Sample records for waxes

  1. Ear wax


    Browning, George GG


    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.

  2. HL-20 Wax Model (United States)


    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

  3. Crystallization Behavior of Waxes


    Jana, Sarbojeet


    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...

  4. Organogel formation of soybean oil with waxes (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...

  5. 21 CFR 178.3850 - Reinforced wax. (United States)


    ... 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 (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


    Zhang, Kehao


    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. The wax glands and wax secretion of Matsucoccus matsumurae at different development stages. (United States)

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


    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.

  9. Waxes in asphaltenes of crude oils and wax deposits

    Directory of Open Access Journals (Sweden)

    Yulia M. Ganeeva


    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.

  10. Septal splint with wax plates.

    Directory of Open Access Journals (Sweden)

    Nayak D


    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.

  11. Margarine from organogels of plant wax and soybean oil (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...

  12. 21 CFR 178.3710 - Petroleum wax. (United States)


    ... 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...

  13. 21 CFR 582.1978 - Carnauba wax. (United States)


    ... 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...

  14. Structural features of reconstituted wheat wax films. (United States)

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


    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.

  15. 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


    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)

  16. 21 CFR 186.1555 - Japan wax. (United States)


    ... 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...

  17. The WAXS/WFXT Mission

    CERN Document Server

    Chincarini, G L


    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.

  18. 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:


    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

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



    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...

  20. 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


    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.

  1. 21 CFR 872.6890 - Intraoral dental wax. (United States)


    ... 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...

  2. 21 CFR 178.3720 - Petroleum wax, synthetic. (United States)


    ... 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...

  3. 21 CFR 172.888 - Synthetic petroleum wax. (United States)


    ... 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...

  4. Tectonic microplates: laying it down on wax (United States)

    Katz, R. R.; Bodenschatz, E.


    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.

  5. Wax-bonding 3D microfluidic chips

    KAUST Repository

    Gong, Xiuqing


    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.

  6. Coatings and films derived from clay/wax nanocomposites (United States)

    Chaiko, David J.; Leyva, Argentina A.


    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.

  7. Microencapsulation of Flavors in Carnauba Wax

    Directory of Open Access Journals (Sweden)

    Branko Bugarski


    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.

  8. The Thermodielectric Effect in Paraffin Wax (United States)

    Tomas, Martin; Novotny, Pavel


    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.

  9. Wax Point Determinations Using Acoustic Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

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


    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

  10. Morphology and networks of sunflower wax crystals in organogel (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...

  11. 75 FR 38121 - Petroleum Wax Candles From China (United States)


    ... 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...

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

    NARCIS (Netherlands)

    Folstar, P.


    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

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

    NARCIS (Netherlands)

    Folstar, P.


    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

  14. Experimental wax mixtures for dental use. (United States)

    Kotsiomiti, E; McCabe, J F


    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.

  15. 21 CFR 184.1976 - Candelilla wax. (United States)


    ... 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...

  16. Epicuticular waxes and glaucousness of Encephalartos leaves

    NARCIS (Netherlands)

    Osborne, R; Stevens, JF


    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


    NARCIS (Netherlands)



    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


    NARCIS (Netherlands)



    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

  19. Severe complications of a "Brazilian" bikini wax. (United States)

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


    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.

  20. Real-Time monitoring of intracellular wax ester metabolism

    Directory of Open Access Journals (Sweden)

    Karp Matti


    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.

  1. Stability of dental waxes following repeated heatings. (United States)

    Kotsiomiti, E; McCabe, J F


    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.

  2. 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


    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.

  3. Sintering of wax for controlling release from pellets. (United States)

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


    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.

  4. 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


    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.

  5. Dental wax decreases calculus accumulation in small dogs. (United States)

    Smith, Mark M; Smithson, Christopher W


    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.

  6. Natural oils and waxes: studies on stick bases. (United States)

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


    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.

  7. Absorption and distribution of orally administered jojoba wax in mice. (United States)

    Yaron, A; Samoiloff, V; Benzioni, A


    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.

  8. Effect of solvent extraction on Tunisian esparto wax composition

    Directory of Open Access Journals (Sweden)

    Saâd Inès


    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.

  9. Wax Ester Fermentation and Its Application for Biofuel Production. (United States)

    Inui, Hiroshi; Ishikawa, Takahiro; Tamoi, Masahiro


    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

  10. Effect of asphaltenes on crude oil wax crystallization

    DEFF Research Database (Denmark)

    Kriz, Pavel; Andersen, Simon Ivar


    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....

  11. Effect of asphaltenes on crude oil wax crystallization

    DEFF Research Database (Denmark)

    Kriz, Pavel; Andersen, Simon Ivar


    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....

  12. Antioxidant properties of wax from Yugoslavian oakmoss (Evernia prunastri). (United States)

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


    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.

  13. Gluconeogenesis from storage wax in the cotyledons of jojoba seedlings. (United States)

    Moreau, R A; Huang, A H


    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)


    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. (United States)

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


    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


    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 (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


    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. (United States)

    Allison, R T; Lloyd, D


    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 (United States)

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


    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


    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. (United States)

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


    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† (United States)

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


    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. (United States)

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


    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. Detailed characterization of the substrate specificity of mouse wax synthase. (United States)

    Miklaszewska, Magdalena; Kawiński, Adam; Banaś, Antoni


    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.

  6. Plant surface wax affects parasitoid's response to host footprints (United States)

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


    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.

  7. Chemical and physical analyses of wax ester properties

    Directory of Open Access Journals (Sweden)

    Sejal Patel


    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.

  8. 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


    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.

  9. WAX ActiveLibrary: a tool to manage information overload. (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    B. Kozik


    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.

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

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

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

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


    Widjijono Widjijono; Purwanto Agustiono; Dyah Irnawati


    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-...

  15. Effect of the epicuticular waxes of fruits and vegetables on the photodegradation of rotenone. (United States)

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


    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.

  16. Developmental and Genotypic Variation in Leaf Wax Content and Composition, and in Expression of Wax Biosynthetic Genes in Brassica oleracea var. capitata (United States)

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


    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

  17. Cucumis sativus L. WAX2 Plays a Pivotal Role in Wax Biosynthesis, Influencing Pollen Fertility and Plant Biotic and Abiotic Stress Responses. (United States)

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


    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.

  18. The Effects of Stress on Plant Cuticular Waxes

    National Research Council Canada - National Science Library

    Tom Shepherd; D. Wynne Griffiths


    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...

  19. RDX/Polyethylene Wax Compositions as Pressed Explosive, (United States)


    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

  20. 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)


    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.)

  1. Nest wax triggers worker reproduction in the bumblebee Bombus terrestris. (United States)

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


    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.

  2. 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


    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.

  3. Removal of Wax and Stickies from OCC by Flotation

    Energy Technology Data Exchange (ETDEWEB)

    M. R. Doshi; J. Dyer


    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

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

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


    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.

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

    Directory of Open Access Journals (Sweden)

    Małgorzata Grodzińska-Jurczak


    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.

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

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


    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. (United States)

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


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


    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.

  9. 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


    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.

  10. Genetic control of cuticular wax compounds in Eucalyptus globulus. (United States)

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


    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.

  11. Fungal contamination of paraffin wax blocks in a pathology archive. (United States)

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


    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.

  12. Unheimlich. From Wax Figures to the Uncanny Valley

    Directory of Open Access Journals (Sweden)

    Pietro Conte


    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.

  13. Some Thermal and Electrical Properties of Candelilla Wax



    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...

  14. The Behavior of Some Waxes in Composition B (United States)


    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Riekel, C. E-mail:


    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.

  16. Cannabis-induced psychosis associated with high potency "wax dabs". (United States)

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


    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.

  17. Clinically based diagnostic wax-up for optimal esthetics: the diagnostic mock-up. (United States)

    Simon, Harel; Magne, Pascal


    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.

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


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


    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...

  19. Wetting effects of surface treatments on inlay wax-investment combinations. (United States)

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


    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.

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


    G. Budzik


    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...

  1. 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


    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.


    NARCIS (Netherlands)



    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,

  3. 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.

  4. Uncovered secret of a Vasseur-Tramond wax model. (United States)

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


    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.

  5. 75 FR 80843 - Petroleum Wax Candles From China (United States)


    ....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...

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

    Directory of Open Access Journals (Sweden)

    Yuanfeng Pan


    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.

  7. Wax Precipitation Modeled with Many Mixed Solid Phases

    DEFF Research Database (Denmark)

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


    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...

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

    NARCIS (Netherlands)

    Piek, T.


    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.


    NARCIS (Netherlands)



    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,

  10. Increased production of wax esters in transgenic tobacco plants by expression of a fatty acid reductase:wax synthase gene fusion. (United States)

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


    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.

  11. DEWAX-mediated transcriptional repression of cuticular wax biosynthesis in Arabidopsis thaliana. (United States)

    Suh, Mi Chung; Go, Young Sam


    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.

  12. 75 FR 70713 - Petroleum Wax Candles From the People's Republic of China: Final Results of Expedited Third... (United States)


    ... 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...

  13. 76 FR 773 - Petroleum Wax Candles From the People's Republic of China: Continuation of Antidumping Duty Order (United States)


    ... 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...

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

    Directory of Open Access Journals (Sweden)

    Widjijono Widjijono


    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.

  15. 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


    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.

  16. Oil adsorption ability of three-dimensional epicuticular wax coverages in plants (United States)

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


    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.

  17. Oil adsorption ability of three-dimensional epicuticular wax coverages in plants (United States)

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


    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

  18. Adhesion force measurements on the two wax layers of the waxy zone in Nepenthes alata pitchers. (United States)

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


    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.

  19. Determination of serotonin released from coffee wax by liquid chromatography. (United States)

    Kele, M; Ohmacht, R


    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.

  20. Surfactants and Desensitizing Wax Substitutes for TNT-Based Systems. (United States)


    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

  1. Rheological profiling of organogels prepared at critical gelling concentrations of natural waxes in a triacylglycerol solvent. (United States)

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


    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.

  2. Wax layers on Cosmos bipinnatus petals contribute unequally to total petal water resistance. (United States)

    Buschhaus, Christopher; Hager, Dana; Jetter, Reinhard


    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.

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

    Directory of Open Access Journals (Sweden)

    Elena Gorb


    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

  4. Visualization of micromorphology of leaf epicuticular waxes of the rubber tree Ficus elastica by electron microscopy. (United States)

    Kim, Ki Woo


    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.

  5. Leaf waxes in litter and topsoils along a European transect (United States)

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


    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.

  6. Modified paraffin wax for improvement of histological analysis efficiency. (United States)

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


    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.

  7. Wax solidification of drying agents containing tritiated water

    Energy Technology Data Exchange (ETDEWEB)

    Mishikawa, M.; Kido, H.


    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.

  8. Ultrasound assisted manufacturing of paraffin wax nanoemulsions: process optimization. (United States)

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


    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.


    Directory of Open Access Journals (Sweden)

    Snezhkin Yu.


    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.

  10. Effect of selected physical properties of waxes on investments and casting shrinkage. (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    M.A. AlMaadeed


    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.

  12. Wax esters of different compositions produced via engineering of leaf chloroplast metabolism in Nicotiana benthamiana. (United States)

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


    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.

  13. Candle and candle wax containing metathesis and metathesis-like products (United States)

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


    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.

  14. Critical Involvement of Environmental Carbon Dioxide Fixation to Drive Wax Ester Fermentation in Euglena (United States)

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


    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

  15. 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


    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.

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

  17. 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


    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.

  18. Shape-tunable wax microparticle synthesis via microfluidics and droplet impact. (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    Daniela Hegebarth


    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.

  20. 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


    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.

  1. Intracuticular wax fixes and restricts strain in leaf and fruit cuticles. (United States)

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


    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.

  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


    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 (United States)

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


    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 (United States)


    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, 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. (United States)

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


    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. (United States)

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


    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. (United States)

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


    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


    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). (United States)

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


    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. (United States)

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


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

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

    Beermann, Anke; Hülskamp, Martin


    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.

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


    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...

  15. Boiling wax burn in mid-autumn festival in Hong Kong. (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    Thomas M. Attard


    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.

  17. pH-sensitive wax emulsion copolymerization with acrylamide hydrogel using gamma irradiation for dye removal (United States)

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


    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

  18. Production of wax esters in plant seed oils by oleosomal cotargeting of biosynthetic enzymes[S (United States)

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


    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

  19. Simple Synthesis Hydrogenated Castor Oil Fatty Amide Wax and Its Coating Characterization. (United States)

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


    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.

  20. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery (United States)

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


    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

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

  2. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery. (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    J. Zych


    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.

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

    NARCIS (Netherlands)

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


    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

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

    NARCIS (Netherlands)

    Klerk, de Geert Jan; Pramanik, Dewi


    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

  6. Cuticular wax composition of Salix varieties in relation to biomass productivity. (United States)

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


    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.

  7. Fruit cuticular waxes as a source of biologically active triterpenoids. (United States)

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


    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.

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

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


    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

  9. Investigating molecular interactions and surface morphology of wax-doped asphaltenes. (United States)

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


    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

  10. System and method for the mitigation of paraffin wax deposition from crude oil by using ultrasonic waves (United States)

    Towler, Brian F.


    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.

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


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


    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 ...

  12. Composition and morphology of cuticular wax in blueberry (Vaccinium spp.) fruits. (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    K. Grzeskowiak


    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.

  14. 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)


    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)

  15. 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


    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.

  16. Understanding wax screen-printing: a novel patterning process for microfluidic cloth-based analytical devices. (United States)

    Liu, Min; Zhang, Chunsun; Liu, Feifei


    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.

  17. 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


    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.

  18. 76 FR 46277 - Petroleum Wax Candles From the People's Republic of China: Final Results of Request for Comments... (United States)


    ... 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...

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

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


    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.

  20. Transport barriers made of cutin, suberin and associated waxes. (United States)

    Schreiber, Lukas


    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.

  1. 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)


    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.

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

    Directory of Open Access Journals (Sweden)

    Paresh Ramesh Mahaparale


    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.

  3. Development of formulations and processes to incorporate wax oleogels in ice cream. (United States)

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


    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.


    Energy Technology Data Exchange (ETDEWEB)



    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.

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

    Directory of Open Access Journals (Sweden)

    G. Budzik


    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.

  6. Anatomical models and wax Venuses: art masterpieces or scientific craft works? (United States)

    Ballestriero, R


    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.

  7. Micromorphology of epicuticular wax structures of the garden strawberry leaves by electron microscopy: syntopism and polymorphism. (United States)

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


    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.

  8. Thermal behavior of gamma-irradiated low-density polyethylene/paraffin wax blend (United States)

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


    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.

  9. Structural profiling of wax biopolymer from Pinus roxburghii Sarg. needles using spectroscopic methods. (United States)

    Dubey, Pallavi; Sharma, Pradeep; Kumar, Vineet


    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.

  10. Altering small and medium alcohol selectivity in the wax ester synthase. (United States)

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


    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.

  11. Comparative Analyses of Cuticular Waxes on Various Organs of Potato (Solanum tuberosum L.). (United States)

    Guo, Yanjun; Jetter, Reinhard


    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.

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

    Directory of Open Access Journals (Sweden)

    Dawei Xue


    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.

  13. Bioinspired Composite Coating with Extreme Underwater Superoleophobicity and Good Stability for Wax Prevention in the Petroleum Industry. (United States)

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


    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.

  14. 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)


    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.)

  15. Tectonic microplates in a wax model of sea-floor spreading (United States)

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


    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.

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



    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 ...

  17. Caffeine and theobromine in epicuticular wax of Ilex paraguariensis A. St.-Hil. (United States)

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


    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.

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


    Padsalgi Amol; Bidkar Sanjay; Jadhav Vijay; Sheladiya Deepak


    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...

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

    DEFF Research Database (Denmark)

    Skals, Niels; Surlykke, Annemarie


    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...

  20. Purification of a jojoba embryo wax synthase, cloning of its cDNA, and production of high levels of wax in seeds of transgenic arabidopsis. (United States)

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


    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.

  1. 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


    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.

  2. Matrix mini-tablets based on starch/microcrystalline wax mixtures. (United States)

    De Brabander, C; Vervaet, C; Fiermans, L; Remon, J P


    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.

  3. Development and properties of a wax ester hydrolase in the cotyledons of jojoba seedlings. (United States)

    Huang, A H; Moreau, R A; Liu, K D


    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).

  4. 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:; Hoffmann, Rainer [Heroya Research Centre, Statoil ASA (Norway)


    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.

  5. 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: [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)


    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.

  6. An improved index for the waxed stage of an implant-retained framework. (United States)

    Adrian, E D; Krantz, W A; Ivanhoe, J R; Edge, M J


    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.

  7. In search of low cost biological analysis: Wax or acrylic glue bonded paper microfluidic devices

    KAUST Repository

    Kodzius, Rimantas


    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

  8. The structure of integument and wax glands of Phenacoccus fraxinus (Hemiptera: Coccoidea: Pseudococcidae). (United States)

    Zhang, Yanfeng; Xie, Yingping; Xue, Jiaoliang; Fu, Xiaohong; Liu, Weimin


    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.

  9. Comparison of Super Stuff and paraffin wax bolus in radiation therapy of irregular surfaces. (United States)

    Humphries, S M; Boyd, K; Cornish, P; Newman, F D


    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.

  10. 纯棉蜡印布生产工艺%Wax printing of cotton fabric

    Institute of Scientific and Technical Information of China (English)



    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.

  11. Vacuum/compression valving (VCV) using parrafin-wax on a centrifugal microfluidic CD platform. (United States)

    Al-Faqheri, Wisam; Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Moebius, Jacob; Joseph, Karunan; Arof, Hamzah; Madou, Marc


    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.

  12. Physico-chemical properties and efficacy of silk fibroin fabric coated with different waxes as wound dressing. (United States)

    Kanokpanont, Sorada; Damrongsakkul, Siriporn; Ratanavaraporn, Juthamas; Aramwit, Pornanong


    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

  13. Rewiring the wax ester production pathway of Acinetobacter baylyi ADP1. (United States)

    Santala, Suvi; Efimova, Elena; Koskinen, Perttu; Karp, Matti Tapani; Santala, Ville


    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.

  14. RDX-Polyethylene Wax Formulations as Potential Replacements for Tetryl in Fuze Leads, Boosters and Magazines (United States)


    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

  15. Sediment Dynamics in a Vegetated Tidally Influenced Interdistributary Island: Wax Lake, Louisiana (United States)


    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

  16. Plant leaf wax biomarkers capture gradients in hydrogen isotopes of precipitation from the Andes and Amazon (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


    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.

  17. Very long chain alkylresorcinols accumulate in the intracuticular wax of rye (Secale cereale L.) leaves near the tissue surface. (United States)

    Ji, Xiufeng; Jetter, Reinhard


    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.

  18. Characterization of Wax Esters by Electrospray Ionization Tandem Mass Spectrometry: Double Bond Effect and Unusual Product Ions. (United States)

    Chen, Jianzhong; Green, Kari B; Nichols, Kelly K


    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.

  19. Wax beads as cushioning agents during the compression of coated diltiazem pellets. (United States)

    Vergote, G J; Kiekens, F; Vervaet, C; Remon, J P


    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.

  20. The effect of wax on compaction of microcrystalline cellulose beads made by extrusion and spheronization. (United States)

    Iloañusi, N O; Schwartz, J B


    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.

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

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


    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. 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.


    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.

  3. Epicuticular waxes from caatinga and cerrado species and their efficiency against water loss

    Directory of Open Access Journals (Sweden)

    Oliveira Antonio F. M.


    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 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.

  4. Epicuticular waxes from caatinga and cerrado species and their efficiency against water loss. (United States)

    Oliveira, Antonio F M; Meirelles, Sérgio T; Salatino, Antonio


    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 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.

  5. Effect of leaf surface waxes on leaf colonization by Pantoea agglomerans and Clavibacter michiganensis. (United States)

    Marcell, Lise M; Beattie, Gwyn A


    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.


    Directory of Open Access Journals (Sweden)



    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.

  7. Effect of monosodium methanarsonate application on cuticle wax content of cocklebur and cotton plants. (United States)

    Keese, Renee J; Camper, N Dwight


    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.

  8. The use of paraffin wax in a new solar cooker with inner and outer reflectors

    Directory of Open Access Journals (Sweden)

    Arabacigil Bihter


    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.

  9. 超级仿蜡印花%Super imitation wax printing

    Institute of Scientific and Technical Information of China (English)



    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.

  10. Waxes and plastic film in relation to the shelf life of yellow passion fruit

    Directory of Open Access Journals (Sweden)

    Mota Wagner Ferreira da


    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.

  11. Hydrophobic trichome layers and epicuticular wax powders in Bromeliaceae. (United States)

    Pierce, S; Maxwell, K; Griffiths, H; Winter, K


    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.


    Directory of Open Access Journals (Sweden)

    S. M. Iashchenko


    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.

  13. 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


    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.

  14. A novel bifunctional wax ester synthase/acyl-CoA:diacylglycerol acyltransferase mediates wax ester and triacylglycerol biosynthesis in Acinetobacter calcoaceticus ADP1. (United States)

    Kalscheuer, Rainer; Steinbüchel, Alexander


    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.

  15. Wax on, wax off

    DEFF Research Database (Denmark)

    Bos, Nicky Peter Maria; Grinsted, Lena; Holman, Luke


    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...

  16. Bone wax as a cause of a foreign body granuloma in a cranial defect: a case report. (United States)

    Wolvius, E B; van der Wal, K G H


    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.

  17. Production and characterization of vaginal suppositories with propolis wax as active agent to prevent and treat Fluor albus (United States)

    Farida, Siti; Azizah, Nurul; Hermansyah, Heri; Sahlan, Muhamad


    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).

  18. The effect of material properties on growth rates of folding and boudinage: Experiments with wax models (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.

  19. Dental students' preferences and performance in crown design: conventional wax-added versus CAD. (United States)

    Douglas, R Duane; Hopp, Christa D; Augustin, Marcus A


    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.

  20. 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.


    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...


    Institute of Scientific and Technical Information of China (English)


    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.

  2. Molecular Radiocarbon Dating of Tropical Lake Sediments: Insights into the Chronology of Leaf Wax Stable Isotope Records (United States)

    Douglas, P. M.; Pagani, M.; Eglinton, T. I.; Brenner, M.; Curtis, J. H.; Hodell, D. A.


    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

  3. Morphodynamics of a Bifurcation on the Wax Lake Delta, LA (United States)

    Slingerland, R. L.; Best, J.; Parsons, D. R.; Edmonds, D. A.


    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.

  4. 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


    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)

  5. Digital image processing versus visual assessment of chewed two-colour wax in mixing ability tests. (United States)

    van der Bilt, A; Speksnijder, C M; de Liz Pocztaruk, R; Abbink, J H


    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.

  6. Development and evaluation of sustained-release ibuprofen-wax microspheres. II. In vitro dissolution studies. (United States)

    Adeyeye, C M; Price, J C


    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.

  7. Mechanical and Hydraulic Properties of Wax-coated Sands for Sport Surfaces (United States)

    Bardet, J. P.; Benazza, C.; Bruchon, J. F.; Mishra, M.


    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.

  8. Cuticular permeance in relation to wax and cutin development along the growing barley (Hordeum vulgare) leaf. (United States)

    Richardson, Andrew; Wojciechowski, Tobias; Franke, Rochus; Schreiber, Lukas; Kerstiens, Gerhard; Jarvis, Mike; Fricke, Wieland


    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.

  9. 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.

  10. Effect on Mechanical Properties of Hybrid Blended Coconut Coir/Paraffin Wax/LDPE

    Directory of Open Access Journals (Sweden)

    Kannan Rassiah


    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.

  11. Biodegradation of paraffin wax by crude Aspergillus enzyme preparations for potential use in removing paraffin deposits. (United States)

    Zhang, Junhui; Xue, Quanhong; Gao, Hui; Wang, Ping


    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.

  12. Major constituents of the foliar epicuticular waxes of species from the Caatinga and Cerrado. (United States)

    Oliveira, A F; Salatino, A


    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.

  13. Quantitative, nondestructive assessment of beech scale (Hemiptera: Cryptococcidae) density using digital image analysis of wax masses. (United States)

    Teale, Stephen A; Letkowski, Steven; Matusick, George; Stehman, Stephen V; Castello, John D


    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.


    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.

  15. 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.


    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.

  16. Raman spectroscopic evaluation of efficacy of current paraffin wax section dewaxing agents. (United States)

    Faoláin, Eoghan O; Hunter, Mary B; Byrne, Joe M; Kelehan, Peter; Lambkin, Helen A; Byrne, Hugh J; Lyng, Fiona M


    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.

  17. 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


    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.

  18. 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.

  19. Effects of Shear Rate and Inhibitors on Wax Deposition of Malaysian Crude Oil

    Directory of Open Access Journals (Sweden)

    N. Ridzuan


    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.

  20. Role of needle surface waxes in dynamic exchange of mono- and sesquiterpenes (United States)

    Joensuu, Johanna; Altimir, Nuria; Hakola, Hannele; Rostás, Michael; Raivonen, Maarit; Vestenius, Mika; Aaltonen, Hermanni; Riederer, Markus; Bäck, Jaana


    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.

  1. Analysis of the constituents in jojoba wax used as a food additive by LC/MS/MS. (United States)

    Tada, Atsuko; Jin, Zhe-Long; Sugimoto, Naoki; Sato, Kyoko; Yamazaki, Takeshi; Tanamoto, Kenichi


    Jojoba wax is a natural gum base used as a food additive in Japan, and is obtained from jojoba oil with a characteristically high melting point. Although the constituents of jojoba oil have been reported, the quality of jojoba wax used as a food additive has not yet been clarified. In order to evaluate its quality as a food additive and to obtain basic information useful for setting official standards, we investigated the constituents and their concentrations in jojoba wax. LC/MS analysis of the jojoba wax showed six peaks with [M+H]+ ions in the range from m/z 533.6 to 673.7 at intervals of m/z 28. After isolation of the components of the four main peaks by preparative LC/MS, the fatty acid and long chain alcohol moieties of the wax esters were analyzed by methanolysis and hydrolysis, followed by GC/MS. The results indicated that the main constituents in jojoba wax were various kinds of wax esters, namely eicosenyl octadecenoate (C20:1-C18:1) (1), eicosenyl eicosenoate (C20:1-C20:1) (II), docosenyl eicosenoate (C22:1-C20:1) (III), eicosenyl docosenoate (C20:1-C22:1) (IV) and tetracosenyl eiosenoate (C24:1-C20:1) (V). To confirm and quantify the wax esters in jojoba wax directly, LC/MS/MS analysis was performed. The product ions corresponding to the fatty acid moieties of the wax esters were observed, and by using the product ions derived from the protonated molecular ions of wax esters the fatty acid moieties were identified by MRM analysis. The concentrations of the wax esters I, II and III, in jojoba wax were 5.5, 21.4 and 37.8%, respectively. In summary, we clarified the main constituents of jojoba wax and quantified the molecular species of the wax esters without hydrolysis by monitoring their product ions, using a LC/MS/MS system.

  2. Preparation and properties of polystyrene encapsulated paraffin wax as possible phase change material in a polypropylene matrix

    Energy Technology Data Exchange (ETDEWEB)

    Mochane, M.J. [Department of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba (South Africa); Luyt, A.S., E-mail: [Department of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba (South Africa)


    Highlights: Black-Right-Pointing-Pointer Polystyrene microcapsules containing about 30 wt% soft paraffin wax were successfully prepared. Black-Right-Pointing-Pointer The presence of microcapsules in polypropylene influenced the morphology and properties of the matrix. Black-Right-Pointing-Pointer The SEBS modifier had little influence on the interaction between polypropylene and microcapsules. - Abstract: The study deals with the preparation and characterization of polystyrene (PS) capsules containing Fischer-Tropsch paraffin wax (PS:wax) as phase change material (PCM) for thermal energy storage embedded in a polypropylene (PP) matrix. Blends of PP/PS:wax were prepared without and with polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) as a modifier. The influence of PS:wax microcapsules on the morphology, as well as thermal and mechanical properties of the PP was investigated. The scanning electron microscopy (SEM) images of the microencapsulated PCM show that the capsules were grouped in irregular spherical agglomerates of size 16-24 {mu}m. However, after melt-blending with PP smaller, perfectly spherical microcapsules were well dispersed in the PP matrix. There was fairly good interaction between the microcapsules and the matrix, even in the absence of SEBS modification. The FTIR spectrum of the microcapsules is almost exactly the same as that of polystyrene, which indicates that the microcapsules were mostly intact and that the FTIR only detected the polystyrene shell. The amount of wax in the PS:wax microcapsules was determined as 20-30% by weight. An increase in PS:wax content resulted in a decrease in the melting peak temperatures of PP. The thermal stability of the blends decreased with an increase in PS:wax microcapsules content as a consequence of the lower thermal stability of both the wax and PS. There was a drop in storage modulus with increasing PS:wax microcapsules content.

  3. Pattern waxes and inaccuracies in fixed and removable partial denture castings. (United States)

    Diwan, R; Talic, Y; Omar, N; Sadig, W


    It is the desire of every dentist and dental technician to produce a restoration that will fit the patient with a minimum of adjustments and certainly one that does not require remaking. Yet many abuse the materials with which they work, either through improper manipulation, lack of familiarity with their properties, or by attempting to reduce laboratory time by taking short cuts. Wax is one of the materials that requires more knowledge and skill to manipulate accurately because it has a considerably higher coefficient of thermal expansion (and contraction) than any other dental material. It often contributes considerably to the inaccuracies of cast dental restorations. This article provides a review of dental waxes used to make prosthodontic castings and points out some of the properties of waxes that must be controlled to make accurate restorations.

  4. Crystallization behavior of anhydrous milk fat-sunflower oil wax blends. (United States)

    Kerr, Rebekah M; Tombokan, Xenia; Ghosh, Supriyo; Martini, Silvana


    This research evaluates the effect of sunflower oil wax (SFOw) addition on the crystallization behavior and functional properties of anhydrous milk fat (AMF). Induction times of nucleation, melting behavior, microstructure of crystals, and hardness were evaluated for samples of pure AMF and AMF with 0.1 and 0.25% SFOw. Results from this research show that the addition of waxes induced the onset of crystallization of AMF by inducing its nucleation, as evidenced by decreased induction times of nucleation and the formation of smaller crystals. Crystal growth after tempering was also promoted by waxes, and significantly harder lipid networks were obtained. Results presented in this paper suggest that SFOw can be used as an additive to alter the physiochemical properties of low trans-fatty acid lipids.

  5. Procedures for extraction and purification of leaf wax biomarkers from peats

    Directory of Open Access Journals (Sweden)

    J.E. Nichols


    Full Text Available Palaeoecological and palaeoclimate reconstruction, using leaf wax biomarkers, is a relatively new sub-discipline of peatland science. The ability to process large numbers of samples rapidly for biomarkers makes this type of analysis particularly appealing. This review is a guide to the preparation of leaf waxes for analysis by gas chromatography. The main phases of preparation are extraction of soluble organic compounds from sediment, separation of the total extract into fractions of differing polarity, and the derivatisation of polar functional groups. The procedures described here are not meant be exhaustive of all organic geochemical possibilities in peatlands, but a distillation of methods for the preparation of leaf waxes that are commonly and increasingly being used in palaeoecological and palaeoclimatological studies.

  6. 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


    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...

  7. Retained bone wax on CT at one year after dacryocystorhinostomy: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Hyun; Park, Dong Woo; Jeong, Jin Yeok [Guri Hospital, Hanyang University College of Medicine, Guri (Korea, Republic of); Lee, Jong Ah; Lee, Young Jun [Dept. of Radiology, Seoul Hospital, Hanyang University College of Medicine, Seoul (Korea, Republic of)


    A 71-year-old man with chronic rhinosinusitis presented with a purulent, foul-smelling nasal discharge and obstruction. One year earlier he had been treated with a dacryocystorhinostomy for nasolacrimal duct obstruction. During the procedure, bone wax had been used to control bleeding in the anterior upper nasal cavity. On computed tomographic imaging, a fat-density lesion was seen in the anterior upper sinonasal cavity and was found to be hypointense or signal-void on all magnetic resonance imaging sequences. The lesion, which proved to consist of bone wax, was surgically removed. Here, we present the imaging features of retained bone wax in a patient with clinically diagnosed chronic rhinosinusitis after dacryocystorhinostomy.

  8. Solution X-ray scattering (S/WAXS) and structure formation in protein dynamics

    CERN Document Server

    Nasedkin, Alexandr; Niemi, Antti J; Peng, Xubiao


    We propose to develop mean field theory in combination with Glauber algorithm, to model and interpret protein dynamics and structure formation in small to wide angle x-ray scattering (S/WAXS) experiments. We develop the methodology by analysing the Engrailed homeodomain protein as an example. We demonstrate how to interpret S/WAXS data with a good precision and over an extended temperature range. We explain experimentally observed phenomena in terms of protein phase structure, and we make predictions for future experiments how the scattering data behaves at different ambient temperature values. We conclude that a combination of mean field theory with Glauber algorithm has the potential to develop into a highly accurate, computationally effective and predictive tool for analysing S/WAXS data. Finally, we compare our results with those obtained previously in an all-atom molecular dynamics simulation.

  9. Wax-up and mock-up. A guide for anterior periodontal and restorative treatments. (United States)

    Gurrea, Jon; Bruguera, August


    When starting a case, having the end result in mind is the basis in any kind of treatment, even more so in those where the anterior teeth morphology, size and proportion will be changed. Here is where a good treatment plan based on a diagnostic wax-up that is tried in with a mock-up and approved by the patient becomes crucial. This case report exemplifies how transferring the information from the diagnostic wax up to the patient's mouth is of help not only to the restorative dentist and the laboratory technician, but also to the surgeon when performing the crown lengthening. This treatment plan cannot be seen as a sequence of isolated procedures but as a single workflow. The wax-up/mock-up binomial is a guide even for the periodontist in a novel approach to surgical crown lengthening.

  10. Printed wax masks for 254 nm deep-UV pattering of PMMA-based microfluidics

    KAUST Repository

    Fan, Yiqiang


    This paper reports a new technique for masking deep-UV exposure of poly(methyl methacrylate) (PMMA) using a printed wax mask. This technique provides an inexpensive and bulk fabrication method for PMMA structures. The technique involves the direct printing of the mask onto a polymer sheet using a commercial wax printer. The wax layer was then transferred to a PMMA substrate using a thermal laminator, exposed using deep-UV (with a wavelength of 254 nm), developed in an IPA:water solution, and completed by bonding on a PMMA cap layer. A sample microfluidic device fabricated with this method is also presented, with the microchannel as narrow as 50 μm. The whole process is easy to perform without the requirement for any microfabrication facilities. © 2012 IOP Publishing Ltd.

  11. Advance in application of emulsified wax%乳化蜡的应用进展

    Institute of Scientific and Technical Information of China (English)



    介绍了乳化蜡的生产应用现状。综述了乳化蜡在农业、汽车工业、造纸工业、纺织工业、皮革工业以及人造板工业等各领域的应用研究进展,展望了乳化蜡的发展前景。%The production and application situation of emulsified wax was introduced. The progress in the research and application of emulsified wax in agriculture, automotive industry, papermaking industry, textile industry, leather industry, wood-based panel industry, etc. , were summarized. The future application and development prospect of the emulsified wax were proposed.

  12. 'Wax bloom' on beeswax cultural heritage objects: Exploring the causes of the phenomenon. (United States)

    Bartl, B; Kobera, L; Drábková, K; Ďurovič, M; Brus, J


    The term 'wax bloom' is used to describe a thin whitish crystalline layer that develops on the surface of beeswax objects under specific conditions. This phenomenon is undesirable, especially in the cases of objects with aesthetic or informational value, such as wax sculptures or historical seals. A combination of solid-state NMR and FTIR measurements allowed to obtain fairly detailed insight into the problem and to suggest a probable mechanism of its development. Secondary crystallization of unsaturated hydrocarbons from beeswax was determined as a primary cause. After the macroscopic solidification of beeswax from the melt, these molecules remain for months in a highly mobile, liquid-like state. This facilitates their diffusion to the surface, where they eventually crystallize, forming the 'wax bloom' effect. Although these results are of particular interest with respect to the conservation of beeswax artifacts, they are relevant to this material in general and help with understanding its unique properties.

