

2009-01-01

Thermal treatments are known to affect the textural properties of fruits and vegetables. This study was conducted to evaluate the influence of vacuum cooking process on the mechanical properties of various apple cultivars. A total of 10 apple cultivars were industrially processed by vacuum pasteurization at 95 degrees C for 25 min. The raw material was characterized by penetrometry, uniaxial double compression, soluble solid content, and titrable acidity. Textural properties of processed apples were analyzed by uniaxial double compression. As expected, for all cultivars, fruit resistance was lower after processing than before. Results showed that texture degradation due to vacuum pasteurization was different from one cultivar to another. Indeed, some cultivars, initially considered as the most resistant ones, such as Braeburn, were less suitable for processing, and became softer than others after thermal treatment. Consequently, it is worth noting that the texture classification of the investigated apple cultivars was changed by the vacuum-cooking process.

Modified atmosphere packaging and vacuum packaging for long period chilled storage of dry-cured Iberian ham.

PubMed

Parra, V; Viguera, J; Sánchez, J; Peinado, J; Espárrago, F; Gutierrez, J I; Andrés, A I

2010-04-01

Dry-cured Iberian ham slices were stored under vacuum and under four different modified atmospheres (60/40=60%N(2)+40%CO(2); 70/30=70%N(2)+30%CO(2); 80/20=80%N(2)+20%CO(2); argon=70%argon+30%CO(2)) at 4+/-1 degrees C during 120 days. Gas composition, moisture content, pH, colour, pigment content, and lipid stability were measured, as well as sensory and microbial analysis were carried out throughout storage. A loss of intensity of red colour (a(*)-values) was observed during storage in ham slices (P<0.05). Consistently, MbFe(II)NO content also decreased throughout storage (P>0.05). Slices of ham packed in 40%CO(2) (60/40) and 30%CO(2) (70/30) showed lower a(*)-values than the rest of the batches after 60 days (P<0.05), though differences were not evident after 120 days (P>0.05). TBARs values showed an upward trend during the storage of packaged slices (P<0.05). Vacuum-packed slices showed the lowest TBARs values and those packed with 40%CO(2), the highest. Sensory attributes did not vary significantly (P>0.05) throughout storage under refrigeration and packed either in vacuum or in modified atmospheres. No safety problems were detected in relation to the microbial quality in any case. 2009 Elsevier Ltd. All rights reserved.

Method for sequentially processing a multi-level interconnect circuit in a vacuum chamber

NASA Technical Reports Server (NTRS)

Routh, D. E.; Sharma, G. C. (Inventor)

1982-01-01

The processing of wafer devices to form multilevel interconnects for microelectronic circuits is described. The method is directed to performing the sequential steps of etching the via, removing the photo resist pattern, back sputtering the entire wafer surface and depositing the next layer of interconnect material under common vacuum conditions without exposure to atmospheric conditions. Apparatus for performing the method includes a vacuum system having a vacuum chamber in which wafers are processed on rotating turntables. The vacuum chamber is provided with an RF sputtering system and a DC magnetron sputtering system. A gas inlet is provided in the chamber for the introduction of various gases to the vacuum chamber and the creation of various gas plasma during the sputtering steps.

David Florida Laboratory Thermal Vacuum Data Processing System

NASA Technical Reports Server (NTRS)

Choueiry, Elie

1994-01-01

During 1991, the Space Simulation Facility conducted a survey to assess the requirements and analyze the merits for purchasing a new thermal vacuum data processing system for its facilities. A new, integrated, cost effective PC-based system was purchased which uses commercial off-the-shelf software for operation and control. This system can be easily reconfigured and allows its users to access a local area network. In addition, it provides superior performance compared to that of the former system which used an outdated mini-computer and peripheral hardware. This paper provides essential background on the old data processing system's features, capabilities, and the performance criteria that drove the genesis of its successor. This paper concludes with a detailed discussion of the thermal vacuum data processing system's components, features, and its important role in supporting our space-simulation environment and our capabilities for spacecraft testing. The new system was tested during the ANIK E spacecraft test, and was fully operational in November 1991.

Influence of pre-drying treatments on physicochemical and organoleptic properties of explosion puff dried jackfruit chips.

PubMed

Yi, Jianyong; Zhou, Linyan; Bi, Jinfeng; Chen, Qinqin; Liu, Xuan; Wu, Xinye

2016-02-01

The effects of hot air drying (AD), freeze drying (FD), infrared drying (IR), microwave drying (MV), vacuum drying (VD) as pre-drying treatments for explosion puff drying (EPD) on qualities of jackfruit chips were studied. The lowest total color differences (∆E) were found in the FD-, MV- and VD-EPD dried chips. Volume expansion effect (9.2 %) was only observed in the FD-EPD dried chips, which corresponded to its well expanded honeycomb microstructures and high rehydration rate. Compared with AD-, IR-, MV- and VD-EPD, the FD-EPD dried fruit chips exhibited lower hardness and higher crispness, indicative of a crispier texture. FD-EPD dried fruits also obtained high retentions of ascorbic acid, phenolics and carotenoids compared with that of the other puffed products. The results of sensory evaluation suggested that the FD-EPD was a more beneficial combination because it enhanced the overall qualities of jackfruit chips. In conclusion, the FD-EPD could be used as a novel combination drying method for processing valuable and/or high quality fruit chips.

Infrared pre-drying and dry-dehulling of walnuts for improved processing efficiency and product quality

USDA-ARS?s Scientific Manuscript database

The walnut industry is faced with an urgent need to improve post-harvest processing efficiency, particularly drying and dehulling operations. This research investigated the feasibility of dry-dehulling and infrared (IR) pre-drying of walnuts for improved processing efficiency and dried product quali...

Complex technology of vacuum-arc processing of structural material surface

NASA Astrophysics Data System (ADS)

Arustamov, V. N.; Ashurov, Kh. B.; Kadyrov, Kh. Kh.; Khudoikulov, I. Kh.

2015-08-01

The development of environmentally friendly and energy-resource-saving technologies based on vacuum arc discharge is a topical problem in science and engineering. In view of their unique properties, cathode spots of a vacuum arc induce cleaning of the surface of an article (cathode) from various contaminations and pulsed thermal action on the surface layers. These processes occur in complex with vacuum-arc deposition of coatings in the same technological cycle, which makes it possible to considerably increase the efficiency of methods for changing physical, mechanical, and chemical properties of the surface of steel articles, which considerably increase their service life. Analysis of the formation of the temperature regime of the surface during vacuum arc action and of the parameters of the deposited coating will make it possible to optimize the regimes of complex treatment of the surfaces of articles and is of considerable theoretical and practical importance.

Comparison of modified atmosphere packaging and vacuum packaging for long period storage of dry-cured ham: effects on colour, texture and microbiological quality.

PubMed

García-Esteban, Marta; Ansorena, Diana; Astiasarán, Iciar

2004-05-01

Slices of dry-cured hams (Biceps femoris muscle) were stored during 8 weeks under vacuum and modified atmospheres (100% N(2) and a mixture of 20% CO(2) and 80% N(2)) in order to study the modifications on colour, texture and microbial counts during that period. Lightness was found to be more stable when samples were stored with 20% CO(2) and 80% N(2) without statistical differences between vacuum and 100% N(2). A slight whiteness was observed in the vacuum packed samples. Yellowness increased during time in vacuum packed samples, although no differences were found among the three conditions at the end of the study. Redness values were not affected by time or by the packaging system. With regard to texture, values found for all samples were within the normal range for this type of products, although it was observed that modified atmosphere packaging preserved samples better from hardening than vacuum packaging. No safety problems were detected in relation to the microbial quality in any case. In general, no clear differences were found among the three packaging systems for colour, texture and microbial quality in the storage conditions studied.

Vacuum infusion manufacturing and experimental characterization of Kevlar/epoxy composites

NASA Astrophysics Data System (ADS)

Ricciardi, M. R.; Giordano, M.; Langella, A.; Nele, L.; Antonucci, V.

2014-05-01

Epoxy/Kevlar composites have been manufactured by conventional Vacuum Infusion process and the Pulse Infusion technique. Pulse Infusion allows to control the pressure of the vacuum bag on the dry fiber reinforcement by using a proper designed pressure distributor that induces a pulsed transverse action and promotes the through thickness resin flow. The realized composite panel have been mechanically characterized by performing tensile and short beam shear tests according with the ASTM D3039 and ASTM D2344/D 2344M standard respectively in order to investigate the effect of Pulse Infusion on the tensile strength and ILSS.

Vacuum infusion manufacturing and experimental characterization of Kevlar/epoxy composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricciardi, M. R.; Giordano, M.; Antonucci, V.

2014-05-15

Epoxy/Kevlar composites have been manufactured by conventional Vacuum Infusion process and the Pulse Infusion technique. Pulse Infusion allows to control the pressure of the vacuum bag on the dry fiber reinforcement by using a proper designed pressure distributor that induces a pulsed transverse action and promotes the through thickness resin flow. The realized composite panel have been mechanically characterized by performing tensile and short beam shear tests according with the ASTM D3039 and ASTM D2344/D 2344M standard respectively in order to investigate the effect of Pulse Infusion on the tensile strength and ILSS.

Microwave-assisted drying of blueberry (Vaccinium corymbosum L.) fruits: Drying kinetics, polyphenols, anthocyanins, antioxidant capacity, colour and texture.

PubMed

Zielinska, Magdalena; Michalska, Anna

2016-12-01

The aim of the study was to evaluate the effect of hot air convective drying (HACD), microwave vacuum drying (MWVD) and their combination (HACD+MWVD) on the drying kinetics, colour, total polyphenols, anthocyanins antioxidant capacity and texture of frozen/thawed blueberries. Drying resulted in reduction of total polyphenols content and antioxidant capacity (69 and 77%, respectively). The highest content of total polyphenols was noted after HACD at 90°C. Lower air temperature and prolonged exposure to oxygen resulted in greater degradation of polyphenols and antioxidant capacity. Drying processes caused a significant decrease (from 70 to 95%) in the content of anthocyanins. The highest content of anthocyanins and the strongest antioxidant capacity was found in blueberries dried using HACD at 90°C+MWVD. Among drying methods, HACD at 90°C+MWVD satisfied significant requirements for dried fruits i.e. short drying time and improved product quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Demonstrating Functional Equivalence of Pilot and Production Scale Freeze-Drying of BCG.

PubMed

Ten Have, R; Reubsaet, K; van Herpen, P; Kersten, G; Amorij, J-P

2016-01-01

Process analytical technology (PAT)-tools were used to monitor freeze-drying of Bacille Calmette-Guérin (BCG) at pilot and production scale. Among the evaluated PAT-tools, there is the novel use of the vacuum valve open/close frequency for determining the endpoint of primary drying at production scale. The duration of primary drying, the BCG survival rate, and the residual moisture content (RMC) were evaluated using two different freeze-drying protocols and were found to be independent of the freeze-dryer scale evidencing functional equivalence. The absence of an effect of the freeze-dryer scale on the process underlines the feasibility of the pilot scale freeze-dryer for further BCG freeze-drying process optimization which may be carried out using a medium without BCG.

Infrared Drying as a Quick Preparation Method for Dried Tangerine Peel

PubMed Central

Xu, Mingyue; Zhao, Chengying; Ahmad, Aftab; Zhang, Huijuan; Xiao, Hang

2017-01-01

To establish the most convenient and effective method to dry tangerine peels, different methods (sun drying, hot-air drying, freeze drying, vacuum drying, and medium- and short-wave infrared drying) were exploited. Our results indicated that medium- and short-wave infrared drying was the best method to preserve nutraceutical components; for example, vitamin C was raised to 6.77 mg/g (D.W.) from 3.39 mg/g (sun drying). Moreover, the drying time can be shortened above 96% compared with sun drying. Importantly, the efficiency of DPPH radical scavenging was enhanced from 26.66% to 55.92%. These findings would provide a reliable and time-saving methodology to produce high-quality dried tangerine peels. PMID:29348752

Effects of different drying methods on the product quality and volatile compounds of whole shiitake mushrooms.

PubMed

Tian, Yuting; Zhao, Yingting; Huang, Jijun; Zeng, Hongliang; Zheng, Baodong

2016-04-15

Various drying methods play important roles in the preservation of foods. However, how the different drying methods affect the quality of some foods is not clear. This paper evaluates the effects of hot air, vacuum, microwave, and microwave vacuum drying techniques on important qualities and volatile compounds of whole shiitake (Lentinus edodes) mushrooms. These four drying methods resulted in a significantly (p<0.05) increase in the content of total free amino acids and the relative content of sulfur compounds of dried products. Microwave vacuum drying helped to maintain larger amounts of taste-active amino acids, and improved nutrient retention and color attributes. Furthermore, the uniform honeycomb network created by microwave vacuum drying along with a less collapsed structure of dried samples can be used to explain the observed high rehydration ratio. Therefore, microwave vacuum drying should be a potential method for obtaining high-quality dried mushrooms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Variation of the Phytochemical Constituents and Antioxidant Activities of Zingiber officinale var. rubrum Theilade Associated with Different Drying Methods and Polyphenol Oxidase Activity.

PubMed

Ghasemzadeh, Ali; Jaafar, Hawa Z E; Rahmat, Asmah

2016-06-17

The effects of different drying methods (freeze drying, vacuum oven drying, and shade drying) on the phytochemical constituents associated with the antioxidant activities of Z. officinale var. rubrum Theilade were evaluated to determine the optimal drying process for these rhizomes. Total flavonoid content (TFC), total phenolic content (TPC), and polyphenol oxidase (PPO) activity were measured using the spectrophotometric method. Individual phenolic acids and flavonoids, 6- and 8-gingerol and shogaol were identified by ultra-high performance liquid chromatography method. Ferric reducing antioxidant potential (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used for the evaluation of antioxidant activities. The highest reduction in moisture content was observed after freeze drying (82.97%), followed by vacuum oven drying (80.43%) and shade drying (72.65%). The highest TPC, TFC, and 6- and 8-shogaol contents were observed in samples dried by the vacuum oven drying method compared to other drying methods. The highest content of 6- and 8-gingerol was observed after freeze drying, followed by vacuum oven drying and shade drying methods. Fresh samples had the highest PPO activity and lowest content of flavonoid and phenolic acid compounds compared to dried samples. Rhizomes dried by the vacuum oven drying method represent the highest DPPH (52.9%) and FRAP activities (566.5 μM of Fe (II)/g DM), followed by freeze drying (48.3% and 527.1 μM of Fe (II)/g DM, respectively) and shade drying methods (37.64% and 471.8 μM of Fe (II)/g DM, respectively) with IC50 values of 27.2, 29.1, and 34.8 μg/mL, respectively. Negative and significant correlations were observed between PPO and antioxidant activity of rhizomes. Vacuum oven dried rhizomes can be utilized as an ingredient for the development of value-added food products as they contain high contents of phytochemicals with valuable antioxidant potential.

Recent advances in drying and dehydration of fruits and vegetables: a review.

PubMed

Sagar, V R; Suresh Kumar, P

2010-01-01

Fruits and vegetables are dried to enhance storage stability, minimize packaging requirement and reduce transport weight. Preservation of fruits and vegetables through drying based on sun and solar drying techniques which cause poor quality and product contamination. Energy consumption and quality of dried products are critical parameters in the selection of drying process. An optimum drying system for the preparation of quality dehydrated products is cost effective as it shortens the drying time and cause minimum damage to the product. To reduce the energy utilization and operational cost new dimensions came up in drying techniques. Among the technologies osmotic dehydration, vacuum drying, freeze drying, superheated steam drying, heat pump drying and spray drying have great scope for the production of quality dried products and powders.

Demonstrating Functional Equivalence of Pilot and Production Scale Freeze-Drying of BCG

PubMed Central

ten Have, R.; Reubsaet, K.; van Herpen, P.; Kersten, G.; Amorij, J.-P.

2016-01-01

Process analytical technology (PAT)-tools were used to monitor freeze-drying of Bacille Calmette-Guérin (BCG) at pilot and production scale. Among the evaluated PAT-tools, there is the novel use of the vacuum valve open/close frequency for determining the endpoint of primary drying at production scale. The duration of primary drying, the BCG survival rate, and the residual moisture content (RMC) were evaluated using two different freeze-drying protocols and were found to be independent of the freeze-dryer scale evidencing functional equivalence. The absence of an effect of the freeze-dryer scale on the process underlines the feasibility of the pilot scale freeze-dryer for further BCG freeze-drying process optimization which may be carried out using a medium without BCG. PMID:26981867

The influence of lysozyme on mannitol polymorphism in freeze-dried and spray-dried formulations depends on the selection of the drying process.

PubMed

Grohganz, Holger; Lee, Yan-Ying; Rantanen, Jukka; Yang, Mingshi

2013-04-15

Freeze-drying and spray-drying are often applied drying techniques for biopharmaceutical formulations. The formation of different solid forms upon drying is often dependent on the complex interplay between excipient selection and process parameters. The purpose of this study was to investigate the influence of the chosen drying method on the solid state form. Mannitol-lysozyme solutions of 20mg/mL, with the amount of lysozyme varying between 2.5% and 50% (w/w) of total solid content, were freeze-dried and spray-dried, respectively. The resulting solid state of mannitol was analysed by near-infrared spectroscopy in combination with multivariate analysis and further, results were verified with X-ray powder diffraction. It was seen that the prevalence of the mannitol polymorphic form shifted from β-mannitol to δ-mannitol with increasing protein concentration in freeze-dried formulations. In spray-dried formulations an increase in protein concentration resulted in a shift from β-mannitol to α-mannitol. An increase in final drying temperature of the freeze-drying process towards the temperature of the spray-drying process did not lead to significant changes. It can thus be concluded that it is the drying process in itself, rather than the temperature, that leads to the observed solid state changes. Copyright © 2013 Elsevier B.V. All rights reserved.

Resin impregnation process for producing a resin-fiber composite

NASA Technical Reports Server (NTRS)

Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

1994-01-01

Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

7 CFR 58.230 - Heavy duty vacuum cleaners.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Heavy duty vacuum cleaners. 58.230 Section 58.230 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....230 Heavy duty vacuum cleaners. Each plant handling dry milk products shall be equipped with a heavy...

Double-Vacuum-Bag Process for Making Resin-Matrix Composites

NASA Technical Reports Server (NTRS)

Bradford, Larry J.

2007-01-01

A double-vacuum-bag process has been devised as a superior alternative to a single-vacuum-bag process used heretofore in making laminated fiber-reinforced resin-matrix composite-material structural components. This process is applicable to broad classes of high-performance matrix resins including polyimides and phenolics that emit volatile compounds (solvents and volatile by-products of resin-curing chemical reactions) during processing. The superiority of the double-vacuum-bag process lies in enhanced management of the volatile compounds. Proper management of volatiles is necessary for making composite-material components of high quality: if not removed and otherwise properly managed, volatiles can accumulate in interior pockets as resins cure, thereby forming undesired voids in the finished products. The curing cycle for manufacturing a composite laminate containing a reactive resin matrix usually consists of a two-step ramp-and-hold temperature profile and an associated single-step pressure profile as shown in Figure 1. The lower-temperature ramp-and-hold step is known in the art as the B stage. During the B stage, prepregs are heated and volatiles are generated. Because pressure is not applied at this stage, volatiles are free to escape. Pressure is applied during the higher-temperature ramp-and-hold step to consolidate the laminate and impart desired physical properties to the resin matrix. The residual volatile content and fluidity of the resin at the beginning of application of consolidation pressure are determined by the temperature and time parameters of the B stage. Once the consolidation pressure is applied, residual volatiles are locked in. In order to produce a void-free, high-quality laminate, it is necessary to design the curing cycle to obtain the required residual fluidity and the required temperature at the time of application of the consolidation pressure.

Finite-element simulation of ceramic drying processes

NASA Astrophysics Data System (ADS)

Keum, Y. T.; Jeong, J. H.; Auh, K. H.

2000-07-01

A finite-element simulation for the drying process of ceramics is performed. The heat and moisture movements in green ceramics caused by the temperature gradient, moisture gradient, conduction, convection and evaporation are considered. The finite-element formulation for solving the temperature and moisture distributions, which not only change the volume but also induce the hygro-thermal stress, is carried out. Employing the internally discontinuous interface elements, the numerical divergence problem arising from sudden changes in heat capacity in the phase zone is solved. In order to verify the reliability of the formulation, the drying process of a coal and the wetting process of a graphite epoxy are simulated and the results are compared with the analytical solution and another investigator's result. Finally, the drying process of a ceramic electric insulator is simulated.

Recent developments in drying of food products

NASA Astrophysics Data System (ADS)

Valarmathi, T. N.; Sekar, S.; Purushothaman, M.; Sekar, S. D.; Rama Sharath Reddy, Maddela; Reddy, Kancham Reddy Naveen Kumar

2017-05-01

Drying is a dehydration process to preserve agricultural products for long period usage. The most common and cheapest method is open sun drying in which the products are simply laid on ground, road, mats, roof, etc. But the open sun drying has some disadvantages like dependent on good weather, contamination by dust, birds and animals consume a considerable quantity, slow drying rate and damages due to strong winds and rain. To overcome these difficulties solar dryers are developed with closed environment for drying agricultural products effectively. To obtain good quality food with reduced energy consumption, selection of appropriate drying process and proper input parameters is essential. In recent years several researchers across the world have developed new drying systems for improving the product quality, increasing the drying rate, decreasing the energy consumption, etc. Some of the new systems are fluidized bed, vibrated fluidized bed, desiccant, microwave, vacuum, freeze, infrared, intermittent, electro hydrodynamic and hybrid dryers. In this review the most recent progress in the field of drying of agricultural food products such as new methods, new products and modeling and optimization techniques has been presented. Challenges and future directions are also highlighted. The review will be useful for new researchers entering into this ever needed and ever growing field of engineering.

Chemical composition, antioxidant capacity, and sensory quality of dried jujube fruits as affected by cultivar and drying method.

PubMed

Wojdyło, Aneta; Figiel, Adam; Legua, Pilar; Lech, Krzysztof; Carbonell-Barrachina, Ángel A; Hernández, Francisca

2016-09-15

The aim of this study was to determine the effect of different dying methods, such as convective drying (CD: 50, 60, 70 °C), vacuum-microwave drying (VMD: 120, 480, 480-120 W), a combination of convective pre-drying and vacuum-microwave finish drying [(CPD (60 °C)-VMFD (480-120 W)], and freeze-drying (FD) on key quality parameters of dried jujube fruits (cv. "GAL", "MSI", and "PSI"). The parameters studied included bioactive compounds (flavan-3-ols and flavonols, identified by LC-PDA-MS, and vitamin C), antioxidant capacity (ABTS and FRAP), and sensory attributes (e.g. hardness, jujube-ID, and sweetness). The best quality of the dried product (high contents of bioactive compounds and high intensity of key sensory attributes) was found in fruits treated by FD and VMD 480-120 W. The best cultivars were "PSI" and "GAL" from the point of view of bioactive content and sensory quality, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quality factors, antioxidant activity, and sensory properties of jet-tube dried rabbiteye blueberries.

PubMed

Pallas, Laura A; Pegg, Ronald B; Kerr, William L

2013-06-01

Rabbiteye blueberries are an excellent source of nutrients and phytochemicals. They are often dried, which can degrade health-promoting compounds. Means of shortening exposure to high-temperature drying air are desirable. Five cultivars of rabbiteye blueberries ('Premier', 'Tifblue', 'Brightwell', 'Alapaha', and 'Powderblue') were dried in a jet-tube fluidized bed air dryer with varying pretreatments including mechanical abrasion and osmotic dehydration. Drying time ranged from 66 to 95 min at 107 °C, achieving a final water activity of 0.347-0.605. Prior osmotic dehydration significantly reduced the drying time. Vacuum osmotic dehydration for 70 min achieved similar moisture contents to soaking blueberries for 24 h. Jet-tube dried blueberries exhibited greater color saturation than commercially available blueberries. While drying reduced the total monomeric anthocyanin (TMA) content, this occurred to a lesser extent than by other processing methods. The total phenolics content (TPC) and antioxidant capacity (H-ORACFL values) increased after drying. 'Premier' was the most preferred vacuum-infused dried blueberry, with a water activity (aw) of 0.53 and 157 g H2O kg(-1). 'Tifblue' was most preferred amongst the overnight-infused and also unsweetened dried blueberries. Jet-tube drying can substantially reduce drying times while yielding blueberries with good color, sensory properties, TMA, TPC, and H-ORACFL values. Furthermore, some cultivars produce better-quality dried blueberries than others. © 2012 Society of Chemical Industry.

Germanium detector vacuum encapsulation

NASA Technical Reports Server (NTRS)

Madden, N. W.; Malone, D. F.; Pehl, R. H.; Cork, C. P.; Luke, P. N.; Landis, D. A.; Pollard, M. J.

1991-01-01

This paper describes an encapsulation technology that should significantly improve the viability of germanium gamma-ray detectors for a number of important applications. A specialized vacuum chamber has been constructed in which the detector and the encapsulating module are processed in high vacuum. Very high vacuum conductance is achieved within the valveless encapsulating module. The detector module is then sealed without breaking the chamber vacuum. The details of the vacuum chamber, valveless module, processing, and sealing method are presented.

Using vacuum pyrolysis and mechanical processing for recycling waste printed circuit boards.

PubMed

Long, Laishou; Sun, Shuiyu; Zhong, Sheng; Dai, Wencan; Liu, Jingyong; Song, Weifeng

2010-05-15

The constant growth in generation of waste printed circuit boards (WPCB) poses a huge disposal problem because they consist of a heterogeneous mixture of organic and metallic chemicals as well as glass fiber. Also the presence of heavy metals, such as Pb and Cd turns this scrap into hazardous waste. Therefore, recycling of WPCB is an important subject not only from the recovery of valuable materials but also from the treatment of waste. The aim of this study was to present a recycling process without negative impact to the environment as an alternative for recycling WPCB. In this work, a process technology containing vacuum pyrolysis and mechanical processing was employed to recycle WPCB. At the first stage of this work, the WPCB was pyrolyzed under vacuum in a self-made batch pilot-scale fixed bed reactor to recycle organic resins contained in the WPCB. By vacuum pyrolysis the organic matter was decomposed to gases and liquids which could be used as fuels or chemical material resources, however, the inorganic WPCB matter was left unaltered as solid residues. At the second stage, the residues obtained at the first stage were investigated to separate and recover the copper through mechanical processing such as crushing, screening, and gravity separation. The copper grade of 99.50% with recovery of 99.86% based on the whole WPCB was obtained. And the glass fiber could be obtained by calcinations in a muffle furnace at 600 degrees C for 10 min. This study had demonstrated the feasibility of vacuum pyrolysis and mechanical processing for recycling WPCB. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Effects of pulsed electric fields pretreatment and drying method on drying characteristics and nutritive quality of blueberries

USDA-ARS?s Scientific Manuscript database

Fresh blueberries were pretreated with pulsed electric fields (PEF) at 2 kV/cm and then dried at 45, 60 and 75 degrees C by conventional hot air or vacuum drying. Drying characteristics and changes in contents of moisture, anthocyanin, total phenolics, vitamin C, and antioxidant activity in the blu...

High Vacuum Creep Facility in the Materials Processing Laboratory

NASA Image and Video Library

1973-01-21

Technicians at work in the Materials Processing Laboratory’s Creep Facility at the National Aeronautics and Space Administration (NASA) Lewis Research Center. The technicians supported the engineers’ studies of refractory materials, metals, and advanced superalloys. The Materials Processing Laboratory contained laboratories and test areas equipped to prepare and develop these metals and materials. The ultra-high vacuum lab, seen in this photograph, contained creep and tensile test equipment. Creep testing is used to study a material’s ability to withstand long durations under constant pressure and temperatures. The equipment measured the strain over a long period of time. Tensile test equipment subjects the test material to strain until the material fails. The two tests were used to determine the strength and durability of different materials. The Materials Processing Laboratory also housed arc and electron beam melting furnaces, a hydraulic vertical extrusion press, compaction and forging equipment, and rolling mills and swagers. There were cryogenic and gas storage facilities and mechanical and oil diffusion vacuum pumps. The facility contained both instrumental and analytical chemistry laboratories for work on radioactive or toxic materials and the only shop to machine toxic materials in the Midwest.

Design of freeze-drying processes for pharmaceuticals: practical advice.

PubMed

Tang, Xiaolin; Pikal, Michael J

2004-02-01

Design of freeze-drying processes is often approached with a "trial and error" experimental plan or, worse yet, the protocol used in the first laboratory run is adopted without further attempts at optimization. Consequently, commercial freeze-drying processes are often neither robust nor efficient. It is our thesis that design of an "optimized" freeze-drying process is not particularly difficult for most products, as long as some simple rules based on well-accepted scientific principles are followed. It is the purpose of this review to discuss the scientific foundations of the freeze-drying process design and then to consolidate these principles into a set of guidelines for rational process design and optimization. General advice is given concerning common stability issues with proteins, but unusual and difficult stability issues are beyond the scope of this review. Control of ice nucleation and crystallization during the freezing step is discussed, and the impact of freezing on the rest of the process and final product quality is reviewed. Representative freezing protocols are presented. The significance of the collapse temperature and the thermal transition, denoted Tg', are discussed, and procedures for the selection of the "target product temperature" for primary drying are presented. Furthermore, guidelines are given for selection of the optimal shelf temperature and chamber pressure settings required to achieve the target product temperature without thermal and/or mass transfer overload of the freeze dryer. Finally, guidelines and "rules" for optimization of secondary drying and representative secondary drying protocols are presented.

Drying-induced physico-chemical changes in cranberry products.

PubMed

Michalska, Anna; Wojdyło, Aneta; Honke, Joanna; Ciska, Ewa; Andlauer, Wilfried

2018-02-01

Sugar-free cranberry juice (XAD) and juice with 15% of maltodextrin were dried by freeze-, vacuum and spray drying methods. Total phenolics (589-6435mg/kg dry matter) including 5 flavonols, 3 phenolic acids, 2 procyanidins and 5 anthocyanins were stronger affected by juice formulation than by drying methods. Spray drying of juice, regardless of its formulation, was competitive to freeze drying in terms of polyphenols' retention. Increase in temperature up to 100°C during vacuum drying of XAD extracts resulted in degradation of polyphenolics (down to 4%), except chlorogenic acid. Its content increased with rise in temperature and accelerated hydroxymethylfurfural formation. The stronger the impact of drying, the more chlorogenic acid is present in cranberry products. In all powders analysed, formation of furoylmethyl amino acids was noted. Antioxidant capacity of cranberry products was influenced by juice formulation and was linked to content of polyphenols. Copyright © 2017 Elsevier Ltd. All rights reserved.

Study of Performance of Coaxial Vacuum Tube Solar Collector on Ethanol Distillation Process

NASA Astrophysics Data System (ADS)

Sutomo; Ramelan, A. H.; Mustafa; Tristono, T.

2017-07-01

Coaxial vacuum tube solar collectors can generate heat up to 80°C is possibly used for ethanol distillation process that required temperature 79°C only. This study reviews the performance of coaxial collector vacuum tube used for ethanol distillation process. This experimental research was conducted in a closed space using a halogen lamp as a solar radiation simulator. We had done on three different of the radiation values, i.e. 998 W/m2, 878 W/m2 and 782 W/m2. The pressure levels of vacuum tube collector cavity in the research were 1; 0.5; 0.31; 0.179; and 0.043 atmospheres. The Research upgraded the 30% of ethanol to produce the concentration of 77% after distillation. The result shows that the performance of coaxial collector vacuum tube used for ethanol distillation process has the negative correlation to the level of the collector tube cavity pressure. The productivity will increase while the collector tube cavity pressure decreased. Therefore, the collector efficiency has the negative correlation also to the level of collector tube cavity pressure. The best performance achieved when it operated at a pressure of 0.043 atmosphere with radiation intensity 878 W / m2, and the value of efficiency is 57.8%.

Scalable organic solvent free supercritical fluid spray drying process for producing dry protein formulations.

PubMed

Nuchuchua, O; Every, H A; Hofland, G W; Jiskoot, W

2014-11-01

In this study, we evaluated the influence of supercritical carbon dioxide (scCO2) spray drying conditions, in the absence of organic solvent, on the ability to produce dry protein/trehalose formulations at 1:10 and 1:4 (w/w) ratios. When using a 4L drying vessel, we found that decreasing the solution flow rate and solution volume, or increasing the scCO2 flow rate resulted in a significant reduction in the residual water content in dried products (Karl Fischer titration). The best conditions were then used to evaluate the ability to scale the scCO2 spray drying process from 4L to 10L chamber. The ratio of scCO2 and solution flow rate was kept constant. The products on both scales exhibited similar residual moisture contents, particle morphologies (SEM), and glass transition temperatures (DSC). After reconstitution, the lysozyme activity (enzymatic assay) and structure (circular dichroism, HP-SEC) were fully preserved, but the sub-visible particle content was slightly increased (flow imaging microscopy, nanoparticle tracking analysis). Furthermore, the drying condition was applicable to other proteins resulting in products of similar quality as the lysozyme formulations. In conclusion, we established scCO2 spray drying processing conditions for protein formulations without an organic solvent that holds promise for the industrial production of dry protein formulations. Copyright © 2014 Elsevier B.V. All rights reserved.

Drying effects on the antioxidant properties of tomatoes and ginger.

PubMed

Gümüşay, Özlem Aktürk; Borazan, Alev Akpınar; Ercal, Nuran; Demirkol, Omca

2015-04-15

In this study, the effects of four different drying processes, sun drying (SD), oven drying (OD), vacuum oven drying (VOD) and freeze drying (FD) for tomatoes (Solanum lycopersicum) and ginger (Zingiber officinale) in terms of thiolic and phenolic contents have been studied. Thiol content, total phenolic content (TPC), ascorbic acid (AA) content, and cupric ion reducing antioxidant capacity (CUPRAC) were determined in fresh and dried samples. Glutathione (GSH) and cysteine (Cys) were determined as the thiol contents of tomatoes and ginger. Significant losses were observed in the contents of TPC, AA, GSH and Cys and CUPRAC values in all samples that were dried using the thermal method. There was a statistically significant difference in the losses of the TPC, AA, and thiol contents between the use of thermal drying and freeze drying (except Cys in tomatoes) methods. Freeze dried tomato and ginger samples have been found to have better antioxidant properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

Vacuum Processing Technique for Development of Primary Standard Blackbodies

PubMed Central

Navarro, M.; Bruce, S. S.; Johnson, B. Carol; Murthy, A. V.; Saunders, R. D.

