WorldWideScience

Sample records for plan foam delivery

  1. Research Plan: Foam Delivery of Remedial Amendments to Deep Vadose Zone for Metals and Radionuclides Remediation

    International Nuclear Information System (INIS)

    Zhong, Lirong; Hart, Andrea T.; Szecsody, James E.; Zhang, Z.F.; Freedman, Vicky L.; Ankeny, Mark; Hull, Laurence; Oostrom, Martinus; Freshley, Mark D.; Wellman, Dawn M.

    2009-01-01

    Research proposals were submitted to the Scientific and Technical Basis for In Situ Treatment of Metals and Radionuclides Technical Working Group under the US Department of Energy (DOE) Environmental Management Office (specifically, EM-22). After a peer review and selection process, the proposal, 'Foam Delivery of Remedial Amendments to Deep Vadose Zone for Metals and Radionuclides Remediation,' submitted by Pacific Northwest National Laboratory (PNNL) was selected for support by the program. A research plan was requested for this EM funded project. The overall objective of this project is to develop foam delivery technology for the distribution of remedial amendments to deep vadose zone sediments for in situ immobilization of metal and radionuclide contaminants. The focus of this research in FY 2009 is on the physical aspects of the foam delivery approach. Specific objectives are to (1) study the foam quality (i.e. the gas volume fraction in foam) influence on injection pressure, (2) study the sediment air permeability influence on injection pressure, (3) investigate liquid uptake in sediment and determine whether a water front will be formed during foam delivery, (4) test amendment distance (and mass) delivery by foam from the injection point, (5) study the enhanced sweeping over heterogeneous systems (i.e., low K zones) by foam delivery relative to water-based delivery under vadose zone conditions, and (6) numerically simulate foam delivery processes in the vadose zone. Laboratory scale experiments will be conducted at PNNL to study a range of basic physical aspects of the foam propagation in sediments, including foam quality and sediment permeability influence on injection pressure, liquid uptake, and foam sweeping across heterogeneous systems. This study will be augmented with separate studies to be conducted at MSE Technology Applications, Inc. (MSE) to evaluate foam transport and amendment delivery at the intermediate-scale. The results of intermediate

  2. Drug delivery properties of macroporous polystyrene solid foams.

    Science.gov (United States)

    Canal, Cristina; Aparicio, Rosa Maria; Vilchez, Alejandro; Esquena, Jordi; García-Celma, Maria José

    2012-01-01

    Polymeric porous foams have been evaluated as possible new pharmaceutical dosage forms. These materials were obtained by polymerization in the continuous phase of highly concentrated emulsions prepared by the phase inversion temperature method. Their porosity, specific surface and surface topography were characterized, and the incorporation and release of active principles was studied using ketoprofen as model lipophilic molecule. Solid foams with very high pore volume, mainly inside macropores, were obtained by this method. The pore morphology of the materials was characterized, and very rough topography was observed, which contributed to their nearly superhydrophobic properties. These solid foams could be used as delivery systems for active principles with pharmaceutical interest, and in the present work ketoprofen was used as a model lipophilic molecule. Drug incorporation and release was studied from solid foam disks, using different concentrations of the loading solutions, achieving a delayed release with short lag-time.

  3. System Description for the K-25/K-27 D and D Project Polyurethane Foam Delivery System, East Tennessee Technology Park, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Boris, G.

    2008-01-01

    The Foam Delivery System used in the decontamination and decommissioning (D and D) project for the K-25/K-27 Buildings at the East Tennessee Technology Park (ETTP) is comprised of a trailer-mounted Gusmer(reg s ign) H20/35 Pro-TEC Proportioning Unit and the associated equipment to convey electrical power, air, and foam component material to the unit. This high-pressure, plural-component polyurethane foam pouring system will be used to fill process gas and non-process equipment/piping (PGE/P) within the K-25/K-27 Buildings with polyurethane foam to immobilize contaminants prior to removal. The system creates foam by mixing isocyanate and polyol resin (Resin) component materials. Currently, the project plans to utilize up to six foaming units simultaneously during peak foaming activities. Also included in this system description are the foam component material storage containers that will be used for storage of the component material drums in a staging area outside of the K-25/K-27 Buildings. The Foam Delivery System and foam component material storage enclosures (i.e., Foaming Component Protective Enclosures) used to store polymeric methylene diphenyl diisocyanate (PMDI) component material are identified as Safety Significant (SS) Structures, Systems and Components (SSC) in the Documented Safety Analysis (DSA) for the project, Documented Safety Analysis for the K-25 and K-27 Facilities at the East Tennessee Technology Park, Oak Ridge, Tennessee, DSA-ET-K-25/K-27-0001

  4. Foam-Delivery of Remedial Amendments for Enhanced Vadose Zone Metals and Radionuclides Remediation

    International Nuclear Information System (INIS)

    Zhong, L.; Szecsody, J.E.; Dresel, P.E.; Zhang, Z.F.; Qafoku, N.P.

    2009-01-01

    The remediation of metals and radionuclides contamination, such as Cr(VI), Tc-99, and Sr-90 in the U.S. DOE Hanford Site vadose zone is a critical need. Water-based remedial amendments delivery to the deep vadose zone is facing significant technical challenges. Water-based delivery will easily leach out the highly mobile pollutants therefore contaminate the underlying aquifer. Preferential flow of the amendment-laden solution in the vadose zone due to the formation heterogeneity is difficult to overcome, resulting in bypassing of the less permeable zones. Foam has unique transport properties in the vadose zone that enable mitigation on the mobilization of mobile contaminants and enhance the sweeping over heterogeneous systems. Calcium polysulfide (CPS) is a remedial amendment that can be used to reduce and immobilize hexavalent chromium [Cr(VI)] and other redox-sensitive radionuclides/metals in the vadose zone. The delivery of CPS to the vadose zone using foam and the immobilization of Cr(VI) via reduction by the foam-delivered CPS was investigated in this study. Batch tests were conducted to select the foam-generating CPS-surfactant solutions, to determine the solution foamability and the reducing potential of CPS-containing foams, and to study the influence of foam quality, surfactant concentration, and CPS concentration on foam stability. Column experiments were performed to test the foam delivery of CPS to sediments under conditions similar to field vadose zone, to study the foam transport and interaction with sediments, and to determine the extent of Cr(VI) immobilization using this novel delivery approach. CPS-containing foams with high reducing potential were prepared based on the batch tests. Sediment reduction by foam-delivered CPS was observed in the column studies. Significant mobilization of Cr(VI) from sediments occurred when CPS was delivered in aqueous solution. The Cr(VI) mobilization was minimized when CPS was delivered by foams, resulting in

  5. Waste feed delivery test and evaluation plan

    Energy Technology Data Exchange (ETDEWEB)

    O' TOOLE, S.M.

    1999-09-30

    This plan documents the Waste Feed Delivery Program test and evaluation planning and implementation approach. The purpose of this document is to define and communicate the Waste Feed Delivery Program Test and Evaluation scope, objectives, planning and implementation approach.

  6. Waste feed delivery test and evaluation plan

    International Nuclear Information System (INIS)

    O'TOOLE, S.M.

    1999-01-01

    This plan documents the Waste Feed Delivery Program test and evaluation planning and implementation approach. The purpose of this document is to define and communicate the Waste Feed Delivery Program Test and Evaluation scope, objectives, planning and implementation approach

  7. Drug delivery properties of macroporous polystyrene solid foams

    OpenAIRE

    Canal Barnils, Cristina; Aparicio, Rosa María; Vílchez, Alejandro; Esquena, Jordi; García-Celma, María José

    2012-01-01

    Purpose. Polymeric porous foams have been evaluated as possible new pharmaceutical dosage forms. Methods. These materials were obtained by polymerization in the continuous phase of highly concentrated emulsions prepared by the phase inversion temperature method. Their porosity, specific surface and surface topography were characterized, and the incorporation and release of active principles was studied using ketoprofen as model lipophilic molecule. Results. Solid foams with very h...

  8. Modeling foam delivery mechanisms in deep vadose-zone remediation using method of characteristics

    International Nuclear Information System (INIS)

    Roostapour, A.; Kam, S.I.

    2012-01-01

    Highlights: ► A new mathematical framework established for vadose-zone foam remediation. ► Graphical solutions presented by Method of Characteristics quantitatively. ► Effects of design parameters in the field applications thoroughly investigated. ► Implication of modeling study for successful field treatment discussed. - Abstract: This study investigates foam delivery mechanisms in vadose-zone remediation by using Method of Characteristics (MoC), a mathematical tool long been used for the analysis of miscible and immiscible flooding in porous media in petroleum industry. MoC converts the governing material-balance partial differential equations into a series of ordinary differential equations, and the resulting solutions are in a form of wave propagation (more specifically, for chemical species and phase saturations) through the system as a function of time and space. Deep vadose-zone remediation has special features compared to other conventional remediation applications. They include, not limited to, a high level of heterogeneity, a very dry initial condition with low water saturation (S w ), pollutants such as metals and radionuclides fully dissolved in groundwater, and a serious concern about downward migration during the remediation treatments. For the vadose-zone remediation processes to be successful, the injected aqueous phase should carry chemicals to react with pollutants and precipitate them for immobilization and stabilization purposes. As a result, foams are believed to be an effective means, and understanding foam flow mechanism in situ is a key to the optimal design of field applications. Results show that foam delivery mechanism is indeed very complicated, making the optimum injection condition field-specific. The five major parameters selected (i.e., initial saturation of the medium, injection foam quality, surfactant adsorption, foam strength, and foam stability) are shown to be all important, interacting with each other. Results also

  9. 77 FR 44306 - Service Delivery Plan

    Science.gov (United States)

    2012-07-27

    ... SOCIAL SECURITY ADMINISTRATION [Docket No. SSA-2012-0048] Service Delivery Plan AGENCY: Social... input as we develop our Service Delivery Plan (SDP). We recently completed our Agency Strategic Plan... how we plan to provide our services over the next four years and beyond. DATES: To ensure that we...

  10. Modeling foam delivery mechanisms in deep vadose-zone remediation using method of characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Roostapour, A. [Craft and Hawkins Department of Petroleum Engineering, Louisiana State University, Baton Rouge, LA 70803 (United States); Kam, S.I., E-mail: kam@lsu.edu [Craft and Hawkins Department of Petroleum Engineering, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer A new mathematical framework established for vadose-zone foam remediation. Black-Right-Pointing-Pointer Graphical solutions presented by Method of Characteristics quantitatively. Black-Right-Pointing-Pointer Effects of design parameters in the field applications thoroughly investigated. Black-Right-Pointing-Pointer Implication of modeling study for successful field treatment discussed. - Abstract: This study investigates foam delivery mechanisms in vadose-zone remediation by using Method of Characteristics (MoC), a mathematical tool long been used for the analysis of miscible and immiscible flooding in porous media in petroleum industry. MoC converts the governing material-balance partial differential equations into a series of ordinary differential equations, and the resulting solutions are in a form of wave propagation (more specifically, for chemical species and phase saturations) through the system as a function of time and space. Deep vadose-zone remediation has special features compared to other conventional remediation applications. They include, not limited to, a high level of heterogeneity, a very dry initial condition with low water saturation (S{sub w}), pollutants such as metals and radionuclides fully dissolved in groundwater, and a serious concern about downward migration during the remediation treatments. For the vadose-zone remediation processes to be successful, the injected aqueous phase should carry chemicals to react with pollutants and precipitate them for immobilization and stabilization purposes. As a result, foams are believed to be an effective means, and understanding foam flow mechanism in situ is a key to the optimal design of field applications. Results show that foam delivery mechanism is indeed very complicated, making the optimum injection condition field-specific. The five major parameters selected (i.e., initial saturation of the medium, injection foam quality, surfactant adsorption, foam

  11. 78 FR 15797 - Service Delivery Plan

    Science.gov (United States)

    2013-03-12

    ... SOCIAL SECURITY ADMINISTRATION [Docket No. SSA-2012-0048] Service Delivery Plan AGENCY: Social... input as we finalize our Service Delivery Plan (SDP). We designed our SDP as a roadmap for how we will... Plan. DATES: To ensure that we consider your comments, we must receive them no later than April 11...

  12. Foam - novel delivery technology for remediation of vadose zone environments - 59019

    International Nuclear Information System (INIS)

    Jansik, Danielle; Wellman, Dawn M.; Mattigod, Shas V.; Zhong, Lirong; Zhang, Fred; Foote, Martin; Wu, Yuxin; Hubbard, Susan

    2012-01-01

    Deep vadose zone environments can be a primary source and pathway for contaminant migration to groundwater. These environments present unique characterization and remediation challenges that necessitate scrutiny and research. The thickness, depth, and intricacies of the deep vadose zone, combined with a lack of understanding of the key subsurface processes (e.g., biogeochemical and hydrologic) affecting contaminant migration, make it difficult to create validated conceptual and predictive models of subsurface flow dynamics and contaminant behavior across multiple scales. These factors also make it difficult to design and deploy sustainable remedial approaches and monitor long-term contaminant behavior after remedial actions. Functionally, methods for addressing contamination must remove and/or reduce transport of contaminants. This problem is particularly challenging in the arid western United States where the vadose zone is hundreds of feet thick, rendering transitional excavation methods exceedingly costly and ineffective. Delivery of remedial amendments is one of the most challenging and critical aspects for all remedy-based approaches. The conventional approach for delivery is through injection of aqueous remedial solutions. However, heterogeneous deep vadose zone environments present hydrologic and geochemical challenges that limit the effectiveness. Because the flow of solution infiltration is dominantly controlled by gravity and suction, injected liquid preferentially percolates through highly permeable pathways, by-passing low-permeability zones that frequently contain the majority of contamination. Moreover, the wetting front can readily mobilize and enhance contaminant transport to the underlying aquifer prior to stabilization. Development of innovative in-situ technologies may be the only means to meet remedial action objectives and long-term stewardship goals. Surfactants can be used to lower the liquid surface tension and create stabile foams, which

  13. 78 FR 16753 - Service Delivery Plan; Correction

    Science.gov (United States)

    2013-03-18

    ... the first sentence after the words, ``Service Delivery Plan (SDP) insert http://www.ssa.gov/open/SDP... http://ssa.gov/asp/plan-2013-2016.pdf . Paul Kryglik, Director, Office of Regulations, Social Security...

  14. Waste feed delivery planning at Hanford-13232

    International Nuclear Information System (INIS)

    Certa, Paul J.; West, Elizha B.; Rodriguez, Juissepp S.; Hohl, Ted M.; Larsen, Douglas C.; Ritari, Jaakob S.; Kelly, James W.

    2013-01-01

    The Integrated Waste Feed Delivery Plan (IWFDP) describes how waste feed will be delivered to the Waste Treatment and Immobilization Plant (WTP) to safely and efficiently accomplish the River Protection Project (RPP) mission. The IWFDP, which is integrated with the Baseline Case operating scenario, is comprised of three volumes. Volume 1 - Process Strategy provides an overview of waste feed delivery (WFD) and describes how the WFD system will be used to prepare and deliver feed to the WTP based on the equipment configuration and functional capabilities of the WFD system. Volume 2 - Campaign Plan describes the plans for the first eight campaigns for delivery to the WTP, evaluates projected feed for systematic issues, projects 242-A Evaporator campaigns, and evaluates double-shell tank (DST) space and availability of contingency feed. Volume 3 - Project Plan identifies the scope and timing of the DST and infrastructure upgrade projects necessary to feed the WTP, and coordinates over 30 projectized projects and operational activities that comprise the needed WFD upgrades

  15. Waste Feed Delivery Planning at Hanford - 13232

    International Nuclear Information System (INIS)

    Certa, Paul J.; Hohl, Ted M.; Kelly, James W.; Larsen, Douglas C.; West, Elizha B.; Ritari, Jaakob S.; Rodriguez, Juissepp S.

    2013-01-01

    The Integrated Waste Feed Delivery Plan (IWFDP) describes how waste feed will be delivered to the Waste Treatment and Immobilization Plant (WTP) to safely and efficiently accomplish the River Protection Project (RPP) mission. The IWFDP, which is integrated with the Baseline Case operating scenario, is comprised of three volumes. Volume 1 - Process Strategy provides an overview of waste feed delivery (WFD) and describes how the WFD system will be used to prepare and deliver feed to the WTP based on the equipment configuration and functional capabilities of the WFD system. Volume 2 - Campaign Plan describes the plans for the first eight campaigns for delivery to the WTP, evaluates projected feed for systematic issues, projects 242-A Evaporator campaigns, and evaluates double-shell tank (DST) space and availability of contingency feed. Volume 3 - Project Plan identifies the scope and timing of the DST and infrastructure upgrade projects necessary to feed the WTP, and coordinates over 30 projectized projects and operational activities that comprise the needed WFD upgrades. (authors)

  16. Waste Feed Delivery Planning at Hanford - 13232

    Energy Technology Data Exchange (ETDEWEB)

    Certa, Paul J.; Hohl, Ted M.; Kelly, James W.; Larsen, Douglas C.; West, Elizha B.; Ritari, Jaakob S.; Rodriguez, Juissepp S. [Washington River Protection Solutions, LLC, P.O. 850, Richland, WA 99352 (United States)

    2013-07-01

    The Integrated Waste Feed Delivery Plan (IWFDP) describes how waste feed will be delivered to the Waste Treatment and Immobilization Plant (WTP) to safely and efficiently accomplish the River Protection Project (RPP) mission. The IWFDP, which is integrated with the Baseline Case operating scenario, is comprised of three volumes. Volume 1 - Process Strategy provides an overview of waste feed delivery (WFD) and describes how the WFD system will be used to prepare and deliver feed to the WTP based on the equipment configuration and functional capabilities of the WFD system. Volume 2 - Campaign Plan describes the plans for the first eight campaigns for delivery to the WTP, evaluates projected feed for systematic issues, projects 242-A Evaporator campaigns, and evaluates double-shell tank (DST) space and availability of contingency feed. Volume 3 - Project Plan identifies the scope and timing of the DST and infrastructure upgrade projects necessary to feed the WTP, and coordinates over 30 projectized projects and operational activities that comprise the needed WFD upgrades. (authors)

  17. Thiolated Chitosan Masked Polymeric Microspheres with Incorporated Mesocellular Silica Foam (MCF for Intranasal Delivery of Paliperidone

    Directory of Open Access Journals (Sweden)

    Stavroula Nanaki

    2017-11-01

    Full Text Available In this study, mesocellular silica foam (MCF was used to encapsulate paliperidone, an antipsychotic drug used in patients suffering from bipolar disorder. MCF with the drug adsorbed was further encapsulated into poly(lactic acid (PLA and poly(lactide-co-glycolide (PLGA 75/25 w/w microspheres and these have been coated with thiolated chitosan. As found by TEM analysis, thiolated chitosan formed a thin layer on the polymeric microspheres’ surface and was used in order to enhance their mucoadhesiveness. These microspheres aimed at the intranasal delivery of paliperidone. The DSC and XRD studies showed that paliperidone was encapsulated in amorphous form inside the MCF silica and for this reason its dissolution profile was enhanced compared to the neat drug. In coated microspheres, thiolated chitosan reduced the initial burst effect of the paliperidone dissolution profile and in all cases sustained release formulations have been prepared. The release mechanism was also theoretically studied and three kinetic models were proposed and successfully fitted for a dissolution profile of prepared formulations to be found.

  18. Solid cellulose nanofiber based foams - Towards facile design of sustained drug delivery systems

    DEFF Research Database (Denmark)

    Svagan, Anna J; Benjamins, Jan-Willem; Al-Ansari, Zeinab

    2016-01-01

    acceptable surfactant (lauric acid sodium salt). The drug was suspended in the wet-stable foams followed by a drying step to obtain dry foams. Flexible cellular solid materials of different thicknesses, shapes and drug loadings (up to 50wt%) could successfully be prepared. The drug was released from...... the solid foams in a diffusion-controlled, sustained manner due to the presence of intact air bubbles which imparted a tortuous diffusion path. The diffusion coefficient was assessed using Franz cells and shown to be more than one order of magnitude lower for the cellular solids compared to the bubble...

  19. planning for gender equitable services delivery in a decentralised ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Sarah Ssali

    Services Delivery in Uganda. – Services offered. – Participation. – Decision making process. – Actors. – Issues. • Post-Conflict Situations in Uganda. – Challenges from Conflict. – Decentralisation in Post conflict settings. – Planning for gender equitable services delivery. • Recommendations (Policy). • Research Gaps ...

  20. Waste Feed Delivery Environmental Permits and Approvals Plan

    Energy Technology Data Exchange (ETDEWEB)

    TOLLEFSON, K.S.

    2000-01-18

    This plan describes the environmental permits approvals, and other requirements that may affect establishment of a waste feed delivery system for the Hanford Site's River Protection Project. This plan identifies and screens environmental standards for potential applicability, outlines alternatives for satisfying applicable standards, and describes preferred permitting and approval approaches.

  1. Waste Feed Delivery Environmental Permits and Approvals Plan

    International Nuclear Information System (INIS)

    TOLLEFSON, K.S.

    2000-01-01

    This plan describes the environmental permits approvals, and other requirements that may affect establishment of a waste feed delivery system for the Hanford Site's River Protection Project. This plan identifies and screens environmental standards for potential applicability, outlines alternatives for satisfying applicable standards, and describes preferred permitting and approval approaches

  2. Prostate HDR brachytherapy catheter displacement between planning and treatment delivery

    International Nuclear Information System (INIS)

    Whitaker, May; Hruby, George; Lovett, Aimee; Patanjali, Nitya

    2011-01-01

    Background and purpose: HDR brachytherapy is used as a conformal boost for treating prostate cancer. Given the large doses delivered, it is critical that the volume treated matches that planned. Our outpatient protocol comprises two 9 Gy fractions, two weeks apart. We prospectively assessed catheter displacement between CT planning and treatment delivery. Materials and methods: Three fiducial markers and the catheters were implanted under transrectal ultrasound guidance. Metal marker wires were inserted into 4 reference catheters before CT; marker positions relative to each other and to the marker wires were measured from the CT scout. Measurements were repeated immediately prior to treatment delivery using pelvic X-ray with marker wires in the same reference catheters. Measurements from CT scout and film were compared. For displacements of 5 mm or more, indexer positions were adjusted prior to treatment delivery. Results: Results are based on 48 implants, in 25 patients. Median time from planning CT to treatment delivery was 254 min (range 81–367 min). Median catheter displacement was 7.5 mm (range −2.9–23.9 mm), 67% of implants had displacement of 5 mm or greater. Displacements were predominantly caudal. Conclusions: Catheter displacement can occur in the 1–3 h between the planning CT scan and treatment. It is recommended that departments performing HDR prostate brachytherapy verify catheter positions immediately prior to treatment delivery.

  3. Process development work plan for waste feed delivery system

    International Nuclear Information System (INIS)

    Papp, I.G.

    1998-01-01

    This work plan defines the process used to develop project definition for Waste Feed Delivery (WFD). Project definition provides the direction for development of definitive design media required for the ultimate implementation of operational processing hardware and software. Outlines for the major deliverables are attached as appendices. The implementation of hardware and software will accommodate requirements for safe retrieval and delivery of waste currently stored in Hanford's underground storage tanks. Operations and maintenance ensure the availability of systems, structures, and components for current and future planned operations within the boundary of the Tank Waste Remediation System (TWRS) authorization basis

  4. A planning and delivery study of a rotational IMRT technique with burst delivery

    International Nuclear Information System (INIS)

    Kainz, Kristofer; Chen, Guang-Pei; Chang, Yu-Wen; Prah, Douglas; Sharon Qi, X.; Shukla, Himanshu P.; Stahl, Johannes; Allen Li, X.

    2011-01-01

    Purpose: A novel rotational IMRT (rIMRT) technique using burst delivery (continuous gantry rotation with beam off during MLC repositioning) is investigated. The authors evaluate the plan quality and delivery efficiency and accuracy of this dynamic technique with a conventional flat 6 MV photon beam. Methods: Burst-delivery rIMRT was implemented in a planning system and delivered with a 160-MLC linac. Ten rIMRT plans were generated for five anonymized patient cases encompassing head and neck, brain, prostate, and prone breast. All plans were analyzed retrospectively and not used for treatment. Among the varied plan parameters were the number of optimization points, number of arcs, gantry speed, and gantry angle range (alpha) over which the beam is turned on at each optimization point. Combined rotational/step-and-shoot rIMRT plans were also created by superimposing multiple-segment static fields at several optimization points. The rIMRT trial plans were compared with each other and with plans generated using helical tomotherapy and VMAT. Burst-mode rotational IMRT plans were delivered and verified using a diode array, ionization chambers, thermoluminescent dosimeters, and film. Results: Burst-mode rIMRT can achieve plan quality comparable to helical tomotherapy, while the former may lead to slightly better OAR sparing for certain cases and the latter generally achieves slightly lower hot spots. Few instances were found in which increasing the number of optimization points above 36, or superimposing step-and-shoot IMRT segments, led to statistically significant improvements in OAR sparing. Using an additional rIMRT partial arc yielded substantial OAR dose improvements for the brain case. Measured doses from the rIMRT plan delivery were within 4% of the plan calculation in low dose gradient regions. Delivery time range was 228-375 s for single-arc rIMRT 200-cGy prescription with a 300 MU/min dose rate, comparable to tomotherapy and VMAT. Conclusions: Rotational IMRT

  5. Waste feed delivery program systems engineering implementation plan

    International Nuclear Information System (INIS)

    O'Toole, S.M.; Hendel, B.J.

    1998-01-01

    This document defines the systems engineering processes and products planned by the Waste Feed Delivery Program to develop the necessary and sufficient systems to provide waste feed to the Privatization Contractor for Phase 1. It defines roles and responsibilities for the performance of the systems engineering processes and generation of products

  6. MDOT implementation plan for GPS technology in planning, design, and construction delivery

    Science.gov (United States)

    2010-09-13

    Global Positioning System (GPS) technology offers advantages to transportation agencies in the planning, design and construction stages of project delivery. This research study will develop a guide for Mississippi Department of Transportation (MDOT) ...

  7. MDOT implementation plan for global positioning systems (GPS) technology in planning, design, and construction delivery.

    Science.gov (United States)

    2010-09-13

    Global Positioning System (GPS) technology offers advantages to transportation agencies in the planning, design and construction stages of project delivery. This research study will develop a guide for Mississippi Department of Transportation (MDOT) ...

  8. Waste feed delivery environmental permits and approvals plan

    International Nuclear Information System (INIS)

    Papp, I.G.

    1998-01-01

    This document describes the range of environmental actions, including required permits and other agency approvals, that may affect waste feed delivery (WFD) activities in the Hanford Site's Tank Waste Remediation System (TWRS). This plan expands on the summary level information in the Tank Waste Remediation System Environmental Program Plan (HNF 1773) to address requirements that are most pertinent to WFD. This plan outlines alternative approaches to satisfying applicable environmental standards, and describes selected strategies for acquiring permits and other approvals needed for WFD to proceed. Appendices at the end of this plan provide preliminary cost and schedule estimates for implementing the selected strategies. The rest of this section summarizes the scope of WFD activities, including important TWRS operating information, and describes in more detail the objectives, structure, and content of this plan

  9. Quantitative dosimetric verification of an IMRT planning and delivery system

    International Nuclear Information System (INIS)

    Low, D.A.; Mutic, S.; Dempsey, J.F.; Gerber, R.L.; Bosch, W.R.; Perez, C.A.; Purdy, J.A.

    1998-01-01

    Background and purpose: The accuracy of dose calculation and delivery of a commercial serial tomotherapy treatment planning and delivery system (Peacock, NOMOS Corporation) was experimentally determined. Materials and methods: External beam fluence distributions were optimized and delivered to test treatment plan target volumes, including three with cylindrical targets with diameters ranging from 2.0 to 6.2 cm and lengths of 0.9 through 4.8 cm, one using three cylindrical targets and two using C-shaped targets surrounding a critical structure, each with different dose distribution optimization criteria. Computer overlays of film-measured and calculated planar dose distributions were used to assess the dose calculation and delivery spatial accuracy. A 0.125 cm 3 ionization chamber was used to conduct absolute point dosimetry verification. Thermoluminescent dosimetry chips, a small-volume ionization chamber and radiochromic film were used as independent checks of the ion chamber measurements. Results: Spatial localization accuracy was found to be better than ±2.0 mm in the transverse axes (with one exception of 3.0 mm) and ±1.5 mm in the longitudinal axis. Dosimetric verification using single slice delivery versions of the plans showed that the relative dose distribution was accurate to ±2% within and outside the target volumes (in high dose and low dose gradient regions) with a mean and standard deviation for all points of -0.05% and 1.1%, respectively. The absolute dose per monitor unit was found to vary by ±3.5% of the mean value due to the lack of consideration for leakage radiation and the limited scattered radiation integration in the dose calculation algorithm. To deliver the prescribed dose, adjustment of the monitor units by the measured ratio would be required. Conclusions: The treatment planning and delivery system offered suitably accurate spatial registration and dose delivery of serial tomotherapy generated dose distributions. The quantitative dose

  10. Strategic workforce planning for a multihospital, integrated delivery system.

    Science.gov (United States)

    Datz, David; Hallberg, Colleen; Harris, Kathy; Harrison, Lisa; Samples, Patience

    2012-01-01

    Banner Health has long recognized the need to anticipate, beyond the immediate operational realities or even the annual budgeting projection exercises, the necessary workforce needs of the future. Thus, in 2011, Banner implemented a workforce planning model that included structures, processes, and tools for predicting workforce needs, with particular focus on identified critical systemwide practice areas. The model represents the incorporation of labor management tools and processes with more strategic, broad-view, long-term assessment and planning mechanisms. The sequential tying of the workforce planning lifecycle with the organization's strategy and financial planning process supports alignment of goals, objectives, and resource allocation. Collaboration among strategy, finance, human resources, and operations has provided us with the ability to identify critical position groups based on 3-year strategic priorities. By engaging leaders from across the organization, focusing on activities at facility, regional, and system levels, and building in mechanisms for accountability, we are now engaged in continuous evaluations of our delivery models, the competencies and preparations necessary for the staff to effectively function within those delivery models, and developing and implementing action plans designed to ensure adequate numbers of the staff whose competencies will be suited to the work expected of them.

  11. Analysis of alcohol-based hand sanitizer delivery systems: efficacy of foam, gel, and wipes against influenza A (H1N1) virus on hands.

    Science.gov (United States)

    Larson, Elaine L; Cohen, Bevin; Baxter, Kathleen A

    2012-11-01

    Minimal research has been published evaluating the effectiveness of hand hygiene delivery systems (ie, rubs, foams, or wipes) at removing viruses from hands. The purposes of this study were to determine the effect of several alcohol-based hand sanitizers in removing influenza A (H1N1) virus, and to compare the effectiveness of foam, gel, and hand wipe products. Hands of 30 volunteers were inoculated with H1N1 and randomized to treatment with foam, gel, or hand wipe applied to half of each volunteer's finger pads. The log(10) count of each subject's treated and untreated finger pads were averaged. Log(10) reductions were calculated from these differences and averaged within treatment group. Between-treatment analysis compared changes from the untreated finger pads using analysis of covariance with treatment as a factor and the average log(10) untreated finger pads as the covariate. Log(10) counts on control finger pads were 2.7-5.3 log(10) of the 50% infectious dose for tissue culture (TCID(50)/0.1 mL) (mean, 3.8 ± 0.5 log(10) TCID(50)/0.1 mL), and treated finger pad counts for all test products were 0.5-1.9 log(10) TCID(50)/0.1 mL (mean, 0.53 ± 0.17 log(10) TCID(50)/0.1 mL). Treatments with all products resulted in a significant reduction in viral titers (>3 logs) at their respective exposure times that were statistically comparable. All 3 delivery systems (foam, gel, and wipe) produced significantly reduced viral counts on hands. Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  12. MO-D-BRB-02: SBRT Treatment Planning and Delivery

    International Nuclear Information System (INIS)

    Yang, Y.

    2016-01-01

    Increased use of SBRT and hypofractionation in radiation oncology practice has posted a number of challenges to medical physicist, ranging from planning, image-guided patient setup and on-treatment monitoring, to quality assurance (QA) and dose delivery. This symposium is designed to provide current knowledge necessary for the safe and efficient implementation of SBRT in various linac platforms, including the emerging digital linacs equipped with high dose rate FFF beams. Issues related to 4D CT, PET and MRI simulations, 3D/4D CBCT guided patient setup, real-time image guidance during SBRT dose delivery using gated/un-gated VMAT/IMRT, and technical advancements in QA of SBRT (in particular, strategies dealing with high dose rate FFF beams) will be addressed. The symposium will help the attendees to gain a comprehensive understanding of the SBRT workflow and facilitate their clinical implementation of the state-of-art imaging and planning techniques. Learning Objectives: Present background knowledge of SBRT, describe essential requirements for safe implementation of SBRT, and discuss issues specific to SBRT treatment planning and QA. Update on the use of multi-dimensional and multi-modality imaging for reliable guidance of SBRT. Discuss treatment planning and QA issues specific to SBRT. Provide a comprehensive overview of emerging digital linacs and summarize the key geometric and dosimetric features of the new generation of linacs for substantially improved SBRT. NIH/NCI; Varian Medical Systems; F. Yin, Duke University has a research agreement with Varian Medical Systems. In addition to research grant, I had a technology license agreement with Varian Medical Systems

  13. MO-D-BRB-02: SBRT Treatment Planning and Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y. [Stanford University Cancer Center (United States)

    2016-06-15

    Increased use of SBRT and hypofractionation in radiation oncology practice has posted a number of challenges to medical physicist, ranging from planning, image-guided patient setup and on-treatment monitoring, to quality assurance (QA) and dose delivery. This symposium is designed to provide current knowledge necessary for the safe and efficient implementation of SBRT in various linac platforms, including the emerging digital linacs equipped with high dose rate FFF beams. Issues related to 4D CT, PET and MRI simulations, 3D/4D CBCT guided patient setup, real-time image guidance during SBRT dose delivery using gated/un-gated VMAT/IMRT, and technical advancements in QA of SBRT (in particular, strategies dealing with high dose rate FFF beams) will be addressed. The symposium will help the attendees to gain a comprehensive understanding of the SBRT workflow and facilitate their clinical implementation of the state-of-art imaging and planning techniques. Learning Objectives: Present background knowledge of SBRT, describe essential requirements for safe implementation of SBRT, and discuss issues specific to SBRT treatment planning and QA. Update on the use of multi-dimensional and multi-modality imaging for reliable guidance of SBRT. Discuss treatment planning and QA issues specific to SBRT. Provide a comprehensive overview of emerging digital linacs and summarize the key geometric and dosimetric features of the new generation of linacs for substantially improved SBRT. NIH/NCI; Varian Medical Systems; F. Yin, Duke University has a research agreement with Varian Medical Systems. In addition to research grant, I had a technology license agreement with Varian Medical Systems.

  14. Assessing family planning service-delivery skills in Kenya.

    Science.gov (United States)

    Valadez, J J; Transgrud, R; Mbugua, M; Smith, T

    1997-06-01

    This report demonstrates the use of Lot Quality Assurance Sampling (LQAS) to evaluate the technical competence of two cohorts of family planning service providers in Kenya trained with a new curriculum. One cohort had just finished training within two months of the study. The other cohort was the first group trained with the new curriculum about one year before the study. LQAS was adapted from industrial and other public health applications to assess both the individual competence of 30 service providers and the competence of each cohort. Results show that Cohorts One and Two did not differ markedly in the number of tasks needing improvement. However, both cohorts exhibited more tasks needing improvement in counseling skills as compared with physical examination skills or with all other skills. Care-givers who were not currently providing services accounted for most service-delivery problems. This result suggests that providers' use of their skills explains their ability to retain service-delivery skills learned in training to a greater degree than does the amount of time elapsed since they were trained. LQAS proved to be a rapid, easy-to-use empirical method for management decisionmaking for improvement of a family planning training curriculum and services.

  15. Tank waste remediation system retrieval and disposal mission waste feed delivery plan

    International Nuclear Information System (INIS)

    Potter, R.D.

    1998-01-01

    This document is a plan presenting the objectives, organization, and management and technical approaches for the Waste Feed Delivery (WFD) Program. This WFD Plan focuses on the Tank Waste Remediation System (TWRS) Project's Waste Retrieval and Disposal Mission

  16. Sci—Thur PM: Planning and Delivery — 03: Automated delivery and quality assurance of a modulated electron radiation therapy plan

    International Nuclear Information System (INIS)

    Connell, T; Papaconstadopoulos, P; Alexander, A; Serban, M; Devic, S; Seuntjens, J

    2014-01-01

    Modulated electron radiation therapy (MERT) offers the potential to improve healthy tissue sparing through increased dose conformity. Challenges remain, however, in accurate beamlet dose calculation, plan optimization, collimation method and delivery accuracy. In this work, we investigate the accuracy and efficiency of an end-to-end MERT plan and automated-delivery workflow for the electron boost portion of a previously treated whole breast irradiation case. Dose calculations were performed using Monte Carlo methods and beam weights were determined using a research-based treatment planning system capable of inverse optimization. The plan was delivered to radiochromic film placed in a water equivalent phantom for verification, using an automated motorized tertiary collimator. The automated delivery, which covered 4 electron energies, 196 subfields and 6183 total MU was completed in 25.8 minutes, including 6.2 minutes of beam-on time with the remainder of the delivery time spent on collimator leaf motion and the automated interfacing with the accelerator in service mode. The delivery time could be reduced by 5.3 minutes with minor electron collimator modifications and the beam-on time could be reduced by and estimated factor of 2–3 through redesign of the scattering foils. Comparison of the planned and delivered film dose gave 3%/3 mm gamma pass rates of 62.1, 99.8, 97.8, 98.3, and 98.7 percent for the 9, 12, 16, 20 MeV, and combined energy deliveries respectively. Good results were also seen in the delivery verification performed with a MapCHECK 2 device. The results showed that accurate and efficient MERT delivery is possible with current technologies

  17. SU-E-T-151: Breathing Synchronized Delivery (BSD) Planning for RapicArc Treatment

    International Nuclear Information System (INIS)

    Lu, W; Chen, M; Jiang, S

    2015-01-01

    Purpose: To propose a workflow for breathing synchronized delivery (BSD) planning for RapicArc treatment. Methods: The workflow includes three stages: screening/simulation, planning, and delivery. In the screening/simulation stage, a 4D CT with the corresponding breathing pattern is acquired for each of the selected patients, who are able to follow their own breathing pattern. In the planning stage, one breathing phase is chosen as the reference, and contours are delineated on the reference image. Deformation maps to other phases are performed along with contour propagation. Based on the control points of the initial 3D plan for the reference phase and the respiration trace, the correlation with respiration phases, the leaf sequence and gantry angles is determined. The beamlet matrices are calculated with the corresponding breathing phase and deformed to the reference phase. Using the 4D dose evaluation tool and the original 3D plan DVHs criteria, the leaf sequence is further optimized to meet the planning objectives and the machine constraints. In the delivery stage, the patients are instructed to follow the programmed breathing patterns of their own, and all other parts are the same as the conventional Rapid-Arc delivery. Results: Our plan analysis is based on comparison of the 3D plan with a static target (SD), 3D plan with motion delivery (MD), and the BSD plan. Cyclic motion of range 0 cm to 3 cm was simulated for phantoms and lung CT. The gain of the BSD plan over MD is significant and concordant for both simulation and lung 4DCT, indicating the benefits of 4D planning. Conclusion: Our study shows that the BSD plan can approach the SD plan quality. However, such BSD scheme relies on the patient being able to follow the same breathing curve that is used in the planning stage during radiation delivery. Funded by Varian Medical Systems

  18. Planned home compared with planned hospital births: Mode of delivery and Perinatal mortality rates, an observational study

    NARCIS (Netherlands)

    Kooy, J. (Jacoba); E. Birnie (Erwin); S. Denktaş (Semiha); E.A.P. Steegers (Eric); G.J. Bonsel (Gouke)

    2017-01-01

    textabstractBackground: To compare the mode of delivery between planned home versus planned hospital births and to determine if differences in intervention rates could be interpreted as over- or undertreatment. Methods: Intervention and perinatal mortality rates were obtained for 679,952 low-risk

  19. Planned and unplanned deliveries at home: implications of a changing ratio.

    Science.gov (United States)

    Murphy, J F; Dauncey, M; Gray, O P; Chalmers, I

    1984-05-12

    The observation that perinatal mortality among babies delivered at home has tended to increase beyond that among babies delivered in consultant obstetric units has caused alarm and prompted recommendations that delivery at home should be further phased out. With data derived from the Cardiff Births Survey the possibility was investigated that this trend might reflect a changing ratio of planned to unplanned domiciliary births. At the beginning of the 1970s deliveries at home that were planned to be so outnumbered those that were not by nearly five to one. By 1979 unplanned deliveries at home outnumbered planned deliveries. The characteristics of the mothers, the health care they received, and the outcome of delivery differed strikingly between planned and unplanned deliveries at home. It is concluded, firstly, that every year the maternity services must try to meet the various needs of about 2000 women in England and Wales who give birth at home without planning to do so; and, secondly, that the heterogeneity of births at home and in hospital will continue to obstruct the search for unbiased estimates of the risks attributable to delivery in specialist obstetric units, general practitioner units, and at home.

  20. Planned and unplanned deliveries at home: implications of a changing ratio.

    OpenAIRE

    Murphy, J F; Dauncey, M; Gray, O P; Chalmers, I

    1984-01-01

    The observation that perinatal mortality among babies delivered at home has tended to increase beyond that among babies delivered in consultant obstetric units has caused alarm and prompted recommendations that delivery at home should be further phased out. With data derived from the Cardiff Births Survey the possibility was investigated that this trend might reflect a changing ratio of planned to unplanned domiciliary births. At the beginning of the 1970s deliveries at home that were planned...

  1. The effects of tumor motion on planning and delivery of respiratory-gated IMRT

    International Nuclear Information System (INIS)

    Hugo, Geoffrey D.; Agazaryan, Nzhde; Solberg, Timothy D.

    2003-01-01

    The purpose of this study is to investigate the effects of object motion on the planning and delivery of IMRT. Two phantoms containing objects were imaged using CT under a variety of motion conditions. The effects of object motion on axial CT acquisition with and without gating were assessed qualitatively and quantitatively. Measurements of effective slice width and position for the CT scans were made. Mutual information image fusion was adapted for use as a quantitative measure of object deformation in CT images. IMRT plans were generated on the CT scans of the moving and gated object images. These plans were delivered with motion, with and without gating, and the delivery error between the moving deliveries and a nonmoving delivery was assessed using a scalable vector-based index. Motion during CT acquisition produces motion artifact, object deformation, and object mispositioning, which can be substantially reduced with gating. Objects that vary in cross section in the direction of motion exhibit the most deformation in CT images. Mutual information provides a useful quantitative estimate of object deformation. The delivery of IMRT in the presence of target motion significantly alters the delivered dose distribution in relation to the planned distribution. The utilization of gating for IMRT treatment, including imaging, planning, and delivery, significantly reduces the errors introduced by object motion

  2. Double Shell Tanks (DST) and Waste Feed Delivery Project Management Quality Affecting Procedures Management Plan

    International Nuclear Information System (INIS)

    LUND, D.P.

    2000-01-01

    The purpose of the Double Shell Tanks (DST) and Waste Feed Delivery (WFD) Management Assessment Plan is to define how management assessments within DST h WFD will be conducted. The plan as written currently includes only WFD Project assessment topics. Other DST and WFD group assessment topics will be added in future revisions

  3. Treatment planning for SBRT using automated field delivery: A case study

    International Nuclear Information System (INIS)

    Ritter, Timothy A.; Owen, Dawn; Brooks, Cassandra M.; Stenmark, Matthew H.

    2015-01-01

    Stereotactic body radiation therapy (SBRT) treatment planning and delivery can be accomplished using a variety of techniques that achieve highly conformal dose distributions. Herein, we describe a template-based automated treatment field approach that enables rapid delivery of more than 20 coplanar fields. A case study is presented to demonstrate how modest adaptations to traditional SBRT planning can be implemented to take clinical advantage of this technology. Treatment was planned for a left-sided lung lesion adjacent to the chest wall using 25 coplanar treatment fields spaced at 11° intervals. The plan spares the contralateral lung and is in compliance with the conformality standards set forth in Radiation Therapy and Oncology Group protocol 0915, and the dose tolerances found in the report of the American Association of Physicists in Medicine Task Group 101. Using a standard template, treatment planning was accomplished in less than 20 minutes, and each 10 Gy fraction was delivered in approximately 5.4 minutes. For those centers equipped with linear accelerators capable of automated treatment field delivery, the use of more than 20 coplanar fields is a viable SBRT planning approach and yields excellent conformality and quality combined with rapid planning and treatment delivery. Although the case study discusses a laterally located lung lesion, this technique can be applied to centrally located tumors with similar results

  4. Foam patterns

    Science.gov (United States)

    Chaudhry, Anil R; Dzugan, Robert; Harrington, Richard M; Neece, Faurice D; Singh, Nipendra P; Westendorf, Travis

    2013-11-26

    A method of creating a foam pattern comprises mixing a polyol component and an isocyanate component to form a liquid mixture. The method further comprises placing a temporary core having a shape corresponding to a desired internal feature in a cavity of a mold and inserting the mixture into the cavity of the mold so that the mixture surrounds a portion of the temporary core. The method optionally further comprises using supporting pins made of foam to support the core in the mold cavity, with such pins becoming integral part of the pattern material simplifying subsequent processing. The method further comprises waiting for a predetermined time sufficient for a reaction from the mixture to form a foam pattern structure corresponding to the cavity of the mold, wherein the foam pattern structure encloses a portion of the temporary core and removing the temporary core from the pattern independent of chemical leaching.

  5. Forming foam structures with carbon foam substrates

    Science.gov (United States)

    Landingham, Richard L.; Satcher, Jr., Joe H.; Coronado, Paul R.; Baumann, Theodore F.

    2012-11-06

    The invention provides foams of desired cell sizes formed from metal or ceramic materials that coat the surfaces of carbon foams which are subsequently removed. For example, metal is located over a sol-gel foam monolith. The metal is melted to produce a metal/sol-gel composition. The sol-gel foam monolith is removed, leaving a metal foam.

  6. Foam Microrheology

    International Nuclear Information System (INIS)

    KRAYNIK, ANDREW M.; LOEWENBERG, MICHAEL; REINELT, DOUGLAS A.

    1999-01-01

    The microrheology of liquid foams is discussed for two different regimes: static equilibrium where the capillary number Ca is zero, and the viscous regime where viscosity and surface tension are important and Ca is finite. The Surface Evolver is used to calculate the equilibrium structure of wet Kelvin foams and dry soap froths with random structure, i.e., topological disorder. The distributions of polyhedra and faces are compared with the experimental data of Matzke. Simple shearing flow of a random foam under quasistatic conditions is also described. Viscous phenomena are explored in the context of uniform expansion of 2D and 3D foams at low Reynolds number. Boundary integral methods are used to calculate the influence of Ca on the evolution of foam microstructure, which includes bubble shape and the distribution of liquid between films, Plateau borders, and (in 3D) the nodes where Plateau borders meet. The micromechanical point of view guides the development of structure-property-processing relationships for foams

  7. Workforce planning and development in times of delivery system transformation.

    Science.gov (United States)

    Pittman, Patricia; Scully-Russ, Ellen

    2016-09-23

    As implementation of the US Affordable Care Act (ACA) advances, many domestic health systems are considering major changes in how the healthcare workforce is organized. The purpose of this study is to explore the dynamic processes and interactions by which workforce planning and development (WFPD) is evolving in this new environment. Informed by the theory of loosely coupled systems (LCS), we use a case study design to examine how workforce changes are being managed in Kaiser Permanente and Montefiore Health System. We conducted site visits with in-depth interviews with 8 to 10 stakeholders in each organization. Both systems demonstrate a concern for the impact of change on their workforce and have made commitments to avoid outsourcing and layoffs. Central workforce planning mechanisms have been replaced with strategies to integrate various stakeholders and units in alignment with strategic growth plans. Features of this new approach include early and continuous engagement of labor in innovation; the development of intermediary sense-making structures to garner resources, facilitate plans, and build consensus; and a whole system perspective, rather than a focus on single professions. We also identify seven principles underlying the WFPD processes in these two cases that can aid in development of a new and more adaptive workforce strategy in healthcare. Since passage of the ACA, healthcare systems are becoming larger and more complex. Insights from these case studies suggest that while organizational history and structure determined different areas of emphasis, our results indicate that large-scale system transformations in healthcare can be managed in ways that enhance the skills and capacities of the workforce. Our findings merit attention, not just by healthcare administrators and union leaders, but by policymakers and scholars interested in making WFPD policies at a state and national level more responsive.

  8. IMRT, IGRT, SBRT - Advances in the Treatment Planning and Delivery of Radiotherapy

    CERN Document Server

    Meyer, JL

    2011-01-01

    Over the last 4 years, IMRT, IGRT, SBRT: Advances in the Treatment Planning and Delivery of Radiotherapy has become a standard reference in the field. During this time, however, significant progress in high-precision technologies for the planning and delivery of radiotherapy in cancer treatment has called for a second edition to include these new developments. Thoroughly updated and extended, this new edition offers a comprehensive guide and overview of these new technologies and the many clinical treatment programs that bring them into practical use. Advances in intensity-modulated radiothera

  9. Combined Inter- and Intrafractional Plan Adaptation Using Fraction Partitioning in Magnetic Resonance-guided Radiotherapy Delivery.

    Science.gov (United States)

    Lagerwaard, Frank; Bohoudi, Omar; Tetar, Shyama; Admiraal, Marjan A; Rosario, Tezontl S; Bruynzeel, Anna

    2018-04-05

    Magnetic resonance-guided radiation therapy (MRgRT) not only allows for superior soft-tissue setup and online MR-guidance during delivery but also for inter-fractional plan re-optimization or adaptation. This plan adaptation involves repeat MR imaging, organs at risk (OARs) re-contouring, plan prediction (i.e., recalculating the baseline plan on the anatomy of that moment), plan re-optimization, and plan quality assurance. In contrast, intrafractional plan adaptation cannot be simply performed by pausing delivery at any given moment, adjusting contours, and re-optimization because of the complex and composite nature of deformable dose accumulation. To overcome this limitation, we applied a practical workaround by partitioning treatment fractions, each with half the original fraction dose. In between successive deliveries, the patient remained in the treatment position and all steps of the initial plan adaptation were repeated. Thus, this second re-optimization served as an intrafractional plan adaptation at 50% of the total delivery. The practical feasibility of this partitioning approach was evaluated in a patient treated with MRgRT for locally advanced pancreatic cancer (LAPC). MRgRT was delivered in 40Gy in 10 fractions, with two fractions scheduled successively on each treatment day. The contoured gross tumor volume (GTV) was expanded by 3 mm, excluding parts of the OARs within this expansion to derive the planning target volume for daily re-optimization (PTV OPT ). The baseline GTVV 95%  achieved in this patient was 80.0% to adhere to the high-dose constraints for the duodenum, stomach, and bowel (V 33 Gy ViewRay Inc, Mountain View, USA) using video-assisted breath-hold in shallow inspiration. The dual plan adaptation resulted, for each partitioned fraction, in the generation of Plan PREDICTED1 , Plan RE-OPTIMIZED1  (inter-fractional adaptation), Plan PREDICTED2 , and Plan RE-OPTIMIZED2  (intrafractional adaptation). An offline analysis was

  10. Planned Cesarean Delivery at Term and Adverse Outcomes in Childhood Health

    Science.gov (United States)

    Black, Mairead; Bhattacharya, Siladitya; Philip, Sam; Norman, Jane E.; McLernon, David J.

    2016-01-01

    Importance Planned cesarean delivery comprises a significant proportion of births globally, with combined rates of planned and unscheduled cesarean delivery in a number of regions approaching 50%. Observational studies have shown that offspring born by cesarean delivery are at increased risk of ill health in childhood, but these studies have been unable to adjust for some key confounding variables. Additionally, risk of death beyond the neonatal period has not yet been reported for offspring born by planned cesarean delivery. Objective To investigate the relationship between planned cesarean delivery and offspring health problems or death in childhood. Design, Setting, and Participants Population-based data-linkage study of 321 287 term singleton first-born offspring born in Scotland, United Kingdom, between 1993 and 2007, with follow-up until February 2015. Exposures Offspring born by planned cesarean delivery in a first pregnancy were compared with offspring born by unscheduled cesarean delivery and with offspring delivered vaginally. Main Outcomes and Measures The primary outcome was asthma requiring hospital admission; secondary outcomes were salbutamol inhaler prescription at age 5 years, obesity at age 5 years, inflammatory bowel disease, type 1 diabetes, cancer, and death. Results Compared with offspring born by unscheduled cesarean delivery (n = 56 015 [17.4%]), those born by planned cesarean delivery (12 355 [3.8%]) were at no significantly different risk of asthma requiring hospital admission, salbutamol inhaler prescription at age 5 years, obesity at age 5 years, inflammatory bowel disease, cancer, or death but were at increased risk of type 1 diabetes (0.66% vs 0.44%; difference, 0.22% [95% CI, 0.13%-0.31%]; adjusted hazard ratio [HR], 1.35 [95% CI, 1.05-1.75]). In comparison with children born vaginally (n = 252 917 [78.7%]), offspring born by planned cesarean delivery were at increased risk of asthma requiring hospital admission (3.73% vs 3

  11. Quality assurance for online adapted treatment plans: Benchmarking and delivery monitoring simulation

    International Nuclear Information System (INIS)

    Li, Taoran; Wu, Qiuwen; Yang, Yun; Rodrigues, Anna; Yin, Fang-Fang; Jackie Wu, Q.

    2015-01-01

    Purpose: An important challenge facing online adaptive radiation therapy is the development of feasible and efficient quality assurance (QA). This project aimed to validate the deliverability of online adapted plans and develop a proof-of-concept online delivery monitoring system for online adaptive radiation therapy QA. Methods: The first part of this project benchmarked automatically online adapted prostate treatment plans using traditional portal dosimetry IMRT QA. The portal dosimetry QA results of online adapted plans were compared to original (unadapted) plans as well as randomly selected prostate IMRT plans from our clinic. In the second part, an online delivery monitoring system was designed and validated via a simulated treatment with intentional multileaf collimator (MLC) errors. This system was based on inputs from the dynamic machine information (DMI), which continuously reports actual MLC positions and machine monitor units (MUs) at intervals of 50 ms or less during delivery. Based on the DMI, the system performed two levels of monitoring/verification during the delivery: (1) dynamic monitoring of cumulative fluence errors resulting from leaf position deviations and visualization using fluence error maps (FEMs); and (2) verification of MLC positions against the treatment plan for potential errors in MLC motion and data transfer at each control point. Validation of the online delivery monitoring system was performed by introducing intentional systematic MLC errors (ranging from 0.5 to 2 mm) to the DMI files for both leaf banks. These DMI files were analyzed by the proposed system to evaluate the system’s performance in quantifying errors and revealing the source of errors, as well as to understand patterns in the FEMs. In addition, FEMs from 210 actual prostate IMRT beams were analyzed using the proposed system to further validate its ability to catch and identify errors, as well as establish error magnitude baselines for prostate IMRT delivery

  12. Quality assurance for online adapted treatment plans: Benchmarking and delivery monitoring simulation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Taoran, E-mail: taoran.li.duke@gmail.com; Wu, Qiuwen; Yang, Yun; Rodrigues, Anna; Yin, Fang-Fang; Jackie Wu, Q. [Department of Radiation Oncology, Duke University Medical Center Durham, North Carolina 27710 (United States)

    2015-01-15

    Purpose: An important challenge facing online adaptive radiation therapy is the development of feasible and efficient quality assurance (QA). This project aimed to validate the deliverability of online adapted plans and develop a proof-of-concept online delivery monitoring system for online adaptive radiation therapy QA. Methods: The first part of this project benchmarked automatically online adapted prostate treatment plans using traditional portal dosimetry IMRT QA. The portal dosimetry QA results of online adapted plans were compared to original (unadapted) plans as well as randomly selected prostate IMRT plans from our clinic. In the second part, an online delivery monitoring system was designed and validated via a simulated treatment with intentional multileaf collimator (MLC) errors. This system was based on inputs from the dynamic machine information (DMI), which continuously reports actual MLC positions and machine monitor units (MUs) at intervals of 50 ms or less during delivery. Based on the DMI, the system performed two levels of monitoring/verification during the delivery: (1) dynamic monitoring of cumulative fluence errors resulting from leaf position deviations and visualization using fluence error maps (FEMs); and (2) verification of MLC positions against the treatment plan for potential errors in MLC motion and data transfer at each control point. Validation of the online delivery monitoring system was performed by introducing intentional systematic MLC errors (ranging from 0.5 to 2 mm) to the DMI files for both leaf banks. These DMI files were analyzed by the proposed system to evaluate the system’s performance in quantifying errors and revealing the source of errors, as well as to understand patterns in the FEMs. In addition, FEMs from 210 actual prostate IMRT beams were analyzed using the proposed system to further validate its ability to catch and identify errors, as well as establish error magnitude baselines for prostate IMRT delivery

  13. Quality assurance for online adapted treatment plans: benchmarking and delivery monitoring simulation.

    Science.gov (United States)

    Li, Taoran; Wu, Qiuwen; Yang, Yun; Rodrigues, Anna; Yin, Fang-Fang; Jackie Wu, Q

    2015-01-01

    An important challenge facing online adaptive radiation therapy is the development of feasible and efficient quality assurance (QA). This project aimed to validate the deliverability of online adapted plans and develop a proof-of-concept online delivery monitoring system for online adaptive radiation therapy QA. The first part of this project benchmarked automatically online adapted prostate treatment plans using traditional portal dosimetry IMRT QA. The portal dosimetry QA results of online adapted plans were compared to original (unadapted) plans as well as randomly selected prostate IMRT plans from our clinic. In the second part, an online delivery monitoring system was designed and validated via a simulated treatment with intentional multileaf collimator (MLC) errors. This system was based on inputs from the dynamic machine information (DMI), which continuously reports actual MLC positions and machine monitor units (MUs) at intervals of 50 ms or less during delivery. Based on the DMI, the system performed two levels of monitoring/verification during the delivery: (1) dynamic monitoring of cumulative fluence errors resulting from leaf position deviations and visualization using fluence error maps (FEMs); and (2) verification of MLC positions against the treatment plan for potential errors in MLC motion and data transfer at each control point. Validation of the online delivery monitoring system was performed by introducing intentional systematic MLC errors (ranging from 0.5 to 2 mm) to the DMI files for both leaf banks. These DMI files were analyzed by the proposed system to evaluate the system's performance in quantifying errors and revealing the source of errors, as well as to understand patterns in the FEMs. In addition, FEMs from 210 actual prostate IMRT beams were analyzed using the proposed system to further validate its ability to catch and identify errors, as well as establish error magnitude baselines for prostate IMRT delivery. Online adapted plans were

  14. Improving IMRT delivery efficiency with reweighted L1-minimization for inverse planning

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hojin [Department of Radiation Oncology, Stanford University, Stanford, California 94305-5847 and Department of Electrical Engineering, Stanford University, Stanford, California 94305-9505 (United States); Becker, Stephen [Laboratoire Jacques-Louis Lions, Universite Pierre et Marie Curie, Paris 6, 75005 France (France); Lee, Rena; Lee, Soonhyouk [Department of Radiation Oncology, School of Medicine, Ewha Womans University, Seoul 158-710 (Korea, Republic of); Shin, Sukyoung [Medtronic CV RDN R and D, Santa Rosa, California 95403 (United States); Candes, Emmanuel [Department of Statistics, Stanford University, Stanford, California 94305-4065 (United States); Xing Lei; Li Ruijiang [Department of Radiation Oncology, Stanford University, Stanford, California 94305-5304 (United States)

    2013-07-15

    Purpose: This study presents an improved technique to further simplify the fluence-map in intensity modulated radiation therapy (IMRT) inverse planning, thereby reducing plan complexity and improving delivery efficiency, while maintaining the plan quality.Methods: First-order total-variation (TV) minimization (min.) based on L1-norm has been proposed to reduce the complexity of fluence-map in IMRT by generating sparse fluence-map variations. However, with stronger dose sparing to the critical structures, the inevitable increase in the fluence-map complexity can lead to inefficient dose delivery. Theoretically, L0-min. is the ideal solution for the sparse signal recovery problem, yet practically intractable due to its nonconvexity of the objective function. As an alternative, the authors use the iteratively reweighted L1-min. technique to incorporate the benefits of the L0-norm into the tractability of L1-min. The weight multiplied to each element is inversely related to the magnitude of the corresponding element, which is iteratively updated by the reweighting process. The proposed penalizing process combined with TV min. further improves sparsity in the fluence-map variations, hence ultimately enhancing the delivery efficiency. To validate the proposed method, this work compares three treatment plans obtained from quadratic min. (generally used in clinic IMRT), conventional TV min., and our proposed reweighted TV min. techniques, implemented by a large-scale L1-solver (template for first-order conic solver), for five patient clinical data. Criteria such as conformation number (CN), modulation index (MI), and estimated treatment time are employed to assess the relationship between the plan quality and delivery efficiency.Results: The proposed method yields simpler fluence-maps than the quadratic and conventional TV based techniques. To attain a given CN and dose sparing to the critical organs for 5 clinical cases, the proposed method reduces the number of segments

  15. Improving IMRT delivery efficiency with reweighted L1-minimization for inverse planning

    International Nuclear Information System (INIS)

    Kim, Hojin; Becker, Stephen; Lee, Rena; Lee, Soonhyouk; Shin, Sukyoung; Candès, Emmanuel; Xing Lei; Li Ruijiang

    2013-01-01

    Purpose: This study presents an improved technique to further simplify the fluence-map in intensity modulated radiation therapy (IMRT) inverse planning, thereby reducing plan complexity and improving delivery efficiency, while maintaining the plan quality.Methods: First-order total-variation (TV) minimization (min.) based on L1-norm has been proposed to reduce the complexity of fluence-map in IMRT by generating sparse fluence-map variations. However, with stronger dose sparing to the critical structures, the inevitable increase in the fluence-map complexity can lead to inefficient dose delivery. Theoretically, L0-min. is the ideal solution for the sparse signal recovery problem, yet practically intractable due to its nonconvexity of the objective function. As an alternative, the authors use the iteratively reweighted L1-min. technique to incorporate the benefits of the L0-norm into the tractability of L1-min. The weight multiplied to each element is inversely related to the magnitude of the corresponding element, which is iteratively updated by the reweighting process. The proposed penalizing process combined with TV min. further improves sparsity in the fluence-map variations, hence ultimately enhancing the delivery efficiency. To validate the proposed method, this work compares three treatment plans obtained from quadratic min. (generally used in clinic IMRT), conventional TV min., and our proposed reweighted TV min. techniques, implemented by a large-scale L1-solver (template for first-order conic solver), for five patient clinical data. Criteria such as conformation number (CN), modulation index (MI), and estimated treatment time are employed to assess the relationship between the plan quality and delivery efficiency.Results: The proposed method yields simpler fluence-maps than the quadratic and conventional TV based techniques. To attain a given CN and dose sparing to the critical organs for 5 clinical cases, the proposed method reduces the number of segments

  16. Robotic path-finding in inverse treatment planning for stereotactic radiosurgery with continuous dose delivery

    Energy Technology Data Exchange (ETDEWEB)

    Vandewouw, Marlee M., E-mail: marleev@mie.utoronto.ca; Aleman, Dionne M. [Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8 (Canada); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario M5G 2M9 (Canada)

    2016-08-15

    Purpose: Continuous dose delivery in radiation therapy treatments has been shown to decrease total treatment time while improving the dose conformity and distribution homogeneity over the conventional step-and-shoot approach. The authors develop an inverse treatment planning method for Gamma Knife® Perfexion™ that continuously delivers dose along a path in the target. Methods: The authors’ method is comprised of two steps: find a path within the target, then solve a mixed integer optimization model to find the optimal collimator configurations and durations along the selected path. Robotic path-finding techniques, specifically, simultaneous localization and mapping (SLAM) using an extended Kalman filter, are used to obtain a path that travels sufficiently close to selected isocentre locations. SLAM is novelly extended to explore a 3D, discrete environment, which is the target discretized into voxels. Further novel extensions are incorporated into the steering mechanism to account for target geometry. Results: The SLAM method was tested on seven clinical cases and compared to clinical, Hamiltonian path continuous delivery, and inverse step-and-shoot treatment plans. The SLAM approach improved dose metrics compared to the clinical plans and Hamiltonian path continuous delivery plans. Beam-on times improved over clinical plans, and had mixed performance compared to Hamiltonian path continuous plans. The SLAM method is also shown to be robust to path selection inaccuracies, isocentre selection, and dose distribution. Conclusions: The SLAM method for continuous delivery provides decreased total treatment time and increased treatment quality compared to both clinical and inverse step-and-shoot plans, and outperforms existing path methods in treatment quality. It also accounts for uncertainty in treatment planning by accommodating inaccuracies.

  17. Robotic path-finding in inverse treatment planning for stereotactic radiosurgery with continuous dose delivery

    International Nuclear Information System (INIS)

    Vandewouw, Marlee M.; Aleman, Dionne M.; Jaffray, David A.

    2016-01-01

    Purpose: Continuous dose delivery in radiation therapy treatments has been shown to decrease total treatment time while improving the dose conformity and distribution homogeneity over the conventional step-and-shoot approach. The authors develop an inverse treatment planning method for Gamma Knife® Perfexion™ that continuously delivers dose along a path in the target. Methods: The authors’ method is comprised of two steps: find a path within the target, then solve a mixed integer optimization model to find the optimal collimator configurations and durations along the selected path. Robotic path-finding techniques, specifically, simultaneous localization and mapping (SLAM) using an extended Kalman filter, are used to obtain a path that travels sufficiently close to selected isocentre locations. SLAM is novelly extended to explore a 3D, discrete environment, which is the target discretized into voxels. Further novel extensions are incorporated into the steering mechanism to account for target geometry. Results: The SLAM method was tested on seven clinical cases and compared to clinical, Hamiltonian path continuous delivery, and inverse step-and-shoot treatment plans. The SLAM approach improved dose metrics compared to the clinical plans and Hamiltonian path continuous delivery plans. Beam-on times improved over clinical plans, and had mixed performance compared to Hamiltonian path continuous plans. The SLAM method is also shown to be robust to path selection inaccuracies, isocentre selection, and dose distribution. Conclusions: The SLAM method for continuous delivery provides decreased total treatment time and increased treatment quality compared to both clinical and inverse step-and-shoot plans, and outperforms existing path methods in treatment quality. It also accounts for uncertainty in treatment planning by accommodating inaccuracies.

  18. Use of plan quality degradation to evaluate tradeoffs in delivery efficiency and clinical plan metrics arising from IMRT optimizer and sequencer compromises

    Science.gov (United States)

    Wilkie, Joel R.; Matuszak, Martha M.; Feng, Mary; Moran, Jean M.; Fraass, Benedick A.

