WorldWideScience

Sample records for unit molten wax

  1. Getting in shape: molten wax drop deformation and solidification at an immiscible liquid interface.

    Science.gov (United States)

    Beesabathuni, Shilpa N; Lindberg, Seth E; Caggioni, Marco; Wesner, Chris; Shen, Amy Q

    2015-05-01

    The controlled production of non-spherical shaped particles is important for many applications such as food processing, consumer goods, adsorbents, drug delivery, and optical sensing. In this paper, we investigated the deformation and simultaneous solidification of millimeter size molten wax drops as they impacted an immiscible liquid interface of higher density. By varying initial temperature and viscoelasticity of the molten drop, drop size, impact velocity, viscosity and temperature of the bath fluid, and the interfacial tension between the molten wax and bath fluid, spherical molten wax drops impinged on a cooling water bath and were arrested into non-spherical solidified particles in the form of ellipsoid, mushroom, disc, and flake-like shapes. We constructed cursory phase diagrams for the various particle shapes generated over a range of Weber, Capillary, Reynolds, and Stefan numbers, governed by the interfacial, inertial, viscous, and thermal effects. We solved a simplified heat transfer problem to estimate the time required to initiate the solidification at the interface of a spherical molten wax droplet and cooling aqueous bath after impact. By correlating this time with the molten wax drop deformation history captured from high speed imaging experiments, we elucidate the delicate balance of interfacial, inertial, viscous, and thermal forces that determine the final morphology of wax particles.

  2. Solvent Extraction of Some Lanthanides with Trioctylphosphine Oxide in Molten Paraffin Wax

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The extraction behavior of Ln(Ⅲ) (Ln=Nd, Sm, Tb and Yb) with trioctylphosphine oxide (TOPO) in molten paraffin wax has been studied. The effect of pH, TOPO concentration, medium, stirring time and the amount of salts added on the distribution of lanthanides between two phases were investigated. Two different compositions Ln(H2O)s€?(TOPO)2(OH)2NO3 (Ln=Nd and Sm) and Ln(H2O)s€?(TOPO)2(OH)(NO3)2 (Ln=Tb and Yb) were determined by slope analysis method. The equilibrium extraction constant Kex and pH1/2 value were calculated and the thermodynamic parameters were obtained from the dependence of Kex on the temperature.

  3. Molten solvent extraction behavior of trivalent La, Sm, Dy, and Yb withtri-n-butyl phosphate into molten paraffin wax at 60 ℃

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The extraction behavior of La3+, Sm3+, Dy3+, and Yb3+ in sodium acetate-acetic acid medium was studied with tri-n-butyl phosphate (TBP) at 60 ℃ using paraffin wax as a diluent. The extraction percentage is greater than 85% in the pH range of 6 to 8. The result of slope analysis method indicates that the compositions of the extracted species are different between the light and heavy rare earths. The formula of the extracted species is found to be La(TBP)(OH)(Ac)2for La3+ and Yb(TBP)(OH)3 for Yb3+. The effects of extracting time, the concentration of TBP in the organic phase and salts on the extraction efficiency were also discussed.

  4. Major design issues of molten carbonate fuel cell power generation unit

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.P.

    1996-04-01

    In addition to the stack, a fuel cell power generation unit requires fuel desulfurization and reforming, fuel and oxidant preheating, process heat removal, waste heat recovery, steam generation, oxidant supply, power conditioning, water supply and treatment, purge gas supply, instrument air supply, and system control. These support facilities add considerable cost and system complexity. Bechtel, as a system integrator of M-C Power`s molten carbonate fuel cell development team, has spent substantial effort to simplify and minimize these supporting facilities to meet cost and reliability goals for commercialization. Similiar to other fuels cells, MCFC faces design challenge of how to comply with codes and standards, achieve high efficiency and part load performance, and meanwhile minimize utility requirements, weight, plot area, and cost. However, MCFC has several unique design issues due to its high operating temperature, use of molten electrolyte, and the requirement of CO2 recycle.

  5. Development of a Parafin Wax deposition Unit for Fused Deposition Modelling (FDM)

    DEFF Research Database (Denmark)

    D'Angelo, Greta; Hansen, Hans Nørgaard; Pedersen, David Bue

    2014-01-01

    During the last decade Additive Manufacturing (AM) witnessed a big development in terms of technologies, processes and possibilities. However of materials and their use still represents a big challenge. In fact availability of materials is rather limited if compared to conventional manufacturing...... parts to subsequently use in a Lost Wax Casting process, multi-material Additive Manufacturing and the use of wax as support material during the production of complicated parts. Moreover it is believed that including waxes among the materials usable in FDM would promote new ways of using and exploring...... are tested iteratively by alternating different methods in order to find the best configuration. The use of an open source platform, namely a Reprap Prusa Mendel allows to perform quick changes to the system without significant modifications to the major frame of the machine. During the design of the new...

  6. Molten salt coal gasification process development unit. Phase 1. Volume 1. PDU operations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kohl, A.L.

    1980-05-01

    This report summarizes the results of a test program conducted on the Molten Salt Coal Gasification Process, which included the design, construction, and operation of a Process Development Unit. In this process, coal is gasified by contacting it with air in a turbulent pool of molten sodium carbonate. Sulfur and ash are retained in the melt, and a small stream is continuously removed from the gasifier for regeneration of sodium carbonate, removal of sulfur, and disposal of the ash. The process can handle a wide variety of feed materials, including highly caking coals, and produces a gas relatively free from tars and other impurities. The gasification step is carried out at approximately 1800/sup 0/F. The PDU was designed to process 1 ton per hour of coal at pressures up to 20 atm. It is a completely integrated facility including systems for feeding solids to the gasifier, regenerating sodium carbonate for reuse, and removing sulfur and ash in forms suitable for disposal. Five extended test runs were made. The observed product gas composition was quite close to that predicted on the basis of earlier small-scale tests and thermodynamic considerations. All plant systems were operated in an integrated manner during one of the runs. The principal problem encountered during the five test runs was maintaining a continuous flow of melt from the gasifier to the quench tank. Test data and discussions regarding plant equipment and process performance are presented. The program also included a commercial plant study which showed the process to be attractive for use in a combined-cycle, electric power plant. The report is presented in two volumes, Volume 1, PDU Operations, and Volume 2, Commercial Plant Study.

  7. Ear wax

    OpenAIRE

    Browning, George GG

    2008-01-01

    Ear wax only becomes a problem if it causes a hearing impairment, or other ear-related symptoms. Ear wax is more likely to accumulate and cause a hearing impairment when normal extrusion is prevented — for example, by hearing aids, or by the use of cotton buds to clean the ears.Ear wax can visually obscure the ear drum, and may need to be removed for diagnostic purposes.

  8. Shape-tunable wax microparticle synthesis via microfluidics and droplet impact.

    Science.gov (United States)

    Lee, Doojin; Beesabathuni, Shilpa N; Shen, Amy Q

    2015-11-01

    Spherical and non-spherical wax microparticles are generated by employing a facile two-step droplet microfluidic process which consists of the formation of molten wax microdroplets in a flow-focusing microchannel and their subsequent off-chip crystallization and deformation via microdroplet impingement on an immiscible liquid interface. Key parameters on the formation of molten wax microdroplets in a microfluidic channel are the viscosity of the molten wax and the interfacial tension between the dispersed and continuous fluids. A cursory phase diagram of wax morphology transition is depicted depending on the Capillary number and the Stefan number during the impact process. A combination of numerical simulation and analytical modeling is carried out to understand the physics underlying the deformation and crystallization process of the molten wax. The deformation of wax microdroplets is dominated by the viscous and thermal effects rather than the gravitational and buoyancy effects. Non-isothermal crystallization kinetics of the wax illustrates the time dependent thermal effects on the droplet deformation and crystallization. The work presented here will benefit those interested in the design and production criteria of soft non-spherical particles (i.e., alginate gels, wax, and polymer particles) with the aid of time and temperature mediated solidification and off-chip crosslinking.

  9. Molten Salt Coal Gasification Process Development Unit. Phase 2. Quarterly technical progress report No. 2, October-December 1980

    Energy Technology Data Exchange (ETDEWEB)

    Slater, M. H.

    1981-01-20

    This represents the second quarterly progress report on Phase 2 of the Molten Salt Coal Gasification Process Development Unit (PDU) Program. Phase 1 of this program started in March 1976 and included the design, construction, and initial operation of the PDU. On June 25, 1980, Phase 2 of the program was initiated. It covers a 1-year operations program utilizing the existing PDU and is planned to include five runs with a targeted total operating time of 9 weeks. During this report period, Run 6, the initial run of the Phase 2 program was completed. The gasification system was operated for a total of 95 h at pressures up to 10 atm. Average product gas HHV values of 100 Btu/scf were recorded during 10-atm operation, while gasifying coal at a rate of 1100 lb/h. The run was terminated when the melt overflow system plugged after 60 continuous hours of overflow. Following this run, melt withdrawal system revisions were made, basically by changing the orifice materials from Monofrax to an 80 Cobalt-20 Chromium alloy. By the end of the report period, the PDU was being prepared for Run 7.

  10. 75 FR 38121 - Petroleum Wax Candles From China

    Science.gov (United States)

    2010-07-01

    ... COMMISSION Petroleum Wax Candles From China AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty order on petroleum wax candles from China... antidumping duty order on petroleum wax candles from China would be likely to lead to continuation or...

  11. HL-20 Wax Model

    Science.gov (United States)

    1993-01-01

    A numerically machined wax pattern of the NASA HL-20 orbital re-entry lifting body was cut from a CAD/CAM file. This nine-inch wax model was later used in a lost wax investment casting process to replicate the pattern in ceramic for wind-tunnel aero-heating studies

  12. Crystallization Behavior of Waxes

    OpenAIRE

    Jana, Sarbojeet

    2016-01-01

    Partially hydrogenated oil (PHO) has no longer GRAS status. However, PHO is one of the important ingredients in bakery and confectionary industry and therefore the food industry is seeking for an alternative fat to replace PHO. Waxes have shown promise to fulfill that demand because of its easy availability and cheap in price. Waxes with high melting points (> 40 °C) help in the crystallization process when mixed with low melting point oils. A crystalline network is formed in this wax/oil cry...

  13. Sustained release tablet of theophylline by hot melt wax coating technology

    OpenAIRE

    Padsalgi Amol; Bidkar Sanjay; Jadhav Vijay; Sheladiya Deepak

    2008-01-01

    Coating is one of the effective method used for sustaining the release of dosage form. There are various hydrophilic and hydrophilic polymers which are use to sustain the drug release. Waxes are one of the material which can be use to coat the drug in order to control the release. Coating with waxes can be achieved by dissolving it in suitable solvent or by hot melt wax coating. Hot melt coating technique defined as the application of fine layer of coating material in molten state over the su...

  14. Influence of waxes remelting used in investment casting on their thermal properties and linear shrinkage

    Directory of Open Access Journals (Sweden)

    K. Grzeskowiak

    2015-04-01

    Full Text Available This paper presents the results of thermal properties and linear shrinkage of jewelry waxes utilized in investment casting. Three types of jewelry waxes were cyclically processed (by heating, holding in a molten state and coolingin the temperature range between 25 and 90 °C for about 7 hours. The samples were tested after 5th, 10th and 15thcycle. The remelting was designed to simulate the process of waxes reusability for production of patterns. Changes in thermal properties of waxes were determined using differential scanning calorimetry (DSC and linear shrinkage values were specified. The conducted examinations allowed to establish the way of multiple utilization of waxes in producing precise models.

  15. Dynamics of the Molten Contact Line

    Science.gov (United States)

    Sonin, Ain A.; Duthaler, Gregg; Liu, Michael; Torresola, Javier; Qiu, Taiqing

    1999-01-01

    The purpose of this program is to develop a basic understanding of how a molten material front spreads over a solid that is below its melting point, arrests, and freezes. Our hope is that the work will contribute toward a scientific knowledge base for certain new applications involving molten droplet deposition, including the "printing" of arbitrary three-dimensional objects by precise deposition of individual molten microdrops that solidify after impact. Little information is available at this time on the capillarity-driven motion and arrest of molten contact line regions. Schiaffino and Sonin investigated the arrest of the contact line of a molten microcrystalline wax spreading over a subcooled solid "target" of the same material. They found that contact line arrest takes place at an apparent liquid contact angle that depends primarily on the Stefan number S=c(T(sub f) -T(sub t)/L based on the temperature difference between the fusion point and the target temperature, and proposed that contact line arrest occurs when the liquid's dynamic contact angle approaches the angle of attack of the solidification front just behind the contact line. They also showed, however, that the conventional continuum equations and boundary conditions have no meaningful solution for this angle. The solidification front angle is determined by the heat flux just behind the contact line, and the heat flux is singular at that point. By comparing experiments with numerical computations, Schiaffino and Sonin estimated that the conventional solidification model must break down within a distance of order 0.1 - 1 microns of the contact line. The physical mechanism for this breakdown is as yet undetermined, and no first-principles theory exists for the contact angle at arrest. Schiaffino and Sonin also presented a framework for understanding how to moderate Weber number molten droplet deposition in terms of similarity laws and experimentation. The study is based on experiments with three molten

  16. Wax Point Determinations Using Acoustic Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bostick, D.T.; Jubin, R.T.; Schmidt, T.W.

    2001-06-01

    The thermodynamic characterization of the wax point of a given crude is essential in order to maintain flow conditions that prevent plugging of undersea pipelines. This report summarizes the efforts made towards applying an Acoustic Cavity Resonance Spectrometer (ACRS) to the determination of pressures and temperatures at which wax precipitates from crude. Phillips Petroleum Company, Inc., the CRADA participant, supplied the ACRS. The instrumentation was shipped to Dr. Thomas Schmidt of ORNL, the CRADA contractor, in May 2000 after preliminary software development performed under the guidance of Dr. Samuel Colgate and Dr. Evan House of the University of Florida, Gainesville, Fl. Upon receipt it became apparent that a number of modifications still needed to be made before the ACRS could be precisely and safely used for wax point measurements. This report reviews the sequence of alterations made to the ACRS, as well as defines the possible applications of the instrumentation once the modifications have been completed. The purpose of this Cooperative Research and Development Agreement (CRADA) between Phillips Petroleum Company, Inc. (Participant) and Lockheed Martin Energy Research Corporation (Contractor) was the measurement of the formation of solids in crude oils and petroleum products that are commonly transported through pipelines. This information is essential in the proper design, operation and maintenance of the petroleum pipeline system in the United States. Recently, new petroleum discoveries in the Gulf of Mexico have shown that there is a potential for plugging of undersea pipeline because of the precipitation of wax. It is important that the wax points of the expected crude oils be well characterized so that the production facilities for these new wells are capable of properly transporting the expected production. The goal of this work is to perform measurements of solids formation in crude oils and petroleum products supplied by the Participant. It is

  17. WAX ActiveLibrary: a tool to manage information overload.

    Science.gov (United States)

    Hanka, R; O'Brien, C; Heathfield, H; Buchan, I E

    1999-11-01

    WAX Active-Library (Cambridge Centre for Clinical Informatics) is a knowledge management system that seeks to support doctors' decision making through the provision of electronic books containing a wide range of clinical knowledge and locally based information. WAX has been piloted in several regions in the United Kingdom and formally evaluated in 17 GP surgeries based in Cambridgeshire. The evaluation has provided evidence that WAX Active-Library significantly improves GPs' access to relevant information sources and by increasing appropriate patient management and referrals this might also lead to an improvement in clinical outcomes.

  18. Organogel formation of soybean oil with waxes

    Science.gov (United States)

    Many waxes including plant waxes and animal waxes were evaluated for the gelation ability toward soybean oil (SBO) and compared with hydrogenated vegetable oils, petroleum waxes and commercial non-edible gelling agents to understand factors affecting the gelation ability of a gelator. Sunflower wax...

  19. Gases in molten salts

    CERN Document Server

    Tomkins, RPT

    1991-01-01

    This volume contains tabulated collections and critical evaluations of original data for the solubility of gases in molten salts, gathered from chemical literature through to the end of 1989. Within the volume, material is arranged according to the individual gas. The gases include hydrogen halides, inert gases, oxygen, nitrogen, hydrogen, carbon dioxide, water vapor and halogens. The molten salts consist of single salts, binary mixtures and multicomponent systems. Included also, is a special section on the solubility of gases in molten silicate systems, focussing on slags and fluxes.

  20. [Flow of molten metal in denture base in horizontal centrifugal casting procedure. (Part 1) Flow, inflow volume and casting time of molten metal passing through single aprue into disk type mold (author's transl)].

    Science.gov (United States)

    Okamura, H

    1976-01-01

    A pyrex glass plate was fitted at the bottom of casting ring, and disk type wax pattern (thickness. 0.43 mm) was put on the plate. Five types of sprueing were applied. Pure tin was casted using holizontal centrifugal casting machine. Flow of molten metal was filmed by the motor drive camera with the method of stroboscope. The results were summarized as follows. 1) When the sprue was attached at the center of the disk type mold vertically, moten metal flowed like a concentric circle at the early stage of casting. It was affected gradually by the direction of gravity and revolution, and it filled the mold from the lower part to the upper part. 2) When the sprue gate was attached to the side edge of the mold, and the sprue gate was placed to the forward and backward direction against the revolution direction, molten metal filled from lower part to the upper part. 3) When the sprue gate was placed against upper edge, molten metal flow was affected by the direction of gravity and revolution. When the sprue gate was placed against lower edge, molten metal filled quietry from the lower part to the upper part. 4) Inflow volume per unit time (inflow rate) was small at the early stage of casting. Inflow rate increased and became constant at the next stage. At the latter stage it became small again. 5) Inflow rate increased with the increase of area of sprue. 6) The time which was necessary to fill the volume of 1 cm (about 80% of the mold volume) became short with the increase of area of sprue. It was also influenced by the type of sprueing.

  1. Understanding wax screen-printing: a novel patterning process for microfluidic cloth-based analytical devices.

    Science.gov (United States)

    Liu, Min; Zhang, Chunsun; Liu, Feifei

    2015-09-01

    In this work, we first introduce the fabrication of microfluidic cloth-based analytical devices (μCADs) using a wax screen-printing approach that is suitable for simple, inexpensive, rapid, low-energy-consumption and high-throughput preparation of cloth-based analytical devices. We have carried out a detailed study on the wax screen-printing of μCADs and have obtained some interesting results. Firstly, an analytical model is established for the spreading of molten wax in cloth. Secondly, a new wax screen-printing process has been proposed for fabricating μCADs, where the melting of wax into the cloth is much faster (∼5 s) and the heating temperature is much lower (75 °C). Thirdly, the experimental results show that the patterning effects of the proposed wax screen-printing method depend to a certain extent on types of screens, wax melting temperatures and melting time. Under optimized conditions, the minimum printing width of hydrophobic wax barrier and hydrophilic channel is 100 μm and 1.9 mm, respectively. Importantly, the developed analytical model is also well validated by these experiments. Fourthly, the μCADs fabricated by the presented wax screen-printing method are used to perform a proof-of-concept assay of glucose or protein in artificial urine with rapid high-throughput detection taking place on a 48-chamber cloth-based device and being performed by a visual readout. Overall, the developed cloth-based wax screen-printing and arrayed μCADs should provide a new research direction in the development of advanced sensor arrays for detection of a series of analytes relevant to many diverse applications.

  2. Molten Metal Burns

    OpenAIRE

    Kahn, Arthur M.; McCrady-Kahn, Virginia L.

    1981-01-01

    Molten metal burns are a frequent industrial injury among workers in foundries. The injury is typically small but very deep. Usually the depth and seriousness of these injuries is not recognized immediately by emergency department or industrial clinic physicians.

  3. Properties of gastroretentive sustained release tablets prepared by combination of melt/sublimation actions of L-menthol and penetration of molten polymers into tablets.

    Science.gov (United States)

    Fukuda, Mamoru; Goto, Akinori

    2011-01-01

    A novel floating sustained release tablet having a cavity in the center was developed by utilizing the physicochemical properties of L-menthol and the penetration of molten hydrophobic polymer into tablets. A dry-coated tablet containing famotidine as a model drug in outer layer was prepared with a L-menthol core by direct compression. The tablet was placed in an oven at 80°C to remove the L-menthol core from tablet. The resulting tablet was then immersed in the molten hydrophobic polymers at 90°C. The buoyancy and drug release properties of tablets were investigated using United States Pharmacopeia (USP) 32 Apparatus 2 (paddle 100 rpm) and 900 ml of 0.01 N HCl. The L-menthol core in tablets disappeared completely through pathways in the outer layer with no drug outflows when placed in an oven for 90 min, resulting in a formation of a hollow tablet. The hollow tablets floated on the dissolution media for a short time and the drug release was rapid due to the disintegration of tablet. When the hollow tablets were immersed in molten hydrophobic polymers for 1 min, the rapid drug release was drastically retarded due to a formation of wax matrices within the shell of tablets and the tablets floated on the media for at least 6 h. When Lubri wax® was used as a polymer, the tablets showed the slowest sustained release. On the other hand, faster sustained release properties were obtained by using glyceryl monostearate (GMS) due to its low hydrophobic nature. The results obtained in this study suggested that the drug release rate from floating tablets could be controlled by both the choice of hydrophobic polymer and the combined use of hydrophobic polymers.

  4. Molten fatty acid based microemulsions.

    Science.gov (United States)

    Noirjean, Cecile; Testard, Fabienne; Dejugnat, Christophe; Jestin, Jacques; Carriere, David

    2016-06-21

    We show that ternary mixtures of water (polar phase), myristic acid (MA, apolar phase) and cetyltrimethylammonium bromide (CTAB, cationic surfactant) studied above the melting point of myristic acid allow the preparation of microemulsions without adding a salt or a co-surfactant. The combination of SANS, SAXS/WAXS, DSC, and phase diagram determination allows a complete characterization of the structures and interactions between components in the molten fatty acid based microemulsions. For the different structures characterized (microemulsion, lamellar or hexagonal phases), a similar thermal behaviour is observed for all ternary MA/CTAB/water monophasic samples and for binary MA/CTAB mixtures without water: crystalline myristic acid melts at 52 °C, and a thermal transition at 70 °C is assigned to the breaking of hydrogen bounds inside the mixed myristic acid/CTAB complex (being the surfactant film in the ternary system). Water determines the film curvature, hence the structures observed at high temperature, but does not influence the thermal behaviour of the ternary system. Myristic acid is partitioned in two "species" that behave independently: pure myristic acid and myristic acid associated with CTAB to form an equimolar complex that plays the role of the surfactant film. We therefore show that myristic acid plays the role of a solvent (oil) and a co-surfactant allowing the fine tuning of the structure of oil and water mixtures. This solvosurfactant behaviour of long chain fatty acid opens the way for new formulations with a complex structure without the addition of any extra compound.

  5. 21 CFR 178.3850 - Reinforced wax.

    Science.gov (United States)

    2010-04-01

    ... Type II Polyethylene Rosins and rosin derivatives as provided in § 178.3870 Synthetic wax polymer as... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Reinforced wax. 178.3850 Section 178.3850 Food and... and Production Aids § 178.3850 Reinforced wax. Reinforced wax may be safely used as an article or...

  6. Waxes as organogelator for soybean oil

    Science.gov (United States)

    This research reveals that a small amount of a food grade plant wax may replace a large amount of the hardstock containing trans-fat or saturated fat. Natural waxes including plant waxes and animal waxes were evaluated for the gelation ability toward soybean oil (SBO) and compared with hydrogenated ...

  7. Rheological characterization of dental waxes

    OpenAIRE

    Zhang, Kehao

    2004-01-01

    Objectives The purpose of this study was to evaluate the rheological behaviour of new experimental dental waxes in dependent on temperature. Material and method Seven experimental dental waxes, provided by Dentaurum GmbH, were tested. No.018 was chosen as a control. Rheological experiments were performed at different temperatures using a Paar Physica Rheometer UDS200 equiped with a parallel plate cell. The temperature was regulated with a Peltier system (TEK130P) and a thermostat un...

  8. Boiling wax burn in mid-autumn festival in Hong Kong.

    Science.gov (United States)

    Chan, E S; Chan, E C; Ho, W S; King, W W

    1997-01-01

    An unusual cause of burn, contact with boiling wax by children and adolescents during the annual mid-autumn festival in Hong Kong is presented. 57 patients who suffered from hot wax burn over the period 1986-1996 were admitted to the Burns Unit of the Prince of Wales Hospital. This special burn should be preventable by public education.

  9. The wax glands and wax secretion of Matsucoccus matsumurae at different development stages.

    Science.gov (United States)

    Xie, Yingping; Tian, Fen; Liu, Weimin; Zhang, Yanfeng; Xue, Jiaoliang; Zhao, Youyou; Wu, Jun

    2014-05-01

    In this paper, the wax secretions and wax glands of Matsucoccus matsumurae (Kuwana) at different instars were investigated using light microscopy, scanning electron microscopy and transmission electron microscopy. The first and second instar nymphs were found to secrete wax filaments via the wax glands located in the atrium of the abdominal spiracles, which have a center open and a series of outer ring pores. The wax gland of the abdominal spiracle possesses a large central wax reservoir and several wax-secreting cells. Third-instar male nymphs secreted long and translucent wax filaments from monolocular, biolocular, trilocular and quadrilocular pores to form twine into cocoons. The adult male secreted long and straight wax filaments in bundles from a group of 18-19 wax-secreting tubular ducts on the abdominal segment VII. Each tube duct contained five or six wax pores. The adult female has dorsal cicatrices distributed in rows, many biolocular tubular ducts and multilocular disc pores with 8-12 loculi secreting wax filaments that form the egg sac, and a rare type wax pores with 10 loculi secreting 10 straight, hollow wax filaments. The ultrastructure and cytological characteristics of the wax glands include wax-secreting cells with a large nucleus, multiple mitochondria and several rough endoplasmic reticulum. The functions of the wax glands and wax secretions are discussed.

  10. 2.2Mt/a蜡油加氢装置第一周期运行分析%Analysis of 1st operation cycle of a 2.2 MM TPY wax oil hydrotreating unit

    Institute of Scientific and Technical Information of China (English)

    陈雄; 田喜磊; 刘志博; 贺黎明

    2012-01-01

    介绍中国石油化工股份有限公司洛阳分公司2.2 Mt/a蜡油加氢装置第一周期运行情况.该装置采用抚顺石油化工研究院研制的新型FF-18( Ni-Mo/γ-Al2O3)催化剂,保护剂为FZC-100,FZC-102B,FZC-103,FZC-204.在装置处理量235 ~ 275 t/h下,反应器床层径向温差最大2.1℃,最小0.2℃,说明径向温度分布均匀、温差小、催化剂装填均匀、床层内的沟流效应很小.在反应器入口温度365℃,系统压力10.72 MPa下,催化剂在使用周期末期,反应器入口温度只比初期设计温度高8℃,而负荷率在104%情况下,平均脱硫率在80%以上,精制蜡油平均硫质量分数为0.138%,低于产品指标值(小于0.16%),说明新型催化剂FF-18相对活性仍然较高,稳定性较好.%The first operation cycle of a 2.2 wax oil hydrotreating unit in SINOPEC Luoyang Company is introduced. In this unit, the new FF-18 (Ni-Mo/y-Al2O3) catalyst and FZC-100, FZC-102B, FZC-103 and FZC-104 guard catalysts developed by SINOPEC Fushun Research Institute of Petroleum and Petrochemicals have been applied. When the unit was operating at a capacity of 235-275 t/h, the maximum radial temperature difference in reactor bed was 2. 1 ℃ and minimum temperature difference was 0. 2 ℃, which indicated that the radial temperature distribution was uniform and temperature difference was small. The catalyst loading was uniform and there was little catalyst channel. Under the conditions of 365 ℃ reactor inlet temperature and 10.72 MPa operating pressure, the EOR temperature of the catalyst was only 8 ℃ higher than that of SOR. When the unit was operating at 104% of the design capacity, the average sulfur removal rate was over 80% and sulfur in refined wax oil was 0. 138 w% which was lower than the product specifications (lower than 0. 16 w%. All these demonstrate that the FF-18 catalyst is high in activity and stable in performance.

  11. 影响蜡油加氢处理装置氢耗因素的分析%Analysis of factors affecting hydrogen consumption in wax oil hydrotreating unit

    Institute of Scientific and Technical Information of China (English)

    李明; 肖风良; 赵战东

    2012-01-01

    对中国石油化工股份有限公司洛阳分公司蜡油加氢处理装置影响氢耗的因素进行了分析并提出改进建议.结果表明:蜡油加氢处理装置氢耗随原料油密度、原料油硫含量和反应温度升高而增大.原料油密度在891~908 kg/m3时,化学氢耗为5.15 ~6.95 kg/t;原料油硫质量分数为0.674%~1.097%时,化学氢耗为4.25 ~6.28 kg/t;反应温度为299 ~337℃时,化学氢耗为5.31~5.90 kg/t.为了降低氢耗,热高压分离器温度选择在240 ~ 260℃,冷高压分离器操作温度控制在45 ~55℃,以降低循环氢溶解损失.同时,装置应定期进行闭灯检查以防止装置氢气泄漏.在满足生产的条件下,尽量减少排放废氢气.%The factors affecting the hydrogen consumption of wax oil hydrotreating unit in SINOPEC Luoyang Company are analyzed and effective measures are recommended. The results show that the hydrogen consumption of the wax oil hydrotreating unit increases with rise of feedstock density, sulfur in feedstock and reaction temperature. When the feedstock density is 891 -908 kg/m3, the chemical hydrogen consumption is 5. 15 ~ 6. 95 kg/t crude oil. When the sulfur in feedstock is 0. 674% ~ 1.097% , the chemical hydrogen consumption is 4.25 ~6. 28 kg/t crude oil. When reaction temperature is 299 ~ 337 t , the chemical hydrogen consumption is between 5. 31 and 5. 90 kg/t crude oil. To reduce hydrogen consumption, the 240 and 260 ℃ temperature should be selected for hot high-pressure separator and the operating temperature of cold or high-pressure separator should be controlled at 45 ℃ to 55 ℃ to reduce the loss of dissolved recycle hydrogen. In addition, the lights in the unit are tuned off for regular examination to prevent hydrogen from leaking from the unit. Waste hydrogen release should be minimized under operating conditions.

  12. Waxes in asphaltenes of crude oils and wax deposits

    Directory of Open Access Journals (Sweden)

    Yulia M. Ganeeva

    2016-07-01

    Full Text Available Abstract Composition and molecular mass distribution of n-alkanes in asphaltenes of crude oils of different ages and in wax deposits formed in the borehole equipment were studied. In asphaltenes, n-alkanes from C12 to C60 were detected. The high molecular weight paraffins in asphaltenes would form a crystalline phase with a melting point of 80–90 °C. The peculiarities of the redistribution of high molecular paraffin hydrocarbons between oil and the corresponding wax deposit were detected. In the oils, the high molecular weight paraffinic hydrocarbons C50–C60 were found, which were not practically detected in the corresponding wax deposits.

  13. Investigation of molten salt fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, Kenichi; Konomura, Mamoru [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan)

    2002-05-01

    On survey research for practicability strategy of fast reactor (FR) (phase 1), to extract future practicability image candidates of FR from wide options, in addition to their survey and investigation objects of not only solid fuel reactors of conventional research object but also molten salt reactor as a flowing fuel reactor, investigation on concept of molten salt FR plant was carried out. As a part of the first step of the survey research for practicability strategy, a basic concept on plant centered at nuclear reactor facility using chloride molten salt reactor capable of carrying out U-Pu cycle was examined, to perform a base construction to evaluate economical potential for a practical FBR. As a result, a result could be obtained that because of inferior fuel inventory and heat transmission to those in Na cooling reactor in present knowledge, mass of reactor vessel and intermediate heat exchanger were to widely increased to expect reduction of power generation unit price even on considering cheapness of its fuel cycle cost. Therefore, at present step further investigation on concept design of the chloride molten salt reactor plant system is too early in time, and it is at a condition where basic and elementary researches aiming at upgrading of economical efficiency such as wide reduction of fuel inventory, a measure expectable for remarkable rationalization effect of reprocessing system integrating a reactor to a processing facility, and so on. (G.K.)

  14. Septal splint with wax plates.

    Directory of Open Access Journals (Sweden)

    Nayak D

    1995-07-01

    Full Text Available To pack or not to pack, has always been a debate, especially after septal and functional endoscopic sinus surgery. The authors have studied the symptoms of packing versus not packing in their series of 100 patients having undergone nasal surgery. They advocate the use of dental wax for the fashioning of septal splints, since they are easy to introduce, cheap and malleable. The patients postoperative comfort is greatly enhanced with the use of dental wax plate splints instead of nasal packing.

  15. Margarine from organogels of plant wax and soybean oil

    Science.gov (United States)

    Organogels obtained from plant wax and soybean oil tested for suitability for incorporation into margarine. Sunflower wax, rice bran wax and candelilla wax were evaluated. Candelilla wax showed phase separation after making the emulsion with the formulation used in this study. Rice bran wax showe...

  16. 21 CFR 178.3710 - Petroleum wax.

    Science.gov (United States)

    2010-04-01

    ... CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3710 Petroleum wax. Petroleum wax may be safely used as a component of nonfood articles in contact with food, in accordance with the following conditions: (a) Petroleum wax is...

  17. 21 CFR 582.1978 - Carnauba wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carnauba wax. 582.1978 Section 582.1978 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1978 Carnauba wax. (a) Product. Carnauba wax. (b) Conditions of use. This substance is...

  18. Molten carbonate fuel cell

    Science.gov (United States)

    Kaun, T.D.; Smith, J.L.

    1986-07-08

    A molten electrolyte fuel cell is disclosed with an array of stacked cells and cell enclosures isolating each cell except for access to gas manifolds for the supply of fuel or oxidant gas or the removal of waste gas. The cell enclosures collectively provide an enclosure for the array and effectively avoid the problems of electrolyte migration and the previous need for compression of stack components. The fuel cell further includes an inner housing about and in cooperation with the array enclosure to provide a manifold system with isolated chambers for the supply and removal of gases. An external insulated housing about the inner housing provides thermal isolation to the cell components.

  19. Investigating molecular interactions and surface morphology of wax-doped asphaltenes.

    Science.gov (United States)

    Pahlavan, Farideh; Mousavi, Masoumeh; Hung, Albert; Fini, Ellie H

    2016-04-07

    The nature and origin of bee-like microstructures (bees) in asphalt binders and their impact on asphalt oxidation have been the subject of extensive discussions in recent years. While several studies refer to the bees as solely surface features, some others consider them to be bulk microcrystalline components that are formed due to co-precipitation of wax and asphaltene molecules. In this study, we use a rigorous theoretical and experimental approach to investigate the interplay of asphalt components (mainly asphaltene and wax) and their impact on bee formation. In the theoretical section, quantum-mechanical calculations using density functional theory (DFT) are used to evaluate the strength of interactions between asphaltene unit sheets in the presence and absence of a wax component, as well as the mutual interactions between asphaltene molecules (monomers and dimers) and paraffin wax. The results of this section reveal that paraffin waxes not only do not reinforce the interaction between the asphaltene unit sheets, they destabilize asphaltene assembly and dimerization. AIM (Atom in Molecules) analysis shows the destabilizing effect of wax on asphaltene assembly as a reduction in the number of cage and bond critical points between asphaltenes. This destabilization effect among interacting systems (asphaltene-asphaltene and wax-asphaltene) does not support the hypothesis that interaction between paraffin waxes and non-wax components, such as asphaltene, is responsible for their co-precipitation and bee formation. To further examine the effect of wax component on asphalt microstructure experimentally, we used atomic force microscopy (AFM) to study the surface morphology of an asphalt sample doped with 1% to 25% paraffin wax. In agreement with the conclusions drawn from the DFT approach, our experiments indicate that paraffin wax tends to crystallize separately and form lamellar paraffin wax crystal inclusions with 10 nm thickness. Moreover, the addition of 3% wax

  20. Limestone or Wax?

    Science.gov (United States)

    Sargianis, Kristin; Lachapelle, Cathy P.; Cunningham, Christine M.; Facchiano, Jean; Sanderson, Cheryl; Slater, Patricia

    2012-01-01

    In this article, the authors focus on an Engineering is Elementary unit that emphasizes students' understanding and application of properties of materials in the context of an engineering design challenge. Students build understanding through a series of hands-on activities, then apply their knowledge to solve a materials engineering problem:…

  1. Removing Dross From Molten Solder

    Science.gov (United States)

    Webb, Winston S.

    1990-01-01

    Automatic device helps to assure good solder connections. Machine wipes dross away from area on surface of molten solder in pot. Sweeps across surface of molten solder somewhat in manner of windshield wiper. Each cycle of operation triggered by pulse from external robot. Equipment used wherever precise, automated soldering must be done to military specifications.

  2. Structural features of reconstituted wheat wax films.

    Science.gov (United States)

    Pambou, Elias; Li, Zongyi; Campana, Mario; Hughes, Arwel; Clifton, Luke; Gutfreund, Philipp; Foundling, Jill; Bell, Gordon; Lu, Jian R

    2016-07-01

    Cuticular waxes are essential for the well-being of all plants, from controlling the transport of water and nutrients across the plant surface to protecting them against external environmental attacks. Despite their significance, our current understanding regarding the structure and function of the wax film is limited. In this work, we have formed representative reconstituted wax film models of controlled thicknesses that facilitated an ex vivo study of plant cuticular wax film properties by neutron reflection (NR). Triticum aestivum L. (wheat) waxes were extracted from two different wheat straw samples, using two distinct extraction methods. Waxes extracted from harvested field-grown wheat straw using supercritical CO2 are compared with waxes extracted from laboratory-grown wheat straw via wax dissolution by chloroform rinsing. Wax films were produced by spin-coating the two extracts onto silicon substrates. Atomic force microscopy and cryo-scanning electron microscopy imaging revealed that the two reconstituted wax film models are ultrathin and porous with characteristic nanoscale extrusions on the outer surface, mimicking the structure of epicuticular waxes found upon adaxial wheat leaf surfaces. On the basis of solid-liquid and solid-air NR and ellipsometric measurements, these wax films could be modelled into two representative layers, with the diffuse underlying layer fitted with thicknesses ranging from approximately 65 to 70 Å, whereas the surface extrusion region reached heights exceeding 200 Å. Moisture-controlled NR measurements indicated that water penetrated extensively into the wax films measured under saturated humidity and under water, causing them to hydrate and swell significantly. These studies have thus provided a useful structural basis that underlies the function of the epicuticular waxes in controlling the water transport of crops.

  3. Waxes and asphaltenes in crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Thanh, N.X. [Branch of Vietnam Petroleum Institute, Ho Chi Min City (Viet Nam). Dept. of Geochemistry; Hsieh, M.; Philp, R.P. [University of Oklahoma, Norman, OK (United States). School of Geology and Geophysics

    1999-07-01

    High molecular weight (HMW) hydrocarbons (> C{sub 40}) and asphaltenes are important constituents of petroleum, and can cause problems related to crystallization and deposition of paraffin waxes during production and transportation, as well as in the formation of tar mats. However, traditional methods to isolate asphaltene fractions, by adding 40 volumes in excess of low boiling point solvents such as pentane, hexane or heptane, can produce asphaltene fractions which are contaminated with a significant amount of microcrystalline waxes (> C{sub 40}). The presence of these microcrystalline waxes in the asphaltene fractions has the potential to provide misleading and ambiguous results in modeling and treatment programs. The sub-surface phase behaviour of an asphaltene fraction will be quite different from that of a wax-contaminated asphaltene fraction. Similarly accurate modelling of wax drop-out requires information on pure wax fractions and not asphaltene-dominated fractions. Hence the aim of this paper is to describe a novel method for the preparation of wax-free asphaltene fractions. In addition, this method provides a quantitative subdivision of the wax fraction into pentane soluble and insoluble waxes which, when correlated with physical properties of crude oil such as viscosity, pour point, cloud point, etc., may help explain causes of wax deposition during production, transportation and storage of petroleum. (author)

  4. Novel waste printed circuit board recycling process with molten salt.

    Science.gov (United States)

    Riedewald, Frank; Sousa-Gallagher, Maria

    2015-01-01

    The objective of the method was to prove the concept of a novel waste PCBs recycling process which uses inert, stable molten salts as the direct heat transfer fluid and, simultaneously, uses this molten salt to separate the metal products in either liquid (solder, zinc, tin, lead, etc.) or solid (copper, gold, steel, palladium, etc.) form at the operating temperatures of 450-470 °C. The PCB recovery reactor is essentially a U-shaped reactor with the molten salt providing a continuous fluid, allowing molten salt access from different depths for metal recovery. A laboratory scale batch reactor was constructed using 316L as suitable construction material. For safety reasons, the inert, stable LiCl-KCl molten salts were used as direct heat transfer fluid. Recovered materials were washed with hot water to remove residual salt before metal recovery assessment. The impact of this work was to show metal separation using molten salts in one single unit, by using this novel reactor methodology. •The reactor is a U-shaped reactor filled with a continuous liquid with a sloped bottom representing a novel reactor concept.•This method uses large PCB pieces instead of shredded PCBs as the reactor volume is 2.2 L.•The treated PCBs can be removed via leg B while the process is on-going.

  5. 21 CFR 186.1555 - Japan wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Japan wax. 186.1555 Section 186.1555 Food and Drugs... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan...

  6. Electrolysis of a molten semiconductor

    Science.gov (United States)

    Yin, Huayi; Chung, Brice; Sadoway, Donald R.

    2016-08-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

  7. The WAXS/WFXT Mission

    CERN Document Server

    Chincarini, G L

    1999-01-01

    I present the science goals and give a brief summary of the Wide Angle X-ray survey with a Wide Field X-ray Telescope (WAXS/WFXT) mission proposal (Phase A) which will be submitted to the Italian Space Agency (ASI) following the call for proposal under the Small Satellite program. The text points out the uniqueness of the mission for the study of the evolution of clusters of galaxies and of the Large-Scale Structure at large redshifts and for the study of the Milky Way. I present, furthermore, the successful result of the metrology of the first wide field X-ray optics ever made.

  8. Wax deposition in crude oil pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Assuncao, Pablo Morelato; Rodrigues, Lorennzo Marrochi Nolding [Universidade Federal do Espirito Santo, Sao Mateus, ES (Brazil). Centro Universitario Norte do Espirito Santo. Engenharia de Petroleo; Romero, Mao Ilich [University of Wyoming, Laramie, WY (United States). Enhanced Oil Recovery Institute], e-mail: mromerov@uwyo.edu

    2010-07-01

    Crude oil is a complex mixture of hydrocarbons which consists of aromatics, paraffins, naphthenics, resins asphaltenes, etc. When the temperature of crude oil is reduced, the heavy components, like paraffin, will precipitate and deposit on the pipe internal wall in the form of a wax-oil gel. The gel deposit consists of wax crystals that trap some amount of oil. As the temperature gets cooler, more wax will precipitate and the thickness of the wax gel will increase, causing gradual solidification of the crude and eventually the oil stop moving inside the offshore pipeline. Crude oil may not be able to be re-mobilized during re-startup. The effective diameter will be reduced with wax deposition, resulting in several problems, for example, higher pressure drop which means additional pumping energy costs, poor oil quality, use of chemical components like precipitation inhibitors or flowing facilitators, equipment failure, risk of leakage, clogging of the ducts and process equipment. Wax deposition problems can become so sever that the whole pipeline can be completely blocked. It would cost millions of dollars to remediate an offshore pipeline that is blocked by wax. Wax solubility decreases drastically with decreasing temperature. At low temperatures, as encountered in deep water production, is easy to wax precipitate. The highest temperature below which the paraffins begins to precipitate as wax crystals is defined as wax appearance temperature (WAT). Deposition process is a complex free surface problem involving thermodynamics, fluid dynamics, mass and heat transfer. In this work, a numerical analysis of wax deposition by molecular diffusion and shear dispersion mechanisms in crude oil pipeline is studied. Diffusion flux of wax toward the wall is estimated by Fick's law of diffusion, in similar way the shear dispersion; wax concentration gradient at the solid-liquid interface is obtained by the volume fraction conservation equation; and since the wax deposition

  9. Aplikasi Wax Sebagai Salah Satu Material Di Bidang Kedokteran Gigi

    OpenAIRE

    2008-01-01

    Wax merupakan salah satu bahan termoplastik yang terdiri dari berbagai bahan organis dan bahan alami sehingga membuatnya sebagai bahan dengan sifat-sifat yang sangat berguna. Unsur-unsur pokok dental wax terdiri dari 3 suraber utama, yaitu : mineral, serangga (hewani), dan sayur-sayuran (tumbuh-tumbuhan). Wax yang berasal dari bahan mineral diantaranya adalah paraffin wax dan microcrystallin wax yang diperoleh dari hasil residu petroleum melalui proses destilasi. Wax yang berasal dari serangg...

  10. Molten metal injector system and method

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Thomas N. (Murrysville, PA); Kinosz, Michael J. (Apollo, PA); Bigler, Nicolas (Morin Heights, CA); Arnaud, Guy (Riviere-Beaudette, CA)

    2003-04-01

    Disclosed is a molten metal injector system including a holder furnace, a casting mold supported above the holder furnace, and a molten metal injector supported from a bottom side of the mold. The holder furnace contains a supply of molten metal having a metal oxide film surface. The bottom side of the mold faces the holder furnace. The mold defines a mold cavity for receiving the molten metal from the holder furnace. The injector projects into the holder furnace and is in fluid communication with the mold cavity. The injector includes a piston positioned within a piston cavity defined by a cylinder for pumping the molten metal upward from the holder furnace and injecting the molten metal into the mold cavity under pressure. The piston and cylinder are at least partially submerged in the molten metal when the holder furnace contains the molten metal. The cylinder further includes a molten metal intake for receiving the molten metal into the piston cavity. The molten metal intake is located below the metal oxide film surface of the molten metal when the holder furnace contains the molten metal. A method of injecting molten metal into a mold cavity of a casting mold is also disclosed.

  11. Rifts in spreading wax layers

    CERN Document Server

    Ragnarsson, R; Santangelo, C D; Bodenschatz, E; Ragnarsson, Rolf; Ford, J Lewis; Santangelo, Christian D; Bodenschatz, Eberhard

    1995-01-01

    We report experimental results on the rift formation between two freezing wax plates. The plates were pulled apart with constant velocity, while floating on the melt, in a way akin to the tectonic plates of the earth's crust. At slow spreading rates, a rift, initially perpendicular to the spreading direction, was found to be stable, while above a critical spreading rate a "spiky" rift with fracture zones almost parallel to the spreading direction developed. At yet higher spreading rates a second transition from the spiky rift to a zig-zag pattern occurred. In this regime the rift can be characterized by a single angle which was found to be dependent on the spreading rate. We show that the oblique spreading angles agree with a simple geometrical model. The coarsening of the zig-zag pattern over time and the three-dimensional structure of the solidified crust are also discussed.

  12. Fluorescent Molecular Rotor-in-Paraffin Waxes for Thermometry and Biometric Identification.

    Science.gov (United States)

    Jin, Young-Jae; Dogra, Rubal; Cheong, In Woo; Kwak, Giseop

    2015-07-08

    Novel thermoresponsive sensor systems consisting of a molecular rotor (MR) and paraffin wax (PW) were developed for various thermometric and biometric identification applications. Polydiphenylacetylenes (PDPAs) coupled with long alkyl chains were used as MRs, and PWs of hydrocarbons having 16-20 carbons were utilized as phase-change materials. The PDPAs were successfully dissolved in the molten PWs and did not act as an impurity that prevents phase transition of the PWs. These PDPA-in-PW hybrids had almost the same enthalpies and phase-transition temperatures as the corresponding pure PWs. The hybrids exhibited highly reversible fluorescence (FL) changes at the critical temperatures during phase transition of the PWs. These hybrids were impregnated into common filter paper in the molten state by absorption or were encapsulated into urea resin to enhance their mechanical integrity and cyclic stability during repeated use. The wax papers could be utilized in highly advanced applications including FL image writing/erasing, an array-type thermo-indicator, and fingerprint/palmprint identification. The present findings should facilitate the development of novel fluorescent sensor systems for biometric identification and are potentially applicable for biological and biomedical thermometry.

  13. 21 CFR 872.6890 - Intraoral dental wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraoral dental wax. 872.6890 Section 872.6890...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6890 Intraoral dental wax. (a) Identification. Intraoral dental wax is a device made of wax intended to construct patterns from which custom made...

  14. 21 CFR 178.3720 - Petroleum wax, synthetic.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Petroleum wax, synthetic. 178.3720 Section 178.3720... Certain Adjuvants and Production Aids § 178.3720 Petroleum wax, synthetic. Synthetic petroleum wax may be... the synthetic petroleum wax meets the definition and specifications prescribed in § 172.888 of this...

  15. 21 CFR 172.888 - Synthetic petroleum wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Synthetic petroleum wax. 172.888 Section 172.888... CONSUMPTION Multipurpose Additives § 172.888 Synthetic petroleum wax. Synthetic petroleum wax may be safely used in or on foods in accordance with the following conditions: (a) Synthetic petroleum wax is a...

  16. Stability of Molten Core Materials

    Energy Technology Data Exchange (ETDEWEB)

    Layne Pincock; Wendell Hintze

    2013-01-01

    The purpose of this report is to document a literature and data search for data and information pertaining to the stability of nuclear reactor molten core materials. This includes data and analysis from TMI-2 fuel and INL’s LOFT (Loss of Fluid Test) reactor project and other sources.

  17. Electrolysis of a molten semiconductor

    Science.gov (United States)

    Yin, Huayi; Chung, Brice; Sadoway, Donald R.

    2016-01-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides. PMID:27553525

  18. Tectonic microplates: laying it down on wax

    Science.gov (United States)

    Katz, R. R.; Bodenschatz, E.

    2008-12-01

    We present a wax analogue model of sea-floor spreading that produces rotating, growing microplates. Wax microplates are kinematically similar to sea-floor tectonic microplates in terms of spreading rate and growth rate. Furthermore, their spiral pseudofault geometry is quantitatively consistent with Schouten's oceanic microplate model. These results suggest that Schouten's edge-driven microplate model captures the kinematics of tectonic microplate evolution on Earth. We propose a theory for the formation of microplates.

  19. Wax-bonding 3D microfluidic chips

    KAUST Repository

    Gong, Xiuqing

    2013-10-10

    We report a simple, low-cost and detachable microfluidic chip incorporating easily accessible paper, glass slides or other polymer films as the chip materials along with adhesive wax as the recycling bonding material. We use a laser to cut through the paper or film to form patterns and then sandwich the paper and film between glass sheets or polymer membranes . The hot-melt adhesive wax can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate (PMMA) film, glass sheets, or metal plate. The bonding process is reversible and the wax is reusable through a melting and cooling process. With this process, a three-dimensional (3D) microfluidic chip is achievable by vacuating and venting the chip in a hot-water bath. To study the biocompatibility and applicability of the wax-based microfluidic chip, we tested the PCR compatibility with the chip materials first. Then we applied the wax-paper based microfluidic chip to HeLa cell electroporation (EP ). Subsequently, a prototype of a 5-layer 3D chip was fabricated by multilayer wax bonding. To check the sealing ability and the durability of the chip, green fluorescence protein (GFP) recombinant Escherichia coli (E. coli) bacteria were cultured, with which the chemotaxis of E. coli was studied in order to determine the influence of antibiotic ciprofloxacin concentration on the E. coli migration.

  20. Heat transfer enhancement in energy storage in spherical capsules filled with paraffin wax and metal beads

    Energy Technology Data Exchange (ETDEWEB)

    Ettouney, Hisham; Alatiqi, Imad; Al-Sahali, Mohammad; Al-Hajirie, Khalida [Kuwait University, Safat (Kuwait). College of Engineering and Petroleum, Department of Chemical Engineering

    2006-01-15

    Energy storage is an attractive option to conserve limited energy resources, where more than 50% of the generated industrial energy is discarded in cooling water and stack gases. This study focuses on the evaluation of heat transfer enhancement in phase change energy storage units. The experiments are performed using spherical capsules filled with paraffin wax and metal beads. The experiments are conducted by inserting a single spherical capsule filled with wax and metal beads in a stream of hot/cold air. Experimental measurements include the temperature field within the spherical capsule and in the air stream. To determine the enhancement effects of the metal beads, the measured data is correlated against those for a spherical capsule filled with pure wax. Data analysis shows a reduction of 15% in the melting and solidification times upon increasing the number and diameter of the metal beads. This reduction is caused by a similar decrease in the thermal load of the sphere due to replacement of the wax by metal beads. The small size of the spherical capsule limits the enhancement effects; this is evident upon comparison of the heat transfer in a larger size, double pipe energy storage unit, where 2% of the wax volume is replaced with metal inserts, result in a three fold reduction in the melting/solidification time and a similar enhancement in the heat transfer rate. (author)

  1. Energetic materials destruction using molten salt

    Energy Technology Data Exchange (ETDEWEB)

    Upadhye, R.S.; Watkins, B.E.; Pruneda, C.O.; Brummond, W.A.

    1994-04-29

    The Lawrence Livermore National Laboratory in conjunction with the Energetic Materials Center is developing methods for the safe and environmentally sound destruction of explosives and propellants as a part of the Laboratory`s ancillary demilitarization mission. LLNL has built a small-scale unit to test the destruction of HE using the Molten Salt Destruction (MSD) Process. In addition to the high explosive HMX, destruction has been carried out on RDX, PETN, ammonium picrate, TNT, nitroguanadine, and TATB. Also destroyed was a liquid gun propellant comprising hydroxyammonium nitrate, triethanolammonium nitrate and water. In addition to these pure components, destruction has been carried out on a number of commonly used formulations, such as LX-10, LX-16, LX-17, and PBX-9404.

  2. Molten fluorides for nuclear applications

    Directory of Open Access Journals (Sweden)

    Sylvie. Delpech

    2010-12-01

    Full Text Available The importance of pyrochemistry is being increasingly acknowledged and becomes unavoidable in the nuclear field. Molten salts may be used for fuel processing and spent fuel recycling, for heat transfer, as a homogeneous fuel and as a breeder material in fusion systems. Fluorides that are stable at high temperature and under high neutron flux are especially promising. Analysis of several field cases reveals that corrosion in molten fluorides is essentially due to the oxidation of metals by uranium fluoride and/or oxidizing impurities. The thermodynamics of this process are discussed with an emphasis on understanding the mass transfer in the systems, selecting appropriate metallic materials and designing effective purification methods.

  3. Conduit for high temperature transfer of molten semiconductor crystalline material

    Science.gov (United States)

    Fiegl, George (Inventor); Torbet, Walter (Inventor)

    1983-01-01

    A conduit for high temperature transfer of molten semiconductor crystalline material consists of a composite structure incorporating a quartz transfer tube as the innermost member, with an outer thermally insulating layer designed to serve the dual purposes of minimizing heat losses from the quartz tube and maintaining mechanical strength and rigidity of the conduit at the elevated temperatures encountered. The composite structure ensures that the molten semiconductor material only comes in contact with a material (quartz) with which it is compatible, while the outer layer structure reinforces the quartz tube, which becomes somewhat soft at molten semiconductor temperatures. To further aid in preventing cooling of the molten semiconductor, a distributed, electric resistance heater is in contact with the surface of the quartz tube over most of its length. The quartz tube has short end portions which extend through the surface of the semiconductor melt and which are lef bare of the thermal insulation. The heater is designed to provide an increased heat input per unit area in the region adjacent these end portions.

  4. Molten carbonate fuel cell matrices

    Science.gov (United States)

    Vogel, Wolfgang M.; Smith, Stanley W.

    1985-04-16

    A molten carbonate fuel cell including a cathode electrode of electrically conducting or semiconducting lanthanum containing material and an electrolyte containing matrix of an electrically insulating lanthanum perovskite. In addition, in an embodiment where the cathode electrode is LaMnO.sub.3, the matrix may include LaAlO.sub.3 or a lithium containing material such as LiAlO.sub.2 or Li.sub.2 TiO.sub.3.

  5. Coatings and films derived from clay/wax nanocomposites

    Science.gov (United States)

    Chaiko, David J.; Leyva, Argentina A.

    2006-11-14

    The invention provides methods for making clay/wax nanocomposites and coatings and films of same with improved chemical resistance and gas barrier properties. The invention further provides methods for making and using emulsions of such clay/wax nanocomposites. Typically, an organophillic clay is combined with a wax or wax/polymer blend such that the cohesion energy of the clay matches that of the wax or wax/polymer blend. Suitable organophilic clays include mica and phyllosilicates that have been surface-treated with edge or edge and surface modifying agents. The resulting nanocomposites have applications as industrial coatings and in protective packaging.

  6. Processing method for molten salt waste

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Shuichi; Sawa, Toshio; Hoshikawa, Tadahiro; Suzuoki, Akira

    1999-01-06

    The present invention concerns a processing method for selectively adsorbing and removing radioactive metal ingredients contained in high temperature molten salts by an inorganic ion exchanger and separating radioactive metal ingredients from the molten salts as high level radioactive wastes upon reprocessing of spent nuclear fuels by using molten salts. The molten salts occluded in the inorganic ion exchanger are desorbed with highly purified water. Successively, saturation adsorbed radioactive metal ingredients are desorbed by an aqueous solution of alkali metal salt or an aqueous solution of alkaline earth metal salt. The desorbed molten salts and radioactive metal ingredients are formed into at least two kinds of radioactive waste solidification materials depending on each of radioactivity level. As the inorganic ion exchanger, at least one of aluminosilicate and hydroxides is used. Then, molten salt wastes generated upon a dry-type reprocessing can be processed as a stable borosilicate glass solidification material or as a similar homogeneous solid material. (T.M.)

  7. Electrochemistry and Electrochemical Methodology in Molten Salts.

    Science.gov (United States)

    1980-09-01

    similar conditions. A manuscript based on this work has been published in the Journal of the Electrochemical Society (34). 2) Melt and co-solvent As...Temperature Molten Salt," In "Proceedings of the 2nd International Symposium on Molten Salts," 3. Braunstein, Ed., published by The Electrochemical Society , in...Jones and L. G. Boxall, "Electrochemical Studies in Molten Chloroaluminates," Symposium on Fused Salt Tech- nology, Electrochemical Society Meeting

  8. The Possibility of Wax Formation in Gas Fields: a Case Study

    Institute of Scientific and Technical Information of China (English)

    Z.Jeirani; A.Lashanizadegan; Sh.Ayatollahi; J.Javanmardi

    2007-01-01

    Natural gas production from a gas reservoir (Reservoir A) located in the south of Iran,presents solids deposition during processing because the condensate contains suspended and dissolved solids.Solids deposition occurs not only in the transportation lines from the wells to the separators but also in the various operating units of gas streams and condensate stream.In this study,the multisolid-phase model has been used to predict the wax precipitation from gas and gas condensate fluids.The properties of gas and liquid phases are described using the Soave-Redlich-Kwong (SRK) equation of state.The model is then used to predict the possibility of the wax formation in Reservoir A gas facilities,located at the south of Iran.Solid deposition which occurred in the various streams of that facility confirmed the calculated results.Finally,the wax appearance temperature(WAT),the weight percent of wax formation and the effects of pressure and temperature on the wax formation were also predicted.

  9. Microencapsulation of Flavors in Carnauba Wax

    Directory of Open Access Journals (Sweden)

    Branko Bugarski

    2010-01-01

    Full Text Available The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM, while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at around 200 °C, while matrix degradation starts at 250 °C and progresses with maxima at around 360, 440 and 520 °C. The results indicate that carnauba wax is an attractive material for use as a matrix for encapsulation of flavours in order to improve their functionality and stability in products.

  10. The Thermodielectric Effect in Paraffin Wax

    Science.gov (United States)

    Tomas, Martin; Novotny, Pavel

    2015-02-01

    This paper deals with results of the thermodielectric effect measurement. A paraffin wax as a dielectric material was investigated via differential scanning calorimetry and potentiometry during a phase transition. Possible description of the thermodielectric effect based on fundamental laws of thermodynamics is shown; to be more specific, the link between the potential difference and the latent heat is presented. The thermodynamic model of thermodielectric effect based on electrochemical equilibrium and charge generation at the solid/liquid interface is introduced. Results of the thermodielectric effect measurement are used for the calculation of a molecular mass of the paraffin wax. The relation for a surface area (interface) between liquid and solid phase of the paraffin wax during solidification is derived from the presented theoretical description of the thermodielectric effect.

  11. Numerical tools for Molten salt reactor simulation

    Energy Technology Data Exchange (ETDEWEB)

    Doligez, X.; Heuer, D.; Merle-Lucotte, E.; Allibert, M.; Ghetta, V. [LPSC-IN2P3-CNRS/Universite Joseph Fourier/Grenoble-INP, 53 Avenue des Martyrs, 38026 Grenoble Cedex (France)

    2009-06-15

    Molten salt reactors (MSR) are basically different from other reactors mainly because the fuel is liquid. It flows through the core, pipes, pumps and heat exchangers. Previous studies showed that a particular configuration of a molten salt reactor perfectly fulfils criteria chosen by the Generation 4 International Forum (GIF). This configuration, called non-moderated Thorium Molten Salt Reactor is a 1000 GW electrical thorium cycle based molten salt reactor with no moderator inside the core. Consequently, the neutron spectrum is fast. The reactor is coupled with a salt control unit, which complicates the studies. Reactors simulation is based on resolving Bateman's equations, which give the population of each nucleus inside the core at each moment. Because of MSR's fundamental characteristics, those equations have to be modified adding two terms: a fertile/fissile alimentation for the reactivity and the salt composition control, and the reprocessing associated term. Equations become: {delta}N{sub i}/{delta}t = {sigma}{sub j{ne}}{sub i} {lambda}{sub j{yields}}{sub i} N{sub j} + X{sub j} <{sigma}{sub j}{phi}> N{sub j} - {lambda}{sub i}N{sub i} - <{sigma}{sub i}{phi}> N{sub i} {lambda}{sub chem} N{sub i} + A where {lambda}{sub chem} represents the reprocessing capacities and A represents the fertile/fissile alimentation. All our studies are made with a homemade code, REM, which is a precision driven code for material evolution. Neutron flux and neutron reactions rate are calculated thanks MCNP and the temporal integration is made thanks a Runge-Kutta fourth order method. This code REM, whose calculation scheme will be described in the paper, does not allow a coupling flexible enough between the reprocessing and the core physics. Indeed, reprocessing terms in the previous equation ({lambda}{sub chem}) are set for the whole evolution that can last several hundreds of years. A new way is to drive chemical needs to keep the core critical. Therefore, we are

  12. The molten glass sewing machine

    Science.gov (United States)

    Brun, P.-T.; Inamura, Chikara; Lizardo, Daniel; Franchin, Giorgia; Stern, Michael; Houk, Peter; Oxman, Neri

    2017-04-01

    We present a fluid-instability-based approach for digitally fabricating geometrically complex uniformly sized structures in molten glass. Formed by mathematically defined and physically characterized instability patterns, such structures are produced via the additive manufacturing of optically transparent glass, and result from the coiling of an extruded glass thread. We propose a minimal geometrical model-and a methodology-to reliably control the morphology of patterns, so that these building blocks can be assembled into larger structures with tailored functionally and optically tunable properties. This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications'.