1999-01-01

Blackbody sources with nearly unity emittance that are in equilibrium with a pure freezing metal such as gold, silver, or copper are used as primary standard sources in the International Temperature Scale of 1990 (ITS-90). Recently, a facility using radio-frequency induction heating for melting and filling the blackbody crucible with the freeze metal under vacuum conditions was developed at the National Institute of Standards and Technology (NIST). The blackbody development under a vacuum environment eliminated the possibility of contamination of the freeze metal during the process. The induction heating, compared to a resistively heated convection oven, provided faster heating of crucible and resulted in shorter turn-around time of about 7 h to manufacture a blackbody. This paper describes the new facility and its application to the development of fixed-point blackbodies.

Metabolomics method based on ultra high performance liquid chromatography with time-of-flight mass spectrometry to analyze toxins in fresh and dried toad venom.

PubMed

Ma, Hongyue; Niu, Huixia; Cao, Qin; Zhou, Jing; Gong, Yan; Zhu, Zhenhua; Lv, Xiang; Di, Liuqing; Qian, Dawei; Wu, Qinan; Duan, Jin'ao

2016-12-01

Drying is a critical step to prolong the storage time in natural medicine processing but it changes the chemical characteristics of the product. In this study, research was performed to characterize the metabolomic changes in toad venom induced by vacuum-drying at 60°C and air-drying at room temperature by ultra high performance liquid chromatography coupled with pattern recognition approaches. In total 52 metabolites, down-regulated or up-regulated, were identified as potential chemical markers. Compared with fresh toad venom, vacuum-drying at 60°C succeeded in raising the conjugated-type bufadienolide content significantly, while the content of free-type bufadienolides were slightly reduced. On the other hand, toad venom air-dried at room temperature presented a relatively low amount of bufadienolides compared with fresh venom. For example, the content of several known anti-tumor components (gamabufotalin, bufotalin, cinobufagin, etc.) were significantly reduced. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide bioassay further showed that venom air-dried at room temperature had weaker anti-tumor activity on human hepatocellular carcinoma SMMC-7721 proliferation in vitro than samples vacuum-dried at 60°C. These results showed that the great metabolomic changes of toad venom occurred during the drying process, suggesting that a proper drying procedure is important for sustaining the chemical quality of natural medicines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling of electrohydrodynamic drying process using response surface methodology

PubMed Central

Dalvand, Mohammad Jafar; Mohtasebi, Seyed Saeid; Rafiee, Shahin

2014-01-01

Energy consumption index is one of the most important criteria for judging about new, and emerging drying technologies. One of such novel and promising alternative of drying process is called electrohydrodynamic (EHD) drying. In this work, a solar energy was used to maintain required energy of EHD drying process. Moreover, response surface methodology (RSM) was used to build a predictive model in order to investigate the combined effects of independent variables such as applied voltage, field strength, number of discharge electrode (needle), and air velocity on moisture ratio, energy efficiency, and energy consumption as responses of EHD drying process. Three-levels and four-factor Box–Behnken design was employed to evaluate the effects of independent variables on system responses. A stepwise approach was followed to build up a model that can map the entire response surface. The interior relationships between parameters were well defined by RSM. PMID:24936289

Freeze-drying of yeast cultures.

PubMed

Bond, Chris

2007-01-01

A method is described that allows yeast species to be stored using a variation on the standard freeze-drying method, which employs evaporative cooling in a two-stage process. Yeast cultures are placed in glass ampoules after having been mixed with a lyoprotectant. Primary drying is carried out using a centrifuge head connected to a standard freeze-dryer. Once the centrifuge head is running, air is removed and evaporated liquid is captured in the freeze-dryer. Centrifugation continues for 15 min and primary drying for a further 3 h. The ampoules are constricted using a glass blowing torch. They are then placed on the freeze-dryer manifold for secondary drying under vacuum overnight, using phosphorus pentoxide as a desiccant. The ampoules are sealed and removed from the manifold by melting the constricted section. Although the process causes an initial large drop in viability, further losses after storage are minimal. Yeast strains have remained viable for more than 30 yr when stored using this method and sufficient cells are recovered to produce new working stocks. Although survival rates are strain specific, nearly all National Collection of Yeast Cultures strains covering most yeast genera, have been successfully stored with little or no detectable change in strain characteristics.

Exergetic simulation of a combined infrared-convective drying process

NASA Astrophysics Data System (ADS)

Aghbashlo, Mortaza

2016-04-01

Optimal design and performance of a combined infrared-convective drying system with respect to the energy issue is extremely put through the application of advanced engineering analyses. This article proposes a theoretical approach for exergy analysis of the combined infrared-convective drying process using a simple heat and mass transfer model. The applicability of the developed model to actual drying processes was proved using an illustrative example for a typical food.

Experimental research of solid waste drying in the process of thermal processing

NASA Astrophysics Data System (ADS)

Bukhmirov, V. V.; Kolibaba, O. B.; Gabitov, R. N.

2015-10-01

The convective drying process of municipal solid waste layer as a polydispersed multicomponent porous structure is studied. On the base of the experimental data criterial equations for calculating heat transfer and mass transfer processes in the layer, depending on the humidity of the material, the speed of the drying agent and the layer height are obtained. These solutions are used in the thermal design of reactors for the thermal processing of multicomponent organic waste.

Emerging freeze-drying process development and scale-up issues.

PubMed

Patel, Sajal Manubhai; Pikal, Michael J

2011-03-01

Although several guidelines do exist for freeze-drying process development and scale-up, there are still a number of issues that require additional attention. The objective of this review article is to discuss some emerging process development and scale-up issue with emphasis on effect of load condition and freeze-drying in novel container systems such as syringes, Lyoguard trays, ampoules, and 96-well plates. Understanding the heat and mass transfer under different load conditions and for freeze-drying in these novel container systems will help in developing a robust freeze-drying process which is also easier to scale-up. Further research and development needs in these emerging areas have also been addressed. © 2011 American Association of Pharmaceutical Scientists

Description of saturation curves and boiling process of dry air

NASA Astrophysics Data System (ADS)

Vestfálová, Magda; Petříková, Markéta; Šimko, Martin

2018-06-01

Air is a mixture of gases forming the gas wrap of Earth. It is formed by dry air, moisture and other pollutants. Dry air is a substance whose thermodynamic properties in gaseous state, as well as the thermodynamic properties of its main constituents in gaseous state, are generally known and described in detail in the literature. The liquid air is a bluish liquid and is industrially used to produce oxygen, nitrogen, argon and helium by distillation. The transition between the gaseous and liquid state (the condensation process, resp. boiling process), is usually displayed in the basic thermodynamic diagrams using the saturation curves. The saturation curves of all pure substances are of a similar shape. However, since the dry air is a mixture, the shapes of its saturation curves are modified relative to the shapes corresponding to the pure substances. This paper deals with the description of the dry air saturation curves as a mixture, i.e. with a description of the process of phase change of dry air (boiling process). The dry air saturation curves are constructed in the basic thermodynamic charts based on the values obtained from the literature. On the basis of diagrams, data appearing in various publications are interpreted and put into context with boiling process of dry air.

Press Dry Conference 1983 Held at Madison, Wisconsin on September 7-9, 1983,

DTIC Science & Technology

1983-01-01

facil- model has served as a useful tool to ities wherein one can witness the pros verify reported results of other and cons associated with emerging...subjects of reduces the surface temperature required to pro - research at the Institute. The concepts being duce rapid drying; the desirability of operating...kraft handsheets (1650 experimental investigation of a new, thermally- g/m2 basis weight) at a 452 initial moisture con - driven, vacuum drying process

Effect of drying method to antioxidants capacity of Limnophila aromatica

NASA Astrophysics Data System (ADS)

Yen, Tran Thi Ngoc; Vu, Nguyen Hoang

2017-09-01

Limnophila aromatica is widely used in South East Asian countries to make spices in food and medicine in traditional medicine. The use value of vegetables is known because some of the lesser constituents in plants are called antioxidants. These active ingredients have not been fully researched and their pharmacological effects are underestimated. In this study, the drying temperature at 40 °C was showed that the antioxidant activity decreased the most. The drying temperature of 50 °C is suitable for convection drying method and drying temperature of 60 °C suitable for vacuum drying, as it retains the most antioxidant properties. Regarding the drying method, freeze drying proved to be effective when retaining high antioxidant capacity. Using The convection drying at 50 °C and the vacuum drying at 60 °C, the antioxidant activity of Limnophila aromatica was not different. Over 6 weeks of preservation, the dried product has deterioration in antioxidant properties.

Advanced Drying Process for Lower Manufacturing Cost of Electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmad, Iftikhar; Zhang, Pu

For this Vehicle Technologies Incubator/Energy Storage R&D topic, Lambda Technologies teamed with Navitas Systems and proposed a new advanced drying process that promised a 5X reduction in electrode drying time and significant reduction in the cost of large format lithium batteries used in PEV's. The operating principle of the proposed process was to use penetrating radiant energy source Variable Frequency Microwaves (VFM), that are selectively absorbed by the polar water or solvent molecules instantly in the entire volume of the electrode. The solvent molecules are thus driven out of the electrode thickness making the process more efficient and much fastermore » than convective drying method. To evaluate the Advanced Drying Process (ADP) a hybrid prototype system utilizing VFM and hot air flow was designed and fabricated. While VFM drives the solvent out of the electrode thickness, the hot air flow exhausts the solvent vapors out of the chamber. The drying results from this prototype were very encouraging. For water based anodes there is a 5X drying advantage (time & length of oven) in using ADP over standard drying system and for the NMP based cathodes the reduction in drying time has 3X benefit. For energy savings the power consumption measurements were performed to ADP prototype and compared with the convection standard drying oven. The data collected demonstrated over 40% saving in power consumption with ADP as compared to the convection drying systems. The energy savings are one of the operational cost benefits possible with ADP. To further speed up the drying process, the ADP prototype was explored as a booster module before the convection oven and for the electrode material being evaluated it was possible to increase the drying speed by a factor of 4, which could not be accomplished with the standard dryer without surface defects and cracks. The instantaneous penetration of microwave in the entire slurry thickness showed a major advantage in rapid drying

Enhancement of water removing and the quality of fried purple-fleshed sweet potato in the vacuum frying by combined power ultrasound and microwave technology.

PubMed

Su, Ya; Zhang, Min; Bhandari, Bhesh; Zhang, Weiming

2018-06-01

The combination of ultrasound and microwave in vacuum frying system was investigated to achieve higher drying efficiency and quality attributes of fried products. Purple-fleshed potato were used as test specimen and different power levels of microwave (0 W, 600 W, 800 W) and ultrasound (0 W, 300 W, 600 W) during vacuum frying. Drying kinetics, dielectric properties, moisture state variation and quality attributes of fried samples were measured in a vacuum frying (VF), and an innovatively designed ultrasound and microwave assisted vacuum frying (USMVF) equipment. The USMVF process markedly increased the moisture evaporation rate and effective moisture diffusivity compared to VF process. The oil uptake was reduced by about 16-34%, the water activity and the shrinkage was lowered, the texture (crispness) and the color of fried samples were greatly improved. The higher ultrasound and microwave power level in USMVF made a greater improvement. The total anthocyanin levels and retention of fried purple-fleshed potato chips was the highest (123.52 mg/100 g solids and 79.51% retention, respectively) among all treatments in US600M800VF process. The SEM analysis revealed a more porous and disruption microstructure in USMVF sample. Copyright © 2018 Elsevier B.V. All rights reserved.

Overview Of Dry-Etch Techniques

NASA Astrophysics Data System (ADS)

Salzer, John M.

1986-08-01

With pattern dimensions shrinking, dry methods of etching providing controllable degrees of anisotropy become a necessity. A number of different configurations of equipment - inline, hex, planar, barrel - have been offered, and within each type, there are numerous significant variations. Further, each specific type of machine must be perfected over a complex, interactive parameter space to achieve suitable removal of various materials. Among the most critical system parameters are the choice of cathode or anode to hold the wafers, the chamber pressure, the plasma excitation frequency, and the electrode and magnetron structures. Recent trends include the use of vacuum load locks, multiple chambers, multiple electrodes, downstream etching or stripping, and multistep processes. A major percentage of etches in production handle the three materials: polysilicon, oxide and aluminum. Recent process developments have targeted refractory metals, their silicides, and with increasing emphasis, silicon trenching. Indeed, with new VLSI structures, silicon trenching has become the process of greatest interest. For stripping, dry processes provide advantages other than anisotropy. Here, too, new configurations and methods have been introduced recently. While wet processes are less than desirable from a number of viewpoints (handling, safety, disposal, venting, classes of clean room, automatability), dry methods are still being perfected as a direct, universal replacement. The paper will give an overview of these machine structures and process solutions, together with examples of interest. These findings and the trends discussed are based on semiannual survey of manufacturers and users of the various types of equipment.

Effects of Freeze-Dried Vegetable Products on the Technological Process and the Quality of Dry Fermented Sausages.

PubMed

Eisinaite, Viktorija; Vinauskiene, Rimante; Viskelis, Pranas; Leskauskaite, Daiva

2016-09-01

The aim of this study was to compare the chemical composition of freeze-dried vegetable powders: celery, celery juice, parsnip and leek. The effect of different freeze-dried vegetables onto the ripening process and the properties of dry fermented sausages was also evaluated. Vegetable products significantly (p < 0.05) differed in their chemical composition: celery products contained higher amounts of nitrates, total phenolic compounds and lower amounts of sucrose, parsnip had higher concentration of proteins, leek was rich in fat. The analysis of pH, water activity, lactic acid bacteria, coagulase-positive staphylococci and coliforms content showed that the incorporation of freeze-dried vegetables had no negative effect on the fermentation and ripening process of dry fermented sausages. In addition, the color parameters for sausages with the added lyophilised celery products were considerable (p < 0.05) more stable during these processes. At the end of the ripening process the sausages made with lyophilised celery juice were characterised by higher lightness and lower hardness than those made with the addition of other vegetable products and control. Freeze-dried celery, celery juice, parsnip and leek have some potential for the usage as a functional ingredient or as a source for indirect addition of nitrate in the production of fermented sausages. © 2016 Institute of Food Technologists®

9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Drying, blending, packaging, and heat..., blending, packaging, and heat treatment rooms and facilities. (a) General. Processing rooms shall be... vacuum cleaned daily. (c) The heat treatment room shall be of an approved construction and be maintained...

9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Drying, blending, packaging, and heat..., blending, packaging, and heat treatment rooms and facilities. (a) General. Processing rooms shall be... vacuum cleaned daily. (c) The heat treatment room shall be of an approved construction and be maintained...

9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Drying, blending, packaging, and heat..., blending, packaging, and heat treatment rooms and facilities. (a) General. Processing rooms shall be... vacuum cleaned daily. (c) The heat treatment room shall be of an approved construction and be maintained...

9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Drying, blending, packaging, and heat..., blending, packaging, and heat treatment rooms and facilities. (a) General. Processing rooms shall be... vacuum cleaned daily. (c) The heat treatment room shall be of an approved construction and be maintained...

Implementation of a process analytical technology system in a freeze-drying process using Raman spectroscopy for in-line process monitoring.

PubMed

De Beer, T R M; Allesø, M; Goethals, F; Coppens, A; Heyden, Y Vander; De Diego, H Lopez; Rantanen, J; Verpoort, F; Vervaet, C; Remon, J P; Baeyens, W R G

2007-11-01

The aim of the present study was to propose a strategy for the implementation of a Process Analytical Technology system in freeze-drying processes. Mannitol solutions, some of them supplied with NaCl, were used as models to freeze-dry. Noninvasive and in-line Raman measurements were continuously performed during lyophilization of the solutions to monitor real time the mannitol solid state, the end points of the different process steps (freezing, primary drying, secondary drying), and physical phenomena occurring during the process. At-line near-infrared (NIR) and X-ray powder diffractometry (XRPD) measurements were done to confirm the Raman conclusions and to find out additional information. The collected spectra during the processes were analyzed using principal component analysis and multivariate curve resolution. A two-level full factorial design was used to study the significant influence of process (freezing rate) and formulation variables (concentration of mannitol, concentration of NaCl, volume of freeze-dried sample) upon freeze-drying. Raman spectroscopy was able to monitor (i) the mannitol solid state (amorphous, alpha, beta, delta, and hemihydrate), (ii) several process step end points (end of mannitol crystallization during freezing, primary drying), and (iii) physical phenomena occurring during freeze-drying (onset of ice nucleation, onset of mannitol crystallization during the freezing step, onset of ice sublimation). NIR proved to be a more sensitive tool to monitor sublimation than Raman spectroscopy, while XRPD helped to unravel the mannitol hemihydrate in the samples. The experimental design results showed that several process and formulation variables significantly influence different aspects of lyophilization and that both are interrelated. Raman spectroscopy (in-line) and NIR spectroscopy and XRPD (at-line) not only allowed the real-time monitoring of mannitol freeze-drying processes but also helped (in combination with experimental design) us

Effect of drying methods on the structure, thermo and functional properties of fenugreek (Trigonella foenum graecum) protein isolate.

PubMed

Feyzi, Samira; Varidi, Mehdi; Zare, Fatemeh; Varidi, Mohammad Javad

2018-03-01

Different drying methods due to protein denaturation could alter the functional properties of proteins, as well as their structure. So, this study focused on the effect of different drying methods on amino acid content, thermo and functional properties, and protein structure of fenugreek protein isolate. Freeze and spray drying methods resulted in comparable protein solubility, dynamic surface and interfacial tensions, foaming and emulsifying properties except for emulsion stability. Vacuum oven drying promoted emulsion stability, surface hydrophobicity and viscosity of fenugreek protein isolate at the expanse of its protein solubility. Vacuum oven process caused a higher level of Maillard reaction followed by the spray drying process, which was confirmed by the lower amount of lysine content and less lightness, also more browning intensity. ΔH of fenugreek protein isolates was higher than soy protein isolate, which confirmed the presence of more ordered structures. Also, the bands which are attributed to the α-helix structures in the FTIR spectrum were in the shorter wave number region for freeze and spray dried fenugreek protein isolates that show more possibility of such structures. This research suggests that any drying method must be conducted in its gentle state in order to sustain native structure of proteins and promote their functionalities. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

High post-thaw survival of ram sperm after partial freeze-drying.

PubMed

Arav, Amir; Idda, Antonella; Nieddu, Stefano Mario; Natan, Yehudit; Ledda, Sergio

2018-03-14

Recrystallization damages occur when a frozen sample is held at high subzero temperatures and when the warming process is too slow. In this work, ram semen diluted in two different concentrations of sugar solutions (Lyo A consisted of 0.4 M sorbitol and 0.25 M trehalose, and the second, Lyo B composed of 0.26 M sorbitol and 0.165 M trehalose) in egg yolk and Tris medium were compared after freezing 10 μL samples to: (1) - 10, - 25, and - 35 °C and thawing. (2) Freezing to - 10 and - 25 °C, holding for 1 h and then thawing, and (3) freezing to - 10 and - 25 °C and drying for 1 h at these temperatures at a vacuum of 80 mTorr, prior thawing. For drying, we used a new freeze-drying apparatus (Darya, FertileSafe, Israel) having a condensation temperature below - 110 °C and a vacuum pressure of 10-100 mTorr that is reached in less than 10s. Results showed that samples in Lyo B solution frozen at - 25 °C had significantly higher sperm motility in partially freeze-dried samples than frozen samples (46.6 ± 2.8% vs 1.2 ± 2.5%, P < 0.001). Moreover, partially dried samples in Lyo B showed higher motility than Lyo A at - 25 °C (46.6 ± 2.8% vs 35 ± 4%). Cryomicroscopy and low-temperature/low-pressure environmental scanning electronic microscope demonstrated that the amount of the ice crystals present in partially dried samples was lower than in the frozen samples. Holding the sperm at high subzero temperatures is necessary for the primary drying of cells during the freeze-drying process. Rapid freeze-drying can be achieved using this new device, which enables to reduce recrystallization damages.

Radiation processing as a post-harvest quarantine control for raisins, dried figs and dried apricots

NASA Astrophysics Data System (ADS)

Cetinkaya, N.; Ozyardımci, B.; Denli, E.; Ic, E.

2006-03-01

The commercially packed samples of raisins, dried figs and dried apricots were irradiated using doses in the range of 0.5-1.0 kGy for disinfestation and 0.5-5.0 kGy for sensory analysis with the dose rate ranging from 1.44 to 1.92 kGy/h. Pests on dried fruits were evaluated after 0, 1, 2 and 3 months of storage for irradiated dried figs and 1, 3, 6 and 12 months of storage for raisins and dried apricots. Sensory analysis of dried figs, dried apricots and raisins were carried out after 0, 1, 3, 6 and 12 months of storage. The results indicated that radiation processing at low doses, (˜1.0 kGy) is an effective post-harvest treatment and quarantine control for these products with no adverse effects on sensory (marketing) attributes.

Volatile composition and sensory profile of shiitake mushrooms as affected by drying method.

PubMed

Politowicz, Joanna; Lech, Krzysztof; Lipan, Leontina; Figiel, Adam; Carbonell-Barrachina, Ángel A

2018-03-01

One of the best preservation method for long-term storage is drying. In this work, the influence of different drying methods on aroma and sensory profile of shiitake mushroom was evaluated. The drying methods tested were: convective drying (CD), freeze-drying (FD), vacuum-microwave drying (VMD), and a combination of convective pre-drying and vacuum-microwave finish-drying (CPD-VMFD). The volatile composition of fresh and dried shiitake mushrooms was analysed by SPME, GC-MS and GC-FID, and showed the presence of 71 volatile compounds, most of them present in all dried samples but with quantitative variation. The major volatile compounds in fresh shiitake were 1-octen-3-ol (20.2%), 2-octanone (20.7%), 1,2,4-trithiolane (9.8%), and 1,2,3,5,6-pentathiepane (8.2%). Drying of shiitake mushrooms caused significant losses of C8 compounds and cyclic sulfur compounds, such as 1,2,4-trithiolane (V31) and 1,2,4,5-tetrathiane (V57). Samples dried at CD 80 °C implied a relative short drying time (120 min), had the highest contents of total volatiles (1594 μg 100 g -1 ) and cyclic sulfur compounds (e.g. V57 126 μg 100 g -1 ), and the highest intensity of most of the key positive sensory attributes, such as inner colour (7.0), fresh shiitake flavour (6.7), and sponginess (6.2). The best dehydration methods, resulting in the highest total concentrations of volatile compounds and high intensity of key sensory attributes were FD (if vacuum and liquid nitrogen facilities are available) and CD at 80 °C (for companies with vacuum and liquid nitrogen facilities). © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Robot design for a vacuum environment

NASA Technical Reports Server (NTRS)

Belinski, S.; Trento, W.; Imani-Shikhabadi, R.; Hackwood, S.

1987-01-01

The cleanliness requirements for many processing and manufacturing tasks are becoming ever stricter, resulting in a greater interest in the vacuum environment. Researchers discuss the importance of this special environment, and the development of robots which are physically and functionally suited to vacuum processing tasks. Work is in progress at the Center for robotic Systems in Microelectronics (CRSM) to provide a robot for the manufacture of a revolutionary new gyroscope in high vacuum. The need for vacuum in this and other processes is discussed as well as the requirements for a vacuum-compatible robot. Finally, researchers present details on work done at the CRSM to modify an existing clean-room compatible robot for use at high vacuum.

Stepwise drying of medicinal plants as alternative to reduce time and energy processing

NASA Astrophysics Data System (ADS)

Cuervo-Andrade, S. P.; Hensel, O.

2016-07-01

The objective of drying medicinal plants is to extend the shelf life and conserving the fresh characteristics. This is achieved by reducing the water activity (aw) of the product to a value which will inhibit the growth and development of pathogenic and spoilage microorganisms, significantly reducing enzyme activity and the rate at which undesirable chemical reactions occur. The technical drying process requires an enormous amount of thermal and electrical energy. An improvement in the quality of the product to be dried and at the same time a decrease in the drying cost and time are achieved through the utilization of a controlled conventional drying method, which is based on a good utilization of the renewable energy or looking for other alternatives which achieve lower processing times without sacrificing the final product quality. In this work the method of stepwise drying of medicinal plants is presented as an alternative to the conventional drying that uses a constant temperature during the whole process. The objective of stepwise drying is the decrease of drying time and reduction in energy consumption. In this process, apart from observing the effects on decreases the effective drying process time and energy, the influence of the different combinations of drying phases on several characteristics of the product are considered. The tests were carried out with Melissa officinalis L. variety citronella, sowed in greenhouse. For the stepwise drying process different combinations of initial and final temperature, 40/50°C, are evaluated, with different transition points associated to different moisture contents (20, 30, 40% and 50%) of the product during the process. Final quality of dried foods is another important issue in food drying. Drying process has effect in quality attributes drying products. This study was determining the color changes and essential oil loses by reference the measurement of the color and essential oil content of the fresh product was

The physico-chemical basis for the freeze-drying process.

PubMed

MacKenzie, A P

1976-10-01

To the extent that the final form and quality of a freeze-dried product depends on the way the freeze-drying is conducted, an understanding of the many factors involved is most important. The numerous effects of the design and mode of operation of the freeze-drying equipment on the course of the process need to be known, as do the properties intrinsic to the material to be freeze-dried. Much can be learned and predicted from the study of the "supplemented phase diagram", a series of experimental plots describing the equilibrium and the non-equilibrium phase behavior of the system in question. Such diagrams map and distinguish eutectic and amorphous phase behavior. Further information is available from gravimetric studies allowing the construction of "desorption isotherms", the plots describing the loss of sorbed water accompanying the sublimation of ice, frequently termed "secondary drying". These plots relate the water retained by the product to the "water activity", or relative humidity at different temperatures. Observations in the freeze-drying microscope contribute additional information, in that they reveal the actual course of the process at the microscopic level. These and other laboratory findings facilitate the analysis and comparison of pilot-plant and commercical scale processing experiences. Where scientific and engineering factors appear to interrelate, the nature and extent of the interdependence can often be determined.

Effect of vacuum processing on outgassing within an orbiting molecular shield

NASA Technical Reports Server (NTRS)

Outlaw, R. A.

1982-01-01

The limiting hydrogen number density in an orbiting molecular shield is highly dependent on the outgassing rates from the materials of construction for the shield, experimental apparatus, and other hardware contained within the shield. Ordinary degassing temperatures used for ultrahigh vacuum studies (less than 450 C) are not sufficient to process metals so that the contribution to the number density within the shield due to outgassing is less than the theoretically attainable level (approximately 200 per cu. cm). Pure aluminum and type 347 stainless steel were studied as candidate shield materials. Measurements of their hydrogen concentration and diffusion coefficients were made, and the effects of high temperature vacuum processing (greater than 600 C) on their resulting outgassing rates was determined. The densities in a molecular shield due to the outgassing from either metal were substantially less ( 0.003) than the density due to the ambient atomic hydrogen flux at an orbital altitude of 500 km.

Mechanical properties and production quality of hand-layup and vacuum infusion processed hybrid composite materials for GFRP marine structures

NASA Astrophysics Data System (ADS)

Kim, Sang-Young; Shim, Chun Sik; Sturtevant, Caleb; Kim, Dave (Dae-Wook); Song, Ha Cheol

2014-09-01

Glass Fiber Reinforced Plastic (GFRP) structures are primarily manufactured using hand lay-up or vacuum infusion techniques, which are cost-effective for the construction of marine vessels. This paper aims to investigate the mechanical properties and failure mechanisms of the hybrid GFRP composites, formed by applying the hand lay-up processed exterior and the vacuum infusion processed interior layups, providing benefits for structural performance and ease of manufacturing. The hybrid GFRP composites contain one, two, and three vacuum infusion processed layer sets with consistent sets of hand lay-up processed layers. Mechanical properties assessed in this study include tensile, compressive and in-plane shear properties. Hybrid composites with three sets of vacuum infusion layers showed the highest tensile mechanical properties while those with two sets had the highest mechanical properties in compression. The batch homogeneity, for the GFRP fabrication processes, is evaluated using the experimentally obtained mechanical properties

MEASUREMENT OF INDOOR AIR EMISSIONS FROM DRY-PROCESS PHOTOCOPY MACHINES

EPA Science Inventory

The article provides background information on indoor air emissions from office equipment, with emphasis on dry-process photocopy machines. The test method is described in detail along with results of a study to evaluate the test method using four dry-process photocopy machines. ...

Freeze-drying process monitoring using a cold plasma ionization device.

PubMed

Mayeresse, Y; Veillon, R; Sibille, P H; Nomine, C

2007-01-01

A cold plasma ionization device has been designed to monitor freeze-drying processes in situ by monitoring lyophilization chamber moisture content. This plasma device, which consists of a probe that can be mounted directly on the lyophilization chamber, depends upon the ionization of nitrogen and water molecules using a radiofrequency generator and spectrometric signal collection. The study performed on this probe shows that it is steam sterilizable, simple to integrate, reproducible, and sensitive. The limitations include suitable positioning in the lyophilization chamber, calibration, and signal integration. Sensitivity was evaluated in relation to the quantity of vials and the probe positioning, and correlation with existing methods, such as microbalance, was established. These tests verified signal reproducibility through three freeze-drying cycles. Scaling-up studies demonstrated a similar product signature for the same product using pilot-scale and larger-scale equipment. On an industrial scale, the method efficiently monitored the freeze-drying cycle, but in a larger industrial freeze-dryer the signal was slightly modified. This was mainly due to the positioning of the plasma device, in relation to the vapor flow pathway, which is not necessarily homogeneous within the freeze-drying chamber. The plasma tool is a relevant method for monitoring freeze-drying processes and may in the future allow the verification of current thermodynamic freeze-drying models. This plasma technique may ultimately represent a process analytical technology (PAT) approach for the freeze-drying process.

Three stage vacuum system for ultralow temperature installation

NASA Astrophysics Data System (ADS)

Das, N. K.; Pradhan, J.; Naser, Md Z. A.; Mandal, B. Ch; Roy, A.; Kumar, P.; Mallik, C.; Bhandari, R. K.

2012-11-01

We use a three stage vacuum system for developing a dilution fridge at VECC, Kolkata. We aim at achieving a cooling power of 20μW at 100mK for various experiments especially in the field of condensed matter and nuclear physics. The system is essentially composed of four segments-bath cryostat, vacuum system, dilution insert and 3He circulation circuit. Requirement of vacuum system at different stages are different. The vacuum system for cryostat and for internal vacuum chamber located within the helium bath is a common turbo molecular pump backed by scroll pump as to maintain a vacuum ~10-6mbar. For bringing down the temperature of the helium evaporator, we use a high throughput Roots pump backed by a dry pump. The pumping system for 3He distillation chamber (still) requires a high pumping speed, so a turbo drag pump backed by a scroll pump has been installed. As the fridge use precious 3He gas for operation, the entire system has been made to be absolutely leak proof with respect to the 3He gas.

Numerical Simulation of the Working Process in the Twin Screw Vacuum Pump

NASA Astrophysics Data System (ADS)

Lu, Yang; Fu, Yu; Guo, Bei; Fu, Lijuan; Zhang, Qingqing; Chen, Xiaole

2017-08-01

Twin screw vacuum pumps inherit the advantages of screw machinery, such as high reliability, stable medium conveying, small vibration, simple and compact structures, convenient operation, etc, which have been widely used in petrochemical and air industry. On the basis of previous studies, this study analyzed the geometric features of variable pitch of the twin screw vacuum pump such as the sealing line, the meshing line and the volume between teeth. The mathematical model of numerical simulation of the twin screw vacuum pump was established. The leakage paths of the working volume including the sealing line and the addendum arc were comprehensively considered. The corresponding simplified geometric model of leakage flow was built up for different leak paths and the flow coefficients were calculated. The flow coefficient value range of different leak paths was given. The results showed that the flow coefficient of different leak paths can be taken as constant value for the studied geometry. The analysis of recorded indicator diagrams showed that the increasing rotational speed can dramatically decrease the exhaust pressure and the lower rotational speed can lead to over-compression. The pressure of the isentropic process which was affected by leakage was higher than the theoretical process.

Spray-drying nanocapsules in presence of colloidal silica as drying auxiliary agent: formulation and process variables optimization using experimental designs.

PubMed

Tewa-Tagne, Patrice; Degobert, Ghania; Briançon, Stéphanie; Bordes, Claire; Gauvrit, Jean-Yves; Lanteri, Pierre; Fessi, Hatem

2007-04-01

Spray-drying process was used for the development of dried polymeric nanocapsules. The purpose of this research was to investigate the effects of formulation and process variables on the resulting powder characteristics in order to optimize them. Experimental designs were used in order to estimate the influence of formulation parameters (nanocapsules and silica concentrations) and process variables (inlet temperature, spray-flow air, feed flow rate and drying air flow rate) on spray-dried nanocapsules when using silica as drying auxiliary agent. The interactions among the formulation parameters and process variables were also studied. Responses analyzed for computing these effects and interactions were outlet temperature, moisture content, operation yield, particles size, and particulate density. Additional qualitative responses (particles morphology, powder behavior) were also considered. Nanocapsules and silica concentrations were the main factors influencing the yield, particulate density and particle size. In addition, they were concerned for the only significant interactions occurring among two different variables. None of the studied variables had major effect on the moisture content while the interaction between nanocapsules and silica in the feed was of first interest and determinant for both the qualitative and quantitative responses. The particles morphology depended on the feed formulation but was unaffected by the process conditions. This study demonstrated that drying nanocapsules using silica as auxiliary agent by spray drying process enables the obtaining of dried micronic particle size. The optimization of the process and the formulation variables resulted in a considerable improvement of product yield while minimizing the moisture content.

Vacuum storage of yellow-poplar pollen

Treesearch

James R. Wilcox

1966-01-01

Vacuum-drying, followed by storage in vacuo or in an inert gas, is effective for storing pollen of many species. It permits storage at room environments without rigid controls of either temperature or humidity, an advantage that becomes paramount during long-distance transfers of pollen when critical storage conditions are impossible to maintain. In...

Application of high pressure processing to reduce verotoxigenic E. coli in two types of dry-fermented sausage.

PubMed

Omer, M K; Alvseike, O; Holck, A; Axelsson, L; Prieto, M; Skjerve, E; Heir, E

2010-12-01

The effect of high pressure processing (HPP) on the survival of verotoxigenic Escherichia coli (VTEC) in two types of Norwegian type dry-fermented sausages was studied. Two different types of recipes for each sausage type were produced. The sausage batter was inoculated with 6.8 log(10) CFU/g of VTEC O103:H25. After fermentation, drying and maturation, slices of finished sausages were vacuum packed and subjected to two treatment regimes of HPP. One group was treated at 600 MPa for 10 min and another at three cycles of 600 MPa for 200 s per cycle. A generalized linear model split by recipe type showed that these two HPP treatments on standard recipe sausages reduced E. coli by 2.9 log(10) CFU/g and 3.3 log(10) CFU/g, respectively. In the recipe with higher levels of dextrose, sodium chloride and sodium nitrite E. coli reduction was 2.7 log(10) CFU/g in both treatments. The data show that HPP has a potential to make the sausages safer and also that the effect depends somewhat on recipe. Copyright © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

A model for the effect of real leaks on the transport of microorganisms into a vacuum freeze-dryer.

