WorldWideScience

Sample records for plasmodial slime molds

  1. On the role of the plasmodial cytoskeleton in facilitating intelligent behavior in slime mold Physarum polycephalum

    Science.gov (United States)

    Mayne, Richard; Adamatzky, Andrew; Jones, Jeff

    2015-01-01

    The plasmodium of slime mold Physarum polycephalum behaves as an amorphous reaction-diffusion computing substrate and is capable of apparently ‘intelligent’ behavior. But how does intelligence emerge in an acellular organism? Through a range of laboratory experiments, we visualize the plasmodial cytoskeleton—a ubiquitous cellular protein scaffold whose functions are manifold and essential to life—and discuss its putative role as a network for transducing, transmitting and structuring data streams within the plasmodium. Through a range of computer modeling techniques, we demonstrate how emergent behavior, and hence computational intelligence, may occur in cytoskeletal communications networks. Specifically, we model the topology of both the actin and tubulin cytoskeletal networks and discuss how computation may occur therein. Furthermore, we present bespoke cellular automata and particle swarm models for the computational process within the cytoskeleton and observe the incidence of emergent patterns in both. Our work grants unique insight into the origins of natural intelligence; the results presented here are therefore readily transferable to the fields of natural computation, cell biology and biomedical science. We conclude by discussing how our results may alter our biological, computational and philosophical understanding of intelligence and consciousness. PMID:26478782

  2. DIVERSITY AND DISTRIBUTION OF PLASMODIAL MYXOMYCETES (SLIME MOLDS FROM LA MESA ECOPARK, QUEZON CITY, PHILIPPINES

    Directory of Open Access Journals (Sweden)

    THOMAS EDISON E. DELA CRUZ

    2010-10-01

    Full Text Available Myxomycetes are ubiquitous in terrestrial forest ecosystems. Thus, this research study looks at the taxonomic diversity and distribution of plasmodial myxomycetes in La Mesa Ecopark in Quezon City, Philippines. A total of 240 moist chambers were prepared from four substrates (aerial and ground leaf litter, twigs and barks collected within this ecopark. Following incubation of moist chambers for eight weeks, a total of 28 species belonging to 10 genera were collected and identified: Arcyria (3, Diderma (2, Didymium (5, Lamproderma (2, Perichaena (3, Physarum (8, Macbrideola (1, Metatrichia (1, Trichia (1 and Stemonitis (2. Highest myxomycete yield (85% was observed in aerial leaf litter. In terms of taxonomic diversity, highest diversity was observed in bark microhabitats, although the lowest number of species was recorded in it. Assessment of their abundance and distribution showed similarities in species composition between aerial and ground leaf litter. This research study is the first report of plasmodial myxomycetes in La Mesa Ecopark in Quezon City, Philippines.

  3. Ozone reaction on slime mold. [Physarum polycephalum

    Energy Technology Data Exchange (ETDEWEB)

    Kanoh, F.

    1972-01-01

    To determine the effect of ozone, the motive force responsible for protoplasmic streaming in the slime mold, Physarum polycephalum was measured by the Double chamber method which was developed by Kamiya. The effects of ozone on the motive force were investigated by comparison of the Dynamoplasmogram of controls with that of ozone exposure. In the case of high concentration exposure, thickening of plasmagel, inversion of the period of flow and reduction of the extreme point were observed. Succinoxidase of exposed homogenates showed stronger activity than that of controls. It is certain that the Pasteur reaction takes place when plasmodium is kept under high ozone exposure condition. It appears that ozone inhibited a part of the process of glycolysis. 32 references, 8 figures.

  4. Potential sites for the perception of gravity in the acellular slime mold Physarum polycephalum.

    Science.gov (United States)

    Block, I; Briegleb, W

    1989-01-01

    Recently a gravisensitivity of the acellular slime mold Physarum polycephalum, which possesses no specialized gravireceptor, could be established by conducting experiments under simulated and under real near weightlessness. In these experiments macroplasmodia showed a modulation of their contraction rhythm followed by regulation phenomena. Until now the perception mechanism for the gravistimulus is unknown, but several findings indicate the involvement of mitochondria: A) During the impediment of respiration the 0g-reaction is inhibited and the regulation is reduced. B) The response to a light stimulus and the following regulation phenomena strongly resemble the behavior during exposure to 0g, the only difference is that the two reactions are directed into opposite directions. In the blue-light reaction a flavin of the mitochondrial matrix seems to be involved in the light perception. C) The contraction rhythm as well as its modulations are coupled to rhythmic changes in the levels of ATP and calcium ions, involving the mitochondria as sites of energy production and of Ca(++)-storage. So the mitochondria could be the site of the regulation and they possibly are the receptor sites for the light and gravity stimuli. Also the observation of a morphologic polarity of the slime mold's plasmodial strands has to be considered: Cross-sections reveal that the ectoplasmic wall surrounding the streaming endoplasm is much thinner on the physically lower side than on the upper side of the strand--this applies to strands lying on or hanging on a horizontal surface. So, in addition to the mitochondria, also the morphologic polarity may be involved in the perception mechanism of the observed gravisensitivity and of the recently established geotaxis. The potential role of the nuclei and of the contractile elements in the perception of gravity is also discussed.

  5. Chemotaxis in the cellular slime molds : I. The effect of temperature

    NARCIS (Netherlands)

    Konijn, Theo M.

    1965-01-01

    The effect of temperature on chemotaxis in the cellular slime mold Dictyostelium discoideum has been studied by incubating small populations of washed myxamoebae at different temperatures. Droplets containing a cell suspension of known density were deposited on a hydrophobic agar surface. The

  6. Cytochemical study of the nucleolus of the slime mold Dictyostelium discoideum

    International Nuclear Information System (INIS)

    Benichou, J.C.; Quiviger, B.; Ryter, A.

    1983-01-01

    The nucleus of the slime mold Dictyostelium discoideum is characterized by the presence of several large dense masses which are all in tight contact with the nuclear membrane. These dense masses, considered as nucleoli, present a rather homogeneous texture, in which dense chromatin, fibrillar, and granular material are not easily detected. The autoradiographic study of [ 3 H]uridine pulse-labeled cells showed that the majority of the silver grains were located inside these masses. The use of EDTA regressive-staining, acetylation and enzymatic digestion indicated that they are mostly composed of RNP and are totally devoid of dense chromatin as the rest of the nucleus is. After treatment with actinomycin D, fibrillar and granular material segregated but no chromatin could be found. All these observations confirmed that the dense masses correspond to nucleoli despite their peculiar ultrastructure. It can also be concluded that this type of nucleoli cannot be considered as a taxonomic character of the slime molds because it does not exist in all slime molds and was observed in some dinoflagellates, and ascomycetes

  7. Principles of minimal cognition in smart slime molds and social bacteria

    Directory of Open Access Journals (Sweden)

    Óscar Castro García

    2013-07-01

    Full Text Available The perception of the environment as well as sensorimotor coordination of unicellularsorganisms competence as the foundation of a cognitive principle that goes beyond minimum metabolicprocesses. I study the recognition of the environment in case of slime mold and bacteria as significantlearning processes in differentiating between hostile environment or optimal and physical transformationsof each agency on the basis of received signals in both the membrane and within the agencies.Sensorimotor coordination mechanisms of metabolic adaptation expanded shapes. Some of these coordination mechanisms are linked to the perception with the environment through pulses, as temporal processing of signals.

  8. Fully decentralized control of a soft-bodied robot inspired by true slime mold.

    Science.gov (United States)

    Umedachi, Takuya; Takeda, Koichi; Nakagaki, Toshiyuki; Kobayashi, Ryo; Ishiguro, Akio

    2010-03-01

    Animals exhibit astoundingly adaptive and supple locomotion under real world constraints. In order to endow robots with similar capabilities, we must implement many degrees of freedom, equivalent to animals, into the robots' bodies. For taming many degrees of freedom, the concept of autonomous decentralized control plays a pivotal role. However a systematic way of designing such autonomous decentralized control system is still missing. Aiming at understanding the principles that underlie animals' locomotion, we have focused on a true slime mold, a primitive living organism, and extracted a design scheme for autonomous decentralized control system. In order to validate this design scheme, this article presents a soft-bodied amoeboid robot inspired by the true slime mold. Significant features of this robot are twofold: (1) the robot has a truly soft and deformable body stemming from real-time tunable springs and protoplasm, the former is used for an outer skin of the body and the latter is to satisfy the law of conservation of mass; and (2) fully decentralized control using coupled oscillators with completely local sensory feedback mechanism is realized by exploiting the long-distance physical interaction between the body parts stemming from the law of conservation of protoplasmic mass. Simulation results show that this robot exhibits highly supple and adaptive locomotion without relying on any hierarchical structure. The results obtained are expected to shed new light on design methodology for autonomous decentralized control system.

  9. A world review of fungi, yeasts, and slime molds in caves

    Directory of Open Access Journals (Sweden)

    McAlpine Donald F.

    2013-01-01

    Full Text Available We provide a review of fungi, yeasts, and slime molds that have been found in natural solution caves and mines worldwide. Such habitats provide frequent roost sites for bats, and in eastern North America the environmental conditions that support white-nose syndrome, a lethal fungal disease currently devastating bat populations. A list of 1029 species of fungi, slime moulds, and yeasts in 518 genera have been documented from caves and mines worldwide in 225 articles. Ascomycota dominate the cave environment. Most research has been conducted in temperate climates, especially in Europe. A mean of 17.9±24.4SD fungal species are reported per study. Questions remain about the origin and ecological roles of fungi in caves, and which, if any, are cave-specialists. In the northern hemisphere, caves are generally characterized by relatively stable, low temperatures and a lack of organic substrates. This environment favors communities of oligotrophic, psychrotolerant fungi. Data that may help explain how cave environmental features and faunas inf luence the introduction and transmission of cave fungi remains scant.

  10. Radiation effects on the species-specific cell sorting-out of the cellular slime molds

    International Nuclear Information System (INIS)

    Satow, Takashi

    1976-01-01

    The effects of gamma-rays irradiation on the development and the species-specific cell sorting-out of the cellular slime mold, Dictyostelium discoideum, were investigated. The interphase amoebae of the organism showed extremely resistant to 60 Co gamma-rays. The percentage of non-stained cells estimated by dye staining method was more than 90% at the dose of 270 kR. The amoebae irradiated at 270 kR performed the development similar in the most respects to that of the un-irradiated amoebae except that a little portion of the fruiting bodies were abnormal and that the appearance of aggregates and slugs delayed 3 hrs. The ability of the species-specific cell sorting-out was not affected by gamma-rays irradiation at 270 kR. (auth.)

  11. Diversity of plasmodial slime molds (myxomycetes in coastal, mountain, and community forests of Puerto Galera, Oriental Mindoro, the Philippines

    Directory of Open Access Journals (Sweden)

    Nikki Heherson A. Dagamac

    2015-12-01

    Full Text Available No profiling of diversity of myxomycetes has ever been conducted in one of the biodiversity hotspot areas in the Philippine archipelago, and this necessitates a swift survey of myxomycetes in Puerto Galera, Oriental Mindoro. An assessment of diversity of myxomycetes collected from seven collecting points of three different forest types in the study area showed a total of 926 records of myxomycetes. Of which, 42 morphospecies belonging to 16 genera are reported in this study. Species richness of myxomycetes was higher in collecting points that were found in inland lowland mountain forests, but the most taxonomically diverse species was found in coastal forests. Myxomycete species, namely, Arcyria cinerea, Diderma hemisphaericum, Physarum echinosporum, Lamproderma scintillans, and Stemonitis fusca, were found in all the collecting points. Manmade disturbances and forest structure may affect the occurrence of myxomycetes.

  12. Effect of sodium fluoride on the amount of polyribosomes, single ribosomes and ribosomal subunits in a cellular slime mold, Dictyostelium discoideum

    Energy Technology Data Exchange (ETDEWEB)

    Sameshima, M; Ito, K; Iwabuchi, M

    1972-01-01

    In the slime mold, Dictyostelium discoideum, when the rate of protein synthesis was decreased by NaF, free 80-S ribosomes accumulated at the expense of polyribosomes, while 60-S and 40-S ribosomal subunits remained almost constant. The same level of ribosomal subunits was also maintained in cells after incubation with cycloheximide or at the stationary phase of growth.

  13. The TOM Complex of Amoebozoans: the Cases of the Amoeba Acanthamoeba castellanii and the Slime Mold Dictyostelium discoideum.

    Science.gov (United States)

    Wojtkowska, Małgorzata; Buczek, Dorota; Stobienia, Olgierd; Karachitos, Andonis; Antoniewicz, Monika; Slocinska, Małgorzata; Makałowski, Wojciech; Kmita, Hanna

    2015-07-01

    Protein import into mitochondria requires a wide variety of proteins, forming complexes in both mitochondrial membranes. The TOM complex (translocase of the outer membrane) is responsible for decoding of targeting signals, translocation of imported proteins across or into the outer membrane, and their subsequent sorting. Thus the TOM complex is regarded as the main gate into mitochondria for imported proteins. Available data indicate that mitochondria of representative organisms from across the major phylogenetic lineages of eukaryotes differ in subunit organization of the TOM complex. The subunit organization of the TOM complex in the Amoebozoa is still elusive, so we decided to investigate its organization in the soil amoeba Acanthamoeba castellanii and the slime mold Dictyostelium discoideum. They represent two major subclades of the Amoebozoa: the Lobosa and Conosa, respectively. Our results confirm the presence of Tom70, Tom40 and Tom7 in the A. castellanii and D. discoideum TOM complex, while the presence of Tom22 and Tom20 is less supported. Interestingly, the Tom proteins display the highest similarity to Opisthokonta cognate proteins, with the exception of Tom40. Thus representatives of two major subclades of the Amoebozoa appear to be similar in organization of the TOM complex, despite differences in their lifestyle. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

  14. On the applicability of the decentralized control mechanism extracted from the true slime mold: a robotic case study with a serpentine robot

    International Nuclear Information System (INIS)

    Sato, Takahide; Kano, Takeshi; Ishiguro, Akio

    2011-01-01

    A systematic method for an autonomous decentralized control system is still lacking, despite its appealing concept. In order to alleviate this, we focused on the amoeboid locomotion of the true slime mold, and extracted a design scheme for the decentralized control mechanism that leads to adaptive behavior for the entire system, based on the so-called discrepancy function. In this paper, we intensively investigate the universality of this design scheme by applying it to a different type of locomotion based on a 'synthetic approach'. As a first step, we implement this design scheme to the control of a real physical two-dimensional serpentine robot that exhibits slithering locomotion. The experimental results show that the robot exhibits adaptive behavior and responds to the environmental changes; it is also robust against malfunctions of the body segments due to the local sensory feedback control that is based on the discrepancy function. We expect the results to shed new light on the methodology of autonomous decentralized control systems.

  15. Mold

    Science.gov (United States)

    ... has developed a device known as an acoustical generator that can create and disperse molds for rodent ... Sciences) . 2004. Damp Indoor Spaces and Health. Washington, DC: The National Academies Press. 3 WHO ( World Health ...

  16. Mold

    Centers for Disease Control (CDC) Podcasts

    2011-05-02

    This podcast answers a listener's question about the risks associated with mold after a natural disaster or severe weather.  Created: 5/2/2011 by National Center for Environmental Health (NCEH).   Date Released: 5/2/2011.

  17. Analysis of the volatiles in the headspace above the plasmodium and sporangia of the slime mould (Physarum polycephalum) by SPME-GCMS

    OpenAIRE

    Kateb, Huda al; Costello, Ben de Lacy

    2013-01-01

    Solid phase micro-extraction (SPME) coupled with Gas Chromatography Mass Spectrometry (GC-MS) was used to extract and analyse the volatiles in the headspace above the plasmodial and sporulating stages of the slime mould Physarum Polycephalum. In total 115 compounds were identified from across a broad range of chemical classes. Although more (87) volatile organic compounds (VOCs) were identified when using a higher incubation temperature of 75oC, a large number of compounds (79) were still ide...

  18. Asymptomatic plasmodial infection in Colombian pregnant women.

    Science.gov (United States)

    Carmona-Fonseca, Jaime; Agudelo, Olga M; Arango, Eliana M

    2017-08-01

    Information about asymptomatic plasmodial infection is scarce in the world, and the current antimalarial program goals (control, elimination, and eradication) demand this evidence to be well documented in different populations and malaria transmission settings. This study aimed to measure the prevalence of API in Colombian pregnant women at delivery. A retrospective prevalence survey was used. Women were recruited at hospital obstetric facility in each of the municipalities of Turbo, Necoclí in Antioquia department, and Puerto Libertador in Córdoba department. Malaria infection was tested by thick blood smear (TBS) and real-time quantitative PCR (qPCR). Ninety-six pregnant women at delivery were studied: 95% were asymptomatic (91/96), 45% had asymptomatic plasmodial infection (API) by qPCR (41/91), and only 8% (7/91) had API by microscopy. The prevalence of submicroscopic infections (TBS negative and qPCR positive) was very high, 37% (34/91) in asymptomatic women and 41% (39/96) in total women studied (91 asymptomatic and 5 symptomatic). The prevalence of API in Colombian pregnant women is much higher than which is expected for a country that does not have the level of malaria transmission as Sub-Saharan African countries. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Stanley Corrsin Award Talk: Fluid Mechanics of Fungi and Slime

    Science.gov (United States)

    Brenner, Michael

    2013-11-01

    There are interesting fluid mechanics problems everywhere, even in the most lowly and hidden corners of forest floors. Here I discuss some questions we have been working on in recent years involving fungi and slime. A critical issue for the ecology of fungi and slime is nutrient availability: nutrient sources are highly heterogeneous, and strategies are necessary to find food when it runs out. In the fungal phylum Ascomycota, spore dispersal is the primary mechanism for finding new food sources. The defining feature of this phylum is the ascus, a fluid filled sac from which spores are ejected, through a build up in osmotic pressure. We outline the (largely fluid mechanical) design constraints on this ejection strategy, and demonstrate how it provides strong constraints for the diverse morphologies of spores and asci found in nature. The core of the argument revisits a classical problem in elastohydrodynamic lubrication from a different perspective. A completely different strategy for finding new nutrient is found by slime molds and fungi that stretch out - as a single organism- over enormous areas (up to hectares) over forest floors. As a model problem we study the slime mold Physarum polycephalum, which forages with a large network of connected tubes on the forest floors. Localized regions in the network find nutrient sources and then pump the nutrients throughout the entire organism. We discuss fluid mechanical mechanisms for coordinating this transport, which generalize peristalsis to pumping in a heterogeneous network. We give a preliminary discussion to how physarum can detect a nutrient source and pump the nutrient throughout the organism.

  20. Hydrogel Beads: The New Slime Lab?

    Science.gov (United States)

    Brockway, Debra; Libera, Matthew; Welner, Heidi

    2011-01-01

    Creating slime fascinates students. Unfortunately, though intrigue is at its peak, the educational aspect of this activity is often minimal. This article describes a chemistry lab that closely relates to the slime lab and allows high school students to explore the concepts of chemical bonding, properties, and replacement reactions. It involves the…

  1. Analysis of Rheb in the cellular slime mold Dictyostelium discoideum

    Indian Academy of Sciences (India)

    2014-01-27

    Jan 27, 2014 ... lyse the caspase-independent cell death mechanism. It is a ..... we observed exclusive expression in the prespore region. (figure 5A). There were ..... disc formation in Dictyostelium discoideum is an early event in culmination.

  2. Analysis of Rheb in the cellular slime mold Dictyostelium ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Treatment of the overexpressing Rheb cells with rapamycin confirms its involvement in the TOR signalling pathway. ... The domain part of the email address of all email addresses used by the office of Indian Academy of Sciences, including those of the staff, the journals, various programmes, and Current ...

  3. The coordination between mechanical and chemical subsystems initiates locomotion of Physarum plasmodial fragments

    Science.gov (United States)

    Zhang, Shun; Guy, Robert; Del Alamo, Juan Carlos

    2017-11-01

    Physarum polycephalum is a multinucleated slime mold whose endoplasm flows periodically driven by the contraction of its ectoplasm, a dense shell of F-actin cross-linked by myosin molecular motors and attached to the cell membrane. We find that physarum fragments smaller than 100 microns remain round and stay in place. However, larger fragments break symmetry leading to sustained forward locomotion, in process that is reminiscent of an interfacial instability that seems to settle around two different limit cycles (traveling waves and standing waves). We use both theory and experiments to study how coordination emerges between the different mechanical and chemical subsystems of the fragment to initiate locomotion. The role of many involved factors, such as fragment size, substratum adhesiveness, rheological properties, actin polymerization and traction stresses are investigated, and we find they agree well with our predictive model.

  4. Waste management implications of concentrating slimes

    International Nuclear Information System (INIS)

    1988-02-01

    The anticipated increase in demand for sand-size tailings from the uranium industry suggests that the fine-grained or 'slime' fraction will require special attention for disposal. The Atomic Energy Control Board (AECB) required information on the behaviour and environmental significance of the fine-grained tailings fraction in disposal facilities. Beak Consultants and Golder Associates were contracted to review the significant characteristics of slimes disposal and prepare a report on the physical and chemical characteristics of fine-grained tailings (Phase 1). This report (Phase 2) presents a summary of disposal and management practices for slimes and outlines potential concerns related to these practices. The report also presents an approach to disposal planning and the implications of available and potential management techniques. Experience with the disposal of uranium slimes is scarce and, therefore, relevant information was borrowed from the other mining sectors to predict the consequences of various disposal scenarios

  5. Hagfish slime exudate stabilization and its effect on slime formation and functionality.

    Science.gov (United States)

    Böni, L J; Zurflüh, R; Widmer, M; Fischer, P; Windhab, E J; Rühs, P A; Kuster, S

    2017-07-15

    Hagfish produce vast amounts of slime when under attack. The slime is the most dilute hydrogel known to date, and is a highly interesting material for biomaterial research. It forms from a glandular secrete, called exudate, which deploys upon contact with seawater. To study slime formation ex vivo and to characterize its material properties, stabilization of the sensitive slime exudate is crucial. In this study, we compared the two main stabilization methods, dispersion in high osmolarity citrate/PIPES (CP) buffer and immersion in oil, and tested the influence of time, temperature and pH on the stability of the exudate and functionality of the slime. Using water retention measurements to assess slime functionality, we found that CP buffer and oil preserved the exudate within the first 5 hours without loss of functionality. For longer storage times, slime functionality decreased for both stabilization methods, for which the breakdown mechanisms differed. Stabilization in oil likely favored temperature-sensitive osmotic-driven swelling and rupture of the mucin vesicles, causing the exudate to gel and clump. Extended storage in CP buffer resulted in an inhibited unraveling of skeins. We suggest that a water soluble protein glue, which mediates skein unraveling in functional skeins, denatures and gradually becomes insoluble during storage in CP buffer. The breakdown was accentuated when the pH of the CP buffer was raised from pH 6.7 to pH 8.5, probably caused by increased denaturation of the protein glue or by inferior vesicle stabilization. However, when fresh exudate was mixed into seawater or phosphate buffer at pH 6-9, slime functionality was not affected, showing pH insensitivity of the slime formation around a neutral pH. These insights on hagfish exudate stabilization mechanisms will support hagfish slime research at a fundamental level, and contribute to resolve the complex mechanisms of skein unraveling and slime formation. © 2017. Published by The Company

  6. Electrometallurgy of copper refinery anode slimes

    Science.gov (United States)

    Scott, J. D.

    1990-08-01

    High-selenium copper refinery anode slimes form two separate and dynamically evolving series of compounds with increasing electrolysis time. In one, silver is progressively added to non-stoichiometric copper selenides, both those originally present in the anode and those formed subsequently in the slime layer, and in the other, silver-poor copper selenides undergo a dis-continuous crystallographic sequence of anodic-oxidative transformations. The silver-to-selenium molar ratio in the as-cast anode and the current density of electrorefining can be used to construct predominance diagrams for both series and, thus, to predict the final bulk “mineralogy” of the slimes. Although totally incorrect in detail, these bulk data are sufficiently accurate to provide explanations for several processing problems which have been experienced by Kidd Creek Division, Falconbridge Ltd., in its commercial tankhouse. They form the basis for a computer model which predicts final cathode quality from chemical analyses of smelter feed.

  7. Allergies, asthma, and molds

    Science.gov (United States)

    Reactive airway - mold; Bronchial asthma - mold; Triggers - mold; Allergic rhinitis - pollen ... Things that make allergies or asthma worse are called triggers. Mold is a common trigger. When your asthma or allergies become worse due to mold, you are ...

  8. Waste management implications of concentrating slimes - characteristics and potential problems

    International Nuclear Information System (INIS)

    1986-05-01

    This report describes the geotechnical, geochemical and environmental characteristics of fine-grained uranium tailings (slimes) which may influence both short- and long-term management of slime-enriched uranium tailings impoundments. Properties of slimes are compared and contrasted with those of sand tailings using field and laboratory data primarily from naturally segregated tailings in the Elliot Lake area, Ontario and Northern Saskatchewan uranium-bearing regions of Canada. Key management considerations are included

  9. Molds in the Environment

    Science.gov (United States)

    ... on Facebook Tweet Share Compartir Molds in the Environment What are molds? What are some of the ... molds found? Molds are found in virtually every environment and can be detected, both indoors and outdoors, ...

  10. 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...

  11. Anti-plasmodial and antioxidant activities of methanol extract of the ...

    African Journals Online (AJOL)

    This study was aimed at investigating the anti-plasmodial and antioxidant activities of the extract of the leaf of Lophira lanceolata, a traditional medicine recipe. The methanol extract (ME) obtained by 72 h cold maceration was evaluated for acute toxicity test (LD50) and phytochemical constituents. The suppressive and ...

  12. Isotope investigation of anodic slime movements in copper electrorefining baths

    International Nuclear Information System (INIS)

    Urbanski, T.; Kohman, L.; Strzelecki, M.; Chojecki, M.; Kaczynska, R.; Wieclaw, B.

    1975-01-01

    A method was developed and introduced for monitoring the movement of silver-containing anodic slimes in copper electrorefining baths. Radioactive 111 Ag was used as tracer and copper plates labelled with the tracer were inserted into the anodes. During electrorefining the slime produced was continuously marked by the tracer. The activity of 111 Ag was measured at various points inside the bath by sampling and continuously registered with the aid of integrators. It was found that more than 99 percent of the slime slipped to the bottom of the bath close to the anode surface and did not migrate even at highest electrolyte flow rates. Small quantities of suspended slime contained an insignificant concentration of silver and should not be a source of cathode contamination. (author)

  13. 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

  14. The Slime Production by Yeasts Isolated from Subclinical Mastitic Cows

    Directory of Open Access Journals (Sweden)

    Süheyla Türkyılmaz

    2010-01-01

    Full Text Available The aim of this study was to isolate yeasts from subclinical mastitic cows and to investigate the slime production by the isolated yeasts. The material used in this study included 339 milk samples from 152 dairy cattle with subclinical mastitis. Milk was plated onto blood agar, MacConkey agar and Sabouraud dextrose agar. Forty-one samples (12.1% of total milk samples were found positive for the yeast by API 20 C AUX identification system. The isolated yeasts were classified into four genera of Candida, Trichosporon, Cryptococcus and Saccharomyces. The Candida species were following: C. krusei, C. kefyr, C. guilliermondii, C. famata, C. rugosa and C. utulis. Other yeasts were identified as Trichosporon mucoides, T. asahii, Cryptococcus laurentii, C.  neoformans and Saccharomyces cerevisiae. Slime production was tested on Congo red brain heart infusion agar and evaluated according to Congo red phenomenon. Fifteen (36.6% strains were slime factor positive: seven were C. krusei, four C. kefyr, one C. guilliermondii, one C. famata, one T. asahii, and one C. laurentii. The results of the present study indicate that yeast mastitis is significant for causing economic losses and slime production is mostly found in non-albicans Candida species. Therefore, non-albicans Candida species should be examined for slime production.

  15. Floods and Mold Growth

    Science.gov (United States)

    Mold growth may be a problem after flooding. Excess moisture in the home is cause for concern about indoor air quality primarily because it provides breeding conditions for pests, molds and other microorganisms.

  16. Interactive Mold House Tour

    Science.gov (United States)

    Get a quick glimpse of some of the most important ways to protect your home from mold by this interactive tour of the Mold House. Room-by-room, you'll learn about common mold issues and how to address them.

  17. Recovery of Silver and Gold from Copper Anode Slimes

    Science.gov (United States)

    Chen, Ailiang; Peng, Zhiwei; Hwang, Jiann-Yang; Ma, Yutian; Liu, Xuheng; Chen, Xingyu

    2015-02-01

    Copper anode slimes, produced from copper electrolytic refining, are important industrial by-products containing several valuable metals, particularly silver and gold. This article provides a comprehensive overview of the development of the extraction processes for recovering silver and gold from conventional copper anode slimes. Existing processes, namely pyrometallurgical processes, hydrometallurgical processes, and hybrid processes involving the combination of pyrometallurgical and hydrometallurgical technologies, are discussed based in part on a review of the form and characteristics of silver and gold in copper anode slimes. The recovery of silver and gold in pyrometallurgical processes is influenced in part by the slag and matte/metal chemistry and related characteristics, whereas the extraction of these metals in hydrometallurgical processes depends on the leaching reagents used to break the structure of the silver- and gold-bearing phases, such as selenides. By taking advantage of both pyrometallurgical and hydrometallurgical techniques, high extraction yields of silver and gold can be obtained using such combined approaches that appear promising for efficient extraction of silver and gold from copper anode slimes.

  18. Biosorption of mercury by capsulated and slime layerforming Gram ...

    African Journals Online (AJOL)

    The biosorption of mercury by two locally isolated Gram-ve bacilli: Klebsiella pneumoniae ssp. pneumonia (capsulated) and slime layer forming Pseudomonas aeruginosa, was characterized. Mercury adsorption was found to be influenced by the pH value of the biosorption solution, initial metal concentration, amount of the ...

  19. Investigation of Association between Slime Production by Candida ...

    African Journals Online (AJOL)

    Purpose: To determine the susceptibilities of fluconazole and voriconazole based on slime production by Candida spp. Methods: Candida strains (115) isolated in the period between January 2011 and January 2012 were included in this study. ... Yıldırım Beyazıt Training Hospital, were included in this study. Candida ...

  20. EDTA treatment alters protein glycosylation in the cellular slime mold Dictyostelium discoideum

    International Nuclear Information System (INIS)

    West, C.M.; Brownstein, S.A.

    1988-01-01

    The authors have found that treatment of cells with EDTA resulted in the accumulation of lower molecular weight forms of two cell-type-specific glycoproteins. These new glycoproteins lacked a developmentally regulated glycoantigen defined by monoclonal antibody 54.2. Since EDTA dissociated the cells, the possible involvement of cell separation was tested by immobilizing cells in soft agarose. Glycoantigen expression on these proteins was found to be dependent on cAMP and high oxygen tension but not on cell contact, and was reversibly sensitive to EDTA regardless of the state of cell association. The EDTA effect was mimicked by other soluble, but not particulate, membrane impermeable chelators, could be completed by Zn 2+ better than Mg 2+ , and appeared to involve an intracellular mechanism. Studies with [ 14 C]EDTA showed that EDTA equilibrated with a cellular compartment in a temperature-dependent, Zn 2+ -insensitive fashion with half-time kinetics of loading and unloading of 30-40 min. The data suggest that this step in glycosylation, which was found to be delayed 1 or more hours subsequent to protein synthesis, involves an intracellular, transition metal-ion-dependent process which can be modulated by chelators entering the cell through the endocytic pathway

  1. Behaviour of polonium-210 during anode slimes processing

    International Nuclear Information System (INIS)

    Brown, S. A.

    1998-01-01

    Refinery slimes produced during the electrorefining of copper anodes often contain recoverable quantities of gold, silver and the platinum group metals, platinum and palladium. The treatment process selected to recover precious metals from the slimes depends on the concentration of other impurities. Polonium-210 will be present in the refinery slimes when uranium-bearing minerals (e.g. uraninite) are associated with the copper mineralogy. The production of pure precious metals from copper anode slimes containing polonium-210 involves a variety of steps including impurity removal, smelting to produce a dore metal and then refining. Gold and silver are recovered by electrorefining processes. Platinum group metals accumulate in the gold electrolyte and are recovered by precipitation. To ensure that specifications are met in the final products, it is necessary to identify and closely monitor where the impurities, including polonium-210, are partitioning during processing. Although measurement of polonium-210 activity using alpha spectrometry identifies relative amounts of the radionuclide in the various streams, it does not give any indication of the form it may be in. By studying the chemistry and deportment of its neighbours in the periodic table (Pb,Bi,Se and Te) it may be possible to make some conclusions regarding polonium-210 behaviour. Examination of the solid phases produced during anode slimes treatment were carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Elemental analyses of solid and liquor streams were carried out using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES). This paper attempts to develop a relationship between the behaviour of polonium-210 and other impurities during precious metals recovery based on the results of these studies

  2. Behaviour of polonium-210 during anode slimes processing

    International Nuclear Information System (INIS)

    Brown, S.A.

    1998-01-01

    Refinery slimes produced during the electrorefining of copper anodes often contain recoverable quantities of gold, silver and the platinum group metals, platinum and palladium. The treatment process selected to recover precious metals from the slimes depends on the concentration of other impurities. Polonium 210 will be present in the refinery slimes when uranium-bearing minerals (eg. uraninite) are associated with the copper mineralogy. The production of pure precious metals from copper anode slimes containing polonium-210 involves a variety of steps including impurity removal smelting to produce a dore metal and then refining. Gold and silver are recovered by electrorefining processes. Platinum group metals accumulate in the gold electrolyte and are recovered by precipitation To ensure that specifications are met in the final products, it is necessary to identify and closely monitor where the impurities, including polonium-210, are partitioning during processing. Although measurement of polonium-210 activity using alpha spectrometry identifies relative amounts of the radionuclide in the various streams, it does not give any indication of the form it may be in. By studying the chemistry and deportment of its neighbours in the periodic table (Pb, Bi, Se and Te) it may be possible to make some conclusions regarding polonium-210 behaviour. Examination of the solid phases produced during anode slimes treatment were carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Elemental analyses of solid and liquor streams were carried out using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES). This paper attempts to develop a relationship between the behaviour of polonium-210 and other impurities during precious metals recovery based on the results of these studies. (author). 5 refs., 4 tabs

  3. Modern immunological approaches to assess malaria transmission and immunity and to diagnose plasmodial infection

    Directory of Open Access Journals (Sweden)

    C. T. Daniel-Ribeiro

    1992-01-01

    Full Text Available The present paper reviews our recent data concerning the use of immunological methods employing monoclonal antibodies and synthetic peptides to study malaria transmission and immunity and to diagnose plasmodial infection. As concerns malaria transmission, we studied the main vectors of human malaria and the plasmodial species transmitted in endemic areas of Rondônia state, Brazil. The natural infection on anopheline was evaluated by immunoradiometric assay (IRMA using monoclonal antibodies to an immunodominant sporozoite surface antigen (CS protein demonstrated to be species specific. Our results showed that among six species of Anopheles found infected, An. darlingi was the main vector transmitting Plasmodium falciparum and P. vivax malaria in the immediate vicinity of houses. In order to assess the level of anti-CS antibodies we studied, by IRMA using the synthetic peptide corresponding to the repetitive epitope of the sporozoite CS protein, sera of individuals living in the same areas where the entomological survey has been performed. In this assay the prevalence of anti-CS antibodies was very low and did not reflect the malaria transmission rate in the studied areas. In relation to malaria diagnosis, a monoclonal antibody specific to an epitope of a 50 kDa exoantigen, the major component of supernatant collected at the time of schizont rupture, was used as a probe for the detection of P. falciparum antigens. This assay seemed to be more sensitive than parasitological examination for malaria diagnosis since it was able to detect plasmodial antigens in both symptomatic and asymtomatic individuals with negative thick blood smear at different intervals after a last parasitologically confirmed confirmed attack of malaria.

  4. The effects of four different drugs administered through catheters on slime production in coagulase negative Staphylococci

    Directory of Open Access Journals (Sweden)

    J. Sedef Göçmen

    2012-12-01

    Full Text Available Objectives: Higher rate of slime production has been found in pathogen bacteria strains. Accordingly, the factors thatcontribute to higher slime production rate increase the infection risk, while the factors that reduce the slime productionrate will reduce the infection risk. The effect of some drugs that are administered through catheters in intensive careunits on slime production with coagulase negative Staphylococci was investigated.Materials and methods: In this study, the effect of four different preparations containing Glyceryl trinitrate (Perlinganit®, Dexmedetomidine (Precedex®, Esmolol (Brevibloc®, and Propofol (Propofol® on slime production of 24Staphylococcus epidermidis strains isolated from blood cultures of patients, and reference strain were investigated. Slimeproduction was determined using ‘the quantitative microdilution plaque test’ described by Christensen.Results: Under controlled medium, eight strains formed slimes, and in the media containing esmolol, glyceryl trinitrate,dexmedetomidine, and propofol slimes were positive for five, 21, 15, and 18 strains, respectively. The rate of slime productionin glyceryl trinitrate, dexmedetomidine, and propofol containing media were higher than that of the controls.Conclusions: In the light of the results of this study, it is concluded that the drugs and/or additives increase the rate ofslime production. The effects of the preparations administered through catheters on slime production should be investigated,and these effects should be kept in mind during their use. J Microbiol Infect Dis 2012; 2(4: 150-154Key words: Slime Production, Coagulase Negative Staphyloccoci, Parenteral drugs

  5. Hagfish slime and mucin flow properties and their implications for defense

    Science.gov (United States)

    Böni, Lukas; Fischer, Peter; Böcker, Lukas; Kuster, Simon; Rühs, Patrick A.

    2016-07-01

    When hagfish (Myxinidae) are attacked by predators, they form a dilute, elastic, and cohesive defensive slime made of mucins and protein threads. In this study we propose a link between flow behavior and defense mechanism of hagfish slime. Oscillatory rheological measurements reveal that hagfish slime forms viscoelastic networks at low concentrations. Mucins alone did not contribute viscoelasticity, however in shear flow, viscosity was observed. The unidirectional flow, experienced by hagfish slime during suction feeding by predators, was mimicked with extensional rheology. Elongational stresses were found to increase mucin viscosity. The resulting higher resistance to flow could support clogging of the attacker’s gills. Shear flow in contrast decreases the slime viscosity by mucin aggregation and leads to a collapse of the slime network. Hagfish may benefit from this collapse when trapped in their own slime and facing suffocation by tying a sliding knot with their body to shear off the slime. This removal could be facilitated by the apparent shear thinning behavior of the slime. Therefore hagfish slime, thickening in elongation and thinning in shear, presents a sophisticated natural high water content gel with flow properties that may be beneficial for both, defense and escape.

  6. Heterologous expression of plasmodial proteins for structural studies and functional annotation

    CSIR Research Space (South Africa)

    Birkholtz, LM

    2008-01-01

    Full Text Available Malaria Journal Open AcceReview Heterologous expression of plasmodial proteins for structural studies and functional annotation Lyn-Marie Birkholtz1, Gregory Blatch2, Theresa L Coetzer3, Heinrich C Hoppe1,4, Esmaré Human1, Elizabeth J Morris1,5, Zoleka Ngcete..., Kwadlangezwa, South Africa Email: Lyn-Marie Birkholtz - lbirkholtz@up.ac.za; Gregory Blatch - G.Blatch@ru.ac.za; Theresa L Coetzer - theresa.coetzer@nhls.ac.za; Heinrich C Hoppe - hhoppe@csir.co.za; Esmaré Human - esmare.human@up.ac.za; Elizabeth J Morris...

  7. An easy mold

    International Nuclear Information System (INIS)

    Kim, Nam Hun; Choe, Jong Sun

    1988-04-01

    This book deals with an easy mold, which introduces what is a mold kinds and classification of mold. It gives descriptions of easy theories such as basic knowledge on shearing work, clearance, power for punching and shear angle, basic knowledge for bending such as transform by bending, the minimal bending radius, spring back, the length of material, flexural strength for bending, fundamental knowledge for drawing work with transform of drawing and limitation of drawing.

  8. Anti-plasmodial activity of some Zulu medicinal plants and of some triterpenes isolated from them.

    Science.gov (United States)

    Simelane, Mthokozisi B C; Shonhai, Addmore; Shode, Francis O; Smith, Peter; Singh, Mogie; Opoku, Andy R

    2013-10-08

    Mimusops caffra E. Mey. ex A.DC and Mimusops obtusifolia Lam (both members of the Sapotaceae family), and Hypoxis colchicifolia Bak (family Hypoxidaceae) are used by traditional healers in Zululand to manage malaria. Anti-plasmodial investigation of the crude extracts and some triterpenes isolated from the plants showed activity against a chloroquine sensitive (CQS) strain of Plasmodium falciparum (D10). Among the crude extracts the leaves of M. caffra exhibited the highest activity, with an IC₅₀ of 2.14 μg/mL. The pentacyclic tritepenoid ursolic acid (1), isolated from the leaves of M. caffra was the most active compound (IC₅₀ 6.8 μg/mL) as compared to taraxerol (2) and sawamilletin (3) isolated from the stem bark of M. obtusifolia (IC₅₀ > 100). Chemical modification of the ursolic acid (1) to 3β-acetylursolic acid (4) greatly enhanced its anti-plasmodial activity. Compound 4 reduced parasitaemia against Plasmodium berghei by 94.01% in in vivo studies in mice. The cytotoxicity of 3β-acetylursolic acid (IC₅₀) to two human cell lines (HEK293 and HepG2) was 366.00 μg/mL and 566.09 μg/mL, respectively. The results validate the use of these plants in folk medicine.

  9. Processing of copper anodic-slimes for extraction of valuable metals.

    Science.gov (United States)

    Amer, A M

    2003-01-01

    This work focuses on processing of anodic slimes obtained from an Egyptian copper electrorefining plant. The anodic slimes are characterized by high concentrations of copper, lead, tin and silver. The proposed hydrometallurgical process consists of two leaching stages for the extraction of copper (H(2)SO(4)-O(2)) and silver (thiourea-Fe3+), and pyrometallurgical treatment of the remaining slimes for production of Pb-Sn soldering alloy. Factors affecting both the leaching and smelting stages were studied.

  10. Phenolic Molding Compounds

    Science.gov (United States)

    Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

    Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

  11. Mold After a Disaster

    Science.gov (United States)

    ... should clean up the mold and fix any water problem, such as leaks in roofs, walls, or plumbing. Controlling moisture in your home is the most critical factor for preventing mold growth. To ... use commercial products, soap and water, or a bleach solution of no more than ...

  12. Technique of complex slime water treatment of coal-mining branch

    OpenAIRE

    Solodov, G. А.; Zhbyr, Е. V.; Papin, А. V.; Nevedrov, А. V.

    2007-01-01

    The possibility of complex slime water treatment at coal-mining and coal-treating plants producing marketable products: power-generating concentrate, coal-water fuel, magnetic fraction, industrial water is shown. A basic process flowsheet of slime water treatment presenting a united technological complex is suggested.

  13. Demonstration of the Coagulation and Diffusion of Homemade Slime Prepared under Acidic Conditions without Borate

    Science.gov (United States)

    Isokawa, Naho; Fueda, Kazuki; Miyagawa, Korin; Kanno, Kenichi

    2015-01-01

    Poly(vinyl alcohol) (PVA) precipitates in many kinds of aqueous salt solutions. While sodium sulfate, a coagulant for PVA fiber, precipitates PVA to yield a white rigid gel, coagulation of PVA with aluminum sulfate, a coagulant for water treatment, yields a slime-like viscoelastic fluid. One type of homemade slime is prepared under basic…

  14. Structural Characterisation and Enzymatic Degradation of Exopolysaccharides involved in Paper Mill Slime deposition

    NARCIS (Netherlands)

    Verhoef, R.P.

    2005-01-01

    Bacteria that adhere to the surface of a paper machine form a biofilm that entraps the fibres and additives used as raw material to form a slime deposit. The formation of these slime deposits can result in serious problems with respect to the papermaking process itself and the end product.

  15. Anti-plasmodial action of de novo-designed, cationic, lysine-branched, amphipathic, helical peptides

    Directory of Open Access Journals (Sweden)

    Kaushik Naveen K

    2012-08-01

    Full Text Available Abstract Background A lack of vaccine and rampant drug resistance demands new anti-malarials. Methods In vitro blood stage anti-plasmodial properties of several de novo-designed, chemically synthesized, cationic, amphipathic, helical, antibiotic peptides were examined against Plasmodium falciparum using SYBR Green assay. Mechanistic details of anti-plasmodial action were examined by optical/fluorescence microscopy and FACS analysis. Results Unlike the monomeric decapeptides {(Ac-GXRKXHKXWA-NH2 (X = F,ΔF (Fm, ΔFm IC50 >100 μM}, the lysine-branched,dimeric versions showed far greater potency {IC50 (μM Fd 1.5 , ΔFd 1.39}. The more helical and proteolytically stable ΔFd was studied for mechanistic details. ΔFq, a K-K2 dendrimer of ΔFm and (ΔFm2 a linear dimer of ΔFm showed IC50 (μM of 0.25 and 2.4 respectively. The healthy/infected red cell selectivity indices were >35 (ΔFd, >20 (ΔFm2 and 10 (ΔFq. FITC-ΔFd showed rapid and selective accumulation in parasitized red cells. Overlaying DAPI and FITC florescence suggested that ΔFd binds DNA. Trophozoites and schizonts incubated with ΔFd (2.5 μM egressed anomalously and Band-3 immunostaining revealed them not to be associated with RBC membrane. Prematurely egressed merozoites from peptide-treated cultures were found to be invasion incompetent. Conclusion Good selectivity (>35, good resistance index (1.1 and low cytotoxicity indicate the promise of ΔFd against malaria.

  16. Determination of Calorific Ability of Fuel Briquettes on the Basis of Oil and Oil Slimes

    Science.gov (United States)

    Fedyaeva, O. A.; Poshelyuzhnaya, E. G.; Rakhmatulina, E. M.; Zakharov, V. A.; Fisenko, T. E.

    2018-01-01

    Utilization and neutralization of oil slimes is one of important environmental problems of the oil-extracting, oil-processing and petrochemical industry. The easiest and economic way of utilization of oil slimes is their use as a part of the bricketed boiler fuel. In this work the highest calorific ability of crude oil, the oil slimes and fuel briquettes made on their basis is defined. A research problem was carrying out the technical analysis of oil fuels on the content in them analytical moisture, the cindery rest and volatiles. It is established that in comparison with oil slimes crude oil possesses bigger highest calorific ability, has smaller humidity and an ash-content. The highest calorific abilities of the boiler briquettes made of samples of crude oil, oil slimes and peat made 14 - 26 MJ/kg.

  17. Mold: Cleanup and Remediation

    Science.gov (United States)

    ... National Center for Environmental Health (NCEH) Cleanup and Remediation Recommend on Facebook Tweet Share Compartir On This ... CDC and EPA on mold cleanup, removal and remediation. Cleanup information for you and your family Homeowner’s ...

  18. Transferability of glass lens molding

    Science.gov (United States)

    Katsuki, Masahide

    2006-02-01

    Sphere lenses have been used for long time. But it is well known that sphere lenses theoretically have spherical aberration, coma and so on. And, aspheric lenses attract attention recently. Plastic lenses are molded easily with injection machines, and are relatively low cost. They are suitable for mass production. On the other hand, glass lenses have several excellent features such as high refractive index, heat resistance and so on. Many aspheric glass lenses came to be used for the latest digital camera and mobile phone camera module. It is very difficult to produce aspheric glass lenses by conventional process of curve generating and polishing. For the solution of this problem, Glass Molding Machine was developed and is spreading through the market. High precision mold is necessary to mold glass lenses with Glass Molding Machine. The mold core is ground or turned by high precision NC aspheric generator. To obtain higher transferability of the mold core, the function of the molding machine and the conditions of molding are very important. But because of high molding temperature, there are factors of thermal expansion and contraction of the mold and glass material. And it is hard to avoid the factors. In this session, I introduce following items. [1] Technology of glass molding and the machine is introduced. [2] The transferability of glass molding is analyzed with some data of glass lenses molded. [3] Compensation of molding shape error is discussed with examples.

  19. 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).

  20. Dynamic of taking out molding parts at injection molding

    Directory of Open Access Journals (Sweden)

    E. Ragan

    2012-10-01

    Full Text Available Most plastic parts used in automobile production are manufactured by injection molding. Their quality depends also on taking out molding and on the manipulators for it. Task of this contribution is to theoretically describe a transport of molding at taking out after injection molding in relation on its regulation. The following quantities are derived at it: the transition characteristic of the taking out system, the blocking diagram of taking out molding regulation, the amplitude and phase characteristic and the transition characteristic of action quantity at taking out molding regulation.

  1. Recovery Of Valuable Metals In Tin-Based Anodic Slimes By Carbothermic Reaction

    OpenAIRE

    Han Chulwoong; Kim Young-Min; Son Seong Ho; Choi Hanshin; Kim Tae Bum; Kim Yong Hwan

    2015-01-01

    This study investigated the recovery of anodic slimes by carbothermic reaction in the temperature range of 973~1,273K and amount of carbon as a function of time. Tin anodic slime samples were collected from the bottom of the electrolytic cells during the electro-refining of tin. The anodic slimes are consisted of high concentrated tin, silver, copper and lead oxides. The kinetics of reduction were determined by means of the weight-loss measurement technique. In order to understand in detail o...

  2. You say "lean finely textured beef," I say "pink slime".

    Science.gov (United States)

    Reid, Rita-Marie Cain

    2014-01-01

    In 2012, American Broadcasting Companies, Inc. (ABC) broadcast a segment on its evening news show regarding the manufacture of "lean finely textured beef" by Beef Products, Inc. (BPI). The broadcast, as well as follow-up reports and social media communications, repeatedly referred to the product as "pink slime," a term originated by a United States Department of Agriculture (USDA) employee for the processed meat. The market backlash against the product was immediate and intense. Ultimately, BPI closed three processing plants, cut hundreds of jobs, and filed for bankruptcy. BPI sued ABC and others for food libel, defamation, and tortious interference. This research analyzes those claims and defenses and discusses the future of such cases.

  3. 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

  4. Recovery Of Valuable Metals In Tin-Based Anodic Slimes By Carbothermic Reaction

    Directory of Open Access Journals (Sweden)

    Han Chulwoong

    2015-06-01

    Full Text Available This study investigated the recovery of anodic slimes by carbothermic reaction in the temperature range of 973~1,273K and amount of carbon as a function of time. Tin anodic slime samples were collected from the bottom of the electrolytic cells during the electro-refining of tin. The anodic slimes are consisted of high concentrated tin, silver, copper and lead oxides. The kinetics of reduction were determined by means of the weight-loss measurement technique. In order to understand in detail of carbothermic reaction, thermodynamic calculation was carried out and compared with experiments. From thermodynamic calculation and experiment, it was confirmed that Sn-based anodic slime could be reduced by controlling temperature and amount of carbon. However, any tendency between the reduction temperature and carbon content for the reduction reaction was not observed.

  5. Study of effect of slime processed by ultrasonic on flotation reagent

    Energy Technology Data Exchange (ETDEWEB)

    Kang, W.; Wang, H.; Hu, J. [Heilongjiang Institute of Science and Technology, Harbin (China)

    2006-12-15

    The changes of wetting heat, oil film thickness, contact angle and absorptive capacity of slime and kerosene before and after ultrasonic treatment were studied by Setaram calorimeter, DCAT21 gauge and a light meter. Batch flotation tests were made. The results show that: the wetting heat from slime and kerosene increases after ultrasonic treatment by 45.85%; the average oil film thickness is reduced by 38.84%; the contact angle of slime and kerosene decreases by 33.56{sup o}; and the absorptive capacity of slime in kerosene decreases by 30.40%. The consumption of flotation reagent after ultrasonic treatment was reduced by 75% while the yield of clean coal was the same. The study shows that ultrasonic treatment decreases the consumption of reagent and increases the efficiency and selectivity of flotation. 8 refs., 3 figs., 4 tabs.

