Materials and integration schemes for above-IC integrated optics

NARCIS (Netherlands)

Schmitz, Jurriaan; Rangarajan, B.; Kovalgin, Alexeij Y.

2014-01-01

A study is presented on silicon oxynitride material for waveguides and germanium-silicon alloys for p-i-n diodes. The materials are manufactured at low, CMOS-backend compatible temperatures, targeting the integration of optical functions on top of CMOS chips. Low-temperature germanium-silicon

New ways of integrating material knowledge into the design process

DEFF Research Database (Denmark)

Højris, Anders; Nielsen, Louise Møller

2013-01-01

– based on technical performance, no longer apply. Accordingly the approach in this paper is to view information and knowledge about materials through the perspective of organizational memory and technology brokering. This paper is build upon two cases from the German based design studio: designaffairs...... libraries and thereby access to information on new material possibilities has also changed the way designers integrate knowledge about materials into the design process. This means that the traditional design process model, where the selection of materials takes place after the design of form and function...... in order to help clients to find the right material among hundreds of samples. Furthermore a number of material libraries have also been developed into online database, which provides detailed information about new material and makes the information accessible from almost everywhere. The access to material...

49 CFR 192.909 - How can an operator change its integrity management program?

Science.gov (United States)

2010-10-01

... (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Gas Transmission Pipeline Integrity Management § 192.909 How can an operator change its integrity management...

Micro-Encapsulated Phase Change Materials: A Review of Encapsulation, Safety and Thermal Characteristics

Directory of Open Access Journals (Sweden)

Ahmed Hassan

2016-10-01

Full Text Available Phase change materials (PCMs have been identified as potential candidates for building energy optimization by increasing the thermal mass of buildings. The increased thermal mass results in a drop in the cooling/heating loads, thus decreasing the energy demand in buildings. However, direct incorporation of PCMs into building elements undermines their structural performance, thereby posing a challenge for building integrity. In order to retain/improve building structural performance, as well as improving energy performance, micro-encapsulated PCMs are integrated into building materials. The integration of microencapsulation PCMs into building materials solves the PCM leakage problem and assures a good bond with building materials to achieve better structural performance. The aim of this article is to identify the optimum micro-encapsulation methods and materials for improving the energy, structural and safety performance of buildings. The article reviews the characteristics of micro-encapsulated PCMs relevant to building integration, focusing on safety rating, structural implications, and energy performance. The article uncovers the optimum combinations of the shell (encapsulant and core (PCM materials along with encapsulation methods by evaluating their merits and demerits.

Ontology based heterogeneous materials database integration and semantic query

Science.gov (United States)

Zhao, Shuai; Qian, Quan

2017-10-01

Materials digital data, high throughput experiments and high throughput computations are regarded as three key pillars of materials genome initiatives. With the fast growth of materials data, the integration and sharing of data is very urgent, that has gradually become a hot topic of materials informatics. Due to the lack of semantic description, it is difficult to integrate data deeply in semantic level when adopting the conventional heterogeneous database integration approaches such as federal database or data warehouse. In this paper, a semantic integration method is proposed to create the semantic ontology by extracting the database schema semi-automatically. Other heterogeneous databases are integrated to the ontology by means of relational algebra and the rooted graph. Based on integrated ontology, semantic query can be done using SPARQL. During the experiments, two world famous First Principle Computational databases, OQMD and Materials Project are used as the integration targets, which show the availability and effectiveness of our method.

Characterization of Concrete Mixes Containing Phase Change Materials

Science.gov (United States)

Paksoy, H.; Kardas, G.; Konuklu, Y.; Cellat, K.; Tezcan, F.

2017-10-01

Phase change materials (PCM) can be used in passive building applications to achieve near zero energy building goals. For this purpose PCM can be added in building structures and materials in different forms. Direct incorporation, form stabilization and microencapsulation are different forms used for PCM integration in building materials. In addition to thermal properties of PCM itself, there are several other criteria that need to be fulfilled for the PCM enhanced building materials. Mechanical properties, corrosive effects, morphology and thermal buffering have to be determined for reliable and long-term applications in buildings. This paper aims to give an overview of characterization methods used to determine these properties in PCM added fresh concrete mixes. Thermal, compressive strength, corrosion, and microscopic test results for concrete mixes with PCM are discussed.

Energy Performance and Optimal Control of Air-conditioned Buildings Integrated with Phase Change Materials

Science.gov (United States)

Zhu, Na

This thesis presents an overview of the previous research work on dynamic characteristics and energy performance of buildings due to the integration of PCMs. The research work on dynamic characteristics and energy performance of buildings using PCMs both with and without air-conditioning is reviewed. Since the particular interest in using PCMs for free cooling and peak load shifting, specific research efforts on both subjects are reviewed separately. A simplified physical dynamic model of building structures integrated with SSPCM (shaped-stabilized phase change material) is developed and validated in this study. The simplified physical model represents the wall by 3 resistances and 2 capacitances and the PCM layer by 4 resistances and 2 capacitances respectively while the key issue is the parameter identification of the model. This thesis also presents the studies on the thermodynamic characteristics of buildings enhanced by PCM and on the investigation of the impacts of PCM on the building cooling load and peak cooling demand at different climates and seasons as well as the optimal operation and control strategies to reduce the energy consumption and energy cost by reducing the air-conditioning energy consumption and peak load. An office building floor with typical variable air volume (VAV) air-conditioning system is used and simulated as the reference building in the comparison study. The envelopes of the studied building are further enhanced by integrating the PCM layers. The building system is tested in two selected cities of typical climates in China including Hong Kong and Beijing. The cold charge and discharge processes, the operation and control strategies of night ventilation and the air temperature set-point reset strategy for minimizing the energy consumption and electricity cost are studied. This thesis presents the simulation test platform, the test results on the cold storage and discharge processes, the air-conditioning energy consumption and demand

Sprayable Phase Change Coating Thermal Protection Material

Science.gov (United States)

Richardson, Rod W.; Hayes, Paul W.; Kaul, Raj

2005-01-01

NASA has expressed a need for reusable, environmentally friendly, phase change coating that is capable of withstanding the heat loads that have historically required an ablative thermal insulation. The Space Shuttle Program currently relies on ablative materials for thermal protection. The problem with an ablative insulation is that, by design, the material ablates away, in fulfilling its function of cooling the underlying substrate, thus preventing the insulation from being reused from flight to flight. The present generation of environmentally friendly, sprayable, ablative thermal insulation (MCC-l); currently use on the Space Shuttle SRBs, is very close to being a reusable insulation system. In actual flight conditions, as confirmed by the post-flight inspections of the SRBs, very little of the material ablates. Multi-flight thermal insulation use has not been qualified for the Space Shuttle. The gap that would have to be overcome in order to implement a reusable Phase Change Coating (PCC) is not unmanageable. PCC could be applied robotically with a spray process utilizing phase change material as filler to yield material of even higher strength and reliability as compared to MCC-1. The PCC filled coatings have also demonstrated potential as cryogenic thermal coatings. In experimental thermal tests, a thin application of PCC has provided the same thermal protection as a much thicker and heavier application of a traditional ablative thermal insulation. In addition, tests have shown that the structural integrity of the coating has been maintained and phase change performance after several aero-thermal cycles was not affected. Experimental tests have also shown that, unlike traditional ablative thermal insulations, PCC would not require an environmental seal coat, which has historically been required to prevent moisture absorption by the thermal insulation, prevent environmental degradation, and to improve the optical and aerodynamic properties. In order to reduce

Integral gnosis and the material other

Directory of Open Access Journals (Sweden)

Eero Karhu

2015-11-01

Full Text Available In this article, I look at Ken Wilber’s Integral Theory as mimesis. This invites me to look at Integral Theory in three ways. First, I look at Integral Theory as process of making materialistic alterity, thus maintaining and fortifying the spirituality of the self. Second, I look at it from the perspective of the dialectics of epistemologies of estrangement and intimacy, raising questions concerning the legitimacy of the juxtaposing interpretative and explanatory approaches to culture. Third, I look at it from a social perspective, as a powerful instance of modern mimesis that creates a typically modern history. I will show how Integral Theory is grounded in the modern intuition of agency being distinct from and superior to the outer material world. To the extent that cultural agency has to materialize in some form, so does Integral Theory. My aim is to recall the close relations of scientific discourse with spirituality, even with magic and even more importantly, I want to show how supposedly secular intuitions of identity and agency bear strong potential for spiritual and religious discourse.

Using InTeGrate materials to develop interdisciplinary thinking for a sustainable future

Science.gov (United States)

Awad, A. A.; Gilbert, L.; Iverson, E. A. R.; Manduca, C. A.; Steer, D. N.

2017-12-01

InTeGrate materials focus on societal grand challenges, sustainability, and interdisciplinary problems through developing geoscientific habits of mind, the use of credible data, and systems thinking. The materials are freely available 2-3 week modules and courses that allow instructors to focus on a wide variety of topics from regulating carbon emissions, changing biosphere, and storms and community resilience to environmental justice, ocean sustainability, and humans' dependence on mineral resources, integrating a variety of relevant interdisciplinary activities throughout. Presented with interdisciplinary approaches, students learn with tools to integrate engineering, policy, economics, and social aspects with the science to address the challenges. Students' ability to apply interdisciplinary approaches to address sustainability problems is made visible through the essays they write as a part of the materials assessment. InTeGrate modules have been adopted and implemented by faculty members interested in sustainability themes and innovative pedagogy, and have reached more than 50,000 students in all 50 states, Puerto Rico, India, and Micronesia. Student data were collected from 533 assessment essays in 57 undergraduate classes. The essays required students to describe a global challenge in an interdisciplinary manner through identifying scientific implications, and connecting it to economic, social and policy decisions. Students also completed a second essay assessing their systems thinking ability, a geoscience literacy exam (GLE), and demographic and attitudinal surveys. Scores for students enrolled in classes using InTeGrate materials were compared to scores from students in similar classes that did not use InteGrate materials. The InTeGrate and control groups had equivalent GLE scores and demographic characteristics. Essay scores for students in InTeGrate introductory or majors courses outperformed students in comparable level control courses as measured by

Optimisation of integrated energy and materials systems

International Nuclear Information System (INIS)

Gielen, D.J.; Okken, P.A.

1994-06-01

To define cost-effective long term CO2 reduction strategies an integrated energy and materials system model for the Netherlands for the period 2000-2040 is developed. The model is based upon the energy system model MARKAL, which configures an optimal mix of technologies to satisfy the specified energy and product/materials service demands. This study concentrates on CO 2 emission reduction in the materials system. For this purpose, the energy system model is enlarged with a materials system model including all steps 'from cradle to grave'. The materials system model includes 29 materials, 20 product groups and 30 waste materials. The system is divided into seven types of technologies; 250 technologies are modeled. The results show that the integrated optimisation of the energy system and the materials system can significantly reduce the emission reduction costs, especially at higher reduction percentages. The reduction is achieved through shifts in materials production and waste handling and through materials substitution in products. Shifts in materials production and waste management seem cost-effective, while the cost-effectiveness of shifts in product composition is sensitive due to the cost structure of products. For the building sector, transportation applications and packaging, CO 2 policies show a significant impact on prices, and shifts in product composition could occur. For other products, the reduction through materials substitution seems less promising. The impact on materials consumption seems most significant for cement (reduced), timber and aluminium (both increased). For steel and plastics, the net effect is balanced, but shifts between applications do occur. The MARKAL-approach is feasible to study integrated energy and materials systems. The progress compared to other environmental system analysis instruments is much more insight in the interaction of technologies on a national scale and in time

Heterogeneous Monolithic Integration of Single-Crystal Organic Materials.

Science.gov (United States)

Park, Kyung Sun; Baek, Jangmi; Park, Yoonkyung; Lee, Lynn; Hyon, Jinho; Koo Lee, Yong-Eun; Shrestha, Nabeen K; Kang, Youngjong; Sung, Myung Mo

2017-02-01

Manufacturing high-performance organic electronic circuits requires the effective heterogeneous integration of different nanoscale organic materials with uniform morphology and high crystallinity in a desired arrangement. In particular, the development of high-performance organic electronic and optoelectronic devices relies on high-quality single crystals that show optimal intrinsic charge-transport properties and electrical performance. Moreover, the heterogeneous integration of organic materials on a single substrate in a monolithic way is highly demanded for the production of fundamental organic electronic components as well as complex integrated circuits. Many of the various methods that have been designed to pattern multiple heterogeneous organic materials on a substrate and the heterogeneous integration of organic single crystals with their crystal growth are described here. Critical issues that have been encountered in the development of high-performance organic integrated electronics are also addressed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Numerical study and design optimization of electromagnetic energy harvesters integrated with flexible magnetic materials

Energy Technology Data Exchange (ETDEWEB)

Yoon, Sang Won [Hanyang University, Seoul (Korea, Republic of)

2017-05-15

This study presents a new design of an electromagnetic energy harvester integrated with a soft magnetic material. The harvester design optimizes the magnetic material characteristics and the size of a rectangular permanent magnet. The design employs a complete magnetic circuit made of (1) a thin-film soft magnetic material that facilitates a flexible but highly (magnetically) permeable beam and (2) an optimally-sized magnet that maximizes the harvester performance. The design is demonstrated to reduce magnetic flux leakage, and thus considerably enhances both magnetic flux density (B) and its change by time (dB/dt), which both influence harvester performance. The improvement in harvester performances strongly depends on critical design parameters, especially, the magnet size and characteristics of magnetic materials, including permeability, stiffness, and thickness. The analyses conclude that recently-introduced nanomaterials (having ultrahigh magnetic permeability) can potentially innovate harvester performances. However, the performance may be degraded without design optimization. Once optimized, the integrated nanomaterials facilitate a significant improvement compared with a conventional design without integrated magnetic materials.

Numerical study and design optimization of electromagnetic energy harvesters integrated with flexible magnetic materials

International Nuclear Information System (INIS)

Yoon, Sang Won

2017-01-01

This study presents a new design of an electromagnetic energy harvester integrated with a soft magnetic material. The harvester design optimizes the magnetic material characteristics and the size of a rectangular permanent magnet. The design employs a complete magnetic circuit made of (1) a thin-film soft magnetic material that facilitates a flexible but highly (magnetically) permeable beam and (2) an optimally-sized magnet that maximizes the harvester performance. The design is demonstrated to reduce magnetic flux leakage, and thus considerably enhances both magnetic flux density (B) and its change by time (dB/dt), which both influence harvester performance. The improvement in harvester performances strongly depends on critical design parameters, especially, the magnet size and characteristics of magnetic materials, including permeability, stiffness, and thickness. The analyses conclude that recently-introduced nanomaterials (having ultrahigh magnetic permeability) can potentially innovate harvester performances. However, the performance may be degraded without design optimization. Once optimized, the integrated nanomaterials facilitate a significant improvement compared with a conventional design without integrated magnetic materials.

Dynamically Reconfigurable Metadevice Employing Nanostructured Phase-Change Materials.

Science.gov (United States)

Zhu, Zhihua; Evans, Philip G; Haglund, Richard F; Valentine, Jason G

2017-08-09

Mastering dynamic free-space spectral control and modulation in the near-infrared (NIR) and optical regimes remains a challenging task that is hindered by the available functional materials at high frequencies. In this work, we have realized an efficient metadevice capable of spectral control by minimizing the thermal mass of a vanadium dioxide phase-change material (PCM) and placing the PCM at the feed gap of a bow-tie field antenna. The device has an experimentally measured tuning range of up to 360 nm in the NIR and a modulation depth of 33% at the resonant wavelength. The metadevice is configured for integrated and local heating, leading to faster switching and more precise spatial control compared with devices based on phase-change thin films. We envisage that the combined advantages of this device will open new opportunities for signal processing, memory, security, and holography at optical frequencies.

Advances in Integrated Computational Materials Engineering "ICME"

Science.gov (United States)

Hirsch, Jürgen

The methods of Integrated Computational Materials Engineering that were developed and successfully applied for Aluminium have been constantly improved. The main aspects and recent advances of integrated material and process modeling are simulations of material properties like strength and forming properties and for the specific microstructure evolution during processing (rolling, extrusion, annealing) under the influence of material constitution and process variations through the production process down to the final application. Examples are discussed for the through-process simulation of microstructures and related properties of Aluminium sheet, including DC ingot casting, pre-heating and homogenization, hot and cold rolling, final annealing. New results are included of simulation solution annealing and age hardening of 6xxx alloys for automotive applications. Physically based quantitative descriptions and computer assisted evaluation methods are new ICME methods of integrating new simulation tools also for customer applications, like heat affected zones in welding of age hardening alloys. The aspects of estimating the effect of specific elements due to growing recycling volumes requested also for high end Aluminium products are also discussed, being of special interest in the Aluminium producing industries.

Photonic Structure-Integrated Two-Dimensional Material Optoelectronics

Directory of Open Access Journals (Sweden)

Tianjiao Wang

2016-12-01

Full Text Available The rapid development and unique properties of two-dimensional (2D materials, such as graphene, phosphorene and transition metal dichalcogenides enable them to become intriguing candidates for future optoelectronic applications. To maximize the potential of 2D material-based optoelectronics, various photonic structures are integrated to form photonic structure/2D material hybrid systems so that the device performance can be manipulated in controllable ways. Here, we first introduce the photocurrent-generation mechanisms of 2D material-based optoelectronics and their performance. We then offer an overview and evaluation of the state-of-the-art of hybrid systems, where 2D material optoelectronics are integrated with photonic structures, especially plasmonic nanostructures, photonic waveguides and crystals. By combining with those photonic structures, the performance of 2D material optoelectronics can be further enhanced, and on the other side, a high-performance modulator can be achieved by electrostatically tuning 2D materials. Finally, 2D material-based photodetector can also become an efficient probe to learn the light-matter interactions of photonic structures. Those hybrid systems combine the advantages of 2D materials and photonic structures, providing further capacity for high-performance optoelectronics.

Division of Integrity and Materials

International Nuclear Information System (INIS)

Zdarek, J.

1995-01-01

The organization structure is described of the Division of Integrity and Materials, Institute of Nuclear Research plc, Rez, and the main fields of their activities given. Listed are the major research projects of the Division in 1994. (Z.S.)

Passive thermal management using phase change materials

Science.gov (United States)

Ganatra, Yash Yogesh

The trend of enhanced functionality and reducing thickness of mobile devices has. led to a rapid increase in power density and a potential thermal bottleneck since. thermal limits of components remain unchanged. Active cooling mechanisms are not. feasible due to size, weight and cost constraints. This work explores the feasibility. of a passive cooling system based on Phase Change Materials (PCMs) for thermal. management of mobile devices. PCMs stabilize temperatures due to the latent heat. of phase change thus increasing the operating time of the device before threshold. temperatures are exceeded. The primary contribution of this work is the identification. of key parameters which influence the design of a PCM based thermal management. system from both the experiments and the numerical models. This work first identifies strategies for integrating PCMs in an electronic device. A. detailed review of past research, including experimental techniques and computational. models, yields key material properties and metrics to evaluate the performance of. PCMs. Subsequently, a miniaturized version of a conventional thermal conductivity. measurement technique is developed to characterize thermal resistance of PCMs. Further, latent heat and transition temperatures are also characterized for a wide. range of PCMs. In-situ measurements with PCMs placed on the processor indicate that some. PCMs can extend the operating time of the device by as much as a factor of 2.48. relative to baseline tests (with no PCMs). This increase in operating time is investigated. by computational thermal models that explore various integration locations, both at the package and device level.

Organic-inorganic hybrid material SUNCONNECT® for photonic integrated circuit

Science.gov (United States)

Nawata, Hideyuki; Oshima, Juro; Kashino, Tsubasa

2018-02-01

In this paper, we report the feature and properties about organic-inorganic hybrid material, "SUNCONNECT®" for photonic integrated circuit. "SUNCONNECT®" materials have low propagation loss at 1310nm (0.29dB/cm) and 1550nm (0.45dB/cm) respectively. In addition, the material has high thermal resistance both high temperature annealing test at 300°C and also 260°C solder heat resistance test. For actual device application, high reliability is required. 85°C /85% test was examined by using multi-mode waveguide. As a result, it indicated that variation of insertion loss property was not changed significantly after high temperature / high humidity test. For the application to photonic integrated circuit, it was demonstrated to fabricate polymer optical waveguide by using three different methods. Single-micron core pattern can be fabricated on cladding layer by using UV lithography with proximity gap exposure. Also, single-mode waveguide can be also fabricated with over cladding. On the other hands, "Mosquito method" and imprint method can be applied to fabricate polymer optical waveguide. Remarkably, these two methods can fabricate gradedindex type optical waveguide without using photo mask. In order to evaluate the optical performance, NFP's observation, measurement of insertion loss and propagation loss by cut-back methods were carried out by using each waveguide sample.

Methodology for Evaluating Raw Material Changes to RSRM Elastomeric Insulation Materials

Science.gov (United States)

Mildenhall, Scott D.; McCool, Alex (Technical Monitor)

2001-01-01

The Reusable Solid Rocket Motor (RSRM) uses asbestos and silicon dioxide filled acrylonitrile butadiene rubber (AS-NBR) as the primary internal insulation to protect the case from heat. During the course of the RSRM Program, several changes have been made to the raw materials and processing of the AS-NBR elastomeric insulation material. These changes have been primarily caused by raw materials becoming obsolete. In addition, some process changes have been implemented that were deemed necessary to improve the quality and consistency of the AS-NBR insulation material. Each change has been evaluated using unique test efforts customized to determine the potential impacts of the specific raw material or process change. Following the evaluations, the various raw material and process changes were successfully implemented with no detectable effect on the performance of the AS-NBR insulation. This paper will discuss some of the raw material and process changes evaluated, the methodology used in designing the unique test plans, and the general evaluation results. A summary of the change history of RSRM AS-NBR internal insulation is also presented.

Nanoscale phase-change materials and devices

International Nuclear Information System (INIS)

Zheng, Qinghui; Wang, Yuxi; Zhu, Jia

2017-01-01

Phase-change materials (PCMs) that can reversibly transit between crystalline and amorphous phases have been widely used for data-storage and other functional devices. As PCMs scale down to nanoscale, the properties and transition procedures can vary, bringing both challenges and opportunities in scalability. This article describes the physical structures, properties and applications of nanoscale phase-change materials and devices. The limitations and performance of scaling properties in phase-change materials and the recent progress and challenges in phase-change devices are presented. At the end, some emerging applications related to phase-change materials are also introduced. (topical review)

Nanoscale phase-change materials and devices

Science.gov (United States)

Zheng, Qinghui; Wang, Yuxi; Zhu, Jia

2017-06-01

Phase-change materials (PCMs) that can reversibly transit between crystalline and amorphous phases have been widely used for data-storage and other functional devices. As PCMs scale down to nanoscale, the properties and transition procedures can vary, bringing both challenges and opportunities in scalability. This article describes the physical structures, properties and applications of nanoscale phase-change materials and devices. The limitations and performance of scaling properties in phase-change materials and the recent progress and challenges in phase-change devices are presented. At the end, some emerging applications related to phase-change materials are also introduced.

The determinants of materiality disclosure in integrated corporate reporting

OpenAIRE

Chiara Mio; Marco Fasan

2014-01-01

The aim of this study is to test what drives the way in which companies disclose materiality in their Integrated Reports (IRs). Materiality is one of the main themes (and challenges) in the IR discourse, and it will probably play a central role in the actual success of the International Integrated Reporting Council framework. Companies managing to actually implement the materiality principle, will produce IRs which are concise and able to provide relevant information on the future performance...

Development of an integrated system for nuclear material accountancy and control at JAERI

International Nuclear Information System (INIS)

Nishimura, Hideo; Nishizawa, Satoshi

1993-01-01

This paper describes the design concept and the current status of an integrated system for nuclear material accountancy and control, which is under development at JAERI. We, at JAERI, have decided to update the current system for material accountancy and control and to develop the integrated new system with a consolidated data base in order to augment transparency, credibility and promptness of the system, to materialize a prudent control of obligations required by bilateral nuclear cooperation agreements, and to give information for the physical protection, safely handling, property control and cost-effective use of nuclear material and for public relations. The system is composed of two work-stations operated by UNIX, one for implementation and the other for development, and many terminals located at the headquarters, administrative offices, and research facilities and laboratories. It is connected with a mainframe computer. There are many files on the data base to record inventory changes, book and physical inventories, and statistics on material balances. These files are controlled by a commercial data base management system which enables us to make access to data on the files with a simple query language, spread sheet type software or an application program. (author)

Design, Fabrication, Characterization and Modeling of Integrated Functional Materials

Science.gov (United States)

2015-12-01

activities is expected to lead to new devices/ systems /composite materials useful for the USAMRMC. 15. SUBJECT TERMS Functional materials, integrated...fabrication, nanobiotechnology, multifunctional, dimensional integration, nanocomposites, sensor technology, thermoelectrics, solar cells, photovoltaics ...loop measured in the presence of an AC field, and can be increased by tuning several parameters, such as the nanoparticles’ size , saturation

Integrated modelling in materials and process technology

DEFF Research Database (Denmark)

Hattel, Jesper Henri

2008-01-01

Integrated modelling of entire process sequences and the subsequent in-service conditions, and multiphysics modelling of the single process steps are areas that increasingly support optimisation of manufactured parts. In the present paper, three different examples of modelling manufacturing...... processes from the viewpoint of combined materials and process modelling are presented: solidification of thin walled ductile cast iron, integrated modelling of spray forming and multiphysics modelling of friction stir welding. The fourth example describes integrated modelling applied to a failure analysis...

Advanced materials for integrated optical waveguides

CERN Document Server

Tong Ph D, Xingcun Colin

2014-01-01

This book provides a comprehensive introduction to integrated optical waveguides for information technology and data communications. Integrated coverage ranges from advanced materials, fabrication, and characterization techniques to guidelines for design and simulation. A concluding chapter offers perspectives on likely future trends and challenges. The dramatic scaling down of feature sizes has driven exponential improvements in semiconductor productivity and performance in the past several decades. However, with the potential of gigascale integration, size reduction is approaching a physical limitation due to the negative impact on resistance and inductance of metal interconnects with current copper-trace based technology. Integrated optics provides a potentially lower-cost, higher performance alternative to electronics in optical communication systems. Optical interconnects, in which light can be generated, guided, modulated, amplified, and detected, can provide greater bandwidth, lower power consumption, ...

2D materials in electro-optic modulation: energy efficiency, electrostatics, mode overlap, material transfer and integration

Science.gov (United States)

Ma, Zhizhen; Hemnani, Rohit; Bartels, Ludwig; Agarwal, Ritesh; Sorger, Volker J.

2018-02-01

Here we discuss the physics of electro-optic modulators deploying 2D materials. We include a scaling laws analysis and show how energy-efficiency and speed change for three underlying cavity systems as a function of critical device length scaling. A key result is that the energy-per-bit of the modulator is proportional to the volume of the device, thus making the case for submicron-scale modulators possible deploying a plasmonic optical mode. We then show how Graphene's Pauli-blocking modulation mechanism is sensitive to the device operation temperature, whereby a reduction of the temperature enables a 10× reduction in modulator energy efficiency. Furthermore, we show how the high-index tunability of graphene is able to compensate for the small optical overlap factor of 2D-based material modulators, which is unlike classical silicon-based dispersion devices. Lastly, we demonstrate a novel method towards a 2D material printer suitable for cross-contamination free and on-demand printing. The latter paves the way to integrate 2D materials seamlessly into taped-out photonic chips.

Phase change material for temperature control and material storage

Science.gov (United States)

Wessling, Jr., Francis C. (Inventor); Blackwood, James M. (Inventor)

2011-01-01

A phase change material comprising a mixture of water and deuterium oxide is described, wherein the mole fraction of deuterium oxide is selected so that the mixture has a selected phase change temperature within a range between 0.degree. C. and 4.degree. C. The mixture is placed in a container and used for passive storage and transport of biomaterials and other temperature sensitive materials. Gels, nucleating agents, freezing point depression materials and colorants may be added to enhance the characteristics of the mixture.

Heat Storage Performance of the Prefabricated Hollow Core Concrete Deck Element with Integrated Microencapsulated Phase Change Material

DEFF Research Database (Denmark)

Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

2012-01-01

The paper presents the numerically calculated dynamic heat storage capacity of the prefabricated hollow core concrete deck element with and without microencapsulated phase change material (PCM). The reference deck is the ordinary deck made of standard concrete material and that is broadly used...

Reversible switching in phase-change materials

OpenAIRE

Wojciech Wełnic; Matthias Wuttig

2008-01-01

Phase-change materials are successfully employed in optical data storage and are becoming a promising candidate for future electronic storage applications. Despite the increasing technological interest, many fundamental properties of these materials remain poorly understood. However, in the last few years the understanding of the material properties of phase-change materials has increased significantly. At the same time, great advances have been achieved in technological applications in elect...

Integration of phase change materials in compressed hydrogen gas systems: Modelling and parametric analysis

DEFF Research Database (Denmark)

Mazzucco, Andrea; Rothuizen, Erasmus; Jørgensen, Jens-Erik

2016-01-01

to the phase change material, mainly occurs after the fueling is completed, resulting in a hydrogen peak temperature higher than 85 C and a lower fueled mass than a gas-cooled system. Such a mass reduction accounts for 12% with respect to the case of a standard tank system fueled at 40 C. A parametric analysis...

Accelerating the design of biomimetic materials by integrating RNA-seq with proteomics and materials science.

Science.gov (United States)

Guerette, Paul A; Hoon, Shawn; Seow, Yiqi; Raida, Manfred; Masic, Admir; Wong, Fong T; Ho, Vincent H B; Kong, Kiat Whye; Demirel, Melik C; Pena-Francesch, Abdon; Amini, Shahrouz; Tay, Gavin Z; Ding, Dawei; Miserez, Ali

2013-10-01

Efforts to engineer new materials inspired by biological structures are hampered by the lack of genomic data from many model organisms studied in biomimetic research. Here we show that biomimetic engineering can be accelerated by integrating high-throughput RNA-seq with proteomics and advanced materials characterization. This approach can be applied to a broad range of systems, as we illustrate by investigating diverse high-performance biological materials involved in embryo protection, adhesion and predation. In one example, we rapidly engineer recombinant squid sucker ring teeth proteins into a range of structural and functional materials, including nanopatterned surfaces and photo-cross-linked films that exceed the mechanical properties of most natural and synthetic polymers. Integrating RNA-seq with proteomics and materials science facilitates the molecular characterization of natural materials and the effective translation of their molecular designs into a wide range of bio-inspired materials.

Integrating Molecular Computation and Material Production in an Artificial Subcellular Matrix

DEFF Research Database (Denmark)

Fellermann, Harold; Hadorn, Maik; Bönzli, Eva

Living systems are unique in that they integrate molecular recognition and information processing with material production on the molecular scale. Pre- dominant locus of this integration is the cellular matrix, where a multitude of biochemical reactions proceed simultaneously in highly compartmen......Living systems are unique in that they integrate molecular recognition and information processing with material production on the molecular scale. Pre- dominant locus of this integration is the cellular matrix, where a multitude of biochemical reactions proceed simultaneously in highly...... compartmentalized re- action compartments that interact and get delivered through vesicle trafficking. The European Commission funded project MatchIT (Matrix for Chemical IT) aims at creating an artificial cellular matrix that seamlessly integrates infor- mation processing and material production in much the same...

Evaluation method for change of concentration of nuclear fuel material

International Nuclear Information System (INIS)

Kiyono, Takeshi; Ando, Ryohei.

1997-01-01

The present invention provides a method of evaluating the change of concentration of compositions of nuclear fuel element materials loaded to a reactor along with neutron irradiation based on analytic calculation not relying on integration with time. Namely, the method of evaluating the change of concentration of nuclear fuel materials comprises evaluating the changing concentration of nuclear fuel materials based on nuclear fission, capturing of neutrons and radioactive decaying along with neutron irradiation. In this case, an optional nuclide on a nuclear conversion chain is determined as a standard nuclide. When the main fuel material is Pu-239, it is determined as the standard nuclide. The ratio of the concentration of the standard nuclide to that of the nuclide as an object of the evaluation can be expressed by the ratio of the cross sectional area of neutron nuclear reaction of the standard nuclide to the cross sectional area of the neutron nuclear reaction of the nuclide as the object of the evaluation. Accordingly, the concentration of the nuclide as the object of the evaluation can be expressed by an analysis formula shown by an analysis function for the ratio of the concentration of the standard nuclide to the cross section of the neutron nuclear reaction. As a result, by giving an optional concentration of the standard nuclide to the analysis formula, the concentration of each of other nuclides can be determined analytically. (I.S.)

Integrated material accountancy system

International Nuclear Information System (INIS)

Calabozo, M.; Buiza, A.

1991-01-01

In this paper we present the system that we are actually using for Nuclear Material Accounting and Manufacturing Management in our UO 2 Fuel Fabrication Plant located at Juzbado, Salamanca, Spain. The system is based mainly on a real time data base which gather data for all the operations performed in our factory from UO 2 powder reception to fuel assemblies shipment to the customers. The accountancy is just an important part of the whole integrated system covering all the aspects related to manufacturing: planning, traceability, Q.C. analysis, production control and accounting data

A compressed hydrogen gas storage system with an integrated phase change material

DEFF Research Database (Denmark)

Mazzucco, Andrea; Rothuizen, Erasmus Damgaard; Jørgensen, Jens Erik

2015-01-01

below the critical temperature of 85 °C, while filling the hydrogen at ambient temperature. Results show that a 10-mm-thick layer of paraffin wax can absorb enough heat to reduce the adiabatic temperature by 20 K when compared to a standard Type IV tank. The heat transfer from the gas to the phase...... change material, mainly occurs after the fueling is completed, resulting in a higher hydrogen peak temperature inside the tank and a lower fuelled mass than a gas-cooled system. Such a mass reduction accounts for 12% with respect to the case of a standard tank system fuelled at -40 °C....

Development of carbon nanotube modified cement paste with microencapsulated phase-change material for structural-functional integrated application.

Science.gov (United States)

Cui, Hongzhi; Yang, Shuqing; Memon, Shazim Ali

2015-04-10

Microencapsulated phase-change materials (MPCM) can be used to develop a structural-functional integrated cement paste having high heat storage efficiency and suitable mechanical strength. However, the incorporation of MPCM has been found to degrade the mechanical properties of cement based composites. Therefore, in this research, the effect of carbon nanotubes (CNTs) on the properties of MPCM cement paste was evaluated. Test results showed that the incorporation of CNTs in MPCM cement paste accelerated the cement hydration reaction. SEM micrograph showed that CNTs were tightly attached to the cement hydration products. At the age of 28 days, the percentage increase in flexural and compressive strength with different dosage of CNTs was found to be up to 41% and 5% respectively. The optimum dosage of CNTs incorporated in MPCM cement paste was found to be 0.5 wt %. From the thermal performance test, it was found that the cement paste panels incorporated with different percentages of MPCM reduced the temperature measured at the center of the room by up to 4.6 °C. Inverse relationship was found between maximum temperature measured at the center of the room and the dosage of MPCM.

Development of Carbon Nanotube Modified Cement Paste with Microencapsulated Phase-Change Material for Structural–Functional Integrated Application

Directory of Open Access Journals (Sweden)

Hongzhi Cui

2015-04-01

Full Text Available Microencapsulated phase-change materials (MPCM can be used to develop a structural–functional integrated cement paste having high heat storage efficiency and suitable mechanical strength. However, the incorporation of MPCM has been found to degrade the mechanical properties of cement based composites. Therefore, in this research, the effect of carbon nanotubes (CNTs on the properties of MPCM cement paste was evaluated. Test results showed that the incorporation of CNTs in MPCM cement paste accelerated the cement hydration reaction. SEM micrograph showed that CNTs were tightly attached to the cement hydration products. At the age of 28 days, the percentage increase in flexural and compressive strength with different dosage of CNTs was found to be up to 41% and 5% respectively. The optimum dosage of CNTs incorporated in MPCM cement paste was found to be 0.5 wt %. From the thermal performance test, it was found that the cement paste panels incorporated with different percentages of MPCM reduced the temperature measured at the center of the room by up to 4.6 °C. Inverse relationship was found between maximum temperature measured at the center of the room and the dosage of MPCM.

An integrated web medicinal materials DNA database: MMDBD (Medicinal Materials DNA Barcode Database

Directory of Open Access Journals (Sweden)

But Paul

2010-06-01

Full Text Available Abstract Background Thousands of plants and animals possess pharmacological properties and there is an increased interest in using these materials for therapy and health maintenance. Efficacies of the application is critically dependent on the use of genuine materials. For time to time, life-threatening poisoning is found because toxic adulterant or substitute is administered. DNA barcoding provides a definitive means of authentication and for conducting molecular systematics studies. Owing to the reduced cost in DNA authentication, the volume of the DNA barcodes produced for medicinal materials is on the rise and necessitates the development of an integrated DNA database. Description We have developed an integrated DNA barcode multimedia information platform- Medicinal Materials DNA Barcode Database (MMDBD for data retrieval and similarity search. MMDBD contains over 1000 species of medicinal materials listed in the Chinese Pharmacopoeia and American Herbal Pharmacopoeia. MMDBD also contains useful information of the medicinal material, including resources, adulterant information, medical parts, photographs, primers used for obtaining the barcodes and key references. MMDBD can be accessed at http://www.cuhk.edu.hk/icm/mmdbd.htm. Conclusions This work provides a centralized medicinal materials DNA barcode database and bioinformatics tools for data storage, analysis and exchange for promoting the identification of medicinal materials. MMDBD has the largest collection of DNA barcodes of medicinal materials and is a useful resource for researchers in conservation, systematic study, forensic and herbal industry.

Recent progresses and achievements in photovoltaic-phase change material technology: A review with special treatment on photovoltaic thermal-phase change material systems

International Nuclear Information System (INIS)

Islam, M.M.; Pandey, A.K.; Hasanuzzaman, M.; Rahim, N.A.

2016-01-01

Highlights: • Broad summary of phase change materials based cooling for photovoltaic modules. • Compendium on phase change materials that are mostly used in photovoltaic systems. • Extension of heat availability period by 75–100% with phase change material. • Heat storage potential improves by 33–50% more with phase change material. • Future trend and move in photovoltaic thermal research. - Abstract: This communication lays out an appraisal on the recent works of phase change materials based thermal management techniques for photovoltaic systems with special focus on the so called photovoltaic thermal-phase change material system. Attempt has also been made to draw wide-ranging classification of both photovoltaic and photovoltaic thermal systems and their conventional cooling or heat harvesting methods developed so far so that feasible phase change materials application area in these systems can be pointed out. In addition, a brief literature on phase change materials with particular focus on their solar application has also been presented. Overview of the researches and studies establish that using phase change materials for photovoltaic thermal control is technically viable if some issues like thermal conductivity or phase stability are properly addressed. The photovoltaic thermal-phase change material systems are found to offer 33% (maximum 50%) more heat storage potential than the conventional photovoltaic-thermal water system and that with 75–100% extended heat availability period and around 9% escalation in output. Reduction in temperature attained with photovoltaic thermal-phase change material system is better than that with regular photovoltaic-thermal water system, too. Studies also show the potential of another emerging technology of photovoltaic thermal-microencapsulated phase change material system that makes use of microencapsulated phase change materials in thermal regulation. Future focus areas on photovoltaic thermal-phase change

Materials research for passive solar systems: Solid-state phase-change materials

Science.gov (United States)

Benson, D. K.; Webb, J. D.; Burrows, R. W.; McFadden, J. D. O.; Christensen, C.

1985-03-01

A set of solid-state phase-change materials is being evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol (C5H12O4), pentaglycerinve (C5H12O3), and neopentyl glycol (C5H12O2). Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature between 25 C and 188 C, and have latent heats of transformation etween 20 and 70 cal/g. Transformation temperatures, specific heats, and latent heats of transformation have been measured for a number of these materials. Limited cyclic experiments suggest that the solid solutions are stable. These phase-change materials exhibit large amounts of undercooling; however, the addition of certain nucleating agents as particulate dispersions in the solid phase-change material greatly reduces this effect. Computer simulations suggest that the use of an optimized solid-state phase-change material in a Trombe wall could provide better performance than a concrete Trombe wall four times thicker and nine times heavier.

Preliminary Design and Investigation of Integrated Compressor with Composite Material Wheel

Science.gov (United States)

Wang, Jifeng; Müller, Norbert

2012-06-01

An integrated water vapor compressor with composite material wheel is developed and strength analysis using FEM is presented. The design of wound composite material allows for integrating all rotating parts of the drive that may simply reduce to only the rotor of the electrical motor, since no drive shaft is required anymore. This design can reduce the number of parts and mass, which is convenient for engineers to maintain the compressor. The electrical motors are brushless DC motors operating through a frequency drive and apply a torque on the wheels through the materials bonded in the wheel shrouds. This system allows a large amount of compression to be produced in a multi-stage compression setup. To determine the stress and vibration characteristics of this integrated compressor, numerical analysis is carried out using FEM. The simulation result shows that the integrated compressor with composite material wheel can be used in a chiller system where water as a refrigerant.

A New Methodology for the Integration of Performance Materials into the Clothing Curriculum

OpenAIRE

Power, Jess

2014-01-01

This paper presents a model for integrating the study of performance materials into the clothing curriculum. In recent years there has been an increase in demand for stylish, functional and versatile sports apparel. Analysts predict this will reach US$126.30 billion by 2015. This growth is accredited to dramatic lifestyle changes and increasing participation in sports/leisurely pursuits particularly by women. The desire to own performance clothing for specific outdoor pursuits is increasing a...

Phase change materials science and applications

CERN Document Server

Raoux, Simone

2009-01-01

""Phase Change Materials: Science and Applications"" provides a unique introduction of this rapidly developing field. This clearly written volume describes the material science of these fascinating materials from a theoretical and experimental perspective.

Anomalous phase change characteristics in Fe-Te materials

International Nuclear Information System (INIS)

Fu, X. T.; Song, W. D.; Ji, R.; Ho, H. W.; Wang, L.; Hong, M. H.

2012-01-01

Phase change materials have become significantly attractive due to its unique characteristics for its extensive applications. In this paper, a kind of phase change material, which consists of Fe and Te components, is developed. The crystallization temperature of the Fe-Te materials is 180 deg. C for Fe 1.19 Te and can be adjusted by the Fe/Te ratio. High-speed phase change in the Fe-Te materials has been demonstrated by nanosecond laser irradiation. Comparing to conventional phase change materials, the Fe-Te materials exhibit an anomalous optical property that has higher reflectivity at amorphous than crystalline state, which is useful for data storage design.

Experimental investigation of two-stage thermoelectric generator system integrated with phase change materials

DEFF Research Database (Denmark)

Ahmadi Atouei, Saeed; Ranjbar, Ali Akbar; Rezaniakolaei, Alireza

2017-01-01

this amount of voltage just for 2100 s. Therefore, the proposed design makes TEG systems more suitable for wireless sensor applications when the heat source does not provide steady thermal energy. In this study, four different patterns of thermal power applied to the TTEG system are considered. These patterns...... experimentally. In the first stage, a TEG module installed between a phase change material (PCM) heat sink, as cooling system, and an electrical heater, as the heat source. Because of the inherent characteristics of PCMs to save the thermal energy as latent heat, the PCM heat sink is used as the heat source...

Cumulative energy demand and global warming potential of a building-integrated solar thermal system with/without phase change material.

Science.gov (United States)

Lamnatou, Chr; Motte, F; Notton, G; Chemisana, D; Cristofari, C

2018-04-15

Building-integrated solar thermal (BIST) systems are a specific type of solar thermal systems which are integrated into the building and they participate in building functionality. The present article is about the life-cycle assessment of different options of a BIST system (Mediterranean climatic conditions: Ajaccio, France). The environmental profile of the studied configurations is assessed by means of CED (cumulative energy demand), GWP (global warming potential) and EPBT (energy payback time). The proposed configurations (for the collector) include: i) a system without PCM (phase change material) using only rock wool as insulation and ii) a system with PCM (myristic acid) and rock wool. Concerning life-cycle results based on CED and GWP 100a (scenario without recycling), the configuration without PCM shows 0.67 MJ prim /kWh and 0.06 kg CO 2.eq /kWh while the configuration with PCM presents 0.74 MJ prim /kWh and 0.08 kg CO 2.eq /kWh. Regarding EPBT, if the inputs for pumping/auxiliary heating are not taken into account, both configurations (with/without PCM) have almost the same EPBT (about 1.3 years). On the other hand, if the inputs for pumping/auxiliary heating are considered, EPBT is lower for the system with PCM. In addition, scenarios with recycling have been examined and the results demonstrate that recycling considerably improves the environmental profile of the studied configurations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Integrated assessment of climate change

International Nuclear Information System (INIS)

Morgan, M.G.

1994-01-01

Many researchers are working on all the separate parts of the climate problem. The objective of integrated assessment is to put the results from this work together in order to look carefully at the big picture so as to: (1) keep a proper sense of perspective about the problem, since climate change will occur in the presence of many other natural and human changes; (2) develop the understanding necessary to support informed decision making by many different key public and private actors around the world; and (3) assure that the type and mix of climate-related research that is undertaken will be as useful as possible to decisions makers in both the near and long term. This paper outlines a set of design guidelines for formulating integrated assessment programs and projects and then outlines some of the current problems and opportunities. Selected points are illustrated by drawing on results from the integrated assessment research now in progress at Carnegie Mellon University

Theoretical model of an evacuated tube heat pipe solar collector integrated with phase change material

International Nuclear Information System (INIS)

Naghavi, M.S.; Ong, K.S.; Badruddin, I.A.; Mehrali, M.; Silakhori, M.; Metselaar, H.S.C.

2015-01-01

The purpose of this paper is to model theoretically a solar hot water system consisting of an array of ETHPSC (evacuated tube heat pipe solar collectors) connected to a common manifold filled with phase change material and acting as a LHTES (latent heat thermal energy storage) tank. Solar energy incident on the ETHPSC is collected and stored in the LHTES tank. The stored heat is then transferred to the domestic hot water supply via a finned heat exchanger pipe placed inside the tank. A combination of mathematical algorithms is used to model a complete process of the heat absorption, storage and release modes of the proposed system. The results show that for a large range of flow rates, the thermal performance of the ETHPSC-LHTES system is higher than that of a similar system without latent heat storage. Furthermore, the analysis shows that the efficiency of the introduced system is less sensitive to the draw off water flowrate than a conventional system. Analysis indicates that this system could be applicable as a complementary part to conventional ETHPSC systems to be able to produce hot water at night time or at times with weak radiation. - Highlights: • The ETHPSC is integrated with PCM at manifold side for night hot water demands. • The thermal performance of the ETHPSC-PCM is often higher than the baseline model. • The efficiency of the proposed model is stable for different flow rates. • Using PCM as thermal storage increases reliability on the performance of the system.

Radiation-induced attenuation in integrated optical materials

International Nuclear Information System (INIS)

Evans, B.D.

1989-01-01

This paper reports that three materials commonly employed in opto-electronic integrated circuits evaluated for radiation-induced optical attenuation in the range 300 nm to 3000 nm. These include optically clear epoxy and crystalline lithium niobate after Co-60 exposure and crystalline tellurium dioxide after mixed gamma/fast-neutron exposure. In all these materials, however, induced loss was restricted to shorter wavelengths; attenuation induced at the telecommunications windows near 850, 1300 and 1550 nm was <0.1 dB/cm

Conformal Coating of a Phase Change Material on Ordered Plasmonic Nanorod Arrays for Broadband All-Optical Switching

Energy Technology Data Exchange (ETDEWEB)

Guo, Peijun; Weimer, Matthew S. [Department; Emery, Jonathan D.; Diroll, Benjamin T.; Chen, Xinqi; Hock, Adam S. [Department; Chang, Robert P. H.; Martinson, Alex B. F.; Schaller, Richard D.