PubMed

Jennings, T A

1990-01-01

This paper proposes a model for determining the effect that real leaks, whose flow is viscous in nature, could have on the microorganism density in a vacuum freeze-dryer during a drying process. The model considers the entry of microorganisms to result from real leaks stemming from an environment containing a known bioburden. A means for determining the relationship between the rate of pressure rise of the system (ROR) and the density of microorganisms in a system, stemming from an environment of a known bioburden, is examined. The model also considers the change in the bioburden of the dryer with respect to variations in the primary and secondary drying process.

Effect of drying, storage temperature and air exposure on astaxanthin stability from Haematococcus pluvialis.

PubMed

Ahmed, Faruq; Li, Yan; Fanning, Kent; Netzel, Michael; Schenk, Peer M

2015-08-01

Astaxanthin is a powerful antioxidant with various health benefits such as prevention of age-related macular degeneration and improvement of the immune system, liver and heart function. To improve the post-harvesting stability of astaxanthin used in food, feed and nutraceutical industries, the biomass of the high astaxanthin producing alga Haematococcus pluvialis was dried by spray- or freeze-drying and under vacuum or air at -20°C to 37°C for 20weeks. Freeze-drying led to 41% higher astaxanthin recovery compared to commonly-used spray-drying. Low storage temperature (-20°C, 4°C) and vacuum-packing also showed higher astaxanthin stability with as little as 12.3±3.1% degradation during 20weeks of storage. Cost-benefit analysis showed that freeze-drying followed by vacuum-packed storage at -20°C can generate AUD$600 higher profit compared to spray-drying from 100kgH. pluvialis powder. Therefore, freeze-drying can be suggested as a mild and more profitable method for ensuring longer shelf life of astaxanthin from H. pluvialis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Materials processing in space, 1980 science planning document. [crystal growth, containerless processing, solidification, bioprocessing, and ultrahigh vacuum processes

NASA Technical Reports Server (NTRS)

Naumann, R. J.

1980-01-01

The scientific aspects of the Materials Processing in Space program are described with emphasis on the major categories of interest: (1) crystal growth; (2) solidification of metals, alloys, and composites; (3) fluids and chemical processes; (4) containerless processing, glasses, and refractories; (5) ultrahigh vacuum processes; and (6) bioprocessing. An index is provided for each of these areas. The possible contributions that materials science experiments in space can make to the various disciplines are summarized, and the necessity for performing experiments in space is justified. What has been learned from previous experiments relating to space processing, current investigations, and remaining issues that require resolution are discussed. Recommendations for the future direction of the program are included.

Manufacturing Solid Dosage Forms from Bulk Liquids Using the Fluid-bed Drying Technology.

PubMed

Qi, Jianping; Lu, Y I; Wu, Wei

2015-01-01

Solid dosage forms are better than liquid dosage forms in many ways, such as improved physical and chemical stability, ease of storage and transportation, improved handling properties, and patient compliance. Therefore, it is required to transform dosage forms of liquid origins into solid dosage forms. The functional approaches are to absorb the liquids by solid excipients or through drying. The conventional drying technologies for this purpose include drying by heating, vacuum-, freeze- and spray-drying, etc. Among these drying technologies, fluidbed drying emerges as a new technology that possesses unique advantages. Fluid-bed drying or coating is highly efficient in solvent removal, can be performed at relatively low temperatures, and is a one-step process to manufacture formulations in pellet forms. In this article, the status of the art of manufacturing solid dosage forms from bulk liquids by fluid-bed drying technology was reviewed emphasizing on its application in solid dispersion, inclusion complexes, self-microemulsifying systems, and various nanoscale drug delivery systems.

Tribochemical Competition within a MoS2/Ti Dry Lubricated Macroscale Contact in Ultrahigh Vacuum: A Time-of-Flight Secondary Ion Mass Spectrometry Investigation.

PubMed

Colas, Guillaume; Saulot, Aurélien; Philippon, David; Berthier, Yves; Léonard, Didier

2018-06-13

Controlling and predicting the tribological behavior of dry lubricants is a necessity to ensure low friction, long life, and low particle generation. Understanding the tribochemistry of the materials as a function of the environment is of primary interest as synergistic effects exist between the mechanics, the physicochemistry, and the thermodynamics within a contact. However, in most studies the role of the coating internal contaminants in the process is often discarded to the benefit of a more common approach in which the performances of the materials are compared as a function of different atmospheric pressure environments. The study focuses on the understanding of the tribochemical processes occurring between the materials and their internal contaminants inside an AISI440C contact lubricated by a MoS 2 /Ti coating. Time-of-flight secondary ion mass spectrometry is used to study at the molecular level, the material before and after friction. Friction tests with different durations are performed in ultrahigh vacuum at the macroscale to stay relevant to the real application (space). The adsorption/desorption of gaseous species during friction is monitored by mass spectrometry to ensure reliable study of the tribochemical processes inside the contact. The study shows that a competition exists between the Ti- and MoS 2 -based materials to create the appropriate lubricating materials via (i) recrystallization of MoS 2 materials with creation of a MoS x O y material via reactions with internal contaminants (presumably H 2 O), (ii) reaction of Ti-based materials with internal contaminants (mostly H 2 O and N 2 ). The biphasic material created is highly similar to the one created in both humid air and dry N 2 environments and providing low friction and low particle generation. However, the process is incomplete. The study thus brings insight into the possibility of controlling friction via a rational inclusion of reactants in a form of contaminants to control the

A NEW, SMALL DRYING FACILITY FOR WET RADIOACTIVE WASTE AND LIQUIDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oldiges, Olaf; Blenski, Hans-Juergen

2003-02-27

Due to the reason, that in Germany every Waste, that is foreseen to be stored in a final disposal facility or in a long time interim storage facility, it is necessary to treat a lot of waste using different drying technologies. In Germany two different drying facilities are in operation. The GNS Company prefers a vacuum-drying-technology and has built and designed PETRA-Drying-Facilities. In a lot of smaller locations, it is not possible to install such a facility because inside the working areas of that location, the available space to install the PETRA-Drying-Facility is too small. For that reason, GNS decidedmore » to design a new, small Drying-Facility using industrial standard components, applying the vacuum-drying-technology. The new, small Drying-Facility for wet radioactive waste and liquids is presented in this paper. The results of some tests with a prototype facility are shown in chapter 4. The main components of that new facility are described in chapter 3.« less

Combined wet and dry cleaning of SiGe(001)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Sang Wook; Kaufman-Osborn, Tobin; Kim, Hyonwoong

Combined wet and dry cleaning via hydrofluoric acid (HF) and atomic hydrogen on Si{sub 0.6}Ge{sub 0.4}(001) surface was studied at the atomic level using ultrahigh vacuum scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and x-ray photoelectron spectroscopy to understand the chemical transformations of the surface. Aqueous HF removes native oxide, but residual carbon and oxygen are still observed on Si{sub 0.6}Ge{sub 0.4}(001) due to hydrocarbon contamination from post HF exposure to ambient. The oxygen contamination can be eliminated by shielding the sample from ambient via covering the sample in the HF cleaning solution until the sample is introduced tomore » the vacuum chamber or by transferring the sample in an inert environment; however, both processes still leave carbon contaminant. Dry in-situ atomic hydrogen cleaning above 330 °C removes the carbon contamination on the surface consistent with a thermally activated atomic hydrogen reaction with surface hydrocarbon. A postdeposition anneal at 550 °C induces formation of an atomically flat and ordered SiGe surface observed by STM. STS verifies that the wet and dry cleaned surface has an unpinned Fermi level with no states between the conduction and valence band edge comparable to sputter cleaned SiGe surfaces.« less

Influence of the Ultrasonic Power Applied on Freeze Drying Kinetics

NASA Astrophysics Data System (ADS)

Brines, C.; Mulet, A.; García-Pérez, J. V.; Riera, E.; Cárcel, J. A.

The atmospheric freeze drying (AFD) constitutes an interesting alternative to vacuum freeze drying providing products with similar quality at lowest cost. However, the long process time needed represent an important drawback. In this sense, the application of high intensity ultrasound can enhance heat and mass transfer and intensify the operation. In hot air drying operation, the ultrasonic effects are dependent on the process variables such as air velocity, internal sample structure or ultrasonic power applied. However, in AFD processes, the internal structure of material or the air velocity has not significant influence on the magnitude of ultrasonic effects. The aim of this work was to determine the influence on drying kinetics of the ultrasonic power applied during the AFD of apple. For that purpose, AFD experiments (-10 °C, 2 m/s and 15% relative humidity) of apple slabs (cv. Granny Smith, 30 x 30 x 10 mm) were carried out with ultrasound application (21 kHz) at different power levels (0, 10.3, 20.5 and 30.8 kW/m3). The drying kinetics was obtained from the initial moisture content and the weight evolution of samples during drying. Experimental results showed a significant (p<0.05) influence of the ultrasound application on drying. Thus, drying time was shorter as higher the ultrasonic power applied. From modeling, it was observed that the effective diffusion coefficient identified was 4.8 times higher when ultrasound was applied at the lowest power tested (10.3 kW/m3) that illustrated the high intensification potential of ultrasound application in the AFD.

Effect of mesh-peel ply variation on mechanical properties of E-glas composite by infusion vacuum method

NASA Astrophysics Data System (ADS)

Abdurohman, K.; Siahaan, Mabe

2018-04-01

Composite materials made of glass fiber EW-135 with epoxy lycal resin with vacuum infusion method have been performed. The dried glass fiber is arranged in a mold then connected to a vacuum machine and a resin tube. Then, the vacuum machine is turned on and at the same time the resin is sucked and flowed into the mold. This paper reports on the effect of using mesh- peel ply singles on upper-side laminates called A and the effect of using double mesh-peel ply on upper and lower-side laminates call B with glass fiber arrangement is normal and ± 450 in vacuum infusion process. Followed by the manufacture of tensile test specimen and tested its tensile strength with universal test machine 100kN Tensilon RTF 2410, at room temperature with constant crosshead speed. From tensile test results using single and double layers showed that double mesh-peel ply can increase tensile strength 14% and Young modulus 17%.

Physics of direct-contact ultrasonic cloth drying process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Chang; Ravi, Saitej; Patel, Viral K.

Existing methods of drying fabrics involve energy-intensive thermal evaporation of moisture from clothes. Drying fabrics using high-frequency vibrations of piezoelectric transducers can substantially reduce drying time and energy consumption. In this method, vibrational energy generates instability on the liquid-air interface and mechanically ejects water from a wet fabric. For the first time, the physics of the ultrasonic fabric drying process in direct-contact mode is studied. The kinematic and thermal responses of water droplets and fabrics on piezoelectric crystal transducers and metal mesh–based transducers are studied. The results suggest that on piezoelectric crystal transducers, the response of a droplet subjected tomore » ultrasonic excitation is dictated by the relative magnitude of the surface tension and the ultrasonic excitation forces. The drying process for a fabric on the studied transducers consists of two regimes—vibrational and thermal. When the water content is high, the vibrational forces can eject bulk water rapidly. But the more strongly bound water within the smaller fabric pores evaporates by the thermal energy generated as a result of the viscous losses. Our study finds that a metal mesh–based transducer is more suitable for dewatering fabrics, as it facilitates the ejection of water from the fabric–transducer interface to the opposite side of the mesh. A demonstration unit developed consumes 10–20% of the water latent heat energy at water contents greater than 20%.« less

Physics of direct-contact ultrasonic cloth drying process

DOE PAGES

Peng, Chang; Ravi, Saitej; Patel, Viral K.; ...

2017-02-27

Existing methods of drying fabrics involve energy-intensive thermal evaporation of moisture from clothes. Drying fabrics using high-frequency vibrations of piezoelectric transducers can substantially reduce drying time and energy consumption. In this method, vibrational energy generates instability on the liquid-air interface and mechanically ejects water from a wet fabric. For the first time, the physics of the ultrasonic fabric drying process in direct-contact mode is studied. The kinematic and thermal responses of water droplets and fabrics on piezoelectric crystal transducers and metal mesh–based transducers are studied. The results suggest that on piezoelectric crystal transducers, the response of a droplet subjected tomore » ultrasonic excitation is dictated by the relative magnitude of the surface tension and the ultrasonic excitation forces. The drying process for a fabric on the studied transducers consists of two regimes—vibrational and thermal. When the water content is high, the vibrational forces can eject bulk water rapidly. But the more strongly bound water within the smaller fabric pores evaporates by the thermal energy generated as a result of the viscous losses. Our study finds that a metal mesh–based transducer is more suitable for dewatering fabrics, as it facilitates the ejection of water from the fabric–transducer interface to the opposite side of the mesh. A demonstration unit developed consumes 10–20% of the water latent heat energy at water contents greater than 20%.« less

Quality by Design approach to spray drying processing of crystalline nanosuspensions.

PubMed

Kumar, Sumit; Gokhale, Rajeev; Burgess, Diane J

2014-04-10

Quality by Design (QbD) principles were explored to understand spray drying process for the conversion of liquid nanosuspensions into solid nano-crystalline dry powders using indomethacin as a model drug. The effects of critical process variables: inlet temperature, flow and aspiration rates on critical quality attributes (CQAs): particle size, moisture content, percent yield and crystallinity were investigated employing a full factorial design. A central cubic design was employed to generate the response surface for particle size and percent yield. Multiple linear regression analysis and ANOVA were employed to identify and estimate the effect of critical parameters, establish their relationship with CQAs, create design space and model the spray drying process. Inlet temperature was identified as the only significant factor (p value <0.05) to affect dry powder particle size. Higher inlet temperatures caused drug surface melting and hence aggregation of the dried nano-crystalline powders. Aspiration and flow rates were identified as significant factors affecting yield (p value <0.05). Higher yields were obtained at higher aspiration and lower flow rates. All formulations had less than 3% (w/w) moisture content. Formulations dried at higher inlet temperatures had lower moisture compared to those dried at lower inlet temperatures. Published by Elsevier B.V.

Utilization of geothermal heat in tropical fruit-drying process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, B.H.; Lopez, L.P.; King, R.

1982-10-01

The power plant utilizes only the steam portion of the HGP-A well production. There are approximately 50,000 pounds per hour of 360/sup 0/F water produced (approximately 10 million Btu per hour) and the water is currently not used and is considered a waste. This tremendous resource could very well be used in applications such as food processing, food dehydration and other industrial processing that requires low-grade heat. One of the applications is examined, namely the drying of tropical fruits particularly the papaya. The papaya was chosen for the obvious reason that it is the biggest crop of all fruits producedmore » on the Big Island. A conceptual design of a pilot plant facility capable of processing 1000 pounds of raw papaya per day is included. This facility is designed to provide a geothermally heated dryer to dehydrate papayas or other tropical fruits available on an experimental basis to obtain data such as drying time, optimum drying temperature, etc.« less

Drying effects on the antioxidant properties of polysaccharides obtained from Agaricus blazei Murrill.

PubMed

Wu, Songhai; Li, Feng; Jia, Shaoyi; Ren, Haitao; Gong, Guili; Wang, Yanyan; Lv, Zesheng; Liu, Yong

2014-03-15

Three polysaccharides (ABMP-F, ABMP-V, ABMP-A) were obtained from Agaricus blazei Murrill via methods such as freeze drying, vacuum drying and air drying, respectively. Their chemical compositions were examined, and antioxidant activities were investigated on the basis of assay for hydroxyl radical, DPPH radical, ABTS free radical scavenging ability and assay for Fe(2+)-chelating ability. Results showed that the three ABMPs have different physicochemical and antioxidant properties. Compared with air drying and vacuum drying methods, freeze drying method resulted to ABMP with higher neutral sugar, polysaccharide yield, uronic acid content, and stronger antioxidant abilities of hydroxyl radical, DPPH radical, ABTS radical scavenging and Fe(2+)-chelating. As a result, Agaricus blazei Murrill polysaccharides are natural antioxidant and freeze drying method serves as a good choice for the preparation of such polysaccharides and should be used to produce antioxidants for food industry. Copyright © 2014. Published by Elsevier Ltd.

Carbon nanotube vacuum gauges with wide-dynamic range and processes thereof

NASA Technical Reports Server (NTRS)

Manohara, Harish (Inventor); Kaul, Anupama B. (Inventor)

2013-01-01

A miniature thermal conductivity gauge employs a carbon single-walled-nanotube. The gauge operates on the principle of thermal exchange between the voltage-biased nanotube and the surrounding gas at low levels of power and low temperatures to measure vacuum across a wide dynamic range. The gauge includes two terminals, a source of constant voltage to the terminals, a single-walled carbon nanotube between the terminals, a calibration of measured conductance of the nanotube to magnitudes of surrounding vacuum and a current meter in electrical communication with the source of constant voltage. Employment of the nanotube for measuring vacuum includes calibrating the electrical conductance of the nanotube to magnitudes of vacuum, exposing the nanotube to a vacuum, applying a constant voltage across the nanotube, measuring the electrical conductance of the nanotube in the vacuum with the constant voltage applied and converting the measured electrical conductance to the corresponding calibrated magnitude of vacuum using the calibration. The nanotube may be suspended to minimize heat dissipation through the substrate, increasing sensitivity at even tower pressures.

Encapsulation of lactase in Ca(II)-alginate beads: Effect of stabilizers and drying methods.

PubMed

Traffano-Schiffo, Maria Victoria; Castro-Giraldez, Marta; Fito, Pedro J; Santagapita, Patricio R

2017-10-01

The purpose of the present work was to analyze the effect of trehalose, arabic and guar gums on the preservation of β-galactosidase activity in freeze-dried and vacuum dried Ca(II)-alginate beads. Freezing process was also studied as a first step of freeze-drying. Trehalose was critical for β-galactosidase conservation, and guar gum as a second excipient showed the highest conservation effect (close to 95%). Systems with T g values ~40°C which were stables at ambient temperature were obtained, being trehalose the main responsible of the formation of an amorphous matrix. Vacuum dried beads showed smaller size (with Feret's diameter below 1.08±0.09mm), higher circularity (reaching 0.78±0.06) and large cracks in their surface than freeze-dried beads, which were more spongy and voluminous. Ice crystallization of the beads revealed that the crystallization of Ca(II)-alginate system follows the Avrami kinetics of nucleation and growth. Particularly, Ca(II)-alginate showed an Avrami index of 2.03±0.07, which means that crystal growing is bidimensional. Neither the addition of trehalose nor gums affected the dimension of the ice growing or its rate. These results open an opportunity in the development of new lactic products able to be consumed by lactose intolerance people. Copyright © 2017 Elsevier Ltd. All rights reserved.

Creatine and creatinine evolution during the processing of dry-cured ham.

PubMed

Mora, Leticia; Hernández-Cázares, Aleida S; Sentandreu, Miguel Angel; Toldrá, Fidel

2010-03-01

Dry-curing of ham involves many biochemical reactions that depend on the processing conditions. The aim of this study was to evaluate the effect of the dry-cured processing on the concentration of creatine, creatinine and the creatinine/creatine ratio. Dry-cured hams under study were salted using three different salt mixtures (100% NaCl; NaCl and KCl at 50% each; and 55% NaCl, 25% KCl, 15% CaCl(2) and 5% MgCl(2)) in order to observe its influence on creatinine formation but no significant differences were found between them at any time of processing. However, significant differences between different post-salting times (20, 50 and 80 days) and the ripened hams (7, 9 and 11 months of ripening) were observed. Results showed that creatine and creatinine remain stable once the ripening period is reached. These results were confirmed when analysing dry-cured ham samples submitted to extreme conditions of temperature and time (20, 30, 40 and 70 degrees C during 0, 20, 40 and 60 min) as well as commercial dry-cured hams with more than 12 months of processing. Copyright 2009 Elsevier Ltd. All rights reserved.

Mechanistic modelling of infrared mediated energy transfer during the primary drying step of a continuous freeze-drying process.

PubMed

Van Bockstal, Pieter-Jan; Mortier, Séverine Thérèse F C; De Meyer, Laurens; Corver, Jos; Vervaet, Chris; Nopens, Ingmar; De Beer, Thomas

2017-05-01

Conventional pharmaceutical freeze-drying is an inefficient and expensive batch-wise process, associated with several disadvantages leading to an uncontrolled end product variability. The proposed continuous alternative, based on spinning the vials during freezing and on optimal energy supply during drying, strongly increases process efficiency and improves product quality (uniformity). The heat transfer during continuous drying of the spin frozen vials is provided via non-contact infrared (IR) radiation. The energy transfer to the spin frozen vials should be optimised to maximise the drying efficiency while avoiding cake collapse. Therefore, a mechanistic model was developed which allows computing the optimal, dynamic IR heater temperature in function of the primary drying progress and which, hence, also allows predicting the primary drying endpoint based on the applied dynamic IR heater temperature. The model was validated by drying spin frozen vials containing the model formulation (3.9mL in 10R vials) according to the computed IR heater temperature profile. In total, 6 validation experiments were conducted. The primary drying endpoint was experimentally determined via in-line near-infrared (NIR) spectroscopy and compared with the endpoint predicted by the model (50min). The mean ratio of the experimental drying time to the predicted value was 0.91, indicating a good agreement between the model predictions and the experimental data. The end product had an elegant product appearance (visual inspection) and an acceptable residual moisture content (Karl Fischer). Copyright © 2017 Elsevier B.V. All rights reserved.

Matrix Characterization and Development for the Vacuum Assisted Resin Transfer Molding Process

NASA Technical Reports Server (NTRS)

Grimsley, B. W.; Hubert, P.; Hou, T. H.; Cano, R. J.; Loos, A. C.; Pipes, R. B.

2001-01-01

The curing kinetics and viscosity of an epoxy resin system, SI-ZG-5A, have been characterized for application in the vacuum assisted resin transfer molding (VARTM) process. Impregnation of a typical carbon fiber perform provided the test bed for the characterization. Process simulations were carried out using the process model, COMPRO, to examine heat transfer and curing kinetics for a fully impregnated panel, neglecting resin flow. The predicted viscosity profile and final degree of cure were found to be in good agreement with experimental observations.

Vacuum Brazing of Accelerator Components

NASA Astrophysics Data System (ADS)

Singh, Rajvir; Pant, K. K.; Lal, Shankar; Yadav, D. P.; Garg, S. R.; Raghuvanshi, V. K.; Mundra, G.

2012-11-01

Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

Salting by Vacuum Brine Impregnation in Nitrite-Free Lonza: Effect on Enterobacteriaceae.

PubMed

Serio, Annalisa; Chaves-López, Clemencia; Rossi, Chiara; Pittia, Paola; Rosa, Marco Dalla; Paparella, Antonello

2017-01-24

Lonza is a traditional Italian meat product made from whole pork muscles, which is typically cured by dry salting. In this work, we study the effects of vacuum brine impregnation (VBI) as an alternative salting method on the survival of Enterobacteriaceae, in presence and in absence of nitrites. In comparison with the traditional brining process, VBI contributed to reducing the Enterobacteriaceae population on product surface but induced contamination of the inner muscle tissues. Our results suggest that the species isolated became adapted to processing conditions, and salt tolerance was species- or strain-dependent. This result is of particular importance for future applications of VBI in lonza manufacturing.

Plates for vacuum thermal fusion

DOEpatents

Davidson, James C.; Balch, Joseph W.

2002-01-01

A process for effectively bonding arbitrary size or shape substrates. The process incorporates vacuum pull down techniques to ensure uniform surface contact during the bonding process. The essence of the process for bonding substrates, such as glass, plastic, or alloys, etc., which have a moderate melting point with a gradual softening point curve, involves the application of an active vacuum source to evacuate interstices between the substrates while at the same time providing a positive force to hold the parts to be bonded in contact. This enables increasing the temperature of the bonding process to ensure that the softening point has been reached and small void areas are filled and come in contact with the opposing substrate. The process is most effective where at least one of the two plates or substrates contain channels or grooves that can be used to apply vacuum between the plates or substrates during the thermal bonding cycle. Also, it is beneficial to provide a vacuum groove or channel near the perimeter of the plates or substrates to ensure bonding of the perimeter of the plates or substrates and reduce the unbonded regions inside the interior region of the plates or substrates.

Microfabricated triggered vacuum switch

DOEpatents

Roesler, Alexander W [Tijeras, NM; Schare, Joshua M [Albuquerque, NM; Bunch, Kyle [Albuquerque, NM

2010-05-11

A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

Solid Lubrication by Multiwalled Carbon Nanotubes in Air and in Vacuum for Space and Aeronautics Applications

NASA Technical Reports Server (NTRS)

Miyoshi, Kazuhisa; Street, Kenneth W., Jr.; Andraws, Rodney; Jacques, David; VanderWal, Randy L.; Sayir, Ali

2005-01-01

To evaluate recently developed aligned multiwalled carbon nanotubes (MWNTs) and dispersed MWNTs for solid lubrication applications, unidirectional sliding friction experiments were conducted with 440 C stainless steel balls and hemispherical alumina-yttria stabilized zirconia pins in sliding contact with the MWNTs deposited on quartz disks in air and in vacuum. The results indicate that MWNTs have superior solid lubrication friction properties and endurance lives in air and vacuum under dry conditions. The coefficient of friction of the dispersed MWNTs is close to 0.05 and 0.009 in air and in vacuum, respectively, showing good dry lubricating ability. The wear life of MWNTs exceeds 1 million passes in both air and vacuum showing good durability. In general, the low coefficient of friction can be attributed to the combination of the transferred, agglomerated patches of MWNTs on the counterpart ball or pin surfaces and the presence of tubular MWNTs at interfaces.

Process and formulation effects on solar thermal drum dried prune pomace

USDA-ARS?s Scientific Manuscript database

The processing of dried plums into prune juice and concentrate yields prune pomace as a coproduct; the pomace could potentially be utilized as a food ingredient but requires stabilization for long-term storage. Drum drying is one method that could be used to dry and stabilize prune pomace, and a dru...

Rehydration properties of hybrid method dried fruit enriched by natural components

NASA Astrophysics Data System (ADS)

Kowalska, Hanna; Marzec, Agata; Kowalska, Jolanta; Ciurzyńska, Agnieszka; Samborska, Kinga; Bialik, Michał; Lenart, Andrzej

2018-04-01

The aim of the study was to determine the impact of osmotic pre-dehydration and drying of fruit on the rehydration properties of dried fruit. Herein, the effect of fruit juice, applied as a natural enriching substance was very important. In addition, the properties of dried fruits obtained through combined air-drying and subsequent microwave-vacuum drying with `puffing' effect were similar to the freeze-dried fruits, but showed other rehydration properties. As raw material, frozen strawberry (Honeoye variety) and fresh apples (Idared variety) were used in the study. The apples and partially defrosted strawberries were prior dehydrated in solutions of sucrose and a mixture of sucrose with chokeberry juice concentrate at 50°C for 2 h. Next, the fruit samples were dried by one of two ways: air-drying (50°C, 5 h) and microwavevacuum drying for about 360 s; and freeze-drying (30°C, 63 Pa, 24 h). The rehydration was carried out in distilled water (20°C, 5 h). The osmotic pre-dehydration hindered fruit drying process. The impact of drying method became particularly evident while examining the kinetics of rehydration. During the rehydration of the pre-dehydrated dried fruit a slower hydration could be observed. Freeze-dried strawberries absorbed 2-3 times more water than those dried by the `puffing' effect.

Experimental Study of Heat Transfer Performance of Polysilicon Slurry Drying Process

NASA Astrophysics Data System (ADS)

Wang, Xiaojing; Ma, Dongyun; Liu, Yaqian; Wang, Zhimin; Yan, Yangyang; Li, Yuankui

2016-12-01

In recent years, the growth of the solar energy photovoltaic industry has greatly promoted the development of polysilicon. However, there has been little research into the slurry by-products of polysilicon production. In this paper the thermal performance of polysilicon slurry was studied in an industrial drying process with a twin-screw horizontal intermittent dryer. By dividing the drying process into several subunits, the parameters of each unit could be regarded as constant in that period. The time-dependent changes in parameters including temperature, specific heat and evaporation enthalpy were plotted. An equation for the change in the heat transfer coefficient over time was calculated based on heat transfer equations. The concept of a distribution coefficient was introduced to reflect the influence of stirring on the heat transfer area. The distribution coefficient ranged from 1.2 to 1.7 and was obtained with the fluid simulation software FLUENT, which simplified the calculation of heat transfer area during the drying process. These experimental data can be used to guide the study of polysilicon slurry drying and optimize the design of dryers for industrial processes.

Turboexpanders with dry gas seals and active magnetic bearings in hydrocarbon processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agahi, R.R.

1999-07-01

Since its first application in hydrocarbon processing in the early 1960s, turboexpander design has changed, evolved and improved tremendously. Today, hydrocarbon process designers use turboexpanders for almost all hydrocarbon liquid rejection and hydrocarbon dew point control for onshore and offshore installations. There are presently more than 3,000 turboexpanders operating in hydrocarbon gas processing plants worldwide. Due to the wide application of turboexpanders in hydrocarbon processing, the API-617 committee has assigned a task force to prepare an appendix to API-617 to cover design and manufacturing standards for turboexpanders. Dry gas seals (DGS) were cautiously introduced in the early 1980s for compressorsmore » used in hydrocarbon processing. It took almost a decade before dry gas seals found their application in turboexpanders. Dry gas seals were originally utilized to protect cryogenic hydrocarbon process gas from contamination by lubricating oil. Later on, dry gas seals were used to minimized hydrocarbon process gas leakage and also to provide an inert-gas-purged environment for both oil bearings and active magnetic bearings. The former eliminates the lubricating oil dilution problem and the latter made certification of active magnetic bearings by international certifying agencies possible. Active magnetic bearings (AMB), similar to dry gas seals, were originally introduced into hydrocarbon process gas compressors in the mid 1980s. The hydrocarbon processing industry waited half a decade to adopt this innovative technology for turboexpanders in the hydrocarbon process. The first turboexpander with active magnetic bearings was installed on an offshore platform in 1991. High reliability, low capital investment, low capital investment, low operating costs and more compact design have accelerated demand in recent years for turboexpanders with active magnetic bearings. In this paper, the author describes the technology of turboexpanders with dry gas

Quality of pomegranate pomace as affected by drying method.

PubMed

Cano-Lamadrid, Marina; Lech, Krzysztof; Calín-Sánchez, Ángel; Rosas-Burgos, Ema Carina; Figiel, Adam; Wojdyło, Aneta; Wasilewska, Malwina; Carbonell-Barrachina, Ángel A

2018-03-01

During the industrial manufacturing of pomegranate juice, large amounts of pomace are produced. The aim of this work was to find the effective method to dry pomegranate pomace to open new commercial applications for this co-product. The effects of three drying methods: (i) convective drying (CD) at 50, 60, and 70 °C; (ii) vacuum microwave drying (VMD) at 240, 360, and 480 W, and (iii) a combined method (CPD-VMFD); convective pre-drying (60 °C) followed by vacuum microwave finish drying (360 W), on drying kinetics and quality of PomP (pomegranate pomace obtained after preparing pomegranate juice by squeezing only arils) were evaluated. The shortest treatments were VMD at 240 and 360 W (52 and 33 min, respectively); besides, these treatments led to interesting values of the green-red coordinate, a *, (12.2 and 4.1, respectively), total phenolic content (4.0 and 4.1 mg eq gallic acid g -1  dry weight, respectively), and antioxidant activity (30.8 and 29.0 µmol g -1  dry weight, respectively). On the other hand, this study demonstrated that this co-product is a rich source of punicic acid (average value = 66.4%), being a good opportunity for the pharmaceutical and nutraceutical industries. Moreover, no significant changes in the fatty acid profile was observed as affected by the drying treatments, and no off-flavors were generated by any of the drying methods.

Analysis of problems with dry fermentation process for biogas production

NASA Astrophysics Data System (ADS)

Pilát, Peter; Patsch, Marek; Jandačka, Jozef

2012-04-01

The technology of dry anaerobic fermentation is still meeting with some scepticism, and therefore in most biogas plants are used wet fermentation technology. Fermentation process would be not complete without an optimal controlled condition: dry matter content, density, pH, and in particular the reaction temperature. If is distrust of dry fermentation eligible it was on the workplace of the Department of Power Engineering at University of Zilina built an experimental small-scale biogas station that allows analysis of optimal parameters of the dry anaerobic fermentation, in particular, however, affect the reaction temperature on yield and quality of biogas.

Solid and Liquid Waste Drying Bag

NASA Technical Reports Server (NTRS)

Litwiller, Eric (Inventor); Hogan, John A. (Inventor); Fisher, John W. (Inventor)

2009-01-01

Method and system for processing waste from human activities, including solids, liquids and vapors. A fluid-impermeable bag, lined with a liquid-impermeable but vapor-permeable membrane, defining an inner bag, is provided. A vacuum force is provided to extract vapors so that the waste is moved toward a selected region in the inner bag, extracted vapors, including the waste vapors and vaporized portions of the waste liquids are transported across the membrane, and most or all of the solids remain within the liner. Extracted vapors are filtered, and sanitized components thereof are isolated and optionally stored. The solids remaining within the liner are optionally dried and isolated for ultimate disposal.

Application and utilization of a space chamber for the drying and decontamination of books, documents and other materials

NASA Technical Reports Server (NTRS)

Koesterer, M. G.; Geating, J. A.

1975-01-01

Truckloads of materials such as rare books, papers, engineering drawings, blue prints, art work, leather objects such as shoes, and clothing were successfully dried, decontaminated and impregnated against future infestation by microorganisms in a large 12 x 24 foot vacuum chamber designed originally for testing unmanned spacecraft. The process is unique in that it allows either frozen or wet material, soaked by some castastrophic event to be dried and sterilized in the same chamber with a minimum of handling and transportation.

Process-time Optimization of Vacuum Degassing Using a Genetic Alloy Design Approach

PubMed Central

Dilner, David; Lu, Qi; Mao, Huahai; Xu, Wei; van der Zwaag, Sybrand; Selleby, Malin

2014-01-01

This paper demonstrates the use of a new model consisting of a genetic algorithm in combination with thermodynamic calculations and analytical process models to minimize the processing time during a vacuum degassing treatment of liquid steel. The model sets multiple simultaneous targets for final S, N, O, Si and Al levels and uses the total slag mass, the slag composition, the steel composition and the start temperature as optimization variables. The predicted optimal conditions agree well with industrial practice. For those conditions leading to the shortest process time the target compositions for S, N and O are reached almost simultaneously. PMID:28788286

Resource recovery of organic sludge as refuse derived fuel by fry-drying process.