  6. Synergistic Malaria Parasite Killing by Two Types of Plasmodial Surface Anion Channel Inhibitors.

    Directory of Open Access Journals (Sweden)

    Margaret Pain

    Full Text Available Malaria parasites increase their host erythrocyte's permeability to a broad range of ions and organic solutes. The plasmodial surface anion channel (PSAC mediates this uptake and is an established drug target. Development of therapies targeting this channel is limited by several problems including interactions between known inhibitors and permeating solutes that lead to incomplete channel block. Here, we designed and executed a high-throughput screen to identify a novel class of PSAC inhibitors that overcome this solute-inhibitor interaction. These new inhibitors differ from existing blockers and have distinct effects on channel-mediated transport, supporting a model of two separate routes for solute permeation though PSAC. Combinations of inhibitors specific for the two routes had strong synergistic action against in vitro parasite propagation, whereas combinations acting on a single route produced only additive effects. The magnitude of synergism depended on external nutrient concentrations, consistent with an essential role of the channel in parasite nutrient acquisition. The identified inhibitors will enable a better understanding of the channel's structure-function and may be starting points for novel combination therapies that produce synergistic parasite killing.

  7. High Guanidinium Permeability Reveals Dehydration-Dependent Ion Selectivity in the Plasmodial Surface Anion Channel

    Directory of Open Access Journals (Sweden)

    Abdullah A. B. Bokhari

    2014-01-01

    Full Text Available Malaria parasites grow within vertebrate erythrocytes and increase host cell permeability to access nutrients from plasma. This increase is mediated by the plasmodial surface anion channel (PSAC, an unusual ion channel linked to the conserved clag gene family. Although PSAC recognizes and transports a broad range of uncharged and charged solutes, it must efficiently exclude the small Na+ ion to maintain infected cell osmotic stability. Here, we examine possible mechanisms for this remarkable solute selectivity. We identify guanidinium as an organic cation with high permeability into human erythrocytes infected with Plasmodium falciparum, but negligible uptake by uninfected cells. Transport characteristics and pharmacology indicate that this uptake is specifically mediated by PSAC. The rank order of organic and inorganic cation permeabilities suggests cation dehydration as the rate-limiting step in transport through the channel. The high guanidinium permeability of infected cells also allows rapid and stringent synchronization of parasite cultures, as required for molecular and cellular studies of this pathogen. These studies provide important insights into how nutrients and ions are transported via PSAC, an established target for antimalarial drug development.

  8. Application of hydrocyclone in no sliming of Itataia (CE) phosphatic rock

    International Nuclear Information System (INIS)

    Figueira, M.E.M.; Pereira, E.F.S.

    1984-01-01

    No sliming of Itataia-Ceara phosphatic rock was studied in hydrocyclone of 40mm diameter, in two atmospheres and with 5% of solids entire of the feed. Different openings of underflow and overflow of hydrocyclone were used. The best condition of no sliming was established in separation of 9,0 μm size, 80% of efficience and 48% of solids in the underflow. (M.A.C.) [pt

  9. Rheological effects of micropolar slime on the gliding motility of bacteria with slip boundary condition

    Science.gov (United States)

    Asghar, Z.; Ali, N.; Anwar Bég, O.; Javed, T.

    2018-06-01

    Gliding bacteria are virtually everywhere. These organisms are phylogenetically diverse with their hundreds of types, different shapes and several modes of motility. One possible mode of gliding motility in the rod shaped bacteria is that they propel themselves by producing undulating waves in their body. Few bacteria glides near the solid surface over the slime without any aid of flagella so the classical Navier-Stokes equations are incapable of explaining the slime rheology at the microscopic level. Micropolar fluid dynamics however provides a solid framework for mimicking bacterial physical phenomena at both micro and nano-scales, and therefore we use the micropolar fluid to characterize the rheology of a thin layer of slime and its dominant microrotation effects. It is also assumed that there is a certain degree of slip between slime and bacterial undulating surface and also between slime and solid substrate. The flow equations are formulated under long wavelength and low Reynolds number assumptions. Exact expressions for stream function and pressure gradient are obtained. The speed of the gliding bacteria is numerically calculated by using a modified Newton-Raphson method. Slip effects and effects of non-Newtonian slime parameters on bacterial speed and power are also quantified. In addition, when the glider is fixed, the effects of slip and rheological properties of micropolar slime parameters on the velocity, micro-rotation (angular velocity) of spherical slime particles, pressure rise per wavelength, pumping and trapping phenomena are also shown graphically and discussed in detail. The study is relevant to emerging biofuel cell technologies and also bacterial biophysics.

  10. High Cost/High Risk Components to Chalcogenide Molded Lens Model: Molding Preforms and Mold Technology

    Energy Technology Data Exchange (ETDEWEB)

    Bernacki, Bruce E.

    2012-10-05

    This brief report contains a critique of two key components of FiveFocal's cost model for glass compression molding of chalcogenide lenses for infrared applications. Molding preforms and mold technology have the greatest influence on the ultimate cost of the product and help determine the volumes needed to select glass molding over conventional single-point diamond turning or grinding and polishing. This brief report highlights key areas of both technologies with recommendations for further study.

  11. Rubber molds for investment casting

    International Nuclear Information System (INIS)

    Sibtain, S.N.

    2011-01-01

    The main objective of the project is to investigate different types of molding rubbers used for investment casting. The level of shape complexity which can be achieved by using these rubber molds is also studied. It was almost impossible to make complex shapes molds using metal molds, in that cases rubber molds are very important because they arc flexible and give accurate and precise part dimensions. Turbine blades are hi-tech components with air-foil geometries that have close dimensional tolerances. They are made of super-alloys and manufactured by investment casting. The final blade profile depends upon the dimensional accuracy in each of the processing steps. In the present work experimental study for the production of high quality low cost castings of turbine blades using rubber molds and injected wax patterns is presented. Natural Rubber molds and wax patterns from these molds were made. Different types of molding rubbers were studied including natural rubber, silicone rubber and liquid silicone rubber. It was found that by using rubber molds we can make most complex shape with very less finishing required. The shrinkage was 12% as compared to original master pattern. Rubber molds were made using laboratory hot press. Three layers of rubber above and below the master pattern. After that vulcanization was done by giving temperature and pressure. (author)

  12. Laboratory evaluation of different formulations of Stress Coat? for slime production in goldfish (Carassius auratus) and koi (Cyprinus carpio)

    OpenAIRE

    Shivappa, Raghunath B.; Christian, Larry S.; Law, Jerry M.; Lewbart, Gregory A.

    2017-01-01

    A study was carried out to assess the effect of Stress Coat® on slime production in goldfish (Carassius auratus) and koi (Cyprinus carpio). The study also investigated histological changes that might be associated with slime producing cells, and wound healing in koi. Several formulations of Stress Coat® were investigated and the results showed that polyvinylpyrrolidone (PVP), also known as povidone, an ingredient of Stress Coat®, when used alone, showed significantly higher slime production i...

  13. Ceramic injection molding

    International Nuclear Information System (INIS)

    Agueda, Horacio; Russo, Diego

    1988-01-01

    Interest in making complex net-shape ceramic parts with good surface finishing and sharp tolerances without machining is a driving force for studying the injection molding technique. This method consists of softhening the ceramic material by means of adding some plastic and heating in order to inject the mixture under pressure into a relatively cold mold where solidification takes place. Essentially, it is the same process used in thermoplastic industry but, in the present case, the ceramic powder load ranges between 80 to 90 wt.%. This work shows results obtained from the fabrication of pieces of different ceramic materials (alumina, barium titanate ferrites, etc.) in a small scale, using equipments developed and constructed in the laboratory. (Author) [es

  14. Switch-like reprogramming of gene expression after fusion of multinucleate plasmodial cells of two Physarum polycephalum sporulation mutants

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Pauline; Hoffmann, Xenia-Katharina; Ebeling, Britta; Haas, Markus; Marwan, Wolfgang, E-mail: wolfgang.marwan@ovgu.de

    2013-05-24

    Highlights: •We investigate reprogramming of gene expression in multinucleate single cells. •Cells of two differentiation control mutants are fused. •Fused cells proceed to alternative gene expression patterns. •The population of nuclei damps stochastic fluctuations in gene expression. •Dynamic processes of cellular reprogramming can be observed by repeated sampling of a cell. -- Abstract: Nonlinear dynamic processes involving the differential regulation of transcription factors are considered to impact the reprogramming of stem cells, germ cells, and somatic cells. Here, we fused two multinucleate plasmodial cells of Physarum polycephalum mutants defective in different sporulation control genes while being in different physiological states. The resulting heterokaryons established one of two significantly different expression patterns of marker genes while the plasmodial halves that were fused to each other synchronized spontaneously. Spontaneous synchronization suggests that switch-like control mechanisms spread over and finally control the entire plasmodium as a result of cytoplasmic mixing. Regulatory molecules due to the large volume of the vigorously streaming cytoplasm will define concentrations in acting on the population of nuclei and in the global setting of switches. Mixing of a large cytoplasmic volume is expected to damp stochasticity when individual nuclei deliver certain RNAs at low copy number into the cytoplasm. We conclude that spontaneous synchronization, the damping of molecular noise in gene expression by the large cytoplasmic volume, and the option to take multiple macroscopic samples from the same plasmodium provide unique options for studying the dynamics of cellular reprogramming at the single cell level.

  15. Switch-like reprogramming of gene expression after fusion of multinucleate plasmodial cells of two Physarum polycephalum sporulation mutants

    International Nuclear Information System (INIS)

    Walter, Pauline; Hoffmann, Xenia-Katharina; Ebeling, Britta; Haas, Markus; Marwan, Wolfgang

    2013-01-01

    Highlights: •We investigate reprogramming of gene expression in multinucleate single cells. •Cells of two differentiation control mutants are fused. •Fused cells proceed to alternative gene expression patterns. •The population of nuclei damps stochastic fluctuations in gene expression. •Dynamic processes of cellular reprogramming can be observed by repeated sampling of a cell. -- Abstract: Nonlinear dynamic processes involving the differential regulation of transcription factors are considered to impact the reprogramming of stem cells, germ cells, and somatic cells. Here, we fused two multinucleate plasmodial cells of Physarum polycephalum mutants defective in different sporulation control genes while being in different physiological states. The resulting heterokaryons established one of two significantly different expression patterns of marker genes while the plasmodial halves that were fused to each other synchronized spontaneously. Spontaneous synchronization suggests that switch-like control mechanisms spread over and finally control the entire plasmodium as a result of cytoplasmic mixing. Regulatory molecules due to the large volume of the vigorously streaming cytoplasm will define concentrations in acting on the population of nuclei and in the global setting of switches. Mixing of a large cytoplasmic volume is expected to damp stochasticity when individual nuclei deliver certain RNAs at low copy number into the cytoplasm. We conclude that spontaneous synchronization, the damping of molecular noise in gene expression by the large cytoplasmic volume, and the option to take multiple macroscopic samples from the same plasmodium provide unique options for studying the dynamics of cellular reprogramming at the single cell level

  16. Characterization and Separation Studies of a Fine Sedimentary Phosphate Ore Slime

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2017-06-01

    Full Text Available Detailed characterization and recovery of apatite from a sedimentary phosphate ore slime of a gravity plant of Yichang, China, were investigated. The phosphate ore slime consisted mainly of apatite, quartz, dolomite, and clay. To start with, the ore slime was characterized in sufficient detail to reveal that it is extremely fine in distribution with a d50 of 65 μm. Other different characterizations, such as apatite grain size distribution, apatite liberation, particle density distribution, and theoretical grade recovery, were also analyzed by mineral liberation analyser (MLA. Based on the results, a new gravity-flotation process, which was comprised of spiral gravity and reverse flotation, was proposed to process the slime. In the new process, the apatite was firstly recovered by two-stage spiral gravity, avoiding direct flotation. The gravity concentrate was the feed for the reverse flotation. A phosphate concentrate of 30.51% P2O5 with a P2O5 recovery of 89.00% can be produced from the slime analyzing 24.25% P2O5. Compared to the conventional direct-reverse flotation process, it was found that the reagent cost of the new gravity-flotation process was lower a quarter than that of the direct-reverse flotation flowsheet.

  17. Characterization of Raw and Decopperized Anode Slimes from a Chilean Refinery

    Science.gov (United States)

    Melo Aguilera, Evelyn; Hernández Vera, María Cecilia; Viñals, Joan; Graber Seguel, Teófilo

    2016-04-01

    This work characterizes raw and decopperized slimes, with the objective of identifying the phases in these two sub-products. The main phases in copper anodes are metallic copper, including CuO, which are present in free form or associated with the presence of copper selenide or tellurides (Cu2(Se,Te)) and several Cu-Pb-Sb-As-Bi oxides. During electrorefining, the impurities in the anode release and are not deposited in the cathode, part of them dissolving and concentrated in the electrolyte, and others form a raw anode slime that contains Au, Ag, Cu, As, Se, Te and PGM, depending on the composition of the anode. There are several recovery processes, most of which involve acid leaching in the first step to dissolve copper, whose product is decopperized anode slime. SEM analysis revealed that the mineralogical species present in the raw anode slime under study were mainly eucarite (CuAgSe), naumannite (Ag2Se), antimony arsenate (SbAsO4), and lead sulfate (PbSO4). In the case of decopperized slime, the particles were mainly composed of SbAsO4 (crystalline appearance), non-stoichiometric silver selenide (Ag(2- x)Se), and chlorargyrite (AgCl).

  18. Hagfish slime threads as a biomimetic model for high performance protein fibres

    International Nuclear Information System (INIS)

    Fudge, Douglas S; Hillis, Sonja; Levy, Nimrod; Gosline, John M

    2010-01-01

    Textile manufacturing is one of the largest industries in the world, and synthetic fibres represent two-thirds of the global textile market. Synthetic fibres are manufactured from petroleum-based feedstocks, which are becoming increasingly expensive as demand for finite petroleum reserves continues to rise. For the last three decades, spider silks have been held up as a model that could inspire the production of protein fibres exhibiting high performance and ecological sustainability, but unfortunately, artificial spider silks have yet to fulfil this promise. Previous work on the biomechanics of protein fibres from the slime of hagfishes suggests that these fibres might be a superior biomimetic model to spider silks. Based on the fact that the proteins within these 'slime threads' adopt conformations that are similar to those in spider silks when they are stretched, we hypothesized that draw processing of slime threads should yield fibres that are comparable to spider dragline silk in their mechanical performance. Here we show that draw-processed slime threads are indeed exceptionally strong and tough. We also show that post-drawing steps such as annealing, dehydration and covalent cross-linking can dramatically improve the long-term dimensional stability of the threads. The data presented here suggest that hagfish slime threads are a model that should be pursued in the quest to produce fibres that are ecologically sustainable and economically viable.

  19. Enhanced Injection Molding Simulation of Advanced Injection Molds

    Directory of Open Access Journals (Sweden)

    Béla Zink

    2017-02-01

    Full Text Available The most time-consuming phase of the injection molding cycle is cooling. Cooling efficiency can be enhanced with the application of conformal cooling systems or high thermal conductivity copper molds. The conformal cooling channels are placed along the geometry of the injection-molded product, and thus they can extract more heat and heat removal is more uniform than in the case of conventional cooling systems. In the case of copper mold inserts, cooling channels are made by drilling and heat removal is facilitated by the high thermal conductivity coefficient of copper, which is several times that of steel. Designing optimal cooling systems is a complex process; a proper design requires injection molding simulations, but the accuracy of calculations depends on how precise the input parameters and boundary conditions are. In this study, three cooling circuit designs and three mold materials (Ampcoloy 940, 1.2311 (P20 steel, and MS1 steel were used and compared using numerical methods. The effect of different mold designs and materials on cooling efficiency were examined using calculated and measured results. The simulation model was adjusted to the measurement results by considering the joint gap between the mold inserts.

  20. Interactions between heavy metals and sewer slimes. Wechselwirkungen zwischen Schwermetallen und Sielhaut

    Energy Technology Data Exchange (ETDEWEB)

    Gutekunst, B.

    1989-09-01

    Sewer slimes in wastewater pipes are an efficient means for detecting heavy metals discharged into the sewer system. The chances and limits of this method are discussed on the basis of the interactions between the heavy metals and the sewer slime. Chemical processes which lead to an accumulation of heavy metals are precipitation, adsorption and sedimentation. The mobilization is due to dissolution, desorption and complexation. The dependency of the waste water parameters pH, redox potential, heavy metal concentration and speciation on the accumulation and mobilization of the heavy metals is investigated as well as the binding capacity and strength. The heavy metals speciations in sewer slime are estimated by the application of a sequential leaching technique. Finally the practical significance of the experiments is shown. (orig.).

  1. Ocean sunfish as indicators for the 'rise of slime'.

    Science.gov (United States)

    Grémillet, David; White, Craig R; Authier, Matthieu; Dorémus, Ghislain; Ridoux, Vincent; Pettex, Emeline

    2017-12-04

    Overfishing and ocean warming are drastically altering the community composition and size structure of marine ecosystems, eliminating large bodied species [1]. Against a backdrop of such environmental change, the heaviest of all bony fish, the ocean sunfish (Mola mola), seems an improbable survivor. Indeed this indolent giant is killed globally as bycatch, and is listed as 'Vulnerable'[2]. We undertook the most extensive aerial surveys of sunfish ever conducted and found surprisingly high abundances off the Atlantic and Mediterranean coasts of Western Europe. With up to 475 individuals per 100 km 2 , these figures are one order of magnitude higher than abundance estimates for other areas [3-5]. Using bioenergetic modelling, we estimate that each sunfish requires 71 kg day -1 of jellyfish, a biomass intake more than an order of magnitude greater than predicted for a similarly sized teleost. Scaled up to the population level, this equates to a remarkable 20,774 tonnes day -1 of predated jellyfish across our study area in summer. Sunfish abundance may be facilitated by overfishing and ocean warming, which together cause reduced predation of sunfish by sharks and elevated jellyfish biomass. Our combined survey and bioenergetic data provide the first-ever estimate of spatialized ocean sunfish daily food requirements, and stress the importance of this species as a global indicator for the 'rise of slime'. This hypothesis posits that, in an overfished world ocean exposed to global warming, gelatinous zooplankton should flourish, to the detriment of other mesotrophic species such as small pelagic fish, causing irreversible trophic cascades as well as a series of other environmental and economic issues. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Performance of molded plastic scintillators

    International Nuclear Information System (INIS)

    Gen, N.S.; Leman, V.E.; Solomonov, V.M.

    1989-01-01

    The performance of molded plastic scintillators is studied. The plastic scintillators studied were formed by transfer molding and intrusion from a scintillation composition consisting of polystyrene and a standard system of luminescent additives: 2 mass % of paraterphenyl + 0.06 mass % 1,4-di-/2-[5-phenyloxazoyly]/benzene and a plasticizer. The combined effect of mechanical load and temperature was studied. The effect of radiation on molded plastic scintillators was studied using gamma radiation from a 60 Co source. The studies show that the main operating characteristics of molded plastic scintillators are on a par with those of polymerized plastic scintillators. At the same time, molded plastic scintillators are superior in thermal stability at temperatures below the glass transition temperature and with respect to their working temperature range

  3. Anti-plasmodial activity of Dicoma tomentosa (Asteraceae) and identification of urospermal A-15-O-acetate as the main active compound

    Science.gov (United States)

    2012-01-01

    Background Natural products could play an important role in the challenge to discover new anti-malarial drugs. In a previous study, Dicoma tomentosa (Asteraceae) was selected for its promising anti-plasmodial activity after a preliminary screening of several plants traditionally used in Burkina Faso to treat malaria. The aim of the present study was to further investigate the anti-plasmodial properties of this plant and to isolate the active anti-plasmodial compounds. Methods Eight crude extracts obtained from D. tomentosa whole plant were tested in vitro against two Plasmodium falciparum strains (3D7 and W2) using the p-LDH assay (colorimetric method). The Peters’ four-days suppressive test model (Plasmodium berghei-infected mice) was used to evaluate the in vivo anti-plasmodial activity. An in vitro bioguided fractionation was undertaken on a dichloromethane extract, using preparative HPLC and TLC techniques. The identity of the pure compound was assessed using UV, MS and NMR spectroscopic analysis. In vitro cytotoxicity against WI38 human fibroblasts (WST-1 assay) and haemolytic activity were also evaluated for extracts and pure compounds in order to check selectivity. Results The best in vitro anti-plasmodial results were obtained with the dichloromethane, diethylether, ethylacetate and methanol extracts, which exhibited a high activity (IC50 ≤ 5 μg/ml). Hot water and hydroethanolic extracts also showed a good activity (IC50 ≤ 15 μg/ml), which confirmed the traditional use and the promising anti-malarial potential of the plant. The activity was also confirmed in vivo for all tested extracts. However, most of the active extracts also exhibited cytotoxic activity, but no extract was found to display any haemolytic activity. The bioguided fractionation process allowed to isolate and identify a sesquiterpene lactone (urospermal A-15-O-acetate) as the major anti-plasmodial compound of the plant (IC50 < 1 μg/ml against both 3D7 and W2 strains). This was also

  4. Sulfide flux formed by the anaerobic slime on the surface of the gravity sewer pipe wall. Shizen ryuka no gesuikan ni okeru kenki slime kara no ryukabutsu flux

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimoto, K. (Japan Sewage Works Agency, Tokyo (Japan)); Mori, T. (Shimane Univ., Shimane (Japan). Faculty of Agriculture)

    1992-09-10

    A part of sulfide dissolved in the sewage is oxidized by oxygen dissolved in the sewage from the gas phase inside by the re-aeration. In addition, a part of type of the dissolvable sulfides is diffused in the gas phase as a hydrogen sulfide gas by the turbulence and so on in the sewage. When hydrogen sulfide diffused in the gas phase is oxidized to sulfuric acid by the sulfur oxidation bacteria, the corrosion and deterioration of concrete by that sulfuric acid are concerned even in the gravity sewer pipe as same as in the sewer pipe downstream from the discharge opening of the pressurized transport pipe for a long distance. When the gravity sewer pipe is planned and designed, it is required for establishing the necessary countermeasure at the places where the generation of sulfide is predicted, by estimating the sulfide concentration in the sewage accurately. In this report, making the slime adhered on the gravity sewer pipe wall and the slime grown in the laboratory as the objects, some knowledges on the sulfide flux from the anaerobic slime were obtained by measuring the sulfide flux and so forth. 16 refs., 4 figs., 3 tabs.

  5. Hänsel, Gretel and the slime mould—how an external spatial memory aids navigation in complex environments

    Science.gov (United States)

    Smith-Ferguson, Jules; Reid, Chris R.; Latty, Tanya; Beekman, Madeleine

    2017-10-01

    The ability to navigate through an environment is critical to most organisms’ ability to survive and reproduce. The presence of a memory system greatly enhances navigational success. Therefore, natural selection is likely to drive the creation of memory systems, even in non-neuronal organisms, if having such a system is adaptive. Here we examine if the external spatial memory system present in the acellular slime mould, Physarum polycephalum, provides an adaptive advantage for resource acquisition. P. polycephalum lays tracks of extracellular slime as it moves through its environment. Previous work has shown that the presence of extracellular slime allows the organism to escape from a trap in laboratory experiments simply by avoiding areas previously explored. Here we further investigate the benefits of using extracellular slime as an external spatial memory by testing the organism’s ability to navigate through environments of differing complexity with and without the ability to use its external memory. Our results suggest that the external memory has an adaptive advantage in ‘open’ and simple bounded environments. However, in a complex bounded environment, the extracellular slime provides no advantage, and may even negatively affect the organism’s navigational abilities. Our results indicate that the exact experimental set up matters if one wants to fully understand how the presence of extracellular slime affects the slime mould’s search behaviour.

  6. Hänsel, Gretel and the slime mould—how an external spatial memory aids navigation in complex environments

    International Nuclear Information System (INIS)

    Smith-Ferguson, Jules; Latty, Tanya; Beekman, Madeleine; Reid, Chris R

    2017-01-01

    The ability to navigate through an environment is critical to most organisms’ ability to survive and reproduce. The presence of a memory system greatly enhances navigational success. Therefore, natural selection is likely to drive the creation of memory systems, even in non-neuronal organisms, if having such a system is adaptive. Here we examine if the external spatial memory system present in the acellular slime mould, Physarum polycephalum , provides an adaptive advantage for resource acquisition. P. polycephalum lays tracks of extracellular slime as it moves through its environment. Previous work has shown that the presence of extracellular slime allows the organism to escape from a trap in laboratory experiments simply by avoiding areas previously explored. Here we further investigate the benefits of using extracellular slime as an external spatial memory by testing the organism’s ability to navigate through environments of differing complexity with and without the ability to use its external memory. Our results suggest that the external memory has an adaptive advantage in ‘open’ and simple bounded environments. However, in a complex bounded environment, the extracellular slime provides no advantage, and may even negatively affect the organism’s navigational abilities. Our results indicate that the exact experimental set up matters if one wants to fully understand how the presence of extracellular slime affects the slime mould’s search behaviour. (paper)

  7. Slime production and antibiotic susceptibility in staphylococci isolated from clinical samples

    Directory of Open Access Journals (Sweden)

    Seza Arslan

    2007-02-01

    Full Text Available A total of 187 isolates from several clinical specimens were identified to species level as 129 Staphylococcus aureus strains and 58 coagulase-negative staphylococci (CNS strains by the API Staph System (Biomerieux. Slime production was detected both by the conventional Christensen's method as well as by the Congo red agar method. Seventy-two strains of staphylococci isolates (38.5% were found to be slime producers by Christensen's test tube method whereas 58 strains (31% were slime positive with Congo red agar method. There was no statistically significant difference between the two methods for the detection of slime production (P > 0.05. Susceptibility of isolates against antimicrobial agents was tested by the disk diffusion method. Staphylococcal species had resistance to one or more antibiotics. Among the various antimicrobial agents, oxacillin (71.1% and erythromycin (47.1% showed higher resistance than most of the agents used against all isolates. Oxacillin resistant S. aureus (ORSA and oxacillin resistant coagulase-negative staphylococci (ORCNS, 97 (75.2% and 36 (62.1% respectively were frequently observed in strains isolated from clinical materials. Among the ORSA strains, two strains were resistant to vancomycin. Moreover, 96 (74.4% of 129 S. aureus strains were positive for blactamase enzyme. However, 78 (81.25% of 96 b-lactamase positive S. aureus strains were b-lactamase positive ORSA isolates, but none of them had vancomycin resistance.

  8. Rapid control of mold temperature during injection molding process

    Energy Technology Data Exchange (ETDEWEB)

    Liparoti, Sara; Titomanlio, Giuseppe [Department of Industrial Engineering, University of Salerno Via Giovanni Paolo II, 132, 84084 Fisciano (Italy); Hunag, Tsang Min; Cakmak, Mukerrem [Department of Polymer Engineering, The University of Akron, Akron, OH 44325 (United States); Sorrentino, Andrea [Institute for Polymers, Composite and Biomaterials (IPCB) - CNR, P. Enrico Fermi 1, 80055 Portici (Italy)

    2015-05-22

    The control of mold surface temperature is an important factor that determines surface morphology and its dimension in thickness direction. It can also affect the frozen molecular orientation and the mold surface replicability in injection molded products. In this work, thin thermally active films were used to quickly control the mold surface temperature. In particular, an active high electrical conductivity carbon black loaded polyimide composites sandwiched between two insulating thin polymeric layers was used to condition the mold surface. By controlling the heating time, it was possible to control precisely the temporal variation of the mold temperature surface during the entire cycle. The surface heating rate was about 40°C/s and upon contact with the polymer the surface temperature decreased back to 40°C within about 5 s; the overall cycle time increased only slightly. The effect on cross section sample morphology of samples of iPP were analyzed and discussed on the basis of the recorded temperature evolution.

  9. Functional nanostructures on injection molded plastic

    DEFF Research Database (Denmark)

    Johansson, Alicia Charlotte; Søgaard, Emil; Andersen, Nis Korsgaard

    Nanotechnology can be used to make inexpensive plastic parts with functional surfaces. The plastic parts can be molded using a standard injection molding process. The nanostructures are directly transferred from the surface of the molding tool to the surface of the molded plastic part during...

  10. Injection Molding of High Aspect Ratio Nanostructures

    DEFF Research Database (Denmark)

    Matschuk, Maria; Larsen, Niels Bent

    We present a process for injection molding of 40 nm wide and >100 nm high pillars (pitch: 200 nm). We explored the effects of mold coatings and injection molding conditions on the replication quality of nanostructures in cyclic olefin copolymer. We found that optimization of molding parameters...

  11. Sewer slime analysis as a method of spotting heavy metal bearing waste water discharge. Sielhautuntersuchungen zur Einkreisung schwermetallhaltiger Einleitungen

    Energy Technology Data Exchange (ETDEWEB)

    Gutekunst, B.

    1988-01-01

    The sewer slime method, in analogy to sediment analyses, informs about the discharges which are polluted with heavy metals and fed into the public sewage system at specific points, independent of the time of discharge. The sewer slime consisting of bacteria, fungi, organic and inorganic compounds concentrates heavy metals by sedimentation, adsorption and precipitation processes and thus represents a pollution indicator. This study characterizes sewer slimes by means of physical properties and by analysis of the chemical and biological composition. The mechanisms of heavy metal enrichment and reduction under altered environmental conditions are analyzed using the elements Pb, Cd, Cu, Ni and Zn as examples. (RB).

  12. White mold of Jerusalem artichoke

    Science.gov (United States)

    Jerusalem artichoke (Helianthus tuberosus) is a Native American food plant closely related to the common sunflower (Helianthus annuus). Tubers of Jerusalem artichoke are increasingly available in retail grocery outlets. White mold (Sclerotinia stem rot), caused by the fungus, Sclerotinia sclerotioru...

  13. Molded polymer solar water heater

    Science.gov (United States)

    Bourne, Richard C.; Lee, Brian E.

    2004-11-09

    A solar water heater has a rotationally-molded water box and a glazing subassembly disposed over the water box that enhances solar gain and provides an insulating air space between the outside environment and the water box. When used with a pressurized water system, an internal heat exchanger is integrally molded within the water box. Mounting and connection hardware is included to provide a rapid and secure method of installation.

  14. Evaluation of the Anti-plasmodial Activity of the Methanolic Root Extracts of Anthocleista nobilis G. Don, Nauclea latifolia Smith and Napoleona imperialis P. Beauv

    OpenAIRE

    Ijeoma H. Ogbuehi; Omotayo O. Ebong; Eme O. Asuquo; Chijioke A. Nwauche

    2014-01-01

    The emergence of resistant strains of the malaria parasite has necessitated the continued search for other effective, safe and cheap plant-based anti-malarial agents. This study was carried out to evaluate in vivo the anti-plasmodial effect of the extract of a combination of three plants as used in traditional medicine in South-east, Nigeria. Dried and ground roots of the three plants: Anthocleista nobilis, Nauclea latifolia and Napoleona imperialis were extracted in 70% methanol as a combina...

  15. Myxosporean plasmodial infection associated with ulcerative lesions in young-of-the-year Atlantic menhaden in a tributary of the Chesapeake Bay, and possible links to Kudoa clupeidae

    Science.gov (United States)

    Reimschuessel, R.; Gieseker, C.M.; Driscoll, C.; Baya, A.; Kane, A.S.; Blazer, V.S.; Evans, J.J.; Kent, M.L.; Moran, J.D.W.; Poynton, S.L.

    2003-01-01

    Ulcers in Atlantic menhaden Brevoortia tyrannus (Latrobe) (Clupeidae), observed along the USA east coast, have been attributed to diverse etiologies including bacterial, fungal and, recently, harmful algal blooms. To understand the early pathogenesis of these lesions, we examined juvenile Atlantic menhaden collected during their seasonal presence in Chesapeake Bay tributaries from April to October 1999 and from March to August 2000. We conducted histopathological examinations of young-of-the-year fish from the Pocomoke River tributary, which has a history of fish mortalities and high lesion prevalence. Kudoa clupeidae (Myxozoa: Myxosporea) spores were present in the muscles of fish collected in both years. Of the fish assessed by histology in April, 5 to 14% were infected, while in May 90 to 96% were infected. Infection rates remained high during the summer. Mature spores were primarily located within myomeres and caused little or no observable pathological changes. Ultrastructure showed spores with capsulogenic cells bearing filamentous projections, and a basal crescentic nucleus with mottled nucleoplasm containing cleaved, condensed chromatin. Also, a highly invasive plasmodial stage of a myxozoan was found in the lesions of juvenile Atlantic menhaden. The plasmodia were observed in fish collected between May and July, with the maximum occurrence in late June 1999 and late May 2000. Plasmodia penetrated and surrounded muscle bundles, causing grossly observable raised lesions in 73% of all fish infected with this invasive stage. Plasmodia were also detected in the visceral organs, branchial arches, and interocular muscles of some fish. Some of the invasive extrasporogonic plasmodial lesions were associated with ulcers and chronic inflammatory infiltrates. The plasmodial stage appeared to slough out of the tissue with subsequent evidence of wound healing. Ultrastructure showed plasmodia with an elaborate irregular surface, divided into distinct ectoplasm and

  16. The Gelation of Polyvinyl Alcohol with Borax: A Novel Class Participation Experiment Involving the Preparation and Properties of a "Slime."

    Science.gov (United States)

    Casassa, E. Z.; And Others

    1986-01-01

    Background information, procedures used, and typical results obtained are provided for an experiment in which students prepare and study the characteristics of a "slime." A list of general, inorganic, and polymer chemistry concepts fostered in the experiment is included. (JN)

  17. Atividade enzimática, produção de slime e sensibilidade a antifúngicos de Candida sp Enzymatic activity, slime production and antifungal agent sensitivity of Candida sp

    Directory of Open Access Journals (Sweden)

    Jaqueline Otero Silva

    2007-06-01

    Full Text Available A habilidade de Candida spp secretar enzimas extracelulares e slime tem sido associada como fatores de patogenicidade. Do total de 37 cepas de Candida sp, 100% foram produtoras de proteinase, 83,8% fosfolipase, 64,9% slime e 100% sensíveis ao fluconazol e itraconazol. Foram encontradas 17 tipagens (enzima/slime. Esta metodologia apresentou um bom índice discriminatório (D=0,93 podendo ser utilizado na caracterização fenotípica das leveduras.Abilith of Candida spp to secrete extracellular enzymes and slime has been associated as pathogenicity factors. Out of a total of 37 strains of Candida sp, 100% were proteinase producers, 83.8% were phospholipase producers, 64.9% were slime producers and 100% were sensitive to fluconazole and itraconazole. Seventeen typings (enzymes/slime were found. This methodology presented a good discrimination rate (D = 0.93 and could be used for phenotypic characterization of yeasts.

  18. Comparison of slime-producing coagulase-negative Staphylococcus colonization rates on vinyl and ceramic tile flooring materials.

    Science.gov (United States)

    Yazgi, H; Uyanik, M H; Ayyildiz, A

    2009-01-01

    This study investigated the colonization of slime-producing coagulase-negative Staphylococcus (CoNS) in 80 patient wards in Turkey (40 vinyl and 40 ceramic tile floors). A total of 480 samples that included 557 CoNS isolates were obtained. Slime production was investigated with the Christensen method and methicillin-susceptibility was tested by the disk-diffusion method. There was a significant difference in the percentage of slime-producing CoNS isolates on vinyl (12.4%) versus ceramic tile flooring (4.4%). From vinyl flooring, the percentage of slime producing methicillin-resistant CoNS (MRCoNS) (8.9%) was significantly higher than for methicillin-sensitive CoNS (MSCoNS) (3.6%), whereas there was no difference from ceramic tile flooring (2.5% MRCoNS versus 1.8% MSCoNS). The most commonly isolated slime-producing CoNS species was S. epidermidis on both types of flooring. It is concluded that vinyl flooring seems to be a more suitable colonization surface for slime-producing CoNS than ceramic tile floors. Further studies are needed to investigate bacterial strains colonized on flooring materials, which are potential pathogens for nosocomial infections.

  19. Study on the flotation technology for deep-cleaning of coal slime

    Energy Technology Data Exchange (ETDEWEB)

    Fu Xiao-heng; Shan Xiao-yun; Jiang He-jin; Li Xiang-li [China University of Mining and Technology, Beijing (China). School of Chemical and Environmental Engineering

    2006-07-01

    The paper introduced the basic principle and special features of deep-cleaning of coal slime by flotation, first, separating the slime by conventional flotation to give a relatively low ash concentrate, a tailing containing an ash as high as possible, followed by flocculation-flotation to recover additional low ash concentrate. The regressive release flotation test and microphoto indicated that the middling consists mainly of intergrowth particles of coal and minerals. Comparison between deep-cleaning and conventional flotation results denoted that, at approximately same concentrate ash, its yield by deep-cleaning was 46.06 percent point higher, and at similar yield, its concentrate ash, 1.78 percent point lower. The performance by deep-cleaning is even better than that by regressive release flotation test. 4 refs., 2 figs., 6 tabs.

  20. Dolochar as a reductant in the reduction roasting of iron ore slimes

    Science.gov (United States)

    Rath, Swagat S.; Rao, Danda Srinivas

    2017-12-01

    The present investigation examines the viability of dolochar, a sponge iron industry waste material, as a reductant in the reduction roasting of iron ore slimes, which are another waste generated by iron ore beneficiation plants. Under statistically determined optimum conditions, which include a temperature of 900°C, a reductant-to-feed mass ratio of 0.35, and a reduction time of 30-45 min, the roasted mass, after being subjected to low-intensity magnetic separation, yielded an iron ore concentrate of approximately 64wt% Fe at a mass recovery of approximately 71% from the feed iron ore slime assaying 56.2wt% Fe. X-ray diffraction analyses indicated that the magnetic products contain magnetite and hematite as the major phases, whereas the nonmagnetic fractions contain quartz and hematite.

  1. Process for molding improved polyethylene

    International Nuclear Information System (INIS)

    Kanai, Masanori; Aine, Norio; Nakada, Shinsaku.

    1962-01-01

    Various configurations in size and shape of polyethylene are molded by: (a) irradiating powders of polyethylene with ionizing radiations in the presence of oxygen to the extent of producing substantially no cross-linking among the molecules of polyethylene, and thereafter (b) molding the thus irradiated powders of polyethylene at 100-250 0 C to cross-link the molding. In this process, a uniform and desirable degree of cross-linking and any desirable configuration are provided for the polyethylene molding. Any extruder and any molding machine producing heat can be employed in this process. In embodiments, the radiation dose units may preferably be 1x10 6 to 1.5x10 7 roentgen. The ionizing radiations may be X-rays, gamma-rays or electron beams, but preferably gamma-rays. The preheating prior to molding may be effected in vacuum, in inert gas, or in oxygen at 100-250 0 C, but preferably in oxygen at 100 0 C. In an example, a polyethylene powder of 100 mesh was irradiated with gamma-rays from a Co-60 source with a dose of 3.1x10 6 r at a dose rate of 5.5x10 4 r/hr in air, then preheated in air at 80 0 C for 1 hr, and finally extruded to form a rod of 5 mm phi at 200 0 C. max. The degree of product cross-linking was 0% after irradiation in step (a), and 38% after heating in step (b). (Iwakiri, K.)

  2. Multi-element sewer slime impact pattern--a quantitative characteristic enabling identification of the source of heavy metal discharges into sewer systems.

    Science.gov (United States)

    Kintrup, J; Wünsch, G

    2001-11-01

    The capability of sewer slime to accumulate heavy metals from municipal wastewater can be exploited to identify the sources of sewage sludge pollution. Former investigations of sewer slime looked for a few elements only and could, therefore, not account for deviations of the enrichment efficiency of the slime or for irregularities from sampling. Results of ICP-MS multi element determinations were analyzed by multivariate statistical methods. A new dimensionless characteristic "sewer slime impact" is proposed, which is zero for unloaded samples. Patterns expressed in this data format specifically extract the information required to identify the type of pollution and polluter quicker and with less effort and cost than hitherto.

  3. Kinetic study on recovery of metal values in anode slime from used lead batteries

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, S.; Nagasaka, T. [Tohoku Univ., Sendai (Japan). Dept. of Environmental Studies; Ono, J.; Hino, M. [Tohoku Univ., Sendai (Japan). Dept. of Metallurgy

    2004-07-01

    Oxidation experiments were conducted with pure antimony and antimony-lead bismuth alloys to examine the oxidation kinetics and mechanisms used to treat the anode slime produced during lead electrorefining and recovery of antimony from used lead batteries. In order to recycle and recover valuable metals from the used lead batteries, the oxidation experiments were conducted with pure liquid antimony at temperatures between 973 and 1373 K. The study showed that the gas phase mass transfer step is the basic mechanisms that controls the oxidation rate for pure antimony. It was noted that the oxidation rate of the alloy was identical to that of the pure antimony, suggesting that an oxidation reaction of the anode slime proceeds at the same rate as pure antimony. This is one of the advantages of treating anode slime through oxidation. Mass transfer in the gas phase was the rate-determining step in the alloy oxidation reaction. It was concluded that a higher oxygen partial pressure and sufficient gas flow rate at temperature of 1073 K is needed to conserve energy and recovery antimony oxide. 13 refs., 2 tabs., 12 figs.

  4. Shallow irradiation of vienna sausage by electron beams in preventation of the slime production

    International Nuclear Information System (INIS)

    Watanabe, Hiroshi; Kume, Tamikazu; Ito, Hitoshi; Aoki, Shohei; Sato, Tomotaro

    1975-01-01

    Vienna sausages get spoiled by slime production or putrefaction due to the propagation of microorganisms when stored for 3 to 5 days at 10 deg C. The radiation pasteurization of vienna sausages has mainly been studied with gamma irradiation. The slime of sausages is believed to be microorganisms themselves growing on the surface of the sausages. Pasteurization of the surface of vienna sausages with electron irradiation was thus investigated. The results obtained are as follows: The vienna sausages irradiated with a dose of 0.8 to approximately 1.0 Mrad by 0.5 MeV electrons could be stored without slime production or putrefaction for more than a week at 11 deg C. The effect of pasteurization increased with energy and dose of electrons. However, the changes in the organoleptic qualities of vienna sausages were detected when irradiated with a dose of over 0.7 Mrad by 2.0 MeV electrons. Consequently, the irradiation with a dose of 1.0 Mrad by 1.0 MeV electrons was effectual in lengthening their shelf-life without deterioration of the organoleptic qualities. (author)

  5. Facts about Stachybotrys chartarum and Other Molds

    Science.gov (United States)

    ... there is moisture from water damage, excessive humidity, water leaks, condensation, water infiltration, or flooding. Constant moisture is ... visible mold. The conditions causing mold (such as water leaks, condensation, infiltration, or flooding) should be corrected to ...

  6. Silane based coating of aluminium mold

    DEFF Research Database (Denmark)

    2013-01-01

    having at least one closed cavity is provided, at least one surface of the at least one cavity being an aluminium surface coated with a silane based coating layer. The silane based anti-stiction coating improves the anti-stiction properties of the mold which may allow for molding and demolding...... of structures which would otherwise be difficult to mold. The resistance of the coated aluminium mold is significantly improved by applying a silane-based coating layer....

  7. Mold production for polymer optics

    Science.gov (United States)

    Boerret, Rainer; Raab, Jonas; Speich, Marco

    2014-09-01

    The fields of application for polymer optics are huge and thus the need for polymer optics is steadily growing. Most polymer optics are produced in high numbers by injection molding. Therefore molds and dies that fulfill special requirements are needed. Polishing is usually the last process in the common process chain for production of molds for polymer optics. Usually this process step is done manually by experienced polishers. Due to the small number of skilled professionals and health problems because of the monotonous work the idea was to support or probably supersede manual polishing. Polishing using an industrial robot as movement system enables totally new possibilities in automated polishing. This work focuses on the surface generation with a newly designed polishing setup and on the code generation for the robot movement. The process starts on ground surfaces and with different tools and polishing agents surfaces that fulfill the requirements for injection molding of optics can be achieved. To achieve this the attention has to be focused not only on the process itself but also on tool path generation. A proprietary software developed in the Centre for Optical Technologies in Aalen University allows the tool path generation on almost any surface. This allows the usage of the newly developed polishing processes on different surfaces and enables an easy adaption. Details of process and software development will be presented as well as results from different polishing tests on different surfaces.

  8. Environmental Sustainability and Mold Hygiene in Buildings.

    Science.gov (United States)

    Wu, Haoxiang; Ng, Tsz Wai; Wong, Jonathan Wc; Lai, Ka Man

    2018-04-04

    Environmental sustainability is one of the key issues in building management. In Hong Kong, one of the initiatives is to reduce the operation hours of air-conditioning in buildings to cut down energy consumption. In this study, we reported a mold contamination case in a newly refurbished laboratory, in which the air-conditioner was switched from 24- to 18-h mode after refurbishment. In order to prevent mold recurrence, the air-conditioner was switched back to 24-h mode in the laboratory. During the mold investigation, visible mold patches in the laboratory were searched and then cultured, counted and identified. Building and environmental conditions were recorded, and used to deduce different causes of mold contamination. Eight contaminated sites including a wall, a bench, some metal and plastic surfaces and seven types of molds including two Cladosporium spp., two Aspergillus spp., one Rhizopus sp., one Trichoderma sp., and one Tritirachium sp. were identified. Cladosporium spp. were the most abundant and frequently found molds in the laboratory. The contaminated areas could have one to five different species on them. Based on the mold and environmental conditions, several scenarios causing the mold contamination were deduced, and different mold control measures were discussed to compare them with the current solution of using 24-h air-conditioning to control mold growth. This study highlights the importance of mold hygiene in sustainable building management.

  9. Environmental Sustainability and Mold Hygiene in Buildings

    Directory of Open Access Journals (Sweden)

    Haoxiang Wu

    2018-04-01

    Full Text Available Environmental sustainability is one of the key issues in building management. In Hong Kong, one of the initiatives is to reduce the operation hours of air-conditioning in buildings to cut down energy consumption. In this study, we reported a mold contamination case in a newly refurbished laboratory, in which the air-conditioner was switched from 24- to 18-h mode after refurbishment. In order to prevent mold recurrence, the air-conditioner was switched back to 24-h mode in the laboratory. During the mold investigation, visible mold patches in the laboratory were searched and then cultured, counted and identified. Building and environmental conditions were recorded, and used to deduce different causes of mold contamination. Eight contaminated sites including a wall, a bench, some metal and plastic surfaces and seven types of molds including two Cladosporium spp., two Aspergillus spp., one Rhizopus sp., one Trichoderma sp., and one Tritirachium sp. were identified. Cladosporium spp. were the most abundant and frequently found molds in the laboratory. The contaminated areas could have one to five different species on them. Based on the mold and environmental conditions, several scenarios causing the mold contamination were deduced, and different mold control measures were discussed to compare them with the current solution of using 24-h air-conditioning to control mold growth. This study highlights the importance of mold hygiene in sustainable building management.

  10. Mold inhibition on unseasoned southern pine

    Science.gov (United States)

    Carol A. Clausen; Vina W. Yang

    2003-01-01

    Concerns about indoor air quality due to mold growth have increased dramatically in the United States. In the absence of moisture management, fungicides need to be developed for indoor use to control mold establishment. An ideal fungicide for prevention of indoor mold growth on wood-based materials needs to specifically prevent spore germination and provide long-term...

  11. Surface Replication of Molded Products with Microneedle Features in Injection Molding

    Science.gov (United States)

    Uchiumi, Kazuyasu; Takayama, Tetsuo; Ito, Hiroshi; Inou, Akinori

    Micro-molding of microneedle features was conducted using several injection-molding techniques. Injection compression molding and injection molding were performed with supercritical carbon dioxide fluid and with or without vacuum processing inside the mold cavity. Effects of process parameters on processability and surface replication of the molded parts were evaluated. The height replication ratio for microneedles was improved using injection compression molding. At a shorter compression stroke, the needle height was improved, and the influence of compression delay time was also small. Moreover, the effects of vacuum processing inside the mold cavity under the filling process were slight. The height replication ratio for microneedles showed the highest values using injection molding using supercritical carbon dioxide fluid with vacuum inside the mold cavity.

  12. Detection of methicillin resistance and slime factor production of Staphylococcus aureus in bovine mastitis Detecção de resistência a meticilina e produção do fator slime por Staphylococcus aureus em mastite bovina

    Directory of Open Access Journals (Sweden)

    Alper Ciftci

    2009-06-01

    Full Text Available This study aimed to detect methicillin resistant and slime producing Staphylococcus aureus in cases of bovine mastitis. A triplex PCR was optimized targetting 16S rRNA, nuc and mecA genes for detection of Staphylococcus species, S. aureus and methicillin resistance, respectively. Furthermore, for detection of slime producing strains, a PCR assay targetting icaA and icaD genes was performed. In this study, 59 strains were detected as S. aureus by both conventional tests and PCR, and 13 of them were found to be methicillin resistant and 4 (30.7% were positive for mecA gene. Although 22 of 59 (37.2% S. aureus isolates were slime-producing in Congo Red Agar, in PCR analysis only 15 were positive for both icaA and icaD genes. Sixteen and 38 out of 59 strains were positive for icaA and icaD gene, respectively. Only 2 of 59 strains were positive for both methicillin resistance and slime producing, phenotypically, suggesting lack of correlation between methicillin resistance and slime production in these isolates. In conclusion, the optimized triplex PCR in this study was useful for rapid and reliable detection of methicillin resistant S. aureus. Furthermore, only PCR targetting icaA and icaD may not sufficient to detect slime production and further studies targetting other ica genes should be conducted for accurate evaluation of slime production characters of S. aureus strains.Este estudo objetivou a detecção de Staphylococcus aureus resistente a meticilina e produtor do fator slime em casos de mastite bovina. Um PCR triplex foi otimizado, com alvo no genes 16SrRNA, nuc e mecA para detecção de Staphylococcus spp, S. aureus e resistencia a meticilina, respectivamente. Para detecção das cepas produtoras do fator slime, empregou-se um PCR com alvo nos genes icaA e icaD. No estudo, 59 cepas foram identificadas como S. aureus por testes convencionais e PCR, sendo 13 resistentes a meticilina e quatro positivas para o gene mecA. Embora 22 das 59 cepas

  13. Implementation of Molding Constraints in Topology Optimization

    DEFF Research Database (Denmark)

    Marx, S.; Kristensen, Anders Schmidt

    2009-01-01

    In many cases the topology optimization method yield inadmissible solutions in respect to a particular manufacturing process, e.g. injection molding. In the present work it is chosen to focus on the most common injection molding parameters/factors determining the quality of the mold geometry, i.......e. uniform thickness, filling of the die and ejection of the molded item, i.e. extrusion. The mentioned injection mold parameters/factors are introduced in the topology optimization by defining a centerline of the initial domain and then penalize elements in respect to the distance to the defined centerline...

  14. Microstructured metal molds fabricated via investment casting

    International Nuclear Information System (INIS)

    Cannon, Andrew H; King, William P

    2010-01-01

    This paper describes an investment casting process to produce aluminum molds having integrated microstructures. Unlike conventional micromolding tools, the aluminum mold was large and had complex curved surfaces. The aluminum was cast from curved microstructured ceramic molds which were themselves cast from curved microstructured rubber. The aluminum microstructures had an aspect ratio of 1:1 and sizes ranging from 25 to 50 µm. Many structures were successfully cast into the aluminum with excellent replication fidelity, including circular, square and triangular holes. We demonstrate molding of large, curved surfaces having surface microstructures using the aluminum mold.

  15. Investigations to identify organic pollutions in sewer slime. Final report; Untersuchungen zur Identifizierung organischer Schadstoffe in Sielhaeuten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, E.; Sauer, J.; Ripp, C.; Hahn, H.H.

