Industrial application of thermal image processing and thermal control

NASA Astrophysics Data System (ADS)

Kong, Lingxue

2001-09-01

Industrial application of infrared thermography is virtually boundless as it can be used in any situations where there are temperature differences. This technology has particularly been widely used in automotive industry for process evaluation and system design. In this work, thermal image processing technique will be introduced to quantitatively calculate the heat stored in a warm/hot object and consequently, a thermal control system will be proposed to accurately and actively manage the thermal distribution within the object in accordance with the heat calculated from the thermal images.

Evaluation of thermal and non-thermal processing effect on non-prebiotic and prebiotic acerola juices using 1H qNMR and GC-MS coupled to chemometrics.

PubMed

Alves Filho, Elenilson G; Silva, Lorena Mara A; de Brito, Edy S; Wurlitzer, Nedio Jair; Fernandes, Fabiano A N; Rabelo, Maria Cristiane; Fonteles, Thatyane V; Rodrigues, Sueli

2018-11-01

The effects of thermal (pasteurization and sterilization) and non-thermal (ultrasound and plasma) processing on the composition of prebiotic and non-prebiotic acerola juices were evaluated using NMR and GC-MS coupled to chemometrics. The increase in the amount of Vitamin C was the main feature observed after thermal processing, followed by malic acid, choline, trigonelline, and acetaldehyde. On the other hand, thermal processing increased the amount of 2-furoic acid, a degradation product from ascorbic acid, as well as influenced the decrease in the amount of esters and alcohols. In general, the non-thermal processing did not present relevant effect on juices composition. The addition of prebiotics (inulin and gluco-oligosaccharides) decreased the effect of processing on juices composition, which suggested a protective effect by microencapsulation. Therefore, chemometric evaluation of the 1 H qNMR and GC-MS dataset was suitable to follow changes in acerola juice under different processing. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of thermal cycling on graphie-fiber-reinforced 6061 aluminum

NASA Technical Reports Server (NTRS)

Dries, G. A.; Tompkins, S. S.

1986-01-01

Graphite-reinforced aluminum alloy metal-matrix composites are among materials being considered for structural components in dimensionally stable space structures. This application requires materials with low values of thermal expansions and high specific stiffnesses. They must remain stable during exposures to the space environment for periods extending to 20 years. The effects of thermal cycling on the thermal expansion behavior and mechanical properties of Thornel P100 graphite 6061 aluminum composites, as fabricated and after thermal processing to eliminate thermal strain hysteresis, have been investigated. Two groups of composites were studied: one was fabricated by hot roll bonding and the other by diffusion bonding. Processing significantly reduced strain hysteresis during thermal cycling in both groups and improved the ultimate tensile strength and modulus in the diffusion-bonded composites. Thermal cycling stabilized the as-fabricated composites by reducing the residual fabrication stress and increased the matrix strength by metallurgical aging. Thermal expansion behavior of both groups after processing was insensitive to thermal cycling. Data scatter was too large to determine effects of thermal cycling on the mechanical properties. The primary effects of processing and thermal cycling can be attributed to changes in the metallurgical condition and stress state of the matrix.

Thermal performance of a photographic laboratory process: Solar Hot Water System

NASA Technical Reports Server (NTRS)

Walker, J. A.; Jensen, R. N.

1982-01-01

The thermal performance of a solar process hot water system is described. The system was designed to supply 22,000 liters (5,500 gallons) per day of 66 C (150 F) process water for photographic processing. The 328 sq m (3,528 sq. ft.) solar field has supplied 58% of the thermal energy for the system. Techniques used for analyzing various thermal values are given. Load and performance factors and the resulting solar contribution are discussed.

Heat transfer phenomena during thermal processing of liquid particulate mixtures-A review.

PubMed

Singh, Anubhav Pratap; Singh, Anika; Ramaswamy, Hosahalli S

2017-05-03

During the past few decades, food industry has explored various novel thermal and non-thermal processing technologies to minimize the associated high-quality loss involved in conventional thermal processing. Among these are the novel agitation systems that permit forced convention in canned particulate fluids to improve heat transfer, reduce process time, and minimize heat damage to processed products. These include traditional rotary agitation systems involving end-over-end, axial, or biaxial rotation of cans and the more recent reciprocating (lateral) agitation. The invention of thermal processing systems with induced container agitation has made heat transfer studies more difficult due to problems in tracking the particle temperatures due to their dynamic motion during processing and complexities resulting from the effects of forced convection currents within the container. This has prompted active research on modeling and characterization of heat transfer phenomena in such systems. This review brings to perspective, the current status on thermal processing of particulate foods, within the constraints of lethality requirements from safety view point, and discusses available techniques of data collection, heat transfer coefficient evaluation, and the critical processing parameters that affect these heat transfer coefficients, especially under agitation processing conditions.

Pulse thermal processing of functional materials using directed plasma arc

DOEpatents

Ott, Ronald D [Knoxville, TN; Blue, Craig A [Knoxville, TN; Dudney, Nancy J [Knoxville, TN; Harper, David C [Kingston, TN

2007-05-22

A method of thermally processing a material includes exposing the material to at least one pulse of infrared light emitted from a directed plasma arc to thermally process the material, the pulse having a duration of no more than 10 s.

Thermal sensors to control polymer forming. Challenge and solutions

NASA Astrophysics Data System (ADS)

Lemeunier, F.; Boyard, N.; Sarda, A.; Plot, C.; Lefèvre, N.; Petit, I.; Colomines, G.; Allanic, N.; Bailleul, J. L.

2017-10-01

Many thermal sensors are already used, for many years, to better understand and control material forming processes, especially polymer processing. Due to technical constraints (high pressure, sealing, sensor dimensions…) the thermal measurement is often performed in the tool or close its surface. Thus, it only gives partial and disturbed information. Having reliable information about the heat flux exchanges between the tool and the material during the process would be very helpful to improve the control of the process and to favor the development of new materials. In this work, we present several sensors developed in labs to study the molding steps in forming processes. The analysis of the obtained thermal measurements (temperature, heat flux) shows the required sensitivity threshold of sensitivity of thermal sensors to be able to detect on-line the rate of thermal reaction. Based on these data, we will present new sensor designs which have been patented.

40 CFR 74.48 - Transfer of allowances from the replacement of thermal energy-process sources. [Reserved

Code of Federal Regulations, 2012 CFR

2012-07-01

... replacement of thermal energy-process sources. [Reserved] 74.48 Section 74.48 Protection of Environment... and Transfer and End of Year Compliance § 74.48 Transfer of allowances from the replacement of thermal energy—process sources. [Reserved] ...

40 CFR 74.48 - Transfer of allowances from the replacement of thermal energy-process sources. [Reserved

Code of Federal Regulations, 2014 CFR

2014-07-01

... replacement of thermal energy-process sources. [Reserved] 74.48 Section 74.48 Protection of Environment... and Transfer and End of Year Compliance § 74.48 Transfer of allowances from the replacement of thermal energy—process sources. [Reserved] ...

40 CFR 74.48 - Transfer of allowances from the replacement of thermal energy-process sources. [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... replacement of thermal energy-process sources. [Reserved] 74.48 Section 74.48 Protection of Environment... and Transfer and End of Year Compliance § 74.48 Transfer of allowances from the replacement of thermal energy—process sources. [Reserved] ...

40 CFR 74.48 - Transfer of allowances from the replacement of thermal energy-process sources. [Reserved

Code of Federal Regulations, 2013 CFR

2013-07-01

... replacement of thermal energy-process sources. [Reserved] 74.48 Section 74.48 Protection of Environment... and Transfer and End of Year Compliance § 74.48 Transfer of allowances from the replacement of thermal energy—process sources. [Reserved] ...

Rapid thermal processing by stamping

DOEpatents

Stradins, Pauls; Wang, Qi

2013-03-05

A rapid thermal processing device and methods are provided for thermal processing of samples such as semiconductor wafers. The device has components including a stamp (35) having a stamping surface and a heater or cooler (40) to bring it to a selected processing temperature, a sample holder (20) for holding a sample (10) in position for intimate contact with the stamping surface; and positioning components (25) for moving the stamping surface and the stamp (35) in and away from intimate, substantially non-pressured contact. Methods for using and making such devices are also provided. These devices and methods allow inexpensive, efficient, easily controllable thermal processing.

Effects of thermal processing by nanofluids on vitamin C, total phenolics and total soluble solids of tomato juice.

PubMed

Jafari, S M; Jabari, S S; Dehnad, D; Shahidi, S A

2017-03-01

In this research, our main idea was to apply thermal processing by nanofluids instead of conventional pasteurization processes, to shorten duration of thermal procedure and improve nutritional contents of fruit juices. Three different variables of temperature (70, 80 and 90 °C), nanofluid concentration (0, 2 and 4%) and time (30, 60 and 90 s) were selected for thermal processing of tomato juices by a shell and tube heat exchanger. The results demonstrated that 4% nanofluid concentration, at 30 °C for 30 s could result in 66% vitamin C retention of fresh juice while it was about 56% for the minimum nanofluid concentration and maximum temperature and time. Higher nanoparticle concentrations made tomato juices that require lowered thermal durations, because of better heat transfer to the product, and total phenolic compounds dwindle less severely; In fact, after 30 s thermal processing at 70 °C with 0 and 4% nanoparticles, total phenolic compounds were maintained by 71.9 and 73.6%, respectively. The range of total soluble solids for processed tomato juices was 5.4-5.6, meaning that nanofluid thermal processing could preserve the natural condition of tomato juices successfully. Based on the indices considered, a nanofluid thermal processing with 4% nanoparticle concentration at the temperature of 70 °C for 30 s will result in the best nutritional contents of final tomato juices.

40 CFR 458.20 - Applicability: description of the carbon black thermal process subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... carbon black thermal process subcategory. 458.20 Section 458.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CARBON BLACK MANUFACTURING POINT SOURCE CATEGORY Carbon Black Thermal Process Subcategory § 458.20 Applicability: description of the carbon black...

Selective thermal oxidation of hydrocarbons in zeolites by oxygen

DOEpatents

Frei, Heinz; Blatter, Fritz; Sun, Hai

2000-01-01

A process for selective thermal oxidation of hydrocarbons adsorbed onto zeolite matrices. A highly selective thermal oxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls is carried out in solvent free zeolites under dark thermal conditions. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts.

Method for thermally spraying crack-free mullite coatings on ceramic-based substrates

NASA Technical Reports Server (NTRS)

Spitsberg, Irene T. (Inventor); Wang, Hongyu (Inventor); Heidorn, Raymond W. (Inventor)

2001-01-01

A process for depositing a mullite coating on a silicon-based material, such as those used to form articles exposed to high temperatures and including the hostile thermal environment of a gas turbine engine. The process is generally to thermally spray a mullite powder to form a mullite layer on a substrate, in which the thermal spraying process is performed so that the mullite powder absorbs a sufficient low level of energy from the thermal source to prevent evaporation of silica from the mullite powder. Processing includes deposition parameter adjustments or annealing to maintain or reestablish phase equilibrium in the mullite layer, so that through-thickness cracks in the mullite layer are avoided.

Method for thermally spraying crack-free mullite coatings on ceramic-based substrates

NASA Technical Reports Server (NTRS)

Spitsberg, Irene T. (Inventor); Wang, Hongyu (Inventor); Heidorn, Raymond W. (Inventor)

2000-01-01

A process for depositing a mullite coating on a silicon-based material, such as those used to form articles exposed to high temperatures and including the hostile thermal environment of a gas turbine engine. The process is generally to thermally spray a mullite powder to form a mullite layer on a substrate, in which the thermal spraying process is performed so that the mullite powder absorbs a sufficient low level of energy from the thermal source to prevent evaporation of silica from the mullite powder. Processing includes deposition parameter adjustments or annealing to maintain or reestablish phase equilibrium in the mullite layer, so that through-thickness cracks in the mullite layer are avoided.

Atmospheric Processing Platform | Photovoltaic Research | NREL

Science.gov Websites

printing units to the left and sample preparation and rapid thermal processing units to the right. In variety of substrates and then further process into optoelectronic materials using rapid thermal , however, occur within a vacuum (i.e., thermal evaporation, sputtering). Samples can remain in ambient

Thermal Stir Welding: A New Solid State Welding Process

NASA Technical Reports Server (NTRS)

Ding, R. Jeffery; Munafo, Paul M. (Technical Monitor)

2002-01-01

Thermal Stir Shielding is a revolutionary new welding process developed at NASA's Marshall Space Flight Center in Huntsville, AL. Thermal stir welding is similar to friction stir welding in that it joins similar or dissimilar materials without melting the parent material. However, unlike friction stir welding, the heating and stirring functions are independent allowing more degrees of freedom for greater process control. This paper introduces the mechanics of the thermal stir welding process. In addition, weld mechanical property data is presented for selected alloys as well as metallurgical analysis.

Thermal processing of food reduces gut microbiota diversity of the host and triggers adaptation of the microbiota: evidence from two vertebrates.

PubMed

Zhang, Zhimin; Li, Dapeng

2018-05-31

Adoption of thermal processing of the diet drives human evolution and gut microbiota diversity changes in a dietary habit-dependent manner. However, whether thermal processing of food triggers gut microbial variation remains unknown. Herein, we compared the microbiota of non-thermally processed and thermally processed food (NF and TF) and investigated gut microbiota associated with NF and TF in catfish Silurus meridionalis and C57BL/6 mice to assess effects of thermal processing of food on gut microbiota and to further identify the differences in host responses. We found no differences in overall microbial composition and structure in the pairwise NF and TF, but identified differential microbial communities between food and gut. Both fish and mice fed TF had significantly lower gut microbial diversity than those fed NF. Moreover, thermal processing of food triggered the changes in their microbial communities. Comparative host studies further indicated host species determined gut microbial assemblies, even if fed with the same food. Fusobacteria was the most abundant phylum in the fish, and Bacteroidetes and Firmicutes dominated in the mice. Besides the consistent reduction of Bacteroidetes and the balanced Protebacteria, the response of other dominated gut microbiota in the fish and mice to TF was taxonomically opposite at the phylum level, and those further found at the genus level. Our results reveal that thermal processing of food strongly contributes to the reduction of gut microbial diversity and differentially drives microbial alterations in a host-dependent manner, suggesting specific adaptations of host-gut microbiota in vertebrates responding to thermal processing of food. These findings open a window of opportunity to understand the decline in gut microbial diversity and the community variation in human evolution and provide new insights into the host-specific microbial assemblages associated with the use of processing techniques in food preparation in humans and domesticated animals.

Inactivation of Byssochlamys nivea ascospores in strawberry puree by high pressure, power ultrasound and thermal processing.

PubMed

Evelyn; Silva, F V M

2015-12-02

Byssochlamys nivea is a mold that can spoil processed fruit products and produce mycotoxins. In this work, high pressure processing (HPP, 600 MPa) and power ultrasound (24 kHz, 0.33 W/mL; TS) in combination with 75°C for the inactivation of four week old B. nivea ascospores in strawberry puree for up to 30 min was investigated and compared with 75°C thermal processing alone. TS and thermal processing can activate the mold ascospores, but HPP-75°C resulted in 2.0 log reductions after a 20 min process. For a 10 min process, HPP-75°C was better than 85°C alone in reducing B. nivea spores (1.4 vs. 0.2 log reduction), demonstrating that a lower temperature in combination with HPP is more effective for spore inactivation than heat alone at a higher temperature. The ascospore inactivation by HPP-thermal, TS and thermal processing was studied at different temperatures and modeled. Faster inactivation was achieved at higher temperatures for all the technologies tested, indicating the significant role of temperature in spore inactivation, alone or combined with other physical processes. The Weibull model described the spore inactivation by 600 MPa HPP-thermal (38, 50, 60, 75°C) and thermal (85, 90°C) processing, whereas the Lorentzian model was more appropriate for TS treatment (65, 70, 75°C). The models obtained provide a useful tool to design and predict pasteurization processes targeting B. nivea ascospores. Copyright © 2015 Elsevier B.V. All rights reserved.

Character of skin on photo-thermal response and its regeneration process using second-harmonic generation microscopy.

PubMed

Wu, Shu-lian; Li, Hui; Zhang, Xiao-man; Chen, Wei R; Wang, Yun-Xia

2014-01-01

Quantitative characterization of skin collagen on photo-thermal response and its regeneration process is an important but difficult task. In this study, morphology and spectrum characteristics of collagen during photo-thermal response and its light-induced remodeling process were obtained by second-harmonic generation microscope in vivo. The texture feature of collagen orientation index and fractal dimension was extracted by image processing. The aim of this study is to detect the information hidden in skin texture during the process of photo-thermal response and its regeneration. The quantitative relations between injured collagen and texture feature were established for further analysis of the injured characteristics. Our results show that it is feasible to determine the main impacts of phototherapy on the skin. It is important to understand the process of collagen remodeling after photo-thermal injuries from texture feature.

A Controlled Agitation Process for Improving Quality of Canned Green Beans during Agitation Thermal Processing.

PubMed

Singh, Anika; Pratap Singh, Anubhav; Ramaswamy, Hosahalli S

2016-06-01

This work introduces the concept of a controlled agitation thermal process to reduce quality damage in liquid-particulate products during agitation thermal processing. Reciprocating agitation thermal processing (RA-TP) was used as the agitation thermal process. In order to reduce the impact of agitation, a new concept of "stopping agitations after sufficient development of cold-spot temperature" was proposed. Green beans were processed in No. 2 (307×409) cans filled with liquids of various consistency (0% to 2% CMC) at various frequencies (1 to 3 Hz) of RA-TP using a full-factorial design and heat penetration results were collected. Corresponding operator's process time to impart a 10-min process lethality (Fo ) and agitation time (AT) were calculated using heat penetration results. Accordingly, products were processed again by stopping agitations as per 3 agitation regimes, namely; full time agitation, equilibration time agitation, and partial time agitation. Processed products were photographed and tested for visual quality, color, texture, breakage of green beans, turbidity, and percentage of insoluble solids in can liquid. Results showed that stopping agitations after sufficient development of cold-spot temperatures is an effective way of reducing product damages caused by agitation (for example, breakage of beans and its leaching into liquid). Agitations till one-log temperature difference gave best color, texture and visual product quality for low-viscosity liquid-particulate mixture and extended agitations till equilibration time was best for high-viscosity products. Thus, it was shown that a controlled agitation thermal process is more effective in obtaining high product quality as compared to a regular agitation thermal process. © 2016 Institute of Food Technologists®

ADR salt pill design and crystal growth process for hydrated magnetic salts

NASA Technical Reports Server (NTRS)

Shirron, Peter J. (Inventor); DiPirro, Michael J. (Inventor); Canavan, Edgar R. (Inventor)

2013-01-01

A process is provided for producing a salt pill for use in very low temperature adiabatic demagnetization refrigerators (ADRs). The method can include providing a thermal bus in a housing. The thermal bus can include an array of thermally conductive metal conductors. A hydrated salt can be grown on the array of thermally conductive metal conductors. Thermal conductance can be provided to the hydrated salt.

21 CFR 113.87 - Operations in the thermal processing room.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Operations in the thermal processing room. 113.87 Section 113.87 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY SEALED...

Development of the GPM Observatory Thermal Vacuum Test Model

NASA Technical Reports Server (NTRS)

Yang, Kan; Peabody, Hume

2012-01-01

A software-based thermal modeling process was documented for generating the thermal panel settings necessary to simulate worst-case on-orbit flight environments in an observatory-level thermal vacuum test setup. The method for creating such a thermal model involved four major steps: (1) determining the major thermal zones for test as indicated by the major dissipating components on the spacecraft, then mapping the major heat flows between these components; (2) finding the flight equivalent sink temperatures for these test thermal zones; (3) determining the thermal test ground support equipment (GSE) design and initial thermal panel settings based on the equivalent sink temperatures; and (4) adjusting the panel settings in the test model to match heat flows and temperatures with the flight model. The observatory test thermal model developed from this process allows quick predictions of the performance of the thermal vacuum test design. In this work, the method described above was applied to the Global Precipitation Measurement (GPM) core observatory spacecraft, a joint project between NASA and the Japanese Aerospace Exploration Agency (JAXA) which is currently being integrated at NASA Goddard Space Flight Center for launch in Early 2014. From preliminary results, the thermal test model generated from this process shows that the heat flows and temperatures match fairly well with the flight thermal model, indicating that the test model can simulate fairly accurately the conditions on-orbit. However, further analysis is needed to determine the best test configuration possible to validate the GPM thermal design before the start of environmental testing later this year. Also, while this analysis method has been applied solely to GPM, it should be emphasized that the same process can be applied to any mission to develop an effective test setup and panel settings which accurately simulate on-orbit thermal environments.

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.

Processing of baby food using pressure-assisted thermal sterilization (PATS) and comparison with thermal treatment

NASA Astrophysics Data System (ADS)

Wang, Yubin; Ismail, Marliya; Farid, Mohammed

2017-10-01

Currently baby food is sterilized using retort processing that gives an extended shelf life. However, this type of heat processing leads to reduction of organoleptic and nutrition value. Alternatively, the combination of pressure and heat could be used to achieve sterilization at reduced temperatures. This study investigates the potential of pressure-assisted thermal sterilization (PATS) technology for baby food sterilization. Here, baby food (apple puree), inoculated with Bacillus subtilis spores was treated using PATS at different operating temperatures, pressures and times and was compared with thermal only treatment. The results revealed that the decimal reduction time of B. subtilis in PATS treatment was lower than that of thermal only treatment. At a similar spore inactivation, the retention of ascorbic acid of PATS-treated sample was higher than that of thermally treated sample. The results indicated that PATS could be a potential technology for baby food processing while minimizing quality deterioration.

Fire suppression as a thermal implosion

NASA Astrophysics Data System (ADS)

Novozhilov, Vasily

2017-01-01

The present paper discusses the possibility of the thermal implosion scenario. This process would be a reverse of the well known thermal explosion (autoignition) phenomenon. The mechanism for thermal implosion scenario is proposed which involves quick suppression of the turbulent diffusion flame. Classical concept of the thermal explosion is discussed first. Then a possible scenario for the reverse process (thermal implosion) is discussed and illustrated by a relevant mathematical model. Based on the arguments presented in the paper, thermal implosion may be observed as an unstable equilibrium point on the generalized Semenov diagram for turbulent flame, however this hypothesis requires ultimate experimental confirmation.

Selective thermal and photooxidation of hydrocarbons in zeolites by oxygen

DOEpatents

Frei, Heinz; Blatter, Fritz; Sun, Hai

1999-01-01

A process for selective thermal oxidation or photooxidation of hydrocarbons adsorbed onto zeolite matrices. A highly selective thermal oxidation and photooxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls in solvent free zeolites under dark thermal conditions or under irradiation with visible light. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts.

21 CFR 500.23 - Thermally processed low-acid foods packaged in hermetically sealed containers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Thermally processed low-acid foods packaged in hermetically sealed containers. 500.23 Section 500.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... Administrative Rulings and Decisions § 500.23 Thermally processed low-acid foods packaged in hermetically sealed...

21 CFR 500.23 - Thermally processed low-acid foods packaged in hermetically sealed containers.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Thermally processed low-acid foods packaged in hermetically sealed containers. 500.23 Section 500.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... Administrative Rulings and Decisions § 500.23 Thermally processed low-acid foods packaged in hermetically sealed...

21 CFR 500.23 - Thermally processed low-acid foods packaged in hermetically sealed containers.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Thermally processed low-acid foods packaged in hermetically sealed containers. 500.23 Section 500.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... Administrative Rulings and Decisions § 500.23 Thermally processed low-acid foods packaged in hermetically sealed...

21 CFR 500.23 - Thermally processed low-acid foods packaged in hermetically sealed containers.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Thermally processed low-acid foods packaged in hermetically sealed containers. 500.23 Section 500.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... Administrative Rulings and Decisions § 500.23 Thermally processed low-acid foods packaged in hermetically sealed...

21 CFR 500.23 - Thermally processed low-acid foods packaged in hermetically sealed containers.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Thermally processed low-acid foods packaged in hermetically sealed containers. 500.23 Section 500.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... Administrative Rulings and Decisions § 500.23 Thermally processed low-acid foods packaged in hermetically sealed...

Corrosion And Thermal Processing In Cold Gas Dynamic Spray Deposited Austenitic Stainless Steel Coatings

DTIC Science & Technology

2016-06-01

Novosibirsk during the 1980s [14]. In this process, particles of the coating material are accelerated by entrainment in a supersonic jet of gas ...THERMAL PROCESSING IN COLD GAS DYNAMIC SPRAY DEPOSITED AUSTENITIC STAINLESS STEEL COATINGS by John A Luhn June 2016 Thesis Advisor: Sarath...REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE CORROSION AND THERMAL PROCESSING IN COLD GAS DYNAMIC SPRAY DEPOSITED AUSTENITIC

Selective thermal and photooxidation of hydrocarbons in zeolites by oxygen

DOEpatents

Frei, H.; Blatter, F.; Sun, H.

1999-06-22

A process is described for selective thermal oxidation or photooxidation of hydrocarbons adsorbed onto zeolite matrices. A highly selective thermal oxidation and photooxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls in solvent free zeolites under dark thermal conditions or under irradiation with visible light. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts. 19 figs.

Selective thermal and photooxidation of hydrocarbons in zeolites by oxygen

DOEpatents

Frei, Heinz; Blatter, Fritz; Sun, Hai

2001-01-01

A process for a combined selective thermal oxidation and photooxidation of hydrocarbons adsorbed onto zeolite matrices. A highly combined selective thermal oxidation and photooxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls in solvent free zeolites under dark thermal conditions or under irradiation with visible light. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts.

Integrating Thermal Tools Into the Mechanical Design Process

NASA Technical Reports Server (NTRS)

Tsuyuki, Glenn T.; Siebes, Georg; Novak, Keith S.; Kinsella, Gary M.

1999-01-01

The intent of mechanical design is to deliver a hardware product that meets or exceeds customer expectations, while reducing cycle time and cost. To this end, an integrated mechanical design process enables the idea of parallel development (concurrent engineering). This represents a shift from the traditional mechanical design process. With such a concurrent process, there are significant issues that have to be identified and addressed before re-engineering the mechanical design process to facilitate concurrent engineering. These issues also assist in the integration and re-engineering of the thermal design sub-process since it resides within the entire mechanical design process. With these issues in mind, a thermal design sub-process can be re-defined in a manner that has a higher probability of acceptance, thus enabling an integrated mechanical design process. However, the actual implementation is not always problem-free. Experience in applying the thermal design sub-process to actual situations provides the evidence for improvement, but more importantly, for judging the viability and feasibility of the sub-process.

Optical processing for semiconductor device fabrication

NASA Technical Reports Server (NTRS)

Sopori, Bhushan L.

1994-01-01

A new technique for semiconductor device processing is described that uses optical energy to produce local heating/melting in the vicinity of a preselected interface of the device. This process, called optical processing, invokes assistance of photons to enhance interface reactions such as diffusion and melting, as compared to the use of thermal heating alone. Optical processing is performed in a 'cold wall' furnace, and requires considerably lower energies than furnace or rapid thermal annealing. This technique can produce some device structures with unique properties that cannot be produced by conventional thermal processing. Some applications of optical processing involving semiconductor-metal interfaces are described.

Thermochemical water decomposition. [hydrogen separation for energy applications

NASA Technical Reports Server (NTRS)

Funk, J. E.

1977-01-01

At present, nearly all of the hydrogen consumed in the world is produced by reacting hydrocarbons with water. As the supply of hydrocarbons diminishes, the problem of producing hydrogen from water alone will become increasingly important. Furthermore, producing hydrogen from water is a means of energy conversion by which thermal energy from a primary source, such as solar or nuclear fusion of fission, can be changed into an easily transportable and ecologically acceptable fuel. The attraction of thermochemical processes is that they offer the potential for converting thermal energy to hydrogen more efficiently than by water electrolysis. A thermochemical hydrogen-production process is one which requires only water as material input and mainly thermal energy, or heat, as an energy input. Attention is given to a definition of process thermal efficiency, the thermodynamics of the overall process, the single-stage process, the two-stage process, multistage processes, the work of separation and a process evaluation.

Thermal storage technologies for solar industrial process heat applications

NASA Technical Reports Server (NTRS)

Gordon, L. H.

1979-01-01

The state-of-the-art of thermal storage subsystems for the intermediate and high temperature (100 C to 600 C) solar industrial process heat generation is presented. Primary emphasis is focused on buffering and diurnal storage as well as total energy transport. In addition, advanced thermal storage concepts which appear promising for future solar industrial process heat applications are discussed.

Method of thermally processing superplastically formed aluminum-lithium alloys to obtain optimum strengthening

NASA Technical Reports Server (NTRS)

Anton, Claire E. (Inventor)

1993-01-01

Optimum strengthening of a superplastically formed aluminum-lithium alloy structure is achieved via a thermal processing technique which eliminates the conventional step of solution heat-treating immediately following the step of superplastic forming of the structure. The thermal processing technique involves quenching of the superplastically formed structure using static air, forced air or water quenching.

Thermal Spray Maps: Material Genomics of Processing Technologies

NASA Astrophysics Data System (ADS)

Ang, Andrew Siao Ming; Sanpo, Noppakun; Sesso, Mitchell L.; Kim, Sun Yung; Berndt, Christopher C.

2013-10-01

There is currently no method whereby material properties of thermal spray coatings may be predicted from fundamental processing inputs such as temperature-velocity correlations. The first step in such an important understanding would involve establishing a foundation that consolidates the thermal spray literature so that known relationships could be documented and any trends identified. This paper presents a method to classify and reorder thermal spray data so that relationships and correlations between competing processes and materials can be identified. Extensive data mining of published experimental work was performed to create thermal spray property-performance maps, known as "TS maps" in this work. Six TS maps will be presented. The maps are based on coating characteristics of major importance; i.e., porosity, microhardness, adhesion strength, and the elastic modulus of thermal spray coatings.

Elements for the modeling of the thermal process in heating furnaces for steel forming

NASA Astrophysics Data System (ADS)

Constantinescu, D.; Carlan, A. B.

2017-02-01

In the present paper, by “modelling of thermal process” will be understood the thermal techniques modelling, applied to the heating of steel billets in a large scale, in view of processing by forming. These technologies are correlated with the particularities of the thermal aggregates, having as main objective the reducing of energy consumptions and the optimizing of the aggregate design. When heating the steel billets in view of processing by forming, the duration and the quality of heating are influenced by the modality that the billets are receiving the thermal flow. The reception of the thermal flow depends on the heated surface exposed to the thermal radiation in compliance with their position on the hearth of the heating aggregate. The present paper intends to establish some parameters in view of optimizing the heating process. A basic point of the work is also the determination of some components of a mathematical model for the proposed heating technology. The authors have in view the complexity of the technical evolutions of the furnaces.

Hazardous waste characterization among various thermal processes in South Korea: a comparative analysis.

PubMed

Shin, Sun Kyoung; Kim, Woo-Il; Jeon, Tae-Wan; Kang, Young-Yeul; Jeong, Seong-Kyeong; Yeon, Jin-Mo; Somasundaram, Swarnalatha

2013-09-15

Ministry of Environment, Republic of Korea (South Korea) is in progress of converting its current hazardous waste classification system to harmonize it with the international standard and to set-up the regulatory standards for toxic substances present in the hazardous waste. In the present work, the concentrations along with the trend of 13 heavy metals, F(-), CN(-) and 19 PAH present in the hazardous waste generated among various thermal processes (11 processes) in South Korea were analyzed along with their leaching characteristics. In all thermal processes, the median concentrations of Cu (3.58-209,000 mg/kg), Ni (BDL-1560 mg/kg), Pb (7.22-5132.25mg/kg) and Zn (83.02-31419 mg/kg) were comparatively higher than the other heavy metals. Iron & Steel thermal process showed the highest median value of the heavy metals Cd (14.76 mg/kg), Cr (166.15 mg/kg) and Hg (2.38 mg/kg). Low molecular weight PAH (BDL-37.59 mg/kg) was predominant in sludge & filter cake samples present in most of the thermal processes. Comparatively flue gas dust present in most of the thermal processing units resulted in the higher leaching of the heavy metals. Copyright © 2013 Elsevier B.V. All rights reserved.

Perspective of Micro Process Engineering for Thermal Food Treatment

PubMed Central

Mathys, Alexander

2018-01-01

Micro process engineering as a process synthesis and intensification tool enables an ultra-short thermal treatment of foods within milliseconds (ms) using very high surface-area-to-volume ratios. The innovative application of ultra-short pasteurization and sterilization at high temperatures, but with holding times within the range of ms would allow the preservation of liquid foods with higher qualities, thereby avoiding many unwanted reactions with different temperature–time characteristics. Process challenges, such as fouling, clogging, and potential temperature gradients during such conditions need to be assessed on a case by case basis and optimized accordingly. Owing to the modularity, flexibility, and continuous operation of micro process engineering, thermal processes from the lab to the pilot and industrial scales can be more effectively upscaled. A case study on thermal inactivation demonstrated the feasibility of transferring lab results to the pilot scale. It was shown that micro process engineering applications in thermal food treatment may be relevant to both research and industrial operations. Scaling of micro structured devices is made possible through the use of numbering-up approaches; however, reduced investment costs and a hygienic design must be assured. PMID:29686990

Net positive energy wastewater treatment plant via thermal pre-treatment of sludge: A theoretical case study.

PubMed

Farno, Ehsan; Baudez, Jean Christophe; Parthasarathy, Rajarathinam; Eshtiaghi, Nicky

2017-04-16

In a wastewater treatment process, energy is mainly used in sludge handling and heating, while energy is recovered by biogas production in anaerobic digestion process. Thermal pre-treatment of sludge can change the energy balance in a wastewater treatment process since it reduces the viscosity and yield stress of sludge and increases the biogas production. In this study, a calculation based on a hypothetical wastewater treatment plant is provided to show the possibility of creating a net positive energy wastewater treatment plant as a result of implementing thermal pre-treatment process before the anaerobic digester. The calculations showed a great energy saving in pumping and mixing of the sludge by thermal pre-treatment of sludge before anaerobic digestion process.

Identifying thermal breakdown products of thermoplastics.

PubMed

Guillemot, Marianne; Oury, Benoît; Melin, Sandrine

2017-07-01

Polymers processed to produce plastic articles are subjected to temperatures between 150°C and 450°C or more during overheated processing and breakdowns. Heat-based processing of this nature can lead to emission of volatile organic compounds (VOCs) into the thermoplastic processing shop. In this study, laboratory experiments, qualitative and quantitative emissions measurement in thermoplastic factories were carried out. The first step was to identify the compounds released depending on the thermoplastic nature, the temperature and the type of process. Then a thermal degradation protocol that can extrapolate the laboratory results to industry scenarios was developed. The influence of three parameters on released thermal breakdown products was studied: the sample preparation methods-manual cutting, ambient, or cold grinding-the heating rate during thermal degradation-5, 10 20, and 50°C/min-and the decomposition method-thermogravimetric analysis and pyrolysis. Laboratory results were compared to atmospheric measurements taken at 13 companies to validate the protocol and thereby ensure its representativeness of industrial thermal processing. This protocol was applied to most commonly used thermoplastics to determine their thermal breakdown products and their thermal behaviour. Emissions data collected by personal exposure monitoring and sampling at the process emission area show airborne concentrations of detected compounds to be in the range of 0-3 mg/m 3 under normal operating conditions. Laser cutting or purging operations generate higher pollution levels in particular formaldehyde which was found in some cases at a concentration above the workplace exposure limit.

Effect of thermal processing on astaxanthin and astaxanthin esters in pacific white shrimp Litopenaeus vannamei.

PubMed

Yang, Shu; Zhou, Qingxin; Yang, Lu; Xue, Yong; Xu, Jie; Xue, Changhu

2015-01-01

The red color of processed shrimp, one of the most attractive attributes and an important criterion for consumers, is often limited by thermal processing (microwaving, boiling and frying), due to astaxanthin degradation. The effect of thermal processing on astaxanthin in Pacific white shrimp (Litopenaeus vannamei) were investigated. A High-performance liquid chromatographic - atmospheric pressure chemical ionization mass spectrometry (LC-(APCI)-MS/MS) method was used to identify and quantify all-trans- and cis-isomers of astaxanthin, and molecular species of astaxanthin esters in fresh and thermal processed shrimps. Total astaxanthin loss ranged from 7.99% to 52.01% in first 3 min under three thermal processing. All-trans-astaxanthin was most affected, with a reduction from 32.81 to 8.72 μg kg(-1), while 13-cis-astxanthin had a rise (from 2.38 to 4.58 μg kg(-1)). Esterified astaxanthin was shown to hydrolyze and degrade, furthermore astaxanthin diesters had a better thermostability compare to astaxanthin monoesters. Astaxanthin monoesters with eicosapntemacnioc acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6), had a lower thermal stability than those with saturated fatty acids, however, it was the opposite of astaxanthin diesters. The findings suggested that the method of thermal processing should be carefully used in the manufacturing and domestic cooking of shrimps. The results also could be useful in calculating the dietary intake of astaxanthin and in assessing astaxanthin profiles and contents of shrimp containing products.

Thermal behavior of copper processed by ECAP at elevated temperatures

NASA Astrophysics Data System (ADS)

Gonda, Viktor

2018-05-01

Large amount of strengthening can be achieved by equal channel angular pressing (ECAP), by the applied severe plastic deformation during the processing. For pure metals, this high strength is accompanied with low thermal stability due to the large activation energy for recrystallization. In the present paper, the chosen technological route was elevated temperature single pass ECAP processing of copper, and its effect on the thermal behavior during the restoration processes of the deformed samples was studied.

Shelf-stable egg-based products processed by high pressure thermal sterilization

USDA-ARS?s Scientific Manuscript database

Producing a thermally sterilized egg-based product with increased shelf life without losing the sensory and nutritional properties of the freshly prepared product is challenging. Until recently, all commercial shelf-stable egg-based products were sterilized using conventional thermal processing; how...

Using ultrasound technology for the inactivation and thermal sensitization of peroxidase in green coconut water.

PubMed

Rojas, Meliza Lindsay; Trevilin, Júlia Hellmeister; Funcia, Eduardo Dos Santos; Gut, Jorge Andrey Wilhelms; Augusto, Pedro Esteves Duarte

2017-05-01

Green coconut water has unique nutritional and sensorial qualities. Despite the different technologies already studied, its enzymatic stability is still challenging. This study evaluated the use of ultrasound technology (US) for inactivating/sensitizing coconut water peroxidase (POD). The effect of both US application alone and as a pre-treatment to thermal processing was evaluated. The enzyme activity during US processing was reduced 27% after 30min (286W/L, 20kHz), demonstrating its high resistance. The thermal inactivation was described by the Weibull model under non-isothermal conditions. The enzyme became sensitized to heat after US pre-treatment. Further, the use of US resulted in more uniform heat resistance. The results suggest that US is a good technology for sensitizing enzymes before thermal processing (even for an enzyme with high thermal resistance). Therefore, the use of this technology could decrease the undesirable effects of long times and/or the high temperatures of the conventional thermal processing. Copyright © 2016 Elsevier B.V. All rights reserved.

Engineering Analysis of Thermal-Load Components in the Process of Heating of Pet Preforms

NASA Astrophysics Data System (ADS)

Sidorov, D. É.; Kolosov, A. E.; Kazak, I. A.; Pogorelyi, A. V.

2018-05-01

The influence of thermal-load components (convection, collimated and uncollimated components of infrared radiation) in the process of production of PET packaging on the heating of PET preforms has been assessed. It has been established that the collimated component of infrared radiation ensures most (up to 70%) of the thermal energy in the process of heating of a PET preform.

Thermal Curing Process Monitoring of the Composite Material Using the FBG sensor

NASA Astrophysics Data System (ADS)

Zhang, Youhong; Chang, Xinlong; Zhang, Xiaojun; He, Xiangyong

2018-03-01

The raw composite material will suffer complex chemical and morphological changes during the thermal curing process, and it is difficult to monitor the curing process and curing effect. In this paper, the FBG sensor was embedded in the raw composite material to monitor the whole curing process. The experiment results showed that the FBG sensor can monitor the resin transformation and residual deformation of the composite material, and the FBG sensor can be applied to monitor the thermal curing process of the composite structure.

9 CFR 318.302 - Thermal processing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 318.302 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY... Canning and Canned Products § 318.302 Thermal processing. (a) Process schedules. Prior to the processing...

Efficient development and processing of thermal math models of very large space truss structures

NASA Technical Reports Server (NTRS)

Warren, Andrew H.; Arelt, Joseph E.; Lalicata, Anthony L.

1993-01-01

As the spacecraft moves along the orbit, the truss members are subjected to direct and reflected solar, albedo and planetary infra-red (IR) heating rates, as well as IR heating and shadowing from other spacecraft components. This is a transient process with continuously changing heating loads and the shadowing effects. The resulting nonuniform temperature distribution may cause nonuniform thermal expansion, deflection and stress in the truss elements, truss warping and thermal distortions. There are three challenges in the thermal-structural analysis of the large truss structures. The first is the development of the thermal and structural math models, the second - model processing, and the third - the data transfer between the models. All three tasks require considerable time and computer resources to be done because of a very large number of components involved. To address these challenges a series of techniques of automated thermal math modeling and efficient processing of very large space truss structures were developed. In the process the finite element and finite difference methods are interfaced. A very substantial reduction of the quantity of computations was achieved while assuring a desired accuracy of the results. The techniques are illustrated on the thermal analysis of a segment of the Space Station main truss.

Data Processing of LAPAN-A3 Thermal Imager

NASA Astrophysics Data System (ADS)

Hartono, R.; Hakim, P. R.; Syafrudin, AH

2018-04-01

As an experimental microsatellite, LAPAN-A3/IPB satellite has an experimental thermal imager, which is called as micro-bolometer, to observe earth surface temperature for horizon observation. The imager data is transmitted from satellite to ground station by S-band video analog signal transmission, and then processed by ground station to become sequence of 8-bit enhanced and contrasted images. Data processing of LAPAN-A3/IPB thermal imager is more difficult than visual digital camera, especially for mosaic and classification purpose. This research aims to describe simple mosaic and classification process of LAPAN-A3/IPB thermal imager based on several videos data produced by the imager. The results show that stitching using Adobe Photoshop produces excellent result but can only process small area, while manual approach using ImageJ software can produce a good result but need a lot of works and time consuming. The mosaic process using image cross-correlation by Matlab offers alternative solution, which can process significantly bigger area in significantly shorter time processing. However, the quality produced is not as good as mosaic images of the other two methods. The simple classifying process that has been done shows that the thermal image can classify three distinct objects, i.e.: clouds, sea, and land surface. However, the algorithm fail to classify any other object which might be caused by distortions in the images. All of these results can be used as reference for development of thermal imager in LAPAN-A4 satellite.

The edge detection method of the infrared imagery of the laser spot

NASA Astrophysics Data System (ADS)

Che, Jinxi; Zhang, Jinchun; Li, Zhongmin

2016-01-01

In the jamming effectiveness experiments, in which the thermal infrared imager was interfered by the CO2 Laser, in order to evaluate the jamming effect of the thermal infrared imager by the CO2 Laser, it was needed to analyses the obtained infrared imagery of laser spot. Because the laser spot pictures obtained from the thermal infrared imager are irregular, the edge detection is an important process. The image edge is one of the most basic characteristics of the image, and it contains most of the information of the image. Generally, because of the thermal balance effect, the partly temperature of objective is no quite difference; therefore the infrared imagery's ability of reflecting the local detail of object is obvious week. At the same time, when the information of heat distribution of the thermal imagery was combined with the basic information of target, such as the object size, the relative position of field of view, shape and outline, and so on, the information just has more value. Hence, it is an important step for making image processing to extract the objective edge of the infrared imagery. Meanwhile it is an important part of image processing procedure and it is the premise of many subsequent processing. So as to extract outline information of the target from the original thermal imagery, and overcome the disadvantage, such as the low image contrast of the image and serious noise interference, and so on, the edge of thermal imagery needs detecting and processing. The principles of the Roberts, Sobel, Prewitt and Canny operator were analyzed, and then they were used to making edge detection on the thermal imageries of laser spot, which were obtained from the jamming effect experiments of CO2 laser jamming the thermal infrared imager. On the basis of the detection result, their performances were compared. At the end, the characteristics of the operators were summarized, which provide reference for the choice of edge detection operators in thermal imagery processing in future.

Deconstructing Temperature Gradients across Fluid Interfaces: The Structural Origin of the Thermal Resistance of Liquid-Vapor Interfaces

NASA Astrophysics Data System (ADS)

Muscatello, Jordan; Chacón, Enrique; Tarazona, Pedro; Bresme, Fernando

2017-07-01

The interfacial thermal resistance determines condensation-evaporation processes and thermal transport across material-fluid interfaces. Despite its importance in transport processes, the interfacial structure responsible for the thermal resistance is still unknown. By combining nonequilibrium molecular dynamics simulations and interfacial analyses that remove the interfacial thermal fluctuations we show that the thermal resistance of liquid-vapor interfaces is connected to a low density fluid layer that is adsorbed at the liquid surface. This thermal resistance layer (TRL) defines the boundary where the thermal transport mechanism changes from that of gases (ballistic) to that characteristic of dense liquids, dominated by frequent particle collisions involving very short mean free paths. We show that the thermal conductance is proportional to the number of atoms adsorbed in the TRL, and hence we explain the structural origin of the thermal resistance in liquid-vapor interfaces.

Study on processing immiscible materials in zero gravity

NASA Technical Reports Server (NTRS)

Reger, J. L.; Mendelson, R. A.

1975-01-01

An experimental investigation was conducted to evaluate mixing immiscible metal combinations under several process conditions. Under one-gravity, these included thermal processing, thermal plus electromagnetic mixing, and thermal plus acoustic mixing. The same process methods were applied during free fall on the MSFC drop tower facility. The design is included of drop tower apparatus to provide the electromagnetic and acoustic mixing equipment, and a thermal model was prepared to design the specimen and cooling procedure. Materials systems studied were Ca-La, Cd-Ga and Al-Bi; evaluation of the processed samples included the morphology and electronic property measurements. The morphology was developed using optical and scanning electron microscopy and microprobe analyses. Electronic property characterization of the superconducting transition temperatures were made using an impedance change-tuned coil method.

Crack-free conditions in welding of glass by ultrashort laser pulse.

PubMed

Miyamoto, Isamu; Cvecek, Kristian; Schmidt, Michael

2013-06-17

The spatial distribution of the laser energy absorbed by nonlinear absorption process in bulk glass w(z) is determined and thermal cycles due to the successive ultrashort laser pulse (USLP) is simulated using w(z) based on the transient thermal conduction model. The thermal stress produced in internal melting of bulk glass by USLP is qualitatively analyzed based on a simple thermal stress model, and crack-free conditions are studied in glass having large coefficient of thermal expansion. In heating process, cracks are prevented when the laser pulse impinges into glass with temperatures higher than the softening temperature of glass. In cooling process, shrinkage stress is suppressed to prevent cracks, because the embedded molten pool produced by nonlinear absorption process behaves like an elastic body under the compressive stress field unlike the case of CW-laser welding where the molten pool having a free surface produced by linear absorption process is plastically deformed under the compressive stress field.

Thermal control system. [removing waste heat from industrial process spacecraft

NASA Technical Reports Server (NTRS)

Hewitt, D. R. (Inventor)

1983-01-01

The temperature of an exothermic process plant carried aboard an Earth orbiting spacecraft is regulated using a number of curved radiator panels accurately positioned in a circular arrangement to form an open receptacle. A module containing the process is insertable into the receptacle. Heat exchangers having broad exterior surfaces extending axially above the circumference of the module fit within arcuate spacings between adjacent radiator panels. Banks of variable conductance heat pipes partially embedded within and thermally coupled to the radiator panels extend across the spacings and are thermally coupled to broad exterior surfaces of the heat exchangers by flanges. Temperature sensors monitor the temperature of process fluid flowing from the module through the heat exchanges. Thermal conduction between the heat exchangers and the radiator panels is regulated by heating a control fluid within the heat pipes to vary the effective thermal length of the heat pipes in inverse proportion to changes in the temperature of the process fluid.

Impact of thermal processing on the activity of gallotannins and condensed tannins from Hamamelis virginiana used as functional ingredients in seafood.

PubMed

González, María Jesús; Torres, Josep Lluís; Medina, Isabel

2010-04-14

Phenolic extracts from witch hazel, Hamamelis virginiana, are efficient antioxidants against fish lipid peroxidation. The impact of fish thermal processes on the hydrolyzable polyphenols from this source was studied. H. virginiana polyphenols included 80% of hydrolyzable tannins, characterized by a mixture of glucose gallates containing from 5 to 10 units of gallic acid, hamamelitannin, and 20% of proanthocyanidins. Structural modifications of the polyphenols during thermal processes were determined by HPLC-MS. Changes in their reducing and free radical scavenging capacities as a result of high temperatures were also determined. Thermal processes triggered a significant breakdown of hydrolyzable tannins with 6-10 galloyl units to give pentagalloyl glucose (PGG). The release of high concentrations of free gallic acid especially in long-term thermally processed samples leads to an increase of the antioxidant ability of heated H. virginiana extracts. Such an increase was evidenced by an increment in the reducing and radical scavenging capacities as well as an improvement in the antioxidant effectiveness for inhibiting lipid oxidation of processed fatty fish muscle.

Significant improvement in the thermal annealing process of optical resonators

NASA Astrophysics Data System (ADS)

Salzenstein, Patrice; Zarubin, Mikhail

2017-05-01

Thermal annealing performed during process improves the quality of the roughness of optical resonators reducing stresses at the periphery of their surface thus allowing higher Q-factors. After a preliminary realization, the design of the oven and the electronic method were significantly improved thanks to nichrome resistant alloy wires and chopped basalt fibers for thermal isolation during the annealing process. Q-factors can then be improved.

The study of thermal processes in control systems of heat consumption of buildings

NASA Astrophysics Data System (ADS)

Tsynaeva, E.; A, Tsynaeva

2017-11-01

The article discusses the main thermal processes in the automated control systems for heat consumption (ACSHC) of buildings, schematic diagrams of these systems, mathematical models used for description of thermal processes in ACSHC. Conducted verification represented by mathematical models. It was found that the efficiency of the operation of ACSHC depend from the external and internal factors. Numerical study of dynamic modes of operation of ACSHC.

A numerical study of EGS heat extraction process based on a thermal non-equilibrium model for heat transfer in subsurface porous heat reservoir

NASA Astrophysics Data System (ADS)

Chen, Jiliang; Jiang, Fangming

2016-02-01

With a previously developed numerical model, we perform a detailed study of the heat extraction process in enhanced or engineered geothermal system (EGS). This model takes the EGS subsurface heat reservoir as an equivalent porous medium while it considers local thermal non-equilibrium between the rock matrix and the fluid flowing in the fractured rock mass. The application of local thermal non-equilibrium model highlights the temperature-difference heat exchange process occurring in EGS reservoirs, enabling a better understanding of the involved heat extraction process. The simulation results unravel the mechanism of preferential flow or short-circuit flow forming in homogeneously fractured reservoirs of different permeability values. EGS performance, e.g. production temperature and lifetime, is found to be tightly related to the flow pattern in the reservoir. Thermal compensation from rocks surrounding the reservoir contributes little heat to the heat transmission fluid if the operation time of an EGS is shorter than 15 years. We find as well the local thermal equilibrium model generally overestimates EGS performance and for an EGS with better heat exchange conditions in the heat reservoir, the heat extraction process acts more like the local thermal equilibrium process.

Passive Thermal Management for a Fuel Cell Reforming Process

DTIC Science & Technology

2006-06-01

American Institute of Aeronautics and Astronautics 1 PASSIVE THERMAL MANAGEMENT FOR A FUEL CELL REFORMING PROCESS David B. Sarraf * and...REPORT DATE JUN 2006 2. REPORT TYPE 3. DATES COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE Passive Thermal Management for a Fuel Cell

Evaluation of stabilization techniques for ion implant processing

NASA Astrophysics Data System (ADS)

Ross, Matthew F.; Wong, Selmer S.; Minter, Jason P.; Marlowe, Trey; Narcy, Mark E.; Livesay, William R.

1999-06-01

With the integration of high current ion implant processing into volume CMOS manufacturing, the need for photoresist stabilization to achieve a stable ion implant process is critical. This study compares electron beam stabilization, a non-thermal process, with more traditional thermal stabilization techniques such as hot plate baking and vacuum oven processing. The electron beam processing is carried out in a flood exposure system with no active heating of the wafer. These stabilization techniques are applied to typical ion implant processes that might be found in a CMOS production process flow. The stabilization processes are applied to a 1.1 micrometers thick PFI-38A i-line photoresist film prior to ion implant processing. Post stabilization CD variation is detailed with respect to wall slope and feature integrity. SEM photographs detail the effects of the stabilization technique on photoresist features. The thermal stability of the photoresist is shown for different levels of stabilization and post stabilization thermal cycling. Thermal flow stability of the photoresist is detailed via SEM photographs. A significant improvement in thermal stability is achieved with the electron beam process, such that photoresist features are stable to temperatures in excess of 200 degrees C. Ion implant processing parameters are evaluated and compared for the different stabilization methods. Ion implant system end-station chamber pressure is detailed as a function of ion implant process and stabilization condition. The ion implant process conditions are detailed for varying factors such as ion current, energy, and total dose. A reduction in the ion implant systems end-station chamber pressure is achieved with the electron beam stabilization process over the other techniques considered. This reduction in end-station chamber pressure is shown to provide a reduction in total process time for a given ion implant dose. Improvements in the ion implant process are detailed across several combinations of current and energy.

Radiation Pressure Cooling as a Quantum Dynamical Process

NASA Astrophysics Data System (ADS)

He, Bing; Yang, Liu; Lin, Qing; Xiao, Min

2017-06-01

One of the most fundamental problems in optomechanical cooling is how small the thermal phonon number of a mechanical oscillator can be achieved under the radiation pressure of a proper cavity field. Different from previous theoretical predictions, which were based on an optomechanical system's time-independent steady states, we treat such cooling as a dynamical process of driving the mechanical oscillator from its initial thermal state, due to its thermal equilibrium with the environment, to a stabilized quantum state of higher purity. We find that the stabilized thermal phonon number left in the end actually depends on how fast the cooling process could be. The cooling speed is decided by an effective optomechanical coupling intensity, which constitutes an essential parameter for cooling, in addition to the sideband resolution parameter that has been considered in other theoretical studies. The limiting thermal phonon number that any cooling process cannot surpass exhibits a discontinuous jump across a certain value of the parameter.

Thermoreflectance spectroscopy—Analysis of thermal processes in semiconductor lasers

NASA Astrophysics Data System (ADS)

Pierścińska, D.

2018-01-01

This review focuses on theoretical foundations, experimental implementation and an overview of experimental results of the thermoreflectance spectroscopy as a powerful technique for temperature monitoring and analysis of thermal processes in semiconductor lasers. This is an optical, non-contact, high spatial resolution technique providing high temperature resolution and mapping capabilities. Thermoreflectance is a thermometric technique based on measuring of relative change of reflectivity of the surface of laser facet, which provides thermal images useful in hot spot detection and reliability studies. In this paper, principles and experimental implementation of the technique as a thermography tool is discussed. Some exemplary applications of TR to various types of lasers are presented, proving that thermoreflectance technique provides new insight into heat management problems in semiconductor lasers and in particular, that it allows studying thermal degradation processes occurring at laser facets. Additionally, thermal processes and basic mechanisms of degradation of the semiconductor laser are discussed.

Anticancer activity of Nigella sativa (black seed) and its relationship with the thermal processing and quinone composition of the seed.

PubMed

Agbaria, Riad; Gabarin, Adi; Dahan, Arik; Ben-Shabat, Shimon

2015-01-01

The traditional preparation process of Nigella sativa (NS) oil starts with roasting of the seeds, an allegedly unnecessary step that was never skipped. The aims of this study were to investigate the role and boundaries of thermal processing of NS seeds in the preparation of therapeutic extracts and to elucidate the underlying mechanism. NS extracts obtained by various seed thermal processing methods were investigated in vitro for their antiproliferative activity in mouse colon carcinoma (MC38) cells and for their thymoquinone content. The effect of the different methods of thermal processing on the ability of the obtained NS oil to inhibit the nuclear factor kappa B (NF-κB) pathway was then investigated in Hodgkin's lymphoma (L428) cells. The different thermal processing protocols yielded three distinct patterns: heating the NS seeds to 50°C, 100°C, or 150°C produced oil with a strong ability to inhibit tumor cell growth; no heating or heating to 25°C had a mild antiproliferative effect; and heating to 200°C or 250°C had no effect. Similar patterns were obtained for the thymoquinone content of the corresponding oils, which showed an excellent correlation with the antiproliferative data. It is proposed that there is an oxidative transition mechanism between quinones after controlled thermal processing of the seeds. While NS oil from heated seeds delayed the expression of NF-κB transcription, non-heated seeds resulted in only 50% inhibition. The data indicate that controlled thermal processing of NS seeds (at 50°C-150°C) produces significantly higher anticancer activity associated with a higher thymoquinone oil content, and inhibits the NF-κB signaling pathway.

Thermal energy storage – overview and specific insight into nitrate salts for sensible and latent heat storage

PubMed Central

Bauer, Thomas; Martin, Claudia; Eck, Markus; Wörner, Antje

2015-01-01

Summary Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems. PMID:26199853

Thermal energy storage - overview and specific insight into nitrate salts for sensible and latent heat storage.

PubMed

Pfleger, Nicole; Bauer, Thomas; Martin, Claudia; Eck, Markus; Wörner, Antje

2015-01-01

Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems.

