WorldWideScience

Sample records for araldite

  1. FLAMMABILITY OF ARALDITE BASED COMPOSITE MIXED WITH INORGANIC RETARDANTS

    Directory of Open Access Journals (Sweden)

    ALI I. AL-MOSAWI

    2012-10-01

    Full Text Available Flammability characteristics of araldite based composite mixed with inorganic hybrid flame retardant represent zinc borate - antimony trioxide as a surface layer(4mm thickness have been studied by thermal erosion test . Antimony trioxide was added to zinc borate with various amounts (10%,20% and 30% to forming a hybrid flame retardant for enhance the action of this material to react flame . The result composite material was exposed to a direct flame generated from Oxyacetylene torch (3000ºC with different flame exposure intervals (10,20mm, and studies the range of resistance of retardant material layer to the flames and protected the substrate. The optimum results were with large percentage from protective layer which is zinc borate-30% antimony trioxide and large exposed distance.

  2. Eletrodo compósito à base de grafite-araldite®: aplicações didáticas Graphite-araldite® composite electrode: didactic applications

    Directory of Open Access Journals (Sweden)

    Carolina Maria Fioramonti Calixto

    2008-01-01

    Full Text Available A composite electrode prepared by mixing a commercial epoxy resin Araldite® and graphite powder is proposed to be used in didactic experiments. The electrode is prepared by the students and applied in simple experiments to demonstrate the effect of the composite composition on the conductivity and the voltammetric response of the resulting electrode, as well as the response in relation to the scan rate dependence on mass transport. The possibility of using the composite electrode in quantitative analysis is also demonstrated.

  3. Characteristics and fabrication of Geiger-Mueller counters with thin walls made of treated magnesium - Note about the use of araldite

    International Nuclear Information System (INIS)

    This report describes, first, the advantage of magnesium for the manufacturing of Geiger-Mueller counters: suitable for machining and polishing, but strong reactivity with the counter atmosphere in the case of magnesium-rich alloys. Thus, the inside wall of the counter (cylinder of 20 mm diameter and 6 cm length) requires a non-reactive protective coating with excellent sealing properties. The synthetic resin 'araldite' fulfills all these conditions. The second part of the report describes the different steps of the fabrication of magnesium wall counters: lathe work, machining down and chemical polishing of hulls, assembly, tight sealing, pumping, filling-up and control tests. The average service life of these counters is of about 4 months. A note about the use and properties (hardening, mechanical properties, resistance..) of araldite is given in appendix. (J.S.)

  4. Morphology of the human internal vertebral venous plexus : a cadaver study after intravenous Araldite CY 221 injection

    NARCIS (Netherlands)

    Groen, R J; Groenewegen, H J; van Alphen, H A; Hoogland, P V

    1997-01-01

    Reviewing the literature on the vascular anatomy of the spinal epidural space, it appeared that the knowledge of the internal vertebral venous plexus is limited. Injection studies of the entire internal vertebral venous plexus after application of modern techniques, to the best of our knowledge, hav

  5. Comparative study of anatomical specimens using plastination by araldite HY103, polypropylene resin, 6170H19 Orthocryl and silicone – A qualitative study

    Science.gov (United States)

    Pandit, Subhendu; Kumar, Sushil; Mishra, B.K.

    2015-01-01

    Background Most of the organs and tissues are preserved in formalin with its own set of disadvantages. Plastination is a unique method of permanently preserving tissue in a life like state. Plastination developed by western authorities is a labour and equipment intensive affair. Most common polymer used is S10, however this study uses easily available alternative polymers for plastination. Method Various polymers like Epoxy resins, Polypropylene resins, Orthocryl and silicone were used in plastinating the anatomical specimens. Specific methods were used for solid, hollow organs and brain specimens. The specimens were made to undergo stages of fixation, dehydration, impregnation and curing. The results were studied and interpreted under various parameters. Results The results were interpreted under various parameters like shrinkage, retention of colour, odour, pliability and retention of gross anatomy. The study concluded that Orthocryl and Epoxy resins retained maximum colour with minimal shrinkage while maximum discolouration was with polypropylene plastinates. Brain sections were best preserved in Orthocryl. Conclusion The study concluded that indigenous methods and materials can produce quality plastinates which can be an important adjunct to traditional methods of teaching however more studies need to be done for refinement. PMID:26288492

  6. Re-examination of the dielectric spectra of epoxy resins: Bulk charge transport and interfacial polarization peaks

    OpenAIRE

    Chalashkanov, N. M.; Dodd, S J; Dissado, L. A.; Fothergill, J

    2014-01-01

    The dielectric properties of two amine cured bisphenol-A epoxy resin systems, Araldite CY1301 and Araldite CY1311 have been characterized using dielectric spectroscopy over the frequency range 1 mHz to 100 kHz. These two epoxy resin systems were chosen to allow the dielectric response to be studied from above and below the glass transition, as Araldite CY1311 is a modified version (with added plasticizer) of Araldite CY1301. The dielectric response was found to comprise both bulk and interfac...

  7. Influence of absorbed moisture on the dielectric properties of epoxy resins

    OpenAIRE

    Dodd, S J; Chalashkanov, N. M.; Dissado, L. A.; Fothergill, J

    2010-01-01

    The dielectric response of two bisphenol-A epoxy resin systems Araldite CY1301 (Tg ~ 50°C) and Araldite CY1311 (Tg ~0°C) was studied at different levels of absorbed moisture. The dielectric measurements were carried out over the frequency range 1 mHz to 100 kHz and the results were characterised in terms of dc bulk electrical conduction and dielectric processes. The characteristic parameters (frequency and magnitude) of all processes have been found to be moisture dependent. In both resins ab...

  8. The Thermal and Mechanical Properties of Glues for the ATLAS SCT ModuleAssembly

    CERN Document Server

    Kholodenko, A G; Riadovikov, VN

    2000-01-01

    We perform measurements of $C_{kt}-$the coefficient of thermal conductivityof two types of glue proposed for using in mechanical structureof the SCT modules of ATLAS .We compare the thermal property of thecommonly used electronic industry applications glue familyARALDITE and $Si-organic$ glue ``ELASTOSIL 137-182'' .The coefficients of the thermal conductivity for Boron nitride filled ARALDITE 1102 and ELASTOSIL 137-182 are presented. The value of the strength at tension was tested. The main results of the our tests are in agreement withvalues specified by manufacturer.

  9. S-HCEP——一种新的低成本合成绝缘子材料%Shed Hydrophobic Cycloaliphatic Epoxy (S-HCEP)- a New Cost-efficient Housing Material for Composite Insulators

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Araldite S-HCEP, a new cost-efficient alternative housing material for composite insulators is briefly presented. Main topics of this paper are the results of two new studies on this material:①UV-weathering resistance in terms of hydrophobicity, roughness increase, surface resistance and flexibility. ②Leakage current behavior under salt fog conditions in comparison to other materials.