    1997-07-31

    An analytical method to measure organic compounds in sewer slime and sewage sludge has been developed. The method needs no halogenated solvents. Furthermore, the sorption behavior of sewer slime has been investigated. Chlorophenols, as an example of more polar organic compounds, show a more stronger and faster desorption from sewer slime than for example PAH. pH-value and fat-content (resp. content of organic carbon) are the most important parameters affecting the sorption kinetic and sorption capacity of sewer slime. To get comparable results, all datas should be refered to the content of organic carbon of the sewer slime. By constructing pollutions-profiles of parameters like AOX, PCB, Flame Protection Agencies and PAH in the sewers of an industrial area, emissions could be localized. (orig.) [Deutsch] Es wurde eine analytische Methode entwickelt, die es erlaubt, ein breites Spektrum lipophiler organischer Schadstoffe in Sielhaut und Klaerschlamm zu identifizieren, als quantitativ zu bestimmen. Die Methode kommt ohne halogenierte Loesungsmittel aus. Verbindungen, die aufgrund ihrer Wasserunloeslichkeit nicht im Abwasser nachgewiesen werden konnten, koennen durch Sielhautanalyse verfolgt werden. Anhand von Schadstoffprofilen in Nebensammlern eines Industriegebietes konnte beispielhaft die Lokalisierung von punktfoermigen Schadstoffeinleitungen demonstriert werden. Erfolgreich verlief auch die Identifizierung eines AOX-Emittenten. Ebenso sind die Eintragspfade von Stoffen, die im Verdacht stehen, endokrine Wirkungen zu haben mit Sielhautanalyse aufklaerbar. Das Sorptionsverhalten der Sielhaut wird durch Faktoren, wie pH und Fettgehalt gepraegt. Bei der Auswertung der Proben muessen die Werte auf den organischen Kohlenstoffgehalt bezogen werden. (orig.)

  16. New South African complex leaches gold, uranium, and sulphur from slimes

    Energy Technology Data Exchange (ETDEWEB)

    Payne, A.

    1978-01-01

    Slimes dams at various mines in the Orange Free State and the Transvaal are being re-treated to recover U, Au, and H/sub 2/SO/sub 4/. Components of the Free State Metallurgical Complex include flotation plants, a uranium plant, the President Brand plant for H/sub 2/SO/sub 4/ production from the pyrite concentrates, and a calcine leaching plant for producing gold from the calcines of the acid plant. Reasons for the complex and its operation are discussed. (DLC)

  17. Effect of Functional Nano Channel Structures Different Widths on Injection Molding and Compression Molding Replication Capabilities

    DEFF Research Database (Denmark)

    Calaon, M.; Tosello, G.; Garnaes, J.

    The present study investigates the capabilities of the two employed processes, injection molding (IM) and injection compression molding (ICM) on replicating different channel cross sections. Statistical design of experiment was adopted to optimize replication quality of produced polymer parts wit...

  18. Porous media heat transfer for injection molding

    Science.gov (United States)

    Beer, Neil Reginald

    2016-05-31

    The cooling of injection molded plastic is targeted. Coolant flows into a porous medium disposed within an injection molding component via a porous medium inlet. The porous medium is thermally coupled to a mold cavity configured to receive injected liquid plastic. The porous medium beneficially allows for an increased rate of heat transfer from the injected liquid plastic to the coolant and provides additional structural support over a hollow cooling well. When the temperature of the injected liquid plastic falls below a solidifying temperature threshold, the molded component is ejected and collected.

  19. Fabrication of silicon molds for polymer optics

    DEFF Research Database (Denmark)

    Nilsson, Daniel; Jensen, Søren; Menon, Aric Kumaran

    2003-01-01

    A silicon mold used for structuring polymer microcavities for optical applications is fabricated, using a combination of DRIE (deep reactive ion etching) and anisotropic chemical wet etching with KOH + IPA. For polymer optical microcavities, low surface roughness and vertical sidewalls are often ...... and KOH + IPA etch have been optimized. To reduce stiction between the silicon mold and the polymers used for molding, the mold is coated with a teflon-like material using the DRIE system. Released polymer microstructures characterized with AFM and SEM are also presented....

  20. Optimization of design and operating parameters in a pilot scale Jameson cell for slime coal cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Hacifazlioglu, Hasan; Toroglu, Ihsan [Department of Mining Engineering, University of Karaelmas, 67100 (Turkey)

    2007-07-15

    The Jameson flotation cell has been commonly used to treat a variety of ores (lead, zinc, copper etc.), coal and industrial minerals at commercial scale since 1989. It is especially known to be highly efficient at fine and ultrafine coal recovery. However, although the Jameson cell has quite a simple structure, it may be largely inefficient if the design and operating parameters chosen are not appropriate. In this study, the design and operating parameters of a pilot scale Jameson cell were optimized to obtain a desired metallurgical performance in the slime coal flotation. The optimized design parameters are the nozzle type, the height of the nozzle above the pulp level, the downcomer diameter and the immersion depth of the downcomer. Among the operating parameters optimized are the collector dosage, the frother dosage, the percentage of solids and the froth height. In the optimum conditions, a clean coal with an ash content of 14.90% was obtained from the sample slime having 45.30% ash with a combustible recovery of 74.20%. In addition, a new type nozzle was developed for the Jameson cell, which led to an increase of about 9% in the combustible recovery value.

  1. Hydrogen silsesquioxane mold coatings for improved replication of nanopatterns by injection molding

    DEFF Research Database (Denmark)

    Hobæk, Thor Christian; Matschuk, Maria; Kafka, Jan

    2015-01-01

    of replication, thus allowing more time to fill the nanoscale cavities compared to standard metal molds. A monolayer of a fluorinated silane (heptadecafluorotrichlorosilane) deposited on the mold surface reduces the mold/polymer interfacial energy to support demolding of the polymer replica. The mechanical...

  2. Anti-plasmodial and insecticidal activities of the essential oils of aromatic plants growing in the Mediterranean area

    Directory of Open Access Journals (Sweden)

    Dell’Agli Mario

    2012-07-01

    Full Text Available Abstract Background Sardinia is a Mediterranean area endemic for malaria up to the last century. During a screening study to evaluate the anti-plasmodial activity of some aromatic plants traditionally used in Sardinia, Myrtus communis (myrtle, Myrtaceae, Satureja thymbra (savory, Lamiaceae, and Thymus herba-barona (caraway thyme, Lamiaceae were collected in three vegetative periods: before, during and after flowering. Methods The essential oils were obtained by steam distillation, fractionated by silica gel column chromatography and analysed by GC-FID-MS. Total oil and three main fractions were tested on D10 and W2 strains of Plasmodium falciparum in vitro. Larvicidal and adulticidal activities were tested on Anopheles gambiae susceptible strains. Results The essential oil of savory, rich in thymol, was the most effective against P. falciparum with an inhibitory activity independent from the time of collection (IC50 17–26 μg/ml on D10 and 9–11 μg/ml on W2. Upon fractionation, fraction 1 was enriched in mono-sesquiterpenoid hydrocarbons; fraction 2 in thymol (73-83%; and fraction 3 contained thymol, carvacrol and terpinen-4-ol, with a different composition depending on the time of collection. Thymol-enriched fractions were the most active on both strains (IC50 20–22 μg/ml on D10 and 8–10 μg/ml on W2 and thymol was confirmed as mainly responsible for this activity (IC50 19.7± 3.0 and 10.6 ± 2.0 μg/ml on D10 and W2, respectively. The essential oil of S. thymbra L. showed also larvicidal and adulticidal activities. The larvicidal activity, expressed as LC50, was 0.15 ± 0.002; 0.21 ± 0.13; and 0.15 ± 0.09 μg/ml (mean ± sd depending on the time of collection: before, during and after flowering, respectively. Conclusions This study provides evidence for the use of essential oils for treating malaria and fighting the vector at both the larval and adult stages. These findings open the possibility for further

  3. Nano-ceramics and its molding technologies

    International Nuclear Information System (INIS)

    Liu Jian; Xu Yunshu

    2007-01-01

    Nano-ceramics and its related knowledge were introduced. Fabrication of nano-ceramic powder, as well as the molding and sintering technologies of nano-ceramics were reviewed. Features of the present molding technologies were analyzed. The applications of nano-ceramics were prospected. (authors)

  4. Digital Twin concept for smart injection molding

    Science.gov (United States)

    Liau, Y.; Lee, H.; Ryu, K.

    2018-03-01

    Injection molding industry has evolved over decades and became the most common method to manufacture plastic parts. Monitoring and improvement in the injection molding industry are usually performed separately in each stage, i.e. mold design, mold making and injection molding process. However, in order to make a breakthrough and survive in the industrial revolution, all the stages in injection molding need to be linked and communicated with each other. Any changes in one stage will cause a certain effect in other stage because there is a correlation between each other. Hence, the simulation should not only based on the input of historical data, but it also needs to include the current condition of equipment and prediction of future events in other stages to make the responsive decision. This can be achieved by implementing the concept of Digital Twin that models the entire process as a virtual model and enables bidirectional control with the physical process. This paper presented types of data and technology required to build the Digital Twin for the injection molding industry. The concept includes Digital Twin of each stage and integration of these Digital Twin model as a thoroughgoing model of the injection molding industry.

  5. Thermal Stress of Surface of Mold Cavities and Parting Line of Silicone Molds

    Directory of Open Access Journals (Sweden)

    Bajčičák Martin

    2014-06-01

    Full Text Available The paper is focused on the study of thermal stress of surface of mold cavities and parting line of silicone molds after pouring. The silicone mold White SD - THT was thermally stressed by pouring of ZnAl4Cu3 zinc alloy with pouring cycle 20, 30 and 40 seconds. The most thermally stressed part of surface at each pouring cycle is gating system and mold cavities. It could be further concluded that linear increase of the pouring cycle time leads to the exponential increasing of the maximum temperature of mold surface after its cooling. The elongated pouring cycle increases the temperature accumulated on the surface of cavities and the ability of silicone mold to conduct the heat on its surface decreases, because the low thermal conductivity of silicone molds enables the conduction of larger amount of heat into ambient environment.

  6. Immune Response among Patients Exposed to Molds

    Directory of Open Access Journals (Sweden)

    Jordan N. Fink

    2009-12-01

    Full Text Available Macrocyclic trichothecenes, mycotoxins produced by Stachybotrys chartarum, have been implicated in adverse reactions in individuals exposed to mold-contaminated environments. Cellular and humoral immune responses and the presence of trichothecenes were evaluated in patients with mold-related health complaints. Patients underwent history, physical examination, skin prick/puncture tests with mold extracts, immunological evaluations and their sera were analyzed for trichothecenes. T-cell proliferation, macrocyclic trichothecenes, and mold specific IgG and IgA levels were not significantly different than controls; however 70% of the patients had positive skin tests to molds. Thus, IgE mediated or other non-immune mechanisms could be the cause of their symptoms.

  7. Computer-aided injection molding system

    Science.gov (United States)

    Wang, K. K.; Shen, S. F.; Cohen, C.; Hieber, C. A.; Isayev, A. I.

    1982-10-01

    Achievements are reported in cavity-filling simulation, modeling viscoelastic effects, measuring and predicting frozen-in birefringence in molded parts, measuring residual stresses and associated mechanical properties of molded parts, and developing an interactive mold-assembly design program and an automatic NC maching data generation and verification program. The Cornell Injection Molding Program (CIMP) consortium is discussed as are computer user manuals that have been published by the consortium. Major tasks which should be addressed in future efforts are listed, including: (1) predict and experimentally determine the post-fillin behavior of thermoplastics; (2) simulate and experimentally investigate the injection molding of thermosets and filled materials; and (3) further investigate residual stresses, orientation and mechanical properties.

  8. Comparing suppository mold variability which can lead to dosage errors for suppositories prepared with the same or different molds.

    Science.gov (United States)

    Alexander, Kenneth S; Baki, Gabriella; Hart, Christine; Hejduk, Courtney; Chillas, Stephanie

    2013-01-01

    Suppository molds must be properly calibrated to ensure accurate dosing. There are often slight differences between molds and even in the cavities within a mold. A method is presented for the calibration of standard aluminum 6-, 12-, 50-, or 100-well suppository molds. Ten different molds were tested using water for volume calibration, and cocoa butter for standardization involving establishing the density factor. This method is shown to be straightforward and appropriate for calibrating suppository molds.

  9. Characterization of Injection Molded Structures

    DEFF Research Database (Denmark)

    Sun, Ling; Søgaard, Emil; Andersen, Nis Korsgaard

    for different applications. We show how to correlate the structures of the polymer replicas with respect to their functionalities. Furthermore, we introduce how we coordinate with all partners in the “Nanoplast” project, and how we utilize the existing facilities of each method to understand structure......Microscopy has been widely applied to understand surface structures of solid samples. According to the instrumental methodology, there are different microscopy methods: optical microscopy, electron microscopy, and scanning probe microscopy (SPM). These microscopy methods have individual advantages...... and limitations. Therefore, it would be difficult to characterize complex, especially hierarchical structures by using only one method. Here we present a combined optical microscopy, scanning electron microscopy (SEM), and scanning probe microscopy study on injection molded structures. These structures are used...

  10. Medical diagnostics for indoor mold exposure.

    Science.gov (United States)

    Hurraß, Julia; Heinzow, Birger; Aurbach, Ute; Bergmann, Karl-Christian; Bufe, Albrecht; Buzina, Walter; Cornely, Oliver A; Engelhart, Steffen; Fischer, Guido; Gabrio, Thomas; Heinz, Werner; Herr, Caroline E W; Kleine-Tebbe, Jörg; Klimek, Ludger; Köberle, Martin; Lichtnecker, Herbert; Lob-Corzilius, Thomas; Merget, Rolf; Mülleneisen, Norbert; Nowak, Dennis; Rabe, Uta; Raulf, Monika; Seidl, Hans Peter; Steiß, Jens-Oliver; Szewszyk, Regine; Thomas, Peter; Valtanen, Kerttu; Wiesmüller, Gerhard A

    2017-04-01

    In April 2016, the German Society of Hygiene, Environmental Medicine and Preventative Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin (GHUP)) together with other scientific medical societies, German and Austrian medical societies, physician unions and experts has provided an AWMF (Association of the Scientific Medical Societies) guideline 'Medical diagnostics for indoor mold exposure'. This guideline shall help physicians to advise and treat patients exposed indoors to mold. Indoor mold growth is a potential health risk, even without a quantitative and/or causal association between the occurrence of individual mold species and health effects. Apart from the allergic bronchopulmonary aspergillosis (ABPA) and the mycoses caused by mold, there is only sufficient evidence for the following associations between moisture/mold damages and different health effects: Allergic respiratory diseases, asthma (manifestation, progression, exacerbation), allergic rhinitis, exogenous allergic alveolitis and respiratory tract infections/bronchitis. In comparison to other environmental allergens, the sensitizing potential of molds is estimated to be low. Recent studies show a prevalence of sensitization of 3-10% in the total population of Europe. The evidence for associations to mucous membrane irritation and atopic eczema (manifestation, progression, exacerbation) is classified as limited or suspected. Inadequate or insufficient evidence for an association is given for COPD, acute idiopathic pulmonary hemorrhage in children, rheumatism/arthritis, sarcoidosis, and cancer. The risk of infections from indoor molds is low for healthy individuals. Only molds that are capable to form toxins can cause intoxications. The environmental and growth conditions and especially the substrate determine whether toxin formation occurs, but indoor air concentrations are always very low. In the case of indoor moisture/mold damages, everyone can be affected by odor effects and

  11. A flow cytometry-based workflow for detection and quantification of anti-plasmodial antibodies in vaccinated and naturally exposed individuals

    DEFF Research Database (Denmark)

    Ajua, Anthony; Engleitner, Thomas; Esen, Meral

    2012-01-01

    information about natural exposure and vaccine immunogenicity. A novel, cytometry-based workflow for the quantitative detection of anti-plasmodial antibodies in human serum is presented. METHODS: Fixed red blood cells (RBCs), infected with late stages of P. falciparum were utilized to detect malaria...... vaccine trials in semiimmune adults and pre-school children residing in a malaria endemic area. RESULTS: Fixation, permeabilization, and staining of infected RBCs were adapted for best operation in flow cytometry. As asexual vaccine candidates are designed to induce antibody patterns similar to semi...... with those obtained by manual gating (r between 0.79 and 0.99) and outperformed other model-driven gating methods. Bland-Altman plots confirmed the agreement of manual gating and OSA derived results. A-1.33 fold increase (p=0.003) in the number of positive cells after vaccination in a subgroup of preschool...

  12. Using of clay-salt slimes of 'Belaruskali' factory as a sorbents of radionuclide

    International Nuclear Information System (INIS)

    Maskalchuk, L.

    2010-01-01

    Document available in extended abstract form only. The effective sorbents for decrease of radionuclide migration in soil and prevention of pollution risk of soil and underground water by radionuclide, according to available practical experience on minimization of consequences of the Chernobyl NPP accident, are: clay minerals of layered structure of type 2:1, potash fertilizers for 137 Cs and potassium rocks for 90 Sr. The analysis of literary data shows, those there two base kinds of industrial waste are formed at sylvinite ore processing almost at all potassium plants of the world: - Solid halite rejects material - Liquid waste in the form of clay-salt slimes. There is about 9 % of halite waste from annual formation using in Belarus, clay-salt slimes (CSS) are not used in general and all the volume goes to slime storage. Clay-salt slimes are the waste products of potassium production being formed in the course of sylvinite ore conversion at processing plants of the Industrial centre 'Belaruskali'. Up to the present moment about 80 millions of tones of clay-salt slimes have been accumulated in Soligorsk industrial zone, and their annual formation makes up about 2.0-2.5 millions of tones. The volume of industrial waste collected in Republic of Belarus allows considering CSS as a possible source of low-cost raw material for reception of products with different functions. On the other hand by estimation of national and international experts such quantity of industrial waste, especially liquid, represents ecological danger. Taking into account this circumstance the situation with industrial waste disposal in Soligorsk industrial area of Belarus which was estimated by international experts as critical one and it needs the cardinal measures for further environment pollution prevention. There is considerable volume of liquid radioactive waste is formed at the Nuclear Power Plant operation. Modern tendencies of radioactive waste disposal are directed on

  13. Laboratory evaluation of different formulations of Stress Coat® for slime production in goldfish (Carassius auratus) and koi (Cyprinus carpio).

    Science.gov (United States)

    Shivappa, Raghunath B; Christian, Larry S; Law, Jerry M; Lewbart, Gregory A

    2017-01-01

    A study was carried out to assess the effect of Stress Coat ® on slime production in goldfish ( Carassius auratus) and koi ( Cyprinus carpio ). The study also investigated histological changes that might be associated with slime producing cells, and wound healing in koi. Several formulations of Stress Coat ® were investigated and the results showed that polyvinylpyrrolidone (PVP), also known as povidone, an ingredient of Stress Coat ® , when used alone, showed significantly higher slime production in goldfish than salt and Stress Coat ® without PVP after 25 h. The results also showed that koi treated with compounds containing PVP showed better wound healing than those not exposed to PVP. Histology results showed no difference between compounds tested with regards to density and number of slime producing cells.

  14. Laboratory evaluation of different formulations of Stress Coat® for slime production in goldfish (Carassius auratus and koi (Cyprinus carpio

    Directory of Open Access Journals (Sweden)

    Raghunath B. Shivappa

    2017-09-01

    Full Text Available A study was carried out to assess the effect of Stress Coat® on slime production in goldfish (Carassius auratus and koi (Cyprinus carpio. The study also investigated histological changes that might be associated with slime producing cells, and wound healing in koi. Several formulations of Stress Coat® were investigated and the results showed that polyvinylpyrrolidone (PVP, also known as povidone, an ingredient of Stress Coat®, when used alone, showed significantly higher slime production in goldfish than salt and Stress Coat® without PVP after 25 h. The results also showed that koi treated with compounds containing PVP showed better wound healing than those not exposed to PVP. Histology results showed no difference between compounds tested with regards to density and number of slime producing cells.

  15. Multi-element sewer slime impact pattern - a quantitative characteristic enabling identification of the source of heavy metal discharges into sewer systems

    Energy Technology Data Exchange (ETDEWEB)

    Kintrup, J. [Chemistry Lab., Wessling GmbH, Hannover (Germany); Wuensch, G. [Lehrgebiet Analytische Chemie, Univ. Hannover (Germany)

    2001-11-01

    The capability of sewer slime to accumulate heavy metals from municipal wastewater can be exploited to identify the sources of sewage sludge pollution. Former investigations of sewer slime looked for a few elements only and could, therefore, not account for deviations of the enrichment efficiency of the slime or for irregularities from sampling. Results of ICP-MS multi element determinations were analyzed by multivariate statistical methods. A new dimensionless characteristic ''sewer slime impact'' is proposed, which is zero for unloaded samples. Patterns expressed in this data format specifically extract the information required to identify the type of pollution and polluter quicker and with less effort and cost than hitherto. (orig.)

  16. Molded ultra-low density microcellular foams

    International Nuclear Information System (INIS)

    Rand, P.B.; Montoya, O.J.

    1986-07-01

    Ultra-low density (< 0.01 g/cc) microcellular foams were required for the NARYA pulsed-power-driven x-ray laser development program. Because of their extreme fragility, molded pieces would be necessary to successfully field these foams in the pulsed power accelerator. All of the foams evaluated were made by the thermally induced phase separation technique from solutions of water soluble polymers. The process involved rapidly freezing the solution to induce the phase separation, and then freeze drying to remove the water without destroying the foam's structure. More than sixty water soluble polymers were evaluated by attempting to make their solutions into foams. The foams were evaluated for shrinkage, density, and microstructure to determine their suitability for molding and meeting the required density and cell size requirements of 5.0 mg/cc and less than twenty μmeters. Several promising water soluble polymers were identified including the polyactylic acids, guar gums, polyactylamide, and polyethylene oxide. Because of thier purity, structure, and low shrinkage, the polyacrylic acids were chosen to develop molding processes. The initial requirements were for 2.0 cm. long molded rods with diameters of 1.0, 2.0. and 3.0 mm. These rods were made by freezing the solution in thin walled silicon rubber molds, extracting the frozen preform from the mold, and then freeze drying. Requirements for half rods and half annuli necessitated using aluminum molds. Again we successfully molded these shapes. Our best efforts to date involve molding annuli with 3.0 mm outside diameters and 2.0 mm inside diameters

  17. Mold contamination of automobile air conditioner systems.

    Science.gov (United States)

    Kumar, P; Lopez, M; Fan, W; Cambre, K; Elston, R C

    1990-02-01

    Eight cars belonging to patients who were found to have exacerbation of allergic rhinitis and bronchial asthma after turning on the air conditioner in their cars were examined. Mold concentrations inside the passenger compartment with the a/c turned off and at different climate control settings were lower than concentrations in the outside air. After turning on the air conditioner to "Max", cultures obtained at various intervals revealed that mold concentrations decreased significantly with time. Furthermore, placement of a filter at the portal of entry of outside air significantly reduced the mold concentration in the passenger compartment.

  18. Fast prototyping of injection molded polymer microfluidic chips

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Selmeczi, David; Larsen, Niels Bent

    2010-01-01

    We present fast prototyping of injection molding tools by the definition of microfluidic structures in a light-curable epoxy (SU-8) directly on planar nickel mold inserts. Optimized prototype mold structures could withstand injection molding of more than 300 replicas in cyclic olefin copolymer (COC...

  19. Ultrasound - Aided ejection in micro injection molding

    Science.gov (United States)

    Masato, D.; Sorgato, M.; Lucchetta, G.

    2018-05-01

    In this work, an ultrasound-aided ejection system was designed and tested for different polymers (PS, COC and POM) and mold topographies. The proposed solution aims at reducing the ejection friction by decreasing the adhesion component of the frictional force, which is controlled by the contact area developed during the filling stage of the injection molding process. The experimental results indicate a positive effect of ultrasound vibration on the friction force values, with a maximum reduction of 16. Moreover, it is demonstrated that the ultrasound effect is strictly related to both polymer selection and mold roughness. The combined effect on the ejection force of mold surface roughness, melt viscosity during filling and polymer elastic modulus at ejection was modeled to the experimental data, in order to demonstrate that the effect of ultrasound vibration on the ejection friction reduction is due to the heating of the contact interface and the consequent reduction of the polymer elastic modulus.

  20. National Allergy Bureau Pollen and Mold Report

    Science.gov (United States)

    ... Search AAAAI National Allergy Bureau Pollen and Mold Report Date: May 19, 2018 Location: San Antonio (2), ... 18/2018 ( click here to view ). Our Allergen Report Email Service can automatically email you daily pollen ...

  1. MATERIALS FOR PRODUCTION OF METAL MOLDS

    Directory of Open Access Journals (Sweden)

    A. Ju. Jakovlev

    2007-01-01

    Full Text Available The influence of alloying with manganese, chromium, nickel, copper and molybdenum on mechanical characteristics and thermocyclic endurance of grayed steel and possibility of its application for metal casting molds is investigated.

  2. Molds on Food: Are They Dangerous?

    Science.gov (United States)

    ... refrigerator every few months with 1 tablespoon of baking soda dissolved in a quart of water. Rinse ... Francisco, Italian, and Eastern European types — have a characteristic thin, white mold coating which is safe to ...

  3. Surface microstructure replication in injection molding

    DEFF Research Database (Denmark)

    Theilade, Uffe Arlø; Hansen, Hans Nørgaard

    2006-01-01

    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...... molding of surface microstructures. The fundamental problem of surface microstructure replication has been studied. The research is based on specific microstructures as found in lab-on-a-chip products and on rough surfaces generated from EDM (electro discharge machining) mold cavities. Emphasis is put...... on the ability to replicate surface microstructures under normal injection-molding conditions, i.e., with commodity materials within typical process windows. It was found that within typical process windows the replication quality depends significantly on several process parameters, and especially the mold...

  4. Antimicrobial Treatments of Indoor Mold and Bacteria

    Science.gov (United States)

    Biological contaminants especially mold in buildings are known to act as sources of indoor air pollution, discomfort, asthma and pulmonary disease to building occupants. Sick buildings are evidence of extremely problematic indoor air quality (IAQ), often resulting from unacceptab...

  5. Additive Manufacturing of Wind Turbine Molds

    Energy Technology Data Exchange (ETDEWEB)

    Post, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Richardson, Bradley [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lloyd, Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Love, Lonnie [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nolet, Stephen [TPI Composites, Scottsdale, AZ (United States); Hannan, James [TPI Composites, Scottsdale, AZ (United States)

    2017-07-01

    The objective of this project was to explore the utility of Big Area Additive Manufacturing (BAAM) for low cost manufacturing of wind turbine molds. Engineers at Oak Ridge National Laboratory (ORNL) and TPI Composites (TPI) collaborated to design and manufacture a printed mold that can be used for resin infusion of wind turbine components. Specific focus was on required material properties (operating temperatures and pressures, coefficient of thermal expansion (CTE), thermal conductivity), surface finish (accuracy and coatings) and system integration (integrated vacuum ports, and heating element). The project began with a simple proof of principle components, targeting surface coatings and material properties for printing a small section (approximately 4’ x 4’ x 2’) of a mold. Next, the second phase scaled up and integrated with the objective of capturing all of the necessary components (integrated heating to accelerate cure time, and vacuum, sealing) for resin infusion on a mold of significant size (8’ x 20’ x 6’).

  6. Molding apparatus. [for thermosetting plastic compositions

    Science.gov (United States)

    Heier, W. C. (Inventor)

    1974-01-01

    Apparatus for compression molding of thermosetting plastics compositions including interfitting hollow male and female components is reported. The components are adapted to be compressed to form a rocket nozzle in a cavity. A thermal jacket is provided exteriorly adjacent to the female component for circulating a thermal transfer fluid to effect curing of a thermosetting plastics material being molded. Each of the male and female components is provided with suitable inlets and outlets for circulating a thermal transfer fluid.

  7. Effect of a pesticide on the extracellular slime production and pathogenicity of a non-target phytopathogen

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, A [Tamil Nadu Agricultural Univ., Coimbatore (India); Nilakantan, Gita [University of Agricultural Sciences, Bangalore (India)

    1978-12-01

    Aldicarb (2 methyl thio) propionaldehyde-0-(methyl carbamoyl oxime), a systemic insecticide treatment altered the quantity and the quality of the extracellular polysaccharides (slime) produced by Pseudomonas solanacearum. Although 5 ppm (normal dose) aldicarb treatment reduced the quality of polysaccharides produced by the cells, the incorporation of /sup 14/C (glucose) label and the reducing sugar contents was higher than the other treatments. Chromatographic analysis of the hydrolysed polysaccharides showed that aldicarb treatment altered their qualitative composition also. The extracellular polysaccharides produced by the pathogen treated with 5 ppm aldicarb caused wilting of tomato seedlings earlier than others, indicating thereby, that the wilt inducing factor in the slime was altered by the pesticide treatment. The limited translocation of the /sup 14/C labelled polysaccharides in the wilted seedlings indicated mechanical blocking of the vascular system of the plants.

  8. Effect of a pesticide on the extracellular slime production and pathogenicity of a non-target phytopathogen

    International Nuclear Information System (INIS)

    Balasubramanian, A.; Nilakantan, Gita

    1978-01-01

    Aldicarb (2 methyl thio) propionaldehyde-0-(methyl carbamoyl oxime), a systemic insecticide treatment altered the quantity and the quality of the extracellular polysaccharides (slime) produced by Pseudomonas solanacearum. Although 5 ppm (normal dose) aldicarb treatment reduced the quality of polysaccharides produced by the cells, the incorporation of 14 C (glucose) label and the reducing sugar contents was higher than the other treatments. Chromatographic analysis of the hydrolysed polysaccharides showed that aldicarb treatment altered their qualitative composition also. The extracellular polysaccharides produced by the pathogen treated with 5 ppm aldicarb caused wilting of tomato seedlings earlier than others, indicating thereby, that the wilt inducing factor in the slime was altered by the pesticide treatment. The limited translocation of the 14 C labelled polysaccharides in the wilted seedlings indicated mechanical blocking of the vascular system of the plants. (author)

  9. Traditional Mold Analysis Compared to a DNA-based Method of Mold Analysis with Applications in Asthmatics' Homes

    Science.gov (United States)

    Traditional environmental mold analysis is based-on microscopic observations and counting of mold structures collected from the air on a sticky surface or culturing of molds on growth media for identification and quantification. A DNA-based method of mold analysis called mol...

  10. Factors influencing microinjection molding replication quality

    Science.gov (United States)

    Vera, Julie; Brulez, Anne-Catherine; Contraires, Elise; Larochette, Mathieu; Trannoy-Orban, Nathalie; Pignon, Maxime; Mauclair, Cyril; Valette, Stéphane; Benayoun, Stéphane

    2018-01-01

    In recent years, there has been increased interest in producing and providing high-precision plastic parts that can be manufactured by microinjection molding: gears, pumps, optical grating elements, and so on. For all of these applications, the replication quality is essential. This study has two goals: (1) fabrication of high-precision parts using the conventional injection molding machine; (2) identification of robust parameters that ensure production quality. Thus, different technological solutions have been used: cavity vacuuming and the use of a mold coated with DLC or CrN deposits. AFM and SEM analyses were carried out to characterize the replication profile. The replication quality was studied in terms of the process parameters, coated and uncoated molds and crystallinity of the polymer. Specific studies were processed to quantify the replicability of injection molded parts (ABS, PC and PP). Analysis of the Taguchi experimental designs permits prioritization of the impact of each parameter on the replication quality. A discussion taking into account these new parameters and the thermal and spreading properties on the coatings is proposed. It appeared that, in general, increasing the mold temperature improves the molten polymer fill in submicron features except for the steel insert (for which the presence of a vacuum is the most important factor). Moreover, the DLC coating was the best coating to increase the quality of the replication. This result could be explained by the lower thermal diffusivity of this coating. We noted that the viscosity of the polymers is not a primordial factor of the replication quality.

  11. Die Casting Mold Design for Aluminum Alloy Shell of Instrument

    Directory of Open Access Journals (Sweden)

    Li Yuanyuan

    2015-01-01

    Full Text Available This paper is about die casting mold design for aluminum alloy shell of instrument. Three-dimensional model of the casting and mold are designed by using Pro/Engineer and AutoCad which can analyze forming quality. Digital design and theoretical calculation can greatly shorten product development cycle and mold design cycle, improve the accuracy of product design and mold design, and reduce the cost of mold design.

  12. Effects of fast mold temperature evolution on micro features replication quality during injection molding

    DEFF Research Database (Denmark)

    Liparoti, S.; Calaon, M.; Speranza, V.

    2017-01-01

    lithography and subsequent nickel electroplating. The mold temperature was controlled by a thin heating device (composed by polyimide as insulating layer and polyimide carbon black loaded as electrical conductive layer) able to increase the temperature on mold surface in a few seconds (40°C/s) by Joule...

  13. Fast Mold Temperature Evolution on Micro Features Replication Quality during Injection Molding

    DEFF Research Database (Denmark)

    Liparoti, S.; Calaon, Matteo; Speranza, V.

    2016-01-01

    lithography and subsequent nickel electroplating. The mold temperature was controlled by a thin heating device (composed by polyimide as insulating layer and polyimide carbon black loaded aselectrical conductive layer) able to increase the temperature on mold surface in a few seconds (40°C/s) by Joule effect...

  14. Effects of mold geometry on fiber orientation of powder injection molded metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Faiz, E-mail: faizahmad@petronas.com.my; Aslam, Muhammad, E-mail: klaira73@gmail.com; Altaf, Khurram, E-mail: khurram.altaf@petronas.com.my; Shirazi, Irfan, E-mail: irfanshirazi@hotmail.com [Mechanical Engineering Universiti Teknologi PETRONAS Malaysia (Malaysia)

    2015-07-22

    Fiber orientations in metal matrix composites have significant effect on improving tensile properties. Control of fiber orientations in metal injection molded metal composites is a difficult task. In this study, two mold cavities of dimensions 6x6x90 mm and 10x20x180 mm were used for comparison of fiber orientation in injection molded metal composites test parts. In both mold cavities, convergent and divergent flows were developed by modifying the sprue dimensions. Scanning electron microscope (SEM) was used to examine the fiber orientations within the test samples. The results showed highly aligned fiber in injection molded test bars developed from the convergent melt flow. Random orientation of fibers was noted in the composites test bars produced from divergent melt flow.

  15. Creating mold-free buildings: a key to avoiding health effects of indoor molds.

    Science.gov (United States)

    Small, Bruce M

    2003-08-01

    In view of the high costs of building diagnostics and repair subsequent to water damage--as well as the large medical diagnostic and healthcare costs associated with mold growth in buildings--commitment to a philosophy of proactive preventive maintenance for home, apartment, school, and commercial buildings could result in considerable cost savings and avoidance of major health problems among building occupants. The author identifies common causes of mold growth in buildings and summarizes key building design and construction principles essential for preventing mold contamination indoors. Physicians and healthcare workers must be made aware of conditions within buildings that can give rise to mold growth, and of resulting health problems. Timely advice provided to patients already sensitized by exposure to molds could save these individuals, and their families, from further exposures as a result of inadequate building maintenance or an inappropriate choice of replacement housing.

  16. Injection molding of high aspect ratio sub-100 nm nanostructures

    DEFF Research Database (Denmark)

    Matschuk, Maria; Larsen, Niels B

    2013-01-01

    We have explored the use of mold coatings and optimized processing conditions to injection mold high aspect ratio nanostructures (height-to-width >1) in cyclic olefin copolymer (COC). Optimizing the molding parameters on uncoated nickel molds resulted in slight improvements in replication quality...... as described by height, width and uniformity of the nanoscopic features. Use of a mold temperature transiently above the polymer glass transition temperature (Tg) was the most important factor in increasing the replication fidelity. Surface coating of the nickel molds with a fluorocarbon-containing thin film...... (FDTS) greatly enhanced the quality of replicated features, in particular at transient mold temperatures above Tg. Injection molding using the latter mold temperature regime resulted in a bimodal distribution of pillar heights, corresponding to either full or very poor replication of the individual...

  17. Nanostructuring steel for injection molding tools

    International Nuclear Information System (INIS)

    Al-Azawi, A; Smistrup, K; Kristensen, A

    2014-01-01

    The production of nanostructured plastic items by injection molding with ridges down to 400 nm in width, which is the smallest line width replicated from nanostructured steel shims, is presented. Here we detail a micro-fabrication method where electron beam lithography, nano-imprint lithography and ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro- and nanostructuring the surface of the steel molds. We investigate the minimum line width that can be realized by our fabrication method and the influence of etching angle on the structure profile during the ion beam etching process. Trenches down to 400 nm in width have been successfully fabricated into a 316 type electro-polished steel wafer. Afterward a plastic replica has been produced by injection molding with good structure transfer fidelity. Thus we have demonstrated that by utilizing well-established fabrication techniques, nanostructured steel shims that are used in injection molding, a technique that allows low cost mass fabrication of plastic items, are produced. (paper)

  18. In vitro anti-plasmodial activity of Dicoma anomala subsp. gerrardii (Asteraceae): identification of its main active constituent, structure-activity relationship studies and gene expression profiling.

    Science.gov (United States)

    Becker, John V W; van der Merwe, Marina M; van Brummelen, Anna C; Pillay, Pamisha; Crampton, Bridget G; Mmutlane, Edwin M; Parkinson, Chris; van Heerden, Fanie R; Crouch, Neil R; Smith, Peter J; Mancama, Dalu T; Maharaj, Vinesh J

    2011-10-11

    Anti-malarial drug resistance threatens to undermine efforts to eliminate this deadly disease. The resulting omnipresent requirement for drugs with novel modes of action prompted a national consortium initiative to discover new anti-plasmodial agents from South African medicinal plants. One of the plants selected for investigation was Dicoma anomala subsp. gerrardii, based on its ethnomedicinal profile. Standard phytochemical analysis techniques, including solvent-solvent extraction, thin-layer- and column chromatography, were used to isolate the main active constituent of Dicoma anomala subsp. gerrardii. The crystallized pure compound was identified using nuclear magnetic resonance spectroscopy, mass spectrometry and X-ray crystallography. The compound was tested in vitro on Plasmodium falciparum cultures using the parasite lactate dehydrogenase (pLDH) assay and was found to have anti-malarial activity. To determine the functional groups responsible for the activity, a small collection of synthetic analogues was generated - the aim being to vary features proposed as likely to be related to the anti-malarial activity and to quantify the effect of the modifications in vitro using the pLDH assay. The effects of the pure compound on the P. falciparum transcriptome were subsequently investigated by treating ring-stage parasites (alongside untreated controls), followed by oligonucleotide microarray- and data analysis. The main active constituent was identified as dehydrobrachylaenolide, a eudesmanolide-type sesquiterpene lactone. The compound demonstrated an in vitro IC50 of 1.865 μM against a chloroquine-sensitive strain (D10) of P. falciparum. Synthetic analogues of the compound confirmed an absolute requirement that the α-methylene lactone be present in the eudesmanolide before significant anti-malarial activity was observed. This feature is absent in the artemisinins and suggests a different mode of action. Microarray data analysis identified 572 unique genes that

  19. In vitro anti-plasmodial activity of Dicoma anomala subsp. gerrardii (Asteraceae: identification of its main active constituent, structure-activity relationship studies and gene expression profiling

    Directory of Open Access Journals (Sweden)

    van Heerden Fanie R

    2011-10-01

    Full Text Available Abstract Background Anti-malarial drug resistance threatens to undermine efforts to eliminate this deadly disease. The resulting omnipresent requirement for drugs with novel modes of action prompted a national consortium initiative to discover new anti-plasmodial agents from South African medicinal plants. One of the plants selected for investigation was Dicoma anomala subsp. gerrardii, based on its ethnomedicinal profile. Methods Standard phytochemical analysis techniques, including solvent-solvent extraction, thin-layer- and column chromatography, were used to isolate the main active constituent of Dicoma anomala subsp. gerrardii. The crystallized pure compound was identified using nuclear magnetic resonance spectroscopy, mass spectrometry and X-ray crystallography. The compound was tested in vitro on Plasmodium falciparum cultures using the parasite lactate dehydrogenase (pLDH assay and was found to have anti-malarial activity. To determine the functional groups responsible for the activity, a small collection of synthetic analogues was generated - the aim being to vary features proposed as likely to be related to the anti-malarial activity and to quantify the effect of the modifications in vitro using the pLDH assay. The effects of the pure compound on the P. falciparum transcriptome were subsequently investigated by treating ring-stage parasites (alongside untreated controls, followed by oligonucleotide microarray- and data analysis. Results The main active constituent was identified as dehydrobrachylaenolide, a eudesmanolide-type sesquiterpene lactone. The compound demonstrated an in vitro IC50 of 1.865 μM against a chloroquine-sensitive strain (D10 of P. falciparum. Synthetic analogues of the compound confirmed an absolute requirement that the α-methylene lactone be present in the eudesmanolide before significant anti-malarial activity was observed. This feature is absent in the artemisinins and suggests a different mode of action

  20. Slime moulds use heuristics based on within-patch experience to decide when to leave.

    Science.gov (United States)

    Latty, Tanya; Beekman, Madeleine

    2015-04-15

    Animals foraging in patchy, non-renewing or slowly renewing environments must make decisions about how long to remain within a patch. Organisms can use heuristics ('rules of thumb') based on available information to decide when to leave the patch. Here, we investigated proximate patch-departure heuristics in two species of giant, brainless amoeba: the slime moulds Didymium bahiense and Physarum polycephalum. We explicitly tested the importance of information obtained through experience by eliminating chemosensory cues of patch quality. In P. polycephalum, patch departure was influenced by the consumption of high, and to a much lesser extent low, quality food items such that engulfing a food item increased patch-residency time. Physarum polycephalum also tended to forage for longer in darkened, 'safe' patches. In D. bahiense, engulfment of any food item increased patch residency irrespective of that food item's quality. Exposure to light had no effect on the patch-residency time of D. bahiense. Given that these organisms lack a brain, our results illustrate how the use of simple heuristics can give the impression that individuals make sophisticated foraging decisions. © 2015. Published by The Company of Biologists Ltd.

  1. Effects of Fermented Sumach on the Formation of Slime Layer of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Sahra Kırmusaoğlu

    2012-03-01

    Full Text Available Objective: Staphylococcus aureus (S. aureus is one of the most commonly isolated bacterial pathogens in hospitals, and the most frequent cause of nosocomial infections. Nosocomial staphylococcal foreign-body infections related to biofilm formation are a serious threat, demanding new therapeutic and preventive strategies. Implantation of intravenous catheters and surgical implantation of prosthetic implants carry a risk of infection. In order to prevent all these effects of biofilms, a study was designed to observe the possible antibacterial effect of sumach (Rhus coriaria on the biofilm formation of S. aureus. Material and Methods: The influence of varying concentrations of sumach on the formation of biofilms by 13 strains of Staphylococcus aureus was tested by a microelisa assay. Results: The significant differences between varying concentrations of sumach (0.1, 0.2, 0.5 and 1.0 µl/ml were observed in four methicillin resistant Staphylococcus aureus (MRSA and nine methicillin sensitive Staphylococcus aureus (MSSA (p<0.05. In bacteria, a dose-related decrease in the formation of slime, which is a major virulence factor of staphylococcal infections, was observed. Conclusion: In our study, using 0.1, 0.2, 0.5 and 1.0 µl/ml of sumach, thirteen strains lost, 17%, 22%, 28% and 48% respectively of their capacity to produce biofilms. Sumach, which is a herbal product, can decrease the formation of biofilm, which is a major virulence factor in staphylococcal infections.

  2. True-slime-mould-inspired hydrostatically coupled oscillator system exhibiting versatile behaviours

    International Nuclear Information System (INIS)

    Umedachi, Takuya; Ito, Kentaro; Idei, Ryo; Ishiguro, Akio

    2013-01-01

    Behavioural diversity is an indispensable attribute of living systems, which makes them intrinsically adaptive and responsive to the demands of a dynamically changing environment. In contrast, conventional engineering approaches struggle to suppress behavioural diversity in artificial systems to reach optimal performance in given environments for desired tasks. The goals of this research include understanding the essential mechanism that endows living systems with behavioural diversity and implementing the mechanism in robots to exhibit adaptive behaviours. For this purpose, we have focused on an amoeba-like unicellular organism: the plasmodium of true slime mould. Despite the absence of a central nervous system, the plasmodium exhibits versatile spatiotemporal oscillatory patterns and switches spontaneously among these patterns. By exploiting this behavioural diversity, it is able to exhibit adaptive behaviour according to the situation encountered. Inspired by this organism, we built a real physical robot using hydrostatically coupled oscillators that produce versatile oscillatory patterns and spontaneous transitions among the patterns. The experimental results show that exploiting physical hydrostatic interplay—the physical dynamics of the robot—allows simple phase oscillators to promote versatile behaviours. The results can contribute to an understanding of how a living system generates versatile and adaptive behaviours with physical interplays among body parts. (paper)

  3. Double blind placebo controlled exposure to molds

    DEFF Research Database (Denmark)

    Meyer, H W; Jensen, K A; Nielsen, K F

    2005-01-01

    non-significant, and at the same level as after placebo exposure. The developed exposure system based on the Particle-Field and Laboratory Emission Cell (P-FLEC) makes it possible to deliver a precise and highly controlled dose of mold spores from water-damaged building materials, imitating realistic......The objective was to develop an experimental setup for human exposure to mold spores, and to study the clinical effect of this exposure in sensitive subjects who had previously experienced potentially building-related symptoms (BRS) at work. From three water-damaged schools eight employees....... In conclusion this is, to our knowledge, the first study to successfully conduct a human exposure to a highly controlled dose of fungal material aerosolized directly from wet building materials. This short-term exposure to high concentrations of two different molds induced no more reactions than exposure...

  4. Nanostructuring steel for injection molding tools

    DEFF Research Database (Denmark)

    Al-Azawi, A.; Smistrup, Kristian; Kristensen, Anders

    2014-01-01

    The production of nanostructured plastic items by injection molding with ridges down to 400 nm in width, which is the smallest line width replicated from nanostructured steel shims, is presented. Here we detail a micro-fabrication method where electron beam lithography, nano-imprint lithography...... and ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro-and nanostructuring the surface of the steel molds. We investigate...... the minimum line width that can be realized by our fabrication method and the influence of etching angle on the structure profile during the ion beam etching process. Trenches down to 400 nm in width have been successfully fabricated into a 316 type electro-polished steel wafer. Afterward a plastic replica...

  5. Injection molded self-cleaning surfaces

    DEFF Research Database (Denmark)

    Søgaard, Emil

    that are superhydrophobic based on topography rather than chemical compounds. Therefore, a novel method for fabricating superhydrophobic polymer surfaces with excellent water-repellant properties is developed. The method is based on microstructure fabrication and superposed nanostructures on silicon wafers. The nano......- and microstructured silicon is electroplated with nickel and the resulting nickel shim with inverse polarity is used in an injection molding process. A versatile injection molding process capable of producing different nano- and microstructures on areas larger than 10 cm2 is developed. Variotherm mold heating is used...... hierarchical structures with nanograss and holes. Water wetting tests are carried out using a pressure cell to control the water pressure. Microscopic wetting behavior of the structures is studied by optical transmission microscopy. Interestingly, it is found that the surface chemistry of the polymer changes...

  6. Effecting aging time of epoxy molding compound to molding process for integrated circuit packaging

    Science.gov (United States)

    Tachapitunsuk, Jirayu; Ugsornrat, Kessararat; Srisuwitthanon, Warayoot; Thonglor, Panakamon

    2017-09-01

    This research studied about effecting aging time of epoxy molding compound (EMC) that effect to reliability performance of integrated circuit (IC) package in molding process. Molding process is so important of IC packaging process for protecting IC chip (or die) from temperature and humidity environment using encapsulated EMC. For general molding process, EMC are stored in the frozen at 5°C and left at room temperature at 25 °C for aging time on self before molding of die onto lead frame is 24 hours. The aging time effect to reliability performance of IC package due to different temperature and humidity inside the package. In experiment, aging time of EMC were varied from 0 to 24 hours for molding process of SOIC-8L packages. For analysis, these packages were tested by x-ray and scanning acoustic microscope to analyze properties of EMC with an aging time and also analyzed delamination, internal void, and wire sweep inside the packages with different aging time. The results revealed that different aging time of EMC effect to properties and reliability performance of molding process.

  7. Experimental Studies of the Effects of Anode Composition and Process Parameters on Anode Slime Adhesion and Cathode Copper Purity by Performing Copper Electrorefining in a Pilot-Scale Cell

    Science.gov (United States)

    Zeng, Weizhi; Wang, Shijie; Free, Michael L.

    2016-10-01

    Copper electrorefining tests were conducted in a pilot-scale cell under commercial tankhouse environment to study the effects of anode compositions, current density, cathode blank width, and flow rate on anode slime behavior and cathode copper purity. Three different types of anodes (high, mid, and low impurity levels) were used in the tests and were analyzed under SEM/EDS. The harvested copper cathodes were weighed and analyzed for impurities concentrations using DC Arc. The adhered slimes and released slimes were collected, weighed, and analyzed for compositions using ICP. It was shown that the lead-to-arsenic ratio in the anodes affects the sintering and coalescence of slime particles. High current density condition can improve anode slime adhesion and cathode purity by intensifying slime particles' coalescence and dissolving part of the particles. Wide cathode blanks can raise the anodic current densities significantly and result in massive release of large slime particle aggregates, which are not likely to contaminate the cathode copper. Low flow rate can cause anode passivation and increase local temperatures in front of the anode, which leads to very intense sintering and coalescence of slime particles. The results and analyses of the tests present potential solutions for industrial copper electrorefining process.

  8. Tool steel quality and surface finishing of plastic molds

    Directory of Open Access Journals (Sweden)

    Rafael Agnelli Mesquita

    2010-01-01

    Full Text Available Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions - machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness. The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

  9. Validation of three-dimensional micro injection molding simulation accuracy

    DEFF Research Database (Denmark)

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

    2011-01-01

    length, injection pressure profile, molding mass and flow pattern. The importance of calibrated micro molding process monitoring for an accurate implementation strategy of the simulation and its validation has been demonstrated. In fact, inconsistencies and uncertainties in the experimental data must...... be minimized to avoid introducing uncertainties in the simulation calculations. Simulations of bulky sub-100 milligrams micro molded parts have been validated and a methodology for accurate micro molding simulations was established....

  10. COMPUTER AIDED THREE DIMENSIONAL DESIGN OF MOLD COMPONENTS

    Directory of Open Access Journals (Sweden)

    Kerim ÇETİNKAYA

    2000-02-01

    Full Text Available Sheet metal molding design with classical methods is formed in very long times calculates and drafts. At the molding design, selection and drafting of most of the components requires very long time because of similar repetative processes. In this study, a molding design program has been developed by using AutoLISP which has been adapted AutoCAD packet program. With this study, design of sheet metal molding, dimensioning, assemly drafting has been realized.

  11. Solvent-assisted polymer micro-molding

    Institute of Scientific and Technical Information of China (English)

    HAN LuLu; ZHOU Jing; GONG Xiao; GAO ChangYou

    2009-01-01

    The micro-molding technology has played an important role in fabrication of polymer micro-patterns and development of functional devices.In such a process,suitable solvent can swell or dissolve the polymer films to decrease their glass transition temperature (Tg) and viscosity and thereby improve flowing ability.Consequently,it is easy to obtain the 2D and 3D patterns with high fidelity by the solvent-assisted micro-molding.Compared with the high temperature molding,this technology overcomes some shortcomings such as shrinking after cooling,degradation at high temperature,difficulty in processing some functional materials having high Tg,etc.It can be applied to making patterns not only on polymer monolayers but also on polyelectrolyte multilayers.Moreover,the compressioninduced patterns on the multilayers are chemically homogenous but physically heterogeneous.In this review,the controlling factors on the pattern quality are also discussed,including materials of the mold,solvent,pressure,temperature and pattern density.

  12. Progress in Titanium Metal Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Randall M. German

    2013-08-01

    Full Text Available Metal powder injection molding is a shaping technology that has achieved solid scientific underpinnings. It is from this science base that recent progress has occurred in titanium powder injection molding. Much of the progress awaited development of the required particles with specific characteristics of particle size, particle shape, and purity. The production of titanium components by injection molding is stabilized by a good understanding of how each process variable impacts density and impurity level. As summarized here, recent research has isolated the four critical success factors in titanium metal powder injection molding (Ti-MIM that must be simultaneously satisfied—density, purity, alloying, and microstructure. The critical role of density and impurities, and the inability to remove impurities with sintering, compels attention to starting Ti-MIM with high quality alloy powders. This article addresses the four critical success factors to rationalize Ti-MIM processing conditions to the requirements for demanding applications in aerospace and medical fields. Based on extensive research, a baseline process is identified and reported here with attention to linking mechanical properties to the four critical success factors.

