Summary of session 3 on synchrotron radiation and beam dynamics (open access)

Summary of session 3 on synchrotron radiation and beam dynamics

We summarize presentations, discussions and general conclusions of the Workshop session on 'Beam Dynamics Issues'. Major subjects include effects due to synchrotron radiation (SR), cryogenic loads, electron cloud, impedances, intra-beam scattering (IBS) and beam-beam interactions.
Date: December 1, 2010
Creator: Shiltsev, V. & Metral, E.
System: The UNT Digital Library
Tevatron QCD for Cosmic-Rays (open access)

Tevatron QCD for Cosmic-Rays

The two multi-purpose experiments D0 and CDF are operated at the Tevatron collider, where proton anti-proton collisions take place at a centre of mass energy of 1.96 TeV in Run II. In the kinematic plane of Q{sup 2}-scale and (anti-)proton momentum fraction x, Tevatron jet measurements cover a wide range, with phase space regions in common and beyond the HERA ep-collider reach. The kinematic limit of the Auger experiment is given by a centre of mass energy of 100 TeV. Cosmic rays cover a large region of the kinematic phase space at low momenta x, corresponding to forward proton/diffractive physics and also at low scales, corresponding to the hadronization scale and the underlying event. Therefore of particular interest are exclusive and diffractive measurements as well as underlying event, double parton scattering and minimum bias measurements. The kinematic limit of the Tevatron corresponds to the PeV energy region below the knee of the differential cosmic particle flux energy distribution. The data discussed here are in general corrected for detector effects, such as efficiency and acceptance. Therefore they can be used directly for testing and improving existing event generators and any future calculations/models. Comparisons take place at the hadronic final state (particle …
Date: December 1, 2010
Creator: Sonnenschein, Lars & U., /RWTH Aachen
System: The UNT Digital Library
CP violation in the D0 -> pi+ pi- decay at CDF (open access)

CP violation in the D0 -> pi+ pi- decay at CDF

We report a measurement of the CP violating asymmetry in D{sup 0} {yields} {pi}{sup +}{pi}{sup -} decays using approximately 215,000 decays reconstructed in about 5.94 fb{sup -1} of CDF data. We use the strong D*{sup +} {yields} D{sup 0}{pi}{sup +} decay ('D* tag') to identify the flavor of the charmed meson at production time and exploit CP-conserving strong c{bar c} pair-production in p{bar p} collisions. Higher statistic samples of Cabibbo-favored D{sup 0} {yields} K{sup -}{pi}{sup +} decays with and without D* tag are used to highly suppress systematic uncertainties due to detector effects. The result, A{sub CP}(D{sup 0} {yields} {pi}{sup +}{pi}{sup -}) = [0.22 {+-} 0.24 (stat.) {+-} 0.11 (syst.)]%, is the world's most precise measurement to date and it is fully consistent with no CP violation.
Date: December 1, 2010
Creator: Morello, Michael Joseph
System: The UNT Digital Library
New Measurement of the Bs Mixing Phase at CDF (open access)

New Measurement of the Bs Mixing Phase at CDF

The CDF collaboration presents an updated measurement of the CP-violating parameter {beta}{sub s}{sup J/{Psi}{phi}} and of the decay width difference {Delta}{Lambda}{sub s} using approximately 6500 B{sub s} {yields} J/{Psi}{phi} decays collected by the dimuon trigger and reconstructed in a data sample corresponding to 5.2 fb{sup -1} of integrated luminosity. Besides exploiting the two-fold increase in the data sample with respect to the previous measurement, several improvements have been introduced in the analysis including a fully data-driven flavor tagging calibration and proper treatment of possible S-wave contributions. We find that the CP-violating phase is within the range {beta}{sub s}{sup J/{Psi}{phi}} {element_of} [0.02, 0.52] {union} [1.08, 1.55] at 68% C.L. The decay width difference is found to be {Delta}{Lambda}{sub s} = 0.075 {+-} 0.035 (stat) {+-} 0.01 (syst) ps{sup -1}. In addition, we present the most precise mean B{sub s} lifetime {tau}{sub s}, polarization amplitudes |A{sub 0}|{sup 2},|A{sub {parallel}}|{sup 2} and |A{sub {perpendicular}}|{sup 2}, as well as strong phase {delta}{sub {perpendicular}}: {tau}{sub s} = 458.6 {+-} 7.6(stat) {+-} 3.6(syst) {micro}m; |A{sub 0}|{sup 2} = 0.524 {+-} 0.013(stat) {+-} 0.015(syst); |A{sub {parallel}}|{sup 2} = 0.231 {+-} 0.014(stat) {+-} 0.015(syst); and {delta}{sub {perpendicular}} = 2.95 {+-} 0.64(stat) {+-} 0.07(syst).
Date: December 1, 2010
Creator: Giurgiu, Gavril
System: The UNT Digital Library
Resonant Vibrations Resulting from the Re-Engineering of a Constant-Speed 2-Bladed Turbine to a Variable-Speed 3-Bladed Turbine (open access)