2016-12-19

Actively tunable optical transmission through artificial metamaterials holds great promise for next-generation nanophotonic devices and metasurfaces. Plasmonic nanostructures and phase change materials have been extensively studied to this end due to their respective strong interactions with light and tunable dielectric constants under external stimuli. Seamlessly integrating plasmonic components with phase change materials, as demonstrated in the present work, can facilitate phase change by plasmonically enabled light confinement and meanwhile make use of the high sensitivity of plasmon resonances to the variation of dielectric constant associated with the phase change. The hybrid platform here is composed of plasmonic indium tin-oxide nanorod arrays (ITO-NRAs) conformally coated with an ultrathin layer of a prototypical phase change material, vanadium dioxide (VO2), which enables all-optical modulation of the infrared as well as the visible spectral ranges. The interplay between the intrinsic plasmonic nonlinearity of ITO-NRAs and the phase transition induced permittivity change of VO2 gives rise to spectral and temporal responses that cannot be achieved with individual material components alone.

Conformal Coating of a Phase Change Material on Ordered Plasmonic Nanorod Arrays for Broadband All-Optical Switching.

Science.gov (United States)

Guo, Peijun; Weimer, Matthew S; Emery, Jonathan D; Diroll, Benjamin T; Chen, Xinqi; Hock, Adam S; Chang, Robert P H; Martinson, Alex B F; Schaller, Richard D

2017-01-24

Actively tunable optical transmission through artificial metamaterials holds great promise for next-generation nanophotonic devices and metasurfaces. Plasmonic nanostructures and phase change materials have been extensively studied to this end due to their respective strong interactions with light and tunable dielectric constants under external stimuli. Seamlessly integrating plasmonic components with phase change materials, as demonstrated in the present work, can facilitate phase change by plasmonically enabled light confinement and meanwhile make use of the high sensitivity of plasmon resonances to the variation of dielectric constant associated with the phase change. The hybrid platform here is composed of plasmonic indium-tin-oxide nanorod arrays (ITO-NRAs) conformally coated with an ultrathin layer of a prototypical phase change material, vanadium dioxide (VO 2 ), which enables all-optical modulation of the infrared as well as the visible spectral ranges. The interplay between the intrinsic plasmonic nonlinearity of ITO-NRAs and the phase transition induced permittivity change of VO 2 gives rise to spectral and temporal responses that cannot be achieved with individual material components alone.

Materials Integration and Doping of Carbon Nanotube-based Logic Circuits

Science.gov (United States)

Geier, Michael

Over the last 20 years, extensive research into the structure and properties of single- walled carbon nanotube (SWCNT) has elucidated many of the exceptional qualities possessed by SWCNTs, including record-setting tensile strength, excellent chemical stability, distinctive optoelectronic features, and outstanding electronic transport characteristics. In order to exploit these remarkable qualities, many application-specific hurdles must be overcome before the material can be implemented in commercial products. For electronic applications, recent advances in sorting SWCNTs by electronic type have enabled significant progress towards SWCNT-based integrated circuits. Despite these advances, demonstrations of SWCNT-based devices with suitable characteristics for large-scale integrated circuits have been limited. The processing methodologies, materials integration, and mechanistic understanding of electronic properties developed in this dissertation have enabled unprecedented scales of SWCNT-based transistor fabrication and integrated circuit demonstrations. Innovative materials selection and processing methods are at the core of this work and these advances have led to transistors with the necessary transport properties required for modern circuit integration. First, extensive collaborations with other research groups allowed for the exploration of SWCNT thin-film transistors (TFTs) using a wide variety of materials and processing methods such as new dielectric materials, hybrid semiconductor materials systems, and solution-based printing of SWCNT TFTs. These materials were integrated into circuit demonstrations such as NOR and NAND logic gates, voltage-controlled ring oscillators, and D-flip-flops using both rigid and flexible substrates. This dissertation explores strategies for implementing complementary SWCNT-based circuits, which were developed by using local metal gate structures that achieve enhancement-mode p-type and n-type SWCNT TFTs with widely separated and

Integrated Photonic Devices Incorporating Low-Loss Fluorinated Polymer Materials

Directory of Open Access Journals (Sweden)

Hyung-Jong Lee

2011-06-01

Full Text Available Low-loss polymer materials incorporating fluorinated compounds have been utilized for the investigation of various functional optical devices useful for optical communication and optical sensor systems. Since reliability issues concerning the polymer device have been resolved, polymeric waveguide devices have been gradually adopted for commercial application systems. The two most successfully commercialized polymeric integrated optic devices, variable optical attenuators and digital optical switches, are reviewed in this paper. Utilizing unique properties of optical polymers which are not available in other optical materials, novel polymeric optical devices are proposed including widely tunable external cavity lasers and integrated optical current sensors.

Crystallization kinetics of phase change materials

Energy Technology Data Exchange (ETDEWEB)

Klein, Michael; Sontheimer, Tobias; Wuttig, Matthias [I. Physikalisches Institut (1A), RWTH Aachen (Germany)

2008-07-01

Phase change materials are fascinating materials. They can be rapidly switched between two metastable states, the amorphous and crystalline phase, which show pronounced contrast in their optical and electrical properties. They are already widely used as the active layer in rewritable optical media and are expected to be used in the upcoming phase change random access memory (PRAM). Here we show measurements of the crystallization kinetics of chalcogenide materials that lead to a deeper understanding of these processes. This work focuses mainly on the Ge-Sb-Te system but also includes Ag-In-Te materials. The crystallization behaviour of these materials was investigated with an ex-situ annealing method employing the precise oven of a differential scanning calorimeter and imaging techniques employing atomic force microscopy and optical microscopy.

Integrated risk analysis of global climate change

International Nuclear Information System (INIS)

Shlyakhter, Alexander; Wilson, Richard; Valverde A, L.J. Jr.

1995-01-01

This paper discusses several factors that should be considered in integrated risk analyses of global climate change. We begin by describing how the problem of global climate change can be subdivided into largely independent parts that can be linked together in an analytically tractable fashion. Uncertainty plays a central role in integrated risk analyses of global climate change. Accordingly, we consider various aspects of uncertainty as they relate to the climate change problem. We also consider the impacts of these uncertainties on various risk management issues, such as sequential decision strategies, value of information, and problems of interregional and intergenerational equity. (author)

Ultrathin Shape Change Smart Materials.

Science.gov (United States)

Xu, Weinan; Kwok, Kam Sang; Gracias, David H

2018-02-20

With the discovery of graphene, significant research has focused on the synthesis, characterization, and applications of ultrathin materials. Graphene has also brought into focus other ultrathin materials composed of organics, polymers, inorganics, and their hybrids. Together, these ultrathin materials have unique properties of broad significance. For example, ultrathin materials have a large surface area and high flexibility which can enhance conformal contact in wearables and sensors leading to improved sensitivity. When porous, the short transverse diffusion length in these materials allows rapid mass transport. Alternatively, when impermeable, these materials behave as an ultrathin barrier. Such controlled permeability is critical in the design of encapsulation and drug delivery systems. Finally, ultrathin materials often feature defect-free and single-crystal-like two-dimensional atomic structures resulting in superior mechanical, optical, and electrical properties. A unique property of ultrathin materials is their low bending rigidity, which suggests that they could easily be bent, curved, or folded into 3D shapes. In this Account, we review the emerging field of 2D to 3D shape transformations of ultrathin materials. We broadly define ultrathin to include materials with a thickness below 100 nm and composed of a range of organic, inorganic, and hybrid compositions. This topic is important for both fundamental and applied reasons. Fundamentally, bending and curving of ultrathin films can cause atomistic and molecular strain which can alter their physical and chemical properties and lead to new 3D forms of matter which behave very differently from their planar precursors. Shape change can also lead to new 3D architectures with significantly smaller form factors. For example, 3D ultrathin materials would occupy a smaller space in on-chip devices or could permeate through tortuous media which is important for miniaturized robots and smart dust applications. Our

Application of phase-change materials in memory taxonomy.

Science.gov (United States)

Wang, Lei; Tu, Liang; Wen, Jing

2017-01-01

Phase-change materials are suitable for data storage because they exhibit reversible transitions between crystalline and amorphous states that have distinguishable electrical and optical properties. Consequently, these materials find applications in diverse memory devices ranging from conventional optical discs to emerging nanophotonic devices. Current research efforts are mostly devoted to phase-change random access memory, whereas the applications of phase-change materials in other types of memory devices are rarely reported. Here we review the physical principles of phase-change materials and devices aiming to help researchers understand the concept of phase-change memory. We classify phase-change memory devices into phase-change optical disc, phase-change scanning probe memory, phase-change random access memory, and phase-change nanophotonic device, according to their locations in memory hierarchy. For each device type we discuss the physical principles in conjunction with merits and weakness for data storage applications. We also outline state-of-the-art technologies and future prospects.

An integrated approach towards future ballistic neck protection materials selection.

Science.gov (United States)

Breeze, John; Helliker, Mark; Carr, Debra J

2013-05-01

Ballistic protection for the neck has historically taken the form of collars attached to the ballistic vest (removable or fixed), but other approaches, including the development of prototypes incorporating ballistic material into the collar of an under body armour shirt, are now being investigated. Current neck collars incorporate the same ballistic protective fabrics as the soft armour of the remaining vest, reflecting how ballistic protective performance alone has historically been perceived as the most important property for neck protection. However, the neck has fundamental differences from the thorax in terms of anatomical vulnerability, flexibility and equipment integration, necessitating a separate solution from the thorax in terms of optimal materials selection. An integrated approach towards the selection of the most appropriate combination of materials to be used for each of the two potential designs of future neck protection has been developed. This approach requires evaluation of the properties of each potential material in addition to ballistic performance alone, including flexibility, mass, wear resistance and thermal burden. The aim of this article is to provide readers with an overview of this integrated approach towards ballistic materials selection and an update of its current progress in the development of future ballistic neck protection.

From phase-change materials to thermoelectrics?

Energy Technology Data Exchange (ETDEWEB)

Schneider, Matthias N.; Rosenthal, Tobias; Oeckler, Oliver [Dept. of Chemistry, Ludwig Maximilian Univ. Munich (Germany); Stiewe, Christian [German Aerospace Center, Cologne (Germany)

2010-07-01

Metastable tellurides play an important role as phase-change materials in data storage media and non-volatile RAM devices. The corresponding crystalline phases with very simple basic structures are not stable as bulk materials at ambient conditions, however, for a broad range of compositions they represent stable high-temperature phases. In the system Ge/Sb/Te, rocksalt-type high-temperature phases are characterized by a large number of vacancies randomly distributed over the cation position, which order as 2D vacancy layers upon cooling. Short-range order in quenched samples produces pronounced nanostructures by the formation of twin domains and finite intersecting vacancy layers. As phase-change materials are usually semimetals or small-bandgap semiconductors and efficient data storage requires low thermal conductivity, bulk materials with similar compositions and properties can be expected to exhibit promising thermoelectric characteristics. Nanostructuring by phase transitions that involve partial vacancy ordering may enhance the efficiency of such thermoelectrics. We have shown that germanium antimony tellurides with compositions close to those used as phase-change materials in rewritable Blu-Ray Discs, e.g. (GeTe){sub 12}Sb{sub 2}Te{sub 3}, exhibit thermoelectric figures of merit of up to ZT = 1.3 at 450 C if a nanodomain structure is induced by rapidly quenching the cubic high-temperature phase. Structural changes have been elucidated by X-ray diffraction and high-resolution electron microscopy. (orig.)

Integrating UNESCO ICT-Based Instructional Materials in Chemistry Lessons

Directory of Open Access Journals (Sweden)

CHARLIE P. NACARIO

2014-08-01

Full Text Available This study determined the effectiveness of the lessons in Chemistry integrating UNESCO ICT-based instructional material on the achievement of Chemistry students at Central Bicol State University of Agriculture. It aimed to identify lessons that may be developed integrating UNESCO ICT-based instructional materials, determine the effect of the developed lessons using the material on: conceptual understanding; science process skills; and attitude towards chemistry and gather insights from the experiences of the students and teacher. The study used the single group pretest and posttest experimental design. Descriptive, quantitative and qualitative techniques were also utilized. Quantitative data were taken from the pretest-posttest results on the Test on Conceptual Understanding, Science Process Skills and Chemistry Attitudinaire. Qualitative data were drawn from the experts’ assessment of the developed lessons and research instruments, and the insights of students and teacher. The developed lessons integrating UNESCO ICT-based instructional materials were Atomic Model and Structure, Periodic Table of Elements, Chemical Bonding, and Balancing Chemical Equation. These lessons increased the conceptual understanding of the students by topic and skill from very low mastery to average mastery level. The students have slightly improved along the different science process skills. After teaching the lessons, the students’ attitude also improved. The students became more motivated and interested in Chemistry and the lessons were student centered and entailed teacher’s competence and flexibility in computer use.

Combinatorial materials synthesis and high-throughput screening: an integrated materials chip approach to mapping phase diagrams and discovery and optimization of functional materials.

Science.gov (United States)

Xiang, X D

Combinatorial materials synthesis methods and high-throughput evaluation techniques have been developed to accelerate the process of materials discovery and optimization and phase-diagram mapping. Analogous to integrated circuit chips, integrated materials chips containing thousands of discrete different compositions or continuous phase diagrams, often in the form of high-quality epitaxial thin films, can be fabricated and screened for interesting properties. Microspot x-ray method, various optical measurement techniques, and a novel evanescent microwave microscope have been used to characterize the structural, optical, magnetic, and electrical properties of samples on the materials chips. These techniques are routinely used to discover/optimize and map phase diagrams of ferroelectric, dielectric, optical, magnetic, and superconducting materials.

Phase change materials in energy sector - applications and material requirements

Science.gov (United States)

Kuta, Marta; Wójcik, Tadeusz M.

2015-05-01

Phase change materials (PCMs) have been applying in many areas. One of them is energy field. PCMs are interesting for the energy sector because their use enables thermal stabilization and storage of large amount of heat. It is major issue for safety of electronic devices, thermal control of buildings and vehicles, solar power and many others energy domains. This paper contains preliminary results of research on solid-solid phase change materials designed for thermal stabilisation of electronic devices.

Development, Implementation, and Assessment of Climate Curricular Materials for Introductory Undergraduates: Lessons Learned from the InTeGrate Project's Climate of Change Module

Science.gov (United States)

Walker, B.; Fadem, C. M.; Shellito, L. J.

2014-12-01

Designing climate change curricular materials suitable for wide adoption across institutions and academic disciplines (including those outside of the geosciences) requires collaboration among faculty at different types of institutions and consideration of a variety of student populations, learning styles, and course formats. The Interdisciplinary Teaching of Geoscience for a Sustainable Future (InTeGrate) project, an NSF STEP Center program, provides opportunities for faculty to develop 2-3 week teaching modules to engage students in understanding the intersections between geoscience topics and societal issues. From 2012-2014, a team of 3 faculty from a liberal arts college, comprehensive university, and community college developed, implemented, assessed, and revised a 2-3 week module for introductory undergraduates entitled "Climate of change: interactions and feedbacks between water, air, and ice". The module uses authentic atmosphere, ocean, and cryosphere data from several regions to illustrate how climate impacts human societies and that the climate system has interacting components complicated by feedbacks, uncertainties, and human behavioral decisions. Students also consider past and present human adaptations to climate fluctuations. The module was piloted in introductory geology, meteorology, and oceanography courses during the 2012-2013 academic year, during which time formative and summative assessments were administered and used to modify the curricular materials. We will provide an overview of the module's content, instructional strategies involved in implementing the module, and methods of formative and summative assessment. We will also report on lessons learned during the development, piloting, revision, and publishing process, the importance of fostering partnerships between faculty from different institution types, and design approaches that promote widespread adoption of climate curricular materials.

The Changing Materiality of Music

DEFF Research Database (Denmark)

Bødker, Henrik

A great deal of effort has gone into discussing issues of copyright in relation to the new materialities of the digital distribution of popular music; there has, however, been less focus on the changes that these new developments may invoke with respect to the cultural and social usages of music....... Against the backdrop of recent discussions of popular music as material culture it is argued that emergent usages must be seen in relation to accumulations of different materialities and that such a perspective highlights issues related to both aesthetic reflexivity and agency. Keywords: cultural...... commodity, materiality, reflexivity, music, MP3...

A study of non destructive integrity assessment method for structural materials of nuclear reactor. Part 2

International Nuclear Information System (INIS)

Totsuka, Nobuo; Matsuzaki, Akihiro

2011-01-01

The hardness measurement is one of the most effective way for non destructive integrity assessment evaluating structural materials of nuclear power plants before and after suffering an earthquake. Then an actual evaluation method and effectiveness of the method using portable hardness tester has been reported in the previous Journal. In this study, the developing method which can evaluate more accurately the amount of plastic deformation of the material caused by an earthquake has been reported, based on the experimental results about the hardness change of the material considering the thermal aging due to the plant operation and the cyclic deformation suffered by an earthquake. (author)

Material integrity verification radar

International Nuclear Information System (INIS)

Koppenjan, S.K.

1999-01-01

The International Atomic Energy Agency (IAEA) has the need for verification of 'as-built' spent fuel-dry storage containers and other concrete structures. The IAEA has tasked the Special Technologies Laboratory (STL) to fabricate, test, and deploy a stepped-frequency Material Integrity Verification Radar (MIVR) system to nondestructively verify the internal construction of these containers. The MIVR system is based on previously deployed high-frequency, ground penetrating radar (GPR) systems that have been developed by STL for the U.S. Department of Energy (DOE). Whereas GPR technology utilizes microwave radio frequency energy to create subsurface images, MTVR is a variation for which the medium is concrete instead of soil. The purpose is to nondestructively verify the placement of concrete-reinforcing materials, pipes, inner liners, and other attributes of the internal construction. The MIVR system underwent an initial field test on CANDU reactor spent fuel storage canisters at Atomic Energy of Canada Limited (AECL), Chalk River Laboratories, Ontario, Canada, in October 1995. A second field test at the Embalse Nuclear Power Plant in Embalse, Argentina, was completed in May 1996. The DOE GPR also was demonstrated at the site. Data collection and analysis were performed for the Argentine National Board of Nuclear Regulation (ENREN). IAEA and the Brazilian-Argentine Agency for the Control and Accounting of Nuclear Material (ABACC) personnel were present as observers during the test. Reinforcing materials were evident in the color, two-dimensional images produced by the MIVR system. A continuous pattern of reinforcing bars was evident and accurate estimates on the spacing, depth, and size were made. The potential uses for safeguard applications were jointly discussed. The MIVR system, as successfully demonstrated in the two field tests, can be used as a design verification tool for IAEA safeguards. A deployment of MIVR for Design Information Questionnaire (DIQ

Application of phase-change materials in memory taxonomy

OpenAIRE

Wang, Lei; Tu, Liang; Wen, Jing

2017-01-01

Abstract Phase-change materials are suitable for data storage because they exhibit reversible transitions between crystalline and amorphous states that have distinguishable electrical and optical properties. Consequently, these materials find applications in diverse memory devices ranging from conventional optical discs to emerging nanophotonic devices. Current research efforts are mostly devoted to phase-change random access memory, whereas the applications of phase-change materials in other...

Aging mechanisms in amorphous phase-change materials.

Science.gov (United States)

Raty, Jean Yves; Zhang, Wei; Luckas, Jennifer; Chen, Chao; Mazzarello, Riccardo; Bichara, Christophe; Wuttig, Matthias

2015-06-24

Aging is a ubiquitous phenomenon in glasses. In the case of phase-change materials, it leads to a drift in the electrical resistance, which hinders the development of ultrahigh density storage devices. Here we elucidate the aging process in amorphous GeTe, a prototypical phase-change material, by advanced numerical simulations, photothermal deflection spectroscopy and impedance spectroscopy experiments. We show that aging is accompanied by a progressive change of the local chemical order towards the crystalline one. Yet, the glass evolves towards a covalent amorphous network with increasing Peierls distortion, whose structural and electronic properties drift away from those of the resonantly bonded crystal. This behaviour sets phase-change materials apart from conventional glass-forming systems, which display the same local structure and bonding in both phases.

Toward an Evolutive and Tightly Integrated Information System for Nuclear Materials Management

Energy Technology Data Exchange (ETDEWEB)

Dessoude, O. [Euriware (Areva Group), 25 avenue de Tourville, Equeurdreville, 50100 (France)

2009-06-15

From a nuclear materials management standpoint, spent-fuel recycling is considered a very challenging activity. This challenge has its positive counterpart as a lot has been learned from confronting a large variety of nuclear materials, complex material transfers and transformations. Since the inception of its computerized nuclear materials management system, AREVA NC La Hague has relied upon its IT subsidiary EURIWARE for software design and development. In 2003, the founding milestone was the implementation of the new GMP software package (Gestion des Matieres et des Produits - Materials and Products Management). GMP was underpinned by the following principles: reliability, transparency and close integration with the process control layer, so as to mitigate human errors and keep the management process smooth and efficient. In 2005, another major milestone was reached with CMNR (Comptabilite des Matieres Nucleaires Reglementaire - Regulatory Nuclear Materials Accountancy), a system in charge of local accounting and multi-site consolidation at corporate level. In spite of an auspicious start, GMP came up against the same stumbling block as many information systems: the multiplication of interfaces and technologies (entropy increasing over time). For the sake of maintenance, evolutions and performance, AREVA has decided a progressive modernization of its Nuclear Materials Management (NMM) information system. The underlying principle is a clear separation between the main functions: - Physical Follow-up, performed at the plant-level, - Regulatory Accountancy (for IRSN, EURATOM and IAEA safeguards), offering consolidation at the corporate level, - Patrimonial Accountancy (allocation of materials and conditioned wastes to AREVA's customers). The pivotal piece of this multi-year programme is the implementation of a dedicated data repository. We describe its main building blocks and demonstrate how it helps in managing changes to regulation, products, customers and

Payment changes require integrating records.

Science.gov (United States)

Palley, M A

1990-06-01

The greatest challenges for healthcare organizations facing radical changes in their payment and reporting structures lie in finding ways to integrate various forms of patient information. An analysis of how three New York City hospitals dealt with their state's switch to an all-payer diagnosis related group-based payment system reveals strengths and weaknesses in their existing information systems and in steps taken to adapt to the change.

Entrainment of bed material by Earth-surface mass flows: review and reformulation of depth-integrated theory

Science.gov (United States)

Iverson, Richard M.; Chaojun Ouyang,

2015-01-01

Earth-surface mass flows such as debris flows, rock avalanches, and dam-break floods can grow greatly in size and destructive potential by entraining bed material they encounter. Increasing use of depth-integrated mass- and momentum-conservation equations to model these erosive flows motivates a review of the underlying theory. Our review indicates that many existing models apply depth-integrated conservation principles incorrectly, leading to spurious inferences about the role of mass and momentum exchanges at flow-bed boundaries. Model discrepancies can be rectified by analyzing conservation of mass and momentum in a two-layer system consisting of a moving upper layer and static lower layer. Our analysis shows that erosion or deposition rates at the interface between layers must in general satisfy three jump conditions. These conditions impose constraints on valid erosion formulas, and they help determine the correct forms of depth-integrated conservation equations. Two of the three jump conditions are closely analogous to Rankine-Hugoniot conditions that describe the behavior of shocks in compressible gasses, and the third jump condition describes shear traction discontinuities that necessarily exist across eroding boundaries. Grain-fluid mixtures commonly behave as compressible materials as they undergo entrainment, because changes in bulk density occur as the mixtures mobilize and merge with an overriding flow. If no bulk density change occurs, then only the shear-traction jump condition applies. Even for this special case, however, accurate formulation of depth-integrated momentum equations requires a clear distinction between boundary shear tractions that exist in the presence or absence of bed erosion.

Phase-change materials for non-volatile memory devices: from technological challenges to materials science issues

Science.gov (United States)

Noé, Pierre; Vallée, Christophe; Hippert, Françoise; Fillot, Frédéric; Raty, Jean-Yves

2018-01-01

Chalcogenide phase-change materials (PCMs), such as Ge-Sb-Te alloys, have shown outstanding properties, which has led to their successful use for a long time in optical memories (DVDs) and, recently, in non-volatile resistive memories. The latter, known as PCM memories or phase-change random access memories (PCRAMs), are the most promising candidates among emerging non-volatile memory (NVM) technologies to replace the current FLASH memories at CMOS technology nodes under 28 nm. Chalcogenide PCMs exhibit fast and reversible phase transformations between crystalline and amorphous states with very different transport and optical properties leading to a unique set of features for PCRAMs, such as fast programming, good cyclability, high scalability, multi-level storage capability, and good data retention. Nevertheless, PCM memory technology has to overcome several challenges to definitively invade the NVM market. In this review paper, we examine the main technological challenges that PCM memory technology must face and we illustrate how new memory architecture, innovative deposition methods, and PCM composition optimization can contribute to further improvements of this technology. In particular, we examine how to lower the programming currents and increase data retention. Scaling down PCM memories for large-scale integration means the incorporation of the PCM into more and more confined structures and raises materials science issues in order to understand interface and size effects on crystallization. Other materials science issues are related to the stability and ageing of the amorphous state of PCMs. The stability of the amorphous phase, which determines data retention in memory devices, can be increased by doping the PCM. Ageing of the amorphous phase leads to a large increase of the resistivity with time (resistance drift), which has up to now hindered the development of ultra-high multi-level storage devices. A review of the current understanding of all these

Monitoring of laser material processing using machine integrated low-coherence interferometry

Science.gov (United States)

Kunze, Rouwen; König, Niels; Schmitt, Robert

2017-06-01

Laser material processing has become an indispensable tool in modern production. With the availability of high power pico- and femtosecond laser sources, laser material processing is advancing into applications, which demand for highest accuracies such as laser micro milling or laser drilling. In order to enable narrow tolerance windows, a closedloop monitoring of the geometrical properties of the processed work piece is essential for achieving a robust manufacturing process. Low coherence interferometry (LCI) is a high-precision measuring principle well-known from surface metrology. In recent years, we demonstrated successful integrations of LCI into several different laser material processing methods. Within this paper, we give an overview about the different machine integration strategies, that always aim at a complete and ideally telecentric integration of the measurement device into the existing beam path of the processing laser. Thus, highly accurate depth measurements within machine coordinates and a subsequent process control and quality assurance are possible. First products using this principle have already found its way to the market, which underlines the potential of this technology for the monitoring of laser material processing.

Multilevel integration of patternable low-κ material into advanced Cu BEOL

Science.gov (United States)

Lin, Qinghuang; Chen, S. T.; Nelson, A.; Brock, P.; Cohen, S.; Davis, B.; Fuller, N.; Kaplan, R.; Kwong, R.; Liniger, E.; Neumayer, D.; Patel, J.; Shobha, H.; Sooriyakumaran, R.; Purushothaman, S.; Spooner, T.; Miller, R.; Allen, R.; Wisnieff, R.

2010-04-01

In this paper, we wish to report, for the first time, on a simple, low-cost, novel way to form dual-damascene copper (Cu) on-chip interconnect or Back-End-Of-the-Line (BEOL) structures using a patternable low dielectric constant (low-κ) dielectric material concept. A patternable low-κ dielectric material combines the functions of a traditional resist and a dielectric material into one single material. It acts as a traditional resist during patterning and is subsequently converted to a low-κ dielectric material during a post-patterning curing process. No sacrificial materials (separate resists or hardmasks) and their related deposition, pattern transfer (etch) and removal (strip) are required to form dual-damascene BEOL patterns. We have successfully demonstrated multi-level dual-damascene integration of a novel patternable low-κ dielectric material into advanced Cu BEOL. This κ=2.7 patternable low-κ material is based on the industry standard SiCOH-based (silsesquioxane polymer) material platform and is compatible with 248 nm optical lithography. Multilevel integration of this patternable low-κ material at 45 nm node Cu BEOL fatwire levels has been demonstrated with very high electrical yields using the current manufacturing infrastructure.

Integrated assessment models of climate change. An incomplete overview

International Nuclear Information System (INIS)

Dowlatabadi, H.

1995-01-01

Integrated assessment is a trendy phrase that has recently entered the vocabulary of folks in Washington, DC and elsewhere. The novelty of the term in policy analysis and policy making circles belies the longevity of this approach in the sciences and past attempts at their application to policy issues. This paper is an attempt at providing an overview of integrated assessment with a special focus on policy motivated integrated assessments of climate change. The first section provides an introduction to integrated assessments in general, followed by a discussion of the bounds to the climate change issue. The next section is devoted to a taxonomy of the policy motivated models. Then the integrated assessment effort at Carnegie Mellon is described briefly. A perspective on the challenges ahead in successful representation of natural and social dynamics in integrated assessments of global climate change is presented in the final section. (Author)

Materials science. Materials that couple sensing, actuation, computation, and communication.

Science.gov (United States)

McEvoy, M A; Correll, N

2015-03-20

Tightly integrating sensing, actuation, and computation into composites could enable a new generation of truly smart material systems that can change their appearance and shape autonomously. Applications for such materials include airfoils that change their aerodynamic profile, vehicles with camouflage abilities, bridges that detect and repair damage, or robotic skins and prosthetics with a realistic sense of touch. Although integrating sensors and actuators into composites is becoming increasingly common, the opportunities afforded by embedded computation have only been marginally explored. Here, the key challenge is the gap between the continuous physics of materials and the discrete mathematics of computation. Bridging this gap requires a fundamental understanding of the constituents of such robotic materials and the distributed algorithms and controls that make these structures smart. Copyright © 2015, American Association for the Advancement of Science.

Thermal Energy Storage with Phase Change Material

Directory of Open Access Journals (Sweden)

Lavinia Gabriela SOCACIU

2012-08-01

Full Text Available Thermal energy storage (TES systems provide several alternatives for efficient energy use and conservation. Phase change materials (PCMs for TES are materials supplying thermal regulation at particular phase change temperatures by absorbing and emitting the heat of the medium. TES in general and PCMs in particular, have been a main topic in research for the last 30 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. PCMs absorb energy during the heating process as phase change takes place and release energy to the environment in the phase change range during a reverse cooling process. PCMs possesses the ability of latent thermal energy change their state with a certain temperature. PCMs for TES are generally solid-liquid phase change materials and therefore they need encapsulation. TES systems using PCMs as a storage medium offers advantages such as high TES capacity, small unit size and isothermal behaviour during charging and discharging when compared to the sensible TES.

Implicit integration of plasticity models for granular materials

DEFF Research Database (Denmark)

Ahadi, A.; Krenk, Steen

2003-01-01

A stress integration algorithm for granular materials based on fully implicit integration with explicit updating is presented. In the implicit method the solution makes use of the gradient to the potential surface at the final stress state which is unknown. The final stress and hardening parameters...... stresses are not supported the functions and their derivatives are not representative outside the compressive octant of the principal stress space. The elastic predictor is therefore preconditioned in order to ensure that the first predictor is within the valid region. Capability and robustness...

Structural integrity of materials in nuclear service: a bibliography

International Nuclear Information System (INIS)

Heddleson, F.A.

1977-01-01

This report contains 679 abstracts from the Nuclear Safety Information Center (NSIC) computer file dated 1973 through 1976 covering material properties with respect to structural integrity. All materials important to the nuclear industry (except concrete) are covered for mechanical properties, chemical properties, corrosion, fracture or failure, radiation damage, creep, cracking, and swelling. Keyword, author, and permuted-title indexes are included for the convenience of the user

Structural integrity of materials in nuclear service: a bibliography

Energy Technology Data Exchange (ETDEWEB)

Heddleson, F.A.

1977-06-07

This report contains 679 abstracts from the Nuclear Safety Information Center (NSIC) computer file dated 1973 through 1976 covering material properties with respect to structural integrity. All materials important to the nuclear industry (except concrete) are covered for mechanical properties, chemical properties, corrosion, fracture or failure, radiation damage, creep, cracking, and swelling. Keyword, author, and permuted-title indexes are included for the convenience of the user.

Heat storage system utilizing phase change materials government rights

Science.gov (United States)

Salyer, Ival O.

2000-09-12

A thermal energy transport and storage system is provided which includes an evaporator containing a mixture of a first phase change material and a silica powder, and a condenser containing a second phase change material. The silica powder/PCM mixture absorbs heat energy from a source such as a solar collector such that the phase change material forms a vapor which is transported from the evaporator to the condenser, where the second phase change material melts and stores the heat energy, then releases the energy to an environmental space via a heat exchanger. The vapor is condensed to a liquid which is transported back to the evaporator. The system allows the repeated transfer of thermal energy using the heat of vaporization and condensation of the phase change material.

Unconscious learning processes: mental integration of verbal and pictorial instructional materials.

Science.gov (United States)

Kuldas, Seffetullah; Ismail, Hairul Nizam; Hashim, Shahabuddin; Bakar, Zainudin Abu

2013-12-01

This review aims to provide an insight into human learning processes by examining the role of cognitive and emotional unconscious processing in mentally integrating visual and verbal instructional materials. Reviewed literature shows that conscious mental integration does not happen all the time, nor does it necessarily result in optimal learning. Students of all ages and levels of experience cannot always have conscious awareness, control, and the intention to learn or promptly and continually organize perceptual, cognitive, and emotional processes of learning. This review suggests considering the role of unconscious learning processes to enhance the understanding of how students form or activate mental associations between verbal and pictorial information. The understanding would assist in presenting students with spatially-integrated verbal and pictorial instructional materials as a way of facilitating mental integration and improving teaching and learning performance.

Global change integrating factors: Tropical tropopause trends

International Nuclear Information System (INIS)

Reck, R.A.

1994-01-01

This research proposes new criteria, shifts in the height and temperature of the tropical tropopause, as measures of global climate change. The search for signs of global warming in the temperature signal near the earth's surface is extremely difficult, largely because numerous factors contribute to surface temperature forcing with only a small signal-to-noise ratio relative to long-term effects. In the long term, no part of the atmosphere can be considered individually because the evolution will be a function of all states of all portions. A large surface greenhouse signal might ultimately be expected, but the analysis of surface temperature may not be particularly useful for early detection. What is suggested here is not an analysis of trends in the surface temperature field or any of its spatial averages, but rather an integrating factor or integrator, a single measure of global change that could be considered a test of significant change for the entire global system. Preferably, this global change integrator would vary slowly and would take into account many of the causes of climate change, with a relatively large signal-to-noise ratio. Such an integrator could be monitored, and abrupt or accelerated changes could serve as an early warning signal for policy makers and the public. Earlier work has suggested that temperature has much less short-term and small-scale noise in the lower stratosphere, and thus the global warming signal at that level might be more easily deconvoluted, because the cooling rate near the 200-mb level is almost constant with latitude. A study of the temperature signal at this pressure level might show a clearer trend due to increased levels of greenhouse gases, but it would yield information about the troposphere only by inference

Phase change materials handbook

Science.gov (United States)

Hale, D. V.; Hoover, M. J.; Oneill, M. J.

1971-01-01

This handbook is intended to provide theory and data needed by the thermal design engineer to bridge the gap between research achievements and actual flight systems, within the limits of the current state of the art of phase change materials (PCM) technology. The relationship between PCM and more conventional thermal control techniques is described and numerous space and terrestrial applications of PCM are discussed. Material properties of the most promising PCMs are provided; the purposes and use of metallic filler materials in PCM composites are presented; and material compatibility considerations relevant to PCM design are included. The engineering considerations of PCM design are described, especially those pertaining to the thermodynamic and heat transfer phenomena peculiar to PCM design. Methods of obtaining data not currently available are presented. The special problems encountered in the space environment are described. Computational tools useful to the designer are discussed. In summary, each aspect of the PCM problem important to the design engineer is covered to the extent allowed by the scope of this effort and the state of the art.

Climate changes, raw materials shortage, and economic development

International Nuclear Information System (INIS)

Joest, F.

1994-01-01

The possibility of a climate change being brought about by our national economies has dominated the national and international ecopolitical discussion of the past few years like no other topic. The present study is an attempt at an as comprehensive an examination as possible of this problem. It works from the assumption that examining and solving environmental problems requires the cooperation and creativity of investigators from different disciplines. It accordingly develops a concept permitting an integration of scientific, economic, and ethical questions impinging on the problem of the greenhouse effect. Thus the study contributes to the groundwork of an ecological economics. The interdisciplinary approach to analysing the connections between climate changes, raw materials consumption, and economic development is variously seen to pinpoint the complex temporal structure of the problems. It becomes clear that ecopolitical measures take a long time to actually become effective. Besides shifiting the focus to questions as to the scope and limits of politico-economic action, the temporal strucutre of the problem also reveals the limitations of scientifically founded ecopolitical recommendations. This brings the ethical aspect of analysing and solving environmental problems to the fore. (orig./UA) [de

A reference device for evaluating the thermal behavior of installed multilayered wall containing a phase change material

International Nuclear Information System (INIS)

Pagliolico, S.L.; Sassi, G.; Cascone, Y.; Bongiovanni, R.M.

2015-01-01

Highlights: • Thermal analysis of installed wallboards embedding phase change material layer. • Simple devices and real conditions for thermal analysis toward a standardization. • Scanning calorimetric measurements as initial condition for data regression. • Bias correction of calorimetric measurements data by installation factors. • Practical approach to identify a reliable thermal curve for capacitive wallboards. - Abstract: Thermal inertia of lightweight building envelopes can be improved including phase change materials in multilayered wallboards. The thermal modeling of buildings for design purposes needs a robust description of the thermal properties of installed phase change materials. A standard method would improve the thermal characterization of commercial products. The aim of the study is to develop a simple methodology to obtain reliable thermal data for phase change materials integrated in multilayered wallboards. The methodology modifies differential scanning calorimetry measurements on phase change material by installation factors to obtain the apparent specific heat vs. temperature for the wallboard layer embedding phase change material. Simple cubic cells were realized as reference devices to simulate a confined environment. A dynamic model of heat transfer was developed to simulate the thermal behavior of devices. Installation factors were calculated by regression of the monitored temperatures inside and outside the devices operating under real environmental conditions. The apparent specific heat of phase change material, measured by differential scanning calorimetry at different rates, resulted in a spread of curves vs. temperature. Mean curves were used as initial condition for regression. The mean calculation method did not significantly affect the installed resulted curve. A unique curve of apparent specific heat vs. temperature best fit data measured over a wide range of experimental devices and conditions. Good regression

Encapsulation of Phase Change Materials Using Layer-by-Layer Assembled Polyelectrolytes

Directory of Open Access Journals (Sweden)

Qiangying Yi

2015-01-01

Full Text Available Phase change materials absorb the thermal energy when changing their phases (e.g., solid-to-liquid at constant temperatures to achieve the latent heat storage. The major drawbacks such as limited thermal conductivity and leakage prevent the PCMs from wide application in desired areas. In this work, an environmentally friendly and low cost approach, layer-by-layer (LbL assembly technique, was applied to build up ultrathin shells to encapsulate the PCMs and therefore to regulate their changes in volume when the phase change occurs. Generally, the oppositely charged strong polyelectrolytes Poly(diallyldimethylammonium chloride (PDADMAC and Poly(4-styrenesulfonic acid sodium salt (PSS were employed to fabricate multilayer shells on emulsified octadecane droplets using either bovine serum albumin (BSA or sodium dodecyl sulfate (SDS as surfactant. Specifically, using BSA as the surfactant, polyelectrolyte encapsulated octadecane spheres in size of ∼500 nm were obtained, with good shell integrity, high octadecane content (91.3% by mass, and good thermal stability after cycles of thermal treatments.

Integrated Computational Materials Engineering (ICME) for Third Generation Advanced High-Strength Steel Development

Energy Technology Data Exchange (ETDEWEB)

Savic, Vesna; Hector, Louis G.; Ezzat, Hesham; Sachdev, Anil K.; Quinn, James; Krupitzer, Ronald; Sun, Xin

2015-06-01

This paper presents an overview of a four-year project focused on development of an integrated computational materials engineering (ICME) toolset for third generation advanced high-strength steels (3GAHSS). Following a brief look at ICME as an emerging discipline within the Materials Genome Initiative, technical tasks in the ICME project will be discussed. Specific aims of the individual tasks are multi-scale, microstructure-based material model development using state-of-the-art computational and experimental techniques, forming, toolset assembly, design optimization, integration and technical cost modeling. The integrated approach is initially illustrated using a 980 grade transformation induced plasticity (TRIP) steel, subject to a two-step quenching and partitioning (Q&P) heat treatment, as an example.

Integrative change model in psychotherapy: Perspectives from Indian thought.

Science.gov (United States)

Manickam, L S S

2013-01-01

Different psychotherapeutic approaches claim positive changes in patients as a result of therapy. Explanations related to the change process led to different change models. Some of the change models are experimentally oriented whereas some are theoretical. Apart from the core models of behavioral, psychodynamic, humanistic, cognitive and spiritually oriented models there are specific models, within psychotherapy that explains the change process. Integrative theory of a person as depicted in Indian thought provides a common ground for the integration of various therapies. Integrative model of change based on Indian thought, with specific reference to psychological concepts in Upanishads, Ayurveda, Bhagavad Gita and Yoga are presented. Appropriate psychological tools may be developed in order to help the clinicians to choose the techniques that match the problem and the origin of the dimension. Explorations have to be conducted to develop more techniques that are culturally appropriate and clinically useful. Research has to be initiated to validate the identified concepts.

Vibration damping and heat transfer using material phase changes

Science.gov (United States)

Kloucek, Petr [Houston, TX; Reynolds, Daniel R [Oakland, CA

2009-03-24

A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.

Vibration damping and heat transfer using material phase changes

Science.gov (United States)

Kloucek, Petr (Inventor); Reynolds, Daniel R. (Inventor)

2009-01-01

A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.

Theory of absorption integrated optical sensor of gaseous materials

Science.gov (United States)

Egorov, A. A.

2010-10-01

The eigen and noneigen (leaky) modes of a three-layer planar integrated optical waveguide are described. The dispersion relation of a three-layer planar waveguide and other dependences are derived, and the cutoff conditions are analyzed. The diagram of propagation constants of the guided and radiation modes of an irregular asymmetric three-layer waveguide and the dependence of the electric field amplitudes of radiation modes of substrate on vertical coordinate in a tantalum integrated optical waveguide are presented. The operating principles of an absorption integrated optical waveguide sensor are investigated. The dependences of sensitivity of an integrated optical waveguide sensor on the sensory cell length, the coupling efficiency of the laser radiation into the waveguide, the absorption cross-section of the studied material, and the level of additive statistical noise are investigated. Some of the prospective areas of application of integrated-optical waveguide sensors are outlined.

Quality criteria for phase change materials selection

International Nuclear Information System (INIS)

Vitorino, Nuno; Abrantes, João C.C.; Frade, Jorge R.

2016-01-01

Highlights: • Selection criteria of phase change materials for representative applications. • Selection criteria based on reliable solutions for latent heat transfer. • Guidelines for the role of geometry and heat transfer mechanisms. • Performance maps based on PCM properties, operating conditions, size and time scales. - Abstract: Selection guidelines are primary criterion for optimization of materials for specific applications in order to meet simultaneous and often conflicting requirements. This is mostly true for technologies and products required to meet the main societal needs, such as energy. In this case, gaps between supply and demand require strategies for energy conversion and storage, including thermal storage mostly based on phase change materials. Latent heat storage is also very versatile for thermal management and thermal control by allowing high storage density within narrow temperature ranges without strict dependence between stored thermal energy and temperature. Thus, this work addressed the main issues of latent heat storage from a materials selection perspective, based on expected requirements of applications in thermal energy storage or thermal regulation. Representative solutions for the kinetics of latent heat charge/discharge were used to derive optimization guidelines for high energy density, high power, response time (from fast response to thermal inertia), etc. The corresponding property relations were presented in graphical forms for a wide variety of prospective phase change materials, and for wide ranges of operating conditions, and accounting for changes in geometry and mechanisms.

Disorder-induced localization in crystalline phase-change materials.

Science.gov (United States)

Siegrist, T; Jost, P; Volker, H; Woda, M; Merkelbach, P; Schlockermann, C; Wuttig, M

2011-03-01

Localization of charge carriers in crystalline solids has been the subject of numerous investigations over more than half a century. Materials that show a metal-insulator transition without a structural change are therefore of interest. Mechanisms leading to metal-insulator transition include electron correlation (Mott transition) or disorder (Anderson localization), but a clear distinction is difficult. Here we report on a metal-insulator transition on increasing annealing temperature for a group of crystalline phase-change materials, where the metal-insulator transition is due to strong disorder usually associated only with amorphous solids. With pronounced disorder but weak electron correlation, these phase-change materials form an unparalleled quantum state of matter. Their universal electronic behaviour seems to be at the origin of the remarkable reproducibility of the resistance switching that is crucial to their applications in non-volatile-memory devices. Controlling the degree of disorder in crystalline phase-change materials might enable multilevel resistance states in upcoming storage devices.

Subthreshold electrical transport in amorphous phase-change materials

International Nuclear Information System (INIS)

Gallo, Manuel Le; Kaes, Matthias; Sebastian, Abu; Krebs, Daniel

2015-01-01

Chalcogenide-based phase-change materials play a prominent role in information technology. In spite of decades of research, the details of electrical transport in these materials are still debated. In this article, we present a unified model based on multiple-trapping transport together with 3D Poole–Frenkel emission from a two-center Coulomb potential. With this model, we are able to explain electrical transport both in as-deposited phase-change material thin films, similar to experimental conditions in early work dating back to the 1970s, and in melt-quenched phase-change materials in nanometer-scale phase-change memory devices typically used in recent studies. Experimental measurements on two widely different device platforms show remarkable agreement with the proposed mechanism over a wide range of temperatures and electric fields. In addition, the proposed model is able to seamlessly capture the temporal evolution of the transport properties of the melt-quenched phase upon structural relaxation. (paper)

Phase change material thermal capacitor clothing

Science.gov (United States)

Buckley, Theresa M. (Inventor)

2005-01-01

An apparatus and method for metabolic cooling and insulation of a user in a cold environment. In its preferred embodiment the apparatus is a highly flexible composite material having a flexible matrix containing a phase change thermal storage material. The apparatus can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The apparatus may also include an external thermal insulation layer and/or an internal thermal control layer to regulate the rate of heat exchange between the composite and the skin of the wearer. Other embodiments of the apparatus also provide 1) a path for evaporation or direct absorption of perspiration from the skin of the wearer for improved comfort and thermal control, 2) heat conductive pathways within the material for thermal equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal socks, gloves and a face mask for cold weather activities, and a metabolic heating or cooling blanket useful for treating hypothermia or fever patients in a medical setting and therapeutic heating or cooling orthopedic joint supports.

Phase change materials in non-volatile storage

OpenAIRE

Ielmini, Daniele; Lacaita, Andrea L.

2011-01-01

After revolutionizing the technology of optical data storage, phase change materials are being adopted in non-volatile semiconductor memories. Their success in electronic storage is mostly due to the unique properties of the amorphous state where carrier transport phenomena and thermally-induced phase change cooperate to enable high-speed, low-voltage operation and stable data retention possible within the same material. This paper reviews the key physical properties that make this phase so s...

Improvement of Students’ Environmental Literacy by Using Integrated Science Teaching Materials

Science.gov (United States)

Suryanti, D.; Sinaga, P.; Surakusumah, W.

