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Sample records for self-constructed teflon mould

  1. Conditions for mould growth on typical interior surfaces

    DEFF Research Database (Denmark)

    Møller, Eva B.; Andersen, Birgitte; Rode, Carsten

    2017-01-01

    Prediction of the risk for mould growth is an important parameter for the analysis and design of the hygrothermal performance of building constructions. However, in practice the mould growth does not always follow the predicted behavior described by the mould growth models. This is often explained...... by uncertainty in the real conditions of exposure. In this study, laboratory experiments were designed to determine mould growth at controlled transient climate compared to growth at constant climate. The experiment included three building materials with four different surface treatments. The samples were...

  2. Teflon/SiO₂ Bilayer Passivation for Improving the Electrical Reliability of Oxide TFTs Fabricated Using a New Two-Photomask Self-Alignment Process.

    Science.gov (United States)

    Fan, Ching-Lin; Shang, Ming-Chi; Li, Bo-Jyun; Lin, Yu-Zuo; Wang, Shea-Jue; Lee, Win-Der; Hung, Bohr-Ran

    2015-04-13

    This study proposes a two-photomask process for fabricating amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) that exhibit a self-aligned structure. The fabricated TFTs, which lack etching-stop (ES) layers, have undamaged a-IGZO active layers that facilitate superior performance. In addition, we demonstrate a bilayer passivation method that uses a polytetrafluoroethylene (Teflon) and SiO₂ combination layer for improving the electrical reliability of the fabricated TFTs. Teflon was deposited as a buffer layer through thermal evaporation. The Teflon layer exhibited favorable compatibility with the underlying IGZO channel layer and effectively protected the a-IGZO TFTs from plasma damage during SiO₂ deposition, resulting in a negligible initial performance drop in the a-IGZO TFTs. Compared with passivation-free a-IGZO TFTs, passivated TFTs exhibited superior stability even after 168 h of aging under ambient air at 95% relative humidity.

  3. ATR FT-IR spectroscopy on Vmh2 hydrophobin self-assembled layers for Teflon membrane bio-functionalization

    International Nuclear Information System (INIS)

    Portaccio, M.; Gravagnuolo, A.M.; Longobardi, S.; Giardina, P.; Rea, I.; De Stefano, L.; Cammarota, M.; Lepore, M.

    2015-01-01

    Graphical abstract: - Highlights: • Hydrophobin self-assembled layers on Teflon in different preparation conditions were investigated. • ATR collection data geometry allowed samples examination without any particular preparation. • Amide content, lipid/amide and carbohydrate/amide ratios of the protein layer were estimated. • Secondary structure of protein was determined for the examined samples. • FT-IR demonstrated to be of extreme relevance in monitoring hydrophobin self-assembled layers preparation. - Abstract: Surface functionalization by layers of hydrophobins, amphiphilic proteins produced by fungi offers a promising and green strategy for fabrication of biomedical and bioanalytical devices. The layering process of the Vmh2 hydrophobin from Pleurotus ostreatus on Teflon membrane has been investigated by Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) spectroscopy. In particular, protein layers obtained with hydrophobin purified with two different procedures and in various coating conditions have been examined. The layers have been characterized by quantifying the amide I and amide II band area together with the lipid/amide ratio and carbohydrate/amide ratio. This characterization can be very useful in evaluating the best purification strategy and coating conditions. Moreover the analysis of the secondary structure of the layered protein using the deconvolution procedure of amide I band indicate the prevalent contribution from β-sheet state. The results inferred by infrared spectroscopy have been also confirmed by scanning electron microscopy imaging

  4. ATR FT-IR spectroscopy on Vmh2 hydrophobin self-assembled layers for Teflon membrane bio-functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Portaccio, M., E-mail: marianna.portaccio@unina2.it [Dipartimento di Medicina Sperimentale – Seconda Università di Napoli, Via S.M. di Costantinopoli, 16-80134 Napoli (Italy); Gravagnuolo, A.M., E-mail: alfredomaria.gravagnuolo@unina.it [Dipartimento di Scienze Chimiche, Università “Federico II”, Via Cintia, 21- 80126 Napoli (Italy); Longobardi, S., E-mail: sara.longobardi@unina.it [Dipartimento di Scienze Chimiche, Università “Federico II”, Via Cintia, 21- 80126 Napoli (Italy); Giardina, P., E-mail: paola.giardina@unina.it [Dipartimento di Scienze Chimiche, Università “Federico II”, Via Cintia, 21- 80126 Napoli (Italy); Rea, I., E-mail: ilaria.rea@na.imm.cnr.it [Institute for Microelectronics and Microsystems, CNR, Via P. Castellino, 111-80131 Napoli (Italy); De Stefano, L., E-mail: luca.destefano@na.imm.cnr.it [Institute for Microelectronics and Microsystems, CNR, Via P. Castellino, 111-80131 Napoli (Italy); Cammarota, M., E-mail: marcella.cammarota@unina2.it [Dipartimento di Medicina Sperimentale – Seconda Università di Napoli, Via S.M. di Costantinopoli, 16-80134 Napoli (Italy); Lepore, M., E-mail: maria.lepore@unina2.it [Dipartimento di Medicina Sperimentale – Seconda Università di Napoli, Via S.M. di Costantinopoli, 16-80134 Napoli (Italy)

    2015-10-01

    Graphical abstract: - Highlights: • Hydrophobin self-assembled layers on Teflon in different preparation conditions were investigated. • ATR collection data geometry allowed samples examination without any particular preparation. • Amide content, lipid/amide and carbohydrate/amide ratios of the protein layer were estimated. • Secondary structure of protein was determined for the examined samples. • FT-IR demonstrated to be of extreme relevance in monitoring hydrophobin self-assembled layers preparation. - Abstract: Surface functionalization by layers of hydrophobins, amphiphilic proteins produced by fungi offers a promising and green strategy for fabrication of biomedical and bioanalytical devices. The layering process of the Vmh2 hydrophobin from Pleurotus ostreatus on Teflon membrane has been investigated by Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) spectroscopy. In particular, protein layers obtained with hydrophobin purified with two different procedures and in various coating conditions have been examined. The layers have been characterized by quantifying the amide I and amide II band area together with the lipid/amide ratio and carbohydrate/amide ratio. This characterization can be very useful in evaluating the best purification strategy and coating conditions. Moreover the analysis of the secondary structure of the layered protein using the deconvolution procedure of amide I band indicate the prevalent contribution from β-sheet state. The results inferred by infrared spectroscopy have been also confirmed by scanning electron microscopy imaging.

  5. Teflon/SiO2 Bilayer Passivation for Improving the Electrical Reliability of Oxide TFTs Fabricated Using a New Two-Photomask Self-Alignment Process

    Science.gov (United States)

    Fan, Ching-Lin; Shang, Ming-Chi; Li, Bo-Jyun; Lin, Yu-Zuo; Wang, Shea-Jue; Lee, Win-Der; Hung, Bohr-Ran

    2015-01-01

    This study proposes a two-photomask process for fabricating amorphous indium–gallium–zinc oxide (a-IGZO) thin-film transistors (TFTs) that exhibit a self-aligned structure. The fabricated TFTs, which lack etching-stop (ES) layers, have undamaged a-IGZO active layers that facilitate superior performance. In addition, we demonstrate a bilayer passivation method that uses a polytetrafluoroethylene (Teflon) and SiO2 combination layer for improving the electrical reliability of the fabricated TFTs. Teflon was deposited as a buffer layer through thermal evaporation. The Teflon layer exhibited favorable compatibility with the underlying IGZO channel layer and effectively protected the a-IGZO TFTs from plasma damage during SiO2 deposition, resulting in a negligible initial performance drop in the a-IGZO TFTs. Compared with passivation-free a-IGZO TFTs, passivated TFTs exhibited superior stability even after 168 h of aging under ambient air at 95% relative humidity. PMID:28788026

  6. Teflon/SiO2 Bilayer Passivation for Improving the Electrical Reliability of Oxide TFTs Fabricated Using a New Two-Photomask Self-Alignment Process

    Directory of Open Access Journals (Sweden)

    Ching-Lin Fan

    2015-04-01

    Full Text Available This study proposes a two-photomask process for fabricating amorphous indium–gallium–zinc oxide (a-IGZO thin-film transistors (TFTs that exhibit a self-aligned structure. The fabricated TFTs, which lack etching-stop (ES layers, have undamaged a-IGZO active layers that facilitate superior performance. In addition, we demonstrate a bilayer passivation method that uses a polytetrafluoroethylene (Teflon and SiO2 combination layer for improving the electrical reliability of the fabricated TFTs. Teflon was deposited as a buffer layer through thermal evaporation. The Teflon layer exhibited favorable compatibility with the underlying IGZO channel layer and effectively protected the a-IGZO TFTs from plasma damage during SiO2 deposition, resulting in a negligible initial performance drop in the a-IGZO TFTs. Compared with passivation-free a-IGZO TFTs, passivated TFTs exhibited superior stability even after 168 h of aging under ambient air at 95% relative humidity.

  7. Optimisation of multi-layer rotationally moulded foamed structures

    Science.gov (United States)

    Pritchard, A. J.; McCourt, M. P.; Kearns, M. P.; Martin, P. J.; Cunningham, E.

    2018-05-01

    Multi-layer skin-foam and skin-foam-skin sandwich constructions are of increasing interest in the rotational moulding process for two reasons. Firstly, multi-layer constructions can improve the thermal insulation properties of a part. Secondly, foamed polyethylene sandwiched between solid polyethylene skins can increase the mechanical properties of rotationally moulded structural components, in particular increasing flexural properties and impact strength (IS). The processing of multiple layers of polyethylene and polyethylene foam presents unique challenges such as the control of chemical blowing agent decomposition temperature, and the optimisation of cooling rates to prevent destruction of the foam core; therefore, precise temperature control is paramount to success. Long cooling cycle times are associated with the creation of multi-layer foam parts due to their insulative nature; consequently, often making the costs of production prohibitive. Devices such as Rotocooler®, a rapid internal mould water spray cooling system, have been shown to have the potential to significantly decrease cooling times in rotational moulding. It is essential to monitor and control such devices to minimise the warpage associated with the rapid cooling of a moulding from only one side. The work presented here demonstrates the use of threaded thermocouples to monitor the polymer melt in multi-layer sandwich constructions, in order to analyse the cooling cycle of multi-layer foamed structures. A series of polyethylene skin-foam test mouldings were produced, and the effect of cooling medium on foam characteristics, mechanical properties, and process cycle time were investigated. Cooling cycle time reductions of 45%, 26%, and 29% were found for increasing (1%, 2%, and 3%) chemical blowing agent (CBA) amount when using internal water cooling technology from ˜123°C compared with forced air cooling (FAC). Subsequently, a reduction of IS for the same skin-foam parts was found to be 1%, 4

  8. Enhancement of the CIGS solar cell's efficiency by anti-reflection coating with teflon AF

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Hong-Sub; Kim, Chan; Rhee, Il-Su [Kyungpook National University, Daegu (Korea, Republic of); Jo, Hyun-Jun; Kim, Dae-Hwan [Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of); Hong, Sung-Wook [Daegu University, Gyeongsan (Korea, Republic of)

    2014-11-15

    An anti-reflection (AR) layer of Teflon AF was deposited on the front surface of a Cu(In,Ga)Se{sub 2} (CIGS) solar cell with a structure of grid/TCO/ZnO/CdS/Cu(In,Ga)Se{sub 2}/Mo/glass by using the spin coating method. This AR layer reduced the front-surface reflection, which resulted in high efficiency for the CIGS solar cell. The thickness of the Teflon AF layer was varied to determine the thickness that gave the highest transmittance of incident light into the active absorber of the CIGS solar cell. The optimum thickness of the Teflon AF layer was found to be 105 nm. CIGS solar cells with a Teflon AF layer of 105 nm were constructed, and their efficiencies were compared with those of solar cells without a Teflon AF layer. The average increase in the relative efficiency of the solar cells was 2.63% due to the inclusion of an anti-reflection layer of Teflon AF.

  9. Mould growth on building materials

    DEFF Research Database (Denmark)

    Fog Nielsen, K.

    Mould growth in buildings is associated with adverse health effects among the occupants of the building. However actual growth only occurs in damp and water-damaged materials, and is an increasing problem in Denmark, due to less robust constructions, inadequate maintenance, and too little...

  10. Elasticity of Moulding Sands – a Method of Reducing Core Cracking

    Directory of Open Access Journals (Sweden)

    Dobosz St. M.

    2017-03-01

    Full Text Available This paper focuses on mechanical properties of self hardening moulding sands with furfuryl and alkyd binders. Elasticity as a new parameter of moulding sands is investigated. With the use of presented testing equipment, it is possible to determine force kinetics and deformation of moulding sand in real time. The need for this kind of study comes from the modern casting industry. New foundries can be characterized with high intensity of production which is correlated with high level of mechanization and automatization of foundry processes. The increasingly common use of manipulators in production of moulds and cores can lead to generation of new types of flaws, caused by breakage in moulds and cores which could occur during mould assembly. Hence it is required that moulds and cores have high resistance to those kinds of factors, attributing it with the phenomenon of elasticity. The article describes the theoretical basis of this property, presents methods of measuring and continues earlier research.

  11. Teflon pastille use in high dose dosimetry; Utilizacao de pastilhas de teflon em dosimetria de doses altas

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Maria Ines [Associacao Educacional Nove de Julho (UNINOVE), Sao Paulo, SP (Brazil); Caldas, Linda V.E., E-mail: miteixeira@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    This paper study the Teflon, which is used as aglomerant in the confection of dosimetric pastilles, for the viabilization of this material as high dose dosimeter. This paper used the OSL technique for the characterization of dosimetric properties of Teflon. The doses-response curve has been obtained for {sup 60}Co radiation between 100 Gy and 50 kGy, and the OSL answer reproducibility. The preliminary results shown that the Teflon is a material which can be used for high dose dosimetry

  12. Two Component Injection Moulding for Moulded Interconnect Devices

    DEFF Research Database (Denmark)

    Islam, Aminul

    component (2k) injection moulding is one of the most industrially adaptive processes. However, the use of two component injection moulding for MID fabrication, with circuit patterns in sub-millimeter range, is still a big challenge. This book searches for the technical difficulties associated...... with the process and makes attempts to overcome those challenges. In search of suitable polymer materials for MID applications, potential materials are characterized in terms of polymer-polymer bond strength, polymer-polymer interface quality and selective metallization. The experimental results find the factors...... which can effectively control the quality of 2k moulded parts and metallized MIDs. This book presents documented knowledge about MID process chains, 2k moulding and selective metallization which can be valuable source of information for both academic and industrial users....

  13. Normalization in Lie algebras via mould calculus and applications

    Science.gov (United States)

    Paul, Thierry; Sauzin, David

    2017-11-01

    We establish Écalle's mould calculus in an abstract Lie-theoretic setting and use it to solve a normalization problem, which covers several formal normal form problems in the theory of dynamical systems. The mould formalism allows us to reduce the Lie-theoretic problem to a mould equation, the solutions of which are remarkably explicit and can be fully described by means of a gauge transformation group. The dynamical applications include the construction of Poincaré-Dulac formal normal forms for a vector field around an equilibrium point, a formal infinite-order multiphase averaging procedure for vector fields with fast angular variables (Hamiltonian or not), or the construction of Birkhoff normal forms both in classical and quantum situations. As a by-product we obtain, in the case of harmonic oscillators, the convergence of the quantum Birkhoff form to the classical one, without any Diophantine hypothesis on the frequencies of the unperturbed Hamiltonians.

  14. Ink-jet printing technology enables self-aligned mould patterning for electroplating in a single step

    International Nuclear Information System (INIS)

    Meissner, M V; Spengler, N; Mager, D; Wang, N; Kiss, S Z; Höfflin, J; While, P T; Korvink, J G

    2015-01-01

    We present a new self-aligned, mask-free micro-fabrication method with which to form thick-layered conductive metal micro-structures inside electroplating moulds. Seed layer patterning for electroplating was performed by ink-jet printing using a silver nano-particle ink deposited on SU-8 or Ordyl SY permanent resist. The silver ink contact angle on SU-8 was adjusted by oxygen plasma followed by a hard bake. Besides functioning as a seed layer, the printed structures further served as a shadow mask during patterning of electroplating moulds into negative photoresist. The printed silver tracks remained in strong adhesion to the substrate when exposed to the acidic chemistry of the electroplating bath. To demonstrate the process, we manufactured rectangular, low-resistivity planar micro-coils for use in magnetic resonance microscopy. MRI images of a spring onion with an in-plane resolution down to 10 µm × 10 µm were acquired using a micro-coil on an 11.7 T MRI scanner. (paper)

  15. Hot Embossing for Whole Teflon Superhydrophobic Surfaces

    Directory of Open Access Journals (Sweden)

    Jie Li

    2018-06-01

    Full Text Available In this paper, we report a simple fabrication process of whole Teflon superhydrophobic surfaces, featuring high-aspect-ratio (>20 nanowire structures, using a hot embossing process. An anodic aluminum oxide (AAO membrane is used as the embossing mold for the fabrication of high-aspect-ratio nanowires directly on a Teflon substrate. First, high-aspect-ratio nanowire structures of Teflon are formed by pressing a fluorinated ethylene propylene (FEP sheet onto a heated AAO membrane at 340 °C, which is above the melting point of FEP. Experimental results show that the heating time and aspect ratios of nanopores in the AAO mold are critical to the fidelity of the hot embossed nanowire structures. It has also been found that during the de-molding step, a large adhesive force between the AAO mold and the molded FEP greatly prolongs the length of nanowires. Contact angle measurements indicate that Teflon nanowires make the surface superhydrophobic. The reliability and robustness of superhydrophobicity is verified by a long-term (~6.5 h underwater turbulent channel flow test. After the first step of hot-embossing the Teflon nanowires, microstructures are further superimposed by repeating the hot embossing process, but this time with microstructured silicon substrates as micromolds and at a temperature lower than the melting temperature of the FEP. The results indicate that the hot embossing process is also an effective way to fabricate hierarchical micro/nanostructures of whole Teflon, which can be useful for applications of Teflon material, such as superhydrophobic surfaces.

  16. Injection moulding of optical functional micro structures using laser structured, PVD-coated mould inserts

    Energy Technology Data Exchange (ETDEWEB)

    Hopmann, Ch.; Weber, M.; Schöngart, M.; Schäfer, C., E-mail: weber@ikv-aachen.de [Institute of Plastics Processing (IKV) at RWTH Aachen University (Germany); Bobzin, K.; Bagcivan, N.; Brögelmann, T.; Theiß, S.; Münstermann, T. [Surface Engineering Institute (IOT), RWTH Aachen University, Aachen (Germany); Steger, M. [Fraunhofer Institute for Laser Technology (ILT), Aachen (Germany)

    2015-05-22

    Micro structured optical plastics components are intensively used i. e. in consumer electronics, for optical sensors in metrology, innovative LED-lighting or laser technology. Injection moulding has proven to be successful for the large-scale production of those parts. However, the production of those parts still causes difficulties due to challenges in the moulding and demoulding of plastics parts created with laser structured mould inserts. A complete moulding of the structures often leads to increased demoulding forces, which then cause a breaking of the structures and a clogging of the mould. An innovative approach is to combine PVD-coated (physical vapour deposition), laser structured inserts and a variothermal moulding process to create functional mic8iüro structures in a one-step process. Therefore, a PVD-coating is applied after the laser structuring process in order to improve the wear resistance and the anti-adhesive properties against the plastics melt. In a series of moulding trials with polycarbonate (PC) and polymethylmethacrylate (PMMA) using different coated moulds, the mould temperature during injection was varied in the range of the glass transition and the melt temperature of the polymers. Subsequently, the surface topography of the moulded parts is evaluated by digital 3D laser-scanning microscopy. The influence of the moulding parameters and the coating of the mould insert on the moulding accuracy and the demoulding behaviour are being analysed. It is shown that micro structures created by ultra-short pulse laser ablation can be successfully replicated in a variothermal moulding process. Due to the mould coating, significant improvements could be achieved in producing micro structured optical plastics components.

  17. Study of teflon pads as high doses dosemeters

    International Nuclear Information System (INIS)

    Teixeira, Maria Ines; Caldas, Linda V.E.

    2013-01-01

    The aim of this work is to study the Teflon, which is used as a binder in the manufacture of dosimetric tablets, for the feasibility of this material as high dose dosemeter. In this paper we used the technique of thermally stimulated luminescence (OSL) to characterize the dosimetric properties of Teflon. Teflon samples were exposed to different doses of radiation, using a source of gamma radiation ( 60 Co). It was obtained dose-response curve between 100 Gy to 50 kGy and reproducibility of OSL response. The preliminary results show that Teflon is a useful material to high dose dosimetry

  18. Flexible Mould for Precast Concrete Elements

    DEFF Research Database (Denmark)

    Jepsen, Christian Raun; Kristensen, Mathias Kræmmergaard; Kirkegaard, Poul Henning

    2010-01-01

    The present paper describes the development of a digitally controlled mou Id that forms a double curved and fair surface directly from the digital CAD model. The primary motivation for the development of the mould is to reduce the cost of constructing double curved, cast elements for architecture...

  19. Computational design of mould sprue for injection moulding thermoplastics

    Directory of Open Access Journals (Sweden)

    Muralidhar Lakkanna

    2016-01-01

    Full Text Available To injection mould polymers, designing mould is a key task involving several critical decisions with direct implications to yield quality, productivity and frugality. One prominent decision among them is specifying sprue-bush conduit expansion as it significantly influences overall injection moulding; abstruseness anguish in its design criteria deceives direct determination. Intuitively designers decide it wisely and then exasperate by optimising or manipulating processing parameters. To overwhelm that anomaly this research aims at proposing an ideal design criteria holistically for all polymeric materials also tend as a functional assessment metric towards perfection i.e., criteria to specify sprue conduit size before mould development. Accordingly, a priori analytical criterion was deduced quantitatively as expansion ratio from ubiquitous empirical relationships specifically a.k.a an exclusive expansion angle imperatively configured for injectant properties. Its computational intelligence advantage was leveraged to augment functionality of perfectly injecting into an impression gap, while synchronising both injector capacity and desired moulding features. For comprehensiveness, it was continuously sensitised over infinite scale as an explicit factor dependent on in-situ spatio-temporal injectant state perplexity with discrete slope and altitude for each polymeric character. In which congregant ranges of apparent viscosity and shear thinning index were conceived to characteristically assort most thermoplastics. Thereon results accorded aggressive conduit expansion widening for viscous incrust, while a very aggressive narrowing for shear thinning encrust; among them apparent viscosity had relative dominance. This important rationale would certainly form a priori design basis as well diagnose filling issues causing several defects. Like this the proposed generic design criteria, being simple would immensely benefit mould designers besides serve

  20. Mould thermal monitoring: a window on the mould

    Energy Technology Data Exchange (ETDEWEB)

    Normanton, A.S.; Hewitt, P.N.; Hunter, N.S.; Scoones, D.; Harris, B.

    2004-07-01

    Corus R, D and T at Teesside Technology Centre has developed over a number of years a mould thermal monitoring (MTM) system based on an array of thermocouples in the mould copper plates. The system is installed on the Corus slab casters in the UK, on slab casters at Outokumpu (UK), Sidmar (Belgium) and Kosice (Slovakia) and, at the time of the 4th European Continuous Casting Conference, was also on the medium thickness slab caster at Tuscaloosa (USA), which was sold to Nucor in 2004. The MTM system was also under development on the thin slab caster at Trico (USA) before plant closure (subsequently bought by Nucor), and aspects are currently being developed on the Corus DSP (direct sheet plant) thin slab caster at IJmuiden (The Netherlands). While a prime function is detection and prevention of sticker type breakouts, the MTM system allows real time assessment of thermal conditions, provides a valuable input for online grading and, most important, enables modifications to mould powder practices to be assessed. The present paper briefly outlines recent developments to the MTM system and presents examples of the use of the system to assist mould powder developments. (author)

  1. ADHESION AND SPREADING OF HUMAN FIBROBLASTS ON SUPERHYDROPHOBIC FEP-TEFLON

    NARCIS (Netherlands)

    BUSSCHER, HJ; STOKROOS, [No Value; GOLVERDINGEN, JG; SCHAKENRAAD, JM

    1991-01-01

    Adhesion and spreading of human fibroblasts was studied on hydrophobized and hydrophilized FEP-Teflon, and compared with adhesion and spreading on untreated FEP-Teflon and Tissue culture polystyrene (TCPS). Superhydrophobic FEP-Teflon was prepared by ion etching followed by oxygen glow-discharge.

  2. Radon daughter plate-out onto Teflon

    Science.gov (United States)

    Morrison, E. S.; Frels, T.; Miller, E. H.; Schnee, R. W.; Street, J.

    2018-01-01

    Radiopure materials for detector components in rare event searches may be contaminated after manufacturing with long-lived 210Pb produced by the decay of atmospheric radon. Charged radon daughters deposited on the surface or implanted in the bulk of detector materials have the potential to cause noticeable backgrounds within dark matter regions of interest. Understanding the mechanics governing these background signals is therefore a paramount concern in dark matter experiments in order to distinguish a real signal from internal detector backgrounds. Teflon (i.e. PTFE) is a specific material of interest because it makes up the walls of the inner detector of many liquid noble detectors such as the LUX-ZEPLIN experiment. The rate of radon daughter plate-out onto Teflon can be orders of magnitude larger than the plate-out rate onto other materials. Mitigation of plate-out onto Teflon and steel by proximity to other materials is demonstrated.

  3. SU-E-T-04: 3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions

    International Nuclear Information System (INIS)

    Cumming, I; Lasso, A; Rankin, A; Fichtinger, G; Joshi, C P; Falkson, C; Schreiner, L John

    2014-01-01

    Purpose: Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions. Methods: We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer ( http://www.slicer.org ) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement. A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material. Results: The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm. Conclusion: Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required

  4. SU-E-T-04: 3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Cumming, I; Lasso, A; Rankin, A; Fichtinger, G [Laboratory for Percutaneous Surgery, School of Computing, Queen' s University, Kingston, Ontario (Canada); Joshi, C P; Falkson, C; Schreiner, L John [CCSEO, Kingston General Hospital and Department of Oncology, Queen' s University, Kingston, Ontario (Canada)

    2014-06-01

    Purpose: Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions. Methods: We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer ( http://www.slicer.org ) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement. A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material. Results: The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm. Conclusion: Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required

  5. Process Condition Monitoring of Micro Moulding Using a Two-plunger Micro Injection Moulding Machine

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Guerrier, Patrick

    2010-01-01

    The influence of micro injection moulding (µIM) process parameters (melt and mould temperature, piston injection speed and stoke length) on the injection pressure was investigated using Design of Experiments. Direct piston injection pressure measurements were performed and data collected using...... a micro injection moulding machine equipped with a two-pluger injection unit. Miniaturized dog-bone shaped speciments on polyoxymethylene (POM) were moulded over a wide range of processing cpnditions in order to characterize the process and assess its capability. Experimental results obtained under...

  6. Micro Injection Moulding

    DEFF Research Database (Denmark)

    Kjær, Erik Michael; Johansen, Bjørn B.; Sørensen, Hans H.

    2000-01-01

    Microstructures were created in SiO2 wafers using RIE and KOH etching. The mould inserts was manufactured by Ni electroplating the wafers. Different types of microstructures were made in the mould; rows of quadratic columns, rows of pyramids and of pyramid stumps. The structures (from the SiO2...

  7. Two component micro injection moulding for moulded interconnect devices

    DEFF Research Database (Denmark)

    Islam, Aminul

    2008-01-01

    Moulded interconnect devices (MIDs) contain huge possibilities for many applications in micro electro-mechanical-systems because of their capability of reducing the number of components, process steps and finally in miniaturization of the product. Among the available MID process chains, two...... component injection moulding is one of the most industrially adaptive processes. However, the use of two component injection moulding for MID fabrication, with circuit patterns in the sub-millimeter range, is still a big challenge at the present state of technology. The scope of the current Ph.D. project...... and a reasonable adhesion between them. • Selective metallization of the two component plastic part (coating one polymer with metal and leaving the other one uncoated) To overcome these two main issues in MID fabrication for micro applications, the current Ph.D. project explores the technical difficulties...

  8. Mould Design and Material selection for Film Insert Moulding of Direct Methanol Fuel Cell Packaging

    DEFF Research Database (Denmark)

    Wöhner, Timo; Senkbeil, S.; Olesen, T. L.

    2015-01-01

    This paper presents the mould design for an injection moulding (IM) process for the production of a methanol container for the use in small, passive Direct Methanol Fuel Cell (DMFC) systems, which are intended to be used in behind-the-ear hearing aid systems. One of the crucial properties...... for the production of containers with different venting area and location of the venting holes and the use of different membrane thicknesses by using the same mould. Mould design and material selection are presented....

  9. The effect of internal mould water spray cooling on rotationally moulded polyethylene parts

    Science.gov (United States)

    McCourt, Mark P.; Kearns, Mark P.; Martin, Peter J.

    2018-05-01

    The conventional method of cooling during the rotational moulding process is through the use of forced air. During the cooling phase of a typical rotomoulding cycle, large volumes of high velocity room temperature air are forced across the outside of the rotating rotomoulding tool to encourage cooling of the metal mould and molten polymer. Since no cooling is applied to the inside of the mould, the inner surface of the polymer (polyethylene) cools more slowly and will have a tendency to be more crystalline and the polyethylene will have a higher density in this region. The side that cools more quickly (in contact with the inside mould wall) will be less crystalline, and will therefore have a lower density. The major consequence of this difference in crystallinity will be a buildup of internal stresses producing warpage and excessive shrinkage of the part with subsequent increased levels of scrap. Therefore excessive cooling on the outside of the mould should be avoided. One consequence of this effect is that the cooling time for a standard rotationally moulded part can be quite long and this has an effect on the overall economics of the process in terms of part manufacture. A number of devices are currently on the market to enhance the cooling of rotational moulding by introducing a water spray to the inside of the rotomoulding during cooling. This paper reports on one such device 'Rotocooler' which during a series of initial industrial trials has been shown to reduce the cycletime by approximately 12 to 16%, with minimal effect on the mechanical properties, leading to a part which has less warpage and shrinkage than a conventionally cooled part.

  10. An Experimental Study on Steel and Teflon Squeeze Film Dampers

    Directory of Open Access Journals (Sweden)

    Asad A. Khalid

    2006-01-01

    Full Text Available In this paper, the vibration analysis on Teflon and steel squeeze film dampers has been carried out. At different frequency ranges, vibration amplitude and the resonance frequency are measured. The eccentricity ratio at resonance speed has been determined. Results show that the vibration amplitude of the steel damper is 10% less at resonance compared with the Teflon damper. On the other hand, saving weight of 36% has been achieved by using the Teflon damper.

  11. Mould insert fabrication of a single-mode fibre connector alignment structure optimized by justified partial metallization

    International Nuclear Information System (INIS)

    Wissmann, Markus; Barié, Nicole; Guttmann, Markus; Schneider, Marc; Kolew, Alexander; Besser, Heino; Pfleging, Wilhelm; Hofmann, Andreas; Van Erps, Jürgen; Beri, Stefano; Watté, Jan

    2015-01-01

    For mass production of multiscale-optical components, microstructured moulding tools are needed. Metal tools are used for hot embossing or injection moulding of microcomponents made of a thermoplastic polymer. Microstructures with extremely tight specifications, e.g. low side wall roughness and high aspect ratios are generally made by lithographic procedures such as x-ray lithography or deep proton writing. However, these processes are unsuitable for low-cost mass production. An alternative manufacturing method of moulding tools has been developed at the Karlsruhe Institute of Technology (KIT). This article describes a mould insert fabrication and a new replication process for self-centring fibre alignment structures for low loss field installable single-mode fibre connectors, developed and fabricated by the Vrije Universiteit Brussel (VUB) in collaboration with TE Connectivity. These components are to be used in fibre-to-the-home networks and support the deployment and maintenance of fibre optic links. The special feature of this particular fibre connector is a self-centring fibre alignment, achieved by means of a through hole with deflectable cantilevers acting as micro-springs. The particular challenge is the electroforming of through holes with a centre hole diameter smaller than 125 µm. The fibre connector structure is prototyped by deep proton writing in polymethylmethacrylate and used as a sacrificial part. Using joining, physical vapour deposition and electroforming technology, a negative copy of the prototyped connector is transferred into nickel to be used as a moulding tool. The benefits of this replication technique are a rapid and economical fabrication of moulding tools with high-precision microstructures and a long tool life. With these moulding tools low-cost mass production is possible. We present the manufacturing chain we have established. Each individual manufacturing step of the mould insert fabrication will be shown in this report. The

  12. Moulds and profiles of the building facades of St. Petersburg of the 18th century

    Directory of Open Access Journals (Sweden)

    Voznyak Ekaterina Ryurikovna

    2015-12-01

    Full Text Available In the article the author underlines the importance of details (moulds and profiles for the architects of previous times. The architects of the 17th-19th centuries expressed their creative and filosofic position choosing some concrete example of the great theorists of the past when constructing moulds and orders. We should note that the negative attitude to Classicism theory reasoned in the lack of investigations of the architectural details of the buildings of the 18th-19th centuries, in particular the ones in Saint Petersburg. At the present moment the interest to studying the architectural theories and forms is reappearing both in Russia and in Europe. The article considers the architectural moulds of the eighteenth century buildings of St. Petersburg, examples of their construction in each stylistic period. The analysis shows the significant differences of the Russian moulds drawings from the recommendations of classical treatises of the Renaissance and educational counterparts. The author offers the basic analysis of the characteristic features and data elements for each stylistic period in the architecture of St. Petersburg of the 18th century, as well as a unique handwriting of the architects who worked in that era.

  13. MouldingSandDB – a modern database storing moulding sands properties research results

    Directory of Open Access Journals (Sweden)

    J. Jakubski

    2011-01-01

    Full Text Available The complexity of foundry processes requires the use of modern, advanced IT tools for optimization, storage and analysis of t echnicaldata. Properties of moulding and core sands that are collected in research laboratories, manufacturers, and finally in the foundries, are not in use later on. It seems important to create a database that will allow to use the results stored, along with the possibility of searching according to set criteria, adjusted to casting practice. This paper presents part of the database named „MouldingSandDB”, which allows to collect and search data for synthetic moulding sands.

  14. Surface Microstructure Replication in Injection Moulding

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Arlø, Uffe Rolf

    2005-01-01

    topography is transcribed onto the plastic part through complex mechanisms. This replication however, is not perfect, and the replication quality depends on the plastic material properties, the topography itself, and the process conditions. This paper describes and discusses an investigation of injection...... moulding of surface microstructures. Emphasis is put on the ability to replicate surface microstructures under normal injection moulding conditions, notably with low cost materials at low mould temperatures. The replication of surface microstructures in injection moulding has been explored...... for Polypropylene at low mould temperatures. The process conditions were varied over the recommended process window for the material. The geometry of the obtained structures was analyzed. Evidence suggests that step height replication quality depends linearly on structure width in a certain range. Further...

  15. The development of thermoplastic fibre based reinforcements for the rotational moulding process

    Science.gov (United States)

    Alemán, D. N. Castellanos; McCourt, M.; Kearns, M. P.; Martin, P. J.; Butterfield, J.

    2018-05-01

    Rotational moulding is a method used to produce hollow plastic parts through the heating, melting and cooling of polymer powder within a metal mould. A wide range of products are made using this process, such as fluid containment tanks, boats, light weight vehicle bodies and marine buoys. Rotomoulded composites using thermoplastic fibres are of increasing interest to the industry, as they have the potential to significantly improve impact strength, whilst reducing part weight, resulting in a structure that is 100% recyclable compared to a traditional composite. A series of self-reinforced thermoplastic weaves can be used to produce a number of composite structures using the rotational moulding process. This work outlines the improvements obtained from the range of rotomoulded composites structures, as well as preforms that could be used in future rotational moulding work. Characteristics of self-reinforced materials were exploited with the aim of increasing the mechanical properties, preserving the weaves and increasing the nature of the material adhesion. Addition of the fabrics in the cooling stage was shown to be of great interest as this avoided exposure of the material to the peak temperature, which may affect the integrity of the fabric. Placing the weave during cooling was useful as the material could receive the maximum amount of tensile force during the impact test. A total of nine diverse types of compounds were manufactured and tested, with seven of the impact tests showing an increase in strength greater than 50%.

  16. Assessing the stretch-blow moulding FE simulation of PET over a large process window

    Science.gov (United States)

    Nixon, J.; Menary, G. H.; Yan, S.

    2017-10-01

    Injection stretch blow moulding has been extensively researched for numerous years and is a well-established method of forming thin-walled containers. This paper is concerned with validating the finite element analysis of the stretch-blow-moulding (SBM) process in an effort to progress the development of injection stretch blow moulding of poly(ethylene terephthalate). Extensive data was obtained experimentally over a wide process window accounting for material temperature, air flow rate and stretch-rod speed while capturing cavity pressure, stretch-rod reaction force, in-mould contact timing and material thickness distribution. This data was then used to assess the accuracy of the correlating FE simulation constructed using ABAQUS/Explicit solver and an appropriate user-defined viscoelastic material subroutine. Results reveal that the simulation was able to pick up the general trends of how the pressure, reaction force and in-mould contact timings vary with the variation in preform temperature and air flow rate. Trends in material thickness were also accurately predicted over the length of the bottle relative to the process conditions. The knowledge gained from these analyses provides insight into the mechanisms of bottle formation, subsequently improving the blow moulding simulation and potentially providing a reduction in production costs.

  17. Selected parameters of moulding sands for designing quality control systems

    Directory of Open Access Journals (Sweden)

    J. Jakubski

    2010-07-01

    Full Text Available One of the modern methods of production optimisation are artificial neural networks. Neural networks owe their popularity to the fact thatthey are convenient tools, which can be utilised in a wide scope of problems. They are capable of reflecting complex functions. Especiallytheir non-linearity should be emphasised. They are gaining wider and wider application in the foundry industry, among others, to controlmelting processes in cupolas and arc furnaces, designing castings and supply systems, control of moulding sands treatments, prediction ofproperties of cast alloys as well as selecting die casting.An attempt of the application neural networks to the quality control of moulding sands with bentonite is presented in the paper. This isa method of assessing the suitability of moulding sands by finding correlations in between individual parameters, by means of artificialneural network systems. The presented investigations were performed with the application of the Statistica 8.0 program.The investigations were aimed at the selection of the proper kind of a neural network for prediction a sand moistness on the bases ofcertain moulding sand properties such as: permeability, compactibility and friability. These parameters – determined as sand moistness functions - were introduced as initial parameters.Application of the Statistica program allowed for an automatic selection of the most suitable network for the reflection of dependencies and interactions existing among the proposed parameters. The best results were obtained for unidirectional multi-layer perception network (MLP. The neural network sensitivity to individual moulding sand parameters was determined, which allowed to reject not important parameters when constructing the network.

  18. Investigation of the pressure generated in the mould cavity during polyurethane integral skin foam moulding

    Directory of Open Access Journals (Sweden)

    2008-07-01

    Full Text Available An industrial scale measuring system was set up to investigate the pressure arising in the mould cavity during polyurethane integral skin foaming. The system is able to measure the pressure arising in the mould cavity and the pressure distribution using a piezoresistive pressure sensor. The pressure distribution was measured at 18 points along the mould surface at constant production parameters. Then six production parameters, which affect the pressure, were investigated in detail with the Taguchi method of experimental design. The results of the design were processed by ANOVA (analysis of variance. Three major influencing parameters were estimated by regression analysis. Finally an equation was developed to give a good estimation to the pressure arising in the mould cavity.

  19. Thermoluminescent characteristics of diopside-teflon composites for radiation dosimetry

    International Nuclear Information System (INIS)

    Melo, A.P.; Caldas, L.V.E.

    2006-01-01

    Diopside - Teflon composites were been studied in relation to their dosimetric properties for high-dose dosimetry. Diopside from Minas Gerais, Brazil, CaMg(Si 2 O 6 ), was obtained in form of rude mineral with inclusions of quartz. The samples were prepared and only Diopside grains obtained. Pellets of Diopside-Teflon composites were prepared in the proportion of 2(Teflon): 1 (Diopside).The TL response repeatability presented a maximum coefficient of variation of 7.5%. The calibration curve is linear between 0.5 Gy and 1 kGy. TL emission spectra present three emissions of similar intensities at 570 nm, 590 nm and between 610-635 nm. The results suggest that the material presents good characteristics for use as high-dose radiation detectors. (Author)

  20. Anti-stiction coating of PDMS moulds for rapid microchannel fabrication by double replica moulding

    DEFF Research Database (Denmark)

    Zhuang, Guisheng; Kutter, Jörg Peter

    2011-01-01

    ), which resulted in an anti-stiction layer for the improved release after PDMS casting. The deposition of FDTS on an O2 plasma-activated surface of PDMS produced a reproducible and well-performing anti-stiction monolayer of fluorocarbon, and we used the FDTS-coated moulds as micro-masters for rapid......In this paper, we report a simple and precise method to rapidly replicate master structures for fast microchannel fabrication by double replica moulding of polydimethylsiloxane (PDMS). A PDMS mould was surface-treated by vapour phase deposition of 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS...

  1. Investigations of the Influence of the Matrix Recycling on Properties of the Moulding Sand with Geopol 618 Binder

    Directory of Open Access Journals (Sweden)

    J. Kamińska

    2013-01-01

    Full Text Available Self-hardening moulding sands with water-glass hardened by liquid esters are applied in several foundry plants for making moulds for the production of heavy iron and steel castings. The main good point of this process is a low cost of sands. However, on account of a lowsusceptibility of this moulding sand for the matrix reclamation the fraction of sands originated from the reclamation is limited.The investigations presented in this work were aimed at the determination of the addition of the reclaimed material, obtained in the dry mechanical reclamation, on properties of the moulding sand with the Geopol 618 binder, which is water-glass modified by polymers and hardened by esters.

  2. Investigations of the Influence of the Matrix Recycling on Properties of the Moulding Sand with Geopol 618 Binder

    Directory of Open Access Journals (Sweden)

    Kamińska J.

    2013-03-01

    Full Text Available Self-hardening moulding sands with water-glass hardened by liquid esters are applied in several foundry plants for making moulds for the production of heavy iron and steel castings. The main good point of this process is a low cost of sands. However, on account of a low susceptibility of this moulding sand for the matrix reclamation the fraction of sands originated from the reclamation is limited. The investigations presented in this work were aimed at the determination of the addition of the reclaimed material, obtained in the dry mechanical reclamation, on properties of the moulding sand with the Geopol 618 binder, which is water-glass modified by polymers and hardened by esters.

  3. Effect of pressure in mould on the mould cavity filling in Lost Foam process

    Directory of Open Access Journals (Sweden)

    T. Pacyniak

    2010-10-01

    Full Text Available In this study, the analysis of the influence of the pressure in mould on manufacture process of castings by the Lost Foam method wasintroduced. In particular, numerical simulation results of effect of pressure in mould on pouring rate, gas gap pressure and gas gap sizewere analyzed. For simulating investigations of the Lost Foam process introduced mathematical model of the process was used. In thismodel in detail was described and derived equation relating to the changes of the gas pressure in the gas gap. The mathematical description uses the equation of gas state and the equation of Darcy’s rate of filtration. Presented studies indicated, that with decrease of pressure in mould the pouring rate increased and the gas pressure in gas gap and gas gap size decreased. For pressures in mould from the range of 20÷100 kPa, pouring rates achieved values from 30÷3 cm/s respectively.

  4. Examination of injection moulded thermoplastic maize starch

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available This paper focuses on the effect of the different injection moulding parameters and storing methods on injection moulded thermoplastic maize starch (TPS. The glycerol and water plasticized starch was processed in a twin screw extruder and then with an injection moulding machine to produce TPS dumbbell specimens. Different injection moulding set-ups and storing conditions were used to analyse the effects on the properties of thermoplastic starch. Investigated parameters were injection moulding pressure, holding pressure, and for the storage: storage at 50% relative humidity, and under ambient conditions. After processing the mechanical and shrinkage properties of the manufactured TPS were determined as a function of the ageing time. While conditioning, the characteristics of the TPS changed from a soft material to a rigid material. Although this main behaviour remained, the different injection moulding parameters changed the characteristics of TPS. Scanning electron microscope observations revealed the changes in the material on ageing.

  5. Scanning probe lithography for nanoimprinting mould fabrication

    International Nuclear Information System (INIS)

    Luo Gang; Xie Guoyong; Zhang Yongyi; Zhang Guoming; Zhang Yingying; Carlberg, Patrick; Zhu Tao; Liu Zhongfan

    2006-01-01

    We propose a rational fabrication method for nanoimprinting moulds by scanning probe lithography. By wet chemical etching, different kinds of moulds are realized on Si(110) and Si(100) surfaces according to the Si crystalline orientation. The structures have line widths of about 200 nm with a high aspect ratio. By reactive ion etching, moulds with patterns free from the limitation of Si crystalline orientation are also obtained. With closed-loop scan control of a scanning probe microscope, the length of patterned lines is more than 100 μm by integrating several steps of patterning. The fabrication process is optimized in order to produce a mould pattern with a line width about 10 nm. The structures on the mould are further duplicated into PMMA resists through the nanoimprinting process. The method of combining scanning probe lithography with wet chemical etching or reactive ion etching (RIE) provides a resistless route for the fabrication of nanoimprinting moulds

  6. Determination of thermal conductivity in foundry mould mixtures

    Directory of Open Access Journals (Sweden)

    G. Solenički

    2010-01-01

    Full Text Available For a thorough understanding of the behaviour of foundry mould mixtures, a good knowledge of thermal properties of mould materials is needed. Laboratory determination of thermal conductivity of mould mixtures enables a better control over scabbing defects which are a major problem in green sand mould mixtures. A special instrument has been designed for that purpose and it is described in this work.

  7. Influence of the reclamation method of spent moulding sands on the possibility of creating favourable conditions for gases flow in a mould

    Directory of Open Access Journals (Sweden)

    Łucarz M.

    2017-03-01

    Full Text Available The results of investigations concerning the influence of the applied sand matrix (fresh sand, reclaim on the properties of moulding sands used for production of large dimensional castings (ingot moulds, ladles, are presented in the hereby paper. The performed investigations were aimed at determining the influence of various reclamation methods of spent moulding sands on the quality of the obtained reclaimed material. Moulding sands were prepared on the fresh quartz matrix as well as on sand matrices obtained after various reclamation methods. The selected moulding sand parameters were tested (strength, permeability, grindability, ignition losses, pH reactions. It can be stated, on the basis of the performed investigations, that the kind of the applied moulding sand matrix is of an essential meaning from the point of view of creating conditions minimising formation of large amounts of gases and their directional migration in a casting mould.

  8. A stone mould from Klinovac

    Directory of Open Access Journals (Sweden)

    Bulatović Aleksandar

    2002-01-01

    Full Text Available A two-piece stone mould that reached the National Museum at Vranje in 1966 had been recovered from a depth of about one meter at the site known as Tri Kruške (Three Pear-trees, the village of Klinovac. The site is situated on a river terrace on the right bank of the Krševica River some 15 kilometers south of Vranje. The mould was carved out of metamorphic rock from the class of schist, more exactly, of greenschist (with chlorite and mica as its constituent minerals that is widespread in the area, which geologically belongs to the upper (Vlasina complex of the Serbian-Macedonian mass. The mould was intended for casting four kinds of bronze weapons: three chisels and a winged axe. More sensitive as dating evidence, the winged axe (Ärmchenbeil may be broadly dated to the last three centuries of the second millennium BC. The type is geographically related with the Aegean, while its northernmost findspot so far is Pobit Kamak in northern Bulgaria. The chisels cast in this mould do not have direct analogies, although many hoards of similar tools have been registered in Croatia, Romania and Central Europe. Apparently the mould was made by a local workshop and from the locally available raw material. The possible activity of local workshops in the above mentioned period has already been presumed by scholars, and the Klinovac mould constitutes yet another corroboration of the hypothesis. Nevertheless its Aegean origin should not be ruled out completely, because cultural contacts between the Late Bronze Age population inhabiting the region and their southern neighbours seem quite certain, as evidenced by Mycenaean pottery discovered on the site of Resulja at Lučani near Bujanovac.

  9. Demoulding force in micro-injection moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.

    2012-01-01

    The paper reports an experimental study that investigates part demoulding behavior in micro injection moulding (MIM) with a focus on the effects of pressure (P) and temperature (T) on the demoulding forces. Demoulding of a microfluidics part is conducted and the four processing parameters of melt...... temperature (Tb), mould temperature (Tm), holding pressure (Ph) and injection speed (Vi) are analysed. The result using different combinations of process parameters were used to identify the best processing conditions in regards to demoulding forces when moulding micro parts....

  10. Self construction in schizophrenia: a discourse analysis.

    Science.gov (United States)

    Meehan, Trudy; MacLachlan, Malcolm

    2008-06-01

    Lysaker and Lysaker (Theory and Psychology, 12(2), 207-220, 2002) employ a dialogical theory of self in their writings on self disruption in schizophrenia. It is argued here that this theory could be enriched by incorporating a discursive and social constructionist model of self. Harr's model enables researchers to use subject positions to identify self construction in people with a diagnosis of schizophrenia that the dialogical model, using analysis of narrative, does not as easily recognize. The paper presents a discourse analysis of self construction in eight participants with a diagnosis of schizophrenia. Transcripts from semi-structured interviews are analysed, wherein focus falls on how participants construct self in talk through the use of subject positioning. The findings indicate that Harr's theory of self and the implied method of discourse analysis enables more subtle and nuanced constructions of self to be identified than those highlighted by Lysaker and Lysaker (Theory and Psychology, 12(2), 207-220, 2002). The analysis of subject positions revealed that participants constructed self in the form of Harr's (The singular self: An introduction to the psychology of personhood, 1998, London: Sage) self1, self2, and self3. The findings suggest that there may be constructions of self used by people diagnosed with schizophrenia that are not recognized by the current research methods focusing on narrative. The paper argues for the recognition of these constructions and by implication a model of self that takes into account different levels of visibility of self construction in talk.

  11. Mycotoxigenic and proteolytic potential of moulds associated with ...

    African Journals Online (AJOL)

    Among the 33 moulds isolated from 20 samples of wood-smoked Chlamydoselachus anguincus (shark-fish) 20 isolates were capable of producing metabolites toxic to fertile Hubbard Golden Comet (Niger chick) eggs. Aspergillus and Pencillium isolates were the predominant moulds. Other toxigenic moulds isolated were ...

  12. Sampling And Identifying Of Mould In The Library Building

    Directory of Open Access Journals (Sweden)

    Abdul Wahab Suriani Ngah

    2016-01-01

    Full Text Available Despite the growing concern over mould and fungi infestations on library building, little has been reported in the literature on the development of an objective tool and criteria for measuring and characterising the mould and fungi. In this paper, an objective based approach to mould and fungi growth assessment using various sampling techniques and its identification using microscopic observation are proposed. This study involved three library buildings of Higher Institution Educational in Malaysia for data collection purpose and study of mould growth. The mould sampling of three libraries was collected using Coriolis air sampler, settling plate air sampling using Malt Extract Agar (MEA, IAQ MOLD Alexeter IAQ-Pro Asp/Pen® Test and swab sampling techniques. The IAQ MOLD Alexeter IAQ-Pro Asp/Pen® Test and traditional method technique identified various mould species immediately on the site, and the microscopic observation identifies common types of the mould such as Aspergillus, Penicillium and Stachybotrys’s. The sample size and particular characteristics of each library will result in the mould growth pattern and finding.

  13. Report on converging insert moulding with µ-IM

    DEFF Research Database (Denmark)

    Islam, Aminul

    moulding with µ-IM  Task 5.2.1 and COTECH demonstrator: guide line for 5PRC production based on the concept of Task 5.2.1 Information and results provided by this deliverable will be directly used for one of the COTECH demonstrators production which will call for convergent insert moulding with µ......Task 5.2.1 deals with the technical feasibility of converging the state-of-the-art µ IM process with insert moulding to offer a wide range of multi-material µ components. The main objective of this deliverable is to summarize state-of-the-art information and to make the guideline needed...... for the convergence. In particular the following aspects are summed up in the deliverable:  Need for converging insert moulding with µ-IM  Objectives and expected outcome from task 5.2.1  State-of-the-art micro insert moulding and different scenario of micro insert moulding  Challenges ahead of converging insert...

  14. Thermoluminescent dosemeters of CaSO4: Dy + Teflon

    International Nuclear Information System (INIS)

    Campos, L.L.

    1989-01-01

    The development of a pellet dosemeter of CaSO 4 : Dy + Teflon at the Dosimetric Materials Production Laboratory - IPEN/Brazilian CNEN-SP is presented. The pellets were produced by cold pressing and sintering a mixture of CaSO 4 : Dy and Teflon powders. The pellet characteristics from the point of view of dosimetry. A filter combination providing an energy independent response from 20 KeV to 1,25 MeV was obtained. The dosemeter consists of three pellets sealed between two thin plastic sheets and placed under plastic and lead filters. The combination of these three filters allows to determine the energy of an unknown source. (author) [pt

  15. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger

    2014-01-01

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used in an inject......We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used...

  16. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used in an inject......We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used...

  17. CONTRIBUTIONS TO DIVERSIFY SOLES MOULDS THAT FORMS DIRECTLY ON FACES SHOES

    Directory of Open Access Journals (Sweden)

    IONESCU Cozmin

    2015-05-01

    Full Text Available The classical moulds which are currently used for forming the soles directly on the uppers, allow obtaining one sole model. One mould for each foot is made, and at least one mould for each size number in the size number series. To manufacture one single sole model in the sizes series an average set of 16 moulds are needed. Changing the model implies the entire production of a new set of moulds. Therefore, a large diversification of the soles requires the manufacturing a quantity of moulds sets equal with the quantity of sole models. In this paper are presented solutions to obtain more cavity shapes in the same mould, through the use of modular interchangeable pieces. The moulds with versatile cavities have the same functional characteristics as the moulds with unique cavities, are usable on the same type of machines and can be used independently or together with the classical moulds. A brief analysis on the technological processes for manufacturing moulds with versatile cavities reveals a significant lowering of the manufacturing time for moulds in which will be obtained other sole models. This is due to the fact that some of the mould parts are reused. In conclusion, the producers that chose this type of moulds can launch on the market new models in a shorter time and at lower prices.

  18. Mathematical model of the metal mould surface temperature optimization

    International Nuclear Information System (INIS)

    Mlynek, Jaroslav; Knobloch, Roman; Srb, Radek

    2015-01-01

    The article is focused on the problem of generating a uniform temperature field on the inner surface of shell metal moulds. Such moulds are used e.g. in the automotive industry for artificial leather production. To produce artificial leather with uniform surface structure and colour shade the temperature on the inner surface of the mould has to be as homogeneous as possible. The heating of the mould is realized by infrared heaters located above the outer mould surface. The conceived mathematical model allows us to optimize the locations of infrared heaters over the mould, so that approximately uniform heat radiation intensity is generated. A version of differential evolution algorithm programmed in Matlab development environment was created by the authors for the optimization process. For temperate calculations software system ANSYS was used. A practical example of optimization of heaters locations and calculation of the temperature of the mould is included at the end of the article

  19. Mathematical model of the metal mould surface temperature optimization

    Energy Technology Data Exchange (ETDEWEB)

    Mlynek, Jaroslav, E-mail: jaroslav.mlynek@tul.cz; Knobloch, Roman, E-mail: roman.knobloch@tul.cz [Department of Mathematics, FP Technical University of Liberec, Studentska 2, 461 17 Liberec, The Czech Republic (Czech Republic); Srb, Radek, E-mail: radek.srb@tul.cz [Institute of Mechatronics and Computer Engineering Technical University of Liberec, Studentska 2, 461 17 Liberec, The Czech Republic (Czech Republic)

    2015-11-30

    The article is focused on the problem of generating a uniform temperature field on the inner surface of shell metal moulds. Such moulds are used e.g. in the automotive industry for artificial leather production. To produce artificial leather with uniform surface structure and colour shade the temperature on the inner surface of the mould has to be as homogeneous as possible. The heating of the mould is realized by infrared heaters located above the outer mould surface. The conceived mathematical model allows us to optimize the locations of infrared heaters over the mould, so that approximately uniform heat radiation intensity is generated. A version of differential evolution algorithm programmed in Matlab development environment was created by the authors for the optimization process. For temperate calculations software system ANSYS was used. A practical example of optimization of heaters locations and calculation of the temperature of the mould is included at the end of the article.