Resonant Vibrations Resulting from the Re-Engineering of a Constant-Speed 2-Bladed Turbine to a Variable-Speed 3-Bladed Turbine

The CART3 (Controls Advanced Research Turbine, 3-bladed) at the National Wind Technology Center has recently been converted from a 2-bladed constant speed machine to a 3-bladed variable speed machine designed specically for controls research. The purpose of this conversion was to develop an advanced controls field-testing platform which has the more typical 3-bladed configuration. A result of this conversion was the emergence of several resonant vibrations, some of which initially prevented operation of the turbine until they could be explained and resolved. In this paper, the investigations into these vibrations are presented as 'lessons-learned'. Additionally, a frequency-domain technique called waterfall plotting is discussed and its usefulness in this research is illustrated.
Date: December 1, 2010
Creator: Fleming, P.; Wright, A. D. & Finersh, L. J.
System: The UNT Digital Library
Charmless and Penguin Decays at CDF (open access)

Charmless and Penguin Decays at CDF

Penguin transitions play a key role in the search of New Physics hints in the heavy flavor sector. During the last decade CDF has been exploring this opportunity with a rich study of two-body charmless decays of neutral B mesons into charged final-state particles. After briefly introducing the aspects of this physics peculiar to the hadron collision environment, I report on two interesting results: the first polarization measurement of the B{sub s}{sup 0} {yields} {phi}{phi} decay and the update of the B{sub (s)}{sup 0} {yields} h{sup +}h{prime}{sup -} decays analysis.
Date: December 1, 2010
Creator: Dorigo, Mirco & Collaboration, for the CDF
System: The UNT Digital Library
First Experiences with LHC Grid Computing and Distributed Analysis (open access)

First Experiences with LHC Grid Computing and Distributed Analysis

In this presentation the experiences of the LHC experiments using grid computing were presented with a focus on experience with distributed analysis. After many years of development, preparation, exercises, and validation the LHC (Large Hadron Collider) experiments are in operations. The computing infrastructure has been heavily utilized in the first 6 months of data collection. The general experience of exploiting the grid infrastructure for organized processing and preparation is described, as well as the successes employing the infrastructure for distributed analysis. At the end the expected evolution and future plans are outlined.
Date: December 1, 2010
Creator: Fisk, Ian
System: The UNT Digital Library
Vehicle to Micro-Grid: Leveraging Existing Assets for Reliable Energy Management (Poster) (open access)

Vehicle to Micro-Grid: Leveraging Existing Assets for Reliable Energy Management (Poster)

Fort Carson, a United States Army installation located south of Colorado Springs, Colorado, is seeking to be a net-zero energy facility. As part of this initiative, the base will be constructing a micro-grid that ties to various forms of renewable energy. To reduce petroleum consumption, Fort Carson is considering grid-connected vehicles (GCVs) such as pure electric trucks to replace some of its on-base truck fleet. As the availability and affordability of distributed renewable energy generation options increase, so will the GCV options (currently, three all-electric trucks are available on the GSA schedule). The presence of GCVs on-base opens up the possibility to utilize these vehicles to provide stability to the base micro-grid. This poster summarizes work to estimate the potential impacts of three electric vehicle grid interactions between the electric truck fleet and the Fort Carson micro-grid: 1) full-power charging without management, 2) full-power charging capability controlled by the local grid authority, and 3) full-power charge and discharge capability controlled by the local grid authority. We found that even at relatively small adoption rates, the control of electric vehicle charging at Fort Carson will aid in regulation of variable renewable generation loads and help stabilize the micro-grid.
Date: December 1, 2010
Creator: Simpson, M.; Markel, T. & O'Keefe, M.
System: The UNT Digital Library
3HE RECOVERY FROM A TRITIUM-AGED LANA75 SAMPLE (open access)