  10. Development of graphite-polymer composites as electrode materials

    Directory of Open Access Journals (Sweden)

    Carolina Maria Fioramonti Calixto

    2007-06-01

    Full Text Available Graphite powder was mixed to polyurethane, silicon rubber and Araldite® (epoxy in order to prepare composite materials to be used in the preparation of electrodes. Results showed that voltammetric response could be obtained when at least 50% of graphite (w.w-1 is present in the material. SEM and thermogravimetry were also used in the characterization of the composites.

  11. Ultrastrucmturaiml munogold labelling of vimentin filaments on postembedding ultrathin sections of arachnoid villi and meningiomas

    OpenAIRE

    Yamashima, Tetsumori; Tachibana, Osamu; Nitta, Hisashi; Yamaguchi, Narihito; Yamashita, Junkoh

    1989-01-01

    An immunoelectron microscopic technique for the labelling of vimentin intermediate filaments on postembedding ultrathin sections is reported. Arachnoid villi obtained at autopsy and meningiomas at surgery were fixed in 1% paraformaldehyde for 30 minutes, embedded without postfixation in Epon-Araldite mixture and polymerized at 37OC for 3 weeks. Ultrathin sections were etched in 2% KOH for 3 minutes and incubated with anti-vimentin monoclonal antibodies whic...

  12. Thermal Characterization and Optimization of the Pixel Module Support Structure for the Phase-1 Upgrade of the CMS Pixel Detector

    CERN Document Server

    Rauch, Max Philip

    2015-01-01

    article/pii/0011747168900570, accessed on 7/21/2015.[38] Torayca, T300 Data Sheet, http://www.toraycfa.com/pdfs/T300DataSheet.pdf, accessedon 8/12/2015.[39] Araldite, Araldite Standard,http://www.chemcenters.com/images/suppliers/169257/Araldite%20Standard.pdf, accessed on 6/19/2015.[40] S. Streuli, Paul-Scherrer-Institut (Villigen, Switzerland), private communication.[41] KERAFOL, Keratherm Thermal Grease: KP 98,http://www.mhw-intl.com/assets/greaseKP98.pdf, accessed on 6/19/2015.[42] K. Klein, 1. Physikalisches Institut B, RWTH Aachen, private communication.[43] COMSOL Multiphysics R Modeling Software,https://www.comsol.de/, accessed on 7/28/2015.[44] COMSOL Multiphysics R Heat Transfer Software,https://www.comsol.de/heat-transfer-module, accessed on 28.7.2015.[45] Picture taken from https://commons.wikimedia.org/wiki/File:Composite_3d.png, accessed on 7/28/2015.[46] Mitsubishi Chemical, Dialead, K13D2U, http://www.mitsubishichemical.com/DataSheets/CarbonFiber/PD%20K13D2U.pdf, accessed on 7/29/2015.[47] Tenc...

  13. A Brazilian disk test for the evaluation of the shear strength of epoxy-joined ceramics

    International Nuclear Information System (INIS)

    Brazilian disk test is here analyzed as a test method to determine the strength of joined ceramics. The test specimen consisted of two silicon carbide half-disks diametrically bonded with a brittle adhesive (Araldite AV119 (TM)). Several tests were performed with different angles of the adhesive layer with respect to the diametral line of loading. An elastic finite element analysis is used to determine the maximum shear stress and the normal compressive stress within the joint. Assuming a failure criterion based on a shear stress condition, this procedure allows evaluating the shear strength of the epoxy adhesive. (authors)

  14. Influence of water absorption in flexible epoxy resins on the space charge behaviour

    OpenAIRE

    Chalashkanov, N. M.; Dodd, S J; Fothergill, J

    2012-01-01

    The aim of the current work is to achieve a better understanding of the influence of water uptake in flexible epoxy resins on the space charge dynamics at high electric fields. The space charge behaviour was studied using pulsed electroacoustic (PEA) technique. The samples were prepared from Araldite CY1311, which is a bisphenol-A epoxy resin. This particular resin was chosen because its glass transition is 0°C and hence it is in a flexible state at room temperature. All samples were conditio...

  15. Identification of parameters of cohesive elements for modeling of adhesively bonded joints of epoxy composites

    Directory of Open Access Journals (Sweden)

    Kottner R.

    2013-12-01

    Full Text Available Adhesively bonded joints can be numerically simulated using the cohesive crack model. The critical strain energy release rate and the critical opening displacement are the parameters which must be known when cohesive elements in MSC.Marc software are used. In this work, the parameters of two industrial adhesives Hunstman Araldite 2021 and Gurit Spabond 345 for bonding of epoxy composites are identified. Double Cantilever Beam (DCB and End Notched Flexure (ENF test data were used for the identification. The critical opening displacements were identified using an optimization algorithm where the tests and their numerical simulations were compared.

  16. Testing temperature on interfacial shear strength measurements of epoxy resins at different mixing ratios

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Thomason, James L.; Minty, Ross;

    2015-01-01

    The interfacial properties as Interfacial Shear Stress (IFSS) in fibre reinforced polymers are essential for further understanding of the mechanical properties of the composite. In this work a single fibre testing method is used in combination with an epoxy matrix made from Araldite 506 epoxy resin...... and triethylenetetramine (TETA) hardener. The IFSS was measured by a microbond test developed for a Thermal Mechanical Analyzer. The preliminary results indicate that IFSS has an inverse dependency of both testing temperature and the mixing ratio of hardener and epoxy resin. Especially interesting was the decreasing...

  17. Thermosetting polymer for dynamic nuclear polarization: Solidification of an epoxy resin mixture including TEMPO

    Energy Technology Data Exchange (ETDEWEB)

    Noda, Yohei, E-mail: noda.yohei@jaea.go.jp [Quantum Beam Science Centre, Sector of Nuclear Science Research, Japan Atomic Energy Agency, Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan); Kumada, Takayuki [Quantum Beam Science Centre, Sector of Nuclear Science Research, Kansai Photon Science Institute, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Yamaguchi, Daisuke; Shamoto, Shin-ichi [Quantum Beam Science Centre, Sector of Nuclear Science Research, Japan Atomic Energy Agency, Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan)

    2015-03-11

    We investigated the dynamic nuclear polarization (DNP) of typical thermosetting polymers (two-component type epoxy resins; Araldite{sup ®} Standard or Araldite{sup ®} Rapid) doped with a (2,2,6,6-tetramethylpiperidine-1-yl)oxy (TEMPO) radical. The doping process was developed by carefully considering the decomposition of TEMPO during the solidification of the epoxy resin. The TEMPO electron spin in each two-component paste decayed slowly, which was favorable for our study. Furthermore, despite the dissolved TEMPO, the mixture of the two-component paste successfully solidified. With the resulting TEMPO-doped epoxy-resin samples, DNP experiments at 1.2 K and 3.35 T indicated a magnitude of a proton-spin polarization up to 39%. This polarization is similar to that (35%) obtained for TEMPO-doped polystyrene (PS), which is often used as a standard sample for DNP. To combine this solidification of TEMPO-including mixture with a resin-casting technique enables a creation of polymeric target materials with a precise and complex structure.