  20. Simple and robust near-infrared spectroscopic monitoring of indium-tin-oxide (ITO) etching solution using Teflon tubing

    International Nuclear Information System (INIS)

    Nah, Sanghee; Ryu, Kyungtag; Cho, Soohwa; Chung, Hoeil; Namkung, Hankyu

    2006-01-01

    The ability to monitor etching solutions using a spectroscopy directly through existing Teflon lines in electronic industries is highly beneficial and offers many advantages. A monitoring method was developed using near-infrared (NIR) measurements with Teflon tubing as a sample container for the quantification of components in the indium-tin-oxide (ITO) etching solution composed of hydrochloric acid (HCl), acetic acid (CH 3 COOH) and water. Measurements were reproducible and it was possible to use the same calibration model for different Teflon tubings. Even though partial least squares (PLS) calibration performance was slightly degraded for Teflon cells when compared to quartz cells of the similar pathlength, the calibration data correlated well with reference data. The robustness of Teflon-based NIR measurement was evaluated by predicting the spectra of 10 independent samples that were collected using five different Teflon tubes. Although, two Teflon tubes were visually less transparent than the other three, there was no significant variation in the standard error of predictions (SEPs) among the five Teflon tubes. Calibration accuracy was successfully maintained and highly repeatable prediction results were achieved. This study verifies that a Teflon-based NIR measurement is reliable for the monitoring of etching solutions and it can be successfully integrated into on-line process monitoring

  1. Thermally induced atomic diffusion at the interface between release agent coating and mould substrate in a glass moulding press

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Jun; Fukase, Yasushi [Toshiba Machine Co., Ltd, Ooka 2068-3, Numazu-Shi, Shizuoka-Ken, 410-8510 (Japan); Yan Jiwang; Zhou Tianfeng; Kuriyagawa, Tsunemoto, E-mail: yanjw@pm.mech.tohoku.ac.jp [Department of Mechanical Systems and Design, Graduate School of Engineering, Tohoku University, Aoba 6-6-01, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

    2011-06-01

    In a glass moulding press (GMP) for refractive/diffractive hybrid lenses, to improve the service life of nickel-phosphorus (Ni-P) plated moulds, it is necessary to control the diffusion of constituent elements from the mould into the release agent coating. In this study, diffusion phenomena of constituents of Ni-P plating are investigated for two types of release agent coatings, iridium-platinum (Ir-Pt) and iridium-rhenium (Ir-Re), by cross-sectional observation, compositional analysis and stress measurements. The results show that Ni atoms in the plating layer flow from regions of compressive stress to regions of tensile stress. In the case of the Ir-Pt coated mould, the diffusion of Ni is promoted from the grain boundaries between the Ni and Ni{sub 3}P phases in the plating towards the surface of the Ir-Pt coating. However, in the Ir-Re coated mould, the diffusion of Ni is suppressed because the diffusion coefficient of Ni in the Ir-Re alloy is smaller than that in the Ir-Pt alloy, although the stress state is similar in both cases. By controlling the diffusion of Ni atoms, the use of Ir-Re alloy as a release agent coating for Ni-P plated moulds is expected to lead to a high degree of durability.

  2. Investigation of field temperature in moulds of foamed plaster

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2007-12-01

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

  3. Dilatometric examination of moulds with plaster binder

    Directory of Open Access Journals (Sweden)

    M. Nadolski

    2011-01-01

    Full Text Available Investigations concerning thermal expansion of moulding materials with plaster binder have been performed for two mixture compositionsof Authors’ own design, as well as for the material used in jewellery industry under the Prima-Cast trade name, and for ThermoMold 1200moulding material. The results of dilatometric examinations of these materials, carried out within the temperature range from about 20°Cto 650°C by means of the DA-3 automatic dilatometer, have been compared. An analysis of this comparison has revealed that it is thematrix composition which is decisive for the magnitude of dimensional changes of moulds, and that applying components which do notexhibit polymorphic transformations reduces dimensional changes of a mould during its thermal treatment.

  4. Biodegradable materials as binders for IVth generation moulding sands

    OpenAIRE

    K. Major-Gabry

    2015-01-01

    This paper focuses on the possibility of using the biodegradable materials as binders (or parts of binders?compositions) for foundry moulding and core sands. Results showed that there is a great possibility of using available biodegradable materials as foundry moulding sand binders. Using biodegradable materials as partial content of new binders, or additives to moulding sands may not only decrease the toxicity and increase reclamation ability of tested moulding sands, but also accelerate the...

  5. Micromilling of hardened tool steel for mould making applications

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2005-01-01

    geometries as those characterizing injection moulding moulds. The realization of the micromilling process in connection with hardened tool steel as workpiece material is particularly challenging. The low strength of the miniaturized end mills implies reduction and accurate control of the chip load which...... wear. This paper presents the micromilling process applied to the manufacturing of micro injection moulding moulds in hardened tool steel, presenting experimental evidence and possible solutions to the above-mentioned issues....

  6. Micro-powder injection moulding of tungsten

    International Nuclear Information System (INIS)

    Zeep, B.

    2007-12-01

    For He-cooled Divertors as integral components of future fusion power plants, about 300000 complex shaped tungsten components are to be fabricated. Tungsten is the favoured material because of its excellent properties (high melting point, high hardness, high sputtering resistance, high thermal conductivity). However, the material's properties cause major problems for large scale production of complex shaped components. Due to the resistance of tungsten to mechanical machining, new fabrication technologies have to be developed. Powder injection moulding as a well established shaping technology for a large scale production of complex or even micro structured parts might be a suitable method to produce tungsten components for fusion applications but is not yet commercially available. The present thesis is dealing with the development of a powder injection moulding process for micro structured tungsten components. To develop a suitable feedstock, the powder particle properties, the binder formulation and the solid load were optimised. To meet the requirements for a replication of micro patterned cavities, a special target was to define the smallest powder particle size applicable for micro-powder injection moulding. To investigate the injection moulding performance of the developed feedstocks, experiments were successfully carried out applying diverse cavities with structural details in micro dimension. For debinding of the green bodies, a combination of solvent debinding and thermal debinding has been adopted for injection moulded tungsten components. To develop a suitable debinding strategy, a variation of the solvent debinding time, the heating rate and the binder formulation was performed. For investigating the thermal consolidation behaviour of tungsten components, sinter experiments were carried out applying tungsten powders suitable for micro-powder injection moulding. First mechanical tests of the sintered samples showed promising material properties such as a

  7. Surface Micro Topography Replication in Injection Moulding

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf; Hansen, Hans Nørgaard; Kjær, Erik Michael

    2005-01-01

    The surface micro topography of injection moulded plastic parts can be important for aesthetical and technical reasons. The quality of replication of mould surface topography onto the plastic surface depends among other factors on the process conditions. A study of this relationship has been...... carried out with rough EDM (electrical discharge machining) mould surfaces, a PS grade, and by applying established three-dimensional topography parameters. Significant quantitative relationships between process parameters and topography parameters were established. It further appeared that replication...

  8. Developments in the implantation of moulding tools

    International Nuclear Information System (INIS)

    Dearnaley, G.; Delves, B.G.

    1983-01-01

    The process of surface hardening by the ion implantation of nitrogen has proved to be remarkably effective for the treatment of moulds, and indeed the whole range of screws, nozzles, sprue bushes, etc., as well as dies for injection moulding or extrusion of filled plastics. Implantation equipment, based upon our designs, is now available commercially. Corrosion and pitting of moulds can be reduced by a new ionic treatment known as ion beam mixing. A thin coating of protective material, such as chromium on silicon, is bombarded with ions so as to mix or key it to the mould surface. Alternatively, hydrocarbon vapour can be cracked on to the metal surface to form a tenacious and protective carbon film. Industrial applications for this novel process are now being sought. (author)

  9. Bond strength investigation of two shot moulded polymer

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul

    This report on the project “Bond strength investigation of two shot moulded polymers” has been submitted for fulfilling the requirements for the course “Experimental Plastic Technology – 42234” at IPL-DTU. Two shot moulding is a classic manufacturing process to combine two different polymers...... in a single product and it is getting more and more importance day by day. One of the biggest challenges of two shot moulding is to achieve a reasonably good bonding between two polymers. The purpose of this project is to investigate the effects of different process, material and machine parameters...... on the bond strength of two shot moulded polymers. For the experiments two engineering polymers (PS and ABS) were used. After all the experimental work, several parameters were found which could effectively control the bond strength of two shot moulded polymers. This report also presents different aspects...

  10. Moulds in food spoilage

    DEFF Research Database (Denmark)

    Filtenborg, Ole; Frisvad, Jens Christian; Thrane, Ulf

    1996-01-01

    There is an increasing knowledge and understanding of the role played by moulds in food spoilage. Especially the discovery of mycotoxin production in foods has highligh-ted the importance of moulds in food quality. It is, however, only within the last 5-10 years that major progresses have been made...... the associated or critical funga and has been shown to consist of less than 10 species. In this paper the associated funga is described for the following foods: Citrus and pomaceous fruits, potato and yam tubers, onions, rye, wheat, rye bread, cheese and fermented sausages and whenever possible the selective...

  11. CaSO4: Dy + Teflon thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Campos, L.L.

    1986-01-01

    A pellet dosemeter of CaSO 4 : Dy + Teflon was developed at IPEN. CaSO 4 : Dy thermoluminescent phosphor, grown in the Dosimetric Materials Production Laboratory was chosen, due to its high sensitivity, ease of preparation and comparatively low cost. Pellets were produced by cold pressing and sintering a mixture of CaSO 4 : Dy and Teflon powders. Extensive work was done to study in detail all CaSO 4 : Dy pellets characteristics from the point of view of dosimetry with the purpose of introducing it in the routine use. A filter combination providing an energy independent response from 20 KeV to 1,25 MeV was obtained. The dosemeter consists of three pellets sealed between two thin plastic sheets and placed under plastic and lead filters. The combination of these tree filters allows the exposure as well as the energy determination of an unknown source. (Author) [pt

  12. An Efficient Construction of Self-Dual Codes

    OpenAIRE

    Lee, Yoonjin; Kim, Jon-Lark

    2012-01-01

    We complete the building-up construction for self-dual codes by resolving the open cases over $GF(q)$ with $q \\equiv 3 \\pmod 4$, and over $\\Z_{p^m}$ and Galois rings $\\GR(p^m,r)$ with an odd prime $p$ satisfying $p \\equiv 3 \\pmod 4$ with $r$ odd. We also extend the building-up construction for self-dual codes to finite chain rings. Our building-up construction produces many new interesting self-dual codes. In particular, we construct 945 new extremal self-dual ternary $[32,16,9]$ codes, each ...

  13. Best practice strategies for validation of micro moulding process simulation

    DEFF Research Database (Denmark)

    Costa, Franco; Tosello, Guido; Whiteside, Ben

    2009-01-01

    are the optimization of the moulding process and of the tool using simulation techniques. Therefore, in polymer micro manufacturing technology, software simulation tools adapted from conventional injection moulding can provide useful assistance for the optimization of moulding tools, mould inserts, micro component...... are discussed. Recommendations regarding sampling rate, meshing quality, filling analysis methods (micro short shots, flow visualization) and machine geometry modelling are given on the basis of the comparison between simulated and experimental results within the two considered study cases.......Simulation programs in polymer micro replication technology are used for the same reasons as in conventional injection moulding. To avoid the risks of costly re-engineering, the moulding process is simulated before starting the actual manufacturing process. Important economic factors...

  14. Ultras-stable Physical Vapor Deposited Amorphous Teflon Films with Extreme Fictive Temperature Reduction

    Science.gov (United States)

    McKenna, Gregory; Yoon, Heedong; Koh, Yung; Simon, Sindee

    In the present work, we have produced highly stable amorphous fluoropolymer (Teflon AF® 1600) films to study the calorimetric and relaxation behavior in the deep in the glassy regime. Physical vapor deposition (PVD) was used to produce 110 to 700 nm PVD films with substrate temperature ranging from 0.70 Tg to 0.90 Tg. Fictive temperature (Tf) was measured using Flash DSC with 600 K/s heating and cooling rates. Consistent with prior observations for small molecular weight glasses, large enthalpy overshoots were observed in the stable amorphous Teflon films. The Tf reduction for the stable Teflon films deposited in the vicinity of 0.85 Tg was approximately 70 K compared to the Tgof the rejuvenated system. The relaxation behavior of stable Teflon films was measured using the TTU bubble inflation technique and following Struik's protocol in the temperature range from Tf to Tg. The results show that the relaxation time decreases with increasing aging time implying that devitrification is occurring in this regime.

  15. Improving the accuracy of micro injection moulding process simulations

    DEFF Research Database (Denmark)

    Marhöfer, David Maximilian; Tosello, Guido; Islam, Aminul

    and are therefore limited in the capability of modelling the polymer flow in micro cavities. Hence, new strategies for comprehensive simulation models which provide more precise results open up new opportunities and will be discussed. Modelling and meshing recommendations are presented, leading to a multi......Process simulations in micro injection moulding aim at the optimization and support of the design of the mould, mould inserts, the plastic product, and the process. Nevertheless, dedicated software packages for micro injection moulding are not available. They are developed for macro plastic parts...

  16. A proper strategy for combating mould.

    Science.gov (United States)

    Cheong, Cedric

    2014-02-01

    managing director of Mycologia & Mould Worx, MSc, B.(Env. Sci.), TAE40110, examines the topic of mould exposure in healthcare facilities, and the associated duty of care for hospital facility managers and engineers. The article, published here in slightly adapted form, also focuses on the need for additional training of key personnel on the risks associated with exposure to environmental microbial contamination.

  17. Moulding of Sub-micrometer Surface Structures

    DEFF Research Database (Denmark)

    Pranov, Henrik; Rasmussen, Henrik K.; Larsen, Niels Bent

    2006-01-01

    The experiments strongly suggest that the possibility to injection mould sub-micrometer surface structures in polymers mainly relates to the forces originating from the adhesive energy between polymer and shim.......The experiments strongly suggest that the possibility to injection mould sub-micrometer surface structures in polymers mainly relates to the forces originating from the adhesive energy between polymer and shim....

  18. Injection moulding for macro and micro products

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul

    used for macro products but with the ages it is going deep into the micro areas having machine and process improvements. Extensive research work on injection moulding is going on all over the world. New ideas are flowing into the machines, materials and processes. The technology has made significant......The purpose of the literature survey is to investigate the injection moulding technology in the macro and micro areas from the basic to the state-of-the-art recent technology. Injection moulding is a versatile production process for the manufacturing of plastic parts and the process is extensively...

  19. Development and characterisation of injection moulded, all-polypropylene composites

    Directory of Open Access Journals (Sweden)

    A. Kmetty

    2013-02-01

    Full Text Available In this work, all-polypropylene composites (all-PP composites were manufactured by injection moulding. Prior to injection moulding, pre-impregnated pellets were prepared by a three-step process (filament winding, compression moulding and pelletizing. A highly oriented polypropylene multifilament was used as the reinforcement material, and a random polypropylene copolymer (with ethylene was used as the matrix material. Plaque specimens were injection moulded from the pellets with either a film gate or a fan gate. The compression moulded sheets and injection moulding plaques were characterised by shrinkage tests, static tensile tests, dynamic mechanical analysis and falling weight impact tests; the fibre distribution and fibre/matrix adhesion were analysed with light microscopy and scanning electron microscopy. The results showed that with increasing fibre content, both the yield stress and the perforation energy significantly increased. Of the two types of gates used, the fan gate caused the mechanical properties of the plaque specimens to become more homogeneous (i.e., the differences in behaviour parallel and perpendicular to the flow direction became negligible.

  20. Microfluidic Pumps Containing Teflon [Trademark] AF Diaphragms

    Science.gov (United States)

    Willis, Peter; White, Victor; Grunthaner, Frank; Ikeda, Mike; Mathies, Richard A.

    2009-01-01

    Microfluidic pumps and valves based on pneumatically actuated diaphragms made of Teflon AF polymers are being developed for incorporation into laboratory-on-a-chip devices that must perform well over temperature ranges wider than those of prior diaphragm-based microfluidic pumps and valves. Other potential applications include implanted biomedical microfluidic devices, wherein the biocompatability of Teflon AF polymers would be highly advantageous. These pumps and valves have been demonstrated to function stably after cycling through temperatures from -125 to 120 C. These pumps and valves are intended to be successors to similar prior pumps and valves containing diaphragms made of polydimethylsiloxane (PDMS) [commonly known as silicone rubber]. The PDMS-containing valves ae designed to function stably only within the temperature range from 5 to 80 C. Undesirably, PDMS membranes are somwehat porous and retain water. PDMS is especially unsuitable for use at temperatures below 0 C because the formation of ice crystals increases porosity and introduces microshear.

  1. Modeling and Optimization of Phenol Formaldehyde Resin Sand Mould System

    Directory of Open Access Journals (Sweden)

    Chate G. R.

    2017-06-01

    Full Text Available Chemical bonded resin sand mould system has high dimensional accuracy, surface finish and sand mould properties compared to green sand mould system. The mould cavity prepared under chemical bonded sand mould system must produce sufficient permeability and hardness to withstand sand drop while pouring molten metal through ladle. The demand for improved values of permeability and mould hardness depends on systematic study and analysis of influencing variables namely grain fineness number, setting time, percent of resin and hardener. Try-error experiment methods and analysis were considered impractical in actual foundry practice due to the associated cost. Experimental matrices of central composite design allow conducting minimum experiments that provide complete insight of the process. Statistical significance of influencing variables and their interaction were determined to control the process. Analysis of variance (ANOVA test was conducted to validate the model statistically. Mathematical equation was derived separately for mould hardness and permeability, which are expressed as a non-linear function of input variables based on the collected experimental input-output data. The developed model prediction accuracy for practical usefulness was tested with 10 random experimental conditions. The decision variables for higher mould hardness and permeability were determined using desirability function approach. The prediction results were found to be consistent with experimental values.

  2. Application of microwaves for incinerating waste shell moulds and cores

    Directory of Open Access Journals (Sweden)

    K. Granat

    2008-08-01

    Full Text Available In the paper, investigation results of microwave heating application for incinerating waste shell moulds and cores made of moulding sands with thermosetting resins are presented. It was found that waste shell cores or shell moulds left after casting, separated from moulding sand, can be effectively incinerated. It was evidenced that microwave heating allows effective control of this process and its results. Incineration of waste moulds and cores made of commercial grades of resin-coated moulding sand using microwave heating was found to be an effective way of their utilisation. It was determined that the optimum burning time of these wastes (except those insufficiently disintegrated and not mixed with an activating agent is maximum 240 s at the used magnetron power of 650 W. It was noticed that proper disintegration of the wastes and use of suitable additives to intensify the microwave heating process guarantee significant reduction of the process time and its full stabilisation. Application of microwave heating for incinerating waste shell moulds and cores ensure substantial and measurable economic profits due to shorter process time and lower energy consumption.

  3. Self-Organized Construction with Continuous Building Material

    DEFF Research Database (Denmark)

    Heinrich, Mary Katherine; Wahby, Mostafa; Divband Soorati, Mohammad

    2016-01-01

    Self-organized construction with continuous, structured building material, as opposed to modular units, offers new challenges to the robot-based construction process and lends the opportunity for increased flexibility in constructed artifact properties, such as shape and deformation. As an example...... investigation, we look at continuous filaments organized into braided structures, within the context of bio-hybrids constructing architectural artifacts. We report the result of an early swarm robot experiment. The robots successfully constructed a braid in a self-organized process. The construction process can...... be extended by using different materials and by embedding sensors during the self-organized construction directly into the braided structure. In future work, we plan to apply dedicated braiding robot hardware and to construct sophisticated 3-d structures with local variability in patterns of filament...

  4. Precision moulding of polymer micro components

    DEFF Research Database (Denmark)

    Tosello, Guido

    2008-01-01

    The present research work contains a study concerning polymer micro components manufacturing by means of the micro injection moulding (µIM) process. The overall process chain was considered and investigated during the project, including part design and simulation, tooling, process analysis, part...... optimization, quality control, multi-material solutions. A series of experimental investigations were carried out on the influence of the main µIM process factors on the polymer melt flow within micro cavities. These investigations were conducted on a conventional injection moulding machine adapted...... to the production of micro polymer components, as well as on a micro injection moulding machine. A new approach based on coordinate optical measurement of flow markers was developed during the project for the characterization of the melt flow. In-line pressure measurements were also performed to characterize...

  5. Plasma sprayed coatings on mild steel split moulds for uranium casting

    International Nuclear Information System (INIS)

    Sreekumar, K.P.; Padmanaban, P.V.A.; Venkatramani, N.; Singh, S.P.; Saha, D.P.; Date, V.G.

    2002-01-01

    High velocity high temperature plasma jets are used to deposit metals and ceramics on metallic substrates for oxidation and corrosion protection applications. Plasma sprayed ceramic coatings on metallic substrates are also used to prevent its reaction with molten metals. Metal-alumina duplex coatings on mild steel split moulds have been developed and successfully used for casting of uranium. Techno-economics of the coated moulds against the conventional graphite moulds are a major advantage. Mild steel moulds of 600 mm long and 75 mm in diameter have been plasma spray coated with alumina over a bond coat of molybdenum. In-plant tests showed an increase in number of castings per mould compared to the commonly used graphite moulds. (author)

  6. ELECTROCHEMICAL TECHNOLOGIES FOR OBTAINING MOULDS FOR SOLES OF SHOES

    Directory of Open Access Journals (Sweden)

    Cornelia LUCA

    2013-05-01

    Full Text Available The paper presents contributions in the designing of some electrochemical technologiesfor the manufacturing of the moulds used in the footwear soles obtaining. There are presented a fewmethods for the moulds obtaining, using electro-deposit processes. There are presented thetechnological phases of the obtaining process of the electrolytes and electrodes preparing and thetechnological stages of the moulds manufacturing.

  7. Trap-controlled charge transport in corona-charged Teflon

    International Nuclear Information System (INIS)

    Gross, B.; Giacometti, J.A.; Ferreira, G.F.L.; Moreno A, R.A.

    1980-01-01

    The stability of negatively charged Teflon electrets is discussed. It is stated that it can only be explained by the assumption that the transport of excess charge is trap - controlled rather than mobility - controlled. (I.C.R.) [pt

  8. Gas-assisted injection moulding: adding two components and moveable inserts

    NARCIS (Netherlands)

    Neerincx, P.E.; Meijer, H.E.H.

    2009-01-01

    Gas assisted injection moulding (GAIM) is a technique that is successfully used for compensating shrinkage during injection moulding of thick walled but still accurate products with low levels of internal stresses and frozen-in orientation. In this study the authors apply GAIM in moulding 28 mm

  9. Plastia da valva mitral com a técnica do "Duplo Teflon": resultados de 10 anos Mitral valve repair with "Double Teflon" technique: 10-year results

    Directory of Open Access Journals (Sweden)

    Carlos Manuel de Almeida Brandão

    2007-12-01

    Full Text Available OBJETIVO: O objetivo deste trabalho é apresentar os resultados clínicos tardios da plástica da valva mitral com a técnica do "Duplo Teflon". MÉTODOS: A plástica de "Duplo Teflon" consiste em técnica de reparo mitral com ressecção quadrangular da cúspide posterior, anuloplastia segmentar com plicatura do anel com de fios com "pledgets" sobre uma tira de Teflon, e sutura borda a borda da cúspide. Entre abril de 1994 e dezembro de 2003, 133 pacientes com diagnóstico de insuficiência mitral degenerativa com alongamento ou rotura de cordas da cúspide posterior foram submetidos à plástica com esta técnica. A idade média foi de 60,4 anos e 60,9% eram do sexo feminino. Quanto à avaliação clínica no pré-operatório, 29,3% dos pacientes estavam em classe funcional IV, 55,7% em classe III e 15,0% em classe II. Técnicas associadas de plástica mitral foram utilizadas em 15,2% dos pacientes, sendo a mais comum o encurtamento de cordas. Vinte e seis (19,5% pacientes foram submetidos a operações associadas. RESULTADOS: Houve um (0,75% óbito hospitalar. No período pós-operatório tardio, 95,5% dos sobreviventes estavam em classe funcional I. As taxas linearizadas de tromboembolismo, reoperação e óbito foram 0,9%, 0,3% e 0,6% pacientes/ano, respectivamente. A sobrevida atuarial em 10 anos foi de 94,1% ± 3,6%. As sobrevidas atuariais livre de tromboembolismo e reoperação foram de 97,3 ± 1,5% e 99,2 ± 0,8%, respectivamente. Não houve casos de endocardite ou hemólise. CONCLUSÃO: A plástica da valva mitral com a técnica do "Duplo Teflon" apresenta baixa morbi-mortalidade e boa evolução clínica tardia.OBJECTIVE: The purpose of this paper is to present the late clinical results of mitral valve repair with the "Double Teflon" technique. METHODS: "Double Teflon" technique consists of a quadrangular resection of the posterior leaflet, annulus plication with "pledgetted" stitches over a Teflon patch, and leaflet suture. Between

  10. Myceliophthora thermophila syn. Sporotrichum thermophile: a thermophilic mould of biotechnological potential.

    Science.gov (United States)

    Singh, Bijender

    2016-01-01

    Myceliophthora thermophila syn. Sporotrichum thermophile is a ubiquitous thermophilic mould with a strong ability to degrade organic matter during optimal growth at 45 °C. Both genome analysis and experimental data have suggested that the mould is capable of hydrolyzing all major polysaccharides found in biomass. The mould is able to secrete a large number of hydrolytic enzymes (cellulases, laccases, xylanases, pectinases, lipases, phytases and some other miscellaneous enzymes) employed in various biotechnological applications. Characterization of the biomass-hydrolyzing activity of wild and recombinant enzymes suggests that this mould is highly efficient in biomass decomposition at both moderate and high temperatures. The native enzymes produced by the mould are more efficient in activity than their mesophilic counterparts beside their low enzyme titers. The mould is able to synthesize various biomolecules, which are used in multifarious applications. Genome sequence data of M. thermophila also supported the physiological data. This review describes the biotechnological potential of thermophilic mould, M. thermophila supported by genomic and experimental evidences.

  11. Experimental investigation on shrinkage and surface replication of injection moulded ceramic parts

    DEFF Research Database (Denmark)

    Islam, Aminul; Giannekas, Nikolaos; Marhöfer, David Maximilian

    2014-01-01

    Ceramic moulded parts are increasingly being used in advanced components and devices due to their unprecedented material and performance attributes. The surface finish, replication quality and material shrinkage are of immense importance for moulded ceramic parts intended for precision applications....... The current paper presents a thorough investigation on the process of ceramic moulding where it systematically characterizes the surface replication and shrinkage behaviours of precision moulded ceramic components. The test parts are moulded from Catamold TZP-A which is Y2O3-stabilised ZrO2 having widespread...... distribution for the moulded ceramic parts is presented....

  12. A characteristic of design solutions for flask moulding lines

    OpenAIRE

    Fedoryszyn, A.

    2007-01-01

    Moulding machines used in manufacture of moulds from synthetic bentonite sands constitute basic equipment of mechanised stands, work centres, and production lines. In the present article, a short characteristic of this equipment was given, basing on the generally accepted criteria of classification taking into consideration novel design solutions and principles of cooperation between individual sub-assemblies. Moulding equipment offered by domestic producers was described with emphasis put on...

  13. Possibilities of utilizing used moulding and core sands by microwave treatment

    Directory of Open Access Journals (Sweden)

    K. Granat

    2011-01-01

    Full Text Available The paper presents a semi-industrial reactor designed for microwave utilization of waste moulds and cores made of moulding sandsprepared in furane resin technology. It was found that a possibility exists of effective incinerating this way prepared residues of coresseparated from moulding sands or waste moulds left after casting. The preliminary tests evidenced that microwave heating is an effectiveway of disposing waste moulding sands and the applied apparatus permits effective control of the microwave heating process. The special structure permitting rotations of charge material and proper selection of the generators working cycles guarantee significant speeding-up the process and its full stabilisation. Application of microwave heating for utilization of waste moulds and cores containing synthetic resins as binders ensures significant and measurable economical benefits resulting from shorter process time.

  14. The diversity of moulds in the candied salak (Salacca edulis Reinw.

    Directory of Open Access Journals (Sweden)

    RATNA SETYANINGSIH

    2002-07-01

    Full Text Available The aims of this research were to identify moulds in candied fruit within three varieties of salak (i.e. sleman, gading and pondoh, and to know the effect of sugar concentration added, the time of storage, and additional of preservative chemical substance (benzoic acid for the diversity of moulds in candied salak. The isolation method of moulds was used direct plating. In order to determine the kind of moulds, which tolerance in sugar solution (osmotic pressure, the samples were put on the surface of glucose 25% peptone yeast-extract agar (GPYA medium, and then incubated at 30oC for seven days. After that the colony was transferred on potato dextrose agar (PDA and czapeks dox agar (CDA identification media. The results indicated that there were 10 different kind of moulds can be found in all samples, namely Aspergillus flavus, A, niger, A. versicolor, A. fumigatus, Aspergillus sp., Monilia sp., Mucor sp., Penicillium sp., Rhizopus sp. and Wallemia sp. In order to examine the influence of sugar concentration on the growth of moulds, the candied salaks were treated in different concentration. Candied salak with or without additional benzoic acid were treated with sugar concentration of 200 g/l, 250 g/l and 300 g/l. The highest concentration of sugar showed to lowest diversity of moulds for varieties of sleman and gading, conversely for variety of salak pondoh, the additional of high sugar concentration showed increase in their diversity. The diversity of moulds in day of seventh was smaller than the diversity of moulds in day of null. The concentration of benzoic acid (1 g/l confined the diversity of moulds.

  15. Bond strength of two component injection moulded MID

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2006-01-01

    Most products of the future will require industrially adapted, cost effective production processes and on this issue two-component (2K) injection moulding is a potential candidate for MID manufacturing. MID based on 2k injection moulded plastic part with selectively metallised circuit tracks allows...... the two different plastic materials in the MID structure require good bonding between them. This paper finds suitable combinations of materials for MIDs from both bond strength and metallisation view-point. Plastic parts were made by two-shot injection moulding and the effects of some important process...... the integration of electrical and mechanical functionalities in a real 3D structure. If 2k injection moulding is applied with two polymers, of which one is plateable and the other is not, it will be possible to make 3D electrical structures directly on the component. To be applicable in the real engineering field...

  16. DETACHMENT OF HUMAN FIBROBLASTS FROM FEP-TEFLON SURFACES

    NARCIS (Netherlands)

    VANKOOTEN, TG; SCHAKENRAAD, JM; VANDERMEI, HC; BUSSCHER, HJ

    1991-01-01

    In this study a comparison is made between the detachment behavior of human fibroblasts adhered to hydrophobic FEP-Teflon (water contact angle 109 degrees) and to hydrophilic glass (water contact angle smaller than 15 degrees) during exposure to a laminar, incrementally loaded flow. Detachment from

  17. Assessment methods of injection moulded nano-patterned surfaces

    DEFF Research Database (Denmark)

    Menotti, S.; Bisacco, G.; Hansen, H. N.

    2014-01-01

    algorithm for feature recognition. To compare the methods, the mould insert and a number of replicated nano-patterned surfaces, injection moulded with an induction heating aid, were measured on nominally identical locations by means of an atomic force microscope mounted on a manual CMM....

  18. Sharp tipped plastic hollow microneedle array by microinjection moulding

    Science.gov (United States)

    Yung, K. L.; Xu, Yan; Kang, Chunlei; Liu, H.; Tam, K. F.; Ko, S. M.; Kwan, F. Y.; Lee, Thomas M. H.

    2012-01-01

    A method of producing sharp tipped plastic hollow microneedle arrays using microinjection moulding is presented in this paper. Unlike traditional approaches, three mould inserts were used to create the sharp tips of the microneedles. Mould inserts with low surface roughness were fabricated using a picosecond laser machine. Sharp tipped plastic hollow microneedles 500 µm in height were fabricated using a microinjection moulding machine developed by the authors’ group. In addition, the strength of the microneedle was studied by simulation and penetration experiments. Results show that the microneedles can penetrate into skin, delivering liquid successfully without any breakage or severe deformation. Techniques presented in this paper can be used to fabricate sharp tipped plastic hollow microneedle arrays massively with low cost.

  19. Sharp tipped plastic hollow microneedle array by microinjection moulding

    International Nuclear Information System (INIS)

    Yung, K L; Xu, Yan; Kang, Chunlei; Liu, H; Tam, K F; Ko, S M; Kwan, F Y; Lee, Thomas M H

    2012-01-01

    A method of producing sharp tipped plastic hollow microneedle arrays using microinjection moulding is presented in this paper. Unlike traditional approaches, three mould inserts were used to create the sharp tips of the microneedles. Mould inserts with low surface roughness were fabricated using a picosecond laser machine. Sharp tipped plastic hollow microneedles 500 µm in height were fabricated using a microinjection moulding machine developed by the authors’ group. In addition, the strength of the microneedle was studied by simulation and penetration experiments. Results show that the microneedles can penetrate into skin, delivering liquid successfully without any breakage or severe deformation. Techniques presented in this paper can be used to fabricate sharp tipped plastic hollow microneedle arrays massively with low cost. (paper)

  20. Derailed self-constructions

    DEFF Research Database (Denmark)

    Sørensen, Niels Ulrik; Nielsen, Jens Christian

    2017-01-01

    The chapter focuses on the construction of self amongst a group of young boys in Denmark who have had experience with eating disorders, self- harm, loneli-ness and other manifestations of a lack of well- being. At first glance, these manifestations of a lack of well- being seem rather distinct...... and incomparable, but they have in common the fact that the young boys who have had these experiences say that they are due to personal faults and imperfections. In other words, they are related to problematizing thematizations of the self. In the chapter, we investigate these problematizing thematizations...... and explore the ways that young boys understand and experience the self, and how they link this self to their lack of well-being. As will become apparent, fear of marginalization seems to be an important part of this connection: The young boys are struggling to live up to expectations in an increasingly...

  1. Optimization of injection moulding process parameters in the ...

    African Journals Online (AJOL)

    In this study, optimal injection moulding conditions for minimum shrinkage during moulding of High Density Polyethylene (HDPE) were obtained by Taguchi method. The result showed that melting temperature of 190OC, injection pressure of 55 MPa, refilling pressure of 85 MPa and cooling time of 11 seconds gave ...

  2. Advances in Physarum machines sensing and computing with Slime mould

    CERN Document Server

    2016-01-01

    This book is devoted to Slime mould Physarum polycephalum, which is a large single cell capable for distributed sensing, concurrent information processing, parallel computation and decentralized actuation. The ease of culturing and experimenting with Physarum makes this slime mould an ideal substrate for real-world implementations of unconventional sensing and computing devices The book is a treatise of theoretical and experimental laboratory studies on sensing and computing properties of slime mould, and on the development of mathematical and logical theories of Physarum behavior. It is shown how to make logical gates and circuits, electronic devices (memristors, diodes, transistors, wires, chemical and tactile sensors) with the slime mould. The book demonstrates how to modify properties of Physarum computing circuits with functional nano-particles and polymers, to interface the slime mould with field-programmable arrays, and to use Physarum as a controller of microbial fuel cells. A unique multi-agent model...

  3. Surface micro topography replication in injection moulding

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf

    Thermoplastic injection moulding is a widely used industrial process that involves surface generation by replication. The surface topography of injection moulded plastic parts can be important for aesthetical or technical reasons. With the emergence of microengineering and nanotechnology additional...... importance of surface topography follows. In general the replication is not perfect and the topography of the plastic part differs from the inverse topography of the mould cavity. It is desirable to be able to control the degree of replication perfection or replication quality. This requires an understanding...... of the physical mechanisms of replication. Such understanding can lead to improved process design and facilitate in-line process quality control with respect to surface properties. The purpose of the project is to identify critical factors that affect topography replication quality and to obtain an understanding...

  4. Characterization of moulds associated with processed garri stored ...

    African Journals Online (AJOL)

    Characterization of moulds associated with processed white and yellow garri stored at ambient temperature for 40 days was investigated. The moulds isolated from white garri (%) were: Aspergillus spp 35.3, Penicillium spp 23.53, Fusarium spp 2.94, Mucor spp 17.65, Alternaria spp 5.88, Cladosporium sp 2.94 and ...

  5. A comparison of results for samples collected with bailers constructed of different materials

    International Nuclear Information System (INIS)

    Thomey, N.; Ogle, R.; Jackson, J.

    1992-01-01

    A bailer is one of the most common sampling devices used to collect ground water samples. Bailers constructed from various materials are available; teflon, polyvinyl chloride (PVC), polyethylene, and stainless steel are all commonly used. It is widely recognized that sample results can be affected by the material from which the bailer is constructed. Teflon and stainless steel are usually recommended based upon their inert properties. The cost of these bailers is significantly higher than other types. For the purposes of petroleum storage tank investigations, sampling devices that would not compromise sample quality but be more economical than teflon or stainless steel would be especially desirable. Water samples were collected using the different types of bailers; teflon, stainless steel, PVC, and polyethylene. Split samples were analyzed for benzene, toluene, ethylbenzene, total xylenes, and Total Petroleum Hydrocarbons. The analytical results were compared to determine if differences were due to normal analytical variances or due to interaction of the sample with the sampling device. No difference was noted in the results which were obtained

  6. Comparison of test methods for mould growth in buildings

    DEFF Research Database (Denmark)

    Bonderup, Sirid; Gunnarsen, Lars Bo; Knudsen, Sofie Marie

    2016-01-01

    renovation needs. This is of importance when hidden surface testing would require destructive measures and subsequent renovation. After identifying available methods on the Danish market for assessing mould growth in dwellings, a case study was conducted to test the usefulness of the methods in four......The purpose of this work is to compare a range of test methods and kits for assessing whether a building structure is infested by mould fungi. A further purpose of this work is to evaluate whether air-based methods for sampling fungal emissions provide information qualifying decisions concerning...... methods measure different aspects relating to mould growth and vary in selectivity and precision. The two types of air samples indicated low levels of mould growth, even where the results of the other methods indicated high to moderate growth. With methods based on culture and DNA testing some differences...

  7. Compression and Injection Moulding of Nano-Structured Polymer Surfaces

    DEFF Research Database (Denmark)

    Pranov, Henrik; Rasmussen, Henrik Koblitz

    2006-01-01

    In our research we investigate the non-isothermal replication of complex nano and micro surface structures in injection and compression moulding.......In our research we investigate the non-isothermal replication of complex nano and micro surface structures in injection and compression moulding....

  8. Synchrotron Vacuum Ultraviolet Light and Soft X-Ray Radiation Effects on Aluminized Teflon FEP Investigated

    Science.gov (United States)

    Dever, Joyce A.; Townsend, Jacqueline A.; Gaier, James R.; Jalics, Alice I.

    1999-01-01

    Since the Hubble Space Telescope (HST) was deployed in low Earth orbit in April 1990, two servicing missions have been conducted to upgrade its scientific capabilities. Minor cracking of second-surface metalized Teflon FEP (DuPont; fluorinated ethylene propylene) surfaces from multilayer insulation (MLI) was first observed upon close examination of samples with high solar exposure retrieved during the first servicing mission, which was conducted 3.6 years after deployment. During the second HST servicing mission, 6.8 years after deployment, astronaut observations and photographic documentation revealed significant cracks in the Teflon FEP layer of the MLI on both the solar- and anti-solar-facing surfaces of the telescope. NASA Goddard Space Flight Center directed the efforts of the Hubble Space Telescope MLI Failure Review Board, whose goals included identifying the low-Earth-orbit environmental constituent(s) responsible for the cracking and embrittling of Teflon FEP which was observed during the second servicing mission. The NASA Lewis Research Center provided significant support to this effort. Because soft x-ray radiation from solar flares had been considered as a possible cause for the degradation of the mechanical properties of Teflon FEP (ref. 1), the effects of soft xray radiation and vacuum ultraviolet light on Teflon FEP were investigated. In this Lewisled effort, samples of Teflon FEP with a 100-nm layer of vapor-deposited aluminum (VDA) on the backside were exposed to synchrotron radiation of various vacuum ultraviolet and soft x-ray wavelengths between 18 nm (69 eV) and 0.65 nm (1900 eV). Synchrotron radiation exposures were conducted using the National Synchrotron Light Source at Brookhaven National Laboratory. Samples of FEP/VDA were exposed with the FEP surface facing the synchrotron beam. Doses and fluences were compared with those estimated for the 20-yr Hubble Space Telescope mission.

  9. DEVELOPMENT OF FLUORINE-FREE MOULD FLUX APPLIED IN LOW CARBON STEEL

    Directory of Open Access Journals (Sweden)

    Jayme Alves de Souza Junior

    2012-12-01

    Full Text Available ract The mould flux is a mixture of non-metallic oxides that, in contact with liquid steel melts, becomes a liquid slag which the mainly function is to lubricate and control heat transfer between mould and strand during the continuous casting process. The mould flux without fluoride has the advantage of decreasing the wear of machine and the SEN in comparison to common mould flux. The application in Continuous Casting of Slabs has been a great challenge in relation to the operational viability together with internal and surface quality of slabs. Another differential is the decrease of environmental issues on account of the contamination of secondary cooling water by the fluorides. It is considered that properties of mould flux as chemical composition, viscosity, softening, melting flowing temperatures, fusion rate, etc, should be suitable to the chemical composition and the mechanical properties at elevated temperatures of steel and also the operational parameters such as casting temperature, casting speed, mould frequency, among others. This work presents a preliminary analysis in relation to operational viability, analysis of surface quality of slabs, measurements of fluorides content in the water of secondary cooling of machine. In addition to that, the analyses of operational features as measurements of wear of SEN, mould flux consumption, slag pool and behavior of thermocouples of detection system break outs (MSD are considered.

  10. Inner centering in parting line area of injection mould using side locks

    DEFF Research Database (Denmark)

    Mahshid, Rasoul; Hansen, Hans Nørgaard

    2017-01-01

    Injection moulding is characterized by high precision requirements. In particular, the demands regarding the mould plates alignment are in order of few micro meters. This research introduces a methodology to measure the misalignment in injection moulding. Eddy current sensors are used in the system...

  11. The first report on mushroom green mould disease in Croatia.

    Science.gov (United States)

    Hatvani, Lóránt; Sabolić, Petra; Kocsubé, Sándor; Kredics, László; Czifra, Dorina; Vágvölgyi, Csaba; Kaliterna, Joško; Ivić, Dario; Đermić, Edyta; Kosalec, Ivan

    2012-12-01

    Green mould disease, caused by Trichoderma species, is a severe problem for mushroom growers worldwide, including Croatia. Trichoderma strains were isolated from green mould-affected Agaricus bisporus (button or common mushroom) compost and Pleurotus ostreatus (oyster mushroom) substrate samples collected from Croatian mushroom farms. The causal agents of green mould disease in the oyster mushroom were T. pleurotum and T. pleuroticola, similar to other countries. At the same time, the pathogen of A. bisporus was exclusively the species T. harzianum, which is different from earlier findings and indicates that the range of mushroom pathogens is widening. The temperature profiles of the isolates and their hosts overlapped, thus no range was found that would allow optimal growth of the mushrooms without mould contamination. Ferulic acid and certain phenolic compounds, such as thymol showed remarkable fungistatic effect on the Trichoderma isolates, but inhibited the host mushrooms as well. However, commercial fungicides prochloraz and carbendazim were effective agents for pest management. This is the first report on green mould disease of cultivated mushrooms in Croatia.

  12. Cavity Pressure Behaviour in Micro Injection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.

    2010-01-01

    as well as with the filling of the cavity by the polymer melt. In this paper, two parameters derived from cavity pressure over time (i.e. pressure work). The influence of four µIM parameters (melt temperature, mould temperature, injection speed, aand packing pressure) on the two pressure-related outputs...... has been investigated by moulding a micro fluidic component on three different polymers (PP, ABS, PC) using the design of experiment approach. Similar trends such as the effects of a higher injection speed in decreasing the pressure work and of a lower temperature in decreasing pressure rate have been......Process monitoring of micro injection moulding (µIM) is of crusial importance to analyse the effect of different parameter settings on the process and to assess its quality. Quality factors related to cavity pressure can provide useful information directly connected with the dyanmics of the process...

  13. Combined conduction and radiation with phase change in teflon slabs

    International Nuclear Information System (INIS)

    Shih, T.M.; Hsu, I.C.; Cunnington, G.R. Jr.

    1986-01-01

    A new approach to investigate, numerically, an one-dimensional Stefan problem with combined radiation and conduction has been developed. This numerical scheme is a modified version of the heat flux method and the scheme tracks the moving phase changing interface by coordinate transformation. The physical problem involves the radiative heating on one side of a Teflon slab; causing the material to melt and sublime as the melt-solid interface recedes. The other side of the Teflon slab is insulated. The results of this numerical scheme has been compared with results reported in the literature; before attempting to use this scheme to predict the experimental data. Satisfactory agreement between numerical results and the results in the literature as well as the experimental data has been obtained in both comparisons

  14. Evaluation of wettability of binders used in moulding sands

    Directory of Open Access Journals (Sweden)

    Hutera B.

    2007-01-01

    Full Text Available Binders used in moulding sand have the differential properties. One of the main parameters influencing on moulding sand properties is wettability of the sand grain by binding material. In the article some problems concerned with wettability evaluation have been presented and the importance of this parameter for quantity description of process occurring in system: binder- sand grain has been mentioned. The procedure of wetting angle measurement and operation of prototype apparatus for wettability investigation of different binders used in moulding sand have been described, as well as the results of wetting angle measurement for different binders at different conditions. The addition of little amount of proper diluent to binder results in the state of equilibrium reached almost immediately. Such addition can also reduce the value of equilibrium contact angle. The uniform distribution of binder on the surface of the sand grains and reducing of the required mixing time can be obtained. It has also a positive effect on the moulding sand strength.

  15. Two-component microinjection moulding for MID fabrication

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2010-01-01

    Moulded interconnect devices (MIDs) are plastic substrates with electrical infrastructure. The fabrication of MIDs is usually based on injection moulding, and different process chains may be identified from this starting point. The use of MIDs has been driven primarily by the automotive sector......, but recently, the medical sector seems more and more interested. In particular, the possibility of miniaturisation of three-dimensional components with electrical infrastructure is attractive. The present paper describes possible manufacturing routes and challenges of miniaturised MIDs based on two...

  16. 42 CFR 137.275 - May Self-Governance Tribes include IHS construction programs in a construction project agreement...

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false May Self-Governance Tribes include IHS construction... OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Construction Purpose and Scope § 137.275 May Self-Governance Tribes include IHS construction programs in a construction project agreement or in a funding...

  17. Studies on mould growth and biomass production using waste banana peel.

    Science.gov (United States)

    Essien, J P; Akpan, E J; Essien, E P

    2005-09-01

    Hyphomycetous (Aspergillus fumigatus) and Phycomycetous (Mucor hiemalis) moulds were cultivated in vitro at room temperature (28 + 20 degrees C) to examined their growth and biomass production on waste banana peel agar (BPA) and broth (BPB) using commercial malt extract agar (MEA) and broth (MEB) as control. The moulds grew comparatively well on banana peel substrates. No significant difference (p > 0.05) in radial growth rates was observed between moulds cultivated on PBA and MEA, although growth rates on MEA were slightly better. Slight variations in sizes of asexual spores and reproductive hyphae were also observed between moulds grown on MEA and BPA. Smaller conidia and sporangiospores, and shorter aerial hyphae (conidiophores and sporangiophores) were noticed in moulds grown on BPA than on MEA. The biomass weight of the test moulds obtained after one month of incubation with BPB were only about 1.8 mg and 1.4 mg less than values recorded for A. fumigatus and M. hiemalis respectively, grown on MEB. The impressive performance of the moulds on banana peel substrate may be attributed to the rich nutrient (particularly the crude protein 7.8% and crude fat 11.6% contents) composition of banana peels. The value of this agricultural waste can therefore be increased by its use not only in the manufacture of mycological medium but also in the production of valuable microfungal biomass which is rich in protein and fatty acids.

  18. Development tendencies of moulding and core sands

    Directory of Open Access Journals (Sweden)

    Stanislaw M. Dobosz1

    2011-11-01

    Full Text Available Further development of the technology for making moulding and core sands will be strictly limited by tough requirements due to protection of the natural environment. These tendencies are becoming more and more tense, so that we will reach a point when even processes, that from technological point of view fulfill high requirements of the foundry industry, must be replaced by more ecologically-friendly solutions. Hence, technologies using synthetic resins as binding materials will be limited. This paper presents some predictable development tendencies of moulding and core sands. The increasing role of inorganic substances will be noticed, including silicate binders with significantly improved properties, such as improved knock-out property or higher reclamation strength. Other interesting solutions might also be moulding sands bonded by geo-polymers and phosphate binders or salts and also binders based on degradable biopolymers. These tendencies and the usefulness of these binders are put forward in this paper.

  19. Nylon and teflon scribe effect on NBR to Chemlok 233 and NBR to NBR bond interfaces

    Science.gov (United States)

    Jensen, S. K.

    1990-01-01

    A study was requested by Manufacturing Engineering to determine what effects marking with nylon (6/6) and Teflon scribes may have on subsequent bonding. Witness panel bond specimens were fabricated by the development lab to test both acrylonitrile butadiene rubber (NBR) to Chemlok and NBR to NBR after controlled exposure. The nylon rod used as a scribe tool demonstrates virtually no bond deterioration when used to scribe lines on either the Chemlok to NBR surfaces or the NBR to NBR interface. Lab test results indicate that the nylon rod-exposed samples produce tensile and peel values very similar to the control samples and the Teflon exposed samples produce tensile and peel values much lower than the control samples. Visual observation of the failure surfaces of the tested samples shows that Teflon scribing produces an obvious contamination to the surface and the nylon produces no effect. Photographs of test samples are provided. It is concluded that Teflon stock used as a scribe tool on a Chemlok 233 to NBR surface or an NBR to NBR surface has a detrimental effect on the bond integrity on either of these bond interfaces. Therefore, it is recommended that the nylon rod continue to be used where a scribe line is required in the redesigned solid rocket motor segment insulation layup operations. The use of Teflon scribes should not be considered.

  20. Modeling of Flexible Polyurethane Foam Shrinkage for Bra Cup Moulding Process Control

    Directory of Open Access Journals (Sweden)

    Long Wu

    2018-04-01

    Full Text Available Nowadays, moulding technology has become a remarkable manufacturing process in the intimate apparel industry. Polyurethane (PU foam sheets are used to mould three-dimensional (3D seamless bra cups of various softness and shapes, which eliminate bulky seams and reduce production costs. However, it has been challenging to accurately and effectively control the moulding process and bra cup thickness. In this study, the theoretical mechanism of heat transfer and the thermal conductivity of PU foams are first examined. Experimental studies are carried out to investigate the changes in foam materials at various moulding conditions (viz., temperatures, and lengths of dwell time in terms of surface morphology and thickness by using electron and optical microscopy. Based on the theoretical and experimental investigations of the thermal conductivity of the foam materials, empirical equations of shrinkage ratio and thermal conduction of foam materials were established. A regression model to predict flexible PU foam shrinkage during the bra cup moulding process was formulated by using the Levenberg-Marquardt method of nonlinear least squares algorithm and verified for accuracy. This study therefore provides an effective approach that optimizes control of the bra cup moulding process and assures the ultimate quality and thickness of moulded foam cups.

  1. Best practice strategies for validation of micro moulding process simulation

    DEFF Research Database (Denmark)

    Costa, Franco; Tosello, Guido; Whiteside, Ben

    2009-01-01

    The use of simulation for injection moulding design is a powerful tool which can be used up-front to avoid costly tooling modifications and reduce the number of mould trials. However, the accuracy of the simulation results depends on many component technologies and information, some of which can...... be easily controlled or known by the simulation analyst and others which are not easily known. For this reason, experimental validation studies are an important tool for establishing best practice methodologies for use during analysis set up on all future design projects. During the validation studies......, detailed information about the moulding process is gathered and used to establish these methodologies. Whereas in routine design projects, these methodologies are then relied on to provide efficient but reliable working practices. Data analysis and simulations on preliminary micro-moulding experiments have...

  2. Self-identity as a construct

    DEFF Research Database (Denmark)

    Sudzina, Frantisek

    Self-identity is a private assessment of one’s beliefs and values. The self is an active agent in the decision process that drives people to act in accordance with the behavior that they see appropriate for themselves. According to Triandis, one’s self-definition motivates behavior that is consis......Self-identity is a private assessment of one’s beliefs and values. The self is an active agent in the decision process that drives people to act in accordance with the behavior that they see appropriate for themselves. According to Triandis, one’s self-definition motivates behavior...... that is consistent with that definition. Self-identity has been shown to influence the acceptance and use of technology. Prior research has shown that self-identity includes the factors of innovativeness, tech savviness, and opinion leadership. The aim of the research is to test the self-identity construct...

  3. Asking 'why' from a distance facilitates emotional processing: a reanalysis of Wimalaweera and Moulds (2008).

    Science.gov (United States)

    Ayduk, Ozlem; Kross, Ethan

    2009-01-01

    Wimalaweera and Moulds [Wimalaweera, S. W., & Moulds, M. L. (2008). Processing memories of anger-eliciting events: the effect of asking 'why' from a distance. Behaviour Research and Therapy, 46, 402-409] reported a failure to replicate previous findings demonstrating the effectiveness of analyzing anger-related experiences from a self-distanced perspective for reducing negative affect in the short-term (Ayduk, O., & Kross, E. (2008). [Enhancing the pace of recovery: self-distanced-analysis of negative experiences reduces blood pressure reactivity. Psychological Science, 9(3), 229-231; Kross, E., Ayduk, O., & Mischel, W. (2005). When asking "why" does not hurt. Psychological Science, 16, 709-715.] and facilitating adaptive emotional processing over time [Kross, E., & Ayduk, O. (2008). Facilitating adaptive emotional analysis: distinguishing distanced-analysis of depressive experiences from immersed-analysis and distraction. Personality and Social Psychology Bulletin]. A reanalysis of their data that takes into account effect sizes and participants' scores on the avoidance subscale of the Impact of Events Scale, which were not reported in the original write-up, contradict this and a number of other conclusions reported in their article. In this article, we review the key findings that emerged from this reanalysis.

  4. Hearing improvement after stapedotomy using teflon loop prosthesis

    International Nuclear Information System (INIS)

    Ahmed, S.; Raza, N.

    2006-01-01

    To assess hearing improvement after stapedotomy for otosclerosis using teflon loop prosthesis. Thirty diagnosed cases of otosclerosis were included in the study. Ear with greater air-bone gap was selected and stapedotomy was done using teflon loop prosthesis (size 4 - 4.5 mm). Mild vertigo occurred during immediate postoperative period, which subsided with Inj. Prochlorperazine. Patients were followed-up postsurgically at one month, two months, four months, six months and one year and postoperative air-bone gap was calculated. Out of 30 cases, there were 24 males and 06 females. The age ranged from 18 to 50 years. Twenty-one (70%) patients had bilateral hearing loss and 09 (30%) had tinnitis also. Pre-operative audiograms showed conductive deafness. Carhart's notch was present in 10 (33.3%) cases. Tympanogram revealed loss of stapedial reflex. Postoperatively good hearing improvement was seen in 56.7% (postoperative air-bone gap closure upto 10 dB), fair improvement in 30% (postoperative air bone gap closure from 11 to 20 dB) and poor results in 10% (postoperative air-bone gap more than 21 dB) cases. One patient developed dead ear. (author)

  5. Exercise in injection moulding: Predicting the non-uniform shrinkage from PVT data

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Eriksson, Torbjörn Gerhard

    Injection moulding is a widely spread technique for producing plastic parts of many kinds, for example bowls, chairs, coverings for mobile phones etc. The basic principle of injection moulding is to inject molten plastic into a closed, cooled mould (i. e. tool), where it solidifies to give......) is manufactured using two types of commercial plastics (Polypropylene (PP) and Polycarbonate (PC)). Pressure transducers measure the pressure in the mould during the injection and the solidification. The temperature is measured by inserting a thermometer in the plastic melt. The difference in dimensions between...... the product. The product is recovered by opening the mould to release it. The quality of the product is highly dependent on tool design, process parameters such as pressure and temperature and which type of polymer that is used. Here, a plastic bar with four indentions (in the form of parallel lines...

  6. High Accuracy Three-dimensional Simulation of Micro Injection Moulded Parts

    DEFF Research Database (Denmark)

    Tosello, Guido; Costa, F. S.; Hansen, Hans Nørgaard

    2011-01-01

    Micro injection moulding (μIM) is the key replication technology for high precision manufacturing of polymer micro products. Data analysis and simulations on micro-moulding experiments have been conducted during the present validation study. Detailed information about the μIM process was gathered...

  7. Two-component micro injection moulding for hearing aid applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Marhöfer, David Maximilian

    2012-01-01

    . The moulding machine was a state-of-the-art 2k micro machine from DESMA. The fabricated micro part was a socket house integrated with a sealing ring for the receiver-in-canal hearing instrument. The test performed on the demonstrator showed the potential of the 2k moulding technology to be able to solve some...

  8. Galactomyces geotrichum – moulds from dairy products with high biotechnological potential

    OpenAIRE

    Anna Grygier; Kamila Myszka; Magdalena Rudzińska

    2017-01-01

    The article reviews the properties of the Galactomyces geotrichum species, the mould that is most important for the dairy industry. G. geotrichum mould has been isolated from milk, cheeses and alcoholic beverage. Its presence in food products makes it possible to obtain a characteristic aroma and taste, which corresponds to the needs and preferences of consumers. G. geotrichum plays an important role in ecology, where the mould is employed for the degradation of various hazardous substances a...

  9. Comparison of PIXE and XRF analysis of airborne particulate matter samples collected on Teflon and quartz fibre filters

    Science.gov (United States)

    Chiari, M.; Yubero, E.; Calzolai, G.; Lucarelli, F.; Crespo, J.; Galindo, N.; Nicolás, J. F.; Giannoni, M.; Nava, S.