3HE RECOVERY FROM A TRITIUM-AGED LANA75 SAMPLE

{sup 3}He recovery is a topic of recent interest. One potential recovery source is from metal hydride materials once used to store tritium, as the decay product, {sup 3}He, is primarily trapped in the metal lattice, usually in bubbles, with such materials. In 2001, a Tritium Exposure Program (TEP) sample known as LANA75-SP1 was retired and the material was removed from the test cell and stored. Subsequently scoping temperature programmed desorption (TPD) experiments were conducted on that material to see what it might take to drive out He and residual H isotopes (the heel). Two experiments consisted of heating the sample in the presence of an excess of tin (the so-called Sn fusion experiment), and one was a simple TPD with no additives. Prior data on the so-called '21-month bed' material in the 1980's had produced {approx}21 cc of gas per gram of a LANA30 material (LaNi4.7Al0.3), with approximately 67% of that being {sup 3}He and the rest being D{sub 2} (Fig.3). However, the material had to be heated in excess of 850 C to obtain that level. Heating to less produced approximately half that amount of gas. The data also showed that {sup 3}He was released at different temperatures …
Date: December 1, 2010
Creator: Shanahan, K.
System: The UNT Digital Library
Combination of Standard Model Higgs searches at CDF (open access)

Combination of Standard Model Higgs searches at CDF

We present the latest combination of searches for a standard model (SM) Higgs boson in p{bar p} collisions at {radical}s = 1.96 TeV recorded by the CDF II detector at the Fermilab Tevatron. Using data corresponding to 2.3-5.9 fb{sup -1} of integrated luminosity, we perform searches in a number of different production and decay modes and then combine them to improve sensitivity. No excess in data above that expected from backgrounds is observed; therefore, we set upper limits on the production cross section times branching fraction as a function of the SM Higgs boson mass (m{sub H}). The combined observed (expected) limit is 1.9 (1.8) times the SM prediction at m{sub H} =115 GeV/c{sup 2} and 1.0 (1.1) times the SM prediction at m{sub H} = 165 GeV/c{sup 2}.
Date: December 1, 2010
Creator: Potamianos, Karolos
System: The UNT Digital Library
The ecloud measurement setup in the Main Injector (open access)

The ecloud measurement setup in the Main Injector

Ecloud has been observed in many high intensity accelerators which can limit the amount of current that can be stored in them. In particular, for ProjectX, the amount of beam current that will be stored in the MI (Main Injector) will be {approx}160 x 10{sup 12} protons while the present maximum intensity is {approx}45 x 10{sup 12} protons which is about 3.5x less beam. Although ecloud has been observed in the MI, it has not caused instabilities at the present running conditions. However, there is no guarantee that instabilities caused by ecloud will not be a problem at ProjectX intensities. Therefore, a program has been started to study the ecloud effects with both computer simulations and experiments. In this paper, we will be focusing our attention on how coatings can affect the production of secondary electrons. We have installed an ecloud measurement setup in a straight section of MI which consists of one coated and one uncoated beam pipe with the same physical dimensions and at the same location, together with four retarding field analyzers (RFAs) and three sets of beam position monitors (BPMs) which can be used for the microwave measurements. An ecloud measurement setup was installed in a …
Date: December 1, 2010
Creator: Tan, C.Y.; Backfish, M.; Zwaska, R. & /Fermilab
System: The UNT Digital Library
A simple, high-yield, apparatus for NEG coating of vacuum beamline elements (open access)

A simple, high-yield, apparatus for NEG coating of vacuum beamline elements

Non-Evaporable Getter (NEG) materials are extremely useful in vacuum systems for achieving Ultra High Vacuum. Recently, these materials have been used to coat the inner surfaces of vacuum components, acting as an internal, passive, vacuum pump. We have constructed a low cost apparatus, which allows coating of very small diameter vacuum tubes, used as differential pumping stages. Despite the relative ease of construction, we are routinely able to achieve high coating yields. We further describe an improvement to our system, which is able to achieve the same yield, at an even lower complexity by using an easily manufactured permanent magnet arrangement. The designs described are extendible to virtually any combination of length and diameter of the components to be coated.
Date: December 1, 2010
Creator: Ron, Guy; Oort, Ron & Lee, Daniel
System: The UNT Digital Library
Challenges Surrounding the Injection and Arrival of Targets at LIFE Fusion Chamber Center (open access)