Compressive behavior of laminated neoprene bridge bearing pads under thermal aging condition

NASA Astrophysics Data System (ADS)

Jun, Xie; Zhang, Yannian; Shan, Chunhong

2017-10-01

The present study was conducted to obtain a better understanding of the variation rule of mechanical properties of laminated neoprene bridge bearing pads under thermal aging condition using compression tests. A total of 5 specimens were processed in a high-temperature chamber. After that, the specimens were tested subjected to axial load. The parameter mainly considered time of thermal aging processing for specimens. The results of compression tests show that the specimens after thermal aging processing are more probably brittle failure than the standard specimen. Moreover, the exposure of steel plate, cracks and other failure phenomena are more serious than the standard specimen. The compressive capacity, ultimate compressive strength, compressive elastic modulus of the laminated neoprene bridge bearing pads decreased dramatically with the increasing in the aging time of thermal aging processing. The attenuation trends of ultimate compressive strength, compressive elastic modulus of laminated neoprene bridge bearing pads under thermal aging condition accord with power function. The attenuation models are acquired by regressing data of experiment with the least square method. The attenuation models conform to reality well which shows that this model is applicable and has vast prospect in assessing the performance of laminated neoprene bridge bearing pads under thermal aging condition.

Controllable laser thermal cleavage of sapphire wafers

NASA Astrophysics Data System (ADS)

Xu, Jiayu; Hu, Hong; Zhuang, Changhui; Ma, Guodong; Han, Junlong; Lei, Yulin

2018-03-01

Laser processing of substrates for light-emitting diodes (LEDs) offers advantages over other processing techniques and is therefore an active research area in both industrial and academic sectors. The processing of sapphire wafers is problematic because sapphire is a hard and brittle material. Semiconductor laser scribing processing suffers certain disadvantages that have yet to be overcome, thereby necessitating further investigation. In this work, a platform for controllable laser thermal cleavage was constructed. A sapphire LED wafer was modeled using the finite element method to simulate the thermal and stress distributions under different conditions. A guide groove cut by laser ablation before the cleavage process was observed to guide the crack extension and avoid deviation. The surface and cross section of sapphire wafers processed using controllable laser thermal cleavage were characterized by scanning electron microscopy and optical microscopy, and their morphology was compared to that of wafers processed using stealth dicing. The differences in luminous efficiency between substrates prepared using these two processing methods are explained.

Heat transfer enhancement in triplex-tube latent thermal energy storage system with selected arrangements of fins

NASA Astrophysics Data System (ADS)

Zhao, Liang; Xing, Yuming; Liu, Xin; Rui, Zhoufeng

2018-01-01

The use of thermal energy storage systems can effectively reduce energy consumption and improve the system performance. One of the promising ways for thermal energy storage system is application of phase change materials (PCMs). In this study, a two-dimensional numerical model is presented to investigate the heat transfer enhancement during the melting/solidification process in a triplex tube heat exchanger (TTHX) by using fluent software. The thermal conduction and natural convection are all taken into account in the simulation of the melting/solidification process. As the volume fraction of fin is kept to be a constant, the influence of proposed fin arrangement on temporal profile of liquid fraction over the melting process is studied and reported. By rotating the unit with different angle, the simulation shows that the melting time varies a little, which means that the installation error can be reduced by the selected fin arrangement. The proposed fin arrangement also can effectively reduce time of the solidification of the PCM by investigating the solidification process. To summarize, this work presents a shape optimization for the improvement of the thermal energy storage system by considering both thermal energy charging and discharging process.

Reconstructing Face Image from the Thermal Infrared Spectrum to the Visible Spectrum †

PubMed Central

Kresnaraman, Brahmastro; Deguchi, Daisuke; Takahashi, Tomokazu; Mekada, Yoshito; Ide, Ichiro; Murase, Hiroshi

2016-01-01

During the night or in poorly lit areas, thermal cameras are a better choice instead of normal cameras for security surveillance because they do not rely on illumination. A thermal camera is able to detect a person within its view, but identification from only thermal information is not an easy task. The purpose of this paper is to reconstruct the face image of a person from the thermal spectrum to the visible spectrum. After the reconstruction, further image processing can be employed, including identification/recognition. Concretely, we propose a two-step thermal-to-visible-spectrum reconstruction method based on Canonical Correlation Analysis (CCA). The reconstruction is done by utilizing the relationship between images in both thermal infrared and visible spectra obtained by CCA. The whole image is processed in the first step while the second step processes patches in an image. Results show that the proposed method gives satisfying results with the two-step approach and outperforms comparative methods in both quality and recognition evaluations. PMID:27110781

Mission Life Thermal Analysis and Environment Correlation for the Lunar Reconnaissance Orbiter

NASA Technical Reports Server (NTRS)

Garrison, Matthew B.; Peabody, Hume

2012-01-01

Standard thermal analysis practices include stacking worst-case conditions including environmental heat loads, thermo-optical properties and orbital beta angles. This results in the design being driven by a few bounding thermal cases, although those cases may only represent a very small portion of the actual mission life. The NASA Goddard Space Flight Center Thermal Branch developed a procedure to predict the flight temperatures over the entire mission life, assuming a known beta angle progression, variation in the thermal environment, and a degradation rate in the coatings. This was applied to the Global Precipitation Measurement core spacecraft. In order to assess the validity of this process, this work applies the similar process to the Lunar Reconnaissance Orbiter. A flight-correlated thermal model was exercised to give predictions of the thermal performance over the mission life. These results were then compared against flight data from the first two years of the spacecraft s use. This is used to validate the process and to suggest possible improvements for future analyses.

Method and apparatus for implementing material thermal property measurement by flash thermal imaging

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

Sun, Jiangang

A method and apparatus are provided for implementing measurement of material thermal properties including measurement of thermal effusivity of a coating and/or film or a bulk material of uniform property. The test apparatus includes an infrared camera, a data acquisition and processing computer coupled to the infrared camera for acquiring and processing thermal image data, a flash lamp providing an input of heat onto the surface of a two-layer sample with an enhanced optical filter covering the flash lamp attenuating an entire infrared wavelength range with a series of thermal images is taken of the surface of the two-layer sample.

Multilevel radiative thermal memory realized by the hysteretic metal-insulator transition of vanadium dioxide

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

Ito, Kota, E-mail: kotaito@mosk.tytlabs.co.jp; Nishikawa, Kazutaka; Iizuka, Hideo

Thermal information processing is attracting much interest as an analog of electronic computing. We experimentally demonstrated a radiative thermal memory utilizing a phase change material. The hysteretic metal-insulator transition of vanadium dioxide (VO{sub 2}) allows us to obtain a multilevel memory. We developed a Preisach model to explain the hysteretic radiative heat transfer between a VO{sub 2} film and a fused quartz substrate. The transient response of our memory predicted by the Preisach model agrees well with the measured response. Our multilevel thermal memory paves the way for thermal information processing as well as contactless thermal management.

Thermal imaging as a biometrics approach to facial signature authentication.

PubMed

Guzman, A M; Goryawala, M; Wang, Jin; Barreto, A; Andrian, J; Rishe, N; Adjouadi, M

2013-01-01

A new thermal imaging framework with unique feature extraction and similarity measurements for face recognition is presented. The research premise is to design specialized algorithms that would extract vasculature information, create a thermal facial signature and identify the individual. The proposed algorithm is fully integrated and consolidates the critical steps of feature extraction through the use of morphological operators, registration using the Linear Image Registration Tool and matching through unique similarity measures designed for this task. The novel approach at developing a thermal signature template using four images taken at various instants of time ensured that unforeseen changes in the vasculature over time did not affect the biometric matching process as the authentication process relied only on consistent thermal features. Thirteen subjects were used for testing the developed technique on an in-house thermal imaging system. The matching using the similarity measures showed an average accuracy of 88.46% for skeletonized signatures and 90.39% for anisotropically diffused signatures. The highly accurate results obtained in the matching process clearly demonstrate the ability of the thermal infrared system to extend in application to other thermal imaging based systems. Empirical results applying this approach to an existing database of thermal images proves this assertion.

Integration of Design, Thermal, Structural, and Optical Analysis, Including Thermal Animation

NASA Technical Reports Server (NTRS)

Amundsen, Ruth M.

1993-01-01

In many industries there has recently been a concerted movement toward 'quality management' and the issue of how to accomplish work more efficiently. Part of this effort is focused on concurrent engineering; the idea of integrating the design and analysis processes so that they are not separate, sequential processes (often involving design rework due to analytical findings) but instead form an integrated system with smooth transfers of information. Presented herein are several specific examples of concurrent engineering methods being carried out at Langley Research Center (LaRC): integration of thermal, structural and optical analyses to predict changes in optical performance based on thermal and structural effects; integration of the CAD design process with thermal and structural analyses; and integration of analysis and presentation by animating the thermal response of a system as an active color map -- a highly effective visual indication of heat flow.

Lecture on Thermal Radiation

NASA Technical Reports Server (NTRS)

Dennis, Brian R.

2006-01-01

This lecture will cover solar thermal radiation, particularly as it relates to the high energy solar processes that are the subject of this summer school. After a general review of thermal radiation from the Sun and a discussion of basic definitions, the various emission and absorption mechanisms will be described including black-body emission, bremsstrahlung, free-bound, and atomic line emissions of all kinds. The bulk of the time will be spent discussing the observational characteristics of thermal flare plasma and what can be learned about the flare energy release process from observations of the thermal radiation at all wavelengths. Information that has been learned about the morphology, temperature distribution, and composition of the flare plasma will be presented. The energetics of the thermal flare plasma will be discussed in relation to the nonthermal energy of the particles accelerated during the flare. This includes the total energy, the radiated and conductive cooling processes, and the total irradiated energy.

Modeling of Thermal Conductivity of CVI-Densified Composites at Fiber and Bundle Level

PubMed Central

Guan, Kang; Wu, Jianqing; Cheng, Laifei

2016-01-01

The evolution of the thermal conductivities of the unidirectional, 2D woven and 3D braided composites during the CVI (chemical vapor infiltration) process have been numerically studied by the finite element method. The results show that the dual-scale pores play an important role in the thermal conduction of the CVI-densified composites. According to our results, two thermal conductivity models applicable for CVI process have been developed. The sensitivity analysis demonstrates the parameter with the most influence on the CVI-densified composites’ thermal conductivity is matrix cracking’s density, followed by volume fraction of the bundle and thermal conductance of the matrix cracks, finally by micro-porosity inside the bundles and macro-porosity between the bundles. The obtained results are well consistent with the reported data, thus our models could be useful for designing the processing and performance of the CVI-densified composites. PMID:28774130

Formation of the image on the receiver of thermal radiation

NASA Astrophysics Data System (ADS)

Akimenko, Tatiana A.

2018-04-01

The formation of the thermal picture of the observed scene with the verification of the quality of the thermal images obtained is one of the important stages of the technological process that determine the quality of the thermal imaging observation system. In this article propose to consider a model for the formation of a thermal picture of a scene, which must take into account: the features of the object of observation as the source of the signal; signal transmission through the physical elements of the thermal imaging system that produce signal processing at the optical, photoelectronic and electronic stages, which determines the final parameters of the signal and its compliance with the requirements for thermal information and measurement systems.

Thermal modeling of nickel-hydrogen battery cells operating under transient orbital conditions

NASA Technical Reports Server (NTRS)

Schrage, Dean S.

1991-01-01

An analytical study of the thermal operating characteristics of nickel-hydrogen battery cells is presented. Combined finite-element and finite-difference techniques are employed to arrive at a computationally efficient composite thermal model representing a series-cell arrangement operating in conjunction with a radiately coupled baseplate and coldplate thermal bus. An aggressive, low-mass design approach indicates that thermal considerations can and should direct the design of the thermal bus arrangement. Special consideration is given to the potential for mixed conductive and convective processes across the hydrogen gap. Results of a compressible flow model are presented and indicate the transfer process is suitably represented by molecular conduction. A high-fidelity thermal model of the cell stack (and related components) indicates the presence of axial and radial temperature gradients. A detailed model of the thermal bus reveals the thermal interaction of individual cells and is imperative for assessing the intercell temperature gradients.

40 CFR 458.20 - Applicability: description of the carbon black thermal process subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability: description of the carbon black thermal process subcategory. 458.20 Section 458.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) CARBON BLACK MANUFACTURING POINT SOURCE CATEGORY Carbon Black Thermal...

40 CFR 458.20 - Applicability: description of the carbon black thermal process subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability: description of the carbon black thermal process subcategory. 458.20 Section 458.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) CARBON BLACK MANUFACTURING POINT SOURCE CATEGORY Carbon Black Thermal...

Thermally stimulated processes in samarium-modified lead titanate ferroelectric ceramics

NASA Astrophysics Data System (ADS)

Peláiz-Barranco, A.; García-Wong, A. C.; González-Abreu, Y.; Gagou, Y.; Saint-Grégoire, P.

2013-08-01

The thermally stimulated processes in a samarium-modified lead titanate ferroelectric system are analyzed from the thermally stimulated depolarization discharge current. The discharge due to the space charge injected during the poling process, the pyroelectric response and a conduction process related to oxygen vacancies are evaluated considering a theoretical decomposition by using a numerical method. The pyroelectric response is separated from other components to evaluate the polarization behavior and some pyroelectric parameters. High remanent polarization, pyroelectric coefficient and merit figure values are obtained at room temperature.

Effect of electron beam radiation processing on mechanical and thermal properties of fully biodegradable crops straw/poly (vinyl alcohol) biocomposites

NASA Astrophysics Data System (ADS)

Guo, Dan

2017-01-01

Fully biodegradable biocomposites based on crops straw and poly(vinyl alcohol) was prepared through thermal processing, and the effect of electron beam radiation processing with N,N-methylene double acrylamide as radiation sensitizer on mechanical and thermal properties of the biocomposites were investigated. The results showed that, when the radiation dose were in the range of 0-50 kGy, the mechanical and thermal properties of the biocomposites could be improved significantly through the electron beam radiation processing, and the interface compatibility was also improved because of the formation of stable cross-linked network structure, when the radiation dose were above the optimal value (50 kGy), the comprehensive properties of the biocomposites were gradually destroyed. EB radiation processing could be used as an effective technology to improve the comprehensive performance of the biocomposites, and as a green and efficient processing technology, radiation processing takes place at room temperature, and no contamination and by-product are possible.

Investigation of Thermophysical Properties of Thermal Degraded Biodiesels

NASA Astrophysics Data System (ADS)

Regatieri, H. R.; Savi, E. L.; Lukasievicz, G. V. B.; Sehn, E.; Herculano, L. S.; Astrath, N. G. C.; Malacarne, L. C.

2018-06-01

Biofuels are an alternative to fossil fuels and can be made from many different raw materials. The use of distinct catalyst and production processes, feedstocks, and types of alcohol results in biofuels with different physical and chemical properties. Even though these diverse options for biodiesel production are considered advantageous, they may pose a setback when quality specifications are considered, since different properties are subject to different reactions during usage, storage and handling. In this work, we present a systematic characterization of biodiesels to investigate how accelerated thermal degradation affects fuel properties. Two different types of biodiesel, commercially obtained from distinct feedstocks, were tested. The thermal degradation process was performed by maintaining the temperature of the sample at 140°C under constant air flux for different times: 0 h, 3 h, 6 h, 9 h, 12 h, 24 h and 36 h. Properties such as density, viscosity, activation energy, volumetric thermal expansion coefficient, gross caloric value, acid value, infrared absorption, and temperature coefficient of the refractive index were used to study the thermal degradation of the biodiesel samples. The results show a significant difference in fuel properties before and after the thermal degradation process suggesting the formation of undesirable compounds. All the properties mentioned above were found to be useful to determine whether a biodiesel sample underwent thermal degradation. Moreover, viscosity and acid value were found to be the most sensitive characteristics to detect the thermal degradation process.

The prediction, observation and study of long-distant undamped thermal waves generated in pulse radiative processes

NASA Astrophysics Data System (ADS)

Vysotskii, V. I.; Kornilova, A. A.; Vasilenko, A. O.; Krit, T. B.; Vysotskyy, M. V.

2017-07-01

The problems of the existence, generation, propagation and registration of long-distant undamped thermal waves formed in pulse radiative processes have been theoretically analyzed and confirmed experimentally. These waves may be used for the analysis of short-time processes of interaction of particles or electromagnetic fields with different targets. Such undamped waves can only exist in environments with a finite (nonzero) time of local thermal relaxation and their frequencies are determined by this time. The results of successful experiments on the generation and registration of undamped thermal waves at a large distance (up to 2 m) are also presented.

Carbon nanotubes for thermal interface materials in microelectronic packaging

NASA Astrophysics Data System (ADS)

Lin, Wei

As the integration scale of transistors/devices in a chip/system keeps increasing, effective cooling has become more and more important in microelectronics. To address the thermal dissipation issue, one important solution is to develop thermal interface materials with higher performance. Carbon nanotubes, given their high intrinsic thermal and mechanical properties, and their high thermal and chemical stabilities, have received extensive attention from both academia and industry as a candidate for high-performance thermal interface materials. The thesis is devoted to addressing some challenges related to the potential application of carbon nanotubes as thermal interface materials in microelectronics. These challenges include: 1) controlled synthesis of vertically aligned carbon nanotubes on various bulk substrates via chemical vapor deposition and the fundamental understanding involved; 2) development of a scalable annealing process to improve the intrinsic properties of synthesized carbon nanotubes; 3) development of a state-of-art assembling process to effectively implement high-quality vertically aligned carbon nanotubes into a flip-chip assembly; 4) a reliable thermal measurement of intrinsic thermal transport property of vertically aligned carbon nanotube films; 5) improvement of interfacial thermal transport between carbon nanotubes and other materials. The major achievements are summarized. 1. Based on the fundamental understanding of catalytic chemical vapor deposition processes and the growth mechanism of carbon nanotube, fast synthesis of high-quality vertically aligned carbon nanotubes on various bulk substrates (e.g., copper, quartz, silicon, aluminum oxide, etc.) has been successfully achieved. The synthesis of vertically aligned carbon nanotubes on the bulk copper substrate by the thermal chemical vapor deposition process has set a world record. In order to functionalize the synthesized carbon nanotubes while maintaining their good vertical alignment, an in situ functionalization process has for the first time been demonstrated. The in situ functionalization renders the vertically aligned carbon nanotubes a proper chemical reactivity for forming chemical bonding with other substrate materials such as gold and silicon. 2. An ultrafast microwave annealing process has been developed to reduce the defect density in vertically aligned carbon nanotubes. Raman and thermogravimetric analyses have shown a distinct defect reduction in the CNTs annealed in microwave for 3 min. Fibers spun from the as-annealed CNTs, in comparison with those from the pristine CNTs, show increases of ˜35% and ˜65%, respectively, in tensile strength (˜0.8 GPa) and modulus (˜90 GPa) during tensile testing; an ˜20% improvement in electrical conductivity (˜80000 S m-1) was also reported. The mechanism of the microwave response of CNTs was discussed. Such a microwave annealing process has been extended to the preparation of reduced graphene oxide. 3. Based on the fundamental understanding of interfacial thermal transport and surface chemistry of metals and carbon nanotubes, two major transfer/assembling processes have been developed: molecular bonding and metal bonding. Effective improvement of the interfacial thermal transport has been achieved by the interfacial bonding. 4. The thermal diffusivity of vertically aligned carbon nanotube (VACNT, multi-walled) films was measured by a laser flash technique, and shown to be ˜30 mm2 s-1 along the tube-alignment direction. The calculated thermal conductivities of the VACNT film and the individual CNTs are ˜27 and ˜540 W m-1 K-1, respectively. The technique was verified to be reliable although a proper sampling procedure is critical. A systematic parametric study of the effects of defects, buckling, tip-to-tip contacts, packing density, and tube-tube interaction on the thermal diffusivity was carried out. Defects and buckling decreased the thermal diffusivity dramatically. An increased packing density was beneficial in increasing the collective thermal conductivity of the VACNT film; however, the increased tube-tube interaction in dense VACNT films decreased the thermal conductivity of the individual CNTs. The tip-to-tip contact resistance was shown to be ˜1x10-7 m2 K W -1. The study will shed light on the potential application of VACNTs as thermal interface materials in microelectronic packaging. 5. A combined process of in situ functionalization and microwave curing has been developed to effective enhance the interface between carbon nanotubes and the epoxy matrix. Effective medium theory has been used to analyze the interfacial thermal resistance between carbon nanotubes and polymer matrix, and that between graphite nanoplatlets and polymer matrix.

Purification process of natural graphite as anode for Li-ion batteries: chemical versus thermal

NASA Astrophysics Data System (ADS)

Zaghib, K.; Song, X.; Guerfi, A.; Rioux, R.; Kinoshita, K.

The intercalation of Li ions in natural graphite that was purified by chemical and thermal processes was investigated. A new chemical process was developed that involved a mixed aqueous solution containing 30% H 2SO 4 and 30% NH xF y heated to 90 °C. The results of this process are compared to those obtained by heating the natural graphite from 1500 to 2400 °C in an inert environment (thermal process). The first-cycle coulombic efficiency of the purified natural graphite obtained by the chemical process is 91 and 84% after the thermal process at 2400 °C. Grinding the natural graphite before or after purification had no significant effect on electrochemical performance at low currents. However, grinding to a very small particle size before purification permitted optimization of the size distribution of the particles, which gives rise to a more homogenous electrode. The impurities in the graphite play a role as microabrasion agents during grinding which enhances its hardness and improves its mechanical properties. Grinding also modifies the particle morphology from a 2- to a 3-D structure (similar in shape to a potato). This potato-shaped natural graphite shows high reversible capacity at high current densities (about 90% at 1 C rate). Our analysis suggests that thermal processing is considerably more expensive than the chemical process to obtain purified natural graphite.

Fate of deoxynivalenol and deoxynivalenol-3-glucoside during cereal-based thermal food processing: a review study.

PubMed

Wu, Qinghua; Kuča, Kamil; Humpf, Hans-Ulrich; Klímová, Blanka; Cramer, Benedikt

2017-02-01

Deoxynivalenol (DON), the most commonly occurring trichothecene in nature, may affect animal and human health through causing diarrhea, vomiting, gastrointestinal inflammation, and immunomodulation. DON-3-glucoside (DON-3G) as a major plant metabolite of the mycotoxin is another "emerging" food safety issue in recent years. Humans may experience potential health risks by consuming DON-contaminated food products. Thus, it is crucial for human and animal health to study also the degradation of DON and DON-3G during thermal food processing. Baking, boiling, steaming, frying, and extrusion cooking are commonly used during thermal food processing and have promising effects on the reduction of mycotoxins in food. For DON, however, the observed effects of these methods, as reported in numerous studies, are ambiguous and do not present a clear picture with regard to reduction or transformation. This review summarized the influence of thermal processing on the stability of DON and the formation of degradation/conversion products. Besides this, also a release of DON and DON-3G from food matrix as well as the release of DON from DON-3G during processing is discussed. In addition, some conflicting findings as reported from the studies on thermal processing as well as cause-effect relationships of the different thermal procedures are explored. Finally, the potential toxic profiles of DON degradation products are discussed as well when data are available.

Densification control and analysis of outer shell of new high-temperature vacuum insulated composite

NASA Astrophysics Data System (ADS)

Wang, Yang; Chen, Zhaofeng; Jiang, Yun; Yu, Shengjie; Xu, Tengzhou; Li, Binbin; Chen, Zhou

2017-11-01

A novel high temperature vacuum insulated composite with low thermal conductivity composed of SiC foam core material and sealing outer shell is discussed, which will have a great potential to be used as thermal protection system material. In this composite, the outer shell is the key to maintain its internal vacuum, which is consisted of 2.5D C/C and SiC coating. So the densification processes of outer shell, including 2.5D braiding process, chemical vapor infiltration (CVI) pyrolytic carbon (PyC) process, polymer infiltration and pyrolysis (PIP) glassy carbon (GC) process and chemical vapor deposition (CVD) SiC process, are focused in this paper. The measuring result of the gas transmission quantity of outer shell is only 0.14 cm3/m2 · d · Pa after 5 times CVD processes, which is two order of magnitude lower than that sample deposited one time. After 10 times thermal shock cycles, the gas transmission quantity increases to 1.2 cm3/m2 · d · Pa. The effective thermal conductivity of high temperature vacuum insulated composite ranged from 0.19 W m-1 K-1 to 0.747 W m-1 K-1 within the temperature from 20 °C to 900 °C. Even after 10 thermal shock cycles, the variation of the effective thermal conductivity is still consistent with that without treatments.

Effect of heating rate on thermal cracking characteristics and kinetics of Xinjiang oil sand bitumen by TG-FTIR

NASA Astrophysics Data System (ADS)

Hao, Junhui; Zhang, Jinhong; Qiao, Yingyun; Tian, Yuanyu

2017-08-01

This work was aimed to investigate effects of heating rate on thermal cracking behaviors, distribution of gaseous products and activation energy of the thermal cracking process of Xinjiang oil sand bitumen (OSB). The thermal cracking experiments of Xinjiang OSB were performed by using thermogravimetric analyzer (TGA) at various heating rates of 10, 20, 50, 80 and 120 K/min. The evolving characteristic of gaseous products produced from the thermal cracking process was evaluated by the Fourier transform infrared spectrometry (FTIR) connected with TG. The kinetic parameters of the thermal cracking process of Xinjiang OSB at each of heating rate were determined by the Coats-Redfern model. The result show that the temperature intervals of DE volatilization stage and main reaction stage, the ((dw/dt) max and Tmax in thermal cracking process of Xinjiang OSB all increased with the increasing heating rate. While the heating rate has not obvious effect on the coke yield of Xinjiang OSB. Furthermore, the maximum absorbance of gaseous products and corresponding temperature became larger as the heating rate increases. The activation energy of this two stage both presented increasing trend with the rising heating rate, while the increasing content of that of DE volatilization stage was weaker compared to that of main reaction stage.

Radiative bistability and thermal memory.

PubMed

Kubytskyi, Viacheslav; Biehs, Svend-Age; Ben-Abdallah, Philippe

2014-08-15

We predict the existence of a thermal bistability in many-body systems out of thermal equilibrium which exchange heat by thermal radiation using insulator-metal transition materials. We propose a writing-reading procedure and demonstrate the possibility to exploit the thermal bistability to make a volatile thermal memory. We show that this thermal memory can be used to store heat and thermal information (via an encoding temperature) for arbitrary long times. The radiative thermal bistability could find broad applications in the domains of thermal management, information processing, and energy storage.

Thermal properties of simulated Hanford waste glasses

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

Rodriguez, Carmen P.; Chun, Jaehun; Crum, Jarrod V.

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) will vitrify the mixed hazardous wastes generated from 45 years of plutonium production. The molten glasses will be poured into stainless steel containers or canisters and subsequently quenched for storage and disposal. Such highly energy-consuming processes require precise thermal properties of materials for appropriate facility design and operations. Key thermal properties (heat capacity, thermal diffusivity, and thermal conductivity) of representative high-level and low-activity waste glasses were studied as functions of temperature in the range of 200 to 800°C (relevant to the cooling process), implementing simultaneous differential scanning calorimetry-thermal gravimetry (DSC-TGA), Xe-flashmore » diffusivity, pycnometry, and dilatometry. The study showed that simultaneous DSC-TGA would be a reliable method to obtain heat capacity of various glasses at the temperature of interest. Accurate thermal properties from this study were shown to provide a more realistic guideline for capacity and time constraint of heat removal process, in comparison to the design basis conservative engineering estimates. The estimates, though useful for design in the absence measured physical properties, can now be supplanted and the measured thermal properties can be used in design verification activities.« less

Investigation of the charge boost technology for the efficiency increase of closed sorption thermal energy storage systems

NASA Astrophysics Data System (ADS)

Rohringer, C.; Engel, G.; Köll, R.; Wagner, W.; van Helden, W.

2017-10-01

The inclusion of solar thermal energy into energy systems requires storage possibilities to overcome the gap between supply and demand. Storage of thermal energy with closed sorption thermal energy systems has the advantage of low thermal losses and high energy density. However, the efficiency of these systems needs yet to be increased to become competitive on the market. In this paper, the so-called “charge boost technology” is developed and tested via experiments as a new concept for the efficiency increase of compact thermal energy storages. The main benefit of the charge boost technology is that it can reach a defined state of charge for sorption thermal energy storages at lower temperature levels than classic pure desorption processes. Experiments are conducted to provide a proof of principle for this concept. The results show that the charge boost technology does function as predicted and is a viable option for further improvement of sorption thermal energy storages. Subsequently, a new process application is developed by the author with strong focus on the utilization of the advantages of the charge boost technology over conventional desorption processes. After completion of the conceptual design, the theoretical calculations are validated via experiments.

Factors Influencing Residual Stresses in Yttria Stabilized Zirconia Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

McGrann, Roy T. R.; Rybicki, Edmund F.; Shadley, John R.; Brindley, William J.

1997-01-01

To improve gas turbine and diesel engine performance using thermal barrier coatings (TBC's) requires an understanding of the factors that influence the in-service behavior of thermal barrier coatings. One of the many factors related to coating performance is the state of stress in the coating. The total stress state is composed of the stresses due to the in-service loading history and the residual stresses. Residual stresses have been shown to affect TBC life, the bond strength of thermal spray coatings, and the fatigue life of tungsten carbide coatings. Residual stresses are first introduced in TBC's by the spraying process due to elevated temperatures during processing and the difference in coefficients of thermal expansion of the top coat, bond coat, and substrate. Later, the residual stresses can be changed by the in-service temperature history due to a number of time and temperature dependent mechanisms, such as oxidation, creep, and sintering. Silica content has also been shown to affect sintering and the cyclic life of thermal barrier coatings. Thus, it is important to understand how the spraying process, the in-service thermal cycles, and the silica content can create and alter residual stresses in thermal barrier coatings.

Probing the heat sources during thermal runaway process by thermal analysis of different battery chemistries

NASA Astrophysics Data System (ADS)

Zheng, Siqi; Wang, Li; Feng, Xuning; He, Xiangming

2018-02-01

Safety issue is very important for the lithium ion battery used in electric vehicle or other applications. This paper probes the heat sources in the thermal runaway processes of lithium ion batteries composed of different chemistries using accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC). The adiabatic thermal runaway features for the 4 types of commercial lithium ion batteries are tested using ARC, whereas the reaction characteristics of the component materials, including the cathode, the anode and the separator, inside the 4 types of batteries are measured using DSC. The peaks and valleys of the critical component reactions measured by DSC can match the fluctuations in the temperature rise rate measured by ARC, therefore the relevance between the DSC curves and the ARC curves is utilized to probe the heat source in the thermal runaway process and reveal the thermal runaway mechanisms. The results and analysis indicate that internal short circuit is not the only way to thermal runaway, but can lead to extra electrical heat, which is comparable with the heat released by chemical reactions. The analytical approach of the thermal runaway mechanisms in this paper can guide the safety design of commercial lithium ion batteries.

Local probing of thermal energy transfer and conversion processes in VO2 nanostructures

NASA Astrophysics Data System (ADS)

Menges, Fabian

Nanostructures of strongly correlated materials, such as metal-insulator transition (MIT) oxides, enable unusual coupling of charge and heat transport. Hence, they provide an interesting pathway to the development of non-linear thermal devices for active heat flux control. Here, we will report the characterization of local thermal non-equilibrium processes in vanadium dioxide (VO2) thin films and single-crystalline nanobeams. Using a scanning thermal microscope and calorimetric MEMS platforms, we studied the MIT triggered by electrical currents, electrical fields, near-field thermal radiation and thermal conduction. Based on out recently introduced scanning probe thermometry method, which enables direct imaging of local Joule and Peltier effects, we quantified self-heating processes in VO2 memristors using the tip of a resistively heated scanning probe both as local sensor and nanoscopic heat source. Finally, we will report on recent approaches to build radiative thermal switches and oscillators using VO2 nanostructures. We quantified variations of near-field radiative thermal transport between silicon dioxide and VO2 down to nanoscopic gap sizes, and will discuss its implications for the development of phonon polariton based radiative thermal devices. Funding of the Swiss Federal Office of Energy under Grant Agreement No. SI/501093-01 is gratefully acknowledged.

9 CFR 381.302 - Thermal processing.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Thermal processing. 381.302 Section 381.302 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... and critical factors. (2) Letters or other written communications from a processing authority...

Holographic thermalization and generalized Vaidya-AdS solutions in massive gravity

NASA Astrophysics Data System (ADS)

Hu, Ya-Peng; Zeng, Xiao-Xiong; Zhang, Hai-Qing

2017-02-01

We investigate the effect of massive graviton on the holographic thermalization process. Before doing this, we first find out the generalized Vaidya-AdS solutions in the de Rham-Gabadadze-Tolley (dRGT) massive gravity by directly solving the gravitational equations. Then, we study the thermodynamics of these Vaidya-AdS solutions by using the Misner-Sharp energy and unified first law, which also shows that the massive gravity is in a thermodynamic equilibrium state. Moreover, we adopt the two-point correlation function at equal time to explore the thermalization process in the dual field theory, and to see how the graviton mass parameter affects this process from the viewpoint of AdS/CFT correspondence. Our results show that the graviton mass parameter will increase the holographic thermalization process.

Powder Processing of High Temperature Cermets and Carbides at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Salvail, Pat; Panda, Binayak; Hickman, Robert R.

2007-01-01

The Materials and Processing Laboratory at NASA Marshall Space Flight Center is developing Powder Metallurgy (PM) processing techniques for high temperature cermet and carbide material consolidation. These new group of materials would be utilized in the nuclear core for Nuclear Thermal Rockets (NTR). Cermet materials offer several advantages for NTR such as retention of fission products and fuels, better thermal shock resistance, hydrogen compatibility, high thermal conductivity, and high strength. Carbide materials offer the highest operating temperatures but are sensitive to thermal stresses and are difficult to process. To support the effort, a new facility has been setup to process refractory metal, ceramic, carbides and depleted uranium-based powders. The facility inciudes inert atmosphere glove boxes for the handling of reactive powders, a high temperature furnace, and powder processing equipment used for blending, milling, and sieving. The effort is focused on basic research to identify the most promising compositions and processing techniques. Several PM processing methods including Cold and Hot Isostatic Pressing are being evaluated to fabricate samples for characterization and hot hydrogen testing.

Method and apparatus for thermal processing of semiconductor substrates

DOEpatents

Griffiths, Stewart K.; Nilson, Robert H.; Mattson, Brad S.; Savas, Stephen E.

2002-01-01

An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls. Further, peak power requirements are very small compared to lamp-heated RTPs because the cavity temperature is not cycled and the thermal mass of the cavity is relatively large. Increased speeds of insertion and/or removal may also be used with non-isothermal furnaces.

Method and apparatus for thermal processing of semiconductor substrates

DOEpatents

Griffiths, Stewart K.; Nilson, Robert H.; Mattson, Brad S.; Savas, Stephen E.

2000-01-01

An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls. Further, peak power requirements are very small compared to lamp-heated RTPs because the cavity temperature is not cycled and the thermal mass of the cavity is relatively large. Increased speeds of insertion and/or removal may also be used with non-isothermal furnaces.

Influence of Sulfur Fertilization on the Antioxidant Activities of Onion Juices Prepared by Thermal Treatment

PubMed Central

Koh, Eunmi; Surh, Jeonghee

2016-01-01

Two onions (Sulfur-1 and Sulfur-4) cultivated with different sulfur applications were thermally processed to elucidate the effects of heat treatment on browning index and antioxidant activity. Sulfur-4 onion had higher sulfur content compared with the Sulfur-1 onion. After thermal processing, browning intensity was different between the two onions juices, with lower values observed for Sulfur-4 onion juice. This suggests that sulfur inhibits the Maillard browning reaction. The total reducing capacity of the juices increased at higher thermal processing temperatures; however, it was also lower in the Sulfur-4 onion juice. This suggests that the heat treatment of onions enhanced their antioxidant activity, but the effect was offset in the Sulfur-4 onion juice presumably due to higher sulfur content. This study indicates that sulfur, a core element for the functionality of onions, can decrease the antioxidant activity of thermally processed onions because of its potential as a Maillard reaction inhibitor. PMID:27390734

Study of multilayer thermal insulation by inverse problems method

NASA Astrophysics Data System (ADS)

Alifanov, O. M.; Nenarokomov, A. V.; Gonzalez, V. M.

2009-11-01

The purpose of this paper is to introduce a new method in the research of radiative and thermal properties of materials with further applications in the design of thermal control systems (TCS) of spacecrafts. In this paper the radiative and thermal properties (emissivity and thermal conductance) of a multilayered thermal-insulating blanket (MLI), which is a screen-vacuum thermal insulation as a part of the TCS for perspective spacecrafts, are estimated. Properties of the materials under study are determined in the result of temperature and heat flux measurement data processing based on the solution of the inverse heat transfer problem (IHTP) technique. Given are physical and mathematical models of heat transfer processes in a specimen of the multilayered thermal-insulating blanket located in the experimental facility. A mathematical formulation of the inverse heat conduction problem is presented as well. The practical approves were made for specimen of the real MLI.

Low-cycle thermal fatigue

NASA Technical Reports Server (NTRS)

Halford, G. R.

1986-01-01

A state-of-the-art review is presented of the field of thermal fatigue. Following a brief historical review, the concept is developed that thermal fatigue can be viewed as processes of unbalanced deformation and cracking. The unbalances refer to dissimilar mechanisms occurring in opposing halves of thermal fatigue loading and unloading cycles. Extensive data summaries are presented and results are interpreted in terms of the unbalanced processes involved. Both crack initiation and crack propagation results are summarized. Testing techniques are reviewed, and considerable discussion is given to a technique for thermal fatigue simulation, known as the bithermal fatigue test. Attention is given to the use of isothermal life prediction methods for the prediction of thermal fatigue lives. Shortcomings of isothermally-based life prediction methods are pointed out. Several examples of analyses and thermal fatigue life predictions of high technology structural components are presented. Finally, numerous dos and don'ts relative to design against thermal fatigue are presented.

Effect of Material Inhomogeneity on Thermal Performance of a Rheocast Aluminum Heatsink for Electronics Cooling

NASA Astrophysics Data System (ADS)

Payandeh, M.; Belov, I.; Jarfors, A. E. W.; Wessén, M.

2016-06-01

The relation between microstructural inhomogeneity and thermal conductivity of a rheocast component manufactured from two different aluminum alloys was investigated. The formation of two different primary α-Al particles was observed and related to multistage solidification process during slurry preparation and die cavity filling process. The microstructural inhomogeneity of the component was quantified as the fraction of α 1-Al particles in the primary Al phase. A high fraction of coarse solute-lean α 1-Al particles in the primary Al phase caused a higher thermal conductivity of the component in the near-to-gate region. A variation in thermal conductivity through the rheocast component of 10% was discovered. The effect of an inhomogeneous temperature-dependent thermal conductivity on the thermal performance of a large rheocast heatsink for electronics cooling in an operation environment was studied by means of simulation. Design guidelines were developed to account for the thermal performance of heatsinks with inhomogeneous thermal conductivity, as caused by the rheocasting process. Under the modeling assumptions, the simulation results showed over 2.5% improvement in heatsink thermal resistance when the higher conductivity near-to-gate region was located at the top of the heatsink. Assuming homogeneous thermo-physical properties in a rheocast heatsink may lead to greater than 3.5% error in the estimation of maximum thermal resistance of the heatsink. The variation in thermal conductivity within a large rheocast heatsink was found to be important for obtaining of a robust component design.

Nonthermal processing of orange juice using a pilot-plant scale supercritical carbon dioxide system with a gas-liquid metal contactor

USDA-ARS?s Scientific Manuscript database

To evaluate the effect of pilot-plant scale, non-thermal supercritical carbon dioxide (SCCO2) processing on the safety and the quality of orange juice (OJ), SCCO2 processed juice was compared with untreated fresh juice and equivalently thermal processed juice in terms of lethality. SCCO2 processing ...

Inverse Thermal Analysis of Titanium GTA Welds Using Multiple Constraints

NASA Astrophysics Data System (ADS)

Lambrakos, S. G.; Shabaev, A.; Huang, L.

2015-06-01

Inverse thermal analysis of titanium gas-tungsten-arc welds using multiple constraint conditions is presented. This analysis employs a methodology that is in terms of numerical-analytical basis functions for inverse thermal analysis of steady-state energy deposition in plate structures. The results of this type of analysis provide parametric representations of weld temperature histories that can be adopted as input data to various types of computational procedures, such as those for prediction of solid-state phase transformations. In addition, these temperature histories can be used to construct parametric function representations for inverse thermal analysis of welds corresponding to other process parameters or welding processes whose process conditions are within similar regimes. The present study applies an inverse thermal analysis procedure that provides for the inclusion of constraint conditions associated with both solidification and phase transformation boundaries.

Composition and Manufacturing Effects on Electrical Conductivity of Li/FeS 2 Thermal Battery Cathodes

DOE PAGES

Reinholz, Emilee L.; Roberts, Scott A.; Apblett, Christopher A.; ...

2016-06-11

The electrical conductivity is key to the performance of thermal battery cathodes. In this work we present the effects of manufacturing and processing conditions on the electrical conductivity of Li/FeS2 thermal battery cathodes. Finite element simulations were used to compute the conductivity of three-dimensional microcomputed tomography cathode microstructures and compare results to experimental impedance spectroscopy measurements. A regression analysis reveals a predictive relationship between composition, processing conditions, and electrical conductivity; a trend which is largely erased after thermally-induced deformation. Moreover, the trend applies to both experimental and simulation results, although is not as apparent in simulations. This research is amore » step toward a more fundamental understanding of the effects of processing and composition on thermal battery component microstructure, properties, and performance.« less

40 CFR 74.48 - Transfer of allowances from the replacement of thermal energy-process sources. [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Transfer of allowances from the replacement of thermal energy-process sources. [Reserved] 74.48 Section 74.48 Protection of Environment... energy—process sources. [Reserved] ...

Chemical Changes in Carbohydrates Produced by Thermal Processing.

ERIC Educational Resources Information Center

Hoseney, R. Carl

1984-01-01

Discusses chemical changes that occur in the carbohydrates found in food products when these products are subjected to thermal processing. Topics considered include browning reactions, starch found in food systems, hydrolysis of carbohydrates, extrusion cooking, processing of cookies and candies, and alterations in gums. (JN)

DEMONSTRATION BULLETIN: IN-SITU THERMAL OXIDATION PROCESS - HRUBETZ ENVIRONMENTAL SERVICES

EPA Science Inventory

The HRUBOUT process is a thermal, treatment process designed to remove VOCs and semi-VOCs from contaminated soils. Heated air is injected into the soil below the contamination zone, evaporating soil moisture and removing volatile and semivolatile hydrocarbons. As the water evapor...

Thermal Effects on Microstructural Heterogeneity of Inconel 718 Materials Fabricated by Electron Beam Melting

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

Sames, William J.; Unocic, Kinga A.; Dehoff, Ryan R.

2014-07-28

Additive manufacturing (AM) technologies, also known as 3D printing, have demonstrated the potential to fabricate complex geometrical components, but the resulting microstructures and mechanical properties of these materials are not well understood due to unique and complex thermal cycles observed during processing. The electron beam melting (EBM) process is unique because the powder bed temperature can be elevated and maintained at temperatures over 1000 °C for the duration of the process. This results in three specific stages of microstructural phase evolution: (a) rapid cool down from the melting temperature to the process temperature, (b) extended hold at the process temperature,more » and (c) slow cool down to the room temperature. In this work, the mechanisms for reported microstructural differences in EBM are rationalized for Inconel 718 based on measured thermal cycles, preliminary thermal modeling, and computational thermodynamics models. The relationship between processing parameters, solidification microstructure, interdendritic segregation, and phase precipitation (δ, γ´, and γ´´) are discussed.« less

TEM study of the FSW nugget in AA2195-T81

NASA Technical Reports Server (NTRS)

Schneider, J. A.; Nunes, A. C., Jr.; Chen, P. S.; Steele, G.

2004-01-01

During fiiction stir welding (FSW) the material being joined is subjected to a thermal- mechanical process in which the temperature, strain and strain rates are not completely understood. To produce a defect fiee weld, process parameters for the weld and tool pin design must be chosen carefully. The ability to select the weld parameters based on the thermal processing requirements of the material, would allow optimization of mechanical properties in the weld region. In this study, an attempt is made to correlate the microstructure with the variation in thermal history the material experiences during the FSW process.

Thermal Regulation of Heat Transfer Processes

DTIC Science & Technology

2014-10-02

determine the contrasts of thermophysical properties of composites and thin films , and various approaches to regulate heat transport processes. In the...nanofluids, 2) thermal regulation of optical properties in thin film , and 3) thermal regulation of phase transition for efficient steam generation...stress generated during the crystals growth forces CNTs to contact with each other and form a conductive percolation network. Hence the composite

Zinc thermal spray coatings for reinforced concrete: An AWS process standard

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

Sulit, R.A.

Zinc and aluminum thermal spray coatings (TSC) have been used for lining concrete weir in Great Britain since the 1950`s to maintain the dimensions of the weir for flow control concomitant with reduced wear and erosion of the concrete surfaces. This paper reports the development and the content of the ANSI/AWS C2.20-XX standard for the application of An TSC on concrete using flame and arc spray processes. This standard is formatted as an industrial process instruction: job description; safety; feedstock materials; equipment; a step-by-step method for surface preparation, thermal spraying; quality control; repair and maintenance of surface preparation, thermal spraying;more » quality control; repair and maintenance of Zn TSC on concrete; and a Job Control Record. Job planning and training and certification requirements are presented for An TSC inspectors and thermal spray operators. Four annexes are included in the standard: (a) historical summary of Zn TSC on concrete (b) sample job control record; (c) thermal spray operator qualification; and (d) portable adhesion testing for An TSC on concrete. This standard is based on the current literature and industrial equipment, process, and practices.« less

Thermal degradation of the solvent employed in the next-generation caustic-side solvent extraction process and its effect on the extraction, scrubbing, and stripping of cesium

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

Roach, Benjamin D.; Williams, Neil J.; Moyer, Bruce A.

As part of the ongoing development of the Next-Generation Caustic-Side Solvent Extraction (NGS) process, the thermal stability of the process solvent was investigated and shown to be adequate for industrial application. The solvent was thermally treated at 35 C over a period of 13 months whilst in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS 15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). The effect of thermal treatment was evaluated by assessing batch extract/scrub/strip performance as a function of time, by monitoringmore » the sodium extraction capacity of the solvent, and by analysis of the solvent using electrospray mass spectrometry. Current studies indicate that the NGS solvent should be thermally robust for a period of XXX months at the Modular Caustic-Side Solvent Extraction Unit (MCU) pilot plant located at Savannah River Site. Furthermore, the guanidine suppressor appears to be the solvent component most significantly impacted by thermal treatment of the solvent, showing significant degradation over time.« less

Thermal degradation of the solvent employed in the next-generation caustic-side solvent extraction process and its effect on the extraction, scrubbing, and stripping of cesium

DOE PAGES

Roach, Benjamin D.; Williams, Neil J.; Moyer, Bruce A.

2015-09-02

As part of the ongoing development of the Next-Generation Caustic-Side Solvent Extraction (NGS) process, the thermal stability of the process solvent was investigated and shown to be adequate for industrial application. The solvent was thermally treated at 35 C over a period of 13 months whilst in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS 15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). The effect of thermal treatment was evaluated by assessing batch extract/scrub/strip performance as a function of time, by monitoringmore » the sodium extraction capacity of the solvent, and by analysis of the solvent using electrospray mass spectrometry. Current studies indicate that the NGS solvent should be thermally robust for a period of XXX months at the Modular Caustic-Side Solvent Extraction Unit (MCU) pilot plant located at Savannah River Site. Furthermore, the guanidine suppressor appears to be the solvent component most significantly impacted by thermal treatment of the solvent, showing significant degradation over time.« less

Strawberry puree processed by thermal, high pressure, or power ultrasound: Process energy requirements and quality modeling during storage.

PubMed

Sulaiman, Alifdalino; Farid, Mohammed; Silva, Filipa Vm

2017-06-01

Strawberry puree was processed for 15 min using thermal (65 ℃), high-pressure processing (600 MPa, 48 ℃), and ultrasound (24 kHz, 1.3 W/g, 33 ℃). These conditions were selected based on similar polyphenoloxidase inactivation (11%-18%). The specific energies required for the above-mentioned thermal, high-pressure processing, and power ultrasound processes were 240, 291, and 1233 kJ/kg, respectively. Then, the processed strawberry was stored at 3 ℃ and room temperature for 30 days. The constant pH (3.38±0.03) and soluble solids content (9.03 ± 0.25°Brix) during storage indicated a microbiological stability. Polyphenoloxidase did not reactivate during storage. The high-pressure processing and ultrasound treatments retained the antioxidant activity (70%-74%) better than the thermal process (60%), and high-pressure processing was the best treatment after 30 days of ambient storage to preserve antioxidant activity. Puree treated with ultrasound presented more color retention after processing and after ambient storage than the other preservation methods. For the three treatments, the changes of antioxidant activity and total color difference during storage were described by the fractional conversion model with rate constants k ranging between 0.03-0.09 and 0.06-0.22 day  - 1 , respectively. In resume, high-pressure processing and thermal processes required much less energy than ultrasound for the same polyphenoloxidase inactivation in strawberry. While high-pressure processing retained better the antioxidant activity of the strawberry puree during storage, the ultrasound treatment was better in terms of color retention.

Viscous and thermal modelling of thermoplastic composites forming process

NASA Astrophysics Data System (ADS)

Guzman, Eduardo; Liang, Biao; Hamila, Nahiene; Boisse, Philippe

2016-10-01

Thermoforming thermoplastic prepregs is a fast manufacturing process. It is suitable for automotive composite parts manufacturing. The simulation of thermoplastic prepreg forming is achieved by alternate thermal and mechanical analyses. The thermal properties are obtained from a mesoscopic analysis and a homogenization procedure. The forming simulation is based on a viscous-hyperelastic approach. The thermal simulations define the coefficients of the mechanical model that depend on the temperature. The forming simulations modify the boundary conditions and the internal geometry of the thermal analyses. The comparison of the simulation with an experimental thermoforming of a part representative of automotive applications shows the efficiency of the approach.

Building Thermal Models

NASA Technical Reports Server (NTRS)

Peabody, Hume L.

2017-01-01

This presentation is meant to be an overview of the model building process It is based on typical techniques (Monte Carlo Ray Tracing for radiation exchange, Lumped Parameter, Finite Difference for thermal solution) used by the aerospace industry This is not intended to be a "How to Use ThermalDesktop" course. It is intended to be a "How to Build Thermal Models" course and the techniques will be demonstrated using the capabilities of ThermalDesktop (TD). Other codes may or may not have similar capabilities. The General Model Building Process can be broken into four top level steps: 1. Build Model; 2. Check Model; 3. Execute Model; 4. Verify Results.

Advances in Thermal Spray Coatings for Gas Turbines and Energy Generation: A Review

NASA Astrophysics Data System (ADS)

Hardwicke, Canan U.; Lau, Yuk-Chiu

2013-06-01

Functional coatings are widely used in energy generation equipment in industries such as renewables, oil and gas, propulsion engines, and gas turbines. Intelligent thermal spray processing is vital in many of these areas for efficient manufacturing. Advanced thermal spray coating applications include thermal management, wear, oxidation, corrosion resistance, sealing systems, vibration and sound absorbance, and component repair. This paper reviews the current status of materials, equipment, processing, and properties' aspects for key coatings in the energy industry, especially the developments in large-scale gas turbines. In addition to the most recent industrial advances in thermal spray technologies, future technical needs are also highlighted.

Thermal Fatigue and Fracture Behavior of Ceramic Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Choi, Sung R.; Miller, Robert A.

2001-01-01

Thermal fatigue and fracture behavior of plasma-sprayed ceramic thermal barrier coatings has been investigated under high heat flux and thermal cyclic conditions. The coating crack propagation is studied under laser heat flux cyclic thermal loading, and is correlated with dynamic fatigue and strength test results. The coating stress response and inelasticity, fatigue and creep interactions, and interface damage mechanisms during dynamic thermal fatigue processes are emphasized.

Welding Development: Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Ding, Jeff

2007-01-01

This paper presents the basic understanding of the friction stir welding process. It covers process description, pin tool operation and materials, metal flow theory, mechanical properties, and materials welded using the process. It also discusses the thermal stir welding process and the differences between thermal stir and friction stir welding. MSFC weld tools used for development are also presented.

Laser Processing of Multilayered Thermal Spray Coatings: Optimal Processing Parameters

NASA Astrophysics Data System (ADS)

Tewolde, Mahder; Zhang, Tao; Lee, Hwasoo; Sampath, Sanjay; Hwang, David; Longtin, Jon

2017-12-01

Laser processing offers an innovative approach for the fabrication and transformation of a wide range of materials. As a rapid, non-contact, and precision material removal technology, lasers are natural tools to process thermal spray coatings. Recently, a thermoelectric generator (TEG) was fabricated using thermal spray and laser processing. The TEG device represents a multilayer, multimaterial functional thermal spray structure, with laser processing serving an essential role in its fabrication. Several unique challenges are presented when processing such multilayer coatings, and the focus of this work is on the selection of laser processing parameters for optimal feature quality and device performance. A parametric study is carried out using three short-pulse lasers, where laser power, repetition rate and processing speed are varied to determine the laser parameters that result in high-quality features. The resulting laser patterns are characterized using optical and scanning electron microscopy, energy-dispersive x-ray spectroscopy, and electrical isolation tests between patterned regions. The underlying laser interaction and material removal mechanisms that affect the feature quality are discussed. Feature quality was found to improve both by using a multiscanning approach and an optional assist gas of air or nitrogen. Electrically isolated regions were also patterned in a cylindrical test specimen.

Effect of thermal processing practices on the properties of superplastic Al-Li alloys

NASA Technical Reports Server (NTRS)

Hales, Stephen J.; Lippard, Henry E.

1993-01-01

The effect of thermal processing on the mechanical properties of superplastically formed structural components fabricated from three aluminum-lithium alloys was evaluated. The starting materials consisted of 8090, 2090, and X2095 (Weldalite(TM) 049), in the form of commercial-grade superplastic sheet. The experimental test matrix was designed to assess the impact on mechanical properties of eliminating solution heat treatment and/or cold water quenching from post-forming thermal processing. The extensive hardness and tensile property data compiled are presented as a function of aging temperature, superplastic strain and temper/quench rate for each alloy. The tensile properties of the materials following superplastic forming in two T5-type tempers are compared with the baseline T6 temper. The implications for simplifying thermal processing without degradation in properties are discussed on the basis of the results.

Thermal and Surface Evaluation on The Process of Forming a Cu2O/CuO Semiconductor Photocatalyst on a Thin Copper Plate

NASA Astrophysics Data System (ADS)

Zainul, R.; Oktavia, B.; Dewata, I.; Efendi, J.

2018-04-01

This research aims to investigate the process of forming a multi-scale copper oxide semiconductor (CuO/Cu2O) through a process of calcining a copper plate. The changes that occur during the formation of the oxide are thermally and surface evaluated. Evaluation using Differential Thermal Analysis (DTA) obtained by surface change of copper plate happened at temperature 380°C. Calcination of oxide formation was carried out at temperature 380°C for 1 hour. Surface evaluation process by using Scanning Electron Microscope (SEM) surface and cross-section, to determine diffusion of oxide formation on copper plate. The material composition is monitored by XRF and XRD to explain the process of structural and physical changes of the copper oxide plate formed during the heating process. The thickness of Cu plates used is 200-250 μm. SEM analysis results, the oxygen atom interruption region is in the range of 20-30 μm, and diffuses deeper during thermal oxidation process. The maximum diffusion depth of oxygen atoms reaches 129 μm.

Fossilization processes in siliceous thermal springs: trends in preservation along thermal gradients

NASA Technical Reports Server (NTRS)

Cady, S. L.; Farmer, J. D.

1996-01-01

To enhance our ability to extract palaeobiological and palaeoenvironmental information from ancient thermal spring deposits, we have studied the processes responsible for the development and preservation of stromatolites in modern subaerial thermal spring systems in Yellowstone National Park (USA). We investigated specimens collected from silica-depositing thermal springs along the thermal gradient using petrographic techniques and scanning electron microscopy. Although it is known that thermophilic cyanobacteria control the morphogenesis of thermal spring stromatolites below 73 degrees C, we have found that biofilms which contain filamentous thermophiles contribute to the microstructural development of subaerial geyserites that occur along the inner rims of thermal spring pools and geyser effluents. Biofilms intermittently colonize the surfaces of subaerial geyserites and provide a favoured substrate for opaline silica precipitation. We have also found that the preservation of biotically produced microfabrics of thermal spring sinters reflects dynamic balances between rates of population growth, decomposition of organic matter, silica deposition and early diagenesis. Major trends in preservation of thermophilic organisms along the thermal gradient are defined by differences in the mode of fossilization, including replacement, encrustation and permineralization.

9 CFR 318.303 - Critical factors and the application of the process schedule.

Code of Federal Regulations, 2010 CFR

2010-01-01

... container; (3) Container orientation during thermal processing; (4) Product formulation; (5) Particle size; (6) Maximum thickness for flexible, and to some extent semirigid containers during thermal processing; (7) Maximum pH; (8) Percent salt; (9) Ingoing (or formulated) nitrite level (ppm); (10) Maximum water...

21 CFR 113.87 - Operations in the thermal processing room.

Code of Federal Regulations, 2013 CFR

2013-04-01

... (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY SEALED... should be made. (c) The initial temperature of the contents of the containers to be processed shall be accurately determined and recorded with sufficient frequency to ensure that the temperature of the product is...

21 CFR 113.87 - Operations in the thermal processing room.

Code of Federal Regulations, 2014 CFR

2014-04-01

... (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY SEALED... should be made. (c) The initial temperature of the contents of the containers to be processed shall be accurately determined and recorded with sufficient frequency to ensure that the temperature of the product is...

Impact of pulse thermal processing on the properties of inkjet printed metal and flexible sensors

DOE PAGES

Joshi, Pooran C.; Kuruganti, Teja; Killough, Stephen M.