  13. Molding cork sheets to complex shapes

    Science.gov (United States)

    Sharpe, M. H.; Simpson, W. G.; Walker, H. M.

    1977-01-01

    Partially cured cork sheet is easily formed to complex shapes and then final-cured. Temperature and pressure levels required for process depend upon resin system used and final density and strength desired. Sheet can be bonded to surface during final cure, or can be first-formed in mold and bonded to surface in separate step.

  14. A REVOLUTION IN MOLD IDENTIFICATION AND ENUMERATION

    Science.gov (United States)

    More than 100 assay were developed to identify and quantify indoor molds using quantitiative PCR (QPCR) assays. This technology incorporates fluorigenic 5' nuclease (TaqMan�) chemistry directed at the nuclear ribosomal RNA operon internal transcribed spacer regions (ITS1 or ITS2...

  15. ASSESSMENT OF RELIABILITY AND RISK DEGREE FOR ACCIDENT INITIATION AT SLIME STORAGES OF 4th MINING ADMINISTRATION, JSC “BELARUSKALI”

    Directory of Open Access Journals (Sweden)

    P. M. Bohaslauchyk

    2016-01-01

    Full Text Available Definition of reliability for dams of slime storage embankment is given on the basis of reliability theory and characteristics of reliability and their analysis are presented in the paper. The paper specifies qualitative indices for earth dams which are subdivided in two groups: applicability factors and structural reliability factors. A short analysis of all possible causes for accident initiation at earth dams has been made and the analysis has permitted to pinpoint eleven main objects for diagnosis for slime storage dams. In order to assess risk degree of accident initiation at JSC “Belaruskali” slime storages all possible causes of emergency cases and their probability of occurrence have been analyzed in the paper. The paper acknowledges the fact that dam malfunction is possible, as a rule, due to violation of operational rules and regulations. Main parameters of slime storage state which are to be controlled regularly in the process of its operation have been noted in the paper. Observation results over slime storages, calculations of dam slope stability for normal operation (a principal calculation case and operating irregularities in water seals (a special calculation case. As a stability margin factor is close to 1.0 for a special calculation case, an extreme position of depression curve has been determined for all design sections. It has been recommended to carry out a constant control over its position, and in the case when it reaches its peak value it is necessary to undertake appropriate measures in order to reduce its value. Final expert estimations on probability of accident initiation at the investigated slime storage dams of the 4th Mining Administration, JSC “Belaruskali” have been prepared on the basis of the analysis comprising all the required factors. A conclusion has been made about low risk degree of their destruction.

  16. The effect of mold surface topography on plastic parat in-process shrinkage in injection molding

    DEFF Research Database (Denmark)

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

    2003-01-01

    An experimental study of the effect of mold surface roughness on in-process in-flow linear part shrinkage in injection molding has been carried out. The investigation is based on an experimental two-cavity tool, where the cavities have different surface topographies, but are otherwise identical....... The study has been carried out for typical commercial polystyrene and polypropylene grades. The relationship between mold surface topography and linear shrinkage has been investigated with an experimental two-cavity mold producing simple rectangular parts with the nominal dimensions 1 x 25 x 50 mm (see...... figure 1). The cavities have different surface topographies on one side, but are otherwise identical (see discussion of other contribution factors)....

  17. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Phenolic resins in molded articles. 177.2410... as Components of Articles Intended for Repeated Use § 177.2410 Phenolic resins in molded articles. Phenolic resins identified in this section may be safely used as the food-contact surface of molded...

  18. Analysis of cracking in glass molds made of cast iron

    Science.gov (United States)

    Leushin, I. O.; Chistyakov, D. G.

    2014-09-01

    The cracking in the parts of cast iron molds intended for glass is considered, and this cracking substantially affects the operation of glass-blowing equipment, maintainability, and the replacement of mold sets. The processes that cause cracking in the parts of glass molds and initiate crack growth are studied.

  19. Diagnosis of mold allergy by RAST and skin prick testing.

    Science.gov (United States)

    Nordvall, S L; Agrell, B; Malling, H J; Dreborg, S

    1990-11-01

    Sera from 33 patients with mold allergy proven by bronchial provocation were analyzed for specific IgE against six mold species comparing an improved Phadebas RAST with four other techniques. The new method was more sensitive and gave significantly higher IgE antibody concentrations for all tested molds except Cladosporium herbarum.

  20. Purification of Gold from Chloride Leach Liquor of Copper Anode Slime by Octanol-Kerosene Organic Extractant

    OpenAIRE

    N. Sadeghi; E. Keshavarz Alamdari

    2015-01-01

    In the present study, the copper anode slime was leached in chloride media. Then, pregnant leach solution (PLS) was purified using solvent extraction method and Octanol-kerosene solution. HAuCl4.2L was determined as the extracted macromolecule, and separation of impurities, such as copper, iron and selenium was done in the presence of gold. McCabe-Thiele diagram of Au–HCl (3 M)– Octanol (40% v/v) in O/A=3/4 showed that Au concentration in aqueous phase decreased from the initial value of 200 ...

  1. Hydrophobicity Tuning by the Fast Evolution of Mold Temperature during Injection Molding

    Directory of Open Access Journals (Sweden)

    Sara Liparoti

    2018-03-01

    Full Text Available The surface topography of a molded part strongly affects its functional properties, such as hydrophobicity, cleaning capabilities, adhesion, biological defense and frictional resistance. In this paper, the possibility to tune and increase the hydrophobicity of a molded polymeric part was explored. An isotactic polypropylene was injection molded with fast cavity surface temperature evolutions, obtained adopting a specifically designed heating system layered below the cavity surface. The surface topology was characterized by atomic force microscopy (AFM and, concerning of hydrophobicity, by measuring the water static contact angle. Results show that the hydrophobicity increases with both the temperature level and the time the cavity surface temperature was kept high. In particular, the contact angle of the molded sample was found to increase from 90°, with conventional molding conditions, up to 113° with 160 °C of cavity surface temperature kept for 18 s. This increase was found to be due to the presence of sub-micro and nano-structures characterized by high values of spatial frequencies which could be more accurately replicated by adopting high heating temperatures and times. The surface topography and the hydrophobicity resulted therefore tunable by selecting appropriate injection molding conditions.

  2. Mold exposure and health effects following hurricanes Katrina and Rita.

    Science.gov (United States)

    Barbeau, Deborah N; Grimsley, L Faye; White, LuAnn E; El-Dahr, Jane M; Lichtveld, Maureen

    2010-01-01

    The extensive flooding in the aftermath of Hurricanes Katrina and Rita created conditions ideal for indoor mold growth, raising concerns about the possible adverse health effects associated with indoor mold exposure. Studies evaluating the levels of indoor and outdoor molds in the months following the hurricanes found high levels of mold growth. Homes with greater flood damage, especially those with >3 feet of indoor flooding, demonstrated higher levels of mold growth compared with homes with little or no flooding. Water intrusion due to roof damage was also associated with mold growth. However, no increase in the occurrence of adverse health outcomes has been observed in published reports to date. This article considers reasons why studies of mold exposure after the hurricane do not show a greater health impact.

  3. A comparison of molding procedures - Contact, injection and vacuum injection

    Science.gov (United States)

    Cathiard, G.

    1980-06-01

    The technical and economic aspects of the contact, injection and vacuum injection molding of reinforced plastic components are compared for the example of a tractor roof with a gel-coated surface. Consideration is given to the possibility of reinforcement, number of smooth faces, condition of the gel-coated surface, reliability, and labor and workplace requirements of the three processes, and advantages of molding between the mold and a countermold in smooth faces, reliability, labor requirements, working surface and industrial hygiene are pointed out. The times and labor requirements of each step in the molding cycles are examined, and material requirements and yields, investment costs, amortization and product cost prices of the processes are compared. It is concluded that, for the specific component examined, the processes of vacuum injection and injection molding appear very interesting, with injection molding processes resulting in lower cost prices than contact molding for any production volume.

  4. Direct molding of pavement tiles made of ground tire rubber

    Science.gov (United States)

    Quadrini, Fabrizio; Gagliardi, Donatella; Tedde, Giovanni Matteo; Santo, Loredana; Musacchi, Ettore

    2016-10-01

    Large rubber products can be molded by using only ground tire rubber (GTR) without any additive or binder due to a new technology called "direct molding". Rubber granules and powders from tire recycling are compression molded at elevated temperatures and pressures. The feasibility of this process was clearly shown in laboratory but the step to the industrial scale was missing. Thanks to an European Project (SMART "Sustainable Molding of Articles from Recycled Tires") this step has been made and some results are reported in this study. The press used for compression molding is described. Some tests were made to measure the energy consumption so as to evaluate costs for production in comparison with conventional technologies for GTR molding (by using binders). Results show that 1 m2 tiles can be easily molded with several thicknesses in a reasonable low time. Energy consumption is higher than conventional technologies but it is lower than the cost for binders.

  5. Use of a colorimetric (DELI) test for the evaluation of chemoresistance of Plasmodium falciparum and Plasmodium vivax to commonly used anti-plasmodial drugs in the Brazilian Amazon.

    Science.gov (United States)

    Pratt-Riccio, Lilian R; Chehuan, Yonne F; Siqueira, Maria José; das Graças Alecrim, Maria; Bianco-Junior, Cesare; Druilhe, Pierre; Brasseur, Philippe; de Fátima Ferreira-da-Cruz, Maria; Carvalho, Leonardo J M; Daniel-Ribeiro, Cláudio T

    2013-08-12

    The emergence and spread of Plasmodium falciparum and Plasmodium vivax resistance to available anti-malarial drugs represents a major drawback in the control of malaria and its associated morbidity and mortality. The aim of this study was to evaluate the chemoresistance profile of P. falciparum and P. vivax to commonly used anti-plasmodial drugs in a malaria-endemic area in the Brazilian Amazon. The study was carried out in Manaus (Amazonas state), in the Brazilian Amazon. A total of 88 P. falciparum and 178 P. vivax isolates was collected from 2004 to 2007. The sensitivity of P. falciparum isolates was determined to chloroquine, quinine, mefloquine and artesunate and the sensitivity of P. vivax isolates was determined to chloroquine and mefloquine, by using the colorimetric DELI test. As expected, a high prevalence of P. falciparum isolates resistant to chloroquine (78.1%) was observed. The prevalence of isolates with profile of resistance or decreased sensitivity for quinine, mefloquine and artesunate was 12.7, 21.2 and 11.7%, respectively. In the case of P. vivax, the prevalence of isolates with profile of resistance for chloroquine and mefloquine was 9.8 and 28%, respectively. No differences in the frequencies of isolates with profile of resistance or geometric mean IC50s were seen when comparing the data obtained in 2004, 2005, 2006 and 2007, for all tested anti-malarials. The great majority of P. falciparum isolates in the Brazilian malaria-endemic area remain resistant to chloroquine, and the decreased sensitivity to quinine, mefloquine and artesunate observed in 10-20% of the isolates must be taken with concern, especially for artesunate. Plasmodium vivax isolates also showed a significant proportion of isolates with decreased sensitivity to chloroquine (first-line drug) and mainly to mefloquine. The data presented here also confirm the usefulness of the DELI test to generate results able to impact on public health policies.

  6. Molding of L band niobium superconductor cavity

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Hitoshi; Funahashi, Yoshisato; Saito, Kenji; Noguchi, Shuichi; Koizumi, Susumu [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1995-07-01

    A cavity to produce high accelerating electron field was developed. The L-band (1.3 GHz) niobium superconductor unit cell cavity was ellipsoid with {phi}217.3 mm outer diameter and 2.5 mm thickness and consisted of two pieces of half cell, two beam pipes and flange. A deep drawing process was adapted. In spite of the first trial manufacture, each good cavity was obtained. Characteristic properties of niobium materials, molding method of cavity, extension of sheet after molding, production of beam pipe, accuracy and the cost were explained. Niobium materials. showed tensile strength 15.6 kg/mm{sup 2}, load-carrying capacity 4.1 kg/mm{sup 2}, density 8.57, extension 42.5% and RRR (resistance residual ratio){>=}200. (S.Y.)

  7. Manufacturing Science of Improved Molded Optics

    Science.gov (United States)

    2013-12-05

    Evaluation of a Bench-Top Precision Glass Molding Machine, Advances in Mechanical Engineering, (04 2013): 0. doi: 10.1155/2013/178680 Erick Koontz ...reviewed journals: 3.00 (b) Papers published in non-peer-reviewed journals (N/A for none) E. Koontz , P. Wachtel, J. David Musgraves, K. Richardson...2013 Conference, Rochester, NY October 14-17 2013. E. Koontz , P. Wachtel, J. David Musgraves, K. Richardson, S. Mourad, M. Huber, A. Kunz, M

  8. Pink slimed: Media framing of novel food technologies and risk related to ground beef and processed foods in the U.S.

    Science.gov (United States)

    Runge, Kristin K; Chung, Jennifer H; Su, Leona Yi-Fan; Brossard, Dominique; Scheufele, Dietram A

    2018-09-01

    In March 2012 ABC World News Report aired a series of reports on lean finely textured beef (LFTB) that resulted in a 10-year low for beef prices and the bankruptcy of a major firm that produced LFTB. Using a random sample survey, we tested the effects of the media frame "pink slime" and industry frame "lean finely textured beef," alongside media use, food-related knowledge, trust in food-related institutions and preference for local, fresh, organic and GMO-free foods on perceptions of risk related to ground beef containing pink slime/LFTB, processed foods and red meat. The "pink slime" frame was strongly and positively associated with risk related to ground beef, but not risk related to red meat or processed foods. Attention to news stories about pink slime/LFTB was strongly associated with risk related to ground beef and processed foods, but not red meat. We found varying effects of food values, knowledge and trust on all three dependent variables. Implications are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Adaptive temporal refinement in injection molding

    Science.gov (United States)

    Karyofylli, Violeta; Schmitz, Mauritius; Hopmann, Christian; Behr, Marek

    2018-05-01

    Mold filling is an injection molding stage of great significance, because many defects of the plastic components (e.g. weld lines, burrs or insufficient filling) can occur during this process step. Therefore, it plays an important role in determining the quality of the produced parts. Our goal is the temporal refinement in the vicinity of the evolving melt front, in the context of 4D simplex-type space-time grids [1, 2]. This novel discretization method has an inherent flexibility to employ completely unstructured meshes with varying levels of resolution both in spatial dimensions and in the time dimension, thus allowing the use of local time-stepping during the simulations. This can lead to a higher simulation precision, while preserving calculation efficiency. A 3D benchmark case, which concerns the filling of a plate-shaped geometry, is used for verifying our numerical approach [3]. The simulation results obtained with the fully unstructured space-time discretization are compared to those obtained with the standard space-time method and to Moldflow simulation results. This example also serves for providing reliable timing measurements and the efficiency aspects of the filling simulation of complex 3D molds while applying adaptive temporal refinement.

  10. Chemorheology of in-mold coating for compression molded SMC applications

    Science.gov (United States)

    Ko, Seunghyun; Straus, Elliott J.; Castro, Jose M.

    2015-05-01

    In-mold coating (IMC) is applied to compression molded sheet molding compound (SMC) exterior automotive or truck body panels as an environmentally friendly alternative to make the surface conductive for subsequent electrostatic painting operations. The coating is a thermosetting liquid that when injected onto the surface of the part cures and bonds to provide a smooth conductive surface. In order to optimize the IMC process, it is essential to predict the time available for flow, that is the time before the thermosetting reaction starts (inhibition time) as well as the time when the coating has enough structural integrity so that the mold can be opened without damaging the part surface (cure time). To predict both the inhibition time and the cure time, it is critical to study the chemorheology of IMC. In this paper, we study the chemorheology for a typical commercial IMC system, and show its relevance to both the flow and cure time for the IMC stage during SMC compression molding.

  11. Microinjection molding of thermoplastic polymers: morphological comparison with conventional injection molding

    International Nuclear Information System (INIS)

    Giboz, Julien; Mélé, Patrice; Copponnex, Thierry

    2009-01-01

    The skin–core crystalline morphology of injection-molded semi-crystalline polymers is well documented in the scientific literature. The thermomechanical environment provokes temperature and shear gradients throughout the entire thickness of the part during molding, thus influencing the polymer crystallization. Crystalline morphologies of a high-density polyethylene (HDPE) micromolded part (μpart) and a classical part (macropart) are compared with optical, thermal and x-ray diffraction analyses. Results show that the crystalline morphologies with regard to thickness vary between the two parts. While a 'skin–core' morphology is present for the macropart, the μpart exhibits a specific 'core-free' morphology, i.e. no spherulite is present at the center of the thickness. This result seems to be generated under the specific conditions used in microinjection molding that lead to the formation of smaller and more oriented crystalline entities

  12. Predicting shrinkage and warpage in injection molding: Towards automatized mold design

    Science.gov (United States)

    Zwicke, Florian; Behr, Marek; Elgeti, Stefanie

    2017-10-01

    It is an inevitable part of any plastics molding process that the material undergoes some shrinkage during solidification. Mainly due to unavoidable inhomogeneities in the cooling process, the overall shrinkage cannot be assumed as homogeneous in all volumetric directions. The direct consequence is warpage. The accurate prediction of such shrinkage and warpage effects has been the subject of a considerable amount of research, but it is important to note that this behavior depends greatly on the type of material that is used as well as the process details. Without limiting ourselves to any specific properties of certain materials or process designs, we aim to develop a method for the automatized design of a mold cavity that will produce correctly shaped moldings after solidification. Essentially, this can be stated as a shape optimization problem, where the cavity shape is optimized to fulfill some objective function that measures defects in the molding shape. In order to be able to develop and evaluate such a method, we first require simulation methods for the diffierent steps involved in the injection molding process that can represent the phenomena responsible for shrinkage and warpage ina sufficiently accurate manner. As a starting point, we consider the solidification of purely amorphous materials. In this case, the material slowly transitions from fluid-like to solid-like behavior as it cools down. This behavior is modeled using adjusted viscoelastic material models. Once the material has passed a certain temperature threshold during cooling, any viscous effects are neglected and the behavior is assumed to be fully elastic. Non-linear elastic laws are used to predict shrinkage and warpage that occur after this point. We will present the current state of these simulation methods and show some first approaches towards optimizing the mold cavity shape based on these methods.

  13. Three-Dimensional Modeling of Glass Lens Molding

    DEFF Research Database (Denmark)

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

    2015-01-01

    The required accuracy for the final dimensions of the molded lenses in wafer-based precision glass molding as well as the need for elimination of costly experimental trial and error calls for numerical simulations. This study deals with 3D thermo-mechanical modeling of the wafer-based precision...... glass lens molding process. First, a comprehensive 3D thermo-mechanical model of glass is implemented into a FORTRAN user subroutine (UMAT) in the FE program ABAQUS, and the developed FE model is validated with both a well-known sandwich seal test and experimental results of precision molding of several...... glass rings. Afterward, 3D thermo-mechanical modeling of the wafer-based glass lens manufacturing is performed to suggest a proper molding program (i.e., the proper set of process parameters including preset force-time and temperature-time histories) for molding a wafer to a desired dimension...

  14. Evacuated, displacement compression mold. [of tubular bodies from thermosetting plastics

    Science.gov (United States)

    Heier, W. C. (Inventor)

    1974-01-01

    A process of molding long thin-wall tubular bodies from thermosetting plastic molding compounds is described wherein the tubular body lengths may be several times the diameters. The process is accomplished by loading a predetermined quantity of molding compound into a female mold cavity closed at one end by a force mandrel. After closing the other end of the female mold with a balance mandrel, the loaded cavity is evacuated by applying a vacuum of from one-to-five mm pressure for a period of fifteen-to-thirty minutes. The mold temperature is raised to the minimum temperature at which the resin constituent of the compound will soften or plasticize and a pressure of 2500 psi is applied.

  15. Understanding the impact of molds on indoor air quality and ...

    Science.gov (United States)

    Molds are multi-celled, colony forming, eukaryotic microorganisms lacking chlorophyll belonging to the Kingdom Fungi. Furthermore, molds are ubiquitous in both indoor and outdoor environments. There are more than 200 different types of fungi to which people are routinely exposed (NAS. 2000). The growth of molds in homes, schools, offices, and other public buildings has been implicated as the cause of a wide variety of adverse health effects. Headlines resulting from moldy, water-damaged homes, particularly

  16. Characterization of wood-based molding bonded with citric acid

    OpenAIRE

    Umemura, Kenji; Ueda, Tomohide; Kawai, Shuichi

    2012-01-01

    The wood-based moldings were fabricated by using only citric acid as an adhesive. The mechanical properties, water resistances, thermal properties and chemical structure were investigated. Wood powder obtained from Acacia mangium was mixed with citric acid under certain weight ratios (0-40 wt%), and each powder mixture was molded using two types of metal molds at 200 °C and 4MPa for 10 min. The modulus of rupture (MOR) and the modulus of elasticity (MOE) values of the wood-based molding conta...

  17. Deformation analysis considering thermal expansion of injection mold

    International Nuclear Information System (INIS)

    Kim, Jun Hyung; Yi, Dae Eun; Jang, Jeong Hui; Lee, Min Seok

    2015-01-01

    In the design of injection molds, the temperature distribution and deformation of the mold is one of the most important parameters that affect the flow characteristics, flash generation, and surface appearance, etc. Plastic injection analyses have been carried out to predict the temperature distribution of the mold and the pressure distribution on the cavity surface. As the input loads, we transfer the temperature and pressure results to the structural analysis. We compare the structural analysis results with the thermal expansion effect using the actual flash and step size of a smartphone cover part. To reduce the flash problem, we proposed a new mold design, and verified the results by performing simulations

  18. Additive Manufacturing of Molds for Fabrication of Insulated Concrete Block

    Energy Technology Data Exchange (ETDEWEB)

    Love, Lonnie J. [ORNL; Lloyd, Peter D. [ORNL

    2018-02-01

    ORNL worked with concrete block manufacturer, NRG Insulated Block, to demonstrate additive manufacturing of a multi-component block mold for its line of insulated blocks. Solid models of the mold parts were constructed from existing two-dimensional drawings and the parts were fabricated on a Stratasys Fortus 900 using ULTEM 9085. Block mold parts were delivered to NRG and installed on one of their fabrication lines. While form and fit were acceptable, the molds failed to function during NRG’s testing.

  19. Replication of optical microlens arrays using photoresist coated molds

    DEFF Research Database (Denmark)

    Chakrabarti, Maumita; Dam-Hansen, Carsten; Stubager, Jørgen

    2016-01-01

    A cost reduced method of producing injection molding tools is reported and demonstrated for the fabrication of optical microlens arrays. A standard computer-numerical-control (CNC) milling machine was used to make a rough mold in steel. Surface treatment of the steel mold by spray coating...... with photoresist is used to smooth the mold surface providing good optical quality. The tool and process are demonstrated for the fabrication of an ø50 mm beam homogenizer for a color mixing LED light engine. The acceptance angle of the microlens array is optimized, in order to maximize the optical efficiency from...

  20. Deformation analysis considering thermal expansion of injection mold

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Hyung; Yi, Dae Eun; Jang, Jeong Hui; Lee, Min Seok [Samsung Electronics Co., LTD., Seoul (Korea, Republic of)

    2015-09-15

    In the design of injection molds, the temperature distribution and deformation of the mold is one of the most important parameters that affect the flow characteristics, flash generation, and surface appearance, etc. Plastic injection analyses have been carried out to predict the temperature distribution of the mold and the pressure distribution on the cavity surface. As the input loads, we transfer the temperature and pressure results to the structural analysis. We compare the structural analysis results with the thermal expansion effect using the actual flash and step size of a smartphone cover part. To reduce the flash problem, we proposed a new mold design, and verified the results by performing simulations.

  1. Comparison of two setups for induction heating in injection molding

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano

    2015-01-01

    To eliminate defects and improve the quality of molded parts, increasing the mold temperature is one of the applicable solutions. A high mold temperature can increase the path flow of the polymer inside the cavity allowing reduction of the number of injection points, reduction of part thickness......, and moulding of smaller and more complex geometries. The last two aspects are very important in micro injection molding. In this paper, a new embedded induction heating system is proposed and validated and two different coil setups were tested and compared. An experimental investigation was performed based...

  2. Applying simulation to optimize plastic molded optical parts

    Science.gov (United States)

    Jaworski, Matthew; Bakharev, Alexander; Costa, Franco; Friedl, Chris

    2012-10-01

    Optical injection molded parts are used in many different industries including electronics, consumer, medical and automotive due to their cost and performance advantages compared to alternative materials such as glass. The injection molding process, however, induces elastic (residual stress) and viscoelastic (flow orientation stress) deformation into the molded article which alters the material's refractive index to be anisotropic in different directions. Being able to predict and correct optical performance issues associated with birefringence early in the design phase is a huge competitive advantage. This paper reviews how to apply simulation analysis of the entire molding process to optimize manufacturability and part performance.

  3. Purification of Gold from Chloride Leach Liquor of Copper Anode Slime by Octanol-Kerosene Organic Extractant

    Directory of Open Access Journals (Sweden)

    N. Sadeghi

    2015-07-01

    Full Text Available In the present study, the copper anode slime was leached in chloride media. Then, pregnant leach solution (PLS was purified using solvent extraction method and Octanol-kerosene solution. HAuCl4.2L was determined as the extracted macromolecule, and separation of impurities, such as copper, iron and selenium was done in the presence of gold. McCabe-Thiele diagram of Au–HCl (3 M– Octanol (40% v/v in O/A=3/4 showed that Au concentration in aqueous phase decreased from the initial value of 200 to 7 mg/L, after 5 stages. Ammonia solution was proposed as the stripper and McCabe-Thiele diagram was presented to obtain the number of gold stripping steps by ammonia solution

  4. Reuse of Anode Slime Generated by the Zinc Industry to Obtain a Liquor for Manufacturing Electrolytic Manganese

    Science.gov (United States)

    Ayala, J.; Fernández, B.

    2013-08-01

    A hydrometallurgical process is proposed in this article to recover manganese from a zinc electrowinning residue. The article describes the digestion-leaching experiments, precipitation, and electrowinning assays to recover Mn from this residue. Anode slime is treated with sulfuric acidic in a furnace within a temperature range of 400-450°C, leached with water, and then filtered. The results show that the dissolution of manganese increases with increasing temperature in the digestion step. The recovery yield of manganese was higher than 90%. As manganese electrolysis requires an electrolyte free of Zn, Ni, Co, and Cu pollutants, the sulfuric acid liquor needs a purification step. Na2S is used to remove pollutants. The results obtained in this study have shown that the proposed process for the recovery of manganese from this type of residue is technically viable.

  5. Molding method of buffer material for underground disposal of radiation-contaminated material, and molded buffer material

    International Nuclear Information System (INIS)

    Akasaka, Hidenari; Shimura, Satoshi; Kawakami, Susumu; Ninomiya, Nobuo; Yamagata, Junji; Asano, Eiichi

    1995-01-01

    Upon molding of a buffer material to be used upon burying a vessel containing radiation-contaminated materials in a sealed state, a powdery buffer material to be molded such as bentonite is disposed at the periphery of a mandrel having a cylindrical portion somewhat larger than contaminate container to be subjected to underground disposal. In addition, it is subjected to integration-molding such as cold isotropic press with a plastic film being disposed therearound, to form a molding product at high density. The molding product is released and taken out with the plastic film being disposed thereon. Releasability from an elastic mold is improved by the presence of the plastic film. In addition, if it is stored or transported while having the plastic film being disposed thereon, swelling of the buffer material due to water absorption or moisture absorption can be suppressed. (T.M.)

  6. Mechanical Properties Distribution within Polypropylene Injection Molded Samples: Effect of Mold Temperature under Uneven Thermal Conditions

    Directory of Open Access Journals (Sweden)

    Sara Liparoti

    2017-11-01

    Full Text Available The quality of the polymer parts produced by injection molding is strongly affected by the processing conditions. Uncontrolled deviations from the proper process parameters could significantly affect both internal structure and final material properties. In this work, to mimic an uneven temperature field, a strong asymmetric heating is applied during the production of injection-molded polypropylene samples. The morphology of the samples is characterized by optical and atomic force microscopy (AFM, whereas the distribution of mechanical modulus at different scales is obtained by Indentation and HarmoniX AFM tests. Results clearly show that the temperature differences between the two mold surfaces significantly affect the morphology distributions of the molded parts. This is due to both the uneven temperature field evolutions and to the asymmetric flow field. The final mechanical property distributions are determined by competition between the local molecular stretch and the local structuring achieved during solidification. The cooling rate changes affect internal structures in terms of relaxation/reorganization levels and give rise to an asymmetric distribution of mechanical properties.

  7. Production of Liquid Metal Spheres by Molding

    Directory of Open Access Journals (Sweden)

    Mohammed G. Mohammed

    2014-10-01

    Full Text Available This paper demonstrates a molding technique for producing spheres composed of eutectic gallium-indium (EGaIn with diameters ranging from hundreds of microns to a couple millimeters. The technique starts by spreading EGaIn across an elastomeric sheet featuring cylindrical reservoirs defined by replica molding. The metal flows into these features during spreading. The spontaneous formation of a thin oxide layer on the liquid metal keeps the metal flush inside these reservoirs. Subsequent exposure to acid removes the oxide and causes the metal to bead up into a sphere with a size dictated by the volume of the reservoirs. This technique allows for the production and patterning of droplets with a wide range of volumes, from tens of nanoliters up to a few microliters. EGaIn spheres can be embedded or encased subsequently in polymer matrices using this technique. These spheres may be useful as solder bumps, electrodes, thermal contacts or components in microfluidic devices (valves, switches, pumps. The ease of parallel-processing and the ability to control the location of the droplets during their formation distinguishes this technique.

  8. Composite fabrication via resin transfer molding technology

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, G.M.; Domeier, L.A.

    1996-04-01

    The IMPReS (Integrated Modeling and Processing of Resin-based Structures) Program was funded in FY95 to consolidate, evaluate and enhance Sandia`s capabilities in the design and fabrication of composite structures. A key driver of this and related programs was the need for more agile product development processes and for model based design and fabrication tools across all of Sandia`s material technologies. A team of polymer, composite and modeling personnel was assembled to benchmark Sandia`s existing expertise in this area relative to industrial and academic programs and to initiate the tasks required to meet Sandia`s future needs. RTM (Resin Transfer Molding) was selected as the focus composite fabrication technology due to its versatility and growing use in industry. Modeling efforts focused on the prediction of composite mechanical properties and failure/damage mechanisms and also on the uncured resin flow processes typical of RTM. Appropriate molds and test composites were fabricated and model validation studies begun. This report summarizes and archives the modeling and fabrication studies carried out under IMPReS and evaluates the status of composite technology within Sandia. It should provide a complete and convenient baseline for future composite technology efforts within Sandia.

  9. Injection molded polymer optics in the 21st Century

    Science.gov (United States)

    Beich, William S.

    2005-08-01

    Precision polymer optics, manufactured by injection molding techniques, has been a key enabling technology for several decades now. The technology, which can be thought of as a subset of the wider field of precision optics manufacturing, was pioneered in the United States by companies such as Eastman Kodak, US Precision Lens, and Polaroid. In addition to suppliers in the U.S. there are several companies worldwide that design and manufacture precision polymer optics, for example Philips High Tech Plastics in Europe and Fujinon in Japan. Designers who are considering using polymer optics need a fundamental understanding of exactly how the optics are created. This paper will survey the technology and processes that are employed in the successful implementation of a polymer optic solution from a manufacturer's perspective. Special emphasis will be paid to the unique relationship between the molds and the optics that they produce. We will discuss the key elements of production: molding resins, molds and molding equipment, and metrology. Finally we will offer a case study to illustrate just how the optics designer carries a design concept through to production. The underlying theme throughout the discussion of polymer optics is the need for the design team to work closely with an experienced polymer optics manufacturer with a solid track record of success in molded optics. As will be seen shortly, the complex interaction between thermoplastics, molds, and molding machines dictates the need for working closely with a supplier who has the critical knowledge needed to manage all aspects of the program.

  10. METHOD FOR EVALUATING MOLD GROWTH ON CEILING TILE

    Science.gov (United States)

    A method to extract mold spores from porous ceiling tiles was developed using a masticator blender. Ceiling tiles were inoculated and analyzed using four species of mold. Statistical analysis comparing results obtained by masticator extraction and the swab method was performed. T...

  11. Evaluation of Additive Manufacturing for High Volume Composite Part Molds

    Energy Technology Data Exchange (ETDEWEB)

    Duty, Chad E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kunc, Vlastimil [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lokitz, Bradley S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Springfield, Robert M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-05-01

    ORNL worked with TruDesign, LLC to develop viable coating solutions to enable the use of large scale 3D printing for both low-temperature and high-temperature composite molds. This project resulted in two commercial products and successfully demonstrated the use of printed molds for autoclave processing for the first time.

  12. Production application of injection-molded diffractive elements

    Science.gov (United States)

    Clark, Peter P.; Chao, Yvonne Y.; Hines, Kevin P.

    1995-12-01

    We demonstrate that transmission kinoforms for visible light applications can be injection molded in acrylic in production volumes. A camera is described that employs molded Fresnel lenses to change the convergence of a projection ranging system. Kinoform surfaces are used in the projection system to achromatize the Fresnel lenses.

  13. Injection molded polymeric hard X-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik; Simons, Hugh; Jakobsen, Anders Clemen

    2015-01-01

    of the etching profile and were removed after DRIE. By electroplating, an inverse nickel sample was obtained, which was used as a mold insert in a commercial polymer injection molding machine. A prototype lens made of polyethylene with a focal length of 350 mm was tested using synchrotron radiation at photon...

  14. Taxonomic re-evaluation of black koji molds

    NARCIS (Netherlands)

    Hong, S.B.; Yamada, O.; Samson, R.A.

    2013-01-01

    Black koji molds including its albino mutant, the white koji mold, have been widely used for making the distilled spirit shochu in Northeast Asia because they produce citric acid which prevents undesirable contamination from bacteria. Since Inui reported Aspergillus luchuensis from black koji in

  15. Azole-based antimycotic agents inhibit mold on unseasoned pine

    Science.gov (United States)

    Carol. A. Clausen; Vina W. Yang

    2005-01-01

    Inhibiting the growth of mold fungi on cellulose-based building materials may be achievable through the use of azole-based antimycotics. Azoles were variably effective against mold fungi that are frequently found on wood and wood products. Unseasoned southern yellow pine specimens that were dip-treated with varying concentrations of eight azoles were evaluated for...

  16. Multi-height structures in injection molded polymer

    DEFF Research Database (Denmark)

    Andersen, Nis Korsgaard; Taboryski, Rafael J.

    2015-01-01

    of different geometries, and electroforming a nickel mold from a polymer foil. The injection-molded samples are characterized by contact angle hysteresis obtained by the tilting method. We find that the receding contact angle depends on the surface coverage of the random surface structure, while the advancing...

  17. Mathematical modeling of the in-mold coating process for injection-molded thermoplastic parts

    Science.gov (United States)

    Chen, Xu

    In-Mold Coating (IMC) has been successfully used for many years for exterior body panels made from compression molded Sheet Molding Compound (SMC). The coating material is a single component reactive fluid, designed to improve the surface quality of SMC moldings in terms of functional and cosmetic properties. When injected onto a cured SMC part, IMC cures and bonds to provide a pain-like surface. Because of its distinct advantages, IMC is being considered for application to injection molded thermoplastic parts. For a successful in mold coating operation, there are two key issues related to the flow of the coating. First, the injection nozzle should be located such that the thermoplastic substrate is totally covered and the potential for air trapping is minimized. The selected location should be cosmetically acceptable since it most likely will leave a mark on the coated surface. The nozzle location also needs to be accessible for easy of maintenance. Secondly, the hydraulic force generated by the coating injection pressure should not exceed the available clamping tonnage. If the clamping force is exceeded, coating leakage will occur. In this study, mathematical models for IMC flow on the compressible thermoplastic substrate have been developed. Finite Difference Method (FDM) is first used to solve the 1 dimensional (1D) IMC flow problem. In order to investigate the application of Control Volume based Finite Element Method (CV/FEM) to more complicated two dimensional IMC flow, that method is first evaluated by solving the 1D IMC flow problem. An analytical solution, which can be obtained when a linear relationship between the coating thickness and coating injection pressure is assumed, is used to verify the numerical results. The mathematical models for the 2 dimensional (2D) IMC flow are based on the generalized Hele-Shaw approximation. It has been found experimentally that the power law viscosity model adequately predicts the rheological behavior of the coating

  18. Injection Molding Parameters Calculations by Using Visual Basic (VB) Programming

    Science.gov (United States)

    Tony, B. Jain A. R.; Karthikeyen, S.; Alex, B. Jeslin A. R.; Hasan, Z. Jahid Ali

    2018-03-01

    Now a day’s manufacturing industry plays a vital role in production sectors. To fabricate a component lot of design calculation has to be done. There is a chance of human errors occurs during design calculations. The aim of this project is to create a special module using visual basic (VB) programming to calculate injection molding parameters to avoid human errors. To create an injection mold for a spur gear component the following parameters have to be calculated such as Cooling Capacity, Cooling Channel Diameter, and Cooling Channel Length, Runner Length and Runner Diameter, Gate Diameter and Gate Pressure. To calculate the above injection molding parameters a separate module has been created using Visual Basic (VB) Programming to reduce the human errors. The outcome of the module dimensions is the injection molding components such as mold cavity and core design, ejector plate design.

  19. A poly(dimethylsiloxane)-coated flexible mold for nanoimprint lithography

    International Nuclear Information System (INIS)

    Lee, Nae Yoon; Kim, Youn Sang

    2007-01-01

    In this paper, we introduce an anti-adhesion poly(dimethylsiloxane) (PDMS)-coated flexible mold and its applications for room-temperature imprint lithography. The flexible mold is fabricated using an ultraviolet-curable prepolymer on a flexible substrate, and its surface is passivated with a thin layer of PDMS to impart an anti-adhesion property. The highly flexible mold enables conformal contact with a substrate on which a low-viscosity polymer resist is spin-cast in a thin layer. Large-area imprinting is then realized at room temperature under significantly reduced pressure. The mold was durable even after repetitive imprinting of over 200 times. Also, we show a double imprinting on the substrate with a PDMS-coated replica polymeric mold having 500 nm line patterns. This enables the formation of matrix patterns with varying feature heights in less than 7 min

  20. Mold Flora of Traditional Cheeses Produced in Turkey

    Directory of Open Access Journals (Sweden)

    Musa Yalman

    2016-11-01

    Full Text Available In our country, there are many cheese types that are produced traditionally. Cheeses which produced from cows, sheep and goat milk that matured with spontaneous growth of molds present in livestock skins, pots and similar environments are among them. They are produced traditionally in Mediterrian, Central and Eastern Anatolia regions. Molds that grow spontaneously in cheeses could create public health risk because of their secondary metabolites. Penicillium spp. are the most isolated mold from these cheeses and Penicillium roqueforti is determined as the dominant species. Furthermore, Aspergillus, Alternaria, Mucor, Geotrichum, Cladosporium species have been isolated. It is very important to control the ripening conditions and starter strain selection since some strains were reported as mycotoxin producers. In this review, it has been tried to give general information about traditional production of mold-ripened cheese in Turkey and the mold flora found in traditional cheeses. In addition, public health risk of these cheeses is reported.

  1. Injection molding of bushes made of tribological PEEK composites

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available Polyetheretherketone (PEEK composites have been extensively studied because of the excellent tribological behavior among plastics. However, laboratory specimens and tests are generally discussed, whereas application studies on industrial components are infrequent. In this paper, an injection molded bush made of tribological PEEK was analyzed to correlate wear behavior and molded material structure. Bushes were tested under unlubricated sliding conditions by means of a short wear test. Surface analysis, differential scanning calorimetry (DSC and optical microscopy were used to evaluate the distribution of the different composite fillers (polytetrafluoroethylene, PTFE, graphite particles and carbon microfibers and their effect on the final bush behavior. A significant lack of homogeneity was observed in the molded bush and black bands appeared on the shaft surface after testing due to the sliding. The bush geometry and the injection molding process should be optimized to allow the best tribological behavior of the molded material under working conditions.

  2. Index change of chalcogenide materials from precision glass molding processes

    Science.gov (United States)

    Deegan, J.; Walsh, K.; Lindberg, G.; Benson, R.; Gibson, D.; Bayya, S.; Sanghera, J.; Stover, E.

    2015-05-01

    With the increase in demand for infrared optics for thermal applications and the use of glass molding of chalcogenide materials to support these higher volume optical designs, an investigation of changes to the optical properties of these materials is required. Typical precision glass molding requires specific thermal conditions for proper lens molding of any type of optical glass. With these conditions a change (reduction) of optical index occurs after molding of all oxide glass types and it is presumed that a similar behavior will happen with chalcogenide based materials. We will discuss the effects of a typical molding thermal cycle for use with commercially and newly developed chalcogenide materials and show results of index variation from nominally established material data.

  3. Predicting and preventing mold spoilage of food products.

    Science.gov (United States)

    Dagnas, Stéphane; Membré, Jeanne-Marie

    2013-03-01

    This article is a review of how to quantify mold spoilage and consequently shelf life of a food product. Mold spoilage results from having a product contaminated with fungal spores that germinate and form a visible mycelium before the end of the shelf life. The spoilage can be then expressed as the combination of the probability of having a product contaminated and the probability of mold growth (germination and proliferation) up to a visible mycelium before the end of the shelf life. For products packed before being distributed to the retailers, the probability of having a product contaminated is a function of factors strictly linked to the factory design, process, and environment. The in-factory fungal contamination of a product might be controlled by good manufacturing hygiene practices and reduced by particular processing practices such as an adequate air-renewal system. To determine the probability of mold growth, both germination and mycelium proliferation can be mathematically described by primary models. When mold contamination on the product is scarce, the spores are spread on the product and more than a few spores are unlikely to be found at the same spot. In such a case, models applicable for a single spore should be used. Secondary models can be used to describe the effect of intrinsic and extrinsic factors on either the germination or proliferation of molds. Several polynomial models and gamma-type models quantifying the effect of water activity and temperature on mold growth are available. To a lesser extent, the effect of pH, ethanol, heat treatment, addition of preservatives, and modified atmospheres on mold growth also have been quantified. However, mold species variability has not yet been properly addressed, and only a few secondary models have been validated for food products. Once the probability of having mold spoilage is calculated for various shelf lives and product formulations, the model can be implemented as part of a risk management

  4. Public health and economic impact of dampness and mold

    Energy Technology Data Exchange (ETDEWEB)

    Mudarri, David; Fisk, William J.

    2007-06-01

    The public health risk and economic impact of dampness and mold exposures was assessed using current asthma as a health endpoint. Individual risk of current asthma from exposure to dampness and mold in homes from Fisk et al. (2007), and asthma risks calculated from additional studies that reported the prevalence of dampness and mold in homes were used to estimate the proportion of U.S. current asthma cases that are attributable to dampness and mold exposure at 21% (95% confidence internal 12-29%). An examination of the literature covering dampness and mold in schools, offices, and institutional buildings, which is summarized in the appendix, suggests that risks from exposure in these buildings are similar to risks from exposures in homes. Of the 21.8 million people reported to have asthma in the U.S., approximately 4.6 (2.7-6.3) million cases are estimated to be attributable to dampness and mold exposure in the home. Estimates of the national cost of asthma from two prior studies were updated to 2004 and used to estimate the economic impact of dampness and mold exposures. By applying the attributable fraction to the updated national annual cost of asthma, the national annual cost of asthma that is attributable to dampness and mold exposure in the home is estimated to be $3.5 billion ($2.1-4.8 billion). Analysis indicates that exposure to dampness and mold in buildings poses significant public health and economic risks in the U.S. These findings are compatible with public policies and programs that help control moisture and mold in buildings.

  5. ''Heat Transfer at the Mold-Metal Interface in Permanent Mold Casting of Aluminum Alloys'' Final Project Report; FINAL

    International Nuclear Information System (INIS)

    Pehlke, R. D.; Cookson, John M.; Shouwei Hao; Prasad Krishna; Bilkey, Kevin T.

    2001-01-01

    This project on heat transfer coefficients in metal permanent mold casting has been conducted in three areas. They are the theoretical study at the University of Michigan, the experimental investigation of squeeze casting at CMI-Tech Center (Now Hayes-Lemmerz Technical Center) and the experimental investigation of low pressure permanent mold casting at Amcast Automotive

  6. Mold heating and cooling microprocessor conversion

    Science.gov (United States)

    Hoffman, D. P.

    1995-07-01

    Conversion of the microprocessors and software for the Mold Heating and Cooling (MHAC) pump package control systems was initiated to allow required system enhancements and provide data communications capabilities with the Plastics Information and Control System (PICS). The existing microprocessor-based control systems for the pump packages use an Intel 8088-based microprocessor board with a maximum of 64 Kbytes of program memory. The requirements for the system conversion were developed, and hardware has been selected to allow maximum reuse of existing hardware and software while providing the required additional capabilities and capacity. The new hardware will incorporate an Intel 80286-based microprocessor board with an 80287 math coprocessor, the system includes additional memory, I/O, and RS232 communication ports.

  7. Novel route of toxicant exposure in an ancient extant vertebrate: nickel uptake by hagfish skin and the modifying effects of slime.

    Science.gov (United States)

    Glover, Chris N; Blewett, Tamzin A; Wood, Chris M

    2015-02-03

    Utilizing an in vitro technique, the skin of Pacific hagfish (Eptatretus stouti) was shown to take up nickel from the water via a high affinity, low capacity transport pathway. Uptake was biphasic, with saturation occurring at low nickel exposure concentrations, superseded by linear, diffusive uptake at levels greater than 50 μM. In vivo exposures showed that nickel accumulated mainly in the gill, heart, and brain, representing a tissue distribution distinct from that found in teleosts. Slime on the epidermal surface was shown to significantly reduce the uptake of low concentrations (10 μM) of the metals zinc and nickel, but slime had no effect on organic nutrient (the amino acid l-alanine) absorption. At a higher metal exposure concentration (1 mM), slime was no longer protective, indicating saturation of metal-binding sites. This is the first study to show that metals can be taken up by the integument of hagfish. The ability of the skin to act as a transport epithelium may be of particular importance for a burrowing, benthic scavenger, such as hagfish, which are likely to be exposed to relatively enriched levels of metal toxicants through their habitat and lifestyle, and this may have consequences for human health through hagfish consumption.

  8. Degradation of slime extracellular polymeric substances and inhibited sludge flocs destruction contribute to sludge dewaterability enhancement during fungal treatment of sludge using filamentous fungus Mucor sp. GY-1.

    Science.gov (United States)

    Wang, Zhenyu; Zheng, Guanyu; Zhou, Lixiang

    2015-09-01

    Mechanisms responsible for the sludge dewaterability enhanced by filamentous fungi during fungal treatment of sludge were investigated in the present study. The filamentous fungus Mucor sp. GY-1, isolated from waste activated sludge, enhanced sludge dewaterability by 82.1% to achieve the lowest value of normalized sludge specific resistance to filtration (SRF), 8.18 × 10(10) m · L/kg · g-TSS. During the fungal treatment of sludge, 57.8% of slime extracellular polymeric substances (EPS) and 51.1% of polysaccharide in slime EPS were degraded, respectively, by Mucor sp. GY-1, contributing to the improvement of sludge dewaterability. Slime EPS is much more available for Mucor sp. GY-1 than either LB-EPS or TB-EPS that bound with microbial cells. In addition, filamentous fungus Mucor sp. GY-1 entrapped small sludge particles and inhibited the destruction of sludge flocs larger than 100 μm, thus enhancing sludge dewaterability, during fungal treatment of sludge using Mucor sp. GY-1. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Manufacture of mold of polymeric composite water pipe reinforced charcoal

    Science.gov (United States)

    Zulfikar; Misdawati; Idris, M.; Nasution, F. K.; Harahap, U. N.; Simanjuntak, R. K.; Jufrizal; Pranoto, S.

    2018-03-01

    In general, household wastewater pipelines currently use thermoplastic pipes of Polyvinyl Chloride (PVC). This material is known to be not high heat resistant, contains hazardous chemicals (toxins), relatively inhospitable, and relatively more expensive. Therefore, researchers make innovations utilizing natural materials in the form of wood charcoal as the basic material of making the water pipe. Making this pipe requires a simple mold design that can be worked in the scale of household and intermediate industries. This research aims to produce water pipe mold with simple design, easy to do, and making time relatively short. Some considerations for molding materials are weight of mold, ease of raw material, strong, sturdy, and able to cast. Pipe molds are grouped into 4 (four) main parts, including: outer diameter pipe molding, pipe inside diameter, pipe holder, and pipe alignment control. Some materials have been tested as raw materials for outer diameter of pipes, such as wood, iron / steel, cement, and thermoset. The best results are obtained on thermoset material, where the process of disassembling is easier and the resulting mold weight is relatively lighter. For the inside diameter of the pipe is used stainless steel, because in addition to be resistant to chemical processes that occur, in this part of the mold must hold the press load due to shrinkage of raw materials of the pipe during the process of hardening (polymerization). Therefore, it needs high pressure resistant material and does not blend with the raw material of the pipe. The base of the mold is made of stainless steel material because it must be resistant to corrosion due to chemical processes. As for the adjustment of the pipe is made of ST 37 carbon steel, because its function is only as a regulator of the alignment of the pipe structure.

  10. Detecção da produção de slime por estafilococos coagulase-negativa isolados de cateter venoso central

    Directory of Open Access Journals (Sweden)

    E. L. Pizzolitto

    2009-01-01

    Full Text Available

    A produção de slime é um importante fator de virulência dos estafilococos coagulase-negativa, permitindo-lhes aderir sobre as superfícies lisas de biomateriais, e por isso, é associada aos processos de infecção de implantes. No presente estudo a produção de slime em 27 cepas de estafilococos coagulase-negativa foi investigada por cultura em ágar vermelho Congo (77,7% de positividade, método espectrofotométrico ou da microplaca (81,4% de positividade e microscopia eletrônica de varredura (88,9% de positividade. Foi também avaliada a resistência de estafilococos coagulasenegativa a vários antimicrobianos usando a técnica do disco difusão. A porcentagem de resistência à penicilina G, oxacilina, eritromicina, clindamicina e gentamicina em estafilococos produtores de slime foi respectivamente de 88,9%; 70,4%; 81,5%; 66,7% e 59,2%; todos os estafilococos coagulase-negativa foram vancomicina sensíveis. As cepas isoladas de cateter venoso central foram identificadas por método convencional e sistema API Staph. Os 27 estafilococos coagulase-negativa foram identificados como: S. saprophyticus (3,7%, S. xylosus (7,4%, S. haemolyticus (14,8%, S. epidermidis (37,0%, S. warneri (14,8%, S. lugdunensis (7,4%, S. hominis (7,4%, S. schleiferi (3,7% e S. chromogenes (3,7%. Pode-se concluir que entre a maioria das espécies Staphylococcus coagulase-negativa houve associação entre a produção de slime, origem nosocomial das cepas e reduzida sensibilidade aos antimicrobianos, sugerindo potencial patogênico no ambiente hospitalar. Palavras-chave: estafilococos coagulase-negativa; slime; fatores de virulência; polissacarídeo extracelular; biofilme; sensibilidade aos antimicrobianos.

  11. Two component micro injection molding for MID fabrication

    DEFF Research Database (Denmark)

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

    2009-01-01

    Molded Interconnect Devices (MIDs) are plastic substrates with electrical infrastructure. The fabrication of MIDs is usually based on injection molding 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 miniaturization of 3D components with electrical infrastructure is attractive. The paper describes possible manufacturing routes and challenges of miniaturized MIDs based on two component micro injection molding...