PubMed

Chang, Fang-Chih; Ko, Chun-Han; Wu, Jun-Yi; Wang, H Paul; Chen, Wei-Sheng

2013-08-01

The organic sludge and waste oil were collected from the industries of thin film transistor liquid crystal display and the recycled cooking oil. The mixing ratio of waste cooking oil and organic sludge, fry-drying temperatures, fry-drying time, and the characteristics of the organic sludge pellet grain were investigated. After the fry-drying process, the moisture content of the organic sludge pellet grain was lower than 5% within 25 min and waste cooking oil was absorbed on the dry solid. The fry-drying organic sludge pellet grain was easy to handle and odor free. Additionally, it had a higher calorific value than the derived fuel standards and could be processed into organic sludge derived fuels. Thus, the granulation and fry-drying processes of organic sludge with waste cooking oil not only improves the calorific value of organic sludge and becomes more valuable for energy recovery, but also achieves waste material disposal and cost reduction. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaporator fouling tendencies of thin stillage and concentrates from the dry grind process

USDA-ARS?s Scientific Manuscript database

In the US, more than 200 maize processing plants use multiple effect evaporators to remove water from thin stillage and steepwater during dry grind and wet milling processes, respectively. During the dry grind process, unfermentables are centrifuged and the liquid fraction, thin stillage, is concen...

Developing a vacuum thermal stripping - acid absorption process for ammonia recovery from anaerobic digester effluent.

PubMed

Ukwuani, Anayo T; Tao, Wendong

2016-12-01

To prevent acetoclastic methanogens from ammonia inhibition in anaerobic digestion of protein-rich substrates, ammonia needs to be removed or recovered from digestate. This paper presents an innovative ammonia recovery process that couples vacuum thermal stripping with acid absorption. Ammonia is stripped out of digestate boiling at a temperature below the normal boiling point due to vacuum. Stripped ammonia is absorbed to a sulfuric acid solution, forming ammonium sulfate crystals as a marketable product. Three common types of digestate were found to have boiling point temperature-vacuum curves similar to water. Seven combinations of boiling temperature and vacuum (50 °C 16.6 kPa, 58 °C 20.0 kPa, 65 °C 25.1 kPa, 70 °C 33.6 kPa, 80 °C 54.0 kPa, 90 °C 74.2 kPa, and 100 °C 101.3 kPa) were tested for batch stripping of ammonia in dairy manure digestate. 93.3-99.9% of ammonia was stripped in 3 h. The Lewis-Whitman model fitted ammonia stripping process well. Ammonia mass transfer coefficient was significantly higher at boiling temperature 65-100 °C and vacuum pressure 25.1-101.3 kPa than 50-58 °C and 16.6-20.0 kPa. The low ammonia saturation concentrations (0-24 mg N/L) suggested a large driving force to strip ammonia. The optimum boiling point temperature - vacuum pressure for ammonia recovery in a recirculation line of a mesophilic digester was 65 °C and 25.1 kPa, at which the ammonia mass transfer coefficient was as high as 37.3 mm/h. Installation of a demister and liquid trap could avoid negative effects of higher stripping temperature and stronger vacuum on formation of ammonium sulfate crystals. Pilot tests demonstrated that high-purity ammonium sulfate crystals could be produced by controlling sulfuric acid content and maintaining acid solution saturated with ammonium sulfate. Although volatile organic compounds such as cyclohexene were found in the final acid solutions, no volatile organic compounds were found in the recovered

A Plasma Window for Transmission of Radiation and Particle Beams from Vacuum to Atmosphere for Various Applications

NASA Astrophysics Data System (ADS)

Hershcovitch, Ady

1997-11-01

Many industrial and scientific processes like electron beam melting and welding, material modification by ion implantation, dry etching, and micro-fabrication, as well as generation of synchrotron radiation are performed almost exclusively in vacuum nowadays, since the electron and ion guns and their extractors must be kept at a reasonably high vacuum. Consequently, there are numerous drawbacks, among which are low production rates due to required pumping time, limits the vacuum volume sets on the size of target objects. In a small number of applications like non-vacuum electron beam welding, and various processes involving UV and x-ray radiation, thin vacuum walls or long stages of differential pumping are used. But, the resultant degradations of particle and radiation beams severely limit those applications. A novel apparatus, which utilized a short plasma arc, was successfully used to maintain a pressure of 7.6 x exp(-6) Torr in a vacuum chamber with a 2.36mm aperture to atmosphere, i.e., a plasma was successfully used to "plug" a hole to atmosphere while maintaining a reasonably high vacuum in the chamber. Successful transmission of charged particle beams from a vacuum through the plasma to atmosphere was accomplished. More details can be found in A. Hershcovitch, J. Appl. Physics 78, p. 5283 (1995). In addition to sustaining a vacuum atmosphere interface, the plasma has very strong lensing effect on charged particles. The plasma current generates an azimuthal magnetic field which exerts a radial Lorentz on charged particles moving parallel to the current channel. With proper orientation of the current direction, the Lorentz force is radially inward. This feature can be used to focus in beams to a very small spot size, and to overcome beam dispersion due to scattering by atmospheric atoms and molecules. Relatively hot plasma at the atmosphere boundary rarefies the atmospheric gases to further enhance particle beam propagation to the materials to target. Recent

Vacuum-bag-only processing of composites

NASA Astrophysics Data System (ADS)

Thomas, Shad

Ultrasonic imaging in the C-scan mode in conjunction with the amplitude of the reflected signal was used to measure flow rates of an epoxy resin film penetrating through the thickness of single layers of woven carbon fabric. Assemblies, comprised of a single layer of fabric and film, were vacuum-bagged and ultrasonically scanned in a water tank during impregnation at 50°C, 60°C, 70°C, and 80°C. Measured flow rates were plotted versus inverse viscosity to determine the permeability in the thin film, non-saturated system. The results demonstrated that ultrasonic imaging in the C-scan mode is an effective method of measuring z-direction resin flow through a single layer of fabric. The permeability values determined in this work were consistent with permeability values reported in the literature. Capillary flow was not observed at the temperatures and times required for pressurized flow to occur. The flow rate at 65°C was predicted from the linear plot of flow rate versus inverse viscosity. The effects of fabric architecture on through-thickness flow rates during impregnation of an epoxy resin film were measured by ultrasonic imaging. Multilayered laminates comprised of woven carbon fabrics and epoxy films (prepregs) were fabricated by vacuum-bagging. Ultrasonic imaging was performed in a heated water tank (65°C) during impregnation. Impregnation rates showed a strong dependence on fabric architecture, despite similar areal densities. Impregnation rates are directly affected by inter-tow spacing and tow nesting, which depend on fabric architecture, and are indirectly affected by areal densities. A new method of predicting resin infusion rates in prepreg and resin film infusion processes was proposed. The Stokes equation was used to derive an equation to predict the impregnation rate of laminates as a function of fabric architecture. Flow rate data previously measured by ultrasound was analyzed with the new equation and the Kozeny-Carman equation. A fiber

Stabilization of Live Attenuated Influenza Vaccines by Freeze Drying, Spray Drying, and Foam Drying.

PubMed

Lovalenti, Phillip M; Anderl, Jeff; Yee, Luisa; Nguyen, Van; Ghavami, Behnaz; Ohtake, Satoshi; Saxena, Atul; Voss, Thomas; Truong-Le, Vu

2016-05-01

The goal of this research is to develop stable formulations for live attenuated influenza vaccines (LAIV) by employing the drying methods freeze drying, spray drying, and foam drying. Formulated live attenuated Type-A H1N1 and B-strain influenza vaccines with a variety of excipient combinations were dried using one of the three drying methods. Process and storage stability at 4, 25 and 37°C of the LAIV in these formulations was monitored using a TCID50 potency assay. Their immunogenicity was also evaluated in a ferret model. The thermal stability of H1N1 vaccine was significantly enhanced through application of unique formulation combinations and drying processes. Foam dried formulations were as much as an order of magnitude more stable than either spray dried or freeze dried formulations, while exhibiting low process loss and full retention of immunogenicity. Based on long-term stability data, foam dried formulations exhibited a shelf life at 4, 25 and 37°C of >2, 1.5 years and 4.5 months, respectively. Foam dried LAIV Type-B manufactured using the same formulation and process parameters as H1N1 were imparted with a similar level of stability. Foam drying processing methods with appropriate selection of formulation components can produce an order of magnitude improvement in LAIV stability over other drying methods.

Vacuum casting of thick polymeric films

NASA Technical Reports Server (NTRS)

Cuddihy, E. F.; Moacanin, J.

1979-01-01

Bubble formation and layering, which often plague vacuum-evaporated films, are prevented by properly regulating process parameters. Vacuum casting may be applicable to forming thick films of other polymer/solvent solutions.

Influence of microwave vacuum drying on glass transition temperature, gelatinization temperature, physical and chemical qualities of lotus seeds.

PubMed

Zhao, Yingting; Jiang, Yajun; Zheng, Baodong; Zhuang, Weijing; Zheng, Yafeng; Tian, Yuting

2017-08-01

This study investigated the effects of microwave power density on effective moisture diffusion coefficient (D eff ), glass transition temperature (T g ), gelatinization temperature (T P ), physical and chemical qualities of lotus seeds during microwave vacuum drying. D eff increased by 42% and 127% at 15W/g and 20W/g, respectively, when compared with 10W/g. T P was negatively correlated with the relaxation times of T 21 and T 22 , while T g was negatively correlated with the relative areas A 22 . The rates of change of color were observed to be divided roughly into two periods, consisting of a rapid change caused by enzymatic browning and a slow change caused by non-enzymatic browning. An equation is provided to illustrate the relationship of k 1 and k 2 of Peleg's model depending on power density during rehydration kinetics. The samples at 20W/g exhibited the higher content of amino acid (540.19mg/100gd.b.) while lower starch (17.53g/100gd.b.). Copyright © 2017 Elsevier Ltd. All rights reserved.

Critically safe vacuum pickup for use in wet or dry cleanup of radioactive materials

DOEpatents

Zeren, Joseph D.

1994-01-01

A vacuum pickup of critically safe quantity and geometric shape is used in cleanup of radioactive materials. Collected radioactive material is accumulated in four vertical, parallel, equally spaced canisters arranged in a cylinder configuration. Each canister contains a filter bag. An upper intake manifold includes four 90 degree spaced, downward facing nipples. Each nipple communicates with the top of a canister. The bottom of each canister communicates with an exhaust manifold comprising four radially extending tubes that meet at the bottom of a centrally located vertical cylinder. The top of the central cylinder terminates at a motor/fan power head. A removable HEPA filter is located intermediate the top of the central cylinder and the power head. Four horizontal bypass tubes connect the top of the central cylinder to the top of each of the canisters. Air enters the vacuum cleaner via a hose connected to the intake manifold. Air then travels down the canisters, where particulate material is accumulated in generally equal quantities in each filter bag. Four air paths of bag filtered air then pass radially inward to the bottom of the central cylinder. Air moves up the central cylinder, through the HEPA filter, through a vacuum fan compartment, and exits the vacuum cleaner. A float air flow valve is mounted at the top of the central cylinder. When liquid accumulates to a given level within the central cylinder, the four bypass tubes, and the four canisters, suction is terminated by operation of the float valve.

Troubleshooting crude vacuum tower overhead ejector systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lines, J.R.; Frens, L.L.

1995-03-01

Routinely surveying tower overhead vacuum systems can improve performance and product quality. These vacuum systems normally provide reliable and consistent operation. However, process conditions, supplied utilities, corrosion, erosion and fouling all have an impact on ejector system performance. Refinery vacuum distillation towers use ejector systems to maintain tower top pressure and remove overhead gases. However, as with virtually all refinery equipment, performance may be affected by a number of variables. These variables may act independently or concurrently. It is important to understand basic operating principles of vacuum systems and how performance is affected by: utilities, corrosion and erosion, fouling, andmore » process conditions. Reputable vacuum-system suppliers have service engineers that will come to a refinery to survey the system and troubleshoot performance or offer suggestions for improvement. A skilled vacuum-system engineer may be needed to diagnose and remedy system problems. The affect of these variables on performance is discussed. A case history is described of a vacuum system on a crude tower in a South American refinery.« less

Magnet Assisted Composite Manufacturing: A Flexible New Technique for Achieving High Consolidation Pressure in Vacuum Bag/Lay-Up Processes.

PubMed

Pishvar, Maya; Amirkhosravi, Mehrad; Altan, M Cengiz

2018-05-17

This work demonstrates a protocol to improve the quality of composite laminates fabricated by wet lay-up vacuum bag processes using the recently developed magnet assisted composite manufacturing (MACM) technique. In this technique, permanent magnets are utilized to apply a sufficiently high consolidation pressure during the curing stage. To enhance the intensity of the magnetic field, and thus, to increase the magnetic compaction pressure, the magnets are placed on a magnetic top plate. First, the entire procedure of preparing the composite lay-up on a magnetic bottom steel plate using the conventional wet lay-up vacuum bag process is described. Second, placement of a set of Neodymium-Iron-Boron permanent magnets, arranged in alternating polarity, on the vacuum bag is illustrated. Next, the experimental procedures to measure the magnetic compaction pressure and volume fractions of the composite constituents are presented. Finally, methods used to characterize microstructure and mechanical properties of composite laminates are discussed in detail. The results prove the effectiveness of the MACM method in improving the quality of wet lay-up vacuum bag laminates. This method does not require large capital investment for tooling or equipment and can also be used to consolidate geometrically complex composite parts by placing the magnets on a matching top mold positioned on the vacuum bag.

The determination of optimum condition in water hyacinth drying process by mixed adsorption drying method and modified fly ash as an adsorbent

NASA Astrophysics Data System (ADS)

Saputra, Asep Handaya; Putri, Rizky Anggreini

2017-05-01

Water hyacinth is an aquatic weed that has a very fast growth which makes it becomes a problem to the ecosystem. On the other hand, water hyacinth has a high fiber content (up to 20% by weight) which makes it potential to become raw material for composites and textile industries. As an aquatic plant, water hyacinth has a high initial moisture content that reaches more than 90%. Meanwhile the moisture content of fiber as a raw material for composite and textile industry should not be more than 10% to maintain the good quality of the products. Mixed adsorption drying method is one of the innovative method that can replace conventional drying process. Fluidization method which has been commonly used in agricultural and pharmaceutical products drying, can be enhanced by combining it with the adsorption method as performed in this study. In mixed fluidization-adsorption drying method, fly ash as adsorbent and water hyacinth fiber were put together into the fluidization column where the drying air evaporate the moisture content in water hyacinth fiber. In addition, the adsorbent adsorb the moisture content in the drying air to make the moisture content of the drying air remain low. The drying process is performed in various temperature and composition of water hyacinth and adsorbent in order to obtain the optimum drying condition. In addition, the effect of fly ash pellet and fly ash powder to the drying process was also performed. The result shows that the higher temperature and the more amount of adsorbent results in the faster drying rate. Fly ash pellet shows a better adsorption since it has a smaller pore diameter and wider surface area. The optimum temperature obtained from this study is 60°C and the optimum ratio of water hyacinth and fly ash is 50:50.

Light assisted drying (LAD) for protein stabilization: optimization of laser processing parameters

NASA Astrophysics Data System (ADS)

Young, Madison A.; Antczak, Andrew T.; Elliott, Gloria D.; Trammell, Susan R.

2017-02-01

In this study, a novel light-based processing method to create an amorphous trehalose matrix for the stabilization of proteins is discussed. Near-IR radiation is used to remove water from samples, leaving behind an amorphous solid with embedded protein. This method has potential applications in the stabilization of protein-based therapeutics and diagnostics that are becoming widely used in the treatment and diagnosis of a variety of diseases. Freeze-drying or freezing are currently the standard for the preservation of proteins, but these methods are expensive and can be challenging in some environments due to a lack of available infrastructure. Light-assisted drying offers a relatively inexpensive method for drying samples. Proteins suspended in a trehalose solution are dehydrated using near-infrared laser light. The laser radiation speeds drying and as water is removed the sugar forms a protective matrix. The goal of this study is to determine processing parameters that result in fast processing times and low end moisture contents (EMC), while maintaining the functionality of embedded proteins. We compare the effect of changing processing wavelength, power and resulting sample temperature, and substrate material on the EMC for two NIR laser sources (1064 nm and 1850 nm). The 1850 nm laser resulted in the lowest EMC (0.1836+/-0.09 gH2O/gDryWeight) after 10 minutes of processing on borosilicate glass microfiber paper. This suggests a storage temperature of 3°C.

Characteristics of okara color change during convective drying process

NASA Astrophysics Data System (ADS)

Taruna, I.; Astuti, J.

2018-03-01

Okara is a byproduct of the tofu factory that is perishable in nature and requires an immediate handling and treatment to preserve it. Drying has been a preferred method since it can increase the product compactness. However, the majority of okara drying studies done in the past are disregarding the influences of process condition on color change characteristic. Hence, this work aimed to investigate the characteristic of okara color changes during convective drying at temperatures of 85, 100, and 115°C. The okara color was expressed in terms of L a b values and its derivative attributes, i.e. whiteness, hue angle, chroma and the total color difference. The results showed that an increase in drying time and temperatures decreased the lightness, yellowness and the total color difference, but conversely increased the redness of okara. Fitting of two exponential models to the experimental data revealed that the Page’s equation was better in predicting the okara color degradation than Newton’s model.

Comparison of release torques of tightened bolts in vacuum and air

NASA Technical Reports Server (NTRS)

Demorest, K. E.

1970-01-01

Various combinations of stainless steel, mild steel, and aluminum bolt-nut couples are tightened to 60 lb-ft in partial vacuum and in air. Results are given for tests with and without two lubricants /a fluorosilicone and a sodium silicate bonded dry-film/.

[Physical and chemical evaluation during refrigeration storage of salted catfish (Pseudoplatystoma sp.) in brine solution, and packed under vacuum].

PubMed

Rodríguez, Diana; Barrero, Marinela; Kodaira, Makie

2009-06-01

Salting fish in the south Venezuelan towns are still the main method of preserving fish including cutt, and salting fish process, storage and commercialization. As the result, salted-dried fish is particularly susceptible to spoilage by a number of factors, including lipid oxidation, browning meat. Packing salted fish product is an alternative increasing storage life time reducing lost of quality and enhancing the storage time. The present study evaluated the physic, chemist, and sensory quality of fish fillet from cat fish (Pseudoplatystoma sp.) from Apure state, Venezuela. Fillet fish were placed in brine solution at 36% of sodium chloride 1:2 fillet: brine solution; after, they were packed under followed conditions: vacuum, vacuum and storage under refrigeration condition, and room temperature. The results showed significant differences (p < 0.01) for moisture, salt content, and Aw. The fillets packed at vacuum and storage at 4 degrees C were significant different from the resting treatments; not significant differences were presented at room and refrigeration temperature after three moths. The best conditions treatment was vacuum packing and refrigeration at 4 degrees C.

Vacuum Technology Considerations For Mass Metrology

PubMed Central

Abbott, Patrick J.; Jabour, Zeina J.

2011-01-01

Vacuum weighing of mass artifacts eliminates the necessity of air buoyancy correction and its contribution to the measurement uncertainty. Vacuum weighing is also an important process in the experiments currently underway for the redefinition of the SI mass unit, the kilogram. Creating the optimum vacuum environment for mass metrology requires careful design and selection of construction materials, plumbing components, pumping, and pressure gauging technologies. We review the vacuum technology1 required for mass metrology and suggest procedures and hardware for successful and reproducible operation. PMID:26989593

Influence of ripeness and drying process on the polyphenols and tocopherols of Pistacia vera L.

PubMed

Ballistreri, Gabriele; Arena, Elena; Fallico, Biagio

2009-10-30

This paper highlights, for the first time, the changes in the phenolics fraction (anthocyanins, flavonoids and stilbenes) and tocopherols of unpeeled Pistacia vera L. var. bianca with ripening, and the effect of the sun-drying process. The total polyphenol levels in pistachios, measured as mg of Gallic Acid Equivalent (GAE), were: 201 +/- 10.1, 349 +/- 18.3 and 184.7 +/- 6.2 mg GAE/100 g DM in unripe, ripe and dried ripe samples, respectively. Most phenolics in ripe pistachios were found to be anthocyanins. They increased with ripening, while the sun drying process caused a susbtantial loss. Flavonoids found in all pistachio samples were daidzein, genistein, daidzin, quercetin, eriodictyol, luteolin, genistin and naringenin, which decreased both with ripening and drying. Before the drying process both unripe and ripe pistachios showed a higher content of trans-resveratrol than dried ripe samples. gamma-Tocopherol was the major vitamin E isomer found in pistachios. The total content (of alpha- and gamma-tocopherols) decreased, both during ripening and during the drying process. These results suggested that unpeeled pistachios can be considered an important source of phenolics, particularly of anthocyanins. Moreover, in order to preserve these healthy characteristics, new and more efficient drying processes should be adopted.

Microstructural and bulk property changes in hardened cement paste during the first drying process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maruyama, Ippei, E-mail: ippei@dali.nuac.nagoya-u.ac.jp; Nishioka, Yukiko; Igarashi, Go

2014-04-01

This paper reports the microstructural changes and resultant bulk physical property changes in hardened cement paste (hcp) during the first desorption process. The microstructural changes and solid-phase changes were evaluated by water vapor sorption, nitrogen sorption, ultrasonic velocity, and {sup 29}Si and {sup 27}Al nuclear magnetic resonance. Strength, Young's modulus, and drying shrinkage were also examined. The first drying process increased the volume of macropores and decreased the volume of mesopores and interlayer spaces. Furthermore, in the first drying process globule clusters were interconnected. During the first desorption, the strength increased for samples cured at 100% to 90% RH, decreasedmore » for 90% to 40% RH, and increased again for 40% to 11% RH. This behavior is explained by both microstructural changes in hcp and C–S–H globule densification. The drying shrinkage strains during rapid drying and slow drying were compared and the effects of the microstructural changes and evaporation were separated.« less

Vacuum force

NASA Astrophysics Data System (ADS)

Han, Yongquan

2015-03-01

To study on vacuum force, we must clear what is vacuum, vacuum is a space do not have any air and also ray. There is not exist an absolute the vacuum of space. The vacuum of space is relative, so that the vacuum force is relative. There is a certain that vacuum vacuum space exists. In fact, the vacuum space is relative, if the two spaces compared to the existence of relative vacuum, there must exist a vacuum force, and the direction of the vacuum force point to the vacuum region. Any object rotates and radiates. Rotate bend radiate- centripetal, gravity produced, relative gravity; non gravity is the vacuum force. Gravity is centripetal, is a trend that the objects who attracted wants to Centripetal, or have been do Centripetal movement. Any object moves, so gravity makes the object curve movement, that is to say, the radiation range curve movement must be in the gravitational objects, gravity must be existed in non vacuum region, and make the object who is in the region of do curve movement (for example: The earth moves around the sun), or final attracted in the form gravitational objects, and keep relatively static with attract object. (for example: objects on the earth moves but can't reach the first cosmic speed).

Diffusion welding. [heat treatment of nickel alloys following single step vacuum welding process

NASA Technical Reports Server (NTRS)

Holko, K. H. (Inventor)

1974-01-01

Dispersion-strengthened nickel alloys are sanded on one side and chemically polished. This is followed by a single-step welding process wherein the polished surfaces are forced into intimate contact at 1,400 F for one hour in a vacuum. Diffusion, recrystallization, and grain growth across the original weld interface are obtained during postheating at 2,150 F for two hours in hydrogen.

K(3)EDTA Vacuum Tubes Validation for Routine Hematological Testing.

PubMed

Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Poli, Giovanni; Solero, Giovanni Pietro; Picheth, Geraldo; Guidi, Gian Cesare

2012-01-01

Background and Objective. Some in vitro diagnostic devices (e.g, blood collection vacuum tubes and syringes for blood analyses) are not validated before the quality laboratory managers decide to start using or to change the brand. Frequently, the laboratory or hospital managers select the vacuum tubes for blood collection based on cost considerations or on relevance of a brand. The aim of this study was to validate two dry K(3)EDTA vacuum tubes of different brands for routine hematological testing. Methods. Blood specimens from 100 volunteers in two different K(3)EDTA vacuum tubes were collected by a single, expert phlebotomist. The routine hematological testing was done on Advia 2120i hematology system. The significance of the differences between samples was assessed by paired Student's t-test after checking for normality. The level of statistical significance was set at P < 0.05. Results and Conclusions. Different brand's tubes evaluated can represent a clinically relevant source of variations only on mean platelet volume (MPV) and platelet distribution width (PDW). Basically, our validation will permit the laboratory or hospital managers to select the brand's vacuum tubes validated according to him/her technical or economical reasons for routine hematological tests.

A Hydration of an Alkyne Illustrating Steam and Vacuum Distillation.

ERIC Educational Resources Information Center

Wasacz, J. P.; Badding, V. G.

1982-01-01

Reports on the conversion 2,5-dimethylhexyne-2,5-diol(I) to 2,2,5,5-tetramethyltetrahydrofuran-3-one(II) using aqueous mercuric sulfate without the use of acid. The experiment has been successfully performed in introductory organic chemistry laboratories demonstrating alkyne hydration, steam distillation, vacuum distillation, drying of organic…

Evaluating the process parameters of the dry coating process using a 2(5-1) factorial design.

PubMed

Kablitz, Caroline Désirée; Urbanetz, Nora Anne

2013-02-01

A recent development of coating technology is dry coating, where polymer powder and liquid plasticizer are layered on the cores without using organic solvents or water. Several studies evaluating the process were introduced in literature, however, little information about the critical process parameters (CPPs) is given. Aim of the study was the investigation and optimization of CPPs with respect to one of the critical quality attributes (CQAs), the coating efficiency of the dry coating process in a rotary fluid bed. Theophylline pellets were coated with hydroxypropyl methylcellulose acetate succinate as enteric film former and triethyl citrate and acetylated monoglyceride as plasticizer. A 2(5-1) design of experiments (DOEs) was created investigating five independent process parameters namely coating temperature, curing temperature, feeding/spraying rate, air flow and rotor speed. The results were evaluated by multilinear regression using the software Modde(®) 7. It is shown, that generally, low feeding/spraying rates and low rotor speeds increase coating efficiency. High coating temperatures enhance coating efficiency, whereas medium curing temperatures have been found to be optimum in terms of coating efficiency. This study provides a scientific base for the design of efficient dry coating processes with respect to coating efficiency.

A three-mask process for fabricating vacuum-sealed capacitive micromachined ultrasonic transducers using anodic bonding.

PubMed

Yamaner, F Yalçın; Zhang, Xiao; Oralkan, Ömer

2015-05-01

This paper introduces a simplified fabrication method for vacuum-sealed capacitive micromachined ultrasonic transducer (CMUT) arrays using anodic bonding. Anodic bonding provides the established advantages of wafer-bondingbased CMUT fabrication processes, including process simplicity, control over plate thickness and properties, high fill factor, and ability to implement large vibrating cells. In addition to these, compared with fusion bonding, anodic bonding can be performed at lower processing temperatures, i.e., 350°C as opposed to 1100°C; surface roughness requirement for anodic bonding is more than 10 times more relaxed, i.e., 5-nm rootmean- square (RMS) roughness as opposed to 0.5 nm for fusion bonding; anodic bonding can be performed on smaller contact area and hence improves the fill factor for CMUTs. Although anodic bonding has been previously used for CMUT fabrication, a CMUT with a vacuum cavity could not have been achieved, mainly because gas is trapped inside the cavities during anodic bonding. In the approach we present in this paper, the vacuum cavity is achieved by opening a channel in the plate structure to evacuate the trapped gas and subsequently sealing this channel by conformal silicon nitride deposition in the vacuum environment. The plate structure of the fabricated CMUT consists of the single-crystal silicon device layer of a silicon-on-insulator wafer and a thin silicon nitride insulation layer. The presented fabrication approach employs only three photolithographic steps and combines the advantages of anodic bonding with the advantages of a patterned metal bottom electrode on an insulating substrate, specifically low parasitic series resistance and low parasitic shunt capacitance. In this paper, the developed fabrication scheme is described in detail, including process recipes. The fabricated transducers are characterized using electrical input impedance measurements in air and hydrophone measurements in immersion. A representative

Hybrid Drying of Carrot Preliminary Processed with Ultrasonically Assisted Osmotic Dehydration

PubMed Central

2017-01-01

Summary In this paper the kinetics of osmotic dehydration of carrot and the influence of this pretreatment on the post-drying processes and the quality of obtained products are analysed. Osmotic dehydration was carried out in the aqueous fructose solution in two different ways: with and without ultrasound assistance. In the first part of the research, the kinetics of osmotic dehydration was analysed on the basis of osmotic dewatering rate, water loss and solid gain. Next, the effective time of dehydration was determined and in the second part of research samples were initially dehydrated for 30 min and dried. Five different procedures of drying were established on the grounds of convective method enhanced with microwave and infrared radiation. The influence of osmotic dehydration on the drying kinetics and final product quality was analysed. It was found that it did not influence the drying kinetics significantly but positively affected the final product quality. Negligible influence on the drying kinetics was attributed to solid uptake, which may block the pores, hindering heat and mass transfer. It was also concluded that the application of microwave and/or infrared radiation during convective drying significantly influenced the kinetics of the final stage of drying. A proper combination of aforementioned techniques of hybrid drying allows reducing the drying time. Differences between the particular dehydration methods and drying schedules were discussed. PMID:28867949

Ultrahigh vacuum process for the deposition of nanotubes and nanowires

DOEpatents

Das, Biswajit; Lee, Myung B

2015-02-03

A system and method A method of growing an elongate nanoelement from a growth surface includes: a) cleaning a growth surface on a base element; b) providing an ultrahigh vacuum reaction environment over the cleaned growth surface; c) generating a reactive gas of an atomic material to be used in forming the nanoelement; d) projecting a stream of the reactive gas at the growth surface within the reactive environment while maintaining a vacuum of at most 1.times.10.sup.-4 Pascal; e) growing the elongate nanoelement from the growth surface within the environment while maintaining the pressure of step c); f) after a desired length of nanoelement is attained within the environment, stopping direction of reactive gas into the environment; and g) returning the environment to an ultrahigh vacuum condition.

Degradation of carotenoids in apricot (Prunus armeniaca L.) during drying process.

PubMed

Fratianni, Alessandra; Albanese, Donatella; Mignogna, Rossella; Cinquanta, Luciano; Panfili, Gianfranco; Di Matteo, Marisa

2013-09-01

Carotenoids are natural compounds whose nutritional importance comes from the provitamin A activity of some of them and their protection against several serious human disorders. The degradation of carotenoids was investigated during apricot drying by microwave and convective hot-air at 60 and 70 °C. Seven carotenoids were identified: antheraxanthin, lutein, zeaxanthin, β-cryptoxanthin, 13-cis-β-carotene, all-trans-β-carotene and 9-cis-β-carotene; among these, all-trans-β-carotene was found to be about 50 % of total carotenoids. First-order kinetic models were found to better describe all-trans-β-carotene reduction during drying, with a degradation rate constant (k1) that increased two folds when temperatures increased by 10 °C, in both methods. No differences were found in k1 between apricots dried by hot air at 70 °C (k1 = 0.0340 h(-1)) and by microwave at 60 °C. The evolution of total carotenoids (117.1 mg/kg on dry basis) during drying highlighted a wider decrease (about 50%) when microwave heating was employed, for both set temperatures. Antheraxantin was found to be the carotenoid most susceptible to heat, disappearing at 6 h during both trials with microwave as well as during convective hot-air at 70 °C. For this reason, antheraxanthin could be a useful marker for the evaluation of thermal damage due to the drying process. Also the degree of isomerization of all-trans-β-carotene could be a useful marker for the evaluation of the drying process.

EPA SITE DEMONSTRATION OF THE TERRA VAC IN SITU VACUUM EXTRACTION PROCESS IN GROVELAND, MASSACHUSETTS

EPA Science Inventory

This paper presents an EPA evaluation of the patented Terra Vac, Inc.'s in situ vacuum extraction process that was field-demonstrated on a trichloroethylene (TCE) contaminated soil in Groveland, MA, under the EPA Superfund Innovative Technology Evaluation (SITE) program. he Terra...

7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... QUARANTINE NOTICES Fruits and Vegetables § 319.56-11 Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes. (a) Dried, cured, or processed fruits and vegetables (except frozen fruits and... 7 Agriculture 5 2014-01-01 2014-01-01 false Importation of dried, cured, or processed fruits...

7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... QUARANTINE NOTICES Fruits and Vegetables § 319.56-11 Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes. (a) Dried, cured, or processed fruits and vegetables (except frozen fruits and... 7 Agriculture 5 2013-01-01 2013-01-01 false Importation of dried, cured, or processed fruits...

7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.

Code of Federal Regulations, 2012 CFR

2012-01-01

... QUARANTINE NOTICES Fruits and Vegetables § 319.56-11 Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes. (a) Dried, cured, or processed fruits and vegetables (except frozen fruits and... 7 Agriculture 5 2012-01-01 2012-01-01 false Importation of dried, cured, or processed fruits...

Bioactive compounds and quality parameters of avocado oil obtained by different processes.

PubMed

Krumreich, Fernanda D; Borges, Caroline D; Mendonça, Carla Rosane B; Jansen-Alves, Cristina; Zambiazi, Rui C

2018-08-15

The objective of this study was to evaluate the quality of avocado oil whose pulp was processed through different drying and oil extraction methods. The physicochemical characteristics of avocados cv. Breda were determined after drying the pulp in an oven under ventilation (40 °C and 60 °C) and vacuum oven (60 °C), followed by the oil extracted by mechanical pressing or the Soxhlet method. From the approximately 72% pulp found in the avocado fruit, the 16% fraction is lipids. The quality indices evaluated in avocado oil showed better results when the pulp was dried at 60 °C under vacuum and oil extraction was done by the Soxhlet method with petroleum ether, whereas the bioactive compounds were better preserved when the avocado pulp was dried at 60 °C under ventilation and mechanical pressing was used for the oil extraction. Among the fatty acids found, oleic acid was the main. Copyright © 2018 Elsevier Ltd. All rights reserved.

Nonthermal combined ultraviolet and vacuum-ultraviolet curing process for organosilicate dielectrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, H.; Guo, X.; Pei, D.

2016-06-13

Porous SiCOH films are of great interest in semiconductor fabrication due to their low-dielectric constant properties. Post-deposition treatments using ultraviolet (UV) light on organosilicate thin films are required to decompose labile pore generators (porogens) and to ensure optimum network formation to improve the electrical and mechanical properties of low-k dielectrics. The goal of this work is to choose the best vacuum-ultraviolet photon energy in conjunction with vacuum ultraviolet (VUV) photons without the need for heating the dielectric to identify those wavelengths that will have the most beneficial effect on improving the dielectric properties and minimizing damage. VUV irradiation between 8.3more » and 8.9 eV was found to increase the hardness and elastic modulus of low-k dielectrics at room temperature. Combined with UV exposures of 6.2 eV, it was found that this “UV/VUV curing” process is improved compared with current UV curing. We show that UV/VUV curing can overcome drawbacks of UV curing and improve the properties of dielectrics more efficiently without the need for high-temperature heating of the dielectric.« less

Sensory profiles for dried fig (Ficus carica L.) cultivars commercially grown and processed in California.