  13. Development of lamellar structures in natural waxes - an electron diffraction investigation

    Energy Technology Data Exchange (ETDEWEB)

    Dorset, Douglas L. [Electron Diffraction Department, Hauptman-Woodward Medical Research Institute, Inc., Buffalo, NY (United States)


    When they are recrystallized from the melt, natural plant or insect waxes tend to form solid phases with a nematic-like structure (i.e. a parallel array of polymethylene chains with little or no aggregation of the molecules into distinct layers). An electron diffraction study of carnauba wax and two types of beeswax has shown that the degree of molecular organization into lamellar structures can be enhanced by annealing in the presence of benzoic acid, which also acts as an epitaxial substrate. Nevertheless, the resultant layer structure in the annealed solid is not the same as that found for paraffin wax fractions refined from petroleum. Probably because of a small but significant fraction of a very long chain ingredient, the lamellar separation is incomplete, incorporating a number of 'bridging molecules' that span the nascent lamellar interface.The same phenomenon has been described recently for a low molecular weight polyethylene. (author)

  14. Evaluation of canola oil oleogels with candelilla wax as an alternative to shortening in baked goods. (United States)

    Jang, Areum; Bae, Woosung; Hwang, Hong-Sik; Lee, Hyeon Gyu; Lee, Suyong


    The oleogels of canola oil with candelilla wax were prepared and utilized as a shortening replacer to produce cookies with a high level of unsaturated fatty acids. The incorporation of candelilla wax (3% and 6% by weight) to canola oil produced the oleogels with solid-like properties. The firmness of the oleogels was lower than that of the shortening at room temperature. A more rapid change in the viscosity with temperature was observed with increasing levels of candelilla wax in the steady shear measurements. The replacement of shortening with oleogels in the cookie formulation reduced both viscoelastic parameters (G' and G") of the cookie doughs. The level of unsaturated fatty acids in the oleogel cookies was distinctly increased up to around 92%, compared to the shortening cookies (47.2%). The cookies with the oleogels showed desirable spreadable property and the replacement of shortening with the oleogels produced cookies with soft eating characteristics.

  15. The analysis of the wax foundry models fabrication process for the CPX3000 device

    Directory of Open Access Journals (Sweden)

    G. Budzik


    Full Text Available The paper presents possibilities of creating wax founding models by means of CPX3000 device. The device is used for Rapid Prototypingof models made of foundry wax in an incremental process. The paper also presents problems connected with choosing technologicalparameters for incremental shaping which influence the accuracy of created models. Issues connected with post-processing are alsodescribed. This process is of great importance for obtaining geometrically correct models. The analysis of parameters of cleaning models from supporting material is also presented. At present CPX3000 printer is the first used in Poland device by 3D Systems firm for creating wax models. The printer is at The Faculty of Mechanical Engineering at Rzeszów University of Technology.

  16. Thermal characterizations of the paraffin wax/low density polyethylene blends as a solid fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soojong; Moon, Heejang; Kim, Jinkon, E-mail:


    Highlights: • Regression rate of blends fuel is higher than polymer fuel. • LDPE is an effective mixing ingredient for the combustion efficiency. • Blends fuel is a uniform mixture with two degradation steps. • LDPE plays a positive role for the low sensitivity to the thermal deformation • Blends with low LDPE content can be an effective fuel for hybrid rocket application. - Abstract: Thermal characterizations of a novel solid fuel for hybrid rocket application, based on the paraffin wax blends with low density polyethylene (LDPE) concentration of 5% (SF-5) and 10% (SF-10) were conducted. Both the increased regression rate in comparison with the polymeric fuel, and the improved combustion efficiency in comparison with the pure paraffin fuel reveal that the blend fuels achieve higher combustion performance. The morphology of the shape stabilized paraffin wax/LDPE blends was characterized by the scanning electron microscopy (SEM). Although the SEM observation indicated the blends have uniform mixtures, they showed two degradation steps confirming the immiscibility of components in the crystalline phase from thermogravimetric analysis (TGA). The differential scanning calorimeter (DSC) results showed that the melting temperature of LDPE in the blends decreased with an increase of paraffin wax content. The decreasing total specific melting enthalpy of blended fuels with decreasing paraffin wax content is in fairly good agreement with the additive rule. In thermomechanical analysis (TMA), the linear coefficient of thermal expansion (LCTE) seems to decrease with an increase of LDPE loading, however, the loaded LDPE do merely affect the LCTE in case of the blends with low LDPE concentration. It was found that a blend of low concentration of LDPE with a relatively high concentration of paraffin wax can lead to a potential novel fuel for rocket application, a contrary case with respect to the field of phase change materials (PCM) where a blend of high concentration

  17. Co-metabolism of DDT by the newly isolated bacterium, Pseudoxanthomonas sp. wax

    Directory of Open Access Journals (Sweden)

    Guangli Wang


    Full Text Available Microbial degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenylethane (DDT is the most promising way to clean up DDT residues found in the environment. In this paper, a bacterium designated as wax, which was capable of co-metabolizing DDT with other carbon sources, was isolated from a long-term DDT-contaminated soil sample by an enrichment culture technique. The new isolate was identified as a member of the Pseudoxanthomonas sp., based on its morphological, physiological and biochemical properties, as well as by 16S rRNA gene analysis. In the presence of 100 mg l-1 glucose, the wax strain could degrade over 95% of the total DDT, at a concentration of 20 mg l-1, in 72 hours, and could degrade over 60% of the total DDT, at a concentration of 100 mg l-1, in 144 hours. The wax strain had the highest degradation efficiency among all of the documented DDT-degrading bacteria. The wax strain could efficiently degrade DDT at temperatures ranging from 20 to 37ºC, and with initial pH values ranging from 7 to 9. The bacterium could also simultaneously co-metabolize 1,1-dichloro-2,2-bis(p-chlorophenylethane (DDD, 2,2-bis(p-chlorophenyl-1,1-dichlorethylene (DDE, and other organochlorine compounds. The wax strain could also completely remove 20 mg kg-1 of DDT from both sterile and non-sterile soils in 20 days. This study demonstrates the significant potential use of Pseudoxanthomonas sp. wax for the bioremediation of DDT in the environment.

  18. The deformation of wax patterns and castings in investment casting technology

    Directory of Open Access Journals (Sweden)

    A. Herman


    Full Text Available The dimensional accuracy of the final casting of Inconel alloy 738 LC is affected by many aspects. One of them is the choice of method and time of cooling wax model for precision investment casting. The main objective was to study the initial deformation of the complex shape of the casting of the rotor blades. Various approaches have been tested for cooling wax pattern. When wax models are cooling on the air, without clamping in jig for cooling, deviations from the ideal shape of the casting are very noticeable (up to 8 mm and most are in extreme positions of the model. When blade is cooled in fixing jig in water environment, the resulting deviations compared with cooling in air are significantly larger, sometimes up to 10 mm. This itself does not mean that the final shape of the casting is dimensionally more accurate with usage of wax models, which have deviations from the ideal position smaller. Another deformation occurs when shell mould is produced around wax pattern and furthermore deformations emerge while casting of blade is cooling. This paper demonstrates first steps in describing complex process of deformations of Inconel alloy blades produced with investment casting technology by comparing results from thermal imagery, simulations in foundry simulation software ProCAST 2010 and measurements from CNC scanning system Carl Zeiss MC 850. Conclusions are so far not groundbreaking, but it seems deformations of wax pattern and deformations of castings do in some cases cancel each other by having opposite directions. Describing entirely whole process of deformations will help increase precision of blade castings so that models at the beginning and blades in the end are the same.

  19. Review of data on the dermal penetration of mineral oils and waxes used in cosmetic applications. (United States)

    Petry, T; Bury, D; Fautz, R; Hauser, M; Huber, B; Markowetz, A; Mishra, S; Rettinger, K; Schuh, W; Teichert, T


    Mineral oils and waxes used in cosmetic products, also referred to as "personal care products" outside the European Union, are mixtures of predominantly saturated hydrocarbons consisting of straight-chain, branched and ring structures with carbon chain lengths greater than C16. They are used in skin and lip care cosmetic products due to their excellent skin tolerance as well as their high protecting and cleansing performance and broad viscosity options. Recently, concerns have been raised regarding potential adverse health effects of mineral oils and waxes from dermal application of cosmetics. In order to be able to assess the risk for the consumer the dermal penetration potential of these ingredients has to be evaluated. The scope and objective of this review are to identify and summarize publicly available literature on the dermal penetration of mineral oils and waxes as used in cosmetic products. For this purpose, a comprehensive literature search was conducted. A total of 13 in vivo (human, animal) and in vitro studies investigating the dermal penetration of mineral oils and waxes has been identified and analysed. The majority of the substances were dermally adsorbed to the stratum corneum and only a minor fraction reached deeper skin layers. Overall, there is no evidence from the various studies that mineral oils and waxes are percutaneously absorbed and become systemically available. Thus, given the absence of dermal uptake, mineral oils and waxes as used in cosmetic products do not present a risk to the health of the consumer. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Molecular analysis of intact preen waxes of Calidris canutus (Aves : Scolopacidae) by gas chromatography/mass spectrometry

    NARCIS (Netherlands)

    Dekker, MHA; Piersma, T; Damste, JSS; Dekker, Marlèn H.A.; Sinninghe Damsté, Jaap S.


    The intact preen wax esters of the red knot Calidris canutus were studied with gas chromatography/mass spectrometry (GC/MS) and GC/MS/MS. In this latter technique, transitions from the molecular ion to fragment ions representing the fatty acid moiety of the wax esters were measured, providing additi

  1. OsWS1 involved in cuticular wax biosynthesis is regulated by osa-miR1848. (United States)

    Xia, Kuaifei; Ou, Xiaojin; Gao, Chunzhi; Tang, Huadan; Jia, Yongxia; Deng, Rufang; Xu, Xinlan; Zhang, Mingyong


    Cuticular wax forms a hydrophobic layer covering aerial plant organs and acting as a protective barrier against biotic and abiotic stresses. Compared with well-known wax biosynthetic pathway, molecular regulation of wax biosynthesis is less known. Here, we show that rice OsWS1, a member of the membrane-bound O-acyl transferase gene family, involved in wax biosynthesis and was regulated by an osa-miR1848. OsWS1-tagged green fluorescent protein localized to the endoplasmic reticulum (ER). Compared with wild-type rice, OsWS1 overexpression plants displayed a 3% increase in total wax, especially a 35% increase in very long-chain fatty acids, denser wax papillae around the stoma, more cuticular wax crystals formed on leaf and stem surfaces, pollen coats were thicker and more seedlings survived after water-deficit treatment. In contrast, OsWS1-RNAi and osa-miR1848 overexpression plants exhibited opposing changes. Gene expression analysis showed that overexpression of osa-miR1848 down-regulated OsWS1 transcripts; furthermore, expression profiles of OsWS1 and osa-miR1848 were inversely correlated in the leaf, panicle and stem, and upon water-deficit treatment. These results suggest that OsWS1 is regulated by osa-miR1848 and participates in cuticular wax formation.

  2. Molecular analysis of intact preen waxes of Calidris Canutus (Aves: Scolopacidae) by GC/MS and GC/MS/MS

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Dekker, M.H.A.; Piersma, T.


    The intact preen wax esters of the red knot Calidris canutus were studied with gas chromatography/mass spectrometry (GC/MS) and GC/MS/MS. In this latter technique, transitions from the molecular ion to fragment ions representing the fatty acid moiety of the wax esters were measured, providing additi

  3. Molecular characterization of the CER1 gene of Arabidopsis involved in epicuticular wax biosynthesis and pollen fertility.

    NARCIS (Netherlands)

    Aarts, M.G.M.; Keijzer, C.J.; Stiekema, W.J.; Pereira, A.


    The aerial parts of plants are coated with an epicuticular wax layer, which is important as a first line of defense against external influences. In Arabidopsis, the ECERIFERUM (CER) genes effect different steps of the wax biosynthesis pathway. In this article, we describe the isolation of the CER1 g

  4. Modeling of the fast organic emissions from a wood-finishing product—Floor wax (United States)

    Chang, John C. S.; Guo, Zhishi

    Environmental chamber and full-scale residential house tests were conducted to evaluate the fast organic emissions from a wood-finishing product—floor wax. For the environmental chamber tests, a very small amount of (wax was applied to an aluminum plate. It was found that the chamber exit organic concentrations can be estimated by a model with an initial condition of instant organic emissions. The model was applied to the house data to interpret the octane and nonane emissions. Significant sink effects were found in the house that prolonged the elevated octane and nonane concentrations for more than 2 days.

  5. Cuticular wax accumulation is associated with drought tolerance in wheat near-isogenic lines

    Directory of Open Access Journals (Sweden)

    Jianmin Song


    Full Text Available Previous studies have shown that wheat grain yield is seriously affected by drought stress, and leaf cuticular wax is reportedly associated with drought tolerance. However, most studies have focused on cuticular wax biosynthesis and model species. The effects of cuticular wax on wheat drought tolerance have rarely been studied. The aims of the current study were to study the effects of leaf cuticular wax on wheat grain yield under drought stress using the above-mentioned wheat NILs and to discuss the possible physiological mechanism of cuticular wax on high grain yield under drought stress. Compared to water-irrigated (WI conditions, the cuticular wax content (CWC in glaucous and non-glaucous NILs under drought-stress (DS conditions both increased; mean increase values were 151.1% and 114.4%, respectively, which was corroborated by scanning electronic microscopy images of large wax particles loaded on the surfaces of flag leaves. The average yield of glaucous NILs was higher than that of non-glaucous NILs under DS conditions in 2014 and 2015; mean values were 7368.37 kg·ha-1 and 7103.51 kg·ha-1. This suggested that glaucous NILs were more drought-tolerant than non-glaucous NILs (P = 0.05, which was supported by the findings of drought tolerance indices TOL and SSI in both years, the relatively high water potential and relative water content, and the low ELWL. Furthermore, the photosynthesis rate (Pn of glaucous and non-glaucous wheat NILs under DS conditions decreased by 7.5% and 9.8%, respectively; however, glaucous NILs still had higher mean values of Pn than those of non-glaucous NILs, which perhaps resulted in the higher yield of glaucous NILs. This could be explained by the fact that glaucous NILs had a smaller Fv/Fm reduction, a smaller PI reduction and a greater ABS/RC increase than non-glaucous NILs under DS conditions. This is the first report to show that wheat cuticular wax accumulation is associated with drought tolerance. Moreover

  6. In search of low cost biological analysis: Wax or acrylic glue bonded paper microfluidic devices

    KAUST Repository

    Kodzius, Rimantas


    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 or acrylic glue, and characterized the affect of these and other microfluidic materials on the polymerase chain reaction (PCR). 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 or cyanoacrylate-based resin 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 or simple cyanoacrylate-based resin can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate film, glass sheets, or metal plate. The wax 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 evacuating the channels of adhesive material in a hot-water. We applied the wax-paper based microfluidic chip to HeLa cell electroporation. 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 recombinant 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. The chip bonded with cyanoacrylate-based resin was tested by measuring protein concentration and carrying out DNA capillary electrophoresis. To study the biocompatibility and applicability of our microfluidic chip fabrication technology, we tested the PCR compatibility of our chip materials along with various other common materials

  7. Release kinetics of salbutamol sulphate from wax coated microcapsules and tableted microcapsules. (United States)

    Raghuvanshi, R S; Tripathi, K P; Jayaswal, S B; Singh, J


    Microcapsules of salbutamol sulphate were prepared using beeswax and carnauba wax as coating materials. In vitro release kinetics were studied following the zero order, first order and Higuchi equations. Beeswax alone was not effective but beeswax and carnauba wax combinations were suitable in controlling the in vitro release of the drug. Microcapsules were compressed into tablets to get a controlled release oral dosage form. Release from tableted microcapsules was significantly more prolonged than the respective batches of the microcapsules. Best data fit with the highest correlation coefficient for the tableted microcapsules was obtained for first order.

  8. Chamber for in situ WAXS, SAXS and GISAXS studies: application to plasma induced transformations in steels

    CERN Document Server

    Kellermann, G; Feugeas, J; Craievich, A F


    A chamber for in situ WAXS, SAXS and GISAXS studies of polycrystalline and amorphous materials was designed and constructed. It is used under vacuum or filled with a gas mixture to operate as a reactor where a plasma for materials surface treatment is produced. The WAXS intensity is recorded by an external imaging plate moving parallel to the chamber axis, making it possible to obtain successive patterns during in situ studies of structural transformations. The chamber is also used for classical SAXS and GISAXS studies of thin films.

  9. Bees wax and its unsaponifiables as natural preservative for butter and cottonseed oils

    Directory of Open Access Journals (Sweden)

    Farag, R. S.


    Full Text Available Simple model systems consisting of butter oil or refined cottonseed oil mixed with melted bees wax and its unsaponifiables were designated to study their hydrolytic and oxidative rancidity during storage. Whole bees wax at 0,5 and 1% levels possessed significant pro-hydrolytic activity whilst its unsaponifiables at 0,25 and 0,5% exhibited antihydrolytic effect on butter oil. The addition of whole bees wax at 0,5 and 1 % caused no effect on peroxide and thiobarbituric acid values of butter oil. However, bees wax unsaponifiables significantly reduced both peroxide and thiobarbituric acid values of stored butter oil. Bees wax unsaponifiables added to refined cottonseed oil had no effect on the acid value, whilst whole bees wax possessed significant prohydrolytic activity. The data for peroxide and thiobarbituric acid values of refined cottonseed oil demonstrated that both whole bees wax and its unsaponifiables had approximately the same antioxidant efficacy. The effectiveness of the added materials on the secondary oxidation products of refined cottonseed oil can be ranked according to its inhibition activity as follows: BHT (200 ppm > bees wax (1% > bees wax (0,5% > bees wax unsaponifiables (0,5% > bees wax unsaponifiables (0,25% > control.

    aceites de semilla de algodón Sistemas modelo simples consistentes en aceite de mantequilla o aceite de semilla de algodón refinado mezclado con cera de abeja derretida y su insaponificable fueron diseñados para estudiar su rancidez oxidativa e hidrolítica durante el almacenamiento. La cera de abeja íntegra a niveles del 0,5 y 1% tuvo una actividad pro-hidrolítica significativa, mientras que su insaponificable al 0,25 y 0,5% exhibió efecto antihidrolítico sobre el aceite de mantequilla. La adición de cera de abeja íntegra al 0,5 y 1% no causó efecto sobre el índice de peróxido y ácido tiobarbitúrico del aceite de mantequilla. Sin embargo, el insaponificable de cera de abeja redujo

  10. Analysis of cuticular wax constituents and genes that contribute to the formation of 'glossy Newhall', a spontaneous bud mutant from the wild-type 'Newhall' navel orange. (United States)

    Liu, Dechun; Yang, Li; Zheng, Qiong; Wang, Yuechen; Wang, Minli; Zhuang, Xia; Wu, Qi; Liu, Chuanfu; Liu, Shanbei; Liu, Yong


    Navel orange (Citrus sinensis [L.] Osbeck) fruit surfaces contain substantial quantities of cuticular waxes, which have important eco-physiological roles, such as water retention and pathogen defense. The wax constituents of ripe navel orange have been studied in various reports, while the wax changes occurring during fruit development and the molecular mechanism underlying their biosynthesis/export have not been investigated. Recently, we reported a spontaneous bud mutant from the wild-type (WT) 'Newhall' Navel orange. This mutant displayed unusual glossy fruit peels and was named 'glossy Newhall' (MT). In this study, we compared the developmental profiles of the epicuticular and intracuticular waxes on the WT and MT fruit surfaces. The formation of epicuticular wax crystals on the navel orange surface was shown to be dependent on the accumulation of high amounts of aliphatic wax components with trace amounts of terpenoids. In sharp contrast, the underlying intracuticular wax layers have relatively low concentrations of aliphatic wax components but high concentrations of cyclic wax compounds, especially terpenoids at the late fruit developmental stages. Our work also showed that many genes that are involved in wax biosynthesis and export pathways were down-regulated in MT fruit peels, leading to a decrease in aliphatic wax component amounts and the loss of epicuticular wax crystals, ultimately causing the glossy phenotype of MT fruits.

  11. Synthesis and Properties of a Lacquer Wax-Based Quarternary Ammonium Gemini Surfactant

    Directory of Open Access Journals (Sweden)

    Hongxia Chen


    Full Text Available Lacquer wax is an important fatty resource obtained from the mesocarp of the berries of Toxicodendron vernicifluum. In order to expand the applications of lacquer wax, we hydrolyzed it after establishing the best conditions for the acid-catalyzed hydrolysis using a Box-Behnken design. Then we synthesized a quarternary ammonium gemini surfactant by a three-step reaction. The surface properties of an aqueous solution of the final product were investigated. The optimum conditions were 9% catalyst, 100 °C of reaction temperature and 14 h of reaction time, while the maximum free fatty acids (FFA% was 99.67%. From the gas chromatography, the main fatty acids of the lacquer wax were palmitic, oleic and octadecanoic acid. The lacquer wax gemini surfactant was synthesized, and its structure was confirmed by IR and NMR. The experiments showed that the critical micelle concentration (CMC is 5 × 10−4 mol·L−1, the surface tension is 33.6 mN·m−1. When the content of surfactant was 0.1%, the separation time of 5 mL water was 10 min.

  12. Mutagenic activity of sweepings and pigments from a household-wax factory assayed with Salmonella typhimurium. (United States)

    Varella, S D; Pozetti, G L; Vilegas, W; Varanda, E A


    The mutagenic activity of garbage originating from a household wax industry was determined by the Salmonella/microsome assay, using the bacterial strains TA100, TA98 and YG1024. The garbage was obtained by sweeping the floor of the factory at the end of the work shift. Organic compounds were extracted by ultrasound for 30 min in dichloromethane or 70% ethanol. After evaporation of solvent, these extracts (HFS: household-wax factory sweepings) were dissolved in DMSO, and were tested for the mutagenic activity at varying concentrations (HFS-ET: 0.08-0.68 mg/plate, HFS-DCM: 0.60-7.31 mg/plate). The colouring agents (pigments) used in the production of the wax were also dissolved in DMSO and tested with the assay. The concentrations tested for each pigment were: Amaranth: 0.46-3.65 mg/plate, Auramine: 0.15-1.2 mg/plate and Rhodamine B: 0.22-1.82 mg/plate. Both ET and DCM organic extracts had mutagenic activity, especially in the YG1024 strain. The pigments behaved in a similar way, demonstrating that YG1024 was the most sensitive strain for the detection of mutagenicity, and that metabolization increased the activity. Human exposure (occupational and non-occupational) to industrial residues generated during the household-wax manufacturing and packaging process should be monitored, since this type of garbage is normally deposited in the environment without any control.

  13. Effect of Zeolite Treatment on the Blooming Behavior of Paraffin Wax in Natural Rubber Composites

    Directory of Open Access Journals (Sweden)

    Bryan B. Pajarito


    Full Text Available The blooming behavior of paraffin wax in natural rubber (NR composites was studied as function of zeolite treatment. Three types of zeolite treatment were treated as factors: acid activation using hydrochloric acid (HCl solution, ion exchange using tetradecyldimethyl amine (TDA chloride salt, and organic modification using glycerol monostearate (GMS. The zeolite was treated according to a 23 full factorial design of experiment. Attenuated total reflectance – Fourier transform infrared (ATR-FTIR spectroscopy was used to characterize the chemical structure of treated zeolite. Treated zeolite was applied as filler to NR composites deliberately compounded with high amount of paraff in wax. The amount of bloomed wax in surface of NR composite sheets was monitored with time at 50oC. Results show the bloom amount to be linear with the square root of time. NR composites reinforced with untreated, acid-activated, and ion-exchanged zeolite fillers indicate reduction in wax blooming as compared to unfilled NR. The bloom rate (slope and initial bloom (y-intercept were determined from the experimental plots. Analysis of variance (ANOVA shows the bloom rate to be signif icantly increased when zeolite fillers are treated with GMS. Meanwhile, initial bloom was significantly enhanced when zeolite fillers are treated with TDA chloride salt and GMS. The significant increase in bloom rate and initial bloom can be attributed to the softening of the NR matrix at high amounts of TDA chloride salt and GMS.

  14. Wax Modeling and Image Analysis for Classroom-Scale Lava Flow Simulations. (United States)

    Rader, E. L.; Clarke, A. B.; Vanderkluysen, L.


    The use of polyethylene glycol wax (PEG 600) as an analog for lava allows for a visual representation of the complex physical process occurring in natural lava flows, including cooling, breakouts, and crust and lobe formation. We used a series of cameras positioned around a tank filled with chilled water as a lab bench to observe and quantify lava flow morphology and motion. A peristaltic pump connected to a vent at the base of the tank delivered dyed wax simulating effusive eruptions similar to those of Kilauea in Hawai`i. By varying the eruptive conditions such as wax temperature and eruption rate, students can observe how the crust forms on wax flows, how different textures result, and how a flow field evolves with time. Recorded footage of the same `eruption' can then be quantitatively analyzed using free software like ImageJ and Tracker to quantify time-series of spreading rate, change in height, and appearance of different surface morphologies. Additional dye colors can be added periodically to further illustrate how lava is transported from the vent to the periphery of a flow field (e.g., through a tube system). Data collected from this activity can be compared to active lava flow footage from Hawai`i and with numerical models of lava flow propagation, followed by discussions of the application of these data and concepts to predicting the behavior of lava in hazard management situations and interpreting paleomagnetic, petrologic, and mapping of older eruptions.

  15. A theoretical approach to evaluate the release rate of acetaminophen from erosive wax matrix dosage forms. (United States)

    Agata, Yasuyoshi; Iwao, Yasunori; Shiino, Kai; Miyagishima, Atsuo; Itai, Shigeru


    To predict drug dissolution and understand the mechanisms of drug release from wax matrix dosage forms containing glyceryl monostearate (GM; a wax base), aminoalkyl methacrylate copolymer E (AMCE; a pH-dependent functional polymer), and acetaminophen (APAP; a model drug), we tried to derive a novel mathematical model with respect to erosion and diffusion theory. Our model exhibited good agreement with the whole set of experimentally obtained values pertaining to APAP release at pH 4.0 and pH 6.5. In addition, this model revealed that the eroding speed of wax matrices was strongly influenced by the loading content of AMCE, but not that of APAP, and that the diffusion coefficient increased as APAP loading decreased and AMCE loading increased, thus directly defining the physicochemical properties of erosion and diffusion. Therefore, this model might prove a useful equation for the precise prediction of dissolution and for understanding the mechanisms of drug release from wax matrix dosage forms. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Preparation of margarines from organogels of sunflower wax and vegetable oils (United States)

    It was previously reported that sunflower wax (SW) had high potential as an organogelator for soybean oil-based margarine and spread products. In this study twelve other vegetable oils were evaluated in a margarine formulation to test feasibility of utilization of SW as an alternative to solid fats ...


    Directory of Open Access Journals (Sweden)

    Zulma Lizeth Tosne


    Full Text Available The chontaduro has a high nutritive value and it is one of the more complete fruits as a food, it is highly perishable, making it susceptible to damage and affecting its quality and acceptance. Because of that, the effect of coating based on enzimatically modified cassava starch (variety SM 707-17 and bees wax effect was evaluated on the weight loss, firmness, Brix grades, titratable acidity and the respiratory rate of the red variety fruits in post harvest step, stored under environmental conditions (18oC of temperature and 77,7 % of relative humidity. A complete random design with four treatments and three replicates was used; the treatments were: T1 control sample without no treatment, T2 with 0,5 % bees wax, T3 with 1,5 % bees wax, T4 with 2,5 % bees wax, all treatments were added with modified cassava starch (4% concentration, glycerin and carboximetilcelulose (CMC. The results were analyzed by an ANOVA (D=0,05 using the SPSS 19 software, with a level of significance (p<0,05 in the response variables, identifying T3 as the treatment with the higher incidence, maintaining the quality conditions of chontaduro for 4 additional days.

  18. [Non-destructive brand identification of car wax using visible and near-infrared spectroscopy]. (United States)

    Zhang, Yu; Tan, Li-Hong; He, Yong


    Visible and near-infrared (Vis-NIR) spectroscopy was applied to identify brands of car wax. A total of 104 samples were obtained for the analysis, in which 40 samples (calibration set) were used for model calibration, and the remaining 64 samples (prediction set) were used to validate the calibrated model independently. Linear discriminant analysis (LDA) and least square-support vector machine (LS-SVM) were respectively used to establish identification models for car wax with five brands based on their Vis-NIR spectra. Correct rates for prediction sample set were 84% and 97% for LDA and LS-SVM models, respectively. Spectral variable selection was further conducted by successive projections algorithm, (SPA), resulting in seven feature variables (351, 365, 401, 441, 605, 926, and 980 nm) selected from full range spectra that had 751 variables. The new LS-SVM model established using the feature variables selected by SPA also had the correct rate of 97%, showing that the selected variables had the most important information for brand identification, while other variables with no useful information were eliminated efficiently. The use of SPA and LS-SVM could not only obtain a high correct identification rate, but also simplify the model calibration and calculation. SPA-LS-SVM model could extract the useful information from the Vis-NIR spectra of car wax rapidly and accurately for the non-destructive brand identification of car wax.

  19. Grapefruit gland oil composition is affected by wax application, storage temperature, and storage time. (United States)

    Sun, D; Petracek, P D


    The effect of wax application, storage temperature (4 or 21 degrees C), and storage time (14 or 28 days after wax application) on grapefruit gland oil composition was examined by capillary gas chromatography. Wax application decreases nonanal and nootkatone levels. beta-Pinene, alpha-phellandrene, 3-carene, ocimene, octanol, trans-linalool oxide, and cis-p-mentha-2,8-dien-1-ol levels increase, but limonene levels decrease, with temperature. Levels of alpha-pinene, limonene, linalool, citronellal, alpha-terpineol, neral, dodecanal, and alpha-humulene decrease with time. Levels of alpha-phellandrene, 3-carene, ocimene, and trans-linalool oxide increase with time. No compound level was affected by the interactive action of temperature and wax application, suggesting that these two factors cause grapefruit oil gland collapse (postharvest pitting) through means other than changing gland oil composition. Compounds that are toxic to the Caribbean fruit fly (alpha-pinene, limonene, alpha-terpineol, and some aldehydes) decrease with time, thus suggesting grapefruit becomes increasingly susceptible to the fly during storage.

  20. The casting of western sculpture during the XIXth century: sand casting versus lost wax casting

    NARCIS (Netherlands)

    Beentjes, T.P.C.


    This paper will discuss research into bronze casting techniques as practiced during the XIXth and early XXth century. Both natural sand casting (fonte au sable naturel) and lost wax casting (fonte à la cire perdue) were employed during this period and sometimes rivalled for commissions. Before the X

  1. Antimicrobial activity of wax and hexane extracts from Citrus spp. peels


    Susana Johann; Vetúria Lopes de Oliveira; Pizzolatti,Moacir G.; Jan Schripsema; Raimundo Braz-Filho; Alexsandro Branco; Artur Smânia Jr


    Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp.), two human pathogens (Trichophyton mentagrophytes and Microsporum canis), and two opportunistic bacteria (Escherichia coli and Staphylococcus aureus). Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from pe...

  2. Thermodynamics Prediction of Wax Precipitation in Black Oil Using Regular Solution Model and Plus Fraction Characterization

    Directory of Open Access Journals (Sweden)

    Wei Wang


    Full Text Available The precipitation of wax/solid paraffin during production, transportation, and processing of crude oil is a serious problem. It is essential to have a reliable model to predict the wax appearance temperature and the amount of solid precipitated at different conditions. This paper presents a work to predict the solid precipitation based on solid-liquid equilibrium with regular solution-molecular thermodynamic theory and characterization of the crude oil plus fraction. Due to the differences of solubility characteristics between solid and liquid phase, the solubility parameters of liquid and solid phase are calculated by a modified model. The heat capacity change between solid and liquid phase is considered and estimated in the thermodynamic model. An activity coefficient based thermodynamic method combined with two characteristic methods to calculate wax precipitation in crude oil, especially heavy oil, has been tested with experimental data. The results show that the wax appearance temperature and the amount of weight precipitated can be predicted well with the experimental data.

  3. Properties of margarine and spread from wax-vegetable oil organogel (United States)

    Food products such as margarine and spread need solid fats for a desired texture and typically these solid fats contain high contents of saturated fats and trans-fats. In this research organogels formed by plant wax and soybean oil were utilized to produce trans-fat free margarine and spread. Base...

  4. Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating

    National Research Council Canada - National Science Library

    Asmaa Said; Abeer Salah; Gamal Abdel Fattah


    ..., and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers...

  5. Efficacy of wax matrix bait stations for Mediterranean Fruit Flies (Diptera: Tephritidae) (United States)

    Tests were conducted that evaluated efficacy of wax matrix bait stations for Ceratitis capitata (Wiedemann) adults in Guatemala. Bait stations were exposed to outdoor conditions to determine effect of weathering on longevity as indicated by bait station age. Results of laboratory tests found that ba...

  6. Characterization of a Soil Metagenome-Derived Gene Encoding Wax Ester Synthase. (United States)

    Kim, Nam Hee; Park, Ji-Hye; Chung, Eunsook; So, Hyun-Ah; Lee, Myung Hwan; Kim, Jin-Cheol; Hwang, Eul Chul; Lee, Seon-Woo


    A soil metagenome contains the genomes of all microbes included in a soil sample, including those that cannot be cultured. In this study, soil metagenome libraries were searched for microbial genes exhibiting lipolytic activity and those involved in potential lipid metabolism that could yield valuable products in microorganisms. One of the subclones derived from the original fosmid clone, pELP120, was selected for further analysis. A subclone spanning a 3.3 kb DNA fragment was found to encode for lipase/esterase and contained an additional partial open reading frame encoding a wax ester synthase (WES) motif. Consequently, both pELP120 and the full length of the gene potentially encoding WES were sequenced. To determine if the wes gene encoded a functioning WES protein that produced wax esters, gas chromatography-mass spectroscopy was conducted using ethyl acetate extract from an Escherichia coli strain that expressed the wes gene and was grown with hexadecanol. The ethyl acetate extract from this E. coli strain did indeed produce wax ester compounds of various carbon-chain lengths. DNA sequence analysis of the full-length gene revealed that the gene cluster may be derived from a member of Proteobacteria, whereas the clone does not contain any clear phylogenetic markers. These results suggest that the wes gene discovered in this study encodes a functional protein in E. coli and produces wax esters through a heterologous expression system.

  7. Physical characteristics of tetrahydroxy and acylated derivatives of jojoba liquid wax (United States)

    Jojoba liquid wax is a mixture of esters of long chain fatty acids and fatty alcohols, mainly (C38:2-C46:2). The oil exhibits excellent emolliency on the skin and therefore is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the Jojoba (Simmondsia...

  8. Wax barrier for use with in situ processes for treating formations (United States)

    Vinegar, Harold J.; Carter, Ernest E.; Son, Jaime Santos; Bai, Taixu; Khoda Verdian, Mohamad Fereydoon


    Methods for forming a barrier around at least a portion of a treatment area in a subsurface formation are described herein. A material including wax may be introduced into one or more wellbores. The material introduced into two or more wells may mix in the formation and congeal to form a barrier to fluid flow.

  9. Making Work: Demonstrating Thermodynamic Concepts with Solar-Powered Wax and Rubber Heat Engines (United States)

    Appleyard, S. J.


    Construction details are provided for simple heat engines that use candle wax and elastomers as working substances. The engines are constructed using common household materials and can be easily constructed in a school classroom or at home. They work reliably and are useful tools for demonstrating the conversion of heat to mechanical work. They…


    Directory of Open Access Journals (Sweden)



    Full Text Available Results of this study represent the first report of the effect of Naphthalene Acetic Acid (NAA on the pre and post harvest quality of wax apple fruit. The wax apple trees were spray treated with 0, 5, 10 and 20 mg L-1 NAA under field conditions during 2008 to 2011. The experiments were carried out in Completely Randomized Design (CRD with six replications. Leaf chlorophyll content, chlorophyll fluorescence, photosynthetic yield, net photosynthetic rate, drymatter content of leaves and total soluble solids and K+content of wax apple fruits were significantly increased after treatments with 10 mg L-1. Polygalacturonase activity significantly decreased with NAA treatments. The application of 5 mg L-1 NAA increased 27% more bud and reduced 42% less fruit drop compared to the control. In addition, higher protein and phosphate synthase activity of leaves, fruit set, fruit growth, larger fruit size and yield were recorded in NAA treated plants. In storage, treated fruits exhibited higher TSS and firmness and less weight loss, browning, titratable acidity, respiration and ethylene production than the control. It is concluded that spraying with 5 and 10 mg L-1 NAA once a week under field conditions produced better fruit growth and yield of the wax apple and maintained better fruit quality in postharvest storage.