  18. 改性CVC织物涂料轧染工艺研究%Research on Pigment Pad Dyeing Process of Modified CVC Fabric

    Institute of Scientific and Technical Information of China (English)

    高亚宁; 谢永萍

    2013-01-01

    A new pigment padding process was explored on the basis of modified CVC fabric treated by self-made cationic modification agent. The dosages of adhesive and crosslinking agent, the curing temperature and time were optimized to obtain higher K/S value and color fastness to washing and rubbing. The results showed that the optimum condition was as follows:pigment 6 g/L, binder DH-103 15 g/L, Araldite PT810 crosslinking agent 10 g/L, curing at 180℃for 3 min.%  本文在采用自制阳离子改性剂对CVC织物改性的基础上,探索研究了新型涂料轧染工艺.通过对涂料轧染中粘合剂、交联剂用量以及焙烘温度和时间的优化,获得了较高的K/S值和耐皂洗、耐摩色牢度.优化后的工艺条件为涂料6 g/L,粘合剂DH-103用量15 g/L,Araldite PT810交联剂10 g/L,180℃焙烘3 min.

  19. Preventing, monitoring and curing the ageing in the LHCb Outer Tracker

    CERN Document Server

    Visser, Erwin Lourens; Bethlem, H L

    2010-01-01

    The modules of the LHCb Outer Tracker have shown to suffer from gain loss under irradiation at moderate intensities, a process known as ageing. The plastifier in the glue with which the detector modules were constructed, Araldite AY103-1, has been shown to be the culprit. In this thesis this is confirmed by irradiating a module constructed with Araldite AY105-1, which does not contain the harmful plastifier. Several methods to prevent and repair the gain loss exist. One preventive measure is the addition of oxygen. However, because of its electronegative nature, oxygen can capture some of the drifting electrons, thereby lowering the gain of the OT. Simulations have been done to investigate the effect of oxygen on the gain and efficiency. One method to remove the ageing is HV training. In this procedure the applied voltage is increased such, that the OT enters the discharge regime. These discharges mostly remove the ageing, but can take place anywhere in the straw tube, not necessarily at the location of the a...

  20. Shear and Thermal Testing of Adhesives for VELO Upgrade

    CERN Document Server

    De Capua, Stefano; Klaver, Suzanne; Parkes, Chris; Rodriguez Perez, Pablo; Shtipliyski, Antoni; Stelmasiak, Guy James

    2016-01-01

    As part of the R&D process of the LHCb VELO Upgrade, a study has been performed on the thermal and mechanical performance of the adhesives Stycast 2850FT, 3M 9461P, and Araldite 2011. One or more of these adhesives could be used to attach the ASICs and hybrids to the microchannel cooling substrate. Samples were irradiated at up to the maximum dose expected at the upgrade. Shear tests of the samples were made and a suitable performance obtained from all glues. Some failures were encountered with Stycast 2850FT glued samples and this is attributed to the sample preparation. The relative thermal conductivities of the adhesives were also determined by measuring the relative temperature difference across a glued joint while one side is heated.

  1. Sound attenuation in magnetorheological fluids

    Science.gov (United States)

    Rodríguez-López, J.; Elvira, L.; Resa, P.; Montero de Espinosa, F.

    2013-02-01

    In this work, the attenuation of ultrasonic elastic waves propagating through magnetorheological (MR) fluids is analysed as a function of the particle volume fraction and the magnetic field intensity. Non-commercial MR fluids made with iron ferromagnetic particles and two different solvents (an olive oil based solution and an Araldite-epoxy) were used. Particle volume fractions of up to 0.25 were analysed. It is shown that the attenuation of sound depends strongly on the solvent used and the volume fraction. The influence of a magnetic field up to 212 mT was studied and it was found that the sound attenuation increases with the magnetic intensity until saturation is reached. A hysteretic effect is evident once the magnetic field is removed.

  2. Investigations of the behaviour of fast growing cracks using numerical simulation calculations

    International Nuclear Information System (INIS)

    The behaviour of the SEN sample (flat tensile sample notched on one side) made of Araldite B resin during crack growth was simulated numerically using the finite difference process. In order to obtain the solution for the static initial state of the system after applying the load and before the crack starts, the system set into movement by applying the load was braked until it was in equilibrium. With the equilibrium condition as the initial condition and from the experimentally determined crack growth curves of twelve experiments, a relationship between the speed of fracture and the stress factor was determined with the simulation program, which agreed with the results of the shadow optics evaluation. (orig./HP) With 23 refs., 60 figs

  3. Ageing of the LHCb outer tracker

    CERN Document Server

    Blom, M R

    2009-01-01

    The modules of the LHCb outer tracker have shown to suffer severe gain loss under moderate irradiation. This process is called ageing. Ageing of the modules results from contamination of the gas system by glue, araldite AY 103-1, used in their construction. In this thesis the ageing process will be shown. The schemes known to reduce, reverse, or prevent ageing have been investigated to determine their effect on the detector performance. The addition of O2 to the gas mixture lowers the detector response by an acceptable amount and does not affect the gas transport properties significantly. The ageing rate is decreased after extensive flushing and HV training could eventually repair the irradiation damage. The risks of HV training have been assessed. Furthermore, several gaseous and aquatic additions have been tested for their capability to prevent, or moderate ageing, but none showed significant improvement.

  4. Application of bioethanol derived lignin for improving physico-mechanical properties of thermoset biocomposites.

    Science.gov (United States)

    Bajwa, Dilpreet S; Wang, Xinnan; Sitz, Evan; Loll, Tyler; Bhattacharjee, Sujal

    2016-08-01

    Lignin is the most abundant of renewable polymers next to cellulose with a global annual production of 70million tons, largely produced from pulping and second generation biofuel industries. Low value of industrial lignin makes it an attractive biomaterial for wide range of applications. The study investigated the application of wheat straw and corn stover based lignin derived from ethanol production for use in thermoset biocomposites. The biocomposite matrix constituted a two component low viscosity Araldite(®)LY 8601/Aradur(®) 8602 epoxy resin system and the lignin content varied from 0 to 25% by weight fraction. The analysis of the physical and mechanical properties of the biocomposites show bioethanol derived lignin can improve selective properties such as impact strength, and thermal stability without compromising the modulus and strength attributes. PMID:27131732

  5. 压实黏土干燥裂隙及渗透性能研究%DESICCATION CRACKS AND HYDRAULIC PERFORMANCE OF COMPACTED CLAY LINER VIA LABORATORY WET-DRY CYCLING TESTS

    Institute of Scientific and Technical Information of China (English)