    2013-01-01

    Purpose: Plan degradation resulting from compromises made to enhance delivery efficiency is an important consideration for intensity modulated radiation therapy (IMRT) treatment plans. IMRT optimization and/or multileaf collimator (MLC) sequencing schemes can be modified to generate more efficient treatment delivery, but the effect those modifications have on plan quality is often difficult to quantify. In this work, the authors present a method for quantitative assessment of overall plan quality degradation due to tradeoffs between delivery efficiency and treatment plan quality, illustrated using comparisons between plans developed allowing different numbers of intensity levels in IMRT optimization and/or MLC sequencing for static segmental MLC IMRT plans. Methods: A plan quality degradation method to evaluate delivery efficiency and plan quality tradeoffs was developed and used to assess planning for 14 prostate and 12 head and neck patients treated with static IMRT. Plan quality was evaluated using a physician's predetermined “quality degradation” factors for relevant clinical plan metrics associated with the plan optimization strategy. Delivery efficiency and plan quality were assessed for a range of optimization and sequencing limitations. The “optimal” (baseline) plan for each case was derived using a clinical cost function with an unlimited number of intensity levels. These plans were sequenced with a clinical MLC leaf sequencer which uses >100 segments, assuring delivered intensities to be within 1% of the optimized intensity pattern. Each patient's optimal plan was also sequenced limiting the number of intensity levels (20, 10, and 5), and then separately optimized with these same numbers of intensity levels. Delivery time was measured for all plans, and direct evaluation of the tradeoffs between delivery time and plan degradation was performed. Results: When considering tradeoffs, the optimal number of intensity levels depends on the treatment

  19. A modified method of planning and delivery for dynamic multileaf collimator intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Dogan, Nesrin; Leybovich, Leonid B.; Sethi, Anil; Krasin, Matthew; Emami, Bahman

    2000-01-01

    Purpose: To develop a modified planning and delivery technique that reduces dose nonuniformity for tomographic delivery of intensity-modulated radiation therapy (IMRT). Methods and Materials: The NOMOS-CORVUS system delivers IMRT in a tomographic paradigm. This type of delivery is prone to create multiple dose nonuniformity regions at the arc abutment regions. The modified technique was based on the cyclical behavior of arc positions as a function of a target length. With the modified technique, two plans are developed for the same patient, one with the original target and the second with a slightly increased target length and the abutment regions shifted by ∼5 mm compared to the first plan. Each plan is designed to deliver half of the target prescription dose delivered on alternate days, resulting in periodic shifts of abutment regions. This method was experimentally tested in phantoms with and without intentionally introduced errors in couch indexing. Results: With the modified technique, the degree of dose nonuniformity was reduced. For example, with 1 mm error in couch indexing, the degree of dose nonuniformity changed from ∼25% to ∼12%. Conclusion: Use of the modified technique reduces dose nonuniformity due to periodic shifts of abutment regions during treatment delivery

  20. Planned home compared with planned hospital births: mode of delivery and Perinatal mortality rates, an observational study.

    Science.gov (United States)

    van der Kooy, Jacoba; Birnie, Erwin; Denktas, Semiha; Steegers, Eric A P; Bonsel, Gouke J

    2017-06-08

    To compare the mode of delivery between planned home versus planned hospital births and to determine if differences in intervention rates could be interpreted as over- or undertreatment. Intervention and perinatal mortality rates were obtained for 679,952 low-risk women from the Dutch Perinatal Registry (2000-2007). Intervention was defined as operative vaginal delivery and/or caesarean section. Perinatal mortality was defined as the intrapartum and early neonatal mortality rate up to 7 days postpartum. Besides adjustment for maternal and care factors, we included for additional casemix adjustment: presence of congenital abnormality, small for gestational age, preterm birth, or low Apgar score. The techniques used were nested multiple stepwise logistic regression, and stratified analysis for separate risk groups. An intention-to-treat like analysis was performed. The intervention rate was lower in planned home compared to planned hospital births (10.9% 95% CI 10.8-11.0 vs. 13.8% 95% CI 13.6-13.9). Intended place of birth had significant impact on the likelihood to intervene after adjustment (planned homebirth (OR 0.77 95% CI. 0.75-0.78)). The mortality rate was lower in planned home births (0.15% vs. 0.18%). After adjustment, the interaction term home- intervention was significant (OR1.51 95% CI 1.25-1.84). In risk groups, a higher perinatal mortality rate was observed in planned home births. The potential presence of over- or under treatment as expressed by adjusted perinatal mortality differs per risk group. In planned home births especially multiparous women showed universally lower intervention rates. However, the benefit of substantially fewer interventions in the planned home group seems to be counterbalanced by substantially increased mortality if intervention occurs.

  1. Dose planning and dose delivery in radiation therapy

    International Nuclear Information System (INIS)

    Knoeoes, T.

    1991-01-01

    A method has been developed for calibration of CT-numbers to volumetric electron density distributions using tissue substitutes of known elemental composition and experimentally determined electron density. This information have been used in a dose calculation method based on photon and electron interaction processes. The method utilizes a convolution integral between the photon fluence matrix and dose distribution kernels. Inhomogeneous media are accounted for using the theorems of Fano and O'Connor for scaling dose distribution kernels in proportion to electron density. For clinical application of a calculated dose plan, a method for prediction of accelerator output have been developed. The methods gives the number of monitor units that has to be given to obtain a certain absorbed dose to a point inside an irregular, inhomogeneous object. The method for verification of dose distributions outlined in this study makes it possible to exclude the treatment related variance contributions, making an objective evaluation of dose calculations with experiments feasible. The methods for electron density determination, dose calculation and prediction of accelerator output discussed in this study will all contribute to an increased accuracy in the mean absorbed dose to the target volume. However, a substantial gain in the accuracy for the spatial absorbed dose distribution will also follow, especially using CT for mapping of electron density together with the dose calculation algorithm. (au)

  2. Pilot study on virtual imaging for patient information on radiotherapy planning and delivery

    International Nuclear Information System (INIS)

    Sulé-Suso, J.; Finney, S.; Bisson, J.; Hammersley, S.; Jassel, S.; Knight, R.; Hicks, C.; Sargeant, S.; Lam, K.-P.; Belcher, J.; Collins, D.; Bhana, R.; Adab, F.; O'Donovan, C.; Moloney, A.

    2015-01-01

    It is widely accepted that health professionals might sometimes underestimate cancer patients' needs for information on the complex process of radiotherapy (RT) planning and delivery. Furthermore, relatives might also feel excluded from the treatment of their loved ones. This pilot study was carried out in order to assess whether both patients and their relatives would welcome further information on RT planning and delivery using the virtual reality (VR) system VERT. One hundred and fifty patients with different types of cancer receiving radical RT were included in the study. Patients and relatives were shown using VERT on a one-to-one basis with an oncologist or a radiographer, a standard room where RT is given, a linear accelerator, and how RT is planned and delivered using their own planning CT Scans. Patients welcomed this information as it helped them to reduce their fears about RT. Relatives felt also more involved in the treatment of their loved one. The results obtained in this pilot study show that VR aids could become an important tool for delivering information on RT to both patients and relatives. - Highlights: • Virtual imaging helps patients to better understand RT planning and delivery. • Virtual imaging reduces the fear factor. • Virtual imaging improves patients and relatives satisfaction

  3. A new smoothing procedure to reduce delivery segments for static MLC-based IMRT planning

    International Nuclear Information System (INIS)

    Sun Xuepeng; Xia Ping

    2004-01-01

    In the application of pixel-based intensity-modulated radiation therapy (IMRT) using the step-and-shoot delivery method, one major difficulty is the prolonged delivery time. In this study, we present an integrated IMRT planning system that involves a simple smoothing method to reduce the complexity of the beam profiles. The system consists of three main steps: (a) an inverse planning process based on a least-square dose-based cost function; (b) smoothing of the intensity maps; (c) reoptimization of the segment weights. Step (a) obtains the best plan with the lowest cost value using a simulated annealing optimization algorithm with discrete intensity levels. Step (b) takes the intensity maps obtained from (a) and reduces the complexity of the maps by smoothing the adjacent beamlet intensities. During this process each beamlet is assigned a structure index based on anatomical information. A smoothing update is applied to average adjacent beamlets with the same index. To control the quality of the plan, a predefined clinical protocol is used as an acceptance criterion. The smoothing updates that violate the criterion are rejected. After the smoothing process, the segment weights are reoptimized in step (c) to further improve the plan quality. Three clinical cases were studied using this system: a medulloblastoma, a prostate cancer, and an oropharyngeal carcinoma. While the final plans demonstrate a degradation of the original plan quality, they still meet the plan acceptance criterion. On the other hand, the segment numbers or delivery times are reduced by 40%, 20%, and 20% for the three cases, respectively

  4. Project Delivery Acquisition and Contracting Plan for the Tank Farm Contractor

    International Nuclear Information System (INIS)

    MERCADO, L.C.

    2000-01-01

    This document is a plan presenting the process, strategies and approaches for vendor contracting by the Tank Farm Contractor. The plan focuses on contracting structures, practices, methods, and desired approaches in contracting. The U.S. Department of Energy (DOE), Office of River Protection (ORP) has contracted with the CH2M HILL Hanford Group, Inc. (CHG), as the Tank Farm Contractor (TFC), to support vitrification of Hanford Site tank waste by the Privatization Contractor. During Waste Feed Delivery Phase 1, waste will be retrieved from certain double-shell tanks and delivered to the Privatization Contractor to meet contract feed delivery requirements. Near-term project goals include upgrading infrastructure systems; retrieving and delivering the waste; and accepting the waste packages for interim onsite storage and disposal. Project Delivery includes individual projects assigned to provide the infrastructure and systems responsible to provide engineering, design, procurement, installation/construction, and testing/turnover of systems for retrieval of waste from Hanford double-shell tanks. This plan sets the requirements for projects work scope, contracting practices, structures, methods, and performance measurements. The plan is designed to integrate Life-Cycle Projects acquisitions and provide a consistent contracting approach. This effort will serve as a step improvement in contract reform implementing commercial practices into DOE projects

  5. Effect of MLC leaf width on the planning and delivery of SMLC IMRT using the CORVUS inverse treatment planning system

    International Nuclear Information System (INIS)

    Burmeister, Jay; McDermott, Patrick N.; Bossenberger, Todd; Ben-Josef, Edgar; Levin, Kenneth; Forman, Jeffrey D.

    2004-01-01

    This study investigates the influence of multileaf collimator (MLC) leaf width on intensity modulated radiation therapy (IMRT) plans delivered via the segmented multileaf collimator (SMLC) technique. IMRT plans were calculated using the Corvus treatment planning system for three brain, three prostate, and three pancreas cases using leaf widths of 0.5 and 1 cm. Resulting differences in plan quality and complexity are presented here. Plans calculated using a 1 cm leaf width were chosen over the 0.5 cm leaf width plans in seven out of nine cases based on clinical judgment. Conversely, optimization results revealed a superior objective function result for the 0.5 cm leaf width plans in seven out of the nine comparisons. The 1 cm leaf width objective function result was superior only for very large target volumes, indicating that expanding the solution space for plan optimization by using narrower leaves may result in a decreased probability of finding the global minimum. In the remaining cases, we can conclude that we are often not utilizing the objective function as proficiently as possible to meet our clinical goals. There was often no apparent clinically significant difference between the two plans, and in such cases the issue becomes one of plan complexity. A comparison of plan complexity revealed that the average 1 cm leaf width plan required roughly 60% fewer segments and over 40% fewer monitor units than required by 0.5 cm leaf width plans. This allows a significant decrease in whole body dose and total treatment time. For very complex IMRT plans, the treatment delivery time may affect the biologically effective dose. A clinically significant improvement in plan quality from using narrower leaves was evident only in cases with very small target volumes or those with concavities that are small with respect to the MLC leaf width. For the remaining cases investigated in this study, there was no clinical advantage to reducing the MLC leaf width from 1 to 0.5 cm. In

  6. Pre-clinical evaluation of an inverse planning module for segmental MLC based IMRT delivery

    International Nuclear Information System (INIS)

    Georg, Dietmar; Kroupa, Bernhard

    2002-01-01

    Phantom tests are performed for pre-clinical evaluation of a commercial inverse planning system (HELAX TMS, V 6.0) for segmented multileaf collimator (MLC) intensity modulated radiotherapy (IMRT) delivery. The optimization module has available two optimization algorithms: the target primary feasibility and the weighted feasibility algorithm, only the latter allows the user to specify weights for structures. In the first series, single beam tests are performed to evaluate the outcome of inverse planning in terms of plausibility for the following situations: oblique incidence, presence of inhomogeneities, multiple targets at different depths and multiple targets with different desired doses. Additionally, for these tests a manual plan is made for comparison. In the absence of organs at risk, both the optimization algorithms are found to assign the highest priority to low dose constraints for targets. In the second series, tests resembling clinical relevant configurations (simultaneous boost and concave target with critical organ) are performed with multiple beam arrangements in order to determine the impact of the system's configuration on inverse planning. It is found that the definition of certain segment number and segment size limitations does not largely compromise treatment plans when using multiple beams. On the other hand, these limitations are important for delivery efficiency and dosimetry. For the number of iterations and voxels per volume of interest, standard values in the system's configuration are considered to be sufficient. Additionally, it is demonstrated that precautions must be taken to precisely define treatment goals when using computerized treatment optimization. Similar phantom tests could be used for a direct dosimetric verification of all steps from inverse treatment planning to IMRT delivery. (note)

  7. The feasibility of using Pareto fronts for comparison of treatment planning systems and delivery techniques

    International Nuclear Information System (INIS)

    Ottosson, Rickard O.; Sjoestroem, David; Behrens, Claus F.; Karlsson, Anna; Engstroem, Per E.; Knoeoes, Tommy; Ceberg, Crister

    2009-01-01

    Pareto optimality is a concept that formalises the trade-off between a given set of mutually contradicting objectives. A solution is said to be Pareto optimal when it is not possible to improve one objective without deteriorating at least one of the other. A set of Pareto optimal solutions constitute the Pareto front. The Pareto concept applies well to the inverse planning process, which involves inherently contradictory objectives, high and uniform target dose on one hand, and sparing of surrounding tissue and nearby organs at risk (OAR) on the other. Due to the specific characteristics of a treatment planning system (TPS), treatment strategy or delivery technique, Pareto fronts for a given case are likely to differ. The aim of this study was to investigate the feasibility of using Pareto fronts as a comparative tool for TPSs, treatment strategies and delivery techniques. In order to sample Pareto fronts, multiple treatment plans with varying target conformity and dose sparing of OAR were created for a number of prostate and head and neck IMRT cases. The DVHs of each plan were evaluated with respect to target coverage and dose to relevant OAR. Pareto fronts were successfully created for all studied cases. The results did indeed follow the definition of the Pareto concept, i.e. dose sparing of the OAR could not be improved without target coverage being impaired or vice versa. Furthermore, various treatment techniques resulted in distinguished and well separated Pareto fronts. Pareto fronts may be used to evaluate a number of parameters within radiotherapy. Examples are TPS optimization algorithms, the variation between accelerators or delivery techniques and the degradation of a plan during the treatment planning process. The issue of designing a model for unbiased comparison of parameters with such large inherent discrepancies, e.g. different TPSs, is problematic and should be carefully considered

  8. The feasibility of using Pareto fronts for comparison of treatment planning systems and delivery techniques.

    Science.gov (United States)

    Ottosson, Rickard O; Engstrom, Per E; Sjöström, David; Behrens, Claus F; Karlsson, Anna; Knöös, Tommy; Ceberg, Crister

    2009-01-01

    Pareto optimality is a concept that formalises the trade-off between a given set of mutually contradicting objectives. A solution is said to be Pareto optimal when it is not possible to improve one objective without deteriorating at least one of the other. A set of Pareto optimal solutions constitute the Pareto front. The Pareto concept applies well to the inverse planning process, which involves inherently contradictory objectives, high and uniform target dose on one hand, and sparing of surrounding tissue and nearby organs at risk (OAR) on the other. Due to the specific characteristics of a treatment planning system (TPS), treatment strategy or delivery technique, Pareto fronts for a given case are likely to differ. The aim of this study was to investigate the feasibility of using Pareto fronts as a comparative tool for TPSs, treatment strategies and delivery techniques. In order to sample Pareto fronts, multiple treatment plans with varying target conformity and dose sparing of OAR were created for a number of prostate and head & neck IMRT cases. The DVHs of each plan were evaluated with respect to target coverage and dose to relevant OAR. Pareto fronts were successfully created for all studied cases. The results did indeed follow the definition of the Pareto concept, i.e. dose sparing of the OAR could not be improved without target coverage being impaired or vice versa. Furthermore, various treatment techniques resulted in distinguished and well separated Pareto fronts. Pareto fronts may be used to evaluate a number of parameters within radiotherapy. Examples are TPS optimization algorithms, the variation between accelerators or delivery techniques and the degradation of a plan during the treatment planning process. The issue of designing a model for unbiased comparison of parameters with such large inherent discrepancies, e.g. different TPSs, is problematic and should be carefully considered.

  9. Infiltrated carbon foam composites

    Science.gov (United States)

    Lucas, Rick D. (Inventor); Danford, Harry E. (Inventor); Plucinski, Janusz W. (Inventor); Merriman, Douglas J. (Inventor); Blacker, Jesse M. (Inventor)

    2012-01-01

    An infiltrated carbon foam composite and method for making the composite is described. The infiltrated carbon foam composite may include a carbonized carbon aerogel in cells of a carbon foam body and a resin is infiltrated into the carbon foam body filling the cells of the carbon foam body and spaces around the carbonized carbon aerogel. The infiltrated carbon foam composites may be useful for mid-density ablative thermal protection systems.

  10. Sci—Thur PM: Planning and Delivery — 06: Real-Time Interactive Treatment Planning

    International Nuclear Information System (INIS)

    Matthews, Q; Mestrovic, A; Otto, K

    2014-01-01

    Purpose: To describe and evaluate a novel system for generalized Real-Time Interactive Planning (RTIP) applied to head and neck (H and N) VMAT. Methods: The clinician interactively manipulates dose distributions using DVHs, isodoses, or rate of dose fall-off, which may be subjected to user-defined constraints. Dose is calculated using a fast Achievable Dose Estimate (ADE) algorithm, which simulates the limits of what can be achieved during treatment. After each manipulation contributing fluence elements are modified and the dose distribution updates in effectively real-time. For H and N VMAT planning, structure sets for 11 patients were imported into RTIP. Each dose distribution was interactively modified to minimize OAR dose while constraining target DVHs. The resulting RTIP DVHs were transferred to the Eclipse™ VMAT optimizer, and conventional VMAT optimization was performed. Results: Dose calculation and update times for the ADE algorithm ranged from 2.4 to 22.6 milliseconds, thus facilitating effectively real-time manipulation of dose distributions. For each of the 11 H and N VMAT cases, the RTIP process took ∼2–10 minutes. All RTIP plans exhibited acceptable PTV coverage, mean dose, and max dose. 10 of 11 RTIP plans achieved substantially improved sparing of one or more OARs without compromising dose to targets or other OARs. Importantly, 10 of the 11 RTIP plans required only one or two post-RTIP optimizations. Conclusions: RTIP is a novel system for manipulating and updating achievable dose distributions in real-time. H and N VMAT plans generated using RTIP demonstrate improved OAR sparing and planning efficiency. Disclosures: One author has a commercial interest in the presented materials

  11. Planned early delivery versus expectant management for hypertensive disorders from 34 weeks gestation to term.

    Science.gov (United States)

    Cluver, Catherine; Novikova, Natalia; Koopmans, Corine M; West, Helen M

    2017-01-15

    Hypertensive disorders in pregnancy are significant contributors to maternal and perinatal morbidity and mortality. These disorders include well-controlled chronic hypertension, gestational hypertension (pregnancy-induced hypertension) and mild pre-eclampsia. The definitive treatment for these disorders is planned early delivery and the alternative is to manage the pregnancy expectantly if severe uncontrolled hypertension is not present, with close maternal and fetal monitoring. There are benefits and risks associated with both, so it is important to establish the safest option. To assess the benefits and risks of a policy of planned early delivery versus a policy of expectant management in pregnant women with hypertensive disorders, at or near term (from 34 weeks onwards). We searched Cochrane Pregnancy and Childbirth Trials Register (12 January 2016) and reference lists of retrieved studies. Randomised trials of a policy of planned early delivery (by induction of labour or by caesarean section) compared with a policy of delayed delivery ("expectant management") for women with hypertensive disorders from 34 weeks' gestation. Cluster-randomised trials would have been eligible for inclusion in this review, but we found none.Studies using a quasi-randomised design are not eligible for inclusion in this review. Similarly, studies using a cross-over design are not eligible for inclusion, because they are not a suitable study design for investigating hypertensive disorders in pregnancy. Two review authors independently assessed eligibility and risks of bias. Two review authors independently extracted data. Data were checked for accuracy. We included five studies (involving 1819 women) in this review.There was a lower risk of composite maternal mortality and severe morbidity for women randomised to receive planned early delivery (risk ratio (RR) 0.69, 95% confidence interval (CI) 0.57 to 0.83, two studies, 1459 women (evidence graded high)). There were no clear

  12. Twin Birth Study: 2-year neurodevelopmental follow-up of the randomized trial of planned cesarean or planned vaginal delivery for twin pregnancy.

    Science.gov (United States)

    Asztalos, Elizabeth V; Hannah, Mary E; Hutton, Eileen K; Willan, Andrew R; Allen, Alexander C; Armson, B Anthony; Gafni, Amiram; Joseph, K S; Ohlsson, Arne; Ross, Susan; Sanchez, J Johanna; Mangoff, Kathryn; Barrett, Jon F R

    2016-03-01

    The Twin Birth Study randomized women with uncomplicated pregnancies, between 32(0/7)-38(6/7) weeks' gestation where the first twin was in cephalic presentation, to a policy of either a planned cesarean or planned vaginal delivery. The primary analysis showed that planned cesarean delivery did not increase or decrease the risk of fetal/neonatal death or serious neonatal morbidity as compared with planned vaginal delivery. This study presents the secondary outcome of death or neurodevelopmental delay at 2 years of age. A total of 4603 children from the initial cohort of 5565 fetuses/infants (83%) contributed to the outcome of death or neurodevelopmental delay. Surviving children were screened using the Ages and Stages Questionnaire with abnormal scores validated by a clinical neurodevelopmental assessment. The effect of planned cesarean vs planned vaginal delivery on death or neurodevelopmental delay was quantified using a logistic model to control for stratification variables and using generalized estimating equations to account for the nonindependence of twin births. Baseline maternal, pregnancy, and infant characteristics were similar. Mean age at assessment was 26 months. There was no significant difference in the outcome of death or neurodevelopmental delay: 5.99% in the planned cesarean vs 5.83% in the planned vaginal delivery group (odds ratio, 1.04; 95% confidence interval, 0.77-1.41; P = .79). A policy of planned cesarean delivery provides no benefit to children at 2 years of age compared with a policy of planned vaginal delivery in uncomplicated twin pregnancies between 32(0/7)-38(6/7)weeks' gestation where the first twin is in cephalic presentation. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. An annual employee education calendar as the capstone of educational assessment, planning, and delivery.

    Science.gov (United States)

    Morton, Paula G

    2005-01-01

    Staff development educators can better control their workload and provide a more comprehensive employee education program when the organization adopts a formal five-step process that culminates in the publication of an annual employee education calendar. This article describes the five steps of organization-wide learning needs assessment, resource allocation, priority setting, documentation of the educational plan, and calendar development, including elements and timelines. The annual calendar reflects involvement of staff throughout the facility in the identification, planning, and delivery of education programs. Its publication enhances staff and supervisors' awareness of learning opportunities. Its longer-range perspective assists managers and employees to better plan to meet learning needs and improves participation in staff development activities.

  14. Vision 20/20: Positron emission tomography in radiation therapy planning, delivery, and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Parodi, Katia, E-mail: Katia.parodi@physik.uni-muenchen.de [Faculty of Physics, Department of Medical Physics, Ludwig Maximilians University Munich, Munich 85748 (Germany)

    2015-12-15

    Positron emission tomography (PET) is increasingly considered as an effective imaging method to support several stages of radiation therapy. The combined usage of functional and morphological imaging in state-of-the-art PET/CT scanners is rapidly emerging to support the treatment planning process in terms of improved tumor delineation, and to assess the tumor response in follow-up investigations after or even during the course of fractionated therapy. Moreover, active research is being pursued on new tracers capable of providing different insights into tumor function, in order to identify areas of the planning volume which may require additional dosage for improved probability of tumor control. In this respect, major progresses in the next years will likely concern the development and clinical investigation of novel tracers and image processing techniques for reliable thresholding and segmentation, of treatment planning and beam delivery approaches integrating the PET imaging information, as well as improved multimodal clinical instrumentation such as PET/MR. But especially in the rapidly emerging case of ion beam therapy, the usage of PET is not only limited to the imaging of external tracers injected to the patient. In fact, a minor amount of positron emitters is formed in nuclear fragmentation reactions between the impinging ions and the tissue, bearing useful information for confirmation of the delivered treatment during or after therapeutic irradiation. Different implementations of unconventional PET imaging for therapy monitoring are currently being investigated clinically, and major ongoing research aims at new dedicated detector technologies and at challenging applications such as real-time imaging and time-resolved in vivo verification of motion compensated beam delivery. This paper provides an overview of the different areas of application of PET in radiation oncology and discusses the most promising perspectives in the years to come for radiation therapy

  15. Vision 20/20: Positron emission tomography in radiation therapy planning, delivery, and monitoring

    International Nuclear Information System (INIS)

    Parodi, Katia

    2015-01-01

    Positron emission tomography (PET) is increasingly considered as an effective imaging method to support several stages of radiation therapy. The combined usage of functional and morphological imaging in state-of-the-art PET/CT scanners is rapidly emerging to support the treatment planning process in terms of improved tumor delineation, and to assess the tumor response in follow-up investigations after or even during the course of fractionated therapy. Moreover, active research is being pursued on new tracers capable of providing different insights into tumor function, in order to identify areas of the planning volume which may require additional dosage for improved probability of tumor control. In this respect, major progresses in the next years will likely concern the development and clinical investigation of novel tracers and image processing techniques for reliable thresholding and segmentation, of treatment planning and beam delivery approaches integrating the PET imaging information, as well as improved multimodal clinical instrumentation such as PET/MR. But especially in the rapidly emerging case of ion beam therapy, the usage of PET is not only limited to the imaging of external tracers injected to the patient. In fact, a minor amount of positron emitters is formed in nuclear fragmentation reactions between the impinging ions and the tissue, bearing useful information for confirmation of the delivered treatment during or after therapeutic irradiation. Different implementations of unconventional PET imaging for therapy monitoring are currently being investigated clinically, and major ongoing research aims at new dedicated detector technologies and at challenging applications such as real-time imaging and time-resolved in vivo verification of motion compensated beam delivery. This paper provides an overview of the different areas of application of PET in radiation oncology and discusses the most promising perspectives in the years to come for radiation therapy

  16. Gamma-index method sensitivity for gauging plan delivery accuracy of volumetric modulated arc therapy.

    Science.gov (United States)

    Park, Jong In; Park, Jong Min; Kim, Jung-In; Park, So-Yeon; Ye, Sung-Joon

    2015-12-01

    The aim of this study was to investigate the sensitivity of the gamma-index method according to various gamma criteria for volumetric modulated arc therapy (VMAT). Twenty head and neck (HN) and twenty prostate VMAT plans were retrospectively selected for this study. Both global and local 2D gamma evaluations were performed with criteria of 3%/3 mm, 2%/2 mm, 1%/2 mm and 2%/1 mm. In this study, the global and local gamma-index calculated the differences in doses relative to the maximum dose and the dose at the current measurement point, respectively. Using log files acquired during delivery, the differences in parameters at every control point between the VMAT plans and the log files were acquired. The differences in dose-volumetric parameters between reconstructed VMAT plans using the log files and the original VMAT plans were calculated. The Spearman's rank correlation coefficients (rs) were calculated between the passing rates and those differences. Considerable correlations with statistical significances were observed between global 1%/2 mm, local 1%/2 mm and local 2%/1 mm and the MLC position differences (rs = -0.712, -0.628 and -0.581). The numbers of rs values with statistical significance between the passing rates and the changes in dose-volumetric parameters were largest in global 2%/2 mm (n = 16), global 2%/1 mm (n = 15) and local 2%/1 mm (n = 13) criteria. Local gamma-index method with 2%/1 mm generally showed higher sensitivity to detect deviations between a VMAT plan and the delivery of the VMAT plan. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  17. MRI imaging of fetal neck masses with airway compromise: utility in delivery planning

    Energy Technology Data Exchange (ETDEWEB)

    Kathary, N.; Bulas, D.I. [Dept. of Radiology, Children' s National Medical Center, Washington, DC (United States); Newman, K.D. [Dept. of Surgery, Children' s National Medical Center, Washington, DC (United States); Schonberg, R.L. [Dept. of Medical Genetics, Children' s National Medical Center, Washington, DC (United States)

    2001-10-01

    We present two cases of fetal neck masses that were initially diagnosed by ultrasound and further evaluated with prenatal MRI. MRI findings aided in further delineating the neck masses, increasing confidence in the final diagnosis (cervical teratoma and cystic hygroma). With the fetal airway typically filled with fluid that is of high signal on T2-weighted sequences, MRI images in three planes could identify whether the fetal larynx and trachea were partially or completely compressed by the neck tumor. This information was particularly useful in determining if a controlled delivery such as ex utero intrapartum treatment (EXIT) was necessary and aided the surgeons in planning their approach to establishing airway control in the delivery room. (orig.)

  18. MRI imaging of fetal neck masses with airway compromise: utility in delivery planning

    International Nuclear Information System (INIS)

    Kathary, N.; Bulas, D.I.; Newman, K.D.; Schonberg, R.L.

    2001-01-01

    We present two cases of fetal neck masses that were initially diagnosed by ultrasound and further evaluated with prenatal MRI. MRI findings aided in further delineating the neck masses, increasing confidence in the final diagnosis (cervical teratoma and cystic hygroma). With the fetal airway typically filled with fluid that is of high signal on T2-weighted sequences, MRI images in three planes could identify whether the fetal larynx and trachea were partially or completely compressed by the neck tumor. This information was particularly useful in determining if a controlled delivery such as ex utero intrapartum treatment (EXIT) was necessary and aided the surgeons in planning their approach to establishing airway control in the delivery room. (orig.)

  19. Treatment planning, optimization, and beam delivery technqiues for intensity modulated proton therapy

    Science.gov (United States)

    Sengbusch, Evan R.

    Physical properties of proton interactions in matter give them a theoretical advantage over photons in radiation therapy for cancer treatment, but they are seldom used relative to photons. The primary barriers to wider acceptance of proton therapy are the technical feasibility, size, and price of proton therapy systems. Several aspects of the proton therapy landscape are investigated, and new techniques for treatment planning, optimization, and beam delivery are presented. The results of these investigations suggest a means by which proton therapy can be delivered more efficiently, effectively, and to a much larger proportion of eligible patients. An analysis of the existing proton therapy market was performed. Personal interviews with over 30 radiation oncology leaders were conducted with regard to the current and future use of proton therapy. In addition, global proton therapy market projections are presented. The results of these investigations serve as motivation and guidance for the subsequent development of treatment system designs and treatment planning, optimization, and beam delivery methods. A major factor impacting the size and cost of proton treatment systems is the maximum energy of the accelerator. Historically, 250 MeV has been the accepted value, but there is minimal quantitative evidence in the literature that supports this standard. A retrospective study of 100 patients is presented that quantifies the maximum proton kinetic energy requirements for cancer treatment, and the impact of those results with regard to treatment system size, cost, and neutron production is discussed. This study is subsequently expanded to include 100 cranial stereotactic radiosurgery (SRS) patients, and the results are discussed in the context of a proposed dedicated proton SRS treatment system. Finally, novel proton therapy optimization and delivery techniques are presented. Algorithms are developed that optimize treatment plans over beam angle, spot size, spot spacing

  20. TU-A-304-02: Treatment Simulation, Planning and Delivery for SBRT

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.

    2015-06-15

    Increased use of SBRT and hypo fractionation in radiation oncology practice has posted a number of challenges to medical physicist, ranging from planning, image-guided patient setup and on-treatment monitoring, to quality assurance (QA) and dose delivery. This symposium is designed to provide updated knowledge necessary for the safe and efficient implementation of SBRT in various linac platforms, including the emerging digital linacs equipped with high dose rate FFF beams. Issues related to 4D CT, PET and MRI simulations, 3D/4D CBCT guided patient setup, real-time image guidance during SBRT dose delivery using gated/un-gated VMAT or IMRT, and technical advancements in QA of SBRT (in particular, strategies dealing with high dose rate FFF beams) will be addressed. The symposium will help the attendees to gain a comprehensive understanding of the SBRT workflow and facilitate their clinical implementation of the state-of-art imaging and planning techniques. Learning Objectives: Present background knowledge of SBRT, describe essential requirements for safe implementation of SBRT, and discuss issues specific to SBRT treatment planning and QA. Update on the use of multi-dimensional (3D and 4D) and multi-modality (CT, beam-level X-ray imaging, pre- and on-treatment 3D/4D MRI, PET, robotic ultrasound, etc.) for reliable guidance of SBRT. Provide a comprehensive overview of emerging digital linacs and summarize the key geometric and dosimetric features of the new generation of linacs for substantially improved SBRT. Discuss treatment planning and quality assurance issues specific to SBRT. Research grant from Varian Medical Systems.

  1. Bubble and foam chemistry

    CERN Document Server

    Pugh, Robert J

    2016-01-01

    This indispensable guide will equip the reader with a thorough understanding of the field of foaming chemistry. Assuming only basic theoretical background knowledge, the book provides a straightforward introduction to the principles and properties of foams and foaming surfactants. It discusses the key ideas that underpin why foaming occurs, how it can be avoided and how different degrees of antifoaming can be achieved, and covers the latest test methods, including laboratory and industrial developed techniques. Detailing a variety of different kinds of foams, from wet detergents and food foams, to polymeric, material and metal foams, it connects theory to real-world applications and recent developments in foam research. Combining academic and industrial viewpoints, this book is the definitive stand-alone resource for researchers, students and industrialists working on foam technology, colloidal systems in the field of chemical engineering, fluid mechanics, physical chemistry, and applied physics.

  2. The development and verification of a highly accurate collision prediction model for automated noncoplanar plan delivery

    International Nuclear Information System (INIS)

    Yu, Victoria Y.; Tran, Angelia; Nguyen, Dan; Cao, Minsong; Ruan, Dan; Low, Daniel A.; Sheng, Ke

    2015-01-01

    Purpose: Significant dosimetric benefits had been previously demonstrated in highly noncoplanar treatment plans. In this study, the authors developed and verified an individualized collision model for the purpose of delivering highly noncoplanar radiotherapy and tested the feasibility of total delivery automation with Varian TrueBeam developer mode. Methods: A hand-held 3D scanner was used to capture the surfaces of an anthropomorphic phantom and a human subject, which were positioned with a computer-aided design model of a TrueBeam machine to create a detailed virtual geometrical collision model. The collision model included gantry, collimator, and couch motion degrees of freedom. The accuracy of the 3D scanner was validated by scanning a rigid cubical phantom with known dimensions. The collision model was then validated by generating 300 linear accelerator orientations corresponding to 300 gantry-to-couch and gantry-to-phantom distances, and comparing the corresponding distance measurements to their corresponding models. The linear accelerator orientations reflected uniformly sampled noncoplanar beam angles to the head, lung, and prostate. The distance discrepancies between measurements on the physical and virtual systems were used to estimate treatment-site-specific safety buffer distances with 0.1%, 0.01%, and 0.001% probability of collision between the gantry and couch or phantom. Plans containing 20 noncoplanar beams to the brain, lung, and prostate optimized via an in-house noncoplanar radiotherapy platform were converted into XML script for automated delivery and the entire delivery was recorded and timed to demonstrate the feasibility of automated delivery. Results: The 3D scanner measured the dimension of the 14 cm cubic phantom within 0.5 mm. The maximal absolute discrepancy between machine and model measurements for gantry-to-couch and gantry-to-phantom was 0.95 and 2.97 cm, respectively. The reduced accuracy of gantry-to-phantom measurements was

  3. The development and verification of a highly accurate collision prediction model for automated noncoplanar plan delivery

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Victoria Y.; Tran, Angelia; Nguyen, Dan; Cao, Minsong; Ruan, Dan; Low, Daniel A.; Sheng, Ke, E-mail: ksheng@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90024 (United States)

    2015-11-15

    Purpose: Significant dosimetric benefits had been previously demonstrated in highly noncoplanar treatment plans. In this study, the authors developed and verified an individualized collision model for the purpose of delivering highly noncoplanar radiotherapy and tested the feasibility of total delivery automation with Varian TrueBeam developer mode. Methods: A hand-held 3D scanner was used to capture the surfaces of an anthropomorphic phantom and a human subject, which were positioned with a computer-aided design model of a TrueBeam machine to create a detailed virtual geometrical collision model. The collision model included gantry, collimator, and couch motion degrees of freedom. The accuracy of the 3D scanner was validated by scanning a rigid cubical phantom with known dimensions. The collision model was then validated by generating 300 linear accelerator orientations corresponding to 300 gantry-to-couch and gantry-to-phantom distances, and comparing the corresponding distance measurements to their corresponding models. The linear accelerator orientations reflected uniformly sampled noncoplanar beam angles to the head, lung, and prostate. The distance discrepancies between measurements on the physical and virtual systems were used to estimate treatment-site-specific safety buffer distances with 0.1%, 0.01%, and 0.001% probability of collision between the gantry and couch or phantom. Plans containing 20 noncoplanar beams to the brain, lung, and prostate optimized via an in-house noncoplanar radiotherapy platform were converted into XML script for automated delivery and the entire delivery was recorded and timed to demonstrate the feasibility of automated delivery. Results: The 3D scanner measured the dimension of the 14 cm cubic phantom within 0.5 mm. The maximal absolute discrepancy between machine and model measurements for gantry-to-couch and gantry-to-phantom was 0.95 and 2.97 cm, respectively. The reduced accuracy of gantry-to-phantom measurements was

  4. The development and verification of a highly accurate collision prediction model for automated noncoplanar plan delivery.

    Science.gov (United States)

    Yu, Victoria Y; Tran, Angelia; Nguyen, Dan; Cao, Minsong; Ruan, Dan; Low, Daniel A; Sheng, Ke

    2015-11-01

    Significant dosimetric benefits had been previously demonstrated in highly noncoplanar treatment plans. In this study, the authors developed and verified an individualized collision model for the purpose of delivering highly noncoplanar radiotherapy and tested the feasibility of total delivery automation with Varian TrueBeam developer mode. A hand-held 3D scanner was used to capture the surfaces of an anthropomorphic phantom and a human subject, which were positioned with a computer-aided design model of a TrueBeam machine to create a detailed virtual geometrical collision model. The collision model included gantry, collimator, and couch motion degrees of freedom. The accuracy of the 3D scanner was validated by scanning a rigid cubical phantom with known dimensions. The collision model was then validated by generating 300 linear accelerator orientations corresponding to 300 gantry-to-couch and gantry-to-phantom distances, and comparing the corresponding distance measurements to their corresponding models. The linear accelerator orientations reflected uniformly sampled noncoplanar beam angles to the head, lung, and prostate. The distance discrepancies between measurements on the physical and virtual systems were used to estimate treatment-site-specific safety buffer distances with 0.1%, 0.01%, and 0.001% probability of collision between the gantry and couch or phantom. Plans containing 20 noncoplanar beams to the brain, lung, and prostate optimized via an in-house noncoplanar radiotherapy platform were converted into XML script for automated delivery and the entire delivery was recorded and timed to demonstrate the feasibility of automated delivery. The 3D scanner measured the dimension of the 14 cm cubic phantom within 0.5 mm. The maximal absolute discrepancy between machine and model measurements for gantry-to-couch and gantry-to-phantom was 0.95 and 2.97 cm, respectively. The reduced accuracy of gantry-to-phantom measurements was attributed to phantom setup

  5. Foams theory, measurements, and applications

    CERN Document Server

    Khan, Saad A

    1996-01-01

    This volume discusses the physics and physical processes of foam and foaming. It delineates various measurement techniques for characterizing foams and foam properties as well as the chemistry and application of foams. The use of foams in the textile industry, personal care products, enhanced oil recovery, firefighting and mineral floatation are highlighted, and the connection between the microstructure and physical properties of foam are detailed. Coverage includes nonaqueous foams and silicone antifoams, and more.

  6. Two-dimensional inverse planning and delivery with a preclinical image guided microirradiator

    International Nuclear Information System (INIS)

    Stewart, James M. P.; Lindsay, Patricia E.; Jaffray, David A.

    2013-01-01

    profiles taken through the sock distribution of 3.9%. Mean absolute delivery error across the 0–1 Gy linear dose gradient over 7.5 mm was 0.01 Gy.Conclusions: The work presented here demonstrates the potential for complex dose distributions to be planned and automatically delivered with millimeter scale heterogeneity at submillimeter accuracy. This capability establishes the technical foundation for preclinical validation of biologically guided radiotherapy investigations and development of unique radiobiological experiments

  7. Polyurethane-Foam Maskant

    Science.gov (United States)

    Bodemeijer, R.

    1985-01-01

    Brown wax previously used to mask hardware replaced with polyurethane foam in electroplating and electroforming operations. Foam easier to apply and remove than wax and does not contaminate electrolytes.

  8. Fire retardant polyisocyanurate foam

    Science.gov (United States)

    Riccitiello, S. R.; Parker, J. A.

    1972-01-01

    Fire retardant properties of low density polymer foam are increased. Foam has pendant nitrile groups which form thermally-stable heterocyclic structures at temperature below degradation temperature of urethane linkages.

  9. Increased planned delivery contributes to declining rates of pregnancy hypertension in Australia: a population-based record linkage study.

    Science.gov (United States)

    Roberts, Christine L; Algert, Charles S; Morris, Jonathan M; Ford, Jane B

    2015-10-05

    Since the 1990s, pregnancy hypertension rates have declined in some countries, but not all. Increasing rates of early planned delivery (before the due date) have been hypothesised as the reason for the decline. The aim of this study was to explore whether early planned delivery can partly explain the declining pregnancy hypertension rates in Australia. Population-based record linkage study utilising linked birth and hospital records. A cohort of 1,076,122 deliveries in New South Wales, Australia, 2001-2012. Pregnancy hypertension (including gestational hypertension, pre-eclampsia and eclampsia) was the main outcome; pre-eclampsia was a secondary outcome. From 2001 to 2012, pregnancy hypertension rates declined by 22%, from 9.9% to 7.7%, and pre-eclampsia by 27%, from 3.3% to 2.4% (trend prate was predicted to increase to 10.5%. Examination of annual gestational age distributions showed that pregnancy hypertension rates actually declined from 38 weeks gestation and were steepest from 41 weeks; at least 36% of the decrease could be attributed to planned deliveries. The risk factors for pregnancy hypertension were also risk factors for planned delivery. It appears that an unanticipated consequence of increasing early planned deliveries is a decline in the incidence of pregnancy hypertension. Women with risk factors for hypertension were relatively more likely to be selected for early delivery. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  10. Multimodality Image Fusion and Planning and Dose Delivery for Radiation Therapy

    International Nuclear Information System (INIS)

    Saw, Cheng B.; Chen Hungcheng; Beatty, Ron E.; Wagner, Henry

    2008-01-01

    Image-guided radiation therapy (IGRT) relies on the quality of fused images to yield accurate and reproducible patient setup prior to dose delivery. The registration of 2 image datasets can be characterized as hardware-based or software-based image fusion. Hardware-based image fusion is performed by hybrid scanners that combine 2 distinct medical imaging modalities such as positron emission tomography (PET) and computed tomography (CT) into a single device. In hybrid scanners, the patient maintains the same position during both studies making the fusion of image data sets simple. However, it cannot perform temporal image registration where image datasets are acquired at different times. On the other hand, software-based image fusion technique can merge image datasets taken at different times or with different medical imaging modalities. Software-based image fusion can be performed either manually, using landmarks, or automatically. In the automatic image fusion method, the best fit is evaluated using mutual information coefficient. Manual image fusion is typically performed at dose planning and for patient setup prior to dose delivery for IGRT. The fusion of orthogonal live radiographic images taken prior to dose delivery to digitally reconstructed radiographs will be presented. Although manual image fusion has been routinely used, the use of fiducial markers has shortened the fusion time. Automated image fusion should be possible for IGRT because the image datasets are derived basically from the same imaging modality, resulting in further shortening the fusion time. The advantages and limitations of both hardware-based and software-based image fusion methodologies are discussed

  11. Foam engineering fundamentals and applications

    CERN Document Server

    2012-01-01

    Containing contributions from leading academic and industrial researchers, this book provides a much needed update of foam science research. The first section of the book presents an accessible summary of the theory and fundamentals of foams. This includes chapters on morphology, drainage, Ostwald ripening, coalescence, rheology, and pneumatic foams. The second section demonstrates how this theory is used in a wide range of industrial applications, including foam fractionation, froth flotation and foam mitigation. It includes chapters on suprafroths, flotation of oil sands, foams in enhancing petroleum recovery, Gas-liquid Mass Transfer in foam, foams in glass manufacturing, fire-fighting foam technology and consumer product foams.

  12. Methods to model and predict the ViewRay treatment deliveries to aid patient scheduling and treatment planning.

    Science.gov (United States)

    Liu, Shi; Wu, Yu; Wooten, H Omar; Green, Olga; Archer, Brent; Li, Harold; Yang, Deshan

    2016-03-08

    A software tool is developed, given a new treatment plan, to predict treatment delivery time for radiation therapy (RT) treatments of patients on ViewRay magnetic resonance image-guided radiation therapy (MR-IGRT) delivery system. This tool is necessary for managing patient treatment scheduling in our clinic. The predicted treatment delivery time and the assessment of plan complexities could also be useful to aid treatment planning. A patient's total treatment delivery time, not including time required for localization, is modeled as the sum of four components: 1) the treatment initialization time; 2) the total beam-on time; 3) the gantry rotation time; and 4) the multileaf collimator (MLC) motion time. Each of the four components is predicted separately. The total beam-on time can be calculated using both the planned beam-on time and the decay-corrected dose rate. To predict the remain-ing components, we retrospectively analyzed the patient treatment delivery record files. The initialization time is demonstrated to be random since it depends on the final gantry angle of the previous treatment. Based on modeling the relationships between the gantry rotation angles and the corresponding rotation time, linear regression is applied to predict the gantry rotation time. The MLC motion time is calculated using the leaves delay modeling method and the leaf motion speed. A quantitative analysis was performed to understand the correlation between the total treatment time and the plan complexity. The proposed algorithm is able to predict the ViewRay treatment delivery time with the average prediction error 0.22min or 1.82%, and the maximal prediction error 0.89 min or 7.88%. The analysis has shown the correlation between the plan modulation (PM) factor and the total treatment delivery time, as well as the treatment delivery duty cycle. A possibility has been identified to significantly reduce MLC motion time by optimizing the positions of closed MLC pairs. The accuracy of

  13. SU-C-BRD-01: Multi-Centre Collaborative Quality Assurance Program for IMRT Planning and Delivery: Year 3 Results

    International Nuclear Information System (INIS)

    McNiven, A; Jaffray, D; Letourneau, D

    2015-01-01

    Purpose: A multi-centre quality assurance program was developed to enable quality improvement by coupling measurement of intensity modulated radiotherapy (IMRT) planning and delivery performance for site-specific planning exercises with diagnostic testing. The third year of the program specifically assessed the quality of spine stereotactic body radiotherapy (SBRT) planning and delivery amongst the participating centres. Methods: A spine SBRT planning exercise (24 Gy in 2 fractions) was created and completed by participants prior to an on-site visit. The delivery portion of the on-site visit included spine SBRT plan delivery and diagnostic testing, which included portal image acquisition for quantification of phantom positioning error and multi-leaf collimator (MLC) calibration accuracy. The measured dose was compared to that calculated in the treatment planning system (TPS) using 3%/2mm composite analysis and 3%/3mm gamma analysis. Results: Fourteen institutions participated, creating 17 spine SBRT plans (15 VMAT and 2 IMRT). Three different TPS, two beam energies (6 MV and 6 MV FFF), and four MLC designs from two linac vendors were tested. Large variation in total monitor units (MU) per plan (2494–6462 MU) and dose-volume parameters was observed. The maximum point dose in the plans ranged from 116–149% and was dependent upon the TPS used. Pass rates for measured to planned dose comparison ranged from 89.4–100% and 97.3–100% for 3%/2mm and 3%/3mm criteria respectively. The largest measured MLC error did Result in one of the poorer pass rates. No direct correlation between phantom positioning error and pass rates overall. Conclusion: Significant differences were observed in the planning exercise for some plan and dose-volume parameters based on the TPS used. Standard evaluation criteria showed good agreement between planned and measured dose for all participants, however on an individual plan basis, diagnostic tests were able to identify contributing

  14. SU-C-BRD-01: Multi-Centre Collaborative Quality Assurance Program for IMRT Planning and Delivery: Year 3 Results

    Energy Technology Data Exchange (ETDEWEB)

    McNiven, A; Jaffray, D; Letourneau, D [Princess Margaret Cancer Centre and Department of Radiation Oncology, University of Toronto, Toronto, ON (Canada)

    2015-06-15

    Purpose: A multi-centre quality assurance program was developed to enable quality improvement by coupling measurement of intensity modulated radiotherapy (IMRT) planning and delivery performance for site-specific planning exercises with diagnostic testing. The third year of the program specifically assessed the quality of spine stereotactic body radiotherapy (SBRT) planning and delivery amongst the participating centres. Methods: A spine SBRT planning exercise (24 Gy in 2 fractions) was created and completed by participants prior to an on-site visit. The delivery portion of the on-site visit included spine SBRT plan delivery and diagnostic testing, which included portal image acquisition for quantification of phantom positioning error and multi-leaf collimator (MLC) calibration accuracy. The measured dose was compared to that calculated in the treatment planning system (TPS) using 3%/2mm composite analysis and 3%/3mm gamma analysis. Results: Fourteen institutions participated, creating 17 spine SBRT plans (15 VMAT and 2 IMRT). Three different TPS, two beam energies (6 MV and 6 MV FFF), and four MLC designs from two linac vendors were tested. Large variation in total monitor units (MU) per plan (2494–6462 MU) and dose-volume parameters was observed. The maximum point dose in the plans ranged from 116–149% and was dependent upon the TPS used. Pass rates for measured to planned dose comparison ranged from 89.4–100% and 97.3–100% for 3%/2mm and 3%/3mm criteria respectively. The largest measured MLC error did Result in one of the poorer pass rates. No direct correlation between phantom positioning error and pass rates overall. Conclusion: Significant differences were observed in the planning exercise for some plan and dose-volume parameters based on the TPS used. Standard evaluation criteria showed good agreement between planned and measured dose for all participants, however on an individual plan basis, diagnostic tests were able to identify contributing

  15. Preventing Elder Abuse: The Texas Plan for a Coordinated Service Delivery System. Collaborative Elder Abuse Prevention Project.

    Science.gov (United States)

    McDaniel, Garry L.

    The Texas Department of Human Services, in collaboration with 13 other public and private organizations, co-sponsored a statewide Collaborative Elder Abuse Prevention project. The goal of this project is to develop a comprehensive, long-range plan for the prevention of elder abuse, a method for achieving a coordinated service delivery system for…

  16. Operator spin foam models

    International Nuclear Information System (INIS)

    Bahr, Benjamin; Hellmann, Frank; Kaminski, Wojciech; Kisielowski, Marcin; Lewandowski, Jerzy

    2011-01-01

    The goal of this paper is to introduce a systematic approach to spin foams. We define operator spin foams, that is foams labelled by group representations and operators, as our main tool. A set of moves we define in the set of the operator spin foams (among other operations) allows us to split the faces and the edges of the foams. We assign to each operator spin foam a contracted operator, by using the contractions at the vertices and suitably adjusted face amplitudes. The emergence of the face amplitudes is the consequence of assuming the invariance of the contracted operator with respect to the moves. Next, we define spin foam models and consider the class of models assumed to be symmetric with respect to the moves we have introduced, and assuming their partition functions (state sums) are defined by the contracted operators. Briefly speaking, those operator spin foam models are invariant with respect to the cellular decomposition, and are sensitive only to the topology and colouring of the foam. Imposing an extra symmetry leads to a family we call natural operator spin foam models. This symmetry, combined with assumed invariance with respect to the edge splitting move, determines a complete characterization of a general natural model. It can be obtained by applying arbitrary (quantum) constraints on an arbitrary BF spin foam model. In particular, imposing suitable constraints on a spin(4) BF spin foam model is exactly the way we tend to view 4D quantum gravity, starting with the BC model and continuing with the Engle-Pereira-Rovelli-Livine (EPRL) or Freidel-Krasnov (FK) models. That makes our framework directly applicable to those models. Specifically, our operator spin foam framework can be translated into the language of spin foams and partition functions. Among our natural spin foam models there are the BF spin foam model, the BC model, and a model corresponding to the EPRL intertwiners. Our operator spin foam framework can also be used for more general spin

  17. Anaerobic Digestion Foaming Causes

    OpenAIRE

    Ganidi, Nafsika

    2008-01-01

    Anaerobic digestion foaming has been encountered in several sewage treatment plants in the UK. Foaming has raised major concerns for the water utilities due to significant impacts on process efficiency and operational costs. Several foaming causes have been suggested over the past few years by researchers. However, the supporting experimental information is limited and in some cases site specific. The present report aimed to provide a better understanding of the anaerobic di...

  18. Thermosetting Fluoropolymer Foams

    Science.gov (United States)

    Lee, Sheng Yen

    1987-01-01

    New process makes fluoropolymer foams with controllable amounts of inert-gas fillings in foam cells. Thermosetting fluoropolymers do not require foaming additives leaving undesirable residues and do not have to be molded and sintered at temperatures of about 240 to 400 degree C. Consequently, better for use with electronic or other parts sensitive to high temperatures or residues. Uses include coatings, electrical insulation, and structural parts.

  19. High performance polymeric foams

    International Nuclear Information System (INIS)

    Gargiulo, M.; Sorrentino, L.; Iannace, S.

    2008-01-01

    The aim of this work was to investigate the foamability of high-performance polymers (polyethersulfone, polyphenylsulfone, polyetherimide and polyethylenenaphtalate). Two different methods have been used to prepare the foam samples: high temperature expansion and two-stage batch process. The effects of processing parameters (saturation time and pressure, foaming temperature) on the densities and microcellular structures of these foams were analyzed by using scanning electron microscopy

  20. Fire-retardant foams

    Science.gov (United States)

    Gagliani, J.

    1978-01-01

    Family of polyimide resins are being developed as foams with exceptional fire-retardant properties. Foams are potentially useful for seat cushions in aircraft and ground vehicles and for applications such as home furnishings and building-construction materials. Basic formulations can be modified with reinforcing fibers or fillers to produce celular materials for variety of applications. By selecting reactants, polymer structure can be modified to give foams with properties ranging from high resiliency and flexibility to brittleness and rigidity.

  1. The dosimetric impact of inversely optimized arc radiotherapy plan modulation for real-time dynamic MLC tracking delivery

    International Nuclear Information System (INIS)

    Falk, Marianne; Larsson, Tobias; Keall, Paul; Chul Cho, Byung; Aznar, Marianne; Korreman, Stine; Poulsen, Per; Munck af Rosenschoeld, Per

    2012-01-01

    Purpose: Real-time dynamic multileaf collimator (MLC) tracking for management of intrafraction tumor motion can be challenging for highly modulated beams, as the leaves need to travel far to adjust for target motion perpendicular to the leaf travel direction. The plan modulation can be reduced by using a leaf position constraint (LPC) that reduces the difference in the position of adjacent MLC leaves in the plan. The purpose of this study was to investigate the impact of the LPC on the quality of inversely optimized arc radiotherapy plans and the effect of the MLC motion pattern on the dosimetric accuracy of MLC tracking delivery. Specifically, the possibility of predicting the accuracy of MLC tracking delivery based on the plan modulation was investigated. Methods: Inversely optimized arc radiotherapy plans were created on CT-data of three lung cancer patients. For each case, five plans with a single 358 deg. arc were generated with LPC priorities of 0 (no LPC), 0.25, 0.5, 0.75, and 1 (highest possible LPC), respectively. All the plans had a prescribed dose of 2 Gy x 30, used 6 MV, a maximum dose rate of 600 MU/min and a collimator angle of 45 deg. or 315 deg. To quantify the plan modulation, an average adjacent leaf distance (ALD) was calculated by averaging the mean adjacent leaf distance for each control point. The linear relationship between the plan quality [i.e., the calculated dose distributions and the number of monitor units (MU)] and the LPC was investigated, and the linear regression coefficient as well as a two tailed confidence level of 95% was used in the evaluation. The effect of the plan modulation on the performance of MLC tracking was tested by delivering the plans to a cylindrical diode array phantom moving with sinusoidal motion in the superior-inferior direction with a peak-to-peak displacement of 2 cm and a cycle time of 6 s. The delivery was adjusted to the target motion using MLC tracking, guided in real-time by an infrared optical system

  2. Flexible Foam Model.

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, Michael K.; Lu, Wei-Yang; Werner, Brian T.; Scherzinger, William M.; Lo, Chi S.

    2018-03-01

    Experiments were performed to characterize the mechanical response of a 15 pcf flexible polyurethane foam to large deformation at different strain rates and temperatures. Results from these experiments indicated that at room temperature, flexible polyurethane foams exhibit significant nonlinear elastic deformation and nearly return to their original undeformed shape when unloaded. However, when these foams are cooled to temperatures below their glass transition temperature of approximately -35 o C, they behave like rigid polyurethane foams and exhibit significant permanent deformation when compressed. Thus, a new model which captures this dramatic change in behavior with temperature was developed and implemented into SIERRA with the name Flex_Foam to describe the mechanical response of both flexible and rigid foams to large deformation at a variety of temperatures and strain rates. This report includes a description of recent experiments. Next, development of the Flex Foam model for flexible polyurethane and other flexible foams is described. Selection of material parameters are discussed and finite element simulations with the new Flex Foam model are compared with experimental results to show behavior that can be captured with this new model.

  3. SU-E-T-127: Application of TG-119 for Evaluation of Proton Spot Scanning Based Planning and Treatment Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Saini, J; Cao, N; Wong, T [SCCA Proton Therapy, A Procure Center, Seattle, WA (United States); Bowen, S; Bloch, C [University of Washington, School of Medicine, Seattle, WA (United States)

    2015-06-15

    Purpose: The clinical test cases presented in AAPM TG-119 are used to evaluate the accuracy of treatment planning and delivery through spot scanning proton beams. Methods: An IBA spot scanning delivery system has been commissioned to be used with the RayStation treatment planning system. Various test cases provided in TG-119 were used for planning and delivery verification. The CT dataset and structures as provided by TG-119 were imported into a mock patient. The plans were optimized using the multi field optimization (MFO) to achieve the desired goals. The planner was given the flexibility to achieve the given dose-volume goals by creating appropriate objectives and constraints. Beams were delivered to a phantom and measurements were performed at multiple depths using the MatrixxPT detector array. The analyses were performed on beam by beam basis and quantified using the gamma index. A tolerance of 3%/3 mm in 2D was used for gamma index analysis along with dose threshold of 10%. Results: The clinical goals for targets and critical structures were met or improved for all cases except the C-Shape target with difficult constraints. The minimum gamma index using the 3%/3mm as a criterion is 93.3% for one of the planes measured for C-Shape target. Using 2%/2mm as a criterion, the minimum gamma index drops to 70%. Only Prostate target has all the planes above >90% pass using the 2%/2mm criterion. Conclusion: The overall accuracy of the treatment planning and delivery is deemed clinically acceptable. The test cases with highly modulated beams can have steep gradients in the dose profiles that can reduce the gamma index pass rate. Gamma analysis based on 3D data may be needed for routine use of 2%/2mm criterion. In addition, improvements in modelling of spot profiles in dose engine may be required for further improving the gamma index pass rate.

  4. Improving family planning services delivery and uptake: experiences from the "Reversing the Stall in Fertility Decline in Western Kenya Project".

    Science.gov (United States)

    Amo-Adjei, Joshua; Mutua, Michael; Athero, Sherine; Izugbara, Chimaraoke; Ezeh, Alex

    2017-10-10

    In this paper, we reflect on our experiences of implementing a multipronged intervention to improve sexual and reproductive health outcomes. The project used family planning as its entry point and was implemented in two high fertility counties-Busia and Siaya in Kenya. The intervention, implemented by a seven-member consortium, involved: family planning services delivery; regular training of service providers to deliver high quality services; monitoring and evaluation; strengthening of commodity chain delivery and forecasting; school-based and out-of-school based sexuality education; and advocacy and stakeholder engagements at the community, county and national levels. Over a 5-year period, the project contributed to raising demand for family planning considerably, evidenced in fertility decline. It also improved the capacity of family planning services providers, increased commitment and awareness of county government and other community stakeholders on the importance of investments in family planning. Our collaborations with organisations interested in sexual and reproductive health issues substantially enhanced the consortium's ability to increase demand for, and supply of family planning commodities. These collaborations are proving useful in the continuity and sustainability of project achievements.

  5. NASA Engineering and Safety Center (NESC) Enhanced Melamine (ML) Foam Acoustic Test (NEMFAT)

    Science.gov (United States)

    McNelis, Anne M.; Hughes, William O.; McNelis, Mark E.

    2014-01-01

    The NASA Engineering and Safety Center (NESC) funded a proposal to achieve initial basic acoustic characterization of ML (melamine) foam, which could serve as a starting point for a future, more comprehensive acoustic test program for ML foam. A project plan was developed and implemented to obtain acoustic test data for both normal and enhanced ML foam. This project became known as the NESC Enhanced Melamine Foam Acoustic Test (NEMFAT). This document contains the outcome of the NEMFAT project.

  6. Planning, delivery, and quality assurance of treatment with dynamic multileaf collimator for prostate: a strategy for large scale implementation

    International Nuclear Information System (INIS)

    Burman, Chandra; Chen, Chui; Kutcher, Gerald; Leibel, Steven; Zelefsky, Michael; LoSasso, Thomas; Spirou, Spiridon; Wu Qiuwen; Stein, Jorge; Mohan, Radhe; Ling, C. Clifton; Fuks, Zvi

    1996-01-01

    Purpose: In an attempt to improve tumor control of patients treated for the adenocarcinoma of the prostate, we have implemented a technique to deliver a prescribed dose of 81 Gy. At such high doses, the surrounding normal organs such as the rectum, bladder, and femur impose challenging constraints. We present a method to plan and deliver intensity modulated fields with dynamic multileaf collimators (DMLCs) in an effort to meet the difficult constraints. While the planning technique which uses inverse planning has been described in the literature, safe delivery with DMLC is a new and challenging problem. We will describe in detail our procedures with the emphasis on the delivery problems and chosen solutions. Procedures for the quality assurance of DMLC will be described. Methods and Materials: Using a recently developed and modified inverse planning algorithm, we have developed a 5-field intensity modulated plan that is delivered using DMLC. The planner specifies the target, normal organs, and the desired doses for these tissues and for the overlap regions. The planning system designs the desired intensity profiles to meet the specified criteria. To deliver the dose DMLCs provide a practical and convenient method. A procedure has been developed for the dose delivery. A scheme has been designed to determine the leaf motion to produce the required intensity pattern based on the prescribed dose and the dose rate. In order to ensure that the dose is delivered as planned, we have instituted the following procedures: (1) verification of the aperture shape on a localization port film, (2) an additional dose calculation, which uses the delivered leaf motion, and compares the difference between the planned and delivered doses, (3) comparison of the machine log files, generated during the actual dose delivery, with the planned leaf motions, (4) comparison of the measured dose profile in a flat phantom with the calculated dose distribution using the prescribed treatment

  7. Shortening Delivery Times of Intensity Modulated Proton Therapy by Reducing Proton Energy Layers During Treatment Plan Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Water, Steven van de, E-mail: s.vandewater@erasmusmc.nl [Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands); Kooy, Hanne M. [F. H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Heijmen, Ben J.M.; Hoogeman, Mischa S. [Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands)

    2015-06-01

    Purpose: To shorten delivery times of intensity modulated proton therapy by reducing the number of energy layers in the treatment plan. Methods and Materials: We have developed an energy layer reduction method, which was implemented into our in-house-developed multicriteria treatment planning system “Erasmus-iCycle.” The method consisted of 2 components: (1) minimizing the logarithm of the total spot weight per energy layer; and (2) iteratively excluding low-weighted energy layers. The method was benchmarked by comparing a robust “time-efficient plan” (with energy layer reduction) with a robust “standard clinical plan” (without energy layer reduction) for 5 oropharyngeal cases and 5 prostate cases. Both plans of each patient had equal robust plan quality, because the worst-case dose parameters of the standard clinical plan were used as dose constraints for the time-efficient plan. Worst-case robust optimization was performed, accounting for setup errors of 3 mm and range errors of 3% + 1 mm. We evaluated the number of energy layers and the expected delivery time per fraction, assuming 30 seconds per beam direction, 10 ms per spot, and 400 Giga-protons per minute. The energy switching time was varied from 0.1 to 5 seconds. Results: The number of energy layers was on average reduced by 45% (range, 30%-56%) for the oropharyngeal cases and by 28% (range, 25%-32%) for the prostate cases. When assuming 1, 2, or 5 seconds energy switching time, the average delivery time was shortened from 3.9 to 3.0 minutes (25%), 6.0 to 4.2 minutes (32%), or 12.3 to 7.7 minutes (38%) for the oropharyngeal cases, and from 3.4 to 2.9 minutes (16%), 5.2 to 4.2 minutes (20%), or 10.6 to 8.0 minutes (24%) for the prostate cases. Conclusions: Delivery times of intensity modulated proton therapy can be reduced substantially without compromising robust plan quality. Shorter delivery times are likely to reduce treatment uncertainties and costs.

  8. SU-E-T-370: Evaluating Plan Quality and Dose Delivery Accuracy of Tomotherapy SBRT Treatments for Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Blake, S; Thwaites, D [University of Sydney, Sydney, NSW (Australia); Hansen, C [Odense University Hospital, Odense C (Denmark); Deshpande, S; Phan, P; Franji, I [Liverpool & Macarthur Cancer Therapy Centres, Liverpool, NSW (United Kingdom); Holloway, L [Ingham Institute, Sydney, NSW (Australia)

    2015-06-15

    Purpose: This study evaluated the plan quality and dose delivery accuracy of stereotactic body radiotherapy (SBRT) helical Tomotherapy (HT) treatments for lung cancer. Results were compared with those previously reported by our group for flattening filter (FF) and flattening filter free (FFF) VMAT treatments. This work forms part of an ongoing multicentre and multisystem planning and dosimetry audit on FFF beams for lung SBRT. Methods: CT datasets and DICOM RT structures delineating the target volume and organs at risk for 6 lung cancer patients were selected. Treatment plans were generated using the HT treatment planning system. Tumour locations were classified as near rib, near bronchial tree or in free lung with prescribed doses of 48Gy/4fr, 50Gy/5fr and 54Gy/3fr respectively. Dose constraints were specified by a modified RTOG0915 protocol used for an Australian SBRT phase II trial. Plan quality was evaluated using mean PTV dose, PTV volume receiving 100% of the prescribed dose (V100%), target conformity (CI=VD100%/VPTV) and low dose spillage (LDS=VD50%/VPTV). Planned dose distributions were compared to those measured using an ArcCheck phantom. Delivery accuracy was evaluated using a gamma-index pass rate of 95% with 3% (of max dose) and 3mm criteria. Results: Treatment plans for all patients were clinically acceptable in terms of quality and accuracy of dose delivery. The following DVH metrics are reported as averages (SD) of all plans investigated: mean PTV dose was 115.3(2.4)% of prescription, V100% was 98.8(0.9)%, CI was 1.14(0.03) and LDS was 5.02(0.37). The plans had an average gamma-index passing rate of 99.3(1.3)%. Conclusion: The results reported in this study for HT agree within 1 SD to those previously published by our group for VMAT FF and FFF lung SBRT treatments. This suggests that HT delivers lung SBRT treatments of comparable quality and delivery accuracy as VMAT using both FF and FFF beams.

  9. Volumetric Modulated Arc Therapy for Spine Radiosurgery: Superior Treatment Planning and Delivery Compared to Static Beam Intensity Modulated Radiotherapy.