2018-02-01

This study aims to determine the improvement of student environmental literacy through the use of integrated science teaching materials on pollution topics. The research is used weak experiment method with the one group pre-test post-test design. The sample of the study were junior high school students in Bandung amounted to 32 people of 7th grade. Data collection in the form of environmental literacy test instrument consist of four components of environmental literacy that is (1) Knowledge, (2) Competencies (Cognitive Skill), (3) Affective and (4) Environmentally Responsible Behavior. The results show that the student’s environmental literacy ability is improved after using integrated science teaching materials. An increase in the medium category is occurring in the knowledge (N-gain=46%) and cognitive skill (N-gain=31%), while the increase in the low category occurs in the affective component (N-gain=25%) and behaviour (N-gain=24%). The conclusions of this study as a whole the improvement of students’ environmental literacy by using integrated science teaching material is in the medium category (N-gain=34%).

Evaluation and recommendations for work group integration within the Materials and Processes Lab

Science.gov (United States)

Farrington, Phillip A.

1992-01-01

The goal of this study was to evaluate and make recommendations for improving the level of integration of several work groups within the Materials and Processes Lab at the Marshall Space Flight Center. This evaluation has uncovered a variety of projects that could improve the efficiency and operation of the work groups as well as the overall integration of the system. In addition, this study provides the foundation for specification of a computer integrated manufacturing test bed environment in the Materials and Processes Lab.

Role of materials accounting in integrated safeguards systems for reprocessing plants

International Nuclear Information System (INIS)

Hakkila, E.A.; Gutmacher, R.G.; Markin, J.T.; Shipley, J.P.; Whitty, W.J.

1981-01-01

Integration of materials accounting and containment/surveillance techniques for international safeguards requires careful examination and definition of suitable inspector activities for verification of operator's materials accounting data. The inspector's verification procedures are designed to protect against data falsification and/or the use of measurement uncertainties to conceal missing material. Materials accounting activities are developed to provide an effective international safeguards system when combined with containment/surveillance activities described in a companion paper

Integrated Computational Material Engineering Technologies for Additive Manufacturing, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — QuesTek Innovations, a pioneer in Integrated Computational Materials Engineering (ICME) and a Tibbetts Award recipient, is teaming with University of Pittsburgh,...

Astrophysics Laboratory-Based Lecture Material Development of Solarscope with Integration and Interconnection

Directory of Open Access Journals (Sweden)

Asih Melati

2015-12-01

Full Text Available The development of laboratory-based lecture materials with integrated and interconnected value is a requirement for study and practical materials and in line with the vision and mission of UIN Sunan Kalijaga. As a result, the optimization of laboratory’s equipment is urgently needed. Although UIN Sunan Kalijaga Laboratory have had Solarscope telescope – which have a guidebook in German language – for six years, it was not optimally used even it can be used to satisfy the desires to observe astronomical objects economically, accurately and easy to operate. Based on above, this research propose to create a lab-work module for Solarscope with integration and interconnection value. This research used 4D methodology (Define, Design, Develop and Disseminate and have passed the assessment and validation phase from material, media and integrated-interconnected value experts. The data analysis of the module which was mapped by Sukarja into 5 scale mark resulted in good grade in the module assessment by material experts with 80% from the ideal mark with most of the complaint is in the formula typing which is not clear in its derivative. The module assessment by media experts scored very good grade with 88.89% from the ideal mark regarding the content and the figures of the module. Lastly, from the integrated-interconnected value experts marked in good grade with 73.50% from the ideal mark and suggested the addition of supported Al-Qur’an verses and relevant exclamation of the Al-Qur’an’s passages. With all of these assessment results, this module can be used as the material of astrophysics lab-work and for supporting students’ researches with integration-interconnection value and enhance the university’s book collection which will support the vision and mission of UIN Sunan Kalijaga

THE DEVELOPMENT OF AIR-THEME INTEGRATED SCIENCE TEACHING MATERIAL USING FOUR STEPS TEACHING MATERIAL DEVELOPMENT

Directory of Open Access Journals (Sweden)

A. Arifin

2016-01-01

Full Text Available The purposes of this study are to develop, to test the feasibility, to describe the characteristic, and to test the students understanding about integrated science teaching material about air using Four Steps Teaching Material Development (4S TMD. The Research and Development method was use to develop integrated science teaching materials which is involving  all science perspectives that are not presented in junior high school science book. The air theme was chosen in this study since it can be explained using biology, chemistry, physics, and earth and space science  perspectives. Development the teaching materials was consists of selection, structuring, characterization, and reduction didactic steps. Based on the of feasibility test results, the teaching material is qualified in content, presentation, language, and graphic feasibility aspects. The characteristic of this teaching material expose the closeness theme with student daily lifes and its compatibility with National Books Standard. Based on the understanding test results, the teaching material is qualified in understanding aspect with high category. It can be concluded that the teaching material qualified to be used as supplement teaching material of science learning.Penelitian ini bertujuan untuk mengembangkan, menguji kelayakan, memaparkan karakteristik, dan menguji keterpahaman bahan ajar IPA terpadu pada tema udara untuk siswa SMP kelas VII melalui Four Steps Teaching Material Development (4S TMD. Penelitian dengan metode Research and Development (R&D ini dilatar belakangi oleh tidak tersedianya bahan ajar IPA SMP yang disajikan secara terpadu melalui tema udara. Pengembangan bahan ajar IPA terpadu tema udara terdiri dari tahap seleksi, strukturisasi, karakterisasi dan reduksi didaktik. Berdasarkan uji kelayakan, bahan ajar telah memenuhi aspek kelayakan isi, kelayakan penyajian, kelayakan bahasa dan kelayakan kegrafikan. Karakteristik bahan ajar meliputi kedekatan tema bahan ajar

Numerical Analysis of the Influence of Thermal Mass, Phase Change Materials and Furniture / Indoor Content on Building Energy Flexibility

DEFF Research Database (Denmark)

Johra, Hicham; Heiselberg, Per Kvols; Dreau, Jerome Le

2017-01-01

Many numerical models for building energy simulation assume empty rooms and do not account for the indoor content of occupied buildings. Furnishing elements and indoor items have complicated shapes and are made of various materials. Therefore, most of the people prefer to ignore them. However, th......, it is shown that the integration of phase change materials in wallboards or furniture elements can appreciably improve the energy flexibility of buildings....

Lightweight Phase-Change Material For Solar Power

Science.gov (United States)

Stark, Philip

1993-01-01

Lightweight panels containing phase-change materials developed for use as heat-storage elements of compact, lightweight, advanced solar dynamic power system. During high insolation, heat stored in panels via latent heat of fusion of phase-change material; during low insolation, heat withdrawn from panels. Storage elements consist mainly of porous carbon-fiber structures imbued with germanium. Developed for use aboard space station in orbit around Earth, also adapted to lightweight, compact, portable solar-power systems for use on Earth.

Dielectric Characteristics of Microstructural Changes and Property Evolution in Engineered Materials

Science.gov (United States)

Clifford, Jallisa Janet

Heterogeneous materials are increasingly used in a wide range of applications such as aerospace, civil infrastructure, fuel cells and many others. The ability to take properties from two or more materials to create a material with properties engineered to needs is always very attractive. Hence heterogeneous materials are evolving into more complex formulations in multiple disciplines. Design of microstructure at multiple scales control the global functional properties of these materials and their structures. However, local microstructural changes do not directly cause a proportional change to the global properties (such as strength and stiffness). Instead, local changes follow an evolution process including significant interactions. Therefore, in order to understand property evolution of engineered materials, microstructural changes need to be effectively captured. Characterizing these changes and representing them by material variables will enable us to further improve our material level understanding. In this work, we will demonstrate how microstructural features of heterogeneous materials can be described quantitatively using broadband dielectric spectroscopy (BbDS). The frequency dependent dielectric properties can capture the change in material microstructure and represent these changes in terms of material variables, such as complex permittivity. These changes in terms of material properties can then be linked to a number of different conditions, such as increasing damage due to impact or fatigue. Two different broadband dielectric spectroscopy scanning modes are presented: bulk measurements and continuous scanning to measure dielectric property change as a function of position across the specimen. In this study, we will focus on ceramic materials and fiber reinforced polymer matrix composites as test bed material systems. In the first part of the thesis, we will present how different micro-structural design of porous ceramic materials can be captured

Concepts on integration of physical protection and material accounting functions in a safeguards system

International Nuclear Information System (INIS)

Reynolds, D.A.

1981-01-01

Concepts on integration of physical protection and material accounting systems to enhance overall safeguards capability are developed and presented. These concepts identify ways in which material accounting systems can be used to enable effective monitoring of authorized movement of nuclear material through physical protection boundaries. Concepts are also discussed for monitoring user access to nuclear material and for tagging user identification to material accounting transactions through physical protection functions. These result in benefits in detecting diversion and in positively tracing material movement. Finally, coordination of safeguards information from both subsystems in such an integrated system through a safeguards coordination center is addressed with emphasis on appropriate response in case of discrepancies

The J-integral concept for elastic-plastic material behavior

International Nuclear Information System (INIS)

Schmitt, W.; Kienzler, R.

1987-03-01

A simple analytical extension of the J integral has been presented which extends the J concept to apply for materials described by an incremental theory of plasticity. The stress work density replacing the strain energy density is load-history dependent. The J integral may be made path independent by virtue of an additional volume integral and may be understood as work dissipation rate. The discussion of the consequences for the applicability of the J concept to describe fracture processes showed that validity criteria proposed in the standards are not sufficient to yield configuration-independent J-resistance curves. However, a possibility is sketched to assess those structure-dependent resistance curves based on plastic-collapse considerations. With 6 figs., 33 refs

Reconfigurable optical manipulation by phase change material waveguides.

Science.gov (United States)

Zhang, Tianhang; Mei, Shengtao; Wang, Qian; Liu, Hong; Lim, Chwee Teck; Teng, Jinghua

2017-05-25

Optical manipulation by dielectric waveguides enables the transportation of particles and biomolecules beyond diffraction limits. However, traditional dielectric waveguides could only transport objects in the forward direction which does not fulfill the requirements of the next generation lab-on-chip system where the integrated manipulation system should be much more flexible and multifunctional. In this work, bidirectional transportation of objects on the nanoscale is demonstrated on a rectangular waveguide made of the phase change material Ge 2 Sb 2 Te 5 (GST) by numerical simulations. Either continuous pushing forces or pulling forces are generated on the trapped particles when the GST is in the amorphous or crystalline phase. With the technique of a femtosecond laser induced phase transition on the GST, we further proposed a reconfigurable optical trap array on the same waveguide. This work demonstrates GST waveguide's potential of achieving multifunctional manipulation of multiple objects on the nanoscale with plausible optical setups.

Metasurfaces Based on Phase-Change Material as a Reconfigurable Platform for Multifunctional Devices

Science.gov (United States)

Raeis-Hosseini, Niloufar; Rho, Junsuk

2017-01-01

Integration of phase-change materials (PCMs) into electrical/optical circuits has initiated extensive innovation for applications of metamaterials (MMs) including rewritable optical data storage, metasurfaces, and optoelectronic devices. PCMs have been studied deeply due to their reversible phase transition, high endurance, switching speed, and data retention. Germanium-antimony-tellurium (GST) is a PCM that has amorphous and crystalline phases with distinct properties, is bistable and nonvolatile, and undergoes a reliable and reproducible phase transition in response to an optical or electrical stimulus; GST may therefore have applications in tunable photonic devices and optoelectronic circuits. In this progress article, we outline recent studies of GST and discuss its advantages and possible applications in reconfigurable metadevices. We also discuss outlooks for integration of GST in active nanophotonic metadevices. PMID:28878196

Multiscale paradigms in integrated computational materials science and engineering materials theory, modeling, and simulation for predictive design

CERN Document Server

Runge, Keith; Muralidharan, Krishna

2016-01-01

This book presents cutting-edge concepts, paradigms, and research highlights in the field of computational materials science and engineering, and provides a fresh, up-to-date perspective on solving present and future materials challenges. The chapters are written by not only pioneers in the fields of computational materials chemistry and materials science, but also experts in multi-scale modeling and simulation as applied to materials engineering. Pedagogical introductions to the different topics and continuity between the chapters are provided to ensure the appeal to a broad audience and to address the applicability of integrated computational materials science and engineering for solving real-world problems.

Polymers in phase change materials

Energy Technology Data Exchange (ETDEWEB)

Ferreira, M.C.; Brites, M.J.; Alexandre, J.H. [National Lab. for Energy and Geology, Lisbon (Portugal)

2010-07-01

Phase Change Materials (PCMs) which are the core of latent heat thermal energy storage systems are currently an area of investigation of increasing interest. Several substances differing in physical and chemical characteristics as well as in thermal behavior have been studied as PCMS{sup 1-3}. In order to meet the requisites of particular systems, auxiliary materials are often used with specific functions. This bibliographic survey shows that polymeric materials have been proposed either as the PCM itself in solid-liquid or solid-solid transitions or to perform auxiliary functions of shape stabilisation and microencapsulation for solid-liquid PCMs. The PCMs have an operating temperature ranging from around 0 C (for the system water/polyacrilamid) to around 127 C (for crosslinked HDPE). (orig.)

The socio-materiality of designing organizational change

DEFF Research Database (Denmark)

Stang Våland, Marianne; Georg, Susse

2014-01-01

Purpose – The purpose of this paper is to examine the managerial implications of adopting a design attitude to organizational change. Design/methodology/approach – Based on an ethnographic study of a merger, the paper investigates the intricate interplay between architectural design...... and organizational change in the context of physically relocating an organization to a new office building. Emphasis is given to the socio-materiality of this double design process. Findings – The data suggests that taking a design attitude toward managing organizational change can allow different actors...... to participate in organizational design processes, releasing management from its traditional role as the keeper of the design solution. Research limitations/implications – Although based on a single case, the paper provides insights into the socio-materiality of organizational change that is relevant in other...

INTEGRATED DEVELOPMENT OF CHEMICAL TEACHING MATERIALS ON MATERIAL BASED THERMOCHEMICAL SOFT SKILLS FOR VOCATIONAL STUDENTS

Directory of Open Access Journals (Sweden)

S. D. Purnawan

2015-11-01

Full Text Available Business and industrial field need workers who have not only good academic achievement but also the ability of hard skills and soft skills.  In order to prepare students who have a good academic skills, hard skills, soft skills it has to be done in all subjects including chemistry expertise to integrate the competencies of Motorcycle Engineering.  The research design uses One Group Pretest Posttest Design imposed on students in class XI SMK 1 Kedung TSM. Validator assessment results indicate that teaching materials developed very feasible for use in learning chemistry.  The result show that the learning device by using the integrated chemistry materials can increase students understanding of the thermo chemistry material with the acquisition of N-gain is at 0.63 or in the medium category.  Group of high-achieving students have the score of N-gain of 0.65, while the medium-achieving students get 0.63 and low-achieving students get 0.61, all have medium category.  Percentage  of students who passes the mastery learning  if mastery learning (KKM > 75 or reach 87 %.  The percentage of students’ soft skills in at least good criteria is at 87.10 %.  Students gave positive responses  90.71 % towards the learning material that is developed.

What does materiality mean to integrated reporting preparers? An empirical exploration

OpenAIRE

Lai, Alessandro; Melloni, Gaia; Stacchezzini, Riccardo

2017-01-01

Purpose—This paper seeks to understand how the principle of materiality gets implemented in integrated reporting contexts. Design/methodology/approach—Drawing on an interpretation of materiality as a social construction, this research explores the meaning that practitioners attach to the principle during their implementation of it. Following an existing framework for exploring materiality in corporate reporting, this study investigates the meaning by focusing on who participates in determinin...

EDDA: integrated simulation of debris flow erosion, deposition and property changes

Science.gov (United States)

Chen, H. X.; Zhang, L. M.

2014-11-01

Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA, is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during the flow process. The yield stress of debris flow mixture is determined at limit equilibrium using the Mohr-Coulomb equation, which is applicable to clear water flow, hyper-concentrated flow and fully developed debris flow. To assure numerical stability and computational efficiency at the same time, a variable time stepping algorithm is developed to solve the governing differential equations. Four numerical tests are conducted to validate the model. The first two tests involve a one-dimensional dam-break water flow and a one-dimensional debris flow with constant properties. The last two tests involve erosion and deposition, and the movement of multi-directional debris flows. The changes in debris flow mass and properties due to either erosion or deposition are shown to affect the runout characteristics significantly. The model is also applied to simulate a large-scale debris flow in Xiaojiagou Ravine to test the performance of the model in catchment-scale simulations. The results suggest that the model estimates well the volume, inundated area, and runout distance of the debris flow. The model is intended for use as a module in a real-time debris flow warning system.

Episode-Centered Guidelines for Teacher Belief Change toward Technology Integration

Science.gov (United States)

Er, Erkan; Kim, ChanMin

2017-01-01

Teachers' episodic memories influence their beliefs. The investigation of episodic memories can help identify the teacher beliefs that limit technology-integration. We propose the Episode-Centered Belief Change (ECBC) model that utilizes teachers' episodic memories for changing beliefs impeding effective technology integration. We also propose…

Phase change materials and the perception of wetness.

Science.gov (United States)

Tiest, Wouter M Bergmann; Kosters, N Dolfine; Kappers, Astrid M L; Daanen, Hein A M

2012-01-01

Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead of cold. In order to investigate if this phenomenon occurs when manipulating textiles, nine subjects were asked to touch or manipulate PCM-treated and untreated fabrics. In 75% of the cases, the subjects indicated that the treated material felt wetter than the untreated material independent of the way the textiles were manipulated. We conclude that incorporating PCMs in textiles may lead to a feeling of wetness which might be uncomfortable. Therefore, we recommend investigating a change in cooling properties to minimise this feeling. This article describes a psychophysical experiment into the sensation of wetness of textiles treated with phase change materials. It was found that in 75% of the cases, subjects found the treated fabric to feel wetter than the untreated. This may affect the comfort of wearing clothes made of these textiles.

Thermal Peak Management Using Organic Phase Change Materials for Latent Heat Storage in Electronic Applications

Science.gov (United States)

Maxa, Jacob; Novikov, Andrej; Nowottnick, Mathias

2017-01-01

Modern high power electronics devices consists of a large amount of integrated circuits for switching and supply applications. Beside the benefits, the technology exhibits the problem of an ever increasing power density. Nowadays, heat sinks that are directly mounted on a device, are used to reduce the on-chip temperature and dissipate the thermal energy to the environment. This paper presents a concept of a composite coating for electronic components on printed circuit boards or electronic assemblies that is able to buffer a certain amount of thermal energy, dissipated from a device. The idea is to suppress temperature peaks in electronic components during load peaks or electronic shorts, which otherwise could damage or destroy the device, by using a phase change material to buffer the thermal energy. The phase change material coating could be directly applied on the chip package or the PCB using different mechanical retaining jigs.

Thermal Peak Management Using Organic Phase Change Materials for Latent Heat Storage in Electronic Applications

Directory of Open Access Journals (Sweden)

Jacob Maxa

2017-12-01

Full Text Available Modern high power electronics devices consists of a large amount of integrated circuits for switching and supply applications. Beside the benefits, the technology exhibits the problem of an ever increasing power density. Nowadays, heat sinks that are directly mounted on a device, are used to reduce the on-chip temperature and dissipate the thermal energy to the environment. This paper presents a concept of a composite coating for electronic components on printed circuit boards or electronic assemblies that is able to buffer a certain amount of thermal energy, dissipated from a device. The idea is to suppress temperature peaks in electronic components during load peaks or electronic shorts, which otherwise could damage or destroy the device, by using a phase change material to buffer the thermal energy. The phase change material coating could be directly applied on the chip package or the PCB using different mechanical retaining jigs.

Integrating CAD/CAM in Automation and Materials Handling

Science.gov (United States)

Deal, Walter F.; Jones, Catherine E.

2012-01-01

Humans by their very nature are users of tools, materials, and processes as a part of their survival and existence. As humans have progressed over time, their civilizations and societies have changed beyond imagination and have moved from hunters and gatherers of food and materials for survival to sophisticated societies with complex social and…

Integrated models for plasma/material interaction during loss of plasma confinement

International Nuclear Information System (INIS)

Hassanein, A.

1998-01-01

A comprehensive computer package, High Energy Interaction with General Heterogeneous Target Systems (HEIGHTS), has been developed to evaluate the damage incurred on plasma-facing materials during loss of plasma confinement. The HEIGHTS package consists of several integrated computer models that follow the start of a plasma disruption at the scrape-off layer (SOL) through the transport of the eroded debris and splashed target materials to nearby locations as a result of the energy deposited. The package includes new models to study turbulent plasma behavior in the SOL and predicts the plasma parameters and conditions at the divertor plate. Full two-dimensional comprehensive radiation magnetohydrodynamic models are coupled with target thermodynamics and liquid hydrodynamics to evaluate the integrated response of plasma-facing materials. A brief description of the HEIGHTS package and its capabilities are given in this work with emphasis on turbulent plasma behavior in the SOL during disruptions

Development of integrated platform for computational material design

Energy Technology Data Exchange (ETDEWEB)

Kiyoshi, Matsubara; Kumi, Itai; Nobutaka, Nishikawa; Akifumi, Kato [Center for Computational Science and Engineering, Fuji Research Institute Corporation (Japan); Hideaki, Koike [Advance Soft Corporation (Japan)

2003-07-01

The goal of our project is to design and develop a problem-solving environment (PSE) that will help computational scientists and engineers develop large complicated application software and simulate complex phenomena by using networking and parallel computing. The integrated platform, which is designed for PSE in the Japanese national project of Frontier Simulation Software for Industrial Science, is defined by supporting the entire range of problem solving activity from program formulation and data setup to numerical simulation, data management, and visualization. A special feature of our integrated platform is based on a new architecture called TASK FLOW. It integrates the computational resources such as hardware and software on the network and supports complex and large-scale simulation. This concept is applied to computational material design and the project 'comprehensive research for modeling, analysis, control, and design of large-scale complex system considering properties of human being'. Moreover this system will provide the best solution for developing large and complicated software and simulating complex and large-scaled phenomena in computational science and engineering. A prototype has already been developed and the validation and verification of an integrated platform will be scheduled by using the prototype in 2003. In the validation and verification, fluid-structure coupling analysis system for designing an industrial machine will be developed on the integrated platform. As other examples of validation and verification, integrated platform for quantum chemistry and bio-mechanical system are planned.

Development of integrated platform for computational material design

International Nuclear Information System (INIS)

Kiyoshi, Matsubara; Kumi, Itai; Nobutaka, Nishikawa; Akifumi, Kato; Hideaki, Koike

2003-01-01

The goal of our project is to design and develop a problem-solving environment (PSE) that will help computational scientists and engineers develop large complicated application software and simulate complex phenomena by using networking and parallel computing. The integrated platform, which is designed for PSE in the Japanese national project of Frontier Simulation Software for Industrial Science, is defined by supporting the entire range of problem solving activity from program formulation and data setup to numerical simulation, data management, and visualization. A special feature of our integrated platform is based on a new architecture called TASK FLOW. It integrates the computational resources such as hardware and software on the network and supports complex and large-scale simulation. This concept is applied to computational material design and the project 'comprehensive research for modeling, analysis, control, and design of large-scale complex system considering properties of human being'. Moreover this system will provide the best solution for developing large and complicated software and simulating complex and large-scaled phenomena in computational science and engineering. A prototype has already been developed and the validation and verification of an integrated platform will be scheduled by using the prototype in 2003. In the validation and verification, fluid-structure coupling analysis system for designing an industrial machine will be developed on the integrated platform. As other examples of validation and verification, integrated platform for quantum chemistry and bio-mechanical system are planned

Integration of the market of the European community and the change of the industrial structure. EC shijo togo to sangyo kozo no henka

Energy Technology Data Exchange (ETDEWEB)

Tanimoto, T; Uno, K; Nakamura, T; Yamashita, S [Osaka Sangyo University, Osaka (Japan). Institute for Industrial Research

1992-11-20

This paper considers problems in the change of the industrial structure as a result of the EC market integration, and the change of the physical distribution structure, mainly in cargo transportation. The market integration is being moved forward mainly on liberalization of flows in people, materials, and currencies, but the material flow liberalization has not progressed noticeably because of difficulty in deregulations. Changes in the transportation structure on the whole in the EC countries would not see a complete removal of barriers supported by the transportation licensing system because of issues in protecting domestic transportation markets and sharing the road expenses, even if the tariff barrier has been removed as a result of the market integration. Amid the predictions on deregulated legislations and intensified competition associated with the integration, the French trucking industry is indicated of its direction toward a two-layer structure comprising large-scale enterprises and medium-to-small companies. The German unification created problems in transferring from the socialistic command economy to the capitalistic market economy. The paper gives considerations on the real state of affairs in the privatization policy of the people-owned enterprises in the former East Germany, and its economic and managerial problems that should be solved amid the large-area EC market integration based on the mutualism over and above the economic system transition.

Welded joints integrity analysis and optimization for fiber laser welding of dissimilar materials

Science.gov (United States)

Ai, Yuewei; Shao, Xinyu; Jiang, Ping; Li, Peigen; Liu, Yang; Liu, Wei

2016-11-01

Dissimilar materials welded joints provide many advantages in power, automotive, chemical, and spacecraft industries. The weld bead integrity which is determined by process parameters plays a significant role in the welding quality during the fiber laser welding (FLW) of dissimilar materials. In this paper, an optimization method by taking the integrity of the weld bead and weld area into consideration is proposed for FLW of dissimilar materials, the low carbon steel and stainless steel. The relationships between the weld bead integrity and process parameters are developed by the genetic algorithm optimized back propagation neural network (GA-BPNN). The particle swarm optimization (PSO) algorithm is taken for optimizing the predicted outputs from GA-BPNN for the objective. Through the optimization process, the desired weld bead with good integrity and minimum weld area are obtained and the corresponding microstructure and microhardness are excellent. The mechanical properties of the optimized joints are greatly improved compared with that of the un-optimized welded joints. Moreover, the effects of significant factors are analyzed based on the statistical approach and the laser power (LP) is identified as the most significant factor on the weld bead integrity and weld area. The results indicate that the proposed method is effective for improving the reliability and stability of welded joints in the practical production.

A case study: Integrated work environment and organizational change

Energy Technology Data Exchange (ETDEWEB)

Heubach, J.G.; Montgomery, J.C.; Weimer, W.C. [Pacific Northwest Lab., Richland, WA (United States); Heerwagen, J.H. [Battelle Seattle Research Center, WA (United States)

1995-02-01

The failure to integrate environmental and organizational interventions may help explain the lack of success of many change efforts. The high rate of failure for change efforts (50% to 90% failure rates) has been noted by many writers. While specific causes of failure are diverse, a common theme has been failure to consider the organization as a system. That is, either significant aspects of the organization were ignored during the intervention or potential impacts of changes on the elements were overlooked or underestimated. Our own training, technical literature, and professional culture lead us to limited understandings of complex organizations. Change agents must consider all relevant components of organizational performance if interventions are to be meaningful and successful. This study demonstrated the value of an integrated organizational intervention involving redesign of the physical environment, introduction of a new information system, work process improvement, and extended organizational development intervention. The outcomes were extremely positive. The cost of improvement efforts was found to be recaptured within a short time, easily justifying the expenditures. One conclusion from the study is that integrated interventions are very powerful. Integrating improvement of the physical environment with organizational development and technological innovation greatly enhances the likelihood of achieving a successful intervention.

Integrated optoelectronic materials and circuits for optical interconnects

International Nuclear Information System (INIS)

Hutcheson, L.D.

1988-01-01

Conventional interconnect and switching technology is rapidly becoming a critical issue in the realization of systems using high speed silicon and GaAs based technologies. In recent years clock speeds and on-chip density for VLSI/VHSIC technology has made packaging these high speed chips extremely difficult. A strong case can be made for using optical interconnects for on-chip/on-wafer, chip-to-chip and board-to-board high speed communications. GaAs integrated optoelectronic circuits (IOC's) are being developed in a number of laboratories for performing Input/Output functions at all levels. In this paper integrated optoelectronic materials, electronics and optoelectronic devices are presented. IOC's are examined from the standpoint of what it takes to fabricate the devices and what performance can be expected

Contamination aspects in integrating high dielectric constant and ferroelectric materials into CMOS processes

OpenAIRE

Boubekeur, Hocine

2004-01-01

n memory technology, new materials are being intensively investigated to overcome the integration limits of conventional dielectrics for Giga-bit scale integration, or to be able to produce new types of non-volatile low power memories such as FeRAM. Perovskite type high dielectric constant films for use in Giga-bit scale memories or layered perovskite films for use in non-volatile memories involve materials to semiconductor process flows, which entail a high risk of contamination. The introdu...

Integrating technology in a changing organisation

International Nuclear Information System (INIS)

Guillon, O.

1996-01-01

The paper relates to integrating technology in a changing organisation of Elf Aquitaine. There is a strong pressure to cut costs and be more effective in the company's operations. A process was initiated in 1994 to re-analyse its E and P (Exploration and Production) research and development (R and D) in order to enhance its alignment with the company assets needs, with a subsequent prioritization of R and D projects. The integration included a strategy for cooperation with other oil and service companies. The author presents the process set up to align the company's R and D program to the business needs of its operations, the various levels of cooperation used, and finally an illustration, in the domain of the geosciences, of the various facets of the ongoing cultural revolution which is required to reach a true integration. 11 figs

An Integrated Computational Materials Engineering Method for Woven Carbon Fiber Composites Preforming Process

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weizhao; Ren, Huaqing; Wang, Zequn; Liu, Wing K.; Chen, Wei; Zeng, Danielle; Su, Xuming; Cao, Jian

2016-10-19

An integrated computational materials engineering method is proposed in this paper for analyzing the design and preforming process of woven carbon fiber composites. The goal is to reduce the cost and time needed for the mass production of structural composites. It integrates the simulation methods from the micro-scale to the macro-scale to capture the behavior of the composite material in the preforming process. In this way, the time consuming and high cost physical experiments and prototypes in the development of the manufacturing process can be circumvented. This method contains three parts: the micro-scale representative volume element (RVE) simulation to characterize the material; the metamodeling algorithm to generate the constitutive equations; and the macro-scale preforming simulation to predict the behavior of the composite material during forming. The results show the potential of this approach as a guidance to the design of composite materials and its manufacturing process.

Ultrafast characterization of phase-change material crystallization properties in the melt-quenched amorphous phase.

Science.gov (United States)

Jeyasingh, Rakesh; Fong, Scott W; Lee, Jaeho; Li, Zijian; Chang, Kuo-Wei; Mantegazza, Davide; Asheghi, Mehdi; Goodson, Kenneth E; Wong, H-S Philip

2014-06-11

Phase change materials are widely considered for application in nonvolatile memories because of their ability to achieve phase transformation in the nanosecond time scale. However, the knowledge of fast crystallization dynamics in these materials is limited because of the lack of fast and accurate temperature control methods. In this work, we have developed an experimental methodology that enables ultrafast characterization of phase-change dynamics on a more technologically relevant melt-quenched amorphous phase using practical device structures. We have extracted the crystallization growth velocity (U) in a functional capped phase change memory (PCM) device over 8 orders of magnitude (10(-10) 10(8) K/s), which reveals the extreme fragility of Ge2Sb2Te5 in its supercooled liquid phase. Furthermore, these crystallization properties were studied as a function of device programming cycles, and the results show degradation in the cell retention properties due to elemental segregation. The above experiments are enabled by the use of an on-chip fast heater and thermometer called as microthermal stage (MTS) integrated with a vertical phase change memory (PCM) cell. The temperature at the PCM layer can be controlled up to 600 K using MTS and with a thermal time constant of 800 ns, leading to heating rates ∼10(8) K/s that are close to the typical device operating conditions during PCM programming. The MTS allows us to independently control the electrical and thermal aspects of phase transformation (inseparable in a conventional PCM cell) and extract the temperature dependence of key material properties in real PCM devices.

The Influence of a Radiant Panel System with Integrated Phase Change Material on Energy Use and Thermal Indoor Environment

DEFF Research Database (Denmark)

Nielsen, Lin Flemming; Bourdakis, Eleftherios; Kazanci, Ongun Berk

2018-01-01

This study examined the effect on energy use and thermal comfort when combining microencapsulated phase change material (PCM) with radiant ceiling panels in a two-person office. The performance of the system was studied during the cooling season in the climates of Copenhagen, Denmark, and Rome...

Electron-beam-irradiation-induced crystallization of amorphous solid phase change materials

Science.gov (United States)

Zhou, Dong; Wu, Liangcai; Wen, Lin; Ma, Liya; Zhang, Xingyao; Li, Yudong; Guo, Qi; Song, Zhitang

2018-04-01

The electron-beam-irradiation-induced crystallization of phase change materials in a nano sized area was studied by in situ transmission electron microscopy and selected area electron diffraction. Amorphous phase change materials changed to a polycrystalline state after being irradiated with a 200 kV electron beam for a long time. The results indicate that the crystallization temperature strongly depends on the difference in the heteronuclear bond enthalpy of the phase change materials. The selected area electron diffraction patterns reveal that Ge2Sb2Te5 is a nucleation-dominated material, when Si2Sb2Te3 and Ti0.5Sb2Te3 are growth-dominated materials.

The application of J integral to measure cohesive laws in materials undergoing large scale yielding

DEFF Research Database (Denmark)

Sørensen, Bent F.; Goutianos, Stergios

2015-01-01

We explore the possibility of determining cohesive laws by the J-integral approach for materials having non-linear stress-strain behaviour (e.g. polymers and composites) by the use of a DCB sandwich specimen, consisting of stiff elastic beams bonded to the non-linear test material, loaded with pure...... bending moments. For a wide range of parameters of the non-linear material, the plastic unloading during crack extension is small, resulting in J integral values (fracture resistance) that deviate maximum 15% from the work of the cohesive traction. Thus the method can be used to extract the cohesive laws...... directly from experiments without any presumption about their shape. Finally, the DCB sandwich specimen was also analysed using the I integral to quantify the overestimation of the steady-state fracture resistance obtained using the J integral based method....

Encapsulation of phase change materials using rice-husk-char

International Nuclear Information System (INIS)

Gondora, Wayne; Doudin, Khalid; Nowakowski, Daniel J.; Xiao, Bo; Ding, Yulong; Bridgwater, Tony; Yuan, Qingchun

2016-01-01

Highlights: • Rice-husk-char particles are successfully used in the encapsulation of phase change materials. • Carbon-based phase change microcapsules aim at using the high thermal conductivity of carbon materials. • Carbon from biomass can be used in low and intermediate heat harvest and storage. • Carbon in biomass is captured and to be used in improving energy efficiency. - Abstract: This paper explored a new approach to prepare phase change microcapsules using carbon-based particles via Pickering emulsions for energy storage applications. Rice-husk-char, a by-product in biofuel production, containing 53.58 wt% of carbon was used as a model carbon-based material to encapsulate hexadecane. As a model phase change material, hexadecane was emulsified in aqueous suspensions of rice-husk-char nanoparticles. Water soluble polymers poly(diallyldimethyl-ammonium chloride) and poly(sodium styrene sulfonate) were used to fix the rice-husk-char nanoparticles on the emulsion droplets through layer-by-layer assembly to enhance the structural stability of the microcapsules. The microcapsules formed are composed of a thin shell encompassing a large core consisting of hexadecane. Thermal gravimetrical and differential scanning calorimeter analyses showed the phase change enthalpy of 80.9 kJ kg"−"1 or 120.0 MJ m"−"3. Design criteria of phase change microcapsules and preparation considerations were discussed in terms of desired applications. This work demonstrated possible utilisations of biomass-originated carbon-based material for thermal energy recovery and storage applications, which can be a new route of carbon capture and utilisation.

A zero density change phase change memory material: GeTe-O structural characteristics upon crystallisation.

Science.gov (United States)

Zhou, Xilin; Dong, Weiling; Zhang, Hao; Simpson, Robert E

2015-06-11

Oxygen-doped germanium telluride phase change materials are proposed for high temperature applications. Up to 8 at.% oxygen is readily incorporated into GeTe, causing an increased crystallisation temperature and activation energy. The rhombohedral structure of the GeTe crystal is preserved in the oxygen doped films. For higher oxygen concentrations the material is found to phase separate into GeO2 and TeO2, which inhibits the technologically useful abrupt change in properties. Increasing the oxygen content in GeTe-O reduces the difference in film thickness and mass density between the amorphous and crystalline states. For oxygen concentrations between 5 and 6 at.%, the amorphous material and the crystalline material have the same density. Above 6 at.% O doping, crystallisation exhibits an anomalous density change, where the volume of the crystalline state is larger than that of the amorphous. The high thermal stability and zero-density change characteristic of Oxygen-incorporated GeTe, is recommended for efficient and low stress phase change memory devices that may operate at elevated temperatures.

An integrated approach to selecting materials for fuel cladding in advanced high-temperature reactors

Energy Technology Data Exchange (ETDEWEB)

Rangacharyulu, C., E-mail: chary.r@usask.ca [Univ. of Saskatchewan, Saskatoon, SK (Canada); Guzonas, D.A.; Pencer, J.; Nava-Dominguez, A.; Leung, L.K.H. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

2014-07-01

An integrated approach has been developed for selection of fuel cladding materials for advanced high-temperature reactors. Reactor physics, thermalhydraulic and material analyses are being integrated in a systematic study comparing various candidate fuel-cladding alloys. The analyses established the axial and radial neutron fluxes, power distributions, axial and radial temperature distributions, rates of defect formation and helium production using AECL analytical toolsets and experimentally measured corrosion rates to optimize the material composition for fuel cladding. The project has just been initiated at University of Saskatchewan. Some preliminary results of the analyses are presented together with the path forward for the project. (author)

Synergistic Integration of Experimental and Simulation Approaches for the de Novo Design of Silk-Based Materials.

Science.gov (United States)

Huang, Wenwen; Ebrahimi, Davoud; Dinjaski, Nina; Tarakanova, Anna; Buehler, Markus J; Wong, Joyce Y; Kaplan, David L

2017-04-18

modeling with experiment. In this Account, we summarize recent advances in understanding and functionalization of silk-based protein systems, with a focus on the integration of simulation and experiment for biopolymer design. Spider silk was selected as an exemplary protein to address the fundamental challenges in polymer designs, including specific insights into the role of molecular weight, hydrophobic/hydrophilic partitioning, and shear stress for silk fiber formation. To expand current silk designs toward biointerfaces and stimuli responsive materials, peptide modules from other natural proteins were added to silk designs to introduce new functions, exploiting the modular nature of silk proteins and fibrous proteins in general. The integrated approaches explored suggest that protein folding, silk volume fraction, and protein amino acid sequence changes (e.g., mutations) are critical factors for functional biomaterial designs. In summary, the integrated modeling-experimental approach described in this Account suggests a more rationally directed and more rapid method for the design of polymeric materials. It is expected that this combined use of experimental and computational approaches has a broad applicability not only for silk-based systems, but also for other polymer and composite materials.

Integration and change management for successful mergers; Integration und Change Management bei Fusionen

Energy Technology Data Exchange (ETDEWEB)

Wolf, H.G. [Arthur Andersen Business Consulting GmbH, Duesseldorf (Germany)

2000-05-01

In the wake of deregulation of the energy markets in Germany, energy companies and electric utilities are confronted with fierce competition on prices and customers. The change of paradigms in the German energy industry calls for new strategies. The article discusses strategic alliances and mergers as one way to cope with the challenges, and explains suitable and proven approaches for corporate integration and change management. (CB) [German] Seit der wettbewerblichen Oeffnung des deutschen Energiemarktes sehen sich die Unternehmen mit einem dramatischen Preis- und Marketingwettbewerb konfrontiert. Aggressive neue Akteure draengen in die lukrativen Maerkte. Aber auch etablierte Teilnehmer suchen neue strategische Positionen und beschleunigen den Paradigmenwechsel in der deutschen Energiewirtschaft. Angesichts dieser Marktentwicklung bestehen massive Anforderungen zur Veraenderung. Unternehmenszusammenschluesse und Kooperationen stellen eine geeignete strategische Reaktion zur Bewaeltigung dieser Herausforderungen dar. Dabei sollten die Risiken von Fusionen nicht unterschaetzt werden. Die meisten Vorhaben scheitern auf Grund fehlender Integrationsprozesse. Ein systematischer Integrationsansatz wird beschrieben. (orig./CB)

Flexible composite material with phase change thermal storage

Science.gov (United States)

Buckley, Theresa M. (Inventor)

2001-01-01

A highly flexible composite material having a flexible matrix containing a phase change thermal storage material. The composite material can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The composite may also include an external thermal insulation layer and/or an internal thermal control layer to regulate the rate of heat exchange between the composite and the skin of the wearer. Other embodiments of the PCM composite also provide 1) a path for evaporation or direct absorption of perspiration from the skin of the wearer for improved comfort and thermal control, 2) heat conductive pathways within the material for thermal equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal socks, ,gloves and a face mask for cold weather activities, and a metabolic heating or cooling blanket useful for treating hypothermia or fever patients in a medical setting and therapeutic heating or cooling orthopedic joint supports.

Successfully Integrating Climate Change Education into School System Curriculum

Science.gov (United States)

Scallion, M.

2017-12-01

Maryland's Eastern Shore is threatened by climate change driven sea level rise. By working with school systems, rather than just with individual teachers, educators can gain access to an entire grade level of students, assuring that all students, regardless of socioeconomic background or prior coursework have an opportunity to explore the climate issue and be part of crafting community level solutions for their communities. We will address the benefits of working with school system partners to achieve a successful integration of in-school and outdoor learning by making teachers and administrators part of the process. We will explore how, through the Maryland and Delaware Climate Change Education, Assessment, and Research Project, teachers, content supervisors and informal educators worked together to create a climate curriculum with local context that effectively meets Common Core and Next Generation Science Standards. Over the course of several weeks during the year, students engage in a series of in-class and field activities directly correlated with their science curriculum. Wetlands and birds are used as examples of the local wildlife and habitat being impacted by climate change. Through these lessons led by Pickering Creek Audubon Center educators and strengthened by material covered by classroom teachers, students get a thorough introduction to the mechanism of climate change, local impacts of climate change on habitats and wildlife, and actions they can take as a community to mitigate the effects of climate change. The project concludes with a habitat and carbon stewardship project that gives students and teachers a sense of hope as they tackle this big issue on a local scale. We'll explore how the MADE-CLEAR Informal Climate Change Education (ICCE) Community of Practice supports Delaware and Maryland environmental educators in collaboratively learning and expanding their programming on the complex issue of climate change. Participants will learn how to

Lightweight structure design for wind energy by integrating nanostructured materials

International Nuclear Information System (INIS)

Li, Ying; Lu, Jian

2014-01-01

Highlights: • Integrate high-strength nano-materials into lightweight design. • Lightweight design scheme for wind turbine tower application. • Expand the bending formulae for tapered tubular structures with varying thickness. • We rewrite the Secant Formula for a tapered beam under eccentric compression. - Abstract: Wind power develops very fast nowadays with high expectation. Although at the mean time, the use of taller towers, however, smacks head-on into the issue of transportability. The engineering base and computational tools have to be developed to match machine size and volume. Consequently the research on the light weight structures of tower is carrying out in the main countries which are actively developing wind energy. This paper reports a new design scheme of light weight structure for wind turbine tower. This design scheme is based on the integration of the nanostructured materials produced by the Surface Mechanical Attrition Treatment (SMAT) process. The objective of this study is to accomplish the weight reduction by optimizing the wall thickness of the tapered tubular structure. The basic methods include the identification of the critical zones and the distribution of the high strength materials according to different necessities. The equivalent strength or stiffness design method and the high strength material properties after SMAT process are combined together. Bending and buckling are two main kinds of static loads concerned in consideration. The study results reveal that there is still enough margin for weight reduction in the traditional wind turbine tower design

Experimental Investigation of Thermal Conductivity of Concrete Containing Micro-Encapsulated Phase Change Materials

DEFF Research Database (Denmark)

Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

2011-01-01

in this article utilizes integration of the concrete and the microencapsulated Phase Change Material (PCM). PCM has the ability to absorb and release significant amounts of heat at a specific temperature range. As a consequence of admixing PCM to the concrete, new thermal properties like thermal conductivity...... and specific heat capacity have to be defined. This paper presents results from the measurements of the thermal conductivity of various microencapsulated PCM-concrete and PCM-cement-paste mixes. It was discovered that increase of the amount of PCM decreases the thermal conductivity of the concrete PCM mixture....... Finally, a theoretical calculation methodology of thermal conductivity for PCM-concrete mixes is developed....

Performance enhancement of hermetic compressor using phase change materials

Science.gov (United States)

Mahmoud, I. M.; Rady, M. A.; Huzayyin, A. S.

2015-08-01

The present study is motivated by the need for the research of simple measures for increasing energy efficiency of hermetic compressor. The measure is the application of phase change materials for performance enhancement. The first experimental study should be guide for choice of PCM. It has been performed to investigate the effects of thermostat setting temperature on the performance of hermetic compressor. The effects of thermostat setting temperature with and without load on power consumption have been analyzed. Performance enhancement using phase change materials (PCMs) has been studied by employing a phase change material Rubitherm-42 (RT-42) on the top surface of compressor. Choice of PCM material is based on basic compressor performance measured in the first part of the present study. Experiments have been carried out for different load values and different quantities of PCM. The quantity and phase change characteristic of PCM are essential parameters that determine the percentage of performance enhancement in term of energy consumption. Reduction of energy consumption of about 10% has been achieved in the present study by using PCM. The present study shows that how to reduce the electrical power consumption to enhance compressor heat dissipation method to improve efficiency.

Evaluation of material integrity on electricity power steam generator cycles (turbine casing) component

International Nuclear Information System (INIS)

Histori; Benedicta; Farokhi; S A, Soedardjo; Triyadi, Ari; Natsir, M

1999-01-01

The evaluation of material integrity on power steam generator cycles component was done. The test was carried out on casing turbine which is made from Inconel 617. The tested material was taken from t anjung Priok plant . The evaluation was done by metallography analysis using microscope with magnification of 400. From the result, it is shown that the material grains are equiaxed

High-authority smart material integrated electric actuator

Science.gov (United States)

Weisensel, G. N.; Pierce, Thomas D.; Zunkel, Gary

1997-05-01

For many current applications, hydraulic power is still the preferred method of gaining mechanical advantage. However, in many of these applications, this power comes with the penalties of high weight, size, cost, and maintenance due to the system's distributed nature and redundancy requirements. A high authority smart material Integrated Electric Actuator (IEA) is a modular, self-contained linear motion device that is capable of producing dynamic output strokes similar to those of hydraulic actuators yet at significantly reduced weight and volume. It provides system simplification and miniaturization. This actuator concept has many innovative features, including a TERFENOL-D-based pump, TERFENOL-D- based active valves, control algorithms, a displacement amplification unit and integrated, unitized packaging. The IEA needs only electrical power and a control command signal as inputs to provide high authority, high response rate actuation. This approach is directly compatible with distributed control strategies. Aircraft control, automotive brakes and fuel injection, and fluid power delivery are just some examples of the IEA's pervasive applications in aerospace, defense and commercial systems.