  13. Morphology and networks of sunflower wax crystals in organogel

    Science.gov (United States)

    Plant waxes are considered as promising alternatives to unhealthy solid fats such as trans fats and saturated fats in structured food products including margarines and spreads. Sunflower wax is of a great interest due to its strong gelling ability. Morphology of sunflower wax crystals formed in soyb...

  14. The composition of wax and oil in green coffee beans

    NARCIS (Netherlands)

    Folstar, P.

    1976-01-01

    Methods for the isolation of wax and oil from green coffee beans were studied and a method for the quantitative extraction of coffee oil from the beans was introduced. Coffee wax, coffee oil and wax-free coffee oil as well as the unsaponifiable matter prepared from each were fractionated by column c

  15. The composition of wax and oil in green coffee beans

    NARCIS (Netherlands)

    Folstar, P.

    1976-01-01

    Methods for the isolation of wax and oil from green coffee beans were studied and a method for the quantitative extraction of coffee oil from the beans was introduced. Coffee wax, coffee oil and wax-free coffee oil as well as the unsaponifiable matter prepared from each were fractionated by column c

  16. Mechanism of removing inclusions from molten aluminum by stirring active molten flux

    Institute of Scientific and Technical Information of China (English)

    周鸣; 李克; 孙宝德; 疏达; 倪红军; 王俊; 张佼

    2003-01-01

    Removal of inclusions from industrial pure molten aluminum(A01) by stirring active molten flux wasstudied. Wettability of nonmetallic inclusions in the molten aluminum was worse than that in active molten flux. Ac-cording to the surface renewal model, the inclusions were easily transferred into molten active flux from fine alumi-num droplets and then reacted chemically when molten aluminum was dispersed into fine aluminum droplets in stir-ring active molten flux. Tensile tests show that tensile strength of purified tensile sample(as-cast) increases by8.59%. SEM photographs show that the fracture cracks of purified tensile sample are homogeneous, and the dim-ples are small and homogeneous. From metallographs and statistic results of Leco analysis software, it is found thatthe quantities and sizes of the inclusions in purified sample are obviously fewer and smaller than in unpurified tensilesample(as-cast).

  17. Metal Production by Molten Salt Electrolysis

    DEFF Research Database (Denmark)

    Grjotheim, K.; Kvande, H.; Qingfeng, Li

    Chemistry and electrochemistry of molten salts are reviewed. Technological aspects of electrolytic production of aluminium, magnesium, and other metals are comprehensively surveyed.......Chemistry and electrochemistry of molten salts are reviewed. Technological aspects of electrolytic production of aluminium, magnesium, and other metals are comprehensively surveyed....

  18. Metal Production by Molten Salt Electrolysis

    DEFF Research Database (Denmark)

    Grjotheim, K.; Kvande, H.; Qingfeng, Li

    Chemistry and electrochemistry of molten salts are reviewed. Technological aspects of electrolytic production of aluminium, magnesium, and other metals are comprehensively surveyed.......Chemistry and electrochemistry of molten salts are reviewed. Technological aspects of electrolytic production of aluminium, magnesium, and other metals are comprehensively surveyed....

  19. Experimental wax mixtures for dental use.

    Science.gov (United States)

    Kotsiomiti, E; McCabe, J F

    1997-07-01

    Improvements in the properties of dental waxes were sought by alterations in their composition. Twenty-six blends of paraffin wax, beeswax and inorganic filler were subjected to the following tests: plastic deformation (flow), linear thermal expansion, elastic modulus and flexural strength. Flow tests were conducted in accordance with the corresponding ISO specification. Thermal expansion coefficients were estimated using thermomechanical analysis. Mechanical properties were tested using a universal testing machine. Pure paraffin and beeswax were used as controls. The results were subjected to analysis using correlation and regression. Regression coefficients in the range of 0.90-0.99 were obtained in most cases, flow tests exhibiting the highest coefficients and flexural strength the lowest. The incorporated filler particles reduced the flow of the natural waxes, especially of the ester-containing beeswax, and improved the elastic modulus and strength. Good correlation was found between the ingredient proportions and measured properties, suggesting a relationship between them, although this is quite complicated in the case of tertiary wax mixtures. The experimental blends exhibited properties that are potentially useful for a range of clinical applications.

  20. 21 CFR 184.1976 - Candelilla wax.

    Science.gov (United States)

    2010-04-01

    ... wax is prepared by immersing the plants in boiling water containing sulfuric acid and skimming off the... recognized as safe (GRAS) as a direct human food ingredient is based upon the following current good... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

  1. Epicuticular waxes and glaucousness of Encephalartos leaves

    NARCIS (Netherlands)

    Osborne, R; Stevens, JF

    1996-01-01

    The epicuticular leaf waxes from four glaucous and four non-glaucous species of Encephalartos were examined by GC-mass spectrometry and SEM techniques. The four glaucous-leaved species, E. horridus, E. lehmannii, E. princeps and E. trispinosus, all occurring in xeric conditions in the Eastern Cape P

  2. EPICUTICULAR WAXES OF SEDUM SERIES RUPESTRIA

    NARCIS (Netherlands)

    STEVENS, JF; HART, HT; POUW, AJA; BOLCK, A; ZWAVING, JH

    1994-01-01

    Epicuticular waxes from 55 plants of the seven species of Sedum series Rupestria and four artificial hybrids have been examined by GC and GC-MS. The taxa were S. amplexicaule, S. forsterianum, S. montanum ssp. montanum, S. montanum ssp. orientale, S. ochroleucum, S. pruinatum, S. rupestre ssp. erect

  3. EPICUTICULAR WAXES OF SEDUM SERIES RUPESTRIA

    NARCIS (Netherlands)

    STEVENS, JF; HART, HT; POUW, AJA; BOLCK, A; ZWAVING, JH

    1994-01-01

    Epicuticular waxes from 55 plants of the seven species of Sedum series Rupestria and four artificial hybrids have been examined by GC and GC-MS. The taxa were S. amplexicaule, S. forsterianum, S. montanum ssp. montanum, S. montanum ssp. orientale, S. ochroleucum, S. pruinatum, S. rupestre ssp. erect

  4. Severe complications of a "Brazilian" bikini wax.

    Science.gov (United States)

    Dendle, Claire; Mulvey, Sheila; Pyrlis, Felicity; Grayson, M Lindsay; Johnson, Paul D R

    2007-08-01

    A 20-year-old Australian woman with poorly controlled type 1 diabetes presented with life-threatening Streptococcus pyogenes and Herpes simplex infection of her external genitalia following a routine perineal "Brazilian" bikini wax. Extensive pubic hair removal is now common among young adults in Australia and elsewhere. However, the infectious risks of these practices, particularly among immunosuppressed individuals, are often underappreciated.

  5. Purification technology of molten aluminum

    Institute of Scientific and Technical Information of China (English)

    孙宝德; 丁文江; 疏达; 周尧和

    2004-01-01

    Various purification methods were explored to eliminate the dissolved hydrogen and nonmetallic inclusions from molten aluminum alloys. A novel rotating impeller head with self-oscillation nozzles or an electromagnetic valve in the gas circuit was used to produce pulse gas currents for the rotary impeller degassing method. Water simulation results show that the size of gas bubbles can be decreased by 10%-20% as compared with the constant gas current mode. By coating ceramic filters or particles with active flux or enamels, composite filters were used to filter the scrap A356 alloy and pure aluminum. Experimental results demonstrate that better filtration efficiency and operation performance can be obtained. Based on numerical calculations, the separation efficiency of inclusions by high frequency magnetic field can be significantly improved by using a hollow cylinder-like separator or utilizing the effects of secondary flow of the melt in a square separator. A multi-stage and multi-media purification platform based on these methods was designed and applied in on-line processing of molten aluminum alloys. Mechanical properties of the processed scrap A356 alloy are greatly improved by the composite purification.

  6. Renewable energy and the role of molten salts and carbon

    Directory of Open Access Journals (Sweden)

    Fray D.

    2013-01-01

    Full Text Available Molten carbonate fuel cells have been under development for a number of years and reliable units are successfully working at 250kW scale and demonstration units have produced up to 2 MW. Although these cells cannot be considered as renewable as the fuel, hydrogen or carbon monoxide is consumed and not regenerated, the excellent reliability of such a cell can act as a stimulus to innovative development of similar cells with different outcomes. Molten salt electrolytes based upon LiCl - Li2O can be used to convert carbon dioxide, either drawn from the output of a conventional thermal power station or from the atmosphere, to carbon monoxide or carbon. Recently, dimensionally stable anodes have been developed for molten salt electrolytes, based upon alkali or alkaline ruthenates which are highly electronically conducting and these may allow the concept of high temperature batteries to be developed in which an alkali or alkaline earth element reacts with air to form oxides when the battery is discharging and the oxide decomposes when the battery is being recharged. Batteries using these concepts may be based upon the Hall-Heroult cell, which is used worldwide for the production of aluminium on an industrial scale, and could be used for load levelling. Lithium ion batteries are, at present, the preferred energy source for cars in 2050 as there are sufficient lithium reserves to satisfy the world’s energy needs for this particular application. Graphite is used in lithium ion batteries as the anode but the capacity is relatively low. Silicon and tin have much higher capacities and the use of these materials, encapsulated in carbon nanotubes and nanoparticles will be described. This paper will review these interesting developments and demonstrate that a combination of carbon and molten salts can offer novel ways of storing energy and converting carbon dioxide into useful products.

  7. Real-Time monitoring of intracellular wax ester metabolism

    Directory of Open Access Journals (Sweden)

    Karp Matti

    2011-09-01

    Full Text Available Abstract Background Wax esters are industrially relevant molecules exploited in several applications of oleochemistry and food industry. At the moment, the production processes mostly rely on chemical synthesis from rather expensive starting materials, and therefore solutions are sought from biotechnology. Bacterial wax esters are attractive alternatives, and especially the wax ester metabolism of Acinetobacter sp. has been extensively studied. However, the lack of suitable tools for rapid and simple monitoring of wax ester metabolism in vivo has partly restricted the screening and analyses of potential hosts and optimal conditions. Results Based on sensitive and specific detection of intracellular long-chain aldehydes, specific intermediates of wax ester synthesis, bacterial luciferase (LuxAB was exploited in studying the wax ester metabolism in Acinetobacter baylyi ADP1. Luminescence was detected in the cultivation of the strain producing wax esters, and the changes in signal levels could be linked to corresponding cell growth and wax ester synthesis phases. Conclusions The monitoring system showed correlation between wax ester synthesis pattern and luminescent signal. The system shows potential for real-time screening purposes and studies on bacterial wax esters, revealing new aspects to dynamics and role of wax ester metabolism in bacteria.

  8. Analysis of wax burn cases presenting to an Emergency Department in Hong Kong during the Chinese Mid-Autumn festival.

    Science.gov (United States)

    Tam, Michael Man-kit; Cheung, Wai lun

    2003-06-01

    Records of patients presenting to the Emergency Department (ED) of the Prince of Wales Hospital with wax burns during Mid-Autumn festival from 1998 to 2001 were retrieved and analyzed. There were 26 patients in total (21 males, 5 females). Annual attendances from 1998 to 2001 were 11, 7, 4 and 4, respectively. Age ranged from 1 to 33 years (median age: 11.5). Most patients were injured by molten wax (n=23, 88.5%), the rest were burnt by flame (n=3, 11.5%). Partial thickness burn (superficial and deep) was the most common (n=23, 88.4%). Superficial burn accounted for the rest (n=3, 11.5%). No patient had full thickness burn. All patients had <5% of body surface area (BSA) burnt, with the majority only involving <1% BSA (n=16, 61.5%). The commonest sites of injury were the lower limbs (n=15, 57.7%), the upper limbs (n=8, 30.8%) and face (n=7, 26.9%). Three patients (11.5%) had multiple sites burnt. Only eight patients (30.8%) required burns surgeon's consultation, out of which seven (26.9%) required in-patient treatment. Most burns caused by or related to boiling wax were minor. The declining incidence is the combined result of legislation, product modification, education and publicity.

  9. Thermal conductivity of molten metals

    Energy Technology Data Exchange (ETDEWEB)

    Peralta-Martinez, Maria Vita

    2000-02-01

    A new instrument for the measurement of the thermal conductivity of molten metals has been designed, built and commissioned. The apparatus is based on the transient hot-wire technique and it is intended for operation over a wide range of temperatures, from ambient up to 1200 K, with an accuracy approaching 2%. In its present form the instrument operates up to 750 K. The construction of the apparatus involved four different stages, first, the design and construction of the sensor and second, the construction of an electronic system for the measurement and storage of data. The third stage was the design and instrumentation of the high temperature furnace for the melting and temperature control of the sample, and finally, an algorithm was developed for the extraction of the thermal conductivity from the raw measurement data. The sensor consists of a cylindrical platinum-wire symmetrically sandwiched between two rectangular plane sheets of alumina. The rectangular sensor is immersed in the molten metal of interest and a voltage step is applied to the ends of the platinum wire to induce heat dissipation and a consequent temperature rise which, is in part, determined by the thermal conductivity of the molten metal. The process is described by a set of partial differential equations and appropriate boundary conditions rather than an approximate analytical solution. An electronic bridge configuration was designed and constructed to perform the measurement of the resistance change of the platinum wire in the time range 20 {mu}s to 1 s. The resistance change is converted to temperature change by a suitable calibration. From these temperature measurements as a function of time the thermal conductivity of the molten metals has been deduced using the Finite Element Method for the solution of the working equations. This work has achieved its objective of improving the accuracy of the measurement of the thermal conductivity of molten metals from {+-}20% to {+-}2%. Measurements

  10. Corrosion of metals in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Vossen, J.P.T.

    1991-05-15

    Part 1 of this report describes the results of a literature study on the corrosion behavior of metals in molten carbonates. The results form the basis for a doctorate study related to improving the durability of metal separator plates for molten carbonate fuel cells. To gain a better understanding also the literature on corrosion in molten sulfates has been reviewed, the results of which are summarized in Part 2 of this report. For each part a separate abstract has been prepared. 83 figs., 23 tabs., 1 app., 78 refs.

  11. Stability of dental waxes following repeated heatings.

    Science.gov (United States)

    Kotsiomiti, E; McCabe, J F

    1995-02-01

    The flow and strength properties of dental waxes were examined following excessive and repeated heatings of the materials. For one product, the flow at 40 +/- 0.5 degrees C was reduced by 25.3% following heating above 200 degrees C. A decrease of the elastic modulus at 20 +/- 1 degree C by approximately 66% was observed in some cases after the heating temperature had been increased to 300 degrees C. Property variations were related to compositional changes, which were investigated by infrared spectoscopy and thermal analysis. Exposure of dental waxes to temperatures higher than 200 degrees C, particularly if it is repeated, may affect the composition and properties, resulting in inferior materials.

  12. Lacustrine biomass: An significant precursor of high wax oil

    Institute of Scientific and Technical Information of China (English)

    HUANG Haiping; ZHENG Yabin; ZHANG Zhanwen; LI Jinyou

    2003-01-01

    Although a variety of precursors have been proposed for the formation of high molecular weight hydrocarbons (HMWHCs) in crude oil, their precise origin remains elusive. Quantitative studies of macrocrystalline wax and microcrystalline wax content of source rock extracts from the Damintun depression, Liaohe Basin, a typical high wax producing area, coupled with microscopical maceral composition studies and pyrolysis-GC analysis indicate that oil shale enriched in lacustrine biomass makes a primary contribution to wax in oil. The main precursors of high wax oil are lacustrine alginites and their amorphous matrix, which are highly aliphatic in nature and have high generative potential for HMWHCs. Wax generation efficiency could be affected by organic material abundance and maturity. The high abundance and low maturity of organic material are favorite for the formation of high quantity of wax, which declines with decreasing organic abundance and increasing thermal maturity. This suggests that wax is derived from organic-rich lacustrine biomass at early stages of maturation (RO = 0.4%-0.7%). Although the contribution of high plant cuticular wax and sporopollen cannot be ruled out, lacustrine biomass is more important in the formation of high wax oil.

  13. Sintering of wax for controlling release from pellets.

    Science.gov (United States)

    Singh, Reena; Poddar, S S; Chivate, Amit

    2007-09-14

    The purpose of the present study was to investigate incorporation of hydrophobic (ie, waxy) material into pellets using a thermal sintering technique and to evaluate the pellets in vitro for controlled release. Pellets prepared by extrusion-spheronization technology were formulated with a water-soluble drug, microcrystalline cellulose, and carnauba wax. Powdered carnauba wax (4%-20%) prepared by grinding or by emulsification was studied with an attempt to retard the drug release. The inclusion of ground or emulsified carnauba wax did not sustain the release of theophylline for more than 3 hours. Matrix pellets of theophylline prepared with various concentrations of carnauba wax were sintered thermally at various times and temperatures. In vitro drug release profiles indicated an increase in drug release retardation with increasing carnauba wax concentration. Pellets prepared with ground wax showed a higher standard deviation than did those prepared with emulsified wax. There was incomplete release at the end of 12 hours for pellets prepared with 20% ground or emulsified wax. The sintering temperature and duration were optimized to allow for a sustained release lasting at least 12 hours. The optimized temperature and duration were found to be 100 degrees C and 140 seconds, respectively. The sintered pellets had a higher hydrophobicity than did the unsintered pellets. Scanning electron micrographs indicated that the carnauba wax moved internally, thereby increasing the surface area of wax within the pellets.

  14. Physical properties of wax deposits on the walls of crude pipelines

    Institute of Scientific and Technical Information of China (English)

    Huang Qiyu; Wang Jifeng; Zhang Jinjun

    2009-01-01

    Wax deposits on the wall of a crude oil pipeline are a solid wax network of fine crystals, filled with oil, resin, asphaitene and other impurities. In this paper, a series of experiments on wax deposition in a laboratory flow loop were performed under different conditions (flow rate, temperature differential between crude oil and pipeline wall, and dissolved wax concentration gradient), and the wax deposits were analyzed, so quantitative relationships among wax content, wax appearance temperature (WAT), shear stress, and radial concentration gradient of dissolved wax at the solid/liquid interface were obtained. Finally, a model was established to predict WAT and the wax content of the deposit.

  15. Molten salts processes and generic simulation

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Toru; Minato, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-12-01

    Development of dry separation process (pyrochemical process) using molten salts for the application of spent-nuclear fuel reprocessing requires a rather complete fundamental database as well as process simulation technique with wide applicability. The present report concerns recent progress and problems in this field taking behaviors of co-electrodeposition of UO{sub 2} and PuO{sub 2} in molten salts as an example, and using analytical simulation of local equilibrium combined with generic diffusion. (S. Ohno)

  16. Dental wax decreases calculus accumulation in small dogs.

    Science.gov (United States)

    Smith, Mark M; Smithson, Christopher W

    2014-01-01

    A dental wax was evaluated after unilateral application in 20 client-owned, mixed and purebred small dogs using a clean, split-mouth study model. All dogs had clinical signs of periodontal disease including plaque, calculus, and/or gingivitis. The wax was randomly applied to the teeth of one side of the mouth daily for 30-days while the contralateral side received no treatment. Owner parameters evaluated included compliance and a subjective assessment of ease of wax application. Gingivitis, plaque and calculus accumulation were scored at the end of the study period. Owners considered the wax easy to apply in all dogs. Compliance with no missed application days was achieved in 8 dogs. The number of missed application days had no effect on wax efficacy. There was no significant difference in gingivitis or plaque accumulation scores when comparing treated and untreated sides. Calculus accumulation scores were significantly less (22.1 %) for teeth receiving the dental wax.

  17. Natural oils and waxes: studies on stick bases.

    Science.gov (United States)

    Budai, Lívia; Antal, István; Klebovich, Imre; Budai, Marianna

    2012-01-01

    The objective of the present article was to examine the role of origin and quantity of selected natural oils and waxes in the determination of the thermal properties and hardness of stick bases. The natural oils and waxes selected for the study were sunflower, castor, jojoba, and coconut oils. The selected waxes were yellow beeswax, candelilla wax, and carnauba wax. The hardness of the formulations is a critical parameter from the aspect of their application. Hardness was characterized by the measurement of compression strength along with the softening point, the drop point, and differential scanning calorimetry (DSC). It can be concluded that coconut oil, jojoba oil, and carnauba wax have the greatest influence on the thermal parameters of stick bases.

  18. Structure of molten titanium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Alderman, O. L. G.; Skinner, L. B.; Benmore, C. J.; Tamalonis, A.; Weber, J. K. R.

    2014-09-01

    The x-ray structure factor of molten TiO2 has been measured for the first time, enabled by the use of aerodynamic levitation and laser beam heating, to a temperature of T = 2250(30) K. Ti-O coordination number in the melt is close to nTiO = 5.0(2), with modal Ti-O bond length rTiO = 1.881(5) Å, both values being significantly smaller than for the high temperature stable Rutile crystal structure (nTiO = 6.0, rTiO = 1.959 Å). The structural differences between melt and crystal are qualitatively similar to those for alumina, which is rationalized in terms of the similar field strengths of Ti4+ and Al3+. The diffraction data are used to generate physically and chemically reasonable structural models, which are then compared to the predictions based on various classical molecular dynamics (MD) potentials. New interatomic potentials, suitable for modelling molten TiO2, are introduced, given the inability of existing MD models to reproduce the diffraction data. These new potentials have the additional great advantage of being able to predict the density and thermal expansion of the melt, as well as solid amorphous TiO2, in agreement with published results. This is of critical importance given the strong correlation between density and structural parameters such as nTiO. The large thermal expansion of the melt is associated with weakly temperature dependent structural changes, whereby simulations show that nTiO = 5.85(2) – (3.0(1) x 10-4 )T (K, 2.75 Å cut-off). The TiO2 liquid is structurally analogous to the geophysically relevant high pressure liquid silica system at around 27 GPa. We argue that the predominance of 5-fold polyhedra in the melt implies the existence of as yet undiscovered TiO2 polymorphs, based on lowerthan-octahedral coordination numbers, which are likely to be metastable under ambient conditions. Given the industrial importance of titanium oxides, experimental and computational searches for such polymorphs are well warranted.

  19. Thermolysis of Kansko-Achinsk coal in a molten medium

    Energy Technology Data Exchange (ETDEWEB)

    Uzdenskiy, V.B.; Martynov, Yu.N.; Proskuryakov, V.A.

    1982-01-01

    Thermolysis of Kansko-Achinsk coal is studied in molten mediums of varying nature: metals, such as tin and lead, or salts, such as carbonates of alkaline metals. The effect of temperature, heating rate and nature of the melt on the output and composition of the decomposition products is demonstrated. The use of melts makes it possible to produce 13 to 14 percent resin per unit of coal and gas for use as a reducer or fuel. A melt of salts has an active effect on the decomposition of the organic mass of the coal.

  20. The mystery of molten metal

    Directory of Open Access Journals (Sweden)

    Natalia Sobczak

    2010-11-01

    Full Text Available Recent advances in scientific understanding of high-temperature materials processing using novel experimental methodologies have shed light on the complex role of surface and interface phenomena. New in-situ studies on molten metal/solid ceramic interactions using a unique experimental complex at the Foundry Research Institute, Krakow, have revealed a number of unusual observations in materials processing at high temperatures. We present some such unusual observations and their explanation with reference to liquid metal processing of Al, Ni, and Ti, and their alloys in contact with oxide ceramics. In particular, we focus on the following aspects: primary oxidation of Al from residual water vapor or oxygen, capillary purification to remove surface oxide, substrate protection by CVD carbon, roughening due to spinel whisker formation, inclusions in castings due to mechanical detachment, floatation due to buoyancy forces, and segregation due to directional solidification, modification of the solid surface morphology by metal vapor ahead of the liquid, and the complication due to multi-component alloys melted in crucibles made from complex oxide-based ceramics. In the case of Ti, rapid reactions with oxides result in undesirable volumetric changes that create difficulty in casting high-quality Ti parts, particularly by investment casting. Nanoscale (e.g., colloidal coatings based on Y2O3 protect crucibles and hold ladles against such attack. Practical insights and recommendations for materials processing emerging from the fundamental studies on high-temperature interfacial phenomena have been described.

  1. Absorption and distribution of orally administered jojoba wax in mice.

    Science.gov (United States)

    Yaron, A; Samoiloff, V; Benzioni, A

    1982-03-01

    The liquid wax obtained from the seeds of the arid-land shrub jojoba (Simmondsia chinensis) is finding increasing use in skin treatment preparations. The fate of this wax upon reaching the digestive tract was studied. 14C-Labeled wax was administered intragastrically to mice, and the distribution of the label in the body was determined as a function of time. Most of the wax was excreted, but a small amount was absorbed, as was indicated by the distribution of label in the internal organs and the epididymal fat. The label was incorporated into the body lipids and was found to diminish with time.

  2. Effect of solvent extraction on Tunisian esparto wax composition

    Directory of Open Access Journals (Sweden)

    Saâd Inès

    2016-08-01

    Full Text Available The increase of needs for renewable and vegetable based materials will help to drive the market growth of vegetable waxes. Because of their highly variable composition and physicochemical properties, plant waxes have found numerous applications in the: food, cosmetic, candle, coating, polish etc... The aim of this project is to determine the effect of solvent extraction (petroleum ether and ethanol on Tunisian esparto wax composition. The GC-MS was applied in order to determine the waxes compositions. Then, physicochemical parameters of these two samples of waxes: acid value, saponification value, iodine value and melting point were measured in order to deduct their properties and possible fields of uses. Results showed that esparto wax composition depended on the solvent extraction and that major components of the two samples of waxes were: alkanes, esters of fatty acids and phenols. Furthermore, esparto waxes were characterized by an antioxidant and antibacterial activities but the potential of these activities depended on the solvent of wax extraction.

  3. Wax Ester Fermentation and Its Application for Biofuel Production.

    Science.gov (United States)

    Inui, Hiroshi; Ishikawa, Takahiro; Tamoi, Masahiro

    2017-01-01

    In Euglena cells under anaerobic conditions, paramylon, the storage polysaccharide, is promptly degraded and converted to wax esters. The wax esters synthesized are composed of saturated fatty acids and alcohols with chain lengths of 10-18, and the major constituents are myristic acid and myristyl alcohol. Since the anaerobic cells gain ATP through the conversion of paramylon to wax esters, the phenomenon is named "wax ester fermentation". The wax ester fermentation is quite unique in that the end products, i.e. wax esters, have relatively high molecular weights, are insoluble in water, and accumulate in the cells, in contrast to the common fermentation end products such as lactic acid and ethanol.A unique metabolic pathway involved in the wax ester fermentation is the mitochondrial fatty acid synthetic system. In this system, fatty acid are synthesized by the reversal of β-oxidation with an exception that trans-2-enoyl-CoA reductase functions instead of acyl-CoA dehydrogenase. Therefore, acetyl-CoA is directly used as a C2 donor in this fatty acid synthesis, and the conversion of acetyl-CoA to malonyl-CoA, which requires ATP, is not necessary. Consequently, the mitochondrial fatty acid synthetic system makes possible the net gain of ATP through the synthesis of wax esters from paramylon. In addition, acetyl-CoA is provided in the anaerobic cells from pyruvate by the action of a unique enzyme, oxygen sensitive pyruvate:NADP(+) oxidoreductase, instead of the common pyruvate dehydrogenase multienzyme complex.Wax esters produced by anaerobic Euglena are promising biofuels because myristic acid (C14:0) in contrast to other algal produced fatty acids, such as palmitic acid (C16:0) and stearic acid (C18:0), has a low freezing point making it suitable as a drop-in jet fuel. To improve wax ester production, the molecular mechanisms by which wax ester fermentation is regulated in response to aerobic and anaerobic conditions have been gradually elucidated by identifying

  4. Effect of asphaltenes on crude oil wax crystallization

    DEFF Research Database (Denmark)

    Kriz, Pavel; Andersen, Simon Ivar

    2005-01-01

    The paper summarizes the experimental work done on asphaltene influenced wax crystallization. Three different asphaltenes (from stable oil, instable oil, and deposit) were mixed at several concentrations or dispersions into the waxy crude oil. These blends were evaluated by viscometry and yield...... stress measurement and compared with the original crude oil. A complex asphaltene−wax interaction as a function of asphaltene concentration and degree of asphaltene dispersion under dynamic and static condition was observed. The crystallization and the wax network strength was strongly dependent...... influence the wax crystallization at static condition more significantly than the more flocculated....

  5. Effect of asphaltenes on crude oil wax crystallization

    DEFF Research Database (Denmark)

    Kriz, Pavel; Andersen, Simon Ivar

    2005-01-01

    The paper summarizes the experimental work done on asphaltene influenced wax crystallization. Three different asphaltenes (from stable oil, instable oil, and deposit) were mixed at several concentrations or dispersions into the waxy crude oil. These blends were evaluated by viscometry and yield...... stress measurement and compared with the original crude oil. A complex asphaltene−wax interaction as a function of asphaltene concentration and degree of asphaltene dispersion under dynamic and static condition was observed. The crystallization and the wax network strength was strongly dependent...... influence the wax crystallization at static condition more significantly than the more flocculated....

  6. Antioxidant properties of wax from Yugoslavian oakmoss (Evernia prunastri).

    Science.gov (United States)

    Racine, P; Hartmann, V E; D'Audiffret, Y T

    1980-12-01

    Synopsis Wax from Yugoslavian oakmoss resulting from the industrial benzene extraction of the vegetable matter was extracted by solvents of different polarities. The wax and the extracts were tested for antioxidant activities using (+) limonene as peroxidizable test substrate and were found to have such activity. The extracts are more active than the wax itself. Although not directly usable because of still too low activity, the wax and the extracts contain a small amount of substance with antioxidant activity comparable to that of the usual synthetic antioxidants.

  7. The importance of being Florentine: a journey around the world for wax anatomical Venuses.

    Science.gov (United States)

    de Ceglia, Francesco Paolo

    2011-01-01

    This article reconstructs the 19th century history of events regarding a few female wax anatomical models made in Florence. More or less faithful copies of those housed in Florence's Museum of Physics and Natural History, these models were destined for display in temporary exhibitions. In their travels through Europe and the United States, they transformed the expression "Florentine Venus" into a sort of brand name used to label and offer respectability to pieces of widely varying quality.

  8. Recent advances in the molten salt destruction of energetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Pruneda, C. O., LLNL

    1996-09-01

    We have demonstrated the use of the Molten Salt Destruction (MSD) Process for destroying explosives, liquid gun propellant, and explosives-contaminated materials on a 1.5 kg of explosive/hr bench- scale unit (1, 2, 3, 4, 5). In our recently constructed 5 kg/hr pilot- scale unit we have also demonstrated the destruction of a liquid gun propellant and simulated wastes containing HMX (octogen). MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen, and water. Any inorganic constituents of the waste, such as metallic particles, are retained in the molten salt. The destruction of energetic materials waste is accomplished by introducing it, together with air, into a vessel containing molten salt (a eutectic mixture of sodium, potassium, and lithium carbonates). The following pure explosives have been destroyed in our bench-scale experimental unit located at Lawrence Livermore National Laboratory`s (LLNL) High Explosives Applications Facility (HEAF): ammonium picrate, HMX, K- 6 (keto-RDX), NQ, NTO, PETN, RDX, TATB, and TNT. In addition, the following compositions were also destroyed: Comp B, LX- IO, LX- 1 6, LX- 17, PBX-9404, and XM46 (liquid gun propellant). In this 1.5 kg/hr bench-scale unit, the fractions of carbon converted to CO and of chemically bound nitrogen converted to NO{sub x} were found to be well below 1%. In addition to destroying explosive powders and compositions we have also destroyed materials that are typical of residues which result from explosives operations. These include shavings from machined pressed parts of plastic-bonded explosives and sump waste containing both explosives and non-explosive debris. Based on the process data obtained on the bench-scale unit we designed and constructed a next-generation 5 kg/hr pilot-scale unit, incorporating LLNL`s advanced chimney design. The pilot unit has completed process implementation operations and explosives safety reviews. To date, in this

  9. Migration of mineral hydrocarbons into foods. 4. Waxed paper for packaging dry goods including bread, confectionery and for domestic use including microwave cooking.

    Science.gov (United States)

    Castle, L; Nichol, J; Gilbert, J

    1994-01-01

    Retail samples of dry goods (bread, biscuits and breakfast cereals) packaged in waxed paper were examined for the presence of mineral hydrocarbon wax. Bread loaves contained up to 50 mg/kg of the wax (associated with the outer surfaces) and crackers up to 185 mg/kg. Mineral oil was found in bread samples, at up to 550 mg/kg and was dispersed throughout indicating its use in food processing machinery as the likely source. Retail confectionery products wrapped in waxed paper (containing 12-44% w/w) gave rise to levels of 12-1300 mg/kg mineral hydrocarbon in the individually wrapped sweets. Migration into boiled sweets was lowest at 10-130 mg/kg, whilst soft chews and toffee products contained 110-1300 mg/kg. The distribution of wax hydrocarbons (principally n-alkanes) in the confectionery coincided exactly with that for the paper wrapping, with a range of C23 to C33 (95% material) centred around C26. This indicated that the transfer to the food occurred largely by adhesion rather than by diffusion since the latter would be expected to favour preferential migration of the low molecular weight components. In simulated home-use experiments with waxed bags sold in the United States for domestic use, migration into sandwiches and cake amounted to 40 mg/kg (1% transfer of wax). Use of these waxed bags in the microwave oven (as recommended) gave rise to contamination of foods from 210 to 1650 mg/kg (up to 60% transfer of wax).

  10. Physical properties of molten carbonate electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, T.; Yanagida, M.; Tanimoto, K. [Osaka National Research Institute (Japan)] [and others

    1996-12-31

    Recently many kinds of compositions of molten carbonate electrolyte have been applied to molten carbonate fuel cell in order to avoid the several problems such as corrosion of separator plate and NiO cathode dissolution. Many researchers recognize that the addition of alkaline earth (Ca, Sr, and Ba) carbonate to Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3} and Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} eutectic electrolytes is effective to avoid these problems. On the other hand, one of the corrosion products, CrO{sub 4}{sup 2-} ion is found to dissolve into electrolyte and accumulated during the long-term MCFC operations. This would affect the performance of MCFC. There, however, are little known data of physical properties of molten carbonate containing alkaline earth carbonates and CrO{sub 4}{sup 2-}. We report the measured and accumulated data for these molten carbonate of electrical conductivity and surface tension to select favorable composition of molten carbonate electrolytes.

  11. Molten salts and nuclear energy production

    Science.gov (United States)

    Le Brun, Christian

    2007-01-01

    Molten salts (fluorides or chlorides) were considered near the beginning of research into nuclear energy production. This was initially due to their advantageous physical and chemical properties: good heat transfer capacity, radiation insensitivity, high boiling point, wide range solubility for actinides. In addition it was realised that molten salts could be used in numerous situations: high temperature heat transfer, core coolants with solid fuels, liquid fuel in a molten salt reactor, solvents for spent nuclear solid fuel in the case of pyro-reprocessing and coolant and tritium production in the case of fusion. Molten salt reactors, one of the six innovative concepts chosen by the Generation IV international forum, are particularly interesting for use as either waste incinerators or thorium cycle systems. As the neutron balance in the thorium cycle is very tight, the possibility to perform online extraction of some fission product poisons from the salt is very attractive. In this article the most important questions that must be addressed to demonstrate the feasibility of molten salt reactor will be reviewed.

  12. Molten salts and nuclear energy production

    Energy Technology Data Exchange (ETDEWEB)

    Le Brun, Christian [Laboratoire de Physique Subatomique et de Cosmologie, 53 Avenue des Martyrs, 38026 Grenoble cedex (France)]. E-mail: christian.lebrun@lpsc.in2p3.fr

    2007-01-15

    Molten salts (fluorides or chlorides) were considered near the beginning of research into nuclear energy production. This was initially due to their advantageous physical and chemical properties: good heat transfer capacity, radiation insensitivity, high boiling point, wide range solubility for actinides. In addition it was realised that molten salts could be used in numerous situations: high temperature heat transfer, core coolants with solid fuels, liquid fuel in a molten salt reactor, solvents for spent nuclear solid fuel in the case of pyro-reprocessing and coolant and tritium production in the case of fusion. Molten salt reactors, one of the six innovative concepts chosen by the Generation IV international forum, are particularly interesting for use as either waste incinerators or thorium cycle systems. As the neutron balance in the thorium cycle is very tight, the possibility to perform online extraction of some fission product poisons from the salt is very attractive. In this article the most important questions that must be addressed to demonstrate the feasibility of molten salt reactor will be reviewed.

  13. Gluconeogenesis from storage wax in the cotyledons of jojoba seedlings.

    Science.gov (United States)

    Moreau, R A; Huang, A H

    1977-08-01

    The cotyledons of jojoba (Simmondsia chinensis) seeds contained 50 to 60% of their weight as intracellular wax esters. During germination there was a gradual decrease in the wax content with a concomitant rise in soluble carbohydrates, suggesting that the wax played the role of a food reserve. Thin layer chromatography revealed that both the fatty alcohol and fatty acid were metabolized. The disappearance of wax was matched with an increase of catalase, a marker enzyme of the gluconeogenic process in other fatty seedlings. Subcellular organelles were isolated by sucrose gradient centrifugation from the cotyledons at the peak stage of germination. The enzymes of the beta oxidation of fatty acid and of the glyoxylate cycle were localized in the glyoxysomes but not in the mitochondria. The glyoxysomes had specific activities of individual enzymes similar to those of the castor bean glyoxysomes. An active alkaline lipase was detected in the wax bodies at the peak stage of germination but not in the ungerminated seeds. No lipase was detected in glyoxysomes or mitochondria. After the wax in the wax bodies had been extracted with diethyl ether, the organelle membrane was isolated and it still retained the alkaline lipase. The gluconeogenesis from wax in the jojoba seedling appears to be similar, but with modification, to that from triglyceride in other fatty seedlings.

  14. Comparison of different experimental techniques used for wax deposition testing

    Energy Technology Data Exchange (ETDEWEB)

    Allenson, Stephen; Johnston, Angela [Nalco Energy Services, Sugar Land, TX (United States)

    2008-07-01

    Crude oils consist of various fractions of hydrocarbons, including n-paraffins. The paraffins precipitate out of oil below the temperature called WAT (wax appearance temperature) and accumulate in flow lines and pipelines causing major transport problems. Prediction of paraffin deposition is, therefore, a key element of flow assurance programs. The purpose of this study was to develop a general and reliable approach to prediction of wax deposition based on a critical comparison of several practical lab techniques. Wax deposition study was conducted on five separate crude oils by using a varying protocols and equipment. One experimental technique was a cold stress test of wax deposition combined with ketone precipitation of waxy paraffin crystals. Another set of experiments were carried out for wax deposits formed on the surface of U-tubes and cold fingers of different designs. A comparison of the effectiveness of several wax inhibitors was conducted for these crude oils by using the selected deposition techniques. In each test method the amount of precipitated wax was recorded and compared. The deposits were characterized by melting point, qualitative and quantitative analysis of the wax components using DSC, SARA and HTGC analyses. Efficiency of paraffin inhibitors was correlated with a profile of n-paraffins distribution in the deposits. The limitations and advantages of different deposition techniques were analyzed and discussed. (author)

  15. Physical characterization of wax/oil crystalline networks.

    Science.gov (United States)

    Martini, Silvana; Tan, Chin Yiap; Jana, Sarbojeet

    2015-05-01

    The objective of this research was to evaluate the physical properties of different types of wax/oil systems. Olive (OO), corn (CO), soybean (SBO), sunflower (SFO), safflower (SAFO), and canola (CAO) oils were mixed with sunflower oil wax (SFOW), paraffin wax (PW), and beeswax (BW) at different concentrations (1% to 10%). Results from this study show that the physical properties of wax/oil systems is affected not only by the concentration and type of wax used, but also by the type of oil used. In general, wax/oil systems formulated with SFOW generated crystalline networks with high enthalpies (1 to 22 J/g) and high G' values (2 to 6 × 10(6) Pa) compared with the values obtained for BW and PW. SFOW crystalline networks were characterized by needle-like crystals independently of the wax concentrations and type of oil used. BW crystalline networks, however, were characterized by different crystal morphologies (needle-like or spherulites) depending on the wax concentration and type of oil used. PW samples were characterized by a crystalline network formed by needle- and platelet-like crystals. Enthalpy values of BW and PW samples were similar (0.3 to 20 J/g), but BW samples resulted in significantly higher (P < 0.05) G' values in the 5% and 10% samples with values of 3.9 × 10(6) and 6.1 × 10(5) Pa for 10% BW and PW, respectively.

  16. Characterization of wax deposition by different experimental techniques - a comparison

    Energy Technology Data Exchange (ETDEWEB)

    Lindeman, Olga; Allenson, Steve

    2006-03-15

    Crude oils consist of various fractions of hydrocarbons, including n-paraffins. The paraffins precipitate out of oil below the temperature called WAT (wax appearance temperature) and accumulate in flow lines causing major transport problems. Prediction of paraffin deposition is, therefore, a key element of flow assurance programs. The purpose of this study was to develop a general and reliable approach to prediction of wax deposition based on a critical comparison of several practical lab techniques. Wax deposition study was conducted on multiple crude oils using various testing protocols and equipment. One experimental technique was a cold stress test of wax deposition combined with ketone precipitation of waxy paraffin crystals. Another set of experiments was carried out for wax deposits formed on the surface of U-tubes and cold fingers of different designs. A comparison of the effectiveness of several wax inhibitors was conducted for these crude oils by using the selected deposition techniques. In each test method the amount of precipitated wax was recorded and compared. The deposits were characterized by melting point, qualitative and quantitative analysis of the wax components using DSC, SARA and HTGC analyses. Efficiency of paraffin inhibitors was correlated with a profile of n-paraffins distribution in the deposits. The limitations and advantages of different deposition techniques were analyzed and discussed. A new test design designated ''cold tube'' is proposed. (Author) (tk)

  17. Crystal morphology of sunflower wax in soybean oil organogel

    Science.gov (United States)

    While sunflower wax has been recognized as an excellent organogelator for edible oil, the detailed morphology of sunflower wax crystals formed in an edible oil organogel has not been fully understood. In this study, polarized light microscopy, phase contrast microscopy, scanning electron microscopy ...

  18. Wax combs mediate nestmate recognition by guard honeybees

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Wenseleers, Tom; Dawson, Jenny

    2006-01-01

    Research has shown that the wax combs are important in the acquisition of colony odour in the honeybee, Apis mellifera. However, many of these studies were conducted in the laboratory or under artificial conditions. We investigated the role of the wax combs in nestmate recognition in the natural...

  19. Measuring infiltration during paraffin wax processing for histology.

    Science.gov (United States)

    Allison, R T; Lloyd, D

    1996-09-01

    A method is described to allow monitoring of the penetration of processing fluids into tissue during histological processing. The method is established by evaluating the effect of incorporating dimethyl sulphoxide into paraffin wax and comparing processing times with those for pure paraffin wax.

  20. Interspecific utilisation of wax in comb building by honeybees

    Science.gov (United States)

    Hepburn, H. Randall; Radloff, Sarah E.; Duangphakdee, Orawan; Phaincharoen, Mananya

    2009-06-01

    Beeswaxes of honeybee species share some homologous neutral lipids; but species-specific differences remain. We analysed behavioural variation for wax choice in honeybees, calculated the Euclidean distances for different beeswaxes and assessed the relationship of Euclidean distances to wax choice. We tested the beeswaxes of Apis mellifera capensis, Apis florea, Apis cerana and Apis dorsata and the plant and mineral waxes Japan, candelilla, bayberry and ozokerite as sheets placed in colonies of A. m. capensis, A. florea and A. cerana. A. m. capensis accepted the four beeswaxes but removed Japan and bayberry wax and ignored candelilla and ozokerite. A. cerana colonies accepted the wax of A. cerana, A. florea and A. dorsata but rejected or ignored that of A. m. capensis, the plant and mineral waxes. A. florea colonies accepted A. cerana, A. dorsata and A. florea wax but rejected that of A. m. capensis. The Euclidean distances for the beeswaxes are consistent with currently prevailing phylogenies for Apis. Despite post-speciation chemical differences in the beeswaxes, they remain largely acceptable interspecifically while the plant and mineral waxes are not chemically close enough to beeswax for their acceptance.

  1. Geometric accuracy of wax bade models manufactured in silicon moulds

    Directory of Open Access Journals (Sweden)

    G. Budzik

    2010-01-01

    Full Text Available The article presents the test results of the geometric accuracy of wax blade models manufactured in silicon moulds in the Rapid Tooling process, with the application of the Vacuum Casting technology. In batch production casting waxes are designed for the manufacture of models and components of model sets through injection into a metal die. The objective of the tests was to determine the possibility of using traditional wax for the production of casting models in the rapid prototyping process. Blade models made of five types of casting wax were measured. The definition of the geometric accuracy of wax blade models makes it possible to introduce individual modifications aimed at improving their shape in order to increase the dimensional accuracy of blade models manufactured in the rapid prototyping process.

  2. Self-Replenishable Anti-Waxing Organogel Materials.

    Science.gov (United States)

    Yao, Xi; Wu, Shuwang; Chen, Lie; Ju, Jie; Gu, Zhandong; Liu, Mingjie; Wang, Jianjun; Jiang, Lei

    2015-07-27

    Solid deposition, such as the formation of ice on outdoor facilities, the deposition of scale in water reservoirs, the sedimentation of fat, oil, and grease (FOG) in sewer systems, and the precipitation of wax in petroleum pipelines, cause a serious waste of resources and irreversible environmental pollution. Inspired by fish and pitcher plants, we present a self-replenishable organogel material which shows ultra-low adhesion to solidified paraffin wax and crude oil by absorption of low-molar-mass oil from its crude-oil environment. Adhesion of wax on the organogel surface was over 500 times lower than adhesion to conventional material surfaces and the wax was found to slide off under the force of gravity. This design concept of a gel with decreased adhesion to wax and oil can be extended to deal with other solid deposition problems.

  3. Self‐Replenishable Anti‐Waxing Organogel Materials†

    Science.gov (United States)

    Yao, Xi; Wu, Shuwang; Chen, Lie; Ju, Jie; Gu, Zhandong; Liu, Mingjie; Jiang, Lei

    2015-01-01

    Abstract Solid deposition, such as the formation of ice on outdoor facilities, the deposition of scale in water reservoirs, the sedimentation of fat, oil, and grease (FOG) in sewer systems, and the precipitation of wax in petroleum pipelines, cause a serious waste of resources and irreversible environmental pollution. Inspired by fish and pitcher plants, we present a self‐replenishable organogel material which shows ultra‐low adhesion to solidified paraffin wax and crude oil by absorption of low‐molar‐mass oil from its crude‐oil environment. Adhesion of wax on the organogel surface was over 500 times lower than adhesion to conventional material surfaces and the wax was found to slide off under the force of gravity. This design concept of a gel with decreased adhesion to wax and oil can be extended to deal with other solid deposition problems. PMID:26083324

  4. Pickering emulsions stabilized by paraffin wax and Laponite clay particles.

    Science.gov (United States)

    Li, Caifu; Liu, Qian; Mei, Zhen; Wang, Jun; Xu, Jian; Sun, Dejun

    2009-08-01

    Emulsions containing wax in dispersed droplets stabilized by disc-like Laponite clay particles are prepared. Properties of the emulsions prepared at different temperatures are examined using stability, microscopy and droplet-size analysis. At low temperature, the wax crystals in the oil droplets can protrude through the interface, leading to droplet coalescence. But at higher temperatures, the droplet size decreases with wax concentration. Considering the viscosity of the oil phase and the interfacial tension, we conclude that the wax is liquid-like during the high temperature emulsification process, but during cooling wax crystals appear around the oil/water interface and stabilize the droplets. The oil/water ratio has minimal effect on the emulsions between ratios of 3:7 and 7:3. The Laponite is believed to stabilize the emulsions by increasing the viscosity of the continuous phase and also by adsorbing at the oil/water interface, thus providing a physical barrier to coalescence.

  5. Molten salt reactors - safety options galore

    Energy Technology Data Exchange (ETDEWEB)

    Gat, U. [Oak Ridge National Lab., TN (United States); Dodds, H.L. [Univ. of Tennessee, Knoxville, TN (United States)

    1997-03-01

    Safety features and attributes of molten salt reactors (MSR) are described. The unique features of fluid fuel reactors of on-line continuous processing and the ability for so-called external cooling result in simple and safe designs with low excess reactivity, low fission product inventory, and small source term. These, in turn, make a criticality accident unlikely and reduce the severity of a loss of coolant to where they are no longer severe accidents. A melt down is not an accident for a reactor that uses molten fuel. The molten salts are stable, non-reactive and efficient heat transfer media that operate at high temperatures at low pressures and are highly compatible with selected structural materials. All these features reduce the accident plethora. Freeze valves can be used for added safety. An ultimate safe reactor (U.S.R) is described with safety features that are passive, inherent and non-tamperable (PINT).

  6. Electroreduction Kinetics for Molten Oxide Slags

    Institute of Scientific and Technical Information of China (English)

    GAO Yun-ming; CHOU Kuo-chih; GUO Xing-min; WANG Wei

    2007-01-01

    The oxygen-ion conductor, the reducing agent, and the molten oxide slag containing electroactive matter were used as constituent of a galvanic cell. Metal was directly electroreduced from molten slag using a short-circuit galvanic cell. The following galvanic cell was assembled in the present experiment: graphite rod, [O]Fe-C saturated|ZrO2(MgO)|Cu(l)+(FeO)(slag), and molybdenum wire. The FeO electroreduction reaction was studied through measuring short circuit current by controlling factors such as temperature, the FeO content in molten slags, and the external circuit resistance. An overall kinetics model was developed to describe the process of FeO electroreduction. It was found that the modeled curves were in good agreement with the experimental values. The new oxide reduction method in the metallurgy with controlled oxygen flow was proposed and the metallurgical theory with controlled oxygen flow was developed.

  7. Good night, squashbite: a 'how to' paper on better wax occlusal records.

    Science.gov (United States)

    Shargill, Inderjit; Ashley, Martin

    2006-12-01

    During the technical stages of dental treatment, a dental technician may only be able to unite a set of dental casts in a 'best-guess' relationship, unless they are either able to examine the patient themselves, or are given further information about the occlusal position chosen during the clinical procedure. The most common method for this is to use some form of occlusal record, which can be created from a variety of techniques and materials, such as either one of the dental waxes or one of the more recently introduced syringable materials. This paper describes a better technique for using dental wax to make occlusal records. The 'squashbite' technique has no place in clinical dentistry for those attempting to obtain accurate results.

  8. Detailed characterization of the substrate specificity of mouse wax synthase.

    Science.gov (United States)

    Miklaszewska, Magdalena; Kawiński, Adam; Banaś, Antoni

    2013-01-01

    Wax synthases are membrane-associated enzymes catalysing the esterification reaction between fatty acyl-CoA and a long chain fatty alcohol. In living organisms, wax esters function as storage materials or provide protection against harmful environmental influences. In industry, they are used as ingredients for the production of lubricants, pharmaceuticals, and cosmetics. Currently the biological sources of wax esters are limited to jojoba oil. In order to establish a large-scale production of desired wax esters in transgenic high-yielding oilseed plants, enzymes involved in wax esters synthesis from different biological resources should be characterized in detail taking into consideration their substrate specificity. Therefore, this study aims at determining the substrate specificity of one of such enzymes -- the mouse wax synthase. The gene encoding this enzyme was expressed heterologously in Saccharomyces cerevisiae. In the in vitro assays (using microsomal fraction from transgenic yeast), we evaluated the preferences of mouse wax synthase towards a set of combinations of 11 acyl-CoAs with 17 fatty alcohols. The highest activity was observed for 14:0-CoA, 12:0-CoA, and 16:0-CoA in combination with medium chain alcohols (up to 5.2, 3.4, and 3.3 nmol wax esters/min/mg microsomal protein, respectively). Unsaturated alcohols longer than 18°C were better utilized by the enzyme in comparison to the saturated ones. Combinations of all tested alcohols with 20:0-CoA, 22:1-CoA, or Ric-CoA were poorly utilized by the enzyme, and conjugated acyl-CoAs were not utilized at all. Apart from the wax synthase activity, mouse wax synthase also exhibited a very low acyl-CoA:diacylglycerol acyltransferase activity. However, it displayed neither acyl-CoA:monoacylglycerol acyltransferase, nor acyl-CoA:sterol acyltransferase activity.

  9. Direct contact heat recovery from molten salt

    Science.gov (United States)

    Technological deficiencies associated with efficient and economical retrieval of heat energy from molten salt systems are addressed. The large latent heat of fusion stored in molten salt hydrates and other candidate phase change materials (PCM) is removed by internal boiling of a volatile heat transfer fluid (HTF). This procedure eliminates the conventional use of submerged heat exchangers which are costly and, in crystallizing salts, ineffective. The thermochemical conditions and material properties that are critical for application of this concept in environments that yield significant energy savings are investigated and defined.

  10. Experimental studies of actinides in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Reavis, J.G.

    1985-06-01

    This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs.

  11. Simulation on flow process of filtered molten metals

    Institute of Scientific and Technical Information of China (English)

    房文斌; 耿耀宏; 魏尊杰; 安阁英; 叶荣茂

    2002-01-01

    Filtration and flow process of molten metals was analyzed by water simulation experiments. Fluid dynamic phenomena of molten metal cells through a foam ceramic filter was described and calculated by ERGOR equation as well. The results show that the filter is most useful for stable molten metals and the filtered flow is laminar, so that inclusions can be removed more effectively.

  12. Plant surface wax affects parasitoid's response to host footprints

    Science.gov (United States)

    Rostás, Michael; Ruf, Daniel; Zabka, Vanessa; Hildebrandt, Ulrich

    2008-10-01

    The plant surface is the substrate upon which herbivorous insects and natural enemies meet and thus represents the stage for interactions between the three trophic levels. Plant surfaces are covered by an epicuticular wax layer which is highly variable depending on species, cultivar or plant part. Differences in wax chemistry may modulate ecological interactions. We explored whether caterpillars of Spodoptera frugiperda, when walking over a plant surface, leave a chemical trail (kairomones) that can be detected by the parasitoid Cotesia marginiventris. Chemistry and micromorphology of cuticular waxes of two barley eceriferum wax mutants ( cer-za.126, cer-yp.949) and wild-type cv. Bonus (wt) were assessed. The plants were then used to investigate potential surface effects on the detectability of caterpillar kairomones. Here we provide evidence that C. marginiventris responds to chemical footprints of its host. Parasitoids were able to detect the kairomone on wild-type plants and on both cer mutants but the response to cer-yp.949 (reduced wax, high aldehyde fraction) was less pronounced. Experiments with caterpillar-treated wt and mutant leaves offered simultaneously, confirmed this observation: no difference in wasp response was found when wt was tested against cer-za.126 (reduced wax, wt-like chemical composition) but wt was significantly more attractive than cer-yp.949. This demonstrates for the first time that the wax layer can modulate the detectability of host kairomones.

  13. Chemical and physical analyses of wax ester properties

    Directory of Open Access Journals (Sweden)

    Sejal Patel

    2001-05-01

    Full Text Available Wax esters are major constituents of the surface lipids in many terrestrial arthropods, but their study is complicated by their diversity. We developed a procedure for quantifying isomers in mixtures of straight-chain saturated and unsaturated wax esters having the same molecular weights, using single-ion monitoring of the total ion current data from gas chromatography-mass spectrometry. We examined the biological consequences of structural differences by measuring the melting temperatures, Tm, of >60 synthetic wax esters, containing 26-48 carbon atoms. Compounds containing saturated alcohol and acid moieties melted at 38-73°C. The main factor affecting Tm was the total chain length of the wax ester, but the placement of the ester bond also affected Tm. Insertion of a double bond into either the alcohol or acid moiety decreased Tm by ~30°C. Simple mixtures of wax esters with n-alkanes melted several °C lower than predicted from the melting points of the component lipids. Our results indicate that the wax esters of primary alcohols that are most typically found on the cuticle of terrestrial arthropods occur in a solid state under physiological conditions, thereby conferring greater waterproofing. Wax esters of secondary alcohols, which occur on melanopline grasshoppers, melted >60°C below primary esters of the same molecular weight and reduced Tm of the total surface lipids to environmental values.

  14. Application of U-fixed red wax mask in radiotherapy

    Institute of Scientific and Technical Information of China (English)

    Kejia Liu; Jing Song; Rui Song; Zhiyong Liu; Gang Ni; Wei Ge

    2014-01-01

    Objective:The aim of our study was to compared non-red wax compensator and adding red wax compensator in the treatment plans of the minimum dose, maximum dose, mean dose and target surface dose, and compare the dose volume histograms (DVH) parameters and isodose distributions of two plans. Methods:From January 2009 to December 2010, 8 patients with superficial head and neck cancer and without surgery treatment were col ected. They al confirmed by cancer center, Tianmen First People’s Hospital. Topslane WiMRT was used to design the treatment plan of non-red wax compensa-tor and adding red wax compensator, with 6 MV photons using three-dimensional conformal irradiation mode design, the prescription dose was 50 Gy/25 times. Results:Compared non-red wax compensator with adding red wax compensator, its target minimum dose (t=-3.157, P0.05) and mean dose (t=-9.914, P>0.05) were considered no significant dif erence. Conclusion:The use of U-shaped mask fixed red wax film production in conformal radiotherapy tissue compensator can significantly improve the surface dose and dose distribution superficial planning target volume.

  15. Oxygen electrode in molten carbonate fuel cells

    Science.gov (United States)

    Dave, B. B.; White, R. E.; Srinivasan, S.; Appleby, A. J.

    1990-12-01

    During this quarter, impedance data were analyzed for an oxygen reduction process in molten carbonate electrolyte and a manuscript, Impedance Analysis for Oxygen Reduction in a Lithium Carbonate Melt: Effects of Partial Pressure of Carbon Dioxide and Temperature, was prepared to be submitted to Journal of the Electrochemical Society for publication.

  16. Studies on the compressibility of wax matrix granules of acetaminophen and their admixtures with various tableting bases.

    Science.gov (United States)

    Uhumwangho, M U; Okor, R S

    2006-04-01

    Matrix granules of acetaminophen have been formed by a melt granulation process whereby the acetaminophen powder was triturated with the melted wax--goat wax, glyceryl monostearate or carnuba wax. The compressibility of the matrix granules and their admixture, with diluent granules (lactose, alpha-cellulose or microcrystalline cellulose) was investigated. The granules were compressed to tablets at a constant load (30 arbitrary units on the load scale) of a manesty single punch machine. Resulting tablets were evaluated for tensile strength (T) and disintegration times (DT). Granule flow was determined by measuring their angle of repose when allowed to fall freely on a level surface. Matrix granules prepared by melt granulation with goat wax or glyceryl monostearate were too sticky and therefore did not flow at all. They were also poorly compressible (T values = 0.20MN/m2). Inclusion of the diluent remarkably improved granule flow property and compressibility. The T values of the tablets (measure of compressibility) increased from about 0.24 to 0.65 MN/m2 during increase in diluent (lactose) content from 20 to 80 %w/w. Microcrystalline cellulose and alpha-cellulose were more effective than lactose in promoting compressibility of the granules. By contrast the matrix granules formed with carnuba wax were free flowing (angle of repose, 18.60). Addition of the diluent further improved flowability slightly. The matrix granules (without a diluent) were readily compressible (T value, 1.79MN/m2). Addition of the diluent (80%w/w) reduced T values (MN/m2) slightly to 1.32 (lactose), 1.48 (alpha-cellulose) and 1.74 (microcrystalline cellulose). Tablets of the matrix granules only, disintegrated rapidly within 3 minutes. DT was further reduced to wax proved most promising in the melt granulation of the test drug for sustained release applications.

  17. Heat transfer behavior of molten nitrate salt

    Science.gov (United States)

    Das, Apurba K.; Clark, Michael M.; Teigen, Bard C.; Fiveland, Woodrow A.; Anderson, Mark H.

    2016-05-01

    The usage of molten nitrate salt as heat transfer fluid and thermal storage medium decouples the generation of electricity from the variable nature of the solar resource, allowing CSP plants to avoid curtailment and match production with demand. This however brings some unique challenges for the design of the molten salt central receiver (MSCR). An aspect critical to the use of molten nitrate (60wt%/40wt% - NaNO3/KNO3) salt as heat transfer fluid in the MSCR is to understand its heat transfer behavior. Alstom collaborated with the University of Wisconsin to conduct a series of experiments and experimentally determined the heat transfer coefficients of molten nitrate salt up to high Reynolds number (Re > 2.0E5) and heat flux (q″ > 1000 kW/m2), conditions heretofore not reported in the literature. A cartridge heater instrumented with thermocouples was installed inside a stainless steel pipe to form an annular test section. The test section was installed in the molten salt flow loop at the University of Wisconsin facility, and operated over a range of test conditions to determine heat transfer data that covered the expected operating regime of a practical molten salt receiver. Heat transfer data were compared to widely accepted correlations found in heat transfer literature, including that of Gnielinski. At lower Reynolds number conditions, the results from this work concurred with the molten salt heat transfer data reported in literature and followed the aforementioned correlations. However, in the region of interest for practical receiver design, the correlations did not accurately model the experimentally determined heat transfer data. Two major effects were observed: (i) all other factors remaining constant, the Nusselt numbers gradually plateaued at higher Reynolds number; and (ii) at higher Reynolds number a positive interaction of heat flux on Nusselt number was noted. These effects are definitely not modeled by the existing correlations. In this paper a new

  18. Rapid Prototyping of wax foundry models in an incremental process

    Directory of Open Access Journals (Sweden)

    B. Kozik

    2011-04-01

    Full Text Available The paper presents an analysis incremental methods of creating wax founding models. There are two methods of Rapid Prototypingof wax models in an incremental process which are more and more often used in industrial practice and in scientific research.Applying Rapid Prototyping methods in the process of making casts allows for acceleration of work on preparing prototypes. It isespecially important in case of element having complicated shapes. The time of making a wax model depending on the size and the appliedRP method may vary from several to a few dozen hours.

  19. Effect of epicuticular wax crystals on the localization of artificially deposited sub-micron carbon-based aerosols on needles of Cryptomeria japonica.

    Science.gov (United States)

    Nakaba, Satoshi; Yamane, Kenichi; Fukahori, Mie; Nugroho, Widyanto Dwi; Yamaguchi, Masahiro; Kuroda, Katsushi; Sano, Yuzou; Wuled Lenggoro, I; Izuta, Takeshi; Funada, Ryo

    2016-09-01

    Elucidation of the mechanism of adsorption of particles suspended in the gas-phase (aerosol) to the outer surfaces of leaves provides useful information for understanding the mechanisms of the effect of aerosol particles on the growth and physiological functions of trees. In the present study, we examined the localization of artificially deposited sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica, a typical Japanese coniferous tree species, by field-emission scanning electron microscopy. The clusters (aggregates) of carbon-based particles were deposited on the needle surface regions where epicuticular wax crystals were sparsely distributed. By contrast, no clusters of the particles were found on the needle surface regions with dense distribution of epicuticular wax crystals. Number of clusters of carbon-based particles per unit area showed statistically significant differences between regions with sparse epicuticular wax crystals and those with dense epicuticular wax crystals. These results suggest that epicuticular wax crystals affect distribution of carbon-based particles on needles. Therefore, densely distributed epicuticular wax crystals might prevent the deposition of sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica to retain the function of stomata.