PubMed

Haug, Megan T; King, Ellena S; Heymann, Hildegarde; Crisosto, Carlos H

2013-08-01

A trained sensory panel evaluated the 6 fig cultivars currently sold in the California dried fig market. The main flavor and aroma attributes determined by the sensory panel were "caramel," "honey," "raisin," and "fig," with additional aroma attributes: "common date," "dried plum," and "molasses." Sensory differences were observed between dried fig cultivars. All figs were processed by 2 commercial handlers. Processing included potassium sorbate as a preservative and SO2 application as an antibrowning agent for white cultivars. As a consequence of SO2 use during processing, high sulfite residues affected the sensory profiles of the white dried fig cultivars. Significant differences between dried fig cultivars and sources demonstrate perceived differences between processing and storage methods. The panel-determined sensory lexicon can help with California fig marketing. © 2013 The Regents of California, Davis Campus Department of Plant Sciences.

Effects of drying process on the physicochemical properties of nopal cladodes at different maturity stages.

PubMed

Contreras-Padilla, Margarita; Gutiérrez-Cortez, Elsa; Valderrama-Bravo, María Del Carmen; Rojas-Molina, Isela; Espinosa-Arbeláez, Diego Germán; Suárez-Vargas, Raúl; Rodríguez-García, Mario Enrique

2012-03-01

Chemical proximate analysis was done in order to determine the changes of nutritional characteristics of nopal powders from three different maturity stages 50, 100, and 150 days and obtained by three different drying processes: freeze dried, forced air oven, and tunnel. Results indicate that nopal powder obtained by the process of freeze dried retains higher contents of protein, soluble fiber, and fat than the other two processes. Also, freeze dried process had less effect on color hue variable. No changes were observed in insoluble fiber content, chroma and lightness with the three different drying processes. Furthermore, the soluble fibers decreased with the age of nopal while insoluble fibers and ash content shows an opposite trend. In addition, the luminosity and hue values did not show differences among the maturity stages studied. The high content of dietary fibers of nopal pad powder could to be an interesting source of these important components for human diets and also could be used in food, cosmetics and pharmaceutical industry.

Classification of dried vegetables using computer image analysis and artificial neural networks

NASA Astrophysics Data System (ADS)

Koszela, K.; Łukomski, M.; Mueller, W.; Górna, K.; Okoń, P.; Boniecki, P.; Zaborowicz, M.; Wojcieszak, D.

2017-07-01

In the recent years, there has been a continuously increasing demand for vegetables and dried vegetables. This trend affects the growth of the dehydration industry in Poland helping to exploit excess production. More and more often dried vegetables are used in various sectors of the food industry, both due to their high nutritional qualities and changes in consumers' food preferences. As we observe an increase in consumer awareness regarding a healthy lifestyle and a boom in health food, there is also an increase in the consumption of such food, which means that the production and crop area can increase further. Among the dried vegetables, dried carrots play a strategic role due to their wide application range and high nutritional value. They contain high concentrations of carotene and sugar which is present in the form of crystals. Carrots are also the vegetables which are most often subjected to a wide range of dehydration processes; this makes it difficult to perform a reliable qualitative assessment and classification of this dried product. The many qualitative properties of dried carrots determining their positive or negative quality assessment include colour and shape. The aim of the research was to develop and implement the model of a computer system for the recognition and classification of freeze-dried, convection-dried and microwave vacuum dried products using the methods of computer image analysis and artificial neural networks.

Purifying Aluminum by Vacuum Distillation

NASA Technical Reports Server (NTRS)

Du Fresne, E. R.

1985-01-01

Proposed method for purifying aluminum employs one-step vacuum distillation. Raw material for process impure aluminum produced in electrolysis of aluminum ore. Impure metal melted in vacuum. Since aluminum has much higher vapor pressure than other constituents, boils off and condenses on nearby cold surfaces in proportions much greater than those of other constituents.

The surface topography of the choroid plexus. Environmental, low and high vacuum scanning electron microscopy.

PubMed

Mestres, Pedro; Pütz, Norbert; Garcia Gómez de Las Heras, Soledad; García Poblete, Eduardo; Morguet, Andrea; Laue, Michael

2011-05-01

Environmental scanning electron microscopy (ESEM) allows the examination of hydrated and dried specimens without a conductive metal coating which could be advantageous in the imaging of biological and medical objects. The aim of this study was to assess the performance and benefits of wet-mode and low vacuum ESEM in comparison to high vacuum scanning electron microscopy (SEM) using the choroid plexus of chicken embryos as a model, an organ of the brain involved in the formation of cerebrospinal fluid in vertebrates. Specimens were fixed with or without heavy metals and examined directly or after critical point drying with or without metal coating. For wet mode ESEM freshly excised specimens without any pre-treatment were also examined. Conventional high vacuum SEM revealed the characteristic morphology of the choroid plexus cells at a high resolution and served as reference. With low vacuum ESEM of dried but uncoated samples the structure appeared well preserved but charging was a problem. It could be reduced by a short beam dwell time and averaging of images or by using the backscattered electron detector instead of the gaseous secondary electron detector. However, resolution was lower than with conventional SEM. Wet mode imaging was only possible with tissue that had been stabilized by fixation. Not all surface details (e.g. microvilli) could be visualized and other structures, like the cilia, were deformed. In summary, ESEM is an additional option for the imaging of bio-medical samples but it is problematic with regard to resolution and sample stability during imaging. Copyright © 2011 Elsevier GmbH. All rights reserved.

Effects of Planting and Processing Modes on the Degradation of Dithianon and Pyraclostrobin in Chinese Yam (Dioscorea spp.).

PubMed

Shi, Kaiwei; Wu, Xujin; Ma, Jingwei; Zhang, Junfeng; Zhou, Ling; Wang, Hong; Li, Li

2017-12-06

The yam (Dioscorea spp.) is widely cultivated in China. The degradation of dithianon and pyraclostrobin in yams with different planting and processing treatments was investigated in this article. An analytical method for two pesticides in yam and yam plant was developed, and recoveries were between 77% and 93%, with relative standard deviations from 0.8% to 7.4%, respectively. On the basis of this method, half-lives for plants grown on stakes versus plants grown without stakes were compared. The results indicated that the half-life for pesticide residues for plants grown on stakes versus plants grown without stakes differed as 6.7 versus 3.1 days for dithianon and 5.4 versus 5.2 days for pyraclostrobin. Dithianon was significantly influenced by planting mode because of its low stability under sunlight. The processing factors of various processing treatments (hot air-drying, vacuum freeze-drying, microwave vacuum-drying, infrared-drying, steaming, and boiling) were all <1, indicating that those processes can reduce residues of two pesticides at different levels. Significant amounts of residues were removed during the boiling treatment, whereas the others showed less effect.

Development of a large low-cost double-chamber vacuum laminator

NASA Technical Reports Server (NTRS)

Burger, D. R.

1983-01-01

A double-chamber vacuum laminator was required to investigate the processing and control of the fabrication of large terrestrial photovoltaic modules, and economic problems arising therefrom. Major design considerations were low cost, process flexibility and the exploration of novel equipment approaches. Spherical end caps for industrial tanks were used for the vacuum chambers. A stepping programmer and adjustable timers were used for process flexibility. New processing options were obtained by use of vacuum sensors. The upper vacuum chamber was provided with a diaphragm support to reduce diaphragm stress. A counterweight was used for handling ease and safety. Heat was supplied by a large electrical strip heater. Thermal isolation and mechanical support were provided inexpensively by a bed of industrial marbles. Operational testing disclosed the need for a differential vacuum gauge and proportional valve. Reprogramming of the process control system was simple and quick.

Report on UQ and PCMM Analysis of Vacuum Drying for UFD S&T Gaps

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. Fluss

2015-08-31

This report discusses two phenomena that could affect the safety, licensing, transportation, storage, and disposition of the spent fuel storage casks and their contents (radial hydriding during drying and water retention after drying) associated with the drying of canisters for dry spent fuel storage. The report discusses modeling frameworks and evaluations that are, or have been, developed as a means to better understand these phenomena. Where applicable, the report also discusses data needs and procedures for monitoring or evaluating the condition of storage containers during and after drying. A recommendation for the manufacturing of a fully passivated fuel rod, resistantmore » to oxidation and hydriding is outlined.« less

Influence of drying methods over in vitro antitumoral effects of exopolysaccharides produced by Agaricus blazei LPB 03 on submerged fermentation.

PubMed

Fernandes, M B A; Habu, S; de Lima, M A; Thomaz-Soccol, V; Soccol, C R

2011-03-01

Agaricus blazei is a mushroom that belongs to the Brazilian biodiversity and is considered as an important producer of bioactive compounds beneficial to human health. Studies have demonstrated that these compounds present immuno-modulatory, antioxidant and antitumor properties. In order to compare the most used method for fungal polysaccharide drying, lyophilization with other industrial-scale methods, the aim of this work was to submit A. blazei LPB 03 polysaccharide extracts to vaucum, spray and freeze drying, and evaluate the maintenance of its antitumoral effects in vitro. Exopolysaccharides produced by A. blazei LPB 03 on submerged fermentation were extracted with ethanol and submitted to drying processes. The efficiency represents the water content that was removed during the drying process. The resultant dried products showed water content around 3% and water activity less than 0.380, preventing therefore the growth of microorganisms and reactions of chemical degradation. Exopolysaccharide extracts dried by vacuum and spray dryer did not showed any significant cytotoxic effect on cell viability of Wistar mice macrophages. Content of total sugars and protein decrease after drying, nevertheless, 20 mg/ml of exopolysaccharides dried by spray dryer reached 33% of inhibition rate over Ehrlich tumor cells in vitro.

[Characteristics of odors and VOCs from sludge direct drying process].

PubMed

Chen, Wen-He; Deng, Ming-Jia; Luo, Hui; Zhang, Jing-Ying; Ding, Wen-Jie; Liu, Jun-Xin; Liu, Jun-Xin

2014-08-01

Co-processing sewage sludge by using the high-temperature feature of cement kiln can realize harmless disposal and energy recycling. In this paper, investigation on characteristics of the flue gas from sludge drying process was carried out in Guangzhou Heidelberg Yuexiu Cement Co., LTD. The composition and the main source of odors and volatile organic compounds (VOCs) emitted during the drying process were analyzed, aimed to provide scientific basis for the treatment of sewage sludge. Results showed that there were a large number of malodorous substances and VOCs in the flue gas. Sulfur dioxide and other sulfur-containing compounds were the main components in the malodorous substances, while benzene derivatives were predominant in VOCs. The compositions of odors and VOCs were influenced by the characteristics of the sludge and the heat medium (kiln tail gas). Total organic compounds in the sludge were significantly decreased after drying. Other organic substances such as volatile fatty acid, protein, and polysaccharide were also obviously reduced. The organic matter in sludge was the main source of VOCs in the flue gas. Part of sulfurous substances, such as sulfur dioxide, carbon disulfide, were from sulfur-containing substances in the sludge, and the rest were from the kiln tail gas itself.

[Effects of different drying methods on processing performance and quality in bulbus of Tulipa edulis].

PubMed

Yang, Xiao-hua; Guo, Qiao-sheng; Zhu, Zai-biao; Chen, Jun; Miao, Yuan-yuan; Yang, Ying; Sun, Yuan

2015-10-01

Effects of different drying methods including sun drying, steamed, boiled, constant temperature drying (at 40, 50, 60 °C) on appearance, hardness, rehydration ratio, dry rate, moisture, total ash, extractive and polysaccharides contents were studied to provide the basis of standard processing method for Tulipa edulis bulbus. The results showed that the treatments of sun drying and 40 °C drying showed higher rehydration ratios, but lower dry rate, higher hardness, worse color, longer time and obvious distortion and shrinkage in comparison with other drying methods. The treatments of 60 °C constant temperature drying resulted in shorter drying time, lower water and higher polysaccharides content. Drying time is shorter and appearance quality is better in the treatment of steaming and boiling compared with other treatments, but the content of extractive and polysaccharides decreased significantly. The treatments of 50 °C constant temperature drying led to similar appearance quality of bulb to commercial bulb, and it resulted in lowest hardness and highest dry rate as well as higher rehydration ratio, extractive and polysaccharides content, moderate moisture and total ash contents among these treatments. Based on the results obtained, 50 °C constant temperature drying is the better way for the processing of T. edulis bulbus.

On the technological development of cotton primary processing, using a new drying-purifying unit

NASA Astrophysics Data System (ADS)

Agzamov, M. M.; Yunusov, S. Z.; Gafurov, J. K.

2017-10-01

The article reflects feasibility study of conducting research on technological development of cotton primary processing with the modified parameters of drying and cleaning process for small litter. As a result of theoretical and experimental research, drying and purifying unit is designed, in which in the existing processes a heat source, exhaust fans, a dryer drum, a peg-drum cleaner of cotton and the vehicle transmitting raw cotton from the dryer to the purifier will be excluded. The experience has shown that when a drying-purifying unit is installed (with eight wheels) purifying effect on the small litter of 34%, ie cleaning effect is higher than of that currently in operation 1XK drum cleaner. According to the research patent of RU UZ FAP 00674 “Apparatus for drying and cleaning fibrous material” is received.

Mechanistic modelling of fluidized bed drying processes of wet porous granules: a review.

PubMed

Mortier, Séverine Thérèse F C; De Beer, Thomas; Gernaey, Krist V; Remon, Jean Paul; Vervaet, Chris; Nopens, Ingmar

2011-10-01

Fluidized bed dryers are frequently used in industrial applications and also in the pharmaceutical industry. The general incentives to develop mechanistic models for pharmaceutical processes are listed, and our vision on how this can particularly be done for fluidized bed drying processes of wet granules is given. This review provides a basis for future mechanistic model development for the drying process of wet granules in pharmaceutical processes. It is intended for a broad audience with a varying level of knowledge on pharmaceutical processes and mathematical modelling. Mathematical models are powerful tools to gain process insight and eventually develop well-controlled processes. The level of detail embedded in such a model depends on the goal of the model. Several models have therefore been proposed in the literature and are reviewed here. The drying behaviour of one single granule, a porous particle, can be described using the continuum approach, the pore network modelling method and the shrinkage of the diameter of the wet core approach. As several granules dry at a drying rate dependent on the gas temperature, gas velocity, porosity, etc., the moisture content of a batch of granules will reside in a certain interval. Population Balance Model (ling) (PBM) offers a tool to describe the distribution of particle properties which can be of interest for the application. PBM formulation and solution methods are therefore reviewed. In a fluidized bed, the granules show a fluidization pattern depending on the geometry of the gas inlet, the gas velocity, characteristics of the particles, the dryer design, etc. Computational Fluid Dynamics (CFD) allows to model this behaviour. Moreover, turbulence can be modelled using several approaches: Reynolds-averaged Navier-Stokes Equations (RANS) or Large Eddy Simulation (LES). Another important aspect of CFD is the choice between the Eulerian-Lagrangian and the Eulerian-Eulerian approach. Finally, the PBM and CFD frameworks

Gene expression programming approach for the estimation of moisture ratio in herbal plants drying with vacuum heat pump dryer

NASA Astrophysics Data System (ADS)

Dikmen, Erkan; Ayaz, Mahir; Gül, Doğan; Şahin, Arzu Şencan

2017-07-01

The determination of drying behavior of herbal plants is a complex process. In this study, gene expression programming (GEP) model was used to determine drying behavior of herbal plants as fresh sweet basil, parsley and dill leaves. Time and drying temperatures are input parameters for the estimation of moisture ratio of herbal plants. The results of the GEP model are compared with experimental drying data. The statistical values as mean absolute percentage error, root-mean-squared error and R-square are used to calculate the difference between values predicted by the GEP model and the values actually observed from the experimental study. It was found that the results of the GEP model and experimental study are in moderately well agreement. The results have shown that the GEP model can be considered as an efficient modelling technique for the prediction of moisture ratio of herbal plants.

Developing a vacuum cooking equipment prototype to produce strawberry jam and optimization of vacuum cooking conditions.

PubMed

Okut, Dilara; Devseren, Esra; Koç, Mehmet; Ocak, Özgül Özdestan; Karataş, Haluk; Kaymak-Ertekin, Figen

2018-01-01

Purpose of this study was to develop prototype cooking equipment that can work at reduced pressure and to evaluate its performance for production of strawberry jam. The effect of vacuum cooking conditions on color soluble solid content, reducing sugars total sugars HMF and sensory properties were investigated. Also, the optimum vacuum cooking conditions for strawberry jam were optimized for Composite Rotatable Design. The optimum cooking temperature and time were determined targeting maximum soluble solid content and sensory attributes (consistency) and minimum Hue value and HMF content. The optimum vacuum cooking conditions determined were 74.4 °C temperature and 19.8 time. The soluble solid content strawberry jam made by vacuum process were similar to those prepared by traditional method. HMF contents of jams produced with vacuum cooking method were well within limit of standards.

K3EDTA Vacuum Tubes Validation for Routine Hematological Testing

PubMed Central

Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Poli, Giovanni; Solero, Giovanni Pietro; Picheth, Geraldo; Guidi, Gian Cesare

2012-01-01

Background and Objective. Some in vitro diagnostic devices (e.g, blood collection vacuum tubes and syringes for blood analyses) are not validated before the quality laboratory managers decide to start using or to change the brand. Frequently, the laboratory or hospital managers select the vacuum tubes for blood collection based on cost considerations or on relevance of a brand. The aim of this study was to validate two dry K3EDTA vacuum tubes of different brands for routine hematological testing. Methods. Blood specimens from 100 volunteers in two different K3EDTA vacuum tubes were collected by a single, expert phlebotomist. The routine hematological testing was done on Advia 2120i hematology system. The significance of the differences between samples was assessed by paired Student's t-test after checking for normality. The level of statistical significance was set at P < 0.05. Results and Conclusions. Different brand's tubes evaluated can represent a clinically relevant source of variations only on mean platelet volume (MPV) and platelet distribution width (PDW). Basically, our validation will permit the laboratory or hospital managers to select the brand's vacuum tubes validated according to him/her technical or economical reasons for routine hematological tests. PMID:22888448

Infrared thermography for monitoring of freeze-drying processes: instrumental developments and preliminary results.

PubMed

Emteborg, Håkan; Zeleny, Reinhard; Charoud-Got, Jean; Martos, Gustavo; Lüddeke, Jörg; Schellin, Holger; Teipel, Katharina

2014-07-01

Coupling an infrared (IR) camera to a freeze dryer for on-line monitoring of freeze-drying cycles is described for the first time. Normally, product temperature is measured using a few invasive Pt-100 probes, resulting in poor spatial resolution. To overcome this, an IR camera was placed on a process-scale freeze dryer. Imaging took place every 120 s through a Germanium window comprising 30,000 measurement points obtained contact-free from -40 °C to 25 °C. Results are presented for an empty system, bulk drying of cheese slurry, and drying of 1 mL human serum in 150 vials. During freezing of the empty system, differences of more than 5 °C were measured on the shelf. Adding a tray to the empty system, a difference of more than 8 °C was observed. These temperature differences probably cause different ice structures affecting the drying speed during sublimation. A temperature difference of maximum 13 °C was observed in bulk mode during sublimation. When drying in vials, differences of more than 10 °C were observed. Gradually, the large temperature differences disappeared during secondary drying and products were transformed into uniformly dry cakes. The experimental data show that the IR camera is a highly versatile on-line monitoring tool for different kinds of freeze-drying processes. © 2014 European Union.

A modified dynamical model of drying process of polymer blend solution coated on a flat substrate

NASA Astrophysics Data System (ADS)

Kagami, Hiroyuki

2008-05-01

We have proposed and modified a model of drying process of polymer solution coated on a flat substrate for flat polymer film fabrication. And for example numerical simulation of the model reproduces a typical thickness profile of the polymer film formed after drying. Then we have clarified dependence of distribution of polymer molecules on a flat substrate on a various parameters based on analysis of numerical simulations. Then we drove nonlinear equations of drying process from the dynamical model and the fruits were reported. The subject of above studies was limited to solution having one kind of solute though the model could essentially deal with solution having some kinds of solutes. But nowadays discussion of drying process of a solution having some kinds of solutes is needed because drying process of solution having some kinds of solutes appears in many industrial scenes. Polymer blend solution is one instance. And typical resist consists of a few kinds of polymers. Then we introduced a dynamical model of drying process of polymer blend solution coated on a flat substrate and results of numerical simulations of the dynamical model. But above model was the simplest one. In this study, we modify above dynamical model of drying process of polymer blend solution adding effects that some parameters change with time as functions of some variables to it. Then we consider essence of drying process of polymer blend solution through comparison between results of numerical simulations of the modified model and those of the former model.

Freeze-drying process design by manometric temperature measurement: design of a smart freeze-dryer.

PubMed

Tang, Xiaolin Charlie; Nail, Steven L; Pikal, Michael J

2005-04-01

To develop a procedure based on manometric temperature measurement (MTM) and an expert system for good practices in freeze drying that will allow development of an optimized freeze-drying process during a single laboratory freeze-drying experiment. Freeze drying was performed with a FTS Dura-Stop/Dura-Top freeze dryer with the manometric temperature measurement software installed. Five percent solutions of glycine, sucrose, or mannitol with 2 ml to 4 ml fill in 5 ml vials were used, with all vials loaded on one shelf. Details of freezing, optimization of chamber pressure, target product temperature, and some aspects of secondary drying are determined by the expert system algorithms. MTM measurements were used to select the optimum shelf temperature, to determine drying end points, and to evaluate residual moisture content in real-time. MTM measurements were made at 1 hour or half-hour intervals during primary drying and secondary drying, with a data collection frequency of 4 points per second. The improved MTM equations were fit to pressure-time data generated by the MTM procedure using Microcal Origin software to obtain product temperature and dry layer resistance. Using heat and mass transfer theory, the MTM results were used to evaluate mass and heat transfer rates and to estimate the shelf temperature required to maintain the target product temperature. MTM product dry layer resistance is accurate until about two-thirds of total primary drying time is over, and the MTM product temperature is normally accurate almost to the end of primary drying provided that effective thermal shielding is used in the freeze-drying process. The primary drying times can be accurately estimated from mass transfer rates calculated very early in the run, and we find the target product temperature can be achieved and maintained with only a few adjustments of shelf temperature. The freeze-dryer overload conditions can be estimated by calculation of heat/mass flow at the target product

Simultaneous application of microwave energy and hot air to whole drying process of apple slices: drying kinetics, modeling, temperature profile and energy aspect

NASA Astrophysics Data System (ADS)

Horuz, Erhan; Bozkurt, Hüseyin; Karataş, Haluk; Maskan, Medeni

2018-02-01

Drying kinetics, modeling, temperature profile and energy indices were investigated in apple slices during drying by a specially designed microwave-hot air domestic hybrid oven at the following conditions: 120, 150 and 180 W microwave powers coupled with 50, 60 and 70 °C air temperatures. Both sources of energy were applied simultaneously during the whole drying processes. The drying process continued until the moisture content of apple slices reached to 20% from 86.3% (wet basis, w.b). Drying times ranged from 330 to 800 min and decreased with increasing microwave power and air temperatures. The constant rate period was only observed at low microwave powers and air temperatures. Two falling rate periods were observed. Temperature of apple slices sharply increased within the first 60 min, then reached equilibrium with drying medium and finally increased at the end of the drying process. In order to describe drying behavior of apple slices nine empirical models were applied. The Modified Logistic Model fitted the best our experimental data ( R 2 = 0.9955-0.9998; χ 2 = 3.46 × 10-5-7.85 × 10-4 and RMSE = 0.0052-0.0221). The effective moisture and thermal diffusivities were calculated by Fick's second law and ranged from 1.42 × 10-9 to 3.31 × 10-9 m2/s and 7.70 × 10-9 to 12.54 × 10-9 m2/s, respectively. The activation energy ( Ea) values were calculated from effective moisture diffusivity ( Deff), thermal diffusivity ( α) and the rate constant of the best model ( k). The Ea values found from these three terms were similar and varied from 13.04 to 33.52 kJ/mol. Energy consumption and specific energy requirement of the hybrid drying of apple slices decreased and energy efficiency of the drying system increased with increasing microwave power and air temperature. Apples can be dried rapidly and effectively by use of the hybrid technique.

Recovery of materials from waste printed circuit boards by vacuum pyrolysis and vacuum centrifugal separation.

PubMed

Zhou, Yihui; Wu, Wenbiao; Qiu, Keqiang

2010-11-01

In this research, a two-step process consisting of vacuum pyrolysis and vacuum centrifugal separation was employed to treat waste printed circuit boards (WPCBs). Firstly, WPCBs were pyrolysed under vacuum condition at 600 °C for 30 min in a lab-scale reactor. Then, the obtained pyrolysis residue was heated under vacuum until the solder was melted, and then the molten solder was separated from the pyrolysis residue by the centrifugal force. The results of vacuum pyrolysis showed that the type-A of WPCBs (the base plates of which was made from cellulose paper reinforced phenolic resin) pyrolysed to form an average of 67.97 wt.% residue, 27.73 wt.% oil, and 4.30 wt.% gas; and pyrolysis of the type-B of WPCBs (the base plates of which was made from glass fiber reinforced epoxy resin) led to an average mass balance of 72.20 wt.% residue, 21.45 wt.% oil, and 6.35 wt.% gas. The results of vacuum centrifugal separation showed that the separation of solder was complete when the pyrolysis residue was heated at 400 °C, and the rotating drum was rotated at 1200 rpm for 10 min. The pyrolysis oil and gas can be used as fuel or chemical feedstock after treatment. The pyrolysis residue after solder separation contained various metals, glass fibers and other inorganic materials, which could be recycled for further processing. The recovered solder can be reused directly and it can also be a good resource of lead and tin for refining. Copyright © 2010 Elsevier Ltd. All rights reserved.

Innovative application of the moisture analyzer for determination of dry mass content of processed cheese

NASA Astrophysics Data System (ADS)

Kowalska, Małgorzata; Janas, Sławomir; Woźniak, Magdalena

2018-04-01

The aim of this work was the presentation of an alternative method of determination of the total dry mass content in processed cheese. The authors claim that the presented method can be used in industry's quality control laboratories for routine testing and for quick in-process control. For the test purposes both reference method of determination of dry mass in processed cheese and moisture analyzer method were used. The tests were carried out for three different kinds of processed cheese. In accordance with the reference method, the sample was placed on a layer of silica sand and dried at the temperature of 102 °C for about 4 h. The moisture analyzer test required method validation, with regard to drying temperature range and mass of the analyzed sample. Optimum drying temperature of 110 °C was determined experimentally. For Hochland cream processed cheese sample, the total dry mass content, obtained using the reference method, was 38.92%, whereas using the moisture analyzer method, it was 38.74%. An average analysis time in case of the moisture analyzer method was 9 min. For the sample of processed cheese with tomatoes, the reference method result was 40.37%, and the alternative method result was 40.67%. For the sample of cream processed cheese with garlic the reference method gave value of 36.88%, and the alternative method, of 37.02%. An average time of those determinations was 16 min. Obtained results confirmed that use of moisture analyzer is effective. Compliant values of dry mass content were obtained for both of the used methods. According to the authors, the fact that the measurement took incomparably less time for moisture analyzer method, is a key criterion of in-process control and final quality control method selection.

High-resolution microscope for tip-enhanced optical processes in ultrahigh vacuum

NASA Astrophysics Data System (ADS)

Steidtner, Jens; Pettinger, Bruno

2007-10-01

An optical microscope based on tip-enhanced optical processes that can be used for studies on adsorbates as well as thin layers and nanostructures is presented. The microscope provides chemical and topographic informations with a resolution of a few nanometers and can be employed in ultrahigh vacuum as well as gas phase. The construction involves a number of improvements compared to conventional instruments. The central idea is to mount, within an UHV system, an optical platform with all necessary optical elements to a rigid frame that also carries the scanning tunneling microscope unit and to integrate a high numerical aperture parabolic mirror between the scanning probe microscope head and the sample. The parabolic mirror serves to focus the incident light and to collect a large fraction of the scattered light. The first experimental results of Raman measurements on silicon samples as well as brilliant cresyl blue layers on single crystalline gold and platinum surfaces in ultrahigh vacuum are presented. For dye adsorbates a Raman enhancement of ˜106 and a net signal gain of up to 4000 was observed. The focus diameter (˜λ/2) was measured by Raman imaging the focal region on a Si surface. The requirements of the parabolic mirror in terms of alignment accuracy were experimentally determined as well.

Vacuum status-display and sector-conditioning programs

NASA Astrophysics Data System (ADS)

Skelly, J.; Yen, S.

1990-08-01

Two programs have been developed for observation and control of the AGS vacuum system, which include the following notable features: (1) they incorporate a graphical user interface and (2) they are driven by a relational database which describes the vacuum system. The vacuum system comprises some 440 devices organized into 28 vacuum sectors. The status-display program invites menu selection of a sector, interrogates the relational database for relevant vacuum devices, acquires live readbacks and posts a graphical display of their status. The sector-conditioning program likewise invites sector selection, produces the same status display and also implements process control logic on the sector devices to pump the sector down from atmospheric pressure to high vacuum over a period extending several hours. As additional devices are installed in the vacuum system, the devices are added to the relational database; these programs then automatically include the new devices.

Optimization of a pharmaceutical freeze-dried product and its process using an experimental design approach and innovative process analyzers.

PubMed

De Beer, T R M; Wiggenhorn, M; Hawe, A; Kasper, J C; Almeida, A; Quinten, T; Friess, W; Winter, G; Vervaet, C; Remon, J P

2011-02-15

The aim of the present study was to examine the possibilities/advantages of using recently introduced in-line spectroscopic process analyzers (Raman, NIR and plasma emission spectroscopy), within well-designed experiments, for the optimization of a pharmaceutical formulation and its freeze-drying process. The formulation under investigation was a mannitol (crystalline bulking agent)-sucrose (lyo- and cryoprotector) excipient system. The effects of two formulation variables (mannitol/sucrose ratio and amount of NaCl) and three process variables (freezing rate, annealing temperature and secondary drying temperature) upon several critical process and product responses (onset and duration of ice crystallization, onset and duration of mannitol crystallization, duration of primary drying, residual moisture content and amount of mannitol hemi-hydrate in end product) were examined using a design of experiments (DOE) methodology. A 2-level fractional factorial design (2(5-1)=16 experiments+3 center points=19 experiments) was employed. All experiments were monitored in-line using Raman, NIR and plasma emission spectroscopy, which supply continuous process and product information during freeze-drying. Off-line X-ray powder diffraction analysis and Karl-Fisher titration were performed to determine the morphology and residual moisture content of the end product, respectively. In first instance, the results showed that - besides the previous described findings in De Beer et al., Anal. Chem. 81 (2009) 7639-7649 - Raman and NIR spectroscopy are able to monitor the product behavior throughout the complete annealing step during freeze-drying. The DOE approach allowed predicting the optimum combination of process and formulation parameters leading to the desired responses. Applying a mannitol/sucrose ratio of 4, without adding NaCl and processing the formulation without an annealing step, using a freezing rate of 0.9°C/min and a secondary drying temperature of 40°C resulted in

[Evaluation of the quality of poultry meat and its processing for vacuum packaging].

PubMed

Swiderski, F; Russel, S; Waszkiewicz-Robak, B; Cholewińska, E

1997-01-01

The aim of study was to evaluate the quality of poultry meat, roasted and smoked chicken and poultry pie packing under low and high vacuum. All investigated products were stored at +4 degrees C and evaluated by microbiological analysis. It was showed that packing under low and high vacuum inhibited development of aerobic microorganisms, proteolytic bacteria, yeasts and moulds. Vacuum-packaged storage of poultry meat and its products stimulated activity of anaerobic, nonsporeforming bacteria. The fast spoilage of fresh poultry meat was observed both under vacuum and conventional storage. The microbiology quality of poultry products depended on technology of production and microbiological quality of raw material.

In-line and real-time process monitoring of a freeze drying process using Raman and NIR spectroscopy as complementary process analytical technology (PAT) tools.

PubMed

De Beer, T R M; Vercruysse, P; Burggraeve, A; Quinten, T; Ouyang, J; Zhang, X; Vervaet, C; Remon, J P; Baeyens, W R G

2009-09-01

The aim of the present study was to examine the complementary properties of Raman and near infrared (NIR) spectroscopy as PAT tools for the fast, noninvasive, nondestructive and in-line process monitoring of a freeze drying process. Therefore, Raman and NIR probes were built in the freeze dryer chamber, allowing simultaneous process monitoring. A 5% (w/v) mannitol solution was used as model for freeze drying. Raman and NIR spectra were continuously collected during freeze drying (one Raman and NIR spectrum/min) and the spectra were analyzed using principal component analysis (PCA) and multivariate curve resolution (MCR). Raman spectroscopy was able to supply information about (i) the mannitol solid state throughout the entire process, (ii) the endpoint of freezing (endpoint of mannitol crystallization), and (iii) several physical and chemical phenomena occurring during the process (onset of ice nucleation, onset of mannitol crystallization). NIR spectroscopy proved to be a more sensitive tool to monitor the critical aspects during drying: (i) endpoint of ice sublimation and (ii) monitoring the release of hydrate water during storage. Furthermore, via NIR spectroscopy some Raman observations were confirmed: start of ice nucleation, end of mannitol crystallization and solid state characteristics of the end product. When Raman and NIR monitoring were performed on the same vial, the Raman signal was saturated during the freezing step caused by reflected NIR light reaching the Raman detector. Therefore, NIR and Raman measurements were done on a different vial. Also the importance of the position of the probes (Raman probe above the vial and NIR probe at the bottom of the sidewall of the vial) in order to obtain all required critical information is outlined. Combining Raman and NIR spectroscopy for the simultaneous monitoring of freeze drying allows monitoring almost all critical freeze drying process aspects. Both techniques do not only complement each other, they also

Simulation of the process kinetics and analysis of physicochemical properties in the freeze drying of kale

NASA Astrophysics Data System (ADS)

Dziki, Dariusz; Polak, Renata; Rudy, Stanisław; Krzykowski, Andrzej; Gawlik-Dziki, Urszula; Różyło, Renata; Miś, Antoni; Combrzyński, Maciej

2018-01-01

Investigations were performed to study the freeze-drying process of kale (Brassica oleracea L. var acephala). The process of freeze-drying was performed at temperatures of 20, 40, and 60°C for whole pieces of leaves and for pulped leaves. The kinetics of the freeze-drying of both kale leaves and kale pulp were best described by the Page model. The increasing freeze-drying temperature from 20 to 60°C induced an approximately two-fold decrease in the drying time. Freeze-drying significantly increased the value of the lightness, delta Chroma, and browning index of kale, and had little influence on the hue angle. The highest increase in the lightness and delta Chroma was observed for whole leaves freeze-dried at 20°C. An increase in the drying temperature brought about a slight decrease in the lightness, delta Chroma and the total colour difference. Pulping decreased the lightness and hue angle, and increased browning index. Freeze-drying engendered a slight decrease in the total phenolics content and antioxidant activity, in comparison to fresh leaves. The temperature of the process and pulping had little influence on the total phenolics content and antioxidant activity of dried kale, but significantly decreased the contents of chlorophyll a and chlorophyll b.