  11. Demonstrating Electrophoretic Separation in a Straight Paper Channel Delimited by a Hydrophobic Wax Barrier (United States)

    Xu, Chunxiu; Lin, Wanqi; Cai, Longfei


    A demonstration is described of electrophoretic separation of carmine and sunset yellow with a paper-based device. The channel in the paper device was fabricated by hand with a wax pen. Electrophoretic separation of carmine and sunset yellow was achieved within a few minutes by applying potential on the channel using a simple and inexpensive power…

  12. Wax co-cracking synergism of high density polyethylene to alternative fuels

    Directory of Open Access Journals (Sweden)

    Magdy Motawie


    Full Text Available Attempts have been made to understand the thermal degradation of high density polyethylene (HDPE and their combined co-cracking using different ratios of HDPE and petroleum wax under nitrogen atmosphere. We have conducted the experiments using HDPE as the raw material and petroleum wax as co-feed by at 400 and 450 °C reaction temperatures. The product distribution was noted along with reaction time of 0.5–3 h for the degradation. Thermal gravimetric analysis (TGA technique was used to measure the weight change of the feedstock as a function of temperature and time. Differential scanning calorimetry (DSC was used to determine the degradation temperature. Products were characterized using gas chromatography (GC and infrared spectroscopy (FTIR, some other standard physical methods were used to determine the main properties of the liquid products. Results show that the mixed plastic-wax samples could be converted into gases, gasoline, and middle distillate depending upon the composition of feed polymer/wax ratio. It was found that the products mostly consisted of paraffin and olefin compounds, with carbon numbers of C1–C4, C5–C9 and C10–C19 in the case of gases, gasoline and middle distillate respectively.

  13. Electro- and photodriven phase change composites based on wax-infiltrated carbon nanotube sponges. (United States)

    Chen, Liangjie; Zou, Ruqiang; Xia, Wei; Liu, Zhenpu; Shang, Yuanyuan; Zhu, Jinlong; Wang, Yingxia; Lin, Jianhua; Xia, Dingguo; Cao, Anyuan


    Organic phase change materials are usually insulating in nature, and they are unlikely to directly trigger latent heat storage through an electrical way. Here we report a multifunctional phase change composite in which the energy storage can be driven by small voltages (e.g., 1.5 V) or light illumination with high electro-to-heat or photo-to-thermal storage efficiencies (40% to 60%). The composite is composed of paraffin wax infiltrated into a porous, deformable carbon nanotube sponge; the latter not only acts as a flexible encapsulation scaffold for wax but also maintains a highly conductive network during the phase change process (for both solid and liquid states). Uniform interpenetration between the nanotube network and paraffin wax with high affinity results in enhanced phase change enthalpy and thermal conductivity compared to pure paraffin wax. Our phase change composite can store energy in practical ways such as by sunlight absorption or under voltages applied by conventional lithium-ion batteries.

  14. Infrared Spectroscopic Analysis of Chrysene and 1.2-Benzanthracence in Wax films

    Institute of Scientific and Technical Information of China (English)

    Md. Naziruddin Khan; A. S. Al-Dwayyan; Z. H. Zaidi


    @@ Chrysene and 1.2-benzanthracene are successfully doped in a solid wax film and their vibrational spectra in2000-400 cm- 1 are discussed. The harmonic frequencies and relative intensities of both the molecules observed in the film are compared with theoretical values calculated by the density functional theory (DFT) model as well as with the previous experimental data.

  15. Crystallography of the polymethylene chain an inquiry into the structure of waxes

    CERN Document Server

    Dorset, Douglas L


    By considering the solid state packing of linear chain wax components, this work investigates which modifications of molecular components are allowed for maintaining stable solid solutions; what happens when stability conditions are traversed and fractionation begins; and the structure of fractionated arrays.

  16. Sources and abundances of leaf waxes in aerosols in central Europe (United States)

    Nelson, Daniel B.; Knohl, Alexander; Sachse, Dirk; Schefuß, Enno; Kahmen, Ansgar


    Atmospheric transport is an understudied mechanism for leaf wax hydrogen isotope applications that contributes to mobilizing and depositing these compounds on the surface of the Earth. While previous efforts have identified the importance of atmospheric leaf wax deposition in remote marine locations, the processes are not well constrained on land in temperate latitudes where lakes are common and sedimentary leaf wax hydrogen isotope values are an attractive tool for understanding past precipitation changes. This work presents results from a field study that was conducted in 2010 and 2011 at Hainich National Park, Germany in order to evaluate the quantity and sources of leaf waxes in the atmosphere. Aerosols were sampled at approximately weekly intervals inside the forest canopy, and n-alkane distributions and hydrogen isotope values were compared with those from major tree species surrounding the sampling site. Despite sampling in what was expected to be a major production center, the distribution and hydrogen isotope values of atmospheric n-alkanes bore little resemblance to those of the local vegetation. Comparison with local meteorological data and to 10-day and 36-h back air mass trajectories indicated shifting effects of winds and temperature, and that mesoscale transport processes were more important than long-range mechanisms. Back trajectories also highlighted source effects, with easterly winds coinciding with relatively lower leaf wax hydrogen isotope values from more continental regions. These results suggest that leaf wax aerosols average over spatial scales that exceed typical surface catchment areas for small lake systems, even in forested areas, yet that the area over which these compounds are derived is still relatively regional. Depositional fluxes were also estimated in order to assess the potential importance of atmospheric transport to sedimentary archives. Although difficult to constrain, these estimates suggest that atmospheric deposition may

  17. The usage, occurrence and dietary intakes of white mineral oils and waxes in Europe. (United States)

    Tennant, D R


    Dietary exposures to mineral hydrocarbons were estimated from information about patterns of usage, concentrations in foods and quantities of foods consumed. An industry survey showed that the largest usage of food-grade white mineral oils was in plastics manufacture although the majority are used in non-food applications. The largest volumes of wax usage were in packaging. Conservative estimates indicated that daily intakes of white mineral oils ranged from 0.39 to 0.91 mg/kg bw/day for adults and from 0.75 to 1.77 mg/kg bw/day for children (mean and 97.5th percentiles). Total wax intakes ranged from 0.08 to 0.19 mg/kg bw/day for adults and 0.23 to 0.64 mg/kg bw/day for pre-school children. When usage factors were applied, estimates of chronic intakes of white oils were reduced to 0.09-0.20 mg/kg bw/day for adults and to 0.17-0.39 mg/kg bw/day for children. Total wax intakes were reduced to 0.01-0.02 mg/kg bw/day for adults and to 0.02-0.06 mg/kg bw/day for children. For white mineral oils the principal source of exposure for most consumers was imported de-dusted grain. The principal source of potential wax exposure was from glazing agents on confectionery. There was no evidence of intakes exceeding SCF ADIs for microcrystalline waxes or certain white mineral oils and levels of exposure were similar to those of naturally-occurring mineral hydrocarbons in foods.

  18. Altitude effect on leaf wax carbon isotopic composition in humid tropical forests (United States)

    Wu, Mong Sin; Feakins, Sarah J.; Martin, Roberta E.; Shenkin, Alexander; Bentley, Lisa Patrick; Blonder, Benjamin; Salinas, Norma; Asner, Gregory P.; Malhi, Yadvinder


    The carbon isotopic composition of plant leaf wax biomarkers is commonly used to reconstruct paleoenvironmental conditions. Adding to the limited calibration information available for modern tropical forests, we analyzed plant leaf and leaf wax carbon isotopic compositions in forest canopy trees across a highly biodiverse, 3.3 km elevation gradient on the eastern flank of the Andes Mountains. We sampled the dominant tree species and assessed their relative abundance in each tree community. In total, 405 sunlit canopy leaves were sampled across 129 species and nine forest plots along the elevation profile for bulk leaf and leaf wax n-alkane (C27-C33) concentration and carbon isotopic analyses (δ13C); a subset (76 individuals, 29 species, five forest plots) were additionally analyzed for n-alkanoic acid (C22-C32) concentrations and δ13C. δ13C values display trends of +0.87 ± 0.16‰ km-1 (95% CI, r2 = 0.96, p families, suggesting the biochemical response to environment is robust to taxonomic turnover. We calculate fractionations and compare to adiabatic gradients, environmental variables, leaf wax n-alkane concentrations, and sun/shade position to assess factors influencing foliar chemical response. For the 4 km forested elevation range of the Andes, 4-6‰ higher δ13C values are expected for upland versus lowland C3 plant bulk leaves and their n-alkyl lipids, and we expect this pattern to be a systematic feature of very wet tropical montane environments. This elevation dependency of δ13C values should inform interpretations of sedimentary archives, as 13C-enriched values may derive from C4 grasses, petrogenic inputs or upland C3 plants. Finally, we outline the potential for leaf wax carbon isotopes to trace biomarker sourcing within catchments and for paleoaltimetry.

  19. Does plant colour matter? Wax accumulation as an indicator of decline in Juniperus thurifera. (United States)

    Esteban, R; Fernández-Marín, B; Olano, J M; Becerril, J M; García-Plazaola, J I


    The photosynthesis in evergreen trees living in Mediterranean ecosystems is subjected to multiple climatic stresses due to water shortage and high temperatures during the summer and to low temperatures during the winter. Mediterranean perennials deploy different photoprotective mechanisms to prevent damage to the photosynthetic system. Wax accumulation in leaves is a primary response which by enhancing light scattering in the leaf surface reduces incident radiation in the mesophyll. The existence of high variability in wax accumulation levels between coexisting individuals of a species has a visual effect on colour that provides distinguishable green and glaucous phenotypes. We explored this variability in a Mediterranean evergreen tree Juniperus thurifera (L.) to evaluate the impact of epicuticular wax on optical and ecophysiological properties and on the abundance of photoprotective pigments throughout an annual cycle. Because of light attenuation by waxes, we expected that glaucous phenotypes would lower the need for photoprotective pigments. We evaluated the effect of phenotype and season on reflectance, defoliation levels, photochemical efficiency and photoprotective pigment contents in 20 green and 20 glaucous junipers. Contrary to our expectations, the results showed that glaucous trees suffered from a diminution in photochemical efficiency, but there was no reduction in photoprotective pigments. Differences between glaucous and green phenotypes were greater in winter, which is the most stressful season for this species. Glaucous individuals also showed the highest levels of leaf defoliation. The lower photochemical efficiency of glaucous trees, together with higher defoliation rates and equal or greater number of physiological photoprotective mechanisms, suggests that in spite of wax accumulation, glaucous trees suffer from more severe stress than green ones. This result suggests that changes in colouration in Mediterranean evergreens may be a decline

  20. Combined hydrogen and carbon isotopes of plant waxes as an indicator of drought impacts on ancient Maya agriculture (United States)

    Douglas, P. M.; Pagani, M.; Eglinton, T. I.; Brenner, M.; Hodell, D. A.; Curtis, J. H.


    There is increasing evidence suggesting that a series of droughts in the Yucatan Peninsula coincided with the Terminal Classic decline of the Classic Maya civilization (ca. 1250 to 1000 years BP). However, there is little evidence directly linking climatic change and changes in human activities in this region. In this study we combine plant-wax δD, δ13C, and Δ14C analyses in two lake sediment cores from southeastern Mexico and northern Guatemala to develop coupled records of hydroclimate variability and human-driven vegetation change. Plant-wax specific Δ14C ages indicate a large input of pre-aged plant waxes into lake sediment. Comparison of plant-wax δD records with other regional hydroclimate proxy records suggest that plant-wax ages are evenly distributed around plant-wax radiocarbon ages, and that applying an age model based on plant-wax radiocarbon ages is appropriate for these lake sediments. We evaluate how differences in plant-wax age distributions influence stable isotope records to assess the age uncertainty associated with records of climate and vegetation change derived from plant-wax stable isotopes. In this low-elevation tropical environment plant-wax δ13C is largely controlled by the relative abundance of C3 and C4 plants. The ancient Maya practiced widespread maize (C4) agriculture and strongly influenced regional C3-C4 vegetation dynamics. Under natural conditions C4 plant coverage and plant-wax δ13C would tend to co-vary positively since C4 plants are well adapted for dry conditions. Under ancient Maya land-use, however, this relationship is likely to be decoupled, since drought would have disrupted C4 agriculture. Combined analysis of plant-wax δD and δ13C from both lakes indicates increasingly divergent trends following ca. 3500 years BP, around the onset of widespread ancient Maya agriculture. After this time high plant-wax δD values tend to correspond with low plant-wax δ13C values and vice versa. This pattern is consistent with

  1. Development and evaluation of sustained-release ibuprofen-wax microspheres. I. Effect of formulation variables on physical characteristics. (United States)

    Adeyeye, C M; Price, J C


    A congealable disperse phase encapsulation method was used to prepare sustained-release ibuprofen-wax microspheres. Microspheres prepared with paraffin wax, such as ceresine and microcrystalline waxes, using polyvinylpyrrolidone (PVP) as dispersant had a tendency to aggregate, but the addition of wax modifiers (stearyl alcohol and glyceryl monostearate) greatly reduced aggregation. Optimum modifier and dispersant concentrations were 20% (w/w) and 5% (w/v), respectively. The particle size distribution of the microspheres was log-normal. An increase in modifier, dispersant concentration, emulsification stirring speed, or temperature shifted the size distribution toward finer particles. Microcrystalline wax required a higher emulsification temperature and produced finer particles than ozokerite wax. The recovery of drug from the different microsphere formulations varied between 71 and 92%. Differential scanning calorimetry (DSC) of the single components and physical mixtures showed endothermic peaks at the respective melting-point ranges. The DSC of the ceresine and microcrystalline wax microspheres was similar to rescans of ternary mixtures of components of the microspheres with less prominent and lower melting temperatures than individual components or physical mixtures.

  2. Effect of new type of synthetic waxes on reduced production and compaction temperature of asphalt mixture with reclaimed asphalt (United States)

    Valentová, Tereza; Benešová, Lucie; Mastný, Jan; Valentin, Jan


    Lower mixing and paving temperatures of asphalt mixtures, which are an important issue in recent years, with respect to increased energy demand of civil engineering structures during their processing, allow reduction of this demand and result in minimized greenhouse gas production. In present time, there are many possibilities how to achieve reduction of production temperature during the mixing and paving of an asphalt mixture. The existing solutions distinguish in target operating temperature behaviour which has to be achieved in terms of good workability. This paper is focused on technical solutions based on use of new types of selected synthetic and bio-based waxes. In case of bio-based additive sugar cane wax was used, which is free of paraffins and is reclaimed as waste product during processing of sugar cane. The used waxes are added to bituminous binder in form of free-flowing granules or fine-grained powder. Synthetic waxes are represented by new series of Fischer-Tropsch wax in form of fine granules as well as by polyethylene waxes in form of fine-grained powder or granules. Those waxes were used to modify a standard paving grade bitumen dosed into asphalt mixture of ACsurf type containing up to 30 % of reclaimed asphalt (RA).

  3. Understanding nucleic acid structural changes by comparing wide-angle x-ray scattering (WAXS) experiments to molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Pabit, Suzette A. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA; Katz, Andrea M. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA; Tolokh, Igor S. [Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061, USA; Drozdetski, Aleksander [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA; Baker, Nathan [Pacific Northwest National Laboratory, Richland, Washington 99352, USA; Onufriev, Alexey V. [Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061, USA; Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA; Pollack, Lois [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA


    Wide-angle x-ray scattering (WAXS) is emerging as a powerful tool for increasing the resolution of solution structure measurements of biomolecules. Compared to its better known complement, small angle x-ray scattering (SAXS), WAXS targets higher scattering angles and can enhance structural studies of molecules by accessing finer details of solution structures. Although the extension from SAXS to WAXS is easy to implement experimentally, the computational tools required to fully harness the power of WAXS are still under development. Currently, WAXS is employed to study structural changes and ligand binding in proteins; however the methods are not as fully developed for nucleic acids. Here, we show how WAXS can qualitatively char- acterize nucleic acid structures as well as the small but significant structural changes driven by the addition of multivalent ions. We show the potential of WAXS to test all-atom molecular dynamics (MD) simulations and to provide insight in understanding how the trivalent ion cobalt(III) hexammine (CoHex) affects the structure of RNA and DNA helices. We find that MD simulations capture the RNA structural change that occurs due to addition of CoHex.

  4. Effect of spatial distribution of wax and PEG-isocyanate on the morphology and hydrophobicity of starch films. (United States)

    Muscat, Delina; Adhikari, Raju; Tobin, Mark J; McKnight, Stafford; Wakeling, Lara; Adhikari, Benu


    This study proposes a novel method for improving surface hydrophobicity of glycerol plasticized high amylose (HAG) films. We used polyethylene glycol isocyanate (PEG-iso) crosslinker to link HAG and three natural waxes (beeswax, candelilla wax and carnauba wax) to produce HAG+wax+PEG-iso films. The spatial distributions of wax and PEG-iso across the thickness of these films were determined using Synchrotron-based Fourier transform infrared spectroscopy. The hydrophobicity and surface morphology of the films were determined using contact angle (CA) and scanning electron microscopic measurements, respectively. The distribution patterns of wax and the PEG-iso across the thickness of the film, and the nature of crystalline patterns formed on the surface of these films were found to be the key factors affecting surface hydrophobicity. The highest hydrophobicity (CA >90°) was created when the PEG-iso was primarily distributed in the interior of the films and a hierarchical circular pinnacle structure of solidified wax was formed on the surface.

  5. Rice OsGL1-6 is involved in leaf cuticular wax accumulation and drought resistance.

    Directory of Open Access Journals (Sweden)

    Lingyan Zhou

    Full Text Available Cuticular wax is a class of organic compounds that comprises the outermost layer of plant surfaces. Plant cuticular wax, the last barrier of self-defense, plays an important role in plant growth and development. The OsGL1-6 gene, a member of the fatty aldehyde decarbonylase gene family, is highly homologous to Arabidopsis CER1, which is involved in cuticular wax biosynthesis. However, whether OsGL1-6 participates in cuticular wax biosynthesis remains unknown. In this study, an OsGL1-6 antisense-RNA vector driven by its own promoter was constructed and introduced into the rice variety Zhonghua11 by Agrobacterium-mediated transformation to obtain several independent transgenic plants with decreased OsGL1-6 expression. These OsGL1-6 antisense-RNA transgenic plants showed droopy leaves at the booting stage, significantly decreased leaf cuticular wax deposition, thinner cuticle membrane, increased chlorophyll leaching and water loss rates, and enhanced drought sensitivity. The OsGL1-6 gene was constitutively expressed in all examined organs and was very highly expressed in leaf epidermal cells and vascular bundles. The transient expression of OsGL1-6-GFP fusion indicated that OsGL1-6 is localized in the endoplasmic reticulum. Qualitative and quantitative analysis of the wax composition using gas chromatography-mass spectrometry revealed a significantly reduced total cuticular wax load on the leaf blades of the OsGL1-6 antisense-RNA transgenic plants as well as markedly decreased alkane and aldehyde contents. Their primary alcohol contents increased significantly compared with those in the wild type plants, suggesting that OsGL1-6 is associated with the decarbonylation pathways in wax biosynthesis. We propose that OsGL1-6 is involved in the accumulation of leaf cuticular wax and directly impacts drought resistance in rice.

  6. Pre-aged plant waxes in tropical lake sediments and their influence on the chronology of molecular paleoclimate proxy records (United States)

    Douglas, Peter M. J.; Pagani, Mark; Eglinton, Timothy I.; Brenner, Mark; Hodell, David A.; Curtis, Jason H.; Ma, Keith F.; Breckenridge, Andy


    Sedimentary records of plant-wax hydrogen (δDwax) and carbon (δ13Cwax) stable isotopes are increasingly applied to infer past climate change. Compound-specific radiocarbon analyses, however, indicate that long time lags can occur between the synthesis of plant waxes and their subsequent deposition in marginal marine sediments. The influence of these time lags on interpretations of plant-wax stable isotope records is presently unconstrained, and it is unclear whether such time lags also affect lacustrine sediments. We present compound-specific radiocarbon (14Cwax) data for n-alkanoic acid plant waxes (n-C26 to n-C32) from: (1) a sediment core from Lake Chichancanab, Yucatan Peninsula, Mexico, (2) soils in the Lake Chichancanab catchment, and (3) surface sediments from three other lakes in southeastern Mexico and northern Guatemala. 14Cwax ages in the surface sediments are consistently older than modern, and may be negatively correlated with mean annual precipitation and positively correlated with lake catchment area. 14Cwax ages in soils surrounding Lake Chichancanab increase with soil depth, consistent with deep, subsoil horizons being the primary source of lacustrine aged plant waxes, which are likely delivered to lake sediments through subsurface transport. Plant waxes in the Lake Chichancanab core are 350-1200 years older than corresponding ages of bulk sediment deposition, determined by 14C dates on terrestrial plant macrofossils in the core. A δDwax time series is in closer agreement with other regional proxy hydroclimate records when a plant-wax 14C age model is applied, as opposed to the macrofossil-based core chronology. Inverse modeling of plant-wax age distribution parameters suggests that plant waxes in the Lake Chichancanab sediment core derive predominantly from millennial-age soil carbon pools that exhibit relatively little age variance (soils. They also underscore the importance of direct radiocarbon dating of these organic molecules.

  7. Alleviation of High Temperature Stress in Wax Begonia (Begonia × semperflorens?cultorum Hort.) by Salicylic Acid


    Lin, Ling-Na; Huang, Kuang Liang; Okuibo, Hiroshi


    Wax begonia (Begonia × semperflorens?cultorum Hort.) plants often suffer from high temperature stress during hot seasons in Taiwan. Since salicylic acid (SA) has proved to enhance heat tolerance in many plants, this study evaluates whether exogenous SA applications could alleviate high temperature stress of wax begonias. Plug seedlings of wax begonia ‘Super Olympia’ were treated with 25, 100, 400, 800, with 1600 μM SA before 55 °C, for 2 h of high temperature stress. Results indicated that 25...

  8. Advances in Emulsified Wax for Leather Finishes%皮革涂饰乳化蜡的研究进展

    Institute of Scientific and Technical Information of China (English)



    The preparation method and action principle of emulsified wax for leather finishes were introduced,and then the research advances in emulsified wax for leather finishes at home and abroad were reviewed.Finally,some suggestions for developing emulsified wax for leather finishes were provided.%介绍了皮革涂饰乳化蜡的制备方法及作用原理,综述了国内外皮革涂饰乳化蜡的应用研究进展,对国内皮革涂饰乳化蜡的发展提了几点参考意见。

  9. Production Actuality and Breeding Trend of Wax Gourd%冬瓜生产现状与育种趋势

    Institute of Scientific and Technical Information of China (English)



    综述了冬瓜生产现状以及国内研究状况,并分析了目前冬瓜生产及研究中存在的主要问题,对未来冬瓜的研究、育种方向及发展趋势进行了展望。%This paper summed up the present actuality of was gourd production and research progress in wax gourd breeding and so on, analyzed the primary problems in wax gourd production and study, and discussed the developmental trend and breeding direction of wax gourd in the future.

  10. Experimental investigations of thermophysical properties of some paraffin waxes industrially manufactured in Poland (United States)

    Zbińkowski, Piotr; Zmywaczyk, Janusz; Koniorczyk, Piotr


    Phase-change materials (PCM) can be applied as a heat absorbing/releasing medium in passive cooling systems. Such systems can be used in cooling and temperature stabilization of electronic components, i.e., Li-ion batteries, photovoltaic modules or light emitting diodes (LED). In order to optimize heat transfer in passive cooling systems experimental studies of PCM thermophysical properties are necessary. A good PCM candidate for passive cooling systems may be paraffin waxes due to their relatively high latent heat of fusion (L 200 J.g-1), suitable for working of electronic devices range of melting temperatures (22 °C - 68 °C) and a reasonable price. However, their main drawback is a relatively low thermal conductivity k ranging from 0.148 W.m-1.K-1 to 0.358 W.m-1.K-1. In this paper were presented results of experimentally determined temperature characteristics of thermophysical parameters of four paraffin waxes industrially manufactured in Jasło/Poland by POLWAX. The density ρ of the test paraffin waxes determined at room temperature (20 °C) using a laboratory balance RADWAG X/60/220 comprised from 0.82 to 0.94 The thermal diffusivity κ of paraffin waxes was tested within temperature range from -50 °C to 30 °C every 20 °C interval using the NETZSCH LFA 467 HyperFlash. The test specimens having form of cylinder were 12.7 mm in diameter and 2.15 - 2.20 mm in height. Prior to the experiment the face and the back surface of each specimen were coated with a thin layer of graphite 33 having a thickness of several micrometers in accordance with the recommendation given by NETZSCH. The thermal diffusivity of the test paraffin waxes within temperature interval -40 °C - 20 °C was determined to be 0.083 mm2.s-1 to 0.216 mm2.s-1. Thermal effects and the apparent heat capacity cp of the tested materials were measured in the temperature range from -10 °C to 100 °C using the NETZSCH DSC 404 F1 Pegasus at 10 K.min-1 heating/cooling rates in an

  11. Effect of epicuticular waxes from triticale on the feeding behaviour and mortality of the grain aphid, Sitobion avenae (Fabricius (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Wójcicka Agnieszka


    Full Text Available Surface waxes from wax-covered triticale plants (RAH 122 were sprayed on plants of the waxless genotype RAH 366 or the surface waxes were used to make artificial diet preparations. The results were significant increases in the mortality of apterous adults of the grain aphid Sitobion avenae (Fabricius (Hemiptera: Aphididae at all concentrations tested in comparison with those aphids which fed on the control plants or aphids which were reared on the diets. In the choice tests, most aphids settled on plants without surface waxes or on diet preparations which did not have surface waxes (the controls. When the concentration of the surface waxes was increased on one of the plants or surface waxes were increased in the diet preparation, the number of wandering aphids increased. Those aphids which did not wander were mainly on the waxless control plants or on the waxless diet preparations. Aphids did settle on those plants or on the diet preparations which had 100 and 1,000 μg · g-1 of surface wax. The aphids rarely settled on the diet preparations containing 10,000 μg ∙ g-1 of surface waxes. From these observations it appears that surface waxes can act as a feeding deterrent. Since aphids on plants with surface waxes, or aphids which settled on diet preparations with surface waxes, started to die earlier than aphids fed only the control plants or the control diet preparations, it is possible that the surface waxes had a toxic effect that led to early mortality. Thus, it can be said that the surface waxes caused feeding deterrence and had a toxic effect on the aphids.

  12. Multiple plant-wax compounds record differential sources and ecosystem structure in large river catchments (United States)

    Hemingway, Jordon D.; Schefuß, Enno; Dinga, Bienvenu Jean; Pryer, Helena; Galy, Valier V.


    The concentrations, distributions, and stable carbon isotopes (δ13C) of plant waxes carried by fluvial suspended sediments contain valuable information about terrestrial ecosystem characteristics. To properly interpret past changes recorded in sedimentary archives it is crucial to understand the sources and variability of exported plant waxes in modern systems on seasonal to inter-annual timescales. To determine such variability, we present concentrations and δ13C compositions of three compound classes (n-alkanes, n-alcohols, n-alkanoic acids) in a 34-month time series of suspended sediments from the outflow of the Congo River. We show that exported plant-dominated n-alkanes (C25-C35) represent a mixture of C3 and C4 end members, each with distinct molecular distributions, as evidenced by an 8.1 ± 0.7‰ (±1σ standard deviation) spread in δ13C values across chain-lengths, and weak correlations between individual homologue concentrations (r = 0.52-0.94). In contrast, plant-dominated n-alcohols (C26-C36) and n-alkanoic acids (C26-C36) exhibit stronger positive correlations (r = 0.70-0.99) between homologue concentrations and depleted δ13C values (individual homologues average ⩽-31.3‰ and -30.8‰, respectively), with lower δ13C variability across chain-lengths (2.6 ± 0.6‰ and 2.0 ± 1.1‰, respectively). All individual plant-wax lipids show little temporal δ13C variability throughout the time-series (1σ ⩽ 0.9‰), indicating that their stable carbon isotopes are not a sensitive tracer for temporal changes in plant-wax source in the Congo basin on seasonal to inter-annual timescales. Carbon-normalized concentrations and relative abundances of n-alcohols (19-58% of total plant-wax lipids) and n-alkanoic acids (26-76%) respond rapidly to seasonal changes in runoff, indicating that they are mostly derived from a recently entrained local source. In contrast, a lack of correlation with discharge and low, stable relative abundances (5-16%) indicate that

  13. Coupled isotopes of plant wax and hemicellulose markers record information on relative humidity and isotopic composition of precipitation

    National Research Council Canada - National Science Library

    M. Tuthorn; R. Zech; M. Ruppenthal; Y. Oelmann; A. Kahmen; H. F. del Valle; T. Eglinton; M. Zech


    ... δ18O on plant-derived sugars. Our results indicate that leaf wax biomarker δ2H values (δ2Hlipids) primarily reflect δ2Hsource water (precipitation), but are modulated by evapotranspirative enrichment...

  14. 甘蓝无蜡粉突变体叶表皮蜡质超微结构观察%Observation of Ultra Microstructure of Wax-less Mutant Epicuticular Wax on Cabbage

    Institute of Scientific and Technical Information of China (English)

    牟香丽; 王超; 王帅


    Different growth periods of epicuticular wax development on cabbage (Brassica olera-cea L. var. capitata L. ) leaves were observed by scanning electron microscope, and types of wax mutant and wild-type cabbage leaves were selected as materials. Results showed that some waxes crystals were found in the wax mutant, the waxes crystals were immature and granular in the entire growth period. Different structure of waxes crystals were found in the wild-type, granular and flaky were major crystals structure at seedling stage, while cylindrical and flaky at head-forming stage, flaky and linear at mature stage.%运用扫描电子显微镜对结球甘蓝无蜡粉突变体及野生型材料不同生长时期的叶表皮蜡质发育状况进行比较观察.结果表明:甘蓝无蜡粉突变体也有蜡质晶体存在,但蜡质发育不完全,整个生长期以颗粒状晶体结构为主;野生型不同生长时期表现出不同的蜡质晶体结构,苗期以颗粒状和片状为主,结球期以圆柱状和片状为主,成熟期以片状和线状为主.

  15. Real-time monitoring and measurement of wax deposition in pipelines via non-invasive electrical capacitance tomography (United States)

    Lock Sow Mei, Irene; Ismail, Idris; Shafquet, Areeba; Abdullah, Bawadi


    Tomographic analysis of the behavior of waxy crude oil in pipelines is important to permit appropriate corrective actions to be taken to remediate the wax deposit layer before pipelines are entirely plugged. In this study, a non-invasive/non-intrusive electrical capacitance tomography (ECT) system has been applied to provide real-time visualization of the formation of paraffin waxes and to measure the amount of wax fraction from the Malay Basin waxy crude oil sample under the static condition. Analogous expressions to estimate the wax fraction of the waxy crude oil across the temperatures range of 30-50 °C was obtained by using Otsu’s and Kuo’s threshold algorithms. Otsu’s method suggested that the wax fraction can be estimated by the correlation coefficient β =0.0459{{T}3}-5.3535{{T}2}+200.36T-2353.7 while Kuo’s method provides a similar correlation with β =0.0741{{T}3}-8.4915{{T}2}+314.96T-3721.2 . These correlations show good agreements with the results which are obtained from the conventional weighting method. This study suggested that Kuo’s threshold algorithm is more promising when integrated into the ECT system compared to Otsu’s algorithm because the former provides higher accuracy wax fraction measurement results below the wax appearance temperature for waxy crude oil. This study is significant because it serves as a preliminary investigation for the application of ECT in the oil and gas industry for online measurement and detection of wax fraction without causing disturbance to the process flow.

  16. De novo assembly and characterization of the transcriptome, and development of SSR markers in wax gourd (Benicasa hispida.

    Directory of Open Access Journals (Sweden)

    Biao Jiang

    Full Text Available BACKGROUND: Wax gourd is a widely used vegetable of Cucuribtaceae, and also has important medicinal and health values. However, the genomic resources of wax gourd were scarcity, and only a few nucleotide sequences could be obtained in public databases. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we examined transcriptome in wax gourd. More than 44 million of high quality reads were generated from five different tissues of wax gourd using Illumina paired-end sequencing technology. Approximately 4 Gbp data were generated, and de novo assembled into 65,059 unigenes, with an N50 of 1,132 bp. Based on sequence similarity search with known protein database, 36,070 (55.4% showed significant similarity to known proteins in Nr database, and 24,969 (38.4% had BLAST hits in Swiss-Prot database. Among the annotated unigenes, 14,994 of wax gourd unigenes were assigned to GO term annotation, and 23,977 were found to have COG classifications. In addition, a total of 18,713 unigenes were assigned to 281 KEGG pathways. Furthermore, 6,242 microsatellites (simple sequence repeats were detected as potential molecular markers in wax gourd. Two hundred primer pairs for SSRs were designed for validation of the amplification and polymorphism. The result showed that 170 of the 200 primer pairs were successfully amplified and 49 (28.8% of them exhibited polymorphisms. CONCLUSION/SIGNIFICANCE: Our study enriches the genomic resources of wax gourd and provides powerful information for future studies. The availability of this ample amount of information about the transcriptome and SSRs in wax gourd could serve as valuable basis for studies on the physiology, biochemistry, molecular genetics and molecular breeding of this important vegetable crop.

  17. Good night, squashbite: a 'how to' paper on better wax occlusal records. (United States)

    Shargill, Inderjit; Ashley, Martin


    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.

  18. Experimental Study on Wax Protective Coating for Wet Deep Silicon Etching Processes

    Institute of Scientific and Technical Information of China (English)

    JIANG Jian-liang; ULRICH Hilleringmann


    In order to protect the finished structures on the front side during deep silicon wet etching processes,the wax coating for double-sided etching process on the wafer is studied to separate the aforementioned structures from the strong aqueous bases. By way of heating and vacuumization, the air bubbles are expelled from the coating to extend the protection duration. The air pressure in the sealed chamber is 0. 026 7 Pa, and the temperature of the heated wafer is 300 ℃. Two kinds of the wax are used, and the corresponding photos of the etched wafer and the protection times are given. In 75 ℃ 10 % KOH solution, the protection duration is more than 8 h.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    A fundamental filtration study was started to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. Slurry-phase FTS in slurry bubble column reactor systems is the preferred mode of operation since the reaction is highly exothermic. Consequently, heavy wax products in one approach may be separated from catalyst particles before being removed from the reactor system. Achieving an efficient wax product separation from iron-based catalysts is one of the most challenging technical problems associated with slurry-phase iron-based FTS and is a key factor for optimizing operating costs. The separation problem is further compounded by attrition of iron catalyst particles and the formation of ultra-fine particles.

  20. Environmental and biosynthetic influences on carbon and hydrogen isotope ratios of leaf wax n-alkanes (United States)

    McInerney, F. A.; Freeman, K. H.; Polissar, P. J.; Feakins, S. J.


    Both carbon and hydrogen isotope ratios of leaf-wax n-alkanes are influenced by the availability of water in a plant's growth environment. Carbon isotope ratios of bulk tissues in C3 plants demonstrate a strong inverse relationship with measures of available moisture (e.g. mean annual precipitation and precipitation/evaporation). Similarly, hydrogen isotope ratios of leaf wax n-alkanes (δDl) can be enriched relative to precipitation (δDw) by transpiration, which is related to relative humidity and the leaf-to-air vapor pressure deficit. Thus, D-enrichment of leaf-wax n-alkanes relative to precipitation, termed the apparent fractionation (2ɛl/w), becomes more positive with increasing aridity. In theory, more positive values of leaf-wax δ13C (δ13Cl) and 2ɛl/w of leaf-wax n-alkanes should both correspond to more arid conditions in C3 plants. Here we review published and unpublished data on over 100 plants to examine this relationship. Contrary to expectations, C3 dicots show no clear relationship between δ13Cl and 2ɛl/w. This global lack of correlation is surprising given our understanding of aridity related isotopic effects in C3 plants. One possibility is that the implicit assumption of constant fractionation between lipid and bulk tissue is flawed due to the effects of different biosynthetic carriers and reaction pathways. We explore this possibility by examining the offset of leaf-wax carbon isotopes from the bulk leaf tissue (13ɛl/bulk). Different offsets would indicate additional biosynthetic processes are affecting δ13Cl in addition to any direct effects from aridity. We find that 13ɛl/bulk is highly variable, ranging from -1 to -16‰, which could explain the lack of correlation between δ13Cl and 2ɛl/w. In addition, 13ɛl/bulk values for C3 and C4 monocots (averages of -10.6 and -11.4‰ respectively) represent significantly greater offset between leaf wax and bulk tissue than in C3 dicots (average of -4.3‰), which is consistent with previous

  1. Evaluation of Physical Properties of Wax Mixtures Obtained From Recycling of Patterns Used in Precision Casting

    Directory of Open Access Journals (Sweden)

    Biernacki R.


    Full Text Available The study investigated the properties of selected certified mixtures used to make wax patterns for the production of precision castings for the aerospace industry. In addition, an assessment of the recycled mixtures consisting of certified wax materials recovered during autoclaving was carried out. Hardness was tested via a proposed method based on penetration, creep related deformation, bending strength and linear contraction. The hardness was studied on laboratory specimens and patterns made with the use of injection molding equipment. For these patterns, linear contraction was estimated at variable pressure and for different temperature injection parameters. Deformations connected with creep and resistance were evaluated on cylindrical specimens. Differences in creep resistance in relation to the hardness were observed depending on the type of pattern mixtures. Recycled mixture has a greater resistance and smaller linear contraction than certified mixtures used for making sprue, raisers and other parts of filler system.