2015-03-11

In this paper, we report on the low temperature processing of environmental sensors employing pulse thermal processing (PTP) technique to define a path toward flexible sensor technology on plastic, paper, and fabric substrates. Inkjet printing and pulse thermal processing technique were used to realize mask-less, additive integration of low-cost sensors on polymeric substrates with specific focus on temperature, humidity, and strain sensors. The printed metal line performance was evaluated in terms of the electrical conductivity characteristics as a function of post-deposition thermal processing conditions. The PTP processed Ag metal lines exhibited high conductivity with metal sheet resistance values below 100more » mΩ/{whitesquare} using a pulse width as short as 250 μs. The flexible temperature and relative humidity sensors were defined on flexible polyimide substrates by direct printing of Ag metal structures. The printed resistive temperature sensor and capacitive humidity sensor were characterized for their sensitivity with focus on future smart-building applications. Strain gauges were printed on polyimide substrate to determine the mechanical properties of the silver nanoparticle films. Finally, the observed electrical properties of the printed metal lines and the sensitivity of the flexible sensors show promise for the realization of a high performance print-on-demand technology exploiting low thermal-budget PTP technique.« less

Practical Aspects of Suspension Plasma Spray for Thermal Barrier Coatings on Potential Gas Turbine Components

NASA Astrophysics Data System (ADS)

Ma, X.; Ruggiero, P.

2018-04-01

Suspension plasma spray (SPS) process has attracted extensive efforts and interests to produce fine-structured and functional coatings. In particular, thermal barrier coatings (TBCs) applied by SPS process gain increasing interest due to its potential for superior thermal protection of gas turbine hot sections as compared to conventional TBCs. Unique columnar architectures and nano- and submicrometric grains in the SPS-TBC demonstrated some advantages of thermal shock durability, low thermal conductivity, erosion resistance and strain-tolerant microstructure. This work aimed to look into some practical aspects of SPS processing for TBC applications before it becomes a reliable industry method. The spray capability and applicability of SPS process to achieve uniformity thickness and microstructure on curved substrates were emphasized in designed spray trials to simulate the coating fabrication onto industrial turbine parts with complex configurations. The performances of the SPS-TBCs were tested in erosion, falling ballistic impact and indentational loading tests as to evaluate SPS-TBC performances in simulated turbine service conditions. Finally, a turbine blade was coated and sectioned to verify SPS sprayability in multiple critical sections. The SPS trials and test results demonstrated that SPS process is promising for innovative TBCs, but some challenges need to be addressed and resolved before it becomes an economic and capable industrial process, especially for complex turbine components.

Comparison of the signal-to-noise characteristics of quantum versus thermal ghost imaging

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

O'Sullivan, Malcolm N.; Chan, Kam Wai Clifford; Boyd, Robert W.

2010-11-15

We present a theoretical comparison of the signal-to-noise characteristics of quantum versus thermal ghost imaging. We first calculate the signal-to-noise ratio of each process in terms of its controllable experimental conditions. We show that a key distinction is that a thermal ghost image always resides on top of a large background; the fluctuations in this background constitutes an intrinsic noise source for thermal ghost imaging. In contrast, there is a negligible intrinsic background to a quantum ghost image. However, for practical reasons involving achievable illumination levels, acquisition times for thermal ghost images are often much shorter than those for quantummore » ghost images. We provide quantitative predictions for the conditions under which each process provides superior performance. Our conclusion is that each process can provide useful functionality, although under complementary conditions.« less

Computational Simulation of Thermal and Spattering Phenomena and Microstructure in Selective Laser Melting of Inconel 625

NASA Astrophysics Data System (ADS)

Özel, Tuğrul; Arısoy, Yiğit M.; Criales, Luis E.

Computational modelling of Laser Powder Bed Fusion (L-PBF) processes such as Selective laser Melting (SLM) can reveal information that is hard to obtain or unobtainable by in-situ experimental measurements. A 3D thermal field that is not visible by the thermal camera can be obtained by solving the 3D heat transfer problem. Furthermore, microstructural modelling can be used to predict the quality and mechanical properties of the product. In this paper, a nonlinear 3D Finite Element Method based computational code is developed to simulate the SLM process with different process parameters such as laser power and scan velocity. The code is further improved by utilizing an in-situ thermal camera recording to predict spattering which is in turn included as a stochastic heat loss. Then, thermal gradients extracted from the simulations applied to predict growth directions in the resulting microstructure.

Relativistic thermal plasmas - Effects of magnetic fields

NASA Technical Reports Server (NTRS)

Araki, S.; Lightman, A. P.

1983-01-01

Processes and equilibria in finite, relativistic, thermal plasmas are investigated, taking into account electron-positron creation and annihilation, photon production by internal processes, and photon production by a magnetic field. Inclusion of the latter extends previous work on such plasmas. The basic relations for thermal, Comptonized synchrotron emission are analyzed, including emission and absorption without Comptonization, Comptonized thermal synchrotron emission, and the Comptonized synchrotron and bremsstrahlung luminosities. Pair equilibria are calculated, including approximations and dimensionless parameters, the pair balance equation, maximum temperatures and field strengths, and individual models and cooling curves.

Processing line for industrial radiation-thermal synthesis of doped lithium ferrite powders

NASA Astrophysics Data System (ADS)

Surzhikov, A. P.; Galtseva, O. V.; Vasendina, E. A.; Vlasov, V. A.; Nikolaev, E. V.

2016-02-01

The paper considers the issues of industrial production of doped lithium ferrite powders by radiation-thermal method. A technological scheme of the processing line is suggested. The radiation-thermal technological scheme enables production of powders with technical characteristics close to the required ones under relatively low temperature annealing conditions without intermediate mixing. The optimal conditions of the radiation-thermal synthesis are achieved isothermally under irradiation by the electron beam with energy of 2.5 MeV in the temperature range of 700-750 0C within- 120 min.

Endogenous functional compounds in Korean native chicken meat are dependent on sex, thermal processing and meat cut.

PubMed

Jayasena, Dinesh D; Jung, Samooel; Kim, Sun Hyo; Kim, Hyun Joo; Alahakoon, Amali U; Lee, Jun Heon; Jo, Cheorun

2015-03-15

In this study the effects of sex, meat cut and thermal processing on the carnosine, anserine, creatine, betaine and carnitine contents of Korean native chicken (KNC) meat were determined. Forty 1-day-old chicks (20 chicks of each sex) from a commercial KNC strain (Woorimatdag™) were reared under similar standard commercial conditions with similar diets, and ten birds of each sex were randomly selected and slaughtered at 14 weeks of age. Raw and cooked meat samples were prepared from both breast and leg meats and analyzed for the aforementioned functional compounds. Female KNCs had significantly higher betaine and creatine contents. The breast meat showed significantly higher carnosine and anserine contents, whereas the leg meat had a higher betaine and carnitine content. The content of all functional compounds was significantly depleted by thermal processing. This study confirms that KNC meat is a good source of the above-mentioned functional compounds, which can be considered attractive nutritional quality factors. However, their concentrations were significantly affected by thermal processing conditions, meat cut and sex. Further experiments are needed to select the best thermal processing method to preserve these functional compounds. © 2014 Society of Chemical Industry.

In Situ Acoustic Monitoring of Thermal Spray Process Using High-Frequency Impulse Measurements

NASA Astrophysics Data System (ADS)

Tillmann, Wolfgang; Walther, Frank; Luo, Weifeng; Haack, Matthias; Nellesen, Jens; Knyazeva, Marina

2018-01-01

In order to guarantee their protective function, thermal spray coatings must be free from cracks, which expose the substrate surface to, e.g., corrosive media. Cracks in thermal spray coatings are usually formed because of tensile residual stresses. Most commonly, the crack occurrence is determined after the thermal spraying process by examination of metallographic cross sections of the coating. Recent efforts focus on in situ monitoring of crack formation by means of acoustic emission analysis. However, the acoustic signals related to crack propagation can be absorbed by the noise of the thermal spraying process. In this work, a high-frequency impulse measurement technique was applied to separate different acoustic sources by visualizing the characteristic signal of crack formation via quasi-real-time Fourier analysis. The investigations were carried out on a twin wire arc spraying process, utilizing FeCrBSi as a coating material. The impact of the process parameters on the acoustic emission spectrum was studied. Acoustic emission analysis enables to obtain global and integral information on the formed cracks. The coating morphology and coating defects were inspected using light microscopy on metallographic cross sections. Additionally, the resulting crack patterns were imaged in 3D by means of x-ray microtomography.

Theoretical Estimation of Thermal Effects in Drilling of Woven Carbon Fiber Composite

PubMed Central

Díaz-Álvarez, José; Olmedo, Alvaro; Santiuste, Carlos; Miguélez, María Henar

2014-01-01

Carbon Fiber Reinforced Polymer (CFRPs) composites are extensively used in structural applications due to their attractive properties. Although the components are usually made near net shape, machining processes are needed to achieve dimensional tolerance and assembly requirements. Drilling is a common operation required for further mechanical joining of the components. CFRPs are vulnerable to processing induced damage; mainly delamination, fiber pull-out, and thermal degradation, drilling induced defects being one of the main causes of component rejection during manufacturing processes. Despite the importance of analyzing thermal phenomena involved in the machining of composites, only few authors have focused their attention on this problem, most of them using an experimental approach. The temperature at the workpiece could affect surface quality of the component and its measurement during processing is difficult. The estimation of the amount of heat generated during drilling is important; however, numerical modeling of drilling processes involves a high computational cost. This paper presents a combined approach to thermal analysis of composite drilling, using both an analytical estimation of heat generated during drilling and numerical modeling for heat propagation. Promising results for indirect detection of risk of thermal damage, through the measurement of thrust force and cutting torque, are obtained. PMID:28788685

In-situ grown MgO-ZnO ceramic coating with high thermal emittance on Mg alloy by plasma electrolytic oxidation

NASA Astrophysics Data System (ADS)

Li, Hang; Lu, Songtao; Qin, Wei; Wu, Xiaohong

2017-07-01

Intense solar radiation and internal heat generation determine the equilibrium temperature of an in-orbit spacecraft. Thermal control coatings with low solar absorptance and high thermal emittance effectively maintain the thermal equilibrium within safe operating limits for exposed, miniaturized and highly integrated components. A novel ceramic coating with high thermal emittance and good adhesion was directly prepared on the Mg substrate using an economical process of controlled plasma electrolytic oxidation (PEO) in the electrolyte containing ZnSO4. XRD and XPS results showed that this coating was mainly composed of the MgO phase as well as an unusual ZnO crystalline phase. The adhesive strength between the coating and substrate determined by a pull-off test revealed an excellent adhesion. Thermal and optical properties test revealed that the coating exhibited a high infrared emittance of 0.88 (2-16 μm) and low solar absorptance of 0.35 (200-2500 nm). The result indicated that the formation of ZnO during the PEO process played an important role in the improvement of the coating emittance. The process developed provides a simple surface method for improving the thermal emittance of Mg alloy, which presents a promising application prospect in the thermal management of the spacecraft.

Studying the processes relating to oxidation of organic substances contained in the coolant of thermal and nuclear power stations

NASA Astrophysics Data System (ADS)

Khodyrev, B. N.; Krichevtsov, A. L.; Sokolyuk, A. A.

2010-07-01

A radical-chain mechanism governing thermal-oxidation destruction of organic substances contained in the coolant of thermal and nuclear power stations is considered. Hypotheses on the chemical nature of antioxidation properties of amines are presented. Theoretical conjectures about the fundamental processes through which protective amine films are formed on the surface of metals are suggested.

Continuous Processing of High Thermal Conductivity Polyethylene Fibers and Sheets

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

None

2016-12-01

This factsheet describes a project that developed a new, continuous manufacturing process to make high molecular weight, high thermal conductivity polyethylene fibers and sheets to replace metals and ceramics in heat transfer applications.

PVD thermal barrier coating applications and process development for aircraft engines

NASA Astrophysics Data System (ADS)

Rigney, D. V.; Viguie, R.; Wortman, D. J.; Skelly, D. W.

1997-06-01

Thermal barrier coatings (TBCs) have been developed for application to aircraft engine components to improve service life in an increasingly hostile thermal environment. The choice of TBC type is related to the component, intended use, and economics. Selection of electron beam physical vapor deposition proc-essing for turbine blade is due in part to part size, surface finish requirements, thickness control needs, and hole closure issues. Process development of PVD TBCs has been carried out at several different sites, including GE Aircraft Engines (GEAE). The influence of processing variables on microstructure is dis-cussed, along with the GEAE development coater and initial experiences of pilot line operation.

Key issues in the thermal design of spaceborne cryogenic infrared instruments

NASA Astrophysics Data System (ADS)

Schember, Helene R.; Rapp, Donald

1992-12-01

Thermal design and analysis play an integral role in the development of spaceborne cryogenic infrared (IR) instruments. From conceptual sketches to final testing, both direct and derived thermal requirements place significant constraints on the instrument design. Although in practice these thermal requirements are interdependent, the sources of most thermal constraints may be grouped into six distinct categories. These are: (1) Detector temperatures, (2) Optics temperatures, (3) Pointing or alignment stability, (4) Mission lifetime, (5) Orbit, and (6) Test and Integration. In this paper, we discuss these six sources of thermal requirements with particular regard to development of instrument packages for low background infrared astronomical observatories. In the end, the thermal performance of these instruments must meet a set of thermal requirements. The development of these requirements is typically an ongoing and interactive process, however, and the thermal design must maintain flexibility and robustness throughout the process. The thermal (or cryogenic) engineer must understand the constraints imposed by the science requirements, the specific hardware, the observing environment, the mission design, and the testing program. By balancing these often competing factors, the system-oriented thermal engineer can work together with the experiment team to produce an effective overall design of the instrument.

[Thermal energy utilization analysis and energy conservation measures of fluidized bed dryer].

PubMed

Xing, Liming; Zhao, Zhengsheng

2012-07-01

To propose measures for enhancing thermal energy utilization by analyzing drying process and operation principle of fluidized bed dryers,in order to guide optimization and upgrade of fluidized bed drying equipment. Through a systematic analysis on drying process and operation principle of fluidized beds,the energy conservation law was adopted to calculate thermal energy of dryers. The thermal energy of fluidized bed dryers is mainly used to make up for thermal consumption of water evaporation (Qw), hot air from outlet equipment (Qe), thermal consumption for heating and drying wet materials (Qm) and heat dissipation to surroundings through hot air pipelines and cyclone separators. Effective measures and major approaches to enhance thermal energy utilization of fluidized bed dryers were to reduce exhaust gas out by the loss of heat Qe, recycle dryer export air quantity of heat, preserve heat for dry towers, hot air pipes and cyclone separators, dehumidify clean air in inlets and reasonably control drying time and air temperature. Such technical parameters such air supply rate, air inlet temperature and humidity, material temperature and outlet temperature and humidity are set and controlled to effectively save energy during the drying process and reduce the production cost.

Radiative-conductive inverse problem for lumped parameter systems

NASA Astrophysics Data System (ADS)

Alifanov, O. M.; Nenarokomov, A. V.; Gonzalez, V. M.

2008-11-01

The purpose of this paper is to introduce a iterative regularization method in the research of radiative and thermal properties of materials with applications in the design of Thermal Control Systems (TCS) of spacecrafts. In this paper the radiative and thermal properties (emissivity and thermal conductance) of a multilayered thermal-insulating blanket (MLI), which is a screen-vacuum thermal insulation as a part of the (TCS) for perspective spacecrafts, are estimated. Properties of the materials under study are determined in the result of temperature and heat flux measurement data processing based on the solution of the Inverse Heat Transfer Problem (IHTP) technique. Given are physical and mathematical models of heat transfer processes in a specimen of the multilayered thermal-insulating blanket located in the experimental facility. A mathematical formulation of the inverse heat conduction problem is presented too. The practical testing were performed for specimen of the real MLI.

Improvement of Sol-Gel Derived PbZrxTi1-xO3 Film Properties Using Thermal Press Treatment

NASA Astrophysics Data System (ADS)

Kaneda, Toshihiko; Kim, Joo-Nam; Tokumitsu, Eisuke; Shimoda, Tatsuya

2010-09-01

A thermal press treatment was introduced in the sol-gel process of PbZrxTi1-xO3 (PZT) thin films for the first time and the crystalline and electrical characteristics of the PZT films were investigated. The thermal press treatment was applied to the amorphous PZT gel film before crystallization annealing. It is found that the crystalline orientation and grain size of the PZT film fabricated with the thermal press treatment are different from those of the film fabricated by the conventional sol-gel process without the thermal press treatment, even though the crystallization conditions are exactly the same. It is demonstrated that the electrical properties, especially leakage current density and breakdown field, are significantly improved for the PZT film fabricated with the thermal press treatment. Furthermore, we also demonstrate that the fatigue property is improved by introducing the thermal press treatment.

Advanced oxidation technology for H2S odor gas using non-thermal plasma

NASA Astrophysics Data System (ADS)

Tao, ZHU; Ruonan, WANG; Wenjing, BIAN; Yang, CHEN; Weidong, JING

2018-05-01

Non-thermal plasma technology is a new type of odor treatment processing. We deal with H2S from waste gas emission using non-thermal plasma generated by dielectric barrier discharge. On the basis of two criteria, removal efficiency and absolute removal amount, we deeply investigate the changes in electrical parameters and process parameters, and the reaction process of the influence of ozone on H2S gas removal. The experimental results show that H2S removal efficiency is proportional to the voltage, frequency, power, residence time and energy efficiency, while it is inversely proportional to the initial concentration of H2S gas, and ozone concentration. This study lays the foundations of non-thermal plasma technology for further commercial application.

Development of NASA's Sample Cartridge Assembly: Summary of GEDS Design, Development Testing, and Thermal Analyses

NASA Technical Reports Server (NTRS)

O'Connor, Brian; Hernandez, Deborah; Hornsby, Linda; Brown, Maria; Horton-Mullins, Kathryn

2017-01-01

Outline: Background of ISS (International Space Station) Material Science Research Rack; NASA SCA (Sample Cartridge Assembly) Design; GEDS (Gravitational Effects in Distortion in Sintering) Experiment Ampoule Design; Development Testing Summary; Thermal Modeling and Analysis. Summary: GEDS design development challenging (GEDS Ampoule design developed through MUGS (Microgravity) testing; Short duration transient sample processing; Unable to measure sample temperatures); MUGS Development testing used to gather data (Actual LGF (Low Gradient Furnace)-like furnace response; Provided sample for sintering evaluation); Transient thermal model integral to successful GEDS experiment (Development testing provided furnace response; PI (Performance Indicator) evaluation of sintering anchored model evaluation of processing durations; Thermal transient model used to determine flight SCA sample processing profiles).

Optical/thermal analysis methodology for a space-qualifiable RTP furnace

NASA Technical Reports Server (NTRS)

Bugby, D.; Dardarian, S.; Cole, E.

1993-01-01

A methodology to predict the coupled optical/thermal performance of a reflective cavity heating system was developed and a laboratory test to verify the method was carried out. The procedure was utilized to design a rapid thermal processing (RTP) furnace for the Robot-Operated Material Processing in Space (ROMPS) Program which is a planned STS HH-G canister experiment involving robotics and material processing in microgravity. The laboratory test employed a tungsten-halogen reflector/lamp to heat thin, p-type silicon wafers. Measurements instrumentation consisted of 5-mil Pt/Pt-Rh thermocouples and an optical pyrometer. The predicted results, utilizing an optical ray-tracing program and a lumped-capacitance thermal analyzer, showed good agreement with the measured data for temperatures exceeding 1300 C.

In-Process Thermal Imaging of the Electron Beam Freeform Fabrication Process

NASA Technical Reports Server (NTRS)

Taminger, Karen M.; Domack, Christopher S.; Zalameda, Joseph N.; Taminger, Brian L.; Hafley, Robert A.; Burke, Eric R.

2016-01-01

Researchers at NASA Langley Research Center have been developing the Electron Beam Freeform Fabrication (EBF3) metal additive manufacturing process for the past 15 years. In this process, an electron beam is used as a heat source to create a small molten pool on a substrate into which wire is fed. The electron beam and wire feed assembly are translated with respect to the substrate to follow a predetermined tool path. This process is repeated in a layer-wise fashion to fabricate metal structural components. In-process imaging has been integrated into the EBF3 system using a near-infrared (NIR) camera. The images are processed to provide thermal and spatial measurements that have been incorporated into a closed-loop control system to maintain consistent thermal conditions throughout the build. Other information in the thermal images is being used to assess quality in real time by detecting flaws in prior layers of the deposit. NIR camera incorporation into the system has improved the consistency of the deposited material and provides the potential for real-time flaw detection which, ultimately, could lead to the manufacture of better, more reliable components using this additive manufacturing process.

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

Romero, R.; Singh, R.P.; Brown, D.

A thermal-energy accounting study was conducted at an apple processing plant. An analysis is given of thermal energy use and thermal efficiencies of an apple-juice single-effect evaporator and an apple-sauce cooker. 3 refs.

Fluidized bed silicon deposition from silane

NASA Technical Reports Server (NTRS)

Hsu, George C. (Inventor); Levin, Harry (Inventor); Hogle, Richard A. (Inventor); Praturi, Ananda (Inventor); Lutwack, Ralph (Inventor)

1982-01-01

A process and apparatus for thermally decomposing silicon containing gas for deposition on fluidized nucleating silicon seed particles is disclosed. Silicon seed particles are produced in a secondary fluidized reactor by thermal decomposition of a silicon containing gas. The thermally produced silicon seed particles are then introduced into a primary fluidized bed reactor to form a fluidized bed. Silicon containing gas is introduced into the primary reactor where it is thermally decomposed and deposited on the fluidized silicon seed particles. Silicon seed particles having the desired amount of thermally decomposed silicon product thereon are removed from the primary fluidized reactor as ultra pure silicon product. An apparatus for carrying out this process is also disclosed.

Fluidized bed silicon deposition from silane

NASA Technical Reports Server (NTRS)

Hsu, George (Inventor); Levin, Harry (Inventor); Hogle, Richard A. (Inventor); Praturi, Ananda (Inventor); Lutwack, Ralph (Inventor)

1984-01-01

A process and apparatus for thermally decomposing silicon containing gas for deposition on fluidized nucleating silicon seed particles is disclosed. Silicon seed particles are produced in a secondary fluidized reactor by thermal decomposition of a silicon containing gas. The thermally produced silicon seed particles are then introduced into a primary fluidized bed reactor to form a fludized bed. Silicon containing gas is introduced into the primary reactor where it is thermally decomposed and deposited on the fluidized silicon seed particles. Silicon seed particles having the desired amount of thermally decomposed silicon product thereon are removed from the primary fluidized reactor as ultra pure silicon product. An apparatus for carrying out this process is also disclosed.

USAF solar thermal applications case studies

NASA Technical Reports Server (NTRS)

1981-01-01

The potential of solar energy technologies to meet mission related applications for process heat was investigated. The reduction of the dependence of military installations on fossil fuels by promoting the use of more abundant resources where liquid hydrocarbons and natural gas are now used is examined. The evaluation and utilization of renewable energy systems to provide process heat and space heating are emphasized. The application of thermal energy systems is divided into four steps: (1) investigation of the potential operational cost effectiveness of selected thermal technologies; (2) selection of a site and preliminary design of point focussing solar thermal plant; (3) construction and test of an engineering prototype; and (4) installation and operation of a solar thermal energy plant.

Parameter Identification Of Multilayer Thermal Insulation By Inverse Problems

NASA Astrophysics Data System (ADS)

Nenarokomov, Aleksey V.; Alifanov, Oleg M.; Gonzalez, Vivaldo M.

2012-07-01

The purpose of this paper is to introduce an iterative regularization method in the research of radiative and thermal properties of materials with further applications in the design of Thermal Control Systems (TCS) of spacecrafts. In this paper the radiative and thermal properties (heat capacity, emissivity and thermal conductance) of a multilayered thermal-insulating blanket (MLI), which is a screen-vacuum thermal insulation as a part of the (TCS) for perspective spacecrafts, are estimated. Properties of the materials under study are determined in the result of temperature and heat flux measurement data processing based on the solution of the Inverse Heat Transfer Problem (IHTP) technique. Given are physical and mathematical models of heat transfer processes in a specimen of the multilayered thermal-insulating blanket located in the experimental facility. A mathematical formulation of the IHTP, based on sensitivity function approach, is presented too. The practical testing was performed for specimen of the real MLI. This paper consists of recent researches, which developed the approach suggested at [1].

A Knowledge Database on Thermal Control in Manufacturing Processes

NASA Astrophysics Data System (ADS)

Hirasawa, Shigeki; Satoh, Isao

A prototype version of a knowledge database on thermal control in manufacturing processes, specifically, molding, semiconductor manufacturing, and micro-scale manufacturing has been developed. The knowledge database has search functions for technical data, evaluated benchmark data, academic papers, and patents. The database also displays trends and future roadmaps for research topics. It has quick-calculation functions for basic design. This paper summarizes present research topics and future research on thermal control in manufacturing engineering to collate the information to the knowledge database. In the molding process, the initial mold and melt temperatures are very important parameters. In addition, thermal control is related to many semiconductor processes, and the main parameter is temperature variation in wafers. Accurate in-situ temperature measurment of wafers is important. And many technologies are being developed to manufacture micro-structures. Accordingly, the knowledge database will help further advance these technologies.

Low-Energy Water Recovery from Subsurface Brines

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

Choi, Young Chul; Kim, Gyu Dong; Hendren, Zachary

A novel non-aqueous phase solvent (NAS) desalination process was proposed and developed in this research project. The NAS desalination process uses less energy than thermal processes, doesn’t require any additional chemicals for precipitation, and can be utilized to treat high TDS brine. In this project, our experimental work determined that water solubility changes and selective absorption are the key characteristics of NAS technology for successful desalination. Three NAS desalination mechanisms were investigated: (1) CO2 switchable, (2) high-temp absorption to low-temp desorption (thermally switchable), and (3) low-temp absorption to high-temp desorption (thermally switchable). Among these mechanisms, thermally switchable (low-temp absorption tomore » high-temp desorption) showed the highest water recovery and relatively high salt rejection. A test procedure for semi-continuous, bench scale NAS desalination process was also developed and used to assess performance under a range of conditions.« less

Monitoring non-thermal plasma processes for nanoparticle synthesis

NASA Astrophysics Data System (ADS)

Mangolini, Lorenzo

2017-09-01

Process characterization tools have played a crucial role in the investigation of dusty plasmas. The presence of dust in certain non-thermal plasma processes was first detected by laser light scattering measurements. Techniques like laser induced particle explosive evaporation and ion mass spectrometry have provided the experimental evidence necessary for the development of the theory of particle nucleation in silane-containing non-thermal plasmas. This review provides first a summary of these early efforts, and then discusses recent investigations using in situ characterization techniques to understand the interaction between nanoparticles and plasmas. The advancement of such monitoring techniques is necessary to fully develop the potential of non-thermal plasmas as unique materials synthesis and processing platforms. At the same time, the strong coupling between materials and plasma properties suggest that it is also necessary to advance techniques for the measurement of plasma properties while in presence of dust. Recent progress in this area will be discussed.

Composite material having high thermal conductivity and process for fabricating same

DOEpatents

Colella, N.J.; Davidson, H.L.; Kerns, J.A.; Makowiecki, D.M.

1998-07-21

A process is disclosed for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost. 7 figs.

Process for fabricating composite material having high thermal conductivity

DOEpatents

Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

2001-01-01

A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

Composite material having high thermal conductivity and process for fabricating same

DOEpatents

Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

1998-01-01

A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

76 FR 11891 - Temperature-Indicating Devices; Thermally Processed Low-Acid Foods Packaged in Hermetically...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-03

... contain mercury will eliminate concerns about potential contamination of the food or the processing... Vol. 76 Thursday, No. 42 March 3, 2011 Part III Department of Health and Human Services Food and Drug Administration 21 CFR Part 113 Temperature-Indicating Devices; Thermally Processed Low-Acid Foods...

SUPERFUND TREATABILITY CLEARINGHOUSE: TECHNOLOGY DEMONSTRATION OF A THERMAL DESORPTION/UV PHOTOLYSIS PROCESS FOR DECONTAMINATING SOILS CONTAINING HERBICIDE ORANGE

EPA Science Inventory

This treatability study report presents the results of laboratory and field tests on the effectiveness of a new decontamination process for soils containing 2,4-D/2,4,5-T and traces of dioxin. The process employs three operations, thermal desorption, condensation and absorp...

Effects of protein and phosphate buffer concentrations on thermal denaturation of lysozyme analyzed by isoconversional method.

PubMed

Cao, X M; Tian, Y; Wang, Z Y; Liu, Y W; Wang, C X

2016-07-03

Thermal denaturation of lysozymes was studied as a function of protein concentration, phosphate buffer concentration, and scan rate using differential scanning calorimetry (DSC), which was then analyzed by the isoconversional method. The results showed that lysozyme thermal denaturation was only slightly affected by the protein concentration and scan rate. When the protein concentration and scan rate increased, the denaturation temperature (Tm) also increased accordingly. On the contrary, the Tm decreased with the increase of phosphate buffer concentration. The denaturation process of lysozymes was accelatated and the thermal stability was reduced with the increase of phosphate concentration. One part of degeneration process was not reversible where the aggregation occurred. The other part was reversible. The apparent activation energy (Ea) was computed by the isoconversional method. It decreased with the increase of the conversion ratio (α). The observed denaturation process could not be described by a simple reaction mechanism. It was not a process involving 2 standard reversible states, but a multi-step process. The new opportunities for investigating the kinetics process of protein denaturation can be supplied by this novel isoconversional method.

The processing of aluminum gasarites via thermal decomposition of interstitial hydrides

NASA Astrophysics Data System (ADS)

Licavoli, Joseph J.

Gasarite structures are a unique type of metallic foam containing tubular pores. The original methods for their production limited them to laboratory study despite appealing foam properties. Thermal decomposition processing of gasarites holds the potential to increase the application of gasarite foams in engineering design by removing several barriers to their industrial scale production. The following study characterized thermal decomposition gasarite processing both experimentally and theoretically. It was found that significant variation was inherent to this process therefore several modifications were necessary to produce gasarites using this method. Conventional means to increase porosity and enhance pore morphology were studied. Pore morphology was determined to be more easily replicated if pores were stabilized by alumina additions and powders were dispersed evenly. In order to better characterize processing, high temperature and high ramp rate thermal decomposition data were gathered. It was found that the high ramp rate thermal decomposition behavior of several hydrides was more rapid than hydride kinetics at low ramp rates. This data was then used to estimate the contribution of several pore formation mechanisms to the development of pore structure. It was found that gas-metal eutectic growth can only be a viable pore formation mode if non-equilibrium conditions persist. Bubble capture cannot be a dominant pore growth mode due to high bubble terminal velocities. Direct gas evolution appears to be the most likely pore formation mode due to high gas evolution rate from the decomposing particulate and microstructural pore growth trends. The overall process was evaluated for its economic viability. It was found that thermal decomposition has potential for industrialization, but further refinements are necessary in order for the process to be viable.

Numerical investigation of thermal and residual stress of sapphire during c-axis vertical Bridgman growth process considering the solidification history effect

NASA Astrophysics Data System (ADS)

Hwang, Ji Hoon; Lee, Young Cheol; Lee, Wook Jin

2018-01-01

Sapphire single crystals have been highlighted for epitaxial of gallium nitride films in high-power laser and light emitting diode industries. In this study, the evolution of thermally induced stress in sapphire during the vertical Bridgman crystal growth process was investigated using a finite element model that simplified the real Bridgman process. A vertical Bridgman process of cylindrical sapphire crystal with a diameter of 50 mm was considered for the model. The solidification history effect during the growth was modeled by the quite element technique. The effects of temperature gradient, seeding interface shape and seeding position on the thermal stress during the process were discussed based on the finite element analysis results.

Discrimination techniques employing both reflective and thermal multispectral signals. [for remote sensor technology

NASA Technical Reports Server (NTRS)

Malila, W. A.; Crane, R. B.; Richardson, W.

1973-01-01

Recent improvements in remote sensor technology carry implications for data processing. Multispectral line scanners now exist that can collect data simultaneously and in registration in multiple channels at both reflective and thermal (emissive) wavelengths. Progress in dealing with two resultant recognition processing problems is discussed: (1) More channels mean higher processing costs; to combat these costs, a new and faster procedure for selecting subsets of channels has been developed. (2) Differences between thermal and reflective characteristics influence recognition processing; to illustrate the magnitude of these differences, some explanatory calculations are presented. Also introduced, is a different way to process multispectral scanner data, namely, radiation balance mapping and related procedures. Techniques and potentials are discussed and examples presented.

Effect of thermal and mechanical parameter’s damage numerical simulation cycling effects on defects in hot metal forming processes

NASA Astrophysics Data System (ADS)

El Amri, Abdelouahid; el yakhloufi Haddou, Mounir; Khamlichi, Abdellatif

2017-10-01

Damage mechanisms in hot metal forming processes are accelerated by mechanical stresses arising during Thermal and mechanical properties variations, because it consists of the materials with different thermal and mechanical loadings and swelling coefficients. In this work, 3D finite element models (FEM) are developed to simulate the effect of Temperature and the stresses on the model development, using a general purpose FE software ABAQUS. Explicit dynamic analysis with coupled Temperature displacement procedure is used for a model. The purpose of this research was to study the thermomechanical damage mechanics in hot forming processes. The important process variables and the main characteristics of various hot forming processes will also be discussed.

Self-sharpening-effect of nickel-diamond coatings sprayed by HVOF

NASA Astrophysics Data System (ADS)

Tillmann, W.; Brinkhoff, A.; Schaak, C.; Zajaczkowski, J.

2017-03-01

The durability of stone working and drilling tools is an increasingly significant requirement in industrial applications. These tools are mainly produced by brazing diamond metal matrix composites inserts to the tool body. These inserts are produced by sintering diamonds and metal powder (e.g. nickel). If the wear is too high, the diamonds will break out of the metal matrix and other diamonds will be uncovered. This effect is called self-sharpening. But diamonds are difficult to handle because of their thermal sensitivity. Due to their high thermal influence, manufacturing costs, and complicate route of manufacturing (first sintering, then brazing), there is a great need for alternative production methods for such tools. One alternative to produce wear-resistant and self-sharpening coatings are thermal spray processes as examined in this paper. An advantage of thermal spray processes is their smaller thermal influence on the diamond, due to the short dwelling time in the flame. To reduce the thermal influence during spraying, nickel coated diamonds were used in the HVOF-process (high velocity oxygen fuel process). The wear resistance was subsequently investigated by means of a standardized ball-on-disc test. Furthermore, a SEM (scanning electron microscope) was used to gain information about the wear-mechanism and the self-sharpening effect of the coating.

A thermal microprobe fabricated with wafer-stage processing

NASA Astrophysics Data System (ADS)

Zhang, Yongxia; Zhang, Yanwei; Blaser, Juliana; Sriram, T. S.; Enver, Ahsan; Marcus, R. B.

1998-05-01

A thermal microprobe has been designed and built for high resolution temperature sensing. The thermal sensor is a thin-film thermocouple junction at the tip of an atomic force microprobe (AFM) silicon probe needle. Only wafer-stage processing steps are used for the fabrication. For high resolution temperature sensing it is essential that the junction be confined to a short distance at the AFM tip. This confinement is achieved by a controlled photoresist coating process. Experiment prototypes have been made with an Au/Pd junction confined to within 0.5 μm of the tip, with the two metals separated elsewhere by a thin insulating oxide layer. Processing begins with double-polished, n-type, 4 in. diameter, 300-μm-thick silicon wafers. Atomically sharp probe tips are formed by a combination of dry and wet chemical etching, and oxidation sharpening. The metal layers are sputtering deposited and the cantilevers are released by a combination of KOH and dry etching. A resistively heated calibration device was made for temperature calibration of the thermal microprobe over the temperature range 25-110 °C. Over this range the thermal outputs of two microprobes are 4.5 and 5.6 μV/K and is linear. Thermal and topographical images are also obtained from a heated tungsten thin film fuse.

Preliminary Thermal-Mechanical Sizing of Metallic TPS: Process Development and Sensitivity Studies

NASA Technical Reports Server (NTRS)

Poteet, Carl C.; Abu-Khajeel, Hasan; Hsu, Su-Yuen

2002-01-01

The purpose of this research was to perform sensitivity studies and develop a process to perform thermal and structural analysis and sizing of the latest Metallic Thermal Protection System (TPS) developed at NASA LaRC (Langley Research Center). Metallic TPS is a key technology for reducing the cost of reusable launch vehicles (RLV), offering the combination of increased durability and competitive weights when compared to other systems. Accurate sizing of metallic TPS requires combined thermal and structural analysis. Initial sensitivity studies were conducted using transient one-dimensional finite element thermal analysis to determine the influence of various TPS and analysis parameters on TPS weight. The thermal analysis model was then used in combination with static deflection and failure mode analysis of the sandwich panel outer surface of the TPS to obtain minimum weight TPS configurations at three vehicle stations on the windward centerline of a representative RLV. The coupled nature of the analysis requires an iterative analysis process, which will be described herein. Findings from the sensitivity analysis are reported, along with TPS designs at the three RLV vehicle stations considered.

Thermal imaging as a smartphone application: exploring and implementing a new concept

NASA Astrophysics Data System (ADS)

Yanai, Omer

2014-06-01

Today's world is going mobile. Smartphone devices have become an important part of everyday life for billions of people around the globe. Thermal imaging cameras have been around for half a century and are now making their way into our daily lives. Originally built for military applications, thermal cameras are starting to be considered for personal use, enabling enhanced vision and temperature mapping for different groups of professional individuals. Through a revolutionary concept that turns smartphones into fully functional thermal cameras, we have explored how these two worlds can converge by utilizing the best of each technology. We will present the thought process, design considerations and outcome of our development process, resulting in a low-power, high resolution, lightweight USB thermal imaging device that turns Android smartphones into thermal cameras. We will discuss the technological challenges that we faced during the development of the product, and what are the system design decisions taken during the implementation. We will provide some insights we came across during this development process. Finally, we will discuss the opportunities that this innovative technology brings to the market.

Thermal Arc Spray Overview

NASA Astrophysics Data System (ADS)

Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

2013-06-01

Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

High-performance noncontact thermal diode via asymmetric nanostructures

NASA Astrophysics Data System (ADS)

Shen, Jiadong; Liu, Xianglei; He, Huan; Wu, Weitao; Liu, Baoan

2018-05-01

Electric diodes, though laying the foundation of modern electronics and information processing industries, suffer from ineffectiveness and even failure at high temperatures. Thermal diodes are promising alternatives to relieve above limitations, but usually possess low rectification ratios, and how to obtain a high-performance thermal rectification effect is still an open question. This paper proposes an efficient contactless thermal diode based on the near-field thermal radiation of asymmetric doped silicon nanostructures. The rectification ratio computed via exact scattering theories is demonstrated to be as high as 10 at a nanoscale gap distance and period, outperforming the counterpart flat-plate diode by more than one order of magnitude. This extraordinary performance mainly lies in the higher forward and lower reverse radiative heat flux within the low frequency band compared with the counterpart flat-plate diode, which is caused by a lower loss and smaller cut-off wavevector of nanostructures for the forward and reversed scheme, respectively. This work opens new routes to realize high performance thermal diodes, and may have wide applications in efficient thermal computing, thermal information processing, and thermal management.

Candidate thermal energy storage technologies for solar industrial process heat applications

NASA Technical Reports Server (NTRS)

Furman, E. R.

1979-01-01

A number of candidate thermal energy storage system elements were identified as having the potential for the successful application of solar industrial process heat. These elements which include storage media, containment and heat exchange are shown.

Thermal decay of rhodopsin: role of hydrogen bonds in thermal isomerization of 11-cis retinal in the binding site and hydrolysis of protonated Schiff base.

PubMed

Liu, Jian; Liu, Monica Yun; Nguyen, Jennifer B; Bhagat, Aditi; Mooney, Victoria; Yan, Elsa C Y

2009-07-01

Although thermal stability of the G protein-coupled receptor rhodopsin is directly related to its extremely low dark noise level and has recently generated considerable interest, the chemistry behind the thermal decay process of rhodopsin has remained unclear. Using UV-vis spectroscopy and HPLC analysis, we have demonstrated that the thermal decay of rhodopsin involves both hydrolysis of the protonated Schiff base and thermal isomerization of 11-cis to all-trans retinal. Examining the unfolding of rhodopsin by circular dichroism spectroscopy and measuring the rate of thermal isomerization of 11-cis retinal in solution, we conclude that the observed thermal isomerization of 11-cis to all-trans retinal happens when 11-cis retinal is in the binding pocket of rhodopsin. Furthermore, we demonstrate that solvent deuterium isotope effects are involved in the thermal decay process by decreasing the rates of thermal isomerization and hydrolysis, suggesting that the rate-determining step of these processes involves breaking hydrogen bonds. These results provide insight into understanding the critical role of an extensive hydrogen-bonding network on stabilizing the inactive state of rhodopsin and contribute to our current understanding of the low dark noise level of rhodopsin, which enables this specialized protein to function as an extremely sensitive biological light detector. Because similar hydrogen-bonding networks have also been suggested by structural analysis of two other GPCRs, beta1 and beta2 adrenergic receptors, our results could reveal a general role of hydrogen bonds in facilitating GPCR function.

Air Vehicle Integration and Technology Research (AVIATR). Delivery Order 0013: Nonlinear, Low-Order/Reduced-Order Modeling Applications and Demonstration

DTIC Science & Technology

2011-12-01

image) ................. 114 Figure 156 – Abaqus thermal model attempting to characterize the thermal profile seen in the test data...optimization process ... 118 Figure 159 – Thermal profile for optimized Abaqus thermal solution ....................................... 119 Figure 160 – LVDT...Coefficients of thermal expansion results ................................................................. 121 Table 12 – LVDT correlation results

Geometrical Effect on Thermal Conductivity of Unidirectional Fiber-Reinforced Polymer Composite along Different In-plane Orientations

NASA Astrophysics Data System (ADS)

Fang, Zenong; Li, Min; Wang, Shaokai; Li, Yanxia; Wang, Xiaolei; Gu, Yizhuo; Liu, Qianli; Tian, Jie; Zhang, Zuoguang

2017-11-01

This paper focuses on the anisotropic characteristics of the in-plane thermal conductivity of fiber-reinforced polymer composite based on experiment and simulation. Thermal conductivity along different in-plane orientations was measured by laser flash analysis (LFA) and steady-state heat flow method. Their heat transfer processes were simulated to reveal the geometrical effect on thermal conduction. The results show that the in-plane thermal conduction of unidirectional carbon-fiber-reinforced polymer composite is greatly influenced by the sample geometry at an in-plane orientation angle between 0° to 90°. By defining radius-to-thickness as a dimensionless shape factor for the LFA sample, the apparent thermal conductivity shows a dramatic change when the shape factor is close to the tangent of the orientation angle (tanθ). Based on finite element analysis, this phenomenon was revealed to correlate with the change of the heat transfer process. When the shape factor is larger than tanθ, the apparent thermal conductivity is consistent with the estimated value according to the theoretical model. For a sample with a shape factor smaller than tanθ, the apparent thermal conductivity shows a slow growth around a low value, which seriously deviates from the theory estimation. This phenomenon was revealed to correlate with the change of the heat transfer process from a continuous path to a zigzag path. These results will be helpful in optimizing the ply scheme of composite laminates for thermal management applications.

Effects Of Thermal Exchange On Material Flow During Steel Thixoextrusion Process

NASA Astrophysics Data System (ADS)

Eric, Becker; Guochao, Gu; Laurent, Langlois; Raphaël, Pesci; Régis, Bigot

2011-01-01

Semisolid processing is an innovative technology for near net-shape production of components, where the metallic alloys are processed in the semisolid state. Taking advantage of the thixotropic behavior of alloys in the semisolid state, significant progress has been made in semisolid processing. However, the consequences of such behavior on the flow during thixoforming are still not completely understood. To explore and better understand the influence of the different parameters on material flow during thixoextrusion process, thixoextrusion experiments were performed using the low carbon steel C38. The billet was partially melted at high solid fraction. Effects of various process parameters including the initial billet temperature, the temperature of die, the punch speed during process and the presence of a Ceraspray layer at the interface of tool and billet were investigated through experiments and simulation. After analyzing the results thus obtained, it was identified that the aforementioned parameters mainly affect thermal exchanges between die and part. The Ceraspray layer not only plays a lubricant role, but also acts as a thermal barrier at the interface of tool and billet. Furthermore, the thermal effects can affect the material flow which is composed of various distinct zones.

A simulation technique for predicting thickness of thermal sprayed coatings

NASA Technical Reports Server (NTRS)

Goedjen, John G.; Miller, Robert A.; Brindley, William J.; Leissler, George W.

1995-01-01

The complexity of many of the components being coated today using the thermal spray process makes the trial and error approach traditionally followed in depositing a uniform coating inadequate, thereby necessitating a more analytical approach to developing robotic trajectories. A two dimensional finite difference simulation model has been developed to predict the thickness of coatings deposited using the thermal spray process. The model couples robotic and component trajectories and thermal spraying parameters to predict coating thickness. Simulations and experimental verification were performed on a rotating disk to evaluate the predictive capabilities of the approach.

Design Optimization of Liquid Fueled High Velocity Oxy- Fuel Thermal Spraying Technique for Durable Coating for Fossil Power Systems

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

Choudhuri, Ahsan; Love, Norman

High-velocity oxy–fuel (HVOF) thermal spraying was developed in 1930 and has been commercially available for twenty-five years. HVOF thermal spraying has several benefits over the more conventional plasma spray technique including a faster deposition rate which leads to quicker turn-around, with more durable coatings and higher bond strength, hardness and wear resistance due to a homogeneous distribution of the sprayed particles. HVOF thermal spraying is frequently used in engineering to deposit cermets, metallic alloys, composites and polymers, to enhance product life and performance. HVOF thermal spraying system is a highly promising technique for applying durable coatings on structural materials formore » corrosive and high temperature environments in advanced ultra-supercritical coal- fired (AUSC) boilers, steam turbines and gas turbines. HVOF thermal spraying is the preferred method for producing coatings with low porosity and high adhesion. HVOF thermal spray process has been shown to be one of the most efficient techniques to deposit high performance coatings at moderate cost. Variables affecting the deposit formation and coating properties include hardware characteristics such as nozzle geometry and spraying distance and process parameters such as equivalence ratio, gas flow density, and powder feedstock. In the spray process, the powder particles experience very high speeds combined with fast heating to the powder material melting point or above. This high temperature causes evaporation of the powder, dissolution, and phase transformations. Due to the complex nature of the HVOF technique, the control and optimization of the process is difficult. In general, good coating quality with suitable properties and required performance for specific applications is the goal in producing thermal spray coatings. In order to reach this goal, a deeper understanding of the spray process as a whole is needed. Although many researchers studied commercial HVOF thermal spray systems, there exists a lack of fundamental understanding of the effect of hardware characteristics and operating parameters on HVOF thermally sprayed coatings. Motivated by these issues, this study is devoted to investigate the effect of hardware characteristics (e.g. spraying distance) and operating parameters (e.g. combustion chamber pressure, equivalence ratio, and total gas flow rate) on HVOF sprayed coatings using Inconel 718 alloy. The current study provides extensive understanding of several key operating and process parameters to optimize the next generation of HVOF thermally sprayed coatings for high temperature and harsh environment applications. A facility was developed to support this endeavor in a safe and efficient way, including a HVOF thermal spray system with a Data Acquisition and Remote Controls system (DARCS). The coatings microstructure and morphology were examined using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Nanoindentation.« less

Thermal Infrared Radiometric Calibration of the Entire Landsat 4, 5, and 7 Archive (1982-2010)

NASA Technical Reports Server (NTRS)

Schott, John R.; Hook, Simon J.; Barsi, Julia A.; Markham, Brian L.; Miller, Jonathan; Padula, Francis P.; Raqueno, Nina G.

2012-01-01

Landsat's continuing record of the thermal state of the earth's surface represents the only long term (1982 to the present) global record with spatial scales appropriate for human scale studies (i.e., tens of meters). Temperature drives many of the physical and biological processes that impact the global and local environment. As our knowledge of, and interest in, the role of temperature on these processes have grown, the value of Landsat data to monitor trends and process has also grown. The value of the Landsat thermal data archive will continue to grow as we develop more effective ways to study the long term processes and trends affecting the planet. However, in order to take proper advantage of the thermal data, we need to be able to convert the data to surface temperatures. A critical step in this process is to have the entire archive completely and consistently calibrated into absolute radiance so that it can be atmospherically compensated to surface leaving radiance and then to surface radiometric temperature. This paper addresses the methods and procedures that have been used to perform the radiometric calibration of the earliest sizable thermal data set in the archive (Landsat 4 data). The completion of this effort along with the updated calibration of the earlier (1985 1999) Landsat 5 data, also reported here, concludes a comprehensive calibration of the Landsat thermal archive of data from 1982 to the present

Impact of Reflow on the Output Characteristics of Piezoelectric Microelectromechanical System Devices

NASA Astrophysics Data System (ADS)

Nogami, Hirofumi; Kobayashi, Takeshi; Okada, Hironao; Masuda, Takashi; Maeda, Ryutaro; Itoh, Toshihiro

2012-09-01

An animal health monitoring system and a wireless sensor node aimed at preventing the spread of animal-transmitted diseases and improving pastoral efficiency which are especially suitable for chickens, were developed. The sensor node uses a piezoelectric microelectromechanical system (MEMS) device and an event-driven system that is activated by the movements of a chicken. The piezoelectric MEMS device has two functions: a) it measures the activity of a chicken and b) switches the micro-control unit (MCU) of the wireless sensor node from the sleep mode. The piezoelectric MEMS device is required to produce high output voltages when the chicken moves. However, after the piezoelectric MEMS device was reflowed to the wireless sensor node, the output voltages of the piezoelectric MEMS device decreased. The main reason for this might be the loss of residual polarization, which is affected by the thermal load during the reflow process. After the reflow process, we were not able to apply a voltage to the piezoelectric MEMS device; thus, the piezoelectric output voltage was not increased by repoling the piezoelectric MEMS device. To address the thermal load of the reflow process, we established a thermal poling treatment, which achieves a higher temperature than the reflow process. We found that on increasing the thermal poling temperature, the piezoelectric output voltages did not decreased low significantly. Thus, we considered that a thermal poling temperature higher than that of the reflow process prevents the piezoelectric output voltage reduction caused by the thermal load.

Thermal optimum design for tracking primary mirror of Space Telescope

NASA Astrophysics Data System (ADS)

Pan, Hai-jun; Ruan, Ping; Li, Fu; Wang, Hong-Wei

2011-08-01

In the conventional method, the structural parameters of primary mirror are usually optimized just by the requirement of mechanical performance. Because the influences of structural parameters on thermal stability are not taken fully into account in this simple method, the lightweight optimum design of primary mirror usually brings the bad thermal stability, especially in the complex environment. In order to obtain better thermal stability, a new method about structure-thermal optimum design of tracking primary mirror is discussed. During the optimum process, both the lightweight ratio and thermal stability will be taken into account. The structure-thermal optimum is introduced into the analysis process and commenced after lightweight design as the secondary optimum. Using the engineering analysis of software ANSYS, a parameter finite element analysis (FEA) model of mirror is built. On the premise of appropriate lightweight ratio, the RMS of structure-thermal deformation of mirror surface and lightweight ratio are assigned to be state variables, and the maximal RMS of temperature gradient load to be object variable. The results show that certain structural parameters of tracking primary mirror have different influences on mechanical performance and thermal stability, even they are opposite. By structure-thermal optimizing, the optimized mirror model discussed in this paper has better thermal stability than the old one under the same thermal loads, which can drastically reduce difficulty in thermal control.

Graphene nanoplatelets: Thermal diffusivity and thermal conductivity by the flash method

NASA Astrophysics Data System (ADS)

Potenza, M.; Cataldo, A.; Bovesecchi, G.; Corasaniti, S.; Coppa, P.; Bellucci, S.

2017-07-01

The present work deals with the measurement of thermo-physical properties of a freestanding sheet of graphene (thermal diffusivity and thermal conductivity), and their dependence on sample density as result of uniform mechanical compression. Thermal diffusivity of graphene nano-platelets (thin slabs) was measured by the pulse flash method. Obtained response data were processed with a specifically developed least square data processing algorithm. GNP specific heat was assumed from literature and thermal conductivity derived from thermal diffusivity, specific heat and density. Obtained results show a significant difference with respect to other porous media: the thermal diffusivity decreases as the density increases, while thermal conductivity increases for low and high densities, and remain fairly constant for the intermediate range. This can be explained by the very high thermal conductivity values reached by the nano-layers of graphene and the peculiar arrangement of platelets during the compression applied to the samples to get the desired density. Due to very high thermal conductivity of graphene layers, the obtained results show that thermal conductivity of conglomerates increases when there is an air reduction due to compression, and consequent density increases, with the number of contact points between platelets also increased. In the intermediate range (250 ≤ ρ ≤ 700 kg.m-3) the folding of platelets reduces density, without increasing the contact points of platelets, so thermal conductivity can slightly decrease.

The Maillard reaction and its control during food processing. The potential of emerging technologies.

PubMed

Jaeger, H; Janositz, A; Knorr, D

2010-06-01

The Maillard reaction between reducing sugars and amino acids is a common reaction in foods which undergo thermal processing. Desired consequences like the formation of flavor and brown color of some cooked foods but also the destruction of essential amino acids and the production of anti-nutritive compounds require the consideration of the Maillard reaction and relevant mechanisms for its control. This paper aims to exemplify the recent advances in food processing with regard to the controllability of heat-induced changes in the food quality. Firstly, improved thermal technologies, such as ohmic heating, which allows direct heating of the product and overcoming the heat transfer limitations of conventional thermal processing are presented in terms of their applicability to reduce the thermal exposure during food preservation. Secondly, non-thermal technologies such as high hydrostatic pressure and pulsed electric fields and their ability to extend the shelf life of food products without the application of heat, thus also preserving the quality attributes of the food, will be discussed. Finally, an innovative method for the removal of Maillard reaction substrates in food raw materials by the application of pulsed electric field cell disintegration and extraction as well as enzymatic conversion is presented in order to demonstrate the potential of the combination of processes to control the occurrence of the Maillard reaction in food processing. (c) 2009 Elsevier Masson SAS. All rights reserved.

Effect of power history on the shape and the thermal stress of a large sapphire crystal during the Kyropoulos process

NASA Astrophysics Data System (ADS)

Nguyen, Tran Phu; Chuang, Hsiao-Tsun; Chen, Jyh-Chen; Hu, Chieh

2018-02-01

In this study, the effect of the power history on the shape of a sapphire crystal and the thermal stress during the Kyropoulos process are numerically investigated. The simulation results show that the thermal stress is strongly dependent on the power history. The thermal stress distributions in the crystal for all growth stages produced with different power histories are also studied. The results show that high von Mises stress regions are found close to the seed of the crystal, the highly curved crystal surface and the crystal-melt interface. The maximum thermal stress, which occurs at the crystal-melt interface, increases significantly in value as the crystal expands at the crown. After this, there is reduction in the maximum thermal stress as the crystal lengthens. There is a remarkable enhancement in the maximum von Mises stress when the crystal-melt interface is close to the bottom of the crucible. There are two obvious peaks in the maximum Von Mises stress, at the end of the crown stage and in the final stage, when cracking defects can form. To alleviate this problem, different power histories are considered in order to optimize the process to produce the lowest thermal stress in the crystal. The optimal power history is found to produce a significant reduction in the thermal stress in the crown stage.

Comparison of three different wastewater sludge and their respective drying processes: Solar, thermal and reed beds - Impact on organic matter characteristics.

PubMed

Collard, Marie; Teychené, Benoit; Lemée, Laurent

2017-12-01

Drying process aims at minimising the volume of wastewater sludge (WWS) before disposal, however it can impact sludge characteristics. Due to its high content in organic matter (OM) and lipids, sludge are mainly valorised by land farming but can also be considered as a feedstock for biodiesel production. As sludge composition is a major parameter for the choice of disposal techniques, the objective of this study was to determine the influence of the drying process. To reach this goal, three sludges obtained from solar, reed beds and thermal drying processes were investigated at the global and molecular scales. Before the drying step the sludges presented similar physico-chemical (OM content, elemental analysis, pH, infrared spectra) characteristics and lipid contents. A strong influence of the drying process on lipids and humic-like substances contents was observed through OM fractionation. Thermochemolysis-GCMS of raw sludge and lipids revealed similar molecular content mainly constituted with steroids and fatty acids. Molecular changes were noticeable for thermal drying through differences in branched to linear fatty acids ratio. Finally the thermal drying induced a weakening of OM whereas the solar drying led to a complexification. These findings show that smooth drying processes such as solar or reed-beds are preferable for amendment production whereas thermal process leads to pellets with a high lipid content which could be considered for fuel production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development and validation of nonthermal and advanced thermal food safety intervention technologies

USDA-ARS?s Scientific Manuscript database

Alternative nonthermal and thermal food safety interventions are gaining acceptance by the food processing industry and consumers. These technologies include high pressure processing, ultraviolet and pulsed light, ionizing radiation, pulsed and radiofrequency electric fields, cold atmospheric plasm...

Thermal Radiometer Signal Processing Using Radiation Hard CMOS Application Specific Integrated Circuits for Use in Harsh Planetary Environments

NASA Technical Reports Server (NTRS)

Quilligan, G.; DuMonthier, J.; Aslam, S.; Lakew, B.; Kleyner, I.; Katz, R.

2015-01-01

Thermal radiometers such as proposed for the Europa Clipper flyby mission require low noise signal processing for thermal imaging with immunity to Total Ionizing Dose (TID) and Single Event Latchup (SEL). Described is a second generation Multi- Channel Digitizer (MCD2G) Application Specific Integrated Circuit (ASIC) that accurately digitizes up to 40 thermopile pixels with greater than 50 Mrad (Si) immunity TID and 174 MeV-sq cm/mg SEL. The MCD2G ASIC uses Radiation Hardened By Design (RHBD) techniques with a 180 nm CMOS process node.

Thermal Radiometer Signal Processing using Radiation Hard CMOS Application Specific Integrated Circuits for use in Harsh Planetary Environments

NASA Astrophysics Data System (ADS)

Quilligan, G.; DuMonthier, J.; Aslam, S.; Lakew, B.; Kleyner, I.; Katz, R.