Automatic humidification system to support the assessment of food drying processes

NASA Astrophysics Data System (ADS)

Ortiz Hernández, B. D.; Carreño Olejua, A. R.; Castellanos Olarte, J. M.

2016-07-01

This work shows the main features of an automatic humidification system to provide drying air that match environmental conditions of different climate zones. This conditioned air is then used to assess the drying process of different agro-industrial products at the Automation and Control for Agro-industrial Processes Laboratory of the Pontifical Bolivarian University of Bucaramanga, Colombia. The automatic system allows creating and improving control strategies to supply drying air under specified conditions of temperature and humidity. The development of automatic routines to control and acquire real time data was made possible by the use of robust control systems and suitable instrumentation. The signals are read and directed to a controller memory where they are scaled and transferred to a memory unit. Using the IP address is possible to access data to perform supervision tasks. One important characteristic of this automatic system is the Dynamic Data Exchange Server (DDE) to allow direct communication between the control unit and the computer used to build experimental curves.

Infrared Thermography for Monitoring of Freeze-Drying Processes: Instrumental Developments and Preliminary Results

PubMed Central

Emteborg, Håkan; Zeleny, Reinhard; Charoud-Got, Jean; Martos, Gustavo; Lüddeke, Jörg; Schellin, Holger; Teipel, Katharina

2014-01-01

Coupling an infrared (IR) camera to a freeze dryer for on-line monitoring of freeze-drying cycles is described for the first time. Normally, product temperature is measured using a few invasive Pt-100 probes, resulting in poor spatial resolution. To overcome this, an IR camera was placed on a process-scale freeze dryer. Imaging took place every 120 s through a Germanium window comprising 30,000 measurement points obtained contact-free from −40°C to 25°C. Results are presented for an empty system, bulk drying of cheese slurry, and drying of 1 mL human serum in 150 vials. During freezing of the empty system, differences of more than 5°C were measured on the shelf. Adding a tray to the empty system, a difference of more than 8°C was observed. These temperature differences probably cause different ice structures affecting the drying speed during sublimation. A temperature difference of maximum 13°C was observed in bulk mode during sublimation. When drying in vials, differences of more than 10°C were observed. Gradually, the large temperature differences disappeared during secondary drying and products were transformed into uniformly dry cakes. The experimental data show that the IR camera is a highly versatile on-line monitoring tool for different kinds of freeze-drying processes. © 2014 European Union 103:2088–2097, 2014 PMID:24902839

Rapid formation of phase-clean 110 K (Bi-2223) powders derived via freeze-drying process

DOEpatents

Balachandran, Uthamalingam

1996-01-01

A process for the preparation of amorphous precursor powders for Pb-doped Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x (2223) includes a freeze-drying process incorporating a splat-freezing step. The process generally includes splat freezing a nitrate solution of Bi, Pb, Sr, Ca, and Cu to form flakes of the solution without any phase separation; grinding the frozen flakes to form a powder; freeze-drying the frozen powder; heating the dried powder to form a dry green precursor powders; denitrating the green-powders; heating the denitrated powders to form phase-clean Bi-2223 powders. The grain boundaries of the 2223 grains appear to be clean, leading to good intergrain contact between 2223 grains.

Rapid formation of phase-clean 110 K (Bi-2223) powders derived via freeze-drying process

DOEpatents

Balachandran, U.

1996-06-04

A process for the preparation of amorphous precursor powders for Pb-doped Bi{sub 2}Sr{sub 2} Ca{sub 2}Cu{sub 3}O{sub x} (2223) includes a freeze-drying process incorporating a splat-freezing step. The process generally includes splat freezing a nitrate solution of Bi, Pb, Sr, Ca, and Cu to form flakes of the solution without any phase separation; grinding the frozen flakes to form a powder; freeze-drying the frozen powder; heating the dried powder to form a dry green precursor powders; denitrating the green-powders; heating the denitrated powders to form phase-clean Bi-2223 powders. The grain boundaries of the 2223 grains appear to be clean, leading to good intergrain contact between 2223 grains. 11 figs.

Silicon crystal growth in vacuum

NASA Technical Reports Server (NTRS)

Khattak, C. P.; Schmid, F.

1982-01-01

The most developed process for silicon crystal growth is the Czochralski (CZ) method which was in production for over two decades. In an effort to reduce cost of single crystal silicon for photovoltaic applications, a directional solidification technique, Heat Exchanger Method (HEM), was adapted. Materials used in HEM and CZ furnaces are quite similar (heaters, crucibles, insulation, etc.). To eliminate the cost of high purity argon, it was intended to use vacuum operation in HEM. Two of the major problems encountered in vacuum processing of silicon are crucible decomposition and silicon carbide formation in the melt.

Application of exopolysaccharides to improve the performance of ceramic bodies in the unidirectional dry pressing process

NASA Astrophysics Data System (ADS)

Caneira, Inês; Machado-Moreira, Bernardino; Dionísio, Amélia; Godinho, Vasco; Neves, Orquídia; Dias, Diamantino; Saiz-Jimenez, Cesareo; Miller, Ana Z.

2015-04-01

Ceramic industry represents an important sector of economic activity in the European countries and involves complex and numerous manufacturing processes. The unidirectional dry pressing process includes milling and stirring of raw materials (mainly clay and talc minerals) in aqueous suspensions, followed by spray drying to remove excess water obtaining spray-dried powders further subjected to dry pressing process (conformation). However, spray-dried ceramic powders exhibit an important variability in their performance when subjected to the dry pressing process, particularly in the adhesion to the mold and mechanical strength, affecting the quality of the final conformed ceramic products. Therefore, several synthetic additives (deflocculants, antifoams, binders, lubricants and plasticizers) are introduced in the ceramic slips to achieve uniform and homogeneous pastes, conditioning their rheological properties. However, an important variability associated with the performance of the conformed products is still reported. Exopolysaccharides or Extracellular Polymeric Substances (EPS) are polymers excreted by living organisms, such as bacteria, fungi and algae, which may confer unique and potentially interesting properties with potential industrial uses, such as viscosity control, gelation, and flocculation. Polysaccharides, such as pullulan, gellan, carrageenan and xanthan have found a wide range of applications in food, pharmaceutical, petroleum, and in other industries. The aim of this study was the assessment of exopolysaccharides as natural additives to optimize the performance of spray-dried ceramic powders during the unidirectional dry pressing process, replacing the synthetic additives used in the ceramic production process. Six exopolysaccharides, namely pullulan, gellan, xanthan gum, κappa- and iota-carrageenan, and guar gum were tested in steatite-based spray-dried ceramic powders at different concentrations. Subsequently, these ceramic powders were

Effects of annealing on the physical properties of therapeutic proteins during freeze drying process.

PubMed

Lim, Jun Yeul; Lim, Dae Gon; Kim, Ki Hyun; Park, Sang-Koo; Jeong, Seong Hoon

2018-02-01

Effects of annealing steps during the freeze drying process on etanercept, model protein, were evaluated using various analytical methods. The annealing was introduced in three different ways depending on time and temperature. Residual water contents of dried cakes varied from 2.91% to 6.39% and decreased when the annealing step was adopted, suggesting that they are directly affected by the freeze drying methods Moreover, the samples were more homogenous when annealing was adopted. Transition temperatures of the excipients (sucrose, mannitol, and glycine) were dependent on the freeze drying steps. Size exclusion chromatography showed that monomer contents were high when annealing was adopted and also they decreased less after thermal storage at 60°C. Dynamic light scattering results exhibited that annealing can be helpful in inhibiting aggregation and that thermal storage of freeze-dried samples preferably induced fragmentation over aggregation. Shift of circular dichroism spectrum and of the contents of etanercept secondary structure was observed with different freeze drying steps and thermal storage conditions. All analytical results suggest that the physicochemical properties of etanercept formulation can differ in response to different freeze drying steps and that annealing is beneficial for maintaining stability of protein and reducing the time of freeze drying process. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of Vacuum Properties on Electroweak Processes - A Theoretical Interpretation of Experiments

NASA Astrophysics Data System (ADS)

Stumpf, Harald

2008-06-01

Recently for discharges in fluids induced nuclear transmutations have been observed. It is our hypothesis that these reactions are due to a symmetry breaking of the electroweak vacuum by the experimental arrangement. The treatment of this hypothesis is based on the assumption that electroweak bosons, leptons and quarks possess a substructure of elementary fermionic constituents. The dynamical law of these fermionic constituents is given by a relativistically invariant nonlinear spinor field equation with local interaction, canonical quantization, selfregularization and probability interpretation. Phenomenological quantities of electroweak processes follow from the derivation of corresponding effective theories obtained by algebraic weak mapping theorems where the latter theories depend on the spinor field propagator, i. e. a vacuum expectation value. This propagator and its equation are studied for conserved and for broken discrete symmetries. For combined CP- and isospin symmetry breaking it is shown that the propagator corresponds to the experimental arrangements under consideration. The modifications of the effective electroweak theory due to this modified propagator are discussed. Based on these results a mechanism is sketched which offers a qualitative interpretation of the appearance of induced nuclear transmutations. A numerical estimate of electron capture is given.

Effect of different drying methods on chemical composition and bioactivity of tea polysaccharides.

PubMed

Wang, Yuanfeng; Liu, Yangyang; Huo, Jianglei; Zhaoa, Xintong; Zhao, Tingtong; Zheng, Jian; Ren, Jian; Wei, Xinlin

2013-11-01

Four polysaccharides (TPS-F, TPS-V, TPS-S and TPS-M) were obtained from tea (Camellia sinensis) leaves by freeze-drying, vacuum-drying, spray-drying and microwave-vacuum drying, respectively. Their chemical composition and biological properties were comparatively studied. The results showed these TPS were similar in IR, UV absorption and distribution of molecular weight. However, they showed significant differences (P<0.05) in yields of crude polysaccharides and contents of protein and total polyphenols. Furthermore, morphological analysis showed their surface differed from each other in size and shape when viewed by SEM, from which surface of TPS-F was rough and porous, surface of TPS-S was evenly particles, and surfaces of the other two were similar to anomalistic bricks. In addition, the bioactivity of them was also evaluated. It was found TPS-F exhibited relatively better ability on metal chelating and superoxide radicals scavenging assays than others, and TPS-V exhibited higher ability on α-glycosidase and α-amylase inhibition assays than others with inhibitory percentages of 82.75% and 92.8%. Copyright © 2013 Elsevier B.V. All rights reserved.

Fabrication process analysis and experimental verification for aluminum bipolar plates in fuel cells by vacuum die-casting

NASA Astrophysics Data System (ADS)

Jin, Chul Kyu; Kang, Chung Gil

2011-10-01

There are various methods for the fabrication of bipolar plates, but these are still limited to machining and stamping processes. High-pressure die casting (HPDC) is an ideal process for the manufacture of bipolar plates This study aims to investigate the formability of bipolar plates for polymer electrolyte membrane fuel cells (PEMFCs) fabricated by vacuum HPDC of an Al-Mg alloy (ALDC6). The cavity of the mold consisted of a thin-walled plate (200 mm × 200 mm × 0.8 mm) with a layer of serpentine channel (50 mm × 50 mm). The location and direction of the channel in the final mold design was determined by computational simulation (MAGMA soft). In addition, simulation results for different conditions of plunger stroke control were compared to those from actual die-casting experiments. Under a vacuum pressure of 35 kPa and for injection speeds of 0.3 and 2.5 m s-1 in the low and high speed regions, respectively, the samples had few casting defects. In addition, the hardness was higher and porosity in microstructure was less than those of the samples made under other injection speed conditions. In case of thin-walled plates, vacuum die casting is beneficial in terms of formability compared to conventional die casting.

Vacuum-deposited polymer/silver reflector material

NASA Astrophysics Data System (ADS)

Affinito, John D.; Martin, Peter M.; Gross, Mark E.; Bennett, Wendy D.

1994-09-01

Weatherable, low cost, front surface, solar reflectors on flexible substrates would be highly desirable for lamination to solar concentrator panels. The method to be described in this paper may permit such reflector material to be fabricated for less the 50$CNT per square foot. Vacuum deposited Polymer/Silver/Polymer reflectors and Fabry-Perot interference filters were fabricated in a vacuum web coating operation on polyester substrates. Reflectivities were measured in the wavelength range from .4 micrometers to .8 micrometers . It is hoped that a low cost substrate can be used with the substrate laminated to the concentrator and the weatherable acrylic polymer coating facing the sun. This technique should be capable of deposition line speeds approaching 1500 linear feet/minute2. Central to this technique is a new vacuum deposition process for the high rate deposition of polymer films. This polymer process involves the flash evaporation of an acrylic monomer onto a moving substrate. The monomer is subsequently cured by an electron beam or ultraviolet light. This high speed polymer film deposition process has been named the PML process- for Polymer Multi- Layer.

Short Term Preservation of Hide Using Vacuum: Influence on Properties of Hide and of Processed Leather

PubMed Central

Gudro, Ilze; Valeika, Virgilijus; Sirvaitytė, Justa

2014-01-01

The objective of this work was to investigate vacuum influence on hide preservation time and how it affects hide structure. It was established that vacuum prolongs the storage time without hide tissue putrefaction up to 21 days when the storage temperature is 4°C. The microorganisms act for all storage times, but the action is weak and has no observable influence on the quality of hide during the time period mentioned. The hide shrinkage temperature decrease is negligible, which shows that breaking of intermolecular bonds does not occur. Optical microscopy, infrared spectroscopy and differential scanning calorimetry also did not show any structural changes which can influence the quality of leather produced from such hide. The qualitative indexes of wet blue processed under laboratory conditions and of leather produced during industrial trials are presented. Indexes such as chromium compounds exhaustion, content of chromium in leather, content of soluble matter in dichloromethane, strength properties, and shrinkage temperature were determined. Properties of the leather produced from vacuumed hide under industrial conditions conformed to the requirements of shoe upper leather. PMID:25393637

Process simulation of modified dry grind ethanol plant with recycle of pretreated and enzymatically hydrolyzed distillers' grains.

PubMed

Kim, Youngmi; Mosier, Nathan; Ladisch, Michael R

2008-08-01

Distillers' grains (DG), a co-product of a dry grind ethanol process, is an excellent source of supplemental proteins in livestock feed. Studies have shown that, due to its high polymeric sugar contents and ease of hydrolysis, the distillers' grains have potential as an additional source of fermentable sugars for ethanol fermentation. The benefit of processing the distillers' grains to extract fermentable sugars lies in an increased ethanol yield without significant modification in the current dry grind technology. Three different potential configurations of process alternatives in which pretreated and hydrolyzed distillers' grains are recycled for an enhanced overall ethanol yield are proposed and discussed in this paper based on the liquid hot water (LHW) pretreatment of distillers' grains. Possible limitations of each proposed process are also discussed. This paper presents a compositional analysis of distillers' grains, as well as a simulation of the modified dry grind processes with recycle of distillers' grains. Simulated material balances for the modified dry grind processes are established based on the base case assumptions. These balances are compared to the conventional dry grind process in terms of ethanol yield, compositions of its co-products, and accumulation of fermentation inhibitors. Results show that 14% higher ethanol yield is achievable by processing and hydrolyzing the distillers' grains for additional fermentable sugars, as compared to the conventional dry grind process. Accumulation of fermentation by-products and inhibitory components in the proposed process is predicted to be 2-5 times higher than in the conventional dry grind process. The impact of fermentation inhibitors is reviewed and discussed. The final eDDGS (enhanced dried distillers' grains) from the modified processes has 30-40% greater protein content per mass than DDGS, and its potential as a value-added process is also analyzed. While the case studies used to illustrate the

Physicochemical characterization of nopal pads (Opuntia ficus indica) and dry vacuum nopal powders as a function of the maturation.

PubMed

Rodríguez-Garcia, M E; de Lira, C; Hernández-Becerra, E; Cornejo-Villegas, M A; Palacios-Fonseca, A J; Rojas-Molina, I; Reynoso, R; Quintero, L C; Del-Real, A; Zepeda, T A; Muñoz-Torres, C

2007-09-01

This paper presents the physicochemical and nutrimental characterization of fresh nopal (Opuntia ficus indica, Redonda variety) and nopal powder produced at different stages of development. Nopal powder was obtained by dry vacuum technique using 10(2) Torr and low temperature (40 degrees C). The results showed that the nutrimental and mineral composition of nopal changes as a function of the maturation as follow: The ash content increases from 18.41 for nopalitos (60 g of weight) to 23.24% (nopal pads 200 g); calcium content increases from 1.52 to 3.72%, while phosphorous exhibits an opposite trend: 0.43 to 0.27%, respectively. Calcium oxalate was determined by X-ray diffraction and SEM microscopy and quantified by using atomic absorption spectroscopy. Calcium oxalate decreases from 7.95 to 3.47 mg/g and the Ca/P ratio varies from 3.6 to 11. The soluble fibre decreases from 25.22 to 14.91%, while insoluble fibre increases from 29.87 to 41.65%. These results suggest that nopal could be an important source of minerals within the diets of people in Mexico and the rest of Latin America.

Indian Vacuum Society: The Indian Vacuum Society

NASA Astrophysics Data System (ADS)

Saha, T. K.

2008-03-01

The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of

Food drying process by power ultrasound.

PubMed

de la Fuente-Blanco, S; Riera-Franco de Sarabia, E; Acosta-Aparicio, V M; Blanco-Blanco, A; Gallego-Juárez, J A

2006-12-22

Drying processes, which have a great significance in the food industry, are frequently based on the use of thermal energy. Nevertheless, such methods may produce structural changes in the products. Consequently, a great emphasis is presently given to novel treatments where the quality will be preserved. Such is the case of the application of high-power ultrasound which represents an emergent and promising technology. During the last few years, we have been involved in the development of an ultrasonic dehydration process, based on the application of the ultrasonic vibration in direct contact with the product. Such a process has been the object of a detailed study at laboratory stage on the influence of the different parameters involved. This paper deals with the development and testing of a prototype system for the application and evaluation of the process at a pre-industrial stage. Such prototype is based on a high-power rectangular plate transducer, working at a frequency of 20 kHz, with a power capacity of about 100 W. In order to study mechanical and thermal effects, the system is provided with a series of sensors which permit monitoring the parameters of the process. Specific software has also been developed to facilitate data collection and analysis. The system has been tested with vegetable samples.

Vapor Hydrogen Peroxide as Alternative to Dry Heat Microbial Reduction

NASA Technical Reports Server (NTRS)

Cash, Howard A.; Kern, Roger G.; Chung, Shirley Y.; Koukol, Robert C.; Barengoltz, Jack B.

2006-01-01

The Jet Propulsion Laboratory, in conjunction with the NASA Planetary Protection Officer, has selected vapor phase hydrogen peroxide (VHP) sterilization process for continued development as a NASA approved sterilization technique for spacecraft subsystems and systems. The goal is to include this technique, with appropriate specification, in NPG8020.12C as a low temperature complementary technique to the dry heat sterilization process. A series of experiments were conducted in vacuum to determine VHP process parameters that provided significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. With this knowledge of D values, sensible margins can be applied in a planetary protection specification. The outcome of this study provided an optimization of test sterilizer process conditions: VHP concentration, process duration, a process temperature range for which the worst case D value may be imposed, a process humidity range for which the worst case D value may be imposed, and robustness to selected spacecraft material substrates.

A Design of Experiment approach to predict product and process parameters for a spray dried influenza vaccine.

PubMed

Kanojia, Gaurav; Willems, Geert-Jan; Frijlink, Henderik W; Kersten, Gideon F A; Soema, Peter C; Amorij, Jean-Pierre

2016-09-25

Spray dried vaccine formulations might be an alternative to traditional lyophilized vaccines. Compared to lyophilization, spray drying is a fast and cheap process extensively used for drying biologicals. The current study provides an approach that utilizes Design of Experiments for spray drying process to stabilize whole inactivated influenza virus (WIV) vaccine. The approach included systematically screening and optimizing the spray drying process variables, determining the desired process parameters and predicting product quality parameters. The process parameters inlet air temperature, nozzle gas flow rate and feed flow rate and their effect on WIV vaccine powder characteristics such as particle size, residual moisture content (RMC) and powder yield were investigated. Vaccine powders with a broad range of physical characteristics (RMC 1.2-4.9%, particle size 2.4-8.5μm and powder yield 42-82%) were obtained. WIV showed no significant loss in antigenicity as revealed by hemagglutination test. Furthermore, descriptive models generated by DoE software could be used to determine and select (set) spray drying process parameter. This was used to generate a dried WIV powder with predefined (predicted) characteristics. Moreover, the spray dried vaccine powders retained their antigenic stability even after storage for 3 months at 60°C. The approach used here enabled the generation of a thermostable, antigenic WIV vaccine powder with desired physical characteristics that could be potentially used for pulmonary administration. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Butt Welding Joint of Aluminum Alloy by Space GHTA Welding Process in Vacuum

NASA Astrophysics Data System (ADS)

Suita, Yoshikazu; Shinike, Shuhei; Ekuni, Tomohide; Terajima, Noboru; Tsukuda, Yoshiyuki; Imagawa, Kichiro

Aluminum alloys have been used widely in constructing various space structures including the International Space Station (ISS) and launch vehicles. For space applications, welding experiments on aluminum alloy were performed using the GHTA (Gas Hollow Tungsten Arc) welding process using a filler wire feeder in a vacuum. We investigated the melting phenomenon of the base metal and filler wire, bead formation, and the effects of wire feed speed on melting characteristics. The melting mechanism in the base metal during the bead on a plate with wire feed was similar to that for the melt run without wire feed. We clarified the effects of wire feed speed on bead sizes and configurations. Furthermore, the butt welded joint welded using the optimum wire feed speed, and the joint tensile strengths were evaluated. The tensile strength of the square butt joint welded by the pulsed DC GHTA welding with wire feed in a vacuum is nearly equal to that of the same joint welded by conventional GTA (Gas Tungsten Arc) welding in air.

Fiber Bragg grating sensor to monitor stress kinetics in drying process of commercial latex paints.

PubMed

de Lourenço, Ivo; Possetti, Gustavo R C; Muller, Marcia; Fabris, José L

2010-01-01

In this paper, we report a study about the application of packaged fiber Bragg gratings used as strain sensors to monitor the stress kinetics during the drying process of commercial latex paints. Three stages of drying with distinct mechanical deformation and temporal behaviors were identified for the samples, with mechanical deformation from 15 μm to 21 μm in the longitudinal film dimension on time intervals from 370 to 600 minutes. Drying time tests based on human sense technique described by the Brazilian Technical Standards NBR 9558 were also done. The results obtained shows that human sense technique has a limited perception of the drying process and that the optical measurement system proposed can be used to characterize correctly the dry-through stage of paint. The influence of solvent (water) addition in the drying process was also investigated. The paint was diluted with four parts paint and one part water (80% paint), and one part paint and one part water (50% paint). It was observed that the increase of the water ratio mixed into the paint decreases both the mechanical deformation magnitude and the paint dry-through time. Contraction of 5.2 μm and 10.4 μm were measured for concentrations of 50% and 80% of paint in the mixture, respectively. For both diluted paints the dry-through time was approximately 170 minutes less than undiluted paint. The optical technique proposed in this work can contribute to the development of new standards to specify the drying time of paint coatings.

Fiber Bragg Grating Sensor to Monitor Stress Kinetics in Drying Process of Commercial Latex Paints

PubMed Central

de Lourenço, Ivo; Possetti, Gustavo R. C.; Muller, Marcia; Fabris, José L.

2010-01-01

In this paper, we report a study about the application of packaged fiber Bragg gratings used as strain sensors to monitor the stress kinetics during the drying process of commercial latex paints. Three stages of drying with distinct mechanical deformation and temporal behaviors were identified for the samples, with mechanical deformation from 15 μm to 21 μm in the longitudinal film dimension on time intervals from 370 to 600 minutes. Drying time tests based on human sense technique described by the Brazilian Technical Standards NBR 9558 were also done. The results obtained shows that human sense technique has a limited perception of the drying process and that the optical measurement system proposed can be used to characterize correctly the dry-through stage of paint. The influence of solvent (water) addition in the drying process was also investigated. The paint was diluted with four parts paint and one part water (80% paint), and one part paint and one part water (50% paint). It was observed that the increase of the water ratio mixed into the paint decreases both the mechanical deformation magnitude and the paint dry-through time. Contraction of 5.2 μm and 10.4 μm were measured for concentrations of 50% and 80% of paint in the mixture, respectively. For both diluted paints the dry-through time was approximately 170 minutes less than undiluted paint. The optical technique proposed in this work can contribute to the development of new standards to specify the drying time of paint coatings. PMID:22399906

Energy-efficient regenerative liquid desiccant drying process

DOEpatents

Ko, Suk M.; Grodzka, Philomena G.; McCormick, Paul O.

1980-01-01

This invention relates to the use of desiccants in conjunction with an open oop drying cycle and a closed loop drying cycle to reclaim the energy expended in vaporizing moisture in harvested crops. In the closed loop cycle, the drying air is brought into contact with a desiccant after it exits the crop drying bin. Water vapor in the moist air is absorbed by the desiccant, thus reducing the relative humidity of the air. The air is then heated by the used desiccant and returned to the crop bin. During the open loop drying cycle the used desiccant is heated (either fossil or solar energy heat sources may be used) and regenerated at high temperature, driving water vapor from the desiccant. This water vapor is condensed and used to preheat the dilute (wet) desiccant before heat is added from the external source (fossil or solar). The latent heat of vaporization of the moisture removed from the desiccant is reclaimed in this manner. The sensible heat of the regenerated desiccant is utilized in the open loop drying cycle. Also, closed cycle operation implies that no net energy is expended in heating drying air.

Method of drying passivated micromachines by dewetting from a liquid-based process

DOEpatents

Houston, Michael R.; Howe, Roger T.; Maboudian, Roya; Srinivasan, Uthara

2000-01-01

A method of fabricating a micromachine includes the step of constructing a low surface energy film on the micromachine. The micromachine is then rinsed with a rinse liquid that has a high surface energy, relative to the low surface energy film, to produce a contact angle of greater than 90.degree. between the low surface energy film and the rinse liquid. This relatively large contact angle causes any rinse liquid on the micromachine to be displaced from the micromachine when the micromachine is removed from the rinse liquid. In other words, the micromachine is dried by dewetting from a liquid-based process. Thus, a separate evaporative drying step is not required, as the micromachine is removed from the liquid-based process in a dry state. The relatively large contact angle also operates to prevent attractive capillary forces between micromachine components, thereby preventing contact and adhesion between adjacent microstructure surfaces. The low surface energy film may be constructed with a fluorinated self-assembled monolayer film. The processing of the invention avoids the use of environmentally harmful, health-hazardous chemicals.

Study of a dry room in a battery manufacturing plant using a process model

NASA Astrophysics Data System (ADS)

Ahmed, Shabbir; Nelson, Paul A.; Dees, Dennis W.

2016-09-01

The manufacture of lithium ion batteries requires some processing steps to be carried out in a dry room, where the moisture content should remain below 100 parts per million. The design and operation of such a dry room adds to the cost of the battery. This paper studied the humidity management of the air to and from the dry room to understand the impact of design and operating parameters on the energy demand and the cost contribution towards the battery manufacturing cost. The study was conducted with the help of a process model for a dry room with a volume of 16,000 cubic meters. For a defined base case scenario it was found that the dry room operation has an energy demand of approximately 400 kW. The paper explores some tradeoffs in design and operating parameters by looking at the humidity reduction by quenching the make-up air vs. at the desiccant wheel, and the impact of the heat recovery from the desiccant regeneration cycle.

Characteristics and functionality of appetite-reducing thylakoid powders produced by three different drying processes.

PubMed

Östbring, Karolina; Sjöholm, Ingegerd; Sörenson, Henrietta; Ekholm, Andrej; Erlanson-Albertsson, Charlotte; Rayner, Marilyn

2018-03-01

Thylakoids, a chloroplast membrane extracted from green leaves, are a promising functional ingredient with appetite-reducing properties via their lipase-inhibiting effect. Thylakoids in powder form have been evaluated in animal and human models, but no comprehensive study has been conducted on powder characteristics. The aim was to investigate the effects of different isolation methods and drying techniques (drum-drying, spray-drying, freeze-drying) on thylakoids' physicochemical and functional properties. Freeze-drying yielded thylakoid powders with the highest lipase-inhibiting capacity. We hypothesize that the specific macromolecular structures involved in lipase inhibition were degraded to different degrees by exposure to heat during spray-drying and drum-drying. We identified lightness (Hunter's L-value), greenness (Hunter's a-value), chlorophyll content and emulsifying capacity to be correlated to lipase-inhibiting capacity. Thus, to optimize the thylakoids functional properties, the internal membrane structure indicated by retained green colour should be preserved. This opens possibilities to use chlorophyll content as a marker for thylakoid functionality in screening processes during process optimization. Thylakoids are heat sensitive, and a mild drying technique should be used in industrial production. Strong links between physicochemical parameters and lipase inhibition capacity were found that can be used to predict functionality. The approach from this study can be applied towards production of standardized high-quality functional food ingredients. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Radiolytic and Thermal Process Relevant to Dry Storage of Spent Nuclear Fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marschman, Steven C.; Haustein, Peter E.; Madey, Theodore E.

1999-06-01

This project involves basic research in chemistry and physics aimed at providing information pertinent to the safe long-term dry storage of spent nuclear fuel (SNF), thousands of tons of which remain in water storage across the DOE complex. The Hanford Site K-Basins alone hold 2300 tons of spent fuel, much of it severely corroded, and similar situations exist at Savannah River and Idaho National Engineering and Environmental Laboratory. DOE plans to remove this fuel and seal it in overpack canisters for ''dry'' interim storage for up to 75 years while awaiting permanent disposition. Chemically bound water will remain in thismore » fuel even after the proposed drying steps, leading to possible long-term corrosion of the containers and/or fuel rods themselves, generation of H2 and O2 gas via radiolysis (which could lead to deflagration or detonation), and reactions of pyrophoric uranium hydrides. No thoroughly tested model is now available to predict fuel behavior during preprocessing, processing, or storage. In a collaborative effort among Rutgers University, Pacific Northwest National Laboratory, and Brookhaven National Laboratory, we are studying the radiolytic reaction, drying processes, and corrosion behavior of actual SNF materials and of pure and mixed-phase samples. We propose to determine what is omitted from current models: radiolysis of water adsorbed on or in hydrates or hydroxides, thermodynamics of interfacial phases, and kinetics of drying. A model will be developed and tested against actual fuel rod behavior to ensure validity and applicability to the problems associated with developing dry storage strategies for DOE-owned SNF.« less

Internal motion in high vacuum systems

NASA Astrophysics Data System (ADS)

Frank, J. M.

Three transfer and positioning mechanisms have been developed for the non-air exposed, multistep processing of components in vacuum chambers. The functions to be performed in all of the systems include ultraviolet/ozone cleaning, vacuum baking, deposition of thin films, and thermocompression sealing of the enclosures. Precise positioning of the components is required during the evaporation and sealing processes. The three methods of transporting and positioning the components were developed to accommodate the design criteria and goals of each individual system. The design philosophy, goals, and operation of the three mechanisms are discussed.

Utilization of optical emission endpoint in photomask dry etch processing

NASA Astrophysics Data System (ADS)

Faure, Thomas B.; Huynh, Cuc; Lercel, Michael J.; Smith, Adam; Wagner, Thomas

2002-03-01

Use of accurate and repeatable endpoint detection during dry etch processing of photomask is very important for obtaining good mask mean-to-target and CD uniformity performance. It was found that the typical laser reflectivity endpoint detecting system used on photomask dry etch systems had several key limitations that caused unnecessary scrap and non-optimum image size performance. Consequently, work to develop and implement use of a more robust optical emission endpoint detection system for chrome dry etch processing of photomask was performed. Initial feasibility studies showed that the emission technique was sensitive enough to monitor pattern loadings on contact and via level masks down to 3 percent pattern coverage. Additional work was performed to further improve this to 1 percent pattern coverage by optimizing the endpoint detection parameters. Comparison studies of mask mean-to-target performance and CD uniformity were performed with the use of optical emission endpoint versus laser endpoint for masks built using TOK IP3600 and ZEP 7000 resist systems. It was found that an improvement in mean-to-target performance and CD uniformity was realized on several types of production masks. In addition, part-to-part endpoint time repeatability was found to be significantly improved with the use of optical emission endpoint.

Biogenic amine profile in unripe Arabica coffee beans processed according to dry and wet methods.

PubMed

Dias, Eduardo C; Pereira, Rosemary G F A; Borém, Flávio M; Mendes, Eulália; de Lima, Renato R; Fernandes, José O; Casal, Susana

2012-04-25

Immature coffee fruit processing contributes to a high amount of defective beans, which determines a significant amount of low-quality coffee sold in the Brazilian internal market. Unripe bean processing was tested, taking the levels of bioactive amines as criteria for evaluating the extent of fermentation and establishing the differences between processing methods. The beans were processed by the dry method after being mechanically depulped immediately after harvest or after a 12 h resting period in a dry pile or immersed in water. Seven bioactive amines were quantified: putrescine, spermine, spermidine, serotonin, cadaverine, histamine, and tyramine, with global amounts ranging from 71.8 to 80.3 mg/kg. The levels of spermine and spermidine were lower in the unripe depulped coffee than in the natural coffee. The specific conditions of dry and wet processing also influenced cadaverine levels, and histamine was reduced in unripe depulped coffee. A resting period of 12 h does not induce significant alteration on the beans and can be improved if performed in water. These results confirm that peeling immature coffee can decrease fermentation processes while providing more uniform drying, thus reducing the number of defects and potentially increasing beverage quality.

Generation of a medium vacuum pressure by using two different pumping methods in the KRISS dynamic flow-control system

NASA Astrophysics Data System (ADS)

Hong, S. S.; Lim, J. Y.; Khan, W.