    Science.gov (United States)

    Zach, Leor; Tsvang, Lev; Alezra, Dror; Ben Ayun, Maoz; Harel, Ran

    2016-01-01

    Spine stereotactic radiosurgery (SRS) delivers an accurate and efficient high radiation dose to vertebral metastases in 1-5 fractions. We aimed to compare volumetric modulated arc therapy (VMAT) to static beam intensity modulated radiotherapy (IMRT) for spine SRS. Ten spine lesions of previously treated SRS patients were planned retrospectively using both IMRT and VMAT with a prescribed dose of 16 Gy to 100% of the planning target volume (PTV). The plans were compared for conformity, homogeneity, treatment delivery time, and safety (spinal cord dose). All evaluated parameters favored the VMAT plan over the IMRT plans. D min in the IMRT was significantly lower than in the VMAT plan (7.65 Gy/10.88 Gy, p DSC) was found to be significantly better for the VMAT plans compared to the IMRT plans (0.77/0.58, resp., p  value < 0.01), and an almost 50% reduction in the net treatment time was calculated for the VMAT compared to the IMRT plans (6.73 min/12.96 min, p < 0.001). In our report, VMAT provides better conformity, homogeneity, and safety profile. The shorter treatment time is a major advantage and not only provides convenience to the painful patient but also contributes to the precision of this high dose radiation therapy.

  10. Volumetric Modulated Arc Therapy for Spine Radiosurgery: Superior Treatment Planning and Delivery Compared to Static Beam Intensity Modulated Radiotherapy

    Directory of Open Access Journals (Sweden)

    Leor Zach

    2016-01-01

    Full Text Available Purpose. Spine stereotactic radiosurgery (SRS delivers an accurate and efficient high radiation dose to vertebral metastases in 1–5 fractions. We aimed to compare volumetric modulated arc therapy (VMAT to static beam intensity modulated radiotherapy (IMRT for spine SRS. Methods and Materials. Ten spine lesions of previously treated SRS patients were planned retrospectively using both IMRT and VMAT with a prescribed dose of 16 Gy to 100% of the planning target volume (PTV. The plans were compared for conformity, homogeneity, treatment delivery time, and safety (spinal cord dose. Results. All evaluated parameters favored the VMAT plan over the IMRT plans. Dmin in the IMRT was significantly lower than in the VMAT plan (7.65 Gy/10.88 Gy, p<0.001, the Dice Similarity Coefficient (DSC was found to be significantly better for the VMAT plans compared to the IMRT plans (0.77/0.58, resp., p  value<0.01, and an almost 50% reduction in the net treatment time was calculated for the VMAT compared to the IMRT plans (6.73 min/12.96 min, p<0.001. Conclusions. In our report, VMAT provides better conformity, homogeneity, and safety profile. The shorter treatment time is a major advantage and not only provides convenience to the painful patient but also contributes to the precision of this high dose radiation therapy.

  11. Stability of minoxidil in Espumil foam base.

    Science.gov (United States)

    Geiger, Christine M; Sorenson, Bridget; Whaley, Paul A

    2013-01-01

    Minoxidil is a drug used to stimulate hair growth and to slow balding. It is marketed under a number of trade names, including Rogaine, and is available in varying strength dose forms from a number of generic manufacturers. Minoxidil is available in oral and topical forms. In topical form, it can be applied by a metered-spray or rub-on applicator. A hydroalcoholic compounding vehicle can minimize greasiness, itching, burning, and contact dermatitis where low concentrations of ethanol and propylene glycol are present. Espumil Foam Base contains low concentrations of these ingredients and also can form a foam on topical application. Espumil's unique delivery by foam-activating packaging assures simple application to difficult-to-treat areas, and it vanishes quickly after application, keeping it in place and avoiding health skin areas. The objective of this study was to determine the stability of minoxidil in Espumil Foam Base. The studied sample was compounded into a 50-mg/mL solution and stored in a plastic foam-activating bottle at room temperature conditions. Three samples were assayed at each time point out to 90 days by a stability-indicating high-performance liquid chromatography method. The method was validated for its specificity through forced-degradation studies. The beyond-use-date is at least 90 days, based on data collected when this formulation was stored at room temperature, protected from light.

  12. Integration of on-line imaging, plan adaptation and radiation delivery: proof of concept using digital tomosynthesis

    International Nuclear Information System (INIS)

    Mestrovic, Ante; Otto, Karl; Nichol, Alan; Clark, Brenda G

    2009-01-01

    The main objective of this manuscript is to propose a new approach to on-line adaptive radiation therapy (ART) in which daily image acquisition, plan adaptation and radiation delivery are integrated together and performed concurrently. A method is described in which on-line ART is performed based on intra-fractional digital tomosynthesis (DTS) images. Intra-fractional DTS images were reconstructed as the gantry rotated between treatment positions. An edge detection algorithm was used to automatically segment the DTS images as the gantry arrived at each treatment position. At each treatment position, radiation was delivered based on the treatment plan re-optimized for the most recent DTS image contours. To investigate the feasibility of this method, a model representing a typical prostate, bladder and rectum was used. To simulate prostate deformations, three clinically relevant, non-rigid deformations (small, medium and large) were modeled by systematically deforming the original anatomy. Using our approach to on-line ART, the original treatment plan was successfully adapted to arrive at a clinically acceptable plan for all three non-rigid deformations. In conclusion, we have proposed a new approach to on-line ART in which plan adaptation is performed based on intra-fractional DTS images. The study findings indicate that this approach can be used to re-optimize the original treatment plan to account for non-rigid anatomical deformations. The advantages of this approach are 1) image acquisition and radiation delivery are integrated in a single gantry rotation around the patient, reducing the treatment time, and 2) intra-fractional DTS images can be used to detect and correct for patient motion prior to the delivery of each beam (intra-fractional patient motion).

  13. Foam Glass for Construction Materials

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund

    2016-01-01

    Foaming is commonly achieved by adding foaming agents such as metal oxides or metal carbonates to glass powder. At elevated temperature, the glass melt becomes viscous and the foaming agents decompose or react to form gas, causing a foamy glass melt. Subsequent cooling to room temperature, result...... in a solid foam glass. The foam glass industry employs a range of different melt precursors and foaming agents. Recycle glass is key melt precursors. Many parameters influence the foaming process and optimising the foaming conditions is very time consuming. The most challenging and attractive goal is to make...... low density foam glass for thermal insulation applications. In this thesis, it is argued that the use of metal carbonates as foaming agents is not suitable for low density foam glass. A reaction mechanism is proposed to justify this result. Furthermore, an in situ method is developed to optimise...

  14. Beer foam physics

    NARCIS (Netherlands)

    Ronteltap, A.D.

    1989-01-01

    The physical aspects of beer foam behavior were studied in terms of the four physical processes, mainly involved in the formation and breakdown of foam. These processes are, bubble formation, drainage, disproportionation and coalescence. In detail, the processes disproportionation and

  15. The dosimetric impact of inversely optimized arc radiotherapy plan modulation for real-time dynamic MLC tracking delivery

    DEFF Research Database (Denmark)

    Falk, Marianne; Larsson, Tobias; Keall, P.

    2012-01-01

    Purpose: Real-time dynamic multileaf collimator (MLC) tracking for management of intrafraction tumor motion can be challenging for highly modulated beams, as the leaves need to travel far to adjust for target motion perpendicular to the leaf travel direction. The plan modulation can be reduced......-to-peak displacement of 2 cm and a cycle time of 6 s. The delivery was adjusted to the target motion using MLC tracking, guided in real-time by an infrared optical system. The dosimetric results were evaluated using gamma index evaluation with static target measurements as reference. Results: The plan quality...

  16. Foam Assisted WAG, Snorre Revisit with New Foam Screening Model

    DEFF Research Database (Denmark)

    Spirov, Pavel; Rudyk, Svetlana Nikolayevna; Khan, Arif

    2012-01-01

    This study deals with simulation model of Foam Assisted Water Alternating Gas (FAWAG) method that had been implemented to two Norwegian Reservoirs. Being studied on number of pilot projects, the method proved successful, but Field Scale simulation was never understood properly. New phenomenological...... of the simulation contributes to more precise planning of the schedule of water and gas injection, prediction of the injection results and evaluation of the method efficiency. The testing of the surfactant properties allows making grounded choice of surfactant to use. The analysis of the history match gives insight...

  17. Family planning providers' perspectives on family planning service delivery in Ibadan and Kaduna, Nigeria: a qualitative study.

    Science.gov (United States)

    Hebert, Luciana Estelle; Schwandt, Hilary Megan; Boulay, Marc; Skinner, Joanna

    2013-01-01

    In Nigeria, fertility continues to be high and contraceptive prevalence remains low. This study was conducted in order to understand the perceptions of, experiences with and challenges of delivering family planning services in two urban areas of Nigeria from the perspectives of family planning service providers. A qualitative study using 59 in-depth interviews was conducted among family planning providers working in hospitals, primary health centres, clinics, pharmacies and patent medicine vendors in Ibadan and Kaduna, Nigeria. Providers support a mix of individuals and organisations involved in family planning provision, including the government of Nigeria. The Nigerian government's role can take a variety of forms, including providing promotional materials for family planning facilities as well as facilitating training and educational opportunities for providers, since many providers lack basic training in family planning provision. Providers often describe their motivation to provide in terms of the health benefits offered by family planning methods. Few providers engage in any marketing of their services and many providers exclude youth and unmarried individuals from their services. The family planning provider community supports a diverse network of providers, but needs further training and support in order to improve the quality of care and market their services. Adolescents, unmarried individuals and women seeking post-abortion care are vulnerable populations that providers need to be better educated about and trained in how to serve. The perspectives of providers should be considered when designing family planning interventions in urban areas of Nigeria.

  18. Impact of foamed matrix components on foamed concrete properties

    Science.gov (United States)

    Tarasenko, V. N.

    2018-03-01

    The improvement of the matrix foam structure by means of foam stabilizing additives is aimed at solving the technology-oriented problems as well as at the further improvement of physical and mechanical properties of cellular-concrete composites. The dry foam mineralization is the mainstream of this research. Adding the concrete densifiers, foam stabilizers and mineral powders reduces the drying shrinkage, which makes the foam concrete products technologically effective.

  19. Technological parameters influence on the non-autoclaved foam concrete characteristics

    Science.gov (United States)

    Bartenjeva, Ekaterina; Mashkin, Nikolay

    2017-01-01

    Foam concretes are used as effective heat-insulating materials. The porous structure of foam concrete provides good insulating and strength properties that make them possible to be used as heat-insulating structural materials. Optimal structure of non-autoclaved foam concrete depends on both technological factors and properties of technical foam. In this connection, the possibility to manufacture heat-insulation structural foam concrete on a high-speed cavity plant with the usage of protein and synthetic foamers was estimated. This experiment was carried out using mathematical planning method, and in this case mathematical models were developed that demonstrated the dependence of operating performance of foam concrete on foaming and rotation speed of laboratory plant. The following material properties were selected for the investigation: average density, compressive strength, bending strength and thermal conductivity. The influence of laboratory equipment technological parameters on technical foam strength and foam stability coefficient in the cement paste was investigated, physical and mechanical properties of non-autoclaved foam concrete were defined based on investigated foam. As a result of investigation, foam concrete samples were developed with performance parameters ensuring their use in production. The mathematical data gathered demonstrated the dependence of foam concrete performance on the technological regime.

  20. Countywide Evaluation of the Long-Term Family Self-Sufficiency Plan. Assessing the Utility of the LTFSS Plan Service Delivery and Planning Framework

    National Research Council Canada - National Science Library

    Davis, Lois

    2002-01-01

    ...) is the lead agency responsible for implementing the evaluation of the LTFSS Plan. On December 5, 2000, the Board approved the implementation plan for the evaluation of the LTFSS Plan, LTFSS Project #46...

  1. Technology of foamed propellants

    Energy Technology Data Exchange (ETDEWEB)

    Boehnlein-Mauss, Jutta; Kroeber, Hartmut [Fraunhofer Institut fuer Chemische Technologie ICT, Pfinztal (Germany)

    2009-06-15

    Foamed propellants are based on crystalline explosives bonded in energetic reaction polymers. Due to their porous structures they are distinguished by high burning rates. Energy content and material characteristics can be varied by using different energetic fillers, energetic polymers and porous structures. Foamed charges can be produced easily by the reaction injection moulding process. For the manufacturing of foamed propellants a semi-continuous remote controlled production plant in pilot scale was set up and a modified reaction injection moulding process was applied. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  2. SU-E-T-325: The New Evaluation Method of the VMAT Plan Delivery Using Varian DynaLog Files and Modulation Complexity Score (MCS)

    Energy Technology Data Exchange (ETDEWEB)

    Tateoka, K [Proton Treatment Center, Radiation Therapy Research Institute, Social Medical Corporation Teishinkai, Sapporo (Japan); Graduate School of Medicine, Sapporo Medical University, Sapporo, JP (Japan); Fujimomo, K; Hareyama, M [Proton Treatment Center, Radiation Therapy Research Institute, Social Medical Corporation Teishinkai, Sapporo (Japan); Saitou, Y; Nakazawa, T; Abe, T; Nakata, A; Yano, M [Graduate School of Medicine, Sapporo Medical University, Sapporo, JP (Japan)

    2014-06-01

    Purpose: The aim of the study is to evaluate the use of Varian DynaLog files to verify VMAT plans delivery and modulation complexity score (MCS) of VMAT. Methods: Delivery accuracy of machine performance was quantified by multileaf collimator (MLC) position errors, gantry angle errors and fluence delivery accuracy for volumetric modulated arc therapy (VMAT). The relationship between machine performance and plan complexity were also investigated using the modulation complexity score (MCS). Plan and Actual MLC positions, gantry angles and delivered fraction of monitor units were extracted from Varian DynaLog files. These factors were taken from the record and verify system of MLC control file. Planned and delivered beam data were compared to determine leaf position errors and gantry angle errors. Analysis was also performed on planned and actual fluence maps reconstructed from those of the DynaLog files. This analysis was performed for all treatment fractions of 5 prostate VMAT plans. The analysis of DynaLog files have been carried out by in-house programming in Visual C++. Results: The root mean square of leaf position and gantry angle errors were about 0.12 and 0.15, respectively. The Gamma of planned and actual fluence maps at 3%/3 mm criterion was about 99.21. The gamma of the leaf position errors were not directly related to plan complexity as determined by the MCS. Therefore, the gamma of the gantry angle errors were directly related to plan complexity as determined by the MCS. Conclusion: This study shows Varian dynalog files for VMAT plan can be diagnosed delivery errors not possible with phantom based quality assurance. Furthermore, the MCS of VMAT plan can evaluate delivery accuracy for patients receiving of VMAT. Machine performance was found to be directly related to plan complexity but this is not the dominant determinant of delivery accuracy.

  3. Perceptions of clients regarding family planning service delivery in a clinic of the Greater Johannesburg Metropolitan Council

    Directory of Open Access Journals (Sweden)

    A. Kellner

    2010-09-01

    Full Text Available Unwanted pregnancies with their negative impact on both women and children occur on an ongoing basis in Gauteng, South Africa. One way to prevent unwanted pregnancies is to use a reliable contraceptive method available free of charge from primary health care clinics providing family planning services throughout Gauteng Province. A literature review was completed on women and access to family planning services and an interview schedule (questionnaire was developed. The purpose of this study was to describe guidelines to meet the expectations of clients accessing family planning services provided by a clinic in Region F, Area 28 of the Greater Johannesburg metropolitan council. This quantitative, exploratory, descriptive and comparative study measured the gaps between the expectations of participants on service delivery and the extent to which these expectations were met. A convenience sample was conducted and consisted of 50 women of reproductive age (ages 15 to 49 attending the family planning clinic. Pre-testing of the instrument was conducted. Structured interviews with a interview schedule were conducted before and after women attended a family planning service. Inferential statistics indicated that there was a significant gap between the client expectations of family planning service delivery and the extent to which these expectations were met. Of the sixty-four items where women indicated the extent of their expectations the findings on only three items were not statistically significant. These gaps were addressed by proposing managerial guidelines to be implemented by the nurse manager in charge of the facility, on which this article will focus. Validity and reliability principles were ensured in the study. Ethical principles were adhered to during the research process.

  4. The University and the Community: Planning for an Alternative Form of Educational Service Delivery.

    Science.gov (United States)

    Strickland, Wayne G.

    1980-01-01

    The planning process and marketing strategy adopted by a large urban postsecondary institution investigating the feasibility of developing a branch campus is described. Among the planning elements were a market analysis and citizen interest survey. (MSE)

  5. Dynamics of poroelastic foams

    Science.gov (United States)

    Forterre, Yoel; Sobac, Benjamin

    2010-11-01

    Soft poroelastic structures are widespread in biological tissues such as cartilaginous joints in bones, blood-filled placentae or plant organs. Here we investigate the dynamics of open elastic foams immersed in viscous fluids, as model soft poroelastic materials. The experiment consists in slowly compacting blocs of polyurethane solid foam embedded in silicon oil-tanks and studying their relaxation to equilibrium when the confining stress is suddenly released. Measurements of the local fluid pressure and foam velocity field are compared with a simple two-phase flow approach. For small initial compactions, the results show quantitative agreement with the classical diffusion theory of soil consolidation (Terzaghi, Biot). On the other hand, for large initial compactions, the dynamics exhibits long relaxation times and decompaction fronts, which are mainly controlled by the highly non-linear mechanical response of the foam. The analogy between this process and the evaporation of a polymer melt close to the glass transition will be briefly discussed.

  6. Thermal Conductivity of Foam Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    Due to the increased focus on energy savings and waste recycling foam glass materials have gained increased attention. The production process of foam glass is a potential low-cost recycle option for challenging waste, e.g. CRT glass and industrial waste (fly ash and slags). Foam glass is used...... as thermal insulating material in building and chemical industry. The large volume of gas (porosity 90 – 95%) is the main reason of the low thermal conductivity of the foam glass. If gases with lower thermal conductivity compared to air are entrapped in the glass melt, the derived foam glass will contain...... only closed pores and its overall thermal conductivity will be much lower than that of the foam glass with open pores. In this work we have prepared foam glass using different types of recycled glasses and different kinds of foaming agents. This enabled the formation of foam glasses having gas cells...

  7. Adaptive Liver Stereotactic Body Radiation Therapy: Automated Daily Plan Reoptimization Prevents Dose Delivery Degradation Caused by Anatomy Deformations

    Energy Technology Data Exchange (ETDEWEB)

    Leinders, Suzanne M. [Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Delft University of Technology, Delft (Netherlands); Breedveld, Sebastiaan; Méndez Romero, Alejandra [Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Schaart, Dennis [Delft University of Technology, Delft (Netherlands); Seppenwoolde, Yvette, E-mail: y.seppenwoolde@erasmusmc.nl [Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Heijmen, Ben J.M. [Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2013-12-01

    Purpose: To investigate how dose distributions for liver stereotactic body radiation therapy (SBRT) can be improved by using automated, daily plan reoptimization to account for anatomy deformations, compared with setup corrections only. Methods and Materials: For 12 tumors, 3 strategies for dose delivery were simulated. In the first strategy, computed tomography scans made before each treatment fraction were used only for patient repositioning before dose delivery for correction of detected tumor setup errors. In adaptive second and third strategies, in addition to the isocenter shift, intensity modulated radiation therapy beam profiles were reoptimized or both intensity profiles and beam orientations were reoptimized, respectively. All optimizations were performed with a recently published algorithm for automated, multicriteria optimization of both beam profiles and beam angles. Results: In 6 of 12 cases, violations of organs at risk (ie, heart, stomach, kidney) constraints of 1 to 6 Gy in single fractions occurred in cases of tumor repositioning only. By using the adaptive strategies, these could be avoided (<1 Gy). For 1 case, this needed adaptation by slightly underdosing the planning target volume. For 2 cases with restricted tumor dose in the planning phase to avoid organ-at-risk constraint violations, fraction doses could be increased by 1 and 2 Gy because of more favorable anatomy. Daily reoptimization of both beam profiles and beam angles (third strategy) performed slightly better than reoptimization of profiles only, but the latter required only a few minutes of computation time, whereas full reoptimization took several hours. Conclusions: This simulation study demonstrated that replanning based on daily acquired computed tomography scans can improve liver stereotactic body radiation therapy dose delivery.

  8. Energy modulated electron therapy: Design, implementation, and evaluation of a novel method of treatment planning and delivery

    Science.gov (United States)

    Al-Yahya, Khalid

    Energy modulated electron therapy (EMET) is a promising treatment modality that has the fundamental capabilities to enhance the treatment planning and delivery of superficially located targets. Although it offers advantages over x-ray intensity modulated radiation therapy (IMRT), EMET has not been widely implemented to the same level of accuracy, automation, and clinical routine as its x-ray counterpart. This lack of implementation is attributed to the absence of a remotely automated beam shaping system as well as the deficiency in dosimetric accuracy of clinical electron pencil beam algorithms in the presence of beam modifiers and tissue heterogeneities. In this study, we present a novel technique for treatment planning and delivery of EMET. The delivery is achieved using a prototype of an automated "few leaf electron collimator" (FLEC). It consists of four copper leaves driven by stepper motors which are synchronized with the x-ray jaws in order to form a series of collimated rectangular openings or "fieldlets". Based on Monte Carlo studies, the FLEC has been designed to serve as an accessory tool to the current accelerator equipment. The FLEC was constructed and its operation was fully automated and integrated with the accelerator through an in-house assembled control unit. The control unit is a portable computer system accompanied with customized software that delivers EMET plans after acquiring them from the optimization station. EMET plans are produced based on dose volume constraints that employ Monte Carlo pre-generated and patient-specific kernels which are utilized by an in-house developed optimization algorithm. The structure of the optimization software is demonstrated. Using Monte Carlo techniques to calculate dose allows for accurate modeling of the collimation system as well as the patient heterogeneous geometry and take into account their impact on optimization. The Monte Carlo calculations were validated by comparing them against output

  9. Analysis of Tube Bank Heat Transfer In Downward Directed Foam Flow

    Directory of Open Access Journals (Sweden)

    Jonas Gylys

    2004-06-01

    Full Text Available Apparatus with the foam flow are suitable to use in different technologies like heat exchangers, food industry, chemical and oil processing industry. Statically stable liquid foam until now is used in technologic systems rather seldom. Although a usage of this type of foam as heat transfer agent in foam equipment has a number of advantages in comparison with one phase liquid equipment: small quantity of liquid is required, heat transfer rate is rather high, mass of equipment is much smaller, energy consumption for foam delivery into heat transfer zone is lower. The paper analyzes the peculiarities of heat transfer from distributed in staggered order and perpendicular to foam flow in channel of rectangular cross section tube bundle to the foam flow. It was estimated the dependence of mean gas velocity and volumetric void fraction of foam flow to heat transfer in downward foam flow. Significant difference of heat transfer intensity from front and back tubes of tube row in laminar foam flow was noticed. Dependence of heat transfer on flow velocity and volumetric void fraction of foam was confirmed and estimated by criterion equations.

  10. Challenging the Courtesy Bias Interpretation of Favorable Clients' Perceptions of Family Planning Delivery

    Science.gov (United States)

    Len, Federico R.; Lundgren, Rebecka; Huapaya, Ana; Sinai, Irit; Jennings, Victoria

    2007-01-01

    Favorable client perceptions of provider's interpersonal behavior in contraceptive delivery, documented in clinic exit questionnaires, appear to contradict results from qualitative evaluations and are attributed to clients' courtesy bias. In this study, trained simulated clients requested services from Ministry of Health providers in three…

  11. mdFoam+: Advanced molecular dynamics in OpenFOAM

    Science.gov (United States)

    Longshaw, S. M.; Borg, M. K.; Ramisetti, S. B.; Zhang, J.; Lockerby, D. A.; Emerson, D. R.; Reese, J. M.

    2018-03-01

    This paper introduces mdFoam+, which is an MPI parallelised molecular dynamics (MD) solver implemented entirely within the OpenFOAM software framework. It is open-source and released under the same GNU General Public License (GPL) as OpenFOAM. The source code is released as a publicly open software repository that includes detailed documentation and tutorial cases. Since mdFoam+ is designed entirely within the OpenFOAM C++ object-oriented framework, it inherits a number of key features. The code is designed for extensibility and flexibility, so it is aimed first and foremost as an MD research tool, in which new models and test cases can be developed and tested rapidly. Implementing mdFoam+ in OpenFOAM also enables easier development of hybrid methods that couple MD with continuum-based solvers. Setting up MD cases follows the standard OpenFOAM format, as mdFoam+ also relies upon the OpenFOAM dictionary-based directory structure. This ensures that useful pre- and post-processing capabilities provided by OpenFOAM remain available even though the fully Lagrangian nature of an MD simulation is not typical of most OpenFOAM applications. Results show that mdFoam+ compares well to another well-known MD code (e.g. LAMMPS) in terms of benchmark problems, although it also has additional functionality that does not exist in other open-source MD codes.

  12. TH-AB-201-12: Using Machine Log-Files for Treatment Planning and Delivery QA

    Energy Technology Data Exchange (ETDEWEB)

    Stanhope, C [Beaumont Health System, Royal Oak MI and Wayne State University, Detroit, MI (United States); Liang, J; Drake, D; Yan, D [Beaumont Health System, Royal Oak, MI (United States)

    2016-06-15

    Purpose: To determine the segment reduction and dose resolution necessary for machine log-files to effectively replace current phantom-based patient-specific quality assurance, while minimizing computational cost. Methods: Elekta’s Log File Convertor R3.2 records linac delivery parameters (dose rate, gantry angle, leaf position) every 40ms. Five VMAT plans [4 H&N, 1 Pulsed Brain] comprised of 2 arcs each were delivered on the ArcCHECK phantom. Log-files were reconstructed in Pinnacle on the phantom geometry using 1/2/3/4° control point spacing and 2/3/4mm dose grid resolution. Reconstruction effectiveness was quantified by comparing 2%/2mm gamma passing rates of the original and log-file plans. Modulation complexity scores (MCS) were calculated for each beam to correlate reconstruction accuracy and beam modulation. Percent error in absolute dose for each plan-pair combination (log-file vs. ArcCHECK, original vs. ArcCHECK, log-file vs. original) was calculated for each arc and every diode greater than 10% of the maximum measured dose (per beam). Comparing standard deviations of the three plan-pair distributions, relative noise of the ArcCHECK and log-file systems was elucidated. Results: The original plans exhibit a mean passing rate of 95.1±1.3%. The eight more modulated H&N arcs [MCS=0.088±0.014] and two less modulated brain arcs [MCS=0.291±0.004] yielded log-file pass rates most similar to the original plan when using 1°/2mm [0.05%±1.3% lower] and 2°/3mm [0.35±0.64% higher] log-file reconstructions respectively. Log-file and original plans displayed percent diode dose errors 4.29±6.27% and 3.61±6.57% higher than measurement. Excluding the phantom eliminates diode miscalibration and setup errors; log-file dose errors were 0.72±3.06% higher than the original plans – significantly less noisy. Conclusion: For log-file reconstructed VMAT arcs, 1° control point spacing and 2mm dose resolution is recommended, however, less modulated arcs may allow less

  13. Applications of Foamed Lightweight Concrete

    Directory of Open Access Journals (Sweden)

    Mohd Sari Kamarul Aini

    2017-01-01

    Full Text Available Application of foamed concrete is increasing at present due to high demand on foamed concrete structures with good mechanical and physical properties. This paper discusses on the use of basic raw materials, their characteristics, production process, and their application in foamed lightweight concrete with densities between 300 kg/m3 and 1800 kg/m3. It also discusses the factors that influence the strengths and weaknesses of foamed concrete based on studies that were conducted previously.

  14. Dielectric and Radiative Properties of Sea Foam at Microwave Frequencies: Conceptual Understanding of Foam Emissivity

    OpenAIRE

    Peter W. Gaiser; Magdalena D. Anguelova

    2012-01-01

    Foam fraction can be retrieved from space-based microwave radiometric data at frequencies from 1 to 37 GHz. The retrievals require modeling of ocean surface emissivity fully covered with sea foam. To model foam emissivity well, knowledge of foam properties, both mechanical and dielectric, is necessary because these control the radiative processes in foam. We present a physical description of foam dielectric properties obtained from the foam dielectric constant including foam skin depth; foam ...

  15. Foams in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Marsden, S.S.

    1986-07-01

    In 1978 a literature search on selective blocking of fluid flow in porous media was done by Professor S.S. Marsden and two of his graduate students, Tom Elson and Kern Huppy. This was presented as SUPRI Report No. TR-3 entitled ''Literature Preview of the Selected Blockage of Fluids in Thermal Recovery Projects.'' Since then a lot of research on foam in porous media has been done on the SUPRI project and a great deal of new information has appeared in the literature. Therefore we believed that a new, up-to-date search should be done on foam alone, one which would be helpful to our students and perhaps of interest to others. This is a chronological survey showing the development of foam flow, blockage and use in porous media, starting with laboratory studies and eventually getting into field tests and demonstrations. It is arbitrarily divided into five-year time periods. 81 refs.

  16. Countywide Evaluation of the Long-Term Family Self-Sufficiency Plan. Assessing the Utility of the LTFSS Plan Service Delivery and Planning Framework

    National Research Council Canada - National Science Library

    Davis, Lois

    2002-01-01

    ...) Plan on November 16,1999. The LTFSS Plan consists of 46 projects whose goal is to promote self-sufficiency among families that are participating in the California Work Opportunity and Responsibility to Kids Act of 1997 (CalWORKS...

  17. Long lasting decontamination foam

    Science.gov (United States)

    Demmer, Ricky L.; Peterman, Dean R.; Tripp, Julia L.; Cooper, David C.; Wright, Karen E.

    2010-12-07

    Compositions and methods for decontaminating surfaces are disclosed. More specifically, compositions and methods for decontamination using a composition capable of generating a long lasting foam are disclosed. Compositions may include a surfactant and gelatin and have a pH of less than about 6. Such compositions may further include affinity-shifting chemicals. Methods may include decontaminating a contaminated surface with a composition or a foam that may include a surfactant and gelatin and have a pH of less than about 6.

  18. SU-E-P-27: Efficient Process for AccuBoost Planning and Treatment Delivery to Minimize Patient Compression Time

    Energy Technology Data Exchange (ETDEWEB)

    Iftimia, I; Talmadge, M; Halvorsen, P [Lahey Clinic, Burlington, MA (United States)

    2015-06-15

    Purpose: To implement an efficient and robust process for AccuBoost planning and treatment delivery that can be safely performed by a single Physicist while minimizing patient’s total session time. Methods: Following a thorough commissioning and validation process, templates were created in the brachytherapy planning system for each AccuBoost applicator. Tables of individual and total nominal dwell times for each applicator as a function of separation were generated to streamline planning while an Excel-based nomogram provided by the vendor functions as a secondary verification of the treatment parameters. Tables of surface dose as a function of separation and applicator, along with concise guidance documents for applicator selection, are readily available during the planning process. The entire process is described in a set of detailed Standard Operating Procedures which, in addition to the items described above, include a verbal time-out between the primary planner and the individual performing the secondary verification as well as direct visual confirmation of applicator placement using an articulated mirror. Prior to treatment initiation, a final time-out is conducted with the Radiation Oncologist. Chart documentation is finalized after the patient is released from compression following completion of the treatment. Results: With the aforementioned procedures, it has been possible to consistently limit the time required to prepare each treatment such that the patient is typically under compression for less than 10 minutes per orientation prior to the initiation of the treatment, which is particularly important for APBI cases. This process can be overseen by a single physicist assisted by a dosimetrist and has been optimized during the past 16 months, with 180 treatment sessions safely completed to date. Conclusion: This work demonstrates the implementation of an efficient and robust process for real-time-planned AccuBoost treatments that effectively minimizes

  19. Production of lightweight foam glass (invited talk)

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    The foam glass production allows low cost recycling of postconsumer glass and industrial waste materials as foaming agent or as melt resource. Foam glass is commonly produced by utilising milled glass mixed with a foaming agent. The powder mixture is heat-treated to around 10^3.7 – 10^6 Pa s, which...... result in viscous sintering and subsequent foaming of the glass melt. The porous glass melt is cooled down to room temperature to freeze-in the foam structure. The resulting foam glass is applied in constructions as a light weight material to reduce load bearing capacity and as heat insulating material...... in buildings and industry. We foam panel glass from old televisions with different foaming agents. We discuss the foaming ability and the foaming mechanism of different foaming systems. We compare several studies to define a viscous window for preparing low density foam glass. However, preparing foam glass...

  20. Project W-521, waste feed delivery systems environmental permits and approvals plan

    International Nuclear Information System (INIS)

    TOLLEFSON, K.S.

    1999-01-01

    This document has been prepared to define the specific environmental requirements applicable to Project W-521. The document describes the permits and approvals necessary for the project to design, construct, and install planned upgrades, and provides a schedule of activities and provides cost estimates to complete the required permitting and approval activities

  1. River Protection Project waste feed delivery program technical performance measurement assessment plan

    International Nuclear Information System (INIS)

    O'TOOLE, S.M.

    1999-01-01

    This plan establishes a formal technical performance-monitoring program. Technical performance is assessed by establishing requirements based performance goals at the beginning of a program and routinely evaluating progress in meeting these goals at predetermined milestones throughout the project life cycle

  2. The feasibility of using Pareto fronts for comparison of treatment planning systems and delivery techniques

    DEFF Research Database (Denmark)

    Ottosson, Rickard O; Engstrom, Per E; Sjöström, David

    2008-01-01

    constitute the Pareto front. The Pareto concept applies well to the inverse planning process, which involves inherently contradictory objectives, high and uniform target dose on one hand, and sparing of surrounding tissue and nearby organs at risk (OAR) on the other. Due to the specific characteristics...

  3. Improving CT quality with optimized image parameters for radiation treatment planning and delivery guidance

    Directory of Open Access Journals (Sweden)

    Guang-Pei Chen

    2017-10-01

    Conclusion: CT image quality can be improved with the IQE protocols created in this study, to provide better soft tissue contrast, which would be beneficial for use in radiation therapy, e.g., for planning data acquisition or for IGRT for hypo-fractionated treatments.

  4. Tensile Properties of Open Cell Ceramic Foams

    Czech Academy of Sciences Publication Activity Database

    Dlouhý, Ivo; Řehořek, Lukáš; Chlup, Zdeněk

    2009-01-01

    Roč. 409, - (2009), s. 168-175 ISSN 1013-9826. [Fractography of Advanced Ceramics /3./. Stará Lesná, 07.09.2008-10.09.2008] R&D Projects: GA ČR(CZ) GA106/06/0724; GA ČR GD106/05/H008 Institutional research plan: CEZ:AV0Z20410507 Keywords : tensile test * ceramics foam * open porosity * tensile strength Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass

  5. Tensile Behaviour of Open Cell Ceramic Foams

    Czech Academy of Sciences Publication Activity Database

    Řehořek, Lukáš; Dlouhý, Ivo; Chlup, Zdeněk

    2009-01-01

    Roč. 53, č. 4 (2009), s. 237-241 ISSN 0862-5468 R&D Projects: GA ČR GA101/09/1821; GA ČR GD106/09/H035 Institutional research plan: CEZ:AV0Z20410507 Keywords : Tensile test * Ceramics foam * Open porosity * Tensile strength Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.649, year: 2009

  6. Flexible polyurethane foams

    NARCIS (Netherlands)

    2012-01-01

    Embodiments of the invention provide for a method of preparing a polyurethane foam, including reacting least one initiator comprising at least two hydroxyl groups with at least one 12-hydroxystearic acid to form at least one polyester polyol, reacting the at least one polyester polyol with at least

  7. Serving our communities better. Guidelines for planning and developing integrated delivery networks.

    Science.gov (United States)

    Prybil, L; Golden, P; Ballance, X

    1995-04-01

    In 1994 the Daughters of Charity National Health System-East Central (DCNHS-East Central) adopted 11 guidelines to help corporate staff and local leaders plan and develop integrated networks. Guideline 1 emphasizes needs-based strategic planning. Guideline 2 focuses on the community-based network planning process, recommending a team approach and ongoing communication with the local ordinary. In guidelines 3 through 5, the DCNHS-East Central Board of Directors spells out key issues that must be covered in proposals ultimately presented for governance action. Guideline 6 presents three core elements that should characterize all CBNs in which DCNHS-East Central institutions participate. Guideline 7 emphasizes that all CBN proposals and agreements must be clear with respect to the Catholic identity of DCNHS-East Central institutions. Guidelines 8 and 9 require that proposed changes to traditional policies and management practices be explicit in CBN proposals. The tenth guideline requires that all CBN proposals indicate an explicit evaluation function. The final guideline underscores that regardless of the strategic fit or how well a CBN is designed, it is unlikely to succeed unless both internal and external relationships are based on a solid foundation of honesty, mutual respect, and trust.

  8. Foam, Foam-resin composite and method of making a foam-resin composite

    Science.gov (United States)

    Cranston, John A. (Inventor); MacArthur, Doug E. (Inventor)

    1995-01-01

    This invention relates to a foam, a foam-resin composite and a method of making foam-resin composites. The foam set forth in this invention comprises a urethane modified polyisocyanurate derived from an aromatic amino polyol and a polyether polyol. In addition to the polyisocyanurate foam, the composite of this invention further contains a resin layer, wherein the resin may be epoxy, bismaleimide, or phenolic resin. Such resins generally require cure or post-cure temperatures of at least 350.degree. F.

  9. The impacts of dental filling materials on RapidArc treatment planning and dose delivery: Challenges and solution

    Energy Technology Data Exchange (ETDEWEB)

    Mail, Noor; Al-Ghamdi, S.; Saoudi, A. [Princess Norah Oncology Center, National Guard Health Affairs, Jeddah 21423, Saudi Arabia and King Abdullah International Medical Research Center, Jeddah 21423 (Saudi Arabia); Albarakati, Y.; Ahmad Khan, M.; Saeedi, F.; Safadi, N. [Princess Norah Oncology Center, National Guard Health Affairs, Jeddah 21423 (Saudi Arabia)

    2013-08-15

    Purpose: The presence of high-density material in the oral cavity creates dose perturbation in both downstream and upstream directions at the surfaces of dental filling materials (DFM). In this study, the authors have investigated the effect of DFM on head and neck RapidArc treatment plans and delivery. Solutions are proposed to address (1) the issue of downstream dose perturbation, which might cause target under dosage, and (2) to reduce the upstream dose from DFM which may be the primary source of mucositis. In addition, an investigation of the clinical role of a custom-made plastic dental mold/gutter (PDM) in sparing the oral mucosa and tongue reaction is outlined.Methods: The influence of the dental filling artifacts on dose distribution was investigated using a geometrically well-defined head and neck intensity modulated radiation therapy (IMRT) verification phantom (PTW, Freiberg, Germany) with DFM inserts called amalgam, which contained 50% mercury, 25% silver, 14% tin, 8% copper, and 3% other trace metals. Three RapidArc plans were generated in the Varian Eclipse System to treat the oral cavity using the same computer tomography (CT) dataset, including (1) a raw CT image, (2) a streaking artifacts region, which was replaced with a mask of 10 HU, and (3) a 2 cm-thick 6000 HU virtual filter [a volume created in treatment planning system to compensate for beam attenuation, where the thickness of this virtual filter is based on the measured percent depth dose (PDD) data and Eclipse calculation]. The dose delivery for the three plans was verified using Gafchromic-EBT2 film measurements. The custom-made PDM technique to reduce backscatter dose was clinically tested on four head and neck cancer patients (T3, N1, M0) with DFM, two patients with PDM and the other two patients without PDM. The thickness calculation of the PDM toward the mucosa and tongue was purely based on the measured upstream dose. Patients’ with oral mucosal reaction was clinically examined

  10. The impacts of dental filling materials on RapidArc treatment planning and dose delivery: Challenges and solution

    International Nuclear Information System (INIS)

    Mail, Noor; Al-Ghamdi, S.; Saoudi, A.; Albarakati, Y.; Ahmad Khan, M.; Saeedi, F.; Safadi, N.

    2013-01-01

    Purpose: The presence of high-density material in the oral cavity creates dose perturbation in both downstream and upstream directions at the surfaces of dental filling materials (DFM). In this study, the authors have investigated the effect of DFM on head and neck RapidArc treatment plans and delivery. Solutions are proposed to address (1) the issue of downstream dose perturbation, which might cause target under dosage, and (2) to reduce the upstream dose from DFM which may be the primary source of mucositis. In addition, an investigation of the clinical role of a custom-made plastic dental mold/gutter (PDM) in sparing the oral mucosa and tongue reaction is outlined.Methods: The influence of the dental filling artifacts on dose distribution was investigated using a geometrically well-defined head and neck intensity modulated radiation therapy (IMRT) verification phantom (PTW, Freiberg, Germany) with DFM inserts called amalgam, which contained 50% mercury, 25% silver, 14% tin, 8% copper, and 3% other trace metals. Three RapidArc plans were generated in the Varian Eclipse System to treat the oral cavity using the same computer tomography (CT) dataset, including (1) a raw CT image, (2) a streaking artifacts region, which was replaced with a mask of 10 HU, and (3) a 2 cm-thick 6000 HU virtual filter [a volume created in treatment planning system to compensate for beam attenuation, where the thickness of this virtual filter is based on the measured percent depth dose (PDD) data and Eclipse calculation]. The dose delivery for the three plans was verified using Gafchromic-EBT2 film measurements. The custom-made PDM technique to reduce backscatter dose was clinically tested on four head and neck cancer patients (T3, N1, M0) with DFM, two patients with PDM and the other two patients without PDM. The thickness calculation of the PDM toward the mucosa and tongue was purely based on the measured upstream dose. Patients’ with oral mucosal reaction was clinically examined

  11. Domestic water service delivery indicators and frameworks for monitoring, evaluation, policy and planning: a review.

    Science.gov (United States)

    Kayser, Georgia L; Moriarty, Patrick; Fonseca, Catarina; Bartram, Jamie

    2013-10-11

    Monitoring of water services informs policy and planning for national governments and the international community. Currently, the international monitoring system measures the type of drinking water source that households use. There have been calls for improved monitoring systems over several decades, some advocating use of multiple indicators. We review the literature on water service indicators and frameworks with a view to informing debate on their relevance to national and international monitoring. We describe the evidence concerning the relevance of each identified indicator to public health, economic development and human rights. We analyze the benefits and challenges of using these indicators separately and combined in an index as tools for planning, monitoring, and evaluating water services. We find substantial evidence on the importance of each commonly recommended indicator--service type, safety, quantity, accessibility, reliability or continuity of service, equity, and affordability. Several frameworks have been proposed that give structure to the relationships among individual indicators and some combine multiple indicator scores into a single index but few have been rigorously tested. More research is needed to understand if employing a composite metric of indicators is advantageous and how each indicator might be scored and scaled.

  12. Domestic Water Service Delivery Indicators and Frameworks for Monitoring, Evaluation, Policy and Planning: A Review

    Directory of Open Access Journals (Sweden)

    Jamie Bartram

    2013-10-01

    Full Text Available Monitoring of water services informs policy and planning for national governments and the international community. Currently, the international monitoring system measures the type of drinking water source that households use. There have been calls for improved monitoring systems over several decades, some advocating use of multiple indicators. We review the literature on water service indicators and frameworks with a view to informing debate on their relevance to national and international monitoring. We describe the evidence concerning the relevance of each identified indicator to public health, economic development and human rights. We analyze the benefits and challenges of using these indicators separately and combined in an index as tools for planning, monitoring, and evaluating water services. We find substantial evidence on the importance of each commonly recommended indicator—service type, safety, quantity, accessibility, reliability or continuity of service, equity, and affordability. Several frameworks have been proposed that give structure to the relationships among individual indicators and some combine multiple indicator scores into a single index but few have been rigorously tested. More research is needed to understand if employing a composite metric of indicators is advantageous and how each indicator might be scored and scaled.

  13. Challenges, problems and possible solutions in wind generator systems from the aspect of forecast, planning and delivery of wind energy

    International Nuclear Information System (INIS)

    Giovski, Nikola

    2014-01-01

    The fundamental difficulties of integrating wind energy into the power system arise from its large temporal variability and limited predictability. That's why the integration of wind power presents major challenge for today's operating and planning practices of the power system operators. Accurate predictions of the possible wind power output, in time intervals relevant for creating schedules for production and exchange capacity, allows to system operators and dispatching personnel more efficient power system management. Despite the challenges and problems that arise due to integration of wind power into power systems, which need to be solved or reduced, wind power has its advantages that should be utilized. The effective integration of wind power plants into the transmission grid should allow them to represent the backbone of future energy systems. Modern wind generators represent production units that have the ability to participate in the management of energy systems e.g. in the regulation of frequency, voltage and other network operating requirements. This paper provides a brief overview of global experiences with the challenges, problems and possible solutions that appear in wind generator systems from the aspect of forecasting, planning and delivery of wind energy. (author)

  14. SU-F-T-522: Dosimetric Study of Junction Dose in Double Isocenter Flatten and Flatten Filter Free IMRT and VMAT Plan Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Samuvel, K; Yadav, G; Bhushan, M; Tamilarasu, S; Kumar, L; Suhail, M [Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, Delhi (India)

    2016-06-15

    Purpose: To quantify the dosimetric accuracy of junction dose in double isocenter flattened and flatten filter free(FFF) intensity modulated radiation therapy(IMRT) and volumetric modulated arc therapy(VMAT) plan delivery using pelvis phantom. Methods: Five large field pelvis patients were selected for this study. Double isocenter IMRT and VMAT treatment plans were generated in Eclipse Treatment planning System (V.11.0) using 6MV FB and FFF beams. For all the plans same distance 17.0cm was kept between one isocenter to another isocenter. IMRT Plans were made with 7 coplanar fields and VMAT plans were made with full double arcs. Dose calculation was performed using AAA algorithms with dose grid size of 0.25 cm. Verification plans were calculated on Scanditronix Wellhofer pelvis slab phantom. Measurement point was selected and calculated, where two isocenter plan fields are overlapping, this measurement point was kept at distance 8.5cm from both isocenter. The plans were delivered using Varian TrueBeamTM machine on pelvis slab phantom. Point dose measurements was carried out using CC13 ion chamber volume of 0.13cm3. Results: The measured junction point dose are compared with TPS calculated dose. The mean difference observed was 4.5%, 6.0%, 4.0% and 7.0% for IMRT-FB,IMRT-FFF, VMAT-FB and VMAT-FFF respectively. The measured dose results shows closer agreement with calculated dose in Flatten beam planning in both IMRT and VMAT, whereas in FFF beam plan dose difference are more compared with flatten beam plan. Conclusion: Dosimetry accuracy of Large Field junction dose difference was found less in Flatten beam compared with FFF beam plan delivery. Even though more dosimetric studies are required to analyse junction dose for FFF beam planning using multiple point dose measurements and fluence map verification in field junction area.

  15. Development and delivery of a workshop methodology: planning for biomass power plant projects

    Energy Technology Data Exchange (ETDEWEB)

    Gray, A.J.; Delbridge, P.; Trevorrow, E.; Pile, C.

    2001-07-01

    This report gives details of the approach used to develop a workshop methodology to help planners and stakeholders address key issues that may arise when submitting a planning application for a biomass power plant in the light of the UK government's energy and climate change targets. The results of interviews with stakeholders (central government, regulatory authorities, developers, planners, non-governmental organisations, local community, resident groups) are summarised, and the NIMBY (not in my back yard) syndrome, the lack of trust in the developer, and lack of awareness of the use of biomass are discussed. Details are given of the design and testing of the workshop methodology and the resulting workshop methodology and workbook guide aimed at understanding the stakeholder issues and concerns through stakeholder discussions.

  16. INIS strategic planning and INIS Clearinghouse document delivery: from four weeks to four minutes

    International Nuclear Information System (INIS)

    Levine, Emil; St-Pierre, Germain

    2015-01-01

    I joined INIS in May 1994 as a consultant to create a Strategic Plan for 1995–2000. I had left a US Department of Justice contractor, Aspen Corporation, which operated the National Criminal Justice Reference Service (NCJRS), as chief of two libraries and manager of a clearinghouse for the world’s criminal justice literature. NCJRS collected this literature, created a bibliographic on-line database and converted non-copyrighted literature to microfiche. The government contract had to be renewed every five years and the Aspen proposal was basically a five year strategic plan, to which I contributed. Thus, when I came to INIS, I had an understanding of the process. The next six months were devoted to preparing STRATEGIC GUIDELINES FOR INIS DEVELOPMENTS 1995–2000 with the caveat: Notice: The guidelines proposed in this report are those of the Information Consultant. They represent a wide range of options that are being presented for further refinement by Peer Reviewers, INIS Consultants and finally the Advisory Committee for INIS. Forwarding of these guidelines does not represent concurrence or nonconcurrence by the INIS Secretariat. 30 September 1994. Member States are now collecting and submitting most of their NCL in electronic format. It is sent to INIS for quality control and consolidation. Consequently, INIS staff has been gradually reduced. The amount of NCL disseminated has remained constant, and an ongoing process to digitize the entire INIS collection on microfiche will be completed in 2016, a process I started in 1999. Before leaving INIS in 1999, I realized that the future would provide a reduced requirement for INIS imaging and recommended the Clearinghouse become a resource for all of the IAEA. Today it serves that purpose

  17. TU-FG-201-03: Automatic Pre-Delivery Verification Using Statistical Analysis of Consistencies in Treatment Plan Parameters by the Treatment Site and Modality

    International Nuclear Information System (INIS)

    Liu, S; Wu, Y; Chang, X; Li, H; Yang, D

    2016-01-01

    Purpose: A novel computer software system, namely APDV (Automatic Pre-Delivery Verification), has been developed for verifying patient treatment plan parameters right prior to treatment deliveries in order to automatically detect and prevent catastrophic errors. Methods: APDV is designed to continuously monitor new DICOM plan files on the TMS computer at the treatment console. When new plans to be delivered are detected, APDV checks the consistencies of plan parameters and high-level plan statistics using underlying rules and statistical properties based on given treatment site, technique and modality. These rules were quantitatively derived by retrospectively analyzing all the EBRT treatment plans of the past 8 years at authors’ institution. Therapists and physicists will be notified with a warning message displayed on the TMS computer if any critical errors are detected, and check results, confirmation, together with dismissal actions will be saved into database for further review. Results: APDV was implemented as a stand-alone program using C# to ensure required real time performance. Mean values and standard deviations were quantitatively derived for various plan parameters including MLC usage, MU/cGy radio, beam SSD, beam weighting, and the beam gantry angles (only for lateral targets) per treatment site, technique and modality. 2D-based rules of combined MU/cGy ratio and averaged SSD values were also derived using joint probabilities of confidence error ellipses. The statistics of these major treatment plan parameters quantitatively evaluate the consistency of any treatment plans which facilitates automatic APDV checking procedures. Conclusion: APDV could be useful in detecting and preventing catastrophic errors immediately before treatment deliveries. Future plan including automatic patient identify and patient setup checks after patient daily images are acquired by the machine and become available on the TMS computer. This project is supported by the

  18. TU-FG-201-03: Automatic Pre-Delivery Verification Using Statistical Analysis of Consistencies in Treatment Plan Parameters by the Treatment Site and Modality

    Energy Technology Data Exchange (ETDEWEB)

    Liu, S; Wu, Y; Chang, X; Li, H; Yang, D [Washington University School of Medicine, St. Louis, MO (United States)

    2016-06-15

    Purpose: A novel computer software system, namely APDV (Automatic Pre-Delivery Verification), has been developed for verifying patient treatment plan parameters right prior to treatment deliveries in order to automatically detect and prevent catastrophic errors. Methods: APDV is designed to continuously monitor new DICOM plan files on the TMS computer at the treatment console. When new plans to be delivered are detected, APDV checks the consistencies of plan parameters and high-level plan statistics using underlying rules and statistical properties based on given treatment site, technique and modality. These rules were quantitatively derived by retrospectively analyzing all the EBRT treatment plans of the past 8 years at authors’ institution. Therapists and physicists will be notified with a warning message displayed on the TMS computer if any critical errors are detected, and check results, confirmation, together with dismissal actions will be saved into database for further review. Results: APDV was implemented as a stand-alone program using C# to ensure required real time performance. Mean values and standard deviations were quantitatively derived for various plan parameters including MLC usage, MU/cGy radio, beam SSD, beam weighting, and the beam gantry angles (only for lateral targets) per treatment site, technique and modality. 2D-based rules of combined MU/cGy ratio and averaged SSD values were also derived using joint probabilities of confidence error ellipses. The statistics of these major treatment plan parameters quantitatively evaluate the consistency of any treatment plans which facilitates automatic APDV checking procedures. Conclusion: APDV could be useful in detecting and preventing catastrophic errors immediately before treatment deliveries. Future plan including automatic patient identify and patient setup checks after patient daily images are acquired by the machine and become available on the TMS computer. This project is supported by the

  19. Aerosol-foam interaction experiments

    International Nuclear Information System (INIS)

    Ball, M.H.E.; Luscombe, C.DeM.; Mitchell, J.P.

    1990-03-01

    Foam treatment offers the potential to clean gas streams containing radioactive particles. A large decontamination factor has been claimed for the removal of airborne plutonium dust when spraying a commercially available foam on the walls and horizontal surfaces of an alpha-active room. Experiments have been designed and undertaken to reproduce these conditions with a non-radioactive simulant aerosol. Careful measurements of aerosol concentrations with and without foam treatment failed to provide convincing evidence to support the earlier observation. The foam may not have been as well mixed with the aerosol in the present studies. Further work is required to explore more efficient mixing methods, including systems in which the aerosol steam is passed through the foam, rather than merely spraying foam into the path of the aerosol. (author)

  20. Chaotic bubbling and nonstagnant foams.

    Science.gov (United States)

    Tufaile, Alberto; Sartorelli, José Carlos; Jeandet, Philippe; Liger-Belair, Gerard

    2007-06-01

    We present an experimental investigation of the agglomeration of bubbles obtained from a nozzle working in different bubbling regimes. This experiment consists of a continuous production of bubbles from a nozzle at the bottom of a liquid column, and these bubbles create a two-dimensional (2D) foam (or a bubble raft) at the top of this column. The bubbles can assemble in various dynamically stable arrangement, forming different kinds of foams in a liquid mixture of water and glycerol, with the effect that the bubble formation regimes influence the foam obtained from this agglomeration of bubbles. The average number of bubbles in the foam is related to the bubble formation frequency and the bubble mean lifetime. The periodic bubbling can generate regular or irregular foam, while a chaotic bubbling only generates irregular foam.

  1. Foams structure and dynamics

    CERN Document Server

    Cantat, Isabelle; Graner, François; Pitois, Olivier; Höhler, Reinard; Elias, Florence; Saint-Jalmes, Arnaud; Rouyer, Florence

    2013-01-01

    This book is the first to provide a thorough description of all aspects of the physico-chemical properties of foams. It sets out what is known about their structure, their stability, and their rheology. Engineers, researchers and students will find descriptions of all the key concepts, illustrated by numerous applications, as well as experiments and exercises for the reader. A solutions manual for lecturers is available via the publisher's web site.

  2. Pourable Foam Insulation

    Science.gov (United States)

    Harvey, James A.; Butler, John M.; Chartoff, Richard P.

    1989-01-01

    Report describes search for polyisocyanurate/polyurethane foam insulation with superior characteristics. Discusses chemistry of current formulations. Tests of formulations, of individual ingredients and or alternative new formulations described. Search revealed commercially available formulations exhibiting increased thermal stability at temperatures up to 600 degree C, pours readily before curing, presents good appearance after curing, and remains securely bonded to aluminum at cryogenic temperatures. Total of 42 different formulations investigated, 10 found to meet requirements.

  3. Oil and gas delivery to Europe. An Overview of Existing and Planned Infrastructures

    International Nuclear Information System (INIS)

    Nies, S.

    2011-01-01

    The European Union?s hydrocarbon energy supply depends heavily on imports. While the European Commission has recommended diversifying and increasing domestic resources, notably with renewable resources which should grow to 20% by 2020, dependence on hydrocarbon imports will remain not only substantial, but will increase. Particular attention must thus be paid to the question of transportation, and also to the countries of origin, investments in infrastructure, their protection, relations with transit countries, 'competing consumers? (notably China and emerging countries, but also the United States), energy wastefulness in producing countries, and, finally, price. Security of supply depends on adequate and reliable infrastructure, and must always be thought of in the long term. This entirely revised edition of the fourth study conducted by the European Governance and Geopolitics of Energy program at Ifri includes discussions about pipeline routes and potential outputs, their current use and financial requirements for transportation, ongoing projects and those planned for the future, their cost, their financing, and their probable operational start-up date. While all infrastructures are necessarily included (including Norway, the United Kingdom, and North Africa), particular attention is paid to transportation infrastructure that connects Europe with Russia and the former Soviet Union (Central Asia, Caspian Sea). It will be immediately clear that the issue of gas is dominant in current discussions. (author)

  4. Integration of molecular imaging in treatment planning and delivery of modern radiotherapy

    International Nuclear Information System (INIS)

    Jacob, V.; Wilkens, J.J.

    2011-01-01

    Among various imaging modalities currently available, positron emission tomography (PET) has the potential to visualize processes on a molecular level. Molecular imaging, often also referred to as functional or biological imaging, brought a new dimension to diagnostics and therapy of cancer by providing images of metabolism and other processes in the human body and in tumours. PET was first applied for diagnostics and staging of various tumours with high diagnostic precision. Modern radiotherapy asks increasingly for individualized treatment strategies, taking molecular imaging into account. Technical developments over the last years, in particular methods to register various imaging modalities within software packages for treatment planning and target delineation, facilitated the use of PET imaging in radiotherapy. In order to exploit the full potential of modern high-precision radiotherapy, exact imaging procedures are necessary, for example for precise target volume definition. In the long run, concepts employing an inhomogeneous dose prescription based on biological imaging may become routine in clinical applications, leading to individualized, biologically adaptive therapy. (orig.)

  5. Institutional Patient-specific IMRT QA Does Not Predict Unacceptable Plan Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Kry, Stephen F., E-mail: sfkry@mdanderson.org [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Molineu, Andrea [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kerns, James R.; Faught, Austin M.; Huang, Jessie Y.; Pulliam, Kiley B.; Tonigan, Jackie [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, Texas (United States); Alvarez, Paola [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Stingo, Francesco [The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, Texas (United States); Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Followill, David S. [Imaging and Radiation Oncology Core at Houston, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, Texas (United States)

    2014-12-01

    Purpose: To determine whether in-house patient-specific intensity modulated radiation therapy quality assurance (IMRT QA) results predict Imaging and Radiation Oncology Core (IROC)-Houston phantom results. Methods and Materials: IROC Houston's IMRT head and neck phantoms have been irradiated by numerous institutions as part of clinical trial credentialing. We retrospectively compared these phantom results with those of in-house IMRT QA (following the institution's clinical process) for 855 irradiations performed between 2003 and 2013. The sensitivity and specificity of IMRT QA to detect unacceptable or acceptable plans were determined relative to the IROC Houston phantom results. Additional analyses evaluated specific IMRT QA dosimeters and analysis methods. Results: IMRT QA universally showed poor sensitivity relative to the head and neck phantom, that is, poor ability to predict a failing IROC Houston phantom result. Depending on how the IMRT QA results were interpreted, overall sensitivity ranged from 2% to 18%. For different IMRT QA methods, sensitivity ranged from 3% to 54%. Although the observed sensitivity was particularly poor at clinical thresholds (eg 3% dose difference or 90% of pixels passing gamma), receiver operator characteristic analysis indicated that no threshold showed good sensitivity and specificity for the devices evaluated. Conclusions: IMRT QA is not a reasonable replacement for a credentialing phantom. Moreover, the particularly poor agreement between IMRT QA and the IROC Houston phantoms highlights surprising inconsistency in the QA process.

  6. Institutional Patient-specific IMRT QA Does Not Predict Unacceptable Plan Delivery

    International Nuclear Information System (INIS)

    Kry, Stephen F.; Molineu, Andrea; Kerns, James R.; Faught, Austin M.; Huang, Jessie Y.; Pulliam, Kiley B.; Tonigan, Jackie; Alvarez, Paola; Stingo, Francesco; Followill, David S.

    2014-01-01

    Purpose: To determine whether in-house patient-specific intensity modulated radiation therapy quality assurance (IMRT QA) results predict Imaging and Radiation Oncology Core (IROC)-Houston phantom results. Methods and Materials: IROC Houston's IMRT head and neck phantoms have been irradiated by numerous institutions as part of clinical trial credentialing. We retrospectively compared these phantom results with those of in-house IMRT QA (following the institution's clinical process) for 855 irradiations performed between 2003 and 2013. The sensitivity and specificity of IMRT QA to detect unacceptable or acceptable plans were determined relative to the IROC Houston phantom results. Additional analyses evaluated specific IMRT QA dosimeters and analysis methods. Results: IMRT QA universally showed poor sensitivity relative to the head and neck phantom, that is, poor ability to predict a failing IROC Houston phantom result. Depending on how the IMRT QA results were interpreted, overall sensitivity ranged from 2% to 18%. For different IMRT QA methods, sensitivity ranged from 3% to 54%. Although the observed sensitivity was particularly poor at clinical thresholds (eg 3% dose difference or 90% of pixels passing gamma), receiver operator characteristic analysis indicated that no threshold showed good sensitivity and specificity for the devices evaluated. Conclusions: IMRT QA is not a reasonable replacement for a credentialing phantom. Moreover, the particularly poor agreement between IMRT QA and the IROC Houston phantoms highlights surprising inconsistency in the QA process

  7. Oil and gas delivery to Europe. An Overview of Existing and Planned Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Nies, S.

    2011-07-01

    The European Union?s hydrocarbon energy supply depends heavily on imports. While the European Commission has recommended diversifying and increasing domestic resources, notably with renewable resources which should grow to 20% by 2020, dependence on hydrocarbon imports will remain not only substantial, but will increase. Particular attention must thus be paid to the question of transportation, and also to the countries of origin, investments in infrastructure, their protection, relations with transit countries, 'competing consumers? (notably China and emerging countries, but also the United States), energy wastefulness in producing countries, and, finally, price. Security of supply depends on adequate and reliable infrastructure, and must always be thought of in the long term. This entirely revised edition of the fourth study conducted by the European Governance and Geopolitics of Energy program at Ifri includes discussions about pipeline routes and potential outputs, their current use and financial requirements for transportation, ongoing projects and those planned for the future, their cost, their financing, and their probable operational start-up date. While all infrastructures are necessarily included (including Norway, the United Kingdom, and North Africa), particular attention is paid to transportation infrastructure that connects Europe with Russia and the former Soviet Union (Central Asia, Caspian Sea). It will be immediately clear that the issue of gas is dominant in current discussions. (author)

  8. Polyimide Foams Offer Superior Insulation

    Science.gov (United States)

    2012-01-01

    At Langley Research Center, Erik Weiser and his colleagues in the Advanced Materials and Processing Branch were working with a new substance for fabricating composites for use in supersonic aircraft. The team, however, was experiencing some frustration. Every time they tried to create a solid composite from the polyimide (an advanced polymer) material, it bubbled and foamed. It seemed like the team had reached a dead end in their research - until they had another idea. "We said, This isn t going to work for composites, but maybe we could make a foam out of it," Weiser says. "That was kind of our eureka moment, to see if we could go in a whole other direction. And it worked." Weiser and his colleagues invented a new kind of polyimide foam insulation they named TEEK. The innovation displayed a host of advantages over existing insulation options. Compared to other commercial foams, Weiser explains, polyimide foams perform well across a broad range of temperatures, noting that the NASA TEEK foams provide effective structural insulation up to 600 F and down to cryogenic temperatures. The foam does not burn or off-gas toxic fumes, and even at -423 F - the temperature of liquid hydrogen - the material stays flexible. The inventors could produce the TEEK foam at a range of densities, from 0.5 pounds per cubic foot up to 20 pounds per cubic foot, making the foam ideal for a range of applications, including as insulation for reusable launch vehicles and for cryogenic tanks and lines. They also developed a unique, friable balloon format for manufacturing the foam, producing it as hollow microspheres that allowed the foam to be molded and then cured into any desired shape - perfect for insulating pipes of different sizes and configurations. The team s originally unplanned invention won an "R&D 100" award, and a later form of the foam, called LaRC FPF-44 (Spinoff 2009), was named "NASA Invention of the Year" in 2007.

  9. Cryogenic foam insulation: Abstracted publications

    Science.gov (United States)

    Williamson, F. R.

    1977-01-01

    A group of documents were chosen and abstracted which contain information on the properties of foam materials and on the use of foams as thermal insulation at cryogenic temperatures. The properties include thermal properties, mechanical properties, and compatibility properties with oxygen and other cryogenic fluids. Uses of foams include applications as thermal insulation for spacecraft propellant tanks, and for liquefied natural gas storage tanks and pipelines.

  10. Foam injection method and system

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, W C; Parmley, J B; Shepard, J C

    1977-05-10

    A method is described for more efficiently practicing in situ combustion techniques by generating a gas-water mist or foam adjacent to the combustion formation within the injection well. The mist or foam is forced out of the well into the formation to transport heat away from the burned region of the formation toward the periphery of the combustion region to conserve fuel. Also taught are a method and system for fluid treating a formation while maintaining enhanced conformance of the fluid injection profile by generating a mist or foam down-hole adjacent to the formation and then forcing the mist or foam out into the formation. (19 claims)

  11. Polyurethane Foams with Pyrimidine Rings

    Directory of Open Access Journals (Sweden)

    Kania Ewelina

    2014-09-01

    Full Text Available Oligoetherols based on pyrimidine ring were obtained upon reaction of barbituric acid with glycidol and alkylene carbonates. These oligoetherols were then used to obtain polyurethane foams in the reaction of oligoetherols with isocyanates and water. The protocol of foam synthesis was optimized by the choice of proper kind of oligoetherol and synthetic composition. The thermal resistance was studied by dynamic and static methods with concomitant monitoring of compressive strength. The polyurethane foams have similar physical properties as the classic ones except their enhanced thermal resistance. They stand long-time heating even at 200°C. Moreover thermal exposition of foams results generally in increase of their compressive strength.

  12. Bi-liquid foams

    International Nuclear Information System (INIS)

    Sonneville, Odile

    1997-01-01

    Concentrated emulsions have structures similar to foams; for this reason they are also called 'bi-liquid foams'. For oil in water emulsions, they are made of polyhedral oil cells separated by aqueous surfactant films. The limited stability of these Systems is a major nuisance in their applications. In this work, we tried to understand and to control the mechanisms through which bi-liquid foams can loose their stability. In a first stage, we characterized the states of surfactant films in bi-liquid foams submitted to different pressures. We determined their hydration, the surfactant density at interfaces as well as their thicknesses. The bi-liquid foams were made by concentrating hexadecane-in-water emulsions through centrifugation. The initial emulsions contained submicron oil droplets that were completely covered with surfactant. We measured the resistance of the films to dehydration, and we represented it by pressure-film thickness curves or pressure-film hydration curves. We also obtained evidence that the interfacial surfactant density increases when the film thickness is decreased (SDS case). The Newton Black Film state is the most dehydrated metastable state that can be reached. In this state, the films can be described as surfactant bilayers that only contain the hydration water of the surfactant polar heads. Two different processes are involved the destabilization of bi-liquid foams: Ostwald ripening (oil transfer from small cells to large cells) and coalescence (films rupture). The first mechanism can be controlled by choosing oils that are very insoluble in water, avoiding ethoxylated nonionic surfactants of low molecular weight, and making emulsions that are not too fine. The second mechanism is responsible for the catastrophic destabilization of bi-liquid foams made of droplets above one micron or with a low coverage in surfactant. In these cases, destabilization occurs in the early stages of concentration, when the films are still thick. It is caused

  13. Serious adverse neonatal outcomes such as 5-minute Apgar score of zero and seizures or severe neurologic dysfunction are increased in planned home births after cesarean delivery.