Challenges Surrounding the Injection and Arrival of Targets at LIFE Fusion Chamber Center

IFE target designers must consider several engineering requirements in addition to the physics requirements for successful target implosion. These considerations include low target cost, high manufacturing throughput, the ability of the target to survive the injection into the fusion chamber and arrive in a condition and physical position consistent with proper laser-target interaction and ease of post-implosion debris removal. This article briefly describes these considerations for the Laser Inertial Fusion-based Energy (LIFE) targets currently being designed.
Date: December 1, 2010
Creator: Miles, R.; Spaeth, M.; Manes, K.; Amendt, P.; Tabak, M.; Bond, T. et al.
System: The UNT Digital Library
Search for Randall-Sundrum Gravitons in the Diphoton Channel at CDF (open access)

Search for Randall-Sundrum Gravitons in the Diphoton Channel at CDF

We report on a search for new particles in the diphoton channel using a data sample of p{bar p} collisions at {radical}s = 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron, with an integrated luminosity of 5.4 fb{sup -1}. The diphoton invariant mass spectrum of the data agrees well with the standard model expectation. We set upper limits on the production cross section times branching ratio for the Randall-Sundrum graviton, as a function of diphoton mass. We subsequently derive lower limits on the graviton mass of 482 GeV/c{sup 2} and 975 GeV/c{sup 2}, at the 95% confidence level, for coupling parameters (k/{bar M}{sub Pl}) of 0.01 and 0.1 respectively.
Date: December 1, 2010
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of et al.
System: The UNT Digital Library
Development of Performance Acceptance Test Guidelines for Large Commercial Parabolic Trough Solar Fields: Preprint (open access)

Development of Performance Acceptance Test Guidelines for Large Commercial Parabolic Trough Solar Fields: Preprint

Prior to commercial operation, large solar systems in utility-size power plants need to pass a performance acceptance test conducted by the EPC contractor or owners. In lieu of the present absence of engineering code developed for this purpose, NREL has undertaken the development of interim guidelines to provide recommendations for test procedures that can yield results of a high level of accuracy consistent with good engineering knowledge and practice. The fundamental differences between acceptance of a solar power plant and a conventional fossil-fired plant are the transient nature of the energy source and the necessity to utilize an analytical performance model in the acceptance process. These factors bring into play the need to establish methods to measure steady state performance, potential impacts of transient processes, comparison to performance model results, and the possible requirement to test, or model, multi-day performance within the scope of the acceptance test procedure. The power block and BOP are not within the boundaries of this guideline. The current guideline is restricted to the solar thermal performance of parabolic trough systems and has been critiqued by a broad range of stakeholders in CSP development and technology.
Date: December 1, 2010
Creator: Kearney, D. & Mehos, M.
System: The UNT Digital Library
Search for leptoquarks and technicolor at the Tevatron (open access)

Search for leptoquarks and technicolor at the Tevatron

This note summarizes results on leptoquarks and technicolor searches at the Tevatron with a more particular focus on recent ones. Results on leptoquark pair production with leptoquark decays to q{nu}, qe, q{mu} and q{tau} are given for an analysed luminosity up to 5.2 fb{sup -1}. In most analyses, both leptoquarks decay identically leading to signatures of jets and missing transverse momentum or jets and charged leptons. Technicolor results are given with a particular emphasis on technirho decaying toWZ in a trilepton signature and on technirho decaying to aW and a technipion.
Date: December 1, 2010
Creator: Grenier, Gerald & /Lyon, IPN
System: The UNT Digital Library
Poroelastic response of orthotropic fractured porous media (open access)

Poroelastic response of orthotropic fractured porous media

An algorithm is presented for inverting either laboratory or field poroelastic data for all the drained constants of an anisotropic (specifically orthotropic) fractured poroelastic system. While fractures normally weaken the system by increasing the mechanical compliance, any liquids present in these fractures are expected to increase the stiffness somewhat, thus negating to some extent the mechanical weakening influence of the fractures themselves. The analysis presented quantifies these effects and shows that the key physical variable needed to account for the pore-fluid effects is a factor of (1 - B), where B is Skempton's second coe#14;fficient and satisfies 0 {<=} #20; B < 1. This scalar factor uniformly reduces the increase in compliance due to the presence of communicating fractures, thereby stiffening the fractured composite medium by a predictable amount. One further goal of the discussion is to determine how many of the poroelastic constants need to be known by other means in order to determine the rest from remote measurements, such as seismic wave propagation data in the field. Quantitative examples arising in the analysis show that, if the fracture aspect ratio a{sub f} ~ 0.1 and the pore fluid is liquid water, then for several cases considered Skempton's B …
Date: December 1, 2010
Creator: Berryman, J.G.
System: The UNT Digital Library
&quot;High Quantum Efficiency of Band-Edge Emission from ZnO Nanowires&quot; (open access)