Solar-absorbing metamaterial microencapsulation of phase change materials for thermo-regulating textiles

Directory of Open Access Journals (Sweden)

William Tong

2015-04-01

Full Text Available This paper presents a novel concept for designing solar-absorbing metamaterial microcapsules of phase change materials (PCMs integrated with thermo-regulating smart textiles intended for coats or garments, especially for wear in space or cold weather on earth. The metamaterial is a periodically nanostructured metal-dielectric-metal thin film and can acquire surface plasmons to trap or absorb solar energy at subwavelength scales. This kind of metamaterial microencapsulation is not only able to take advantage of latent heat that can be stored or released from the PCMs over a tunable temperature range, but also has other advantages over conventional polymer microencapsulation of PCMs, such as enhanced thermal conductivity, improved flame-retardant capabilities, and usage as an extra solar power resource. The thermal analysis for this kind of microencapsulation has been done and can be used as a guideline for designing integrated thermo-regulating smart textiles in the future. These metamaterial microcapsules may open up new routes to enhancing thermo-regulating textiles with novel properties and added value.

Practice and progress in integrated assessments of climate change

International Nuclear Information System (INIS)

Toth, F.L.

1995-01-01

This paper is intended to provide an overview of the state of the art integrated socioeconomic-biophysical assessments of climate change as presented at the IIASA workshop in October 1993. The paper seeks to tally the major improvements facilitated by integrated assessments in understanding the global warming problem and the crucial unresolved problems they currently face. The basic conclusion is that, as a result of a healthy diversity in practice, integrated assessments show significant progress in structuring the economic issues of climate change and providing the first broad insights into policy options. But, as some of the simple and traditional cases seem to be solved, more complex and difficult contingencies come to the fore. This suggests a long way to go to develop skills that will be required to address the numerous open issues. (author)

Integrated assessment models of global climate change

International Nuclear Information System (INIS)

Parson, E.A.; Fisher-Vanden, K.

1997-01-01

The authors review recent work in the integrated assessment modeling of global climate change. This field has grown rapidly since 1990. Integrated assessment models seek to combine knowledge from multiple disciplines in formal integrated representations; inform policy-making, structure knowledge, and prioritize key uncertainties; and advance knowledge of broad system linkages and feedbacks, particularly between socio-economic and bio-physical processes. They may combine simplified representations of the socio-economic determinants of greenhouse gas emissions, the atmosphere and oceans, impacts on human activities and ecosystems, and potential policies and responses. The authors summarize current projects, grouping them according to whether they emphasize the dynamics of emissions control and optimal policy-making, uncertainty, or spatial detail. They review the few significant insights that have been claimed from work to date and identify important challenges for integrated assessment modeling in its relationships to disciplinary knowledge and to broader assessment seeking to inform policy- and decision-making. 192 refs., 2 figs

A Theory of Change for Student-Led Academic Integrity

Science.gov (United States)

Richards, Deborah; Saddiqui, Sonia; White, Fiona; McGuigan, Nicholas; Homewood, Judi

2016-01-01

Breaches in academic integrity are a pervasive and enduring international concern to the overall quality of higher education. Despite students being the group most affected by academic integrity policies, organisational culture is such that students tend to be passive recipients of change initiatives, rather than the drivers. To deliver a paradigm…

Phase Change Material Thermal Power Generator

Science.gov (United States)

Jones, Jack A. (Inventor); Chao, Yi (Inventor); Valdez, Thomas I. (Inventor)

2014-01-01

An energy producing device, for example a submersible vehicle for descending or ascending to different depths within water or ocean, is disclosed. The vehicle comprises a temperature-responsive material to which a hydraulic fluid is associated. A pressurized storage compartment stores the fluid as soon as the temperature-responsive material changes density. The storage compartment is connected with a hydraulic motor, and a valve allows fluid passage from the storage compartment to the hydraulic motor. An energy storage component, e.g. a battery, is connected with the hydraulic motor and is charged by the hydraulic motor when the hydraulic fluid passes through the hydraulic motor. Upon passage in the hydraulic motor, the fluid is stored in a further storage compartment and is then sent back to the area of the temperature-responsive material.

Enhancing heat capacity of colloidal suspension using nanoscale encapsulated phase-change materials for heat transfer.

Science.gov (United States)

Hong, Yan; Ding, Shujiang; Wu, Wei; Hu, Jianjun; Voevodin, Andrey A; Gschwender, Lois; Snyder, Ed; Chow, Louis; Su, Ming

2010-06-01

This paper describes a new method to enhance the heat-transfer property of a single-phase liquid by adding encapsulated phase-change nanoparticles (nano-PCMs), which absorb thermal energy during solid-liquid phase changes. Silica-encapsulated indium nanoparticles and polymer-encapsulated paraffin (wax) nanoparticles have been made using colloid method, and suspended into poly-alpha-olefin (PAO) and water for potential high- and low-temperature applications, respectively. The shells prevent leakage and agglomeration of molten phase-change materials, and enhance the dielectric properties of indium nanoparticles. The heat-transfer coefficients of PAO containing indium nanoparticles (30% by mass) and water containing paraffin nanoparticles (10% by mass) are 1.6 and 1.75 times higher than those of corresponding single-phase fluids. The structural integrity of encapsulation allows repeated use of such nanoparticles for many cycles in high heat generating devices.

Nitrogen-doped Sb-rich Si–Sb–Te phase-change material for high-performance phase-change memory

International Nuclear Information System (INIS)

Zhou, Xilin; Wu, Liangcai; Song, Zhitang; Cheng, Yan; Rao, Feng; Ren, Kun; Song, Sannian; Liu, Bo; Feng, Songlin

2013-01-01

The effects of nitrogen doping on the phase-change performance of Sb-rich Si–Sb–Te materials are systemically investigated, focusing on the chemical state and the role of nitrogen upon crystallization. The tendency of N atoms to bond with Si (SiN x ) in the crystalline film is analyzed by X-ray photoelectron spectroscopy. The microstructures of the materials mixed with Sb 2 Te crystal grains and amorphous Si/SiN x regions are elucidated via in situ transmission electron microscopy, from which a percolation behavior is demonstrated to possibly describe the random crystallization feature in the nucleation-dominated nanocomposite material. The phase-change memory cells based on N-doped Sb-rich Si–Sb–Te materials display more stable and reliable electrical performance than the nitrogen-free ones. An endurance characteristic in the magnitude of 10 7 cycles of the phase-change memory cells is realized with moderate nitrogen addition, meaning that the nitrogen incorporation into Si–Sb–Te material is a suitable method to achieve high-performance phase-change memory for commercial applications

Round-Robin Test of Paraffin Phase-Change Material

Science.gov (United States)

Vidi, S.; Mehling, H.; Hemberger, F.; Haussmann, Th.; Laube, A.

2015-11-01

A round-robin test between three institutes was performed on a paraffin phase-change material (PCM) in the context of the German quality association for phase-change materials. The aim of the quality association is to define quality and test specifications for PCMs and to award certificates for successfully tested materials. To ensure the reproducibility and comparability of the measurements performed at different institutes using different measuring methods, a round-robin test was performed. The sample was unknown. The four methods used by the three participating institutes in the round-robin test were differential scanning calorimetry, Calvet calorimetry and three-layer calorimetry. Additionally, T-history measurements were made. The aim of the measurements was the determination of the enthalpy as a function of temperature. The results achieved following defined test specifications are in excellent agreement.

Defense Nuclear Material Stewardship Integrated Inventory Information Management System (IIIMS).

Energy Technology Data Exchange (ETDEWEB)

Aas, Christopher A.; Lenhart, James E.; Bray, Olin H.; Witcher, Christina Jenkin

2004-11-01

Sandia National Laboratories was tasked with developing the Defense Nuclear Material Stewardship Integrated Inventory Information Management System (IIIMS) with the sponsorship of NA-125.3 and the concurrence of DOE/NNSA field and area offices. The purpose of IIIMS was to modernize nuclear materials management information systems at the enterprise level. Projects over the course of several years attempted to spearhead this modernization. The scope of IIIMS was broken into broad enterprise-oriented materials management and materials forecasting. The IIIMS prototype was developed to allow multiple participating user groups to explore nuclear material requirements and needs in detail. The purpose of material forecasting was to determine nuclear material availability over a 10 to 15 year period in light of the dynamic nature of nuclear materials management. Formal DOE Directives (requirements) were needed to direct IIIMS efforts but were never issued and the project has been halted. When restarted, duplicating or re-engineering the activities from 1999 to 2003 is unnecessary, and in fact future initiatives can build on previous work. IIIMS requirements should be structured to provide high confidence that discrepancies are detected, and classified information is not divulged. Enterprise-wide materials management systems maintained by the military can be used as overall models to base IIIMS implementation concepts upon.

Concepts on integration of physical protection and material accounting functions in a safeguards system

International Nuclear Information System (INIS)

Reynolds, D.A.

1981-01-01

Concepts on integration of physical protection and material accounting systems to enhance overall safeguards capability are developed and presented. Integration is approached by coordinating all safeguards information through a safeguards coordination center. This center represents a higher level in a communication, data-processing, and decision-making structure which is needed for efficient real-time operation of the integrated system. The safeguards coordination center functions to assess alarm and warning data required to resolve threats in the safeguards system, coordinate information and interaction involving the material accounting, physical protection, and facility monitoring and control systems, and present a single unified interface for interaction with facility management, facility operations, safeguards system personnel, and response forces

Material Engineering for Phase Change Memory

Science.gov (United States)

Cabrera, David M.

As semiconductor devices continue to scale downward, and portable consumer electronics become more prevalent there is a need to develop memory technology that will scale with devices and use less energy, while maintaining performance. One of the leading prototypical memories that is being investigated is phase change memory. Phase change memory (PCM) is a non-volatile memory composed of 1 transistor and 1 resistor. The resistive structure includes a memory material alloy which can change between amorphous and crystalline states repeatedly using current/voltage pulses of different lengths and magnitudes. The most widely studied PCM materials are chalcogenides - Germanium-Antimony-Tellerium (GST) with Ge2Sb2Te3 and Germanium-Tellerium (GeTe) being some of the most popular stochiometries. As these cells are scaled downward, the current/voltage needed to switch these materials becomes comparable to the voltage needed to sense the cell's state. The International Roadmap for Semiconductors aims to raise the threshold field of these devices from 66.6 V/mum to be at least 375 V/mum for the year 2024. These cells are also prone to resistance drift between states, leading to bit corruption and memory loss. Phase change material properties are known to influence PCM device performance such as crystallization temperature having an effect on data retention and litetime, while resistivity values in the amorphous and crystalline phases have an effect on the current/voltage needed to write/erase the cell. Addition of dopants is also known to modify the phase change material parameters. The materials G2S2T5, GeTe, with dopants - nitrogen, silicon, titanium, and aluminum oxide and undoped Gallium-Antimonide (GaSb) are studied for these desired characteristics. Thin films of these compositions are deposited via physical vapor deposition at IBM Watson Research Center. Crystallization temperatures are investigated using time resolved x-ray diffraction at Brookhaven National Laboratory

Thermal Vacuum Test of Ice as a Phase Change Material Integrated with a Radiator

Science.gov (United States)

Lee, Steve A.; Leimkuehler, Thomas O.; Stephan, Ryan; Le, Hung V.

2010-01-01

Water may be used as radiation shielding for Solar Particle Events (SPE) to protect crewmembers in the Lunar Electric Rover (LER). Because the water is already present for radiation protection, it could also provide a mass efficient solution to the vehicle's thermal control system. This water can be frozen by heat rejection from a radiator and used as a Phase Change Material (PC1V1) for thermal storage. Use of this water as a PCM can eliminate the need for a pumped fluid loop thermal control system as well as reduce the required size of the radiator. This paper describes the testing and analysis performed for the Rover Engineering Development Unit (REDU), a scaled-down version of a water PCM heat sink for the LER. The REDU was tested in a thermal-vacuum chamber at environmental temperatures similar to those of a horizontal radiator panel on the lunar surface. Testing included complete freeze and melt cycles along with scaled transient heat load profiles simulating a 24-hour day for the rover.

Integrating scientific, economic, and ecological aspects of global change

International Nuclear Information System (INIS)

Jacoby, H.D.; Yang, Z.

1994-01-01

The MIT Joint Program on the Science and Policy of Global Change is conducting research on methods for integrating the science of potential global change with economic analysis of litigation policies and quantification of economic and environmental impacts. The paper describes this work, with a focus on the way that research within the various contributing disciplines, and the design of their associated models, are influenced by the process of inclusion in an integrated framework for policy analysis. The results should contribute new insight into the relative importance of key feedbacks within the economy-climate-ecology system

Recent Advances on Neuromorphic Systems Using Phase-Change Materials

Science.gov (United States)

Wang, Lei; Lu, Shu-Ren; Wen, Jing

2017-05-01

Realization of brain-like computer has always been human's ultimate dream. Today, the possibility of having this dream come true has been significantly boosted due to the advent of several emerging non-volatile memory devices. Within these innovative technologies, phase-change memory device has been commonly regarded as the most promising candidate to imitate the biological brain, owing to its excellent scalability, fast switching speed, and low energy consumption. In this context, a detailed review concerning the physical principles of the neuromorphic circuit using phase-change materials as well as a comprehensive introduction of the currently available phase-change neuromorphic prototypes becomes imperative for scientists to continuously progress the technology of artificial neural networks. In this paper, we first present the biological mechanism of human brain, followed by a brief discussion about physical properties of phase-change materials that recently receive a widespread application on non-volatile memory field. We then survey recent research on different types of neuromorphic circuits using phase-change materials in terms of their respective geometrical architecture and physical schemes to reproduce the biological events of human brain, in particular for spike-time-dependent plasticity. The relevant virtues and limitations of these devices are also evaluated. Finally, the future prospect of the neuromorphic circuit based on phase-change technologies is envisioned.

Recent Advances on Neuromorphic Systems Using Phase-Change Materials.

Science.gov (United States)

Wang, Lei; Lu, Shu-Ren; Wen, Jing

2017-12-01

Realization of brain-like computer has always been human's ultimate dream. Today, the possibility of having this dream come true has been significantly boosted due to the advent of several emerging non-volatile memory devices. Within these innovative technologies, phase-change memory device has been commonly regarded as the most promising candidate to imitate the biological brain, owing to its excellent scalability, fast switching speed, and low energy consumption. In this context, a detailed review concerning the physical principles of the neuromorphic circuit using phase-change materials as well as a comprehensive introduction of the currently available phase-change neuromorphic prototypes becomes imperative for scientists to continuously progress the technology of artificial neural networks. In this paper, we first present the biological mechanism of human brain, followed by a brief discussion about physical properties of phase-change materials that recently receive a widespread application on non-volatile memory field. We then survey recent research on different types of neuromorphic circuits using phase-change materials in terms of their respective geometrical architecture and physical schemes to reproduce the biological events of human brain, in particular for spike-time-dependent plasticity. The relevant virtues and limitations of these devices are also evaluated. Finally, the future prospect of the neuromorphic circuit based on phase-change technologies is envisioned.

Numerical Analysis of the Influence of Thermal Mass, Phase Change Materials and Furniture / Indoor Content on Building Energy Flexibility

DEFF Research Database (Denmark)

Johra, Hicham; Heiselberg, Per Kvols; Dreau, Jerome Le

2017-01-01

Many numerical models for building energy simulation assume empty rooms and do not account for the indoor content of occupied buildings. Furnishing elements and indoor items have complicated shapes and are made of various materials. Therefore, most of the people prefer to ignore them. However, th......, it is shown that the integration of phase change materials in wallboards or furniture elements can appreciably improve the energy flexibility of buildings.......Many numerical models for building energy simulation assume empty rooms and do not account for the indoor content of occupied buildings. Furnishing elements and indoor items have complicated shapes and are made of various materials. Therefore, most of the people prefer to ignore them. However...

EDDA 1.0: integrated simulation of debris flow erosion, deposition and property changes

Science.gov (United States)

Chen, H. X.; Zhang, L. M.

2015-03-01

Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA (Erosion-Deposition Debris flow Analysis), is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during the flow process. The yield stress of the debris flow mixture determined at limit equilibrium using the Mohr-Coulomb equation is applicable to clear water flow, hyper-concentrated flow and fully developed debris flow. To assure numerical stability and computational efficiency at the same time, an adaptive time stepping algorithm is developed to solve the governing differential equations. Four numerical tests are conducted to validate the model. The first two tests involve a one-dimensional debris flow with constant properties and a two-dimensional dam-break water flow. The last two tests involve erosion and deposition, and the movement of multi-directional debris flows. The changes in debris flow mass and properties due to either erosion or deposition are shown to affect the runout characteristics significantly. The model is also applied to simulate a large-scale debris flow in Xiaojiagou Ravine to test the performance of the model in catchment-scale simulations. The results suggest that the model estimates well the volume, inundated area, and runout distance of the debris flow. The model is intended for use as a module in a real-time debris flow warning system.

Study on the Standard Establishment for the Integrity Assessment of Nuclear Fuel Cladding Materials

Energy Technology Data Exchange (ETDEWEB)

Kang, S-S; Kim, S-H; Jung, Y-K; Yang, C-Y; Kim, I-G; Choi, Y-H; Kim, H-J; Kim, M-W; Rho, B-H [KINS, Daejeon (Korea, Republic of)

2008-02-15

Fuel cladding material plays important role as a primary structure under the high temperature, high pressure and neutron environment of nuclear power plant. According to this environment, cladding material can be experienced several type aging phenomena including the neutron irradiation embrittlement. On the other hand, although the early nuclear power plant was designed to fitting into the 40MWd/KgU burn-up, the currently power plant intends to go to the high burn-up range. In this case, the safety criteria which was established at low burn-up needs to conform the applicability at the high burn-up. In this study, the safety criteria of fuel cladding material was reviewed to assess the cladding material integrity, and the material characteristics of cladding were reviewed. The current LOCA criterial was also reviewed, and the basic study for re-establishment of LOCA criteria was performed. The time concept safety criteria was also discussed to prevent the breakaway oxidation. Through the this study, safety issues will be produced and be helpful for integrity insurance of nuclear fuel cladding material. This report is the final report.

Portable Thermoelectric Power Generator Coupled with Phase Change Material

Directory of Open Access Journals (Sweden)

Lim Chong C.

2014-07-01

Full Text Available Solar is the intermittent source of renewable energy and all thermal solar systems having a setback on non-functioning during the night and cloudy environment. This paper presents alternative solution for power generation using thermoelectric which is the direct conversion of temperature gradient of hot side and cold side of thermoelectric material to electric voltage. Phase change material with latent heat effect would help to prolong the temperature gradient across thermoelectric material for power generation. Besides, the concept of portability will enable different power source like solar, wasted heat from air conditioner, refrigerator, stove etc, i.e. to create temperature different on thermoelectric material for power generation. Furthermore, thermoelectric will generate direct current which is used by all the gadgets like Smartphone, tablet, laptop etc. The portable concept of renewable energy will encourage the direct usage of renewable energy for portable gadgets. The working principle and design of portable thermoelectric power generator coupled with phase change material is presented in this paper.

Phase change thermal control materials, method and apparatus

Science.gov (United States)

Buckley, Theresa M. (Inventor)

2001-01-01

An apparatus and method for metabolic cooling and insulation of a user in a cold environment. In its preferred embodiment the apparatus is a highly flexible composite material having a flexible matrix containing a phase change thermal storage material. The apparatus can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The apparatus may also include an external thermal insulation layer and/or an internal thermal control layer to regulate the rate of heat exchange between the composite and the skin of the wearer. Other embodiments of the apparatus also provide 1) a path for evaporation or direct absorption of perspiration from the skin of the wearer for improved comfort and thermal control, 2) heat conductive pathways within the material for thermal equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal socks, gloves and a face mask for cold weather activities, and a metabolic heating or cooling blanket useful for treating hypothermia or fever patients in a medical setting and therapeutic heating or cooling orthopedic joint supports.

Novel dynamic thermal characterization of multifunctional concretes with microencapsulated phase change materials

Science.gov (United States)

Pisello, Anna Laura; Fabiani, Claudia; D'Alessandro, Antonella; Cabeza, Luisa F.; Ubertini, Filippo; Cotana, Franco

2017-04-01

Concrete is widely applied in the construction sector for its reliable mechanical performance, its easiness of use and low costs. It also appears promising for enhancing the thermal-energy behavior of buildings thanks to its capability to be doped with multifunctional fillers. In fact, key studies acknowledged the benefits of thermally insulated concretes for applications in ceilings and walls. At the same time, thermal capacity also represents a key property to be optimized, especially for lightweight constructions. In this view, Thermal-Energy Storage (TES) systems have been recently integrated into building envelopes for increasing thermal inertia. More in detail, numerical experimental investigations showed how Phase Change materials (PCMs), as an acknowledged passive TES strategy, can be effectively included in building envelope, with promising results in terms of thermal buffer potentiality. In particular, this work builds upon previous papers aimed at developing the new PCM-filled concretes for structural applications and optimized thermalenergy efficiency, and it is focused on the development of a new experimental method for testing such composite materials in thermal-energy dynamic conditions simulated in laboratory by exposing samples to environmentally controlled microclimate while measuring thermal conductivity and diffusivity by means of transient plane source techniques. The key findings show how the new composites are able to increasingly delay the thermal wave with increasing the PCM concentration and how the thermal conductivity varies during the course of the phase change, in both melting and solidification processes. The new analysis produces useful findings in proposing an effective method for testing composite materials with adaptive thermal performance, much needed by the scientific community willing to study building envelopes dynamics.

Cementitious building material incorporating end-capped polyethylene glycol as a phase change material

Science.gov (United States)

Salyer, Ival O.; Griffen, Charles W.

1986-01-01

A cementitious composition comprising a cementitious material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the compositions are useful in making pre-formed building materials such as concrete blocks, brick, dry wall and the like or in making poured structures such as walls or floor pads; the glycols can be encapsulated to reduce their tendency to retard set.

Computer aided process planning system based on workflow technology and integrated bill of material tree

Institute of Scientific and Technical Information of China (English)

LU Chun-guang; MENG Li-li

2006-01-01

It is extremely important for procedure of process design and management of process data for product life cycle in Computer Aided Process Planning (CAPP) system,but there are many shortcomings with traditional CAPP system in these respects.To solve these questions,application of workflow technology in CAPP system based on web-integrated Bill of Material (BOM) tree is discussed,and a concept of integrated BOM tree was brought forward.Taking integrated BOM as the thread,CAPP systematic technological process is analyzed.The function,system architecture,and implementation mechanism of CAPP system based on Browser/Server and Customer/Server model are expatiated.Based on it,the key technologies of workflow management device were analyzed.Eventually,the implementation mechanism of integrated BOM tree was analyzed from viewpoints of material information encoding,organization node design of integrated BOM tree,transformation from Engineering BOM (EBOM)to Process BOM (PBOM),and the programming implementation technology.

Integrated Decision Support for Global Environmental Change Adaptation

Science.gov (United States)

Kumar, S.; Cantrell, S.; Higgins, G. J.; Marshall, J.; VanWijngaarden, F.

2011-12-01

Environmental changes are happening now that has caused concern in many parts of the world; particularly vulnerable are the countries and communities with limited resources and with natural environments that are more susceptible to climate change impacts. Global leaders are concerned about the observed phenomena and events such as Amazon deforestation, shifting monsoon patterns affecting agriculture in the mountain slopes of Peru, floods in Pakistan, water shortages in Middle East, droughts impacting water supplies and wildlife migration in Africa, and sea level rise impacts on low lying coastal communities in Bangladesh. These environmental changes are likely to get exacerbated as the temperatures rise, the weather and climate patterns change, and sea level rise continues. Large populations and billions of dollars of infrastructure could be affected. At Northrop Grumman, we have developed an integrated decision support framework for providing necessary information to stakeholders and planners to adapt to the impacts of climate variability and change at the regional and local levels. This integrated approach takes into account assimilation and exploitation of large and disparate weather and climate data sets, regional downscaling (dynamic and statistical), uncertainty quantification and reduction, and a synthesis of scientific data with demographic and economic data to generate actionable information for the stakeholders and decision makers. Utilizing a flexible service oriented architecture and state-of-the-art visualization techniques, this information can be delivered via tailored GIS portals to meet diverse set of user needs and expectations. This integrated approach can be applied to regional and local risk assessments, predictions and decadal projections, and proactive adaptation planning for vulnerable communities. In this paper we will describe this comprehensive decision support approach with selected applications and case studies to illustrate how this

Index change of chalcogenide materials from precision glass molding processes

Science.gov (United States)

Deegan, J.; Walsh, K.; Lindberg, G.; Benson, R.; Gibson, D.; Bayya, S.; Sanghera, J.; Stover, E.

2015-05-01

With the increase in demand for infrared optics for thermal applications and the use of glass molding of chalcogenide materials to support these higher volume optical designs, an investigation of changes to the optical properties of these materials is required. Typical precision glass molding requires specific thermal conditions for proper lens molding of any type of optical glass. With these conditions a change (reduction) of optical index occurs after molding of all oxide glass types and it is presumed that a similar behavior will happen with chalcogenide based materials. We will discuss the effects of a typical molding thermal cycle for use with commercially and newly developed chalcogenide materials and show results of index variation from nominally established material data.

Ecological performance of construction materials subject to ocean climate change.

Science.gov (United States)

Davis, Kay L; Coleman, Melinda A; Connell, Sean D; Russell, Bayden D; Gillanders, Bronwyn M; Kelaher, Brendan P

2017-10-01

Artificial structures will be increasingly utilized to protect coastal infrastructure from sea-level rise and storms associated with climate change. Although it is well documented that the materials comprising artificial structures influence the composition of organisms that use them as habitat, little is known about how these materials may chemically react with changing seawater conditions, and what effects this will have on associated biota. We investigated the effects of ocean warming, acidification, and type of coastal infrastructure material on algal turfs. Seawater acidification resulted in greater covers of turf, though this effect was counteracted by elevated temperatures. Concrete supported a greater cover of turf than granite or high-density polyethylene (HDPE) under all temperature and pH treatments, with the greatest covers occurring under simulated ocean acidification. Furthermore, photosynthetic efficiency under acidification was greater on concrete substratum compared to all other materials and treatment combinations. These results demonstrate the capacity to maximise ecological benefits whilst still meeting local management objectives when engineering coastal defense structures by selecting materials that are appropriate in an ocean change context. Therefore, mitigation efforts to offset impacts from sea-level rise and storms can also be engineered to alter, or even reduce, the effects of climatic change on biological assemblages. Copyright © 2017 Elsevier Ltd. All rights reserved.

A review on phase change energy storage: materials and applications

International Nuclear Information System (INIS)

Farid, Mohammed M.; Khudhair, Amar M.; Razack, Siddique Ali K.; Al-Hallaj, Said

2004-01-01

Latent heat storage is one of the most efficient ways of storing thermal energy. Unlike the sensible heat storage method, the latent heat storage method provides much higher storage density, with a smaller temperature difference between storing and releasing heat. This paper reviews previous work on latent heat storage and provides an insight to recent efforts to develop new classes of phase change materials (PCMs) for use in energy storage. Three aspects have been the focus of this review: PCM materials, encapsulation and applications. There are large numbers of phase change materials that melt and solidify at a wide range of temperatures, making them attractive in a number of applications. Paraffin waxes are cheap and have moderate thermal energy storage density but low thermal conductivity and, hence, require large surface area. Hydrated salts have larger energy storage density and higher thermal conductivity but experience supercooling and phase segregation, and hence, their application requires the use of some nucleating and thickening agents. The main advantages of PCM encapsulation are providing large heat transfer area, reduction of the PCMs reactivity towards the outside environment and controlling the changes in volume of the storage materials as phase change occurs. The different applications in which the phase change method of heat storage can be applied are also reviewed in this paper. The problems associated with the application of PCMs with regards to the material and the methods used to contain them are also discussed

Cold storage with phase change material for building ventilation

OpenAIRE

Butala, Vincenc; Stritih, Uroš

2015-01-01

This paper presents an experimental and numerical analysis of building coolingusing night-time cold accumulation in phase change material (PCM), otherwise known as the "free-cooling" or "passive-cooling" principle. The phase change materials were used in ceilings and floors. The free-cooling principle is explained and some of the types of PCMs suitable for summer cooling are listed. An experiment was conducted using paraffin with a melting point of 22 °C as the PCM to store cold during the ni...

The implementation of integrated entrepreneurship material on dress making teaching in vocational high school

Science.gov (United States)

Sawitri, Sicilia

2018-03-01

The aims of the research were: (1) To know the students' achievement in Dress Making Teaching by implementing Integrated Entrepreneur Material in Vocational High School, (2) The level of increasing of students' achievement in Dress Making Teaching by integrating Entrepreneurship Material in Vocational High School. By using experimental method this research was conducted in Magelang Vocational High School and applied pre-test post-test design. The samples in this research was XI grade of Fashion Technology Study Program. Observation sheet and documentation were used in this research as instruments. Data analyzed by using descriptive analyze and gain score. The result, there were: (1) students' achievement in Dress Making Teaching was high 88.6 and (2) the increasing of students' achievement was 0.61 it was medium category. The suggestion were: Integrated Entrepreneurship material can be applied in another subject matter, such as Men Wear, Tailoring, Children Wear, and The students who want to be a good entrepreneur, have to drill their skill in making dresses, and know about excellent service to the clients, marketing and make clients satisfaction.

III-nitride integration on ferroelectric materials of lithium niobate by molecular beam epitaxy

International Nuclear Information System (INIS)

Namkoong, Gon; Lee, Kyoung-Keun; Madison, Shannon M.; Henderson, Walter; Ralph, Stephen E.; Doolittle, W. Alan

2005-01-01

Integration of III-nitride electrical devices on the ferroelectric material lithium niobate (LiNbO 3 ) has been demonstrated. As a ferroelectric material, lithium niobate has a polarization which may provide excellent control of the polarity of III-nitrides. However, while high temperature, 1000 deg. C, thermal treatments produce atomically smooth surfaces, improving adhesion of GaN epitaxial layers on lithium niobate, repolarization of the substrate in local domains occurs. These effects result in multi domains of mixed polarization in LiNbO 3 , producing inversion domains in subsequent GaN epilayers. However, it is found that AlN buffer layers suppress inversion domains of III-nitrides. Therefore, two-dimensional electron gases in AlGaN/GaN heterojunction structures are obtained. Herein, the demonstration of the monolithic integration of high power devices with ferroelectric materials presents possibilities to control LiNbO 3 modulators on compact optoelectronic/electronic chips

Variation of Bragg curve characteristic induced by changing the position of inhomogeneous material: Geant4 simulation study

Energy Technology Data Exchange (ETDEWEB)

Park, So-Hyun; Jung, Won-Gyun; Suh, Tae-Suk [Catholic University, Seoul (Korea, Republic of); Jang, Hong-Seok; Choi, Byeong-Oak [Seoul St. Mary' s Hospital, Seoul (Korea, Republic of); Rah, Jeong-Eun; Park, Sun-Gyong; Lee, Se-Byeong [National Cancer Center, Ilsan (Korea, Republic of)

2011-02-15

When proton beam passes through the human body, the stopping power and the depth-dose distribution of the proton are influenced by the relative location among adjacent materials or the difference in material conditions. Our study demonstrates the effect of inhomogeneous materials placed in the Plateau and Bragg peak regions of the Bragg curve in water. We evaluated the Bragg peak position, range, penumbra and integrated doses by using the Geant4 simulation toolkit. The positions of inhomogeneities were selected as the proximal 36% and 50% points of the maximum dose, which indicates the location at entrance regions of the Plateau and the Bragg peak, respectively. Bone (density {rho} = 1.85 g/cm{sup 3}) and adipose tissue (density {rho} = 0.92 g/cm{sup 3}) were selected as inhomogeneous materials. The thickness of each material was varied by 0.1 cm between 0.1 cm and 1.0 cm. In addition, the initial energy of the proton beam was changed in 30 MeV steps between 108 MeV and 220 MeV. The effects of inhomogeneous conditions were performed for various parameters: Bragg peak position, range, penumbra width, full width at half maximum and dose of Bragg curve. A dose perturbation was observed in the region of the Bragg peak and inhomogeneous material, especially, When the bone equivalent material was inserted within the Bragg curve. However, there were no significant variations in the other parameters, except for the dose perturbation depending on the inserted location of each material. This study shows the characteristic changes in the Bragg curve due to inhomogeneous materials.

Examining Changes of Preservice Teachers' Beliefs about Technology Integration during Student Teaching

Science.gov (United States)

Hsu, Pi-Sui

2013-01-01

The purpose of this qualitative case study was to examine changes in preservice teachers' beliefs about technology integration during the student teaching semester in USA. This study used in-depth interviews, review of documents, and observations. The findings indicated the preservice teachers' beliefs about technology integration changed in two…

In a Time of Change: Integrating the Arts and Humanities with Climate Change Science in Alaska

Science.gov (United States)

Leigh, M.; Golux, S.; Franzen, K.

2011-12-01

The arts and humanities have a powerful capacity to create lines of communication between the public, policy and scientific spheres. A growing network of visual and performing artists, writers and scientists has been actively working together since 2007 to integrate scientific and artistic perspectives on climate change in interior Alaska. These efforts have involved field workshops and collaborative creative processes culminating in public performances and a visual art exhibit. The most recent multimedia event was entitled In a Time of Change: Envisioning the Future, and challenged artists and scientists to consider future scenarios of climate change. This event included a public performance featuring original theatre, modern dance, Alaska Native Dance, poetry and music that was presented concurrently with an art exhibit featuring original works by 24 Alaskan visual artists. A related effort targeted K12 students, through an early college course entitled Climate Change and Creative Expression, which was offered to high school students at a predominantly Alaska Native charter school and integrated climate change science, creative writing, theatre and dance. Our program at Bonanza Creek Long Term Ecological Research (LTER) site is just one of many successful efforts to integrate arts and humanities with science within and beyond the NSF LTER Program. The efforts of various LTER sites to engage the arts and humanities with science, the public and policymakers have successfully generated excitement, facilitated mutual understanding, and promoted meaningful dialogue on issues facing science and society. The future outlook for integration of arts and humanities with science appears promising, with increasing interest from artists, scientists and scientific funding agencies.

Phase Change Materials and the perception of wetness.

NARCIS (Netherlands)

Bergmann Tiest, W.M.; Kappers, A.M.L.; Daanen, H.A.M.

2012-01-01

Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

Phase change materials and the perception of wetness

NARCIS (Netherlands)

Bergmann Tiest, W.M.; Kosters, N.D.; Kappers, A.M.L.; Daanen, H.A.M.

2012-01-01

Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

Preparation and characterization of novel anion phase change heat storage materials.

Science.gov (United States)

Hong, Wei; Lil, Qingshan; Sun, Jing; Di, Youbo; Zhao, Zhou; Yu, Wei'an; Qu, Yuan; Jiao, TiFeng; Wang, Guowei; Xing, Guangzhong

2013-10-01

In this paper, polyurethane phase change material was successfully prepared with TDI with BDO for hard segments and PEG for soft segments. Moreover, based on this the solid-solid phase change material, A-PCM1030 which can release anions was prepared with the successful addition of anion additives A1030 for the first time. Then the test of the above material was conducted utilizing FT-IR, DSC, TEM, WAXD and Air Ion Detector. The Results indicated that the polyurethane phase change material possesses excellent thermal stability since there was no appearance of liquid leakage and phase separation after 50 times warming-cooling thermal cycles. It also presented reversibility on absorbing and releasing heat. In addition, adding a little A1030 can increase the thermal stability and reduce phase transition temperatures, as well as reduce the undercooling of the polyurethane phase change material. In addition, the anion test results suggested that the supreme amount of anion released by A-PCM1030 could reach 2510 anions/cm3 under dynamic conditions, which is beneficial for human health.

Study on the standard establishment for the integrity assessment of nuclear fuel cladding Materials

Energy Technology Data Exchange (ETDEWEB)

Kang, S. S.; Kim, S. H.; Jung, Y. K.; Yang, C. Y.; Kim, I. G.; Choi, Y. H.; Kim, H. J.; Kim, M. W.; Rho, B. H. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2007-02-15

Fuel cladding material plays important role as a primary structure under the high temperature, high pressure and neutron environment of nuclear power plant. According to this environment, cladding material can be experienced several type aging phenomena including the neutron irradiation embrittlement. On the other hand, although the early nuclear power plant was designed to fitting into the 40MWd/KgU burn-up, the currently power plant intends to go to the high burn-up range. In this case, the safety criteria which was established at low burn-up needs to conform the applicability at the high burn-up. In this study, the safety criteria of fuel cladding material was reviewed to assess the cladding material integrity, and the material characteristics of cladding were reviewed. The current LOCA criterial was also reviewed, and the basic study for re-establishment of LOCA criteria was performed. The time concept safety criteria was also discussed to prevent the breakaway oxidation. Through the this study, safety issues will be produced and be helpful for integrity insurance of nuclear fuel cladding material. This report is 2nd term report.

Phase Change Materials for Thermal Energy Storage

OpenAIRE

Stiebra, L; Cabulis, U; Knite, M

2014-01-01

Phase change materials (PCMs) for thermal energy storage (TES) have become an important subject of research in recent years. Using PCMs for thermal energy storage provides a solution to increase the efficiency of the storage and use of energy in many domestic and industrial sectors. Phase change TES systems offer a number of advantages over other systems (e.g. chemical storage systems): particularly small temperature distance between the storage and retrieval cycles, small unit sizes and lo...

Beeswax as phase change material to improve solar panel’s performance

Science.gov (United States)

Thaib, R.; Rizal, S.; Riza, M.; Mahlia, T. M. I.; Rizal, T. A.

2018-02-01

One of the main obstacles faced during the operation of photovoltaic (PV) panels was overheating due to excessive solar radiation and high ambient temperatures. In this research, investigates the use of beeswax phase change materials (PCM) to maintain the temperature of the panels close to ambient. Solar panels used in this study has 839 mm length, 537 mm wide, and 50 mm thick, with maximum output power at 50 W. During the study, there were two solar panels was evaluated, one without phase change material while the other one was using beeswax phase change material. Solar panels were mounted at 15° slope. Variables observed was the temperature of solar panel’s surface, output voltage and current that produced by PV panels, wind speed around solar panels, and solar radiation. The observation was started at 07:00 am and ended at 06:00 pm. The research shows that maximum temperature of solar panels surface without phase change material is ranging between 46-49 °C, and electrical efficiency is about 7.2-8.8%. Meanwhile, for solar panels with beeswax phase change material, the maximum temperature solar panels surface is relatively low ranging between 33-34 °C, and its electrical efficiency seems to increase about 9.1-9.3%.

Study on paraffin/expanded graphite composite phase change thermal energy storage material

International Nuclear Information System (INIS)

Zhang Zhengguo; Fang Xiaoming

2006-01-01

A paraffin/expanded graphite composite phase change thermal energy storage material was prepared by absorbing the paraffin into an expanded graphite that has an excellent absorbability. In such a composite, the paraffin serves as a latent heat storage material and the expanded graphite acts as the supporting material, which prevents leakage of the melted paraffin from its porous structure due to the capillary and surface tension forces. The inherent structure of the expanded graphite did not change in the composite material. The solid-liquid phase change temperature of the composite PCM was the same as that of the paraffin, and the latent heat of the paraffin/expanded graphite composite material was equivalent to the calculated value based on the mass ratio of the paraffin in the composite. The heat transfer rate of the paraffin/expanded graphite composite was obviously higher than that of the paraffin due to the combination with the expanded graphite that had a high thermal conductivity. The prepared paraffin/expanded graphite composite phase change material had a large thermal storage capacity and improved thermal conductivity and did not experience liquid leakage during its solid-liquid phase change

State of the art on phase change material slurries

International Nuclear Information System (INIS)

Youssef, Ziad; Delahaye, Anthony; Huang Li; Trinquet, François; Fournaison, Laurence; Pollerberg, Clemens; Doetsch, Christian

2013-01-01

Highlights: ► A bibliographic study on PCM slurries. ► Clathrate Hydrate slurry, Microencapsulated PCM Slurry, shape-stabilized PCM slurries and Phase Change Material Emulsions. ► Formation, thermo-physical, rheological, heat transfers properties and applications of these four PCS systems. ► The use of thermal energy storage and distribution based on PCM slurries can improve the refrigerating machine performances. - Abstract: The interest in using phase change slurry (PCS) media as thermal storage and heat transfer fluids is increasing and thus leading to an enhancement in the number of articles on the subject. In air-conditioning and refrigeration applications, PCS systems represent a pure benefit resulting in the increase of thermal energy storage capacity, high heat transfer characteristics and positive phase change temperatures which can occur under low pressures. Hence, they allow the increase of energy efficiency and reduce the quantity of thermal fluids. This review describes the formation, thermo-physical, rheological, heat transfer properties and applications of four PCS systems: Clathrate hydrate slurry (CHS), Microencapsulated Phase Change Materials Slurry (MPCMS), shape-stabilized PCM slurries (SPCMSs) and Phase Change Material Emulsions (PCMEs). It regroups a bibliographic summary of important information that can be very helpful when such systems are used. It also gives interesting and valuable insights on the choice of the most suitable PCS media for laboratory and industrial applications.

Optimization of a phase change material wallboard for building use

International Nuclear Information System (INIS)

Kuznik, Frederic; Virgone, Joseph; Noel, Jean

2008-01-01

In construction, the use of phase change materials (PCM) allows the storage/release of energy from the solar radiation and/or internal loads. The application of such materials for lightweight construction (e.g., a wood house) makes it possible to improve thermal comfort and reduce energy consumption. A wallboard composed of a new PCM material is investigated in this paper to enhance the thermal behavior of a lightweight internal partition wall. The paper focuses on the optimization of phase change material thickness. The in-house software CODYMUR is used to optimize the PCM wallboard by the means of numerical simulations. The results show that an optimal PCM thickness exists. The optimal PCM thickness value is then calculated for use in construction

Optimization of a phase change material wallboard for building use

Energy Technology Data Exchange (ETDEWEB)

Kuznik, Frederic; Virgone, Joseph [Thermal Sciences Center of Lyon, CNRS, UMR 5008, INSA de Lyon, Universite Lyon 1, Bat Freyssinet, 40 Rue des Arts, 69621 Villeurbanne Cedex (France); Noel, Jean [Free-lance Scientific Software Developer, 15 Place Carnot, 69002 Lyon (France)

2008-08-15

In construction, the use of phase change materials (PCM) allows the storage/release of energy from the solar radiation and/or internal loads. The application of such materials for lightweight construction (e.g., a wood house) makes it possible to improve thermal comfort and reduce energy consumption. A wallboard composed of a new PCM material is investigated in this paper to enhance the thermal behavior of a lightweight internal partition wall. The paper focuses on the optimization of phase change material thickness. The in-house software CODYMUR is used to optimize the PCM wallboard by the means of numerical simulations. The results show that an optimal PCM thickness exists. The optimal PCM thickness value is then calculated for use in construction. (author)

Integration of Magneto-Optical Materials for Novel Optical Devices & Magnetophotonic Crystals, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This work proposes to capitalize on our Phase I success in monolithically integrating magneto-optic and magnetic materials with semiconductor platforms in order to...

Interdisciplinary Climate Change Curriculum Materials based on the Next Generation Science Standards and The Earth Charter

Science.gov (United States)

Barbosa, A.; Robertson, W. H.

2013-12-01

In the 2012, the National Research Council (NRC) of the National Academies' reported that one of the major issues associated with the development of climate change curriculum was the lack of interdisciplinary materials that also promoted a correlation between science standards and content. Therefore, in order to respond to this need, our group has developed an interdisciplinary climate change curriculum that has had as its fundamental basis the alignment with the guidelines presented by the Next Generation Science Standards (NGSS) and the ones presented by the international document entitled The Earth Charter. In this regards, while the alignment with NGSS disciplinary core ideas, cross-concepts and students' expectations intended to fulfill the need for the development of climate change curriculum activities that were directly associated with the appropriate set of NGSS guidelines, the alignment with The Earth Charter document intended to reinforce the need the for the integration of sociological, philosophical and intercultural analysis of the theme 'climate change'. Additionally, our curriculum was also developed as part of a collaborative project between climate scientists and engineers, who are responsible for the development of a Regional Arctic Simulation Model (RASM). Hence, another important curriculum constituent was the feedback, suggestions and reviews provided by these professionals, who have also contributed to these pedagogical materials' scientific accuracy by facilitating the integration of datasets and visualizations developed by RASM. Furthermore, our group has developed a climate change curriculum for two types of audience: high school and early undergraduate students. Each curriculum unit is divided into modules and each module contains a set of lesson plans. The topics selected to compose each unit and module were designated according to the surveys conducted with scientists and engineers involved with the development of the climate change

Reasons for change - Today's material management

International Nuclear Information System (INIS)

Guilbeault, B.D.; Bargerstock, S.B.

1992-01-01

The current generation of nuclear power plants is approaching middle age. The industry continues to stabilize and mature as this occurs, which creates new areas of focus. This evolution is placing a much greater emphases on the business aspects of the operation and maintenance functions. One area that can provide a reasonable return to the operating organizations is materials management. Florida Power and Light Company has experienced these reasons for change. A new department was formed as part of the Nuclear Division in 1990. Performance improvement tasks were established using goals and objectives consistent with plant support and business requirements. Two of the primary processes within the materials management area control the largest portion of costs to operating budgets: the procurement process and inventory management

Climate change, uncertainty, and resilient fisheries: Institutional responses through integrative science

DEFF Research Database (Denmark)

Miller, K.; Charles, A.; Barange, M.

2010-01-01

This paper explores the importance of a focus on the fundamental goals of resilience and adaptive capacity in the governance of uncertain fishery systems, particularly in the context of climate change. Climate change interacts strongly with fishery systems, and adds to the inherent uncertainty...... that understanding these aspects of fishery systems and fishery governance is valuable even in the absence of climate-induced processes of change, but that attention to climate change both reinforces the need for, and facilitates the move toward, implementation of integrative science for improved fishery governance....... and processes – to support suitable institutional responses, a broader planning perspective, and development of suitable resilience-building strategies. The paper explores how synergies between institutional change and integrative science can facilitate the development of more effective fisheries policy...

Translucency changes of direct esthetic restorative materials after curing, aging and treatment

Directory of Open Access Journals (Sweden)

Yong-Keun Lee

2016-11-01

Full Text Available The purpose of this article was to review the changes in translucency of direct esthetic restorative materials after curing, aging and treatment. As a criterion for the evaluation of clinical translucency changes, visual perceptibility threshold in translucency parameter difference (ΔTP of 2 was used. Translucency changes after curing were perceivable depending on experimental methods and products (largest ΔTP in resin composites = 15.9. Translucency changes after aging were reported as either relatively stable or showed perceivable changes by aging protocols (largest ΔTP in resin composites = -3.8. Translucency changes after curing, aging and treatment were perceivable in several products and experimental methods. Therefore, shade matching of direct esthetic materials should be performed considering these instabilities of translucency in direct esthetic materials.

Production integrated nondestructive testing of composite materials and material compounds - an overview

Science.gov (United States)

Straß, B.; Conrad, C.; Wolter, B.

2017-03-01

Composite materials and material compounds are of increasing importance, because of the steadily rising relevance of resource saving lightweight constructions. Quality assurance with appropriate Nondestructive Testing (NDT) methods is a key aspect for reliable and efficient production. Quality changes have to be detected already in the manufacturing flow in order to take adequate corrective actions. For materials and compounds the classical NDT methods for defectoscopy, like X-ray and Ultrasound (US) are still predominant. Nevertheless, meanwhile fast, contactless NDT methods, like air-borne ultrasound, dynamic thermography and special Eddy-Current techniques are available in order to detect cracks, voids, pores and delaminations but also for characterizing fiber content, distribution and alignment. In Metal-Matrix Composites US back-scattering can be used for this purpose. US run-time measurements allow the detection of thermal stresses at the metal-matrix interface. Another important area is the necessity for NDT in joining. To achieve an optimum material utilization and product safety as well as the best possible production efficiency, there is a need for NDT methods for in-line inspection of the joint quality while joining or immediately afterwards. For this purpose EMAT (Electromagnetic Acoustic Transducer) technique or Acoustic Emission testing can be used.