    Science.gov (United States)

    Grünebaum, Amos; McCullough, Laurence B; Arabin, Birgit; Chervenak, Frank A

    2017-01-01

    The United States is with 37,451 home births in 2014 the country with the largest absolute number of home births among all developed countries. The purpose of this study was to examine the occurrence and risks of a 5-minute Apgar score of zero and neonatal seizures or serious neurologic dysfunction in women with a history of prior cesarean delivery for planned home vaginal birth after cesarean (VBAC), compared to hospital VBAC and hospital birth cesarean deliveries for term normal weight infants in the United States from 2007-2014. We report in this study outcomes of women who had one or more prior cesarean deliveries and included women who had a successful vaginal birth after a trial of labor after cesarean (TOLAC) at home and in the hospital, and a repeat cesarean delivery in the hospital. We excluded preterm births (home birth VBAC had an approximately 10-fold and higher increase in adverse neonatal outcomes when compared to hospital VBACS and hospital repeat cesarean deliveries, a significantly higher incidence and risk of a 5-minute Apgar score of 0 of 1 in 890 (11.24/10,000, relative risk 9.04, 95% confidence interval 4-20.39, phome TOLACs and for those desiring a VBAC should strongly recommend a planned TOLAC in the appropriate hospital setting. We emphasize that this stance should be accompanied by effective efforts to make TOLAC available in the appropriate hospital setting.

  14. THIRD-GENERATION FOAM BLOWING AGENTS FOR FOAM INSULATION

    Science.gov (United States)

    The report gives results of a study of third-generation blowing agents for foam insulation. (NOTE: the search for third-generation foam blowing agents has led to the realization that, as the number of potential substitutes increases, new concerns, such as their potential to act a...

  15. A fully electronic intensity-modulated radiation therapy quality assurance (IMRT QA) process implemented in a network comprised of independent treatment planning, record and verify, and delivery systems

    International Nuclear Information System (INIS)

    Bailey, Daniel W; Kumaraswamy, Lalith; Podgorsak, Matthew B

    2010-01-01

    The purpose of this study is to implement an electronic method to perform and analyze intensity-modulated radiation therapy quality assurance (IMRT QA) using an aSi megavoltage electronic portal imaging device in a network comprised of independent treatment planning, record and verify (R&V), and delivery systems. A verification plan was generated in the treatment planning system using the actual treatment plan of a patient. After exporting the treatment fields to the R&V system, the fields were delivered in QA mode with the aSi imager deployed. The resulting dosimetric images are automatically stored in a DICOM-RT format in the delivery system treatment console computer. The relative dose density images are subsequently pushed to the R&V system. The absolute dose images are then transferred electronically from the treatment console computer to the treatment planning system and imported into the verification plan in the dosimetry work space for further analysis. Screen shots of the gamma evaluation and isodose comparison are imported into the R&V system as an electronic file (e.g. PDF) to be reviewed prior to initiation of patient treatment. A relative dose image predicted by the treatment planning system can also be sent to the R&V system to be compared with the relative dose density image measured with the aSi imager. Our department does not have integrated planning, R&V, and delivery systems. In spite of this, we are able to fully implement a paperless and filmless IMRT QA process, allowing subsequent analysis and approval to be more efficient, while the QA document is directly attached to its specific patient chart in the R&V system in electronic form. The calculated and measured relative dose images can be compared electronically within the R&V system to analyze the density differences and ensure proper dose delivery to patients. In the absence of an integrated planning, verifying, and delivery system, we have shown that it is nevertheless possible to develop a

  16. Mass transfer measurements in foams

    International Nuclear Information System (INIS)

    Leblond, J.G.; Fournel, B.

    2004-01-01

    Full text of publication follows:This study participates to the elaboration of a method for decontamination of the inside surfaces of steel structures (pipes, tanks,...). The solution which has been chosen is to attack the surface of the structure by a dipping solution. In order to reduce the quantity of product to be recovered and treated at the end of the cleaning process, the active solution will be introduced as a foam. During its free or forced drainage the foam supplies an active liquid film along the structure surfaces. It was important to know if the transfers of the dipping liquid inside the foam and between foam and wall film are sufficient to allow a correct supplying of the active liquid at the wall and a correct dragging of the dipped products. The objective of this work is to develop a numerical model which simulates the various transfers. However such a modeling cannot be performed without a thorough knowledge of the different transfer parameters in the foam and in the film. The following study has been performed on a model foam (foaming water + air) held in a smooth vertical glass pipe and submitted to a forced drainage by the foaming water (water + surfactants). The liquid transfer involves the dispersion of the drainage liquid inside the foam and the transfer between the foam and the liquid film flowing down at the wall. The different transfers has been analyzed by NMR using a PFGSE-NMR sequence, which allows to determine the propagator, i.e., the probability density of the liquid particle displacements during a given time interval Δt, along a selected direction. This study allowed to measure, firstly, the mean liquid and the liquid dispersion in the foam along the vertical and horizontal direction, and secondly, the vertical mean velocity in the parietal liquid film. (authors)

  17. The effectiveness of birth plans in increasing use of skilled care at delivery and postnatal care in rural Tanzania: a cluster randomised trial.

    Science.gov (United States)

    Magoma, Moke; Requejo, Jennifer; Campbell, Oona; Cousens, Simon; Merialdi, Mario; Filippi, Veronique

    2013-04-01

    To determine the effectiveness of birth plans in increasing use of skilled care at delivery and in the postnatal period among antenatal care (ANC) attendees in a rural district with low occupancy of health units for delivery but high antenatal care uptake in northern Tanzania. Cluster randomised trial in Ngorongoro district, Arusha region, involving 16 health units (8 per arm). Nine hundred and five pregnant women at 24 weeks of gestation and above (404 in the intervention arm) were recruited and followed up to at least 1 month postpartum. Skilled delivery care uptake was 16.8% higher in the intervention units than in the control [95% CI 2.6-31.0; P = 0.02]. Postnatal care utilisation in the first month of delivery was higher (difference in proportions: 30.0% [95% CI 1.3-47.7; P < 0.01]) and also initiated earlier (mean duration 6.6 ± 1.7 days vs. 20.9 ± 4.4 days, P < 0.01) in the intervention than in the control arm. Women's and providers' reports of care satisfaction (received or provided) did not differ greatly between the two arms of the study (difference in proportion: 12.1% [95% CI -6.3-30.5] P = 0.17 and 6.9% [95% CI -3.2-17.1] P = 0.15, respectively). Implementation of birth plans during ANC can increase the uptake of skilled delivery and post delivery care in the study district without negatively affecting women's and providers' satisfaction with available ANC services. Birth plans should be considered along with the range of other recommended interventions as a strategy to improve the uptake of maternal health services. © 2013 Blackwell Publishing Ltd.

  18. The role of Cobalt-60 source in Intensity Modulated Radiation Therapy: From modeling finite sources to treatment planning and conformal dose delivery

    Science.gov (United States)

    Dhanesar, Sandeep Kaur

    Cobalt-60 (Co-60) units played an integral role in radiation therapy from the mid-1950s to the 1970s. Although they continue to be used to treat cancer in some parts of the world, their role has been significantly reduced due to the invention of medical linear accelerators. A number of groups have indicated a strong potential for Co-60 units in modern radiation therapy. The Medical Physics group at the Cancer Center of the Southeastern Ontario and Queen's University has shown the feasibility of Intensity Modulated Radiation Therapy (IMRT) via simple conformal treatment planning and dose delivery using a Co-60 unit. In this thesis, initial Co-60 tomotherapy planning investigations on simple uniform phantoms are extended to actual clinical cases based on patient CT data. The planning is based on radiation dose data from a clinical Co-60 unit fitted with a multileaf collimator (MLC) and modeled in the EGSnrc Monte Carlo system. An in house treatment planning program is used to calculate IMRT dose distributions. Conformal delivery in a single slice on a uniform phantom based on sequentially delivered pencil beams is verified by Gafchromic film. Volumetric dose distributions for Co-60 serial tomotherapy are then generated for typical clinical sites that had been treated at our clinic by conventional 6MV IMRT using Varian Eclipse treatment plans. The Co-60 treatment plans are compared with the clinical IMRT plans using conventional matrices such as dose volume histograms (DVH). Dose delivery based on simultaneously opened MLC leaves is also explored and a novel MLC segmentation method is proposed. In order to increase efficiency of dose calculations, a novel convolution based fluence model for treatment planning is also proposed. The ion chamber measurements showed that the Monte Carlo modeling of the beam data under the MIMiC MLC is accurate. The film measurements from the uniform phantom irradiations confirm that IMRT plans from our in-house treatment planning system

  19. FoamVis, A Visualization System for Foam Research: Design and Implementation

    OpenAIRE

    Lipsa, Dan; Roberts, Richard; Laramee, Robert

    2015-01-01

    Liquid foams are used in areas such as mineral separation, oil recovery, food and beverage production, sanitation and fire fighting. To improve the quality of products and the efficiency of processes in these areas, foam scientists wish to understand and control foam behaviour. To this end, foam scientists have used foam simulations to model foam behaviour; however, analysing these simulations presents difficult challenges. We describe the main foam research challenges and present the design ...

  20. Serious adverse neonatal outcomes such as 5-minute Apgar score of zero and seizures or severe neurologic dysfunction are increased in planned home births after cesarean delivery

    OpenAIRE

    Gr?nebaum, Amos; McCullough, Laurence B.; Arabin, Birgit; Chervenak, Frank A.

    2017-01-01

    The United States is with 37,451 home births in 2014 the country with the largest absolute number of home births among all developed countries. The purpose of this study was to examine the occurrence and risks of a 5-minute Apgar score of zero and neonatal seizures or serious neurologic dysfunction in women with a history of prior cesarean delivery for planned home vaginal birth after cesarean (VBAC), compared to hospital VBAC and hospital birth cesarean deliveries for term normal weight infa...

  1. Serious adverse neonatal outcomes such as 5-minute Apgar score of zero and seizures or severe neurologic dysfunction are increased in planned home births after cesarean delivery.

    Directory of Open Access Journals (Sweden)

    Amos Grünebaum

    Full Text Available The United States is with 37,451 home births in 2014 the country with the largest absolute number of home births among all developed countries. The purpose of this study was to examine the occurrence and risks of a 5-minute Apgar score of zero and neonatal seizures or serious neurologic dysfunction in women with a history of prior cesarean delivery for planned home vaginal birth after cesarean (VBAC, compared to hospital VBAC and hospital birth cesarean deliveries for term normal weight infants in the United States from 2007-2014. We report in this study outcomes of women who had one or more prior cesarean deliveries and included women who had a successful vaginal birth after a trial of labor after cesarean (TOLAC at home and in the hospital, and a repeat cesarean delivery in the hospital. We excluded preterm births (<37 weeks and infants weighing under 2500 g. Hospital VBACS were the reference. Women with a planned home birth VBAC had an approximately 10-fold and higher increase in adverse neonatal outcomes when compared to hospital VBACS and hospital repeat cesarean deliveries, a significantly higher incidence and risk of a 5-minute Apgar score of 0 of 1 in 890 (11.24/10,000, relative risk 9.04, 95% confidence interval 4-20.39, p<.0001 and an incidence of neonatal seizures or severe neurologic dysfunction of 1 in 814 (Incidence: 12.27/10,000, relative risk 11.19, 95% confidence interval 5.13-24.29, p<.0001. Because of the significantly increased neonatal risks, obstetric providers should therefore not offer or perform planned home TOLACs and for those desiring a VBAC should strongly recommend a planned TOLAC in the appropriate hospital setting. We emphasize that this stance should be accompanied by effective efforts to make TOLAC available in the appropriate hospital setting.

  2. Novel developments in foam sclerotherapy: Focus on Varithena® (polidocanol endovenous microfoam) in the management of varicose veins.

    Science.gov (United States)

    Star, Phoebe; Connor, David E; Parsi, Kurosh

    2018-04-01

    Scope Varithena® is a recently approved commercially available drug/delivery unit that produces foam using 1% polidocanol for the management of varicose veins. The purpose of this review is to examine the benefits of foam sclerotherapy, features of the ideal foam sclerosant and the strengths and limitations of Varithena® in the context of current foam sclerotherapy practices. Method Electronic databases including PubMed, Medline (Ovid) SP as well as trial registries and product information sheets were searched using the keywords, 'Varithena', 'Varisolve', 'polidocanol endovenous microfoam', 'polidocanol' and/or 'foam sclerotherapy/sclerosant'. Articles published prior to 20 September 2016 were identified. Results Foam sclerosants have effectively replaced liquid agents due to their physiochemical properties resulting in better clinical outcomes. Medical practitioners commonly prepare sclerosant foam at the bedside by agitating liquid sclerosant with a gas such as room air, using techniques as described by Tessari or the double syringe method. Such physician-compounded foams are highly operator dependent producing inconsistent foams of different gas/liquid compositions, bubble size, foam behaviour and varied safety profiles. Varithena® overcomes the variability and inconsistencies of physician-compounded foam. However, Varithena® has limited applications due to its fixed sclerosant type and concentration, cost and lack of worldwide availability. Clinical trials of Varithena® have demonstrated efficacy and safety outcomes equivalent or better than physician-compounded foam but only in comparison to placebo alone. Conclusion Varithena® is a promising step towards the creation of an ideal sclerosant foam. Further assessment in independent randomised controlled clinical trials is required to establish the advantages of Varithena® over and above the current best practice physician-compounded foam.

  3. Developing resources to facilitate culturally-sensitive service planning and delivery - doing research inclusively with people with learning disabilities.

    Science.gov (United States)

    Unwin, Gemma; Larkin, Michael; Rose, John; Kroese, Biza Stenfert; Malcolm, Stephen

    2016-01-01

    (Please see www.Toolsfortalking.co.uk for an easy read summary of the project.) The Tools for Talking are a set of resources that were developed through collaboration between Black, Asian and minority ethnic people with learning disabilities and researchers at the University of Birmingham. The resources were designed to be used by people with learning disabilities and service providers to facilitate culturally-sensitive communication and information sharing, service planning and delivery. They comprise illustrative videos and exploratory activities relating to five topics, namely, culture, activities, support from staff, important people, choices and independence. These topics emerged as important to people with learning disabilities during the 'Access to Social Care-Learning Disabilities' (ASC-LD) study which involved interviews with 32 adults with learning disabilities from Black, Asian and minority ethnic communities. The results of the ASC-LD study were used to develop a set of draft resources which were then co-developed through collaboration with people with learning disabilities and service providers. A 'Partnership event' was convened to involve stakeholders in the development of the resources. This paper describes the refinement of these materials by people with learning disabilities from Black, Asian and minority ethnic backgrounds in cooperation with a range of other stakeholders. Background Black, Asian and minority ethnic people with learning disabilities face inequities in health and social care provision. Lower levels of service uptake and satisfaction with services have been reported, however, this is largely based on the views of carers. The 'Access to Social Care: Learning Disabilities (ASC-LD)' study sought to explore the views and experiences of social support services among adults with learning disabilities from Black, Asian and minority ethnic communities. Interviews with 32 Black, Asian and minority ethnic adults with learning disabilities

  4. Foam rheology at large deformation

    Science.gov (United States)

    Géminard, J.-C.; Pastenes, J. C.; Melo, F.

    2018-04-01

    Large deformations are prone to cause irreversible changes in materials structure, generally leading to either material hardening or softening. Aqueous foam is a metastable disordered structure of densely packed gas bubbles. We report on the mechanical response of a foam layer subjected to quasistatic periodic shear at large amplitude. We observe that, upon increasing shear, the shear stress follows a universal curve that is nearly exponential and tends to an asymptotic stress value interpreted as the critical yield stress at which the foam structure is completely remodeled. Relevant trends of the foam mechanical response to cycling are mathematically reproduced through a simple law accounting for the amount of plastic deformation upon increasing stress. This view provides a natural interpretation to stress hardening in foams, demonstrating that plastic effects are present in this material even for minute deformation.

  5. SU-E-T-110: An Investigation On Monitor Unit Threshold and Effects On IMPT Delivery in Proton Pencil Beam Planning System

    International Nuclear Information System (INIS)

    Syh, J; Ding, X; Syh, J; Patel, B; Rosen, L; Wu, H

    2015-01-01

    Purpose: An approved proton pencil beam scanning (PBS) treatment plan might not be able to deliver because of existed extremely low monitor unit per beam spot. A dual hybrid plan with higher efficiency of higher spot monitor unit and the efficacy of less number of energy layers were searched and optimized. The range of monitor unit threshold setting was investigated and the plan quality was evaluated by target dose conformity. Methods: Certain limitations and requirements need to be checks and tested before a nominal proton PBS treatment plan can be delivered. The plan needs to be met the machine characterization, specification in record and verification to deliver the beams. Minimal threshold of monitor unit, e.g. 0.02, per spot was set to filter the low counts and plan was re-computed. Further MU threshold increment was tested in sequence without sacrificing the plan quality. The number of energy layer was also alternated due to elimination of low count layer(s). Results: Minimal MU/spot threshold, spot spacing in each energy layer and total number of energy layer and the MU weighting of beam spots of each beam were evaluated. Plan optimization between increases of the spot MU (efficiency) and less energy layers of delivery (efficacy) was adjusted. 5% weighting limit of total monitor unit per beam was feasible. Scarce spreading of beam spots was not discouraging as long as target dose conformity within 3% criteria. Conclusion: Each spot size is equivalent to the relative dose in the beam delivery system. The energy layer is associated with the depth of the targeting tumor. Our work is crucial to maintain the best possible quality plan. To keep integrity of all intrinsic elements such as spot size, spot number, layer number and the carried weighting of spots in each layer is important in this study

  6. Multi-institutional comparison of simulated treatment delivery errors in ssIMRT, manually planned VMAT and autoplan-VMAT plans for nasopharyngeal radiotherapy

    DEFF Research Database (Denmark)

    Pogson, Elise M; Aruguman, Sankar; Hansen, Christian R

    2017-01-01

    PURPOSE: To quantify the impact of simulated errors for nasopharynx radiotherapy across multiple institutions and planning techniques (auto-plan generated Volumetric Modulated Arc Therapy (ap-VMAT), manually planned VMAT (mp-VMAT) and manually planned step and shoot Intensity Modulated Radiation...... Therapy (mp-ssIMRT)). METHODS: Ten patients were retrospectively planned with VMAT according to three institution's protocols. Within one institution two further treatment plans were generated using differing treatment planning techniques. This resulted in mp-ssIMRT, mp-VMAT, and ap-VMAT plans. Introduced...

  7. Closed-cell polymeric foam for hydrogen separation and storage

    Czech Academy of Sciences Publication Activity Database

    Pientka, Zbyněk; Pokorný, P.; Bélafi-Bakó, K.

    2007-01-01

    Roč. 304, 1-2 (2007), s. 82-87 ISSN 0376-7388 R&D Projects: GA ČR GA203/06/1207 Institutional research plan: CEZ:AV0Z40500505 Keywords : polymeric foam * gas separation * hydrogen storage Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.432, year: 2007

  8. A pulsed mode electrolytic drug delivery device

    International Nuclear Information System (INIS)

    Yi, Ying; Foulds, Ian G; Buttner, Ulrich; Carreno, Armando A A; Conchouso, David

    2015-01-01

    This paper reports the design of a proof-of-concept drug delivery device that is actuated using the bubbles formed during electrolysis. The device uses a platinum (Pt) coated nickel (Ni) metal foam and a solid drug in reservoir (SDR) approach to improve the device’s performance. This electrochemically-driven pump has many features that are unlike conventional drug delivery devices: it is capable of pumping periodically and being refilled automatically; it features drug release control; and it enables targeted delivery. Pt-coated metal foam is used as a catalytic reforming element, which reduces the period of each delivery cycle. Two methods were used for fabricating the Pt-coated metal: sputtering and electroplating. Of these two methods, the sputtered Pt-coated metal foam has a higher pumping rate; it also has a comparable recombination rate when compared to the electroplated Pt-coated metal foam. The only drawback of this catalytic reformer is that it consumes nickel scaffold. Considering long-term applications, the electroplated Pt metal foam was selected for drug delivery, where a controlled drug release rate of 2.2 μg  ±  0.3 μg per actuation pulse was achieved using 4 mW of power. (paper)

  9. A pulsed mode electrolytic drug delivery device

    KAUST Repository

    Yi, Ying

    2015-09-14

    This paper reports the design of a proof-of-concept drug delivery device that is actuated using the bubbles formed during electrolysis. The device uses a platinum (Pt) coated nickel (Ni) metal foam and a solid drug in reservoir (SDR) approach to improve the device\\'s performance. This electrochemically-driven pump has many features that are unlike conventional drug delivery devices: it is capable of pumping periodically and being refilled automatically; it features drug release control; and it enables targeted delivery. Pt-coated metal foam is used as a catalytic reforming element, which reduces the period of each delivery cycle. Two methods were used for fabricating the Pt-coated metal: sputtering and electroplating. Of these two methods, the sputtered Pt-coated metal foam has a higher pumping rate; it also has a comparable recombination rate when compared to the electroplated Pt-coated metal foam. The only drawback of this catalytic reformer is that it consumes nickel scaffold. Considering long-term applications, the electroplated Pt metal foam was selected for drug delivery, where a controlled drug release rate of 2.2 μg ± 0.3 μg per actuation pulse was achieved using 4 mW of power.

  10. Poster - Thur Eve - 50: Planning and delivery accuracy of stereotactic radiosurgery with Tomotherapy as compared to linear-accelerator and robotic based radiosurgery.

    Science.gov (United States)

    Thakur, V; Soisson, E; Ruo, R; Doucet, R; Parker, W; Seuntjens, J

    2012-07-01

    This study includes planning and delivery comparison of three stereotactic radiosurgery techniques : Helical Tomotherapy (HT), circular collimator-based Linear-accelerator and robotic-radiosurgery. Plans were generated for two spherical targets of diameter 6 mm and 10 mm contoured at the center of a Lucite phantom, using similar planning constrains. Planning comparison showed that average conformality (0-1best) for Linear-accelerator, robotic-radiosurgery and HT was 1.43, 1.24, and 1.77 and gradient index (less is better) was 2.72, 4.50 and 13.56 respectively. For delivery comparison, plans were delivered to radiochromic film and measured dose was compared with the planned dose. For Linear-accelerator and robotic-radiosurgery more than 99% pixels-passing a gamma criteria of 3% dose difference and 1 mm distance to agreement where as for HT this value was as low as 40% for off-axis targets. Further investigation of the delivery accuracy as a function of the location of the target with in the bore was initiated using small volume A1SL (0.057 cm 3 ) and MicroLion liquid ion chamber (0.0017 cm 3 ). Point dose measurements for targets located at the center and 10 cm away from the center of the bore showed that delivered dose varied by more than 15% for targets placed away from the center of the bore as opposed to at the center. In conclusion, Linear-accelerator and the robotic-radiosurgery techniques showed preferable gradient and conformality. For HT, point dose measurements were significantly lower than predicted by the TPS when the target was positioned away from the isocenter, while they were found to be higher at isocenter. © 2012 American Association of Physicists in Medicine.

  11. Mechanical Characterization of Rigid Polyurethane Foams

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei-Yang [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Mechanics of Materials

    2014-12-01

    Foam materials are used to protect sensitive components from impact loading. In order to predict and simulate the foam performance under various loading conditions, a validated foam model is needed and the mechanical properties of foams need to be characterized. Uniaxial compression and tension tests were conducted for different densities of foams under various temperatures and loading rates. Crush stress, tensile strength, and elastic modulus were obtained. A newly developed confined compression experiment provided data for investigating the foam flow direction. A biaxial tension experiment was also developed to explore the damage surface of a rigid polyurethane foam.

  12. Timing of planned repeat cesarean delivery after two or more previous cesarean sections--risk for unplanned cesarean delivery and pregnancy outcome.

    Science.gov (United States)

    Melamed, Nir; Hadar, Eran; Keidar, Liron; Peled, Yoav; Wiznitzer, Arnon; Yogev, Yariv

    2014-03-01

    objective: To assess the effect of the scheduled gestational age for a repeat planned cesarean section (CS) on the risk for adverse pregnancy outcome in women with two or more previous CS. A retrospective cohort study of all women after ≥2 previous CS who were scheduled for a repeat planned CS. Women were divided into two groups at which the planned CS was scheduled: 38-week group or 39-week group. Overall, 377 were enrolled, 264 (70.0%) and 113 (30.0%) in the 38-week and the 39-week groups, respectively. The rate of an unplanned CS was significantly higher in the 39-week versus the 38-week group (23.0% versus 13.3%, p = 0.02). A repeat planned CS scheduled to week 39 was associated with an increased risk of maternal adverse outcome (31.9% versus 21.6%, p = 0.03). There was no significant difference in the rate of adverse neonatal outcome between the two groups (20.8% versus 23.0%, p = 0.5). The lowest rate of any adverse outcome (maternal and/or neonatal) was observed when CS was scheduled to 38 + 1 weeks of gestation. In women after two cesarean sections, scheduling a planned CS at around 39 weeks compared with at around 38 weeks is associated with an increased risk for maternal adverse outcome with no apparent advantage in terms of neonatal outcome.

  13. PUR-PIR foam produced based on poly(hydroxybutyl citrate foamed founded with different factories

    Directory of Open Access Journals (Sweden)

    Liszkowska Joanna

    2018-03-01

    Full Text Available A poly(hydroxybutyl citrate p(HBC was obtained. The product compound produced in the solution during esterification, was added to rigid polyurethane-polyisocyanurate foams (PUR-PIR. The amount of petrochemical polyol in the foams was decreased in favor of the p(HBC from 0.1 to 0.5 equivalent. The foams were foamed in two ways: with distilled water (W foams and with Solkane 365/227 (S foams. The examination results of both foam series were compared. They showed that the foams foamed with water have higher softening temperature than the foams foamed with solkane. The retention values for both foam series are around 91–95%, and water absorption in the range of 0.7–3.2%. The anisotropy coefficient did not exceed 1.08 (the lowest value being 1.01.

  14. Composite carbon foam electrode

    Science.gov (United States)

    Mayer, Steven T.; Pekala, Richard W.; Kaschmitter, James L.

    1997-01-01

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivty and power to system energy.

  15. Amorphous microcellular polytetrafluoroethylene foam film

    Science.gov (United States)

    Tang, Chongzheng

    1991-11-01

    We report herein the preparation of novel low-density ultramicrocellular fluorocarbon foams and their application. These fluorocarbon foams are of interest for the biochemistry arena in numerous applications including foodstuff, pharmacy, wine making, beer brewery, fermentation medical laboratory, and other processing factories. All of those require good quality processing programs in which, after eliminating bacterium and virus, compressed air is needed. Ordinarily, compressed air contains bacterium and virus, its size is 0.01 - 2 micrometers fluorocarbon foam films. Having average porous diameter 0.04 - 0.1 micrometers , these are stable to high temperature (280 degree(s)C) and chemical environments, and generally have good engineering and mechanical properties (e.g., low coefficient of thermal expansion, high modulus, and good dimensional stability). Our new process for preparing low density fluorocarbon foams provides materials with unique properties. As such, they offer the possibility for being superior to earlier materials for a number of the filter applications mentioned.

  16. Microcellular foams via phase separation

    International Nuclear Information System (INIS)

    Young, A.T.

    1985-01-01

    A study of wide variety of processes for making plastic foams shows that phase separation processes for polymers from solutions offers the most viable methods for obtaining rigid plastic foams which met the physical requirements for fusion target designs. Four general phase separation methods have been shown to give polymer foams with densities less than 0.1 g/cm 3 and cell sizes of 30μm or less. These methods involve the utilization of non-solvent, chemical or thermal cooling processes to achieve a controlled phase separation wherein either two distinct phases are obtained where the polymer phase is a continuous phase or two bicontinuous phases are obtained where both the polymer and solvent are interpenetrating, continuous, labyrinthine phases. Subsequent removal of the solvent gives the final foam structure

  17. Fluoride Rinses, Gels and Foams

    DEFF Research Database (Denmark)

    Twetman, Svante; Keller, Mette K

    2016-01-01

    AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after...... (6 on fluoride mouth rinse, 10 on fluoride gel and 3 on fluoride foam); 6 had a low risk of bias while 2 had a moderate risk. All fluoride measures appeared to be beneficial in preventing crown caries and reversing root caries, but the quality of evidence was graded as low for fluoride mouth rinse......, moderate for fluoride gel and very low for acidulated fluoride foam. No conclusions could be drawn on the cost-effectiveness. CONCLUSIONS: This review, covering the recent decade, has further substantiated the evidence for a caries-preventive effect of fluoride mouth rinse, fluoride gel and foam...

  18. Foaming in manure based digesters

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Boe, Kanokwan; Angelidaki, Irini

    2012-01-01

    Anaerobic digestion foaming is one of the major problems that occasionally occurred in the Danish full-scale biogas plants, affecting negatively the overall digestion process. The foam is typically formatted in the main biogas reactor or in the pre-storage tank and the entrapped solids in the foam...... cause severe operational problems, such as blockage of mixing devices, and collapse of pumps. Furthermore, the foaming problem is linked with economic consequences for biogas plants, due to income losses derived from the reduced biogas production, extra labour work and additional maintenance costs...... was increased by the addition of glucose in the feeding substrate. During the 2nd and 4th period the organic loading rate was maintained constant, but instead of glucose, higher concentration of Na-oleate or gelatine was added in the feeding substrate. The results obtained from the above experiment showed...

  19. Photoactivity of Titanium Dioxide Foams

    Directory of Open Access Journals (Sweden)

    Maryam Jami

    2018-01-01

    Full Text Available TiO2 foams have been prepared by a simple mechanical stirring method. Short-chain amphiphilic molecules have been used to stabilize colloidal suspensions of TiO2 nanoparticles. TiO2 foams were characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, UV-vis absorption spectroscopy, and scanning electron microscopy (SEM. The photoassisted oxidation of NO in the gas phase according to ISO 22197-1 has been used to compare the photoactivity of the newly prepared TiO2 foams to that of the original powders. The results showed that the photoactivity is increased up to about 135%. Foam structures seem to be a good means of improving the photoactivity of semiconductor materials and can readily be used for applications such as air purification devices.

  20. Supercapacitors based on carbon foams

    Science.gov (United States)

    Kaschmitter, James L.; Mayer, Steven T.; Pekala, Richard W.

    1993-01-01

    A high energy density capacitor incorporating a variety of carbon foam electrodes is described. The foams, derived from the pyrolysis of resorcinol-formaldehyde and related polymers, are high density (0.1 g/cc-1.0 g/cc) electrically conductive and have high surface areas (400 m.sup.2 /g-1000 m.sup.2 /g). Capacitances on the order of several tens of farad per gram of electrode are achieved.

  1. A cement based syntactic foam

    International Nuclear Information System (INIS)

    Li Guoqiang; Muthyala, Venkata D.

    2008-01-01

    In this study, a cement based syntactic foam core was proposed and experimentally investigated for composite sandwich structures. This was a multi-phase composite material with microballoon dispersed in a rubber latex toughened cement paste matrix. A trace amount of microfiber was also incorporated to increase the number of mechanisms for energy absorption and a small amount of nanoclay was added to improve the crystal structure of the hydrates. Three groups of cement based syntactic foams with varying cement content were investigated. A fourth group of specimens containing pure cement paste were also prepared as control. Each group contained 24 beam specimens. The total number of beam specimens was 96. The dimension of each beam was 30.5 cm x 5.1 cm x 1.5 cm. Twelve foam specimens from each group were wrapped with plain woven 7715 style glass fabric reinforced epoxy to prepare sandwich beams. Twelve cubic foam specimens, three from each group, with a side length of 5.1 cm, were also prepared. Three types of testing, low velocity impact test and four-point bending test on the beam specimens and compression test on the cubic specimens, were conducted to evaluate the impact energy dissipation, stress-strain behavior, and residual strength. Scanning electron microscope (SEM) was also used to examine the energy dissipation mechanisms in the micro-length scale. It was found that the cement based syntactic foam has a higher capacity for dissipating impact energy with an insignificant reduction in strength as compared to the control cement paste core. When compared to a polymer based foam core having similar compositions, it was found that the cement based foam has a comparable energy dissipation capacity. The developed cement based syntactic foam would be a viable alternative for core materials in impact-tolerant composite sandwich structures

  2. Foam shell project: Progress report

    International Nuclear Information System (INIS)

    Overturf, G.; Reibold, B.; Cook, B.; Schroen-Carey, D.

    1994-01-01

    The authors report on their work to produce a foam shell target for two possible applications: (1) as liquid-layered cryogenic target on Omega Upgrade, and (2) as a back-up design for the NIF. This target consists of a roughly 1 mm diameter and 100 μm thick spherical low-density foam shell surrounding a central void. The foam will be slightly overfilled with liquid D 2 or DT, the overfilled excess being symmetrically distributed on the inside of the shell and supported by thermal gradient techniques. The outside of the foam is overcoated with full density polymer which must be topologically smooth. The technology for manufacturing this style of foam shell involves microencapsulation techniques and has been developed by the Japanese at ILE. Their goal is to determine whether this technology can be successfully adapted to meet US ICF objectives. To this end a program of foam shell development has been initiated at LLNL in collaboration with both the General Atomics DOE Target Fabrication Contract Corporation and the Target Fabrication Group at LLE

  3. Stability of metallic foams studied under microgravity

    CERN Document Server

    Wuebben, T; Banhart, J; Odenbach, S

    2003-01-01

    Metal foams are prepared by mixing a metal powder and a gas-releasing blowing agent, by densifying the mix to a dense precursor and finally foaming by melting the powder compact. The foaming process of aluminium foams is monitored in situ by x-ray radioscopy. One observes that foam evolution is accompanied by film rupture processes which lead to foam coalescence. In order to elucidate the importance of oxides for foam stability, lead foams were manufactured from lead powders having two different oxide contents. The two foam types were generated on Earth and under weightlessness during parabolic flights. The measurements show that the main function of oxide particles is to prevent coalescence, while their influence on bulk viscosity of the melt is of secondary importance.

  4. Study of two-phase foam flow

    Energy Technology Data Exchange (ETDEWEB)

    Gurbanov, R S; Guliev, B B; Mekhtiev, K G; Kerimov, R G

    1970-01-01

    The objectives of this study were to determine characteristics of aqueous foam flow through porous media and to estimate the depth of foam penetration into a formation. Foam was generated by mixing air and 1% solution of surfactant PO-1. Foam density was maintained at 0.14 g/cc in all experiments. The foam was passed through sand columns (800 mm long x 30 mm diam) of permeabilities 26, 39, 80, 111, and 133 darcys. Flow rates were measured at various pressure drops and the relationship between system parameters was expressed analytically and graphically. From the data, distance of foam penetration into a formation as a function of pressure drop and permeability was calculated. The data indicate that under most conditions, foam will penetrate the formation to a negligible distance. This study indicates that when foam is used to remove sand from a well, a negligible loss of foam to the formation occurs.

  5. A review of aqueous foam in microscale.

    Science.gov (United States)

    Anazadehsayed, Abdolhamid; Rezaee, Nastaran; Naser, Jamal; Nguyen, Anh V

    2018-06-01

    In recent years, significant progress has been achieved in the study of aqueous foams. Having said this, a better understanding of foam physics requires a deeper and profound study of foam elements. This paper reviews the studies in the microscale of aqueous foams. The elements of aqueous foams are interior Plateau borders, exterior Plateau borders, nodes, and films. Furthermore, these elements' contribution to the drainage of foam and hydraulic resistance are studied. The Marangoni phenomena that can happen in aqueous foams are listed as Marangoni recirculation in the transition region, Marangoni-driven flow from Plateau border towards the film in the foam fractionation process, and Marangoni flow caused by exposure of foam containing photosurfactants under UV. Then, the flow analysis of combined elements of foam such as PB-film along with Marangoni flow and PB-node are studied. Next, we contrast the behavior of foams in different conditions. These various conditions can be perturbation in the foam structure caused by injected water droplets or waves or using a non-Newtonian fluid to make the foam. Further review is about the effect of oil droplets and particles on the characteristics of foam such as drainage, stability and interfacial mobility. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Development of drilling foams for geothermal applications

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, W.J.; Remont, L.J.; Rehm, W.A.; Chenevert, M.E.

    1980-01-01

    The use of foam drilling fluids in geothermal applications is addressed. A description of foams - what they are, how they are used, their properties, equipment required to use them, the advantages and disadvantages of foams, etc. - is presented. Geothermal applications are discussed. Results of industry interviews presented indicate significant potential for foams, but also indicate significant technical problems to be solved to achieve this potential. Testing procedures and results of tests on representative foams provide a basis for work to develop high-temperature foams.

  7. Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

    International Nuclear Information System (INIS)

    Rapp, F.; Schneider, A.; Elsner, P.

    2014-01-01

    Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO 2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength)

  8. Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

    Science.gov (United States)

    Rapp, F.; Schneider, A.; Elsner, P.

    2014-05-01

    Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength).

  9. Liquid versus foam sclerotherapy.

    Science.gov (United States)

    Hamel-Desnos, C; Allaert, F-A

    2009-12-01

    A systematic review to compare efficacy and safety of foam (F) sclerotherapy versus liquid (L) sclerotherapy for primary varicose veins of the lower limbs. Systematic searches of electronic databases were conducted in April 2009 to identify relevant published studies. Database searches were augmented with abstracts from conference proceedings and electronic and hand searching of journals not consistently indexed in the major databases. For treatment of saphenous veins, six trials (four randomized controlled trials) were considered. Despite containing much less sclerosing agent, F was markedly more effective compared with L, the difference being put at between 20% and 50%. Four studies were included in a meta-analysis showing efficacy of F at 76.8% (95% confidence interval [CI] 71-82) versus L at 39.5% (95% CI 33-46), chi(2) = 60.9740; P reticular veins and telangiectases, only two comparative trials were found and do not at present provide any conclusive evidence to support the superiority of efficacy of one form over the other. Statistically, the side-effects reported in all the available comparative trials do not differ between F and L forms, even if visual disturbances seem to be more common with F. In the treatment of varices of the lower limbs, F shows much greater efficacy compared to L. Concerning the side effects, no statistical significant differences were found between L and F.

  10. Foam-mat drying technology: A review.

    Science.gov (United States)

    Hardy, Z; Jideani, V A

    2017-08-13

    This article reviews various aspects of foam-mat drying such as foam-mat drying processing technique, main additives used for foam-mat drying, foam-mat drying of liquid and solid foods, quality characteristics of foam-mat dried foods, and economic and technical benefits for employing foam-mat drying. Foam-mat drying process is an alternative method that allows the removal of water from liquid materials and pureed materials. In this drying process, a liquid material is converted into foam that is stable by being whipped after adding an edible foaming agent. The stable foam is then spread out in sheet or mat and dried by using hot air (40-90°C) at atmospheric pressure. Methyl cellulose (0.25-2%), egg white (3-20%), maltodextrin (0.5-05%), and gum Arabic (2-9%) are the commonly utilized additives for the foam-mat drying process at the given range, either combined together for their effectiveness or individual effect. The foam-mat drying process is suitable for heat sensitive, viscous, and sticky products that cannot be dried using other forms of drying methods such as spray drying because of the state of product. More interest has developed for foam-mat drying because of the simplicity, cost effectiveness, high speed drying, and improved product quality it provides.

  11. Stability analysis of uniform equilibrium foam states for EOR processes

    NARCIS (Netherlands)

    Ashoori, E.; Marchesin, D.; Rossen, W.R.

    2011-01-01

    The use of foam for mobility control is a promising mean to improve sweep efficiency in EOR. Experimental studies discovered that foam exhibits three different states (weak foam, intermediate foam, and strong foam). The intermediate-foam state is found to be unstable in the lab whereas the weak- and

  12. TH-C-12A-09: Planning and Delivery of the Fully Dynamic Trajectory Modulated Arc Therapy: Application to Accelerated Partial Breast Irradiation

    International Nuclear Information System (INIS)

    Liang, J; Atwood, T; Fahimian, B; Chin, E; Hristov, D; Otto, K

    2014-01-01

    Purpose: A novel trajectory modulated arc therapy (TMAT) system was developed that uses source motion trajectory involving synchronized gantry rotation with translational and rotational couch movement. MLC motion and dose rate were fully optimized for dynamic beam delivery. This work presents a platform for planning deliverable TMAT on a collision free coronal trajectory and evaluates its benefit for accelerated partial breast irradiation (APBI) in a prone position. Methods: The TMAT algorithm was built on VMAT with modifications (physical properties on couch movement were defined) and enhancements (pencil beam dose calculation engine to support extended SSDs) to make it feasible for TMAT delivery. A Matlab software environment for TMAT optimization and dose calculation was created to allow any user specified motion axis. TMAT delivery was implemented on Varian TrueBeamTM STx via XML scripts. 10 prone breast irradiation cases were evaluated in VMAT and compared with a 6- field non-coplanar IMRT plan. Patient selection/exclusion criteria and structure contouring followed the guidelines of NSABP B-39/RTOG 0413 protocol. Results: TMAT delivery time was ∼4.5 minutes. 251.5°±7.88° of non-isocentric couch arc was achieved by the optimized trajectory with 180– 210 control points at 1°–2° couch increments. The improved dose distribution by TMAT was most clearly observed by the marked reduction in the volume of irradiated normal breast tissue in the high dose region. The ratios of the normal breast tissue volume receiving more than 50%, 80% and 100% of the prescription dose for TMAT versus IMRT were: V50%(TMAT/IMRT) = 78.38%±13.03%, V80%(TMAT/IMRT) = 44.19%±9.04% and V100% (TMAT/IMRT) = 9.96%±7.55%, all p≤0.01. Conclusion: The study is the first demonstration of planning and delivery implementation of a fully dynamic APBI TMAT system with continuous couch motion. TMAT achieved significantly improved dosimetry over noncoplanar IMRT on dose volume parameters

  13. TH-C-12A-09: Planning and Delivery of the Fully Dynamic Trajectory Modulated Arc Therapy: Application to Accelerated Partial Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Liang, J; Atwood, T; Fahimian, B; Chin, E; Hristov, D [Department of Radiation Oncology, Stanford University, CA (United States); Otto, K [Department of Physics, University of British Columbia, BC (Canada)

    2014-06-15

    Purpose: A novel trajectory modulated arc therapy (TMAT) system was developed that uses source motion trajectory involving synchronized gantry rotation with translational and rotational couch movement. MLC motion and dose rate were fully optimized for dynamic beam delivery. This work presents a platform for planning deliverable TMAT on a collision free coronal trajectory and evaluates its benefit for accelerated partial breast irradiation (APBI) in a prone position. Methods: The TMAT algorithm was built on VMAT with modifications (physical properties on couch movement were defined) and enhancements (pencil beam dose calculation engine to support extended SSDs) to make it feasible for TMAT delivery. A Matlab software environment for TMAT optimization and dose calculation was created to allow any user specified motion axis. TMAT delivery was implemented on Varian TrueBeamTM STx via XML scripts. 10 prone breast irradiation cases were evaluated in VMAT and compared with a 6- field non-coplanar IMRT plan. Patient selection/exclusion criteria and structure contouring followed the guidelines of NSABP B-39/RTOG 0413 protocol. Results: TMAT delivery time was ∼4.5 minutes. 251.5°±7.88° of non-isocentric couch arc was achieved by the optimized trajectory with 180– 210 control points at 1°–2° couch increments. The improved dose distribution by TMAT was most clearly observed by the marked reduction in the volume of irradiated normal breast tissue in the high dose region. The ratios of the normal breast tissue volume receiving more than 50%, 80% and 100% of the prescription dose for TMAT versus IMRT were: V50%(TMAT/IMRT) = 78.38%±13.03%, V80%(TMAT/IMRT) = 44.19%±9.04% and V100% (TMAT/IMRT) = 9.96%±7.55%, all p≤0.01. Conclusion: The study is the first demonstration of planning and delivery implementation of a fully dynamic APBI TMAT system with continuous couch motion. TMAT achieved significantly improved dosimetry over noncoplanar IMRT on dose volume parameters

  14. Guidelines for radiation oncology centres in AFRA Member States intending to make a transition from 2-D to 3-D treatment planning and delivery

    International Nuclear Information System (INIS)

    Meghzifene, A.

    2007-01-01

    The IAEA Regional Technical Cooperation Project RAF/6/031 on Medical Physics in Support of Cancer Management aims to strengthen national and regional medical physics capabilities to sustain radiotherapy treatments in the AFRA1 Member States. In particular, it aims at increasing the number of qualified medical physicists in the region as well as improving the level of medical physics by establishing regional training and continuous development programmes. Eighteen National Project Coordinators (NPCs) nominated by participating AFRA Member States are engaged in the project. RAF/6/031 was approved by the IAEA in 2005 for an initial five year duration. A coordination meeting is held every two years where the NPCs and IAEA Technical and Project Management Officers establish the project's training and development programmes. During the first coordination meeting at Cape Town in November 2005, it was decided to convene a Task Force Meeting to review the status of treatment planning in radiotherapy in AFRA Member States and prepare a guidance document on the transition from 2-D to 3-D treatment planning. This Task Force Meeting took place at the IAEA's Headquarters in Vienna on 23-26 April 2007. The resulting guidance document highlights the milestones that have to be achieved by radiotherapy centres routinely implementing 2-D computerized treatment planning before making a transition to 3-D treatment planning and delivery. The implementation of 3-D planning by radiotherapy centres that have not yet met these milestones could lead to serious mistakes in treatments. A self-assessment questionnaire was also prepared during the Task Force Meeting. Member States that are planning to make a transition to 3-D planning are advised to assess their existing capabilities through this questionnaire. The same questionnaire could also be useful for the IAEA staff and external experts when assessing the readiness of a radiotherapy centre to make a safe and effective transition to 3-D

  15. SU-D-BRC-03: Development and Validation of an Online 2D Dose Verification System for Daily Patient Plan Delivery Accuracy Check

    International Nuclear Information System (INIS)

    Zhao, J; Hu, W; Xing, Y; Wu, X; Li, Y

    2016-01-01

    Purpose: All plan verification systems for particle therapy are designed to do plan verification before treatment. However, the actual dose distributions during patient treatment are not known. This study develops an online 2D dose verification tool to check the daily dose delivery accuracy. Methods: A Siemens particle treatment system with a modulated scanning spot beam is used in our center. In order to do online dose verification, we made a program to reconstruct the delivered 2D dose distributions based on the daily treatment log files and depth dose distributions. In the log files we can get the focus size, position and particle number for each spot. A gamma analysis is used to compare the reconstructed dose distributions with the dose distributions from the TPS to assess the daily dose delivery accuracy. To verify the dose reconstruction algorithm, we compared the reconstructed dose distributions to dose distributions measured using PTW 729XDR ion chamber matrix for 13 real patient plans. Then we analyzed 100 treatment beams (58 carbon and 42 proton) for prostate, lung, ACC, NPC and chordoma patients. Results: For algorithm verification, the gamma passing rate was 97.95% for the 3%/3mm and 92.36% for the 2%/2mm criteria. For patient treatment analysis,the results were 97.7%±1.1% and 91.7%±2.5% for carbon and 89.9%±4.8% and 79.7%±7.7% for proton using 3%/3mm and 2%/2mm criteria, respectively. The reason for the lower passing rate for the proton beam is that the focus size deviations were larger than for the carbon beam. The average focus size deviations were −14.27% and −6.73% for proton and −5.26% and −0.93% for carbon in the x and y direction respectively. Conclusion: The verification software meets our requirements to check for daily dose delivery discrepancies. Such tools can enhance the current treatment plan and delivery verification processes and improve safety of clinical treatments.

  16. WE-EF-BRA-03: Catheter- Free Ablation with External Photon Radiation: Treatment Planning, Delivery Considerations, and Correlation of Effects with Delivered Dose

    International Nuclear Information System (INIS)

    Deisher, A; Anderson, S; Cusma, J; Herman, M; Johnson, S; Lehmann, H; Packer, D; Parker, K; Song, L; Takami, M; Kruse, J

    2015-01-01

    Purpose: To plan, target, and calculate delivered dose in atrioventricular node (AVN) ablation with volume-modulated arc therapy (VMAT) in an intact porcine model. Methods: Seven pigs underwent AVN irradiation, with prescription doses ranging between 25 and 55Gy in a single fraction. Cardiac CT scans were acquired at expiration. Two physicians contoured AVN targets on 10 phases, providing estimates of target motion and inter-physician variability. Treatment planning was conducted on a static phase-averaged CT. The volume designated to receive prescription dose covered the full extent of AVN cardiac motion, expanded by 4mm for setup uncertainty. Optimization limited doses to risk structures according to single-fraction tumor treatment protocols. Orthogonal kV images were used to align bony anatomy at time of treatment. Localization was further refined with respiratory-gated cone-beam CT, and range of cardiac motion was verified under fluoroscopy. Beam delivery was respiratory-gated for expiration with a mean efficiency of 60%. Deformable registration of the 10 cardiac CT phases was used to calculate actual delivered dose for comparison to electro-anatomical and visually evident lesions. Results: The mean [minimum,maximum] amplitude of AVN cardiac motion was LR 2.9 [1.7,3.9]mm, AP 6.6 [4.4,10.4]mm, and SI 5.6 [2.0,9.9]mm. Incorporating cardiac motion into the dose calculation showed the volume receiving full dose was 40–80% of the volume indicated on the static planning image, although the contoured AVN target received full dose in all animals. Initial results suggest the dimensions of the electro-anatomical lesion are correlated with the 40Gy isodose volume. Conclusion: Image-guidance techniques allow for accurate and precise delivery of VMAT for catheter-free arrhythmia ablation. An arsenal of advanced radiation planning, dose optimization, and image-guided delivery techniques was employed to assess and mitigate effects of cardiac and respiratory motion

  17. WE-EF-BRA-03: Catheter- Free Ablation with External Photon Radiation: Treatment Planning, Delivery Considerations, and Correlation of Effects with Delivered Dose

    Energy Technology Data Exchange (ETDEWEB)

    Deisher, A; Anderson, S; Cusma, J; Herman, M; Johnson, S; Lehmann, H; Packer, D; Parker, K; Song, L; Takami, M; Kruse, J [Mayo Clinic, Rochester, MN (United States)

    2015-06-15

    Purpose: To plan, target, and calculate delivered dose in atrioventricular node (AVN) ablation with volume-modulated arc therapy (VMAT) in an intact porcine model. Methods: Seven pigs underwent AVN irradiation, with prescription doses ranging between 25 and 55Gy in a single fraction. Cardiac CT scans were acquired at expiration. Two physicians contoured AVN targets on 10 phases, providing estimates of target motion and inter-physician variability. Treatment planning was conducted on a static phase-averaged CT. The volume designated to receive prescription dose covered the full extent of AVN cardiac motion, expanded by 4mm for setup uncertainty. Optimization limited doses to risk structures according to single-fraction tumor treatment protocols. Orthogonal kV images were used to align bony anatomy at time of treatment. Localization was further refined with respiratory-gated cone-beam CT, and range of cardiac motion was verified under fluoroscopy. Beam delivery was respiratory-gated for expiration with a mean efficiency of 60%. Deformable registration of the 10 cardiac CT phases was used to calculate actual delivered dose for comparison to electro-anatomical and visually evident lesions. Results: The mean [minimum,maximum] amplitude of AVN cardiac motion was LR 2.9 [1.7,3.9]mm, AP 6.6 [4.4,10.4]mm, and SI 5.6 [2.0,9.9]mm. Incorporating cardiac motion into the dose calculation showed the volume receiving full dose was 40–80% of the volume indicated on the static planning image, although the contoured AVN target received full dose in all animals. Initial results suggest the dimensions of the electro-anatomical lesion are correlated with the 40Gy isodose volume. Conclusion: Image-guidance techniques allow for accurate and precise delivery of VMAT for catheter-free arrhythmia ablation. An arsenal of advanced radiation planning, dose optimization, and image-guided delivery techniques was employed to assess and mitigate effects of cardiac and respiratory motion

  18. SU-D-BRC-03: Development and Validation of an Online 2D Dose Verification System for Daily Patient Plan Delivery Accuracy Check

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, J; Hu, W [Fudan University Shanghai Cancer Center, Shanghai, Shanghai (China); Xing, Y [Fudan univercity shanghai proton and heavy ion center, Shanghai (China); Wu, X [Fudan university shanghai proton and heavy ion center, Shanghai, shagnhai (China); Li, Y [Department of Medical physics at Shanghai Proton and Heavy Ion Center, Shanghai, Shanghai (China)

    2016-06-15

    Purpose: All plan verification systems for particle therapy are designed to do plan verification before treatment. However, the actual dose distributions during patient treatment are not known. This study develops an online 2D dose verification tool to check the daily dose delivery accuracy. Methods: A Siemens particle treatment system with a modulated scanning spot beam is used in our center. In order to do online dose verification, we made a program to reconstruct the delivered 2D dose distributions based on the daily treatment log files and depth dose distributions. In the log files we can get the focus size, position and particle number for each spot. A gamma analysis is used to compare the reconstructed dose distributions with the dose distributions from the TPS to assess the daily dose delivery accuracy. To verify the dose reconstruction algorithm, we compared the reconstructed dose distributions to dose distributions measured using PTW 729XDR ion chamber matrix for 13 real patient plans. Then we analyzed 100 treatment beams (58 carbon and 42 proton) for prostate, lung, ACC, NPC and chordoma patients. Results: For algorithm verification, the gamma passing rate was 97.95% for the 3%/3mm and 92.36% for the 2%/2mm criteria. For patient treatment analysis,the results were 97.7%±1.1% and 91.7%±2.5% for carbon and 89.9%±4.8% and 79.7%±7.7% for proton using 3%/3mm and 2%/2mm criteria, respectively. The reason for the lower passing rate for the proton beam is that the focus size deviations were larger than for the carbon beam. The average focus size deviations were −14.27% and −6.73% for proton and −5.26% and −0.93% for carbon in the x and y direction respectively. Conclusion: The verification software meets our requirements to check for daily dose delivery discrepancies. Such tools can enhance the current treatment plan and delivery verification processes and improve safety of clinical treatments.

  19. Foam for combating mine fires

    Energy Technology Data Exchange (ETDEWEB)

    1989-09-01

    The application of foam in dealing with underground fire is well known due to its smothering action by cutting off air feed to burning fuel as well as acting as coolant. Besides plugging air feed to fire, water could be virtually reached to the fire affected areas much beyond the jet range as underground galleries with low roof restrict jet range of water. This method also enables a closer approach of a fire fighting team by isolating the toxic gases and smoke with a foam plug. The paper describes the development of high expansion foam composition and its application technology in order that foam plug method can be suitably utilized for combating mine fires in India. Three compositions were recommended for generation of high expansion foam: (a) 0.5% sodium/ammonium lauryl sulphate, 0.15 to 0.2% sodium carboxy methyl cellulose, 0.1% booster; (b) 0.5% sodium/ammonium lauryl sulfate, 0.12 to 0.15% alkaline solution of gum arabic, 0.1 to 0.2% ferrous gluconate; and (c) 0.35% sodium/ammonium lauryl sulfate, 0.20% booster, 0.2% xylene sulfonate.

  20. Numerical modeling of foam flows

    International Nuclear Information System (INIS)

    Cheddadi, Ibrahim

    2010-01-01

    Liquid foam flows are involved in numerous applications, e.g. food and cosmetics industries, oil extraction, nuclear decontamination. Moreover, their study leads to fundamental knowledge: as it is easier to manipulate and analyse, foam is used as a model material to understand the flow of emulsions, polymers, pastes, or cell aggregates, all of which display both solid and liquid behaviour. Systematic experiments performed by Francois Graner et al. provide precise data that emphasize the non Newtonian properties of the foam. Meanwhile, Pierre Saramito proposed a visco-elasto-plastic continuous tensorial model, akin to predict the behaviour of the foam. The goal of this thesis is to understand this complex behaviour, using these two elements. We have built and validated a resolution algorithm based on a bidimensional finite elements methods. The numerical solutions are in excellent agreement with the spatial distribution of all measured quantities, and confirm the predictive capabilities of the model. The dominant parameters have been identified and we evidenced the fact that the viscous, elastic, and plastic contributions to the flow have to be treated simultaneously in a tensorial formalism. We provide a substantial contribution to the understanding of foams and open the path to realistic simulations of complex VEP flows for industrial applications. (author)

  1. A graphite foam reinforced by graphite particles

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J.J.; Wang, X.Y.; Guo, L.F.; Wang, Y.M.; Wang, Y.P.; Yu, M.F.; Lau, K.T.T. [DongHua University, Shanghai (China). College of Material Science and Engineering

    2007-11-15

    Graphite foam was obtained after carbonization and graphitization of a pitch foam formed by the pyrolysis of coal tar based mesophase pitch mixed with graphite particles in a high pressure and temperature chamber. The graphite foam possessed high mechanical strength and exceptional thermal conductivity after adding the graphite particles. Experimental results showed that the thermal conductivity of modified graphite foam reached 110W/m K, and its compressive strength increased from 3.7 MPa to 12.5 MPa with the addition of 5 wt% graphite particles. Through the microscopic observation, it was also found that fewer micro-cracks were formed in the cell wall of the modified foam as compared with pure graphite foam. The graphitization degree of modified foam reached 84.9% and the ligament of graphite foam exhibited high alignment after carbonization at 1200{sup o}C for 3 h and graphitization at 3000{sup o}C for 10 min.

  2. Some aspects of image processing using foams

    International Nuclear Information System (INIS)

    Tufaile, A.; Freire, M.V.; Tufaile, A.P.B.

    2014-01-01

    We have explored some concepts of chaotic dynamics and wave light transport in foams. Using some experiments, we have obtained the main features of light intensity distribution through foams. We are proposing a model for this phenomenon, based on the combination of two processes: a diffusive process and another one derived from chaotic dynamics. We have presented a short outline of the chaotic dynamics involving light scattering in foams. We also have studied the existence of caustics from scattering of light from foams, with typical patterns observed in the light diffraction in transparent films. The nonlinear geometry of the foam structure was explored in order to create optical elements, such as hyperbolic prisms and filters. - Highlights: • We have obtained the light scattering in foams using experiments. • We model the light transport in foams using a chaotic dynamics and a diffusive process. • An optical filter based on foam is proposed

  3. FoamVis, A Visualization System for Foam Research: Design and Implementation

    Directory of Open Access Journals (Sweden)

    Dan R. Lipsa

    2015-03-01

    Full Text Available Liquid foams are used in areas such as mineral separation, oil recovery, food and beverage production, sanitation and fire fighting. To improve the quality of products and the efficiency of processes in these areas, foam scientists wish to understand and control foam behaviour. To this end, foam scientists have used foam simulations to model foam behaviour; however, analysing these simulations presents difficult challenges. We describe the main foam research challenges and present the design of FoamVis, the only existing visualization, exploration and analysis application created to address them. We describe FoamVis’ main features, together with relevant design and implementation notes. Our goal is to provide a global overview and individual feature implementation details that would allow a visualization scientist to extend the FoamVis system with new algorithms and adapt it to new requirements. The result is a detailed presentation of the software that is not provided in previous visualization research papers.

  4. Sound Velocity in Soap Foams

    International Nuclear Information System (INIS)

    Wu Gong-Tao; Lü Yong-Jun; Liu Peng-Fei; Li Yi-Ning; Shi Qing-Fan

    2012-01-01

    The velocity of sound in soap foams at high gas volume fractions is experimentally studied by using the time difference method. It is found that the sound velocities increase with increasing bubble diameter, and asymptotically approach to the value in air when the diameter is larger than 12.5 mm. We propose a simple theoretical model for the sound propagation in a disordered foam. In this model, the attenuation of a sound wave due to the scattering of the bubble wall is equivalently described as the effect of an additional length. This simplicity reasonably reproduces the sound velocity in foams and the predicted results are in good agreement with the experiments. Further measurements indicate that the increase of frequency markedly slows down the sound velocity, whereas the latter does not display a strong dependence on the solution concentration

  5. Influence of the glass particle size on the foaming process and physical characteristics of foam glasses

    DEFF Research Database (Denmark)

    König, Jakob; Petersen, Rasmus Rosenlund; Yue, Yuanzheng

    2016-01-01

    We have prepared low-density foam glasses from cathode-ray-tube panel glass using carbon and MnO2 as the foaming agents. The effect of the glass particle size on the foaming process, the apparent density and the pore morphology is revealed. The results show that the foaming is mainly caused...... by the reduction of manganese. Foam glasses with a density of

  6. Modelling of Churn-Annular foam flows

    NARCIS (Netherlands)

    Westende, J.M.C. van 't; Shoeibi Omrani, P.; Vercauteren, F.F.; Nennie, E.D.

    2016-01-01

    Foam assisted lift is a deliquification method in the oil and gas industry, which aims to prevent or postpone countercurrent gas-liquid flow in maturing gas wells or to assist in removing downhole accumulated liquids. According to Nimwegen, who performed experiments with foam flows, foam

  7. Recycle Glass in Foam Glass Production

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses...... in foam glass industry and the supply sources and capacity of recycle glass....

  8. Pipe Decontamination Involving String-Foam Circulation

    International Nuclear Information System (INIS)

    Turchet, J.P.; Estienne, G.; Fournel, B.

    2002-01-01

    Foam applications number for nuclear decontamination purposes has recently increased. The major advantage of foam decontamination is the reduction of secondary liquid wastes volumes. Among foam applications, we focus on foam circulation in contaminated equipment. Dynamic properties of the system ensures an homogeneous and rapid effect of the foam bed-drifted chemical reagents present in the liquid phase. This paper describes a new approach of foam decontamination for pipes. It is based on an alternated air and foam injections. We called it 'string-foam circulation'. A further reduction of liquid wastes is achieved compared to continuous foam. Secondly, total pressure loss along the pipe is controlled by the total foam length in the pipe. It is thus possible to clean longer pipes keeping the pressure under atmospheric pressure value. This ensures the non dispersion of contamination. This study describes experimental results obtained with a neutral foam as well with an acid foam on a 130 m long loop. Finally, the decontamination of a 44 meters pipe is presented. (authors)

  9. Investigation of field temperature in moulds of foamed plaster

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2007-12-01

    Full Text Available Plaster moulds used in precision foundry are characterized by a very low permeability which, in the case of classic plaster moulds, equals to about 0,01÷0,02 m2/(MPa·s. One of the most effective methods for increasing the permeability is a foaming treatment. Another characteristic feature of plaster is its very good insulating power which has influence on the process of solidification and cooling of a cast and also on a knock-out property. This insulating power is a function of thermophysical properties of plaster which, in turn, depend mainly on the mineralogical composition of the mould material, its bulk density as well as on the temperature of the pouring alloy. In the case of a foamed plaster mould an increase of the degree of foaming increases its porosity which causes a change in its thermophysical properties, thereby increasing susceptibility of the mass to overheating. The susceptibility of the plaster layer surrounding the cast to overheating is favorable because it makes it easier to knock-out of the cast by immersing the hot mould in cold water. Thermal and phase tensions that are created during this process cause fast destruction of plaster. This paper describes our investigations aimed at the determination of the dependence of the mould temperature field on the time of the cast stay in the mould, as recorded in a process of an unsteady heat flow. The determined data were planned to be used for estimation of the technological properties of the plaster mould. The tests were carried out using the plaster α-Supraduro and Alkanol XC (foaming agent. The test mould had a diameter of Ø 120 mm with centrally situated mould cavity of Ø 30 mm. Plaster moulds with a degree of foaming 20; 32,5 and 45% and comparatively from non-foaming plaster were tested and their temperatures were measured at the distance x=2; 9; 21; 25;27; 30 mm from the mould cavity within 25 min. Analysis of the results leads to the conclusion, that the highest

  10. Silicone foam for penetration seal

    International Nuclear Information System (INIS)

    Hoshino, Yoshikazu

    1986-01-01

    In nuclear power plants or general buildings, it is very important to form a fire-resistant seal around cables, cable trays and conduits passing through a wall or a floor. Rockwool, asbestos, glasswool and flame-retarded urethane foam have so far been used for these purposes. However, they were not satisfactory in sealing property, workability and safety. The silicone foam newly developed, ''TOSSEAL'' 300, has cleared these defects. It has now come to be used for fire resistant seal in nuclear power plants. (author)

  11. Heat exchanger using graphite foam

    Science.gov (United States)

    Campagna, Michael Joseph; Callas, James John

    2012-09-25

    A heat exchanger is disclosed. The heat exchanger may have an inlet configured to receive a first fluid and an outlet configured to discharge the first fluid. The heat exchanger may further have at least one passageway configured to conduct the first fluid from the inlet to the outlet. The at least one passageway may be composed of a graphite foam and a layer of graphite material on the exterior of the graphite foam. The layer of graphite material may form at least a partial barrier between the first fluid and a second fluid external to the at least one passageway.

  12. Quantifying the retention of foam formulation components to sedimentary phases to enable predictions of mobility and treatment efficacy - 59369

    International Nuclear Information System (INIS)

    Ramirez, Rosa; Jansik, Danielle; Wellman, Dawn

    2012-01-01

    Document available in abstract form only. Full text of publication follows: Deep vadose zone remediation remains the most challenging remediation problem in the DOE Complex. Foam delivery technology is being developed as a method for delivering remedial amendments within vadose zone environments for in situ contaminant stabilization. Thus far, the physical propagation of foam within subsurface media has been evaluated and quantified. However, foam propagation is a product of surfactant sorption which directly impacts foam stability. In order to predict the stability of foam during subsurface transport it is necessary to quantify the sorption of foam components as a function of concentration, competitive sorption, sediment mineralogy, and temperature. This investigation provides the results of standard static batch test quantifying these relationships. High Performance Liquid Chromatography (HPLC) was used to measure surfactant concentrations. The results of this investigation provide necessary understanding to predict foam stability during subsurface transport and determination of the remedial radius of influence. This study is part of a multiple step process for demonstrating the feasibility of foam transport to distribute amendments within in the vadose zone. (authors)

  13. Foam Transport in Porous Media - A Review

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.; Freedman, Vicky L.; Zhong, Lirong

    2009-11-11

    Amendment solutions with or without surfactants have been used to remove contaminants from soil. However, it has drawbacks such that the amendment solution often mobilizes the plume, and its movement is controlled by gravity and preferential flow paths. Foam is an emulsion-like, two-phase system in which gas cells are dispersed in a liquid and separated by thin liquid films called lamellae. Potential advantages of using foams in sub-surface remediation include providing better control on the volume of fluids injected, uniformity of contact, and the ability to contain the migration of contaminant laden liquids. It is expected that foam can serve as a carrier of amendments for vadose zone remediation, e.g., at the Hanford Site. As part of the U.S. Department of Energy’s EM-20 program, a numerical simulation capability will be added to the Subsurface Transport Over Multiple Phases (STOMP) flow simulator. The primary purpose of this document is to review the modeling approaches of foam transport in porous media. However, as an aid to understanding the simulation approaches, some experiments under unsaturated conditions and the processes of foam transport are also reviewed. Foam may be formed when the surfactant concentration is above the critical micelle concentration. There are two main types of foams – the ball foam (microfoam) and the polyhedral foam. The characteristics of bulk foam are described by the properties such as foam quality, texture, stability, density, surface tension, disjoining pressure, etc. Foam has been used to flush contaminants such as metals, organics, and nonaqueous phase liquids from unsaturated soil. Ball foam, or colloidal gas aphrons, reportedly have been used for soil flushing in contaminated site remediation and was found to be more efficient than surfactant solutions on the basis of weight of contaminant removed per gram of surfactant. Experiments also indicate that the polyhedral foam can be used to enhance soil remediation. The

  14. Stretching and folding mechanism in foams

    International Nuclear Information System (INIS)

    Tufaile, Alberto; Pedrosa Biscaia Tufaile, Adriana

    2008-01-01

    We have described the stretching and folding of foams in a vertical Hele-Shaw cell containing air and a surfactant solution, from a sequence of upside-down flips. Besides the fractal dimension of the foam, we have observed the logistic growth for the soap film length. The stretching and folding mechanism is present during the foam formation, and this mechanism is observed even after the foam has reached its respective maximum fractal dimension. Observing the motion of bubbles inside the foam, large bubbles present power spectrum associated with random walk motion in both directions, while the small bubbles are scattered like balls in a Galton board

  15. Method of making a cyanate ester foam

    Science.gov (United States)

    Celina, Mathias C.; Giron, Nicholas Henry

    2014-08-05

    A cyanate ester resin mixture with at least one cyanate ester resin, an isocyanate foaming resin, other co-curatives such as polyol or epoxy compounds, a surfactant, and a catalyst/water can react to form a foaming resin that can be cured at a temperature greater than 50.degree. C. to form a cyanate ester foam. The cyanate ester foam can be heated to a temperature greater than 400.degree. C. in a non-oxidative atmosphere to provide a carbonaceous char foam.