    2018-02-01

    Within the framework of research projects focusing on the sampling and analysis of airborne particulate matter, Particle Induced X-ray Emission (PIXE) and Energy Dispersive X-ray Fluorescence (ED-XRF) techniques are routinely used in many laboratories throughout the world to determine the elemental concentration of the particulate matter samples. In this work an inter-laboratory comparison of the results obtained from analysing several samples (collected on both Teflon and quartz fibre filters) using both techniques is presented. The samples were analysed by PIXE (in Florence, at the 3 MV Tandetron accelerator of INFN-LABEC laboratory) and by XRF (in Elche, using the ARL Quant'X EDXRF spectrometer with specific conditions optimized for specific groups of elements). The results from the two sets of measurements are in good agreement for all the analysed samples, thus validating the use of the ARL Quant'X EDXRF spectrometer and the selected measurement protocol for the analysis of aerosol samples. Moreover, thanks to the comparison of PIXE and XRF results on Teflon and quartz fibre filters, possible self-absorption effects due to the penetration of the aerosol particles inside the quartz fibre-filters were quantified.

  10. Changes of gas pressure in sand mould during cast iron pouring

    Directory of Open Access Journals (Sweden)

    J. Mocek

    2011-10-01

    Full Text Available The paper presents a test method developed to measure changes of gas pressure in sand moulds during manufacture of iron castings. The pressure and temperature measurements were taken in the sand mould layers directly adjacent to the metal – mould interface. A test stand was described along with the measurement methodology. The sensors used allowed studying the fast-changing nature of the processes which give rise to the gas-originated casting defects. The study examined the influence of binders, clays and refining additives on the nature of the gas evolution process. The effect of the base sand type - quartz or olivine - on the nature of pressure changes was compared. The test stand design ensured the stability of technological parameters in the examined mould elements, and a repeatable process of making pilot castings. The main outcome was classification of sand mixtures in terms of pressure occurring during pouring of iron castings. The obtained results confirm the usefulness of the described method for testing gas pressure occurrence in a sand mould.

  11. Fungi associated with black mould on baobab trees in southern Africa.

    Science.gov (United States)

    Cruywagen, Elsie M; Crous, Pedro W; Roux, Jolanda; Slippers, Bernard; Wingfield, Michael J

    2015-07-01

    There have been numerous reports in the scientific and popular literature suggesting that African baobab (Adansonia digitata) trees are dying, with symptoms including a black mould on their bark. The aim of this study was to determine the identity of the fungi causing this black mould and to consider whether they might be affecting the health of trees. The fungi were identified by sequencing directly from mycelium on the infected tissue as well as from cultures on agar. Sequence data for the ITS region of the rDNA resulted in the identification of four fungi including Aureobasidium pullulans, Toxicocladosporium irritans and a new species of Rachicladosporium described here as Rachicladosporium africanum. A single isolate of an unknown Cladosporium sp. was also found. These fungi, referred to here as black mould, are not true sooty mould fungi and they were shown to penetrate below the bark of infected tissue, causing a distinct host reaction. Although infections can lead to dieback of small twigs on severely infected branches, the mould was not found to kill trees.

  12. The Compositions: Biodegradable Material - Typical Resin, as Moulding Sands’ Binders

    Directory of Open Access Journals (Sweden)

    Major-Gabryś K.

    2015-03-01

    Full Text Available The paper presents possibility of using biodegradable materials as parts of moulding sands’ binders based on commonly used in foundry practice resins. The authors focus on thermal destruction of binding materials and thermal deformation of moulding sands with tested materials. All the research is conducted for the biodegradable material and two typical resins separately. The point of the article is to show if tested materials are compatible from thermal destruction and thermal deformation points of view. It was proved that tested materials characterized with similar thermal destruction but thermal deformation of moulding sands with those binders was different.

  13. Three dimensions thermal-mechanical model of the billet in continuous casting petal-like mould

    International Nuclear Information System (INIS)

    Li Jing; Wu Li; Cao Zhiqiang; Tingju, L; Wang Tongmin

    2012-01-01

    Petal-like mould is a novel mould which has been applied to the steel industry in recent years. The behavior of the petal-like billet in continuous casting mould plays an important role in designing mould. It is hard to be in situ measured during continuous casting, however, can be worked out by the way of numerical simulation. But the research about the model of the billet in petal-like mould is very little. A 3D finite-element model has been built to simulate the thermal and stress fields of the molten steel in petal-like mould in this paper. The dynamic thermal boundary condition and the effect of ferrostatic pressure have been considered in the model. The temperature and stress in the billet have been predicted by this model.

  14. High-temperature expansion and knock-out properties of moulding sands with water glass

    Directory of Open Access Journals (Sweden)

    Major-Gabryś K.

    2007-01-01

    Full Text Available The article focuses on the topic of improving the knock-out properties of moulding sand with water glass and ester hardener. It is settled that the cause of worse knock-out properties of moulding sand can be brought by their thermal expansion in increased temperatures. There is a presentation of the influence of different additives, containing Al2O3, on moulding sands’ expansion in increased temperatures. Within the frames of research, there was an elaboration of the influence of authors own additive- Glassex, on the expansion phenomenon of moulding sands with water glass and ester hardener. It is concluded, that the new additive stops the expansion of moulding sands and as well it improves their knock-out properties.

  15. GTE blade injection moulding modeling and verification of models during process approbation

    Science.gov (United States)

    Stepanenko, I. S.; Khaimovich, A. I.

    2017-02-01

    The simulation model for filling the mould was developed using Moldex3D, and it was experimentally verified in order to perform further optimization calculations of the moulding process conditions. The method described in the article allows adjusting the finite-element model by minimizing the airfoil profile difference between the design and experimental melt motion front due to the differentiated change of power supplied to heating elements, which heat the injection mould in simulation. As a result of calibrating the injection mould for the gas-turbine engine blade, the mean difference between the design melt motion profile and the experimental airfoil profile of no more than 4% was achieved.

  16. Warpage analysis in injection moulding process

    Science.gov (United States)

    Hidayah, M. H. N.; Shayfull, Z.; Nasir, S. M.; Fathullah, M.; Hazwan, M. H. M.

    2017-09-01

    This study was concentrated on the effects of process parameters in plastic injection moulding process towards warpage problem by using Autodesk Moldflow Insight (AMI) software for the simulation. In this study, plastic dispenser of dental floss has been analysed with thermoplastic material of Polypropylene (PP) used as the moulded material and details properties of 80 Tonne Nessei NEX 1000 injection moulding machine also has been used in this study. The variable parameters of the process are packing pressure, packing time, melt temperature and cooling time. Minimization of warpage obtained from the optimization and analysis data from the Design Expert software. Integration of Response Surface Methodology (RSM), Center Composite Design (CCD) with polynomial models that has been obtained from Design of Experiment (DOE) is the method used in this study. The results show that packing pressure is the main factor that will contribute to the formation of warpage in x-axis and y-axis. While in z-axis, the main factor is melt temperature and packing time is the less significant among the four parameters in x, y and z-axes. From optimal processing parameter, the value of warpage in x, y and z-axis have been optimised by 21.60%, 26.45% and 24.53%, respectively.

  17. Femtosecond laser ablation of polytetrafluoroethylene (Teflon) in ambient air

    International Nuclear Information System (INIS)

    Wang, Z.B.; Hong, M.H.; Lu, Y.F.; Wu, D.J.; Lan, B.; Chong, T.C.

    2003-01-01

    Teflon, polytetrafluorethylene (PTFE), is an important material in bioscience and medical application due to its special characteristics (bio-compatible, nonflammable, antiadhesive, and heat resistant). The advantages of ultrashort laser processing of Teflon include a minimal thermal penetration region and low processing temperatures, precision removal of material, and good-quality feature definition. In this paper, laser processing of PTFE in ambient air by a Ti:sapphire femtosecond laser (780 nm, 110 fs) is investigated. It is found that the pulse number on each irradiated surface area must be large enough for a clear edge definition and the ablated depth increases with the pulse number. The air ionization effect at high laser fluences not only degrades the ablated structures quality but also reduces the ablation efficiency. High quality microstructures are demonstrated with controlling laser fluence below a critical fluence to exclude the air ionization effect. The ablated microstructures show strong adhesion property to liquids and clear edges that are suitable for bio-implantation applications. Theoretical calculation is used to analyze the evolution of the ablated width and depth at various laser fluences

  18. Laser cleaning of the contaminations on the surface of tire mould

    Science.gov (United States)

    Ye, Yayun; Jia, Baoshen; Chen, Jing; Jiang, Yilan; Tang, Hongping; Wang, Haijun; Luan, Xiaoyu; Liao, Wei; Zhang, Chuanchao; Yao, Caizhen

    2017-07-01

    During the manufacturing of tires, surface pollutants on tire mould will lead to the production of unqualified tires. Tire moulds need to be regularly cleaned. Laser cleaning is recognized as a non-destructive, effective, precise and environmental friendly method. In this paper, laser cleaning was used to remove contaminants on tire mould surface. First, laser induced damage experiments were performed. The results showed that the roughness and hardness of the cast steel sample surface seldom changed under the energy range of 140.1-580.2 mJ laser irradiation 1 pulse and the energy range of 44.7-168.9 mJ laser irradiation 100 pulses. In the laser cleaning experiments, the cleaning thresholds and the optimal cleaning parameters were obtained. Results indicated that laser cleaning was safe and effective for tire mould contamination removal.

  19. Hubble Space Telescope Metallized Teflon(registered trademark) FEP Thermal Control Materials: On-Orbit Degradation and Post-Retrieval Analysis

    Science.gov (United States)

    Townsend, Jacqueline A.; Hansen, Patricia A.; Dever, J. A.; deGroh, K. K.; Banks, B.; Wang, L.; He, C.

    1988-01-01

    During the Hubble Space Telescope (HST) Second Servicing Mission (SM2), degradation of unsupported Teflon(Registered Trademark) FEP (fluorinated ethylene propylene), used as the outer layer of the multilayer insulation (MLI) blankets, was evident as large cracks on the telescope light shield. A sample of the degraded outer layer was retrieved during the mission and returned to Earth for ground testing and evaluation. The results of the Teflon(Registered Trademark) FEP sample evaluation and additional testing of pristine Teflon(Registered Trademark) FEP led the investigative team to theorize that the HST damage was caused by thermal cycling with deep-layer damage from electron and proton radiation which allowed the propagation of cracks along stress concentrations , and that the damage increased with the combined total dose of electrons, protons, UV and x-rays along with thermal cycling. This paper discusses the testing and evaluation of the retrieved Teflon(Registered Trademark) FEP.

  20. Influence of Teflon substrate on crystallization and enzymatic degradation of polymorphic poly(butylene adipate)

    DEFF Research Database (Denmark)

    Ning, Zhenbo; Nielsen, Ronnie Bo Højstrup; Zhao, Lifen

    2014-01-01

    for PBA beta crystals between neither the oriented nor the non-oriented Teflon films. The enzymatic degradation rate of PBA films was not determined by the epitaxial crystallization, in fact it was still dependent on the polymorphic crystal structure of PBA. The morphological changes of PBA films after...... enzymatic degradation confirmed again that the epitaxial crystallization only occurred for the PBA film with alpha crystal structure which was produced by being sandwiched between oriented Teflon films, and it happened only on the surface of PBA films....

  1. Using special additions to preparation of the moulding mixture for casting steel parts of drive wheel type

    Science.gov (United States)

    Josan, A.; Pinca Bretotean, C.

    2015-06-01

    The paper presents the possibility of using special additions to the execution of moulding mixtures for steel castings, drive wheel type. Critical analysis of moulding technology leads to the idea that most defects appear due to using improper moulding mixture. Using a improper moulding mixture leads to penetration of steel in moulding mixture, resulting in the formation of adherences, due to inadequate refractarity of the mould and core mixtures. Using only the unique mixture to the moulding leads to increasing consumption of new sand, respectively to the increase of price of piece. Acording to the dates registered in the industrial practice is necessary to use the special additions to obtain the moulding mixtures, carbonaceous materials respectively.

  2. Millimeter-wave radiation from a Teflon dielectric probe and its imaging application

    International Nuclear Information System (INIS)

    Kume, Eiji; Sakai, Shigeki

    2008-01-01

    The beam profile of a millimeter wave radiated from the tip of a Teflon dielectric probe was characterized experimentally by using a three-dimensional scanning dielectric probe and numerically by using the finite difference time domain (FDTD) method. The measured intensity distribution and polarization of the millimeter wave radiated from the tip of the probe was in good agreement with those of the FDTD simulation. A reflection type of a millimeter- wave imaging system using this dielectric probe was constructed. The resolution of the imaging system was as small as 1 mm, which was slightly smaller than a half wavelength, 1.6 mm, of the radiation wave. Translucent measurement of a commercially manufactured IC card which consists of an IC chip and a leaf-shaped antenna coil was demonstrated. Not only the internal two-dimensional structures but also the vertical information of the card could be provided

  3. Galactomyces geotrichum - moulds from dairy products with high biotechnological potential.

    Science.gov (United States)

    Grygier, Anna; Myszka, Kamila; Rudzińska, Magdalena

    2017-01-01

    The article reviews the properties of the Galactomyces geotrichum species, the mould that is most important for the dairy industry. G. geotrichum mould has been isolated from milk, cheeses and alcoholic beverage. Its presence in food products makes it possible to obtain a characteristic aroma and taste, which corresponds to the needs and preferences of consumers. G. geotrichum plays an important role in ecology, where the mould is employed for the degradation of various hazardous substances and wastewater treatment. It has also been found to have potential for biofuel production. In addition to this, G. geotrichum can be applicable in two further major areas: agriculture and health protection.

  4. Measuring autogenous strain of concrete with corrugated moulds

    DEFF Research Database (Denmark)

    Tian, Qian; Jensen, Ole Mejlhede

    2008-01-01

    A reliable technique to quantify autogenous strain is a prerequisite to numerical modeling in stress calculations for high performance concrete. The introducing of a special kind of corrugated tube mould helps to transforming volume strain measurement into liner strain measurement in horizontal...... direction for fluid concrete, which not only realizes the continuous monitoring of the autogenous shrinkage since casting, but also effectively eliminates the disturbance resulting from gravity, temperature variation and mould restraint on measuring results. Based on this measuring technique, this paper...

  5. Emission of organic compounds from mould and core binders used for casting iron, aluminium and bronze in sand moulds

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat; Crepaz, Rudolf; Eggert, Torben

    2010-01-01

    compositions were tested. A test method that provides uniform test conditions is described. The method can be used as general test method to analyse off gasses from binders. Moulds containing a standard size casting were produced and the amount and type of organic compounds resulting from thermal degradation...... of binders was monitored when cast iron, bronze and aluminium was poured in the moulds. Binder degradation was measured by collecting off gasses in a specially designed ventilation hood at a constant flow rate. Samples were taken from the ventilation system and analysed for hydrocarbons and CO content...

  6. Gases Emission From Surface Layers of Sand Moulds and Cores Stored Under the Humid Air Conditions

    Directory of Open Access Journals (Sweden)

    Kaźnica N.

    2017-12-01

    Full Text Available A large number of defects of castings made in sand moulds is caused by gases. There are several sources of gases: gases emitted from moulds, cores or protective coatings during pouring and casting solidification; water in moulding sands; moisture adsorbed from surroundings due to atmospheric conditions changes. In investigations of gas volumetric emissions of moulding sands amounts of gases emitted from moulding sand were determined - up to now - in dependence of the applied binders, sand grains, protective coatings or alloys used for moulds pouring. The results of investigating gas volumetric emissions of thin-walled sand cores poured with liquid metal are presented in the hereby paper. They correspond to the surface layer in the mould work part, which is decisive for the surface quality of the obtained castings. In addition, cores were stored under conditions of a high air humidity, where due to large differences in humidity, the moisture - from surroundings - was adsorbed into the surface layer of the sand mould. Due to that, it was possible to asses the influence of the adsorbed moisture on the gas volumetric emission from moulds and cores surface layers by means of the new method of investigating the gas emission kinetics from thin moulding sand layers heated by liquid metal. The results of investigations of kinetics of the gas emission from moulding sands with furan and alkyd resins as well as with hydrated sodium silicate (water glass are presented. Kinetics of gases emissions from these kinds of moulding sands poured with Al-Si alloy were compared.

  7. Rheological and thermal analysis of the filling stage of injection moulding

    Directory of Open Access Journals (Sweden)

    A. Szucs

    2012-08-01

    Full Text Available Flow conditions are different in the cavity of the injection mould from the capillary flow of a laboratory rheological instrument. An injection moulding slit die rheometer (Rheo-mould was designed with a series of slit and orifice dies. Four pressure sensors were built in the stationary side of the mould, therefore the pressure could be measured at four different places. A changeable slit die insert was designed in the moving side. The shear stress and the shear rate can be calculated from the pressure gradient and from the flow rate of the melt, respectively. Flow curves of low density polyethylene were determined using Bagley, Rabinowitsch and Mooney corrections. The results were compared to the flow curves determined by Göttfert and Haake capillary equipments. It was found that the agreement between the methods is excellent.

  8. Transcription of Small Surface Structures in Injection Moulding - An Experimental Study

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf; Kjær, Erik Michael

    2000-01-01

    The ability to replicate the surface roughness from mold wall to the plastic part in injection moldning has many functional and cosmetic important implications from medical use to designer products. Generally the understanding of surface transcription i.e the the replication of the surface...... structure from the mould to plastic part, also relates to micro injection moulding and moulding of parts with specific micro structures on the surface such as optical parts. The present study concerns transcription of surface roughness as a function of process parameters. The study is carried out...

  9. Isolation and identification mould micoflora inhabiting plant leaf litter from Mount Lawu, Surakarta, Central Java

    Directory of Open Access Journals (Sweden)

    MUHAMMAD ILYAS

    2007-04-01

    Full Text Available A study on isolation and identification mould inhabiting plant leaf litter had been conducted. The objective of the study was to isolate and identify mould inhabiting plant leaf litter from Mount Lawu, Surakarta, Central Java. The mould isolation was based on washing and filtering with membrane isolation method. The result showed that 39 moulds generas with 55 species varians, one group identified in class level, and three groups of unidentified mould isolates had been isolated. Taxas distributions showed that there were endophyte and phytopatogen mould isolates had been isolated such as Fusarium, Pestalotiopsis, Phoma, and Coelomycetes. However, typical soil taxa and common saprobic fungi such as Aspergillus, Cunninghamella, Mucor, Paecilomyces, Penicillium, Rhizopus, and Trichoderma remain dominated the resulted isolates.

  10. Flow Dynamics of green sand in the DISAMATIC moulding process using Discrete element method (DEM)

    International Nuclear Information System (INIS)

    Hovad, E; Walther, J H; Thorborg, J; Hattel, J H; Larsen, P

    2015-01-01

    The DISAMATIC casting process production of sand moulds is simulated with DEM (discrete element method). The main purpose is to simulate the dynamics of the flow of green sand, during the production of the sand mould with DEM. The sand shot is simulated, which is the first stage of the DISAMATIC casting process. Depending on the actual casting geometry the mould can be geometrically quite complex involving e.g. shadowing effects and this is directly reflected in the sand flow during the moulding process. In the present work a mould chamber with “ribs” at the walls is chosen as a baseline geometry to emulate some of these important conditions found in the real moulding process. The sand flow is simulated with the DEM and compared with corresponding video footages from the interior of the chamber during the moulding process. The effect of the rolling resistance and the static friction coefficient is analysed and discussed in relation to the experimental findings. (paper)

  11. Double-curved precast concrete elements : Research into technical viability of the flexible mould method

    NARCIS (Netherlands)

    Schipper, H.R.

    2015-01-01

    The production of precast, concrete elements with complex, double-curved geometry is expensive due to the high costcosts of the necessary moulds and the limited possibilities for mould reuse. Currently, CNC-milled foam moulds are the solution applied mostly in projects, offering good aesthetic

  12. Grains colonised by moulds: fungal identification and headspace analysis of produced volatile metabolites

    Directory of Open Access Journals (Sweden)

    Maria Paola Tampieri

    2010-01-01

    Full Text Available The aim of this work was to verify if the headspace analysis of fungal volatile compounds produced by some species of Fusarium can be used as a marker of mould presence on maize. Eight samples of maize (four yellow maize from North Italy and four white maize from Hungary, naturally contaminated by Fusarium and positive for the presence of fumonisins, were analyzed to detect moisture content, Aw, volatile metabolites and an enumeration of viable moulds was performed by means of a colony count technique. Headspace samples were analysed using a gas-chromatograph equipped with a capillary column TR-WAX to detect volatile metabolites of moulds. Furthermore macro and microscopic examination of the colonies was performed in order to distinguish, according to their morphology, the genera of the prevalent present moulds. Prevalent mould of eight samples was Fusarium, but other fungi, like Aspergillus, Penicillum and Mucoraceae, were observed. The metabolites produced by F.graminearum and F. moniliforme were Isobutyl-acetate, 3-Methyl-1-butanol and, only at 8 days, 3-Octanone. The incubation time can affect off flavour production in consequence of the presence of other moulds. Further studies on maize samples under different conditions are needed in order to establish the presence of moulds using the count technique and through the identification of volatile compounds.

  13. Influence of Binding Rates on Strength Properties of Moulding Sands with the GEOPOL Binder

    Directory of Open Access Journals (Sweden)

    Holtzer M.

    2014-03-01

    Full Text Available The results of investigations of moulding sands with an inorganic binder called GEOPOL, developed by the SAND TEAM Company are presented in the paper. Hardeners of various hardening rates are used for moulding sands with this binder. The main aim of investigations was determination of the influence of the hardening rate of moulding sands with the GEOPOL binder on technological properties of these sands (bending strength, tensile strength, permeability and grindability. In addition, the final strength of moulding sands of the selected compositions was determined by two methods: by splitting strength and shear strength measurements. No essential influence of the hardening rate on such parameters as: permeability, grindability and final strength was found. However, the sand in which the slowest hardener (SA 72 were used, after 1 hour of holding, had the tensile and bending strength practically zero. Thus, the time needed for taking to pieces the mould made of such moulding sand will be 1.5 - 2 hours.

  14. Report on best practice for improved μ-IM injection moulding simulation

    DEFF Research Database (Denmark)

    Tosello, Guido; Costa, Franco; Hansen, Hans Nørgaard

    2010-01-01

    Data analysis and simulations on micro-moulding experiments have been conducted. Micro moulding simulations have been executed taking into account actual processing conditions implementation in the software. Numerous aspects of the simulation set-up have been considered in order to improve the si...

  15. Micro Injection Moulding High Accuracy Three-Dimensional Simulations and Process Control

    DEFF Research Database (Denmark)

    Tosello, Guido; Costa, F.S.; Hansen, Hans Nørgaard

    2011-01-01

    Data analysis and simulations of micro‐moulding experiments have been conducted. Micro moulding simulations have been executed by implementing in the software the actual processing conditions. Various aspects of the simulation set‐up have been considered in order to improve the simulation accurac...

  16. Replication of micro structured surface by injection moulding of PEEK

    DEFF Research Database (Denmark)

    Zhang, Yang; Hansen, Hans Nørgaard; Sørensen, Søren

    A micro-structured Ni insert was investigated for PEEK injection moulding. The micro features are circular holes 4 μm in diameter and 2 μm deep, with a 2 μm edge-to-edge distance. 6000 moulding cycles was operated. Half of the insert was coated by 200nm CrN. PEEK parts produced by the coated side...

  17. The presence of undesirable mould species on the surface of dry sausages

    Directory of Open Access Journals (Sweden)

    Vesković-Moračanin Slavica M.

    2008-01-01

    Full Text Available Transition from manufacture to the industrial way of meat production and processing, as well as contemporary concept of food quality and safety, have led to the application of starter cultures. Their application leads towards the streamlining of the production process in the desired direction, quality improvement and its harmonization, and thereby to its standardization. Application of moulds in the meat industry is based on positive effects of their proteolytic and lipolytic egzoenzymes which, as a consequence, leads to the creation of characteristic sensory properties ('flavor' of fermented products. Penicillium nalgiovense is a typical representative of moulds used in the production of fermented sausages-salamis from our region. Samples of 'zimska salama' (dry sausage, produced with Penicillium nalgiovense, were evaluated as hygienically unacceptable. Their sensory properties changed due to contamination of this mould during the ripening process. Micological analysis discovered the presence of Penicillium aurantiogriseum, which is a frequent mould contaminant in the meat industry. At the same time, thin layer chromatography revealed no possibility of metabolic activity of this mould in the creation of mycotoxins. However, the presence of this mould on the surface of 'zimska salama' is considered as undesirable due to formation of 'off flavor' in products. Such product is considered as hygienically unacceptable and cannot be used for the human consumption.

  18. Additive manufacturing for the production of inserts for micro injection moulding

    DEFF Research Database (Denmark)

    Mischkot, Michael; Hansen, Hans Nørgaard; Pedersen, David Bue

    2015-01-01

    The production of inserts for micro injection moulding using additive manufacturing technology has the potential to greatly improve the efficiency of pilot production and reduce overall time to market. In this work, Digital Light Processing (DLP) was used to produce micro injection moulding inserts...

  19. [Effects of construct accessibility and self-schema on person memory].

    Science.gov (United States)

    Kitamura, H

    1991-10-01

    The present study investigated the relationship among construct accessibility, self-schema and person memory. Three hundred and thirty-four subjects received 40 behavioral descriptions of a stimulus person, consisting of eight specific behaviors on each of five trait-dimensions. Subjects also rated personality traits of their acquaintances and themselves on nine-point bipolar scales and ranked the importance of the five trait-dimensions. Weights, which subjects assigned to each of the five dimensions, were calculated as indices of construct accessibility. Self-schema scores of each subject were also calculated based on his/her ratings. Multiple regression analyses indicated that the dimensional weights and self-schema scores were positively correlated with the recall performance of the descriptions of the stimulus person. The schematics recalled significantly more descriptions than the aschematics, whether their self-schema was positive or negative. Subjects who had positive self-schema showed higher construct accessibility than the aschematics. It was argued that the relationship between construct accessibility and self-schema might be affected by motivational factors such as self-esteem.

  20. Free-form nanostructured tools for plastic injection moulding

    DEFF Research Database (Denmark)

    Kafka, Jan; Sonne, Mads Rostgaard; Lam, Yee Cheong

    realized and successfully transferred to plastic parts during injection moulding.As an example, we present theory and results regarding the imprint of pillar nanostructures on a semi-spherical mold surface, followed by injection molding of the same. The deformation of the flexible stamp is characterized...... by measurement of inter-pillar distance on various points on the sphere, and compared to predictions provided by a geometrical model. Moulded plastic parts show good replication of the pillar structure.There are various practical advantages to the new process: the application of the coating is possible on both...

  1. Heater Choice, Dampness and Mould Growth in 26 New Zealand Homes: A Study of Propensity for Mould Growth Using Encapsulated Fungal Spores

    Directory of Open Access Journals (Sweden)

    Mikael Boulic

    2015-02-01

    Full Text Available The relationship between the use of unflued gas heaters (UGH, N = 14 and heat pump heaters (HP, N = 12 located in the living rooms, and mould growth on the living room and bedroom walls, of 26 New Zealand (NZ occupied homes was investigated during winter. Two methods were employed to evaluate the potential of mould growth on walls: (i measurement of daily hyphal growth rate using a fungal detector (encapsulated fungal spores; and (ii estimation of fungal contamination based on a four level scale visual inspection. The average wall psychrometric conditions were significantly different between the two heater type groups, in both the living rooms and the bedrooms with the UGH user homes being colder and damper than HP user homes. The UGHs were found to be a significant additional source of moisture in the living rooms which dramatically increased the capacity for fungi to grow on wall surfaces. The average daily hyphal growth rates were 4 and 16 times higher in the living rooms and in the bedrooms of the UGH user homes, respectively. Results from both mould detection methods gave good agreement, showing that the use of a fungal detector was an efficient method to predict the potential of mould growth on the inside of the external walls in NZ homes.

  2. The estimation of harmfulness for environment of moulding sand with biopolymer binder based on polylactide

    Directory of Open Access Journals (Sweden)

    K. Major-Gabryś

    2011-01-01

    Full Text Available The article takes into consideration technological and ecological aspects of IV generation moulding sands. Investigations concerning anapplication of biopolymer materials as binders for moulding sands are presented in the paper. These investigations are the continuation ofexaminations related to applications of various biopolymers as binding agents and to the properties of the moulding sands with biopolymerbinders. In the paper there are the researches concerning analyzing gases emitted from moulding sands during heating.

  3. Extent of moisture and mould damage in structures of public buildings

    Directory of Open Access Journals (Sweden)

    Petri J. Annila

    2017-06-01

    Full Text Available The study concentrated on the extent of moisture and mould damage in different structures in 25 public buildings in Finland. Users of all the buildings had health symptoms suspected to be the result of moisture and mould damage, which is why moisture performance assessments had been performed. The assessment reports on each building were available as research material. The reports indicated that the examined buildings suffered from multiple moisture and mould problems in several different structures. On average, however, a relatively small proportion of the total number of structures had suffered damage. On the basis of the research material, damage was most extensive in walls in soil contact (16.3% and base floor structures (12.5%. The lowest damage rates were found in partition walls (2.4%, external walls (2.6% and intermediate floors (2.5%. The results of the study underline the importance of thorough moisture performance assessments to ensure that all point-sized moisture and mould damage is detected.

  4. Advances in precision machining and moulding technology bring design opportunities.

    Science.gov (United States)

    Glendening, Paul

    2008-09-01

    Machining of materials for medical applications has moved to a new level of precision. In parallel with this, moulding technology has improved through the increased use of sensors in moulds, enhanced design simulation and processes such as micromoulding. This article examines the opportunities offered by these developments and includes examples of mass produced parts that demonstrate the new capabilities useful to product designers.

  5. Potentially pathogenic, pathogenic, and allergenic moulds in the urban soils

    Directory of Open Access Journals (Sweden)

    Đukić Dragutin A.

    2011-01-01

    Full Text Available The dynamics of soil mould populations that can compromise the human immune system was evaluated in experimental plots located at different distances (100, 300, 500, 700 and 900 m from the main source of pollution - the Podgorica Aluminum Plant. Soil samples were collected in July and October 2008 from three different plot zones at a depth of 0-10 cm. The count of potentially pathogenic, keratinolytic and allergenic (melaninogenic moulds was assessed, which can significantly contribute to both diagnosis and prophylaxis. The count of medically important moulds was higher in the urban soil than in the unpolluted (control soil. Their count decreased with increasing distance from the main pollution source (PAP. Their abundance in the soil was considerably higher in autumn than in spring.

  6. Thermal Conductivity of Moulding Sand with Chemical Binders, Attempts of its Increasing

    Directory of Open Access Journals (Sweden)

    Zych J.

    2015-04-01

    Full Text Available The investigation results of the thermal conductivity of the selected group of moulding sands with chemical binders, mainly organic, are presented in the hereby paper. Studies encompassed also moulding sands into which additions improving the thermal conductivity were introduced. Two testing methods were applied, i.e. investigations at a steady and unsteady temperature zone. For investigations at a steady temperature zone the new original experimental stand was designed and built, adapted also for testing moulding sands with binders undergoing destruction at relatively low temperatures.

  7. Teflon injections in post-prostatectomy incontinence

    DEFF Research Database (Denmark)

    Osther, P J; Røhl, H F

    1988-01-01

    Twenty-five males with post-prostatectomy incontinence due to sphincter damage underwent transperineal or transurethral Teflon injections. The results were classified into three grades: good, moderate, and poor. Good or moderate results were obtained in 24%. No major immediate complications...... or longterm side-effects were observed. This intervention is associated with a minimum of discomfort for the patient and hospitalization can be limited to 48-72 hours. The results are not so good as those obtained in female incontinence, and the procedure cannot be recommended as first choice treatment...... in patients with post-prostatectomy incontinence, but because of the simplicity of the procedure, it is considered to be a valuable alternative in patients not suitable for prosthetic surgery....

  8. Construction of MDS self-dual codes from orthogonal matrices

    OpenAIRE

    Shi, Minjia; Sok, Lin; Solé, Patrick

    2016-01-01

    In this paper, we give algorithms and methods of construction of self-dual codes over finite fields using orthogonal matrices. Randomization in the orthogonal group, and code extension are the main tools. Some optimal, almost MDS, and MDS self-dual codes over both small and large prime fields are constructed.

  9. An Experimental Investigation to Facilitate an Improvement in the Design of an Electromagnetic Continuous Casting Mould

    Directory of Open Access Journals (Sweden)

    Lintao Zhang

    2016-04-01

    Full Text Available An electromagnetic continuous casting mould designed is proposed with a non-uniform slit distribution structure. This design has aimed to reduce the number of slits so that the mould’s strength is enhanced, whilst maintaining a similar metallurgy effect. In this paper, the metallurgy effect for the designed mould is investigated through the magnetic field distribution along the casting direction, the uniformity feature in the vicinity of the meniscus region, the temperature variation of the molten alloy pool and the mould wall. The results show that the designed mould achieved a similar effect as compared to the original mould; however, the configuration is simplified. This research highlights the topic of mould structure optimization, which would enable the Electromagnetic continuous casting (EMCC technique to be utilized with greater ease by industry.

  10. Effect of hardening methods of moulding sands with water glass on structure of bonding bridges

    Directory of Open Access Journals (Sweden)

    M. Stachowicz

    2010-07-01

    Full Text Available Research on influence of hardening methods on structure of bonding bridges in moulding sands with sodium water glass is presented.Moulding sands with addition of 2.5 % of binder with molar module 2.0 were hardened with CO2 and dried in traditional way or hardenedwith microwaves. It was proved that the hardening method affects structure of bonding bridges, correlating with properties of the hardened moulding sands. It was found that strength of the moulding sands hardened with microwaves for 4 min is very close to that measured after traditional drying at 110 °C for 120 min. So, application of microwave hardening ensures significant shortening of the process time to the value comparable with CO2 hardening but guaranteeing over 10-fold increase of mechanical properties. Analysis of SEM images of hardened moulding sands permitted explaining differences in quality parameters of moulding sands by connecting them with structure of the created bonding bridges.

  11. Replication quality assessment and uncertainty evaluation of a polymer precision injection moulded component

    DEFF Research Database (Denmark)

    Baruffi, Federico; Calaon, Matteo; Tosello, Guido

    2017-01-01

    Precision injection moulding holds a central role in manufacturing as only replication process currently capable of accurately producing complex shaped polymer parts integrating micrometric features on a mass scale production. In this scenario, a study on the replication quality of a polymer...... injection moulded precision component for telecommunication applications is presented. The effects of the process parameters on the component dimensional variation have been investigated using a statistical approach. Replication fidelity of produced parts has been assessed using a focus variation microscope...... with sub-micrometric resolution. Measurement uncertainty has then been evaluated, according to the GUM considering contributions from different process settings combinations and mould geometries. The analysis showed that the injection moulding manufacturing process and the utilized measurement chain...

  12. Comparative evaluation of the effect of silicone and teflon in prevention of epidural fibrosis after laminectomy in rat

    Directory of Open Access Journals (Sweden)

    Sheikh Rezaei A

    2001-08-01

    Full Text Available There are many studies about epidural fibrosis after surgical manipulation of the spine. We have studied formation of the post laminectomy epidural fibrosis after application of two materials (Silicone and Teflon in this report. This expriment is on two groups of rats. Two separated laminectomies were done in each rat, one serving as control while in the other laminectomy spaces Silicone was used in group A and Teflon in group B. Laminectomy spaces were evaluated with gross dissection and histologic studies after 6 weeks. Silicone decreased intermuscular scar, deep scar, dural adhesion and collagen fiber density in epidural space. Teflon decreased dural adhesion and collagen fiber density but did not decrease intermuscular and deep scar formation in epidural space.

  13. Two underestimated threats in food transportation: mould and acceleration.

    Science.gov (United States)

    Janssen, S; Pankoke, I; Klus, K; Schmitt, K; Stephan, U; Wöllenstein, J

    2014-06-13

    Two important parameters are often neglected in the monitoring of perishable goods during transport: mould contamination of fresh food and the influence of acceleration or vibration on the quality of a product. We assert the claim that it is necessary to focus research on these two topics in the context of intelligent logistics in this opinion paper. Further, the technical possibilities for future measurement systems are discussed. By measuring taste deviations, we verified the effect on the quality of beer at different vibration frequencies. The practical importance is shown by examining transport routes and market shares. The general feasibility of a mobile mould detection system is established by examining the measurement resolution of semiconductor sensors for mould-related gases. Furthermore, as an alternative solution, we present a concept for a miniaturized and automated culture-medium-based system. Although there is a lack of related research to date, new efforts can make a vital contribution to the reduction of losses in the logistic chains for several products.

  14. Qualification of Magnesium/Teflon/Viton Pyrotechnic Composition Used in Rocket Motors Ignition System

    Directory of Open Access Journals (Sweden)

    Luciana de Barros

    2016-04-01

    Full Text Available The application of fluoropolymers in high-energy-release pyrotechnic compositions is common in the space and defense areas. Pyrotechnic compositions of magnesium/Teflon/Viton are widely used in military flares and pyrogen igniters for igniting the solid propellant of a rocket motor. Pyrotechnic components are considered high-risk products as they may cause catastrophic accidents if initiated or ignited inadvertently. To reduce the hazards involved in the handling, storage and transportation of these devices, the magnesium/Teflon/Viton composition was subjected to various sensitivity tests, DSC and had its stability and compatibility tested with other materials. This composition obtained satisfactory results in all the tests, which qualifies it as safe for production, handling, use, storage and transportation.

  15. Placement suitability criteria of composite tape for mould surface in automated tape placement

    Directory of Open Access Journals (Sweden)

    Zhang Peng

    2015-10-01

    Full Text Available Automated tape placement is an important automated process used for fabrication of large composite structures in aeronautical industry. The carbon fiber composite parts realized with this process tend to replace the aluminum parts produced by high-speed machining. It is difficult to determine the appropriate width of the composite tape in automated tape placement. Wrinkling will appear in the tape if it does not suit for the mould surface. Thus, this paper deals with establishing placement suitability criteria of the composite tape for the mould surface. With the assumptions for ideal mapping and by applying some principles and theorems of differential geometry, the centerline trajectory of the composite tape is identified to follow the geodesic. The placement suitability of the composite tape is examined on three different types of non-developable mould surfaces and four criteria are derived. The developed criteria have been used to test the deposition process over several mould surfaces and the appropriate width for each mould surface is obtained by referring to these criteria.

  16. Evaluation of the viscoelastic behaviour and glass/mould interface friction coefficient in the wafer based precision glass moulding

    DEFF Research Database (Denmark)

    Sarhadi, Ali; Hattel, Jesper Henri; Hansen, Hans Nørgaard

    2014-01-01

    -placements, internal diameter and thickness of the rings are measured during the tests. Viscoelastic andstructural relaxation behaviour of the glass are implemented into the ABAQUS FEM software through aFORTRAN material subroutine (UMAT) and the FE model is validated with a sandwich seal test. Then, byFE simulation...... of the ring compression test and comparison of the experimental creep with the simulatedone in an iterative procedure, viscoelastic parameters of the glass material are characterized. Finally,interfacial glass/mould friction coefficients at different temperatures are determined through FEM basedfriction...... curves combined with experimental data points. The obtained viscoelastic parameters and inter-facial friction coefficients can later be employed for prediction of the final shape/size as well as the stressdistribution in the glass wafer during a real wafer based precision glass moulding process. © 2014...

  17. Process Optimization for Injection Moulding of Passive Microwave Components

    DEFF Research Database (Denmark)

    Scholz, Steffen G.; Mueller, Tobias; Santos Machado, Leonardo

    2016-01-01

    The demand for micro components has increased during the last decade following the overall trend towards miniaturization. Injection moulding is the favoured technique for the mass manufacturing of micro components or larger parts with micro-structured areas due to its ability to cost effectively ...... algorithm for modelling, the influence of different moulding parameters on the final part quality was assessed. Firstly a process model and secondly a quality model has been calculated. The results shows that part quality can be controlled by monitoring characteristic numbers....

  18. [Invasive mould disease in haematological patients].

    Science.gov (United States)

    Ruiz-Camps, Isabel; Jarque, Isidro

    2014-01-01

    Invasive mould infections (IMI) are a persistent problem with high morbidity and mortality rates among patients receiving chemotherapy for hematological malignancies and hematopoietic stem cell transplant recipients. Management of IMI in this setting has become increasingly complex with the advent of new antifungal agents and diagnostic tests, which have resulted in different therapeutic strategies (prophylactic, empirical, pre-emptive, and directed). A proper assessment of the individual risk for IMI appears to be critical in order to use the best prophylactic and therapeutic approach and increase the survival rates. Among the available antifungal drugs, the most frequently used in the hematologic patient are fluconazole, mould-active azoles (itraconazole, posaconazole and voriconazole), candins (anidulafungin, caspofungin and micafungin), and lipid formulations of amphotericin B. Specific recommendations for their use, and criteria for selecting the antifungal agents are discussed in this paper. Copyright © 2014. Published by Elsevier Espana.

  19. Flow Dynamics of green sand in the DISAMATIC moulding process using Discrete element method (DEM)

    DEFF Research Database (Denmark)

    Hovad, Emil; Larsen, P.; Walther, Jens Honore

    2015-01-01

    casting process. Depending on the actual casting geometry the mould can be geometrically quite complex involving e.g. shadowing effects and this is directly reflected in the sand flow during the moulding process. In the present work a mould chamber with “ribs” at the walls is chosen as a baseline geometry...

  20. Shear Strength of Remoulding Clay Samples Using Different Methods of Moulding

    Science.gov (United States)

    Norhaliza, W.; Ismail, B.; Azhar, A. T. S.; Nurul, N. J.

    2016-07-01

    Shear strength for clay soil was required to determine the soil stability. Clay was known as a soil with complex natural formations and very difficult to obtain undisturbed samples at the site. The aim of this paper was to determine the unconfined shear strength of remoulded clay on different methods in moulding samples which were proctor compaction, hand operated soil compacter and miniature mould methods. All the samples were remoulded with the same optimum moisture content (OMC) and density that were 18% and 1880 kg/m3 respectively. The unconfined shear strength results of remoulding clay soils for proctor compaction method was 289.56kPa with the strain 4.8%, hand operated method was 261.66kPa with the strain 4.4% and miniature mould method was 247.52kPa with the strain 3.9%. Based on the proctor compaction method, the reduction percentage of unconfined shear strength of remoulded clay soil of hand operated method was 9.66%, and for miniature mould method was 14.52%. Thus, because there was no significant difference of reduction percentage of unconfined shear strength between three different methods, so it can be concluded that remoulding clay by hand operated method and miniature mould method were accepted and suggested to perform remoulding clay samples by other future researcher. However for comparison, the hand operated method was more suitable to form remoulded clay sample in term of easiness, saving time and less energy for unconfined shear strength determination purposes.

  1. Process Factors Influence on Cavity Pressure Behavior in Microinjection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C. A.; Dimov, S. S.; Scholz, S.

    2011-01-01

    about the filling behavior of different polymer melts. In this paper, a pressure sensor mounted inside a tool cavity was employed to analyse maximum cavity pressure, pressure increase rate during filling and pressure work. The influence of four mu IM parameters, melt temperature, mould temperature......Process monitoring of microinjection moulding (mu IM) is of crucial importance when analysing the effect of different parameter settings on the process and then in assessing its quality. Quality factors related to cavity pressure can provide valuable information about the process dynamics and also......, injection speed, and packing pressure on these three pressure-related process parameters was investigated. A design of experiment study was conducted by moulding a test part, a microfluidic component, in three different polymer materials, PP, ABS, and PC. The results show a similar process behavior for all...

  2. Effects of moulding and environmental conditions on the mechanical and surface properties of injection moulded santoprene rubber

    DEFF Research Database (Denmark)

    Islam, Aminul; Ruby, Tobias M.; Jessen, Rikke L.

    the electronics inside from environmental hazards. The sealing ring is injection moulded in Santoprene-a thermoplastic vulcanizate consisting of Polypropelene and highly vulcanized EPDM rubber. The scope of the project was therefore to investigate the properties of Santoprene and make an immediate evaluation...

  3. Moulding Sands with New InorganicBinders - Ecology Assessment in the Aspect of Work Environment

    Directory of Open Access Journals (Sweden)

    I. Szanda

    2012-09-01

    Full Text Available The development of economy and industry introducing new technologies and materials often means the increased threat of occurrenceof factors harmful to humans and environment. Workers employed in foundries as mould pourers are the group of high professional risk.Foundry moulding sands when poured with liquid metal are a source of the emission of harmful, toxic and carcinogenic (benzene,PAHs compounds.The paper presents the results of studies on the concentration of chemical compounds emitted in the process of casting aluminiumalloy and brass using moulding sands with the new inorganic binders. The specific values of the exposure indices were compared with thelimit values. This enabled an assessment of the impact of moulding sands on work environment. The obtained results were compared withthe values of contaminants emitted when pouring foundry moulds made from furan sands and bentonite sands with an addition of coaldust.Studies were carried out under the project POIG.01.01.02-00-015/09 "Advanced materials and technologies."

  4. Calculated energy dependence of CaSO4:Dy TL phosphor and phosphor embedded Teflon for X and gamma rays

    International Nuclear Information System (INIS)

    Chang, J.-K.; Nam, Y.-M.; Kim, J.-L.; Chang, S.-Y.; Kim, B.-H.

    2001-01-01

    The energy dependence of a CaSO 4 :Dy TL phosphor for 21 monoenergetic photons of energy ranging from 0.01 to 3 MeV was calculated by using MCNP4A code. The calculation results show good agreement with those of other authors within ± 5% relative error. Calculations and experiments are also performed to determine the energy dependence of CaSO 4 : Dy phosphor with Dy concentrations from 0.01 to 1.5 mol %, and with the compositions of TL-Teflon from 10 to 90 wt %. The calculated energy responses show good agreement with the experiment results within ± 20% relative error except for a concentration lower than 0.1 mol % Dy and the low energy regions of M30 (Eave.=20 keV) and M60 (Eave.=34 keV). For the TL-Teflon mixture, the energy dependence shows an decreasing trend with the increase of Teflon concentration in MCNP calculation but shows no dependence for TL-Teflon mixture proportions in experiment. These differences are due to the non-homogeneous distribution of Dy concentration and the effect of large grain size in the phosphors. The energy dependence of the 30 wt/o CaSO 4 (0.1 mol%;Dy) and 70 wt/o Teflon that is placed behind the filters of plastic, aluminum, copper, tin and lead with a thickness from 0.1 to 2 mm were calculated, respectively

  5. Manuscript title: antifungal proteins from moulds: analytical tools and potential application to dry-ripened foods.

    Science.gov (United States)

    Delgado, Josué; Owens, Rebecca A; Doyle, Sean; Asensio, Miguel A; Núñez, Félix

    2016-08-01

    Moulds growing on the surface of dry-ripened foods contribute to their sensory qualities, but some of them are able to produce mycotoxins that pose a hazard to consumers. Small cysteine-rich antifungal proteins (AFPs) from moulds are highly stable to pH and proteolysis and exhibit a broad inhibition spectrum against filamentous fungi, providing new chances to control hazardous moulds in fermented foods. The analytical tools for characterizing the cellular targets and affected pathways are reviewed. Strategies currently employed to study these mechanisms of action include 'omics' approaches that have come to the forefront in recent years, developing in tandem with genome sequencing of relevant organisms. These techniques contribute to a better understanding of the response of moulds against AFPs, allowing the design of complementary strategies to maximize or overcome the limitations of using AFPs on foods. AFPs alter chitin biosynthesis, and some fungi react inducing cell wall integrity (CWI) pathway. However, moulds able to increase chitin content at the cell wall by increasing proteins in either CWI or calmodulin-calcineurin signalling pathways will resist AFPs. Similarly, AFPs increase the intracellular levels of reactive oxygen species (ROS), and moulds increasing G-protein complex β subunit CpcB and/or enzymes to efficiently produce glutathione may evade apoptosis. Unknown aspects that need to be addressed include the interaction with mycotoxin production by less sensitive toxigenic moulds. However, significant steps have been taken to encourage the use of AFPs in intermediate-moisture foods, particularly for mould-ripened cheese and meat products.

  6. Female urinary stress incontinence treated with Teflon injections

    DEFF Research Database (Denmark)

    Osther, P J; Røhl, H

    1987-01-01

    Twenty-six women with urinary stress incontinence underwent transperineal or transurethral Teflon injections. The results were classified into three grades (good, moderate, and poor). Good or moderate results were obtained in 50%. No major immediate complications or long-term side-effects were...... observed. This intervention is associated with a minimum of discomfort for the patient and hospitalization can be limited to 48-72 h. The procedure can be carried out with good effect on women previously classically operated on without success and it does not prevent subsequent surgical intervention...

  7. Microstructure, SDAS and Mechanical Properties of A356 alloy Castings Made in Sand and Granulated Blast Furnace Slag Moulds

    Directory of Open Access Journals (Sweden)

    Jinugu B. R.

    2017-03-01

    Full Text Available Investigations were carried out to ensure the granulated blast furnace (GBF slag as an alternative mould material in foundry industry by assessing the cast products structure property correlations. Sodium silicate-CO2 process was adopted for preparing the moulds. Three types of moulds were made with slag, silica sand individually and combination of these two with 10% sodium silicate and 20 seconds CO2 gassing time. A356 alloy castings were performed on these newly developed slag moulds. The cast products were investigated for its metallography and mechanical properties. Results reveal that cast products with good surface finish and without any defects were produced. Faster heat transfers in slag moulds enabled the cast products with fine and refined grain structured; and also, lower Secondary Dendrite Arm Spacing (SDAS values were observed than sand mould. Slag mould casting shows improved mechanical properties like hardness, compression, tensile and impact strength compared to sand mould castings. Two types of tensile fracture modes, namely cleavage pattern with flat surfaces representing Al−Si eutectic zone and the areas of broken Fe-rich intermetallic compounds which appear as flower-like morphology was observed in sand mould castings. In contrast, GBF slag mould castings exhibit majority in dimple fracture morphology with traces of cleavage fracture. Charpy impact fractured surfaces of sand mould castings shows both transgranular and intergranular fracture modes. Only intergranular fracture mode was noticed in both GBF slag and mixed mould castings.

  8. The Transculturing Self II. Constructing Identity through Identification

    Science.gov (United States)

    Monceri, Flavia

    2009-01-01

    In this article, I try to further develop my notion of the "transculturing self." Firstly, I discuss Nietzsche's positions on "self" and "subject," arguing for the idea that "there is no self." Hence, I try to show that "identity" is the outcome of a (co-)construction originating in the circumstance that each individual needs to meet external…

  9. Potential of the application of the modified polysaccharides water solutions as binders of moulding sands

    Directory of Open Access Journals (Sweden)

    K. Kaczmarska

    2015-10-01

    Full Text Available The results of preliminary tests of selected properties of the moulding sands with the binder in the form of a 5 % water solution of the sodium salt of carboxymethyl starch (with a degree of substitution (DS of 0,2 and 0,87 arepresented in this study. The moulding sand properties such as permeability, abrasion resistance, tensile and bendingstrength - after curing - are shown in series of tests. The cure process was conducted in a field of electromagnetic radiation within the microwave range. The effect of the microwave treatment on the moulding sand was evaporating of water (solvent in a binder and cross-linking of the polymeric binder. As a result the cured moulding sands with particular properties, essential in the context of its application in the mould technology in the foundry industry, were obtained.

  10. Effects of holding pressure and process temperatures on the mechanical properties of moulded metallic parts

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Esteves, N.M.

    2013-01-01

    Metal injection moulding is gaining more and more importance over the time and needs more research to be done to understand the sensitivity of process to different process parameters. The current paper makes an attempt to better understand the effects of holding pressure and process temperatures...... on the moulded metallic parts. Stainless steel 316L is used in the investigation to produce the specimen by metal injection moulding (MIM) and multiple analyses were carried out on samples produced with different combinations of holding pressure, mould temperature and melt temperature. Finally, the parts were...... characterized to investigate mechanical properties like density, ultimate tensile strength, shrinkage etc. The results are discussed in the paper. The main conclusion from this study is unlike plastic moulding, the tensile properties of MIM parts doesn’t vary based on the flow direction of the melt, and tensile...

  11. Development of injection moulded, ultrasonically welded immiscible phase filtration devices

    DEFF Research Database (Denmark)

    Kistrup, Kasper

    for ultrasonic welding, suitable for microfluidic systems. A methodology has been established where energy directors can be quickly added to existing mould inserts, using laser micromachining. The produced device was performance tested by isolating methicillin-resistant Staphylococcus aureus from bovine whole....... The device appliesmagnetic bead-based solid-phase extraction for nucleic acid extraction from biological samples, using the immiscible phase filtration (IPF) approach. Device development has employed injection moulding for part fabrication and ultrasonic welding for bonding. Rapid prototyping...

  12. Characterization and analysis of weld lines on micro-injection moulded parts using atomic force microscopy (AFM)

    DEFF Research Database (Denmark)

    Tosello, Guido; Gava, Alberto; Hansen, Hans Nørgaard

    2009-01-01

    In recent years plastic moulding techniques, such as injection moulding, have been developed to fulfil the needs of micro-components fabrication. Micro-injection moulding (SLIM) is the process which enables the mass production of polymer micro-systems such as micro-mechanical parts, micro...... the two original flows will generate and a weld line is formed on the surface of the micro-moulded part. This phenomenon has to be avoided or at least reduced, since in the weld line area the mechanical properties are poorer than in the bulk part, creating strength problems on the final part. Although...... injection moulding parameters on the weld lines' dimensions is presented, using an atomic force microscope (AFM). Depth and width of weld lines were chosen as parameters to be optimized....

  13. Effects of mould on electrochemical migration behaviour of immersion silver finished printed circuit board.

    Science.gov (United States)

    Yi, Pan; Xiao, Kui; Dong, Chaofang; Zou, Shiwen; Li, Xiaogang

    2018-02-01

    The role played by mould in the electrochemical migration (ECM) behaviour of an immersion silver finished printed circuit board (PCB-ImAg) under a direct current (DC) bias was investigated. An interesting phenomenon is found whereby mould, especially Aspergillus niger, can preferentially grow well on PCB-ImAg under electrical bias and then bridge integrated circuits and form a migration path. The cooperation of the mould and DC bias aggravates the ECM process occurring on PCB-ImAg. When the bias voltage is below 15V, ECM almost does not occur for Ag coating. Mechanisms that explain the ECM processes of PCB-ImAg in the presence of mould and DC bias are proposed. Copyright © 2017. Published by Elsevier B.V.

  14. Self-care among Nursing Students: Determining Constructive Concepts of Self-care using Factor Analysis

    OpenAIRE

    Shintani, Keiko

    2006-01-01

    In an effort to clearly defi ne the constructive concepts of self-care among nursing students, in the present study a survey was conducted a survey of 655 individuals, comprised of 260 college nursing students and 395 vocational school nursing students. We found four factors of constructive concepts of self-care among nursing students, which included maintaining diet, coping with stress, maintaining habits and regulating lifestyle patterns, and maintaining interpersonal relationships.

  15. Constructing self-identity: minority students' adaptation trajectories in a Chinese university.

    Science.gov (United States)

    Li, Ling; Wu, Aruna; Li, Xiao Wen; Zhuang, Yuan

    2012-09-01

    Researchers have gone beyond identity status and been putting more and more emphases on the dynamic process of identity development and its contextual embeddedness. Study of individual's adaptation to the multicultural background is a good point of penetration. Because of the differences in regional conditions and cultural traditions, the minority youths who go to university in the mainstream culture would have special experiences and challenges in the development of their self-identities. Semi-structured interview and narrative were used in this research to discover the characteristics of the self-identity constructing processes of Mongolian undergraduates in a Shanghai university context. Their identity constructing process could be divided into three stages: difference-detecting, self-doubting and self-orienting. The main efforts of identity constructing in each stage could all be described as self-exploring and support-seeking. Special contents of internal explorations and sources of support were distinguished at different stages. As relative results, three main types of self-orientation were revealed: goal-oriented, self-isolated and unreserved assimilated. The characteristics of them are quite similar to those of three identity processing styles proposed by Berzonsky, which indicates there are some common elements lying in all self-development processes of adolescences and young adults. Ethnicity and culture could be background and resource or what Côté called identity capital that impacts the special course of self-identity constructing under similar principles. Different attitudes towards and relationships with their own ethnicity and new surroundings separated the three types of students from each other and interacted with the developmental characteristics and tendencies of their ethnicity identifications and self identities. It was found that minority youths' self-identity constructing was based on their needs of self-value and interacted with their

  16. Application of HS-SPME-GC-MS method for the detection of active moulds on historical parchment.

    Science.gov (United States)

    Sawoszczuk, Tomasz; Syguła-Cholewińska, Justyna; Del Hoyo-Meléndez, Julio M

    2017-03-01

    The goal of this work was to analyse the profile of microbial volatile organic compounds (MVOCs) emitted by moulds growing on parchment samples, in search of particular volatiles mentioned in the literature as indicators of active mould growth. First, the growth of various moulds on samples of parchment was assessed. Those species that showed collagenolytic activity were then inoculated on two types of media: samples of parchment placed on media and on media containing amino acids that are elements of the structure of collagen. All samples were prepared inside 20-ml vials (closed system). In the first case, the media did not contain any sources of organic carbon, nitrogen, or sulphur, i.e. parchment was the only nutrient for the moulds. A third type of sample was historical parchment prepared in a Petri dish without a medium and inoculated with a collagenolytically active mould (open system). The MVOCs emitted by moulds were sampled with the headspace-SPME method. Volatiles extracted on DVB/CAR/PDMS fibres were analysed in a gas chromatography-mass spectrometry system. Qualitative and quantitative analyses of chromatograms were carried out in search of indicators of metabolic activity. The results showed that there are three groups of volatiles that can be used for the detection of active forms of moulds on parchment objects. To the best of our knowledge, this is the first work to measure MVOCs emitted by moulds growing on parchment.