Design rules for phase-change materials in data storage applications

Energy Technology Data Exchange (ETDEWEB)

Lencer, Dominic; Salinga, Martin [I. Physikalisches Institut IA, RWTH Aachen University, 52056 Aachen (Germany); Wuttig, Matthias [I. Physikalisches Institut IA, RWTH Aachen University, 52056 Aachen (Germany); Juelich-Aachen Research Alliance, Section Fundamentals of Future Information Technology (JARA-FIT), 52056 Aachen (Germany)

2011-05-10

Phase-change materials can rapidly and reversibly be switched between an amorphous and a crystalline phase. Since both phases are characterized by very different optical and electrical properties, these materials can be employed for rewritable optical and electrical data storage. Hence, there are considerable efforts to identify suitable materials, and to optimize them with respect to specific applications. Design rules that can explain why the materials identified so far enable phase-change based devices would hence be very beneficial. This article describes materials that have been successfully employed and discusses common features regarding both typical structures and bonding mechanisms. It is shown that typical structural motifs and electronic properties can be found in the crystalline state that are indicative for resonant bonding, from which the employed contrast originates. The occurence of resonance is linked to the composition, thus providing a design rule for phase-change materials. This understanding helps to unravel characteristic properties such as electrical and thermal conductivity which are discussed in the subsequent section. Then, turning to the transition kinetics between the phases, the current understanding and modeling of the processes of amorphization and crystallization are discussed. Finally, present approaches for improved high-capacity optical discs and fast non-volatile electrical memories, that hold the potential to succeed present-day's Flash memory, are presented. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Design rules for phase-change materials in data storage applications.

Science.gov (United States)

Lencer, Dominic; Salinga, Martin; Wuttig, Matthias

2011-05-10

Phase-change materials can rapidly and reversibly be switched between an amorphous and a crystalline phase. Since both phases are characterized by very different optical and electrical properties, these materials can be employed for rewritable optical and electrical data storage. Hence, there are considerable efforts to identify suitable materials, and to optimize them with respect to specific applications. Design rules that can explain why the materials identified so far enable phase-change based devices would hence be very beneficial. This article describes materials that have been successfully employed and dicusses common features regarding both typical structures and bonding mechanisms. It is shown that typical structural motifs and electronic properties can be found in the crystalline state that are indicative for resonant bonding, from which the employed contrast originates. The occurence of resonance is linked to the composition, thus providing a design rule for phase-change materials. This understanding helps to unravel characteristic properties such as electrical and thermal conductivity which are discussed in the subsequent section. Then, turning to the transition kinetics between the phases, the current understanding and modeling of the processes of amorphization and crystallization are discussed. Finally, present approaches for improved high-capacity optical discs and fast non-volatile electrical memories, that hold the potential to succeed present-day's Flash memory, are presented. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Constraints on the Adiabatic Temperature Change in Magnetocaloric Materials

DEFF Research Database (Denmark)

Nielsen, Kaspar Kirstein; Bahl, Christian Robert Haffenden; Smith, Anders

2010-01-01

The thermodynamics of the magnetocaloric effect implies constraints on the allowed variation in the adiabatic temperature change for a magnetocaloric material. An inequality for the derivative of the adiabatic temperature change with respect to temperature is derived for both first- and second...

Material Protection, Accounting, and Control Technologies (MPACT) Advanced Integration Roadmap

Energy Technology Data Exchange (ETDEWEB)

Durkee, Joe W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cipiti, Ben [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Demuth, Scott Francis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fallgren, Andrew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jarman, Ken [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Shelly [Argonne National Lab. (ANL), Argonne, IL (United States); Meier, Dave [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miller, Mike [Argonne National Lab. (ANL), Argonne, IL (United States); Osburn, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Dasari, Venkateswara Rao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ticknor, Lawrence O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yoo, Tae-Sic [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-09-30

The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal (Miller, 2015). This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools will consist of instrumentation and devices as well as computer software for modeling, simulation and integration.

Material Protection, Accounting, and Control Technologies (MPACT) Advanced Integration Roadmap

Energy Technology Data Exchange (ETDEWEB)

Miller, Mike [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cipiti, Ben [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Demuth, Scott Francis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Durkee, Jr., Joe W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fallgren, Andrew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jarman, Ken [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Shelly [Idaho National Lab. (INL), Idaho Falls, ID (United States); Meier, Dave [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Osburn, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Dasari, Venkateswara Rao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ticknor, Lawrence O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yoo, Tae-Sic [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-01-30

The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal (Miller, 2015). This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools will consist of instrumentation and devices as well as computer software for modeling, simulation and integration.

Integrated risk reduction framework to improve railway hazardous materials transportation safety

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiang, E-mail: liu94@illinois.edu; Saat, M. Rapik, E-mail: mohdsaat@illinois.edu; Barkan, Christopher P.L., E-mail: cbarkan@illinois.edu

2013-09-15

Highlights: • An integrated framework is developed to optimize risk reduction. • A negative binomial regression model is developed to analyze accident-cause-specific railcar derailment probability. • A Pareto-optimality technique is applied to determine the lowest risk given any level of resource. • A multi-attribute decision model is developed to determine the optimal amount of investment for risk reduction. • The models could aid the government and rail industry in developing cost-efficient risk reduction policy and practice. -- Abstract: Rail transportation plays a critical role to safely and efficiently transport hazardous materials. A number of strategies have been implemented or are being developed to reduce the risk of hazardous materials release from train accidents. Each of these risk reduction strategies has its safety benefit and corresponding implementation cost. However, the cost effectiveness of the integration of different risk reduction strategies is not well understood. Meanwhile, there has been growing interest in the U.S. rail industry and government to best allocate resources for improving hazardous materials transportation safety. This paper presents an optimization model that considers the combination of two types of risk reduction strategies, broken rail prevention and tank car safety design enhancement. A Pareto-optimality technique is used to maximize risk reduction at a given level of investment. The framework presented in this paper can be adapted to address a broader set of risk reduction strategies and is intended to assist decision makers for local, regional and system-wide risk management of rail hazardous materials transportation.

Review on processing of metal-organic framework (MOF) materials towards system integration for hydrogen storage

CSIR Research Space (South Africa)

Ren, Jianwei

2014-09-01

Full Text Available materials to form part of a practical hydrogen storage system, knowledge of the ‘processing’ techniques to improve the properties of the powders is essential. However, the processing routes of MOF materials towards system integration are rarely reviewed...

Can integrative catchment management mitigate future water quality issues caused by climate change and socio-economic development?

Science.gov (United States)

Honti, Mark; Schuwirth, Nele; Rieckermann, Jörg; Stamm, Christian

2017-03-01

The design and evaluation of solutions for integrated surface water quality management requires an integrated modelling approach. Integrated models have to be comprehensive enough to cover the aspects relevant for management decisions, allowing for mapping of larger-scale processes such as climate change to the regional and local contexts. Besides this, models have to be sufficiently simple and fast to apply proper methods of uncertainty analysis, covering model structure deficits and error propagation through the chain of sub-models. Here, we present a new integrated catchment model satisfying both conditions. The conceptual iWaQa model was developed to support the integrated management of small streams. It can be used to predict traditional water quality parameters, such as nutrients and a wide set of organic micropollutants (plant and material protection products), by considering all major pollutant pathways in urban and agricultural environments. Due to its simplicity, the model allows for a full, propagative analysis of predictive uncertainty, including certain structural and input errors. The usefulness of the model is demonstrated by predicting future surface water quality in a small catchment with mixed land use in the Swiss Plateau. We consider climate change, population growth or decline, socio-economic development, and the implementation of management strategies to tackle urban and agricultural point and non-point sources of pollution. Our results indicate that input and model structure uncertainties are the most influential factors for certain water quality parameters. In these cases model uncertainty is already high for present conditions. Nevertheless, accounting for today's uncertainty makes management fairly robust to the foreseen range of potential changes in the next decades. The assessment of total predictive uncertainty allows for selecting management strategies that show small sensitivity to poorly known boundary conditions. The identification

Portable Thermoelectric Power Generator Coupled with Phase Change Material

OpenAIRE

Lim Chong C.; Al-Kayiem Hussain H.; Sing Chin Y.

2014-01-01

Solar is the intermittent source of renewable energy and all thermal solar systems having a setback on non-functioning during the night and cloudy environment. This paper presents alternative solution for power generation using thermoelectric which is the direct conversion of temperature gradient of hot side and cold side of thermoelectric material to electric voltage. Phase change material with latent heat effect would help to prolong the temperature gradient across thermoelectric material f...

Integration of Geometrical and Material Nonlinear Energy Sink with Piezoelectric Material Energy Harvester

Directory of Open Access Journals (Sweden)

Ye-Wei Zhang

2017-01-01

Full Text Available This paper presents a novel design by integrating geometrical and material nonlinear energy sink (NES with a piezoelectric-based vibration energy harvester under shock excitation, which can realize vibration control and energy harvesting. The nonlinear spring and hysteresis behavior of the NES could reflect geometrical and material nonlinearity, respectively. Two configurations of the piezoelectric device, including the piezoelectric element embedded between the NES mass and the single-degree-of-freedom system or ground, are utilised to examine the energy dissipated by damper and hysteresis behavior of NES and the energy harvested by the piezoelectric element. Similar numerical research methods of Runge-Kutta algorithm are used to investigate the two configurations. The energy transaction measure (ETM is adopted to examine the instantaneous energy transaction between the primary and the NES-piezoelectricity system. And it demonstrates that the dissipated and harvested energy transaction is transferred from the primary system to the NES-piezoelectricity system and the instantaneous transaction of mechanical energy occupies a major part of the energy of transaction. Both figurations could realize vibration control efficiently.

Integrated micro/nanoengineered functional biomaterials for cell mechanics and mechanobiology: a materials perspective.

Science.gov (United States)

Shao, Yue; Fu, Jianping

2014-03-12

The rapid development of micro/nanoengineered functional biomaterials in the last two decades has empowered materials scientists and bioengineers to precisely control different aspects of the in vitro cell microenvironment. Following a philosophy of reductionism, many studies using synthetic functional biomaterials have revealed instructive roles of individual extracellular biophysical and biochemical cues in regulating cellular behaviors. Development of integrated micro/nanoengineered functional biomaterials to study complex and emergent biological phenomena has also thrived rapidly in recent years, revealing adaptive and integrated cellular behaviors closely relevant to human physiological and pathological conditions. Working at the interface between materials science and engineering, biology, and medicine, we are now at the beginning of a great exploration using micro/nanoengineered functional biomaterials for both fundamental biology study and clinical and biomedical applications such as regenerative medicine and drug screening. In this review, an overview of state of the art micro/nanoengineered functional biomaterials that can control precisely individual aspects of cell-microenvironment interactions is presented and they are highlighted them as well-controlled platforms for mechanistic studies of mechano-sensitive and -responsive cellular behaviors and integrative biology research. The recent exciting trend where micro/nanoengineered biomaterials are integrated into miniaturized biological and biomimetic systems for dynamic multiparametric microenvironmental control of emergent and integrated cellular behaviors is also discussed. The impact of integrated micro/nanoengineered functional biomaterials for future in vitro studies of regenerative medicine, cell biology, as well as human development and disease models are discussed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of Contextual Mathematics teaching Material integrated related sciences and realistic for students grade xi senior high school

Science.gov (United States)

Helma, H.; Mirna, M.; Edizon, E.

2018-04-01

Mathematics is often applied in physics, chemistry, economics, engineering, and others. Besides that, mathematics is also used in everyday life. Learning mathematics in school should be associated with other sciences and everyday life. In this way, the learning of mathematics is more realstic, interesting, and meaningful. Needs analysis shows that required contextual mathematics teaching materials integrated related sciences and realistic on learning mathematics. The purpose of research is to produce a valid and practical contextual mathematics teaching material integrated related sciences and realistic. This research is development research. The result of this research is a valid and practical contextual mathematics teaching material integrated related sciences and realistic produced

Long term integrity of spent fuel and construction materials for dry storage facilities

Energy Technology Data Exchange (ETDEWEB)

Saegusa, T [CRIEPI (Japan)

2012-07-01

In Japan, two dry storage facilities at reactor sites have already been operating since 1995 and 2002, respectively. Additionally, a large scale dry storage facility away from reactor sites is under safety examination for license near the coast and desired to start its operation in 2010. Its final storage capacity is 5,000tU. It is therefore necessary to obtain and evaluate the related data on integrity of spent fuels loaded into and construction materials of casks during long term dry storage. The objectives are: - Spent fuel rod: To evaluate hydrogen migration along axial fuel direction on irradiated claddings stored for twenty years in air; To evaluate pellet oxidation behaviour for high burn-up UO{sub 2} fuels; - Construction materials for dry storage facilities: To evaluate long term reliability of welded stainless steel canister under stress corrosion cracking (SCC) environment; To evaluate long term integrity of concrete cask under carbonation and salt attack environment; To evaluate integrity of sealability of metal gasket under long term storage and short term accidental impact force.

Climate change and foreign policy : an exploration of options for greater integration

International Nuclear Information System (INIS)

Drexhage, J.; Murphy, D.; Brown, O.; Cosbey, A.; Dickey, P.; Parry, J.-E.; Van Ham, J.; Tarasofsky, R.; Darkin, B.

2007-01-01

Climate change is a global challenge and one of biggest challenges of this century. Addressing the challenges posed by climate change requires new thinking in foreign policy. This paper discussed the results of a research study that examined the role of foreign policy in fostering a more effective international response to the challenge of climate change. The scope involved an examination of instruments relevant to Danish foreign policy. The paper first identified the climate change challenge and discussed international diplomacy and relations. Energy security and investment was discussed in terms of the impact of energy security on climate change efforts and opportunities for integration. Other areas where critical issues and opportunities for integration were offered include international peace and security; trade and investment; and development cooperation. The paper made several recommendations in these areas in addition to diplomatic networking. The study concluded that foreign policy can further the climate change agenda in a number of areas in diplomacy and foreign relations within the European Union, transatlantic relations, Arctic issues and United Nations affairs. This includes better integration of climate change into the European Union's common foreign and security policy, the Lisbon Agenda, and incorporating climate change in the work of a wide range of bodies under the United Nations. refs., figs

The changing role of nuclear materials accounting

International Nuclear Information System (INIS)

Gibbs, P.W.

1995-01-01

Nuclear materials accounting and accounting systems at what have been DOE Production sites are evolving into management decision support tools. As the sites are moving into the mode of making decisions on how to disposition complex and varied nuclear material holdings, the need for complete and many times different information has never been greater. The artificial boundaries that have historically been established between what belongs in the classic material control and accountability (MC and A) records versus what goes into the financial, radiological control, waste, or decommissioning and decontamination records are being challenged. In addition, the tools historically used to put material into different categories such as scrap codes, composition codes, etc. have been found to be inadequate for the information needs of today. In order to be cost effective and even, more importantly to effectively manage -our inventories, the new information systems the authors design have to have the flexibility to serve many needs. In addition, those tasked with the responsibility of managing the inventories must also expand beyond the same artificial boundaries. This paper addresses some of the things occurring at the Savannah River Site to support the changing role of nuclear materials accounting

Structural integrity of frontostriatal connections predicts longitudinal changes in self-esteem.

Science.gov (United States)

Chavez, Robert S; Heatherton, Todd F

2017-06-01

Diverse neurological and psychiatric conditions are marked by a diminished sense of positive self-regard, and reductions in self-esteem are associated with risk for these disorders. Recent evidence has shown that the connectivity of frontostriatal circuitry reflects individual differences in self-esteem. However, it remains an open question as to whether the integrity of these connections can predict self-esteem changes over larger timescales. Using diffusion magnetic resonance imaging and probabilistic tractography, we demonstrate that the integrity of white matter pathways linking the medial prefrontal cortex to the ventral striatum predicts changes in self-esteem 8 months after initial scanning in a sample of 30 young adults. Individuals with greater integrity of this pathway during the scanning session at Time 1 showed increased levels of self-esteem at follow-up, whereas individuals with lower integrity showed stifled or decreased levels of self-esteem. These results provide evidence that frontostriatal white matter integrity predicts the trajectory of self-esteem development in early adulthood, which may contribute to blunted levels of positive self-regard seen in multiple psychiatric conditions, including depression and anxiety.

Organic Phase Change Materials And Their Textile Applications: An Overview

OpenAIRE

Sarıer, Nihal; Önder, Emel

2012-01-01

An organic phase change material (PCM) possesses the ability to absorb and release large quantity of latent heat during a phase change process over a certain temperature range. The use of PCMs in energy storage and thermal insulation has been tested scientifically and industrially in many applications. The broad based research and development studies concentrating on the characteristics of known organic PCMs and new materials as PCM candidates, the storage methods of PCMs, as well as the reso...

A review of phase change materials for vehicle component thermal buffering

International Nuclear Information System (INIS)

Jankowski, Nicholas R.; McCluskey, F. Patrick

2014-01-01

Highlights: • A review of latent heat thermal energy storage for vehicle thermal load leveling. • Examined vehicle applications with transient thermal profiles from 0 to 800 °C. • >700 materials from over a dozen material classes examined for the applications. • Recommendations made for future application of high power density materials. - Abstract: The use of latent heat thermal energy storage for thermally buffering vehicle systems is reviewed. Vehicle systems with transient thermal profiles are classified according to operating temperatures in the range of 0–800 °C. Thermal conditions of those applications are examined relative to their impact on thermal buffer requirements, and prior phase change thermal enhancement studies for these applications are discussed. In addition a comprehensive overview of phase change materials covering the relevant operating range is given, including selection criteria and a detailed list of over 700 candidate materials from a number of material classes. Promising material candidates are identified for each vehicle system based on system temperature, specific and volumetric latent heat, and thermal conductivity. Based on the results of previous thermal load leveling efforts, there is the potential for making significant improvements in both emissions reduction and overall energy efficiency by further exploration of PCM thermal buffering on vehicles. Recommendations are made for further material characterization, with focus on the need for improved data for metallic and solid-state phase change materials for high energy density applications

Replacement of Ablators with Phase-Change Material for Thermal Protection of STS Elements

Science.gov (United States)

Kaul, Raj K.; Stuckey, Irvin; Munafo, Paul M. (Technical Monitor)

2002-01-01

As part of the research and development program to develop new Thermal Protection System (TPS) materials for aerospace applications at NASA's Marshall Space Flight Center (MSFC), an experimental study was conducted on a new concept for a non-ablative TPS material. Potential loss of TPS material and ablation by-products from the External Tank (ET) or Solid Rocket Booster (SRB) during Shuttle flight with the related Orbiter tile damage necessitates development of a non-ablative thermal protection system. The new Thermal Management Coating (TMC) consists of phase-change material encapsulated in micro spheres and a two-part resin system to adhere the coating to the structure material. The TMC uses a phase-change material to dissipate the heat produced during supersonic flight rather than an ablative material. This new material absorbs energy as it goes through a phase change during the heating portion of the flight profile and then the energy is slowly released as the phase-change material cools and returns to its solid state inside the micro spheres. The coating was subjected to different test conditions simulating design flight environments at the NASA/MSFC Improved Hot Gas Facility (IHGF) to study its performance.

Corporate Disclosure, Materiality, and Integrated Report: An Event Study Analysis

OpenAIRE

Maria Cleofe Giorgino; Enrico Supino; Federico Barnabè

2017-01-01

Within the extensive literature investigating the impacts of corporate disclosure in supporting the sustainable growth of an organization, few studies have included in the analysis the materiality issue referred to the information being disclosed. This article aims to address this gap, exploring the effect produced on capital markets by the publication of a recent corporate reporting tool, Integrated Report (IR). The features of this tool are that it aims to represent the multidimensional imp...

Two-Dimensional Metal-Free Organic Multiferroic Material for Design of Multifunctional Integrated Circuits.

Science.gov (United States)

Tu, Zhengyuan; Wu, Menghao; Zeng, Xiao Cheng

2017-05-04

Coexistence of ferromagnetism and ferroelectricity in a single 2D material is highly desirable for integration of multifunctional units in 2D material-based circuits. We report theoretical evidence of C 6 N 8 H organic network as being the first 2D organic multiferroic material with coexisting ferromagnetic and ferroelectric properties. The ferroelectricity stems from multimode proton-transfer within the 2D C 6 N 8 H network, in which a long-range proton-transfer mode is enabled by the facilitation of oxygen molecule when the network is exposed to the air. Such oxygen-assisted ferroelectricity also leads to a high Curie temperature and coupling between ferroelectricity and ferromagnetism. We also find that hydrogenation and carbon doping can transform the 2D g-C 3 N 4 network from an insulator to an n-type/p-type magnetic semiconductor with modest bandgap. Akin to the dopant induced n/p channels in silicon wafer, a variety of dopant created functional units can be integrated into the g-C 3 N 4 wafer by design for nanoelectronic applications.

Characterization of a lime-pozzolan plaster containing phase change material

International Nuclear Information System (INIS)

Pavlíková, Milena; Pavlík, Zbyšek; Trník, Anton; Pokorný, Jaroslav; Černý, Robert

2015-01-01

A PCM (Phase Change Material) modified lime-pozzolan plaster for improvement of thermal energy storage of building envelopes is studied in the paper. The investigated plaster is composed of lime hydrate, pozzolan admixture based on metakaolin and mudstone, silica sand, water and paraffin wax encapsulated in polymer capsule. The reference plaster without PCM application is studied as well. The analyzed materials are characterized by bulk density, matrix density, total open porosity, compressive strength and pore size distribution. The temperature of phase change, heat of fusion and crystallization are studied using DSC (Difference Scanning Calorimetry) analysis performed in air atmosphere. In order to get information on materials hygrothermal performance, determination of thermal and hygric properties is done in laboratory conditions. Experimental data reveal a substantial improvement of heat storage capacity of PCM-modified plaster as compared to the reference material without PCM

Phase Change Materials in Transparent Building Envelopes: A Strengths, Weakness, Opportunities and Threats (SWOT Analysis

Directory of Open Access Journals (Sweden)

Ilaria Vigna

2018-01-01

Full Text Available Building envelopes can play a crucial role in building improvement efficiency, and the adoption of Phase Change Materials (PCMs, coupled with transparent elements, may: (i allow a better control of the heat flows from/to the outdoor environment, (ii increase the exploitation of solar energy at a building scale and (iii modulate light transmission in order to prevent glare effects. Starting from a literature review, focused on experimental works, this research identifies the main possible integrations of PCMs in transparent/translucent building envelope components (in glazing, in shutters and in multilayer façade system in order to draw a global picture of the potential and limitations of these technologies. Transparent envelopes with PCMs have been classified from the simplest “zero” technology, which integrates the PCM in a double glass unit (DGU, to more complex solutions—with a different number of glass cavities (triple glazed unit TGU, different positions of the PCM layer (internal/external shutter, and in combination with other materials (TIM, aerogel, prismatic solar reflector, PCM curtain controlled by an electric pump. The results of the analysis have been summarised in a Strengths, Weakness, Opportunities and Threats (SWOT analysis table to underline the strengths and weaknesses of transparent building envelope components with PCMs, and to indicate opportunities and threats for future research and building applications.

The role of organizational structure in readiness for change: A conceptual integration.

Science.gov (United States)

Benzer, Justin K; Charns, Martin P; Hamdan, Sami; Afable, Melissa

2017-02-01

The purpose of this review is to extend extant conceptualizations of readiness for change as an individual-level phenomenon. This review-of-reviews focuses on existing conceptual frameworks from the dissemination, implementation, quality improvement, and organizational transformation literatures in order to integrate theoretical rationales for how organization structure, a key dimension of the organizational context, may impact readiness for change. We propose that the organization structure dimensions of differentiation and integration impact readiness for change at the individual level of analysis by influencing four key concepts of relevance, legitimacy, perceived need for change, and resource allocation. We identify future research directions that focus on these four key concepts.

Integrating uncertainties for climate change mitigation

Science.gov (United States)

Rogelj, Joeri; McCollum, David; Reisinger, Andy; Meinshausen, Malte; Riahi, Keywan

2013-04-01

The target of keeping global average temperature increase to below 2°C has emerged in the international climate debate more than a decade ago. In response, the scientific community has tried to estimate the costs of reaching such a target through modelling and scenario analysis. Producing such estimates remains a challenge, particularly because of relatively well-known, but ill-quantified uncertainties, and owing to limited integration of scientific knowledge across disciplines. The integrated assessment community, on one side, has extensively assessed the influence of technological and socio-economic uncertainties on low-carbon scenarios and associated costs. The climate modelling community, on the other side, has worked on achieving an increasingly better understanding of the geophysical response of the Earth system to emissions of greenhouse gases (GHG). This geophysical response remains a key uncertainty for the cost of mitigation scenarios but has only been integrated with assessments of other uncertainties in a rudimentary manner, i.e., for equilibrium conditions. To bridge this gap between the two research communities, we generate distributions of the costs associated with limiting transient global temperature increase to below specific temperature limits, taking into account uncertainties in multiple dimensions: geophysical, technological, social and political. In other words, uncertainties resulting from our incomplete knowledge about how the climate system precisely reacts to GHG emissions (geophysical uncertainties), about how society will develop (social uncertainties and choices), which technologies will be available (technological uncertainty and choices), when we choose to start acting globally on climate change (political choices), and how much money we are or are not willing to spend to achieve climate change mitigation. We find that political choices that delay mitigation have the largest effect on the cost-risk distribution, followed by

Challenges in Incorporating Climate Change Adaptation into Integrated Water Resources Management

Science.gov (United States)

Kirshen, P. H.; Cardwell, H.; Kartez, J.; Merrill, S.

2011-12-01

Over the last few decades, integrated water resources management (IWRM), under various names, has become the accepted philosophy for water management in the USA. While much is still to be learned about how to actually carry it out, implementation is slowly moving forward - spurred by both legislation and the demands of stakeholders. New challenges to IWRM have arisen because of climate change. Climate change has placed increased demands on the creativities of planners and engineers because they now must design systems that will function over decades of hydrologic uncertainties that dwarf any previous hydrologic or other uncertainties. Climate and socio-economic monitoring systems must also now be established to determine when the future climate has changed sufficiently to warrant undertaking adaptation. The requirements for taking some actions now and preserving options for future actions as well as the increased risk of social inequities in climate change impacts and adaptation are challenging experts in stakeholder participation. To meet these challenges, an integrated methodology is essential that builds upon scenario analysis, risk assessment, statistical decision theory, participatory planning, and consensus building. This integration will create cross-disciplinary boundaries for these disciplines to overcome.

Subscale Water Based Phase Change Material Heat Exchanger Development

Science.gov (United States)

Sheth, Rubik; Hansen, Scott

2016-01-01

Supplemental heat rejection devices are required in many spacecraft as the radiators are not sized to meet the full heat rejection demand. One means of obtaining additional heat rejection is through the use of phase change material heat exchangers (PCM HX's). PCM HX's utilize phase change to store energy in unfavorable thermal environments (melting) and reject the energy in favorable environments (freezing). Traditionally, wax has been used as a PCM on spacecraft. However, water is an attractive alternative because it is capable of storing about 40% more energy per unit mass due to its higher latent heat of fusion. The significant problem in using water as a PCM is its expansion while freezing, leading to structural integrity concerns when housed in an enclosed heat exchanger volume. Significant investigation and development has taken place over the past five years to understand and overcome the problems associated with water PCM HX's. This paper reports on the final efforts by Johnson Space Center's Thermal Systems Branch to develop a water based PCM HX. The test article developed and reported on is a subscale version of the full-scale water-based PCM HX's constructed by Mezzo Technologies. The subscale unit was designed by applying prior research on freeze front propagation and previous full-scale water PCM HX development. Design modifications to the subscale unit included use of urethane bladder, decreased aspect ratio, perforated protection sheet, and use of additional mid-plates. Testing of the subscale unit was successful and 150 cycles were completed without fail.

Phase Change Material Based Accumulation Panels in Combination with Renewable Energy Sources and Thermoelectric Cooling

Directory of Open Access Journals (Sweden)

Jan Skovajsa

2017-01-01

Full Text Available The article deals with the use of modern materials and technologies that can improve the thermal comfort in buildings. The article describes the design and usage of a special accumulation device, which is composed of thermal panels based on phase change materials (PCMs. The thermal panels have an integrated tube heat exchanger and heating foils. The technology can be used as a passive or active system for heating and cooling. It is designed as a “green technology”, so it is able to use renewable energy sources, e.g., photovoltaic (PV panels, solar thermal collectors and heat pumps. Moreover, an interesting possibility is the ability to use thermoelectric coolers. In the research, measurements of the different operating modes were made, and the results are presented in the text. The measurement approves that the technology improves the thermal capacity of the building, and it is possible to use it for active heating and cooling.

Thermal performance study of form-stable composite phase change material with polyacrylic

Science.gov (United States)

Kee, Shin Yiing; Munusamy, Yamuna; Ong, Kok Seng; Chee, Swee Yong; Sanmuggam, Shimalaa

2017-04-01

Phase change material (PCM) is one of the most popular and widely used as thermal energy storage material because it is able to absorb and release a large amount of latent heat during a phase change process over a narrow temperature range. In this work, the form-stable composite PCM was prepared by blending of PMMA and myristic acid in different weight percentage. PMMA was used as a supporting material while myristic acid was used as PCM. Theoretically, PCM can be encapsulated in the support material after blending. However, a small amount of liquid PCMs can leak out from supporting material due to the volume change in phase change process. Therefore, a form-stable composite PCM with polyacrylic coating was studied. Leakage test was carried out to determine the leakage percentage of the form-stable composite PCM. Fourier transform infrared spectroscopy (FTIR) was used to characterize the chemical compatibility of the form-stable PCM composite while differential scanning calorimetry (DSC) was used to study the melting, freezing point and the latent heat of melting and freezing for the form-stable composite PCM.

Development of phase change materials based microencapsulated technology for buildings: A review

Energy Technology Data Exchange (ETDEWEB)

Tyagi, V.V.; Kaushik, S.C. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India); Tyagi, S.K. [School of Infrastructure Technology and Resource Management, Shri Mata Vaishno Devi University, Katra 182320, J and K (India); Akiyama, T. [Center for Advanced Research of Energy Conversion Materials, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo 060-86283 (Japan)

2011-02-15

Thermal energy storage (TES) systems using phase change material (PCM) have been recognized as one of the most advanced energy technologies in enhancing the energy efficiency and sustainability of buildings. Now the research is focus on suitable method to incorporate PCMs with building. There are several methods to use phase change materials (PCMs) in thermal energy storage (TES) for different applications. Microencapsulation is one of the well known and advanced technologies for better utilization of PCMs with building parts, such as, wall, roof and floor besides, within the building materials. Phase change materials based microencapsulation for latent heat thermal storage (LHTS) systems for building application offers a challenging option to be employed as effective thermal energy storage and a retrieval device. Since the particular interest in using microencapsulation PCMs for concrete and wall/wallboards, the specific research efforts on both subjects are reviewed separately. This paper presents an overview of the previous research work on microencapsulation technology for thermal energy storage incorporating the phase change materials (PCMs) in the building applications, along with few useful conclusive remarks concluded from the available literature. (author)

Fundamental incorporation of the density change during melting of a confined phase change material

Science.gov (United States)

Hernández, Ernesto M.; Otero, José A.

2018-02-01

The modeling of thermal diffusion processes taking place in a phase change material presents a challenge when the dynamics of the phase transition is coupled to the mechanical properties of the container. Thermo-mechanical models have been developed by several authors, however, it will be shown that these models only explain the phase transition dynamics at low pressures when the density of each phase experiences negligible changes. In our proposal, a new energy-mass balance equation at the interface is derived and found to be a consequence of mass conservation. The density change experienced in each phase is predicted by the proposed formulation of the problem. Numerical and semi-analytical solutions to the proposed model are presented for an example on a high temperature phase change material. The solutions to the models presented by other authors are observed to be well-behaved close to the isobaric limit. However, compared to the results obtained from our model, the change in the fusion temperature, latent heat, and absolute pressure is found to be greatly overestimated by other proposals when the phase transition is studied close to the isochoric regime.

High Temperature Integrated Thermoelectric Ststem and Materials

Energy Technology Data Exchange (ETDEWEB)

Mike S. H. Chu

2011-06-06

The final goal of this project is to produce, by the end of Phase II, an all ceramic high temperature thermoelectric module. Such a module design integrates oxide ceramic n-type, oxide ceramic p-type materials as thermoelectric legs and oxide ceramic conductive material as metalizing connection between n-type and p-type legs. The benefits of this all ceramic module are that it can function at higher temperatures (> 700 C), it is mechanically and functionally more reliable and it can be scaled up to production at lower cost. With this all ceramic module, millions of dollars in savings or in new opportunities recovering waste heat from high temperature processes could be made available. A very attractive application will be to convert exhaust heat from a vehicle to reusable electric energy by a thermoelectric generator (TEG). Phase I activities were focused on evaluating potential n-type and p-type oxide compositions as the thermoelectric legs. More than 40 oxide ceramic powder compositions were made and studied in the laboratory. The compositions were divided into 6 groups representing different material systems. Basic ceramic properties and thermoelectric properties of discs sintered from these powders were measured. Powders with different particles sizes were made to evaluate the effects of particle size reduction on thermoelectric properties. Several powders were submitted to a leading thermoelectric company for complete thermoelectric evaluation. Initial evaluation showed that when samples were sintered by conventional method, they had reasonable values of Seebeck coefficient but very low values of electrical conductivity. Therefore, their power factors (PF) and figure of merits (ZT) were too low to be useful for high temperature thermoelectric applications. An unconventional sintering method, Spark Plasma Sintering (SPS) was determined to produce better thermoelectric properties. Particle size reduction of powders also was found to have some positive benefits

Dimensional changes of alginate dental impression materials.

Science.gov (United States)

Nallamuthu, N; Braden, M; Patel, M P

2006-12-01

The weight loss and corresponding dimensional changes of two dental alginate impression materials have been studied. The weight loss kinetics indicate this to be a diffusion controlled process, but with a boundary condition at the surface of the concentration decreasing exponentially with time. This is in marked contrast to most desorption processes, where the surface concentration becomes instantaneously zero. The appropriate theory has been developed for an exponential boundary condition, and its predictions compared with experimental data; the agreement was satisfactory. The diffusion coefficients for two thicknesses of the same material were not identical as predicted by theory; the possible reasons for this are discussed.

Experimental Studies of Phase Change and Microencapsulated Phase Change Materials in a Cold Storage/Transportation System with Solar Driven Cooling Cycle

OpenAIRE

Lin Zheng; Wei Zhang; Fei Liang; Shuang Lin; Xiangyu Jin

2017-01-01

The paper presents the different properties of phase change material (PCM) and Microencapsulated phase change material (MEPCM) employed to cold storage/transportation system with a solar-driven cooling cycle. Differential Scanning Calorimeter (DSC) tests have been performed to analyze the materials enthalpy, melting temperature range, and temperature range of solidification. KD2 Pro is used to test the thermal conductivities of phase change materials slurry and the results were used to compar...

Nano-pulsed laser irradiation scanning system for phase-change materials

International Nuclear Information System (INIS)

Kim, Sookyung; Li Xuezhe; Lee, Sangbin; Kim, Kyung-Ho; Lee, Seung-Yop

2008-01-01

Recently, the demand of a laser irradiation tester is increasing for phase change random access memory (PRAM) as well as conventional optical storage media. In this study, a nano-pulsed laser irradiation system is developed to characterize the optical property and writing performance of phase-change materials, based on a commercially available digital versatile disk (DVD) optical pick-up. The precisely controlled focusing and scanning on the material's surface are implemented using the auto-focusing mechanism and a voice coil motor (VCM) of the commercial DVD pick-up. The laser irradiation system provides various writing and reading functions such as adjustable laser power, pulse duration, recording pattern (spot, line and area), and writing/reading repetition, phase transition, and in situ reflectivity measurement before/after irradiation. Measurements of power time effect (PTE) diagram and reflectivity map of Ge 2 Sb 2 Te 5 samples show that the proposed laser irradiation system provides the powerful scanning tool to quantify the optical characteristics of phase-change materials

United States Department of Energy Nuclear Materials Stewardship

International Nuclear Information System (INIS)

Newton, J. W.

2002-01-01

The Department of Energy launched the Nuclear Materials Stewardship Initiative in January 2000 to accelerate the work of achieving integration and cutting long-term costs associated with the management of the Department's nuclear materials, with the principal focus on excess materials. Management of nuclear materials is a fundamental and enduring responsibility that is essential to meeting the Department's national security, nonproliferation, energy, science, and environmental missions into the distant future. The effective management of nuclear materials is important for a set of reasons: (1) some materials are vital to our national defense; (2) the materials pose physical and security risks; (3) managing them is costly; and (4) costs are likely to extend well into the future. The Department currently manages nuclear materials under eight programs, with offices in 36 different locations. Through the Nuclear Materials Stewardship Initiative, progress was during calendar year 20 00 in achieving better coordination and integration of nuclear materials management responsibilities and in evaluating opportunities to further coordinate and integrate cross-program responsibilities for the treatment, storage, and disposition of excess nuclear materials. During CY 2001 the Departmental approach to nuclear materials stewardship changed consistent with the business processes followed by the new administration. This paper reports on the progress of the Nuclear Materials Stewardship Initiative in evaluating and implementing these opportunities, and the remaining challenges in integrating the long-term management of nuclear materials

Effects of planar element formulation and numerical integration order on checkerboard material layouts

CSIR Research Space (South Africa)

Long, CS

2009-01-01

Full Text Available The effects of selected planar finite element formulations, and their associated integration schemes, on the stiffness of a checkerboard material layout are investigated. Standard 4-node bilinear elements, 8- and 9-node quadratic elements, as well...

Integrated Theory of Health Behavior Change: background and intervention development.

Science.gov (United States)

Ryan, Polly

2009-01-01

An essential characteristic of advanced practice nurses is the use of theory in practice. Clinical nurse specialists apply theory in providing or directing patient care, in their work as consultants to staff nurses, and as leaders influencing and facilitating system change. Knowledge of technology and pharmacology has far outpaced knowledge of how to facilitate health behavior change, and new theories are needed to better understand how practitioners can facilitate health behavior change. In this article, the Integrated Theory of Health Behavior Change is described, and an example of its use as foundation to intervention development is presented. The Integrated Theory of Health Behavior Change suggests that health behavior change can be enhanced by fostering knowledge and beliefs, increasing self-regulation skills and abilities, and enhancing social facilitation. Engagement in self-management behaviors is seen as the proximal outcome influencing the long-term distal outcome of improved health status. Person-centered interventions are directed to increasing knowledge and beliefs, self-regulation skills and abilities, and social facilitation. Using a theoretical framework improves clinical nurse specialist practice by focusing assessments, directing the use of best-practice interventions, and improving patient outcomes. Using theory fosters improved communication with other disciplines and enhances the management of complex clinical conditions by providing holistic, comprehensive care.

Integral activation experiment of fusion reactor materials with d-Li neutrons up to 55 MeV

Energy Technology Data Exchange (ETDEWEB)

Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Moellendorff, Ulrich von [Forschungszentrum Karlsruhe, Karlsruhe (Germany); Wada, Masayuki [Business Automation Co., Ltd., Tokyo (Japan)

2000-03-01

An integral activation experiment of fusion reactor materials with a deuteron-lithium neutron source was performed. Since the maximum energy of neutrons produced was 55 MeV, the experiment with associated analysis was one of the first attempts for extending the energy range beyond 20 MeV. The following keywords represent the present study: d-Li neutrons, 55 MeV, dosimetry, SAND-II, spectrum adjustment, LA-150, MCNP, McDeLi, IFMIF, fusion reactor materials, integral activation experiment, low-activation, F82H, vanadium-alloy, IEAF, ALARA, and sequential charged particle reaction. (author)

Integrating global socio-economic influences into a regional land use change model for China

Science.gov (United States)

Xu, Xia; Gao, Qiong; Peng, Changhui; Cui, Xuefeng; Liu, Yinghui; Jiang, Li

2014-03-01

With rapid economic development and urbanization, land use in China has experienced huge changes in recent years; and this will probably continue in the future. Land use problems in China are urgent and need further study. Rapid land-use change and economic development make China an ideal region for integrated land use change studies, particularly the examination of multiple factors and global-regional interactions in the context of global economic integration. This paper presents an integrated modeling approach to examine the impact of global socio-economic processes on land use changes at a regional scale. We develop an integrated model system by coupling a simple global socio-economic model (GLOBFOOD) and regional spatial allocation model (CLUE). The model system is illustrated with an application to land use in China. For a given climate change, population growth, and various socio-economic situations, a global socio-economic model simulates the impact of global market and economy on land use, and quantifies changes of different land use types. The land use spatial distribution model decides the type of land use most appropriate in each spatial grid by employing a weighted suitability index, derived from expert knowledge about the ecosystem state and site conditions. A series of model simulations will be conducted and analyzed to demonstrate the ability of the integrated model to link global socioeconomic factors with regional land use changes in China. The results allow an exploration of the future dynamics of land use and landscapes in China.

Integrating global energy and climate governance: The changing role of the International Energy Agency

International Nuclear Information System (INIS)

Heubaum, Harald; Biermann, Frank

2015-01-01

Despite the long-recognized interlinkages between global energy consumption and climate change, there has historically been only limited policy interaction, let alone integration, between the two fields. This compartmentalization is mirrored in scholarship, where much research has focused on the fragmentation of, respectively, global energy and global climate governance, but only little has been said about how these fields might be integrated. Our analysis of the International Energy Agency’s (IEA) changing activities in recent years shows that governance integration – both within global energy governance and between global energy and climate governance – is now happening. The IEA has broadened its portfolio to embrace the full spectrum of energy issues, including renewable energy and climate change; it has built and is expanding key partnerships with both the UN climate convention and the International Renewable Energy Agency (IRENA); and it has become an authoritative advocate for the inter-related goals of a low-carbon transition and climate change mitigation. We show that these developments are not the result of a top-down plan, but have rather emerged through the Agency’s various efforts to pursue its energy-centric mandate in a fast-changing global policy environment. - Highlights: • Assesses integration between global energy and global climate governance. • Analyzes organizational change in the IEA and its impact on governance integration. • Discusses recent activities and advocacy by the IEA in relation to climate change.

Structural integrity for DEMO: An opportunity to close the gap from materials science to engineering needs

Energy Technology Data Exchange (ETDEWEB)

Porton, M., E-mail: michael.porton@ccfe.ac.uk [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Wynne, B.P. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); University of Sheffield, Sheffield, South Yorkshire S10 2TN (United Kingdom); Bamber, R.; Hardie, C.D.; Kalsey, M. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

2016-11-01

Highlights: • Key shortfalls in the current approaches to verification of structural integrity are outlined. • Case studies for high integrity applications in other demanding environments are examined. • Relevant lessons are drawn from fission and space for the design stage and through service life. • Future efforts are suggested to align materials and engineering for DEMO structural integrity. - Abstract: It is clear that fusion demonstration devices offer unique challenges due to the myriad, interacting material degradation effects and the numerous, conflicting requirements that must be addressed in order for in-vessel components to deliver satisfactory performance over the required lifetime. The link between mechanical engineering and materials science is pivotal to assure the timely realisation and exploitation of successful fusion power. A key aspect of this link is the verification of structural integrity, achieved at the design stage via structural design criteria against which designs are judged to be sufficiently resilient (or not) to failure, for a given set of loading conditions and desired lifetime. As various demonstration power plant designs progress through their current conceptual design phases, this paper seeks to highlight key shortfalls in this vital link between engineering needs and materials science, offering a perspective on where future attention can be prioritised to maximise impact. Firstly, issues in applying existing structural design criteria to demonstration power plant designs are identified. Whilst fusion offers particular challenges, there are significant insights to be gained from attempts to address such issues for high performance, high integrity applications in other demanding environments. Therefore case studies from beyond fusion are discussed. These offer examples where similar shortfalls have been successfully addressed, via approaches at the design stage and through service lifetime in order to deliver significant

Study of Material Compatibility for a Thermal Energy Storage System with Phase Change Material

Directory of Open Access Journals (Sweden)

Songgang Qiu

2018-03-01

Full Text Available The suitability of stainless steel 316L and Inconel 625 for use in a latent heat thermal energy storage (TES system was investigated. A NaCl–NaF eutectic mixture with a melting temperature of 680 °C was used as the phase change material (PCM. Containers were filled with the PCM prior to heating to 750 °C, then examined after 100 and 2500 h of high-temperature exposure by analyzing the material surface and cross-section areas. A small amount of corrosion was present in both samples after 100 h. Neither sample suffered significant damage after 2500 h. The undesirable inter-granular grain boundary attack found in SS316L samples was in the order of 1–2 µm in depth. On Inconel 625 sample surface, an oxide complex formed, resisting material dissolution into the PCM. The surface morphology of tested samples remained largely unchanged after 2500 h, but the corrosion pattern changed from an initially localized corrosion penetration to a more uniform type. After 2500 h, the corrosion depth of Inconel 625 remained at roughly 1–2 µm, indicating that the corrosion rate decelerated. Both materials demonstrated good compatibility with the chosen NaF–NaCl eutectic salt, but the low corrosion activity in Inconel 625 samples shows a performance advantage for long term operation.

Dry powder mixes comprising phase change materials

Science.gov (United States)

Salyer, I.O.

1994-02-01

Free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a PCM material. The silica-PCM mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub. 2 figures.

Design of a 4D Printing System Using Thermal Sensitive Smart Materials and Photoactivated Shape Changing Polymers

Science.gov (United States)

Leist, Steven Kyle

4D printing is an emerging additive manufacturing technology that combines 3D printing with smart materials. Current 3D printing technology can print objects with a multitude of materials; however, these objects are usually static, geometrically permanent, and not suitable for multi-functional use. The 4D printed objects can change their shape over time when exposed to different external stimuli such as heat, pressure, magnetic fields, or moisture. In this research, heat and light reactive smart materials are explored as a 4D printing materials. Synthetization of a material that actuates when exposed to stimulus can be a very difficult process, and merging that same material with the ability to be 3D printed can be further difficult. A common 3D printing thermoplastic, poly(lactic) acid (PLA), is used as a shape memory material that is 3D printed using a fused deposition machine (FDM) and combined with nylon fabric for the exploration of smart textiles. The research shows that post printed PLA possesses shape memory properties depending on the thickness of the 3D printed material and the activation temperature. PLA can be thermomechanically trained into temporary shapes and return to its original shape when exposed to high temperatures. PLA can be 3D printed onto nylon fabrics for the creation of the smart textiles. Additionally, a photoisomerable shape changing material is explored because light activation is wireless, controllable, focusable, abundant, causes rapid shape change of the smart material, and induces reversible shape change in the material. This study supports the fundamental research to generate knowledge needed for synthesis of a novel azobenzene shape changing polymer (SCP) and integrating this smart material into objects printed with a 4D printing process using syringe printing. Multiple versions of azobenzene SCP are synthesized that actuate when exposed to 365 nm and 455 nm light. Two SCPs, MeOABHx and DR1Hx, are selected for the 4D printing

National parks, ecological integrity and climatic change

International Nuclear Information System (INIS)

Lopoukhine, N.