  12. Indoor visible mold and mold odor are associated with new-onset childhood wheeze in a dose-dependent manner.

    Science.gov (United States)

    Shorter, Caroline; Crane, Julian; Pierse, Nevil; Barnes, Phillipa; Kang, Janice; Wickens, Kristin; Douwes, Jeroen; Stanley, Thorsten; Täubel, Martin; Hyvärinen, Anne; Howden-Chapman, Philippa

    2018-01-01

    Evidence is accumulating that indoor dampness and mold are associated with the development of asthma. The underlying mechanisms remain unknown. New Zealand has high rates of both asthma and indoor mold and is ideally placed to investigate this. We conducted an incident case-control study involving 150 children with new-onset wheeze, aged between 1 and 7 years, each matched to two control children with no history of wheezing. Each participant's home was assessed for moisture damage, condensation, and mold growth by researchers, an independent building assessor and parents. Repeated measures of temperature and humidity were made, and electrostatic dust cloths were used to collect airborne microbes. Cloths were analyzed using qPCR. Children were skin prick tested for aeroallergens to establish atopy. Strong positive associations were found between observations of visible mold and new-onset wheezing in children (adjusted odds ratios ranged between 1.30 and 3.56; P ≤ .05). Visible mold and mold odor were consistently associated with new-onset wheezing in a dose-dependent manner. Measurements of qPCR microbial levels, temperature, and humidity were not associated with new-onset wheezing. The association between mold and new-onset wheeze was not modified by atopic status, suggesting a non-allergic association. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Rapid and Low-cost Prototyping of Medical Devices Using 3D Printed Molds for Liquid Injection Molding

    Science.gov (United States)

    Chung, Philip; Heller, J. Alex; Etemadi, Mozziyar; Ottoson, Paige E.; Liu, Jonathan A.; Rand, Larry; Roy, Shuvo

    2014-01-01

    Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications. PMID:24998993

  14. A new instrument for statistical process control of thermoset molding

    International Nuclear Information System (INIS)

    Day, D.R.; Lee, H.L.; Shepard, D.D.; Sheppard, N.F.

    1991-01-01

    The recent development of a rugged ceramic mold mounted dielectric sensor and high speed dielectric instrumentation now enables monitoring and statistical process control of production molding over thousands of runs. In this work special instrumentation and software (ICAM-1000) was utilized that automatically extracts critical point during the molding process including flow point, viscosity minimum gel inflection, and reaction endpoint. In addition, other sensors were incorporated to measure temperature and pressure. The critical point as well as temperature and pressure were then recorded during normal production and then plotted in the form of statistical process control (SPC) charts. Experiments have been carried out in RIM, SMC, and RTM type molding operations. The influence of temperature, pressure chemistry, and other variables has been investigated. In this paper examples of both RIM and SMC are discussed

  15. Evaluation of stability for monolayer injection molding tools coating

    DEFF Research Database (Denmark)

    Cech, Jiri; Taboryski, Rafael J.

    2012-01-01

    We tested and characterized molecular coating of Aluminium and Nickel prototype molds and mold inserts for polymer replication via injection molding (IM). X-Ray photoelectron spectroscopy (XPS) data, sessile drop contact angles with multiple fluids, surface energy and roughness data have been...... collected and used to predict coating lifetimes. Samples have been characterized immediately after coating, after 500+ IM cycles to test durability and after 7 months to test temporal stability. Sessile drop contact angle was measured for multiple fluids, namely water, di-iodomethane and benzylacohol....... Detectable coating presence was indicated by an increased angle on all post IM samples. To conclude, we present mold coating evaluation method, which is well suited for ultrathin, controlable, covalently bonded coating, that is reasonably durable, affordable, scalable to production, detectable on surface...

  16. Microinjection molding of microsystem components: new aspects in improving performance

    International Nuclear Information System (INIS)

    Yang, Can; Yin, Xiao-Hong; Cheng, Guang-Ming

    2013-01-01

    Microinjection molding (µIM) is considered to be one of the most flexible, reliable and cost effective manufacturing routes to form plastic micro-components for microsystems. The molding machine, mold tool fabrication, material selection and process controlling in this specific field have been greatly developed over the past decades. This review aims to present the new trends towards improving micro-component performance by reviewing the latest developments in this area and by considering potential directions. The key concerns in product and mold designing, essential factors in simulation, and micro-morphology and resultant properties are evaluated and discussed. In addition, the applications, variant processes and outlook for µIM are presented. Throughout this review, decisive considerations in seeking improved performance for microsystem components are highlighted. (topical review)

  17. Method and mold for casting thin metal objects

    Science.gov (United States)

    Pehrson, Brandon P; Moore, Alan F

    2014-04-29

    Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.

  18. Demonstration of pharmaceutical tablet coating process by injection molding technology.

    Science.gov (United States)

    Puri, Vibha; Brancazio, David; Harinath, Eranda; Martinez, Alexander R; Desai, Parind M; Jensen, Keith D; Chun, Jung-Hoon; Braatz, Richard D; Myerson, Allan S; Trout, Bernhardt L

    2018-01-15

    We demonstrate the coating of tablets using an injection molding (IM) process that has advantage of being solvent free and can provide precision coat features. The selected core tablets comprising 10% w/w griseofulvin were prepared by an integrated hot melt extrusion-injection molding (HME-IM) process. Coating trials were conducted on a vertical injection mold machine. Polyethylene glycol and polyethylene oxide based hot melt extruded coat compositions were used. Tablet coating process feasibility was successfully demonstrated using different coating mold designs (with both overlapping and non-overlapping coatings at the weld) and coat thicknesses of 150 and 300 μm. The resultant coated tablets had acceptable appearance, seal at the weld, and immediate drug release profile (with an acceptable lag time). Since IM is a continuous process, this study opens opportunities to develop HME-IM continuous processes for transforming powder to coated tablets. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Josh A. Salmond

    2009-08-07

    The modernization of the Mold Heating and Cooling Pump Package Operator Interface (MHC PP OI) consisted of upgrading the antiquated single board computer with a proprietary operating system to off-the-shelf hardware and off-the-shelf software with customizable software options. The pump package is the machine interface between a central heating and cooling system that pumps heat transfer fluid through an injection or compression mold base on a local plastic molding machine. The operator interface provides the intelligent means of controlling this pumping process. Strict temperature control of a mold allows the production of high quality parts with tight tolerances and low residual stresses. The products fabricated are used on multiple programs.

  20. Cork is used to make tooling patterns and molds

    Science.gov (United States)

    Hoffman, F. J.

    1965-01-01

    Sheet and waste cork are cemented together to provide a tooling pattern or mold. The cork form withstands moderately high temperatures under vacuum or pressure with minimum expansion, shrinkage, or distortion.

  1. Evaluation of Additive Manufacturing for Composite Part Molds

    Energy Technology Data Exchange (ETDEWEB)

    Duty, Chad E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Springfield, Robert M. [Tru Design, LLC, Knoxville, TN (United States)

    2015-02-01

    The ORNL Manufacturing Demonstration Facility (MDF) collaborated with Tru-Design to test the quality and durability of molds used for making fiber reinforced composites using additive manufacturing. The partners developed surface treatment techniques including epoxy coatings and machining to improve the quality of the surface finish. Test samples made using the printed and surface finished molds demonstrated life spans suitable for one-of-a-kind and low-volume applications, meeting the project objective.

  2. CAE for Injection Molding — Past, Present and the Future

    Science.gov (United States)

    Wang, Kuo K.

    2004-06-01

    It is well known that injection molding is the most effective process for mass-producing discrete plastic parts of complex shape to the highest precision at the lowest cost. However, due to the complex property of polymeric materials undergoing a transient non-isothermal process, it is equally well recognized that the quality of final products is often difficult to be assured. This is particularly true when a new mold or material is encountered. As a result, injection molding has often been viewed as an art than a science. During the past few decades, numerical simulation of injection molding process based on analytic models has become feasible for practical use as computers became faster and cheaper continually. A research effort was initiated at the Cornell Injection Molding Program (CIMP) in 1974 under a grant from the National Science Foundation. Over a quarter of the century, CIMP has established some scientific bases ranging from materials characterization, flow analysis, to prediction of part quality. Use of such CAE tools has become common place today in industry. Present effort has been primarily aimed at refinements of many aspects of the process. Computational efficiency and user-interface have been main thrusts by commercial software developers. Extension to 3-dimensional flow analysis for certain parts has drawn some attention. Research activities are continuing on molding of fiber-filled materials and reactive polymers. Expanded molding processes such as gas-assisted, co-injection, micro-molding and many others are continually being investigated. In the future, improvements in simulation accuracy and efficiency will continue. This will include in-depth studies on materials characterization. Intelligent on-line process control may draw more attention in order to achieve higher degree of automation. As Internet technology continues to evolve, Web-based CAE tools for design, production, remote process monitoring and control can come to path. The CAE

  3. Nonlinear core deflection in injection molding

    Science.gov (United States)

    Poungthong, P.; Giacomin, A. J.; Saengow, C.; Kolitawong, C.; Liao, H.-C.; Tseng, S.-C.

    2018-05-01

    Injection molding of thin slender parts is often complicated by core deflection. This deflection is caused by molten plastics race tracking through the slit between the core and the rigid cavity wall. The pressure of this liquid exerts a lateral force of the slender core causing the core to bend, and this bending is governed by a nonlinear fifth order ordinary differential equation for the deflection that is not directly in the position along the core. Here we subject this differential equation to 6 sets of boundary conditions, corresponding to 6 commercial core constraints. For each such set of boundary conditions, we develop an explicit approximate analytical solution, including both a linear term and a nonlinear term. By comparison with finite difference solutions, we find our new analytical solutions to be accurate. We then use these solutions to derive explicit analytical approximations for maximum deflections and for the core position of these maximum deflections. Our experiments on the base-gated free-tip boundary condition agree closely with our new explicit approximate analytical solution.

  4. Mold-filling experiments for validation of modeling encapsulation. Part 1, "wine glass" mold.

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, Jaime N.; Grillet, Anne Mary; Altobelli, Stephen A. (New Mexico Resonance, Albuquerque, NM); Cote, Raymond O.; Mondy, Lisa Ann

    2005-06-01

    The C6 project 'Encapsulation Processes' has been designed to obtain experimental measurements for discovery of phenomena critical to improving these processes, as well as data required in the verification and validation plan (Rao et al. 2001) for model validation of flow in progressively complex geometries. We have observed and recorded the flow of clear, Newtonian liquids and opaque, rheologically complex suspensions in two mold geometries. The first geometry is a simple wineglass geometry in a cylinder and is reported here in Part 1. The results in a more realistic encapsulation geometry are reported in Part 2.

  5. Prediction of Mold Spoilage for Soy/Polyethylene Composite Fibers

    Directory of Open Access Journals (Sweden)

    Chinmay Naphade

    2015-01-01

    Full Text Available Mold spoilage was determined over 109 days on soy/PE fibers held under controlled temperatures (T ranging from 10°C to 40°C and water activities (aw from 0.11 to 0.98. Water activities were created in sealed containers using saturated salt solutions and placed in temperature-controlled incubators. Soy/PE fibers that were held at 0.823 aw or higher exhibited mold growth at all temperatures. As postulated, increased water activity (greater than 0.89 and temperature (higher than 25°C accelerated mold growth on soy/PE fibers. A slower mold growth was observed on soy/PE fibers that were held at 0.87 aw and 10°C. A Weibull model was employed to fit the observed logarithmic values of T, aw, and an interaction term log⁡T×log⁡aw and was chosen as the final model as it gave the best fit to the raw mold growth data. These growth models predict the expected mold-free storage period of soy/PE fibers when exposed to various environmental temperatures and humidities.

  6. Analysis of form deviation in non-isothermal glass molding

    Science.gov (United States)

    Kreilkamp, H.; Grunwald, T.; Dambon, O.; Klocke, F.

    2018-02-01

    Especially in the market of sensors, LED lighting and medical technologies, there is a growing demand for precise yet low-cost glass optics. This demand poses a major challenge for glass manufacturers who are confronted with the challenge arising from the trend towards ever-higher levels of precision combined with immense pressure on market prices. Since current manufacturing technologies especially grinding and polishing as well as Precision Glass Molding (PGM) are not able to achieve the desired production costs, glass manufacturers are looking for alternative technologies. Non-isothermal Glass Molding (NGM) has been shown to have a big potential for low-cost mass manufacturing of complex glass optics. However, the biggest drawback of this technology at the moment is the limited accuracy of the manufactured glass optics. This research is addressing the specific challenges of non-isothermal glass molding with respect to form deviation of molded glass optics. Based on empirical models, the influencing factors on form deviation in particular form accuracy, waviness and surface roughness will be discussed. A comparison with traditional isothermal glass molding processes (PGM) will point out the specific challenges of non-isothermal process conditions. Furthermore, the underlying physical principle leading to the formation of form deviations will be analyzed in detail with the help of numerical simulation. In this way, this research contributes to a better understanding of form deviations in non-isothermal glass molding and is an important step towards new applications demanding precise yet low-cost glass optics.

  7. Classification of buildings mold threat using electronic nose

    Science.gov (United States)

    Łagód, Grzegorz; Suchorab, Zbigniew; Guz, Łukasz; Sobczuk, Henryk

    2017-07-01

    Mold is considered to be one of the most important features of Sick Building Syndrome and is an important problem in current building industry. In many cases it is caused by the rising moisture of building envelopes surface and exaggerated humidity of indoor air. Concerning historical buildings it is mostly caused by outdated raising techniques among that is absence of horizontal isolation against moisture and hygroscopic materials applied for construction. Recent buildings also suffer problem of mold risk which is caused in many cases by hermetization leading to improper performance of gravitational ventilation systems that make suitable conditions for mold development. Basing on our research there is proposed a method of buildings mold threat classification using electronic nose, based on a gas sensors array which consists of MOS sensors (metal oxide semiconductor). Used device is frequently applied for air quality assessment in environmental engineering branches. Presented results show the interpretation of e-nose readouts of indoor air sampled in rooms threatened with mold development in comparison with clean reference rooms and synthetic air. Obtained multivariate data were processed, visualized and classified using a PCA (Principal Component Analysis) and ANN (Artificial Neural Network) methods. Described investigation confirmed that electronic nose - gas sensors array supported with data processing enables to classify air samples taken from different rooms affected with mold.

  8. Evolution of Surface Texture and Cracks During Injection Molding of Fiber-Reinforced, Additively-Manufactured, Injection Molding Inserts

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Mischkot, Michael; Pedersen, David Bue

    2016-01-01

    This paper investigates the lifetime and surfacedeterioration of additively-manufactured, injection-moulding inserts. The inserts were produced using digital light processing and were reinforcedwith oriented short carbon fibers. Theinserts were used during injection molding oflow-density polyethy......This paper investigates the lifetime and surfacedeterioration of additively-manufactured, injection-moulding inserts. The inserts were produced using digital light processing and were reinforcedwith oriented short carbon fibers. Theinserts were used during injection molding oflow......-density polyethylene until their failure. The molded products were used to analyse the development of the surface roughness and wear. By enhancing the lifetime of injection-molding inserts,this work contributes to the establishment of additively manufactured inserts in pilot production....

  9. Simulation of Injection Molding Process Including Mold Filling and Compound Curing

    Directory of Open Access Journals (Sweden)

    Mohamad Reza Erfanian

    2012-12-01

    Full Text Available The present work reports and discusses the results of a 3D simulation of the injection molding process of a rubber compound that includes the mold flling stage and  material curing, using the computer code is developed in “UDF” part of the Fluent 6.3 CAE software. The data obtained from a rheometer (MDR 2000 is used to characterize the rubber material in order to fnd the cure model parameters which exist in curing model. Because of non-newtonian behavior of rubber, in this work the non-newtonian model for viscosity was used and viscosity parameters were computed by mean of viscometry test by RPA. After calculation of the physical and curing properties, vulcanization process was simulated for a complex rubber article with non-uniform thickness by solving the continuity, momentum, energy and curing process equations. Predicted flling and curing time in a complex and 3D rubber part is compared with experimentally measured data which confrmed  the accuracy and applicability of the method.

  10. Characteristics and infl uence factors of mold fi lling process in permanent mold with a slot gating system

    Directory of Open Access Journals (Sweden)

    Chen Changjun

    2009-11-01

    Full Text Available The main problems caused by improper gating are entrained aluminum oxide fi lms and entrapped gas. In this study, the slot gating system is employed to improve mold fi lling behavior and therefore, to improve the quality of aluminum castings produced in permanent molds. An equipment as well as operation procedures for real-time X-ray radiography of molten aluminum fl owing into permanent molds have been developed. Graphite molds transparent to X-rays are utilized which make it possible to observe the fl ow pattern through a number of vertically oriented gating systems. The investigation discovers that there are many infl uencing factors on the mold fi lling process. This paper focuses its research on some of the factors, such as the dimensions of the vertical riser and slot thickness, as well as roughness of the coating layer. The results indicate that molten metal can smoothly fi ll into casting cavity with a proper slot gating system. A bigger vertical riser, proper slot thickness and rougher coating can provide not only a better mold fi lling pattern, but also hot melt into the top of the cavity. A proper temperature gradient is obtainable, higher at the bottom and lower at the top of the casting cavity, which is in favor of feeding during casting solidifi cation.

  11. Stochastic cycle selection in active flow networks

    Science.gov (United States)

    Woodhouse, Francis; Forrow, Aden; Fawcett, Joanna; Dunkel, Jorn

    2016-11-01

    Active biological flow networks pervade nature and span a wide range of scales, from arterial blood vessels and bronchial mucus transport in humans to bacterial flow through porous media or plasmodial shuttle streaming in slime molds. Despite their ubiquity, little is known about the self-organization principles that govern flow statistics in such non-equilibrium networks. By connecting concepts from lattice field theory, graph theory and transition rate theory, we show how topology controls dynamics in a generic model for actively driven flow on a network. Through theoretical and numerical analysis we identify symmetry-based rules to classify and predict the selection statistics of complex flow cycles from the network topology. Our conceptual framework is applicable to a broad class of biological and non-biological far-from-equilibrium networks, including actively controlled information flows, and establishes a new correspondence between active flow networks and generalized ice-type models.

  12. Development of a Myxomycete Photoguide as a Teaching Tool for Microbial Taxonomy

    Directory of Open Access Journals (Sweden)

    Sittie Aisha B. Macabago

    2012-02-01

    Full Text Available Recently, web-based identification guides have been developed to aid modern taxonomists in identifying organisms. Unfortunately, these guides can only be used wherever Internet access is available. Thus, these cannot often be brought directly to the field for quick and easy identification of any collected specimens. Since we believe that field experience is necessary for any students of biology or microbiology, we developed a photoguide on the myxomycetes we collected from Lubang Island, Occidental Mindoro, Philippines. This photoguide is intended to aid both classroom and laboratory learning of a specific group of eukaryotic microoganisms, the plasmodial slime molds or myxomycetes. It provides a quick visual aid in the identification of myxomycetes found in Lubang Island, but may also be present in any other terrestrial forest areas of the country and of the world.

  13. Computer Texture Mapping for Laser Texturing of Injection Mold

    Directory of Open Access Journals (Sweden)

    Yongquan Zhou

    2014-04-01

    Full Text Available Laser texturing is a relatively new multiprocess technique that has been used for machining 3D curved surfaces; it is more flexible and efficient to create decorative texture on 3D curved surfaces of injection molds so as to improve the surface quality and achieve cosmetic surface of molded plastic parts. In this paper, a novel method of laser texturing 3D curved surface based on 3-axis galvanometer scanning unit has been presented to prevent the texturing of injection mold surface from much distortion which is often caused by traditional texturing processes. The novel method has been based on the computer texture mapping technology which has been developed and presented. The developed texture mapping algorithm includes surface triangulation, notations, distortion measurement, control, and numerical method. An interface of computer texture mapping has been built to implement the algorithm of texture mapping approach to controlled distortion rate of 3D texture math model from 2D original texture applied to curvature surface. Through a case study of laser texturing of a high curvature surface of injection mold of a mice top case, it shows that the novel method of laser texturing meets the quality standard of laser texturing of injection mold.

  14. Molding 4.0 - The Economics of an Injection Molding As-a-Service Business Model

    DEFF Research Database (Denmark)

    Charalambis, Alessandro; Tonetti, Marco Alessandro; Tosello, Guido

    involved contributes to a hazy definition of the phenomenon. In this work, Industry 4.0 is analyzed by analyzing into its influence on the plastics industry, with a focus on the injection molding technology. A new business model for the plastic industry is proposed, which fosters closer cooperation......During the last few years, the term Industry 4.0 or The Fourth Industrial Revolution, made its appearance and spread across industries. While it is accepted that the term broadly refers to a set of recent innovations with potential to disrupt value and process chains, the heterogeneity of actors...... the paradigm of Industry 4.0 is able to disrupt the industry by decreasing machine downtime and offering remarkable improvements in machine up-time. The present research aims to highlighting some of the opportunities for the plastic industry enabled by the implementation of an Internet of Things architecture....

  15. Initial verification of an induction heating set-up for injection molding

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano

    2013-01-01

    Molding of thin and long parts by injection molding leads to special requirements for the mold in order to ensure proper filling and acceptable cycle time. This paper investigates the applicability of embedded induction heating for the improvement of the filling of thin long parts. The object...... selected for the investigation is a thin spiral. For the complete molding of the component, elevated mold temperatures are required. For this propose a new injection molding set-up was developed, which allows rapid heating of the cavity wall by an induction heating system. The temperature was measured...

  16. Development of the computer-aided process planning (CAPP system for polymer injection molds manufacturing

    Directory of Open Access Journals (Sweden)

    J. Tepić

    2011-10-01

    Full Text Available Beginning of production and selling of polymer products largely depends on mold manufacturing. The costs of mold manufacturing have significant share in the final price of a product. The best way to improve and rationalize polymer injection molds production process is by doing mold design automation and manufacturing process planning automation. This paper reviews development of a dedicated process planning system for manufacturing of the mold for injection molding, which integrates computer-aided design (CAD, computer-aided process planning (CAPP and computer-aided manufacturing (CAM technologies.

  17. Development of plastic pulley by injection molding; Shashutsu keisei ni yoru jushi pulley no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizumi, F; Funatsu, A; Yazawa, H [Sumitomo Bakelite Co. Ltd., Tokyo (Japan)

    1997-10-01

    We developed plastic pulley for automobile manufactured by injection molding which will reduce manufacturing cost. We have developed product design, injection molding technology especially to improve mechanical strength and phenolic molding compound with good wear resistance and high mechanical strength. We have established `Injection Compression molding` technology to improve mechanical strength of weld portion. We also developed phenolic molding compound which is composed of one step resin and long organic fiber to obtain good wear resistance and high mechanical strength. Manufacturing cost will be reduced by using injection molding combined with lower material cost of the newly developed compound. 12 figs., 2 tabs.

  18. Study on the flow of molten polymers in a mold an investigation on mold printability; Kobunshi yoyutai no kanagatanai bisho ryudo. Kanagata tenshasei no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Kano, Y.; Nishimura, T.; Ito, S. [Ube Industries Ltd. Yamaguchi (Japan)] Usui, H. [Kobe Univ. (Japan)] Saeki, T. [Yamaguchi Univ. (Japan)

    1998-09-15

    A visualization experiment was carried out using a small metal mold with rectangular grooves as a mold printable model to observe the micro-flow of molten polymer in a metal mold. The glitter, which is an index of printability, was correlated with blow velocity and space area. Since it is highly correlated with space area, it can be thought that filling up well the fine grooves of mold heighten the glitter and printability as well. The effect of such factors as mold temperature, polymer melt temperature, air blow pressure and air blow velocity on the mold printability was investigated. For high density polyethylene and polypropylene, the glitter depended the most on the mold temperature. The higher the temperature, the higher the glitter. It was also found that the increase in blow pressure was effective. For high density polyethylene, the effect of blow velocity and polymer melt temperature was also recognized. 3 refs., 6 figs., 3 tabs.

  19. Casting metal microstructures from a flexible and reusable mold

    International Nuclear Information System (INIS)

    Cannon, Andrew H; King, William P

    2009-01-01

    This paper describes casting-based microfabrication of metal microstructures and nanostructures. The metal was cast into flexible silicone molds which were themselves cast from microfabricated silicon templates. Microcasting is demonstrated in two metal alloys of melting temperature 70 °C or 138 °C. Many structures were successfully cast into the metal with excellent replication fidelity, including ridges with periodicity 400 nm and holes or pillars with diameter in the range 10–100 µm and aspect ratio up to 2:1. The flexibility of the silicone mold permits casting of curved surfaces, which we demonstrate by fabricating a cylindrical metal roller of diameter 8 mm covered with microstructures. The metal microstructures can be in turn used as a reusable molding tool

  20. Customized mold radiotherapy with prosthetic apparatus for oral cancers

    International Nuclear Information System (INIS)

    Noguchi, Tadahide; Tsuchiya, Yoshiyuki; Hayasaka, Junichi; Itoh, Hiroto; Jinbu, Yoshinori; Kusama, Mikio; Takahashi, Satoru; Nakazawa, Masanori

    2014-01-01

    Eight patients (6 males, 2 females; median age, 78 years; age range, 31-94 years) were treated by mold radiotherapy with a prosthetic apparatus for oral cancers between October 2006 and March 2013. The primary sites were the tongue in 3 cases, hard palate and buccal mucosa in 2 cases each, and oral floor in 1 case. The type of treatment consisted of radical radiotherapy and palliative radiotherapy in 2 cases each, and preoperative radiotherapy, postoperative radiotherapy, additional radiotherapy after external beam radiotherapy and systemic chemotherapy in 1 case each. Patients received 40-50 Gy in 8-10 fractions with mold radiotherapy. Two patients who received radical radiotherapy showed no signs of recurrence or metastasis. The present therapy contributed to patients' palliative, postoperative, and preoperative therapy. Mold radiotherapy with a prosthetic appliance was performed safely and was a useful treatment for several types of oral cancer. (author)

  1. Influence of melt mixer on injection molding of thermoset elastomers

    Science.gov (United States)

    Rochman, Arif; Zahra, Keith

    2016-10-01

    One of the drawbacks in injection molding is that the plasticizing screw is short such that polymers having high concentrations of additives, such as thermoset elastomers, might not mix homogeneously within the short period of time during the plasticizing stage. In this study, various melt mixers inside the nozzle chamber, together forming a mixing nozzle, were developed. Three different materials were investigated, namely nitrile butadiene rubber (NBR), ethylene propylene-diene monomer (EPDM) and fluorocarbon (FKM). The use of these melt mixers resulted in better homogeneity and properties of the molded parts despite a curing time reduction of 10 s. This was due to the increase in mixing and shearing introduced a higher rate of crosslinking formation in the molded parts.

  2. Long fiber polymer composite property calculation in injection molding simulation

    Science.gov (United States)

    Jin, Xiaoshi; Wang, Jin; Han, Sejin

    2013-05-01

    Long fiber filled polymer composite materials have attracted a great attention and usage in recent years. However, the injection and compression molded long fiber composite materials possess complex microstructures that include spatial variations in fiber orientation and length. This paper presents the recent implemented anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model for predicting fiber orientation distribution[1] and a newly developed fiber breakage model[2] for predicting fiber length distribution in injection and compression molding simulation, and Eshelby-Mori-Tanaka model[3,4] with fiber-matrix de-bonding model[5] have been implemented to calculate the long fiber composite property distribution with predicted fiber orientation and fiber length distributions. A validation study on fiber orientation, fiber breakage and mechanical property distributions are given with injection molding process simulation.

  3. Fabricating microfluidic valve master molds in SU-8 photoresist

    Science.gov (United States)

    Dy, Aaron J.; Cosmanescu, Alin; Sluka, James; Glazier, James A.; Stupack, Dwayne; Amarie, Dragos

    2014-05-01

    Multilayer soft lithography has become a powerful tool in analytical chemistry, biochemistry, material and life sciences, and medical research. Complex fluidic micro-circuits require reliable components that integrate easily into microchips. We introduce two novel approaches to master mold fabrication for constructing in-line micro-valves using SU-8. Our fabrication techniques enable robust and versatile integration of many lab-on-a-chip functions including filters, mixers, pumps, stream focusing and cell-culture chambers, with in-line valves. SU-8 created more robust valve master molds than the conventional positive photoresists used in multilayer soft lithography, but maintained the advantages of biocompatibility and rapid prototyping. As an example, we used valve master molds made of SU-8 to fabricate PDMS chips capable of precisely controlling beads or cells in solution.

  4. Injection molding of coarse 316L stainless steel powder

    International Nuclear Information System (INIS)

    Omar, M.A.; Abdullah, N.S.; Subuki, I; Ali, E.A.G.E.; Ismail, F.; Hassan, N.

    2007-01-01

    Metal injection molding (MIM) process using 316L stainless steel powder of 45 μm was investigated. The binder system consists of a major fraction of palm stearins and minor fraction of polyethylene with a powder loading of 65 vol. %. The rheological behaviour of the feedstock was determined using Capillary Rheometer. The feedstock then injected using vertical injection molding machine into the tensile test bar. Then molded parts were de bound and sintered in vacuum at temperature of 1360 degree Celsius. The results show that the viscosity of the feedstock decreased with the temperature increased. The best sintered density achieved was about 7.5 g/cm 3 with the tensile strength of more than 460 MPa. The properties of the sintered specimens could be increased with the increasing of sintering temperature. (author)

  5. Process and part filling control in micro injection molding

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Schoth, Andreas

    2008-01-01

    The influence of process parameters on μ-injection molding (μIM) and on μ-injection molded parts has been investigated using Design of Experiments. A mold with a sensor applied at injection location was used to monitor actual injection pressure and to determine the cavity filling time. Flow markers...... position was measured on the polymer μ-parts to evaluate filling behavior of the polymer melt flowing through μ-features. Experimental results obtained under different processing conditions were evaluated to correlate the process parameter levels influence on the selected responses. Results showed...... that the injection speed in one of the most influencing process parameters on the μIM process and on the μ-parts filling....

  6. Fabricating microfluidic valve master molds in SU-8 photoresist

    International Nuclear Information System (INIS)

    Dy, Aaron J; Cosmanescu, Alin; Sluka, James; Glazier, James A; Amarie, Dragos; Stupack, Dwayne

    2014-01-01

    Multilayer soft lithography has become a powerful tool in analytical chemistry, biochemistry, material and life sciences, and medical research. Complex fluidic micro-circuits require reliable components that integrate easily into microchips. We introduce two novel approaches to master mold fabrication for constructing in-line micro-valves using SU-8. Our fabrication techniques enable robust and versatile integration of many lab-on-a-chip functions including filters, mixers, pumps, stream focusing and cell-culture chambers, with in-line valves. SU-8 created more robust valve master molds than the conventional positive photoresists used in multilayer soft lithography, but maintained the advantages of biocompatibility and rapid prototyping. As an example, we used valve master molds made of SU-8 to fabricate PDMS chips capable of precisely controlling beads or cells in solution. (technical note)

  7. Decontamination formulation with additive for enhanced mold remediation

    Science.gov (United States)

    Tucker, Mark D [Albuquerque, NM; Irvine, Kevin [Huntsville, AL; Berger, Paul [Rome, NY; Comstock, Robert [Bel Air, MD

    2010-02-16

    Decontamination formulations with an additive for enhancing mold remediation. The formulations include a solubilizing agent (e.g., a cationic surfactant), a reactive compound (e.g., hydrogen peroxide), a carbonate or bicarbonate salt, a water-soluble bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate), a mold remediation enhancer containing Fe or Mn, and water. The concentration of Fe.sup.2+ or Mn.sup.2+ ions in the aqueous mixture is in the range of about 0.0001% to about 0.001%. The enhanced formulations can be delivered, for example, as a foam, spray, liquid, fog, mist, or aerosol for neutralization of chemical compounds, and for killing certain biological compounds or agents and mold spores, on contaminated surfaces and materials.

  8. Treatment principles for the management of mold infections.

    Science.gov (United States)

    Kontoyiannis, Dimitrios P; Lewis, Russell E

    2014-11-06

    Survival rates among immunocompromised patients with invasive mold infections have markedly improved over the last decade with earlier diagnosis and new antifungal treatment options. Yet, increasing antifungal resistance, breakthrough infections with intrinsically resistant fungi, and potentially life-threatening adverse effects and drug interactions are becoming more problematic, especially with prolonged therapy. Evidence-based recommendations for treating invasive aspergillosis and mucormycosis provide excellent guidance on the initial workup and treatment of these molds, but they cannot address all of the key management issues. Herein, we discuss 10 general treatment principles in the management of invasive mold disease in immunocompromised patients and discuss how these principles can be integrated to develop an effective, individualized treatment plan. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  9. Permanent Mold Casting of JIS-AC4C Aluminum Alloy Using a Low-Temperature Mold

    International Nuclear Information System (INIS)

    Yamagata, Hiroshi; Nikawa, Makoto

    2011-01-01

    Permanent mold casting using mold temperatures below 200 deg. C was conducted to obtain a high-strength, thin-walled casting. Al-7.36 mass% Si -0.18 Cu- 0.27Mg-0.34Fe alloy JIS-AC4C was cast using a bottom pouring cast plan. The product had a rectangular tube shape (70 mm W x 68 mm D x 180 mm H) with wall thicknesses of 1, 3 and 5 mm. The effect of heat insulation at the melt path was compared when using a sand runner insert and when using a steel runner insert as well as a powder mold release agent. Fine microstructures were observed in the casting. The smaller the thickness, the higher the hardness with smaller secondary dendrite arm spacing (SDAS). However, the hardness and the SDAS were unaffected by the mold temperature. It was proposed that the avoidance of the formation of primary α dendrite at the melt path generates a higher strength casting with adequate mold filling.

  10. The Effect of Epoxy Molding Compound Floor Life to Reliability Performance and mold ability for QFN Package

    Science.gov (United States)

    Peanpunga, Udom; Ugsornrat, Kessararat; Thorlor, Panakamol; Sumithpibul, Chalermsak

    2017-09-01

    This research studied about an epoxy molding compound (EMC) floor life to reliability performance of integrated circuit (IC) package. Molding is the process for protecting the die of IC package form mechanical and chemical reaction from external environment by shaping EMC. From normal manufacturing process, the EMC is stored in the frozen at 5oC and left at around room temperature for aging time or floor life before molding process. The EMC floor life effect to its properties and reliability performance of IC package. Therefore, this work interested in varied the floor life of EMC before molding process to analyze properties of EMC such as spiral flow length, gelation time, and viscosity. In experiment, the floor life of EMC was varied to check the effect of its property to reliability performance. The EMC floor life were varied from 0 hours to 60 hours with a step of 12 hours and observed wire sweep, incomplete EMC, and delamination inside the packages for 3x3, 5x5 and 8x8 mm2 of QFN packages. The evaluation showed about clearly effect of EMC floor life to IC packaging reliability. EMC floor life is not any concern for EMC property, moldabilty, and reliability from 0 hours to 48 hours for molding process of 3x3,5x5 and 8x8 mm2 QFN packaging manufacturing

  11. Use of the smart tongue to monitor mold growth and discriminate between four mold species grown in liquid media

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Guangying, E-mail: zhaogy-user@163.com [Food Safety Key Lab of Zhejiang Province, Department of Food Quality and Safety, Zhejiang Gongshang University, Hangzhou 310035 (China); Lin Xiaona; Dou Wenchao; Tian Shiyi; Deng Shaoping; Shi Jinqin [Food Safety Key Lab of Zhejiang Province, Department of Food Quality and Safety, Zhejiang Gongshang University, Hangzhou 310035 (China)

    2011-04-01

    A novel voltammetric electronic tongue, smart tongue, was employed to monitor the growth of mold and to differentiate between four types of mold grown in liquid medium. Principal component analysis (PCA) was used to extract the relevant information obtained by the smart tongue. Reference growth curves were based on measurements of dry weight and pH. The growth detected by the smart tongue was basically consistent with that observed by the measurement of dry weight and pH. The optimal combinations of electrodes and frequencies for monitoring growth were as follows: for Aspergillus, both the Pt and Au electrodes at 1 Hz, 10 Hz and 100 Hz; for Penicillium, the Pt and W electrodes at 100 Hz; for Mucor, the Pt, Pd and W electrodes at the three frequency segments; for Rhizopus, the Pd, Ti and Ag electrodes at the three frequency segments. The Ag electrode at 10 Hz or 100 Hz frequency could differentiate well between the four types of mold for culturing 6 h in the liquid media. Therefore, the smart tongue has a promising future as a modern rapid analytical technology for the real time detection of the growth of mold and for the classification model of mold.

  12. Use of the smart tongue to monitor mold growth and discriminate between four mold species grown in liquid media

    International Nuclear Information System (INIS)

    Zhao Guangying; Lin Xiaona; Dou Wenchao; Tian Shiyi; Deng Shaoping; Shi Jinqin

    2011-01-01

    A novel voltammetric electronic tongue, smart tongue, was employed to monitor the growth of mold and to differentiate between four types of mold grown in liquid medium. Principal component analysis (PCA) was used to extract the relevant information obtained by the smart tongue. Reference growth curves were based on measurements of dry weight and pH. The growth detected by the smart tongue was basically consistent with that observed by the measurement of dry weight and pH. The optimal combinations of electrodes and frequencies for monitoring growth were as follows: for Aspergillus, both the Pt and Au electrodes at 1 Hz, 10 Hz and 100 Hz; for Penicillium, the Pt and W electrodes at 100 Hz; for Mucor, the Pt, Pd and W electrodes at the three frequency segments; for Rhizopus, the Pd, Ti and Ag electrodes at the three frequency segments. The Ag electrode at 10 Hz or 100 Hz frequency could differentiate well between the four types of mold for culturing 6 h in the liquid media. Therefore, the smart tongue has a promising future as a modern rapid analytical technology for the real time detection of the growth of mold and for the classification model of mold.

  13. CT use for nasopharingeal molds realization in endocavitary brachytherapy

    International Nuclear Information System (INIS)

    Lopez, J. Torrecilla; Crispin, V.; Chust, M.; Guinot, J.; Arribas, L.; Mengual, J.; Carrasco, P.; Miragall, E.; Hernandez, A.; Guardino, C.; Carrascosa, M.; Cardenal, R.; Casana, M.; Prats, C.

    1996-01-01

    Purpose: We present the following procedure for the making of individual molds with dental silicone for endocavitary brachytherapy of nasopharingeal cancer aided by CT scan. Procedure: Head immobilization during the realization of nasopharynx CT. Planification of treatment using these CT images, to determine the optimum position of radioactive sources. Printing on paper CT images with the nasopharynx contoured walls and the radioactive sources position. Realization of the mold in plastiline with the aid of the cuts of printer paper cut out with the nasopharynx form. Obtaining of the negative of the mold of plastiline by means of the use of alginate. Placement of two number 20 rectal rigid catheters with metal malleable bars inside them, in order to give them an adequate form in relation to the previous carried out planning. Filling in of alginato negative, where rectal catheters were placed, with Provil MCD Bayer Dental, a silicone based material for precision impression. We recommend to crossing the catheters' end with a number 2 silk thread to secure the catheter. An end of the silk thread is left outside the mold in order to help the extraction at the end of application. We advise to carry out a neuroleptic anaesthesia for its insertion, for the purpose of achieving a soft palate suitable relaxation. It makes the insertion easier. Repeat CT with the mold and phantoms in position to know a definitive dose distribution calculation. Conclusion: This method avoids the necessity of general anaesthesia in the realization of individual molds of nasopharyx for endocavitary brachytherapy and it improves the implant dosimetry

  14. Infant origins of childhood asthma associated with specific molds.

    Science.gov (United States)

    Reponen, Tiina; Lockey, James; Bernstein, David I; Vesper, Stephen J; Levin, Linda; Khurana Hershey, Gurjit K; Zheng, Shu; Ryan, Patrick; Grinshpun, Sergey A; Villareal, Manuel; Lemasters, Grace

    2012-09-01

    The specific cause or causes of asthma development must be identified to prevent this disease. Our hypothesis was that specific mold exposures are associated with childhood asthma development. Infants were identified from birth certificates. Dust samples were collected from 289 homes when the infants were 8 months of age. Samples were analyzed for concentrations of 36 molds that comprise the Environmental Relative Moldiness Index (ERMI) and endotoxin, house dust mite, cat, dog, and cockroach allergens. Children were evaluated at age 7 years for asthma based on reported symptoms and objective measures of lung function. Host, environmental exposure, and home characteristics evaluated included a history of parental asthma, race, sex, upper and lower respiratory tract symptoms, season of birth, family income, cigarette smoke exposure, air conditioning, use of a dehumidifier, presence of carpeting, age of home, and visible mold at age 1 year and child's positive skin prick test response to aeroallergens and molds at age 7 years. Asthma was diagnosed in 24% of the children at age 7 years. A statistically significant increase in asthma risk at age 7 years was associated with high ERMI values in the child's home in infancy (adjusted relative risk for a 10-unit increase in ERMI value, 1.8; 95% CI, 1.5-2.2). The summation of levels of 3 mold species, Aspergillus ochraceus, Aspergillus unguis, and Penicillium variabile, was significantly associated with asthma (adjusted relative risk, 2.2; 95% CI, 1.8-2.7). In this birth cohort study exposure during infancy to 3 mold species common to water-damaged buildings was associated with childhood asthma at age 7 years. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  15. Applying dynamic mold temperature control to cosmetic package design

    Directory of Open Access Journals (Sweden)

    Hsiao Shih-Wen

    2017-01-01

    Full Text Available Owing to the fashion trend and the market needs, this study developed the eco-cushion compact. Through the product design and the advanced process technology, many issues have improved, for instance, the inconvenience of transportation, the lack of multiuse capability, the increase of costs, and the low yield rate. The eco-cushion compact developed in this study was high quality, low cost, and meets the requirements of the eco market. The study aimed at developing a reusable container. Dynamic mold temperature control was introduced in the injection modeling process. The innovation in the product was its multi-functional formula invention, eco-product design, one-piece powder case design, and multifunctional design in the big powder case, mold flow and development of dynamic mold temperature control. Finally, through 3D drawing and modeling, and computer assistance for mold flow and verification to develop and produce models. During the manufacturing process, in order to solve the problems of tightness and warping, development and manufacture of dynamic mold temperature control were introduced. This decreased the injection cycle and residual stress, and deformation of the products has reduced to less than 0.2 mm, and the air tightness increased. In addition, air leakage was less than 2% and the injection cycle decreased to at least 10%. The results of the study can be extended and applied on the future design on cosmetic package and an alternative can be proposed to solve the problems of air tightness and warping. In this study, dynamic mold temperature control is considered as a design with high price-performance ratio, which can be adopted on industrial application for practical benefit and improvement.

  16. Feasibility of using Big Area Additive Manufacturing to Directly Manufacture Boat Molds

    Energy Technology Data Exchange (ETDEWEB)

    Post, Brian K. [ORNL; Chesser, Phillip C. [ORNL; Lind, Randall F. [ORNL; Sallas, Matthew R. [ORNL; Love, Lonnie J. [ORNL

    2018-01-01

    The goal of this project was to explore the feasibility of using Big Area Additive Manufacturing (BAAM) to directly manufacture a boat mold without the need for coatings. All prior tooling projects with BAAM required the use to thick coatings to overcome the surface finish limitations of the BAAM process. While the BAAM process significantly lowers the cost of building the mold, the high cost element rapidly became the coatings (cost of the material, labor on coating, and finishing). As an example, the time and cost to manufacture the molds for the Wind Turbine project with TPI Composites Inc. and the molds for the submarine project with Carderock Naval Warfare Systems was a fraction of the time and cost of the coatings. For this project, a catamaran boat hull mold was designed, manufactured, and assembled with an additional 0.15” thickness of material on all mold surfaces. After printing, the mold was immediately machined and assembled. Alliance MG, LLC (AMG), the industry partner of this project, experimented with mold release agents on the carbon-fiber reinforced acrylonitrile butadiene styrene (CF ABS) to verify that the material can be directly used as a mold (rather than needing a coating). In addition, for large molds (such as the wind turbine mold with TPI Composites Inc.), the mold only provided the target surface. A steel subframe had to be manufactured to provide structural integrity. If successful, this will significantly reduce the time and cost necessary for manufacturing large resin infusion molds using the BAAM process.

  17. Injection molding tools with micro/nano-meter pattern

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to methods for embedded a micrometer and/or nanometer pattern into an injection molding tool. In a first main aspect, a micro/nanometer structured imprinting device is applied in, or on, an active surface so as to transfer the micro/nanometer patterned structure...... to the tool while the imprinting device is, at least partly, within a cavity of the injection molding tool. In a second main aspect, a base plate with a micro/nanometer structured pattern positioned on an upper part is positioned on the active surface within the tool, the lower part of the base plate facing...

  18. The study and fabrication of DLC micropattern on roll mold

    Science.gov (United States)

    Kwon, Young Woo; Lee, Tae Dong; Park, Yeong Min; Cho, Hyun; Kim, Jin Kon; Kim, Tae Gyu

    2015-03-01

    Diamond-like carbon (DLC) coating is becoming a promising protective coating layers due to its superior properties. In this study, instead of protective coating, DLC film was applied as the only component for micropattern then etched with lithography and lift-off process selectively. Furthermore, DLC film has been fabricated on aluminum roll mold. Then UV curing resin was applied to form the pattern on the polyethylene terephthalate (PET) film. The dimension and formation of the DLC micropattern on roll mold were analyzed. Moreover, the Raman spectroscopic of nitrogen-doped DLC film was analyzed.

  19. Tribologic analysis and technical innovation for rotary molding press

    International Nuclear Information System (INIS)

    Luo Wei; Bai Yumeng; Dai Xingjian

    2012-01-01

    The rotary molding press R53C-Y is the key facility in the compression molding working procedure of the nu clear fuel pellets. Its main compression assembly called the upper compression roller frame has been worn seriously during the production. At first, the mechanical model of the upper compression roller assembly was established for analysis and calculation physical strength. Then the wear causations of the upper compression roller frame were analyzed, and the existent problems of central lubrication system were discussed. Finally, Oil-air central lubrication system was designed considering the characteristic of nuclear fuel pellets production. (authors)

  20. Effect of Binder and Mold parameters on Collapsibility and Surface Finish of Gray Cast Iron No-bake Sand Molds

    Science.gov (United States)

    Srinivasulu Reddy, K.; Venkata Reddy, Vajrala; Mandava, Ravi Kumar

    2017-08-01

    Chemically bonded no-bake molds and cores have good mechanical properties and produce dimensionally accurate castings compared to green sand molds. Poor collapsibility property of CO2 hardened sodium silicate bonded sand mold and phenolic urethane no-bake (PUN) binder system, made the reclamation of the sands more important. In the present work fine silica sand is mixed with phenolic urethane no-bake binder and the sand sets in a very short time within few minutes. In this paper it is focused on optimizing the process parameters of PUN binder based sand castings for better collapsibility and surface finish of gray cast iron using Taguchi design. The findings were successfully verified through experiments.

  1. Study of the Effect of Mold Corner Shape on the Initial Solidification Behavior of Molten Steel Using Mold Simulator

    Science.gov (United States)

    Lyu, Peisheng; Wang, Wanlin; Long, Xukai; Zhang, Kaixuan; Gao, Erzhuo; Qin, Rongshan

    2018-02-01

    The chamfered mold with a typical corner shape (angle between the chamfered face and hot face is 45 deg) was applied to the mold simulator study in this paper, and the results were compared with the previous results from a well-developed right-angle mold simulator system. The results suggested that the designed chamfered structure would increase the thermal resistance and weaken the two-dimensional heat transfer around the mold corner, causing the homogeneity of the mold surface temperatures and heat fluxes. In addition, the chamfered structure can decrease the fluctuation of the steel level and the liquid slag flow around the meniscus at mold corner. The cooling intensities at different longitudinal sections of shell are close to each other due to the similar time-average solidification factors, which are 2.392 mm/s1/2 (section A-A: chamfered center), 2.372 mm/s1/2 (section B-B: 135 deg corner), and 2.380 mm/s1/2 (section D-D: face), respectively. For the same oscillation mark (OM), the heights of OM roots at different positions (profile L1 (face), profile L2 (135 deg corner), and profile L3 (chamfered center)) are very close to each other. The average value of height difference (HD) between two OMs roots for L1 and L2 is 0.22 mm, and for L2 and L3 is 0.38 mm. Finally, with the help of metallographic examination, the shapes of different hooks were also discussed.

  2. The reflectivity, wettability and scratch durability of microsurface features molded in the injection molding process using a dynamic tool tempering system

    Science.gov (United States)

    Kuhn, Sascha; Burr, August; Kübler, Michael; Deckert, Matthias; Bleesen, Christoph

    2011-02-01

    In this paper the replication qualities of periodically and randomly arranged micro-features molded in the injection molding process and their effects on surface properties are studied. The features are molded in PC, PMMA and PP at different mold wall temperatures in order to point out the necessity and profitability of a variotherm mold wall temperature control system. A one-dimensional heat conduction model is proposed to predict the cycle times of the variotherm injection molding processes. With regard to these processes, the molding results are compared to the molded surface feature heights using an atomic force microscope. In addition, the effects of the molded surface features on macroscopic surfaces are characterized in terms of light reflection using a spectrometer and in terms of water wettability by measuring the static contact angle. Furthermore, due to the sensitivity of the surface features on the molded parts, their durability is compared in a scratch test with a diamond tip. This leads to successful implementation in applications in which the optical appearance, in terms of gloss and reflection, and the water repellence, in terms of drag flow and adhesion, are of importance.

  3. The reflectivity, wettability and scratch durability of microsurface features molded in the injection molding process using a dynamic tool tempering system

    International Nuclear Information System (INIS)

    Kuhn, Sascha; Burr, August; Kübler, Michael; Deckert, Matthias; Bleesen, Christoph

    2011-01-01

    In this paper the replication qualities of periodically and randomly arranged micro-features molded in the injection molding process and their effects on surface properties are studied. The features are molded in PC, PMMA and PP at different mold wall temperatures in order to point out the necessity and profitability of a variotherm mold wall temperature control system. A one-dimensional heat conduction model is proposed to predict the cycle times of the variotherm injection molding processes. With regard to these processes, the molding results are compared to the molded surface feature heights using an atomic force microscope. In addition, the effects of the molded surface features on macroscopic surfaces are characterized in terms of light reflection using a spectrometer and in terms of water wettability by measuring the static contact angle. Furthermore, due to the sensitivity of the surface features on the molded parts, their durability is compared in a scratch test with a diamond tip. This leads to successful implementation in applications in which the optical appearance, in terms of gloss and reflection, and the water repellence, in terms of drag flow and adhesion, are of importance.

  4. Study on the performance of MoS2 modified PTFE composites by molding process

    Science.gov (United States)

    Ma, Weiqiang; Hou, Genliang; Bi, Song; Li, Ping; Li, Penghui

    2017-10-01

    MoS2 filled PTFE composites were prepared by cold pressing and sintering molding. The compressive and creep properties of composite materials were analyzed by controlling the size of molded composites during molding. The results show that the composites have the best compressive and creep resistance when the molding pressure is 55 MPa in the MoS2 composites with 15% mass fraction, which is a practical reference for the preparation of MoS2-modified PTFE composites.

  5. Manufacturability evaluation for molded parts using fictitious physical models, and its application in topology optimization

    OpenAIRE

    Sato, Yuki; Yamada, Takayuki; Izui, Kazuhiro; Nishiwaki, Shinji

    2017-01-01

    Manufacturing methods using molds, such as casting and injection molding, are widely used in industries. A basic requirement when using such manufacturing methods is that design engineers must design products so that they incorporate certain geometrical features that allow the mold parts to be removed from the created solid object. In the present study, we propose a manufacturability evaluation method especially adapted for the use of molds. To evaluate the manufacturability, we introduce fic...

  6. Comparison Of Simulation Results When Using Two Different Methods For Mold Creation In Moldflow Simulation

    Directory of Open Access Journals (Sweden)

    Kaushikbhai C. Parmar

    2017-04-01

    Full Text Available Simulation gives different results when using different methods for the same simulation. Autodesk Moldflow Simulation software provide two different facilities for creating mold for the simulation of injection molding process. Mold can be created inside the Moldflow or it can be imported as CAD file. The aim of this paper is to study the difference in the simulation results like mold temperature part temperature deflection in different direction time for the simulation and coolant temperature for this two different methods.