2015-10-01

Thermal radiometers such as proposed for the Europa Clipper flyby mission [1] require low noise signal processing for thermal imaging with immunity to Total Ionizing Dose (TID) and Single Event Latchup (SEL). Described is a second generation Multi- Channel Digitizer (MCD2G) Application Specific Integrated Circuit (ASIC) that accurately digitizes up to 40 thermopile pixels with greater than 50 Mrad (Si) immunity TID and 174 MeV-cm2/mg SEL. The MCD2G ASIC uses Radiation Hardened By Design (RHBD) techniques with a 180 nm CMOS process node.

Processing and Properties Of Refractory Zirconium Diboride Composites For Use In High Temperature Applications

NASA Technical Reports Server (NTRS)

Stackpoole, Margaret; Gusman, M.; Ellerby, D.; Johnson, S. M.; Arnold, Jim (Technical Monitor)

2001-01-01

The Thermal Protection Materials and Systems Branch at NASA Ames Research Center is involved in the development of a class of refractory oxidation-resistant diboride composites termed Ultra High Temperature Ceramics or UHTCs. These composites have good high temperature properties making them candidate materials for thermal protection system (TPS) applications. The current research focuses on improving processing methods to develop more reliable composites with enhanced thermal and mechanical properties. This presentation will concentrate on the processing of ZrB2/SiC composites. Some preliminary mechanical properties and oxidation data will also be presented.

Fracture toughness of plasma-sprayed thermal barrier ceramics: Influence of processing, microstructure, and thermal aging

DOE PAGES

Dwivedi, Gopal; Viswanathan, Vaishak; Sampath, Sanjay; ...

2014-06-09

Fracture toughness has become one of the dominant design parameters that dictates the selection of materials and their microstructure to obtain durable thermal barrier coatings (TBCs). Much progress has been made in characterizing the fracture toughness of relevant TBC compositions in bulk form, and it has become apparent that this property is significantly affected by process-induced microstructural defects. In this investigation, a systematic study of the influence of coating microstructure on the fracture toughness of atmospheric plasma sprayed (APS) TBCs has been carried out. Yttria partially stabilized zirconia (YSZ) coatings were fabricated under different spray process conditions inducing different levelsmore » of porosity and interfacial defects. Fracture toughness was measured on free standing coatings in as-processed and thermally aged conditions using the double torsion technique. Results indicate significant variance in fracture toughness among coatings with different microstructures including changes induced by thermal aging. Comparative studies were also conducted on an alternative TBC composition, Gd 2Zr 2O 7 (GDZ), which as anticipated shows significantly lower fracture toughness compared to YSZ. Furthermore, the results from these studies not only point towards a need for process and microstructure optimization for enhanced TBC performance but also a framework for establishing performance metrics for promising new TBC compositions.« less

Identification of characteristic aroma compounds in raw and thermally processed African giant snail (Achatina fulica).

PubMed

Lasekan, Ola; Muniady, Megala; Lin, Mee; Dabaj, Fatma

2018-04-24

Food flavor appreciation is one of the first signals along with food appearance and texture encountered by consumers during eating of food. Also, it is well known that flavor can strongly influence consumer's acceptability judgment. The increase in the consumption of snail meat across the world calls for the need to research into the aroma compounds responsible for the distinctive aroma notes of processed snail meat. The odorants responsible for the unique aroma notes in thermally processed giant African snail meats were evaluated by means of aroma extract dilution analysis (AEDA), gas chromatography-olfactometry (GC-O) and odor activity values (OAVs) respectively. Results revealed significant differences in the aroma profiles of the raw and thermally processed snail meats. Whilst the aroma profile of the raw snail meat was dominated with the floral-like β-ionone and β-iso-methyl ionone, sweaty/cheesy-like butanoic acid, and the mushroom-like 1-octen-3-one, the boiled and fried samples were dominated with the thermally generated odorants like 2-methylpyrazine, 2,5-dimethylpyrazine, 2-acetylthiazole and 2-acetylpyridine. Finally, results have shown that sotolon, 2-acetyl-1-pyrroline, 2-furanmethanethiol, 2-methylbutanal, 1-octen-3-one, octanal, furanone, 2-methoxyphenol, 2-acetylpyridine, 2-acetylthiazole, and 2-methylpyrazine contributed to the overall aroma of the thermally processed snail meat.

Experimental Investigation of A Heat Pipe-Assisted Latent Heat Thermal Energy Storage System

NASA Astrophysics Data System (ADS)

Tiari, Saeed; Mahdavi, Mahboobe; Qiu, Songgang

2016-11-01

In the present work, different operation modes of a latent heat thermal energy storage system assisted by a heat pipe network were studied experimentally. Rubitherm RT55 enclosed by a vertical cylindrical container was used as the Phase Change Material (PCM). The embedded heat pipe network consisting of a primary heat pipe and an array of four secondary heat pipes were employed to transfer heat to the PCM. The primary heat pipe transports heat from the heat source to the heat sink. The secondary heat pipes transfer the extra heat from the heat source to PCM during charging process or retrieve thermal energy from PCM during discharging process. The effects of heat transfer fluid (HTF) flow rate and temperature on the thermal performance of the system were investigated for both charging and discharging processes. It was found that the HTF flow rate has a significant effect on the total charging time of the system. Increasing the HTF flow rate results in a remarkable increase in the system input thermal power. The results also showed that the discharging process is hardly affected by the HTF flow rate but HTF temperature plays an important role in both charging and discharging processes. The authors would like to acknowledge the financial supports by Temple University for the project.

Influence of Process Parameters on the Process Efficiency in Laser Metal Deposition Welding

NASA Astrophysics Data System (ADS)

Güpner, Michael; Patschger, Andreas; Bliedtner, Jens

Conventionally manufactured tools are often completely constructed of a high-alloyed, expensive tool steel. An alternative way to manufacture tools is the combination of a cost-efficient, mild steel and a functional coating in the interaction zone of the tool. Thermal processing methods, like laser metal deposition, are always characterized by thermal distortion. The resistance against the thermal distortion decreases with the reduction of the material thickness. As a consequence, there is a necessity of a special process management for the laser based coating of thin parts or tools. The experimental approach in the present paper is to keep the energy and the mass per unit length constant by varying the laser power, the feed rate and the powder mass flow. The typical seam parameters are measured in order to characterize the cladding process, define process limits and evaluate the process efficiency. Ways to optimize dilution, angular distortion and clad height are presented.

Optimizing Compliance and Thermal Conductivity of Plasma Sprayed Thermal Barrier Coatings via Controlled Powders and Processing Strategies

NASA Astrophysics Data System (ADS)

Tan, Yang; Srinivasan, Vasudevan; Nakamura, Toshio; Sampath, Sanjay; Bertrand, Pierre; Bertrand, Ghislaine

2012-09-01

The properties and performance of plasma-sprayed thermal barrier coatings (TBCs) are strongly dependent on the microstructural defects, which are affected by starting powder morphology and processing conditions. Of particular interest is the use of hollow powders which not only allow for efficient melting of zirconia ceramics but also produce lower conductivity and more compliant coatings. Typical industrial hollow spray powders have an assortment of densities resulting in masking potential advantages of the hollow morphology. In this study, we have conducted process mapping strategies using a novel uniform shell thickness hollow powder to control the defect microstructure and properties. Correlations among coating properties, microstructure, and processing reveal feasibility to produce highly compliant and low conductivity TBC through a combination of optimized feedstock and processing conditions. The results are presented through the framework of process maps establishing correlations among process, microstructure, and properties and providing opportunities for optimization of TBCs.

Baseliner: an open source, interactive tool for processing sap flux data from thermal dissipation probes.

Treesearch

Andrew C. Oishi; David Hawthorne; Ram Oren

2016-01-01

Estimating transpiration from woody plants using thermal dissipation sap flux sensors requires careful data processing. Currently, researchers accomplish this using spreadsheets, or by personally writing scripts for statistical software programs (e.g., R, SAS). We developed the Baseliner software to help establish a standardized protocol for processing sap...

Interactions between soil thermal and hydrological dynamics in the response of Alaska ecosystems to fire disturbance

Treesearch

Shuhua Yi; David McGuire; Jennifer Harden; Eric Kasischke; Kristen Manies; Larr Hinzman; Anna Liljedahl; Jim Randerson; Heping Liu; Vladimire Romanovsky; Sergei Marchenko; Yongwon Kim

2009-01-01

Soil temperature and moisture are important factors that control many ecosystem processes. However, interactions between soil thermal and hydrological processes are not adequately understood in cold regions, where the frozen soil, fire disturbance, and soil drainage play important roles in controlling interactions among these processes. These interactions were...

Co-processing of carbonaceous solids and petroleum oil

DOEpatents

Gupta, Avinash; Greene, Marvin I.

1992-01-01

In a process for producing distillates from coal by a first stage thermal liquefaction followed by a catalytic hydrogenation, liquefaction solvent is added at points spaced over the length of the thermal liquefaction heater. Coal may be co-processed with petroleum oil by adding pre-hydrogenated oil to the first stage or unhydrogenated oil to the second stage.

Dynamics of melt crystal interface and thermal stresses in rotational Bridgman crystal growth process

NASA Astrophysics Data System (ADS)

Ma, Ronghui; Zhang, Hui; Larson, David J.; Mandal, Krishna C.

2004-05-01

The growth process of potassium bromide (KBr) single crystals in a vertical Bridgman furnace has been studied numerically using an integrated model that combines formulation of global heat transfer and thermal elastic stresses. The global heat transfer sub-model accounts for conduction, convection and interface movement in the multiphase system. Using the elastic stress sub-model, thermal stresses in the growing crystal caused by the non-uniform temperature distribution is predicted. Special attention is directed to the interaction between the crystal and the ampoule. The global temperature distribution in the furnace, the flow pattern in the melt and the interface shapes are presented. We also investigate the effects of the natural convection and rotational forced convection on the shape of the growth fronts. Furthermore, the state of the thermal stresses in the crystal is studied to understand the plastic deformation mechanisms during the cooling process. The influence of the wall contact on thermal stresses is also addressed.

Numerical model of thermo-mechanical coupling for the tensile failure process of brittle materials

NASA Astrophysics Data System (ADS)

Fu, Yu; Wang, Zhe; Ren, Fengyu; Wang, Daguo

2017-10-01

A numerical model of thermal cracking with a thermo-mechanical coupling effect was established. The theory of tensile failure and heat conduction is used to study the tensile failure process of brittle materials, such as rock and concrete under high temperature environment. The validity of the model is verified by thick-wall cylinders with analytical solutions. The failure modes of brittle materials under thermal stresses caused by temperature gradient and different thermal expansion coefficient were studied by using a thick-wall cylinder model and an embedded particle model, respectively. In the thick-wall cylinder model, different forms of cracks induced by temperature gradient were obtained under different temperature boundary conditions. In the embedded particle model, radial cracks were produced in the medium part with lower tensile strength when temperature increased because of the different thermal expansion coefficient. Model results are in good agreement with the experimental results, thereby providing a new finite element method for analyzing the thermal damage process and mechanism of brittle materials.

Infrared thermal facial image sequence registration analysis and verification

NASA Astrophysics Data System (ADS)

Chen, Chieh-Li; Jian, Bo-Lin

2015-03-01

To study the emotional responses of subjects to the International Affective Picture System (IAPS), infrared thermal facial image sequence is preprocessed for registration before further analysis such that the variance caused by minor and irregular subject movements is reduced. Without affecting the comfort level and inducing minimal harm, this study proposes an infrared thermal facial image sequence registration process that will reduce the deviations caused by the unconscious head shaking of the subjects. A fixed image for registration is produced through the localization of the centroid of the eye region as well as image translation and rotation processes. Thermal image sequencing will then be automatically registered using the two-stage genetic algorithm proposed. The deviation before and after image registration will be demonstrated by image quality indices. The results show that the infrared thermal image sequence registration process proposed in this study is effective in localizing facial images accurately, which will be beneficial to the correlation analysis of psychological information related to the facial area.

Functionalization of nanomaterials by non-thermal large area atmospheric pressure plasmas: application to flexible dye-sensitized solar cells.

PubMed

Jung, Heesoo; Park, Jaeyoung; Yoo, Eun Sang; Han, Gill-Sang; Jung, Hyun Suk; Ko, Min Jae; Park, Sanghoo; Choe, Wonho

2013-09-07

A key challenge to the industrial application of nanotechnology is the development of fabrication processes for functional devices based on nanomaterials which can be scaled up for mass production. In this report, we disclose the results of non-thermal radio-frequency (rf) atmospheric pressure plasma (APP) based deposition of TiO2 nanoparticles on a flexible substrate for the fabrication of dye-sensitized solar cells (DSSCs). Operating at 190 °C without a vacuum enclosure, the APP method can avoid thermal damage and vacuum compatibility restrictions and utilize roll-to-roll processing over a large area. The various analyses of the TiO2 films demonstrate that superior film properties can be obtained by the non-thermal APP method when compared with the thermal sintering process operating at 450 °C. The crystallinity of the anatase TiO2 nanoparticles is significantly improved without thermal agglomeration, while the surface defects such as Ti(3+) ions are eliminated, thus providing efficient charge collecting properties for solar cells. Finally, we successfully fabricated a flexible DSSC with an energy conversion efficiency of 4.2% using a transparent plastic substrate. This work demonstrates the potential of non-thermal APP technology in the area of device-level, nano-enabled material manufacturing.

A Novel Nonelectrolytic Process for Chromium and Nickel Coating

DTIC Science & Technology

2015-06-01

thermal spraying and involves similar protocols for coating an object. The process proceeds after powder is injected into a plasma jet then superheated...HVOF) High velocity oxygen fuel coating is characteristic of a thermal spray coating process , enhancing anti-corrosion and anti-wear properties of...observations due to limited metal deposition on the surface during treatment. No powder particles were produced during this RES process . a. Optical

Fabrication of High Temperature Cermet Materials for Nuclear Thermal Propulsion

NASA Technical Reports Server (NTRS)

Hickman, Robert; Panda, Binayak; Shah, Sandeep

2005-01-01

Processing techniques are being developed to fabricate refractory metal and ceramic cermet materials for Nuclear Thermal Propulsion (NTP). Significant advances have been made in the area of high-temperature cermet fuel processing since RoverNERVA. Cermet materials offer several advantages such as retention of fission products and fuels, thermal shock resistance, hydrogen compatibility, high conductivity, and high strength. Recent NASA h d e d research has demonstrated the net shape fabrication of W-Re-HfC and other refractory metal and ceramic components that are similar to UN/W-Re cermet fuels. This effort is focused on basic research and characterization to identify the most promising compositions and processing techniques. A particular emphasis is being placed on low cost processes to fabricate near net shape parts of practical size. Several processing methods including Vacuum Plasma Spray (VPS) and conventional PM processes are being evaluated to fabricate material property samples and components. Surrogate W-Re/ZrN cermet fuel materials are being used to develop processing techniques for both coated and uncoated ceramic particles. After process optimization, depleted uranium-based cermets will be fabricated and tested to evaluate mechanical, thermal, and hot H2 erosion properties. This paper provides details on the current results of the project.

Development of a Process Signature for Manufacturing Processes with Thermal Loads

NASA Astrophysics Data System (ADS)

Frerichs, Friedhelm; Meyer, Heiner; Strunk, Rebecca; Kolkwitz, Benjamin; Epp, Jeremy

2018-06-01

The newly proposed concept of Process Signatures enables the comparison of seemingly different manufacturing processes via a process-independent approach based on the analysis of the loading condition and resulting material modification. This contribution compares the recently published results, based on numerically achieved data for the development of Process Signatures for sole surface and volume heatings without phase transformations, with the experimental data. The numerical approach applies the moving heat source theory in combination with energetic quantities. The external thermal loadings of both processes were characterized by the resulting temperature development, which correlates with a change in the residual stress state. The numerical investigations show that surface and volume heatings are interchangeable for certain parameter regimes regarding the changes in the residual stress state. Mainly, temperature gradients and thermal diffusion are responsible for the considered modifications. The applied surface- and volume-heating models are used in shallow cut grinding and induction heating, respectively. The comparison of numerical and experimental data reveals similarities, but also some systematic deviations of the residual stresses at the surface. The evaluation and final discussion support the assertion for very fast stress relaxation processes within the subsurface region. A consequence would be that the stress relaxation processes, which are not yet included in the numerical models, must be included in the Process Signatures for sole thermal impacts.

The effect of free radical inhibitor on the sensitized radiation crosslinking and thermal processing stabilization of polyurethane shape memory polymers.

PubMed

Hearon, Keith; Smith, Sarah E; Maher, Cameron A; Wilson, Thomas S; Maitland, Duncan J

2013-02-01

The effects of free radical inhibitor on the electron beam crosslinking and thermal processing stabilization of novel radiation crosslinkable polyurethane shape memory polymers (SMPs) blended with acrylic radiation sensitizers have been determined. The SMPs in this study possess novel processing capabilities-that is, the ability to be melt processed into complex geometries as thermoplastics and crosslinked in a secondary step using electron beam irradiation. To increase susceptibility to radiation crosslinking, the radiation sensitizer pentaerythritol triacrylate (PETA) was solution blended with thermoplastic polyurethane SMPs made from 2-butene-1,4-diol and trimethylhexamethylene diisocyanate (TMHDI). Because thermoplastic melt processing methods such as injection molding are often carried out at elevated temperatures, sensitizer thermal instability is a major processing concern. Free radical inhibitor can be added to provide thermal stabilization; however, inhibitor can also undesirably inhibit radiation crosslinking. In this study, we quantified both the thermal stabilization and radiation crosslinking inhibition effects of the inhibitor 1,4-benzoquinone (BQ) on polyurethane SMPs blended with PETA. Sol/gel analysis of irradiated samples showed that the inhibitor had little to no inverse effects on gel fraction at concentrations of 0-10,000 ppm, and dynamic mechanical analysis showed only a slight negative correlation between BQ composition and rubbery modulus. The 1,4-benzoquinone was also highly effective in thermally stabilizing the acrylic sensitizers. The polymer blends could be heated to 150°C for up to five hours or to 125°C for up to 24 hours if stabilized with 10,000 ppm BQ and could also be heated to 125°C for up to 5 hours if stabilized with 1000 ppm BQ without sensitizer reaction occurring. We believe this study provides significant insight into methods for manipulation of the competing mechanisms of radiation crosslinking and thermal stabilization of radiation sensitizers, thereby facilitating further development of radiation crosslinkable thermoplastic SMPs.

The effect of free radical inhibitor on the sensitized radiation crosslinking and thermal processing stabilization of polyurethane shape memory polymers

NASA Astrophysics Data System (ADS)

Hearon, Keith; Smith, Sarah E.; Maher, Cameron A.; Wilson, Thomas S.; Maitland, Duncan J.

2013-02-01

The effects of free radical inhibitor on the electron beam crosslinking and thermal processing stabilization of novel radiation crosslinkable polyurethane shape memory polymers (SMPs) blended with acrylic radiation sensitizers have been determined. The SMPs in this study possess novel processing capabilities—that is, the ability to be melt processed into complex geometries as thermoplastics and crosslinked in a secondary step using electron beam irradiation. To increase susceptibility to radiation crosslinking, the radiation sensitizer pentaerythritol triacrylate (PETA) was solution blended with thermoplastic polyurethane SMPs made from 2-butene-1,4-diol and trimethylhexamethylene diisocyanate (TMHDI). Because the thermoplastic melt processing methods such as injection molding are often carried out at elevated temperatures, sensitizer thermal instability is a major processing concern. Free radical inhibitor can be added to provide thermal stabilization; however, inhibitor can also undesirably inhibit radiation crosslinking. In this study, we quantified both the thermal stabilization and radiation crosslinking inhibition effects of the inhibitor 1,4-benzoquinone (BQ) on polyurethane SMPs blended with PETA. Sol/gel analysis of irradiated samples showed that the inhibitor had little to no inverse effects on gel fraction at concentrations of 0-10,000 ppm, and dynamic mechanical analysis showed only a slight negative correlation between BQ composition and rubbery modulus. The 1,4-benzoquinone was also highly effective in thermally stabilizing the acrylic sensitizers. The polymer blends could be heated to 150 °C for up to 5 h or to 125 °C for up to 24 h if stabilized with 10,000 ppm BQ and could also be heated to 125 °C for up to 5 h if stabilized with 1000 ppm BQ without sensitizer reaction occurring. We believe this study provides significant insight into methods for manipulation of the competing mechanisms of radiation crosslinking and thermal stabilization of radiation sensitizers, thereby facilitating further development of radiation crosslinkable thermoplastic SMPs.

Vision-aided Monitoring and Control of Thermal Spray, Spray Forming, and Welding Processes

NASA Technical Reports Server (NTRS)

Agapakis, John E.; Bolstad, Jon

1993-01-01

Vision is one of the most powerful forms of non-contact sensing for monitoring and control of manufacturing processes. However, processes involving an arc plasma or flame such as welding or thermal spraying pose particularly challenging problems to conventional vision sensing and processing techniques. The arc or plasma is not typically limited to a single spectral region and thus cannot be easily filtered out optically. This paper presents an innovative vision sensing system that uses intense stroboscopic illumination to overpower the arc light and produce a video image that is free of arc light or glare and dedicated image processing and analysis schemes that can enhance the video images or extract features of interest and produce quantitative process measures which can be used for process monitoring and control. Results of two SBIR programs sponsored by NASA and DOE and focusing on the application of this innovative vision sensing and processing technology to thermal spraying and welding process monitoring and control are discussed.

SITE TECHNOLOGY CAPSULE: CLEAN BERKSHIRES, INC. THERMAL DESORPTION SYSTEM

EPA Science Inventory

The thermal desorption process devised by Clean Berkshires, Inc., works by vaporizing the organic contaminants from the soil with heat, isolating the contaminant! in a gas stream, and then destroying them in a high efficiency afterburner. The processed solids are either replaced ...

40 CFR 240.208-1 - Requirement.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.208-1 Requirement. Residue and other solid waste products resulting from a thermal process shall be disposed of in an...

Controls for Burning Solid Wastes

ERIC Educational Resources Information Center

Toro, Richard F.; Weinstein, Norman J.

1975-01-01

Modern thermal solid waste processing systems are becoming more complex, incorporating features that require instrumentation and control systems to a degree greater than that previously required just for proper combustion control. With the advent of complex, sophisticated, thermal processing systems, TV monitoring and computer control should…

Simultaneous Determination of Thermal Conductivity and Thermal Diffusivity of Food and Agricultural Materials Using a Transient Plane-Source Method

USDA-ARS?s Scientific Manuscript database

Thermal conductivity and thermal diffusivity are two important physical properties essential for designing any food engineering processes. Recently a new transient plane-source method was developed to measure a variety of materials, but its application in foods has not been documented. Therefore, ...

Thermal pasteurization of ready-to-eat foods and vegetables: Critical factors for process design and effects on quality.

PubMed

Peng, Jing; Tang, Juming; Barrett, Diane M; Sablani, Shyam S; Anderson, Nathan; Powers, Joseph R

2017-09-22

Increasing consumer desire for high quality ready-to-eat foods makes thermal pasteurization important to both food producers and researchers. To be in compliance with the Food Safety Modernization Act (FSMA), food companies seek regulatory and scientific guidelines to ensure that their products are safe. Clearly understanding the regulations for chilled or frozen foods is of fundamental importance to the design of thermal pasteurization processes for vegetables that meet food safety requirements. This article provides an overview of the current regulations and guidelines for pasteurization in the U.S. and in Europe for control of bacterial pathogens. Poorly understood viral pathogens, in terms of their survival in thermal treatments, are an increasing concern for both food safety regulators and scientists. New data on heat resistance of viruses in different foods are summarized. Food quality attributes are sensitive to thermal degradation. A review of thermal kinetics of inactivation of quality-related enzymes in vegetables and the effects of thermal pasteurization on vegetable quality is presented. The review also discusses shelf-life of thermally pasteurized vegetables.

Characterizing Thermal Properties of Melting Te Semiconductor: Thermal Diffusivity Measurements and Simulation

NASA Technical Reports Server (NTRS)

Zhu, Shen; Li, C.; Su, Ching-Hua; Lin, B.; Ben, H.; Scripa, R. N.; Lehoczky, S. L.; Curreri, Peter A. (Technical Monitor)

2002-01-01

Tellurium is an element for many II-VI and I-III-VI(sub 2) compounds that are useful materials for fabricating many devices. In the melt growth techniques, the thermal properties of the molten phase are important parameter for controlling growth process to improve semiconducting crystal quality. In this study, thermal diffusivity of molten tellurium has been measured by a laser flash method in the temperature range from 500 C to 900 C. A pulsed laser with 1064 nm wavelength is focused on one side of the measured sample. The thermal diffusivity can be estimated from the temperature transient at the other side of the sample. A numerical simulation based on the thermal transport process has been also performed. By numerically fitting the experimental results, both the thermal conductivity and heat capacity can be derived. A relaxation phenomenon, which shows a slow drift of the measured thermal conductivity toward the equilibrium value after cooling of the sample, was observed for the first time. The error analysis and the comparison of the results to published data measured by other techniques will be discussed.

Characterizing Thermal Properties of Melting Te Semiconductor: Thermal Diffusivity Measurements and Simulation

NASA Technical Reports Server (NTRS)

Zhu, Shen; Su, Ching-Hua; Li, C.; Lin, B.; Ben, H.; Scripa, R. N.; Lehoczky, S. L.; Curreri, Peter A. (Technical Monitor)

2002-01-01

Tellurium is an element for many II-VI and I-III-VI(sub 2) compounds that are useful materials for fabricating many devises. In the melt growth techniques, the thermal properties of the molten phase are important parameter for controlling growth process to improve semiconducting crystal quality. In this study, thermal diffusivity of molten tellurium has been measured by a laser flash method in the temperature range from 500 C to 900 C. A pulsed laser with 1064 nm wavelength is focused on one side of the measured sample. The thermal diffusivity can be estimated from the temperature transient at the other side of the sample. A numerical simulation based on the thermal transport process has been also performed. By numerically fitting the experimental results, both the thermal conductivity and heat capacity can be derived. A relaxation phenomenon, which shows a slow drift of the measured thermal conductivity toward the equilibrium value after cooling of the sample, was observed for the first time. The error analysis and the comparison of the results to published data measured by other techniques will be discussed in the presentation.

High-Performance Molybdenum Coating by Wire–HVOF Thermal Spray Process

NASA Astrophysics Data System (ADS)

Tailor, Satish; Modi, Ankur; Modi, S. C.

2018-04-01

Coating deposition on many industrial components with good microstructural, mechanical properties, and better wear resistance is always a challenge for the thermal spray community. A number of thermal spray methods are used to develop such promising coatings for many industrial applications, viz. arc spray, flame spray, plasma, and HVOF. All these processes have their own limitations to achieve porous free, very dense, high-performance wear-resistant coatings. In this work, an attempt has been made to overcome this limitation. Molybdenum coatings were deposited on low-carbon steel substrates using wire-high-velocity oxy-fuel (W-HVOF; WH) thermal spray system (trade name HIJET 9610®). For a comparison, Mo coatings were also fabricated by arc spray, flame spray, plasma spray, and powder-HVOF processes. As-sprayed coatings were analyzed using x-ray diffraction, scanning electron microscopy for phase, and microstructural analysis, respectively. Coating microhardness, surface roughness, and porosity were also measured. Adhesion strength and wear tests were conducted to determine the mechanical and wear properties of the as-sprayed coatings. Results show that the coatings deposited by W-HVOF have better performance in terms of microstructural, mechanical, and wear resistance properties, in comparison with available thermal spray process (flame spray and plasma spray).

Processed milk waste recycling via thermal pretreatment and lactic acid bacteria fermentation.

PubMed

Kasmi, Mariam; Hamdi, Moktar; Trabelsi, Ismail

2017-05-01

Processed milk waste (MW) presents a serious problem within the dairy industries due to its high polluting load. Its chemical oxygen demand (COD) can reach values as high as 80,000 mg O 2  L -1 . This study proposes to reduce the organic load of those wastes using thermal coagulation and recover residual valuable components via fermentation. Thermal process results showed that the COD removal rates exceeded 40% when samples were treated at temperature above 60 °C to reach 72% at 100 °C. Clarified supernatants resulting from thermal treatment of the samples at the temperatures of 60 (MW 60 ), 80 (MW 80 ), and 100 °C (MW 100 ) were fermented using lactic acid bacteria strains without pH control. Lactic strains recorded important final cell yields (5-7 g L -1 ). Growth mediums prepared using the thermally treated MW produced 73% of the bacterial biomass recorded with a conventional culture medium. At the end of fermentation, mediums were found exhausted from several valuable components. Industrial scale implementation of the proposed process for the recycling of industrial MWs is described and discussed.

Laboratories | NREL

Science.gov Websites

| Z A Accelerated Exposure Testing Laboratory Advanced Optical Materials Laboratory Advanced Thermal Laboratory Structural Testing Laboratory Surface Analysis Laboratory Systems Performance Laboratory T Thermal Storage Materials Laboratory Thermal Storage Process and Components Laboratory Thin-Film Deposition

Thermal Conductivity of Polyimide/Carbon Nanofiller Blends

NASA Technical Reports Server (NTRS)

Delozier, D. M.; Watson, K. A.; Ghose, S.; Working, D. C.; Connell, J. W.; Smith, J. G.; Sun, Y. P.; Lin, Y.

2006-01-01

Ultem(TM) was mixed with three different carbon-based nanofillers in efforts to increase the thermal conductivity of the polymer. After initial mixing, the nanocomposites were extruded or processed via the Laboratory Mixing Molder (LMM) process. High resolution scanning electron microscopy (HRSEM) revealed significant alignment of the nanofillers in the extruded samples. Thermal conductivity measurements were made both in the direction and perpendicular to the direction of alignment of nanofillers as well as for unaligned samples. It was found that the largest improvement in thermal conductivity was achieved in the case of aligned samples when the measurement was performed in the direction of alignment. Unaligned samples also showed a significant improvement in thermal conductivity and may be useful in applications when it is not possible to align the nanofiller. However the improvements in thermal conductivity did not approach those expected based on a rule of mixtures. This is likely due to poor phonon transfer through the matrix.

Energy Efficiency of Low-Temperature Deaeration of Makeup Water for a District Heating System

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

Sharapov, V. I., E-mail: vlad-sharapov2008@yandex.ru; Kudryavtseva, E. V.

2016-07-15

It is shown that the temperature of makeup water in district heating systems has a strong effect on the energy efficiency of turbines of thermal power plants. A low-temperature deaeration process that considerably improves the energy efficiency of thermal power plants is developed. The desorbing agent is the gas supplied to the burners of the boiler. The energy efficiency of the process for a typical unit of thermal power plant is assessed.

A comparison of product yields and inorganic content in process streams following thermal hydrolysis and hydrothermal processing of microalgae, manure and digestate.

PubMed

Ekpo, U; Ross, A B; Camargo-Valero, M A; Williams, P T

2016-01-01

Thermal hydrolysis and hydrothermal processing show promise for converting biomass into higher energy density fuels. Both approaches facilitate the extraction of inorganics into the aqueous product. This study compares the behaviour of microalgae, digestate, swine and chicken manure by thermal hydrolysis and hydrothermal processing at increasing process severity. Thermal hydrolysis was performed at 170°C, hydrothermal carbonisation (HTC) was performed at 250°C, hydrothermal liquefaction (HTL) was performed at 350°C and supercritical water gasification (SCWG) was performed at 500°C. The level of nitrogen, phosphorus and potassium in the product streams was measured for each feedstock. Nitrogen is present in the aqueous phase as organic-N and NH3-N. The proportion of organic-N is higher at lower temperatures. Extraction of phosphorus is linked to the presence of inorganics such as Ca, Mg and Fe in the feedstock. Microalgae and chicken manure release phosphorus more easily than other feedstocks. Copyright © 2015. Published by Elsevier Ltd.

Immunoreactivity of Biochemically Purified Amandin from Thermally Processed Almonds (Prunus dulcis L.).

PubMed

Zaffran, Valerie D; Sathe, Shridhar K

2018-06-15

Almond seeds were subjected to select thermal processing and amandin was purified from processed and unprocessed (control) seeds using cryoprecipitation. Amandin immunoreactivity was assessed using two murine monoclonal antibodies (mAbs)-4C10 and 4F10 detecting human IgE-relevant conformational and linear epitopes, respectively. Overall amandin immunoreactivity following thermal treatment ranged from 64.9% to 277.8% (4C10) and 81.3% to 270.3% (4F10). Except for autoclaving (121 °C, 15 psi, 30 min) and roasting (160 °C, 30 min), the tested processing conditions resulted in increased immunoreactivity as determined by mAbs 4C10 and 4F10-based enzyme-linked immunosorbent assays (ELISAs). A significant, yet not complete, reduction in immunoreactivity was caused by autoclaving (121 °C, 15 psi, 30 min) and roasting (160 °C, 30 min). Western- and dot-blot immunoassays corroborated the ELISA results, confirming amandin thermal stability. The tested immunoassays indicated amandin to be stable, regardless of the targeted epitope and the processing method that whole almond seeds were subjected to. © 2018 Institute of Food Technologists®.

Integrated Modeling Activities for the James Webb Space Telescope (JWST): Structural-Thermal-Optical Analysis

NASA Technical Reports Server (NTRS)

Johnston, John D.; Parrish, Keith; Howard, Joseph M.; Mosier, Gary E.; McGinnis, Mark; Bluth, Marcel; Kim, Kevin; Ha, Hong Q.

2004-01-01

This is a continuation of a series of papers on modeling activities for JWST. The structural-thermal- optical, often referred to as "STOP", analysis process is used to predict the effect of thermal distortion on optical performance. The benchmark STOP analysis for JWST assesses the effect of an observatory slew on wavefront error. The paper begins an overview of multi-disciplinary engineering analysis, or integrated modeling, which is a critical element of the JWST mission. The STOP analysis process is then described. This process consists of the following steps: thermal analysis, structural analysis, and optical analysis. Temperatures predicted using geometric and thermal math models are mapped to the structural finite element model in order to predict thermally-induced deformations. Motions and deformations at optical surfaces are input to optical models and optical performance is predicted using either an optical ray trace or WFE estimation techniques based on prior ray traces or first order optics. Following the discussion of the analysis process, results based on models representing the design at the time of the System Requirements Review. In addition to baseline performance predictions, sensitivity studies are performed to assess modeling uncertainties. Of particular interest is the sensitivity of optical performance to uncertainties in temperature predictions and variations in metal properties. The paper concludes with a discussion of modeling uncertainty as it pertains to STOP analysis.

Nonthermal food processing alternatives and their effects on taste and flavor compounds of beverages.

PubMed

Ortega-Rivas, Enrique; Salmerón-Ochoa, Iván

2014-01-01

Food drinks are normally processed to increase their shelf-life and facilitate distribution before consumption. Thermal pasteurization is quite efficient in preventing microbial spoilage of many types of beverages, but the applied heat may also cause undesirable biochemical and nutritious changes that may affect sensory attributes of the final product. Alternative methods of pasteurization that do not include direct heat have been investigated in order to obtain products safe for consumption, but with sensory attributes maintained as unchanged as possible. Food scientists interested in nonthermal food preservation technologies have claimed that such methods of preserving foods are equally efficient in microbial inactivation as compared with conventional thermal means of food processing. Researchers in the nonthermal food preservation area also affirm that alternative preservation technologies will not affect, as much as thermal processes, nutritional and sensory attributes of processed foods. This article reviews research in nonthermal food preservation, focusing on effects of processing of food drinks such as fruit juices and dairy products. Analytical techniques used to identify volatile flavor-aroma compounds will be reviewed and comparative effects for both thermal and nonthermal preservation technologies will be discussed.

Effects of protein and phosphate buffer concentrations on thermal denaturation of lysozyme analyzed by isoconversional method

PubMed Central

Cao, X.M.; Tian, Y.; Wang, Z.Y.; Liu, Y.W.; Wang, C.X.

2016-01-01

ABSTRACT Thermal denaturation of lysozymes was studied as a function of protein concentration, phosphate buffer concentration, and scan rate using differential scanning calorimetry (DSC), which was then analyzed by the isoconversional method. The results showed that lysozyme thermal denaturation was only slightly affected by the protein concentration and scan rate. When the protein concentration and scan rate increased, the denaturation temperature (Tm) also increased accordingly. On the contrary, the Tm decreased with the increase of phosphate buffer concentration. The denaturation process of lysozymes was accelatated and the thermal stability was reduced with the increase of phosphate concentration. One part of degeneration process was not reversible where the aggregation occurred. The other part was reversible. The apparent activation energy (Ea) was computed by the isoconversional method. It decreased with the increase of the conversion ratio (α). The observed denaturation process could not be described by a simple reaction mechanism. It was not a process involving 2 standard reversible states, but a multi-step process. The new opportunities for investigating the kinetics process of protein denaturation can be supplied by this novel isoconversional method. PMID:27459596

Turbine component casting core with high resolution region

DOEpatents

Kamel, Ahmed; Merrill, Gary B.

2014-08-26

A hollow turbine engine component with complex internal features can include a first region and a second, high resolution region. The first region can be defined by a first ceramic core piece formed by any conventional process, such as by injection molding or transfer molding. The second region can be defined by a second ceramic core piece formed separately by a method effective to produce high resolution features, such as tomo lithographic molding. The first core piece and the second core piece can be joined by interlocking engagement that once subjected to an intermediate thermal heat treatment process thermally deform to form a three dimensional interlocking joint between the first and second core pieces by allowing thermal creep to irreversibly interlock the first and second core pieces together such that the joint becomes physically locked together providing joint stability through thermal processing.

Energy thresholds of discrete breathers in thermal equilibrium and relaxation processes.

PubMed

Ming, Yi; Ling, Dong-Bo; Li, Hui-Min; Ding, Ze-Jun

2017-06-01

So far, only the energy thresholds of single discrete breathers in nonlinear Hamiltonian systems have been analytically obtained. In this work, the energy thresholds of discrete breathers in thermal equilibrium and the energy thresholds of long-lived discrete breathers which can remain after a long time relaxation are analytically estimated for nonlinear chains. These energy thresholds are size dependent. The energy thresholds of discrete breathers in thermal equilibrium are the same as the previous analytical results for single discrete breathers. The energy thresholds of long-lived discrete breathers in relaxation processes are different from the previous results for single discrete breathers but agree well with the published numerical results known to us. Because real systems are either in thermal equilibrium or in relaxation processes, the obtained results could be important for experimental detection of discrete breathers.

A Technique for Transient Thermal Testing of Thick Structures

NASA Technical Reports Server (NTRS)

Horn, Thomas J.; Richards, W. Lance; Gong, Leslie

1997-01-01

A new open-loop heat flux control technique has been developed to conduct transient thermal testing of thick, thermally-conductive aerospace structures. This technique uses calibration of the radiant heater system power level as a function of heat flux, predicted aerodynamic heat flux, and the properties of an instrumented test article. An iterative process was used to generate open-loop heater power profiles prior to each transient thermal test. Differences between the measured and predicted surface temperatures were used to refine the heater power level command profiles through the iteration process. This iteration process has reduced the effects of environmental and test system design factors, which are normally compensated for by closed-loop temperature control, to acceptable levels. The final revised heater power profiles resulted in measured temperature time histories which deviated less than 25 F from the predicted surface temperatures.

Optimal cure cycle design for autoclave processing of thick composites laminates: A feasibility study

NASA Technical Reports Server (NTRS)

Hou, Jean W.

1985-01-01

The thermal analysis and the calculation of thermal sensitivity of a cure cycle in autoclave processing of thick composite laminates were studied. A finite element program for the thermal analysis and design derivatives calculation for temperature distribution and the degree of cure was developed and verified. It was found that the direct differentiation was the best approach for the thermal design sensitivity analysis. In addition, the approach of the direct differentiation provided time histories of design derivatives which are of great value to the cure cycle designers. The approach of direct differentiation is to be used for further study, i.e., the optimal cycle design.

Computer simulation of low-temperature composites sintering processes for additive technologies

NASA Astrophysics Data System (ADS)

Tovpinets, A. O.; Leytsin, V. N.; Dmitrieva, M. A.

2017-12-01

This is impact research of mixture raw components characteristics on the low-temperature composites structure formation during the sintering process. The obtained results showed that the structure determination of initial compacts obtained after thermal destruction of the polymer binder lets quantify the concentrations of main components and the refractory crystalline product of thermal destruction. Accounting for the distribution of thermal destruction refractory product allows us to refine the forecast of thermal stresses in the matrix of sintered composite. The presented results can be considered as a basis for optimization of initial compositions of multilayer low-temperature composites obtained by additive technologies.

USAF solar thermal applications overview

NASA Technical Reports Server (NTRS)

Hauger, J. S.; Simpson, J. A.

1981-01-01

Process heat applications were compared to solar thermal technologies. The generic process heat applications were analyzed for solar thermal technology utilization, using SERI's PROSYS/ECONOMAT model in an end use matching analysis and a separate analysis was made for solar ponds. Solar technologies appear attractive in a large number of applications. Low temperature applications at sites with high insolation and high fuel costs were found to be most attractive. No one solar thermal technology emerges as a clearly universal or preferred technology, however,, solar ponds offer a potential high payoff in a few, selected applications. It was shown that troughs and flat plate systems are cost effective in a large number of applications.

Development of optimum process for electron beam cross-linking of high density polyethylene thermal energy storage pellets, process scale-up and production of application qualities of material

NASA Technical Reports Server (NTRS)

Salyer, I. O.

1980-01-01

The electron irradiation conditions required to prepare thermally from stable high density polyethylene (HDPE) were defined. The conditions were defined by evaluating the heat of fusion and the melting temperature of several HDPE specimens. The performance tests conducted on the specimens, including the thermal cycling tests in the thermal energy storage unit are described. The electron beam irradiation tests performed on the specimens, in which the total radiation dose received by the pellets, the electron beam current, the accelerating potential, and the atmospheres were varied, are discussed.

Fourier transform infrared and Raman spectroscopic study of the effect of the thermal treatment and extraction methods on the characteristics of ayocote bean starches.

PubMed

Bernardino-Nicanor, Aurea; Acosta-García, Gerardo; Güemes-Vera, Norma; Montañez-Soto, José Luis; de Los Ángeles Vivar-Vera, María; González-Cruz, Leopoldo

2017-03-01

Starches isolated from four ayocote bean varieties were modified by thermal treatment to determinate the effect of the treatment on the structural changes of ayocote bean starch. Scanning electron microscopy indicates that the starch granules have oval and round shapes, with heterogeneous sizes and fractures when the extraction method is used. The presence of new bands at 2850 and 1560 cm -1 in the FT-IR spectra showed that the thermal treatment of ayocote beans induced an interaction between the protein or lipid and the amylose or amylopectin, while the sharpest band at 3400 cm -1 indicated a dehydration process in the starch granule in addition to the presence of the band at 1260 cm -1 , indicating the product of the retrogradation process. The thermal treatment reduced the crystallinity as well as short-range order. Raman spectroscopy revealed that acute changes occurred in the polysaccharide bonds after thermal treatment. This study showed that the thermal treatment affected the structural properties of ayocote bean starches, the interactions of the lipids and proteins with starch molecules and the retrogradation process of starch.

Vacuum plasma spray coating

NASA Technical Reports Server (NTRS)

Holmes, Richard R.; Mckechnie, Timothy N.

1989-01-01

Currently, protective plasma spray coatings are applied to space shuttle main engine turbine blades of high-performance nickel alloys by an air plasma spray process. Originally, a ceramic coating of yttria-stabilized zirconia (ZrO2.12Y2O3) was applied for thermal protection, but was removed because of severe spalling. In vacuum plasma spray coating, plasma coatings of nickel-chromium-aluminum-yttrium (NiCrAlY) are applied in a reduced atmosphere of argon/helium. These enhanced coatings showed no spalling after 40 MSFC burner rig thermal shock cycles between 927 C (1700 F) and -253 C (-423 F), while current coatings spalled during 5 to 25 test cycles. Subsequently, a process was developed for applying a durable thermal barrier coating of ZrO2.8Y2O3 to the turbine blades of first-stage high-pressure fuel turbopumps utilizing the enhanced NiCrAlY bond-coating process. NiCrAlY bond coating is applied first, with ZrO2.8Y2O3 added sequentially in increasing amounts until a thermal barrier coating is obtained. The enchanced thermal barrier coating has successfully passed 40 burner rig thermal shock cycles.

Model-Based Thermal System Design Optimization for the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Cataldo, Giuseppe; Niedner, Malcolm B.; Fixsen, Dale J.; Moseley, Samuel H.

2017-01-01

Spacecraft thermal model validation is normally performed by comparing model predictions with thermal test data and reducing their discrepancies to meet the mission requirements. Based on thermal engineering expertise, the model input parameters are adjusted to tune the model output response to the test data. The end result is not guaranteed to be the best solution in terms of reduced discrepancy and the process requires months to complete. A model-based methodology was developed to perform the validation process in a fully automated fashion and provide mathematical bases to the search for the optimal parameter set that minimizes the discrepancies between model and data. The methodology was successfully applied to several thermal subsystems of the James Webb Space Telescope (JWST). Global or quasiglobal optimal solutions were found and the total execution time of the model validation process was reduced to about two weeks. The model sensitivities to the parameters, which are required to solve the optimization problem, can be calculated automatically before the test begins and provide a library for sensitivity studies. This methodology represents a crucial commodity when testing complex, large-scale systems under time and budget constraints. Here, results for the JWST Core thermal system will be presented in detail.

Model-based thermal system design optimization for the James Webb Space Telescope

NASA Astrophysics Data System (ADS)

Cataldo, Giuseppe; Niedner, Malcolm B.; Fixsen, Dale J.; Moseley, Samuel H.

2017-10-01

Spacecraft thermal model validation is normally performed by comparing model predictions with thermal test data and reducing their discrepancies to meet the mission requirements. Based on thermal engineering expertise, the model input parameters are adjusted to tune the model output response to the test data. The end result is not guaranteed to be the best solution in terms of reduced discrepancy and the process requires months to complete. A model-based methodology was developed to perform the validation process in a fully automated fashion and provide mathematical bases to the search for the optimal parameter set that minimizes the discrepancies between model and data. The methodology was successfully applied to several thermal subsystems of the James Webb Space Telescope (JWST). Global or quasiglobal optimal solutions were found and the total execution time of the model validation process was reduced to about two weeks. The model sensitivities to the parameters, which are required to solve the optimization problem, can be calculated automatically before the test begins and provide a library for sensitivity studies. This methodology represents a crucial commodity when testing complex, large-scale systems under time and budget constraints. Here, results for the JWST Core thermal system will be presented in detail.

Fabrication of micro-cell UO2-Mo pellet with enhanced thermal conductivity

NASA Astrophysics Data System (ADS)

Kim, Dong-Joo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik; Oh, Jang Soo; Yang, Jae Ho; Koo, Yang-Hyun; Song, Kun-Woo

2015-07-01

As one of accident tolerant fuel pellets which should have features of good thermal conductivity and high fission product retention, a micro-cell UO2-Mo pellet has been studied in the aspect of fabrication and thermal property. It was intended to develop the compatible process with conventional UO2 pellet fabrication process. The effects of processing parameters such as the size and density of UO2 granule and the size of Mo powder have been studied to produce sound and dense pellet with completely connected uniform Mo cell-walls. The micro-cell UO2-Mo pellet consists of many Mo micro-cells and UO2 in them. The thermal conductivity of the micro-cell UO2-Mo pellet was measured and compared to those of the UO2 pellet and the UO2-Mo pellet with dispersed form of Mo particles. The thermal conductivity of the micro-cell UO2-Mo pellet was much enhanced and was found to be influenced by the Mo volumetric fraction and pellet integrity. A continuous Mo micro-cell works as a heat conducting channel in the pellet, greatly enhancing the thermal conductivity of the micro cell UO2-Mo pellet.

In situ assembly in confined spaces of coated particle scaffolds as thermal underfills with extraordinary thermal conductivity.

PubMed

Hong, Guo; Schutzius, Thomas M; Zimmermann, Severin; Burg, Brian R; Zürcher, Jonas; Brunschwiler, Thomas; Tagliabue, Giulia; Michel, Bruno; Poulikakos, Dimos

2015-01-14

In situ assembly of high thermal conductivity materials in severely confined spaces is an important problem bringing with it scientific challenges but also significant application relevance. Here we present a simple, affordable, and reproducible methodology for synthesizing such materials, composed of hierarchical diamond micro/nanoparticle scaffolds and an ethylenediamine coating. An important feature of the assembly process is the utilization of ethylenediamine as an immobilizing agent to secure the integrity of the microparticle scaffolds during and after each processing step. After other liquid components employed in the scaffolds assembly dry out, the immobilization agent solidifies forming a stable coated particle scaffold structure. Nanoparticles tend to concentrate in the shell and neck regions between adjacent microparticles. The interface between core and shell, along with the concentrated neck regions of nanoparticles, significantly enhance the thermal conductivity, making such materials an excellent candidate as thermal underfills in the electronics industry, where efficient heat removal is a major stumbling block toward increasing packing density. We show that the presented structures exhibit nearly 1 order of magnitude improvement in thermal conductivity, enhanced temperature uniformity, and reduced processing time compared to commercially available products for electronics cooling, which underpins their potential utility.

Thermo-acousto-photonics for noncontact temperature measurement in silicon wafer processing

NASA Astrophysics Data System (ADS)

Suh, Chii-Der S.; Rabroker, G. Andrew; Chona, Ravinder; Burger, Christian P.

1999-10-01

A non-contact thermometry technique has been developed to characterize the thermal state of silicon wafers during rapid thermal processing. Information on thermal variations is obtained from the dispersion relations of the propagating waveguide mode excited in wafers using a non-contact, broadband optical system referred to as Thermal Acousto- Photonics for Non-Destructive Evaluation. Variations of thermo-mechanical properties in silicon wafers are correlated to temperature changes by performing simultaneous time-frequency analyses on Lamb waveforms acquired with a fiber-tip interferometer sensor. Experimental Lamb wave data collected for cases ranging from room temperature to 400 degrees C is presented. The results show that the temporal progressions of all spectral elements found in the fundamental antisymmetric mode are strong functions of temperature. This particular attribute is exploited to achieve a thermal resolution superior to the +/- 5 degrees C attainable through current pyrometric techniques. By analyzing the temperature-dependent group velocity of a specific frequency component over the temperature range considered and then comparing the results to an analytical model developed for silicon wafers undergoing annealing, excellent agreement was obtained. Presented results demonstrate the feasibility of applying laser-induced stress waves as a temperature diagnostic during rapid thermal processing.

New portable instrument for the measurement of thermal conductivity in gas process conditions

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

Queirós, C. S. G. P.; Lourenço, M. J. V., E-mail: mjlourenco@fc.ul.pt; Vieira, S. I.

The development of high temperature gas sensors for the monitoring and determination of thermophysical properties of complex process mixtures at high temperatures faces several problems, related with the materials compatibility, active sensing parts sensitivity, and lifetime. Ceramic/thin metal films based sensors, previously developed for the determination of thermal conductivity of molten materials up to 1200 °C, were redesigned, constructed, and applied for thermal conductivity measuring sensors. Platinum resistance thermometers were also developed using the same technology, to be used in the temperature measurement, which were also constructed and tested. A new data acquisition system for the thermal conductivity sensors, based onmore » a linearization of the transient hot-strip model, including a portable electronic bridge for the measurement of the thermal conductivity in gas process conditions was also developed. The equipment is capable of measuring the thermal conductivity of gaseous phases with an accuracy of 2%-5% up to 840 °C (95% confidence level). The development of sensors up to 1200 °C, present at the core of the combustion chambers, will be done in a near future.« less

REBURNING THERMAL AND CHEMICAL PROCESSES IN A TWO-DIMENSIONAL PILOT-SCALE SYSTEM

EPA Science Inventory

The paper describes an experimental investigation of the thermal and chemical processes influencing NOx reduction by natural gas reburning in a two-dimensional pilot-scale combustion system. Reburning effectiveness for initial NOx levels of 50-500 ppm and reburn stoichiometric ra...

9 CFR 381.302 - Thermal processing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Canning and Canned Products § 381.302... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Thermal processing. 381.302 Section 381.302 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

9 CFR 318.302 - Thermal processing.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Thermal processing. 318.302 Section 318.302 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... retort come-up operating procedures and critical factors. (2) Letters or other written communications...

Sludge thermal oxidation processes: mineral recycling, energy impact, and greenhouse effect gases release.

PubMed

Guibelin, E

2004-01-01

Different treatment routes have been studied for a mixed sludge: the conventional agricultural use is compared with the thermal oxidation processes, including incineration (in gaseous phase) and wet air oxidation (in liquid phase). The interest of a sludge digestion prior to the final treatment has been also considered according to the two major criteria, which are the fossil energy utilisation and the greenhouse effect gases (CO2, CH4, N2O) release. Thermal energy has to be recovered on thermal processes to make these processes environmentally friendly, otherwise their main interest is to extract or destroy micropollutants and pathogens from the carbon cycle. In case of continuous energy recovery, incineration can produce more energy than it consumes. Digestion is especially interesting for agriculture: according to these two schemes, the energy final balance can also be in excess. As to wet air oxidation, it is probably one of the best ways to minimize greenhouse effect gases emission.

Investigation of solid organic waste processing by oxidative pyrolysis

NASA Astrophysics Data System (ADS)

Kolibaba, O. B.; Sokolsky, A. I.; Gabitov, R. N.

2017-11-01

A thermal analysis of a mixture of municipal solid waste (MSW) of the average morphological composition and its individual components was carried out in order to develop ways to improve the efficiency of its utilization for energy production in thermal reactors. Experimental studies were performed on a synchronous thermal analyzer NETZSCH STA 449 F3 Jupiter combined with a quadrupole mass spectrometer QMC 403. Based on the results of the experiments, the temperature ranges of the pyrolysis process were determined as well as the rate of decrease of the mass of the sample of solid waste during the drying and oxidative pyrolysis processes, the thermal effects accompanying these processes, as well as the composition and volumes of gases produced during oxidative pyrolysis of solid waste and its components in an atmosphere with oxygen content of 1%, 5%, and 10%. On the basis of experimental data the dependences of the yield of gas on the moisture content of MSW were obtained under different pyrolysis conditions under which a gas of various calorific values was produced.

Guidelines for the Selection of Near-Earth Thermal Environment Parameters for Spacecraft Design

NASA Technical Reports Server (NTRS)

Anderson, B. J.; Justus, C. G.; Batts, G. W.

2001-01-01

Thermal analysis and design of Earth orbiting systems requires specification of three environmental thermal parameters: the direct solar irradiance, Earth's local albedo, and outgoing longwave radiance (OLR). In the early 1990s data sets from the Earth Radiation Budget Experiment were analyzed on behalf of the Space Station Program to provide an accurate description of these parameters as a function of averaging time along the orbital path. This information, documented in SSP 30425 and, in more generic form in NASA/TM-4527, enabled the specification of the proper thermal parameters for systems of various thermal response time constants. However, working with the engineering community and SSP-30425 and TM-4527 products over a number of years revealed difficulties in interpretation and application of this material. For this reason it was decided to develop this guidelines document to help resolve these issues of practical application. In the process, the data were extensively reprocessed and a new computer code, the Simple Thermal Environment Model (STEM) was developed to simplify the process of selecting the parameters for input into extreme hot and cold thermal analyses and design specifications. In the process, greatly improved values for the cold case OLR values for high inclination orbits were derived. Thermal parameters for satellites in low, medium, and high inclination low-Earth orbit and with various system thermal time constraints are recommended for analysis of extreme hot and cold conditions. Practical information as to the interpretation and application of the information and an introduction to the STEM are included. Complete documentation for STEM is found in the user's manual, in preparation.

Hydrological response and thermal effect of karst springs linked to aquifer geometry and recharge processes

NASA Astrophysics Data System (ADS)

Luo, Mingming; Chen, Zhihua; Zhou, Hong; Zhang, Liang; Han, Zhaofeng

2018-03-01

To be better understand the hydrological and thermal behavior of karst systems in South China, seasonal variations in flow, hydrochemistry and stable isotope ratios of five karst springs were used to delineate flow paths and recharge processes, and to interpret their thermal response. Isotopic data suggest that mean recharge elevations are 200-820 m above spring outlets. Springs that originate from high elevations have lower NO3 - concentrations than those originating from lower areas that have more agricultural activity. Measured Sr2+ concentrations reflect the strontium contents of the host carbonate aquifer and help delineate the spring catchment's saturated zone. Seasonal variations of NO3 - and Sr2+ concentrations are inversely correlated, because the former correlates with event water and the latter with baseflow. The mean annual water temperatures of springs were only slightly lower than the local mean annual surface temperature at the outlet elevations. These mean spring temperatures suggest a vertical gradient of 6 °C/vertical km, which resembles the adiabatic lapse rate of the Earth's stable atmosphere. Seasonal temperature variations in the springs are in phase with surface air temperatures, except for Heilongquan (HLQ) spring. Event-scale variations of thermal response are dramatically controlled by the circulation depth of karst systems, which determines the effectiveness of heat exchange. HLQ spring undergoes the deepest circulation depth of 820 m, and its thermal responses are determined by the thermally effective regulation processes at higher elevations and the mixing processes associated with thermally ineffective responses at lower elevations.