1990-01-01

The potential impacts of climate change on the national parks of Canada are discussed. There is a requirement to protect and manage national parks to maintain a functioning ecosystem with all its parts and processes. An active management regime is necessary, with objectives of ecological diversity/integrity clearly stated. The national parks located in the Canadian Prairie provinces are on or near transitions from forest to tundra and grasslands, and are likely to exhibit the most dramatic changes. The change in vegetation of such parks and in others will not manifest itself simply as a shift of zones but will be accompanied by a flora with new dominants. The boreal forest within the Prairie provinces is fire dependent and has the potential of being transformed into remnant units should post-fire germination be hampered by climatic change. A rapid change in climate would render national parks unable to provide protection of representative elements of Canada's landscapes as presently known. A threefold increase in the area dedicated to protection is a basic component of the sustainable development prescription. All government and private lands dedicated to protection should be forged into a network, to provide core protection for immigrating and emigrating communities and individual species displaced by a changing climate. 20 refs., 2 figs

A MATHEMATICAL MODEL OF OPTIMIZATION OF THE VOLUME OF MATERIAL FLOWS IN GRAIN PROCESSING INTEGRATED PRODUCTION SYSTEMS

OpenAIRE

Baranovskaya T. P.; Loyko V. I.; Makarevich O. A.; Bogoslavskiy S. N.

2014-01-01

The article suggests a mathematical model of optimization of the volume of material flows: the model for the ideal conditions; the model for the working conditions; generalized model of determining the optimal input parameters. These models optimize such parameters of inventory management in technology-integrated grain production systems, as the number of cycles supply, the volume of the source material and financial flows. The study was carried out on the example of the integrated system of ...

Corporate Disclosure, Materiality, and Integrated Report: An Event Study Analysis

Directory of Open Access Journals (Sweden)

Maria Cleofe Giorgino

2017-11-01

Full Text Available Within the extensive literature investigating the impacts of corporate disclosure in supporting the sustainable growth of an organization, few studies have included in the analysis the materiality issue referred to the information being disclosed. This article aims to address this gap, exploring the effect produced on capital markets by the publication of a recent corporate reporting tool, Integrated Report (IR. The features of this tool are that it aims to represent the multidimensional impact of the organization’s activity and assumes materiality as a guiding principle of the report drafting. Adopting the event study methodology associated with a statistical significance test for categorical data, our results verify that an organization’s release of IR is able to produce a statistically significant impact on the related share prices. Moreover, the term “integrated” assigned to the reports plays a significant role in the impact on capital markets. Our findings have beneficial implications for both researchers and practitioners, adding new evidence for the IR usefulness as a corporate disclosure tool and the effect of an organization’s decision to disclose material information.

Material and energy recovery in integrated waste management systems. An evaluation based on life cycle assessment

International Nuclear Information System (INIS)

Giugliano, Michele; Cernuschi, Stefano; Grosso, Mario; Rigamonti, Lucia

2011-01-01

This paper reports the environmental results, integrated with those arising from mass and energy balances, of a research project on the comparative analysis of strategies for material and energy recovery from waste, funded by the Italian Ministry of Education, University and Research. The project, involving the cooperation of five University research groups, was devoted to the optimisation of material and energy recovery activities within integrated municipal solid waste (MSW) management systems. Four scenarios of separate collection (overall value of 35%, 50% without the collection of food waste, 50% including the collection of food waste, 65%) were defined for the implementation of energetic, environmental and economic balances. Two sizes of integrated MSW management system (IWMS) were considered: a metropolitan area, with a gross MSW production of 750,000 t/year and an average province, with a gross MSW production of 150,000 t/year. The environmental analysis was conducted using Life Cycle Assessment methodology (LCA), for both material and energy recovery activities. In order to avoid allocation we have used the technique of the expansion of the system boundaries. This means taking into consideration the impact on the environment related to the waste management activities in comparison with the avoided impacts related to the saving of raw materials and primary energy. Under the hypotheses of the study, both for the large and for the small IWMS, the energetic and environmental benefits are higher than the energetic and environmental impacts for all the scenarios analysed in terms of all the indicators considered: the scenario with 50% separate collection in a drop-off scheme excluding food waste shows the most promising perspectives, mainly arising from the highest collection (and recycling) of all the packaging materials, which is the activity giving the biggest energetic and environmental benefits. Main conclusions of the study in the general field of the

Assessing the integrity of local area network materials accountability systems against insider threats

International Nuclear Information System (INIS)

Jones, E.; Sicherman, A.

1996-07-01

DOE facilities rely increasingly on computerized systems to manage nuclear materials accountability data and to protect against diversion of nuclear materials or other malevolent acts (e.g., hoax due to falsified data) by insider threats. Aspects of modern computerized material accountability (MA) systems including powerful personal computers and applications on networks, mixed security environments, and more users with increased knowledge, skills and abilities help heighten the concern about insider threats to the integrity of the system. In this paper, we describe a methodology for assessing MA applications to help decision makers identify ways of and compare options for preventing or mitigating possible additional risks from the insider threat. We illustrate insights from applying the methodology to local area network materials accountability systems

The resilience of integrated agricultural systems to climate change

NARCIS (Netherlands)

Dias Bernardes Gil, Juliana; Cohn, Avery S.; Duncan, John; Newton, Peter; Vermeulen, Sonja

2017-01-01

We reviewed studies addressing the extent to which more integrated agricultural systems (IAS) have been found to be more resilient to climate variability and climate change than more specialized agricultural systems. We found limited literature directly addressing the topic, necessitating the use of

Effect of phase change material on the heat transfer rate of different building materials

Science.gov (United States)

Hasan, Mushfiq; Alam, Shahnur; Ahmed, Dewan Hasan

2017-12-01

Phase change material (PCM) is widely known as latent heat storage. A comprehensive study is carried out to investigate the effect of PCM on heat transfer rate of building materials. Paraffin is used as PCM along with different conventional building materials to investigate the heat transfer rate from the heated region to the cold region. PCM is placed along with the three different types of building materials like plaster which is well know building material in urban areas and wood and straw which are commonly used in rural areas for roofing as well as wall panel material and investigated the heat transfer rate. An experimental setup was constructed with number of rectangular shape aluminum detachable casing (as cavity) and placed side by side. Series of rectangular cavity filled with convent ional building materials and PCM and these were placed in between two chambers filled with water at different temperature. Building materials and PCM were placed in different cavities with different combinations and investigated the heat transfer rate. The results show that using the PCM along with other building materials can be used to maintain lower temperature at the inner wall and chamber of the cold region. Moreover, the placement or orientation of the building materials and PCM make significant contribution to heat transfer rate from the heated zone to the cold zone.

Post-material values and environmental policy change

Energy Technology Data Exchange (ETDEWEB)

Watts, N. (International Inst. for Environmental and Society, Berlin, Germany); Wandesforde-Smith, G.

Environmental policy may be particularly suited as a vehicle to articulate post-material values in advanced industrial societies, and recognition of this is likely to prove enormously helpful in future comparative and cross-national research into the origins of environmentalism and the causes of environmental policy change. The paper notes the salient characteristics of post-materialism and the overlap of these with the leading indicators of environmentalism. Possible structural causes for this overlap are noted and opposed to the prevailing socialization explanation for the adoption of post-material and environmental values. To help understand the impact of environmentalism on policy, an idealized development of the movement is sketched. This leads to the description of a set of general factors likely to be related to the way environmentalism finds political expressions in various countries. In the final section, the focus is on what we might want to know about the policy process in order to be able to gauge environmentalist influence on policy outputs. 20 references.

Integrated risk reduction framework to improve railway hazardous materials transportation safety.

Science.gov (United States)

Liu, Xiang; Saat, M Rapik; Barkan, Christopher P L

2013-09-15

Rail transportation plays a critical role to safely and efficiently transport hazardous materials. A number of strategies have been implemented or are being developed to reduce the risk of hazardous materials release from train accidents. Each of these risk reduction strategies has its safety benefit and corresponding implementation cost. However, the cost effectiveness of the integration of different risk reduction strategies is not well understood. Meanwhile, there has been growing interest in the U.S. rail industry and government to best allocate resources for improving hazardous materials transportation safety. This paper presents an optimization model that considers the combination of two types of risk reduction strategies, broken rail prevention and tank car safety design enhancement. A Pareto-optimality technique is used to maximize risk reduction at a given level of investment. The framework presented in this paper can be adapted to address a broader set of risk reduction strategies and is intended to assist decision makers for local, regional and system-wide risk management of rail hazardous materials transportation. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental data showing the thermal behavior of a flat roof with phase change material.

Science.gov (United States)

Tokuç, Ayça; Başaran, Tahsin; Yesügey, S Cengiz

2015-12-01

The selection and configuration of building materials for optimal energy efficiency in a building require some assumptions and models for the thermal behavior of the utilized materials. Although the models for many materials can be considered acceptable for simulation and calculation purposes, the work for modeling the real time behavior of phase change materials is still under development. The data given in this article shows the thermal behavior of a flat roof element with a phase change material (PCM) layer. The temperature and energy given to and taken from the building element are reported. In addition the solid-liquid behavior of the PCM is tracked through images. The resulting thermal behavior of the phase change material is discussed and simulated in [1] A. Tokuç, T. Başaran, S.C. Yesügey, An experimental and numerical investigation on the use of phase change materials in building elements: the case of a flat roof in Istanbul, Build. Energy, vol. 102, 2015, pp. 91-104.

An integrated approach to change leadership.

Science.gov (United States)

Skelton-Green, Judith; Simpson, Beverley; Scott, Julia

2007-01-01

Leading change has become one of the essential core competencies of health professionals today. Since 2001, the authors have been the key designers and facilitators of the Dorothy Wylie Nursing Leadership Institute (DMW-NLI). The background, key characteristics and benefits of the DMW-NLI have been described in detail elsewhere (Simpson et al. 2002). One of the Institute's key features is that participants bring a change initiative that they wish to pursue and - during their time on site - we assist them in developing that project to the point where it has a strong chance of success. When we incorporated this aspect into the DMW-NLI program, we believed that opportunity to apply the learning of the Institute to a desired initiative in the home setting would add significant value, not only to the participants, but also to their sponsoring organizations. Further, it was our hope that we could develop a methodology to advance the change initiative, which would be a valuable tool that participants could use in future change projects.As we looked to the literature, we found no shortage of articles on change theory, as well as numerous tools and techniques for project management. However, we did not find one single approach or methodology that we felt was comprehensive yet concise enough to serve as a practical guide for those who wish to advance a change initiative in their practice settings today. Therefore, we developed an integrated conceptual framework and methodology for leading change initiatives, building on selected current and classic theories of change that are relevant today. Both the framework and methodology have proven very hardy, and will, we believe, be of interest to nurse leaders and other health professionals in leadership roles. This paper will provide a brief overview of relevant background literature on leading change initiatives, introduce the DMW-NLI Change Leadership conceptual framework, describe a number of activities that support the

Relation between bandgap and resistance drift in amorphous phase change materials.

Science.gov (United States)

Rütten, Martin; Kaes, Matthias; Albert, Andreas; Wuttig, Matthias; Salinga, Martin

2015-12-01

Memory based on phase change materials is currently the most promising candidate for bridging the gap in access time between memory and storage in traditional memory hierarchy. However, multilevel storage is still hindered by the so-called resistance drift commonly related to structural relaxation of the amorphous phase. Here, we present the temporal evolution of infrared spectra measured on amorphous thin films of the three phase change materials Ag4In3Sb67Te26, GeTe and the most popular Ge2Sb2Te5. A widening of the bandgap upon annealing accompanied by a decrease of the optical dielectric constant ε∞ is observed for all three materials. Quantitative comparison with experimental data for the apparent activation energy of conduction reveals that the temporal evolution of bandgap and activation energy can be decoupled. The case of Ag4In3Sb67Te26, where the increase of activation energy is significantly smaller than the bandgap widening, demonstrates the possibility to identify new phase change materials with reduced resistance drift.

Integrating Climate Change Science and Sustainability in Environmental Science, Sociology, Philosophy and Business Courses.

Science.gov (United States)

Boudrias, M. A.; Cantzler, J.; Croom, S.; Huston, C.; Woods, M.

2015-12-01

Courses on sustainability can be taught from multiple perspectives with some focused on specific areas (environmental, socio-cultural, economic, ethics) and others taking a more integrated approach across areas of sustainability and academic disciplines. In conjunction with the Climate Change Education Program efforts to enhance climate change literacy with innovative approaches, resources and communication strategies developed by Climate Education Partners were used in two distinct ways to integrate climate change science and impacts into undergraduate and graduate level courses. At the graduate level, the first lecture in the MBA program in Sustainable Supply Chain Management is entirely dedicated to climate change science, local and global impacts and discussions about key messages to communicate to the business community. Basic science concepts are integrated with discussions about mitigation and adaptation focused on business leaders. The concepts learned are then applied to the semester-long business plan project for the students. At the undergraduate level, a new model of comprehensive integration across disciplines was implemented in Spring 2015 across three courses on Sustainability each with a specific lens: Natural Science, Sociology and Philosophy. All three courses used climate change as the 'big picture' framing concept and had similar learning objectives creating a framework where lens-specific topics, focusing on depth in a discipline, were balanced with integrated exercises across disciplines providing breadth and possibilities for integration. The comprehensive integration project was the creation of the climate action plan for the university with each team focused on key areas of action (water, energy, transportation, etc.) and each team built with at least one member from each class ensuring a natural science, sociological and philosophical perspective. The final project was presented orally to all three classes and an integrated paper included

Microencapsulated Phase Change Composite Materials for Energy Efficient Buildings

Science.gov (United States)

Thiele, Alexander

This study aims to elucidate how phase change material (PCM)-composite materials can be leveraged to reduce the energy consumption of buildings and to provide cost savings to ratepayers. Phase change materials (PCMs) can store thermal energy in the form of latent heat when subjected to temperatures exceeding their melting point by undergoing a phase transition from solid to liquid state. Reversibly, PCMs can release this thermal energy when the system temperature falls below their solidification point. The goal in implementing composite PCM walls is to significantly reduce and time-shift the maximum thermal load on the building in order to reduce and smooth out the electricity demand for heating and cooling. This Ph.D. thesis aims to develop a set of thermal design methods and tools for exploring the use of PCM-composite building envelopes and for providing design rules for their practical implementation. First, detailed numerical simulations were used to show that the effective thermal conductivity of core-shell-matrix composites depended only on the volume fraction and thermal conductivity of the constituent materials. The effective medium approximation reported by Felske (2004) was in very good agreement with numerical predictions of the effective thermal conductivity. Second, a carefully validated transient thermal model was used to simulate microencapsulated PCM-composite walls subjected to diurnal or annual outdoor temperature and solar radiation flux. It was established that adding microencapsulated PCM to concrete walls both substantially reduced and delayed the thermal load on the building. Several design rules were established, most notably, (i) increasing the volume fraction of microencapsulated PCM within the wall increases the energy savings but at the potential expense of mechanical properties [1], (ii) the phase change temperature leading to the maximum energy and cost savings should equal the desired indoor temperature regardless of the climate

Integration mockup and process material management system

Science.gov (United States)

Verble, Adas James, Jr.

1992-01-01

Work to define and develop a full scale Space Station Freedom (SSF) mockup with the flexibility to evolve into future designs, to validate techniques for maintenance and logistics and verify human task allocations and support trade studies is described. This work began in early 1985 and ended in August, 1991. The mockups are presently being used at MSFC in Building 4755 as a technology and design testbed, as well as for public display. Micro Craft also began work on the Process Material Management System (PMMS) under this contract. The PMMS simulator was a sealed enclosure for testing to identify liquids, gaseous, particulate samples, and specimen including, urine, waste water, condensate, hazardous gases, surrogate gasses, liquids, and solids. The SSF would require many trade studies to validate techniques for maintenance and logistics and verify system task allocations; it was necessary to develop a full scale mockup which would be representative of current SSF design with the ease of changing those designs as the SSF design evolved and changed. The tasks defined for Micro Craft were to provide the personnel, services, tools, and materials for the SSF mockup which would consist of four modules, nodes, interior components, and part task mockups of MSFC responsible engineering systems. This included the Engineering Control and Life Support Systems (ECLSS) testbed. For the initial study, the mockups were low fidelity, soft mockups of graphics art bottle, and other low cost materials, which evolved into higher fidelity mockups as the R&D design evolved, by modifying or rebuilding, an important cost saving factor in the design process. We designed, fabricated, and maintained the full size mockup shells and support stands. The shells consisted of cylinders, end cones, rings, longerons, docking ports, crew airlocks, and windows. The ECLSS required a heavier cylinder to support the ECLSS systems test program. Details of this activity will be covered. Support stands were

Unique Bond Breaking in Crystalline Phase Change Materials and the Quest for Metavalent Bonding.

Science.gov (United States)

Zhu, Min; Cojocaru-Mirédin, Oana; Mio, Antonio M; Keutgen, Jens; Küpers, Michael; Yu, Yuan; Cho, Ju-Young; Dronskowski, Richard; Wuttig, Matthias

2018-05-01

Laser-assisted field evaporation is studied in a large number of compounds, including amorphous and crystalline phase change materials employing atom probe tomography. This study reveals significant differences in field evaporation between amorphous and crystalline phase change materials. High probabilities for multiple events with more than a single ion detected per laser pulse are only found for crystalline phase change materials. The specifics of this unusual field evaporation are unlike any other mechanism shown previously to lead to high probabilities of multiple events. On the contrary, amorphous phase change materials as well as other covalently bonded compounds and metals possess much lower probabilities for multiple events. Hence, laser-assisted field evaporation in amorphous and crystalline phase change materials reveals striking differences in bond rupture. This is indicative for pronounced differences in bonding. These findings imply that the bonding mechanism in crystalline phase change materials differs substantially from conventional bonding mechanisms such as metallic, ionic, and covalent bonding. Instead, the data reported here confirm a recently developed conjecture, namely that metavalent bonding is a novel bonding mechanism besides those mentioned previously. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electronic transport in amorphous phase-change materials

International Nuclear Information System (INIS)

Luckas, Jennifer Maria

2012-01-01

Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a

Electronic transport in amorphous phase-change materials

Energy Technology Data Exchange (ETDEWEB)

Luckas, Jennifer Maria

2012-09-14

Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a

Experimental Studies of Phase Change and Microencapsulated Phase Change Materials in a Cold Storage/Transportation System with Solar Driven Cooling Cycle

Directory of Open Access Journals (Sweden)

Lin Zheng

2017-11-01

Full Text Available The paper presents the different properties of phase change material (PCM and Microencapsulated phase change material (MEPCM employed to cold storage/transportation system with a solar-driven cooling cycle. Differential Scanning Calorimeter (DSC tests have been performed to analyze the materials enthalpy, melting temperature range, and temperature range of solidification. KD2 Pro is used to test the thermal conductivities of phase change materials slurry and the results were used to compare the materials heat transfer performance. The slurry flow characteristics of MEPCM slurry also have been tested. Furthermore, in order to analyze the improvement effect on stability, the stability of MEPCM slurry with different surfactants have been tested. The researches of the PCM and MEPCM thermal properties revealed a more prospective application for phase change materials in energy storage/transportation systems. The study aims to find the most suitable chilling medium to further optimize the design of the cold storage/transportation systems with solar driven cooling cycles.

Strongly nonlinear optical glass fibers from noncentrosymmetric phase-change chalcogenide materials.

Science.gov (United States)

Chung, In; Jang, Joon I; Malliakas, Christos D; Ketterson, John B; Kanatzidis, Mercouri G

2010-01-13

We report that the one-dimensional polar selenophosphate compounds APSe(6) (A = K, Rb), which show crystal-glass phase-change behavior, exhibit strong second harmonic generation (SHG) response in both crystal and glassy forms. The crystalline materials are type-I phase-matchable with SHG coefficients chi((2)) of 151.3 and 149.4 pm V(-1) for K(+) and Rb(+) salts, respectively, which is the highest among phase-matchable nonlinear optical (NLO) materials with band gaps over 1.0 eV. The glass of APSe(6) exhibits comparable SHG intensities to the top infrared NLO material AgGaSe(2) without any poling treatments. APSe(6) exhibit excellent mid-IR transparency. We demonstrate that starting from noncentrosymmetric phase-change materials such as APSe(6) (A = K, Rb), we can obtain optical glass fibers with strong, intrinsic, and temporally stable second-order nonlinear optical (NLO) response. The as-prepared glass fibers exhibit SHG and difference frequency generation (DFG) responses over a wide range of wavelengths. Raman spectroscopy and pair distribution function (PDF) analyses provide further understanding of the local structure in amorphous state of KPSe(6) bulk glass and glass fiber. We propose that this approach can be widely applied to prepare permanent NLO glass from materials that undergo a phase-change process.

Effectiveness of integrated science instructional material on pressure in daily life theme to improve digital age literacy of students

Science.gov (United States)

Asrizal; Amran, A.; Ananda, A.; Festiyed; Khairani, S.

2018-04-01

Integrated science learning and literacy skills are relevant issues in Indonesian’s education. However, the use of the integrated science learning and the integration of literacy in learning cannot be implemented well. An alternative solution of this problem is to develop integrated science instructional material on pressure in daily life theme by integrating digital age literacy. Purpose of research is to investigate the effectiveness of the use of integrated science instructional material on pressure in daily life theme to improve knowledge competence, attitudes competence and literacy skills of students. This research was a part of development research which has been conducted. In the product testing stage of this research and development was used before and after design of treatment for one sample group. Instruments to collect the data consist of learning outcomes test sheet, attitude observation sheet, and performance assessment sheet of students. Data analysis techniques include descriptive statistics analysis, normality test, homogeneity test, and paired comparison test. Therefore, the important result of research is the use of integrated science instructional material on pressure in daily life theme is effective in scientific approach to improve knowledge competence, attitudes competence, and digital age literacy skills of grade VIII students at 95% confidence level.

Philosophy of integrity assessment of engineering components

International Nuclear Information System (INIS)

Chaudhuri, Satyabrata

2008-01-01

Integrity assessment of engineering components in power plants and process industries has attracted global attention from the viewpoint of safety and economy for their optimum utilization. This paper describes some aspects of philosophy of component integrity such as life assessment technology, materials used and the factors limiting the serviceability of the components operating at high temperatures and pressures. Numerous investigations have been carried out all over the world to study changes in microstructure and material property due to prolonged service of the components to decide their further serviceability. This paper includes case studies on integrity assessment of service-exposed components carried out in our laboratory as well

Dry powder mixes comprising phase change materials

Science.gov (United States)

Salyer, Ival O.

1992-01-01

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

75 FR 69078 - Workshop To Review Draft Materials for the Lead (Pb) Integrated Science Assessment (ISA)

Science.gov (United States)

2010-11-10

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9224-7] Workshop To Review Draft Materials for the Lead (Pb) Integrated Science Assessment (ISA) AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of Workshop... (NAAQS) for Lead (Pb), EPA is announcing that a workshop to evaluate initial draft materials for the Pb...

Optically-controlled long-term storage and release of thermal energy in phase-change materials.

Science.gov (United States)

Han, Grace G D; Li, Huashan; Grossman, Jeffrey C

2017-11-13

Thermal energy storage offers enormous potential for a wide range of energy technologies. Phase-change materials offer state-of-the-art thermal storage due to high latent heat. However, spontaneous heat loss from thermally charged phase-change materials to cooler surroundings occurs due to the absence of a significant energy barrier for the liquid-solid transition. This prevents control over the thermal storage, and developing effective methods to address this problem has remained an elusive goal. Herein, we report a combination of photo-switching dopants and organic phase-change materials as a way to introduce an activation energy barrier for phase-change materials solidification and to conserve thermal energy in the materials, allowing them to be triggered optically to release their stored latent heat. This approach enables the retention of thermal energy (about 200 J g -1 ) in the materials for at least 10 h at temperatures lower than the original crystallization point, unlocking opportunities for portable thermal energy storage systems.

Experimental data showing the thermal behavior of a flat roof with phase change material

Directory of Open Access Journals (Sweden)

Ayça Tokuç

2015-12-01

Full Text Available The selection and configuration of building materials for optimal energy efficiency in a building require some assumptions and models for the thermal behavior of the utilized materials. Although the models for many materials can be considered acceptable for simulation and calculation purposes, the work for modeling the real time behavior of phase change materials is still under development. The data given in this article shows the thermal behavior of a flat roof element with a phase change material (PCM layer. The temperature and energy given to and taken from the building element are reported. In addition the solid–liquid behavior of the PCM is tracked through images. The resulting thermal behavior of the phase change material is discussed and simulated in [1] A. Tokuç, T. Başaran, S.C. Yesügey, An experimental and numerical investigation on the use of phase change materials in building elements: the case of a flat roof in Istanbul, Build. Energy, vol. 102, 2015, pp. 91–104.

Analyse of possibilities of increasing housing energy efficiency by application of phase-changing materials

Directory of Open Access Journals (Sweden)

Vučeljić-Vavan Sanja

2009-01-01

Full Text Available Refurbishment of existing building stock using energy-saving phase-changing smart materials and technologies, in addition to improved indoor climatic conditions, offer an opportunity for increasing housing energy efficiency and value. This fast developing technology becomes increasingly cost-effective with much shorter payback periods. However, it is undertaken only on a limited scale; because of lack of knowledge about their changeable properties and dynamism in that they behave in response to energy fields. Main characteristics, which make them different form others, are: immediacy transience, self-actuation, selectivity and directness. Phase change processes invariably involve the absorbing, storing or releasing of large amounts of energy in the form of latent heat. These processes are reversible and phase-changing materials can undergo an unlimited number of cycles without degradation. Since phase-changing materials can be designed to absorb or release energy at predictable temperatures, they have naturally been explored for use in architecture as a way of helping deal with the thermal environment in a building. Technologies based on sealing phase-changing materials into small pellets have achieved widespread use in connection with radiant floor heating systems, phase change wallboards, mortar or facade systems. Thermal characteristics of existing buildings can be improved on increasing their thermal-stored mass by implementation products of phase-changing smart materials. In addition to contributing to carbon reduction and energy security, using phase-changing materials in the building sector stimulates innovations.

Investigation of Effect Additive Phase Change Materials on the Thermal Conductivity

Science.gov (United States)

Nakielska, Magdalena; Chalamoński, Mariusz; Pawłowski, Krzysztof

2017-10-01

The aim of worldwide policy is to reduce the amount of consumed energy and conventional fuels. An important branch of the economy that affects the energy balance of the country is construction industry. In Poland, since January 1st, 2017 new limit values have been valid regarding energy saving and thermal insulation of buildings. To meet the requirements of more and more stringent technical and environmental standards, new technological solutions are currently being looked for. When it comes to the use of new materials, phase-change materials are being widely introduced into construction industry. Thanks to phase-change materials, we can increase the amount of heat storage. Great thermal inertia of the building provides more stable conditions inside the rooms and allows the use of unconventional sources of energy such as solar energy. A way to reduce the energy consumption of the object is the use of modern solutions for ventilation systems. An example is the solar chimney, which supports natural ventilation in order to improve internal comfort of the rooms. Numerous studies are being carried out in order to determine the optimal construction of solar chimneys in terms of materials and construction parameters. One of the elements of solar chimneys is an absorption plate, which affects the amount of accumulated heat in the construction. In order to carry out the research on the thermal capacity of the absorption plate, the first research work has been already planned. The work presents the research results of a heat-transfer coefficient of the absorption plates samples made of cement, aggregate, water, and phase-change material in different volume percentage. The work also presents methodology and the research process of phase-change material samples.

Temperature Regulation of Photovoltaic Module Using Phase Change Material: A Numerical Analysis and Experimental Investigation

Directory of Open Access Journals (Sweden)

Hasan Mahamudul

2016-01-01

Full Text Available This work represents an effective design of a temperature regulated PV module by integrating phase change materials for Malaysian weather condition. Through the numerical analysis and experimental investigation it has been shown that if a PCM layer of width 0.02 m of RT 35 is used as a cooling arrangement with a PV module, the surface temperature of the module is reduced by 10°C, which remains constant for a period of 4–6 hours. This reduction of temperature implies the increase in conversion efficiency of the module. Experiment as well as investigation has been carried out considering typical Malaysian weather. Obtained result has been validated by using experimental prototype and comparative analysis.

Thermophysical and Mechanical Properties of Hardened Cement Paste with Microencapsulated Phase Change Materials for Energy Storage.

Science.gov (United States)

Cui, Hongzhi; Liao, Wenyu; Memon, Shazim Ali; Dong, Biqin; Tang, Waiching

2014-12-16

In this research, structural-functional integrated cement-based materials were prepared by employing cement paste and a microencapsulated phase change material (MPCM) manufactured using urea-formaldehyde resin as the shell and paraffin as the core material. The encapsulation ratio of the MPCM could reach up to 91.21 wt%. Thermal energy storage cement pastes (TESCPs) incorporated with different MPCM contents (5%, 10%, 15%, 20% and 25% by weight of cement) were developed, and their thermal and mechanical properties were studied. The results showed that the total energy storage capacity of the hardened cement specimens with MPCM increased by up to 3.9-times compared with that of the control cement paste. The thermal conductivity at different temperature levels (35-36 °C, 55-56 °C and 72-74 °C) decreased with the increase of MPCM content, and the decrease was the highest when the temperature level was 55-56 °C. Moreover, the compressive strength, flexural strength and density of hardened cement paste decreased with the increase in MPCM content linearly. Among the evaluated properties, the compressive strength of TESCPs had a larger and faster degradation with the increase of MPCM content.

Virtual Welded-Joint Design Integrating Advanced Materials and Processing Technologies

Energy Technology Data Exchange (ETDEWEB)

Yang, Z.; Dong, P.; Liu, S.; Babu, S.; Olson, G.; DebRoy, T.

2005-04-15

The primary goal of this project is to increase the fatigue life of a welded-joint by 10 times and to reduce energy use by 25% through product performance and productivity improvements using an integrated modeling approach. The fatigue strength of a welded-joint is currently the bottleneck to design high performance and lightweight welded structures using advanced materials such as high strength steels. In order to achieve high fatigue strength in a welded-joint it is necessary to manage the weld bead shape for lower stress concentration, produce preferable residual stress distribution, and obtain the desired microstructure for improved material toughness and strength. This is a systems challenge that requires the optimization of the welding process, the welding consumable, the base material, as well as the structure design. The concept of virtual welded-joint design has been proposed and established in this project. The goal of virtual welded-joint design is to develop a thorough procedure to predict the relationship of welding process, microstructure, property, residual stress, and the ultimate weld fatigue strength by a systematic modeling approach. The systematic approach combines five sub-models: weld thermal-fluid model, weld microstructure model, weld material property model, weld residual stress model, and weld fatigue model. The systematic approach is thus based on interdisciplinary applied sciences including heat transfer, computational fluid dynamics, materials science, engineering mechanics, and material fracture mechanics. The sub-models are based on existing models with further development. The results from modeling have been validated with critical experiments. The systematic modeling approach has been used to design high fatigue resistant welds considering the combined effects of weld bead geometry, residual stress, microstructure, and material property. In particular, a special welding wire has been developed in this project to introduce

An Integrated Analysis of Changes in Water Stress in Europe

DEFF Research Database (Denmark)

Henrichs, T.; Lehner, B.; Alcamo, J.

2002-01-01

Future changes in water availability with climate change and changes in water use due to socio-economic development are to occur in parallel. In an integrated analysis we bring together these aspects of global change in a consistent manner, and analyse the water stress situation in Europe. We find...... that today high water stress exists in one-fifth of European river basin area. Under a scenario projection, increases in water use throughout Eastern Europe are accompanied by decreases in water availability in most of Southern Europe--combining these trends leads to a marked increase in water stress...

Preparation and thermal properties characterization of carbonate salt/carbon nanomaterial composite phase change material

International Nuclear Information System (INIS)

Tao, Y.B.; Lin, C.H.; He, Y.L.

2015-01-01

Highlights: • Nanocomposite phase change materials were prepared and characterized. • Larger specific surface area is more efficient to enhance specific heat. • Columnar structure is more efficient to enhance thermal conductivity. • Thermal conductivity enhancement is the key. • Single walled carbon nanotube is the optimal nanomaterial additive. - Abstract: To enhance the performance of high temperature salt phase change material, four kinds of carbon nanomaterials with different microstructures were mixed into binary carbonate eutectic salts to prepare carbonate salt/nanomaterial composite phase change material. The microstructures of the nanomaterial and composite phase change material were characterized by scanning electron microscope. The thermal properties such as melting point, melting enthalpy, specific heat, thermal conductivity and total thermal energy storage capacity were characterized. The results show that the nanomaterial microstructure has great effects on composite phase change material thermal properties. The sheet structure Graphene is the best additive to enhance specific heat, which could be enhanced up to 18.57%. The single walled carbon nanotube with columnar structure is the best additive to enhance thermal conductivity, which could be enhanced up to 56.98%. Melting point increases but melting enthalpy decreases with nanomaterial specific surface area increase. Although the additives decrease the melting enthalpy of composite phase change material, they also enhance the specific heat. As a combined result, the additives have little effects on thermal energy storage capacity. So, for phase change material performance enhancement, more emphasis should be placed on thermal conductivity enhancement and single walled carbon nanotube is the optimal nanomaterial additive

Polymeric compositions incorporating polyethylene glycol as a phase change material

Science.gov (United States)

Salyer, Ival O.; Griffen, Charles W.

1989-01-01

A polymeric composition comprising a polymeric material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the composition is useful in making molded and/or coated materials such as flooring, tiles, wall panels and the like; paints containing polyethylene glycols or end-capped polyethylene glycols are also disclosed.

An integral-free expression for short-term changes in fault stability ...

Indian Academy of Sciences (India)

Department of Mathematics, Panjab University, Chandigarh 160 014, India. ∗ ... A concentrated load with step-function time behaviour is placed normal to the planar, ... but integral-free expression for CFSCPP, i.e., changes in fault stability due to changes in pore pressure, .... It is possible to use algebraic and calculus based.

A self-resetting spiking phase-change neuron

Science.gov (United States)

Cobley, R. A.; Hayat, H.; Wright, C. D.

2018-05-01

Neuromorphic, or brain-inspired, computing applications of phase-change devices have to date concentrated primarily on the implementation of phase-change synapses. However, the so-called accumulation mode of operation inherent in phase-change materials and devices can also be used to mimic the integrative properties of a biological neuron. Here we demonstrate, using physical modelling of nanoscale devices and SPICE modelling of associated circuits, that a single phase-change memory cell integrated into a comparator type circuit can deliver a basic hardware mimic of an integrate-and-fire spiking neuron with self-resetting capabilities. Such phase-change neurons, in combination with phase-change synapses, can potentially open a new route for the realisation of all-phase-change neuromorphic computing.

A self-resetting spiking phase-change neuron.

Science.gov (United States)

Cobley, R A; Hayat, H; Wright, C D

2018-05-11

Neuromorphic, or brain-inspired, computing applications of phase-change devices have to date concentrated primarily on the implementation of phase-change synapses. However, the so-called accumulation mode of operation inherent in phase-change materials and devices can also be used to mimic the integrative properties of a biological neuron. Here we demonstrate, using physical modelling of nanoscale devices and SPICE modelling of associated circuits, that a single phase-change memory cell integrated into a comparator type circuit can deliver a basic hardware mimic of an integrate-and-fire spiking neuron with self-resetting capabilities. Such phase-change neurons, in combination with phase-change synapses, can potentially open a new route for the realisation of all-phase-change neuromorphic computing.

Preparation and characterization of a novel polymeric based solid-solid phase change heat storage material

International Nuclear Information System (INIS)

Xi Peng; Gu Xiaohua; Cheng Bowen; Wang Yufei

2009-01-01

Here we reported a two-step procedure for preparing a novel polymeric based solid-solid phase change heat storage material. Firstly, a copolymer monomer containing a polyethylene glycol monomethyl ether (MPEG) phase change unit and a vinyl unit was synthesized via the modification of hydrogen group of MPEG. Secondly, by copolymerization of the copolymer monomer and phenyl ethylene, a novel polymeric based solid-solid phase change heat storage material was prepared. The composition, structure and properties of the novel polymeric based solid-solid phase change material were characterized by IR, 1 H NMR, DSC, WAXD, and POM, respectively. The results show that the novel polymeric based solid-solid phase change material possesses of excellent crystal properties and high phase change enthalpy.

Economic botany collections: A source of material evidence for exploring historical changes in Chinese medicinal materials.

Science.gov (United States)

Brand, Eric; Leon, Christine; Nesbitt, Mark; Guo, Ping; Huang, Ran; Chen, Hubiao; Liang, Li; Zhao, Zhongzhen

2017-03-22

Many Chinese medicinal materials (CMMs) have changed over centuries of use, particularly in terms of their botanical identity and processing methods. In some cases, these changes have important implications for safety and efficacy in modern clinical practice. As most previous research has focused on clarifying the evolution of CMMs by analyzing traditional Chinese materia medica ("bencao") literature, assessments of historical collections are needed to validate these conclusions with material evidence. Historical collections of Chinese medicines reveal the market materials in circulation at a given moment in time, and represent an underexploited resource for analyzing the evolution of Chinese herbal medicines. This study compares specimens from a rare collection of CMMs from the 1920s with contemporary market materials; by highlighting examples of changes in botanical identity and processing that remain relevant for safe clinical practice in the modern era, this work aims to stimulate further research into previously unexplored historical collections of Chinese medicines. 620 specimens of CMMs that were collected from Chinese pharmacies in the Malay peninsula in the 1920s were examined macroscopically and compared with current pharmacopoeia specifications and authentic contemporary samples. These historical specimens, which are stored in the UK in the Economic Botany Collections (EBC) of Royal Botanic Gardens Kew, were morphologically examined, photographed, and compared to authentic CMMs stored at the Bank of China (Hong Kong) Chinese Medicines Center at Hong Kong Baptist University, as well as authentic herbarium-vouchered specimens from the Leon Collection (LC) at the Kew EBC. Case studies were selected to illustrate examples of historical changes in botanical identity, used plant parts, and processing methods. This investigation confirmed that confusion due to shared common names and regional variations in the botanical identity of certain CMMs has been a

Development of Latent Heat Storage Phase Change Material Containing Plaster

Directory of Open Access Journals (Sweden)

Diana BAJARE

2016-05-01

Full Text Available This paper reviews the development of latent heat storage Phase Change Material (PCM containing plaster as in passive application. Due to the phase change, these materials can store higher amounts of thermal energy than traditional building materials and can be used to add thermal inertia to lightweight constructions. It was shown that the use of PCMs have advantages stabilizing the room temperature variations during summer days, provided sufficient night ventilation is allowed. Another advantage of PCM usage is stabilized indoor temperature on the heating season. The goal of this study is to develop cement and lime based plaster containing microencapsulated PCM. The plaster is expected to be used for passive indoor applications and enhance the thermal properties of building envelope. The plaster was investigated under Scanning Electron Microscope and the mechanical, physical and thermal properties of created plaster samples were determined.

Structural properties of the metastable state of phase change materials investigated by synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Merkelbach, Philipp; Eijk, Julia van; Wuttig, Matthias [I. Phys. Institut (IA), RWTH Aachen, 52056 Aachen (Germany); Braun, Carolin [Institut fuer Anorg. Chemie, CAU Kiel, 24098 Kiel (Germany)

2008-07-01

Phase change alloys are among the most promising materials for novel data storage devices. Since several years Phase Change Materials based on Ge-Sb-Te- alloys have been used in optical data storage solutions like rewriteable CDs and DVDs. Recently these alloys have been explored as potential candidates for fast nonvolatile electrical data storage devices in Phase Change Random Access Memory (PCRAM). Besides attracting considerable interest from the commercial point of view phase change materials are very interesting also due to their remarkable physical properties. They have the ability to be reversibly switched within a few nanoseconds between the amorphous and the crystalline phase, while changing their physical properties such as optical reflectivity and electrical resistivity significantly. Even though the electronic properties show a drastical contrast such fast transitions can only be caused by small atomic rearrangements. This behavior calls for a deeper understanding of the structural properties of the alloys. We have performed powder diffraction measurements of the crystal phase of various GeSbTe alloys, to determine the structural similarities and differences of several alloys. Understanding the crystal structure of phase change materials is a key to a deeper insight into the properties of these promising materials.

Does nanoparticles dispersed in a phase change material improve melting characteristics?

NARCIS (Netherlands)

Farsani, Rouhollah Yadollahi; Raisi, Afrasiab; Nadooshan, Afshin Ahmadi; Vanapalli, Srinivas

2017-01-01

Nanoparticles dispersed in a phase change material alter the thermo-physical properties of the base material, such as thermal conductivity, viscosity, and specific heat capacity. These properties combined with the configuration of the cavity, and the location of the heat source, influence the

Tailoring phase change materials: Stoichiometrical trends in the Ge-Sb-Te system

Energy Technology Data Exchange (ETDEWEB)

Klein, Michael; Wamwangi, Daniel; Wuttig, Matthias [I. Physikalisches Institut 1A, RWTH Aachen, 52056 Aachen (Germany)

2007-07-01

Phase change materials are widely used as the active layer in rewritable optical media. This layer can be reversibly switched with a laser beam between an amorphous and crystalline state. As there is a pronounced optical contrast between these two phases, this provides the possibility to write, read and erase data. The speed of this method is limited by the speed of crystallization, as crystallization is the slower process. One possibility to make this process faster is to change the composition of this active layer. Thus it is very interesting to investigate how the process of crystallization is affected by a variation of stoichiometry. Although phase change materials technology is already used, there is little knowledge of the phase change process itself. Today the usability of phase change materials is still identified by try and error methods. We will show stoichiometrical trends of different properties relevant for data storage, e.g. the crystallisation temperature, which governs the room temperature stability of the amorphous phase and thus is a measure for the data retention time.

Feasibility of using microencapsulated phase change materials as filler for improving low temperature performance of rubber sealing materials.

Science.gov (United States)

Tiwari, Avinash; Shubin, Sergey N; Alcock, Ben; Freidin, Alexander B; Thorkildsen, Brede; Echtermeyer, Andreas T

2017-11-01

The feasibility of a novel composite rubber sealing material to improve sealing under transient cooling (in a so-called blowdown scenario) is investigated here. A composite of hydrogenated nitrile butadiene rubber (HNBR) filled with Micro Encapsulated Phase Change Materials (MEPCM) is described. The fillers contain phase change materials that release heat during the phase transformation from liquid to solid while cooling. This exotherm locally heats the rubber and may improve the function of the seal during a blowdown event. A representative HNBR-MEPCM composite was made and the critical thermal and mechanical properties were obtained by simulating the temperature distribution during a blowdown event. Simulations predict that the MEPCM composites can delay the temperature decrease in a region of the seal during the transient blowdown. A sensitivity analysis of material properties is also presented which highlights possible avenues of improvement of the MEPCMs for sealing applications.

Changes in Quality of Health Care Delivery after Vertical Integration.

Science.gov (United States)

Carlin, Caroline S; Dowd, Bryan; Feldman, Roger

2015-08-01

To fill an empirical gap in the literature by examining changes in quality of care measures occurring when multispecialty clinic systems were acquired by hospital-owned, vertically integrated health care delivery systems in the Twin Cities area. Administrative data for health plan enrollees attributed to treatment and control clinic systems, merged with U.S. Census data. We compared changes in quality measures for health plan enrollees in the acquired clinics to enrollees in nine control groups using a differences-in-differences model. Our dataset spans 2 years prior to and 4 years after the acquisitions. We estimated probit models with errors clustered within enrollees. Data were assembled by the health plan's informatics team. Vertical integration is associated with increased rates of colorectal and cervical cancer screening and more appropriate emergency department use. The probability of ambulatory care-sensitive admissions increased when the acquisition caused disruption in admitting patterns. Moving a clinic system into a vertically integrated delivery system resulted in limited increases in quality of care indicators. Caution is warranted when the acquisition causes disruption in referral patterns. © Health Research and Educational Trust.

The implementation of integrated science teaching materials based socio-scientific issues to improve students scientific literacy for environmental pollution theme

Science.gov (United States)

Yenni, Rita; Hernani, Widodo, Ari

2017-05-01

The study aims to determine the increasing of students' science literacy skills on content aspects and competency of science by using Integrated Science teaching materials based Socio-scientific Issues (SSI) for environmental pollution theme. The method used in the study is quasi-experiment with nonequivalent pretest and posttest control group design. The students of experimental class used teaching materials based SSI, whereas the students of control class were still using the usual textbooks. The result of this study showed a significant difference between the value of N-gain of experimental class and control class, whichalso occurred in every indicator of content aspects and competency of science. This result indicates that using of Integrated Science teaching materials based SSI can improve content aspect and competency of science and can be used as teaching materials alternative in teaching of Integrated Science.

Differentiation and Integration: Guiding Principles for Analyzing Cognitive Change

Science.gov (United States)

Siegler, Robert S.; Chen, Zhe

2008-01-01

Differentiation and integration played large roles within classic developmental theories but have been relegated to obscurity within contemporary theories. However, they may have a useful role to play in modern theories as well, if conceptualized as guiding principles for analyzing change rather than as real-time mechanisms. In the present study,…

Thermal energy storage using phase change materials fundamentals and applications

CERN Document Server

Fleischer, Amy S

2015-01-01

This book presents a comprehensive introduction to the use of solid‐liquid phase change materials to store significant amounts of energy in the latent heat of fusion. The proper selection of materials for different applications is covered in detail, as is the use of high conductivity additives to enhance thermal diffusivity. Dr. Fleischer explores how applications of PCMS have expanded over the past 10 years to include the development of high efficiency building materials to reduce heating and cooling needs, smart material design for clothing, portable electronic systems thermal management, solar thermal power plant design and many others. Additional future research directions and challenges are also discussed.

Transient analysis of a thermal storage unit involving a phase change material

Science.gov (United States)

Griggs, E. I.; Pitts, D. R.; Humphries, W. R.

1974-01-01

The transient response of a single cell of a typical phase change material type thermal capacitor has been modeled using numerical conductive heat transfer techniques. The cell consists of a base plate, an insulated top, and two vertical walls (fins) forming a two-dimensional cavity filled with a phase change material. Both explicit and implicit numerical formulations are outlined. A mixed explicit-implicit scheme which treats the fin implicity while treating the phase change material explicitly is discussed. A band algorithmic scheme is used to reduce computer storage requirements for the implicit approach while retaining a relatively fine grid. All formulations are presented in dimensionless form thereby enabling application to geometrically similar problems. Typical parametric results are graphically presented for the case of melting with constant heat input to the base of the cell.

Integrated shape and material selection for single and multi-performance criteria

International Nuclear Information System (INIS)

Singh, Jasveer; Mirjalili, Vahid; Pasini, Damiano

2011-01-01

Research highlights: → The method of shape transformers is extended to torsional stiffness and combined load design. → The method is generalized for multi-criteria selection of shape and material. → Performance charts are presented for single and multi-objective selection of cross-section shape and material. → A four quadrant performance chart is presented to visualize the relation between objective function space and design variable space. -- Abstract: A shape and material selection method, based on the concept of shape transformers, has been recently introduced to characterize the mass efficiency of lightweight beams under bending and shear. This paper extends this method to deal with the case of torsional stiffness design, and generalize it to single and multi-crieria selection of lightweight shafts subjected to a combination of bending, shear, and torsional load. The novel feature of the paper is the useful integration of shape and material to model and visualize multi-objective selection problems. The scheme is centered on concept selection in structural design, and hinges on measures that govern the shape properties of a cross-section regardless of its size. These measures, referred as shape transformers, can classify shapes in a way similar to material classification. The procedure is exemplified by considering torsional stiffness as a constraint. The performance charts are developed for single and multi-criteria to visualize in a glance the whole range of cross-sectional shapes for each material. Each design chart is explained with a brief example.