  2. Rheological effects of commercial waxes and polyphosphoric acid in bitumen 160/220 low temperature performance

    Energy Technology Data Exchange (ETDEWEB)

    Ylva Edwards; Yuksel Tasdemir; Ulf Isacsson [Royal Institute of Technology (KTH), Stockholm (Sweden). Division of Highway Engineering


    Effects of adding three commercial waxes and a polyphosphoric acid to three bitumens of 160/220 penetration grade were studied using different types of laboratory equipment, such as dynamic shear rheometer (DSR), bending beam rheometer (BBR), differential scanning calorimeter (DSC), force ductilometer (FD) as well as equipment for determining conventional parameters like penetration, softening point and Fraass breaking point. The paper deals with low-temperature effects, which could influence the thermal cracking resistance of asphalt concrete pavements. The results show that magnitude and type of effect on bitumen rheology depend on the bitumen itself as well as type and amount of additive used. Bitumen composition was found to be of decisive importance. Adding polyethylene wax or polyphosphoric acid, especially to non-waxy 160/220-penetration grade bitumen, showed positive effects on the rheological behaviour at low temperatures. 24 refs., 6 figs., 5 tabs.

  3. Efficient and selective degradation of polyethylenes into liquid fuels and waxes under mild conditions. (United States)

    Jia, Xiangqing; Qin, Chuan; Friedberger, Tobias; Guan, Zhibin; Huang, Zheng


    Polyethylene (PE) is the largest-volume synthetic polymer, and its chemical inertness makes its degradation by low-energy processes a challenging problem. We report a tandem catalytic cross alkane metathesis method for highly efficient degradation of polyethylenes under mild conditions. With the use of widely available, low-value, short alkanes (for example, petroleum ethers) as cross metathesis partners, different types of polyethylenes with various molecular weights undergo complete conversion into useful liquid fuels and waxes. This method shows excellent selectivity for linear alkane formation, and the degradation product distribution (liquid fuels versus waxes) can be controlled by the catalyst structure and reaction time. In addition, the catalysts are compatible with various polyolefin additives; therefore, common plastic wastes, such as postconsumer polyethylene bottles, bags, and films could be converted into valuable chemical feedstocks without any pretreatment.

  4. Fabrication of a superhydrophobic surface on copper foil based on ammonium bicarbonate and paraffin wax coating (United States)

    Zeng, Ou; Wang, Xian; Yuan, Zhiqing; Wang, Menglei; Huang, Juan


    A simple and low cost approach was developed to fabricate a superhydrophobic surface on copper foil. The oxidation and etching of the copper foil surface were promoted in NH4HCO3 solution using a water and ethanol admixture as a component solvent. After 28 h in this solution, a hydrophilic rough surface structure was obtained on the copper foil surface. With modification using a paraffin wax coating, the hydrophilic rough copper surface changed to become hydrophobic or superhydrophobic. The surface morphology and wettability were characterized by scanning electron microscopy (SEM) and contact angle measurements, respectively. When the optimum concentration of paraffin wax was about 2 g L-1, its water contact angle could reach about 152 ± 1.5° and its sliding angle was around 7°. The formation mechanism of the rough copper surface was also explored in detail. Both the experimental process and the material are environmentally friendly.

  5. FTIR spectroscopy of synthesized racemic nonacosan-10-ol: a model compound for plant epicuticular waxes (United States)


    As there are no published graphically presented, detailed IR spectra of nonacosan-10-ol (occurring naturally and widely in plant epicuticular waxes of nanotube form), near IR FTIR spectroscopy (fundamentals, overtones and combinations) has been performed on laboratory synthesized racemic nonacosan-10-ol, as a crystalline solid on Mylar and polypropylene substrates. Room temperature, in vacuo data are presented graphically, in full, and show evidence of extensive hydrogen bonding, an orthorhombic perpendicular subcell, a methylene wagging progression, diagnostic of all-trans conformational order, and Fermi resonance. Moderate or stronger anharmonicity is confirmed. Detailed discussion, quantitative in parts, is given of the observed spectral features, especially as to how they inform crystal structure and molecular conformation, and assignments given for some of the features. The results will serve as a reference for future IR studies of the natural epicuticular wax nanotube form of (S)-nonacosan-10-ol. PMID:21886346

  6. Efficient and selective degradation of polyethylenes into liquid fuels and waxes under mild conditions (United States)

    Jia, Xiangqing; Qin, Chuan; Friedberger, Tobias; Guan, Zhibin; Huang, Zheng


    Polyethylene (PE) is the largest-volume synthetic polymer, and its chemical inertness makes its degradation by low-energy processes a challenging problem. We report a tandem catalytic cross alkane metathesis method for highly efficient degradation of polyethylenes under mild conditions. With the use of widely available, low-value, short alkanes (for example, petroleum ethers) as cross metathesis partners, different types of polyethylenes with various molecular weights undergo complete conversion into useful liquid fuels and waxes. This method shows excellent selectivity for linear alkane formation, and the degradation product distribution (liquid fuels versus waxes) can be controlled by the catalyst structure and reaction time. In addition, the catalysts are compatible with various polyolefin additives; therefore, common plastic wastes, such as postconsumer polyethylene bottles, bags, and films could be converted into valuable chemical feedstocks without any pretreatment. PMID:27386559

  7. Establishing very long-chain fatty alcohol and wax ester biosynthesis in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Wenning, Leonie; Yu, Tao; David, Florian


    for producing very long-chain fatty alcohols (VLCFOHs) up to a chain length of C22 by heterologous expression of a FAR derived from Apis mellifera (AmFAR1) or Marinobacter aquaeolei VT8 (Maqu_2220) in S. cerevisiae and achieved maximum yields of 3.22±0.36mg/g cell dry weight (CDW) and 7.84±3.09mg/g CDW......Wax esters (WEs) are neutral lipids and can be used for a broad range of commercial applications, including personal care products, lubricants, or coatings. They are synthesized by enzymatic reactions catalyzed by a fatty acyl reductase (FAR) and a wax ester synthase (WS). At present, commercially...

  8. A Novel MALDI Matrix for Analyzing Peptides and Proteins: Paraffin Wax Immobilized Matrix

    Institute of Scientific and Technical Information of China (English)

    WEI Yuanlong; MEI Yuan; XU Zhe; WANG Cuihong; GUO Yinlong; DU Yiping; ZHANG Weibing


    A new kind of MALDI matrix, termed paraffin wax immobilized matrix, was used to study peptide mixtures and proteins. During the preparation process, the paraffin wax was heated and coated on the stainless-steel target plate, and then 2,5-dihydrobenzoic acid (DHB) was deposited on the paraffin layer and stainless-steel target plate to obtain different kinds of matrix spots. The morphology of matrices on different supports and peptide-matrix co-crystallization were observed by a high resolution digital-video microscopy system. Peptide mixtures and bovine serum albumin (BSA) digests were used to investigate the performance of the immobilized matrices on the paraffin target. The MALDI-FTMS analysis results also showed that the detection sensitivity of matrices immobilized in the paraffin sample support was better than that on other sample supports.


    Directory of Open Access Journals (Sweden)



    Full Text Available After presenting the situation of forest decline in Italy and analyzing the factors that play a contributing role, tbis paper studies the response of the epicuticular wax structures and the stomata in ten broadleaf species and one conifer to fog-like treatments with acids andlor surfactants and to severe water stress. The main results are that wax structure alterations vary in intensity in the different species studied and that the microstructural alterations observed in field conditions cannot be attributed only to severe drought. since sample trccs put through water stress simulations do nol differ significantly from controls. In the artificial surfactant treatment, a positive relationship between structural damage to tbe stomata and transpiration suggests possible synergies between the effects of drought and those of pollutants in inducing stress conditions in Mediterranean vegetation.

  10. The importance of being Florentine: a journey around the world for wax anatomical Venuses. (United States)

    de Ceglia, Francesco Paolo


    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.

  11. Variations of the composition of the leaf cuticular wax among Chinese populations of Plantago major. (United States)

    Guo, Yanjun; He, Yuji; Guo, Na; Gao, Jianhua; Ni, Yu


    Plantago major L. grows in a very wide range of regions in China and exhibits great variations among populations. The analysis of the cuticular-wax composition provides a potential approach to classify populations of P. major confronting different environmental conditions. Twelve populations of P. major and five populations of P. depressa Willd., distributed over regions with average annual temperatures ranging from -2.0 to 18.4°, were sampled, the variation of the composition of their cuticular waxes was analyzed, and their values of average chain length (ACL) and carbon preference index (CPI) were calculated. Great intra- and interspecies variations were observed for the total wax contents. The average annual temperature of the habitats was significantly correlated with the relative contents of the dominant n-alkanes with an odd number of C-atoms, but not with the wax contents. With an increasing average annual temperature, the relative contents of n-alkanes C29 and C31 decreased, whereas those of C33 and C35 as well as the values of ACLtotal and ACL27-33 increased. Cluster analysis based on the pattern of the n-alkane distribution allowed to clearly separate the populations of P. major according to the average annual temperature of their habitats, but not to separate the populations of the two species. Hence, the pattern of the n-alkane distribution might be a good taxonomic marker for P. major at the intraspecies level, but not at the interspecies level. Nevertheless, a small difference between the populations of the two species was observed concerning the values of ACLtotal and CPItotal , implying the potential use of these indices for the classification of the populations of the two species at the interspecies level.

  12. Effect of expanded graphite on the phase change materials of high density polyethylene/wax blends

    Energy Technology Data Exchange (ETDEWEB)

    AlMaadeed, M.A., E-mail: [Center for Advanced Materials, Qatar University, 2713 Doha (Qatar); Labidi, Sami [Center for Advanced Materials, Qatar University, 2713 Doha (Qatar); Krupa, Igor [QAPCO Polymer Chair, Center for Advanced Materials, Qatar University, P.O. Box 2713, Doha (Qatar); Karkri, Mustapha [Université Paris-Est CERTES, 61 avenue du Général de Gaulle, 94010 Créteil (France)


    Highlights: • Expanded graphite (EG) and low melting point (42.3 °C) wax were added to HDPE to form phase change material. • EG was well dispersed in the composites and did not affect the melting or crystallization of the HDPE matrix. • EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. • The addition of a relatively small quantity of EG enhances the heat conduction in the composite. • HDPE/40% RT42 that contained up to 15% EG demonstrated excellent mechanical and thermal properties and can be used as PCM. - Abstract: Phase change materials fabricated from high density polyethylene (HDPE) blended with 40 or 50 wt% commercial wax (melting point of 43.08 °C) and up to 15 wt% expanded graphite (EG) were studied. Techniques including scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and an experimental device to measure diffusivity and conductivity (DICO) were used to determine the microstructural, mechanical and thermal properties of the composites. The composites possessed good mechanical properties. Additionally, no leaching was observed during material processing or characterization. Although the Young’s modulus increased with the addition of EG, no significant changes in tensile strength were detected. The maximum Young’s modulus achieved was 650 MPa for the HDPE/40% wax composite with 15 wt% EG. The EG was well dispersed within the composites and did not affect the melting or crystallization of the HDPE matrix. The incorporation of EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. The intensification of thermal conductivity occurred with increasing fractions of EG, which was attributed to the high thermal conductivity of graphite. The maximum quantity of heat stored by latent heat was found for the HDPE/40% wax composite with EG. The addition of a relatively small quantity

  13. Expression of annual cycles in preen wax composition in red knots: Constraints on the changing phenotype


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


    Birds living in seasonal environments change physiology and behavior in correspondence to temporally changing environmental supplies, demands and opportunities. We recently reported that the chemical composition of uropygial gland secretions of sandpipers (Scolopacidae, order Charadriformes) changes during the breeding season from mixtures of monoesters to diesters, which fulfill specific functions related to incubation. A proper temporal match between the expression of diester preen waxes an...

  14. Synergistic Extraction of Lanthanides by 1-Nitroso-2-Naphthol and Trioctylphosphine Oxide in Paraffin Wax

    Institute of Scientific and Technical Information of China (English)


    The paraffin wax was used as a diluent for 1-nitroso-2-naphthol(HA) and trioctylphosphine oxide(TOPO) in the extraction of lanthanides at 70℃. The composition of the extracted species was given as LnA3(TOPO)2 by means of the slope analysis. The variation of the synergistic extraction equilibrium constant(Ksex) was investigated at 60~80℃, and the thermodynamic data were calculated. The dependence of separation factors on temperature was also studied.

  15. Model predictions for the WAXS signals of healthy and malignant breast duct biopsies (United States)

    LeClair, R. J.


    A wide-angle x-ray scatter (WAXS) measurement could potentially be used to determine whether a biopsy of a breast duct is healthy or malignant. A ductal carcinoma in situ (DCIS) occurs when the epithelial cells lining the wall start to replicate and invade the duct interior. Since cells are composed mainly of water a WAXS signal of DCIS could contain a larger component due to water. A model approximates that a breast duct biopsy consists of connective tissue (c.t.) and cells. For a 2 mm diameter 3.81 mm thick healthy duct biopsy, the volumes in cubic mm are 11.56 c.t. and 0.41 cells whereas 6.64 c.t. and 5.33 cells for DCIS. The differential linear scattering coefficients (μs) for both types of biopsies were calculated using the sum vc.t.μsc.t. + vcellμscell where v denotes fractional volume. The cell was assumed to be composed of water, lipids (fat), and other atoms associated with RNA, DNA, proteins, and carbohydrates. The μscell was calculated using the sum 0.771μswater + 0.023μsfat + 0.206μsother. The μs of c.t., water, and fat were available from literature whereas the independent atomic model approximation was used to calculate values for μsother. A WAXS model provided predictions of the number of 6 degree scattered photons Ns for incident 50 kV beams on healthy and malignant ducts. The sum of Ns between 31.5 <= E <= 45 keV were 1402 and 1529 for respectively the healthy and malignant biopsies. Using Poisson statistics, two Gaussian distributions, and a descision threshold set at their intersection, the false positive and false negative probabilities were 4.7% and 5.0%. This work suggests that DCIS could potentially be diagnosed via energy dispersive WAXS measurements.

  16. Controls on the D/H ratios of plant leaf waxes in an arid ecosystem (United States)

    Feakins, Sarah J.; Sessions, Alex L.


    The extent to which leaf water D-enrichment (transpiration) and soil water D-enrichment (evaporation) affect the D/H ratio of plant leaf waxes remains a contentious issue, with important implications for paleohydrologic reconstructions. In this study we measure δD values of precipitation ( δD p), groundwater ( δD gw), plant xylem water ( δD xw) and leaf water ( δD lw) to understand their impact on the δD values of plant leaf wax n-alkanes ( δD wax) in an arid ecosystem. Our survey includes multiple species at four sites across an aridity gradient (80-30% relative humidity) in southern California. We find that many species take up groundwater or precipitation without significant fractionation. D-enriched soil water is a minor source even in species known to perform and utilize waters from hydraulic lift, such as Larrea tridentata (+10‰). Measurements of leaf water isotopic composition demonstrate that transpiration is an important mechanism for D-enrichment of leaf waters (+74 ± 20‰, 1 σ), resulting in the smallest net fractionation yet reported between source water and leaf waxes ( L. tridentata -41‰; multi-species mean value is -94 ± 21‰, 1 σ). We find little change in leaf water D-enrichment or net fractionation across the climatic gradient sampled by our study, suggesting that a net fractionation of ca. -90‰ may be appropriate for paleohydrologic reconstructions in semi-arid to arid environments. Large interspecies offsets in net fractionations (1 σ = 21‰) are potentially troublesome, given the observed floristic diversity and the likelihood of species assemblage changes with climate shifts.

  17. Analysis of aliphatic waxes associated with root periderm or exodermis from eleven plant species. (United States)

    Kosma, Dylan K; Rice, Adam; Pollard, Mike


    Aliphatic waxes can be found in association with suberized tissues, including roots. Non-polar lipids were isolated by rapid solvent extraction of mature regions of intact roots from eleven angiosperms, including both monocots and dicots. The majority of roots analyzed were taproots or tuberous taproots that had undergone secondary growth and thus were covered by a suberized periderm. The exceptions therein were maize (Zea mays L.) and rice (Oryza sativa L.), which present a suberized exodermis. The analysis herein focused on aliphatic waxes, with particular emphasis on alkyl hydroxycinnamates (AHCs). AHCs were widely distributed, absent from only one species, were found in both aerial and subterranean portions of tuberous taproots, and were associated with the fibrous roots of both maize and rice. Most species also contained monoacylglycerols, fatty alcohols and/or free fatty acids. Carrot (Daucus carrota L.) was the outlier, containing only free fatty acids, sterols, and polyacetylenes as identified components. Sterols were the only ubiquitous component across all roots analyzed. Monoacylglycerols of ω-hydroxy fatty acids were present in maize and rice root waxes. For species within the Brassiceae, wax compositions varied between subspecies or varieties and between aerial and subterranean portions of taproots. In addition, reduced forms of photo-oxidation products of ω-hydroxy oleate and its corresponding dicarboxylic acid (10,18-dihydroxy-octadec-8-enoate, 9,18-dihydroxy-octadec-10-enoate and 9-hydroxyoctadec-10-ene-1,18-dioate) were identified as naturally occurring suberin monomers in rutabaga (Brassica napus subsp. rapifera Metzg.) periderm tissues.

  18. Flow and linear coefficient of thermal expansion of four types of Base Plate waxes compared with ADA standard

    Directory of Open Access Journals (Sweden)

    Monzavi A


    Full Text Available Waxes have a lot of applications in dentistry. Such materials are of thermoplastic type that undergoes deformation in different temperatures. Two important properties of base plate waxes are flow and their coefficient of linear thermal expansion. Recently, different institutions, inside the country, produce dentistry waxes, while they have not been standardized. Consequently, consumers' dissatisfaction are observed. In this research, the two above- mentioned factors were compared between three kinds of Iranian waxes with Cavex that is foreign production, based on test number 24 of ADA. To measure the flow rate in the temperatures of 23, 37 and 45°c, Wilcoxon statistical analysis was used. The results showed that in 23°c, the flow rate of Cavex and Azardent waxes met ADA standards; however, it was not true for two others types. In 37°c, the flow of none of the waxes was standardized and in 45°c their flow was acceptable, moreover, thermal expansion coefficient, for Cavex and Azardent types, was based on ADA standard.

  19. Growth and wax ester production of an Acinetobacter baylyi ADP1 mutant deficient in exopolysaccharide capsule synthesis. (United States)

    Kannisto, Matti; Efimova, Elena; Karp, Matti; Santala, Ville


    Acinetobacter baylyi ADP1 naturally produces wax esters that could be used as a raw material in industrial applications. We attempted to improve wax ester yield of A. baylyi ADP1 by removing rmlA, a gene involved in exopolysaccharide production. Growth rate, biomass formation and wax ester yield on 4-hydroxybenzoate were not affected, but the rmlA (-) strain grew slower on acetate, while reaching similar biomass and wax ester yield. The rmlA (-) cells had malformed shape and large size and grew poorly on glucose without expression of the gene for pyruvate kinase (pykF) from Escherichia coli. The pykF-expressing rmlA (-) strain had similar growth rate, lowered biomass formation and improved wax ester production on glucose as compared to the wild-type strain expressing pykF. Cultivation of the pykF-expressing rmlA (-) strain on an elevated glucose concentration in a medium supplemented with amino acids resulted in doubled molar wax ester yield and acetate production.

  20. Evaluation of methods for wax determination in crude oil; Avaliacao de metodos de determinacao de parafinas em petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Julio Cesar M.; Silva, Maria do Socorro A.J. da; Vasconcellos, Rosa C.U. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Tamanqueira, Juliana B. [Fundacao Gorceix, Ouro Preto, MG (Brazil)


    Determining the wax content of crude oil is of great importance for petroleum industry, especially for production, storage and transportation of crude oils. Many different methodologies of wax determining are available in the technical literature. However, the selection of the most suitable method must be in accordance with the aim of the analysis and observing the specificities of each technique. The purpose of this work was to determine the performance of different techniques of wax determining applied to characterization of precipitation properties of waxy compounds in crude oils. Twelve samples of crude oils proceeding from the main Brazilian oil producing sedimentary basins were selected for this study. These samples were analyzed by three important analytical techniques of wax determining: precipitation by cooled solvent; liquid chromatography with precipitation by cooled solvent; and liquid chromatography followed by gas chromatography. Differential scanning calorimetry data related to the wax crystallization in these oils were used as parameters of validation. The results obtained in this study indicate that the liquid chromatography followed by gas chromatography method has the best performance for wax determining in crude oils. (author)

  1. Comparison of margin discrepancy of complete gold crowns fabricated using printed, milled, and conventional hand-waxed patterns. (United States)

    Munoz, Sergio; Ramos, Van; Dickinson, Douglas P


    The recent application of printing for the fabrication of dental restorations has not been compared and evaluated for margin discrepancy (margin fit) with restorations fabricated using milling and conventional hand-waxing techniques. The purpose of this in vitro study was to evaluate and compare margin discrepancy of complete gold crowns (CGCs) fabricated from printed, milled, and conventional hand-waxed patterns. Thirty crown patterns were produced by each of 3 different methods: printed by ProJet DP 3000, milled by LAVA CNC 500, and hand waxed, then invested and cast into CGCs. Each crown was evaluated at 10 positions around the margin on the corresponding epoxy die under ×50 light microscopy to determine the mean and maximum margin discrepancy. Measurements were made using a micrometer positioning stage. The results were compared by ANOVA (α=.05). Milled and hand-waxed patterns were not statistically different from each other (P>.05), while printed patterns produced significantly higher mean and maximum margin discrepancy than milled and hand-waxed patterns (Ppatterns were not significantly different from each other. The ProJet DP 3000 printed patterns were significantly different from LAVA CNC 500 milled and hand-waxed patterns, with an overall poorer result. Fabricating CGCs from printed patterns produced a significantly higher number of crowns with unacceptable margin discrepancy (>120 μm). Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  2. Separation of boron from borated paraffin wax by pyrohydrolysis and alkali extraction methods and its determination using ion chromatography. (United States)

    Raut, Vaibhavi Vishwajeet; Jeyakumar, Subbiah; Shah, Dipti Jayesh; Thakur, Uday Kumar; Tomar, Bhupendra Singh; Ramakumar, Karanam Lakshminarayana


    A method based on the pyrohydrolysis extraction of boron and its quantification with ion chromatography was proposed for paraffin waxes borated with H3BO3 and B4C. The optimum pyrohydrolysis conditions were identified. Wax samples were mixed with U3O8, which prevents the sample from flare up, and also accelerates the extraction of boron. Pyrohydrolysis was carried out with moist O2 at 950°C for 60 and 90 min for wax with H3BO3 and wax with B4C, respectively. Two simple methods of separation based on alkali extraction and melting wax in alkali were also developed exclusively for wax with H3BO3. In all the separations, the recovery of B was above 98%. During IC separation, B was separated as boron-mannitol anion complex. Linear calibration was obtained it between 0.1 and 50 ppm of B, and LOD was calculated as 5 ppb (S/N = 3). The reproducibility was better than 5% (RSD).

  3. A new experimental method to prevent paraffin - wax formation on the crude oil wells: A field case study in Libya

    Directory of Open Access Journals (Sweden)

    Elhaddad Elnori E.


    Full Text Available Wax formation and deposition is one of the most common problems in oil producing wells. This problem occurs as a result of the reduction of the produced fluid temperature below the wax appearance temperature (range between 46°C and 50°C and the pour point temperature (range between 42°C and 44°C. In this study, two new methods for preventing wax formation were implemented on three oil wells in Libya, where the surface temperature is, normally, 29°C. In the first method, the gas was injected at a pressure of 83.3 bar and a temperature of 65°C (greater than the pour point temperature during the gas-lift operation. In the second method, wax inhibitors (Trichloroethylene-xylene (TEX, Ethylene copolymers, and Comb polymers were injected down the casings together with the gas. Field observations confirmed that by applying these techniques, the production string was kept clean and no wax was formed. The obtained results show that the wax formation could be prevented by both methods.

  4. Theoretical study of the prohibited mechanism for ethylene/vinyl acetate co-polymers to the wax crystal growth. (United States)

    Zhang, Jinli; Zhang, Ming; Wan, Junjie; Li, Wei


    To understand the effect of pour point depressants (PPD) on the wax growth is important for designing PPD additives for use with different oils with high efficiency and good economics. In our current study, molecular mechanics, molecular dynamics, and quantum mechanics calculations were performed to investigate the prohibited mechanism of ethylene/vinyl acetate (EVA) additives on the paraffin deposition in oils. On the wax surface, a single C18 molecule and clusters were preferably deposited on the wax surface (010) in a parallel conformation, which resulted in the formation of large blocks of wax crystal. MD simulation indicated that the linear conformation of EVA was more favorable to be adsorbed onto the carbon backbone of the wax surface (010) with the polar fragments of vinyl acetate staying upside of the surface. Furthermore, four EVA molecules can efficiently optimize the inhibition effect for the deposition of the solute C18 molecules over 10x8 size wax surface (010). According to the simulation results, a simplified rational model was established to estimate the minimum dosage of EVA-type PPD for fuels with different paraffin contents. In a certain degree, this simplified model has provided an effective route to correlate microstructures and the properties of polymer-involving systems, which will shed light on the application of theoretical studies in industries.

  5. Control of the wax moth Galleria mellonella L. (Lepidoptera: Pyralidae by the male sterile technique (MST

    Directory of Open Access Journals (Sweden)

    Jafari Reza


    Full Text Available In this study we examined the control of wax moth using the male sterile technique (MST with gamma-rays. To determine the safe and effective dosage of gamma-rays capable of sterilizing male pupae of the wax moth, male pupae were exposed to increasing single doses of gamma-rays (250, 300, 350 and 400 Gy. The release ratio of sterile to normal males was also studied in a similar experiment. Treatments included sterile males, normal males and virgin females at the following ratios: 1:1:1, 2:1:1, 3:1:1, 4:1:1 and 5:1:1. Possible parthenogenetic reproduction of this pest was also examined. The results showed that 350 Gy was the most effective dose capable of sterilizing the male pupae of the wax moth. The best release ratio was established at four sterile males, one normal male for each normal female (4:1:1. Also females were incapable of producing offspring without males.

  6. Safety and efficacy of bone wax in patients on oral anticoagulant therapy. (United States)

    Krasny, Marta; Krasny, Kornel; Fiedor, Piotr


    Cardiovascular conditions, apart from neoplastic diseases, remain the major cause of death in developed countries; therefore, the number of patients receiving oral anticoagulants is constantly increasing. Anticoagulant therapy considerably reduced mortality in patients with history of myocardial infarction among others. Although many interventions may be performed without withdrawal of the anticoagulant and tooth extraction was qualified as a procedure of low hemorrhage risk, a majority of dentists refer the patient to a cardiologist several days before the elective tooth extraction to withdraw anticoagulants. The aim of the study was to evaluate the efficacy and safety of bone wax used to stop bleeding after dental procedures in a group of patients on chronic anticoagulant therapy and find an answer to a question, whether it is justified to temporarily withdraw anticoagulants for this type of procedures. The study involved 176 patients on chronic anticoagulant therapy undergoing tooth extraction (154 subjects) or surgical extraction of a retained tooth (48 subjects). After the procedure, in each case the alveolus was filled with bone wax to stop bleeding. In all patients involved in the study bleeding from the alveolus was successfully stopped during the procedure. None of the subjects reported increased bleeding from the operational site after coming back home. Bone wax is a good, efficient, and safe material to block bleeding from the alveolus following tooth extractions, also in patients on chronic anticoagulant therapy. The study demonstrated that withdrawal or adjustment of anticoagulant therapy is not necessary before an elective tooth extraction.

  7. Metabolic engineering of plant oils and waxes for use as industrial feedstocks. (United States)

    Vanhercke, Thomas; Wood, Craig C; Stymne, Sten; Singh, Surinder P; Green, Allan G


    Society has come to rely heavily on mineral oil for both energy and petrochemical needs. Plant lipids are uniquely suited to serve as a renewable source of high-value fatty acids for use as chemical feedstocks and as a substitute for current petrochemicals. Despite the broad variety of acyl structures encountered in nature and the cloning of many genes involved in their biosynthesis, attempts at engineering economic levels of specialty industrial fatty acids in major oilseed crops have so far met with only limited success. Much of the progress has been hampered by an incomplete knowledge of the fatty acid biosynthesis and accumulation pathways. This review covers new insights based on metabolic flux and reverse engineering studies that have changed our view of plant oil synthesis from a mostly linear process to instead an intricate network with acyl fluxes differing between plant species. These insights are leading to new strategies for high-level production of industrial fatty acids and waxes. Furthermore, progress in increasing the levels of oil and wax structures in storage and vegetative tissues has the potential to yield novel lipid production platforms. The challenge and opportunity for the next decade will be to marry these technologies when engineering current and new crops for the sustainable production of oil and wax feedstocks. © 2012 CSIRO Plant Biotechnology Journal © 2012 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  8. Application of carnauba-based wax maintains postharvest quality of 'Ortanique' tangor

    Directory of Open Access Journals (Sweden)

    Francisca Ligia de Castro Machado


    Full Text Available This study aimed at evaluating compositional changes in the quality of 'Ortanique' tangor after coating with the carnauba-based waxes Aruá Tropical® or Star Light®. The storage conditions studied simulated those of local marketing (22 ± 2 °C, 60 ± 5% RH. Non-destructive analysis, mass loss, peel color, and sensory evaluation, were performed upon coating and every three days up to the fifteenth day of storage. Destructive analysis, peel moisture content, chlorophyll of the peel, pulp color, juice content, soluble solids (SS, titratable acidity (TA, pH, and soluble solids to titratable acidity ratio, were performed upon coating and every four days up to the sixteenth day of storage. The assay was conducted using an entirely randomized design, with three replications (destructive analyses or ten replications (non-destructive analyses, in a split plot scheme. Wax-coating, especially Aruá Tropical®, maintained fruit freshness by reducing mass loss and peel dehydration and retaining green color. Peel moisture content, chlorophyll content, and juice content had lower rates in the wax coated fruits. Puncture force, soluble solids, titratable acidity, pH, and soluble solids to titratable acidity ratio varied vary little over the course of storage. Sensory evaluation showed that the application of Aruá Tropical keeps 'Ortanique' tangor fresher for 6 days longer for commercialization.

  9. Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating (United States)

    Said, Asmaa; Salah, Abeer; Abdel Fattah, Gamal


    Thermo-optical switches are of particular significance in communications networks where increasingly high switching speeds are required. Phase change materials (PCMs), in particular those based on paraffin wax, provide wealth of exciting applications with unusual thermally-induced switching properties, only limited by paraffin’s rather low thermal conductivity. In this paper, the use of different carbon fillers as thermal conductivity enhancers for paraffin has been investigated, and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers. Differential Scanning Calorimetry (DSC) and Scanning electron microscope (SEM) are performed on paraffin wax composites, and specific heat capacities are calculated based on DSC measurements. Thermo-optical switching based on transmission is measured as a function of the host concentration under conventional electric heating and laser heating of paraffin-carbon fillers composites. Further enhancements in thermo-optical switching parameters are studied under Nd:YAG laser heating. This novel structure can be used in future networks with huge bandwidth requirements and electric noise free remote aerial laser switching applications. PMID:28772884

  10. The resistance of surfaces treated with oils and waxes to the action of dry heat

    Directory of Open Access Journals (Sweden)

    Jaić Milan


    Full Text Available Surface treatment of wood can be done with different coatings, and the choice of the appropriate system of processing depends on several factors, such as technological, aesthetic, economic and ecological. Raising awareness of the need to preserve the living and working environment has had a crucial impact on the increase in the use of natural materials for surface treatment of wood - oil and wax. The application of oils and waxes allows surface treated wood to keep the natural look, while protecting it from different influences, which can cause degradation and deterioration of the final product. The paper presents the results of testing the resistance of beech surface (Fagus silvatica L. processed with linseed oil and beeswax to the action of dry heat. In order to compare the quality of surface treated with oil and/or wax, beech wood treated with 2K-polyurethane coating is taken as a reference of surface treatment of wood. Surfaces treated with beeswax are less resistant to dry heat than those treated with linseed oil, and both showed significantly less resistance than surface treated with 2K-polyurethane coating.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    In the previous reporting period, modifications were completed for integrating a continuous wax filtration system for a 4 liter slurry bubble column reactor. During the current reporting period, a shakedown of the system was completed. Several problems were encountered with the progressive cavity pump used to circulate the wax/catalyst slurry though the cross-flow filter element and reactor. During the activation of the catalyst with elevated temperature (> 270 C) the elastomer pump stator released sulfur thereby totally deactivating the iron-based catalyst. Difficulties in maintaining an acceptable leak rate from the pump seal and stator housing were also encountered. Consequently, the system leak rate exceeded the expected production rate of wax; therefore, no online filtration could be accomplished. Work continued regarding the characterization of ultra-fine catalyst structures. The effect of carbidation on the morphology of iron hydroxide oxide particles was the focus of the study during this reporting period. Oxidation of Fe (II) sulfate results in predominantly {gamma}-FeOOH particles which have a rod-shaped (nano-needles) crystalline structure. Carbidation of the prepared {gamma}-FeOOH with CO at atmospheric pressure produced iron carbides with spherical layered structure. HRTEM and EDS analysis revealed that carbidation of {gamma}-FeOOH particles changes the initial nano-needles morphology and generates ultrafine carbide particles with irregular spherical shape.

  12. Insecticidal Properties of a Highly Potent Wax Isolated from Dolichandra cynanchoides Cham. (United States)

    Díaz Napal, Georgina; Carpinella, María C; Palacios, Sara M


    Bioassay-guided fractionation of an ethanolic extract of the aerial parts of Dolichandra cynanchoides Cham. (Bignoniaceae) led to the isolation of a natural wax with anti-insect activity against Spodoptera frugiperda (Noctuidae) and Epilachna paenulata (Coleptera). The compound was identified spectroscopically as an ester of a C27 fatty acid and a C25 alcohol, pentacosyl heptacosanoate (1). The effective doses of 1 for 50% feeding inhibition (ED50) of S. frugiperda and E. paenulata were 0.82 and 8.53 µg/cm², respectively, in a choice test, while azadirachtin showed ED50 of 0.10 and 0.59 µg/cm², respectively. In a no-choice test, both insects refused to feed on leaves treated with 1 at doses of 0.1 µg/cm² or greater inhibiting larval growth and dramatically reducing survival. The lethal doses 50 (LD50) of 1 were 0.39 and 0.68 µg/cm² for S. frugiperda and E. paenulata, respectively. These results indicate that 1 has potential for development as botanical insecticides. Similar esters might be obtainable in large quantities as many edible crops produce wax esters that are discarded during food processing. Research on these materials could lead to the detection of similar waxes with insecticidal activity.

  13. Phase Change Material Trade Study: A Comparison Between Wax and Water for Manned Spacecraft (United States)

    Quinn, Gregory; Hodgson, Ed; Stephan, Ryan A,


    Phase change material heat sinks have been recognized as an important tool in optimizing thermal control systems for space exploration vehicles and habitats that must deal with widely varying thermal loads and environments. In order to better focus technology investment in this arena, NASA has supported a trade study with the objective of identifying where the best potential pay-off can be found among identified aqueous and paraffin wax phase change materials and phase change material heat sink design approaches. The study used a representative exploration mission with well understood parameters to support the trade. Additional sensitivity studies were performed to ensure the applicability of study results across varying systems and destinations. Results from the study indicate that replacing a wax PCM heat sink with a water ice PCM heat sink has the potential to decrease the equivalent system mass of the mission s vehicle through a combination of a smaller heat sink and a slight 5% increase in radiator size or the addition of a lightweight heat pump. An evaluation of existing and emerging PCM heat sink technologies indicates that further mass savings should be achievable through continued development of those technologies. The largest mass savings may be realized by eliminating the melting and freezing pressure of wax and water, respectively.