Plasma Spray-PVD: A New Thermal Spray Process to Deposit Out of the Vapor Phase

NASA Astrophysics Data System (ADS)

von Niessen, Konstantin; Gindrat, Malko

2011-06-01

Plasma spray-physical vapor deposition (PS-PVD) is a low pressure plasma spray technology recently developed by Sulzer Metco AG (Switzerland). Even though it is a thermal spray process, it can deposit coatings out of the vapor phase. The basis of PS-PVD is the low pressure plasma spraying (LPPS) technology that has been well established in industry for several years. In comparison to conventional vacuum plasma spraying (VPS) or low pressure plasma spraying (LPPS), the new proposed process uses a high energy plasma gun operated at a reduced work pressure of 0.1 kPa (1 mbar). Owing to the high energy plasma and further reduced work pressure, PS-PVD is able to deposit a coating not only by melting the feed stock material which builds up a layer from liquid splats but also by vaporizing the injected material. Therefore, the PS-PVD process fills the gap between the conventional physical vapor deposition (PVD) technologies and standard thermal spray processes. The possibility to vaporize feedstock material and to produce layers out of the vapor phase results in new and unique coating microstructures. The properties of such coatings are superior to those of thermal spray and electron beam-physical vapor deposition (EB-PVD) coatings. In contrast to EB-PVD, PS-PVD incorporates the vaporized coating material into a supersonic plasma plume. Owing to the forced gas stream of the plasma jet, complex shaped parts such as multi-airfoil turbine vanes can be coated with columnar thermal barrier coatings using PS-PVD. Even shadowed areas and areas which are not in the line of sight of the coating source can be coated homogeneously. This article reports on the progress made by Sulzer Metco in developing a thermal spray process to produce coatings out of the vapor phase. Columnar thermal barrier coatings made of Yttria-stabilized Zircona (YSZ) are optimized to serve in a turbine engine. This process includes not only preferable coating properties such as strain tolerance and erosion resistance but also the simultaneous coverage of multiple air foils.

Thermal acidization and recovery process for recovering viscous petroleum

DOEpatents

Poston, Robert S.

1984-01-01

A thermal acidization and recovery process for increasing production of heavy viscous petroleum crude oil and synthetic fuels from subterranean hydrocarbon formations containing clay particles creating adverse permeability effects is described. The method comprises injecting a thermal vapor stream through a well bore penetrating such formations to clean the formation face of hydrocarbonaceous materials which restrict the flow of fluids into the petroleum-bearing formation. Vaporized hydrogen chloride is then injected simultaneously to react with calcium and magnesium salts in the formation surrounding the bore hole to form water soluble chloride salts. Vaporized hydrogen fluoride is then injected simultaneously with its thermal vapor to dissolve water-sensitive clay particles thus increasing permeability. Thereafter, the thermal vapors are injected until the formation is sufficiently heated to permit increased recovery rates of the petroleum.

Influences of thermal environment on fish growth.

PubMed

Boltaña, Sebastián; Sanhueza, Nataly; Aguilar, Andrea; Gallardo-Escarate, Cristian; Arriagada, Gabriel; Valdes, Juan Antonio; Soto, Doris; Quiñones, Renato A

2017-09-01

Thermoregulation in ectothermic animals is influenced by the ability to effectively respond to thermal variations. While it is known that ectotherms are affected by thermal changes, it remains unknown whether physiological and/or metabolic traits are impacted by modifications to the thermal environment. Our research provides key evidence that fish ectotherms are highly influenced by thermal variability during development, which leads to important modifications at several metabolic levels (e.g., growth trajectories, microstructural alterations, muscle injuries, and molecular mechanisms). In Atlantic salmon ( Salmo salar ), a wide thermal range (Δ T 6.4°C) during development (posthatch larvae to juveniles) was associated with increases in key thermal performance measures for survival and growth trajectory. Other metabolic traits were also significantly influenced, such as size, muscle cellularity, and molecular growth regulators possibly affected by adaptive processes. In contrast, a restricted thermal range (Δ T 1.4°C) was detrimental to growth, survival, and cellular microstructure as muscle growth could not keep pace with increased metabolic demands. These findings provide a possible basic explanation for the effects of thermal environment during growth. In conclusion, our results highlight the key role of thermal range amplitude on survival and on interactions with major metabolism-regulating processes that have positive adaptive effects for organisms.

APPLICATION OF THERMAL DESORPTION TECHNOLOGIES TO HAZARDOUS WASTE SITES

EPA Science Inventory

Thermal desorption is a separation process frequently used to remediate many Superfund sites. Thermal desorption technologies are recommended and used because of (1) the wide range of organic contaminants effectively treated, (2) availability and mobility of commercial systems, ...

Continued field evaluation of precutting for maintaining asphalt concrete pavements with thermal cracking.

DOT National Transportation Integrated Search

2017-08-01

In continuation of a previously completed project entitled Evaluate Presawn Transverse Thermal Cracks for Asphalt Concrete Pavement, this project was a further effort to understand important variables in the thermal cracking process through continued...

Bacteria, mould and yeast spore inactivation studies by scanning electron microscope observations.

PubMed

Rozali, Siti N M; Milani, Elham A; Deed, Rebecca C; Silva, Filipa V M

2017-12-18

Spores are the most resistant form of microbial cells, thus difficult to inactivate. The pathogenic or food spoilage effects of certain spore-forming microorganisms have been the primary basis of sterilization and pasteurization processes. Thermal sterilization is the most common method to inactivate spores present on medical equipment and foods. High pressure processing (HPP) is an emerging and commercial non-thermal food pasteurization technique. Although previous studies demonstrated the effectiveness of thermal and non-thermal spore inactivation, the in-depth mechanisms of spore inactivation are as yet unclear. Live and dead forms of two food spoilage bacteria, a mould and a yeast were examined using scanning electron microscopy before and after the inactivation treatment. Alicyclobacillus acidoterrestris and Geobacillus stearothermophilus bacteria are indicators of acidic foods pasteurization and sterilization processes, respectively. Neosartorya fischeri is a phyto-pathogenic mould attacking fruits. Saccharomyces cerevisiae is a yeast with various applications for winemaking, brewing, baking and the production of biofuel from crops (e.g. sugar cane). Spores of the four microbial species were thermally inactivated. Spores of S. cerevisiae were observed in the ascus and free form after thermal and HPP treatments. Different forms of damage and cell destruction were observed for each microbial spore. Thermal treatment inactivated bacterial spores of A. acidoterrestris and G. stearothermophilus by attacking the inner core of the spore. The heat first altered the membrane permeability allowing the release of intracellular components. Subsequently, hydration of spores, physicochemical modifications of proteins, flattening and formation of indentations occurred, with subsequent spore death. Regarding N. fischeri, thermal inactivation caused cell destruction and leakage of intracellular components. Both thermal and HPP treatments of S. cerevisiae free spores attacked the inner membrane, altering its permeability, and allowing in final stages the transfer of intracellular components to the outside. The spore destruction caused by thermal treatment was more severe than HPP, as HPP had less effect on the spore core. All injured spores have undergone irreversible volume and shape changes. While some of the leakage of spore contents is visible around the deformed but fully shaped spore, other spores exhibited large indentations and were completely deformed, apparently without any contents inside. This current study contributed to the understanding of spore inactivation by thermal and non-thermal processes. Copyright © 2017 Elsevier B.V. All rights reserved.

Thermal Expansion of Polyurethane Foam

NASA Technical Reports Server (NTRS)

Lerch, Bradley A.; Sullivan, Roy M.

2006-01-01

Closed cell foams are often used for thermal insulation. In the case of the Space Shuttle, the External Tank uses several thermal protection systems to maintain the temperature of the cryogenic fuels. A few of these systems are polyurethane, closed cell foams. In an attempt to better understand the foam behavior on the tank, we are in the process of developing and improving thermal-mechanical models for the foams. These models will start at the microstructural level and progress to the overall structural behavior of the foams on the tank. One of the key properties for model characterization and verification is thermal expansion. Since the foam is not a material, but a structure, the modeling of the expansion is complex. It is also exacerbated by the anisoptropy of the material. During the spraying and foaming process, the cells become elongated in the rise direction and this imparts different properties in the rise direction than in the transverse directions. Our approach is to treat the foam as a two part structure consisting of the polymeric cell structure and the gas inside the cells. The polymeric skeleton has a thermal expansion of its own which is derived from the basic polymer chemistry. However, a major contributor to the thermal expansion is the volume change associated with the gas inside of the closed cells. As this gas expands it exerts pressure on the cell walls and changes the shape and size of the cells. The amount that this occurs depends on the elastic and viscoplastic properties of the polymer skeleton. The more compliant the polymeric skeleton, the more influence the gas pressure has on the expansion. An additional influence on the expansion process is that the polymeric skeleton begins to breakdown at elevated temperatures and releases additional gas species into the cell interiors, adding to the gas pressure. The fact that this is such a complex process makes thermal expansion ideal for testing the models. This report focuses on the thermal expansion tests and the response of the microstructure. A novel optical method is described which is appropriate for measuring thermal expansion at high temperatures without influencing the thermal expansion measurement. Detailed microstructural investigations will also be described which show cell expansion as a function of temperature. Finally, a phenomenological model on thermal expansion will be described.

Thermal Processing of PVP- and HPMC-Based Amorphous Solid Dispersions.

PubMed

LaFountaine, Justin S; Prasad, Leena Kumari; Brough, Chris; Miller, Dave A; McGinity, James W; Williams, Robert O

2016-02-01

Thermal processing technologies continue to gain interest in pharmaceutical manufacturing. However, the types and grades of polymers that can be utilized in common thermal processing technologies, such as hot-melt extrusion (HME), are often limited by thermal or rheological factors. The objectives of the present study were to compare and contrast two thermal processing methods, HME and KinetiSol® Dispersing (KSD), and investigate the influence of polymer type, polymer molecular weight, and drug loading on the ability to produce amorphous solid dispersions (ASDs) containing the model compound griseofulvin (GRIS). Dispersions were analyzed by a variety of imaging, solid-state, thermal, and solution-state techniques. Dispersions were prepared by both HME and KSD using polyvinylpyrrolidone (PVP) K17 or hydroxypropyl methylcellulose (HPMC) E5. Dispersions were only prepared by KSD using higher molecular weight grades of HPMC and PVP, as these could not be extruded under the conditions selected. Powder X-ray diffraction (PXRD) analysis showed that dispersions prepared by HME were amorphous at 10% and 20% drug load; however, it showed significant crystallinity at 40% drug load. PXRD analysis of KSD samples showed all formulations and drug loads to be amorphous with the exception of trace crystallinity seen in PVP K17 and PVP K30 samples at 40% drug load. These results were further supported by other analytical techniques. KSD produced amorphous dispersions at higher drug loads than could be prepared by HME, as well as with higher molecular weight polymers that were not processable by HME, due to its higher rate of shear and torque output.

Modeling of thermalization phenomena in coaxial plasma accelerators

NASA Astrophysics Data System (ADS)

Subramaniam, Vivek; Panneerchelvam, Premkumar; Raja, Laxminarayan L.

2018-05-01

Coaxial plasma accelerators are electromagnetic acceleration devices that employ a self-induced Lorentz force to produce collimated plasma jets with velocities ~50 km s‑1. The accelerator operation is characterized by the formation of an ionization/thermalization zone near gas inlet of the device that continually processes the incoming neutral gas into a highly ionized thermal plasma. In this paper, we present a 1D non-equilibrium plasma model to resolve the plasma formation and the electron-heavy species thermalization phenomena that take place in the thermalization zone. The non-equilibrium model is based on a self-consistent multi-species continuum description of the plasma with finite-rate chemistry. The thermalization zone is modelled by tracking a 1D gas-bit as it convects down the device with an initial gas pressure of 1 atm. The thermalization process occurs in two stages. The first is a plasma production stage, associated with a rapid increase in the charged species number densities facilitated by cathode surface electron emission and volumetric production processes. The production stage results in the formation of a two-temperature plasma with electron energies of ~2.5 eV in a low temperature background gas of ~300 K. The second, a temperature equilibration stage, is characterized by the energy transfer between the electrons and heavy species. The characteristic length scale for thermalization is found to be comparable to axial length of the accelerator thus putting into question the equilibrium magnetohydrodynamics assumption used in modeling coaxial accelerators.

Process to improve boiler operation by supplemental firing with thermally beneficiated low rank coal

DOEpatents

Sheldon, Ray W.

2001-01-01

The invention described is a process for improving the performance of a commercial coal or lignite fired boiler system by supplementing its normal coal supply with a controlled quantity of thermally beneficiated low rank coal, (TBLRC). This supplemental TBLRC can be delivered either to the solid fuel mill (pulverizer) or directly to the coal burner feed pipe. Specific benefits are supplied based on knowledge of equipment types that may be employed on a commercial scale to complete the process. The thermally beneficiated low rank coal can be delivered along with regular coal or intermittently with regular coal as the needs require.

The influence of flash lamp annealing on the minority carrier lifetime of Czochralski silicon wafers

NASA Astrophysics Data System (ADS)

Kissinger, G.; Kot, D.; Sattler, A.

2014-02-01

Flash lamp annealing of moderately B-doped CZ silicon wafers for 20 ms with a normalized irradiance of about 0.9 was used to efficiently suppress oxygen precipitation during subsequent thermal processing. In this way, the minority carrier lifetime measured at high injection level by microwave-detected photo-conductance decay (μ-PCD) was increased from about 30 microseconds to about 300 microseconds after a thermal process consisting of 780 °C 3 h + 1000 °C 16 h. The grown-in oxide precipitate nuclei were shrunken to a subcritical size during the flash lamp anneal which prevents further growth during subsequent thermal processing.

Continuous fiber-reinforced titanium aluminide composites

NASA Technical Reports Server (NTRS)

Mackay, R. A.; Brindley, P. K.; Froes, F. H.

1991-01-01

An account is given of the fabrication techniques, microstructural characteristics, and mechanical behavior of a lightweight, high service temperature SiC-reinforced alpha-2 Ti-14Al-21Nb intermetallic-matrix composite. Fabrication techniques under investigation to improve the low-temperature ductility and environmental resistance of this material system, while reducing manufacturing costs to competitive levels, encompass powder-cloth processing, foil-fiber-foil processing, and thermal-spray processing. Attention is given to composite microstructure problems associated with fiber distribution and fiber-matrix interfaces, as well as with mismatches of thermal-expansion coefficient; major improvements are noted to be required in tensile properties, thermal cycling effects, mechanical damage, creep, and environmental effects.

Effect of thermal implying during ageing process of nanorods growth on the properties of zinc oxide nanorod arrays

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

Ismail, A. S., E-mail: kyrin-samaxi@yahoo.com; Mamat, M. H., E-mail: mhmamat@salam.uitm.edu.my; Rusop, M., E-mail: rusop@salam.uitm.my

Undoped and Sn-doped Zinc oxide (ZnO) nanostructures have been fabricated using a simple sol-gel immersion method at 95°C of growth temperature. Thermal sourced by hot plate stirrer was supplied to the solution during ageing process of nanorods growth. The results showed significant decrement in the quality of layer produced after the immersion process where the conductivity and porosity of the samples reduced significantly due to the thermal appliance. The structural properties of the samples have been characterized using field emission scanning electron microscopy (FESEM) electrical properties has been characterized using current voltage (I-V) measurement.

STEP wastewater treatment: a solar thermal electrochemical process for pollutant oxidation.

PubMed

Wang, Baohui; Wu, Hongjun; Zhang, Guoxue; Licht, Stuart

2012-10-01

A solar thermal electrochemical production (STEP) pathway was established to utilize solar energy to drive useful chemical processes. In this paper, we use experimental chemistry for efficient STEP wastewater treatment, and suggest a theory based on the decreasing stability of organic pollutants (hydrocarbon oxidation potentials) with increasing temperature. Exemplified by the solar thermal electrochemical oxidation of phenol, the fundamental model and experimental system components of this process outline a general method for the oxidation of environmentally stable organic pollutants into carbon dioxide, which is easily removed. Using thermodynamic calculations we show a sharply decreasing phenol oxidation potential with increasing temperature. The experimental results demonstrate that this increased temperature can be supplied by solar thermal heating. In combination this drives electrochemical phenol removal with enhanced oxidation efficiency through (i) a thermodynamically driven decrease in the energy needed to fuel the process and (ii) improved kinetics to sustain high rates of phenol oxidation at low electrochemical overpotential. The STEP wastewater treatment process is synergistic in that it is performed with higher efficiency than either electrochemical or photovoltaic conversion process acting alone. STEP is a green, efficient, safe, and sustainable process for organic wastewater treatment driven solely by solar energy. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

9 CFR 318.304 - Operations in the thermal processing area.

Code of Federal Regulations, 2010 CFR

2010-01-01

... area. 318.304 Section 318.304 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION... PREPARATION OF PRODUCTS Canning and Canned Products § 318.304 Operations in the thermal processing area. (a...

DSLM Instructional Approach to Conceptual Change Involving Thermal Expansion.

ERIC Educational Resources Information Center

She, Hsiao-Ching

2003-01-01

Examines the process of student conceptual change regarding thermal expansion using the Dual Situated Learning Model (DSLM) as an instructional approach. Indicates that DSLM promotes conceptual change and holds great potential to facilitate the process through classroom instruction at all levels. (Contains 38 references.) (Author/NB)

Heat and pressure treatments effects on peanut allergenicity

USDA-ARS?s Scientific Manuscript database

Peanut allergy is recognized as one of the most severe food allergies. The aim of this study was to investigate the changes in IgE binding capacity of peanut proteins produced by thermal-processing methods, including autoclaving. Immunoreactivity to raw and thermally processed peanut extracts was ev...

9 CFR 381.304 - Operations in the thermal processing area.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Canning and Canned... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Operations in the thermal processing area. 381.304 Section 381.304 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE...

Phase transitions and structural formation of PEG-PCL-PEG copolymer in the processes of fused deposition 3D printing

NASA Astrophysics Data System (ADS)

Dunaev, A.; Mariyanac, A.; Mironov, A.; Mironova, O.; Popov, V.; Syachina, M.

2018-04-01

In present work the analysis of thermal field distribution and thermal analysis were used to study phase and structural transformations in the block copolymer of polycaprolactone and polyethylene glycol in the process of scaffolds fabrication for tissue engineering using fused deposition modeling. It was shown that the intact polymer has a noticeable thermal history and formed degree of crystallinity which is close to its equilibrium value, while the microstructure of the polymer stays unchanged.

Thermal Studies of Ammonium Cyanide Reactions: A Model for Thermal Alteration of Prebiotic Compounds in Meteorite Parent Bodies

NASA Technical Reports Server (NTRS)

Hammer, P. G.; Locke, D. R.; Burton, A. S.; Callahan, M. P.

2017-01-01

Organic compounds in carbonaceous chondrites were likely transformed by a variety of parent body processes including thermal and aqueous processing. Here, we analyzed ammonium cyanide reactions that were heated at different temperatures and times by multiple analytical techniques. The goal of this study is to better understand the effect of hydrothermal alteration on cyanide chemistry, which is believed to be responsible for the abiotic synthesis of purine nucleobases and their structural analogs detected in carbonaceous chondrites.

Radiation-Thermal Sintering of Zirconia Powder Compacts Under Conditions of Bilateral Heating Using Beams of Low-Energy Electrons

NASA Astrophysics Data System (ADS)

Ghyngazov, S. A.; Frangulyan, T. S.; Chernyavskii, A. V.; Goreev, A. K.; Naiden, E. P.

2015-06-01

Comparative experiments on sintering zirconia ceramics are performed using colliding beams of low-energy electrons and under conditions of thermal heating. The density and microhardness of ceramic materials manufactured via different processes are determined. The use of a regime of bilateral heating by high-intensity,low-energy electron beams is shown to intensify the sintering process and yield material specimens with improved characteristics compared to those formed by thermal sintering.

Processing thermally labile drugs by hot-melt extrusion: The lesson with gliclazide.

PubMed

Huang, Siyuan; O'Donnell, Kevin P; Delpon de Vaux, Sophie M; O'Brien, John; Stutzman, John; Williams, Robert O

2017-10-01

The formation of molecularly dispersed amorphous solid dispersions by the hot-melt extrusion technique relies on the thermal and mechanical energy inputs, which can cause chemical degradation of drugs and polymeric carriers. Additionally, drug degradation may be exacerbated as drugs convert from a more stable crystalline form to a higher energy amorphous form. Therefore, it is imperative to study how drug degrades and evaluate methods to minimize drug degradation during the extrusion process. In this work, gliclazide was used as a model thermally labile drug for the degradation kinetics and process optimization studies. Preformulation studies were conducted using thermal analyses, and liquid chromatography-mass spectroscopy to identify drug degradation pathways and to determine initial extrusion conditions. Formulations containing 10% drug and 90% AFFINISOL™ HPMC HME 100LV were then extruded using a twin screw extruder, and the extrudates were characterized using X-ray powder diffraction, modulated dynamic scanning calorimetry, and potency testing to evaluate physicochemical properties. The energies of activation for both amorphous gliclazide, crystalline gliclazide, and gliclazide solution were calculated using the Arrhenius equation to further guide the extrusion optimization process. Preformulation studies identify two hydrolysis degradation pathways of gliclazide at elevated temperatures. The activation energy study indicates a significantly higher degradation rate for the amorphous gliclazide compared to the crystalline form. After optimization of the hot-melt extrusion process, including improved screw designs, machine setup, and processing conditions, gliclazide amorphous solid dispersion with ∼95% drug recovery was achieved. The ability to process thermally labile drugs and polymers using hot-melt extrusion will significantly expand the possible applications of this manufacturing process. Copyright © 2017 Elsevier B.V. All rights reserved.

Low thermal budget annealing technique for high performance amorphous In-Ga-ZnO thin film transistors

NASA Astrophysics Data System (ADS)

Shin, Joong-Won; Cho, Won-Ju

2017-07-01

In this paper, we investigate a low thermal budget post-deposition-annealing (PDA) process for amorphous In-Ga-ZnO (a-IGZO) oxide semiconductor thin-film-transistors (TFTs). To evaluate the electrical characteristics and reliability of the TFTs after the PDA process, microwave annealing (MWA) and rapid thermal annealing (RTA) methods were applied, and the results were compared with those of the conventional annealing (CTA) method. The a-IGZO TFTs fabricated with as-deposited films exhibited poor electrical characteristics; however, their characteristics were improved by the proposed PDA process. The CTA-treated TFTs had excellent electrical properties and stability, but the CTA method required high temperatures and long processing times. In contrast, the fabricated RTA-treated TFTs benefited from the lower thermal budget due to the short process time; however, they exhibited poor stability. The MWA method uses a low temperature (100 °C) and short annealing time (2 min) because microwaves transfer energy directly to the substrate, and this method effectively removed the defects in the a-IGZO TFTs. Consequently, they had a higher mobility, higher on-off current ratio, lower hysteresis voltage, lower subthreshold swing, and higher interface trap density than TFTs treated with CTA or RTA, and exhibited excellent stability. Based on these results, low thermal budget MWA is a promising technology for use on various substrates in next generation displays.

Osteoconductivity and Hydrophilicity of TiO2 Coatings on Ti Substrates Prepared by Different Oxidizing Processes

PubMed Central

Yamamoto, Dai; Kawai, Ikki; Kuroda, Kensuke; Ichino, Ryoichi; Okido, Masazumi; Seki, Azusa

2012-01-01

Various techniques for forming TiO2 coatings on Ti have been investigated for the improvement of the osteoconductivity of Ti implants. However, it is not clear how the oxidizing process affects this osteoconductivity. In this study, TiO2 coatings were prepared using the following three processes: anodizing in 0.1 M H3PO4 or 0.1 M NaOH aqueous solution; thermal oxidation at 673 K for 2 h in air; and a two-step process of anodizing followed by thermal oxidation. The oxide coatings were evaluated using SEM, XRD, and XPS. The water contact angle on the TiO2 coatings was measured as a surface property. The osteoconductivity of these samples was evaluated by measuring the contact ratio of formed hard tissue on the implanted samples (defined as the R B-I value) after 14 d implantation in rats' tibias. Anatase was formed by anodizing and rutile by thermal oxidation, but the difference in the TiO2 crystal structure did not influence the osteoconductivity. Anodized TiO2 coatings were hydrophilic, but thermally oxidized TiO2 coatings were less hydrophilic than anodized TiO2 coatings because they lacked in surface OH groups. The TiO2 coating process using anodizing without thermal oxidation gave effective improvement of the osteoconductivity of Ti samples. PMID:23316128

Integration of process diagnostics and three dimensional simulations in thermal spraying

NASA Astrophysics Data System (ADS)

Zhang, Wei

Thermal spraying is a group of processes in which the metallic or ceramic materials are deposited in a molten or semi-molten state on a prepared substrate. In atmospheric plasma spray process, a thermal plasma jet is used to heat up and accelerate loading particles. The process is inherently complex due to the deviation from equilibrium conditions, three dimensional nature, multitude of interrelated variables involved, and stochastic variability at different stages. This dissertation is aimed at understanding the in-flight particle state and plasma plume characteristics in atmospheric plasma spray process through the integration of process diagnostics and three-dimensional simulation. Effects of injection angle and carrier gas flow rate on in-flight particle characteristics are studied experimentally and interpreted through numerical simulation. Plasma jet perturbation by particle injection angle, carrier gas, and particle loading are also identified. Maximum particle average temperature and velocity at any given spray distance is systematically quantified. Optimum plasma plume position for particle injection which was observed in experiments was verified numerically along with description of physical mechanisms. Correlation of spray distance with in-flight particle behavior for various kinds of materials is revealed. A new strategy for visualization and representation of particle diagnostic results for thermal spray processes has been presented. Specifically, 1 st order process maps (process-particle interactions) have been addressed by converting the Temperature-Velocity of particles obtained via diagnostics into non-dimensional group parameters [Melting Index-Reynolds number]. This approach provides an improved description of the thermal and kinetic energy of particles and allows for cross-comparison of diagnostic data within a given process for different materials, comparison of a single material across different thermal spray processes, and detailed assessment of the melting behavior through recourse to analysis of the distributions. An additional group parameter, Oxidation Index, has been applied to relatively track the oxidation extent of metallic particles under different operating conditions. The new mapping strategies have also been proposed in circumstances where only ensemble particle diagnostics are available. Through the integration of process diagnostics and numerical simulation, key issues concerning in-flight particle status as well as the controlling physical mechanisms have been analyzed. A scientific and intellectual strategy for universal description of particle characteristics has been successfully developed.

Photo-thermal processing of semiconductor fibers and thin films

NASA Astrophysics Data System (ADS)

Gupta, Nishant

Furnace processing and rapid thermal processing (RTP) have been an integral part of several processing steps in semiconductor manufacturing. The performance of RTP techniques can be improved many times by exploiting quantum photo-effects of UV and vacuum ultraviolet (VUV) photons in thermal processing and this technique is known as rapid photo-thermal processing (RPP). As compared to furnace processing and RTP, RPP provides higher diffusion coefficient, lower stress and lower microscopic defects. In this work, a custom designed automated photo assisted processing system was built from individual parts and an incoherent light source. This photo-assisted processing system is used to anneal silica clad silicon fibers and deposit thin-films. To the best of our knowledge, incoherent light source based rapid photo-thermal processing (RPP) was used for the first time to anneal glass-clad silicon core optical fibers. X-ray diffraction examination, Raman spectroscopy and electrical measurements showed a considerable enhancement of structural and crystalline properties of RPP treated silicon fibers. Photons in UV and vacuum ultraviolet (VUV) regions play a very important role in improving the bulk and carrier transport properties of RPP-treated silicon optical fibers, and the resultant annealing permits a path forward to in situ enhancement of the structure and properties of these new crystalline core optical fibers. To explore further applications of RPP, thin-films of Calcium Copper Titanate (CaCu3Ti4O12) or CCTO and Copper (I) Oxide (Cu2O) were also deposited using photo-assisted metal-organic chemical vapor deposition (MOCVD) on Si/SiO2 and n-Si substrate respectively. CCTO is one of the most researched giant dielectric constant materials in recent years. The given photo-assisted MOCVD approach provided polycrystalline CCTO growth on a SiO2 surface with grain sizes as large as 410 nm. Copper (I) oxide (Cu2O) is a direct band gap semiconductor with p-type conductivity and is a potential candidate for multi-junction solar cells. X-ray diffraction study revealed a preferred orientation, as (200) oriented crystals of Cu2O are grown on both substrates. Also, electrical characterization of Cu2O/n-Si devices showed the lowest saturation current density of 1.5x10-12 A/cm 2 at zero bias. As a result, photo-assisted thermal processing has the potential of making the process more effective with enhanced device performance.

Effect of input data variability on estimations of the equivalent constant temperature time for microbial inactivation by HTST and retort thermal processing.

PubMed

Salgado, Diana; Torres, J Antonio; Welti-Chanes, Jorge; Velazquez, Gonzalo

2011-08-01

Consumer demand for food safety and quality improvements, combined with new regulations, requires determining the processor's confidence level that processes lowering safety risks while retaining quality will meet consumer expectations and regulatory requirements. Monte Carlo calculation procedures incorporate input data variability to obtain the statistical distribution of the output of prediction models. This advantage was used to analyze the survival risk of Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) and Clostridium botulinum spores in high-temperature short-time (HTST) milk and canned mushrooms, respectively. The results showed an estimated 68.4% probability that the 15 sec HTST process would not achieve at least 5 decimal reductions in M. paratuberculosis counts. Although estimates of the raw milk load of this pathogen are not available to estimate the probability of finding it in pasteurized milk, the wide range of the estimated decimal reductions, reflecting the variability of the experimental data available, should be a concern to dairy processors. Knowledge of the C. botulinum initial load and decimal thermal time variability was used to estimate an 8.5 min thermal process time at 110 °C for canned mushrooms reducing the risk to 10⁻⁹ spores/container with a 95% confidence. This value was substantially higher than the one estimated using average values (6.0 min) with an unacceptable 68.6% probability of missing the desired processing objective. Finally, the benefit of reducing the variability in initial load and decimal thermal time was confirmed, achieving a 26.3% reduction in processing time when standard deviation values were lowered by 90%. In spite of novel technologies, commercialized or under development, thermal processing continues to be the most reliable and cost-effective alternative to deliver safe foods. However, the severity of the process should be assessed to avoid under- and over-processing and determine opportunities for improvement. This should include a systematic approach to consider variability in the parameters for the models used by food process engineers when designing a thermal process. The Monte Carlo procedure here presented is a tool to facilitate this task for the determination of process time at a constant lethal temperature. © 2011 Institute of Food Technologists®

Thermal background noise limitations

NASA Technical Reports Server (NTRS)

Gulkis, S.

1982-01-01

Modern detection systems are increasingly limited in sensitivity by the background thermal photons which enter the receiving system. Expressions for the fluctuations of detected thermal radiation are derived. Incoherent and heterodyne detection processes are considered. References to the subject of photon detection statistics are given.

Thermal coefficients of technology assimilation by natural systems

NASA Technical Reports Server (NTRS)

Mueller, R. F.

1971-01-01

Estimates of thermal coefficients of the rates of technology assimilation processes was made. Consideration of such processes as vegetation and soil recovery and pollution assimilation indicates that these processes proceed ten to several hundred times more slowly in earth's cold regions than in temperate regions. It was suggested that these differential assimilation rates are important data in planning for technological expansion in Arctic regions.

Numerical evaluation and optimization of depth-oriented temperature measurements for the investigation of thermal influences on groundwater

NASA Astrophysics Data System (ADS)

Köhler, Mandy; Haendel, Falk; Epting, Jannis; Binder, Martin; Müller, Matthias; Huggenberger, Peter; Liedl, Rudolf

2015-04-01

Increasing groundwater temperatures have been observed in many urban areas such as London (UK), Tokyo (Japan) and also in Basel (Switzerland). Elevated groundwater temperatures are a result of different direct and indirect thermal impacts. Groundwater heat pumps, building structures located within the groundwater and district heating pipes, among others, can be addressed to direct impacts, whereas indirect impacts result from the change in climate in urban regions (i.e. reduced wind, diffuse heat sources). A better understanding of the thermal processes within the subsurface is urgently needed for decision makers as a basis for the selection of appropriate measures to reduce the ongoing increase of groundwater temperatures. However, often only limited temperature data is available that derives from measurements in conventional boreholes, which differ in construction and instrumental setup resulting in measurements that are often biased and not comparable. For three locations in the City of Basel models were implemented to study selected thermal processes and to investigate if heat-transport models can reproduce thermal measurements. Therefore, and to overcome the limitations of conventional borehole measurements, high-resolution depth-oriented temperature measurement systems have been introduced in the urban area of Basel. In total seven devices were installed with up to 16 sensors which are located in the unsaturated and saturated zone (0.5 to 1 m separation distance). Measurements were performed over a period of 4 years (ongoing) and provide sufficient data to set up and calibrate high-resolution local numerical heat transport models which allow studying selected local thermal processes. In a first setup two- and three-dimensional models were created to evaluate the impact of the atmosphere boundary on groundwater temperatures (see EGU Poster EGU2013-9230: Modelling Strategies for the Thermal Management of Shallow Rural and Urban Groundwater bodies). For Basel, where the mean thickness of the unsaturated zone amounts to 19 m, it could be observed that atmospheric seasonal temperature variations are small compared to advective groundwater heat transport. At chosen locations: i) near the river Rhine to study river-groundwater interaction processes, ii) downstream of a thermal groundwater user who uses water for cooling and infiltrates water with elevated temperatures and iii) downstream of a building structure reaching into the groundwater saturated zone, models were further extended to study selected thermal processes in detail and to investigate if these models can reproduce thermal impacts in the vicinity of the temperature measurement devices. Calibration, based on the depth-oriented temperature measurements, was performed for the saturated and unsaturated zone, respectively. Model results show that, although depth-oriented measurements provide valuable insights into local thermal processes, the identification of the governing impacts is strongly dependent on an appropriate positioning of the measurement device. Numerical simulations based on existing flow- and heat transport models, considering the site specific local hydraulic and thermal boundary conditions, allow optimizing the location of such systems before installation. Furthermore, the results of the local heat transport models can be transferred to regional scale models which are an important tool for thermal management in urban areas.

Changes in Effective Thermal Conductivity During the Carbothermic Reduction of Magnetite Using Graphite

NASA Astrophysics Data System (ADS)

Kiamehr, Saeed; Ahmed, Hesham; Viswanathan, Nurni; Seetharaman, Seshadri

2017-06-01

Knowledge of the effective thermal diffusivity changes of systems undergoing reactions where heat transfer plays an important role in the reaction kinetics is essential for process understanding and control. Carbothermic reduction process of magnetite containing composites is a typical example of such systems. The reduction process in this case is highly endothermic and hence, the overall rate of the reaction is greatly influenced by the heat transfer through composite compact. Using Laser-Flash method, the change of effective thermal diffusivity of magnetite-graphite composite pellet was monitored in the dynamic mode over a pre-defined thermal cycle (heating at the rate of 7 K/min to 1423 K (1150 °C), holding the sample for 270 minutes at this temperature and then cooling it down to the room temperature at the same rate as heating). These measurements were supplemented by Thermogravimetric Analysis under comparable experimental conditions as well as quenching tests of the samples in order to combine the impact of various factors such as sample dilatations and changes in apparent density on the progress of the reaction. The present results show that monitoring thermal diffusivity changes during the course of reduction would be a very useful tool in a total understanding of the underlying physicochemical phenomena. At the end, effort is made to estimate the apparent thermal conductivity values based on the measured thermal diffusivity and dilatations.

Process management using component thermal-hydraulic function classes

DOEpatents

Morman, James A.; Wei, Thomas Y. C.; Reifman, Jaques

1999-01-01

A process management expert system where following malfunctioning of a component, such as a pump, for determining system realignment procedures such as for by-passing the malfunctioning component with on-line speeds to maintain operation of the process at full or partial capacity or to provide safe shut down of the system while isolating the malfunctioning component. The expert system uses thermal-hydraulic function classes at the component level for analyzing unanticipated as well as anticipated component malfunctions to provide recommended sequences of operator actions. Each component is classified according to its thermal-hydraulic function, and the generic and component-specific characteristics for that function. Using the diagnosis of the malfunctioning component and its thermal hydraulic class, the expert system analysis is carried out using generic thermal-hydraulic first principles. One aspect of the invention employs a qualitative physics-based forward search directed primarily downstream from the malfunctioning component in combination with a subsequent backward search directed primarily upstream from the serviced component. Generic classes of components are defined in the knowledge base according to the three thermal-hydraulic functions of mass, momentum and energy transfer and are used to determine possible realignment of component configurations in response to thermal-hydraulic function imbalance caused by the malfunctioning component. Each realignment to a new configuration produces the accompanying sequence of recommended operator actions. All possible new configurations are examined and a prioritized list of acceptable solutions is produced.

Process management using component thermal-hydraulic function classes

DOEpatents

Morman, J.A.; Wei, T.Y.C.; Reifman, J.

1999-07-27

A process management expert system where following malfunctioning of a component, such as a pump, for determining system realignment procedures such as for by-passing the malfunctioning component with on-line speeds to maintain operation of the process at full or partial capacity or to provide safe shut down of the system while isolating the malfunctioning component. The expert system uses thermal-hydraulic function classes at the component level for analyzing unanticipated as well as anticipated component malfunctions to provide recommended sequences of operator actions. Each component is classified according to its thermal-hydraulic function, and the generic and component-specific characteristics for that function. Using the diagnosis of the malfunctioning component and its thermal hydraulic class, the expert system analysis is carried out using generic thermal-hydraulic first principles. One aspect of the invention employs a qualitative physics-based forward search directed primarily downstream from the malfunctioning component in combination with a subsequent backward search directed primarily upstream from the serviced component. Generic classes of components are defined in the knowledge base according to the three thermal-hydraulic functions of mass, momentum and energy transfer and are used to determine possible realignment of component configurations in response to thermal-hydraulic function imbalance caused by the malfunctioning component. Each realignment to a new configuration produces the accompanying sequence of recommended operator actions. All possible new configurations are examined and a prioritized list of acceptable solutions is produced. 5 figs.

Intelligent process development of foam molding for the Thermal Protection System (TPS) of the space shuttle external tank

NASA Technical Reports Server (NTRS)

Bharwani, S. S.; Walls, J. T.; Jackson, M. E.

1987-01-01

A knowledge based system to assist process engineers in evaluating the processability and moldability of poly-isocyanurate (PIR) formulations for the thermal protection system of the Space Shuttle external tank (ET) is discussed. The Reaction Injection Molding- Process Development Advisor (RIM-PDA) is a coupled system which takes advantage of both symbolic and numeric processing techniques. This system will aid the process engineer in identifying a startup set of mold schedules and in refining the mold schedules to remedy specific process problems diagnosed by the system.

Linear Friction Welding Process Model for Carpenter Custom 465 Precipitation-Hardened Martensitic Stainless Steel

DTIC Science & Technology

2014-04-11

Fig. 9(a) and (b). In addition, the temperature dependencies of the true and room-temperature-based mean values of the linear thermal expansion ...Variation of (a) thermal conductivity, (b) specific heat, (c) true linear thermal expansion coefficient, and (d) room-temperature-based mean thermal ...defined as follows: (a) alloy-grade and thermal -mechanical treatment of the workpiece materials to be joined, (b) frequency of reciprocating motion

21 CFR 113.87 - Operations in the thermal processing room.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Section 113.87 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY SEALED... Food and Drug Administration. (b) A system for product traffic control in the retort room shall be...

21 CFR 113.87 - Operations in the thermal processing room.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Section 113.87 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY SEALED... Administration. (b) A system for product traffic control in the retort room shall be estab-lished to prevent...

DEMONSTRATION BULLETIN: LOW TEMPERATURE THERMAL AERATION (LTTA®) SYSTEM - CANONIE ENVIRONMENTAL SERVICES, INC.

EPA Science Inventory

The Low Temperature Thermal Aeration (LTTA®) process was developed by Canonie Environmental Services, Inc. (Canonie), as a treatment system that desorbs organic contaminants from soils by heating the soils up to 800 °F. The main components of the LTTA process include the follow...

ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE THERMAL DESORPTION UNIT - APPLICATIONS ANALYSIS REPORT

EPA Science Inventory

ELI ECO Logic International, Inc.'s Thermal Desorption Unit (TDU) is specifically designed for use with Eco Logic's Gas Phase Chemical Reduction Process. The technology uses an externally heated bath of molten tin in a hydrogen atmosphere to desorb hazardous organic compounds fro...

Process for producing molybdenum foil and collapsible tubing

NASA Technical Reports Server (NTRS)

Bretts, G. R.; Gavert, R. B.; Groschke, G. F.

1971-01-01

Manufacturing process produces molybdenum foil 0.002 cm thick and 305 m long, and forms foil into high-strength, thin-walled tubing which can be flattened for storage on a spool. Desirable metal properties include high thermal conductivity stiffness, yield and tensile stress, and low thermal expansion coeffecient.

Startup of Pumping Units in Process Water Supplies with Cooling Towers at Thermal and Nuclear Power Plants

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

Berlin, V. V., E-mail: vberlin@rinet.ru; Murav’ev, O. A., E-mail: muraviov1954@mail.ru; Golubev, A. V., E-mail: electronik@inbox.ru

Aspects of the startup of pumping units in the cooling and process water supply systems for thermal and nuclear power plants with cooling towers, the startup stages, and the limits imposed on the extreme parameters during transients are discussed.

MOUNTAIN-SCALE COUPLED PROCESSES (TH/THC/THM)MODELS

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

Y.S. Wu

This report documents the development and validation of the mountain-scale thermal-hydrologic (TH), thermal-hydrologic-chemical (THC), and thermal-hydrologic-mechanical (THM) models. These models provide technical support for screening of features, events, and processes (FEPs) related to the effects of coupled TH/THC/THM processes on mountain-scale unsaturated zone (UZ) and saturated zone (SZ) flow at Yucca Mountain, Nevada (BSC 2005 [DIRS 174842], Section 2.1.1.1). The purpose and validation criteria for these models are specified in ''Technical Work Plan for: Near-Field Environment and Transport: Coupled Processes (Mountain-Scale TH/THC/THM, Drift-Scale THC Seepage, and Drift-Scale Abstraction) Model Report Integration'' (BSC 2005 [DIRS 174842]). Model results are used tomore » support exclusion of certain FEPs from the total system performance assessment for the license application (TSPA-LA) model on the basis of low consequence, consistent with the requirements of 10 CFR 63.342 [DIRS 173273]. Outputs from this report are not direct feeds to the TSPA-LA. All the FEPs related to the effects of coupled TH/THC/THM processes on mountain-scale UZ and SZ flow are discussed in Sections 6 and 7 of this report. The mountain-scale coupled TH/THC/THM processes models numerically simulate the impact of nuclear waste heat release on the natural hydrogeological system, including a representation of heat-driven processes occurring in the far field. The mountain-scale TH simulations provide predictions for thermally affected liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature (together called the flow fields). The main focus of the TH model is to predict the changes in water flux driven by evaporation/condensation processes, and drainage between drifts. The TH model captures mountain-scale three-dimensional flow effects, including lateral diversion and mountain-scale flow patterns. The mountain-scale THC model evaluates TH effects on water and gas chemistry, mineral dissolution/precipitation, and the resulting impact to UZ hydrologic properties, flow and transport. The mountain-scale THM model addresses changes in permeability due to mechanical and thermal disturbances in stratigraphic units above and below the repository host rock. The THM model focuses on evaluating the changes in UZ flow fields arising out of thermal stress and rock deformation during and after the thermal period (the period during which temperatures in the mountain are significantly higher than ambient temperatures).« less

The role of thermal energy storage in industrial energy conservation

NASA Technical Reports Server (NTRS)

Duscha, R. A.; Masica, W. J.

1979-01-01

Thermal Energy Storage for Industrial Applications is a major thrust of the Department of Energy's Thermal Energy Storage Program. Utilizing Thermal Energy Storage (TES) with process or reject heat recovery systems is shown to be extremely beneficial for several applications. Recent system studies resulting from contracts awarded by the Department of Energy (DOE) identified four especially significant industries where TES appears attractive - food processing, paper and pulp, iron and steel, and cement. Potential annual fuel savings with large scale implementation of near term TES systems for these industries is over 9,000,000 bbl of oil. This savings is due to recuperation and storage in the food processing industry, direct fuel substitution in the paper and pulp industry and reduction in electric utility peak fuel use through inplant production of electricity from utilization of reject heat in the steel and cement industries.

FREE RADICALS IN THERMALLY STERILIZED ACIDUM BORICUM AND OPTIMIZATION OF THIS PROCESS.

PubMed

Ramos, Paweł; Pilawa, Barbara

2015-01-01

Free radicals formation in the acidum boricum (AB) during thermal sterilization process was examined by an X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy. Acidum boricum was sterilized according to the pharmacopea norms at temperatures 160°C (120 min), 170°C (60 min), and 180°C (30 min). Free radicals (~10(17) spin/g) were thermally formed in these drug. The free radicals system revealed complex character, and the asymmetrical EPR spectra were measured. Mainly oxygen free radicals exist in the tested heated AB. Slower spin-lattice relaxation processes exist in AB sterilized at 160, 170 and 180°C. AB may be sterilized at temperatures 160, 170 and 180°C. For AB thermal sterilization at temperature 170°C is recommended. Free radicals concentrations changes during storage of the examined AB, and probably interactions with oxygen molecules may be responsible for this effect.

Design process for applying the nonlocal thermal transport iSNB model to a Polar-Drive ICF simulation

NASA Astrophysics Data System (ADS)

Cao, Duc; Moses, Gregory; Delettrez, Jacques; Collins, Timothy

2014-10-01

A design process is presented for the nonlocal thermal transport iSNB (implicit Schurtz, Nicolai, and Busquet) model to provide reliable nonlocal thermal transport in polar-drive ICF simulations. Results from the iSNB model are known to be sensitive to changes in the SNB ``mean free path'' formula, and the latter's original form required modification to obtain realistic preheat levels. In the presented design process, SNB mean free paths are first modified until the model can match temperatures from Goncharov's thermal transport model in 1D temperature relaxation simulations. Afterwards the same mean free paths are tested in a 1D polar-drive surrogate simulation to match adiabats from Goncharov's model. After passing the two previous steps, the model can then be run in a full 2D polar-drive simulation. This research is supported by the University of Rochester Laboratory for Laser Energetics.

Comparison of Direct Solar Energy to Resistance Heating for Carbothermal Reduction of Regolith

NASA Technical Reports Server (NTRS)

Muscatello, Anthony C.; Gustafson, Robert J.

2011-01-01

A comparison of two methods of delivering thermal energy to regolith for the carbo thermal reduction process has been performed. The comparison concludes that electrical resistance heating is superior to direct solar energy via solar concentrators for the following reasons: (1) the resistance heating method can process approximately 12 times as much regolith using the same amount of thermal energy as the direct solar energy method because of superior thermal insulation; (2) the resistance heating method is more adaptable to nearer-term robotic exploration precursor missions because it does not require a solar concentrator system; (3) crucible-based methods are more easily adapted to separation of iron metal and glass by-products than direct solar energy because the melt can be poured directly after processing instead of being remelted; and (4) even with projected improvements in the mass of solar concentrators, projected photovoltaic system masses are expected to be even lower.

Extraction of Curcumin Pigment from Indonesian Local Turmeric with Its Infrared Spectra and Thermal Decomposition Properties

NASA Astrophysics Data System (ADS)

Nandiyanto, A. B. D.; Wiryani, A. S.; Rusli, A.; Purnamasari, A.; Abdullah, A. G.; Ana; Widiaty, I.; Hurriyati, R.

2017-03-01

Curcumin is one of the pigments which is used as a spice in Asian cuisine, traditional cosmetic, and medicine. Therefore, process for getting curcumin has been widely studied. Here, the purpose of this study was to demonstrate the simple method for extracting curcumin from Indonesian local turmeric and investigate the infrared spectra and thermal decomposition properties. In the experimental procedure, the washed turmeric was dissolved into an ethanol solution, and then put into a rotary evaporator to enrich curcumin concentration. The result showed that the present method is effective to isolate curcumin compound from Indonesian local turmeric. Since the process is very simple, this method can be used for home industrial application. Further, understanding the thermal decomposition properties of curcumin give information, specifically relating to the selection of treatment when curcumin must face the thermal-related process.

Study of the electrical and thermal performances of photovoltaic thermal collector-compound parabolic concentrated

NASA Astrophysics Data System (ADS)

Jaaz, Ahed Hameed; Sopian, Kamaruzzaman; Gaaz, Tayser Sumer

2018-06-01

The importance of utilizing the solar energy as a very suitable source among multi-source approaches to replace the conventional energy is on the rise in the last four decades. The invention of the photovoltaic module (PV) could be the corner stone in this process. However, the limited amount of energy obtained from PV was and still the main challenge of full utilization of the solar energy. In this paper, the use of the compound parabolic concentrator (CPC) along with the thermal photovoltaic module (PVT) where the cooling process of the CPC is conducted using a novel technique of water jet impingement has applied experimentally and physically tested. The test includes the effect of water jet impingement on the total power, electrical efficiency, thermal efficiency, and total efficiency on CPC-PVT system. The cooling process at the maximum irradiation by water jet impingement resulted in improving the electrical efficiency by 7%, total output power by 31% and the thermal efficiency by 81%. These results outperform the recent highest results recorded by the most recent work.

Laser Heating of the Core-Shell Nanowires

NASA Astrophysics Data System (ADS)

Astefanoaei, Iordana; Dumitru, Ioan; Stancu, Alexandru

2016-12-01

The induced thermal stress in a heating process is an important parameter to be known and controlled in the magnetization process of core-shell nanowires. This paper analyses the stress produced by a laser heating source placed at one end of a core-shell type structure. The thermal field was computed with the non-Fourier heat transport equation using a finite element method (FEM) implemented in Comsol Multiphysics. The internal stresses are essentially due to thermal gradients and different expansion characteristics of core and shell materials. The stress values were computed using the thermo elastic formalism and are depending on the laser beam parameters (spot size, power etc.) and system characteristics (dimensions, thermal characteristics). Stresses in the GPa range were estimated and consequently we find that the magnetic state of the system can be influenced significantly. A shell material as the glass which is a good thermal insulator induces in the magnetic core, the smaller stresses and consequently the smaller magnetoelastic energy. These results lead to a better understanding of the switching process in the magnetic materials.

Disintegration impact on sludge digestion process.

PubMed

Dauknys, Regimantas; Rimeika, Mindaugas; Jankeliūnaitė, Eglė; Mažeikienė, Aušra

2016-11-01

The anaerobic sludge digestion is a widely used method for sludge stabilization in wastewater treatment plant. This process can be improved by applying the sludge disintegration methods. As the sludge disintegration is not investigated enough, an analysis of how the application of thermal hydrolysis affects the sludge digestion process based on full-scale data was conducted. The results showed that the maximum volatile suspended solids (VSS) destruction reached the value of 65% independently on the application of thermal hydrolysis. The average VSS destruction increased by 14% when thermal hydrolysis was applied. In order to have the maximum VSS reduction and biogas production, it is recommended to keep the maximum defined VSS loading of 5.7 kg VSS/m(3)/d when the thermal hydrolysis is applied and to keep the VSS loading between 2.1-2.4 kg VSS/m(3)/d when the disintegration of sludge is not applied. The application of thermal hydrolysis leads to an approximately 2.5 times higher VSS loading maintenance comparing VSS loading without the disintegration; therefore, digesters with 1.8 times smaller volume is required.

Thermal regulation in multiple-source arc welding involving material transformations

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

Doumanidis, C.C.

1995-06-01

This article addresses regulation of the thermal field generated during arc welding, as the cause of solidification, heat-affected zone and cooling rate related metallurgical transformations affecting the final microstructure and mechanical properties of various welded materials. This temperature field is described by a dynamic real-time process model, consisting of an analytical composite conduction expression for the solid region, and a lumped-state, double-stream circulation model in the weld pool, integrated with a Gaussian heat input and calibrated experimentally through butt joint GMAW tests on plain steel plates. This model serves as the basis of an in-process thermal control system employing feedbackmore » of part surface temperatures measured by infrared pyrometry; and real-time identification of the model parameters with a multivariable adaptive control strategy. Multiple heat inputs and continuous power distributions are implemented by a single time-multiplexed torch, scanning the weld surface to ensure independent, decoupled control of several thermal characteristics. Their regulation is experimentally obtained in longitudinal GTAW of stainless steel pipes, despite the presence of several geometrical, thermal and process condition disturbances of arc welding.« less

Thermal engineering of FAPbI3 perovskite material via radiative thermal annealing and in situ XRD

PubMed Central

Pool, Vanessa L.; Dou, Benjia; Van Campen, Douglas G.; Klein-Stockert, Talysa R.; Barnes, Frank S.; Shaheen, Sean E.; Ahmad, Md I.; van Hest, Maikel F. A. M.; Toney, Michael F.

2017-01-01

Lead halide perovskites have emerged as successful optoelectronic materials with high photovoltaic power conversion efficiencies and low material cost. However, substantial challenges remain in the scalability, stability and fundamental understanding of the materials. Here we present the application of radiative thermal annealing, an easily scalable processing method for synthesizing formamidinium lead iodide (FAPbI3) perovskite solar absorbers. Devices fabricated from films formed via radiative thermal annealing have equivalent efficiencies to those annealed using a conventional hotplate. By coupling results from in situ X-ray diffraction using a radiative thermal annealing system with device performances, we mapped the processing phase space of FAPbI3 and corresponding device efficiencies. Our map of processing-structure-performance space suggests the commonly used FAPbI3 annealing time, 10 min at 170 °C, can be significantly reduced to 40 s at 170 °C without affecting the photovoltaic performance. The Johnson-Mehl-Avrami model was used to determine the activation energy for decomposition of FAPbI3 into PbI2. PMID:28094249

Thermal stability of gallium arsenide solar cells

NASA Astrophysics Data System (ADS)

Papež, Nikola; Škvarenina, Ľubomír.; Tofel, Pavel; Sobola, Dinara

2017-12-01

This article summarizes a measurement of gallium arsenide (GaAs) solar cells during their thermal processing. These solar cells compared to standard silicon cells have better efficiency and high thermal stability. However, their use is partly limited due to high acquisition costs. For these reasons, GaAs cells are deployed only in the most demanding applications where their features are needed, such as space applications. In this work, GaAs solar cells were studied in a high temperature range within 30-650 °C where their functionality and changes in surface topology were monitored. These changes were recorded using an electron microscope which determined the position of the defects; using an atomic force microscope we determined the roughness of the surface and an infrared camera that showed us the thermal radiated places of the defected parts of the cell. The electrical characteristics of the cells during processing were determined by its current-voltage characteristics. Despite the occurrence of subtle changes on the solar cell with newly created surface features after 300 °C thermal processing, its current-voltage characteristic remained without a significant change.

Fabrication and characterization of self-folding thermoplastic sheets using unbalanced thermal shrinkage.

PubMed

Danielson, Christian; Mehrnezhad, Ali; YekrangSafakar, Ashkan; Park, Kidong

2017-06-14

Self-folding or micro-origami technologies are actively investigated as a novel manufacturing process to fabricate three-dimensional macro/micro-structures. In this paper, we present a simple process to produce a self-folding structure with a biaxially oriented polystyrene sheet (BOPS) or Shrinky Dinks. A BOPS sheet is known to shrink to one-third of its original size in plane, when it is heated above 160 °C. A grid pattern is engraved on one side of the BOPS film with a laser engraver to decrease the thermal shrinkage of the engraved side. The thermal shrinkage of the non-engraved side remains the same and this unbalanced thermal shrinkage causes folding of the structure as the structure shrinks at high temperature. We investigated the self-folding mechanism and characterized how the grid geometry, the grid size, and the power of the laser engraver affect the bending curvature. The developed fabrication process to locally modulate thermomechanical properties of the material by engraving the grid pattern and the demonstrated design methodology to harness the unbalanced thermal shrinkage can be applied to develop complicated self-folding macro/micro structures.

Thermal engineering of FAPbI 3 perovskite material via radiative thermal annealing and in situ XRD

DOE PAGES

Pool, Vanessa L.; Dou, Benjia; Van Campen, Douglas G.; ...

2017-01-17

Lead halide perovskites have emerged as successful optoelectronic materials with high photovoltaic power conversion efficiencies and low material cost. However, substantial challenges remain in the scalability, stability and fundamental understanding of the materials. Here we present the application of radiative thermal annealing, an easily scalable processing method for synthesizing formamidinium lead iodide (FAPbI 3) perovskite solar absorbers. Devices fabricated from films formed via radiative thermal annealing have equivalent efficiencies to those annealed using a conventional hotplate. By coupling results from in situ X-ray diffraction using a radiative thermal annealing system with device performances, we mapped the processing phase space ofmore » FAPbI 3 and corresponding device efficiencies. Our map of processing-structure-performance space suggests the commonly used FAPbI 3 annealing time, 10 min at 170 degrees C, can be significantly reduced to 40 s at 170 degrees C without affecting the photovoltaic performance. Lastly, the Johnson-Mehl-Avrami model was used to determine the activation energy for decomposition of FAPbI 3 into PbI 2.« less

Spatio-thermal depth correction of RGB-D sensors based on Gaussian processes in real-time

NASA Astrophysics Data System (ADS)

Heindl, Christoph; Pönitz, Thomas; Stübl, Gernot; Pichler, Andreas; Scharinger, Josef

2018-04-01

Commodity RGB-D sensors capture color images along with dense pixel-wise depth information in real-time. Typical RGB-D sensors are provided with a factory calibration and exhibit erratic depth readings due to coarse calibration values, ageing and thermal influence effects. This limits their applicability in computer vision and robotics. We propose a novel method to accurately calibrate depth considering spatial and thermal influences jointly. Our work is based on Gaussian Process Regression in a four dimensional Cartesian and thermal domain. We propose to leverage modern GPUs for dense depth map correction in real-time. For reproducibility we make our dataset and source code publicly available.

Thermal Catalytic Oxidation of Airborne Contaminants by a Reactor Using Ultra-Short Channel Length, Monolithic Catalyst Substrates

NASA Technical Reports Server (NTRS)

Perry, J. L.; Tomes, K. M.; Tatara, J. D.

2005-01-01

Contaminated air, whether in a crewed spacecraft cabin or terrestrial work and living spaces, is a pervasive problem affecting human health, performance, and well being. The need for highly effective, economical air quality processes spans a wide range of terrestrial and space flight applications. Typically, air quality control processes rely on absorption-based processes. Most industrial packed-bed adsorption processes use activated carbon. Once saturated, the carbon is either dumped or regenerated. In either case, the dumped carbon and concentrated waste streams constitute a hazardous waste that must be handled safely while minimizing environmental impact. Thermal catalytic oxidation processes designed to address waste handling issues are moving to the forefront of cleaner air quality control and process gas decontamination processes. Careful consideration in designing the catalyst substrate and reactor can lead to more complete contaminant destruction and poisoning resistance. Maintenance improvements leading to reduced waste handling and process downtime can also be realized. Performance of a prototype thermal catalytic reaction based on ultra-short waste channel, monolith catalyst substrate design, under a variety of process flow and contaminant loading conditions, is discussed.