  17. Self-Constructs and Anxiety Across Cultures. Research Report. ETS RR-09-12

    Science.gov (United States)

    Lee, Jihyun

    2009-01-01

    This study examined the factorial structure of three related constructs, math self-concept, math self-efficacy, and math anxiety, across 41 countries. One factorial structure was achieved at both between- and within-country levels. Within-country variations of the self-constructs were also noted in relation to math performance: Self-concept showed…

  18. Assessment of the possibility of utilisation of used ceramic moulds originated from the investment casting technology

    Directory of Open Access Journals (Sweden)

    M. Holtzer

    2009-04-01

    Full Text Available Review of wastes generated by investment casting technology and discussion on possibilities of disposal of the largest quantity waste from this technology - used ceramic mould is presented in the paper. Preliminary examinations of disintegration process of used ceramic mould conducted in various testing conditions were performed in the frame of presented research. Applied system of disintegration doesn’twarrant obtained material to be suitable for reuse in production of ceramic moulds. Investigations of the inter-phase boundary: ceramicmould-casting were performed to examine environmental harmfulness of used ceramic moulds. Additionally ecologic assessment of spentmoulds by means of it’s elution in the aspect of qualifying possibilities of it’s disposal were performed. Gained results qualify the waste from ceramic mould to storage in deposits for neutral wastes.

  19. Long-term Effects of Relative Humidity on Properties of Microwave Hardened Moulding Sand with Sodium Silicate

    Directory of Open Access Journals (Sweden)

    Stachowicz M.

    2017-09-01

    Full Text Available Moulding sands containing sodium silicate (water-glass belong to the group of porous mixture with low resistance to increased humidity. Thanks to hydrophilic properties of hardened or even overheated binder, possible is application of effective methods of hydrous reclamation consisting in its secondary hydration. For the same reason (hydrophilia of the binder, moulds and foundry cores made of high-silica moulding sands with sodium silicate are susceptible to the action of components of atmospheric air, including the contained steam. This paper presents results of a research on the effect of (relative humidity on mechanical and technological properties of microwave-hardened moulding mixtures. Specimens of the moulding sand containing 1.5 wt% of sodium water-glass with module 2.5 were subjected, in a laboratory climatic chamber, to long-term action of steam contained in the chamber atmosphere. Concentration of water in atmospheric air was stabilized for 28 days (672 h according to the relative humidity parameter that was ca. 40%, 60% and 80% at constant temperature 20 °C. In three cycles of the examinations, the specimens were taken out from the chamber every 7 days (168 h and their mechanical and technological parameters were determined. It was found on the grounds of laboratory measurements that moulds and cores hardened with microwaves are susceptible to action of atmospheric air and presence of water (as steam intensifies action of the air components on glassy film of sodium silicate. Microwave-hardened moulding sands containing sodium silicate may be stored on a long-term basis in strictly determined atmospheric conditions only, at reduced humidity. In spite of a negative effect of steam contained in the air, the examined moulding mixtures maintain a part of their mechanical and technological properties, so the moulds and foundry cores stored in specified, controlled conditions could be still used in manufacture.

  20. Exploring Imperfect Squeezing Flow Measurements in a Teflon Geometry for Semisolid Foods

    NARCIS (Netherlands)

    Terpstra, M.E.J.; Janssen, A.M.; Linden, van der E.

    2007-01-01

    The method of imperfect lubricated squeezing flow in a Teflon¿ geometry has been explored for the characterization of elongational behavior of custard and mayonnaise. Two Newtonian products, one of low (0.07 Pas) and one of high (18 Pas) shear viscosity, were used as references. Measurements of

  1. Surface wear of TiN coated nickel tool during the injection moulding of polymer micro Fresnel lenses

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Gasparin, Stefania

    2012-01-01

    Limited tool life of nickel mould inserts represents an issue for the mass-production of polymer optics with complex micro three-dimensional geometries by injection moulding. TiN coating was applied to a nickel insert for the injection moulding of polycarbonate micro Fresnel lenses. Surface wear...

  2. Study on the Mould-Resistant Properties of Moso Bamboo Treated with High Pressure and Amylase

    Directory of Open Access Journals (Sweden)

    Xiao-Dong Huang

    2013-11-01

    Full Text Available Starch of moso bamboo mainly exists in the elongated parenchyma cells, and it is difficult for amylase to enter moso bamboo and dissolve the starch. Therefore, the mould resistance capability of moso bamboo’s products cannot meet the need for bamboo to resist fungal decay. In this experiment, moso bamboo blocks were first treated at six levels of pressure and for six different treatment durations. The results showed that reducing sugar content was decreased dramatically from 0.92 mg/L to 0.19 mg/L and the starch content decreased from 1.18% to 0.96% when the pressure was increased from 0 psi to 100 psi. Regression analysis showed that the effects of an individual amylase reaction and individual pressure treatment on the starch or reducing sugar content were significant with a high correlation coefficient. Three traditional types of moso bamboo moulds (Aspergillus niger, Penicillium citrinum, and Trichoderma viride were then used for mould resistance testing. The results revealed that the mould resistance capability of moso bamboo blocks could be greatly improved by the combined effect of enzyme activity and pressure treatment. Mould resistance was enhanced by increasing the pressure or prolonging the treatment time. This research could provide a new method for the protection of bamboo from mould attack.

  3. A retrospective study of the hearing results obtained after stapedotomy by the implantation of two Teflon pistons with a different diameter

    NARCIS (Netherlands)

    Grolman, W.; Tange, R. A.; de Bruijn, A. J.; Hart, A. A.; Schouwenburg, P. F.

    1997-01-01

    This study reports the evaluation of hearing results after implantation of a Teflon piston of a different diameter in cases of otosclerosis requiring stapedotomy. By random selection, a Teflon piston with a shaft diameter of 0.3 mm was inserted in 34 cases and a piston with a shaft diameter of 0.4

  4. On the performance of micro injection moulding process simulations of TPE micro rings

    DEFF Research Database (Denmark)

    Baruffi, Federico; Calaon, Matteo; Tosello, Guido

    , a case study based on the micro injection moulding process of thermoplastic elastomer (TPE) micro rings (volume: 1.5 mm3, mass: 2.2 mg) for sensors application is treated. Injection moulding process simulations using Autodesk Moldflow Insight 2016® were applied with the aim of accomplishing two main...

  5. Moulds and indoor air quality - a man-made problem

    International Nuclear Information System (INIS)

    Langvad, Finn

    2002-01-01

    In the 1970s and 1980s, many house owners in Norway, in order to save energy, insulated their houses by injecting torn-up mineral wool into the entire cavity of the wall. This made the house warmer to live in, but it also created serious condensation problems followed by rot and mould. The extensive use of gypsum boards is also alarming. If gypsum becomes really wet because of a water leakage, it becomes a ticking bomb from the micro-biologic point of view as it provides growth conditions for some of the most dangerous indoor mould fungi known, the Stachybotrys chart arum. The article discusses the danger of this fungus and surveys some of the ways that mould affect human health. There is at present no definition of a normal number of fungus spores per unit volume of air. But the following principles can be taken as guidelines: (1) The concentration of spores indoor must be lower than outdoors. Otherwise extra spores have been generated in the house. (2) The species composition of the air must be approximately the same indoors and outdoors

  6. Assessment Method of Overheating Degree of a Spent Moulding Sand with Organic Binder, After the Casting Process

    Directory of Open Access Journals (Sweden)

    Dańko R.

    2013-06-01

    Full Text Available A proper management of sand grains of moulding sands requires knowing basic properties of the spent matrix after casting knocking out. This information is essential from the point of view of the proper performing the matrix recycling process and preparing moulding sands with reclaimed materials. The most important parameter informing on the matrix quality - in case of moulding sands with organic binders after casting knocking out - is their ignition loss. The methodology of estimating ignition loss of spent moulding sands with organic binder - after casting knocking out - developed in AGH, is presented in the paper. This method applies the simulation MAGMA software, allowing to determine this moulding sand parameter already at the stage of the production preparation.

  7. EFFECT OF TEFLON AND NAFION LOADING AT ANODE IN DIRECT FORMIC ACID FUEL CELL (DFAFC

    Directory of Open Access Journals (Sweden)

    M. S. MASDAR

    2016-08-01

    Full Text Available DFAFC has extensive hydrophilic nature and will cause problems in a limited mass transport in the anode side of electrode. Thus, the microporous layer (MPL of DFAFC needs a different in structure and morphology compared with that of PEMFC and DMFC because it will directly affect the performance. Therefore, in this study, the formulation of anode’s MPL has been investigated by varying the amount of Teflon and Nafion. Different loading of Teflon in MPL and Nafion in catalyst layer, i.e., 0 to 40% in weight, were used to fabricate the anode’s DFAFC. The characteristic of MPLs and anode (MPL with catalyst layer such as surface morphologies and resistivity, i.e., electrical impedance, have been analyzed using field emission scanning electron microscopy (FESEM and contact angle measurements as well as electrochemical impedance spectra (EIS. Meanwhile, the performance of fabricated anode was measured using cyclic voltammetry (CV technique with a half cell of DFAFC. From the result, it was obtained that the optimum content for both Teflon and Nafion on anode’s DFAFC was 20 wt% as shown in a highest electro-activity in electrode. The single cell DFAFC with optimum MEA formulation showed a good performance and hence, it is possible to apply the electricity power for electronic devices.

  8. Influence of the Reclaim Addition on Properties of Moulding Sands with the Geopol Binder

    Directory of Open Access Journals (Sweden)

    Drożyński D.

    2015-03-01

    Full Text Available The investigation results of the influence of the reclaim additions on the properties of moulding sands with the GEOPOL geopolymer binder developed by the SAND TEAM Company were presented. Two brands of hardeners were applied in the tested compositions, the first one was developed by the SAND TEAM Company, marked SA72 and the new hardener offered by the KRATOS Company, marked KR72. The main purpose of investigations was to determine the influence of reclaim fractions and the applied hardener on the basic moulding sands properties, such as: bending and tensile strength, permeability and grindability. The unfavourable influence of the reclaim additions into moulding sands on the tested properties as well as an increased hardening rate, were found. Moulding sands, in which the hardener KR72 of the KRATOS Company was used, were less sensitive to the reclaim additions

  9. Replication of microstructures on three-dimensional geometries by injection moulding of liquid silicone rubber

    DEFF Research Database (Denmark)

    Zhang, Yang; Mischkot, Michael; Hansen, Hans Nørgaard

    2015-01-01

    In this paper, liquid silicon rubber (LSR) parts with micro pillars are studied. The LSR parts were produced by injection moulding and are used as anchoring device for electrode implants inside humans. Micro-structures with specific dimension on implant surfaces can reduce encapsulation...... by the human body, thereby improving implant performance. This paper presents a method of applying micro structure on 3D parts. A Ni-plate with micro holes on the surface was cut into inserts and stuck in a cavity for injection moulding. 1000 injection moulding cycles were performed. Key dimensions...

  10. On the variations of strength of the CO sub 2 -silicate mould. CO sub 2 igata no kyodo henka ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Kenzo; Natori, Yoshikatsu; Suganuma, Sadao (Koei Co., Ltd., Saitama, (Japan) Nippon Chemical Industrial Co., Ltd., Tokyo, (Japan))

    1990-01-25

    Moulds prepared by uniform hardening were stored in normal foundry atmosphere and in the humidity controlled chamber to investigate properties of mould. Then, the relationship between the reaction rate of CO {sub 2} and Na {sub 2} 0 contained in mould binder and mould strength was studied. Followings were found: Turning point between absorption and desorption of mould exsits between 81-83% relative humidity (RH). Under the hith RH of the turning point or more, more the water glass addition, more the absorbed amount. When moulds were stored in the humidity controlled chamber, close relation was found between RH%, desorption or absorption rate and mould strength, that is, higher the desorption rate, higher the strength. Further, the reversible relationship was found between the strength and absorpion or desorption rate. Although any deterioration of strength was not found for moulds stored in the humidity controlled chamber (RH of 44-81%), moulds stored in normal foundry stmosphere lost the strength or deteriorated gradually. 7 refs., 11 figs., 2 tabs.

  11. Plaster: its influence on the behaviour of mould surface in the gluing process

    International Nuclear Information System (INIS)

    Jordao, M.A.P.; Goulart, E.P.; Souza, D.D.D. de; Kiyohara, P.K.

    1989-01-01

    Plaster is an important auxiliary raw material in ceramics, but the industry in Brazil use to give litle importance to its properties. The IPT Ceramic Department initiated studies to upgrade local knowledge on this material. In this paper, the following already studied topics are presented. Characterization of α and β plaster powder, by X-ray diffraction, optical and scanning electron microscopy, specific gravity and surface are (BET). Influence of the plaster/water ratio on the mould characteristics by X-ray diffraction, scanning electron microscopy, porosity and permeability. Behavior of the plaster mould surface against the moulded surface after several aluminum oxide splip castings by scanning electron microscopy [pt

  12. C-stop production by micro injection moulding

    DEFF Research Database (Denmark)

    Islam, Aminul

    of engineering micro product which integrate many features like beam snapfit, annular snapfit, hinge connection, filter grid, house, lid etc in a single product. All the features are in micro dimensional scale and manufactured by single step of injection moulding. This presentation will cover industrial...

  13. ANN modelling for the determination of moulding sand matrix grain size

    Directory of Open Access Journals (Sweden)

    J. Jakubski

    2011-10-01

    Full Text Available One of the modern methods of the production optimisation are artificial neural networks. Neural networks are gaining broader and broader application in the foundry industry, among others for controlling melting processes in cupolas and in arc furnaces, for designing castings and supply systems, for controlling moulding sand processing, for predicting properties of cast alloys or selecting parameters of pressure castings. An attempt to apply neural networks for controlling the quality of bentonite moulding sands is presented in this paper. This is the assessment method of sands suitability by means of detecting correlations between their individual parameters. The presented investigations were obtained by using the Statistica 9.0 program. The aim of the investigations was to select the neural network suitable for prediction the moulding sand matrix grain size on the basis of the determined sand properties such as: permeability, compactibility, and compressive strength.

  14. Assessment of sub-mm features replication capability in injection moulding using a multi-cavity tool produced by additive manufacturing

    DEFF Research Database (Denmark)

    Davoudinejad, A.; Charalambis, A.; Zhang, Y.

    This research investigates the effect of injection moulding process parameters on photopolymer mould inserts produced with the Digital Light Processing (DLP) additive manufacturing (AM) method. The main motivation of applying AM to produce mould inserts, is the potential of reducing lead time...... and manufacturing cost, as well as achieving a more flexible manufacturing method in case of non-mass produced products such as prototypes. In this research moulds inserts of 20 x 20 x 2.7 mm with mould cavities as small as 5 x 4 mm in dimensions are tested. The parts are analyzed and evaluated by the measurements...

  15. Economic trade-offs of additive manufacturing integration in injection moulding process chain

    DEFF Research Database (Denmark)

    Charalambis, Alessandro; Kerbache, Laoucine; Tosello, Guido

    2017-01-01

    Additive Manufacturing has emerged as an innovative set of novel technologies capable of replacing established manufacturing processes due to fabrication of highly complex parts and its continuous improvements of efficiency and cost effectiveness. This study is based on the idea that through...... the creation of synergies between additive and conventional manufacturing technologies it is possible to achieve greater cost advantages and operational benefits than by substituting injection moulding with additive manufacturing. The analysis presented explores the cost advantages that can be secured when...... additive manufacturing is used to support the fabrication of mould inserts for the product development phase of the injection moulding process chain. This study shows that fabrication of soft tooling by mean of AM is economically convenient with a cost reduction between 80% and 90%. Break-even points...

  16. UV and IR laser radiation's interaction with metal film and teflon surfaces

    Science.gov (United States)

    Fedenev, A. V.; Alekseev, S. B.; Goncharenko, I. M.; Koval', N. N.; Lipatov, E. I.; Orlovskii, V. M.; Shulepov, M. A.; Tarasenko, V. F.

    2003-04-01

    The interaction of Xe ([lambda] [similar] 1.73 [mu]m) and XeCl (0.308 [mu]m) laser radiation with surfaces of metal and TiN-ceramic coatings on glass and steel substrates has been studied. Correlation between parameters of surface erosion versus laser-specific energy was investigated. Monitoring of laser-induced erosion on smooth polished surfaces was performed using optical microscopy. The correlation has been revealed between characteristic zones of thin coatings damaged by irradiation and energy distribution over the laser beam cross section allowing evaluation of defects and adhesion of coatings. The interaction of pulsed periodical CO2 ([lambda] [similar] 10.6 [mu]m), and Xe ([lambda] [similar] 1.73 [mu]m) laser radiation with surfaces of teflon (polytetrafluoroethylene—PTFE) has been studied. Monitoring of erosion track on surfaces was performed through optical microscopy. It has been shown that at pulsed periodical CO2-radiation interaction with teflon the sputtering of polymer with formation of submicron-size particles occurs. Dependencies of particle sizes, form, and sputtering velocity on laser pulse duration and target temperature have been obtained.

  17. Influence of tribological additives on friction and impact performance of injection moulded polyacetal

    DEFF Research Database (Denmark)

    Laursen, Jens Lolle; Sivebæk, Ion Marius; Christoffersen, L.W.

    2009-01-01

    Tribological additives are used to improve frictional properties of injection moulded thermoplastics. The additives might however also affect the mechanical properties of the material. The influence of processing conditions on both frictional and mechanical properties is highly relevant in the de......Tribological additives are used to improve frictional properties of injection moulded thermoplastics. The additives might however also affect the mechanical properties of the material. The influence of processing conditions on both frictional and mechanical properties is highly relevant...... in the development of tribologically modified grades. In the present study we investigate how two commonly used tribological additives, polydimethylsiloxane and polytetrafluoroethylene, affect friction and impact properties of polyacetal (polyoxymethylene). A new injection mould provides test specimens for both...

  18. ALGORITHMS FOR THE PROGRAMMING OF FOOTWEAR SOLES MOULDS ON WORKING POSTS OF INJECTION MACHINES

    Directory of Open Access Journals (Sweden)

    LUCA Cornelia

    2014-05-01

    Full Text Available The moulds stock necessary for realization in rhythmically conditions, a certain volume of footwear soles depends on some criterions such as: the range of soles for footwear volume daily realized, the sizes structure of those soles for footwear and, respectively, the sizes tally, the technological cycle for an used mould depending on the equipment efficiency, the provide necessity of spare moulds, the using and fixing conditions etc. From the efficiency point of view, the equipments may have two working posts, or more working posts (always, an even number, as 6, 12, 24, 40 posts. Footwear soles manufacturing takes into account the percentage distribution of the size numbers of the size series. When o portative assembly is used for the manufacturing of the footwear soles using the injection with “n” working posts, it is very important an optimum distribution of the working posts. The disadvantages of these equipments are the situations of the no equilibrium programming of the moulds, so that, in one time, some working posts spread out of the work. The paper presents some practical and theoretical solutions for moulds stock programming in portative assembly for footwear soles injection, so that an optimum equilibrium degree of the working posts will obtain

  19. Self-leadership and volition: distinct and potentially supplemental constructs?

    Science.gov (United States)

    Heiss, Christian; Ziegler, Matthias; Engbert, Kai; Gröpel, Peter; Brand, Ralf

    2010-10-01

    Self-leadership and volition are conceptually similar concepts. Both propose self-influence strategies that aim to improve the motivation and self-direction necessary to perform well. The present study assesses whether self-leadership strategies maintain construct-specific variance when compared with the similar strategies of volition. Results from a questionnaire study (N=320) indicate that self-leadership and volitional strategies are distinguishable and only moderately (r = .33) correlated. Self-leadership, therefore, supplements volition during goal attainment. Findings are discussed in light of the Rubicon model of action phases.

  20. The Influence of the Content of Furfuryl Alcohol Monomer on the Process of Moulding Sand's Thermal Destruction

    Directory of Open Access Journals (Sweden)

    Dobosz St. M.

    2014-10-01

    Full Text Available The article discusses the issue of the influence of furfuryl alcohol content in resin binders on properties of moulding sand at elevated temperature. Reducing the share of this component - due to the requirements of the European Union regarding its toxicity - may cause a decrease in temperature of moulding sands’ destruction and, consequently, the thermal deformation of moulds and the creation of many casting defects. The study examined the impact of the furfuryl alcohol content of the thermal destruction processes and on the strength of the moulding sand at an ambient temperature and the tendency to thermal deformation.

  1. Experimental measurements and numerical simulation of permittivity and permeability of Teflon in X band

    Directory of Open Access Journals (Sweden)

    Adriano Luiz de Paula

    2011-01-01

    Full Text Available Recognizing the importance of an adequate characterization of radar absorbing materials, and consequently their development, the present study aims to contribute for the establishment and validation of experimental determination and numerical simulation of electromagnetic materials complex permittivity and permeability, using a Teflon® sample. The present paper branches out into two related topics. The first one is concerned about the implementation of a computational modeling to predict the behavior of electromagnetic materials in confined environment by using electromagnetic three-dimensional simulation. The second topic re-examines the Nicolson-Ross-Weir mathematical model to retrieve the constitutive parameters (complex permittivity and permeability of a homogeneous sample (Teflon®, from scattering coefficient measurements. The experimental and simulated results show a good convergence that guarantees the application of the used methodologies for the characterization of different radar absorbing materials samples.

  2. Optimization of Injection Moulding Process Parameters in the ...

    African Journals Online (AJOL)

    ADOWIE PERE

    https://www.ajol.info/index.php/jasem ... Cooling time was found to be the factor with most significant effect on ... Keywords: High Density Polyethylene (HDPE), Injection Moulding, Process .... value of shrinkage behavior is expected to be.

  3. Yield stress distribution in injection-moulded glassy polymers

    NARCIS (Netherlands)

    Verbeeten, W.M.H.; Kanters, M.J.W.; Engels, T.A.P.; Govaert, L.E.

    2015-01-01

    A methodology for structural analysis simulations is presented that incorporates the distribution of mechanical propertiesalong the geometrical dimensions of injection-moulded amorphous polymer products. It is based on a previously developedmodelling approach, where the thermomechanical history

  4. Production of press moulds by plasma spray forming process

    International Nuclear Information System (INIS)

    Borisov, Y.; Myakota, I.; Polyakov, S.

    2001-01-01

    Plasma spray forming process for production of press moulds which are used for manufacture of articles from plastics was developed. The press moulds were produced by plasma spraying of Cu-Al-Fe-alloy powder on surface of a master model. The master models were made from non-metallic materials with heat resistance below 70 C (wood, gypsum etc). Double cooling system which provides for a control of surface model temperature and quenching conditions of sprayed material was designed. It made possible on the one hand to support model surface temperature below 70 C and on the other hand to provide for temperature conditions of martensite transformation in Cu-Al-system with a fixation of metastable ductile α + β 1 -phase. This allowed to decrease residual stresses in sprayed layer (up to 0,5-2,5 MPa), to increase microhardness of the coating material (up to 1200-1800 MPa) and its ductility (σ B = 70-105 MPa, δ = 6-12 %). This plasma spray forming process makes possible to spray thick layers (5-20 mm and more) without their cracking and deformation. The process is used for a production of press moulds which are applied in shoes industry, for fabrication of toys, souvenirs etc. (author)

  5. A framework of cloud supported collaborative design in glass lens moulds based on aspheric measurement

    Science.gov (United States)

    Zhu, Yongjian; Wang, Yu; Na, Jingxin; Zhi, Yanan; Fan, Yufeng

    2013-09-01

    Aspheric mould design includes the top-down design and reversal design. In this paper, a new framework of reversal design is proposed combining with cloud supported collaborative design (CSCD) based on aspheric measurement. The framework is a kind of collaborative platform, which is composed of eight modules, including the computerized aspheric precision measurement module (CAPM), computer-aided optical design of aspheric lens system (CAOD), computer-aided design of lens mould (CADLM), FEM(finite element method) simulation of lens molding module (FEMLM), computer-aided manufacture of lens and moulds (CAMLM), measurement data analysis module (MDAM), optical product lifecycle management module (OPLM) and cloud computing network module (CCNM). In this framework, the remote clients send an improved requirement or fabrication demand about optical lens system through CCNM, which transfers this signal to OPLM. In OPLM, one main server is in charge of the task distribution and collaborative work of other six modules. The first measurement data of aspheric lens are produced by clients or our proposed platform CAPM, then are sent to CAOD for optimization and the electronic drawings of lens moulds are generated in CADLM module. According the design drawings, the FEMLM could give the lens-molding simulation parameters through FEM software. The simulation data are used for the second design of moulds in CADLM module. In this case, the moulds could be fabricated in CAMLM by ultra-precision machine, and the aspheric lens could be also produced by lens-molding machine in CAMLM. At last, the final shape of aspheric lens could be measured in CAPM and the data analysis could be conducted in MDAM module. Through the proposed framework, all the work described above could be performed coordinately. And the optimum design data of lens mould could be realized and saved, then shared by all the work team.

  6. Effects of moulds on the safety and processing quality of Triticum aestivum

    Directory of Open Access Journals (Sweden)

    Šarić Marija D.

    2008-01-01

    Full Text Available Wheat and wheat products are frequently subjected to mould infestations. Many of them are potential producers of various mycotoxins. Some of the consequences, due to the infestations by genus Fusarium and Alternaria, are mostly: yield loss, decrease of biological and technological quality, and unacceptable quality of infected kernels for the production and processing into human food because of the possible presence of mycotoxins. It is unknown whether and how the contaminated grains are distributed during milling into various flour streams and finished products. Wholegrain flours and related products contain all anatomic parts of kernels, including mycotoxins. It is a known fact that mycotoxins are resistant to thermal degradation, so they do not loose their toxicity during processing. Moulds from genus Fusarium spp. and Alternaria spp. synthesize mycotoxins, mostly zearalenon and ochratoxin A. The aim of the investigation was to examine mould contamination of wheat grain, as well as to identify the isolated species, especially those capable of producing toxins, and to determine their impact on technological quality, safety and sanitary condition of wheat. Six varieties of wheat, contaminated with moulds, were investigated. Each sample was separated manually into four fractions: sound kernels, black germ kernels, kernels infected slightly and those infected severely with Fusarium spp.

  7. Mechanical properties test and microstructure analysis of polyoxymethylene (POM) micro injection moulded standard parts

    DEFF Research Database (Denmark)

    Tosello, Guido; Lucchetta, Giovanni; Hansen, Hans Nørgaard

    2009-01-01

    to factorial plans, in which the factors of interest were mould temperature, melt temperature and dimensional range of the specimen (i.e. macro and micro parts). Micro structure analysis was performed by means of plastography techniques and revealed that high mould and melt temperatures resulted on a thin skin...

  8. A capability study of micro moulding for nano fluidic system manufacture

    DEFF Research Database (Denmark)

    Calaon, Matteo; Hansen, Hans Nørgaard; Tosello, Guido

    2013-01-01

    With the present paper the authors analysed process capability of ultra-precision moulding used for producing nano crosses with the same critical channels dimensions of a nano fluidic system for optical mapping of genomic length DNA. The process variation focused on product tolerances is quantified...... through AFM measurements. Uncertainty assessment of measurements on polymer objects is described and quality control results of sub-micro injection moulded crosses are shown in respect of the tolerance range specified by the end user as limit value for functional design....

  9. Criteria for an advanced assessment of quality of moulding sands with organic binders and reclamation process products

    Directory of Open Access Journals (Sweden)

    R. Dańko

    2013-05-01

    Full Text Available Reclamation of used moulding and core sands has been defined as a treatment of waste moulding refractory materials, enabling a recovery of at least one of the components having properties similar to those of the fresh component, and reuse for production of casting moulds and cores. However, at present, there is a lack of a reclaimed material assessment index, which could be applied to each type of moulding sand and reclaim. Modern investigation methods and equipment for the estimation of the quality of the moulding sands matrices with organic binders, in their circulation process, are presented in this paper. These methods, utilizing the special equipment combined with the author’s investigation methods developed in the Faculty of Foundry Engineering, AGH - University of Science and Technology, allow the better estimation of the matrix quality both in an aspect of its application as a fresh sand substitute in the preparation of moulding sands, and also with regard to the environmental protection. The most important criteria for the technological assessment of the reclaimed materials and the quality of sands with organic binders are presented in this paper.

  10. Sealing of polymer micro-structures by over-moulding

    DEFF Research Database (Denmark)

    Vingaard, Mathias; Christiansen, Jesper de Claville

    2012-01-01

    A concept for sealing of polymer micro-structures by over-moulding with polystyrene was devised and investigated by both experiments and simulations. The depth to which the melt filled the structure, i.e. a groove in the surface of the insert, before solidification was compared with results from...... simulations by computational fluid dynamics software. In both experiments and simulations, there was clearly an increase of filling depth with groove width and, especially for wide grooves, with injection temperature. In the simulations, changes in prescribed heat transfer coefficient had the largest effect...... on filling depth in the narrowest grooves. Around the experimental groove widths, there was good agreement between experiments and simulations. It was concluded that sealing by over-moulding is feasible if the depth/width ratio of the structure is large enough which in this paper is larger than six, i.e. up...

  11. Rate of solidification of aluminium casting in varying wall thickness of cylindrical metallic moulds

    Directory of Open Access Journals (Sweden)

    Katsina Christopher BALA

    2014-02-01

    Full Text Available The quality of final casting mainly depends on the rate of solidification as rapid solidification produces fine grains structures with better mechanical properties. The analysis of heat transfer during the casting and solidification of aluminium alloy as well as the experimental investigation of the rate of solidification in varying thicknesses of cylindrical metallic mould was carried out. The temperature variation with time of the casting was recorded from which cooling curves were obtained for the determination of solidification time of the cast. The results showed that as the cylindrical mould thickness increases the solidification time decreases due to the chilling effect of the mould.

  12. Facial asymmetry correction with moulded helmet therapy in infants with deformational skull base plagiocephaly.

    Science.gov (United States)

    Kreutz, Matthias; Fitze, Brigitte; Blecher, Christoph; Marcello, Augello; Simon, Ruben; Cremer, Rebecca; Zeilhofer, Hans-Florian; Kunz, Christoph; Mayr, Johannes

    2018-01-01

    The recommendation issued by the American Academy of Pediatrics in the early 1990s to position infants on their back during sleep to prevent sudden infant death syndrome (SIDS) has dramatically reduced the number of deaths due to SIDS but has also markedly increased the prevalence of positional skull deformation in infants. Deformation of the base of the skull occurs predominantly in very severe deformational plagiocephaly and is accompanied by facial asymmetry, as well as an altered ear position, called ear shift. Moulded helmet therapy has become an accepted treatment strategy for infants with deformational plagiocephaly. The aim of this study was to determine whether facial asymmetry could be corrected by moulded helmet therapy. In this retrospective, single-centre study, we analysed facial asymmetry of 71 infants with severe deformational plagiocephaly with or without deformational brachycephaly who were undergoing moulded helmet therapy between 2009 and 2013. Computer-assisted, three-dimensional, soft-tissue photographic scanning was used to record the head shape before and after moulded helmet therapy. The distance between two landmarks in the midline of the face (i.e., root of the nose and nasal septum) and the right and left tragus were measured on computer-generated indirect and objective 3D photogrammetry images. A quotient was calculated between the two right- and left-sided distances to the midline. Quotients were compared before and after moulded helmet therapy. Infants without any therapy served as a control group. The median age of the infants before onset of moulded helmet therapy was 5 months (range 3-16 months). The median duration of moulded helmet therapy was 5 months (range 1-16 months). Comparison of the pre- and post-treatment quotients of the left vs. right distances measured between the tragus and root of the nose (n = 71) and nasal septum (n = 71) revealed a significant reduction of the asymmetry (Tragus-Nasion-Line Quotient: 0

  13. Teflon granulomas mimicking cerebellopontine angle tumors following microvascular decompression.

    Science.gov (United States)

    Deep, Nicholas L; Graffeo, Christopher S; Copeland, William R; Link, Michael J; Atkinson, John L; Neff, Brian A; Raghunathan, Aditya; Carlson, Matthew L

    2017-03-01

    To report two patients with a history of microvascular decompression (MVD) for hemifacial spasm who presented with Teflon granulomas (TG) mimicking cerebellopontine angle (CPA) tumors and to perform a systematic review of the English-language literature. Case series at a single tertiary academic referral center and systematic review. Retrospective chart review with analysis of clinical, radiological, and histopathological findings. Systematic review using PubMed, Embase, MEDLINE, and Web of Science databases. Two patients with large skull base TGs mimicking CPA tumors clinically and radiographically were managed at the authors' institution. The first presented 4 years after MVD with asymmetrical sensorineural hearing loss, multiple progressive cranial neuropathies, and brainstem edema due to a growing TG. Reoperation with resection of the granuloma confirmed a foreign-body reaction consisting of multinucleated giant cells containing intracytoplasmic Teflon particles. The second patient presented 11 years after MVD with asymmetrical sensorineural hearing loss and recurrent hemifacial spasm. No growth was noted over 2 years, and the patient has been managed expectantly. Only one prior case of TG after MVD for hemifacial spasm has been reported in the English literature. TG is a rare complication of MVD for hemifacial spasm. The diagnosis should be suspected in patients presenting with a new-onset enhancing mass of the CPA after MVD, even when performed decades earlier. A thorough clinical and surgical history is critical toward establishing an accurate diagnosis to guide management and prevent unnecessary morbidity. Surgical intervention is not required unless progressive neurologic complications ensue. 4 Laryngoscope, 127:715-719, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  14. Replication of Micro pillars by PEEK injection moulding with CrN coated Ni tool

    DEFF Research Database (Denmark)

    Zhang, Yang; Hansen, Hans Nørgaard; Sørensen, Søren

    2015-01-01

    A micro-structured nickel insert was investigatedfor polyether ether ketone (PEEK) injection moulding. Themicro-features were circular holes 4 μm in diameter and2 μm deep, with a 2-μm edge-to-edge distance. Six thousand moulding cycles were operated. Half of the insert was coatedby approximately...

  15. Deep reactive ion etching of silicon moulds for the fabrication of diamond x-ray focusing lenses

    Science.gov (United States)

    Malik, A. M.; Fox, O. J. L.; Alianelli, L.; Korsunsky, A. M.; Stevens, R.; Loader, I. M.; Wilson, M. C.; Pape, I.; Sawhney, K. J. S.; May, P. W.

    2013-12-01

    Diamond is a highly desirable material for use in x-ray optics and instrumentation. However, due to its extreme hardness and resistance to chemical attack, diamond is difficult to form into a structure suitable for x-ray lenses. Refractive lenses are capable of delivering x-ray beams with nanoscale resolution. A moulding technique for the fabrication of diamond lenses is reported. High-quality silicon moulds were made using photolithography and deep reactive ion etching. The study of the etch process conducted to achieve silicon moulds with vertical sidewalls and minimal surface roughness is discussed. Issues experienced when attempting to deposit diamond into a high-aspect-ratio mould by chemical vapour deposition are highlighted. Two generations of lenses have been successfully fabricated using this transfer-moulding approach with significant improvement in the quality and performance of the optics observed in the second iteration. Testing of the diamond x-ray optics on the Diamond Light Source Ltd synchrotron B16 beamline has yielded a line focus of sub-micrometre width.

  16. The Impact of Microwave Penetration Depth on the Process of Heating the Moulding Sand with Sodium Silicate

    Directory of Open Access Journals (Sweden)

    Nowak D.

    2017-12-01

    Full Text Available This paper presents the impact of microwave penetration depth on the process of heating the moulding sand with sodium silicate. For each material it is affected by: the wavelength in vacuum and the real and imaginary components of the relative complex electrical permittivity εr for a selected measurement frequency. Since the components are not constant values and they change depending on the electrical parameters of materials and the frequency of the electromagnetic wave, it is indispensable to carry out laboratory measurements to determine them. Moreover, the electrical parameters of materials are also affected by: temperature, packing degree, humidity and conductivity. The measurements of the dielectric properties of moulding sand with sodium silicate was carried out using the perturbation method on a stand of waveguide resonance cavity. The real and imaginary components of the relative complex electrical permittivity was determined for moulding sand at various contents of sodium silicate and at various packing degrees of the samples. On the basis of the results the microwave penetration depth of moulding sand with sodium silicate was established. Relative literature contains no such data that would be essential to predicting an effective process of microwave heating of moulding sand with sodium silicate. Both the packing degree and the amount of sodium silicate in moulding sand turned out to affect the penetration depth, which directly translates into microwave power density distribution in the process of microwave heating of moulding sand with sodium silicate.

  17. Quality of topographical micro replication in injection moulding

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf; Hansen, Hans Nørgaard; Bariani, Paolo

    2003-01-01

    The quality of tool-to-part rough surface topography replication in injection moulding has been investigated. Quantitative descriptors suitable for detecting process conditions induced topography changes have been identified using a statistical criterion. The experimental work is based on a tool ...

  18. Body awareness: construct and self-report measures.

    Directory of Open Access Journals (Sweden)

    Wolf E Mehling

    Full Text Available Heightened body awareness can be adaptive and maladaptive. Improving body awareness has been suggested as an approach for treating patients with conditions such as chronic pain, obesity and post-traumatic stress disorder. We assessed the psychometric quality of selected self-report measures and examined their items for underlying definitions of the construct.PubMed, PsychINFO, HaPI, Embase, Digital Dissertations Database.Abstracts were screened; potentially relevant instruments were obtained and systematically reviewed. Instruments were excluded if they exclusively measured anxiety, covered emotions without related physical sensations, used observer ratings only, or were unobtainable. We restricted our study to the proprioceptive and interoceptive channels of body awareness. The psychometric properties of each scale were rated using a structured evaluation according to the method of McDowell. Following a working definition of the multi-dimensional construct, an inter-disciplinary team systematically examined the items of existing body awareness instruments, identified the dimensions queried and used an iterative qualitative process to refine the dimensions of the construct.From 1,825 abstracts, 39 instruments were screened. 12 were included for psychometric evaluation. Only two were rated as high standard for reliability, four for validity. Four domains of body awareness with 11 sub-domains emerged. Neither a single nor a compilation of several instruments covered all dimensions. Key domains that might potentially differentiate adaptive and maladaptive aspects of body awareness were missing in the reviewed instruments.Existing self-report instruments do not address important domains of the construct of body awareness, are unable to discern between adaptive and maladaptive aspects of body awareness, or exhibit other psychometric limitations. Restricting the construct to its proprio- and interoceptive channels, we explore the current understanding

  19. Effect of gamma radiation on storage moulds of wheat and maize

    International Nuclear Information System (INIS)

    Lal, S.P.; Kapoor, J.N.; Chatrath, M.S.

    1977-01-01

    The effect of different dosages of gamma radiation on the development of moulds on grains of wheat and maize and on the germination of the spores of these fungi was studied. There was marked reduction in storage moulds with increase in the dose and at a dose of 300 Krad, their development on grains was completely inhibited. The results on germination of spores of these fungi when treated with various radiation dosages show that several species of Aspergillus and Penicillium differed remarkably in their sensitivity to radiation. (author)

  20. Two-component injection moulding simulation of ABS-POM micro structured surfaces

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Islam, Aminul

    2013-01-01

    Multi-component micro injection moulding (μIM) processes such as two-component (2k) μIM are the key technologies for the mass fabrication of multi-material micro products. 2k-μIM experiments involving a miniaturized test component with micro features in the sub-mm dimensional range and moulding...... a pair of thermoplastic materials (ABS and POM) were conducted. Three dimensional process simulations based on the finite element method have been performed to explore the capability of predicting filling pattern shape at component-level and surface micro feature-level in a polymer/polymer overmoulding...

  1. Barriers to Construction Health and Safety Self-regulation: A Scoping Case of Nigeria

    Directory of Open Access Journals (Sweden)

    Umeokafor Nnedinma

    2017-03-01

    Full Text Available This scoping study builds on the recent uncovering that in terms of health and safety (H&S, the Nigerian construction industry is self-regulated in various forms, not unregulated and that the size of company can further explain H&S self-regulation. Consequently, the barriers identified through literature review were assessed using questionnaires. Analysis of the data collected from construction practitioners in Nigeria shows that ‘economic factors’ mostly explains the barriers to construction H&S self-regulation. This is followed by the ‘ability to self-regulate’ and ‘lack of awareness’. Furthermore, the results show significant differences among small, medium and large construction contractors on seven factors of which include ‘normative case’ factors, ‘H&S is a duty’, ‘H&S is the right thing’ and ‘unfair H&S standards or legislation’. Although a scoping study, the study draws attention to the barriers to construction H&S self-regulation in Nigeria and demonstrates an alternative to state regulation of H&S.

  2. Advanced oxidation and adsorption modification of dust waste from standard moulding sands

    Directory of Open Access Journals (Sweden)

    A. Baliński

    2010-04-01

    Full Text Available The article discusses the process of advanced oxidation (AO with application of ultrasounds and surface modification of the dust waste collected during dry dedusting of processed moulding sands with bentonite binder. A beneficial effect of both AO and adsorption modification of dust waste, when performed with the selected type of polyelectrolyte, on the technological and mechanical properties of moulding sands prepared with an addition of this dust has been stated. In spite of the bentonite content in moulding sand reduced by 43% and replaced with modified dust waste, the mechanical properties, i.e. the compression and tensile strengths, examined on sand specimens have been improved by 10% and 13%, respectively, with no harm to other basic technological sand properties. At the same time, it was also possible to reduce by about 30% the emission rate of the main gaseous component from the BTEX group, i.e. benzene.

  3. Influence of the mould on the size of A A 8090 alloy in the material melting bulk state

    International Nuclear Information System (INIS)

    Bolfarini, Claudemiro

    1996-01-01

    Wedge like samples were casted into investment moulds of alumina and spodumen. The later were additionally coated with lithium, barium, magnesium and calcium fluorides and chlorides based salts and other special materials. It was used the 2,6% Li-containing alloy AA8090. The grain size was measured as a function of the wedge thickness nd mould material. The results showed a strong dependence of the grain size to the mould materials for the same cast conditions: pouring temperature, mould temperature and chemical composition of the alloy. The AA8090 alloy had no addition of titanium-boron based grain refiner. (author)

  4. The computation of properties of injection-moulded products

    NARCIS (Netherlands)

    Douven, L.F.A.; Baaijens, F.P.T.; Meijer, H.E.H.

    1995-01-01

    Injection moulding is a flexible production technique for the manufacture of complex shaped, thin walled polymer products that require minimal finishing. During processing, the polymer experiences a complex deformation and temperature history that affects the final properties of the product. In a

  5. Characterisation of demoulding parameters in micro‑injection moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Tosello, Guido; Dimov, S.S.

    2015-01-01

    on the process factors that affect parts’ quality. Using a Cyclic Olefin Copolyme (COC) microfluidics demonstrator, the demoulding performance was studied as a function of four process parameters (melt temperature, mould temperature, holding pressure and injection speed), employing the design of experiment...

  6. Effectiveness of Protective Action of Coatings from Moisture Sorption into Surface Layer of Sand Moulds

    Directory of Open Access Journals (Sweden)

    Kaźnica N.

    2016-12-01

    Full Text Available The results of investigations of the sorption process of surface layers of sand moulds covered by zirconium and zirconium - graphite alcohol coatings are presented in the paper. Investigations comprised two kinds of sand grains (silica sand and reclaimed sand of moulding sand with furan resin. Tests were performed under conditions of a high relative air humidity 75 - 85% and a constant temperature within the range 28 – 33°C. To evaluate the effectiveness of coatings protective action from moisture penetration into surface layers of sand moulds gravimetric method of quantitavie moisture sorption and ultrasonic method were applied in measurements.

  7. Active binder content as a factor of the control system of the moulding sand quality

    Directory of Open Access Journals (Sweden)

    J. Jakubski

    2011-01-01

    Full Text Available One of the modern methods of the production optimisation are artificial neural networks. Neural networks are gaining broader and broaderapplication in the foundry industry, among others for controlling melting processes in cupolas and in arc furnaces, for designing castingsand supply systems, for controlling moulding sand processing, for predicting properties of cast alloys or selecting parameters of pressurecastings. An attempt to apply neural networks for controlling the quality of bentonite moulding sands is presented in this paper. This is theassessment method of sands suitability by means of detecting correlations between their individual parameters. The presentedinvestigations were obtained by using the Statistica 9.0 program. The presented investigations were aimed at the selection of the neuralnetwork able to predict the active bentonite content in the moulding sand on the basis of this sand properties such as: permeability,compactibility and the compressive strength. An application of the Statistica program allowed to select automatically the type of networkproper for the representation of dependencies occurring in between the proposed moulding sand parameters. The most advantageousconditions were obtained for the uni-directional multi-layer perception (MLP network. Knowledge of the neural network sensitivity to individual moulding sand parameters, allowed to eliminate not essential ones.

  8. Construction of self-dual codes in the Rosenbloom-Tsfasman metric

    Science.gov (United States)

    Krisnawati, Vira Hari; Nisa, Anzi Lina Ukhtin

    2017-12-01

    Linear code is a very basic code and very useful in coding theory. Generally, linear code is a code over finite field in Hamming metric. Among the most interesting families of codes, the family of self-dual code is a very important one, because it is the best known error-correcting code. The concept of Hamming metric is develop into Rosenbloom-Tsfasman metric (RT-metric). The inner product in RT-metric is different from Euclid inner product that is used to define duality in Hamming metric. Most of the codes which are self-dual in Hamming metric are not so in RT-metric. And, generator matrix is very important to construct a code because it contains basis of the code. Therefore in this paper, we give some theorems and methods to construct self-dual codes in RT-metric by considering properties of the inner product and generator matrix. Also, we illustrate some examples for every kind of the construction.

  9. Performance of silvered Teflon (trademark) thermal control blankets on spacecraft

    Science.gov (United States)

    Pippin, Gary; Stuckey, Wayne; Hemminger, Carol

    1993-01-01

    Silverized Teflon (Ag/FEP) is a widely used passive thermal control material for space applications. The material has a very low alpha/e ratio (less than 0.1) for low operating temperatures and is fabricated with various FEP thicknesses (as the Teflon thickness increases, the emittance increases). It is low outgassing and, because of its flexibility, can be applied around complex, curved shapes. Ag/FEP has achieved multiyear lifetimes under a variety of exposure conditions. This has been demonstrated by the Long Duration Exposure Facility (LDEF), Solar Max, Spacecraft Charging at High Altitudes (SCATHA), and other flight experiments. Ag/FEP material has been held in place on spacecraft by a variety of methods: mechanical clamping, direct adhesive bonding of tapes and sheets, and by Velcro(TM) tape adhesively bonded to back surfaces. On LDEF, for example, 5-mil blankets held by Velcro(TM) and clamping were used for thermal control over 3- by 4-ft areas on each of 17 trays. Adhesively bonded 2- and 5-mil sheets were used on other LDEF experiments, both for thermal control and as tape to hold other thermal control blankets in place. Performance data over extended time periods are available from a number of flights. The observed effects on optical properties, mechanical properties, and surface chemistry will be summarized in this paper. This leads to a discussion of performance life estimates and other design lessons for Ag/FEP thermal control material.

  10. A prospective randomized trial of Teflon versus polyethylene stents for distal malignant biliary obstruction

    NARCIS (Netherlands)

    van Berkel, A. M.; Boland, C.; Redekop, W. K.; Bergman, J. J.; Groen, A. K.; Tytgat, G. N.; Huibregtse, K.

    1998-01-01

    Clogging of biliary stents continues to be a major clinical problem. Different polymer materials may have different effects on clogging. In vitro studies have shown a direct relation between the frictional coefficient of a polymer and the amount of encrusted material. Teflon appeared to be the best

  11. The effect of ambient ozone and humidity on the performance of nylon and Teflon filters used in ambient air monitoring filter-pack systems

    Science.gov (United States)

    PE Padgett

    2010-01-01

    Nylon and Teflon filter media are frequently used for monitoring ambient air pollutants. These media are subject to many environmental factors that may influence adsorption and retention of particulate and gaseous nitrogenous pollutants. This study evaluated the effects of ozone and humidity on the efficacy of nylon and Teflon filters used in the US dry deposition...

  12. Characterisation and detection of spoilage mould responsible for black spot in dry-cured fermented sausages.

    Science.gov (United States)

    Lozano-Ojalvo, Daniel; Rodríguez, Alicia; Cordero, Mirian; Bernáldez, Victoria; Reyes-Prieto, Mariana; Córdoba, Juan J

    2015-02-01

    Moulds responsible for black spot spoilage of dry-cured fermented sausages were characterised. For this purpose, samples were taken from those dry-cured fermented sausages which showed black spot alteration. Most of the mould strains were first tentatively identified as Penicillium spp. due to their morphological characteristics in different culture conditions, with one strain as Cladosporium sp. The Cladosporium strain was the only one which provoked blackening in culture media. This strain was further characterised by sequencing of ITS1-5.8S-ITS2 rRNA and β-tubulin genes. This mould strain was able to reproduce black spot formation in dry-cured fermented sausage 'salchichón' throughout the ripening process. In addition, a specific and sensitive real-time PCR method was also developed to detect Cladosporium oxysporum responsible for the black spot formation in sausages. This method could be of great interest for the meat industry to detect samples contaminated with this mould before spoilage of product avoiding economic losses for this sector.

  13. Influence of the recycled material percentage on the rheological behaviour of HDPE for injection moulding process.

    Science.gov (United States)

    Javierre, C; Clavería, I; Ponz, L; Aísa, J; Fernández, A

    2007-01-01

    The amount of polymer material wasted during thermoplastic injection moulding is very high. It comes from both the feed system of the part, and parts necessary to set up the mould, as well as the scrap generated along the process due to quality problems. The residues are managed through polymer recycling that allows reuse of the materials in the manufacturing injection process. Recycling mills convert the parts into small pieces that are used as feed material for injection, by mixing the recycled feedstock in different percentages with raw material. This mixture of both raw and recycled material modifies material properties according to the percentage of recycled material introduced. Some of the properties affected by this modification are those related to rheologic behaviour, which strongly conditions the future injection moulding process. This paper analyzes the rheologic behaviour of material with different percentages of recycled material by means of a capillary rheometer, and evaluates the influence of the corresponding viscosity curves obtained on the injection moulding process, where small variations of parameters related to rheological behaviour, such as pressure or clamping force, can be critical to the viability and cost of the parts manufactured by injection moulding.

  14. Wood Flour Moulding Technology: Implications for Technical ...

    African Journals Online (AJOL)

    User

    2011-04-19

    Apr 19, 2011 ... be waste product from saw mills, wood working plants or produced from selected dry wood by .... Stop watch-used to indicate the exact time the mould has remained in the press before wood .... There is abundance of saw dust the source of which is the ... Madison, Wisconsin: Wiley Interscience. Usoro, H. S. ...

  15. Wood Flour Moulding Technology: Implications for Technical ...

    African Journals Online (AJOL)

    The intent of this article is to demonstrate how wood waste called sawdust or wood flour can be transformed by plastic moulding machine into items of economic value. Wood flour is wood reduced to very fine particle form. It can be waste product from saw mills, wood working plants or produced from selected dry wood by ...

  16. Optimisation of warpage on plastic injection moulding part using response surface methodology (RSM) and genetic algorithm method (GA)

    Science.gov (United States)

    Miza, A. T. N. A.; Shayfull, Z.; Nasir, S. M.; Fathullah, M.; Hazwan, M. H. M.

    2017-09-01

    In this study, Computer Aided Engineering was used for injection moulding simulation. The method of Design of experiment (DOE) was utilize according to the Latin Square orthogonal array. The relationship between the injection moulding parameters and warpage were identify based on the experimental data that used. Response Surface Methodology (RSM) was used as to validate the model accuracy. Then, the RSM and GA method were combine as to examine the optimum injection moulding process parameter. Therefore the optimisation of injection moulding is largely improve and the result shown an increasing accuracy and also reliability. The propose method by combining RSM and GA method also contribute in minimising the warpage from occur.

  17. Assessment of Mould Growth for Library Buildings in Tropical Climates

    Directory of Open Access Journals (Sweden)

    Ngah Abdul Wahab S.

    2014-01-01

    Full Text Available This paper attempt to give a brief insight into the importance of studying mould growth in library building that relates to human health and causes of material deterioration to library materials. It’s significant to conduct this research because no similar study has carried out for a library building in Malaysia. Recent literature on the topics reviews to gain insight into developing a theoretical framework and research method. Likewise, the study also supports through pilot study questionnaires with 30 respondents from two different university libraries. The finding revealed to further investigation and mould growth assessment to be conducted that useful in protecting library materials and users health effects through environmental control.

  18. Cellular automaton model of crowd evacuation inspired by slime mould

    Science.gov (United States)

    Kalogeiton, V. S.; Papadopoulos, D. P.; Georgilas, I. P.; Sirakoulis, G. Ch.; Adamatzky, A. I.

    2015-04-01

    In all the living organisms, the self-preservation behaviour is almost universal. Even the most simple of living organisms, like slime mould, is typically under intense selective pressure to evolve a response to ensure their evolution and safety in the best possible way. On the other hand, evacuation of a place can be easily characterized as one of the most stressful situations for the individuals taking part on it. Taking inspiration from the slime mould behaviour, we are introducing a computational bio-inspired model crowd evacuation model. Cellular Automata (CA) were selected as a fully parallel advanced computation tool able to mimic the Physarum's behaviour. In particular, the proposed CA model takes into account while mimicking the Physarum foraging process, the food diffusion, the organism's growth, the creation of tubes for each organism, the selection of optimum tube for each human in correspondence to the crowd evacuation under study and finally, the movement of all humans at each time step towards near exit. To test the model's efficiency and robustness, several simulation scenarios were proposed both in virtual and real-life indoor environments (namely, the first floor of office building B of the Department of Electrical and Computer Engineering of Democritus University of Thrace). The proposed model is further evaluated in a purely quantitative way by comparing the simulation results with the corresponding ones from the bibliography taken by real data. The examined fundamental diagrams of velocity-density and flow-density are found in full agreement with many of the already published corresponding results proving the adequacy, the fitness and the resulting dynamics of the model. Finally, several real Physarum experiments were conducted in an archetype of the aforementioned real-life environment proving at last that the proposed model succeeded in reproducing sufficiently the Physarum's recorded behaviour derived from observation of the aforementioned

  19. Micro injection moulding process optimization of an ultra-small POM three-dimensional component

    DEFF Research Database (Denmark)

    Baruffi, Federico; Calaon, Matteo; Tosello, Guido

    Replication-based manufacturing processes are a cost effective method for producing complex and net-shaped components [1]. Micro injection moulding has a prominent place among them for its capability of accurately and precisely produce micro plastic parts in large production scale [2], [3......]. In this study, the optimization of the micro injection moulding process of an ultra-small (volume: 0.07 mm3; mass: 0.1 mg) three-dimensional Polyoxymethylene (POM) micro component for medical applications (see Figure 1) is presented. Preliminary experiments highlighted the need for venting channels in order...... with respect to design specifications, the flash areal size was utilized as quality indicator. A design of the experiments approach was carried out in order to study the effects of melt temperature, mould temperature, holding pressure and injection speed. For this task, a two-level full factorial design...

  20. Injection Moulding of Plastic Parts with Surface Microstructures

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf; Hansen, Hans Nørgaard; Kjær, Erik Michael

    2003-01-01

    structures with heights of 9 µm and aspect ratios from 0.2 to 1. For topographical characterisation a confocal laser scanning microscope was used. The injection moulding process conditions were varied over the recommended process window for the material, and the process was analysed using commercial...

  1. Micro-MID Manufacturing By Two-Shot Injection Moulding

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2008-01-01

    a specific MID process chain is used for micro products, many technical challenges are encountered which would not be problems for macro scale products. This paper investigates on a specific MID process chain (two shot moulding) and discusses the technical difficulties associated with the production process...

  2. Shape Accuracy of Iron Precision Castings in Terms of Ceramic Moulds Physical Properties Anisotropy

    Directory of Open Access Journals (Sweden)

    Biernacki R.