  14. Biodiesel from Jojoba oil-wax: Transesterification with methanol and properties as a fuel

    Energy Technology Data Exchange (ETDEWEB)

    Canoira, Laureano; Alcantara, Ramon; Garcia-Martinez, Jesus; Carrasco, Jesus [Department of Chemical Engineering and Fuels, School of Mines, Polytechnic University of Madrid, Rios Rosas 21, 28003-Madrid (Spain)


    The Jojoba oil-wax is extracted from the seeds of the Jojoba (Simmondsia chinensis Link Schneider), a perennial shrub that grows in semi desert areas in some parts of the world. The main uses of Jojoba oil-wax are in the cosmetics and pharmaceutical industry, but new uses could arise related to the search of new energetic crops. This paper summarizes a process to convert the Jojoba oil-wax to biodiesel by transesterification with methanol, catalysed with sodium methoxide (1wt% of the oil). The transesterification reaction has been carried out in an autoclave at 60 deg C, with a molar ratio methanol/oil 7.5:1, and vigorous stirring (600rpm), reaching a quantitative conversion of the oil after 4h. The separation of the fatty acid methyl esters (the fraction rich in FAME, 79% FAME mixture; 21% fatty alcohols; 51% of methyl cis-11-eicosenoate) from the fatty alcohols rich fraction (72% fatty alcohols; 28% FAME mixture; 26% of cis-11-eicosen-1-ol, 36% of cis-13-docosen-1-ol) has been accomplished in a single crystallization step at low temperature (-18 deg C) from low boiling point petroleum ether. The fraction rich in FAME has a density (at 15 deg C), a kinematic viscosity (at 40 deg C), a cold filter plugging point and a high calorific value in the range of the European standard for biodiesel (EN 14214)

  15. Polar polymeric structures as wax dispersant flow improvers for paraffinic distillate fuels

    Energy Technology Data Exchange (ETDEWEB)

    El-Gamal, I.M.; Khidr, T.T.; Ghuiba, F.M. (Egyptian Petroleum Research Inst., Cairo (Egypt))


    Three (oxygen-based) and two (nitrogen + oxygen)-based polar polymeric structures were synthesized. The five copolymers were used as wax dispersant flow improver bifunctional additives (WDFI 1-5) for improving the cold flow properties of a paraffinic gas oil through cloud point (CP), cold filter plugging point (CFPP) and pour point (PP) tests. Results showed that the prepared additives exhibited high dispersing potential in terms of filterability improvement ([Delta]CFPP) correlated with the incorporated polar functional groups into their structures. On the contrary, their flowability in terms of ([Delta]PP) as flow improvers was not affected by polarity and appeared to depend primarily on the alkyl matching between copolymer alkyl chain moiety and average carbon number of wax content in the fuel. The prepared additives exhibited good compatibility with both natural wax dispersants and a commercial flow improver. The combined (nitrogen + oxygen)-based additive WDFI 5 has shown higher activity than oxygen-based ones and achieved the optimum effectiveness to the extent of 2, 8 and 15 C as [Delta]CP, [Delta]CFPP and [Delta]PP respectively. (orig.)

  16. Polar polymeric structures as wax dispersant flow improvers for paraffinic distillate fuels

    Energy Technology Data Exchange (ETDEWEB)

    El-Gamal, I.M.; Khidr, T.T.; Ghuiba, F.M. [Egyptian Petroleum Research Inst., Cairo (Egypt)


    Three (oxygen-based) and two (nitrogen + oxygen)-based polar polymeric structures were synthesized. The five copolymers were used as wax dispersant flow improver bifunctional additives (WDFI 1-5) for improving the cold flow properties of a paraffinic gas oil through cloud point (CP), cold filter plugging point (CFPP) and pour point (PP) tests. Results showed that the prepared additives exhibited high dispersing potential in terms of filterability improvement ({Delta}CFPP) correlated with the incorporated polar functional groups into their structures. On the contrary, their flowability in terms of ({Delta}PP) as flow improvers was not affected by polarity and appeared to depend primarily on the alkyl matching between copolymer alkyl chain moiety and average carbon number of wax content in the fuel. The prepared additives exhibited good compatibility with both natural wax dispersants and a commercial flow improver. The combined (nitrogen + oxygen)-based additive WDFI 5 has shown higher activity than oxygen-based ones and achieved the optimum effectiveness to the extent of 2, 8 and 15 C as {Delta}CP, {Delta}CFPP and {Delta}PP respectively. (orig.)

  17. The application of polymethylene waxes as conditioning agent in hair relaxers. (United States)

    Vermeulen, Shani; Van Rensburg, Audrey Jansen; Van Der Merwe, Belinda; Shalvoy, Richard; Willford, Suzanne


    Hair relaxers are harsh chemical treatments that leave the hair dull, dry and limp. There is a constant need for improvement of these products to make them milder and incorporate conditioning properties. Because of the high pH of relaxer or hair straightening systems, most quaternized (conditioning) ingredients are unstable and slowly break down to release ammonia over time, having no conditioning effects by the time the consumers use them. This paper discusses the partial substitution of the fatty alcohols that are traditionally used in relaxer systems with polymethylene wax and the benefits derived from using them. The study included the investigation of synergies among the ingredients, the stabilities of the various systems and comparisons with commercially available systems. The polymethylene wax, used in combination with the mineral oil gel and phosphate salt, coats the hair during the relaxing process, leaving it shiny, soft and conditioned as opposed to the poor condition of the hair relaxed by traditional, commercially available NaOH and LiOH relaxers. An additional benefit of using polymethylene wax in relaxer systems is that the conditioning agents that are normally added to the neutralizing shampoo to repair or mask the damage as a result of the relaxing process can be omitted.

  18. Inhibiting water evaporation of sandy soil by the soil particles modified with Japanese wax

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zeng-Zhi; WANG Hong-Juan; Li Cui-Lan


    This study was conducted to resolve the problems of water conservation of sandy soil in desertification areas. The surface of soil particles was modified by molecules of natural Japanese wax through some specially screened surfactant. The modified particles were then well sprayed onto the sand, which was placed in an artificial climate box with simulating desert environment, to form a soil film with effect of suppressing water and gas-permeability. Structure of soil film was analyzed by means of X-ray diffraction (XRD) and infrared spectrometry (IR). And its mechanism of water inhibition was illustrated with DSC and TG curves. Its influence on grass-planting was tested through the instruments of water detector. The results show that sorbitol anhydride stearate(Span 80)could well disperse the Japanese wax and make it combine with the clay which is also dispersed. The pores among soil particles grew smaller and turned from hydrophilic into hydrophobic, in which way resistance to water penetrating through the film was increased. Experimental grass grows normally on sandy soil with the soil film in the artificial desert climate box, indicating that the soil particles modified with Japanese wax is an effective method to inhibit water evaporation.

  19. Rice OsGL 1-1 Is Involved in Leaf Cuticular Wax and Cuticle Membrane

    Institute of Scientific and Technical Information of China (English)

    Bao-Xiang Qin; Ming-Hong Gu; Zhu-Kuan Cheng; Ding Tang; Jian Huang; Ming Li; Xin-Ru Wu; Li-Li Lu; Ke-Jian Wang; Heng-Xiu Yu; Jian-Min Chen


    Cuticular wax forms a hydrophobic barrier on aerial plant organs; it plays an important role in protectinga plant from damage caused by many forms of environmental stress.In the present study,we characterized a rice leafwax-deficient mutant osgl1-1 derived from a spontaneous mutation,which exhibited a wax-deficient and highly hydrophilic leaf phenotype.We cloned the OsGL1-1 gene by the map-based cloning method and performed a complementation test to confirm the function of the candidate gene.Molecular studies revealed that OsGL1-1 was a member of the OsGL1family,and contained regions that were homologous to some regions in sterol desaturases and short-chain dehydrogenases/reductases.Compared to the wild-type,the osgl1-1 mutant showed decreased cuticular wax deposition,thinner cuticular membrane,decreased chlorophyll leaching,increased rate of water loss,and enhanced sensitivity to drought.OsGL1-1 is expressed ubiquitously in rice.The transient expression of OsGL1-1-green fluorescent protein fusion protein indicated that OsGL1-1 is localized in the cytoplasm,plasma membrane,and nucleus.

  20. New MALDI matrices based on lithium salts for the analysis of hydrocarbons and wax esters. (United States)

    Horká, Petra; Vrkoslav, Vladimír; Hanus, Robert; Pecková, Karolina; Cvačka, Josef


    Lithium salts of organic aromatic acids (lithium benzoate, lithium salicylate, lithium vanillate, lithium 2,5-dimethoxybenzoate, lithium 2,5-dihydroxyterephthalate, lithium α-cyano-4-hydroxycinnamate and lithium sinapate) were synthesized and tested as potential matrices for the matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry analysis of hydrocarbons and wax esters. The analytes were desorbed using nitrogen laser (337.1 nm) and ionized via the attachment of a lithium cation, yielding [M + Li](+) adducts. The sample preparation and the experimental conditions were optimized for each matrix using stearyl behenate and n-triacontane standards. The performance of the new matrices in terms of signal intensity and reproducibility, the mass range occupied by matrix ions and the laser power threshold were studied and compared with a previously recommended lithium 2,5-dihydroxybenzoate matrix (LiDHB) (Cvačka and Svatoš, Rapid Commun. Mass Spectrom. 2003, 17, 2203). Several of the new matrices performed better than LiDHB. Lithium vanillate offered a 2-3 times and 7-9 times higher signal for wax esters and hydrocarbons, respectively. Also, the signal reproducibility improved substantially, making this matrix a suitable candidate for imaging applications. In addition, the diffuse reflectance spectra and solubility of the synthesized compounds were investigated and discussed with respect to the compound's ability to serve as MALDI matrices. The applicability of selected matrices was tested on natural samples of wax esters and hydrocarbons.

  1. Physical Properties, Volatiles Compositions and Sensory Descriptions of the Aromatized Hazelnut Oil-Wax Organogels. (United States)

    Yılmaz, Emin; Öğütcü, Mustafa; Yüceer, Yonca Karagül


    The purpose of this study was to determine the physicochemical, thermal and sensorial features of vitamin enriched and aromatized hazelnut oil-beeswax and sunflower wax organogels. Another objective was to monitor the influence of storage on textural and oxidative stability and volatile composition of the organogels. The results show that organogels with beeswax had lower levels of solid fat content, melting point and firmness than sunflower wax counterparts. The microphotographs revealed that beeswax organogels had spherical crystals while sunflower wax organogels continued need-like crystals, but both organogels continued crystallized β' polymorph. All organogels maintained their oxidative stability during storage. Quantitative descriptive analysis results were consistent with these findings that the organogel structure and properties were similar to breakfast margarine. The main volatile components of the organogels with added strawberry aroma were ethyl acetate, ethyl butanoate, ethyl-2-methyl butanoate, D-limonene, ethyl caproate; banana-aroma were isoamyl acetate, isoamyl valerianate, ethyl acetate; and butter-aroma were 2,3-butanedione, 3-hydroxy-2-butanone. These volatile components were not only detected in the fresh samples but also at the end of the storage period. Sensory definition terms were matched with the sensory descriptors of the detected volatiles. In conclusion, the new organogels were shown to be suitable for food product applications.

  2. Preparation and evaluation of waxes/fat microspheres loaded with lithium carbonate for controlled release

    Directory of Open Access Journals (Sweden)

    Gowda D


    Full Text Available To minimize the unwanted toxic effects of anti maniac drug lithium carbonate by kinetic control of drug release, it was entrapped into gastro resistant, biodegradable, waxes and fat such as beeswax, cetostearyl alcohol, spermaceti and cetylalcohol microspheres using meltable emulsified dispersion cooling induced solidification technique utilizing a wetting agent. Solid, discrete, reproducible free flowing microspheres were obtained. The yield of the microspheres was up to 90.0%. More than 98.0% of the isolated microspheres were of particle size range 115 to 855 mm. The microspheres had smooth surfaces, with free flowing and good packing properties. Scanning electron microscope confirmed their spherical structures within a size range of 339-355 mm. The drug loaded in waxes and fat microspheres was stable and compatible, as confirmed by DSC and FTIR studies. The release of drug was controlled for more than 8 hours. Intestinal drug release from waxes/ fat microspheres was studied and compared with the releases behavior of commercially available formulation Intalith CR ®-450. The release kinetics followed different transport mechanisms. The drug release performance was greatly affected by the materials used in microsphere preparations, which allows absorption in the intestinal tract.

  3. Surfactant-free dispersion of Montan wax and Montan resin; Tensidfreie Dispersion von Montanwachs und Montanharz

    Energy Technology Data Exchange (ETDEWEB)

    Wollenberg, R.; Naundorf, W. [Technische Univ. Bergakademie Freiberg (Germany); Abraham, J. [ROMONTA GmbH, Amsdorf (Germany)


    The purpose of this research project was the surfactant-free dispersion of lignite wax products in water in order to avoid the use of expensive surfactants that are employed in conventional process methods and some of which are harmful to the environment, and in some cases also impair the useful properties of the dispersed system. Based on experimental investigations, the wet grinding process at low temperatures below the melting point of the lignite wax products was developed. The products are surfactant-free watery dispersions of lignite wax or lignite resin. The new dispersed systems can be produced at low cost and have very good properties of use. (orig.) [German] Das Ziel der Forschung war die tensidfreie Dispergierung von Montanwachsprodukten in Wasser, um die in herkoemmlicher Verfahrensweise einzusetzenden teuren und teilweise umweltschaedlichen Tenside einzusparen, die in einigen Faellen auch die Anwendungseigenschaften des dispersen Systems beeintraechtigen. Auf der Basis von experimentellen Untersuchungen wurde das Nassmahlverfahren bei tiefen Temperaturen unter dem Schmelzpunkt der Montanwachsprodukte entwickelt. Die Produkte sind tensidfreie waessrige Dispersionen aus Montanwachs oder Montanharz. Die neuen dispersen Systeme sind kostenguenstig herstellbar und haben sehr gute Anwendungseigenschaften. (orig.)

  4. Micro- and nanoscale structures of mesiodens dentin: Combined study of FTIR and SAXS/WAXS techniques. (United States)

    Akgun, Ozlem Marti; Bayari, Sevgi Haman; Ide, Semra; Polat, Günseli Guven; Kalkhoran, Ilghar Orujalipoor


    A mesiodens is the most common type of supernumerary tooth present in conjunction to normal dentition. A mesiodens may commonly occur in the central region of the upper or lower jaw. A mesiodens is different from normal teeth in terms of structure and shape. The aim of this study is to evaluate the micro- and nanoscale structural properties of mesiodens dentin by combined small- and wide-angle X-ray scattering (SAXS/WAXS) and Fourier transform infrared (FTIR) spectroscopy. Five freshly extracted, noncarious mesiodens and five normal dentin disks prepared from human incisor teeth were compared. Using FTIR, the phosphate-to-amide I, carbonate-to-phosphate, and carbonate-to-amide I band area ratios and the crystallinity index were quantified. SAXS/WAXS were used to study the nanostructure of mesiodens. An increase in the mineral content in the mesiodens dentin with respect to the normal group was found. Crystallinity was also significantly increased and the protein content decreased in the mesiodens dentin compared with that of normal dentin. SAXS/WAXS results revealed that mesiodens dentin has a more calcified tissue. Further, SAXS analysis revealed a nonuniform distribution of dentin fibrils in mesiodens. © 2014 Wiley Periodicals, Inc.

  5. Alkanes in flower surface waxes of Momordica cochinchinensis influence attraction to Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae). (United States)

    Mukherjee, A; Sarkar, N; Barik, A


    Extraction, thin-layer chromatography, and gas chromatography-mass spectrophotometry analyses revealed 15 alkanes representing 97.14% of the total alkanes in the surface waxes of Momordica cochinchinensis Spreng flowers. Nonacosane was the prevailing alkane followed by hexatriacontane, nonadecane, heptacosane, and hentriacontane, accounting for 39.08%, 24.24%, 13.52%, 6.32%, and 5.12%, respectively. The alkanes from flower surface waxes followed by a synthetic mixture of alkanes mimicking alkanes of flower surface waxes elicited attraction of the female insect, Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) between 2 and 10-μg/mL concentrations in a Y-shaped glass tube olfactometer bioassay under laboratory conditions. Synthetic nonadecane from 178.28-891.37 ng, heptacosane from 118.14-590.72 ng, and nonacosane at 784.73 ng showed attraction of the insect. A synthetic mixture of 534.82 ng nonadecane, 354.43 ng heptacosane, and 2,354.18 ng nonacosane elicited highest attraction of A. foveicollis.

  6. Insecticidal Properties of a Highly Potent Wax Isolated from Dolichandra cynanchoides Cham

    Directory of Open Access Journals (Sweden)

    Georgina Díaz Napal


    Full Text Available Bioassay-guided fractionation of an ethanolic extract of the aerial parts of Dolichandra cynanchoides Cham. (Bignoniaceae led to the isolation of a natural wax with anti-insect activity against Spodoptera frugiperda (Noctuidae and Epilachna paenulata (Coleptera. The compound was identified spectroscopically as an ester of a C27 fatty acid and a C25 alcohol, pentacosyl heptacosanoate (1. The effective doses of 1 for 50% feeding inhibition (ED50 of S. frugiperda and E. paenulata were 0.82 and 8.53 µg/cm2, respectively, in a choice test, while azadirachtin showed ED50 of 0.10 and 0.59 µg/cm2, respectively. In a no-choice test, both insects refused to feed on leaves treated with 1 at doses of 0.1 µg/cm2 or greater inhibiting larval growth and dramatically reducing survival. The lethal doses 50 (LD50 of 1 were 0.39 and 0.68 µg/cm2 for S. frugiperda and E. paenulata, respectively. These results indicate that 1 has potential for development as botanical insecticides. Similar esters might be obtainable in large quantities as many edible crops produce wax esters that are discarded during food processing. Research on these materials could lead to the detection of similar waxes with insecticidal activity.

  7. Compositae Plants Differed in Leaf Cuticular Waxes between High and Low Altitudes. (United States)

    Guo, Na; Gao, Jianhua; He, Yuji; Guo, Yanjun


    We sampled eight Compositae species at high altitude (3482 m) and seven species at low altitude (220 m), analyzed the chemical compositions and contents of leaf cuticular wax, and calculated the values of average chain length (ACL), carbon preference index (CPI), dispersion (d), dispersion/weighted mean chain length (d/N), and C31 /(C31  + C29 ) (Norm31). The amounts of total wax and compositions were significantly higher at high altitude than at low altitude, except for primary alcohol, secondary alcohol, and ketone. The main n-alkanes in most samples were C31 , C29 , and C33 . Low altitude had more C31 and C33 , whereas more C29 occurred at high altitude. The ACL, CPI, d, d/N, and Norma 31 were higher at low altitude than at high altitude. The fatty acid and primary alcohol at low altitude contained more C26 homologous than at high altitude. More short-chain primary alcohols were observed at high altitude. At low altitude, the primary alcohol gave on average the largest amount, while it was n-alkane at high altitude. These results indicated that the variations of leaf cuticular waxes benefited Compositae plants to adapt to various environmental stresses and enlarge their distribution.

  8. Leaf Wax δ13C Varies with Elevation in the Peruvian Andes and Western Amazonia (United States)

    Wu, M. S.; Feakins, S. J.; Ponton, C.; Peters, T.; West, A. J.; Galy, V.; Bentley, L. P.; Salinas, N.; Shenkin, A.; Martin, R.; Asner, G. P.; Malhi, Y.


    Plant leaf wax carbon isotopic composition (δ13Cwax) reflects the net isotopic effects associated with diffusion into the leaf, fixation of carbon by Rubisco and biosynthesis of individual leaf wax biochemicals. As declining pCO2 with elevation affects the first two fractionations, we expect to find an isotopic gradient in δ13Cwax, if the fractionation of leaf wax biosynthesis is constant. To test this, we report δ13Cwax values from 500 samples of leaves collected by tree-climbers from the upper canopy from 9 forest-inventory plots spanning a 3.5km elevation transect in the Peruvian Andes and western Amazonia during the CHAMBASA field campaign. These samples provide a unique opportunity to study the relationship between δ13Cwax and pCO2 in diverse species across this remote tropical montane forest and lowland rainforest. The very wet climate throughout (2-5 m rainfall per year) minimizes fractionation effects due to stomatal restrictions (i.e. water use efficiency) that may be an important factor elsewhere. Preliminary results show δ13Cwax values on average increase with elevation by ~1.5‰/km, a trend consistent with bulk plant δ13C in previous studies. The mean epsilon between bulk and C29 n-alkane is -7.3±2.2‰. Inter-sample differences are large on the order of 10‰. Shaded leaves and understory leaves are found to be depleted relative to sunlit leaves, presumably due to a lower photosynthetic rate and use of respired CO2 in the understory. C29 n-alkanes are on average ~2.5‰ more depleted than C30 n-alkanoic acids, indicating fractionation during selective decarboxylation. We further compare results from plants with soil and river sediments to provide insights into how leaf wax signals are archived in soils and exported from the landscape. We find a ~1.4‰/km gradient in forest soils similar to plants. We observe a ~2‰ offset between C29 n-alkane in plant leaves and in soils across the elevation profile, which is likely a signal of degradation


    Institute of Scientific and Technical Information of China (English)

    孙东旭; 戴咏川; 齐程远; 彭昳达


    The oily Fischer-Tropsch wax was deoiled using MEK-toluene solvent.The solubilities of wax before and after deoiling in different solvents were tested.The results show that MEK-toluene mixed solvent is a suitable solvent for deoiling of the F-T wax.The XRD was used for analysis of wax crystal structure and DSC was used to measure the melting point of the waxes before and after deoiling.DSC results indicate that the melting point of the deoiled F-T wax is 90.68 ℃ and only has one melting peak without obvious solid-solid crystal transition, which is different from petroleum wax.%采用甲乙酮-甲苯溶剂对含油量较高的费-托合成蜡进行脱油精制,研究蜡脱油前后在不同溶剂中的溶解性能.结果表明:甲乙酮-甲苯溶剂可以作为费-托合成蜡脱油精制的溶剂.使用X射线衍射仪对蜡样品的晶体结构进行分析研究,用差示扫描量热法(DSC)测定脱油精制蜡样品的熔点为90.68 ℃.对蜡样品的DSC曲线分析表明:费-托合成蜡仅有一个熔融峰,没有明显的固-固晶体转变,这与石油蜡区别明显.

  10. Investigation on the production process of wax printing%冰纹蜡印花布生产工艺探讨

    Institute of Scientific and Technical Information of China (English)



    蜡纹是蜡印布的灵魂,自然丰富、细如发丝的冰纹使蜡印布风格更富有神韵,介绍了采用不同的蜡防材料比例配方,使蜡面既有弹性和韧性,又有一定的脆性,在机械外力下龟裂形成自然别致的冰纹.%Wax pattern is the soul of the wax printed cloth, its abundant natural and fine hair-like wax icy veins make the wax printed cloth full of charm. Different proportional formulations of wax substances were introduced, making the wax surface elastic, tough and brittle. Extraordinary wax icy veins will be formed under the external mechanical forces.

  11. Overexpression of the Novel Arabidopsis Gene At5g02890 Alters Inflorescence Stem Wax Composition and Affects Phytohormone Homeostasis (United States)

    Xu, Liping; Zeisler, Viktoria; Schreiber, Lukas; Gao, Jie; Hu, Kaining; Wen, Jing; Yi, Bin; Shen, Jinxiong; Ma, Chaozhi; Tu, Jinxing; Fu, Tingdong


    The cuticle is composed of cutin and cuticular wax. It covers the surfaces of land plants and protects them against environmental damage. At5g02890 encodes a novel protein in Arabidopsis thaliana. In the current study, protein sequence analysis showed that At5g02890 is highly conserved in the Brassicaceae. Arabidopsis lines overexpressing At5g02890 (OE-At5g02890 lines) and an At5g02890 orthologous gene from Brassica napus (OE-Bn1 lines) exhibited glossy stems. Chemical analysis revealed that overexpression of At5g02890 caused significant reductions in the levels of wax components longer than 28 carbons (C28) in inflorescence stems, whereas the levels of wax molecules of chain length C28 or shorter were significantly increased. Transcriptome analysis indicated that nine of 11 cuticular wax synthesis-related genes with different expression levels in OE-At5g02890 plants are involved in very-long-chain fatty acid (VLCFA) elongation. At5g02890 is localized to the endoplasmic reticulum (ER), which is consistent with its function in cuticular wax biosynthesis. These results demonstrate that the overexpression of At5g02890 alters cuticular wax composition by partially blocking VLCFA elongation of C28 and higher. In addition, detailed analysis of differentially expressed genes associated with plant hormones and endogenous phytohormone levels in wild-type and OE-At5g02890 plants indicated that abscisic acid (ABA), jasmonic acid (JA), and jasmonoyl-isoleucine (JA-Ile) biosynthesis, as well as polar auxin transport, were also affected by overexpression of At5g02890. Taken together, these findings indicate that overexpression of At5g02890 affects both cuticular wax biosynthesis and phytohormone homeostasis in Arabidopsis. PMID:28184233

  12. Molecular mapping and candidate gene analysis of a new epicuticular wax locus in sorghum (Sorghum bicolor L. Moench). (United States)

    Uttam, G Anurag; Praveen, M; Rao, Y Venkateswara; Tonapi, Vilas A; Madhusudhana, R


    A new epicuticular wax (bloom) locus has been identified and fine mapped to the 207.89 kb genomic region on chromosome 1. A putative candidate gene, Sobic.001G269200, annotated as GDSL-like lipase/acylhydrolase, is proposed as the most probable candidate gene involved in bloom synthesis/deposition. Deposition of epicuticular wax on plant aerial surface is one strategy that plants adapt to reduce non-transpiration water loss. Epicuticular wax (bloom)-less mutants in sorghum with their glossy phenotypes exhibit changes in the accumulation of epicuticular wax on leaf and culm surfaces. We report molecular mapping of a new sorghum locus, bloomless mutant (bm39), involved in epicuticular wax biosynthesis in sorghum. Inheritance studies involving a profusely bloom parent (BTx623) and a spontaneous bloomless mutant (RS647) indicated that the parents differed in a single gene for bloom synthesis. Bloomless was recessive to bloom deposition. Genetic mapping involving F2 and F7 mapping populations in diverse genetic backgrounds (BTx623 × RS647; 296A × RS647 and 27A × RS647) identified and validated the map location of bm39 to a region of 207.89 kb on chromosome 1. SSR markers, Sblm13 and Sblm16, flanked the bm39 locus to a map interval of 0.3 cM on either side. Nine candidate genes were identified, of which Sobic.001G269200 annotated for GDSL-like lipase/acylhydrolase is the most likely gene associated with epicuticular wax deposition. Gene expression analysis in parents, isogenic lines and sets of near isogenic lines also confirmed the reduced expression of the putative candidate gene. The study opens possibilities for a detailed molecular analysis of the gene, its role in epicuticular wax synthesis and deposition, and may help to understand its function in moisture stress tolerance and insect and pathogen resistance in sorghum.

  13. Influence of low-density polyethylene on the thermal characteristics and crystallinity of high melting point macro- and micro-crystalline waxes

    Energy Technology Data Exchange (ETDEWEB)

    Zaky, Magdy T., E-mail: [Petroleum Refining Division, Egyptian Petroleum Research Institute (EPRI), 1-Ahmed El-Zomor Street, Hai Al-Zehour, Nasr City, P.O. Box 11727, Cairo (Egypt); Mohamed, Nermen H. [Petroleum Refining Division, Egyptian Petroleum Research Institute (EPRI), 1-Ahmed El-Zomor Street, Hai Al-Zehour, Nasr City, P.O. Box 11727, Cairo (Egypt)


    The influence of low-density polyethylene on the thermal characteristics and the crystallinity of high melting point macro- and micro-crystalline waxes were investigated. The samples were prepared through melt blending using mechanical stirrer. The thermal characteristics of the blended samples were determined using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The crystallinity of the samples was obtained using X-ray diffraction analyzer (XRD). The observations are discussed in terms of possible changes when the polymer is mixed with two types of waxes. The wax-polymer miscibility differed with the type of the wax and the amount of polymer mixed into the wax. Also, the crystallinity and congealing point of the waxes differed with the amount of polymer mixed into the wax. Moreover, the resulting data indicate that, blending of polymer with high melting point micro-crystalline wax elevates its melting point to reach the limits of high melting point ceresin waxes which can be used in different industrial applications.

  14. Ultrastructure of Wax-Producing Structures on the Integument of the Melaleuca Psyllid Boreioglycaspis melaleucae (Hemiptera: Psyllidae), with Honeydew Excretion Behavior in Males and Females. (United States)

    Ammar, El-Desouky; Hentz, Matthew; Hall, David G; Shatters, Robert G


    The melaleuca psyllid, Boreioglycaspis melaleucae (Hemiptera: Psyllidae), was introduced to Florida as a biological control agent against Melaleuca quinquenervia, an invasive evergreen tree that has invaded large areas of Florida Everglades. Colonies of B. melaleucae nymphs are normally covered by white waxy secretions, and nymphs of various instars produce long bundles of white waxy filaments extending laterally and posteriorly from their abdomen. Scanning electron microscopy of 'naturally waxed' and 'dewaxed' nymphs (cleaned from wax) revealed two types of wax pore plates located dorsally and laterally on the integument of posterior abdominal segments starting with the 4th segment. Type-1 wax pore plates, with raised rim, peripheral groove, slits and pits, produce long ribbons and filaments of waxy secretions that are wound together forming long wax bundles, whereas type-2 wax pore plates, with slits only, produce shorter wax curls. Additionally, in both nymphs and adult females, the circumanal ring contained ornate rows of wax pores that produce wax filaments covering their honeydew excretions. Video recordings with stereomicroscopy showed that adult females produce whitish honeydew balls, powerfully propelled away from their body, probably to get these sticky excretions away from their eggs and newly hatched nymphs. Adult males, however, produce clear droplets of honeydew immediately behind them, simply by bending the posterior end of the abdomen downward. The possible role(s) of waxy secretions by nymphs and adults of B. melaleucae in reducing contamination of their colonies with honeydew, among other possibilities, are discussed.

  15. Chemical, dissolution stability and microscopic evaluation of suspensions of ibuprofen and sustained release ibuprofen-wax microspheres. (United States)

    Adeyeye, C M; Price, J C


    Chemical stability studies of suspensions of ibuprofen powder and ibuprofen-wax microspheres were performed using an accelerated stability protocol with a modified high performance liquid chromatography (HPLC) procedure. The variables considered were pH, suspending agents and temperature. The study showed little or no chemical degradation in the different suspending agents after storage for three months. Dissolution stability was examined in suspensions of ibuprofen microspheres made from an optimized formulation with 17% drug loading. The storage temperature were 23, 37 and 45 degrees C. Other variables for the dissolution stability studies were suspending agents, wax types, suspending medium pH and microsphere size. Suspensions of ceresine wax microspheres stored at 37 degrees C showed faster drug release than room temperature storage, but suspensions stored at 45 degrees C showed an opposite effect. Microspheres suspended in syrup and stored at 37 degrees C had faster dissolution rates than microspheres suspended in methylcellulose at the same temperature, possibly as a result of an interaction between the syrup and the microsphere constituents. Suspensions of microcrystalline wax microspheres had better dissolution stability than microspheres made from ceresine wax. Higher suspending medium pH resulted in faster release of drug from the suspended microspheres, but particle size did not significantly affect the dissolution stability.

  16. The Preparation and Performances of Self-Dispersed Nanomicron Emulsified Wax Solid Lubricant Ewax for Drilling Fluids

    Directory of Open Access Journals (Sweden)

    Feng-shan Zhou


    Full Text Available An oil-in-water nanomicron wax emulsion with oil phase content 45 wt% was prepared by using the emulsifying method of surfactant-in-oil. The optimum prepared condition is 85°C, 20 min, and 5 wt% complex emulsifiers. Then the abovementioned nanomicron emulsifying wax was immersed into a special water-soluble polymer in a certain percentage by the semidry technology. At last, a solidified self-dispersed nanomicron emulsified wax named as Ewax, a kind of solid lubricant for water based drilling fluid, was obtained after dried in the special soluble polymer containing emulsifying wax in low temperature. It is shown that the adhesion coefficient reduced rate (ΔKf is 73.5% and the extreme pressure (E-P friction coefficient reduced rate (Δf is 77.6% when the produced Ewax sample was added to fresh water based drilling fluid at dosage 1.0 wt%. In comparison with other normal similar liquid products, Ewax not only has better performances of lubrication, filtration loss control property, heat resistance, and tolerance to salt and is environmentally friendly, but also can solve the problems of freezing in the winter and poor storage stability of liquid wax emulsion in oilfield applications.

  17. MIXTA-like transcription factors and WAX INDUCER1/SHINE1 coordinately regulate cuticle development in Arabidopsis and Torenia fournieri. (United States)

    Oshima, Yoshimi; Shikata, Masahito; Koyama, Tomotsugu; Ohtsubo, Norihiro; Mitsuda, Nobutaka; Ohme-Takagi, Masaru


    The waxy plant cuticle protects cells from dehydration, repels pathogen attack, and prevents organ fusion during development. The transcription factor WAX INDUCER1/SHINE1 (WIN1/SHN1) regulates the biosynthesis of waxy substances in Arabidopsis thaliana. Here, we show that the MIXTA-like MYB transcription factors MYB106 and MYB16, which regulate epidermal cell morphology, also regulate cuticle development coordinately with WIN1/SHN1 in Arabidopsis and Torenia fournieri. Expression of a MYB106 chimeric repressor fusion (35S:MYB106-SRDX) and knockout/down of MYB106 and MYB16 induced cuticle deficiencies characterized by organ adhesion and reduction of epicuticular wax crystals and cutin nanoridges. A similar organ fusion phenotype was produced by expression of a WIN1/SHN1 chimeric repressor. Conversely, the dominant active form of MYB106 (35S:MYB106-VP16) induced ectopic production of cutin nanoridges and increased expression of WIN1/SHN1 and wax biosynthetic genes. Microarray experiments revealed that MYB106 and WIN1/SHN1 regulate similar sets of genes, predominantly those involved in wax and cutin biosynthesis. Furthermore, WIN1/SHN1 expression was induced by MYB106-VP16 and repressed by MYB106-SRDX. These results indicate that the regulatory cascade of MIXTA-like proteins and WIN1/SHN1 coordinately regulate cutin biosynthesis and wax accumulation. This study reveals an additional key aspect of MIXTA-like protein function and suggests a unique relationship between cuticle development and epidermal cell differentiation.

  18. Synchrotron WAXS and XANES studies of silica (SiO2) powders synthesized from Indonesian natural sands (United States)

    Muchlis, Khairanissa; Aini Fauziyah, Nur; Soontaranon, Siriwat; Limpirat, Wanwisa; Pratapa, Suminar


    In this study, we have investigated polymorphic silica (SiO2) powders using, Wide Angle X-ray Scattering (WAXS) and X-Ray Absorption Near Edge Spectroscopy (XANES), laboratory X-Ray Diffraction (XRD) instruments. The WAXS and XANES spectra were collected using synchrotron radiation at Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima, Thailand. The silica powders were obtained by processing silica sand from Tanah Laut, South Kalimantan, Indonesia. Purification process of silica sand was done by magnetic separation and immersion with HCl. The purification step was needed to reduce impurity or undesirable non Si elements. Three polymorphs of silica were produced, i.e. amorphous phase (A), quartz (B), and cristobalite (C). WAXS profile for each phase was presented in terms of intensity vs. 2θ prior to analyses. Both XRD (λCuKα=1.54056 Å) and WAXS (λ=1.09 Å) patttern show that (1) A sample contains no crystallites, (2) B sample is monophasic, contains only quartz, and (3) C sample contains cristobalite and trydimite. XRD quantitative analysis using Rietica gave 98,8 wt% cristobalite, while the associated WAXS data provided 98.7 wt% cristobalite. Si K-edge XANES spectra were measured at energy range 1840 to 1920 eV. Qualitatively, the pre-edge and edge features for all phases are similar, but their main peaks in the post-edge region are different.

  19. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology (United States)


    Background Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil) and vegetables (jojoba) which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Results Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C), the enzyme concentration (33.34-300 IU/mL), the alcohol/palm stearin molar ratio (3-7 mol/mol) and the substrate concentration (0.06-0.34 g/mL) on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL) a high conversion yield of 98.52% was reached within a reaction time of 2 h. Conclusions Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters. PMID:21682865

  20. Transient silencing of the KASII genes is feasible in Nicotiana benthamiana for metabolic engineering of wax ester composition. (United States)

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


    The beta-ketoacyl-ACP synthase II (KASII) is an enzyme in fatty acid biosynthesis, catalyzing the elongation of 16:0-acyl carrier protein (ACP) to 18:0-ACP in plastids. Mutations in KASII genes in higher plants can lead to lethality, which makes it difficult to utilize the gene for lipid metabolic engineering. We demonstrated previously that transient expression of plastid-directed fatty acyl reductases and wax ester synthases could result in different compositions of wax esters. We hypothesized that changing the ratio between C16 (palmitoyl-compounds) and C18 (stearoyl-compounds) in the plastidic acyl-ACP pool by inhibition of KASII expression would change the yield and composition of wax esters via substrate preference of the introduced enzymes. Here, we report that transient inhibition of KASII expression by three different RNAi constructs in leaves of N. benthamiana results in almost complete inhibition of KASII expression. The transient RNAi approach led to a shift of carbon flux from a pool of C18 fatty acids to C16, which significantly increased wax ester production in AtFAR6-containing combinations. The results demonstrate that transient inhibition of KASII in vegetative tissues of higher plants enables metabolic studies towards industrial production of lipids such as wax esters with specific quality and composition.