2014-02-01

Pumping systems with large vacuum chambers have numerous applications in the process industry: for example, mixing of various types of gases as in the semiconductor industry, the calibration of vacuum gauges, the measurement of outgassing rates of various materials in the field of space technology, etc. Most often, these systems are used in the medium vacuum range (10-1 Pa-102 Pa) and in the dynamically-generated pressure mode. We have designed and developed a new dynamic flow system at the KRISS (Korea Research Institute of Standards and Science) that can be used for such applications with reliability in the range from 0.1 Pa - 133 Pa. In this report, the design philosophy, operational procedure and experimental data for the generated stable pressure points in the chamber of the system are discussed. The data consist the pressure points generated in the medium vacuum range while pumping the chamber of the system by using two different methods: first by using a dry scroll pump and then by using a combination of a turbomolecular pump backed by the same scroll pump. The relative standard deviations in the pressure points were calculated and were found to be greater than 1.5% for the scroll pump and less than 0.5% for the turbomolecular pump.

Effects of drying processes on starch-related physicochemical properties, bioactive components and antioxidant properties of yam flours.

PubMed

Chen, Xuetao; Li, Xia; Mao, Xinhui; Huang, Hanhan; Wang, Tingting; Qu, Zhuo; Miao, Jing; Gao, Wenyuan

2017-06-01

The effects of five different drying processes, air drying (AD), sulphur fumigation drying (SFD), hot air drying (HAD), freeze drying (FD) and microwave drying (MWD) for yams in terms of starch-related properties and antioxidant activity were studied. From the results of scanning electron microscopy (SEM), polarized optical microscopy (POM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR), the MWD sample was found to contain gelatinized starch granules. The FD yam had more slow digestible (SDS) and resistant starches (RS) compared with those processed with other modern drying methods. The bioactive components and the reducing power of the dried yams, were lower than those of fresh yam. When five dried samples were compared by principal component analysis, the HAD and SFD samples were observed to have the highest comprehensive principal component values. Based on our results, HAD would be a better method for yam drying than the more traditional SFD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Treatment of a waste oil-in-water emulsion from a copper-rolling process by ultrafiltration and vacuum evaporation.

PubMed

Gutiérrez, Gemma; Lobo, Alberto; Benito, José M; Coca, José; Pazos, Carmen

2011-01-30

A process is proposed for the treatment of a waste oil-in-water (O/W) emulsion generated in an industrial copper-rolling operation. The use of demulsifier agents improves the subsequent treatment by techniques such as ultrafiltration (UF) or evaporation. The effluent COD is reduced up to 50% when the O/W emulsion is treated by UF using a flat 30 nm TiO(2) ceramic membrane (ΔP = 0.1 MPa) and up to 70% when it is treated by vacuum evaporation, after an emulsion destabilization pretreatment in both cases. Increases in the UF permeate flux and in the evaporation rate are observed when a chemical demulsifier is used in the pretreatment step. A combined process consisting of destabilization/settling, UF, and vacuum evaporation can yield a very high-quality aqueous effluent that could be used for process cooling or emulsion reformulation. Copyright © 2010 Elsevier B.V. All rights reserved.

Flow and Compaction During the Vacuum Assisted Resin Transfer Molding Process

NASA Technical Reports Server (NTRS)

Grimsley, Brian W.; Hubert, Pascal; Song, Xiao-Lan; Cano, Roberto J.; Loos, Alfred C.; Pipes, R. Byron

2001-01-01

The flow of an epoxy resin and compaction behavior of carbon fiber preform during vacuum- assisted resin transfer molding (VARTM) infiltration was measured using an instrumented tool. Composite panels were fabricated by the VARTM process using SAERTEX(R)2 multi-axial non- crimp carbon fiber fabric and the A.T.A.R.D. SI-ZG-5A epoxy resin. Resin pressure and preform thickness variation was measured during infiltration. The effects of the resin on the compaction behavior of the preform were measured. The local preform compaction during the infiltration is a combination of wetting and spring-back deformations. Flow front position computed by the 3DINFIL model was compared with the experimental data.

[Effect of gas-turbine green discoloring and drying processing methods on herbal quality of tetraploid Lonicerae Japonicae Flos].

PubMed

Hu, Xuan; Li, Wei-dong; Li, Ou; Hao, Jiang-bo; Liu, Jia-kun

2012-09-01

To study the effect of gas-turbine green discoloring and drying processing method on the quality of various Lonicerae Japonicae Flos herbs. DIKMA DiamonsilTM-C18 column (4.6 mm x 250 mm, 5 microm) was adopted using HPLC Waters 1525 and eluted with acetonitrile and 0.1% phosphate acid as the mobile phase. The flow rate was 1.0 mL x min(-1) , the column temperature was 25 degrees C the detection wavelength was 355 nm. After being processed by the gas-turbine green discoloring and drying method, tetraploid Lonicerae Japonicae Flos showed a green color. The contents of chlorogenic acid and galuteolin were 5.31% and 0.105% , both significantly higher by 18.0% and 32.1% than those of diploid Lonicerae Japonicae Flos processed by the same method. The content of chlorogenic acid in tetraploid Lonicerae Japonicae Flos processed the gas-turbine green discoloring and drying method were also remarkably higher than that of tetraploid and diploid Lonicerae Japonicae Flos processed by traditional processing method of natural drying. The gas-turbine green discoloring and drying processing method is a new-type drying method suitable for tetraploid Lonicerae Japonicae Flos. Under the condition of gas-turbine green discoloring and drying processing, tetraploid Lonicerae Japonicae Flos shows much higher quality than Lonicerae Japonicae Flos, suggesting that it is a good variety worth popularizing and applying.

Vacuum-Induction, Vacuum-Arc, and Air-Induction Melting of a Complex Heat-Resistant Alloy

NASA Technical Reports Server (NTRS)

Decker, R. F.; Rowe, John P.; Freeman, J. W.

1959-01-01

The relative hot-workability and creep-rupture properties at 1600 F of a complex 55Ni-20Cr-15Co-4Mo-3Ti-3Al alloy were evaluated for vacuum-induction, vacuum-arc, and air-induction melting. A limited study of the role of oxygen and nitrogen and the structural effects in the alloy associated with the melting process was carried out. The results showed that the level of boron and/or zirconium was far more influential on properties than the melting method. Vacuum melting did reduce corner cracking and improve surface during hot-rolling. It also resulted in more uniform properties within heats. The creep-rupture properties were slightly superior in vacuum heats at low boron plus zirconium or in heats with zirconium. There was little advantage at high boron levels and air heats were superior at high levels of boron plus zirconium. Vacuum heats also had fewer oxide and carbonitride inclusions although this was a function of the opportunity for separation of the inclusions from high oxygen plus nitrogen heats. The removal of phosphorous by vacuum melting was not found to be related to properties. Oxygen plus nitrogen appeared to increase ductility in creep-rupture tests suggesting that vacuum melting removes unidentified elements detrimental to ductility. Oxides and carbonitrides in themselves did not initiate microcracks. Carbonitrides in the grain boundaries of air heats did initiate microcracks. The role of microcracking from this source and as a function of oxygen and nitrogen content was not clear. Oxygen and nitrogen did intensify corner cracking during hot-rolling but were not responsible for poor surface which resulted from rolling heats melted in air.

Superconducting Vacuum-Gap Crossovers for High Performance Microwave Applications

NASA Technical Reports Server (NTRS)

Denis, Kevin L.; Brown, Ari D.; Chang, Meng-Ping; Hu, Ron; U-Yen, Kongpop; Wollack, Edward J.

2016-01-01

The design and fabrication of low-loss wide-bandwidth superconducting vacuum-gap crossovers for high performance millimeter wave applications are described. In order to reduce ohmic and parasitic losses at millimeter wavelengths a vacuum gap is preferred relative to dielectric spacer. Here, vacuum-gap crossovers were realized by using a sacrificial polymer layer followed by niobium sputter deposition optimized for coating coverage over an underlying niobium signal layer. Both coplanar waveguide and microstrip crossover topologies have been explored in detail. The resulting fabrication process is compatible with a bulk micro-machining process for realizing waveguide coupled detectors, which includes sacrificial wax bonding, and wafer backside deep reactive ion etching for creation of leg isolated silicon membrane structures. Release of the vacuum gap structures along with the wax bonded wafer after DRIE is implemented in the same process step used to complete the detector fabrication. ?

High-conversion hydrolysates and corn sweetener production in dry-grind corn process.

USDA-ARS?s Scientific Manuscript database

Most corn is processed to fuel ethanol and distillers’ grain animal feed using the dry grind process. However, wet milling is needed to refine corn starch. Corn starch is in turn processed to numerous products, including glucose and syrup. However, wet milling is a capital, labor, and energy intensi...

Processes of heat and mass transfer in straw bales using flue gasses as a drying medium

NASA Astrophysics Data System (ADS)

Goryl, Wojciech; Szubel, Mateusz; Filipowicz, Mariusz

2016-03-01

Moisture content is a main problem of using straw in form of bales for energy production. The paper presents possibility of straw drying in dedicated, innovative and patented in Poland straw dryers which using flue gasses as a drying medium. Paper presents an improved way of drying which proved to be very sufficient. Temperature and humidity of straw during the process of drying were measured. The measurements helped understand and perform numerical model of heat and mass transfer inside the straw bale. By using CFD codes it was possible to perform analysis of phenomenon occurring inside the dried straw bale. Based on the CFD model, proposals of the optimization and improvement process of drying have been discussed. Experimental and computational data have been compared in terms of convergence. A satisfying degree of agreement has been achieved. Applying improved drying method, homogenous field of moisture content and temperature in the straw bale is achieved in a very cost effective way.

Vacuum decay in an interacting multiverse

NASA Astrophysics Data System (ADS)

Robles-Pérez, S.; Alonso-Serrano, A.; Bastos, C.; Bertolami, O.

2016-08-01

We examine a new multiverse scenario in which the component universes interact. We focus our attention to the process of "true" vacuum nucleation in the false vacuum within one single element of the multiverse. It is shown that the interactions lead to a collective behavior that might lead, under specific conditions, to a pre-inflationary phase and ensued distinguishable imprints in the comic microwave background radiation.

Baryogenesis in false vacuum

NASA Astrophysics Data System (ADS)

Hamada, Yuta; Yamada, Masatoshi

2017-09-01

The null result in the LHC may indicate that the standard model is not drastically modified up to very high scales, such as the GUT/string scale. Having this in the mind, we suggest a novel leptogenesis scenario realized in the false vacuum of the Higgs field. If the Higgs field develops a large vacuum expectation value in the early universe, a lepton number violating process is enhanced, which we use for baryogenesis. To demonstrate the scenario, several models are discussed. For example, we show that the observed baryon asymmetry is successfully generated in the standard model with higher-dimensional operators.

Study of a dry room in a battery manufacturing plant using a process model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, Shabbir; Nelson, Paul A.; Dees, Dennis W.

The manufacture of lithium ion batteries requires some processing steps to be carried out in a dry room, where the moisture content should remain below 100 parts per million. The design and operation of such a dry room adds to the cost of the battery. This paper studies the humidity management of the air to and from the dry room to understand the impact of design and operating parameters on the energy demand and the cost contribution towards the battery manufacturing cost. The study is conducted with the help of a process model for a dry room with a volumemore » of 16000 cubic meters. For a defined base case scenario it is found that the dry room operation has an energy demand of approximately 400 kW. The paper explores some tradeoffs in design and operating parameters by looking at the humidity reduction by quenching the make-up air vs. at the desiccant wheel, and the impact of the heat recovery from the desiccant regeneration cycle.« less

Process analytical technologies (PAT) in freeze-drying of parenteral products.

PubMed

Patel, Sajal Manubhai; Pikal, Michael

2009-01-01

Quality by Design (QbD), aims at assuring quality by proper design and control, utilizing appropriate Process Analytical Technologies (PAT) to monitor critical process parameters during processing to ensure that the product meets the desired quality attributes. This review provides a comprehensive list of process monitoring devices that can be used to monitor critical process parameters and will focus on a critical review of the viability of the PAT schemes proposed. R&D needs in PAT for freeze-drying have also been addressed with particular emphasis on batch techniques that can be used on all the dryers independent of the dryer scale.

Wafer-Level Vacuum Packaging of Smart Sensors.

PubMed

Hilton, Allan; Temple, Dorota S

2016-10-31

The reach and impact of the Internet of Things will depend on the availability of low-cost, smart sensors-"low cost" for ubiquitous presence, and "smart" for connectivity and autonomy. By using wafer-level processes not only for the smart sensor fabrication and integration, but also for packaging, we can further greatly reduce the cost of sensor components and systems as well as further decrease their size and weight. This paper reviews the state-of-the-art in the wafer-level vacuum packaging technology of smart sensors. We describe the processes needed to create the wafer-scale vacuum microchambers, focusing on approaches that involve metal seals and that are compatible with the thermal budget of complementary metal-oxide semiconductor (CMOS) integrated circuits. We review choices of seal materials and structures that are available to a device designer, and present techniques used for the fabrication of metal seals on device and window wafers. We also analyze the deposition and activation of thin film getters needed to maintain vacuum in the ultra-small chambers, and the wafer-to-wafer bonding processes that form the hermetic seal. We discuss inherent trade-offs and challenges of each seal material set and the corresponding bonding processes. Finally, we identify areas for further research that could help broaden implementations of the wafer-level vacuum packaging technology.

Wafer-Level Vacuum Packaging of Smart Sensors

PubMed Central

Hilton, Allan; Temple, Dorota S.

2016-01-01

The reach and impact of the Internet of Things will depend on the availability of low-cost, smart sensors—“low cost” for ubiquitous presence, and “smart” for connectivity and autonomy. By using wafer-level processes not only for the smart sensor fabrication and integration, but also for packaging, we can further greatly reduce the cost of sensor components and systems as well as further decrease their size and weight. This paper reviews the state-of-the-art in the wafer-level vacuum packaging technology of smart sensors. We describe the processes needed to create the wafer-scale vacuum microchambers, focusing on approaches that involve metal seals and that are compatible with the thermal budget of complementary metal-oxide semiconductor (CMOS) integrated circuits. We review choices of seal materials and structures that are available to a device designer, and present techniques used for the fabrication of metal seals on device and window wafers. We also analyze the deposition and activation of thin film getters needed to maintain vacuum in the ultra-small chambers, and the wafer-to-wafer bonding processes that form the hermetic seal. We discuss inherent trade-offs and challenges of each seal material set and the corresponding bonding processes. Finally, we identify areas for further research that could help broaden implementations of the wafer-level vacuum packaging technology. PMID:27809249

Volatile composition and sensory profile of Cantharellus cibarius Fr. as affected by drying method.

PubMed

Politowicz, Joanna; Lech, Krzysztof; Sánchez-Rodríguez, Lucía; Szumny, Antoni; Carbonell-Barrachina, Ángel A

2017-12-01

In this work, the influence of different drying methods on the aroma composition and sensory quality of chanterelle mushrooms (Cantharellus cibarius Fr.) was evaluated. The drying methods tested were convective drying (CD), freeze drying (FD), vacuum microwave drying (VMD) and a combination of convective pre-drying and vacuum microwave finish drying (CPD-VMFD). Analyses of fresh and dried chanterelle samples by HS-SPME and GC/MS and GC-FID showed the presence of 39 volatile compounds at different concentrations. The most abundant compounds in fresh chanterelle were 1-hexanol (33.4 μg per 100 g dry basis (db)), 1-octen-3-ol (80.2 μg per 100 g db) and 2-octen-1-ol (19.3 μg per 100 g db). The results showed that fresh and dried chanterelle contained very low levels of aroma compounds; however, the highest contents of volatile compounds were found in samples after (i) CD at 80 °C (129 μg per 100 g db), (ii) CPD-VMFD at 70 °C-480/240 W (136 μg per 100 g db) and (iii) CPD-VMFD at 80 °C-480/240 W (136 μg per 100 g db). The best dehydration methods, which resulted in high contents of volatile compounds and appropriate sensory quality, according to descriptive sensory analysis and PCA tools, were CD at 70 and 80 °C. Besides, these methods led to spongy dried mushrooms with high intensities of fresh, mushroom ID, with proper color and without intense shrinkage. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Meeting today's requirements for large thermal vacuum test facilities

NASA Technical Reports Server (NTRS)

Corinth, R. L.; Rouse, J. A.

1986-01-01

The Lockheed Thermal Vacuum Facility at Sunnyvale, California, completed in late 1986, one of the largest multi-program facilities constructed to date is described. The horizontal 12.2 m diameter by 24.4 m long chamber has removable heads at each end and houses a thermal shroud providing a test volume 10.4 m diameter by 24.4 m long. The chamber and thermal shroud are configured to permit the insertion of a 6.1 m wide by 24.4 m long vibration isolated optical bench. The pumpimg system incorporates an internal cryopumping array, turbomolecular pumps and cryopumps to handle multi-program needs and ranges of gas loads. The high vacuum system is capable of achieving clean, dry and empty pressures below 1.3 times 10 to the minus 6 power Pa (10 to the minus 8 power torr.)

Global Sensitivity Analysis as Good Modelling Practices tool for the identification of the most influential process parameters of the primary drying step during freeze-drying.

PubMed

Van Bockstal, Pieter-Jan; Mortier, Séverine Thérèse F C; Corver, Jos; Nopens, Ingmar; Gernaey, Krist V; De Beer, Thomas

2018-02-01

Pharmaceutical batch freeze-drying is commonly used to improve the stability of biological therapeutics. The primary drying step is regulated by the dynamic settings of the adaptable process variables, shelf temperature T s and chamber pressure P c . Mechanistic modelling of the primary drying step leads to the optimal dynamic combination of these adaptable process variables in function of time. According to Good Modelling Practices, a Global Sensitivity Analysis (GSA) is essential for appropriate model building. In this study, both a regression-based and variance-based GSA were conducted on a validated mechanistic primary drying model to estimate the impact of several model input parameters on two output variables, the product temperature at the sublimation front T i and the sublimation rate ṁ sub . T s was identified as most influential parameter on both T i and ṁ sub , followed by P c and the dried product mass transfer resistance α Rp for T i and ṁ sub , respectively. The GSA findings were experimentally validated for ṁ sub via a Design of Experiments (DoE) approach. The results indicated that GSA is a very useful tool for the evaluation of the impact of different process variables on the model outcome, leading to essential process knowledge, without the need for time-consuming experiments (e.g., DoE). Copyright © 2017 Elsevier B.V. All rights reserved.

Numerical analysis of temperature field in the high speed rotary dry-milling process

NASA Astrophysics Data System (ADS)

Wu, N. X.; Deng, L. J.; Liao, D. H.

2018-01-01

For the effect of the temperature field in the ceramic dry granulation. Based on the Euler-Euler mathematical model, at the same time, made ceramic dry granulation experiment equipment more simplify and established physical model, the temperature of the dry granulation process was simulated with the granulation time. The relationship between the granulation temperature and granulation effect in dry granulation process was analyzed, at the same time, the correctness of numerical simulation was verified by measuring the fluidity index of ceramic bodies. Numerical simulation and experimental results showed that when granulation time was 4min, 5min, 6min, maximum temperature inside the granulation chamber was: 70°C, 85°C, 95°C. And the equilibrium of the temperature in the granulation chamber was weakened, the fluidity index of the billet particles was: 56.4. 89.7. 81.6. Results of the research showed that when granulation time was 5min, the granulation effect was best. When the granulation chamber temperature was more than 85°C, the fluidity index and the effective particles quantity of the billet particles were reduced.

New approach for dry formulation techniques for rhizobacteria

NASA Astrophysics Data System (ADS)

Elchin, A. A.; Mashinistova, A. V.; Gorbunova, N. V.; Muratov, V. S.; Kydralieva, K. A.; Jorobekova, Sh. J.

2009-04-01

Two beneficial Pseudomonas isolates selected from rhizosphere of abundant weed - couch-grass Elytrigia repens L. Nevski have been found to have biocontrol activity. An adequate biocontrol effect requires high yield and long stability of the bacterial preparation [1], which could be achieved by an effective and stable formulation. This study was aimed to test various approaches to dry formulation techniques for Pseudomonas- based preparations. To reach this goal, two drying formulation techniques have been tested: the first one, spray drying and the second, low-temperature contact-convective drying in fluidized bed. The optimal temperature parameters for each technique were estimated. Main merits of the selected approach to dry technique are high yield, moderate specific energy expenditures per 1 kg of evaporated moisture, minimal time of contact of the drying product with drying agent. The technological process for dry formulation included the following stages: the obtaining of cell liquids, the low-temperature concentrating and the subsequent drying of a concentrate. The preliminary technological stages consist in cultivation of the rhizobacteria cultures and concentrating the cell liquids. The following requirements for cultivation regime in laboratory conditions were proposed: optimal temperatures are 26-28°С in 3 days, concentration of viable cells in cell liquid makes 1010-1011 cell/g of absolutely dry substance (ADS). For concentrating the cell liquids the method of a vacuum evaporation, which preserves both rhizobacteria cells and the secondary metabolites of cell liquid, has been used. The process of concentrating was conducted at the minimum possible temperature, i.e. not above 30-33°С. In this case the concentration of viable cells has decreased up to 109-1010 cell/g of ADS. For spray drying the laboratory up-dated drier BUCHI 190, intended for the drying of thermolabile products, was used. The temperatures of an in- and outcoming air did not exceed

Sewage sludge drying process integration with a waste-to-energy power plant.

PubMed

Bianchini, A; Bonfiglioli, L; Pellegrini, M; Saccani, C

2015-08-01

Dewatered sewage sludge from Waste Water Treatment Plants (WWTPs) is encountering increasing problems associated with its disposal. Several solutions have been proposed in the last years regarding energy and materials recovery from sewage sludge. Current technological solutions have relevant limits as dewatered sewage sludge is characterized by a high water content (70-75% by weight), even if mechanically treated. A Refuse Derived Fuel (RDF) with good thermal characteristics in terms of Lower Heating Value (LHV) can be obtained if dewatered sludge is further processed, for example by a thermal drying stage. Sewage sludge thermal drying is not sustainable if the power is fed by primary energy sources, but can be appealing if waste heat, recovered from other processes, is used. A suitable integration can be realized between a WWTP and a waste-to-energy (WTE) power plant through the recovery of WTE waste heat as energy source for sewage sludge drying. In this paper, the properties of sewage sludge from three different WWTPs are studied. On the basis of the results obtained, a facility for the integration of sewage sludge drying within a WTE power plant is developed. Furthermore, energy and mass balances are set up in order to evaluate the benefits brought by the described integration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dry Process for Making Polyimide/ Carbon-and-Boron-Fiber Tape

NASA Technical Reports Server (NTRS)

Belvin, Harry L.; Cano, Roberto J.; Johnston, Norman J.; Marchello, Joseph M.

2003-01-01

A dry process has been invented as an improved means of manufacturing composite prepreg tapes that consist of high-temperature thermoplastic polyimide resin matrices reinforced with carbon and boron fibers. Such tapes are used (especially in the aircraft industry) to fabricate strong, lightweight composite-material structural components. The inclusion of boron fibers results in compression strengths greater than can be achieved by use of carbon fibers alone. The present dry process is intended to enable the manufacture of prepreg tapes (1) that contain little or no solvent; (2) that have the desired dimensions, fiber areal weight, and resin content; and (3) in which all of the fibers are adequately wetted by resin and the boron fibers are fully encapsulated and evenly dispersed. Prepreg tapes must have these properties to be useable in the manufacture of high-quality composites by automated tape placement. The elimination of solvent and the use of automated tape placement would reduce the overall costs of manufacturing.

Effect of vacuum roasting on acrylamide formation and reduction in coffee beans.

PubMed

Anese, Monica; Nicoli, Maria Cristina; Verardo, Giancarlo; Munari, Marina; Mirolo, Giorgio; Bortolomeazzi, Renzo

2014-02-15

Coffea arabica beans were roasted in an oven at 200 °C for increasing lengths of time under vacuum (i.e. 0.15 kPa). The samples were then analysed for colour, weight loss, acrylamide concentration and sensory properties. Data were compared with those obtained from coffee roasted at atmospheric pressure (i.e. conventional roasting), as well as at atmospheric pressure for 10 min followed by vacuum treatment (0.15 kPa; i.e. conventional-vacuum roasting). To compare the different treatments, weight loss, colour and acrylamide changes were expressed as a function of the thermal effect received by the coffee beans during the different roasting processes. Vacuum-processed coffee with medium roast degree had approximately 50% less acrylamide than its conventionally roasted counterpart. It was inferred that the low pressure generated inside the oven during the vacuum process exerted a stripping effect preventing acrylamide from being accumulated. Vacuum-processed coffee showed similar colour and sensory properties to conventionally roasted coffee. Copyright © 2013 Elsevier Ltd. All rights reserved.

Aeolian process of the dried-up riverbeds of the Hexi Corridor, China: a wind tunnel experiment.

PubMed

Zhang, Caixia; Wang, Xunming; Dong, Zhibao; Hua, Ting

2017-08-01

Wind tunnel studies, which remain limited, are an important tool to understand the aeolian processes of dried-up riverbeds. The particle size, chemical composition, and the mineral contents of sediments arising from the dried river beds are poorly understood. Dried-up riverbeds cover a wide area in the Hexi Corridor, China, and comprise a complex synthesis of different land surfaces, including aeolian deposits, pavement surfaces, and Takyr crust. The results of the present wind tunnel experiment suggest that aeolian transport from the dried-up riverbeds of the Hexi Corridor ranges from 0 to 177.04 g/m 2 /min and that dry riverbeds could be one of the main sources of dust emissions in this region. As soon as the wind velocity reaches 16 m/s and assuming that there are abundant source materials available, aeolian transport intensity increases rapidly. The dried-up riverbed sediment and the associated aeolian transported material were composed mainly of fine and medium sands. However, the transported samples were coarser than the bed samples, because of the sorting effect of the aeolian processes on the sediment. The aeolian processes also led to regional elemental migration and mineral composition variations.

Kinetics of scrap tyre pyrolysis under vacuum conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez, Gartzen; Aguado, Roberto; Olazar, Martin

2009-10-15

Scrap tyre pyrolysis under vacuum is attractive because it allows easier product condensation and control of composition (gas, liquid and solid). With the aim of determining the effect of vacuum on the pyrolysis kinetics, a study has been carried out in thermobalance. Two data analysis methods have been used in the kinetic study: (i) the treatment of experimental data of weight loss and (ii) the deconvolution of DTG (differential thermogravimetry) curve. The former allows for distinguishing the pyrolysis of the three main components (volatile components, natural rubber and styrene-butadiene rubber) according to three successive steps. The latter method identifies themore » kinetics for the pyrolysis of individual components by means of DTG curve deconvolution. The effect of vacuum in the process is significant. The values of activation energy for the pyrolysis of individual components of easier devolatilization (volatiles and NR) are lower for pyrolysis under vacuum with a reduction of 12 K in the reaction starting temperature. The kinetic constant at 503 K for devolatilization of volatile additives at 0.25 atm is 1.7 times higher than that at 1 atm, and that corresponding to styrene-butadiene rubber at 723 K is 2.8 times higher. Vacuum enhances the volatilization and internal diffusion of products in the pyrolysis process, which contributes to attenuating the secondary reactions of the repolymerization and carbonization of these products on the surface of the char (carbon black). The higher quality of carbon black is interesting for process viability. The large-scale implementation of this process in continuous mode requires a comparison to be made between the economic advantages of using a vacuum and the energy costs, which will be lower when the technologies used for pyrolysis require a lower ratio between reactor volume and scrap tyre flow rate.« less

Kinetics of scrap tyre pyrolysis under vacuum conditions.

PubMed

Lopez, Gartzen; Aguado, Roberto; Olazar, Martín; Arabiourrutia, Miriam; Bilbao, Javier

2009-10-01

Scrap tyre pyrolysis under vacuum is attractive because it allows easier product condensation and control of composition (gas, liquid and solid). With the aim of determining the effect of vacuum on the pyrolysis kinetics, a study has been carried out in thermobalance. Two data analysis methods have been used in the kinetic study: (i) the treatment of experimental data of weight loss and (ii) the deconvolution of DTG (differential thermogravimetry) curve. The former allows for distinguishing the pyrolysis of the three main components (volatile components, natural rubber and styrene-butadiene rubber) according to three successive steps. The latter method identifies the kinetics for the pyrolysis of individual components by means of DTG curve deconvolution. The effect of vacuum in the process is significant. The values of activation energy for the pyrolysis of individual components of easier devolatilization (volatiles and NR) are lower for pyrolysis under vacuum with a reduction of 12K in the reaction starting temperature. The kinetic constant at 503K for devolatilization of volatile additives at 0.25atm is 1.7 times higher than that at 1atm, and that corresponding to styrene-butadiene rubber at 723K is 2.8 times higher. Vacuum enhances the volatilization and internal diffusion of products in the pyrolysis process, which contributes to attenuating the secondary reactions of the repolymerization and carbonization of these products on the surface of the char (carbon black). The higher quality of carbon black is interesting for process viability. The large-scale implementation of this process in continuous mode requires a comparison to be made between the economic advantages of using a vacuum and the energy costs, which will be lower when the technologies used for pyrolysis require a lower ratio between reactor volume and scrap tyre flow rate.

Cosmological implications of the transition from the false vacuum to the true vacuum state

NASA Astrophysics Data System (ADS)

Stachowski, Aleksander; Szydłowski, Marek; Urbanowski, Krzysztof

2017-06-01

We study cosmology with running dark energy. The energy density of dark energy is obtained from the quantum process of transition from the false vacuum state to the true vacuum state. We use the Breit-Wigner energy distribution function to model the quantum unstable systems and obtain the energy density of the dark energy parametrization ρ _ {de}(t). We also use Krauss and Dent's idea linking properties of the quantum mechanical decay of unstable states with the properties of the observed Universe. In the cosmological model with this parametrization there is an energy transfer between dark matter and dark energy. The intensity of this process, measured by a parameter α , distinguishes two scenarios. As the Universe starts from the false vacuum state, for the small value of α (0<α <0.4) it goes through an intermediate oscillatory (quantum) regime of the density of dark energy, while for α > 0.4 the density of the dark energy jumps down. In both cases the present value of the density of dark energy is reached. From a statistical analysis we find this model to be in good agreement with the astronomical data and practically indistinguishable from the Λ CDM model.

Sanitizing in Dry-Processing Environments Using Isopropyl Alcohol Quaternary Ammonium Formula.

PubMed

Kane, Deborah M; Getty, Kelly J K; Mayer, Brian; Mazzotta, Alejandro

2016-01-01

Dry-processing environments are particularly challenging to clean and sanitize because introduced water can favor growth and establishment of pathogenic microorganisms such as Salmonella. Our objective was to determine the efficacy of an isopropyl alcohol quaternary ammonium (IPAQuat) formula for eliminating potential Salmonella contamination on food contact surfaces. Clean stainless steel coupons and conveyor belt materials used in dry-processing environments were spot inoculated in the center of coupons (5 by 5 cm) with a six-serotype composite of Salmonella (approximately 10 log CFU/ml), subjected to IPAQuat sanitizer treatments with exposure times of 30 s, 1 min, or 5 min, and then swabbed for enumeration of posttreatment survivors. A subset of inoculated surfaces was soiled with a breadcrumb-flour blend and allowed to sit on the laboratory bench for a minimum of 16 h before sanitation. Pretreatment Salmonella populations (inoculated controls, 0 s treatment) were approximately 7.0 log CFU/25 cm(2), and posttreatment survivors were 1.31, 0.72, and < 0.7 (detection limit) log CFU/25 cm(2) after sanitizer exposure for 30 s, 1 min, or 5 min, respectively, for both clean (no added soil) and soiled surfaces. Treatment with the IPAQuat formula using 30-s sanitizer exposures resulted in 5.68-log reductions, whereas >6.0-log reductions were observed for sanitizer exposures of 1 and 5 min. Because water is not introduced into the processing environment with this approach, the IPAQuat formula could have sanitation applications in dry-processing environments to eliminate potential contamination from Salmonella on food contact surfaces.

Natural vacuum electronics

NASA Technical Reports Server (NTRS)

Leggett, Nickolaus

1990-01-01

The ambient natural vacuum of space is proposed as a basis for electron valves. Each valve is an electron controlling structure similiar to a vacuum tube that is operated without a vacuum sustaining envelope. The natural vacuum electron valves discussed offer a viable substitute for solid state devices. The natural vacuum valve is highly resistant to ionizing radiation, system generated electromagnetic pulse, current transients, and direct exposure to space conditions.

Processing of extraterrestrial materials by high temperature vacuum vaporization

NASA Technical Reports Server (NTRS)

Grimley, R. T.; Lipschutz, M. E.

1983-01-01

It is noted that problems associated with the extraction and concentration of elements and commpounds important for the construction and operation of space habitats have received little attention. High temperature vacuum vaporization is considered a promising approach; this is a technique for which the space environment offers advantages in the form of low ambient pressures and temperatures and the possibility of sustained high temperatures via solar thermal energy. To establish and refine this new technology, experimental determinations must be made of the material release profiles as a function of temperature, of the release kinetics and chemical forms of material being transported, and of the various means of altering release kinetics. Trace element data determined by neutron activation analysis of meteorites heated to 1400 C in vacuum is summarized. The principal tool, high temperature spectrometry, is used to examine the vaporization thermodynamics and kinetics of major and minor elements from complex multicomponent extraterrestrial materials.

Marginal adaptation of mineral trioxide aggregate (MTA) compared with amalgam as a root-end filling material: a low-vacuum (LV) versus high-vacuum (HV) SEM study.

PubMed

Shipper, G; Grossman, E S; Botha, A J; Cleaton-Jones, P E

2004-05-01

To compare the marginal adaptation of mineral trioxide aggregate (MTA) or amalgam root-end fillings in extracted teeth under low-vacuum (LV) versus high-vacuum (HV) scanning electron microscope (SEM) viewing conditions. Root-end fillings were placed in 20 extracted single-rooted maxillary teeth. Ten root ends were filled with MTA and the other 10 root ends were filled with amalgam. Two 1 mm thick transverse sections of each root-end filling were cut 0.50 mm (top) and 1.50 mm (bottom) from the apex. Gap size was recorded at eight fixed points along the dentine-filling material interface on each section when uncoated wet (LV wet (LVW)) and dry under LV (0.3 Torr) in a JEOL JSM-5800 SEM and backscatter emission (LV dry uncoated (LVDU)). The sections were then air-dried, gold-coated and gap size was recorded once again at the fixed points under HV (10(-6) Torr; HV dry coated (HVDC)). Specimen cracking, and the size and extent of the crack were noted. Gap sizes at fixed points were smallest under LVW and largest under HVDC SEM conditions. Gaps were smallest in MTA root-end fillings. A General Linear Models Analysis, with gap size as the dependent variable, showed significant effects for extent of crack in dentine, material and viewing condition (P = 0.0001). This study showed that MTA produced a superior marginal adaptation to amalgam, and that LVW conditions showed the lowest gap size. Gap size was influenced by the method of SEM viewing. If only HV SEM viewing conditions are used for MTA and amalgam root-end fillings, a correction factor of 3.5 and 2.2, respectively, may be used to enable relative comparisons of gap size to LVW conditions.