    何俊; 万娟; 王宇

    2012-01-01

    压实黏土干燥过程中产生的裂隙可能对渗透性能有较大影响.通过室内模拟试验研究发现,裂隙面积率、裂隙总长度和裂隙宽度随含水率减小而增大.压实黏土中裂隙可分为主裂隙和次裂隙2类,次裂隙出现前后裂隙参数的变化速率有较大差异.较宽裂隙在湿化后不能完全愈合,干湿循环过程使压实黏土产生了不可逆的变化.采用试验筒壁上涂阿尔代胶的方法可以有效模拟土样中裂隙的形成,并能较好地防止侧漏.渗透试验发现,一次干湿循环导致压实黏土的渗透系数增大将近2个数量级.湿化过程中干燥裂隙不能完全愈合及微裂隙的形成可能是导致渗透系数增大的主要原因.%Desiccation cracks of compacted clay liner might have a great effect on its hydraulic conductivity. Dur-ing the decrease of its water content, its crack area ratio, length and width will increase. Desiccation cracks can be divided into the major and the minor types. There are obvious differences for the change rate of crack parameters before and after minor cracks appear. Wider cracks can't entirely heal after hydration, which reveals that the wet-dry cycling is irreversible for the compacted clay liner. Development of cracks in the clay can be monitored success-fully with the Araldite that was put on the inside wall surface of the test cylinder. The Araldite can also prevent side-leakage. One wet-dry cycling can increase the hydraulic conductivity of the compacted clay liner for nearly two orders in its magnitude. Non-completely-healing cracks and microcracks might be the main reasons for the increas-ing of hydraulic conductivity during the wet-dry cycling.

  6. Application of alcian blue in the electron microscopic study of mouse and human cerebral cortex nerve cells.

    Science.gov (United States)

    Castejón, H V; Castejón, O J; Viloria, M E

    1976-01-01

    Alcian blue is a cationic dye which has been used in the histochemical field for the demonstration of polyanions especially carboxylated and sulphated. The results obtained in neurons when this dye was applied to human and mouse cerebral cortex and studied with the electron microscope are the object of the present report. The CNS of normal adult mice was fixed by vascular perfusion with 2% glutaraldehyde-0.1 M sodium cacodylate-0.1 M sucrose at pH = 6.8 followed by the same fixative with the addition of 0.5% alcian blue. After perfusion, brain cortex was taken out, sectioned into small blocks and immersed in a fresh similar mixture and subsequently in OSO4. Blocks were dehydrated and embedded in araldite. Ultrathin sections were doubly stained with uranyl and lead salts. Human brain cortex taken from patients with cerebral edema was fixed by immersion with 6.5% glutaraldehyde-0.1 M sodium phosphate, pH = 7.4 followed by embedding in warm agar and sectioning in slices of 30 mum thickness which were impregnated by immersion in a mixture of 1% alcian blue-acetate buffer-3% glutaraldehyde at pH = 3.5 for 9 to 15 h at 4 degrees C and subsequently immersed in 1% buffered OSO4-0.1 M sucrose, pH = 7.4 for 2 h at 4 degrees S. Sections were dehydrated and embedded in araldite. Ultrathin sections were doubly stained by uranyl and lead salts. We have denominated the complete procedure in both instances GABOUL technique. The submicroscopic study of both tissues, at nerve cells, revealed the presence of an electron dense homogeneous substance thoroughly dispersed at the hyaloplasmic matrix of perikarya, processes and even synaptic endings. This substance was more evident around free and attached ribosomes, GOLGI apparatus, complex vesicles, dense bodies, microtubules, subsurface cisternae and synaptic vesicles. Canaliculi of endoplasmic reticulum and even the perinuclear cistern also showed a moderate content. It is suggested that this electron dense substance, being

  7. Morphology of Donor and Recipient Nerves Utilised in Nerve Transfers to Restore Upper Limb Function in Cervical Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Aurora Messina

    2016-09-01

    Full Text Available Loss of hand function after cervical spinal cord injury (SCI impacts heavily on independence. Multiple nerve transfer surgery has been applied successfully after cervical SCI to restore critical arm and hand functions, and the outcome depends on nerve integrity. Nerve integrity is assessed indirectly using muscle strength testing and intramuscular electromyography, but these measures cannot show the manifestation that SCI has on the peripheral nerves. We directly assessed the morphology of nerves biopsied at the time of surgery, from three patients within 18 months post injury. Our objective was to document their morphologic features. Donor nerves included teres minor, posterior axillary, brachialis, extensor carpi radialis brevis and supinator. Recipient nerves included triceps, posterior interosseus (PIN and anterior interosseus nerves (AIN. They were fixed in glutaraldehyde, processed and embedded in Araldite Epon for light microscopy. Eighty percent of nerves showed abnormalities. Most common were myelin thickening and folding, demyelination, inflammation and a reduction of large myelinated axon density. Others were a thickened perineurium, oedematous endoneurium and Renaut bodies. Significantly, very thinly myelinated axons and groups of unmyelinated axons were observed indicating regenerative efforts. Abnormalities exist in both donor and recipient nerves and they differ in appearance and aetiology. The abnormalities observed may be preventable or reversible.

  8. THE SYNERGISTIC EFFECT OF HYBRID FLAME RETARDANTS ON PYROLYSIS BEHAVIOUR OF HYBRID COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    M. T. ALBDIRY

    2012-06-01

    Full Text Available The aim of this investigation is to comprehensively understand the polymeric composite behavior under direct fire sources. The synergistic effects of hybrid flame retardant material on inhabiting the pyrolysis of hybrid reinforced fibers, woven roving (0°- 45° carbon and kevlar (50/50 wt/wt, and an araldite resin composites were studied. The composites were synthesised and coated primarily by zinc borate (2ZnO.3B2O3.3.5H2O and modified by antimony trioxide (Sb2O3 with different amounts (10-30 wt% of flame retardant materials. In the experiments, the composite samples were exposed to a direct flame source generated by oxyacetylene flame (~3000ºC at variable exposure distances of 10-20 mm. The synergic flame retardants role of antimony trioxide and zinc borate on the composite surface noticeably improves the flame resistance of the composite which is attributed to forming a protective mass and heat barrier on the composite surface and increasing the melt viscosity.

  9. New approaches to the full-field analysis of photoelastic stress patterns

    Science.gov (United States)

    Buckberry, C.; Towers, D.

    1996-06-01

    This paper presents two new methods that provide a complete solution for the automatic fringe analysis of photoelastic data. Previous solutions have not yet provided a complete full-field analysis of both fringe sets (isochromatic and isoclinic) over a multiple number of fringes with an automatic measurement of absolute magnitude. This paper reviews previous approaches and discusses the options along which this work has been directed. Specifically, two new algorithms are presented. Firstly, the combination of phase maps at three wavelengths in order to remove the isochromatic ambiguity at every π turning point, that would occur in a single phase map. Additionally, this algorithm allows the automatic measurement of absolute magnitude, providing the neutral axis is within the field of view. Secondly, a new method is proposed that removes the areas of 2π ambiguity in an isoclinic phase map by cross-correlating regions of low modulation at two different wavelengths. The algorithms are demonstrated by applying them to the analysis of an engine connecting rod. The rod was manufactured as a full-scale three-dimensional model in araldite (Ciba-Geigy CT200), from which a central slice was taken after having been stress frozen.