  1. Current Situation of Research and Development of Emulsifying Wax%乳化蜡的研究开发现状

    Institute of Scientific and Technical Information of China (English)



    石蜡乳化得到的蜡乳液(又称乳化蜡)用途十分广泛.介绍了乳化蜡在国内外的研究以及发展状况,并陈述了目前各行各业根据乳化蜡的优点对其进行的广泛应用情况.综述了制备乳化蜡过程中对乳化蜡性质产生影响的因素—乳化剂的选择、乳化温度、乳化时间、乳化水、搅拌方式和搅拌速率及稳定剂对其性质的影响情况,并通过特种蜡和石蜡的性质比较,对特种蜡乳液的生产以及应用做了展望.%Paraffin emulsion (also known as emulsifying wax) had wide applications. Both the research and development of emulsifying wax at home and abroad was introduced, as well as the extensive applications in every field according to its advantages. The effects of emulsifier, tempera ture, time, emulsifying water, stirring speed and way, and the stabilizer on the properties of emulsifying wax were summarized. By the properties com parison between special wax and paraffin, the production and application of special wax emulsion was prospected.

  2. Batik printing of cotton fabric with wax%蜡印带蜡印花工艺

    Institute of Scientific and Technical Information of China (English)



    Batik printing process on faric with wax is introduced. Aiming at the problems in present process, the key points of pretreating, wax printing and requirements, embossing, main-tone dyeing, wax cracking and caustic washing, stentering and drying, dye selection and fixing process are expounded. Effects of pretreatment, wax printing, wax softening point choosing, reactive dye selection, washing and dewaxing on printing quality are analyzed. The prevention measures and solutions are given.%针对带蜡印花工艺存在的问题,系统阐述了带蜡印花的前处理、印蜡、用蜡要求、压花、染主色调、甩蜡碱洗、拉幅烘干、印花染料筛选和固色工艺等工艺要点;分析了影响前处理、印蜡、用蜡软化点的选择及活性染料选用和水洗退蜡等方面质量的因素,并给出预防和解决措施.

  3. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Gargouri Youssef


    Full Text Available Abstract Background Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil and vegetables (jojoba which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Results Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C, the enzyme concentration (33.34-300 IU/mL, the alcohol/palm stearin molar ratio (3-7 mol/mol and the substrate concentration (0.06-0.34 g/mL on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL a high conversion yield of 98.52% was reached within a reaction time of 2 h. Conclusions Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters.

  4. The molecular signatures of Taxodiaceae / Cupressaceae / Taxaceae (TCT) leaf waxes in modern and ancient samples (United States)

    Ho, M.; Zinniker, D.; Green Nylen, N.; Moldowan, J. M.; Denisevich, P.


    Members of the Taxodiaceae/Cupressaceae/Taxaceae (TCT) complex of conifers originated sometime before the late Jurassic. Since that time the group has diverged to fill diverse ecological niches in desert, marsh, tundra, alpine, and coastal habitats and a variety of forest types. 175 species from 35 genera are now found across 6 continents. The aims of this research project are 1) to analyze and describe cuticular isoprenoid and acetogenic lipids from a diverse group of living members of the TCT complex and 2) to begin a search for these compounds and their diagenetic products in geological samples with known contributions from ancient TCT members. Hexane extracts of several hundred modern conifer specimens from more than 25 genera were studied in an attempt to find phylogenetic trends in the distribution and abundance of wax components. Diverse skeletal types of bicyclic, tricyclic, and tetracyclic diterpenes were found throughout the TCT complex. These compounds were found to have the highest absolute and relative abundance in several temperate rainforest and marsh endemics and the lowest relative abundance in desert adapted species. Large scale phylogenetic patterns in the distribution of individual diterpenes were not evident. Some species showed little intraspecific variation in diterpenes, while others showed considerable variability in diterpene products from one tree to another. The waxes of many members of the TCT complex are dominated by uniquely long-chain normal alkanes, with peak abundance at 33 and/or 35 carbons. This character is found within a phylogenetically distinct group of TCT -- including the genera Austrocedrus, Callitris, Calocedrus, Chamaecyparis, Cryptomeria, Cupressus, Diselma, Fitzroya, Juniperus, Libocedrus, Platycladus, Taxodium, Tetraclinis, Thuja, and Thujopsis -- and is seen in plants from extremely different habitats. We postulate that this group within the TCT complex shares a conserved very long chain fatty acid (VLCFA) elongase

  5. Non-targeted chromatographic analyses of cuticular wax flavonoids from Physalis alkekengi L. (United States)

    Kranjc, Eva; Albreht, Alen; Vovk, Irena; Makuc, Damjan; Plavec, Janez


    Since Chinese lantern (Physalis alkekengi L.) represents a rich source of various bioactive secondary metabolites, there is an urge for its detailed characterization. Non-polar flavonoid aglycones represent one of the few bioactive species found in plant's cuticular waxes. The separation of flavonoids is already extensively covered in the literature, but methods dedicated to separation and identification of methylated flavonoids are rather scarce. In the present study a non-targeted approach for the separation, isolation and identification of methylated flavonoids present in P. alkekengi L. var. franchetii cuticular waxes was established. A rapid and simple separation on HPTLC silica gel was developed for preliminary screening of flavonoids. Fast HPLC-UV-MS(n) and HPLC-UV methods using a C6-Phenyl and a C18 stationary phase were also developed, respectively. In both cases, the right combination of temperature and tetrahydrofuran, as a mobile phase modifier, were shown to be crucial for a baseline separation of all studied compounds. By employing a semi-preparative analog of the C18 column, a simultaneous isolation of pure unknown analytes was achieved. Using these developed methods in combination with NMR, four 3-O-methylated flavonols were detected and identified in P. alkekengi L. var. franchetii cuticular waxes: myricetin 3,7,3'-trimethyl ether, quercetin 3,7-dimethyl ether, myricetin 3,7,3',5'-tetramethyl ether and quercetin 3,7,3'-trimethyl ether. Moreover, the simple and fast isocratic HPLC-UV-MS(n) method (under 8min) should prove useful in quality control of P. alkekengi L. var. franchetii by enabling chromatographic fingerprinting of external methylated flavonols. Finally, a rationale for the mechanism of separation of these metabolites by HPLC is also given, which establishes a foundation for future development of chromatographic methods for methylated flavonols and related compounds.

  6. Developing wax-based granule formulations for mating disruption of oriental beetles (Coleoptera: Scarabaeidae) in turfgrass. (United States)

    Behle, R W; Cossé, A A; Dunlap, C; Fisher, J; Koppenhöfer, A M


    Oriental beetle, Anomala orientalis Waterhouse (Coleoptera: Scarabaeidae), is a pest of turfgrass that may be controlled by applications of synthetic pheromone (Z)-/ (E)-7-tetradecen-2-one to disrupt mating. Laboratory experiments were conducted to determine release profiles of pheromone from experimental wax-based granules, a proprietary wax granule, and rubber septa commonly used in pheromone traps. Rubber septa loaded with 10, 100, and 300 microg per septum provided steady rates of pheromone release (zero-order) over 4 wk of laboratory evaluation (total = 1.1, 9.0, and 26.9 microg/4 wk, respectively). Septa with 1,000 microg per septum had a significant decline in the rate of pheromone release for this 4-wk exposure time (total = 119 microg/4 wk). A large proprietary wax granule (44 mg per granule, 25% wt:wt pheromone) provided a steady rate of pheromone release (total = 2,347 microg/4 wk per granule). Experimental granules (16 mg per granule) made of soywax with higher pheromone loads (10% wt:wt) approached zero-order release (steady state) (total = 69 microg/4 wk per granule), whereas smaller granules (4 mg per granule) with less pheromone (0.1% wt:wt) provided first-order release profiles (decreasing rate with longer exposure time) (total = 0.35 microg/4 wk per granule). A field trial in turfgrass demonstrated the potential of selected granular formulations to provide effective mating disruption for up to 4 wk, as measured by pheromone trap shutdown. Documenting pheromone release profiles for these experimental granules and rubber septa provides valuable information that will support future field evaluations of mating disruption as a control strategy.

  7. Experimental Parameters for Wax Modeling of the Deccan Traps Flood Basalt Province (United States)

    Rader, E. L.; Vanderkluysen, L.; Clarke, A. B.


    The Deccan Traps consist of ~1,000,000 km3 of predominantly tholeiitic basaltic lava flows, which cover the western Indian subcontinent. Their eruption occurred over a ~1-3 million year period overlapping with the Cretaceous-Paleogene (K-Pg) boundary and, hence, has been implicated in one of the most significant extinction events in the history of the planet. The extent of environmental impacts caused by flood basalt eruptions is thought to be related, in part, to the amount, species, and timescales of volcanic gases released. Therefore, constraining the effusion rate of Deccan Traps lava flows is fundamental to understanding the K-Pg extinction event. Previous field and experimental work with polyethylene glycol (PEG) wax has shown that effusion rate is a primary factor controlling flow morphology. While sinuous flows and lava domes have been successfully recreated with PEG wax, the two most common morphologies seen in the Deccan Traps (compound and inflated sheet lobes) have not. We used heated PEG-400 wax injected into a tank of chilled water with a peristaltic pump to form experimental eruptions with high flow rate and low viscosity to replicate inflated flow lobes, and low flow rate with higher viscosity for compound flows. Unlike previous experiments, flow rate was varied during a single experiment to examine the effect on flow morphology. The Psi value is used as a scaling parameter to estimate effusion rates for compound and 'simple' inflated flows in the Deccan Traps. When combined with field work for volume estimates of the two flow types, these experiments will provide the best constraint on eruption rates to date.

  8. Non-Invasive Delivery of dsRNA into De-Waxed Tick Eggs by Electroporation (United States)

    Ruiz, Newton; de Abreu, Leonardo Araujo; Parizi, Luís Fernando; Kim, Tae Kwon; Mulenga, Albert; Braz, Gloria Regina Cardoso; Vaz, Itabajara da Silva; Logullo, Carlos


    RNA interference-mediated gene silencing was shown to be an efficient tool for validation of targets that may become anti-tick vaccine components. Here, we demonstrate the application of this approach in the validation of components of molecular signaling cascades, such as the Protein Kinase B (AKT) / Glycogen Synthase Kinase (GSK) axis during tick embryogenesis. It was shown that heptane and hypochlorite treatment of tick eggs can remove wax, affecting corium integrity and but not embryo development. Evidence of AKT and GSK dsRNA delivery into de-waxed eggs of via electroporation is provided. Primers designed to amplify part of the dsRNA delivered into the electroporated eggs dsRNA confirmed its entry in eggs. In addition, it was shown that electroporation is able to deliver the fluorescent stain, 4',6-diamidino-2-phenylindole (DAPI). To confirm gene silencing, a second set of primers was designed outside the dsRNA sequence of target gene. In this assay, the suppression of AKT and GSK transcripts (approximately 50% reduction in both genes) was demonstrated in 7-day-old eggs. Interestingly, silencing of GSK in 7-day-old eggs caused 25% reduction in hatching. Additionally, the effect of silencing AKT and GSK on embryo energy metabolism was evaluated. As expected, knockdown of AKT, which down regulates GSK, the suppressor of glycogen synthesis, decreased glycogen content in electroporated eggs. These data demonstrate that electroporation of de-waxed R. microplus eggs could be used for gene silencing in tick embryos, and improve the knowledge about arthropod embryogenesis. PMID:26091260

  9. RNA-Seq reveals leaf cuticular wax-related genes in Welsh onion.

    Directory of Open Access Journals (Sweden)

    Qianchun Liu

    Full Text Available The waxy cuticle plays a very important role in plant resistance to various biotic and abiotic stresses and is an important characteristic of Welsh onions. Two different types of biangan Welsh onions (BG were selected for this study: BG, a wild-type covered by wax, which forms a continuous lipid membrane on its epidermal cells, and GLBG, a glossy mutant of BG whose epidermal cells are not covered by wax. To elucidate the waxy cuticle-related gene expression changes, we used RNA-Seq to compare these two Welsh onion varieties with distinct differences in cuticular wax. The de novo assembly yielded 42,881 putative unigenes, 25.41% of which are longer than 1,000 bp. Among the high-quality unique sequences, 22,289 (52.0% had at least one significant match to an existing gene model. A total of 798 genes, representing 1.86% of the total putative unigenes, were differentially expressed between these two Welsh onion varieties. The expression patterns of four important unigenes that are related to waxy cuticle biosynthesis were confirmed by RT-qPCR and COG class annotation, which demonstrated that these genes play an important role in defense mechanisms and lipid transport and metabolism. To our knowledge, this study is the first exploration of the Welsh onion waxy cuticle. These results may help to reveal the molecular mechanisms underlying the waxy cuticle and will be useful for waxy gene cloning, genetics and breeding as well as phylogenetic and evolutionary studies of the Welsh onion.

  10. Crystal structure and elastic constants of Dharwar cotton fibre using WAXS data

    Indian Academy of Sciences (India)

    O M Samir; R Somashekar


    Wide-angle X-ray scattering (WAXS) recordings were carried out on raw Dharwar cotton fibres available in Karnataka. Using this data and employing linked atom least squares (LALS) method, we report here the molecular and crystal structure of these cotton fibres. Employing structural data, we have computed elastic moduli tensor components of these fibres. From these investigations, it turns out that the intrinsic strains present in the fibre arise due to hydrogen bonds and not covalent bonds, which is a significant result.

  11. Bee Wax Propolis Extract as Eco-Friendly Corrosion Inhibitors for 304SS in Sulfuric Acid


    Femiana Gapsari; Rudy Soenoko; Agus Suprapto; Wahyono Suprapto


    The inhibition properties of bee wax propolis (BWP) extract on the 304SS in 0.5 M sulfuric acid were conducted using potentiodynamic polarization, EIS, and XRD. Quercetin (2-(3.4-dihydroxy phenyl)-3.5.7-trihydroxy-4H-chromen-4-one) was identified as the main compound in the BWP extract based on FTIR and HPLC analysis. The results showed that the inhibitor could retard the corrosion rate of 304SS in 0.5 M sulfuric acid which reached 97.29% and 91.42% at 2000 ppm based on potentiodynamic polari...

  12. Co-metabolism of DDT by the newly isolated bacterium, Pseudoxanthomonas sp. wax



    Microbial degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) is the most promising way to clean up DDT residues found in the environment. In this paper, a bacterium designated as wax, which was capable of co-metabolizing DDT with other carbon sources, was isolated from a long-term DDT-contaminated soil sample by an enrichment culture technique. The new isolate was identified as a member of the Pseudoxanthomonas sp., based on its morphological, physiological and biochemical pro...

  13. Evaluation of experimental data for wax and diamondoids solubility in gaseous systems

    DEFF Research Database (Denmark)

    Mohammadi, Amir H.; Gharagheizi, Farhad; Eslamimanesh, Ali


    The Leverage statistical approach is herein applied for evaluation of experimental data of the paraffin waxes/diamondoids solubility in gaseous systems. The calculation steps of this algorithm consist of determination of the statistical Hat matrix, sketching the Williams Plot, and calculation...... of the residuals of two selected correlations results. In addition, the applicability domains of the investigated correlations and quality of the existing experimental data are examined accompanied by outlier diagnostics. Two previously applied Chrastil-type correlations including the original Chrastil and Mèndez...... of the corresponding solubilities are statistically valid and correct, and none of the experimental data can be designated as outliers....

  14. Low severity upgrading of F-T waxes with solid superacids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wender, I.; Tierney, J.W.


    The use of solid acids, especially Pt/ZrO{sub 2}/SO{sub 4}, to convert long chain alkanes and Fischer-Tropsch waxes to liquid fuels under mild reaction conditions was explored in this work. Anion and/or hydrogenation metal modified zirconium oxides were synthesized, characterized, and tested for hydrocracking and hydroisomerization. of model compounds, chiefly with n-hexadecane. The relationship between catalytic activity and acidic character of the bifunctional Pt/ZrO{sub 2}/SO{sub 4} catalyst was investigated.

  15. Patchable, flexible heat-sensing hybrid ionic gate nanochannel modified with a wax-composite (United States)

    Chun, Kyoung-Yong; Choi, Wook; Roh, Sung-Cheoul; Han, Chang-Soo


    Heat-driven ionic gate nanochannels have been recently demonstrated, which exploit temperature-responsive polymer brushes based on wettability. These heat-sensing artificial nanochannels operate in a broad temperature-response boundary and fixed liquid cell environment, thereby experiencing limited system operation in the flat and solid state. Here we have developed a patchable and flexible heat-sensing artificial ionic gate nanochannel, which can operate in the range of the human body temperature. A wax-elastic copolymer, coated onto a commercial nanopore membrane by a controlled-vacuum filtration method, was used for the construction of temperature-responsive nanopores. The robust and flexible nanochannel heat sensor, which is combined with an agarose gel electrolyte, can sustain reversible thermo-responsive ionic gating based on the volumetric work of the wax-composite layers in a selective temperature range. The ionic current is also effectively distinguished in the patchable bandage-type nanochannel for human heat-sensing.Heat-driven ionic gate nanochannels have been recently demonstrated, which exploit temperature-responsive polymer brushes based on wettability. These heat-sensing artificial nanochannels operate in a broad temperature-response boundary and fixed liquid cell environment, thereby experiencing limited system operation in the flat and solid state. Here we have developed a patchable and flexible heat-sensing artificial ionic gate nanochannel, which can operate in the range of the human body temperature. A wax-elastic copolymer, coated onto a commercial nanopore membrane by a controlled-vacuum filtration method, was used for the construction of temperature-responsive nanopores. The robust and flexible nanochannel heat sensor, which is combined with an agarose gel electrolyte, can sustain reversible thermo-responsive ionic gating based on the volumetric work of the wax-composite layers in a selective temperature range. The ionic current is also

  16. Hydrogen isotope composition of leaf wax n-alkanes in Arabidopsis lines with different transpiration rates (United States)

    Pedentchouk, N.; Lawson, T.; Eley, Y.; McAusland, L.


    Stable isotopic compositions of oxygen and hydrogen are used widely to investigate modern and ancient water cycles. The D/H composition of organic compounds derived from terrestrial plants has recently attracted significant attention as a proxy for palaeohydrology. However, the role of various plant physiological and biochemical factors in controlling the D/H signature of leaf wax lipids in extant plants remains unclear. The focus of this study is to investigate the effect of plant transpiration on the D/H composition of n-alkanes in terrestrial plants. This experiment includes 4 varieties of Arabidopsis thaliana that differ with respect to stomatal density and stomatal geometry. All 4 varieties were grown indoors under identical temperature, relative humidity, light and watering regimes and then sampled for leaf wax and leaf water stable isotopic measurements. During growth, stomatal conductance to carbon dioxide and water vapour were also determined. We found that the plants varied significantly in terms of their transpiration rates. Transpiration rates were significantly higher in Arabidopsis ost1 and ost1-1 varieties (2.4 and 3.2 mmol m-2 s-1, respectively) than in Arabidopsis RbohD and Col-0 (1.5 and 1.4). However, hydrogen isotope measurements of n-alkanes extracted from leaf waxes revealed a very different pattern. Varieties ost1, ost1-1, and RbohD have very similar deltaD values of n-C29 alkane (-125, -128, and -127 per mil), whereas the deltaD value of Col-0 is more negative (-137 per mil). The initial results of this work suggest that plant transpiration is decoupled from the D/H composition of n-alkanes. In other words, physical processes that affect water vapour movement between the plant and its environment apparently cannot account for the stable hydrogen isotope composition of organic compounds that comprise leaf waxes. Additional, perhaps biochemical, processes that affect hydrogen isotope fractionation during photosynthesis might need to be invoked

  17. Antimicrobial activity of wax and hexane extracts from Citrus spp. peels

    Directory of Open Access Journals (Sweden)

    Susana Johann


    Full Text Available Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp., two human pathogens (Trichophyton mentagrophytes and Microsporum canis, and two opportunistic bacteria (Escherichia coli and Staphylococcus aureus. Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from peel extracts, which presented antimicrobial activity especially against M. canis and T. mentagrophytes: 4',5,6,7,8-pentamethoxyflavone (tangeritin and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin from C. reticulata; and 6,7-dimethoxycoumarin (also known as escoparone, scoparone or scoparin from C. limon.

  18. Investigation of some solvents for asphalten-wax-paraffin depositions formed on the oil refinery equipment

    Directory of Open Access Journals (Sweden)

    О. В. Тертишна


    Full Text Available Тhe methods of asphalten - wax- paraffin depositions removal from the oil refinery equipment were studied. The effectiveness of solvents were estimated by mass losses of samples wrapped up in filter paper after exposition in different reagents, such as once-run petrol, benzene, toluene, hexane and some mixtures of these substances. The best results were obtained in the hexane - benzene mixture with volume ratio 1:1. The maximal level of dissolution was achieved at 30-35 °С

  19. Antimicrobial activity of wax and hexane extracts from Citrus spp. peels. (United States)

    Johann, Susana; Oliveira, Vetúria Lopes de; Pizzolatti, Moacir G; Schripsema, Jan; Braz-Filho, Raimundo; Branco, Alexsandro; Smânia Jr, Artur


    Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp.), two human pathogens (Trichophyton mentagrophytes and Microsporum canis), and two opportunistic bacteria (Escherichia coli and Staphylococcus aureus). Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from peel extracts, which presented antimicrobial activity especially against M. canis and T. mentagrophytes: 4',5,6,7,8-pentamethoxyflavone (tangeritin) and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) from C. reticulata; and 6,7-dimethoxycoumarin (also known as escoparone, scoparone or scoparin) from C. limon.

  20. Toxin-binding proteins isolated from yellow mealworm Tenebrio molitor and wax moth Galleria mellonella. (United States)

    Bulushova, N V; Zhuzhikov, D P; Lyutikova, L I; Kirillova, N E; Zalunin, I A; Chestukhina, G G


    A 67-kDa protein that can specifically bind the activated Cry9A endotoxin under ligand-blotting conditions was purified from midgut epithelium apical membranes of wax moth Galleria mellonella by affinity chromatography. N-Terminal amino acid sequencing enabled identification of this protein as aminopeptidase N. In similar experiments, 66- and 58-kDa proteins specific to endotoxin Cry3A were isolated from the midgut epithelium apical membranes of Tenebrio molitor larvae. Mass spectrometry showed close similarity of the 58-kDa protein to the Tenebrio molitor α-amylase.


    Institute of Scientific and Technical Information of China (English)

    QIAN Jinwen; QI Guorong; DING Xinzhe; YANG Shiling


    The compatibility of mixtures of polymeric pour point depressants, i.e. poly(ethylene-co-vinylacetate) (EVA), poly(EVA-graft-octadecylacrylate) (EVA-g-POA), poly(ethylene-co-octadecylacrylate) (EOA) and poly(ethylene oxide-co-propylene oxide) (EO-co-PO) with wax or resin-asphaltene from crude oil have been studied by means of dilute-solution viscometry. It was found that each mixture pair is incompatible, but the degrees of incompatibility are quite different, which are in good agreement with the results from photomicrography.

  2. Experimental Study on Shear Fatigue Behavior and Stiffness Performance of Warm Mix Asphalt by adding Synthetic Wax

    CERN Document Server

    Petit, Christophe; Canestrari, Francesco; Pannunzio, Valter; Virgili, Amadeo


    Synthetic waxes produced by standard and registered processes may be used to manufacture Warm Mix Asphalt (WMA), which is a modified asphalt concrete produced, applied and compacted at temperatures below those typically required. This feature leads to environmental benefits, such as reduced energy consumption, gas and fume emissions, as well as to economic/operational advantages, such as lower production costs and greater hauling distances for extended construction seasons with tighter schedules. The present article serves to compare the mechanical performance of a WMA produced by adding synthetic wax with a traditional Hot Mix Asphalt (HMA) specimen, in terms of shear fatigue response and both complex and stiffness moduli. The experimental results and related modeling work demonstrate that adding synthetic wax into the WMA composition does not hinder either the destructive or non-destructive performance of an HMA, and this finding is corroborated by respectively measuring fatigue life and stiffness.

  3. 2D wax-printed paper substrates with extended solvent supply capabilities allow enhanced ion signal in paper spray ionization. (United States)

    Damon, Deidre E; Maher, Yosef S; Yin, Mengzhen; Jjunju, Fred P M; Young, Iain S; Taylor, Stephen; Maher, Simon; Badu-Tawiah, Abraham K


    Paper-based microfluidic channels were created from solid wax printing, and the resultant 2D wax-printed paper substrates were used for paper spray (PS) mass spectrometry (MS) analysis of small organic compounds. Controlling fluid flow at the tip of the wax-printed paper triangles enabled the use of lower spray voltages (0.5-1 kV) and extended signal lifetime (10 minutes) in PS-MS. High sensitivity (sub ng mL(-1) levels) and quantitation precision (capable of on-chip analyte detection by MS; such a device can replace the traditional complex laboratory procedures for MS analysis to enable on-site in situ sampling with portable mass spectrometers.

  4. Water Activated Graphene Oxide Transfer Using Wax Printed Membranes for Fast Patterning of a Touch Sensitive Device. (United States)

    Baptista-Pires, Luis; Mayorga-Martínez, Carmen C; Medina-Sánchez, Mariana; Montón, Helena; Merkoçi, Arben


    We demonstrate a graphene oxide printing technology using wax printed membranes for the fast patterning and water activation transfer using pressure based mechanisms. The wax printed membranes have 50 μm resolution, longtime stability and infinite shaping capability. The use of these membranes complemented with the vacuum filtration of graphene oxide provides the control over the thickness. Our demonstration provides a solvent free methodology for printing graphene oxide devices in all shapes and all substrates using the roll-to-roll automatized mechanism present in the wax printing machine. Graphene oxide was transferred over a wide variety of substrates as textile or PET in between others. Finally, we developed a touch switch sensing device integrated in a LED electronic circuit.

  5. Treatment planning of adhesive additive rehabilitations: the progressive wax-up of the three-step technique. (United States)

    Vailati, Francesca; Carciofo, Sylvain


    A full-mouth rehabilitation should be correctly planned from the start by using a diagnostic wax-up to reduce the potential for remakes, increased chair time, and laboratory costs. However, determining the clinical validity of an extensive wax-up can be complicated for clinicians who lack the experience of full-mouth rehabilitations. The three-step technique is a simplified approach that has been developed to facilitate the clinician's task. By following this technique, the diagnostic wax-up is progressively developed to the final outcome through the interaction between patient, clinician, and laboratory technician. This article provides guidelines aimed at helping clinicians and laboratory technicians to become more proactive in the treatment planning of full-mouth rehabilitations, by starting from the three major parameters of incisal edge position, occlusal plane position, and the vertical dimension of occlusion.

  6. Leaf surface wax is a source of plant methane formation under UV radiation and in the presence of oxygen

    DEFF Research Database (Denmark)

    Bruhn, Dan; Mikkelsen, Teis Nørgaard; Rolsted, M. M. M.


    The terrestrial vegetation is a source of UV radiation-induced aerobic methane (CH4) release to the atmosphere. Hitherto pectin, a plant structural component, has been considered as the most likely precursor for this CH4 release. However, most of the leaf pectin is situated below the surface wax...... layer, and UV transmittance of the cuticle differs among plant species. In some species, the cuticle effectively absorbs and/or reflects UV radiation. Thus, pectin may not necessarily contribute substantially to the UV radiation-induced CH4 emission measured at surface level in all species. Here, we...... investigated the potential of the leaf surface wax itself as a source of UV radiationinduced leaf aerobic CH4 formation. Isolated leaf surface wax emitted CH4 at substantial rates in response to UV radiation. This discovery has implications for how the phenomenon should be scaled to global levels. In relation...

  7. Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Clemons, Craig; Holm, Jens K.;


    and a high concentration of hydrophobic waxes on its outer surface that may limit the pellet strength. The present work studies the impact of the lignin glass transition on the pelletizing properties of wheat straw. Furthermore, the effect of surface waxes on the pelletizing process and pellet strength...... are investigated by comparing wheat straw before and after organic solvent extraction. The lignin glass transition temperature for wheat straw and extracted wheat straw is determined by dynamic mechanical thermal analysis. At a moisture content of 8%, transitions are identified at 53°C and 63°C, respectively....... Pellets are pressed from wheat straw and straw where the waxes have been extracted from. Two pelletizing temperatures were chosen—one below and one above the glass transition temperature of lignin. The pellets compression strength, density, and fracture surface were compared to each other. Pellets pressed...

  8. Studies on the compressibility of wax matrix granules of acetaminophen and their admixtures with various tableting bases. (United States)

    Uhumwangho, M U; Okor, R S


    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.

  9. Wax and cutin mutants of Arabidopsis: Quantitative characterization of the cuticular transport barrier in relation to chemical composition. (United States)

    Sadler, Christina; Schroll, Bettina; Zeisler, Viktoria; Waßmann, Friedrich; Franke, Rochus; Schreiber, Lukas


    Using (14)C-labeled epoxiconazole as a tracer, cuticular permeability of Arabidopsis thaliana leaves was quantitatively measured in order to compare different wax and cutin mutants (wax2, cut1, cer5, att1, bdg, shn3 and shn1) to the corresponding wild types (Col-0 and Ws). Mutants were characterized by decreases or increases in wax and/or cutin amounts. Permeances [ms(-1)] of Arabidopsis cuticles either increased in the mutants compared to wild type or were not affected. Thus, genetic changes in wax and cutin biosynthesis in some of the investigated Arabidopsis mutants obviously impaired the coordinated cutin and wax deposition at the outer leaf epidermal cell wall. As a consequence, barrier properties of cuticles were significantly decreased. However, increasing cutin and wax amounts by genetic modifications, did not automatically lead to improved cuticular barrier properties. As an alternative approach to the radioactive transport assay, changes in chlorophyll fluorescence were monitored after foliar application of metribuzine, an herbicide inhibiting electron transport in chloroplasts. Since both, half-times of photosynthesis inhibition as well as times of complete inhibition, in fact correlated with (14)C-epoxiconazole permeances, different rates of decline of photosynthetic yield between mutants and wild type must be a function of foliar uptake of the herbicide across the cuticle. Thus, monitoring changes in chlorophyll fluorescence, instead of conducting radioactive transport assays, represents an easy-to-handle and fast alternative evaluating cuticular barrier properties of different genotypes. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner.

  10. Surfactant-free carnauba wax dispersion and its use for layer-by-layer assembled protective surface coatings on wood (United States)

    Lozhechnikova, Alina; Bellanger, Hervé; Michen, Benjamin; Burgert, Ingo; Österberg, Monika


    Protection from liquid water and UV radiation are equally important, and a sophisticated approach is needed when developing surface coatings that preserve the natural and well-appreciated aesthetic appearance of wood. In order to prevent degradation and prolong the service life of timber, a protective coating was assembled using carnauba wax particles and zinc oxide nanoparticles via layer-by-layer deposition in water. For this purpose, a facile sonication route was developed to produce aqueous wax dispersion without any surfactants or stabilizers. The suspension was stable above pH 4 due to the electrostatic repulsion between the negatively charged wax particles. The particle size could be controlled by the initial wax concentration with average particle sizes ranging from 260 to 360 nm for 1 and 10 g/L, respectively. The deposition of wax particles onto the surface of spruce wood introduced additional roughness to the wood surface at micron level, while zinc oxide provided nano roughness and UV-absorbing properties. In addition to making wood superhydrophobic, this novel multilayer coating enhanced the natural moisture buffering capability of spruce. Moreover, wood surfaces prepared in this fashion showed a significant reduction in color change after exposure to UV light. A degradation of the wax through photocatalytic activity of the ZnO particles was measured by FTIR, indicating that further studies are required to achieve long-term stability. Nevertheless, the developed coating showed a unique combination of superhydrophobicity and excellent moisture buffering ability and some UV protection, all achieved using an environmentally friendly coating process, which is beneficial to retain the natural appearance of wood and improve indoor air quality and comfort.

  11. Neutral lipid biosynthesis in engineered Escherichia coli: jojoba oil-like wax esters and fatty acid butyl esters. (United States)

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander


    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

  12. Biochemical characterization and substrate specificity of jojoba fatty acyl-CoA reductase and jojoba wax synthase. (United States)

    Miklaszewska, Magdalena; Banaś, Antoni


    Wax esters are used in industry for production of lubricants, pharmaceuticals and cosmetics. The only natural source of wax esters is jojoba oil. A much wider variety of industrial wax esters-containing oils can be generated through genetic engineering. Biotechnological production of tailor-made wax esters requires, however, a detailed substrate specificity of fatty acyl-CoA reductases (FAR) and wax synthases (WS), the two enzymes involved in wax esters synthesis. In this study we have successfully characterized the substrate specificity of jojoba FAR and jojoba WS. The genes encoding both enzymes were expressed heterologously in Saccharomyces cerevisiae and the activity of tested enzymes was confirmed by in vivo studies and in vitro assays using microsomal preparations from transgenic yeast. Jojoba FAR exhibited the highest in vitro activity toward 18:0-CoA followed by 20:1-CoA and 22:1-CoA. The activity toward other 11 tested acyl-CoAs was low or undetectable as with 18:2-CoA and 18:3-CoA. In assays characterizing jojoba WS combinations of 17 fatty alcohols with 14 acyl-CoAs were tested. The enzyme displayed the highest activity toward 14:0-CoA and 16:0-CoA in combination with C16-C20 alcohols as well as toward C18 acyl-CoAs in combination with C12-C16 alcohols. 20:1-CoA was efficiently utilized in combination with most of the tested alcohols.

  13. Comparative analysis of surface wax in mature fruits between Satsuma mandarin (Citrus unshiu) and 'Newhall' navel orange (Citrus sinensis) from the perspective of crystal morphology, chemical composition and key gene expression. (United States)

    Wang, Jinqiu; Hao, Haohao; Liu, Runsheng; Ma, Qiaoli; Xu, Juan; Chen, Feng; Cheng, Yunjiang; Deng, Xiuxin


    Surface wax of mature Satsuma mandarin (Citrus unshiu) and 'Newhall' navel orange (Citrus sinensis) was analysed by crystal morphology, chemical composition, and gene expression levels. The epicuticular and total waxes of both citrus cultivars were mostly composed of aldehydes, alkanes, fatty acids and primary alcohols. The epicuticular wax accounted for 80% of the total wax in the Newhall fruits and was higher than that in the Satsuma fruits. Scanning electron microscopy showed that larger and more wax platelets were deposited on the surface of Newhall fruits than on the Satsuma fruits. Moreover, the expression levels of genes involved in the wax formation were consistent with the biochemical and crystal morphological analyses. These diversities of fruit wax between the two cultivars may contribute to the differences of fruit postharvest storage properties, which can provide important information for the production of synthetic wax for citrus fruits. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. A comparison of the accuracy of patterns processed from an inlay casting wax, an auto-polymerized resin and a light-cured resin pattern material

    Directory of Open Access Journals (Sweden)

    Praveen Rajagopal


    Conclusion: The resin pattern materials studied, undergo a significantly less dimensional change than the inlay waxes on prolonged storage. They would possibly be a better alternative to inlay wax in situations requiring high precision or when delayed investment (more than 1 h of patterns can be expected.

  15. Alteration of Wax Ester Content and Composition in Euglena gracilis with Gene Silencing of 3-ketoacyl-CoA Thiolase Isozymes. (United States)

    Nakazawa, Masami; Andoh, Hiroko; Koyama, Keiichiro; Watanabe, Yomi; Nakai, Takeo; Ueda, Mitsuhiro; Sakamoto, Tatsuji; Inui, Hiroshi; Nakano, Yoshihisa; Miyatake, Kazutaka


    Euglena gracilis produces wax ester under hypoxic and anaerobic culture conditions with a net synthesis of ATP. In wax ester fermentation, fatty acids are synthesized by reversing beta-oxidation in mitochondria. A major species of wax ester produced by E. gracilis is myristyl myristate (14:0-14:0Alc). Because of its shorter carbon chain length with saturated compounds, biodiesel produced from E. gracilis wax ester may have good cold flow properties with high oxidative stability. We reasoned that a slight metabolic modification would enable E. gracilis to produce a biofuel of ideal composition. In order to produce wax ester with shorter acyl chain length, we focused on isozymes of the enzyme 3-ketoacyl-CoA thiolase (KAT), a condensing enzyme of the mitochondrial fatty acid synthesis pathway in E. gracilis. We performed a gene silencing study of KAT isozymes in E. gracilis. Six KAT isozymes were identified in the E. gracilis EST database, and silencing any three of them (EgKAT1-3) altered the wax ester amount and composition. In particular, silencing EgKAT1 induced a significant compositional shift to shorter carbon chain lengths in wax ester. A model fuel mixture inferred from the composition of wax ester in EgKAT1-silenced cells showed a significant decrease in melting point compared to that of the control cells.