&quot;High Quantum Efficiency of Band-Edge Emission from ZnO Nanowires&quot;

External quantum efficiency (EQE) of photoluminescence as high as 20 percent from isolated ZnO nanowires were measured at room temperature. The EQE was found to be highly dependent on photoexcitation density, which underscores the importance of uniform optical excitation during the EQE measurement. An integrating sphere coupled to a microscopic imaging system was used in this work, which enabled the EQE measurement on isolated ZnO nanowires. The EQE values obtained here are significantly higher than those reported for ZnO materials in forms of bulk, thin films or powders. Additional insight on the radiative extraction factor of one-dimensional nanostructures was gained by measuring the internal quantum efficiency of individual nanowires. Such quantitative EQE measurements provide a sensitive, noninvasive method to characterize the optical properties of low-dimensional nanostructures and allow tuning of synthesis parameters for optimization of nanoscale materials.
Date: December 1, 2010
Creator: Gargas, Daniel; Gao, Hanwei; Wang, Hungta & Peidong, Yang
System: The UNT Digital Library
Electrospun a-Si using Liquid Silane/Polymer Inks (open access)

Electrospun a-Si using Liquid Silane/Polymer Inks

Amorphous silicon nanowires (a-SiNWs) were prepared by electrospinning cyclohexasilane (Si{sub 6}H{sub 12}) admixed with polymethylmethacrylate (PMMA) in toluene. Raman spectroscopy characterization of these wires (d {approx} 50-2000 nm) shows 350 C treatment yields a-SiNWs. Porous a-SiNWs are obtained using a volatile polymer.
Date: December 1, 2010
Creator: Schulz, D.L.; Hoey, J.M.; Smith, J.; Lovaasen, J.; Braun, C.; Dai, X. et al.
System: The UNT Digital Library
IDR muon capture front end and variations (open access)

IDR muon capture front end and variations

The (International Design Report) IDR neutrino factory scenario for capture, bunching, phase-energy rotation and initial cooling of {mu}'s produced from a proton source target is explored. It requires a drift section from the target, a bunching section and a {phi}-{delta}E rotation section leading into the cooling channel. The rf frequency changes along the bunching and rotation transport in order to form the {mu}'s into a train of equal-energy bunches suitable for cooling and acceleration. Optimization and variations are discussed. An important concern is rf limitations within the focusing magnetic fields; mitigation procedures are described. The method can be extended to provide muons for a {mu}{sup +}-{mu}{sup -} Collider; variations toward optimizing that extension are discussed.
Date: December 1, 2010
Creator: Neuffer, David; Prior, Gersende; Rogers, Christopher; Snopok, Pavel & Yoshikawa, Cary
System: The UNT Digital Library
Visualization at Supercomputing Centers: The Tale of Little Big Iron and the Three Skinny Guys (open access)

Visualization at Supercomputing Centers: The Tale of Little Big Iron and the Three Skinny Guys

Supercomputing Centers (SC's) are unique resources that aim to enable scientific knowledge discovery through the use of large computational resources, the Big Iron. Design, acquisition, installation, and management of the Big Iron are activities that are carefully planned and monitored. Since these Big Iron systems produce a tsunami of data, it is natural to co-locate visualization and analysis infrastructure as part of the same facility. This infrastructure consists of hardware (Little Iron) and staff (Skinny Guys). Our collective experience suggests that design, acquisition, installation, and management of the Little Iron and Skinny Guys does not receive the same level of treatment as that of the Big Iron. The main focus of this article is to explore different aspects of planning, designing, fielding, and maintaining the visualization and analysis infrastructure at supercomputing centers. Some of the questions we explore in this article include:&quot;How should the Little Iron be sized to adequately support visualization and analysis of data coming off the Big Iron?&quot; What sort of capabilities does it need to have?&quot; Related questions concern the size of visualization support staff:&quot;How big should a visualization program be (number of persons) and what should the staff do?&quot; and&quot;How much of the visualization should …
Date: December 1, 2010
Creator: Bethel, E. Wes; van Rosendale, John; Southard, Dale; Gaither, Kelly; Childs, Hank; Brugger, Eric et al.
System: The UNT Digital Library
Macro-System Model: A Federated Object Model for Cross-Cutting Analysis of Hydrogen Production, Delivery, Consumption and Associated Emissions; Preprint (open access)