Microstructure characterization of multi-phase composites and utilization of phase change materials and recycled rubbers in cementitious materials

Science.gov (United States)

Meshgin, Pania

2011-12-01

This research focuses on two important subjects: (1) Characterization of heterogeneous microstructure of multi-phase composites and the effect of microstructural features on effective properties of the material. (2) Utilizations of phase change materials and recycled rubber particles from waste tires to improve thermal properties of insulation materials used in building envelopes. Spatial pattern of multi-phase and multidimensional internal structures of most composite materials are highly random. Quantitative description of the spatial distribution should be developed based on proper statistical models, which characterize the morphological features. For a composite material with multi-phases, the volume fraction of the phases as well as the morphological parameters of the phases have very strong influences on the effective property of the composite. These morphological parameters depend on the microstructure of each phase. This study intends to include the effect of higher order morphological details of the microstructure in the composite models. The higher order statistics, called two-point correlation functions characterize various behaviors of the composite at any two points in a stochastic field. Specifically, correlation functions of mosaic patterns are used in the study for characterizing transport properties of composite materials. One of the most effective methods to improve energy efficiency of buildings is to enhance thermal properties of insulation materials. The idea of using phase change materials and recycled rubber particles such as scrap tires in insulation materials for building envelopes has been studied.

Challenges and Opportunities for Integrating Social Science Perspectives into Climate and Global Change Assessments

Science.gov (United States)

Larson, E. K.; Li, J.; Zycherman, A.

2017-12-01

Integration of social science into climate and global change assessments is fundamental for improving understanding of the drivers, impacts and vulnerability of climate change, and the social, cultural and behavioral challenges related to climate change responses. This requires disciplinary and interdisciplinary knowledge as well as integrational and translational tools for linking this knowledge with the natural and physical sciences. The USGCRP's Social Science Coordinating Committee (SSCC) is tasked with this challenge and is working to integrate relevant social, economic and behavioral knowledge into processes like sustained assessments. This presentation will discuss outcomes from a recent SSCC workshop, "Social Science Perspectives on Climate Change" and their applications to sustained assessments. The workshop brought academic social scientists from four disciplines - anthropology, sociology, geography and archaeology - together with federal scientists and program managers to discuss three major research areas relevant to the USGCRP and climate assessments: (1) innovative tools, methods, and analyses to clarify the interactions of human and natural systems under climate change, (2) understanding of factors contributing to differences in social vulnerability between and within communities under climate change, and (3) social science perspectives on drivers of global climate change. These disciplines, collectively, emphasize the need to consider socio-cultural, political, economic, geographic, and historic factors, and their dynamic interactions, to understand climate change drivers, social vulnerability, and mitigation and adaptation responses. They also highlight the importance of mixed quantitative and qualitative methods to explain impacts, vulnerability, and responses at different time and spatial scales. This presentation will focus on major contributions of the social sciences to climate and global change research. We will discuss future directions for

Contour integral computations for multi-component material systems subjected to creep

International Nuclear Information System (INIS)

Chen, J.-J.; Tu, S.-T.; Xuan, F.-Z.; Wang, Z.-D.

2006-01-01

In the present paper the crack behavior of multi-component material systems is investigated under extensive creep condition. The validation of the creep fracture parameters C* and C(t) is firstly examined at the microscale level. It is found that the C* value is no longer path-independent when mismatch inclusions are embedded into the matrix. To characterize the crack fields in inhomogeneous material the integral value defined at the crack tip as C tip * is introduced to reflect the influence of the inclusion. The interaction effects between microcrack and inclusion are systematically calculated with respect to different mismatch factors, various inclusion locations and inclusion numbers. The analysis results show that the C tip * value is not only influenced by the inclusion properties but also depends on the microstructure near the crack tip

Materials and noncoplanar mesh designs for integrated circuits with linear elastic responses to extreme mechanical deformations.

Science.gov (United States)

Kim, Dae-Hyeong; Song, Jizhou; Choi, Won Mook; Kim, Hoon-Sik; Kim, Rak-Hwan; Liu, Zhuangjian; Huang, Yonggang Y; Hwang, Keh-Chih; Zhang, Yong-wei; Rogers, John A

2008-12-02

Electronic systems that offer elastic mechanical responses to high-strain deformations are of growing interest because of their ability to enable new biomedical devices and other applications whose requirements are impossible to satisfy with conventional wafer-based technologies or even with those that offer simple bendability. This article introduces materials and mechanical design strategies for classes of electronic circuits that offer extremely high stretchability, enabling them to accommodate even demanding configurations such as corkscrew twists with tight pitch (e.g., 90 degrees in approximately 1 cm) and linear stretching to "rubber-band" levels of strain (e.g., up to approximately 140%). The use of single crystalline silicon nanomaterials for the semiconductor provides performance in stretchable complementary metal-oxide-semiconductor (CMOS) integrated circuits approaching that of conventional devices with comparable feature sizes formed on silicon wafers. Comprehensive theoretical studies of the mechanics reveal the way in which the structural designs enable these extreme mechanical properties without fracturing the intrinsically brittle active materials or even inducing significant changes in their electrical properties. The results, as demonstrated through electrical measurements of arrays of transistors, CMOS inverters, ring oscillators, and differential amplifiers, suggest a valuable route to high-performance stretchable electronics.

The Complexity of Integrity Culture Change: A Case Study of a Liberal Arts College

Science.gov (United States)

Bertram Gallant, Tricia

2007-01-01

The concept of academic integrity has been resurrected in both literature and practice in response to a perceived problem of student academic dishonesty. Most specifically, academic integrity advocates suggest changing the student academic culture to normalize academic integrity and reduce occurrences of academic dishonesty. Theories of…

Compliant heterogeneous assemblies of micro-VCSELs as a new materials platform for integrated optoelectronics

Science.gov (United States)

Kang, Dongseok; Lee, Sung-Min; Kwong, Anthony; Yoon, Jongseung

2015-03-01

Despite many unique advantages, vertical cavity surface emitting lasers (VCSELs) have been available mostly on rigid, planar wafers over restricted areas, thereby limiting their usage for applications that can benefit from large-scale, programmable assemblies, hybrid integration with dissimilar materials and devices, or mechanically flexible constructions. Here, materials design and fabrication strategies that address these limitations of conventional VCSELs are presented. Specialized design of epitaxial materials and etching processes, together with printing-based deterministic assemblies and substrate thermal engineering, enabled defect-free release of microscale VCSELs and their device- and circuit-level implementation on non-native, flexible substrates with performance comparable to devices on the growth substrate.

Preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage

International Nuclear Information System (INIS)

Konuklu, Yeliz; Ersoy, Orkun

2016-01-01

Highlights: • Sepiolite-based phase change material nanocomposites were prepared. • An easy direct impregnation process was used. • This paper is one of the first study about sepiolite-based phase change material nanocomposites. • Influence of PCM type on thermal properties of nanocomposites was reported. - Abstract: This paper is one of the first study about the preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage applications. Sepiolite is an important natural fibrous raw material. Nanoscale fibrous tubular structure of sepiolite becomes important in nanocomposite preparation. In this study, sepiolite/paraffin and sepiolite/decanoic acid nanocomposites were manufactured by the direct impregnation method. By the preparation of nanocomposites, PCM move in tubular channels of sepiolite, phase changing occurs in these tubes and surface area increases like as in microencapsulation. The structure and properties of nanocomposites PCMs (CPCM) have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The SEM results prove the successful preparation of phase change material/sepiolite nanocomposites and point out that the fibers of sepiolite is modified with phase change materials in the nanocomposite. The phase change enthalpies of melting and freezing were about 62.08 J/g and −62.05 J/g for sepiolite/paraffin nanocomposites and 35.69 J/g and −34.55 J/g for sepiolite/decanoic acid nanocomposites, respectively. The results show that PCM/sepiolite nanocomposites were prepared successfully and their properties are very suitable for thermal energy storage applications.

Examination of a size-change test for photovoltaic encapsulation materials

Science.gov (United States)

Miller, David C.; Gu, Xiaohong; Ji, Liang; Kelly, George; Nickel, Nichole; Norum, Paul; Shioda, Tsuyoshi; Tamizhmani, Govindasamy; Wohlgemuth, John H.

2012-10-01

We examine a proposed test standard that can be used to evaluate the maximum representative change in linear dimensions of sheet encapsulation products for photovoltaic modules (resulting from their thermal processing). The proposed protocol is part of a series of material-level tests being developed within Working Group 2 of the Technical Committee 82 of the International Electrotechnical Commission. The characterization tests are being developed to aid module design (by identifying the essential characteristics that should be communicated on a datasheet), quality control (via internal material acceptance and process control), and failure analysis. Discovery and interlaboratory experiments were used to select particular parameters for the size-change test. The choice of a sand substrate and aluminum carrier is explored relative to other options. The temperature uniformity of +/-5°C for the substrate was confirmed using thermography. Considerations related to the heating device (hot-plate or oven) are explored. The time duration of 5 minutes was identified from the time-series photographic characterization of material specimens (EVA, ionomer, PVB, TPO, and TPU). The test procedure was revised to account for observed effects of size and edges. The interlaboratory study identified typical size-change characteristics, and also verified the absolute reproducibility of +/-5% between laboratories.

Performance evaluation of a thermoelectric energy harvesting device using various phase change materials

International Nuclear Information System (INIS)

Elefsiniotis, A; Becker, T; Kiziroglou, M E; Wright, S W; Toh, T T; Mitcheson, P D; Yeatman, E M; Schmid, U

2013-01-01

This paper compares the performance of a group of organic and inorganic phase change materials for a heat storage thermoelectric energy harvesting device. The device consists of thermoelectric generators and a closed container filled with a phase change material. One side of the generators is mounted on the aircraft fuselage and the other to the thermal mass. The group of inorganic and organic phase change materials was tested across two temperature ranges. These ranges are defined as ''positive'' and ''negative'', with the former being a sweep from +35°C to −5°C and the latter being a sweep from +5°C to −35°C. The performance in terms of electrical energy output and power produced is examined in detail for each group of materials

Validity of Basic Electronic 1 Module Integrated Character Value Based on Conceptual Change Teaching Model to Increase Students Physics Competency in STKIP PGRI West Sumatera

Science.gov (United States)

Hidayati, A.; Rahmi, A.; Yohandri; Ratnawulan

2018-04-01

The importance of teaching materials in accordance with the characteristics of students became the main reason for the development of basic electronics I module integrated character values based on conceptual change teaching model. The module development in this research follows the development procedure of Plomp which includes preliminary research, prototyping phase and assessment phase. In the first year of this research, the module is validated. Content validity is seen from the conformity of the module with the development theory in accordance with the demands of learning model characteristics. The validity of the construct is seen from the linkage and consistency of each module component developed with the characteristic of the integrated learning model of character values obtained through validator assessment. The average validation value assessed by the validator belongs to a very valid category. Based on the validator assessment then revised the basic electronics I module integrated character values based on conceptual change teaching model.

Sb-Te Phase-change Materials under Nanoscale Confinement

Science.gov (United States)

Ihalawela, Chandrasiri A.

Size, speed and efficiency are the major challenges of next generation nonvolatile memory (NVM), and phase-change memory (PCM) has captured a great attention due to its promising features. The key for PCM is rapid and reversible switching between amorphous and crystalline phases with optical or electrical excitation. The structural transition is associated with significant contrast in material properties which can be utilized in optical (CD, DVD, BD) and electronic (PCRAM) memory applications. Importantly, both the functionality and the success of PCM technology significantly depend on the core material and its properties. So investigating PC materials is crucial for the development of PCM technology to realized enhanced solutions. In regards to PC materials, Sb-Te binary plays a significant role as a basis to the well-known Ge-Sb-Te system. Unlike the conventional deposition methods (sputtering, evaporation), electrochemical deposition method is used due to its multiple advantages, such as conformality, via filling capability, etc. First, the controllable synthesis of Sb-Te thin films was studied for a wide range of compositions using this novel deposition method. Secondly, the solid electrolytic nature of stoichiometric Sb2Te3 was studied with respect to precious metals. With the understanding of 2D thin film synthesis, Sb-Te 1D nanowires (18 - 220 nm) were synthesized using templated electrodeposition, where nanoporous anodic aluminum oxide (AAO) was used as a template for the growth of nanowires. In order to gain the controllability over the deposition in high aspect ratio structures, growth mechanisms of both the thin films and nanowires were investigated. Systematic understanding gained thorough previous studies helped to formulate the ultimate goal of this dissertation. In this dissertation, the main objective is to understand the size effect of PC materials on their phase transition properties. The reduction of effective memory cell size in conjunction with

Integration of nanostructured materials with MEMS microhotplate platforms to enhance chemical sensor performance

International Nuclear Information System (INIS)

Benkstein, Kurt D.; Martinez, Carlos J.; Li, Guofeng; Meier, Douglas C.; Montgomery, Christopher B.; Semancik, Steve

2006-01-01

The development of miniaturized chemical sensors is an increasingly active area of research. Such devices, particularly when they feature low mass and low power budgets, can impact a broad range of applications including industrial process monitoring, building security and extraterrestrial exploration. Nanostructured materials, because of their high surface area, can provide critical enhancements in the performance of chemical microsensors. We have worked to integrate nanomaterial films with MEMS (microelectromechanical systems) microhotplate platforms developed at the National Institute of Standards and Technology in order to gain the benefits of both the materials and the platforms in high-performance chemical sensor arrays. Here, we describe our success in overcoming the challenges of integration and the benefits that we have achieved with regard to the critical sensor performance characteristics of sensor response, speed, stability and selectivity. Nanostructured metal oxide sensing films were locally deposited onto microhotplates via chemical vapor deposition and microcapillary pipetting, and conductive polymer nanoparticle films were deposited via electrophoretic patterning. All films were characterized by scanning electron microscopy and evaluated as conductometric gas sensors

Project plan remove special nuclear material from PFP project plutonium finishing plant

International Nuclear Information System (INIS)

BARTLETT, W.D.

1999-01-01

This plan presents the overall objectives, description, justification and planning for the Plutonium Finishing Plant (PFP) Remove Special Nuclear Material (SNM) Materials. The intent of this plan is to describe how this project will be managed and integrated with other facility stabilization and deactivation activities. This plan supplements the overall integrated plan presented in the Plutonium Finishing Plant Integrated Project Management Plan (IPMP), HNF-3617, Rev. 0. This project plan is the top-level definitive project management document for PFP Remove SNM Materials project. It specifies the technical, schedule, requirements and the cost baselines to manage the execution of the Remove SNM Materials project. Any deviations to the document must be authorized through the appropriate change control process

Solid state phase change materials for thermal energy storage in passive solar heated buildings

Science.gov (United States)

Benson, D. K.; Christensen, C.

1983-11-01

A set of solid state phase change materials was evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol, pentaglycerine and neopentyl glycol. Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature within the range from less than 25 deg to 188 deg. Thermophysical properties such as thermal conductivity, density and volumetric expansion were measured. Computer simulations were used to predict the performance of various Trombe wall designs incorporating solid state phase change materials. Optimum performance was found to be sensitive to the choice of phase change temperatures and to the thermal conductivity of the phase change material. A molecular mechanism of the solid state phase transition is proposed and supported by infrared spectroscopic evidence.

A relationship between regional and global GCM surface air temperature changes and its application to an integrated model of climate change

International Nuclear Information System (INIS)

Jonas, M.; Ganopolski, A.V.; Krabec, J.; Olendrzyski, K.; Petoukhov, V.K.

1994-01-01

This study outlines the advantages of combining the Integrated Model to Assess the Greenhouse affect (IMAGE, an integrated quick turnaround, global model of climate change) with a spatially detailed General Circulation Model (GCM), in this case developed at the Max Planck Institute for Meteorology (MPI) in Hamburg. The outcome is a modified IMAGE model that simulates the MPI GCM projections of annual surface air temperature change globally and regionally. IMAGE thus provides policy analysts with integrated and regional information about global warming for a great range of policy-dependent greenhouse gas emission or concentration scenarios, while preserving its quick turnaround time. With the help of IMAGE various regional temperature response simulations have been produced. None of these simulations has yet been performed by any GCM. The simulations reflect the uncertainty range of a future warming. In this study the authors deal only with a simplified subsystem of such an integrated model of climate change, which begins with policy options, neglects the societal component in the greenhouse gas accounting tool, and ends with temperature change as the only output of the climate model. The model the authors employ is the Integrated Model to Assess the Greenhouse Effect (IMAGE, version 1.0), which was developed by the Netherlands National Institute of Public Health and Environmental Protection (RIVM). IMAGE is a scientifically based, parameterized simulation policy model designed to calculate the historical and future effects of greenhouse gases on global surface and surface air temperatures and sea-level rise

InTeGrate's model for developing innovative, adaptable, interdisciplinary curricular materials that reach beyond the geosciences

Science.gov (United States)

Egger, A. E.; Baldassari, C.; Bruckner, M. Z.; Iverson, E. A.; Manduca, C. A.; Mcconnell, D. A.; Steer, D. N.

2013-12-01

InTeGrate is NSF's STEP Center in the geosciences. A major goal of the project is to develop curricula that will increase the geoscience literacy of all students such that they are better positioned to make sustainable decisions in their lives and as part of the broader society. This population includes the large majority of students that do not major in the geosciences, those historically under-represented in the geosciences, and future K-12 teachers. To achieve this goal, we established a model for the development of curricular materials that draws on the distributed expertise of the undergraduate teaching community. Our model seeks proposals from across the higher education community for courses and modules that meet InTeGrate's overarching goals. From these proposals, we select teams of 3-5 instructors from three or more different institutions (and institution types) and pair them with assessment and web experts. Their communication and development process is supported by a robust, web-based content management system (CMS). Over two years, this team develops materials that explicitly address a geoscience-related societal challenge, build interdisciplinary problem-solving skills, make use of real geoscience data, and incorporate geoscientific and systems thinking. Materials are reviewed with the InTeGrate design rubric and then tested by the authors in their own courses, where student learning is assessed. Results are reviewed by the authors and our assessment team to guide revisions. Several student audiences are targeted: students in general education and introductory geoscience courses, pre-service K-12 teachers, students in other science and engineering majors, as well as those in the humanities and social sciences. Curriculum development team members from beyond the geosciences are critical to producing materials that can be adopted for all of these audiences, and we have been successful in engaging faculty from biology, economics, engineering, sociology

Structural integrity of additive materials: Microstructure, fatigue behavior, and surface processing

Science.gov (United States)

Book, Todd A.

Although Additive Manufacturing (AM) offers numerous performance advantages over existing methods, AM structures are not being utilized for critical aerospace and mechanical applications due to uncertainties in their structural integrity as a result of the microstructural variations and defects arising from the AM process itself. Two of these uncertainties are the observed scatter in tensile strength and fatigue lives of direct metal laser sintering (DMLS) parts. With strain localization a precursor for material failure, this research seeks to explore the impact of microstructural variations in DMLS produced materials on strain localization. The first part of this research explores the role of the microstructure in strain localization of DMLS produced IN718 and Ti6Al4V specimens (as-built and post-processed) through the characterization of the linkage between microstructural variations, and the accumulation of plastic strain during monotonic and low cycle fatigue loading. The second part of this research explores the feasibility for the application of select surface processing techniques in-situ during the DMLS build process to alter the microstructure in AlSi10Mg to reduce strain localization and improve material cohesion. This study is based on utilizing experimental observations through the employment of advanced material characterization techniques such as digital image correlation to illustrate the impacts of DMLS microstructural variation.

Verification test for radiation reduction effect and material integrity on PWR primary system by zinc injection

Energy Technology Data Exchange (ETDEWEB)

Kawakami, H.; Nagata, T.; Yamada, M. [Nuclear Power Engineering Corp. (Japan); Kasahara, K.; Tsuruta, T.; Nishimura, T. [Mitsubishi Heavy Industries, Ltd. (Japan); Ishigure, K. [Saitama Inst. of Tech. (Japan)

2002-07-01

Zinc injection is known to be an effective method for the reduction of radiation source in the primary water system of a PWR. There is a need to verify the effect of Zn injection operation on radiation source reduction and materials integrity of PWR primary circuit. In order to confirm the effectiveness of Zn injection, verification test as a national program sponsored by Ministry of Economy, Trade and Industry (METI) was started in 1995 for 7-year program, and will be finished by the end of March in 2002. This program consists of irradiation test and material integrity test. Irradiation test as an In-Pile-Test managed by AEAT Plc(UK) was performed using the LVR-15 reactor of NRI Rez in Check Republic. Furthermore, Out-of-Pile-Test using film adding unit was also performed to obtain supplemental data for In-Pile-Test at Takasago Engineering Laboratory of NUPEC. Material Integrity test was planned to perform constant load test, constant strain test and corrosion test at the same time using large scale Loop and slow strain extension rate testing (SSRT) at Takasago Engineering Laboratory of NUPEC. In this paper, the results of the verification test for Zinc program at present are discussed. (authors)

Review on phase change materials for building applications

Directory of Open Access Journals (Sweden)

Lavinia SOCACIU

2014-11-01

Full Text Available In nowadays, the Phase Change Material (PCM is a viable alternative for reducing the energy consumption and for increase the thermal comfort in buildings. The use of PCM in building applications provides the potential to increase the indoor thermal comfort for occupants due to the reduced indoor temperature fluctuations and lower global energy consumption. The possibility to incorporate the PCM into the material of construction for cooling and heating the buildings gained the interest of researchers from all the world because the PCM have a high heat of fusion, meaning it is capable to storing and release large amounts of energy in the form of heat during its melting and solidifying process at a specific temperature.

An integral-free expression for short-term changes in fault stability ...

Indian Academy of Sciences (India)

A planar fault exists in the PEHS in such a way that the poroelastic behaviour of the medium is unhindered. We derive an approximate but integral-free expression for CFSCPP, i.e., changes in fault stability due to changes in pore pressure, at a point not too far off the line along which the load acts. But, in the interest of ...

Integrating Media Production By Students Into Climate Change Education: Within and Beyond the Classroom

Science.gov (United States)

Rooney-Varga, J. N.; Brisk, A. A.; Grogan, M.; Ledley, T. S.

2012-12-01

Through the Climate Education in an Age of Media (CAM) Project (http://cleanet.org/cced_media/), we have developed approaches to integrate media production by students into climate change education in ways that are engaging, empowering, and can be readily adopted in a wide range of instructional environments. These approaches can be used to overcome many of the challenges that climate change education presents and provide a means to evoke experiential, affective, and social learning pathways. Video production combines many key twenty-first century literacy skills, including content research, writing, an understanding of the power of images and sounds, the ability to use that power, and the ability to manipulate, transform, and distribute digital media. Through collaboration, reflection, and visual expression of concepts, video production facilitates a deeper understanding of material and, potentially, shifts in mental models about climate change. Equally importantly, it provides a means to bridge formal and informal learning by enabling students to educate those beyond the classroom. We have piloted our approach in two intensive summer programs (2011 and 2012) for high school students, during which students learned about climate change science content in lessons that were paired with the production of short media pieces including animations, public service announcements, person-on-the-street interviews, mock trailers, mock news programs, and music videos. Two high school teachers were embedded in the program during the second year, providing feedback and assessment of the feasibility, accessibility, and utility of the approach. The programs culminated with students presenting and discussing their work at public screening events. The media lessons and climate change science content examples used in these programs form the backbone of a toolkit and professional development workshops for middle and high school teachers, in which teachers learn how to incorporate

Global nuclear material monitoring with NDA and C/S data through integrated facility monitoring

International Nuclear Information System (INIS)

Howell, J.A.; Menlove, H.O.; Argo, P.; Goulding, C.; Klosterbuer, S.; Halbig, J.

1996-01-01

This paper focuses on a flexible, integrated demonstration of a monitoring approach for nuclear material monitoring. This includes aspects of item signature identification, perimeter portal monitoring, advanced data analysis, and communication as a part of an unattended continuous monitoring system in an operating nuclear facility. Advanced analysis is applied to the integrated nondestructive assay and containment and surveillance data that are synchronized in time. End result will be the foundation for a cost-effective monitoring system that could provide the necessary transparency even in areas that are denied to foreign nationals of both US and Russia should these processes and materials come under full-scope safeguards or bilateral agreements. Monitoring systems of this kind have the potential to provide additional benefits including improved nuclear facility security and safeguards and lower personnel radiation exposures. Demonstration facilities in this paper include VTRAP-prototype, Los Alamos Critical Assemblies Facility, Kazakhstan BM-350 Reactor monitor, DUPIC radiation monitoring, and JOYO and MONJU radiation monitoring

Thermophysical and Mechanical Properties of Hardened Cement Paste with Microencapsulated Phase Change Materials for Energy Storage

Directory of Open Access Journals (Sweden)

Hongzhi Cui

2014-12-01

Full Text Available In this research, structural-functional integrated cement-based materials were prepared by employing cement paste and a microencapsulated phase change material (MPCM manufactured using urea-formaldehyde resin as the shell and paraffin as the core material. The encapsulation ratio of the MPCM could reach up to 91.21 wt%. Thermal energy storage cement pastes (TESCPs incorporated with different MPCM contents (5%, 10%, 15%, 20% and 25% by weight of cement were developed, and their thermal and mechanical properties were studied. The results showed that the total energy storage capacity of the hardened cement specimens with MPCM increased by up to 3.9-times compared with that of the control cement paste. The thermal conductivity at different temperature levels (35–36 °C, 55–56 °C and 72–74 °C decreased with the increase of MPCM content, and the decrease was the highest when the temperature level was 55–56 °C. Moreover, the compressive strength, flexural strength and density of hardened cement paste decreased with the increase in MPCM content linearly. Among the evaluated properties, the compressive strength of TESCPs had a larger and faster degradation with the increase of MPCM content.

Non-binary Colour Modulation for Display Device Based on Phase Change Materials

Science.gov (United States)

Ji, Hong-Kai; Tong, Hao; Qian, Hang; Hui, Ya-Juan; Liu, Nian; Yan, Peng; Miao, Xiang-Shui

2016-12-01

A reflective-type display device based on phase change materials is attractive because of its ultrafast response time and high resolution compared with a conventional display device. This paper proposes and demonstrates a unique display device in which multicolour changing can be achieved on a single device by the selective crystallization of double layer phase change materials. The optical contrast is optimized by the availability of a variety of film thicknesses of two phase change layers. The device exhibits a low sensitivity to the angle of incidence, which is important for display and colour consistency. The non-binary colour rendering on a single device is demonstrated for the first time using optical excitation. The device shows the potential for ultrafast display applications.

Non-binary Colour Modulation for Display Device Based on Phase Change Materials.

Science.gov (United States)

Ji, Hong-Kai; Tong, Hao; Qian, Hang; Hui, Ya-Juan; Liu, Nian; Yan, Peng; Miao, Xiang-Shui

2016-12-19

A reflective-type display device based on phase change materials is attractive because of its ultrafast response time and high resolution compared with a conventional display device. This paper proposes and demonstrates a unique display device in which multicolour changing can be achieved on a single device by the selective crystallization of double layer phase change materials. The optical contrast is optimized by the availability of a variety of film thicknesses of two phase change layers. The device exhibits a low sensitivity to the angle of incidence, which is important for display and colour consistency. The non-binary colour rendering on a single device is demonstrated for the first time using optical excitation. The device shows the potential for ultrafast display applications.

Nuclear material data management and integration. A safeguard perspective

International Nuclear Information System (INIS)

Wilkey, David D.; Martin, H.R.; O'Leary, Jerry

1999-01-01

This paper is a discussion of the use of available data in the performance of nuclear material (NM) safeguards. The discussion considers the various sources of data and system requirements for collecting and managing that data, and is preliminary concerned with domestic safeguards requirements such as those specified by the US Department of Energy. The preferred configuration for integrated data management does not necessarily require a single computer system; however, separate computerized systems with direct inter-system connections is preferred. Use of all relevant data NM accounting, NM control, physical protection, and non-safeguards) is necessary to assure the most effective protection for the NM inventories. Where direct exchange of data is not possible, a systematic program to implement indirect exchange is essential [ru

Annual energy analysis of concrete containing phase change materials for building envelopes

International Nuclear Information System (INIS)

Thiele, Alexander M.; Jamet, Astrid; Sant, Gaurav; Pilon, Laurent

2015-01-01

Highlights: • Adding PCM to concrete walls can significantly reduce the cooling needs of buildings. • Climate, season, and wall orientation strongly affect energy and cost savings. • The PCM melting temperature should be near the desired indoor temperature. • Benefits are maximum for outdoor temperature oscillating around set indoor temperature. • Adding PCM had little effect on heating energy needs and associated cost savings. - Abstract: This paper examines the annual energy and cost savings potential of adding microencapsulated phase change material to the exterior concrete walls of an average-sized single family home in California climate zones 3 (San Francisco, CA) and 9 (Los Angeles, CA). The annual energy and cost savings were larger for South- and West-facing walls than for other walls. They were also the largest when the phase change temperature was near the desired indoor temperature. The addition of microencapsulated phase change material to the building walls reduced the cooling load in summer substantially more than the heating load in winter. This was attributed to the cold winter temperatures resulting in nearly unidirectional heat flux on many days. The annual cooling load reduction in an average-sized single family home in San Francisco and in Los Angeles ranged from 85% to 100% and from 53% to 82%, respectively, for phase change material volume fraction ranging from 0.1 to 0.3. The corresponding annual electricity cost savings ranged from $36 to $42 in San Francisco and from $94 to $143 in Los Angeles. From an energy standpoint, the best climate for using building materials containing uniformly distributed microencapsulated phase change material would have outdoor temperature oscillations centered around the desired indoor temperature for the entire year

DR-Integrator: a new analytic tool for integrating DNA copy number and gene expression data.

Science.gov (United States)

Salari, Keyan; Tibshirani, Robert; Pollack, Jonathan R

2010-02-01

DNA copy number alterations (CNA) frequently underlie gene expression changes by increasing or decreasing gene dosage. However, only a subset of genes with altered dosage exhibit concordant changes in gene expression. This subset is likely to be enriched for oncogenes and tumor suppressor genes, and can be identified by integrating these two layers of genome-scale data. We introduce DNA/RNA-Integrator (DR-Integrator), a statistical software tool to perform integrative analyses on paired DNA copy number and gene expression data. DR-Integrator identifies genes with significant correlations between DNA copy number and gene expression, and implements a supervised analysis that captures genes with significant alterations in both DNA copy number and gene expression between two sample classes. DR-Integrator is freely available for non-commercial use from the Pollack Lab at http://pollacklab.stanford.edu/ and can be downloaded as a plug-in application to Microsoft Excel and as a package for the R statistical computing environment. The R package is available under the name 'DRI' at http://cran.r-project.org/. An example analysis using DR-Integrator is included as supplemental material. Supplementary data are available at Bioinformatics online.

Integrated Computational study of Material Lifetime in a Fusion Reactor Environment

Energy Technology Data Exchange (ETDEWEB)

Gilbert, M.; Dudarev, S.; Packer, L.; Zheng, S.; Sublet, J.-C., E-mail: mark.gilbert@ccfe.ac.uk [EURATOM/CCFE Fusion Association, Culham Centre for Fusion Energy, Abingdon (United Kingdom)

2012-09-15

Full text: The high-energy, high-intensity neutron fluxes produced by the fusion plasma will have a significant life-limiting impact on reactor components in both experimental and commercial fusion devices. Not only do the neutrons bombarding the materials induce atomic displacement cascades, leading to the accumulation of structural defects, but they also initiate nuclear reactions, which cause transmutation of the elemental atoms. Understanding the implications associated with the resulting compositional changes is one of the key outstanding issues related to fusion energy research. Several complimentary computational techniques have been used to investigate the problem. Firstly, neutron-transport simulations, performed on a reference design for the demonstration fusion power plant (DEMO), quantify the variation in neutron irradiation conditions as a function of geometry. The resulting neutron fluxes and spectra are then used as input into inventory calculations, which allow for the compositional changes of a material to be tracked in time. These calculations reveal that the production of helium (He) gas atoms, whose presence in a material is of particular concern because it can accumulate and cause swelling and embrittlement, will vary significantly, even within the same component of a reactor. Lastly, a density-functional-based model for He-induced grain-boundary embrittlement has been developed to predict the life-limiting consequences associated with relatively low concentrations of He in materials situated at various locations in the DEMO structure. The results suggest that some important fusion materials may be significantly more susceptible to this type of failure than others. (author)

Vision 2040: A Roadmap for Integrated, Multiscale Modeling and Simulation of Materials and Systems

Science.gov (United States)

Liu, Xuan; Furrer, David; Kosters, Jared; Holmes, Jack

2018-01-01

Over the last few decades, advances in high-performance computing, new materials characterization methods, and, more recently, an emphasis on integrated computational materials engineering (ICME) and additive manufacturing have been a catalyst for multiscale modeling and simulation-based design of materials and structures in the aerospace industry. While these advances have driven significant progress in the development of aerospace components and systems, that progress has been limited by persistent technology and infrastructure challenges that must be overcome to realize the full potential of integrated materials and systems design and simulation modeling throughout the supply chain. As a result, NASA's Transformational Tools and Technology (TTT) Project sponsored a study (performed by a diverse team led by Pratt & Whitney) to define the potential 25-year future state required for integrated multiscale modeling of materials and systems (e.g., load-bearing structures) to accelerate the pace and reduce the expense of innovation in future aerospace and aeronautical systems. This report describes the findings of this 2040 Vision study (e.g., the 2040 vision state; the required interdependent core technical work areas, Key Element (KE); identified gaps and actions to close those gaps; and major recommendations) which constitutes a community consensus document as it is a result of over 450 professionals input obtain via: 1) four society workshops (AIAA, NAFEMS, and two TMS), 2) community-wide survey, and 3) the establishment of 9 expert panels (one per KE) consisting on average of 10 non-team members from academia, government and industry to review, update content, and prioritize gaps and actions. The study envisions the development of a cyber-physical-social ecosystem comprised of experimentally verified and validated computational models, tools, and techniques, along with the associated digital tapestry, that impacts the entire supply chain to enable cost

Thermal Protection Performance of Carbon Aerogels Filled with Magnesium Chloride Hexahydrate as a Phase Change Material

Directory of Open Access Journals (Sweden)

Ali Kazemi

2014-02-01

Full Text Available Carbon aerogels are comprised of a class of low density open-cell foams with large void space, nanometer pore size and composed of sparsely semi-colloidal nanometer sized particles forming an open porous structure. Phase change materials are those with high heat of fusion that could absorb and release a large amount of energy at the time of phase transition. These materials are mostly used as thermal energy storage materials but in addition they could serve as an obstacle for passage of heat during phase changes and this has led to their use in thermal protection systems. In this study, the effect of magnesium chloride hexahydrate, as a phase change material (melting point 115°C, on thermal properties of carbon aerogels is investigated. Thermal performance tests are designed and used for comparing the temperature-time behavior of the samples. DSC is applied to obtain the latent heat of melting of the phase change materials and the SEM tests are used to analyze the microstructure and morphology of carbon aerogels. The results show that the low percentage of phase change materials in carbon aerogels does not have any significant positive effect on carbon aerogels thermal properties. However, these properties are improved by increasing the percentage of phase change materials. With high percentage of phase change materials, a sample surface at 300°C would display an opposite surface with a significant drop in temperature increases, while at 115-200°C, with carbon aerogels, having no phase change materials, there is a severe reduction in the rate of temperature increase of the sample.

Integrating Biopsychosocial Intervention Research in a Changing Health Care Landscape

Science.gov (United States)

Ell, Kathleen; Oh, Hyunsung; Wu, Shinyi

2016-01-01

Objective: Safety net care systems are experiencing unprecedented change from the "Affordable Care Act," Patient-Centered Medical Home (PCMH) uptake, health information technology application, and growing of mental health care integration within primary care. This article provides a review of previous and current efforts in which social…

Interface Characterization of Metals and Metal-nitrides to Phase Change Materials

NARCIS (Netherlands)

Roy, Deepu; Gravesteijn, Dirk J; Wolters, Robertus A.M.

2011-01-01

We have investigated the interfacial contact properties of the CMOS compatible electrode materials W, TiW, Ta, TaN and TiN to doped-Sb2Te phase change material (PCM). This interface is characterized both in the amorphous and in the crystalline state of the doped-Sb2Te. The electrical nature of the

Influence of the local structure in phase-change materials on their dielectric permittivity.

Science.gov (United States)

Shportko, Kostiantyn V; Venger, Eugen F

2015-01-01

Ge-Sb-Te alloys, which belong to the phase-change materials, are promising materials for data storage and display and data visualization applications due to their unique properties. This includes a remarkable difference of their electrical and optical properties in the amorphous and crystalline state. Pronounced change of optical properties for Ge-Sb-Te alloys is linked to the different bonding types and different atomic arrangements in amorphous and crystalline states. The dielectric function of phase-change materials has been investigated in the far infrared (FIR) range. Phonons have been detected by FTIR spectroscopy. Difference of the dispersion of the dielectric permittivity of amorphous and crystalline samples is caused by different structures in different states which contribute to the dielectric permittivity.

Results from the European Integrated Project '' New Materials for Extreme Environments (ExtreMat) ''

International Nuclear Information System (INIS)

Bolt, H.; Linsmeier, Ch.; Baluc, N.; Garcia-Rosales, G.; Gualco, G. C.; Simancik, F.

2006-01-01

The goal of the European Integrated Project '' ExtreMat '' is to provide and to industrialize new materials and their compounds for applications in extreme environments that are beyond reach with incremental materials development only. The R(and)D activities in this project aim to provide a) self-passivating protection materials for sensitive structures operated in physico-chemically aggressive environments at high temperatures; b) new heat sink materials with the capability of very efficient heat removal, often at very high temperature level; c) radiation resistant materials for very high operation temperatures; d) new processing routes for complex heterogeneous compounds that can be operated in extreme environments. Key applications for these new materials are in the sectors of fusion, advanced fission, space, and electronic applications. Further use of these materials is expected in spin-off fields, such as brake applications and energy conversion. The project started in December 2004 for a duration of five years and is supported by the European Community. The 37 project participants are from 13 EU member states and include 6 universities, 7 research institutes, 10 research centres and 14 industrial companies. Research results regarding the development of materials for application in nuclear fusion, especially on protection, heat sink, and radiation resistant materials will be presented. A view to other applications of these materials in the fields of fission, space and electronics will be given in the presentation. ExtreMat Project Partners: see http://www.extremat.org/. (author)

Integration of bulk piezoelectric materials into microsystems

Science.gov (United States)

Aktakka, Ethem Erkan

Bulk piezoelectric ceramics, compared to deposited piezoelectric thin-films, provide greater electromechanical coupling and charge capacity, which are highly desirable in many MEMS applications. In this thesis, a technology platform is developed for wafer-level integration of bulk piezoelectric substrates on silicon, with a final film thickness of 5-100microm. The characterized processes include reliable low-temperature (200°C) AuIn diffusion bonding and parylene bonding of bulk-PZT on silicon, wafer-level lapping of bulk-PZT with high-uniformity (+/-0.5microm), and low-damage micro-machining of PZT films via dicing-saw patterning, laser ablation, and wet-etching. Preservation of ferroelectric and piezoelectric properties is confirmed with hysteresis and piezo-response measurements. The introduced technology offers higher material quality and unique advantages in fabrication flexibility over existing piezoelectric film deposition methods. In order to confirm the preserved bulk properties in the final film, diaphragm and cantilever beam actuators operating in the transverse-mode are designed, fabricated and tested. The diaphragm structure and electrode shapes/sizes are optimized for maximum deflection through finite-element simulations. During tests of fabricated devices, greater than 12microm PP displacement is obtained by actuation of a 1mm2 diaphragm at 111kHz with integration of a 50-80% efficient power management IC, which incorporates a supply-independent bias circuitry, an active diode for low-dropout rectification, a bias-flip system for higher efficiency, and a trickle battery charger. The overall system does not require a pre-charged battery, and has power consumption of <1microW in active-mode (measured) and <5pA in sleep-mode (simulated). Under lg vibration at 155Hz, a 70mF ultra-capacitor is charged from OV to 1.85V in 50 minutes.

Characterization of thermophysical properties of phase change materials for non-membrane based indirect solar desalination application

International Nuclear Information System (INIS)

Sarwar, J.; Mansoor, B.

2016-01-01

Highlights: • Thermal cycling of paraffin waxes phase change materials. • Differential Scanning Calorimetry and thermogravimetric study of the materials. • Characterization of the phase change materials via Temperature History Method. • Investigation of suitability of materials for indirect solar desalination system. • Paraffin waxes are suitable for non-membrane indirect solar desalination system. - Abstract: Phase change material as a thermal energy storage medium has been widely incorporated in various technologies like solar air/water heating, buildings, and desalination for efficient use and management of fluctuating solar energy. Temperature and thermal energy requirements dictate the selection of an appropriate phase change material for its application in various engineering systems. In this work, two phase change materials belonging to organic paraffin wax class have been characterized to obtain their thermophysical properties. The melting/solidification temperatures, latent heat of fusion and heat capacities of the phase change materials have been investigated using Differential Scanning Calorimetry, Thermogravimetric analysis and Temperature History Method. Thermal cycles up to 300 are performed to investigate melting and solidification reversibility as well as degradation over time. It is shown that the selected paraffin waxes have reversible phase change with no degradation of thermophysical properties over time. It is also shown that melting/solidification temperature and thermal energy storage capabilities make them suitable for their application as a thermal energy storage medium, in high temperature vapour compression, multi-stage flash and multi-effect distillation processes of non-membrane based indirect desalination systems.

Phase change - memory materials - composition, structure, and properties

Czech Academy of Sciences Publication Activity Database

Frumar, M.; Frumarová, Božena; Wágner, T.; Hrdlička, M.

2007-01-01

Roč. 18, suppl.1 (2007), S169-S174 ISSN 0957-4522. [International Conference on Optical and Optoelectronic Properties of Materials and Applications 2006. Darwin, 16.06.2006-20.06.2006] R&D Projects: GA ČR GA203/06/0627 Institutional research plan: CEZ:AV0Z40500505 Keywords : phase change memory Subject RIV: CA - Inorganic Chemistry Impact factor: 0.947, year: 2007

Changes in electrical transport and density of states of phase change materials upon resistance drift

International Nuclear Information System (INIS)

Krebs, Daniel; Bachmann, Tobias; Jonnalagadda, Prasad; Dellmann, Laurent; Raoux, Simone

2014-01-01

Phase-change memory technology has become more mature in recent years. But some fundamental problems linked to the electrical transport properties in the amorphous phase of phase-change materials still need to be solved. The increase of resistance over time, called resistance drift, for example, poses a major challenge for the implementation of multilevel storage, which will eventually be necessary to remain competitive in terms of high storage densities. To link structural properties with electrical transport, a broader knowledge of (i) changes in the density of states (DoS) upon structural relaxation and (ii) the influence of defects on electrical transport is required. In this paper, we present temperature-dependent conductivity and photo-conductivity measurements on the archetype phase change material GeTe. It is shown that trap-limited band transport at high temperatures (above 165 K) and variable range hopping at low temperatures are the predominating transport mechanism. Based on measurements of the temperature dependence of the optical band gap, modulated photo-conductivity and photo-thermal deflection spectroscopy, a DoS model for GeTe was proposed. Using this DoS, the temperature dependence of conductivity and photo-conductivity has been simulated. Our work shows how changes in the DoS (band gap and defect distributions) will affect the electrical transport before and after temperature-accelerated drift. The decrease in conductivity upon annealing can be explained entirely by an increase of the band gap by about 12%. However, low-temperature photo-conductivity measurements revealed that a change in the defect density may also play a role

Molecular dynamics simulations of melting behavior of alkane as phase change materials slurry

International Nuclear Information System (INIS)

Rao Zhonghao; Wang Shuangfeng; Wu Maochun; Zhang Yanlai; Li Fuhuo

2012-01-01

Highlights: ► The melting behavior of phase change materials slurry was investigated by molecular dynamics simulation method. ► Four different PCM slurry systems including pure water and water/n-nonadecane composite were constructed. ► Amorphous structure and periodic boundary conditions were used in the molecular dynamics simulations. ► The simulated melting temperatures are very close to the published experimental values. - Abstract: The alkane based phase change materials slurry, with high latent heat storage capacity, is effective to enhance the heat transfer rate of traditional fluid. In this paper, the melting behavior of composite phase change materials slurry which consists of n-nonadecane and water was investigated by using molecular dynamics simulation. Four different systems including pure water and water/n-nonadecane composite were constructed with amorphous structure and periodic boundary conditions. The results showed that the simulated density and melting temperature were very close to the published experimental values. Mixing the n-nonadecane into water decreased the mobility but increased the energy storage capacity of composite systems. To describe the melting behavior of alkane based phase change materials slurry on molecular or atomic scale, molecular dynamics simulation is an effective method.

Integrated assessment of climate change with reductions of methane emissions

NARCIS (Netherlands)

Amstel, van A.R.

2005-01-01

We have been living in the anthropocene era since about 1950, and evidence of human influence on the natural ecosystems and climate is mounting. Reductions of greenhouse gas emissions are needed to reduce the effects of climate change in the future. In an integrated assessment with the IMAGE model

Project plan remove special nuclear material from PFP project plutonium finishing plant; TOPICAL

International Nuclear Information System (INIS)

BARTLETT, W.D.

1999-01-01

This plan presents the overall objectives, description, justification and planning for the Plutonium Finishing Plant (PFP) Remove Special Nuclear Material (SNM) Materials. The intent of this plan is to describe how this project will be managed and integrated with other facility stabilization and deactivation activities. This plan supplements the overall integrated plan presented in the Plutonium Finishing Plant Integrated Project Management Plan (IPMP), HNF-3617,Rev. 0. This project plan is the top-level definitive project management document for PFP Remove SNM Materials project. It specifies the technical, schedule, requirements and the cost baselines to manage the execution of the Remove SNM Materials project. Any deviations to the document must be authorized through the appropriate change control process

Mutual Workshops enhancing Curriculum Integration

DEFF Research Database (Denmark)

Bjerregaard Jensen, Lotte; Markvorsen, Steen; Almegaard, Henrik

2011-01-01

. A course in material science was moved from the fourth to the first semester so that the project could be informed by material science. A new course in geometry was prepared and software that could facilitate an integrated design project was introduced (STAAD Pro). The ‘full package’ of the new third....... Every semester has a teaching team consisting of all the teachers for courses in that semester. Each semester also has its own theme and a multidisciplinary, joint project. So the most active members of the teaching team, of course, are those responsible for courses that address the theme and contribute...... to the joint project. The theme of the third semester is ‘structural design’. Structural design is defined as an integration of material science, statics and geometry in relation to an architectural project. Anticipating the implementation of CDIO and this theme, major changes were made to the curriculum...