  7. Imprinted and injection-molded nano-structured optical surfaces

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Højlund-Nielsen, Emil; Clausen, Jeppe Sandvik

    2013-01-01

    . In this paper, nanostructured polymer surfaces suitable for up-scalable polymer replication methods, such as imprinting/embossing and injection-molding, are discussed. The limiting case of injection-moulding compatible designs is investigated. Anti-reflective polymer surfaces are realized by replication...

  8. Mechanical performance of injection molded polypropylene : characterization and modeling

    NARCIS (Netherlands)

    Erp, van T.B.; Govaert, L.E.; Peters, G.W.M.

    2013-01-01

    It is shown that predictions of local mechanical properties in a product can be made from the orientation only using an anisotropic viscoplastic model. Due to processing-induced crystalline orientations, the mechanical properties of injection-molded polymer products are anisotropic and exhibit

  9. 47 CFR 76.805 - Access to molding.

    Science.gov (United States)

    2010-10-01

    ... that there is sufficient space to permit the installation of the additional wiring without interfering... permit the installation of the new wiring without interfering with the ability of an existing MVPD to... CABLE TELEVISION SERVICE Cable Inside Wiring § 76.805 Access to molding. (a) An MVPD shall be permitted...

  10. Precision glass molding: Toward an optimal fabrication of optical lenses

    Science.gov (United States)

    Zhang, Liangchi; Liu, Weidong

    2017-03-01

    It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding (PGM) has thus been developed to realize an efficient manufacture of such optical components in a single step. However, PGM faces various technical challenges. For example, a PGM process must be carried out within the super-cooled region of optical glass above its glass transition temperature, in which the material has an unstable non-equilibrium structure. Within a narrow window of allowable temperature variation, the glass viscosity can change from 105 to 1012 Pas due to the kinetic fragility of the super-cooled liquid. This makes a PGM process sensitive to its molding temperature. In addition, because of the structural relaxation in this temperature window, the atomic structure that governs the material properties is strongly dependent on time and thermal history. Such complexity often leads to residual stresses and shape distortion in a lens molded, causing unexpected changes in density and refractive index. This review will discuss some of the central issues in PGM processes and provide a method based on a manufacturing chain consideration from mold material selection, property and deformation characterization of optical glass to process optimization. The realization of such optimization is a necessary step for the Industry 4.0 of PGM.

  11. Effective Control of Molds Using a Combination of Nanoparticles.

    Directory of Open Access Journals (Sweden)

    Ariana Auyeung

    Full Text Available Molds are filamentous fungi able to grow on a variety of surfaces, including constructed surfaces, food, rotten organic matter, and humid places. Mold growth is characterized by having an unpleasant odor in enclosed or non-ventilated places and a non-aesthetic appearance. They represent a health concern because of their ability to produce and release mycotoxins, compounds that are toxic to animals and humans. The aim of this study was to evaluate commercial nanoparticles (NPs that can be used as an additive in coatings and paints to effectively control the growth of harmful molds. Four different NPs were screened for their antifungal activities against the mycotoxin producing mold strains Aspergillus flavus and A. fumigatus. The minimal inhibitory concentrations of the NPs were determined in broth media, whereas an agar diffusion test was used to assess the antimold activity on acrylic- and water-based paints. The cytotoxic activity and the inflammatory response of the NPs were also evaluated using the established human derived macrophage cell line THP-1. Results showed that a combination of mix metallic- and ZnO-NPs (50:10 μg/mL effectively inhibited the fungal growth when exposed to fluorescent light. Neither cytotoxic effect nor inflammatory responses were recorded, suggesting that this combination can be safely used in humid or non-ventilated environments without any health concerns.

  12. Resin transfer molding for advanced composite primary aircraft structures

    Science.gov (United States)

    Markus, Alan; Palmer, Ray

    1991-01-01

    Resin Transfer Molding (RTM) has been identified by Douglas Aircraft Company (DAC) and industry to be one of the promising processes being developed today which can break the cost barrier of implementing composite primary structures into a commercial aircraft production environment. The RTM process developments and scale-up plans Douglas Aircrart will be conducting under the NASA ACT contract are discussed.

  13. Packing parameters effect on injection molding of polypropylene nanostructured surfaces

    DEFF Research Database (Denmark)

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

    2012-01-01

    having a diameter of 500 nm was employed. The tool insert surface was produced using chemical-based-batch techniques such aluminum anodization and nickel electroplating. During the injection molding process, polypropylene (PP) was employed as material and packing phase parameters (packing time, packing...

  14. influence of molding water content on shear strength characteristic

    African Journals Online (AJOL)

    eobe

    INFLUENCE OF MOLDING WATER CONTENT ON SHEAR STRENGTH OF COMPACTED CEMENT KILN DUST, K. J. Osinub. K. J. Osinub. K. J. Osinubi, et al. Nigerian Journal of Technology,. Vol. 34, No. 2, April 2015 267 pavements or as waste containment materials. Therefore, recent studies have been geared towards.

  15. Leach and mold resistance of essential oil metabolites

    Science.gov (United States)

    Carol A. Clausen; Vina W. Yang

    2011-01-01

    Purified primary metabolites from essential oils were previously shown to be bioactive inhibitors of mold fungi on unleached Southern pine sapwood, either alone or in synergy with a second metabolite. This study evaluated the leachability of these compounds in Southern pine that was either dip- or vacuum-treated. Following laboratory leach tests, specimens were...

  16. Stability of FDTS monolayer coating on aluminum injection molding tools

    International Nuclear Information System (INIS)

    Cech, Jiri; Taboryski, Rafael

    2012-01-01

    Highlights: ► We present novel and highly useful results on FDTS monolayer coating of aluminum. ► The coating is particularly applicable for coating of prototyping injection molding tools, which often are made of Al. ► We have demonstrated that the coating prevails in injection molding conditions and that the coating will prevent wear of the tools. - Abstract: We have characterized perfluorodecyltrichlorosilane (FDTS) molecular coating of aluminum molds for polymer replication via injection molding (IM). X-ray photoelectron spectroscopy (XPS) data, sessile drop contact angles with multiple fluids, surface energies and roughness data have been collected. Samples have been characterized immediately after coating, after more than 500 IM cycles to test durability, and after 7 months to test temporal stability. The coating was deposited in an affordable process, involving near room temperature gas phase reactions. XPS shows detectable fluorine presence on both freshly coated samples as well as on post-IM samples with estimated 30 at.% on freshly coated and 28 at.% on post-IM samples with more than 500 IM cycles with polystyrene (PS) and ABS polymer.

  17. Smart plastic functionalization by nanoimprint and injection molding

    DEFF Research Database (Denmark)

    Zalkovskij, Maksim; Thamdrup, Lasse Højlund; Smistrup, Kristian

    2015-01-01

    In this paper, we present a route for making smart functionalized plastic parts by injection molding with sub-micrometer surface structures. The method is based on combining planar processes well known and established within silicon micro and sub-micro fabrication with proven high resolution...

  18. Brief Guide to Mold, Moisture, and Your Home

    Science.gov (United States)

    ... Control is the Key to Mold Control When water leaks or spills occur indoors - act quickly . If wet ... version of this image . Renters: Report all plumbing leaks and ... In cases where persistent water problems are not addressed, you may want to ...

  19. Introducing cellulose nanocrystals in sheet molding compounds (SMC)

    Science.gov (United States)

    Amir Asadi; Mark Miller; Sanzida Sultana; Robert J. Moon; Kyriaki Kalaitzidou

    2016-01-01

    The mechanical properties of short glass fiber/epoxy composites containing cellulose nanocrystals (CNC) made using sheet molding compound (SMC) manufacturing method as well as the rheological and thermomechanical properties of the CNC-epoxy composites were investigated as a function of the CNC content. CNC up to 1.4 wt% were dispersed in the epoxy to produce the resin...

  20. Parylene C coating for high-performance replica molding.

    Science.gov (United States)

    Heyries, Kevin A; Hansen, Carl L

    2011-12-07

    This paper presents an improvement to the soft lithography fabrication process that uses chemical vapor deposition of poly(chloro-p-xylylene) (parylene C) to protect microfabricated masters and to improve the release of polymer devices following replica molding. Chemical vapor deposition creates nanometre thick conformal coatings of parylene C on silicon wafers having arrays of 30 μm high SU8 pillars with densities ranging from 278 to 10,040 features per mm(2) and aspect ratios (height : width) from 1 : 1 to 6 : 1. A single coating of parylene C was sufficient to permanently promote poly(dimethyl)siloxane (PDMS) mold release and to protect masters for an indefinite number of molding cycles. We also show that the improved release properties of parylene treated masters allow for fabrication with hard polymers, such as poly(urethane), that would otherwise not be compatible with SU8 on silicon masters. Parylene C provides a robust and high performance mold release coating for soft lithography microfabrication that extends the life of microfabricated masters and improves the achievable density and aspect ratio of replicated features.

  1. 40 CFR Appendix - Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC...

    Science.gov (United States)

    2010-07-01

    ... Limits for Open Molding, Centrifugal Casting, and SMC Manufacturing Operations Where the Standards Are..., Table 5 Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC... casting—CR/HS 3,4 A vent system that moves heated air through the mold 27 lb/ton. 8. Centrifugal casting...

  2. A rapid colorimetric assay for mold spore germination using XTT tetrazolium salt

    Science.gov (United States)

    Carol A. Clausen; Vina W. Yang

    2011-01-01

    Current laboratory test methods to measure efficacy of new mold inhibitors are time consuming, some require specialized test equipment and ratings are subjective. Rapid, simple quantitative assays to measure the efficacy of mold inhibitors are needed. A quantitative, colorimetric microassay was developed using XTT tetrazolium salt to metabolically assess mold spore...

  3. Applications of polyamide/cellulose fiber/wollastonite composites for microcellular injection molding

    Science.gov (United States)

    Herman Winata; Lih-Sheng Turng; Daniel F. Caulfield; Tom Kuster; Rick Spindler; Rod Jacobson

    2003-01-01

    In this study, a cellulose-fiber-reinforced Polyamide-6 (PA-6) composite, a hybrid composite (PA-6/cellulose/Wollastonite), and the neat PA-6 resin were injection molded into ASTM test–bar samples with conventional and microcellular injection molding. The impact and tensile strengths of molded samples were measured and the Scanning Electron Microscopy (SEM) images were...

  4. Temperature Dependence and Magnetic Properties of Injection Molding Tool Materials Used in Induction Heating

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Nielsen, Kaspar Kirstein; Hattel, Jesper Henri

    2015-01-01

    To analyze the heating phase of an induction heated injection molding tool precisely, the temperature-dependent magnetic properties, B–H curves, and the hysteresis loss are necessary for the molding tool materials. Hence, injection molding tool steels, core materials among other materials have...

  5. 75 FR 55340 - Recovery Fact Sheet 9580.100, Mold Remediation

    Science.gov (United States)

    2010-09-10

    ...] Recovery Fact Sheet 9580.100, Mold Remediation AGENCY: Federal Emergency Management Agency, DHS. ACTION... accepting comments on Recovery Fact Sheet RP9580.100, Mold Remediation. DATES: Comments must be received by... 20472-3100. II. Background The Recovery Fact Sheet RP9580.100, Mold Remediation, identifies the expenses...

  6. Dimensional accuracy of Acrylonitrile Butadiene Styrene injection molded parts produced in a pilot produc

    DEFF Research Database (Denmark)

    Mischkot, Michael; Davoudinejad, Ali; Charalambis, Alessandro

    of a geometry including micro-features have been injection-molded in Acrylonitrile Butadiene Styrene (ABS) with a single 20x20x2.5 mm^3 injection molding insert manufactured in a photopolymer composite material. This research investigates the dimensional accuracy of the injection molded parts as a function...

  7. Differential allergy induction by molds found in water-damaged homes**

    Science.gov (United States)

    Molds are ubiquitous in the environment and exposures to molds contribute to various human diseases including allergic lung diseases. The Institute of Medicine reports (NAS, 2004) and World Health Organization guidelines (WHO, 2009) concluded that the role of molds in asthma indu...

  8. Molding Properties of Inconel 718 Feedstocks Used in Low-Pressure Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Fouad Fareh

    2016-01-01

    Full Text Available The impact of binders and temperature on the rheological properties of feedstocks used in low-pressure powder injection molding was investigated. Experiments were conducted on different feedstock formulations obtained by mixing Inconel 718 powder with wax-based binder systems. The shear rate sensitivity index and the activation energy were used to study the degree of dependence of shear rate and temperature on the viscosity of the feedstocks. The injection performance of feedstocks was then evaluated using an analytical moldability model. The results indicated that the viscosity profiles of feedstocks depend significantly on the binder constituents, and the secondary binder constituents play an important role in the rheological behavior (pseudoplastic or near-Newtonian exhibited by the feedstock formulations. Viscosity values as low as 0.06 to 2.9 Pa·s were measured at high shear rates and high temperatures. The results indicate that a feedstock containing a surfactant agent exhibits the best moldability characteristics.

  9. Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable properties

    Science.gov (United States)

    Ellingham, Thomas; Kharbas, Hrishikesh; Manitiu, Mihai; Scholz, Guenter; Turng, Lih-Sheng

    2018-03-01

    A three-stage molding process involving microcellular injection molding with core retraction and an "out-of-mold" expansion was developed to manufacture thermoplastic polyurethane into lightweight foams of varying local densities, microstructures, and mechanical properties in the same microcellular injection molded part. Two stages of cavity expansion through sequential core retractions and a third expansion in a separate mold at an elevated temperature were carried out. The densities varied from 0.25 to 0.42 g/cm3 (77% to 62% weight reduction). The mechanical properties varied as well. Cyclic compressive strengths and hysteresis loss ratios, together with the microstructures, were characterized and reported.

  10. Design and Checking Analysis of Injection Mold for a Plastic Cup

    Science.gov (United States)

    Li, Xuebing

    2018-03-01

    A special injection mold was designed for the structural characteristics of a plastic cup part. The mold was simulated by Moldflow software and verified by calculating the stripping force, the pulling force and the clamping force of the mold so that to determine the appropriate injection parameters. It has been proved that the injection mold is effective and practical in the actual producing and can meet the quality requirements during the course of using it, which solved some problems for injection molding of this kind of parts and can provide some reference for the production of other products in the same industry.

  11. Measurement of casting parameters in ZnAlCu3 molds created by additive technology

    Directory of Open Access Journals (Sweden)

    S. Medić

    2016-10-01

    Full Text Available This paper examines the parameters of casting ZnAl4Cu3 alloy (volume, castability, density and occupancy of the mold in mold made additive technology. Molds made by additive technology are: cheaper in production of a small number of castings, geometrically more accurate and faster made. From obtained results of this paper it is clearly seen that printed mold must be protected with thermal coating because liquid adhesive of powder otherwise evaporates during casting and creates additional moisture in the mold, as it was noted.

  12. Characterization and process development for the selective removal of Sn, Sb, and As from anode slime obtained from electrolytic copper refining

    Directory of Open Access Journals (Sweden)

    Steinlechner S.

    2018-01-01

    Full Text Available The aim of this work was to develop a process for the removal of Sn, Sb and As from anode slime out of copper refinery to disburden a subsequent pyrometallurgical processing for precious metals refinement. For this reason, a detailed literature survey was conducted, followed by a characterization to find the present compounds/alloys and their morphology. A newly developed process concept for the separate extraction of the afore mentioned three target metals was developed and verified by leaching experiments, combined with thermodynamic calculations on their behavior under varying conditions. In this context, the influence of leaching temperature, alkalinity of leaching solution, and solid-liquid ration were evaluated on the extraction yields of Sn, As, and Sb, as well as how to exploit these findings to obtain separate streams enriched in the respective metals.

  13. Modeling and flow analysis of pure nylon polymer for injection molding process

    International Nuclear Information System (INIS)

    Nuruzzaman, D M; Kusaseh, N; Basri, S; Hamedon, Z; Oumer, A N

    2016-01-01

    In the production of complex plastic parts, injection molding is one of the most popular industrial processes. This paper addresses the modeling and analysis of the flow process of the nylon (polyamide) polymer for injection molding process. To determine the best molding conditions, a series of simulations are carried out using Autodesk Moldflow Insight software and the processing parameters are adjusted. This mold filling commercial software simulates the cavity filling pattern along with temperature and pressure distributions in the mold cavity. In the modeling, during the plastics flow inside the mold cavity, different flow parameters such as fill time, pressure, temperature, shear rate and warp at different locations in the cavity are analyzed. Overall, this Moldflow is able to perform a relatively sophisticated analysis of the flow process of pure nylon. Thus the prediction of the filling of a mold cavity is very important and it becomes useful before a nylon plastic part to be manufactured. (paper)

  14. Soft lithography of ceramic microparts using wettability-tunable poly(dimethylsiloxane) (PDMS) molds

    International Nuclear Information System (INIS)

    Su, Bo; Zhang, Aijun; Meng, Junhu; Zhang, Zhaozhu

    2016-01-01

    Green alumina microparts were fabricated from a high solid content aqueous suspension by microtransfer molding using air plasma-treated poly(dimethylsiloxane) (PDMS) molds. The wettability of the air plasma-treated PDMS molds spontaneously changed between the hydrophilic and hydrophobic states during the process. Initial hydrophilicity of the air plasma-treated PDMS molds significantly improved the flowability of the concentrated suspension. Subsequent hydrophobic recovery of the air plasma-treated PDMS molds enabled a perfect demolding of the green microparts. Consequently, defect-free microchannel parts of 60 μ m and a micromixer with an area of several square centimeters were successfully fabricated. In soft lithography, tuning the wetting behavior of PDMS molds has a great effect on the quality of ceramic microparts. Using wettability-tunable PDMS molds has great potential in producing complex-shaped and large-area ceramic microparts and micropatterns. (paper)

  15. Modeling and flow analysis of pure nylon polymer for injection molding process

    Science.gov (United States)

    Nuruzzaman, D. M.; Kusaseh, N.; Basri, S.; Oumer, A. N.; Hamedon, Z.

    2016-02-01

    In the production of complex plastic parts, injection molding is one of the most popular industrial processes. This paper addresses the modeling and analysis of the flow process of the nylon (polyamide) polymer for injection molding process. To determine the best molding conditions, a series of simulations are carried out using Autodesk Moldflow Insight software and the processing parameters are adjusted. This mold filling commercial software simulates the cavity filling pattern along with temperature and pressure distributions in the mold cavity. In the modeling, during the plastics flow inside the mold cavity, different flow parameters such as fill time, pressure, temperature, shear rate and warp at different locations in the cavity are analyzed. Overall, this Moldflow is able to perform a relatively sophisticated analysis of the flow process of pure nylon. Thus the prediction of the filling of a mold cavity is very important and it becomes useful before a nylon plastic part to be manufactured.

  16. Cavity air flow behavior during filling in microinjection molding

    DEFF Research Database (Denmark)

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

    2011-01-01

    Process monitoring of microinjection molding (μ-IM) is of crucial importance in understanding the effects of different parameter settings on the process, especially on its performance and consistency with regard to parts' quality. Quality factors related to mold cavity air evacuation can provide...... valuable information about the process dynamics and also about the filling of a cavity by a polymer melt. In this paper, a novel experimental setup is proposed to monitor maximum air flow and air flow work as an integral of the air flow over time by employing a microelectromechanical system gas sensor...... the effects of process parameters on cavity air evacuation, and the influence of air evacuation on the part flow length. © 2011 American Society of Mechanical Engineers....

  17. Fabrication of Complex Optical Components From Mold Design to Product

    CERN Document Server

    Riemer, Oltmann; Gläbe, Ralf

    2013-01-01

    High quality optical components for consumer products made of glass and plastic are mostly fabricated by replication. This highly developed production technology requires several consecutive, well-matched processing steps called a "process chain" covering all steps from mold design, advanced machining and coating of molds, up to the actual replication and final precision measurement of the quality of the optical components. Current market demands for leading edge optical applications require high precision and cost effective parts in large volumes. For meeting these demands it is necessary to develop high quality process chains and moreover, to crosslink all demands and interdependencies within these process chains. The Transregional Collaborative Research Center "Process chains for the replication of complex optical elements" at Bremen, Aachen and Stillwater worked extensively and thoroughly in this field from 2001 to 2012. This volume will present the latest scientific results for the complete process chain...

  18. Modeling of magnetic particle orientation in magnetic powder injection molding

    Science.gov (United States)

    Doo Jung, Im; Kang, Tae Gon; Seul Shin, Da; Park, Seong Jin

    2018-03-01

    The magnetic micro powder orientation under viscous shear flow has been analytically understood and characterized into a new analytical orientation model for a powder injection molding process. The effects of hydrodynamic force from the viscous flow, external magnetic force and internal dipole-dipole interaction were considered to predict the orientation under given process conditions. Comparative studies with a finite element method proved the calculation validity with a partial differential form of the model. The angular motion, agglomeration and magnetic chain formation have been simulated, which shows that the effect of dipole-dipole interaction among powders on the orientation state becomes negligible at a high Mason number condition and at a low λ condition (the ratio of external magnetic field strength and internal magnetic moment of powder). Our developed model can be very usefully employed in the process analysis and design of magnetic powder injection molding.

  19. Reusable molds for casting U-Zr alloys

    International Nuclear Information System (INIS)

    Chen, P.S.; Stevens, W.C.; Trybus, C.L.

    1992-09-01

    Refractory oxides, carbides, nitrides and sulfides were examined as mold coating materials for use in casting nuclear fuel. The molds require excellent high temperature chemical and mechanical stability combined with reasonable room temperature ductility to allow for fuel removal. Coatings were applied onto quartz and refractory metal coupons using various techniques. Sessile drop tests employing molten U-10%Zr (by weight) at 1550 degrees C were used to characterize coating performance. Results indicate that NbC, TiN, and Y 2 O 3 were non-wetting with U-10%Zr. However, only the Y 2 O 3 coating completely prevented adhesion of the fuel. The paper describes coating methods and details of the sessile drop experiments

  20. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    Energy Technology Data Exchange (ETDEWEB)

    M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

    2005-04-01

    Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  1. Pressureless sintering behavior of injection molded alumina ceramics

    Directory of Open Access Journals (Sweden)

    Liu W.

    2014-01-01

    Full Text Available The pressureless sintering behaviors of two widely used submicron alumina (MgOdoped and undoped with different solid loadings produced by injection molding have been studied systematically. Regardless of the sinterability of different powders depending on their inherent properties, solid loading plays a critical role on the sintering behavior of injection molded alumina, which greatly determines the densification and grain size, and leads to its full densification at low temperatures. As compared to the MgO-doped alumina powder, the undoped specimens exhibit a higher sinterability for its smaller particle size and larger surface area. While full densification could be achieved for MgO-doped powders with only a lower solid loading, due to the fact that MgO addition can reduce the detrimental effect of the large pore space on the pore-boundary separation.

  2. Microcellular injection-molding of polylactide with chain-extender

    International Nuclear Information System (INIS)

    Pilla, Srikanth; Kramschuster, Adam; Yang Liqiang; Lee, Junghoo; Gong Shaoqin; Turng, Lih-Sheng

    2009-01-01

    The effects of adding an epoxy-based chain-extender (CE) on the properties of injection-molded solid and microcellular polylactide (PLA) were studied. PLA and PLA with 8 wt.% CE (PLA-CE) were melt-compounded using a twin-screw extruder. Solid and microcellular specimens were produced via a conventional and microcellular injection-molding process, respectively. Various characterization techniques including gel permeation chromatography, tensile testing and dynamic mechanical analysis, scanning electron microscopy and differential scanning calorimetry were applied to study the molecular weight, static and dynamic mechanical properties, cell morphology, and crystallization behavior, respectively. The addition of CE enhanced the molecular weight but decreased the crystallinity of PLA. The addition of CE also reduced the cell size and increased the cell density. Furthermore, the decomposition temperatures and several tensile properties, including specific strength, specific toughness, and strain-at-break of both solid and microcellular PLA specimens, increased with the addition of CE.

  3. Occurrence of Foodborne Pathogens and Molds in Turkish Foods

    OpenAIRE

    Sebnem Ozturkogu-Budak

    2016-01-01

    A survey of the occurrence of food pathogens like Salmonella, Listeria, Escherichia, Clostridium, Bacillus and Staphylococcus analyses were performed on 301 food samples from 8 different food categories such as dry legumes, milk products, meat products, fish, frozen foods, deserts, nuts and vegetables and fruits. Yeast and mold analyses were also performed on 364 food products from 9 main food categories such as dry legumes, milk products, meat products, seasonings, deserts, nuts, bee product...

  4. Microstructural and mechanical characterization of injection molded 718 superalloy powders

    Energy Technology Data Exchange (ETDEWEB)

    Özgün, Özgür [Bingol University, Faculty of Engineering and Architecture, Mechanical Eng. Dep., 12000 Bingol (Turkey); Gülsoy, H. Özkan, E-mail: ogulsoy@marmara.edu.tr [Marmara University, Technology Faculty, Metallurgy and Materials Eng. Dep., 34722 Istanbul (Turkey); Yılmaz, Ramazan [Sakarya University, Technology Faculty, Metallurgy and Materials Eng. Dep., 54187 Sakarya (Turkey); Fındık, Fehim [Sakarya University, Technology Faculty, Metallurgy and Materials Eng. Dep., 54187 Sakarya (Turkey) and International University of Sarajevo, Faculty of Engineering and Natural Sciences, Department of Mechanical Engineering, 71000 Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegowina)

    2013-11-05

    Highlights: •Microstructural and mechanical properties of injection molded Nickel 718 superalloy were studied. •The maximum sintered density achieved this study was 97.3% at 1290 °C for 3 hours. •Tensile strength of 1022 MPa and elongation of 5.3% were achieved for sintered-heat treated samples. -- Abstract: This study concerns with the determination of optimum production parameters for injection molding 718 superalloy parts. And at the same time, microstructural and mechanical characterization of these produced parts was also carried out. At the initial stage, 718 superalloy powders were mixed with a multi-component binder system for preparing feedstock. Then the prepared feedstock was granulated and shaped by injection molding. Following this operation, the shaped samples were subjected to the debinding process. These samples were sintered at different temperatures for various times. Samples sintered under the condition that gave way to the highest relative density (3 h at 1290 °C) were solution treated and aged respectively. Sintered, solution treated and aged samples were separately subjected to microstructural and mechanical characterization. Microstructural characterization operations such as X-ray diffraction, optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and elemental analysis showed that using polymeric binder system led to plentiful carbide precipitates to be occurred in the injection molded samples. It is also observed that the volume fractions of the intermetallic phases (γ′ and γ″) obtained by aging treatment were decreased due to the plentiful carbide precipitation in the samples. Mechanical characterization was performed by hardness measurements and tensile tests.

  5. Dental Mold: A Novel Formulation to Treat Common Dental Disorders

    OpenAIRE

    Ghosh, Soma; Roy, Gopa; Mukherjee, Biswajit

    2009-01-01

    Oral administration of antibiotics to treat dental problems mostly yields slow actions due to slow onset and hepatic “first-pass.” Again, commonly used dental paints are generally washed out by saliva within few hours of application. To overcome the challenges, polymeric molds to be placed on an affected tooth (during carries and gum problems) were prepared and evaluated in vitro for sustained drug release for prolonged local action. Here, amoxicillin trihydrate and lidocaine hydrochloride we...

  6. The Antagonism Mechanism Of Trichoderma spp. Towards Fusarium solani Mold

    OpenAIRE

    Utami Sri Hastuti; Indriana Rahmawati

    2016-01-01

    The antagonism ability of seven Trichoderma isolates towards F.solani have been observed and tested by dual culture technique. The antagonism mechanism observed by microscopic observation with light microscope and Scanning Electron Microscopy (SEM). The research result showed seven species of Trichoderma molds have different antagonism ability towards F.solani each other. The antagonism mechanism observed by light microscope and Scanning Electron Microscopy were mycoparasitism, antibiosis, an...

  7. The Antagonism Mechanism Of Trichoderma spp. Towards Fusarium solani Mold

    Directory of Open Access Journals (Sweden)

    Utami Sri Hastuti

    2016-09-01

    Full Text Available The antagonism ability of seven Trichoderma isolates towards F.solani have been observed and tested by dual culture technique. The antagonism mechanism observed by microscopic observation with light microscope and Scanning Electron Microscopy (SEM. The research result showed seven species of Trichoderma molds have different antagonism ability towards F.solani each other. The antagonism mechanism observed by light microscope and Scanning Electron Microscopy were mycoparasitism, antibiosis, and competition.

  8. The design and improvement of radial tire molding machine

    Science.gov (United States)

    Wang, Wenhao; Zhang, Tao

    2018-04-01

    This paper presented that the high accuracy semisteel meridian tire molding machine structure configurations, combining tyre high precision characteristics, the original structure and parameter optimization, technology improvement innovation design period of opening and closing machine rotary shaping drum institutions. This way out of the shaft from the structure to the push-pull type movable shaping drum of thinking limit, compared with the specifications and shaping drum can smaller contraction, is conducive to forming the tire and reduce the tire deformation.

  9. A novel plastification agent for cemented carbides extrusion molding

    International Nuclear Information System (INIS)

    Ji-Cheng Zhou; Bai-Yun Huang

    2001-01-01

    A type of novel plastification agent for plasticizing powder extrusion molding of cemented carbides has been developed. By optimizing their formulation and fabrication method, the novel plastification agent, with excellent properties and uniform distribution characters, were manufactured. The thermal debinding mechanism has been studied, the extruding rheological characteristics and debinding behaviors have been investigated. Using the newly developed plastification agent, the cemented carbides extrusion rods, with diameter up to 25 mm, have been manufactured. (author)

  10. Occurrence of Foodborne Pathogens and Molds in Turkish Foods

    Directory of Open Access Journals (Sweden)

    Sebnem Ozturkogu-Budak

    2016-06-01

    Full Text Available A survey of the occurrence of food pathogens like Salmonella, Listeria, Escherichia, Clostridium, Bacillus and Staphylococcus analyses were performed on 301 food samples from 8 different food categories such as dry legumes, milk products, meat products, fish, frozen foods, deserts, nuts and vegetables and fruits. Yeast and mold analyses were also performed on 364 food products from 9 main food categories such as dry legumes, milk products, meat products, seasonings, deserts, nuts, bee products, bakery products and dried fruits produced in Turkey. S. aureus and Salmonella were the most prevalent (1.33% of the six isolated pathogens. The species Cl. perfringens, L. monocytogenes and B. cereus were detected with the ratios of 1.00%, 0.66% and 0.66%, respectively. Total yeast and molds occurrence were 1.65% and 9.06%, respectively. Pathogens were detected in cream cheese, spinach, strawberry and cod fish most prevalently, whereas dried fig, chilli pepper, hazelnut and bakery products were determined as foods prone to the growth of molds. The results of this study suggest that faecal contamination of water needs to be prevented, and the production and storage conditions of food materials should be improved. These findings have implications for the use of these surveillance data in developing evidence-based food policy.

  11. Fabrication of Microfluidic Valves Using a Hydrogel Molding Method.

    Science.gov (United States)

    Sugiura, Yusuke; Hirama, Hirotada; Torii, Toru

    2015-08-24

    In this paper, a method for fabricating a microfluidic valve made of polydimethylsiloxane (PDMS) using a rapid prototyping method for microchannels through hydrogel cast molding is discussed. Currently, the valves in microchannels play an important role in various microfluidic devices. The technology to prototype microfluidic valves rapidly is actively being developed. For the rapid prototyping of PDMS microchannels, a method that uses a hydrogel as the casting mold has been recently developed. This technique can be used to prepare a three-dimensional structure through simple and uncomplicated methods. In this study, we were able to fabricate microfluidic valves easily using this rapid prototyping method that utilizes hydrogel cast molding. In addition, we confirmed that the valve displacement could be predicted within a range of constant pressures. Moreover, because microfluidic valves fabricated using this method can be directly observed from a cross-sectional direction, we anticipate that this technology will significantly contribute to clarifying fluid behavior and other phenomena in microchannels and microfluidic valves with complex structures.

  12. Analysis of Meniscus Fluctuation in a Continuous Casting Slab Mold

    Science.gov (United States)

    Zhang, Kaitian; Liu, Jianhua; Cui, Heng; Xiao, Chao

    2018-03-01

    A water model of slab mold was established to analyze the microscopic and macroscopic fluctuation of meniscus. The fast Fourier transform and wavelet entropy were adopted to analyze the wave amplitude, frequency, and components of fluctuation. The flow patterns under the meniscus were measured by using particle image velocimetry measurement and then the mechanisms of meniscus fluctuation were discussed. The results reflected that wavelet entropy had multi-scale and statistical properties, and it was suitable for the study of meniscus fluctuation details both in time and frequency domain. The basic wave, frequency of which exceeding 1 Hz in the condition of no mold oscillation, was demonstrated in this work. In fact, three basic waves were found: long-wave with low frequency, middle-wave with middle frequency, and short-wave with high frequency. In addition, the upper roll flow in mold had significant effect on meniscus fluctuation. When the position of flow impinged was far from the meniscus, long-wave dominated the fluctuation and the stability of meniscus was enhanced. However, when the velocity of flow was increased, the short-wave dominated the meniscus fluctuation and the meniscus stability was decreased.

  13. Understanding the impact of molds on indoor air quality and possible links to health effects Indoor Molds - More than Just a Musty Smell

    Science.gov (United States)

    Molds are multi-celled, colony forming, eukaryotic microorganisms lacking chlorophyll belonging to the Kingdom Fungi. Furthermore, molds are ubiquitous in both indoor and outdoor environments. There are more than 200 different types of fungi to which people are routinely exposed ...

  14. Facile Fabrication of Animal-Specific Positioning Molds For Multi-modality Molecular Imaging

    International Nuclear Information System (INIS)

    Park, Jeong Chan; Oh, Ji Eun; Woo, Seung Tae

    2008-01-01

    Recently multi-modal imaging system has become widely adopted in molecular imaging. We tried to fabricate animal-specific positioning molds for PET/MR fusion imaging using easily available molding clay and rapid foam. The animal-specific positioning molds provide immobilization and reproducible positioning of small animal. Herein, we have compared fiber-based molding clay with rapid foam in fabricating the molds of experimental animal. The round bottomed-acrylic frame, which fitted into microPET gantry, was prepared at first. The experimental mice was anesthetized and placed on the mold for positioning. Rapid foam and fiber-based clay were used to fabricate the mold. In case of both rapid foam and the clay, the experimental animal needs to be pushed down smoothly into the mold for positioning. However, after the mouse was removed, the fabricated clay needed to be dried completely at 60 .deg. C in oven overnight for hardening. Four sealed pipe tips containing [ 18 F]FDG solution were used as fiduciary markers. After injection of [ 18 F]FDG via tail vein, microPET scanning was performed. Successively, MRI scanning was followed in the same animal. Animal-specific positioning molds were fabricated using rapid foam and fiber-based molding clay for multimodality imaging. Functional and anatomical images were obtained with microPET and MRI, respectively. The fused PET/MR images were obtained using freely available AMIDE program. Animal-specific molds were successfully prepared using easily available rapid foam, molding clay and disposable pipet tips. Thanks to animal-specific molds, fusion images of PET and MR were co-registered with negligible misalignment

  15. Analysis of Cavity Pressure and Warpage of Polyoxymethylene Thin Walled Injection Molded Parts: Experiments and Simulations

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Tosello, Guido; Hattel, Jesper Henri

    2014-01-01

    Process analysis and simulations on molding experiments of 3D thin shell parts have been conducted. Moldings were carried out with polyoxymethylene (POM). The moldings were performed with cavity pressure sensors in order to compare experimental process results with simulations. The warpage...... was characterized by measuring distances using a tactile coordinate measuring machine (CMM). Molding simulations have been executed taking into account actual processing conditions. Various aspects have been considered in the simulation: machine barrel geometry, injection speed profiles, cavity injection pressure......, melt and mold temperatures, material rheological and pvT characterization. Factors investigated for comparisons were: injection pressure profile, short shots length, flow pattern, and warpage. A reliable molding experimental database was obtained, accurate simulations were conducted and a number...

  16. Differentiation of Toxic Molds via Headspace SPME-GC/MS and Canine Detection

    Directory of Open Access Journals (Sweden)

    Kenneth G. Furton

    2007-08-01

    Full Text Available Indoor mold growth has recently become a concern in the legal world in regards to insurance litigation. Hazardous mold exposure to humans has been linked to many acute and chronic adverse health effects including death. As it grows, mold produces several types of primary and secondary metabolites, including microbial volatile organic compounds (MVOCs. Microbial volatile organic compound emission may be used as a preliminary indication of a mold infestation that is invisible to the unaided eye. The objective of the study is to identify the unique odor signatures of three species of molds, Aspergillus versicolor, Penicillium chrysogenum, and Stachybotrys chartarum by SPME-GC/MS analysis. Determining the compounds that are emitted by the selected species has made it possible to conduct validation studies of canine detection of these mold species through a series of field tests.

  17. Performance of U-Pu-Zr fuel cast into zirconium molds

    International Nuclear Information System (INIS)

    Crawford, D.C.; Lahm, C.E.; Tsai, H.

    1992-01-01

    Current fabrication techniques for the integral fast reactor (IFR) fuel utilize injection casting into quartz molds after reprocessing in the IFR fuel cycle facility. The quartz molds are destroyed during the fuel demolding process, and the quartz residue must therefore be treated as contaminated waste. Alternatively, if the fuel can be cast into molds that remain as part of the fuel slugs (i.e., if the fuel can be left inside the molds for irradiation), then the quartz mold contribution to the waste stream can be eliminated. This possibility is being addresssed in an ongoing effort to evaluate the irradiation performance of fuel cast into zirconium sheaths rather than quartz molds. Zirconium was chosen as the sheath material because it is the component of the U-Pu-Zr fuel alloy that raises the alloy solidus temperatures and provides resistance to fuel-cladding chemical interaction (FCCI)

  18. Flow visualization and simulation of the filling process during injection molding

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Tosello, Guido; Hattel, Jesper Henri

    2017-01-01

    To directly compare experimental moldings from an injection molding machine with simulations, a special mold has been produced with a glass window. The injection plane is perpendicular to the opening and closing planes, in order for the 55. mm thick glass window to be easily visible from the side....... These two had significant effects on the filling times and injection pressure calculated by the simulations. Other effects investigated included transient thermal management of the mold, pressure dependent viscosity and wall slip, but their effect were not remarkably large in this work. The obtained....... A high speed camera recording 500 frames per second was employed, and the mold had three thermocouples and two pressure sensors installed. The molded part is a 2. mm thick plate with a 0.5. mm thin section, which creates a characteristic V-shaped flow pattern. Two different materials were employed...

  19. Study on Type C Coal Fly ash as an Additive to Molding Sand for Steel Casting

    Science.gov (United States)

    Palaniappan, Jayanthi

    2017-04-01

    Study of physio-chemical properties studies such as granulometric analysis, moisture, X ray fluorescence etc. were performed with Type C coal—combustion fly ash to investigate their potential as a distinct option for molding sand in foundry, thereby reducing the dependency on latter. Technological properties study such as compressive strength, tensile strength, permeability and compaction of various compositions of fly ash molding sand (10, 20 and 30 % fly ash substitute to chemically bonded sand) were performed and compared with silica molding sand. Steel casting production using this fly ash molding sand was done and the casting surface finish and typical casting parameters were assessed. It was noted that a good quality steel casting could be produced using type C fly ash molding sand, which effectively replaced 20 % of traditional molding sand and binders thereby providing greater financial profits to the foundry and an effective way of fly ash utilization (waste management).

  20. IMPROVEMENT OF EQUIPMENT FOR EFFECTIVE HARDENING SAND MIXTURE BY VACUUM MOLDING

    Directory of Open Access Journals (Sweden)

    V. S. Doroshenko

    2016-01-01

    Full Text Available The review deals with the design flask tooling and patterns for effective hardening sand mixture in the vacuum molding (V-Process, and molding on a one-off patterns (Lost Foam Casting. Sealing and evacuating sand mixture – two major factors influence the strength of the casting mold and casting quality, management practices which will enable to improve the casting process.

  1. Mold prevention strategies and possible health effects in the aftermath of hurricanes and major floods.

    Science.gov (United States)

    Brandt, Mary; Brown, Clive; Burkhart, Joe; Burton, Nancy; Cox-Ganser, Jean; Damon, Scott; Falk, Henry; Fridkin, Scott; Garbe, Paul; McGeehin, Mike; Morgan, Juliette; Page, Elena; Rao, Carol; Redd, Stephen; Sinks, Tom; Trout, Douglas; Wallingford, Kenneth; Warnock, David; Weissman, David

    2006-06-09

    Extensive water damage after major hurricanes and floods increases the likelihood of mold contamination in buildings. This report provides information on how to limit exposure to mold and how to identify and prevent mold-related health effects. Where uncertainties in scientific knowledge exist, practical applications designed to be protective of a person's health are presented. Evidence is included about assessing exposure, clean-up and prevention, personal protective equipment, health effects, and public health strategies and recommendations. The recommendations assume that, in the aftermath of major hurricanes or floods, buildings wet for health effects in susceptible persons regardless of the type of mold or the extent of contamination. For the majority of persons, undisturbed mold is not a substantial health hazard. Mold is a greater hazard for persons with conditions such as impaired host defenses or mold allergies. To prevent exposure that could result in adverse health effects from disturbed mold, persons should 1) avoid areas where mold contamination is obvious; 2) use environmental controls; 3) use personal protective equipment; and 4) keep hands, skin, and clothing clean and free from mold-contaminated dust. Clinical evaluation of suspected mold-related illness should follow conventional clinical guidelines. In addition, in the aftermath of extensive flooding, health-care providers should be watchful for unusual mold-related diseases. The development of a public health surveillance strategy among persons repopulating areas after extensive flooding is recommended to assess potential health effects and the effectiveness of prevention efforts. Such a surveillance program will help CDC and state and local public health officials refine the guidelines for exposure avoidance, personal protection, and clean-up and assist health departments to identify unrecognized hazards.

  2. Determining the effects of thermal conductivity on epoxy molds using profiled cooling channels with metal inserts

    International Nuclear Information System (INIS)

    Altaf, Khurram; Rani, Abdul Ahmad Majdi; Ahmad, Faiz; Baharom, Masri; Raghavan, Vijay R.

    2016-01-01

    Polymer injection molds are generally manufactured with metallic materials, such as tool steel, which provide reliable working of molds and extended service life. The manufacture of injection molds with steel is a prolonged process because of the strength of steel. For a short prototype production run, one of the suitable choices could be the use of aluminum-filled epoxy material, which can produce a functional mold in a short time as compared with a conventionally machined tool. Aluminum-filled epoxy tooling is a good choice for short production runs for engineering applications, yet works best for relatively simple shapes. The advantages in relation to the fabrication of injection molds with epoxy-based materials include time saving in producing the mold, epoxy curing at ambient temperature, and ease of machining and post processing. Nevertheless, one major drawback of epoxy material is its poor thermal conductivity, which results in a relatively longer cooling time for epoxy injection molds. This study investigates some of the innovative ideas for enhancing the thermal conductivity for epoxy molds. The basic concept behind these ideas was to embed a highly thermally conductive metal insert within the mold between cavities with an innovative design of cooling channels called profiled cooling channels. This technique will increase the effective thermal conductivity of the epoxy mold, leading to the reduction in cooling time for the injection molded polymer part. Experimental analysis conducted in the current study also verified that the mold with profiled cooling channels and embedded metal insert has significantly reduced the cooling time

  3. Development of integrated control system for smart factory in the injection molding process

    Science.gov (United States)

    Chung, M. J.; Kim, C. Y.

    2018-03-01

    In this study, we proposed integrated control system for automation of injection molding process required for construction of smart factory. The injection molding process consists of heating, tool close, injection, cooling, tool open, and take-out. Take-out robot controller, image processing module, and process data acquisition interface module are developed and assembled to integrated control system. By adoption of integrated control system, the injection molding process can be simplified and the cost for construction of smart factory can be inexpensive.

  4. Selection of antifungal protein-producing molds from dry-cured meat products.

    Science.gov (United States)

    Acosta, Raquel; Rodríguez-Martín, Andrea; Martín, Alberto; Núñez, Félix; Asensio, Miguel A

    2009-09-30

    To control unwanted molds in dry-cured meats it is necessary to allow the fungal development essential for the desired characteristics of the final product. Molds producing antifungal proteins could be useful to prevent hazards due to the growth of mycotoxigenic molds. The objective has been to select Penicillium spp. that produce antifungal proteins against toxigenic molds. To obtain strains adapted to these products, molds were isolated from dry-cured ham. A first screening with 281 isolates by the radial inhibition assay revealed that 166 were active against some of the toxigenic P. echinulatum, P. commune, and Aspergillusniger used as reference molds. The activity of different extracts from cultured medium was evaluated by a microspectroscopic assay. Molds producing active chloroform extracts were eliminated from further consideration. A total of 16 Penicillium isolates were screened for antifungal activity from both cell-free media and the aqueous residues obtained after chloroform extraction. The cell-free media of 10 isolates that produced a strong inhibition of the three reference molds were fractionated by FPLC on a cationic column. For protein purification, the fractions of the three molds that showed high inhibitory activity were further chromatographed on a gel filtration column, and the subfractions containing the highest absorbance peaks were assayed against the most sensitive reference molds. One subfraction each from strains AS51D and RP42C from Penicilliumchrysogenum confirmed the inhibitory activity against the reference molds. SDS-PAGE revealed a single band from each subfraction, with estimated molecular masses of 37kDa for AS51D and 9kDa for RP42C. Although further characterisation is required, both these proteins and the producing strains can be of interest to control unwanted molds on foods.

  5. Determining the effects of thermal conductivity on epoxy molds using profiled cooling channels with metal inserts

    Energy Technology Data Exchange (ETDEWEB)

    Altaf, Khurram; Rani, Abdul Ahmad Majdi; Ahmad, Faiz; Baharom, Masri [Mechanical Engineering Dept., Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak (Malaysia); Raghavan, Vijay R. [OYL Manufacturing, Sungai Buloh (Malaysia)

    2016-11-15

    Polymer injection molds are generally manufactured with metallic materials, such as tool steel, which provide reliable working of molds and extended service life. The manufacture of injection molds with steel is a prolonged process because of the strength of steel. For a short prototype production run, one of the suitable choices could be the use of aluminum-filled epoxy material, which can produce a functional mold in a short time as compared with a conventionally machined tool. Aluminum-filled epoxy tooling is a good choice for short production runs for engineering applications, yet works best for relatively simple shapes. The advantages in relation to the fabrication of injection molds with epoxy-based materials include time saving in producing the mold, epoxy curing at ambient temperature, and ease of machining and post processing. Nevertheless, one major drawback of epoxy material is its poor thermal conductivity, which results in a relatively longer cooling time for epoxy injection molds. This study investigates some of the innovative ideas for enhancing the thermal conductivity for epoxy molds. The basic concept behind these ideas was to embed a highly thermally conductive metal insert within the mold between cavities with an innovative design of cooling channels called profiled cooling channels. This technique will increase the effective thermal conductivity of the epoxy mold, leading to the reduction in cooling time for the injection molded polymer part. Experimental analysis conducted in the current study also verified that the mold with profiled cooling channels and embedded metal insert has significantly reduced the cooling time.

  6. Gate Design in Injection Molding of Microfluidic Components Using Process Simulations

    DEFF Research Database (Denmark)

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

    2016-01-01

    Just as in conventional injection molding of plastics, process simulationsare an effective and interesting tool in the area of microinjection molding. They can be applied in order to optimize and assist the design of the microplastic part, the mold, and the actual process. Available simulation...... software is however actually made for macroscopic injection molding. By means of the correct implementation and careful modeling strategy though, it can also be applied to microplastic parts, as it is shown in the present work. Process simulations were applied to two microfluidic devices (amicrofluidic...

  7. Experimental Investigation of Comparative Process Capabilities of Metal and Ceramic Injection Molding for Precision Applications

    DEFF Research Database (Denmark)

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

    2016-01-01

    and discussion presented in the paper will be useful for thorough understanding of the MIM and CIM processes and to select the right material and process for the right application or even to combine metal and ceramic materials by molding to produce metal–ceramic hybrid components.......The purpose of this paper is to make a comparative study on the process capabilities of the two branches of the powder injection molding (PIM) process—metal injection molding (MIM) and ceramic injection molding (CIM), for high-end precision applications. The state-of-the-art literature does...

  8. Aerobiological study of pollen and mold in Seoul, Korea

    Directory of Open Access Journals (Sweden)

    Jae-Won Oh

    1998-01-01

    Full Text Available In a large number of allergic individuals, inhalant allergens are important causative and triggering agents in respiratory allergies. It is essential to survey the pollen and mold around the patient’s environment for the diagnosis and treatment of airborne allergy. Rotorod samplers were installed at well-ventilated places in seven collecting stations in Seoul, the capital of Korea, which has a population of 12 million. Airborne particles carrying allergens were collected daily from each station for 2 years (1 October 1995 to 30 September 1997. After being stained with Calberla’s fuchsin, they were identified, counted and recorded. The weather in Seoul was also recorded. Pollen was found from the middle of February through to the end of December. The peak date for pollen was 12 May (peak mean daily count: 701 grains/m3/day and for mold it was 23 June (peak mean daily count: 936 spores/m3/day. Alder, birch, pine, oak, maple, elm, juniper, willow, and gingko trees were prevalent during the tree season, lasting from the middle of February to late July. Then sagebrush, ragweed, Japanese hop, and pigweed followed during the weed season, which lasts from the middle of July to the end of December. In skin prick test results, house dust mite was the most common positive allergen in Seoul, followed by cockroach. Among the pollens, mugwort was the most common positive, followed by ragweed mix, alder, birch, and grasses mix. Among the molds, there were high counts of Cladosporium and Alternaria during the year, excluding January. Ascospore of Lepto-spheria was highest during the monsoon season.

  9. Ion channel recordings on an injection-molded polymer chip.

    Science.gov (United States)

    Tanzi, Simone; Matteucci, Marco; Christiansen, Thomas Lehrmann; Friis, Søren; Christensen, Mette Thylstrup; Garnaes, Joergen; Wilson, Sandra; Kutchinsky, Jonatan; Taboryski, Rafael

    2013-12-21

    In this paper, we demonstrate recordings of the ion channel activity across the cell membrane in a biological cell by employing the so-called patch clamping technique on an injection-molded polymer microfluidic device. The findings will allow direct recordings of ion channel activity to be made using the cheapest materials and production platform to date and with the potential for very high throughput. The employment of cornered apertures for cell capture allowed the fabrication of devices without through holes and via a scheme comprising master origination by dry etching in a silicon substrate, electroplating in nickel and injection molding of the final part. The most critical device parameters were identified as the length of the patching capillary and the very low surface roughness on the inside of the capillary. The cross-sectional shape of the orifice was found to be less critical, as both rectangular and semicircular profiles seemed to have almost the same ability to form tight seals with cells with negligible leak currents. The devices were functionally tested using human embryonic kidney cells expressing voltage-gated sodium channels (Nav1.7) and benchmarked against a commercial state-of-the-art system for automated ion channel recordings. These experiments considered current-voltage (IV) relationships for activation and inactivation of the Nav1.7 channels and their sensitivity to a local anesthetic, lidocaine. Both IVs and lidocaine dose-response curves obtained from the injection-molded polymer device were in good agreement with data obtained from the commercial system.

  10. Development of ion beam sputtering technology for mold and die

    International Nuclear Information System (INIS)

    Lee, Jaehyung; Park, J.; Lee, J.; Jil, J.; Yang, D.; Noh, Y.; You, B.; You, J.