Macro-System Model: A Federated Object Model for Cross-Cutting Analysis of Hydrogen Production, Delivery, Consumption and Associated Emissions; Preprint

It is commonly accepted that the introduction of hydrogen as an energy carrier for light-duty vehicles involves concomitant technological development of infrastructure elements, such as production, delivery, and consumption, all associated with certain emission levels. To analyze these at a system level, the suite of corresponding models developed by the United States Department of Energy and involving several national laboratories is combined in one macro-system model (MSM). The macro-system model is being developed as a cross-cutting analysis tool that combines a set of hydrogen technology analysis models. Within the MSM, a federated simulation framework is used for consistent data transfer between the component models. The framework is built to suit cross-model as well as cross-platform data exchange and involves features of 'over-the-net' computation.
Date: December 1, 2010
Creator: Ruth, M.; Diakov, V.; Goldsby, M. E. & Sa, T. J.
System: The UNT Digital Library
PhyloChip microarray analysis reveals altered gastrointestinal microbial communities in a rat model of colonic hypersensitivity (open access)

PhyloChip microarray analysis reveals altered gastrointestinal microbial communities in a rat model of colonic hypersensitivity

Irritable bowel syndrome (IBS) is a chronic, episodic gastrointestinal disorder that is prevalent in a significant fraction of western human populations; and changes in the microbiota of the large bowel have been implicated in the pathology of the disease. Using a novel comprehensive, high-density DNA microarray (PhyloChip) we performed a phylogenetic analysis of the microbial community of the large bowel in a rat model in which intracolonic acetic acid in neonates was used to induce long lasting colonic hypersensitivity and decreased stool water content and frequency, representing the equivalent of human constipation-predominant IBS. Our results revealed a significantly increased compositional difference in the microbial communities in rats with neonatal irritation as compared with controls. Even more striking was the dramatic change in the ratio of Firmicutes relative to Bacteroidetes, where neonatally irritated rats were enriched more with Bacteroidetes and also contained a different composition of species within this phylum. Our study also revealed differences at the level of bacterial families and species. The PhyloChip is a useful and convenient method to study enteric microflora. Further, this rat model system may be a useful experimental platform to study the causes and consequences of changes in microbial community composition associated with IBS.
Date: December 1, 2010
Creator: Nelson, T. A.; Holmes, S.; Alekseyenko, A. V.; Shenoy, M.; DeSantis, T.; Wu, C. H. et al.
System: The UNT Digital Library
Theoretical and Experimental Thermal Performance Analysis of Complex Thermal Storage Membrane Containing Bio-Based Phase Change Material (PCM) (open access)

Theoretical and Experimental Thermal Performance Analysis of Complex Thermal Storage Membrane Containing Bio-Based Phase Change Material (PCM)

Since 2000, an ORNL research team has been testing different configurations of PCM-enhanced building envelop components to be used in residential and commercial buildings. During 2009, a novel type of thermal storage membrane was evaluated for building envelope applications. Bio-based PCM was encapsulated between two layers of heavy-duty plastic film forming a complex array of small PCM cells. Today, a large group of PCM products are packaged in such complex PCM containers or foils containing arrays of PCM pouches of different shapes and sizes. The transient characteristics of PCM-enhanced building envelope materials depend on the quality and amount of PCM, which is very often difficult to estimate because of the complex geometry of many PCM heat sinks. The only widely used small-scale analysis method used to evaluate the dynamic characteristics of PCM-enhanced building products is the differential scanning calorimeter (DSC). Unfortunately, this method requires relatively uniform, and very small, specimens of the material. However, in numerous building thermal storage applications, PCM products are not uniformly distributed across the surface area, making the results of traditional DSC measurements unrealistic for these products. In addition, most of the PCM-enhanced building products contain blends of PCM with fire retardants and chemical stabilizers. This …
Date: December 1, 2010
Creator: Kosny, Jan; Stovall, Therese K; Shrestha, Som S & Yarbrough, David W
System: The UNT Digital Library