  10. Post-embedding tem signal-to-noise ratio of S-100

    Science.gov (United States)

    Fermin, C. D.; Lee, D. H.; Martin, D.

    1994-01-01

    We assessed the reactivity of purified S-100 antiserum in immuno-electron microscopy by counting the number of gold particles per microns 2 over inner ear tissues embedded in different media. Sections containing predominantly Schwann's cell cytoplasm and nucleus, afferent fiber axoplasm and myelin sheath of chick cochleae were reacted with anti-S-100 IgG, an antibody to a calcium binding protein of neuronal tissues, then labeled with anti-IgG-gold conjugate. This investigation was conducted because previously published procedures, unmodified, did not yield acceptable results. Preparation of all specimens was identical. Only the medium (PolyBed 812, Araldite or Spurr epoxies; and LR White, LR Gold or Lowicryl plastics) was changed. The medium was made the changing variable because antigens available in post-embedding immuno-electron microscopy are decreased by heat, either used and/or released during polymerization of the embedding medium. The results indicate that: (a) none of the embedding media above provided optimal signal-to-noise ratio for all parts of the nerve stained in the same section; (b) aggregation of gold particles over cells was highest in embedding media with high background labeling over areas devoid of tissue (noise); (c) aggregation occurred randomly throughout both cellular and acellular regions; and (d) particles aggregated less and were distributed more evenly in tissues from media yielding good ultrastructural integrity.

  11. Ultrastructural changes in blood vessels in epidermal growth factor treated experimental cutaneous wound model.

    Science.gov (United States)

    Kılıçaslan, Seda M Sarı; Cevher, Sule Coşkun; Peker, Emine G Güleç

    2013-11-01

    This study investigates the impact of epidermal growth factor (EGF) on blood vessels, specifically on the development of intussusceptive angiogenesis in cutaneous wound healing. Excisional wounds were formed on both sides of the medulla spinalis in dorsal location of the rats. The control and EGF-treated groups were divided into two groups with respect to sacrifice day: 5 d and 7 d. EGF was topically applied to the EGF-treated group once a day. The wound tissue was removed from rats, embedded in araldite and paraffin, and then examined under transmission electron and light microscopes. The ultrastructural signs of intussusceptive angiogenesis, such as intraluminal protrusion of endothelial cells and formation of the contact zone of opposite endothelial cells, were observed in the wound. Our statistical analyses, based on light microscopy observations, also confirm that EGF treatment induces intussusceptive angiogenesis. Moreover, we found that induction of EGF impact on intussusceptive angiogenesis is higher on the 7th day of treatment than on the 5th day. This implies that the duration of EGF treatment is important. This research clarifies the effects of EGF on the vessels and proves that EGF induces intussusceptive angiogenesis, being a newer model with respect to sprouting type.

  12. Properties of ‘Emu’ Feather Fiber Composites

    Directory of Open Access Journals (Sweden)

    V.Chandra Sekhar

    2015-08-01

    Full Text Available A composite is usually made up of at least two materials out of which one is binding material called matrix and the other is a reinforcement material known as fiber. Many researchers are focusing on natural fiber composites. But, in the present work, composites were prepared with epoxy (Araldite LY-556 resin and „emu‟ bird feathers as fiber. The composites were prepared by varying the weight percentage (P of „emu‟ fiber ranging from 1 to 5 and length (L of feather fibers from 1 to 5 cm. The composite specimens were prepared and cured as per ASTM standards. Studies were carried out on various properties like mechanical properties, Thermal properties and Effect of atmosphere, Soil and certain Chemicals. An attempt is made to model the mechanical properties through response surface methodology (RSM. Analysis of Variance (ANOVA is used to check the validity of the model. The results reveal that the developed models are suitable for prediction of mechanical properties of Epoxy „Emu‟ Feather Fiber Composites.

  13. Chemical Analysis of Emu Feather Fiber Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    V.Chandra sekhar

    2015-07-01

    Full Text Available A composite is usually made up of at least two materials out of which one is binding material called as matrix and other is a reinforcement material known as fiber. For the past ten years research is going on to explore possible composites with natural fiber like plant fibers and animal fibers. The important characteristics of composites are their strength, hardness light in weight. It is also necessary to study about the resistance of the composites for deferent chemicals. In the present work, composites prepared with epoxy (Araldite LY-556 as resin and „emu‟ bird feathers as fiber have been tested for chemical resistance. The composites were prepared by varying fiber loading (P of „emu‟ feathers ranging from 1 to 5 and length (L of feather fibers from 1 to 5 cm. The composites thus prepared were subjected to various chemicals (Acids, Alkalis, solvents etc.. Observations were plotted and studied. The results reveal that there will be weight gain for the composite samples after three days, when treated with Hydrochloric acid, Sodium carbonate, Acetic acid, Sodium hydroxide, Nitric acid and Ammonium hydroxide. Weight loss was observed for all the samples including pure epoxy when treated with Benzene, Carbon tetra chloride and Toluene.

  14. Of plants and other pets: practical aspects of freeze-substitution and resin embedding.

    Science.gov (United States)

    Hess, M W

    2003-10-01

    Representative tissues from higher plants (e.g. developing pollen, somatic anther tissues from the monocotyledonous angiosperm Ledebouria) and mammalian cell cultures were successfully cryoimmobilized by means of high-pressure freezing. Various substitution and embedding protocols were then evaluated considering the preservation of ultrastructural details, membrane staining, immunolabelling properties, as well as reproducibility and ease of use. Two types of recipe proved to be highly suitable for most applications, regardless of type, developmental stage or physiological conditions of the cells: (i) the best choice for morphology is still osmium in acetone (optionally supplemented with uranyl acetate) followed by embedding in Epon and/or Araldite; (ii) feasible approaches for immunocytochemistry are freeze-substitution with ethanol containing uranyl acetate and formaldehyde, or with pure acetone (in the case of fixation-sensitive antigens), followed by embedding with LR-white acrylic resin; though being far from optimal, these combinations represent, in my opinion, an acceptable compromise between labelling intensity, section stability, structural preservation and health hazards. Notably, the patterns observed in Ledebouria were consistent with data obtained from a broad range of other specimens from all kingdoms (e.g. leaves and callus cultures from angiosperms, gymnosperm roots with their ectomycorrhizal fungi, mammalian cell cultures and eubacteria). Finally, a warning is given as to the extractive potentials of embedding resins (Spurr's mixture, LR-white, but also Epon) being sometimes the cause of unacceptable artefacts, both in plant and in mammalian cells prepared by cryoimmobilization and freeze-substitution.