    2003-06-01

    Ion beam sputtering technique, one of the surface modification techniques, is to reduce surface roughness of materials with selective detaching atoms and micro particles from the surface by bombarding energetic ions of a few to a few tens keV onto the materials surfaces. This technique can be applied for the surfaces that need to have sub micrometer surface roughness, and it has already been used by companies and/or Institute over the world. Although this is relatively high cost process, it has been widely demanded in the industries with developing the eco-friend equipment due to its high quality of products. In the domestic industry, it has been pointed out that the mechanical polishing technique for molds and dies is relatively expensive and does not produce the required surface roughness. Therefore, in this R and D, techniques obtained from the ion source and the ion beam irradiation techniques developed for the proton accelerator has been applied to polish the surface of molds and dies to solve the above-mentioned problems that take place during mechanical polishing. In case that ion beam polishing technique is used, we expect not only producing the high quality polished surfaces but also producing the economically valuable end-products. In this R and D project, we are aiming at establishing ion beam techniques for industrialization as well as mass production of low cost products with developing the economical instrumentation techniques. Also, as a result of this R and D it is expected that importing of precise molds and dies may be reduced and technical competitiveness will be enhanced

  11. Fiber-Based, Injection-Molded Optofluidic Systems

    DEFF Research Database (Denmark)

    Matteucci, Marco; Triches, Marco; Nava, Giovanni

    2015-01-01

    We present a method to fabricate polymer optofluidic systems by means of injection molding that allow the insertion of standard optical fibers. The chip fabrication and assembly methods produce large numbers of robust optofluidic systems that can be easily assembled and disposed of, yet allow...... out two types of experiments that benefit from the improved optical system: optical stretching of red blood cells (RBCs) and Raman spectroscopy of a solution loaded into a hollow core fiber. The advantages offered by the presented technology are intended to encourage the use of LoC technology...

  12. Metal Injection Molding (MIM) of NdFeB Magnets

    OpenAIRE

    Hartwig T.; Lopes L.; Wendhausen P.; Ünal N.

    2014-01-01

    Due to the increased and unstable prices for Rare Earth elements there are activities to develop alternative hard magnetic materials. Reducing the amount of material necessary to produce complex sintered NdFeB magnets can also help to reduce some of the supply problem. Metal Injection Molding (MIM) is able to produce near net shape parts and can reduce the amount of finishing to achieve final geometry. Although MIM of NdFeB has been patented and published fairly soon after the development of ...

  13. Stability of FDTS monolayer coating on aluminum injection molding tools

    DEFF Research Database (Denmark)

    Cech, Jiri; Taboryski, Rafael J.

    2012-01-01

    microns can obliterate small features. The nanoimprint lithography community extensively uses functional monolayer coatings on silicon/SiO2 lithographic stamps [7–11]. This treatment dramatically reduces stiction, and improves yield and quality of replicated nanostructures. Here we report on a fluorinated...... trichloro-silane based coating deposited on aluminum or its alloys by molecular vapor deposition. We have tested the stability of this coating in challenging conditions of injection molding, an environment with high shear stress from the molten polymer, pressures up to 200 MPa, temperatures up to 250 ◦C...

  14. Applications of thin carbon coatings and films in injection molding

    Science.gov (United States)

    Cabrera, Eusebio Duarte

    In this research, the technical feasibility of two novel applications of thin carbon coatings is demonstrated. The first application consists of using thin carbon coatings on molds for molding ultra-thin plastic parts (graphene coating with carbide bonding to the mold surface. The coating resulted in a significant decrease of surface friction and consequently easiness of flow when compared to their uncoated counterparts. Thermoplastic polymers and their composites are a very attractive alternative but are hindered by the non-conductive nature of polymers. There are two general approaches used to date to achieve EMI shielding for plastic products. One is to spray a conductive metal coating onto the plastic surface forming a layer that must maintain its shielding effectiveness (SE), and its adhesion to the plastic throughout the expected life of the product. However, metal coatings add undesirable weight and tend to corrode over time. Furthermore, scratching the coating may create shielding failure; therefore, a protective topcoat may be required. The other approach is to use polymer composites filled with conductive fillers such as carbon black (CB), carbon nanofiber (CNF), and carbon nanotube (CNT). While conductive fillers may increase the electrical conductivity of polymer composites, the loading of such fillers often cannot reach a high level (painting using carbon black (CB). Such process can also be applied to injection molding for creating a top conductive layer. Increasing the amount of CB will increase the surface conductivity of the coated part, thus improving the paint transfer efficiency. However the CB levels needed to achieve the conductivity levels required for achieving EMI shielding would make the coating viscosity too large for proper coating. Nanopaper based composites are excellent candidates for EMI shielding because of the nanopaper's high concentration of carbon nanofibers (CNFs) (~2 wt% to 10 wt% depending on nanopaper/thermoplastic thickness

  15. The Influence of runner system on production of injection molds

    Directory of Open Access Journals (Sweden)

    Janostik Vaclav

    2016-01-01

    Full Text Available This experimental study describes the influence of runner system on rheological properties during the injection molding process. Economic effects on the amount of production are discussed as well. Autodesk Moldflow Synergy 2016 (Moldflow was used for the study of the injection process. Three suggestions of the runner system, cold runner system, hot runner system and the combination of cold–hot runner system have been promoted. These three variants underwent the rheological and economic analysis. As a result, recommendations for the application of the runner system for the required amount of production have been suggested

  16. Interim Report on Mixing During the Casting of LEU-10Mo Plates in the Triple Plate Molds

    Energy Technology Data Exchange (ETDEWEB)

    Aikin, Jr., Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-04-12

    LEU-10%Mo castings are commonly produced by down blending unalloyed HEU with a DU-12.7%Mo master-alloy. This work uses process modeling to provide insight into the mixing of the unalloyed uranium and U-Mo master alloy during melting and mold filling of a triple plate casting. Two different sets of situations are considered: (1) mixing during mold filling from a compositionally stratified crucible and (2) convective mixing of a compositionally stratified crucible during mold heating. The mold filling simulations are performed on the original Y-12 triple plate mold and the horizontal triple plate mold.

  17. Metal Injection Molding (MIM of Magnesium and Its Alloys

    Directory of Open Access Journals (Sweden)

    Martin Wolff

    2016-05-01

    Full Text Available Current research has highlighted that magnesium and its alloys as biodegradable material are highly suitable for biomedical applications. The new material fully degrades into nontoxic elements and offers material properties matching those of human bone tissue. As biomedical implants are rather small and complex in shape, the metal injection molding (MIM technique seems to be well suited for the near net shape mass production of such parts. Furthermore, MIM of Mg-alloys is of high interest in further technical fields. This study focusses on the performance of MIM-processing of magnesium alloy powders. It includes Mg-specific development of powder blending, feedstock preparation, injection molding, solvent and thermal debinding and final sintering. Even though Mg is a highly oxygen-affine material forming a stable oxide layer on each particle surface, the material can be sintered to nearly dense parts, providing mechanical properties matching those of as cast material. An ultimate tensile strength of 142 MPa, yield strength of 67 MPa, elastic modulus of 40 GPa and 8% elongation at fracture could be achieved using novel organic polymer binders for the feedstock preparation. Thus, first implant demonstrator parts could be successfully produced by the MIM technique.

  18. Moore's law and mold making: staying in the megapixel race

    Science.gov (United States)

    Renkema, Kor

    2007-09-01

    In this presentation an impression is given of technical developments within Philips High Tech Plastics, a European supplier with a production facility in Suzhou, China. Philips HTP is making precision plastic and optical parts for the mass consumer electronics market; the largest part of its current business is camera objective lenses and actuators for mobile phone. A supplier in consumer electronics has to deal with Moore's law, being one of the most specific characteristics of this particular market. This law says that every 18 - 24 months the performance of computers will double, while the price at the same performance will be halved, at the same rate. So this law also applies to lenses that are mounted on a silicon chip; the product life cycle is short, typical 2-3 years, and the next generation needs to have an ever-higher performance. The pixels are getting smaller and smaller, so the resolution of the lenses has to follow. This means a continuous tightening of the tolerances in mold making, molding and assembly, and the improvements are needed at a high rate. In the presentation is described what challenges in ever increasing precision are encountered, developments that are carried out to meet those, and in what extent Philips HTP is successful reaching the required goals.

  19. Finite Element Modeling of Reheat Stretch Blow Molding of PET

    Science.gov (United States)

    Krishnan, Dwarak; Dupaix, Rebecca B.

    2004-06-01

    Poly (ethylene terephthalate) or PET is a polymer used as a packaging material for consumer products such as beverages, food or other liquids, and in other applications including drawn fibers and stretched films. Key features that make it widely used are its transparency, dimensional stability, gas impermeability, impact resistance, and high stiffness and strength in certain preferential directions. These commercially useful properties arise from the fact that PET crystallizes upon deformation above the glass transition temperature. Additionally, this strain-induced crystallization causes the deformation behavior of PET to be highly sensitive to processing conditions. It is thus crucial for engineers to be able to predict its performance at various process temperatures, strain rates and strain states so as to optimize the manufacturing process. In addressing these issues; a finite element analysis of the reheat blow molding process with PET has been carried out using ABAQUS. The simulation employed a constitutive model for PET developed by Dupaix and Boyce et al.. The model includes the combined effects of molecular orientation and strain-induced crystallization on strain hardening when the material is deformed above the glass transition temperature. The simulated bottles were also compared with actual blow molded bottles to evaluate the validity of the simulation.

  20. Health symptoms caused by molds in a courthouse.

    Science.gov (United States)

    Lee, Tang G

    2003-07-01

    A majority of occupants of a newly renovated historic courthouse in Calgary, Alberta, Canada, reported multiple (3 or more) health-related symptoms, and several reported more than 10 persistent symptoms. Most required at least 1 day outside of the building to recover from their symptoms. Molds that produce mycotoxins, such as Stachybotrys chartarum and Emericella nidulans, were identified in the building, along with fungal organisms of the genera Aspergillus, Penicillium, Streptomyces, Cladosporium, Chaetomium, Rhizopus/Mucor, Alternaria, Ulocladium, and Basidiomycetes. Renovations to this historic had building failed to provide adequate thermal and vapor barriers, thus allowing moist indoor air to migrate into the building enclosure, causing condensation to develop. Mold grew on the condensation and was dispersed throughout the courthouse, including on furniture and files. The courthouse was closed and a new facility was modified with low-offgassing materials, better ventilation and air filtration, and strict building maintenance to accommodate those occupants of the older building who had developed multiple chemical sensitivities.

  1. Species identification, slime production and oxacillin susceptibility in coagulase-negative staphylococci isolated from nosocomial specimens Identificação de espécies, produção de "slime" e sensibilidade a oxacilina em amostras de Staphylococcus coagulase-negativo isoladas de espécimes nosocomiais

    Directory of Open Access Journals (Sweden)

    Lucía E. Alcaráz

    2003-04-01

    Full Text Available Ninety-two coagulase negative staphylococci (CNS (forty-five of clinical origin and forty-seven of environmental origin, collected in a hospital in San Luis, Argentina, from March to June, 1999, were identified to species level by the ID 32 Staph and API Staph System (bioMérieux. Slime production was investigated by the quantitative and qualitative methods. Oxacillin susceptibility was determined by the disk diffusion test (1 µg, the agar dilution method (0.125 to 4 mg/ml and agar screen (6 µg/ml. The presence of mecA gene was investigated by PCR. The clinical CNS species most commonly isolated were S. epidermidis, S. haemolyticus, S. hominis and S. saprophyticus. The frequency of slime production by clinical and environmental isolates was similar (25/45 and 27/47, respectively and the results obtained by the quantitative and the qualitative methods correlated well. The mecA gene was detected in all S. epidermidis, S. haemolyticus and S. hominis isolates, which were resistant to oxacillin by the phenotypic methods. However, this gene was not present in S. klossii, S. equorum, S. xylosus and S. capitis strains. The gene was neither found in two out of the six S. saprophyticus isolates, in two out of three S. cohnii subsp. urealyticum isolates and in two out of five S. cohnii subsp. cohnii isolates, all of which resulted oxacillin resistant according to MIC. The gene was not found in oxacillin-susceptible strains either. Most of the CNS isolates (enviromental and clinical that were slime producers were found to be oxacillin resistant, which makes the early detection of these microorganisms necessary to prevent their dissemination in hospitals, particularly among immunocompromised patients.Noventa e duas amostras de Staphylococcus coagulase negativo (SCN, (45 amostras clínicas e 47 ambientais, coletadas em um hospital de San Luis, Argentina, durante o período de março a junho de 1999, foram identificadas até espécies, empregando-se os

  2. A coupled model on fluid flow, heat transfer and solidification in continuous casting mold

    Directory of Open Access Journals (Sweden)

    Xu-bin Zhang

    2017-11-01

    Full Text Available Fluid flow, heat transfer and solidification of steel in the mold are so complex but crucial, determining the surface quality of the continuous casting slab. In the current study, a 2D numerical model was established by Fluent software to simulate the fluid flow, heat transfer and solidification of the steel in the mold. The VOF model and k-ε model were applied to simulate the flow field of the three phases (steel, slag and air, and solidification model was used to simulate the solidification process. The phenomena at the meniscus were also explored through interfacial tension between the liquid steel and slag as well as the mold oscillation. The model included a 20 mm thick mold to clarify the heat transfer and the temperature distribution of the mold. The simulation results show that the liquid steel flows as upper backflow and lower backflow in the mold, and that a small circulation forms at the meniscus. The liquid slag flows away from the corner at the meniscus or infiltrates into the gap between the mold and the shell with the mold oscillating at the negative strip stage or at the positive strip stage. The simulated pitch and the depth of oscillation marks approximate to the theoretical pitch and measured depth on the slab.

  3. 21 CFR 177.1900 - Urea-formaldehyde resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Urea-formaldehyde resins in molded articles. 177... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1900 Urea-formaldehyde resins in molded articles. Urea-formaldehyde resins may be safely used as the food-contact surface...

  4. All-in-polymer injection molded device for single cell capture using multilevel silicon master fabrication

    DEFF Research Database (Denmark)

    Tanzi, S.; Larsen, S.T.; Matteucci, M.

    2012-01-01

    This work demonstrates a novel all-in-polymer device for single cell capture applicable for biological recordings. The chip is injection molded and comprises a "cornered" (non planar) aperture. It has been demonstrated how cornered apertures are straightforward to mold in PDMS [1,2]. In this stud...

  5. Injection molded polymer chip for electrochemical and electrophysiological recordings from single cells

    DEFF Research Database (Denmark)

    Tanzi, Simone; Larsen, Simon Tylsgaard; Taboryski, Rafael J.

    We present a novel method to fabricate an all in polymer injection molded chip for electrochemical cell recordings and lateral cell trapping. The complete device is molded in thermoplastic polymer and it results from assembling two halves. We tested spin-coated conductive polymer poly(3,4-ethylen...

  6. Development of heat pipe technology for permanent mold casting of magnesium alloys

    International Nuclear Information System (INIS)

    Elalem, K.; Mucciardi, F.; Gruzleski, J.E.; Carbonneau, Y.

    2002-01-01

    One of the key techniques for producing sound permanent mold castings is to use controlled mold cooling such as air cooling, water cooling and heat pipe cooling. Air-cooling has limited applications in permanent mold casting due to its low cooling capability and high cost. Water-cooling is widely used in permanent mold casting, but has some disadvantages such as safety issues and the facilities required. The early applications of heat pipes in permanent mold casting have shown tremendous results due to their high cooling rates, low cost and safety. In this work, a permanent mold for magnesium casting has been designed with the intention of producing shrinkage defects in the castings. Novel heat pipes that can generate high cooling rates have been constructed and used to direct the solidification in order to reduce the shrinkage. In this paper, the design of the mold and that of the heat pipes are presented. The results of some of the computer simulations that were conducted to determine casting conditions along with the potential of using heat pipes to direct the solidification are also presented. Moreover, a preliminary evaluation of the performance of heat pipes in the permanent mold casting of magnesium will also be discussed. (author)

  7. Evolution of Additively Manufactured Injection Molding Inserts Investigated by Thermal Simulations

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Pedersen, David B.; Tosello, Guido

    Injection molding using inserts from vat polymerization, an additive manufacturing technology, has been investigated for pilot production and rapid prototyping purposes throughout the past years. A standard mold is equipped with additively manufactured inserts in a rectangular shape of (20 x 20 x 2...

  8. 49 CFR 173.221 - Polymeric beads, expandable and Plastic molding compound.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Polymeric beads, expandable and Plastic molding... Than Class 1 and Class 7 § 173.221 Polymeric beads, expandable and Plastic molding compound. (a) Non-bulk shipments of Polymeric beads (or granules), expandable, evolving flammable vapor and Plastic...

  9. Injection molding of nanopatterned surfaces in the sub-micrometer range with induction heating aid

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano

    2014-01-01

    . A tool insert having a surface containing functional geometries in the sub-micrometer range was produced using aluminum anodization and nickel electroplating. In order to provide elevated mold temperatures necessary for the complete replica of the pattern, a new mold setup was developed, which allows...

  10. Know your fibers : process and properties, or, a material science approach to designing pulp molded products

    Science.gov (United States)

    John F. Hunt

    1998-01-01

    The following results are preliminary, but show some basic information that will be used in an attempt to model pulp molded structures so that by measuring several basic fundamental properties of a fiber furnish and specifying process conditions, a molded structure could be designed for a particular performance need.

  11. NEW SOURCES OF GRAIN MOLD RESISTANCE AMONG SORGHUM ACCESSIONS FROM SUDAN

    Directory of Open Access Journals (Sweden)

    Louis Kajac Prom

    2009-05-01

    Full Text Available   Fifty-nine sorghum accessions from Sudan were evaluated in replicated plots at Isabela, Puerto Rico, for resistance against Fusarium thapsinum, one of the causal agents of grain mold.  The environmental conditions such as temperature, relative humidity, and rainfall during this study, especially at and after physiological maturity were optimal for grain mold development.  Highly significant negative correlations between grain mold severity ratings in the field and on threshed grains with germination rate and seed weight were recorded, indicating that germination and seed weight were adversely affected when challenged with F. thapsinum.  Temperature showed a significant negative correlation with grain mold severity and a significant positive correlation with germination rate.  However, no significant correlation was observed between rainfall and grain mold severity or germination rate.  Accessions PI570011, PI570027, PI569992, PI569882, PI571312, PI570759, and PI267548 exhibited the lowest grain mold severities and among the highest germination rates, indicating that these accessions may possess genetic resistance to grain mold and might be useful in sorghum enhancement programs.  Four of these accessions had significantly higher germination rates than the resistant control genotypes with PI267548 having the highest germination rate.  PI267548 was the only white seeded accessions showing significantly better grain mold resistance than the control genotypes.

  12. Injection molding of micro pillars on vertical side walls using polyether-ether-ketone (PEEK)

    DEFF Research Database (Denmark)

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

    2016-01-01

    This paper investigates the replication of microstructures on a vertical wall by PEEK injection molding. A 4-cavity insert was used in the injection molding. Pre-fabricated nickel plates with ø 4 μm micro holes on the surface were glued on vertical walls in the cavities. 3 cavities were coated by...

  13. Injection molded nanofluidic chips: Fabrication method and functional tests using single-molecule DNA experiments

    DEFF Research Database (Denmark)

    Utko, Pawel; Persson, Karl Fredrik; Kristensen, Anders

    2011-01-01

    We demonstrate that fabrication of nanofluidic systems can be greatly simplified by injection molding of polymers. We functionally test our devices by single-molecule DNA experiments in nanochannels.......We demonstrate that fabrication of nanofluidic systems can be greatly simplified by injection molding of polymers. We functionally test our devices by single-molecule DNA experiments in nanochannels....

  14. Fundamentals of mold growth in indoor environments and strategies for healthy living

    NARCIS (Netherlands)

    Adan, O.C.G.; Samson, R.A.

    2011-01-01

    Today, indoor mold and moisture, and their associated health effects, are a society-wide problem. The economic consequences of indoor mold and moisture are enormous. Their global dimension has been emphasized in several recent international publications, stressing that the most important means for

  15. Design and thermal analysis of a mold used in the injection of elastomers

    Science.gov (United States)

    Fekiri, Nasser; Canto, Cécile; Madec, Yannick; Mousseau, Pierre; Plot, Christophe; Sarda, Alain

    2017-10-01

    In the process of injection molding of elastomers, improving the energy efficiency of the tools is a current challenge for industry in terms of energy consumption, productivity and product quality. In the rubber industry, 20% of the energy consumed by capital goods comes from heating processes; more than 50% of heat losses are linked to insufficient control and thermal insulation of Molds. The design of the tooling evolves in particular towards the reduction of the heated mass and the thermal insulation of the molds. In this paper, we present a complex tool composed, on one hand, of a multi-cavity mold designed by reducing the heated mass and equipped with independent control zones placed closest to each molding cavity and, on the other hand, of a regulated channel block (RCB) which makes it possible to limit the waste of rubber during the injection. The originality of this tool lies in thermally isolating the regulated channel block from the mold and the cavities between them in order to better control the temperature field in the material which is transformed. We present the design and the instrumentation of the experimental set-up. Experimental measurements allow us to understand the thermal of the tool and to show the thermal heterogeneities on the surface of the mold and in the various cavities. Tests of injection molding of the rubber and a thermal balance on the energy consumption of the tool are carried out.

  16. Characterization methods of nano-patterned surfaces generated by induction heating assisted injection molding

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Ravn, Christian; Menotti, Stefano

    2015-01-01

    An induction heating-assisted injection molding (IHAIM) process developed by the authors is used to replicate surfaces containing random nano-patterns. The injection molding setup is developed so that an induction heating system rapidly heats the cavity wall at rates of up to 10◦C/s. In order...

  17. Effect of road deicing salt on the susceptibility of amphibian embryos to infection by water molds.

    Science.gov (United States)

    Karraker, Nancy E; Ruthig, Gregory R

    2009-01-01

    Some causative agents of amphibian declines act synergistically to impact individual amphibians and their populations. In particular, pathogenic water molds (aquatic oomycetes) interact with environmental stressors and increase mortality in amphibian embryos. We documented colonization of eggs of three amphibian species, the wood frog (Rana sylvatica), the green frog (Rana clamitans), and the spotted salamander (Ambystoma maculatum), by water molds in the field and examined the interactive effects of road deicing salt and water molds, two known sources of mortality for amphibian embryos, on two species, R. clamitans and A. maculatum in the laboratory. We found that exposure to water molds did not affect embryonic survivorship in either A. maculatum or R. clamitans, regardless of the concentration of road salt to which their eggs were exposed. Road salt decreased survivorship of A. maculatum, but not R. clamitans, and frequency of malformations increased significantly in both species at the highest salinity concentration. The lack of an effect of water molds on survival of embryos and no interaction between road salt and water molds indicates that observations of colonization of these eggs by water molds in the field probably represent a secondary invasion of unfertilized eggs or of embryos that had died of other causes. Given increasing salinization of freshwater habitats on several continents and the global distribution of water molds, our results suggest that some amphibian species may not be susceptible to the combined effects of these factors, permitting amphibian decline researchers to devote their attention to other potential causes.

  18. Differential Allergy Induction by Molds Found in Water-Damaged Homes

    Science.gov (United States)

    Abstract: We compared the allergy induction potential of high concentration molds found in water-damaged homes and molds found more universally to house dust mite (HDM) in our mouse allergy/asthma model. Female BALB/c mice received 1 or 4 exposures by intratracheal aspiration of ...

  19. Precision casting into disposable ceramic mold – a high efficiency method of production of castings of irregular shape

    OpenAIRE

    Уваров, Б. И.; Лущик, П. Е.; Андриц, А. А.; Долгий, Л. П.; Заблоцкий, А. В.

    2016-01-01

    The article shows the advantages and disadvantages of precision casting into disposable ceramic molds. The high quality shaped castings produced by modernized ceramic molding process are proved the reliability and prospects of this advanced technology.

  20. PRECISION CASTING INTO DISPOSABLE CERAMIC MOLD – A HIGH EFFICIENCY METHOD OF PRODUCTION OF CASTINGS OF IRREGULAR SHAPE

    Directory of Open Access Journals (Sweden)

    B. I. Uvarov

    2016-01-01

    Full Text Available The article shows the advantages and disadvantages of precision casting into disposable ceramic molds. The high quality shaped castings produced by modernized ceramic molding process are proved the reliability and prospects of this advanced technology.

  1. A study on compound contents for plastic injection molding products of metallic resin pigment

    International Nuclear Information System (INIS)

    Park, Young Whan; Kwak, Jae Seob; Lee, Gyu Sang

    2016-01-01

    Injection molding process is widely used for producing most plastic products. In order to make a metal-colored plastic product especially in modern luxury home alliances, metallic pigments which are mixed to a basic resin material for injection molding are available. However, the process control for the metal-colored plastic product is extremely difficult due to non-uniform melt flow of the metallic resin pigments. To improve the process efficiency, a rapid mold cooling method by a compressed cryogenic fluid and electricity mold are also proposed to decrease undesired compound contents within a molded plastic product. In this study, a quality of the metal-colored plastic product is evaluated with process parameters; injection speed, injection pressure, and pigment contents, and an influence of the rapid cooling and heating system is demonstrated

  2. Three-dimensional numerical modeling of an induction heated injection molding tool with flow visualization

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Tosello, Guido; Nielsen, Kaspar Kirstein

    2016-01-01

    , comparison of the induction heating and filling of the cavity is compared and validated with simulations. Two polymer materials ABS and HVPC were utilized during the injection molding experiments carried out in this work. A nonlinear electromagnetic model was employed to establish an effective linear......Using elevated mold temperature is known to have a positive influence of final injection molded parts. Induction heating is a method that allow obtaining a rapid thermal cycle, so the overall molding cycle time is not increased. In the present research work, an integrated multi-turn induction...... heating coil has been developed and assembled into an injection molding tool provided with a glass window, so the effect of induction heating can directly be captured by a high speed camera. In addition, thermocouples and pressure sensors are also installed, and together with the high speed videos...

  3. A novel vision-based mold monitoring system in an environment of intense vibration

    International Nuclear Information System (INIS)

    Hu, Fen; He, Zaixing; Zhao, Xinyue; Zhang, Shuyou

    2017-01-01

    Mold monitoring has been more and more widely used in the modern manufacturing industry, especially when based on machine vision, but these systems cannot meet the detection speed and accuracy requirements for mold monitoring because they must operate in environments that exhibit intense vibration during production. To ensure that the system runs accurately and efficiently, we propose a new descriptor that combines the geometric relationship-based global context feature and the local scale-invariant feature transform for the image registration step of the mold monitoring system. The experimental results of four types of molds showed that the detection accuracy of the mold monitoring system is improved in the environment with intense vibration. (paper)

  4. A novel vision-based mold monitoring system in an environment of intense vibration

    Science.gov (United States)

    Hu, Fen; He, Zaixing; Zhao, Xinyue; Zhang, Shuyou

    2017-10-01

    Mold monitoring has been more and more widely used in the modern manufacturing industry, especially when based on machine vision, but these systems cannot meet the detection speed and accuracy requirements for mold monitoring because they must operate in environments that exhibit intense vibration during production. To ensure that the system runs accurately and efficiently, we propose a new descriptor that combines the geometric relationship-based global context feature and the local scale-invariant feature transform for the image registration step of the mold monitoring system. The experimental results of four types of molds showed that the detection accuracy of the mold monitoring system is improved in the environment with intense vibration.

  5. Computer Aided Design of The Cooling System for Plastic Injection Molds

    Directory of Open Access Journals (Sweden)

    Hakan GÜRÜN

    2009-02-01

    Full Text Available The design of plastic injection molds and their cooling systems affect both the dimension, the shape, the quality of a plastic part and the cycle time of process and the cost of mold. In this study, the solid model design of a plastic injection mold and the design of cooling sysytem were possibly carried out without the designer interaction. Developed program permited the use of three types of the cooling system and the different cavity orientations and the multible plastic part placement into the mold cores. The program which was developed by using Visual LISP language and the VBA (Visual BASIC for Application modules, was applicated in the AutoCAD software domain. Trial studies were presented that the solid model design of plastic injection molds and the cooling systems increased the reliability, the flexibility and the speed of the design.

  6. Tool application CAD / CAM for design and construction of a prototype of plastic injection mold

    Directory of Open Access Journals (Sweden)

    Albert Miyer Suárez Castrillón

    2015-11-01

    Full Text Available The study, development and production of injection molds comes with the implementation of CAD and CAM tools available on the market; using these tools, a prototype injection mold for thermoplastic materials was designed and built, based on a mold is injection in the laboratory of the University of Pamplona, in which a couple of modifications were made in order to experiment with its design. The prototype was manufactured through a 3D scan of the original mold to provide the CAD / CAM files with the simulated 3D printing technique for performing an experimental study with the prototype for adjusting temperature and pressure sensors and for coatings metallic materials for use in the injection molding process.

  7. Micro Injection Molding of Thin Walled Geometries with Induction Heating System

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano

    2014-01-01

    To eliminate defects and improve the quality of molded parts, increasing the mold temperature is one of the applicable solutions. A high mold temperature can increase the path flow of the polymer inside the cavity allowing reduction of the number of injection points, reduction of part thickness...... and moulding of smaller and more complex geometries. The last two aspects are very important in micro injection molding. In this paper a new embedded induction heating system is proposed and validated. An experimental investigation was performed based on a test geometry integrating different aspect ratios...... of small structures. ABS was used as material and different combinations of injection velocity, pressure and mold temperature were tested. The replicated test objects were measured by means of an optical CMM machine. On the basis of the experimental investigation the efficacy of the embedded induction...

  8. Effect of Residence Time of Graphitisation on Thermal Conductivity of Molded Graphite

    Directory of Open Access Journals (Sweden)

    Pedy Artsanti

    2010-06-01

    Full Text Available The effect of residence time of graphitisation on thermal conductivity of molded graphite has been examined. The examination has been conducted by varying residence time of graphitisation of molded carbon with petroleum coke as raw material and coal tar pitch. Graphitisation has been conducted by heating molded graphite at 2500 °C in argon atmosphere with residention time of 10, 30 and 90 minutes. Graphitisation degree, density, shrinking mass and porosity of molded graphite were examined and so was its thermal conductivity. The result showed that the decrease of porosity and the increase of graphitisation degree due to the increasing of residention time of graphitisation will increase the thermal conductivity of graphite. Molded graphite graphitisized with residence time for 90 minutes residention time gave thermal conductivity of 2.134 Watt/mK and graphitization degree 0.718.

  9. A study on compound contents for plastic injection molding products of metallic resin pigment

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Whan; Kwak, Jae Seob [Dept. of Mechanical Engineering, Pukyong National University, Busan (Korea, Republic of); Lee, Gyu Sang [Alliance Molding Engineering TeamLG Electronics Inc., Osan (Korea, Republic of)

    2016-12-15

    Injection molding process is widely used for producing most plastic products. In order to make a metal-colored plastic product especially in modern luxury home alliances, metallic pigments which are mixed to a basic resin material for injection molding are available. However, the process control for the metal-colored plastic product is extremely difficult due to non-uniform melt flow of the metallic resin pigments. To improve the process efficiency, a rapid mold cooling method by a compressed cryogenic fluid and electricity mold are also proposed to decrease undesired compound contents within a molded plastic product. In this study, a quality of the metal-colored plastic product is evaluated with process parameters; injection speed, injection pressure, and pigment contents, and an influence of the rapid cooling and heating system is demonstrated.

  10. Molds contamination of raw milk and dairy products: Occurrence, diversity and contamination source

    Directory of Open Access Journals (Sweden)

    T Moshtaghi Maleki

    2015-11-01

    Full Text Available This study aimed to assess the occurrence and diversity of mold species in raw milk and its products along with the identification of potential contamination sources. For this reason, a total of 260 samples consisting of 80 raw milk, 100 dairy products (i.e., pasteurized milk, yoghurt, cheese and buttermilk and 80 environmental (i.e. ingredients, packaging materials, surface of processing equipments and air specimens were collected. Using culture assay and microscopic observation, the occurrence as well as the diversity of mold species was investigated. According to the results, 82.3% of the samples were identified as positive for mold contamination. The percentage of mold contamination for raw milk was estimated as 97.5%. In the case of pasteurized milk, yoghurt, buttermilk, cheese and environmental samples, it was determined as 52%, 76%, 52%, 56% and 96.25%, respectively. Mold diversity among various samples consisted of Aspergillus, Geotrichum, Penicillium, Mucor, Alternaria, Rhizopus, Stemphylium, Cladosporium, and Fusarium. Results revealed a significant (p < 0.01 correlation between kind of mold species isolated from raw milk and dairy products. Similarly, a correlation was observed between dairy products and environmental sources. Regarding the high occurrence of mold contamination in raw milk and environmental sources, it seems that in some instances heat treatment was not effective enough to inactivate all molds; whereas in some other cases, cross contamination may have resulted in mold contamination. Therefore, it is crucial to maintain hygienic conditions during raw milk handling as well as processing steps. These practices could efficiently reduce the occurrence of mold contaminations in dairy products.

  11. Development of magnesium semi-solid injection molding; Magnesium han`yoyu shashutsu seikei gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, K; Sakate, N; Ishida, K; Yamamoto, Y; Nishimura, K [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    Magnesium semi-solid injection molding is safety and clean process. We have investigated influence of molding conditions on mechanical properties and dimension accuracy of products by semi-solid injection molding. As a result it was proved that the accuracy of products by this process is superior to die casting. This advantage as well as better mechanical properties can be utilized for net shape molding of some automobile parts. 4 refs., 8 figs., 3 tabs.

  12. 40 CFR 63.5698 - What emission limit must I meet for open molding resin and gel coat operations?

    Science.gov (United States)

    2010-07-01

    ... open molding resin and gel coat operations? 63.5698 Section 63.5698 Protection of Environment... Manufacturing Standards for Open Molding Resin and Gel Coat Operations § 63.5698 What emission limit must I meet for open molding resin and gel coat operations? (a) You must limit organic HAP emissions from the five...

  13. 40 CFR 63.5810 - What are my options for meeting the standards for open molding and centrifugal casting operations...

    Science.gov (United States)

    2010-07-01

    ... standards for open molding and centrifugal casting operations at new and existing sources? 63.5810 Section... § 63.5810 What are my options for meeting the standards for open molding and centrifugal casting... (d) of this section to meet the standards for open molding or centrifugal casting operations in Table...

  14. DNA-Based Analyses of Molds in Singapore Public Buildings Results in a Proposed Singapore Environmental Relative Moldiness Index

    Science.gov (United States)

    Dust samples (n=75) were collected from shopping malls, hotels and libraries in Singapore and then analyzed using Mold Specific Quantitative Polymerase Chain Reaction(MSQPCR) for the 36 molds that make up the Environmental Relative Moldiness Index (ERMI). Most of these molds (23/...

  15. Reduction of birefringence in a skin-layer of injection molded polymer strips using CO{sub 2} laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kurosaki, Yasuo; Satoh, Isao; Saito, Takushi [Tokyo Inst. of Tech. (Japan). Dept. of Mechanical Intelligent Systems Engineering

    1995-12-31

    Injection molding of polymers is currently utilized for numerous industrial applications. Because of high productivity and stable quality of molded products, the injection-molding process makes the production costs lower, and therefore, is expected to spread more widely in the future. This paper deals with a technique for improving the optical quality of injection molded polymer products using radiative heating. The birefringence frozen in a skin-layer of the molded part was reduced by CO{sub 2} laser heating, and the efficiency of this technique was investigated experimentally. Namely, a simple numerical calculation was performed to estimate the heating efficiency of CO{sub 2} laser in the polymer, effects of radiation heating on the skin-layer of the molded polymer were observed by using a mold with transparent windows, and the residual birefringence frozen in the final molded specimen was measured. The results clearly showed that the birefringence in the skin-layer of injection molded polymer strips was reduced with CO{sub 2} laser heating. The authors believe that the proposed method for reducing the birefringence frozen in injection-molded polymer products is suitable for practical molding, because process time required for the injection-molding is only slightly increased with this method.

  16. POWDER INJECTION MOLDING OF SIC FOR THERMAL MANAGEMENT V

    Directory of Open Access Journals (Sweden)

    Valmikanathan Onbattuvelli

    2012-06-01

    Full Text Available Silicon carbide (SiC exhibits many functional properties that are relevant to applications in electronics, aerospace, defense and automotive industries. However, the successful translation of these properties into final applications lies in the net-shaping of ceramics into fully dense microstructures. Increasing the packing density of the starting powders is one effective route to achieve high sintered density and dimensional precision. The present paper presents an in-depth study on the effects of nanoparticle addition on the powder injection molding process (PIM of SiC powder-polymer mixtures. In particular, bimodal mixtures of nanoscale and sub-micrometer particles are found to have significantly increased powder packing characteristics (solids loading in the powder-polymer mixtures. The influence of nanoparticle addition on the multi-step PIM process is examined. The above results provide new perspectives which could impact a wide range of materials, powder processing techniques and applications.

  17. Antimicrobial Assay of Soil Mold Isolates from Wonorejo Surabaya

    Directory of Open Access Journals (Sweden)

    Septia Arisanti

    2012-11-01

    Full Text Available This study was aimed to an examine antimicrobial activity of 34 soil molds isolates from the Wonorejo Surabaya on the growth of Gram negatif bacteria (Escherichia coli and Coliform Bacteria Group, Gram positif bacteria (Bacillus subtilis and yeast (Saccharomyces cerevisiae. Antimicrobial ability detected with modification of dual culture antagonism assay in Potato Dextrose Agar (PDA medium. The result showed that genus Aspergillus, Scopulariopsis, Penicillium, Paecilomyces, Fusarium, and Trichoderma were able to inhibit E. coli; while genus Aspergillus, Scopulariopsis, Penicillium, Paecilomyces, Exophiala, Stachybotrys, and Acremonium inhibit B. subtilis; further on only genus Aspergillus could inhibit group of Coliform bacteria; and genus Scopulariopsis, Penicillium, Trichoderma, and Absidia inhibited the growth of yeast S. cerevisiae.

  18. Improving Powder Injection Molding: an Opportunity for the Aerospace Industry

    Directory of Open Access Journals (Sweden)

    I. Emri

    2014-01-01

    Full Text Available This work deals with powder injection molding (PIM technology of metal and ceramis powders using polyoximethylene (POM binder. In this study, two ways to decrease the viscosity of PIM feedstock materials with polyoxymethylene were investigated. The first way was to reduce the average molecular weight (AMV of the binder and the second one to select a polydisperse particle size distribution with high maximum packing fraction. It was shown that binder with AMW equal to 24410 g/mol gives required level of viscosity around 10 Pa/s. It was shown that using the low disperse powder with wide size distribution can lead to volumetric loading of approximately 83 %. Moreover, using such a feedstock has viscosity lower than required by PIM technology 1000 Pa/s.

  19. Friction behavior of ceramic injection-molded (CIM) brackets.

    Science.gov (United States)

    Reimann, Susanne; Bourauel, Christoph; Weber, Anna; Dirk, Cornelius; Lietz, Thomas

    2016-07-01

    Bracket material, bracket design, archwire material, and ligature type are critical modifiers of friction behavior during archwire-guided movement of teeth. We designed this in vitro study to compare the friction losses of ceramic injection-molded (CIM) versus pressed-ceramic (PC) and metal injection-molded (MIM) brackets-used with different ligatures and archwires-during archwire-guided retraction of a canine. Nine bracket systems were compared, including five CIM (Clarity™ and Clarity™ ADVANCED, both by 3M Unitek; discovery(®) pearl by Dentaurum; Glam by Forestadent; InVu by TP Orthodontics), two PC (Inspire Ice by Ormco; Mystique by DENTSPLY GAC), and two MIM (discovery(®) and discovery(®) smart, both by Dentaurum) systems. All of these were combined with archwires made of either stainless steel or fiberglass-reinforced resin (remanium(®) ideal arch or Translucent pearl ideal arch, both by Dentaurum) and with elastic ligatures or uncoated or coated stainless steel (all by Dentaurum). Archwire-guided retraction of a canine was simulated with a force of 0.5 N in the orthodontic measurement and simulation system (OMSS). Friction loss was determined by subtracting the effective orthodontic forces from the applied forces. Based on five repeated measurements performed on five brackets each, weighted means were calculated and evaluated by analysis of variance and a Bonferroni post hoc test with a significance level of 0.05. Friction losses were significantly (p brackets used with a stainless-steel ligature and the resin archwire. No critical difference to friction behavior was apparent between the various manufacturing technologies behind the bracket systems.

  20. Triple Plate Mold Final Report: Optimization of the Mold Design and Casting Parameters for a Thin U-10mo Fuel Casting

    Energy Technology Data Exchange (ETDEWEB)

    Aikin, Jr., Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-04

    This work describes the experiments and modeling that have been performed to improve and try to optimize the simultaneous casting of three plates of U-10wt%Mo in a single coil vacuum induction melting (VIM) furnace. The plates of interest are 280 mm wide by 203 mm tall by 5 mm thick (11" x 8" x 0.2"). The initial mold design and processing parameters were supplied by Y-12. The mold and casting cavity were instrumented with a number of thermocouples, and the casting performed to determine the thermal history of the mold and casting. The resulting cast plates were radiographed and numerous defects identified. Metallography was performed to help identify the nature of the radiographically observed defects. This information was then used to validate a mold filling and solidification model of that casting. Based on the initial casting, good casting design practice, and process simulation of several design alternatives, a revised design was developed with the goal of minimizing casting defects such as porosity. The redesigned mold had a larger hot-top and had its long axis along the horizontal direction. These changes were to try to develop a strong thermal gradient conducive to good feeding and minimization of micro- and macroporosity in the cast plates. An instrumented casting was then performed with the revised mold design and a linear distributor. This design yielded cast plates with significantly less radiographically identified defects. Unfortunately, there was significant variation in plate weight and metal content in their hot-tops. Fluid flow simulations were then performed on this mold/distributor design. This helped identify the issue with this linear distributor design. Additional simulations were then performed on candidate distributor redesigns and a preferred distributor annular design was identified. This improved annular design was used to produce a third instrumented casting with favorable results. These refined designs and their radiographic

  1. Structural and compositional analysis of a casting mold sherd from ancient China.

    Science.gov (United States)

    Zong, Yunbing; Yao, Shengkun; Lang, Jianfeng; Chen, Xuexiang; Fan, Jiadong; Sun, Zhibin; Duan, Xiulan; Li, Nannan; Fang, Hui; Zhou, Guangzhao; Xiao, Tiqiao; Li, Aiguo; Jiang, Huaidong

    2017-01-01

    Casting had symbolic significance and was strictly controlled in the Shang dynasty of ancient China. Vessel casting was mainly distributed around the Shang capital, Yin Ruins, which indicates a rigorous centralization of authority. Thus, for a casting mold to be excavated far from the capital region is rare. In addition to some bronze vessel molds excavated at the Buyao Village site, another key discovery of a bronze vessel mold occurred at Daxinzhuang. The Daxinzhuang site was a core area in the east of Shang state and is an important site to study the eastward expansion of the Shang. Here, combining synchrotron X-rays and other physicochemical analysis methods, nondestructive three-dimensional structure imaging and different elemental analyses were conducted on this mold sherd. Through high penetration X-ray tomography, we obtained insights on the internal structure and discovered some pores. We infer that the generation of pores inside the casting mold sherd was used to enhance air permeability during casting. Furthermore, we suppose that the decorative patterns on the surface were carved and not pasted onto it. Considering the previous compositional studies of bronze vessels, the copper and iron elements were analyzed by different methods. Unexpectedly, a larger amount of iron than of copper was detected on the surface. According to the data analysis and archaeological context, the source of iron on the casting mold sherd could be attributed to local soil contamination. A refined compositional analysis confirms that this casting mold was fabricated locally and used for bronze casting.

  2. Testing of molded high temperature plastic actuator road seals for use in advanced aircraft hydraulic systems

    Science.gov (United States)

    Waterman, A. W.; Huxford, R. L.; Nelson, W. G.

    1976-01-01

    Molded high temperature plastic first and second stage rod seal elements were evaluated in seal assemblies to determine performance characteristics. These characteristics were compared with the performance of machined seal elements. The 6.35 cm second stage Chevron seal assembly was tested using molded Chevrons fabricated from five molding materials. Impulse screening tests conducted over a range of 311 K to 478 K revealed thermal setting deficiencies in the aromatic polyimide molding materials. Seal elements fabricated from aromatic copolyester materials structurally failed during impulse cycle calibration. Endurance testing of 3.85 million cycles at 450 K using MIL-H-83283 fluid showed poorer seal performance with the unfilled aromatic polyimide material than had been attained with seals machined from Vespel SP-21 material. The 6.35 cm first stage step-cut compression loaded seal ring fabricated from copolyester injection molding material failed structurally during impulse cycle calibration. Molding of complex shape rod seals was shown to be a potentially controllable technique, but additional molding material property testing is recommended.

  3. Assessment of indoor air in Austrian apartments with and without visible mold growth

    Science.gov (United States)

    Haas, D.; Habib, J.; Galler, H.; Buzina, W.; Schlacher, R.; Marth, E.; Reinthaler, F. F.

    Fungal spores are transported across great distances in the outdoor air and are also regularly found indoors. Building conditions and behavior-related problems in apartments may lead to massive growth of mold within a very short period of time. The aim of this study was to evaluate whether the visible growth of mold indoors influences the concentration of fungal spores in the air as well as the variety of their species. Samples were collected from 66 households in Austria. For each sampling, the corresponding outdoor air was measured as reference value. The size of the visible mold growth was categorized in order to correlate the extent of mold growth with the concentration of airborne spores as well as the fungal genera. In order to determine fungal spore concentrations in the air, the one-stage MAS-100 ® air sampler was used. Malt extract agar (MEA) and dichloran glycerol agar (DG18) plates were used as culture media. The total colony forming units (CFU) per m 3 were determined. The fungi were identified from the isolated colonies. The results show that in apartments visibly affected by mold, the median values were significantly higher than those of apartments without visible mold growth. The extent of visible mold growth is significantly correlated with both concentration of fungal spores ( pPenicillium sp. and Aspergillus sp. ( pPenicillium and Aspergillus in the air of apartments is recommended for assessing fungal exposure.

  4. Measurement and assessment of aflatoxin B1 and its producing molds in Iranian sausages and burgers

    Directory of Open Access Journals (Sweden)

    Siavash Maktabi

    2016-09-01

    Full Text Available Abstract Introduction: Aflatoxin B1 (AFB1 is one of the most well-known hepatocarcinogens in humans. Contamination of raw materials, used in the production of sausages and burgers, with aflatoxin producing molds can lead to increased level of aflatoxin in the final products and can impose hazards to human health. Unfortunately, aflatoxin is resistant to heating and freezing processes, etc. and can remain in these products untile consumption. Methods: During a six-month period, 45 sausage and 53 burger samples from valid brands across the country were randomly purchased from the stores. The samples were analyzed for AFB1 by ELISA technique. Meanwhile, the number of molds was calculated and aflatoxin producing molds were identified by direct and slide culture methods. Results: The findings showed that 2 susage samples (4.9% and 3 burger samples (6.3% were contaminated with >1 ng/g aflatoxin. Moreover, 4 burger samples (8.9% contaminated with mold included aspergillus flavus, aspergillus niger, mucor, and penicillium while, none of the susage samples showed mold contamination. Conclusion: The Iranian meat products had a relative aflatoxin B1 contamination during the study period, but the contamination rate was low and in allowable range. Standard hygienic preparation and packaging of meat products molds is recommended to reduce fungal contamination, especially aflatoxin-producing molds.

  5. Dimensional accuracy optimization of the micro-plastic injection molding process using the Taguchi design method

    Directory of Open Access Journals (Sweden)

    Chil-Chyuan KUO KUO

    2015-06-01

    Full Text Available Plastic injection molding is an important field in manufacturing industry because there are many plastic products that produced by injection molding. However, the time and cost required for producing a precision mold are the most troublesome problems that limit the application at the development stage of a new product in precision machinery industry. This study presents an approach of manufacturing a hard mold with microfeatures for micro-plastic injection molding. This study also focuses on Taguchi design method for investigating the effect of injection parameters on the dimensional accuracy of Fresnel lens during plastic injection molding. It was found that the dominant factor affecting the microgroove depth of Fresnel lens is packing pressure. The optimum processing parameters are packing pressure of 80 MPa, melt temperature of 240 °C, mold temperature of 90 °C and injection speed of 50 m/s. The dimensional accuracy of Fresnel lens can be controlled within ±3 µm using the optimum level of process parameters through the confirmation test. The research results of this study have industrial application values because electro-optical industries are able to significantly reduce a new optical element development cycle time.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.5864

  6. Effects of heat pipe cooling on permanent mold castings of aluminum alloys

    International Nuclear Information System (INIS)

    Zhang, C.; Mucciardi, F.; Gruzleski, J.E.

    2002-01-01

    The temperature distribution within molds is a critical parameter in determining the ultimate casting quality in permanent mold casting processes, so there is a considerable incentive to develop a more effective method of mold cooling. Based on this consideration, a novel, effective and controllable heat pipe has been successfully developed and used as a new method of permanent mold cooling. Symmetric step casting of A356 alloy have been produced in an experimental permanent mold made of H13 tool steel, which is cooled by such heat pipes. The experimental results show that heat pipes can provide extremely high cooling rates in permanent mold castings of aluminum. The dendrite arm spacing of A356 alloy is refined considerably, and porosity and shrinkage of the castings are redistributed by the heat pipe cooling. Moreover, the heat pipe can be used to determine the time when the air gap forms at the interface between the mold and the casting. The effect of heat pipe cooling on solidification time of castings of A356 alloy with different coating types is also discussed in this paper. (author)

  7. Structural and compositional analysis of a casting mold sherd from ancient China.

    Directory of Open Access Journals (Sweden)

    Yunbing Zong

    Full Text Available Casting had symbolic significance and was strictly controlled in the Shang dynasty of ancient China. Vessel casting was mainly distributed around the Shang capital, Yin Ruins, which indicates a rigorous centralization of authority. Thus, for a casting mold to be excavated far from the capital region is rare. In addition to some bronze vessel molds excavated at the Buyao Village site, another key discovery of a bronze vessel mold occurred at Daxinzhuang. The Daxinzhuang site was a core area in the east of Shang state and is an important site to study the eastward expansion of the Shang. Here, combining synchrotron X-rays and other physicochemical analysis methods, nondestructive three-dimensional structure imaging and different elemental analyses were conducted on this mold sherd. Through high penetration X-ray tomography, we obtained insights on the internal structure and discovered some pores. We infer that the generation of pores inside the casting mold sherd was used to enhance air permeability during casting. Furthermore, we suppose that the decorative patterns on the surface were carved and not pasted onto it. Considering the previous compositional studies of bronze vessels, the copper and iron elements were analyzed by different methods. Unexpectedly, a larger amount of iron than of copper was detected on the surface. According to the data analysis and archaeological context, the source of iron on the casting mold sherd could be attributed to local soil contamination. A refined compositional analysis confirms that this casting mold was fabricated locally and used for bronze casting.

  8. Molding of strength testing samples using modern PDCPD material for purpose of automotive industry

    Science.gov (United States)

    Grabowski, L.; Baier, A.; Sobek, M.

    2017-08-01

    The casting of metal materials is widely known but the molding of composite polymer materials is not well-known method still. The initial choice of method for producing composite bodies was the method of casting of PDCPD material. For purpose of performing casting of polymer composite material, a special mold was made. Firstly, the 3D printed, using PLA material, mold was used. After several attempts of casting PDCPD many problems were encountered. The second step was to use mold milled from a firm and dense isocyanate foam. After several attempts research shown that this solution is more resistant to high-temperature peak, but this material is too fragile to use it several times. This solution also prevents mold from using external heating, which can be necessary for performing correct molding process. The last process was to use the aluminum mold, which is dedicated to PDCPD polymer composite, because of low adhesiveness. This solution leads to perform correct PDCPD polymer composite material injection. After performing casting operation every PDCPD testing samples were tested. These results were compared together. The result of performed work was to archive correct properties of injection of composite material. Research and results were described in detail in this paper.

  9. Reirradiation of nasopharyngeal carcinoma with intracavitary mold brachytherapy: an effective means of local salvage

    International Nuclear Information System (INIS)

    Law, Stephen C.K.; Lam, W.-K.; Ng, M.-F.; Au, S.-K.; Mak, W.-T.; Lau, W.-H.