  16. Variability of wax ester fermentation in natural and bleached Euglena gracilis Strains in response to oxygen and the elongase inhibitor flufenacet. (United States)

    Tucci, Sara; Vacula, Rostislav; Krajcovic, Juraj; Proksch, Peter; Martin, William


    Euglena gracilis is able to synthesize adenosine triphosphate under anaerobic conditions through a malonyl-independent fatty acid synthesis leading to wax ester fermentation. Mitochondrial fatty acid synthesis uses acetyl-CoA and propionyl-CoA as C2- and C3-donors for de novo synthesis of even- and odd-numbered fatty acids, respectively. Euglena's wax ester fermentation has only been described in the E. gracilis strain 1224-5/25 Z. Here we investigate eight E. gracilis strains isolated in 1932-1958 from different localities in Europe and two bleached substrains of E. gracilis 1224-5/25, obtained by treatment with streptomycin and ofloxacin, and examine their anaerobic growth, wax ester fermentation, and wax ester composition. Under ambient oxygen levels, all strains accumulated wax esters in concentrations between 0.3% and 3.5% of the dry weight, but the strains revealed marked differences in wax ester accumulation with respect to anaerobic growth. Most fermenting strains tested showed increased wax ester synthesis under anaerobic conditions as well as the increased synthesis of odd-numbered fatty acids and alcohols suggesting an activation of the mitochondrial fatty acid biosynthesis pathway. Addition of the elongase inhibitor flufenacet to the growth medium specifically reduced the accumulation of odd-numbered fatty acids and alcohols and tended to increase the overall yield of anaerobic wax esters.

  17. Surfactant softening of plant leaf cuticle model wax--a Differential Scanning Calorimetry (DSC) and Quartz Crystal Microbalance with Dissipation (QCM-D) study. (United States)

    Fagerström, Anton; Kocherbitov, Vitaly; Westbye, Peter; Bergström, Karin; Arnebrant, Thomas; Engblom, Johan


    The aim was to quantify the softening effect that two surfactants (C10EO7 and C8G1.6) have on a plant leaf cuticle model wax. Effects on the thermotropic phase behavior and fluidity of the wax (C22H45OH/C32H66/H2O) were determined. The model wax is crystalline at ambient conditions, yet it is clearly softened by the surfactants. Both surfactants decreased the transition temperatures in the wax and the G″/G' ratio of the wax film increased in irreversible steps following surfactant exposure. C10EO7 has a stronger fluidizing effect than C8G1.6 due to stronger interaction with the hydrophobic waxes. Intracuticular waxes (IW) comprise both crystalline and amorphous domains and it has previously been proposed that the fluidizing effects of surfactants are due to interactions with the amorphous parts. New data suggests that this may be a simplification. Surfactants may also absorb in crevices between crystalline domains. This causes an irreversible effect and a softer cuticle wax.

  18. Solvent Effects on the Ultrastructure and Chemical Composition of Cuticular Wax and Its Potential Bioactive Role Against Alternaria alternata in Pingguoli Pear

    Institute of Scientific and Technical Information of China (English)

    CHEN Song-jiang; LI Yong-cai; BI Yang; YIN Yan; GE Yong-hong; WANG Yi


    Effects of different polarity solvents on the ultrastructure and chemical composition of cuticular wax in Pingguoli pear as well as their bioactive role against Alternaria alternate were studied and the results showed that the highest wax content was extracted with chloroform, and its wax content was up to 322.2 µg cm-2. Long-chain fatty acids predominated in menthol extracts and n-alkanes were predominant in wax extracted with ether, chloroform and n-hexane. Pingguoli pear fruit surface was covered by a smooth and amorphous wax layer with small, scattered crystal. The morphology of recrystallized wax in vitro after removal with different solvents was not similar to that of the intact fruit surface. Removal of cuticular wax with various solvents signiifcantly enhanced A. alternata infection, except for wax removed by methanol. The solvent extracts of methanol and chloroform stimulated the spore germination and mycelium growth of A. alternata, but the ether and n-hexane extracts showed antifungal activity.

  19. A novel mathematical model considering change of diffusion coefficient for predicting dissolution behavior of acetaminophen from wax matrix dosage form. (United States)

    Nitanai, Yuta; Agata, Yasuyoshi; Iwao, Yasunori; Itai, Shigeru


    From wax matrix dosage forms, drug and water-soluble polymer are released into the external solvent over time. As a consequence, the pore volume inside the wax matrix particles is increased and the diffusion coefficient of the drug is altered. In the present study, we attempted to derive a novel empirical mathematical model, namely, a time-dependent diffusivity (TDD) model, that assumes the change in the drug's diffusion coefficient can be used to predict the drug release from spherical wax matrix particles. Wax matrix particles were prepared by using acetaminophen (APAP), a model drug; glyceryl monostearate (GM), a wax base; and aminoalkyl methacrylate copolymer E (AMCE), a functional polymer that dissolves below pH 5.0 and swells over pH 5.0. A three-factor, three-level (3(3)) Box-Behnken design was used to evaluate the effects of several of the variables in the model formulation, and the release of APAP from wax matrix particles was evaluated by the paddle method at pH 4.0 and pH 6.5. When comparing the goodness of fit to the experimental data between the proposed TDD model and the conventional pure diffusion model, a better correspondence was observed for the TDD model in all cases. Multiple regression analysis revealed that an increase in AMCE loading enhanced the diffusion coefficient with time, and that this increase also had a significant effect on drug release behavior. Furthermore, from the results of the multiple regression analysis, a formulation with desired drug release behavior was found to satisfy the criteria of the bitter taste masking of APAP without lowering the bioavailability. That is to say, the amount of APAP released remains below 15% for 10 min at pH 6.5 and exceeds 90% within 30 min at pH 4.0. The predicted formulation was 15% APAP loading, 8.25% AMCE loading, and 400 μm mean particle diameter. When wax matrix dosage forms were prepared accordingly, the predicted drug release behavior agreed well with experimental values at each pH level

  20. Wax: A benign hydrogen-storage material that rapidly releases H2-rich gases through microwave-assisted catalytic decomposition. (United States)

    Gonzalez-Cortes, S; Slocombe, D R; Xiao, T; Aldawsari, A; Yao, B; Kuznetsov, V L; Liberti, E; Kirkland, A I; Alkinani, M S; Al-Megren, H A; Thomas, J M; Edwards, P P


    Hydrogen is often described as the fuel of the future, especially for application in hydrogen powered fuel-cell vehicles (HFCV's). However, its widespread implementation in this role has been thwarted by the lack of a lightweight, safe, on-board hydrogen storage material. Here we show that benign, readily-available hydrocarbon wax is capable of rapidly releasing large amounts of hydrogen through microwave-assisted catalytic decomposition. This discovery offers a new material and system for safe and efficient hydrogen storage and could facilitate its application in a HFCV. Importantly, hydrogen storage materials made of wax can be manufactured through completely sustainable processes utilizing biomass or other renewable feedstocks.

  1. To evaluate the efficacy of Mobilization Techniques in Post-Traumatic stiff ankle with and without Paraffin Wax Bath. (United States)

    Rashid, Sajid; Salick, Kamran; Kashif, Muhammah; Ahmad, Awad; Sarwar, Kashif


    Mobilization techniques are frequently used by physiotherapists to reduce pain, improve joint movement and facilitate return to activities after injury. The objective of this study was to explore differences in the efficacy of Mobilization Techniques in Post-Traumatic stiff ankle with and without Paraffin Wax Bath. Thirty seven patients of Post Traumatic stiff ankle were recruited for the study at Sajid Physiotherapy & Rehabilitation center, Multan from March 2011 to February 2013. It was a randomized controlled trial and the patients with equal grades of severity were placed in control and study groups. Group A had nineteen patients and Group B had 18 patients. The inclusion criteria were age range from 20-60 years, pain, loss of ROM, with history of trauma and fracture of ankle. The patients with similar complaints but with surgical treatment were excluded. Group A was given mobilization techniques with paraffin wax bath while group B was treated without paraffin wax bath. Improvement was observed by EscolaPaulista de Medicina Range of Motion (EPM-ROM) scale and visual analogue scale (VAS). After ten weeks of treatment, the patients were re-evaluated by an orthopedic surgeon and a Physiotherapist for their symptoms and ROM. t-test was applied to compare outcome between two groups and p movement showed improvement in inversion in group A (0.875 ± 0.276) vs. group B (0.966 ± 0.305) and in eversion in group A (0.948 ± 0.300) vs. group B (0.674 ± 0.213). Mobilization Techniques followed by wax bath resulted in significant improvements of range of motion (ROM), clinical and functional changes. Wax bath alone had no significant effect. After ten weeks intervention treatment, t-test was applied to compare outcome between the two groups and p=0.001to 0.004 in group A and p= 0.104 to 0.168 in group B, (pmobilization and wax bath therapy is an effective and beneficial tool to improve the symptoms and quality of life in post traumatic stiff ankle patients. Joint

  2. Determination of the n-alkane profile of epicuticular wax extracted from mature leaves of Cestrum nocturnum (Solanaceae: Solanales). (United States)

    Chowdhury, Nandita; Ghosh, Anupam; Bhattacharjee, Indranil; Laskar, Subrata; Chandra, Goutam


    An n-hexane extract of fresh, mature leaves of Cestrum nocturnum (Solanales: Solanaceae) containing thin layer epicuticular waxes was analysed by thin-layer chromatography, infrared and gas liquid chromatography using standard hydrocarbons. Seventeen long chain alkanes (n-C(18) to n-C(34)) were identified and quantified. Hentriacontane (n-C(31)) was established as the major n-alkane, while nonadecane (n-C(19)) was the least abundant component of the extracted wax fraction. The carbon preference index calculated for the sample was 1.30, showing an odd to even carbon number predominance.

  3. SAXS-WAXS studies of the low-resolution structure in solution of xylose/glucose isomerase from Streptomyces rubiginosus (United States)

    Kozak, Maciej; Taube, Michał


    The structure and conformation of molecule of xylose/glucose isomerase from Streptomyces rubiginosus in solution (at pH 6 and 7.6; with and without the substrate) has been studied by small- and wide-angle scattering of synchrotron radiation (SAXS-WAXS). On the basis of the SAXS-WAXS data, the low-resolution structure in solution has been reconstructed using ab inito methods. A comparison of the models of glucose isomerase shows only small differences between the model in solution and the crystal structure.

  4. Comparison of in vivo temperatures produced by hydrotherapy, paraffin wax treatment, and Fluidotherapy. (United States)

    Borrell, R M; Parker, R; Henley, E J; Masley, D; Repinecz, M


    The effectiveness of a new heat modality, Fluidotherapy, was compared with other superficial heat modalities by in vivo temperature measurements. The joint capsule and muscle temperatures in the hands and feet were measured in subjects treated with hydrotherapy, paraffin wax, and Fluidotherapy. Fluidotherapy is a dry heat modality consisting of finely divided solids suspended in an air stream. The dry heat modality, applied at 118 degrees F (47.78 degrees C), resulted in maximum joint capsule and muscle temperature rises of 16.2 degrees F (9 degrees C) and 9.5 degrees F (5.27 degrees C), respectively, compared to 13.5 degrees F (7.5 degrees C) and 8.1 degrees F (4.5 degrees C) for paraffin wax treatment and 10.8 degrees F (6.0 degrees C) and 7.7 degrees F (4.3 degrees C) for a 102 degrees F (38.89 degrees C) water bath, at a depth of about 0.5 cm beneath the skin. At depths down to 1.2 cm, superficial heat modalities are more effective than diathermy and much more effective than ultrasound in elevating temperature.


    Energy Technology Data Exchange (ETDEWEB)

    Patrick C. Joyce; Mark C. Thies


    The objective of this research project was 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}, is to be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300 C. Aspen Plus{trademark} was used to perform process simulation studies on the proposed extraction process, with Redlich-Kwong-Soave (RKS) being used for the thermodynamic property model. In summary, we have made comprehensive VLE measurements for short alkane + long alkane systems over a wide range of pressures and temperatures, dramatically increasing the amount of high-quality data available for these simple, yet highly relevant systems. In addition, our work has demonstrated that, surprisingly, no current thermodynamic model can adequately predict VLE behavior for these systems. Thus, process simulations (such as those for our proposed SCF extraction process) that incorporate these systems can currently only give results that are qualitative at best. Although significant progress has been made in the past decade, more experimental and theoretical work remain to be done before the phase equilibria of asymmetric alkane mixtures can be predicted with confidence.

  6. Fluorescent Molecular Rotor-in-Paraffin Waxes for Thermometry and Biometric Identification. (United States)

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


    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.

  7. Applicability of low-melting-point microcrystalline wax to develop temperature-sensitive formulations. (United States)

    Matsumoto, Kohei; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru


    Low-melting-point substances are widely used to develop temperature-sensitive formulations. In this study, we focused on microcrystalline wax (MCW) as a low-melting-point substance. We evaluated the drug release behavior of wax matrix (WM) particles using various MCW under various temperature conditions. WM particles containing acetaminophen were prepared using a spray congealing technique. In the dissolution test at 37°C, WM particles containing low-melting-point MCWs whose melting was starting at approx. 40°C (Hi-Mic-1045 or 1070) released the drug initially followed by the release of only a small amount. On the other hand, in the dissolution test at 20 and 25°C for WM particles containing Hi-Mic-1045 and at 20, 25, and 30°C for that containing Hi-Mic-1070, both WM particles showed faster drug release than at 37°C. The characteristic drug release suppression of WM particles containing low-melting-point MCWs at 37°C was thought attributable to MCW melting, as evidenced by differential scanning calorimetry analysis and powder X-ray diffraction analysis. Taken together, low-melting-point MCWs may be applicable to develop implantable temperature-sensitive formulations that drug release is accelerated by cooling at administered site. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Effects of formulation variables and characterization of guaifenesin wax microspheres for controlled release. (United States)

    Mani, Narasimhan; Park, M O; Jun, H W


    Sustained-release wax microspheres of guaifenesin, a highly water-soluble drug, were prepared by the hydrophobic congealable disperse method using a salting-out procedure. The effects of formulation variables on the loading efficiency, particle properties, and in-vitro drug release from the microspheres were determined. The type of dispersant, the amount of wetting agent, and initial stirring time used affected the loading efficiency, while the volume of external phase and emulsification speed affected the particle size of the microspheres to a greater extent. The crystal properties of the drug in the wax matrix and the morphology of the microspheres were studied by differential scanning calorimetry (DSC), powder x-ray diffraction (XRD), and scanning electron microscopy (SEM). The DSC thermograms of the microspheres showed that the drug lost its crystallinity during the microencapsulation process, which was further confirmed by the XRD data. The electron micrographs of the drug-loaded microspheres showed well-formed spherical particles with a rough exterior.

  9. 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


    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.

  10. Nanocomposite electrodes made of carbon nanofibers and black wax. Anodic stripping voltammetry of zinc and lead. (United States)

    van Dijk, N; Fletcher, S; Madden, C E; Marken, F


    Nanocomposite electrodes offer exciting new possibilities in electroanalytical chemistry. In this preliminary study, nanocomposite electrodes made of carbon nanofibers and black wax were characterized and investigated as novel substrates for metal deposition and stripping processes. Carbon nanofibers were grown from ethylene-hydrogen gas mixtures over Fe-Ni-Cu (85:10:5) nanoparticle catalysts at 600 degrees C and then embedded in Apiezon black wax under vacuum at 140 degrees C. The resulting nanocomposite electrodes showed (i) good conductivity, (ii) a wide potential window in aqueous solutions, (iii) low background currents, (iv) near steady state voltammetric responses with substantial Faradaic currents and (v) sharply peaked fast scan metal stripping responses. Zinc is a notoriously difficult metal to determine in aqueous solutions, because its deposition and stripping are accompanied by hydrogen evolution at extreme negative potentials. It therefore provided a challenging test for our new nanocomposite electrode. Although numerous complications associated with the hydrogen evolution process could not be eliminated, remarkably clear voltammograms could be obtained even at scan rates of 40 V s(-1).

  11. Soil and preen waxes influence the expression of carotenoid-based plumage coloration (United States)

    Surmacki, Adrian; Nowakowski, Jarosław K.


    The signaling function of carotenoid-based plumage is mainly determined by the concentration of pigments in feathers. For this reason, most studies of the proximate control of coloration focus on processes during and preceding moult. In great tits Parus major, past research demonstrates that carotenoid-based plumage coloration honestly indicates male quality and, thus, may be a sexually selected signal. In this study, we investigate how dirt and preen oil influence the coloration of carotenoid-based feathers in the great tit. We collected six feathers from each individual bird; three feathers served as controls while the remaining three feathers were washed with a chloroform/methanol mixture to remove soil and preen waxes. We assessed plumage coloration using digital photography. This cleaning procedure slightly enhanced ornamentation; the experimentally cleaned feathers expressed hues shifted towards shorter wavelengths and expressed brighter overall coloration than control feathers. This is the first experimental study conducted on wild birds demonstrating that, in addition to pigment concentration, the presence of preen waxes and soils on feathers may contribute to variation in coloration.

  12. Anti-inflammatory effects of jojoba liquid wax in experimental models. (United States)

    Habashy, Ramy R; Abdel-Naim, Ashraf B; Khalifa, Amani E; Al-Azizi, Mohammed M


    Jojoba [Simmondsia chinensis (Link 1822) Schneider 1907] is an arid perennial shrub grown in several American and African countries. Jojoba seeds, which are rich in liquid wax, were used in folk medicine for diverse ailments. In the current study, the potential anti-inflammatory activity of jojoba liquid wax (JLW) was evaluated in a number of experimental models. Results showed that JLW caused reduction of carrageenin-induced rat paw oedema in addition to diminishing prostaglandin E2 (PGE2) level in the inflammatory exudates. In a test for anti-inflammatory potential utilizing the chick's embryo chroioallantoic membrane (CAM), JLW also caused significant lowering of granulation tissue formation. Topical application of JLW reduced ear oedema induced by croton oil in rats. In the same animal model, JLW also reduced neutrophil infiltration, as indicated by decreased myeloperoxidase (MPO) activity. In addition, JLW ameliorated histopathological changes affected by croton oil application. In the lipopolysaccharide (LPS)-induced inflammation in air pouch in rats, JLW reduced nitric oxide (NO) level and tumor necrosis factor-alpha (TNF-alpha) release. In conclusion, this study demonstrates the effectiveness of JLW in combating inflammation in several experimental models. Further investigations are needed to identify the active constituents responsible for the anti-inflammatory property of JLW.

  13. Preparation Technology of Multifunctional Emulsifying Wax%多功能乳化蜡的制备

    Institute of Scientific and Technical Information of China (English)

    周大维; 王坤


    The formirig principle and prospect of market application have been introduced. The preparation technological conditions have been studied. The main factors are analyzed affecting the stability of wax emulsion,such as the types and dosage of emulsifying agents used, emulsifying temperature, mixing speed, emulsifying time,etc. The content of the complex emulsifying agent is 7% ,emulsifying temperature is 85℃, mixing speed is 1 000 r/rain, emulsifying 30 min, under such conditions, emulsifying wax with good stability and dispersibility can be got.%介绍了乳化蜡的形成原理以及市场应用前景,并研究了乳化蜡的制备工艺条件,其中乳化剂的种类及其用量、乳化温度、搅拌速度、乳化时间等是影响乳化蜡稳定性的主要因素.得出在选用复合乳化剂用量为7%,乳化温度为85℃,在1000r/min的搅拌速度下,乳化30 min,可以制备出稳定性以及分散性好的乳化蜡.

  14. The First 20 Hours of Geopolymerization: An in Situ WAXS Study of Flyash-Based Geopolymers

    Directory of Open Access Journals (Sweden)

    Ross P. Williams


    Full Text Available This study followed the first 20 h of flyash geopolymerization at 70 °C using time resolved Wide Angle X-ray Scattering (WAXS. The extent of dissolution of the amorphous phase of the flyash was determined to range from 29% to 54% for the different formulations trialed. The dissolution rate of the flyash significantly reduced after the first 5 h for all samples. During the formation stage of the geopolymer there were significant temporal variations in the chemistry of the dissolved solution due to the rate of flyash dissolution, with a relative standard deviation of 20%, 57% and 24% for the Si/Al, Na/Al and H/Si ratios, respectively. Utilizing the Power Law, scattering in the low angle region of the WAXS pattern combined with the geopolymer peak area yielded a measure which correlated with the compressive strength—providing a new method to measure the flyash dissolution and geopolymer formation processes independently. The evolution of several zeolite-like phases was followed, noting there are different formation mechanisms involved even within the same sample. Four samples were examined with compressive strengths ranging from 14(2–50(9 MPa, each was synthesized with flyash from Collie Power Station (Western Australia activated with sodium silicate solution of varying concentrations.

  15. Preparation and characterization of ketoprofen-loaded solid lipid nanoparticles made from beeswax and carnauba wax. (United States)

    Kheradmandnia, Soheila; Vasheghani-Farahani, Ebrahim; Nosrati, Mohsen; Atyabi, Fatemeh


    Solid lipid nanoparticles (SLNs) have been proposed as suitable colloidal carriers for delivery of drugs with limited solubility. Ketoprofen as a model drug was incorporated into SLNs prepared from a mixture of beeswax and carnauba wax using Tween 80 and egg lecithin as emulsifiers. The characteristics of the SLNs with various lipid and surfactant composition were investigated. The mean particle size of drug-loaded SLNs decreased upon mixing with Tween 80 and egg lecithin as well as upon increasing total surfactant concentration. SLNs of 75 ± 4 nm with a polydispersity index of 0.2 ± 0.02 were obtained using 1% (vol/vol) mixed surfactant at a ratio of 60:40 Tween 80 to egg lecithin. The zeta potential of these SLNs varied in the range of -15 to -17 (mV), suggesting the presence of similar interface properties. High drug entrapment efficiency of 97% revealed the ability of SLNs to incorporate a poorly water-soluble drug such as ketoprofen. Differential scanning calorimetry thermograms and high-performance liquid chromatographic analysis indicated the stability of nanoparticles with negligible drug leakage after 45 days of storage. It was also found that nanoparticles with more beeswax content in their core exhibited faster drug release as compared with those containing more carnauba wax in their structure.

  16. Epicuticular Wax in Developing Olives (Olea europaea) Is Highly Dependent upon Cultivar and Fruit Ripeness. (United States)

    Vichi, Stefania; Cortés-Francisco, Nuria; Caixach, Josep; Barrios, Gonçal; Mateu, Jordi; Ninot, Antonia; Romero, Agustí


    The epicuticular wax (EW) layer is located on the surface of most plant organs. It provides the cuticle with most of its properties and is the primary barrier against biotic and abiotic stress. Despite the importance of Olea europaea cultivation, few studies have characterized the EW covering leaves and olives, which could be involved in resistance to both infection and environmental conditions. In the present study, wide-ranging screening was carried out using direct-injection electrospray ionization coupled to high-resolution mass spectrometry to analyze EW in developing olives of nine varieties. The proportions of EW fractions [wax esters (WEs), diacylglycerols, triacylglycerols (TAGs), triterpenic acids, and aldehydes] strongly depended upon the olive cultivar and, in only a few cases, were influenced by the sampling date. The specific compositions of the major fractions, WEs and TAGs, were strictly related to the cultivar, while the degree of unsaturation and chain length of the WEs evolved throughout the 4 weeks prior to the olive turning color.

  17. Ear wax (United States)

    ... al, eds. Cummings Otolaryngology . 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 138. O'Handley JG, Tobin ... Textbook of Family Medicine . 9th ed. Philadelphia, PA: Elsevier; 2016:chap 18. Pfaff JA, Moore GP. Otolaryngology. ...

  18. Cooling of High-Power LED Lamp Using a Commercial Paraffin Wax (United States)

    Zmywaczyk, J.; Zbińkowski, P.; Smogór, H.; Olejnik, A.; Koniorczyk, P.


    Commercial paraffin wax used by Bolsius Nederland B.V. for manufacturing various kinds of candles was applied as a phase-change material (PCM) for cooling a 28 W high-power light emitting diode (LED) panel during its operation. The main problem arising during operation of an LED is thermal management. According to the manufacturer's datasheet specifications (BioSolution Ltd., the operating temperature range for the LED street lamp UL28W is (-30 {°}C) to (+40 {°}C). The object of the present study was an LED panel containing 28 pieces of high-power 1W LEDs connected in series (4 LEDs in each of the 7 rows) mounted on an aluminum plate of dimensions 80 mm by 135 mm. The tested aluminum plate was placed in a block made of aluminum with a hollow compartment containing Bolsius paraffin wax of density 914 kg\\cdot m^{-3} at room temperature. Temperatures were recorded using K-type thermocouples at selected locations of the tested LED panel for several values of the power supplied to it, while utilizing PCM and without it. As the manufacturer of Bolsius wax candles does not provide any data on the thermal properties of the material used, it was necessary to carry out micro-calorimetric research. Thermophysical properties of the paraffin wax such as the apparent specific heat, enthalpy of phase transition and temperature of phase change transition during heating and cooling were determined using the Netzsch DSC 214 Polyma. The Netzsch TG 209F3 Tarsus was used for TG/DTG measurements. DSC investigations revealed the following thermal transitions taking place during the first heating: solid-solid transition (onset 30.4 {°}C, peak at 40.9 {°}C), solid-liquid transition (onset 47.7 {°}C, peak at 54.9 {°}C, end at 58.3 {°}C), latent heat of energy storage 201 J\\cdot g^{-1}, apparent specific heat corresponding to peak at 41.5 {°}C (5.498 J\\cdot g^{-1}\\cdot K^{-1}). DTG investigations revealed that the decomposition of paraffin wax is a two

  19. Interaction of Plant Epicuticular Waxes and Extracellular Esterases of Curvularia eragrostidis during Infection of Digitaria sanguinalis and Festuca arundinacea by the Fungus

    Directory of Open Access Journals (Sweden)

    Lang-Lai Xu


    Full Text Available Curvularia eragrostidis, a causal agent of head blight on the weed (Digitariasanguinalis, did not cause disease on the turfgrass Festuca arundinacea. Differentextracellular esterase isoenzymes were detected in saprophytic and parasitic phases duringthe fungal germination. The epicuticular waxes of D. sanguinalis were more efficient toinduce the secretion of esterases from the fungus than that of F. arundinacea, but were morerapidly degraded by the fungal enzymes. Component analysis indicated that the epicuticularwaxes from D. sanguinalis were mostly composed of alcohols, with 54.3% being 9,12-Octadecadien-1-ol. The main component of F arundinacea waxes was alkyl compounds,with 49.8% being olefin, 9-Tricosence. More long-chained esters were found in D.sanguinalis waxes, which were easier to be digested than those in F. arundinacea waxes byextreacellular esterases of the fungus. Epicuticular waxes play a role in varyingpathogenicity of C. eragrostidis on D. sanguinalis and F arundinacea.

  20. Developmental Changes in Composition and Morphology of Cuticular Waxes on Leaves and Spikes of Glossy and Glaucous Wheat (Triticum aestivum L..

    Directory of Open Access Journals (Sweden)

    Yong Wang

    Full Text Available The glossy varieties (A14 and Jing 2001 and glaucous varieties (Fanmai 5 and Shanken 99 of wheat (Triticum aestivum L. were selected for evaluation of developmental changes in the composition and morphology of cuticular waxes on leaves and spikes. The results provide us with two different wax development patterns between leaf and spike. The general accumulation trend of the total wax load on leaf and spike surfaces is first to increase and then decrease during the development growth period, but these changes were caused by different compound classes between leaf and spike. Developmental changes of leaf waxes were mainly the result of variations in composition of alcohols and alkanes. In addition, diketones were the third important contributor to the leaf wax changes in the glaucous varieties. Alkanes and diketones were the two major compound classes that caused the developmental changes of spike waxes. For leaf waxes, β- and OH-β-diketones were first detected in flag leaves from 200-day-old plants, and the amounts of β- and OH-β-diketones were significantly higher in glaucous varieties compared with glossy varieties. In spike waxes, β-diketone existed in all varieties, but OH-β-diketone was detectable only in the glaucous varieties. Unexpectedly, the glaucous variety Fanmai 5 yielded large amounts of OH-β-diketone. There was a significant shift in the chain length distribution of alkanes between early stage leaf and flag leaf. Unlike C28 alcohol being the dominant chain length in leaf waxes, the dominant alcohol chain length of spikes was C24 or C26 depending on varieties. Epicuticular wax crystals on wheat leaf and glume were comprised of platelets and tubules, and the crystal morphology changed constantly throughout plant growth, especially the abaxial leaf crystals. Moreover, our results suggested that platelets and tubules on glume surfaces could be formed rapidly within a few days.

  1. Developmental Changes in Composition and Morphology of Cuticular Waxes on Leaves and Spikes of Glossy and Glaucous Wheat (Triticum aestivum L.). (United States)

    Wang, Yong; Wang, Jiahuan; Chai, Guaiqiang; Li, Chunlian; Hu, Yingang; Chen, Xinhong; Wang, Zhonghua


    The glossy varieties (A14 and Jing 2001) and glaucous varieties (Fanmai 5 and Shanken 99) of wheat (Triticum aestivum L.) were selected for evaluation of developmental changes in the composition and morphology of cuticular waxes on leaves and spikes. The results provide us with two different wax development patterns between leaf and spike. The general accumulation trend of the total wax load on leaf and spike surfaces is first to increase and then decrease during the development growth period, but these changes were caused by different compound classes between leaf and spike. Developmental changes of leaf waxes were mainly the result of variations in composition of alcohols and alkanes. In addition, diketones were the third important contributor to the leaf wax changes in the glaucous varieties. Alkanes and diketones were the two major compound classes that caused the developmental changes of spike waxes. For leaf waxes, β- and OH-β-diketones were first detected in flag leaves from 200-day-old plants, and the amounts of β- and OH-β-diketones were significantly higher in glaucous varieties compared with glossy varieties. In spike waxes, β-diketone existed in all varieties, but OH-β-diketone was detectable only in the glaucous varieties. Unexpectedly, the glaucous variety Fanmai 5 yielded large amounts of OH-β-diketone. There was a significant shift in the chain length distribution of alkanes between early stage leaf and flag leaf. Unlike C28 alcohol being the dominant chain length in leaf waxes, the dominant alcohol chain length of spikes was C24 or C26 depending on varieties. Epicuticular wax crystals on wheat leaf and glume were comprised of platelets and tubules, and the crystal morphology changed constantly throughout plant growth, especially the abaxial leaf crystals. Moreover, our results suggested that platelets and tubules on glume surfaces could be formed rapidly within a few days.

  2. Use of AmpliWax to optimize amplicon sterilization by isopsoralen. (United States)

    De la Viuda, M; Fille, M; Ruiz, J; Aslanzadeh, J


    The photochemical inactivation of amplicons by isopsoralen (IP-10) has been suggested as a possible means to prevent PCR carryover contamination. To evaluate the technique, serial dilutions of amplicons (10(11) to 10(3)) from the Borrelia burgdorferi OSP A gene were amplified in the presence of 0, 25, 50, and 100 micrograms of IP-10 per ml for 45 cycles. The PCR products were exposed to UV light for 15 min to activate IP-10 and sterilize the amplicons. One microliter of each sterilized sample was reamplified for an additional 45 cycles. The PCR products were then resolved in an agarose gel, blotted onto a nylon membrane, and probed with an alkaline phosphatase-conjugated chemiluminescent probe. Although IP-10 at concentrations of 50 and 100 micrograms/ml effectively sterilized up to 10(11) amplicons, the compound was inhibitory to PCR. IP-10 at a concentration of 25 micrograms/ml had slight inhibitory effect on PCR and did not completely sterilized all of the amplicons. Therefore, in subsequent experiments AmpliWax was substituted for mineral oil, and PCR was performed on 10(9) to 10(3) amplicons as described above. Following the amplification, the PCR tubes were cooled to solidify the AmpliWax and inoculated with various concentrations of IP-10. With this technique, PCR products produced from as many as 10(9) target amplicons were effectively sterilized with 200 micrograms of IP-10 per ml. Similarly, the addition of IP-10 (50 micrograms/ml) before and after PCR was evaluated for the detection of B. burgdorferi in 62 ticks from a region of Southern Connecticut where the organism is highly endemic. PCR performed in the presence of 50 micrograms of IP-10 per ml detected B. burgdorferi-specific DNA in 17 of 62 ticks (27%) following gel electrophoresis and in 34 of 62 ticks (55%) following Southern blot hybridization of the PCR products. In contrast, post-PCR addition of IP-10 detected borrelia-specific DNA in 31 of 62 ticks (50%) following gel electrophoresis and in

  3. Leaf water and plant wax hydrogen isotopes in a European sample network (United States)

    Nelson, D. B.; Kahmen, A.


    The hydrogen isotopic composition of plant waxes in sediments is now routinely used as a hydroclimate proxy. This application is based largely on empirical calibrations that have demonstrated continental-scale correlations between source water and lipid hydrogen isotope values. But at smaller spatial scales and for individual locations it is increasingly recognized that factors that modify apparent fractionation between source water and leaf lipid hydrogen isotope values must also be considered. Isotopic enrichment of leaf water during transpiration is key among these secondary factors, and is itself sensitive to changes in hydroclimate. Leaf water enrichment also occurs prior to photosynthetic water uptake, and is therefore independent from cellular-level biomarker synthesis. Recent advances in theory have permitted mechanistic models to be developed that can be used to predict the mean leaf water hydrogen and oxygen isotope composition from readily available meteorological variables. This permits global-scale isoscape maps of leaf water isotopic composition and enrichment above source water to be generated, but these models have not been widely validated at continental spatial scales. We have established a network of twenty-one sites across Europe where we are sampling for leaf-, xylem-, and soil-water isotopes (H and O) at approximately 5-week intervals over the summer growing season. We augment the sample set with weekly to monthly precipitation samples and early- and late-season plant wax lipid samples. Collaborators at each site are conducting the sampling, and most sites are members of the FLUXNET tower network that also record high-resolution meteorological data. We present information on the implementation of the network and preliminary results from the 2014 summer season. The complete dataset will be used to track the evolution of water isotopes from source to leaf water and from leaf water to lipid hydrogen across diverse environments. This will provide

  4. 石蜡乳液制备及性能研究%Preparation and property of paraffin wax emulsion

    Institute of Scientific and Technical Information of China (English)

    冯国琳; 刘有智; 焦纬洲; 于娜娜; 王笃政


    A paraffin wax emulsion was prepared with high speed dispersion mill as emulsifying equipment,58# technical grade refined paraffin wax as raw material. Factors on property of paraffin wax emulsion such as composition as well as HLB of emulsifier, dosage of emulsifier, emulsifying temperature, rotation speed and emulsifying time were investigated. The optimum emulsifying conditions for preparing paraffin wax emulsion were;using blended emulsifier (Span80,K12 and A) with HLB value of 11, dosage of emulsifier 7%, emulsifying temperature 85 °C , rotationl speed 2x2 800 r/min, emulsifying time 1 min.%以高速分散器为乳化设备,58#工业级全精炼石蜡为原料制备了石蜡乳液.考察了乳化剂的组成及其HLB值,乳化剂用量,乳化温度,转速和乳化时间等因素对石蜡乳液性能的影响.结果表明,适宜的乳化工艺条件为:以Span80,K12和助乳化剂A为复配乳化剂,其HLB值为11,乳化剂用量为7%,乳化温度为85℃,转速为2×2 800 r/min,乳化时间为1min.

  5. The Effect of Prebiotic and Probiotic Feed Supplementation on the Wax Glands of Worker Bees (Apis Mellifera

    Directory of Open Access Journals (Sweden)

    Silvia Pătruică


    Full Text Available This paper presents the effects of acidifying substances (lactic acid or acetic acid, Enterobiotics products(Lactobacillus acidophilus LA-14 and Bifidobacterium lactis BI-04 and Enterolactis Plus (Lactobacillus casei onthe wax glands of worker bees. The research was conducted in Timis County, Romania, between March 25 and April20, 2011, on 110 colonies of bees (Apis mellifera carpatica, allocated to 11 experimental treatment groups. Coloniesin the experimental groups were given three weekly feeds of sugar syrup supplemented with acidifying substances(lactic acid or cider vinegar and/or probiotic products (Enterobiotics or Enterolactis Plus. Three weeks after theadministration of the experimental diets, 10 worker bees from each treatment group were sampled for histologicalexamination of their wax glands. Gland development was shown to be influenced by administration of prebioticand/or probiotic supplements. Wax gland cell sizes ranged from 25.1 microns for the control group to between 27.8and 31.8 microns in the group fed with acidifying substances and between 26.9 and 29.2 microns in bees fed withprobiotic products. Bees supplemented with both lactic acid and probiotic product (group LE9 and LE10 showedmean wax cell sizes of 31.8 microns.