    2014-03-01

    Full Text Available While analyzing shape accuracy of ferroalloy precision castings in terms of ceramic moulds physical anisotropy, low-alloy steel castings ("cover" and cast iron ("plate" were included. The basic parameters in addition to the product linear shape accuracy are flatness deviations, especially due to the expanded flat surface which is cast plate. For mentioned castings surface micro-geometry analysis was also carried, favoring surface load capacity tp50 for Rmax = 50%. Surface load capacity tp50 obtained for the cast cover was compared with machined product, and casting plate surface was compared with wear part of the conveyor belt. The results were referred to anisotropy of ceramic moulds physical properties, which was evaluated by studying ceramic moulds samples in computer tomography equipment Metrotom 800

  3. Dynamic Double Curvature Mould System

    DEFF Research Database (Denmark)

    Jepsen, Christian Raun; Kristensen, Mathias Kræmmergaard; Kirkegaard, Poul Henning

    2011-01-01

    The present paper describes a concept for a reconfigurable mould surface which is designed to fit the needs of contemporary architecture. The core of the concept presented is a dynamic surface manipulated into a given shape using a digital signal created directly from the CAD drawing of the design....... This happens fast, automatic and without production of waste, and the manipulated surface is fair and robust, eliminating the need for additional, manual treatment. Limitations to the possibilities of the flexible form are limited curvature and limited level of detail, making it especially suited for larger...

  4. Management self-assessment in construction phase of nuclear power station

    International Nuclear Information System (INIS)

    Shao Bixiu

    2004-01-01

    Management self-assessment is one of the quality management methods to achieve the organization's continuous improvement. Through the investigation of the methods, the author hopes to give guideline to the management at all levels involved in the construction of nuclear power station in the implementation of management self-assessment, and also to make the management self-assessment more normalized, systematical and effective

  5. High Power Picosecond Laser Surface Micro-texturing of H13 Tool Steel and Pattern Replication onto ABS Plastics via Injection Moulding

    Science.gov (United States)

    Otanocha, Omonigho B.; Li, Lin; Zhong, Shan; Liu, Zhu

    2016-03-01

    H13 tool steels are often used as dies and moulds for injection moulding of plastic components. Certain injection moulded components require micro-patterns on their surfaces in order to modify the physical properties of the components or for better mould release to reduce mould contamination. With these applications it is necessary to study micro-patterning to moulds and to ensure effective pattern transfer and replication onto the plastic component during moulding. In this paper, we report an investigation into high average powered (100 W) picosecond laser interactions with H13 tool steel during surface micro-patterning (texturing) and the subsequent pattern replication on ABS plastic material through injection moulding. Design of experiments and statistical modelling were used to understand the influences of laser pulse repetition rate, laser fluence, scanning velocity, and number of scans on the depth of cut, kerf width and heat affected zones (HAZ) size. The characteristics of the surface patterns are analysed. The process parameter interactions and significance of process parameters on the processing quality and efficiency are characterised. An optimum operating window is recommended. The transferred geometry is compared with the patterns generated on the dies. A discussion is made to explain the characteristics of laser texturing and pattern replication on plastics.

  6. Production of Steel Casts in Two-Layer Moulds with Alkaline Binders Part 1. Backing sand with the alkaline inorganic binder RUDAL

    Directory of Open Access Journals (Sweden)

    M. Holtzer

    2011-04-01

    Full Text Available Steel casts in Z.N. POMET were produced in moulds made of the moulding sand Floster. This sand did not have good knocking outproperties, required a significant binder addition (4.5-5.0 parts by weight, and the casting surface quality gave rise to clients objections.Therefore a decision of implementing two-layer moulds, in which the facing sand would consist of the moulding sand with an alkalineorganic binder while the backing sand would be made of the moulding sand with an inorganic binder also of an alkaline character - wasundertaken. The fraction of this last binder in the moulding sand mass would be smaller than that of the binder used up to now (waterglass. The application of two moulding sands of the same chemical character (highly alkaline should facilitate the reclamation processand improve the obtained reclaimed material quality, due to which it would be possible to increase the reclaim fraction in the mouldingsand (up to now it was 50%. The results of the laboratory investigations of sands with the RUDAL binder are presented in the paper.

  7. Conditions of Thermal Reclamation Process Realization on a Sample of Spent Moulding Sand from an Aluminum Alloy Foundry Plant

    Directory of Open Access Journals (Sweden)

    Łucarz M.

    2017-06-01

    Full Text Available The results of investigations of thermal reclamation of spent moulding sands originating from an aluminum alloy foundry plant are presented in this paper. Spent sands were crushed by using two methods. Mechanical fragmentation of spent sand chunks was realized in the vibratory reclaimer REGMAS. The crushing process in the mechanical device was performed either with or without additional crushing-grinding elements. The reclaimed material obtained in this way was subjected to thermal reclamations at two different temperatures. It was found that a significant binder gathering on grain surfaces favors its spontaneous burning, even in the case when a temperature lower than required for the efficient thermal reclamation of furan binders is applied in the thermal reclaimer. The burning process, initiated by gas burners in the reclaimer chamber, generates favorable conditions for self-burning (at a determined amount of organic binders on grain surfaces. This process is spontaneously sustained and decreases the demand for gas. However, due to the significant amount of binder, this process is longer than in the case of reclaiming moulding sand prepared with fresh components.

  8. Electrodynamic tailoring of self-assembled three-dimensional electrospun constructs

    Science.gov (United States)

    Reis, Tiago C.; Correia, Ilídio J.; Aguiar-Ricardo, Ana

    2013-07-01

    The rational design of three-dimensional electrospun constructs (3DECs) can lead to striking topographies and tailored shapes of electrospun materials. This new generation of materials is suppressing some of the current limitations of the usual 2D non-woven electrospun fiber mats, such as small pore sizes or only flat shaped constructs. Herein, we pursued an explanation for the self-assembly of 3DECs based on electrodynamic simulations and experimental validation. We concluded that the self-assembly process is driven by the establishment of attractive electrostatic forces between the positively charged aerial fibers and the already collected ones, which tend to acquire a negatively charged network oriented towards the nozzle. The in situ polarization degree is strengthened by higher amounts of clustered fibers, and therefore the initial high density fibrous regions are the preliminary motifs for the self-assembly mechanism. As such regions increase their in situ polarization electrostatic repulsive forces will appear, favoring a competitive growth of these self-assembled fibrous clusters. Highly polarized regions will evidence higher distances between consecutive micro-assembled fibers (MAFs). Different processing parameters - deposition time, electric field intensity, concentration of polymer solution, environmental temperature and relative humidity - were evaluated in an attempt to control material's design.The rational design of three-dimensional electrospun constructs (3DECs) can lead to striking topographies and tailored shapes of electrospun materials. This new generation of materials is suppressing some of the current limitations of the usual 2D non-woven electrospun fiber mats, such as small pore sizes or only flat shaped constructs. Herein, we pursued an explanation for the self-assembly of 3DECs based on electrodynamic simulations and experimental validation. We concluded that the self-assembly process is driven by the establishment of attractive

  9. Investigating the effects of laser beams (532 and 660 nm) in annihilation of pistachio mould fungus using spectrophotometry analysis

    Science.gov (United States)

    Saghafi, S.; Penjweini, R.; Becker, K.; Kratky, K. W.; Dodt, H.-U.

    2010-09-01

    When moulds are illuminated by visible electromagnetic-EM radiations, several effects on nucleus materials and nucleotides can be detected. These effects have a significant influence on mould generation or destruction. This paper presents the effects and implications of a red diode laser beam (660 nm), a second-harmonics of a Nd:YAG laser emitting green beam (532 nm), or the combination of both, on the eradication of Pistachio mould fungus. Incident doses (ID) of both beams are kept identical throughout the experiment. The absorption spectrums of irradiated mouldy samples and the bright-greenish-yellow-fluorescence (BGYF) of fungus occurring in mould texture due to electronic excitation are investigated. We found that a combination of a green and a red laser beam with an ID of 0.5 J/cm2 provides the optimal effects on Pistachio mould fungus eradication.

  10. Synthesis of perm-selective membranes by grafting acrylic acid into air-irradiated Teflon-FEP films

    Science.gov (United States)

    Bozzi, Annick; Chapiro, Adolphe

    Grafting acrylic acid into air-irradiated Teflon-FEP films was investigated. Pre-irradiation doses ranged from 0.5 to 10 kGy. Grafting occurred at 45 or 60°C. Homopolymerization inhibitors, ferrous ions or methylene blue, were added to the system. It was found that after completion of the reaction, within 40-100 min, membranes were obtained with very low electric resistivities. The influence of added inhibitors, pre-irradiation dose and grafting temperature was studied. From the results it is concluded that the initiating centers in air-irradiated Teflon-FEP are, on the one hand, peroxides of structure POOP', in which P is a polymeric radical and Pprime; a small fragment, and on the other trapped PO .2 radicals. The latter only react after losing their oxygen. In the presence of polymerization inhibitors, initiation involves a redox process which reduces the overall activation energy.

  11. Synthesis of perm-selective membranes by grafting acrylic acid into air-irradiated Teflon-FEP films

    International Nuclear Information System (INIS)

    Bozzi, Annick; Chapiro, Adolphe

    1988-01-01

    Grafting acrylic acid into air-irradiated Teflon-FEP films was investigated. Pre-irradiation doses ranged from 0.5 to 10 kGy. Grafting occurred at 45 or 60 0 C. Homopolymerization inhibitors, ferrous ions or methylene blue, were added to the system. It was found that after completion of the reaction, within 40-100 min, membranes were obtained with very low electric resistivities. The influence of added inhibitors, pre-irradiation dose and grafting temperature was studied. From the results it is concluded that the initiating centers in air-irradiated Teflon-FEP are, on the one hand, peroxides of structure POOP', in which P is a polymeric radical and P' a small fragment, and on the other hand trapped PO 2 sup(·) radicals. The latter only react after losing their oxygen. In the presence of polymerization inhibitors, initiation involves a redox process which reduces the overall activation energy. (author)

  12. Inhibitory Properties of Lactic Acid Bacteria against Moulds Associated with Spoilage of Bakery Products

    OpenAIRE

    I. A. Adesina; A. O. Ojokoh; D. J. Arotupin

    2017-01-01

    Aim: To evaluate the potentiality of LAB strains isolated from different fermented products to inhibit moulds associated with spoilage of bakery products. Methodology: Lactic acid bacterial (LAB) strains obtained from fermented products (“burukutu”, “pito”, yoghurt, and “iru”) were screened for antifungal activity against moulds (Aspergillus flavus, Aspergillus fumigatus, Aspergillus repens and Penicillium sp.) isolated from spoilt bakery products. Inhibitory activities of the lactic acid...

  13. 42 CFR 137.291 - May Self-Governance Tribes carry out construction projects without assuming these Federal...

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false May Self-Governance Tribes carry out construction... OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Construction Nepa Process § 137.291 May Self-Governance Tribes carry out construction projects without assuming these Federal environmental...

  14. Mycotoxin production capability of Penicillium roqueforti in strains isolated from mould-ripened traditional Turkish civil cheese.

    Science.gov (United States)

    Cakmakci, Songul; Gurses, Mustafa; Hayaloglu, A Adnan; Cetin, Bulent; Sekerci, Pinar; Dagdemir, Elif

    2015-01-01

    Mould-ripened civil is a traditional cheese produced mainly in eastern Turkey. The cheese is produced with a mixture of civil and whey curd cheeses (lor). This mixture is pressed into goat skins or plastic bags and is ripened for more than three months. Naturally occurring moulds grow on the surface and inside of the cheese during ripening. In this research, 140 Penicillium roqueforti strains were isolated from 41 samples of mould-ripened civil cheese collected from Erzurum and around towns in eastern Turkey. All strains were capable of mycotoxin production and were analysed using an HPLC method. It was established that all the strains (albeit at very low levels) produced roquefortine C, penicillic acid, mycophenolic acid and patulin. The amounts of toxins were in the ranges 0.4-47.0, 0.2-43.6, 0.1-23.1 and 0.1-2.3 mg kg(-1), respectively. Patulin levels of the samples were lower than the others. The lowest level and highest total mycotoxin levels were determined as 1.2 and 70.1 mg kg(-1) respectively. The results of this preliminary study may help in the choice of secondary cultures for mould-ripened civil cheese and other mould-ripened cheeses.

  15. Are motorways rational from slime mould's point of view?

    NARCIS (Netherlands)

    Adamatzky, A.; Akl, S.; Alonso-Sanz, R.; van Dessel, W.; Ibrahim, Z.; Ilachinski, A.; Jones, J.; Kayem, A.V.D.M.; Martínez, G.J.; de Oliveira, P.; Prokopenko, M.; Schubert, T.; Sloot, P.; Strano, E.; Yang, X.-S.

    2013-01-01

    We analyse the results of our experimental laboratory approximation of motorway networks with slime mould Physarum polycephalum. Motorway networks of 14 geographical areas are considered: Australia, Africa, Belgium, Brazil, Canada, China, Germany, Iberia, Italy, Malaysia, Mexico, the Netherlands, UK

  16. Self-Efficacy as a Positive Youth Development Construct: A Conceptual Review

    Directory of Open Access Journals (Sweden)

    Sandra K. M. Tsang

    2012-01-01

    Full Text Available Self-efficacy denotes people's beliefs about their ability to perform in different situations. It functions as a multilevel and multifaceted set of beliefs that influence how people feel, think, motivate themselves, and behave during various tasks. Self-efficacy beliefs are informed by enactive attainment, vicarious experience, imaginal experiences, and social persuasion as well as physical and emotional states. These beliefs are mediated by cognitive, motivational, affective, and selection processes to generate actual performance. Self-efficacy development is closely intertwined with a person's experiences, competencies, and developmental tasks in different domains at different stages in life. This paper reviews the literature to outline the definition and theoretical conceptualizations of the construct originally devised by Bandura that have flourished since the 1990s. Drawing from the studies of the construct to assess self-efficacy, and to inform positive youth development, the paper will present the determinants of the development of self-efficacy beliefs and identify the connection between self-efficacy and adolescent developmental outcomes. The paper will conclude with strategies to enhance youth self-efficacy and proposals for future research directions.

  17. Self-Efficacy as a Positive Youth Development Construct: A Conceptual Review

    Science.gov (United States)

    Tsang, Sandra K. M.; Hui, Eadaoin K. P.; Law, Bella C. M.

    2012-01-01

    Self-efficacy denotes people's beliefs about their ability to perform in different situations. It functions as a multilevel and multifaceted set of beliefs that influence how people feel, think, motivate themselves, and behave during various tasks. Self-efficacy beliefs are informed by enactive attainment, vicarious experience, imaginal experiences, and social persuasion as well as physical and emotional states. These beliefs are mediated by cognitive, motivational, affective, and selection processes to generate actual performance. Self-efficacy development is closely intertwined with a person's experiences, competencies, and developmental tasks in different domains at different stages in life. This paper reviews the literature to outline the definition and theoretical conceptualizations of the construct originally devised by Bandura that have flourished since the 1990s. Drawing from the studies of the construct to assess self-efficacy, and to inform positive youth development, the paper will present the determinants of the development of self-efficacy beliefs and identify the connection between self-efficacy and adolescent developmental outcomes. The paper will conclude with strategies to enhance youth self-efficacy and proposals for future research directions. PMID:22645423

  18. Brachytherapy at the Institut Gustave-Roussy: Personalized vaginal mould applicator: technical modification and improvement

    International Nuclear Information System (INIS)

    Albano, M.; Dumas, I.; Haie-Meder, C.

    2008-01-01

    Brachytherapy plays an important role in the treatment of patients with gynaecological cancers. At the Institut Gustave-Roussy, the technique of vaginal mould applicator has been used for decades. This technique allows a personalized tailored irradiation, integrating tumour shape, size and extension and vaginal anatomy. Vaginal expansion reduces the dose to the vaginal mucosa and to the organs at risk. We report a modification of the material used for vaginal mould manufacture. The advantages of the new material are a lighter weight, and transparency allowing a better accuracy in the placement of catheters for radioactive sources. This material is applicable for low dose-rate, pulse dose-rate and high dose-rate brachytherapy. Since 2001, more than 700 vaginal moulds have been manufactured with this new approach without any intolerance. (authors)

  19. Production Of Hollow Toy Product From Radiation Pre vulcanized Natural Rubber Latex (RVNRL) By Using Casting And Moulding Technique

    International Nuclear Information System (INIS)

    Mohd Noorwadi Mat Lazim; Sofian Ibrahim; Muhammad Saiful Omar

    2013-01-01

    Hollow toy products are very synonym to the child from the age of months since it able to stimulating each of their sense such as sight, hearing, taste, touch and smell. Most of hollow toy products are made from natural rubber latex by using moulding and casting technique. The moulding and casting technique is a manufacturing process by pored liquid latex into a mould, which contain cavity of the desired shape. The mould made from plaster of Paris able to absorbs water from latex meanwhile the presence of calcium ions from plaster of Paris will tend to diffuse into latex thus promote formation of deposit on surface of cavity mould. To improve the quality and safety of hollow toy product made from latex, Radiation Pre vulcanized Natural Rubber Latex (RVNRL) has been identified to be used because it can fulfill the standard requirement for latex and also due to its special abilities such as lower modulus (soft latex products), nitrosamines free, low in nitrosatables, free from chemical accelerators induced allergies and better biodegradability. This paper identify the problem appears from the process of making hollow toy products from RVNRL by using moulding and casting technique. (author)

  20. Study of process parameters effect on the filling phase of micro injection moulding using weld lines as flow markers

    DEFF Research Database (Denmark)

    Tosello, Guido; Gava, Alberto; Hansen, Hans Nørgaard

    2010-01-01

    , the relationships between the filling pattern and the different process parameter settings have to be established. In this paper, a novel approach based on the use of weld lines as flow markers to trace the development of the flow front during the filling is proposed. The effects on the filling stage of process......Micro-injection moulding (micro-moulding) is a process which enables the mass production of polymer microproducts. In order to produce high-quality injection moulded micro-parts, a crucial aspect to be fully understood and optimised is the filling of the cavity by the molten polymer. As a result...... manufactured by micro-electrodischarge machining. A commercially available polystyrene grade polymer has been moulded using a high-speed injection moulding machine. The design of experiment technique was employed to determine the effect of the process parameters on the filling phase of the micro...

  1. Binder Development for Metal Injection Moulding: A CSIR Perspective

    CSIR Research Space (South Africa)

    Machaka, R

    2014-05-01

    Full Text Available The paper reviews the CSIR’s progress and challenges concerning the development of a wax-based binder system suitable for metal injection moulding (MIM). It reports on a consolidation study wherein different widely used wax-based feedstock...

  2. Characteristics of high-purity Teflon vial for 14C measurement in old tree rings

    International Nuclear Information System (INIS)

    Sakurai, H.; Saswaki, Y.; Matsumoto, T.; Aoki, T.; Kato, W.; Gandou, T.; Gunji, S.; Tokanai, F.

    2003-01-01

    14 C concentration in single-year tree rings of an old cedar of ca. 2500 years ago is measured to investigate the 11-yr periodicity of solar activity. Our highly accurate 14 C measuring system is composed of a benzene synthesizer capable of producing a large quantity (10 g) of benzene and a Quantulus 1220 TM liquid scintillation counting system. The accuracy is less than 0.2% for measurements of 14 C concentration. The benzene sample is contained in a high-purity Teflon/copper-counting vial (20 ml) manufactured by Wallac Oy Company. We found a vial with an irregular copper cap for the measurements of 11 tree rings. The behavior of the vial with the irregular cap was investigated. The Teflon sheet inside the cap plays an important role in achieving stable measurement. The rate of volatilization of the benzene was less than 0.35 mg/day for vials with ordinary caps. This results in the volatilization rate of 0.003% for 10.5 g of benzene and hence guarantees measurement at an accuracy of 0.2% for 70 days

  3. Selected laboratory evaluations of the whole-water sample-splitting capabilities of a prototype fourteen-liter Teflon churn splitter

    Science.gov (United States)

    Horowitz, A.J.; Smith, J.J.; Elrick, K.A.

    2001-01-01

    A prototype 14-L Teflon? churn splitter was evaluated for whole-water sample-splitting capabilities over a range of sediment concentratons and grain sizes as well as for potential chemical contamination from both organic and inorganic constituents. These evaluations represent a 'best-case' scenario because they were performed in the controlled environment of a laboratory, and used monomineralic silica sand slurries of known concentration made up in deionized water. Further, all splitting was performed by a single operator, and all the requisite concentration analyses were performed by a single laboratory. The prototype Teflon? churn splitter did not appear to supply significant concentrations of either organic or inorganic contaminants at current U.S. Geological Survey (USGS) National Water Quality Laboratory detection and reporting limits when test samples were prepared using current USGS protocols. As with the polyethylene equivalent of the prototype Teflon? churn, the maximum usable whole-water suspended sediment concentration for the prototype churn appears to lie between 1,000 and 10,000 milligrams per liter (mg/L). Further, the maximum grain-size limit appears to lie between 125- and 250-microns (m). Tests to determine the efficacy of the valve baffle indicate that it must be retained to facilitate representative whole-water subsampling.

  4. Using Personal Construct Theory to Explore Self-Image with Adolescents with Learning Disabilities

    Science.gov (United States)

    Thomas, Samantha; Butler, Richard; Hare, Dougal Julian; Green, David

    2011-01-01

    A young person's construct of self can be fundamental to their psychological well being (Glick 1999; Emler 2001). However limited research has been conducted in the United Kingdom to explore self-image with adolescents with learning disabilities. Previous studies have demonstrated the effective use of personal construct theory with children…

  5. Chances with self made collectors in Slovakia. Self-construction movement in Austria

    International Nuclear Information System (INIS)

    Benesch, B.; Huschner, J.

    2005-01-01

    Author presented self-construction movement in Austria together with practical experiences presented by Josef Huschner from Pyhra Solar organisation. As mentioned movement has long tradition in Austria and brought valuable input for next sector of solar energy utilisation development, Austrian partners started discussion about possibilities of initiate similar movement in Slovakia

  6. Fast Surface Temperature Measurement of Teflon Propellant in Pulsed Ablative Discharges Using HgCdTe Photovoltaic Cells (PREPRINT)

    National Research Council Canada - National Science Library

    Antonsen, Erik L; Burton, Rodney L; Reed, Garrett A; Spanjers, Gregory G

    2006-01-01

    ... ablative discharge with Teflon(TradeMark) as the ablated material. Analysis is used to derive a governing equation for detector output voltage for materials with wavelength dependent emissivity...

  7. [Study on the quantitative and qualitative composition of moulds colonizing sunflower seeds (Helianthus annus L.)].

    Science.gov (United States)

    Janda, Katarzyna; Wolska, Jolanta; Debia, Kamila

    2015-01-01

    The aim of study was to estimate the qualitative and quantitative composition of moulds colonizing sunflower seeds on RBCA, YpSs, DG18 media at 25, 37, and 45°C. Twenty samples of sunflower seeds (not roasted and not salted) were used for the analysis. The highest number of moulds were xerophilic species isolated on DG18 at 25°C (33), followed by mesophilic species (29) on RBCA medium at 25°C, and mesophilic (22) and thermophilic species (10) on YpSs medium at 37, and 45°C, respectively. Eurotium herbariorum was isolated from all samples. A total of 287 strains belonging to 52 mould species were isolated from sunflower seeds. The study revealed new species not previously isolated from sunflower seeds mycobiota.

  8. Manufacturing of kevlar/polyester composite by resin transfer moulding using conventional and microwave heating

    International Nuclear Information System (INIS)

    Abdullah, I.

    2015-01-01

    Microwave heating was incorporated into the resin transfer moulding technique. Polytetrafluoroethylene (PTFE) mould was used to cure the composite panel. Through the use of microwave heating, the mechanical and physical properties of produced Kevlar fibre/polyester composites were compared to those manufactured by conventional resin transfer moulding. The flexural modulus and flexural strength of 6-ply conventionally cured composites was 45% and 9% higher than the flexural modulus and flexural strength of 6-ply microwaved cured composites, respectively. However, 19% increase in interlaminar shear strength (ILSS) and 2% increase in compressive strength was observed in 6-ply microwave cured composites. This enhancement in ILSS and compressive strength is attributed to the better interfacial bonding of polyester resin with Kevlar fibres in microwaved cured composite, which was also confirmed via electron microscopy scanning. Furthermore, the microwave cured composite yielded maximum void contents (3%). (author)

  9. Induction Heating System Applied to Injection Moulding of Micro and Nano Structures

    DEFF Research Database (Denmark)

    Menotti, Stefano

    The present Ph.D. thesis contains a study concerning induction heating system applied to injection moulding of micro and nano structures. The overall process chain was considered and investigated during the project including part design, simulation, conventional and non-conventional tooling...... part. In fact one of the main problems in micro injection moulding is the premature freezing of the polymer flow inside the cavity and often is not possible to obtain a full replica of the nano/micro structures embed on the surfaces. Some other defects that can be avoided with the use of an additional...

  10. THE WEAR OF INJECTION MOULD FUNCTIONAL PARTS IN CONTACT WITH POLYMER COMPOSITES

    Directory of Open Access Journals (Sweden)

    Janette Brezinová

    2009-02-01

    Full Text Available The paper deals with the evaluation of material wear of injection moulds made of aluminium alloy Alumec 89 and copper alloy Moldmax HH in friction couples with plastomer materials with various filler contents. The friction relations in injection moulding were simulated in an adhesion dry wear test using an Amsler machine, with an area contact of the friction couple materials. The wear intensity was evaluated by determination of friction coefficient and relative wearing by the mass loss. Surface morphology changes of evaluated alloys after wear and the thermal conditions in particular friction couples were analysed simultaneously.

  11. Electroplating moulds using dry film thick negative photoresist

    Science.gov (United States)

    Kukharenka, E.; Farooqui, M. M.; Grigore, L.; Kraft, M.; Hollinshead, N.

    2003-07-01

    This paper reports on progress on the feasibility of fabricating moulds for electroplating using Ordyl P-50100 (negative) acrylate polymer based dry film photoresist, commercially available from Elga Europe (http://www.elgaeurope.it). We used this photoresist as an alternative to SU8 negative epoxy based photoresist, which is very difficult to process and remove after electroplating (Lorenz et al 1998 Microelectron. Eng. 41/42 371-4, Eyre et al 1998 Proc. MEMS'98 (Heidelberg) (Piscataway, NJ: IEEE) pp 218-22). Ordyl P-50100 is easy to work with and can be easily removed after processing. A single layer of Ordyl P-50100 was deposited by lamination up to 20 µm thickness. Thicker layers (200 µm and more) can be achieved with multilayer lamination using a manual laminator. For our applications we found that Ordyl P-50100 dry film photoresist is a very good alternative to SU8 for the realization of 100 µm high moulds. The results presented will open up new possibilities for low-cost LIGA-type processes for MEMS applications.

  12. 78 FR 12357 - Brockway Mould, Inc., a Division of Ross International Ltd. Including Robert Lerch From BJR...

    Science.gov (United States)

    2013-02-22

    ... Division of Ross International Ltd. Including Robert Lerch From BJR Trucking, Brockport, PA; Amended..., applicable to workers and former workers of Brockway Mould, Inc., a division of Ross International Ltd... Brockway Mould, Inc., a division of Ross International Ltd., including Robert Lerch from BJR Trucking...

  13. Construction and initial validation of the self-worth protection scale.

    Science.gov (United States)

    Thompson, Ted; Dinnel, Dale L

    2003-03-01

    The self-worth theory of achievement motivation holds that in certain circumstances students stand to gain by deliberately withdrawing effort. When failure occurs despite effort, students are likely to conclude that failure resulted from lack of ability. Thus, withdrawing effort offers a defence against conclusions of low ability, thereby protecting self-worth. We undertook to assess the psychometric properties of the Self-Worth Protection Scale (SWPS). Data were obtained from 243 participants (Study 1) and 411 participants (Study 2) enrolled in undergraduate psychology courses at a university in the United States. We administered a number of scales, including the SWPS and scales assessing a fear of negative evaluation, academic self-esteem, uncertain global self-evaluations, self-handicapping, and causal uncertainty. Exploratory factor analysis indicated a three-factor solution (ability doubts, the importance of ability as a criterion of self-worth, and an avoidance orientation) utilising 33 of the original 44 items. A confirmatory factor analysis indicated that this three-factor solution was a poor fit of the data. After modifying the model, a confirmatory factor analysis indicated that a three-factor solution with 26 of the original items and a higher order factor of self-worth protection was an adequate fit of the data. Reliability measures were acceptable for the three subscales and total score. The total score of the SWPS was positively correlated with theoretically related constructs, demonstrating construct validity. The SWPS appears to be a psychometrically sound scale to assist in identifying individuals who manifest self-worth protection in achievement situations.

  14. Effect of selenium on control of postharvest gray mould of tomato fruit and the possible mechanisms involved

    Directory of Open Access Journals (Sweden)

    Zhilin eWu

    2016-01-01

    Full Text Available Selenium (Se has important benefits for crop growth and stress tolerance at low concentrations. However, there is very little information on antimicrobial effect of selenium against the economically important fungus Botrytis cinerea. In the present study, using sodium selenite as Se source, we investigated the effect of Se salts on spore germination and mycelial growth of the fungal pathogen in vitro and gray mould control in harvested tomato fruit. Se treatment at 24 mg/L significantly inhibited spore germination of the fungal pathogen and effectively controlled gray mould in harvested tomato fruit. Se treatment at 24 mg/L seems to induce the generation of intracellular reactive oxygen species in the fungal spores. The membrane integrity damage was observed with fluorescence microscopy following staining with propidium iodide after treatment of the spores with Se. These results suggest that Se has the potential for controlling gray mould rot of tomato fruits and might be useful in integrated control against gray mould disease of postharvest fruits and vegetables caused by B. cinerea. The mechanisms by which Se decreased gray mould decay of tomato fruit may be directly related to the severe damage to the conidia plasma membrane and loss of cytoplasmic materials from the hyphae.

  15. Microbiological contamination with moulds in work environment in libraries and archive storage facilities.

    Science.gov (United States)

    Zielinska-Jankiewicz, Katarzyna; Kozajda, Anna; Piotrowska, Malgorzata; Szadkowska-Stanczyk, Irena

    2008-01-01

    Microbiological contamination with fungi, including moulds, can pose a significant health hazard to those working in archives or museums. The species involved include Aspergillus, Penicillium, Geotrichum, Alternaria, Cladosporium, Mucor, Rhizopus, Trichoderma, Fusarium which are associated mostly with allergic response of different types. The aim of the study was to analyse, both in quantitative and qualitative terms, workplace air samples collected in a library and archive storage facilities. Occupational exposure and the related health hazard from microbiological contamination with moulds were assessed in three archive storage buildings and one library. Air samples (total 60) were collected via impact method before work and at hourly intervals during work performance. Surface samples from the artifacts were collected by pressing a counting (RODAC) plate filled with malt extract agar against the surface of the artifacts. The air sample and surface sample analyses yielded 36 different mould species, classified into 19 genera, of which Cladosporium and Penicillium were the most prevalent. Twelve species were regarded as potentially pathogenic for humans: 8 had allergic and 11 toxic properties, the latter including Aspergillus fumigatus. Quantitative analysis revealed air microbiological contamination with moulds at the level ranging from 1.8 x 10(2)-2.3 x 10(3) cfu/m(3). In surface samples from library and archive artifacts, 11 fungal species were distinguished; the number of species per artifact varying from 1-6 and colony count ranging from 4 x 10(1) to 8-10(1) cfu/100 cm(2). Higher contamination levels were found only for Cladosporium cladosporioides (1.48 x 10(3) cfu/100 cm(2)) and Paecillomyces varioti (1.2 x 10(2) cfu/100 cm(2)). At the workposts examined, although no clearly visible signs of mould contamination could be found, the study revealed abundant micromycetes, with the predominant species of Cladosporium and Penicillium. The detected species included

  16. Final Report: Self Consolidating Concrete Construction for Modular Units

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, Russell [Georgia Inst. of Technology, Atlanta, GA (United States); Kahn, Lawrence [Georgia Inst. of Technology, Atlanta, GA (United States); Kurtis, Kimberly [Georgia Inst. of Technology, Atlanta, GA (United States); Petrovic, Bojan [Georgia Inst. of Technology, Atlanta, GA (United States); Loreto, Giovanni [Georgia Inst. of Technology, Atlanta, GA (United States); Van Wyk, Jurie [Westinghouse Electric Company, Cranberry Township, PA (United States); Canterero-Leal, Carlos [Westinghouse Electric Company, Cranberry Township, PA (United States)

    2016-07-29

    This report outlines the development of a self-consolidating concrete (also termed “self-compacting concrete” or SCC) so that concrete placement can be made into steel plate composite (SC) modular structures without the need for continuous concrete placement. As part of the research, SCC mixtures were developed and validated to ensure sufficient shear capacity across cold-joints, while minimizing shrinkage and temperature increase during curing to enhance concrete bonding with the steel plate construction found in modular units. The self-roughening concrete produced as part of this research was assessed in SC structures at three scales: small-scale shear-friction specimens, mid-scale beams tested in in-plane and out-of-plane bending, and a full-scale validation test using an SC module produced by Westinghouse as part of the Plant Vogtle expansion. The experiments show that the self-roughening concrete can produce a cold-joint surface of 0.25 inches (6 mm) without external vibration during concrete placement. The experiments and subsequent analysis show that the shear friction provisions of ACI 318-14, Section 22.9 can be used to assess the shear capacity of the cold-joints in SC modular construction, and that friction coefficient of 1.35 is appropriate for use with these provisions.

  17. Harmfulness Assessment of Moulding Sands with a Geopolymer Binder and a New Hardener, in An Aspect of the Emission of Substances from the Btex Group

    Directory of Open Access Journals (Sweden)

    Bobrowski A.

    2015-04-01

    Full Text Available The harmfulness assessment of moulding sands with a geopolymer binder and a new hardener, in an aspect of the emission of substances from the BTEX group, was performed. Within the expedience project the new series of hardeners for the inorganic GEOPOL binder was developed. Before the introduction of the new system of moulding sands it was necessary to estimate their influence on the environment. To this aim the gasses emission from moulding sands subjected to the influence of liquid cast iron was tested with regard to the content of the gases from the BTEX group (benzene, toluene, ethylbenzene and xylenes. For the comparison the analogous investigations of the up to now applied moulding sands with the geopolymer binder, were performed. It was found that both systems of moulding sands binding emit similar amounts of gases, as well as similar amounts of substances from the BTEX group. Moulding sands with the GEOPOL binder are much more environmentally friendly than moulding sands with organic binders. The content of the BTEX group substances in gases emitted from moulding sands with the GEOPOL binder was approximately 10-times lower than in case of the moulding sands with organic binders.

  18. Accurate characterisation of post moulding shrinkage of polymer parts

    DEFF Research Database (Denmark)

    Neves, L. C.; De Chiffre, L.; González-Madruga, D.

    2015-01-01

    The work deals with experimental determination of the shrinkage of polymer parts after injection moulding. A fixture for length measurements on 8 parts at the same time was designed and manufactured in Invar, mounted with 8 electronic gauges, and provided with 3 temperature sensors. The fixture w...

  19. Hope and General Self-efficacy: Two Measures of the Same Construct?

    Science.gov (United States)

    Zhou, Mingming; Kam, Chester Chun Seng

    2016-07-03

    The aim of this study was to test the extent to which hope measure is equivalent to general self-efficacy measure. Questionnaire data on these two constructs and other external variables were collected from 199 Chinese college students. The factor analytic results suggested that hope and self-efficacy items measured the same construct. The unidimensional model combining hope items and GSE items fit the data as well as the bidimensional model, indicating that their corresponding items measured the same underlying construct. Further analyses showed that hope and GSE did not correlate with external variables differently in a systematic manner. Most of these correlational differences were non-significant and negligible. These findings suggested that the literatures studying GSE and hope could be considered to be integrated and that researchers need to recognize and acknowledge the conceptual and operational similarities among these constructs in the literature.

  20. A new approach for the validation of filling simulations in micro injection moulding

    DEFF Research Database (Denmark)

    Gava, Alberto; Tosello, Guido; Lucchetta, Giovanni

    2007-01-01

    In manufacturing polymer micro products, numerical simulations are used with the same purposes as in conventional injection moulding, mainly the optimization of micro components design, the optimization of process parameters and the decrease of production costs. Dedicated simulations softwares fail...... to be improved. The main objective of this work is to evaluate whether the present numerical codes are suitable to characterize melt flow patterns in a micro cavity. In order to test the accuracy of the software, real and simulated experiments were performed and used to investigate the filling of a micro moulded...

  1. Effects of gas–wall partitioning in Teflon tubing and instrumentation on time-resolved measurements of gas-phase organic compounds

    Directory of Open Access Journals (Sweden)

    D. Pagonis

    2017-12-01

    Full Text Available Recent studies have demonstrated that organic compounds can partition from the gas phase to the walls in Teflon environmental chambers and that the process can be modeled as absorptive partitioning. Here these studies were extended to investigate gas–wall partitioning of organic compounds in Teflon tubing and inside a proton-transfer-reaction mass spectrometer (PTR-MS used to monitor compound concentrations. Rapid partitioning of C8–C14 2-ketones and C11–C16 1-alkenes was observed for compounds with saturation concentrations (c∗ in the range of 3 × 104 to 1 × 107 µg m−3, causing delays in instrument response to step-function changes in the concentration of compounds being measured. These delays vary proportionally with tubing length and diameter and inversely with flow rate and c∗. The gas–wall partitioning process that occurs in tubing is similar to what occurs in a gas chromatography column, and the measured delay times (analogous to retention times were accurately described using a linear chromatography model where the walls were treated as an equivalent absorbing mass that is consistent with values determined for Teflon environmental chambers. The effect of PTR-MS surfaces on delay times was also quantified and incorporated into the model. The model predicts delays of an hour or more for semivolatile compounds measured under commonly employed conditions. These results and the model can enable better quantitative design of sampling systems, in particular when fast response is needed, such as for rapid transients, aircraft, or eddy covariance measurements. They may also allow estimation of c∗ values for unidentified organic compounds detected by mass spectrometry and could be employed to introduce differences in time series of compounds for use with factor analysis methods. Best practices are suggested for sampling organic compounds through Teflon tubing.

  2. Effects of gas-wall partitioning in Teflon tubing and instrumentation on time-resolved measurements of gas-phase organic compounds

    Science.gov (United States)

    Pagonis, Demetrios; Krechmer, Jordan E.; de Gouw, Joost; Jimenez, Jose L.; Ziemann, Paul J.

    2017-12-01

    Recent studies have demonstrated that organic compounds can partition from the gas phase to the walls in Teflon environmental chambers and that the process can be modeled as absorptive partitioning. Here these studies were extended to investigate gas-wall partitioning of organic compounds in Teflon tubing and inside a proton-transfer-reaction mass spectrometer (PTR-MS) used to monitor compound concentrations. Rapid partitioning of C8-C14 2-ketones and C11-C16 1-alkenes was observed for compounds with saturation concentrations (c∗) in the range of 3 × 104 to 1 × 107 µg m-3, causing delays in instrument response to step-function changes in the concentration of compounds being measured. These delays vary proportionally with tubing length and diameter and inversely with flow rate and c∗. The gas-wall partitioning process that occurs in tubing is similar to what occurs in a gas chromatography column, and the measured delay times (analogous to retention times) were accurately described using a linear chromatography model where the walls were treated as an equivalent absorbing mass that is consistent with values determined for Teflon environmental chambers. The effect of PTR-MS surfaces on delay times was also quantified and incorporated into the model. The model predicts delays of an hour or more for semivolatile compounds measured under commonly employed conditions. These results and the model can enable better quantitative design of sampling systems, in particular when fast response is needed, such as for rapid transients, aircraft, or eddy covariance measurements. They may also allow estimation of c∗ values for unidentified organic compounds detected by mass spectrometry and could be employed to introduce differences in time series of compounds for use with factor analysis methods. Best practices are suggested for sampling organic compounds through Teflon tubing.

  3. FE-Analysis of Stretch-Blow Moulded Bottles Using an Integrative Process Simulation

    Science.gov (United States)

    Hopmann, C.; Michaeli, W.; Rasche, S.

    2011-05-01

    The two-stage stretch-blow moulding process has been established for the large scale production of high quality PET containers with excellent mechanical and optical properties. The total production costs of a bottle are significantly caused by the material costs. Due to this dominant share of the bottle material, the PET industry is interested in reducing the total production costs by an optimised material efficiency. However, a reduced material inventory means decreasing wall thicknesses and therewith a reduction of the bottle properties (e.g. mechanical properties, barrier properties). Therefore, there is often a trade-off between a minimal bottle weight and adequate properties of the bottle. In order to achieve the objectives Computer Aided Engineering (CAE) techniques can assist the designer of new stretch-blow moulded containers. Hence, tools such as the process simulation and the structural analysis have become important in the blow moulding sector. The Institute of Plastics Processing (IKV) at RWTH Aachen University, Germany, has developed an integrative three-dimensional process simulation which models the complete path of a preform through a stretch-blow moulding machine. At first, the reheating of the preform is calculated by a thermal simulation. Afterwards, the inflation of the preform to a bottle is calculated by finite element analysis (FEA). The results of this step are e.g. the local wall thickness distribution and the local biaxial stretch ratios. Not only the material distribution but also the material properties that result from the deformation history of the polymer have significant influence on the bottle properties. Therefore, a correlation between the material properties and stretch ratios is considered in an integrative simulation approach developed at IKV. The results of the process simulation (wall thickness, stretch ratios) are transferred to a further simulation program and mapped on the bottles FE mesh. This approach allows a local

  4. Construction and Validation of the Self-Conscious Emotions at Work Scale

    Directory of Open Access Journals (Sweden)

    Hans Groenvynck

    2011-11-01

    Full Text Available The present study reports on the construction and validation of a new assessment instrument for self-conscious emotions in the work context, namely the Self-Conscious Emotions at Work Scale (SCEWS. In eight typical self-conscious work scenarios respondents have to indicate their emotional reaction in terms of 20 appraisals, subjective experiences, and action tendencies that are relevant and representative for the domain of self-conscious emotions. In total 512 students and 467 working adults completed the SCEWS and reported the frequency of positive emotions, anger, anxiety and sadness. In both samples a three-factorial structure emerged with a guilt, a shame/humiliation, and an anger in self-conscious situations factor. These three self-conscious emotion factors correlated differentially and in a predicted way with the frequency of emotions. Guilt-proneness was predicted to be psychologically constructive and correlated to the frequency of positive emotions. The proneness to shame/humiliation was expected to relate to internalising psychopathological tendencies, and positively correlated to a frequency of anxiety and sadness. Proneness to anger in self-conscious situations was expected to relate to externalising psychopathological tendencies and correlated with the frequency of anger in general. The present study demonstrates that self-conscious emotions can be validly measured in the work context. The new instrument allows for the systematic study of the role of self-conscious emotions in work and organisational behaviour.

  5. Adsorption of IgG onto hydrophobic teflon. Differences between the F(ab) and F(c) domains

    NARCIS (Netherlands)

    Vermeer, AWP; Giacomelli, CE; Norde, W

    2001-01-01

    The effect of differences in the degree of hydrophobicity of protein patches/fragments on the adsorption behaviour of the protein is investigated. The adsorption isotherm of a monoclonal mouse anti-human immunoglobulin G (isotype 2b) onto hydrophobic Teflon particles is measured using a depletion

  6. Occurrence of mycotoxins and yeasts and moulds identification in corn silages in tropical climate.

    Science.gov (United States)

    Carvalho, B F; Ávila, C L S; Krempser, P M; Batista, L R; Pereira, M N; Schwan, R F

    2016-05-01

    This study was aimed to identify yeasts and moulds as well as to detect mycotoxin in corn silages in southern Minas Gerais, Brazil. Corn silages from 36 farms were sampled to analyse dry matter, crude protein, ether extract, ash, neutral detergent fibre, nonfibre carbohydrates and mycotoxins contents, yeasts and moulds population, pH and temperature values. The mycotoxins found in high frequency were aflatoxin in 77·7% of analysed samples, ochratoxin (33·3%) and zearalenone (22·2%). There was no significant correlation between the mycotoxin concentration and the presence of moulds. The pH was negatively correlated with ochratoxin concentration. Aspergillus fumigatus was identified in all silages that presented growth of moulds. Ten different yeast species were identified using the culture-dependent method: Candida diversa, Candida ethanolica, Candida rugosa, Issatchenkia orientalis, Kluyveromyces marxianus, Pichia manshurica, Pichia membranifaciens, Saccharomyces cerevisiae, Trichosporon asahii and Trichosporon japonicum. Another six different yeast species were identified using the culture-independent method. A high mycotoxin contamination rate (91·6% of the analysed silages) was observed. The results indicated that conventional culturing and PCR-DGGE should be combined to optimally describe the microbiota associated with corn silage. This study provides information about the corn silage fermentation dynamics and our findings are relevant to optimization of this silage fermentation. © 2016 The Society for Applied Microbiology.

  7. Development and Evaluation of Mould for Double Curved Concrete Elements

    DEFF Research Database (Denmark)

    Jepsen, Christian Raun; Kristensen, Mathias Kræmmergaard; Kirkegaard, Poul Henning

    2011-01-01

    freeform concrete formwork are available, and more are being developed [1-4]. The common way of producing moulds for unique elements today is to manufacture one mould for each unique element using CNC milling in cheaper materials, but since the method is still labour intensive and produces a lot of waste......Complex freeform architecture is one of the most striking trends in contemporary architecture. Architecture differs from traditional target industries of CAD/CAM technology in many ways including aesthetics, statics, structural aspects, scale and manufacturing technologies. Designing a piece...... of freeform architecture in a CAD program is fairly easy, but the translation to a real piece of architecture can be difficult and expensive and as traditional production methods for free-form architecture prove costly, architects and engineers are forced to simplify designs. Today, methods for manufacturing...

  8. The use of sodium carbonate to improve curing treatments against green and blue moulds on citrus fruits.

    Science.gov (United States)

    Plaza, Pilar; Usall, Josep; Torres, Rosario; Abadias, Maribel; Smilanick, Joseph L; Viñas, Immaculada

    2004-08-01

    The effectiveness of curing oranges and lemons at 33 degrees C for 65h followed by storage under ambient and cold-storage conditions was investigated. This treatment effectively reduced the incidence of Penicillium digitatum (Pers) Sacc and P italicum Wehmer decay on inoculated and naturally infected oranges and lemons stored at 20 degrees C for 7 days. However, it failed to control green and blue mould infections on fruits placed in long-term cold storage, except green mould on oranges, which was effectively controlled. Dipping fruits in a sodium carbonate solution (20 g litre(-1)) for 2.5 min following a curing treatment at 33 degrees C for 65 h satisfactorily reduced green and blue mould incidence during subsequent long-term storage at 4 degrees C on oranges and at 10 degrees C on lemons. The efficacy was greater on injured fruits inoculated after the combination of treatments was applied, achieving a 60-80% reduction in decay in comparison with the curing treatment alone in all cases. A significant reduction of blue mould was also observed on fruits inoculated both before the treatments and on those re-inoculated after the treatments, demonstrating both protectant and eradicant activity. Thus, combining curing at 33 degrees C for 65 h with sodium carbonate treatment effectively controlled these post-harvest diseases on artificially inoculated citrus fruits and protected against re-infection. With naturally inoculated lemons, curing followed by sodium carbonate significantly reduced both green and blue mould incidence, but was not superior to curing alone. With naturally infected oranges, curing significantly reduced blue mould, but decay was not reduced further when followed by sodium carbonate treatment.

  9. Study of the conductivity induced by radiation in teflon irradiated by X-ray

    International Nuclear Information System (INIS)

    Faria, R.M.

    1980-01-01

    It's measured the X-ray induced currents in teflon FEP which show the following features: a) At the beginning the current increases and reaches a maximum at about 10s, b) It decays slowly during 30 minutes, when a steady state is reached the delayed conductivity was also measured. The sample were 25 μm thick and the irradiated area was 12,5 cm 2 ; the applied field was of the order of 10 4 V/cm and the dose rate of order of 10 2 R/S. It was observed that a new measurement of the induced conductivity does not duplicate the first one, but after a few hours it comes back to the original one. In order to show that the increase and the decrease of the current is not caused by an electric field effect we realized a measurement where we polled the sample intermitently while it was irradiated. The current thus obtained had about the same values of the first measurement, when the voltage was applied all the time during the measurement. The absorption current of a teflon sample which shows after some days the effect of its variation due the variation of the ambiental temperature are measured. (Author) [pt

  10. Smith-Petersen Vitallium mould arthroplasty: a 62-year follow-up.

    LENUS (Irish Health Repository)

    Baker, J F

    2011-09-01

    A variety of materials were used for early hip prostheses. The introduction of Vitallium by Smith-Petersen represented a further advance in this surgical field. We present the longest known follow-up of a Smith-Petersen Vitallium mould arthroplasty.

  11. Magic with moulds: Meiotic and mitotic crossing over in Neurospora ...

    Indian Academy of Sciences (India)

    2006-02-16

    Feb 16, 2006 ... Home; Journals; Journal of Biosciences; Volume 31; Issue 1. Commentary: Magic with moulds: Meiotic and mitotic crossing over in Neurospora inversions and duplications. Durgadas P Kasbekar. Volume 31 Issue 1 March 2006 pp 3-4 ...

  12. Final Report: Self-Consolidating Concrete Construction for Modular Units

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, Russell [Georgia Inst. of Technology, Atlanta, GA (United States); Kahn, Lawrence [Georgia Inst. of Technology, Atlanta, GA (United States); Kurtis, Kimberly [Georgia Inst. of Technology, Atlanta, GA (United States); Petrovic, Bojan [Georgia Inst. of Technology, Atlanta, GA (United States); Loreto, Giovanni [Georgia Inst. of Technology, Atlanta, GA (United States); Van Wyk, Jurie [Westinghouse Inc., Cranberry Township, PA (United States); Canterero-Leal, Carlos [Westinghouse Inc., Cranberry Township, PA (United States)

    2016-07-29

    This report focuses on work completed on DE-NE0000667, Self-Consolidating Concrete for Modular Units, in connection with the Department of Energy Nuclear Energy Enabling Technologies (DOE-NEET) program. This project was completed in the School of Civil and Environmental Engineering at the Georgia Institute of Technology, with Westinghouse Corporation as the industrial partner. The primary objective of this project was to develop self-consolidating concrete (also termed “self-compacting concrete” or SCC) mixtures so that concrete placement can be made into steel plate composite (SC) modular structures without the need for continuous concrete placement. As part of the research, SCC mixtures were developed and validated to ensure sufficient shear capacity across cold-joints, while minimizing shrinkage and temperature increase during curing to enhance concrete bonding with the steel plate construction found in modular units. The SCC mixtures developed were able to carry shearing forces across the cold-joint boundaries. This “self-roughening” was achieved by adding a tailored fraction of lightweight aggregate (LWA) to the concrete mix, some of which raised to the surface during curing, forming a rough surface on which subsequent concrete placements were made. The self-roughening behavior was validated through three sets of structural tests. Shear friction on small-scale specimens with cold joints was assessed using varying fractions of LWA and with varying amounts of external steel plate reinforcement. The results show that the shear friction coefficient, to be used with the provisions of ACI 318-14, Section 22.9, can be taken as 1.35. Mid-scale beam tests were completed to assess the cold-joint capacity in both in-plane and out-of-plane bending. The results showed that the self-roughened joints performed as well as monolithic joints. The final assessment was a full-scale test using a steel composite module supplied by Westinghouse and similar in construction to

  13. Final Report: Self-Consolidating Concrete Construction for Modular Units

    International Nuclear Information System (INIS)

    Gentry, Russell; Kahn, Lawrence; Kurtis, Kimberly; Petrovic, Bojan; Loreto, Giovanni; Van Wyk, Jurie; Canterero-Leal, Carlos

    2016-01-01

    This report focuses on work completed on DE-NE0000667, Self-Consolidating Concrete for Modular Units, in connection with the Department of Energy Nuclear Energy Enabling Technologies (DOE-NEET) program. This project was completed in the School of Civil and Environmental Engineering at the Georgia Institute of Technology, with Westinghouse Corporation as the industrial partner. The primary objective of this project was to develop self-consolidating concrete (also termed ''self-compacting concrete'' or SCC) mixtures so that concrete placement can be made into steel plate composite (SC) modular structures without the need for continuous concrete placement. As part of the research, SCC mixtures were developed and validated to ensure sufficient shear capacity across cold-joints, while minimizing shrinkage and temperature increase during curing to enhance concrete bonding with the steel plate construction found in modular units. The SCC mixtures developed were able to carry shearing forces across the cold-joint boundaries. This ''self-roughening'' was achieved by adding a tailored fraction of lightweight aggregate (LWA) to the concrete mix, some of which raised to the surface during curing, forming a rough surface on which subsequent concrete placements were made. The self-roughening behavior was validated through three sets of structural tests. Shear friction on small-scale specimens with cold joints was assessed using varying fractions of LWA and with varying amounts of external steel plate reinforcement. The results show that the shear friction coefficient, to be used with the provisions of ACI 318-14, Section 22.9, can be taken as 1.35. Mid-scale beam tests were completed to assess the cold-joint capacity in both in-plane and out-of-plane bending. The results showed that the self-roughened joints performed as well as monolithic joints. The final assessment was a full-scale test using a steel composite module supplied by

  14. Warpage optimisation on the moulded part with straight-drilled and conformal cooling channels using response surface methodology (RSM) and glowworm swarm optimisation (GSO)

    Science.gov (United States)

    Hazwan, M. H. M.; Shayfull, Z.; Sharif, S.; Nasir, S. M.; Zainal, N.

    2017-09-01

    In injection moulding process, quality and productivity are notably important and must be controlled for each product type produced. Quality is measured as the extent of warpage of moulded parts while productivity is measured as a duration of moulding cycle time. To control the quality, many researchers have introduced various of optimisation approaches which have been proven enhanced the quality of the moulded part produced. In order to improve the productivity of injection moulding process, some of researches have proposed the application of conformal cooling channels which have been proven reduced the duration of moulding cycle time. Therefore, this paper presents an application of alternative optimisation approach which is Response Surface Methodology (RSM) with Glowworm Swarm Optimisation (GSO) on the moulded part with straight-drilled and conformal cooling channels mould. This study examined the warpage condition of the moulded parts before and after optimisation work applied for both cooling channels. A front panel housing have been selected as a specimen and the performance of proposed optimisation approach have been analysed on the conventional straight-drilled cooling channels compared to the Milled Groove Square Shape (MGSS) conformal cooling channels by simulation analysis using Autodesk Moldflow Insight (AMI) 2013. Based on the results, melt temperature is the most significant factor contribute to the warpage condition and warpage have optimised by 39.1% after optimisation for straight-drilled cooling channels and cooling time is the most significant factor contribute to the warpage condition and warpage have optimised by 38.7% after optimisation for MGSS conformal cooling channels. In addition, the finding shows that the application of optimisation work on the conformal cooling channels offers the better quality and productivity of the moulded part produced.

  15. Effects of carbon fibres on the life cycle assessment of additively manufactured injection moulding inserts for rapid prototyping

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Bey, Niki; Mischkot, Michael

    2017-01-01

    properties and lifetime. The additively manufactured inserts are compared to the standard materials steel, aluminium and brass. The investigated part of the production and prototyping phase considers the insert itself, the moulded part, and resulting waste material of the injection moulding process....

  16. Relations between Minuchin's Structural Family Model and Kohut's Self-Psychology Constructs.

    Science.gov (United States)

    Perosa, Linda

    1996-01-01

    Examines relationship between structural family model and self-psychology constructs. College women (n=164) completed the Structural Family Interaction Scale-Revised (SFIS-R), the Parental Relations Inventory, and the Goal Instability and Superiority scales from the Self-Expression Inventory. Indicated that women raised in families with strong…

  17. Birefringence in heat-mechanical modified freshly moulded polyester fibers

    Energy Technology Data Exchange (ETDEWEB)

    Velev, V; Dimov, T; Popov, A; Denev, Y; Hristov, H; Angelov, T; Markova, K; Zagortcheva, M; Arhangelova, N; Uzunov, N, E-mail: v.velev@shu-bg.ne

    2010-11-01

    The article submits new experimental data concerning to the role of combined thermo-mechanical treatments on the structural development of freshly moulded uncrystallized but crystallizable poly (ethylene terephthalate) (PET) fibers. The object of the present work is PET as a thermoplastic polymer with a large practical application. The report is devoted to the influence of the heat-mechanical modification temperature on the structure rearrangement in uniaxially orientated amorphous PET. The heat-mechanical modification of the investigated yarns and the optical measurements were realized by specialized gears constructed and built in the author's laboratories. The fibers heat-mechanical modification includes samples annealing at constant temperature above their glass transition temperature (T{sub g}) without strain stress. The yarn annealing has been followed from well defined uniaxially strain-loading with values from 0 MPa up to 30 MPa during two minutes. The optical measurements were carried out by an optical system using a polarization microscope and a CCD camera. The obtained experimental data has been analyzed by Mocha-1.2 (Jandel Scientific) software. There are established dependences between the heat-mechanical modification mode and the structural rearrangements running in the studied PET samples.

  18. Kine-Mould : Manufacturing technology for curved architectural elements in concrete

    NARCIS (Netherlands)

    Schipper, H.R.; Eigenraam, P.; Grünewald, S.; Soru, M.; Nap, P.; Van Overveld, B.; Vermeulen, J.