  20. Quantitative trait loci controlling amounts and types of epicuticular waxes in onion

    Science.gov (United States)

    Natural variation exists in onion (Allium cepa L.) for amounts and types of epicuticular waxes on leaves. Wild-type waxy onion possesses copious amounts of these waxes, while the foliage of semi-glossy and glossy phenotypes accumulate significantly less wax. Reduced amounts of epicuticular waxes hav...

  1. Trans-fat free margarine from organogel formed by a plant wax

    Science.gov (United States)

    This research presents a practical method to replace a hardstock containing trans-fat and saturated fat with a small amount of a plant wax in margarine and spreads. Plant waxes were investigated for their ability to make an organogel of many different vegetable oils. Sunflower wax and rice bran wax ...

  2. Properties of cookies made with natural wax-vegetable oil organogels

    Science.gov (United States)

    Organogels prepared with a natural wax and a vegetable oil were examined as alternatives to a commercial margarine in cookie. To investigate effects of wax and vegetable oil on properties of cookie dough and cookies, organogels prepared from four different waxes including sunflower wax, rice bran wa...

  3. Mechanical properties of carving wax with various Ca-bentolite filter composition

    OpenAIRE

    Widjijono Widjijono; Purwanto Agustiono; Dyah Irnawati

    2009-01-01

    Background: The carving wax is used as a medium in dental anatomy study. This wax composes of many waxes and sometimes a filler is added. Carving wax is not sold in Indonesian market. Whereas the gradients of carving wax such as beeswax, paraffin and bentonite are abundant in Indonesia. Based on that fact, to make high quality and standard,the exact composition if this carving wax should be known. Purpose: The aim of this study was to investigate the effect of carving wax composition with Ca-...

  4. Effect of the epicuticular waxes of fruits and vegetables on the photodegradation of rotenone.

    Science.gov (United States)

    Angioni, Alberto; Cabizza, Maddalena; Cabras, Marco; Melis, Marinella; Tuberoso, Carlo; Cabras, Paolo

    2004-06-02

    The effect of epicuticular waxes extracted from fruits (apple, nectarine, pear, and plum) and vegetables (tomato and eggplant) on the photodegradation of rotenone was studied. The waxes affected the decay rate and the degradation pathway of this botanical insecticide. Tomato, nectarine, and plum waxes decreased the photodegradation rate compared to controls, whereas apple and pear waxes increased it. Rotenone irradiated under sunlight without waxes gave seven photoproducts; in contrast, in the presence of waxes it changed its behavior, leading to different pathways according to the wax employed. The main photoproduct formed was 12abeta-rotenolone.

  5. Feet sunk in molten aluminium: The burn and its prevention.

    Science.gov (United States)

    Alonso-Peña, David; Arnáiz-García, María Elena; Valero-Gasalla, Javier Luis; Arnáiz-García, Ana María; Campillo-Campaña, Ramón; Alonso-Peña, Javier; González-Santos, Jose María; Fernández-Díaz, Alaska Leonor; Arnáiz, Javier

    2015-08-01

    Nowadays, despite improvements in safety rules and inspections in the metal industry, foundry workers are not free from burn accidents. Injuries caused by molten metals include burns secondary to molten iron, aluminium, zinc, copper, brass, bronze, manganese, lead and steel. Molten aluminium is one of the most common causative agents of burns (60%); however, only a few publications exist concerning injuries from molten aluminium. The main mechanisms of lesion from molten aluminium include direct contact of the molten metal with the skin or through safety apparel, or when the metal splash burns through the pants and rolls downward along the leg. Herein, we report three cases of deep dermal burns after 'soaking' the foot in liquid aluminium and its evolutive features. This paper aims to show our experience in the management of burns due to molten aluminium. We describe the current management principles and the key features of injury prevention. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  6. Developmental and Genotypic Variation in Leaf Wax Content and Composition, and in Expression of Wax Biosynthetic Genes in Brassica oleracea var. capitata

    Science.gov (United States)

    Laila, Rawnak; Robin, Arif Hasan Khan; Yang, Kiwoung; Park, Jong-In; Suh, Mi Chung; Kim, Juyoung; Nou, Ill-Sup

    2017-01-01

    Cuticular waxes act as a protective barrier against environmental stresses. In the present study, we investigated developmental and genotypic variation in wax formation of cabbage lines, with a view to understand the related morphology, genetics and biochemistry. Our studies revealed that the relative expression levels of wax biosynthetic genes in the first-formed leaf of the highest-wax line remained constantly higher but were decreased in other genotypes with leaf aging. Similarly, the expression of most of the tested genes exhibited decrease from the inner leaves to the outer leaves of 5-month-old cabbage heads in the low-wax lines in contrast to the highest-wax line. In 10-week-old plants, expression of wax biosynthetic genes followed a quadratic function and was generally increased in the early developing leaves but substantially decreased at the older leaves. The waxy compounds in all cabbage lines were predominately C29-alkane, -secondary alcohol, and -ketone. Its deposition was increased with leaf age in 5-month-old plants. The high-wax lines had dense, prominent and larger crystals on the leaf surface compared to low-wax lines under scanning electron microscopy. Principal component analysis revealed that the higher expression of LTP2 genes in the lowest-wax line and the higher expression of CER3 gene in the highest-wax line were probably associated with the comparatively lower and higher wax content in those two lines, respectively. This study furthers our understanding of the relationships between the expression of wax biosynthetic genes and the wax deposition in cabbage lines. Highlight: In cabbage, expression of wax-biosynthetic genes was generally decreased in older and senescing leaves, while wax deposition was increased with leaf aging, and C29-hydrocarbon was predominant in the wax crystals. PMID:28119701

  7. Cucumis sativus L. WAX2 Plays a Pivotal Role in Wax Biosynthesis, Influencing Pollen Fertility and Plant Biotic and Abiotic Stress Responses.

    Science.gov (United States)

    Wang, Wenjiao; Liu, Xingwang; Gai, Xinshuang; Ren, Jiaojiao; Liu, Xiaofeng; Cai, Yanling; Wang, Qian; Ren, Huazhong

    2015-07-01

    Cuticular waxes play an important part in protecting plant aerial organs from biotic and abiotic stresses. In previous studies, the biosynthetic pathway of cuticular waxes and relative functional genes has been researched and understood; however, little is known in cucumber (Cucumis sativus L.). In this study, we cloned and characterized an AtWAX2 homolog, CsWAX2, in cucumber and found that it is highly expressed in the epidermis, where waxes are synthesized, while subcellular localization showed that CsWAX2 protein is localized to the endoplasmic reticulum (ER). The transcriptional expression of CsWAX2 was found to be induced by low temperature, drought, salt stress and ABA, while the ectopic expression of CsWAX2 in an Arabidopsis wax2 mutant could partially complement the glossy stem phenotype. Abnormal expression of CsWAX2 in transgenic cucumbers specifically affected both very long chain (VLC) alkanes and cutin biosynthesis. Furthermore, transgenic cucumber plants of CsWAX2 showed significant changes in pollen viability and fruit resistance to water loss and pathogens compared with the wild type. Collectively, these results indicated that CsWAX2 plays a pivotal role in wax biosynthesis, influencing pollen fertility and the plant's response to biotic and abiotic stresses.

  8. THE USE OF MODERN FACILITIES FOR FREEZING WAX SUBSTANCES

    Directory of Open Access Journals (Sweden)

    S. M. Iashchenko

    2014-01-01

    Full Text Available Summary. The basic directions of use, frozen vegetable oil, an analysis of markets. Analyzed trends in the development of cryogenic freezing. The urgency of developing energy efficient cryogenic devices. Integrated approach to the development of competitive domestic technologies and equipment for cryogenic freezing of vegetable oils is to use effective and innovative cooling techniques, process intensification, reduction of specific energy consumption and, consequently, reducing the cost of production in achieving high quality performance. The advantages of using an inert gas vapor as an alternative direction for existing equipment freezing wax-like substances using brine or water cooling. The investigations of cryogenic freezing using nitrogen vapor. Scientifically confirmed that oil bubbling nitrogen vapor layer, helps to increase the cooling capacity due to the thermal capacity and significantly reduces the processing time. Variants of using cryogenic coolant in the chiller plant. The optimal thermal, geometric and hydrodynamic modes. The ways to improve energy efficiency cryogenic apparatus using cryogenic coolant. The results will produce engineering calculations and design of freezing progressive installations with different technological modes. The conditions for cooling food liquids by bubbling with possibility of integration of physical and chemical characteristics of the cooled product. Cryogenic unit designed for continuous freezing of vegetable oils increased efficiency to the process of automatic control. Confirmed the economic efficiency of cleaning oils from impurities in continuous cryogenic apparatus by reducing the amount of equipment on similar processes in the preparation of the final product with a high degree of purification.

  9. The Effects of Stress on Plant Cuticular Waxes

    National Research Council Canada - National Science Library

    Tom Shepherd; D. Wynne Griffiths

    2006-01-01

    Plants are subject to a wide range of abiotic stresses, and their cuticular wax layer provides a protective barrier, which consists predominantly of long-chain hydrocarbon compounds, including alkanes...

  10. RDX/Polyethylene Wax Compositions as Pressed Explosive,

    Science.gov (United States)

    1978-09-01

    polymeric binder, which is poured or extruded into the round and allowed to cure in situ to obtain a solid charge. The second approach is to coat a...explosive component, and an emulsifiable polyethylene wax , which has been suggested as a possible phiegmatiser to replace or supplement beeswax in...rough irregular surfaces of these particles that the wax does not actually coat the explosive, at least at these small concentra tions , but rather the

  11. Effects of UV-B radiation on wax biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, J. [Dept. of Agricultural and Environmental Science, Newcastle-Upon-Tyne (United Kingdom); Paul, N. [Dept. of Agricultural and Environmental Science, Newcastle-Upon-Tyne (United Kingdom)]|[Inst. of Environmental and Biological Sciences, Lancaster Univ. (United Kingdom); Percy, K. [Dept. of Agricultural and Environmental Science, Newcastle-Upon-Tyne (United Kingdom)]|[Canadian Forest Service, Natural Resources Canada, Fredericton, NB (Canada); Broadbent, P. [Dept. of Agricultural and Environmental Science, Newcastle-Upon-Tyne (United Kingdom)]|[Inst. of Environmental and Biological Sciences, Lancaster Univ. (United Kingdom); McLaughlin, C. [Dept. of Agricultural and Environmental Science, Newcastle-Upon-Tyne (United Kingdom)]|[Canadian Forest Service, Natural Resources Canada, Fredericton, NB (Canada); Mullineaux, P. [Dept. of Agricultural and Environmental Science, Newcastle-Upon-Tyne (United Kingdom)]|[John Innes Inst., Norwich (United Kingdom); Creissen, G. [Dept. of Agricultural and Environmental Science, Newcastle-Upon-Tyne (United Kingdom)]|[John Innes Inst., Norwich (United Kingdom); Wellburn, A. [Dept. of Agricultural and Environmental Science, Newcastle-Upon-Tyne (United Kingdom)]|[Inst. of Environmental and Biological Sciences, Lancaster Univ. (United Kingdom)

    1994-12-31

    Two genotypes of tobacco (Nicotiana tabacum L.) were exposed in controlled environment chambers to three levels of biologically effective ultraviolet-B radiation (UV-B{sub BE}; 280-320nm): 0, 4.54 (ambient) and 5.66 ({approx} 25% enhancement) kJ m{sup -2} d{sup -1}. After 28 days, the quantity of wax deposited on leaf surfaces was determined gravimetrically; epicuticular wax chemical composition was determined by capillary gas chromatography with homologue assignments confirmed by gas chromatography-mass spectrometry. Leaf wettability was assessed by measuring the contact angle of water droplets placed on leaf surfaces. Tobacco wax consisted of three major hydrocarbon classes: Straight-chain alkanes (C{sub 27}-C{sub 33}) which comprised {approx} 59% of the hydrocarbon fraction, containing a predominance of odd-chain alkanes with C{sub 31} as the most abundant homologue; branched-chain alkanes (C{sub 25}-C{sub 32}) which comprised {approx}38% of the hydrocarbon fraction with anteiso 3-methyltriacontane (C{sub 30}) as the predominant homologue; and fatty acids (C{sub 14}-C{sub 18}) which comprised {approx} 3% of the wax. Exposure to enhanced UV-B radiation reduced the quantity of wax on the adaxial surface of the transgenic mutant, and resulted in marked changes in the chemical composition of the wax on the exposed leaf surface. Enhanced UV-B decreased the quantity of straight-chain alkanes, increased the quantity of branched-chain alkanes and fatty acids, and resulted in shifts toward shorter straight-chain lengths. Furthermore, UV-B-induced changes in wax composition were associated with increased wettability of tobacco leaf surfaces. Overall, the data are consistent with the view that UV-B radiation has a direct and fundamental effect on wax biosynthesis. Relationships between the physico-chemical nature of the leaf surface and sensitivity to UV-B radiation are discussed. (orig.)

  12. Melt Adsorption as a Manufacturing Method for Fine Particles of Wax Matrices without Any Agglomerates.

    Science.gov (United States)

    Shiino, Kai; Fujinami, Yukari; Kimura, Shin-Ichiro; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru

    2017-01-01

    We have focused on melt adsorption as manufacture method of wax matrices to control particles size of granules more easily than melt granulation. The purpose of present study was to investigate the possibility of identifying a hydrophobic material with a low melting point, currently used as a meltable binder of melt granulation, to apply as a novel carrier in melt adsorption. Glyceryl monostearate (GM) and stearic acid (SA) were selected as candidate hydrophobic materials with low melting points. Neusilin US2 (US2), with a particle diameter of around 100 µm was selected as a surface adsorbent, while dibasic calcium phosphate dihydrate (DCPD), was used as a non-adsorbent control to prepare melting granules as a standard for comparison. We prepared granules containing ibuprofen (IBU) by melt adsorption or melt granulation and evaluated the particle size, physical properties and crystallinity of granules. Compared with melt granulation using DCPD, melt adsorption can be performed over a wide range of 14 to 70% for the ratio of molten components. Moreover, the particle size; d50 of obtained granules was 100-200 µm, and these physical properties showed good flowability and roundness. The process of melt adsorption did not affect the crystalline form of IBU. Therefore, the present study has demonstrated for the first time that melt adsorption using a hydrophobic material, GM or SA, has the potential capability to control the particle size of granules and offers the possibility of application as a novel controlled release technique.

  13. Magnetic properties of MnFe2O4 nano-aggregates dispersed in paraffin wax

    Science.gov (United States)

    Aslibeiki, B.; Kameli, P.

    2015-07-01

    Manganese ferrite, MnFe2O4 nanoparticles with average size of ∼6.5 nm were synthesized by using a thermal decomposition method. The nanoparticles were aggregated which was confirmed by FESEM and TEM images. The aggregates with a diameter of ∼50 nm showed interacting superspin glass (SSG) behavior. The powders were dispersed in the molten paraffin wax by using ultrasonic bath. Samples with different paraffin/ferrite weight ratios of P/F= 0, 1, 5, 10 and 20 were prepared. M-H curves of the samples revealed presence of superparamagnetic state at 300 K. Saturation magnetization (Ms) decreased from 26.6 to 1.3 emu/g by increasing the P/F value from 0 to 20, respectively. Furthermore, the VSM measurements showed a decrease in surface spin disorder of paraffin-embedded nanoparticles in comparison with bare particles. The AC magnetic susceptibility peak temperature, TP increased from 230 to >300 K with increasing the paraffin content in the samples. The present study showed that by dispersing the particles in a non-magnetic matrix, the blocking temperature could be increased.

  14. Nest wax triggers worker reproduction in the bumblebee Bombus terrestris.

    Science.gov (United States)

    Rottler-Hoermann, Ann-Marie; Schulz, Stefan; Ayasse, Manfred

    2016-01-01

    Social insects are well known for their high level of cooperation. Workers of the primitively eusocial bumblebee Bombus terrestris are able to produce male offspring in the presence of a queen. Nonetheless, they only compete for reproduction, in the so-called competition phase, when the workforce is large enough to support the rearing of reproductives. So far, little is known about the proximate mechanisms underlying the shift between altruism and selfish behaviour in bumblebee workers. In this study, we have examined the influence of chemical cues from the nest wax on the onset of worker reproduction. Chemical analyses of wax extracts have revealed that the patterns and amounts of cuticular lipids change considerably during colony development. These changes in wax scent mirror worker abundance and the presence of fertile workers. In bioassays with queen-right worker groups, wax affects the dominance behaviour and ovarian development of workers. When exposed to wax from a colony in competition phase, workers start to compete for reproduction. We suggest that wax scent enables workers to time their reproduction by providing essential information concerning the social condition of the colony.

  15. Influence of microcrystalline wax on properties of MIM multi-component wax matrix binder

    Institute of Scientific and Technical Information of China (English)

    张健; 黄伯云; 李益民; 李松林

    2002-01-01

    The properties of PW-EVA-HDPE binder with the addition of MW were studied. It shows that the addition of MW from 1% to 20%(mass fraction) causes an increase in the tensile strength and a decrease in shrinkage of the binder. After blending PW with MW, the crystallation behavior of wax base changes, which results in fine grain for the binder and more isotropic microstructure for the feedstock. The powder loading capacity increases and homogeneity of feedstock becomes better. The reason of the modification is also discussed.

  16. Molten uranium dioxide structure and dynamics.

    Science.gov (United States)

    Skinner, L B; Benmore, C J; Weber, J K R; Williamson, M A; Tamalonis, A; Hebden, A; Wiencek, T; Alderman, O L G; Guthrie, M; Leibowitz, L; Parise, J B

    2014-11-21

    Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. On melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts.

  17. High Power Molten Targets for Radioactive Ion Beam Production: from Particle Physics to Medical Applications

    CERN Document Server

    De Melo Mendonca, T M

    2014-01-01

    Megawatt-class molten targets, combining high material densities and good heat transfer properties are being considered for neutron spallation sources, neutrino physics facilities and radioactive ion beam production. For this last category of facilities, in order to cope with the limitation of long diffusion times affecting the extraction of short-lived isotopes, a lead-bismuth eutectic (LBE) target loop equipped with a diffusion chamber has been proposed and tested offline during the EURISOL design study. To validate the concept, a molten LBE loop is now in the design phase and will be prototyped and tested on-line at CERN-ISOLDE. This concept was further extended to an alternative route to produce 1013 18Ne/s for the Beta Beams, where a molten salt loop would be irradiated with 7 mA, 160 MeV proton beam. Some elements of the concept have been tested by using a molten fluoride salt static unit at CERNISOLDE. The investigation of the release and production of neon isotopes allowed the measurement of the diffu...

  18. Molten metal holder furnace and casting system incorporating the molten metal holder furnace

    Science.gov (United States)

    Kinosz, Michael J.; Meyer, Thomas N.

    2003-02-11

    A bottom heated holder furnace (12) for containing a supply of molten metal includes a storage vessel (30) having sidewalls (32) and a bottom wall (34) defining a molten metal receiving chamber (36). A furnace insulating layer (42) lines the molten metal receiving chamber (36). A thermally conductive heat exchanger block (54) is located at the bottom of the molten metal receiving chamber (36) for heating the supply of molten metal. The heat exchanger block (54) includes a bottom face (65), side faces (66), and a top face (67). The heat exchanger block (54) includes a plurality of electrical heaters (70) extending therein and projecting outward from at least one of the faces of the heat exchanger block (54), and further extending through the furnace insulating layer (42) and one of the sidewalls (32) of the storage vessel (30) for connection to a source of electrical power. A sealing layer (50) covers the bottom face (65) and side faces (66) of the heat exchanger block (54) such that the heat exchanger block (54) is substantially separated from contact with the furnace insulating layer (42).

  19. Multiply manifolded molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Krumpelt, M.; Roche, M.F.; Geyer, H.K.; Johnson, S.A.

    1994-08-01

    This study consists of research and development activities related to the concept of a molten carbonate fuel cell (MCFC) with multiple manifolds. Objective is to develop an MCFC having a higher power density and a longer life than other MCFC designs. The higher power density will result from thinner gas flow channels; the extended life will result from reduced temperature gradients. Simplification of the gas flow channels and current collectors may also significantly reduce cost for the multiply manifolded MCFC.

  20. Is wax equivalent to tissue in electron conformal therapy planning? A Monte Carlo study of material approximation introduced dose difference.

    Science.gov (United States)

    Zhang, Ray R; Feygelman, Vladimir; Harris, Eleanor R; Rao, Nikhil; Moros, Eduardo G; Zhang, Geoffrey G

    2013-01-07

    With CT-based Monte Carlo (MC) dose calculations, material composition is often assigned based on the standard Hounsfield unit ranges. This is known as the density threshold method. In bolus electron conformal therapy (BolusECT), the bolus material, machineable wax, would be assigned as soft tissue and the electron density is assumed equivalent to soft tissue based on its Hounsfield unit. This study investigates the dose errors introduced by this material assignment. BEAMnrc was used to simulate electron beams from a Trilogy accelerator. SPRRZnrc was used to calculate stopping power ratios (SPR) of tissue to wax, SPR (tissue) (wax), and tissue to water, SPR(tissue) (water), for 6, 9, 12, 15, and 18 MeV electron beams, of which 12 and 15MeV beams are the most commonly used energies in BolusECT. DOSXYZnrc was applied in dose distribution calculations in a tissue phantom with either flat wax slabs of various thicknesses or a wedge-shaped bolus on top. Dose distribution for two clinical cases, a chest wall and a head and neck, were compared with the bolus material treated as wax or tissue. The SPR(tissue) (wax) values for 12 and 15MeV beams are between 0.935 and 0.945, while the SPR(tissue) (water) values are between 0.990 and 0.991. For a 12 MeV beam, the dose in tissue immediately under the bolus is overestimated by 2.5% for a 3 cm bolus thickness if the wax bolus is treated as tissue. For 15 MeV beams, the error is 1.4%. However, in both clinical cases the differences in the PTV DVH is negligible. Due to stopping power differences, dose differences of up to 2.5% are observed in MC simulations if the bolus material is misassigned as tissue in BolusECT dose calculations. However, for boluses thinner than 2 cm that are more likely encountered in practice, the error is within clinical tolerance.

  1. Thermal Characterization of Molten Salt Systems

    Energy Technology Data Exchange (ETDEWEB)

    Toni Y. Gutknecht; Guy L. Fredrickson

    2011-09-01

    The phase stability of molten salts in an electrorefiner (ER) may be adversely affected by the buildup of sodium, fission products, and transuranics in the electrolyte. Potential situations that need to be avoided are the following: (1) salt freezing due to an unexpected change in the liquidus temperature, (2) phase separation or non-homogeneity of the molten salt due to the precipitation of solids or formation of immiscible liquids, and (3) any mechanism that can result in the separation and concentration of fissile elements from the molten salt. Any of these situations would result in an off-normal condition outside the established safety basis for electrorefiner (ER) operations. The stability (and homogeneity) of the phases can potentially be monitored through the thermal characterization of the salts, which can be a function of impurity concentration. This report describes the experimental results of typical salts compositions, which consist of chlorides of potassium, lithium, strontium, samarium, praseodymium, lanthanum, barium, cerium, cesium, neodymium, sodium and gadolinium chlorides as a surrogate for both uranium and plutonium, used for the processing of used nuclear fuels.

  2. Removal of Wax and Stickies from OCC by Flotation

    Energy Technology Data Exchange (ETDEWEB)

    M. R. Doshi; J. Dyer

    2000-01-31

    Laboratory research indicates that wax is amenable to removal by froth flotation provided it is free or detached from the fiber. The only effective means, at this time, of maximizing detachment of wax is through the use of low consistency pulping at temperatures above the melting point of wax. Wax removal from WCC through washing, flotation, or a combination of both was approximately 90% in these laboratory studies, indicating that not all of the wax is detached from fibers. These results were summarized in Annual Report 1, December 1, 1997 to November 30, 1998. Pilot trials were conducted in which the authors simulated a conventional OCC repulping process with and without flotation. Additional aggressive washing and water clarification were also examined during the study. The inclusion of flotation in the OCC stock preparation system significantly improved the removal of wax spots and extractable material from the furnish. Based on this study, the authors predict that a compact flotation system with 2 lb surfactant/ton of fiber would improve the OCC pulp quality with regard to wax spots by 60% and would not negatively affect strength properties. Flotation losses would be in the 2-5% range. Two mill trials were conducted during the last quarter of the project. One trial was carried out at Green Bay Packaging, Green Bay, WI, and a second trial was conducted at Menasha Corporation, Otsego, MI. A 250-liter Voith Sulzer Ecocell was used to evaluate the removal of wax and stickies from the OCC processing systems at these two mills. The inclusion of flotation in the OCC stock preparation system significantly improved the removal of wax spots from the furnish. The data indicate that flotation was more effective in removing wax and stickies than reverse cleaners. The mill trials have demonstrated that flotation can be substituted for or replace existing reverse cleaning systems and, in some cases, can replace dispersion systems. In this manner, the use of flotation can

  3. Self assembly of epicuticular waxes on living plant surfaces imaged by atomic force microscopy (AFM).

    Science.gov (United States)

    Koch, Kerstin; Neinhuis, Christoph; Ensikat, Hans-Jürgen; Barthlott, Wilhelm

    2004-03-01

    The cuticle of terrestrial vascular plants and some bryophytes is covered with a complex mixture of lipids, usually called epicuticular waxes. Self-assembly processes of wax molecules lead to crystalline three-dimensional micro- and nanostructures that emerge from an underlying wax film. This paper presents the first AFM study on wax regeneration on the surfaces of living plants and the very early stages of wax crystal formation at the molecular level. Wax formation was analysed on the leaves of Euphorbia lathyris, Galanthus nivalis, and Ipheion uniflorum. Immediately after wax removal, regeneration of a wax film began, consisting of individual layers of, typically, 3-5 nm thickness. Subsequently, several different stages of crystal growth could be distinguished, and different patterns of wax regeneration as well as considerable variation in regeneration speed were found.

  4. Conifer epicuticular wax as a biomarker of air pollution: an overview

    Directory of Open Access Journals (Sweden)

    Małgorzata Grodzińska-Jurczak

    2014-02-01

    Full Text Available Epicuticular wax covering the conifer tree species surface has been used, mainly in conifers, as a biomarker of air pollution damage. Using Scanning Electron Microscopy (SEM various alterations in wax structure and chemistry caused by natural and anthropogenic factors have been noticed. SEM enables to evaluate wax deterioration at a very early stage, before visible symptoms occur. Symptoms of wax injury are, in general, not specific to the air pollutant type. Most common alterations in wax were the following: an undeveloped structure, various type of wax tubes fusion or erosion (deformed and disfunctioned stomatal complexes, a decrease in wax tube distribution, increased enrichment of completely amorphous stage, shifted annual wax erosion rate, chemical and needle wettability changes. To use SEM as an accurate tool for evaluating wax alteration, it is essential to distinguish air pollution and natural factors from artefacts caused by inappropriate usage of technique.

  5. Supported Molten Metal Membranes for Hydrogen Separation

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Ravindra; Ma, Yi Hua; Yen, Pei-Shan; Deveau, Nicholas; Fishtik, Ilie; Mardilovich, Ivan

    2013-09-30

    We describe here our results on the feasibility of a novel dense metal membrane for hydrogen separation: Supported Molten Metal Membrane, or SMMM.1 The goal in this work was to develop these new membranes based on supporting thin films of low-melting, non- precious group metals, e.g., tin (Sn), indium (In), gallium (Ga), or their alloys, to provide a flux and selectivity of hydrogen that rivals the conventional but substantially more expensive palladium (Pd) or Pd alloy membranes, which are susceptible to poisoning by the many species in the coal-derived syngas, and further possess inadequate stability and limited operating temperature range. The novelty of the technology presented numerous challenges during the course of this project, however, mainly in the selection of appropriate supports, and in the fabrication of a stable membrane. While the wetting instability of the SMMM remains an issue, we did develop an adequate understanding of the interaction between molten metal films with porous supports that we were able to find appropriate supports. Thus, our preliminary results indicate that the Ga/SiC SMMM at 550 ºC has a permeance that is an order of magnitude higher than that of Pd, and exceeds the 2015 DOE target. To make practical SMM membranes, however, further improving the stability of the molten metal membrane is the next goal. For this, it is important to better understand the change in molten metal surface tension and contact angle as a function of temperature and gas-phase composition. A thermodynamic theory was, thus, developed, that is not only able to explain this change in the liquid-gas surface tension, but also the change in the solid-liquid surface tension as well as the contact angle. This fundamental understanding has allowed us to determine design characteristics to maintain stability in the face of changing gas composition. These designs are being developed. For further progress, it is also important to understand the nature of solution and

  6. Enhanced expression of EsWAX1 improves drought tolerance with increased accumulation of cuticular wax and ascorbic acid in transgenic Arabidopsis.

    Science.gov (United States)

    Zhu, Lin; Guo, Jiansheng; Zhu, Jian; Zhou, Cheng

    2014-02-01

    Drought can activate several stress responses in plants, such as stomatal closure, accumulation of cuticular wax and ascorbic acid (AsA), which have been correlated with improvement of drought tolerance. In this study, a novel MYB gene, designed as EsWAX1, was isolated and characterized from Eutrema salsugineum. EsWAX1 contained a full-length open reading frame (ORF) of 1068 bp, which encoding 355 amino acids. Transcript levels of EsWAX1 were quickly inducible by drought stress and ABA treatment, indicating that EsWAX1 may act as a positive regulator in response to drought stress. Ectopic expression of EsWAX1 increased accumulation of cuticular wax via modulating the expression of several wax-related genes, such as CER1, KCS2 and KCR1. Scanning electron microscopy further revealed higher densities of wax crystalline structures on the adaxial surfaces of leaves in transgenic Arabidopsis plants. In addition, the expression of several AsA biosynthetic genes (VTC1, GLDH and MIOX4) was significantly up-regulated in EsWAX1-overexpressing lines and these transgenic plants have approximately 23-27% more total AsA content than WT plants. However, the high-level expression of EsWAX1 severely disrupted plant normal growth and development. To reduce negative effects of EsWAX1 over-expression on plant growth, we generated transgenic Arabidopsis plants expressing EsWAX1 driven by the stress-inducible RD29A promoter. Our data indicated the RD29A::EsWAX1 transgenic plants had greater tolerance to drought stress than wild-type plants. Taken together, the EsWAX1 gene is a potential regulator that may be utilized to improve plant drought tolerance by genetic manipulation.

  7. Investigation of liquid wax components of Egyptian jojoba seeds.

    Science.gov (United States)

    El-Mallah, Mohammed Hassan; El-Shami, Safinaz Mohammed

    2009-01-01

    Egyptian jojoba seeds newly cultivated in Ismailia desert in Egypt promoted us to determine its lipid components. Fatty alcohols, fatty acids, wax esters and sterols patterns were determined by capillary GLC whereas, tocopherols profile, isopropenoid alcohols and sterylglycosides were determined by HPLC. The Egyptian seeds are rich in wax esters (55 %) with fatty alcohols C20:1 and C22:1 as major components and amounted to 43.0 % and 45.6 % respectively followed by C24:1 and C18:1(9.6 % and 1.3 % respectively). The fatty acids profile showed that C20:1 is the major constituent (60 %) followed by C18:1 and C22:1 (14.5 and 11.8 % respectively) whereas C24:1 was present at low concentration amounted to 1.6 %. In addition, the Egyptian jojoba wax contained C18:2 fatty acid at a level of 8.7 %. Wax esters composition showed that the local wax had C42 and C40 esters as major components amounted to 51.1 and 30.1 % respectively. Also, it had C44 and C38 at reasonable amounts (10.0 and 6.3 % respectively). Whereas C36 and C46 were present at lower concentrations amounted to 1.4 and 1.1 respectively. The sterols analysis showed the presence of campe-, stigma-, beta-sito-, and isofuco- sterol amounting to 18.4 %, 6.9 %, 68.7 %, and 6.0 % respectively. The tocopherols pattern revealed that the local seed wax contained gamma-tocopherol as major constituent (79.2 %) followed by alpha-tocopherol (20.3 %). beta-tocopherol as well as delta-tocopherol were found as minor constituents. The isopropenoid alcohols and the sterylglycosides (free and acylated) were not detected. The wax is proposed to be used in oleo chemistry and cosmetics.

  8. Conservação de goiabas tratadas com emulsões de cera de carnaúba Postharvest conservation of guavas through carnauba wax emulsion applications

    Directory of Open Access Journals (Sweden)

    Angelo Pedro Jacomino

    2003-12-01

    Full Text Available A goiaba é um fruto muito perecível. Assim, objetivou-se avaliar os efeitos de ceras à base de carnaúba na conservação pós-colheita de goiabas Pedro Sato sob condição ambiente. Utilizaram-se cinco ceras comerciais: Citrosol AK (18%, Citrosol M (10%, Fruit wax (18 a 21%, Meghwax ECF-100 (30% e Cleantex wax (18,5 a 20,5%, as quais foram aplicadas manualmente, na proporção de 0,15 a 0,20mL por fruta. Frutas sem aplicação de cera foram utilizadas como controle. O delineamento experimental foi inteiramente casualizado com 6 tratamentos, 4 repetições e 5 frutas por parcela. As goiabas foram caracterizadas imediatamente após a colheita e avaliadas aos 2, 4 e 6 dias após a aplicação dos tratamentos. As ceras exerceram pouca influência nos teores de sólidos solúveis totais, acidez total titulável e ácido ascórbico, porém, foram eficientes em retardar o amadurecimento, reduzir a perda de massa e a incidência de podridões. A cera Meghwax ECF-100 apresenta potencial para utilização em goiabas, porém há necessidade de ser avaliada em maior diluição, para evitar alterações indesejáveis.Guavas are very perishable fruits. Therefore, the objective of the present work was to evaluate the effects of several carnauba based waxes in the postharvest life of Pedro Sato guavas under room conditions. Five commercial waxes were used: Citrosol AK (18%, Citrosol M (10%, Fruit wax (18 a 21%, Meghwax ECF-100 (30% e Cleantex wax (18,5 a 20,5%. The waxes were applied manualy in the rate of 0.15 to 0.20mL of wax per fruit. Control fruits were not treated. The experiment was conducted in a completely randomized design with 6 treatments, 4 replicates per treatment and 5 fruits as experimental unit. Guavas were evaluated at harvest and at every 2 days until the 6th day after treatments. Waxing had little effect on total soluble solids, total titratable acidity and ascorbic acid contents. However, the waxes were efficient in delaying ripening

  9. Wax crystal-sparse leaf2, a rice homologue of WAX2/GL1, is involved in synthesis of leaf cuticular wax.

    Science.gov (United States)

    Mao, Bigang; Cheng, Zhijun; Lei, Cailin; Xu, Fenghua; Gao, Suwei; Ren, Yulong; Wang, Jiulin; Zhang, Xin; Wang, Jie; Wu, Fuqing; Guo, Xiuping; Liu, Xiaolu; Wu, Chuanyin; Wang, Haiyang; Wan, Jianmin

    2012-01-01

    Epicuticular wax in plants limits non-stomatal water loss, inhibits postgenital organ fusion, protects plants against damage from UV radiation and imposes a physical barrier against pathogen infection. Here, we give a detailed description of the genetic, physiological and morphological consequences of a mutation in the rice gene WSL2, based on a comparison between the wild-type and an EMS mutant. The mutant's leaf cuticle membrane is thicker and less organized than that of the wild type, and its total wax content is diminished by ~80%. The mutant is also more sensitive to drought stress. WSL2 was isolated by positional cloning, and was shown to encode a homologue of the Arabidopsis thaliana genes CER3/WAX2/YRE/FLP1 and the maize gene GL1. It is expressed throughout the plant, except in the root. A transient assay carried out in both A. thaliana and rice protoplasts showed that the gene product is deposited in the endoplasmic reticulum. An analysis of the overall composition of the wax revealed that the mutant produces a substantially reduced quantity of C22-C32 fatty acids, which suggests that the function of WSL2 is associated with the elongation of very long-chain fatty acids.

  10. An Assessment of Molten Metal Detachment Hazards During Electron Beam Welding in Space

    Science.gov (United States)

    Fragomeni, James M.; Nunes, Arthur C., Jr.

    1998-01-01

    The safety issue has been raised with regards to potential molten metal detachments from the weld pool and cold filler wire during electron beam welding in space. This investigation was undertaken to evaluate if molten metal could detach and come in contact with astronauts and burn through the fabric of the astronauts' Extravehicular Mobility Unit (EMU) during electron beam welding in space. Molten metal detachments from either the weld/cut substrate or weld wire could present harm to a astronaut if the detachment was to burn through the fabric of the EMU. Theoretical models were developed to predict the possibility and size of the molten metal detachment hazards during the electron beam welding exercises at Low Earth Orbit (LEO). The primary molten metal detachment concerns were those cases of molten metal separation from the metal surface due to metal cutting, weld pool splashing, entrainment and release of molten metal due to filler wire snap-out from the weld puddle, and molten metal accumulation and release from the end of the weld wire. Some possible ways of obtaining molten metal drop detachments would include an impulse force, or bump, to the weld sample, cut surface, or filler wire. Theoretical models were developed for these detachment concerns from principles of impact and kinetic energies, surface tension, drop geometry, surface energies, and particle dynamics. The surface tension represents the force opposing the liquid metal drop from detaching whereas the weight of the liquid metal droplet represents a force that is tending to detach the molten metal drop. Theoretical calculations have indicated that only a small amount of energy is required to detach a liquid metal drop; however, much of the energy of an impact is absorbed in the sample or weld plate before it reaches the metal drop on the cut edge or surface. The tendency for detachment is directly proportional to the weld pool radius and metal density and inversely proportional to the surface

  11. Crust formation and its effect on the molten pool coolability

    Energy Technology Data Exchange (ETDEWEB)

    Park, R.J.; Lee, S.J.; Sim, S.K. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-09-01

    Experimental and analytical studies of the crust formation and its effect on the molten pool coolability have been performed to examine the crust formation process as a function of boundary temperatures as well as to investigate heat transfer characteristics between molten pool and overlying water in order to evaluate coolability of the molten pool. The experimental test results have shown that the surface temperature of the bottom plate is a dominant parameter in the crust formation process of the molten pool. It is also found that the crust thickness of the case with direct coolant injection into the molten pool is greater than that of the case with a heat exchanger. Increasing mass flow rate of direct coolant injection to the molten pool does not affect the temperature of molten pool after the crust has been formed in the molten pool because the crust behaves as a thermal barrier. The Nusselt number between the molten pool and the coolant of the case with no crust formation is greater than that of the case with crust formation. The results of FLOW-3D analyses have shown that the temperature distribution contributes to the crust formation process due to Rayleigh-Benard natural convection flow.

  12. Laboratory Deposition Apparatus to Study the Effects of Wax Deposition on Pipe Magnetic Field Leakage Signals

    Directory of Open Access Journals (Sweden)

    Karim Mohd Fauzi Abd

    2014-07-01

    Full Text Available Accurate technique for wax deposition detection and severity measurement on cold pipe wall is important for pipeline cleaning program. Usually these techniques are validated by conventional techniques on laboratory scale wax deposition flow loop. However conventional techniques inherent limitations and it is difficult to reproduce a predetermine wax deposit profile and hardness at designated location in flow loop. An alternative wax deposition system which integrates modified pour casting method and cold finger method is presented. This system is suitable to reproduce high volume of medium hard wax deposit in pipe with better control of wax deposit profile and hardness.

  13. [Flow of molten metal in denture base in horizontal centrifugal casting procedure. (Part 2) Flow, inflow volume and casting time of molten metal passing through several sprues into model denture plate mold (author's transl)].

    Science.gov (United States)

    Okamura, H

    1978-10-01

    Two types of spruing methods were used in the casting of the denture type model pattern (thickness, 0.43 mm). Flow of molten metal in the mold was filmed by the improved system of Part 1. When three sprues were attached to the pattern vertically, molten metal passed through each sprue gate flowed being affected by the direction of gravity and revolution of casting machine, and gathered at the lower part of the mold. Next molten metal filled the mold from the lower part to the upper part. In this spruing type, molten metal turned its direction of flow several times. At the middle stage of casting, the inflow volume per unit time (inflow rate), v (mm3/10-2)s)was evaluated as v = 12.36 + 5.16A-0.16 A2 (A: total cross-sectional areas of sprues). The inflow rate increased with increase of the area of the sprues, but it saturated. When the main sprue and the subsprues were attached at the posterior border, the molten metal filled the mold from the lower part to the upper part quietly. In this spruing type, the casting mold was set facing its sprue gates downwards. The inflow rate at the middle stage of casting was evaluated as v = 21.05 + 1.79 C (C: the cross-sectional area of the main sprue). The inflow rate increased linearly with increase of the area of the main sprue.

  14. Genetic control of cuticular wax compounds in Eucalyptus globulus.

    Science.gov (United States)

    Gosney, Benjamin J; Potts, Brad M; O'Reilly-Wapstra, Julianne M; Vaillancourt, René E; Fitzgerald, Hugh; Davies, Noel W; Freeman, Jules S

    2016-01-01

    Plant cuticular wax compounds perform functions that are essential for the survival of terrestrial plants. Despite their importance, the genetic control of these compounds is poorly understood outside of model taxa. Here we investigate the genetic basis of variation in cuticular compounds in Eucalyptus globulus using quantitative genetic and quantitative trait loci (QTL) analyses. Quantitative genetic analysis was conducted using 246 open-pollinated progeny from 13 native sub-races throughout the geographic range. QTL analysis was conducted using 112 clonally replicated progeny from an outcross F2 population. Nine compounds exhibited significant genetic variation among sub-races with three exhibiting signals of diversifying selection. Fifty-two QTL were found with co-location of QTL for related compounds commonly observed. Notable among these was the QTL for five wax esters, which co-located with a gene from the KCS family, previously implicated in the biosynthesis of cuticular waxes in Arabidopsis. In combination, the QTL and quantitative genetic analyses suggest the variation and differentiation in cuticular wax compounds within E. globulus has a complex genetic origin. Sub-races exhibited independent latitudinal and longitudinal differentiation in cuticular wax compounds, likely reflecting processes such as historic gene flow and diversifying selection acting upon genes that have diverse functions in distinct biochemical pathways.

  15. Electrochemical studies on plutonium in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Bourges, G. [CEA-Centre d' etudes de Valduc, 21 120 Is sur Tille (France)], E-mail: gilles.bourges@cea.fr; Lambertin, D.; Rochefort, S. [CEA-Centre d' etudes de Valduc, 21 120 Is sur Tille (France); Delpech, S.; Picard, G. [Laboratoire d' Electrochimie et de Chimie Analytique (UMR7575, CNRS), ENSCP, 11 rue Pierre et Marie Curie, 75231 Paris (France)

    2007-10-11

    Electrochemical studies on plutonium have been supporting the development of pyrochemical processes involving plutonium at CEA. The electrochemical properties of plutonium have been studied in molten salts - ternary eutectic mixture NaCl-KCl-BaCl{sub 2}, equimolar mixture NaCl-KCl and pure CaCl{sub 2} - and in liquid gallium at 1073 K. The formal, or apparent, standard potential of Pu(III)/Pu redox couple in eutectic mixture of NaCl-KCl-BaCl{sub 2} at 1073 K determined by potentiometry is equal to -2.56 V (versus Cl{sub 2}, 1 atm/Cl{sup -} reference electrode). In NaCl-KCl eutectic mixture and in pure CaCl{sub 2} the formal standard potentials deduced from cyclic voltammetry are respectively -2.54 V and -2.51 V. These potentials led to the calculation of the activity coefficients of Pu(III) in the molten salts. Chronoamperometry on plutonium in liquid gallium using molten chlorides - CaCl{sub 2} and equimolar NaCl/KCl - led to the determination of the activity coefficient of Pu in liquid Ga, log {gamma} = -7.3. This new data is a key parameter to assess the thermodynamic feasibility of a process using gallium as solvent metal. By comparing gallium with other solvent metals - cadmium, bismuth, aluminum - gallium appears to be, with aluminum, more favorable for the selectivity of the separation at 1073 K of plutonium from cerium. In fact, compared with a solid tungsten electrode, none of these solvent liquid metals is a real asset for the selectivity of the separation. The role of a solvent liquid metal is mainly to trap the elements.

  16. Apparatus for controlling molten core debris. [LMFBR

    Science.gov (United States)

    Golden, M.P.; Tilbrook, R.W.; Heylmun, N.F.

    1977-07-19

    Disclosed is an apparatus for containing, cooling, diluting, dispersing and maintaining subcritical the molten core debris assumed to melt through the bottom of a nuclear reactor pressure vessel in the unlikely event of a core meltdown. The apparatus is basically a sacrificial bed system which includes an inverted conical funnel, a core debris receptacle including a spherical dome, a spherically layered bed of primarily magnesia bricks, a cooling system of zig-zag piping in graphite blocks about and below the bed and a cylindrical liner surrounding the graphite blocks including a steel shell surrounded by firebrick. Tantalum absorber rods are used in the receptacle and bed. 9 claims, 22 figures.

  17. Fungal contamination of paraffin wax blocks in a pathology archive.

    Science.gov (United States)

    Müller, K; Ellenberger, C; Aupperle, H; Schmäschke, R; Scheller, R; Wittenbrink, M M; Schoon, H-A

    2011-01-01

    While searching for paraffin wax blocks for research purposes in our archive we detected numerous larval and some dead adult moths. Some wax blocks were riddled with a white-brown crumbling substance. The entire archive was checked and profoundly-infested blocks were separated from unaffected blocks. Mycological and parasitological investigations were performed. Fungi were identified by culture and polymerase chain reaction, which revealed high sequence homology to six different fungal species. The moths were determined to be Nemapogon personellus. A total of 8,484 wax blocks had to be removed from the archive and destroyed. Pathologists should be alerted to the importance of checking the humidity of the air where archival material is stored.

  18. Unheimlich. From Wax Figures to the Uncanny Valley

    Directory of Open Access Journals (Sweden)

    Pietro Conte

    2012-01-01

    Full Text Available In his pioneering History of Portraiture in Wax, Julius von Schlosser traced back the age-old history of a material which at that time seemed to be already antiquated, if not obsolete. Wax sculptures were rejected and ousted from art history because of their excessive similarity and adherence to models. One hundred years later, however, hyperrealism got its revenge with Maurizio Cattelan’s celebrated hanging children. Moving from that controversial artwork and focusing on the heated polemics over it, my paper will address the question of the well-known Unheimlichkeit of wax figures, investigated by Ernst Jentsch and Sigmund Freud in the early Twentieth Century and nowadays becoming increasingly topical thanks to the recent debate about the existence and nature of the so called Uncanny Valley.

  19. Thermal-hydraulics of internally heated molten salts and application to the Molten Salt Fast Reactor

    Science.gov (United States)

    Fiorina, Carlo; Cammi, Antonio; Luzzi, Lelio; Mikityuk, Konstantin; Ninokata, Hisashi; Ricotti, Marco E.

    2014-04-01

    The Molten Salt Reactors (MSR) are an innovative kind of nuclear reactors and are presently considered in the framework of the Generation IV International Forum (GIF-IV) for their promising performances in terms of low resource utilization, waste minimization and enhanced safety. A unique feature of MSRs is that molten fluoride salts play the distinctive role of both fuel (heat source) and coolant. The presence of an internal heat generation perturbs the temperature field and consequences are to be expected on the heat transfer characteristics of the molten salts. In this paper, the problem of heat transfer for internally heated fluids in a straight circular channel is first faced on a theoretical ground. The effect of internal heat generation is demonstrated to be described by a corrective factor applied to traditional correlations for the Nusselt number. It is shown that the corrective factor can be fully characterized by making explicit the dependency on Reynolds and Prandtl numbers. On this basis, a preliminary correlation is proposed for the case of molten fluoride salts by interpolating the results provided by an analytic approach previously developed at the Politecnico di Milano. The experimental facility and the related measuring procedure for testing the proposed correlation are then presented. Finally, the developed correlation is used to carry out a parametric investigation on the effect of internal heat generation on the main out-of-core components of the Molten Salt Fast Reactor (MSFR), the reference circulating-fuel MSR design in the GIF-IV. The volumetric power determines higher temperatures at the channel wall, but the effect is significant only in case of large diameters and/or low velocities.

  20. Some Thermal and Electrical Properties of Candelilla Wax

    OpenAIRE

    2002-01-01

    We report the values of some thermal and electrical properties of Candelilla Wax (euphorbia cerifera). The open-cell photoacoustic technique and another photothermic technique - based on the measure of the temperature decay of a heated sample - were employed to obtain the thermal diffusivity ($\\alpha_{s} = 0.026 \\pm 0.00095 {cm}^{2}{/sec}$) as well as the thermal conductivity ($k=2.132 \\pm 0.16 {W/mK}$) of this wax. The Kelvin null method was used to measure the dark decay of the surface pote...

  1. The Behavior of Some Waxes in Composition B

    Science.gov (United States)

    1978-12-01

    beeswax 14 10 Bareco X-715 Lot C-652 15 K 11 Bareco X-404 Batch B-610 16 12 Bareco X-718 Lot C-649 17 13 Bareco X-719 Batch 658 18 14 Bareco X-717 Lot C-655...influenced both these parameters satis- factorily. An acceptable mixture was attributed to an effective wax coating of the surface of the RDX...temperatures prior to casting. Then, the stability of adhesion of the wax coating on RDX during and after casting op- erations must be examined closely

  2. Applications of micro-SAXS/WAXS to study polymer fibers

    Energy Technology Data Exchange (ETDEWEB)

    Riekel, C. E-mail: riekel@esrf.fr

    2003-01-01

    Instrumentation and selected applications for X-ray microdiffraction experiments on polymer and biopolymer fibers at the European Synchrotron Radiation Facility (ESRF) microfocus beamline are reviewed. Combined SAXS/WAXS experiments can be performed on single fibers with a beam size down to about 5 {mu}m. WAXS experiments can be performed down to about 2 {mu}m and in exceptional cases down to 0.1 {mu}m beam size. The instrumental possibilities are demonstrated for the production line of spider silk.

  3. Cannabis-induced psychosis associated with high potency "wax dabs".

    Science.gov (United States)

    Pierre, Joseph M; Gandal, Michael; Son, Maya

    2016-04-01

    With mounting evidence that the risk of cannabis-induced psychosis may be related to both dose and potency of tetrahydrocannbinol (THC), increasing reports of psychosis associated with cannabinoids containing greater amounts of THC are anticipated. We report two cases of emergent psychosis after using a concentrated THC extract known as cannabis "wax," "oil," or "dabs" raising serious concerns about its psychotic liability. Although "dabbing" with cannabis wax is becoming increasingly popular in the US for both recreational and "medicinal" intentions, our cases raise serious concerns about its psychotic liability and highlight the importance of understanding this risk by physicians recommending cannabinoids for purported medicinal purposes. Published by Elsevier B.V.

  4. Production of Oxygen from Lunar Regolith using Molten Oxide Electrolysis

    Science.gov (United States)

    Sibille, Laurent; Sadoway, Donald R.; Sirk, Aislinn; Tripathy, Prabhat; Melendez, Orlando; Standish, Evan; Dominquez, Jesus A.; Stefanescu, Doru M.; Curreri, Peter A.; Poizeau, Sophie

    2009-01-01

    This slide presentation reviews the possible use of molten oxide electrolysis to extract oxygen from the Lunar Regolith. The presentation asserts that molten regolith electrolysis has advanced to be a useful method for production of oxygen and metals in situ on the Moon. The work has demonstrated an 8 hour batch of electrolysis at 5 amps using Iridium inert anodes.

  5. Design considerations for concentrating solar power tower systems employing molten salt.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Robert Charles; Siegel, Nathan Phillip; Kolb, Gregory J.; Vernon, Milton E.; Ho, Clifford Kuofei

    2010-09-01

    The Solar Two Project was a United States Department of Energy sponsored project operated from 1996 to 1999 to demonstrate the coupling of a solar power tower with a molten nitrate salt as a heat transfer media and for thermal storage. Over all, the Solar Two Project was very successful; however many operational challenges were encountered. In this work, the major problems encountered in operation of the Solar Two facility were evaluated and alternative technologies identified for use in a future solar power tower operating with a steam Rankine power cycle. Many of the major problems encountered can be addressed with new technologies that were not available a decade ago. These new technologies include better thermal insulation, analytical equipment, pumps and values specifically designed for molten nitrate salts, and gaskets resistant to thermal cycling and advanced equipment designs.

  6. Production and release of ISOL beams from molten fluoride salt targets

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, T.M., E-mail: taniamel@mail.cern.ch [IFIMUP and IN – Institut of Nanosciences and Nanotechnologies, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); European Organization for Nuclear Research – CERN, 1211 Geneva 23 (Switzerland); Hodak, R. [Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, SK-842 15 Bratislava (Slovakia); Ghetta, V.; Allibert, M.; Heuer, D. [Laboratoire de Physique Subatomique et de Cosmologie – LPSC, 53 Rue des Martyrs, 38026 Grenoble Cedex (France); Noah, E. [Section de Physique, Université de Genève, 1211 Genève 4 (Switzerland); Cimmino, S. [European Organization for Nuclear Research – CERN, 1211 Geneva 23 (Switzerland); Delonca, M. [European Organization for Nuclear Research – CERN, 1211 Geneva 23 (Switzerland); IRTES-M3M, Université de Technologie de Belfort-Montbeliard, 90010 Belfort Cedex (France); IRTES-LERMPS, Université de Technologie de Belfort-Montbeliard, 90010 Belfort Cedex (France); Gottberg, A. [European Organization for Nuclear Research – CERN, 1211 Geneva 23 (Switzerland); Instituto de Estructura de la Materia CSIC, E28006 Madrid (Spain); Kronberger, M. [European Organization for Nuclear Research – CERN, 1211 Geneva 23 (Switzerland); Department of Physics, University of Jyväskylä, Survontie 9, Jyväskylä FI-40014 (Finland); Ramos, J.P. [European Organization for Nuclear Research – CERN, 1211 Geneva 23 (Switzerland); Department of Materials and Ceramics Engineering, University of Aveiro, CICECO, 3810-193 Aveiro (Portugal); and others

    2014-06-01

    In the framework of the Beta Beams project, a molten fluoride target has been proposed for the production of the required 10{sup 1318}Ne/s. The production and extraction of such rates are predicted to be possible on a circulating molten salt with 160 MeV proton beams at close to 1 MW power. As a most important step to validate the concept, a prototype has been designed and investigated at CERN-ISOLDE using a static target unit. The target material consisted of a binary fluoride system, NaF:LiF (39:61 mol.%), with melting point at 649 °C. The production of Ne beams has been monitored as a function of the target temperature and proton beam intensity. The prototype development and the results of the first online tests with 1.4 GeV proton beam are presented in this paper.

  7. Production and Release of ISOL Beams from Molten Fluoride Salt Targets

    CERN Document Server

    Mendonca, T M; Ghetta, V; Alibert, M; Heuer, D; Noah, E; Cimmino, S; Delonca, M; Gottberg, A; Kronberger, M; Ramos, J; Seiffert, C; Stora, T; CERN. Geneva. ATS Department

    2014-01-01

    In the framework of the Beta Beams study, a molten fluoride target has been proposed for the production of the required 1013 18Ne/s. The production and extraction of such rates are obtained on a circulating molten salt with proton beam energy beams at close to 1 MW power. As a most important step to validate the concept, a prototype has been designed and investigated at CERN-ISOLDE using a static target unit. The target material consisted of a binary fluoride system, NaF:LiF (39:61 % mol.), with melting point at 649ºC. The production of Ne beams has been monitored as a function of the target temperature and proton beam intensity. The prototype development and the results of the first online tests with 1.4 GeV proton beam are presented in this paper.

  8. Recent advances in the molten salt technology for the destruction of energetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Upadhye, R.S.; Watkins, B.E.; Pruneda, C.O.

    1995-11-01

    The DOE has thousands of pounds of energetic materials which result from dismantlement operations at the Pantex Plant. The authors have demonstrated the Molten Salt Destruction (MSD) Process for the treatment of explosives and explosive-containing wastes on a 1.5 kilogram of explosive per hour scale and are currently building a 5 kilogram per hour unit. MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen and water. Any inorganic constituents of the waste, such as binders and metallic particles, are retained in the molten salt. The destruction of energetic material waste is accomplished by introducing it, together with air, into a crucible containing a molten salt, in this case a eutectic mixture of Na, K, and Li carbonates. The following pure component DOE and DoD explosives have been destroyed in LLNL`s experimental unit at their High Explosives Applications Facility (HEAF): ammonium picrate, HMX, K-6, NQ, NTO, PETN, RDX, TATB, and TNT. In addition, the following formulations were also destroyed: Comp B, LX-10, LX-16, LX-17, PBX-9404, and XM46, a US Army liquid gun propellant. In this 1.5 kg/hr unit, the fractions of carbon converted to CO and of chemically bound nitrogen converted to NOx were found to be well below 1T. In addition to destroying explosive powders and molding powders the authors have also destroyed materials that are typical of real world wastes. These include shavings from machined pressed parts of plastic bonded explosives and sump waste containing both explosives and non-explosive debris. Based on the information obtained on the smaller unit, the authors have constructed a 5 kg/hr MSD unit, incorporating LLNL`s advanced chimney design. This unit is currently under shakedown tests and evaluation.

  9. Clinically based diagnostic wax-up for optimal esthetics: the diagnostic mock-up.

    Science.gov (United States)

    Simon, Harel; Magne, Pascal

    2008-05-01

    A diagnostic wax-up can enhance the predictability of treatment by modeling the desired result in wax prior to treatment. It is critical to correlate the wax-up to the patient to avoid a result that appears optimal on the casts but does not correspond to the patient's smile. This article reviews the applications and techniques for clinically based diagnostic wax-up, and focuses on the diagnostic mock-up philosophy as a means to obtain predictable esthetics and function.

  10. Rheological profiling of organogels prepared at critical gelling concentrations of natural waxes in a triacylglycerol solvent

    OpenAIRE

    Patel, Ashok; Babaahmadifooladi, Mehrnoosh; Lesaffer, Ans; Dewettinck, Koen

    2015-01-01

    The aim of this study was to use a detailed rheological characterization to gain new insights into the gelation behavior of natural waxes. To make a comprehensive case, six natural waxes (differing in the relative proportion of chemical components: hydrocarbons, fatty alcohols, fatty acids, and wax esters) were selected as organogelators to gel high-oleic sunflower oil. Flow and dynamic rheological properties of organogels prepared at critical gelling concentrations (Cg) of waxes were studied...

  11. Wetting effects of surface treatments on inlay wax-investment combinations.

    Science.gov (United States)

    Morrison, J T; Duncanson, M G; Shillingburg, H T

    1981-11-01

    Gypsum-bonded and phosphate-bonded investments were applied to wax surfaces which were untreated, treated by buffing with cotton moistened with a die lubricant containing organic solvent, or treatment with a wax pattern cleaner. Contact angles between the investment material and wax surfaces were measured and compared. The treatment of a wax pattern with a surface tension reducing agent significantly increases the degree of wetting by both gypsum- and phosphate-bonded investments.

  12. The analysis of the possibility of the application of the casting waxes in the process RP

    OpenAIRE

    G. Budzik

    2009-01-01

    The article presents analysis of possibility of application of casting waxes in process of rapid prototyping of casting models in silicone the matrices. The researches were made on casting waxes applied to the manufacturing of precise casting models and also the model system. Testing waxes are intended nominally to the processing in process of the injection. The determining of possibility processing of waxes in silicone forms was purpose of researches. Researches concerned of whole manufactur...

  13. Stable colloids in molten inorganic salts.

    Science.gov (United States)

    Zhang, Hao; Dasbiswas, Kinjal; Ludwig, Nicholas B; Han, Gang; Lee, Byeongdu; Vaikuntanathan, Suri; Talapin, Dmitri V

    2017-02-15

    A colloidal solution is a homogeneous dispersion of particles or droplets of one phase (solute) in a second, typically liquid, phase (solvent). Colloids are ubiquitous in biological, chemical and technological processes, homogenizing highly dissimilar constituents. To stabilize a colloidal system against coalescence and aggregation, the surface of each solute particle is engineered to impose repulsive forces strong enough to overpower van der Waals attraction and keep the particles separated from each other. Electrostatic stabilization of charged solutes works well in solvents with high dielectric constants, such as water (dielectric constant of 80). In contrast, colloidal stabilization in solvents with low polarity, such as hexane (dielectric constant of about 2), can be achieved by decorating the surface of each particle of the solute with molecules (surfactants) containing flexible, brush-like chains. Here we report a class of colloidal systems in which solute particles (including metals, semiconductors and magnetic materials) form stable colloids in various molten inorganic salts. The stability of such colloids cannot be explained by traditional electrostatic and steric mechanisms. Screening of many solute-solvent combinations shows that colloidal stability can be traced to the strength of chemical bonding at the solute-solvent interface. Theoretical analysis and molecular dynamics modelling suggest that a layer of surface-bound solvent ions produces long-ranged charge-density oscillations in the molten salt around solute particles, preventing their aggregation. Colloids composed of inorganic particles in inorganic melts offer opportunities for introducing colloidal techniques to solid-state science and engineering applications.

  14. Transient simulation of molten salt central receiver

    Science.gov (United States)

    Doupis, Dimitri; Wang, Chuan; Carcorze-Soto, Jorge; Chen, Yen-Ming; Maggi, Andrea; Losito, Matteo; Clark, Michael

    2016-05-01

    Alstom is developing concentrated solar power (CSP) utilizing 60/40wt% NaNO3-KNO3 molten salt as the working fluid in a tower receiver for the global renewable energy market. In the CSP power generation cycle, receivers undergo a daily cyclic operation due to the transient nature of solar energy. Development of robust and efficient start-up and shut-down procedures is critical to avoiding component failures due to mechanical fatigue resulting from thermal transients, thus maintaining the performance and availability of the CSP plant. The Molten Salt Central Receiver (MSCR) is subject to thermal transients during normal daily operation, a cycle that includes warmup, filling, operation, draining, and shutdown. This paper describes a study to leverage dynamic simulation and finite element analysis (FEA) in development of start-up, shutdown, and transient operation concepts for the MSCR. The results of the FEA also verify the robustness of the MSCR design to the thermal transients anticipated during the operation of the plant.

  15. Stable colloids in molten inorganic salts

    Science.gov (United States)

    Zhang, Hao; Dasbiswas, Kinjal; Ludwig, Nicholas B.; Han, Gang; Lee, Byeongdu; Vaikuntanathan, Suri; Talapin, Dmitri V.

    2017-02-01

    A colloidal solution is a homogeneous dispersion of particles or droplets of one phase (solute) in a second, typically liquid, phase (solvent). Colloids are ubiquitous in biological, chemical and technological processes, homogenizing highly dissimilar constituents. To stabilize a colloidal system against coalescence and aggregation, the surface of each solute particle is engineered to impose repulsive forces strong enough to overpower van der Waals attraction and keep the particles separated from each other. Electrostatic stabilization of charged solutes works well in solvents with high dielectric constants, such as water (dielectric constant of 80). In contrast, colloidal stabilization in solvents with low polarity, such as hexane (dielectric constant of about 2), can be achieved by decorating the surface of each particle of the solute with molecules (surfactants) containing flexible, brush-like chains. Here we report a class of colloidal systems in which solute particles (including metals, semiconductors and magnetic materials) form stable colloids in various molten inorganic salts. The stability of such colloids cannot be explained by traditional electrostatic and steric mechanisms. Screening of many solute–solvent combinations shows that colloidal stability can be traced to the strength of chemical bonding at the solute–solvent interface. Theoretical analysis and molecular dynamics modelling suggest that a layer of surface-bound solvent ions produces long-ranged charge-density oscillations in the molten salt around solute particles, preventing their aggregation. Colloids composed of inorganic particles in inorganic melts offer opportunities for introducing colloidal techniques to solid-state science and engineering applications.