  15. Polymer Magnetic Composite Core Based Microcoils and Microtransformers for Very High Frequency Power Applications

    Directory of Open Access Journals (Sweden)

    Saravana Guru Mariappan

    2016-04-01

    Full Text Available We present a rapid prototyping and a cost effective fabrication process on batch fabricated wafer-level micro inductive components with polymer magnetic composite (PMC cores. The new PMC cores provide a possibility to bridge the gap between the non-magnetic and magnetic core inductive devices in terms of both the operating frequency and electrical performance. An optimized fabrication process of molding, casting, and demolding which uses teflon for the molding tool is presented. High permeability NiFeZn powder was mixed with Araldite epoxy to form high resistive PMC cores. Cylindrical PMC cores having a footprint of 0.79 mm 2 were fabricated with varying percentage of the magnetic powder on FR4 substrates. The core influence on the electrical performance of the inductive elements is discussed. Inductor chips having a solenoidal coil as well as transformer chips with primary and secondary coils wound around each other have been fabricated and evaluated. A core with 65% powder equipped with a solenoid made out of 25 µm thick insulated Au wire having 30 turns, yielded a constant inductance value of 2 µH up to the frequency of 50 MHz and a peak quality factor of 13. A 1:1 transformer with similar PMC core and solenoidal coils having 10 turns yielded a maximum efficiency of 84% and a coupling factor of 96%. In order to protect the solenoids and to increase the mechanical robustness and handling of the chips, a novel process was developed to encapsulate the components with an epoxy based magnetic composite. The effect on the electrical performance through the magnetic composite encapsulation is reported as well.

  16. Biomechanical Stability of Juvidur and Bone Models on Osteosyntesic Materials

    Science.gov (United States)

    Grubor, Predrag; Mitković, Milorad; Grubor, Milan; Mitković, Milan; Meccariello, Luigi; Falzarano, Gabriele

    2016-01-01

    Introduction: Artificial models can be useful at approximate and qualitative research, which should give the preliminary results. Artificial models are usually made of photo-elastic plastic e.g.. juvidur, araldite in the three-dimensional contour shape of the bone. Anatomical preparations consist of the same heterogeneous, structural materials with extremely anisotropic and unequal highly elastic characteristics, which are embedded in a complex organic structure. The aim of the study: Examine the budget voltage and deformation of: dynamic compression plate (DCP), locking compression plate (LCP), Mitkovic internal fixator (MIF), Locked intramedullary nailing (LIN) on the compressive and bending forces on juvidur and veal bone models and compared the results of these two methods (juvidur, veal bone). Material and Methods: For the experimental study were used geometrically identical, anatomically shaped models of Juvidur and veal bones diameter of 30 mm and a length of 100 mm. Static tests were performed with SHIMADZU AGS-X testing machine, where the force of pressure (compression) increased from 0 N to 500 N, and then conducted relief. Bending forces grew from 0 N to 250 N, after which came into sharp relief. Results: On models of juvidur and veal bones studies have confirmed that uniform stability at the site of the fracture MIF with a coefficient ranking KMIF=0,1971, KLIN=0,2704, KDCP=0,2727 i KLCP=0,5821. Conclusion: On models of juvidur and veal bones working with Shimadzu AGS-X testing machine is best demonstrated MIF with a coefficient of 0.1971. PMID:27708489

  17. A comparative study of vascular injection fluids in fresh-frozen and embalmed human cadaver forearms.

    Science.gov (United States)

    Doomernik, D E; Kruse, R R; Reijnen, M M P J; Kozicz, T L; Kooloos, J G M

    2016-10-01

    Over the years, various vascular injection products have been developed to facilitate anatomical dissections. This study aimed to compare the most commonly used vascular injection products in fresh-frozen and formalin-embalmed cadaver specimens. An overview of the properties, advantages and limitations of each substance was given, and a comparison of vascular infusion procedures in both preservation methods was made. A literature search was performed in order to identify the most commonly used vascular injection products. Acrylic paint, latex, gelatin, silicone, Araldite F and Batson's No. 17 were selected for the study. One fresh-frozen and one embalmed cadaver forearm were infused with each injection product according to a uniform protocol. The curing time, skin- and subcutaneous tissue penetration, degree of filling of the arterial tree, extravasations, consistency of the injected vessels during dissection, and the costs of each injection fluid were noted. There was a large variation between the injection fluids in processing- and curing time, colour intensity, flexibility, fragility, elasticity, strength, toxicity and costs. All fluids were suitable for infusion. The penetration of injection fluid into the skin and subcutaneous tissue was significantly better in fresh-frozen specimens (P = 0.002 and P = 0.009, respectively), with significantly smaller branches casted (P = 0.004). Vascular infusion of fresh-frozen cadaver specimens results in a significantly better filled coloured arterial tree, enabling more detail to be achieved and smaller branches casted. The biomechanical properties of fresh-frozen soft tissues are less affected compared with formalin fixation. All the injection fluids studied are suitable for vascular infusion, but their different properties ensure that certain products and procedures are more suitable for specific study purposes. PMID:27329696

  18. Elastic Plastic Stress Distributions in Weld-bonded Lap Joint under Axial Loading

    Directory of Open Access Journals (Sweden)

    Essam A. Al-Bahkali

    2014-06-01

    Full Text Available Weld-bonding process is increasingly used in many industries such like automobile and aerospace. It offers significant improvements of sheet metal joints in static, dynamic, corrosion, noise resistance, stiffness and impact toughness properties. A full understanding of this process, including the elastic-plastic stress distribution in the joint, is a must for joints design and automation of manufacturing. Also, the modelling and analysis of this process, though it is complex, proves to be of prime importance. Thus, in this study a systematic experimental and theoretical study employing Finite Element Analysis (FEA is conducted on the weld-bonded joint, fabricated from Austenitic Stainless steel (AISI 304 sheets of 1.00 mm thickness and Epoxy adhesive Araldite 2011, subjected to axial loading. Complete 3-D finite element models are developed to evaluate the normal, shear and triaxial Von Mises stresses distributions across the entire joint, in both the elastic and plastic regions. The, needed quantities and properties, for the FE modelling and analysis, of the base metals and the adhesive, such like the elastic-plastic properties, modulus of elasticity, fracture limit, the nugget and Heat Affected Zones (HAZ properties, etc., are obtained from the experiments. The stress distribution curves obtained are found to be consistent with those obtained from the FE models and in excellent agreement with the experimental and theoretical published data, particularly in the elastic region. Furthermore, the stress distribution curves obtained for the weld-bonded joint display the best uniform smooth distribution curves compared to those obtained for the spot and bonded joint cases. The stress concentration peaks at the edges of the weld-bonded region, are almost eliminated resulting in achieving the strongest joint.