Experimental Study of Thermal Runaway Process of 18650 Lithium-Ion Battery

PubMed Central

Liu, Jingjing; Wang, Zhirong; Gong, Junhui; Liu, Kai; Wang, Hao; Guo, Linsheng

2017-01-01

This study addresses the effects of the SOC (State of Charge) and the charging–discharging process on the thermal runaway of 18650 lithium-ion batteries. A series of experiments were conducted on an electric heating and testing apparatus. The experimental results indicate that 6 W is the critical heating power for 40% SOC. With a 20 W constant heating rate, the thermal runaway initial temperature of the lithium-ion battery decreases with the increasing SOC. The final thermal runaway temperature increases with the SOC when the SOC is lower than 80%. However, a contrary conclusion was obtained when the SOC was higher than 80%. Significant mass loss, accompanied by an intense exothermic reaction, took place under a higher SOC. The critical charging current, beyond which the thermal runaway occurs, was found to be 2.6 A. The thermal runaway initial temperature decreases with the increasing charging current, while the intensity of the exothermic reaction varies inversely. Mass ejection of gas and electrolytes exists during thermal runaway when the charging current is higher than 10.4 A, below which only a large amount of gas is released. The thermal runaway initial temperature of discharging is higher than that of non-discharging. PMID:28772588

Experimental Study of Thermal Runaway Process of 18650 Lithium-Ion Battery.

PubMed

Liu, Jingjing; Wang, Zhirong; Gong, Junhui; Liu, Kai; Wang, Hao; Guo, Linsheng

2017-02-25

This study addresses the effects of the SOC (State of Charge) and the charging-discharging process on the thermal runaway of 18650 lithium-ion batteries. A series of experiments were conducted on an electric heating and testing apparatus. The experimental results indicate that 6 W is the critical heating power for 40% SOC. With a 20 W constant heating rate, the thermal runaway initial temperature of the lithium-ion battery decreases with the increasing SOC. The final thermal runaway temperature increases with the SOC when the SOC is lower than 80%. However, a contrary conclusion was obtained when the SOC was higher than 80%. Significant mass loss, accompanied by an intense exothermic reaction, took place under a higher SOC. The critical charging current, beyond which the thermal runaway occurs, was found to be 2.6 A. The thermal runaway initial temperature decreases with the increasing charging current, while the intensity of the exothermic reaction varies inversely. Mass ejection of gas and electrolytes exists during thermal runaway when the charging current is higher than 10.4 A, below which only a large amount of gas is released. The thermal runaway initial temperature of discharging is higher than that of non-discharging.

Next Generation Ceramic Substrate Fabricated at Room Temperature.

PubMed

Kim, Yuna; Ahn, Cheol-Woo; Choi, Jong-Jin; Ryu, Jungho; Kim, Jong-Woo; Yoon, Woon-Ha; Park, Dong-Soo; Yoon, Seog-Young; Ma, Byungjin; Hahn, Byung-Dong

2017-07-26

A ceramic substrate must not only have an excellent thermal performance but also be thin, since the electronic devices have to become thin and small in the electronics industry of the next generation. In this manuscript, a thin ceramic substrate (thickness: 30-70 µm) is reported for the next generation ceramic substrate. It is fabricated by a new process [granule spray in vacuum (GSV)] which is a room temperature process. For the thin ceramic substrates, AlN GSV films are deposited on Al substrates and their electric/thermal properties are compared to those of the commercial ceramic substrates. The thermal resistance is significantly reduced by using AlN GSV films instead of AlN bulk-ceramics in thermal management systems. It is due to the removal of a thermal interface material which has low thermal conductivity. In particular, the dielectric strengths of AlN GSV films are much higher than those of AlN bulk-ceramics which are commercialized, approximately 5 times. Therefore, it can be expected that this GSV film is a next generation substrate in thermal management systems for the high power application.

Double-Layer Gadolinium Zirconate/Yttria-Stabilized Zirconia Thermal Barrier Coatings Deposited by the Solution Precursor Plasma Spray Process

NASA Astrophysics Data System (ADS)

Jiang, Chen; Jordan, Eric H.; Harris, Alan B.; Gell, Maurice; Roth, Jeffrey

2015-08-01

Advanced thermal barrier coatings (TBCs) with lower thermal conductivity, increased resistance to calcium-magnesium-aluminosilicate (CMAS), and improved high-temperature capability, compared to traditional yttria-stabilized zirconia (YSZ) TBCs, are essential to higher efficiency in next generation gas turbine engines. Double-layer rare-earth zirconate/YSZ TBCs are a promising solution. From a processing perspective, solution precursor plasma spray (SPPS) process with its unique and beneficial microstructural features can be an effective approach to obtaining the double-layer microstructure. Previously durable low-thermal-conductivity YSZ TBCs with optimized layered porosity, called the inter-pass boundaries (IPBs) were produced using the SPPS process. In this study, an SPPS gadolinium zirconate (GZO) protective surface layer was successfully added. These SPPS double-layer TBCs not only retained good cyclic durability and low thermal conductivity, but also demonstrated favorable phase stability and increased surface temperature capabilities. The CMAS resistance was evaluated with both accumulative and single applications of simulated CMAS in isothermal furnaces. The double-layer YSZ/GZO exhibited dramatic improvement in the single application, but not in the continuous one. In addition, to explore their potential application in integrated gasification combined cycle environments, double-layer TBCs were tested under high-temperature humidity and encouraging performance was recorded.

Desorption of isopropyl alcohol from adsorbent with non-thermal plasma.

PubMed

Shiau, Chen Han; Pan, Kuan Lun; Yu, Sheng Jen; Yan, Shaw Yi; Chang, Moo Been

2017-09-01

Effective desorption of isopropyl alcohol (IPA) from adsorbents with non-thermal plasma is developed. In this system, IPA is effectively adsorbed with activated carbon while dielectric barrier discharge is applied to replace the conventional thermal desorption process to achieve good desorption efficiency, making the treatment equipment smaller in size. Various adsorbents including molecular sieves and activated carbon are evaluated for IPA adsorption capacity. The results indicate that BAC has the highest IPA adsorption capacity (280.31 mg IPA/g) under the operating conditions of room temperature, IPA of 400 ppm, and residence time of 0.283 s among 5 adsorbents tested. For the plasma desorption process, the IPA selectivity of 89% is achieved with BAC as N 2 is used as desorbing gas. In addition, as air or O 2 is used as desorbing gas, the IPA desorption concentration is reduced, because air and O 2 plasmas generate active species to oxidize IPA to form acetone, CO 2 , and even CO. Furthermore, the results of the durability test indicate that the amount of IPA desorbed increases with increasing desorption times and plasma desorption process has a higher energy efficiency if compared with thermal desorption. Overall, this study indicates that non-thermal plasma is a viable process for removing VOCs to regenerate adsorbent.

Research of a possibility of receiving sorbents for a sewage disposal from a wastage of coal preparation factory

NASA Astrophysics Data System (ADS)

Buyantuev, S. L.; Kondratenko, A. S.; Shishulkin, S. Y.; Stebenkova, Y. Y.; Khmelev, A. B.

2017-05-01

The paper presents the results of the studies of the structure and porosity of the coal cake processed by electric arc plasma. The main limiting factor in processing of coal cakes sorbents is their high water content. As a result of coal washing, the main share of water introduced into the cake falls on hard-hydrate and colloidal components. This makes impossible application of traditional processes of manufacturing from a cake of coal sorbents. Using the electric arc intensifies the processes of thermal activation of coal cakes associated with thermal shock, destruction and vapor-gas reactions occurring at the surfaces of the particles at an exposure temperature of up to 3000 °C, which increases the title product outlet (sorbent) and thereby reduces manufacturing costs and improves environmental performance. The investigation of the thermal activation zone is carried out in the plasma reactor chamber by thermal imaging method followed by mapping-and 3D-modeling of temperature fields. the most important physical and chemical properties of the sorbents from coal cake activated by plasma was studied. The obtained results showed the possibility of coal cake thermal activation by electric arc plasma to change its material composition, the appearance of porosity and associated sorption capacity applied for wastewater treatment.

Two-dimensional thermal video analysis of offshore bird and bat flight

DOE PAGES

Matzner, Shari; Cullinan, Valerie I.; Duberstein, Corey A.

2015-09-11

Thermal infrared video can provide essential information about bird and bat presence and activity for risk assessment studies, but the analysis of recorded video can be time-consuming and may not extract all of the available information. Automated processing makes continuous monitoring over extended periods of time feasible, and maximizes the information provided by video. This is especially important for collecting data in remote locations that are difficult for human observers to access, such as proposed offshore wind turbine sites. We present guidelines for selecting an appropriate thermal camera based on environmental conditions and the physical characteristics of the target animals.more » We developed new video image processing algorithms that automate the extraction of bird and bat flight tracks from thermal video, and that characterize the extracted tracks to support animal identification and behavior inference. The algorithms use a video peak store process followed by background masking and perceptual grouping to extract flight tracks. The extracted tracks are automatically quantified in terms that could then be used to infer animal type and possibly behavior. The developed automated processing generates results that are reproducible and verifiable, and reduces the total amount of video data that must be retained and reviewed by human experts. Finally, we suggest models for interpreting thermal imaging information.« less

Two-dimensional thermal video analysis of offshore bird and bat flight

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

Matzner, Shari; Cullinan, Valerie I.; Duberstein, Corey A.

Thermal infrared video can provide essential information about bird and bat presence and activity for risk assessment studies, but the analysis of recorded video can be time-consuming and may not extract all of the available information. Automated processing makes continuous monitoring over extended periods of time feasible, and maximizes the information provided by video. This is especially important for collecting data in remote locations that are difficult for human observers to access, such as proposed offshore wind turbine sites. We present guidelines for selecting an appropriate thermal camera based on environmental conditions and the physical characteristics of the target animals.more » We developed new video image processing algorithms that automate the extraction of bird and bat flight tracks from thermal video, and that characterize the extracted tracks to support animal identification and behavior inference. The algorithms use a video peak store process followed by background masking and perceptual grouping to extract flight tracks. The extracted tracks are automatically quantified in terms that could then be used to infer animal type and possibly behavior. The developed automated processing generates results that are reproducible and verifiable, and reduces the total amount of video data that must be retained and reviewed by human experts. Finally, we suggest models for interpreting thermal imaging information.« less

Experimental and numerical study of two dimensional heat and mass transfer in unsaturated soil with and application to soil thermal energy storage (SBTES) systems

NASA Astrophysics Data System (ADS)

Moradi, A.; Smits, K. M.

2014-12-01

A promising energy storage option to compensate for daily and seasonal energy offsets is to inject and store heat generated from renewable energy sources (e.g. solar energy) in the ground, oftentimes referred to as soil borehole thermal energy storage (SBTES). Nonetheless in SBTES modeling efforts, it is widely recognized that the movement of water vapor is closely coupled to thermal processes. However, their mutual interactions are rarely considered in most soil water modeling efforts or in practical applications. The validation of numerical models that are designed to capture these processes is difficult due to the scarcity of experimental data, limiting the testing and refinement of heat and water transfer theories. A common assumption in most SBTES modeling approaches is to consider the soil as a purely conductive medium with constant hydraulic and thermal properties. However, this simplified approach can be improved upon by better understanding the coupled processes at play. Consequently, developing new modeling techniques along with suitable experimental tools to add more complexity in coupled processes has critical importance in obtaining necessary knowledge in efficient design and implementation of SBTES systems. The goal of this work is to better understand heat and mass transfer processes for SBTES. In this study, we implemented a fully coupled numerical model that solves for heat, liquid water and water vapor flux and allows for non-equilibrium liquid/gas phase change. This model was then used to investigate the influence of different hydraulic and thermal parameterizations on SBTES system efficiency. A two dimensional tank apparatus was used with a series of soil moisture, temperature and soil thermal properties sensors. Four experiments were performed with different test soils. Experimental results provide evidences of thermally induced moisture flow that was also confirmed by numerical results. Numerical results showed that for the test conditions applied here, moisture flow is more influenced by thermal gradients rather than hydraulic gradients. The results also demonstrate that convective fluxes are higher compared to conductive fluxes indicating that moisture flow has more contribution to the overall heat flux than conductive fluxes.

Thermal stability of poly(3-hydroxybutyrate)/vegetable fiber composites

NASA Astrophysics Data System (ADS)

Cipriano, Pâmela Bento; de Sá, Mayelli Dantas; Andrade, André L. Simões; de Carvalho, Laura Hecker; Canedo, Eduardo Luis

2015-05-01

The present work deals with the thermal stability during and after processing of composites of poly(3-hydroxybutyrate) (PHB) - a fully biodegradable semi-crystalline thermoplastic obtained from renewable resources through low-impact biotechnological process, biocompatible and non-toxic - and vegetable fiber from the fruit (coconut) of babassu palm tree. PHB/babassu composites with 0, 5, 10 and 20% w/w load were prepared in a laboratory internal mixer. Two fractions of the mesocarp of babassu with different particle sizes were compounded with PHB and test specimens molded by compression. The effect of loading level and processing conditions on torque, temperature and mechanical energy dissipation were studied using a new engineering model. It was found that PHB degrades during processing at temperatures slightly above the melting point. To minimize thermal degradation stabilizer and chain extender additives were incorporated, with mixed results. These findings were confirmed by the dependence of the melt flow rate on the processing temperature.

Direct ink writing of 3D conductive polyaniline structures and rheological modelling

NASA Astrophysics Data System (ADS)

Holness, F. Benjamin; Price, Aaron D.

2018-01-01

The intractable nature of conjugated polymers (CP) leads to practical limitations in the fabrication of CP-based transducers having complex three-dimensional geometries. Conventional CP device fabrication processes have focused primarily on thin-film deposition techniques; this study explores novel additive manufacturing processes specifically developed for CP with the ultimate goal of increasing the functionality of CP sensors and actuators. Herein we employ automated polymer paste extrusion processes for the direct ink writing of 3D conductive polyaniline (PANI) structures. Realization of these structures was enabled through a modified fused filament fabrication delta robot equipped with an integrated polymer paste extruder to fabricate high-resolution 3D conductive PANI structures. The required processability of PANI was achieved by means of a counterion-induced thermal doping method. The effect of thermal doping on the PANI-DBSA paste by means of a constitutive relationship to describe the paste flow as a function of the thermal doping time is explored. This relationship is incorporated within a flow model to predict the extruded track width as a function of various process parameters including: print speed, gauge pressure, nozzle diameter, and pre-extrusion thermal doping time.

Method and apparatus for a combination moving bed thermal treatment reactor and moving bed filter

DOEpatents

Badger, Phillip C.; Dunn, Jr., Kenneth J.

2015-09-01

A moving bed gasification/thermal treatment reactor includes a geometry in which moving bed reactor particles serve as both a moving bed filter and a heat carrier to provide thermal energy for thermal treatment reactions, such that the moving bed filter and the heat carrier are one and the same to remove solid particulates or droplets generated by thermal treatment processes or injected into the moving bed filter from other sources.

Thermal-Wave Microscope

NASA Technical Reports Server (NTRS)

Jones, Robert E.; Kramarchuk, Ihor; Williams, Wallace D.; Pouch, John J.; Gilbert, Percy

1989-01-01

Computer-controlled thermal-wave microscope developed to investigate III-V compound semiconductor devices and materials. Is nondestructive technique providing information on subsurface thermal features of solid samples. Furthermore, because this is subsurface technique, three-dimensional imaging also possible. Microscope uses intensity-modulated electron beam of modified scanning electron microscope to generate thermal waves in sample. Acoustic waves generated by thermal waves received by transducer and processed in computer to form images displayed on video display of microscope or recorded on magnetic disk.

A novel multi-actuation CMOS RF MEMS switch

NASA Astrophysics Data System (ADS)

Lee, Chiung-I.; Ko, Chih-Hsiang; Huang, Tsun-Che

2008-12-01

This paper demonstrates a capacitive shunt type RF MEMS switch, which is actuated by electro-thermal actuator and electrostatic actuator at the same time, and than latching the switching status by electrostatic force only. Since thermal actuators need relative low voltage compare to electrostatic actuators, and electrostatic force needs almost no power to maintain the switching status, the benefits of the mechanism are very low actuation voltage and low power consumption. Moreover, the RF MEMS switch has considered issues for integrated circuit compatible in design phase. So the switch is fabricated by a standard 0.35um 2P4M CMOS process and uses wet etching and dry etching technologies for postprocess. This compatible ability is important because the RF characteristics are not only related to the device itself. If a packaged RF switch and a packaged IC wired together, the parasitic capacitance will cause the problem for optimization. The structure of the switch consists of a set of CPW transmission lines and a suspended membrane. The CPW lines and the membrane are in metal layers of CMOS process. Besides, the electro-thermal actuators are designed by polysilicon layer of the CMOS process. So the RF switch is only CMOS process layers needed for both electro-thermal and electrostatic actuations in switch. The thermal actuator is composed of a three-dimensional membrane and two heaters. The membrane is a stacked step structure including two metal layers in CMOS process, and heat is generated by poly silicon resistors near the anchors of membrane. Measured results show that the actuation voltage of the switch is under 7V for electro-thermal added electrostatic actuation.

Strong and Consistently Synergistic Inactivation of Spores of Spoilage-Associated Bacillus and Geobacillus spp. by High Pressure and Heat Compared with Inactivation by Heat Alone ▿ †

PubMed Central

Olivier, S. A.; Bull, M. K.; Stone, G.; van Diepenbeek, R. J.; Kormelink, F.; Jacops, L.; Chapman, B.

2011-01-01

The inactivation of spores of four low-acid food spoilage organisms by high pressure thermal (HPT) and thermal-only processing was compared on the basis of equivalent thermal lethality calculated at a reference temperature of 121.1°C (Fz121.1°C, 0.1 MPa or 600 MPa) and characterized as synergistic, not different or protective. In addition, the relative resistances of spores of the different spoilage microorganisms to HPT processing were compared. Processing was performed and inactivation was compared in both laboratory and pilot scale systems and in model (diluted) and actual food products. Where statistical comparisons could be made, at least 4 times and up to around 190 times more inactivation (log10 reduction/minute at FTz121.1°C) of spores of Bacillus amyloliquefaciens, Bacillus sporothermodurans, and Geobacillus stearothermophilus was achieved using HPT, indicating a strong synergistic effect of high pressure and heat. Bacillus coagulans spores were also synergistically inactivated in diluted and undiluted Bolognese sauce but were protected by pressure against thermal inactivation in undiluted cream sauce. Irrespective of the response characterization, B. coagulans and B. sporothermodurans were identified as the most HPT-resistant isolates in the pilot scale and laboratory scale studies, respectively, and G. stearothermophilus as the least in both studies and all products. This is the first study to comprehensively quantitatively characterize the responses of a range of spores of spoilage microorganisms as synergistic (or otherwise) using an integrated thermal-lethality approach (FTz). The use of the FTz approach is ultimately important for the translation of commercial minimum microbiologically safe and stable thermal processes to HPT processes. PMID:21278265

Strong and consistently synergistic inactivation of spores of spoilage-associated Bacillus and Geobacillus spp. by high pressure and heat compared with inactivation by heat alone.

PubMed

Olivier, S A; Bull, M K; Stone, G; van Diepenbeek, R J; Kormelink, F; Jacops, L; Chapman, B

2011-04-01

The inactivation of spores of four low-acid food spoilage organisms by high pressure thermal (HPT) and thermal-only processing was compared on the basis of equivalent thermal lethality calculated at a reference temperature of 121.1°C (F(z)(121.1)(°)(C, 0.1 MPa or 600 MPa)) and characterized as synergistic, not different or protective. In addition, the relative resistances of spores of the different spoilage microorganisms to HPT processing were compared. Processing was performed and inactivation was compared in both laboratory and pilot scale systems and in model (diluted) and actual food products. Where statistical comparisons could be made, at least 4 times and up to around 190 times more inactivation (log(10) reduction/minute at F(T)(z)(121.1)(°)(C)) of spores of Bacillus amyloliquefaciens, Bacillus sporothermodurans, and Geobacillus stearothermophilus was achieved using HPT, indicating a strong synergistic effect of high pressure and heat. Bacillus coagulans spores were also synergistically inactivated in diluted and undiluted Bolognese sauce but were protected by pressure against thermal inactivation in undiluted cream sauce. Irrespective of the response characterization, B. coagulans and B. sporothermodurans were identified as the most HPT-resistant isolates in the pilot scale and laboratory scale studies, respectively, and G. stearothermophilus as the least in both studies and all products. This is the first study to comprehensively quantitatively characterize the responses of a range of spores of spoilage microorganisms as synergistic (or otherwise) using an integrated thermal-lethality approach (F(T)(z)). The use of the F(T)(z) approach is ultimately important for the translation of commercial minimum microbiologically safe and stable thermal processes to HPT processes.

Thermally Activated Delayed Fluorescence in Polymers: A New Route toward Highly Efficient Solution Processable OLEDs.

PubMed

Nikolaenko, Andrey E; Cass, Michael; Bourcet, Florence; Mohamad, David; Roberts, Matthew

2015-11-25

Efficient intermonomer thermally activated delayed fluorescence is demonstrated for the first time, opening a new route to achieving high-efficiency solution processable polymer light-emitting device materials. External quantum efficiency (EQE) of up to 10% is achieved in a simple fully solution-processed device structure, and routes for further EQE improvement identified. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-density Bi-Pb-Sr-Ca-Cu-O superconductor prepared by rapid thermal melt processing

NASA Astrophysics Data System (ADS)

Moon, B. M.; Lalevic, B.; Kear, B. H.; McCandlish, L. E.; Safari, A.; Meskoob, M.

1989-10-01

A high quality, dense Bi-Pb-Sr-Ca-Cu-O superconductor has been successfully synthesized by rapid thermal melt processing. Conventionally sintered pellets were melted at 1200 °C, cooled rapidly, and then annealed. As-melted samples exhibited semiconductor behavior, which upon annealing became superconducting at 115 K [Tc(zero)=105 K]. A detailed study of various processing techniques has been carried out.

Innovative Ration Preservation via Supercritical Carbon Dioxide

DTIC Science & Technology

2012-07-01

processing in destroying unwanted enzymes and microbes before spoilage, browning, or other damage to the food can occur. SCCO2 is a non-thermal, generally...regarded as safe (GRAS) treatment and a novel alternative to traditional thermal processing , which can cause product quality degradation. The CO2 is...discussion of the direction of future research related to SCCO2 processing . 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

Advanced Image Processing for Defect Visualization in Infrared Thermography

NASA Technical Reports Server (NTRS)

Plotnikov, Yuri A.; Winfree, William P.

1997-01-01

Results of a defect visualization process based on pulse infrared thermography are presented. Algorithms have been developed to reduce the amount of operator participation required in the process of interpreting thermographic images. The algorithms determine the defect's depth and size from the temporal and spatial thermal distributions that exist on the surface of the investigated object following thermal excitation. A comparison of the results from thermal contrast, time derivative, and phase analysis methods for defect visualization are presented. These comparisons are based on three dimensional simulations of a test case representing a plate with multiple delaminations. Comparisons are also based on experimental data obtained from a specimen with flat bottom holes and a composite panel with delaminations.

Influences of different thermal processings in milk, bovine meat and frog protein structure.

PubMed

Coura Oliveira, Tatiana; Lopes Lima, Samuel; Bressan, Josefina

2013-01-01

Several studies have associated the digestibility of proteins to its imunogenic potential. Though, it was objectified to evaluate the impact of the thermal processing with high and low temperatures on the proteins structure of three types of foods, by means of the digestibility in vitro and electroforesis en gel de poliacrilamida. The pasteurize was observed in such a way, firing 95 ºC during 15 minutes, how much freeze dried causes qualitative and quantitative modifications of constituent proteins of the food. The most sensible proteins to the increasing thermal processing order were beef, frog meat, and the last, cow milk. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

Manufacture of micro fluidic devices by laser welding using thermal transfer printing techniques

NASA Astrophysics Data System (ADS)

Klein, R.; Klein, K. F.; Tobisch, T.; Thoelken, D.; Belz, M.

2016-03-01

Micro-fluidic devices are widely used today in the areas of medical diagnostics and drug research, as well as for applications within the process, electronics and chemical industry. Microliters of fluids or single cell to cell interactions can be conveniently analyzed with such devices using fluorescence imaging, phase contrast microscopy or spectroscopic techniques. Typical micro-fluidic devices consist of a thermoplastic base component with chambers and channels covered by a hermetic fluid and gas tight sealed lid component. Both components are usually from the same or similar thermoplastic material. Different mechanical, adhesive or thermal joining processes can be used to assemble base component and lid. Today, laser beam welding shows the potential to become a novel manufacturing opportunity for midsize and large scale production of micro-fluidic devices resulting in excellent processing quality by localized heat input and low thermal stress to the device during processing. For laser welding, optical absorption of the resin and laser wavelength has to be matched for proper joining. This paper will focus on a new approach to prepare micro-fluidic channels in such devices using a thermal transfer printing process, where an optical absorbing layer absorbs the laser energy. Advantages of this process will be discussed in combination with laser welding of optical transparent micro-fluidic devices.

Development of process data capturing, analysis and controlling for thermal spray techniques - SprayTracker

NASA Astrophysics Data System (ADS)

Kelber, C.; Marke, S.; Trommler, U.; Rupprecht, C.; Weis, S.

2017-03-01

Thermal spraying processes are becoming increasingly important in high-technology areas, such as automotive engineering and medical technology. The method offers the advantage of a local layer application with different materials and high deposition rates. Challenges in the application of thermal spraying result from the complex interaction of different influencing variables, which can be attributed to the properties of different materials, operating equipment supply, electrical parameters, flow mechanics, plasma physics and automation. In addition, spraying systems are subject to constant wear. Due to the process specification and the high demands on the produced coatings, innovative quality assurance tools are necessary. A central aspect, which has not yet been considered, is the data management in relation to the present measured variables, in particular the spraying system, the handling system, working safety devices and additional measuring sensors. Both the recording of all process-characterizing variables, their linking and evaluation as well as the use of the data for the active process control presuppose a novel, innovative control system (hardware and software) that was to be developed within the scope of the research project. In addition, new measurement methods and sensors are to be developed and qualified in order to improve the process reliability of thermal spraying.

Chemical transitions of Areca semen during the thermal processing revealed by temperature-resolved ATR-FTIR spectroscopy and two-dimensional correlation analysis

NASA Astrophysics Data System (ADS)

Wang, Zhibiao; Wang, Xu; Pei, Wenxuan; Li, Sen; Sun, Suqin; Zhou, Qun; Chen, Jianbo

2018-03-01

Areca semen is a common herb used in traditional Chinese medicine, but alkaloids in this herb are categorized as Group I carcinogens by IARC. It has been proven that the stir-baking process can reduce alkaloids in Areca semen while keep the activity for promoting digestion. However, the changes of compositions other than alkaloids during the thermal processing are unclear. Understanding the thermal chemical transitions of Areca semen is necessary to explore the processing mechanisms and optimize the procedures. In this research, FTIR spectroscopy with a temperature-controlled ATR accessory is employed to study the heating process of Areca semen. Principal component analysis and two-dimensional correlation spectroscopy are used to interpret the spectra to reveal the chemical transitions of Areca semen in different temperature ranges. The loss of a few volatile compounds in the testa and sperm happens below 105 °C, while some esters in the sperm decreases above 105 °C. As the heating temperature is close to 210 °C, Areca semen begins to be scorched and the decomposition of many compounds can be observed. This research shows the potential of the temperature-resolved ATR-FTIR spectroscopy in exploring the chemical transitions of the thermal processing of herbal materials.

Comparative Study of Microstructure and Properties of Thermal Sprayed MCrAlY Bond Coatings

NASA Astrophysics Data System (ADS)

Inglima, Michael William

A series of experiments were performed in order to observe certain process-property trends in thermally sprayed MCrAlY bond coatings for thermal barrier coating (TBC) applications in gas-turbine engines. Firstly, the basis of gas-turbine operation and design is discussed with a focus on the Brayton cycle and basic thermodynamic properties with respect to both the thermal and fuel efficiency of the turbine. The high-temperature environment inside the gas-turbine engine creates an extremely corrosive medium in which the engineering components must operate with sufficient operating life times. These engineering constraints, both thermal/fuel efficiency and operating life, pose a serious problem during long operation as well as thermal cycling of a civil aerospace engine. The concept of a thermal barrier coating is introduced along with how these coatings protect the internal engineering components, mostly in the hot-section of the turbine, and increase both the efficiency as well as the operating life of the components. The method used to create TBC's is then introduced being thermal spray processing along with standard operating procedures (SOP) used during coating deposition. The main focus of the experiments was to quantify the process-property trends seen during thermal spray processing of TBC's with respect to the adhesion and thermally grown oxide (TGO) layer, as well as how sensitive these properties are to changing variables during coating deposition. The design of experiment (DOE) method was used in order to have sufficient statistical process control over the output as well as a standard method for quantifying the results. A total of three DOE's were performed using two main types of thermal spray processes being high-velocity oxygen fuel (HVOF) and atmospheric plasma spray (APS), with a total of five different types of torches which are categorized by liquid-fuel, gas-fuel, and single cathode plasma. The variables used in the proceeding experiments were mainly spray distance, air/fuel ratio, raster speed, powder feed rate, combustion pressure, current, primary and secondary gas flow, as well as three different powder chemistries. The results of the experiments showed very clear process-property trends with respect to mean bond strength of the coatings as well as TGO growth on the as-sprayed coating surface. The effect of either increasing/decreasing the melting index of the powder as well as increasing/decreasing the kinetic energy of the particles is shown with corresponding cross-sectional microstructures of the coating interfaces. The temperature and velocity of the particles were measured with spray diagnostic sensors as well as using an in-situ curvature property sensor (ICP) to monitor the stress-states of the coatings both during deposition as well as residual stresses, and how these might affect the bond strength. An SOP referred to as furnace cycling was used to quantify the TGO growth of the bond coatings by measuring the thickness via a scanning electron microscope (SEM) as well as performing energy dispersive x-ray spectroscopy (EDX) on the coatings to measure chemical changes.

High-Temperature Helical-Tube Solar Receiver

NASA Technical Reports Server (NTRS)

Robertson, C. S., Jr.; Mccreight, L.

1984-01-01

Solar-thermal receiver used with circular parabolic concentrator to supply about 58 kW thermal power to Brayton engine or industrial process. Solar radiation focused into open end of cylindrical ceramic thermal inertial sleeve 8 in. in diameter that reradiates energy to helical heatexchanger tube surrounding sleeve.

Waxy soft white wheat: extrusion characteristics and thermal and rheological properties

USDA-ARS?s Scientific Manuscript database

Waxy wheat flour was analyzed for its thermal and rheological properties and extruded to understand its processing characteristics. Comparisons were made with normal soft white wheat flour to identify extrusion differences under the same conditions. The thermal and rheological properties through Rap...

Pulse Thermal Processing for Low Thermal Budget Integration of IGZO Thin Film Transistors

DOE PAGES

Noh, Joo Hyon; Joshi, Pooran C.; Kuruganti, Teja; ...

2014-11-26

Pulse thermal processing (PTP) has been explored for low thermal budget integration of indium gallium zinc oxide (IGZO) thin film transistors (TFTs). The IGZO TFTs are exposed to a broadband (0.2-1.4 m) arc lamp radiation spectrum with 100 pulses of 1 msec pulse width. The impact of radiant exposure power on the TFT performance was analyzed in terms of the switching characteristics and bias stress reliability characteristics, respectively. The PTP treated IGZO TFTs with power density of 3.95 kW/cm 2 and 0.1 sec total irradiation time showed comparable switching properties, at significantly lower thermal budget, to furnace annealed IGZO TFT.more » The typical field effect mobility FE, threshold voltage VT, and sub-threshold gate swing S.S were calculated to be 7.8 cm 2/ V s, 8.1 V, and 0.22 V/ decade, respectively. The observed performance shows promise for low thermal budget TFT integration on flexible substrates exploiting the large-area, scalable PTP technology.« less

Pulse Thermal Processing for Low Thermal Budget Integration of IGZO Thin Film Transistors

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

Noh, Joo Hyon; Joshi, Pooran C.; Kuruganti, Teja

Pulse thermal processing (PTP) has been explored for low thermal budget integration of indium gallium zinc oxide (IGZO) thin film transistors (TFTs). The IGZO TFTs are exposed to a broadband (0.2-1.4 m) arc lamp radiation spectrum with 100 pulses of 1 msec pulse width. The impact of radiant exposure power on the TFT performance was analyzed in terms of the switching characteristics and bias stress reliability characteristics, respectively. The PTP treated IGZO TFTs with power density of 3.95 kW/cm 2 and 0.1 sec total irradiation time showed comparable switching properties, at significantly lower thermal budget, to furnace annealed IGZO TFT.more » The typical field effect mobility FE, threshold voltage VT, and sub-threshold gate swing S.S were calculated to be 7.8 cm 2/ V s, 8.1 V, and 0.22 V/ decade, respectively. The observed performance shows promise for low thermal budget TFT integration on flexible substrates exploiting the large-area, scalable PTP technology.« less

Heat flow bounds over the Cascadia margin derived from bottom simulating reflectors and implications for thermal models of subduction

NASA Astrophysics Data System (ADS)

Phrampus, Benjamin J.; Harris, Robert N.; Tréhu, Anne M.

2017-09-01

Understanding the thermal structure of the Cascadia subduction zone is important for understanding megathrust earthquake processes and seismogenic potential. Currently our understanding of the thermal structure of Cascadia is limited by a lack of high spatial resolution heat flow data and by poor understanding of thermal processes such as hydrothermal fluid circulation in the subducting basement, sediment thickening and dewatering, and frictional heat generation on the plate boundary. Here, using a data set of publically available seismic lines combined with new interpretations of bottom simulating reflector (BSR) distributions, we derive heat flow estimates across the Cascadia margin. Thermal models that account for hydrothermal circulation predict BSR-derived heat flow bounds better than purely conductive models, but still over-predict surface heat flows. We show that when the thermal effects of in-situ sedimentation and of sediment thickening and dewatering due to accretion are included, models with hydrothermal circulation become consistent with our BSR-derived heat flow bounds.

Time-resolved investigations of the non-thermal ablation process of graphite induced by femtosecond laser pulses

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

Kalupka, C., E-mail: christian.kalupka@llt.rwth-aachen.de; Finger, J.; Reininghaus, M.

2016-04-21

We report on the in-situ analysis of the ablation dynamics of the, so-called, laser induced non-thermal ablation process of graphite. A highly oriented pyrolytic graphite is excited by femtosecond laser pulses with fluences below the classic thermal ablation threshold. The ablation dynamics are investigated by axial pump-probe reflection measurements, transversal pump-probe shadowgraphy, and time-resolved transversal emission photography. The combination of the applied analysis methods allows for a continuous and detailed time-resolved observation of the non-thermal ablation dynamics from several picoseconds up to 180 ns. Formation of large, μm-sized particles takes place within the first 3.5 ns after irradiation. The following propagation ofmore » ablation products and the shock wave front are tracked by transversal shadowgraphy up to 16 ns. The comparison of ablation dynamics of different fluences by emission photography reveals thermal ablation products even for non-thermal fluences.« less

Collective thermal transport in pure and alloy semiconductors.

PubMed

Torres, Pol; Mohammed, Amr; Torelló, Àlvar; Bafaluy, Javier; Camacho, Juan; Cartoixà, Xavier; Shakouri, Ali; Alvarez, F Xavier

2018-03-07

Conventional models for predicting thermal conductivity of alloys usually assume a pure kinetic regime as alloy scattering dominates normal processes. However, some discrepancies between these models and experiments at very small alloy concentrations have been reported. In this work, we use the full first principles kinetic collective model (KCM) to calculate the thermal conductivity of Si 1-x Ge x and In x Ga 1-x As alloys. The calculated thermal conductivities match well with the experimental data for all alloy concentrations. The model shows that the collective contribution must be taken into account at very low impurity concentrations. For higher concentrations, the collective contribution is suppressed, but normal collisions have the effect of significantly reducing the kinetic contribution. The study thus shows the importance of the proper inclusion of normal processes even for alloys for accurate modeling of thermal transport. Furthermore, the phonon spectral distribution of the thermal conductivity is studied in the framework of KCM, providing insights to interpret the superdiffusive regime introduced in the truncated Lévy flight framework.

A comparison of suit dresses and summer clothes in the terms of thermal comfort.

PubMed

Ekici, Can; Atilgan, Ibrahim

2013-12-19

Fanger's PMV equation is the result of the combined quantitative effects of the air temperature, mean radiant temperature, relative air velocity, humidity, activity level and clothing insulation. This paper contains a comparison of suit dresses and summer clothes in terms of thermal comfort, Fanger's PMV equation. Studies were processed in the winter for an office, which locates in Ankara, Turkey. The office was partitioned to fifty square cells. Humidity, relative air velocity, air temperature and mean radiant temperature were measured on the centre points of these cells. Thermal comfort analyses were processed for suit dressing (Icl = 1 clo) and summer clothing (Icl = 0.5 clo). Discomfort/comfort in an environment for different clothing types can be seen in this study. The relationship between indoor thermal comfort distribution and clothing type was discussed. Graphics about thermal comfort were sketched according to cells. Conclusions about the thermal comfort of occupants were given by PMV graphics.

A comparison of suit dresses and summer clothes in the terms of thermal comfort

PubMed Central

2013-01-01

Background Fanger’s PMV equation is the result of the combined quantitative effects of the air temperature, mean radiant temperature, relative air velocity, humidity, activity level and clothing insulation. Methods This paper contains a comparison of suit dresses and summer clothes in terms of thermal comfort, Fanger’s PMV equation. Studies were processed in the winter for an office, which locates in Ankara, Turkey. The office was partitioned to fifty square cells. Humidity, relative air velocity, air temperature and mean radiant temperature were measured on the centre points of these cells. Thermal comfort analyses were processed for suit dressing (Icl = 1 clo) and summer clothing (Icl = 0.5 clo). Results Discomfort/comfort in an environment for different clothing types can be seen in this study. The relationship between indoor thermal comfort distribution and clothing type was discussed. Graphics about thermal comfort were sketched according to cells. Conclusions Conclusions about the thermal comfort of occupants were given by PMV graphics. PMID:24355097

Effect of biomimetic non-smooth unit morphology on thermal fatigue behavior of H13 hot-work tool steel

NASA Astrophysics Data System (ADS)

Meng, Chao; Zhou, Hong; Cong, Dalong; Wang, Chuanwei; Zhang, Peng; Zhang, Zhihui; Ren, Luquan

2012-06-01

The thermal fatigue behavior of hot-work tool steel processed by a biomimetic coupled laser remelting process gets a remarkable improvement compared to untreated sample. The 'dowel pin effect', the 'dam effect' and the 'fence effect' of non-smooth units are the main reason of the conspicuous improvement of the thermal fatigue behavior. In order to get a further enhancement of the 'dowel pin effect', the 'dam effect' and the 'fence effect', this study investigated the effect of different unit morphologies (including 'prolate', 'U' and 'V' morphology) and the same unit morphology in different sizes on the thermal fatigue behavior of H13 hot-work tool steel. The results showed that the 'U' morphology unit had the optimum thermal fatigue behavior, then the 'V' morphology which was better than the 'prolate' morphology unit; when the unit morphology was identical, the thermal fatigue behavior of the sample with large unit sizes was better than that of the small sizes.

The Development of HfO2-Rare Earth Based Oxide Materials and Barrier Coatings for Thermal Protection Systems

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan James

2014-01-01

Advanced hafnia-rare earth oxides, rare earth aluminates and silicates have been developed for thermal environmental barrier systems for aerospace propulsion engine and thermal protection applications. The high temperature stability, low thermal conductivity, excellent oxidation resistance and mechanical properties of these oxide material systems make them attractive and potentially viable for thermal protection systems. This paper will focus on the development of the high performance and high temperature capable ZrO2HfO2-rare earth based alloy and compound oxide materials, processed as protective coating systems using state-or-the-art processing techniques. The emphasis has been in particular placed on assessing their temperature capability, stability and suitability for advanced space vehicle entry thermal protection systems. Fundamental thermophysical and thermomechanical properties of the material systems have been investigated at high temperatures. Laser high-heat-flux testing has also been developed to validate the material systems, and demonstrating durability under space entry high heat flux conditions.

Engineering Interface Structures and Thermal Stabilities via SPD Processing in Bulk Nanostructured Metals

DOE PAGES

Zheng, Shijian; Carpenter, John S.; McCabe, Rodney J.; ...

2014-02-27

Nanostructured metals achieve extraordinary strength but suffer from low thermal stability, both a consequence of a high fraction of interfaces. Overcoming this tradeoff relies on making the interfaces themselves thermally stable. In this paper, we show that the atomic structures of bi-metal interfaces in macroscale nanomaterials suitable for engineering structures can be significantly altered via changing the severe plastic deformation (SPD) processing pathway. Two types of interfaces are formed, both exhibiting a regular atomic structure and providing for excellent thermal stability, up to more than half the melting temperature of one of the constituents. Most importantly, the thermal stability ofmore » one is found to be significantly better than the other, indicating the exciting potential to control and optimize macroscale robustness via atomic-scale bimetal interface tuning. As a result, we demonstrate an innovative way to engineer pristine bimetal interfaces for a new class of simultaneously strong and thermally stable materials.« less

Thermal fatigue as the origin of regolith on small asteroids.

PubMed

Delbo, Marco; Libourel, Guy; Wilkerson, Justin; Murdoch, Naomi; Michel, Patrick; Ramesh, K T; Ganino, Clément; Verati, Chrystele; Marchi, Simone

2014-04-10

Space missions and thermal infrared observations have shown that small asteroids (kilometre-sized or smaller) are covered by a layer of centimetre-sized or smaller particles, which constitute the regolith. Regolith generation has traditionally been attributed to the fall back of impact ejecta and by the break-up of boulders by micrometeoroid impact. Laboratory experiments and impact models, however, show that crater ejecta velocities are typically greater than several tens of centimetres per second, which corresponds to the gravitational escape velocity of kilometre-sized asteroids. Therefore, impact debris cannot be the main source of regolith on small asteroids. Here we report that thermal fatigue, a mechanism of rock weathering and fragmentation with no subsequent ejection, is the dominant process governing regolith generation on small asteroids. We find that thermal fragmentation induced by the diurnal temperature variations breaks up rocks larger than a few centimetres more quickly than do micrometeoroid impacts. Because thermal fragmentation is independent of asteroid size, this process can also contribute to regolith production on larger asteroids. Production of fresh regolith originating in thermal fatigue fragmentation may be an important process for the rejuvenation of the surfaces of near-Earth asteroids, and may explain the observed lack of low-perihelion, carbonaceous, near-Earth asteroids.

Mixed Waste Focus Area alternative oxidation technologies development and demonstration program

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

Borduin, L.C.; Fewell, T.; Gombert, D.

1998-07-01

The Mixed Waste Focus Area (MWFA) is currently supporting the development and demonstration of several alternative oxidation technology (AOT) processes for treatment of combustible mixed low-level wastes. The impetus for this support derives from regulatory and political hurdles frequently encountered by traditional thermal techniques, primarily incinerators. AOTs have been defined as technologies that destroy organic material without using open-flame reactions. Whether thermal or nonthermal, the processes have the potential advantages of relatively low-volume gaseous emissions, generation of few or no dioxin/furan compounds, and operation at low enough temperatures that metals (except mercury) and most radionuclides are not volatilized. Technology developmentmore » and demonstration are needed to confirm and realize the potential of AOTs and to compare them on an equal basis with their fully demonstrated thermal counterparts. AOTs include both thermal and nonthermal processes that oxidize organic wastes but operate under significantly different physical and chemical conditions than incinerators. Nonthermal processes currently being studied include Delphi DETOX and acid digestion at the Savannah River Site, and direct chemical oxidation at Lawrence Livermore National Laboratory. All three technologies are at advanced stages of development or are entering the demonstration phase. Nonflame thermal processes include catalytic chemical oxidation, which is being developed and deployed at Lawrence Berkeley National Laboratory, and team reforming, a commercial process being supported by Department of Energy. Related technologies include two low-flow, secondary oxidation processes (Phoenix and Thermatrix units) that have been tested at MSE, Inc., in Butte, Montana. Although testing is complete on some AOT technologies, most require additional support to complete some or all of the identified development objectives. Brief descriptions, status, and planned paths forward for each of the technologies are presented.« less

Quantifying the thermal evolution of early passive margins formation and its consequences on the structure of passive margins

NASA Astrophysics Data System (ADS)

Bousquet, Romain; Nalpas, Thierry

2017-04-01

Many large-scale dynamic processes, from continental rifting to plate subduction, are intimately linked to metamorphic reactions. This close relation between geodynamic processes and metamorphic reactions is, in spite of appearances, yet poorly understood. For example, during extension processes, rocks will be exposed to important temperature, pressures and stress changes. Meanwhile less attention has been paid to other important aspects of the metamorphic processes. When reacting rocks expand and contract, density and volume changes will set up in the surrounding material. While several tectonic models are proposed to explain the formation of extensive basins and passive margins ( simple shear detachment mantle exhumation .... ) a single thermal model (McKenzie, 1978), as a kind of dogma, is used to understanding and modeling the formation and evolution of sedimentary basins. The study of the thermal evolution, coupled with other tectonic models, and its consequences have never been studied in detail, although the differences may be significant. And it is clear that the petrological changes associated with changes in temperature conditions, influence changes reliefs. Constrained by the new field data of north Pyrenean basins on thermal evolution of pre-rift and syn-rift sediments, we explore the petrological changes associated to different thermal evolution and the consequences on the subsidence of the basins. We will also present numerical models quantifying mineralogical and physical changes inside the whole lithosphere during rifting processes. In the light of these models, we discuss the consequences of different thermal evolution on the subsidence processes as well as on gravimetry and seismic velocities signature of passive margins. We are able to distinguish two types of margins according to their thermal evolution: - An Alpine-type basin in which the temperature rise is 50 to 100 Ma older than the tectonic extension, leading to the "cold" opening of the ocean. - A Pyrenean type basin in which temperature changes are synchronous with basin formation, leading to a crustal boudignage and to the formation of a "anomalous" geophysical layer at the OCT

Reliability of CCGA 1152 and CCGA 1272 Interconnect Packages for Extreme Thermal Environments

NASA Technical Reports Server (NTRS)

Ramesham, Rajeshuni

2013-01-01

Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages of high interconnect density, very good thermal and electrical performance, and compatibility with standard surface-mount packaging assembly processes. CCGA packages are used in space applications such as in logics and microprocessor functions, telecommunications, flight avionics, and payload electronics. As these packages tend to have less solder joint strain relief than leaded packages, the reliability of CCGA packages is very important for short- and long-term space missions. Certain planetary satellites require operations of thermally uncontrolled hardware under extremely cold and hot temperatures with large diurnal temperature change from day to night. The planetary protection requires the hardware to be baked at +125 C for 72 hours to kill microbugs to avoid any biological contamination, especially for sample return missions. Therefore, the present CCGA package reliability research study has encompassed the temperature range of 185 to +125 C to cover various NASA deep space missions. Advanced 1152 and 1272 CCGA packaging interconnects technology test hardware objects have been subjected to ex treme temperature thermal cycles from 185 to +125 C. X-ray inspections of CCGA packages have been made before thermal cycling. No anomalous behavior and process problems were observed in the x-ray images. The change in resistance of the daisy-chained CCGA interconnects was measured as a function of increasing number of thermal cycles. Electrical continuity measurements of daisy chains have shown no anomalies, even until 596 thermal cycles. Optical inspections of hardware have shown a significant fatigue for CCGA 1152 packages over CCGA 1272 packages. No catastrophic failures have been observed yet in the results. Process qualification and assembly are required to optimize the CCGA assembly processes. Optical inspections of CCGA boards have been made after 258 and 596 thermal cycles. Corner columns have started showing significant fatigue per optical inspection results.

Effect of Suspension Plasma-Sprayed YSZ Columnar Microstructure and Bond Coat Surface Preparation on Thermal Barrier Coating Properties

NASA Astrophysics Data System (ADS)

Bernard, Benjamin; Quet, Aurélie; Bianchi, Luc; Schick, Vincent; Joulia, Aurélien; Malié, André; Rémy, Benjamin

2017-08-01

Suspension plasma spraying (SPS) is identified as promising for the enhancement of thermal barrier coating (TBC) systems used in gas turbines. Particularly, the emerging columnar microstructure enabled by the SPS process is likely to bring about an interesting TBC lifetime. At the same time, the SPS process opens the way to a decrease in thermal conductivity, one of the main issues for the next generation of gas turbines, compared to the state-of-the-art deposition technique, so-called electron beam physical vapor deposition (EB-PVD). In this paper, yttria-stabilized zirconia (YSZ) coatings presenting columnar structures, performed using both SPS and EB-PVD processes, were studied. Depending on the columnar microstructure readily adaptable in the SPS process, low thermal conductivities can be obtained. At 1100 °C, a decrease from 1.3 W m-1 K-1 for EB-PVD YSZ coatings to about 0.7 W m-1 K-1 for SPS coatings was shown. The higher content of porosity in the case of SPS coatings increases the thermal resistance through the thickness and decreases thermal conductivity. The lifetime of SPS YSZ coatings was studied by isothermal cyclic tests, showing equivalent or even higher performances compared to EB-PVD ones. Tests were performed using classical bond coats used for EB-PVD TBC coatings. Thermal cyclic fatigue performance of the best SPS coating reached 1000 cycles to failure on AM1 substrates with a β-(Ni,Pt)Al bond coat. Tests were also performed on AM1 substrates with a Pt-diffused γ-Ni/γ'-Ni3Al bond coat for which more than 2000 cycles to failure were observed for columnar SPS YSZ coatings. The high thermal compliance offered by both the columnar structure and the porosity allowed the reaching of a high lifetime, promising for a TBC application.

A time-resolved current method and TSC under vacuum conditions of SEM: Trapping and detrapping processes in thermal aged XLPE insulation cables

NASA Astrophysics Data System (ADS)

Boukezzi, L.; Rondot, S.; Jbara, O.; Boubakeur, A.

2017-03-01

Thermal aging of cross-linked polyethylene (XLPE) can cause serious concerns in the safety operation in high voltage system. To get a more detailed picture on the effect of thermal aging on the trapping and detrapping process of XLPE in the melting temperature range, Thermal Stimulated Current (TSC) have been implemented in a Scanning Electron Microscope (SEM) with a specific arrangement. The XLPE specimens are molded and aged at two temperatures (120 °C and 140 °C) situated close to the melting temperature of the material. The use of SEM allows us to measure both leakage and displacement currents induced in samples under electron irradiation. The first represents the conduction process of XLPE and the second gives information on the trapping of charges in the bulk of the material. TSC associated to the SEM leads to show spectra of XLPE discharge under thermal stimulation using both currents measured after electron irradiation. It was found that leakage current in the charging process may be related to the physical defects resulting in crystallinity variation under thermal aging. However the trapped charge can be affected by the carbonyl groups resulting from the thermo-oxidation degradation and the disorder in the material. It is evidenced from the TSC spectra of unaged XLPE that there is no detrapping charge under heat stimulation. Whereas the presence of peaks in the TSC spectra of thermally aged samples indicates that there is some amount of trapped charge released by heating. The detrapping behavior of aged XLPE is supported by the supposition of the existence of two trap levels: shallow traps and deep traps. Overall, physico-chemical reactions under thermal aging at high temperatures leads to the enhancement of shallow traps density and changes in range of traps depth. These changes induce degradation of electrical properties of XLPE.

Identification of a thermal processing-induced modification site on the Ana o 3 cashew allergen

USDA-ARS?s Scientific Manuscript database

Cashew nuts are a common cause of food allergy and reactions to cashew nuts can be severe. Thermal processing can alter the properties of food allergens including their structure, solubility, and cause non-enzymatic reactions between reactive sugar carbonyl groups and amino groups within proteins. ...

Thermal energy storage for industrial waste heat recovery

NASA Technical Reports Server (NTRS)

Hoffman, H. W.; Kedl, R. J.; Duscha, R. A.

1978-01-01

Thermal energy storage systems designed for energy conservation through the recovery, storage, and reuse of industrial process waste heat are reviewed. Consideration is given to systems developed for primary aluminum, cement, the food processing industry, paper and pulp, and primary iron and steel. Projected waste-heat recovery and energy savings are listed for each category.

Shelf-Life Study of an Orange Juice-Milk Based Beverage after PEF and Thermal Processing

USDA-ARS?s Scientific Manuscript database

The effect of thermal and pulsed electric field (PEF) processing on the shelf-life of an orange juice-milk beverage (OJMB) was studied. The intensities of the treatments were selected to produce similar inactivation of pectin methyl esterase (PME), an enzyme responsible for the jellification and los...

Stabilized thermally beneficiated low rank coal and method of manufacture

DOEpatents

Viall, Arthur J.; Richards, Jeff M.

1999-01-01

A process for reducing the spontaneous combustion tendencies of thermally beneficiated low rank coals employing heat, air or an oxygen containing gas followed by an optional moisture addition. Specific reaction conditions are supplied along with knowledge of equipment types that may be employed on a commercial scale to complete the process.

Stabilized thermally beneficiated low rank coal and method of manufacture

DOEpatents

Viall, Arthur J.; Richards, Jeff M.

2000-01-01

A process for reducing the spontaneous combustion tendencies of thermally beneficiated low rank coals employing heat, air or an oxygen containing gas followed by an optional moisture addition. Specific reaction conditions are supplied along with knowledge of equipment types that may be employed on a commercial scale to complete the process.

Multi-allergen Quantitation and the Impact of Thermal Treatment in Industry-Processed Baked Goods by ELISA and Liquid Chromatography-Tandem Mass Spectrometry.

PubMed

Parker, Christine H; Khuda, Sefat E; Pereira, Marion; Ross, Mark M; Fu, Tong-Jen; Fan, Xuebin; Wu, Yan; Williams, Kristina M; DeVries, Jonathan; Pulvermacher, Brian; Bedford, Binaifer; Zhang, Xi; Jackson, Lauren S

2015-12-16

Undeclared food allergens account for 30-40% of food recalls in the United States. Compliance with ingredient labeling regulations and the implementation of effective manufacturing allergen control plans require the use of reliable methods for allergen detection and quantitation in complex food products. The objectives of this work were to (1) produce industry-processed model foods incurred with egg, milk, and peanut allergens, (2) compare analytical method performance for allergen quantitation in thermally processed bakery products, and (3) determine the effects of thermal treatment on allergen detection. Control and allergen-incurred cereal bars and muffins were formulated in a pilot-scale industry processing facility. Quantitation of egg, milk, and peanut in incurred baked goods was compared at various processing stages using commercial enzyme-linked immunosorbent assay (ELISA) kits and a novel multi-allergen liquid chromatography (LC)-tandem mass spectrometry (MS/MS) multiple-reaction monitoring (MRM) method. Thermal processing was determined to negatively affect the recovery and quantitation of egg, milk, and peanut to different extents depending on the allergen, matrix, and analytical test method. The Morinaga ELISA and LC-MS/MS quantitative methods reported the highest recovery across all monitored allergens, whereas the ELISA Systems, Neogen BioKits, Neogen Veratox, and R-Biopharm ELISA Kits underperformed in the determination of allergen content of industry-processed bakery products.

Modifying Mechanical, Optical Properties and Thermal Processability of Iridescent Cellulose Nanocrystal Films Using Ionic Liquid.

PubMed

Liu, Ping; Guo, Xin; Nan, Fuchun; Duan, Yongxin; Zhang, Jianming

2017-01-25

Iridescent films formed from the self-assembly of cellulose nanocrystals (CNCs) are brittle and difficult to handle or integrate within an industrial process. Here we present a simple approach to prepare iridescent CNC films with tunable pliability and coloration through the addition of ionic liquids (ILs) of 1-allyl-3-methylimidazolium chloride (AmimCl) as plasticizers. By using the undried CNC film as a filter membrane and ILs solution as a leaching liquid, it was found that the filtration process made ILs uniformly interpenetrate into CNC film due to the strong ionic interaction between CNC and AmimCl. Unexpectedly, the filtration process also gave rise to partial desulfurization of CNC film, which is conducive to the improvement of thermal stability. Benefiting from the improved thermal stability and the dissolving capacity of AmimCl for cellulose at high temperature, the incorporated ILs enable the cholesteric CNC film to be further toughened via a hot-pressing treatment. This study demonstrates that ionic liquids have great potential to modify the mechanical, optical properties as well as the thermal stability of iridescent CNC films.

Effect of natural phenolics on the thermal and processing behaviour of poly(3-hydroxybutyrate)

NASA Astrophysics Data System (ADS)

Auriemma, Maria; Piscitelli, Amodio; Pasquino, Rossana; Cerruti, Pierfrancesco; Angelini, Stefania; Scarinzi, Gennaro; Malinconico, Mario; Grizzuti, Nino

2015-12-01

Poly(3-hydroxybutyrate) (PHB) is a biodegradable polymer, whose applicability is limited by its relatively poor mechanical properties and narrow processing window. In this paper, different natural phenol-based additives, including tannic acid (TA), grape bagasse extract (EP), and a lignocellulosic biomass (LC) were used as thermal and processing stabilizers for PHB. The thermal stability of both neat and doped PHB samples was studied by rheology and calorimetry. The experimental results showed that neat PHB massively degrades and that the addition of phenol additives enhances the thermal stability of PHB, preserving the polymer molecular weight after processing. This finding was in agreement with the slower decay in viscosity observed through rheological tests. Physical and chemical interactions between polymer and additive were considered as key factors to interpret the experimental data. LC affected the melt crystallization kinetics of PHB enhancing crystallization upon cooling. This finding suggests that LC was a heterogeneous nucleating agent, potentially able to control the physical aging of PHB. The described results are of interest for the development of sustainable alternatives to synthetic polymer additives, by increasing the applicability of bio-based materials.

Molecular disassembly of rice and lotus starches during thermal processing and its effect on starch digestibility.