VACUUM TRAP

DOEpatents

Gordon, H.S.

1959-09-15

An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

Changes in Composition and Phosphorus Profile during Dry Grind Process of Corn into Ethanol and DDGS

USDA-ARS?s Scientific Manuscript database

Demand for alternatives to fossil fuels has resulted in a dramatic increase in ethanol production from corn. Dry grind method has been a major process, resulting in a large volume of dried distiller grains with solubles (DDGS) as a co-product. The process consists of grinding, cooking, liquefactio...

Evaluation of Heat Flux Measurement as a New Process Analytical Technology Monitoring Tool in Freeze Drying.

PubMed

Vollrath, Ilona; Pauli, Victoria; Friess, Wolfgang; Freitag, Angelika; Hawe, Andrea; Winter, Gerhard

2017-05-01

This study investigates the suitability of heat flux measurement as a new technique for monitoring product temperature and critical end points during freeze drying. The heat flux sensor is tightly mounted on the shelf and measures non-invasively (no contact with the product) the heat transferred from shelf to vial. Heat flux data were compared to comparative pressure measurement, thermocouple readings, and Karl Fischer titration as current state of the art monitoring techniques. The whole freeze drying process including freezing (both by ramp freezing and controlled nucleation) and primary and secondary drying was considered. We found that direct measurement of the transferred heat enables more insights into thermodynamics of the freezing process. Furthermore, a vial heat transfer coefficient can be calculated from heat flux data, which ultimately provides a non-invasive method to monitor product temperature throughout primary drying. The end point of primary drying determined by heat flux measurements was in accordance with the one defined by thermocouples. During secondary drying, heat flux measurements could not indicate the progress of drying as monitoring the residual moisture content. In conclusion, heat flux measurements are a promising new non-invasive tool for lyophilization process monitoring and development using energy transfer as a control parameter. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

9 CFR 590.542 - Spray process drying operations.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., including sifters, conveyors, and powder coolers shall be either wet washed or dry cleaned. A combination of wet washing and dry cleaning of the complete drying unit shall not be permitted unless that segment of...

9 CFR 590.542 - Spray process drying operations.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., including sifters, conveyors, and powder coolers shall be either wet washed or dry cleaned. A combination of wet washing and dry cleaning of the complete drying unit shall not be permitted unless that segment of...

9 CFR 590.542 - Spray process drying operations.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., including sifters, conveyors, and powder coolers shall be either wet washed or dry cleaned. A combination of wet washing and dry cleaning of the complete drying unit shall not be permitted unless that segment of...

9 CFR 590.542 - Spray process drying operations.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., including sifters, conveyors, and powder coolers shall be either wet washed or dry cleaned. A combination of wet washing and dry cleaning of the complete drying unit shall not be permitted unless that segment of...

9 CFR 590.542 - Spray process drying operations.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., including sifters, conveyors, and powder coolers shall be either wet washed or dry cleaned. A combination of wet washing and dry cleaning of the complete drying unit shall not be permitted unless that segment of...

Red rubber bulb, cheap and effective vacuum drainage.

PubMed

Vatanasapt, V; Areemit, S; Jeeravipoolvarn, P; Kuyyakanond, T; Kuptarnond, C

1989-04-01

Red rubber bulbs have been used for vacuum drainage in head, neck, breast and several other operations by the authors since 1975 quite effectively without any major problems. The vacuum pressure of the red rubber bulbs was found to be higher than the expensive commercially available vacuum wound drainage device. The question of remaining old blood and infective microorganisms inside the reservoir for the reused ones were tested by the manual cleaning process and the standard sterile technique using steam under increased pressure (autoclave). The result is quite satisfactory. We encourage the use of this cheap and effective (made in Thailand) vacuum wound drainage in Thai hospitals and Thai medical schools.

Effect of drying process assisted by high-pressure impregnation on protein quality and digestibility in red abalone (Haliotis rufescens).

PubMed

Cepero-Betancourt, Yamira; Oliva-Moresco, Patricio; Pasten-Contreras, Alexis; Tabilo-Munizaga, Gipsy; Pérez-Won, Mario; Moreno-Osorio, Luis; Lemus-Mondaca, Roberto

2017-10-01

Abalone (Haliotis spp.) is an exotic seafood product recognized as a protein source of high biological value. Traditional methods used to preserve foods such as drying technology can affect their nutritional quality (protein quality and digestibility). A 28-day rat feeding study was conducted to evaluate the effects of the drying process assisted by high-pressure impregnation (HPI) (350, 450, and 500 MPa × 5 min) on chemical proximate and amino acid compositions and nutritional parameters, such as protein efficiency ratio (PER), true digestibility (TD), net protein ratio, and protein digestibility corrected amino acid score (PDCAAS) of dried abalone. The HPI-assisted drying process ensured excellent protein quality based on PER values, regardless of the pressure level. At 350 and 500 MPa, the HPI-assisted drying process had no negative effect on TD and PDCAAS then, based on nutritional parameters analysed, we recommend HPI-assisted drying process at 350 MPa × 5 min as the best process condition to dry abalone. Variations in nutritional parameters compared to casein protein were observed; nevertheless, the high protein quality and digestibility of HPI-assisted dried abalones were maintained to satisfy the metabolic demands of human beings.

7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes. 319.56-11 Section 319.56-11 Agriculture Regulations of the Department of..., vegetables, nuts, and legumes. (a) Dried, cured, or processed fruits and vegetables (except frozen fruits and...

7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 5 2011-01-01 2011-01-01 false Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes. 319.56-11 Section 319.56-11 Agriculture Regulations of the Department of..., vegetables, nuts, and legumes. (a) Dried, cured, or processed fruits and vegetables (except frozen fruits and...

Ni-MH battery electrodes made by a dry powder process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Z.; Sakai, T.; Noreus, D.

1995-12-01

A dry powder roller pressing process, once developed for making both of the electrodes in low cost Ni-Cd consumer batteries, has been utilized to make electrodes for Ni-MH batteries. The process was evaluated by manually making a series of sub-C type cells that were characterized with respect to specific capacity, cycle life, and self-discharge. The performance was comparable in several respects with that of cells made by more complex Ni-foam technologies.

Pharmaceutical spray drying: solid-dose process technology platform for the 21st century.

PubMed

Snyder, Herman E

2012-07-01

Requirement for precise control of solid-dosage particle properties created with a scalable process technology are continuing to expand in the pharmaceutical industry. Alternate methods of drug delivery, limited active drug substance solubility and the need to improve drug product stability under room-temperature conditions are some of the pharmaceutical applications that can benefit from spray-drying technology. Used widely for decades in other industries with production rates up to several tons per hour, pharmaceutical uses for spray drying are expanding beyond excipient production and solvent removal from crystalline material. Creation of active pharmaceutical-ingredient particles with combinations of unique target properties are now more common. This review of spray-drying technology fundamentals provides a brief perspective on the internal process 'mechanics', which combine with both the liquid and solid properties of a formulation to enable high-throughput, continuous manufacturing of precision powder properties.

Papaya drying and waste conversion system. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1982-02-12

This project, performed under United States Department of Energy Small-scale Appropriate Energy Technology Grant, involves demonstration of an integrated system using solar energy to process off-grade or reject fruit into marketable food products. The integrated system consists of three phases: (1) solar dehydration of usable fruit; (2) solar vacuum distillation of fermented wastes (peelings, rinds, skins, and seeds) to produce an ethanol fuel to use as a backup source of heat for dehydration; and (3) land reclamation by mixing stillage and compost with volcanic cinder and ash to produce on marginal land a rich soil suitable for growing more cropsmore » to dry. Although the system is not 100% complete the investigators have demonstrated that a small business can efficiently use solar energies in an integrated fashion to process waste into food, improve the quality of the land, and provide meaningful jobs in a region of very high unemployment.« less

[Drying characteristics and apparent change of sludge granules during drying].

PubMed

Ma, Xue-Wen; Weng, Huan-Xin; Zhang, Jin-Jun

2011-08-01

Three different weight grades of sludge granules (2.5, 5, 10 g) were dried at constant temperature of 100, 200, 300, 400 and 500 degrees C, respectively. Then characteristics of weight loss and change of apparent form during sludge drying were analyzed. Results showed that there were three stages during sludge drying at 100-200 degrees C: acceleration phase, constant-rate phase, and falling-rate phase. At 300-500 degrees C, there were no constant-rate phase, but due to lots of cracks generated at sludge surface, average drying rates were still high. There was a quadratic nonlinear relationship between average drying rate and drying temperature. At 100-200 degrees C, drying processes of different weight grade sludge granules were similar. At 300-500 degrees C, drying processes of same weight grade of sludge granules were similar. Little organic matter decomposed till sludge burning at 100-300 degrees C, while some organic matter began to decompose at the beginning of sludge drying at 400-500 degrees C.

Encapsulation of black carrot juice using spray and freeze drying.

PubMed

Murali, S; Kar, Abhijit; Mohapatra, Debabandya; Kalia, Pritam

2015-12-01

Black carrot juice extracted using pectinase enzyme was encapsulated in three different carrier materials (maltodextrin 20DE, gum arabic and tapioca starch) using spray drying at four inlet temperatures (150, 175, 200 and 225 ℃) and freeze drying at a constant temperature of - 53 ℃ and vacuum of 0.22-0.11 mbar with the constant feed mixture. The products were analyzed for total anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and total colour change. For both the drying methods followed in this study, maltodextrin 20DE as the carrier material has proven to be better in retaining maximum anthocyanin and antioxidant activity compared to gum arabic and tapioca starch. The best spray dried product, was obtained at 150 ℃. The most acceptable was the freeze dried product with maximum anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and colour change. © The Author(s) 2014.

Breakdown Conditioning Chacteristics of Precision-Surface-Treatment-Electrode in Vacuum

NASA Astrophysics Data System (ADS)

Kato, Kastumi; Fukuoka, Yuji; Inagawa, Yukihiko; Saitoh, Hitoshi; Sakaki, Masayuki; Okubo, Hitoshi

Breakdown (BD) characteristics in vacuum are strongly dependent on the electrode surface condition, like the surface roughness etc. Therefore, in order to develop a high voltage vacuum circuit breaker, it is important to optimize the surface treatment process. This paper discusses about the effect of precision-surface-treatment of the electrode on breakdown conditioning characteristics under non-uniform electric field in vacuum. Experimental results reveal that the electrode surface treatment affects the conditioning process, especially the BD voltage and the BD field strength at the initial stage of the conditioning.

Application of residual polysaccharide-degrading enzymes in dried shiitake mushrooms as an enzyme preparation in food processing.

PubMed

Tatsumi, E; Konishi, Y; Tsujiyama, S

2016-11-01

To examine the activities of residual enzymes in dried shiitake mushrooms, which are a traditional foodstuff in Japanese cuisine, for possible applications in food processing. Polysaccharide-degrading enzymes remained intact in dried shiitake mushrooms and the activities of amylase, β-glucosidase and pectinase were high. A potato digestion was tested using dried shiitake powder. The enzymes reacted with potato tuber specimens to solubilize sugars even under a heterogeneous solid-state condition and that their reaction modes were different at 38 and 50 °C. Dried shiitake mushrooms have a potential use in food processing as an enzyme preparation.

Waveguide quantum electrodynamics in squeezed vacuum

NASA Astrophysics Data System (ADS)

You, Jieyu; Liao, Zeyang; Li, Sheng-Wen; Zubairy, M. Suhail

2018-02-01

We study the dynamics of a general multiemitter system coupled to the squeezed vacuum reservoir and derive a master equation for this system based on the Weisskopf-Wigner approximation. In this theory, we include the effect of positions of the squeezing sources which is usually neglected in the previous studies. We apply this theory to a quasi-one-dimensional waveguide case where the squeezing in one dimension is experimentally achievable. We show that while dipole-dipole interaction induced by ordinary vacuum depends on the emitter separation, the two-photon process due to the squeezed vacuum depends on the positions of the emitters with respect to the squeezing sources. The dephasing rate, decay rate, and the resonance fluorescence of the waveguide-QED in the squeezed vacuum are controllable by changing the positions of emitters. Furthermore, we demonstrate that the stationary maximum entangled NOON state for identical emitters can be reached with arbitrary initial state when the center-of-mass position of the emitters satisfies certain conditions.

Vacuum pumps and systems: A review of current practice

NASA Technical Reports Server (NTRS)

Giles, Stuart

1986-01-01

A review of the fundamental characteristics of the many types of vacuum pumps and vacuum pumping systems is given. The optimum pumping range, relative cost, performance limitations, maintenance problems, system operating costs and similar subjects are discussed. Experiences from the thin film deposition, chemical processing, material handling, food processing and other industries, as well as space simulation are used to support conclusions and recommendations.

Accelerated vacuum testing of long life ball bearings and sliprings

NASA Technical Reports Server (NTRS)

Meeks, C. R.; Christy, R. I.; Cunningham, A. C.

1971-01-01

Extensive analytical studies and testing have been conducted on bearings and sliprings in vacuum at temperatures from 30 to 130 F. Thirty-six bearings lubricated with two types of oil were tested in vacuum of less than 10 to the minus 8th power torr at speeds from 55 to 180 rpm. Temperatures, load, speed, and oil viscosity were varied to evaluate the effects on life and wear. All bearings performed successfully during a 7-month test, and the potential merits of the two oils were compared. Over 25 different, dry-lubricated brush/slipring material combinations have been tested, with variations of brush and ring design and surface speed. Test results indicate the probability of 10 years or more of slipring and brush lifetime with properly designed brushes for 1-in.-diameter ring rotating at 60 rpm.

Optimization of process parameters for foam-mat drying of papaya pulp.

PubMed

Kandasamy, Palani; Varadharaju, N; Kalemullah, S; Maladhi, D

2014-10-01

Experiments were carried out to optimize the process parameters for production of papaya powder using foam-mat drying. Papaya pulp was foamed by incorporating methyl cellulose (0.25, 0.5, 0.75 and 1 %, w/w), glycerol-mono-stearate (1, 2, 3 and 4 %, w/w) and egg white (5, 10, 15 and 20 %, w/w) as foaming agents. The maximum stable foam formation was 72, 90 and 125% at 0.75 % methyl cellulose, 3 % glycerol-mono-stearate and 15 % egg white respectively with 9°Brix pulp and whipping time of 20 min. The foamed pulp was dried at air temperature of 60, 65 and 70 °C with foam thickness of 2, 4, 6, 8 and 10 mm in a batch type cabinet dryer. The drying time required for foamed papaya pulp was lower than non-foamed pulp at all selected temperatures. Biochemical analysis results showed a significant reduction in ascorbic acid, β-carotene and total sugars in the foamed papaya dried product at higher foam thickness (6, 8 and 10 mm) and temperature (65 and 70 °C due to destruction at higher drying temperature and increasing time. There was no significant change in other biochemical constituents such as pH and acidity. The organoleptic and sensory evaluation of the quality attributes of papaya powder obtained from the pulp of 9°Brix added with 3 % glycerol-mono-stearate, whipped for 20 min and dried with a foam thickness of 4 mm at a temperature of 60 °C was found to be optimum to produce the foam-mat dried papaya powder.

Recycling of waste lead storage battery by vacuum methods.

PubMed

Lin, Deqiang; Qiu, Keqiang

2011-07-01

Waste lead storage battery is the most important recyclable lead material not only in various European and other OECD countries but also in China. Pollution control of lead has become the focus of people's attention in the world. A vacuum process for recycling waste lead storage battery was developed in this work. The experimental results showed that all the valuable materials in waste lead storage battery could be satisfactorily recycled by vacuum technologies. The vacuum melting of lead grids and the vacuum reduction of lead pastes produce the lead bullion with the direct recovery ratio of 96.29% and 98.98%, respectively. The vacuum pyrolysis of plastics can produce pyrolysis oil with yield of more than 93 wt.%. These vacuum recycling technologies offer improvements in metallurgical and environmental performance. Copyright © 2011 Elsevier Ltd. All rights reserved.

Window-assisted nanosphere lithography for vacuum micro-nano-electronics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Nannan; Institute of Electronic Engineering, Chinese Academy of Engineering Physics, Mianyang, 621900; Pang, Shucai

2015-04-15

Development of vacuum micro-nano-electronics is quite important for combining the advantages of vacuum tubes and solid-state devices but limited by the prevailing fabricating techniques which are expensive, time consuming and low-throughput. In this work, window-assisted nanosphere lithography (NSL) technique was proposed and enabled the low-cost and high-efficiency fabrication of nanostructures for vacuum micro-nano-electronic devices, thus allowing potential applications in many areas. As a demonstration, we fabricated high-density field emitter arrays which can be used as cold cathodes in vacuum micro-nano-electronic devices by using the window-assisted NSL technique. The details of the fabricating process have been investigated. This work provided amore » new and feasible idea for fabricating nanostructure arrays for vacuum micro-nano-electronic devices, which would spawn the development of vacuum micro-nano-electronics.« less

Comparison of vacuum and non-vacuum urine tubes for urinary sediment analysis.

PubMed

Topcuoglu, Canan; Sezer, Sevilay; Kosem, Arzu; Ercan, Mujgan; Turhan, Turan

2017-12-01

Urine collection systems with aspiration system for vacuum tubes are becoming increasingly common for urinalysis, especially for microscopic examination of the urine. In this study, we aimed to examine whether vacuum aspiration of the urine sample has any adverse effect on sediment analysis by comparing results from vacuum and non-vacuum urine tubes. The study included totally 213 urine samples obtained from inpatients and outpatients in our hospital. Urine samples were collected to containers with aspiration system for vacuum tubes. Each sample was aliquoted to both vacuum and non-vacuum urine tubes. Urinary sediment analysis was performed using manual microscope. Results were evaluated using chi-square test. Comparison of the sediment analysis results from vacuum and non-vacuum urine tubes showed that results were highly concordant for erythrocyte, leukocyte and epithelial cells (gamma values 1, 0.997, and 0.994, respectively; p < .001). Results were also concordant for urinary casts, crystals and yeast (kappa values 0.815, 0.945 and 1, respectively; p < .001). The results show that in urinary sediment analysis, vacuum aspiration has no adverse effect on the cellular components except on casts.

Wafer-level vacuum/hermetic packaging technologies for MEMS

NASA Astrophysics Data System (ADS)

Lee, Sang-Hyun; Mitchell, Jay; Welch, Warren; Lee, Sangwoo; Najafi, Khalil

2010-02-01

An overview of wafer-level packaging technologies developed at the University of Michigan is presented. Two sets of packaging technologies are discussed: (i) a low temperature wafer-level packaging processes for vacuum/hermeticity sealing, and (ii) an environmentally resistant packaging (ERP) technology for thermal and mechanical control as well as vacuum packaging. The low temperature wafer-level encapsulation processes are implemented using solder bond rings which are first patterned on a cap wafer and then mated with a device wafer in order to encircle and encapsulate the device at temperatures ranging from 200 to 390 °C. Vacuum levels below 10 mTorr were achieved with yields in an optimized process of better than 90%. Pressures were monitored for more than 4 years yielding important information on reliability and process control. The ERP adopts an environment isolation platform in the packaging substrate. The isolation platform is designed to provide low power oven-control, vibration isolation and shock protection. It involves batch flip-chip assembly of a MEMS device onto the isolation platform wafer. The MEMS device and isolation structure are encapsulated at the wafer-level by another substrate with vertical feedthroughs for vacuum/hermetic sealing and electrical signal connections. This technology was developed for high performance gyroscopes, but can be applied to any type of MEMS device.

Effects of composite surface coating and pre-drying on the properties of kabanosy dry sausage.

PubMed

Tyburcy, Andrzej; Kozyra, Daniel

2010-10-01

Coating of dry sausages with renewable materials could be an alternative to vacuum packaging. In this study kabanosy dry sausage was coated with a composite emulsion and stored for 7 or 15 days at 4-6 degrees C. Effects of different emulsion formulas (0.5 or 1% w/w of kappa-carrageenan and 5 or 10% w/w of glycerol) and pre-drying of coated sausages (at 50 degrees C for 1.5h) were investigated. Carrageenan concentration had a significant effect (Pdrying of coated sausages reduced peeled product weight loss after storage. The financial analysis showed that among coatings tested the best proved to be the emulsion containing (w/w): 5% glycerol, 5% gelatin, 0.5% carrageenan, 20% lard, 20% beeswax, and 50% water. Copyright (c) 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

Influence of Water Content on Mechanical Properties of Rock in Both Saturation and Drying Processes

NASA Astrophysics Data System (ADS)

Zhou, Zilong; Cai, Xin; Cao, Wenzhuo; Li, Xibing; Xiong, Cheng

2016-08-01

Water content has a pronounced influence on the properties of rock materials, which is responsible for many rock engineering hazards, such as landslides and karst collapse. Meanwhile, water injection is also used for the prevention of some engineering disasters like rock-bursts. To comprehensively investigate the effect of water content on mechanical properties of rocks, laboratory tests were carried out on sandstone specimens with different water contents in both saturation and drying processes. The Nuclear Magnetic Resonance technique was applied to study the water distribution in specimens with variation of water contents. The servo-controlled rock mechanics testing machine and Split Hopkinson Pressure Bar technique were used to conduct both compressive and tensile tests on sandstone specimens with different water contents. From the laboratory tests, reductions of the compressive and tensile strength of sandstone under static and dynamic states in different saturation processes were observed. In the drying process, all of the saturated specimens could basically regain their mechanical properties and recover its strength as in the dry state. However, for partially saturated specimens in the saturation and drying processes, the tensile strength of specimens with the same water content was different, which could be related to different water distributions in specimens.

Impact of high pressure treatment and intramuscular fat content on colour changes and protein and lipid oxidation in sliced and vacuum-packaged Iberian dry-cured ham.

PubMed

Fuentes, Verónica; Utrera, Mariana; Estévez, Mario; Ventanas, Jesús; Ventanas, Sonia

2014-08-01

The effect of high hydrostatic pressure (HHP) (600MPa) and intramuscular fat content (IMF) on colour parameters and oxidative stability of lipids and proteins in sliced vacuum-packaged Iberian dry-cured ham during refrigerated storage (120 days at 2°C) was investigated. Several studies have investigated the influence of HHP on lipid oxidation of meat products. However, its effects on protein carbonylation, as also the influence of IMF content on this carbonylation are poorly understood. HHP treatment had a significant effect on lean lightness after 0 and 120 days of storage while IMF content increased lightness and yellowness over time. Regarding oxidative stability, the effect of HHP treatment depended on IMF content samples with a high IMF having greater lipid instability while samples with a low IMF underwent more protein carbonylation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Researches on Position Detection for Vacuum Switch Electrode

NASA Astrophysics Data System (ADS)

Dong, Huajun; Guo, Yingjie; Li, Jie; Kong, Yihan

2018-03-01

Form and transformation character of vacuum arc is important influencing factor on the vacuum switch performance, and the dynamic separations of electrode is the chief effecting factor on the transformation of vacuum arcs forms. Consequently, how to detect the position of electrode to calculate the separations in the arcs image is of great significance. However, gray level distribution of vacuum arcs image isn’t even, the gray level of burning arcs is high, but the gray level of electrode is low, meanwhile, the forms of vacuum arcs changes sharply, the problems above restrict electrode position detection precisely. In this paper, algorithm of detecting electrode position base on vacuum arcs image was proposed. The digital image processing technology was used in vacuum switch arcs image analysis, the upper edge and lower edge were detected respectively, then linear fitting was done using the result of edge detection, the fitting result was the position of electrode, thus, accurate position detection of electrode was realized. From the experimental results, we can see that: algorithm described in this paper detected upper and lower edge of arcs successfully and the position of electrode was obtained through calculation.

Effect of the ripening time under vacuum and packaging film permeability on processing and quality characteristics of low-fat fermented sausages.

PubMed

Liaros, N G; Katsanidis, E; Bloukas, J G

2009-12-01

The effect of vacuum ripening of low-fat fermented sausages packaged in films with different permeabilities on their microbiological, physicochemical and sensorial characteristics was studied. High-fat control sausages were produced with 30% initial fat and low-fat sausages with 10% initial fat. The low-fat sausages were separated into: (a) non-packaged (control) and (b) packaged under vacuum on 7th, 12th and 17th day of processing, remaining under vacuum during the ripening period for 21, 16 and 11days, respectively, in three different oxygen (100, 38 and⩽5cm(3)/m(2)/24h/1atm) and water vapour (4.5, <2.5 and 1g/m(2)24h) permeability plastic bags. Vacuum packaging reduced (p<0.05) the weight loss, the hardness and extent of lipid oxidation in the sausages, increased (p<0.05) their lightness, but had no effect (p>0.05) on the redness, compared to the control sausages. Packaging low-fat fermented sausages under vacuum for the last 11days of ripening in packaging film with high permeability increased (p<0.05) the lactic acid bacteria count. The same product packaged in film with medium permeability had a higher (p<0.05) Micrococcaceae count and the same (p>0.05) hardness and overall acceptability as the high-fat control sausages. A ripening time of 11days and the medium packaging film permeability were the most appropriate conditions for the vacuum packaging of low-fat fermented sausages.

Method for vacuum fusion bonding

DOEpatents

Ackler, Harold D.; Swierkowski, Stefan P.; Tarte, Lisa A.; Hicks, Randall K.

2001-01-01

An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

Kinetics, biocompounds, antioxidant activity, and sensory attributes of quinces as affected by drying method.

PubMed

Szychowski, Przemysław J; Lech, Krzysztof; Sendra-Nadal, Esther; Hernández, Francisca; Figiel, Adam; Wojdyło, Aneta; Carbonell-Barrachina, Ángel A

2018-07-30

Quinces are attracting interest due to their health and nutritional benefits. Drying kinetics, bioactive compounds, antioxidant activity, and the main sensory parameters were determined in dried quinces, cultivar Leskovač, as affected by the drying method. The highest total polyphenols content was observed in dried samples obtained after freeze drying and convective drying at 50 °C. The best drying treatment, considering only sensory attributes, was vacuum-microwave drying at 480 W, because it led to intermediate dark color and high intensities of basic tastes and key flavor attributes. The studied parameters were finally used to recommend convective drying at 60 °C as the most appropriate drying method for quinces, because it had a high content of total phenolic compounds (2nd best treatment out of 10), a good sensory profile, was cheap, and caused no negative effects on nutritional or sensory parameters; the only disadvantage was its long drying time. Copyright © 2018 Elsevier Ltd. All rights reserved.

Change of the structure and the digestibility of myofibrillar proteins in Nanjing dry-cured duck during processing.

PubMed

Du, Xiaojing; Sun, Yangying; Pan, Daodong; Wang, Ying; Ou, Changrong; Cao, Jinxuan

2018-06-01

To investigate the change of bioavailability and structure of myofibrillar proteins during Nanjing dry-cured duck processing, carbonyl content, sulfhydryl (SH) group, disulfide (SS) group, sodium dodecyl sulfate polyacrylamide gel electrophoresis, surface hydrophobicity, secondary structures and in vitro digestibility were determined. During processing, carbonyl content and surface hydrophobicity increased; SH turned into SS group; α-helix turned into β-sheet and random coil fractions. Protein degradation occurred during dry-curing and drying-ripening stages. The in vitro digestibility of pepsin and pancreatic proteases increased during the salt curing stage and decreased during the drying-ripening stage. The increase of digestibility could be attributed to the mild oxidation, degradation and unfolding of proteins while the decrease of digestibility was related to the intensive oxidation and aggregation of proteins. Protein degradation was not a main factor of digestibility during the drying-ripening stage. Results demonstrated that the bioavailability loss of myofibrillar proteins in Nanjing dry-cured duck occurred during the stage of drying-ripening instead of curing. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... The following requirements apply to vehicles with vacuum brake assist units and vacuum brake systems. (a) Vacuum brake assist unit integrity. The vacuum brake assist unit shall demonstrate integrity as... maintained on the pedal. (1) Inspection procedure. Stop the engine and apply service brake several times to...

Method for removing volatile components from a ceramic article, and related processes

DOEpatents

Klug, Frederic Joseph; DeCarr, Sylvia Marie

2002-01-01

A method of removing substantially all of the volatile component in a green, volatile-containing ceramic article is disclosed. The method comprises freezing the ceramic article; and then subjecting the frozen article to a vacuum for a sufficient time to freeze-dry the article. Frequently, the article is heated while being freeze-dried. Use of this method efficiently reduces the propensity for any warpage of the article. The article is often formed from a ceramic slurry in a gel-casting process. A method for fabricating a ceramic core used in investment casting is also described.

BIOMASS DRYING TECHNOLOGIES

EPA Science Inventory

The report examines the technologies used for drying of biomass and the energy requirements of biomass dryers. Biomass drying processes, drying methods, and the conventional types of dryers are surveyed generally. Drying methods and dryer studies using superheated steam as the d...

Demonstrations with a Vacuum: Old Demonstrations for New Vacuum Pumps.

ERIC Educational Resources Information Center

Greenslade, Thomas B., Jr.

1989-01-01

Explains mechanisms of 19th-century vacuum pumps. Describes demonstrations using the pump including guinea and feather tube, aurora tube, electric egg, Gassiots cascade, air mill, bell in vacuum, density and buoyancy of air, fountain in vacuum, mercury shower, palm and bladder glasses, Bacchus demonstration, pneumatic man-lifter, and Magdeburg…

A comparison between atmospheric/humidity and vacuum cyanoacrylate fuming of latent fingermarks.

PubMed

Farrugia, Kevin J; Fraser, Joanna; Friel, Lauren; Adams, Duncan; Attard-Montalto, Nicola; Deacon, Paul

2015-12-01

A number of pseudo-operational trials were set up to compare the atmospheric/humidity and vacuum cyanoacrylate fuming processes on plastic carrier bags. The fuming processes were compared using two-step cyanoacrylate fuming with basic yellow 40 (BY40) staining and a one-step fluorescent cyanoacrylate fuming, Lumicyano 4%. Preliminary work using planted fingermarks and split depletions were performed to identify the optimum vacuum fuming conditions. The first pseudo-operational trial compared the different fuming conditions (atmospheric/humidity vs. vacuum) for the two-step process where an additional 50% more marks were detected with the atmospheric/humidity process. None of the marks by the vacuum process could be observed visually; however, a significant number of marks were detected by fluorescence after BY40 staining. The second trial repeated the same work in trial 1 using the one-step cyanoacrylate process, Lumicyano at a concentration of 4%. Trial 2 provided comparable results to trial 1 and all the items were then re-treated with Lumicyano 4% at atmospheric/humidity conditions before dyeing with BY40 to provide the sequences of process A (Lumicyano 4% atmospheric-Lumicyano 4% atmospheric-BY40) and process B (Lumicyano 4% vacuum-Lumicyano 4% atmospheric-BY40). The number of marks (visual and fluorescent) was counted after each treatment with a substantial increase in the number of detected marks in the second and third treatments of the process. The increased detection rate after the double Lumicyano process was unexpected and may have important implications. Trial 3 was performed to investigate whether the amount of cyanoacrylate and/or fuming time had an impact on the results observed in trial 2 whereas trial 4 assessed if the double process using conventional cyanoacrylate, rather than Lumicyano 4%, provided an increased detection rate. Trials 3 and 4 confirmed that doubling the amount of Lumicyano 4% cyanoacrylate and fuming time produced a lower

Use of Vacuum Degreasing for Precision Cleaning

NASA Technical Reports Server (NTRS)

Fox, Eric; Edwards, Kevin; Mitchell, Mark; Boothe, Richard

2017-01-01

Increasingly strict environmental regulations and the consequent phase out of many effective cleaning solvents has necessitated the development of novel cleaning chemistries and technologies. Among these is vacuum degreasing, a fully enclosed process that eliminates fugitive solvent emissions, thereby reducing cost, environmental, and health related exposure impacts. The effectiveness of vacuum degreasing using modified alcohol for common aerospace contaminants is reported and compared to current and legacy solvents.

Modification of dry grain processing for rice nutrition produced

NASA Astrophysics Data System (ADS)

Rahman, A. N. F.; Genisa, J.; Dirpan, A.; Badani, A. A.

2018-05-01

Rice is a staple food for people in Indonesia that provides high energy and nutrients of up to 360 calories per 100 g. Based on the research it was known that the nutrient content in rice will increased by soaking. This is suspected because the nutrient content in the aleurone layer adsorbed to the endosperm. The purpose of this research was to know the effect of dry grain immersion on the nutrition of rice produced. The method of this research was conducted through some stages: 1. Preparation of raw materials, 2. Grain immersion, 3. Grain drying, 4. Peeling chaff, 5. Testing the nutritional value of rice. The research was processed by using factorial randomized complete random design (RCRD) with three replications. The result showed that soaking the grain for 12 hours has the highest nutritional value increases compared to the control. Proximate test resulted from the best treatment were: protein content of 8.26%, ash content of 0.42% and thiamine content of 0.023%.

Application of Dynamic Speckle Techniques in Monitoring Biofilms Drying Process

NASA Astrophysics Data System (ADS)

Enes, Adilson M.; Júnior, Roberto A. Braga; Dal Fabbro, Inácio M.; da Silva, Washington A.; Pereira, Joelma

2008-04-01

Horticultural crops exhibit losses far greater than grains in Brazil which are associated to inappropriate maturation, mechanical bruising, infestation by microorganisms, wilting, etc. Appropriate packing prevents excessive mass loss associated to transpiration as well as to respiration, by controlling gas exchanging with outside environment. Common packing materials are identified as plastic films, waxes and biofilms. Although research developed with edible films and biopolymers has increased during last years to attend the food industry demands, avoiding environmental problems, little efforts have been reported on biofilm physical properties investigations. These properties, as drying time and biofilm interactions with environment are considered of basic importance. This research work aimed to contribute to development of a methodology to evaluate yucca (Maniot vulgaris) based biofilms drying time supported by a biospeckle technique. Biospeckle is a phenomenon generated by a laser beam scattered on a dynamic active surface, producing a time varying pattern which is proportional to the surface activity level. By capturing and processing the biospeckle image it is possible to attribute a numerical quantity to the surface bioactivity. Materials exhibiting high moisture content will also show high activity, which will support the drying time determination. Tests were set by placing biofilm samples on polyetilen plates and further submitted to laser exposition at four hours interval to capture the pattern images, generating the Intensities Dispersion Modulus. Results indicates that proposed methodology is applicable in determining biofilm drying time as well as vapor losses to environment.