  19. Gill Morphology and Oxygen Diffusion Distance in Juvenile Striped Killifish, Fundulus majalis

    Science.gov (United States)

    McEnroe, M.; Rivera, L.; La Fortune, B.; Miller, A.

    2010-12-01

    Striped killifish (Fundulus majalis) are an important estuarine forage fish. Larvae and juveniles utilize shallow marsh pools which become warm (>30 C) and hypoxic (DO environment we studied gill morphology. Gill surface area (GSA) and oxygen diffusion distance are important parameters for oxygen uptake, as expressed by Fick's Equation for diffusion. To measure these parameters fish (N=20, 20-50 mm TL) were collected from marsh pools and adjacent Long Island Sound in late summer, weighed, and measured. The gills were fixed in Karnovsky’s solution. For scanning electron microscopy (SEM) they were rinsed, dehydrated in a graded ETOH series, and critically point dried, sputter-coated and were observed with ISR-SR-50 SEM. Gill morphology (number of filaments, filament length, lamellar density, and lamellar size) were quantified using SEM. Total gill surface area (GSA) was calculated using the method of Hughes (1984); GSA = L* n* bl where L = sum of filament lengths, n = number of lamellae/mm, and bl = bilateral lamellar surface area. To measure oxygen diffusion distance from water to blood, samples were embedded in Araldite 502/Embed 812 TM plastic medium for transmission electron microscopy (TEM). Stained (uranyl acetate and calcinated lead citrate) thin sections were examined using a FEI/Philips Morgagni 268 transmission electron microscope (TEM). Gill lamellar diffusion distance was measured using the technique of Matey et al., 2008 and found to be low (1.0 µm ± 0.4; mean ± SD; N= 17). Gill structure and oxygen diffusion distance will be compared to other fishes from normoxic and hypoxic environments.

  20. The use of embedded sensors for the monitoring of adhesive joints in marine environments

    Science.gov (United States)

    McGovern, Scott T.; Spinks, Geoffrey M.; Wallace, Gordon G.

    2005-05-01

    A copolymer incorporating polyaniline was used as a sensing medium in the construction of a resistance based humidity sensor. Aniline monomer was polymerised in the presence of poly (butyl acrylate / vinyl acetate) and a copolymer containing polyaniline emeraldine salt was obtained. The sensing medium was then developed by redissolving 1-2 w/w% of the resulting polymer residue in dichloromethane to produce a processable polymer blend solution. Some of this polymer residue was also de-doped in a solution of ammonia, and then washed with distilled water until the waste water had a neutral pH. This residue was then redissolved at 1-2 w/w% in dichloromethane to produce a second processable polymer blend this time containing polyaniline emeraldine base. The final sensor design utilised 125μm polyester insulated platinum wire as conducting electrodes that were dip coated in the emeraldine salt copolymer solution and allowed to dry in a desiccator. The sensor was then dip-coated in a protective barrier layer of the emeraldine base copolymer to prevent over-oxidation and/or de-protonation of the emeraldine salt sensing medium under this coating. The sensors had an overall final thickness of less than 150μm and showed high sensitivity to humidity, low resistance, and good reversibility without hysteresis. Sensors were monitored for 2-probe resistance changes when in contact with water. Calibration curves for each sensor were produced to convert the resistance reading to mass uptake of water. Individual sensors were embedded within Aluminium 5083 / Araldite 2015 adhesive joints to monitor mass uptake of water when exposed to marine environments. Correlations between mass uptake of water and joint strength were made. There are various advantages of such a sensor design. Polymer based thin film humidity sensors have the advantage that the high processability of the material allows for simple fabrication of a range of geometries including smaller sensor designs. The ease of

  1. Dorsal raphe nucleus of brain in the rats flown in space inflight and postflight alteration of structure

    Science.gov (United States)

    Krasnov, I.

    The structure of brain dorsal raphe nucleus (DRN) was studied in the rats flown in space aboard Space Shuttle "Columbia" (STS-58, SLS-2 program) and dissected on day 13 of the mission ("inflight" rats) and in 5-6 hours after finishing 14-day flight ("postflight" rats). The brain of "inflight" rats were excised after decapitation, sectioned sagitally halves of brain were fixed by immersion in 2,5 % glutaraldehyde in 0.1 M cacodylate buffer pH 7.3 at 4°C and kept in the flight at 4°C. After landing the brain frontal 0.5 mm sections from DRN area were osmificated and embedded in araldite at NASA ARC. The brains of "postflight": and control rats were underwent to the same procedure. Electronmicroscopical analysis, computer morphometry and glial cell count were performed at Moscow. In DRN neuropil of "inflight" rats the most part of axo-dendritic synapses were surrounded by glia cell processes and had decreased electron density of pre- and postsynaptic membrane and pronounced diminution of synaptic vesicle amount while dendrites were characterized by decrease in matrix electron density and microtubule quantity that in total indicates the decline of afferent flow reaching DRN neurons in microgravity. In DRN neurons of "inflight" rats all mitochondria were characterized by evenly increased dimensions, decreased matrix electron density, small amount of short and far- between located cristae and enlarged intermembrane and intercristae spaces, that in total points out low level of coupling of oxidation to phosphorilation, decrease in energy supply of neuron. Amount of ribosome in cytoplasm was significantly decreased indicating lower lever of biosynthetic processes. The last is supported by diminished dimensions of neuronal body, nucleus and nucleolus (place of r RNA synthesis), cross section area of that were reduced in DRN neurons of "inflight" rats by 18.8 % (p < 0.01), 11.1 % and 26.6 % (p <0,005) correspondingly. Ultrastructure and dimensions of intracellular

  2. CA.C.I.U.S.: Ultrasonic C imaging camera. Contribution to its study and its realization

    International Nuclear Information System (INIS)

    CA.C.I.U.S. is a dynamic imaging three-dimensional echographic camera. This device provides automatic C images which are frontal slices, orthogonal to the ultrasonic propagation. The detector has a cylindrical shape, its focal length of 250 mm and its size is 220 x 143 mm. The useful field is less large (170 x 143 mm) regarding the impossibility to use entirely the 73 elements electronic pattern on the edges. The emitting array is done in two parts. These two parts. The receiver is an electronically focused mono-dimensional array made of 147 elements (0,8 x 5 mm2) spaced 0,7 mm apart, placed between the emitting arrays. These two arrays contain 22 strips of ten bent transducers (10 x 13,7 mm2). The receiver elements are protected form the water of the tank by a loaded araldite layer of λ/4 thickness which allows a better uniformity response with the reception angle. The array elements are matched to 2.2 MHz, the basking is made of a multilayer plastic material (CELORON). This device allows a geometric focalization of the emission. The thickness of each slice C is 2 ± 0,5 cm, depending on its place in the frontal place (better in the center) and on the weighing factors adjusted at the back of the emitting array. The spatial resolution is 1.5 mm (F. W.H.M.) in the two axis orthogonal to the ultrasonic propagation. Several receivers were made. The electronic pattern was optimized by computer study, its results showed an improving of the image definition. Logarithmic amplifiers were used behind each element to allow simultaneous analysis of small echoes coming from the tissue itself and big boundary echoes. The array was placed in a tank filled with water closed by a double membrane. The visualization was obtained in a grey scale dynamic memory. Several emission reception synchronizations were studied. The slowest mode (1 image by second) gave the best signal on noise ratio. CA.C.I.U.S. demonstrates the reality of the slow dynamic C echography and the necessity of a