  6. Micromorphology of epicuticular waxes and epistomatal chambers of pine species by electron microscopy and white light scanning interferometry. (United States)

    Kim, Ki Woo; Lee, In Jung; Kim, Chang Soo; Lee, Don Koo; Park, Eun Woo


    High-resolution imaging and quantitative surface analysis of epicuticular waxes and epistomatal chambers of pine species were performed by field emission scanning electron microscopy and white light scanning interferometry. Both juvenile and adult needles were collected from the two-year-old seedlings of Pinus rigida and Pinus densiflora and subjected to surface observations. Epicuticular wax structures developed on the cuticle layer as well as in the epistomatal chambers and appeared to occlude the cavities in the two pine species. The stomata of P. densiflora were characterized by more distinctly raised rings around openings than P. rigida. The most common epicuticular wax structures of the two pine species included tubules with terminal openings and coiled rodlets. Wax platelets were deposited on epistomatal chambers. Either rodlets or tubules seemed to be longer and thicker in P. rigida than those in P. densiflora. White light scanning interferometry revealed quantitative surface profiles, demonstrating more ridged (ca. 4 μm high) stomatal apertures and nearly twofold deeper (ca. 20 μm deep) epistomatal chambers of P. densiflora than those of P. rigida. These results suggest that white light scanning interferometry can be applied to unravel the quantitative surface features of epicuticular sculptures on plant leaves.

  7. Direct investigations of deformation and yield induced structure transitions in polyamide 6 below glass transition temperature with WAXS and SAXS

    DEFF Research Database (Denmark)

    Guo, Huilong; Wang, Jiayi; Zhou, Chengbo;


    Deformation and yield induced structure transitions of polyamide 6 (PA6) were detected with the combination of the wide- and small-angle X-ray scattering (WAXS and SAXS) at 30 degrees C below glass transition temperature (T-g) of PA6. During deformation, gamma-alpha phase transition was found at ...

  8. Role of wax model museums in the teaching of dermatovenerology at medical universities of Russia and Europe

    Directory of Open Access Journals (Sweden)

    Utz S.R.


    Full Text Available The article shows the history and the significance of use of wax masks in the process of visual teaching of dermatology and venereology for students of medical universities in Europe and Russia in the XIX-XX centuries.

  9. Seasonally chancing preen-wax composition : Red Knots' (Calidris canutus) flexible defense against feather-degrading bacteria?

    NARCIS (Netherlands)

    Reneerkens, Jeroen; Versteegh, Maaike A.; Schneider, Amy M.; Piersma, Theunis; Burtt, Edward H.; James, H.F.


    During incubation, ground-breeding sandpipers such as Red Knots (Calidris canutus) create a warm, humid micro-climate in the nest, conditions that favor the growth of feather-degrading bacteria present in their plumage. just before incubation, the composition of waxes secreted by the uropygial gland

  10. Influence of waxing coupled to 1-methylcyclopropene on compositional changes in early harvested ‘gold’ pineapple for export

    Directory of Open Access Journals (Sweden)

    Francisca Ligia de Castro Machado


    Full Text Available This work evaluated the changes in quality in early-harvested ‘Gold’ pineapple after coating with wax and exposure to 1-Methylcycloprepene before or after coating. The storage conditions and the experimental period simulated those of shipping and marketing, assuming that Ceará,Brazil, is the production site andEuropeis the marketplace. Evaluation was performed after harvest, upon removal of the fruit from cold storage, and every three days during room storage. Evaluations included visual quality of the fruit, shell yellowing, mass loss, flesh color, soluble solids, titratable acidity, pH, soluble solids to acid ratio, ascorbic acid, total soluble sugars, reducing sugar, phenolic content, and yellow flavonoids. Low temperature was the key variable for maintaining fruit quality during storage and simulated shipping. Waxing had a remarkable effect on visual quality, delaying yellowing and reducing shell dehydration. Those effects were not enhanced by the application of 1-MCP. 1-MCP treatment resulted in the maintenance of total phenolic content and retention of yellow flavonoids. Fruit flesh became lighter, while yellow color became more vivid during storage. Sugars and pH varied little during storage, while the decline in TA was more intense in waxed fruit. 1-MCP and waxing may be combined to preserve external and internal quality.

  11. 一种水果保鲜乳化蜡的研制%Development of Emulsified Wax for Fruit Preservation

    Institute of Scientific and Technical Information of China (English)

    吴国江; 陈艳华; 王丽君


    研究了用58#全炼蜡、改性高分子聚合物制备水果保鲜光乳化蜡的方法.考查了石蜡、改性高分子聚合物二者的比例、复合乳化剂对乳液性能的影响.实验结果表明,当乳化剂用量为乳液质量的5%,乳化温度为90~95℃,乳化时间为30 ~40 min时,可以制取一种水果保鲜乳化蜡.%A method to prepare emulsified wax for fruit preservation from 58* fully refined paraffin wax and modified high molecular polymer was studied.Effects of ratio of paraffin wax to the polymer,complex emulsificrs on the emulsion properties were specially investigated.The results show that the emulsified wax for frail preservation can be prepared when the emulsifier is 5% by emulsion mass,emulsifying temperature is at 90-95 ℃ and emulsifying time is 30~40 min.

  12. Using a multi-layered transducer model to estimate the properties of paraffin wax deposited on steel. (United States)

    Rommetveit, Tarjei; Johansen, Tonni F; Johnsen, Roy


    When using ultrasound for detecting low impedance materials on the surface of high impedance materials, a major challenge is the contrast difference between the strong reverberations from the high impedance material and the weak echoes received from the low impedance material. The purpose of this work is to present the theoretical and experimental validation of an ultrasonic methodology for estimating the acoustical properties of paraffin wax on the surface of steel. The method is based on modeling and inversion of the complete electro-acoustic channel from the transmitted voltage over the active piezoelectric element, to the received voltage resulting from the acoustic reverberations in the multilayered structure. In the current work, two conceptually different models of the same multi-layer transducer structure attached to steel is developed and compared with measurements. A method is then suggested for suppressing the strong reverberations in steel, hence isolating the wax signals. This contrast enhancement method is fitted to the model of the structure, facilitating parameter inversion from the wax layer. The results show that the models agree well with measurements and that up to three parameters (travel time, impedance and attenuation) can be inverted from the wax simultaneously. Hence, given one of the three parameters, density, sound speed or thickness, the other two can be estimated in addition to the attenuation.

  13. "Paraffin wax-overlay of pour plate", a method for the isolation and enumeration of purple non-sulfur bacteria. (United States)

    Archana, A; Sasikala, Ch; Ramana, Ch V; Arunasri, K


    A modification of pour plate technique with an overlay of wax was used for isolation and enumeration of purple non-sulfur bacteria (PNSB) with equal efficiency as that of agar shake culture. The total count of PNSB ranged from 10(5)-10(8) CFU g dry soil(-1) and belonged to the genera of Rhodobacter, Rhodopseudomonas, Rhodocista and Rubrivivax.

  14. Leaf cuticular wax amount and crystal morphology regulate post-harvest water loss in mulberry (Morus species). (United States)

    Mamrutha, H M; Mogili, T; Jhansi Lakshmi, K; Rama, N; Kosma, Dylan; Udaya Kumar, M; Jenks, Matthew A; Nataraja, Karaba N


    Mulberry leaves are the sole source of food for silkworms (Bombyx mori), and moisture content of the detached leaves fed to silkworms determines silkworm growth and cocoon yield. Since leaf dehydration in commercial sericulture is a serious problem, development of new methods that minimize post-harvest water loss are greatly needed. In the present study, variability in moisture retention capacity (MRC, measured as leaf relative water content after one to 5 h of air-drying) was examined by screening 290 diverse mulberry accessions and the relationship between MRC and leaf surface (cuticular) wax amount was determined. Leaf MRC varied significantly among accessions, and was found to correlate strongly with leaf wax amount. Scanning electron microscopic analysis indicated that leaves having crystalline surface waxes of increased facet size and density were associated with high MRC accessions. Leaf MRC at 5 h after harvest was not related to other parameters such as specific leaf weight, and stomatal frequency and index. This study suggests that mulberry accessions having elevated leaf surface wax amount and crystal size and density exhibit reduced leaf post-harvest water loss, and could provide the foundation for selective breeding of improved cultivars. Copyright 2010 Elsevier Masson SAS. All rights reserved.

  15. Molecular characterization of the fatty alcohol oxidation pathway for wax-ester mobilization in germinated jojoba seeds (United States)

    Jojoba (Simmondsia chinensis) is the only plant species known to use liquid wax esters (WE) as a primary seed storage reserve. Upon germination, WE hydrolysis releases very long-chain fatty alcohols, which must be oxidised to fatty acids by the sequential action of a fatty alcohol oxidase (FAO) and ...


    Institute of Scientific and Technical Information of China (English)

    Jun-ting Xu; Bo-tao Li; Zhi-qiang Fan; Anthony J. Ryan


    The fractions of one metallocene-based (mPE) and one conventional (znPE) ethylene-butene copolymer eluted at 80-82℃ from temperature rising elution fractionation were selected for DSC and time-resolved small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS) characterization. The DSC and WAXS results show that two crystal structures exist in both mPE and znPE: structure A with higher melting temperature and structure B with lower melting temperature. It was found that original znPE (s-znPE) contains more highly ordered structure A than original mPE (s-mPE)in spite of the higher comonomer content of znPE. Another structure C is also identified because of higher crystallinity measured by WAXS than by DSC and is attributed to the interfacial region. The SAXS data were analyzed with correlation function and two maxima were observed in s-mPE and s-znPE, in agreement with the conclusion of two crystal populations drawn from DSC and WAXS results. These two crystal populations have close long periods in s-mPE, but very different long periods in s-znPE. In contrast, freshly crystallized mPE and znPE (f-mPE and f-znPE) contain only a single crystal population with a broader distribution of long period.

  17. Over-Expression of SlSHN1 Gene Improves Drought Tolerance by Increasing Cuticular Wax Accumulation in Tomato

    Directory of Open Access Journals (Sweden)

    Ayed M. Al-Abdallat


    Full Text Available Increasing cuticular wax accumulation in plants has been associated with improving drought tolerance in plants. In this study, a cDNA clone encoding the SlSHN1 transcription factor, the closest ortholog to WIN/SHN1 gene in Arabidopsis, was isolated from tomato plant. Expression analysis of SlSHN1 indicated that it is induced in response to drought conditions. The over-expression of SlSHN1 in tomato under the control of the constitutive CaMV 35S promoter produced plants that showed mild growth retardation phenotype with shiny and dark green leaves. Scanning electron microscopy showed that the over-expression of SlSHN1 in tomato resulted in higher cuticular wax deposition on leaf epidermial tissue when compared to non-transformed plants. Expression analysis in transgenic lines over-expressing SlSHN1 indicated that several wax-related synthesis genes were induced. Transgenic tomato plants over-expressing SlSHN1 showed higher drought tolerance when compared with wild type plants; this was reflected in delayed wilting of transgenic lines, improved water status and reduced water loss rate when compared with wild type plants. In conclusion, the SlSHN1 gene can modulate wax accumulation and could be utilized to enhance drought tolerance in tomato plant.

  18. Late Quaternary environmental change in the interior South American tropics: new insight from leaf wax stable isotopes (United States)

    Fornace, Kyrstin L.; Whitney, Bronwen S.; Galy, Valier; Hughen, Konrad A.; Mayle, Francis E.


    Stable isotope analysis of leaf waxes in a sediment core from Laguna La Gaiba, a shallow lake located at the Bolivian margin of the Pantanal wetlands, provides new perspective on vegetation and climate change in the lowland interior tropics of South America over the past 40,000 years. The carbon isotopic compositions (δ13C) of long-chain n-alkanes reveal large shifts between C3- and C4-dominated vegetation communities since the last glacial period, consistent with landscape reconstructions generated with pollen data from the same sediment core. Leaf wax δ13C values during the last glacial period reflect an open landscape composed of C4 grasses and C3 herbs from 41-20 ka. A peak in C4 abundance during the Last Glacial Maximum (LGM, ∼21 ka) suggests drier or more seasonal conditions relative to the earlier glacial period, while the development of a C3-dominated forest community after 20 ka points to increased humidity during the last deglaciation. Within the Holocene, large changes in the abundance of C4 vegetation indicate a transition from drier or more seasonal conditions during the early/mid-Holocene to wetter conditions in the late Holocene coincident with increasing austral summer insolation. Strong negative correlations between leaf wax δ13C and δD values over the entire record indicate that the majority of variability in leaf wax δD at this site can be explained by variability in the magnitude of biosynthetic fractionation by different vegetation types rather than changes in meteoric water δD signatures. However, positive δD deviations from the observed δ13C- δD trends are consistent with more enriched source water and drier or more seasonal conditions during the early/mid-Holocene and LGM. Overall, our record adds to evidence of varying influence of glacial boundary conditions and orbital forcing on South American Summer Monsoon precipitation in different regions of the South American tropics. Moreover, the relationships between leaf wax stable

  19. Is wax equivalent to tissue in electron conformal therapy planning? A Monte Carlo study of material approximation introduced dose difference. (United States)

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


    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.

  20. Hydrogen isotope composition of leaf wax n-alkanes in glaucous and non-glaucous varieties of wheat (Triticum spp.) (United States)

    Pedentchouk, Nikolai; Eley, Yvette; Frizell-Armitage, Amelia; Uauy, Cristobal


    The use of the 2H/1H composition of terrestrial plants in climate and ecology studies depends on fundamental understanding of the processes within the plant that control fractionation of these two isotopes. Little is currently known about the extent of 2H/1H fractionation at different steps of biosynthesis, after the initial H uptake following leaf water photolysis. Knowing this effect is particularly important when seeking to interpret the 2H/1H composition of leaf wax biomarkers from plants that differ in the amount and type of individual compound classes in their leaf waxes. The purpose of this study was to investigate the link between the quantity and distribution of n-alkyl lipids in leaf waxes and their isotopic composition. We used a genetic approach to suppress glaucousness in 2 varieties of wheat (Alchemy and Malacca), which resulted in glaucous and non-glaucous phenotypes of both varieties. Both phenotypes were then grown outdoors under identical environmental conditions in central Norfolk, UK. At the end of the growing season, the plants were sampled for soil water, leaf water, and leaf wax isotopic measurements. Comparison of the leaf wax composition of the non-glaucous and glaucous phenotypes revealed that the non-glaucous varieties were characterised by the absence of diketones and a greater concentration of n-alkanes and primary alcohols.. Our results showed very small differences between glaucous and non-glaucous varieties with regard to soil (mean values, composition of n-alkanes. The initial results of this work suggest that plants using the same environmental water, subjected to the same effects of evapotranspiration, but which differ in the amount and composition of leaf wax compounds, can exhibit large variation in their n-alkane 2H/1H. Our current work on determining the 2H/1H composition of other n-alkyl lipids from these plants will provide further details regarding the role of biosynthesis in controlling 2H/1H fractionation within leaf

  1. Utility of Greater Wax Moth Larva (Galleria mellonella) for Evaluating the Toxicity and Efficacy of New Antimicrobial Agents. (United States)

    Desbois, Andrew P; Coote, Peter J


    There is an urgent need for new antimicrobial agents to combat infections caused by drug-resistant pathogens. Once a compound is shown to be effective in vitro, it is necessary to evaluate its efficacy in an animal infection model. Typically, this is achieved using a mammalian model, but such experiments are costly, time consuming, and require full ethical consideration. Hence, cheaper and ethically more acceptable invertebrate models of infection have been introduced, including the larvae of the greater wax moth Galleria mellonella. Invertebrates have an immune system that is functionally similar to the innate immune system of mammals, and often identical virulence and pathogenicity factors are used by human pathogenic microbes to infect wax moth larvae and mammals. Moreover, the virulence of many human pathogens is comparable in wax moth larvae and mammals. Using key examples from the literature, this chapter highlights the benefits of using the wax moth larva model to provide a rapid, inexpensive, and reliable evaluation of the toxicity and efficacy of new antimicrobial agents in vivo and prior to the use of more expensive mammalian models. This simple insect model can bridge the gap between in vitro studies and mammalian experimentation by screening out compounds with a low likelihood of success, while providing greater justification for further studies in mammalian systems. Thus, broader implementation of the wax moth larva model into anti-infective drug discovery and development programs could reduce the use of mammals during preclinical assessments and the overall cost of drug development. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. SUPERKILLER Complex Components Are Required for the RNA Exosome-Mediated Control of Cuticular Wax Biosynthesis in Arabidopsis Inflorescence Stems. (United States)

    Zhao, Lifang; Kunst, Ljerka


    ECERIFERUM7 (CER7)/AtRRP45B core subunit of the exosome, the main cellular 3'-to-5' exoribonuclease, is a positive regulator of cuticular wax biosynthesis in Arabidopsis (Arabidopsis thaliana) inflorescence stems. CER7-dependent exosome activity determines stem wax load by controlling transcript levels of the wax-related gene CER3 Characterization of the second-site suppressors of the cer7 mutant revealed that small interfering RNAs (siRNAs) are direct effectors of CER3 expression. To explore the relationship between the exosome and posttranscriptional gene silencing (PTGS) in regulating CER3 transcript levels, we investigated two additional suppressor mutants, wax restorer1 (war1) and war7. We show that WAR1 and WAR7 encode Arabidopsis SUPERKILLER3 (AtSKI3) and AtSKI2, respectively, components of the SKI complex that associates with the exosome during cytoplasmic 3'-to-5' RNA degradation, and that CER7-dependent regulation of wax biosynthesis also requires participation of AtSKI8. Our study further reveals that it is the impairment of the exosome-mediated 3'-5' decay of CER3 transcript in the cer7 mutant that triggers extensive production of siRNAs and efficient PTGS of CER3. This identifies PTGS as a general mechanism for eliminating highly abundant endogenous transcripts that is activated when 3'-to-5' mRNA turnover by the exosome is disrupted. Diminished efficiency of PTGS in ski mutants compared with cer7, as evidenced by lower accumulation of CER3-related siRNAs, suggests that reduced amounts of CER3 transcript are available for siRNA synthesis, possibly because CER3 mRNA that does not interact with SKI is degraded by 5'-to-3' XRN4 exoribonuclease.

  3. Examining of slurries and production of moulds by spraying method in lost wax technology

    Directory of Open Access Journals (Sweden)

    M. Nadolski


    Full Text Available The work presents the results of investigation centred around the selection of a ceramic slurry composition if ceramic fibre is applied as a component of moulding material used for the lost wax technology. Producing a ceramic material of assumed parameters demands for changing the surface properties of the mineral grains. The critical concentration of solid particles or the gel point depends on the size of mineral particles, their shape and ability to aggregate. This ability has been achieved by modifying their surface properties by adding some polymer and the wetting agent (surfactant, which are adsorbed. Using the fibre material has required developing a method of its applying to the pattern set. The technology of multi-layer spraying has been recognised as the most advantageous one. The performed laboratory experiments have allowed for determining both the material composition and the parameters of its applying, such as air pressure, nozzle diameter, and the spraying distance for gravity pneumatic spraying gun.

  4. Pesticides for apicultural and/or agricultural application found in Belgian honey bee wax combs. (United States)

    Ravoet, Jorgen; Reybroeck, Wim; de Graaf, Dirk C


    In a Belgian pilot study honey bee wax combs from ten hives were analyzed on the presence of almost 300 organochlorine and organophosphorous compounds by LC-MS/MS and GC-MS/MS. Traces of 18 pesticides were found and not a single sample was free of residues. The number of residues found per sample ranged from 3 to 13, and the pesticides found could be categorized as (1) pesticides for solely apicultural (veterinary) application, (2) pesticides for solely agricultural (crop protection) application, (3) pesticides for mixed agricultural and apicultural (veterinary) application. The frequencies and quantities of some environmental pollutants bear us high concerns. Most alarming was the detection of lindane (gamma-HCH) and dichlorodiphenyltrichloroethane (including its breakdown product dichlorodiphenyldichloroethylene), two insecticides that are banned in Europe. The present comprehensive residue analysis, however, also reveals residues of pesticides never found in beeswax before, i.e. DEET, propargite and bromophos.

  5. Structure and Stability of Fish Oil Organogels Prepared with Sunflower Wax and Monoglyceride. (United States)

    Öǧütcü, Mustafa; Temizkan, Riza; Arifoǧlu, Nazan; Yılmaz, Emin


    The aims of this study were to develop fish oil (FO) organogels with sunflower wax (SW) and monoglyceride (MG), and compare them with a commercial margarine (CM). The organogels were stored at 4 and 20°C for 90 days and their storage stability was investigated. The color values, oil binding capacity, crystal formation time, solid fat content, thermal properties and crystal structures of the organogels were measured. During storage, their textural properties and peroxide values were monitored. The melting temperature of the MG organogels was found similar to that of the CM sample. Otherwise, the melting points of the MG gels were lower than those of the SW gels. Crystal morphology of the CM sample was found similar to MG gels by X-ray measurements. The firmness values of the SW organogels were higher than those of the MG gels. The peroxide values of all gels were within the legal limits.

  6. Bee Wax Propolis Extract as Eco-Friendly Corrosion Inhibitors for 304SS in Sulfuric Acid

    Directory of Open Access Journals (Sweden)

    Femiana Gapsari


    Full Text Available The inhibition properties of bee wax propolis (BWP extract on the 304SS in 0.5 M sulfuric acid were conducted using potentiodynamic polarization, EIS, and XRD. Quercetin (2-(3.4-dihydroxy phenyl-3.5.7-trihydroxy-4H-chromen-4-one was identified as the main compound in the BWP extract based on FTIR and HPLC analysis. The results showed that the inhibitor could retard the corrosion rate of 304SS in 0.5 M sulfuric acid which reached 97.29% and 91.42% at 2000 ppm based on potentiodynamic polarization and EIS measurement, respectively. The inhibition efficiency decreased with increasing temperature. The inhibition mechanism of BWP extract on the 304SS was physisorption and obeyed Temkin adsorption isotherm equation. The thin protective layer on the 304SS surface was confirmed by XRD.

  7. Oleogels of virgin olive oil with carnauba wax and monoglyceride as spreadable products

    Directory of Open Access Journals (Sweden)

    Öǧütcü, M.


    Full Text Available The oleogels of virgin olive oil with carnauba wax and monoglyceride were prepared to determine the most suitable spreadable product. The oil binding capacities of monoglyceride oleogels were higher than those of the carnauba wax oleogels. There was no true crystalline structure with carnauba wax at 3%. Although the highest solid fat content was in the 10% monoglyceride oleogel (9.38%, it was 12.15% in the commercial breakfast margarine at 20 °C. The peak melting temperature of the margarine was 47.11 °C, and among all oleogels, monoglyceride oleogel at 7% addition had the closest value (48.70 °C. The melting enthalpies of the oleogels ranged from 1.25 to 103.97 J·g−1, while it was 94.19 J·g−1 for the margarine sample. The firmness and stickiness values were usually lower in the oleogel samples than those of the margarine sample. There was no significant change in the texture parameters during storage, indicating good structural stability. The polarized light microscopy pictures revealed rod-like crystals for carnauba wax and rosette-like aggregates for monoglyceride oleogels. X-ray diffraction patterns of the samples have revealed a β´-type polymorphic structure for the oleogels. These oleogels can be used in a spreadable, breakfast margarin-like product to promote new consumption habits for this healthy oil.Se prepararon oleogeles de aceites de oliva virgen con cera de carnaúba y monoglicéridos para encontrar el producto más adecuado para untar. La capacidad de unión de aceites de oleogeles de monoglicéridos fue más alto que el de los oleogeles de cera de carnaúba. No hubo ninguna estructura cristalina verdadera con cera de carnaúba al 3%. Aunque el mayor contenido de grasa sólida fue con el 10 % de oleogeles de monoglicérido (9,38 %, fue del 12.15 % en el de margarina comercial a 20 °C. La temperatura pico de fusión de la margarina fue 47,11 ºC, y entre todos los oleogeles, los de monoglicérido al 7 % tuvo el valor m

  8. Simplified procedures for applying the polymerase chain reaction to routinely fixed paraffin wax sections. (United States)

    Coates, P J; d'Ardenne, A J; Khan, G; Kangro, H O; Slavin, G


    The polymerase chain reaction was applied to the analysis of DNA contained in archival paraffin wax embedded material. DNA suitable for the reaction was obtained from these tissues by simple extraction methods, without previous dewaxing of tissue sections. When compared with unfixed material, the reaction efficiency was compromised, so that an increased number of amplification cycles were required to produce equivalent amounts of amplified product. This in turn led to an increase in amplification artefacts, which can be minimised by a simple modification of the standard reaction. Amplification of relatively large DNA fragments was not always successful, and it seems prudent to bear this in mind when designing oligonucleotide primers which are to be used for the amplification of archival material. The efficiency of the procedure can be improved by dividing the amplification cycles into two parts: this reduces the amount of reagent needed, is relatively simple and inexpensive, and can be performed in one working day.

  9. Influence of gamma radiation on hindered phenols in LDPE, paraffin oil and paraffin wax (United States)

    Ahmed, Shamshad; Yasin, Tariq; Ghaffar, Abdul


    Extraction and high performance liquid chromatography procedures have been developed for the determination of two hindered phenols—Irganox-1010 and Santonox ®, incorporated in low density polyethylene (LDPE), paraffin oil and paraffin wax at varied concentrations. These blends were gamma irradiated from 25 to 400 kGy and the radiation and thermal stability of the antioxidant under the experimental conditions has been determined. Upon increase in radiation dose from 25 to 400 kGy, a gradual diminution in the extractable level of each antioxidant was observed. The fate of both the antioxidants in various matrices has been compared. It has been shown that both the antioxidants can influence the polyethylene network formation and the radical yield in different ways resulting in retardation in the rate of crosslinking, as determined by gel-content analysis.

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

    Institute of Scientific and Technical Information of China (English)


    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.

  11. Hepatitis C virus genotype testing in paraffin wax embedded liver biopsies for specimen identification. (United States)

    Ikura, Y; Ohsawa, M; Hai, E; Jomura, H; Ueda, M


    Despite advances in medical technology, careful specimen identification is still a fundamental principle of laboratory testing. If pathological samples are mixed up, especially in the case of extremely small biopsy samples, large amounts of time and energy may be wasted in correctly identifying the specimens. Recently, two liver biopsy specimens were mixed up in this department, and a new pathological technology was used to resolve the issue. Liver biopsy was performed on two patients with hepatitis C virus (HCV) infection. During sample transfer or tissue processing, the biopsy specimens were mixed up. Because the ABO blood group of the two patients was identical (type AB), the specimens were subsequently identified by analysing the HCV genotypes. RNA extracted from the paraffin wax embedded liver specimens was examined by a polymerase chain reaction based HCV genotype assay. This enabled the correct identification of the specimens, and each patient received the appropriate treatment on the basis of the accurate diagnosis.

  12. Airborne radar imaging of subaqueous channel evolution in Wax Lake Delta, Louisiana, USA (United States)

    Shaw, John B.; Ayoub, Francois; Jones, Cathleen E.; Lamb, Michael P.; Holt, Benjamin; Wagner, R. Wayne; Coffey, Thomas S.; Chadwick, J. Austin; Mohrig, David


    Shallow coastal regions are among the fastest evolving landscapes but are notoriously difficult to measure with high spatiotemporal resolution. Using Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) data, we demonstrate that high signal-to-noise L band synthetic aperture radar (SAR) can reveal subaqueous channel networks at the distal ends of river deltas. Using 27 UAVSAR images collected between 2009 and 2015 from the Wax Lake Delta in coastal Louisiana, USA, we show that under normal tidal conditions, planform geometry of the distributary channel network is frequently resolved in the UAVSAR images, including ~700 m of seaward network extension over 5 years for one channel. UAVSAR also reveals regions of subaerial and subaqueous vegetation, streaklines of biogenic surfactants, and what appear to be small distributary channels aliased by the survey grid, all illustrating the value of fine resolution, low noise, L band SAR for mapping the nearshore subaqueous delta channel network.

  13. Skin-effect down hole electric heater for heavy oil and high wax content oil applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chenglin; Wang, Hui; Liu, Yanhua [Liaoning Huafu Petroleum High-Tech Co., Ltd. (China); Xiao, Jon H; Klotz, Eric [ANDMIR Environmental Group Canada Inc. (Canada)


    With the increased production of oil and the depletion of conventional reserves, operators have started to exploit heavy oil and high wax content oil. Adequate production of such oils is difficult to achieve due to viscosity increase and mobility decrease during lifting as a result of heat loss. The down-hole electric heater has been developed to resolve these issues with the application of skin-effect electric heating technology. The aim of this paper is to present how this technology improves the production of heavy oil and waxy oil. Applications of the technology to wells in Chinese oilfields are studied. Results proved the technology to be efficient while being based on a simple process and operating in an easy and safe manner. This paper showed that the down-hole electric heater is a breakthrough technology, resolving the issues encountered in the heavy oil and waxy oil exploitation field, with broad application prospects.

  14. Leaf wax n-alkane δD values are determined early in the ontogeny of Populus trichocarpa leaves when grown under controlled environmental conditions. (United States)

    Kahmen, Ansgar; Dawson, Todd E; Vieth, Andrea; Sachse, Dirk


    The stable hydrogen isotope ratios (δD) of leaf wax n-alkanes record valuable information on plant and ecosystem water relations. It remains, however, unknown if leaf wax n-alkane δD values record only environmental variation during the brief period of time of leaf growth or if leaf wax n-alkane δD values are affected by environmental variability throughout the entire lifespan of a leaf. To resolve these uncertainties, we irrigated Populus trichocarpa trees with a pulse of deuterium-enriched water and used compound-specific stable hydrogen isotope analyses to test if the applied tracer could be recovered from leaf wax n-alkanes of leaves that were at different stages of their development during the tracer application. Our experiment revealed that only leaf wax n-alkanes from leaves that had developed during the time of the tracer application were affected, while leaves that were already fully matured at the time of the tracer application were not. We conclude from our study that under controlled environmental conditions, leaf wax n-alkanes are synthesized only early in the ontogeny of a leaf. Our experiment has implications for the interpretation of leaf wax n-alkane δD values in an environmental context, as it suggests that these compounds record only a brief period of the environmental variability that a leaf experiences throughout its life.

  15. Influence of the presence of medium-soft paraffin wax on the morphology and properties of iPP/silver nanocomposites

    Directory of Open Access Journals (Sweden)

    M. P. Molaba


    Full Text Available The aim of this study was to investigate the presence of wax, different Ag nanoparticle contents, and different cooling rates from the melt, on the morphology, thermal and electrical conductivity, and dynamic mechanical properties of iPP. The Ag particles were well dispersed in the polymer, and formed nucleation centres for the crystallization of iPP. They were also well dispersed in iPP/wax, but they were located in the wax phase which was dispersed between the iPP spherulites. Generally the extent of filler agglomeration increased with increasing filler content. The Ag particles, whether in the iPP or wax phase, had little influence on the crystallinities and melting temperatures of iPP. The presence of Ag particles in iPP had little influence on its modulus, but the presence of both wax and Ag particles significantly improved the modulus of these nanocomposites. The thermal and electrical conductivities of the samples more significantly improved when both wax and Ag were present. With increasing Ag particle contents in both iPP/Ag and iPP/wax/Ag, the thermal conductivities increased, but leveled off at higher filler contents, while the electrical conductivities continuously increased with increasing filler contents. The slowly cooled samples had higher crystallinities than the quenched samples and therefore they were more thermally conductive than the quenched samples.

  16. Process and formulation variables in the preparation of wax microparticles by a melt dispersion technique. I. Oil-in-water technique for water-insoluble drugs. (United States)

    Bodmeier, R; Wang, J; Bhagwatwar, H


    Ibuprofen-wax (carnauba, paraffin, beeswax, and the semisynthetic glyceryl esters--Gelucire 64/02 and Precirol ATO5) microparticles were prepared without organic solvents as an alternative to polymeric microparticles. In the melt dispersion technique, the drug-wax melt was emulsified into a heated aqueous phase followed by cooling to form the microparticles. The microparticles were characterized with respect to their drug loading, and morphological and release properties. They were spherical and non-agglomerated and drug loading close to 60 per cent were achieved. The more hydrophilic waxes (Gelucire 64/02 or Precirol ATO5) could be prepared without the use of surfactants. With the other waxes, increasing amounts of sodium lauryl sulphate in the external aqueous phase decreased the drug loading because of drug solubilization when compared to the polymeric stabilizer, poly(vinyl alcohol). The type of wax, the rate of cooling, and the temperature of the aqueous phase had no significant effect on the drug loading because of the low solubility of the drug in the external aqueous phase. The drug release was controlled by the hydrophobicity of the wax. Besides ibuprofen, other water-soluble drugs (ketoprofen, indomethacin, hydrocortisone) were also encapsulated by this method. The wax microparticles could be formulated into an aqueous sustained-release oral suspension dosage form.

  17. The current situation of the special wax and preparation methods%特种蜡发展现状及制备方法展望

    Institute of Scientific and Technical Information of China (English)

    刘慧珍; 陈文艺; 刘莹; 姚二伟


    Reviews the current development status of special wax at home and abroad,and introduces some chemical modification methods of special wax,such as the oxidation of paraffin,chlorination of paraffin, cracking of paraffin,graft copolymerization of paraffin,fermentation,nitrification of paraffin and so on,and some by adding natural low molecular polyethylene wax,natural wax,functional additives,physical modifi-cation methods of synthetic wax,etc.And briefly points out that the applications of modified waxes with different modification methods in today's society and the outlook for the future development of paraffin wax in our country.%综述了当今国内外特种蜡的发展现状,并介绍了当今国内外特种蜡的一些化学改性方法,如石蜡的氧化、石蜡的氯化、石蜡的裂解、石蜡的接枝、发酵、硝化改性等,和一些通过添加低分子聚乙烯蜡、天然蜡、功能添加剂、合成蜡等的物理改性方法.并简要指出不同改性方法制备出的改性蜡在当今社会的一些应用以及对我国石蜡未来发展的展望.

  18. Oxidized wax as compatibilizer in linear low-density polyethylene-clay nanocomposites: x-ray diffraction and dynamic mechanical analysis. (United States)

    Geethamma, V G; Luyt, Adriaan S


    Oxidized paraffin wax was used as a compatibilizer in composites of linear low-density polyethylene and layered nano silicate clays. X-ray diffraction analyses were carried out to investigate the crystalline morphology of five types of clays, oxidized wax, and their composites with LLDPE. The composites exhibited different X-ray diffraction and dynamic mechanical behaviour in the presence of different clays. Generally, the composites retained the partially crystalline behaviour of LLDPE, and no exfoliation was observed. Increased amount of wax did not change the morphology in most cases. The incorporation of clay resulted in an observable increase in the storage modulus of LLDPE. These values also increased with the addition of oxidized wax for most of the composites. The loss modulus increased with the amount of clay, irrespective of its nature. In most cases these values also increased with the incorporation of wax. The composites with 10% clay and 10% oxidized wax showed the highest storage and loss moduli, irrespective of the nature of the clay. The tan delta values did not change considerably with the addition of clay or wax.

  19. The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers. (United States)

    Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K; Tomasi, Pernell; Dyer, John M; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Parsons, Eugene P; Jenks, Matthew A; Lü, Shiyou


    We report n-6 monounsaturated primary alcohols (C26:1, C28:1, and C30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4's principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation's effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem.

  20. Effect of Computer-Assisted Learning on Students' Dental Anatomy Waxing Performance. (United States)

    Kwon, So Ran; Hernández, Marcela; Blanchette, Derek R; Lam, Matthew T; Gratton, David G; Aquilino, Steven A


    The aim of this study was to evaluate the impact of computer-assisted learning on first-year dental students' waxing abilities and self-evaluation skills. Additionally, this study sought to determine how well digital evaluation software performed compared to faculty grading with respect to students' technical scores on a practical competency examination. First-year students at one U.S. dental school were assigned to one of three groups: control (n=40), E4D Compare (n=20), and Sirona prepCheck (n=19). Students in the control group were taught by traditional teaching methodologies, and the technology-assisted groups received both traditional training and supplementary feedback from the corresponding digital system. Five outcomes were measured: visual assessment score, self-evaluation score, and digital assessment scores at 0.25 mm, 0.30 mm, and 0.35 mm tolerance. The scores from visual assessment and self-evaluation were examined for differences among groups using the Kruskal-Wallis test. Correlation between the visual assessment and digital scores was measured using Pearson and Spearman rank correlation coefficients. At completion of the course, students were asked to complete a survey on the use of these digital technologies. All 79 students in the first-year class participated in the study, for a 100% response rate. The results showed that the visual assessment and self-evaluation scores did not differ among groups (p>0.05). Overall correlations between visual and digital assessment scores were modest though statistically significant (5% level of significance). Analysis of survey responses completed by students in the technology groups showed that profiles for the two groups were similar and not favorable towards digital technology. The study concluded that technology-assisted training did not affect these students' waxing performance or self-evaluation skills and that visual scores given by faculty and digital assessment scores correlated moderately.