  16. Stretching and folding mechanism in foams

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, Alberto [Escola de Artes, Ciencias e Humanidades, Soft Matter Laboratory, Universidade de Sao Paulo, 03828-000 Sao Paulo, SP (Brazil)], E-mail: tufaile@usp.br; Pedrosa Biscaia Tufaile, Adriana [Escola de Artes, Ciencias e Humanidades, Soft Matter Laboratory, Universidade de Sao Paulo, 03828-000 Sao Paulo, SP (Brazil)

    2008-10-13

    We have described the stretching and folding of foams in a vertical Hele-Shaw cell containing air and a surfactant solution, from a sequence of upside-down flips. Besides the fractal dimension of the foam, we have observed the logistic growth for the soap film length. The stretching and folding mechanism is present during the foam formation, and this mechanism is observed even after the foam has reached its respective maximum fractal dimension. Observing the motion of bubbles inside the foam, large bubbles present power spectrum associated with random walk motion in both directions, while the small bubbles are scattered like balls in a Galton board.

  17. Glycolysis of flexible polyurethane foam in recycling of car seats

    Czech Academy of Sciences Publication Activity Database

    Beneš, Hynek; Rösner, J.; Holler, Petr; Synková, Hana; Kotek, Jiří; Horák, Zdeněk

    2007-01-01

    Roč. 18, č. 2 (2007), s. 149-156 ISSN 1042-7147. [International Conference on Polymeric Materials in Automotive , Slovak Rubber Conference /17./. Bratislava, 10.5.2005-12.5.2005] R&D Projects: GA MŽP SL/7/26/05 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyurethanes * foams * recycling Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.504, year: 2007

  18. Foaming/antifoaming in WTP Tanks Equipped with Pulse Jet Mixer and Air Spargers

    International Nuclear Information System (INIS)

    HASSAN, NEGUIB

    2004-01-01

    The River Protection Project-Waste Treatment Plant (RPP-WTP) requested Savannah River National Laboratory (SRNL) to conduct small-scale foaming and antifoam testing using actual Hanford waste and simulants subjected to air sparging. The foaminess of Hanford tank waste solutions was previously demonstrated in SRNL during WTP evaporator foaming and ultrafiltration studies and commercial antifoam DOW Q2-3183A was recommended to mitigate the foam in the evaporators. Currently, WTP is planning to use air spargers in the HLW Lag Storage Vessels, HLW Concentrate Receipt Vessel, and the Ultrafiltration Vessels to assist the performance of the Jet Pulse Mixers (JPM). Sparging of air into WTP tanks will induce a foam layer within the process vessels. The air dispersion in the waste slurries and generated foams could present problems during plant operation. Foam in the tanks could also adversely impact hydrogen removal and mitigation. Antifoam (DOW Q2-3183A) will be used to control foaming in Hanford sparged waste processing tanks. These tanks will be mixed by a combination of pulse-jet mixers and air spargers. The percent allowable foaminess or freeboard in WTP tanks are shown in tables

  19. Helical Tomotherapy-Based STAT Stereotactic Body Radiation Therapy: Dosimetric Evaluation for a Real-Time SBRT Treatment Planning and Delivery Program

    International Nuclear Information System (INIS)

    Dunlap, Neal; McIntosh, Alyson; Sheng Ke; Yang Wensha; Turner, Benton; Shoushtari, Asal; Sheehan, Jason; Jones, David R.; Lu Weigo; Ruchala, Keneth; Olivera, Gustavo; Parnell, Donald; Larner, James L.; Benedict, Stanley H.; Read, Paul W.

    2010-01-01

    iterations or 135 sec for STAT RT liver and lung SBRT plans and 7 iterations or 315 sec for STAT RT spine SBRT plans. Helical TomoTherapy-based STAT RT treatment planning with the 'full scatter' algorithm provides levels of dosimetric conformality, heterogeneity, and OAR avoidance for SBRT treatments that are clinically equivalent to those generated with the Helical TomoTherapy 'beamlet' algorithm. STAT RT calculation times for simple SBRT treatments are fast enough to warrant further investigation into their potential incorporation into an SBRT program with daily real-time planning. Development of methods for accurate target and OAR determination on megavoltage computed tomography scans incorporating high-resolution diagnostic image co-registration software and CT detector-based exit dose measurement for quality assurance are necessary to build a real-time SBRT planning and delivery program.

  20. Bio-based Polymer Foam from Soyoil

    Science.gov (United States)

    Bonnaillie, Laetitia M.; Wool, Richard P.

    2006-03-01

    The growing bio-based polymeric foam industry is presently lead by plant oil-based polyols for polyurethanes and starch foams. We developed a new resilient, thermosetting foam system with a bio-based content higher than 80%. The acrylated epoxidized soybean oil and its fatty acid monomers is foamed with pressurized carbon dioxide and cured with free-radical initiators. The foam structure and pore dynamics are highly dependent on the temperature, viscosity and extent of reaction. Low-temperature cure hinds the destructive pore coalescence and the application of a controlled vacuum results in foams with lower densities ˜ 0.1 g/cc, but larger cells. We analyze the physics of foam formation and stability, as well as the structure and mechanical properties of the cured foam using rigidity percolation theory. The parameters studied include temperature, vacuum applied, and cross-link density. Additives bring additional improvements: nucleating agents and surfactants help produce foams with a high concentration of small cells and low bulk density. Hard and soft thermosetting foams with a bio content superior to 80% are successfully produced and tested. Potential applications include foam-core composites for hurricane-resistant housing, structural reinforcement for windmill blades, and tissue scaffolds.

  1. Numerical Modeling of Foam Drilling Hydraulics

    Directory of Open Access Journals (Sweden)

    Ozcan Baris

    2007-12-01

    Full Text Available The use of foam as a drilling fluid was developed to meet a special set of conditions under which other common drilling fluids had failed. Foam drilling is defined as the process of making boreholes by utilizing foam as the circulating fluid. When compared with conventional drilling, underbalanced or foam drilling has several advantages. These advantages include: avoidance of lost circulation problems, minimizing damage to pay zones, higher penetration rates and bit life. Foams are usually characterized by the quality, the ratio of the volume of gas, and the total foam volume. Obtaining dependable pressure profiles for aerated (gasified fluids and foam is more difficult than for single phase fluids, since in the former ones the drilling mud contains a gas phase that is entrained within the fluid system. The primary goal of this study is to expand the knowledge-base of the hydrodynamic phenomena that occur in a foam drilling operation. In order to gain a better understanding of foam drilling operations, a hydrodynamic model is developed and run at different operating conditions. For this purpose, the flow of foam through the drilling system is modeled by invoking the basic principles of continuum mechanics and thermodynamics. The model was designed to allow gas and liquid flow at desired volumetric flow rates through the drillstring and annulus. Parametric studies are conducted in order to identify the most influential variables in the hydrodynamic modeling of foam flow.

  2. Foaming Glass Using High Pressure Sintering

    DEFF Research Database (Denmark)

    Østergaard, Martin Bonderup; Petersen, Rasmus Rosenlund; König, Jakob

    Foam glass is a high added value product which contributes to waste recycling and energy efficiency through heat insulation. The foaming can be initiated by a chemical or physical process. Chemical foaming with aid of a foaming agent is the dominant industrial process. Physical foaming has two...... to expand. After heat-treatment foam glass can be obtained with porosities of 80–90 %. In this study we conduct physical foaming of cathode ray tube (CRT) panel glass by sintering under high pressure (5-25 MPa) using helium, nitrogen, or argon at 640 °C (~108 Pa s). Reheating a sample in a heating...... variations. One way is by saturation of glass melts with gas. The other involves sintering of powdered glass under a high gas pressure resulting in glass pellets with high pressure bubbles entrapped. Reheating the glass pellets above the glass transition temperature under ambient pressure allows the bubbles...

  3. Viscous Control of the Foam Glass Process

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Smedskjær, Morten Mattrup

    The production of foam glass as heat insulating material is an important industrial process because it enables low-cost recycling of glass waste from a variety of chemical compositions. Optimization of the foaming process of new glass waste compositions is time consuming, since many factors affect...... the foaming process such as temperature, particle size, type and concentration of foaming agent. The foaming temperature is one of the key factors, because even small temperature changes can affect the melt viscosity by several orders of magnitude. Therefore, it is important to establish the viscosity range...... in which the foaming process should take place, particularly when the type of recycled cullet is changed or several types of cullet are mixed in one batch. According to recent glass literature, the foaming process should occur at viscosity 103 to 105 Pa s. However, no systematic studies have hitherto been...

  4. Positivity of spin foam amplitudes

    International Nuclear Information System (INIS)

    Baez, John C; Christensen, J Daniel

    2002-01-01

    The amplitude for a spin foam in the Barrett-Crane model of Riemannian quantum gravity is given as a product over its vertices, edges and faces, with one factor of the Riemannian 10j symbols appearing for each vertex, and simpler factors for the edges and faces. We prove that these amplitudes are always nonnegative for closed spin foams. As a corollary, all open spin foams going between a fixed pair of spin networks have real amplitudes of the same sign. This means one can use the Metropolis algorithm to compute expectation values of observables in the Riemannian Barrett-Crane model, as in statistical mechanics, even though this theory is based on a real-time (e iS ) rather than imaginary-time e -S path integral. Our proof uses the fact that when the Riemannian 10j symbols are nonzero, their sign is positive or negative depending on whether the sum of the ten spins is an integer or half-integer. For the product of 10j symbols appearing in the amplitude for a closed spin foam, these signs cancel. We conclude with some numerical evidence suggesting that the Lorentzian 10j symbols are always nonnegative, which would imply similar results for the Lorentzian Barrett-Crane model

  5. "Grinding" cavities in polyurethane foam

    Science.gov (United States)

    Brower, J. R.; Davey, R. E.; Dixon, W. F.; Robb, P. H.; Zebus, P. P.

    1980-01-01

    Grinding tool installed on conventional milling machine cuts precise cavities in foam blocks. Method is well suited for prototype or midsize production runs and can be adapted to computer control for mass production. Method saves time and materials compared to bonding or hot wire techniques.

  6. Influence of foaming agents on solid thermal conductivity of foam glasses prepared from CRT panel glass

    DEFF Research Database (Denmark)

    Østergaard, Martin Bonderup; Petersen, Rasmus Rosenlund; König, Jakob

    2017-01-01

    The understanding of the thermal transport mechanism of foam glass is still lacking. The contribution of solid- and gas conduction to the total thermal conductivity remains to be reported. In many foam glasses, the solid phase consist of a mix of an amorphous and a crystalline part where foaming...... containing glass and crystalline foaming agents and amorphous samples where the foaming agents are completely dissolved in the glass structure, respectively. Results show that the samples prepared by sintering have a higher thermal conductivity than the samples prepared by melt-quenching. The thermal...... conductivities of the sintered and the melt-quenched samples represent an upper and lower limit of the solid phase thermal conductivity of foam glasses prepared with these foaming agents. The content of foaming agents dissolved in the glass structure has a major impact on the solid thermal conductivity of foam...

  7. A pulsed mode electrolytic drug delivery device

    KAUST Repository

    Yi, Ying; Buttner, Ulrich; Carreno, Armando Arpys Arevalo; Conchouso Gonzalez, David; Foulds, Ian G.

    2015-01-01

    This paper reports the design of a proof-of-concept drug delivery device that is actuated using the bubbles formed during electrolysis. The device uses a platinum (Pt) coated nickel (Ni) metal foam and a solid drug in reservoir (SDR) approach

  8. Supplier Cooperation in Drone Delivery

    OpenAIRE

    Sawadsitang, Suttinee; Niyato, Dusit; Siew, Tan Puay; Wang, Ping

    2018-01-01

    Recently, unmanned aerial vehicles (UAVs), also known as drones, has emerged as an efficient and cost-effective solution for package delivery. Especially, drones are expected to incur lower cost, and achieve fast and environment friendly delivery. While most of existing drone research concentrates on surveillance applications, few works studied the drone package delivery planning problem. Even so, the previous works only focus on the drone delivery planning of a single supplier. In this paper...

  9. Sci—Thur PM: Planning and Delivery — 04: Respiratory margin derivation and verification in partial breast irradiation

    International Nuclear Information System (INIS)

    Quirk, S; Conroy, L; Smith, WL

    2014-01-01

    Partial breast irradiation (PBI) following breast-conserving surgery is emerging as an effective means to achieve local control and reduce irradiated breast volume. Patients are planned on a static CT image; however, treatment is delivered while the patient is free-breathing. Respiratory motion can degrade plan quality by reducing target coverage and/or dose homogeneity. A variety of methods can be used to determine the required margin for respiratory motion in PBI. We derive geometric and dosimetric respiratory 1D margin. We also verify the adequacy of the typical 5 mm respiratory margin in 3D by evaluating plan quality for increasing respiratory amplitudes (2–20 mm). Ten PBI plans were used for dosimetric evaluation. A database of volunteer respiratory data, with similar characteristics to breast cancer patients, was used for this study. We derived a geometric 95%-margin of 3 mm from the population respiratory data. We derived a dosimetric 95%-margin of 2 mm by convolving 1D dose profiles with respiratory probability density functions. The 5 mm respiratory margin is possibly too large when 1D coverage is assessed and could lead to unnecessary normal tissue irradiation. Assessing margins only for coverage may be insufficient; 3D dosimetric assessment revealed degradation in dose homogeneity is the limiting factor, not target coverage. Hotspots increased even for the smallest respiratory amplitudes, while target coverage only degraded at amplitudes greater than 10 mm. The 5 mm respiratory margin is adequate for coverage, but due to plan quality degradation, respiratory management is recommended for patients with respiratory amplitudes greater than 10 mm

  10. Project delivery system (PDS)

    CERN Document Server

    2001-01-01

    As business environments become increasingly competitive, companies seek more comprehensive solutions to the delivery of their projects. "Project Delivery System: Fourth Edition" describes the process-driven project delivery systems which incorporates the best practices from Total Quality and is aligned with the Project Management Institute and ISO Quality Standards is the means by which projects are consistently and efficiently planned, executed and completed to the satisfaction of clients and customers.

  11. 46 CFR 108.463 - Foam rate: Protein.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Foam rate: Protein. 108.463 Section 108.463 Shipping... EQUIPMENT Fire Extinguishing Systems Foam Extinguishing Systems § 108.463 Foam rate: Protein. (a) If the outlets of a protein foam extinguishing system are in a space, the foam rate at each outlet must be at...

  12. Making continuous bubble type polyethylene foam incombustible

    International Nuclear Information System (INIS)

    Kaji, Kanako; Hatada, Motoyoshi; Yoshizawa, Iwao; Komai, Kuniaki; Kohara, Choji.

    1989-01-01

    Since continuous bubble type plastic foam has excellent compression characteristics and sound absorption characteristics, it has been widely used as cushion material, sealing material, sound insulating material and so on. However, the most part of plastic foam is taken by air, therefore at the time of fires, it becomes a very dangerous material. At present, the material used mostly as the seat cushions for airliners, railroad coaches, automobiles and others is polyurethane foam, but since it contains C-N couples in its molecules, it is feared to generate cyanic gas according to the condition of combustion. As the plastic foam that does not generate harmful gas at the time of fires, there is continuous bubble type polyethylene which is excellent in its weathering property and chemical resistance. A reactive, phosphorus-containing oligomer has large molecular weight and two or more double couplings in a molecule, therefore, it does not enter the inside of polyethylene, and polymerizes and crosslinks on the surfaces of bubble walls in the foam, accordingly it is expected that the apparent graft polymerization is carried out, and it is very effective for making polyethylene foam incombustible. The method of making graft foam, the properties of graft foam and so on are reported. When the graft polymerization of this oligomer to continuous bubble type polyethylene foam was tried, highly incombustible polyethylene foam was obtained. (K.I.)

  13. Covering sources of toxic vapors with foam

    International Nuclear Information System (INIS)

    Aue, W. P.; Guidetti, F.

    2009-01-01

    In a case of chemical terrorism, first responders might well be confronted with a liquid source of toxic vapor which keeps spreading out its hazardous contents. With foam as an efficient and simple means, such a source could be covered up in seconds and the spread of vapors mitigated drastically. Once covered, the source could then wait for a longer time to be removed carefully and professionally by a decontamination team. In order to find foams useful for covering up toxic vapor sources, a large set of measurements has been performed in order to answer the following questions: - Which foams could be used for this purpose? - How thick should the foam cover be? - For how long would such a foam cover be effective? - Could the practical application of foam cause a spread of the toxic chemical? The toxic vapors sources included GB, GD and HD. Among the foams were 10 fire fighter foams (e.g. AFFF, protein) and the aqueous decontamination foam CASCAD. Small scale experiments showed that CASCAD is best suited for covering a toxic source; a 10 cm layer of it covers and decontaminates GB. The large scale experiments confirmed that any fire fighter foam is a suitable cover for a longer or shorter period.(author)

  14. Follicular and percutaneous penetration pathways of topically applied minoxidil foam.

    Science.gov (United States)

    Blume-Peytavi, Ulrike; Massoudy, Lida; Patzelt, Alexa; Lademann, Jürgen; Dietz, Ekkehart; Rasulev, Utkur; Garcia Bartels, Natalie

    2010-11-01

    In the past, it was assumed that the intercellular route was the only relevant penetration pathway for topically applied substances. Recent results on follicular penetration emphasize that the hair follicles represent a highly relevant and efficient penetration pathway and reservoir for topically applied substances. This study investigates a selective closure technique of hair follicle orifices in vivo assessing interfollicular and follicular absorption rates of topical minoxidil foam in humans. In delimited skin area, single hair orifices or interfollicular skin were blocked with a microdrop of special varnish-wax-mixture in vivo. Minoxidil foam (5%) was topically applied, and transcutaneous absorption was measured by a new surface ionization mass spectrometry technique in serum. Different settings (open, closed or none of both) enabled to clearly distinguish between interfollicular and follicular penetration of the topically applied minoxidil foam. Five minutes after topical application, minoxidil was detected in blood samples when follicles remained open, whereas with closed follicles 30 min were needed. Highest levels were found first when both pathways were open, followed by open follicles and subsequently by closed follicles. These results demonstrate the high importance of the follicular penetration pathway. Hair follicles are surrounded by a dense network of blood capillaries and dendritic cells and have stem cells in their immediate vicinity, making them ideal targets for drug delivery. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Chemicals and Structural Foams to Neutralize or Defeat Anti-Personnel Mines

    Science.gov (United States)

    1990-10-01

    first-level goals in LD. This shows the basic approach used for this analysis. I OVERALL GOALi Select Best Foam System II Best Foam Product Best Delivery...pouring back and forth three times would have three steps for that part of the process, plus any other motions, such as pulling off the lid, and...i B-II I I I I I I :’½ j> I I I I 3 Typical Tilt-Rod AP Mine I I I I I I Typical Pull Firing Pin Device H I I I I I I I iPrsu -SniiePatcCsdMn I i

  16. Improving the Simplified Acquisition of Base Engineering Requirements (SABER) Delivery Order Award Process: Results of a Process Improvement Plan

    Science.gov (United States)

    1991-09-01

    putting all tasks directed towsrds achieving an outcome in aequence. The tasks can be viewed as steps in the process (39:2.3). Using this...improvement opportunity is investigated. A plan is developed, root causes are identified, and solutions are tested and implemented. The process is... solutions , check for actual improvement, and integrate the successful improvements into the process. ?UP 7. Check Improvement Performance. Finally, the

  17. Plan delivery quality assurance for CyberKnife: Statistical process control analysis of 350 film-based patient-specific QAs.

    Science.gov (United States)

    Bellec, J; Delaby, N; Jouyaux, F; Perdrieux, M; Bouvier, J; Sorel, S; Henry, O; Lafond, C

    2017-07-01

    Robotic radiosurgery requires plan delivery quality assurance (DQA) but there has never been a published comprehensive analysis of a patient-specific DQA process in a clinic. We proposed to evaluate 350 consecutive film-based patient-specific DQAs using statistical process control. We evaluated the performance of the process to propose achievable tolerance criteria for DQA validation and we sought to identify suboptimal DQA using control charts. DQAs were performed on a CyberKnife-M6 using Gafchromic-EBT3 films. The signal-to-dose conversion was performed using a multichannel-correction and a scanning protocol that combined measurement and calibration in a single scan. The DQA analysis comprised a gamma-index analysis at 3%/1.5mm and a separate evaluation of spatial and dosimetric accuracy of the plan delivery. Each parameter was plotted on a control chart and control limits were calculated. A capability index (Cpm) was calculated to evaluate the ability of the process to produce results within specifications. The analysis of capability showed that a gamma pass rate of 85% at 3%/1.5mm was highly achievable as acceptance criteria for DQA validation using a film-based protocol (Cpm>1.33). 3.4% of DQA were outside a control limit of 88% for gamma pass-rate. The analysis of the out-of-control DQA helped identify a dosimetric error in our institute for a specific treatment type. We have defined initial tolerance criteria for DQA validations. We have shown that the implementation of a film-based patient-specific DQA protocol with the use of control charts is an effective method to improve patient treatment safety on CyberKnife. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  18. Foam-oil interaction in porous media: implications for foam assisted enhanced oil recovery.

    Science.gov (United States)

    Farajzadeh, R; Andrianov, A; Krastev, R; Hirasaki, G J; Rossen, W R

    2012-11-15

    The efficiency of a foam displacement process in enhanced oil recovery (EOR) depends largely on the stability of foam films in the presence of oil. Experimental studies have demonstrated the detrimental impact of oil on foam stability. This paper reviews the mechanisms and theories (disjoining pressure, coalescence and drainage, entering and spreading of oil, oil emulsification, pinch-off, etc.) suggested in the literature to explain the impact of oil on foam stability in the bulk and porous media. Moreover, we describe the existing approaches to foam modeling in porous media and the ways these models describe the oil effect on foam propagation in porous media. Further, we present various ideas on an improvement of foam stability and longevity in the presence of oil. The outstanding questions regarding foam-oil interactions and modeling of these interactions are pointed out. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Activated, coal-based carbon foam

    Science.gov (United States)

    Rogers, Darren Kenneth; Plucinski, Janusz Wladyslaw

    2004-12-21

    An ablation resistant, monolithic, activated, carbon foam produced by the activation of a coal-based carbon foam through the action of carbon dioxide, ozone or some similar oxidative agent that pits and/or partially oxidizes the carbon foam skeleton, thereby significantly increasing its overall surface area and concurrently increasing its filtering ability. Such activated carbon foams are suitable for application in virtually all areas where particulate or gel form activated carbon materials have been used. Such an activated carbon foam can be fabricated, i.e. sawed, machined and otherwise shaped to fit virtually any required filtering location by simple insertion and without the need for handling the "dirty" and friable particulate activated carbon foam materials of the prior art.

  20. The mechanical behavior of microcellular foams

    Energy Technology Data Exchange (ETDEWEB)

    Ozkul, M.H.; Mark, J.E. (Cincinnati Univ., OH (USA)); Aubert, J.H. (Sandia National Labs., Albuquerque, NM (USA))

    1990-01-01

    The mechanical behavior of microcellular open-cell foams prepared by a thermally induced phase separation process are investigated. The foams studied were prepared from isotactic polystyrene, polyacrylonitrile, and poly(4-methyl-1-pentene) (rigid foams), and polyurethane and Lycra (elastomeric foams). Their densities were in the range 0.04--0.27 g/cm3. Conventional polystyrene foams were used for comparison. The moduli and collapse stresses of these foams were measured in compression and compared with the current constitutive laws which relate mechanical properties to densities. A reinforcement technique based on the in-situ precipitation of silica was used to improve the mechanical properties. 13 refs., 4 figs., 3 tabs.

  1. Cellulose nanocrystals reinforced foamed nitrile rubber nanocomposites.

    Science.gov (United States)

    Chen, Yukun; Zhang, Yuanbing; Xu, Chuanhui; Cao, Xiaodong

    2015-10-05

    Research on foamed nitrile rubber (NBR)/cellulose nanocrystals (CNs) nanocomposites is rarely found in the literatures. In this paper, CNs suspension and NBR latex was mixed to prepared the foamed NBR/CNs nanocomposites. We found that the CNs mainly located in the cell walls, effectively reinforcing the foamed NBR. The strong interaction between the CNs and NBR matrix restricted the mobility of NBR chains surrounding the CNs, hence increasing the crosslink density of the NBR matrix. CNs exhibited excellent reinforcement on the foamed NBR: a remarkable increase nearly 76% in the tensile strength of the foamed nanocomposites was achieved with a load of only 15 phr CNs. Enhanced mechanical properties make the foamed NBR/CNs nanocomposites a promising damping material for industrial applications with a potential to reduce the petroleum consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Crosslinked polyethylene foams, via eb radiation

    International Nuclear Information System (INIS)

    Cardoso, E.C.L.; Lugao, A. B.; Andrade e Silva, L. G.

    1998-01-01

    Polyethylene foams, produced by radio-induced crosslinking, show a smooth and homogeneous surface, when compared to chemical crosslinking method using peroxide as crosslinking agent. This process fosters excellent adhesive and printability properties. Besides that, closed cells, intrinsic to these foams, imparts optimum mechanical, shocks and insulation resistance, indicating these foams to some markets segments as: automotive and transport; buoyancy, flotation and marine; building and insulation; packaging; domestic sports and leisure goods. We were in search of an ideal foam, by adding 5 to 15% of blowing agent in LDPE. A series of preliminary trials defined 203 degree sign C as the right blowing agent decomposition temperature. At a 22.7 kGys/dose ratio, the lowest dose for providing an efficient foam was 30 kGy, for a formulation comprising 10% of azodicarbonamide in LDPE, within a 10 minutes foaming time

  3. Nanostructured metal foams: synthesis and applications

    Energy Technology Data Exchange (ETDEWEB)

    Luther, Erik P [Los Alamos National Laboratory; Tappan, Bryce [Los Alamos National Laboratory; Mueller, Alex [Los Alamos National Laboratory; Mihaila, Bogdan [Los Alamos National Laboratory; Volz, Heather [Los Alamos National Laboratory; Cardenas, Andreas [Los Alamos National Laboratory; Papin, Pallas [Los Alamos National Laboratory; Veauthier, Jackie [Los Alamos National Laboratory; Stan, Marius [Los Alamos National Laboratory

    2009-01-01

    Fabrication of monolithic metallic nanoporous materials is difficult using conventional methodology. Here they report a relatively simple method of synthesizing monolithic, ultralow density, nanostructured metal foams utilizing self-propagating combustion synthesis of novel metal complexes containing high nitrogen energetic ligands. Nanostructured metal foams are formed in a post flame-front dynamic assembly with densities as low as 0.011 g/cc and surface areas as high as 270 m{sup 2}/g. They have produced metal foams via this method of titanium, iron, cobalt, nickel, zirconium, copper, palladium, silver, hafnium, platinum and gold. Microstructural features vary as a function of composition and process parameters. Applications for the metal foams are discussed including hydrogen absorption in palladium foams. A model for the sorption kinetics of hydrogen in the foams is presented.

  4. Foaming in manure based digesters: Effect of overloading and foam suppression using antifoam agents

    OpenAIRE

    Kougias, Panagiotis; Tsapekos, Panagiotis; Boe, Kanokwan; Angelidaki, Irini

    2013-01-01

    Anaerobic digestion foaming is one of the major problems that occasionally occur in full-scale biogas plants, affecting negatively the overall digestion process. The foam is typically created either in the main biogas reactor or/and in the pre-storage tank and the entrapped solids in the foam cause severe operational problems, such as blockage of mixing devices and collapse of pumps. Furthermore, the foaming problem is linked with economic consequences for biogas plants, due to income losses ...

  5. The Standard Days Method(®): efficacy, satisfaction and demand at regular family planning service delivery settings in Turkey.

    Science.gov (United States)

    Kursun, Zerrin; Cali, Sanda; Sakarya, Sibel

    2014-06-01

    To evaluate the demand, efficacy, and satisfaction concerning the Standard Days Method(®) (SDM; a fertility awareness method) as an option presented among other contraceptive methods at regular service delivery settings. The survey group consisted of 993 women who presented at the primary care units in Umraniye District of Istanbul, Turkey, between 1 October 2006 and 31 March 2008, and started to use a new method. Women were enrolled until reaching a limit of 250 new users for each method, or expiration of the six-month registration period. Participants were followed for up to one year of method use. The characteristics of women who chose the SDM were similar to those of participants who opted for other methods. The most common reasons for selecting it were that it is natural and causes no side effects. Fifty-one percent used the SDM for the full year, compared to 71% who chose an intrauterine device (IUD). Continuation rates were significantly lower for all other methods. During the one-year follow-up period, 12% of SDM-, 7% of pill-, 7% of condom-, 3% of monthly injection-, 1% of quarterly injection-, and 0.5% of IUD users became pregnant. The SDM had relatively high continuation rates and relatively good levels of satisfaction among participants and their husbands. It should be mentioned among the routinely offered contraceptive methods.

  6. Continuous Arc Rotation of the Couch Therapy for the Delivery of Accelerated Partial Breast Irradiation: A Treatment Planning Analysis

    International Nuclear Information System (INIS)

    Shaitelman, Simona F.; Kim, Leonard H.; Yan Di; Martinez, Alvaro A.; Vicini, Frank A.; Grills, Inga S.

    2011-01-01

    Purpose: We present a novel form of arc therapy: continuous arc rotation of the couch (C-ARC) and compare its dosimetry with three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and volumetric-modulated arc therapy (VMAT) for accelerated partial breast irradiation (APBI). C-ARC, like VMAT, uses a modulated beam aperture and dose rate, but with the couch, not the gantry, rotating. Methods and Materials: Twelve patients previously treated with APBI using 3D-CRT were replanned with (1) C-ARC, (2) IMRT, and (3) VMAT. C-ARC plans were designed with one medial and one lateral arc through which the couch rotated while the gantry was held stationary at a tangent angle. Target dose coverage was normalized to the 3D-CRT plan. Comparative endpoints were dose to normal breast tissue, lungs, and heart and monitor units prescribed. Results: Compared with 3D-CRT, C-ARC, IMRT, and VMAT all significantly reduced the ipsilateral breast V50% by the same amount (mean, 7.8%). Only C-ARC and IMRT plans significantly reduced the contralateral breast maximum dose, the ipsilateral lung V5Gy, and the heart V5%. C-ARC used on average 40%, 30%, and 10% fewer monitor units compared with 3D-CRT, IMRT, and VMAT, respectively. Conclusions: C-ARC provides improved dosimetry and treatment efficiency, which should reduce the risks of toxicity and secondary malignancy. Its tangent geometry avoids irradiation of critical structures that is unavoidable using the en face geometry of VMAT.

  7. Aqueous foam toxicology evaluation and hazard review

    Energy Technology Data Exchange (ETDEWEB)

    Archuleta, M.M.

    1995-10-01

    Aqueous foams are aggregates of bubbles mechanically generated by passing air or other gases through a net, screen, or other porous medium that is wetted by an aqueous solution of surface-active foaming agents (surfactants). Aqueous foams are important in modem fire-fighting technology, as well as for military uses for area denial and riot or crowd control. An aqueous foam is currently being developed and evaluated by Sandia National Laboratories (SNL) as a Less-Than-Lethal Weapon for the National Institute of Justice (NIJ). The purpose of this study is to evaluate the toxicity of the aqueous foam developed for the NIJ and to determine whether there are any significant adverse health effects associated with completely immersing individuals without protective equipment in the foam. The toxicity of the aqueous foam formulation developed for NIJ is determined by evaluating the toxicity of the individual components of the foam. The foam is made from a 2--5% solution of Steol CA-330 surfactant in water generated at expansion ratios ranging from 500:1 to 1000:1. SteoI CA-330 is a 35% ammonium laureth sulfate in water and is produced by Stepan Chemical Company and containing trace amounts (<0.1%) of 1,4-dioxane. The results of this study indicate that Steol CA-330 is a non-toxic, mildly irritating, surfactant that is used extensively in the cosmetics industry for hair care and bath products. Inhalation or dermal exposure to this material in aqueous foam is not expected to produce significant irritation or systemic toxicity to exposed individuals, even after prolonged exposure. The amount of 1,4-dioxane in the surfactant, and subsequently in the foam, is negligible and therefore, the toxicity associated with dioxane exposure is not significant. In general, immersion in similar aqueous foams has not resulted in acute, immediately life-threatening effects, or chronic, long-term, non-reversible effects following exposure.

  8. Sorption of heteropoly acids by polyurethane foam

    International Nuclear Information System (INIS)

    Dmitreinko, S.G.; Goncharova, L.V.; Runov, V.K.; Zakharov, V.N.; Aslanova, L.A.

    1997-01-01

    Sorption of oxidized and reduced forms of molybdosilicic, molybdophosphoric and molybdovanadophosphoric acids by polyurethane foam based on ethers and esters is studied. On the basis of sorption dependence on solution pH, polyurethane foam type and spectral characteristics of sorbates the suggestion has been made that in the polyurethane foam phase there are two main types of sorbent-sorbate interaction: electrostatic (ion-ion) and with hydrogen bond formation: and it is impossible to determine the contribution of every interaction

  9. FoAM Kernow Activity Report 2016

    OpenAIRE

    Griffiths, Amber; Griffiths, David

    2016-01-01

    This review shows selected projects from the FoAM Kernow studio in 2016. FoAM is a network of transdisciplinary labs at the intersection of art, science, nature and everyday life. FoAM’s members are generalists - people who work across disparate fields in an entangled, speculative culture. Research and creative projects at FoAM combine elements of futurecrafting, citizen science, prototyping, experience design and process facilitation to re-imagine possible futures, and artistic experime...

  10. FoAM Kernow Activity Report 2017

    OpenAIRE

    Griffiths, Amber; Weatherill, Aidan; Griffiths, David

    2017-01-01

    This review shows selected projects from the FoAM Kernow studio in 2017. FoAM is a network of transdisciplinary labs at the intersection of art, science, nature and everyday life. FoAM’s members are generalists - people who work across disparate fields in an entangled, speculative culture. Research and creative projects at FoAM combine elements of futurecrafting, citizen science, prototyping, experience design and process facilitation to re-imagine possible futures.

  11. B-Plant canyon fire foam supply

    International Nuclear Information System (INIS)

    Gainey, T.

    1995-01-01

    A new raw water supply was installed for the B-Plant fire foam system. This document details tests to be performed which will demonstrate that the system can function as designed. The tests include: Verification of the operation of the automatic valves at the cells; Measurement of water flow and pressure downstream of the proportioner; Production of foam, and measurement of foam concentration. Included as an appendix is a copy of the work package resolution (J4 ampersand J4a)

  12. System Acquires Data On Reactivities Of Foams

    Science.gov (United States)

    Walls, Joe T.

    1994-01-01

    Data-acquisition and -plotting system, called DAPS(TM), developed enabling accurate and objective determination of physical properties related to reactivities of polyurethane and polyisocyanurate foams. Automated, computer-controlled test apparatus that acquires data on rates of rise, rise profiles, exothermic temperatures, and internal pressures of foams prepared from both manual and machine-mixed batches. Data used to determine minute differences between reaction kinetics and exothermic profiles of foam formulations, properties of end products which are statistically undifferentiated.

  13. Monitoring foam coarsening using a computer optical mouse as a ...

    Indian Academy of Sciences (India)

    Keywords. Aqueous foam; optical flow sensor; dynamic laser speckle; computer optical mouse. ... Aqueous foams are colloidal systems with high concentration of gas bubbles in a liquid matrix. ... and complex behaviour of the foams. However ...

  14. Starch/fiber/poly(lactic acid) foam and compressed foam composites

    Science.gov (United States)

    Composites of starch, fiber, and poly(lactic acid) (PLA) were made using a foam substrate formed by dehydrating starch or starch/fiber gels. PLA was infiltrated into the dry foam to provide better moisture resistance. Foam composites were compressed into plastics using force ranging from 4-76MPa. Te...

  15. Effect of foam stirrer design on the catalytic performance of rotating foam stirrer reactions

    NARCIS (Netherlands)

    Leon Matheus, M.A.; Geers, P.; Nijhuis, T.A.; Schaaf, van der J.; Schouten, J.C.

    2012-01-01

    The liquid–solid mass transfer rate in a rotating foam stirrer reactor and in a slurry reactor is studied using the hydrogenation of styrene as a model reaction. The rotating foam stirrer reactor is a novel type of multi-phase reactor where highly open-celled materials, solid foams, are used as a

  16. Role of foam drainage in producing protein aggregates in foam fractionation.

    Science.gov (United States)

    Li, Rui; Zhang, Yuran; Chang, Yunkang; Wu, Zhaoliang; Wang, Yanji; Chen, Xiang'e; Wang, Tao

    2017-10-01

    It is essential to obtain a clear understanding of the foam-induced protein aggregation to reduce the loss of protein functionality in foam fractionation. The major effort of this work is to explore the roles of foam drainage in protein aggregation in the entire process of foam fractionation with bovine serum albumin (BSA) as a model protein. The results show that enhancing foam drainage increased the desorption of BSA molecules from the gas-liquid interface and the local concentration of desorbed molecules in foam. Therefore, it intensified the aggregation of BSA in foam fractionation. Simultaneously, it also accelerated the flow of BSA aggregates from rising foam into the residual solution along with the drained liquid. Because enhancing foam drainage increased the relative content of BSA molecules adsorbed at the gas-liquid interface, it also intensified the aggregation of BSA during both the defoaming process and the storage of the foamate. Furthermore, enhancing foam drainage more readily resulted in the formation of insoluble BSA aggregates. The results are highly important for a better understanding of foam-induced protein aggregation in foam fractionation. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Thermal performance enhancement of erythritol/carbon foam composites via surface modification of carbon foam

    Science.gov (United States)

    Li, Junfeng; Lu, Wu; Luo, Zhengping; Zeng, Yibing

    2017-03-01

    The thermal performance of the erythritol/carbon foam composites, including thermal diffusivity, thermal capacity, thermal conductivity and latent heat, were investigated via surface modification of carbon foam using hydrogen peroxide as oxider. It was found that the surface modification enhanced the wetting ability of carbon foam surface to the liquid erythritol of the carbon foam surface and promoted the increase of erythritol content in the erythritol/carbon foam composites. The dense interfaces were formed between erythritol and carbon foam, which is due to that the formation of oxygen functional groups C=O and C-OH on the carbon surface increased the surface polarity and reduced the interface resistance of carbon foam surface to the liquid erythritol. The latent heat of the erythritol/carbon foam composites increased from 202.0 to 217.2 J/g through surface modification of carbon foam. The thermal conductivity of the erythritol/carbon foam composite before and after surface modification further increased from 40.35 to 51.05 W/(m·K). The supercooling degree of erythritol also had a large decrease from 97 to 54 °C. Additionally, the simple and effective surface modification method of carbon foam provided an extendable way to enhance the thermal performances of the composites composed of carbon foams and PCMs.

  18. Decentralisation and health services delivery in Tanzania: Analysis of decision space in planning, allocation, and use of financial resources.

    Science.gov (United States)

    Kigume, Ramadhani; Maluka, Stephen; Kamuzora, Peter

    2018-04-01

    While decentralisation of health systems has been on the policy agenda in low-income and middle-income countries since the 1970s, many studies have focused on understanding who has more decision-making powers but less attention is paid to understand what those powers encompass. Using the decision space approach, this study aimed to understand the amount of decision-making space transferred from the central government to institutions at the periphery in the decentralised health system in Tanzania. The findings of this study indicated that the decentralisation process in Tanzania has provided authorities with a range of decision-making space. In the areas of priority setting and planning, district health authorities had moderate decision space. However, in the financial resource allocation and expenditure of funds from the central government, the districts had narrow decision-making space. The districts, nevertheless, had wider decision-making space in mobilising and using locally generated financial resources. However, the ability of the districts to allocate and use locally generated resources was constrained by bureaucratic procedures of the central government. The study concludes that decentralisation by devolution which is being promoted in the policy documents in Tanzania is yet to be realised at the district and local levels. The study recommends that the central government should provide more space to the decentralised district health systems to incorporate locally defined priorities in the district health plans. Copyright © 2018 John Wiley & Sons, Ltd.

  19. Defect generation during solidification of aluminium foams

    International Nuclear Information System (INIS)

    Mukherjee, M.; Garcia-Moreno, F.; Banhart, J.

    2010-01-01

    The reason for the frequent occurrence of cell wall defects in metal foams was investigated. Aluminium foams often expand during solidification, a process which is referred as solidification expansion (SE). The effect of SE on the structure of aluminium foams was studied in situ by X-ray radioscopy and ex situ by X-ray tomography. A direct correlation between the magnitude of SE and the number of cell wall ruptures during SE and finally the number of defects in the solidified foams was found.

  20. New Spin Foam Models of Quantum Gravity

    Science.gov (United States)

    Miković, A.

    We give a brief and a critical review of the Barret-Crane spin foam models of quantum gravity. Then we describe two new spin foam models which are obtained by direct quantization of General Relativity and do not have some of the drawbacks of the Barret-Crane models. These are the model of spin foam invariants for the embedded spin networks in loop quantum gravity and the spin foam model based on the integration of the tetrads in the path integral for the Palatini action.

  1. AC induction field heating of graphite foam

    Science.gov (United States)

    Klett, James W.; Rios, Orlando; Kisner, Roger

    2017-08-22

    A magneto-energy apparatus includes an electromagnetic field source for generating a time-varying electromagnetic field. A graphite foam conductor is disposed within the electromagnetic field. The graphite foam when exposed to the time-varying electromagnetic field conducts an induced electric current, the electric current heating the graphite foam. An energy conversion device utilizes heat energy from the heated graphite foam to perform a heat energy consuming function. A device for heating a fluid and a method of converting energy are also disclosed.

  2. Foam-like structure of the Universe

    International Nuclear Information System (INIS)

    Kirillov, A.A.; Turaev, D.

    2007-01-01

    On the quantum stage space-time had the foam-like structure. When the Universe cools, the foam structure tempers and does not disappear. We show that effects caused by the foamed structure mimic very well the observed Dark Matter phenomena. Moreover, we show that in a foamed space photons undergo a chaotic scattering and together with every discrete source of radiation we should observe a diffuse halo. We show that the distribution of the diffuse halo of radiation around a point-like source repeats exactly the distribution of dark matter around the same source, i.e., the DM halos are sources of the diffuse radiation

  3. Foam-like structure of the Universe

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov, A.A. [Institute for Applied Mathematics and Cybernetics, 10 Ulyanova str., Nizhny Novgorod 603005 (Russian Federation)], E-mail: ka98@mail.ru; Turaev, D. [Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105 (Israel)

    2007-11-15

    On the quantum stage space-time had the foam-like structure. When the Universe cools, the foam structure tempers and does not disappear. We show that effects caused by the foamed structure mimic very well the observed Dark Matter phenomena. Moreover, we show that in a foamed space photons undergo a chaotic scattering and together with every discrete source of radiation we should observe a diffuse halo. We show that the distribution of the diffuse halo of radiation around a point-like source repeats exactly the distribution of dark matter around the same source, i.e., the DM halos are sources of the diffuse radiation.

  4. Controlling of density uniformity of polyacrylate foams

    International Nuclear Information System (INIS)

    Shan Wenwen; Yuan Baohe; Wang Yanhong; Xu Jiayun; Zhang Lin

    2010-01-01

    The density non-uniformity existing in most low-density foams will affect performance of the foams. The trimethylolpropane trimethacrylate (TMPTA) foam targets were prepared and controlling methods of the foams, density uniformity were explored together with its forming mechanism. It has been found that the UV-light with high intensity can improve the distribution uniformity of the free radicals induced by UV photons in the solvents, thus improve the density uniformity of the foams. In addition, container wall would influence the concentration distribution of the solution, which affects the density uniformity of the foams. Thus, the UV-light with high intensity was chosen together with polytetrafluoroethylene molds instead of glass molds to prepare the foams with the density non-uniformity less than 10%. β-ray detection technology was used to measure the density uniformity of the TMPTA foams with the density in the range of 10 to 100 mg · cm -3 , and the results show that the lower the foam density is, the worse the density uniformity is. (authors)

  5. Faraday instability at foam-water interface.

    Science.gov (United States)

    Bronfort, A; Caps, H

    2012-12-01

    A nearly two-dimensional foam is generated inside a Hele-shaw cell and left at rest on its liquid bath. The system is then vertically shaken and, above a well-defined acceleration threshold, surface waves appear at the foam-liquid interface. Those waves are shown to be subharmonic. The acceleration threshold is studied and compared to the common liquid-gas case, emphasizing the energy dissipation inside the foam. An empirical model is proposed for this energy loss, accounting for the foam characteristics such as the bubble size but also the excitation parameter, namely the linear velocity.

  6. Utilization of health care services in rural and urban areas: a determinant factor in planning and managing health care delivery systems.

    Science.gov (United States)

    Oladipo, Jimoh Ayanda

    2014-06-01

    Disparities in use of healthcare services between rural and urban areas have been empirically attributed to several factors. This study explores the existence of this disparity and its implication for planning and managing healthcare delivery systems. The objectives determine the relative importance of the various predisposing, enabling, need and health services factors on utilization of health services; similarity between rural and urban areas; and major explanatory variables for utilization. A four-stage model of service utilization was constructed with 31 variables under appropriate model components. Data is collected using cross-sectional sample survey of 1086 potential health services consumers in selected health facilities and resident milieu via questionnaire. Data is analyzed using factor analysis and cross tabulation. The 4-stage model is validated for the aggregate data and data for the rural areas with 3-stage model for urban areas. The order of importance of the factors is need, enabling, predisposing and health services. 11 variables are found to be powerful predictors of utilization. Planning of different categories of health care facilities in different locations should be based on utilization rates while proper management of established facilities should aim to improve health seeking behavior of people.

  7. State-of-the-Art Review on the Characteristics of Surfactants and Foam from Foam Concrete Perspective

    Science.gov (United States)

    Sahu, Sritam Swapnadarshi; Gandhi, Indu Siva Ranjani; Khwairakpam, Selija

    2018-06-01

    Foam concrete finds application in many areas, generally as a function of its relatively lightweight and its beneficial properties in terms of reduction in dead load on structure, excellent thermal insulation and contribution to energy conservation. For production of foam concrete with desired properties, stable and good quality foam is the key requirement. It is to be noted that the selection of surfactant and foam production parameters play a vital role in the properties of foam which in turn affects the properties of foam concrete. However, the literature available on the influence of characteristics of foaming agent and foam on the properties of foam concrete are rather limited. Hence, a more systematic research is needed in this direction. The focus of this work is to provide a review on characteristics of surfactant (foaming agent) and foam for use in foam concrete production.

  8. Fertility desires and unmet need for family planning among HIV infected individuals in two HIV clinics with differing models of family planning service delivery.

    Science.gov (United States)

    Wanyenze, Rhoda K; Matovu, Joseph K B; Kamya, Moses R; Tumwesigye, Nazarius M; Nannyonga, Maria; Wagner, Glenn J

    2015-01-28

    Eliminating family planning (FP) unmet need among HIV-infected individuals (PLHIV) is critical to elimination of mother-to-child HIV transmission. We assessed FP unmet need among PLHIV attending two clinics with differing models of FP services. Nsambya Home Care provided only FP information while Mulago HIV clinic provided information and contraceptives onsite. In a cross-sectional study conducted between February-June 2011, we documented pregnancies, fertility desires, and contraceptive use among 797 HIV-infected men and women (408 in Mulago and 389 in Nsambya). FP unmet need was calculated among women who were married, unmarried but had sex within the past month, did not desire the last or future pregnancy at all or wished to postpone for ≥ two years and were not using contraceptives. Multivariable analyses for correlates of FP unmet need were computed for each clinic. Overall, 40% (315) had been pregnant since HIV diagnosis; 58% desired the pregnancies. Of those who were not pregnant, 49% (366) did not desire more children at all; 15.7% wanted children then and 35.3% later. The unmet need for FP in Nsambya (45.1%) was significantly higher than that in Mulago at 30.9% (p = 0.008). Age 40+ compared to 18-29 years (OR = 6.05; 95% CI: 1.69, 21.62 in Mulago and OR = 0.21; 95% CI: 0.05, 0.90 in Nsambya), other Christian denominations (Pentecostal and Seventh Day Adventists) compared to Catholics (OR = 7.18; 95% CI: 2.14, 24.13 in Mulago and OR = 0.23; 95% CI: 0.06, 0.80 in Nsambya), and monthly expenditure > USD 200 compared to fertility support and elimination of FP unmet need among PLHIV, even with integration of FP information and supplies into HIV clinics.

  9. New decontamination process using foams containing particles

    International Nuclear Information System (INIS)

    Guignot, S.; Faure, S.

    2008-01-01

    One key point in the dismantling of nuclear facilities is the thorough cleaning of radiation- exposed surfaces on which radioactive deposits have formed. This cleaning step is often achieved by successive liquid rinses with specific solutions containing alkaline, acidic, or even oxidizing species depending on whether the aim is to dissolve greasy deposits (like ter-butylphosphate) or to corrode surfaces on micrometric thicknesses. An alternative process to reduce the amount of chemicals and the volume of the resulting nuclear wastes consists in using the same but foamed solutions (1). Carrying less liquid, the resulting foams still display similar kinetics of dissolution rates and their efficiency is determined by their ability to hold sufficient wetnesses during the time required for the decontamination. Classical foam decontamination process illustrated by foam pulverization or circulation in the 90 turned five years ago into a specific static process using high-lifetime viscosified foam at a steady state. One way to slow down the liquid drainage is to raise liquid viscosity by adding organic viscosifiers like xanthan gum (2). In 2005, new studies started on an innovative process proposed by S. Faure and based on triphasic foams containing particles [3]. The aim is to generate new decontamination foams containing less quantities of organics materials (surfactants and viscosifiers). Silica particles are obviously known to stabilize or destabilize foams (4). In the frame of S. Guignot Ph.D., new fundamental studies are initiated in order to clarify the role of silica solid microparticles in these foams. Our final goal is to determine whether this kind of new foam can be stable for several hours for a decontamination process. The results we will report focus on wet foams used for nuclear decontamination and incorporating fumed silica. The study is conducted on a vertical foam column in a pseudo-free drainage configuration, and aims at investigating the influence of

  10. A treatment planning and delivery comparison of volumetric modulated arc therapy with or without flattening filter for gliomas, brain metastases, prostate, head/neck and early stage lung cancer

    DEFF Research Database (Denmark)

    Gasic, Daniel; Ohlhues, Lars; Brodin, N. Patrik

    2014-01-01

    generated using STD- and FFF-VMAT for both 6 MV and 10 MV, and were compared with respect to plan quality, monitor units and delivery time using Wilcoxon signed rank tests. RESULTS: For H&N and high-grade gliomas, there was a significant difference in homogeneity index in favor for STD-VMAT (p

  11. Analysis of Influence of Foaming Mixture Components on Structure and Properties of Foam Glass

    Science.gov (United States)

    Karandashova, N. S.; Goltsman, B. M.; Yatsenko, E. A.

    2017-11-01

    It is recommended to use high-quality thermal insulation materials to increase the energy efficiency of buildings. One of the best thermal insulation materials is foam glass - durable, porous material that is resistant to almost any effect of substance. Glass foaming is a complex process depending on the foaming mode and the initial mixture composition. This paper discusses the influence of all components of the mixture - glass powder, foaming agent, enveloping material and water - on the foam glass structure. It was determined that glass powder is the basis of the future material. A foaming agent forms a gas phase in the process of thermal decomposition. This aforementioned gas foams the viscous glass mass. The unreacted residue thus changes a colour of the material. The enveloping agent slows the foaming agent decomposition preventing its premature burning out and, in addition, helps to accelerate the sintering of glass particles. The introduction of water reduces the viscosity of the foaming mixture making it evenly distributed and also promotes the formation of water gas that additionally foams the glass mass. The optimal composition for producing the foam glass with the density of 150 kg/m3 is defined according to the results of the research.

  12. dsmcFoam+: An OpenFOAM based direct simulation Monte Carlo solver

    Science.gov (United States)

    White, C.; Borg, M. K.; Scanlon, T. J.; Longshaw, S. M.; John, B.; Emerson, D. R.; Reese, J. M.

    2018-03-01

    dsmcFoam+ is a direct simulation Monte Carlo (DSMC) solver for rarefied gas dynamics, implemented within the OpenFOAM software framework, and parallelised with MPI. It is open-source and released under the GNU General Public License in a publicly available software repository that includes detailed documentation and tutorial DSMC gas flow cases. This release of the code includes many features not found in standard dsmcFoam, such as molecular vibrational and electronic energy modes, chemical reactions, and subsonic pressure boundary conditions. Since dsmcFoam+ is designed entirely within OpenFOAM's C++ object-oriented framework, it benefits from a number of key features: the code emphasises extensibility and flexibility so it is aimed first and foremost as a research tool for DSMC, allowing new models and test cases to be developed and tested rapidly. All DSMC cases are as straightforward as setting up any standard OpenFOAM case, as dsmcFoam+ relies upon the standard OpenFOAM dictionary based directory structure. This ensures that useful pre- and post-processing capabilities provided by OpenFOAM remain available even though the fully Lagrangian nature of a DSMC simulation is not typical of most OpenFOAM applications. We show that dsmcFoam+ compares well to other well-known DSMC codes and to analytical solutions in terms of benchmark results.

  13. Self-fitting shape memory polymer foam inducing bone regeneration: A rabbit femoral defect study.

    Science.gov (United States)

    Xie, Ruiqi; Hu, Jinlian; Hoffmann, Oskar; Zhang, Yuanchi; Ng, Frankie; Qin, Tingwu; Guo, Xia

    2018-04-01

    Although tissue engineering has been attracted greatly for healing of critical-sized bone defects, great efforts for improvement are still being made in scaffold design. In particular, bone regeneration would be enhanced if a scaffold precisely matches the contour of bone defects, especially if it could be implanted into the human body conveniently and safely. In this study, polyurethane/hydroxyapatite-based shape memory polymer (SMP) foam was fabricated as a scaffold substrate to facilitate bone regeneration. The minimally invasive delivery and the self-fitting behavior of the SMP foam were systematically evaluated to demonstrate its feasibility in the treatment of bone defects in vivo. Results showed that the SMP foam could be conveniently implanted into bone defects with a compact shape. Subsequently, it self-matched the boundary of bone defects upon shape-recovery activation in vivo. Micro-computed tomography determined that bone ingrowth initiated at the periphery of the SMP foam with a constant decrease towards the inside. Successful vascularization and bone remodeling were also demonstrated by histological analysis. Thus, our results indicate that the SMP foam demonstrated great potential for bone regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Preparation of three-dimensional shaped aluminum alloy foam by two-step foaming

    International Nuclear Information System (INIS)

    Shang, J.T.; Xuming, Chu; Deping, He

    2008-01-01

    A novel method, named two-step foaming, was investigated to prepare three-dimensional shaped aluminum alloy foam used in car industry, spaceflight, packaging and related areas. Calculations of thermal decomposition kinetics of titanium hydride showed that there is a considerable amount of hydrogen releasing when the titanium hydride is heated at a relatively high temperature after heated at a lower temperature. The hydrogen mass to sustain aluminum alloy foam, having a high porosity, was also estimated by calculations. Calculations indicated that as-received titanium hydride without any pre-treatment can be used as foaming agents in two-step foaming. The processes of two-step foaming, including preparing precursors and baking, were also studied by experiments. Results showed that, low titanium hydride dispersion temperature, long titanium hydride dispersion time and low precursors porosity are beneficial to prepare three-dimensional shaped aluminum alloy foams with uniform pores

  15. Delivery presentations

    Science.gov (United States)

    Pregnancy - delivery presentation; Labor - delivery presentation; Occiput posterior; Occiput anterior; Brow presentation ... The mother can walk, rock, and try different delivery positions during labor to help encourage the baby ...

  16. A Method to Produce Foam Glasses

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to a production process of foam glass from a mixture of glass cullet or slag or fly ash with a foaming agent and an oxidizing agent and heating to below 1100 C under low oxygen atmosphere. The invention relates more particularly to a process wherein pure carbon or a ...

  17. Anti-foam System design description

    International Nuclear Information System (INIS)

    White, M.A.

    1994-01-01

    The Anti-foam System is a sub-system of the 242-A Evaporator facility. The Anti-foam is used within the C-A-1 Vapor-Liquid Separator, to reduce the effect of foaming and reduce fluid bumping while the vapor and liquid are separated within the C-A-1 Vapor-Liquid Separator. Excessive foaming within the vessel may possibly cause the liquid slurry mixture in the evaporator vessel to foul the de-entrainment pads and cause plant shutdown. The Anti-foam System consists of the following primary elements: the Anti-foam Tank and the Metering Pump. The upgrades to Anti-foam System include the following: installation of a new pump, instruments, and valves; and connection of the instruments, pump and agitator associated with the Anti-foam System to the Monitoring and Control System (MCS). The 242-A Evaporator is a waste treatment facility designed to reduce liquid waste volumes currently stored in the Hanford Area double shell Waste Storage Tanks. The evaporator uses evaporative concentration to achieve this volume reduction, returning the concentrated slurry to the double-shell tanks for storage and, at the same time, releasing the process effluent to a retention facilities for eventual treatment and release to the environment

  18. Application of Auxetic Foam in Sports Helmets

    Directory of Open Access Journals (Sweden)

    Leon Foster

    2018-03-01

    Full Text Available This investigation explored the viability of using open cell polyurethane auxetic foams to augment the conformable layer in a sports helmet and improve its linear impact acceleration attenuation. Foam types were compared by examining the impact severity on an instrumented anthropomorphic headform within a helmet consisting of three layers: a rigid shell, a stiff closed cell foam, and an open cell foam as a conformable layer. Auxetic and conventional foams were interchanged to act as the helmet’s conformable component. Attenuation of linear acceleration was examined by dropping the combined helmet and headform on the front and the side. The helmet with auxetic foam reduced peak linear accelerations (p < 0.05 relative to its conventional counterpart at the highest impact energy in both orientations. Gadd Severity Index reduced by 11% for frontal impacts (38.9 J and 44% for side impacts (24.3 J. The conformable layer within a helmet can influence the overall impact attenuating properties. The helmet fitted with auxetic foam can attenuate impact severity more than when fitted with conventional foam, and warrants further investigation for its potential to reduce the risk of traumatic brain injuries in sport specific impacts.

  19. Foam is a decon waste minimization tool

    International Nuclear Information System (INIS)

    Peterson, K.D.; McGlynn, J.F.; Rankin, W.N.

    1991-01-01

    The use of foam in decontamination operations offers significant reductions in waste generation. Initial use has confirmed its effectiveness. Issues being resolved at Savannah River Site (SRS) include compatibility of foam generating solutions with decontamination solutions, waste disposal, and operational safety

  20. Industrial waste utilization for foam concrete

    Science.gov (United States)

    Krishnan, Gokul; Anand, K. B.

    2018-02-01

    Foam concrete is an emerging and useful construction material - basically a cement based slurry with at least 10% of mix volume as foam. The mix usually containing cement, filler (usually sand) and foam, have fresh densities ranging from 400kg/m3 to 1600kg/m3. One of the main drawbacks of foam concrete is the large consumption of fine sand as filler material. Usage of different solid industrial wastes as fillers in foam concrete can reduce the usage of fine river sand significantly and make the work economic and eco-friendly. This paper aims to investigate to what extent industrial wastes such as bottom ash and quarry dust can be utilized for making foam concrete. Foam generated using protein based agent was used for preparing and optimizing (fresh state properties). Investigation to find the influence of design density and air-void characteristics on the foam concrete strength shows higher strength for bottom ash mixes due to finer air void distribution. Setting characteristics of various mix compositions are also studied and adoption of Class C flyash as filler demonstrated capability of faster setting.

  1. Damping of liquid sloshing by foams

    Science.gov (United States)

    Sauret, A.; Boulogne, F.; Cappello, J.; Dressaire, E.; Stone, H. A.

    2015-02-01

    When a container is set in motion, the free surface of the liquid starts to oscillate or slosh. Such effects can be observed when a glass of water is handled carelessly and the fluid sloshes or even spills over the rims of the container. However, beer does not slosh as readily as water, which suggests that foam could be used to damp sloshing. In this work, we study experimentally the effect on sloshing of a liquid foam placed on top of a liquid bath. We generate a monodisperse two-dimensional liquid foam in a rectangular container and track the motion of the foam. The influence of the foam on the sloshing dynamics is experimentally characterized: only a few layers of bubbles are sufficient to significantly damp the oscillations. We rationalize our experimental findings with a model that describes the foam contribution to the damping coefficient through viscous dissipation on the walls of the container. Then we extend our study to confined three-dimensional liquid foam and observe that the behavior of 2D and confined 3D systems are very similar. Thus, we conclude that only the bubbles close to the walls have a significant impact on the dissipation of energy. The possibility to damp liquid sloshing using foam is promising in numerous industrial applications such as the transport of liquefied gas in tankers or for propellants in rocket engines.

  2. Moving towards precision orthodontics: An evolving paradigm shift in the planning and delivery of customized orthodontic therapy.

    Science.gov (United States)

    Jheon, A H; Oberoi, S; Solem, R C; Kapila, S

    2017-06-01

    Advances in precision medicine portend similar progress in orthodontics and will be increasingly harnessed to achieve customized treatment approaches and enhance treatment efficiencies. Our goal is to provide a background on emerging advances in computer technologies and biomedicine and highlight their current and likely future applications to precision orthodontics. A review of orthodontically relevant technologies and advances in pertinent biological research was undertaken. Innovations in computer hardware and software, and 3D imaging technologies offer the ability for customized treatment and biomechanical planning that will be more fully realized within the next few decades. These technologies combined with 3D printing are already being applied to customized appliance fabrication such as aligners and retainers. The future prospects for custom fabrication of orthodontic brackets of appropriate material properties and smart devices are highly desirable and compelling goals. Within biomedicine, the fundamental understanding of cartilage growth and bone biology is currently being tested in animal models to modify mandibular growth and modulate tooth movement, respectively. Some of these discoveries will ultimately have clinical applications in orthodontics including for growth modification, accelerating orthodontic tooth movement, and enhancing anchorage or retention of teeth. Additional genomic and proteomic information will add to further customization of orthodontic diagnosis and treatments. Over the coming decades, precision orthodontics will continue to benefit from advances in many fields and will require the integration of advances in technology, and biomedical and clinical research to deliver optimal, efficient, safe, and reproducible personalized orthodontic treatment. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Low-density carbonized resorcinol-formaldehyde foams

    International Nuclear Information System (INIS)

    Kong, F.M.; Buckley, S.R.; Giles, C.L. Jr.; Haendler, B.L.; Hair, L.M.; Letts, S.A.; Overturf, G.E. III; Price, C.W.; Cook, R.C.

    1991-01-01

    This report documents research and development on resorcinol- formaldehyde-based foam materials conducted between 1986 and June 1990, when the effort was discontinued. The foams discussed are resorcinol-formaldehyde (RF) foam, carbonized RF (CRF) foam, and two composite foams, a polystyrene/RF (PS/RF) foam and its carbonized derivative (CPR). The RF foams are synthesized by the polycondensation of resorcinol with formaldehyde in a slightly basic solution. Their structure and density depend strongly on the concentration of the sodium carbonate catalyst. The have an interconnected bead structure similar to that of silica aerogels; bead sizes range from 30 to 130 Angstrom, and cell sizes are less than 0.1 μm. We have achieved densities of 16 to 200 mg/cm 3 . The RF foams can be pyrolyzed in an inert atmosphere to form a vitreous carbon foam (CRF), which has a similar microstructure but much higher mechanical strength. The PS/RF foams are obtained by filling the 2- to 3-μm cells of PS foam (a low-density hydrocarbon foam we have developed) with RF. The resultant foams have the outstanding handling and machinability of the PS foam matrix and the small cell size of RF. Pyrolyzing PS/RF foams causes depolymerization and loss of the PS; the resulting CPR foams have a structure similar to the PS foams in which CRF both replicates and fills the PS cells

  4. SU-F-J-71: Improving CT Quality for Radiation Therapy Planning and Delivery Guidance Using a Non-Linear Contrast Enhancement Technique

    Energy Technology Data Exchange (ETDEWEB)

    Noid, G; Tai, A; Li, X [Medical College of Wisconsin, Milwaukee, WI (United States)

    2016-06-15

    Purpose: Advanced image post-processing techniques which enhance soft-tissue contrast in CT have not been widely employed for RT planning or delivery guidance. The purpose of this work is to assess the soft-tissue contrast enhancement from non-linear contrast enhancing filters and its impact in RT. The contrast enhancement reduces patient alignment uncertainties. Methods: Non-linear contrast enhancing methods, such as Best Contrast (Siemens), amplify small differences in X-ray attenuation between two adjacent structure without significantly increasing noise. Best Contrast (BC) separates a CT into two frequency bands. The low frequency band is modified by a non-linear scaling function before recombination with the high frequency band. CT data collected using a CT-on-rails (Definition AS Open, Siemens) during daily CT-guided RT for 6 prostate cancer patients and an image quality phantom (The Phantom Laboratory) were analyzed. Images acquired with a standard protocol (120 kVp, 0.6 pitch, 18 mGy CTDIvol) were processed before comparison to the unaltered images. Contrast and noise were measured in the the phantom. Inter-observer variation was assessed by placing prostate contours on the 12 CT study sets, 6 enhanced and 6 unaltered, in a blinded study involving 8 observers. Results: The phantom data demonstrate that BC increased the contrast between the 1.0% supra-slice element and the background substrate by 46.5 HU while noise increased by only 2.3 HU. Thus the contrast to noise ratio increased from 1.28 to 6.71. Furthermore, the variation in centroid position of the prostate contours was decreased from 1.3±0.4 mm to 0.8±0.3 mm. Thus the CTV-to-PTV margin was reduced by 1.1 mm. The uncertainty in delineation of the prostate/rectum edge decreased by 0.5 mm. Conclusion: As demonstrated in phantom and patient scans the BC filter accentuates soft-tissue contrast. This enhancement leads to reduced inter-observer variation, which should improve RT planning and delivery

  5. Foam generator and viscometer apparatus and process

    Science.gov (United States)

    Reed, Troy D.; Pickell, Mark B.; Volk, Leonard J.

    2004-10-26

    An apparatus and process to generate a liquid-gas-surfactant foam and to measure its viscosity and enable optical and or electronic measurements of physical properties. The process includes the steps of pumping selected and measured liquids and measured gases into a mixing cell. The mixing cell is pressurized to a desired pressure and maintained at a desired pressure. Liquids and gas are mixed in the mixing cell to produce a foam of desired consistency. The temperature of the foam in the mixing cell is controlled. Foam is delivered from the mixing cell through a viscometer under controlled pressure and temperature conditions where the viscous and physical properties of the foam are measured and observed.

  6. Oxidation behaviour of metallic glass foams

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, B.R. [Department of Materials Science and Engineering, 434 Dougherty Hall, University of Tennessee, Knoxville, TN 37996-2200 (United States)], E-mail: bbarnard@utk.edu; Liaw, P.K. [Department of Materials Science and Engineering, 434 Dougherty Hall, University of Tennessee, Knoxville, TN 37996-2200 (United States); Demetriou, M.D.; Johnson, W.L. [Department of Materials Science, Keck Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

    2008-08-15

    In this study, the effects of porosity on the oxidation behaviour of bulk-metallic glasses were investigated. Porous Pd- and Fe-based bulk-metallic glass (BMG) foams and Metglas ribbons were studied. Oxidizing experiments were conducted at 70 deg. C, and around 80 deg. C below glass-transition temperatures, (T{sub g}s). Scanning-electron microscopy/energy-dispersive spectroscopy (SEM/EDS) studies revealed little evidence of oxidation at 70 deg. C. Specimens exhibited greater oxidation at T{sub g} - 80 deg. C. Oxides were copper-based for Pd-based foams, Fe-, Cr-, and Mo-based for Fe-based foams, and Co-based with borosilicates likely for the Metglas. Pd-based foams demonstrated the best oxidation resistance, followed by Metglas ribbons, followed by Fe-based foams.