  3. Hydroxyl and calcium ions diffusion from endodontic materials through roots of primary teeth - in vitro study Avaliação in vitro da difusão de íons Ca+2 e OH- de materiais endodônticos em dentes decíduos

    Directory of Open Access Journals (Sweden)

    Ana Cristina Gerent Petry Nunes

    2005-06-01

    Full Text Available The purpose of this research was to evaluate the diffusion of calcium (Ca+2 and hydroxyl (OH- ions from materials with a calcium hydroxide base - Ca(OH2 through the intact roots of deciduous teeth. This diffusion of ions is important for periapical healing. Forty-six deciduous teeth were selected and instrumented to their working length with #40 files. The teeth were washed during cleaning and shaping with a 1% sodium hypochlorite (NaOCl solution. The canals were dried with paper points. The teeth were divided into 4 groups based on the sealer type, with 10 specimens in each group. A fifth group of 6 teeth without sealer constituted the control group. The materials used as sealers were: Ca(OH2 paste associated to propylene glycol (CaPE thickened at the proportion of 2:1 w/v; UFSC (Federal University of Santa Catarina paste - a mixture of 0.3g of zinc oxide with 0.3g of Ca(OH2 with 0.2ml of olive oil 1:1 w/w; Vitapex® and Sealapex®. The coronal access was sealed with a glass ionomer after the root had been filled with each sealer. A one-third apical surface and foramen was hard-pressed with Araldite®. The teeth were stored individually in flasks containing saline solution at 37ºC and 100% humidity. The OH- and Ca+2 ions diffusion levels were determined using a pH meter and an atomic absorption spectrometer. Data were collected at 48 hours and at intervals of 7, 30, 45 and 60 days. Statistical analysis was performed using ANOVA to compare groups. In the pH evaluation, the CaPE group presented the largest OH- ions diffusion, which peaked at sixty days (p=0.0309, when compared to the other groups (pO objetivo desta pesquisa foi avaliar a difusão de íons Ca+2 e OH- de materiais endodônticos a base hidróxido de cálcio - Ca(OH2, através da raiz intacta de dentes decíduos. 46 dentes decíduos foram selecionados e instrumentados em seu comprimento de trabalho até a lima # 40, e irrigados durante o preparo com solução de hipoclorito de s

  4. Degradation processes and consolidation of Late Jurassic sandstone dinosaur tracks in museum environment (Museum of Lourinhã, Portugal)

    Science.gov (United States)

    Leal, Sofia; mateus, Octavio; Tomas, Carla; Dionisio, Amelia

    2014-05-01

    The current study aims to conciliate conservation and restoration museology diagnosis with paleontological and geological curational needs and has, as subject of study, dinosaur footprints (vertebrates fossils). The footprints have been being exposed since 2004 in the paleontology hall of the Museum of Lourinhã, Portugal, and are part of a important paleontological collection of Late Jurassic vertebrate fossils from Lourinhã Formation. Presently, it is considered a unique heritage in danger of disappearing due to high decay level of disaggregation of its geological structure. The dinosaur footprints, (ML557) found, more precisely, on a coastline cliff in Lourinhã, Porto das Barcas, Lagido do Forno (coordinate 39° 14. 178'N, 9° 20. 397'W), Jurassic period, on the 5th of June 2001, by Jesper Milàn. This cliff of high slope presents sedimentary stratigraphic characteristics of a sandstone/siltstone of gray and red colors, by the '' Munsell scale and Color Chart''. Geological the tracks are Late Jurassic in age, and colected in the Lourinhã Formation, Praia Azul Member, of the Lusitanian Basin. There are three natural infills tridactyl tracks, possibly ascribed to ornithopod, a bipedal herbivore, resultant of a left foot movement, right and left. Footprints have 300-400mm of wide and 330-360mm of height with round fingers, which are elongated due to some degradation/erosion. In 2001, the footprints were collected from the field, cleaned, consolidated and glued in the laboratory of the Museum of Lourinhã before being exhibited in a museum display. Stone matrix was removed and a consolidation product applied, probably a polyvinyl acetate, of the brand Plexigum. The footprint with broken central digit was glued with an epoxy resin, Araldite. Both applied products were confirmed by analysis of µ-FTIR (Fourier Transform Infrared Spectroscopy) and both presented colour change and detachment surface problems. After collecting and storing, in 2004, footprints were

  5. Processing-property relationships in epoxy resin/titanium dioxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Polyzos, Georgios [ORNL; Tuncer, Enis [ORNL; Sauers, Isidor [ORNL; More, Karren Leslie [ORNL

    2010-01-01

    In situ precipitated titanium dioxide nanoparticles improve the physical properties of polymer composites. Since the pioneering work at Toyota Research Center on exfoliated montmorillonite nanoparticles in a nylon matrix, extensive studies have been performed on polymer nanocomposites in an effort to better integrate organic and inorganic phases. Inorganic fillers, such as silicon and titanium oxides, are widely used because of their remarkable enhancement of the mechanical, electrical, barrier, and flame-retardancy properties of organic polymers. The dispersion and size of the fillers determine the performance of nanocomposites and, despite numerous methods and processing conditions reported in the literature, a universally simple method to scale up the distribution of nanofillers remains a challenge. A significant part of our research involves formulation of novel nanodielectrics that can withstand high electric fields and exhibit superior mechanical performance. Focusing on nanocomposites operating at cryogenic temperatures, our group developed an in situ method for nucleating titanium dioxide (TiO{sub 2}) nanoparticles in polyvinyl alcohol. We also applied this method to a variety of polymer matrices. Here, we present our recent work on a cryogenic resin filled with TiO{sub 2} nanoparticles. Using a particle-precursor solution from which TiO{sub 2} precipitates, we nucleated nanoparticles within the cryogenic epoxy resin Araldite 5808 (Huntsman Advanced Materials Inc., USA). We fabricated nanocomposite films at low weight percentages ({approx}2.5%) to avoid formation of large aggregates and interfaces. The morphology and dispersion of the in situ synthesized nanoparticles are shown by low- and high-magnification transmission-electron-microscopy (TEM) images. The TiO{sub 2} particles ({le}5nm in diameter) are uniformly nucleated and form evenly distributed nanometer-sized clusters in the polymer matrix. This morphology differs significantly from nanocomposites