  16. Measurement and analyses of molten Ni-Co alloy density

    Institute of Scientific and Technical Information of China (English)

    XIAO Feng; K. MUKAI; FANG Liang; FU Ya; YANG Ren-hui

    2006-01-01

    With the advent of powerful mathematical modeling techniques for material phenomena, there is renewed interest in reliable data for the density of the Ni-based superalloys. Up to now, there has been few report on the density of molten Ni-Co alloy.In order to obtain more accurate density data for molten Ni-Co alloy, the density of molten Ni-Co alloy was measured with a modified sessile drop method, and the accommodation of different atoms in molten Ni-Co alloy was analyzed. The density of alloy is found to decrease with increasing temperature and Co concentration in the alloy. The molar volume of molten Ni-Co alloy increases with increasing Co concentration. The molar volume of Ni-Co alloy determined shows a positive deviation from the linear molar volume, and the deviation of molar volume from ideal mixing increases with increasing Co concentration over the experimental concentration range.

  17. Developing Status of Waxes for Leather%皮革用蜡发展现状

    Institute of Scientific and Technical Information of China (English)

    张建雨; 满杰; 冯跃跃; 杨顺立; 冯强; 阚冬梅

    2011-01-01

    The current developing situation of the waxes for leather both at home and abroad is introduced in this paper.The applications of synthetic wax, chloridized paraffin, emulsifying wax and micro-powder wax, etc.for leather are introduced.Many kinds of waxes for leather were analyzed in the current production situation and properties, such as the pull-up wax, white smog wax, charring wax, handle wax, luster wax, filling wax, and so on.And at the same time the suggestion about the domestic development of leather wax were pointed out.%本文综述了国内外皮革用蜡的发展现状.介绍了合成酯蜡、氯化石蜡、乳化蜡、微粉蜡等在皮革中的应用.分析了皮革变色蜡、皮革白雾蜡、皮革烧焦蜡、皮革手感蜡、皮革上光蜡、皮革填充蜡等皮革用蜡的生产现状及性能特点,并对我国发展皮革用蜡提出了几点意见.

  18. Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

    2007-08-16

    Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

  19. Casting Apparatus Including A Gas Driven Molten Metal Injector And Method

    Energy Technology Data Exchange (ETDEWEB)

    Trudel, David R. (Westlake, OH); Meyer, Thomas N. (Murrysville, PA); Kinosz, Michael J. (Apollo, PA); Arnaud, Guy (Morin Heights, CA); Bigler, Nicolas (Riviere-Beaudette, CA)

    2003-06-17

    The filtering molten metal injector system includes a holder furnace, a casting mold supported above the holder furnace, and at least one molten metal injector supported from a bottom side of the casting mold. The holder furnace contains a supply of molten metal. The mold defines a mold cavity for receiving the molten metal from the holder furnace. The molten metal injector projects into the holder furnace. The molten metal injector includes a cylinder defining a piston cavity housing a reciprocating piston for pumping the molten metal upward from the holder furnace to the mold cavity. The cylinder and piston are at least partially submerged in the molten metal when the holder furnace contains the molten metal. The cylinder or the piston includes a molten metal intake for receiving the molten metal into the piston cavity when the holder furnace contains molten metal. A conduit connects the piston cavity to the mold cavity. A molten metal filter is located in the conduit for filtering the molten metal passing through the conduit during the reciprocating movement of the piston. The molten metal intake may be a valve connected to the cylinder, a gap formed between the piston and an open end of the cylinder, an aperture defined in the sidewall of the cylinder, or a ball check valve incorporated into the piston. A second molten metal filter preferably covers the molten metal intake to the injector.

  20. EPICUTICULAR WAX COMPOSITION OF SOME EUROPEAN SEDUM SPECIES

    NARCIS (Netherlands)

    STEVENS, JF; THART, H; BOLCK, A; ZWAVING, JH; MALINGRE, TM

    1994-01-01

    Epicuticular waxes from 30 species of Sedum and 2 species of Sempervivoideae, i.e. Aeonium spathulatum and Sempervivum nevadense, have been analysed by GC and GC-MS. The Sedum taxa examined were S. acre, S. album, S. series Alpestria (13 species), S. anglicum, S. brevifolium, S. litoreum, S. lydium,

  1. Release Characteristics of Diltiazem Hydrochloride Wax-Matrix ...

    African Journals Online (AJOL)

    Michael Horsfall

    diltiazem hydrochloride-wax matrix granules with sintering. ... The drug release was by Higuchi controlled diffusion mechanism and it followed ... of plastic matrix tablets. Polymer films with different permeability have been .... More so, with increase in temperature and ..... characterization of ibuprofen-cetyl alcohol beads by.

  2. Uncovered secret of a Vasseur-Tramond wax model.

    Science.gov (United States)

    Pastor, J F; Gutiérrez, B; Montes, J M; Ballestriero, R

    2016-01-01

    The technique of anatomical wax modelling reached its heyday in Italy during the 18th century, through a fruitful collaboration between sculptors and anatomists. It soon spread to other countries, and prestigious schools were created in England, France, Spain and Austria. Paris subsequently replaced Italy as the major centre of manufacture, and anatomical waxes were created there from the mid-19th century in workshops such as that of Vasseur-Tramond. This workshop began to sell waxes to European Faculties of Medicine and Schools of Surgery around 1880. Little is known of the technique employed in the creation of such artefacts as this was deemed a professional secret. To gain some insight into the methods of construction, we have studied a Vasseur-Tramond wax model in the Valladolid University Anatomy Museum, Spain, by means of multi-slice computerised tomography and X-ray analysis by means of environmental scanning electron microscopy. Scanning electron microscopy was used to examine the hair. These results have revealed some of the methods used to make these anatomical models and the materials employed.

  3. 75 FR 80843 - Petroleum Wax Candles From China

    Science.gov (United States)

    2010-12-23

    ....2(f)). Background The Commission instituted this review on July 1, 2010 (75 FR 38121) and determined on October 4, 2010 that it would conduct an expedited review (75 FR 63200, October 14, 2010). The... COMMISSION Petroleum Wax Candles From China Determination On the basis of the record \\1\\ developed in...

  4. Characterization of Epoxy Composites Reinforced with Wax Encapsulated Microcrystalline Cellulose

    Directory of Open Access Journals (Sweden)

    Yuanfeng Pan

    2016-11-01

    Full Text Available The effect of paraffin wax encapsulated microcrystalline cellulose (EMC particles on the mechanical and physical properties of EMC/epoxy composites were investigated. It was demonstrated that the compatibility between cellulose and epoxy resin could be maintained due to partial encapsulation resulting in an improvement in epoxy composite mechanical properties. This work was unique because it was possible to improve the physical and mechanical properties of the EMC/epoxy composites while encapsulating the microcrystalline cellulose (MCC for a more homogeneous dispersion. The addition of EMC could increase the stiffness of epoxy composites, especially when the composites were wet. The 1% EMC loading with a 1:2 ratio of wax:MCC demonstrated the best reinforcement for both dry and wet properties. The decomposition temperature of epoxy was preserved up to a 5% EMC loading and for different wax:MCC ratios. An increase in wax encapsulated cellulose loading did increase water absorption but overall this absorption was still low (<1% for all composites.

  5. Wax Precipitation Modeled with Many Mixed Solid Phases

    DEFF Research Database (Denmark)

    Heidemann, Robert A.; Madsen, Jesper; Stenby, Erling Halfdan

    2005-01-01

    The behavior of the Coutinho UNIQUAC model for solid wax phases has been examined. The model can produce as many mixed solid phases as the number of waxy components. In binary mixtures, the solid rich in the lighter component contains little of the heavier component but the second phase shows sub...

  6. Synthesis of wax in the honeybee (Apis mellifera L.)

    NARCIS (Netherlands)

    Piek, T.

    1964-01-01

    Newly emerged honeybee workers were fed during 1 or 2 weeks with sucrose containing either heavy water, sodium acetate with deuterium, sodium acetate-1-14C, or uniformly labelled glucose-14C. The various lipid fractions were isolated in order to investigate the origin of the secreted wax components.

  7. EPICUTICULAR WAX COMPOSITION OF SOME EUROPEAN SEDUM SPECIES

    NARCIS (Netherlands)

    STEVENS, JF; THART, H; BOLCK, A; ZWAVING, JH; MALINGRE, TM

    1994-01-01

    Epicuticular waxes from 30 species of Sedum and 2 species of Sempervivoideae, i.e. Aeonium spathulatum and Sempervivum nevadense, have been analysed by GC and GC-MS. The Sedum taxa examined were S. acre, S. album, S. series Alpestria (13 species), S. anglicum, S. brevifolium, S. litoreum, S. lydium,

  8. Grain boundary wetness of partially molten dunite

    Science.gov (United States)

    Mu, S.; Faul, U.

    2013-12-01

    The grain scale melt distribution plays a key role for physical properties of partially molten regions in Earth's upper mantle, but our current understanding of the distribution of basaltic melt at the grain scale is still incomplete. A recent experimental study shows that wetted two-grain boundaries are a common feature of partially molten dunite at small melt fractions (Garapic et al., G3, 2013). In early ideal models which assume isotropic surface energy, the grain scale melt distribution is uniquely determined by knowing the melt fraction and the dihedral angle between two crystalline grains and the melt (von Bargen and Waff, JGR, 1986). Olivine is anisotropic in surface energy, hence the grain scale melt distribution at given melt fraction cannot be characterized by the dihedral angle alone. The grain boundary wetness, which is defined as the ratio of solid-liquid boundary area over the total interfacial area (Takei, JGR, 1998), is a more objective measure of the grain scale melt distribution. The aim of this study is to quantify the relationship between grain size, melt fraction, temperature and grain boundary wetness of partially molten dunite under dry conditions. We annealed olivine-basalt aggregates with melt fractions from 0.03% to 6% at a range of temperatures and 1 GPa in a piston cylinder for 1 to 336 hours, with resulting mean grain sizes of 10 to 60 μm. The samples were sectioned, polished and imaged at high resolution by using a field emission SEM. Each image had a size of 2048 x 1536 pixels with a resolution of 0.014 to 0.029 μm/pixel, depending on magnification. For each sample, depending on grain sizes, we made mosaics of 3 x 3 or 6 x 6 overlapping images. Measurements of melt fraction, grain boundary wetness and grain size were carried out on these high resolution mosaics by using ImageJ software. Analyses of mosaics show that grain boundary wetness increases with increasing melt fraction at constant grain size to values well above those

  9. Parametric study of natural circulation flow in molten salt fuel in molten salt reactor

    Science.gov (United States)

    Pauzi, Anas Muhamad; Cioncolini, Andrea; Iacovides, Hector

    2015-04-01

    The Molten Salt Reactor (MSR) is one of the most promising system proposed by Generation IV Forum (GIF) for future nuclear reactor systems. Advantages of the MSR are significantly larger compared to other reactor system, and is mainly achieved from its liquid nature of fuel and coolant. Further improvement to this system, which is a natural circulating molten fuel salt inside its tube in the reactor core is proposed, to achieve advantages of reducing and simplifying the MSR design proposed by GIF. Thermal hydraulic analysis on the proposed system was completed using a commercial computation fluid dynamics (CFD) software called FLUENT by ANSYS Inc. An understanding on theory behind this unique natural circulation flow inside the tube caused by fission heat generated in molten fuel salt and tube cooling was briefly introduced. Currently, no commercial CFD software could perfectly simulate natural circulation flow, hence, modeling this flow problem in FLUENT is introduced and analyzed to obtain best simulation results. Results obtained demonstrate the existence of periodical transient nature of flow problem, hence improvements in tube design is proposed based on the analysis on temperature and velocity profile. Results show that the proposed system could operate at up to 750MW core power, given that turbulence are enhanced throughout flow region, and precise molten fuel salt physical properties could be defined. At the request of the authors and the Proceedings Editor the name of the co-author Andrea Cioncolini was corrected from Andrea Coincolini. The same name correction was made in the Acknowledgement section on page 030004-10 and in reference number 4. The updated article was published on 11 May 2015.

  10. Molten Fuel-Coolant Interactions induced by coolant injection into molten fuel

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.S.; Yamano, Norihiko; Maruyama, Yu; Moriyama, Kiyofumi; Yang, Y.; Sugimoto, Jun [Severe Accident Research Laboratory, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan)

    1999-07-01

    To investigate Molten Fuel-Coolant Interactions (MFCIs) in various contact geometries, an experimental program, called MUSE (MUlti-configurations in Steam Explosions), has been initiated under the ALPHA program at JAERI in Japan. The first series of MUSE test has been focused on the coolant injection (CI) and stratified modes of FCIs using water as coolant and molten thermite as molten fuel. The effects of water jet subcooling, jet dynamics, jet shape and system constraint on FCIs energetic in these modes were experimentally investigated by precisely measuring their mechanical energy release in the MUSE facility. It was observed that measured mechanical energy increased with increasing of jet subcooling in a weakly constraint system but decreased in a strongly constraint system. FCI energetic also increased with increasing of water jet velocity. These results suggested that the penetration and dispersion phenomena of a water jet inside a melt determined the mixing conditions of FCIs in these contact modes and consequently played important roles on FCI energetics. To understand fundamental physics of these phenomena and possible mixing conditions in the MUSE tests, a set of visualization tests with several pairs of jet-pool liquids in non-boiling and isothermal conditions were carried out. Numerical simulations of a water jet penetrating into a water pool at non-boiling conditions showed similar behaviors to those observed in the visualization tests. (author)

  11. Castable cements to prevent corrosion of metals in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Vidal, J. C.; Morton, E.

    2016-08-01

    Castable cements on metals form a protective barrier that is able to prevent permeation of molten salts towards metallic surfaces. Silica-based castable cements are capable of protecting containment metallic alloys from the corrosive attack of molten chlorides at temperatures as high as 650 degrees C. Boron nitride (BN) blocking the pores in the cured cement prevents permeation of the molten chloride towards the metal surface. The cements tested are not chemically stable in molten carbonates, because the bonding components dissolved into molten carbonates salt. The corrosion rate is 7.72+/-0.32 mm/year for bare stainless steel 347 in molten eutectic NaCl - 65.58 wt% LiCl at 650 degrees C, which is the baseline used for determining how well the cement protects the metallic surfaces from corrosion. In particular the metal fully encapsulated with Aremco 645-N with pores filled with boron nitride immersed in molten eutectic NaCl - 65.58 wt% LiCl at 650 degrees C shows a corrosion rate of 9E-04 mm/year. The present study gives initial corrosion rates. Long-term tests are required to determine if Aremco 645-N with BN coating on metal has long term chemical stability for blocking salt permeation through coating pores.

  12. Increased production of wax esters in transgenic tobacco plants by expression of a fatty acid reductase:wax synthase gene fusion.

    Science.gov (United States)

    Aslan, Selcuk; Hofvander, Per; Dutta, Paresh; Sun, Chuanxin; Sitbon, Folke

    2015-12-01

    Wax esters are hydrophobic lipids consisting of a fatty acid moiety linked to a fatty alcohol with an ester bond. Plant-derived wax esters are today of particular concern for their potential as cost-effective and sustainable sources of lubricants. However, this aspect is hampered by the fact that the level of wax esters in plants generally is too low to allow commercial exploitation. To investigate whether wax ester biosynthesis can be increased in plants using transgenic approaches, we have here exploited a fusion between two bacterial genes together encoding a single wax ester-forming enzyme, and targeted the resulting protein to chloroplasts in stably transformed tobacco (Nicotiana benthamiana) plants. Compared to wild-type controls, transgenic plants showed both in leaves and stems a significant increase in the total level of wax esters, being eight-fold at the whole plant level. The profiles of fatty acid methyl ester and fatty alcohol in wax esters were related, and C16 and C18 molecules constituted predominant forms. Strong transformants displayed certain developmental aberrations, such as stunted growth and chlorotic leaves and stems. These negative effects were associated with an accumulation of fatty alcohols, suggesting that an adequate balance between formation and esterification of fatty alcohols is crucial for a high wax ester production. The results show that wax ester engineering in transgenic plants is feasible, and suggest that higher yields may become achieved in the near future.

  13. Molten Composition B Viscosity at Elevated Temperature

    Science.gov (United States)

    Zerkle, David K.; Núñez, Marcel P.; Zucker, Jonathan M.

    2016-10-01

    A shear-thinning viscosity model is developed for molten Composition B at elevated temperature from analysis of falling ball viscometer data. Results are reported with the system held at 85, 110, and 135°C. Balls of densities of 2.7, 8.0, and 15.6 g/cm3 are dropped to generate a range of strain rates in the material. Analysis of video recordings gives the speed at which the balls fall. Computer simulation of the viscometer is used to determine parameters for a non-Newtonian model calibrated to measured speeds. For the first time, viscosity is shown to be a function of temperature and strain rate-dependent maximum RDX (cyclotrimethylenetrinitramine) particle volume fraction.

  14. Modelisation of the SECMin molten salts environment

    Science.gov (United States)

    Lucas, M.; Slim, C.; Delpech, S.; di Caprio, D.; Stafiej, J.

    2014-06-01

    We develop a cellular automata modelisation of SECM experiments to study corrosion in molten salt media for generation IV nuclear reactors. The electrodes used in these experiments are cylindrical glass tips with a coaxial metal wire inside. As the result of simulations we obtain the current approach curves of the electrodes with geometries characterized by several values of the ratios of glass to metal area at the tip. We compare these results with predictions of the known analytic expressions, solutions of partial differential equations for flat uniform geometry of the substrate. We present the results for other, more complicated substrate surface geometries e. g. regular saw modulated surface, surface obtained by Eden model process, ...

  15. Molten salts database for energy applications

    CERN Document Server

    Serrano-López, Roberto; Cuesta-López, Santiago

    2013-01-01

    The growing interest in energy applications of molten salts is justified by several of their properties. Their possibilities of usage as a coolant, heat transfer fluid or heat storage substrate, require thermo-hydrodynamic refined calculations. Many researchers are using simulation techniques, such as Computational Fluid Dynamics (CFD) for their projects or conceptual designs. The aim of this work is providing a review of basic properties (density, viscosity, thermal conductivity and heat capacity) of the most common and referred salt mixtures. After checking data, tabulated and graphical outputs are given in order to offer the most suitable available values to be used as input parameters for other calculations or simulations. The reviewed values show a general scattering in characterization, mainly in thermal properties. This disagreement suggests that, in several cases, new studies must be started (and even new measurement techniques should be developed) to obtain accurate values.

  16. Molten-Salt Depleted-Uranium Reactor

    CERN Document Server

    Dong, Bao-Guo; Gu, Ji-Yuan

    2015-01-01

    The supercritical, reactor core melting and nuclear fuel leaking accidents have troubled fission reactors for decades, and greatly limit their extensive applications. Now these troubles are still open. Here we first show a possible perfect reactor, Molten-Salt Depleted-Uranium Reactor which is no above accident trouble. We found this reactor could be realized in practical applications in terms of all of the scientific principle, principle of operation, technology, and engineering. Our results demonstrate how these reactors can possess and realize extraordinary excellent characteristics, no prompt critical, long-term safe and stable operation with negative feedback, closed uranium-plutonium cycle chain within the vessel, normal operation only with depleted-uranium, and depleted-uranium high burnup in reality, to realize with fission nuclear energy sufficiently satisfying humanity long-term energy resource needs, as well as thoroughly solve the challenges of nuclear criticality safety, uranium resource insuffic...

  17. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    Energy Technology Data Exchange (ETDEWEB)

    James K. Neathery; Gary Jacobs; Amitava Sarkar; Burtron H. Davis

    2006-03-31

    The morphological and chemical nature of ultrafine iron catalyst particles (3-5 nm diameters) during activation/FTS was studied by HRTEM, EELS, and Moessbauer spectroscopy. With the progress of FTS, the carbide re-oxidized to magnetite and catalyst activity gradually decreased. The growth of oxide phase continued and average particle size also increased simultaneously. The phase transformation occurred in a ''growing oxide core'' manner with different nano-zones. The nano-range carbide particles did not show fragmentation or attrition as generally observed in micrometer range particles. Nevertheless, when the dimension of particles reached the micrometer range, the crystalline carbide phase appeared to be sprouted on the surface of magnetite single crystal. In the previous reporting period, a design and operating philosophy was developed for an integrated wax filtration system for a 4 liter slurry bubble column reactor to be used in Phase II of this research program. During the current reporting period, we have started construction of the new filtration system and began modifications to the 4 liter slurry bubble column reactor (SBCR) reactor. The system will utilize a primary wax separation device followed by a Pall Accusep or Membralox ceramic cross-flow membrane. As of this writing, the unit is nearly complete except for the modification of a moyno-type pump; the pump was shipped to the manufacturer to install a special leak-free, high pressure seal.

  18. Fast Spectrum Molten Salt Reactor Options

    Energy Technology Data Exchange (ETDEWEB)

    Gehin, Jess C [ORNL; Holcomb, David Eugene [ORNL; Flanagan, George F [ORNL; Patton, Bruce W [ORNL; Howard, Rob L [ORNL; Harrison, Thomas J [ORNL

    2011-07-01

    During 2010, fast-spectrum molten-salt reactors (FS-MSRs) were selected as a transformational reactor concept for light-water reactor (LWR)-derived heavy actinide disposition by the Department of Energy-Nuclear Energy Advanced Reactor Concepts (ARC) program and were the subject of a preliminary scoping investigation. Much of the reactor description information presented in this report derives from the preliminary studies performed for the ARC project. This report, however, has a somewhat broader scope-providing a conceptual overview of the characteristics and design options for FS-MSRs. It does not present in-depth evaluation of any FS-MSR particular characteristic, but instead provides an overview of all of the major reactor system technologies and characteristics, including the technology developments since the end of major molten salt reactor (MSR) development efforts in the 1970s. This report first presents a historical overview of the FS-MSR technology and describes the innovative characteristics of an FS-MSR. Next, it provides an overview of possible reactor configurations. The following design features/options and performance considerations are described including: (1) reactor salt options-both chloride and fluoride salts; (2) the impact of changing the carrier salt and actinide concentration on conversion ratio; (3) the conversion ratio; (4) an overview of the fuel salt chemical processing; (5) potential power cycles and hydrogen production options; and (6) overview of the performance characteristics of FS-MSRs, including general comparative metrics with LWRs. The conceptual-level evaluation includes resource sustainability, proliferation resistance, economics, and safety. The report concludes with a description of the work necessary to begin more detailed evaluation of FS-MSRs as a realistic reactor and fuel cycle option.

  19. Stable colloids in molten inorganic salts

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao; Dasbiswas, Kinjal; Ludwig, Nicholas B.; Han, Gang; Lee, Byeongdu; Vaikuntanathan, Suri; Talapin, Dimitri V.

    2017-02-16

    A colloidal solution is a homogeneous dispersion of particles or droplets of one phase (solute) in a second, typically liquid, phase (solvent). Colloids are ubiquitous in biological, chemical and technological processes1, 2, homogenizing highly dissimilar constituents. To stabilize a colloidal system against coalescence and aggregation, the surface of each solute particle is engineered to impose repulsive forces strong enough to overpower van der Waals attraction and keep the particles separated from each other2. Electrostatic stabilization3, 4 of charged solutes works well in solvents with high dielectric constants, such as water (dielectric constant of 80). In contrast, colloidal stabilization in solvents with low polarity, such as hexane (dielectric constant of about 2), can be achieved by decorating the surface of each particle of the solute with molecules (surfactants) containing flexible, brush-like chains2, 5. Here we report a class of colloidal systems in which solute particles (including metals, semiconductors and magnetic materials) form stable colloids in various molten inorganic salts. The stability of such colloids cannot be explained by traditional electrostatic and steric mechanisms. Screening of many solute–solvent combinations shows that colloidal stability can be traced to the strength of chemical bonding at the solute–solvent interface. Theoretical analysis and molecular dynamics modelling suggest that a layer of surface-bound solvent ions produces long-ranged charge-density oscillations in the molten salt around solute particles, preventing their aggregation. Colloids composed of inorganic particles in inorganic melts offer opportunities for introducing colloidal techniques to solid-state science and engineering applications.

  20. Molten carbonate fuel cell technology improvement

    Energy Technology Data Exchange (ETDEWEB)

    1991-06-01

    This report summarizes the work performed under Department of Energy Contract DEAC21-87MC23270, Molten Carbonate Fuel Cell Technology Improvement.'' This work was conducted over a three year period and consisted of three major efforts. The first major effort was the power plant system study which reviewed the competitive requirements for a coal gasifier/molten carbonate fuel cell power plant, produced a conceptual design of a CG/MCFC, and defined the technology development requirements. This effort is discussed in Section 1 of the report. The second major effort involved the design and development of a new MCFC cell configuration which reduced the material content of the cell to a level competitive with competing power plants, simplified the cell configuration to make the components more manufacturable and adaptable to continuous low cost processing techniques, and introduced new-low-pressure drop flow fields for both reactant gases. The new flow fields permitted the incorporation of recirculation systems in both reactant gas systems, permitting simplified cooling techniques and the ability to operate on both natural gas and a wide variety of gasifier fuels. This cell technology improvement is discussed in Section 2. The third major effort involved the scaleup of the new cell configuration to the full-area, 8-sq-ft size and resulted in components used for a 25-kW, 20-cell stack verification test. The verification test was completed with a run of 2200 hours, exceeding the goal of 2000 hours and verifying the new cell design. TWs test, in turn, provided the confidence to proceed to a 100-kW demonstration which is the goal of the subsequent DOE program. The scaleup and stack verification tests are discussed in Sections 3, 4, 5, and 6 of this report.

  1. Simulation tools and new developments of the molten salt fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Merle-Lucotte, E.; Doligez, X.; Heuer, D.; Allibert, M.; Ghetta, V. [LPSC-IN2P3-CNRS / UJF / Grenoble INP, 53 avenue des Martyrs, F-38026 Grenoble Cedex (France)

    2010-07-01

    Starting from the Molten Salt Breeder Reactor project of Oak-Ridge, we have performed parametric studies in terms of safety coefficients, reprocessing requirements and breeding capabilities. In the frame of this major re-evaluation of the molten salt reactor (MSR), we have developed a new concept called Molten Salt Fast Reactor or MSFR, based on the Thorium fuel cycle and a fast neutron spectrum. This concept has been selected for further studies by the MSR steering committee of the Generation IV International Forum in 2009. Our reactor's studies of the MSFR concept rely on numerical simulations making use of the MCNP neutron transport code coupled with a code for materials evolution which resolves the Bateman's equations giving the population of each nucleus inside each part of the reactor at each moment. Because of MSR's fundamental characteristics compared to classical solid-fuelled reactors, the classical Bateman equations have to be modified by adding two terms representing the reprocessing capacities and the fertile or fissile alimentation. We have thus coupled neutronic and reprocessing simulation codes in a numerical tool used to calculate the extraction efficiencies of fission products, their location in the whole system (reactor and reprocessing unit) and radioprotection issues. (authors)

  2. DEWAX-mediated transcriptional repression of cuticular wax biosynthesis in Arabidopsis thaliana.

    Science.gov (United States)

    Suh, Mi Chung; Go, Young Sam

    2014-06-06

    The aerial parts of plants are covered with a cuticular wax layer, which is the first barrier between a plant and its environment. Although cuticular wax deposition increases more in the light than in the dark, little is known about the molecular mechanisms underlying the regulation of cuticular wax biosynthesis. Recently DEWAX (Decrease Wax Biosynthesis) encoding an AP2/ERF transcription factor was found to be preferentially expressed in the epidermis and induced by darkness. Wax analysis of the dewax knockout mutant, wild type, and DEWAX overexpression lines (OX) indicates that DEWAX is a negative regulator of cuticular wax biosynthesis. DEWAX represses the expression of wax biosynthetic genes CER1, LACS2, ACLA2, and ECR via direct interaction with their promoters. Cuticular wax biosynthesis is negatively regulated twice a day by the expression of DEWAX; throughout the night and another for stomata closing. Taken together, it is evident that DEWAX-mediated negative regulation of the wax biosynthetic genes plays role in determining the total wax loads produced in Arabidopsis during daily dark and light cycles. In addition, significantly higher levels of DEWAX transcripts in leaves than stems suggest that DEWAX-mediated transcriptional repression might be involved in the organ-specific regulation of total wax amounts on plant surfaces.

  3. Apparatus and method for stripping tritium from molten salt

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, David E.; Wilson, Dane F.

    2017-02-07

    A method of stripping tritium from flowing stream of molten salt includes providing a tritium-separating membrane structure having a porous support, a nanoporous structural metal-ion diffusion barrier layer, and a gas-tight, nonporous palladium-bearing separative layer, directing the flowing stream of molten salt into contact with the palladium-bearing layer so that tritium contained within the molten salt is transported through the tritium-separating membrane structure, and contacting a sweep gas with the porous support for collecting the tritium.

  4. A Possible Regenerative, Molten-Salt, Thermoelectric Fuel Cell

    Science.gov (United States)

    Greenberg, Jacob; Thaller, Lawrence H.; Weber, Donald E.

    1964-01-01

    Molten or fused salts have been evaluated as possible thermoelectric materials because of the relatively good values of their figures of merit, their chemical stability, their long liquid range, and their ability to operate in conjunction with a nuclear reactor to produce heat. In general, molten salts are electrolytic conductors; therefore, there will be a transport of materials and subsequent decomposition with the passage of an electric current. It is possible nonetheless to overcome this disadvantage by using the decomposition products of the molten-salt electrolyte in a fuel cell. The combination of a thermoelectric converter and a fuel cell would lead to a regenerative system that may be useful.

  5. Apparatus and method for stripping tritium from molten salt

    Science.gov (United States)

    Holcomb, David E.; Wilson, Dane F.

    2017-02-07

    A method of stripping tritium from flowing stream of molten salt includes providing a tritium-separating membrane structure having a porous support, a nanoporous structural metal-ion diffusion barrier layer, and a gas-tight, nonporous palladium-bearing separative layer, directing the flowing stream of molten salt into contact with the palladium-bearing layer so that tritium contained within the molten salt is transported through the tritium-separating membrane structure, and contacting a sweep gas with the porous support for collecting the tritium.

  6. Control strategies in a thermal oil - Molten salt heat exchanger

    Science.gov (United States)

    Roca, Lidia; Bonilla, Javier; Rodríguez-García, Margarita M.; Palenzuela, Patricia; de la Calle, Alberto; Valenzuela, Loreto

    2016-05-01

    This paper presents a preliminary control scheme for a molten salt - thermal oil heat exchanger. This controller regulates the molten salt mass flow rate to reach and maintain the desired thermal oil temperature at the outlet of the heat exchanger. The controller architecture has been tested using an object-oriented heat exchanger model that has been validated with data from a molten salt testing facility located at CIEMAT-PSA. Different simulations are presented with three different goals: i) to analyze the controller response in the presence of disturbances, ii) to demonstrate the benefits of designing a setpoint generator and iii) to show the controller potential against electricity price variations.

  7. 75 FR 70713 - Petroleum Wax Candles From the People's Republic of China: Final Results of Expedited Third...

    Science.gov (United States)

    2010-11-18

    ... order are certain scented or unscented petroleum wax candles made from petroleum wax and having fiber or... International Trade Administration Petroleum Wax Candles From the People's Republic of China: Final Results of... petroleum wax candles from the People's Republic of China (``PRC''). On the basis of a timely notice...

  8. 76 FR 773 - Petroleum Wax Candles From the People's Republic of China: Continuation of Antidumping Duty Order

    Science.gov (United States)

    2011-01-06

    ... a reasonably foreseeable future. See Petroleum Wax Candles From China Determination, 75 FR 80843... scented or unscented petroleum wax candles made from petroleum wax and having fiber or paper-cored wicks... International Trade Administration Petroleum Wax Candles From the People's Republic of China: Continuation...

  9. Mechanical properties of carving wax with various Ca-bentolite filter composition

    Directory of Open Access Journals (Sweden)

    Widjijono Widjijono

    2009-09-01

    Full Text Available Background: The carving wax is used as a medium in dental anatomy study. This wax composes of many waxes and sometimes a filler is added. Carving wax is not sold in Indonesian market. Whereas the gradients of carving wax such as beeswax, paraffin and bentonite are abundant in Indonesia. Based on that fact, to make high quality and standard,the exact composition if this carving wax should be known. Purpose: The aim of this study was to investigate the effect of carving wax composition with Ca-bentonite filler on the melting point, hardness, and thermal expansion. Methods: Five carving wax compositions were made with paraffin, Ca-bentonite, carnauba wax, and beeswax in ratio (% weight: 50:20:25:5 (KI, 55:15:25:5 (KII, 60:10:25:5 (KIII, 65:5:25:5 (KIV, 70:0:25:5(KV. All components were melted, then poured into the melting point, hardness, and thermal expansion moulds (n = 5. Three carving wax properties were tested: melting point by melting point apparatus; hardness by penetrometer; thermal expansion by digital sliding caliper. The data were analyzed statistically using One-Way ANOVA and LSD0.05. Result: The Ca-bentonite addition influenced the melting point and thermal expansion of carving wax with significant differences between KI and other groups (p < 0.05. Ca-bentonite addition influenced the carving wax hardness and the mean differences among the groups were significant (p < 0.05. Conclusion: Ca-bentonite filler addition on the composition of carving wax influenced the physical and mechanical properties. The carving wax with high Ca-bentonite concentration had high melting point and hardness, but low thermal expansion.

  10. Molten Salt: Concept Definition and Capital Cost Estimate

    Energy Technology Data Exchange (ETDEWEB)

    Stoddard, Larry [Black & Veatch, Kansas City, MO (United States); Andrew, Daniel [Black & Veatch, Kansas City, MO (United States); Adams, Shannon [Black & Veatch, Kansas City, MO (United States); Galluzzo, Geoff [Black & Veatch, Kansas City, MO (United States)

    2016-06-30

    The Department of Energy’s (DOE’s) Office of Renewable Power (ORP) has been tasked to provide effective program management and strategic direction for all of the DOE’s Energy Efficiency & Renewable Energy’s (EERE’s) renewable power programs. The ORP’s efforts to accomplish this mission are aligned with national energy policies, DOE strategic planning, EERE’s strategic planning, Congressional appropriation, and stakeholder advice. ORP is supported by three renewable energy offices, of which one is the Solar Energy Technology Office (SETO) whose SunShot Initiative has a mission to accelerate research, development and large scale deployment of solar technologies in the United States. SETO has a goal of reducing the cost of Concentrating Solar Power (CSP) by 75 percent of 2010 costs by 2020 to reach parity with base-load energy rates, and to reduce costs 30 percent further by 2030. The SunShot Initiative is promoting the implementation of high temperature CSP with thermal energy storage allowing generation during high demand hours. The SunShot Initiative has funded significant research and development work on component testing, with attention to high temperature molten salts, heliostats, receiver designs, and high efficiency high temperature supercritical CO2 (sCO2) cycles. DOE retained Black & Veatch to support SETO’s SunShot Initiative for CSP solar power tower technology in the following areas: 1. Concept definition, including costs and schedule, of a flexible test facility to be used to test and prove components in part to support financing. 2. Concept definition, including costs and schedule, of an integrated high temperature molten salt (MS) facility with thermal energy storage and with a supercritical CO2 cycle generating approximately 10MWe. 3. Concept definition, including costs and schedule, of an integrated high temperature falling particle facility with thermal energy storage and with a supercritical CO2

  11. Erosion Effect of Molten Steel on Carbon Containing Refractories for Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    LI Hongxia; YANG Bin; LIU Guoqi; CHENG Hepeng

    2007-01-01

    The erosion resistance of carbon containing refractories for continuous casting to molten steel was investigated by means of simulative erosion test and examining used refractories.Decolonization and reaction between molten steel and decolonization layer are main erosion process of carbon containing refractories by1 molten steel.The reactions between molten steel and oxide in refractories determine the thickness of decarbonization layer A dense layer formation on the working surface contacting with molten steel during casting will suppress decarbonization and erosion process.

  12. Surface tension of molten tin investigated with sessile drop method

    Institute of Scientific and Technical Information of China (English)

    LI Jing; YUAN Zhang-fu; FAN Jian-feng; KE Jia-jun

    2005-01-01

    The surface tension of molten tin was determined by a set of self-developed digital equipment with sessile drop method at oxygen partial pressure of 1.0 × 10-6 MPa under different temperatures, and the dependence of surface tension of molten tin on temperature was also discussed. The emphasis was placed on the comparison of surface tension of the same molten tin sample measured by using different equipments with sessile drop method. Results of the comparison indicate that the measurement results with sessile drop method under the approximate experimental conditions are coincident, and the self-developed digital equipment for surface tension measurement has higher stability and accuracy. The relationships of surface tension of molten tin and its temperature coefficient with temperature and oxygen partial pressure were also elucidated from the thermodynamic equilibrium analysis.

  13. System Requirements Document for the Molten Salt Reactor Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aigner, R.D.

    2000-04-01

    The purpose of the conversion process is to convert the {sup 233}U fluoride compounds that are being extracted from the Molten Salt Reactor Experiment (MSRE) equipment to a stable oxide for long-term storage at Bldg. 3019.

  14. Large Scale Inert Anode for Molten Oxide Electrolysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Molten oxide electrolysis is a demonstrated laboratory-scale process for producing oxygen from the JSC-1a lunar simulant; however, critical subsystems necessary for...

  15. High Surface Iridium Anodes for Molten Oxide Electrolysis Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Processing of lunar regolith into oxygen for habitat and propulsion is needed to support future space missions. Direct electrochemical reduction of molten regolith...

  16. Segregation of Molten Salt on Chromizing in Thermal Diffusion Process

    Institute of Scientific and Technical Information of China (English)

    WANG Hongfu; WANG Junyuan; WANG Huachang

    2011-01-01

    The segregation of thermal diffusion salt bath chromizing process was analyzed.The experimental chromizing ingredients were prepared by the four groups A,B,C,and D.In order to study the segregation status of this case,the cooling molten salt in the crucible was removed by drilling from the heart core of molten salt.The core of molten salt was analyzed by X-ray fluorescence spectroscopy and XRD.Through the analysis,we can conclude that the Cr element deposited in the bottom was 4.51 times than the top.Chloride added to the molten salt will reduce segregation.Meantime we proposed some measures to overcome the segregation problem.

  17. Polymers' surface interactions with molten iron: A theoretical study

    Science.gov (United States)

    Assadi, M. Hussein N.; Sahajwalla, Veena

    2014-10-01

    Environmental concerns are the chief drive for more innovative recycling techniques for end-of-life polymeric products. One attractive option is taking advantage of C and H content of polymeric waste in steelmaking industry. In this work, we examined the interaction of two high production polymers i.e. polyurethane and polysulfide with molten iron using ab initio molecular dynamics simulation. We demonstrate that both polymers can be used as carburizers for molten iron. Additionally, we found that light weight H2 and CHx molecules were released as by-products of the polymer-molten iron interaction. The outcomes of this study will have applications in the carburization of molten iron during ladle metallurgy and waste plastic injection in electric arc furnace.

  18. Density and Structure Analysis of Molten Ni-W Alloys

    Institute of Scientific and Technical Information of China (English)

    Feng XIAO; Liang FANG

    2004-01-01

    Density of molten Ni and Ni-W alloys was measured in the temperature range of 1773~1873 K with a sessile drop method.The density of molten Ni and Ni-W alloys trends to decrease with increasing temperature. The density and molar volume of the alloys trend to increase with increasing W concentration in the alloys. The calculation result shows an ideal mixing of Ni-W alloys.

  19. Molten fluoride mixtures as possible fission reactor fuels

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, W.R.

    1978-01-01

    Molten mixtures of fluorides with UF/sub 4/ as a component have been used as combined fuel and primary heat transfer agent in experimental high-temperature reactors and have been proposed for use in breeders or converters of /sup 233/U from thorium. Such use places stringent and diverse demands upon the fluid fuel. A brief review of chemical behavior of molten fluorides is given to show some of their strengths and weaknesses for such service.

  20. Minimizing the fissile inventory of the molten salt fast reactor

    OpenAIRE

    Merle-Lucotte, E.; Heuer, D.; Allibert, M.; Doligez, X.; Ghetta, V.

    2009-01-01

    International audience; Molten salt reactors in the configurations presented here, called Molten Salt Fast Reactors (MSFR), have been selected for further studies by the Generation IV International Forum. These reactors may be operated in simplified and safe conditions in the Th/233U fuel cycle with fluoride salts. We present here the concept, before focusing on a possible optimization in term of minimization of the initial fissile inventory. Our studies demonstrate that an inventory of 233U ...

  1. Thermodynamic characterization of salt components for Molten Salt Reactor fuel

    OpenAIRE

    Capelli, E.

    2016-01-01

    The Molten Salt Reactor (MSR) is a promising future nuclear fission reactor technology with excellent performance in terms of safety and reliability, sustainability, proliferation resistance and economics. For the design and safety assessment of this concept, it is extremely important to have a thorough knowledge of the physico-chemical properties of molten fluorides salts, which are one of the best options for the reactor fuel. This dissertation presents the thermodynamic description of the ...

  2. Relationship between waxy crude viscosities and wax crystal microstructure

    Institute of Scientific and Technical Information of China (English)

    高鹏; 张劲军; 侯磊; 王海峰

    2008-01-01

    It is important and profound to quantitatively study the relation between rheology and microstructure for development of the microstructural mechanism of crude oil rheology and even for the waxy crude oil pipelining.However,due to the high complexity and irregularity of wax crystal morphology,quantitative characterization is hard to achieve.This has hampered further study on the rheology-microstructure relationship.A new approach combined the fractal geometry and the stereology theory is presented for quantifying the intricate wax crystal morphology and structure.Based on the characterization,the effects of microstructures and oil composition on the waxy crude viscosities are analyzed quantitatively.It further validates the previous qualitative research and enriches understanding into the microstructural mechanism of waxy crude oil rheology.

  3. Thermal performance analysis of a thermocline thermal energy storage system with FLiNaK molten salt

    Science.gov (United States)

    Liu, C.; Cheng, M. S.; Zhao, B. C.; Dai, Z. M.

    2017-01-01

    A thermocline thermal storage unit with a heat transfer fluid (HTF) of high-temperature molten salt is considered as one of the most promising methods of thermal storage due to its lower cost and smaller size. The main objective of this work is to analyze the transient behavior of the available molten salt FLiNaK used as the HTF in heat transfer and heat storage in a thermocline thermal energy storage (TES) system. Thermal characteristics including temperature profiles influenced by different inlet velocities of HTF and different void fractions of porous heat storage medium are analyzed. The numerical investigation on the heat storage and heat transfer characteristics of FLiINaK has been carried out. A comparison between two different molten salts, FLiNaK and Hitec, has been explored in this paper with regards to their charging and discharging operations. The results indicate the system with FLiNaK has a greater energy storage capability, a shorter charging time and a higher output power. The numerical investigation reveals heat storage and heat transfer characteristics of the thermocline TES system with FLiNaK, and provide important references for molten salt selection of the TES system in the future.

  4. Status of benchmark calculations of the neutron characteristics of the cascade molten salt ADS for the nuclear waste incineration

    Energy Technology Data Exchange (ETDEWEB)

    Dudnikov, A.A.; Alekseev, P.N.; Subbotin, S.A.; Vasiliev, A.V.; Abagyan, L.P.; Alexeyev, N.I.; Gomin, E.A.; Ponomarev, L.I.; Kolyaskin, O.E.; Men' shikov, L.I. [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation); Kolesov, V.F.; Ivanin, I.A.; Zavialov, N.V. [Russian Federal Nuclear Center, RFNC-VNIIEF, Nizhnii Novgorod region (Russian Federation)

    2001-07-01

    The facility for incineration of long-lived minor actinides and some dangerous fission products should be an important feature of the future nuclear power (NP). For many reasons the liquid-fuel reactor driven by accelerator can be considered as the perspective reactor- burner for radioactive waste. The fuel of such reactor is the fluoride molten salt composition with minor actinides (Np, Cm, Am) and some fission products ({sup 99}Tc, {sup 129}I, etc.). Preliminary analysis shows that the values of keff, calculated with different codes and nuclear data differ up to several percents for such fuel compositions. Reliable critical and subcritical benchmark experiments with molten salt fuel compositions with significant quantities of minor actinides are absent. One of the main tasks for the numerical study of this problem is the estimation of nuclear data for such fuel compositions and verification of the different numerical codes used for the calculation of keff, neutron spectra and reaction rates. It is especially important for the resonance region where experimental data are poor or absent. The calculation benchmark of the cascade subcritical molten salt reactor is developed. For the chosen nuclear fuel composition the comparison of the results obtained by three different Monte-Carlo codes (MCNP4A, MCU, and C95) using three different nuclear data libraries are presented. This report concerns the investigation of subcritical molten salt reactor unit main peculiarities carried out at the beginning of ISTC project 1486. (author)

  5. Thermodynamic evaluation of the solidification phase of molten core-concrete under estimated Fukushima Daiichi nuclear power plant accident conditions

    Science.gov (United States)

    Kitagaki, Toru; Yano, Kimihiko; Ogino, Hideki; Washiya, Tadahiro

    2017-04-01

    The solidification phases of molten core-concrete under the estimated molten core-concrete interaction (MCCI) conditions in the Fukushima Daiichi Nuclear Power Plant Unit 1 were predicted using the thermodynamic equilibrium calculation tool, FactSage 6.2, and the NUCLEA database in order to contribute toward the 1F decommissioning work and to understand the accident progression via the analytical results for the 1F MCCI products. We showed that most of the U and Zr in the molten core-concrete forms (U,Zr)O2 and (Zr,U)SiO4, and the formation of other phases with these elements is limited. However, the formation of (Zr,U)SiO4 requires a relatively long time because it involves a change in the crystal structure from fcc-(U,Zr)O2 to tet-(U,Zr)O2, followed by the formation of (Zr,U)SiO4 by reaction with SiO2. Therefore, the formation of (Zr,U)SiO4 is limited under quenching conditions. Other common phases are the oxide phases, CaAl2Si2O8, SiO2, and CaSiO3, and the metallic phases of the Fe-Si and Fe-Ni alloys. The solidification phenomenon of the crust under quenching conditions and that of the molten pool under thermodynamic equilibrium conditions in the 1F MCCI progression are discussed.

  6. Oil adsorption ability of three-dimensional epicuticular wax coverages in plants

    Science.gov (United States)

    Gorb, Elena V.; Hofmann, Philipp; Filippov, Alexander E.; Gorb, Stanislav N.

    2017-04-01

    Primary aerial surfaces of terrestrial plants are very often covered with three-dimensional epicuticular waxes. Such wax coverages play an important role in insect-plant interactions. Wax blooms have been experimentally shown in numerous previous studies to be impeding locomotion and reducing attachment of insects. Among the mechanisms responsible for these effects, a possible adsorption of insect adhesive fluid by highly porous wax coverage has been proposed (adsorption hypothesis). Recently, a great decrease in insect attachment force on artificial adsorbing materials was revealed in a few studies. However, adsorption ability of plant wax blooms was still not tested. Using a cryo scanning electron microscopy approach and high-speed video recordings of fluid drops behavior, followed by numerical analysis of experimental data, we show here that the three-dimensional epicuticular wax coverage in the waxy zone of Nepenthes alata pitcher adsorbs oil: we detected changes in the base, height, and volume of the oil drops. The wax layer thickness, differing in samples with untreated two-layered wax coverage and treated one-layered wax, did not significantly affect the drop behavior. These results provide strong evidence that three-dimensional plant wax coverages due to their adsorption capability are in general anti-adhesive for insects, which rely on wet adhesion.

  7. Oil adsorption ability of three-dimensional epicuticular wax coverages in plants

    Science.gov (United States)

    Gorb, Elena V.; Hofmann, Philipp; Filippov, Alexander E.; Gorb, Stanislav N.

    2017-01-01

    Primary aerial surfaces of terrestrial plants are very often covered with three-dimensional epicuticular waxes. Such wax coverages play an important role in insect-plant interactions. Wax blooms have been experimentally shown in numerous previous studies to be impeding locomotion and reducing attachment of insects. Among the mechanisms responsible for these effects, a possible adsorption of insect adhesive fluid by highly porous wax coverage has been proposed (adsorption hypothesis). Recently, a great decrease in insect attachment force on artificial adsorbing materials was revealed in a few studies. However, adsorption ability of plant wax blooms was still not tested. Using a cryo scanning electron microscopy approach and high-speed video recordings of fluid drops behavior, followed by numerical analysis of experimental data, we show here that the three-dimensional epicuticular wax coverage in the waxy zone of Nepenthes alata pitcher adsorbs oil: we detected changes in the base, height, and volume of the oil drops. The wax layer thickness, differing in samples with untreated two-layered wax coverage and treated one-layered wax, did not significantly affect the drop behavior. These results provide strong evidence that three-dimensional plant wax coverages due to their adsorption capability are in general anti-adhesive for insects, which rely on wet adhesion. PMID:28367985

  8. Adhesion force measurements on the two wax layers of the waxy zone in Nepenthes alata pitchers.

    Science.gov (United States)

    Gorb, Elena V; Purtov, Julia; Gorb, Stanislav N

    2014-06-03

    The wax coverage of the waxy zone in Nepenthes alata pitchers consists of two clearly distinguishable layers, designated the upper and lower wax layers. Since these layers were reported to reduce insect attachment, they were considered to have anti-adhesive properties. However, no reliable adhesion tests have been performed with these wax layers. In this study, pull-off force measurements were carried out on both wax layers of the N. alata pitcher and on two reference polymer surfaces using deformable polydimethylsiloxane half-spheres as probes. To explain the results obtained, roughness measurements were performed on test surfaces. Micro-morphology of both surface samples and probes tested was examined before and after experiments. Pull-off forces measured on the upper wax layer were the lowest among surfaces tested. Here, contamination of probes by wax crystals detached from the pitcher surface was found. This suggests that low insect attachment on the upper wax layer is caused primarily by the breaking off of wax crystals from the upper wax layer, which acts as a separation layer between the insect pad and the pitcher surface. High adhesion forces obtained on the lower wax layer are explained by the high deformability of probes and the particular roughness of the substrate.

  9. Determination of serotonin released from coffee wax by liquid chromatography.

    Science.gov (United States)

    Kele, M; Ohmacht, R

    1996-04-12

    A simple hydrolysis and extraction method was developed for the release of serotonin (5-hydroxytryptamine) from a coffee wax sample obtained from decaffeination of coffee beans. The recoverable amount of serotonin was determined by reversed-phase high-performance liquid chromatography with gradient elution and UV detection, using the standard addition method. Different type of basic deactivated chromatographic columns were used for the separation.

  10. Surfactants and Desensitizing Wax Substitutes for TNT-Based Systems.

    Science.gov (United States)

    1994-10-01

    36 esters, 25% long chain acids and 10% long chain alcohols, ketones, and hydrocarbons. The resin portion contains terpenes and resinic acids, while...aliphatic and aromatic resins and turpentine for terpene resins (i.e. polymerized B-pinene). The most important commercial products today are the resins...Wax desensitizes by suppressing these processes by: Filling voids that otherwise contain gases Separating individual crystals of explosive Absorbing

  11. Rheological profiling of organogels prepared at critical gelling concentrations of natural waxes in a triacylglycerol solvent.

    Science.gov (United States)

    Patel, Ashok R; Babaahmadi, Mehrnoosh; Lesaffer, Ans; Dewettinck, Koen

    2015-05-20

    The aim of this study was to use a detailed rheological characterization to gain new insights into the gelation behavior of natural waxes. To make a comprehensive case, six natural waxes (differing in the relative proportion of chemical components: hydrocarbons, fatty alcohols, fatty acids, and wax esters) were selected as organogelators to gel high-oleic sunflower oil. Flow and dynamic rheological properties of organogels prepared at critical gelling concentrations (Cg) of waxes were studied and compared using drag (stress ramp and steady flow) and oscillatory shear (stress and frequency sweeps) tests. Although, none of the organogels satisfied the rheological definition of a "strong gel" (G″/G' (ω) ≤ 0.1), on comparing the samples, the strongest gel (highest critical stress and dynamic, apparent, and static yield stresses) was obtained not with wax containing the highest proportion of wax esters alone (sunflower wax, SFW) but with wax containing wax esters along with a higher proportion of fatty alcohols (carnauba wax, CRW) although at a comparatively higher Cg (4%wt for latter compared to 0.5%wt for former). As expected, gel formation by waxes containing a high proportion of lower melting fatty acids (berry, BW, and fruit wax, FW) required a comparatively higher Cg (6 and 7%wt, respectively), and in addition, these gels showed the lowest values for plateau elastic modulus (G'LVR) and a prominent crossover point at higher frequency. The gelation temperatures (TG'=G″) for all the studied gels were lower than room temperature, except for SFW and CRW. The yielding-type behavior of gels was evident, with most gels showing strong shear sensitivity and a weak thixotropic recovery. The rheological behavior was combined with the results of thermal analysis and microstructure studies (optical, polarized, and cryo-scanning electron microscopy) to explain the gelation properties of these waxes.

  12. Wax layers on Cosmos bipinnatus petals contribute unequally to total petal water resistance.

    Science.gov (United States)

    Buschhaus, Christopher; Hager, Dana; Jetter, Reinhard

    2015-01-01

    Cuticular waxes coat all primary aboveground plant organs as a crucial adaptation to life on land. Accordingly, the properties of waxes have been studied in much detail, albeit with a strong focus on leaf and fruit waxes. Flowers have life histories and functions largely different from those of other organs, and it remains to be seen whether flower waxes have compositions and physiological properties differing from those on other organs. This work provides a detailed characterization of the petal waxes, using Cosmos bipinnatus as a model, and compares them with leaf and stem waxes. The abaxial petal surface is relatively flat, whereas the adaxial side consists of conical epidermis cells, rendering it approximately 3.8 times larger than the projected petal area. The petal wax was found to contain unusually high concentrations of C(22) and C(24) fatty acids and primary alcohols, much shorter than those in leaf and stem waxes. Detailed analyses revealed distinct differences between waxes on the adaxial and abaxial petal sides and between epicuticular and intracuticular waxes. Transpiration resistances equaled 3 × 10(4) and 1.5 × 10(4) s m(-1) for the adaxial and abaxial surfaces, respectively. Petal surfaces of C. bipinnatus thus impose relatively weak water transport barriers compared with typical leaf cuticles. Approximately two-thirds of the abaxial surface water barrier was found to reside in the epicuticular wax layer of the petal and only one-third in the intracuticular wax. Altogether, the flower waxes of this species had properties greatly differing from those on vegetative organs.

  13. Insect attachment on crystalline bioinspired wax surfaces formed by alkanes of varying chain lengths

    Directory of Open Access Journals (Sweden)

    Elena Gorb

    2014-07-01

    Full Text Available The impeding effect of plant surfaces covered with three-dimensional wax on attachment and locomotion of insects has been shown previously in numerous experimental studies. The aim of this study was to examine the effect of different parameters of crystalline wax coverage on insect attachment. We performed traction experiments with the beetle Coccinella septempunctata and pull-off force measurements with artificial adhesive systems (tacky polydimethylsiloxane semi-spheres on bioinspired wax surfaces formed by four alkanes of varying chain lengths (C36H74, C40H82, C44H90, and C50H102. All these highly hydrophobic coatings were composed of crystals having similar morphologies but differing in size and distribution/density, and exhibited different surface roughness. The crystal size (length and thickness decreased with an increase of the chain length of the alkanes that formed these surfaces, whereas the density of the wax coverage, as well as the surface roughness, showed an opposite relationship. Traction tests demonstrated a significant, up to 30 fold, reduction of insect attachment forces on the wax surfaces when compared with the reference glass sample. Attachment of the beetles to the wax substrates probably relied solely on the performance of adhesive pads. We found no influence of the wax coatings on the subsequent attachment ability of beetles. The obtained data are explained by the reduction of the real contact between the setal tips of the insect adhesive pads and the wax surfaces due to the micro- and nanoscopic roughness introduced by wax crystals. Experiments with polydimethylsiloxane semi-spheres showed much higher forces on wax samples when compared to insect attachment forces measured on these surfaces. We explain these results by the differences in material properties between polydimethylsiloxane probes and tenent setae of C. septempunctata beetles. Among wax surfaces, force experiments showed stronger insect attachment and higher

  14. Visualization of micromorphology of leaf epicuticular waxes of the rubber tree Ficus elastica by electron microscopy.

    Science.gov (United States)

    Kim, Ki Woo

    2008-10-01

    Ultrastructural aspects of leaf epicuticular waxes were investigated in Ficus elastica by scanning and transmission electron microscopy. Glossy leaves of the rubber tree were collected and subjected to different regimes of specimen preparation for surface observations. F. elastica leaves were hypostomatic and stomata were surrounded with a cuticular thickening that formed a rim. The most prominent epicuticular wax structures of F. elastica leaves included granules and platelets. Without fixation and metal coating, epicuticular wax structures could be discerned on the leaf surface by low-vacuum (ca. 7 Pa) scanning electron microscopy. In terms of delineation and retention of the structures, the combination of vapor fixation by glutaraldehyde and osmium tetroxide with subsequent gold coating provided the most satisfactory results, as evidenced by high resolution and sharp protrusions of epicuticular waxes. However, erosion of epicuticular wax edges was noted in the immersion fixed leaves, showing less elongated platelets, less distinct wax edges, and granule cracking. These results suggest that the vapor fixation procedure for demonstrating three-dimensional epicuticular wax structures would facilitate characterization of diverse types of waxes. Instances were noted where epicuticular waxes grew over neighboring epidermal ridges and occluded stomata. In cross sections, epicuticular waxes were observed above the cuticle proper and ranged approximately from 100 nm to 500 nm in thickness. The native leaf epicuticular waxes had many layers of different electron density that were oriented parallel to each other and parallel or perpendicular to the cuticle surface, implying strata of crystal growth. Such retention of native epicuticular wax structures could be achieved through the use of acrylic resin treated with less harsh dehydrants and mild heat polymerization, alleviating wax extraction during specimen preparations.

  15. Glovebox design requirements for molten salt oxidation processing of transuranic waste

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, K.B.; Acosta, S.V. [Los Alamos National Lab., NM (United States); Wernly, K.D. [Molten Salt Oxidation Corp., Bensalem, PA (United States)

    1998-12-31

    This paper presents an overview of potential technologies for stabilization of {sup 238}Pu-contaminated combustible waste. Molten salt oxidation (MSO) provides a method for removing greater than 99.999% of the organic matrix from combustible waste. Implementation of MSO processing at the Los Alamos National Laboratory (LANL) Plutonium Facility will eliminate the combustible matrix from {sup 238}Pu-contaminated waste and consequently reduce the cost of TRU waste disposal operations at LANL. The glovebox design requirements for unit operations including size reduction and MSO processing will be presented.

  16. Leaf waxes in litter and topsoils along a European transect

    Science.gov (United States)

    Schäfer, Imke K.; Lanny, Verena; Franke, Jörg; Eglinton, Timothy I.; Zech, Michael; Vysloužilová, Barbora; Zech, Roland

    2016-10-01

    Lipid biomarkers are increasingly used to reconstruct past environmental and climate conditions. Leaf-wax-derived long-chain n-alkanes and n-alkanoic acids may have great potential for reconstructing past changes in vegetation, but the factors that affect the leaf wax distribution in fresh plant material, as well as in soils and sediments, are not yet fully understood and need further research. We systematically investigated the influence of vegetation and soil depth on leaf waxes in litter and topsoils along a European transect. The deciduous forest sites are often dominated by the n-C27 alkane and n-C28 alkanoic acid. Conifers produce few n-alkanes but show high abundances of the C24 n-alkanoic acid. Grasslands are characterized by relatively high amounts of C31 and C33 n-alkanes and C32 and C34 n-alkanoic acids. Chain length ratios thus may allow for distinguishing between different vegetation types, but caution must be exercised given the large species-specific variability in chain length patterns. An updated endmember model with the new n-alkane ratio (n-C31 + n-C33) / (n-C27 + n-C31 + n-C33) is provided to illustrate, and tentatively account for, degradation effects on n-alkanes.

  17. Modified paraffin wax for improvement of histological analysis efficiency.

    Science.gov (United States)

    Lim, Jin Ik; Lim, Kook-Jin; Choi, Jin-Young; Lee, Yong-Keun

    2010-08-01

    Paraffin wax is usually used as an embedding medium for histological analysis of natural tissue. However, it is not easy to obtain enough numbers of satisfactory sectioned slices because of the difference in mechanical properties between the paraffin and embedded tissue. We describe a modified paraffin wax that can improve the histological analysis efficiency of natural tissue, composed of paraffin and ethylene vinyl acetate (EVA) resin (0, 3, 5, and 10 wt %). Softening temperature of the paraffin/EVA media was similar to that of paraffin (50-60 degrees C). The paraffin/EVA media dissolved completely in xylene after 30 min at 50 degrees C. Physical properties such as the amount of load under the same compressive displacement, elastic recovery, and crystal intensity increased with increased EVA content. EVA medium (5 wt %) was regarded as an optimal composition, based on the sectioning efficiency measured by the numbers of unimpaired sectioned slices, amount of load under the same compressive displacement, and elastic recovery test. Based on the staining test of sectioned slices embedded in a 5 wt % EVA medium by hematoxylin and eosin (H&E), Masson trichrome (MT), and other staining tests, it was concluded that the modified paraffin wax can improve the histological analysis efficiency with various natural tissues. (c) 2010 Wiley-Liss, Inc.

  18. Wax solidification of drying agents containing tritiated water

    Energy Technology Data Exchange (ETDEWEB)

    Mishikawa, M.; Kido, H.

    1984-01-01

    It is necessary to immobilize the tritium not to give any impact on the environmental biosphere because tritium may give profound effects in the metabolic pathway. One of the most probable methods of immobilizing tritium would be incorporation of tritiated water in solid forms. Any drying or dehydration technique would be effective in a tritium cleanup system for off-gas streams containing tritium or tritiated water. Commonly used drying agents such as activated alumina, silica gel, molecular sieves and calcium sulfate are of value for removal of water vapour from air or other gases. For long term tritium storage, however, these adsorptive materials should be enveloped to prevent contact with water or water vapour because the rate of leaching, evaporation or diffusion of tritium from these porous materials is so large. The beeswax solidification method of the packed bed of drying agents adsorbing tritiated water is developed in this study, where the wax solidification procedure is performed by pouring the melt of wax into the void space of the packed bed of the drying agents and successive gradual cooling. The observed values of diffusivity or permeability of tritium in the wax solidified materials are about one-thousandth of those obtained for the cement block. Effect of coating on the rate of leaching is also discussed.