PubMed

Wang, Shujun; Sun, Yue; Wang, Jinrong; Wang, Shuo; Copeland, Les

2016-02-01

The molecular disassembly of starch during thermal processing is a major determinant for the susceptibility of starch to enzymatic digestion. In the present study, the effects of thermal processing on the disassembly of the granular structure and the in vitro enzymatic digestibility of rice and lotus starches were investigated. After heating at 50 °C, rice and lotus starches did not show significant changes in granular morphology, long-range crystallinity and short-range molecular order. As the temperature increased to 60 °C, rice starch underwent a partial gelatinization followed by an incomplete disruption of granular morphology, crystallites and molecular order. In contrast, lotus starch was almost completely gelatinized at 60 °C. At 70 °C or higher, both starches were fully gelatinized with complete disruption of the micro and macro structures. Our results show that gelatinization greatly increased the in vitro enzymatic digestibility of both starches, but that the degree of disassembly of the starch structure during thermal processing was not a major determinant of the digestibility of gelatinized starch.

Feasibility and process scale-up low cost alumina fibers for advanced Re-usable Surface Insulation (RSI)

NASA Technical Reports Server (NTRS)

Pearson, A.

1975-01-01

The objective of this program was to establish feasibility of a process to produce low cost aluminum oxide fibers having sufficient strength, flexibility, and thermal stability for multiple re-use at temperatures to 1480 C in advanced RSI type heat shields for reentry vehicles. Using bench-scale processing apparatus, the Alcoa 'Saphiber' process was successfully modified to produce nominally 8 microns diameter polycrystalline alpha-alumina fiber. Thermal stability was demonstrated in vacuum reheating tests to 1371 C and in atmospheric reheating to 1483 C. Individual fiber properties of strength, modulus, and flexibility were not determined because of friability and short length of the fiber. Rigidized tile produced from fiber of nominally 8, 20 and 40 micron diameter had thermal conductivities significantly higher than those of RSI SiO2 or mullite at relatively low temperature but became comparable above about 1000 C. Tile densities were high due to short fiber length, especially in the coarser diameter fiber. No significant effect of fiber diameter on thermal properties could be determined form the data. Mechanical properties of tiles deteriorated as fiber diameter increased.

Preparation, melting behavior and thermal stability of poly(lactic acid)/poly(propylene carbonate) blends processed by vane extruder

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

Zou, Wei, E-mail: zw55624@163.com; Chen, Rongyuan; Zhang, Haichen

Poly (lactic acid) (PLA)/Poly (propylene carbonate) (PPC) blends were prepared by vane extruder which is a type of novel polymer processing extruder based on elongation force field. Scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermogravimetric (TG) were used respectively to analyze the compatibility, the melting behavior and thermal stability properties of PLA/PPC blends affected by the different content of PPC. The results showed that with the increase of the PPC content, the glass transition temperature of PLA was reduced, and the glass transition temperature of PPC was increased, which indicated that PLA and PPC had partial compatibility. Themore » cold crystallization temperature of PLA increased with the increase of the PPC content, which showed that PPC hindered the cold crystallization process of PLA. The addition of PPC had little impact on the melting process of PLA, and the melting temperature of PLA was almost kept the same value. Thermogravimetric analysis showed that the thermal stability of PPC was worse than that of PLA, the addition of PPC reduced the thermal stability of PLA.« less

Changes in water-soluble vitamins and antioxidant capacity of fruit juice-milk beverages as affected by high-intensity pulsed electric fields (HIPEF) or heat during chilled storage.

PubMed

Salvia-Trujillo, Laura; Morales-de la Peña, Mariana; Rojas-Graü, Alejandra; Martín-Belloso, Olga

2011-09-28

The effect of high-intensity pulsed electric fields (HIPEF) or thermal processes and refrigerated storage on water-soluble vitamins and antioxidant capacity of beverages containing fruit juices and whole (FJ-WM) or skim milk (FJ-SM) was assessed. Peroxidase (POD) and lipoxygenase (LOX) inactivation as well as color changes were also studied. High vitamin C retention was observed in HIPEF and thermally treated beverages, but a significant depletion of the vitamin during storage occurred, which was correlated with antioxidant capacity. HIPEF treatment did not affect the concentration of group B vitamins, which also remained constant over time, but thermally treated beverages showed lower riboflavin (vitamin B2) concentration. With regard to enzyme activity, thermal processing was more effective than HIPEF on POD and LOX inactivation. The color of the beverages was maintained after HIPEF processing and during storage. Consequently, HIPEF processing could be a feasible technology to attain beverages with fruit juices and milk with high vitamin content and antioxidant potential.

Precipitation of lamellar gold nanocrystals in molten polymers

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

Palomba, M.; Carotenuto, G., E-mail: giancaro@unina.it

Non-aggregated lamellar gold crystals with regular shape (triangles, squares, pentagons, etc.) have been produced by thermal decomposition of gold chloride (AuCl) molecules in molten amorphous polymers (polystyrene and poly(methyl methacrylate)). Such covalent inorganic gold salt is high soluble into non-polar polymers and it thermally decomposes at temperatures compatible with the polymer thermal stability, producing gold atoms and chlorine radicals. At the end of the gold precipitation process, the polymer matrix resulted chemically modified because of the partial cross-linking process due to the gold atom formation reaction.

Computational Study of Collisions Between O(3P) and NO(2Pi) at Temperatures Relevant to the Hypersonic Flight Regime

DTIC Science & Technology

2014-10-29

hypersonic flight regime. For this reason, the thermal rate coefficients for reactive processes involving O(3P) and NO(2_) are relevant over a wide...hypersonic flight regime. For this reason, the thermal rate coefficients for reactive processes involving O(3P) and NO(2) are relevant over a wide...N) is of particular interest since the thermal dissociation threshold for O2 is lower than that for N2 in air. A central question is how

Thermal imaging measurement of lateral diffusivity and non-invasive material defect detection

DOEpatents

Sun, Jiangang; Deemer, Chris

2003-01-01

A system and method for determining lateral thermal diffusivity of a material sample using a heat pulse; a sample oriented within an orthogonal coordinate system; an infrared camera; and a computer that has a digital frame grabber, and data acquisition and processing software. The mathematical model used within the data processing software is capable of determining the lateral thermal diffusivity of a sample of finite boundaries. The system and method may also be used as a nondestructive method for detecting and locating cracks within the material sample.

Multiobjective optimization approach: thermal food processing.

PubMed

Abakarov, A; Sushkov, Y; Almonacid, S; Simpson, R

2009-01-01

The objective of this study was to utilize a multiobjective optimization technique for the thermal sterilization of packaged foods. The multiobjective optimization approach used in this study is based on the optimization of well-known aggregating functions by an adaptive random search algorithm. The applicability of the proposed approach was illustrated by solving widely used multiobjective test problems taken from the literature. The numerical results obtained for the multiobjective test problems and for the thermal processing problem show that the proposed approach can be effectively used for solving multiobjective optimization problems arising in the food engineering field.

Process for thermal imaging scanning of a swaged heater for an anode subassembly of a hollow cathode assembly

NASA Technical Reports Server (NTRS)

Patterson, Michael J. (Inventor); Verhey, Timothy R. R. (Inventor); Soulas, George C. (Inventor)

2004-01-01

A process for thermal imaging scanning of a swaged heater of an anode subassembly of a hollow cathode assembly, comprising scanning a swaged heater with a thermal imaging radiometer to measure a temperature distribution of the heater; raising the current in a power supply to increase the temperature of the swaged heater; and measuring the swaged heater temperature using the radiometer, whereupon the temperature distribution along the length of the heater shall be less than plus or minus 5 degrees C.

Processing, structure, property and performance relationships for the thermal spray of the internal surface of aluminum cylinders

NASA Astrophysics Data System (ADS)

Cook, David James

The increased need for automotive weight reduction has necessitated the use of aluminum for engine blocks. Conventional aluminum alloys cannot survive the constant wear from a piston ring reciprocating on the surface. However, a wear resistant thermal spray coating can be applied on the internal surface of the cylinder bore, which has significant advantages over other available options. Thermal spray is a well-established process for depositing molten, semi-molten, or solid particles onto a substrate to form a protective coating. For this application, the two main challenges were obtaining good wear resistance, and achieving good adhesion. To design a system capable of producing a well-adhered, wear resistant coating for this high volume application it is necessary to identify the overall processing, structure, properties, and performance relationships. The results will demonstrate that very important relationships exist among particle characteristics, substrate conditions, and the properties of the final coating. However, it is the scientific studies to understand some of the process physics in these relationships that allow recognition of the critical processing conditions that need to be controlled to ensure a consistent, reliable thermal spray coating. In this investigation, it will be shown that the critical microstructural aspect of the coating that produced the required tribological properties was the presence of wuestite (FeO). It was found that by using a low carbon steel material with compressed air atomizing gas, it was possible to create an Fe/FeO structure that exhibited excellent tribological properties. This study will also show that traditional thermal spray surface preparation techniques were not ideal for this application, therefore a novel alternative approach was developed. The application of a flux to the aluminum surface prior to thermal spray promotes excellent bond strengths to non-roughened aluminum. Analysis will show that this flux strips the oxide from the aluminum and allows for chemical bonding of the NiAl coating to the aluminum via the formation of intermetallics. By developing processing, structure, property, and performance relationships for the full process, it was possible to design a complete coating process to succeed in this application. The determination of these relationships and the underlying process physics improves reliability and instills confidence in the process.

Calibrating thermal behavior of electronics

DOEpatents

Chainer, Timothy J.; Parida, Pritish R.; Schultz, Mark D.

2017-07-11

A method includes determining a relationship between indirect thermal data for a processor and a measured temperature associated with the processor, during a calibration process, obtaining the indirect thermal data for the processor during actual operation of the processor, and determining an actual significant temperature associated with the processor during the actual operation using the indirect thermal data for the processor during actual operation of the processor and the relationship.

Calibrating thermal behavior of electronics

DOEpatents

Chainer, Timothy J.; Parida, Pritish R.; Schultz, Mark D.

2016-05-31

A method includes determining a relationship between indirect thermal data for a processor and a measured temperature associated with the processor, during a calibration process, obtaining the indirect thermal data for the processor during actual operation of the processor, and determining an actual significant temperature associated with the processor during the actual operation using the indirect thermal data for the processor during actual operation of the processor and the relationship.

Calibrating thermal behavior of electronics

DOEpatents

Chainer, Timothy J.; Parida, Pritish R.; Schultz, Mark D.

2017-01-03

A method includes determining a relationship between indirect thermal data for a processor and a measured temperature associated with the processor, during a calibration process, obtaining the indirect thermal data for the processor during actual operation of the processor, and determining an actual significant temperature associated with the processor during the actual operation using the indirect thermal data for the processor during actual operation of the processor and the relationship.

Capacitor bonding techniques and reliability. [thermal cycling tests

NASA Technical Reports Server (NTRS)

Kinser, D. L.; Graff, S. M.; Allen, R. V.; Caruso, S. V.

1974-01-01

The effect of thermal cycling on the mechanical failure of bonded ceramic chip capacitors mounted on alumina substrates is studied. It is shown that differential thermal expansion is responsible for the cumulative effects which lead to delayed failure of the capacitors. Harder or higher melting solders are found to be less susceptible to thermal cycling effects, although they are more likely to fail during initial processing operations.

Calibration of High Temperature Thermal Conductivity System: New Algorithm to Measure Heat Capacity Using Flash Thermal Diffusivity in Thermoelectric Materials

NASA Technical Reports Server (NTRS)

Deb, Rahul; Snyder, Jeff G.

2005-01-01

A viewgraph presentation describing thermoelectric materials, an algorithm for heat capacity measurements and the process of flash thermal diffusivity. The contents include: 1) What are Thermoelectrics?; 2) Thermoelectric Applications; 3) Improving Thermoelectrics; 4) Research Goal; 5) Flash Thermal Diffusivity; 6) Background Effects; 7) Stainless Steel Comparison; 8) Pulse Max Integral; and 9) Graphite Comparison Algorithm.

Storage systems for solar thermal power

NASA Technical Reports Server (NTRS)

Calogeras, J. E.; Gordon, L. H.

1978-01-01

The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.

Thermal Sensitive Foils in Physics Experiments

ERIC Educational Resources Information Center

Bochnícek, Zdenek; Konecný, Pavel

2014-01-01

The paper describes a set of physics demonstration experiments where thermal sensitive foils are used for the detection of the two dimensional distribution of temperature. The method is used for the demonstration of thermal conductivity, temperature change in adiabatic processes, distribution of electromagnetic radiation in a microwave oven and…

Recombination activity of grain boundaries in high-performance multicrystalline Si during solar cell processing

NASA Astrophysics Data System (ADS)

Adamczyk, Krzysztof; Søndenâ, Rune; Stokkan, Gaute; Looney, Erin; Jensen, Mallory; Lai, Barry; Rinio, Markus; Di Sabatino, Marisa

2018-02-01

In this work, we applied internal quantum efficiency mapping to study the recombination activity of grain boundaries in High Performance Multicrystalline Silicon under different processing conditions. Wafers were divided into groups and underwent different thermal processing, consisting of phosphorus diffusion gettering and surface passivation with hydrogen rich layers. After these thermal treatments, wafers were processed into heterojunction with intrinsic thin layer solar cells. Light Beam Induced Current and Electron Backscatter Diffraction were applied to analyse the influence of thermal treatment during standard solar cell processing on different types of grain boundaries. The results show that after cell processing, most random-angle grain boundaries in the material are well passivated, but small-angle grain boundaries are not well passivated. Special cases of coincidence site lattice grain boundaries with high recombination activity are also found. Based on micro-X-ray fluorescence measurements, a change in the contamination level is suggested as the reason behind their increased activity.

Influence of Homogenization and Thermal Processing on the Gastrointestinal Fate of Bovine Milk Fat: In Vitro Digestion Study.

PubMed

Liang, Li; Qi, Ce; Wang, Xingguo; Jin, Qingzhe; McClements, David Julian

2017-12-20

Dairy lipids are an important source of energy and nutrients for infants and adults. The dimensions, aggregation state, and interfacial properties of fat globules in raw milk are changed by dairy processing operations, such as homogenization and thermal processing. These changes influence the behavior of fat globules within the human gastrointestinal tract (GIT). The gastrointestinal fate of raw milk, homogenized milk, high temperature short time (HTST) pasteurized milk, and ultrahigh temperature (UHT) pasteurized milk samples was therefore determined using a simulated GIT. The properties of particles in different regions of the GIT depended on the degree of milk processing. Homogenization increased the initial lipid digestion rate but did not influence the final digestion extent. Thermal processing of homogenized milk decreased the initial rate and final extent of lipid digestion, which was attributed to changes in interfacial structure. These results provide insights into the impact of dairy processing on the gastrointestinal fate of milk fat.

Anaerobic digestion of stillage fractions - estimation of the potential for energy recovery in bioethanol plants.

PubMed

Drosg, B; Fuchs, W; Meixner, K; Waltenberger, R; Kirchmayr, R; Braun, R; Bochmann, G

2013-01-01

Stillage processing can require more than one third of the thermal energy demand of a dry-grind bioethanol production plant. Therefore, for every stillage fraction occurring in stillage processing the potential of energy recovery by anaerobic digestion (AD) was estimated. In the case of whole stillage up to 128% of the thermal energy demand in the process can be provided, so even an energetically self-sufficient bioethanol production process is possible. For wet cake the recovery potential of thermal energy is 57%, for thin stillage 41%, for syrup 40% and for the evaporation condensate 2.5%. Specific issues for establishing AD of stillage fractions are evaluated in detail; these are high nitrogen concentrations, digestate treatment and trace element supply. If animal feed is co-produced at the bioethanol plant and digestate fractions are to be reused as process water, a sufficient quality is necessary. Most interesting stillage fractions as substrates for AD are whole stillage, thin stillage and the evaporation condensate. For these fractions process details are presented.

The effect of thermal processing on microstructure and mechanical properties in a nickel-iron alloy

NASA Astrophysics Data System (ADS)

Yang, Ling

The correlation between processing conditions, resulted microstructure and mechanical properties is of interest in the field of metallurgy for centuries. In this work, we investigated the effect of thermal processing parameters on microstructure, and key mechanical properties to turbine rotor design: tensile yield strength and crack growth resistance, for a nickel-iron based superalloy Inconel 706. The first step of the designing of experiments is to find parameter ranges for thermal processing. Physical metallurgy on superalloys was combined with finite element analysis to estimate variations in thermal histories for a large Alloy 706 forging, and the results were adopted for designing of experiments. Through the systematic study, correlation was found between the processing parameters and the microstructure. Five different types of grain boundaries were identified by optical metallography, fractography, and transmission electron microscopy, and they were found to be associated with eta precipitation at the grain boundaries. Proportions of types of boundaries, eta size, spacing and angle respect to the grain boundary were found to be dependent on processing parameters. Differences in grain interior precipitates were also identified, and correlated with processing conditions. Further, a strong correlation between microstructure and mechanical properties was identified. The grain boundary precipitates affect the time dependent crack propagation resistance, and different types of boundaries have different levels of resistance. Grain interior precipitates were correlated with tensile yield strength. It was also found that there is a strong environmental effect on time dependent crack propagation resistance, and the sensitivity to environmental damage is microstructure dependent. The microstructure with eta decorated on grain boundaries by controlled processing parameters is more resistant to environmental damage through oxygen embrittlement than material without eta phase on grain boundaries. Effort was made to explore the mechanisms of improving the time dependent crack propagation resistance through thermal processing, several mechanisms were identified in both environment dependent and environment independent category, and they were ranked based on their contributions in affecting crack propagation.

Thermal acclimation and thyroxine treatment modify the electric organ discharge frequency in an electric fish, Apteronotus leptorhynchus.

PubMed

Dunlap, K D; Ragazzi, M A

2015-11-01

In ectotherms, the rate of many neural processes is determined externally, by the influence of the thermal environment on body temperature, and internally, by hormones secreted from the thyroid gland. Through thermal acclimation, animals can buffer the influence of the thermal environment by adjusting their physiology to stabilize certain processes in the face of environmental temperature change. The electric organ discharge (EOD) used by weak electric fish for electrocommunication and electrolocation is highly temperature sensitive. In some temperate species that naturally experience large seasonal fluctuations in environmental temperature, the thermal sensitivity (Q10) of the EOD shifts after long-term temperature change. We examined thermal acclimation of EOD frequency in a tropical electric fish, Apteronotus leptorhynchus that naturally experiences much less temperature change. We transferred fish between thermal environments (25.3 and 27.8 °C) and measured EOD frequency and its thermal sensitivity (Q10) over 11 d. After 6d, fish exhibited thermal acclimation to both warming and cooling, adjusting the thermal dependence of EOD frequency to partially compensate for the small change (2.5 °C) in water temperature. In addition, we evaluated the thyroid influence on EOD frequency by treating fish with thyroxine or the anti-thyroid compound propylthiouricil (PTU) to stimulate or inhibit thyroid activity, respectively. Thyroxine treatment significantly increased EOD frequency, but PTU had no effect. Neither thyroxine nor PTU treatment influenced the thermal sensitivity (Q10) of EOD frequency during acute temperature change. Thus, the EOD of Apteronotus shows significant thermal acclimation and responds to elevated thyroxine. Copyright © 2015 Elsevier Inc. All rights reserved.

Onion cells after high pressure and thermal processing: comparison of membrane integrity changes using different analytical methods and impact on tissue texture.

PubMed

Gonzalez, Maria E; Anthon, Gordon E; Barrett, Diane M

2010-09-01

Two different analytical methods were evaluated for their capacity to provide quantitative information on onion cell membrane permeability and integrity after high pressure and thermal processing and to study the impact of these processing treatments on cell compartmentalization and texture quality. To determine changes in cell membrane permeability and/or integrity the methodologies utilized were: (1) measurement of a biochemical product, pyruvate, formed as a result of membrane permeabilization followed by enzymatic activity and (2) leakage of electrolytes into solution. These results were compared to previously determined methods that quantified cell viability and ¹H-NMR T(2) of onions. These methods allowed for the monitoring of changes in the plasma and tonoplast membranes after high pressure or thermal processing. High pressure treatments consisted of 5 min holding times at 50, 100, 200, 300, or 600 MPa. Thermal treatments consisted of 30 min water bath exposure to 40, 50, 60, 70, or 90 °C. There was strong agreement between the methods in the determination of the ranges of high pressure and temperature that induce changes in the integrity of the plasma and tonoplast membranes. Membrane rupture could clearly be identified at 300 MPa and above in high pressure treatments and at 60 °C and above in the thermal treatments. Membrane destabilization effects could already be visualized following the 200 MPa and 50 °C treatments. The texture of onions was influenced by the state of the membranes and was abruptly modified once membrane integrity was lost. In this study, we used chemical, biochemical, and histological techniques to obtain information on cell membrane permeability and onion tissue integrity after high pressure and thermal processing. Because there was strong agreement between the various methods used, it is possible to implement something relatively simple, such as ion leakage, into routine quality assurance measurements to determine the severity of preservation methods and the shelf life of processed vegetables.

Analysis of different thermal processing methods of foodstuffs to optimize protein, calcium, and phosphorus content for dialysis patients.

PubMed

Vrdoljak, Ivica; Panjkota Krbavčić, Ines; Bituh, Martina; Vrdoljak, Tea; Dujmić, Zoran

2015-05-01

To analyze how different thermal processing methods affect the protein, calcium, and phosphorus content of hospital food served to dialysis patients and to generate recommendations for preparing menus that optimize nutritional content while minimizing the risk of hyperphosphatemia. Standard Official Methods of Analysis (AOAC) methods were used to determine dry matter, protein, calcium, and phosphorus content in potatoes, fresh and frozen carrots, frozen green beans, chicken, beef and pork, frozen hake, pasta, and rice. These levels were determined both before and after boiling in water, steaming, stewing in oil or water, or roasting. Most of the thermal processing methods did not significantly reduce protein content. Boiling increased calcium content in all foodstuffs because of calcium absorption from the hard water. In contrast, stewing in oil containing a small amount of water decreased the calcium content of vegetables by 8% to 35% and of chicken meat by 12% to 40% on a dry weight basis. Some types of thermal processing significantly reduced the phosphorus content of the various foodstuffs, with levels decreasing by 27% to 43% for fresh and frozen vegetables, 10% to 49% for meat, 7% for pasta, and 22.8% for rice on a dry weight basis. On the basis of these results, we modified the thermal processing methods used to prepare a standard hospital menu for dialysis patients. Foodstuffs prepared according to the optimized menu were similar in protein content, higher in calcium, and significantly lower in phosphorus than foodstuffs prepared according to the standard menu. Boiling in water and stewing in oil containing some water significantly reduced phosphorus content without affecting protein content. Soaking meat in cold water for 1 h before thermal processing reduced phosphorus content even more. These results may help optimize the design of menus for dialysis patients. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Thermal Control Technologies for Complex Spacecraft

NASA Technical Reports Server (NTRS)

Swanson, Theodore D.

2004-01-01

Thermal control is a generic need for all spacecraft. In response to ever more demanding science and exploration requirements, spacecraft are becoming ever more complex, and hence their thermal control systems must evolve. This paper briefly discusses the process of technology development, the state-of-the-art in thermal control, recent experiences with on-orbit two-phase systems, and the emerging thermal control technologies to meet these evolving needs. Some "lessons learned" based on experience with on-orbit systems are also presented.

Improving the thermal efficiency of a jaggery production module using a fire-tube heat exchanger.

PubMed

La Madrid, Raul; Orbegoso, Elder Mendoza; Saavedra, Rafael; Marcelo, Daniel

2017-12-15

Jaggery is a product obtained after heating and evaporation processes have been applied to sugar cane juice via the addition of thermal energy, followed by the crystallisation process through mechanical agitation. At present, jaggery production uses furnaces and pans that are designed empirically based on trial and error procedures, which results in low ranges of thermal efficiency operation. To rectify these deficiencies, this study proposes the use of fire-tube pans to increase heat transfer from the flue gases to the sugar cane juice. With the aim of increasing the thermal efficiency of a jaggery installation, a computational fluid dynamic (CFD)-based model was used as a numerical tool to design a fire-tube pan that would replace the existing finned flat pan. For this purpose, the original configuration of the jaggery furnace was simulated via a pre-validated CFD model in order to calculate its current thermal performance. Then, the newly-designed fire-tube pan was virtually replaced in the jaggery furnace with the aim of numerically estimating the thermal performance at the same operating conditions. A comparison of both simulations highlighted the growth of the heat transfer rate at around 105% in the heating/evaporation processes when the fire-tube pan replaced the original finned flat pan. This enhancement impacted the jaggery production installation, whereby the thermal efficiency of the installation increased from 31.4% to 42.8%. Copyright © 2017 Elsevier Ltd. All rights reserved.

Coupled electro-thermal field in a high current electrolysis cell or liquid metal batteries

PubMed Central

Cai, Liwei; Ni, Haiou; Lu, Gui-Min; Yu, Jian-Guo

2018-01-01

Coupled electro-thermal field exists widely in chemical batteries and electrolysis industry. In this study, a three-dimensional numerical model, which is based on the finite-element software ANSYS, has been built to simulate the electro-thermal field in a magnesium electrolysis cell. The adjustment of the relative position of the anode and cathode can change the energy consumption of the magnesium electrolysis process significantly. Besides, the current intensity has a nonlinear effect on heat balance, and the effects of heat transfer coefficients, electrolysis and air temperature on the heat balance have been released to maintain the thermal stability in a magnesium electrolysis cell. The relationship between structure as well as process parameters and electro-thermal field has been obtained and the simulation results can provide experience for the scale-up design in liquid metal batteries. PMID:29515848

Heat and mass transfer models to understand the drying mechanisms of a porous substrate.

PubMed

Songok, Joel; Bousfield, Douglas W; Gane, Patrick A C; Toivakka, Martti

2016-02-01

While drying of paper and paper coatings is expensive, with significant energy requirements, the rate controlling mechanisms are not currently fully understood. Two two-dimensional models are used as a first approximation to predict the heat transfer during hot air drying and to evaluate the role of various parameters on the drying rates of porous coatings. The models help determine the structural limiting factors during the drying process, while applying for the first time the recently known values of coating thermal diffusivity. The results indicate that the thermal conductivity of the coating structure is not the controlling factor, but the drying rate is rather determined by the thermal transfer process at the structure surface. This underlines the need for ensuring an efficient thermal transfer from hot air to coating surface during drying, before considering further measures to increase the thermal conductivity of porous coatings.

Integrated Modeling Activities for the James Webb Space Telescope: Structural-Thermal-Optical Analysis

NASA Technical Reports Server (NTRS)

Johnston, John D.; Howard, Joseph M.; Mosier, Gary E.; Parrish, Keith A.; McGinnis, Mark A.; Bluth, Marcel; Kim, Kevin; Ha, Kong Q.

2004-01-01

The James Web Space Telescope (JWST) is a large, infrared-optimized space telescope scheduled for launch in 2011. This is a continuation of a series of papers on modeling activities for JWST. The structural-thermal-optical, often referred to as STOP, analysis process is used to predict the effect of thermal distortion on optical performance. The benchmark STOP analysis for JWST assesses the effect of an observatory slew on wavefront error. Temperatures predicted using geometric and thermal math models are mapped to a structural finite element model in order to predict thermally induced deformations. Motions and deformations at optical surfaces are then input to optical models, and optical performance is predicted using either an optical ray trace or a linear optical analysis tool. In addition to baseline performance predictions, a process for performing sensitivity studies to assess modeling uncertainties is described.

Thermally induced processes in mixtures of aluminum with organic acids after plastic deformations under high pressure

NASA Astrophysics Data System (ADS)

Zhorin, V. A.; Kiselev, M. R.; Roldugin, V. I.

2017-11-01

DSC is used to measure the thermal effects of processes in mixtures of solid organic dibasic acids with powdered aluminum, subjected to plastic deformation under pressures in the range of 0.5-4.0 GPa using an anvil-type high-pressure setup. Analysis of thermograms obtained for the samples after plastic deformation suggests a correlation between the exothermal peaks observed around the temperatures of degradation of the acids and the thermally induced chemical reactions between products of acid degradation and freshly formed surfaces of aluminum particles. The release of heat in the mixtures begins at 30-40°C. The thermal effects in the mixtures of different acids change according to the order of acid reactivity in solutions. The extreme baric dependences of enthalpies of thermal effects are associated with the rearrangement of the electron subsystem of aluminum upon plastic deformation at high pressures.

Influence of residual thermal stresses and geometric parameters on stress and electric fields in multilayer ceramic capacitors under electric bias

NASA Astrophysics Data System (ADS)

Jiang, Wu-Gui; Feng, Xi-Qiao; Nan, Ce-Wen

2008-07-01

The stress and electric fields in multilayer ceramic capacitors (MLCCs) under an applied electric bias were investigated by using a three-dimensional finite element model of ferroelectric ceramics. A coupled thermal-mechanical analysis was first made to calculate the residual thermal stress induced by the sintering process, and then a coupled electrical-mechanical analysis was performed to predict the total stress distribution in the MLCCs under a representative applied electric bias. The effects of the number of dielectric layers, the single layer thickness as well as the residual thermal stresses on the total stresses were all examined. The numerical results show that the residual thermal stress induced by the sintering process has a significant influence on the contribution of the total stresses and, therefore, should be taken into account in the design and evaluation of MLCC devices.

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

Barasinski, Anaies; Leygue, Adrien; Poitou, Arnaud

The thermoplastic tape placement process offers the possibility of manufacturing large laminated composite parts with all kinds of geometries (double curved i.e.). This process is based on the fusion bonding of a thermoplastic tape on a substrate. It has received a growing interest during last years because of its non autoclave abilities.In order to control and optimize the quality of the manufactured part, we need to predict the temperature field throughout the processing of the laminate. In this work, we focus on a thermal modeling of this process which takes in account the imperfect bonding existing between the different layersmore » of the substrate by introducing thermal contact resistance in the model. This study is leaning on experimental results which inform us that the value of the thermal resistance evolves with temperature and pressure applied on the material.« less

The pyroelectric behavior of lead free ferroelectric ceramics in thermally stimulated depolarization current measurements

NASA Astrophysics Data System (ADS)

González-Abreu, Y.; Peláiz-Barranco, A.; Garcia-Wong, A. C.; Guerra, J. D. S.

2012-06-01

The present paper shows a detailed analysis on the thermally stimulated processes in barium modified SrBi2Nb2O9 ferroelectric bi-layered perovskite, which is one of the most promising candidates for non-volatile random access memory applications because of its excellent fatigue-resistant properties. A numerical method is used to separate the real pyroelectric current from the other thermally stimulated processes. A discharge due to the space-charge injected during the poling process, the pyroelectric response, and a conductive process are discussed in a wide temperature range from ferroelectric to paraelectric phase. The pyroelectric response is separated from the other components to evaluate the polarization behavior and some pyroelectric parameters. The remanent polarization, the pyroelectric coefficient, and the merit figure are evaluated, which show good results.

Low-temperature volume radiation annealing of cold-worked bands of Al-Li-Cu-Mg alloy by 20-40 keV Ar+ ion

NASA Astrophysics Data System (ADS)

Ovchinnikov, V. V.; Gushchina, N. V.; Mozharovsky, S. M.; Kaigorodova, L. I.

2017-01-01

The processes of radiation-dynamic nature (in contrast to the thermally-activated processes) in the course of short-term irradiation of 1 mm thick bands of cold-worked aluminum alloy 1441 (of system Al-Li-Cu-Mg) with Ar+ 20-40 keV were studied. An effect of in-the-bulk (throughout the whole of metal bands thickness) low-temperature radiation annealing of the named alloy, multiply accelerated as compared with common thermal annealing processes was registered (with projected ranges of ions of considered energies definitely not exceeding 0.1 μm). The processes of recrystallization and intermetallic structure changes (occurring within a few seconds of Ar+ irradiation) have the common features as well as the differences in comparison with the results of two hour standard thermal annealing.

Innovative Approach for High Strength, High Thermal Conductive Composite Materials: Data Base

DTIC Science & Technology

2013-11-01

pitch fiber types, from which we were able to down select K6356U pitch fiber with balanced TC and strength properties. A prepreg processing line was...Creating a robust prepreg processing line to infuse unidirectional pitch fiber tape that can be used with other fibers…Pan-based carbon or glass...pitch fiber composites • Compression molding process outperforms autoclaving in mechanical and thermal properties using the same prepreg material and

SPS Energy Conversion Power Management Workshop

NASA Technical Reports Server (NTRS)

1980-01-01

Energy technology concerning photovoltaic conversion, solar thermal conversion systems, and electrical power distribution processing is discussed. The manufacturing processes involving solar cells and solar array production are summarized. Resource issues concerning gallium arsenides and silicon alternatives are reported. Collector structures for solar construction are described and estimates in their service life, failure rates, and capabilities are presented. Theories of advanced thermal power cycles are summarized. Power distribution system configurations and processing components are presented.

Experimental investigation of thermal processes in the multi-ring Couette system with counter rotation of cylinders

NASA Astrophysics Data System (ADS)

Mamonov, V. N.; Nazarov, A. D.; Serov, A. F.; Terekhov, V. I.

2016-01-01

The effect of parameters of the multi-ring Couette system with counter rotating coaxial cylinders on the process of thermal energy release in a viscous liquid filling this system is considered with regard to the problem of determining the possibility of creating the high-performance wind heat generator. The multi-cylinder rotor design allows directly conversion of the mechanical power of a device consisting of two "rotor" wind turbines with a common axis normal to the air flow into the thermal energy in a wide range of rotational speed of the cylinders. Experimental results on the measurement of thermal power released in the pilot heat generator at different relative angular speeds of cylinder rotation are presented.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Joel Smith prepares an area on the orbiter Discovery for blanket installation. The blankets are part of the Orbiter Thermal Protection System, thermal shields to protect against temperatures as high as 3,000° Fahrenheit, which are produced during descent for landing. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

NASA Image and Video Library

2003-12-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Joel Smith prepares an area on the orbiter Discovery for blanket installation. The blankets are part of the Orbiter Thermal Protection System, thermal shields to protect against temperatures as high as 3,000° Fahrenheit, which are produced during descent for landing. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Nadine Phillips prepares an area on the orbiter Discovery for blanket installation. The blankets are part of the Orbiter Thermal Protection System, thermal shields to protect against temperatures as high as 3,000° Fahrenheit, which are produced during descent for landing. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

NASA Image and Video Library

2003-12-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Nadine Phillips prepares an area on the orbiter Discovery for blanket installation. The blankets are part of the Orbiter Thermal Protection System, thermal shields to protect against temperatures as high as 3,000° Fahrenheit, which are produced during descent for landing. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

Power processing and control requirements of dispersed solar thermal electric generation systems

NASA Technical Reports Server (NTRS)

Das, R. L.

1980-01-01

Power Processing and Control requirements of Dispersed Receiver Solar Thermal Electric Generation Systems are presented. Kinematic Stirling Engines, Brayton Engines and Rankine Engines are considered as prime movers. Various types of generators are considered for ac and dc link generations. It is found that ac-ac Power Conversion is not suitable for implementation at this time. It is also found that ac-dc-ac Power Conversion with a large central inverter is more efficient than ac-dc-ac Power Conversion using small dispersed inverters. Ac-link solar thermal electric plants face potential stability and synchronization problems. Research and development efforts are needed in improving component performance characteristics and generation efficiency to make Solar Thermal Electric Generation economically attractive.

Effective Identification on Adulteration of Polyethylene With Post-consumer Ones

NASA Astrophysics Data System (ADS)

Zhao, S.; Qin, W. B.; Guo, J. F.; Liu, J.; Wang, Y. L.; Zhang, W.; Zhao, X. Y.; Wang, L.

2018-05-01

This paper mainly describes the effective identification of the adulteration of polyethylene with post-consumer ones. Degradation would be happened when multiple processings occurred. The melt flow index (MFI) analysis, thermal gravimetric analysis (TGA), differential scanning calorimeter (DSC) were used to characterize the processability and thermal stabilities of virgin polyethylene and recycled polyethylene which adulterated post-consumer PE. The results indicated that MFI of PE increased with the increasing doping content. Adulterating reclaimed PE had effects on the thermal stability of PE, which led to lower thermal decomposition temperature. Melting peak of recycled LLDPE varied from merely single to double, which differently compared differently with virgin LLDPE. Besides, with the doping content of post-consumer LDPE, the melting temperature had a decreasing tendency.

Magnetic Reconnection Driven by Thermonuclear Burning

NASA Astrophysics Data System (ADS)

Gatto, R.; Coppi, B.

2017-10-01

Considering that fusion reaction products (e.g. α-particles) deposit their energy on the electrons, the relevant thermal energy balance equation is characterized by a fusion source term, a relatively large longitudinal thermal conductivity and an appropriate transverse thermal conductivity. Then, looking for modes that are radially localized around rational surfaces, reconnected field configurations are found that can be sustained by the electron thermal energy source due to fusion reactions. Then this process can be included in the category of endogenous reconnection processes and may be viewed as a form of the thermonuclear instability that can develop in an ignited inhomogeneous plasma. A complete analysis of the equations supporting the relevant theory is reported. Sponsored in part by the U.S. DoE.

Combustion process science and technology

NASA Technical Reports Server (NTRS)

Hale, Robert R.

1989-01-01

An important and substantial area of technical work in which noncontact temperature measurement (NCTM) is desired is that involving combustion process research. In the planning for this workshop, it was hoped that W. Serignano would provide a briefing regarding the experimental requirements for thermal measurements to support such research. The particular features of thermal measurement requirements included those describing the timeline for combustion experiments, the requirements for thermal control and diagnostics of temperature and other related thermal measurements and the criticality to the involved science to parametric features of measurement capability including precision, repeatability, stability, and resolution. In addition, it was hoped that definitions could be provided which characterize the needs for concurrent imaging as it relates to science observations during the conduct of experimentation.

Thermal properties of the Cobourg Limestone

NASA Astrophysics Data System (ADS)

Pitts, Michelle

The underground storage of used nuclear fuel in Deep Geologic Repositories (DGRs) has been a subject of research in Canada for decades. One important technical aspect of repository design is the accommodation of the mechanical impacts of thermal inputs (heating) from the fuel as it goes through the remainder of its life cycle. Placement room spacing, a major factor in project cost, will be determined by the ability of the host rock to dissipate heat. The thermal conductivity and linear thermal expansion will determine the evolution of the temperature and thermally-induced stress fields. Thermal processes must be well understood to design a successful DGR. This thesis examines the thermal properties of rocks, how they are influenced by factors such as temperature, pressure, mineralogy, porosity, and saturation; and common methods for calculating and/or measuring these properties. A brief overview of thermal and thermally-coupled processes in the context of DGRs demonstrates the degree to which they would impact design, construction, and operation of these critical structures. Several case histories of major in situ heating experiments are reviewed to determine how the lessons learned could be applied to a Canadian Underground Demonstration Facility (UDF). A mineralogy investigation using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) examines samples of the Cobourg Limestone from the Bowmanville and Bruce sites, and demonstrates geographical variability within the Cobourg Formation. The thermal properties of samples from the Bowmanville site are determined. A divided bar apparatus was constructed and used to measure thermal conductivity. The temperature measurement component of the divided bar apparatus was used to measure linear thermal expansion. Finally, the past investigations into the thermal impact of a DGR are reviewed, and the implications of the laboratory testing results on similar analyses are discussed.

Solar-thermal complex sample processing for nucleic acid based diagnostics in limited resource settings

PubMed Central

Gumus, Abdurrahman; Ahsan, Syed; Dogan, Belgin; Jiang, Li; Snodgrass, Ryan; Gardner, Andrea; Lu, Zhengda; Simpson, Kenneth; Erickson, David

2016-01-01

The use of point-of-care (POC) devices in limited resource settings where access to commonly used infrastructure, such as water and electricity, can be restricted represents simultaneously one of the best application fits for POC systems as well as one of the most challenging places to deploy them. Of the many challenges involved in these systems, the preparation and processing of complex samples like stool, vomit, and biopsies are particularly difficult due to the high number and varied nature of mechanical and chemical interferents present in the sample. Previously we have demonstrated the ability to use solar-thermal energy to perform PCR based nucleic acid amplifications. In this work demonstrate how the technique, using similar infrastructure, can also be used to perform solar-thermal based sample processing system for extracting and isolating Vibrio Cholerae nucleic acids from fecal samples. The use of opto-thermal energy enables the use of sunlight to drive thermal lysing reactions in large volumes without the need for external electrical power. Using the system demonstrate the ability to reach a 95°C threshold in less than 5 minutes and maintain a stable sample temperature of +/− 2°C following the ramp up. The system is demonstrated to provide linear results between 104 and 108 CFU/mL when the released nucleic acids were quantified via traditional means. Additionally, we couple the sample processing unit with our previously demonstrated solar-thermal PCR and tablet based detection system to demonstrate very low power sample-in-answer-out detection. PMID:27231636

Task 4 supporting technology. Part 2: Detailed test plan for thermal seals. Thermal seals evaluation, improvement and test. CAN8-1, Reusable Launch Vehicle (RLV), advanced technology demonstrator: X-33. Leading edge and seals thermal protection system technology demonstration

NASA Technical Reports Server (NTRS)

Hogenson, P. A.; Lu, Tina

1995-01-01

The objective is to develop the advanced thermal seals to a technology readiness level (TRL) of 6 to support the rapid turnaround time and low maintenance requirements of the X-33 and the future reusable launch vehicle (RLV). This program is divided into three subtasks: (1) orbiter thermal seals operation history review; (2) material, process, and design improvement; and (3) fabrication and evaluation of the advanced thermal seals.

Stabilized thermally beneficiated low rank coal and method of manufacture

DOEpatents

Viall, A.J.; Richards, J.M.

1999-01-26

A process is described for reducing the spontaneous combustion tendencies of thermally beneficiated low rank coals employing heat, air or an oxygen containing gas followed by an optional moisture addition. Specific reaction conditions are supplied along with knowledge of equipment types that may be employed on a commercial scale to complete the process. 3 figs.

21 CFR 108.35 - Thermal processing of low-acid foods packaged in hermetically sealed containers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... authorized employee of the Food and Drug Administration to inspect the commercial processor's manufacturing... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Thermal processing of low-acid foods packaged in hermetically sealed containers. 108.35 Section 108.35 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...

Thermal inactivation of Salmonella and E.coli 0157:H7 on Roma tomato stem scars using high-intensity infrared laser light

USDA-ARS?s Scientific Manuscript database

Foodborne illness associated with contaminated produce is a continuing concern. Compared to the skin surface, stem scar areas of intact fruits and vegetables harbor more bacteria and are more resistant to chemical sanitizing processes. This study evaluated a precision thermal kill process which uses...

Temperature Field Simulation of Powder Sintering Process with ANSYS

NASA Astrophysics Data System (ADS)

He, Hongxiu; Wang, Jun; Li, Shuting; Chen, Zhilong; Sun, Jinfeng; You, Ying

2018-03-01

Aiming at the “spheroidization phenomenon” in the laser sintering of metal powder and other quality problems of the forming parts due to the thermal effect, the finite element model of the three-dimensional transient metal powder was established by using the atomized iron powder as the research object. The simulation of the mobile heat source was realized by means of parametric design. The distribution of the temperature field during the sintering process under different laser power and different spot sizes was simulated by ANSYS software under the condition of fully considering the influence of heat conduction, thermal convection, thermal radiation and thermophysical parameters. The influence of these factors on the actual sintering process was also analyzed, which provides an effective way for forming quality control.

Preliminary investigation of biological resistance, water absorption and swelling of thermally compressed pine wood panels

Treesearch

Oner Unsal; S. Nami Kartal; Zeki Candan; Rachel Arango; Carol A. Clausen; Frederick Green

2008-01-01

Wood can be modified by compressive, thermal and chemical treatments. Compression of wood under thermal conditions is resulted in densification of wood. This study evaluated decay and termite resistance of thermally compressed pine wood panels at either 5 or 7 MPa and at either 120 or 150°C for one hour. The process caused increases in density and decreases in...

An intermediate-scale model for thermal hydrology in low-relief permafrost-affected landscapes

DOE PAGES

Jan, Ahmad; Coon, Ethan T.; Painter, Scott L.; ...

2017-07-10

Integrated surface/subsurface models for simulating the thermal hydrology of permafrost-affected regions in a warming climate have recently become available, but computational demands of those new process-rich simu- lation tools have thus far limited their applications to one-dimensional or small two-dimensional simulations. We present a mixed-dimensional model structure for efficiently simulating surface/subsurface thermal hydrology in low-relief permafrost regions at watershed scales. The approach replaces a full three-dimensional system with a two-dimensional overland thermal hydrology system and a family of one-dimensional vertical columns, where each column represents a fully coupled surface/subsurface thermal hydrology system without lateral flow. The system is then operatormore » split, sequentially updating the overland flow system without sources and the one-dimensional columns without lateral flows. We show that the app- roach is highly scalable, supports subcycling of different processes, and compares well with the corresponding fully three-dimensional representation at significantly less computational cost. Those advances enable recently developed representations of freezing soil physics to be coupled with thermal overland flow and surface energy balance at scales of 100s of meters. Furthermore developed and demonstrated for permafrost thermal hydrology, the mixed-dimensional model structure is applicable to integrated surface/subsurface thermal hydrology in general.« less

Numerical Simulation of Non-Thermal Food Preservation

NASA Astrophysics Data System (ADS)

Rauh, C.; Krauss, J.; Ertunc, Ö.; Delgado, a.

2010-09-01

Food preservation is an important process step in food technology regarding product safety and product quality. Novel preservation techniques are currently developed, that aim at improved sensory and nutritional value but comparable safety than in conventional thermal preservation techniques. These novel non-thermal food preservation techniques are based for example on high pressures up to one GPa or pulsed electric fields. in literature studies the high potential of high pressures (HP) and of pulsed electric fields (PEF) is shown due to their high retention of valuable food components as vitamins and flavour and selective inactivation of spoiling enzymes and microorganisms. for the design of preservation processes based on the non-thermal techniques it is crucial to predict the effect of high pressure and pulsed electric fields on the food components and on the spoiling enzymes and microorganisms locally and time-dependent in the treated product. Homogenous process conditions (especially of temperature fields in HP and PEF processing and of electric fields in PEF) are aimed at to avoid the need of over-processing and the connected quality loss and to minimize safety risks due to under-processing. the present contribution presents numerical simulations of thermofluiddynamical phenomena inside of high pressure autoclaves and pulsed electric field treatment chambers. in PEF processing additionally the electric fields are considered. Implementing kinetics of occurring (bio-) chemical reactions in the numerical simulations of the temperature, flow and electric fields enables the evaluation of the process homogeneity and efficiency connected to different process parameters of the preservation techniques. Suggestions to achieve safe and high quality products are concluded out of the numerical results.

Chemistry of spring and well waters on Kilauea Volcano, Hawaii, and vicinity

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

Janik, C.J.; Nathenson, M.; Scholl, M.A.

1994-12-31

Published and new data for chemical and isotopic samples from wells and springs on Kilauea Volcano and vicinity are presented. These data are used to understand processes that determine the chemistry of dilute meteoric water, mixtures with sea water, and thermal water. Data for well and spring samples of non-thermal water indicate that mixing with sea water and dissolution of rock from weathering are the major processes that determine the composition of dissolved constituents in water. Data from coastal springs demonstrate that there is a large thermal system south of the lower east rift of Kilauea. Samples of thermal watermore » from shallow wells in the lower east rift and vicinity have rather variable chemistry indicating that a number of processes operate in the near surface. Water sampled from the available deep wells is different in composition from the shallow thermal water, indicating that generally there is not a significant component of deep water in the shallow wells. Data for samples from available deep wells show significant gradients in chemistry and steam content of the reservoir fluid. These gradients are interpreted to indicate that the reservoir tapped by the existing wells is an evolving vapor-dominated system.« less

Two-phase nanofluid-based thermal management systems for LED cooling

NASA Astrophysics Data System (ADS)

Kiseev, V.; Aminev, D.; Sazhin, O.

2017-04-01

This research focuses on two-phase thermal control systems, namely loop thermosyphons (LTS) filled with nanofluids, and their use as LED cooling devices. The behavior of the fluid in the thermosyphons and the mechanisms explaining the possible impact of nanoparticles on thermal properties of the working fluid as well as the processes in the LTS are addressed. Nanoparticle distribution in the nanofluid, methods of preparation of nanofluids and nanofluid degradation processes (aging) are studied. The results are obtained from a set of experiments on thermosyphon characteristics depending on the thermophysical properties of the working fluid, filling volume, geometry and materials of radiators. The impact of nanofluids on heat-transfer process occurring inside thermosyphon is also studied. Results indicate strong influence of nanoparticles on the thermal properties of the thermosyphons, with up to 20% increase of the heat transfer coefficient. Additionally, a method of calculating the hydrodynamic limit of the LTS is proposed, which allows for estimation of the maximum heat flux that can be transferred by means of the LTS. Possible ways for further improvement of the model are proposed. The nanofluids are shown to be effective means of enhancing two-phase systems of thermal management.

Streamline three-dimensional thermal model of a lithium titanate pouch cell battery in extreme temperature conditions with module simulation

NASA Astrophysics Data System (ADS)

Jaguemont, Joris; Omar, Noshin; Martel, François; Van den Bossche, Peter; Van Mierlo, Joeri

2017-11-01

In this paper, the development of a three-dimensional (3D) lithium titanium oxide (LTO) pouch cell is presented to first better comprehend its thermal behavior within electrified vehicle applications, but also to propose a strong modeling base for future thermal management system. Current 3D-thermal models are based on electrochemical reactions which are in need for elaborated meshing effort and long computational time. There lacks a fast electro-thermal model which can capture voltage, current and thermal distribution variation during the whole process. The proposed thermal model is a reduce-effort temperature simulation approach involving a 0D-electrical model accommodating a 3D-thermal model to exclude electrochemical processes. The thermal model is based on heat-transfer theory and its temperature distribution prediction incorporates internal conduction and heat generation effect as well as convection. In addition, experimental tests are conducted to validate the model. Results show that both the heat dissipation rate and surface temperature uniformity data are in agreement with simulation results, which satisfies the application requirements for electrified vehicles. Additionally, a LTO battery pack sizing and modeling is also designed, applied and displays a non-uniformity of the cells under driving operation. Ultimately, the model will serve as a basis for the future development of a thermal strategy for LTO cells that operate in a large temperature range, which is a strong contribution to the existing body of scientific literature.

Hybrid 3D printing by bridging micro/nano processes

NASA Astrophysics Data System (ADS)

Yoon, Hae-Sung; Jang, Ki-Hwan; Kim, Eunseob; Lee, Hyun-Taek; Ahn, Sung-Hoon

2017-06-01

A hybrid 3D printing process was developed for multiple-material/freeform nano-scale manufacturing. The process consisted of aerodynamically focused nanoparticle (AFN) printing, micro-machining, focused ion beam milling, and spin-coating. Theoretical and experimental investigations were carried out to improve the compatibility of each of the processes, enabling bridging of various different techniques. The resulting hybrid process could address the limitations of individual processes, enabling improved process scaling and dimensional degrees of freedom, without losing the advantages of the existing processes. The minimum structure width can be reduced to 50 nm using undercut structures. In addition, AFN printing employs particle impact for adhesion, and various inorganic materials are suitable for printing, including metals and functional ceramics. Using the developed system, we fabricated bi-material cantilevers for applications as a thermal actuator. The mechanical and thermal properties of the structure were investigated using an in situ measurement system, and irregular thermal phenomena due to the fabrication process were analyzed. We expect that this work will lead to improvements in the area of customized nano-scale manufacturing, as well as further improvements in manufacturing technology by combining different fabrication techniques.

Solidification and Biotoxicity Assessment of Thermally Treated Municipal Solid Waste Incineration (MSWI) Fly Ash

PubMed Central

Gong, Bing; Deng, Yi; Yang, Yuanyi; Tan, Swee Ngin; Liu, Qianni; Yang, Weizhong

2017-01-01

In the present work, thermal treatment was used to stabilize municipal solid waste incineration (MSWI) fly ash, which was considered hazardous waste. Toxicity characteristic leaching procedure (TCLP) results indicated that, after the thermal process, the leaching concentrations of Pb, Cu, and Zn decreased from 8.08 to 0.16 mg/L, 0.12 to 0.017 mg/L and 0.39 to 0.1 mg/L, respectively, which well met the limits in GB5085.3-2007 and GB16689-2008. Thermal treatment showed a negative effect on the leachability of Cr with concentrations increasing from 0.1 to 1.28 mg/L; nevertheless, it was still under the limitations. XRD analysis suggested that, after thermal treatments, CaO was newly generated. CaO was a main contribution to higher Cr leaching concentrations owing to the formation of Cr (VI)—compounds such as CaCrO4. SEM/EDS tests revealed that particle adhesion, agglomeration, and grain growth happened during the thermal process and thus diminished the leachability of Pb, Cu, and Zn, but these processes had no significant influence on the leaching of Cr. A microbial assay demonstrated that all thermally treated samples yet possessed strong bactericidal activity according to optical density (OD) test results. Among all samples, the OD value of raw fly ash (RFA) was lowest followed by FA700-10, FA900-10, and FA1100-10 in an increasing order, which indicated that the sequence of the biotoxicity for these samples was RFA > FA700-10 > FA900-10 > FA1100-10. This preliminary study indicated that, apart from TCLP criteria, the biotoxicity assessment was indispensable for evaluating the effect of thermal treatment for MSWI fly ash. PMID:28604580

Miniaturized planar Si-nanowire micro-thermoelectric generator using exuded thermal field for power generation.

PubMed

Zhan, Tianzhuo; Yamato, Ryo; Hashimoto, Shuichiro; Tomita, Motohiro; Oba, Shunsuke; Himeda, Yuya; Mesaki, Kohei; Takezawa, Hiroki; Yokogawa, Ryo; Xu, Yibin; Matsukawa, Takashi; Ogura, Atsushi; Kamakura, Yoshinari; Watanabe, Takanobu

2018-01-01

For harvesting energy from waste heat, the power generation densities and fabrication costs of thermoelectric generators (TEGs) are considered more important than their conversion efficiency because waste heat energy is essentially obtained free of charge. In this study, we propose a miniaturized planar Si-nanowire micro-thermoelectric generator (SiNW-μTEG) architecture, which could be simply fabricated using the complementary metal-oxide-semiconductor-compatible process. Compared with the conventional nanowire μTEGs, this SiNW-μTEG features the use of an exuded thermal field for power generation. Thus, there is no need to etch away the substrate to form suspended SiNWs, which leads to a low fabrication cost and well-protected SiNWs. We experimentally demonstrate that the power generation density of the SiNW-μTEGs was enhanced by four orders of magnitude when the SiNWs were shortened from 280 to 8 μm. Furthermore, we reduced the parasitic thermal resistance, which becomes significant in the shortened SiNW-μTEGs, by optimizing the fabrication process of AlN films as a thermally conductive layer. As a result, the power generation density of the SiNW-μTEGs was enhanced by an order of magnitude for reactive sputtering as compared to non-reactive sputtering process. A power density of 27.9 nW/cm 2 has been achieved. By measuring the thermal conductivities of the two AlN films, we found that the reduction in the parasitic thermal resistance was caused by an increase in the thermal conductivity of the AlN film and a decrease in the thermal boundary resistance.

Miniaturized planar Si-nanowire micro-thermoelectric generator using exuded thermal field for power generation

PubMed Central

Zhan, Tianzhuo; Yamato, Ryo; Hashimoto, Shuichiro; Tomita, Motohiro; Oba, Shunsuke; Himeda, Yuya; Mesaki, Kohei; Takezawa, Hiroki; Yokogawa, Ryo; Xu, Yibin; Matsukawa, Takashi; Ogura, Atsushi; Kamakura, Yoshinari; Watanabe, Takanobu

2018-01-01

Abstract For harvesting energy from waste heat, the power generation densities and fabrication costs of thermoelectric generators (TEGs) are considered more important than their conversion efficiency because waste heat energy is essentially obtained free of charge. In this study, we propose a miniaturized planar Si-nanowire micro-thermoelectric generator (SiNW-μTEG) architecture, which could be simply fabricated using the complementary metal–oxide–semiconductor–compatible process. Compared with the conventional nanowire μTEGs, this SiNW-μTEG features the use of an exuded thermal field for power generation. Thus, there is no need to etch away the substrate to form suspended SiNWs, which leads to a low fabrication cost and well-protected SiNWs. We experimentally demonstrate that the power generation density of the SiNW-μTEGs was enhanced by four orders of magnitude when the SiNWs were shortened from 280 to 8 μm. Furthermore, we reduced the parasitic thermal resistance, which becomes significant in the shortened SiNW-μTEGs, by optimizing the fabrication process of AlN films as a thermally conductive layer. As a result, the power generation density of the SiNW-μTEGs was enhanced by an order of magnitude for reactive sputtering as compared to non-reactive sputtering process. A power density of 27.9 nW/cm2 has been achieved. By measuring the thermal conductivities of the two AlN films, we found that the reduction in the parasitic thermal resistance was caused by an increase in the thermal conductivity of the AlN film and a decrease in the thermal boundary resistance. PMID:29868148

Unique hyper-thermal composting process in Kagoshima City forms distinct bacterial community structures.