    2015-01-01

    The production of architectural elements with complex geometry is challenging for concrete manufacturers. Computer-numerically-controlled (CNC) milled foam moulds have been applied frequently in the last decades, resulting in good aesthetical performance. However, still the costs are high and a

  19. Closed-Loop Tension Control System for Injection Moulding Machine

    African Journals Online (AJOL)

    When the mould unit is full, this drive keeps transporting filament materials without proper control. This project developed a closed loop feedback tension control system and it is to replace servo motor drive system for the transportation of filament and it demonstrated a new technological advancement and the theory of ...

  20. Investigations of the Quality of the Reclaim of Spent Moulding Sands with Organic Binders

    Directory of Open Access Journals (Sweden)

    R. Dańko

    2012-09-01

    Full Text Available Modern investigation methods and equipment for the quality estimation of the moulding sands matrices with organic binders, in theircirculation process, are presented in the paper. These methods, utilising the special equipment combined with the authors investigationmethods developed in the Faculty of Foundry Engineering, AGH the University of Science and Technology, allow for the better estimationof the matrix quality. Moulding sands systems with organic binders require an in-depth approach to factors deciding on the matrixtechnological suitability as well as on their environmental impact. Into modern methods allowing for the better assessment of the matrixquality belongs the grain size analysis of the reclaimed material performed by means of the laser diffraction and also the estimation of the moulding sand gas evolution rate and identification of the emitted gases and their BTEX group gases content, since they are specially hazardous from the point of view of the Occupational Safety and Health.

  1. Investigations of the Quality of The Reclaim of Spent Moulding Sands with Organic Binders

    Directory of Open Access Journals (Sweden)

    Dańko R.

    2012-09-01

    Full Text Available Modern investigation methods and equipment for the quality estimation of the moulding sands matrices with organic binders, in their circulation process, are presented in the paper. These methods, utilising the special equipment combined with the authors investigation methods developed in the Faculty of Foundry Engineering, AGH the University of Science and Technology, allow for the better estimation of the matrix quality. Moulding sands systems with organic binders require an in-depth approach to factors deciding on the matrix technological suitability as well as on their environmental impact. Into modern methods allowing for the better assessment of the matrix quality belongs the grain size analysis of the reclaimed material performed by means of the laser diffraction and also the estimation of the moulding sand gas evolution rate and identification of the emitted gases and their BTEX group gases content, since they are specially hazardous from the point of view of the Occupational Safety and Health.

  2. A Twofold Comparison between Dual Cure Resin Modified Cement and Glass Ionomer Cement for Orthodontic Band Cementation.

    Science.gov (United States)

    Attar, Hanaa El; Elhiny, Omnia; Salem, Ghada; Abdelrahman, Ahmed; Attia, Mazen

    2016-12-15

    To test the solubility of dual cure resin modified resin cement in a food simulating solution and the shear bond strength compared to conventional Glass ionomer cement. The materials tested were self-adhesive dual cure resin modified cement and Glass Ionomer (GIC). Twenty Teflon moulds were divided into two groups of tens. The first group was injected and packed with the modified resin cement, the second group was packed with GIC. To test the solubility, each mould was weighed before and after being placed in an analytical reagent for 30 days. The solubility was measured as the difference between the initial and final drying mass. To measure the Shear bond strength, 20 freshly extracted wisdom teeth were equally divided into two groups and embedded in self-cure acrylic resin. Four mm sections of stainless steel bands were cemented to the exposed buccal surfaces of teeth under a constant load of 500 g. Shear bond strength was measured using a computer controlled materials testing machine and the load required to deband the samples was recorded in Newtons. GIC showed significantly higher mean weight loss and an insignificant lower Shear bond strength, compared to dual cure resin Cement. It was found that dual cure resin modified cement was less soluble than glass ionomer cement and of comparable bond strength rendering it more useful clinically for orthodontic band cementation.

  3. Effect of Process Parameters on Flow Length and Flash Formation in Injection Moulding of High Aspect Ratio Polymeric Micro Features

    Directory of Open Access Journals (Sweden)

    Abdelkhalik Eladl

    2018-01-01

    Full Text Available This paper reports an investigation of the effects of process parameters on the quality characteristics of polymeric parts produced by micro injection moulding (μIM with two different materials. Four injection moulding process parameters (injection velocity, holding pressure, melt temperature and mould temperature were investigated using Polypropylene (PP and Acrylonitrile Butadiene Styrene (ABS. Three key characteristics of the mouldings were evaluated with respect to process settings and the material employed: part mass, flow length and flash formation. The experimentation employs a test part with four micro fingers with different aspect ratios (from 21 up to 150 and was carried out according to the Design of Experiments (DOE statistical technique. The results show that holding pressure and injection velocity are the most influential parameters on part mass with a direct effect for both materials. Both parameters have a similar effect on flow length for both PP and ABS at all aspect ratios and have higher effects as the feature thickness decreased below 300 μm. The study shows that for the investigated materials the injection speed and packing pressure were the most influential parameters for increasing the amount of flash formation, with relative effects consistent for both materials. Higher melt and mould temperatures settings were less influential parameters for increasing the flash amount when moulding with both materials. Of the two investigated materials, PP was the one exhibiting more flash formation as compared with ABS, when corresponding injection moulding parameters settings for both materials were considered.

  4. Electric field modulation of magnetic anisotropy and microwave absorption properties in Fe50Ni50/Teflon composite films

    Directory of Open Access Journals (Sweden)

    Zhenjun Xia

    2016-05-01

    Full Text Available Fe50Ni50 nanoparticle films with the size about 6 nm were deposited by a high energetic cluster deposition source. An electric field of about 0 - 40 kV was applied on the sample platform when the films were prepared. The field assisted deposition technique can dramatically induce in-plane magnetic anisotropy. To probe the microwave absorption properties, the Fe50Ni50 nanoparticles were deliberately deposited on the dielectric Teflon sheet. Then the laminated Fe50Ni50/Teflon composites were used to do reflection loss scan. The results prove that the application of electric field is an effective avenue to improve the GHz microwave absorption performance of our magnetic nanoparticles films expressed by the movement of reflection loss peak to high GHz region for the composites.

  5. the suitability of lime rice husk ash cement as construction material

    African Journals Online (AJOL)

    NIJOTECH

    Enugu State University of Science and Technology, Enugu, Nigeria. ... It was therefore concluded that high percentage contents of silica, ... the Lime Rice Husk Ash cement when used as a construction material would depend ... thermal treatment of the silica in the husk .... test specimen in their moulds were stored in a.

  6. Respiratory health in children, and indoor exposure to (1,3)-beta-D-glucan, EPS mould components and endotoxin

    NARCIS (Netherlands)

    Tischer, C.; Gehring, U.; Chen, C-M; Kerkhof, M.; Koppelman, G.; Sausenthaler, S.; Herbarth, O.; Schaaf, B.; Lehmann, I.; Kraemer, U.; Berdel, D.; von Berg, A.; Bauer, C. P.; Koletzko, S.; Wichmann, H-E; Brunekreef, B.; Heinrich, J.

    For a long time, exposure to mould and dampness-derived microbial components was considered a risk factor for the development of respiratory diseases and symptoms. Some recent studies suggested that early childhood exposure to mould components, such as (1,3)-beta-D-glucan and extracellular

  7. Reengineering of Permanent Mould Casting with Lean Manufacturing Methods

    Directory of Open Access Journals (Sweden)

    R. Władysiak

    2007-07-01

    Full Text Available At the work were introduced main areas of production system project of casts produced in permanent moulds, that constitutes reengineering of conventional production system according to Lean Manufacturing (LM methods. New resolution of cooling of dies with water mist was shown to casting of car wheels made from aluminium alloys in low pressure casting process. It was implemented as a part of goal-oriented project in R.H. Alurad Sp.z o.o. in Gorzyce. Its using intensifies solidification and self-cooling of casts shortening the time of casting cycle by the 30%. It was described reorganizing casting stations into multi-machines cells production and the process of their fast tool’s exchange with applying the SMED method. A project of the system was described controlling the production of the foundry with the computer aided light Kanban system. A visualization of the process was shown the production of casts with use the value stream mapping method. They proved that applying casting new method in the technology and LM methods allowed to eliminate down-times, to reduce the level of stocks, to increase the productivity and the flow of the castings production.

  8. Immunological and biochemical characterization of extracellular polysaccharides of mucoralean moulds

    NARCIS (Netherlands)

    Ruiter, de G.A.

    1993-01-01

    In this thesis the characterization is described of the antigenic determinants (epitopes) of the extracellular polysaccharides (EPSs) from moulds belonging to the order of Mucorales. Detailed knowledge of the structure of these epitopes allows for further development of a new generation of

  9. Effect of increased manganese addition and mould type on the ...

    Indian Academy of Sciences (India)

    Administrator

    Effect of increased manganese addition and mould type on the slurry erosion characteristics of .... slurry erosion data in the form of bar diagrams for 5M24 and 10M24 ... being bigger in size with higher austenite retention and the attendant ...

  10. Microstructure formation via roll-to-roll UV embossing using a flexible mould made from a laminated polymer–copper film

    International Nuclear Information System (INIS)

    Zhong, Z W; Shan, X C

    2012-01-01

    Roll-to-roll large format UV embossing processes aim to revolutionize the manufacturing of functional films, with the ability to process a large area at one time, resulting in high throughput and cost reduction. In this paper, we present the experimental results obtained during the process development for roll-to-roll large format UV embossing. Flexible moulds were fabricated from a hybrid film substrate made of a liquid crystal polymer with clad copper foils laminated on both sides of it. The effective pattern area of the fabricated flexible mould was 400 mm × 300 mm with a minimal feature size of 50 µm. The results show that the roll-to-roll embossing processes are capable of producing micro-scale structures and functional devices over a large area at one time. Large-area roll-to-roll embossing was demonstrated by using the hybrid flexible mould, and micro-features and structures such as micro-channels and dot arrays were replicated on thermoplastic substrates. In addition to its ease and low cost in fabrication, the hybrid flexible moulds demonstrated to have acceptable fidelity and durability. The hybrid flexible mould is a novel solution for large-area embossing. (paper)

  11. Effect of biological sprays on the incidence of grey mould, fruit yield and fruit quality in organic strawberry production

    Directory of Open Access Journals (Sweden)

    S. PROKKOLA

    2008-12-01

    Full Text Available Plant diseases, especially grey mould (Botrytis cinerea, may cause severe losses in organic strawberry production. In a two-year period, 2001–2002, the effects of different biological sprays on grey mould, the fruit yield and fruit quality of organically grown strawberry ‘Jonsok’ were studied in field trials at MTT Agrifood Research Finland in Ruukki and Mikkeli. In Experiment 1 the biological sprays were seaweed, garlic and compost extracts, silicon and Trichoderma spp. on both trial sites. In Experiment 2, compost extract, Trichoderma spp. and Gliocladium catenulatum sprays were studied in Ruukki. The treatment time was chosen to control grey mould. The effect of different biological sprays on the incidence of grey mould and total and marketable yield was insignificant compared to the untreated control. In both years and in all trials the incidence of grey mould was low and rot occurred mainly in the latter part of the harvesting period, which may partly explain the small differences between treatments. Anyhow, despite of feasible biological control cultural control methods will be important to manage the fungus in organic strawberry production.;

  12. How to construct self/anti-self charge conjugate states?

    International Nuclear Information System (INIS)

    Dvoeglazov, V V

    2014-01-01

    We construct self/anti–self charge conjugate (Majorana–like) states for the (1/2, 0)⊕(0, 1/2) representation of the Lorentz group, and their analogs for higher spins within the quantum field theory. The problem of the basis rotations and that of the selection of phases in the Dirac–like and Majorana–like field operators are considered. The discrete symmetries properties (P, C, T) are studied. The corresponding dynamical equations are presented. In the (1/2, 0) ⊕ (0, 1/2) representation they obey the Dirac–like equation with eight components, which has been first introduced by Markov. Thus, the Fock space for corresponding quantum fields is doubled (as shown by Ziino). The particular attention has been paid to the questions of chirality and helicity (two concepts which are frequently confused in the literature) for Dirac and Majorana states. We further review several experimental consequences which follow from the previous works of M. Kirchbach et al. on neutrinoless double beta decay, and G. J. Ni et al. on meson lifetimes

  13. Attempts to use pulsed light as an emerging technology for inactivation of mould naturally present on rye

    Directory of Open Access Journals (Sweden)

    NICOLETA ARON MAFTEI

    2011-12-01

    Full Text Available Pulsed light technology was used to inactivate moulds, naturally present on rye. The experiments were performed on samples containing 3.5·104 CFU/g and 4.3·103 CFU/g. Treatments of different duration (5, 10, 15, 20, 30, and 40 pulses at intensity of 0.4 J·cm-2 per pulse were applied and mould inactivation was evaluated. Besides confirming the utilisation of pulsed light as decontamination method for cereals, this work contributes with new information regarding the effects of the spectral range of pulsed light, proving that the whole UV range of the spectrum accounts for the lethal effect against moulds. This research supports pulsed light as emerging technology in food preservation.

  14. Casting characteristics of Al-Mg alloy 535 cast in permanent moulds

    International Nuclear Information System (INIS)

    Fasoyinu, F.A.; Thomson, J.; Cousineau, D.; Castles, T.; Sahoo, M.

    2002-01-01

    Aluminum alloy 535 could be used for automotive and marine applications because of its good corrosion resistance against mild alkaline and salt spray exposure. The majority of components from this alloy are usually produced by sand casting because it is prone to hot shortness and has poor fluidity when poured in permanent moulds. In an attempt to improve its castability in permanent moulds, casting characteristics such as casting fluidity and hot tear resistance have been studied. In addition, the effectiveness of titanium, boron, scandium, zirconium and a combination of selected elements from this group as grain refiners were evaluated. It s shown that alloy 535 exhibits good casting fluidity when poured with adequate metal superheat and that there is significant improvement in hot tear resistance following grain refinement. (author)

  15. Experimental investigation of the factors influencing the polymer-polymer bond strength during two component injection moulding

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2007-01-01

    Two component injection moulding is a commercially important manufacturing process and a key technology for Moulded Interconnect Devices (MIDs). Many fascinating applications of two component or multi component polymer parts are restricted due to the weak interfacial adhesion of the polymers...... effectively control the adhesion between two polymers. The effects of environmental conditions on the bond strength after moulding are also investigated. The material selections and environmental conditions were chosen based on the suitability of MID production, but the results and discussion presented....... A thorough understanding of the factors that influence the bond strength of polymers is necessary for multi component polymer processing. This paper investigates the effects of the process and material parameters on the bond strength of two component polymer parts and identifies the factors which can...

  16. Individual and collective processes in the construction of the self: self-enhancement in the United States and self-criticism in Japan.

    Science.gov (United States)

    Kitayama, S; Markus, H R; Matsumoto, H; Norasakkunkit, V

    1997-06-01

    A collective constructionist theory of the self proposes that many psychological processes, including enhancement of the self (pervasive in the United States) and criticism and subsequent improvement of the self (widespread in Japan), result from and support the very ways in which social acts and situations are collectively defined and subjectively experienced in the respective cultural contexts. In support of the theory, 2 studies showed, first, that American situations are relatively conducive to self-enhancement and American people are relatively likely to engage in self-enhancement and, second, that Japanese situations are relatively conducive to self-criticism and Japanese people are relatively likely to engage in self-criticism. Implications are discussed for the collective construction of psychological processes implicated in the self and, more generally, for the mutual constitution of culture and the self.

  17. Iron Melt Flow in Thin Walled Sections Cast in Vertically Parted Green Sand Moulds

    DEFF Research Database (Denmark)

    Larsen, Per; Andersen, Uffa; Rasmussen, Niels

    Shortage of resources can be expected to become more wide spread in the future. Furthermore the focus on the environmental aspects will also be intensified. Today the clearest example is the large attention on the fuel consumption of cars. Many different approaches can be made to reduce the fuel ...... of gating systems investigated in this work, cannot be recommended for castings with high demands to the quality, as the variation in the filling patterns can be very large from mould to mould and hence the stability of the quality will be affected....

  18. Nano-in-Micro Self-Reporting Hydrogel Constructs.

    Science.gov (United States)

    Tirella, Annalisa; La Marca, Margherita; Brace, Leigh-Anne; Mattei, Giorgio; Aylott, Jonathan W; Ahluwalia, Arti

    2015-08-01

    Highly reproducible Nano-in-Micro constructs are fabricated to provide a well-defined and self-reporting biomimetic environment for hepatocytes. Based on a protein/hydrogel formulation with controlled shape, size and composition, the constructs enable efficient nutrient exchange and provide an adhesive 3D framework to cells. Co-encapsulation of hepatocytes and ratiometric optical nanosensors with pH sensitivity in the physiological range allows continuous monitoring of the microenvironment. The lobule-sized microbeads are fabricated using an automated droplet generator, Sphyga (Spherical Hydrogel Generator) combining alginate, collagen, decellularized hepatic tissue, pH-nanosensors and hepatocytes. The pH inside the Nano-in-Micro constructs is monitored during culture, while assaying media for hepatic function and vitality markers. Although the local pH changes by several units during bead fabrication, when encapsulated cells are most likely to undergo stress, it is stable and buffered by cell culture media thereafter. Albumin secretion and urea production are significantly higher in the microbeads compared with controls, indicating that the encapsulated Nano-in-Micro environment is conducive to enhanced hepatic function.

  19. Exploring Value-Added Options - Opportunities in Mouldings and Millwork

    Science.gov (United States)

    Bob Smith; Philip A. Araman

    1997-01-01

    The millwork industry, which includes manufacture of doors, windows, stair parts, blinds, mouldings, picture frame material, and assorted trim, can be a lucrative value-added opportunity for sawmills. Those entering the value-added millwork market often find that it is a great opportunity to generate greater profits from upper grades and utility species, such as yellow...

  20. Air Flow and Gassing Potential in Micro-injection Moulding

    DEFF Research Database (Denmark)

    Griffithsa, C.A.; Dimova, S.S.; Scholz, S.

    2011-01-01

    valuable information about the process dynamics and also about the filling of a cavity by a polymer melt. In this paper, a novel experimental set-up is proposed to monitor maximum air flow and air flow work as an integral of the air flow over time by employing a MEMS gas sensor mounted inside the mould...

  1. Inhibition of growth and mycotoxins formation in moulds by marine ...

    African Journals Online (AJOL)

    ... extracts (chloroform, hexane and methanol) had no activity on the microbial growth. Mycotoxins formation in Aspergillus flavus was inhibited by the ethanolic extracts at the concentration of 5%. Key Words: Algae, antimicrobial, minimal inhibitory concentration, moulds. African Journal of Biotechnology Vol.3(1) 2004: 71-75 ...

  2. On the epoxy moulding compound aging effect on package reliability

    NARCIS (Netherlands)

    Noijen, S.P.M.; Engelen, R.A.B.; Martens, J.; Opran, A.; Sluis, van der O.

    2009-01-01

    Most semi-conductor devices are encapsulated by epoxy moulding compound (EMC) material. Even after curing at the prescribed temperature and time in accordance with the supplier's curing specifications often the product is not yet 100% fully cured. As a consequence, the curing process of a product

  3. Effects of the inner mould material on the aluminium–316L stainless steel explosive clad pipe

    International Nuclear Information System (INIS)

    Guo, Xunzhong; Tao, Jie; Wang, Wentao; Li, Huaguan; Wang, Chen

    2013-01-01

    Highlights: ► Different mould materials were adopted to evaluate the effect of the constraint on the clad quality. ► The interface characteristics of clad pipe were analyzed for the different clad pipe. ► The clad pipes possess excellent bonding quality. - Abstract: The clad pipe played an important part in the pipeline system of the nuclear power industry. To prepare the clad pipe with even macrosize and excellent bonding quality, in this work, different mould materials were adopted to evaluate the effect of the constraint on the clad quality of the bimetal pipe prepared by explosive cladding. The experiment results indicated that, the dimension uniformity and bonding interface of clad pipe were poor by using low melting point alloy as mould material; the local bulge or the cracking of the clad pipe existed when the SiC powder was utilized. When the steel mould was adopted, the outer diameter of the clad pipe was uniform from head to tail. In addition, the metallurgical bonding was formed. Furthermore, the results of shear test, bending test and flattening test showed that the bonding quality was excellent. Therefore, the Al–316L SS clad pipe could endure the second plastic forming

  4. Dehydration of moulding sand in simulated casting process examined with neutron radiography

    Energy Technology Data Exchange (ETDEWEB)

    Schillinger, B., E-mail: Burkhard.Schillinger@frm2.tum.de [Technische Universitaet Muenchen, FRM II and Faculty for Physics E21, Lichtenbergstr. 1, 85748 Garching (Germany); Calzada, E. [Technische Universitaet Muenchen, FRM II and Faculty for Physics E21, Lichtenbergstr. 1, 85748 Garching (Germany); Eulenkamp, C.; Jordan, G.; Schmahl, W.W. [Ludwig-Maximilians-Universitaet Muenchen, Department fuer Geo- und Umweltwissenschaften, Sektion Kristallographie, Theresienstr. 41, 80333 Muenchen (Germany)

    2011-09-21

    Natural bentonites are an important material in the casting industry. Smectites as the main component of bentonites plasticize and stabilise sand moulds. Pore water as well as interlayer water within the smectites are lost as a function of time, location and temperature. Although rehydration of the smectites should be a reversible process, the industrially dehydrated smectites lose their capability to reabsorb water. This limits the number of possible process cycles of the mould material. A full understanding of the dehydration process would help to optimise the amount of fresh material to be added and thus save resources. A simulated metal casting was investigated with neutron radiography at the ANTARES neutron imaging facility of the FRM II reactor of Technische Universitaet Muenchen, Germany.

  5. Injection moulding of plastic parts with laser textured surfaces with optical applications

    Science.gov (United States)

    Pina-Estany, J.; García-Granada, A. A.; Corull-Massana, E.

    2018-05-01

    The purpose of this work is to manufacture micro and nanotextured surfaces on plastic injection moulds with the aim of replicating them and obtaining plastic parts with optical applications. Different patterns are manufactured with nanosecond and femtosecond lasers in order to obtain three different optical applications: (i) homogeneous light diffusion (ii) 1D light directionality and (iii) 2D light directionality. Induction heating is used in the injections in order to improve the textures degree of replication. The steel mould and the plastic parts are analyzed with a confocal/focus variation microscope and with a surface roughness tester. A mock-up and a luminance camera are used to evaluate the homogeneity and luminance of the homogeneous light diffusion application in comparison with the current industrial solutions.

  6. Two component injection moulding: an interface quality and bond strength dilemma

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2008-01-01

    on quality parameters of the two component parts. Most engineering applications of two component injection moulding calls for high bond strength between the two polymers, on the other hand a sharp and well-defined interface between the two polymers are required for applications like selective metallization...... of polymers, parts for micro applications and also for the aesthetic purpose of the final product. The investigation presented in this paper indicates a dilemma between obtaining reasonably good bond strength and at the same time keeping the interface quality suitable for applications. The required process...... conditions for a sharp and well-defined interface are exactly the opposite of what is congenial for higher bond strength. So in the production of two component injection moulded parts, there is a compromise to make between the interface quality and the bond strength of the two polymers. Also the injection...

  7. Modelling injection moulding machines for micro manufacture applications through functional analysis

    DEFF Research Database (Denmark)

    Fantoni, G.; Tosello, Guido; Gabelloni, D.

    2012-01-01

    The paper presents the analysis of an injection moulding machine using functional analysis to identify both its critical components and possible working problems when such a machine is employed for the production of polymer-based micro products. The step-by-step procedure starts from the study...... of the process phases of a machine and then it employs functional analysis to decompose the phases and attributes functions to part features. Part features are subsequently analyzed to understand the causal chains bringing either to the desired behaviour or to failures to avoid. The assessment of the design...... solution is finally performed by gathering quantitative data from experiments. The case study investigates the design motivations and functional drivers of a micro injection moulding machine. The analysis allows identifying the correlations between failures and advantages with the design of the machine...

  8. Thermoluminescent signal fading of encapsulated lif: Mg,Ti detectors in PTFE-Teflon registered trademark

    International Nuclear Information System (INIS)

    Sasho Nikolovski, Sasho; Nikolovska, Lidija; Velevska, Marija; Velev, Velko

    2010-01-01

    Fading is a process when the latent information of a detector is unintentionally lost mainly due to the thermal influence. Thermoluminescent (TL) detectors have different sensitivities as far as the fading effect. Encapsulated TL detectors mounted within shielded filter holders are used during the personal monitoring of occupationally exposed persons in R. Macedonia. PTFE-Teflon registered trademark polymer is an example of encapsulation material that has a temperature resistance and it allows the luminescence signal to pass through. Since the encapsulated TL detectors cannot be submitted to annealing treatment in an oven, another fading reduction method is needed. The TL evaluation method suggested in this work is based on a specific glow-curve region. Irradiations were conducted using 90Sr/90Y source. Post-irradiation fade investigations were conducted for evaluation periods that varied up to 4 months. Two areas of the TL glow-curve were selected with the WimRems software. They correspond to the high and the low fading emission peaks (the lower temperature peaks display a greater degree of thermal fading than the higher temperature peaks). Post-irradiation fade is a contributing factor that affects the response of a thermoluminescent (TL) phosphor as a function of time. PTFE - Polytetrafluoroethylene most well known by the DuPont brand name Teflon registered trademark. (Author)

  9. Development of Metal/Polymer Mixtures Dedicated to Macro and Micro powder Injection Moulding : Experiments and Simulations

    International Nuclear Information System (INIS)

    Quinard, C.; Barriere, T.; Gelin, J. C.; Song, J. P.; Cheng, Z. Q.; Liu, B. S.

    2007-01-01

    Important research tasks at ENSMM/LMA are concerned for the development of mixtures of fine powders associated to polymer binders dedicated to the powder injection moulding (PIM) and to the powder injection micro-moulding (μPIM) in accordance with many works already carried out with different feedstock suppliers dedicated to the macro-components. These research tasks are completed with the simulations of injection and sintering for solid state diffusion for to validate the mumerical models

  10. Presence of moulds and mycotoxins in spices

    Directory of Open Access Journals (Sweden)

    Karan Dragica D.

    2005-01-01

    Full Text Available In this paper there are presented the results of mycologic and mycotoxicologic analysis of seven spices which are being used for production of meat products. Using standard mycologic methods, in all the tested samples, we noticed a presence of moulds. By quality and quantity, most represented are genera: Aspergillus and Penicillium. With smaller occurrence there are presented genera: Rhizopus, Mucor, Paecylomyces and Absydia. Mycotoxins - ochratoxin, aflatoxins and zearalenon, are detected in samples of ground white pepper, ginger, cloves and ground caraway.

  11. Effect of process parameters on flow length and flash formation in injection moulding of high aspect ratio polymeric micro features

    DEFF Research Database (Denmark)

    Eladl, Abdelkhalik; Mostafa, Rania; Islam, Aminul

    2018-01-01

    This paper reports an investigation of the effects of process parameters on the quality characteristics of polymeric parts produced by micro injection moulding (µIM) with two different materials. Four injection moulding process parameters (injection velocity, holding pressure, melt temperature an...

  12. Wood working: planing and moulding in the last frontier

    Science.gov (United States)

    David Nicholls

    2007-01-01

    Planing and moulding is an important step in the value-added manufacture of wood products, and recent advances in Alaska have been noteworthy. Just a few years ago, most planing occurred on simple shop planers, producing lumber for retail sale or for wood working uses such as cabinet stock. Currently there are at least 26 planers and 13 moulders in-production at...

  13. Control of fusarium moulds and fumonisin B1 in grains by gamma Irradiation * Key words: Irradiated grains, Mycotoxins, Fusarium moulds, Fumonisins

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, N H; Shahin, A A.M.; Mahrous, S R [National Centre for Radiation Research and Technology, Nasr City, Cairo (Egypt); El-Far, F M [Animal Health Research Institute, Dokki, Giza (Egypt)

    2007-07-01

    The distribution of naturally occurring Fusarium moulds producing fumonisin B1 in seeds was determined. Fusarium infection of grain samples ranged from 10 to 60% and F.moniliforme was the predominant species. Fusarium counts in wheat grains were 8.1 x 10{sup 4} cfu/g, 6.3 x 10{sup 6} cfu/g in maize and 4.8 x 10{sup 3} cfu/g in barley. Wheat, maize and barley grains naturally contaminated with varying levels of fumonisin B1 (1.4 - 5.8, 8.0 - 13.8 and 0.1 - 0.5 {mu}g/g, respectively). Fusarium moniliforme and F. proliferatum were the major Fusarium contaminants producing fumonisin B1 . The effect of gamma irradiation on Fusarium moulds and levels of fumonisin B1 were also determined. The viable counts of Fusarium in grains was decreased by increasing the radiation dose levels, and the growth of Fusarium spp was inhibited at 4.0 KGy for barley and 6.0 KGy for wheat and maize. Application of gamma radiation dose at 5 KGy inactivated fumonisin B1 by 96.6, 87.1 and 100% for wheat, maize and barley, respectively, and a dose of 7 KGy was sufficient for complete destruction of fumonisin B1 in wheat and maize.

  14. Control of fusarium moulds and fumonisin B1 in grains by gamma Irradiation * Key words: Irradiated grains, Mycotoxins, Fusarium moulds, Fumonisins

    International Nuclear Information System (INIS)

    Aziz, N.H.; Shahin, A.A.M.; Mahrous, S.R.; El-Far, F.M.

    2007-01-01

    The distribution of naturally occurring Fusarium moulds producing fumonisin B1 in seeds was determined. Fusarium infection of grain samples ranged from 10 to 60% and F.moniliforme was the predominant species. Fusarium counts in wheat grains were 8.1 x 10 4 cfu/g, 6.3 x 10 6 cfu/g in maize and 4.8 x 10 3 cfu/g in barley. Wheat, maize and barley grains naturally contaminated with varying levels of fumonisin B1 (1.4 - 5.8, 8.0 - 13.8 and 0.1 - 0.5 μg/g, respectively). Fusarium moniliforme and F. proliferatum were the major Fusarium contaminants producing fumonisin B1 . The effect of gamma irradiation on Fusarium moulds and levels of fumonisin B1 were also determined. The viable counts of Fusarium in grains was decreased by increasing the radiation dose levels, and the growth of Fusarium spp was inhibited at 4.0 KGy for barley and 6.0 KGy for wheat and maize. Application of gamma radiation dose at 5 KGy inactivated fumonisin B1 by 96.6, 87.1 and 100% for wheat, maize and barley, respectively, and a dose of 7 KGy was sufficient for complete destruction of fumonisin B1 in wheat and maize

  15. Thermal analysis control of in-mould and ladle inoculated grey cast irons

    Directory of Open Access Journals (Sweden)

    Mihai Chisamera

    2009-05-01

    Full Text Available The effect of addition of 0.05wt.% to 0.25 wt.% Ca, Zr, Al-FeSi alloy on in-ladle and in-mould inoculation of grey cast irons was investigated. In the present paper, the conclusions drawn are based on thermal analysis. For the solidification pattern, some specific cooling curves characteristics, such as the degree of undercooling at the beginning of eutectic solidifi cation and at the end of solidifi cation, as well as the recalescence level, are identifi ed to be more infl uenced by the inoculation technique. The degree of eutectic undercooling of the electrically melted base iron having 0.025% S, 0.003% Al and 3.5% Ce is excessively high (39–40℃, generating a relatively high need for inoculation. Under these conditions, the in-mould inoculation has a more signifi cant effect compared to ladle inoculation, especially at lower inoculant usage (less than 0.20 wt.%. Generally, the efficiency of 0.05wt.%–0.15wt.% of alloy for in-mould inoculation is comparable to, or better than, that of 0.15wt.%–0.25wt.% addition in ladle inoculation procedures. In order to secure stable and controlled processes, representative thermal analysis parameters could be used, especially in thin wall grey iron castings production.

  16. Application of solid-phase microextraction with gas chromatography and mass spectrometry for the early detection of active moulds on historical woollen objects.

    Science.gov (United States)

    Sawoszczuk, Tomasz; Syguła-Cholewińska, Justyna; Del Hoyo-Meléndez, Julio M

    2017-02-01

    The goal of this work was to determine the microbial volatile organic compounds emitted by moulds growing on wool in search of particular volatiles mentioned in the literature as indicators of active mould growth. The keratinolytically active fungi were inoculated on two types of media: (1) samples of wool placed on broths, and (2) on broths containing amino acids that are elements of the structure of keratin. All samples were prepared inside 20 mL vials (closed system). In the first case (1) the broths did not contain any sources of organic carbon, nitrogen, or sulfur, i.e. wool was the only nutrient for the moulds. A third type of sample was historical wool prepared in a Petri dish without a broth and inoculated with a keratinolytically active mould (open system). The microbial volatiles emitted by moulds were sampled with the headspace solid-phase microextraction method. Volatiles extracted on solid-phase microextraction fibers were analyzed in a gas chromatography with mass spectrometry system. Qualitative and quantitative analyses of chromatograms were carried out in search of indicators of metabolic activity. The results showed that there are three groups of volatiles that can be used for the detection of active forms of moulds on woollen objects. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Mucoraceous moulds involved in the commercial fermentation of Sufu Pehtze

    NARCIS (Netherlands)

    Han, B.; Kuijpers, F.A.; Thanh, N.V.; Nout, M.J.R.

    2004-01-01

    Sufu is a fermented cheese-like soybean product in China and Vietnam, obtained by fungal solid-state fermentation of soybean curd (tofu), which results in moulded tofu or 'pehtze'. The final product sufu is obtained by maturing pehtze in a brine containing alcohol and salt during a period of several

  18. Yttria coating on quartz mould inner surface for fabrication of metal fuel slug using injection casting process

    International Nuclear Information System (INIS)

    Vinod, A.V.; Hemanth Kumar, S.; Manivannan, A.; Muralidaran, P.; Anthonysamy, S.; Sudha, R.

    2016-01-01

    Quartz moulds are used for casting metal alloy of U-Zr slugs by injection casting process. Ceramic (Y_2O_3) coating on inner surface of the quartz mould is provided to avoid silica contamination in the fuel slugs during casting. Experiments were carried out to standardise the coating process and optimising various parameters such as particle size of Y_2O_3, choice of suitable binder, method for application of coating, drying and sintering at high temperature to ensure uniformity and strength of coating. Required Coating thickness of ∼40 μm was achieved on a quartz mould of inner diameter of 4.98±0.01mm. Experimental procedure for coating on inner surface of the quartz tubes using yttrium oxide is described in this work. (author)

  19. Verification and optimization of HDR surface mould brachytherapy plans using GAFCHROMIC EBT2 film: the ideal geometric case

    International Nuclear Information System (INIS)

    Sobolewski, Matthew; Haque, Mamoon

    2011-01-01

    Full text: Surface mould brachytherapy is used to treat superficial cancers due to conformal dose distributions and rapid dose fall-off with depth. In this work, we determine the effect of varying catheter number and prescription distance on dose distributions for surface mould plans using radiochromic film. Eight surface mould plans were generated using PLATO BPS (Version 14.3.2). Measurements were taken with Gafchromic EBT2 film over depths of 5-30 mm with an Ir-192 HDR source. Films were scanned using an Epson Expression 10000 XL flatbed scanner and analysed using RIT 113 software. The EBT2 films showed good agreement with an average difference of 2.8% compared to the planning system. The dose gradient in the interval ranging ±5 mm from the prescription point showed an 80% increase from the plan with maximum catheters (II) to the minimum (3). The size and extent of local dose maxima increased when fewer catheters were used. Increasing prescription distance decreased the dose gradient with a 20% reduction in dose occurring 4 mm superficially to the prescription point when prescription distance increased from 5 to 20 mm. Gafchromic EBT2 was used successfully to evaluate surface mould brachytherapy plans and is a useful tool for dose verification checks. High dose regions ne,u' to the catheter plane can be reduced by using a larger number of catheters and the prescription distance should be adjusted as a function of treatment depth varied by mould thickness.

  20. 42 CFR 137.351 - Is a Self-Governance Tribe required to submit construction project progress and financial reports...

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Is a Self-Governance Tribe required to submit..., DEPARTMENT OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Construction Roles of Self-Governance Tribe in Establishing and Implementing Construction Project Agreements § 137.351 Is a Self-Governance Tribe required to...

  1. Modelling the effect of ethanol on growth rate of food spoilage moulds

    NARCIS (Netherlands)

    Dantigny, P.; Guilmart, A.; Radoi, F.; Bensoussan, M.; Zwietering, M.H.

    2005-01-01

    The effect of ethanol (E) on the radial growth rate (¿) of food spoilage moulds (Aspergillus candidus, Aspergillus flavus, Aspergillus niger, Cladosporium cladosporioides, Eurotium herbariorum, Mucor circinelloides, Mucor racemosus, Paecilomyces variotii, Penicillium chrysogenum, Penicillium

  2. PRELIMINARY STUDIES FOR PRODUCING CRUDE LIPASE FROM TEMPE’S MOULD CULTIVATED IN RICE-HUSK-BASED SOLID MEDIA

    OpenAIRE

    Bardant, Teuku Beuna; Sembiring, Kiky Corneliasari; Setiawan, Achmad Hanafi

    2010-01-01

    The goal of these preliminary studies is to support Indonesian program for increasing palm oil added value through independent production technology based on Indonesian natural resources. Various palm oil derivatives could be synthesized enzymatically using lipase from microbes that available in Indonesia. Tempe's mould is available in abundance in Indonesia and had already been proved for producing lipase. This paper provides information about producing crude lipase from Tempe's mould cultiv...

  3. Effect of steel and teflon infusion catheters on subcutaneous adipose tissue blood flow and infusion counter pressure in humans

    DEFF Research Database (Denmark)

    Højbjerre, Lise; Skov-Jensen, Camilla; Kaastrup, Peter

    2009-01-01

    BACKGROUND: Subcutaneous tissue is an important target for drug deposition or infusion. A local trauma may induce alterations in local microcirculation and diffusion barriers with consequences for drug bioavailability. We examined the influence of infusion catheters' wear time on local...... microcirculation and infusion counter pressure. METHODS: One steel catheter and one Teflon (Dupont, Wilmington, DE) catheter were inserted in subcutaneous, abdominal adipose tissue (SCAAT) in 10 healthy, lean men. The catheters were infused with isotonic saline at a rate of 10 microL/h for 48 h. Another steel...... catheter and a Teflon catheter were inserted contralateral to the previous catheters after 48 h. The infusion counter pressure was measured during a basal infusion rate followed by a bolus infusion. The measurements during a basal rate infusion were repeated after the bolus infusion. Adipose tissue blood...

  4. Viability tests of LIPI-MC mould collection in ampoule of L-drying preservation after one year of storage at 5ºC

    Directory of Open Access Journals (Sweden)

    MUHAMMAD ILYAS

    2007-01-01

    Full Text Available A study on viability test of several LIPI-MC mould isolates in ampoule of L-drying preservation after one year storage at 5º C had been conducted. In this study, cell survival level of 34 ampoules number from eight mould generas and 17 species had been counted. The objective of this study was to observe the survival or viability level of several mould isolates in ampoule L-drying preservation after one year storage at 5º C. The measurement of viability level was based on the average of colony forming unit density (CFU/ml. The result showed that there were seven mould isolates have hingh viabilitiy, 18 isolates have medium viabilitiy, two isolates have low viability, and five isolates have lost its viability.

  5. Utilizing of inner porous structure in injection moulds for application of special cooling method

    International Nuclear Information System (INIS)

    Seidl, M; Bobek, J; Habr, J; Běhálek, L; Šafka, J; Nováková, I

    2016-01-01

    The article is focused on impact evaluation of controlled inner structure of production tools and new cooling method on regulation of thermal processes for injection moulding technology. The mould inserts with porous structure were cooled by means of liquid CO 2 which is very progressive cooling method and enables very fast and intensive heat transfer among the plastic product, the production tool and cooling medium. The inserts were created using rapid prototype technology (DLSM) and they had a bi-component structure consisting of thin compact surface layer and defined porous inner structure of open cell character where liquid CO 2 was flowing through. This analyse includes the evaluation of cooling efficiency for different inner structures and different time profiles for dosing of liquid CO 2 into the porous structure. The thermal processes were monitored using thermocouples and IR thermal analyse of product surface and experimental device. Intensive heat removal influenced also the final structure and the shape and dimensional accuracy of the moulded parts that were made of semi-crystalline polymer. The range of final impacts of using intensive cooling method on the plastic parts was defined by DSC and dimensional analyses. (paper)

  6. Construct Validity of the Offer Self-Image Questionnaire and Its Relationship with Self-Esteem, Depression, and Ego Development

    Science.gov (United States)

    Lindfors, Kaj; Elovainio, Marko; Sinkkonen, Jari; Aalberg, Veikko; Vuorinen, Risto

    2005-01-01

    Construct validity of the Offer Self-Image Questionnaire (OSIQ) was studied in a sample of 194 normal Finnish adolescents from 14 to 16 years of age. Confirmatory factor analysis provided support for the hierarchical structure of adolescents' self-image with 5 lower-order factors loading on a single higher-order factor. Lower-order factors were…

  7. pH dependence of the kinetics of interfacial tension changes during protein adsorption from sessile droplets on FEP-Teflon

    NARCIS (Netherlands)

    VanderVegt, W; Norde, W; VanderMei, HC; Busscher, HJ

    Interfacial tension changes during protein adsorption at both the solid-liquid and the liquid-vapor interface were measured simultaneously by ADSA-P from sessile droplets of protein solutions on fluoroethylenepropylene-Teflon. Four globular proteins of similar size, viz. lysozyme, ribonuclease,

  8. Reclamation of alkaline spent moulding sands of organic and inorganic type and their mixtures

    Directory of Open Access Journals (Sweden)

    R. Dańko

    2011-10-01

    Full Text Available Introduction of modern moulding sands with organic and inorganic binders requires the reclamation treatments in order to be able to reuse the matrices of spent sands. The spent sands, depending on the applied binding agent, are characterised by various abilities of the matrix reclamation. The results of investigations of the reclamation of spent moulding sands with the Rudal binder and spent sands with the Rezolit binder in the system of uniform sands and of mixed ones, are presented in the paper. Investigations were performed by means of the special experimental stands designed and built in the AGH University of Science and Technology, AGH, in Krakow.

  9. Influence of the Mould Cooling Process on the Quality and Properties of Aluminium Alloy

    Directory of Open Access Journals (Sweden)

    Viktorie Weiss

    2014-12-01

    Full Text Available The article deals with the effect on the quality of casting moulds (metal, bentonite mixture on the structure of the alloy AlZn5,5MgCu and selected mechanical properties of the alloy. The effect of foundry moulds can significantly affect formation and range of crystal segregation and the subsequent thermal process of homogenization which has an influence on the final quality of the alloy. The research focuses on the formation and range of crystal segregation and its removal with homogenization annealing, in which the observed influence of individual factors influencing the diffusion process and quality of the aluminium alloy.

  10. Preparation of membranes by radiation grafting of acrylic acid onto Teflon-FEP film

    International Nuclear Information System (INIS)

    Gupta, B.D.

    1991-01-01

    The grafting of acrylic acid on radiation-peroxidised Teflon-FEP film provides an effective technique to prepare ion-exchange membranes. It was found that the grafted membranes have very high degree of swelling in aqueous KOH. The electric resistance of the film decreases considerably by grafting. An electric resistance of 0.2Ω cm 2 was obtained for a graft level beyond 58%. The hydrophilicity of the film was evaluated in terms of contact angle which shows a decreasing trend with the increasing degree of grafting. (author). 8 refs

  11. Investigation of beta ray attenuation in CaSO4:Dy(Tm)-teflon rods

    International Nuclear Information System (INIS)

    Szabo, P.P.

    1990-12-01

    Ultrathin discs were prepared from CaSO 4 :Dy(Tm)-teflon rods by cutting them with a microtom. The effect of cutting was studied experimentally. It was found that the cutting does not affect the TL signal of the discs, so one will be able to irradiate the rod and cut it afterwards which means that this method can be applied in the dosimetry of boundaries or to establish the energy of beta radiation. Depth dose distribution measurements were carried out by irradiating the rods with beta sources. (K.A.) 5 refs.; 6 figs

  12. Simulation of Air Entrapment and Resin Curing During Manufacturing of Composite Cab Front by Resin Transfer Moulding Process

    Directory of Open Access Journals (Sweden)

    Kuppusamy Raghu Raja Pandiyan

    2017-09-01

    Full Text Available Mould filling and subsequent curing are the significant processing stages involved in the production of a composite component through Resin Transfer Moulding (RTM fabrication technique. Dry spot formation and air entrapment during filling stage caused by improper design of filling conditions and locations that lead to undesired filling patterns resulting in defective RTM parts. Proper placement of inlet ports and exit vents as well as by adjustment of filling conditions can alleviate the problems during the mould filling stage. The temperature profile used to polymerize the resin must be carefully chosen to reduce the cure time. Instead of trial and error methods that are expensive, time consuming, and non-optimal, we propose a simulation-based optimization strategy for a composite cab front component to reduce the air entrapment and cure stage optimization. In order to be effective, the optimization strategy requires an accurate simulation of the process utilizing submodels to describe the raw material characteristics. Cure reaction kinetics and chemo-rheology were the submodels developed empirically for an unsaturated polyester resin using experimental data. The simulations were performed using commercial software PAM RTM 2008, developed by ESI Technologies. Simulation results show that the use of increase in injection pressure at the inlet filling conditions greatly reduce the air entrapped. For the cab front, the alteration of injection pressure with proper timing of vent opening reduced the air entrapped during mould filling stage. Similarly, the curing simulation results show that the use of higher mould temperatures effectively decreases the cure time as expected.

  13. Prediction of the epoxy moulding compound aging effect on package reliability

    NARCIS (Netherlands)

    Noijen, S.P.M.; Engelen, R.A.B.; Martens, J.; Opran, A.; Sluis, van der O.; Silfhout, van R.B.R.

    2010-01-01

    Most semi-conductor devices are encapsulated by epoxy moulding compound (EMC) material. Even after curing at the prescribed temperature and time in accordance with the supplier’s curing specifications often the product is not yet 100% fully cured. As a consequence, the curing process of a product

  14. Fuel poverty increases risk of mould contamination, regardless of adult risk perception & ventilation in social housing properties.

    Science.gov (United States)

    Sharpe, Richard A; Thornton, Christopher R; Nikolaou, Vasilis; Osborne, Nicholas J

    2015-06-01

    Fuel poverty affects 2.4 million UK homes leading to poor hygrothermal conditions and risk of mould and house dust mite contaminations, which in turn increases risk of asthma exacerbation. For the first time we assess how fuel poverty, occupants' risk perception and use of mechanical ventilation mediate the risk of mould contamination in social housing. Postal questionnaires were sent to 3867 social housing properties to collect adult risk perception, and demographic and environmental information on occupants. Participant details were linked to data pertaining to the individual properties. Multiple logistic regression was used to calculate odds ratios and confidence intervals while allowing for clustering of individuals coming from the same housing estate. We used Structured Equation Modelling and Goodness of Fit analysis in mediation analyses to examine the role of fuel poverty, risk perception, use of ventilation and energy efficiency. Eighteen percent of our target social housing populations (671 households) were included into our study. High risk perception (score of 8-10) was associated with reduced risk of mould contamination in the bedrooms of children (OR 0.5 95% CI; 0.3-0.9) and adults (OR 0.4 95% CI; 0.3-0.7). High risk perception of living with inadequate heating and ventilation reduced the risk of mould contamination (OR 0.5 95% CI; 0.3-0.8 and OR 0.5 95% CI; 0.3-0.7, respectively). Participants living with inadequate heating and not heating due to the cost of fuel had an increased risk of mould contamination (OR 3.4 95% CI; 2.0-5.8 and OR 2.2 95% CI; 1.5-3.2, respectively). Increased risk perception and use of extractor fans did not mediate the association between fuel poverty behaviours and increased risk of mould contamination. Fuel poverty behaviours increased the risk of mould contamination, which corresponds with existing literature. For the first time we used mediation analysis to assess how this association maybe modified by occupant behaviours

  15. Simulation on the Effect of Bottle Wall Thickness Distribution using Blow Moulding Technique

    International Nuclear Information System (INIS)

    Suraya, S; Azman, M D; Fatchurrohman, N; Jaafar, A A; Yusoff, A R

    2016-01-01

    The aims of this study are to assess the deformation behavior of a polymeric material during a blow moulding process. Transient computations of two dimensional model of a PP bottle were performed using ANSYS Polyflow computer code to predict the wall thickness distribution at four different parison's diameter; 8mm, 10mm, 18mm, and 20mm. Effects on the final wall thickness diameter and time step are studied. The simulated data shows that the inflation performance degrades with increasing parison diameter. It is concluded that the blow moulding process using 10mm parison successfully meet the product processing requirements. Factors that contribute to the variation in deformation behaviour of the plastic during the manufacturing process are discussed. (paper)

  16. Mould routine identification in the clinical laboratory by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Carole Cassagne

    Full Text Available BACKGROUND: MALDI-TOF MS recently emerged as a valuable identification tool for bacteria and yeasts and revolutionized the daily clinical laboratory routine. But it has not been established for routine mould identification. This study aimed to validate a standardized procedure for MALDI-TOF MS-based mould identification in clinical laboratory. MATERIALS AND METHODS: First, pre-extraction and extraction procedures were optimized. With this standardized procedure, a 143 mould strains reference spectra library was built. Then, the mould isolates cultured from sequential clinical samples were prospectively subjected to this MALDI-TOF MS based-identification assay. MALDI-TOF MS-based identification was considered correct if it was concordant with the phenotypic identification; otherwise, the gold standard was DNA sequence comparison-based identification. RESULTS: The optimized procedure comprised a culture on sabouraud-gentamicin-chloramphenicol agar followed by a chemical extraction of the fungal colonies with formic acid and acetonitril. The identification was done using a reference database built with references from at least four culture replicates. For five months, 197 clinical isolates were analyzed; 20 were excluded because they were not identified at the species level. MALDI-TOF MS-based approach correctly identified 87% (154/177 of the isolates analyzed in a routine clinical laboratory activity. It failed in 12% (21/177, whose species were not represented in the reference library. MALDI-TOF MS-based identification was correct in 154 out of the remaining 156 isolates. One Beauveria bassiana was not identified and one Rhizopus oryzae was misidentified as Mucor circinelloides. CONCLUSIONS: This work's seminal finding is that a standardized procedure can also be used for MALDI-TOF MS-based identification of a wide array of clinically relevant mould species. It thus makes it possible to identify moulds in the routine clinical laboratory setting

  17. Gating Systems for Sizeable Castings from Al Alloys Cast into Ceramic Moulds

    Directory of Open Access Journals (Sweden)

    I. Stachovec

    2012-04-01

    Full Text Available In contrast to casting to conventional non-reusable “sand” moulds, for which calculating technique for an optimum design of the gating system is comparatively well-developed, a trial-and-error method is applied mostly for casting to ceramic shell moulds made by the investment casting technology. A technologist selects from gating systems of several types (that are standardized by the foundry mostly on the basis of experience. However, this approach is not sustainable with ever growing demands on quality of castings and also the economy of their fabrication as well as with new types of complex sizeable castings introduced to the production gradually (by new customers from the aircraft industry above all any more. The simulation software may be used as a possible tool for making the process of optimising gating systems more effective.

  18. Quality control of injection moulded micro mechanical parts

    DEFF Research Database (Denmark)

    Gasparin, Stefania; Tosello, Guido; Hansen, Hans Nørgaard

    2009-01-01

    Quality control of micro components is an increasing challenge. Smaller mechanical parts are characterized by smaller tolerance to be verified. This paper focuses on the dimensional verification of micro injection moulded components selected from an industrial application. These parts are measured...... using an Optical Coordinate Measuring Machine (OCMM), which guarantees fast surface scans suitable for in line quality control. The uncertainty assessment of the measurements is calculated following the substitution method. To investigate the influence parameters in optical coordinate metrology two...

  19. Measurement of micro moulded parts by Computed Tomography and comparison to optical and tactile techniques

    DEFF Research Database (Denmark)

    Yagüe, J.A.; Tosello, Guido; Carmignato, S

    2011-01-01

    This paper focuses on dimensional verification of two micro-injection moulded components, selected from actual industrial productions, using CT metrological tools. In addition to CT scanning, also a tactile Coordinate Measuring Machine (CMM) with sub-micrometer uncertainty and an Optical Coordinate...... Measuring Machine (OCMM) allowing fast measurements suitable for in-line quality control were employed as validation instruments. The experimental work carried out and the analysis of the results provide valuable conclusions about the advantages and drawbacks of using CT metrology in comparison with CMM...... and OCMM when these techniques are employed for quality control of micro moulded parts....

  20. 42 CFR 137.379 - Do Davis-Bacon wage rates apply to construction projects performed by Self-Governance Tribes...

    Science.gov (United States)

    2010-10-01

    ... projects performed by Self-Governance Tribes using Federal funds? 137.379 Section 137.379 Public Health... HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Construction Other § 137.379 Do Davis-Bacon wage rates apply to construction projects performed by Self-Governance Tribes using Federal funds? Davis-Bacon Act...

  1. Formula of Moulding Sand, Bentonite and Portland Cement toImprove The Quality of Al-Si Cast Alloy

    OpenAIRE

    Andoko Andoko; Poppy Puspitasari; Avita Ayu Permanasari; Didin Zakaria Lubis

    2017-01-01

    A binder is any material used to strengthen the bonding of moulding sand grains. The primary function of the binder is to hold the moulding sand and other materialstogether to produce high-quality casts. In this study, there were four binder compositions being tested, i.e. 5% bentonite + 5% Portland cement, 4% bentonite + 6% Portland cement, 6% bentonite + 4% Portland cement, and 7% bentonite + 3% Portland cement. Each specimen was measured for its compressive strength, shear strength, tensil...

  2. PRELIMINARY STUDIES FOR PRODUCING CRUDE LIPASE FROM TEMPE’S MOULD CULTIVATED IN RICE-HUSK-BASED SOLID MEDIA

    Directory of Open Access Journals (Sweden)

    Teuku Beuna Bardant

    2010-06-01

    Full Text Available The goal of these preliminary studies is to support Indonesian program for increasing palm oil added value through independent production technology based on Indonesian natural resources. Various palm oil derivatives could be synthesized enzymatically using lipase from microbes that available in Indonesia. Tempe's mould is available in abundance in Indonesia and had already been proved for producing lipase. This paper provides information about producing crude lipase from Tempe's mould cultivated in rice-husk-based solid media using palm oil as carbon source. Observed variables include solid media composition, optimum fermentation time, extraction and enriching process of crude lipase. The crude lipase was analyzed its hydrolysis activity on coconut oil and palm oil. The result of these preliminary studies shows that this production process is a simple and tough process and very potential to be developed.   Keywords: lipase, Tempe's mould, palm oil, solid fermentation, rice husk

  3. Beyond self-esteem: influence of multiple motives on identity construction.

    Science.gov (United States)

    Vignoles, Vivian L; Regalia, Camillo; Manzi, Claudia; Golledge, Jen; Scabini, Eugenia

    2006-02-01

    Diverse theories suggest that people are motivated to maintain or enhance feelings of self-esteem, continuity, distinctiveness, belonging, efficacy, and meaning in their identities. Four studies tested the influence of these motives on identity construction, by using a multilevel regression design. Participants perceived as more central those identity elements that provided a greater sense of self-esteem, continuity, distinctiveness, and meaning; this was found for individual, relational, and group levels of identity, among various populations, and by using a prospective design. Motives for belonging and efficacy influenced identity definition indirectly through their direct influences on identity enactment and through their contributions to self-esteem. Participants were happiest about those identity elements that best satisfied motives for self-esteem and efficacy. These findings point to the need for an integrated theory of identity motivation. Copyright 2006 APA, all rights reserved.

  4. Effective ultraviolet irradiation of platelet concentrates in teflon bags

    International Nuclear Information System (INIS)

    Capon, S.M.; Sacher, R.A.; Deeg, H.J.

    1990-01-01

    Several plastic materials used in blood storage were evaluated for their ability to transmit ultraviolet B (UVB) light. A plastic bag manufactured from sheets of transparent Teflon efficiently (78-86%) transmitted UVB light and was employed in subsequent functional studies of lymphocytes and platelets exposed to UVB light while contained in these bags. In vitro experiments showed a UVB dose-dependent abrogation of lymphocyte responder and stimulator functions, with concurrent preservation of platelet aggregation responses. In a phase I pilot study, UVB-treated platelet concentrates were administered to four bone marrow transplant recipients. Adverse effects attributable to the transfusions were not observed, and patients showed clinically effective transfusion responses. No patient developed lymphocytotoxic HLA or platelet antibodies. These studies suggest that platelets can be effectively irradiated with UVB light in a closed system. However, numerous variables, including container material, volume and composition of contents, steady exposure versus agitation, and exact UV wavelength, must be considered

  5. Control of superficial mould in Provolone Valpadana cheese with environmental treatments. Preliminary trials

    International Nuclear Information System (INIS)

    Corradini, C.; Innocente, N.