  19. Ultrasound assisted manufacturing of paraffin wax nanoemulsions: process optimization.

    Science.gov (United States)

    Jadhav, A J; Holkar, C R; Karekar, S E; Pinjari, D V; Pandit, A B

    2015-03-01

    This work reports on the process optimization of ultrasound-assisted, paraffin wax in water nanoemulsions, stabilized by modified sodium dodecyl sulfate (SDS). This work focuses on the optimization of major emulsification process variables including sonication time, applied power and surfactant concentration. The effects of these variables were investigated on the basis of mean droplet diameter and stability of the prepared emulsion. It was found that the stable emulsion with droplet diameters about 160.9 nm could be formed with the surfactant concentration of 10 mg/ml and treated at 40% of applied power (power density: 0.61 W/ml) for 15 min. Scanning electron microscopy (SEM) was used to study the morphology of the emulsion droplets. The droplets were solid at room temperature, showing bright spots under polarized light and a spherical shape under SEM. The electrophoretic properties of emulsion droplets showed a negative zeta potential due to the adsorption of head sulfate groups of the SDS surfactant. For the sake of comparison, paraffin wax emulsion was prepared via emulsion inversion point method and was checked its intrinsic stability. Visually, it was found that the emulsion get separated/creamed within 30 min. while the emulsion prepared via ultrasonically is stable for more than 3 months. From this study, it was found that the ultrasound-assisted emulsification process could be successfully used for the preparation of stable paraffin wax nanoemulsions.

  20. Next-Generation Electrochemical Energy Materials for Intermediate Temperature Molten Oxide Fuel Cells and Ion Transport Molten Oxide Membranes.

    Science.gov (United States)

    Belousov, Valery V

    2017-02-21

    High temperature electrochemical devices such as solid oxide fuel cells (SOFCs) and oxygen separators based on ceramic materials are used for efficient energy conversion. These devices generally operate in the temperature range of 800-1000 °C. The high operating temperatures lead to accelerated degradation of the SOFC and oxygen separator materials. To solve this problem, the operating temperatures of these electrochemical devices must be lowered. However, lowering the temperature is accompanied by decreasing the ionic conductivity of fuel cell electrolyte and oxygen separator membrane. Therefore, there is a need to search for alternative electrolyte and membrane materials that have high ionic conductivity at lower temperatures. A great many opportunities exist for molten oxides as electrochemical energy materials. Because of their unique electrochemical properties, the molten oxide innovations can offer significant benefits for improving energy efficiency. In particular, the newly developed electrochemical molten oxide materials show high ionic conductivities at intermediate temperatures (600-800 °C) and could be used in molten oxide fuel cells (MOFCs) and molten oxide membranes (MOMs). The molten oxide materials containing both solid grains and liquid channels at the grain boundaries have advantages compared to the ceramic materials. For example, the molten oxide materials are ductile, which solves a problem of thermal incompatibility (difference in coefficient of thermal expansion, CTE). Besides, the outstanding oxygen selectivity of MOM materials allows us to separate ultrahigh purity oxygen from air. For their part, the MOFC electrolytes show the highest ionic conductivity at intermediate temperatures. To evaluate the potential of molten oxide materials for technological applications, the relationship between the microstructure of these materials and their transport and mechanical properties must be revealed. This Account summarizes the latest results on

  1. Molten metal reactor and method of forming hydrogen, carbon monoxide and carbon dioxide using the molten alkaline metal reactor

    Science.gov (United States)

    Bingham, Dennis N.; Klingler, Kerry M.; Turner, Terry D.; Wilding, Bruce M.

    2012-11-13

    A molten metal reactor for converting a carbon material and steam into a gas comprising hydrogen, carbon monoxide, and carbon dioxide is disclosed. The reactor includes an interior crucible having a portion contained within an exterior crucible. The interior crucible includes an inlet and an outlet; the outlet leads to the exterior crucible and may comprise a diffuser. The exterior crucible may contain a molten alkaline metal compound. Contained between the exterior crucible and the interior crucible is at least one baffle.

  2. Molten Salt Breeder Reactor Analysis Methods

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jinsu; Jeong, Yongjin; Lee, Deokjung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2015-05-15

    Utilizing the uranium-thorium fuel cycle shows considerable potential for the possibility of MSR. The concept of MSBR should be revised because of molten salt reactor's advantage such as outstanding neutron economy, possibility of continuous online reprocessing and refueling, a high level of inherent safety, and economic benefit by keeping off the fuel fabrication process. For the development of MSR research, this paper provides the MSBR single-cell, two-cell and whole core model for computer code input, and several calculation results including depletion calculation of each models. The calculations are carried out by using MCNP6, a Monte Carlo computer code, which has CINDER90 for depletion calculation using ENDF-VII nuclear data. From the calculation results of various reactor design parameters, the temperature coefficients are all negative at the initial state and MTC becomes positive at the equilibrium state. From the results of core rod worth, the graphite control rod alone cannot makes the core subcritical at initial state. But the equilibrium state, the core can be made subcritical state only by graphite control rods. Through the comparison of the results of each models, the two-cell method can represent the MSBR core model more accurately with a little more computational resources than the single-cell method. Many of the thermal spectrum MSR have adopted a multi-region single-fluid strategy.

  3. Evaporation of Molten Salts by Plasma Torch

    Science.gov (United States)

    Putvinski, S.; Agnew, S. F.; Chamberlain, F.; Freeman, R. L.; Litvak, A.; Meekins, M.; Schwedock, T.; Umstadter, K. R.; Yung, S.; Bakharev, V.; Dresvin, S.; Egorov, S.; Feygenson, O.; Gabdullin, P.; Ivanov; Kizevetter, D.; Kostrukov, A.; Kuteev, B.; Malugin, V.; Zverev, S.

    2003-10-01

    Archimedes Technology Group is developing a plasma nuclear waste separation technology, called the Plasma Mass Filter. The experimental results on thermal evaporation of molten NaOH based surrogates for the Filter are presented. The main goal of the experiments was the study of high-density plasma discharges in NaOH vapor with the aim to minimize injection of additional working gas in the plasma torch. In these experiments NaOH vapor has been produced either by evaporation of the melt from a crucible introduced inside the plasma torch, or by injection of the melt droplets inside the torch. In the latter case, the melt was first atomized by an ultrasonic nebulizer at a flow rate of up to 2g/s with a droplet size of ˜50um. Plasma composition has been monitored by optical measurements. An optical diagnostic for droplet size measurement is presented together with results of the measurements of the size spectrum of the NaOH droplets.

  4. SPECIFIC HEAT CAPACITY AND THERMAL CONDUCTIVITY OF HEAT STORAGE MATERIALS BASED ON PARAFFIN, BROWN-COAL WAX AND POLYETHYLENE WAX

    Directory of Open Access Journals (Sweden)

    Snezhkin Yu.

    2014-08-01

    Full Text Available The present paper overviews heat storage materials (HSM with phase change based on organic compounds. They consist of paraffin, brown-coal wax and polyethylene wax. These materials are produced on an industrial scale for the foundry work. It is shown that heat capacity of HSM in the solid and liquid states can be used for heat storage in addition to the heat of phase change. The results of investigations of phase change during heating and cooling HSM are presented. The studies are carried out by differential scanning calorimetry (DSC. The measurement techniques of the specific heat capacity and the coefficient of thermal conductivity are shown. Temperature dependences of the specific heat capacity of HSM in the solid and liquid states are researched by DSC. Values of the coefficient of thermal conductivity are determined by contact stationary technique of the flat plate over the entire temperature range of the operation of heat storage system.

  5. Effect of selected physical properties of waxes on investments and casting shrinkage.

    Science.gov (United States)

    Ito, M; Yamagishi, T; Oshida, Y; Munoz, C A

    1996-02-01

    This study evaluated the relationship between flow characteristics, bending strength, and softening temperature of paraffin and dental inlay waxes to casting shrinkage when patterns were invested with a phosphate-bonded investment. This study found that the casting shrinkage decreased as the flow of the wax pattern increased. If a low flow wax is used or if there is a need for a thick pattern, the size of the casting ring should be increased. When wax patterns are formed for cast restorations, it is important to select the type of wax with the most desirable properties for the margin and the occlusal portions. Moreover, to accurately fabricate castings, it is necessary to understand the physical properties of the chosen waxes.

  6. Effect of waste wax and chain structure on the mechanical and physical properties of polyethylene

    Directory of Open Access Journals (Sweden)

    M.A. AlMaadeed

    2015-05-01

    The wax dispersion in the matrix strongly depends on the percentage of wax added to the polymer and the molecular structure of the polymer. It was found that increasing the wax content enhances the phase separation. LDPE undergoes less phase separation due to its highly branched structure composed of a network of short and long chain branches. The wax has no pronounced plasticising effect on the polymer. This is clearly manifested in LDPE as no change in the melting temperature occurred. LLDPE and HDPE were slightly affected by a high concentration of wax (30% and 40%. This is due to the non-uniform distribution of short chain branching along the LLDPE and HDPE main chains, which can interact with the wax structure.

  7. Wax esters of different compositions produced via engineering of leaf chloroplast metabolism in Nicotiana benthamiana.

    Science.gov (United States)

    Aslan, Selcuk; Sun, Chuanxin; Leonova, Svetlana; Dutta, Paresh; Dörmann, Peter; Domergue, Frédéric; Stymne, Sten; Hofvander, Per

    2014-09-01

    In a future bio-based economy, renewable sources for lipid compounds at attractive cost are needed for applications where today petrochemical derivatives are dominating. Wax esters and fatty alcohols provide diverse industrial uses, such as in lubricant and surfactant production. In this study, chloroplast metabolism was engineered to divert intermediates from de novo fatty acid biosynthesis to wax ester synthesis. To accomplish this, chloroplast targeted fatty acyl reductases (FAR) and wax ester synthases (WS) were transiently expressed in Nicotiana benthamiana leaves. Wax esters of different qualities and quantities were produced providing insights to the properties and interaction of the individual enzymes used. In particular, a phytyl ester synthase was found to be a premium candidate for medium chain wax ester synthesis. Catalytic activities of FAR and WS were also expressed as a fusion protein and determined functionally equivalent to the expression of individual enzymes for wax ester synthesis in chloroplasts.

  8. Dissipative particle dynamics simulations of the viscosities of molten TNT and molten TNT suspensions containing nanoparticles.

    Science.gov (United States)

    Zhou, Yang; Li, Yixue; Qian, Wen; He, Bi

    2016-09-01

    Based on dissipative particle dynamics (DPD) methods and experimental data, we used an empirical relationship between the DPD temperature and the real temperature to build a model that describes the viscosity of molten TNT fluids. The errors in the predicted viscosity based on this model were no more than 2.3 %. We also studied the steady-state shear rheological behavior of molten TNT fluids containing nanoparticles ("nanofluids"). The dependence of the nanofluid viscosity on the temperature was found to satisfy an Arrhenius-type equation, η = Ae (B/T) , where B, the flow activation energy, depends on particle content, size, and shape. We modified the Einstein-type viscosity model to account for the effects of nanoparticle solvation in TNT nanofluids. The resulting model was able to correctly predict the viscosities of suspensions containing nano- to microsized particles, and did not require any changes to the physical background of Einstein's viscosity theory. Graphical Abstract The revised Einstein viscosity model that correctly predict the viscosity of TNT suspensions containing nanoparticles.

  9. Supported Molten Metal Catalysis. A New Class of Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ravindra Datta; Ajeet Singh; Manuela Serban; Istvan Halasz

    2006-06-02

    We describe a new class of heterogeneous catalysts called supported molten metal catalysis (SMMC), in which molten metal catalysts are dispersed as nanodroplets on the surface of porous supports, allowing much larger active surface area than is possible in conventional contacting techniques for catalytic metals that are molten under reaction conditions, thus greatly enhancing their activity and potential utility. Specific examples of different types of reactions are provided to demonstrate the broad applicability of the technique in designing active, selective, and stable new catalysts. It is shown that dispersing the molten metal on a support in the suggested manner can enhance the rate of a reaction by three to four orders of magnitude as a result of the concomitant increase in the active surface area. New reaction examples include {gamma}-Al{sub 2}O{sub 3} supported molten Te (melting point 450 C) and Ga (MP 30 C) catalysts for bifunctional methylcyclohexane dehydrogenation. These catalysts provide activity similar to conventional Pt-based catalysts for this with better resistance to coking. In addition, results are described for a controlled pore glass supported molten In (MP 157 C) catalyst for the selective catalytic reduction of NO with ethanol in the presence of water, demonstrating activities superior to conventional catalysts for this reaction. A discussion is also provided on the characterization of the active surface area and dispersion of these novel supported catalysts. It is clear based on the results described that the development of new active and selective supported molten metal catalysts for practical applications is entirely plausible.

  10. Candle and candle wax containing metathesis and metathesis-like products

    Science.gov (United States)

    Murphy, Timothy A; Tupy, Michael J; Abraham, Timothy W; Shafer, Andy

    2014-04-01

    A wax comprises a metathesis product and/or a product that resembles, at least in part, a product which may be formed from a metathesis reaction. The wax may be used to form articles, for example, candles (container candles, votive candles, and/or a pillar candles), crayons, fire logs, or tarts. The wax commonly includes other components in addition to the metathesis product.

  11. Critical Involvement of Environmental Carbon Dioxide Fixation to Drive Wax Ester Fermentation in Euglena

    Science.gov (United States)

    Nishio, Kazuki; Nakazawa, Masami; Nakamoto, Masatoshi; Okazawa, Atsushi; Kanaya, Shigehiko; Arita, Masanori

    2016-01-01

    Accumulation profiles of wax esters in Euglena gracilis Z were studied under several environmental conditions. The highest amount of total wax esters accumulated under hypoxia in the dark, and C28 (myristyl-myristate, C14:0-C14:0) was prevalent among all conditions investigated. The wax ester production was almost completely suppressed under anoxia in the light, and supplying exogenous inorganic carbon sources restored wax ester fermentation, indicating the need for external carbon sources for the wax ester fermentation. 13C-labeling experiments revealed specific isotopic enrichment in the odd-numbered fatty acids derived from wax esters, indicating that the exogenously-supplied CO2 was incorporated into wax esters via the propionyl-CoA pathway through the reverse tricarboxylic acid (TCA) cycle. The addition of 3-mercaptopicolinic acid, a phosphoenolpyruvate carboxykinase (PEPCK) inhibitor, significantly affected the incorporation of 13C into citrate and malate as the biosynthetic intermediates of the odd-numbered fatty acids, suggesting the involvement of PEPCK reaction to drive wax ester fermentation. Additionally, the 13C-enrichment pattern of succinate suggested that the CO2 assimilation might proceed through alternative pathways in addition to the PEPCK reaction. The current results indicate that the mechanisms of anoxic CO2 assimilation are an important target to reinforce wax ester fermentation in Euglena. PMID:27669566

  12. Advances in research of paraffin wax appliance%石蜡应用研究进展

    Institute of Scientific and Technical Information of China (English)

    李振兴; 刘有智; 冯霞

    2011-01-01

    综述了国内外石蜡、乳化蜡的最新应用情况,分析了国内石蜡产业存在的问题,并展望了今后特种蜡的发展趋势和方向。%The latest application of paraffin wax and emulsifying wax are introduced at home and abroad in this paper,the problems of wax market is analyzed comprehensively,the direction and trend for development of special wax are also pointed out.

  13. Critical Involvement of Environmental Carbon Dioxide Fixation to Drive Wax Ester Fermentation in Euglena.

    Science.gov (United States)

    Padermshoke, Adchara; Ogawa, Takumi; Nishio, Kazuki; Nakazawa, Masami; Nakamoto, Masatoshi; Okazawa, Atsushi; Kanaya, Shigehiko; Arita, Masanori; Ohta, Daisaku

    Accumulation profiles of wax esters in Euglena gracilis Z were studied under several environmental conditions. The highest amount of total wax esters accumulated under hypoxia in the dark, and C28 (myristyl-myristate, C14:0-C14:0) was prevalent among all conditions investigated. The wax ester production was almost completely suppressed under anoxia in the light, and supplying exogenous inorganic carbon sources restored wax ester fermentation, indicating the need for external carbon sources for the wax ester fermentation. 13C-labeling experiments revealed specific isotopic enrichment in the odd-numbered fatty acids derived from wax esters, indicating that the exogenously-supplied CO2 was incorporated into wax esters via the propionyl-CoA pathway through the reverse tricarboxylic acid (TCA) cycle. The addition of 3-mercaptopicolinic acid, a phosphoenolpyruvate carboxykinase (PEPCK) inhibitor, significantly affected the incorporation of 13C into citrate and malate as the biosynthetic intermediates of the odd-numbered fatty acids, suggesting the involvement of PEPCK reaction to drive wax ester fermentation. Additionally, the 13C-enrichment pattern of succinate suggested that the CO2 assimilation might proceed through alternative pathways in addition to the PEPCK reaction. The current results indicate that the mechanisms of anoxic CO2 assimilation are an important target to reinforce wax ester fermentation in Euglena.

  14. Prediction Model Based on the Grey Theory for Tackling Wax Deposition in Oil Pipelines

    Institute of Scientific and Technical Information of China (English)

    Ming Wu; Shujuan Qiu; Jianfeng Liu; Ling Zhao

    2005-01-01

    Problems involving wax deposition threaten seriously crude pipelines both economically and operationally. Wax deposition in oil pipelines is a complicated problem having a number of uncertainties and indeterminations. The Grey System Theory is a suitable theory for coping with systems in which some information is clear and some is not, so it is an adequate model for studying the process of wax deposition.In order to predict accurately wax deposition along a pipeline, the Grey Model was applied to fit the data of wax deposition rate and the thickness of the deposited wax layer on the pipe-wall, and to give accurate forecast on wax deposition in oil pipelines. The results showed that the average residential error of the Grey Prediction Model is smaller than 2%. They further showed that this model exhibited high prediction accuracy. Our investigation proved that the Grey Model is a viable means for forecasting wax deposition.These findings offer valuable references for the oil industry and for firms dealing with wax cleaning in oil pipelines.

  15. Cuticular Waxes of Arabidopsis thaliana Shoots: Cell-Type-Specific Composition and Biosynthesis

    Directory of Open Access Journals (Sweden)

    Daniela Hegebarth

    2017-07-01

    Full Text Available It is generally assumed that all plant epidermis cells are covered with cuticles, and the distinct surface geometries of pavement cells, guard cells, and trichomes imply functional differences and possibly different wax compositions. However, experiments probing cell-type-specific wax compositions and biosynthesis have been lacking until recently. This review summarizes new evidence showing that Arabidopsis trichomes have fewer wax compound classes than pavement cells, and higher amounts of especially long-chain hydrocarbons. The biosynthesis machinery generating this characteristic surface coating is discussed. Interestingly, wax compounds with similar, long hydrocarbon chains had been identified previously in some unrelated species, not all of them bearing trichomes.

  16. Geological Conditions Favourable for High-Wax Oil Enrichment in Damintun Depression,Bohai Bay Basin

    Institute of Scientific and Technical Information of China (English)

    Zhu Fangbing

    2009-01-01

    The Damintun (大民屯) depression,a small (about 800 km2 in area) subunit in the Bohai (渤海) Bay basin,hosts nearly 2×108t of high-wax oils with wax contents up to 60%. The high-wax oils have high consolidation temperatures and viscosities.The high-wax oils were generated from the fourth member of the Shahejie Formation (Es4),which is also important source rocks for oils in other subunits of the Bohai Bay basin.Yet high-wax oils have not been found in significant volumes elsewhere in the Bohai Bay basin.Geological conditions favourable for high-wax oil enrichment were studied.This study shows that the unusual concentrations of high-wax oils in the depression seem to result from at least three different factors: (1) the presence of organic-matter rich source rocks which were prone to generate wax-rich hydrocarbons; (2) the formation of early overpressures which increased the expulsion efficiency of waxy hydrocarbons; and (3) reductions in subsidence rate and basal heat flows,which minimized the thermal cracking of high molecular-weight (waxy) hydrocarbons,and therefore prevented the high-wax oils from being transformed into less waxy equivalents.

  17. Intracuticular wax fixes and restricts strain in leaf and fruit cuticles.

    Science.gov (United States)

    Khanal, Bishnu Prasad; Grimm, Eckhard; Finger, Sebastian; Blume, Alfred; Knoche, Moritz

    2013-10-01

    This paper investigates the effects of cuticular wax on the release of strain and on the tensile properties of enzymatically isolated cuticular membranes (CMs) taken from leaves of agave (Agave americana), bush lily (Clivia miniata), holly (Ilex aquifolium), and ivy (Hedera helix) and from fruit of apple (Malus × domestica), pear (Pyrus communis), and tomato (Lycopersicon esculentum). Biaxial strain release was quantified as the decrease in CM disc area following wax extraction. Stiffness, maximum strain and maximum force were determined in uniaxial tensile tests using strips of CM and dewaxed CMs (DCMs). Biaxial strain release, stiffness, and maximum strain, but not maximum force, were linearly related to the amount of wax extracted. Apple CM has the most wax and here the effect of wax extraction was substantially accounted for by the embedded cuticular wax. Heating apple CM to 80°C melted some wax constituents and produced an effect similar to, but smaller than, that resulting from wax extraction. Our results indicate that wax 'fixes' strain, effectively converting reversible elastic into irreversible plastic strain. A consequence of 'fixation' is increased cuticular stiffness.

  18. LIFE Materails: Molten-Salt Fuels Volume 8

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R; Brown, N; Caro, A; Farmer, J; Halsey, W; Kaufman, L; Kramer, K; Latkowski, J; Powers, J; Shaw, H; Turchi, P

    2008-12-11

    The goals of the Laser Inertial Fusion Fission Energy (LIFE) is to use fusion neutrons to fission materials with no enrichment and minimum processing and have greatly reduced wastes that are not of interest to making weapons. Fusion yields expected to be achieved in NIF a few times per day are called for with a high reliable shot rate of about 15 per second. We have found that the version of LIFE using TRISO fuel discussed in other volumes of this series can be modified by replacing the molten-flibe-cooled TRISO fuel zone with a molten salt in which the same actinides present in the TRISO particles are dissolved in the molten salt. Molten salts have the advantage that they are not subject to radiation damage, and hence overcome the radiation damage effects that may limit the lifetime of solid fuels such as TRISO-containing pebbles. This molten salt is pumped through the LIFE blanket, out to a heat exchanger and back into the blanket. To mitigate corrosion, steel structures in contact with the molten salt would be plated with tungsten or nickel. The salt will be processed during operation to remove certain fission products (volatile and noble and semi-noble fission products), impurities and corrosion products. In this way neutron absorbers (fission products) are removed and neutronics performance of the molten salt is somewhat better than that of the TRISO fuel case owing to the reduced parasitic absorption. In addition, the production of Pu and rare-earth elements (REE) causes these elements to build up in the salt, and leads to a requirement for a process to remove the REE during operation to insure that the solubility of a mixed (Pu,REE)F3 solid solution is not exceeded anywhere in the molten salt system. Removal of the REE will further enhance the neutronics performance. With molten salt fuels, the plant would need to be safeguarded because materials of interest for weapons are produced and could potentially be removed.

  19. Gasification characteristics of organic waste by molten salt

    Science.gov (United States)

    Sugiura, Kimihiko; Minami, Keishi; Yamauchi, Makoto; Morimitsu, Shinsuke; Tanimoto, Kazumi

    Recently, along with the growth in economic development, there has been a dramatic accompanying increase in the amount of sludge and organic waste. The disposal of such is a significant problem. Moreover, there is also an increased in the consumption of electricity along with economic growth. Although new energy development, such as fuel cells, has been promoted to solve the problem of power consumption, there has been little corresponding promotion relating to the disposal of sludge and organic waste. Generally, methane fermentation comprises the primary organic waste fuel used in gasification systems. However, the methane fermentation method takes a long time to obtain the fuel gas, and the quality of the obtained gas is unstable. On the other hand, gasification by molten salt is undesirable because the molten salt in the gasification gas corrodes the piping and turbine blades. Therefore, a gasification system is proposed by which the sludge and organic waste are gasified by molten salt. Moreover, molten carbonate fuel cells (MCFC) are needed to refill the MCFC electrolyte volatilized in the operation. Since the gasification gas is used as an MCFC fuel, MCFC electrolyte can be provided with the fuel gas. This paper elucidates the fundamental characteristics of sludge and organic waste gasification. A crucible filled with the molten salt comprising 62 Li 2CO 3/38 K 2CO 3, is installed in the reaction vessel, and can be set to an arbitrary temperature in a gas atmosphere. In this instance, the gasifying agent gas is CO 2. Sludge or the rice is supplied as organic waste into the molten salt, and is gasified. The chemical composition of the gasification gas is analyzed by a CO/CO 2 meter, a HC meter, and a SO x meter gas chromatography. As a result, although sludge can generate CO and H 2 near the chemical equilibrium value, all of the sulfur in the sludge is not fixed in the molten salt, because the sludge floats on the surface of the carbonate by the specific

  20. Overview on CO2 valorisation: challenge of molten carbonates

    Directory of Open Access Journals (Sweden)

    Déborah eChery

    2015-10-01

    Full Text Available The capture and utilisation of CO2 is becoming progressively one of the significant challenges in the field of energetic resources. Whatever the energetic device, it is impossible to avoid completely the production of greenhouse gas, even parting from renewable energies. Transforming CO2 in a valuable fuel, such as alcohols, CO or even C, could constitute a conceptual revolution in the energetic bouquet offering a huge application domain. Although several routes have been tested for this purpose, on which a general panorama will be given here, molten carbonates are attracting a renewed interest aiming at dissolving and reducing carbon dioxide in such melts. Because of their unique properties, molten carbonates are already used as electrolytes in molten carbonate fuel cells; they can also provoke a breakthrough in a new economy considering CO2 as an energetic source rather than a waste. Molten carbonates science and technology is becoming a strategic field of research for energy and environmental issues. Our aim in this review is to put in evidence the benefits of molten carbonates to valorise CO2 and to show that it is one of the most interesting routes for such application.

  1. Viscosity of molten lithium, thorium and beryllium fluorides mixtures

    Science.gov (United States)

    Merzlyakov, Alexander V.; Ignatiev, Victor V.; Abalin, Sergei S.

    2011-12-01

    Considering development of Molten Salt Fast Reactor (MSFR) concept, following Molten Salt fluorides mixtures have been chosen as an object for viscosity studies in this work (in mol%): 78LiF-22ThF 4; 71LiF-27ThF 4-2BeF 2 and 75LiF-20ThF 4-5BeF 2. Additionally, the effect of the 3 mol% CeF 3 additives on viscosity of the molten 75LiF-20ThF 4-5BeF 2 (mol%) salt mixture has been investigated experimentally. The method of torsional oscillations of cylindrical crucible filled by molten fluorides mixture has been chosen for kinematic viscosity measurement at temperatures up to 800-850 °C. In temperature ranges, where melts behave as normal liquids, dependences on viscosity vs. temperature are received: ν = А exp [B/T(K)], where ν - kinematic viscosity, m 2/s; T - temperature, K. The kinematic viscosity Rout mean squares (RMS) estimated in the assumption about dispersion homoscedasticity is (0.04-0.12) × 10 -6 (m 2/s). Discrepancies left in the data of viscosity for molten mixtures of LiF, BeF 2 and ThF 4 received by different researchers need further investigations in this area to be continued.

  2. Evaluation of Wax Deposition and Its Control During Production of Alaska North Slope Oils

    Energy Technology Data Exchange (ETDEWEB)

    Tao Zhu; Jack A. Walker; J. Liang

    2008-12-31

    Due to increasing oil demand, oil companies are moving into arctic environments and deep-water areas for oil production. In these regions of lower temperatures, wax deposits begin to form when the temperature in the wellbore falls below wax appearance temperature (WAT). This condition leads to reduced production rates and larger pressure drops. Wax problems in production wells are very costly due to production down time for removal of wax. Therefore, it is necessary to develop a solution to wax deposition. In order to develop a solution to wax deposition, it is essential to characterize the crude oil and study phase behavior properties. The main objective of this project was to characterize Alaskan North Slope crude oil and study the phase behavior, which was further used to develop a dynamic wax deposition model. This report summarizes the results of the various experimental studies. The subtasks completed during this study include measurement of density, molecular weight, viscosity, pour point, wax appearance temperature, wax content, rate of wax deposition using cold finger, compositional characterization of crude oil and wax obtained from wax content, gas-oil ratio, and phase behavior experiments including constant composition expansion and differential liberation. Also, included in this report is the development of a thermodynamic model to predict wax precipitation. From the experimental study of wax appearance temperature, it was found that wax can start to precipitate at temperatures as high as 40.6 C. The WAT obtained from cross-polar microscopy and viscometry was compared, and it was discovered that WAT from viscometry is overestimated. From the pour point experiment it was found that crude oil can cease to flow at a temperature of 12 C. From the experimental results of wax content, it is evident that the wax content in Alaskan North Slope crude oil can be as high as 28.57%. The highest gas-oil ratio for a live oil sample was observed to be 619.26 SCF

  3. Laser-assisted fabrication of batteries on wax paper

    Science.gov (United States)

    Chitnis, G.; Tan, T.; Ziaie, B.

    2013-11-01

    The functionality of paper-based diagnostic devices can be significantly enhanced by their integration with an on-board energy source. Here, we demonstrate the fabrication of paper-based electrochemical cells on wax paper using CO2 laser surface treatment and micromachining. A four cell zinc-copper battery shows a steady open-circuit voltage of ˜3 V and can provide 0.25 mA for at least 30 min when connected to a 10 kΩ load. Higher voltages and current values can be obtained by adjusting the number and size of electrochemical cells in the battery without changing the fabrication process.

  4. DDT Behavior of Waxed Mixtures of RDX, HMX, and Tetryl

    Science.gov (United States)

    1977-10-18

    NSWC/WOL TR 77-96 O DDT BEHAVIOR OF WAXED MIXTURES OF " RDX, HMX, AND TETRYL BY DONNA PRICE and RICHARD R. BERNECKER RESEARCH AND TECHNOLOGY...50.95 mm OD) with heavy end closures was used. A B/ KNO3 ignitor (1) was used to ignite one end of the 295.4 mm explosive column. Charge loading, tube...data reduction are also as in reference 1 with the modification for strain gages given in reference 2. I. R. R. Bernecker and D. Price , "Transition

  5. Properties of Cookies Made with Natural Wax-Vegetable Oil Organogels.

    Science.gov (United States)

    Hwang, Hong-Sik; Singh, Mukti; Lee, Suyong

    2016-05-01

    The aim of this study was to examine the feasibility of cookies in which the conventional margarine is replaced with an organogel of vegetable oil (VO) and natural wax. New cookies from VO organogels contain no trans fats and much less saturated fats than cookies made with a conventional margarine. To understand the effects of different kinds of waxes, organogels were prepared from 4 different waxes including sunflower wax (SW), rice bran wax (RBW), beeswax, and candelilla wax and properties of cookie dough and cookie were evaluated. To investigate the effects of different VOs on the properties of cookies, 3 VOs including olive oil, soybean oil and flaxseed oil representing oils rich in oleic acid (18:1), linoleic acid (18:2), and linolenic acid (18:3), respectively, were used. Both the wax and VO significantly affected properties of organogel such as firmness and melting behavior shown in differential scanning calorimetry. The highest firmness of organogel was observed with SW and flaxseed oil. Properties of dough such as hardness and melting behavior were also significantly affected by wax and VO while trends were somewhat different from those for organogels. SW and RBW provided greatest hardnesses to cookie dough. However, hardness, spread factor, and fracturability of cookie containing the wax-VO organogel were not significantly affected by different waxes and VOs. Several cookies made with wax-VO organogels showed similar properties to cookies made with a commercial margarine. Therefore, this study shows the high feasibility of utilization of the organogel technology in real foods such as cookies rich in unsaturated fats.

  6. Economics of comb wax salvage by the red dwarf honeybee, Apis florea.

    Science.gov (United States)

    Pirk, Christian W W; Crous, Kendall L; Duangphakdee, Orawan; Radloff, Sarah E; Hepburn, Randall

    2011-04-01

    Colonies of Apis florea, which only abscond a short distance, usually return to salvage old nest wax; but, those colonies, and all other honeybee species which go considerably further, do not. Wax salvage would clearly be counter-productive unless the energy input/energy yield threshold was a profitable one. There are two possible trade-offs in this scenario, the trade-off between the energy expended to recover the wax (recovering hypothesis) as against that of replacing the wax by new secretion (replacing hypothesis). In order to compare the two hypotheses, the fuel costs involved in salvaging wax on one return trip, the average flower handling time, flight time and relative values for substituting the salvaged wax with nectar were calculated. Moreover, the energy value of the wax was determined. Net energy gains for salvaged wax were calculated. The energy value of the salvaged wax was 42.7 J/mg, thus too high to be the limiting factor since salvaging costs are only 642.76 mJ/mg (recovering hypothesis). The recovery costs (642.76 mJ/mg) only fall below the replacement costs for absconding distance below 115 m thus supporting the replacing hypothesis. This energetic trade-off between replacing and recycling plus the small absconding range of A. florea might explain why A. florea is probably the only honeybee species known to salvage wax and it parsimoniously explains the underlying reasons why A. florea only salvages wax from the old nest if the new nesting site is less than 100-200 m away-energetically, it pays off to recycle.

  7. The benefits of Fischer-Tropsch waxes in synthetic petroleum jelly.

    Science.gov (United States)

    Bekker, M; Louw, N R; Jansen Van Rensburg, V J; Potgieter, J

    2013-02-01

    This article is an introduction and general discussion regarding the use of Fisher-Tropsch wax in petroleum jelly applications. Traditionally, petroleum jelly is prepared from a blend of microwax, paraffin wax and mineral oil that are all derived from crude oil. Sasol Wax has successfully prepared a petroleum jelly based on predominantly to fully synthetic Fisher-Tropsch wax. Sasol Wax was awarded a patent P53898ZP00-29 November 11 for a predominantly to fully synthetic petroleum jelly based on Fisher-Tropsch wax blends. The benefits of Fisher-Tropsch wax discussed in this article include the absence of aromatic compounds and polycyclic aromatic compounds in Fisher-Tropsch wax as well as the sustainable production that is possible with Fisher-Tropsch wax, as opposed to paraffin wax that may be affected by the closure of group I Base Oil plants. This article will be the first in a series of articles from the same authors, and follow-up articles will include solid-state nuclear magnetic resonance and crystallization studies to determine the influence of predominantly synthetic waxes on petroleum jelly network structures compared with more traditional mineral oil-derived petroleum jellies, final product performance and stability of synthetic petroleum jelly used in, for example, personal care lotions or creams. The influence of oxygenated compounds and product safety and rheological properties (including primary skin feel upon application and secondary skin feel after application) of synthetic petroleum jellies compared with traditional mineral oil-derived petroleum jellies are discussed. © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  8. Co-pyrolysis of hydrothermally upgraded brown coal and wax prepared from waste plastics

    Energy Technology Data Exchange (ETDEWEB)

    Kouichi Miura; Susan A. Roces; Monthicha Pattatapanusak; Hiroyuki Nakagawa; Ryuichi Ashida; Masato Morimoto [Kyoto University, Kyoto (Japan). Department of Chemical Engineering

    2007-07-01

    We have recently presented a hydrothermal extraction method that not only removes water from brown coal but also upgrades the coal and extracts low molecular mass compounds simultaneously. The upgraded coal contained much less oxygen than the raw coal. However, it still needs to be further upgraded to be utilized as a substitute for bituminous coal. In this study co-pyrolysis of the upgraded coals and waxes formed from waste plastics was investigated for this purpose. Waxes were prepared through pyrolysis of polyethylene, polypropylene, and polyethylene terephtalate. Upgraded coals were then impregnated with the waxes in an autoclave at 200{sup o}C under pressure. The mixtures of coal and wax were rapidly heated up to 1040{sup o}C at about 3000{sup o}C/s using a Curie point pyrolyzer in an inert atmosphere. The char yield was greatly enhanced by a factor of 1.1 to 1.3 compared to the char yield obtained when the upgraded coals and waxes were pyrolyzed independently. Even under a slower heating rate (0.17{sup o}C/s) the char yields increased by a factor of 1.2 for the all mixtures of the upgraded coal and waxes. Since no such effect was found when the raw brown coal was impregnated with waxes, it was suggested that the modification of the structure of brown coal by the hydrothermal extraction could enhance interactions between the coal and the wax when co-pyrolyzed. Effect of wax mixing ratio on co-pyrolysis behavior was also examined. The char yield dramatically increased when the ratio exceeded about 0.3 g/g for the pyrolysis of both under slow and rapid heating rates. This trend coincided with that of the swelling ratio of the upgraded coal impregnated with wax, indicating that some physical change by wax-impregnation affected the co-pyrolysis behavior. 5 refs., 14 figs., 3 tabs.

  9. Paraffin wax emulsion for increased rainfastness of insecticidal bait to control Rhagoletis pomonella (Diptera: Tephritidae).

    Science.gov (United States)

    Teixeira, Luís A F; Wise, John C; Gut, Larry J; Isaacs, Rufus

    2009-06-01

    In regions with a humid summer climate, the use of water-soluble bait to control apple maggot is often limited by rainfall. We studied increasing the rainfastness of GF-120 fruit fly bait by adding paraffin wax emulsion. First, we verified that adding 10% wax to a mixture containing 16.7% GF-120 did not reduce the mortality of female apple maggot compared with GF-120 without wax. In addition, we determined that fly mortality caused by GF-120 plus wax subjected to simulated rain was similar to that caused by GF-120 without wax not subjected to rain. Other assays showed that higher fly mortality resulted from increasing the proportion of wax from 10 to 15%, and lower mortality resulted from decreasing GF-120 from 16.7 to 10 or 5%. The availability of spinosad on or near droplets of a mixture consisting of 5, 10, or 15% GF-120 and 15% wax was determined before and after the droplets were subjected to three 15-min periods of simulated rain. We found an initial steep decline in dislodgeable spinosad and smaller decreases after subsequent periods of rain. In a small-plot field trial, fruit infestation by apple maggot in plots treated with a mixture consisting of 16.7% GF-120 and 19.2% wax was less than in plots treated with 16.7% GF-120 without wax but not less than in control plots. Overall, we found that adding paraffin wax emulsion to GF-120 increased rainfastness in laboratory bioassays, and specifically that it retained the active ingredient spinosad. However, our field data suggest that optimal rainfastness requires the development of mixtures with > 19.2% wax, which may preclude application using standard spray equipment.

  10. Synthesis of oleyl oleate wax esters in Arabidopsis thaliana and Camelina sativa seed oil.

    Science.gov (United States)

    Iven, Tim; Hornung, Ellen; Heilmann, Mareike; Feussner, Ivo

    2016-01-01

    Seed oil composed of wax esters with long-chain monoenoic acyl moieties represents a high-value commodity for industry. Such plant-derived sperm oil-like liquid wax esters are biodegradable and can have excellent properties for lubrication. In addition, wax ester oil may represent a superior substrate for biodiesel production. In this study, we demonstrate that the low-input oil seed crop Camelina sativa can serve as a biotechnological platform for environmentally benign wax ester production. Two biosynthetic steps catalysed by a fatty alcohol-forming acyl-CoA reductase (FAR) and a wax ester synthase (WS) are sufficient to achieve wax ester accumulation from acyl-CoA substrates. To produce plant-derived sperm oil-like liquid wax esters, the WS from Mus musculus (MmWS) or Simmondsia chinensis (ScWS) were expressed in combination with the FAR from Mus musculus (MmFAR1) or Marinobacter aquaeolei (MaFAR) in seeds of Arabidopsis thaliana and Camelina sativa. The three analysed enzyme combinations Oleo3:mCherry:MmFAR1∆c/Oleo3:EYFP:MmWS, Oleo3:mCherry:MmFAR1∆c/ScWS and MaFAR/ScWS showed differences in the wax ester molecular species profiles and overall biosynthetic performance. By expressing MaFAR/ScWS in Arabidopsis or Camelina up to 59% or 21% of the seed oil TAGs were replaced by wax esters, respectively. This combination also yielded wax ester molecular species with highest content of monounsaturated acyl moieties. Expression of the enzyme combinations in the Arabidopsis fae1 fad2 mutant background high in oleic acid resulted in wax ester accumulation enriched in oleyl oleate (18:1/18:1 > 60%), suggesting that similar values may be obtained with a Camelina high oleic acid line.

  11. Presence of Li Clusters in Molten LiCl-Li

    Science.gov (United States)

    Merwin, Augustus; Phillips, William C.; Williamson, Mark A.; Willit, James L.; Motsegood, Perry N.; Chidambaram, Dev

    2016-05-01

    Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. In the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. This observation is indicative of a nanofluid type colloidal suspension of Li8 in a molten salt matrix. It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable.

  12. Features of molten pool free surface in laser processing

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    On the basis of static characteristics of free surface of molten pools in laser processing, starting with the change of surface tension, the uniform numerical models are developed for both the liquid and solid regions of metals by applying the enthalpy source method and the porous region model. The flow and heat transfer characteristics in the molten pools and the distribution of surface tension on free surface are disclosed. The shape of free surface is analyzed by considering the static forces on the free surface and by combining with the calculated results of the molten pool. The model is applied to analyzing the laser processing of AISI 304 stainless steel, and the effects of different processing tech nics and material properties on shaping of free surface are discussed.

  13. Plasma-sprayed ceramic coatings for molten metal environments.

    Energy Technology Data Exchange (ETDEWEB)

    Hollis, K. J. (Kendall J.); Peters, M. I. (Maria I.); Bartram, B. D. (Brian D.)

    2002-01-01

    Coating porosity is an important parameter to optimize for plasma-sprayed ceramics which are intended for service in molten metal environments. Too much porosity and the coatings may be infiltrated by the molten metal causing corrosive attack of the substrate or destruction of the coating upon solidification of the metal. Too little porosity and the coating may fail due to its inability to absorb thermal strains. This study describes the testing and analysis of tungsten rods coated with aluminum oxide, yttria-stabilized zirconia, yttrium oxide, and erbium oxide deposited by atmospheric plasma spraying. The samples were immersed in molten aluminum and analyzed after immersion. One of the ceramic materials used, yttrium oxide, was heat treated at 1000 C and 2000 C and analyzed by X-ray diffractography and mercury intrusion porosimetry. Slight changes in crysl nl structure and significant changes in porosity were observed after heat treatments.

  14. Molten salt reactor: Deterministic safety evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Merle-Lucotte, Elsa; Heuer, Daniel; Mathieu, Ludovic; Le Brun, Christian [Laboratory for Subatomic Physics and Cosmology (LPSC), 53, Avenue des Marthyrs, F-38026 Grenoble (France)

    2006-07-01

    Molten Salt Reactors (MSRs) are one of the systems retained by Generation IV as a candidate for the next generation of nuclear reactors. This type of reactor is particularly well adapted to the thorium fuel cycle (Th- {sup 233}U) which has the advantage of producing less minor actinides than the uranium-plutonium fuel cycle ({sup 238}U- {sup 239}Pu). In the frame of a major re-evaluation of the MSR concept and concentrating on some major constraints such as feasibility, breeding capability and, above all, safety, we have considered a particular reactor configuration that we call the 'unique channel' configuration in which there is no moderator in the core, leading to a quasi fast neutron spectrum. This reactor is presented in the first section. MSRs benefit from several specific advantages which are listed in a second part of this work. Beyond these advantages of the MSR, the level of the deterministic safety in such a reactor has to be assessed precisely. In a third section, we first draw up a list of the reactivity margins in our reactor configuration. We then define and quantify the parameters characterizing the deterministic safety of any reactor: the fraction of delayed neutrons, and the system's feedback coefficients that are here negative. Finally, using a simple point-kinetic evaluation, we analyze how these safety parameters impact the system when the total reactivity margins are introduced in the MSR. The results of this last study are discussed, emphasizing the satisfactory behavior of the MSR and the excellent level of deterministic safety which can be achieved. This work is based on the coupling of a neutron transport code called MCNP with a materials evolution code. The former calculates the neutron flux and the reaction rates in all the cells while the latter solves the Bateman equations for the evolution of the materials composition within the cells. These calculations take into account the input parameters (power released

  15. Renewing Liquid Fueled Molten Salt Reactor Research and Development

    Science.gov (United States)

    Towell, Rusty; NEXT Lab Team

    2016-09-01

    Globally there is a desperate need for affordable, safe, and clean energy on demand. More than anything else, this would raise the living conditions of those in poverty around the world. An advanced reactor that utilizes liquid fuel and molten salts is capable of meeting these needs. Although, this technology was demonstrated in the Molten Salt Reactor Experiment (MSRE) at ORNL in the 60's, little progress has been made since the program was cancelled over 40 years ago. A new research effort has been initiated to advance the technical readiness level of key reactor components. This presentation will explain the motivation and initial steps for this new research initiative.

  16. Fabrication of catalytic electrodes for molten carbonate fuel cells

    Science.gov (United States)

    Smith, James L.

    1988-01-01

    A porous layer of catalyst material suitable for use as an electrode in a molten carbonate fuel cell includes elongated pores substantially extending across the layer thickness. The catalyst layer is prepared by depositing particulate catalyst material into polymeric flocking on a substrate surface by a procedure such as tape casting. The loaded substrate is heated in a series of steps with rising temperatures to set the tape, thermally decompose the substrate with flocking and sinter bond the catalyst particles into a porous catalytic layer with elongated pores across its thickness. Employed as an electrode, the elongated pores provide distribution of reactant gas into contact with catalyst particles wetted by molten electrolyte.

  17. Molten pool and temperature field in CO2 laser welding

    Institute of Scientific and Technical Information of China (English)

    Duan Aiqin; Chen Li; Wang Yajun; Hu Lunji

    2006-01-01

    Two measuring methods, high-speed camera and optical monitoring system, were used to study processes of laser welding. Molten pool, cooling time and temperature field were analyzed based on real measured images and optical signal data. The results show that the width of molten pool is almost equal to the width of weld, and length is about 7.8 mm. The solidification time is about 0. 5 s and the temperature gradient is great, so HAZ is very small. The method and results will be of benefit to build the relationship between welding parameters and microstructure.

  18. Surface Tension of Molten Ni and Ni-Co Alloys

    Institute of Scientific and Technical Information of China (English)

    Feng XIAO; Liang FANG; Kiyoshi NOGI

    2005-01-01

    Surface tension of molten Ni and Ni-Co (5 and 10 mass fraction) alloys was measured at the temperature range of 1773~1873 K using an improved sessile drop method with an alumina substrate in an Ar+3%H2 atmosphere. The error of the data obtained was analyzed. The surface tension of molten Ni and Ni-Co (5 and 10 mass fraction) alloys decreases with increasing temperature. The influence of Co on the surface tension of Ni-Co alloys is little in the studied Co concentration range.

  19. Electrochemical studies on cerium(Ⅲ) in molten fluoride mixtures

    Institute of Scientific and Technical Information of China (English)

    VIRGIL; CONSTANTIN; ANA-MARIA; POPESCU; MIRCEA; OLTEANU

    2010-01-01

    This study aims to determine the principal electrochemical characteristics of the electrodeposition of cerium metal from molten fluoride systems.The cathodic process of Ce3+ ions in LiF-NaF and LiF-NaF-CaF2 molten salts was studied using electrochemical techniques as steady state and cyclic voltammetry methods.The decomposition potential(Ed) and the overvoltage(η) were determined for NaCeF4 using current-potential curves under galvanostatic conditions.The Ed was found to be 2.025 V in LiF-NaF and 2.045 V in...

  20. Stabilization of STEP electrolyses in lithium-free molten carbonates

    CERN Document Server

    Licht, Stuart

    2012-01-01

    This communication reports on effective electrolyses in lithium-free molten carbonates. Processes that utilize solar thermal energy to drive efficient electrolyses are termed Solar Thermal Electrochemical Processes (STEP). Lithium-free molten carbonates, such as a sodium-potassium carbonate eutectic using an iridium anode, or a calcium-sodium-potassium carbonate eutectic using a nickel anode, can provide an effective medium for STEP electrolyses. Such electrolyses are useful in STEP carbon capture, and the production of staples including STEP fuel, iron, and cement.

  1. Fast Thorium Molten Salt Reactors started with Plutonium

    OpenAIRE

    Merle-Lucotte, E.; Heuer, D.; Le Brun, C.; Mathieu, L.; Brissot, R.; Liatard, E.; Méplan, O.; Nuttin, A.

    2006-01-01

    One of the pending questions concerning Molten Salt Reactors based on the 232Th/233U fuel cycle is the supply of the fissile matter, and as a consequence the deployment possibilities of a fleet of Molten Salt Reactors, since 233U does not exist on earth and is not yet produced in the current operating reactors. A solution may consist in producing 233U in special devices containing Thorium, in Pressurized Water or Fast Neutrons Reactors. Two alternatives to produce 233U are examined here: dire...

  2. Castable Cement Can Prevent Molten-Salt Corrosion in CSP

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    NREL's study demonstrated that castable cements on metals are a protective barrier that can prevent permeation of molten salts toward metallic surfaces. The silica-based castable cement Aremco 645-N, when sprayed with boron nitride, can protect containment metallic alloys from attack by molten chlorides at high temperatures (650 degrees C) in short-term tests. Improved thermal energy storage technology could increase the performance of CSP and reduce costs, helping to reach the goal of the U.S. Department of Energy's SunShot Initiative to make solar cost-competitive with other non-renewable sources of electricity by 2020.

  3. Nuclear Hybrid energy Systems: Molten Salt Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.; Sabharwall, P.; Yoon, S. J.; Bragg-Sitton, S. B.; Stoot, C.

    2014-07-01

    Without growing concerns in reliable energy supply, the next generation in reliable power generation via hybrid energy systems is being developed. A hybrid energy system incorporates multiple energy input source sand multiple energy outputs. The vitality and efficiency of these combined systems resides in the energy storage application. Energy storage is necessary for grid stabilization because stored excess energy is used later to meet peak energy demands. With high thermal energy production the primary nuclear heat generation source, molten salt energy storage is an intriguing option because of its distinct thermal properties. This paper discusses the criteria for efficient energy storage and molten salt energy storage system options for hybrid systems. (Author)

  4. SENER molten salt tower technology. Ouarzazate NOOR III case

    Science.gov (United States)

    Relloso, Sergio; Gutiérrez, Yolanda

    2017-06-01

    NOOR III 150 MWe project is the evolution of Gemasolar (19.9 MWe) to large scale Molten Salt Tower plants. With more than 5 years of operational experience, Gemasolar lessons learned have been the starting point for the optimization of this technology, considered the leader of potential cost reduction in CSP. In addition, prototypes of plant key components (heliostat and receiver) were manufactured and thoroughly tested before project launch in order to prove the new engineering solutions adopted. The SENER proprietary technology of NOOR III will be applied in the next Molten Salt Tower plants that will follow in other countries, such as South Africa, Chile and Australia.

  5. Molten Triazolium Chloride Systems as New Aluminum Battery Electrolytes

    DEFF Research Database (Denmark)

    Vestergaard, B.; Bjerrum, Niels; Petrushina, Irina

    1993-01-01

    The possibility of using molten mixtures of 1,4-dimethyl-1,2,4-triazolium chloride (DMTC) and aluminum chloride (AlCl3) as secondary battery electrolytes was studied, in some cases extended by the copresence of sodium chloride. DMTC-AlCl, mixtures demonstrated high specific conductivity in a wide...... of milliamperes per square centimeter) was observed at 0.344 V on the acidic sodium tetrachloroaluminate background, involving a free triazolium radical mechanism. Molten DMTC-AlCl3 electrolytes are acceptable for battery performance and both the aluminum anode and the triazolium electrolyte can be used as active...

  6. Analysis of sorghum wax and carnauba wax by reversed phase liquid chromatography mass spectrometry

    Science.gov (United States)

    Sorghum is a genus in the grass family, which is used for both grain and forage production throughout the world. In the United States, sorghum grain is predominantly used as livestock feed, and in ethanol production. In recent years however, sorghum grain has been investigated for other industrial a...

  7. Impact of changing wax type during storage on mandarin flavor and quality attributes

    Science.gov (United States)

    Mandarin (Citrus reticulata Blanco) packers sometimes apply a storage wax (SW) designed to limit water loss during the initial part of storage and then replace it with a higher shine pack wax (PW) prior to shipment of the fruit. Mandarins are prone to the development of off-flavors as a result of lo...

  8. Dental wax impressions of plant tissues for viewing with scanning electron microscopy (SEM).

    Science.gov (United States)

    Beermann, Anke; Hülskamp, Martin

    2010-09-01

    Scanning electron microscopy (SEM) is a valuable method for examining surface structures. Taking wax impressions of plant structures, such as leaves, is a nondestructive procedure that makes it possible to view changes in surface structures over time, such as during development. This protocol describes a method for making dental wax impressions of plant tissues.

  9. Gelling ability and crystal morphology of sunflower wax in soybean oil

    Science.gov (United States)

    Plant waxes can effectively form organogels with vegetable oils and these organogels have drawn considerable interests as alternatives to solid fats containing trans fats and saturated fats in margarines and spreads. Among them sunflower wax showed the most pronounced gelling ability. In an attempt ...

  10. MODELING OF THE FAST ORGANIC EMISSIONS FROM A WOOD-FINISHING PRODUCT -- FLOOR WAX

    Science.gov (United States)

    The paper discusses environmental chamber and full-scale residential house tests conducted to characterize the fast organic emissions from a wood finishing product, floor wax. For the environmental chamber tests, a very small amount (wax was applied to an alumi...

  11. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery

    Directory of Open Access Journals (Sweden)

    Thomas M. Attard

    2015-07-01

    Full Text Available To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM for maize stover wax extraction was found to be €88.89 per kg of wax, with the fixed capital investment (FCI and utility costs (CUT contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of €10.87 per kg of wax (based on 27% combustion efficiency for electricity generation and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation. A sensitivity analysis study showed that utility costs (cost of electricity had the greatest effect on the COM.

  12. pH-sensitive wax emulsion copolymerization with acrylamide hydrogel using gamma irradiation for dye removal

    Science.gov (United States)

    Ghobashy, Mohamed Mohamady; Elhady, Mohamed., A.

    2017-05-01

    Emulsion polymerization is an efficient method for the production of new wax-hydrogel matrices of cetyl alcohol: stearic acid wax and acrylamide hydrogel using triethylamine (TEA) as an emulsifier. A cross-linking reaction occurred when a mixture of wax-hydrogel solution was irradiated with gamma rays at a dose of 20 kGy. The gelation percentage of the matrices (CtOH-StA/PAAm) was 86%, which indicates that a sufficiently high conversion occurred in these new wax-hydrogel matrices. The ability of PAAm and CtOH-StA/PAAm as an adsorbent for dye removal was investigated. The removal of three reactive dyes, namely Remazol Red (RR), Amido Black (AB), and Toluidine Blue (TB), from aqueous solutions depends on the pH of the dye solution. Removal efficiency was investigated by UV spectrophotometry, and the results showed the affinity of the wax hydrogel to adsorb TB was 98% after 320 min. Fourier transform infrared-attenuated total reflectance spectra confirmed the cross-linking process involved between the chains of wax and hydrogel; furthermore, scanning electron microscopy images showed that the wax and hydrogel were completely miscible to form a single matrix. Swelling measurements showed the high affinity of adsorbed dyes from aqueous solutions at different pH values to the wax-hydrogel network; the highest swelling values of 13.05 and 8.24 (g/g) were observed at pH 10 and 6, respectively

  13. Production of wax esters in plant seed oils by oleosomal cotargeting of biosynthetic enzymes[S

    Science.gov (United States)

    Heilmann, Mareike; Iven, Tim; Ahmann, Katharina; Hornung, Ellen; Stymne, Sten; Feussner, Ivo

    2012-01-01

    Wax esters are neutral lipids exhibiting desirable properties for lubrication. Natural sources have traditionally been whales. Additionally some plants produce wax esters in their seed oil. Currently there is no biological source available for long chain length monounsaturated wax esters that are most suited for industrial applications. This study aimed to identify enzymatic requirements enabling their production in oilseed plants. Wax esters are generated by the action of fatty acyl-CoA reductase (FAR), generating fatty alcohols and wax synthases (WS) that esterify fatty alcohols and acyl-CoAs to wax esters. Based on their substrate preference, a FAR and a WS from Mus musculus were selected for this study (MmFAR1 and MmWS). MmWS resides in the endoplasmic reticulum (ER), whereas MmFAR1 associates with peroxisomes. The elimination of a targeting signal and the fusion to an oil body protein yielded variants of MmFAR1 and MmWS that were cotargeted and enabled wax ester production when coexpressed in yeast or Arabidopsis. In the fae1 fad2 double mutant, rich in oleate, the cotargeted variants of MmFAR1 and MmWS enabled formation of wax esters containing >65% oleyl-oleate. The data suggest that cotargeting of unusual biosynthetic enzymes can result in functional interplay of heterologous partners in transgenic plants. PMID:22878160

  14. Simple Synthesis Hydrogenated Castor Oil Fatty Amide Wax and Its Coating Characterization.

    Science.gov (United States)

    Yu, Xiuzhu; Wang, Ning; Zhang, Rui; Zhao, Zhong

    2017-07-01

    A simple method for incorporating amine groups in hydrogenated castor oil (HCO) to produce wax for beeswax or carnauba wax substitution in packaging and coating was developed. From the conversion rate of the products, HCO was reacted with ethanolamine at 150°C for 5 h, and the molar ratio of HCO and ethanolamine was 1:4. The hardness of the final product was seven times higher than that of beeswax, the cohesiveness of the final product was 1.3 times higher than that of beeswax and approximately one half of that of carnauba wax, and the melting point of the final product is 98°C. The Fourier transform Infrared spectroscopy showed that the amide groups were incorporated to form the amide products. In coating application, the results showed that the force of the final product coating cardboard was higher than that of beeswax and paraffin wax and less than that of carnauba wax. After 24 h soaking, the compression forces were decreased. HCO fatty acid wax can be an alternative wax for carnauba wax and beeswax in coating applications.

  15. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery

    Science.gov (United States)

    Attard, Thomas M.; McElroy, Con Robert; Hunt, Andrew J.

    2015-01-01

    To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be €88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of €10.87 per kg of wax (based on 27% combustion efficiency for electricity generation) and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation). A sensitivity analysis study showed that utility costs (cost of electricity) had the greatest effect on the COM. PMID:26263976

  16. Organogels of vegetable oil with plant wax – trans/saturated fat replacements

    Science.gov (United States)

    This featured article reviews recent advances on the development of trans fat-free, low saturated fat food products from organogels formed by a plant wax in a vegetable oil. Plant waxes are of great interest in this research area because they are obtained as by-products during the oil refining proce...

  17. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery.

    Science.gov (United States)

    Attard, Thomas M; McElroy, Con Robert; Hunt, Andrew J

    2015-07-31

    To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be € 88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of € 10.87 per kg of wax (based on 27% combustion efficiency for electricity generation) and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation). A sensitivity analysis study showed that utility costs (cost of electricity) had the greatest effect on the COM.

  18. Investigations of Properties of Wax Mixtures Used in the Investment Casting Technology – New Investigation Methods

    Directory of Open Access Journals (Sweden)

    J. Zych

    2012-09-01

    Full Text Available The results of testing of the selected group of wax mixtures used in the investment casting technology, are presented in the paper. Themeasurements of the kinetics of the mixtures shrinkage and changes of viscous-plastic properties as a temperature function wereperformed. The temperature influence on bending strength of wax mixtures was determined.

  19. Discerning adaptive value of seasonal variation in preen waxes : comparative and experimental approaches

    NARCIS (Netherlands)

    Reneerkens, Jeroen; Piersma, Theunis; Sinninghe Damsté, Jaap S.

    2006-01-01

    Birds possess a preen (or uropygial) gland on their rump that secretes substances which are preened into the plumage, and which are probably essential for plumage maintenance. Secretions of the uropygial gland consist predominantly of wax-esters: fatty acids esterified to alcohols. These wax compone

  20. Trichloroacetate, an inhibitor of wax biosynthesis, prevents the development of hyperhydricity in Arabidopsis seedlings

    NARCIS (Netherlands)

    Klerk, de Geert Jan; Pramanik, Dewi

    2017-01-01

    Arabidopsis seedlings developed severe hyperhydricity (HH) when 0.2% Gelrite was used to solidify the medium instead of 0.7% agar. One mM trichloroacetate (TCA, an inhibitor of wax synthesis) strongly reduced the amount of wax. TCA also strongly increased the permeability of leaves for water as show

  1. Cuticular wax composition of Salix varieties in relation to biomass productivity.

    Science.gov (United States)

    Teece, Mark A; Zengeya, Thomas; Volk, Timothy A; Smart, Lawrence B

    2008-01-01

    The leaf cuticular waxes of six Salix clones (one Salix miyabeana, one Salix dasyclados, one Salix eriocephala, two Salix purpurea, and one interspecific hybrid of Salix eriocephala x interior) with different biomass productivities were characterized by gas chromatography-mass spectrometry. Total wax content ranged from 6.3 to 16.8 microg cm(-2), and two distinct patterns of wax were measured. The wax from leaves of S. dasyclados 'SV1' differed from all other clones and was dominated by fatty acids (42%), high concentrations of n-alkanes (25%) and n-alcohols (28%), with low n-aldehyde content (4%). All other clones produced cuticular wax dominated by n-alcohols (32-51%), particularly 1-hexacosanol, with fatty acids (14-37%) and n-aldehydes (19-26%) present in lower abundances. Clones of Salix grown under identical environmental conditions produce noticeably different amounts of cuticular wax. In contrast to previous studies of Salix, total wax content was independent of biomass productivity, measured as basal area, suggesting that wax production is not directly linked with woody biomass production by shrub willows under these site conditions.

  2. Fruit cuticular waxes as a source of biologically active triterpenoids.

    Science.gov (United States)

    Szakiel, Anna; Pączkowski, Cezary; Pensec, Flora; Bertsch, Christophe

    2012-06-01

    The health benefits associated with a diet rich in fruit and vegetables include reduction of the risk of chronic diseases such as cardiovascular disease, diabetes and cancer, that are becoming prevalent in the aging human population. Triterpenoids, polycyclic compounds derived from the linear hydrocarbon squalene, are widely distributed in edible and medicinal plants and are an integral part of the human diet. As an important group of phytochemicals that exert numerous biological effects and display various pharmacological activities, triterpenoids are being evaluated for use in new functional foods, drugs, cosmetics and healthcare products. Screening plant material in the search for triterpenoid-rich plant tissues has identified fruit peel and especially fruit cuticular waxes as promising and highly available sources. The chemical composition, abundance and biological activities of triterpenoids occurring in cuticular waxes of some economically important fruits, like apple, grape berry, olive, tomato and others, are described in this review. The need for environmentally valuable and potentially profitable technologies for the recovery, recycling and upgrading of residues from fruit processing is also discussed.