PubMed

Tashiro, Yukihiro; Tabata, Hanae; Itahara, Asuka; Shimizu, Natsuki; Tashiro, Kosuke; Sakai, Kenji

2016-11-01

A unique compost, Satsuma soil, is produced from three types of wastewater sludge using hyper-thermal processes at temperatures much higher than that of general thermophilic processes in Kagoshima City, Japan. We analyzed the bacterial community structures of this hyper-thermal compost sample and other sludges and composts by a high-throughput barcoded pyrosequencing method targeting the 16S rRNA gene. In total, 621,076 reads were derived from 17 samples and filtered. Artificial sequences were deleted and the reads were clustered based on the operational taxonomic units (OTUs) at 97% similarity. Phylum-level analysis of the hyper-thermal compost revealed drastic changes of the sludge structures (each relative abundance) from Firmicutes (average 47.8%), Proteobacteria (average 22.3%), and Bacteroidetes (average 10.1%) to two main phyla including Firmicutes (73.6%) and Actinobacteria (25.0%) with less Proteobacteria (∼0.3%) and Bacteroidetes (∼0.1%). Furthermore, we determined the predominant species (each relative abundance) of the hyper-thermal compost including Firmicutes related to Staphylococcus cohnii (13.8%), Jeotgalicoccus coquinae (8.01%), and Staphylococcus lentus (5.96%), and Actinobacteria related to Corynebacterium stationis (6.41%), and found that these species were not predominant in wastewater sludge. In contrast, we did not observe any common structures among eight other composts produced, using the hyper-thermal composts as the inoculums, under thermophilic conditions from different materials. Principle coordinate analysis of the hyper-thermal compost indicated a large difference in bacterial community structures from material sludge and other composts. These results suggested that a distinct bacterial community structure was formed by hyper-thermal composting. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Low-temperature thermal pre-treatment of municipal wastewater sludge: Process optimization and effects on solubilization and anaerobic degradation.

PubMed

Nazari, Laleh; Yuan, Zhongshun; Santoro, Domenico; Sarathy, Siva; Ho, Dang; Batstone, Damien; Xu, Chunbao Charles; Ray, Madhumita B

2017-04-15

The present study examines the relationship between the degree of solubilization and biodegradability of wastewater sludge in anaerobic digestion as a result of low-temperature thermal pre-treatment. The main effect of thermal pre-treatment is the disintegration of cell membranes and thus solubilization of organic compounds. There is an established correlation between chemical oxygen demand (COD) solubilization and temperature of thermal pre-treatment, but results of thermal pre-treatment in terms of biodegradability are not well understood. Aiming to determine the impact of low temperature treatments on biogas production, the thermal pre-treatment process was first optimized based on an experimental design study on waste activated sludge in batch mode. The optimum temperature, reaction time and pH of the process were determined to be 80 °C, 5 h and pH 10, respectively. All three factors had a strong individual effect (p < 0.001), with a significant interaction effect for temp. pH 2 (p = 0.002). Thermal pre-treatments, carried out on seven different municipal wastewater sludges at the above optimum operating conditions, produced increased COD solubilization of 18.3 ± 7.5% and VSS reduction of 27.7 ± 12.3% compared to the untreated sludges. The solubilization of proteins was significantly higher than carbohydrates. Methane produced in biochemical methane potential (BMP) tests, indicated initial higher rates (p = 0.0013) for the thermally treated samples (k hyd up to 5 times higher), although the ultimate methane yields were not significantly affected by the treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improved Thermal Cycling Durability of Thermal Barrier Coatings Manufactured by PS-PVD

NASA Astrophysics Data System (ADS)

Rezanka, S.; Mauer, G.; Vaßen, R.

2014-01-01

The plasma spray-physical vapor deposition (PS-PVD) process is a promising method to manufacture thermal barrier coatings (TBCs). It fills the gap between traditional thermal spray processes and electron beam physical vapor deposition (EB-PVD). The durability of PS-PVD manufactured columnar TBCs is strongly influenced by the compatibility of the metallic bondcoat (BC) and the ceramic TBC. Earlier investigations have shown that a smooth BC surface is beneficial for the durability during thermal cycling. Further improvements of the bonding between BC and TBC could be achieved by optimizing the formation of the thermally grown oxide (TGO) layer. In the present study, the parameters of pre-heating and deposition of the first coating layer were investigated in order to adjust the growth of the TGO. Finally, the durability of the PS-PVD coatings was improved while the main advantage of PS-PVD, i.e., much higher deposition rate in comparison to EB-PVD, could be maintained. For such coatings, improved thermal cycling lifetimes more than two times higher than conventionally sprayed TBCs, were measured in burner rigs at ~1250 °C/1050 °C surface/substrate exposure temperatures.

Impacts of microalgae pre-treatments for improved anaerobic digestion: thermal treatment, thermal hydrolysis, ultrasound and enzymatic hydrolysis.

PubMed

Ometto, Francesco; Quiroga, Gerardo; Pšenička, Pavel; Whitton, Rachel; Jefferson, Bruce; Villa, Raffaella

2014-11-15

Anaerobic digestion (AD) of microalgae is primarily inhibited by the chemical composition of their cell walls containing biopolymers able to resist bacterial degradation. Adoption of pre-treatments such as thermal, thermal hydrolysis, ultrasound and enzymatic hydrolysis have the potential to remove these inhibitory compounds and enhance biogas yields by degrading the cell wall, and releasing the intracellular algogenic organic matter (AOM). This work investigated the effect of four pre-treatments on three microalgae species, and their impact on the quantity of soluble biomass released in the media and thus on the digestion process yields. The analysis of the composition of the soluble COD released and of the TEM images of the cells showed two main degradation actions associated with the processes: (1) cell wall damage with the release of intracellular AOM (thermal, thermal hydrolysis and ultrasound) and (2) degradation of the cell wall constituents with the release of intracellular AOM and the solubilisation of the cell wall biopolymers (enzymatic hydrolysis). As a result of this, enzymatic hydrolysis showed the greatest biogas yield increments (>270%) followed by thermal hydrolysis (60-100%) and ultrasounds (30-60%). Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of High Fidelity, Fuel-Like Thermal Simulators for Non-Nuclear Testing

NASA Technical Reports Server (NTRS)

Bragg-Sitton, S. M.; Farmer, J.; Dixon, D.; Kapernick, R.; Dickens, R.; Adams, M.

2007-01-01

Non-nuclear testing can be a valuable tool in development of a space nuclear power or propulsion system. In a non-nuclear test bed, electric heaters are used to simulate the heat from nuclear fuel. Work at the NASA Marshall Space Flight Center seeks to develop high fidelity thermal simulators that not only match the static power profile that would be observed in an operating, fueled nuclear reactor, but to also match the dynamic fuel pin performance during feasible transients. Comparison between the fuel pins and thermal simulators is made at the fuel clad surface, which corresponds to the sheath surface in the thermal simulator. Static and dynamic fuel pin performance was determined using SINDA-FLUINT analysis, and the performance of conceptual thermal simulator designs was compared to the expected nuclear performance. Through a series of iterative analysis, a conceptual high fidelity design will be developed, followed by engineering design, fabrication, and testing to validate the overall design process. Although the resulting thermal simulator will be designed for a specific reactor concept, establishing this rigorous design process will assist in streamlining the thermal simulator development for other reactor concepts.

Study of the effect of gamma irradiation on a commercial polycyclooctene I. Thermal and mechanical properties

NASA Astrophysics Data System (ADS)

García-Huete, N.; Laza, J. M.; Cuevas, J. M.; Vilas, J. L.; Bilbao, E.; León, L. M.

2014-09-01

A gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical, chemical and mechanical properties. Gamma irradiation originates free radicals able to induce chain scission or recombination of radicals, which induces annihilation, branching or crosslinking processes. The aim of this work is to research the structural, thermal and mechanical changes induced on a commercial polycyclooctene (PCO) when it is irradiated with a gamma source of 60Co at different doses (25-200 kGy). After gamma irradiation, gel content was determined by Soxhlet extraction in cyclohexane. Furthermore, thermal properties were evaluated before and after Soxhlet extraction by means of Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC), as well as mechanical properties were measured by Dynamic Mechanical Thermal Analysis (DMTA). The results showed the variations of the properties depending on the irradiation dose. Finally, a first approach to evaluate qualitatively the shape memory behaviour of all irradiated PCO samples was performed by a visually monitoring shape recovery process.

SOLTECH 1992 proceedings: Solar Process Heat Program, volume 1

NASA Astrophysics Data System (ADS)

1992-03-01

This document is a limited Proceedings, documenting the presentations given at the symposia conducted by the U.S. Department of Energy's (DOE) Solar Industrial Program and Solar Thermal Electrical Program at SOLTECH92. The SOLTECH92 national solar energy conference was held in Albuquerque, New Mexico during the period February 17-20, 1992. The National Renewable Energy Laboratory manages the Solar Industrial Program; Sandia National Laboratories (Albuquerque) manages the Solar Thermal Electric Program. The symposia sessions were as follows: (1) Solar Industrial Program and Solar Thermal Electric Program Overviews, (2) Solar Process Heat Applications, (3) Solar Decontamination of Water and Soil, (4) Solar Building Technologies, (5) Solar Thermal Electric Systems, and (6) Photovoltaic (PV) Applications and Technologies. For each presentation given in these symposia, these Proceedings provide a one- to two-page abstract and copies of the viewgraphs and/or 35 mm slides utilized by the speaker. Some speakers provided additional materials in the interest of completeness. The materials presented in this document were not subjected to a peer review process.

Colour centre recovery in yttria-stabilised zirconia: photo-induced versus thermal processes

NASA Astrophysics Data System (ADS)

Costantini, Jean-Marc; Touati, Nadia; Binet, Laurent; Lelong, Gérald; Guillaumet, Maxime; Beuneu, François

2018-05-01

The photo-annealing of colour centres in yttria-stabilised zirconia (YSZ) was studied by electron paramagnetic resonance spectroscopy upon UV-ray or laser light illumination, and compared to thermal annealing. Stable hole centres (HCs) were produced in as-grown YSZ single crystals by UV-ray irradiation at room temperature (RT). The HCs produced by 200-MeV Au ion irradiation, as well as the F+-type centres (? centres involving oxygen vacancies) were left unchanged upon UV illumination. In contrast, a significant photo-annealing of the latter point defects was achieved in 1.4-MeV electron-irradiated YSZ by 553-nm laser light irradiation at RT. Almost complete photo-bleaching was achieved by laser irradiation inside the absorption band of ? centres centred at a wavelength 550 nm. Thermal annealing of these colour centres was also followed by UV-visible absorption spectroscopy showing full bleaching at 523 K. Colour-centre evolutions by photo-induced and thermally activated processes are discussed on the basis of charge exchange processes between point defects.

Predicting the Quality of Pasteurized Vegetables Using Kinetic Models: A Review

PubMed Central

Aamir, Muhammad; Ovissipour, Mahmoudreza; Sablani, Shyam S.; Rasco, Barbara

2013-01-01

A resurgence in interest examining thermal pasteurization technologies has been driven by demands for “cleaner” labeling and the need of organic and natural foods markets for suitable preventive measures to impede microbial growth and extend shelf life of minimally processed foods and ready-to-eat foods with a concomitant reduction in the use of chemical preservatives. This review describes the effects of thermal pasteurization on vegetable quality attributes including altering flavor and texture to improve consumer acceptability, stabilizing color, improving digestibility, palatability and retaining bioavailability of important nutrients, and bioactive compounds. Here, we provide kinetic parameters for inactivation of viral and bacterial pathogens and their surrogates and marker enzymes used to monitor process effectiveness in a variety of plant food items. Data on thermal processing protocols leading to higher retention and bioactivity are also presented. Thermal inactivation of foodborne viruses and pathogenic bacteria, specifically at lower pasteurization temperatures or via new technologies such as dielectric heating, can lead to greater retention of “fresh-like” properties. PMID:26904594

Site-specific investigations on aquifer thermal energy storage for space and process cooling

NASA Astrophysics Data System (ADS)

Brown, D. R.

1991-08-01

The Pacific Northwest Laboratory (PNL) has completed three preliminary site-specific feasibility studies that investigated aquifer thermal energy storage (ATES) for reducing space and process cooling costs. Chilled water stored in an ATES system could be used to meet all or part of the process and/or space cooling loads at the three facilities investigated. Seasonal or diurnal chill ATES systems could be significantly less expensive than a conventional electrically-driven, load-following chiller system at one of the three sites, depending on the cooling water loop return temperature and presumed future electricity escalation rate. For the other two sites investigated, a chill ATES system would be economically competitive with conventional chillers if onsite aquifer characteristics were improved. Well flow rates at one of the sites were adequate, but the expected thermal recovery efficiency was too low. The reverse of this situation was found at the other site, where the thermal recovery efficiency was expected to be adequate, but well flow rates were too low.

Thermodynamic analysis of a thermal storage unit under the influence of nano-particles added to the phase change material and/or the working fluid

NASA Astrophysics Data System (ADS)

Abolghasemi, Mehran; Keshavarz, Ali; Mehrabian, Mozaffar Ali

2012-11-01

The thermal storage unit consists of two concentric cylinders where the working fluid flows through the internal cylinder and the annulus is filled with a phase change material. The system carries out a cyclic operation; each cycle consists of two processes. In the charging process the hot working fluid enters the internal cylinder and transfers heat to the phase change material. In the discharging process the cold working fluid enters the internal cylinder and absorbs heat from the phase change material. The differential equations governing the heat transfer between the two media are solved numerically. The numerical results are compared with the experimental results available in the literature. The performance of an energy storage unit is directly related to the thermal conductivity of nano-particles. The energy consumption of a residential unit whose energy is supplied by a thermal storage system can be reduced by 43 % when using nano-particles.

Multifunctional PLA-PHB/cellulose nanocrystal films: processing, structural and thermal properties.

PubMed

Arrieta, M P; Fortunati, E; Dominici, F; Rayón, E; López, J; Kenny, J M

2014-07-17

Cellulose nanocrystals (CNCs) synthesized from microcrystalline cellulose by acid hydrolysis were added into poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends to improve the final properties of the multifunctional systems. CNC were also modified with a surfactant (CNCs) to increase the interfacial adhesion in the systems maintaining the thermal stability. Firstly, masterbatch pellets were obtained for each formulation to improve the dispersion of the cellulose structures in the PLA-PHB and then nanocomposite films were processed. The thermal stability as well as the morphological and structural properties of nanocomposites was investigated. While PHB increased the PLA crystallinity due to its nucleation effect, well dispersed CNC and CNCs not only increased the crystallinity but also improved the processability, the thermal stability and the interaction between both polymers especially in the case of the modified CNCs based PLA-PHB formulation. Likewise, CNCs were better dispersed in PLA-CNCs and PLA-PHB-CNCs, than CNC. Copyright © 2014 Elsevier Ltd. All rights reserved.

Process for the production of metal nitride sintered bodies and resultant silicon nitride and aluminum nitride sintered bodies

NASA Technical Reports Server (NTRS)

Yajima, S.; Omori, M.; Hayashi, J.; Kayano, H.; Hamano, M.

1983-01-01

A process for the manufacture of metal nitride sintered bodies, in particular, a process in which a mixture of metal nitrite powders is shaped and heated together with a binding agent is described. Of the metal nitrides Si3N4 and AIN were used especially frequently because of their excellent properties at high temperatures. The goal is to produce a process for metal nitride sintered bodies with high strength, high corrosion resistance, thermal shock resistance, thermal shock resistance, and avoidance of previously known faults.

Thermal effects in nano-sized adsorbate islands growth processes at vapor deposition

NASA Astrophysics Data System (ADS)

Kharchenko, Vasyl O.; Kharchenko, Dmitrii O.; Dvornichenko, Alina V.

2016-02-01

We study a model of pattern formation in adsorptive systems with a local change in the surface temperature due to adsorption/desorption processes. It is found that thermal effects shrink the domain of main system parameters, when pattern formation is possible. It is shown that an increase in a surface reheat efficiency delays ordering processes. We have found that a distribution of adsorbate islands over sizes depends on relaxation and reheat processes. We have shown that the mean linear size of stationary adsorbate islands is of nano-meter range.

Thermal sprayed composite melt containment tubular component and method of making same

DOEpatents

Besser, Matthew F.; Terpstra, Robert L.; Sordelet, Daniel J.; Anderson, Iver E.

2002-03-19

A tubular thermal sprayed melt containment component for transient containment of molten metal or alloy wherein the tubular member includes a thermal sprayed inner melt-contacting layer for contacting molten metal or alloy to be processed, a thermal sprayed heat-generating layer deposited on the inner layer, and an optional thermal sprayed outer thermal insulating layer. The thermal sprayed heat-generating layer is inductively heated as a susceptor of an induction field or electrical resistively heated by passing electrical current therethrough. The tubular thermal sprayed melt containment component can comprise an elongated melt pour tube of a gas atomization apparatus where the melt pour tube supplies molten material from a crucible to an underlying melt atomization nozzle.

Engineering a new class of thermal spray nano-based microstructures from agglomerated nanostructured particles, suspensions and solutions: an invited review

NASA Astrophysics Data System (ADS)

Fauchais, P.; Montavon, G.; Lima, R. S.; Marple, B. R.

2011-03-01

From the pioneering works of McPherson in 1973 who identified nanometre-sized features in thermal spray conventional alumina coatings (using sprayed particles in the tens of micrometres size range) to the most recent and most advanced work aimed at manufacturing nanostructured coatings from nanometre-sized feedstock particles, the thermal spray community has been involved with nanometre-sized features and feedstock for more than 30 years. Both the development of feedstock (especially through cryo-milling, and processes able to manufacture coatings structured at the sub-micrometre or nanometre sizes, such as micrometre-sized agglomerates made of nanometre-sized particles for feedstock) and the emergence of thermal spray processes such as suspension and liquid precursor thermal spray techniques have been driven by the need to manufacture coatings with enhanced properties. These techniques result in two different types of coatings: on the one hand, those with a so-called bimodal structure having nanometre-sized zones embedded within micrometre ones, for which the spray process is similar to that of conventional coatings and on the other hand, sub-micrometre or nanostructured coatings achieved by suspension or solution spraying. Compared with suspension spraying, solution precursor spraying uses molecularly mixed precursors as liquids, avoiding a separate processing route for the preparation of powders and enabling the synthesis of a wide range of oxide powders and coatings. Such coatings are intended for use in various applications ranging from improved thermal barrier layers and wear-resistant surfaces to thin solid electrolytes for solid oxide fuel cell systems, among other numerous applications. Meanwhile these processes are more complex to operate since they are more sensitive to parameter variations compared with conventional thermal spray processes. Progress in this area has resulted from the unique combination of modelling activities, the evolution of diagnostic tools and strategies, and experimental advances that have enabled the development of a wide range of coating structures exhibiting in numerous cases unique properties. Several examples are detailed. In this paper the following aspects are presented successively (i) the two spray techniques used for manufacturing such coatings: thermal plasma and HVOF, (ii) sensors developed for in-flight diagnostics of micrometre-sized particles and the interaction of a liquid and hot gas flow, (iii) three spray processes: conventional spraying using micrometre-sized agglomerates of nanometre-sized particles, suspension spraying and solution spraying and (iv) the emerging issues resulting from the specific structures of these materials, particularly the characterization of these coatings and (v) the potential industrial applications. Further advances require the scientific and industrial communities to undertake new research and development activities to address, understand and control the complex mechanisms occurring, in particular, thermal flow—liquid drops or stream interactions when considering suspension and liquid precursor thermal spray techniques. Work is still needed to develop new measurement devices to diagnose in-flight droplets or particles below 2 µm average diameter and to validate that the assumptions made for liquid-hot gas interactions. Efforts are also required to further develop some of the characterization protocols suitable to address the specificities of such nanostructured coatings, as some existing 'conventional' protocols usually implemented on thermal spray coatings are not suitable anymore, in particular to address the void network architectures from which numerous coatings properties are derived.

Stochastic thermodynamics for Ising chain and symmetric exclusion process.

PubMed

Toral, R; Van den Broeck, C; Escaff, D; Lindenberg, Katja

2017-03-01

We verify the finite-time fluctuation theorem for a linear Ising chain in contact with heat reservoirs at its ends. Analytic results are derived for a chain consisting of two spins. The system can be mapped onto a model for particle transport, namely, the symmetric exclusion process in contact with thermal and particle reservoirs. We modify the symmetric exclusion process to represent a thermal engine and reproduce universal features of the efficiency at maximum power.

Recapturing Graphite-Based Fuel Element Technology for Nuclear Thermal Propulsion

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

Trammell, Michael P; Jolly, Brian C; Miller, James Henry

ORNL is currently recapturing graphite based fuel forms for Nuclear Thermal Propulsion (NTP). This effort involves research and development on materials selection, extrusion, and coating processes to produce fuel elements representative of historical ROVER and NERVA fuel. Initially, lab scale specimens were fabricated using surrogate oxides to develop processing parameters that could be applied to full length NTP fuel elements. Progress toward understanding the effect of these processing parameters on surrogate fuel microstructure is presented.

Air-Lubricated Thermal Processor For Dry Silver Film

NASA Astrophysics Data System (ADS)

Siryj, B. W.

1980-09-01

Since dry silver film is processed by heat, it may be viewed on a light table only seconds after exposure. On the other hand, wet films require both bulky chemicals and substantial time before an image can be analyzed. Processing of dry silver film, although simple in concept, is not so simple when reduced to practice. The main concern is the effect of film temperature gradients on uniformity of optical film density. RCA has developed two thermal processors, different in implementation but based on the same philosophy. Pressurized air is directed to both sides of the film to support the film and to conduct the heat to the film. Porous graphite is used as the medium through which heat and air are introduced. The initial thermal processor was designed to process 9.5-inch-wide film moving at speeds ranging from 0.0034 to 0.008 inch per second. The processor configuration was curved to match the plane generated by the laser recording beam. The second thermal processor was configured to process 5-inch-wide film moving at a continuously variable rate ranging from 0.15 to 3.5 inches per second. Due to field flattening optics used in this laser recorder, the required film processing area was plane. In addition, this processor was sectioned in the direction of film motion, giving the processor the capability of varying both temperature and effective processing area.

Reduction of antiproliferative capacities, cell-based antioxidant capacities and phytochemical contents of common beans and soybeans upon thermal processing.

PubMed

Xu, Baojun; Chang, Sam K C

2011-12-01

The effects of boiling and steaming processes on the antiproliferative and cellular antioxidant properties, as well as phytochemicals, of two types of common beans (pinto and black beans) and two types of soybeans (yellow and black) were investigated. All thermal-processing methods caused significant (p<0.05) decreases in total phenolic content (TPC), total saponin content (TSC) and phytic acid content (PAC) values in all bean types (except for TPC values in pressure-steamed yellow soybeans) as compared to those of the raw beans. All types of uncooked raw beans exhibited cellular antioxidant activities (CAA) in dose-dependent manners. Black soybeans exhibited the greatest CAA, followed by black beans, pinto beans and yellow soybeans. The CAA of cooked beans were generally diminished or eliminated by thermal processing. The hydrophilic extracts from raw pinto beans, black beans and black soybeans exhibited antiproliferation capacities against human gastric (AGS) and colorectal (SW480) cancer cells in dose-dependent manners. The raw yellow soybeans exhibited dose-dependent antiproliferation activities against the SW480 cells. Most of the cooked beans lost their antiproliferation capacities as observed in the raw beans. These results indicate that different processing methods may have various effects on phytochemical profiles and bioactivities. Overall, thermal processing caused a significant reduction of the health-promotion effects of beans. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparison of Conventional and Microwave Treatment on Soymilk for Inactivation of Trypsin Inhibitors and In Vitro Protein Digestibility

PubMed Central

Vagadia, Brinda Harish; Raghavan, Vijaya

2018-01-01

Soymilk is lower in calories compared to cow’s milk, since it is derived from a plant source (no cholesterol) and is an excellent source of protein. Despite the beneficial factors, soymilk is considered as one of the most controversial foods in the world. It contains serine protease inhibitors which lower its nutritional value and digestibility. Processing techniques for the elimination of trypsin inhibitors and lipoxygenase, which have shorter processing time and lower production costs are required for the large-scale manufacturing of soymilk. In this study, the suitable conditions of time and temperature are optimized during microwave processing to obtain soymilk with maximum digestibility with inactivation of trypsin inhibitors, in comparison to the conventional thermal treatment. The microwave processing conditions at a frequency of 2.45 GHz and temperatures of 70 °C, 85 °C and 100 °C for 2, 5 and 8 min were investigated and were compared to conventional thermal treatments at the same temperature for 10, 20 and 30 min. Response surface methodology is used to design and optimize the experimental conditions. Thermal processing was able to increase digestibility by 7% (microwave) and 11% (conventional) compared to control, while trypsin inhibitor activity reduced to 1% in microwave processing and 3% in conventional thermal treatment when compared to 10% in raw soybean. PMID:29316679

Hydrogen recovery from the thermal plasma gasification of solid waste.

PubMed

Byun, Youngchul; Cho, Moohyun; Chung, Jae Woo; Namkung, Won; Lee, Hyeon Don; Jang, Sung Duk; Kim, Young-Suk; Lee, Jin-Ho; Lee, Carg-Ro; Hwang, Soon-Mo

2011-06-15

Thermal plasma gasification has been demonstrated as one of the most effective and environmentally friendly methods for solid waste treatment and energy utilization in many of studies. Therefore, the thermal plasma process of solid waste gasification (paper mill waste, 1.2 ton/day) was applied for the recovery of high purity H(2) (>99.99%). Gases emitted from a gasification furnace equipped with a nontransferred thermal plasma torch were purified using a bag-filter and wet scrubber. Thereafter, the gases, which contained syngas (CO+H(2)), were introduced into a H(2) recovery system, consisting largely of a water gas shift (WGS) unit for the conversion of CO to H(2) and a pressure swing adsorption (PSA) unit for the separation and purification of H(2). It was successfully demonstrated that the thermal plasma process of solid waste gasification, combined with the WGS and PSA, produced high purity H(2) (20 N m(3)/h (400 H(2)-Nm(3)/PMW-ton), up to 99.99%) using a plasma torch with 1.6 MWh/PMW-ton of electricity. The results presented here suggest that the thermal plasma process of solid waste gasification for the production of high purity H(2) may provide a new approach as a future energy infrastructure based on H(2). Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of tempering treatment upon the residual stress of bimetallic roll

NASA Astrophysics Data System (ADS)

Sano, Y.; Noda, N.-A.; Takase, Y.; Torigoe, R.; Tsuboi, K.; Aridi, M. R.; Sanada, Y.; Lan, L. Y.

2018-06-01

Bimetallic rolls are widely used in steel rolling industries because of the excellent hardness, wear resistance, and high temperature properties. However, thermal stress is produced by heating-cooling thermal cycles, which is a great challenge for their practical application. Indeed, if severe thermal tensile stress is introduced into these rolls, it can assist the thermal cracks to propagate, even lead to the overall failure of rolls. In this paper, we investigated the effect of tempering treatment on the residual stress after the bimetallic rolls were subjected to quenching. Compared with the non-uniform heating-quenching process, the tempering process makes the maximum stress at the core decreased by 15% (from 275 MPa to 234 MPa) with considering martensite transformation but decreased by 26% (from 275 MPa to 201 MPa) without considering martensite transformation. For tempering process after uniform heating quenching, the maximum stress at the core decreases by 24% from 357 MPa to 273 MPa with considering martensite transformation but decreases by 30% from 357 MPa to 246 MPa without considering martensite transformation. And compared with the non-uniform heating-quenching process, the double tempering process makes the maximum stress at the core decreased by 8% (from 275 MPa to 253 MPa) with considering martensite transformation but decreased by 27% (from 275 MPa to 200 MPa) without considering martensite transformation.

Modeling diffusion in foamed polymer nanocomposites.

PubMed

Ippalapalli, Sandeep; Ranaprathapan, A Dileep; Singh, Sachchida N; Harikrishnan, G

2013-04-15

Two-way multicomponent diffusion processes in polymeric nanocomposite foams, where the condensed phase is nanoscopically reinforced with impermeable fillers, are investigated. The diffusion process involves simultaneous outward permeation of the components of the dispersed gas phase and inward diffusion of atmospheric air. The transient variation in thermal conductivity of foam is used as the macroscopic property to track the compositional variations of the dispersed gases due to the diffusion process. In the continuum approach adopted, the unsteady-state diffusion process is combined with tortuosity theory. The simulations conducted at ambient temperature reveal distinct regimes of diffusion processes in the nanocomposite foams owing to the reduction in the gas-transport rate induced by nanofillers. Simulations at a higher temperature are also conducted and the predictions are compared with experimentally determined thermal conductivities under accelerated diffusion conditions for polyurethane foams reinforced with clay nanoplatelets of varying individual lamellar dimensions. Intermittent measurements of foam thermal conductivity are performed while the accelerated diffusion proceeded. The predictions under accelerated diffusion conditions show good agreement with experimentally measured thermal conductivities for nanocomposite foams reinforced with low and medium aspect-ratios fillers. The model shows higher deviations for foams with fillers that have a high aspect ratio. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Physical properties of the Mars Exploration Rover landing sites as inferred from Mini-TES-derived thermal inertia

USGS Publications Warehouse

Fergason, R.L.; Christensen, P.R.; Bell, J.F.; Golombek, M.P.; Herkenhoff, K. E.; Kieffer, H.H.

2006-01-01

The Miniature Thermal Emission Spectrometer (Mini-TES) on board the two Mars Exploration Rovers provides the first opportunity to observe thermal properties from the Martian surface, relate these properties to orbital data, and perform soil conductivity experiments under Martian conditions. The thermal inertias of soils, bedforms, and rock at each landing site were derived to quantify the physical properties of these features and understand geologic processes occurring at these localities. The thermal inertia for the. Gusev plains rock target Bonneville Beacon (???1200 J m-2 K-1 s-1/2) is consistent with a dense, basaltic rock, but the rocks at the Columbia Hills have a lower thermal inertia (???620 J m-2 K-1 s-1/2), suggesting that they have a volcaniclasic origin. Bedforms on the floors of craters at both landing sites have thermal inertias of 200 J m-2 K-1 s-1/2, consistent with a particle diameter of ???160 ??m. This diameter is comparable to the most easily moved grain size in the current atmosphere on Mars, suggesting that these bedforms may have formed under current atmospheric conditions. Along the Meridiani plains, the thermal inertia is lower than that derived from TES and Thermal Emission Imaging System (THEMIS) orbital data. This discrepancy is not well understood. Mini-TES-derived thermal inertias at Gusev along a ???2.5 km traverse follow trends in thermal inertia measured from orbit with TES and THEMIS. However, along the traverse, there are variability and mixing of particle sizes that are not resolved in the orbital thermal inertia data due to meter-scale processes that are not identifiable at larger scales. Copyright 2006 by the American Geophysical Union.

Thermal energy storage apparatus, controllers and thermal energy storage control methods

DOEpatents

Hammerstrom, Donald J.

2016-05-03

Thermal energy storage apparatus, controllers and thermal energy storage control methods are described. According to one aspect, a thermal energy storage apparatus controller includes processing circuitry configured to access first information which is indicative of surpluses and deficiencies of electrical energy upon an electrical power system at a plurality of moments in time, access second information which is indicative of temperature of a thermal energy storage medium at a plurality of moments in time, and use the first and second information to control an amount of electrical energy which is utilized by a heating element to heat the thermal energy storage medium at a plurality of moments in time.

Gaussian ancillary bombardment

NASA Astrophysics Data System (ADS)

Grimmer, Daniel; Brown, Eric; Kempf, Achim; Mann, Robert B.; Martín-Martínez, Eduardo

2018-05-01

We analyze in full detail the time evolution of an open Gaussian quantum system rapidly bombarded by Gaussian ancillae. As a particular case this analysis covers the thermalization (or not) of a harmonic oscillator coupled to a thermal reservoir made of harmonic oscillators. We derive general results for this scenario and apply them to the problem of thermalization. We show that only a particular family of system-environment couplings will cause the system to thermalize to the temperature of its environment. We discuss that if we want to understand thermalization as ensuing from the Markovian interaction of a system with the individual microconstituents of its (thermal) environment then the process of thermalization is not as robust as one might expect.

Mercury recovery using a fluidized bed

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

Harriss, C.; Baum, D.L. Jr.

1996-12-31

Philip Environmental Services Corporation`s (Philip`s) innovative fluidized bed thermal desorption system recovers mercury from contaminated soil. Referred to as the Thermal Recycling System, Philip has constructed a mobile thermal desorption system that has a processing rate up to five tons per hour. The system includes a continuous-feed system, all radiant heat, inert gas atmosphere, hot gas filter, two-stage cooling, and a water treatment system. Based on treatability studies, the processed soil can meet cleanup objectives as low as two milligrams per kilogram and passes the mercury toxicity characteristic leaching procedure test. 4 refs., 2 figs., 1 tab.

Observational clues to the energy release process in impulsive solar bursts

NASA Technical Reports Server (NTRS)

Batchelor, David

1990-01-01

The nature of the energy release process that produces impulsive bursts of hard X-rays and microwaves during solar flares is discussed, based on new evidence obtained using the method of Crannell et al. (1978). It is shown that the hard X-ray spectral index gamma is negatively correlated with the microwave peak frequency, suggesting a common source for the microwaves and X-rays. The thermal and nonthermal models are compared. It is found that the most straightforward explanations for burst time behavior are shock-wave particle acceleration in the nonthermal model and thermal conduction fronts in the thermal model.

Physical Property Evaluation of ZnO Thin Film Fabricated by Low-Temperature Process for Flexible Transparent TFT.

PubMed

Khafe, Adie Bin Mohd; Watanabe, Hiraku; Yamauchi, Hiroshi; Kuniyoshi, Shigekazu; Iizuka, Masaaki; Sakai, Masatoshi; Kudo, Kazuhiro

2016-04-01

The usual silicon-based display back planes require fairly high process temperature and thus the development of a low temperature process is needed on flexible plastic substrates. A new type of flexible organic light emitting transistor (OLET) had been proposed and investigated in the previous work. By using ultraviolet/ozone (UV/O3) assisted thermal treatments on wet processed zinc oxide field effect transistor (ZnO-FET), through low-process temperature, ZnO-FETs were fabricated which succeeded to achieve target drain current value and mobility. In this study, physical property evaluation of ZnO was conducted in term of their crystallinity, the increase composition of ZnO formed inside the thin film and the decrease of the carbon impurities originated from aqueous solution of the ZnO itself. The X-ray diffraction (XRD) evaluation showed UV/03 assisted thermal treatment has no obvious effect towards crystallinity of ZnO in the range of low process temperature. Moreover, through X-ray photoelectron spectroscopy (XPS) evaluation and Fourier transform infrared (FT-IR) spectroscopy evaluation, more carbon impurities disappeared from the ZnO thin film and the increase of composition amount of ZnO, when the thin film was subjected to UV/O3 assisted thermal treatment. Therefore, UV/O3 assisted thermal treatment contributed in carbon impurities elimination and accelerate ZnO formation in ZnO thin film, which led to the improvement in the electrical property of ZnO-FET in the low-process temperature.

Evaluation of olivine ceramic refractories for thermal-energy-storage application

NASA Astrophysics Data System (ADS)

Palmour, H., III; Gay, B. M.; Cochran, R. L.

The degree of improvement in thermal and mechanical performance that can be obtained with an olivine thermal storage brick made of domestic materials using advanced processing techniques compared with state-of-the-art as represented by commercial European bricks is discussed. The goals and results of the study are given.

Theory of thermal conductivity in the disordered electron liquid

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

Schwiete, G., E-mail: schwiete@uni-mainz.de; Finkel’stein, A. M.

2016-03-15

We study thermal conductivity in the disordered two-dimensional electron liquid in the presence of long-range Coulomb interactions. We describe a microscopic analysis of the problem using the partition function defined on the Keldysh contour as a starting point. We extend the renormalization group (RG) analysis developed for thermal transport in the disordered Fermi liquid and include scattering processes induced by the long-range Coulomb interaction in the sub-temperature energy range. For the thermal conductivity, unlike for the electrical conductivity, these scattering processes yield a logarithmic correction that may compete with the RG corrections. The interest in this correction arises from themore » fact that it violates the Wiedemann–Franz law. We checked that the sub-temperature correction to the thermal conductivity is not modified either by the inclusion of Fermi liquid interaction amplitudes or as a result of the RG flow. We therefore expect that the answer obtained for this correction is final. We use the theory to describe thermal transport on the metallic side of the metal–insulator transition in Si MOSFETs.« less

Thermophysical and Thermomechanical Properties of Thermal Barrier Coating Systems

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2000-01-01

Thermal barrier coatings have been developed for advanced gas turbine and diesel engine applications to improve engine reliability and fuel efficiency. However, the issue of coating durability under high temperature cyclic conditions is still of major concern. The coating failure is closely related to thermal stresses and oxidation in the coating systems. Coating shrinkage cracking resulting from ceramic sintering and creep at high temperatures can further accelerate the coating failure process. The purpose of this paper is to address critical issues such as ceramic sintering and creep, thermal fatigue and their relevance to coating life prediction. Novel test approaches have been established to obtain critical thermophysical and thermomechanical properties of the coating systems under near-realistic temperature and stress gradients encountered in advanced engine systems. Emphasis is placed on the dynamic changes of the coating thermal conductivity and elastic modulus, fatigue and creep interactions, and resulting failure mechanisms during the simulated engine tests. Detailed experimental and modeling results describing processes occurring in the thermal barrier coating systems provide a framework for developing strategies to manage ceramic coating architecture, microstructure and properties.

Thermal injury models for optical treatment of biological tissues: a comparative study.

PubMed

Fanjul-Velez, Felix; Ortega-Quijano, Noe; Salas-Garcia, Irene; Arce-Diego, Jose L

2010-01-01

The interaction of optical radiation with biological tissues causes an increase in the temperature that, depending on its magnitude, can provoke a thermal injury process in the tissue. The establishment of laser irradiation pathological limits constitutes an essential task, as long as it enables to fix and delimit a range of parameters that ensure a safe treatment in laser therapies. These limits can be appropriately described by kinetic models of the damage processes. In this work, we present and compare several models for the study of thermal injury in biological tissues under optical illumination, particularly the Arrhenius thermal damage model and the thermal dosimetry model based on CEM (Cumulative Equivalent Minutes) 43°C. The basic concepts that link the temperature and exposition time with the tissue injury or cellular death are presented, and it will be shown that they enable to establish predictive models for the thermal damage in laser therapies. The results obtained by both models will be compared and discussed, highlighting the main advantages of each one and proposing the most adequate one for optical treatment of biological tissues.

Ground-based thermography of fluvial systems at low and high discharge reveals potential complex thermal heterogeneity driven by flow variation and bioroughness

USGS Publications Warehouse

Cardenas, M.B.; Harvey, J.W.; Packman, A.I.; Scott, D.T.

2008-01-01

Temperature is a primary physical and biogeochemical variable in aquatic systems. Field-based measurement of temperature at discrete sampling points has revealed temperature variability in fluvial systems, but traditional techniques do not readily allow for synoptic sampling schemes that can address temperature-related questions with broad, yet detailed, coverage. We present results of thermal infrared imaging at different stream discharge (base flow and peak flood) conditions using a handheld IR camera. Remotely sensed temperatures compare well with those measured with a digital thermometer. The thermal images show that periphyton, wood, and sandbars induce significant thermal heterogeneity during low stages. Moreover, the images indicate temperature variability within the periphyton community and within the partially submerged bars. The thermal heterogeneity was diminished during flood inundation, when the areas of more slowly moving water to the side of the stream differed in their temperature. The results have consequences for thermally sensitive hydroelogical processes and implications for models of those processes, especially those that assume an effective stream temperature. Copyright ?? 2008 John Wiley & Sons, Ltd.

Iron Oxide Films Prepared by Rapid Thermal Processing for Solar Energy Conversion

PubMed Central

Wickman, B.; Bastos Fanta, A.; Burrows, A.; Hellman, A.; Wagner, J. B.; Iandolo, B.

2017-01-01

Hematite is a promising and extensively investigated material for various photoelectrochemical (PEC) processes for energy conversion and storage, in particular for oxidation reactions. Thermal treatments during synthesis of hematite are found to affect the performance of hematite electrodes considerably. Herein, we present hematite thin films fabricated via one-step oxidation of Fe by rapid thermal processing (RTP). In particular, we investigate the effect of oxidation temperature on the PEC properties of hematite. Films prepared at 750 °C show the highest activity towards water oxidation. These films show the largest average grain size and the highest charge carrier density, as determined from electron microscopy and impedance spectroscopy analysis. We believe that the fast processing enabled by RTP makes this technique a preferred method for investigation of novel materials and architectures, potentially also on nanostructured electrodes, where retaining high surface area is crucial to maximize performance. PMID:28091573

Phase formation polycrystalline vanadium oxide via thermal annealing process under controlled nitrogen pressure

NASA Astrophysics Data System (ADS)

Jessadaluk, S.; Khemasiri, N.; Rahong, S.; Rangkasikorn, A.; Kayunkid, N.; Wirunchit, S.; Horprathum, M.; Chananonnawathron, C.; Klamchuen, A.; Nukeaw, J.

2017-09-01

This article provides an approach to improve and control crystal phases of the sputtering vanadium oxide (VxOy) thin films by post-thermal annealing process. Usually, as-deposited VxOy thin films at room temperature are amorphous phase: post-thermal annealing processes (400 °C, 2 hrs) under the various nitrogen (N2) pressures are applied to improve and control the crystal phase of VxOy thin films. The crystallinity of VxOy thin films changes from amorphous to α-V2O5 phase or V9O17 polycrystalline, which depend on the pressure of N2 carrier during annealing process. Moreover, the electrical resistivity of the VxOy thin films decrease from 105 Ω cm (amorphous) to 6×10-1 Ω cm (V9O17). Base on the results, our study show a simply method to improve and control phase formation of VxOy thin films.

Real time quantitative imaging for semiconductor crystal growth, control and characterization

NASA Technical Reports Server (NTRS)

Wargo, Michael J.

1991-01-01

A quantitative real time image processing system has been developed which can be software-reconfigured for semiconductor processing and characterization tasks. In thermal imager mode, 2D temperature distributions of semiconductor melt surfaces (900-1600 C) can be obtained with temperature and spatial resolutions better than 0.5 C and 0.5 mm, respectively, as demonstrated by analysis of melt surface thermal distributions. Temporal and spatial image processing techniques and multitasking computational capabilities convert such thermal imaging into a multimode sensor for crystal growth control. A second configuration of the image processing engine in conjunction with bright and dark field transmission optics is used to nonintrusively determine the microdistribution of free charge carriers and submicron sized crystalline defects in semiconductors. The IR absorption characteristics of wafers are determined with 10-micron spatial resolution and, after calibration, are converted into charge carrier density.

Plasma Spraying of Ceramics with Particular Difficulties in Processing

NASA Astrophysics Data System (ADS)

Mauer, G.; Schlegel, N.; Guignard, A.; Jarligo, M. O.; Rezanka, S.; Hospach, A.; Vaßen, R.

2015-01-01

Emerging new applications and growing demands of plasma-sprayed coatings initiate the development of new materials. Regarding ceramics, often complex compositions are employed to achieve advanced material properties, e.g., high thermal stability, low thermal conductivity, high electronic and ionic conductivity as well as specific thermo-mechanical properties and microstructures. Such materials however, often involve particular difficulties in processing by plasma spraying. The inhomogeneous dissociation and evaporation behavior of individual constituents can lead to changes of the chemical composition and the formation of secondary phases in the deposited coatings. Hence, undesired effects on the coating characteristics are encountered. In this work, examples of such challenging materials are investigated, namely pyrochlores applied for thermal barrier coatings as well as perovskites for gas separation membranes. In particular, new plasma spray processes like suspension plasma spraying and plasma spray-physical vapor deposition are considered. In some cases, plasma diagnostics are applied to analyze the processing conditions.

Role of thermal processes in dewetting of epitaxial Ag(111) film on Si(111)

DOE PAGES

Sanders, Charlotte E.; Zhang, Chendong D.; Kellogg, Gary L.; ...

2014-08-01

Epitaxially grown silver (Ag) film on silicon (Si) is an optimal plasmonic device platform, but its technological utility has been limited by its tendency to dewet rapidly under ambient conditions (standard temperature and pressure). The mechanisms driving this dewetting have not heretofore been determined. In our study, scanning probe microscopy and low-energy electron microscopy are used to compare the morphological evolution of epitaxial Ag(111)/Si(111) under ambient conditions with that of similarly prepared films heated under ultra-high vacuum (UHV) conditions. Furthermore, dewetting is seen to be initiated with the formation of pinholes, which might function to relieve strain in the film.more » We find that in the UHV environment, dewetting is determined by thermal processes, and while under ambient conditions, thermal processes are not required. Finally, we conclude that dewetting in ambient conditions is triggered by some chemical process, most likely oxidation.« less

In-situ and self-distributed: A new understanding on catalyzed thermal decomposition process of ammonium perchlorate over Nd{sub 2}O{sub 3}

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

Zou, Min, E-mail: zoumin3362765@163.com; Wang, Xin, E-mail: wangx@mail.njust.edu.cn; Jiang, Xiaohong, E-mail: jxh0668@sina.com

2014-05-01

Catalyzed thermal decomposition process of ammonium perchlorate (AP) over neodymium oxide (Nd{sub 2}O{sub 3}) was investigated. Catalytic performances of nanometer-sized Nd{sub 2}O{sub 3} and micrometer-sized Nd{sub 2}O{sub 3} were evaluated by differential scanning calorimetry (DSC). In contrast to universal concepts, catalysts in different sizes have nearly similar catalytic activities. Based on structural and morphological variation of the catalysts during the reaction, combined with mass spectrum analyses and studies of unmixed style, a new understanding of this catalytic process was proposed. We believed that the newly formed chloride neodymium oxide (NdOCl) was the real catalytic species in the overall thermal decompositionmore » of AP over Nd{sub 2}O{sub 3}. Meanwhile, it was the “self-distributed” procedure which occurred within the reaction that also worked for the improvement of overall catalytic activities. This work is of great value in understanding the roles of micrometer-sized catalysts used in heterogeneous reactions, especially the solid–solid reactions which could generate a large quantity of gaseous species. - Graphical abstract: In-situ and self-distributed reaction process in thermal decomposition of AP catalyzed by Nd{sub 2}O{sub 3}. - Highlights: • Micro- and nano-Nd{sub 2}O{sub 3} for catalytic thermal decomposition of AP. • No essential differences on their catalytic performances. • Structural and morphological variation of catalysts digs out catalytic mechanism. • This catalytic process is “in-situ and self-distributed” one.« less

On the Processing of Martensitic Steels in Continuous Galvanizing Lines: Part 1

NASA Astrophysics Data System (ADS)

Song, Taejin; Kwak, Jaihyun; de Cooman, B. C.

2012-01-01

Whereas low-carbon (<0.2 mass pct) martensitic grades can be produced easily in continuous annealing processing lines equipped with the required cooling capacity, the thermal cycles in continuous galvanizing lines make it difficult to produce hot-dip Zn or Zn-alloy coated high-strength martensitic grades. This is because of the tempering processes occurring during dipping of the strip in the liquid Zn bath and, in the case of galvannealed sheet steel, the short thermal treatment required to achieve the alloying between the Zn and the steel. These short additional thermal treatments last less than 30 seconds but severely degrade the mechanical properties. Using a combination of internal friction, X-ray diffraction, and transmission electron microscopy, it is shown that the ultrafine-grained lath microstructure allows for a rapid dislocation recovery and carbide formation during the galvanizing processes. In addition, the effective dislocation pinning occurring during the galvannealing process results in strain localization and the suppression of strain hardening.

Numerical analysis of the heating phase and densification mechanism in polymers selective laser melting process

NASA Astrophysics Data System (ADS)

Mokrane, Aoulaiche; Boutaous, M'hamed; Xin, Shihe

2018-05-01

The aim of this work is to address a modeling of the SLS process at the scale of the part in PA12 polymer powder bed. The powder bed is considered as a continuous medium with homogenized properties, meanwhile understanding multiple physical phenomena occurring during the process and studying the influence of process parameters on the quality of final product. A thermal model, based on enthalpy approach, will be presented with details on the multiphysical couplings that allow the thermal history: laser absorption, melting, coalescence, densification, volume shrinkage and on numerical implementation using FV method. The simulations were carried out in 3D with an in-house developed FORTRAN code. After validation of the model with comparison to results from literature, a parametric analysis will be proposed. Some original results as densification process and the thermal history with the evolution of the material, from the granular solid state to homogeneous melted state will be discussed with regards to the involved physical phenomena.

Investigation into the structural, morphological, mechanical and thermal behaviour of bacterial cellulose after a two-step purification process.

PubMed

Gea, Saharman; Reynolds, Christopher T; Roohpour, Nima; Wirjosentono, Basuki; Soykeabkaew, Nattakan; Bilotti, Emiliano; Peijs, Ton

2011-10-01

Bacterial cellulose (BC) is a natural hydrogel, which is produced by Acetobacter xylinum (recently renamed Gluconacetobacter xylinum) in culture and constitutes of a three-dimensional network of ribbon-shaped bundles of cellulose microfibrils. Here, a two-step purification process is presented that significantly improves the structural, mechanical, thermal and morphological behaviour of BC sheet processed from these hydrogels produced in static culture. Alkalisation of BC using a single-step treatment of 2.5 wt.% NaOH solution produced a twofold increase in Young's modulus of processed BC sheet over untreated BC sheet. Further enhancements are achieved after a second treatment with 2.5 wt.% NaOCl (bleaching). These treatments were carefully designed in order to prevent any polymorphic crystal transformation from cellulose I to cellulose II, which can be detrimental for the mechanical properties. Scanning electron microscopy and thermogravimetric analysis reveals that with increasing chemical treatment, morphological and thermal stability of the processed films are also improved. Copyright © 2011 Elsevier Ltd. All rights reserved.

Controlling thermal emission of phonon by magnetic metasurfaces

PubMed Central

Zhang, X.; Liu, H.; Zhang, Z. G.; Wang, Q.; Zhu, S. N.

2017-01-01

Our experiment shows that the thermal emission of phonon can be controlled by magnetic resonance (MR) mode in a metasurface (MTS). Through changing the structural parameter of metasurface, the MR wavelength can be tuned to the phonon resonance wavelength. This introduces a strong coupling between phonon and MR, which results in an anticrossing phonon-plasmons mode. In the process, we can manipulate the polarization and angular radiation of thermal emission of phonon. Such metasurface provides a new kind of thermal emission structures for various thermal management applications. PMID:28157206

Solar-thermal fluid-wall reaction processing

DOEpatents

Weimer, Alan W.; Dahl, Jaimee K.; Lewandowski, Allan A.; Bingham, Carl; Buechler, Karen J.; Grothe, Willy

2006-04-25

The present invention provides a method for carrying out high temperature thermal dissociation reactions requiring rapid-heating and short residence times using solar energy. In particular, the present invention provides a method for carrying out high temperature thermal reactions such as dissociation of hydrocarbon containing gases and hydrogen sulfide to produce hydrogen and dry reforming of hydrocarbon containing gases with carbon dioxide. In the methods of the invention where hydrocarbon containing gases are dissociated, fine carbon black particles are also produced. The present invention also provides solar-thermal reactors and solar-thermal reactor systems.

Solar-Thermal Fluid-Wall Reaction Processing

DOEpatents

Weimer, A. W.; Dahl, J. K.; Lewandowski, A. A.; Bingham, C.; Raska Buechler, K. J.; Grothe, W.

2006-04-25

The present invention provides a method for carrying out high temperature thermal dissociation reactions requiring rapid-heating and short residence times using solar energy. In particular, the present invention provides a method for carrying out high temperature thermal reactions such as dissociation of hydrocarbon containing gases and hydrogen sulfide to produce hydrogen and dry reforming of hydrocarbon containing gases with carbon dioxide. In the methods of the invention where hydrocarbon containing gases are dissociated, fine carbon black particles are also produced. The present invention also provides solar-thermal reactors and solar-thermal reactor systems.

Toward a High-Efficient Utilization of Solar Radiation by Quad-Band Solar Spectral Splitting.

PubMed

Cao, Feng; Huang, Yi; Tang, Lu; Sun, Tianyi; Boriskina, Svetlana V; Chen, Gang; Ren, Zhifeng

2016-12-01

The promising quad-band solar spectral splitter incorporates the properties of the optical filter and the spectrally selective solar thermal absorber can direct PV band to PV modules and absorb thermal band energy for thermal process with low thermal losses. It provides a new strategy for spectral splitting and offers potential ways for hybrid PVT system design. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermal analysis of microlens formation on a sensitized gelatin layer

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

Muric, Branka; Pantelic, Dejan; Vasiljevic, Darko

2009-07-01

We analyze a mechanism of direct laser writing of microlenses. We find that thermal effects and photochemical reactions are responsible for microlens formation on a sensitized gelatin layer. An infrared camera was used to assess the temperature distribution during the microlens formation, while the diffraction pattern produced by the microlens itself was used to estimate optical properties. The study of thermal processes enabled us to establish the correlation between thermal and optical parameters.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Duane Williams prepares the blanket insulation to be installed on the body flap on orbiter Discovery. The blankets are part of the Orbiter Thermal Protection System, thermal shields to protect against temperatures as high as 3,000° Fahrenheit, which are produced during descent for landing. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

NASA Image and Video Library

2003-12-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Duane Williams prepares the blanket insulation to be installed on the body flap on orbiter Discovery. The blankets are part of the Orbiter Thermal Protection System, thermal shields to protect against temperatures as high as 3,000° Fahrenheit, which are produced during descent for landing. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

Three-Dimensional Finite Element Ablative Thermal Response and Thermostructural Design of Thermal Protection Systems

NASA Technical Reports Server (NTRS)

Dec, John A.; Braun, Robert D.

2011-01-01

A finite element ablation and thermal response program is presented for simulation of three-dimensional transient thermostructural analysis. The three-dimensional governing differential equations and finite element formulation are summarized. A novel probabilistic design methodology for thermal protection systems is presented. The design methodology is an eight step process beginning with a parameter sensitivity study and is followed by a deterministic analysis whereby an optimum design can determined. The design process concludes with a Monte Carlo simulation where the probabilities of exceeding design specifications are estimated. The design methodology is demonstrated by applying the methodology to the carbon phenolic compression pads of the Crew Exploration Vehicle. The maximum allowed values of bondline temperature and tensile stress are used as the design specifications in this study.

Analysis of In Situ Thermal Ion Measurements from the MICA Sounding Rocket

NASA Astrophysics Data System (ADS)

Fernandes, P. A.; Lynch, K. A.; Zettergren, M. D.; Hampton, D. L.; Fisher, L. E.; Powell, S. P.

2014-12-01

The MICA sounding rocket launched on 19 Feb. 2012 into several discrete, localized arcs in the wake of a westward traveling surge. In situ and ground-based observations provide a measured response of the ionosphere to preflight and localized auroral drivers. Initial analysis of the in situ thermal ion data indicate possible measurement of an ion conic at low altitude (< 325 km). In the low-energy regime, the response of the instrument varies from the ideal because the measured thermal ion population is sensitive to the presence of the instrument. The plasma is accelerated in the frame of the instrument due to flows, ram, and acceleration through the sheath which forms around the spacecraft. The energies associated with these processes are large compared to the thermal energy. Correct interpretation of thermal plasma measurements requires accounting for all of these plasma processes and the non-ideal response of the instrument in the low-energy regime. This is an experimental and modeling project which involves thorough analysis of ionospheric thermal ion data from the MICA campaign. Analysis includes modeling and measuring the instrument response in the low-energy regime as well as accounting for the complex sheath formed around the instrument. This results in a forward model in which plasma parameters of the thermal plasma are propagated through the sheath and instrument models, resulting in an output which matches the in situ measurement. In the case of MICA, we are working toward answering the question of the initiating source processes that result, at higher altitudes, in well-developed conics and outflow on auroral field lines.

The Evaporation and Survival of Cluster Galaxy Coronae. I. The Effectiveness of Isotropic Thermal Conduction Including Saturation

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

Vijayaraghavan, Rukmani; Sarazin, Craig, E-mail: rukmani@virginia.edu

We simulate the evolution of cluster galaxy hot interstellar medium (ISM) gas that is a result of the effects of ram pressure and thermal conduction in the intracluster medium (ICM). At the density and temperature of the ICM, the mean free paths of ICM electrons are comparable to the sizes of galaxies, therefore electrons can efficiently transport heat that is due to thermal conduction from the hot ICM to the cooler ISM. Galaxies consisting of dark matter halos and hot gas coronae are embedded in an ICM-like “wind tunnel” in our simulations. In this paper, we assume that thermal conductionmore » is isotropic and include the effects of saturation. We find that as heat is transferred from the ICM to the ISM, the cooler denser ISM expands and evaporates. This process is significantly faster than gas loss due to ram pressure stripping; for our standard model galaxy, the evaporation time is 160 Myr, while the ram pressure stripping timescale is 2.5 Gyr. Thermal conduction also suppresses the formation of shear instabilities, and there are no stripped ISM tails since the ISM evaporates before tails can form. Observations of long-lived X-ray emitting coronae and ram pressure stripped X-ray tails in galaxies in group and cluster environments therefore require that thermal conduction is suppressed or offset by some additional physical process. The most likely process is anisotropic thermal conduction that is due to magnetic fields in the ISM and ICM, which we simulate and study in the next paper in this series.« less

The Evaporation and Survival of Cluster Galaxy Coronae. I. The Effectiveness of Isotropic Thermal Conduction Including Saturation

NASA Astrophysics Data System (ADS)

Vijayaraghavan, Rukmani; Sarazin, Craig

2017-05-01

We simulate the evolution of cluster galaxy hot interstellar medium (ISM) gas that is a result of the effects of ram pressure and thermal conduction in the intracluster medium (ICM). At the density and temperature of the ICM, the mean free paths of ICM electrons are comparable to the sizes of galaxies, therefore electrons can efficiently transport heat that is due to thermal conduction from the hot ICM to the cooler ISM. Galaxies consisting of dark matter halos and hot gas coronae are embedded in an ICM-like “wind tunnel” in our simulations. In this paper, we assume that thermal conduction is isotropic and include the effects of saturation. We find that as heat is transferred from the ICM to the ISM, the cooler denser ISM expands and evaporates. This process is significantly faster than gas loss due to ram pressure stripping; for our standard model galaxy, the evaporation time is 160 Myr, while the ram pressure stripping timescale is 2.5 Gyr. Thermal conduction also suppresses the formation of shear instabilities, and there are no stripped ISM tails since the ISM evaporates before tails can form. Observations of long-lived X-ray emitting coronae and ram pressure stripped X-ray tails in galaxies in group and cluster environments therefore require that thermal conduction is suppressed or offset by some additional physical process. The most likely process is anisotropic thermal conduction that is due to magnetic fields in the ISM and ICM, which we simulate and study in the next paper in this series.