  7. Treatment planning and delivery of involved field radiotherapy in advanced Hodgkin's disease: results from a questionnaire-based audit for the UK Stanford V regimen vs ABVD clinical trial quality assurance programme (ISRCTN 64141244).

    Science.gov (United States)

    Diez, P; Hoskin, P J; Aird, E G A

    2007-10-01

    This questionnaire forms the basis of the quality assurance (QA) programme for the UK randomized Phase III study of the Stanford V regimen versus ABVD for treatment of advanced Hodgkin's disease to assess differences between participating centres in treatment planning and delivery of involved-field radiotherapy for Hodgkin's lymphoma The questionnaire, which was circulated amongst 42 participating centres, consisted of seven sections: target volume definition and dose prescription; critical structures; patient positioning and irradiation techniques; planning; dose calculation; verification; and future developments The results are based on 25 responses. One-third plan using CT alone, one-third use solely the simulator and the rest individualize, depending on disease site. Eleven centres determine a dose distribution for each patient. Technique depends on disease site and whether CT or simulator planning is employed. Most departments apply isocentric techniques and use immobilization and customized shielding. In vivo dosimetry is performed in 7 centres and treatment verification occurs in 24 hospitals. In conclusion, the planning and delivery of treatment for lymphoma patients varies across the country. Conventional planning is still widespread but most centres are moving to CT-based planning and virtual simulation with extended use of immobilization, customized shielding and compensation.

  8. Polymer microcapsules with "foamed" membranes.

    Science.gov (United States)

    Lavergne, Fleur-Marie; Cot, Didier; Ganachaud, François

    2007-06-05

    This article describes the preparation of capsules displaying craters at their surfaces and independent holes inside their membranes. These poly(methylmethacrylate) capsules of 20 to 200 microm diameter are prepared by a solvent evaporation process and typically contain a dispersant, polyvinyl alcohol, and an excipient, namely, a fatty acid triglyceride (miglyol 812). Spectroscopic methods showed that, depending on the miglyol content, the craters at the surface exhibited sizes of about 1 to 2 microm, whereas the core structure of the membrane changed significantly, typically from "soft-part-of-bread" up to "foamed"-like aspects. Among several spectroscopy techniques, confocal fluorescence microscopy confirmed that the capsules retained the miglyol in their core and not in the craters or holes, even after centrifugation and handling. This technique also showed that holes in the membrane are filled with water. A possible analysis of the "foaming" phenomenon based on the surface tensions of different oils, as well as their optimal hydrophile-lipophile balance (HLBO), is added to generalize the concept.

  9. Carbon particle induced foaming of molten sucrose for the preparation of carbon foams

    International Nuclear Information System (INIS)

    Narasimman, R.; Vijayan, Sujith; Prabhakaran, K.

    2014-01-01

    Graphical abstract: - Highlights: • An easy method for the preparation of carbon foam from sucrose is presented. • Wood derived activated carbon particles are used to stabilize the molten sucrose foam. • The carbon foams show relatively good mechanical strength. • The carbon foams show excellent CO 2 adsorption and oil absorption properties. • The process could be scaled up for the preparation of large foam bodies. - Abstract: Activated carbon powder was used as a foaming and foam setting agent for the preparation of carbon foams with a hierarchical pore structure from molten sucrose. The rheological measurements revealed the interruption of intermolecular hydrogen bonding in molten sucrose by the carbon particles. The carbon particles stabilized the bubbles in molten sucrose by adsorbing on the molten sucrose–gas interface. The carbon foams obtained at the activated carbon powder to sucrose weight ratios in the range of 0–0.25 had a compressive strength in the range of 1.35–0.31 MPa. The produced carbon foams adsorb 2.59–3.04 mmol/g of CO 2 at 760 mmHg at 273 K and absorb oil from oil–water mixtures and surfactant stabilized oil-in-water emulsions with very good selectivity and recyclability

  10. Foam pad of appropriate thickness can improve diagnostic value of foam posturography in detecting postural instability.

    Science.gov (United States)

    Liu, Bo; Leng, Yangming; Zhou, Renhong; Liu, Jingjing; Liu, Dongdong; Liu, Jia; Zhang, Su-Lin; Kong, Wei-Jia

    2018-04-01

    The present study investigated the effect of foam thickness on postural stability in patients with unilateral vestibular hypofunction (UVH) during foam posturography. Static and foam posturography were performed in 33 patients (UVH group) and 30 healthy subjects (control group) with eyes open (EO) and closed (EC) on firm surface and on 1-5 foam pad(s). Sway velocity (SV) of center of pressure, standing time before falling (STBF) and falls reaction were recorded and analyzed. (1) SVs had an increasing tendency in both groups as the foam pads were added under EO and EC conditions. (2) STBFs, only in UVH group with EC, decreased with foam thickness increasing. (3) Significant differences in SV were found between the control and UVH group with EO (except for standing on firm surface, on 1 and 2 foam pad(s)) and with EC (all surface conditions). (4) Receiver operating characteristic curve analysis showed that the SV could better reflect the difference in postural stability between the two groups while standing on the 4 foam pads with EC. Our study showed that diagnostic value of foam posturography in detecting postural instability might be enhanced by using foam pad of right thickness.

  11. Generation of sclerosant foams by mechanical methods increases the foam temperature.

    Science.gov (United States)

    Tan, Lulu; Wong, Kaichung; Connor, David; Fakhim, Babak; Behnia, Masud; Parsi, Kurosh

    2017-08-01

    Objective To investigate the effect of agitation on foam temperature. Methods Sodium tetradecyl sulphate and polidocanol were used. Prior to foam generation, the sclerosant and all constituent equipment were cooled to 4-25℃ and compared with cooling the sclerosant only. Foam was generated using a modified Tessari method. During foam agitation, the temperature change was measured using a thermocouple for 120 s. Results Pre-cooling all the constituent equipment resulted in a cooler foam in comparison with only cooling the sclerosant. A starting temperature of 4℃ produced average foam temperatures of 12.5 and 13.2℃ for sodium tetradecyl sulphate and polidocanol, respectively. It was also found that only cooling the liquid sclerosant provided minimal cooling to the final foam temperature, with the temperature 20 and 20.5℃ for sodium tetradecyl sulphate and polidocanol, respectively. Conclusion The foam generation process has a noticeable impact on final foam temperature and needs to be taken into consideration when creating foam.

  12. Foam stabilization by solid particle aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Guignot, S.; Faure, S. [CEA Marcoule, Lab. des Procedes Avances de Decontamination, 30 (France); Pitois, O. [UniversiteParis-Est Marne-La-Valle, Lab. Physique des Materiaux Divises et des Interfaces (LPMDI), 77 - Marne la Vallee (France)

    2008-07-01

    During the dismantling of nuclear facilities, radioactive deposits on exposed areas are removed and solubilized by successive rinses of reactive liquid. Using this liquid in a foam state reduces the amount of resulting wastes. During the required decontamination time (1 to 5 hours) the foam has to be sufficiently wet (1). In the Laboratory of Advanced Processes for Decontamination, new formulations are currently studied to slow down the drainage kinetics of these foams, by adding colloidal particles of hydrophilic fumed silica into the classical mixtures of well-defined non ionic foaming surfactants previously used (2). The objective of our study is to shed light on the foam surprising stability induced by these particles. The study focuses on drainage of foams generated by air sparging through a suspension lying on a porous glass. The foaming suspensions contain between 0 and 70 g.L-1 of a fumed silica (Aerosil 380) which is well-known to form gels for concentrations above 200 g.L{sup -1}. In the studied solutions this silica builds up into aggregates of dozens of microns, whose volume-averaged mean diameter after sonication is centred around 300 nm. Under gentle stirring, they display no sign of re-aggregation during 24 h. On a free drainage configuration, a foam that contains particles keeps a significant amount of its initial liquid: up to 60 % during up to 5 hours, in contrast to classical foams that drain out all of their liquid in about 20 minutes. From a rheological point of view, the most concentrated suspensions display a yield stress behaviour. This evidences the structuring of the aggregates into a coherent network that might explain the incomplete drainage of the solutions. For the lowest concentrated solutions, such rheological properties have not been observed although the corresponding foams can retain large amount of solution. This suggests that local concentrations of aggregates can rise owing to their retention by foam channels, until they form

  13. Recycling of PUR scrap from car seats-glycolysis of flexible PUR foam

    Czech Academy of Sciences Publication Activity Database

    Beneš, Hynek; Holler, Petr; Schmidt, Pavel; Horák, Zdeněk; Rösner, J.

    2005-01-01

    Roč. 99, - (2005), s. 29 ISSN 0009-2770. [International Conference on Polymeric Materials in Automotive , Slovak Rubber Conference /17./. 10.5.2005-12.5.2005, Bratislava] Institutional research plan: CEZ:AV0Z40500505 Keywords : chemical recycling * flexible polyurethane foam * glycolysis Subject RIV: CD - Macromolecular Chemistry

  14. Laser Absorption and Energy Transfer in Foams of Various Pore Structures and Chemical Compositions,

    Czech Academy of Sciences Publication Activity Database

    Limpouch, J.; Borisenko, N.G.; Demchenko, N. N.; Gus´kov, S.Y.; Kasperczuk, A.; Khalenkov, A.M.; Kondrashov, V. N.; Krouský, Eduard; Kuba, J.; Mašek, Karel; Merkul´ev, A.Y.; Nazarov, W.; Pisarczyk, P.; Pisarczyk, T.; Pfeifer, Miroslav; Renner, Oldřich; Rozanov, V. B.

    2006-01-01

    Roč. 133, - (2006), s. 457-459 ISSN 1155-4339 R&D Projects: GA MŠk(CZ) LC528 Grant - others:INTAS(XE) 01-0572 Institutional research plan: CEZ:AV0Z10100523 Keywords : laser absorption * energy transfer * foam Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.315, year: 2006

  15. Handbook of plastic foams: types, properties, manufacture, and applications

    National Research Council Canada - National Science Library

    Landrock, Arthur H

    1995-01-01

    ... is an introduction and also covers the subject of foam formation. The chapter includes a discussion of the Montreal Protocol mandating the development of foams with substantially reduced CFC content by 1995. Chapter 2 is a comprehensive discussion of thermosetting foams of all types, with the emphasis on urethane and phenolic foams. The authors, K Ashida and K Iwa...

  16. USING BIOPOLYMERS TO STABILIZE THE PROTEIN OXYGEN FOAM

    Directory of Open Access Journals (Sweden)

    N. V. Nepovinnyh

    2013-01-01

    Full Text Available The cottage cheese whey as an oxygen cocktail foaming base and natural juices as a flavoring ingredient are analyzed. The lifetime of foam generated by the serum proteins is not long: foam falls off rapidly; because from the foam liquid is released (syneresis. The effects of plant polysaccharides on the stabilization of the protein foam oxygen cocktail is studied. It was shown that the use of plant polysaccharides (guar gum, high methoxyl citrus pectin, locust been gum prolong the life of the foam up to 20 times, compared with conventional blowing agents. It was found that oxygen foam properties depend on the molecular weight of guar gum.

  17. Blast wave protection of aqueous foams

    Energy Technology Data Exchange (ETDEWEB)

    Britan, Alexander; Ben-Dor, M. Liverts G. [Shock tube Laboratory of Protective Technologies R and D Center, Department of Mechanical Engineering, Faculty of Engineering Sciences, Ben Gurion University, Beer-Sheva (Israel)

    2011-07-01

    The primary intention of the present study is to present new contribution of shock tube tests to the problem of particle related stabilization and enhanced mitigation action of the wet particulate foams. The experiments reported were designed to examine (i) the reflection of a shock wave from an air/foam face, (ii) the transmission of the shock wave through the air/foam face and (iii) propagation and dispersion of the transmitted shock wave inside the foam column. Because wet aqueous foam of desired specification is difficult to reproduce, handle and quantitatively characterize the fact that experiments on all the above aspects were conducted in a single facility is a potentially important consideration. Moreover vertical position of shock tube simplified the issues since the gradient of the liquid fraction in draining foam coincides with the shock wave propagation. Under these, much simplified test conditions resulted flows could be treated as one-dimensional and the shock wave mitigation depends on three parameters: the intensity of the incident shock wave, s M , the duration of the foam decay, ∆t and on the particle concentration, n.

  18. Tensile and fracture behavior of polymer foams

    International Nuclear Information System (INIS)

    Kabir, Md. E.; Saha, M.C.; Jeelani, S.

    2006-01-01

    Tensile and mode-I fracture behavior of cross-linked polyvinyl chloride (PVC) and rigid polyurethane (PUR) foams are examined. Tension tests are performed using prismatic bar specimens and mode-I fracture tests are performed using single edge notched bend (SENB) specimens under three-point bending. Test specimens are prepared from PVC foams with three densities and two different levels of cross-linking, and PUR foam with one density. Tension and quasi-static fracture tests are performed using a Zwick/Rowell test machine. Dynamic fracture tests are performed using a DYNATUP model 8210 instrumented drop-tower test set up at three different impact energy levels. Various parameters such as specimen size, loading rate, foam density, cross-linking, crack length, cell orientation (flow and rise-direction) and solid polymer material are studied. It is found that foam density and solid polymer material have a significant effect on tensile strength, modulus, and fracture toughness of polymer foams. Level of polymer cross-linking is also found to have a significant effect on fracture toughness. The presence of cracks in the rise- and flow direction as well as loading rate has minimal effect. Dynamic fracture behavior is found to be different as compared to quasi-static fracture behavior. Dynamic fracture toughness (K d ) increases with impact energy. Examination of fracture surfaces reveals that the fracture occurs in fairly brittle manner for all foam materials

  19. Foam-on-Tile Damage Model

    Science.gov (United States)

    Koharchik, Michael; Murphy, Lindsay; Parker, Paul

    2012-01-01

    An impact model was developed to predict how three specific foam types would damage the Space Shuttle Orbiter insulating tiles. The inputs needed for the model are the foam type, the foam mass, the foam impact velocity, the foam impact incident angle, the type being impacted, and whether the tile is new or aged (has flown at least one mission). The model will determine if the foam impact will cause damage to the tile. If it can cause damage, the model will output the damage cavity dimensions (length, depth, entry angle, exit angle, and sidewall angles). It makes the calculations as soon as the inputs are entered (less than 1 second). The model allows for the rapid calculation of numerous scenarios in a short time. The model was developed from engineering principles coupled with significant impact testing (over 800 foam impact tests). This model is applicable to masses ranging from 0.0002 up to 0.4 pound (0.09 up to 181 g). A prior tool performed a similar function, but was limited to the assessment of a small range of masses and did not have the large test database for verification. In addition, the prior model did not provide outputs of the cavity damage length, entry angle, exit angle, or sidewall angles.

  20. Mechanical Characterization of Lightweight Foamed Concrete

    Directory of Open Access Journals (Sweden)

    Marcin Kozłowski

    2018-01-01

    Full Text Available Foamed concrete shows excellent physical characteristics such as low self weight, relatively high strength and superb thermal and acoustic insulation properties. It allows for minimal consumption of aggregate, and by replacement of a part of cement by fly ash, it contributes to the waste utilization principles. For many years, the application of foamed concrete has been limited to backfill of retaining walls, insulation of foundations and roof tiles sound insulation. However, during the last few years, foamed concrete has become a promising material for structural purposes. A series of tests was carried out to examine mechanical properties of foamed concrete mixes without fly ash and with fly ash content. In addition, the influence of 25 cycles of freezing and thawing on the compressive strength was investigated. The apparent density of hardened foamed concrete is strongly correlated with the foam content in the mix. An increase of the density of foamed concrete results in a decrease of flexural strength. For the same densities, the compressive strength obtained for mixes containing fly ash is approximately 20% lower in comparison to the specimens without fly ash. Specimens subjected to 25 freeze-thaw cycles show approximately 15% lower compressive strengths compared to the untreated specimens.

  1. Microstructure of high-strength foam concrete

    International Nuclear Information System (INIS)

    Just, A.; Middendorf, B.

    2009-01-01

    Foam concretes are divided into two groups: on the one hand the physically foamed concrete is mixed in fast rotating pug mill mixers by using foaming agents. This concrete cures under atmospheric conditions. On the other hand the autoclaved aerated concrete is chemically foamed by adding aluminium powder. Afterwards it is cured in a saturated steam atmosphere. New alternatives for the application of foam concretes arise from the combination of chemical foaming and air curing in manufacturing processes. These foam concretes are new and innovative building materials with interesting properties: low mass density and high strength. Responsible for these properties are the macro-, meso- and microporosity. Macropores are created by adding aluminium powder in different volumes and with different particle size distributions. However, the microstructure of the cement matrix is affected by meso- and micropores. In addition, the matrix of the hardened cement paste can be optimized by the specific use of chemical additives for concrete. The influence of aluminium powder and chemical additives on the properties of the microstructure of the hardened cement matrices were investigated by using petrographic microscopy as well as scanning electron microscopy.

  2. Drainage and Stratification Kinetics of Foam Films

    Science.gov (United States)

    Zhang, Yiran; Sharma, Vivek

    2014-03-01

    Baking bread, brewing cappuccino, pouring beer, washing dishes, shaving, shampooing, whipping eggs and blowing bubbles all involve creation of aqueous foam films. Foam lifetime, drainage kinetics and stability are strongly influenced by surfactant type (ionic vs non-ionic), and added proteins, particles or polymers modify typical responses. The rate at which fluid drains out from a foam film, i.e. drainage kinetics, is determined in the last stages primarily by molecular interactions and capillarity. Interestingly, for certain low molecular weight surfactants, colloids and polyelectrolyte-surfactant mixtures, a layered ordering of molecules, micelles or particles inside the foam films leads to a stepwise thinning phenomena called stratification. Though stratification is observed in many confined systems including foam films containing particles or polyelectrolytes, films containing globular proteins seem not to show this behavior. Using a Scheludko-type cell, we experimentally study the drainage and stratification kinetics of horizontal foam films formed by protein-surfactant mixtures, and carefully determine how the presence of proteins influences the hydrodynamics and thermodynamics of foam films.

  3. Tooling Foam for Structural Composite Applications

    Science.gov (United States)

    DeLay, Tom; Smith, Brett H.; Ely, Kevin; MacArthur, Doug

    1998-01-01

    Tooling technology applications for composite structures fabrication have been expanded at MSFC's Productivity Enhancement Complex (PEC). Engineers from NASA/MSFC and Lockheed Martin Corporation have developed a tooling foam for use in composite materials processing and manufacturing that exhibits superior thermal and mechanical properties in comparison with other tooling foam materials. This tooling foam is also compatible with most preimpregnated composite resins such as epoxy, bismaleimide, phenolic and their associated cure cycles. MARCORE tooling foam has excellent processability for applications requiring either integral or removable tooling. It can also be tailored to meet the requirements for composite processing of parts with unlimited cross sectional area. A shelf life of at least six months is easily maintained when components are stored between 50F - 70F. The MARCORE tooling foam system is a two component urethane-modified polyisocyanurate, high density rigid foam with zero ozone depletion potential. This readily machineable, lightweight tooling foam is ideal for composite structures fabrication and is dimensionally stable at temperatures up to 350F and pressures of 100 psi.

  4. DRY MIX FOR OBTAINING FOAM CONCRETE

    Directory of Open Access Journals (Sweden)

    S. N. Leonovich

    2015-01-01

    Full Text Available Composition of a dry mix has been developed for production of non-autoclaved foam concrete with natural curing. The mix has been created on the basis of Portland cement, UFAPORE foaming agent, mineral additives (RSAM sulfoaluminate additive, MK-85 micro-silica and basalt fiber, plasticizing and accelerating “Citrate-T” additive and   redispersible Vinnapas-8034 H powder. It has been established that foam concrete with  density of 400–800 kg/m3, durability of 1,1–3,4 MPa, low water absorption (40–50 %, without shrinkable cracks has been formed while adding water of Water/Solid = 0.4–0.6 in the dry mix,  subsequent mechanical swelling and curing of foam mass.Introduction of the accelerating and plasticizing “Citrate-T” additive into composition of the dry mix leads to an increase of rheological properties in expanded foam mass and  time reduction of its drying and curing. An investigation on microstructure of foam-concrete chipping surface carried out with the help of a scanning electron microscope has shown that the introduction of  basalt fiber and redispersible Vinnapas-8034 H powder into the composition of the dry mix promotes formation of more finely-divided crystalline hydrates. Such approach makes it possible to change purposefully morphology of crystalline hydrates and gives the possibility to operate foam concrete structurization process.

  5. Influence of the glass-calcium carbonate mixture's characteristics on the foaming process and the properties of the foam glass

    DEFF Research Database (Denmark)

    König, Jakob; Petersen, Rasmus Rosenlund; Yue, Yuanzheng

    2014-01-01

    We prepared foam glasses from cathode-ray-tube panel glass and CaCO3 as a foaming agent. We investigated the influences of powder preparation, CaCO3 concentration and foaming temperature and time on the density, porosity and homogeneity of the foam glasses. The results show that the decomposition...

  6. Influence of Rubber Powders on Foaming Behavior and Mechanical Properties of Foamed Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    HE Yue

    2017-02-01

    Full Text Available Polypropylene/rubber powders composites with different kinds of rubber powders were foamed by injection molding machine equipped with volume-adjustable cavity. The effect of dispersity of rubber powders and crystallization behavior of composites on the foaming behavior and mechanical properties was investigated. The results show that the addition of rubber powders can improve the cell structure of foamed PP with fine and uniform cell distribution. And cell density and size of PP/PP-MAH/NBR foams are 7.64×106cell/cm3 and 29.78μm respectively, which are the best among these foams. Combining cell structures with mechanical properties, notch impact strength of PP/PP-MAH/CNBR composites increases approximately by 2.2 times while tensile strength is reduced just by 26% compared with those of the pure PP. This indicates that PP/PP-MAH/CNBR composites are ideal foamed materials.

  7. Multifunctional foaming agent to prepare aluminum foam with enhanced mechanical properties

    Science.gov (United States)

    Li, Xun; Liu, Ying; Ye, Jinwen; An, Xuguang; Ran, Huaying

    2018-03-01

    In this paper, CuSO4 was used as foaming agent to prepare close cell Aluminum foam(Al foam) at the temperature range of 680 °C ∼ 758 °C for the first time. The results show that CuSO4 has multifunctional such as, foaming, viscosity increasing, reinforcement in Al matrix, it has a wide decomposition temperature range of 641 °C ∼ 816 °C, its sustain-release time is 5.5 min at 758 °C. The compression stress and energy absorption of CuSO4-Al foam is 6.89 Mpa and 4.82 × 106 J m‑3(compression strain 50%), which are 77.12% and 99.17% higher than that of TiH2-Al foam at the same porosity(76% in porosity) due to the reinforcement in Al matrix and uniform pore dispersion.

  8. FOAM3D: A numerical simulator for mechanistic prediciton of foam displacement in multidimensions

    Energy Technology Data Exchange (ETDEWEB)

    Kovscek, A.R.; Patzek, T.W. [Lawrence Berkeley Laboratory, Berkeley, CA (United States); Radke, C.J. [Univ. of California, Berkeley, CA (United States)

    1995-03-01

    Field application of foam is a technically viable enhanced oil recovery process (EOR) as demonstrated by recent steam-foam field studies. Traditional gas-displacement processes, such as steam drive, are improved substantially by controlling gas mobility and thereby improving volumetric displacement efficiency. For instance, Patzek and Koinis showed major oil-recovery response after about two years of foam injection in two different pilot studies at the Kern River field. They report increased production of 5.5 to 14% of the original oil in place over a five year period. Because reservoir-scale simulation is a vital component of the engineering and economic evaluation of any EOR project, efficient application of foam as a displacement fluid requires a predictive numerical model of foam displacement. A mechanistic model would also expedite scale-up of the process from the laboratory to the field scale. No general, mechanistic, field-scale model for foam displacement is currently in use.

  9. Rigid Polyurethane Foam Reinforced Coconut Coir Fiber Properties

    OpenAIRE

    Mohd Azham Azmi

    2012-01-01

    This research work studied the properties of composite foam panels. Coconut coir fibers were used as reinforcement in polyurethane (PU) foam in order to increase the properties of foam. This composite foam panels were fabricated by using polyurethane molded method. The polyurethane foam panels reinforced from 5 to 20wt% coconut coir were produced to investigate the physical and mechanical test via density test and three point bending test respectively. It was found that the density test resul...

  10. Foam droplet separation for nanoparticle synthesis

    International Nuclear Information System (INIS)

    Tyree, Corey A.; Allen, Jonathan O.

    2008-01-01

    A novel approach to nanoparticle synthesis was developed whereby foam bubble bursting produced aerosol droplets, an approach patterned after the marine foam aerosol cycle. The droplets were dried to remove solvent, leaving nanometer-sized particles composed of precursor material. Nanoparticles composed of sodium chloride (mean diameter, D-bar p ∼ 100 nm), phosphotungstic acid (D-bar p ∼ 55 nm), and bovine insulin (D p ∼ 5-30 nm) were synthesized. Foam droplet separation can be carried out at ambient temperature and pressure. The 'soft' nature of the process makes it compatible with a wide range of materials

  11. Behaviour of aluminum foam under fire conditions

    Directory of Open Access Journals (Sweden)

    J. Grabian

    2008-07-01

    Full Text Available Taking into account fire-protection requirements it is advantageous for aluminum foam, after melting at a temperature considerably exceeding the melting point, to have a structure of discontinuous suspension of solid inclusions to liquid metal instead of liquid consistency. Continuity of the suspension depends on the solid phase content. The boundary value of the phase determined by J. Śleziona, above which the suspension becomes discontinuous, is provided by the formula (1. Figure 1 presents the relationship graphically. Boundary values of the vs content resulting from the above relationship is too low, taking into account the data obtained from the technology of suspension composites [4]. Therefore, based on the structure assumed for the suspension shown in Figure 2 these authors proposed another way of determining the contents, the value of which is determined by the relationship (3 [5].For purposes of the experimental study presented in the paper two foams have been molten: a commercially available one, made by aluminum foaming with titanium hydride, and a foam manufactured in the Marine Materials Plant of the Maritime University of Szczecin by blowing the AlSi7 +20% SiC composite with argon. Macrophotographs of foam cross-sections are shown in Figure 3. The foams have been molten in the atmosphere of air at a temperature of 750ºC. The products of melting are presented in Figure 4. It appears that molten aluminum foam may have no liquid consistency, being unable to flow, which is a desired property from the point of view of fire-protection. The above feature of the molten foam results from the fact that it may be a discontinuous suspension of solid particles in a liquid metal. The suspended particles may be solid particles of the composite that served for making the foam or oxide membranes formed on extended metal surface of the bubbles included in the foam. The desired foam ability to form a discontinuous suspension after melting may be

  12. Auxetic foam for snowsport safety devices

    OpenAIRE

    Allen, Tom; Duncan, Olly; Foster, Leon; Senior, Terry; Zampieri, Davide; Edeh, Victor; Alderson, Andrew

    2017-01-01

    Skiing and snowboarding are popular snow-sports with inherent risk of injury. There is potential to reduce the prevalence of injuries by improving and implementing snow-sport safety devices with the application of advanced materials. This paper investigates the application of auxetic foam to snow-sport safety devices. Composite pads - consisting of foam covered with a semi-rigid shell - were investigated as a simple model of body armour and a large 70 x 355 x 355 mm auxetic foam sample was fa...

  13. Foam process for application of decontamination agents

    International Nuclear Information System (INIS)

    Harris, J.M.; Miller, J.R.; Frazier, R.S.; Walter, J.H.

    1982-01-01

    This paper presents the results and observations of a study performed by the authors to parametrically evaluate the performance characteristics of a foam process for application of decontamination agents. The initial tests were established to assess foam quality. Subsequent tests determined the ability of the foam as a carrier of chemical systems, and established system operating parameters. The technique was then applied in an actual decontamination task to verify effectiveness of these established parameters and to determine decontamination reduction factors. 4 figures, 5 tables

  14. In-vitro investigation of out-of-field cell survival following the delivery of conformal, intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans

    International Nuclear Information System (INIS)

    McGarry, Conor K; Hounsell, Alan R; Butterworth, Karl T; Trainor, Colman; McMahon, Stephen J; O'Sullivan, Joe M; Prise, Kevin M

    2012-01-01

    The aim of this work is to determine the out-of-field survival of cells irradiated with either the primary field or scattered radiation in the presence and absence of intercellular communication following delivery of conformal, IMRT and VMAT treatment plans. Single beam, conformal, IMRT and VMAT plans were created to deliver 3 Gy to half the area of a T80 flask containing either DU-145 or AGO-1522 cells allowing intercellular communication between the in- and out-of-field cell populations. The same plans were delivered to a similar custom made phantom used to hold two T25 culture flasks, one flask in-field and one out-of-field to allow comparison of cell survival responses when intercellular communication is physically inhibited. Plans were created for the delivery of 8 Gy to the more radio-resistant DU-145 cells only in the presence and absence of intercellular communication. Cell survival was determined by clonogenic assay. In both cell lines, the out-of-field survival was not statistically different between delivery techniques for either cell line or dose. There was however, a statistically significant difference between survival out-of-field when intercellular communication was intact (single T80 culture flask) or inhibited (multiple T25 culture flasks) to in-field for all plans. No statistically significant difference was observed in-field with or without cellular communication to out-of-field for all plans. These data demonstrate out-of-field effects as important determinants of cell survival following exposure to modulated irradiation fields when cellular communication between differentially irradiated cell populations is present. This data is further evidence that refinement of existing radiobiological models to include indirect cell killing effects is required. (paper)

  15. Flame Retardants Used in Flexible Polyurethane Foam

    Science.gov (United States)

    The partnership project on flame retardants in furniture seeks to update the health and environmental profiles of flame-retardant chemicals that meet fire safety standards for upholstered consumer products with polyurethane foam

  16. Feynman propagator for spin foam quantum gravity.

    Science.gov (United States)

    Oriti, Daniele

    2005-03-25

    We link the notion causality with the orientation of the spin foam 2-complex. We show that all current spin foam models are orientation independent. Using the technology of evolution kernels for quantum fields on Lie groups, we construct a generalized version of spin foam models, introducing an extra proper time variable. We prove that different ranges of integration for this variable lead to different classes of spin foam models: the usual ones, interpreted as the quantum gravity analogue of the Hadamard function of quantum field theory (QFT) or as inner products between quantum gravity states; and a new class of causal models, the quantum gravity analogue of the Feynman propagator in QFT, nontrivial function of the orientation data, and implying a notion of "timeless ordering".

  17. Coated foams, preparation, uses and articles

    Science.gov (United States)

    Duchane, D.V.; Barthell, B.L.

    1982-10-21

    Hydrophobic cellular material is coated with a thin hydrophilic polymer skin which stretches tightly over the foam but which does not fill the cells of the foam, thus resulting in a polymer-coated foam structure having a smoothness which was not possible in the prior art. In particular, when the hydrophobic cellular material is a specially chosen hydrophobic polymer foam and is formed into arbitrarily chosen shapes prior to the coating with hydrophilic polymer, inertial confinement fusion (ICF) targets of arbitrary shapes can be produced by subsequently coating the shapes with metal or with any other suitable material. New articles of manufacture are produced, including improved ICF targets, improved integrated circuits, and improved solar reflectors and solar collectors. In the coating method, the cell size of the hydrophobic cellular material, the viscosity of the polymer solution used to coat, and the surface tension of the polymer solution used to coat are all very important to the coating.

  18. Grandstand view of phenolic foam insulation

    Energy Technology Data Exchange (ETDEWEB)

    1987-03-01

    Stadium Insulation Ltd, manufacture pipe sections, tank and vessel insulation products in Lowphen, polyisocyanurate, polyurethane foams and expanded polystyrene, though for certain specialist applications, cork is still employed in small quantities. Currently the emphasis is very much on Lowphen, the company's range of pipe sections based on phenolic foam. The company's manufacturing and marketing effort reflects the increasing market trend towards the use of insulating material capable of withstanding higher temperatures, and phenolic foam neatly satisfies the demand since it is capable of use at temperatures up to 140/sup 0/C. Moreover, phenolic foam has the lowest K value at 0.02W/m/sup 0/C of any of the currently available range of insulating materials, and while the product is slightly more expensive than alternatives such as polyisocyanurate and polyurethane, its high performance offsets that premium.

  19. Family planning, antenatal and delivery care: cross-sectional survey evidence on levels of coverage and inequalities by public and private sector in 57 low- and middle-income countries.

    Science.gov (United States)

    Campbell, Oona M R; Benova, Lenka; MacLeod, David; Baggaley, Rebecca F; Rodrigues, Laura C; Hanson, Kara; Powell-Jackson, Timothy; Penn-Kekana, Loveday; Polonsky, Reen; Footman, Katharine; Vahanian, Alice; Pereira, Shreya K; Santos, Andreia Costa; Filippi, Veronique G A; Lynch, Caroline A; Goodman, Catherine

    2016-04-01

    The objective of this study was to assess the role of the private sector in low- and middle-income countries (LMICs). We used Demographic and Health Surveys for 57 countries (2000-2013) to evaluate the private sector's share in providing three reproductive and maternal/newborn health services (family planning, antenatal and delivery care), in total and by socio-economic position. We used data from 865 547 women aged 15-49, representing a total of 3 billion people. We defined 'met and unmet need for services' and 'use of appropriate service types' clearly and developed explicit classifications of source and sector of provision. Across the four regions (sub-Saharan Africa, Middle East/Europe, Asia and Latin America), unmet need ranged from 28% to 61% for family planning, 8% to 22% for ANC and 21% to 51% for delivery care. The private-sector share among users of family planning services was 37-39% across regions (overall mean: 37%; median across countries: 41%). The private-sector market share among users of ANC was 13-61% across regions (overall mean: 44%; median across countries: 15%). The private-sector share among appropriate deliveries was 9-56% across regions (overall mean: 40%; median across countries: 14%). For all three healthcare services, women in the richest wealth quintile used private services more than the poorest. Wealth gaps in met need for services were smallest for family planning and largest for delivery care. The private sector serves substantial numbers of women in LMICs, particularly the richest. To achieve universal health coverage, including adequate quality care, it is imperative to understand this sector, starting with improved data collection on healthcare provision. © 2016 The Authors. Tropical Medicine & International Health published by John Wiley & Sons Ltd.

  20. Adhesion aspects of polyurethane foam sandwich panels.

    OpenAIRE

    Ng, Simon L.

    2016-01-01

    Sandwich panels, polyurethane foam sandwiched between two sheets of steel, form the walls and roofs in the construction of buildings. ArcelorMittal is a manufacturer of the steel as well as these finished panels. For this project they combined with a supplier of the polyurethane foams, Huntsman Polyurethanes, to joint-fund a research project investigating the fundamental mechanisms of adhesion, as well as the causes of failures in the product which manifests primarily in two different ways...

  1. Measurement of radiant properties of ceramic foam

    International Nuclear Information System (INIS)

    Hoornstra, J.; Turecky, M.; Maatman, D.

    1994-07-01

    An experimental facility is described for the measurement of the normal spectral and total emissivity and transmissivity of semi-transparent materials in the temperature range of 600 C to 1200 C. The set-up was used for the measurement of radiation properties of highly porous ceramic foam which is used in low NO x radiant burners. Emissivity and transmissivity data were measured and are presented for coated and uncoated ceramic foam of different thicknesses. (orig.)

  2. New supply for canyon fire foam system

    International Nuclear Information System (INIS)

    Gainey, T.

    1995-01-01

    The raw water supply for the B-Plant Canyon fire foam system is being replaced. The 4 inche water supply line to the foam system is being rerouted from the 6 inches raw water line in the Pipe Gallery to the 10 inches raw water main in the Operating Gallery. This document states the acceptance criteria for the flushing and testing to be performed by the contractor

  3. Foam radiators for transition radiation detectors

    International Nuclear Information System (INIS)

    Chernyatin, V.; Dolgoshein, B.; Gavrilenko, I.; Potekhin, M.; Romaniouk, A.; Sosnovtsev, V.

    1993-01-01

    A wide variety of foam radiators, potentially useful in the design of a transition radiation detector, the possible particle identification tool in collider experiments, have been tested in the beam. Various characteristics of these radiators are compared, and the conclusion is reached that certain brands of polyethylene foam are best suited for use in the detector. Comparison is made with a 'traditional' radiator, which is a periodic structure of plastic foils. (orig.)

  4. Mechanical Characterization of Lightweight Foamed Concrete

    OpenAIRE

    Marcin Kozłowski; Marta Kadela

    2018-01-01

    Foamed concrete shows excellent physical characteristics such as low self weight, relatively high strength and superb thermal and acoustic insulation properties. It allows for minimal consumption of aggregate, and by replacement of a part of cement by fly ash, it contributes to the waste utilization principles. For many years, the application of foamed concrete has been limited to backfill of retaining walls, insulation of foundations and roof tiles sound insulation. However, during the last ...

  5. Structure formation control of foam concrete

    Science.gov (United States)

    Steshenko, Aleksei; Kudyakov, Aleksander; Konusheva, Viktoriya; Syrkin, Oleg

    2017-01-01

    The process of predetermined foam concrete structure formation is considered to be a crucial issue from the point of process control and it is currently understudied thus defining the need for additional research. One of the effective ways of structure formation control in naturally hardening foam concrete is reinforcement with dispersed fibers or introduction of plasticizers. The paper aims at studying the patterns of influence of microreinforcing and plasticizing additives on the structure and performance properties of foam concrete. Preparation of foam concrete mix has been conducted using one-step technology. The structure of modified foam concrete has been studied by means of electron microscopy. The cellular structure of foam concrete samples with the additives is homogeneous; the pores are uniformly distributed over the total volume. It has been revealed that introduction of the Neolas 5.2 plasticizer and microreinforcing fibers in the foam concrete mixture in the amount of 0.4 - 0.1 % by weight of cement leads to reduction of the average pore diameter in the range of 45.3 to 30.2 microns and the standard deviation of the pore average diameter from 23.6 to 9.2 in comparison with the sample without additive. Introduction of modifying additives has stimulated formation of a large number of closed pores. Thus porosity of conditionally closed pores has increased from 16.06 % to 34.48 %, which has lead to increase of frost resistance brand of foam concrete from F15 to F50 and to reduction of its water absorption by weight by 20 %.

  6. The OpenFOAM technology primer

    CERN Document Server

    Maric, Tomislav; Mooney, Kyle

    2014-01-01

    This book covers two main aspects of working with OpenFOAM: using the applications and developing and extending the library code. In the first part of the book, we chose a few utilities and applications to describe the OpenFOAM work flow. This information should provide a sufficient starting point for the reader, who can investigate his/her interests further by following the provided instructions in a similar way for another solver or application.

  7. Liquid foam templating - A route to tailor-made polymer foams.

    Science.gov (United States)

    Andrieux, Sébastien; Quell, Aggeliki; Stubenrauch, Cosima; Drenckhan, Wiebke

    2018-06-01

    Solid foams with pore sizes between a few micrometres and a few millimetres are heavily exploited in a wide range of established and emerging applications. While the optimisation of foam applications requires a fine control over their structural properties (pore size distribution, pore opening, foam density, …), the great complexity of most foaming processes still defies a sound scientific understanding and therefore explicit control and prediction of these parameters. We therefore need to improve our understanding of existing processes and also develop new fabrication routes which we understand and which we can exploit to tailor-make new porous materials. One of these new routes is liquid templating in general and liquid foam templating in particular, to which this review article is dedicated. While all solid foams are generated from an initially liquid(-like) state, the particular notion of liquid foam templating implies the specific condition that the liquid foam has time to find its "equilibrium structure" before it is solidified. In other words, the characteristic time scales of the liquid foam's stability and its solidification are well separated, allowing to build on the vast know-how on liquid foams established over the last 20 years. The dispersed phase of the liquid foam determines the final pore size and pore size distribution, while the continuous phase contains the precursors of the desired porous scaffold. We review here the three key challenges which need to be addressed by this approach: (1) the control of the structure of the liquid template, (2) the matching of the time scales between the stability of the liquid template and solidification, and (3) the preservation of the structure of the template throughout the process. Focusing on the field of polymer foams, this review gives an overview of recent research on the properties of liquid foam templates and summarises a key set of studies in the emerging field of liquid foam templating. It

  8. Comparison of sound absorbing performances of copper foam and iron foam with the same parameters

    Science.gov (United States)

    Yang, X. C.; Shen, X. M.; Xu, P. J.; Zhang, X. N.; Bai, P. F.; Peng, K.; Yin, Q.; Wang, D.

    2018-01-01

    Sound absorbing performances of the copper foam and the iron foam with the same parameters were investigated by the AWA6128A detector according to standing wave method. Two modes were investigated, which included the pure metal foam mode and the combination mode with the settled thickness of metal foam. In order to legibly compare the sound absorbing coefficients of the two metal foams, the detected sound frequency points were divided into the low frequency range (100 Hz ~ 1000 Hz), the middle frequency range (1000 Hz ~ 3200 Hz), and the high frequency range (3500 Hz ~ 6000 Hz). Sound absorbing performances of the two metal foams in the two modes were discussed within the three frequency ranges in detail. It would be calculated that the average sound absorbing coefficients of copper foam in the pure metal foam mode were 12.6%, 22.7%, 34.6%, 43.6%, 51.1%, and 56.2% when the thickness was 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, and 30 mm. meanwhile, in the combination mode, the average sound absorbing coefficients of copper foam with the thickness of 10 mm were 30.6%, 34.8%, 36.3%, and 35.8% when the cavity was 5 mm, 10 mm, 15 mm, and 20 mm. In addition, those of iron foam in the pure metal foam mode were 13.4%, 20.1%, 34.4%, 43.1%, 49.6%, and 56.1%, and in the combination mode were 25.6%, 30.5%, 34.3%, and 33.4%.

  9. Applications of Polymer Matrix Syntactic Foams

    Science.gov (United States)

    Gupta, Nikhil; Zeltmann, Steven E.; Shunmugasamy, Vasanth Chakravarthy; Pinisetty, Dinesh

    2013-11-01

    A collection of applications of polymer matrix syntactic foams is presented in this article. Syntactic foams are lightweight porous composites that found their early applications in marine structures due to their naturally buoyant behavior and low moisture absorption. Their light weight has been beneficial in weight sensitive aerospace structures. Syntactic foams have pushed the performance boundaries for composites and have enabled the development of vehicles for traveling to the deepest parts of the ocean and to other planets. The high volume fraction of porosity in syntactic foams also enabled their applications in thermal insulation of pipelines in oil and gas industry. The possibility of tailoring the mechanical and thermal properties of syntactic foams through a combination of material selection, hollow particle volume fraction, and hollow particle wall thickness has helped in rapidly growing these applications. The low coefficient of thermal expansion and dimensional stability at high temperatures are now leading their use in electronic packaging, composite tooling, and thermoforming plug assists. Methods have been developed to tailor the mechanical and thermal properties of syntactic foams independent of each other over a wide range, which is a significant advantage over other traditional particulate and fibrous composites.

  10. Numerical simulation of anisotropic polymeric foams

    Directory of Open Access Journals (Sweden)

    Volnei Tita

    Full Text Available This paper shows in detail the modelling of anisotropic polymeric foam under compression and tension loadings, including discussions on isotropic material models and the entire procedure to calibrate the parameters involved. First, specimens of poly(vinyl chloride (PVC foam were investigated through experimental analyses in order to understand the mechanical behavior of this anisotropic material. Then, isotropic material models available in the commercial software AbaqusTM were investigated in order to verify their ability to model anisotropic foams and how the parameters involved can influence the results. Due to anisotropy, it is possible to obtain different values for the same parameter in the calibration process. The obtained set of parameters are used to calibrate the model according to the application of the structure. The models investigated showed minor and major limitations to simulate the mechanical behavior of anisotropic PVC foams under compression, tension and multi-axial loadings. Results show that the calibration process and the choice of the material model applied to the polymeric foam can provide good quantitative results and save project time. Results also indicate what kind and order of error one will get if certain choices are made throughout the modelling process. Finally, even though the developed calibration procedure is applied to specific PVC foam, it still outlines a very broad drill to analyze other anisotropic cellular materials.

  11. Foam film permeability: theory and experiment.

    Science.gov (United States)

    Farajzadeh, R; Krastev, R; Zitha, Pacelli L J

    2008-02-28

    The mass transfer of gas through foam films is a prototype of various industrial and biological processes. The aim of this paper is to give a perspective and critical overview of studies carried out to date on the mass transfer of gas through foam films. Contemporary experimental data are summarized, and a comprehensive overview of the theoretical models used to explain the observed effects is given. A detailed description of the processes that occur when a gas molecule passes through each layer that forms a foam film is shown. The permeability of the film-building surfactant monolayers plays an important role for the whole permeability process. It can be successfully described by the models used to explain the permeability of surfactant monolayers on aqueous sub-phase. For this reason, the present paper briefly discusses the surfactant-induced resistance to mass transfer of gases through gas-liquid interface. One part of the paper discusses the experimental and theoretical aspects of the foam film permeability in a train of foam films in a matrix or a cylinder. This special case is important to explain the gas transfer in porous media or in foams. Finally, this paper will highlight the gaps and challenges and sketch possible directions for future research.

  12. Shrinkage deformation of cement foam concrete

    Science.gov (United States)

    Kudyakov, A. I.; Steshenko, A. B.

    2015-01-01

    The article presents the results of research of dispersion-reinforced cement foam concrete with chrysotile asbestos fibers. The goal was to study the patterns of influence of chrysotile asbestos fibers on drying shrinkage deformation of cement foam concrete of natural hardening. The chrysotile asbestos fiber contains cylindrical fiber shaped particles with a diameter of 0.55 micron to 8 microns, which are composed of nanostructures of the same form with diameters up to 55 nm and length up to 22 microns. Taking into account the wall thickness, effective reinforcement can be achieved only by microtube foam materials, the so- called carbon nanotubes, the dimensions of which are of power less that the wall pore diameter. The presence of not reinforced foam concrete pores with perforated walls causes a decrease in its strength, decreases the mechanical properties of the investigated material and increases its shrinkage. The microstructure investigation results have shown that introduction of chrysotile asbestos fibers in an amount of 2 % by weight of cement provides the finely porous foam concrete structure with more uniform size closed pores, which are uniformly distributed over the volume. This reduces the shrinkage deformation of foam concrete by 50%.

  13. SU-F-P-37: Implementation of An End-To-End QA Test of the Radiation Therapy Imaging, Planning and Delivery Process to Identify and Correct Possible Sources of Deviation

    International Nuclear Information System (INIS)

    Salinas Aranda, F; Suarez, V; Arbiser, S; Sansogne, R

    2016-01-01

    Purpose: To implement an end-to-end QA test of the radiation therapy imaging, planning and delivery process, aimed to assess the dosimetric agreement accuracy between planned and delivered treatment, in order to identify and correct possible sources of deviation. To establish an internal standard for machine commissioning acceptance. Methods: A test involving all steps of the radiation therapy: imaging, planning and delivery process was designed. The test includes analysis of point dose and planar dose distributions agreement between TPS calculated and measured dose. An ad hoc 16 cm diameter PMMA phantom was constructed with one central and four peripheral bores that can accommodate calibrated electron density inserts. Using Varian Eclipse 10.0 and Elekta XiO 4.50 planning systems, IMRT, RapidArc and 3DCRT with hard and dynamic wedges plans were planned on the phantom and tested. An Exradin A1SL chamber is used with a Keithley 35617EBS electrometer for point dose measurements in the phantom. 2D dose distributions were acquired using MapCheck and Varian aS1000 EPID.Gamma analysis was performed for evaluation of 2D dose distribution agreement using MapCheck software and Varian Portal Dosimetry Application.Varian high energy Clinacs Trilogy, 2100C/CD, 2000CR and low energy 6X/EX where tested.TPS-CT# vs. electron density table were checked for CT-scanners used. Results: Calculated point doses were accurate to 0.127% SD: 0.93%, 0.507% SD: 0.82%, 0.246% SD: 1.39% and 0.012% SD: 0.01% for LoX-3DCRT, HiX-3DCRT, IMRT and RapidArc plans respectively. Planar doses pass gamma 3% 3mm in all cases and 2% 2mm for VMAT plans. Conclusion: Implementation of a simple and reliable quality assurance tool was accomplished. The end-to-end proved efficient, showing excellent agreement between planned and delivered dose evidencing strong consistency of the whole process from imaging through planning to delivery. This test can be used as a first step in beam model acceptance for clinical

  14. Auxetic Polyurethane Foam (Fabrication, Properties and Applications)

    International Nuclear Information System (INIS)

    Yousif, H.I.Y.

    2012-01-01

    Modern technology requires new materials of special properties. For the last two decades there has been a great interest in a class of materials known as auxetic materials. An auxetic material is a material that has a negative Poisson's ratio which means that this material expands laterally when they subjected to a tensile force unlike most of the other traditional materials. This material has superior properties over the traditional material such as high shear modulus and high impact resistance, which makes this material a good candidate for many engineering applications. In the present research work, auxetic flexible polyurethane polymeric foams having different densities were fabricated from conventional flexible polyurethane polymeric foam at different compression ratios. The microstructure of conventional and processed foams was examined by optical microscope to compare between the two structures. The microstructure of processed foam was compared with the one presented in the literature and it has shown the auxetic structure configuration. This is the first time to produce auxetic foam in Egypt. Conventional and auxetic foam samples having cylindrical and square cross-sections were produced from foams having different densities (25 kg/m 3 and 30 kg/m 3 ). The compression ratios used to produce the auxetic samples are (5.56, 6.94 and 9.26). Four mechanical tests were carried out to get the mechanical properties for both conventional and auxetic foams. Two quasi-static mechanical tests t ension and compression a nd two dynamic mechanical tests H ysteresis and resilience w ere carried out to compare between the conventional and auxetic foams. The quasi-static tensile test was carried out at speed was adjusted to be position control rate of 0.2 mm/s. The compression and hysteresis tests were carried out at strain control rate of 0.3 S -1 . The data recorded from the machine were stress and strain. The modulus of elasticity and Poisson's ratio of the test

  15. Foam application from a closed system – a study of machine and foam parameters

    NARCIS (Netherlands)

    Lemmen, Jacques T.E.; Groot Wassink, Jan

    1990-01-01

    An attempt has been made to gain a greater insight into the interaction between foam and a moving textile substrate. The effects of changing wet pick–up, fabric velocity, liquid viscosity, foam density and mode of application on penetration have been studied. Application from a closed system makes

  16. TPX foams for inertial fusion laser experiments: foam preparation, machining, characterization, and discussion of density issues

    International Nuclear Information System (INIS)

    Grosse, M.; Guillot, L.; Reneaume, B.; Fleury, E.; Hermerel, C.; Choux, A.; Jeannot, L.; Geoffray, I.; Faivre, A.; Breton, O.; Andre, J.; Collier, R.; Legaie, O.

    2011-01-01

    Low density foams (in this work, foam density refers to apparent density) are materials of interest for fusion experiments. Low density poly(4-methyl-1-pentene)(commercial name TPX) foams have been produced for 30 years. TPX foams have been shown to have densities as low as 3 mg.cm -3 , which is very close to air density (1.2 mg.cm -3 ). Around this density foams are very light and highly fragile. Their fabrication is thus a real technological challenge. However, shrinking always appears in ranges ranking from 25% to almost 200%. As a result, the apparent density of the final foam never matches the expected value given by the precursor solution concentration. Besides, even if the mold dimensions are precisely known, shrinkage is never linear, and foams have to be machined for precise density measurement. In our work we present a fabrication process for TPX foams and discuss machining and density measuring issues. Particularly, we have found that there are volume and weight limits for a determination of density within the range of 3% uncertainty. This raises the question whether density should rather be determined directly on millimeter-sized targets or should be performed on a bigger scale sample prepared from the same batch. (authors)

  17. From Foam Rubber to Volcanoes: The Physical Chemistry of Foam Formation

    Science.gov (United States)

    Hansen, Lee D.; McCarlie, V. Wallace

    2004-01-01

    The process of foam formation is used for demonstrating the way in which the application of physiochemical principles and knowledge of the physical properties of the materials contributes towards the understanding of a wide range of phenomenon. Solubility of gas and bubble growth should be considered during the development of foamed polymer…

  18. Polymer foam comprising a polymer and nanoparticles, and nanoparticles for the manufacture of such foam.

    NARCIS (Netherlands)

    Vancso, Gyula J.; Duvigneau, Joost; Nederkoorn, P.H.J.; Wassing, T.

    2014-01-01

    A polymer foam is produced comprising a polymer and nanoparticles having a maximum dimensionof 750 nm, which foam has cells with an average cell size of at most 1 µm and a cell density of at least 1012 cells/ml, wherein polymeric grafts have been attached to the nanoparticles. The nanoparticles may

  19. New Approaches to Aluminum Integral Foam Production with Casting Methods

    Directory of Open Access Journals (Sweden)

    Ahmet Güner

    2015-08-01

    Full Text Available Integral foam has been used in the production of polymer materials for a long time. Metal integral foam casting systems are obtained by transferring and adapting polymer injection technology. Metal integral foam produced by casting has a solid skin at the surface and a foam core. Producing near-net shape reduces production expenses. Insurance companies nowadays want the automotive industry to use metallic foam parts because of their higher impact energy absorption properties. In this paper, manufacturing processes of aluminum integral foam with casting methods will be discussed.

  20. Foaming in manure based digesters: Effect of overloading and foam suppression using antifoam agents

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Tsapekos, Panagiotis; Boe, Kanokwan

    Anaerobic digestion foaming is one of the major problems that occasionally occur in full-scale biogas plants, affecting negatively the overall digestion process. The foam is typically created either in the main biogas reactor or/and in the pre-storage tank and the entrapped solids in the foam cause...... severe operational problems, such as blockage of mixing devices and collapse of pumps. Furthermore, the foaming problem is linked with economic consequences for biogas plants, due to income losses derived from the reduced biogas production, extra labour work and additional maintenance costs. Moreover....... A continuous stirred tank reactor, operating under thermophilic conditions (55 oC) was fed with cattle manure. In order to investigate the effect of organic overloading on foam formation, a stepwise increase of the organic loading rate was performed by the addition of glucose in the feeding substrate. Biogas...

  1. Graphite Foam Heat Exchangers for Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Klett, J.W.

    2004-06-07

    Improved thermal management is needed to increase the power density of electronic and more effectively cool electronic enclosures that are envisioned in future aircraft, spacecraft and surface ships. Typically, heat exchanger cores must increase in size to more effectively dissipate increased heat loads, this would be impossible in many cases, thus improved heat exchanger cores will be required. In this Phase I investigation, MRi aimed to demonstrate improved thermal management using graphite foam (Gr-foam) core heat exchangers. The proposed design was to combine Gr-foams from POCO with MRi's innovative low temperature, active metal joining process (S-Bond{trademark}) to bond Gr-foam to aluminum, copper and aluminum/SiC composite faceplates. The results were very favorable, so a Phase II SBIR with the MDA was initiated. This had primarily 5 tasks: (1) bonding, (2) thermal modeling, (3) cooling chip scale packages, (4) evaporative cooling techniques and (5) IGBT cold plate development. The bonding tests showed that the ''reflow'' technique with S-Bond{reg_sign}-220 resulted in the best and most consistent bond. Then, thermal modeling was used to design different chip scale packages and IGBT cold plates. These designs were used to fabricate many finned graphite foam heat sinks specifically for two standard type IC packages, the 423 and 478 pin chips. These results demonstrated several advantages with the foam. First, the heat sinks with the foam were lighter than the copper/aluminum sinks used as standards. The sinks for the 423 design made from foam were not as good as the standard sinks. However, the sinks made from foam for the 478 pin chips were better than the standard heat sinks used today. However, this improvement was marginal (in the 10-20% better regime). However, another important note was that the epoxy bonding technique resulted in heat sinks with similar results as that with the S-bond{reg_sign}, slightly worse than the S

  2. Measurements of lateral penumbra for uniform scanning proton beams under various beam delivery conditions and comparison to the XiO treatment planning system

    International Nuclear Information System (INIS)

    Rana, Suresh; Zeidan, Omar; Ramirez, Eric; Rains, Michael; Gao, Junfang; Zheng, Yuanshui

    2013-01-01

    Purpose: The main purposes of this study were to (1) investigate the dependency of lateral penumbra (80%–20% distance) of uniform scanning proton beams on various factors such as air gap, proton range, modulation width, compensator thickness, and depth, and (2) compare the lateral penumbra calculated by a treatment planning system (TPS) with measurements.Methods: First, lateral penumbra was measured using solid–water phantom and radiographic films for (a) air gap, ranged from 0 to 35 cm, (b) proton range, ranged from 8 to 30 cm, (c) modulation, ranged from 2 to 10 cm, (d) compensator thickness, ranged from 0 to 20 cm, and (e) depth, ranged from 7 to 15 cm. Second, dose calculations were computed in a virtual water phantom using the XiO TPS with pencil beam algorithm for identical beam conditions and geometrical configurations that were used for the measurements. The calculated lateral penumbra was then compared with the measured one for both the horizontal and vertical scanning magnets of our uniform scanning proton beam delivery system.Results: The results in the current study showed that the lateral penumbra of horizontal scanning magnet was larger (up to 1.4 mm for measurement and up to 1.0 mm for TPS) compared to that of vertical scanning magnet. Both the TPS and measurements showed an almost linear increase in lateral penumbra with increasing air gap as it produced the greatest effect on lateral penumbra. Lateral penumbra was dependent on the depth and proton range. Specifically, the width of lateral penumbra was found to be always lower at shallower depth than at deeper depth within the spread out Bragg peak (SOBP) region. The lateral penumbra results were less sensitive to the variation in the thickness of compensator, whereas lateral penumbra was independent of modulation. Overall, the comparison between the results of TPS with that of measurements indicates a good agreement for lateral penumbra, with TPS predicting higher values compared to

  3. Synergistic effect of casein glycomacropeptide on sodium caseinate foaming properties.

    Science.gov (United States)

    Morales, R; Martinez, M J; Pilosof, A M R

    2017-11-01

    Several strategies to improve the interfacial properties and foaming properties of proteins may be developed; among them, the use of mixtures of biopolymers that exhibit synergistic interactions. The aim of the present work was to evaluate the effect of casein glycomacropeptide (CMP) on foaming and surface properties of sodium caseinate (NaCas) and to establish the role of protein interactions in the aqueous phase. To this end particles size, interfacial and foaming properties of CMP, NaCas and NaCas-CMP mixtures at pH 5.5 and 7 were determined. At both pH, the interaction between CMP and NaCas induced a decrease in the aggregation state of NaCas. Single CMP foams showed the highest and NaCas the lowest foam overrun (FO) and the mixture exhibited intermediate values. CMP foam quickly drained. The drainage profile of mixed foams was closer to NaCas foams; at pH 5.5, mixed foams drained even slower than NaCas foam, exhibiting a synergistic performance. Additionally, a strong synergism was observed on the collapse of mixed foams at pH 5.5. Finally, a model to explain the synergistic effect observed on foaming properties in CMP-NaCas mixtures has been proposed; the reduced aggregation state of NaCas in the presence of CMP, made it more efficient for foam stabilization. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. H1259 Container Foams: Performance Data on Aged Materials

    International Nuclear Information System (INIS)

    Linda Domeier

    2002-01-01

    Samples of the three cushioning foams used in the H1259 weapon storage container were obtained in 1997, 1998, 2000 and 2001 and tested for density, compression set and compressive strength using the same procedures specified for acceptance testing. Foams from six containers, all about 30 years old and located at Pantex, were evaluated. The bottom cushioning foam is a General Plastics polyurethane foam and the two side pads are rebonded polyurethane foams. All the tests were carried out at room temperature. When compared to the original acceptance requirements the foams were generally in-spec for density and compressive strength at 10% strain and were generally out-of-spec for compression set and compressive strength at 50% strain. Significant variability was noted in the performance of each foam sample and even more in the container-to-container foam performance. The container-to-container variability remains the major unknown in predicting the long-term suitability of these containers for continued use. The performance of the critical bottom cushion foams was generally more uniform and closer to the specified performance than that of the rebonded foams. It was judged that all the foams were adequate for continued use as storage container foams (not shipping) under controlled conditions to mitigate temperature extremes or high impact. This archived information is important in evaluations of the continued suitability for weapon storage use of the H1259 containers and other containers using the same foam cushions

  5. Fire-Induced Response in Foam Encapsulants

    Energy Technology Data Exchange (ETDEWEB)

    Borek, T.T.; Chu, T.Y.; Erickson, K.L.; Gill, W.; Hobbs, M.L.; Humphries, L.L.; Renlund, A.M.; Ulibarri, T.A.

    1999-04-02

    The paper provides a concise overview of a coordinated experimental/theoretical/numerical program at Sandia National Laboratories to develop an experimentally validated model of fire-induced response of foam-filled engineered systems for nuclear and transportation safety applications. Integral experiments are performed to investigate the thermal response of polyurethane foam-filled systems exposed to fire-like heat fluxes. A suite of laboratory experiments is performed to characterize the decomposition chemistry of polyurethane. Mass loss and energy associated with foam decomposition and chemical structures of the virgin and decomposed foam are determined. Decomposition chemistry is modeled as the degradation of macromolecular structures by bond breaking followed by vaporization of small fragments of the macromolecule with high vapor pressures. The chemical decomposition model is validated against the laboratory data. Data from integral experiments is used to assess and validate a FEM foam thermal response model with the chemistry model developed from the decomposition experiments. Good agreement was achieved both in the progression of the decomposition front and the in-depth thermal response.

  6. Headspace analysis of foams and fixatives

    Energy Technology Data Exchange (ETDEWEB)

    Harper, Kyle [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Truong, Thanh-Tam [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Magwood, Leroy [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peters, Brent [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nicholson, James [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-27

    In the process of decontaminating and decommissioning (D&D) older nuclear facilities, special precautions must be taken with removable or airborne contamination. One possible strategy utilizes foams and fixatives to affix these loose contaminants. Many foams and fixatives are already commercially available, either generically or sold specifically for D&D. However, due to a lack of revelant testing in a radioactive environment, additional verification is needed to confirm that these products not only affix contamination to their surfaces, but also will function in a D&D environment. Several significant safety factors, including flammability and worker safety, can be analyzed through the process of headspace analysis, a technique that analyzes the off gas formed before or during the curing process of the foam/fixative, usually using gas chromatography-mass spectrometry (GC-MS). This process focuses on the volatile components of a chemical, which move freely between the solid/liquid form within the sample and the gaseous form in the area above the sample (the headspace). Between possibly hot conditions in a D&D situation and heat created in a foaming reaction, the volatility of many chemicals can change, and thus different gasses can be released at different times throughout the reaction. This project focused on analysis of volatile chemicals involved in the process of using foams and fixatives to identify any potential hazardous or flammable compounds.

  7. Inflatable Tubular Structures Rigidized with Foams

    Science.gov (United States)

    Tinker, Michael L.; Schnell, Andrew R.

    2010-01-01

    Inflatable tubular structures that have annular cross sections rigidized with foams, and the means of erecting such structures in the field, are undergoing development. Although the development effort has focused on lightweight structural booms to be transported in compact form and deployed in outer space, the principles of design and fabrication are also potentially applicable to terrestrial structures, including components of ultralightweight aircraft, lightweight storage buildings and shelters, lightweight insulation, and sales displays. The use of foams to deploy and harden inflatable structures was first proposed as early as the 1960s, and has been investigated in recent years by NASA, the U.S. Air Force Research Laboratory, industry, and academia. In cases of deployable booms, most of the investigation in recent years has focused on solid cross sections, because they can be constructed relatively easily. However, solid-section foam-filled booms can be much too heavy for some applications. In contrast, booms with annular cross sections according to the present innovation can be tailored to obtain desired combinations of stiffness and weight through choice of diameters, wall thicknesses, and foam densities. By far the most compelling advantage afforded by this innovation is the possibility of drastically reducing weights while retaining or increasing the stiffnesses, relative to comparable booms that have solid foamfilled cross sections. A typical boom according to this innovation includes inner and outer polyimide film sleeves to contain foam that is injected between them during deployment.

  8. Fabrication of Foam Shells for ICF Experiments

    Science.gov (United States)

    Czechowicz, D. G.; Acenas, O.; Flowers, J. S.; Nikroo, A.; Paguio, R. R.; Schroen, D. G.; Streit, J.; Takagi, M.

    2004-11-01

    The General Atomics/Schafer team has developed processes to fabricate foam shells targets suitable for ICF experiments. The two most common chemical systems used to produce foam shells have been resorcinol-formaldehyde (R/F) aerogel and divinylbenzene (DVB). Spherical targets have been made in the form of shells and beads having diameters ranging from approximately 0.5 mm to 4.0 mm, and having densities from approximately 100 mg/cc to 250 mg/cc. The work on R/F foam shells has been concentrated on 1) shell fabrication process improvement to obtain high yields ( ˜25%) and 2) depositing a reliable permeation barrier to provide shells for ongoing direct drive experiments at LLE. Development of divinylbenzene foam shells has been mainly directed towards Inertial Fusion Energy applications (at densities as low as 30 mg/cc) and recently for shells for experiments at LLE. Details of the relevant metrology and properties of these foams as well as the range of targets currently available will be discussed.

  9. The dynamics of diffracted rays in foams

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail: tufaile@usp.br; Tufaile, A.P.B.

    2015-12-18

    We have studied some aspects of the optics of the light scattering in foams. This paper describes the difference between rays and diffracted rays from the point of view of geometrical theory of diffraction. We have represented some bifurcations of light rays using dynamical systems. Based on our observations of foams, we created a solid optical device. The interference patterns of light scattering in foams forming Airy fringes were explored observing the pattern named as the eye of Horus. In the cases we examine, these Airy fringes are associated with light scattering in curved surfaces, while the halo formation is related to the law of edge diffraction. We are proposing a Pohl interferometer using a three-sided bubble/Plateau border system. - Highlights: • We obtained halos scattering light in foams. • We model the light scattering in foams using the geometrical theory of diffraction. • We examine the difference between rays and the diffracted rays. • We developed optical devices for diffracted rays.

  10. Time-dependent crashworthiness of polyurethane foam

    Science.gov (United States)

    Basit, Munshi Mahbubul; Cheon, Seong Sik

    2018-05-01

    Time-dependent stress-strain relationship as well as crashworthiness of polyurethane foam was investigated under constant impact energy with different velocities, considering inertia and strain-rate effects simultaneously during the impact testing. Even though the impact energies were same, the percentage in increase in densification strain due to higher impact velocities was found, which yielded the wider plateau region, i.e. growth in crashworthiness. This phenomenon is analyzed by the microstructure of polyurethane foam obtained from scanning electron microscopy. The equations, coupled with the Sherwood-Frost model and the impulse-momentum theory, were employed to build the constitutive equation of the polyurethane foam and calculate energy absorption capacity of the foam. The nominal stress-strain curves obtained from the constitutive equation were compared with results from impact tests and were found to be in good agreement. This study is dedicated to guiding designer use polyurethane foam in crashworthiness structures such as an automotive bumper system by providing crashworthiness data, determining the crush mode, and addressing a mathematical model of the crashworthiness.

  11. Optimized Synthesis of Foam Glass from Recycled CRT Panel Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    Most of the panel glass from cathode ray tubes (CRTs) is landfilled today. Instead of landfilling, the panel glass can be turned into new environment-friendly foam glass. Low density foam glass is an effective heat insulating material and can be produced just by using recycle glass and foaming...... additives. In this work we recycle the CRT panel glass to synthesize the foam glass as a crucial component of building and insulating materials. The synthesis conditions such as foaming temperature, duration, glass particle size, type and concentrations of foaming agents, and so on are optimized...... by performing systematic experiments. In particular, the concentration of foaming agents is an important parameter that influences the size of bubbles and the distribution of bubbles throughout the sample. The foam glasses are characterised regarding density and open/closed porosity. Differential scanning...