    2001-01-01

    The possibility of relying on technological systems as an alternative to the use of additives in controlling the development of surface mould was evaluated on Valpadana Provolone cheese made on an industrial scale. Experimental tests were performed to evaluate the effect of sanitising the environment with ultraviolet radiation of the dryer area instead of the classic method of fumigation, as well as the effectiveness of direct treatment of the cheese with UV radiation, in order to prevent contamination with mould. Monitoring at the dairy, as well as analyses of the cheese at different stages in the maturation process, revealed that treating the rooms with UV radiation was just as effective as fumigation in preventing the development of mould. Likewise, the direct treatment of the cheese with UV proved to be a valid alternative physical method to the use of surface chemical additives, although it was difficult to radiate uniformly over the whole cheese owing to the presence of shaded areas at the cords. Lastly, it was considered that the application of suitable plastic coatings, instead of paraffin, applied after the rind has formed, could also be used as alternative antifungus additives. In this case, it was observed that the use of the Plasticoat polymer led to a decrease in the humidity of the curd with respect to paraffin treatment, also affecting the maturation process [it

  6. Perturbative construction of self-dual configurations on the torus

    International Nuclear Information System (INIS)

    Garcia Perez, M.; Gonzalez-Arroyo, A.; Pena, C.

    2000-01-01

    We develop a perturbative expansion which allows the construction of non-abelian self-dual SU(2) Yang-Mills field configurations on the four-dimensional torus with topological charge 1/2. The expansion is performed around the constant field strength abelian solutions found by 't Hooft. Next to leading order calculations are compared with numerical results obtained with lattice gauge theory techniques. (author)

  7. Comparison of the Emission of Aromatic Hydrocarbons from Moulding Sands with Furfural Resin with the Low Content of Furfuryl Alcohol and Different Activators

    Directory of Open Access Journals (Sweden)

    Żymankowska-Kumon S.

    2016-12-01

    Full Text Available No-bake process refers to the use of chemical binders to bond the moulding sand. Sand is moved to the mould fill station in preparation for filling of the mould. A mixer is used to blend the sand with the chemical binder and activator. As the sand exits the mixer, the binder begins the chemical process of hardening. This paper presents the results of decomposition of the moulding sands with modified urea-furfuryl resin (with the low content of furfuryl alcohol below 25 % and different activators: organic and inorganic on a quartz matrix, under semi-industrial conditions. Investigations of the gases emission in the test foundry plant were executed according to the method extended in the Faculty of Foundry Engineering (AGH University of Science and Technology. Article presents the results of the emitted chosen aromatic hydrocarbons and loss on ignition compared with the different activators used to harden this resin. On the bases of the data, it is possible to determine the content of the emitted dangerous substances from the moulding sand according to the content of loss on ignition.

  8. Delayed post-surgical sepsis from Teflon felt: The diagnostic value of CT scanning, and a reminder for theatre staff

    Directory of Open Access Journals (Sweden)

    D Emby

    2011-05-01

    Full Text Available We report on 2 patients with surgical site infections following the inadvertent use of Teflon felt for haemostasis in elective and emergency surgery. CT scanning was superior to plain radiography in demonstrating the foreign bodies to enable planning of further surgical treatment.

  9. Determination of Unit Pressure Force in Material Volume in the Course of Refractory Stamping Press Moulding

    Directory of Open Access Journals (Sweden)

    Orłowicz A.W.

    2016-06-01

    Full Text Available The paper presents results of assessment of the unit pressure force within the refractory material volume in the course press-moulding of stampings for refractory precast shapes. The force was evaluated with the use of physical simulation of deformation undergone by lead balls placed in the raw refractory mass subjected to pressing in a metal die. To determine the value of unit pressure force applied to the aggregate grains in the course of stamping press-moulding, physical model of deformation of a sphere induced by the uniaxial stress state was used.

  10. Comparison of conventional Injection Mould Inserts to Additively Manufactured Inserts using Life Cycle Assessment

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Bey, Niki; Mischkot, Michael

    2016-01-01

    Polymer Additive Manufacturing can be used to produce soft tooling inserts for injection moulding. Compared to conventional tooling, the energy and time consumption during production are significantly lower. As the life time of such inserts is significantly shorter than the life time of traditional...... of their potential environmental impact and yield throughout the development and pilot phase. Insert geometry is particularly advantageous for pilot production and small production sizes. In this research, Life Cycle Assessment is used to compare the environmental impact of soft tooling by Additive Manufacturing...... (using Digital Light Processing) and three traditional methods for the manufacture of inserts (milling of brass, steel, and aluminium) for injection moulds during the pre-production phase....

  11. Habituation in non-neural organisms: evidence from slime moulds.

    Science.gov (United States)

    Boisseau, Romain P; Vogel, David; Dussutour, Audrey

    2016-04-27

    Learning, defined as a change in behaviour evoked by experience, has hitherto been investigated almost exclusively in multicellular neural organisms. Evidence for learning in non-neural multicellular organisms is scant, and only a few unequivocal reports of learning have been described in single-celled organisms. Here we demonstrate habituation, an unmistakable form of learning, in the non-neural organism Physarum polycephalum In our experiment, using chemotaxis as the behavioural output and quinine or caffeine as the stimulus, we showed that P. polycephalum learnt to ignore quinine or caffeine when the stimuli were repeated, but responded again when the stimulus was withheld for a certain time. Our results meet the principle criteria that have been used to demonstrate habituation: responsiveness decline and spontaneous recovery. To distinguish habituation from sensory adaptation or motor fatigue, we also show stimulus specificity. Our results point to the diversity of organisms lacking neurons, which likely display a hitherto unrecognized capacity for learning, and suggest that slime moulds may be an ideal model system in which to investigate fundamental mechanisms underlying learning processes. Besides, documenting learning in non-neural organisms such as slime moulds is centrally important to a comprehensive, phylogenetic understanding of when and where in the tree of life the earliest manifestations of learning evolved. © 2016 The Author(s).

  12. Intracavitary mould brachytherapy in malignant tumors of the maxilla

    International Nuclear Information System (INIS)

    Rosenblatt, Edward; Blumenfeld, Israel; Cederbaum, Martin; Kuten, Abraham

    1996-01-01

    Purpose: To integrate brachytherapy in the combined modality management of malignant tumors of the maxilla, as a means of increasing the radiotherapy dose to the tumor bed while avoiding high doses to the orbital contents. Materials and methods: Following a partial or total maxillectomy, a duplication of the interim surgical obturator was created using a wash of vinyl polysiloxane. This mould was used as a carrier for afterloading nylon catheters through which 192-Iridium seed-ribbons were inserted. Following brachytherapy, selected patients also received external beam irradiation. Results and discussion: After a median follow-up of 36 months, 9 out of 11 patients are alive and disease-free; 1 developed a local recurrence and another relapsed at another site in the oral cavity. Transient grade 1 - 2 mucositis at the implant site was observed in all patients. The review of computer isodose distributions showed that the average dose received by the homolateral eyeball was 10% (range 9,2 - 10.0) of the prescribed surface dose to the surgical cavity. Conclusions: Brachytherapy can be integrated in the management of patients with malignant tumors of the maxilla in the form of a custom-made intracavitary mould carrying 192-Iridium sources. We found this technique particularly useful in cases with close or positive surgical margins

  13. New species of Simona Moulds, 2012 and Chelapsalta Moulds, 2012 cicadas (Cicadidae: Cicadettinae: Cicadettini) from Australia: comparative morphology, songs, behaviour and distributions.

    Science.gov (United States)

    Ewart, A; Popple, L W; Marshall, D C

    2015-08-20

    In 2012, Moulds established the morphologically similar cicada genera Simona and Chelapsalta, each with one Australian species (sancta Distant and puer Walker, respectively). In this paper, two new species are described within the genus Simona Moulds 2012, S. erema sp. nov. and S. retracta sp. nov., and one within the genus Chelapsalta Moulds 2012, C. myoporae sp. nov. The type species of Simona (female holotype), S. sancta (Distant, 1913), is redescribed based on a contemporary male, nominated a plesiotype, held in the Australian National Insect Collection. Melampsalta subgulosa Ashton 1914 is supported as a junior synonym of S. sancta. The species within the two genera of Simona and Chelapsalta are morphologically very similar. S. erema occurs widely through the arid regions of inland Australia, extending west from western Queensland through the Northern Territory, to central-western Western Australia, a linear distance of approximately 2200 km. S. retracta is known from a single semi-arid locality in southern inland Queensland. C. myoporae occurs widely through southeast, central and southwest Queensland, extending southwards into inland and western N.S.W. and southeastern South Australia. It tends to occur most commonly within vegetation associated with seasonal riverine floodplains, and in some areas of poorly drained and clay-rich soils. The calling songs of these three species, together with those of S. sancta and C. puer, are described. Detailed comparisons made of the songs of S. erema and C. myoporae, each from three widely separated locations, clearly exhibit structural consistency in their calling songs across their distributions. The Simona songs are complex and contain multiple elements; the species are very mobile and wary, and inhabit low dense shrubland. The songs of the two Chelapsalta species, both relatively sedentary in behaviour, in contrast consist of relatively uniform chirping and buzzing elements. It is suggested that, although the two

  14. Automated Layup of Sheet Prepregs on Complex Moulds

    OpenAIRE

    Elkington, Michael P; Ward, Carwyn; Potter, Kevin D

    2016-01-01

    A new two-stage method for the automated manufacture of high performance composites components is presented which aims to combine the capacity for forming complex shapes of Hand Layup with the speed of existing automated systems. In the first stage of the new process plies are formed into the approximate shape of the mould using a press mechanism. They are then passed onto a layup stage which uses multiple end effectors controlled by a single six axis robot to stick the plies down onto the mo...

  15. ASSESSMENT OF SURFACE FINISH AND DIMENSIONAL ACCURACY OF TOOLS MANUFACTURED BY METAL CASTING IN RAPID PROTOTYPING SAND MOULDS

    Directory of Open Access Journals (Sweden)

    Nyembwe, K.

    2012-11-01

    Full Text Available In this paper, an initial assessment of the quality parameters of the surface finish and dimensional accuracy of tools made by metal casting in rapid prototyping (RP sand moulds is undertaken. A case study from a local tool room, dealing with the manufacturing of an aluminium die for the lost wax process, is employed. Modern techniques, including surface roughness analysis and three dimensional scanning, are used to determine and understand how each manufacturing step influences the final quality of the cast tool. The best surface finish obtained for the cast die had arithmetic average roughness (Ra and mean average roughness (Rz respectively equal to 3.23m and 11.38m. In terms of dimensional accuracy, 82% of cast-die points coincided with the Computer Aided Design (CAD data, which is within the typical tolerances of sand cast products. The investigation shows that mould coating contributes slightly to the improvement of the cast tool surface finish. The study also found that the additive manufacturing of the sand mould was the chief factor responsible for the loss of dimensional accuracy. These findings indicate that machining will always be required to improve the surface finish and the dimensional accuracy of cast tools in RP sand moulds.

  16. Application of ATR-FTIR Spectroscopy to Compare the Cell Materials of Wood Decay Fungi with Wood Mould Fungi

    Directory of Open Access Journals (Sweden)

    Barun Shankar Gupta

    2015-01-01

    Full Text Available Wood fungi create vast damage among standing trees and all types of wood materials. The objectives of this study are to (a characterize the cell materials of two major wood decay fungi (Basidiomycota, namely, Trametes versicolor and Postia placenta, and (b compare the cell materials of decay fungi with four wood mould fungi (Ascomycota, namely, Aureobasidium pullulans, Alternaria alternata, Cladosporium cladosporioides, and Ulocladium atrum. Fourier transform infrared (FTIR spectroscopy is used to characterize the microbial cellular materials. The results showed that the IR bands for the fatty acid at ∼2900 cm−1 were different for the two-decay-fungi genre. Postia placenta shows more absorbance peaks at the fatty acid region. Band ratio indices for amide I and amide II from protein amino acids were higher for the mould fungi (Ascomycota than the decay fungi (Basidiomycota. Similarly, the band ratio index calculated for the protein end methyl group was found to be higher for the mould fungi than the decay fungi. Mould fungi along with the decay fungi demonstrated a positive correlation (R2=0.75 between amide I and amide II indices. The three-component multivariate, principal component analysis showed a strong correlation of amide and protein band indices.

  17. Characterization and analysis of sub-micron surface roughness of injection moulded microfluidic systems using White Light Interferometry

    DEFF Research Database (Denmark)

    Tosello, Guido; Marinello, Francesco; Hansen, Hans Nørgaard

    2009-01-01

    Surface topography is of great importance in polymer micro fluidics, therefore the replication capability of the process and the surface quality of the tool has to be suitably optimized. In this paper, optical profilometry (white light interferometry, WLI) is implemented for topographical...... characterization of polymer surfaces. In particular the study considers replication performance of injection moulding applied for the realization of microfluidic systems for blood analysis. Parts were produced by means of a series of statistically designed injection moulding experiments. Three process parameters...

  18. effect of aluminum dross and rice husk ash on thermal and moulding

    African Journals Online (AJOL)

    HOD

    mechanical properties in the cast component. This study ... microstructure and mechanical properties of as –cast thin wall ... sizes of 250-300 µm were used for moulding sand ..... [7] Ochulor, E. F; Amuda, M. O. H; Adeosun, S. O. and S. A.

  19. Indigenous technique of fabricating vaginal mould for vaginal reconstruction and uterine drainage in McIndoe vaginoplasty using 10 ml syringe

    Directory of Open Access Journals (Sweden)

    Brijesh Mishra

    2016-01-01

    Full Text Available Absence of vagina poses multitude of physical and psychosocial problems in woman's life. 10% of Mayer- Rokitansky-üster-Hauser (MRKH syndrome patients with high vaginal septum and vaginal atreisa has additional issue of draining uterine cavity. MC Indoe vaginoplasty is universally acceptable and widely practiced procedure for neocolposis reconstruction. Simultaneous reconstruction of vagina with simultaneous continued uterine drainage presents surgical challenge. We offer a simple solution of creating a vaginal mould using a 10 ml disposable syringe, which enables graft application of neovaginal cavity with simultaneous protected uterine drainage per vaginum. Total 10 patients were included in this study of which 4 needed uterine drainage procedure in addition to neovaginal creation. All the patients fared well, there were no problems regarding graft loss or vaginal mould extrusion etc. Fabrication of mould for graft enables easy dressing changes with out disturbing the skin graft. This innovation offers a simple easily reproducible and cheap way of fabricating vaginal mould for McIndoe vaginoplasty. It is especially useful for neovaginal graft application and simultaneous uterine drainage.

  20. Simulation of mould filling process for composite skeleton castings

    OpenAIRE

    M. Dziuba; M. Cholewa

    2008-01-01

    In this work authors showed selected results of simulation and experimental studies on temperature distribution during solidification of skeleton casting and mould filling process. The aim of conducted simulations was the choice of thermal and geometrical parameters for the needs of designed calculations of the skeleton castings and the estimation of the guidelines for the technology of manufacturing. The subject of numerical simulation was the analysis of ability of filling the channels of c...

  1. Decoring Behaviour of Chosen Moulding Materials with Alkali Silicate Based Inorganic Binders

    Directory of Open Access Journals (Sweden)

    Conev M.

    2017-06-01

    Full Text Available This paper contains basic information about new processes for cores for cylinder heads production with alkali silicate based inorganic binders. Inorganic binders are coming back to the foreground due to their ecologically friendly nature and new technologies for cores production and new binder systems were developed. Basically these binder systems are modified alkali silicates and therefore they carry some well-known unfavourable properties with their usage. To compensate these disadvantages, the binder systems are working with additives which are most often in powder form and are added in the moulding material. This paper deals with decoring behaviour of different moulding sands as well as the influence of chosen additives on knock-out properties in laboratory terms. For this purpose, specific methods of specimen production are described. Developed methods are then used to compare decoring behaviour of chosen sands and binder systems.

  2. Inhibition of grey mould in vitro and in vivo with essential oil of fennel (Foeniculum vulgare L.

    Directory of Open Access Journals (Sweden)

    Samane MOHAMMADI

    2013-03-01

    Full Text Available The aim of the study was to determine the antifungal effects of the fennel essential oil against fungal pathogen Botrytis cinerea the causal agent of grey mould disease of tomato fruit under in vitro and in vivo conditions. Treatments consisted of five concentrations (0, 200, 400, 600 and 800 lL-1.The fennel oil had a remarkable effect on spore germination of grey mould. The growth of grey mould was completely inhibited by fennel oil at 600 and 800 lL-1.The results in vivo showed that fennel oil increased the shelf life and decreased decay rate of tomato fruits. Also, fennel essential oil positively affected on postharvest quality factors. Treated fruits with fennel oil had significantly higher titrable acidity, total soluble solids, ascorbic acid, and lycopene and -carotene content comparison to control. Thus, these results showed that fennel essential oil has impact on postharvest decay and fruit quality of tomato.

  3. Mass transfer in fuel cells. [electron microscopy of components, thermal decomposition of Teflon, water transport, and surface tension of KOH solutions

    Science.gov (United States)

    Walker, R. D., Jr.

    1973-01-01

    Results of experiments on electron microscopy of fuel cell components, thermal decomposition of Teflon by thermogravimetry, surface area and pore size distribution measurements, water transport in fuel cells, and surface tension of KOH solutions are described.

  4. Casting Ductile Iron in Layer Moulds Made from Ecological Sands

    Directory of Open Access Journals (Sweden)

    M. Rączka

    2012-09-01

    Full Text Available The article contains the results of tests performed under the target project in Hardtop Foundry Charsznica.The objective of the tests and studies was to develop a technology of making high-quality ductile iron castings, combined witheffective means of environmental protection. The studies presented in this article related to castings weighing from 1 to 300 kg made from ductile iron of grades 400-15 and 500-7, using two-layer moulds, where the facing and core sand was the sand with an alkaline organic binder, while backing sand was the sand with an inorganic geopolymer binder.A simplified method of sand reclamation was applied with possible reuse of the reclaim as an addition to the backing sand. The castiron spheroidising treatment and inoculation were selected taking into account the specific conditions of Hardtop Foundry. A pilot batch of castings was made, testing the gating and feeding systems and using exothermic sleeves on risers. The study confirmed the validity of the adopted concept of making ductile iron castings in layer moulds, while maintaining the content of sand with an organic binder at a level of maximum 15%.

  5. Rheological parameters used for deliberate deformation of a flexible mould after casting

    NARCIS (Netherlands)

    Grunewald, S.; Schipper, H.R.; Raghunath, P.

    2013-01-01

    This paper describes how curved precast concrete elements can be manufactured in an open and reusable flexible mould. The proposed method reduces formwork costs of architectural freeform elements in concrete. First, the method is described briefly, then a series of tests are discussed, demonstrating

  6. From the patient to the clinical mycology laboratory: how can we optimise microscopy and culture methods for mould identification?

    Science.gov (United States)

    Vyzantiadis, Timoleon-Achilleas A; Johnson, Elizabeth M; Kibbler, Christopher C

    2012-06-01

    The identification of fungi relies mainly on morphological criteria. However, there is a need for robust and definitive phenotypic identification procedures in order to evaluate continuously evolving molecular methods. For the future, there is an emerging consensus that a combined (phenotypic and molecular) approach is more powerful for fungal identification, especially for moulds. Most of the procedures used for phenotypic identification are based on experience rather than comparative studies of effectiveness or performance and there is a need for standardisation among mycology laboratories. This review summarises and evaluates the evidence for the major existing phenotypic identification procedures for the predominant causes of opportunistic mould infection. We have concentrated mainly on Aspergillus, Fusarium and mucoraceous mould species, as these are the most important clinically and the ones for which there are the most molecular taxonomic data.

  7. Fabrication of carbon-polymer composite bipolar plates for polymer electrolyte membrane fuel cells by compression moulding

    International Nuclear Information System (INIS)

    Raza, M.A.; Ahmed, R.; Saleem, A.; Din, R.U.

    2009-01-01

    Fuel cells are considered as one of the most important technologies to address the future energy and environmental pollution problems. These are the most promising power sources for road transportation and portable devices. A fuel cell is an electrochemical device that converts chemical energy into electrical energy. A fuel cell stack consists of bipolar plates and membrane electrode assemblies (MEA). The bipolar plate is by weight, volume and cost one of the most significant components of a fuel cell stack. Major functions of bipolar plates are to separate oxidant and fuel gas, provide flow channels, conduct electricity and provide heat transfer. Bipolar plates can be made from various materials including graphite, metals, carbon / carbon and carbon/ polymer composites. Materials for carbon-polymer composites are relatively inexpensive, less corrosive, strong and channels can be formed by means of a moulding process. Carbon-polymer composites are of two type i.e; thermosetting and thermoplastic. For thermosetting composite a bulk molding compound (BMC) was prepared by adding graphite, vinyl ester resin, methyl ethyl ketone peroxide and cobalt naphthalate. The BMC was thoroughly mixed, poured into a die mould of a bipolar plate with channels and hot pressed at a specific temperature and pressure. A bipolar plate was formed according to the die mould. Design of the mould is also discussed. Conducting polymers were also added to BMC to increase the conductivity of bipolar plates. Particle size of the graphite has also a significant effect on the conductivity of the bipolar plates. Thermoplastic composites were also prepared using polypropylene and graphite.

  8. Investigation of over-moulded hybrid metal/polymer devices

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Tang, Peter Torben

    2006-01-01

    principles, in-process manufacturing technologies, as well as testing methodologies have to be established in order to be able to develop such integrated devices. In this paper an investigation of the bonding between miniaturized metal insert and a polymer matrix is presented. A special demonstrator...... was designed and manufactured by over-moulding and hot-embossing. The bonding strength between the insert and the plastic part was tested by means of a tensile test. A variety of parameters was studied in order to investigate their influence on the bonding: different polymeric and metallic materials, insert...

  9. Comparison of custom-moulded ankle orthosis with hinged joints and off-the-shelf ankle braces in preventing ankle sprain in lateral cutting movements.

    Science.gov (United States)

    Lee, Winson C C; Kobayashi, Toshiki; Choy, Barton T S; Leung, Aaron K L

    2012-06-01

    A custom moulded ankle orthosis with hinged joints potentially offers a better control over the subtalar joint and the ankle joint during lateral cutting movements, due to total contact design and increase in material strength. To test the above hypothesis by comparing it to three other available orthoses. Repeated measures. Eight subjects with a history of ankle sprains (Grade 2), and 11 subjects without such history performed lateral cutting movements in four test conditions: 1) non-orthotic, 2) custom-moulded ankle orthosis with hinges, 3) Sport-Stirrup, and 4) elastic ankle sleeve with plastic support. A VICON motion analysis system was used to study the motions at the ankle and subtalar joints. The custom-moulded ankle orthosis significantly lowered the inversion angle at initial contact (p = 0.006) and the peak inversion angle (p = 0.000) during lateral cutting movements in comparison to non-orthotic condition, while the other two orthoses did not. The three orthoses did not affect the plantarflexion motions, which had been suggested by previous studies to be important in shock wave attenuation. The custom-moulded ankle orthosis with hinges could better control inversion and thus expected to better prevent ankle sprain in lateral cutting movements. Custom-moulded ankle orthoses are not commonly used in preventing ankle sprains. This study raises the awareness of the use of custom-moulded ankle orthoses which are expected to better prevent ankle sprains.

  10. Mould growth prediction by computational simulation on historic buildings

    OpenAIRE

    Krus, M.; Kilian, R.; Sedlbauer, K.

    2007-01-01

    Historical buildings are often renovated with a high expenditure of time and money without investigating and considering the causes of the damages. In many cases historic buildings can only be maintained by changing their usage. This change of use may influence the interior climate enormously. To assess the effect on the risk of mould growth on building parts or historic monuments a predictive model has been developed recently, describing the hygrothermal behaviour of the spore. It allows for...

  11. Thermoset polymers chemo-rheology dedicated to reactive rotational moulding (RRM) understanding and control

    International Nuclear Information System (INIS)

    Viale, J.

    2009-12-01

    This study comes within the scope of New Technology for Energy, particularly for high pressure hydrogen storage. Reactive Rotational Moulding has been identified as an adapted process for hydrogen-tight liners manufacturing. Thus the Reactive Rotational Moulding process has been studied in order to find theoretical tools dedicated to the understanding of such a reactive forming process. Chemical kinetics of four polyurethanes and poly-epoxides reactive systems have been determined on classical isothermal conditions and original aniso-thermal conditions i.e. on temperature ramps. Aniso-thermal conditions have been selected because they corresponds better to real process conditions. Rheological behaviour have also been characterized on two different approaches, an isothermal one and on temperature ramps. In particular, viscosity have been described as a function of heating rate. These physical and chemical results have been compiled in an original state diagram in order to show material properties evolution in a time-temperature space. The whole ex situ characterizations are then managed to described the behavior of the different formulations during the rotational moulding. Moreover they allow to form specific materials and so to widen the range of material to thermoset polymers. Finally, in order to correlate theoretical deduction to real reactive systems evolution, the elaboration of innovating monitoring tool based on ultrasonic analysis has been studied. To begin, polymerization monitoring criteria have been identified and then specific techniques have been set to monitor these criteria in real forming process. (author)

  12. Integrating measuring uncertainty of tactile and optical coordinate measuring machines in the process capability assessment of micro injection moulding

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Gasparin, Stefania

    2010-01-01

    Process capability of micro injection moulding was investigated in this paper by calculating the Cp and Cpk statistics. Uncertainty of both optical and tactile measuring systems employed in the quality control of micro injection moulded products was assessed and compared with the specified...... tolerances. Limits in terms of manufacturing process capability as well as of suitability of such measuring systems when employed for micro production inspection were quantitatively determined....

  13. Numerical modelling of thermal and fluid flow phenomena in the mould channel

    Directory of Open Access Journals (Sweden)

    L. Sowa

    2007-12-01

    Full Text Available In the paper, a mathematical and a numerical model of the solidification of a cylindrical slender shaped casting, which take into account the process of filling the mould cavity with molten metal, has been proposed. Pressure and velocity fields were obtained by solving the momentum equations and the continuity equation, while the thermal fields were obtained by solving the heat conduction equation containing the convection term. Next, the numerical analysis of the solidification process of metals alloy in a cylindrical mould channel has been made. In the model one takes into account interdependence the heat transfer and fluid flow phenomena. Coupling of the thermal and fluid flow phenomena has been taken into consideration by the changes of the fluidity function and thermophysical parameters of alloy with respect to the temperature. The influence of the pressure and the temperature of metal pouring on the solid phase growth kinetics were estimated. The problem has been solved by the finite element method.

  14. Weld line optimization on thermoplastic elastomer micro injection moulded components using 3D focus variation optical microscopy

    DEFF Research Database (Denmark)

    Hasnaes, F.B.; Elsborg, R.; Tosello, G.

    2015-01-01

    The presented study investigates weld line depth development across a micro suspension ring. A focus variation microscope was used to obtain 3D images of the weld line area. Suspension rings produced with different micro injection moulding process parameters were examined to identify the correlat......The presented study investigates weld line depth development across a micro suspension ring. A focus variation microscope was used to obtain 3D images of the weld line area. Suspension rings produced with different micro injection moulding process parameters were examined to identify...

  15. Influence of the Training Set Value on the Quality of the Neural Network to Identify Selected Moulding Sand Properties

    Directory of Open Access Journals (Sweden)

    Jakubski J.

    2013-06-01

    Full Text Available Artificial neural networks are one of the modern methods of the production optimisation. An attempt to apply neural networks for controlling the quality of bentonite moulding sands is presented in this paper. This is the assessment method of sands suitability by means of detecting correlations between their individual parameters. This paper presents the next part of the study on usefulness of artificial neural networks to support rebonding of green moulding sand, using chosen properties of moulding sands, which can be determined fast. The effect of changes in the training set quantity on the quality of the network is presented in this article. It has been shown that a small change in the data set would change the quality of the network, and may also make it necessary to change the type of network in order to obtain good results.

  16. Numerical modeling of the conduction and radiation heating in precision glass moulding

    DEFF Research Database (Denmark)

    Sarhadi, Ali; Hattel, Jesper Henri; Hansen, Hans Nørgaard

    2012-01-01

    wafer, heating can be performed by either conduction or radiation. The numerical simulation of these two heating mechanisms in the wafer based glass moulding process is the topic of the present paper. First, the transient heating of the glass wafer is simulated by the FEM software ABAQUS. Temperature...

  17. Simulation and Validation of Injection-Compression Filling Stage of Liquid Moulding with Fast Curing Resins

    Science.gov (United States)

    Martin, Ffion A.; Warrior, Nicholas A.; Simacek, Pavel; Advani, Suresh; Hughes, Adrian; Darlington, Roger; Senan, Eissa

    2018-03-01

    Very short manufacture cycle times are required if continuous carbon fibre and epoxy composite components are to be economically viable solutions for high volume composite production for the automotive industry. Here, a manufacturing process variant of resin transfer moulding (RTM), targets a reduction of in-mould manufacture time by reducing the time to inject and cure components. The process involves two stages; resin injection followed by compression. A flow simulation methodology using an RTM solver for the process has been developed. This paper compares the simulation prediction to experiments performed using industrial equipment. The issues encountered during the manufacturing are included in the simulation and their sensitivity to the process is explored.

  18. A 2D modeling approach for fluid propagation during FE-forming simulation of continuously reinforced composites in wet compression moulding

    Science.gov (United States)

    Poppe, Christian; Dörr, Dominik; Henning, Frank; Kärger, Luise

    2018-05-01

    Wet compression moulding (WCM) provides large-scale production potential for continuously fiber reinforced components as a promising alternative to resin transfer moulding (RTM). Lower cycle times are possible due to parallelization of the process steps draping, infiltration and curing during moulding (viscous draping). Experimental and theoretical investigations indicate a strong mutual dependency between the physical mechanisms, which occur during draping and mould filling (fluid-structure-interaction). Thus, key process parameters, like fiber orientation, fiber volume fraction, cavity pressure and the amount and viscosity of the resin are physically coupled. To enable time and cost efficient product and process development throughout all design stages, accurate process simulation tools are desirable. Separated draping and mould filling simulation models, as appropriate for the sequential RTM-process, cannot be applied for the WCM process due to the above outlined physical couplings. Within this study, a two-dimensional Darcy-Propagation-Element (DPE-2D) based on a finite element formulation with additional control volumes (FE/CV) is presented, verified and applied to forming simulation of a generic geometry, as a first step towards a fluid-structure-interaction model taking into account simultaneous resin infiltration and draping. The model is implemented in the commercial FE-Solver Abaqus by means of several user subroutines considering simultaneous draping and 2D-infiltration mechanisms. Darcy's equation is solved with respect to a local fiber orientation. Furthermore, the material model can access the local fluid domain properties to update the mechanical forming material parameter, which enables further investigations on the coupled physical mechanisms.

  19. Chinese EFL teachers' knowledge of basic language constructs and their self-perceived teaching abilities.

    Science.gov (United States)

    Zhao, Jing; Joshi, R Malatesha; Dixon, L Quentin; Huang, Liyan

    2016-04-01

    The present study examined the knowledge and skills of basic language constructs among elementary school teachers who were teaching English as a Foreign Language (EFL) in China. Six hundred and thirty in-service teachers completed the adapted Reading Teacher Knowledge Survey. Survey results showed that English teachers' self-perceived ability to teach vocabulary was the highest and self-perceived ability to teach reading to struggling readers was the lowest. Morphological knowledge was positively correlated with teachers' self-perceived teaching abilities, and it contributed unique variance even after controlling for the effects of ultimate educational attainment and years of teaching. Findings suggest that elementary school EFL teachers in China, on average, were able to display implicit skills related to certain basic language constructs, but less able to demonstrate explicit knowledge of other skills, especially sub-lexical units (e.g., phonemic awareness and morphemes). The high self-perceived ability of teaching vocabulary and high scores on syllable counting reflected the focus on larger units in the English reading curriculum.

  20. MAIN PROBLEMS OF MOULDING OF SILUMINS. WAYS OF SOLUTION

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2016-01-01

    Full Text Available The main problems of silumin’ moulding are connected with insufficient modifying of casting structure, their considerable inclination to gas porosity, difficult to remove nonmetallic inclusions and these features are shown in the article. Protection of liquid silumin from influence of the air atmosphere; use of crucibles from aluminum oxide; refinement of fusion from nonmetallic inclusions and application of the accelerated hydrogen hardening of castings were used to solve these problems, as it is shown in the article.

  1. Influence of sand base preparation on properties of chromite moulding sands with sodium silicate hardened with selected methods

    Directory of Open Access Journals (Sweden)

    Stachowicz M.

    2017-03-01

    Full Text Available The paper presents a research on the relation between thermal preparation of chromite sand base of moulding sands containing sodium silicate, hardened with selected physical and chemical methods, and structure of the created bonding bridges. Test specimens were prepared of chromite sand - fresh or baked at 950°C for 10 or 24 hours - mixed with 0.5 wt.% of the selected non-modified inorganic binder and, after forming, were hardened with CO2 or liquid esters, dried traditionally or heated with microwaves at 2.45 GHz. It was shown on the grounds of SEM observations that the time of baking the base sand and the hardening method significantly affect structure of the bonding bridges and are correlated with mechanical properties of the moulding sands. It was found that hardening chromite-based moulding mixtures with physical methods is much more favourable than hardening with chemical methods, guaranteeing also more than ten times higher mechanical properties.

  2. Numerical Simulation of Steady State Conduction Heat Transfer During the Solidification of Aluminum Casting in Green Sand Mould

    Directory of Open Access Journals (Sweden)

    Victor ANJO

    2012-08-01

    Full Text Available The solidification of molten metal during the casting process involves heat transfer from the molten metal to the mould, then to the atmosphere. The mechanical properties and grain size of metals are determined by the heat transfer process during solidification. The aim of this study is to numerically stimulate the steady conduction heat transfer during the solidification of aluminum in green sand mould using finite difference analysis 2D. The properties of materials used are industrial AI 50/60 AFS green sand mould, pure aluminum and MATLAB 7.0.1. for the numerical simulation. The method includes; the finite difference analysis of the heat conduction equation in steady (Laplace’s and transient states and using MATLAB to numerically stimulate the thermal flow and cooling curve. The results obtained are: the steady state thermal flow in 2D and transient state cooling curve of casting. The results obtain were consider relevant in the control of the grain size and mechanical properties of the casting.

  3. Investigations of physicochemical properties of dusts generated in mechanical reclamation process of spent moulding sands with alkaline resins

    Directory of Open Access Journals (Sweden)

    R. Dańko

    2014-03-01

    Full Text Available Mechanical reclamation processes of spent moulding sands generate large amounts of post-reclamation dusts mainly containing rubbed spent binding agents and quartz dusts. The amount of post-reclamation dusts, depending in the reclamation system efficiency and the reclaim dedusting system, can reach 5%-10% in relation to the total reclaimed spent moulding sand. The proper utilization of such material is a big problem facing foundries these days. This study presents the results of investigations of physicochemical properties of post- reclamation dusts. All tested dusts originated from various Polish cast steel plants applying the mechanical reclamation process of moulding sands with alkaline resins, obtained from different producers. Different dusts, delivered from foundries, were tested to determine their chemical composition, granular characterization, physicochemical and energetic properties. Presented results confirmed assumptions that it is possible to utilize dusts generated during mechanical reclamation of used sands with organic resins as a source of energy.

  4. Effect of three mycotoxin adsorbents on growth performance, nutrient retention and meat quality in broilers fed on mould-contaminated feed.

    Science.gov (United States)

    Liu, Y L; Meng, G Q; Wang, H R; Zhu, H L; Hou, Y Q; Wang, W J; Ding, B Y

    2011-04-01

    1. A study was conducted to investigate the effects of an esterified glucomannan (EGM), a hydrated sodium calcium aluminosilicate (HSCAS) and a compound mycotoxin adsorbent (CMA) on performance, nutrient retention and meat quality in broilers fed on mould-contaminated feed. Mould-contaminated diets were prepared by replacing half of the non-contaminated maize in the basal diets with mould-contaminated maize, which contained 450·6 µg/kg of aflatoxin B1, 68·4 µg/kg of ochratoxin A and 320·5 µg/kg of T-2 toxin. 2. The mould-contaminated diet significantly decreased body weight gain (BWG) between 10 and 21 d, feed intake (FI) between 35 and 42 d, the apparent retention of crude lipid and phosphorus, and the lightness (L*) value of breast and thigh muscle. It also significantly increased the redness (a*) and yellowness (b*) value in breast muscle and the b* value in thigh muscle. 3. The addition of 0·2% HSCAS significantly increased FI between 35 and 42 d and the apparent retention of phosphorus. Supplementation with 0·1% CMA in the contaminated diet significantly improved BWG from 10 to 21 d, and increased FI from 35 to 42 d and from 10 to 42 d. CMA also significantly increased the apparent retention of crude lipid, crude protein, ash and phosphorus. All three mycotoxin-adsorbent treatments significantly improved the L* values of breast and thigh muscle when compared with the mould-contaminated group. Supplementation with 0·1% CMA in the contaminated diet significantly decreased b* value and improved tenderness in thigh muscle. 0·05% EGM significantly decreased b* value of thigh muscle compared to mould-contaminated group. 4. The results indicated that mycotoxins in contaminated feed retard growth, nutrient retention and meat quality, whereas the addition of 0·05% EGM, 0·2% HSCAS or 0·1% CMA prevents the adverse effects of mycotoxins to varying extents, with 0·1% CMA being the most effective adsorbent treatment.

  5. Inhibition of ochratoxigenic moulds by Debaryomyces hansenii strains for biopreservation of dry-cured meat products.

    Science.gov (United States)

    Andrade, Maria J; Thorsen, Line; Rodríguez, Alicia; Córdoba, Juan J; Jespersen, Lene

    2014-01-17

    The ability of the osmotolerant yeast Debaryomyces hansenii to inhibit Penicillium nordicum, the most common ochratoxigenic mould encountered in dry-cured meat products, was evaluated. The antagonistic effect of ten D. hansenii strains isolated from dry-cured ham was screened in vitro using malt extract media and meat extract peptone media with the water activity (a(w)) adjusted to 0.97 and 0.90. A significant inhibition of the two tested P. nordicum strains by D. hansenii cells and cell-free supernatants was observed. At 0.97 a(w), increasing D. hansenii inoculum concentrations significantly improved the inhibition of mould growth on solid medium, whereas at 0.90 a(w) this was not always the case. As observed by bright field microscopy, most D. hansenii strains were able to delay P. nordicum spore germination when co-cultured in malt extract broth. D. hansenii FHSCC 253H showed the highest overall in vitro inhibition of ochratoxigenic mould growth, and was therefore chosen for co-cultivation assays in dry-cured ham slices incubated at 0.94 and 0.84 a(w) simulating ham ripening. Regardless of the experimental conditions tested, lower levels of the inoculated P. nordicum strain were detected in co-cultivation batches compared with batches without D. hansenii. The highest level of mould growth inhibition was observed in batches at 0.94 a(w). Ochratoxin A (OTA) production in ham samples was detected by HPLC-MS. Co-culturing of P. nordicum with D. hansenii FHSCC 253H resulted in lower OTA levels compared with control samples without D. hansenii. The decrease of the mycotoxin presence due to D. hansenii FHSCC 253H was more efficient at 0.94 a(w) (OTA was below the detection limit). In conclusion, D. hansenii is potentially suitable as a biopreservative agent for preventing ochratoxigenic mould growth and OTA accumulation in dry-cured meat products. The inoculation of D. hansenii should be made at the beginning of processing (at the end of post salting) when the a(w) of

  6. Effect of moulding sand on statistically controlled hybrid rapid casting solution for zinc alloys

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Rupinder [Guru Nanak Dev Engineering College, Ludhiana (India)

    2010-08-15

    The purpose of the present investigations is to study the effect of moulding sand on decreasing shell wall thickness of mould cavities for economical and statistically controlled hybrid rapid casting solutions (combination of three dimensional printing and conventional sand casting) for zinc alloys. Starting from the identification of component/ benchmark, technological prototypes were produced at different shell wall thicknesses supported by three different types of sands (namely: dry, green and molasses). Prototypes prepared by the proposed process are for assembly check purpose and not for functional validation of the parts. The study suggested that a shell wall with a less than recommended thickness (12mm) is more suitable for dimensional accuracy. The best dimensional accuracy was obtained at 3mm shell wall thickness with green sand. The process was found to be under statistical control

  7. Intra- and inter-individual variability of Aspergillus fumigatus reactive T-cell frequencies in healthy volunteers in dependency of mould exposure in residential and working environment.

    Science.gov (United States)

    Wurster, Sebastian; Weis, Philipp; Page, Lukas; Helm, Johanna; Lazariotou, Maria; Einsele, Hermann; Ullmann, Andrew J

    2017-10-01

    Invasive aspergillosis remains a deadly disease in immunocompromised patients, whereas the combination of an exaggerated immune response and continuous exposure lead to various hyperinflammatory diseases. This pilot study aimed to gain an overview of the intra- and inter-individual variability in Aspergillus fumigatus reactive T-helper cells in healthy adults and the correlation with environmental mould exposure. In this flow cytometric study, the frequencies of CD154 + A. fumigatus reactive T cells were evaluated in 70 healthy volunteers. All subjects completed a standardised questionnaire addressing their mould exposure. Subjects with intensive mould exposure in their professional or residential surrounding demonstrated considerably higher mean frequencies of A. fumigatus reactive T-helper and T-memory cells. Comparative evaluation of multiple measurements over time demonstrated relatively conserved reactive T-cell frequencies in the absence of major changes to the exposure profile, whereas those frequently exposed in professional environment or with changes to their risk score demonstrated a marked dependency of antigen reactive T-cell frequencies on recent mould exposure. This pilot study was the first to provide data on the intra-individual variability in A. fumigatus reactive T-cell frequencies and its linkage to mould encounter. Fungus reactive T cells are to be considered a valued tool for the assessment of environmental mould exposure. © 2017 Blackwell Verlag GmbH.

  8. Constructing an Efficient Self-Tuning Aircraft Engine Model for Control and Health Management Applications

    Science.gov (United States)

    Armstrong, Jeffrey B.; Simon, Donald L.

    2012-01-01

    Self-tuning aircraft engine models can be applied for control and health management applications. The self-tuning feature of these models minimizes the mismatch between any given engine and the underlying engineering model describing an engine family. This paper provides details of the construction of a self-tuning engine model centered on a piecewise linear Kalman filter design. Starting from a nonlinear transient aerothermal model, a piecewise linear representation is first extracted. The linearization procedure creates a database of trim vectors and state-space matrices that are subsequently scheduled for interpolation based on engine operating point. A series of steady-state Kalman gains can next be constructed from a reduced-order form of the piecewise linear model. Reduction of the piecewise linear model to an observable dimension with respect to available sensed engine measurements can be achieved using either a subset or an optimal linear combination of "health" parameters, which describe engine performance. The resulting piecewise linear Kalman filter is then implemented for faster-than-real-time processing of sensed engine measurements, generating outputs appropriate for trending engine performance, estimating both measured and unmeasured parameters for control purposes, and performing on-board gas-path fault diagnostics. Computational efficiency is achieved by designing multidimensional interpolation algorithms that exploit the shared scheduling of multiple trim vectors and system matrices. An example application illustrates the accuracy of a self-tuning piecewise linear Kalman filter model when applied to a nonlinear turbofan engine simulation. Additional discussions focus on the issue of transient response accuracy and the advantages of a piecewise linear Kalman filter in the context of validation and verification. The techniques described provide a framework for constructing efficient self-tuning aircraft engine models from complex nonlinear

  9. A Market Equilibrium Supply Chain Model for Supporting Self-Manufacturing or Outsourcing Decisions in Prefabricated Construction

    OpenAIRE

    Yanhu Han; Miroslaw J. Skibniewski; Lufan Wang

    2017-01-01

    Prefabricated construction is a sustainable alternative to traditional on-site construction methods. However, many challenges still exist in the prefabricated construction process. For example, self-manufacturing or outsourcing decisions are vital to the industrial structure and organization of the prefabricated construction industry, and the company’s production and operation decision-making. This paper considers a prefabricated construction supply chain, which is composed of one upstream co...

  10. The Optimisation of Processing Condition for Injected Mould Polypropylene-Nanoclay-Gigantochloa Scortechinii based on Melt Flow Index

    Science.gov (United States)

    Othman, M. H.; Rosli, M. S.; Hasan, S.; Amin, A. M.; Hashim, M. Y.; Marwah, O. M. F.; Amin, S. Y. M.

    2018-03-01

    The fundamental knowledge of flow behaviour is essential in producing various plastic parts injection moulding process. Moreover, the adaptation of advanced polymer-nanocomposites such as polypropylene-nanoclay with natural fibres, for instance Gigantochloa Scortechinii may boost up the mechanical properties of the parts. Therefore, this project was proposed with the objective to optimise the processing condition of injected mould polypropylene-nanoclay-Gigantochloa Scortechini fibres based on the flow behaviour, which was melt flow index. At first, Gigantochloa Scortechinii fibres have to be preheated at temperature 120°C and then mixed with polypropylene, maleic anhydride modified polypropylene oligomers (PPgMA) and nanoclay by using Brabender Plastograph machine. Next, forms of pellets were produced from the samples by using Granulator machine for use in the injection moulding process. The design of experiments that was used in the injection moulding process was Taguchi Method Orthogonal Array -L934. Melt Flow Index (MF) was selected as the response. Based on the results, the value of MFI increased when the fiber content increase from 0% to 3%, which was 17.78 g/10min to 22.07 g/10min and decreased from 3% to 6%, which was 22.07 g/10min to 20.05 g/10min and 3%, which gives the highest value of MFI. Based on the signal to ratio analysis, the most influential parameter that affects the value of MFI was the melt temperature. The optimum parameter for 3% were 170°C melt temperature, 35% packing pressure, 30% screw speed and 3 second filling time.

  11. CaSO4: Dy + Teflon dosimetric pellets for X, beta and gamma radiation detection

    International Nuclear Information System (INIS)

    Campos, L.L.; Lima, M.F.

    1987-08-01

    CaSO 4 : Dy + TEFLON dosimetric pellets with high sensitivity and low cost for X, beta and gamma radiation monitoring were studied and developed by the Dosimetric Material Production Laboratory of the Radiological Protection Departament and are disposable for sale. The thickness of the pellets are suitable for X, beta and gamma radiation measurements. The dosimetric properties of these pellets were determined and presented in this work. The results show the usefulness of 0,20mm thick pellets for beta radiation monitoring and 0,80mm thick pellets for x and gamma radiation detection. (Author) [pt

  12. Inhibitory activity of Indian spice plant Cinnamomum zeylanicum extracts against Alternaria solani and Curvularia lunata, the pathogenic dematiaceous moulds

    Directory of Open Access Journals (Sweden)

    Sharma Bechan

    2009-03-01

    Full Text Available Abstract Background Dematiaceous moulds are pathogenic microorganisms and act as etiological agents of mycoses with different degrees of severity in humans and animals. These moulds also cause loss of food crops and storage food products. The information regarding antimicrobial efficacy of the plant preparations on these moulds is scanty. The present study reveals phytochemical characterization and the effect of bark and leaf extracts of Indian spice plant, Cinnamomum zeylanicum (Cz, against the growth of two species of dematiaceous moulds, Alternaria solani and Curvularia lunata. Methods Cz bark and leaf samples were sequentially extracted in different solvents using Soxhlet apparatus. Phytochemical analyses of extracts were done as per standard protocols. The antifungal bioassay of extracts was done by hanging drop technique. The inhibition of fungal spore germination was monitored under influence of three different concentrations of extracts. Results The lowest test concentration (50 μg/ml of extracts of Cz bark prepared into acetone and that of Cz leaf into petroleum ether and ethanol exhibited complete inhibition (100% of spore germination in both the moulds. At 100 μg/ml concentration all the extracts showed about 50 to 100% inhibition. However, the treatment of the spores of the two fungal species with highest concentration (500 μg/ml of bark and leaf extracts in all the solvents showed 100% fungicidal activity as it completely arrested the germination of spores. Relatively lower activity of aqueous extracts at 50 and 100 μg/ml concentrations suggests that the antifungal ingredients present in Cz bark and leaf are more soluble in organic solvents than water. Conclusion The results demonstrated that the Cz bark and leaves contain certain fungicidal constituents exhibiting potential antimould activity against A. solani and C. lunata.

  13. Influence of Storage of Wet Arabica Parchment Prior to Wet Hulling on Moulds Development, OchratoxinA Contamination, and Cup Quality of Mandheling Coffee

    Directory of Open Access Journals (Sweden)

    Cahya Ismayadi

    2005-08-01

    Full Text Available Mandheling coffee has been a well known specialty coffees for decades and the demand for this coffee is currently increasing. This coffee is characterised by low acidity, heavy-complex body, spicy-little earthy and fruity flavor. Mandheling coffee is produced by smallholder farmers in the highland surrounding Lake TobaNorth Sumatra in an unique way i.e. following de-pulping and 1–2 days sundrying, wet parchment is stored for varying periods up to a few weeks, the parchments are then de-hulled when still wet (40–45% moisture content then the beans sundried. The handling procedure presumably contributes to the unique cup character of Mandheling coffee. On the other hand the storage of wet pachments may cause mould growth and mycotoxin contamination. This trial was designed to study the influence of storage of wet parchments prior to wet hulling on mould development, OTA contamination and cup Mandheling characteristic of the coffee product. The normal wet process, drying of parchment thoroughly to 12% moisture content was used as the control. Parchment coffees (6 lots used for this trial were drawn from farmers and collectors in the region. The wet parchments (41.74–53.96% moisture content were stored for 1 (D1, 7 (D7 and 14 (D14 days in PE sacks in a warehouse in the region. During the storage period, when there was visible mould growth, the parchments were spread on a plastic sheet inside the warehouse, as per common practice to suppress the mould growth. Following storage, the wet parchment was de-hulled and then sun-dried to a moisture content of 12% (MC12% or dried to a moisture content of 17%, and held in storage for 3 weeks prior to final drying to 12% mc. The ‘normal wet process’ i.e. fresh-non stored parchments dried thoroughly to 12%, were used as the control. Parameters measured were visual evaluation, mould infestation, a w, moisture content (MC on the stored parchment; while for dried beans mould infestation, OTA content and

  14. Studies on the Gases Emission under High Temperature Condition from Moulding Sands Bonded by Modified Starch CMS-Na

    Directory of Open Access Journals (Sweden)

    Kaczmarska K.

    2017-03-01

    Full Text Available Emission of gases under high temperature after pouring molten metal into moulds, which contain the organic binder or other additives (solvents or curing agent, may be an important factor influencing both on the quality of the produced castings, and on the state of environment. Therefore, a comprehensive study of the emitted gases would allow to determine restrictions on the use of the moulding sands in foundry technologies, eg. the probability of occurrence of casting defects, and identify the gaseous pollutants emitted to the environment. The aim of the research presented in this paper was to determine the amount of gases that are released at high temperatures from moulding sands bonded by biopolymer binder and the quantitative assessment of the emitted pollutants with particular emphasis on chemical compounds: benzene, toluene, ethylbenzene and xylenes (BTEX. The water-soluble modified potato starch as a sodium carboxymethyl starch with low (CMS-NaL or high (CMS-NaH degree of substitution was a binder in the tested moulding sands. A tests of gases emission level were conducted per the procedure developed at the Faculty of Foundry Engineering (AGH University of Science and Technology involving gas chromatography method (GC. The obtained results of the determination of amount of BTEX compounds generated during the decomposition process of starch binders showed lower emission of aromatic hydrocarbons in comparison with binder based on resin Kaltharz U404 with the acidic curing agent commonly used in the foundries.

  15. 25 CFR 900.131 - What role does the Secretary play during the performance of a self-determination construction...

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false What role does the Secretary play during the performance... CONTRACTS UNDER THE INDIAN SELF-DETERMINATION AND EDUCATION ASSISTANCE ACT Construction § 900.131 What role does the Secretary play during the performance of a self-determination construction contract? (a) If...

  16. Selection of halophilic bacteria for biological control of tomato gray mould caused by Botrytis cinerea

    Directory of Open Access Journals (Sweden)

    Imane BERRADA

    2013-01-01

    Full Text Available In Morocco, tomato gray mould caused by Botrytis cinerea Pers: Fr. is a serious threat for postharvest storage of tomatoes. Fifteen halophilic bacteria were evaluated for their antagonistic activity against B. cinerea: 11 Gram positive strains assigned to the genera Bacillus (9, Jeotgalibacillus (1 and Planococcus (1 and four Gram negative strains assigned to the genera Salinivibrio (1, Vibrio (2 and Photobacterium (1. In in vitro screening, 12 antifungal isolates secreted diffusible compounds, hydrolytic enzymes or volatile compounds. In vivo screening of the isolates, Bacillus safensis CCMM B582 and Bacillus oceanisediminis CCMM B584 showed permanent antagonistic activity on tomato fruits, with 100% inhibition of B. cinerea after 7 days. These two strains may offer potential for biological control of tomato gray mould.

  17. Micro injection moulding process validation for high precision manufacture of thermoplastic elastomer micro suspension rings

    DEFF Research Database (Denmark)

    Calaon, M.; Tosello, G.; Elsborg Hansen, R.

    Micro injection moulding (μIM) is one of the most suitable micro manufacturing processes for flexible mass-production of multi-material functional micro components. The technology was employed in this research used to produce thermoplastic elastomer (TPE) micro suspension rings identified...... main μIM process parameters (melt temperature, injection speed, packing pressure) using the Design of Experiment statistical technique. Measurements results demonstrated the importance of calibrating mould´s master geometries to ensure correct part production and effective quality conformance...... on the frequency in order to improve the signal quality and assure acoustic reproduction fidelity. Production quality of the TPE rings drastically influence the product functionality. In the present study, a procedure for μIM TPE micro rings production optimization has been established. The procedure entail using...

  18. Specific character of sustainable innovative development of transport construction in self-regulation conditions

    Science.gov (United States)

    Gumba, Khuta; Belyaeva, Svetlana

    2017-10-01

    The providing of sustainable development is impossible without activating the innovative activity of backbone economical sectors, in particular of transport construction. The system of self-regulation of activities is a specific feature of the transport industry development. The authors carried out the correlation analysis of innovative activity of construction enterprises, which proved the necessity of improving the normative and technical documents. The authors proposed and calculated the index of the legislation stability in the industry. The article suggests recommendations on the activation of innovative development in construction industry basing on the results of the modeling.

  19. Melt state behaviour of PEEK and processing window interpretation for fast compression moulding process

    International Nuclear Information System (INIS)

    Bessard, Emeline; De Almeida, Olivier; Bernhart, Gerard

    2011-01-01

    Fast mould heating is nowadays possible by using induction technology for example with the Cage System registered developed by RocTool. It allows heating and cooling kinetics of about 100 deg. C per minute and new perspectives are thus possible to optimize the compression moulding process of long fibre reinforced thermoplastic composites. Indeed, a high forming temperature may favour polymer creep and so on composite consolidation. Nevertheless, the processing time of PEEK composite above melt temperature must be reduced to a few minutes due to the fast thermal degradation of the matrix. On the other hand, high cooling rates may have negative effect on matrix crystallinity. The proposed procedure consist in performing a few minutes isotherm around 300 deg. C during the fast cooling. It would favour a high degree of crystallinity of PEEK without extending the cycle time.

  20. Investigation of Plasma Treatment on Micro-Injection Moulded Microneedle for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Karthik Nair

    2015-10-01

    Full Text Available Plasma technology has been widely used to increase the surface energy of the polymer surfaces for many industrial applications; in particular to increase in wettability. The present work was carried out to investigate how surface modification using plasma treatment modifies the surface energy of micro-injection moulded microneedles and its influence on drug delivery. Microneedles of polyether ether ketone and polycarbonate and have been manufactured using micro-injection moulding and samples from each production batch have been subsequently subjected to a range of plasma treatment. These samples were coated with bovine serum albumin to study the protein adsorption on these treated polymer surfaces. Sample surfaces structures, before and after treatment, were studied using atomic force microscope and surface energies have been obtained using contact angle measurement and calculated using the Owens-Wendt theory. Adsorption performance of bovine serum albumin and release kinetics for each sample set was assessed using a Franz diffusion cell. Results indicate that plasma treatment significantly increases the surface energy and roughness of the microneedles resulting in better adsorption and release of BSA.

  1. Mould deterioration of agricultural commodities during transit: problems faced by developing countries.

    Science.gov (United States)

    Bhat, R V

    1988-12-01

    Huge quantities of agricultural commodities are being either imported or exported by the developing countries. The commodities have to be transported from the fields of cultivation to the centres of consumption, considerable time being taken for the movement not only because of long distances but also because of various socio-economic, environmental and biological reasons. These commodities are likely to be damaged by mould growth and subsequent aflatoxin accumulation. If the contamination occurs during transit, often no insurance cover for the risk is available. Because of different methods of sampling followed in the exporting and importing countries it is often difficult to define the exact responsibility of the development of aflatoxin as having taken place during transit. The statistics of the export of aflatoxin high-risk commodities like red pepper (chillies), cotton seed and groundnut extractions clearly, for the last decade, demonstrate the extent of loss suffered by the exporting countries because of aflatoxins. The problem of mould damage and mycotoxin contamination can be minimised by improving facilities for storage at ports and transit points as well as on ships.

  2. Covalent immobilisation of antibodies in Teflon-FEP microfluidic devices for the sensitive quantification of clinically relevant protein biomarkers.