Electrical transport in crystalline phase change materials

International Nuclear Information System (INIS)

Woda, Michael

2012-01-01

In this thesis, the electrical transport properties of crystalline phase change materials are discussed. Phase change materials (PCM) are a special class of semiconducting and metallic thin film alloys, typically with a high amount of the group five element antimony or the group six element tellurium, such as Ge 2 Sb 2 Te 5 . The unique property portfolio of this material class makes it suitable for memory applications. PCMs reveal fast switching between two stable room-temperature phases (amorphous and crystalline) realized by optical laser or electrical current pulses in memory devices. Additionally, a pronounced property contrast in form of optical reflectivity and electrical conductivity between the amorphous and crystalline phase is the characteristic fingerprint of PCMs. The emerging electrical solid state memory PCRAM is a very promising candidate to replace Flash memory in the near future or to even become a universal memory, which is non-volatile and shows the speed and cyclability of DRAM. One of the main technological challenges is the switching process into the amorphous state, which is the most power demanding step. In order to reduce the switching power, the crystalline resistivity needs to be increased at a given voltage. Thus understanding and tayloring of this property is mandatory. In this work, first the technological relevance, i.e. optical and electrical memory concepts based on PCMs are introduced. Subsequently a description of the physical properties of PCMs in four categories is given. Namely, structure, kinetics, optical properties and electrical properties are discussed. Then important recent developments such as the identification of resonant bonding in crystalline PCMs and a property predicting coordination scheme are briefly reviewed. The following chapter deals with the theoretical background of electrical transport, while the next chapter introduces the experimental techniques: Sputtering, XRR, XRD, DSC, thermal annealing

Earth science information: Planning for the integration and use of global change information

Science.gov (United States)

Lousma, Jack R.

1992-01-01

Activities and accomplishments of the first six months of the Consortium for International Earth Science Information Network (CIESIN's) 1992 technical program have focused on four main missions: (1) the development and implementation of plans for initiation of the Socioeconomic Data and Applications Center (SEDAC) as part of the EOSDIS Program; (2) the pursuit and development of a broad-based global change information cooperative by providing systems analysis and integration between natural science and social science data bases held by numerous federal agencies and other sources; (3) the fostering of scientific research into the human dimensions of global change and providing integration between natural science and social science data and information; and (4) the serving of CIESIN as a gateway for global change data and information distribution through development of the Global Change Research Information Office and other comprehensive knowledge sharing systems.

Initial Atomic Motion Immediately Following Femtosecond-Laser Excitation in Phase-Change Materials.

Science.gov (United States)

Matsubara, E; Okada, S; Ichitsubo, T; Kawaguchi, T; Hirata, A; Guan, P F; Tokuda, K; Tanimura, K; Matsunaga, T; Chen, M W; Yamada, N

2016-09-23

Despite the fact that phase-change materials are widely used for data storage, no consensus exists on the unique mechanism of their ultrafast phase change and its accompanied large and rapid optical change. By using the pump-probe observation method combining a femtosecond optical laser and an x-ray free-electron laser, we substantiate experimentally that, in both GeTe and Ge_{2}Sb_{2}Te_{5} crystals, rattling motion of mainly Ge atoms takes place with keeping the off-center position just after femtosecond-optical-laser irradiation, which eventually leads to a higher symmetry or disordered state. This very initial rattling motion in the undistorted lattice can be related to instantaneous optical change due to the loss of resonant bonding that characterizes GeTe-based phase change materials. Based on the amorphous structure derived by first-principles molecular dynamics simulation, we infer a plausible ultrafast amorphization mechanism via nonmelting.

THERMAL CHARACTERISTICS OF PHASE CHANGE MATERIAL USED AS THERMAL STORAGE SYSTEM BY USING SOLAR ENERGY

Directory of Open Access Journals (Sweden)

Kadhim F. Nasir

2018-01-01

Full Text Available In this paper, the melting processes of phase change material in a shell and tube heat exchanger by using solar thermal energy have been investigated numerically and experimentally. All experimental were outdoor tested at AL-Mussaib city-Babylon-Iraq (Lat 32.5 º North, and long 44.3 º East with N-S collector direction at tilt angle of 32.5 º with the horizontal. The phase change material used in this work is black color Iraqi origin pure Paraffin with amount of 12 kg. In the experimental setup evacuted tube solar collector is employed for melting phase change material in shell regime. Different volume flow rates for the water flow inside the inner tube of heat exchanger namely (200, 300, and 500 LPH for Reynolds number namely (15000, 23000, 38000 respectively were used for each season from August 2016 to January 2017. The numerical investigation involves a three dimension numerical solution of model by a commercial package ANSYS FLUENT 15.0. The boundary conditions of the model that solved by the numerical solution have been taken from the experimental tests. The experimental results indicated that the inner tube inlet and ambient temperatures has a significant effects on the melting process compared with the volume flow rates. Studying phase change material temperature distribution, it is exposed that a melting temperature of the phase change material in summer season needed time of (3-4 hours only, while it needed more time; (14-16 hours in winter season. Increasing solar radiation and ambient temperature reduces the melting time of phase change material. Increasing water temperature difference of inner tube increased the heat gained for phase change material. The results obtained from numerical solution presented the static temperature contours and showed that the temperature distribution of phase change material give good validations with experimental results with percentage deviation of 2.7%. The present experimental results have been

Simultaneous and integrated neutron-based techniques for material analysis of a metallic ancient flute

International Nuclear Information System (INIS)

Festa, G; Andreani, C; Pietropaolo, A; Grazzi, F; Scherillo, A; Barzagli, E; Sutton, L F; Bognetti, L; Bini, A; Schooneveld, E

2013-01-01

A metallic 19th century flute was studied by means of integrated and simultaneous neutron-based techniques: neutron diffraction, neutron radiative capture analysis and neutron radiography. This experiment follows benchmark measurements devoted to assessing the effectiveness of a multitask beamline concept for neutron-based investigation on materials. The aim of this study is to show the potential application of the approach using multiple and integrated neutron-based techniques for musical instruments. Such samples, in the broad scenario of cultural heritage, represent an exciting research field. They may represent an interesting link between different disciplines such as nuclear physics, metallurgy and acoustics. (paper)

An integrated assessment of climate change, air pollution, and energy security policy

International Nuclear Information System (INIS)

Bollen, Johannes; Hers, Sebastiaan; Van der Zwaan, Bob

2010-01-01

This article presents an integrated assessment of climate change, air pollution, and energy security policy. Basis of our analysis is the MERGE model, designed to study the interaction between the global economy, energy use, and the impacts of climate change. For our purposes we expanded MERGE with expressions that quantify damages incurred to regional economies as a result of air pollution and lack of energy security. One of the main findings of our cost-benefit analysis is that energy security policy alone does not decrease the use of oil: global oil consumption is only delayed by several decades and oil reserves are still practically depleted before the end of the 21st century. If, on the other hand, energy security policy is integrated with optimal climate change and air pollution policy, the world's oil reserves will not be depleted, at least not before our modeling horizon well into the 22nd century: total cumulative demand for oil decreases by about 24%. More generally, we demonstrate that there are multiple other benefits of combining climate change, air pollution, and energy security policies and exploiting the possible synergies between them. These benefits can be large: for Europe the achievable CO 2 emission abatement and oil consumption reduction levels are significantly deeper for integrated policy than when a strategy is adopted in which one of the three policies is omitted. Integrated optimal energy policy can reduce the number of premature deaths from air pollution by about 14,000 annually in Europe and over 3 million per year globally, by lowering the chronic exposure to ambient particulate matter. Only the optimal strategy combining the three types of energy policy can constrain the global average atmospheric temperature increase to a limit of 3 C with respect to the pre-industrial level. (author)

Intercomparative tests on phase change materials characterisation with differential scanning calorimeter

International Nuclear Information System (INIS)

Lazaro, Ana; Peñalosa, Conchita; Solé, Aran; Diarce, Gonzalo; Haussmann, Thomas; Fois, Magali; Zalba, Belén; Gshwander, Stefan; Cabeza, Luisa F.

2013-01-01

Highlights: ► Advances in intercomparative tests of enthalpy of phase change material (PCM). ► Enthalpy of PCM determined by DSC is influenced by certain factors. ► The influence factors were identified. ► A methodology to avoid these influences for heating measurements is proposed. ► Forthcoming steps are focused on calibration and cooling measurements. - Abstract: For the correct design of thermal storage systems using phase change materials (PCMs) in any application, as well as for their simulation, it is essential to characterise the materials from thermophysical and rheological standpoints (phase change enthalpy, thermal conductivity in solid and liquid phases, viscosity and density in function of temperature). Taking advantage of the different research groups facilities available in two international networks: within the IEA (International Energy Agency), the ECES Implementing Agreement (Energy Conservation through Energy Storage IA) and SHC Programme (Solar Heating and Cooling) Task 42/Annex 24 “Compact Thermal Energy Storage – Material Development for System Integration”, and the COST Action TU0802 “Next generation cost effective phase change materials for increased energy efficiency in renewable energy systems in buildings (NeCoE-PCM)” a set of Round Robin Tests (RRTs) was proposed. The objective was to come to comparable results for PCMs using Differential Scanning Calorimetry (DSC) to determine their melting enthalpy as well as their melting and solidification behaviour. The first RRT was without defining the procedure, the second one with a predefined procedure for the measurements, but not for calibration and the third one with a predefined procedure for calibration, for the measurements and also for the data evaluation. This paper presents the conclusions after the three RRT. The main conclusion of the paper is that enthalpy in function of temperature determined using a dynamic method for DSC can be influenced by certain reasons

Glovebox characterization and barrier integrity testing using fluorescent powder

International Nuclear Information System (INIS)

Wahlquist, D.R.

1996-01-01

This paper presents a method for characterizing the spread of contamination and testing the barrier integrity of a new glovebox during material transfer operations and glove change-outs using fluorescent powder. Argonne National Laboratory-West has performed this test on several new gloveboxes prior to putting them into service. The test is performed after the glovebox has been leak tested and all systems have been verified to be operational. The purpose of the test is to show that bag-in/bag-out operations and glove change-outs can be accomplished without spreading the actual contaminated material to non-contaminated areas. The characterization test also provides information as to where contamination might be expected to build-up during actual operations. The fluorescent powder is used because it is easily detectable using an ultra-violet light and disperses in a similar fashion to radioactive material. The characterization and barrier integrity test of a glovebox using fluorescent powder provides a visual method of determining areas of potential contamination accumulation and helps evaluate the ability to perform clean transfer operations and glove change-outs

Generation IV Reactors Integrated Materials Technology Program Plan: Focus on Very High Temperature Reactor Materials

Energy Technology Data Exchange (ETDEWEB)

Corwin, William R [ORNL; Burchell, Timothy D [ORNL; Katoh, Yutai [ORNL; McGreevy, Timothy E [ORNL; Nanstad, Randy K [ORNL; Ren, Weiju [ORNL; Snead, Lance Lewis [ORNL; Wilson, Dane F [ORNL

2008-08-01

the structural materials needed to ensure their safe and reliable operation. The focus of this document will be the overall range of DOE's structural materials research activities being conducted to support VHTR development. By far, the largest portion of material's R&D supporting VHTR development is that being performed directly as part of the Next-Generation Nuclear Plant (NGNP) Project. Supplementary VHTR materials R&D being performed in the DOE program, including university and international research programs and that being performed under direct contracts with the American Society for Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, will also be described. Specific areas of high-priority materials research that will be needed to deploy the NGNP and provide a basis for subsequent VHTRs are described, including the following: (1) Graphite: (a) Extensive unirradiated materials characterization and assessment of irradiation effects on properties must be performed to qualify new grades of graphite for nuclear service, including thermo-physical and mechanical properties and their changes, statistical variations from billot-to-billot and lot-to-lot, creep, and especially, irradiation creep. (b) Predictive models, as well as codification of the requirements and design methods for graphite core supports, must be developed to provide a basis for licensing. (2) Ceramics: Both fibrous and load-bearing ceramics must be qualified for environmental and radiation service as insulating materials. (3) Ceramic Composites: Carbon-carbon and SiC-SiC composites must be qualified for specialized usage in selected high-temperature components, such as core stabilizers, control rods, and insulating covers and ducting. This will require development of component-specific designs and fabrication processes, materials characterization, assessment of environmental and irradiation effects, and establishment of codes and standards for materials testing and design

Enhanced laminated composite phase change material for energy storage

Energy Technology Data Exchange (ETDEWEB)

Darkwa, J.; Zhou, T. [Centre for Sustainable Energy Technologies (CSET), The University of Nottingham Ningbo, 199 Taikang East Road, Ningbo 315100 (China)

2011-02-15

This paper summarises studies undertaken towards the development of a laminated composite aluminium/hexadecane phase change material (PCM) drywall based on previous analytical work. The study also covered the selection and testing of various types of adhesive materials and identified Polyvinyl acetate (PVA) material as a suitable bonding material. For the purpose of comparison pure hexadecane and composite aluminium/hexadecane samples were developed and tested. The test results revealed faster thermal response by the aluminium/hexadecane sample regarding the rate of heat flux and also achieved about 10% and 15% heat transfer enhancements during the charging and discharging periods respectively. Its measured effective thermal conductivity also increased remarkably to 1.25 W/mK as compared with 0.15 W/mK for pure hexadecane. However there was about 5% less total cumulative thermal energy discharged at the end of the test which indicates that its effective thermal capacity was reduced by the presence of the aluminium particles. The study has shown that some of the scientific and technical barriers associated with the development of laminated composite PCM drywall systems can be overcome but further investigations of effects of adhesive materials are needed. (author)

Integrated Life-Cycle Hazardous Material Management: A Logistics Imperative for USAREUR and the 7th Army

National Research Council Canada - National Science Library

Werle, Christopher

2000-01-01

This report examines the benefit to be gained by integrating traditional "pharmacy" business practices in the existing supply system rather than building a parallel system for hazardous material/hazardous waste (HM/HW) management...

Personal cooling with phase change materials to improve thermal comfort from a heat wave perspective.

Science.gov (United States)

Gao, C; Kuklane, K; Wang, F; Holmér, I

2012-12-01

The impact of heat waves arising from climate change on human health is predicted to be profound. It is important to be prepared with various preventive measures for such impacts on society. The objective of this study was to investigate whether personal cooling with phase change materials (PCM) could improve thermal comfort in simulated office work at 34°C. Cooling vests with PCM were measured on a thermal manikin before studies on human subjects. Eight male subjects participated in the study in a climatic chamber (T(a) = 34°C, RH = 60%, and ν(a) = 0.4 m/s). Results showed that the cooling effect on the manikin torso was 29.1 W/m(2) in the isothermal condition. The results on the manikin using a constant heating power mode reflect directly the local cooling effect on subjects. The results on the subjects showed that the torso skin temperature decreased by about 2-3°C and remained at 33.3°C. Both whole body and torso thermal sensations were improved. The findings indicate that the personal cooling with PCM can be used as an option to improve thermal comfort for office workers without air conditioning and may be used for vulnerable groups, such as elderly people, when confronted with heat waves. Wearable personal cooling integrated with phase change materials has the advantage of cooling human body's micro-environment in contrast to stationary personalized cooling and entire room or building cooling, thus providing greater mobility and helping to save energy. In places where air conditioning is not usually used, this personal cooling method can be used as a preventive measure when confronted with heat waves for office workers, vulnerable populations such as the elderly and disabled people, people with chronic diseases, and for use at home. © 2012 John Wiley & Sons A/S.

Heavy oils processing materials requirements crude processing

Energy Technology Data Exchange (ETDEWEB)

Sloley, Andrew W. [CH2M Hill, Englewood, CO (United States)

2012-07-01

Over time, recommended best practices for crude unit materials selection have evolved to accommodate new operating requirements, feed qualities, and product qualities. The shift to heavier oil processing is one of the major changes in crude feed quality occurring over the last 20 years. The three major types of crude unit corrosion include sulfidation attack, naphthenic acid attack, and corrosion resulting from hydrolyzable chlorides. Heavy oils processing makes all three areas worse. Heavy oils have higher sulfur content; higher naphthenic acid content; and are more difficult to desalt, leading to higher chloride corrosion rates. Materials selection involves two major criteria, meeting required safety standards, and optimizing economics of the overall plant. Proper materials selection is only one component of a plant integrity approach. Materials selection cannot eliminate all corrosion. Proper materials selection requires appropriate support from other elements of an integrity protection program. The elements of integrity preservation include: materials selection (type and corrosion allowance); management limits on operating conditions allowed; feed quality control; chemical additives for corrosion reduction; and preventive maintenance and inspection (PMI). The following discussion must be taken in the context of the application of required supporting work in all the other areas. Within that context, specific materials recommendations are made to minimize corrosion due to the most common causes in the crude unit. (author)

Stress and Damage in Polymer Matrix Composite Materials Due to Material Degradation at High Temperatures

Science.gov (United States)

McManus, Hugh L.; Chamis, Christos C.

1996-01-01

This report describes analytical methods for calculating stresses and damage caused by degradation of the matrix constituent in polymer matrix composite materials. Laminate geometry, material properties, and matrix degradation states are specified as functions of position and time. Matrix shrinkage and property changes are modeled as functions of the degradation states. The model is incorporated into an existing composite mechanics computer code. Stresses, strains, and deformations at the laminate, ply, and micro levels are calculated, and from these calculations it is determined if there is failure of any kind. The rationale for the model (based on published experimental work) is presented, its integration into the laminate analysis code is outlined, and example results are given, with comparisons to existing material and structural data. The mechanisms behind the changes in properties and in surface cracking during long-term aging of polyimide matrix composites are clarified. High-temperature-material test methods are also evaluated.

Nurse practitioner integration: Qualitative experiences of the change management process.

Science.gov (United States)

Lowe, Grainne; Plummer, Virginia; Boyd, Leanne

2018-04-30

The aim of this qualitative research was to explore perceptions of organisational change related to the integration of nurse practitioners from key nursing stakeholders. The ongoing delivery of effective and efficient patient services is reliant upon the development and sustainability of nurse practitioner roles. Examination of the factors contributing to the underutilization of nurse practitioner roles is crucial to inform future management policies. A change management theory is used to reveal the complexity involved. Qualitative interviews were undertaken using a purposive sampling strategy of key stakeholders. Thematic analysis was undertaken and key themes were correlated to the theoretical framework. The results confirm the benefits of nurse practitioner roles, but suggest organisational structures and embedded professional cultures present barriers to full role optimization. Complicated policy processes are creating barriers to the integration of nurse practitioner roles. The findings increase understanding of the links between strategic planning, human resource management, professional and organisational cultures, governance and politics in change management. Effective leadership drives the change process through the ability to align key components necessary for success. Sustainability of nurse practitioners relies on recognition of their full potential in the health care team. The results of this study highlight the importance of management and leadership in the promotion of advanced nursing skills and experience to better meet patient outcomes. The findings reinforce the potential of nurse practitioners to deliver patient centred, timely and efficient health care. © 2018 John Wiley & Sons Ltd.

Social Integration and Health Behavioral Change in San Luis, Honduras

Science.gov (United States)

McQuestion, Michael J.; Calle, Ana Quijano; Drasbek, Christopher; Harkins, Thomas; Sagastume, Lourdes J.

2010-01-01

This study explores the effects of social integration on behavioral change in the course of an intensive, community-based public health intervention. The intervention trained volunteers and mobilized local organizations to promote 16 key family health practices in rural San Luis, Honduras, during 2004 to 2006. A mixed methods approach is used.…

National Call for Organizational Change from Sheltered to Integrated Employment

Science.gov (United States)

Rogan, Patricia; Rinne, Susan

2011-01-01

Our purpose in this article is to contend that organizational change from sheltered to integrated employment is not only possible but necessary, and a federal Employment First agenda must be advanced. Findings are reported from interviews with senior managers from 10 organizations that have shifted their service delivery to community employment,…

Integrating Materials, Manufacturing, Design and Validation for Sustainability in Future Transport Systems

International Nuclear Information System (INIS)

Price, M. A.; Murphy, A.; Butterfield, J.; McCool, R.; Fleck, R.

2011-01-01

The predictive methods currently used for material specification, component design and the development of manufacturing processes, need to evolve beyond the current 'metal centric' state of the art, if advanced composites are to realise their potential in delivering sustainable transport solutions. There are however, significant technical challenges associated with this process. Deteriorating environmental, political, economic and social conditions across the globe have resulted in unprecedented pressures to improve the operational efficiency of the manufacturing sector generally and to change perceptions regarding the environmental credentials of transport systems in particular. There is a need to apply new technologies and develop new capabilities to ensure commercial sustainability in the face of twenty first century economic and climatic conditions as well as transport market demands. A major technology gap exists between design, analysis and manufacturing processes in both the OEMs, and the smaller companies that make up the SME based supply chain. As regulatory requirements align with environmental needs, manufacturers are increasingly responsible for the broader lifecycle aspects of vehicle performance. These include not only manufacture and supply but disposal and re-use or re-cycling. In order to make advances in the reduction of emissions coupled with improved economic efficiency through the provision of advanced lightweight vehicles, four key challenges are identified as follows: Material systems, Manufacturing systems, Integrated design methods using digital manufacturing tools and Validation systems. This paper presents a project which has been designed to address these four key issues, using at its core, a digital framework for the creation and management of key parameters related to the lifecycle performance of thermoplastic composite parts and structures. It aims to provide capability for the proposition, definition, evaluation and demonstration of

Integrating Materials, Manufacturing, Design and Validation for Sustainability in Future Transport Systems

Science.gov (United States)

Price, M. A.; Murphy, A.; Butterfield, J.; McCool, R.; Fleck, R.

2011-05-01

The predictive methods currently used for material specification, component design and the development of manufacturing processes, need to evolve beyond the current `metal centric' state of the art, if advanced composites are to realise their potential in delivering sustainable transport solutions. There are however, significant technical challenges associated with this process. Deteriorating environmental, political, economic and social conditions across the globe have resulted in unprecedented pressures to improve the operational efficiency of the manufacturing sector generally and to change perceptions regarding the environmental credentials of transport systems in particular. There is a need to apply new technologies and develop new capabilities to ensure commercial sustainability in the face of twenty first century economic and climatic conditions as well as transport market demands. A major technology gap exists between design, analysis and manufacturing processes in both the OEMs, and the smaller companies that make up the SME based supply chain. As regulatory requirements align with environmental needs, manufacturers are increasingly responsible for the broader lifecycle aspects of vehicle performance. These include not only manufacture and supply but disposal and re-use or re-cycling. In order to make advances in the reduction of emissions coupled with improved economic efficiency through the provision of advanced lightweight vehicles, four key challenges are identified as follows: Material systems, Manufacturing systems, Integrated design methods using digital manufacturing tools and Validation systems. This paper presents a project which has been designed to address these four key issues, using at its core, a digital framework for the creation and management of key parameters related to the lifecycle performance of thermoplastic composite parts and structures. It aims to provide capability for the proposition, definition, evaluation and demonstration of

Controllable biomimetic adhesion using embedded phase change material

International Nuclear Information System (INIS)

Krahn, J; Sameoto, D; Menon, C

2011-01-01

In many cases, such as in the instance of climbing robots or temporary adhesives, there is the need to be able to dynamically control the level of adhesion a biomimetic dry adhesive can provide. In this study, the effect of changing the backing layer stiffness of a dry adhesive is examined. Embedding a phase change material within the backing of a synthetic dry adhesive sheet allows the stiffness to be tailored at different points of a preload and adhesion cycle. Larger contact areas and more equal load sharing between adhesive fibres can be achieved by increasing the backing layer stiffness after initial deformation when the adhesive backing is loaded in its softened state. Adhesion behaviour is examined when the backing layer is maintained in solid and softened phases during complete load cycles and for load cycles under the condition of contact with the softened phase backing followed by pull-off during the solid phase. Absolute adhesion force is increased for trials in which a soft backing layer hardens prior to pull-off. This effect is due to the increased contact area made between the rounded probe and the softened material during preloading and the more equal load sharing condition during pull-off when the backing layer becomes stiff again

Phase field modeling of rapid crystallization in the phase-change material AIST

Science.gov (United States)

Tabatabaei, Fatemeh; Boussinot, Guillaume; Spatschek, Robert; Brener, Efim A.; Apel, Markus

2017-07-01

We carry out phase field modeling as a continuum simulation technique in order to study rapid crystallization processes in the phase-change material AIST (Ag4In3Sb67Te26). In particular, we simulate the spatio-temporal evolution of the crystallization of a molten area of the phase-change material embedded in a layer stack. The simulation model is adapted to the experimental conditions used for recent measurements of crystallization rates by a laser pulse technique. Simulations are performed for substrate temperatures close to the melting temperature of AIST down to low temperatures when an amorphous state is involved. The design of the phase field model using the thin interface limit allows us to retrieve the two limiting regimes of interface controlled (low temperatures) and thermal transport controlled (high temperatures) dynamics. Our simulations show that, generically, the crystallization velocity presents a maximum in the intermediate regime where both the interface mobility and the thermal transport, through the molten area as well as through the layer stack, are important. Simulations reveal the complex interplay of all different contributions. This suggests that the maximum switching velocity depends not only on material properties but also on the precise design of the thin film structure into which the phase-change material is embedded.

Heat transfer characteristics of coconut oil as phase change material to room cooling application

Science.gov (United States)

Irsyad, M.; Harmen

2017-03-01

Thermal comfort in a room is one of human needs in the workplace and dwellings, so that the use of air conditioning system in tropical countries is inevitable. This equipment has an impact on the increase of energy consumption. One method of minimizing the energy use is by using the phase change material (PCM) as thermal energy storage. This material utilizes the temperature difference between day and night for the storage and release of thermal energy. PCM development on application as a material for air cooling inlet, partitioning and interior needs to be supported by the study of heat transfer characteristics when PCM absorbs heat from ambient temperature. This study was conducted to determine the heat transfer characteristics on coconut oil as a phase change material. There are three models of experiments performed in this research. Firstly, an experiment was conducted to analyze the time that was needed by material to phase change by varying the temperature. The second experiment analyzed the heat transfer characteristics of air to PCM naturally convection. The third experiment analyzed the forced convection heat transfer on the surface of the PCM container by varying the air velocity. The data of experimental showed that, increasing ambient air temperature resulted in shorter time for phase change. At temperatures of 30°C, the time for phase change of PCM with the thickness of 8 cm was 1700 min, and it was stable at temperatures of 27°C. Increasing air temperature accelerated the phase change in the material. While for the forced convection heat transfer, PCM could reduce the air temperature in the range of 30 to 35°C at about 1 to 2°C, with a velocity of 1-3 m/s.

A review on phase-change materials: Mathematical modeling and simulations

International Nuclear Information System (INIS)

Dutil, Yvan; Rousse, Daniel R.; Salah, Nizar Ben; Lassue, Stephane; Zalewski, Laurent

2011-01-01

Energy storage components improve the energy efficiency of systems by reducing the mismatch between supply and demand. For this purpose, phase-change materials are particularly attractive since they provide a high-energy storage density at a constant temperature which corresponds to the phase transition temperature of the material. Nevertheless, the incorporation of phase-change materials (PCMs) in a particular application calls for an analysis that will enable the researcher to optimize performances of systems. Due to the non-linear nature of the problem, numerical analysis is generally required to obtain appropriate solutions for the thermal behavior of systems. Therefore, a large amount of research has been carried out on PCMs behavior predictions. The review will present models based on the first law and on the second law of thermodynamics. It shows selected results for several configurations, from numerous authors so as to enable one to start his/her research with an exhaustive overview of the subject. This overview stresses the need to match experimental investigations with recent numerical analyses since in recent years, models mostly rely on other models in their validation stages. (author)

A phenomenological approach of solidification of polymeric phase change materials

Science.gov (United States)

Bahrani, Seyed Amir; Royon, Laurent; Abou, Bérengère; Osipian, Rémy; Azzouz, Kamel; Bontemps, André

2017-01-01

Phase Change Materials (PCMs) are widely used in thermal energy storage and thermal management systems due to their small volume for a given stored energy and their capability for maintaining nearly constant temperatures. However, their performance is limited by their low thermal conductivity and possible leaks while in the liquid phase. One solution is to imprison the PCM inside a polymer mesh to create a Polymeric Phase Change Material (PPCM). In this work, we have studied the cooling and solidification of five PPCMs with different PCMs and polymer fractions. To understand the heat transfer mechanisms involved, we have carried out micro- and macrorheological measurements in which Brownian motion of tracers embedded in PPCMs has been depicted and viscoelastic moduli have been measured, respectively. Beyond a given polymer concentration, it was shown that the Brownian motion of the tracers is limited by the polymeric chains and that the material exhibits an elastic behavior. This would suggest that heat transfer essentially occurs by conduction, instead of convection. Experiments were conducted to measure temperature variation during cooling of the five samples, and a semi-empirical model based on a phenomenological approach was proposed as a practical tool to choose and size PPCMs.

Proceedings of the international workshop on aged and decommissioned material collection and testing for structural integrity purposes

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-07-01

This workshop was sponsored by the CEC DG XI and XII/JRC Petten/AMES and by the Principal Working Group 3 (PWG-3) on reactor component integrity of the NEA CSNI, and it was hosted by the CEN Mol, Belgium. The activities of PWG-3 fall into three main areas: non-destructive examination (NDE), fracture analysis, and ageing/materials degradation. The topic of the workshop falls into the third area of ageing and materials degradation. The titles of the papers are: AMES and other European networks in Integrity of Ageing Structures; Over View of Proving Test on the Reliability of Material of Nuclear Power Plant Components; Activities on Ageing Degradation Phenomena of NPP in Korea; Capability of Investigation on Decommissioned Parts from NPPs at the MPA Stuttgart; How Accurately can Surveillance Specimens Reflect the True State of RPV Materials?; Applicability of Design Codes to Aged Materials; Microstructural Investigations of as-Fabricated, Long-Term Thermally Aged and Neutron Irradiated RPV Materials: An Atom Probe Study; Proposed Post-Service Investigations on Decommissioned Greifswald Units; Tools and Experience in Post Irradiation Examination of Structural Core Components at PSI Hot laboratory; Testing of Beznau NPP Unit 1 Steam Generator Cast Stainless Steel Elbows; Mechanical Properties Characterisation of Irradiated Materials From Operating or Decommissioned Nuclear Power Plants; Long Term Ageing of Cast Ti-Stabilised Stainless Steel; Enhanced Surveillance of Nuclear Reactor Pressure Vessels. Discussions and conclusions are also presented

Graphene-enhanced hybrid phase change materials for thermal management of Li-ion batteries

Science.gov (United States)

Goli, Pradyumna; Legedza, Stanislav; Dhar, Aditya; Salgado, Ruben; Renteria, Jacqueline; Balandin, Alexander A.

2014-02-01

Li-ion batteries are crucial components for progress in mobile communications and transport technologies. However, Li-ion batteries suffer from strong self-heating, which limits their life-time and creates reliability and environmental problems. Here we show that thermal management and the reliability of Li-ion batteries can be drastically improved using hybrid phase change material with graphene fillers. Conventional thermal management of batteries relies on the latent heat stored in the phase change material as its phase changes over a small temperature range, thereby reducing the temperature rise inside the battery. Incorporation of graphene to the hydrocarbon-based phase change material allows one to increase its thermal conductivity by more than two orders of magnitude while preserving its latent heat storage ability. A combination of the sensible and latent heat storage together with the improved heat conduction outside of the battery pack leads to a significant decrease in the temperature rise inside a typical Li-ion battery pack. The described combined heat storage-heat conduction approach can lead to a transformative change in thermal management of Li-ion and other types of batteries.

Applications of graphite-enabled phase change material composites to improve thermal performance of cementitious materials

Science.gov (United States)

Li, Mingli; Lin, Zhibin; Wu, Lili; Wang, Jinhui; Gong, Na

2017-11-01

Enhancing the thermal efficiency to decrease the energy consumption of structures has been the topic of much research. In this study, a graphite-enabled microencapsulated phase change material (GE-MEPCM) was used in the production of a novel thermal energy storage engineered cementitious composite feathering high heat storage capacity and enhanced thermal conductivity. The surface morphology and particle size of the microencapsulated phase change material (MEPCM) were investigated by scanning electron microscopy (SEM). Thermal properties of MEPCM was determined using differential scanning calorimetry (DSC). In addition, thermal and mechanical properties of the cementitious mortar with different admixtures were explored and compared with those of a cementitious composite. It was shown that the latent heat of MEPCM was 162 J/g, offering much better thermal energy storage capacity to the cementitious composite. However, MEPCM was found to decrease the thermal conductivity of the composite, which can be effectively solved by adding natural graphite (NG). Moreover, the incorporation of MEPCM has a certain decrease in the compressive strength, mainly due to the weak interfaces between MEPCM and cement matrix.

Speci﬿c contact resistance of phase change materials to metal electrode

NARCIS (Netherlands)

Roy, Deepu; in 't Zandt, Micha A.A.; Wolters, Robertus A.M.

2010-01-01

For phase change random access memory (PCRAM) cells, it is important to know the contact resistance of phase change materials (PCMs) to metal electrodes at the contacts. In this letter, we report the systematic determination of the speci﬿c contact resistance (Ͽc ) of doped Sb2Te and Ge2Sb2Te5 to TiW

Examination of a Size-Change Test for Photovoltaic Encapsulation Materials: Preprint

Energy Technology Data Exchange (ETDEWEB)

Miller, D. C.; Wohlgemuth, J. H.; Gu, X.; Ji, L.; Kelly, G.; Gu, X.; Nickel, N.; Norum, P.; Shioda, T.; Tamizhmani, G.

2012-08-01

We examine a proposed test standard that can be used to evaluate the maximum representative change in linear dimensions of sheet encapsulation products for photovoltaic modules (resulting from their thermal processing). The proposed protocol is part of a series of material-level tests being developed within Working Group 2 of the Technical Committee 82 of the International Electrotechnical Commission. The characterization tests are being developed to aid module design (by identifying the essential characteristics that should be communicated on a datasheet), quality control (via internal material acceptance and process control), and failure analysis. Discovery and interlaboratory experiments were used to select particular parameters for the size-change test. The choice of a sand substrate and aluminum carrier is explored relative to other options. The temperature uniformity of +/- 5C for the substrate was confirmed using thermography. Considerations related to the heating device (hot-plate or oven) are explored. The time duration of 5 minutes was identified from the time-series photographic characterization of material specimens (EVA, ionomer, PVB, TPO, and TPU). The test procedure was revised to account for observed effects of size and edges. The interlaboratory study identified typical size-change characteristics, and also verified the absolute reproducibility of +/- 5% between laboratories.

Integrated modelling of material migration and target plate power handling at JET

International Nuclear Information System (INIS)

Coster, D.P.; Bonnin, X.; Chankin, A.

2005-01-01

The complexity of the tokamak edge and scrape-off layer (SOL) region is such that extrapolation to ITER requires modelling to be pursued through the integration of a number of edge codes, each of which must be thoroughly tested against results from present day machines. This contribution demonstrates how the edge modelling effort at JET is focused on such an approach by considering two examples, target power loading and material erosion and migration, the understanding of which are crucial issues for ITER. (author)

Project Management Plan for Material Stabilization

International Nuclear Information System (INIS)

SPEER, D.R.

1999-01-01

This plan presents the overall objectives, description, justification and planning for the plutonium Finishing Plant (PFP) Materials Stabilization project. The intent of this plan is to describe how this project will be managed and integrated with other facility stabilization and deactivation activities. This plan supplements the overall integrated plan presented in the Plutonium Finishing Plant Integrated Project Management Plan (IPMP), HNF-3617/Rev. 0. This is the top-level definitive project management document that specifies the technical (work scope), schedule, and cost baselines to manager the execution of this project. It describes the organizational approach and roles/responsibilities to be implemented to execute the project. This plan is under configuration management and any deviations must be authorized by appropriate change control action. Materials stabilization is designated the responsibility to open and stabilize containers of plutonium metal, oxides, alloys, compounds, and sources. Each of these items is at least 30 weight percent plutonium/uranium. The output of this project will be containers of materials in a safe and stable form suitable for storage pending final packaging and/or transportation offsite. The corrosion products along with oxides and compounds will be stabilized via muffle furnaces to reduce the materials to high fired oxides

A Modular Approach to Integrating Biofuels Education into ChE Curriculum Part I--Learning Materials

Science.gov (United States)

He, Q. Peter; Wang, Jin; Zhang, Rong; Johnson, Donald; Knight, Andrew; Polala, Ravali

2016-01-01

In view of potential demand for skilled engineers and competent researchers in the biofuels field, we have identified a significant gap between advanced biofuels research and undergraduate biofuels education in chemical engineering. To help bridge this gap, we created educational materials that systematically integrate biofuels technologies into…

Aluminum and silicon based phase change materials for high capacity thermal energy storage

International Nuclear Information System (INIS)

Wang, Zhengyun; Wang, Hui; Li, Xiaobo; Wang, Dezhi; Zhang, Qinyong; Chen, Gang; Ren, Zhifeng

2015-01-01

Six compositions of aluminum (Al) and silicon (Si) based materials: 87.8Al-12.2Si, 80Al–20Si, 70Al–30Si, 60Al–40Si, 45Al–40Si–15Fe, and 17Al–53Si–30Ni (atomic ratio), were investigated for potentially high thermal energy storage (TES) application from medium to high temperatures (550–1200 °C) through solid–liquid phase change. Thermal properties such as melting point, latent heat, specific heat, thermal diffusivity and thermal conductivity were investigated by differential scanning calorimetry and laser flash apparatus. The results reveal that the thermal storage capacity of the Al–Si materials increases with increasing Si concentration. The melting point and latent heat of 45Al–40Si–15Fe and 17Al–53Si–30Ni are ∼869 °C and ∼562 J g −1 , and ∼1079 °C and ∼960 J g −1 , respectively. The measured thermal conductivity of Al–Si binary materials depend on Si concentration and is higher than 80 W m −1  K −1 from room temperature to 500 °C, which is almost two orders of magnitude higher than those of salts that are commonly used phase change material for thermal energy storage. - Highlights: • Six kinds of materials were investigated for thermal energy storage (550–1200 °C). • Partial melting of Al–Si materials show progressively changing temperatures. • Studied materials can be used in three different working temperature ranges. • Materials are potentially good candidates for thermal energy storage applications.

Development of Integrated Natural Science Teaching Materials Webbed Type with Applying Discourse Analysis on Students Grade VIII in Physics Class

Science.gov (United States)

Sukariasih, Luh

2017-05-01

This study aims to produce teaching materials integrated natural science (IPA) webbed type of handout types are eligible for use in integrated science teaching. This type of research IS a kind of research and development / Research and Development (R & D) with reference to the 4D development model that is (define, design, develop, and disseminate). Data analysis techniques used to process data from the results of the assessment by the validator expert, and the results of the assessment by teachers and learners while testing is limited (12 students of class VIII SMPN 10 Kendari) using quantitative descriptive data analysis techniques disclosed in the distribution of scores on the scale of five categories grading scale that has been determined. The results of due diligence material gain votes validator material in the category of “very good” and “good”, of the data generated in the feasibility test presentation obtained the category of “good” and “excellent”, from the data generated in the feasibility of graphic test obtained the category of “very good “and” good “, as well as of the data generated in the test the feasibility of using words and language obtained the category of“very good “and” good “, so with qualifications gained the teaching materials IPA integrated type webbed by applying discourse analysis on the theme of energy and food for Junior High School (SMP) grade VIII suitable as teaching materials. In limited testing, data generated in response to a science teacher at SMPN 10 Kendari to product instructional materials as “excellent”, and from the data generated while testing is limited by the 12 students of class VIII SMPN 10 Kendari are more students who score indicates category “very good”, so that the qualification obtained by the natural science (IPA) teaching material integrated type webbed by applying discourse analysis on the theme of energy and food for SMP / class VIII fit for use as teaching material.

Non-Toxic, Non-Flammable, -80 C Phase Change Materials

Science.gov (United States)

Cutbirth, J. Michael

2013-01-01

The objective of this effort was to develop a non-toxic, non-flammable, -80 C phase change material (PCM) to be used in NASA's ICEPAC capsules for biological sample preservation in flight to and from Earth orbit. A temperature of about -68 C or lower is a critical temperature for maintaining stable cell, tissue, and cell fragment storage.

A modified moment-fitted integration scheme for X-FEM applications with history-dependent material data

Science.gov (United States)

Zhang, Ziyu; Jiang, Wen; Dolbow, John E.; Spencer, Benjamin W.

2018-01-01

We present a strategy for the numerical integration of partial elements with the eXtended finite element method (X-FEM). The new strategy is specifically designed for problems with propagating cracks through a bulk material that exhibits inelasticity. Following a standard approach with the X-FEM, as the crack propagates new partial elements are created. We examine quadrature rules that have sufficient accuracy to calculate stiffness matrices regardless of the orientation of the crack with respect to the element. This permits the number of integration points within elements to remain constant as a crack propagates, and for state data to be easily transferred between successive discretizations. In order to maintain weights that are strictly positive, we propose an approach that blends moment-fitted weights with volume-fraction based weights. To demonstrate the efficacy of this simple approach, we present results from numerical tests and examples with both elastic and plastic material response.

Study of Phase Change Materials Applied to CPV Receivers

Directory of Open Access Journals (Sweden)

Zun-Hao Shih

2015-01-01

Full Text Available There are lots of factors which can directly affect output efficiency of photovoltaic device. One of them is high temperature which would cause adverse effect to solar cell. When solar cell is operated in high temperature, the cell’s output efficiency will become low. Therefore, improving thermal spreading of solar cell is an important issue. In this study, we focused on finding new materials to enhance the thermal dispreading and keep the temperature of solar cell as low as possible. The new materials are different from conventional metal ones; they are called “phase change materials (PCMs” which are mainly applied to green buildings. We chose two kinds of PSMs to study their thermal dispreading ability and to compare them with traditional aluminum material. These two kinds of PCMs are wax and lauric acid. We made three aluminum-based cuboids as heat sinking units and two of them were designed with hollow space to fill in the PCMs. We applied electric forward bias on solar cells to simulate the heat contributed from the concentrated sunlight. Then we observed the thermal distribution of these three kinds of thermal spreading materials. Two levels of forward biases were chosen to test the samples and analyze the experiment results.

2006/07 Field Testing of Cellulose Fiber Insulation Enhanced with Phase Change Material

Energy Technology Data Exchange (ETDEWEB)

Kosny, Jan [ORNL; Yarbrough, David W [ORNL; Miller, William A [ORNL; Petrie, Thomas [ORNL; Childs, Phillip W [ORNL; Syed, Azam M [ORNL

2008-12-01

Most recent improvements in building envelope technologies suggest that in the near future, residences will be routinely constructed to operate with very low heating and cooling loads. In that light, the application of novel building materials containing active thermal components (e.g., phase change materials [PCMs,] sub-venting, radiant barriers, and integrated hydronic systems) is like a final step in achieving relatively significant heating and cooling energy savings from technological improvements in the building envelope. It is expected that optimized building envelope designs using PCMs for energy storage can effectively bring notable savings in energy consumption and reductions in peak hour power loads. During 2006/07, a research team at Oak Ridge National Laboratory (ORNL) performed a series of laboratory and field tests of several wall and roof assemblies using PCM-enhanced cellulose insulation. This report summarizes the test results from the perspective of energy performance. The ORNL team is working on both inorganic and organic PCMs; this report discusses only paraffinic PCMs. A limited economical analysis also is presented. PCMs have been tested as a thermal mass component in buildings for at least 40 years. Most of the research studies found that PCMs enhanced building energy performance. In the case of the application of organic PCMs, problems such as high initial cost and PCM leaking (surface sweating) have hampered widespread adoption. Paraffinic hydrocarbon PCMs generally performed well, with the exception that they increased the flammability of the building envelope.

Electrical transport in crystalline phase change materials

Energy Technology Data Exchange (ETDEWEB)

Woda, Michael

2012-01-06

In this thesis, the electrical transport properties of crystalline phase change materials are discussed. Phase change materials (PCM) are a special class of semiconducting and metallic thin film alloys, typically with a high amount of the group five element antimony or the group six element tellurium, such as Ge{sub 2}Sb{sub 2}Te{sub 5}. The unique property portfolio of this material class makes it suitable for memory applications. PCMs reveal fast switching between two stable room-temperature phases (amorphous and crystalline) realized by optical laser or electrical current pulses in memory devices. Additionally, a pronounced property contrast in form of optical reflectivity and electrical conductivity between the amorphous and crystalline phase is the characteristic fingerprint of PCMs. The emerging electrical solid state memory PCRAM is a very promising candidate to replace Flash memory in the near future or to even become a universal memory, which is non-volatile and shows the speed and cyclability of DRAM. One of the main technological challenges is the switching process into the amorphous state, which is the most power demanding step. In order to reduce the switching power, the crystalline resistivity needs to be increased at a given voltage. Thus understanding and tayloring of this property is mandatory. In this work, first the technological relevance, i.e. optical and electrical memory concepts based on PCMs are introduced. Subsequently a description of the physical properties of PCMs in four categories is given. Namely, structure, kinetics, optical properties and electrical properties are discussed. Then important recent developments such as the identification of resonant bonding in crystalline PCMs and a property predicting coordination scheme are briefly reviewed. The following chapter deals with the theoretical background of electrical transport, while the next chapter introduces the experimental techniques: Sputtering, XRR, XRD, DSC, thermal annealing

Bias dependent specic contact resistance of phase change material to metal contacts

NARCIS (Netherlands)

Roy, Deepu; in 't Zandt, Micha; Wolters, Robertus A.M.

2010-01-01

Knowledge of contact resistance of phase change materials (PCM) to metal electrodes is important for scaling, device modeling and optimization of phase change random access memory (PCRAM) cells. In this article, we report the systematic determination of the speci_c contact resistance (_c) with

Fabrication and characterization of nanofiber-nanoparticle-composites with phase change materials by electrospinning

International Nuclear Information System (INIS)

Babapoor, Aziz; Karimi, Gholamreza; Khorram, Mohammad

2016-01-01

Highlights: • Form-stable nanofibers with phase change material are produced by electrospinning. • PA6 and PEG are used as the supporting matrix and phase change material. • Various nanoparticles are used to enhance thermal properties of the fibers. • The nanofiber-nanoparticle composites exhibited desirable thermal stability. • Al 2 O 3 nanoparticles improved thermal conductivity of the composites considerably. - Graphical Abstract: Display Omitted - Abstract: Thermal energy storage has been recognized as one of the most important technologies for the utilization of renewable energy sources and conserving energy. In this investigation, through combination of polyethylene glycol (PEG) as a phase change material (PCM), polyamid6 (PA6) and various nanoparticles (SiO 2 , Al 2 O 3 , Fe 2 O 3 and ZnO) as supporting materials, novel form-stable PCMs-based composites were fabricated by single nozzle electrospinning. The structure, morphology and thermal properties of the prepared nanofiber-nanocomposite-enhanced phase change materials (NEPCMs) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and differential scanning calorimeter, respectively. Based on the results, nanocomposites-nanofibers were successfully fabricated with high thermal stability and reliability. It is observed that in all composites, the fiber diameter is decreased by increasing the nanoparticles loading. The lowest average diameter obtained was for Fe 2 O 3 composite. Al 2 O 3 composite showed the maximum thermal conductivity enhancement. This study suggests that the fabricated nanocomposite-PCMs offer proper phase transition temperature range and high heat enthalpy values and hence, have potential for thermal energy storage applications.

Microencapsulated Phase-Change Materials For Storage Of Heat

Science.gov (United States)

Colvin, David P.

1989-01-01

Report describes research on engineering issues related to storage and transport of heat in slurries containing phase-change materials in microscopic capsules. Specific goal of project to develop lightweight, compact, heat-management systems used safely in inhabited areas of spacecraft. Further development of obvious potential of technology expected to lead to commercialization and use in aircraft, electronic equipment, machinery, industrial processes, and other sytems in which requirements for management of heat compete with severe restrictions on weight or volume.

Pitch-based carbon foam heat sink with phase change material

Science.gov (United States)

Klett, James W.; Burchell, Timothy D.

2004-08-24

A process for producing a carbon foam heat sink is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications. The foam is encased and filled with a phase change material to provide a very efficient heat sink device.