  12. Compact assembly generates plastic foam, inflates flotation bag

    Science.gov (United States)

    1965-01-01

    Device for generating plastic foam consists of an elastomeric bag and two containers with liquid resin and a liquid catalyst. When the walls of the containers are ruptured the liquids come into contact producing foam which inflates the elastomeric bag.

  13. METHODS OF REDUCTION OF FREE PHENOL CONTENT IN PHENOLIC FOAM

    Directory of Open Access Journals (Sweden)

    Bruyako Mikhail Gerasimovich

    2012-12-01

    method aimed at reduction of toxicity of phenolic foams consists in the introduction of a composite mixture of chelate compounds. Raw materials applied in the production of phenolic foams include polymers FRB-1A and VAG-3. The aforementioned materials are used to produce foams FRP-1. Introduction of 1% aluminum fluoride leads to the 40% reduction of the free phenol content in the foam. Introduction of crystalline zinc chloride accelerates the foaming and curing of phenolic foams. The technology that contemplates the introduction of zeolites into the mixture includes pre-mixing with FRB -1A and subsequent mixing with VAG-3; thereafter, the composition is poured into the form, in which the process of foaming is initiated. The content of free phenol was identified using the method of UV spectroscopy. The objective of the research was to develop methods of reduction of the free phenol content in the phenolic foam.

  14. Mechanical Properties of Electrolyte Jet Electrodeposited Nickel Foam

    Directory of Open Access Journals (Sweden)

    Jinsong Chen

    2013-07-01

    Full Text Available Principles of the preparation of nickel foam by electrolyte jet electrodeposition were introduced, Nickel foam samples with different porosity were fabricated. Effect of different porosity on microhardness and uniaxial tensile properties of nickel foam was discussed. The results show that the microhardness of nickel foam is 320~400 HV, lower than entitative metal clearly. The lower the porosity of nickel foam, the higher the microhardness is. During the process of uniaxial tensile, nickel foam is characterized by three distinct regions, e.g. elastic deforming region, plastic plateau region and densification region. The higher the porosity of nickel foam, the lower the plastic plateau and the poorer the strength of nickel foam, accordingly

  15. Electrical conductivity of quasi-two-dimensional foams.

    Science.gov (United States)

    Yazhgur, Pavel; Honorez, Clément; Drenckhan, Wiebke; Langevin, Dominique; Salonen, Anniina

    2015-04-01

    Quasi-two-dimensional (quasi-2D) foams consist of monolayers of bubbles squeezed between two narrowly spaced plates. These simplified foams have served successfully in the past to shed light on numerous issues in foam physics. Here we consider the electrical conductivity of such model foams. We compare experiments to a model which we propose, and which successfully relates the structural and the conductive properties of the foam over the full range of the investigated liquid content. We show in particular that in the case of quasi-2D foams the liquid in the nodes needs to be taken into account even at low liquid content. We think that these results may provide different approaches for the characterization of foam properties and for the in situ characterization of the liquid content of foams in confining geometries, such as microfluidics.

  16. Design and evaluation of foamed asphalt base materials.

    Science.gov (United States)

    2013-05-01

    Foamed asphalt stabilized base (FASB) combines reclaimed asphalt pavement (RAP), recycled : concrete (RC), and/or graded aggregate base (GAB) with a foamed asphalt binder to produce a : partially stabilized base material. The objectives of this study...

  17. Comparison of shape memory polymer foam versus bare metal coil treatments in an in vivo porcine sidewall aneurysm model.

    Science.gov (United States)

    Horn, John; Hwang, Wonjun; Jessen, Staci L; Keller, Brandis K; Miller, Matthew W; Tuzun, Egemen; Hartman, Jonathan; Clubb, Fred J; Maitland, Duncan J

    2017-10-01

    The endovascular delivery of platinum alloy bare metal coils has been widely adapted to treat intracranial aneurysms. Despite the widespread clinical use of this technique, numerous suboptimal outcomes are possible. These may include chronic inflammation, low volume filling, coil compaction, and recanalization, all of which can lead to aneurysm recurrence, need for retreatment, and/or potential rupture. This study evaluates a treatment alternative in which polyurethane shape memory polymer (SMP) foam is used as an embolic aneurysm filler. The performance of this treatment method was compared to that of bare metal coils in a head-to-head in vivo study utilizing a porcine vein pouch aneurysm model. After 90 and 180 days post-treatment, gross and histological observations were used to assess aneurysm healing. At 90 days, the foam-treated aneurysms were at an advanced stage of healing compared to the coil-treated aneurysms and showed no signs of chronic inflammation. At 180 days, the foam-treated aneurysms exhibited an 89-93% reduction in cross-sectional area; whereas coiled aneurysms displayed an 18-34% area reduction. The superior healing in the foam-treated aneurysms at earlier stages suggests that SMP foam may be a viable alternative to current treatment methods. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1892-1905, 2017. © 2016 Wiley Periodicals, Inc.

  18. Preparation and characterization of PMMA graded microporous foams via one-step supercritical carbon dioxide foaming

    International Nuclear Information System (INIS)

    Yuan Huan; Li Junguo; Xiong Yuanlu; Luo Guoqiang; Shen Qiang; Zhang Lianmeng

    2013-01-01

    Supercritical carbon dioxide (ScCO 2 ) foaming which is inexpensive and environmental friendly has been widely used to prepare polymer-based microporous materials. In this paper, PMMA graded microporous materials were foamed by PMMA matrix after an unstable saturation process which was done under supercritical condition of 28MPa and 50 °C. The scanning electron microscopy (SEM) was utilized to observe the morphology of the graded foam. A gas adsorption model was proposed to predict the graded gas concentration in the different region of the polymer matrix. The SEM results showed that the solid and foam region of the graded foam can be connected without laminated layers. With the increasing thickness position of the graded microporous foam, the cell size increased from 3.4 to 27.5 μm, while the cell density decreased from 1.04 × 10 9 to 1.96 × 10 7 cells/cm 3 . It also found that the gradient microporous structure of the foam came from graded gas concentration which was obtained in the initial saturation process.

  19. Foamed emulsion drainage: flow and trapping of drops

    OpenAIRE

    Schneider, Maxime; Zou, Ziqiang; Langevin, Dominique; Salonen, Anniina

    2017-01-01

    Foamed emulsions are ubiquitous in our daily life but the ageing of such systems is still poorly understood. In this study we investigate foam drainage and measure the evolution of the gas, liquid and oil volume fractions inside the foam. We evidence three regimes of ageing. During an initial period of fast drainage, both bubbles and drops are very mobile. As the foam stabilises drainage proceeds leading to a gradual decrease of the liquid fraction and slowing down of drainage. Clusters of oi...

  20. Studies on flame retardancy of radiation crosslinked PE foam

    International Nuclear Information System (INIS)

    Yang Huili; Yao Zhanhai; Xu Jun

    1996-01-01

    CPE, DBDPO and Sb 2 O 3 were used as flame-retardant of PE foam. Effect of CPE on PE foam under radiation and it's flame-retardancy were studied. The result showed that CPE can enhance radiation cross-linking of PE, and trinary of addition being made of CPE, DBDPO and Sb 2 O 3 made oxygen index of PE foam achieve over 30, and self-extinguish, it did not influence manufacture and mechanical properties of PE foam

  1. Small core flood experiments for foam EOR: Screening surfactant applications

    OpenAIRE

    Jones, S.A.; Van der Bent, V.; Farajzadeh, R.; Rossen, W.R.; Vincent-Bonnieu, S.

    2015-01-01

    Aqueous foams are a means of increasing the sweep efficiency of enhanced oil recovery processes. An understanding of how a foam behaves in the presence of oil is therefore of great importance when selecting suitable surfactants for EOR processes. The consensus is currently that the most reliable method for determining the foam behavior in the presence of oil is to inject foam through a rock core. Coreflood tests, however, are typically carried out using large rock cores (e.g. diameter = 4 cm,...

  2. Effectiveness of Flame Retardants in TufFoam.

    Energy Technology Data Exchange (ETDEWEB)

    Abelow, Alexis Elizabeth [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Nissen, April [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Massey, Lee Taylor [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Whinnery, LeRoy L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-12-01

    An investigation of polyurethane foam filled with known flame retardant fillers including hydroxides, melamine, phosphate-containing compounds, and melamine phosphates was carried out to produce a low-cost material with high flame retardant efficiency. The impact of flame retardant fillers on the physical properties such a s composite foam density, glass transition temperature, storage modulus, and thermal expansion of composite foams was investigated with the goal of synthesizing a robust rigid foam with excellent flame retardant properties.

  3. Modyfication of the Rigid Polyurethane-Polyisocyanurate Foams

    OpenAIRE

    Bogusław Czupryński; Joanna Liszkowska; Joanna Paciorek-Sadowska

    2014-01-01

    The effect of polyethylene glycol 1500 on physicomechanical properties of rigid polyurethane-polyisocyanurate (PUR-PIR) foams has been studied. It was found that application of polyethylene glycol 1500 for synthesis of foams in amount from 0% to 20% w/w had an effect on reduction of brittleness and softening point, while the greater the increase in compressive strength the higher its content in foam composition was. Wastes from production of these foams were ground and subjected to glycolysis...

  4. Ultra Low Density Shape Memory Polymer Foams With Tunable Physicochemical Properties for Treatment of intracranial Aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Singhal, Pooja [Texas A & M Univ., College Station, TX (United States)

    2013-12-01

    Shape memory polymers (SMPs) are a rapidly emerging class of smart materials that can be stored in a deformed temporary shape, and can actively return to their original shape upon application of an external stimulus such as heat, pH or light. This behavior is particularly advantageous for minimally invasive biomedical applications comprising embolic/regenerative scaffolds, as it enables a transcatheter delivery of the device to the target site. The focus of this work was to exploit this shape memory behavior of polyurethanes, and develop an efficient embolic SMP foam device for the treatment of intracranial aneurysms.In summary, this work reports a novel family of ultra low density polymer foams which can be delivered via a minimally invasive surgery to the aneurysm site, actuated in a controlled manner to efficiently embolize the aneurysm while promoting physiological fluid/blood flow through the reticulated/open porous structure, and eventually biodegrade leading to complete healing of the vasculature.

  5. Evaluation of Canisterized Foams and Evaluation of Radiation Hardened Foams for D&D Activities

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson, J. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-26

    The introduction of polyurethane foams has previously been examined elsewhere within the DOE complex with regards to decontamination and decommissioning (D&D) activities, though its use has been prohibited as a result of excessive heat generation and flammability concerns per the safety basis. Should these foams be found compatible with respect to the facility safety basis requirements, D&D work involving large void containing structures such as gloveboxes could be eased through the fixation of residual contamination after decontamination efforts have concluded. To this end, SRNL embarked on a characterization of commercial epoxy foams to identify the characteristics that would be most important to safety basis requirements. Through SRNL’s efforts, the performance of commercial two-part epoxy foams was evaluated for their foaming characteristics, temperature profiles, loading capability with high-Z (high density) additives, and applicability for shielding gamma emission from isotopes including; Am-241, Cs-137, and Co-60. It was found that these foams are capable of encapsulation of a desired volume, though the ideal and experimental expansion coefficients were found to differ. While heat is generated during the reaction, no samples generated heat above 70 °C. Of the down–selected materials, heating was on the order of 40 °C for the flexible foam and 60 °C for the rigid foam. Both were found to return to room temperature after 20 minutes regardless of the volume of foam cast. It was also found that the direct introduction of high-Z additives were capable of attenuating 98% of Am-241 gamma signal, 16% of Cs-137 signal, and 9.5% of Co-60 signal at 1:1 loading capacities of total liquid constituent weight to additive weight. These efforts are currently being reviewed for the ASTM January 2017 subcommittee discussions to address the lack of test methods and standards regarding these materials with respect to D&D environments.

  6. Experiments to Populate and Validate a Processing Model for Polyurethane Foam: Additional Data for Structural Foams

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Rekha R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Celina, Mathias C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Giron, Nicholas Henry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Long, Kevin Nicholas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Russick, Edward M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    We are developing computational models to help understand manufacturing processes, final properties and aging of structural foam, polyurethane PMDI. Th e resulting model predictions of density and cure gradients from the manufacturing process will be used as input to foam heat transfer and mechanical models. BKC 44306 PMDI-10 and BKC 44307 PMDI-18 are the most prevalent foams used in structural parts. Experiments needed to parameterize models of the reaction kinetics and the equations of motion during the foam blowing stages were described for BKC 44306 PMDI-10 in the first of this report series (Mondy et al. 2014). BKC 44307 PMDI-18 is a new foam that will be used to make relatively dense structural supports via over packing. It uses a different catalyst than those in the BKC 44306 family of foams; hence, we expect that the reaction kineti cs models must be modified. Here we detail the experiments needed to characteriz e the reaction kinetics of BKC 44307 PMDI-18 and suggest parameters for the model based on these experiments. In additi on, the second part of this report describes data taken to provide input to the preliminary nonlinear visco elastic structural response model developed for BKC 44306 PMDI-10 foam. We show that the standard cu re schedule used by KCP does not fully cure the material, and, upon temperature elevation above 150°C, oxidation or decomposition reactions occur that alter the composition of the foam. These findings suggest that achieving a fully cured foam part with this formulation may be not be possible through therma l curing. As such, visco elastic characterization procedures developed for curing thermosets can provide only approximate material properties, since the state of the material continuously evolves during tests.

  7. Foam flows through a local constriction

    Science.gov (United States)

    Chevalier, T.; Koivisto, J.; Shmakova, N.; Alava, M. J.; Puisto, A.; Raufaste, C.; Santucci, S.

    2017-11-01

    We present an experimental study of the flow of a liquid foam, composed of a monolayer of millimetric bubbles, forced to invade an inhomogeneous medium at a constant flow rate. To model the simplest heterogeneous fracture medium, we use a Hele-Shaw cell consisting of two glass plates separated by a millimetric gap, with a local constriction. This single defect localized in the middle of the cell reduces locally its gap thickness, and thus its local permeability. We investigate here the influence of the geometrical property of the defect, specifically its height, on the average steady-state flow of the foam. In the frame of the flowing foam, we can observe a clear recirculation around the obstacle, characterized by a quadrupolar velocity field with a negative wake downstream the obstacle, which intensity evolves systematically with the obstacle height.

  8. Domain growth kinetics in stratifying foam films

    Science.gov (United States)

    Zhang, Yiran; Sharma, Vivek

    2015-11-01

    Baking bread, brewing cappuccino, pouring beer, washing dishes, shaving, shampooing, whipping eggs and blowing bubbles all involve creation of aqueous foam films. Typical foam films consist of two surfactant-laden surfaces that are ~ 5 nm - 10 micron apart. Sandwiched between these interfacial layers is a fluid that drains primarily under the influence of viscous and interfacial forces, including disjoining pressure. Interestingly, a layered ordering of micelles inside the foam films (thickness characteristic scaling laws. Though several studies have focused on the expansion dynamics of isolated domains that exhibit a diffusion-like scaling, the change in expansion kinetics observed after domains contact with the Plateau border has not been reported and analyzed before.

  9. Insulating Foams Save Money, Increase Safety

    Science.gov (United States)

    2009-01-01

    Scientists at Langley Research Center created polyimide foam insulation for reusable cryogenic propellant tanks on the space shuttle. Meanwhile, a small Hialeah, Florida-based business, PolyuMAC Inc., was looking for advanced foams to use in the customized manufacturing of acoustical and thermal insulation. The company contacted NASA, licensed the material, and then the original inventors worked with the company's engineers to make a new material that was better for both parties. The new version, a high performance, flame retardant, flexible polyimide foam, is used for insulating NASA cryogenic propellant tanks and shows promise for use on watercraft, aircraft, spacecraft, electronics and electrical products, automobiles and automotive products, recreation equipment, and building and construction materials.

  10. Foam insulated transfer line test report

    International Nuclear Information System (INIS)

    Squier, D.M.

    1994-06-01

    Miles of underground insulated piping will be installed at the Hanford site to transfer liquid waste. Significant cost savings may be realized by using pre-fabricated polyurethane foam insulated piping. Measurements were made on sections of insulated pipe to determine the insulation's resistance to axial expansion of the pipe, the force required to compress the foam in the leg of an expansion loop and the time required for heat up and cool down of a buried piping loop. These measurements demonstrated that the peak axial force increases with the amount of adhesion between the encasement pipe and the insulation. The compressive strength of the foam is too great to accommodate the thermal growth of long straight pipe sections into the expansion loops. Mathematical models of the piping system's thermal behavior can be refined by data from the heated piping loop

  11. Plastic Foam Withstands Greater Temperatures And Pressures

    Science.gov (United States)

    Cranston, John A.; Macarthur, Doug

    1993-01-01

    Improved plastic foam suitable for use in foam-core laminated composite parts and in tooling for making fiber/matrix-composite parts. Stronger at high temperatures, more thermally and dimensionally stable, machinable, resistant to chemical degradation, and less expensive. Compatible with variety of matrix resins. Made of polyisocyanurate blown with carbon dioxide and has density of 12 to 15 pounds per cubic feet. Does not contibute to depletion of ozone from atmosphere. Improved foam used in cores of composite panels in such diverse products as aircraft, automobiles, railroad cars, boats, and sporting equipment like surfboards, skis, and skateboards. Also used in thermally stable flotation devices in submersible vehicles. Machined into mandrels upon which filaments wound to make shells.

  12. CFC alternatives for thermal insulation foams

    Energy Technology Data Exchange (ETDEWEB)

    Shankland, I.R. (Allied-Signal Inc., Buffalo, NY (US))

    1990-03-01

    Low density polymeric foam materials expanded with chlorofluorocarbon (CFC) blowing agents have found widespread use as highly efficient thermal insulation materials in the construction, refrigeration appliance and transportation industries. The advent of regulations which are reducing the production and consumption of the fully halogenated CFCs for environmental reasons has prompted the development of environmentally acceptable substitutes for the CFC blowing agents. This paper summarizes the physical properties and performance of the leading alternatives for CFC-11, which is used to expand rigid polyurethane and polyisocyanurate foams, and the leading alternatives for CFC-12 which is used to expand extruded polystyrene board foam. Although the alternatives, HCFC-123 and HCFC-14lb for CFC-11 and HCFC142b and HCFC-124 for CFC-12, are not perfect matches from the performance viewpoint, they represent the optimum choice given the constraints on environmental acceptability, toxicity, flammability and performance. (author).

  13. Foam Fractionation of Lycopene: An Undergraduate Chemistry Experiment

    Science.gov (United States)

    Wang, Yan; Zhang, Mingjie; Hu, Yongliang

    2010-01-01

    A novel experiment for the extraction of lycopene from tomato paste by foam fractionation is described. Foam fractionation is a process for separating and concentrating chemicals by utilizing differences in their surface activities. Extraction of lycopene by foam fractionation is a new method that has not been previously reported in the…

  14. Foam for Enhanced Oil Recovery : Modeling and Analytical Solutions

    NARCIS (Netherlands)

    Ashoori, E.

    2012-01-01

    Foam increases sweep in miscible- and immiscible-gas enhanced oil recovery by decreasing the mobility of gas enormously. This thesis is concerned with the simulations and analytical solutions for foam flow for the purpose of modeling foam EOR in a reservoir. For the ultimate goal of upscaling our

  15. Thermomechanical analyses of phenolic foam reinforced with glass fiber mat

    International Nuclear Information System (INIS)

    Zhou, Jintang; Yao, Zhengjun; Chen, Yongxin; Wei, Dongbo; Wu, Yibing

    2013-01-01

    Highlights: • Over 10% glass fiber was used to reinforce phenolic foam in the shape of glass fiber mat. • Nucleating agents were used together with glass fiber mat and improved tensile strength of phenolic foam by 215.6%. • Nucleating agents lead to a smaller bubble size of phenolic foam. • The glass transition temperature of phenolic foam remained unchanged during the reinforcement. - Abstract: In this paper, thermomechanical analysis (TMA) and dynamic mechanical analysis were employed to study the properties of phenolic foam reinforced with glass fiber mat. Unreinforced phenolic foam was taken as the control sample. Mechanical tests and scanning electron microscopy were performed to confirm the results of TMA. The results show that glass fiber mat reinforcement improves the mechanical performance of phenolic foam, and nucleating agents improve it further. Phenolic foam reinforced with glass fiber mat has a smaller thermal expansion coefficient compared with unreinforced foam. The storage modulus of the reinforced phenolic foam is also higher than that in unreinforced foam, whereas the loss modulus of the former is lower than that of the latter. The glass transition temperature of the phenolic foam matrix remains unchanged during the reinforcement

  16. Floating matrix tablets based on low density foam powder: effects of formulation and processing parameters on drug release.

    Science.gov (United States)

    Streubel, A; Siepmann, J; Bodmeier, R

    2003-01-01

    The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i). polypropylene foam powder, (ii). matrix-forming polymer(s), (iii). drug, and (iv). filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 degrees C. Different types of matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of matrix former. The release rate could effectively be modified by varying the "matrix-forming polymer/foam powder" ratio, the initial drug loading, the tablet geometry (radius and height), the type of matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.

  17. Outgassing From Open And Closed Magma Foams

    Science.gov (United States)

    von Aulock, Felix W.; Kennedy, Ben M.; Maksimenko, Anton; Wadsworth, Fabian B.; Lavallée, Yan

    2017-06-01

    During magma ascent, bubbles nucleate, grow, coalesce, and form a variably permeable porous network. The volcanic system opens and closes as bubble walls reorganize, seal or fail. In this contribution we cause obsidian to nucleate and grow bubbles to high gas volume fraction at atmospheric pressure by heating samples to 950 ºC for different times and we image the growth through a furnace. Following the experiment, we imaged the internal pore structure of selected samples in 3D and then dissected for analysis of textures and dissolved water content remnant in the glass. We demonstrate that in these high viscosity systems, during foaming and subsequent foam-maturation, bubbles near a free surface resorb via diffusion to produce an impermeable skin of melt around a foam. The skin thickens nonlinearly through time. The water concentrations at the outer and inner skin margins reflect the solubility of water in the melt at the partial pressure of water in atmospheric and water-rich bubble conditions, respectively. In this regime, mass transfer of water out of the system is diffusion limited and the sample shrinks slowly. In a second set of experiments in which we polished off the skin of the foamed samples and placed them back in the furnace, we observe rapid sample contraction and collapse of the connected pore network under surface tension as the system efficiently outgasses. In this regime, mass transfer of water is permeability limited. The mechanisms described here are relevant to the evolution of pore network heterogeneity in permeable magmas. We conclude that diffusion-driven skin formation can efficiently seal connectivity in foams. When rupture of melt film around gas bubbles (i.e. skin removal) occurs, then rapid outgassing and consequent foam collapse modulate gas pressurisation in the vesiculated magma.

  18. Molded ultra-low density microcellular foams

    International Nuclear Information System (INIS)

    Rand, P.B.; Montoya, O.J.

    1986-07-01

    Ultra-low density (< 0.01 g/cc) microcellular foams were required for the NARYA pulsed-power-driven x-ray laser development program. Because of their extreme fragility, molded pieces would be necessary to successfully field these foams in the pulsed power accelerator. All of the foams evaluated were made by the thermally induced phase separation technique from solutions of water soluble polymers. The process involved rapidly freezing the solution to induce the phase separation, and then freeze drying to remove the water without destroying the foam's structure. More than sixty water soluble polymers were evaluated by attempting to make their solutions into foams. The foams were evaluated for shrinkage, density, and microstructure to determine their suitability for molding and meeting the required density and cell size requirements of 5.0 mg/cc and less than twenty μmeters. Several promising water soluble polymers were identified including the polyactylic acids, guar gums, polyactylamide, and polyethylene oxide. Because of thier purity, structure, and low shrinkage, the polyacrylic acids were chosen to develop molding processes. The initial requirements were for 2.0 cm. long molded rods with diameters of 1.0, 2.0. and 3.0 mm. These rods were made by freezing the solution in thin walled silicon rubber molds, extracting the frozen preform from the mold, and then freeze drying. Requirements for half rods and half annuli necessitated using aluminum molds. Again we successfully molded these shapes. Our best efforts to date involve molding annuli with 3.0 mm outside diameters and 2.0 mm inside diameters

  19. Outgassing from Open and Closed Magma Foams

    Directory of Open Access Journals (Sweden)

    Felix W. von Aulock

    2017-06-01

    Full Text Available During magma ascent, bubbles nucleate, grow, coalesce, and form a variably permeable porous network. The reorganization, failing and sealing of bubble walls may contribute to the opening and closing of the volcanic system. In this contribution we cause obsidian to nucleate and grow bubbles to high gas volume fraction at atmospheric pressure by heating samples to 950°C for different times and we image the growth through a furnace. Following the experiment, we imaged the internal pore structure of selected samples in 3D and then dissected for analysis of textures and dissolved water content remnant in the glass. We demonstrate that in these high viscosity systems, during foaming and subsequent foam-maturation, bubbles near a free surface resorb via diffusion to produce an impermeable skin of melt around a foam. The skin thickens non-linearly through time. The water concentrations at the outer and inner skin margins reflect the solubility of water in the melt at the partial pressure of water in atmospheric and water-rich bubble conditions, respectively. In this regime, mass transfer of water out of the system is diffusion limited and the sample shrinks slowly. In a second set of experiments in which we polished off the skin of the foamed samples and placed them back in the furnace to allow open system outgassing, we observe rapid sample contraction and collapse of the connected pore network under surface tension as the system efficiently outgasses. In this regime, mass transfer of water is permeability limited. We conclude that diffusion-driven skin formation can efficiently seal connectivity in foams. When rupture of melt film around gas bubbles (i.e., skin removal occurs, then rapid outgassing and consequent foam collapse modulate gas pressurization in the vesiculated magma. The mechanisms described here are relevant to the evolution of pore network heterogeneity in permeable magmas.

  20. Foam, composition and method of production

    Energy Technology Data Exchange (ETDEWEB)

    Ghali, R.

    1991-09-03

    A ternary foam is disclosed which overcomes the disadvantages of conventional heat-insulating foams which are either dense and heavy, expensive to produce, friable, unstable, or have poor fire resistance. The foam of the invention has, by weight of the reaction product, 10-35% polyurethane, 30-55% polyisocyanurate, and 20-45% polyurea. The foam is a reaction product of 100 parts by weight of an organic polyisocyanate with: 15-25 parts by weight of a polyether polyol having a hydroxyl number of ca 28-35 and a molecular weight of not more than 6,000; 5-25 parts by weight of water; 0-25 parts by weight of a blowing agent; 0-50 parts by weight of a filler-plasticizer fire retardant; an effective amount of a low activation catalyst to initiate water-isocyanate reaction to produce polyurea and polyol-isocyanate reaction to produce polyurethane; and an effective amount of a high activation catalyst to retard the low activation catalyst and promote the formation of polyisocyanurate. The low activity catalyst is present in an amount ranging ca 1.5-9 parts per 100 parts by weight of the polyisocyanate, and the high activation catalyst is present in an amount ranging 0.0008-0.002 parts per 100 parts by weight of the polyisocyanate. Water as a reactant and blowing agent can be substituted by an effective amount of a disubstituted amine such as diethanol amine and an inert blowing agent such as fluorocarbon. The resultant foam has excellent heat insulating propeties, is semi-flexible, has a density of 0.5-0.9 lb/ft{sup 3}, and can be inexpensively produced by existing 2-component foam dispensing equipment. 1 fig., 1 tab.

  1. Carbon foams from coals. A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Montserrat Calvo; Roberto Garcia; Ana Arenillas; Isabel Suarez; Sabino R. Moinelo [Instituto Nacional del Carbon (CSIC), Oviedo (Spain)

    2005-12-01

    Carbon foams were obtained from a bituminous coal with good plasticity properties by a two-stage thermal process under different pressure and temperature conditions. The first stage was a controlled carbonisation treatment under pressure at 450 and 500{sup o}C. In the second stage the carbonisation product was baked at 1100{sup o}C. The foams produced display a macroporous texture with pressure and temperature determining the mean pore size and the amount of pores. The pressure increase reduces the pore size, while the increasing temperature increases the pore volume. 10 refs., 6 figs., 3 tabs.

  2. Local Delivery of Fluorescent Dye For Fiber-Optics Confocal Microscopy of the Living Heart

    Directory of Open Access Journals (Sweden)

    Chao eHuang

    2014-09-01

    Full Text Available Fiber-optics confocal microscopy (FCM is an emerging imaging technology with various applications in basic research and clinical diagnosis. FCM allows for real-time in situ microscopy of tissue at sub-cellular scale. Recently FCM has been investigated for cardiac imaging, in particular, for discrimination of cardiac tissue during pediatric open-heart surgery. FCM relies on fluorescent dyes. The current clinical approach of dye delivery is based on systemic injection, which is associated with high dye consumption and adverse clinical events. In this study, we investigated approaches for local dye delivery during FCM imaging based on dye carriers attached to the imaging probe. Using three-dimensional confocal microscopy, automated bench tests, and FCM imaging we quantitatively characterized dye release of carriers composed of open-pore foam only and foam loaded with agarose hydrogel. In addition, we compared local dye delivery with a model of systemic dye delivery in the isolated perfused rodent heart. We measured the signal-to-noise ratio of images acquired in various regions of the heart. Our evaluations showed that foam-agarose dye carriers exhibited a prolonged dye release versus foam-only carriers. Foam-agarose dye carriers allowed reliable imaging of 5-9 lines, which is comparable to 4-8 min of continuous dye release. Our study in the living heart revealed that the SNR of FCM images using local and systemic dye delivery is not different. However, we observed differences in the imaged tissue microstructure with the two approaches. Structural features characteristic of microvasculature were solely observed for systemic dye delivery. Our findings suggest that local dye delivery approach for FCM imaging constitutes an important alternative to systemic dye delivery. We suggest that the approach for local dye delivery will facilitate clinical translation of FCM, for instance, for FCM imaging during pediatric heart surgery.

  3. Local delivery of fluorescent dye for fiber-optics confocal microscopy of the living heart.

    Science.gov (United States)

    Huang, Chao; Kaza, Aditya K; Hitchcock, Robert W; Sachse, Frank B

    2014-01-01

    Fiber-optics confocal microscopy (FCM) is an emerging imaging technology with various applications in basic research and clinical diagnosis. FCM allows for real-time in situ microscopy of tissue at sub-cellular scale. Recently FCM has been investigated for cardiac imaging, in particular, for discrimination of cardiac tissue during pediatric open-heart surgery. FCM relies on fluorescent dyes. The current clinical approach of dye delivery is based on systemic injection, which is associated with high dye consumption, and adverse clinical events. In this study, we investigated approaches for local dye delivery during FCM imaging based on dye carriers attached to the imaging probe. Using three-dimensional confocal microscopy, automated bench tests, and FCM imaging we quantitatively characterized dye release of carriers composed of open-pore foam only and foam loaded with agarose hydrogel. In addition, we compared local dye delivery with a model of systemic dye delivery in the isolated perfused rodent heart. We measured the signal-to-noise ratio (SNR) of images acquired in various regions of the heart. Our evaluations showed that foam-agarose dye carriers exhibited a prolonged dye release vs. foam-only carriers. Foam-agarose dye carriers allowed reliable imaging of 5-9 lines, which is comparable to 4-8 min of continuous dye release. Our study in the living heart revealed that the SNR of FCM images using local and systemic dye delivery is not different. However, we observed differences in the imaged tissue microstructure with the two approaches. Structural features characteristic of microvasculature were solely observed for systemic dye delivery. Our findings suggest that local dye delivery approach for FCM imaging constitutes an important alternative to systemic dye delivery. We suggest that the approach for local dye delivery will facilitate clinical translation of FCM, for instance, for FCM imaging during pediatric heart surgery.

  4. Experimental study on foam coverage on simulated longwall roof

    Science.gov (United States)

    Reed, W.R.; Zheng, Y.; Klima, S.; Shahan, M.R.; Beck, T.W.

    2018-01-01

    Testing was conducted to determine the ability of foam to maintain roof coverage in a simulated longwall mining environment. Approximately 27 percent of respirable coal mine dust can be attributed to longwall shield movement, and developing controls for this dust source has been difficult. The application of foam is a possible dust control method for this source. Laboratory testing of two foam agents was conducted to determine the ability of the foam to adhere to a simulated longwall face roof surface. Two different foam generation methods were used: compressed air and blower air. Using a new imaging technology, image processing and analysis utilizing ImageJ software produced quantifiable results of foam roof coverage. For compressed air foam in 3.3 m/s (650 fpm) ventilation, 98 percent of agent A was intact while 95 percent of agent B was intact on the roof at three minutes after application. At 30 minutes after application, 94 percent of agent A was intact while only 20 percent of agent B remained. For blower air in 3.3 m/s (650 fpm) ventilation, the results were dependent upon nozzle type. Three different nozzles were tested. At 30 min after application, 74 to 92 percent of foam agent A remained, while 3 to 50 percent of foam agent B remained. Compressed air foam seems to remain intact for longer durations and is easier to apply than blower air foam. However, more water drained from the foam when using compressed air foam, which demonstrates that blower air foam retains more water at the roof surface. Agent A seemed to be the better performer as far as roof application is concerned. This testing demonstrates that roof application of foam is feasible and is able to withstand a typical face ventilation velocity, establishing this technique’s potential for longwall shield dust control. PMID:29563765

  5. Automated analysis of images acquired with electronic portal imaging device during delivery of quality assurance plans for inversely optimized arc therapy

    DEFF Research Database (Denmark)

    Fredh, Anna; Korreman, Stine; Rosenschöld, Per Munck af

    2010-01-01

    This work presents an automated method for comprehensively analyzing EPID images acquired for quality assurance of RapidArc treatment delivery. In-house-developed software has been used for the analysis and long-term results from measurements on three linacs are presented....

  6. Determination of Acreage Thermal Protection Foam Loss From Ice and Foam Impacts

    Science.gov (United States)

    Carney, Kelly S.; Lawrence, Charles

    2015-01-01

    A parametric study was conducted to establish Thermal Protection System (TPS) loss from foam and ice impact conditions similar to what might occur on the Space Launch System. This study was based upon the large amount of testing and analysis that was conducted with both ice and foam debris impacts on TPS acreage foam for the Space Shuttle Project External Tank. Test verified material models and modeling techniques that resulted from Space Shuttle related testing were utilized for this parametric study. Parameters varied include projectile mass, impact velocity and impact angle (5 degree and 10 degree impacts). The amount of TPS acreage foam loss as a result of the various impact conditions is presented.

  7. Structural Continuum Modeling of Space Shuttle External Tank Foam Insulation

    Science.gov (United States)

    Steeve, Brian; Ayala, Sam; Purlee, T. Eric; Shaw, Phillip

    2006-01-01

    This document is a viewgraph presentation reporting on work in modeling the foam insulation of the Space Shuttle External Tank. An analytical understanding of foam mechanics is required to design against structural failure. The Space Shuttle External Tank is covered primarily with closed cell foam to: Prevent ice, Protect structure from ascent aerodynamic and engine plume heating, and Delay break-up during re-entry. It is important that the foam does not shed unacceptable debris during ascent environment. Therefore a modeling of the foam insulation was undertaken.

  8. The Improvement of Foam Concrete Geoecoprotective Properties in Transport Construction

    Science.gov (United States)

    Svatovskaya, Larisa; Kabanov, Alexander; Sychov, Maxim

    2017-10-01

    The article analyses 2 kinds of properties of silica sol foam concrete: technical and geoecoprotective ones. Foam concrete stabilized with silica sol foam has lower heat conductivity resulting in fuel saving. Foam concrete obtained according to sol absorption technology has lower water absorption and is good enough for blocking to prevent the environment pollution. Pollution blocking can be achieved by two methods. The first method is saturation of an article affected by oil products with silica sol. The second method is to create a special preventive protection using silica sol screen. The article shows geoecoprotective properties of protein foam soil systems.

  9. Application of polymeric foams for separation, storage and absorption of hydrogen

    Czech Academy of Sciences Publication Activity Database

    Pientka, Zbyněk; Nemestóthy, N.; Bélafi-Bakó, K.

    2009-01-01

    Roč. 241, 1-3 (2009), s. 106-110 ISSN 0011-9164. [Membrane Science and Technology Conference of Visegrad Countries PERMEA 2007 /3./. Siofok, 02.09.2007-06.09.2007] R&D Projects: GA ČR GA203/06/1207 Institutional research plan: CEZ:AV0Z40500505 Keywords : gas separation * hydrogen * polymeric foam Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.034, year: 2009

  10. Extra natural gas by foam injection; Extra aardgas door foam-injectie

    Energy Technology Data Exchange (ETDEWEB)

    De Boer, B.

    2008-07-01

    The Dutch Petroleum Company (NAM) has further developed an originally American technology for expanding the economic lifespan of gas fields. Injection of environment-friendly foam enables further extraction of natural gas from nearly depleted gas fields. [mk]. [Dutch] De Nederlandse Aardolie Maatschappij (NAM) heeft een van origine Amerikaanse techniek om de economische levensduur van gasvelden te verlengen verder ontwikkeld. Het injecteren van een milieuvriendelijke zeep (foam) maakt het mogelijk om langer aardgas te produceren uit bijna lege gasvelden.

  11. Advanced slab polyurethane foam with feather touch; Soft feather urethane foam no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Y; Ono, H [Toyota Motor Corp., Aichi (Japan); Mori, A; Yamaguchi, N; Nakamura, T [Bridgestone Corp., Tokyo (Japan)

    1997-10-01

    Automotive seat plays an important part, which are not only retention of sitting position, but also comfort and high-class feeling. Wadding, which is a part of the seat, is a key component for the sitting comfortableness. This paper is concerned with advanced slab polyurethane foam with feather touch feeling. The compounding of formation, foaming process and reliability of mass production is studied. 2 refs., 10 figs., 3 tabs.

  12. Experimental Study of Hysteresis behavior of Foam Generation in Porous Media

    OpenAIRE

    Kahrobaei, S.; Vincent-Bonnieu, S.; Farajzadeh, R.

    2017-01-01

    Foam can be used for gas mobility control in different subsurface applications. The success of foam-injection process depends on foam-generation and propagation rate inside the porous medium. In some cases, foam properties depend on the history of the flow or concentration of the surfactant, i.e., the hysteresis effect. Foam may show hysteresis behavior by exhibiting multiple states at the same injection conditions, where coarse-textured foam is converted into strong foam with fine texture at...

  13. Foam flow in a model porous medium: I. The effect of foam coarsening.

    Science.gov (United States)

    Jones, S A; Getrouw, N; Vincent-Bonnieu, S

    2018-05-09

    Foam structure evolves with time due to gas diffusion between bubbles (coarsening). In a bulk foam, coarsening behaviour is well defined, but there is less understanding of coarsening in confined geometries such as porous media. Previous predictions suggest that coarsening will cause foam lamellae to move to low energy configurations in the pore throats, resulting in greater capillary resistance when restarting flow. Foam coarsening experiments were conducted in both a model-porous-media micromodel and in a sandstone core. In both cases, foam was generated by coinjecting surfactant solution and nitrogen. Once steady state flow had been achieved, the injection was stopped and the system sealed off. In the micromodel, the foam coarsening was recorded using time-lapse photography. In the core flood, the additional driving pressure required to reinitiate flow after coarsening was measured. In the micromodel the bubbles coarsened rapidly to the pore size. At the completion of coarsening the lamellae were located in minimum energy configurations in the pore throats. The wall effect meant that the coarsening did not conform to the unconstricted growth laws. The coreflood tests also showed coarsening to be a rapid process. The additional driving pressure to restart flow reached a maximum after just 2 minutes.

  14. Processing, Characterization, and Modeling of Polymer/Clay Nanocomposite Foams

    Science.gov (United States)

    Jo, Choonghee; Naguib, Hani E.

    2007-04-01

    The effects of the material parameters and processing conditions on the foam morphologies, and mechanical properties of polymer/clay nanocomposite foams were studied. Microcellular closed-cell nanocomposite foams were manufactured with poly(methylmethacrylate) (PMMA) and high density polyethylene (HDPE), where the nanoclay loadings of 0.5, 1.0, and 2.0 wt% were used. The effect of clay contents and foaming conditions on the volume expansion ratio, cell size, elastic modulus, tensile strength, and elongation at break were investigated and compared between amorphous and semicrystalline polymers. An elastic modulus model for tensile behavior of foams was proposed by using the micromechanics theory. The model was expressed in terms of microstructural properties of polymer and physical properties of the foams. The tensile experimental data of the foams were compared with those predicted by the theoretical model.

  15. The viscosity window of the silicate glass foam production

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    2017-01-01

    which can offer a practical starting point for the optimisation procedure. The melt viscosity might be the most important parameter for controlling the foaming process and the glass foam density. In this work, we attempt to define a viscosity range in which foaming of different glasses results...... in a maximum of foam expansion. The expansion maximum is obtained for different glasses (labware, E-glass, CRT panel, soda-lime-silica) by foaming with CaCO3 at isokom temperature and from literature data. In general, the viscosity window was found to be within 104–106 Pa s when foaming with MnO2 or metal...... carbonates (CaCO3, Na2CO3, MgCO3, SrCO3, dolomite) whereas SiC requires higher temperatures and correspondingly lower viscosities (103.3–104.0 Pa s). These findings can help assessing the implementation of new resources in the glass foam production....

  16. Formulation, Preparation, and Characterization of Polyurethane Foams

    Science.gov (United States)

    Pinto, Moises L.

    2010-01-01

    Preparation of laboratory-scale polyurethane foams is described with formulations that are easy to implement in experiments for undergraduate students. Particular attention is given to formulation aspects that are based on the main chemical reactions occurring in polyurethane production. This allows students to develop alternative formulations to…

  17. Rigid polyurethane and kenaf core composite foams

    Science.gov (United States)

    Rigid polyurethane foams are valuable in many construction applications. Kenaf is a bast fiber plant where the surface stem skin provides bast fibers whose strength-to-weight ratio competes with glass fiber. The higher volume product of the kenaf core is an under-investigated area in composite appli...

  18. Indentation of aluminium foam at low velocity

    Directory of Open Access Journals (Sweden)

    Shi Xiaopeng

    2015-01-01

    Full Text Available The indentation behaviour of aluminium foams at low velocity (10 m/s ∼ 30 m/s was investigated both in experiments and numerical simulation in this paper. A flat-ended indenter was used and the force-displacement history was recorded. The Split Hopkinson Pressure bar was used to obtain the indentation velocity and forces in the dynamic experiments. Because of the low strength of the aluminium foam, PMMA bar was used, and the experimental data were corrected using Bacon's method. The energy absorption characteristics varying with impact velocity were then obtained. It was found that the energy absorption ability of aluminium foam gradually increases in the quasi-static regime and shows a significant increase at ∼10 m/s velocity. Numerical simulation was also conducted to investigate this process. A 3D Voronoi model was used and models with different relative densities were investigated as well as those with different failure strain. The indentation energy increases with both the relative density and failure strain. The analysis of the FE model implies that the significant change in energy absorption ability of aluminium foam in indentation at ∼10 m/s velocity may be caused by plastic wave effect.

  19. Premixed combustion on ceramic foam burners

    NARCIS (Netherlands)

    Bouma, P.H.; Goey, de L.P.H.

    1999-01-01

    Combustion of a lean premixed methane–air mixture stabilized on a ceramic foam burner has been studied. The stabilization of the flame in the radiant mode has been simulated using a one-dimensional numerical model for a burner stabilized flat-flame, taking into account the heat transfer between the

  20. Nano-Aramid Fiber Reinforced Polyurethane Foam

    Science.gov (United States)

    Semmes, Edmund B.; Frances, Arnold

    2008-01-01

    Closed cell polyurethane and, particularly, polyisocyanurate foams are a large family of flexible and rigid products the result of a reactive two part process wherein a urethane based polyol is combined with a foaming or "blowing" agent to create a cellular solid at room temperature. The ratio of reactive components, the constituency of the base materials, temperature, humidity, molding, pouring, spraying and many other processing techniques vary greatly. However, there is no known process for incorporating reinforcing fibers small enough to be integrally dispersed within the cell walls resulting in superior final products. The key differentiating aspect from the current state of art resides in the many processing technologies to be fully developed from the novel concept of milled nano pulp aramid fibers and their enabling entanglement capability fully enclosed within the cell walls of these closed cell urethane foams. The authors present the results of research and development of reinforced foam processing, equipment development, strength characteristics and the evolution of its many applications.

  1. Foam-forming properties of Ilex paraguariensis (mate saponin: foamability and foam lifetime analysis by Weibull equation

    Directory of Open Access Journals (Sweden)

    Janine Treter

    2010-01-01

    Full Text Available Saponins are natural soaplike foam-forming compounds widely used in foods, cosmetic and pharmaceutical preparations. In this work foamability and foam lifetime of foams obtained from Ilex paraguariensis unripe fruits were analyzed. Polysorbate 80 and sodium dodecyl sulfate were used as reference surfactants. Aiming a better data understanding a linearized 4-parameters Weibull function was proposed. The mate hydroethanolic extract (ME and a mate saponin enriched fraction (MSF afforded foamability and foam lifetime comparable to the synthetic surfactants. The linearization of the Weibull equation allowed the statistical comparison of foam decay curves, improving former mathematical approaches.

  2. INFLUENCE OF THE CEMENT TYPE ON THE CHARACTERISTICS OF THE MINERAL FOAM APPLICABLE IN FOAMED CERAMIC TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Korolev Evgeniy Valer'evich

    2012-10-01

    Full Text Available The subject of the research is the influence of the type of Portland cement, as well as the nature and concentration of additives that represent electrolytes and polymers, onto the foam stability. The project is implemented within the framework of the research of foamed ceramic. Detailed explanation of the influence pattern is provided. The research performed by the authors has generated the following findings. Besides the rheological properties of the solution, chemical interaction between the mix components must be taken into account in the course of development of the best foamed ceramic mix composition, as chemical processes produce a substantial influence onto the foam stability. Polymer additives based on liquid carbamyde-formaldehyde and polyacrylamide substantially improve the quality of the foam mineralized by the particles of the cement binder. They also assure the foam stability rate sufficient for the formation of a high-quality foamed material.

  3. After Delivery

    Science.gov (United States)

    ... Rights Employment Discrimination Health Care Professionals Law Enforcement Driver's License For Lawyers Food & Fitness Home Food MyFoodAdvisor ... A Listen En Español After Delivery After your baby arrives, your body begins to recover from the ...

  4. Foam dressings for treating pressure ulcers.

    Science.gov (United States)

    Walker, Rachel M; Gillespie, Brigid M; Thalib, Lukman; Higgins, Niall S; Whitty, Jennifer A

    2017-10-12

    Pressure ulcers, also known as pressure injuries and bed sores, are localised areas of injury to the skin or underlying tissues, or both. Dressings made from a variety of materials, including foam, are used to treat pressure ulcers. An evidence-based overview of dressings for pressure ulcers is needed to enable informed decision-making on dressing use. This review is part of a suite of Cochrane Reviews investigating the use of dressings in the treatment of pressure ulcers. Each review will focus on a particular dressing type. To assess the clinical and cost effectiveness of foam wound dressings for healing pressure ulcers in people with an existing pressure ulcer in any care setting. In February 2017 we searched: the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase; EBSCO CINAHL Plus and the NHS Economic Evaluation Database (NHS EED). We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting. Published or unpublished randomised controlled trials (RCTs) and cluster-RCTs, that compared the clinical and cost effectiveness of foam wound dressings for healing pressure ulcers (Category/Stage II or above). Two review authors independently performed study selection, risk of bias and data extraction. A third reviewer resolved discrepancies between the review authors. We included nine trials with a total of 483 participants, all of whom were adults (59 years or older) with an existing pressure ulcer Category/Stage II or above. All trials had two arms, which compared foam dressings with other dressings for treating pressure ulcers.The certainty of evidence ranged from low to very low due

  5. Forward planning

    International Nuclear Information System (INIS)

    Fontenla, D.P.

    2008-01-01

    By definition, forward planning is a process where input consists of conditions on beam configurations and parameters and output consists of dose distributions on target and critical structures, in contrast to inverse planning, where the opposite is true. For forward planning IMRT, criteria are as follows: (i) Plans created as an extension of standard 3D conformational planning; (ii) No significant increase in the complexity of the treatment planning or treatment delivery process; (3) Treatment verification using standard QA procedures; and process consists of the following steps: (i) Create a standard 3D conformational treatment plan; (ii) Copy one of the existing beams; (iii) Create control points: design new beam segments, blocking high dose areas; (iv) Repeat for all beams; (v) Re-compute dose; and (vi) Adjust control points weights to achieve desired dose distribution. A detailed exposition, with many clinical examples, is given for the breast, lung, and brain (P.A.)

  6. Delivery 7 Report on the impact of conflicts/synergies and policy proposals for implementing the EU Action Plan in member states

    DEFF Research Database (Denmark)

    Beck, Anne-Marie Tyroll; Michelsen, Johannes

    This report on “Implementing the European Organic Action Plan in EU member states - stakeholders’ perceptions of implementation problems and coping strategies” recapitulates the results of a series of national workshops undertaken in winter/spring 2007. It brings together very different views...... and perceptions on organic action plans and possible evaluation methodologies and can be seen as ORGAP’s stakeholder oriented or public oriented step....

  7. Ceramic Foams from Pre-Ceramic Polymer Routes for Reusable Acreage Thermal Protection System Applications

    Science.gov (United States)

    Stackpoole, Mairead; Chien, Jennifer; Schaeffler, Michelle

    2004-01-01

    Contents include the following: Motivation. Current light weight insulation. Advantages of preceramic-polymer-derived ceramic foams. Rigid insulation materials. Tailor foam microstructures. Experimental approach. Results: sacrificial materials, sacrificial fillers. Comparison of foam microstructures. Density of ceramic foams. Phase evolution and properties: oxidation behavior. mechanical properties, aerothermal performance. Impact damage of microcellular foams. Conclusions.

  8. Structural Foams of Biobased Isosorbide-Containing Copolycarbonate

    Directory of Open Access Journals (Sweden)

    Stefan Zepnik

    2017-01-01

    Full Text Available Isosorbide-containing copolycarbonate (Bio-PC is a partly biobased alternative to conventional bisphenol A (BPA based polycarbonate (PC. Conventional PC is widely used in polymer processing technologies including thermoplastic foaming such as foam injection molding. At present, no detailed data is available concerning the foam injection molding behavior and foam properties of Bio-PC. This contribution provides first results on injection-molded foams based on isosorbide-containing PC. The structural foams were produced by using an endothermic chemical blowing agent (CBA masterbatch and the low pressure foam injection molding method. The influence of weight reduction and blowing agent concentration on general foam properties such as density, morphology, and mechanical properties was studied. The test specimens consist of a foam core in the center and compact symmetrical shell layers on the sides. The thickness of the foam core increases with increasing weight reduction irrespective of the CBA concentration. The specific (mechanical bending properties are significantly improved and the specific tensile properties can almost be maintained while reducing the density of the injection-molded parts.

  9. Nanoparticle-stabilized CO₂ foam for CO₂ EOR application

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ning [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); Lee, Robert [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); Yu, Jianjia [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); Li, Liangxiong [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); Bustamante, Elizabeth [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); Khalil, Munawar [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); Mo, Di [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); Jia, Bao [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); Wang, Sai [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); San, Jingshan [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States); An, Cheng [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States)

    2015-01-31

    The purpose of this project was to develop nanoparticle-stabilized CO₂ foam for CO₂ -EOR application, in which nanoparticles instead of surfactants are used for stabilizing CO₂ foam to improve the CO₂ sweep efficiency and increase oil recovery. The studies included: (1) investigation of CO₂ foam generation nanoparticles, such as silica nanoparticles, and the effects of particle concentration and surface properties, CO₂/brine ratio, brine salinity, pressure, and temperature on foam generation and foam stability; (2) coreflooding tests to understand the nanoparticle-stabilized CO₂ foam for waterflooded residual oil recovery, which include: oil-free coreflooding experiments with nanoparticle-stabilized CO₂ foam to understand the transportation of nanoparticles through the core; measurements of foam stability and CO₂ sweep efficiency under reservoir conditions to investigate temperature and pressure effects on the foam performance and oil recovery as well as the sweep efficiency in different core samples with different rock properties; and (3) long-term coreflooding experiments with the nanoparticle- stabilized CO₂ foam for residual oil recovery. Finally, the technical and economical feasibility of this technology was evaluated.

  10. Rigid Polyurethane Foam Thermal Insulation Protected with Mineral Intumescent Mat

    Directory of Open Access Journals (Sweden)

    Kirpluks Mikelis

    2014-12-01

    Full Text Available One of the biggest disadvantages of rigid polyurethane (PU foams is its low thermal resistance, high flammability and high smoke production. Greatest advantage of this thermal insulation material is its low thermal conductivity (λ, which at 18-28 mW/(m•K is superior to other materials. To lower the flammability of PU foams, different flame retardants (FR are used. Usually, industrially viable are halogenated liquid FRs but recent trends in EU regulations show that they are not desirable any more. Main concern is toxicity of smoke and health hazard form volatiles in PU foam materials. Development of intumescent passive fire protection for foam materials would answer problems with flammability without using halogenated FRs. It is possible to add expandable graphite (EG into PU foam structure but this increases the thermal conductivity greatly. Thus, the main advantage of PU foam is lost. To decrease the flammability of PU foams, three different contents 3%; 9% and 15% of EG were added to PU foam formulation. Sample with 15% of EG increased λ of PU foam from 24.0 to 30.0 mW/(m•K. This paper describes the study where PU foam developed from renewable resources is protected with thermally expandable intumescent mat from Technical Fibre Products Ltd. (TFP as an alternative to EG added into PU material. TFP produces range of mineral fibre mats with EG that produce passive fire barrier. Two type mats were used to develop sandwich-type PU foams. Also, synergy effect of non-halogenated FR, dimethyl propyl phosphate and EG was studied. Flammability of developed materials was assessed using Cone Calorimeter equipment. Density, thermal conductivity, compression strength and modulus of elasticity were tested for developed PU foams. PU foam morphology was assessed from scanning electron microscopy images.

  11. Using egg albumin foam to extinguish fires

    Directory of Open Access Journals (Sweden)

    Hytham A. Alsaati

    2003-12-01

    Full Text Available Oil, coal and chemical fires are often difficult to put out using water. In certain hydrocarbon fires, protein foam can extinguish fires better than water by keeping air (oxygen away from the flames and by ''blowing'' the flame away from its fuel source. Egg albumin is a relatively inexpensive protein and is representative of foaming proteins, which are candidates for use as fire suppression agents. This paper begins to deal with the effect of the foam bulk pH, foam protein concentration and generating air flow rate into the foam on the fire extinguishing time in laboratory experiments. A Bunsen burner was used to generate a small, controlled laboratory fire within a plastic container, which represented a point source in a partially open room in the experiments. The Bunsen burner represents a gaseous hydrocarbon fire, which can be difficult to extinguish. Both a low pH foam and one made with a high air flow rate favor a reduction in time required to put out the Bunsen burner flame.Chamas produzidas por óleo, carvão e produtos químicos (incêndios provocados são difíceis de ser extinguidos com água. Algumas chamas de hidrocarbonetos podem ser extinguidas por espumas protéicas melhor do que a manutenção de ar (oxigênio fora do alcance das chamas ou pelo sopramento da chama para longe da sua fonte. Albumina de ovo é uma proteína relativamente barata e é representativa dentre as proteínas usadas como espuma para a (supressão extinção de agentes causadores de incêndio. Este artigo trata do estudo do efeito do pH e concentração da espuma protéica, além da geração de ar no interior da espuma, sobre o tempo de extinção de incêndio em experimentos laboratoriais. Nos experimentos um bico de Bunsen foi usado para gerar uma pequena chama, controlada em um container de plástico, representando uma fonte pontual em um ambiente parcialmente aberto. A chama do bico de Bunsen representa uma chama gasosa de hidrocarbonetos, que são dif

  12. microRNA-150 inhibits the formation of macrophage foam cells through targeting adiponectin receptor 2

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing [Department of Geratory, Linzi District People’s Hospital of Zibo City, Zibo, Shandong (China); Zhang, Suhua, E-mail: drsuhuangzhang@qq.com [Department of HealthCare, Qilu Hospital of Shandong University (Qingdao), Qingdao City, Qingdao (China)

    2016-08-05

    Transformation of macrophages into foam cells plays a critical role in the pathogenesis of atherosclerosis. The aim of this study was to determine the expression and biological roles of microRNA (miR)-150 in the formation of macrophage foam cells and to identify its functional target(s). Exposure to 50 μg/ml oxidized low-density lipoprotein (oxLDL) led to a significant upregulation of miR-150 in THP-1 macrophages. Overexpression of miR-150 inhibited oxLDL-induced lipid accumulation in THP-1 macrophages, while knockdown of miR-150 enhanced lipid accumulation. apoA-I- and HDL-mediated cholesterol efflux was increased by 66% and 43%, respectively, in miR-150-overexpressing macrophages relative to control cells. In contrast, downregulation of miR-150 significantly reduced cholesterol efflux from oxLDL-laden macrophages. Bioinformatic analysis and luciferase reporter assay revealed adiponectin receptor 2 (AdipoR2) as a direct target of miR-150. Small interfering RNA-mediated downregulation of AdipoR2 phenocopied the effects of miR-150 overexpression, reducing lipid accumulation and facilitating cholesterol efflux in oxLDL-treated THP-1 macrophages. Knockdown of AdipoR2 induced the expression of proliferator-activated receptor gamma (PPARγ), liver X receptor alpha (LXRα), ABCA1, and ABCG1. Moreover, pharmacological inhibition of PPARγ or LXRα impaired AdipoR2 silencing-induced upregulation of ABCA1 and ABCG1. Taken together, our results indicate that miR-150 can attenuate oxLDL-induced lipid accumulation in macrophages via promotion of cholesterol efflux. The suppressive effects of miR-150 on macrophage foam cell formation are mediated through targeting of AdipoR2. Delivery of miR-150 may represent a potential approach to prevent macrophage foam cell formation in atherosclerosis. -- Highlights: •miR-150 inhibits macrophage foam cell formation. •miR-150 accelerates cholesterol efflux from oxLDL-laden macrophages. •miR-150 suppresses macrophage foam cell

  13. SU-F-T-384: Step and Shoot IMRT, VMAT and Autoplan VMAT Nasopharnyx Plan Robustness to Linear Accelerator Delivery Errors

    Energy Technology Data Exchange (ETDEWEB)

    Pogson, EM [Institute of Medical Physics, The University of Sydney, Sydney, New South Wales (Australia); Liverpool and Macarthur Cancer Therapy Centres, Liverpool, NSW (United Kingdom); Ingham Institute for Applied Medical Research, Sydney, NSW (Australia); Hansen, C [Laboratory of Radiation Physics, Odense University Hospital, Odense (Denmark); Institute of Clinical Research, University of Southern Denmark, Odense (Denmark); Blake, S; Thwaites, D [Institute of Medical Physics, The University of Sydney, Sydney, New South Wales (Australia); Arumugam, S [Liverpool and Macarthur Cancer Therapy Centres, Liverpool, NSW (United Kingdom); Holloway, L [Institute of Medical Physics, The University of Sydney, Sydney, New South Wales (Australia); Liverpool and Macarthur Cancer Therapy Centres, Liverpool, NSW (United Kingdom); Laboratory of Radiation Physics, Odense University Hospital, Odense (Denmark); South Western Sydney Clinical School, University of New South Wales, Sydney, NSW (Australia); University of Wollongong, Wollongong, NSW (Australia)

    2016-06-15

    Purpose: To identify the robustness of different treatment techniques in respect to simulated linac errors on the dose distribution to the target volume and organs at risk for step and shoot IMRT (ssIMRT), VMAT and Autoplan generated VMAT nasopharynx plans. Methods: A nasopharynx patient dataset was retrospectively replanned with three different techniques: 7 beam ssIMRT, one arc manual generated VMAT and one arc automatically generated VMAT. Treatment simulated uncertainties: gantry, collimator, MLC field size and MLC shifts, were introduced into these plans at increments of 5,2,1,−1,−2 and −5 (degrees or mm) and recalculated in Pinnacle. The mean and maximum doses were calculated for the high dose PTV, parotids, brainstem, and spinal cord and then compared to the original baseline plan. Results: Simulated gantry angle errors have <1% effect on the PTV, ssIMRT is most sensitive. The small collimator errors (±1 and ±2 degrees) impacted the mean PTV dose by <2% for all techniques, however for the ±5 degree errors mean target varied by up to 7% for the Autoplan VMAT and 10% for the max dose to the spinal cord and brain stem, seen in all techniques. The simulated MLC shifts introduced the largest errors for the Autoplan VMAT, with the larger MLC modulation presumably being the cause. The most critical error observed, was the MLC field size error, where even small errors of 1 mm, caused significant changes to both the PTV and the OAR. The ssIMRT is the least sensitive and the Autoplan the most sensitive, with target errors of up to 20% over and under dosages observed. Conclusion: For a nasopharynx patient the plan robustness observed is highest for the ssIMRT plan and lowest for the Autoplan generated VMAT plan. This could be caused by the more complex MLC modulation seen for the VMAT plans. This project is supported by a grant from NSW Cancer Council.

  14. SU-F-T-384: Step and Shoot IMRT, VMAT and Autoplan VMAT Nasopharnyx Plan Robustness to Linear Accelerator Delivery Errors

    International Nuclear Information System (INIS)

    Pogson, EM; Hansen, C; Blake, S; Thwaites, D; Arumugam, S; Holloway, L

    2016-01-01

    Purpose: To identify the robustness of different treatment techniques in respect to simulated linac errors on the dose distribution to the target volume and organs at risk for step and shoot IMRT (ssIMRT), VMAT and Autoplan generated VMAT nasopharynx plans. Methods: A nasopharynx patient dataset was retrospectively replanned with three different techniques: 7 beam ssIMRT, one arc manual generated VMAT and one arc automatically generated VMAT. Treatment simulated uncertainties: gantry, collimator, MLC field size and MLC shifts, were introduced into these plans at increments of 5,2,1,−1,−2 and −5 (degrees or mm) and recalculated in Pinnacle. The mean and maximum doses were calculated for the high dose PTV, parotids, brainstem, and spinal cord and then compared to the original baseline plan. Results: Simulated gantry angle errors have <1% effect on the PTV, ssIMRT is most sensitive. The small collimator errors (±1 and ±2 degrees) impacted the mean PTV dose by <2% for all techniques, however for the ±5 degree errors mean target varied by up to 7% for the Autoplan VMAT and 10% for the max dose to the spinal cord and brain stem, seen in all techniques. The simulated MLC shifts introduced the largest errors for the Autoplan VMAT, with the larger MLC modulation presumably being the cause. The most critical error observed, was the MLC field size error, where even small errors of 1 mm, caused significant changes to both the PTV and the OAR. The ssIMRT is the least sensitive and the Autoplan the most sensitive, with target errors of up to 20% over and under dosages observed. Conclusion: For a nasopharynx patient the plan robustness observed is highest for the ssIMRT plan and lowest for the Autoplan generated VMAT plan. This could be caused by the more complex MLC modulation seen for the VMAT plans. This project is supported by a grant from NSW Cancer Council.

  15. Family Planning: Bosnian, Russian, Spanish, Nuer.

    Science.gov (United States)

    Anoka County Community Health and Environmental Services, Coon Rapids, MN.

    This guide provides information in English, Bosnian, Russian, Spanish, and Nuer on family planning. Topics covered include a variety of birth control methods: abstinence, condoms, contraceptive foam, birth control pills, the Depo-Provera shot, the Norplant implant, diaphragms, intrauterine devices, natural family planning, sterilization, and the…

  16. Porosity and cell size control in alumina foam preparation by thermo-foaming of powder dispersions in molten sucrose

    Directory of Open Access Journals (Sweden)

    Sujith Vijayan

    2016-09-01

    Full Text Available The foaming characteristics of alumina powder dispersions in molten sucrose have been studied as a function of alumina powder to sucrose weight ratio (WA/S and foaming temperature. The increase in foaming temperature significantly decreases the foaming and foam setting time and increases the foam volume due to an increase in the rate of OH condensation as well as a decrease in the viscosity of the dispersion. Nevertheless, the foam collapses beyond a critical foaming temperature, which depends on the WA/S. The sintering shrinkage depends mainly on the WA/S and marginally on the foaming temperature. The porosity (83.4–94.6 vol.% and cell size (0.55–1.6 mm increase with an increase in foaming temperature (120–170 °C and a decrease in WA/S (0.8–1.6. The drastic decrease in compressive strength and modulus beyond a WA/S of 1.2 is due to the pores generated on the cell walls and struts as a result of particle agglomeration. Gibson and Ashby plots show large deviation with respect to the model constants ‘C’ and ‘n’, especially at higher alumina powder to sucrose weight ratios.

  17. Morphological comparison of PVA scaffolds obtained by gas foaming and microfluidic foaming techniques.

    Science.gov (United States)

    Colosi, Cristina; Costantini, Marco; Barbetta, Andrea; Pecci, Raffaella; Bedini, Rossella; Dentini, Mariella

    2013-01-08

    In this article, we have exploited a microfluidic foaming technique for the generation of highly monodisperse gas-in-liquid bubbles as a templating system for scaffolds characterized by an ordered and homogeneous porous texture. An aqueous poly(vinyl alcohol) (PVA) solution (containing a surfactant) and a gas (argon) are injected simultaneously at constant flow rates in a flow-focusing device (FFD), in which the gas thread breaks up to form monodisperse bubbles. Immediately after its formation, the foam is collected and frozen in liquid nitrogen, freeze-dried, and cross-linked with glutaraldehyde. In order to highlight the superior morphological quality of the obtained porous material, a comparison between this scaffold and another one, also constituted of PVA but obtained with a traditional gas foaming technique, was carried out. Such a comparison has been conducted by analyzing electron microscopy and X-ray microtomographic images of the two samples. It turned out that the microfluidic produced scaffold was characterized by much more uniform porous texture than the gas-foaming one as witnessed by narrower pore size, interconnection, and wall thickness distributions. On the other side, scarce pore interconnectivity, relatively low pore volume, and limited production rate represent, by now, the principal disadvantages of microfluidic foaming as scaffold fabrication method, emphasizing the kind of improvement that this technique needs to undergo.

  18. Investigation of Chemical-Foam Design as a Novel Approach toward Immiscible Foam Flooding for Enhanced Oil Recovery.

    Science.gov (United States)

    Hosseini-Nasab, S M; Zitha, P L J

    2017-10-19

    Strong foam can be generated in porous media containing oil, resulting in incremental oil recovery; however, oil recovery factor is restricted. A large fraction of oil recovered by foam flooding forms an oil-in-water emulsion, so that costly methods may need to be used to separate the oil. Moreover, strong foam could create a large pressure gradient, which may cause fractures in the reservoir. This study presents a novel chemical-foam flooding process for enhanced oil recovery (EOR) from water-flooded reservoirs. The presented method involved the use of chemically designed foam to mobilize the remaining oil after water flooding and then to displace the mobilized oil to the production well. A blend of two anionic surfactant formulations was formulated for this method: (a) IOS, for achieving ultralow interfacial tension (IFT), and (b) AOS, for generating a strong foam. Experiments were performed using Bentheimer sandstone cores, where X-ray CT images were taken during foam generation to find the stability of the advancing front of foam propagation and to map the gas saturation for both the transient and the steady-state flow regimes. Then the proposed chemical-foam strategy for incremental oil recovery was tested through the coinjection of immiscible nitrogen gas and surfactant solutions with three different formulation properties in terms of IFT reduction and foaming strength capability. The discovered optimal formulation contains a foaming agent surfactant, a low IFT surfactant, and a cosolvent, which has a high foam stability and a considerably low IFT (1.6 × 10 -2 mN/m). Coinjection resulted in higher oil recovery and much less MRF than the same process with only using a foaming agent. The oil displacement experiment revealed that coinjection of gas with a blend of surfactants, containing a cosolvent, can recover a significant amount of oil (33% OIIP) over water flooding with a larger amount of clean oil and less emulsion.