    Science.gov (United States)

    Pivetal, Jeremy; Pereira, Filipa M; Barbosa, Ana I; Castanheira, Ana P; Reis, Nuno M; Edwards, Alexander D

    2017-03-13

    This study reports for the first time the sensitive colorimetric and fluorescence detection of clinically relevant protein biomarkers by sandwich immunoassays using the covalent immobilisation of antibodies onto the fluoropolymer surface inside Teflon®-FEP microfluidic devices. Teflon®-FEP has outstanding optical transparency ideal for high-sensitivity colorimetric and fluorescence bioassays, however this thermoplastic is regarded as chemically inert and very hydrophobic. Covalent immobilisation can offer benefits over passive adsorption to plastic surfaces by allowing better control over antibody density, orientation and analyte binding capacity, and so we tested a range of different and novel covalent immobilisation strategies. We first functionalised the inner surface of a 10-bore, 200 μm internal diameter FEP microcapillary film with high-molecular weight polyvinyl alcohol (PVOH) without changing the outstanding optical transparency of the device delivered by the matched refractive index of FEP and water. Glutaraldehyde immobilisation was compared with the use of photoactivated linkers and NHS-ester crosslinkers for covalently immobilising capture antibodies onto PVOH. Three clinically relevant sandwich ELISAs were tested against the cytokine IL-1β, the myocardial infarct marker cardiac troponin I (cTnI), and the chronic heart failure marker brain natriuretic peptide (BNP). Overall, glutaraldehyde immobilisation was effective for BNP assays, but yielded unacceptable background for IL-1β and cTnI assays caused by direct binding of the biotinylated detection antibody to the modified PVOH surface. We found NHS-ester groups reacted with APTES-treated PVOH coated fluoropolymers. This facilitated a novel method for capture antibody immobilisation onto fluoropolymer devices using a bifunctional NHS-maleimide crosslinker. The density of covalently immobilised capture antibodies achieved using PVOH/APTES/NHS/maleimide approached levels seen with passive adsorption

  3. Numerical modelling of heat transfer in a cavity due to liquid jet impingement for liquid supported stretch blow moulding

    Science.gov (United States)

    Smyth, Trevor; Menary, Gary; Geron, Marco

    2018-05-01

    Impingement of a liquid jet in a polymer cavity has been modelled numerically in this study. Liquid supported stretch blow moulding is a nascent polymer forming process using liquid as the forming medium to produce plastic bottles. The process derives from the conventional stretch blow moulding process which uses compressed air to deform the preform. Heat transfer away from the preform greatly increases when a liquid instead of a gas is flowing over a solid; in the blow moulding process the temperature of the preform is tightly controlled to achieve optimum forming conditions. A model was developed with Computational Fluid Dynamics code ANSYS Fluent which allows the extent of heat transfer between the incoming liquid and the solid preform to be determined in the initial transient stage, where a liquid jet enters an air filled preform. With this data, an approximation of the extent of cooling through the preform wall can be determined.

  4. FAILURE MODE EFFECTS AND CRITICALITY ANALYSIS (FMECA AS A QUALITY TOOL TO PLAN IMPROVEMENTS IN ULTRASONIC MOULD CLEANING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Cristiano Fragassa

    2016-12-01

    Full Text Available Inside the complex process used for tire production, ultrasonic cleaning treatment probably represents the best solution to preserve the functionality of tire moulds, by removing residuals from moulds and keeping an unaltered quality for their surfaces. Ultrasonic Mould Cleaning Systems (UMCS is, however, a complicated technology that combines ultrasonic waves, high temperature and a succession of acid and basic attacks. At the same time, an UMCS plant, as part of a long productive chain, has to guarantee the highest productivity reducing failures and maintenances. This article describes the use of Failure Mode Effects and Criticality Analysis (FMECA as a methodology for improving quality in cleaning process. In particular, FMECA was utilized to identify potential defects in the original plant design, to recognize the inner causes of some failures actually occurred during operations and, finally, to suggest definitive re-design actions. Changes were implemented and the new UMCS offers a better quality in term of higher availability and productivity.

  5. PROTVINO: Mass-production of scintillator tiles by injection moulding

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The technique of the segmented sandwich-calorimeters with wavelength-shifting readout, especially its large-scale application in big detectors, requires enormous quantities of a cheap scintillator tiles of moderate dimensions (20 x 20 cm 2 ). Initial trials carried out in the Institute for High Energy Physics (IHEP), Protvino, Russia almost ten years ago showed that manufacturing such scintillator tiles was possible using an ordinary commercially-available granulated optical polystyrene, an existing technology of plastic dyeing, and a well-known process of the injection moulding, used to produce plastic goods (like buttons!)

  6. Application of Microwaves for Binder Content Assessment in Moulding Sands

    Directory of Open Access Journals (Sweden)

    Nowak D.

    2012-09-01

    Full Text Available The paper presents results of preliminary examinations on possibility of determining binder content in traditional moulding sands with the microwave method. The presented measurements were carried-out using a special stand, the so-called slot line. Binder content in the sandmix was determined by measurements of absorption damping Ad and insertion losses IL of electromagnetic wave. One of main advantages of the suggested new method of binder content measurement is short measuring time.

  7. Moulded Pulp Manufacturing: Overview and Prospects for the Process Technology

    DEFF Research Database (Denmark)

    Didone, Mattia; Saxena, Prateek; Meijer, Ellen Brilhuis

    2017-01-01

    Eco-friendly packaging such as moulded pulp products have gained commercial importance in the recent years. However, it remains a greatly under-researched area, and there is an arising need to consolidate the best practices from research and industry in order to increase its implementation....... Moreover, based on the latest research in the field, an innovative drying technique that utilizes concepts derived from impulse drying is presented, and the implementation of this process technology is discussed....

  8. Assessment of concrete characteristics during the deliberate deformation of a flexible mould after casting

    NARCIS (Netherlands)

    Schipper, H.R.; Grunewald, S.; Troian, S.; Raghunath, P.; Schlangen, H.E.J.G.; Copuroglu, O.; Pecur, I.B.; Baricevic, A.; Stirmer, N; Bjegovic, D.

    2017-01-01

    Expensive CNC (computer numerical controlled)-milled formwork is required for the production of double-curved precast concrete elements for cladding or shell structures. The innovative flexible mould method for economically efficient and sustainable production of such elements, developed at Delft

  9. Evaluation of optical functional surfaces on the injection moulding insert by micro milling process

    DEFF Research Database (Denmark)

    Li, Dongya; Davoudinejad, Ali; Zhang, Yang

    2017-01-01

    This study presents the optimization of micro milling process for manufacturing injection moulding inserts with an optical functionalsurface. The objective is the optimal surface functionality. Micro ridges were used as the microstructures to realize the function to generate contrast between...

  10. Rapid preparation of ceramic moulds for medium-sized superalloy castings with magnesia-phosphate-bonded bauxite-mullite investments

    Directory of Open Access Journals (Sweden)

    Li Tingzhong

    2010-11-01

    Full Text Available Phosphate-bonded investments have already been widely utilized in dental restoration and micro-casting of artistic products for its outstanding rapid setting and high strength. However, the rapid setting rate of investment slurry has up to now been a barrier to extend the use of such slurry in preparation of medium-sized ceramic moulds. This paper proposes a new process of rapid fabrication of magnesia-phosphate-bonded investment ceramic moulds for medium-sized superalloy castings utilizing bauxite and mullite as refractory aggregates. In order to determine the properties of magnesia-phosphate-bonded bauxite-mullite investments (MPBBMI, a series of experiments were conducted, including modification of the workable time of slurry by liquid(mL/powder(g(L/P ratio and addition of boric acid as retard agent and sodium tri-polyphosphate (STP as strengthening agent, and adjustment of bauxite (g/mullite(g(B/M ratio for mechanical strength. Mechanical vibration was applied to improve initial setting time and fluidity when pouring investment slurry; then an intermediate size ceramic mould for superalloy castings was manufactured by means of this rapid preparing process with MPBBMI material. The results showed that the MPBBMI slurry exhibits proper initial setting time and excellent fluidity when the L/P ratio is 0.64 and the boric acid content is 0.88wt.%. The fired specimens made from the MPBBMI material demonstrated adequate compression strength to withstand impact force of molten metal when the B/M ratio is 0.89 and the STP content is 0.92wt.%. The experimental results confirmed the feasibility of the proposed rapid fabricating process for medium-sized ceramic moulds with MPBBMI material by appropriate measures.

  11. The Use of Particulate Injection Moulding for Fabrication of Sports and Leisure Equipment from Titanium Metals

    Directory of Open Access Journals (Sweden)

    Paul D. Ewart

    2018-02-01

    Full Text Available Advanced materials such as metal alloys, carbon fibre composites and engineered polymers have improved athlete performances in all sporting applications. Advances in manufacturing has enabled increases in design complexity and the ability to rapidly prototype bespoke products using additive manufacturing also known as 3D printing. Another recent fabrication method widely used by medical, electronics and armaments manufacturers is particulate injection moulding. This process uses exact quantities of the required material, in powder form, minimising resource and energy requirements in comparison to conventional manufacturing techniques. The process utilises injection moulding techniques and tooling methods developed and used in the plastics industry. It can produce highly complex component geometries with excellent repeatability and reduced cost where volume manufacturing is required. This is especially important when considering materials such as titanium that are not only expensive in comparison to other metals but are difficult to process by regular machining and fabrication methods. This work presents a review of titanium use in the sporting sector with a focus on sporting devices and equipment. It also proposes that the sports engineering sector could increase performance and enable improvements in safety by switching to design methods appropriate to processing via the particulate injection moulding route.

  12. Cycle time improvement for plastic injection moulding process by sub groove modification in conformal cooling channel

    Science.gov (United States)

    Kamarudin, K.; Wahab, M. S.; Batcha, M. F. M.; Shayfull, Z.; Raus, A. A.; Ahmed, Aqeel

    2017-09-01

    Mould designers have been struggling for the improvement of the cooling system performance, despite the fact that the cooling system complexity is physically limited by the fabrication capability of the conventional tooling methods. However, the growth of Solid Free Form Technology (SFF) allow the mould designer to develop more than just a regular conformal cooling channel. Numerous researchers demonstrate that conformal cooling channel was tremendously given significant result in the improvement of productivity and quality in the plastic injection moulding process. This paper presents the research work that applies the passive enhancement method in square shape cooling channel to enhance the efficiency of cooling performance by adding the sub groove to the cooling channel itself. Previous design that uses square shape cooling channel was improved by adding various numbers of sub groove to meet the best sub groove design that able reduced the cooling time. The effect of sub groove design on cooling time was investigated by Autodesk Modlflow Insight software. The simulation results showed that the various sub groove designs give different values to ejection time. The Design 7 showed the lowest value of ejection time with 24.3% increment. The addition of sub groove significantly increased a coolant velocity and a rate of heat transfer from molten plastic to coolant.

  13. OECD's Brief Self-Report Measure of Educational Psychology's Most Useful Affective Constructs: Cross-Cultural, Psychometric Comparisons across 25 Countries

    Science.gov (United States)

    Marsh, Herbert W.; Hau, Kit-Tai; Artelt, Cordula; Baumert, Jurgen; Peschar, Jules L.

    2006-01-01

    Through a rigorous process of selecting educational psychology's most useful affective constructs, the Organisation for Economic Co-operation and Development (OECD) constructed the Students' Approaches to Learning (SAL) instrument, which requires only 10 min to measure 14 factors that assess self-regulated learning strategies, self-beliefs,…

  14. THE CONSTRUCTION OF A QUESTIONNAIRE TO MEASURE SELF-INDUCED CONCATENATED DEMOTIVATION

    Directory of Open Access Journals (Sweden)

    Josko Sindik

    2013-12-01

    Full Text Available The concept of self-induced concatenated demotivation describes the “chain“ of demotivational processes and interactions of employees, in the contexts of postsocialism, job characteristics, dominant forms of motivation and group cohesion in work organizations. The aim of the preliminary research was to construct a questionnaire to measure the concept of self-induced concatenated demotivation and the relations between its latent dimensions. The study included a “snowball“ sample of 196 participants aged 20 to 65, of both genders, with heterogeneous professions and degrees in education. Based on the results of factor analysis three latent dimensions have been obtained, that account for only 36% of the total variance of the manifest area of self-induced concatenated demotivation, which we have named: pessimism/rationalization, social orientation, the ability to evaluate other people. The questionnaire to measure self-induced concatenated demotivation of employees has proved to be a low but satisfactory reliable measuring instrument for all three dimensions of the concept.

  15. Uptake of caesium-137 from peat and compost mould by vegetables in a greenhouse experiment

    International Nuclear Information System (INIS)

    Malm, J.; Uusi-Rauva, A.; Paakkola, O.

    1991-01-01

    A pot experiment was conducted to study the root uptake of 137 Cs by vegetables grown in peat and composite mould in a greenhouse. The 137 Cs in the growing media originated from Chernobyl fallout. The vegetables were cucumber (Cucumis sativus L. var. Farbio VDP SF 76), tomato (Lycopersicon esculentum L. Var. Virosa), parsley (Petroselinum crispum A.W. Hill var. Non plus ultra), radish (Raphanus Sativus L. var. Nondan) and lettuce (Lactuca sativa L. var Atraktion). The effect of adding potassium to the peat was also studied. The transfer factors (activity in plant dry weight/activity in soil dry weight) varied from 0.66 to 1.8 for peat and from 0.060 to 0.19 for compost mould. Addition of potassium did not have any clear effect on the transfer factors. (Author)

  16. Uptake of caesium-137 from peat and compost mould by vegetables in a greenhouse experiment

    Energy Technology Data Exchange (ETDEWEB)

    Malm, J.; Uusi-Rauva, A.; Paakkola, O. (Helsinki Univ. (Finland). Faculty of Agriculture and Forestry); Rantavaara, A. (Finnish Centre for Radiation and Nuclear Safety (STUK), Helsinki (Finland))

    1991-01-01

    A pot experiment was conducted to study the root uptake of {sup 137} Cs by vegetables grown in peat and composite mould in a greenhouse. The {sup 137}Cs in the growing media originated from Chernobyl fallout. The vegetables were cucumber (Cucumis sativus L. var. Farbio VDP SF 76), tomato (Lycopersicon esculentum L. Var. Virosa), parsley (Petroselinum crispum A.W. Hill var. Non plus ultra), radish (Raphanus Sativus L. var. Nondan) and lettuce (Lactuca sativa L. var Atraktion). The effect of adding potassium to the peat was also studied. The transfer factors (activity in plant dry weight/activity in soil dry weight) varied from 0.66 to 1.8 for peat and from 0.060 to 0.19 for compost mould. Addition of potassium did not have any clear effect on the transfer factors. (Author).

  17. Transport of organic solutes through amorphous teflon AF films.

    Science.gov (United States)

    Zhao, Hong; Zhang, Jie; Wu, Nianqiang; Zhang, Xu; Crowley, Katie; Weber, Stephen G

    2005-11-02

    Fluorous media have great potential for selective extraction (e.g., as applied to organic synthesis). Fluorous polymer films would have significant advantages in fluorous separations. Stable films of Teflon AF 2400 were cast from solution. Films appear defect-free (SEM; AFM). Rigid aromatic solutes are transported (from chloroform solution to chloroform receiving phase) in a size-dependent manner (log permeability is proportional to -0.0067 times critical volume). Benzene's permeability is about 2 orders of magnitude higher than in comparable gas-phase experiments. The films show selectivity for fluorinated solutes in comparison to the hydrogen-containing control. Transport rates are dependent on the solvent making up the source and receiving phases. The effect of solvent is, interestingly, not due to changes in partition ratio, but rather it is due to changes in the solute diffusion coefficient in the film. Solvents plasticize the films. A less volatile compound, -COOH-terminated poly(hexafluoropropylene oxide) (4), plasticizes the films (T(g) = -40 degrees C). Permeabilities are decreased in comparison to 4-free films apparently because of decreased diffusivity of solutes. The slope of dependence of log permeability on critical volume is not changed, however.

  18. Effects of Gas-Wall Partitioning in Teflon Tubing, Instrumentation and Other Materials on Time-Resolved Measurements of Gas-Phase Organic Compounds

    Science.gov (United States)

    Pagonis, D.; Deming, B.; Krechmer, J. E.; De Gouw, J. A.; Jimenez, J. L.; Ziemann, P. J.

    2017-12-01

    Recently it has been shown that gas-phase organic compounds partition to and from the walls of Teflon environmental chambers. This process is fast, reversible, and can be modeled as absorptive partitioning. Here these studies were extended to investigate gas-wall partitioning inside Teflon tubing by introducing step function changes in the concentration of compounds being sampled and measuring the delay in the response of a proton transfer reaction-mass spectrometer (PTR-MS). We find that these delays are significant for compounds with a saturation vapor concentration (c*) below 106 μg m-3, and that the Teflon tubing and the PTR-MS both contribute to the delays. Tubing delays range from minutes to hours under common sampling conditions and can be accurately predicted by a simple chromatography model across a range of tubing lengths and diameters, flow rates, compound functional groups, and c*. This method also allows one to determine the volatility-dependent response function of an instrument, which can be convolved with the output of the tubing model to correct for delays in instrument response time for these "sticky" compounds. This correction is expected to be of particular interest to researchers utilizing and developing chemical ionization mass spectrometry (CIMS) techniques, since many of the multifunctional organic compounds detected by CIMS show significant tubing and instrument delays. These results also enable better design of sampling systems, in particular when fast instrument response is needed, such as for rapid transients, aircraft, or eddy covariance measurements. Additional results presented here extend this method to quantify the relative sorptive capacities for other commonly used tubing materials, including PFA, FEP, PTFE, PEEK, glass, copper, stainless steel, and passivated steel.

  19. Metal filters for the compensation of photon energy dependence of the response of CaSO4: Dy - Teflon TLD Discs

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Bhatt, R.C.

    1979-01-01

    Metal filters of aluminium, stainless steel, copper, cadmium, tin and lead were studied for compensation of the photon energy dependence of the response of CaSO 4 : Dy Teflon TLD Discs. It was found that metals such as cadmium and tin (which are normally used for this purpose) with their K absorption edges around 30 keV, are poor compensators of photon energy dependence. However, if either cadmium or tin is used in combination with either copper or stainless steel (with the lower Z filter nearer to the TLD dosimeter disc) a better compensation of photon energy dependence is achieved. Consequently, for personnel monitoring of X and gamma radiations, a TLD badge with CaSO 4 : Dy Teflon TLD discs and two sets of combination filters has been recommended. In the range of 27 keV -1.25 MeV this badge offers a photon energy response which varies within +-15%. This is a considerable improvement on the corresponding limits of +-65% on using a single filter. (orig.)

  20. Semiconductor Sensors Application for Definition of Factor of Ozone Heterogeneous Destruction on Teflon Surface

    Directory of Open Access Journals (Sweden)

    Nataliya V. Finogenova

    2003-12-01

    Full Text Available In our paper we present the results of our research, which was carried out by means of semiconductor sensor techniques (SCS, which allowed evaluating heterogeneous death-rate of ozone (γ Teflon surface. When ozone concentration is near to Ambient Air Standard value, γ is assessed to be equal to 6,57*10-7. High technique response provide possibility to determine ozone contents in the air media and the percentage of ozone, decomposed on the communication surfaces and on the surfaces of installation in the low concentration range (1–100 ppb.

  1. Properties of compression moulded new fully biobased thermoset composites with aligned flax fibre textiles

    DEFF Research Database (Denmark)

    Pohl, Th.; Bierer, M.; Natter, E.

    2011-01-01

    into composites using an industrial scale compression moulding machine, and their material properties were analysed. The density was calculated by using a computed microtomography system, and tensile tests were carried out. Besides the mechanical properties, the burning and the moisture absorption behaviour have...

  2. Co-constructing Understanding of Self Access through Conversational Narrative

    Directory of Open Access Journals (Sweden)

    John Adamson

    2010-12-01

    Full Text Available This study has shown how stakeholders of a new Self Access Learning Center (SALC co-construct views about the center’s development though conversational narratives. Conversational narratives are a means in this study to provide important insights into SALC’s growth and also represent sites of valuable social practice to strengthen collegiality among its participants. This dialogic process illustrates a diversity of perspectives which have emerged over the first year in its growth, and which inform the center’s management on metaphors of self access, language policy, its integration with university curricula, and how it and its staff are positioned in the organization. As part of a larger ethnographic study into the center, these unscripted, free-form dialogues are valued because they mirror the flat hierarchical structure which the center aims to support in its community of practice to legitimize its participants’ voices.

  3. Purification in the interaction between yttria mould and Nb-silicide-based alloy during directional solidification: A novel effect of yttrium

    International Nuclear Information System (INIS)

    Ma, Limin; Tang, Xiaoxia; Wang, Bin; Jia, Lina; Yuan, Sainan; Zhang, Hu

    2012-01-01

    Nb-silicide-based alloys were directionally solidified in yttria moulds. As a result of thermal dissociation of yttria, the alloys were slightly contaminated with oxygen, which caused a competitive oxidation between yttrium and hafnium. The addition of 0.15 at.% yttrium reduced the oxygen increment by 42%, because the buoyant inclusions concentrated around the top surface. The yttrium addition caused a significant purification of the interaction between the yttria mould and the Nb-silicide-based alloys during the directional solidification.

  4. Effect of moulding on the changes in chemical composition of tabacco leaves

    OpenAIRE

    Krystyna Florczak

    2014-01-01

    The process of moulding caused by the fungi: Aspergillus repens (Cda.) De Bart, Aspergillus flavus Link, Aspergillus ochraceus Wilhelm, Penicillium expansum (Link) Thom, VPenicillium commune Thom and Penicillum spinulosum Tom influenced the decrease in soluble carbohydrate content with the simulataneous increase in the percentage of specific protein. It had an effect on the deterioration of technological and taste values of raw tabacco.

  5. Investigating of the Knocking Out Properties of Moulding Sands with New Inorganic Binders Used for Castings of Non-ferrous Metal Alloys in Comparison with the Previously Used

    Directory of Open Access Journals (Sweden)

    I. Izdebska-Szanda

    2012-12-01

    Full Text Available The article presents the results of investigations, which make a fragment of the broad-scale studies carried out as a part of the projectPOIG.01.01.02-00-015/09 “Advanced materials and technologies”.One of the objectives of the introduction of new inorganic binders is to provide a good knocking out properties of moulding sands, whilemaintaining an appropriate level of strength properties.Therefore, a logical continuation of the previous studies were carried out the tests knocking out properties of moulding sands with newinorganic binders, including making moulds, pouring them by the chosen of non-ferrous metal alloys, knoking-out, and determining theknocking out work.The results of the study were related to the research results obtained by applying the moulding sand performed by existing technology.

  6. Micro Engineering: Experiments conducted on the use of polymeric materials in micro injection moulding

    DEFF Research Database (Denmark)

    Griffiths, Christian; Tosello, Guido; Nestler, Joerg

    2008-01-01

    To advance micro injection moulding it is necessary to study systematically the factors affecting process and tooling reliability. This paper reviews the main findings of Cardiff Universities 4M and SEMOFS research in this field. In particular, the factors affecting the manufacturability of micro...

  7. A new approach for the validation of filling simulations in micro injection moulding

    DEFF Research Database (Denmark)

    Gava, Alberto; Tosello, Guido; Lucchetta, Giovanni

    2007-01-01

    to be improved. The main objective of this work is to evaluate whether the present numerical codes are suitable to characterize melt flow patterns in a micro cavity. In order to test the accuracy of the software, real and simulated experiments were performed and used to investigate the filling of a micro moulded...

  8. Occurrence of potentially toxigenic mould species in fresh salads of different kinds of ready-for-use vegetables

    Directory of Open Access Journals (Sweden)

    Kocić-Tanackov Sunčica D.

    2010-01-01

    Full Text Available In the mycological survey of fresh salads of different vegetables, the collected samples were tested for total counts of moulds with special attention paid to the presence of potentially toxigenic species. The survey also included the isolation and the identification of species, as well as the evaluation of mycotoxin biosynthesis ability of potential producers of ochratoxin A (OA and sterigmatocystin (STC. Mould counts ranged from 10.0 to 4.7x102 cfu g-1. The most common moulds found in fresh salads were Cladosporium (42.89%, Penicillium (25.78%, Aspergillus (14.67% and Alternaria (6.89%. C. cladosporioides (40.44%, followed by A. niger (10.22%, P. aurantiogriseum (7.55%, A. alternata (6.89% and Fusarium spp. (3.11% were the most dominating species. Other species were represented with 2.22% (Eurotium spp., 1.56% (Botrytis spp., 0.67% (Phoma spp., 0.44% (Geotrichum spp., Mucor spp., Phialophora spp. and 0.22% (Emericella spp., Paecilomyces spp., Trichoderma spp., Xeromyces spp.. Twenty-two of 41 identified mould species were potentially toxigenic, which accounted for 46.18% of the total isolated population. The most frequent were the potential producers of ochratoxin A (17.77%. Potential producers of moniliformin were isolated in 3.11% of samples, while producers of fumonisin and STC were found in 2.67% and 2.44% of samples, respectively. The tested isolates of OA producers did not demonstrate the ability to biosynthetise this mycotoxins, but two out of five isolates of A. versicolor were found to biosynthesise STC in doses of 109.2 ng mL-1 and 56.3 ng mL-1. The obtained results indicate that such products may threaten human health, considering that isolated species were potentially toxigenic, while isolates of A. versicolor also biosynthesised STS.

  9. A novel and inexpensive technique for creating superhydrophobic surfaces using Teflon and sandpaper

    Science.gov (United States)

    Nilsson, Michael A.; Daniello, Robert J.; Rothstein, Jonathan P.

    2010-02-01

    Considerable efforts have been spent over the last decade developing hydrophobic surfaces exhibiting very large contact angles with water. Many of these methods require complex and expensive fabrication techniques. We demonstrate that sanding Teflon can produce superhydrophobic surfaces with advancing contact angles of up to 151° and contact angle hysteresis of less than 4°. Furthermore, we show that a wide range of both advancing contact angles and contact angle hysteresis can be achieved by varying the grit size of the sandpaper, allowing for future hysteresis and contact angle studies. Scanning electron microscopy images of the roughened surfaces depict the range and amplitude of length scales imparted on the surface by the sandpaper, which leads to deeper understanding of the state of wetting on the surface.

  10. 42 CFR 137.325 - What does a Self-Governance Tribe do if it wants to perform a construction project under section...

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false What does a Self-Governance Tribe do if it wants to..., DEPARTMENT OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Construction Project Assumption Process § 137.325 What does a Self-Governance Tribe do if it wants to perform a construction project under section...

  11. Development of quality assurance procedures for thermoluminescent CaSO sub 4 :Dy-teflon skived tape dosemeter

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, J.S.; Popli, K.L.; Kher, R.K.; Varadharajan, G. (Bhabha Atomic Research Centre, Bombay (India). Div. of Radiological Protection)

    1992-01-01

    CaSO{sub 4}:Dy-Teflon TLD dosemeter material has been manufactured locally in a 0.4 mm thick continuous tape form. Fourteen batches have been examined for physical thickness, density, spectral transmission, diffuse optical density, beta transmission and TL output per unit area for evolving a procedure for quality assurance of the TLD element for large scale production. With the exception of two batches, the TL output per unit area of the tape for a number of batches lies within {+-}7% of that for a standard batch. (author).

  12. Constructing an ‘Outlandish’ Narrative of Self: The Role of Music in Muslim Experience

    Directory of Open Access Journals (Sweden)

    Reem M Hilal

    2015-07-01

    Full Text Available This paper explores the way in which Muslims, particularly those in the Diaspora, use music as an alternative medium to negotiate a narrative of self that reflects their performance of their faith and the issues that concern them. The focus will be on the music of the Danish based music group Outlandish. Specifically, music has become an important space to dismantle and reformulate discussions on identity and offers insight into the way language, religion, and resistance are deployed in a medium with increasing currency. Outlandish has garnered an international audience; through mediums such as YouTube, their music resonates with Muslims and other minority groups in the diaspora faced with similar issues of identification. This paper addresses the questions: how is music employed to construct narratives of self that challenge boundaries? How does music engage the issue of representation for those who face exclusion? How can their work be read in the contemporary setting where globalization has brought different cultural worldviews into contact, at times producing dialogue and constructive exchange and at other times leading to discernible violence, engendering a more pronounced sense of alienation and exclusion? Through their music, Outlandish expresses the ways in which what differentiates between people binds them through a process of recognition, to borrow from Judith Butler. Focusing on Outlandish’s music, I examine the role of music in the negotiation and construction of narratives of self by contemporary Muslims that counter those that have been constructed for and against them.

  13. Optical and electrical properties of ion beam textured Kapton and Teflon

    Science.gov (United States)

    Mirtich, M. J.; Sovey, J. S.

    1977-01-01

    An electron bombardment argon ion source was used to ion etch polyimide (Kapton) and fluorinated ethylene, FEP (Teflon). Samples of polyimide and FEP were exposed to (0.5-1.0) keV Ar ions at ion current densities of (1.0-1/8) mA/sq cm for various exposure times. Changes in the optical and electrical properties of the samples were used to characterize the exposure. Spectral reflectance and transmittance measurements were made between 0.33 and 2.16 micron m using an integrating sphere after each exposure. From these measurements, values of solar absorptance were obtained. Total emittance measurements were also recorded for some samples. Surface resistivity was used to determine changes in the electrical conductivity of the etched samples. A scanning electron microscope recorded surface structure after exposure. Spectral optical data, resistivity measurements, calculated absorptance and emittance measurements are presented along with photomicrographs of the surface structure for the various exposures to Ar ions.

  14. Improved moulding material for addition to nuclear fuel particles to produce nuclear fuel elements

    International Nuclear Information System (INIS)

    Miertschin, G.N.; Leary, D.F.

    1976-01-01

    A suggestion is made to improve the moulding materials used to produce carbon-contained nuclear fuel particles by a coke-reducing added substance. The nuclear fuel particles are meant for the formation of fuel elements for gas-cooled high-temperature nuclear reactors. The moulding materials are above all for the formation of coated particles which are burnt in situ in nuclear fuel element chambers out of 'green' nuclear fuel bodies. The added substance improves the shape stability of the particles forming and prevents a stiding or bridge formation between the particles or with the surrounding walls. The following are named as added substances: 1) Polystyrene and styrene-butadiene-Co polymers (mol. wt. between 5oo and 1,000,000), 2) aromatic compounds (mol. wt. 75 to 300), 3) saturated hydrocarbon polymers (mol. wt. 5,000 to 1,000,000). Additional release agents further improve the properties in the same direction (e.g. alcohols, fatty acids, amines). (orig.) [de

  15. Spergilli on Building Partitions Infested with Moulds in Residential Housing and Public Utility Premises

    Science.gov (United States)

    Piontek, Marlena; Łuszczyńska, Katarzyna; Lechów, Hanna

    2017-12-01

    Aspergilli constitute a serious risk to the health of the inhabitants of infested rooms. Mycological analysis conducted in buildings infected with moulds in the area of the Lubuskie province (Poland) demonstrated the presence of 9 species of Aspergillus moulds: A. carbonarius A. clavatus, A. flavus, A. fumigatus, A. niger, A. ochraceus, A. terreus, A ustus and A. versicolor. The highest frequency (4 - frequently) was observed in the case of A. versicolor, while frequency 3 (fairly frequently) was characteristic of such species as A. flavus and A. niger. A. ustus was encountered with frequency 2 (individually), while frequency 1 (sporadically) referred to four species: A. carbonarius, A. clavatus, A. fumigatus and A. terreus. Because Aspergillus versicolor occurs with the highest frequency in buildings, and as a consequence of this, synthesizes toxic and carcinogenic sterigmatocystin (ST), it constitutes the greatest risk to the inhabitants of the infested premises. All species of Aspergillus present on building partitions are able to synthesise mycotoxins, are pathogens and may cause allergies.

  16. Effect of bentonite addition on residual strength of microwave-hardened waterglass-containing moulding sands

    Directory of Open Access Journals (Sweden)

    M. Stachowicz

    2011-07-01

    Full Text Available The paper presents results of a preliminary research of the effect of bentonite addition on residual strength of microwave-hardened moulding sands, containing sodium waterglass. Strength was determined at ambient temperature, on cylindrical specimens baked in an oven. Moulding sands for examinations were based on high-silica sand with addition of 2.5 % of non-modified, domestic-made waterglass grade 145. The prepared standard cylindrical specimens were hardened using the innovative microwave heating process and next baked for 30 minutes at temperatures between 100 and 1200 °C. Strength parameters of the specimens were determined on the specimens cooled- down to ambient temperature. The obtained results were compared with literature data to evaluate the effect of the applied hardening method and of the special additive on residual strength as a function of baking temperature. A favourable effect was found of both the innovative heating process and the applied bentonite addition.

  17. Microstructure and mechanical properties of TiAl castings produced by zirconia ceramic mould

    Directory of Open Access Journals (Sweden)

    Tian Jing

    2011-11-01

    Full Text Available Owing to their low density and attractive high-temperature properties, gamma titanium aluminide alloys (TiAl alloys, hereafter have significant potential application in the aerospace and automobile industries, in which these materials may replace the heavier nickel-based superalloys at service temperatures of 600 – 900℃. Investment casting of TiAl alloys has become the most promising cost-effective technique for the manufacturing of TiAl components. Ceramic moulds are fundamental to fabricating the TiAl casting components. In the present work, ceramic mould with a zirconia primary coat was designed and fabricated successfully. Investment casting of TiAl blades and tensile test of specimens was carried out to verify the correctness and feasibility of the proposed method. The tensile test results indicate that, at room temperature, the tensile strength and the elongation are about 450 MPa and 0.8%, respectively. At 700℃, the tensile strength decreases to about 410 MPa and the elongation increases to 2.7%. Microstructure and mechanical properties of investment cast TiAl alloy are discussed.

  18. Effect of ethanol on growth of Chrysonilia sitophila ('the red bread mould') and Hyphopichia burtonii ('the chalky mould') in sliced bread.

    Science.gov (United States)

    Berni, E; Scaramuzza, N

    2013-10-01

    Contamination of food industrial environments and recontamination of finished products by Chrysonilia sitophila and Hyphopichia burtonii have long represented serious problems for the bakery industries. As one of the most common ways to slow down or avoid fungal spoilage on bakery products is the use of ethanol, in the present work the effect of this substance has been assessed on growth of two of the most frequently occurring associated moulds, C. sitophila and H. burtonii, by means of tests on both synthetic media and sliced bread. Test on synthetic media: H. burtonii was less markedly affected in lag-phase duration and radial growth rates by the addition of ethanol to DG18 and the reduction in incubation temperature than C. sitophila that failed to grow at the highest concentrations of ethanol tested (2·0 and 4·0% at 15°C; 4·0% at 25°C). Test on sliced bread: ethanol proved to be effective to prevent spoilage by C. sitophila even at the lowest concentration tested (0·8%, w/w), while higher concentrations (2·0%, w/w) were needed to prevent spoilage by H. burtonii. This study shows that ethanol could represent an effective barrier to prevent spoilage of bakery products by associated moulds such as Chrysonilia sitophila and Hyphopichia burtonii, whose growth on packed and sliced bread was inhibited at very low (0·8%) or medium (2·0%) ethanol concentrations, respectively. The results obtained represent a fundamental point of reference for the bakery industries, as they can apply them in the productive practice to avoid spoilage by C. sitophila and H. burtonii on their products. © 2013 The Society for Applied Microbiology.

  19. Effect of moulding on the changes in chemical composition of tabacco leaves

    Directory of Open Access Journals (Sweden)

    Krystyna Florczak

    2014-08-01

    Full Text Available The process of moulding caused by the fungi: Aspergillus repens (Cda. De Bart, Aspergillus flavus Link, Aspergillus ochraceus Wilhelm, Penicillium expansum (Link Thom, VPenicillium commune Thom and Penicillum spinulosum Tom influenced the decrease in soluble carbohydrate content with the simulataneous increase in the percentage of specific protein. It had an effect on the deterioration of technological and taste values of raw tabacco.

  20. Volumetric water content measurement probes in earth-dam construction

    Directory of Open Access Journals (Sweden)

    Bardanis Michael

    2016-01-01

    Full Text Available Two frequency domain reflectometry (FDR probes have been used. They were used on compacted soils both in the laboratory and in the field. Measurements in the laboratory were intended for calibration. The range of densities and types of materials where insertion of the probes can be achieved was investigated first. The effect of sporadic presence of coarser grains and density on these calibrations, once insertion could be achieved, were investigated second. Measurements on laboratory prepared samples with the same moisture content were different when the sample was kept in the mould from when it was extruded from it. Also both these measurements were different from that in a sample of the same density but significantly larger in diameter. It was found that measurements with these probes are affected by dilation exhibited by soil around the rods of the probes during insertion. Readings immediately after insertion of the sensors on samples extruded from their moulds were the ones closer to measured values. These readings combined with total volume and mass obtained from sand-cone tests during the construction of an earth-dam allowed fairly accurate estimation of the dry unit weight but not the gravimetric water content.

  1. [Effects of 33% grapefruit extract on the growth of the yeast--like fungi, dermatopytes and moulds].

    Science.gov (United States)

    Krajewska-Kułak, E; Lukaszuk, C; Niczyporuk, W

    2001-01-01

    Grapefruit seed extract was discovered by Jacob Harich an american immunologist in 1980. Assessment of the influence of grapefruit extract on the yeast-like fungi strains--Candida albicans growth. Material used in this investigation was ATCC test Candida albicans strains no 10231, 200 of Candida albicans strains, 5 of Candida sp. strains isolated from patients with candidiasis symptoms from different ontocenosis and 12 of dermatophytes and moulds isolated from patients. The susceptibility of the Candida was determined by serial dilution method. It seems that 33% grapefruit extract exert a potent antifungal activity against the yeast like fungi strains and had low activity against dermatophytes and moulds. Further studies in vitro and in vivo on greater number of the yeast-like fungi strains and other fungi species are needed.

  2. Experimental investigation of the factors influencing the polymer-polymer bond strength during two-component injection moulding

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Bondo, Martin

    2010-01-01

    Two-component injection moulding is a commercially important manufacturing process and a key technology for combining different material properties in a single plastic product. It is also one of most industrially adaptive process chain for manufacturing so-called moulded interconnect devices (MIDs......). Many fascinating applications of two-component or multi-component polymer parts are restricted due to the weak interfacial adhesion of the polymers. A thorough understanding of the factors that influence the bond strength of polymers is necessary for multi-component polymer processing. This paper...... investigates the effects of the process conditions and geometrical factors on the bond strength of two-component polymer parts and identifies the factors which can effectively control the adhesion between two polymers. The effects of environmental conditions on the bond strength are also investigated...

  3. DIRECTIONS OF IMPROVING SELF-REGULATING SYSTEM IN CONSTRUCTION IN THE CONTEXT OF THE THEORY OF CHANGE

    Directory of Open Access Journals (Sweden)

    Uvarova Svetlana Sergeevna

    2016-08-01

    Full Text Available Self-regulation in construction is characterized by a number of essential disadvantages, which reduce its efficiency. The authors justify scientific and methodological base of self-regulation, which includes the elements of the theory of change and self-organization. Introduction of self-regulation is considered as organizational and economical change, the life cycle of which is an implementation process of the projects of change. According to the lifecycle, key problem zones of self-regulation process are determined and a number of required economical and institutional changes are offered.

  4. The non-display of authentic distress: public-private dualism in young people's discursive construction of self-harm.

    Science.gov (United States)

    Scourfield, Jonathan; Roen, Katrina; McDermott, Elizabeth

    2011-07-01

    This article draws from focus groups and interviews investigating how young people talk about self-harm. Some of the research participants had personal experience of self-harm but this was not a prerequisite for their inclusion in the study. Thematic coding was used initially to organise and give an overview of the data, but the data were subsequently analysed using a discourse analytic approach. The article focuses on the young people's constructions of deliberate self-harm such as 'cutting'. Throughout the focus groups and interviews, a dichotomy was set up by the young people between authentic, private self-harm which is rooted in real distress (and warrants a sympathetic response) and public, self-indulgent attempts to seek attention. This dualistic construction is discussed in some detail and located in various socio-cultural contexts. It is argued that the dualism illustrates contemporary ambivalence about mental health and youth. © 2011 The Authors. Sociology of Health & Illness © 2011 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

  5. Grey mould development in greenhouse tomatoes under drip and furrow irrigation

    OpenAIRE

    Aissat , Kamel; Nicot , Philippe ,; Guechi , Abdelhadi; Bardin , Marc; Chibane , Mohamed

    2008-01-01

    Several methods can be used to provide water to plants in cropping systems where irrigation is necessary. For instance, drip irrigation has recently received much attention due to its advantages for water conservation. The type of irrigation can also impact the development of several pathogens responsible for soilborne diseases. Here, we studied the effect of drip irrigation and furrow irrigation on the development of grey mould, caused by the airborne fungus Botrytis cinerea, on tomato plant...

  6. INFLUENCE OF REGRIND ON PROPERTIES OF PLASTICS PRODUCED BY INJECTION MOULDING

    Directory of Open Access Journals (Sweden)

    Ľudmila Dulebová

    2011-07-01

    Full Text Available The contribution deals with the evaluation of results of selected mechanical tests. Materials Crastin® PBT (with 30 % glass fibre and Celanex® 2004-2 PBT (without filler were used at tests with various percentage of added regrind into basic material. The mechanical properties were obtained by tensile test and Shore hardness test. Utilization of regrind at the production of new moulded parts is important from aspect of reduction plastics waste and pollution abatement of environment.

  7. Simultaneous Replication of both Refractive and Diffractive Optical Components using Electroformed Tools and Injection Moulding

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Christensen, Thomas R.

    2003-01-01

    This research project has demonstrated that with carefully selected processes it is possible to fabricate tools for injection moulding of both diffractive and refractive optical components. The fabrication procedure is based on an aluminium disc on which selected optical components (gratings and ...

  8. Modelling the deformation of nickel foil during manufacturing of nanostructures on injection moulding tool inserts

    DEFF Research Database (Denmark)

    Sonne, Mads Rostgaard; Cech, Jiri; Pranov, H.

    2016-01-01

    In the present work, a manufacturing process for transferring nanostructures from a glass wafer, to a double-curvedinsert for injection moulding is demonstrated. A nanostructure consisting of sinusoidal cross-gratings with a period of 426 nm issuccessfully transferred to hemispheres on an aluminium...

  9. THE OCCURRENCE OF INSECTS AND MOULDS IN STORED COCOA BEANS AT SOUTH SULAWESI

    Directory of Open Access Journals (Sweden)

    OKKY S. DHARMAPUTRA

    1999-01-01

    Full Text Available Surveys on postharvest handling and technology processing of cocoa beans at farmer, trader and exporter levels in South Sulawesi were conducted together with investigations on moisture content, pest infestation (insect and mould and quality characteris tics in terms of reducing sugar, free amino acid and free fatty acid content. Surveys were conducted during dry (July 1997 and wet seasons (February 1998 in three regencies (Pinrang, Polewali-Mamasa and Luwu and Ujung Pandang, South Sulawesi province. Interviews were carried out during surveys in the dry season. Number of respondents from farmers, trailers and exporters was 38, 15 and 5, respectively. In each season, number of samples taken from farmers, traders and exporters was 9, 21 and 15, respectively. In general, farmers, traders and exporters did not carry out postharvest handling and technology processing properly. Moisture content of cocoa beans collected from farmers, traders and exporters were higher than the tolerabl e limit recommended by SNI (7.5%. Moisture content of cocoa beans collected during the wet season was higher than in the dry season. Insects were found on cocoa beans collected from traders and exporters. Species composition and the presence of each insect species were varied among the two seasons, but the predominant species was Tribolium castaneum. At trader level the percentage of insect-damaged beans during the wet season was higher than that during the dry season, while at exporter le vel it was lower. During the two seasons the percentage of mouldy beans at farmer level was lower than the tolerable limit recommended by SNI (4%, while those from some samples at trader and exporter levels were higher than 4%, but based on the direct plating method, all of the samples at trader and exporter levels were mouldy. Species composition and the percentage of beans infected by each mould species at farmer, trader and exporter levels during the two seasons were va ried. The

  10. Inhibition of ochratoxigenic moulds by Debaryomyces hansenii strains for biopreservation of dry-cured meat products

    DEFF Research Database (Denmark)

    Andrade, Maria J.; Thorsen, Line; Rodríguez, Alicia

    2014-01-01

    mould growth and OTA accumulation in dry-cured meat products. The inoculation of D. hansenii should be made at the beginning of processing (at the end of post salting) when the a(w) of the product is still high (near 0.94). This action in addition to application of appropriate hygienic actions......The ability of the osmotolerant yeast Debaryomyces hansenii to inhibit Penicillium nordicum, the most common ochratoxigenic mould encountered in dry-cured meat products, was evaluated. The antagonistic effect of ten D. hansenii strains isolated from dry-cured ham was screened in vitro using malt...... extract media and meat extract peptone media with the water activity (a(w)) adjusted to 0.97 and 0.90. A significant inhibition of the two tested P. nordicum strains by D. hansenii cells and cell-free supernatants was observed. At 0.97 a(w), increasing D. hansenii inoculum concentrations significantly...

  11. A new construction technique for tissue-engineered heart valves using the self-assembly method.

    Science.gov (United States)

    Tremblay, Catherine; Ruel, Jean; Bourget, Jean-Michel; Laterreur, Véronique; Vallières, Karine; Tondreau, Maxime Y; Lacroix, Dan; Germain, Lucie; Auger, François A

    2014-11-01

    Tissue engineering appears as a promising option to create new heart valve substitutes able to overcome the serious drawbacks encountered with mechanical substitutes or tissue valves. The objective of this article is to present the construction method of a new entirely biological stentless aortic valve using the self-assembly method and also a first assessment of its behavior in a bioreactor when exposed to a pulsatile flow. A thick tissue was created by stacking several fibroblast sheets produced with the self-assembly technique. Different sets of custom-made templates were designed to confer to the thick tissue a three-dimensional (3D) shape similar to that of a native aortic valve. The construction of the valve was divided in two sequential steps. The first step was the installation of the thick tissue in a flat preshaping template followed by a 4-week maturation period. The second step was the actual cylindrical 3D forming of the valve. The microscopic tissue structure was assessed using histological cross sections stained with Masson's Trichrome and Picrosirius Red. The thick tissue remained uniformly populated with cells throughout the construction steps and the dense extracellular matrix presented corrugated fibers of collagen. This first prototype of tissue-engineered heart valve was installed in a bioreactor to assess its capacity to sustain a light pulsatile flow at a frequency of 0.5 Hz. Under the light pulsed flow, it was observed that the leaflets opened and closed according to the flow variations. This study demonstrates that the self-assembly method is a viable option for the construction of complex 3D shapes, such as heart valves, with an entirely biological material.

  12. Growth and decay of surface charges in grafts of Teflon in electrets states

    International Nuclear Information System (INIS)

    Spinelli, I.M.M.

    1971-01-01

    The greatest problem founded in a cardiovascular implant is the thrombus formation. Teflon grafts were used in electret state for prothesis in vena cava of dogs. To put these grafts in an electret state a corona discharge in air was used and homocharge was formed predominantly. To measure the formed surface charge the oscillating capacitor technique was used. In the electret state the grafts have showed an initial density of charge of 10- 8 C/cm 2 and the charge decay and time decay of the samples were measured under many conditions. We found two activation energies, E 2 =0.17 e V and E 3 =1.12 e V, due to rapid and slow decay, respectively. The charged grafts were sterilized with ethilene gas oxide and this process apparently did not influence the charges

  13. Comparison of stapes prostheses: a retrospective analysis of individual audiometric results obtained after stapedotomy by implantation of a gold and a teflon piston

    NARCIS (Netherlands)

    de Bruijn, A. J.; Tange, R. A.; Dreschler, W. A.

    1999-01-01

    PURPOSE: Evaluation of hearing results after implantation of a Teflon piston (type Causse; Xomed Surgical Products, Jacksonville, FL) and of a pure gold piston (K-piston; Heinz Kurz GmbH Medizintechnik, Dusslingen, Germany), both with a shaft diameter of 0.4 mm in cases of otosclerosis requiring

  14. A Market Equilibrium Supply Chain Model for Supporting Self-Manufacturing or Outsourcing Decisions in Prefabricated Construction

    Directory of Open Access Journals (Sweden)

    Yanhu Han

    2017-11-01

    Full Text Available Prefabricated construction is a sustainable alternative to traditional on-site construction methods. However, many challenges still exist in the prefabricated construction process. For example, self-manufacturing or outsourcing decisions are vital to the industrial structure and organization of the prefabricated construction industry, and the company’s production and operation decision-making. This paper considers a prefabricated construction supply chain, which is composed of one upstream component manufacturing company and two downstream contractors. The large contractor can get the precast component through self-manufacturing or outsourcing, while the small and medium-sized enterprise (SME contractor can only buy components from the component manufacturer. A comprehensive game model (Cournot-Stackelberg model under different decisions, that is, component self-manufacturing or outsourcing, was established. By solving the profit functions of different companies in the prefabricated construction supply chain, the equilibrium solutions of output, price and profit can be achieved. These solutions of equilibrium indicate the optimal decision on the production and operation, and the profit’s boundary conditions. After assuming relevant parameters, the profit levels of the companies in the supply chain are analyzed via a dynamic simulation in the changing process of prefabricated construction market size under different behavioral decisions. The conclusions are as follows: (1 the profit levels of all supply chain enterprises and the whole supply chain are increasing with an increase of market size; (2 the downstream contractors and the whole supply chain have a higher profit level under the component self-manufacturing decision, however, on the contrary, the upstream component suppliers get a higher profit level under the component outsourcing decision; (3 the equilibrium output of the SME contractor is reduced under the outsourcing decision of

  15. High-yield acetonitrile | water triple phase boundary electrolysis at platinised Teflon electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, John D.; MacDonald, Stuart M.; Fordred, Paul S.; Bull, Steven D. [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Gu, Yunfeng; Yunus, Kamran; Fisher, Adrian C. [Department of Chemical Engineering, University of Cambridge, New Museums Site, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Bulman-Page, Philip C. [School of Chemistry, University of East Anglia, Norwich, Norfolk NR4 7TJ (United Kingdom); Marken, Frank [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)], E-mail: f.marken@bath.ac.uk

    2009-11-30

    A dynamic acetonitrile | aqueous electrolyte phase boundary in contact with platinised Teflon working electrodes is investigated. High concentrations of salt in the aqueous phase (2 M NaCl and 0.1 M NaClO{sub 4}) ensure immiscibility and the polar nature of acetonitrile aids the formation of a well-behaved triple phase boundary reaction zone. The one-electron oxidation of tert-butylferrocene in the organic phase without intentionally added electrolyte is studied. The limiting current for the flowing triple phase boundary process is shown to be essentially volume flow rate independent. The process is accompanied by the transfer of perchlorate from the aqueous into the organic phase and the flux of anions is shown to be approximately constant along the dynamic acetonitrile | aqueous electrolyte | platinum line interface. A high rate of conversion (close to 100%) is achieved at slow volume flow rates and at longer platinum electrodes.

  16. Differential Control Efficacies of Vitamin Treatments against Bacterial Wilt and Grey Mould Diseases in Tomato Plants

    Directory of Open Access Journals (Sweden)

    Jeum Kyu Hong

    2016-10-01

    Full Text Available Bacterial wilt and grey mould in tomato plants are economically destructive bacterial and fungal diseases caused by Ralstonia solanacearum and Botrytis cinerea, respectively. Various approaches including chemical and biological controls have been attempted to arrest the tomato diseases so far. In this study, in vitro growths of bacterial R. solanacearum and fungal B. cinerea were evaluated using four different vitamins including thiamine (vitamin B1, niacin (vitamin B3, pyridoxine (vitamin B6, and menadione (vitamin K3. In planta efficacies of the four vitamin treatments on tomato protection against both diseases were also demonstrated. All four vitamins showed different in vitro antibacterial activities against R. solanacearum in dose-dependent manners. However, treatment with 2 mM thiamine was only effective in reducing bacterial wilt of detached tomato leaves without phytotoxicity under lower disease pressure (10⁶ colony-forming unit [cfu]/ml. Treatment with the vitamins also differentially reduced in vitro conidial germination and mycelial growth of B. cinerea. The four vitamins slightly reduced the conidial germination, and thiamine, pyridoxine and menadione inhibited the mycelial growth of B. cinerea. Menadione began to drastically suppress the conidial germination and mycelial growth by 5 and 0.5 mM, respectively. Grey mould symptoms on the inoculated tomato leaves were significantly reduced by pyridoxine and menadione pretreatments one day prior to the fungal challenge inoculation. These findings suggest that disease-specific vitamin treatment will be integrated for eco-friendly management of tomato bacterial wilt and grey mould.

  17. Differential Control Efficacies of Vitamin Treatments against Bacterial Wilt and Grey Mould Diseases in Tomato Plants.

    Science.gov (United States)

    Hong, Jeum Kyu; Kim, Hyeon Ji; Jung, Heesoo; Yang, Hye Ji; Kim, Do Hoon; Sung, Chang Hyun; Park, Chang-Jin; Chang, Seog Won

    2016-10-01

    Bacterial wilt and grey mould in tomato plants are economically destructive bacterial and fungal diseases caused by Ralstonia solanacearum and Botrytis cinerea , respectively. Various approaches including chemical and biological controls have been attempted to arrest the tomato diseases so far. In this study, in vitro growths of bacterial R. solanacearum and fungal B. cinerea were evaluated using four different vitamins including thiamine (vitamin B1), niacin (vitamin B3), pyridoxine (vitamin B6), and menadione (vitamin K3). In planta efficacies of the four vitamin treatments on tomato protection against both diseases were also demonstrated. All four vitamins showed different in vitro antibacterial activities against R. solanacearum in dose-dependent manners. However, treatment with 2 mM thiamine was only effective in reducing bacterial wilt of detached tomato leaves without phytotoxicity under lower disease pressure (10 6 colony-forming unit [cfu]/ml). Treatment with the vitamins also differentially reduced in vitro conidial germination and mycelial growth of B. cinerea . The four vitamins slightly reduced the conidial germination, and thiamine, pyridoxine and menadione inhibited the mycelial growth of B. cinerea . Menadione began to drastically suppress the conidial germination and mycelial growth by 5 and 0.5 mM, respectively. Grey mould symptoms on the inoculated tomato leaves were significantly reduced by pyridoxine and menadione pretreatments one day prior to the fungal challenge inoculation. These findings suggest that disease-specific vitamin treatment will be integrated for eco-friendly management of tomato bacterial wilt and grey mould.

  18. Suitability of a South African silica sand for three-dimensional printing of foundry moulds and cores

    Directory of Open Access Journals (Sweden)

    Nyembwe, Kasongo

    2016-11-01

    Full Text Available Applications of three-dimensional printing (3DP to metal casting include, among other things, the direct manufacturing of foundry moulds and cores in refractory materials such as silica sand. The main properties of silica sand that are essentially related to the traditional moulding and core-making processes are: size distribution, clay content, pH, acid demand, and refractoriness. The silica sand used for 3DP must also be appropriately selected for the layer-based manufacturing process involved in 3DP. Properties such as grain size distribution, grain surface morphology, angularity, flowability, and recoating abilities have a particular importance when determining sand suitability. Because of these extra requirements, only a limited range of available foundry silica sands can be used for 3DP processes. The latter situation explains the scarcity and high cost of suitable silica sands, thus contributing to the relatively high operational costs of the 3DP processes for the production of sand moulds and cores. This research paper investigates the suitability of a locally-available silica sand for use in a Voxeljet VX1000 3DP machine. The local silica sand was assessed and compared with an imported silica sand recommended by the manufacturer of 3DP equipment in terms of foundry characteristics and recoating behaviour. The study shows that, despite the differences between the characteristics of the two silica sands, the local sand could be considered a suitable alternative to imported sand for rapid sand casting applications.

  19. Renovation and design of double casement windows with regard to the occurrence of water vapour condensation or mould on the interior surface of the window jamb

    Science.gov (United States)

    Kudrnacova, L.; Balik, L.

    2017-10-01

    The condensation of water vapour on the interior surface is an indicator of construction dysfunction or ignoring of the surroundings temperature and relative humidity. This paper deals with analysis of the occurrence of condensation on the jamb of double casement windows (windows with two window casements). More precisely, this is a surface in the interior where water vapour condensation or mould occur. For the renovation of existing double casement windows, there are different solutions based on window design: application of double insulating glazing on the interior window casement, application of double insulating glazing on the exterior casement, or installation of a simple window. We first describe measurement of an existing double casement window located in a mountain cottage. Second, the results and comparison of 2D thermal model of different types of double casement window construction. Also, the external insulation of the peripheral wall was included in the model.

  20. Effects of phosphor proportion and grain size on photon energy response of CaSO4:Dy teflon TLD discs

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Bhatt, R.C.

    1979-01-01

    Effects of phosphor proportion and grain size on the photon energy dependence of CaSO 4 :Dy embedded teflon TLD discs have been studied. It was found that in the commonly used TLD disc compositions, the proportion of phosphor has only little effect on energy dependence. This dependence could be significantly reduced by using phosphor of grain size less than 1 μm. The experimental results are compared with calculated results. (Auth.)