  3. Thermochemical investigation of molten fluoride salts for Generation IV nuclear applications - an equilibrium exercise

    NARCIS (Netherlands)

    Meer, J.P.M. van der

    2006-01-01

    The concept of the Molten Salt Reactor, one of the so-called Generation IV future reactors, is that the fuel, a fissile material, which is dissolved in a molten fluoride salt, circulates through a closed circuit. The heat of fission is transferred to a second molten salt coolant loop, the heat of wh

  4. Novel bone wax based on poly(ethylene glycol)-calcium phosphate cement mixtures.

    Science.gov (United States)

    Brückner, Theresa; Schamel, Martha; Kübler, Alexander C; Groll, Jürgen; Gbureck, Uwe

    2016-03-01

    Classic bone wax is associated with drawbacks such as the risk of infection, inflammation and hindered osteogenesis. Here, we developed a novel self-setting bone wax on the basis of hydrophilic poly(ethylene glycol) (PEG) and hydroxyapatite (HA) forming calcium phosphate cement (CPC), to overcome the problems that are linked to the use of conventional beeswax systems. Amounts of up to 10 wt.% of pregelatinized starch were additionally supplemented as hemostatic agent. After exposure to a humid environment, the PEG phase dissolved and was exchanged by penetrating water that interacted with the HA precursor (tetracalcium phosphate (TTCP)/monetite) to form highly porous, nanocrystalline HA via a dissolution/precipitation reaction. Simultaneously, pregelatinized starch could gel and supply the bone wax with liquid sealing features. The novel bone wax formulation was found to be cohesive, malleable and after hardening under aqueous conditions, it had a mechanical performance (∼2.5 MPa compressive strength) that is comparable to that of cancellous bone. It withstood systolic blood pressure conditions for several days and showed antibacterial properties for almost one week, even though 60% of the incorporated drug vancomycin hydrochloride was already released after 8h of deposition by diffusion controlled processes. The study investigated the development of alternative bone waxes on the basis of a hydroxyapatite (HA) forming calcium phosphate cement (CPC) system. Conventional bone waxes are composed of non-biodegradable beeswax/vaseline mixtures that are often linked to infection, inflammation and hindered osteogenesis. We combined the usage of bioresorbable polymers, the supplementation with hemostatic agents and the incorporation of a mineral component to overcome those drawbacks. Self-setting CPC precursors (tetracalcium phosphate (TTCP), monetite) were embedded in a resorbable matrix of poly(ethylene glycol) (PEG) and supplemented with pregelatinized starch. This

  5. System and method for the mitigation of paraffin wax deposition from crude oil by using ultrasonic waves

    Science.gov (United States)

    Towler, Brian F.

    2007-09-04

    A method for mitigating the deposition of wax on production tubing walls. The method comprises positioning at least one ultrasonic frequency generating device adjacent the production tubing walls and producing at least one ultrasonic frequency thereby disintegrating the wax and inhibiting the wax from attaching to the production tubing walls. A system for mitigating the deposition of wax on production tubing walls is also provided.

  6. Numerical performance study of paraffin wax dispersed with alumina in a concentric pipe latent heat storage system

    OpenAIRE

    Valan Arasu Amirtham; Sasmito Agus P.; Mujumdar Arun S.

    2013-01-01

    Latent heat energy storage systems using paraffin wax could have lower heat transfer rates during melting/freezing processes due to its inherent low thermal conductivity. The thermal conductivity of paraffin wax can be enhanced by employing high conductivity materials such as alumina (Al2O3). A numerical analysis has been carried out to study the performance enhancement of paraffin wax with nanoalumina (Al2O3) particles in comparison with simple paraffin wax in a concentric double pipe ...

  7. Composition and morphology of cuticular wax in blueberry (Vaccinium spp.) fruits.

    Science.gov (United States)

    Chu, Wenjing; Gao, Haiyan; Cao, Shifeng; Fang, Xiangjun; Chen, Hangjun; Xiao, Shangyue

    2017-03-15

    The chemical composition and morphology of cuticular wax in mature fruit of nine blueberry cultivars were investigated using gas chromatography-mass spectrometry (GC-MS) and scanning electron microscope (SEM). Triterpenoids and β-diketones were the most prominent compounds, accounting for on average 64.2% and 16.4% of the total wax, respectively. Ursolic or oleanolic acid was identified as the most abundant triterpenoids differing in cultivars. Two β-diketones, hentriacontan-10,12-dione and tritriacontan-12,14-dione, were detected in cuticular wax of blueberry fruits for the first time. Notably, hentriacontan-10,12-dione and tritriacontan-12,14-dione were only detected in highbush (V. corymbosum) and rabbiteye (V. ashei) blueberries, respectively. The results of SEM showed that a large amount of tubular wax deposited on the surface of blueberry fruits. There was no apparent difference in wax morphology among the nine cultivars. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Separation of different paraffin wax grades using two comparative deoiling techniques

    Energy Technology Data Exchange (ETDEWEB)

    Zaky, Magdy T.; Mohamed, Nermen H.; Farag, Amal S. [Petroleum Refining Division, Egyptian Petroleum Research Institute (EPRI), Nasr City, P. O. Box 11727, Cairo (Egypt)

    2007-09-15

    One stage fractional crystallization and solvent percolation techniques have been used to separate different grades of paraffin waxes; with different characteristics; from El-Ameria light, middle and heavy slack waxes. The two deoiling techniques were performed using ethyl acetate and butyl acetate solvents at ambient temperature of 20 C, at different dilution solvent ratios (S/F by weight) ranging from 2:1 to 8:1 and constant washing solvent ratio of 2:1 for the first technique and at different percolation solvent ratios ranging from 4:1 to 14:1 for the second one. The resulting data revealed that fractional crystallization technique is more suitable for deoiling the heavy slack wax using butyl acetate solvent than the percolation technique. While, percolation technology is a preferable technique using ethyl acetate or butyl acetate solvent for separation of paraffin waxes from light and middle slack waxes. (author)

  9. On the theory for the arrest of an advancing molten contact line on a cold solid of the same material

    Science.gov (United States)

    Schiaffino, Stefano; Sonin, Ain A.

    1997-08-01

    We show that a conventional continuum formulation of the equations and boundary conditions for the spreading of a pure molten material over a cold, solid substrate of its own kind has no meaningful solution for the angle of attack θs of the fusion front at the contact line, which is the quantity that determines contact-line arrest. θs is determined by the heat flux just behind the contact line, and the heat flux in the mathematical model is singular at the contact line. The scale of the physical mechanism which limits the heat flux at the contact line and removes the singularity is estimated by computing the point where the continuum model must be cut off in order to bring it into agreement with the experimental data for a microcrystalline wax. The cutoff scale is in the range 0.1-1 μm, that is, much larger than molecular dimensions, but of order 10-2-10-1 times the convective thermal length scale α/U.

  10. Scientific Opinion on the re-evaluation of microcrystalline wax (E 905 as a food additive

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS

    2013-04-01

    Full Text Available Following a request from the European Commission, the Panel on Food Additives and Nutrient Sources added to Food (ANS was asked to deliver a scientific opinion on microcrystalline wax (E 905 when used as a food additive. Microcrystalline wax (E 905 is authorised quantum satis as a surface treatment agent on non-chocolate confectionery, chewing gum and decorations, coatings and fillings, except fruit based fillings. It is also permitted as a surface treatment of melons, papaya, mango and avocado. The substance was evaluated by the Scientific Committee on Food (SCF in 1990 and 1995 and by the Joint FAO/WHO Expert Committee on Food Additives (JECFA, the latest in 1995. The JECFA established a group ADI of 20 mg/kg bw/day for mineral oils, paraffins and microcrystalline waxes. The Panel noted that all mineral oil products accumulated in tissues in a dose- and time-dependent manner with the exception of microcrystalline waxes. The Panel concluded that there is no concern for genotoxicity from microcrystalline wax (E 905. The Panel also considered that the available toxicity studies with mineral hydrocarbons, closely related from a chemical point of view with microcrystalline waxes, consistently reported no effects of concern associated with the intake of microcrystalline wax. The Panel further concluded that since no long-term toxicity and carcinogenicity studies with microcrystalline wax E 905 were available, no ADI could be established. The Panel also concluded that the conservative exposure estimates to microcrystalline wax (E 905 from its use at maximum permitted level (following quantum satis rules, resulted in a sufficient margin of safety compared to the NOAEL established by the Panel for the closely related high viscosity mineral oils, and therefore the use microcrystalline wax (E 905 as a food additive with the currently authorised uses would not be of safety concern.

  11. Quantitative Evaluation of Tissue Surface Adaption of CAD-Designed and 3D Printed Wax Pattern of Maxillary Complete Denture

    Directory of Open Access Journals (Sweden)

    Hu Chen

    2015-01-01

    Full Text Available Objective. To quantitatively evaluate the tissue surface adaption of a maxillary complete denture wax pattern produced by CAD and 3DP. Methods. A standard edentulous maxilla plaster cast model was used, for which a wax pattern of complete denture was designed using CAD software developed in our previous study and printed using a 3D wax printer, while another wax pattern was manufactured by the traditional manual method. The cast model and the two wax patterns were scanned in the 3D scanner as “DataModel,” “DataWaxRP,” and “DataWaxManual.” After setting each wax pattern on the plaster cast, the whole model was scanned for registration. After registration, the deviations of tissue surface between “DataModel” and “DataWaxRP” and between “DataModel” and “DataWaxManual” were measured. The data was analyzed by paired t-test. Results. For both wax patterns produced by the CAD&RP method and the manual method, scanning data of tissue surface and cast surface showed a good fit in the majority. No statistically significant (P>0.05 difference was observed between the CAD&RP method and the manual method. Conclusions. Wax pattern of maxillary complete denture produced by the CAD&3DP method is comparable with traditional manual method in the adaption to the edentulous cast model.

  12. 76 FR 46277 - Petroleum Wax Candles From the People's Republic of China: Final Results of Request for Comments...

    Science.gov (United States)

    2011-08-02

    ... International Trade Administration Petroleum Wax Candles From the People's Republic of China: Final Results of... request for comments on the scope of antidumping duty order on petroleum wax candles from the People's... determinations involving the Order. \\1\\ See Petroleum Wax Candles from the People's Republic of China...

  13. Structural change in molten basalt at deep mantle conditions.

    Science.gov (United States)

    Sanloup, Chrystèle; Drewitt, James W E; Konôpková, Zuzana; Dalladay-Simpson, Philip; Morton, Donna M; Rai, Nachiketa; van Westrenen, Wim; Morgenroth, Wolfgang

    2013-11-07

    Silicate liquids play a key part at all stages of deep Earth evolution, ranging from core and crust formation billions of years ago to present-day volcanic activity. Quantitative models of these processes require knowledge of the structural changes and compression mechanisms that take place in liquid silicates at the high pressures and temperatures in the Earth's interior. However, obtaining such knowledge has long been impeded by the challenging nature of the experiments. In recent years, structural and density information for silica glass was obtained at record pressures of up to 100 GPa (ref. 1), a major step towards obtaining data on the molten state. Here we report the structure of molten basalt up to 60 GPa by means of in situ X-ray diffraction. The coordination of silicon increases from four under ambient conditions to six at 35 GPa, similar to what has been reported in silica glass. The compressibility of the melt after the completion of the coordination change is lower than at lower pressure, implying that only a high-order equation of state can accurately describe the density evolution of silicate melts over the pressure range of the whole mantle. The transition pressure coincides with a marked change in the pressure-evolution of nickel partitioning between molten iron and molten silicates, indicating that melt compressibility controls siderophile-element partitioning.

  14. Sorbitol dehydration into isosorbide in a molten salt hydrate medium

    NARCIS (Netherlands)

    Li, J.; Spina, A.; Moulijn, J.A.; Makkee, M.

    2013-01-01

    The sorbitol conversion in a molten salt hydrate medium (ZnCl2; 70 wt% in water) was studied. Dehydration is the main reaction, initially 1,4- and 3,6-anhydrosorbitol are the main products that are subsequently converted into isosorbide; two other anhydrohexitols, (1,5- and 2,5-), formed are in less

  15. Treatment of plutonium process residues by molten salt oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Stimmel, J.; Wishau, R.; Ramsey, K.B.; Montoya, A.; Brock, J. [Los Alamos National Lab., NM (United States); Heslop, M. [Naval Surface Warfare Center (United States). Indian Head Div.; Wernly, K. [Molten Salt Oxidation Corp. (United States)

    1999-04-01

    Molten Salt Oxidation (MSO) is a thermal process that can remove more than 99.999% of the organic matrix from combustible {sup 238}Pu material. Plutonium processing residues are injected into a molten salt bed with an excess of air. The salt (sodium carbonate) functions as a catalyst for the conversion of the organic material to carbon dioxide and water. Reactive species such as fluorine, chlorine, bromine, iodine, sulfur, phosphorous and arsenic in the organic waste react with the molten salt to form the corresponding neutralized salts, NaF, NaCl, NaBr, NaI, Na{sub 2}SO{sub 4}, Na{sub 3}PO{sub 4} and NaAsO{sub 2} or Na{sub 3}AsO4. Plutonium and other metals react with the molten salt and air to form metal salts or oxides. Saturated salt will be recycled and aqueous chemical separation will be used to recover the {sup 238}Pu. The Los Alamos National Laboratory system, which is currently in the conceptual design stage, will be scaled down from current systems for use inside a glovebox.

  16. Release properties of UC sub x and molten U targets

    CERN Document Server

    Roussière, B; Sauvage, J; Bajeat, O; Barre, N; Clapier, F; Cottereau, E; Donzaud, C; Ducourtieux, M; Essabaa, S; Guillemaud-Müller, D; Lau, C; Lefort, H; Liang, C F; Le Blanc, F; Müller, A C; Obert, J; Pauwels, N; Potier, J C; Pougheon, F; Proust, J; Sorlin, O; Verney, D; Wojtasiewicz, A

    2002-01-01

    The release properties of UC sub x and molten U thick targets associated with a Nier-Bernas ion source have been studied. Two experimental methods are used to extract the release time. Results are presented and discussed for Kr, Cd, I and Xe.

  17. Thermodynamic characterization of salt components for Molten Salt Reactor fuel

    NARCIS (Netherlands)

    Capelli, E.

    2016-01-01

    The Molten Salt Reactor (MSR) is a promising future nuclear fission reactor technology with excellent performance in terms of safety and reliability, sustainability, proliferation resistance and economics. For the design and safety assessment of this concept, it is extremely important to have a thor

  18. Two techniques enable sampling of filtered and unfiltered molten metals

    Science.gov (United States)

    Burris, L., Jr.; Pierce, R. D.; Tobias, K. R.; Winsch, I. O.

    1967-01-01

    Filtered samples of molten metals are obtained by filtering through a plug of porous material fitted in the end of a sample tube, and unfiltered samples are obtained by using a capillary-tube extension rod with a perforated bucket. With these methods there are no sampling errors or loss of liquid.

  19. Research and development issues for molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Krumpelt, M.

    1996-04-01

    This paper describes issues pertaining to the development of molten carbonate fuel cells. In particular, the corrosion resistance and service life of nickel oxide cathodes is described. The resistivity of lithium oxide/iron oxides and improvement with doping is addressed.

  20. Oxygen electrode reaction in molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Appleby, A.J.; White, R.E.

    1992-07-07

    Molten carbonate fuel cell system is a leading candidate for the utility power generation because of its high efficiency for fuel to AC power conversion, capability for an internal reforming, and a very low environmental impact. However, the performance of the molten carbonate fuel cell is limited by the oxygen reduction reaction and the cell life time is limited by the stability of the cathode material. An elucidation of oxygen reduction reaction in molten alkali carbonate is essential because overpotential losses in the molten carbonate fuel cell are considerably greater at the oxygen cathode than at the fuel anode. Oxygen reduction on a fully-immersed gold electrode in a lithium carbonate melt was investigated by electrochemical impedance spectroscopy and cyclic voltammetry to determine electrode kinetic and mass transfer parameters. The dependences of electrode kinetic and mass transfer parameters on gas composition and temperature were examined to determine the reaction orders and the activation energies. The results showed that oxygen reduction in a pure lithium carbonate melt occurs via the peroxide mechanism. A mass transfer parameter, D{sub O}{sup 1/2}C{sub O}, estimated by the cyclic voltammetry concurred with that calculated by the EIS technique. The temperature dependence of the exchange current density and the product D{sub O}{sup 1/2}C{sub O} were examined and the apparent activation energies were determined to be about 122 and 175 kJ/ mol, respectively.

  1. Release properties of UC$_x$ and molten U targets

    CERN Document Server

    Roussière, B; Sauvage, J; Bajeat, O; Barre, N; Clapier, F; Cottereau, E; Donzaud, C; Ducourtieux, M; Essabaa, S; Guillemaud-Müller, D; Lau, C; Lefort, H; Liang, C F; Le Blanc, F; Müller, A C; Obert, J; Pauwels, N; Potier, J C; Pougheon, F; Proust, J; Sorlin, O; Verney, D; Wojtasiewicz, A

    2002-01-01

    The release properties of UC$_x$ and molten U thick targets associated with a Nier- Bernas ion source have been studied. Two experimental methods are used to extract the release time. Results are presented and discussed for Kr, Cd, I and Xe.

  2. Study on electrochemical characteristics of steel in molten sodium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Aoto, Kazumi [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

    2003-06-01

    Electrochemical characteristics of steel corrosion in molten sodium oxides were studied. No report exists about such electrochemical experiments in the melt because this molten salt is very corrosive and sodium easily corrodes gold used as a reference electrode by forming eutectics. In this study, proper protection using zirconia for the equipment part exposed to the corrosive atmosphere and the acceleration of scanning rate of the electric potential led to realization of the measurement of corrosion potential and polarization curves of steel in molten sodium oxides. Electrochemical characteristics measured agreed with the features of two types of corrosion derived from previous works such as the immersed corrosion test. Those are consistent with the fact that 'Molten salt type corrosion' occurs in the melt with higher oxygen potential and 'Na-Fe double oxidation type corrosion' occurs in the basic melt. The estimated corrosion rate for the corrosion based on the corrosion current density almost agrees with the prediction by each proposed equation. (author)

  3. Nickel catalysts for internal reforming in molten carbonate fuel cells

    NARCIS (Netherlands)

    Berger, R.J.; Doesburg, E.B.M.; Ommen, van J.G.; Ross, J.R.H.

    1996-01-01

    Natural gas may be used instead of hydrogen as fuel for the molten carbonate fuel cell (MCFC) by steam reforming the natural gas inside the MCFC, using a nickel catalyst (internal reforming). The severe conditions inside the MCFC, however, require that the catalyst has a very high stability. In orde

  4. Electrochemical Deposition of Uranium Metal in Molten Salt

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Based on the studies in the electrode process of uranium ions in the molten LiCl-KCl, we carried out the electrochemical deposition of uranium in two kinds of melts, LiCl-KCl-UCl3 and LiCl- KCl-UCl3-

  5. Molten-Salt-Based Growth of Group III Nitrides

    Science.gov (United States)

    Waldrip, Karen E.; Tsao, Jeffrey Y.; Kerley, Thomas M.

    2008-10-14

    A method for growing Group III nitride materials using a molten halide salt as a solvent to solubilize the Group-III ions and nitride ions that react to form the Group III nitride material. The concentration of at least one of the nitride ion or Group III cation is determined by electrochemical generation of the ions.

  6. Alloys compatibility in molten salt fluorides: Kurchatov Institute related experience

    Energy Technology Data Exchange (ETDEWEB)

    Ignatiev, Victor, E-mail: ignatiev@vver.kiae.ru; Surenkov, Alexandr

    2013-10-15

    In the last several years, there has been an increased interest in the use of high-temperature molten salt fluorides in nuclear power systems. For all molten salt reactor designs, materials selection is a very important issue. This paper summarizes results, which led to selection of materials for molten salt reactors in Russia. Operating experience with corrosion thermal convection loops has demonstrated good capability of the “nickel–molybdenum alloys + fluoride salt fueled by UF{sub 4} and PuF{sub 3} + cover gas” system up to 750 °C. A brief description is given of the container material work in progress. Tellurium corrosion of Ni-based alloys in stressed and unloaded conditions studies was also tested in different molten salt mixtures at temperatures up to 700–750 °C, also with measurement of the redox potential. HN80MTY alloy with 1% added Al is the most resistant to tellurium intergranular cracking of Ni-base alloys under study.

  7. Corrosion Behavior of Alloys in Molten Fluoride Salts

    Science.gov (United States)

    Zheng, Guiqiu

    The molten fluoride salt-cooled high-temperature nuclear reactor (FHR) has been proposed as a candidate Generation IV nuclear reactor. This reactor combines the latest nuclear technology with the use of molten fluoride salt as coolant to significantly enhance safety and efficiency. However, an important challenge in FHR development is the corrosion of structural materials in high-temperature molten fluoride salt. The structural alloys' degradation, particularly in terms of chromium depletion, and the molten salt chemistry are key factors that impact the lifetime of nuclear reactors and the development of future FHR designs. In support of materials development for the FHR, the nickel base alloy of Hastelloy N and iron-chromium base alloy 316 stainless steel are being actively considered as critical structural alloys. Enriched 27LiF-BeF2 (named as FLiBe) is a promising coolant for the FHR because of its neutronic properties and heat transfer characteristics while operating at atmospheric pressure. In this study, the corrosion behavior of Ni-5Cr and Ni-20Cr binary model alloys, and Hastelloy N and 316 stainless steel in molten FLiBe with and without graphite were investigated through various microstructural analyses. Based on the understanding of the corrosion behavior and data of above four alloys in molten FLiBe, a long-term corrosion prediction model has been developed that is applicable specifically for these four materials in FLiBe at 700ºC. The model uses Cr concentration profile C(x, t) as a function of corrosion distance in the materials and duration fundamentally derived from the Fick's diffusion laws. This model was validated with reasonable accuracy for the four alloys by fitting the calculated profiles with experimental data and can be applied to evaluate corrosion attack depth over the long-term. The critical constant of the overall diffusion coefficient (Deff) in this model can be quickly calculated from the experimental measurement of alloys' weight

  8. Preliminary safety calculations to improve the design of Molten Salt Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Brovchenko, M.; Heuer, D.; Merle-Lucotte, E.; Allibert, M.; Capellan, N.; Ghetta, V.; Laureau, A. [LPSC, CNRS/IN2P3, Grenoble INP, 53,rue des Martyrs, 38026 Grenoble Cedex (France)

    2012-07-01

    Molten salt reactors are liquid fuel reactors so that they are flexible in operation but very different in the safety approach from solid fuel reactors. This study bears on the specific concept named Molten Salt Fast Reactor (MSFR). Since this new nuclear technology is in development, safety is an essential point to be considered all along the R and D studies. This paper presents the first step of the safety approach: the systematic description of the MSFR, limited here to the main systems surrounding the core. This systematic description is the basis on which we will be able to devise accidental scenarios. Thanks to the negative reactivity feedback coefficient, most accidental scenarios lead to reactor shut down. Because of the decay heat generated in the fuel salt, it must be cooled. After the description of the tools developed to calculate the residual heat, the different contributions are discussed in this study. The decay heat of fission products in the MSFR is evaluated to be low (3% of nominal power), mainly due to the reprocessing that transfers the fission products to the gas reprocessing unit. As a result, the contribution of the actinides is significant (0.5% of nominal power). The unprotected loss of heat sink transients are studied in this paper. It appears that slow transients are favorable (> 1 min) to minimize the temperature increase of the fuel salt. This work will be the basis of further safety studies as well as an essential parameter for the design of the draining system. (authors)

  9. Development status and potential program for development of proliferation-resistant molten-salt reactors

    Energy Technology Data Exchange (ETDEWEB)

    Engel, J.R.; Bauman, H.F.; Dearing, J.F.; Grimes, W.R.; McCoy, H.E. Jr.

    1979-03-01

    Preliminary studies of existing and conceptual molten-salt reactor (MSR) designs have led to the identification of conceptual systems that are technologically attractive when operated with denatured uranium as the principal fissile fuel. These denatured MSRs would also have favorable resource-utilization characteristics and substantial resistance to proliferation of weapons-usable nuclear materials. The report presents a summary of the current status of technology and a discussion of the major technical areas of a possible base program to develop commercial denatured MSRs. The general areas treated are (1) reactor design and development, (2) safety and safety related technology, (3) fuel-coolant behavior and fuel processing, and (4) reactor materials. A substantial development effort could lead to authorization for construction of a molten-salt test reactor about 5 years after the start of the program and operation of the unit about 10 years later. A prototype commercial denatured MSR could be expected to begin operating 25 years from the start of the program. The postulated base program would extend over 32 years and would cost about $700 million (1978 dollars, unescalated). Additional costs to construct the MSTR, $600 million, and the prototype commercial plant, $1470 million, would bring the total program cost to about $2.8 billion. Additional allowances probably should be made to cover contingencies and incidental technology areas not explicitly treated in this preliminary review.

  10. Paraffin wax as a diluent for extraction and separation of trivalent gallium, indium, and thallium with 2,6-bis-(1′-phenyl-3′-methyl-5′- oxopyrazole-4′) pyridineacyl

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A method is proposed for the extraction and separation of trivalent gallium, indium and thallium from their corre-sponding aqueous solutions at 65°C with 2, 6-bis-(l'-phenyl-3'-methyl-5'-oxopyrazole-4') pyridineacyl (H2PMBPPor H2A)using molten paraffin wax as a diluent. The values of pH 1/2 for extraction of gallium, indium and thallium are 2.62, 4.32 and4.93, respectively. Gallium can be extracted by H2PMBPP at a lower acid medium. The effect of solvent and the composi-tion of the extracted species are reported. And the thermodynamic data of the extraction are also obtained.

  11. Oxidized Polyethylene Wax as a Potential Carbon Source for PHA Production

    Directory of Open Access Journals (Sweden)

    Iza Radecka

    2016-05-01

    Full Text Available We report on the ability of bacteria to produce biodegradable polyhydroxyalkanoates (PHA using oxidized polyethylene wax (O-PEW as a novel carbon source. The O-PEW was obtained in a process that used air or oxygen as an oxidizing agent. R. eutropha H16 was grown for 48 h in either tryptone soya broth (TSB or basal salts medium (BSM supplemented with O-PEW and monitored by viable counting. Study revealed that biomass and PHA production was higher in TSB supplemented with O-PEW compared with TSB only. The biopolymers obtained were preliminary characterized by nuclear magnetic resonance (NMR, gel permeation chromatography (GPC, differential scanning calorimetry (DSC, and thermogravimetric analysis (TGA. The detailed structural evaluation at the molecular level was performed by electrospray ionization tandem mass spectrometry (ESI-MS/MS. The study revealed that, when TSB was supplemented with O-PEW, bacteria produced PHA which contained 3-hydroxybutyrate and up to 3 mol % of 3-hydroxyvalerate and 3-hydroxyhexanoate co-monomeric units. The ESI-MS/MS enabled the PHA characterization when the content of 3-hydroxybutyrate was high and the appearance of other PHA repeating units was very low.

  12. Fundamental study of molten pool depth measurement method using an ultrasonic phased array system

    Science.gov (United States)

    Mizota, Hirohisa; Nagashima, Yoshiaki; Obana, Takeshi

    2015-07-01

    The molten pool depth measurement method using an ultrasonic phased array system has been developed. The molten pool depth distribution is evaluated by comparing the times taken by the ultrasonic wave to propagate through a molten pool and a solid-phase and through only the solid-phase near the molten pool. Maximum molten pool depths on a flat type-304 stainless-steel plate, formed with a gas tungsten arc welding machine for different welding currents from 70 to 150 A, were derived within an error of ±0.5 mm.

  13. Molar Volume Analysis of Molten Ni-Al-Co Alloy by Measuring the Density

    Institute of Scientific and Technical Information of China (English)

    XIAO Feng; FANG Liang; FU Yuechao; YANG Lingchuan

    2004-01-01

    The density of molten Ni-Al-Co alloys was measured in the temperature range of 1714~1873K using a modified pycnometric method, and the molar volume of molten alloys was analyzed. The density of molten Ni-Al-Co alloys was found to decrease with increasing temperature and Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys increases with increasing Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys shows a negative deviation from the linear molar volume.

  14. Physical behavior of purified and crude wax obtained from sunflower (Helianthus annuus) seed oil refineries and seed hulls.

    Science.gov (United States)

    Kanya, T C Sindhu; Sankar, K Udaya; Sastry, M C Shamnathaka

    2003-01-01

    The sunflower seed waxes obtained from two sources (i) seed hull as a standard and (ii) crude wax from oil refineries were studied for their crystallization, melting characteristics and morphology of crystals. The results of differential scanning calorimetry of wax obtained from seed hulls showed the melting temperature range of 13.18 degrees C with the onset at 62.32 degrees C, for purified wax, compared to the melting range of 24.73 degrees C with the onset at 42.3 degrees C. for crude wax. The enthalpy of fusion for both waxes were 57.55 mcal/mg and 7.63 mcal/mg, respectively. The DSC melt crystallization temperature range was 15.79 degrees C with the onset of 64.58 degrees C for purified wax and temperature range of 31.45 degrees C with an onset of 57.76 degrees C for crude wax. A similar pattern was observed of wax obtained from the crude wax of oil refineries. The enthalpy of crystallization was -64.27 mcal/mg and -7.67 mcal/mg, respectively. The purified wax obtained from the two sources (i) and (ii) were comparable with completion temperatures of 75.5 degrees C and 75.1 degrees C, respectively. The effect of inhibitor (lecithin) on crystallization of purified wax under light microscope and surface structure by scanning electron microscope were observed. Lecithin at 0.2% inhibited the crystallization but nucleation was unaltered. The wax crystal was inhibited to around 60% of the original size with 0.2% lecithin. It is concluded that the sunflower waxes studied were not comparable in their crystal properties of crude and purified states. Lecithin inhibited the crystallization of sunflower seed wax.

  15. Magnetic properties of MnFe{sub 2}O{sub 4} nano-aggregates dispersed in paraffin wax

    Energy Technology Data Exchange (ETDEWEB)

    Aslibeiki, B., E-mail: b.aslibeiki@tabrizu.ac.ir [Department of Solid State Physics, Faculty of Physics, University of Tabriz, Tabriz 51666-16471 (Iran, Islamic Republic of); Kameli, P. [Department of Physics, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2015-07-01

    Manganese ferrite, MnFe{sub 2}O{sub 4} nanoparticles with average size of ∼6.5 nm were synthesized by using a thermal decomposition method. The nanoparticles were aggregated which was confirmed by FESEM and TEM images. The aggregates with a diameter of ∼50 nm showed interacting superspin glass (SSG) behavior. The powders were dispersed in the molten paraffin wax by using ultrasonic bath. Samples with different paraffin/ferrite weight ratios of P/F= 0, 1, 5, 10 and 20 were prepared. M–H curves of the samples revealed presence of superparamagnetic state at 300 K. Saturation magnetization (M{sub s}) decreased from 26.6 to 1.3 emu/g by increasing the P/F value from 0 to 20, respectively. Furthermore, the VSM measurements showed a decrease in surface spin disorder of paraffin-embedded nanoparticles in comparison with bare particles. The AC magnetic susceptibility peak temperature, T{sub P} increased from 230 to >300 K with increasing the paraffin content in the samples. The present study showed that by dispersing the particles in a non-magnetic matrix, the blocking temperature could be increased. - Highlights: ●MnFe{sub 2}O{sub 4}/paraffin nano-sized samples with different paraffin/ferrite ratios were prepared. ●The samples were superparamagnetic at room temperature. ●Bonding between paraffin molecules and surface atoms of ferrite particles reduced the surface spin disorder of nanoparticles. ●The blocking temperature increased with increasing the paraffin concentration is the samples.

  16. Transport barriers made of cutin, suberin and associated waxes.

    Science.gov (United States)

    Schreiber, Lukas

    2010-10-01

    Cutinized leaf epidermal cells and suberized root cell walls form important lipophilic interfaces between the plant and its environment, significantly contributing to the regulation of water uptake and the transport of solutes in and out of the plant. A wealth of new molecular information on the genes and enzymes contributing to cutin, suberin and wax biosynthesis have become available within the past few years, which is examined in the context of the functional properties of these barriers in terms of transport and permeability. Recent progress made in measuring transport properties of cutinized and suberized barriers in plants is reviewed, and promising approaches obtained with Arabidopsis and potato that might link the molecular information with transport properties are suggested.

  17. Removal of wax and stickies from OCC by flotation. Progress report No. 2, April 1--June 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Doshi, M.R.; Dyer, J. [Doshi and Associates, Inc., Appleton, WI (United States); Heise, O. [Voith Sulzer Papertechnology, Appleton, WI (United States)

    1998-08-01

    During the second quarter of the study the authors examined the conditions necessary for repulping a mixture of wax-coated boards that would be conducive to the flotation of detached wax. Also important for the economic viability of a waxed-board repulping process is adequate defibering of the recovered paper. Several methods for the dewaxing of pulped waxed-boards were investigated. The authors have continued to survey the literature to determine what other efforts are being made to ameliorate the impact of waxed boards during the recycling of OCC.

  18. Development and evaluation of modified release wax matrix tablet dosage form for tramadol hydrochloride

    Directory of Open Access Journals (Sweden)

    Paresh Ramesh Mahaparale

    2015-01-01

    Full Text Available The objective of this study was to develop modified release dosage forms of tramadol hydrochloride using wax matrix system by melt granulation method. The effect of various waxes, concentration of waxes, effect of excipients on the release profile of drug from wax matrix system was studied. Release retardant effect was observed in the order of hydrogenated vegetable oil (HVO > compritol >precirol. This may be due to more lipophilicity imparted by HVO than any other waxy substances. It was also observed that as ratio of drug: Wax was increased, it sustained release of drug for more time. This may be due to proper embedment/entrapment of drug in sufficient wax matrix system. In case of excipients, release retardant effect was found in order of dicalcium phosphate (DCP > microcrystalline cellulose (MCC > lactose. DCP is insoluble which helps in release retardation of drug. MCC is hydrophilic swellable polymer which showed release of drug by swelling. Lactose is soluble excipient which get dissolved and formed channels for entry of dissolution medium and release of drug occurred by erosion mechanism. Wax matrix tablets were found to be stable.

  19. Development of formulations and processes to incorporate wax oleogels in ice cream.

    Science.gov (United States)

    Zulim Botega, Daniele C; Marangoni, Alejandro G; Smith, Alexandra K; Goff, H Douglas

    2013-12-01

    The objective of this study was to investigate the influence of emulsifiers, waxes, fat concentration, and processing conditions on the application of wax oleogel to replace solid fat content and create optimal fat structure in ice cream. Ice creams with 10% or 15% fat were formulated with rice bran wax (RBW), candelilla wax (CDW), or carnauba wax (CBW) oleogels, containing 10% wax and 90% high-oleic sunflower oil. The ice creams were produced using batch or continuous freezing processes. Transmission electron microscopy (TEM) and cryo-scanning electron microscopy were used to evaluate the microstructure of ice cream and the ultrastructure of oleogel droplets in ice cream mixes. Among the wax oleogels, RBW oleogel had the ability to form and sustain structure in 15% fat ice creams when glycerol monooleate (GMO) was used as the emulsifier. TEM images revealed that the high degree of fat structuring observed in GMO samples was associated with the RBW crystal morphology within the fat droplet, which was characterized by the growth of crystals at the outer edge of the droplet. Continuous freezing improved fat structuring compared to batch freezing. RBW oleogels established better structure compared to CDW or CBW oleogels. These results demonstrate that RBW oleogel has the potential to develop fat structure in ice cream in the presence of GMO and sufficiently high concentrations of oleogel.

  20. SEPARATION OF FISCHER-TROPSCH WAX FROM CATALYST BY SUPERCRITICAL EXTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    MARK C. THIES; PATRICK C. JOYCE

    1998-10-31

    The objective of this research project is to evaluate the potential of supercritical fluid (SCF) extraction for the recovery and fractionation of the wax product from the slurry bubble column (SBC) reactor of the Fischer-Tropsch (F-T) process. The wax, comprised mostly of branched and linear alkanes with a broad molecular weight distribution up to C{sub 100}, will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300 C. Initial work is being performed using n-hexane as the solvent. The success of the project depends on two factors. First, the supercritical solvent must be able to dissolve the F-T wax; furthermore, this must be accomplished at conditions that do not entrain the solid catalyst. Second, the extraction must be controlled so as not to favor the removal of the low molecular weight wax compounds. That is, a constant carbon-number distribution in the wax slurry must be maintained at steady-state column operation. Three major tasks are being undertaken to evaluate our proposed SCF extraction process. Task 1: Equilibrium solubility measurements for model F-T wax components in supercritical fluids at conditions representative of those in a SBC reactor. Task 2: Thermodynamic modeling of the measured VLE data for extending our results to real wax systems. Task 3: Process design studies of our proposed process. Additional details of the task structure are given.

  1. The analysis of the possibility of the application of the casting waxes in the process RP

    Directory of Open Access Journals (Sweden)

    G. Budzik

    2009-04-01

    Full Text Available The article presents analysis of possibility of application of casting waxes in process of rapid prototyping of casting models in silicone the matrices. The researches were made on casting waxes applied to the manufacturing of precise casting models and also the model system. Testing waxes are intended nominally to the processing in process of the injection. The determining of possibility processing of waxes in silicone forms was purpose of researches. Researches concerned of whole manufacturing process i.e. the preparation of the form and wax, the filling of form and also the deforming. As a result of made researches the temperature of filling of matrix was determined. The main part of research process concerned determining of temperature of deforming for every with kinds of waxes. This is especially important in case of manufacturing of casting models of precise elements, which can be destroyed easily. In this purpose researches of the bending of waxen forms were made in the range of temperature 20-37ºC. The processing parameters of casting waxes were determined as a result of made researches.

  2. Anatomical models and wax Venuses: art masterpieces or scientific craft works?

    Science.gov (United States)

    Ballestriero, R

    2010-02-01

    The art of wax modelling has an ancient origin but rose to prominence in 14th century Italy with the cult of votive artefacts. With the advent of Neoclassicism this art, now deemed repulsive, continued to survive in a scientific environment, where it flourished in the study of normal and pathological anatomy, obstetrics, zoology and botany. The achievement of having originated the creation of anatomical models in coloured wax must be ascribed to a joint effort undertaken by the Sicilian wax modeller Gaetano Giulio Zumbo and the French surgeon Guillaume Desnoues in the late 17th century. Interest in anatomical wax models spread throughout Europe during the 18th century, first in Bologna with Ercole Lelli, Giovanni Manzolini and Anna Morandi, and then in Florence with Felice Fontana and Clemente Susini. In England, the art of anatomical ceroplastics was brought to London from Florence by the sculptor Joseph Towne. Throughout the centuries many anatomical artists preferred this material due to the remarkable mimetic likeness obtained, far surpassing any other material. Independent of the material used, whether wood, wax or clay, anatomical models were always considered merely craft works confined to hospitals or faculties of medicine and have survived to this day only because of their scientific interest. Italian and English waxes are stylistically different but the remarkable results obtained by Susini and Towne, and the fact that some contemporary artists are again representing anatomical wax bodies in their works, makes the border that formerly separated art and craft indistinguishable.

  3. Micromorphology of epicuticular wax structures of the garden strawberry leaves by electron microscopy: syntopism and polymorphism.

    Science.gov (United States)

    Kim, Ki Woo; Ahn, Jeong Joon; Lee, Joon-Ho

    2009-04-01

    Ultrastructural aspects of leaf epicuticular wax structures were investigated in the garden strawberry Fragariaxananassa by scanning and transmission electron microscopy. Both the adaxial and abaxial surfaces of two cultivars (Maehyang and Red Pearl) were collected and subjected to surface observations and ultrathin sections. The most prominent leaf epicuticular wax structures included membraneous platelets and angular rodlets. Most wax platelets were membraneous, and appeared to protrude from the surface at an acute angle. Angular rodlets were usually bent and had rather distinct facets in the abaxial surface of the two cultivars. Membraneous platelets were predominant on the adaxial surface of Maehyang, whereas the adaxial surface of Red Pearl was characterized by angular rodlets. However, both cultivars possessed angular rodlets on the abaxial surface, simultaneously. The combination of air-drying without vacuum and in-lens imaging of secondary electron signals with a field emission gun could impart the superb resolution at low electron dose with minimal specimen shrinkage. In vertical profiles of the leaf epidermis, epicuticular waxes were observed above the cuticle layer, and measured approximately as 50nm in thickness. The natural epicuticular waxes were seemingly mixtures of electron-dense microfibrils, and heterogeneous in shape on ultrathin sections. Distinct crystal-like strata could be hardly discernable in the wax structures. These results suggest that the garden strawberry has the nature of syntopism within one plant and polymorphism within the same species in the formation and occurrence of leaf epicuticular waxes.

  4. Thermal behavior of gamma-irradiated low-density polyethylene/paraffin wax blend

    Science.gov (United States)

    Abdou, Saleh M.; Elnahas, H. H.; El-Zahed, H.; Abdeldaym, A.

    2016-05-01

    The thermal properties of low-density polyethylene (LDPE)/paraffin wax blends were studied using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and melt flow index (MFI). Blends of LDPE/wax in ratios of 100/0, 98/2, 96/4, 94/6, 92/8, 90/10 and 85/15 (w/w) were prepared by melt-mixing at the temperature of 150°C. It was found that increasing the wax content more than 15% leads to phase separation. DSC results showed that for all blends both the melting temperature (Tm) and the melting enthalpy (ΔHm) decrease linearly with an increase in wax content. TGA analysis showed that the thermal stability of all blends decreases linearly with increasing wax content. No clear correlation was observed between the melting point and thermal stability. Horowitz and Metzger method was used to determine the thermal activation energy (Ea). MFI increased exponentially by increasing the wax content. The effect of gamma irradiation on the thermal behavior of the blends was also investigated at different gamma irradiation doses. Significant correlations were found between the thermal parameters (Tm, ΔHm, T5%, Ea and MFI) and the amount of wax content and gamma irradiation.

  5. Structural profiling of wax biopolymer from Pinus roxburghii Sarg. needles using spectroscopic methods.

    Science.gov (United States)

    Dubey, Pallavi; Sharma, Pradeep; Kumar, Vineet

    2017-11-01

    Pinus roxburghii Sarg. is the most abundant species in Himalayan region. The needles of the species largely contribute to the forest biomass and remain the major cause of forest fires leading to climate change, biodiversity loss, etc. Intriguingly, the layer of needles contains wax, a biomacromolecule with potential chemical functionalities for value addition. In the present study, a distinctive approach towards complete structural analysis of the isolated wax in its native state has been done using (1)H, (13)C, HSQC, HMBC, COSY, TOCSY along with GC-MS of the methyl esters of constituent fatty acids. The wax was isolated in a quantitative yield of 1.64% and analyses suggest that it is a polymer of linearly attached fatty acid esters which on hydrolysis yielded three types of ω-hydroxy fatty acids viz. 12-hydroxydodecanoic acid, 14-hydroxytetradecanoic acid and 16-hydroxyhexadecanoic acid in a ratio of 1:1:2 respectively. Complete assignments for a carbonyl group, α-, β- and other methylenes present in wax were achieved; corroborating the presence of polyester. In particular, identification of wax structure was accomplished through NMR; thereby providing a lead towards future structural analysis of waxes in their native form. The study would also be helpful to generate commercially important compounds derived from pine needle wax. This will offer an opportunity for utilisation of pine needle biomass: a root cause of Himalayan forest fires. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Altering small and medium alcohol selectivity in the wax ester synthase.

    Science.gov (United States)

    Barney, Brett M; Ohlert, Janet M; Timler, Jacobe G; Lijewski, Amelia M

    2015-11-01

    The bifunctional wax ester synthase/acyl-coenzyme A:diacylglycerol acyltransferase (WS/DGAT or wax ester synthase) catalyzes the terminal reaction in the bacterial wax ester biosynthetic pathway, utilizing a range of alcohols and fatty acyl-CoAs to synthesize the corresponding wax ester. The wild-type wax ester synthase Maqu_0168 from Marinobacter aquaeolei VT8 exhibits a preference for longer fatty alcohols, while applications with smaller alcohols would yield products with desired biotechnological properties. Small and medium chain length alcohol substrates are much poorer substrates for the native enzyme, which may hinder broad application of the wax ester synthase in many proposed biosynthetic schemes. Developing approaches to improve enzyme activity toward specific smaller alcohol substrates first requires a clear understanding of which amino acids of the primary sequences of these enzymes contribute to substrate specificity in the native enzyme. In this report, we surveyed a range of potential residues and identified the leucine at position 356 and methionine at position 405 in Maqu_0168 as residues that affected selectivity toward small, branched, and aromatic alcohols when substituted with different amino acids. This analysis provides evidence of residues that line the binding site for wax ester synthase, which will aid rational approaches to improve this enzyme with specific substrates.

  7. Comparative Analyses of Cuticular Waxes on Various Organs of Potato (Solanum tuberosum L.).

    Science.gov (United States)

    Guo, Yanjun; Jetter, Reinhard

    2017-05-17

    Complex mixtures of cuticular waxes coat plant surfaces to seal them against environmental stresses, with compositions greatly varying between species and possibly organs. This paper reports comprehensive analyses of the waxes on both above- and below-ground organs of potato, where total wax coverages varied between petals (2.6 μg/cm(2)), leaves, stems, and tubers (1.8-1.9 μg/cm(2)), and rhizomes (1.1 μg/cm(2)). The wax mixtures on above-ground organs were dominated by alkanes, occurring in homologous series of isomeric C25-C35 n-alkanes, C25-C35 2-methylalkanes, and C26-C34 3-methylalkanes. In contrast, below-ground organs had waxes rich in monoacylglycerols (C22-C28 acyls) and C18-C30 alkyl ferulates, together with fatty acids (rhizomes) or primary alcohols (tubers). The organ-specific wax coverages, compound class distribution, and chain length profiles suggest highly regulated activities of wax biosynthesis enzymes, likely related to organ-specific ecophysiological functions.

  8. Molecular and Evolutionary Mechanisms of Cuticular Wax for Plant Drought Tolerance

    Directory of Open Access Journals (Sweden)

    Dawei Xue

    2017-04-01

    Full Text Available Cuticular wax, the first protective layer of above ground tissues of many plant species, is a key evolutionary innovation in plants. Cuticular wax safeguards the evolution from certain green algae to flowering plants and the diversification of plant taxa during the eras of dry and adverse terrestrial living conditions and global climate changes. Cuticular wax plays significant roles in plant abiotic and biotic stress tolerance and has been implicated in defense mechanisms against excessive ultraviolet radiation, high temperature, bacterial and fungal pathogens, insects, high salinity, and low temperature. Drought, a major type of abiotic stress, poses huge threats to global food security and health of terrestrial ecosystem by limiting plant growth and crop productivity. The composition, biochemistry, structure, biosynthesis, and transport of plant cuticular wax have been reviewed extensively. However, the molecular and evolutionary mechanisms of cuticular wax in plants in response to drought stress are still lacking. In this review, we focus on potential mechanisms, from evolutionary, molecular, and physiological aspects, that control cuticular wax and its roles in plant drought tolerance. We also raise key research questions and propose important directions to be resolved in the future, leading to potential applications of cuticular wax for water use efficiency in agricultural and environmental sustainability.

  9. Laser-produced plasma sensor-probe system for in situ molten metal analysis. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.W.

    1997-01-28

    The radically new methodology of in-situ laser-produced plasma (LPP) analysis of molten metals, as developed at Lehigh University, has been implemented into an LPP sensor-probe system, ready for deployment at steelmaking facilities. The system consists of an LPP sensor-probe head, which is immersed into the molten metal bath for the short duration of measurement, a control console, an umbilical cord connecting the above two units, and a support console providing coolants and pneumatic supports to the control console. The Department of Energy funding has supported Phase III-A and -B of the project in a joint sponsorship with AISI, CTU 5-2 Consortium, and Lehigh University. The objectives have been to: (1) implement the molten metal calibration protocol for the LPP analysis methodology; (2) implement the methodology in the form of a second-generation LPP sensor-probe system, which facilitates real-time process control by in-situ determination of elemental composition of molten steel alloys; (3) deploy such developmental systems in steelmaking facilities; (4) upgrade the systems to a third-generation design; and (5) effect technology transfer by selecting a manufacturer of commercial LPP sensor-probe systems. Four of the five objectives have been fully met. The deployment objective has been partially realized at present. The full LPP sensor-probe system has been put through trial immersion runs at a foundry, but its deployment at steelmaking facilities has progressed to a stage where various issues of financial and legal nature are being codified into a formal agreement between a host site and Lehigh University.

  10. Validation of the TRACE code for the system dynamic simulations of the molten salt reactor experiment and the preliminary study on the dual fluid molten salt reactor

    Energy Technology Data Exchange (ETDEWEB)

    He, Xun

    2016-06-14

    Molten Salt Reactor (MSR), which was confirmed as one of the six Generation IV reactor types by the GIF (Generation IV International Forum in 2008), recently draws a lot of attention all around the world. Due to the application of liquid fuels the MSR can be regarded as the most special one among those six GEN-IV reactor types in a sense. A unique advantage of using liquid nuclear fuel lies in that the core melting accident can be thoroughly eliminated. Besides, a molten salt reactor can have several fuel options, for instance, the fuel can be based on {sup 235}U, {sup 232}Th-{sup 233}U, {sup 238}U-{sup 239}Pu cycle or even the spent nuclear fuel (SNF), so the reactor can be operated as a breeder or as an actinides burner both with fast, thermal or epi-thermal neutron spectrum and hence, it has excellent features of the fuel sustainability and for the non-proliferation. Furthermore, the lower operating pressure not only means a lower risk of the explosion as well as the radioactive leakage but also implies that the reactor vessel and its components can be lightweight, thus lowering the cost of equipments. So far there is no commercial MSR being operated. However, the MSR concept and its technical validation dates back to the 1960s to 1970s, when the scientists and engineers from ORNL (Oak Ridge National Laboratory) in the United States managed to build and run the world's first civilian molten salt reactor called MSRE (Molten Salt Reactor Experiment). The MSRE was an experimental liquid-fueled reactor with 10 MW thermal output using {sup 4}LiF-BeF{sub 2}-ZrF{sub 4}-UF{sub 4} as the fuel also as the coolant itself. The MSRE is usually taken as a very important reference case for many current researches to validate their codes and simulations. Without exception it works also as a benchmark for this thesis. The current thesis actually consists of two main parts. The first part is about the validation of the current code for the old MSRE concept, while the second

  11. Bioinspired Composite Coating with Extreme Underwater Superoleophobicity and Good Stability for Wax Prevention in the Petroleum Industry.

    Science.gov (United States)

    Liang, Weitao; Zhu, Liqun; Li, Weiping; Yang, Xin; Xu, Chang; Liu, Huicong

    2015-10-13

    Wax deposition is a detrimental problem that happens during crude oil production and transportation, which greatly reduces transport efficiency and causes huge economic losses. To avoid wax deposition, a bioinspired composite coating with excellent wax prevention and anticorrosion properties is developed in this study. The prepared coating is composed of three films, including an electrodeposited Zn film for improving corrosion resistance, a phosphating film for constructing fish-scale morphology, and a silicon dioxide film modified by a simple spin-coating method for endowing the surface with superhydrophilicity. Good wax prevention performance has been investigated in a wax deposition test. The surface morphology, composition, wetting behaviors, and stability are systematically studied, and a wax prevention mechanism is proposed, which can be calculated from water film theory. This composite coating strategy which shows excellent properties in both wax prevention and stability is expected to be widely applied in the petroleum industry.

  12. Composition of macro- and microcrystalline paraffin waxes; Ueber die Zusammensetzung von makro- und mikrokristallinen Paraffinen

    Energy Technology Data Exchange (ETDEWEB)

    Matthaei, M.; Butz, Th. [Schuemann Sasol GmbH, Hamburg (Germany); Geissler, A. [Hochschule Zittau/Goerlitz (Germany)

    2002-09-01

    This paper reviews investigations into the composition of macro- and micro-crystalline paraffin waxes, focussed on the structure of non n-alkanes. The review covers a wide spectrum of investigations from the last 50 years. Applied analytical methods and results of paraffin wax analysis are compiled. The knowledge about qualitative and quantitative composition of non n-alkanes in paraffin waxes is mainly based on older publications. These results are differing from each other since different products and different analytical methods have been used. The paper refers to ongoing investigations based on the current instrumental analytics. (orig.)

  13. Tectonic microplates in a wax model of sea-floor spreading

    Science.gov (United States)

    Katz, Richard F.; Ragnarsson, Rolf; Bodenschatz, Eberhard

    2005-01-01

    Rotating, growing microplates are observed in a wax analogue model of sea-floor spreading. Wax microplates are kinematically similar to sea-floor tectonic microplates in terms of spreading rate and growth rate. Furthermore, their spiral pseudofault geometry is quantitatively consistent with Schouten's oceanic microplate model. These results suggest that Schouten's edge-driven microplate model captures the kinematics of tectonic microplate evolution on Earth. Based on the wax observations, a theory for the nucleation of overlapping spreading centres, the precursors of tectonic microplates, is developed.

  14. Scientific Opinion on the re-evaluation of candelilla wax (E 902) as a food additive

    OpenAIRE

    2012-01-01

    The Panel on Food Additives and Nutrient Sources added to Food (ANS) delivers a scientific opinion re-evaluating the safety of candelilla wax (E 902). Candelilla wax (E 902) is authorised in the EU as a food additive as a glazing agent. It has been evaluated by the Scientific Committee on Food (SCF) and by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The JECFA and the SCF did not establish an Acceptable Daily Intake (ADI) but considered the use of candelilla wax as a glazing ...

  15. Caffeine and theobromine in epicuticular wax of Ilex paraguariensis A. St.-Hil.

    Science.gov (United States)

    Athayde, M L; Coelho, G C; Schenkel, E P

    2000-12-01

    Caffeine and theobromine were identified and quantified in leaf epicuticular waxes of Ilex paraguariensis A. St.-Hil. (Aquifoliaceae). The total epicuticular leaf wax content was ca. 0.5% on average of dry leaf weight. Epicuticular caffeine and theobromine contents varied from 0.16 to 127.6 microg/mg and from 0 to 9.5 microg/mg of wax, respectively. For some selected samples, the intracellular methylxanthine concentration was also determined. A positive correlation was found between inner and epicuticular caffeine contents.

  16. Hearing and evasive behavior in the greater wax moth, Galleria mellonella (Pyralidae)

    DEFF Research Database (Denmark)

    Skals, Niels; Surlykke, Annemarie

    2000-01-01

    Greater wax moths (Galleria mellonella L., Pyraloidea) use ultrasound sensitive ears to detect clicking conspeci®cs and echolocating bats. Pyralid ears have four sensory cells, A1±4. The audiogram of G. mellonella has best frequency at 60 kHz with a threshold around 47 dB sound pressure level. A1...... and A2 have almost equal thresholds in contrast to noctuids and geometrids. A3 responds at + 12 to + 16 dB relative to the A1 threshold. The threshold data from the A-cells give no indication of frequency discrimination in greater wax moths. Tethered greater wax moths respond to ultrasound with short...

  17. Purification of a jojoba embryo wax synthase, cloning of its cDNA, and production of high levels of wax in seeds of transgenic arabidopsis.

    Science.gov (United States)

    Lardizabal, K D; Metz, J G; Sakamoto, T; Hutton, W C; Pollard, M R; Lassner, M W

    2000-03-01

    Wax synthase (WS, fatty acyl-coenzyme A [coA]: fatty alcohol acyltransferase) catalyzes the final step in the synthesis of linear esters (waxes) that accumulate in seeds of jojoba (Simmondsia chinensis). We have characterized and partially purified this enzyme from developing jojoba embryos. A protein whose presence correlated with WS activity during chromatographic fractionation was identified and a cDNA encoding that protein was cloned. Seed-specific expression of the cDNA in transgenic Arabidopsis conferred high levels of WS activity on developing embryos from those plants. The WS sequence has significant homology with several Arabidopsis open reading frames of unknown function. Wax production in jojoba requires, in addition to WS, a fatty acyl-CoA reductase (FAR) and an efficient fatty acid elongase system that forms the substrates preferred by the FAR. We have expressed the jojoba WS cDNA in Arabidopsis in combination with cDNAs encoding the jojoba FAR and a beta-ketoacyl-CoA synthase (a component of fatty acid elongase) from Lunaria annua. (13)C-Nuclear magnetic resonance analysis of pooled whole seeds from transgenic plants indicated that as many as 49% of the oil molecules in the seeds were waxes. Gas chromatography analysis of transmethylated oil from individual seeds suggested that wax levels may represent up to 70% (by weight) of the oil present in those seeds.

  18. A new form of MgTa2O6 obtained by the molten salt method

    Indian Academy of Sciences (India)

    Ashok K Ganguli; Shikha Nangia; A Meganathan Thirumala; Pratibha L Gai

    2006-01-01

    Using molten salt route (with NaCl/KCl as the salt) we have been able to synthesize a new form of magnesium tantalate at 850°C. Powder X-ray diffraction data could be indexed on an orthorhombic unit cell with lattice parameters, `' = 15.36(1) Å, ‘’ = 13.38(1) Å and ‘’ = 12.10(1) Å. High resolution transmission electron microscopy and electron diffraction studies confirm the results obtained by X-ray studies. Energy dispersive X-ray spectroscopy helps ascertain the composition of MgTa2O6. The title compound shows a dielectric constant of ∼ 24 with a low dielectric loss of 0.006 at 100 kHz at room temperature. Dielectric constant is nearly unchanged with rise in temperature while the loss shows a very marginal increase (0.007 at 300°C).

  19. Passive compact molten salt reactor (PCMSR), modular thermal breeder reactor with totally passive safety system

    Energy Technology Data Exchange (ETDEWEB)

    Harto, Andang Widi [Engineering Physics Department, Faculty of Engineering, Gadjah Mada University (Indonesia)

    2012-06-06

    Design Study Passive Compact Molten Salt Reactor (PCMSR) with totally passive safety system has been performed. The term of Compact in the PCMSR name means that the reactor system is designed to have relatively small volume per unit power output by using modular and integral concept. In term of modular, the reactor system consists of three modules, i.e. reactor module, turbine module and fuel management module. The reactor module is an integral design that consists of reactor, primary and intermediate heat exchangers and passive post shutdown cooling system. The turbine module is an integral design of a multi heating, multi cooling, regenerative gas turbine. The fuel management module consists of all equipments related to fuel preparation, fuel reprocessing and radioactive handling. The preliminary calculations show that the PCMSR has negative temperature and void reactivity coefficient, passive shutdown characteristic related to fuel pump failure and possibility of using natural circulation for post shutdown cooling system.

  20. Ceramic anode catalyst for dry methane type molten carbonate fuel cell

    Science.gov (United States)

    Tagawa, T.; Yanase, A.; Goto, S.; Yamaguchi, M.; Kondo, M.

    Oxide catalyst materials for methane oxidation were examined in order to develop the anode electrode for molten carbonate type fuel cell (MCFC). As a primary selection, oxides such as lanthanum (La 2O 3) and samarium (Sm 2O 3) were selected from screening experiments of TPD, TG and tubular reactor. Composite materials of these oxides with titanium fine powder were assembled into a cell unit for MCFC as the anode electrode. Steady-state activities were observed with these anode electrode materials when hydrogen was used as a fuel. When methane was directly charged to anode as a fuel (dry methane operation), a power generation with steady state was observed on both lanthanum and samarium composites after gradual decrease of open circuit electromotive force (OCV) and closed circuit current (CCI). The steady-state activity held as long as 144 h of continuous operation.

  1. Development and Field Test of New Oil-in-Water Wax Remover%新型水包油清蜡剂的研制及现场试验

    Institute of Scientific and Technical Information of China (English)

    展转盈; 倪军

    2015-01-01

    The effect of wax remover is critical for wax removing of oil wells. For the high toxicity, flammability, low wax dissolution rate and other shortcomings of commonly used wax removers, we developed a new type of oil-in-water wax re-mover in lab and tested in oilfields. We made experiment plans about the influence of different additives and their content on wax removing efficiency in oil-in-water wax removers, and determined the best formula consisting of 55% mixed organic solvent, 17% compound surfactant, 10% hexanol, 2% sodium chloride, 3. 5% sodium formate and water. Performance pa-rameters showed that the new wax remover was superior to conventional oil-based one. Test results of two groups of wells in-dicated that the load of a single well pumping unit could be reduced by 25. 07% and 48. 01% respectively after being added into oil-in-water wax remover, 20% and 33% higher than that of adjacent wells with conventional wax remover. The load was reduced remarkably and the application results were good. The new wax remover featured in high wax dissolution effi-ciency, low cost, good environmental protection, and broad prospect for application.%清蜡剂的效果对油井清蜡作业至关重要, 针对现阶段常用清蜡剂毒性大、 易燃、 溶蜡效率低等缺点, 通过室内实验研制了一种新型水包油型清蜡剂, 并在油田进行了试验. 制订了水包油型清蜡剂中不同添加剂及其含量对清蜡效率影响的实验方案, 分析确定最佳配方为55%混合有机溶剂、 17%混合型表面活性剂、 10%正己醇、 2%氯化钠、 3. 5%甲酸盐加重剂及水. 多项性能参数表明, 该清蜡剂性能明显优于常规油基清蜡剂. 两组矿场对比试验井的试验结果表明, 加入水包油型清蜡剂的单井抽油机载荷量分别降低25. 07%和48. 01%, 较加入常规清蜡剂的邻井分别高出20个百分点和33个百分点, 载荷量降低明显,应用效果良好. 该新型清蜡剂溶蜡效率高、

  2. Molten Salts for High Temperature Reactors: University of Wisconsin Molten Salt Corrosion and Flow Loop Experiments -- Issues Identified and Path Forward

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwall; Matt Ebner; Manohar Sohal; Phil Sharpe; Thermal Hydraulics Group

    2010-03-01

    Considerable amount of work is going on regarding the development of high temperature liquid salts technology to meet future process needs of Next Generation Nuclear Plant. This report identifies the important characteristics and concerns of high temperature molten salts (with lesson learned at University of Wisconsin-Madison, Molten Salt Program) and provides some possible recommendation for future work

  3. Electrodeposition of alloys or compounds in molten salts and applications

    Directory of Open Access Journals (Sweden)

    Taxil P.

    2003-01-01

    Full Text Available This article deals with the different modes of preparation of alloys or intermetallic compounds using the electrodeposition in molten salts, more particularly molten alkali fluorides. The interest in this process is to obtain new materials for high technology, particularly the compounds of reactive components such as actinides, rare earth and refractory metals. Two ways of preparation are considered: (i electrocoating of the more reactive metal on a cathode made of the noble one and reaction between the two metals in contact, and (ii electrocoating on an inert cathode of the intermetallic compound by coreduction of the ions of each elements. The kinetic is controlled by the reaction at the electrolyte interface. A wide bibliographic survey on the preparation of various compounds (intermetallic compounds, borides, carbides… is given and a special attention is paid to the own experience of the authors in the preparation of these compounds and interpretation of their results.

  4. Deoxidation Behavior of Alloys Bearing Barium in Molten Steel

    Institute of Scientific and Technical Information of China (English)

    LI Yang; JIANG Zhou-hua; JIANG Mao-fa; WANG Jun-wen; GU Wen-bing

    2003-01-01

    The deoxidation behaviors of alloys bearing barium in pipe steel were researched with MgO crucible under argon atmosphere in MoSi2 furnace at 1 873 K. The total oxygen contents of molten steel, the distribution, size and morphology of deoxidation products in the steel were surveyed. The metamorphic mechanism for deoxidation products of alloy bearing barium was also discussed. The results show that applying alloy bearing barium to the pipe steel, very low total oxygen contents can be obtained, and deoxidation products, which easily float up from molten steel, can be changed into globular shape and uniformly distributed in steel. The equilibrium time of total oxygen is about 25 min, and the terminal total oxygen contents range from 0.002 0 % to 0.002 2 % after treating with SiCa wire. The best deoxidizers are SiAlBaCa and SiAlBaCaSr.