  19. Value Stream Mapping: Foam Collection and Processing.

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, Christian [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-07-01

    The effort to collect and process foam for the purpose of recycling performed by the Material Sustainability and Pollution Prevention (MSP2) team at Sandia National Laboratories is an incredible one, but in order to make it run more efficiently it needed some tweaking. This project started in June of 2015. We used the Value Stream Mapping process to allow us to look at the current state of the foam collection and processing operation. We then thought of all the possible ways the process could be improved. Soon after that we discussed which of the "dreams" were feasible. And finally, we assigned action items to members of the team so as to ensure that the improvements actually occur. These improvements will then, due to varying factors, continue to occur over the next couple years.

  20. Foam topology. Bending versus stretching dominated architectures

    International Nuclear Information System (INIS)

    Deshpande, V.; Ashby, M.; Fleck, N.

    2000-01-01

    Cellular solids can deform by either the bending or stretching of the cell walls. While most cellular solids are bending-dominated, those that are stretching-dominated are much more weight-efficient for structural applications. In this study we have investigated the topological criteria that dictate the deformation mechanism of a cellular solid by analysing the rigidity (or otherwise) of pin-jointed frameworks comprising inextensional struts. We show that the minimum node connectivity for a special class of lattice structured materials to be stretching-dominated is 6 for 2D foams and 12 for 3D foams. Similarly, sandwich plates comprising of truss cores faced with planar trusses require a minimum node connectivity of 9 to undergo stretching-dominated deformation for all loading states. (author)

  1. Measurement of Aqueous Foam Rheology by Acoustic Levitation

    Science.gov (United States)

    McDaniel, J. Gregory; Holt, R. Glynn; Rogers, Rich (Technical Monitor)

    2000-01-01

    An experimental technique is demonstrated for acoustically levitating aqueous foam drops and exciting their spheroidal modes. This allows fundamental studies of foam-drop dynamics that provide an alternative means of estimating the viscoelastic properties of the foam. One unique advantage of the technique is the lack of interactions between the foam and container surfaces, which must be accounted for in other techniques. Results are presented in which a foam drop with gas volume fraction phi = 0.77 is levitated at 30 kHz and excited into its first quadrupole resonance at 63 +/- 3 Hz. By modeling the drop as an elastic sphere, the shear modulus of the foam was estimated at 75 +/- 3 Pa.

  2. Tough graphene-polymer microcellular foams for electromagnetic interference shielding.

    Science.gov (United States)

    Zhang, Hao-Bin; Yan, Qing; Zheng, Wen-Ge; He, Zhixian; Yu, Zhong-Zhen

    2011-03-01

    Functional polymethylmethacrylate (PMMA)/graphene nanocomposite microcellular foams were prepared by blending of PMMA with graphene sheets followed by foaming with subcritical CO(2) as an environmentally benign foaming agent. The addition of graphene sheets endows the insulating PMMA foams with high electrical conductivity and improved electromagnetic interference (EMI) shielding efficiency with microwave absorption as the dominant EMI shielding mechanism. Interestingly, because of the presence of the numerous microcellular cells, the graphene-PMMA foam exhibits greatly improved ductility and tensile toughness compared to its bulk counterpart. This work provides a promising methodology to fabricate tough and lightweight graphene-PMMA nanocomposite microcellular foams with superior electrical and EMI shielding properties by simultaneously combining the functionality and reinforcement of the graphene sheets and the toughening effect of the microcellular cells.

  3. Experimental study on microstructure characters of foamed lightweight soil

    Science.gov (United States)

    Qiu, Youqiang; Li, Yongliang; Li, Meixia; Liu, Yaofu; Zhang, Liujun

    2018-01-01

    In order to verify the microstructure of foamed lightweight soil and its characters of compressive strength, four foamed lightweight soil samples with different water-soild ratio were selected and the microstructure characters of these samples were scanned by electron microscope. At the same time, the characters of compressive strength of foamed lightweight soil were analyzed from the microstructure. The study results show that the water-soild ratio has a prominent effect on the microstructure and compressive strength of foamed lightweight soil, with the decrease of water-solid ratio, the amount and the perforation of pores would be reduced significantly, thus eventually forming a denser and fuller interior structure. Besides, the denser microstructure and solider pore-pore wall is benefit to greatly increase mechanical intensity of foamed lightweight soil. In addition, there are very few acicular ettringite crystals in the interior of foamed lightweight soil, its number is also reduced with the decrease in water-soild ratio.

  4. Foamed emulsion drainage: flow and trapping of drops.

    Science.gov (United States)

    Schneider, Maxime; Zou, Ziqiang; Langevin, Dominique; Salonen, Anniina

    2017-06-07

    Foamed emulsions are ubiquitous in our daily life but the ageing of such systems is still poorly understood. In this study we investigate foam drainage and measure the evolution of the gas, liquid and oil volume fractions inside the foam. We evidence three regimes of ageing. During an initial period of fast drainage, both bubbles and drops are very mobile. As the foam stabilises drainage proceeds leading to a gradual decrease of the liquid fraction and slowing down of drainage. Clusters of oil drops are less sheared, their dynamic viscosity increases and drainage slows down even further, until the drops become blocked. At this point the oil fraction starts to increase in the continuous phase. The foam ageing leads to an increase of the capillary pressure until the oil acts as an antifoaming agent and the foam collapses.

  5. Experimental demonstration of laser imprint reduction using underdense foams

    International Nuclear Information System (INIS)

    Delorme, B.; Casner, A.; Olazabal-Loumé, M.; Nicolaï, Ph.; Breil, J.; Tikhonchuk, V. T.; Michel, D. T.; Seka, W.; Froula, D. H.; Goncharov, V.; Riazuelo, G.; Borisenko, N.; Orekhov, A.; Fujioka, S.; Sunahara, A.; Grech, M.

    2016-01-01

    Reducing the detrimental effect of the Rayleigh-Taylor (RT) instability on the target performance is a critical challenge. In this purpose, the use of targets coated with low density foams is a promising approach to reduce the laser imprint. This article presents results of ablative RT instability growth measurements, performed on the OMEGA laser facility in direct-drive for plastic foils coated with underdense foams. The laser beam smoothing is explained by the parametric instabilities developing in the foam and reducing the laser imprint on the plastic (CH) foil. The initial perturbation pre-imposed by the means of a specific phase plate was shown to be smoothed using different foam characteristics. Numerical simulations of the laser beam smoothing in the foam and of the RT growth are performed with a suite of paraxial electromagnetic and radiation hydrodynamic codes. They confirmed the foam smoothing effect in the experimental conditions.

  6. Release of CFC-11 from disposal of polyurethane foam waste

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Jensen, M.H.

    2001-01-01

    The halocarbon CFC-11 has extensively been used as a blowing agent for polyurethane (PUR) insulation foams in home appliances and for residential and industrial construction. Release of CFCs is an important factor in the depletion of the ozone layer. For CFC-11 the future atmospheric concentrations...... will mainly depend on the continued release from PUR foams. Little is known about rates and time frames of the CFC release from foams especially after treatment and disposal of foam containing waste products. The CFC release is mainly controlled by slow diffusion out through the PUR. From the literature...... and by reevaluation of an old reported experiment, diffusion coefficients in the range of 0.05-1.7.10(-14) m(2) s(-1) were found reflecting differences in foam properties and experimental designs. Laboratory experiments studying the distribution of CFC in the foam and the short-term releases after shredding showed...

  7. Investigation into stress wave propagation in metal foams

    Directory of Open Access Journals (Sweden)

    Li Lang

    2015-01-01

    Full Text Available The aim of this study is to investigate stress wave propagation in metal foams under high-speed impact loading. Three-dimensional Voronoi model is established to represent real closed-cell foam. Based on the one-dimensional stress wave theory and Voronoi model, a numerical model is developed to calculate the velocity of elastic wave and shock wave in metal foam. The effects of impact velocity and relative density of metal foam on the stress wave propagation in metal foams are explored respectively. The results show that both elastic wave and shock wave propagate faster in metal foams with larger relative density; with increasing the impact velocity, the shock wave propagation velocity increase, but the elastic wave propagation is not sensitive to the impact velocity.

  8. Data characterizing tensile behavior of cenosphere/HDPE syntactic foam.

    Science.gov (United States)

    Kumar, B R Bharath; Doddamani, Mrityunjay; Zeltmann, Steven E; Gupta, Nikhil; Ramakrishna, Seeram

    2016-03-01

    The data set presented is related to the tensile behavior of cenosphere reinforced high density polyethylene syntactic foam composites "Processing of cenosphere/HDPE syntactic foams using an industrial scale polymer injection molding machine" (Bharath et al., 2016) [1]. The focus of the work is on determining the feasibility of using an industrial scale polymer injection molding (PIM) machine for fabricating syntactic foams. The fabricated syntactic foams are investigated for microstructure and tensile properties. The data presented in this article is related to optimization of the PIM process for syntactic foam manufacture, equations and procedures to develop theoretical estimates for properties of cenospheres, and microstructure of syntactic foams before and after failure. Included dataset contains values obtained from the theoretical model.

  9. Experimental demonstration of laser imprint reduction using underdense foams

    Energy Technology Data Exchange (ETDEWEB)

    Delorme, B.; Casner, A. [CEA, DAM, DIF, F-91297 Arpajon (France); CELIA, University of Bordeaux-CNRS-CEA, F-33400 Talence (France); Olazabal-Loumé, M. [CEA, DAM, CESTA, 15 Avenue des Sablières, F-33114 Le Barp (France); CELIA, University of Bordeaux-CNRS-CEA, F-33400 Talence (France); Nicolaï, Ph.; Breil, J.; Tikhonchuk, V. T. [CELIA, University of Bordeaux-CNRS-CEA, F-33400 Talence (France); Michel, D. T.; Seka, W.; Froula, D. H.; Goncharov, V. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Riazuelo, G. [CEA, DAM, DIF, F-91297 Arpajon (France); Borisenko, N.; Orekhov, A. [P. N. Lebedev Physical Institute, RAS, 53 Leninskii Prospect, Moscow 119991 (Russian Federation); Fujioka, S.; Sunahara, A. [Institute of Laser Engineering, Osaka University, Suita, Osaka 565 (Japan); Grech, M. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France)

    2016-04-15

    Reducing the detrimental effect of the Rayleigh-Taylor (RT) instability on the target performance is a critical challenge. In this purpose, the use of targets coated with low density foams is a promising approach to reduce the laser imprint. This article presents results of ablative RT instability growth measurements, performed on the OMEGA laser facility in direct-drive for plastic foils coated with underdense foams. The laser beam smoothing is explained by the parametric instabilities developing in the foam and reducing the laser imprint on the plastic (CH) foil. The initial perturbation pre-imposed by the means of a specific phase plate was shown to be smoothed using different foam characteristics. Numerical simulations of the laser beam smoothing in the foam and of the RT growth are performed with a suite of paraxial electromagnetic and radiation hydrodynamic codes. They confirmed the foam smoothing effect in the experimental conditions.

  10. A comparison of mechanical properties of some foams and honeycombs

    Science.gov (United States)

    Bhat, Balakrishna T.; Wang, T. G.

    1990-01-01

    A comparative study is conducted of the mechanical properties of foam-core and honeycomb-core sandwich panels, using a normalizing procedure based on common properties of cellular solids and related properties of dense solids. Seven different honeycombs and closed-foam cells are discussed; of these, three are commercial Al alloy honeycombs, one is an Al-alloy foam, and two are polymeric foams. It is concluded that ideal, closed-cell foams may furnish compressive strengths which while isotropic can be fully comparable to the compressive strengths of honeycombs in the thickness direction. The shear strength of ideal closed-cell foams may be superior to the shear strength of honeycombs.

  11. Foam glass obtained through high-pressure sintering

    DEFF Research Database (Denmark)

    Østergaard, Martin Bonderup; Petersen, Rasmus Rosenlund; König, Jakob

    2018-01-01

    Foam glasses are usually prepared through a chemical approach, that is, by mixing glass powder with foaming agents, and heating the mixture to a temperature above the softening point (106.6 Pa s) of the glass. The foaming agents release gas, enabling expansion of the sintered glass. Here, we use...... a physical foaming approach to prepare foam glass. First, closed pores filled with inert gases (He, Ar, or N2) are physically introduced into a glass body by sintering cathode ray tube (CRT) panel glass powder at high gas pressure (5‐25 MPa) at 640°C and, then cooled to room temperature. The sintered bodies...... are subjected to a second heat treatment above the glass transition temperature at atmospheric pressure. This heat treatment causes expansion of the pores due to high internal gas pressure. We found that the foaming ability strongly depends on the gas pressure applied during sintering, and on the kinetic...

  12. Coarse graining flow of spin foam intertwiners

    Science.gov (United States)

    Dittrich, Bianca; Schnetter, Erik; Seth, Cameron J.; Steinhaus, Sebastian

    2016-12-01

    Simplicity constraints play a crucial role in the construction of spin foam models, yet their effective behavior on larger scales is scarcely explored. In this article we introduce intertwiner and spin net models for the quantum group SU (2 )k×SU (2 )k, which implement the simplicity constraints analogous to four-dimensional Euclidean spin foam models, namely the Barrett-Crane (BC) and the Engle-Pereira-Rovelli-Livine/Freidel-Krasnov (EPRL/FK) model. These models are numerically coarse grained via tensor network renormalization, allowing us to trace the flow of simplicity constraints to larger scales. In order to perform these simulations we have substantially adapted tensor network algorithms, which we discuss in detail as they can be of use in other contexts. The BC and the EPRL/FK model behave very differently under coarse graining: While the unique BC intertwiner model is a fixed point and therefore constitutes a two-dimensional topological phase, BC spin net models flow away from the initial simplicity constraints and converge to several different topological phases. Most of these phases correspond to decoupling spin foam vertices; however we find also a new phase in which this is not the case, and in which a nontrivial version of the simplicity constraints holds. The coarse graining flow of the BC spin net models indicates furthermore that the transitions between these phases are not of second order. The EPRL/FK model by contrast reveals a far more intricate and complex dynamics. We observe an immediate flow away from the original simplicity constraints; however, with the truncation employed here, the models generically do not converge to a fixed point. The results show that the imposition of simplicity constraints can indeed lead to interesting and also very complex dynamics. Thus we need to further develop coarse graining tools to efficiently study the large scale behavior of spin foam models, in particular for the EPRL/FK model.

  13. Depressurized pipes decontamination by using circulation foam

    International Nuclear Information System (INIS)

    Damerval, Frederique; Belz, Jacques; Renouf, Marjorie; Janneau, Patrice

    2012-09-01

    Decontamination of pipes remains a necessity in order to reduce the radiation level during maintenance or dismantling operations but it is not so easy to do it, especially in case of a long pipe network. To achieve this operation, the use of chemistry is one of the more relevant methods; moreover, the liquid waste production still remains an issue that it can be avoided by the use of decontamination foams. (authors)

  14. RANS Simulations using OpenFOAM Software

    Science.gov (United States)

    2016-01-01

    OpenFOAM offers considerable advantages for Computational Fluid Dynamics (CFD) simulations; it is open source, free of charge, and has the ability...physics, laser- plasma interactions, warhead design, air blast, detonation physics and computational fluid dynamics . Since moving into the Hydrodynamics...private industry as a consultant at the company Xdin. Michel has been working in research projects with computational fluid dynamics focusing on

  15. Using the community-based health planning and services program to promote skilled delivery in rural Ghana: socio-demographic factors that influence women utilization of skilled attendants at birth in northern Ghana.

    Science.gov (United States)

    Sakeah, Evelyn; Doctor, Henry V; McCloskey, Lois; Bernstein, Judith; Yeboah-Antwi, Kojo; Mills, Samuel

    2014-04-10

    The burden of maternal mortality in sub-Saharan Africa is enormous. In Ghana the maternal mortality ratio was 350 per 100,000 live births in 2010. Skilled birth attendance has been shown to reduce maternal deaths and disabilities, yet in 2010 only 68% of mothers in Ghana gave birth with skilled birth attendants. In 2005, the Ghana Health Service piloted an enhancement of its Community-Based Health Planning and Services (CHPS) program, training Community Health Officers (CHOs) as midwives, to address the gap in skilled attendance in rural Upper East Region (UER). The study determined the extent to which CHO-midwives skilled delivery program achieved its desired outcomes in UER among birthing women. We conducted a cross-sectional household survey with women who had ever given birth in the three years prior to the survey. We employed a two stage sampling techniques: In the first stage we proportionally selected enumeration areas, and the second stage involved random selection of households. In each household, where there is more than one woman with a child within the age limit, we interviewed the woman with the youngest child. We collected data on awareness of the program, use of the services and factors that are associated with skilled attendants at birth. A total of 407 households/women were interviewed. Eighty three percent of respondents knew that CHO-midwives provided delivery services in CHPS zones. Seventy nine percent of the deliveries were with skilled attendants; and over half of these skilled births (42% of total) were by CHO-midwives. Multivariate analyses showed that women of the Nankana ethnic group and those with uneducated husbands were less likely to access skilled attendants at birth in rural settings. The implementation of the CHO-midwife program in UER appeared to have contributed to expanded skilled delivery care access and utilization for rural women. However, women of the Nankana ethnic group and uneducated men must be targeted with health

  16. The Construction of Spin Foam Vertex Amplitudes

    Directory of Open Access Journals (Sweden)

    Eugenio Bianchi

    2013-01-01

    Full Text Available Spin foam vertex amplitudes are the key ingredient of spin foam models for quantum gravity. These fall into the realm of discretized path integral, and can be seen as generalized lattice gauge theories. They can be seen as an attempt at a 4-dimensional generalization of the Ponzano-Regge model for 3d quantum gravity. We motivate and review the construction of the vertex amplitudes of recent spin foam models, giving two different and complementary perspectives of this construction. The first proceeds by extracting geometric configurations from a topological theory of the BF type, and can be seen to be in the tradition of the work of Barrett, Crane, Freidel and Krasnov. The second keeps closer contact to the structure of Loop Quantum Gravity and tries to identify an appropriate set of constraints to define a Lorentz-invariant interaction of its quanta of space. This approach is in the tradition of the work of Smolin, Markopoulous, Engle, Pereira, Rovelli and Livine.

  17. Growth of carbon nanofilaments on coal foams

    Energy Technology Data Exchange (ETDEWEB)

    Montserrat Calvo; Ana Arenillas; Roberto Garcia; Sabino R. Moinelo [Instituto Nacional del Carbon (INCAR), Oviedo (Spain)

    2009-01-15

    Nanofilamentous carbon was grown on a carbon foam by catalytic chemical vapour deposition (CVD) using the decomposition of ethylene/hydrogen mixtures over Ni. The carbon foam was obtained from a coal by a two-stage thermal process, with the first stage taking place at a temperature within the plastic region of the precursor coal. The extent of porosity and the pore size of the foam were mainly influenced by the pressure reached in the reactor during the first stage. In the CVD process, 700{sup o}C was the optimum temperature for obtaining good yields of nanofilaments. A low ethylene/hydrogen ratio (1/4) in the reactive gas gave rise to almost only short and thin carbon nanostructures. A higher proportion of C{sub 2}H{sub 4} (4/1, C{sub 2}H{sub 4}/H{sub 2}) gave better yields of nanofilaments, with good proportions of higher-length and higher-diameter (up to around 0.5 {mu}m) structures. Among the carbon forms produced, transmission electron microscopy revealed the predominance of fishbone-type nanofibres, with some bamboo-like nanotubes being also observed. 41 refs., 7 figs., 3 tabs.

  18. Forming and bending of metal foams

    International Nuclear Information System (INIS)

    Nebosky, Paul; Tyszka, Daniel; Niebur, Glen; Schmid, Steven

    2004-01-01

    This study examines the formability of a porous tantalum foam, known as trabecular metal (TM). Used as a bone ingrowth surface on orthopedic implants, TM is desirable due to its combination of high strength, low relative density, and excellent osteoconductive properties. This research aims to develop bend and stretch forming as a cost-effective alternative to net machining and EDM for manufacturing thin parts made of TM. Experimentally, bending about a single axis using a wiping die was studied by observing cracking and measuring springback. It was found that die radius and clearance strongly affect the springback properties of TM, while punch speed, embossings, die radius and clearance all influence cracking. Depending on the various combinations of die radius and clearance, springback factor ranged from .70-.91. To examine the affect of the foam microstructure, bending also was examined numerically using a horizontal hexagonal mesh. As the hexagonal cells were elongated along the sheet length, elastic springback decreased. This can be explained by the earlier onset of plastic hinging occurring at the vertices of the cells. While the numerical results matched the experimental results for the case of zero clearance, differences at higher clearances arose due to an imprecise characterization of the post-yield properties of tantalum. By changing the material properties of the struts, the models can be modified for use with other open-cell metallic foams

  19. Mechanisms of foam cell formation in atherosclerosis.

    Science.gov (United States)

    Chistiakov, Dimitry A; Melnichenko, Alexandra A; Myasoedova, Veronika A; Grechko, Andrey V; Orekhov, Alexander N

    2017-11-01

    Low-density lipoprotein (LDL) and cholesterol homeostasis in the peripheral blood is maintained by specialized cells, such as macrophages. Macrophages express a variety of scavenger receptors (SR) that interact with lipoproteins, including SR-A1, CD36, and lectin-like oxLDL receptor-1 (LOX-1). These cells also have several cholesterol transporters, including ATP-binding cassette transporter ABCA1, ABCG1, and SR-BI, that are involved in reverse cholesterol transport. Lipids internalized by phagocytosis are transported to late endosomes/lysosomes, where lysosomal acid lipase (LAL) digests cholesteryl esters releasing free cholesterol. Free cholesterol in turn is processed by acetyl-CoA acetyltransferase (ACAT1), an enzyme that transforms cholesterol to cholesteryl esters. The endoplasmic reticulum serves as a depot for maintaining newly synthesized cholesteryl esters that can be processed by neutral cholesterol ester hydrolase (NCEH), which generates free cholesterol that can exit via cholesterol transporters. In atherosclerosis, pro-inflammatory stimuli upregulate expression of scavenger receptors, especially LOX-1, and downregulate expression of cholesterol transporters. ACAT1 is also increased, while NCEH expression is reduced. This results in deposition of free and esterified cholesterol in macrophages and generation of foam cells. Moreover, other cell types, such as endothelial (ECs) and vascular smooth muscle cells (VSMCs), can also become foam cells. In this review, we discuss known pathways of foam cell formation in atherosclerosis.

  20. Improvement of stability of polidocanol foam for nonsurgical permanent contraception.

    Science.gov (United States)

    Guo, Jian Xin; Lucchesi, Lisa; Gregory, Kenton W

    2015-08-01

    Polidocanol foam (PF), used clinically as a venous sclerosant, has recently been studied as a safe and inexpensive means for permanent contraception. Delivering the sclerosant to the fallopian tubes as a foam rather than a liquid increases the surface areas and thus enhances the desired epithelial disrupting activity of the agent. However, the foam is inherently unstable and degrades with time. Therefore, increasing foam stability and thus duration of the agent exposure time could increase epithelial effect while allowing reduction in agent concentration and potential toxicity. We studied methods to improve foam properties that might improve safety and efficacy of PF for intrauterine application. Several types of microporous filters adapted to a syringe-based foaming device were used to study the effect of pore structures on the formation of PF. The foam drainage time and bubble size were characterized. The addition of benzalkonium chloride (BZK) to polidocanol was also investigated for its effects on foam characteristics. A syringe-based foaming device adapted with an inline filter produced smaller bubble PF with a longer foam drainage time. PF generated with a circular pore filter lasts longer than with a noncircular pore filter. The addition of 0.01% of BZK also improved the stability of PF. The stability of PF is affected by the pore characteristics of the filter used for foam generation and enhanced by the presence of a small amount of BZK. The improved foam, if shown to be efficacious in animal models of contraception, could lead to a safe, simple and inexpensive method alternative to surgical contraception. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Properties of Syntactic Foam for Simulation of Mechanical Insults.

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, Neal Benson [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Haulenbeek, Kimberly K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Spletzer, Matthew A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ortiz, Lyndsy [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    Syntactic foam encapsulation protects sensitive components. The energy mitigated by the foam is calculated with numerical simulations. The properties of a syntactic foam consisting of a mixture of an epoxy-rubber adduct and glass microballoons are obtained from published literature and test results. The conditions and outcomes of the tests are discussed. The method for converting published properties and test results to input for finite element models is described. Simulations of the test conditions are performed to validate the inputs.

  2. Foams Stabilized with Nanoparticles for Gas Well Deliquification

    OpenAIRE

    Knapik Ewa; Stopa Jerzy; Marzec Anna

    2014-01-01

    This study examined the interaction of solid nanoparticles and anionic and non-ionic surfactant at an air–water interface. Aqueous foams stabilized by silica nanoparticles in water with different levels of salinity were studied in detail. The stability of solid/surfactant dispersion was evaluated visually. Nanoparticles content impact and concentration of surfactant on the foamability, deliquification of foams and structure of wet foams were studied. It was found that the foamability of dispe...

  3. Design and Synthesis of Hybrid Ceramic Foams with Tailored Porosity

    OpenAIRE

    Capasso, Ilaria

    2017-01-01

    Alkali activated ceramic foams have been produced by using metakaolin and/or diatomite as aluminosilicate source, an aqueous sodium silicate solution as alkali activator and Na2SiF6 as a catalyst that promotes the gelification of the entire system. Two different techniques of direct foaming have been coupled, one based on chemical reactions with gas production and the other one based on a mechanical foaming. Then, other levels of hierarchical porosity (nanometric and macrometric scale) have b...

  4. EMS providers do not use FOAM for education.

    Science.gov (United States)

    Bucher, Joshua; Donovan, Colleen; McCoy, Jonathan

    2018-05-24

    Free open access to medical education (FOAM, #FOAM) is the free availability of educational materials on various medicine topics. We hope to evaluate the use of social media and FOAM by emergency medical services (EMS) providers. We designed an online survey distributed to EMS providers with questions about demographics and social media/FOAM use by providers. The survey was sent to the American College of Emergency Physicians (ACEP) EMS Listserv of medical directors and was asked to be distributed to their respective agencies. The survey was designed to inquire about the providers' knowledge of FOAM and social media and their use of the above for EMS education. There were 169 respondents out of a total of 523 providers yielding a response rate of 32.3%. Fifty-three percent of respondents are paramedics, 37% are EMT-Basic trained, and the remainder (16%) were "other." The minority (20%) of respondents had heard of FOAM. However, 54% of respondents had heard of "free medical education online" regarding pertinent topics. Of the total respondents who used social media for education, 31% used Facebook and 23% used blogs and podcasts as resources for online education. Only 4% of respondents stated they produced FOAM content. Seventy-six percent of respondents said they were "interested" or "very interested" in using FOAM for medical education. If FOAM provided continuing medical education (CME), 83% of respondents would be interested in using it. Social media is not used frequently by EMS providers for the purposes of FOAM. There is interest within EMS providers to use FOAM for education, even if CME was not provided. FOAM can provide a novel area of education for EMS.

  5. The sedimentation of fine particles in liquid foams

    OpenAIRE

    Rouyer , Florence; Fritz , Christelle; Pitois , Olivier

    2010-01-01

    International audience; We investigate the sedimentation of fine particles in liquid channels of foams. The study combines numerical simulations with experiments performed in foams and in isolated vertical foam channels. Results show that particulate motion is controlled by the confinement parameter (l) and the mobility of the channel surfaces modelled by interfacial shear viscosity. Interestingly, whereas the position of the particle within the channel cross-section is expected to be a relev...

  6. Foam generation and sample composition optimization for the FOAM-C experiment of the ISS

    International Nuclear Information System (INIS)

    Carpy, R; Picker, G; Amann, B; Ranebo, H; Vincent-Bonnieu, S; Minster, O; Winter, J; Dettmann, J; Castiglione, L; Höhler, R; Langevin, D

    2011-01-01

    End of 2009 and early 2010 a sealed cell, for foam generation and observation, has been designed and manufactured at Astrium Friedrichshafen facilities. With the use of this cell, different sample compositions of 'wet foams' have been optimized for mixtures of chemicals such as water, dodecanol, pluronic, aethoxisclerol, glycerol, CTAB, SDS, as well as glass beads. This development is performed in the frame of the breadboarding development activities of the Experiment Container FOAM-C for operation in the ISS Fluid Science Laboratory (ISS). The sample cell supports multiple observation methods such as: Diffusing-Wave and Diffuse Transmission Spectrometry, Time Resolved Correlation Spectroscopy and microscope observation, all of these methods are applied in the cell with a relatively small experiment volume 3 . These units, will be on orbit replaceable sets, that will allow multiple sample compositions processing (in the range of >40).

  7. Foam generation and sample composition optimization for the FOAM-C experiment of the ISS

    Science.gov (United States)

    Carpy, R.; Picker, G.; Amann, B.; Ranebo, H.; Vincent-Bonnieu, S.; Minster, O.; Winter, J.; Dettmann, J.; Castiglione, L.; Höhler, R.; Langevin, D.

    2011-12-01

    End of 2009 and early 2010 a sealed cell, for foam generation and observation, has been designed and manufactured at Astrium Friedrichshafen facilities. With the use of this cell, different sample compositions of "wet foams" have been optimized for mixtures of chemicals such as water, dodecanol, pluronic, aethoxisclerol, glycerol, CTAB, SDS, as well as glass beads. This development is performed in the frame of the breadboarding development activities of the Experiment Container FOAM-C for operation in the ISS Fluid Science Laboratory (ISS). The sample cell supports multiple observation methods such as: Diffusing-Wave and Diffuse Transmission Spectrometry, Time Resolved Correlation Spectroscopy [1] and microscope observation, all of these methods are applied in the cell with a relatively small experiment volume 40).

  8. Preparation And Characterization Of Silicon Carbide Foam By Using In-Situ Generated Polyurethane Foam

    Directory of Open Access Journals (Sweden)

    Shalini Saxena

    2015-08-01

    Full Text Available Abstract The open cell silicon carbide SiC foam was prepared using highly crosslinked hybrid organic- inorganic polymer resin matrix. As inorganic polymer polycarbosilane was taken and organic resin was taken as a mixture of epoxy resin and diisocyanates. The resultant highly crosslinked hybrid resin matrix on heating and subsequently on pyrolysis yielded open cell silicon carbide foam. The hybrid resin matrix was characterized by Fourier transform Infrared Spectroscopy FT-IR and thermal properties i.e. Thermogravimetric analysis TGA amp Differential Scanning Calorimetry DSC were also studied. The morphological studies of silicon carbide ceramic foam were carried out using X-ray Spectroscopy XRD amp Scanning Electron Microscopy SEM.

  9. Refinement of Foam Backfill Technology for Expedient Airfield Damage Repair; Phase 2: Development of Prototype Foam Dispensing Equipment and Improved Tactics, Techniques and Procedures

    Science.gov (United States)

    2017-12-01

    ER D C TR -1 7- 14 U.S. Air Force Rapid Airfield Damage Repair Modernization Program Refinement of Foam Backfill Technology for...Backfill Technology for Expedient Airfield Damage Repair Phase II: Development of Prototype Foam Dispensing Equipment and Improved Tactics...procedures (TTPs) for rapid airfield damage repair (RADR) using foam backfill technology . Three different prototype foam dispensing systems were

  10. Studies on Foam Decay Trend and Influence of Temperature Jump on Foam Stability in Sclerotherapy.

    Science.gov (United States)

    Bai, Taoping; Chen, Yu; Jiang, Wentao; Yan, Fei; Fan, Yubo

    2018-02-01

    This study investigated the influence of temperature jump and liquid-gas ratio on foam stability to derive the foam-decay law. The experimental group conditions were as follows: mutation temperatures (10°C, 16°C, 20°C, 23°C, 25°C, and 27°C to >37°C) and liquid-gas ratios (1:1, 1:2, 1:3, and 1:4). The control group conditions were as follows: temperatures (10°C, 16°C, 20°C, 23°C, 25°C and 27°C) and liquid-gas ratios (1:1, 1:2, 1:3, and 1:4). A homemade device manufactured using the Tessari DSS method was used to prepare the foam. The decay process was videotape recorded. In the drainage rate curve, the temperature rose, and the liquid-gas ratio varied from 1:1 to 1:4, causing faster decay. In the entire process, the foam volume decreased with increasing drainage rate. The relationships were almost linear. Comparison of the experimental and control groups shows that the temperature jump results in a drainage time range of 1 to 15 seconds. The half-life ranges from 10 to 30 seconds. The maximum rate is 18.85%. Changes in the preparation temperature yields a drainage time range of 3 to 30 seconds. The half-life varies from 20 to 60 seconds. Decreasing the temperature jump range and liquid-gas ratio gradually enhances the foam stability. The foam decay time and drainage rate exhibit an exponential function distribution.

  11. Effect of silica nanoparticles on polyurethane foaming process and foam properties

    International Nuclear Information System (INIS)

    Francés, A B; Bañón, M V Navarro

    2014-01-01

    Flexible polyurethane foams (FPUF) are commonly used as cushioning material in upholstered products made on several industrial sectors: furniture, automotive seating, bedding, etc. Polyurethane is a high molecular weight polymer based on the reaction between a hydroxyl group (polyol) and isocyanate. The density, flowability, compressive, tensile or shearing strength, the thermal and dimensional stability, combustibility, and other properties can be adjusted by the addition of several additives. Nanomaterials offer a wide range of possibilities to obtain nanocomposites with specific properties. The combination of FPUF with silica nanoparticles could develop nanocomposite materials with unique properties: improved mechanical and thermal properties, gas permeability, and fire retardancy. However, as silica particles are at least partially surface-terminated with Si-OH groups, it was suspected that the silica could interfere in the reaction of poyurethane formation.The objective of this study was to investigate the enhancement of thermal and mechanical properties of FPUF by the incorporation of different types of silica and determining the influence thereof during the foaming process. Flexible polyurethane foams with different loading mass fraction of silica nanoparticles (0-1% wt) and different types of silica (non treated and modified silica) were synthesized. PU/SiO 2 nanocomposites were characterized by FTIR spectroscopy, TGA, and measurements of apparent density, resilience and determination of compression set. Addition of silica nanoparticles influences negatively in the density and compression set of the foams. However, resilience and thermal stability of the foams are improved. Silica nanoparticles do not affect to the chemical structure of the foams although they interfere in the blowing reaction

  12. Optimization of foam-filled bitubal structures for crashworthiness criteria

    International Nuclear Information System (INIS)

    Zhang, Yong; Sun, Guangyong; Li, Guangyao; Luo, Zhen; Li, Qing

    2012-01-01

    Highlights: ► The paper aims to optimize foam-filled bitubal squared column for crashworthiness. ► It explores different formulations and configurations of design. ► The optimal foam-filled bitubal column is better than foam-filled monotubal column. ► The optimal foam-filled bitubal column is better than empty bitubal column. -- Abstract: Thin-walled structures have been widely used as key components in automobile and aerospace industry to improve the crashworthiness and safety of vehicles while maintaining overall light-weight. This paper aims to explore the design issue of thin-walled bitubal column structures filled with aluminum foam. As a relatively new filler material, aluminum foam can increase crashworthiness without sacrificing too much weight. To optimize crashworthiness of the foam-filled bitubal square column, the Kriging meta-modeling technique is adopted herein to formulate the objective and constraint functions. The genetic algorithm (GA) and Non-dominated Sorting Genetic Algorithm II (NSGA II) are used to seek the optimal solutions to the single and multiobjective optimization problems, respectively. To compare with other thin-walled configurations, the design optimization is also conducted for empty bitubal column and foam-filled monotubal column. The results demonstrate that the foam-filled bitubal configuration has more room to enhance the crashworthiness and can be an efficient energy absorber.

  13. Numerical simulation of heat transfer in metal foams

    Science.gov (United States)

    Gangapatnam, Priyatham; Kurian, Renju; Venkateshan, S. P.

    2018-02-01

    This paper reports a numerical study of forced convection heat transfer in high porosity aluminum foams. Numerical modeling is done considering both local thermal equilibrium and non local thermal equilibrium conditions in ANSYS-Fluent. The results of the numerical model were validated with experimental results, where air was forced through aluminum foams in a vertical duct at different heat fluxes and velocities. It is observed that while the LTE model highly under predicts the heat transfer in these foams, LTNE model predicts the Nusselt number accurately. The novelty of this study is that once hydrodynamic experiments are conducted the permeability and porosity values obtained experimentally can be used to numerically simulate heat transfer in metal foams. The simulation of heat transfer in foams is further extended to find the effect of foam thickness on heat transfer in metal foams. The numerical results indicate that though larger foam thicknesses resulted in higher heat transfer coefficient, this effect weakens with thickness and is negligible in thick foams.

  14. Unified Creep Plasticity Damage (UCPD) Model for Rigid Polyurethane Foams.

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, Michael K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lu, Wei-Yang [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Scherzinger, William M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hinnerichs, Terry D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lo, Chi S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-06-01

    Numerous experiments were performed to characterize the mechanical response of several different rigid polyurethane foams (FR3712, PMDI10, PMDI20, and TufFoam35) to large deformation. In these experiments, the effects of load path, loading rate, and temperature were investigated. Results from these experiments indicated that rigid polyurethane foams exhibit significant volumetric and deviatoric plasticity when they are compressed. Rigid polyurethane foams were also found to be very strain-rate and temperature dependent. These foams are also rather brittle and crack when loaded to small strains in tension or to larger strains in compression. Thus, a new Unified Creep Plasticity Damage (UCPD) model was developed and implemented into SIERRA with the name Foam Damage to describe the mechanical response of these foams to large deformation at a variety of temperatures and strain rates. This report includes a description of recent experiments and experimental findings. Next, development of a UCPD model for rigid, polyurethane foams is described. Selection of material parameters for a variety of rigid polyurethane foams is then discussed and finite element simulations with the new UCPD model are compared with experimental results to show behavior that can be captured with this model.

  15. Experimental and numerical analysis of the drainage of aluminium foams

    International Nuclear Information System (INIS)

    Brunke, O; Hamann, A; Cox, S J; Odenbach, S

    2005-01-01

    Drainage is one of the driving forces for the temporal instability of molten metal foams. For usual aqueous foams this phenomenon is well examined and understood on both the experimental and the theoretical side. The situation is different for metallic foams. Due to their opaque nature, the observation of drainage is only possible by either measuring the density distribution of solidified samples ex situ or by x-ray or neutron radioscopy. Up to now there exists just one theoretical study describing the drainage behaviour of metallic foams incorporating the drainage equation, the temperature dependence of the viscosity and thermal transport. This paper will present results on the drainage behaviour of aluminium foams grown by a powder-metallurgical production route. For this purpose an experiment which allows the observation of drainage in cylindrical metal foam columns has been developed. Experimental density profiles after different drainage times are measured ex situ and compared to numerical results of the standard drainage equation for aqueous foams. This first comparison between the density redistribution of metallic aluminium foams and numerical solutions shows that the standard drainage equation can be used to explain the drainage behaviour of metallic foams

  16. Structural applications of metal foams considering material and geometrical uncertainty

    Science.gov (United States)

    Moradi, Mohammadreza

    Metal foam is a relatively new and potentially revolutionary material that allows for components to be replaced with elements capable of large energy dissipation, or components to be stiffened with elements which will generate significant supplementary energy dissipation when buckling occurs. Metal foams provide a means to explore reconfiguring steel structures to mitigate cross-section buckling in many cases and dramatically increase energy dissipation in all cases. The microstructure of metal foams consists of solid and void phases. These voids have random shape and size. Therefore, randomness ,which is introduced into metal foams during the manufacturing processes, creating more uncertainty in the behavior of metal foams compared to solid steel. Therefore, studying uncertainty in the performance metrics of structures which have metal foams is more crucial than for conventional structures. Therefore, in this study, structural application of metal foams considering material and geometrical uncertainty is presented. This study applies the Sobol' decomposition of a function of many random variables to different problem in structural mechanics. First, the Sobol' decomposition itself is reviewed and extended to cover the case in which the input random variables have Gaussian distribution. Then two examples are given for a polynomial function of 3 random variables and the collapse load of a two story frame. In the structural example, the Sobol' decomposition is used to decompose the variance of the response, the collapse load, into contributions from the individual input variables. This decomposition reveals the relative importance of the individual member yield stresses in determining the collapse load of the frame. In applying the Sobol' decomposition to this structural problem the following issues are addressed: calculation of the components of the Sobol' decomposition by Monte Carlo simulation; the effect of input distribution on the Sobol' decomposition

  17. Graphene foam as a biocompatible scaffold for culturing human neurons

    Science.gov (United States)

    Mattei, Cristiana; Nasr, Babak; Hudson, Emma J.; Alshawaf, Abdullah J.; Chana, Gursharan; Everall, Ian P.; Dottori, Mirella; Skafidas, Efstratios

    2018-01-01

    In this study, we explore the use of electrically active graphene foam as a scaffold for the culture of human-derived neurons. Human embryonic stem cell (hESC)-derived cortical neurons fated as either glutamatergic or GABAergic neuronal phenotypes were cultured on graphene foam. We show that graphene foam is biocompatible for the culture of human neurons, capable of supporting cell viability and differentiation of hESC-derived cortical neurons. Based on the findings, we propose that graphene foam represents a suitable scaffold for engineering neuronal tissue and warrants further investigation as a model for understanding neuronal maturation, function and circuit formation. PMID:29657752

  18. The effect of nanoparticle aggregation on surfactant foam stability.

    Science.gov (United States)

    AlYousef, Zuhair A; Almobarky, Mohammed A; Schechter, David S

    2018-02-01

    The combination of nanoparticles (NPs) and surfactant may offer a novel technique of generating stronger foams for gas mobility control. This study evaluates the potential of silica NPs to enhance the foam stability of three nonionic surfactants. Results showed that the concentration of surfactant and NPs is a crucial parameter for foam stability and that there is certain concentrations for strong foam generation. A balance in concentration between the nonionic surfactants and the NPs can enhance the foam stability as a result of forming flocs in solutions. At fixed surfactant concentration, the addition of NPs at low to intermediate concentrations can produce a more stable foam compared to the surfactant. The production of small population of flocs as a result of mixing the surfactant and NPs can enhance the foam stability by providing a barrier between the gas bubbles and delaying the coalescence of bubbles. Moreover, these flocs can increase the solution viscosity and, therefore, slow the drainage rate of thin aqueous film (lamellae). The measurements of foam half-life, bubble size, and mobility tests confirmed this conclusion. However, the addition of more solid particles or surfactant might have a negative impact on foam stability and reduce the maximum capillary pressure of coalescence as a result of forming extensive aggregates. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Effect of Cerium(IV)-Surfactant Reaction in Foam Decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Han Beom; Jung, Chong-Hun; Yoon, In-Ho; Kim, Chorong; Choi, Wang-Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Using foams allows the decommissioning of complex shaped facilities. The decontamination foam comprises at least one surfactant to generate the foam and one or more chemical reactants to achieve the dissolution of the contaminants at the solid surface. In order to improve the efficiency of decontamination foam, the present study attempts to find the optimum condition of chemical reagents to the foaming solution. The corrosion rate of radioactive nuclides contaminated stainless steel metal is very important factor for the foam decontamination process. The goal of this study is to develop the decontamination process for contaminated stainless steel in medium of nitric acid. Stainless steel needs a strong oxidizing agent such as Ce(IV) ion and the effects of cerium(IV). Surfactant interaction involved in foam decontamination and finally the improvement brought by formulation science. The formulation of foams loaded with strong oxidizing reagents such as Ce(IV) is an important factor. The enhanced decontamination properties of nitric acid with Ce(IV) additive on stainless steel is well known in liquid mediums. stainless steel metal is an important aspect in the foam decontamination process.

  20. Foam rheology in porous media and enhanced oil recovery potential

    International Nuclear Information System (INIS)

    Burley, R.

    1985-01-01

    Previous studies using foam as a mobility control agent in partially depleted oil wells have shown that foam has a potential for enhancing oil recovery after primary water flooding. The characteristics of foam as indicated by the results of several studies point to three potential applications of foam in oil recovery processes. These are: Improving the displacement efficiency of gas-drive processes (mobility control). Improving the sweep efficiency of other fluid injection processes (mobility control and flow impediment). Restricting the flow of undesired fluids and plugging of high permeable oil 'thief' zones (partial or total pore blockage). (author)

  1. Modification of Foamed Articles Based on Cassava Starch

    International Nuclear Information System (INIS)

    Ponce, P.

    2006-01-01

    This work reports the influence of radiation, plasticizers and poly vinyl alcohol (PVA) on the barrier properties [water vapour permeability (WVP)) and mechanical properties (tensile strength and elongation; compression resistance and flexibility) of foamed articles based on cassava starch. The starch foam was obtained by thermopressing process. Poly ethylene glycol (PEG, 300) was selected as plasticizer and water was necessary for the preparation of the foams. The foamed articles based on cassava starch were irradiated at low doses of 2 and 5 kGy, commonly used in food irradiation. The mechanical properties of starch foams are influenced by the plasticizer concentration and by irradiation dose. An increase in PEG content showed a considerable increase in elongation percentage and a decrease in the tensile strength of the foams; also increase the permeability of the foams in water. After irradiation, the barrier properties and mechanical properties of the foams were improved due to chemical reactions among polymer molecules. Irradiated starch cassava foams with poly vinyl alcohol (PVA) have good flexibility and low water permeability. WVP can be reduced by low doses of gamma radiation

  2. Biomass derived novel functional foamy materials - BIO-FOAM

    Energy Technology Data Exchange (ETDEWEB)

    Suurnaekki, A.; Boer, H.; Forssell, P. (and others) (VTT Technical Research Centre of Finland, Espoo (Finland)), Email: anna.suurnakki@vtt.fi

    2010-10-15

    BIO-FOAM has aimed at exploiting the potential of biomaterials in replacing synthetic polymers in solid foamy materials. The target applications have been various, including food, packaging, construction and insulation. The project activities during the second project year have focused on characterisation of the solid model foams and on modeling the behaviour of polymers at liquid- liquid interfaces. In the modelling study the intrinsic consistence of the applied thermodynamic approach was confirmed. The experimentally obtained solubility parameters of polymers were in good agreement with the calculated solubility parameters. The polymers were, however, found to posses too little surface activity to alone provide stable foams, but they were able to act as co-surfactants. In the model polymer foam work both expanded polymer foams and wood fibre based foams were prepared. Supercritical CO{sub 2}-gas chamber was found to be a useful tool to prepare expanded polymer foams in small scale. Only partial replacement of synthetic polymers could, however, be obtained with native biomaterials indicating the need of tailoring of biopolymer properties and suitable formulations including surfactants or stabilizing particles. In wood fibre-based foams both nanocellulose and lignin showed potential as additives or reinforcing components.The outcome of the extruded food snacks study was that the processing parameters were related with the equipmentvariables. Furthermore, glycerol was shown to facilitate greatly extrusion processing. In foam concrete work concrete pore structure was shown to correlate with its strength and stability. At optimum concentration wood fibres affected positively the concrete processing performance. (orig.)

  3. Effect of Cerium(IV)-Surfactant Reaction in Foam Decontamination

    International Nuclear Information System (INIS)

    Yang, Han Beom; Jung, Chong-Hun; Yoon, In-Ho; Kim, Chorong; Choi, Wang-Kyu

    2015-01-01

    Using foams allows the decommissioning of complex shaped facilities. The decontamination foam comprises at least one surfactant to generate the foam and one or more chemical reactants to achieve the dissolution of the contaminants at the solid surface. In order to improve the efficiency of decontamination foam, the present study attempts to find the optimum condition of chemical reagents to the foaming solution. The corrosion rate of radioactive nuclides contaminated stainless steel metal is very important factor for the foam decontamination process. The goal of this study is to develop the decontamination process for contaminated stainless steel in medium of nitric acid. Stainless steel needs a strong oxidizing agent such as Ce(IV) ion and the effects of cerium(IV). Surfactant interaction involved in foam decontamination and finally the improvement brought by formulation science. The formulation of foams loaded with strong oxidizing reagents such as Ce(IV) is an important factor. The enhanced decontamination properties of nitric acid with Ce(IV) additive on stainless steel is well known in liquid mediums. stainless steel metal is an important aspect in the foam decontamination process

  4. Implementing an exercise-training programme to prevent lower-limb injuries: considerations for the development of a randomised controlled trial intervention delivery plan.

    Science.gov (United States)

    Finch, Caroline F; White, Peta; Twomey, Dara; Ullah, Shahid

    2011-08-01

    To identify important considerations for the delivery of an exercise training intervention in a randomised controlled trial to maximise subsequent participation in that randomised controlled trial and intervention uptake. A cross-sectional survey, with a theoretical basis derived from the Health Belief Model (HBM) and the Reach, Efficacy/Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework. 374 male senior Australian Football players, aged 17-38 years. Beliefs about lower-limb injury causation/prevention, and the relative value of exercise training for performance and injury prevention. The data are interpreted within HBM constructs and implications for subsequent intervention implementation considered within the RE-AIM framework. Ordinal logistic regression compared belief scores across player characteristics. 74.4% of players agreed that doing specific exercises during training would reduce their risk of lower-limb injury and would be willing to undertake them. However, 64.1% agreed that training should focus more on improving game performance than injury prevention. Younger players (both in terms of age and playing experience) generally had more positive views. Players were most supportive of kicking (98.9%) and ball-handling (97.0%) skills for performance and warm-up runs and cool-downs (both 91.5%) for injury prevention. Fewer than three-quarters of all players believed that balance (69.2%), landing (71.3%) or cutting/stepping (72.8) training had injury-prevention benefits. Delivery of future exercise training programmes for injury prevention aimed at these players should be implemented as part of routine football activities and integrated with those as standard practice, as a means of associating them with training benefits for this sport.

  5. Design Method for Proportion of Cement-Foamed Asphalt Cold Recycled Mixture

    OpenAIRE

    Li Junxiao; Fu Wei; Zang Hechao

    2018-01-01

    Through foaming experiment of Zhongtai AH-70 asphalt, the best foaming temperature water consumption and influence factors of foamed asphalt’s foaming features are determined; By designing the proportion of foamed asphalt cold in-place recycled mixture combined with the water stability experiment, for this mixture the best foamed asphalt addition is 3%, and proportion of the mixture is RAP: fine aggregate: cement=75:23:2. Using SEM technology, the mechanism of increasing on the intensity of f...

  6. Polyethoxylated carboxylic surfactant for ion foam flotation: fundamental study from solution to foam

    International Nuclear Information System (INIS)

    Micheau, Cyril

    2013-01-01

    Ion foam flotation allows to concentrate ions in a foam phase formed by a soap. For classical systems, the strong interaction between ions and surfactant generally leads to the formation of precipitates and of froth. When the froth collapses, the solid residue thus recovered requires a recycling or conversion. In order to remedy this, the present work uses as collector a polyethoxylated carboxylic surfactant, AKYPO RO 90 VG, which forms soluble ion/surfactant complexes, even with multi-charge ions. This work presents a detailed study of the fundamental mechanisms that govern the extraction of ions by foaming. In the first part, surface activity and acid/base properties of the surfactant in solution are determined by combining numerous independent techniques which are pH-metric dosage, tensiometry and small angle scattering. The evolution of these properties in the presence of different nitrate salts (Nd, Eu, Ca, Sr, Cu, Li, Na, Cs) coupled with electrophoretic measurements give a first approach to selectivity. Finally, all of these data combined with a study of the formation of surfactant/ion complexes allow us to determine the speciation of Nd/AKYPO system as a function of pH. In the second part, the analysis of the foam by conductivity and neutron scattering provides information on the wetness and foam film thickness, parameters governing foam stability. The pH and the nature of the added ions, their number of charge and also their chemical nature thus appear to be major parameters that governed wetness and foam film thickness. The last part is devoted to the understanding of the ion extraction/separation experiments by flotation based on all previous results. It is shown that the flotation of neodymium is strongly related to its speciation, which could lead to its re-extraction or its flotation in precipitated form. It is shown that, neodymium induces a phenomenon of mono-charge ion depletion in the foam. This ionic specificity allows to consider the studied

  7. Development of rubidium and niobium containing plastic foams. Final report

    International Nuclear Information System (INIS)

    Botham, R.A.; McClung, C.E.; Schwendeman, J.I.

    1978-01-01

    Rubidium fluoride and niobium metal-containing foam samples (rods and sheets) were prepared using two foam sytems: (1) hydrophilic polyurethanes prepared from W.R. Grace Co.'s Hypol prepolymers and (2) polyimides prepared from Monsanto Company's Skybond polyimide resin. The first system was used only for preparation of rubidium fluoride-containing foams while the second was used for both rubidium fluoride and niobium-containing foams. The niobium metal could readily be incorporated into the polyimide foam during molding, to produce foam sheets of the required dimensions and density. The rubidium fluoride-containing polyimide foams were preferably prepared by first rendering the molded polyimide foam hydrophilic with a postcuring treatment, then absorbing the rubidium fluoride from water solution. Similarly, rubidium fluoride was absorbed into the hydrophilic polyurethanes from water solution. Since the high reactive rubidium metal could not be employed, rubidium fluoride, which is very hygroscopic, was used instead, primarily because of its high rubidium content (approximately 82 weight percent). This was important in view of the low total densities and the high weight percentage rubidium required in the foam samples. In addition, at the later request of LLL, a block of rigid Hypol hydrophilic polyurethane foam (with a density of approximately 0.04 g/cm 3 and cell sizes = or <0.2 mm) was prepared without any metal or metal compounds in it. Two shipments of foam samples, which met or closely approximated the project specifications, were submitted to LLL during the course of this project. Information on these samples is contained in Table 1. A complete description of their preparation is given in the Experimental Results and Discussion Section

  8. SU-F-T-387: A Novel Optimization Technique for Field in Field (FIF) Chestwall Radiation Therapy Using a Single Plan to Improve Delivery Safety and Treatment Planning Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Tabibian, A; Kim, A; Rose, J; Alvelo, M; Perel, C; Laiken, K; Sheth, N [Bayonne Medical Center, Bayonne, New Jersey (United States)

    2016-06-15

    Purpose: A novel optimization technique was developed for field-in-field (FIF) chestwall radiotherapy using bolus every other day. The dosimetry was compared to currently used optimization. Methods: The prior five patients treated at our clinic to the chestwall and supraclavicular nodes with a mono-isocentric four-field arrangement were selected for this study. The prescription was 5040 cGy in 28 fractions, 5 mm bolus every other day on the tangent fields, 6 and/or 10 MV x-rays, and multileaf collimation.Novelly, tangents FIF segments were forward planned optimized based on the composite bolus and non-bolus dose distribution simultaneously. The prescription was spilt into 14 fractions for both bolus and non-bolus tangents. The same segments and monitor units were used for the bolus and non-bolus treatment. The plan was optimized until the desired coverage was achieved, minimized 105% hotspots, and a maximum dose of less than 108%. Each tangential field had less than 5 segments.Comparison plans were generated using FIF optimization with the same dosimetric goals, but using only the non-bolus calculation for FIF optimization. The non-bolus fields were then copied and bolus was applied. The same segments and monitor units were used for the bolus and non-bolus segments. Results: The prescription coverage of the chestwall, as defined by RTOG guidelines, was on average 51.8% for the plans that optimized bolus and non-bolus treatments simultaneous (SB) and 43.8% for the plans optimized to the non-bolus treatments (NB). Chestwall coverage of 90% prescription averaged to 80.4% for SB and 79.6% for NB plans. The volume receiving 105% of the prescription was 1.9% for SB and 0.8% for NB plans on average. Conclusion: Simultaneously optimizing for bolus and non-bolus treatments noticeably improves prescription coverage of the chestwall while maintaining similar hotspots and 90% prescription coverage in comparison to optimizing only to non-bolus treatments.

  9. SU-F-T-387: A Novel Optimization Technique for Field in Field (FIF) Chestwall Radiation Therapy Using a Single Plan to Improve Delivery Safety and Treatment Planning Efficiency

    International Nuclear Information System (INIS)

    Tabibian, A; Kim, A; Rose, J; Alvelo, M; Perel, C; Laiken, K; Sheth, N

    2016-01-01

    Purpose: A novel optimization technique was developed for field-in-field (FIF) chestwall radiotherapy using bolus every other day. The dosimetry was compared to currently used optimization. Methods: The prior five patients treated at our clinic to the chestwall and supraclavicular nodes with a mono-isocentric four-field arrangement were selected for this study. The prescription was 5040 cGy in 28 fractions, 5 mm bolus every other day on the tangent fields, 6 and/or 10 MV x-rays, and multileaf collimation.Novelly, tangents FIF segments were forward planned optimized based on the composite bolus and non-bolus dose distribution simultaneously. The prescription was spilt into 14 fractions for both bolus and non-bolus tangents. The same segments and monitor units were used for the bolus and non-bolus treatment. The plan was optimized until the desired coverage was achieved, minimized 105% hotspots, and a maximum dose of less than 108%. Each tangential field had less than 5 segments.Comparison plans were generated using FIF optimization with the same dosimetric goals, but using only the non-bolus calculation for FIF optimization. The non-bolus fields were then copied and bolus was applied. The same segments and monitor units were used for the bolus and non-bolus segments. Results: The prescription coverage of the chestwall, as defined by RTOG guidelines, was on average 51.8% for the plans that optimized bolus and non-bolus treatments simultaneous (SB) and 43.8% for the plans optimized to the non-bolus treatments (NB). Chestwall coverage of 90% prescription averaged to 80.4% for SB and 79.6% for NB plans. The volume receiving 105% of the prescription was 1.9% for SB and 0.8% for NB plans on average. Conclusion: Simultaneously optimizing for bolus and non-bolus treatments noticeably improves prescription coverage of the chestwall while maintaining similar hotspots and 90% prescription coverage in comparison to optimizing only to non-bolus treatments.

  10. Churn-annular foam flow: experiments and modelling

    NARCIS (Netherlands)

    Westende, J.M.C. van 't; Shoeibi Omrani, P.; Vercauteren, F.F.; Nennie, E.D.

    2016-01-01

    Foam assisted lift is a deliquification method in the oil and gas industry, which aims to prevent or postpone countercurrent gas-liquid flow in maturing gas wells or to assist in removing downhole accumulated liquids. The creation of foam reduces the density of the liquid that needs to be

  11. Development of a phenomenological constitutive model for polyurethane foams

    International Nuclear Information System (INIS)

    Neilsen, M.K.; Morgan, H.S.; Krieg, R.D.; Yoshimura, H.R.

    1989-01-01

    Rigid, closed-cell, polyurethane foam is used in impact limiters in nuclear waste transport containers. During a hypothetical nuclear waste transport accident, the foam is expected to absorb a significant amount of impact energy by undergoing large inelastic volume reductions. Consequently, the crushing of polyurethane foams must be well characterized and accurately modeled to properly analyze a transport container accident. At the request of Sandia National Laboratories, a series of uniaxial, hydrostatic and triaxial compression tests on polyurethane foams were performed by the New Mexico Engineering Research Institute (NMERI). The combination of hydrostatic and triaxial tests was chosen to provide sufficient data to characterize both the volumetric and deviatoric behaviors of the foams and the coupling between the two responses. Typical results from the NMERI tests are included in this paper. A complete description of these tests can be found in Neilsen et al., 1987. Constitutive models that have been used in the past to model foam did not capture some important foam behaviors observed in the NMERI tests. Therefore, a new constitutive model for rigid, closed-cell, polyurethane foams was developed and implemented in two finite element codes. Development of the new model is discussed in this paper. Also, results from analyses with the new model and other constitutive models are presented to demonstrate differences between the various models. 4 refs., 6 figs., 1 tab

  12. CARBONIZED STARCH MICROCELLULAR FOAM-CELLULOSE FIBER COMPOSITE STRUCTURES

    Directory of Open Access Journals (Sweden)

    Andrew R. Rutledge

    2008-11-01

    Full Text Available The production of microporous carbon foams from renewable starch microcellular foam-fiber (SMCF-Fiber composites is described. Carbon foams are used in applications such as thermal insulation, battery electrodes, filters, fuel cells, and medical devices. SMCF-Fiber compos-ites were created from an aquagel. The water in the aquagel was exchanged with ethanol and then dried and carbonized. Higher amylose content starches and fiber contents of up to 4% improved the processability of the foam. The SMCF structure revealed agglomerates of swollen starch granules connected by a web of starch with pores in the 50-200 nanometer range. Heating the SMCF-fiber in a nitrogen atmosphere to temperatures between 350-700˚C produced carbon foams with a three-dimensional closed cell foam structure with cell diameters around 50 microns and pore walls around 1-3 microns. The stress versus strain compression data for carbonized samples displayed a linear elastic region and a plateau indicative of brittle crushing, typical of an elastic-brittle foam. The carbon foam products from these renew-able precursors are promising carbon structures with moderate strength and low density.

  13. Microbial analysis in biogas reactors suffering by foaming incidents

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; De Francisci, Davide; Treu, Laura

    2014-01-01

    , lipids and carbohydrates before and after foaming incidents was characterized using 16S rRNA gene sequencing. Moreover, the microbial diversity between the liquid and foaming layer was assessed. A number of genera that are known to produce biosurfactants, contain mycolic acid in their cell wall...

  14. Nanoparticle Stabilized Foam in Carbonate and Sandstone Reservoirs

    NARCIS (Netherlands)

    Roebroeks, J.; Eftekhari, A.A.; Farajzadeh, R.; Vincent-Bonnieu, S.

    2015-01-01

    Foam flooding as a mechanism to enhance oil recovery has been intensively studied and is the subject of multiple research groups. However, limited stability of surfactant-generated foam in presence of oil and low chemical stability of surfactants in the high temperature and high salinity of an oil

  15. Pitch-based carbon foam and composites and use thereof

    Science.gov (United States)

    Klett, James W.; Burchell, Timothy D.; Choudhury, Ashok

    2006-07-04

    A thermally conductive carbon foam is provided, normally having a thermal conductivity of at least 40 W/mK. The carbon foam usually has a specific thermal conductivity, defined as the thermal conductivity divided by the density, of at least about 75 Wcm.sup.3/m.degree. Kgm. The foam also has a high specific surface area, typically at least about 6,000 m.sup.2/m.sup.3. The foam is characterized by an x-ray diffraction pattern having "doublet" 100 and 101 peaks characterized by a relative peak split factor no greater than about 0.470. The foam is graphitic and exhibits substantially isotropic thermal conductivity. The foam comprises substantially ellipsoidal pores and the mean pore diameter of such pores is preferably no greater than about 340 microns. Other materials, such as phase change materials, can be impregnated in the pores in order to impart beneficial thermal properties to the foam. Heat exchange devices and evaporatively cooled heat sinks utilizing the foams are also disclosed.

  16. Pitch-based carbon foam and composites and uses thereof

    Science.gov (United States)

    Klett, James W.; Burchell, Timothy D.; Choudhury, Ashok

    2004-01-06

    A thermally conductive carbon foam is provided, normally having a thermal conductivity of at least 40 W/m.multidot.K. The carbon foam usually has a specific thermal conductivity, defined as the thermal conductivity divided by the density, of at least about 75 W.multidot.cm.sup.3 /m.multidot..degree.K.multidot.gm. The foam also has a high specific surface area, typically at least about 6,000 m.sup.2 /m.sup.3. The foam is characterized by an x-ray diffraction pattern having "doublet" 100 and 101 peaks characterized by a relative peak split factor no greater than about 0.470. The foam is graphitic and exhibits substantially isotropic thermal conductivity. The foam comprises substantially ellipsoidal pores and the mean pore diameter of such pores is preferably no greater than about 340 microns. Other materials, such as phase change materials, can be impregnated in the pores in order to impart beneficial thermal properties to the foam. Heat exchange devices and evaporatively cooled heat sinks utilizing the foams are also disclosed.

  17. Coupling between drainage and coarsening in wet foam

    Indian Academy of Sciences (India)

    Abstract. Drainage and coarsening are two coupled phenomena during the evolution of wet foam. We show the variation in the growth rate of bubble size, along the height in a column of Gillette shaving foam, by microscope imaging. Simultaneously, the drainage of liquid at the same heights has been investigated by ...

  18. Modyfication of the Rigid Polyurethane-Polyisocyanurate Foams

    Directory of Open Access Journals (Sweden)

    Bogusław Czupryński

    2014-01-01

    Full Text Available The effect of polyethylene glycol 1500 on physicomechanical properties of rigid polyurethane-polyisocyanurate (PUR-PIR foams has been studied. It was found that application of polyethylene glycol 1500 for synthesis of foams in amount from 0% to 20% w/w had an effect on reduction of brittleness and softening point, while the greater the increase in compressive strength the higher its content in foam composition was. Wastes from production of these foams were ground and subjected to glycolysis in diethylene glycol with the addition of ethanolamine and zinc stearate. Liquid brown products were obtained. Properties of the resulting products were defined in order to determine their suitability for synthesis of new foams. It was found that glycolysate 6 was the most suitable for reuse and its application in different amounts allowed us to prepare 4 new foams (nos. 25, 26, 27, and 28. Properties of foams prepared in this manner were determined and, on their basis, the suitability of glycolysates for production of rigid PUR-PIR foams was evaluated.

  19. RELATIONSHIP BETWEEN FOAMING BEHAVIOR AND SURFACE ENERGY OF ASPHALT BINDER

    Directory of Open Access Journals (Sweden)

    Jian-ping Xu

    2017-12-01

    Full Text Available To solve the problem of insufficiency in microscopic performance of foamed asphalt binder, surface energy theory was utilized to analyze the foaming behavior and wettability of asphalt binder. Based on the surface energy theory, the Wilhelmy plate method and universal sorption device method were employed to measure the surface energy components of asphalt binders and aggregates, respectively. Combined with the traditional evaluation indictor for foamed asphalt, the relationship between the foaming property and surface energy of asphalt binder was analyzed. According to the surface energy components, the wettability of asphalt binder to aggregate was calculated to verify the performance of foamed asphalt mixture. Results indicate that the foaming behavior of asphalt will be influenced by surface energy, which will increase with the decline of surface energy. In addition, the surface energy of asphalt binder significantly influences the wettability of asphalt binder to aggregates. Meanwhile, there is an inversely proportional relationship between surface energy of asphalt binder and wettability. Therefore, it can be demonstrated that surface energy is a good indictor which can be used to evaluate the foaming behavior of the asphalt binder. And it is suggested to choose the asphalt binder with lower surface energy in the process of design of foamed asphalt mixture.

  20. Compressive Behaviour and Energy Absorption of Aluminium Foam Sandwich

    Science.gov (United States)

    Endut, N. A.; Hazza, M. H. F. Al; Sidek, A. A.; Adesta, E. T. Y.; Ibrahim, N. A.

    2018-01-01

    Development of materials in automotive industries plays an important role in order to retain the safety, performance and cost. Metal foams are one of the idea to evolve new material in automotive industries since it can absorb energy when it deformed and good for crash management. Recently, new technology had been introduced to replace metallic foam by using aluminium foam sandwich (AFS) due to lightweight and high energy absorption behaviour. Therefore, this paper provides reliable data that can be used to analyze the energy absorption behaviour of aluminium foam sandwich by conducting experimental work which is compression test. Six experiments of the compression test were carried out to analyze the stress-strain relationship in terms of energy absorption behavior. The effects of input variables include varying the thickness of aluminium foam core and aluminium sheets on energy absorption behavior were evaluated comprehensively. Stress-strain relationship curves was used for energy absorption of aluminium foam sandwich calculation. The result highlights that the energy absorption of aluminium foam sandwich increases from 12.74 J to 64.42 J respectively with increasing the foam and skin thickness.