  5. MAG-GATE System for Molten metal Flow Control

    Energy Technology Data Exchange (ETDEWEB)

    Richard D. Nathenson, P.E.

    2004-05-15

    The need for improved active flow control has been recognized as part of the Steel Industry Technology Roadmap. Under TRP 9808 for the American Iron and Steel Institute and the Department of Energy, Concept Engineering Group Inc. has developed MAG-GATE{trademark}, an electromagnetic system for active molten metal flow control. Two hot steel tests were successfully conducted in 2003 at the Whemco Foundry Division, Midland, PA. Approximately 110,000 pounds of 0.2% carbon steel were poured through the device subject to electromagnetic flow control. Excellent agreement between predicted and actual flow control was found. A survey of the molten metal flow control practices at 100 continuous casters in North America was also conducted in 2003. This report summarizes the results of the development program to date. Preliminary designs are described for the next step of a beta test at an operating billet/bloom or slab caster.

  6. Nuclear Hybrid Energy Systems: Molten Salt Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    P. Sabharwall; M. Green; S.J. Yoon; S.M. Bragg-Sitton; C. Stoots

    2014-07-01

    With growing concerns in the production of reliable energy sources, the next generation in reliable power generation, hybrid energy systems, are being developed to stabilize these growing energy needs. The hybrid energy system incorporates multiple inputs and multiple outputs. The vitality and efficiency of these systems resides in the energy storage application. Energy storage is necessary for grid stabilizing and storing the overproduction of energy to meet peak demands of energy at the time of need. With high thermal energy production of the primary nuclear heat generation source, molten salt energy storage is an intriguing option because of its distinct properties. This paper will discuss the different energy storage options with the criteria for efficient energy storage set forth, and will primarily focus on different molten salt energy storage system options through a thermodynamic analysis

  7. Plasma-sprayed ceramic coatings for protection against molten metal.

    Energy Technology Data Exchange (ETDEWEB)

    Hollis, K. J. (Kendall J.); Peters, M. I. (Maria I.); Bartram, B. D. (Brian D.)

    2002-01-01

    Molten metal environments pose a special demand on materials due to the high temperature corrosion effects and thermal expansion mismatch induced stress effects. A solution that has been successfully employed is the use of a base material for the mechanical strength and a coating material for the chemical compatibility with the molten metal. The work described here used such an approach coating tungsten rods with aluminum oxide, yttria-stabilized zirconia, yttrium oxide, and erbium oxide deposited by atmospheric plasma spraying. The ceramic materials were deposited under varying conditions to produce different structures. Measurement of particle characteristics was performed to correlate to material properties. The coatings were tested in a thermal cycling environment to simulate the metal melting cycle expected in service. Results of the testing indicate the effect of material composition and spray conditions on the thermal cycle crack resistance of the coatings.

  8. Molten metal analysis by laser produced plasmas. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong W.

    1994-02-01

    A new method of molten metal analysis, based on time- and space-resolved spectroscopy of a laser-produced plasma (LPP) plume of a molten metal surface, has been implemented in the form of a prototype LPP sensor-probe, allowing in-situ analysis in less than 1 minute. The research at Lehigh University has been structured in 3 phases: laboratory verification of concept, comparison of LPP method with conventional analysis of solid specimens and field trials of prototype sensor-probe in small-scale metal shops, and design/production/installation of two sensor-probes in metal production shops. Accomplishments in the first 2 phases are reported. 6 tabs, 3 figs.

  9. Development and Application of Refractory Materials for Molten Aluminum Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, James Gordon [ORNL; Headrick, William [University of Missouri, Rolla; Peters, Klaus-Markus [ORNL

    2008-01-01

    Two new refractory materials have been developed for use in molten aluminum contact applications which exhibit improved corrosion and wear resistance, along with improved thermal management through reduced heat losses. The development of these materials was based on understanding of the corrosion and wear mechanisms associated with currently used aluminum contact refractories through physical, chemical, and mechanical characterization and analysis performed by Oak Ridge National Laboratory (ORNL) and the University of Missouri, Rolla (UMR) along with their industrial partners, under the ITP Materials project "Multifunctional Metallic and Refractory Materials for Energy Efficient Handling of Molten Metals". Spent castable refractories obtained from a natural gas fired reverberatory aluminum alloy melting furnace were analyzed leading to identification of several refractory degradation mechanisms and strategies to produce improved materials. The newly developed materials have been validated through both R&D industrial trials and independent commercial trials by the refractory manufacturers.

  10. Uranium (III) precipitation in molten chloride by wet argon sparging

    Science.gov (United States)

    Vigier, Jean-François; Laplace, Annabelle; Renard, Catherine; Miguirditchian, Manuel; Abraham, Francis

    2016-06-01

    In the context of pyrochemical processes for nuclear fuel treatment, the precipitation of uranium (III) in molten salt LiCl-CaCl2 (30-70 mol%) at 705 °C is studied. First, this molten chloride is characterized with the determination of the water dissociation constant. With a value of 10-4.0, the salt has oxoacid properties. Then, the uranium (III) precipitation using wet argon sparging is studied. The salt is prepared using UCl3 precursor. At the end of the precipitation, the salt is totally free of solubilized uranium. The main part is converted into UO2 powder but some uranium is lost during the process due to the volatility of uranium chloride. The main impurity of the resulting powder is calcium. The consequences of oxidative and reductive conditions on precipitation are studied. Finally, coprecipitation of uranium (III) and neodymium (III) is studied, showing a higher sensitivity of uranium (III) than neodymium (III) to precipitation.

  11. A Reliable Reference Electrode in Molten Carbonate and Its Applications

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A Ag|AgCl reference electrode which can be used in molten carbonate media has been described in this paper.It consists of a silver wire immersed in a solution of AgCl(1mol%) in (Li0.62,K0.38)2CO3,with a zirconia junction.The main properties of reference electrode,such as reproducibility ,stability and reversibility, were checked.The results have demonstrated that the reference electrode is reliable.With such reference electrode catalysis of various electrode materials to oxygen reduction in molten alkali carbonate media was investigated.It is found that as catalysts for oxygen reduction oxidized nickel-niobium alloy is superior to nickel oxide.

  12. Cracking of crude oil in the molten metals

    Directory of Open Access Journals (Sweden)

    Marat A. Glikin

    2014-03-01

    Full Text Available In this paper is investigated the process of crude oil and its individual fractions cracking in the molten metals medium to produce light petroleum products. Thermodynamic calculations demonstrate the possibility of using lead and tin including alloys thereof as the melt. The cracking of West Siberian crude oil is studied at temperatures 400-600 °C. It is detected that as the temperature increases there is increase of aromatic hydrocarbons and olefins content in gasoline while naphthenes, n- and i-paraffins content reduces. Optimal temperature for cracking in molten metals is ~500 °C. The use of a submerged nozzle increases the yield of light petroleum products by ~2%. The research octane number of gasoline produced is 82-87 points. It is determined that the yield of light petroleum products depending on the experimental conditions is increased from 46.9 to 55.1-61.3% wt.   

  13. Comparison of ultrasonic wave speed measurements on wax at elevated temperatures to numerical method predictions

    Science.gov (United States)

    Moore, David G.; Stair, Sarah L.; Jack, David A.

    2017-02-01

    Ultrasonic stress wave amplitude and time-of-flight values may change as a media is heated. The measurement of relatively small variations in velocity and material attenuation can detect and quantify significant variations within a material's microstructure, such as a change in phase from solid to liquid. This paper discusses the experimental setup, ultrasonic wave speed tracking methods and signal analysis algorithms that are used in this study to document the changes within highly attenuative wax material as it is either being heated or cooled from 25°C to 90°C. The experimental set-up utilizes ultrasonic probes in a through-transmission configuration. The ultrasonic waveforms are recorded and analyzed during long duration thermal experiments. To complement the ultrasonic data, a Discontinuous-Galerkin Model (DGM) was also created, which uses unstructured meshes to determine how waves travel in this media and how the sound interacts with the prescribed boundary conditions. This numerical method solves particle motion travel using partial differential equations and outputs a wave trace per unit time. Both experimental and analytical data are presented and compared. The experimental and analytical data share some similarities; however, the differences between the two, including a high frequency component present in the analytical data that is not observed in the experimental data, are continuing to be studied and addressed in the model.

  14. High current density cathode for electrorefining in molten electrolyte

    Science.gov (United States)

    Li, Shelly X.

    2010-06-29

    A high current density cathode for electrorefining in a molten electrolyte for the continuous production and collection of loose dendritic or powdery deposits. The high current density cathode eliminates the requirement for mechanical scraping and electrochemical stripping of the deposits from the cathode in an anode/cathode module. The high current density cathode comprises a perforated electrical insulated material coating such that the current density is up to 3 A/cm.sup.2.

  15. Development of large scale internal reforming molten carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, A.; Shinoki, T.; Matsumura, M. [Mitsubishi Electric Corp., Hyogo (Japan)

    1996-12-31

    Internal Reforming (IR) is a prominent scheme for Molten Carbonate Fuel Cell (MCFC) power generating systems in order to get high efficiency i.e. 55-60% as based on the Higher Heating Value (HHV) and compact configuration. The Advanced Internal Reforming (AIR) technology has been developed based on two types of the IR-MCFC technology i.e. Direct Internal Reforming (DIR) and Indirect Internal Reforming (DIR).

  16. Molten carbonate fuel cell reduction of nickel deposits

    Energy Technology Data Exchange (ETDEWEB)

    Smith, James L. (Lemont, IL); Zwick, Stanley A. (Darien, IL)

    1987-01-01

    A molten carbonate fuel cell with anode and cathode electrodes and an eleolyte formed with two tile sections, one of the tile sections being adjacent the anode and limiting leakage of fuel gas into the electrolyte with the second tile section being adjacent the cathode and having pores sized to permit the presence of oxygen gas in the electrolyte thereby limiting the formation of metal deposits caused by the reduction of metal compositions migrating into the electrolyte from the cathode.

  17. Temperature Modeling of the Molten Glass in Tin Bath

    Institute of Scientific and Technical Information of China (English)

    WEI Zhihua; CHEN Jinshu; NIE Yingsong

    2009-01-01

    Based on the experimental investigation by quantitative analysis, temperature fields of the molten glass in tin bath were numerically simulated by the finite elememt method. The ex-perimental results show that the cooling rate of glass is directly proportional to the draught speed, but inversely proportional to the thickness of the glass. This model lays the foundation for computer simulation system about float glass.

  18. The structure of integument and wax glands of Phenacoccus fraxinus (Hemiptera: Coccoidea: Pseudococcidae)%The structure of integument and wax glands of Phenacoccus fraxinus (Hemiptera:Coccoidea:Pseudococcidae)

    Institute of Scientific and Technical Information of China (English)

    Yanfeng ZHANG; Yingping XIE; Jiaoliang XUE; Xiaohong FU; Weimin LIU

    2012-01-01

    Using scanning electron microscopy and optical microscopy,we studied the structure of the integument and wax glands of the mealybug,Phenacoccus fraxinus Tang (Hemiptera:Coccoidea:Pseudococcidae).We observed the ultrastructure of four wax pores including trilocular,quinquelocular,and multilocular pores as well as tubular ducts,recording characteristics of their structure,size and distribution.We found that that the integument of the mealybug consists of three main layers—the procuticle,epidermis and basement membrane—and four sub-layers of the procuticle—the epicuticle,exocuticle,endocuticle and formation zone.The waxsecreting gland cells were closely arranged in epidermis.All of them were complex and composed of one central cell and two or more lateral cells.These complex cells possess a large common reservoir for collection and storage.Synthesized by the glandular cells,the wax is excreted outside integument through canals.

  19. Matrix mini-tablets based on starch/microcrystalline wax mixtures.

    Science.gov (United States)

    De Brabander, C; Vervaet, C; Fiermans, L; Remon, J P

    2000-04-20

    Matrix mini-tablets based on a combination of microcrystalline waxes and starch derivatives were prepared using ibuprofen as a model drug. The production of mini-tablets was preferred over the production of pellets, as up-scaling of the pelletisation process seemed problematic. Prior to tabletting, melt granulation in a hot stage screw extruder and milling were required. The in vitro drug release was varied using microcrystalline waxes with a different melting range, the slowest drug release being obtained with a formulation containing a microcrystalline wax with a melting range between 68 and 72 degrees C. Generally speaking increasing the wax concentration resulted in a slower drug release. In vitro drug release profiles were also modified using different starches and mixtures of starches. Increasing the ibuprofen concentration to 70% resulted in a faster drug release rate.

  20. Development and properties of a wax ester hydrolase in the cotyledons of jojoba seedlings.

    Science.gov (United States)

    Huang, A H; Moreau, R A; Liu, K D

    1978-03-01

    The activity of a wax ester hydrolase in the cotyledons of jojoba (Simmondsia chinensis) seedlings increased drastically during germination, parallel to the development of the gluconeogenic process. The enzyme at its peak of development was obtained in association with the wax body membrane, and its properties were studied. It had an optimal activity at alkaline pH (8.5-9). The apparent K(m) value for N-methylindoxylmyristate was 93 muM. It was stable at 40 C for 30 min but was inactivated at higher temperature. Various divalent cations and ethylenediaminetetraacetate had little effect on the activity. p-Chloromercuribenzoate was a strong inhibitor of the enzyme activity, and its effect was reversed by subsequent addition of dithiothreitol. It had a broad substrate specificity with highest activities on monoglycerides, wax esters, and the native substrate (jojoba wax).

  1. The effect of the operating temperatures and the solubility of paraffin on wax deposition

    Energy Technology Data Exchange (ETDEWEB)

    Han, Shanpeng [Beijing Key Laboratory for Urban Oil and Gas Distribution Technology, China University of Petroleum (China); Huang, Zhenyu; Fogler, H. Scott [Department of Chemical Engineering, University of Michigan (United States)], email: sfogler@umich.edu; Hoffmann, Rainer [Heroya Research Centre, Statoil ASA (Norway)

    2010-07-01

    Over time, wax deposits accumulate in subsea pipelines, generating major flow problems for the petroleum industry. Different flow loop experiments with various operating temperatures were conducted. The wax can be stimulated at different axial positions in the subsea pipelines depending on the temperature. In this paper, a series of experiments were carried out based on different inlet temperatures and a model was applied. The experimental results concluded that deposit thickness increases as the temperature at the inlet decreases. These results were contradictory of previous studies. To further examine this inconsistency in the model, theoretical analysis was conducted using the fundamentals of transport phenomena, both oil and crude oil were used. According to the model, the temperature gradient at the interface and change of wax solubility are the two leading causes which contribute to wax deposits. In conclusion, the paper finds that no generalization can be made about the inlet temperature without considering other factors.

  2. Morphological and thermal evaluation of blends of polyethylene wax and paraffin

    Energy Technology Data Exchange (ETDEWEB)

    Akishino, J.K. [Graduate Program in Engineering and Materials Science, Federal University of Parana, Curitiba, PR (Brazil); Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil); Cerqueira, D.P. [Companhia de Eletricidade do Estado da Bahia—COELBA, Salvador, BA (Brazil); Silva, G.C. [Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil); Swinka-Filho, V. [Graduate Program in Engineering and Materials Science, Federal University of Parana, Curitiba, PR (Brazil); Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil); Munaro, M., E-mail: marilda@lactec.org.br [Graduate Program in Engineering and Materials Science, Federal University of Parana, Curitiba, PR (Brazil); Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil)

    2016-02-20

    Highlights: • Thermal properties of polyethylene wax and paraffin were investigated. • The blends were characterized by DSC, XRD and DMTA. • The melting temperatures were between those of the pure constituents. • The crystallinity decreased with addition of polyethylene wax. • The softening temperatures did not vary linearly with the composition. - Abstract: The thermal behavior and the morphology of blends of polyethylene wax and paraffin were investigated to evaluate the feasibility of using these materials to obtain a new temperature-indicating device to use in order to indicate failures in electrical connections due to overheating. The samples were evaluated with differential scanning calorimetry (DSC), X-ray diffraction (XRD) and dynamic mechanical thermal analysis (DMTA). The results showed that the crystallinity decreases as the concentration of polyethylene wax increases. In the compositions tested, the components were not miscible in the crystalline phase, and these compositions exhibited solid/liquid transitions at temperatures between those of the individual components.

  3. An improved index for the waxed stage of an implant-retained framework.

    Science.gov (United States)

    Adrian, E D; Krantz, W A; Ivanhoe, J R; Edge, M J

    1991-11-01

    A method for making an improved index for the waxed stage of Branemark implant-retained frameworks is described. The index improves visibility of the tooth and abutment cylinder relationship permitting the optimization of framework dimensions and contour.

  4. In search of low cost biological analysis: Wax or acrylic glue bonded paper microfluidic devices

    KAUST Repository

    Kodzius, Rimantas

    2011-11-04

    In this body of work we have been developing and characterizing paper based microfluidic fabrication technologies to produce low cost biological analysis. Specifically we investigated the performance of paper microfluidics that had been bonded using wax o

  5. The structure of integument and wax glands of Phenacoccus fraxinus (Hemiptera: Coccoidea: Pseudococcidae).

    Science.gov (United States)

    Zhang, Yanfeng; Xie, Yingping; Xue, Jiaoliang; Fu, Xiaohong; Liu, Weimin

    2012-06-01

    Using scanning electron microscopy and optical microscopy, we studied the structure of the integument and wax glands of the mealybug, Phenacoccus fraxinus Tang (Hemiptera: Coccoidea: Pseudococcidae). We observed the ultrastructure of four wax pores including trilocular, quinquelocular, and multilocular pores as well as tubular ducts, recording characteristics of their structure, size and distribution. We found that that the integument of the mealybug consists of three main layers-the procuticle, epidermis and basement membrane-and four sub-layers of the procuticle-the epicuticle, exocuticle, endocuticle and formation zone. The wax-secreting gland cells were closely arranged in epidermis. All of them were complex and composed of one central cell and two or more lateral cells. These complex cells possess a large common reservoir for collection and storage. Synthesized by the glandular cells, the wax is excreted outside integument through canals.

  6. Comparison of Super Stuff and paraffin wax bolus in radiation therapy of irregular surfaces.

    Science.gov (United States)

    Humphries, S M; Boyd, K; Cornish, P; Newman, F D

    1996-01-01

    Irregular facial contours can make radiation therapy of head and neck tumors difficult. Isodose lines become skewed, making treatment planning complex. A traditional solution to this problem is the paraffin wax box bolus. Such a bolus is made to fit the irregular surface compensating for the topology and creating an even surface. The fabrication of a wax bolus can be a difficult and time-consuming process. A method that is simple and efficient has been devised. Super Stuff bolus can be easily molded and has approximately the same effect as a similar paraffin wax bolus. This was verified by irradiating a Rando head phantom with both a paraffin wax bolus and a Super Stuff bolus. Doses to various points of interest were measured with thermoluminescent dosimetry (TLD) chips (LiF). The particular case addressed is malignant melanoma of the nasal septum, but the technique described can be useful in the treatment of other sites as well.

  7. 纯棉蜡印布生产工艺%Wax printing of cotton fabric

    Institute of Scientific and Technical Information of China (English)

    张玲

    2012-01-01

    生产工艺流程较长,质量难以控制,应在包括坯布采购、前处理、染色、甩蜡、染蜡纹、退蜡、印花及后整理等工序中注意各种可能影响产品质量的问题.文中阐述了纯棉蜡印布加工要点,分析了常见问题产生的原因,提出了解决方法.%Wax printing of cotton fabric is introduced, matters needing attention in following procedures are pointed out, including merchandising, pretreatment, waxing, cracking, dyeing, de-waxing, printing and finishing. The reasons for problems in wax printing are analyzed, and solutions are put forward.

  8. Vacuum/compression valving (VCV) using parrafin-wax on a centrifugal microfluidic CD platform.

    Science.gov (United States)

    Al-Faqheri, Wisam; Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Moebius, Jacob; Joseph, Karunan; Arof, Hamzah; Madou, Marc

    2013-01-01

    This paper introduces novel vacuum/compression valves (VCVs) utilizing paraffin wax. A VCV is implemented by sealing the venting channel/hole with wax plugs (for normally-closed valve), or to be sealed by wax (for normally-open valve), and is activated by localized heating on the CD surface. We demonstrate that the VCV provides the advantages of avoiding unnecessary heating of the sample/reagents in the diagnostic process, allowing for vacuum sealing of the CD, and clear separation of the paraffin wax from the sample/reagents in the microfluidic process. As a proof of concept, the microfluidic processes of liquid flow switching and liquid metering is demonstrated with the VCV. Results show that the VCV lowers the required spinning frequency to perform the microfluidic processes with high accuracy and ease of control.

  9. Technical review of Molten Salt Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    The process was reviewed for destruction of mixed low-level radioactive waste. Results: extensive development work and scaleup has been documented on coal gasification and hazardous waste which forms a strong experience base for this MSO process; it is clearly applicable to DOE wastes such as organic liquids and low-ash wastes. It also has potential for processing difficult-to-treat wastes such as nuclear grade graphite and TBP, and it may be suitable for other problem waste streams such as sodium metal. MSO operating systems may be constructed in relatively small units for small quantity generators. Public perceptions could be favorable if acceptable performance data are presented fairly; MSO will likely require compliance with regulations for incineration. Use of MSO for offgas treatment may be complicated by salt carryover. Figs, tabs, refs.

  10. Densities of molten Ni-(Cr, Co, W) superalloys

    Institute of Scientific and Technical Information of China (English)

    XIAO Feng; YANG Ren-hui; FANG Liang; LIU Lan-xiao; ZHAO Hong-kai

    2008-01-01

    In order to obtain more accurate density for molten Ni-(Cr, Co, W) binary alloy, the densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys were measured with a sessile drop method. It is found that the measured densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys decrease with increasing temperature in the experimental temperature range. The density of alloys increases with increasing W and Co concentrations while it decreases with increasing Cr concentration in the alloy at 1 773-1 873 K. The molar volume of Ni-based alloys increases with increasing W concentration while it decreases with increasing Co concentration. The effect of Cr concentration on the molar volume of the alloy is little in the studied concentration range. The accommodation among atomic species was analyzed. The deviation of molar volume from ideal mixing shows an ideal mixing of Ni-(Cr, Co, W) binary alloys.

  11. Removal of Inclusions from Molten Aluminum by Supergravity Filtration

    Science.gov (United States)

    Song, Gaoyang; Song, Bo; Yang, Zhanbing; Yang, Yuhou; Zhang, Jing

    2016-09-01

    A new approach to removing inclusions from aluminum melt by supergravity filtration was investigated. The molten aluminum containing MgAl2O4 spinel and coarse Al3Ti particles was isothermally filtered with different gravity coefficients, different filtering times, and various filtering temperatures under supergravity field. When the gravity coefficient G ≥ 50, the alloy samples were divided automatically into two parts: the upper residue and the lower filtered aluminum. All inclusions (MgAl2O4 and Al3Ti particles) were nearly intercepted in the upper residue by filter felt with average pore size of 44.78 μm. The removal efficiencies of oxide inclusions and Al3Ti particles exceeded 98 and 90 pct, respectively, at G ≥ 50, t = 2 minutes, T = 973 K (700 °C). Besides, the yield of purified aluminum was up to 92.1 pct at G = 600, t = 2 minutes, and T = 973 K (700 °C). The calculations of centrifugal pressure indicated that supergravity filtration could effectively overcome the pressure drop without meeting the rigorous requirement of height of molten metal, especially for using the fine-pore filter medium. Moreover, cake-mode filtration was the major mechanism of supergravity filtration of molten metal in this work.

  12. Removal of Inclusions from Molten Aluminum by Supergravity Filtration

    Science.gov (United States)

    Song, Gaoyang; Song, Bo; Yang, Zhanbing; Yang, Yuhou; Zhang, Jing

    2016-12-01

    A new approach to removing inclusions from aluminum melt by supergravity filtration was investigated. The molten aluminum containing MgAl2O4 spinel and coarse Al3Ti particles was isothermally filtered with different gravity coefficients, different filtering times, and various filtering temperatures under supergravity field. When the gravity coefficient G ≥ 50, the alloy samples were divided automatically into two parts: the upper residue and the lower filtered aluminum. All inclusions (MgAl2O4 and Al3Ti particles) were nearly intercepted in the upper residue by filter felt with average pore size of 44.78 μm. The removal efficiencies of oxide inclusions and Al3Ti particles exceeded 98 and 90 pct, respectively, at G ≥ 50, t = 2 minutes, T = 973 K (700 °C). Besides, the yield of purified aluminum was up to 92.1 pct at G = 600, t = 2 minutes, and T = 973 K (700 °C). The calculations of centrifugal pressure indicated that supergravity filtration could effectively overcome the pressure drop without meeting the rigorous requirement of height of molten metal, especially for using the fine-pore filter medium. Moreover, cake-mode filtration was the major mechanism of supergravity filtration of molten metal in this work.

  13. Uranium (III) precipitation in molten chloride by wet argon sparging

    Energy Technology Data Exchange (ETDEWEB)

    Vigier, Jean-François, E-mail: jean-francois.vigier@ec.europa.eu [CEA, Nuclear Energy Division, Radiochemistry & Processes Department, F-30207 Bagnols sur Cèze (France); Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, Univ. Lille Nord de France, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d' Ascq Cedex (France); Laplace, Annabelle [CEA, Nuclear Energy Division, Radiochemistry & Processes Department, F-30207 Bagnols sur Cèze (France); Renard, Catherine [Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, Univ. Lille Nord de France, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d' Ascq Cedex (France); Miguirditchian, Manuel [CEA, Nuclear Energy Division, Radiochemistry & Processes Department, F-30207 Bagnols sur Cèze (France); Abraham, Francis [Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, Univ. Lille Nord de France, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d' Ascq Cedex (France)

    2016-06-15

    In the context of pyrochemical processes for nuclear fuel treatment, the precipitation of uranium (III) in molten salt LiCl-CaCl{sub 2} (30–70 mol%) at 705 °C is studied. First, this molten chloride is characterized with the determination of the water dissociation constant. With a value of 10{sup −4.0}, the salt has oxoacid properties. Then, the uranium (III) precipitation using wet argon sparging is studied. The salt is prepared using UCl{sub 3} precursor. At the end of the precipitation, the salt is totally free of solubilized uranium. The main part is converted into UO{sub 2} powder but some uranium is lost during the process due to the volatility of uranium chloride. The main impurity of the resulting powder is calcium. The consequences of oxidative and reductive conditions on precipitation are studied. Finally, coprecipitation of uranium (III) and neodymium (III) is studied, showing a higher sensitivity of uranium (III) than neodymium (III) to precipitation. - Highlights: • Precipitation of Uranium (III) is quantitative in molten salt LiCl-CaCl{sub 2} (30–70 mol%). • The salt is oxoacid with a water dissociation constant of 10{sup −4.0} at 705 °C. • Volatility of uranium chloride is strongly reduced in reductive conditions. • Coprecipitation of U(III) and Nd(III) leads to a consecutive precipitation of the two elements.

  14. CO2 decomposition using electrochemical process in molten salts

    Science.gov (United States)

    Otake, Koya; Kinoshita, Hiroshi; Kikuchi, Tatsuya; Suzuki, Ryosuke O.

    2012-08-01

    The electrochemical decomposition of CO2 gas to carbon and oxygen gas in LiCl-Li2O and CaCl2-CaO molten salts was studied. This process consists of electrochemical reduction of Li2O and CaO, as well as the thermal reduction of CO2 gas by the respective metallic Li and Ca. Two kinds of ZrO2 solid electrolytes were tested as an oxygen ion conductor, and the electrolytes removed oxygen ions from the molten salts to the outside of the reactor. After electrolysis in both salts, the aggregations of nanometer-scale amorphous carbon and rod-like graphite crystals were observed by transmission electron microscopy. When 9.7 %CO2-Ar mixed gas was blown into LiCl-Li2O and CaCl2-CaO molten salts, the current efficiency was evaluated to be 89.7 % and 78.5 %, respectively, by the exhaust gas analysis and the supplied charge. When a solid electrolyte with higher ionic conductivity was used, the current and carbon production became larger. It was found that the rate determining step is the diffusion of oxygen ions into the ZrO2 solid electrolyte.

  15. Prebiotic formation of polyamino acids in molten urea

    Science.gov (United States)

    Mita, H.; Nomoto, S.; Terasaki, M.; Shimoyama, A.; Yamamoto, Y.

    2005-04-01

    It is important for research into the origins of life to elucidate polyamino acid formation under prebiotic conditions. Only a limited set of amino acids has been reported to polymerize thermally. In this paper we demonstrate a novel thermal polymerization mechanism in a molten urea of alkylamino acids (i.e. glycine, alanine, β-alanine, α-aminobutyric acid, valine, norvaline, leucine and norleucine), which had been thought to be incapable of undergoing thermal polymerization. Also, aspartic acid was found to polymerize in molten urea at a lower temperature than that at which aspartic acid alone had previously been thermally polymerized. Individual oligomers produced in heating experiments on urea-amino acid mixtures were analysed using a liquid chromatograph mass spectrometer. Major products in the reaction mixture were three different types of polyamino acid derivatives: N-carbamoylpolyamino acids, polyamino acids containing a hydantoin ring at the N-terminal position and unidentified derivatives with molecular weights that were greater by 78 than those of the corresponding peptide forms. The polymerization reaction occurred by taking advantage of the high polarity of molten urea as well as its dehydrating ability. Under the presumed prebiotic conditions employed here, many types of amino acids were thus revealed to undergo thermal polymerization.

  16. Development of electrochemical separation methods from molten fluoride salts

    Energy Technology Data Exchange (ETDEWEB)

    Straka, M.; Tulackova, R.; Chuchvalcova Bimova, K. [Nuclear Research Institute Rez plc, 250 68 Husinec, Rez 130, (Czech Republic)

    2008-07-01

    Molten Salt Reactor (MSR) is liquid-fueled reactor that can be used for actinide burning, production of electricity, production of hydrogen, and production of fissile fuels (breeding). The MSR concept was identified, along with five other concepts, as a suitable candidate of cooperative development by the Generation IV International Forum (GIF). The MSR concept takes into account a circulating molten fluoride salts fuel mixture. Use of liquid fuel mixture results in possibility of its continuous (online) reprocessing. Within the proposed MSR fuel cycle, the electro-separation methods are considered as important techniques. The main aim of this work is to determine the electrochemical behaviour of selected actinides and lanthanides, which represents the fissile material and fission products, in suitable molten fluoride media as the general framework of our work is to verify the separation capability of the electrochemical methods and proposal of its integration into the MSR fuel cycle. Presented results were obtained by the method of cyclic voltammetry. The experimental set-up, preparation of the melt and results of selected measurements are presented in this paper and electrochemical behaviour of uranium and selected lanthanides are demonstrated by respective voltammograms evaluation. (authors)

  17. Advances in electroanalysis, sensing and monitoring in molten salts.

    Science.gov (United States)

    Corrigan, Damion K; Elliott, Justin P; Blair, Ewen O; Reeves, Simon J; Schmüser, Ilka; Walton, Anthony J; Mount, Andrew R

    2016-08-15

    Microelectrodes have a number of advantages over macroelectrodes for quantitative electroanalysis and monitoring, including reduced iR drop, a high signal-to-noise ratio and reduced sensitivity to convection. Their use in molten salts has been generally precluded by the combined materials challenges of stresses associated with thermal cycling and physical and corrosive chemical degradation at the relatively high temperatures involved. We have shown that microfabrication, employing high precision photolithographic patterning in combination with the controlled deposition of materials, can be used to successfully address these challenges. The resulting molten salt compatible microelectrodes (MSMs) enable prolonged quantitative microelectrode measurements in molten salts (MSs). This paper reports the fabrication of novel MSM disc electrodes, chosen because they have an established ambient analytical response. It includes a detailed set of electrochemical characterisation studies which demonstrate both their enhanced capability over macroelectrodes and over commercial glass pulled microelectrodes, and their ability to extract quantitative electroanalytical information from MS systems. MSM measurements are then used to demonstrate their potential for shedding new light on the fundamental properties of, and processes in, MSs, such as mass transport, charge transfer reaction rates and the selective plating/stripping and alloying reactions of liquid Bi and other metals; this will underpin the development of enhanced MS industrial processes, including pyrochemical spent nuclear fuel reprocessing.

  18. Conceptual design of Indian molten salt breeder reactor

    Indian Academy of Sciences (India)

    P K Vijayan; A Basak; I V Dulera; K K Vaze; S Basu; R K Sinha

    2015-09-01

    The third stage of Indian nuclear power programme envisages the use of thorium as the fertile material with 233U, which would be obtained from the operation of Pu/Th-based fast reactors in the later part of the second stage. Thorium-based reactors have been designed in many configurations, from light water-cooled designs to high-temperature liquid metal-cooled options. Another option, which holds promise, is the molten salt-fuelled reactor, which can be configured to give significant breeding ratios. A crucial part for achieving reasonable breeding in such reactors is the need to reprocess the salt continuously, either online or in batch mode. India has recently started carrying out fundamental studies so as to arrive at a conceptual design of Indian molten salt breeder reactor (IMSBR). Presently, various design options and possibilities are being studied from the point of view of reactor physics and thermal hydraulic design. In parallel, fundamental studies on natural circulation and corrosion behaviour of various molten salts have also been initiated.

  19. Physico-chemical properties and efficacy of silk fibroin fabric coated with different waxes as wound dressing.

    Science.gov (United States)

    Kanokpanont, Sorada; Damrongsakkul, Siriporn; Ratanavaraporn, Juthamas; Aramwit, Pornanong

    2013-04-01

    Silk fibroin (SF) has been widely used as a wound dressing material due to its suitable physical and biological characteristics. In this study, a non-adhesive wound dressing which applies to cover the wound surface as an absorbent pad that would absorb wound fluid while accelerate wound healing was developed. The modification of SF fabrics by wax coating was purposed to prepare the non-adhesive wound dressing that is required in order to minimize pain and risk of repeated injury. SF woven fabrics were coated with different types of waxes including shellac wax, beeswax, or carnauba wax. Physical and mechanical properties of the wax-coated SF fabrics were characterized. It was clearly observed that all waxes could be successfully coated on the SF fabrics, possibly due to the hydrophobic interactions between hydrophobic domains of SF and waxes. The wax coating improved tensile modulus and percentage of elongation of the SF fabrics due to the denser structure and the thicker fibers coated. The in vitro degradation study demonstrated that all wax-coated SF fabrics remained up to 90% of their original weights after 7 weeks of incubation in lysozyme solution under physiological conditions. The wax coating did not affect the degradation behavior of the SF fabrics. A peel test of the wax-coated SF fabrics was carried out in the partial- and full-thickness wounds of porcine skin in comparison to that of the commercial wound dressing. Any wax-coated SF fabrics were less adhesive than the control, as confirmed by less number of cells attached and less adhesive force. This might be that the wax-coated SF fabrics showed the hydrophobic property, allowing the loosely adherence to the hydrophilic wound surface. In addition, the in vivo biocompatibility test of the wax-coated SF fabrics was performed in Sprague-Dawley rats with subcutaneous model. The irritation scores indicated that the carnauba wax-coated SF fabric was not irritant while the shellac wax or beeswax-coated SF

  20. Rewiring the wax ester production pathway of Acinetobacter baylyi ADP1.

    Science.gov (United States)

    Santala, Suvi; Efimova, Elena; Koskinen, Perttu; Karp, Matti Tapani; Santala, Ville

    2014-03-21

    Wax esters are industrially relevant high-value molecules. For sustainable production of wax esters, bacterial cell factories are suggested to replace the chemical processes exploiting expensive starting materials. However, it is well recognized that new sophisticated solutions employing synthetic biology toolbox are required to improve and tune the cellular production platform to meet the product requirements. For example, saturated wax esters with alkanol chain lengths C12 or C14 that are convenient for industrial uses are rare among bacteria. Acinetobacter baylyi ADP1, a natural producer of wax esters, is a convenient model organism for studying the potentiality and modifiability of wax esters in a natural host by means of synthetic biology. In order to establish a controllable production platform exploiting well-characterized biocomponents, and to modify the wax ester synthesis pathway of A. baylyi ADP1 in terms product quality, a fatty acid reductase complex LuxCDE with an inducible arabinose promoter was employed to replace the natural fatty acyl-CoA reductase acr1 in ADP1. The engineered strain was able to produce wax esters by the introduced synthetic pathway. Moreover, the fatty alkanol chain length profile of wax esters was found to shift toward shorter and more saturated carbon chains, C16:0 accounting for most of the alkanols. The study demonstrates the potentiality of recircuiting a biosynthesis pathway in a natural producer, enabling a regulated production of a customized bioproduct. Furthermore, the LuxCDE complex can be potentially used as a well-characterized biopart in a variety of synthetic biology applications involving the production of long-chain hydrocarbons.

  1. RDX-Polyethylene Wax Formulations as Potential Replacements for Tetryl in Fuze Leads, Boosters and Magazines

    Science.gov (United States)

    1986-08-01

    prepared by the solvent cut method, PBX-9407, are listed for comparison with RDX and Tetryl in Table 2. The substantial decrease in impact sensitivity...earliest MRL studies dealt with RDX grade ~ 1 1 % polyethylene wax as a potential replacement for beeswax in Comp. B RD~/~~~/ beeswax 60:40:1 [6,71. Some... solvent or toxic vapours, and all major ingredients are of low toxicity. The polyethylene wax is readily available through local suppliers and the

  2. Sediment Dynamics in a Vegetated Tidally Influenced Interdistributary Island: Wax Lake, Louisiana

    Science.gov (United States)

    2017-07-01

    ER D C/ CH L TR -1 7- 12 Sediment Dynamics in a Vegetated Tidally Influenced Interdistributary Island: Wax Lake, Louisiana Co as ta l... a nd H yd ra ul ic s La bo ra to ry Richard Styles, Duncan Bryant, Joe Gailani, Jarrell Smith, Brandon M. Boyd, and Greg Snedden July 2017...client/default. ERDC/CHL TR-17-12 July 2017 Sediment Dynamics in a Vegetated Tidally Influenced Interdistributary Island: Wax Lake, Louisiana

  3. Plant leaf wax biomarkers capture gradients in hydrogen isotopes of precipitation from the Andes and Amazon

    Science.gov (United States)

    Feakins, Sarah J.; Bentley, Lisa Patrick; Salinas, Norma; Shenkin, Alexander; Blonder, Benjamin; Goldsmith, Gregory R.; Ponton, Camilo; Arvin, Lindsay J.; Wu, Mong Sin; Peters, Tom; West, A. Joshua; Martin, Roberta E.; Enquist, Brian J.; Asner, Gregory P.; Malhi, Yadvinder

    2016-06-01

    Plant leaf waxes have been found to record the hydrogen isotopic composition of precipitation and are thus used to reconstruct past climate. To assess how faithfully they record hydrological signals, we characterize leaf wax hydrogen isotopic compositions in forest canopy trees across a highly biodiverse, 3 km elevation range on the eastern flank of the Andes. We sampled the dominant tree species and assessed their relative abundance in the tree community. For each tree we collected xylem and leaf samples for analysis of plant water and plant leaf wax hydrogen isotopic compositions. In total, 176 individuals were sampled across 32 species and 5 forest plots that span the gradient. We find both xylem water and leaf wax δD values of individuals correlate (R2 = 0.8 and R2 = 0.3 respectively) with the isotopic composition of precipitation (with an elevation gradient of -21‰ km-1). Minimal leaf water enrichment means that leaf waxes are straightforward recorders of the isotopic composition of precipitation in wet climates. For these tropical forests we find the average fractionation between source water and leaf wax for C29n-alkanes, -129 ± 2‰ (s.e.m., n = 136), to be indistinguishable from that of temperate moist forests. For C28n-alkanoic acids the average fractionation is -121 ± 3‰ (s.e.m., n = 102). Sampling guided by community assembly within forest plots shows that integrated plant leaf wax hydrogen isotopic compositions faithfully record the gradient of isotopes in precipitation with elevation (R2 = 0.97 for n-alkanes and 0.60 for n-alkanoic acids). This calibration study supports the use of leaf waxes as recorders of the isotopic composition of precipitation in lowland tropical rainforest, tropical montane cloud forests and their sedimentary archives.

  4. Very long chain alkylresorcinols accumulate in the intracuticular wax of rye (Secale cereale L.) leaves near the tissue surface.

    Science.gov (United States)

    Ji, Xiufeng; Jetter, Reinhard

    2008-03-01

    Alkylresorcinols (ARs) are bioactive compounds occurring in many members of the Poaceae, likely at or near the surface of various organs. Here, we investigated AR localization within the cuticular wax layers of rye (Secale cereale) leaves. The total wax mixture from both sides of the leaves was found to contain primary alcohols (71%), alkyl esters (11%), aldehydes (5%), and small amounts (synthetic standard of nonadecylresorcinol. The alkyl side chains of the wax ARs contained odd numbers of carbons ranging from C19 to C27, with a prevalence of C21, C23 and C25. Waxes from both sides of the leaf, analyzed separately in a second experiment, comprised the same compound classes in similar relative amounts and with similar homolog patterns. Finally, the epicuticular and intracuticular wax layers were sampled separately from the abaxial side of the leaf. While ARs accounted for 2% of the intracuticular wax, they were not detectable in the epicuticular wax. The intracuticular wax was also slightly enriched in steroids, whereas the epicuticular layer contained more primary alcohols. All other wax constituents were distributed evenly between both wax layers.

  5. Characterization of Wax Esters by Electrospray Ionization Tandem Mass Spectrometry: Double Bond Effect and Unusual Product Ions.

    Science.gov (United States)

    Chen, Jianzhong; Green, Kari B; Nichols, Kelly K

    2015-08-01

    A series of different types of wax esters (represented by RCOOR') were systematically studied by using electrospray ionization (ESI) collision-induced dissociation tandem mass spectrometry (MS/MS) along with pseudo MS(3) (in-source dissociation combined with MS/MS) on a quadrupole time-of-flight (Q-TOF) mass spectrometer. The tandem mass spectra patterns resulting from dissociation of ammonium/proton adducts of these wax esters were influenced by the wax ester type and the collision energy applied. The product ions [RCOOH2](+), [RCO](+) and [RCO-H2O](+) that have been reported previously were detected; however, different primary product ions were demonstrated for the three wax ester types including: (1) [RCOOH2](+) for saturated wax esters, (2) [RCOOH2](+), [RCO](+) and [RCO-H2O](+) for unsaturated wax esters containing only one double bond in the fatty acid moiety or with one additional double bond in the fatty alcohol moiety, and (3) [RCOOH2](+) and [RCO](+) for unsaturated wax esters containing a double bond in the fatty alcohol moiety alone. Other fragments included [R'](+) and several series of product ions for all types of wax esters. Interestingly, unusual product ions were detected, such as neutral molecule (including water, methanol and ammonia) adducts of [RCOOH2](+) ions for all types of wax esters and [R'-2H](+) ions for unsaturated fatty acyl-containing wax esters. The patterns of tandem mass spectra for different types of wax esters will inform future identification and quantification approaches of wax esters in biological samples as supported by a preliminary study of quantification of isomeric wax esters in human meibomian gland secretions.

  6. Wax beads as cushioning agents during the compression of coated diltiazem pellets.

    Science.gov (United States)

    Vergote, G J; Kiekens, F; Vervaet, C; Remon, J P

    2002-11-01

    Placebo particles were mixed with film-coated diltiazem pellets to evaluate them as cushioning agents during tabletting in order to protect the film coat from damage. The cushioning properties of alpha-lactose monohydrate granules, microcrystalline cellulose pellets and wax/starch beads were evaluated by comparing the dissolution profile of the coated pellets before and after compression (compression force 10 kN). Only the tablet formulations containing wax/starch beads provided protection to the film coat. However, the dissolution rate of tablets formulated with waxy maltodextrin/paraffinic wax placebo beads was too slow as the tablets did not disintegrate. Adding 50% (w/w) drum-dried corn starch/Explotab/paraffinic wax beads to the formulation was the optimal amount of cushioning beads to provide sufficient protection for the film coat and yield disintegrating tablets. Using a compression simulator, the effect of precompression force and compression time on the dissolution rate was found to be insignificant. The diametral crushing strength of tablets containing 50% (w/w) drum-dried corn starch/Explotab/paraffinic wax beads was about 25.0 N (+/-0.3 N), with a friability of 0.4% (+/-0.04%). This study demonstrates that adding deformable wax pellets minimizes the damage to film-coated pellets during compression.

  7. The effect of wax on compaction of microcrystalline cellulose beads made by extrusion and spheronization.

    Science.gov (United States)

    Iloañusi, N O; Schwartz, J B

    1998-01-01

    The effect of wax on the deformation behavior and compression characteristics of microcrystalline cellulose (Avicel PH-101) and acetaminophen (APAP) beads is described. Beads of Avicel PH-101 and APAP formulations were prepared using extrusion and spheronization technology. A waxy material, glyceryl behenate, N.F. (Compritol), was added to the formulations in amounts ranging from 10% to 70% of total solid weight. Beads with a selected particle size range of 16-30 mesh were compressed with an instrumented single punch Manesty F press utilizing a 7/16-in. flat-faced tooling set. Compaction profiles were generated for the tablets to evaluate the effect of wax on the densification of beads containing wax. Beads made without wax (the control formulation) required greater compression forces to form cohesive tablets. As the amount of wax in the bead formulation was increased, the beads become more plastic and compressible. The Heckel equation which relates densification to compression pressure was used to evaluate the deformation mechanisms of the bead formulations. The analysis shows that as the level of wax in the bead formulation is increased, the yield pressure decreases, indicating that the beads densify by a plastic deformation mechanism.

  8. Prediction of wax buildup in 24 inch cold, deep sea oil loading line

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, R.G.; Sattler, R.E.; Tolonen, W.J.; Pitchford, A.C.

    1981-10-01

    When designing pipelines for cold environments, it is important to know how to predict potential problems due to wax deposition on the pipeline's inner surface. The goal of this work was to determine the rate of wax buildup and the maximum, equlibrium wax thickness for a North Sea field loading line. The experimental techniques and results used to evaluate the waxing potential of the crude oil (B) are described. Also, the theoretic model which was used for predicting the maximum wax deposit thickness in the crude oil (B) loading pipeline at controlled temperatures of 40 F (4.4 C) and 100 F (38 C), is illustrated. Included is a recommendation of a procedure for using hot oil at the end of a tanker loading period in order to dewax the crude oil (B) line. This technique would give maximum heating of the pipeline and should be followed by shutting the hot oil into the pipeline at the end of the loading cycle which will provide a hot oil soaking to help soften existing wax. 14 references.

  9. Epicuticular waxes from caatinga and cerrado species and their efficiency against water loss

    Directory of Open Access Journals (Sweden)

    Oliveira Antonio F. M.

    2003-01-01

    Full Text Available The effects of the contents and chemical composition of the foliar epicuticular waxes of species from the caatinga (Aspidosperma pyrifolium, Capparis yco, Maytenus rigida and Ziziphus joazeiro and cerrado (Aristolochia esperanzae, Didymopanax vinosum, Strychnos pseudoquina and Tocoyena formosa were evaluated as to the resistance to water loss by means of an experimental device constructed for this purpose. In general, the waxes of the caatinga species investigated were more efficient against water loss than cerrado species. Increase of the thickness of the waxy deposits from 40 to 90m g.cm-2 had no significant effect on the resistance to water loss. The chemistry of the wax constituents was shown to be an important factor to determine the degree of resistance to evaporation. n-Alkanes and alcoholic triterpenes were the most efficient barriers, while hentriacontan-16-one (a ketone and ursolic acid (an acid triterpene revealed lowefficiency. The higher efficiency of the waxes of the leaves from caatinga species (mainly those of C. yco and Z. joazeiro is probably accounted for the predominance of n-alkanes in their composition. The lower efficiency of the waxes of A. pyrifolium (caatinga, T. formosa and A. esperanzae (both species from the cerrado is probably a consequence of the predominance of triterpenoids in the waxes of the two former species and hentriacontan-16-one in the latter.

  10. Epicuticular waxes from caatinga and cerrado species and their efficiency against water loss.

    Science.gov (United States)

    Oliveira, Antonio F M; Meirelles, Sérgio T; Salatino, Antonio

    2003-12-01

    The effects of the contents and chemical composition of the foliar epicuticular waxes of species from the caatinga (Aspidosperma pyrifolium, Capparis yco, Maytenus rigida and Ziziphus joazeiro) and cerrado (Aristolochia esperanzae, Didymopanax vinosum, Strychnos pseudoquina and Tocoyena formosa) were evaluated as to the resistance to water loss by means of an experimental device constructed for this purpose. In general, the waxes of the caatinga species investigated were more efficient against water loss than cerrado species. Increase of the thickness of the waxy deposits from 40 to 90 microg.cm-2 had no significant effect on the resistance to water loss. The chemistry of the wax constituents was shown to be an important factor to determine the degree of resistance to evaporation. n-Alkanes and alcoholic triterpenes were the most efficient barriers, while hentriacontan-16-one (a ketone) and ursolic acid (an acid triterpene) revealed low efficiency. The higher efficiency of the waxes of the leaves from caatinga species (mainly those of C. yco and Z. joazeiro) is probably accounted for the predominance of n-alkanes in their composition. The lower efficiency of the waxes of A. pyrifolium (caatinga), T. formosa and A. esperanzae (both species from the cerrado) is probably a consequence of the predominance of triterpenoids in the waxes of the two former species and hentriacontan-16-one in the latter.

  11. Effect of leaf surface waxes on leaf colonization by Pantoea agglomerans and Clavibacter michiganensis.

    Science.gov (United States)

    Marcell, Lise M; Beattie, Gwyn A

    2002-12-01

    To evaluate the influence of leaf cuticular waxes on bacterial colonization of leaves, bacterial colonization patterns were examined on four glossy maize (Zea mays L.) mutants that were altered in their cuticular wax biosynthesis. Mutant gl3 was indistinguishable from the wild-type maize in its ability to foster colonization by the two bacterial species, Pantoea agglomerans and Clavibacter michiganensis subsp. nebraskensis. In contrast, the other three mutants supported the development of populations that significantly differed in size from those on the wild type. Mutant gl5 gl20 supported smaller populations of P. agglomerans, but not C. michiganensis, while mutant gl1 supported larger populations of C. michiganensis but not P. agglomerans. Mutant gl4 supported larger populations of both bacterial species. The exceptional ability of mutant gl4 to support bacterial colonization was hypothesized to result from the lower density of the crystalline waxes on gl4 than on the wild type, because a reduced crystal density could promote capillary water movement and water trapping among the wax crystals. This hypothesis was supported by the demonstration that the mechanical introduction of gaps among the wax crystals of the wild-type leaves resulted in the establishment of larger P. agglomerans populations on the altered leaves. These results provide the first direct evidence that leaf surface waxes affect bacterial leaf colonization at various stages of colonization and in a bacterial species-dependent manner.

  12. CLINICAL PROFILE AND MANAGEMENT AUDIT OF EAR WAX IMPACTION IN OWERRI, SOUTH EAST NIGERIA

    Directory of Open Access Journals (Sweden)

    IBIAM FA

    2014-10-01

    Full Text Available Ear wax impaction is a common daily otolaryngology clinic presentation cutting across age group, sex and race, yet our sub-region has little knowledge and research on this common disease. Objective: To clinically profile patients with ear wax and audit our current management practice in the Federal Medical Centre Owerri, South East Nigeria and to make recommendation where appropriate. Design. Hospital based retrospective study. Setting: Federal Medical Center Owerri, South East Nigeria. Subjects/Participants: Patients clinically diagnosed with ear wax impaction from January to December 2010. ResultsA total of 338 patients presented with ear wax, of the 3,375 patients that attended the ENT clinic during the period under review accounting for 10.01% prevalence rate. 150 (44.4% were males while 188 (55.6% were females giving a M:F ratio of 1:1.3. Commonest predisposing factor was cotton swab abuse in 26 (7.7% patients. Aural syringing after use of cerumenolytic agents in 272 (80.5% patients with wax impaction was the commonest treatment modality. There were no recorded complications. Conclusion: Ear wax impaction is a common clinical entity in our sub-region. Treatment is simple and safe; but ignorance remains a major challenge.

  13. Effect of monosodium methanarsonate application on cuticle wax content of cocklebur and cotton plants.

    Science.gov (United States)

    Keese, Renee J; Camper, N Dwight

    2006-01-01

    Leaf cuticle waxes were extracted from monosodium methanearsonate (MSMA)-resistant (R) and -susceptible (S) common cocklebur (Xanthium strumarium L.) and cotton (Gossypium hirsutum L.) plants at 0, 3, 5, and 7 days after treatment (DAT) following 1x and 2x MSMA applications. Wax constituents were analyzed by gas chromatography (GC) with flame ionization detection and compared to alkane and alcohol standards of carbon lengths varying from C21 to C30. Differences in waxes were calculated and reported as change per ng mm2-1. Tricosane (C23) was found to increase following MSMA applications. All other alkanes decreased by 7 DAT, with some showing a linear effect over time in the R-cocklebur. Alcohol constituents were also observed to decrease by 7 DAT. Total arsenic in the extracted wax fraction was determined, with greatest quantities detected in the R-cocklebur. Wax changes are not believed to play a role in cotton tolerance, since changes in cuticle concentrations were minimal. Cocklebur resistance to MSMA is not due to cuticle constituents; the wax changes are a secondary effect in response to herbicide application.

  14. The use of paraffin wax in a new solar cooker with inner and outer reflectors

    Directory of Open Access Journals (Sweden)

    Arabacigil Bihter

    2015-01-01

    Full Text Available In this paper, the potential use and effectiveness of paraffin wax in a new solar cooker was experimentally investigated during daylight and late evening hours. For these experiments, a cooker having an inner reflecting surface was designed, constructed by filling paraffin wax and metal shavings. The side- and sub-surface temperatures of the paraffin wax in the cooker are measured in the summer months of June and July. The thermal efficiency of the cooker was tested on different conditions. The results show that the optimum angle of the outer reflector is 30°. Here, the peak temperature of the paraffin wax in the solar cooker was 83.4 °C. The average solar radiation reflected makes a contribution of 9.26% to the temperature of paraffin wax with the outer reflector. The solar cooker with the outer reflector angle of 30° receives also reflected radiation from the inner reflectors. Besides, the heating time is decreased to approximately 1 hour. The designed solar cooker can be effectively used with 30.3% daily thermal efficiency and paraffin wax due to the amount of energy stored.

  15. 超级仿蜡印花%Super imitation wax printing

    Institute of Scientific and Technical Information of China (English)

    郑春耕

    2009-01-01

    Common imitation wax prints are difficult to obtain a realistic style of wax printing. Through comparing imitation wax printing with real wax printing, contactless pre-drying and far-infrared dryer are introduced to rotary screen printing machine, and drying house rebuilding is carried out. Super imitation wax printed fabric with real wax printed style is produced.%真蜡印花布的印花效果正反面完全一致,普通仿蜡印花布则难以获得逼真的蜡印风格,将无接触式预烘方式和远红外热辐射器引入刮刀式圆网印花机,对其烘房进行改造,解决了仿蜡印花透印与拖色的矛盾,生产出具有逼真蜡印风格的超级仿蜡印花布.

  16. Waxes and plastic film in relation to the shelf life of yellow passion fruit

    Directory of Open Access Journals (Sweden)

    Mota Wagner Ferreira da

    2003-01-01

    Full Text Available The high perishability of the yellow passion fruit (Passiflora edulis f. flavicarpa reduces its postharvest conservation and availability, mainly for in natura consumption. These losses of quality and commercial value occur due to the high respiration and loss of water. This work aimed to evaluate the influence of a modified atmosphere - wax emulsions and plastic film - on the shelf life of the yellow passion fruit. Plastic film (Cryovac D-955, 15 mum thickness reduced fresh weight loss and fruit wilting, kept higher fruit and rind weight and higher pulp osmotic potential over the storage period. However, it was not efficient in the control of rottenness. Sparcitrus wax (22-23% polyethylene/maleyc resin caused injury to the fruit, high fruit weight losses and wilting and resulted in lower pulp osmotic potential; this wax lead to a higher concentration of acid and a lower relation of soluble solids/acidity. Among the tested waxes, Fruit Wax (18-21% carnauba wax was the best, promoting reduced weight loss, wilting and rottenness.

  17. Mathematical Modeling of the Vacuum Circulation Refining Processof Molten Steel

    Institute of Scientific and Technical Information of China (English)

    魏季和

    2003-01-01

    The available studies in the literature on mathematical modeling of the vacuum circulation (RH) refining process of molten steel have briefly been reviewed. The latest advances obtained by the author with his research group have been Summarized. On the basis of the mass and momentum balances in the system, a new mathematical model for decarburization and degassing during the RH and RH-KTB refining processes of molten steel was proposed and developed. The refining roles of the three reaction sites, i.e. the up-snorkel zone, the droplet group and steel bath in the vacuum vessel, were considered in the model. It was assumed that the mass transfer of reactive components in the molten steel is the rate control step of the refining reactions. And the friction losses and drags of flows in the snorkels and vacuum vessel were all counted. The model was applied to the refining of molten steel in a multifunction RH degasser of 90 t capacity. The decarburization and degassing processes in the degasser under the RH and RH-KTB operating condi-tions were modeled and analyzed using this model. Besides, proceeded from the two-resistance mass transfer theory and the mass bal-ance of sulphur in the system, a kinetic model for the desulphurization by powder injection and blowing in the RH refining of molten steel was developed. Modeling and predictions of the process of injecting and blowing the lime based powder flux under assumed oper-ating modes with the different initial contents of sulphur and amounts of powder injected and blown in a RH degasser of 300 t capacity were carried out using the model. It was demonstrated that for the RH and RH-KTB refining processes, and the desulphurization by powder injection and blowing in the RH refining, the results predicted by the models were all in good agreement respectively with data from industrial experiments and practice. These models may be expected to offer some useful information and a reliable basis for de-termining and optimizing

  18. Effect of electromagnetic force on turbulent flow of molten metal in aluminum electrolysis cells

    Institute of Scientific and Technical Information of China (English)

    周萍; 梅炽; 周乃君; 姜昌伟

    2004-01-01

    The standard k-ε model was adopted to simulate the flow field of molten metal in three aluminum electrolysis cells with different anode risers. The Hartman number, Reynolds number and the turbulent Reynolds number of molten metal were calculated quantitatively. The turbulent Reynolds number is in the order of 103 , and Reynolds number is in the order of 104 if taking the depth of molten metal as the characteristic length. The results show that the molten metal flow is the turbulence of high Reynolds number, the turbulent Reynolds number is more appropriate than Reynolds number to be used to describe the turbulent characteristic of molten metal, and Hartman number displays very well that electromagnetic force inhibits turbulent motion of molten metal.

  19. Physical Modeling of the Vacuum Circulation Refining Process of Molten Steel

    Institute of Scientific and Technical Information of China (English)

    魏季和

    2003-01-01

    The available studies in the literature on physical modeling of the vacuum circulation (RH, i.e. Ruhrstahl-Heraeus) refining process of molten steel have briefly been reviewed. The latest advances made by the author with his research group have been summarized. Water modeling was employed to investigate the flow and mixing characteristics of molten steel under the RH and RH-KTB (Kawasaki top blowing) conditions and the mass transfer features between molten steel and powder particles in the RH-PTB (powder top blowing) refining. The geometric similarity ratio between the model and its prototype (a multifunction RH degasser of 90 t capacity) was 1:5. The effects of the related technological and structural factors were considered. These latest studies have revealed the flow and mixing characteristics of molten steel and the mass transfer features between molten steel and powder particles in these processes, and have provided a better understanding of the refining processes of molten steel.

  20. Ionic Conductivities of Molten CuI and AgI-CuI Mixtures

    Science.gov (United States)

    Tahara, Shuta; Shimakura, Hironori; Ohno, Satoru; Fukami, Takanori

    2017-08-01

    Ionic conductivities σ for molten CuI and AgI-CuI mixtures were measured in the temperature ranges of approximately 580-800 and 500-850 °C, respectively. The value of σ for molten CuI in the range is smaller than that for molten CuBr and CuCl. σ for molten AgI-CuI mixtures decreases with increasing CuI-concentration. The activation energies Ea for molten AgI-CuI system were determined from the analysis of temperature dependence of σ by using the by Arrhenius type equation. Ea for molten AgI-CuI gradually increase with increasing CuIconcentration.

  1. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2003-03-01

    The program efforts are focused on technology and system optimization for cost reduction, commercial design development, and prototype system field trials. The program is designed to advance the carbonate fuel cell technology from full-size field test to the commercial design. FuelCell Energy, Inc. (FCE) is in the later stage of the multiyear program for development and verification of carbonate fuel cell based power plants supported by DOE/NETL with additional funding from DOD/DARPA and the FuelCell Energy team. FCE has scaled up the technology to full-size and developed DFC{reg_sign} stack and balance-of-plant (BOP) equipment technology to meet product requirements, and acquired high rate manufacturing capabilities to reduce cost. FCE has designed submegawatt (DFC300A) and megawatt (DFC1500 and DFC3000) class fuel cell products for commercialization of its DFC{reg_sign} technology. A significant progress was made during the reporting period. The reforming unit design was optimized using a three-dimensional stack simulation model. Thermal and flow uniformities of the oxidant-In flow in the stack module were improved using computational fluid dynamics based flow simulation model. The manufacturing capacity was increased. The submegawatt stack module overall cost was reduced by {approx}30% on a per kW basis. An integrated deoxidizer-prereformer design was tested successfully at submegawatt scale using fuels simulating digester gas, coal bed methane gas and peak shave (natural) gas.

  2. Hybrid Molten Bed Gasifier for High Hydrogen Syngas Production

    Energy Technology Data Exchange (ETDEWEB)

    Rue, David [Gas Technology Institute, Des Plaines, IL (United States)

    2017-05-23

    The techno-economic analyses of the hybrid molten bed gasification technology and laboratory testing of the HMB process were carried out in this project by the Gas Technology Institute and partner Nexant, Inc. under contract with the US Department of Energy’s National Energy Technology Laboratory. This report includes the results of two complete IGCC and Fischer-Tropsch TEA analyses comparing HMB gasification with the Shell slagging gasification process as a base case. Also included are the results of the laboratory simulation tests of the HMB process using Illinois #6 coal fed along with natural gas, two different syngases, and steam. Work in this 18-month project was carried out in three main Tasks. Task 2 was completed first and involved modeling, mass and energy balances, and gasification process design. The results of this work were provided to Nexant as input to the TEA IGCC and FT configurations studied in detail in Task 3. The results of Task 2 were also used to guide the design of the laboratory-scale testing of the HMB concept in the submerged combustion melting test facility in GTI’s industrial combustion laboratory. All project work was completed on time and budget. A project close-out meeting reviewing project results was conducted on April 1, 2015 at GTI in Des Plaines, IL. The hybrid molten bed gasification process techno-economic analyses found that the HMB process is both technically and economically attractive compared with the Shell entrained flow gasification process. In IGCC configuration, HMB gasification provides both efficiency and cost benefits. In Fischer-Tropsch configuration, HMB shows small benefits, primarily because even at current low natural gas prices, natural gas is more expensive than coal on an energy cost basis. HMB gasification was found in the TEA to improve the overall IGCC economics as compared to the coal only Shell gasification process. Operationally, the HMB process proved to be robust and easy to operate. The burner

  3. Hydrophobic trichome layers and epicuticular wax powders in Bromeliaceae.

    Science.gov (United States)

    Pierce, S; Maxwell, K; Griffiths, H; Winter, K

    2001-08-01

    The distinctive foliar trichome of Bromeliaceae has promoted the evolution of an epiphytic habit in certain taxa by allowing the shoot to assume a significant role in the uptake of water and mineral nutrients. Despite the profound ecophysiological and taxonomic importance of this epidermal structure, the functions of nonabsorbent trichomes in remaining Bromeliaceae are not fully understood. The hypothesis that light reflection from these trichome layers provides photoprotection was not supported by spectroradiometry and fluorimetry in the present study; the mean reflectance of visible light from trichome layers did not exceed 6.4% on the adaxial surfaces of species representing a range of ecophysiological types nor was significant photoprotection provided by their presence. Several reports suggesting water repellency in some terrestrial Bromeliaceae were investigated. Scanning electron microscopy (SEM) and a new technique-fluorographic dimensional imaging (FDI)-were used to assess the interaction between aqueous droplets and the leaf surfaces of 86 species from 25 genera. In the majority of cases a dense layer of overlapping, stellate or peltate trichomes held water off the leaf epidermis proper. In the case of hydrophobic tank-forming tillandsioideae, a powdery epicuticular wax layer provided water repellency. The irregular architecture of these indumenta resulted in relatively little contact with water droplets. Most mesic terrestrial Pitcairnioideae examined either possessed glabrous leaf blades or hydrophobic layers of confluent trichomes on the abaxial surface. Thus, the present study indicates that an important ancestral function of the foliar trichome in Bromeliaceae was water repellency. The ecophysiological consequences of hydrophobia are discussed.

  4. Molten pool-lower head integrity. Heat transfer models including advanced numerical simulations (DNS)

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, J.M.; Bonnet, J.M.; Bernaz, L. [CEA Grenoble (France)

    2001-07-01

    Extensive studies have been performed to investigate the heat transfer within a molten corium pool (homogeneous, stratified and with miscibility gap): Synthesis of heat transfer correlations in molten pool (homogeneous and stratified), Focusing effect in stratified metal layer, DNS analysis of Rayleigh Benard instabilities at the top boundary; interpretation of the different convection regimes and exponents affecting the Rayleigh number in the heat transfer correlations, Molten pool model for corium presenting a miscibility gap. Condition for de-stratification. (authors)

  5. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2002-02-01

    The carbonate fuel cell promises highly efficient, cost-effective and environmentally superior power generation from pipeline natural gas, coal gas, biogas, and other gaseous and liquid fuels. FuelCell Energy, Inc. has been engaged in the development of this unique technology, focusing on the development of the Direct Fuel Cell (DFC{reg_sign}). The DFC{reg_sign} design incorporates the unique internal reforming feature which allows utilization of a hydrocarbon fuel directly in the fuel cell without requiring any external reforming reactor and associated heat exchange equipment. This approach upgrades waste heat to chemical energy and thereby contributes to a higher overall conversion efficiency of fuel energy to electricity with low levels of environmental emissions. Among the internal reforming options, FuelCell Energy has selected the Indirect Internal Reforming (IIR)--Direct Internal Reforming (DIR) combination as its baseline design. The IIR-DIR combination allows reforming control (and thus cooling) over the entire cell area. This results in uniform cell temperature. In the IIR-DIR stack, a reforming unit (RU) is placed in between a group of fuel cells. The hydrocarbon fuel is first fed into the RU where it is reformed partially to hydrogen and carbon monoxide fuel using heat produced by the fuel cell electrochemical reactions. The reformed gases are then fed to the DIR chamber, where the residual fuel is reformed simultaneously with the electrochemical fuel cell reactions. FuelCell Energy plans to offer commercial DFC power plants in various sizes, focusing on the subMW as well as the MW-scale units. The plan is to offer standardized, packaged DFC power plants operating on natural gas or other hydrocarbon-containing fuels for commercial sale. The power plant design will include a diesel fuel processing option to allow dual fuel applications. These power plants, which can be shop-fabricated and sited near the user, are ideally suited for distributed power

  6. Core-concrete molten pool dynamics and interfacial heat transfer. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin, A.S.

    1980-01-01

    Theoretical models are derived for the heat transfer from molten oxide pools to an underlying concrete surface and from molten steel pools to a general concrete containment. To accomplish this, two separate effects models are first developed, one emphasizing the vigorous agitation of the molten pool by gases evolving from the concrete and the other considering the insulating effect of a slag layer produced by concrete melting. The resulting algebraic expressions, combined into a general core-concrete heat transfer representation, are shown to provide very good agreement with experiments involving molten steel pours into concrete crucibles.

  7. Role of molten salt flux in melting of used beverage container (UBC) scrap

    Energy Technology Data Exchange (ETDEWEB)

    Ye, J.; Sahai, Y. [Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

    1995-12-31

    Recycling of aluminum scrap, such as Used Beverage Container (UBC) scrap is steadily increasing. In secondary remelting of such scrap, it is a common practice to use protective molten salt cover. An appropriate salt protects metal from oxidation, promotes coalescence of the suspended metal droplets, and separates clean metal from the oxide contamination. The molten salt also reacts with metal. This causes metal loss and change of resulting metal composition. In this paper, role of molten salt fluxes in melting of UBC scrap is discussed, and selection criteria for molten salt are provided.

  8. Numerical performance study of paraffin wax dispersed with alumina in a concentric pipe latent heat storage system

    Directory of Open Access Journals (Sweden)

    Valan Arasu Amirtham

    2013-01-01

    Full Text Available Latent heat energy storage systems using paraffin wax could have lower heat transfer rates during melting/freezing processes due to its inherent low thermal conductivity. The thermal conductivity of paraffin wax can be enhanced by employing high conductivity materials such as alumina (Al2O3. A numerical analysis has been carried out to study the performance enhancement of paraffin wax with nanoalumina (Al2O3 particles in comparison with simple paraffin wax in a concentric double pipe heat exchanger. Numerical analysis indicates that the charge-discharge rates of thermal energy can be greatly enhanced using paraffin wax with alumina as compared with a simple paraffin wax as PCM.

  9. A novel bifunctional wax ester synthase/acyl-CoA:diacylglycerol acyltransferase mediates wax ester and triacylglycerol biosynthesis in Acinetobacter calcoaceticus ADP1.

    Science.gov (United States)

    Kalscheuer, Rainer; Steinbüchel, Alexander

    2003-03-07

    Triacylglycerols (TAGs) and wax esters are neutral lipids with considerable importance for dietetic, technical, cosmetic, and pharmaceutical applications. Acinetobacter calcoaceticus ADP1 accumulates wax esters and TAGs as intracellular storage lipids. We describe here the identification of a bifunctional enzyme from this bacterium exhibiting acyl-CoA:fatty alcohol acyltransferase (wax ester synthase, WS) as well as acyl-CoA:diacylglycerol acyltransferase (DGAT) activity. Experiments with a knock-out mutant demonstrated the key role of the bifunctional WS/DGAT for biosynthesis of both storage lipids in A. calcoaceticus. This novel type of long-chain acyl-CoA acyltransferase is not related to known acyltransferases including the WS from jojoba (Simmondsia chinensis), the DGAT1 or DGAT2 families present in yeast, plants, and animals, and the phospholipid:diacylglycerol acyltransferase catalyzing TAG formation in yeast and plants. A large number of WS/DGAT-related proteins were identified in Mycobacterium and Arabidopsis thaliana indicating an important function of these proteins. WS and DGAT activity was demonstrated for the translational product of one WS/DGAT homologous gene from M. smegmatis mc(2)155. The potential of WS/DGAT to establish novel processes for biotechnological production of jojoba-like wax esters was demonstrated by heterologous expression in recombinant Pseudomonas citronellolis. The potential of WS/DGAT as a selective therapeutic target of mycobacterial infections is discussed.

  10. Molten salt oxidation of mixed waste: Preliminary bench-scale experiments without radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Haas, P.A.; Rudolph, J.C.; Bell, J.T.

    1994-06-01

    Molten salt oxidation (MSO) is a process in which organic wastes are oxidized by sparging them with air through a bed of molten sodium carbonate (bp 851 {degrees}C) at {ge} 900{degrees}C. This process is readily applicable to the mixed waste because acidic products from Cl, S, P, etc., in the waste, along with most metals and most radionuclides, are retained within the melt as oxides or salts. Rockwell International has studied the application of MSO to various wastes, including some mixed waste. A unit used by Rockwell to study the mixed waste treatment is presently in use at Oak Ridge National Laboratory (ORNL). ORNL`s studies to date have concentrated on chemical flowsheet questions. Concerns that were studied included carbon monoxide (CO) emissions, NO{sub x}, emissions, and metal retention under a variety of conditions. Initial experiments show that CO emissions increase with increasing NaCl content in the melt, increasing temperature, and increasing airflow. Carbon monoxide content is especially high (> 2000 ppm) with high chlorine content (> 10%). Thermal NO{sub x}, emissions are relatively low ( < 5 ppm) at temperatures < 1000{degrees}C. However, most (85--100%) of the nitrogen in the feed as organic nitrate or amine was released as NO{sub x}, The metal contents of the melt and of knockout pot samples of condensed salt show high volatilities of Cs as CsCl. Average condensed salt concentrations were 60% for barium and 100% for strontium and cobalt. The cerium disappeared -- perhaps from deposition on the alumina reactor walls.

  11. Wax on, wax off

    DEFF Research Database (Denmark)

    Bos, Nicky Peter Maria; Grinsted, Lena; Holman, Luke

    2011-01-01

    Social animals use recognition cues to discriminate between group members and non-members. These recognition cues may be conceptualized as a label, which is compared to a neural representation of acceptable cue combinations termed the template. In ants and other social insects, the label consists...

  12. Bone wax as a cause of a foreign body granuloma in a cranial defect: a case report.

    Science.gov (United States)

    Wolvius, E B; van der Wal, K G H

    2003-12-01

    Bone wax was used to stop bleeding of the diploic vessels after harvesting cranial bone for reconstruction of an orbital floor defect. After five months a fistula in the overlying skin of the donor site appeared and was eventually surgically explored. Remnants of bone wax and surrounding inflammatory tissue were removed and the fistula was excised. Histological examination revealed a foreign body granuloma. The use of bone wax and possible alternative local haemostatic agents and their complications are discussed.

  13. Production and characterization of vaginal suppositories with propolis wax as active agent to prevent and treat Fluor albus

    Science.gov (United States)

    Farida, Siti; Azizah, Nurul; Hermansyah, Heri; Sahlan, Muhamad

    2017-02-01

    Based on the content contained in propolis wax especially antimicrobial function, it can be analyzed that propolis wax had superiority for Fluor albus. This research was conducted on two formulation of vaginal suppositories with base, supplementary and active agent as a fixed variable: 2% propolis wax (% w/w). Evaluation of this research were weight variation, melting time, consistency, irritation effect test and physical and chemical stability test (organoleptic, pH and polyphenol content).

  14. The effect of material properties on growth rates of folding and boudinage: Experiments with wax models

    Science.gov (United States)

    Neurath, C.; Smith, R. B.

    The growth of unstable structures was studied experimentally in layered wax models. The rheological properties of the two wax types were determined independently by a series of cylinder compression tests. Both waxes enhibited (1) a non-Newtonian stress vs strain-rate relationship (2) strain softening and (3) temperature-dependent viscosity. The stress-strain-rate relationships approximated a power-law, with stress exponents of 5 for the microcrystalline wax and 1.8 for paraffin wax. Blocks of paraffin with a single embedded layer of microcrystalline wax were deformed in two-dimensional pure shear with the layer oriented either parallel to the compressive strain axis so that it shortened and folded, or perpendicular to that axis so that it would stretch and boundinage would form. The growth rates of tiny initial disturbances were measured. The growth rates for folding and boudinage were much higher than could be accounted for by theories assuming Newtonian material properties. Theories taking non-Newtonian behaviour into account (Smith, R. B. 1975. Bull. geol. Soc. Am.86, 1601-1609; Fletcher, R. C. 1974. Am. J. Sci.274, 1029-1043) better describe the folding growth rates. Boudinage, however, grew almost three times faster than would be predicted even by existing non-Newtonian theory. A possible reason for this discrepancy is that the waxes do not exhibit steady-state creep as assumed in the theory. We, therefore, extend the theory to include strain-softening. The crucial step in this theory is the use of a scalar measure of the deformation as a state variable in the constitutive law. In this way the isotropic manifestation of strain-softening can be taken into account. The analysis shows that strain-softening can lead to greatly increased boudinage growth rates while having little influence on the growth rates of folds, which is in agreement with the experiments.

  15. Dental students' preferences and performance in crown design: conventional wax-added versus CAD.

    Science.gov (United States)

    Douglas, R Duane; Hopp, Christa D; Augustin, Marcus A

    2014-12-01

    The purpose of this study was to evaluate dental students' perceptions of traditional waxing vs. computer-aided crown design and to determine the effectiveness of either technique through comparative grading of the final products. On one of twoidentical tooth preparations, second-year students at one dental school fabricated a wax pattern for a full contour crown; on the second tooth preparation, the same students designed and fabricated an all-ceramic crown using computer-aided design (CAD) and computer-aided manufacturing (CAM) technology. Projects were graded for occlusion and anatomic form by three faculty members. On completion of the projects, 100 percent of the students (n=50) completed an eight-question, five-point Likert scalesurvey, designed to assess their perceptions of and learning associated with the two design techniques. The average grades for the crown design projects were 78.3 (CAD) and 79.1 (wax design). The mean numbers of occlusal contacts were 3.8 (CAD) and 2.9(wax design), which was significantly higher for CAD (p=0.02). The survey results indicated that students enjoyed designing afull contour crown using CAD as compared to using conventional wax techniques and spent less time designing the crown using CAD. From a learning perspective, students felt that they learned more about position and the size/strength of occlusal contacts using CAD. However, students recognized that CAD technology has limits in terms of representing anatomic contours and excursive occlusion compared to conventional wax techniques. The results suggest that crown design using CAD could be considered as an adjunct to conventional wax-added techniques in preclinical fixed prosthodontic curricula.

  16. Enhanced ethanol production by removal of cutin and epicuticular waxes of wheat straw by plasma assisted pretreatment

    DEFF Research Database (Denmark)

    Kádár, Zsófia; Schultz-Jensen, Nadja; Jensen, J. S.

    2015-01-01

    The removal of cutin and epicuticular waxes of wheat straw by PAP (plasma assisted pretreatment) was investigated. Wax removal was observed by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) as chemical change on the surface of most intensively pretreated samples as well...... as with Scanning Electron Microscopy (SEM) imaging. Compounds resulting from wax degradation were analyzed in the washing water of PAP wheat straw. The wax removal enhanced enzymatic hydrolysis yield and, consequently, the efficiency of wheat straw conversion into ethanol. In total, PAP increased the conversion...

  17. LOW TEMPERATURE THERMAL DEBINDING BEHAVIOR OF WAX-BASED MULTI-COMPONENT BINDER FOR TUNGSTEN HEAVY ALLOY

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    To control the defects in thermal debinding stage, low temperature thermal debinding behavior of wax in the multi-component binder for tungsten heavy alloy was studied. The wax burnout temperature is below 250 ℃, at which the defects mainly occur. The debinding rate is controlled by the diffusion of wax in the polymer to the inner surface of pores and then to the external environment. The experiment proved the amount of removed wax as an exponential function of time, the reciprocal sample thickness and temperature coeffcient.

  18. Molecular Radiocarbon Dating of Tropical Lake Sediments: Insights into the Chronology of Leaf Wax Stable Isotope Records

    Science.gov (United States)

    Douglas, P. M.; Pagani, M.; Eglinton, T. I.; Brenner, M.; Curtis, J. H.; Hodell, D. A.

    2010-12-01

    Leaf wax δD and δ13C measurements in marine and lacustrine sediment cores are promising proxies for past climatic and environmental change. However, a number of studies of marine sediments indicate centennial to millennial scale offsets between the radiocarbon ages of leaf waxes and the age of surrounding sediments due to long-term storage of these lipids in soils. These offsets present a complication for the interpretation of leaf wax stable isotope records that has not been thoroughly addressed. We present leaf wax δD, δ13C and Δ14C values for a sediment core from Lake Chichancanab in southeastern Mexico. This lake was previously studied using mineralogical (gypsum) and carbonate isotopic (δ18O) climate proxies, which indicated a sequence of severe droughts from 750 to 1000 AD, coincident with the collapse of the Classic Maya civilization. A suite of leaf wax δD values was plotted against the original sediment core chronology, which was developed using radiocarbon dates on terrestrial macrofossils. The leaf wax results also indicated major hydrological variability over the past 3000 years, but were not temporally coherent with the other climate proxy records. Leaf wax radiocarbon ages are 400 to 1200 years older than terrestrial macrofossil radiocarbon ages from the same depths, suggesting that leaf waxes are retained in the watershed for extended periods prior to deposition in the lake. We fit a 2nd-order polynomial equation to the depth profile of leaf wax radiocarbon ages (r2 =0.99) and refit the leaf wax δD profile to this “leaf wax age model”. This approach yielded much greater coherence with mineralogical and carbonate isotopic proxy records, including evidence for a period of severe drought (35‰ D-enrichment) from 750 to 1000 A.D. Our results indicate that long-term storage of leaf waxes in drainage basin soils can lead to temporal inaccuracies in leaf wax stable isotope records. These inaccuracies, however, can be corrected using a

  19. Sensitivity and Uncertainty Study for Thermal Molten Salt Reactors

    Science.gov (United States)

    Bidaud, Adrien; Ivanona, Tatiana; Mastrangelo, Victor; Kodeli, Ivo

    2006-04-01

    The Thermal Molten Salt Reactor (TMSR) using the thorium cycle can achieve the GEN IV objectives of economy, safety, non-proliferation and durability. Its low production of higher actinides, coupled with its breeding capabilities - even with a thermal spectrum - are very valuable characteristics for an innovative reactor. Furthermore, the thorium cycle is more flexible than the uranium cycle since only a small fissile inventory (reactor. The potential of these reactors is currently being extensively studied at the CNRS and EdF /1,2/. A simplified chemical reprocessing is envisaged compared to that used for the former Molten Salt Breeder Reactor (MSBR). The MSBR concept was developed at Oak Ridge National Laboratory (ORNL) in the 1970's based on the Molten Salt Reactor Experiment (MSRE). The main goals of our current studies are to achieve a reactor concept that enables breeding, improved safety and having chemical reprocessing needs reduced and simplified as much as reasonably possible. The neutronic properties of the new TMSR concept are presented in this paper. As the temperature coefficient is close to zero, we will see that the moderation ratio cannot be chosen to simultaneously achieve a high breeding ratio, long graphite lifetime and low uranium inventory. It is clear that any safety margin taken due to uncertainty in the nuclear data will significantly reduce the capability of this concept, thus a sensitivity analysis is vital to propose measurements which would allow to reduce at present high uncertainties in the design parameters of this reactor. Two methodologies, one based on OECD/NEA deterministic codes and one on IPPE (Obninsk) stochastic code, are compared for keff sensitivity analysis. The uncertainty analysis of keff using covariance matrices available in evaluated files has been performed. Furthermore, a comparison of temperature coefficient sensitivity profiles is presented for the most important reactions. These results are used to review the

  20. STRUCTURING & RHEOLOGY OF MOLTEN POLYMER/CLAY NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Yuan-ze Xu; Yi-bin Xu

    2005-01-01

    The evolution and the origin of "solid-like state" in molten polymer/clay nanocomposites are studied. Using polypropylene/clay hybrid (PPCH) with sufficient maleic anhydride modified PP (PP-MA) as compatibilizer, well exfoliation yet solid-like state was achieved after annealing in molten state. Comprehensive linear viscoelasticity and non-linear rheological behaviors together with WAXD and TEM are studied on PPCH at various dispersion stages focusing on time,temperature and deformation dependencies of the "solid-like" state in molten nanocomposites. Based on these, it is revealed that the solid-structure is developed gradually along with annealing through the stages of inter-layer expansion by PP-MA,the diffusion and association of exfoliated silicate platelets, the formation of band/chain structure and, finally, a percolated clay associated network, which is responsible for the melt rigidity or solid-like state. The network will be broken down by melt frozen/crystallization and weakened at large shear or strong flow and, even more surprisingly, may be disrupted by using trace amount of silane coupling agent which may block the edge interaction of platelets. The solid-like structure causes characteristic non-linear rheological behaviors, e.g. residual stress after step shear, abnormal huge stress overshoots in step flows and, most remarkably, the negative first normal stress functions in steady shear or step flows. The rheological and structural arguments challenge the existing models of strengthened entangled polymer network by tethered polymer chains connecting clay particles or by chains in confined melts or frictional interaction among tactoids. A scheme of percolated networking of associated clay platelets, which may in band form of edge connecting exfoliated platelets, is suggested to explain previous experimental results.

  1. Helium-cooled molten-salt fusion breeder

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R.W.; Lee, J.D.; Fulton, F.J.; Huegel, F.; Neef, W.S. Jr.; Sherwood, A.E.; Berwald, D.H.; Whitley, R.H.; Wong, C.P.C.; Devan, J.H.

    1984-12-01

    We present a new conceptual design for a fusion reactor blanket that is intended to produce fissile material for fission power plants. Fast fission is suppressed by using beryllium instead of uranium to multiply neutrons. Thermal fission is suppressed by minimizing the fissile inventory. The molten-salt breeding medium (LiF + BeF/sub 2/ + ThF/sub 4/) is circulated through the blanket and to the on-line processing system where /sup 233/U and tritium are continuously removed. Helium cools the blanket and the austenitic steel tubes that contain the molten salt. Austenitic steel was chosen because of its ease of fabrication, adequate radiation-damage lifetime, and low corrosion by molten salt. We estimate that a breeder having 3000 MW of fusion power will produce 6500 kg of /sup 233/U per year. This amount is enough to provide makeup for 20 GWe of light-water reactors per year or twice that many high-temperature gas-cooled reactors or Canadian heavy-water reactors. Safety is enhanced because the afterheat is low and blanket materials do not react with air or water. The fusion breeder based on a pre-MARS tandem mirror is estimated to cost $4.9B or 2.35 times a light-water reactor of the same power. The estimated cost of the /sup 233/U produced is $40/g for fusion plants costing 2.35 times that of a light-water reactor if utility owned or $16/g if government owned.

  2. Morphodynamics of a Bifurcation on the Wax Lake Delta, LA

    Science.gov (United States)

    Slingerland, R. L.; Best, J.; Parsons, D. R.; Edmonds, D. A.

    2009-12-01

    To better predict the dynamical behavior of fine-grained deltaic distributary networks, we collected integrated morphological, flow, and sediment transport data from a third-order bifurcation (BIF) on the Wax Lake Delta, LA, during July 15-20, 2009. Theory and numerical modeling predicts that over a range of channel aspect ratios, friction factors, and Shields numbers, three functions exist that relate the discharge ratio of the bifurcate arms at equilibrium conditions to the Shields number. One function predicts symmetrical configurations, while the other two predict asymmetrical discharges. To test the theoretical predictions we employed high-resolution multibeam echo sounding (MBES) and acoustic Doppler velocity profiling to map the bifurcation. The arms of the BIF are asymmetric in planform, depth (west arm/east arm = 4.2/3.1 m), discharge (335/140 cumecs), and bedload transport, with two-thirds of the dunes revealed on the MBES survey entering the western bifurcate channel. The bed consists of fine sand (D50 = 0.125 mm) sculpted into dunes, which in these 4 m water depths average 7 meters long and 0.52 m high and provide a form friction factor of about 0.028. Measured cross-sectional mean velocity of the main channel during the survey was ~ 0.23 m/s, which for sand-bed systems yields a low Shields number of θ = 0.093. For this θ theory predicts a stable equilibrium bifurcate discharge ratio of 4.5, which compares unfavorably with the observed value of 2.4. As there is no indication from 30 years of aerial photography that this BIF is morphologically unstable, either the bifurcation is maintained by the higher discharges of the spring flood or the theoretical envelope of stable bifurcation configurations requires re-evaluation.

  3. CAPTURING EXHAUST CO2 GAS USING MOLTEN CARBONATE FUEL CELLS

    Directory of Open Access Journals (Sweden)

    Prateek Dhawan

    2016-03-01

    Full Text Available Carbon dioxide is considered as one of the major contenders when the question of greenhouse effect arises. So for any industry or power plant it is of utmost importance to follow certain increasingly stringent environment protection rules and laws. So it is significant to keep eye on any possible methods to reduce carbon dioxide emissions in an efficient way. This paper reviews the available literature so as to try to provide an insight of the possibility of using Molten Carbonate Fuel Cells (MCFCs as the carbon capturing and segregating devices and the various factors that affect the performance of MCFCs during the process of CO2 capture.

  4. Precipitation of lamellar gold nanocrystals in molten polymers

    Science.gov (United States)

    Palomba, M.; Carotenuto, G.

    2016-05-01

    Non-aggregated lamellar gold crystals with regular shape (triangles, squares, pentagons, etc.) have been produced by thermal decomposition of gold chloride (AuCl) molecules in molten amorphous polymers (polystyrene and poly(methyl methacrylate)). Such covalent inorganic gold salt is high soluble into non-polar polymers and it thermally decomposes at temperatures compatible with the polymer thermal stability, producing gold atoms and chlorine radicals. At the end of the gold precipitation process, the polymer matrix resulted chemically modified because of the partial cross-linking process due to the gold atom formation reaction.

  5. Diffusion Welding of Alloys for Molten Salt Service - Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Denis Clark; Ronald Mizia; Piyush Sabharwall

    2012-09-01

    The present work is concerned with heat exchanger development for molten salt service, including the proposed molten salt reactor (MSR), a homogeneous reactor in which the fuel is dissolved in a circulating fluid of molten salt. It is an outgrowth of recent work done under the Next Generation Nuclear Plant (NGNP) program; what the two reactor systems have in common is an inherently safe nuclear plant with a high outlet temperature that is useful for process heat as well as more conventional generation The NGNP program was tasked with investigating the application of a new generation of nuclear power plants to a variety of energy needs. One baseline reactor design for this program is a high temperature, gas-cooled reactor (HTGR), which provides many options for energy use. These might include the conventional Rankine cycle (steam turbine) generation of electricity, but also other methods: for example, Brayton cycle (gas turbine) electrical generation, and the direct use of the high temperatures characteristic of HTGR output for process heat in the chemical industry. Such process heat is currently generated by burning fossil fuels, and is a major contributor to the carbon footprint of the chemical and petrochemical industries. The HTGR, based on graphite fuel elements, can produce very high output temperatures; ideally, temperatures of 900 °C or even greater, which has significant energy advantages. Such temperatures are, of course, at the frontiers of materials limitations, at the upper end of the performance envelope of the metallic materials for which robust construction codes exist, and within the realm of ceramic materials, the fabrication and joining of which, on the scale of large energy systems, are at an earlier stage of development. A considerable amount of work was done in the diffusion welding of materials of interest for HTGR service with alloys such as 617 and 800H. The MSR output temperature is also materials limited, and is projected at about 700

  6. Recovery of protactinium from molten fluoride nuclear fuel compositions

    Science.gov (United States)

    Baes, C.F. Jr.; Bamberger, C.; Ross, R.G.

    1973-12-25

    A method is provided for separating protactinium from a molten fluonlde salt composition consisting essentially of at least one alkali and alkaline earth metal fluoride and at least one soluble fluoride of uranium or thorium which comprises oxidizing the protactinium in said composition to the + 5 oxidation state and contacting said composition with an oxide selected from the group consisting of an alkali metal oxide, an alkaline earth oxide, thorium oxide, and uranium oxide, and thereafter isolating the resultant insoluble protactinium oxide product from said composition. (Official Gazette)

  7. Nanoporous surfaces via impact of molten metallic droplets

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Meng [Massachusetts Institute of Technology, Department of Materials Science and Engineering, Cambridge, MA (United States); Colmenares, Jose R.; Valarezo, Alfredo [State University of New York, Stony Brook (United States). Center for Thermal Spray Research; Gouldstone, Andrew [Northeastern University, Department of Mechanical and Industrial Engineering, Boston, MA (United States)

    2009-08-15

    Here we describe a new pathway for the production of nanoporous surfaces, by recourse to molten droplet impact and solidification. The nanopores in this case are frozen in bubbles that nucleate in the melt due to gas supersaturation within 100 nanoseconds of impact. Initial observations and previous analysis are presented, as well as ongoing work to control or pattern porosity via process variation and substrate pre-treatment. This method is presumably not limited in material, and has potential to create large area, functional surfaces. (orig.)

  8. Lithium-ferrate-based cathodes for molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lanagan, M.T.; Bloom, I.; Kaun, T.D. [Argonne National Lab., IL (United States)] [and others

    1996-12-31

    Argonne National Laboratory is developing advanced cathodes for pressurized operation of the molten carbonate fuel cell (MCFC) at {approximately}650{degrees}C. To be economically viable for stationary power generation, molten carbonate fuel cells must have lifetimes of more than 25,000 h while exhibiting superior cell performance. In the present technology, lithiated NiO is used as the cathode. Over the lifetime of the cell, however, N{sup 2+} ions tend to transport to the anode, where they are reduced to metallic Ni. With increased CO{sub 2} partial pressure, the transport of Ni increases because of the increased solubility of NiO in the carbonate electrolyte. Although this process is slow in MCFCs operated at 1 atm and a low CO{sub 2} partial pressure (about 0.1 atm), transport of nickel to the anode may be excessive at a higher pressure (e.g., 3 atm) and a high CO{sub 2} partial pressure (e.g., about 0.3 arm). This transport is expected to lead eventually to poor MCFC performance and/or short circuiting. Several alternative cathode compositions have been explored to reduce cathode solubility in the molten salt electrolyte. For example, LiCoO{sub 2} has been studied extensively as a potential cathode material. The LiCoO{sub 2} cathode has a low resistivity, about 10-cm, and can be used as a direct substitute for NiO. Argonne is developing advanced cathodes based on lithium ferrate (LiFeO{sub 2}), which is attractive because of its very low solubility in the molten (Li,K){sub 2}CO{sub 3} electrolyte. Because of its high resistivity (about 3000-cm), however, LiFeO{sub 2} cannot be used as a direct substitute for NiO. Cation substitution is, therefore, necessary to decrease resistivity. We determined the effect of cation substitution on the resistivity and deformation of LiFeO{sub 2}. The substituents were chosen because their respective oxides as well as LiFeO{sub 2} crystallize with the rock-salt structure.

  9. Boron removal from molten silicon using sodium-based slags

    Institute of Scientific and Technical Information of China (English)

    Yin Changhao; Hu Bingfeng; Huang Xinming

    2011-01-01

    Slag refining,as an important option for boron removal to produce solar grade silicon (SOG-Si) from metallurgical grade silicon (MG-Si),has attracted increasing attention.In this paper,Na2CO3-SiO2 systems were chosen as the sodium-based refining slag materials for boron removal from molten silicon.Furthermore,the effect of Al2O3 addition for boron removal was studied in detail,which showed that an appropriate amount of Al2O3 can help retention of the basicity of the slags,hence improving the boron removal rate.

  10. Dynamic modeling of Badaling molten salt tower CSP pilot plant

    Science.gov (United States)

    Yang, Zijiang; Lu, Jiahui; Zhang, Qiangqiang; Li, Zhi; Li, Xin; Wang, Zhifeng

    2017-06-01

    Under the collaboration framework between EDF China R&D Centre and CAS-IEE, a preliminary numerical model of 1MWth molten salt tower solar power demonstration plant in Badaling, Beijing is presented in this paper. All key components in the plant are presented throughout detailed modules in the model according to its design specifications. Control strategies are also implemented to maintain the design system performance at transient scenario. By this model some key design figures of plant has been validated and it will be used to guide experiment set-up and plant commissioning.

  11. Determination of optimum electrolyte composition for molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.Y.; Pigeaud, A.

    1987-01-01

    The goal of this program is the development of a molten carbonate fuel cell (MCFC) anode which is more tolerant of sulfur contaminants in the fuel than the current state-of-the-art nickel-based anode structures. This program addresses two different but related aspects of the sulfur contamination problem. The primary aspect is concerned with the development of a sulfur tolerant electrocatalyst for the fuel oxidation reaction. A secondary issue is the development of a sulfur tolerant water-gas-shift reaction catalyst and an investigation of potential steam reforming catalysts which also have some sulfur tolerant capabilities. These two aspects are being addressed as two separate tasks.

  12. Fundamental of Inclusion Removal from Molten Steel by Rising Bubble

    Institute of Scientific and Technical Information of China (English)

    WANG Li-tao; ZHANG Qiao-ying; LI Zheng-bang; XUE Zheng-liang

    2004-01-01

    The mechanism of inclusion removal by attachment to rising bubble was analyzed, and the movement behavior of inclusion, the mechanism of bubbles/inclusion interaction, collision probability and adhesion probability were discussed. A mathematical model of inclusion removal from molten steel by attachment to fine bubble was developed. The results of theoretical analysis and mathematical model showed that the optimum bubble diameter for inclusion removal is 1 to 2 mm. A new method that argon is injected into the shroud from ladle to tundish during continuous casting has been proposed to produce fine bubble. It provides theoretical guides for production of super clean steel.

  13. Diffusion Welding of Alloys for Molten Salt Service - Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Denis Clark; Ronald Mizia

    2012-05-01

    The present work is concerned with heat exchanger development for molten salt service, including the proposed molten salt reactor (MSR), a homogeneous reactor in which the fuel is dissolved in a circulating fluid of molten salt. It is an outgrowth of recent work done under the Next Generation Nuclear Plant (NGNP) program; what the two reactor systems have in common is an inherently safe nuclear plant with a high outlet temperature that is useful for process heat as well as more conventional generation The NGNP program was tasked with investigating the application of a new generation of nuclear power plants to a variety of energy needs. One baseline reactor design for this program is a high temperature, gas-cooled reactor (HTGR), which provides many options for energy use. These might include the conventional Rankine cycle (steam turbine) generation of electricity, but also other methods: for example, Brayton cycle (gas turbine) electrical generation, and the direct use of the high temperatures characteristic of HTGR output for process heat in the chemical industry. Such process heat is currently generated by burning fossil fuels, and is a major contributor to the carbon footprint of the chemical and petrochemical industries. The HTGR, based on graphite fuel elements, can produce very high output temperatures; ideally, temperatures of 900 C or even greater, which has significant energy advantages. Such temperatures are, of course, at the frontiers of materials limitations, at the upper end of the performance envelope of the metallic materials for which robust construction codes exist, and within the realm of ceramic materials, the fabrication and joining of which, on the scale of large energy systems, are at an earlier stage of development. A considerable amount of work was done in the diffusion welding of materials of interest for HTGR service with alloys such as 617 and 800H. The MSR output temperature is also materials limited, and is projected at about 700 C

  14. Steady thermal hydraulic analysis for a molten salt reactor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dalin; QIU Suizheng; LIU Changliang; SU Guanghui

    2008-01-01

    The Molten Salt Reactor (MSR) can meet the demand of transmutation and breeding. In this study, theoretical calculation of steady thermal hydraulic characteristics of a graphite-moderated channel type MSR is conducted. The DRAGON code is adopted to calculate the axial and radial power factor firstly. The flow and heat transfer model in the fuel salt and graphite are developed on basis of the fundamental mass, momentum and energy equations. The results show the detailed flow distribution in the core, and the temperature profiles of the fuel salt, inner and outer wall in the nine typical elements along the axial flow direction are also obtained.

  15. Measurements of Thermal Conductivity and Thermal Diffusivity of Molten Carbonates

    OpenAIRE

    Wicaksono, Hendro; Zhang, Xing; Fujiwara, Seiji; Fujii, Motoo

    2001-01-01

    The thermal conductivity and thermal diffusivity of molten carbonates (Li_2CO_3/K_2CO_3 and Li_2CO_3/Na_2CO_3) were measured using the transient short-hot-wire method in the temperature range from 530 to 670℃. Two types of probes were examined. One was a platinum short-hot-wire probe coated with alumina (Al_2O_3) thin film to prevent current leakage and corrosion. The other was a bare gold short-hot-wire probe. For the platinum probe, the quality of coating reduces gradually during the measur...

  16. ULTRASONIC SEPARATION OF MICRO-SIZED INCLUSIONSIN MOLTEN METAL

    Institute of Scientific and Technical Information of China (English)

    X.Q. Bai; J.C. He

    2001-01-01

    The coagulation time and position of micro-sized non-metallic inclusions in molten metal during ultrasonic separation process were investigated, and the motion course of micro-sized non-metallic inclusions in an ultrasonic standing wave field was numerically simulated. The results of theoretical analysis and numerical simulation show that the movement of inclusions depends on the balance between the acoustic radiation force, effective buoyancy force and viscous drag force. It is presented that micro-sized inclusions, agglomerated at antinode-planes may be removed further with horizon tal ultrasound.``

  17. Iron-Catalyzed Boron Removal from Molten Silicon in Ammonia

    Science.gov (United States)

    Chen, Zhiyuan; Morita, Kazuki

    2016-12-01

    A high-temperature process of refining metallurgical-grade silicon to solar-grade silicon was developed. In this gas purging treatment, boron impurity in silicon reacts with ammonia and the products are removed as volatiles at high temperature. 1 mass pct metallic iron was added to molten silicon as a catalyst, improving the boron removal ratio from 14 to 80 pct at 1723 K (1450 °C). At 1823 K (1550 °C), this reaction could reduce boron concentration from more than 120 ppmw to activation energy of 329 ± 129 kJ mol-1 was calculated from experimental data.

  18. Corrosion-Resistant Container for Molten-Material Processing

    Science.gov (United States)

    Stern, Theodore G.; McNaul, Eric

    2010-01-01

    In a carbothermal process, gaseous methane is passed over molten regolith, which is heated past its melting point to a temperature in excess of 1,625 C. At this temperature, materials in contact with the molten regolith (or regolith simulant) corrode and lose their structural properties. As a result, fabricating a crucible to hold the molten material and providing a method of contact heating have been problematic. Alternative containment approaches use a large crucible and limit the heat zone of the material being processed, which is inefficient because of volume and mass constraints. Alternative heating approaches use non-contact heating, such as by laser or concentrated solar energy, which can be inefficient in transferring heat and thus require higher power heat sources to accomplish processing. The innovation is a combination of materials, with a substrate material having high structural strength and stiffness and high-temperature capability, and a coating material with a high corrosion resistance and high-temperature capability. The material developed is a molybdenum substrate with an iridium coating. Creating the containment crucible or heater jacket using this material combination requires only that the molybdenum, which is easily processed by conventional methods such as milling, electric discharge machining, or forming and brazing, be fabricated into an appropriate shape, and that the iridium coating be applied to any surfaces that may come in contact with the corrosive molten material. In one engineering application, the molybdenum was fashioned into a container for a heat pipe. Since only the end of the heat pipe is used to heat the regolith, the container has a narrowing end with a nipple in which the heat pipe is snugly fit, and the external area of this nipple, which contacts the regolith to transfer heat into it, is coated with iridium. At the time of this reporting, no single material has been found that can perform the functions of this combination

  19. Digital image processing versus visual assessment of chewed two-colour wax in mixing ability tests.

    Science.gov (United States)

    van der Bilt, A; Speksnijder, C M; de Liz Pocztaruk, R; Abbink, J H

    2012-01-01

    Two-colour chewing gum and wax have been widely used as test foods to evaluate the ability to mix and knead a food bolus. The mixing of the colours has been assessed by computer analysis or by visual inspection. Reports contradict each other about whether computer analysis and visual assessment could equally well discriminate between the masticatory performances of groups of participants with different dental status. This study compares the results of computer analysis of digital images of chewed two-colour wax with the results of visual assessment of these images. Sixty healthy subjects participated and chewed on red-blue wax for 5, 10, 15 and 20 chewing strokes. The subjects were divided into three groups of 20, matched for age and gender, according to their dental status: natural dentition, full dentures and maxillary denture plus implant-supported mandibular overdenture. Mixing of the chewed wax was determined by computer analysis of images of the wax and by visual assessment of the images by five examiners. Both the computer method and the observers were able to distinguish the mixing abilities of the dentate subjects from the two denture wearer groups. Computer analysis could also discriminate the mixing abilities of the two denture groups. However, observers were not able to distinguish the mixing abilities of the two denture groups after 5, 10 and 15 chewing strokes. Only after 20 chewing strokes, they could detect a significant difference in mixing ability.

  20. Development and evaluation of sustained-release ibuprofen-wax microspheres. II. In vitro dissolution studies.

    Science.gov (United States)

    Adeyeye, C M; Price, J C

    1994-04-01

    A modified USP paddle method using minibaskets was used to study the effects of various formulations on in vitro dissolution of ibuprofen microspheres. Formulations containing waxes such as paraffin or ceresine wax without modifiers exhibited very slow dissolution profiles and incomplete release, which did not improve with increased drug loading or the preparation of smaller microspheres. The addition of modifiers such as stearyl alcohol and glyceryl monostearate greatly increased the dissolution rate, with 20% (w/w) near the optimum for predictable dissolution. Higher drug loading and decreased microsphere size increased the dissolution rate from microspheres containing modifier. Optimum formulations contained ceresine wax or microcrystalline wax and stearyl alcohol as a modifier, with a drug content of 17%. An increase in the encapsulation dispersant concentration had little effect on the dissolution profiles. The dissolution data from narrow size fractions of microspheres indicated spherical matrix drug release kinetics; the 50% dissolution time decreased with the square of the microsphere diameter. With appropriate modifiers, wax microsphere formulations of drugs with solubility characteristics similar to those of ibuprofen can offer a starting basis for predictable sustained release dosage forms.

  1. Mechanical and Hydraulic Properties of Wax-coated Sands for Sport Surfaces

    Science.gov (United States)

    Bardet, J. P.; Benazza, C.; Bruchon, J. F.; Mishra, M.

    2009-06-01

    Natural soils such as sandy loams are being replaced by synthetic soils for various types of sport and recreational surfaces, including horseracing tracks. These synthetic soils are made of a mixture of sand, microcrystalline wax, synthetic fibers and rubber chips which optimize the mechanical and hydraulic properties of natural soils so that they drain faster after rainstorms and decrease risks of sport injuries while retaining appropriate sport performances. Silica sand, which makes up the largest fraction of synthetic soils, is hydrophyllic by nature, i.e., tends to retain water on sand grain surfaces. After rainstorms, hydrophilic surfaces retain a large amount of water, are difficult to compact, and yield uncontrollable mechanical and hydraulic properties when too moist. The addition of wax contributes to improving both mechanical and hydraulic properties of sands. Wax coats the sand grains with a thin layer, and enhances adherence between sand particles. It repels water from sand grains and influences both compaction and hydraulic properties. This study reports experimental results that help to understand the properties of wax-coated sands used in synthetic surfaces, especially the degradation of synthetic surfaces that have insufficient wax-coatings.

  2. Cuticular permeance in relation to wax and cutin development along the growing barley (Hordeum vulgare) leaf.

    Science.gov (United States)

    Richardson, Andrew; Wojciechowski, Tobias; Franke, Rochus; Schreiber, Lukas; Kerstiens, Gerhard; Jarvis, Mike; Fricke, Wieland

    2007-05-01

    The developing leaf three of barley provides an excellent model system for the direct determination of relationships between amounts of waxes and cutin and cuticular permeance. Permeance of the cuticle was assessed via the time-course of uptake of either toluidine blue or (14)C-labelled benzoic acid ([(14)C] BA) along the length of the developing leaf. Toluidine blue uptake only occurred within the region 0-25 mm from the point of leaf insertion (POLI). Resistance--the inverse of permeance--to uptake of [(14)C] BA was determined for four leaf regions and was lowest in the region 10-20 mm above POLI. At 20-30 and 50-60 mm above POLI, it increased by factors of 6 and a further 32, respectively. Above the point of emergence of leaf three from the sheath of leaf two, which was 76-80 mm above POLI, resistance was as high as at 50-60 mm above POLI. GC-FID/MS analyses of wax and cutin showed that: (1) the initial seven fold increase in cuticular resistance coincided with increase in cutin coverage and appearance of waxes; (2) the second, larger and final increase in cuticle resistance was accompanied by an increase in wax coverage, whereas cutin coverage remained unchanged; (3) cutin deposition in barley leaf epidermis occurred in parallel with cell elongation, whereas deposition of significant amounts of wax commenced as cells ceased to elongate.

  3. Use of palmae wax hydrocarbon fractions as chemotaxonomical markers in Butia and Syagrus

    Directory of Open Access Journals (Sweden)

    N. Paroul

    Full Text Available The wax hydrocarbon fractions of native Butia and Syagrus species collected from Palms in different regions of the of Rio Grande do Sul state (Brazil and in Rocha (Uruguay were analyzed to evaluate their potential as chemotaxonomic markers. The wax was extracted with chloroform and the resulting wax was fractionated by preparative TLC. The hydrocarbon fractions were analyzed by GC-MS. Statistical analyses were completed with the Statistica 5.0 program. The total crude wax yields averaged 0.31% w.w-1 dried leaves for Butia samples and 0.28% for Syagrus samples. The linear hydrocarbons represented on average 15% of the total waxes in the case of Butia samples and 13.7% in Syagrus samples. Hentriacontane and triacontane were the main components of all samples. The comparison of the means showed significant differences among Butia and Syagrus samples, and amongst Butia samples collected in different localities. In the case of the Syagrus collections no consistent groupings could be made. In the case of Butia samples the formation of three groupings could be observed, which were consistent with the species described for their geographical distribution. These results are discussed in the paper.

  4. Effect on Mechanical Properties of Hybrid Blended Coconut Coir/Paraffin Wax/LDPE

    Directory of Open Access Journals (Sweden)

    Kannan Rassiah

    2011-12-01

    Full Text Available The use of natural fibers as the fillers for plastic has been rapidly expanding, especially wood fibers. This is due to materials of wood offers many advantages as inorganic fillers (such as low price, biodegradability, renewability, recycle-ability, low density and others. In addition, this is also due to the dramatic increasing of interest of using biomass materials as the replacements for glass fiber into reinforced thermoplastic composites. In this study, wood plastic composites used are the filled thermoplastics which primarily consisted of wood fiber and thermoplastic polymer. While, the purpose of this research is to find out the optimum conditions of the wax and coconut coir produced by inducing LDPE. The experiment carried out is by mixing the wax, coconut coir and LDPE into eight new polymer compositions, in which the higher value of the tensile strength and hardness are obtained by mixing between 6 wt. % coconut coir with 4 wt. % wax, rather than to pure LDPE, that is 9.236 MPa and 3HV. Although the strength impact is decreased with value as much as 60.95 % compared to original conditions, the SEM analysis proved that the composition of 90 wt. % LDPE, 4 wt. % wax and 6 wt. % coconut coir is the best weight ratios for mechanical characteristics and bonding between reinforced material and matrix material. Here, the LDPE, wax and coconut coir mixture produces a new hybrid polymer and alters the properties of pure LDPE.

  5. Biodegradation of paraffin wax by crude Aspergillus enzyme preparations for potential use in removing paraffin deposits.

    Science.gov (United States)

    Zhang, Junhui; Xue, Quanhong; Gao, Hui; Wang, Ping

    2015-11-01

    Paraffin deposition problems have plagued the oil industry. Whist mechanical and chemical methods are problematic, microbiological method of paraffin removal is considered an alternative. However, studies have mainly investigated the use of bacteria, with little attention to the potential of fungi. The performance of six Aspergillus isolates to degrade paraffin wax was evaluated under laboratory conditions using solid enzyme preparations. The results showed that all the six enzyme preparations efficiently improved the solubility of paraffin wax in n-hexane and degraded n-alkanes in paraffin wax. The degradation process was accompanied by dynamic production of gases (CO2 and H2 ) and organic acids (oxalate and propionate). The shape of wax crystals markedly changed after enzymatic degradation, with a rough surface and a loose structure. This study indicates that extracellular enzymes from Aspergillus spp. can efficiently degrade paraffin wax. These enzyme preparations have the potential for use in oil wells with paraffin deposition problems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Major constituents of the foliar epicuticular waxes of species from the Caatinga and Cerrado.

    Science.gov (United States)

    Oliveira, A F; Salatino, A

    2000-01-01

    The epicuticular waxes of leaves of four species (Aspidosperma pyrifolium, Capparis yco, Maytenus rigida and Ziziphus joazeiro) from the Caatinga, (a semi-arid ecosystem of Northeast Brazil) and four species (Aristolochia esperanzae, Didymopanax vinosum, Strychnos pseudoquina and Tocoyena formosa) from the Cerrado, (a savanna ecosystem covering one third of the Brazilian territory), were analyzed. Six species contained a high content (above 60 microg x cm(-2)) of wax, four of them from the Caatinga. Triterpenoids and n-alkanes were the most frequent and abundant constituents found in the species from both habitats. The distribution of n-alkanes predominated by homologues with 27, 29, 31 and 33 carbon atoms, displayed no consistent differences between species from the two habitats. Lupeol, beta-amyrin, epifriedelinol and ursolic acid were the triterpenoids found. Triterpenoids clearly predominate over alkanes in the waxes from the Cerrado species. The waxes of two evergreen species from the Caatinga yielded n-alkanes as predominant constituents. A comparison of foliar epicuticular waxes of native plants from ecosystems with different hydric constraints is discussed.

  7. Quantitative, nondestructive assessment of beech scale (Hemiptera: Cryptococcidae) density using digital image analysis of wax masses.

    Science.gov (United States)

    Teale, Stephen A; Letkowski, Steven; Matusick, George; Stehman, Stephen V; Castello, John D

    2009-08-01

    Beech scale, Cryptococcus fagisuga Lindinger, is a non-native invasive insect associated with beech bark disease. A quantitative method of measuring viable scale density at the levels of the individual tree and localized bark patches was developed. Bark patches (10 cm(2)) were removed at 0, 1, and 2 m above the ground and at the four cardinal directions from 13 trees in northern New York and 12 trees in northern Michigan. Digital photographs of each patch were made, and the wax mass area was measured from two random 1-cm(2) subsamples on each bark patch using image analysis software. Viable scale insects were counted after removing the wax under a dissecting microscope. Separate regression analyses at the whole tree level for the New York and Michigan sites each showed a strong positive relationship of wax mass area with the number of underlying viable scale insects. The relationships for the New York and Michigan data were not significantly different from each other, and when pooling data from the two sites, there was still a significant positive relationship between wax mass area and the number of scale insects. The relationships between viable scale insects and wax mass area were different at the 0-, 1-, and 2-m sampling heights but do not seem to affect the relationship. This method does not disrupt the insect or its interactions with the host tree.

  8. EFFECT OF OIL TEMPERATURE ON THE WAX DEPOSITION OF CRUDE OIL WITH COMPOSITION ANALYSIS

    Directory of Open Access Journals (Sweden)

    Qing Quan

    Full Text Available Abstract Wax deposition behavior was investigated in a set of one-inch experiment flow loops, using a local crude oil with high wax content. The temperature of the oil phase is chosen as a variable parameter while the temperature of the coolant media is maintained constant. Detailed composition of the deposit is characterized using High Temperature Gas Chromatography. It was found that the magnitude of the diffusion of the heavier waxy components (C35-C50 decreases when the oil temperature decreases, but the magnitude of the diffusion of the lighter waxy components increases. This result means that the diffusion of wax molecules shifts towards lower carbon number, which further proves the concept of molecular diffusion. Meanwhile, a meaningful phenomenon is that the mass of the deposit increases with the oil temperature decrease, which definitely proves the influence of wax solubility on deposition, while the formation of an incipient gel layer reflects the fact that an increase in the mass of the deposit does not mean a larger wax percentage fraction at lower oil temperature.

  9. Assessment of wax coatings in postharvest preservation of the pea (Pisum sativum L. var. Santa Isabel

    Directory of Open Access Journals (Sweden)

    Luis Gabriel Padilla T.

    2015-04-01

    Full Text Available The 'Santa Isabel' pea is the most sown regional variety in Colombia. In order to evaluate the postharvest behavior of 'Santa Isabel', an experiment was conducted that subjected fresh podded peas to different edible wax-coating treatments (Taowax verduras, Ceratec, Ceratec wwd (without washing or disinfection, castor oil, and mineral oil and compared them to treatments with the non-edible wax Cerabrix grees or without waxing (control. The peas were stored in a growth chamber for 2 weeks at a temperature of 7±2°C and a relative humidity of 70±8%. The coating of the pods significantly decreased the loss of fresh weight in the six treatments with coatings, as compared to the control (without coatings. The wax coatings that lost less water included Cerabrix grees (7.78% and Taowax verduras (10.65%, as compared to the control (37.79%. The pH of the grains generally decreased during the 14 days of storage; however, after 10 days, the peas coated with Ceratec and Ceratec wwd again increased the pH of the grain. Furthermore, all of the coatings demonstrated a low incidence of pathogens in the pods, with the better results occurring in the non-edible Cerabrix grees and the edible Taowax verduras; the latter wax also had a good aroma, appearance, and color.

  10. Raman spectroscopic evaluation of efficacy of current paraffin wax section dewaxing agents.

    Science.gov (United States)

    Faoláin, Eoghan O; Hunter, Mary B; Byrne, Joe M; Kelehan, Peter; Lambkin, Helen A; Byrne, Hugh J; Lyng, Fiona M

    2005-01-01

    During a spectroscopic study to identify biochemical changes in cervical tissue with the onset of carcinogenesis, residual paraffin wax contributions were observed on almost all dewaxed formalin-fixed paraffin-processed (FFPP) tissue sections examined. Subsequently, the present study was formulated to evaluate the efficacy of current dewaxing agents using Raman spectroscopy. Three cervical FFPP sections were subjected to each of the protocols. Sections were dewaxed using four common dewaxing protocols, namely, xylene, Histoclear, heat-mediated antigen retrieval (HMAR) using xylene and citrate buffer, and Trilogy (combined deparaffinization and unmasking of antigens). The potential for hexane as a dewaxing agent was also evaluated. Sections were dewaxed in multiple dewaxing cycles using xylene, Histoclear, and hexane. Residual paraffin wax contributions remained at 1062 cm(-1), 1296 cm(-1), and 1441 cm(-1). HMAR using xylene and citrate buffer, and HMAR using Trilogy, showed a similar efficacy, resulting in incomplete removal of wax. Hexane was shown to be the most effective dewaxing agent, resulting in almost complete removal of wax. Immunohistochemistry was carried out on dewaxed slides, and those dewaxed with hexane displayed a stronger positivity (approximately 28%). Implications for histopathology and immunohistochemistry are considered, as well as problems that residual wax poses for spectroscopic evaluation of dewaxed FFPP sections with a view to disease diagnosis.

  11. Major evolutionary trends in hydrogen isotope fractionation of vascular plant leaf waxes.

    Directory of Open Access Journals (Sweden)

    Li Gao

    Full Text Available Hydrogen isotopic ratios of terrestrial plant leaf waxes (δD have been widely used for paleoclimate reconstructions. However, underlying controls for the observed large variations in leaf wax δD values in different terrestrial vascular plants are still poorly understood, hampering quantitative paleoclimate interpretation. Here we report plant leaf wax and source water δD values from 102 plant species grown in a common environment (New York Botanic Garden, chosen to represent all the major lineages of terrestrial vascular plants and multiple origins of common plant growth forms. We found that leaf wax hydrogen isotope fractionation relative to plant source water is best explained by membership in particular lineages, rather than by growth forms as previously suggested. Monocots, and in particular one clade of grasses, display consistently greater hydrogen isotopic fractionation than all other vascular plants, whereas lycopods, representing the earlier-diverging vascular plant lineage, display the smallest fractionation. Data from greenhouse experiments and field samples suggest that the changing leaf wax hydrogen isotopic fractionation in different terrestrial vascular plants may be related to different strategies in allocating photosynthetic substrates for metabolic and biosynthetic functions, and potential leaf water isotopic differences.

  12. Effects of Shear Rate and Inhibitors on Wax Deposition of Malaysian Crude Oil

    Directory of Open Access Journals (Sweden)

    N. Ridzuan

    2015-12-01

    Full Text Available Wax deposition can cause a serious problem in crude oil flow assurance, especially in deep water operation due to the long chain of n-paraffin. This paper examines the effects of two factors on the deposition process, which are shear rate and different types of inhibitors. 10 mL of four different types of wax inhibitors (cocamide diethanolamine (C-DEA, diethanolamine (DEA, poly(ethylene-co-vinyl acetate (EVA and poly (maleic anhydride-alt-1-octadecene (MEA were injected into a crude oil vessel where the temperature of cold finger and water bath were set at 5°C and 50°C, respectively. The rotation speed was operated at different ranges between 0 and 600 rpm. From the result, it was found that the amount of total wax deposit decreased when shear rate increased. EVA showed a strong effect to inhibit wax formation with 33.33% reduction of wax deposit at 400 rpm as compared to other inhibitors.

  13. Role of needle surface waxes in dynamic exchange of mono- and sesquiterpenes

    Science.gov (United States)

    Joensuu, Johanna; Altimir, Nuria; Hakola, Hannele; Rostás, Michael; Raivonen, Maarit; Vestenius, Mika; Aaltonen, Hermanni; Riederer, Markus; Bäck, Jaana

    2016-06-01

    Biogenic volatile organic compounds (BVOCs) produced by plants have a major role in atmospheric chemistry. The different physicochemical properties of BVOCs affect their transport within and out of the plant as well as their reactions along the way. Some of these compounds may accumulate in or on the waxy surface layer of conifer needles and participate in chemical reactions on or near the foliage surface. The aim of this work was to determine whether terpenes, a key category of BVOCs produced by trees, can be found on the epicuticles of Scots pine (Pinus sylvestris L.) and, if so, how they compare with the terpenes found in shoot emissions of the same tree. We measured shoot-level emissions of pine seedlings at a remote outdoor location in central Finland and subsequently analysed the needle surface waxes for the same compounds. Both emissions and wax extracts were clearly dominated by monoterpenes, but the proportion of sesquiterpenes was higher in the wax extracts. There were also differences in the terpene spectra of the emissions and the wax extracts. The results, therefore, support the existence of BVOC associated to the epicuticular waxes. We briefly discuss the different pathways for terpenes to reach the needle surfaces and the implications for air chemistry.

  14. Investigation of molten pool oscillation during GMAW-P process based on a 3D model

    Science.gov (United States)

    Wang, L. L.; Lu, F. G.; Cui, H. C.; Tang, X. H.

    2014-11-01

    In order to better reveal the oscillation mechanism of the pulsed gas metal arc welding (GMAW-P) process due to an alternately varied welding current, arc plasma and molten pool oscillation were simulated through a self-consistent three-dimensional model. Based on an experimental analysis of the dynamic variation of the arc plasma and molten pool captured by a high-speed camera, the model was validated by comparison of the measured and predicted results. The calculated results showed that arc pressure was the key factor causing the molten pool to oscillate. The variation in arc size and temperature from peak time to base time resulted in a great difference in the heat input and arc pressure acting on the molten pool. The surface deformation of the molten pool due to the varying degrees of arc pressure induced alternate displacement and backflow in the molten metal. The periodic iteration of deeper and shallower surface deformation, drain and backflow of molten metal caused the molten pool to oscillate at a certain frequency. In this condition, the arc pressure at the peak time is more than six times higher than that at the base time, and the maximum surface depression is 1.4 mm and 0.6 mm, respectively, for peak time and base time.

  15. Conformational selection in the molten globule state of the nuclear coactivator binding domain of CBP

    DEFF Research Database (Denmark)

    Kjærgaard, Magnus; Teilum, Kaare; Poulsen, Flemming M

    2010-01-01

    Native molten globules are the most folded kind of intrinsically disordered proteins. Little is known about the mechanism by which native molten globules bind to their cognate ligands to form fully folded complexes. The nuclear coactivator binding domain (NCBD) of CREB binding protein is particul...

  16. Chlorination and Dissolution Process of CeO2 in Molten Salt

    Institute of Scientific and Technical Information of China (English)

    MENG; Zhao-kai; LIN; Ru-shan; CHEN; Hui; ZHANG; Kai; JIA; Yan-hong; WANG; Chang-shui; SONG; Peng; HE; Hui

    2015-01-01

    Molten salt electrolysis is considered as a promising technology in pyrochemical process in recent years.In the pyrochemical process of oxides fuel,dissolution of the oxides is a significant issue for study.Oxides cannot be reduced,as the solubility is small in molten salt.The chlorination of oxides can improve the solubility

  17. Thermodynamic Stability of LiFeO2 in Molten Carbonate Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    LiFeO2, as one of candidate cathode materials or additive for molten carbonate fuel cell, has been found to be thermodynamically unstable in CO2 atmosphere at 650℃ (the condition of molten carbonate fuel cell) both by computation and experimental confirmation.

  18. Removal of H2S using molten carbonate at high temperature.

    Science.gov (United States)

    Kawase, Makoto; Otaka, Maromu

    2013-12-01

    Gasification is considered to be an effective process for energy conversion from various sources such as coal, biomass, and waste. Cleanup of the hot syngas produced by such a process may improve the thermal efficiency of the overall gasification system. Therefore, the cleanup of hot syngas from biomass gasification using molten carbonate is investigated in bench-scale tests. Molten carbonate acts as an absorbent during desulfurization and dechlorination and as a thermal catalyst for tar cracking. In this study, the performance of molten carbonate for removing H2S was evaluated. The temperature of the molten carbonate was set within the range from 800 to 1000 °C. It is found that the removal of H2S is significantly affected by the concentration of CO2 in the syngas. When only a small percentage of CO2 is present, desulfurization using molten carbonate is inadequate. However, when carbon elements, such as char and tar, are continuously supplied, H2S removal can be maintained at a high level. To confirm the performance of the molten carbonate gas-cleaning system, purified biogas was used as a fuel in power generation tests with a molten carbonate fuel cell (MCFC). The fuel cell is a high-performance sensor for detecting gaseous impurities. When purified gas from a gas-cleaning reactor was continuously supplied to the fuel cell, the cell voltage remained stable. Thus, the molten carbonate gas-cleaning reactor was found to afford good gas-cleaning performance.

  19. Palladium Catalyzed Suzuki Cross-coupling Reaction in Molten Tetra-n-butylammonium Bromide

    Institute of Scientific and Technical Information of China (English)

    ZOU, Yue(邹岳); WANG, Quan-Rui(王全瑞); TAO, Feng-Gang(陶凤岗); DING, Zong-Biao(丁宗彪)

    2004-01-01

    A practical procedure for palladium catalyzed Suzuki cross-coupling reaction of arylboronic acids with aryl halides, including aryl chlorides in molten tetra-n-butylammonium bromide (TBAB) was developed. The reaction exhibits high efficiency and functional group tolerance. The recovery of the catalyst and molten n-Bu4NBr was also investigated.

  20. Topological switching between an alpha-beta parallel protein and a remarkably helical molten globule.

    NARCIS (Netherlands)

    Nabuurs, S.M.; Westphal, A.H.; Toorn, M. aan den; Lindhoud, S.; Mierlo, C.P. van

    2009-01-01

    Partially folded protein species transiently exist during folding of most proteins. Often these species are molten globules, which may be on- or off-pathway to native protein. Molten globules have a substantial amount of secondary structure but lack virtually all the tertiary side-chain packing char