    2002-01-01

    Purpose: To assess the role of intracavitary mold brachytherapy in salvaging local failure of nasopharyngeal carcinoma (NPC). Methods and Materials: The outcomes of 118 consecutive NPC patients with local failure treated with mold brachytherapy between 1989 and 1996 were retrospectively reviewed. Eleven patients received additional external radiotherapy. Results: All molds were tailor-made, and the whole procedure was performed under local anesthesia. Pharyngeal recess dissection was routinely performed to allow direct contact of the radioactive source with the pharyngeal recess, a common site of local failure. Initially, the molds were preloaded with 192 Ir wires, but since 1992, the sources have been manually afterloaded; the mold has also been redesigned for better conformity, ease of insertion, and radiation safety. Using brachytherapy alone, 50-55 Gy was given for recurrence in 4-7 days; for persistence, 40 Gy was administered. The overall complete remission rate was 97%. The rates of 5-year local control, relapse-free survival, disease-specific survival, overall survival, and major complication were 85%, 68.3%, 74.8%, 61.3%, and 46.9%, respectively. Major complications included nasopharyngeal necrosis with headache, necrosis of cervical vertebrae with atlantoaxial instability, temporal lobe necrosis, and palsy of the cranial nerves. The afterloaded mold was as effective as the preloaded version, but with fewer complications. Conclusions: Intracavitary mold brachytherapy was effective in salvaging NPC with early-stage local persistence or first recurrence

  10. Desain dan Optimasi Injection Mold Sistem Slider pada Produk Stick T15

    Directory of Open Access Journals (Sweden)

    Lutfi Khoirul Miftakhul Ni'am

    2017-12-01

    Full Text Available The design of injection molding is the initial process to produce a large-scale product of plastic material which heated and injected into the mold. Design of the preform mold using the plastic material polyethylene terephthalate with the construction of the slider, so that the products which was made have undercut and can’t be made in the core section and cavity. The purpose of this design is to design the slider on the product preform. The software which used for this design using CATIA V5R19 and simulation software production using Autodesk Moldflow Insight 2016. The step on designing a unit injection mold in the preform includes several steps. The first step is identify the product, the calculation of the cooling and input the data calculation result to an moldflow. The second step is design construction slider and determine the mold material as well as calculating the construction mold. The third step is pour the results of the design in figure 2D. Based on the analysis results from moldflow obtained cooling optimal.i.e. the type of cooling series type 2, and if can be concluded construction of the mold said to be safe if the stress, the style and the determination  of material which occurs under the stress and style of permit.

  11. Coping With Cleft: A Conceptual Framework of Caregiver Responses to Nasoalveolar Molding.

    Science.gov (United States)

    Sischo, Lacey; Broder, Hillary L; Phillips, Ceib

    2015-11-01

    To present a conceptual framework of caregiver coping and adaptation to early cleft care using nasoalveolar molding. In-depth interviews were conducted at three time points with caregivers of infants with cleft lip or cleft lip and palate whose children had nasoalveolar molding to treat their cleft. Qualitative data were analyzed using modified grounded theory. Most caregivers expressed initial apprehension and anxiety about the responsibilities of care associated with nasoalveolar molding (e.g., changing and positioning tapes, cleaning the appliance). In subsequent interviews, caregivers often reported positive feelings related to their active participation in their child's treatment for cleft. These positive feelings were associated with increased self-esteem and feelings of empowerment for the caregivers. Although caregivers also identified burdens associated with nasoalveolar molding (e.g., stress related to lip taping, concerns about the appliance causing sores in their child's mouth, travel to weekly appointments), they tended to minimize the impact of these issues in comparison with the perceived benefits of nasoalveolar molding. Despite the increased burden of care, many caregivers of infants with cleft used nasoalveolar molding as a problem-focused coping strategy to deal with their child's cleft. Completing nasoalveolar molding was often associated with positive factors such as increased empowerment, self-esteem, and bonding with their infant.

  12. Chemical and mineralogical aspects of clay-salt slimes of 'Belaruskali' using for the preparation of nano-structured sorbents of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Maskalchuk, L.; Baklay, A.; Leontieva, T. [Joint Institute for Power and Nuclear Research - Sosny, NAS of Belarus, Minsk, P.O.Box 119, 220109 (Belarus)

    2016-07-01

    n the context of intensive nuclear-power engineering development there is an urgent need to solve a range of technological and environmental challenges associated with generation, treatment and disposal of radioactive waste. In this regards, the problems of radioactive waste safe management and rehabilitation of radioactively contaminated soils in the result of the radiation accidents at the Chernobyl and Fukushima Daiichi NPPs are especially significant. Concerning that, investigation of effective and low cost sorption materials for radionuclides immobilization has a special relevance. In order to solve the above mentioned problems, it is supposed to develop a resource-saving technology for production of multi-purpose nano-structured sorbents of radionuclides ({sup 137}Cs, {sup 90}Sr) with predetermined physicochemical properties based on the waste of potash industry - clay-salt slimes (CSS) of the JSC 'Belaruskali'. The performed research has shown that the CSS samples have a high fixing ability in relation to {sup 137}Cs. The main sorption-active minerals in CSS are illite and montmorillonite. The degree of sorption is 99.6%, K{sub d} is 1.2*10{sup 5} l/kg, RIP(K) is 6343 mmol/kg. The modification of the S-1 sample allows to enlarge the content of sorption-active minerals tentatively in 3.5 times, thereafter RIP(K) for the S-3 sample may be significantly increased. Based on the obtained experimental data, CSS of the JSC 'Belaruskali' can be estimated as a perspective initial material for production of multi-purpose nano-structured sorbents of radionuclides. (authors)

  13. Traceability of Height Measurements on Green Sand Molds using Optical 3D Scanning

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, S.A.; Tiedje, N. S.

    2016-01-01

    Establishing a reliable measurement procedure for dimensional measurements on green sand molds is a prerequisite for analysis of geometric deviations in mass production of quality castings. Surface of the green sand mold is not suitable for measurements using a tactile coordinate measuring machine....... This paper presents a metrological approach for height measurement on green sand molds using an optical 3D scanner with fringe projection. A new sand sample was developed with a hard binder to withstand the contact force of a touch probe, while keeping optical cooperativeness similar to green sand...

  14. Numerical modeling of magnetic induction and heating in injection molding tools

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Hattel, Jesper Henri

    2013-01-01

    the temperatures as close as possible to the cavity surface, by means of an integrated induction heating system in the injection molding tool, to improve the fluidity of the polymer melt hereby ensuring that the polymer melt will continue to flow until the mold cavity is completely filled. The presented work uses......Injection molding of parts with special requirements or features such as micro- or nanostructures on the surface, a good surface finish, or long and thin features results in the need of a specialized technique to ensure proper filling and acceptable cycle time. The aim of this study is to increase...

  15. Numerical simulation of mold shape’s influence on NbTi cold-pressing superconducting joint

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Feng, E-mail: zhoufeng@mail.iee.ac.cn; Cheng, Junsheng; Dai, Yinming; Wang, Qiuliang; Yan, Luguang

    2014-03-15

    Highlights: • Four different shape molds’ influence on NbTi cold-pressing joint are analyzed. • Deformation of filaments is the most uniform in the case of radial compression. • The square mold is the optimum one for decreasing joint resistance in practice. - Abstract: The cold-pressing welding methods are employed to fabricate joints between NbTi multi-filamentary conductors, and a series of joints are made with the molds of different shapes for nuclear magnetic resonance (NMR) magnet applications. The Abaqus–Explicit method was used to do a quasi-static analysis of the cold-pressing welding process. In the simulation, we analyzed four molds with different shapes: plate mold, cap mold, square mold, and radial compression. The simulation shows that the deformation of filaments is the most uniform in the case of radial compression and the square mold is the optimum one for decreasing joint resistance.

  16. Study of microcellular injection-molded polypropylene/waste ground rubber tire powder blend

    International Nuclear Information System (INIS)

    Xin, Zhen Xiang; Zhang, Zhen Xiu; Pal, Kaushik; Byeon, Jong Ung; Lee, Sung Hyo; Kim, Jin Kuk

    2010-01-01

    Microcellular polypropylene/waste ground rubber tire powder blend processing was performed on an injection-molding machine with a chemical foaming agent. The molded samples produced based on the design of experiments (DOE) matrices were subjected to tensile testing and scanning electron microscope (SEM) analyses. Molding conditions and waste ground rubber tire (WGRT) powder have been found to have profound effects on the cell structures and mechanical properties of polypropylene (PP) and waste ground rubber tire powder composite samples. The result shows that microcellular PP/WGRT blend samples exhibit smaller cell size and higher cell density compare with polypropylene resin. Among the molding parameters studied, chemical foaming agent weight percentage has the most significant effect on cell size, cell density, and tensile strength. The results also suggest that tensile strength of microcellular PP/WGRT composites is sensitive to weight reduction, and skin thickness.

  17. Microlens fabrication by replica molding of frozen laser-printed droplets

    Science.gov (United States)

    Surdo, Salvatore; Diaspro, Alberto; Duocastella, Martí

    2017-10-01

    In this work, we synergistically combine laser-induced forward transfer (LIFT) and replica molding for the fabrication of microlenses with control of their geometry and size independent of the material or substrate used. Our approach is based on a multistep process in which liquid microdroplets of an aqueous solution are first printed on a substrate by LIFT. Following a freezing step, the microdroplets are used as a master to fabricate a polydimethylsiloxane (PDMS) mold. A subsequent replica molding step enables the creation of microlenses and microlens arrays on arbitrary selected substrates and by using different curable polymers. Thus, our method combines the rapid fabrication capabilities of LIFT and the perfectively smooth surface quality of the generated microdroplets, with the advantages of replica molding in terms of parallelization and materials flexibility. We demonstrate our strategy by generating microlenses of different photocurable polymers and by characterizing their optical and morphological properties.

  18. Precision Glass Molding: Validation of an FE Model for Thermo-Mechanical Simulation

    DEFF Research Database (Denmark)

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

    2014-01-01

    glass molding process including heating, pressing, and cooling stages. Temperature- dependent viscoelastic and structural relaxation behavior of the glass material are implemented through a FORTRAN material subroutine (UMAT) into the commercial FEM program ABAQUS, and the FE model is validated...

  19. Process for the production of prismatic graphite molded articles for high temperature fuel elements

    International Nuclear Information System (INIS)

    Huschka, H.; Rachor, L.; Hrovat, M.; Wolff, W.

    1976-01-01

    Prismatic graphite molded objects for high temperature fuel elements are prepared by producing the outer geometry and the holes for cooling channels and for receiving fuel and fertile materials in the formation of the carbon object

  20. Validation of precision powder injection molding process simulations using a spiral test geometry

    DEFF Research Database (Denmark)

    Marhöfer, Maximilian; Müller, Tobias; Tosello, Guido

    2015-01-01

    Like in many other areas of engineering, process simulations find application in precision injection molding to assist and optimize the quality and design of precise products and the molding process. Injection molding comprises mainly the manufacturing of plastic components. However, the variant ....... The necessary data and the implementation procedure of the new material models are outlined. In order to validate the simulation studies and evaluate their accuracy, the simulation results are compared with experiments performed using a spiral test geometry...... for powder injection molding. This characterization includes measurements of rheological, thermal, and pvT behavior of the powder-binder-mixes. The acquired material data was used to generate new material models for the database of the commercially available Autodesk Moldflow® simulation software...

  1. A feasible injection molding technique for the manufacturing of large diameter aspheric plastic lenses

    Science.gov (United States)

    Shieh, Jen-Yu; Wang, Luke K.; Ke, Shih-Ying

    2010-07-01

    A computer aided engineering (CAE) tool-assisted technique, using Moldex3D and aspheric analysis utility (AAU) software in a polycarbonate injection molding design, is proposed to manufacture large diameter aspheric plastic lenses. An experiment is conducted to verify the applicability/feasibility of the proposed technique. Using the preceding two software tools, these crucial process parameters associated with the surface profile errors and birefringence of a molded lens can be attainable. The strategy adopted here is to use the actual quantity of shrinkage after an injection molding trial of an aspherical plastic lens as a reference to perform the core shaping job while keeping the coefficients of aspheric surface, radius, and conic constant unchanged. The design philosophy is characterized by using the CAE tool as a guideline to pursue the best symmetry condition, followed by injection molding trials, to accelerate a product’s developmental time. The advantages are less design complexity and shorter developmental time for a product.

  2. Frequency and amplitude dependences of molding accuracy in ultrasonic nanoimprint technology

    International Nuclear Information System (INIS)

    Mekaru, Harutaka; Takahashi, Masaharu

    2009-01-01

    We use neither a heater nor ultraviolet lights, and are researching and developing an ultrasonic nanoimprint as a new nano-patterning technology. In our ultrasonic nanoimprint technology, ultrasonic vibration is not used as a heat generator instead of the heater. A mold is connected with an ultrasonic generator, and mold patterns are pushed down and pulled up at a high speed into a thermoplastic. Frictional heat is generated by ultrasonic vibration between mold patterns and thermoplastic patterns formed by an initial contact force. However, because frictional heat occurs locally, the whole mold is not heated. Therefore, a molding material can be comprehensively processed at room temperature. A magnetostriction actuator was built into our ultrasonic nanoimprint system as an ultrasonic generator, and the frequency and amplitude can be changed between dc–10 kHz and 0–4 µm, respectively. First, the ultrasonic nanoimprint was experimented by using this system on polyethylene terephthalate (PET, T g = 69 °C), whose the glass transition temperature (T g ) is comparatively low in engineering plastics, and it was ascertained that the most suitable elastic material for this technique was an ethyl urethane rubber. In addition, we used a changeable frequency of the magnetostriction actuator, and nano-patterns in an electroformed-Ni mold were transferred to a 0.5 mm thick sheet of PET, polymethylmethacrylate (PMMA) and polycarbonate (PC), which are typical engineering plastics, under variable molding conditions. The frequency and amplitude dependence of ultrasonic vibration to the molding accuracy were investigated by measuring depth and width of imprinted patterns. As a result, regardless of the molding material, the imprinted depth was changed drastically when the frequency exceeded 5 kHz. On the other hand, when the amplitude of ultrasonic vibration grew, the imprinted depth gradually deepened. Influence of the frequency and amplitude of ultrasonic vibration was not

  3. Stress and Friction Distribution around Slab Corner in Continuous Casting Mold with Different Corner Structures

    Science.gov (United States)

    Yu, Sheng; Long, Mujun; Chen, Huabiao; Chen, Dengfu; Liu, Tao; Duan, Huamei; Cao, Junsheng

    2018-06-01

    The non-uniform friction and thermal stress in the mold are important as causes of the transverse cracks around strand corner. To analyze the stress distribution features around strand corner, a three-dimensional thermo-elastoplastic finite-element mold model with different corner structures (right-angle, big-chamfer, multi-chamfer, and fillet) was established. The temperature field in the mold was indirectly coupled through a three-dimensional fluid flow and heat transfer model. In addition, the non-uniform mold friction stress loaded on the strand surface was calculated through a friction model. The results show that the stress distribution on the shell is similar to the temperature distribution. The stress concentration appears in the strand corner and the lower part of wide face. The friction stress enhances the corner stress around the edge of the air-gap. For chamfered molds, the stress around the corner between the wide face and chamfer face is larger than that between the narrow face and chamfer face. Around the corner region, both the stress peak and the area of the large stress zone of the right-angle strand are the largest, while those of big-chamfered, multi-chamfered, and fillet strands decrease in that order. The stress peak position of the chamfered strands is closer to the mold exit than that of the right-angle strand. Compared with the use of the right-angle mold, the application of chamfered molds is able to reduce the stress concentration around the strand corner.

  4. Stress and Friction Distribution around Slab Corner in Continuous Casting Mold with Different Corner Structures

    Science.gov (United States)

    Yu, Sheng; Long, Mujun; Chen, Huabiao; Chen, Dengfu; Liu, Tao; Duan, Huamei; Cao, Junsheng

    2018-02-01

    The non-uniform friction and thermal stress in the mold are important as causes of the transverse cracks around strand corner. To analyze the stress distribution features around strand corner, a three-dimensional thermo-elastoplastic finite-element mold model with different corner structures (right-angle, big-chamfer, multi-chamfer, and fillet) was established. The temperature field in the mold was indirectly coupled through a three-dimensional fluid flow and heat transfer model. In addition, the non-uniform mold friction stress loaded on the strand surface was calculated through a friction model. The results show that the stress distribution on the shell is similar to the temperature distribution. The stress concentration appears in the strand corner and the lower part of wide face. The friction stress enhances the corner stress around the edge of the air-gap. For chamfered molds, the stress around the corner between the wide face and chamfer face is larger than that between the narrow face and chamfer face. Around the corner region, both the stress peak and the area of the large stress zone of the right-angle strand are the largest, while those of big-chamfered, multi-chamfered, and fillet strands decrease in that order. The stress peak position of the chamfered strands is closer to the mold exit than that of the right-angle strand. Compared with the use of the right-angle mold, the application of chamfered molds is able to reduce the stress concentration around the strand corner.

  5. Effect of gas release in hot molding on flexural strength of composite friction brake

    Science.gov (United States)

    Rusdja, Andy Permana; Surojo, Eko; Muhayat, Nurul; Raharjo, Wijang Wisnu

    2018-02-01

    Composite friction brake is a vital part of braking system which serves to reduce the speed of vehicle. To fulfill the requirement of brake performance, composite friction brake must have friction and mechanical characteristic as required. The characteristics of composite friction brake are affected by brake material formulation and manufacturing parameter. In the beginning of hot molding, intermittent hot pressing was carried out to release the gases that consist of ammonia gas and water vapor. In composite friction brake, phenolic resin containing hexamethylenetetramine (HMTA) is often used as a binder. During hot molding, the reaction of phenolic resin and HMTA forms ammonia gas. Hot molding also generates water vapor because raw materials absorb moisture from environment when they are placed in storage. The gas release in hot molding is supposed affecting mechanical properties because it avoid entrapped gas in composite, so that this research investigated effect of gas release on flexural strength. Manufacturing of composite specimen was carried out as follow: mixing of raw materials, cold molding, and hot molding. In this research, duration of intermittent hot pressing and number of gas release were varied. The flexural strength of specimen was measured using three point bending test. The results showed that flexural strength specimens that were manufactured without gas release, using 4 times gas release with intermittent hot pressing for 5 and 10 seconds were not remarkably different. Conversely, hot molding using 4 times gas release with intermittent hot pressing for 15 seconds decreased flexural strength of composite. Hot molding using 2, 4, and 8 times gas release with intermittent hot pressing for 10 seconds also had no effect on increasing flexural strength. Increasing of flexural strength of composite was obtained only by using 6 times gas release with intermittent hot pressing for 10 seconds.

  6. Isolation and Identification of Contaminant Molds on Pumpkin Candy From Sumbawa Besar

    OpenAIRE

    Henny Nurul Khasanah, Utami Sri Hastuti, Linda Hapsari

    2015-01-01

    Pumpkin candy is a sort of pumpkin fruit processed products that is typical food from Sumbawa Besar. Pumpkin candy contains carbohydrates, fats, protein, fiber, and minerals. The mold can contaminate and degradate the pumpkin candy compounds, thus lowering the quality of the pumpkins candy. The purpose of this research were: 1) to identify the species of contaminant mold on candy pumpkin; 2) to determining the most dominant species on the pumpkins candy. The research were conducted at the Mic...

  7. Comparison of glare in YAG-damaged intraocular lenses: injection-molded versus lathe-cut.

    Science.gov (United States)

    Bath, P E; Dang, Y; Martin, W H

    1986-11-01

    A comparative analysis of YAG laser intraocular lens (IOL) damage was undertaken on injection-molded and lathe-cut IOLs. Damage sites were evaluated with polarized light. A consistent positive polarization was observed in the damage sites of lathe-cut IOLs. A consistent negative polarization was observed in the damage sites of injection-molded IOLs. The presence of positive polarization in IOL damage sites may be correlated with increased potential for glare. Results and clinical implications are discussed.

  8. Technical assistance for development of thermally conductive nitride filler for epoxy molding compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Jin; Song, Kee Chan; Jung, In Ha

    2005-07-15

    Technical assistance was carried out to develop nitride filler for thermally conductive epoxy molding compounds. Carbothermal reduction method was used to fabricate silicon nitride powder from mixtures of silica and graphite powders. Microstructure and crystal structure were observed by using scanning electron microscopy and x-ray diffraction technique. Thermal properties of epoxy molding compounds containing silicon nitride were measured by using laser flash method. Fabrication process of silicon nitride nanowire was developed and was applied to a patent.

  9. The Effect of Masterbatch Recipes on the Homogenization Properties of Injection Molded Parts

    OpenAIRE

    Zsíros, László; Török, Dániel; Kovács, József Gábor

    2017-01-01

    Appearance is a key factor in most injection molding applications. Unfortunately, there is no widespread method to objectively test visual appearance, such as color inhomogeneity of the parts or other surface defects. We developed an evaluation method to characterize the color inhomogeneity of injection molded parts. First, we examined manufacturing conditions and masterbatch recipes and then the individual effects of the components and their interactions on homogeneity.

  10. The Effect of Masterbatch Recipes on the Homogenization Properties of Injection Molded Parts

    Directory of Open Access Journals (Sweden)

    László Zsíros

    2017-01-01

    Full Text Available Appearance is a key factor in most injection molding applications. Unfortunately, there is no widespread method to objectively test visual appearance, such as color inhomogeneity of the parts or other surface defects. We developed an evaluation method to characterize the color inhomogeneity of injection molded parts. First, we examined manufacturing conditions and masterbatch recipes and then the individual effects of the components and their interactions on homogeneity.

  11. Energy Absorption in Chopped Carbon Fiber Compression Molded Composites

    International Nuclear Information System (INIS)

    Starbuck, J.M.

    2001-01-01

    In passenger vehicles the ability to absorb energy due to impact and be survivable for the occupant is called the ''crashworthiness'' of the structure. To identify and quantify the energy absorbing mechanisms in candidate automotive composite materials, test methodologies were developed for conducting progressive crush tests on composite plate specimens. The test method development and experimental set-up focused on isolating the damage modes associated with the frond formation that occurs in dynamic testing of composite tubes. Quasi-static progressive crush tests were performed on composite plates manufactured from chopped carbon fiber with an epoxy resin system using compression molding techniques. The carbon fiber was Toray T700 and the epoxy resin was YLA RS-35. The effect of various material and test parameters on energy absorption was evaluated by varying the following parameters during testing: fiber volume fraction, fiber length, fiber tow size, specimen width, profile radius, and profile constraint condition. It was demonstrated during testing that the use of a roller constraint directed the crushing process and the load deflection curves were similar to progressive crushing of tubes. Of all the parameters evaluated, the fiber length appeared to be the most critical material parameter, with shorter fibers having a higher specific energy absorption than longer fibers. The combination of material parameters that yielded the highest energy absorbing material was identified

  12. Metal Injection Molding (MIM of NdFeB Magnets

    Directory of Open Access Journals (Sweden)

    Hartwig T.

    2014-07-01

    Full Text Available Due to the increased and unstable prices for Rare Earth elements there are activities to develop alternative hard magnetic materials. Reducing the amount of material necessary to produce complex sintered NdFeB magnets can also help to reduce some of the supply problem. Metal Injection Molding (MIM is able to produce near net shape parts and can reduce the amount of finishing to achieve final geometry. Although MIM of NdFeB has been patented and published fairly soon after the development of the NdFeB magnets there has never been an industrial production. This could be due to the fact that MIM was very young at that time and hardly developed. Thus, the feasibility of the process needs to be revaluated. This paper presents results of our work on determining the process parameters influencing the magnetic properties of the sintered magnets as well as the shrinkage during processing. The role of binder and powder loading on the alignment of the particles as well as on the carbon and oxygen contamination was examined.

  13. Hot Runner Mold Design of Fan Diverter Parts

    Science.gov (United States)

    Juan, D. J.; Cheng, Y. L.

    2017-09-01

    In this study, we discuss the case of plastic parts for the production of fan steering gear shaft parts injection molding, and use POM plastic steel to produce plastic parts from traditional cold runners. Because of the parts have a hole, which need side slide. The runner produce more waste after plastic parts injection make the runner waste account for the cost is relatively high, the cost of stock preparation is relatively increased when the product quantity demanded is great. After the crushing treatment of the waste, the backfill will affect the quality, and in the crushing process, the volume generated will make the operator to withstand up to 130 dB of noise. The actual test results show that the production cycle reduce 6.25%, while the production yield increase by about 5% and material costs reduced by 2% . It can be recovered within a year, not to mention the increase of the quality and reduction the noise on the staff of the benefit is impossible to estimate.

  14. ¿Qué moldes mentales conforman un optimismo inteligente?

    Directory of Open Access Journals (Sweden)

    Pedro Hernández-Guanir

    2009-01-01

    Full Text Available El optimismo se ha realzado a partir de la teoría de la Indefensión Aprendida en la llamada Psicología Positiva. Ha sido un constructo valioso y útil para relacionarlo con distintas variables psicológicas, especialmente para predecir una mejor salud y una menor vulnerabilidad a las enfermedades. Sin embargo, no ha contado con una fundamentación teórica adecuada, manejándose dos enfoques, el disposicional y el atribucional. Nosotros creemos que existen varios tipos de optimismos, y cada uno de ellos tiene diferente valor funcional. Por ello, este informe recapitula cinco estudios, objeto de futuras publicaciones, donde se demuestra tal multiplicidad, tanto desde una perspectiva situacional (contextual como transituacional (tendencia. A su vez, se demuestra el nivel de adecuación de cada tipo de optimismo en relación con diferentes criterios como son adaptación personal, escolar, social, bienestar subjetivo, convivencia y rendimiento académico. Por último, a través de análisis discriminante, los distintos moldes mentales o estrategias cognitivo-afectivas explican lo que supone y aporta cada uno de los distintos optimismos.

  15. PETIs as High-Temperature Resin-Transfer-Molding Materials

    Science.gov (United States)

    Connell, John N.; Smith, Joseph G., Jr.; Hergenrother, Paul M.

    2005-01-01

    Compositions of, and processes for fabricating, high-temperature composite materials from phenylethynyl-terminated imide (PETI) oligomers by resin-transfer molding (RTM) and resin infusion have been developed. Composites having a combination of excellent mechanical properties and long-term high-temperature stability have been readily fabricated. These materials are particularly useful for the fabrication of high-temperature structures for jet-engine components, structural components on highspeed aircraft, spacecraft, and missiles. Phenylethynyl-terminated amide acid oligomers that are precursors of PETI oligomers are easily made through the reaction of a mixture of aromatic diamines with aromatic dianhydrides at high stoichiometric offsets and 4-phenylethynylphthalic anhydride (PEPA) as an end-capper in a polar solvent such as N-methylpyrrolidinone (NMP). These oligomers are subsequently cyclodehydrated -- for example, by heating the solution in the presence of toluene to remove the water by azeotropic distillation to form low-molecular-weight imide oligomers. More precisely, what is obtained is a mixture of PETI oligomeric species, spanning a range of molecular weights, that exhibits a stable melt viscosity of less than approximately 60 poise (and generally less than 10 poise) at a temperature below 300 deg C. After curing of the oligomers at a temperature of 371 deg C, the resulting polymer can have a glass-transition temperature (Tg) as high as 375 C, the exact value depending on the compositions.

  16. Direct diamond turning of steel molds for optical replication

    Science.gov (United States)

    Klocke, Fritz; Dambon, Olaf; Bulla, Benjamin; Heselhaus, Michael

    2009-05-01

    In this paper the most recent investigations in ultrasonic assisted diamond machining of hardened steel at the Fraunhofer IPT is presented. The goal of this technology is to unify the outrageous specifications of diamond machining process with steel material. The focus lies on the kinematic influence of the discrete frequencies 40 kHz and 60 kHz. Special interest is given to the reachable surface roughness depending on process parameters. The machined steel (1.2083, X40Cr14, STAVAX ESU) is a common mold die material for optical replication processes.Results of the accomplished investigations show the potential of the ultrasonic assisted process and recent developments. By increasing the frequency from 40 kHz to 60 kHz the overall process stability is increased. This makes the process less vulnerable towards feed rate variation or towards the variation of machined material hardness. Furthermore no tool wear is detected at high material removal rates or high cutting distances during component machining.

  17. Cell biology of the Koji mold Aspergillus oryzae.

    Science.gov (United States)

    Kitamoto, Katsuhiko

    2015-01-01

    Koji mold, Aspergillus oryzae, has been used for the production of sake, miso, and soy sauce for more than one thousand years in Japan. Due to the importance, A. oryzae has been designated as the national micro-organism of Japan (Koku-kin). A. oryzae has been intensively studied in the past century, with most investigations focusing on breeding techniques and developing methods for Koji making for sake brewing. However, the understanding of fundamental biology of A. oryzae remains relatively limited compared with the yeast Saccharomyces cerevisiae. Therefore, we have focused on studying the cell biology including live cell imaging of organelles, protein vesicular trafficking, autophagy, and Woronin body functions using the available genomic information. In this review, I describe essential findings of cell biology of A. oryzae obtained in our study for a quarter of century. Understanding of the basic biology will be critical for not its biotechnological application, but also for an understanding of the fundamental biology of other filamentous fungi.

  18. Crack Coalescence in Molded Gypsum and Carrara Marble

    Science.gov (United States)

    Wong, N.; Einstein, H. H.

    2007-12-01

    This research investigates the fracturing and coalescence behavior in prismatic laboratory-molded gypsum and Carrara marble specimens, which consist of either one or two pre-existing open flaws, under uniaxial compression. The tests are monitored by a high speed video system with a frame rate up to 24,000 frames/second. It allows one to precisely observe the cracking mechanisms, in particular if shear or tensile fracturing takes place. Seven crack types and nine crack coalescence categories are identified. The flaw inclination angle, the ligament length and the bridging angle between two flaws have different extents of influence on the coalescence patterns. For coplanar flaws, as the flaw inclination angle increases, there is a general trend of variation from shear coalescence to tensile coalescence. For stepped flaws, as the bridging angle changes from negative to small positive, and further up to large positive values, the coalescence generally progresses from categories of no coalescence, indirect coalescence to direct coalescence. For direct coalescence, it generally progresses from shear, mixed shear-tensile to tensile as the bridging angle increases. Some differences in fracturing and coalescence processes are observed in gypsum and marble, particularly the crack initiation in marble is preceded by the development of macroscopic white patches, but not in gypsum. Scanning Electron Microprobe (SEM) study reveals that the white patches consist of zones of microcracks (process zones).

  19. Characterization of curing behavior of UV-curable LSR for LED embedded injection mold

    Science.gov (United States)

    Tae, Joon-Sung; Yim, Kyung-Gyu; Rhee, Byung-Ohk; Kwak, Jae B.

    2016-11-01

    For many applications, liquid silicone rubber (LSR) injection molding is widely used for their great design flexibility and high productivity. In particular, a sealing part for a mobile device such as smartphone and watch has been produced by injection molding. While thermally curable LSR causes deformation problem due to a high mold temperature, UV-curable LSR can be molded at room temperature, which has advantages for over-molding with inserts of temperature-sensitive materials. Ultraviolet light-emitting diodes (UV LEDs) have advantages such as a longer service life, a lower heat dissipation, and smaller size to equip into the mold than conventional halogen or mercury UV lamps. In this work, rheological behavior of UV-curable LSR during curing process was analyzed by UV LEDs available in the market. UV-LEDs of various wave lengths and intensities were tested. The steady shear test was applied to find the starting time of curing and the SAOS was applied to find the ending time of curing to estimate processing time. In addition, the hardness change with irradiation energy was compared with the rheological data to confirm the reliability of the rheological test.

  20. The influence of microwave heating and water glass kind on the properties of molding sands

    Directory of Open Access Journals (Sweden)

    K. Granat

    2008-03-01

    Full Text Available This work presents rcsults of research on thc influcncc of microwave heating time on the process of hardening of warcr glass moldingsands. Essential influence of this drying process on basic properties such as: cornprcssion, bcnding mind tcnsitc strcng~h as well aspcrrneabili~y and war resistance, has bccn found. It has bccn proved, that at1 thc investigated sorts of sodium water glass could be uscd asbinding material of molding sands intended for curing with the microwave process healing. It has bccn found, while analyzing the rcsultsof property studics or microwavc heated molding sands with 2.5% addition of water glass, that aIl available on the markct kinds of thisbinding agent (inctuding the most frequently uscd in foundry 145 and 149 kinds after microwave heating guarantee very goodcompression, bending and tensile strength as well as permeability and wcar resistance. Moroovcr, it has bccn dctcrmined that the optimalcuring powcr of molding sands containing various kinds of water gIass is 560 W. AII values exceeding this rcsult in stabilization of basicpropcrtics of molding sands. The use of microwave curing of water glass molding sands results in a significant decrease of hardeningprocess time. full stabilization of molding sands as well as much lower energy consumption.

  1. Study on Improving Thickness Uniformity of Microfluidic Chip Mold in the Electroforming Process

    Directory of Open Access Journals (Sweden)

    Liqun Du

    2016-01-01

    Full Text Available Electroformed microfluidic chip mold faces the problem of uneven thickness, which decreases the dimensional accuracy of the mold, and increases the production cost. To fabricate a mold with uniform thickness, two methods are investigated. Firstly, experiments are carried out to study how the ultrasonic agitation affects the thickness uniformity of the mold. It is found that the thickness uniformity is maximally improved by about 30% after 2 h electroforming under 200 kHz and 500 W ultrasonic agitation. Secondly, adding a second cathode, a method suitable for long-time electroforming is studied by numerical simulation. The simulation results show that with a 4 mm width second cathode used, the thickness uniformity is improved by about 30% after 2 h of electroforming, and that with electroforming time extended, the thickness uniformity is improved more obviously. After 22 h electroforming, the thickness uniformity is increased by about 45%. Finally, by comparing two methods, the method of adding a second cathode is chosen, and a microfluidic chip mold is made with the help of a specially designed second cathode. The result shows that the thickness uniformity of the mold is increased by about 50%, which is in good agreement with the simulation results.

  2. 3D scanning based mold correction for planar and cylindrical parts in aluminum die casting

    Directory of Open Access Journals (Sweden)

    Takashi Seno

    2015-04-01

    Full Text Available Aluminum die casting is an important manufacturing process for mechanical components. Die casting is known to be more accurate than other types of casting; however, post-machining is usually necessary to achieve the required accuracy. The goal of this investigation is to develop machining- free aluminum die casting. Improvement of the accuracy of planar and cylindrical parts is expected by correcting metal molds. In the proposed method, the shape of cast aluminum made with the initial metal molds is measured by 3D scanning. The 3D scan data includes information about deformations that occur during casting. Therefore, it is possible to estimate the deformation and correction amounts by comparing 3D scan data with product computer-aided design (CAD data. We corrected planar and cylindrical parts of the CAD data for the mold. In addition, we corrected the planar part of the metal mold using the corrected mold data. The effectiveness of the proposed method is demonstrated by evaluating the accuracy improvement of the cast aluminum made with the corrected mold.

  3. A Modular, Reconfigurable Mold for a Soft Robotic Gripper Design Activity

    Directory of Open Access Journals (Sweden)

    Jiawei Zhang

    2017-09-01

    Full Text Available Soft robotics is an emerging field with strong potential to serve as an educational tool due to its advantages such as low costs and shallow learning curves. In this paper, we introduce a modular and reconfigurable mold for flexible design of pneumatic soft robotic grippers. By using simple assembly kits, students at all levels are able to design and construct soft robotic grippers that vary in function and performance. The process of constructing the modular mold enables students to understand how design choices impact system performance. Our unique modular mold allows students to select the number and length of fingers in a gripper, as well as to adjust the internal geometry of the pneumatic actuator cavity, which dictates how and where bending of a finger occurs. In addition, the mold may be deconstructed and reconfigured, which allows for fast iterative design and lowers material costs (since a new mold does not need to be made to implement a design change. We further demonstrate the feasibility of the modular mold by implementing it in a soft robot design activity in classrooms and showing a sufficiently high rate of student success in designing and constructing a functional soft robotic gripper.

  4. Underground processing method for radiation-contaminated material and transferring method for buffer molding material

    International Nuclear Information System (INIS)

    Akasaka, Hidenari; Shimura, Satoshi; Asano, Eiichi; Yamagata, Junji; Ninomiya, Nobuo; Kawakami, Susumu.

    1995-01-01

    A bottomed molding material (buffer molding material) is formed into a bottomed cylindrical shape by solidifying, under pressure, powders such as of bentonite into a highly dense state by a cold isotropic pressing or the like, having a hole for accepting and containing a vessel for radiation-contaminated materials. The bottomed cylindrical molding material is loaded on a transferring vessel, and transferred to a position near the site for underground disposal. The bottomed cylindrical molding material having a upwarded containing hole is buried in the cave for disposal. The container for radiation-contaminated material is loaded and contained in the containing hole of the bottomed cylindrical molding material. A next container for radiation-contaminated materials is juxtaposed thereover. Then, a bottomed cylindrical molding material having a downwarded containing hole is covered to the container for the radiation-contaminated material in a state being protruded upwardly. The radiation-contaminated material is thus closed by a buffer material of the same material at the circumference thereof. (I.N.)

  5. Amphibian embryo and parental defenses and a larval predator reduce egg mortality from water mold.

    Science.gov (United States)

    Gomez-Mestre, Ivan; Touchon, Justin C; Warkentin, Karen M

    2006-10-01

    Water molds attack aquatic eggs worldwide and have been associated with major mortality events in some cases, but typically only in association with additional stressors. We combined field observations and laboratory experiments to study egg stage defenses against pathogenic water mold in three temperate amphibians. Spotted salamanders (Ambystoma maculatum) wrap their eggs in a protective jelly layer that prevents mold from reaching the embryos. Wood frog (Rana sylvatica) egg masses have less jelly but are laid while ponds are still cold and mold growth is slow. American toad (Bufo americanus) eggs experience the highest infection levels. They are surrounded by thin jelly and are laid when ponds have warmed and mold grows rapidly. Eggs of all three species hatched early when infected, yielding smaller and less developed hatchlings. This response was strongest in B. americanus. Precocious hatching increased vulnerability of wood frog hatchlings to invertebrate predators. Finally, despite being potential toad hatchling predators, R. sylvatica tadpoles can have a positive effect on B. americanus eggs. They eat water mold off infected toad clutches, increasing their hatching success.

  6. Three-dimensional numerical simulation for plastic injection-compression molding

    Science.gov (United States)

    Zhang, Yun; Yu, Wenjie; Liang, Junjie; Lang, Jianlin; Li, Dequn

    2018-03-01

    Compared with conventional injection molding, injection-compression molding can mold optical parts with higher precision and lower flow residual stress. However, the melt flow process in a closed cavity becomes more complex because of the moving cavity boundary during compression and the nonlinear problems caused by non-Newtonian polymer melt. In this study, a 3D simulation method was developed for injection-compression molding. In this method, arbitrary Lagrangian- Eulerian was introduced to model the moving-boundary flow problem in the compression stage. The non-Newtonian characteristics and compressibility of the polymer melt were considered. The melt flow and pressure distribution in the cavity were investigated by using the proposed simulation method and compared with those of injection molding. Results reveal that the fountain flow effect becomes significant when the cavity thickness increases during compression. The back flow also plays an important role in the flow pattern and redistribution of cavity pressure. The discrepancy in pressures at different points along the flow path is complicated rather than monotonically decreased in injection molding.

  7. Structural materialization of stainless steel molds and dies by the low temperature high density plasma nitriding

    Directory of Open Access Journals (Sweden)

    Aizawa Tatsuhiko

    2015-01-01

    Full Text Available Various kinds of stainless steels have been widely utilized as a mold substrate material for injection molding and as a die for mold-stamping and direct stamping processes. Since they suffered from high temperature transients and thermal cycles in practice, they must be surface-treated by dry and wet coatings, or, by plasma nitriding. Martensitic stainless steel mold was first wet plated by the nickel phosphate (NiP, which was unstable at the high temperature stamping condition; and, was easy to crystalize or to fracture by itself. This issue of nuisance significantly lowered the productivity in fabrication of optical elements at present. In the present paper, the stainless steel mold was surface-treated by the low-temperature plasma nitriding. The nitrided layer by this surface modification had higher nitrogen solute content than 4 mass%; the maximum solid-solubility of nitrogen is usually 0.1 mass% in the equilibrium phase diagram. Owing to this solid-solution with high nitrogen concentration, the nitrided layer had high hardness of 1400 Hv within its thickness of 40 μm without any formation of nitrides after 14.4 ks plasma nitriding at 693 K. This nitrogen solid-solution treated stainless steel had thermal resistivity even at the mold-stamping conditions up to 900 K.

  8. An Impedance-Based Mold Sensor with on-Chip Optical Reference

    Directory of Open Access Journals (Sweden)

    Poornachandra Papireddy Vinayaka

    2016-09-01

    Full Text Available A new miniaturized sensor system with an internal optical reference for the detection of mold growth is presented. The sensor chip comprises a reaction chamber provided with a culture medium that promotes the growth of mold species from mold spores. The mold detection is performed by measuring impedance changes with integrated electrodes fabricated inside the reaction chamber. The impedance change in the culture medium is caused by shifts in the pH (i.e., from 5.5 to 8 as the mold grows. In order to determine the absolute pH value without the need for calibration, a methyl red indicator dye has been added to the culture medium. It changes the color of the medium as the pH passes specific values. This colorimetric principle now acts as a reference measurement. It also allows the sensitivity of the impedance sensor to be established in terms of impedance change per pH unit. Major mold species that are involved in the contamination of food, paper and indoor environments, like Fusarium oxysporum, Fusarium incarnatum, Eurotium amstelodami, Aspergillus penicillioides and Aspergillus restrictus, have been successfully analyzed on-chip.

  9. Sensory quality of Camembert-type cheese: Relationship between starter cultures and ripening molds.

    Science.gov (United States)

    Galli, Bruno Domingues; Martin, José Guilherme Prado; da Silva, Paula Porrelli Moreira; Porto, Ernani; Spoto, Marta Helena Fillet

    2016-10-03

    Starter cultures and ripening molds used in the manufacture of moldy cheese aimed at obtaining characteristic flavors and textures considerably differ among dairy industries. Thus, the study of variables inherent to the process and their influence on sensory patterns in cheese can improve the standardization and control of the production process. The aim of this work was to study the influence of three different variables on the sensory quality of Camembert-type cheese: type of lactic bacteria, type of ripener molds and inoculation method. Batches of Camembert-type cheese were produced using O or DL-type mesophilic starter culture, ripened with Penicillium camemberti or Penicillium candidum and mold inoculation was made directly into the milk or by spraying. All batches were sensorially evaluated using Quantitative Descriptive Analysis (QDA) with panelists trained for various attributes. Among the combinations analyzed, those resulting in more typical Camembert-type cheese were those using O-type mesophilic starter culture and P. candidum maturation mold directly applied into the milk or sprayed and those using DL-type mesophilic starter and P. camemberti ripener mold applied by surface spraying. These results demonstrate, therefore, that the combination of different ripener molds, inoculation methods and starter cultures directly influences the sensory quality of Camembert-type cheese, modifying significantly its texture, appearance, aroma and taste. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Optically transparent super-hydrophobic thin film fabricated by reusable polyurethane-acrylate (PUA) mold

    Science.gov (United States)

    Park, J.-S.; Park, J.-H.; Lee, D.-W.

    2018-02-01

    In this paper, we describe a simple manufacturing method for producing an optically transparent super-hydrophobic polymer thin film using a reusable photo-curable polymer mold. Soluble photoresist (PR) molds were prepared with under-exposed and under-baked processes, which created unique hierarchical micro/nano structures. The reverse phase of the PR mold was replicated on the surface of polydimethylsiloxane (PDMS) substrates. The unique patterns on the replicated PDMS molds were successfully transferred back to the UV curable polyurethane-acrylate (PUA) using a laboratory-made UV exposure system. Continuous production of the super-hydrophobic PDMS thin film was demonstrated using the reusable PUA mold. In addition, hydrophobic nano-silica powder was sprayed onto the micro/nano structured PDMS surfaces to further improve hydrophobicity. The fabricated PDMS thin films with hierarchical surface texturing showed a water contact angle  ⩾150°. Excellent optical transmittance within the range of visible light of wavelengths between 400-800 nm was experimentally confirmed using a spectrophotometer. High efficiency of the super-hydrophobic PDMS film in optical transparency was also confirmed using solar panels. The fabricated PUA molds are very suitable for use in roll-to-roll or roll-to-plate systems which allow continuous production of super-hydrophobic thin films with an excellent optical transparency.

  11. 40 CFR Table 3 to Subpart Wwww of... - Organic HAP Emissions Limits for Existing Open Molding Sources, New Open Molding Sources Emitting...

    Science.gov (United States)

    2010-07-01

    .../ton.4 Use the appropriate open molding emission limit.5 9. pultrusion 6 N/A reduce total organic HAP... CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic Composites...: If your operation type is . . . And you use . . . 1 Your organic HAP emissions limit is . . . 1. open...

  12. Injection molding simulation to improve the efficiency and quality of metal molding designs. Kanagata no sekkei koritsu ka to hinshitsu kojo wo hakaru shashutsu seikei simulation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Y. (Sony Corp., Tokyo (Japan))

    1992-01-01

    In order to improve the efficiency and quality of metal molding designs, Sony Corp. has adopted an injection molding simulation system since the first half of 1980s. Since, however, molding materials are thermal fluids, which transit their phase from liquid into solid, and boundary conditions will be changed in the middle of their cycles, their analyzing works are very difficult. Therefore, softwares in this field are still on the way to be developed. Since this corporation has joined to the Cornell Injection Molding Program (CIMP) project in Cornell University, they have added improvements on their programs to be supplied, and have used them with their own programs developed additionally based on transformation processes. They have carried out minimizing of shape of boss root and examining holding pressure control by this simulation system. Since actually input works for CAD process have been carried out by hand now, it takes a time a little, though, they have also considered to make it easy by automating for applications of the full model. 4 refs., 7 figs.

  13. Family and home characteristics correlate with mold in homes.

    Science.gov (United States)

    Reponen, Tiina; Levin, Linda; Zheng, Shu; Vesper, Stephen; Ryan, Patrick; Grinshpun, Sergey A; LeMasters, Grace

    2013-07-01

    Previously, we demonstrated that infants residing in homes with higher Environmental Relative Moldiness Index were at greater risk for developing asthma by age seven. The purpose of this analysis was to identify the family and home characteristics associated with higher moldiness index values in infants' homes at age one. Univariate linear regression of each characteristic determined that family factors associated with moldiness index were race and income. Home characteristics associated with the moldiness index values were: air conditioning, carpet, age of the home, season of home assessment, and house dust mite allergen. Parental history of asthma, use of dehumidifier, visible mold, dog and cat allergen levels were not associated with moldiness index. Results of multiple linear regression showed that older homes had 2.9 units higher moldiness index (95% confidence interval [CI]=0.4, 5.4), whereas homes with central air conditioning had 2.5 units lower moldiness index (95% CI=-4.7, -0.4). In addition, higher dust mite allergen levels and carpeting were positively and negatively associated with higher moldiness index, respectively. Because older homes and lack of air conditioning were also correlated with race and lower income, whereas carpeting was associated with newer homes, the multivariate analyses suggests that lower overall socioeconomic position is associated with higher moldiness index values. This may lead to increased asthma risk in homes inhabited by susceptible, vulnerable population subgroups. Further, age of the home was a surrogate of income, race and carpeting in our population; thus the use of these factors should carefully be evaluated in future studies. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Improved compression molding technology for continuous fiber reinforced composite laminates. Part 2: AS-4/Polyimidesulfone prepreg system

    Science.gov (United States)

    Baucom, Robert M.; Hou, Tan-Hung; Kidder, Paul W.; Reddy, Rakasi M.

    1991-01-01

    AS-4/polyimidesulfone (PISO2) composite prepreg was utilized for the improved compression molding technology investigation. This improved technique employed molding stops which advantageously facilitate the escape of volatile by-products during the B-stage curing step, and effectively minimize the neutralization of the consolidating pressure by intimate interply fiber-fiber contact within the laminate in the subsequent molding cycle. Without the modifying the resin matrix properties, composite panels with both unidirectional and angled plies with outstanding C-scans and mechanical properties were successfully molded using moderate molding conditions, i.e., 660 F and 500 psi, using this technique. The size of the panels molded were up to 6.00 x 6.00 x 0.07 in. A consolidation theory was proposed for the understanding and advancement of the processing science. Processing parameters such as vacuum, pressure cycle design, prepreg quality, etc. were explored.

  15. Prevalence of Residential Dampness and Mold Exposure in a University Student Population

    Directory of Open Access Journals (Sweden)

    Mathieu Lanthier-Veilleux

    2016-02-01

    Full Text Available The impact of residential dampness or mold on respiratory health is well established but few studies have focused on university students. This study aims to: (a describe the prevalence of exposure to residential dampness or mold in university students according to socio-geographic factors and (b identify associated housing characteristics. A web survey was conducted in 2014 among the 26,676 students registered at the Université de Sherbrooke (QC, Canada. Residential dampness and mold being closely intertwined, they were considered as a single exposure and assessed using a validated questionnaire. Exposure was compared according to socio-geographic and housing characteristics using chi-square tests and logistic regressions. Among the 2097 participants included in the study (response rate: 8.1%, over 80% were tenants. Residential exposure to dampness or mold was frequent (36.0%, 95% CI: 33.9–38.1. Marked differences for this exposure were noted according to home ownership (39.7% vs. 25.5% among tenants and owners respectively; OR = 1.92%, 95% CI: 1.54–2.38. Campus affiliation, household composition and the number of residents per building were associated with exposure to dampness or mold (p < 0.01, while sex and age were not. Exposure was also associated with older buildings, and buildings in need of renovations and lacking proper ventilation (p < 0.001. This study highlights the potential risk of university students suffering from mold-related health effects given their frequent exposure to this agent. Further research is needed to fully evaluate the mold-related health impact in this at risk group.

  16. Glass molding of 3mm diameter aspheric plano-convex lens

    Science.gov (United States)

    Sung, Hayeong; Hue, Myung sang; Lee, Giljae; Ryu, Geunman; Kim, Dongguk; Yang, Suncheol

    2017-10-01

    The many industries and research fields have demands for small scale optical systems. To satisfy the demands, many studies are conducted and the miniaturization technologies have been developed. The optical lens is directly related to the optical systems and a key component for the miniaturization. So the aspheric surface which can replace multispherical lenses is applied to the optical lens. And fabrication methods to reduce the diameter of the lens have been developed. The glass molding pressing (GMP) process is an attractive method to fabricate aspheric lens among the lens manufacturing processes. Because the GMP process has advantages of productivity, repeatability and so on. In this study, a 3 mm diameter aspheric plano-convex lens was fabricated using the GMP process. The GMP process was divided into heating, pressing, annealing and cooling. And the process was conducted using a commercial glass molding machine. Mold tools consist of an upper and a lower mold insert, an inner and an outer guide. The aspheric and the flat surfaces of the mold inserts were coated with ta-C to prevent the sticking of the glass to the mold. The surfaces of molded lens were measured by white interferometry and surface profilometer. The height and the diameter were measured using optical microscopy. As results, the aspheric surface of the lens was 5.1187 nm in Ra and 0.242 um in Pt. And the flat surface was 2.6697 nm in Ra and 0.13 um in Pt. The height and the diameter were 1.935 mm and 3.002 mm respectively.

  17. Comparison of New and Traditional Culture-Dependent Media for Enumerating Foodborne Yeasts and Molds.

    Science.gov (United States)

    Beuchat, Larry R; Mann, David A

    2016-01-01

    Fifty-six foods and food ingredients were analyzed for populations of naturally occurring yeasts and molds using Petrifilm rapid yeast and mold (RYM) count plates, Petrifilm yeast and mold (YM) count plates, dichloran rose bengal chloramphenicol (DRBC) agar plates, acidified potato dextrose agar (APDA) plates, and dichloran 18% glycerol (DG18) agar plates. Colonies were counted after incubating plates for 48, 72, and 120 h at 25°C. Of 56 foods in which either yeasts or molds were detected on at least one medium incubated for 120 h, neither yeasts nor molds were detected in 55.4, 73.2, 21.4, 19.6, and 71.4% of foods plated on the five respective media and incubated for 48 h; 10.7, 14.3, 3.6, 1.8, and 19.6% of foods were negative after 72 h, and 3.6, 1.8, 0, 0, and 0% of foods were negative after 120 h. Considering all enumeration media, correlation coefficients were 0.03 to 0.97 at 48 h of incubation; these values increased to 0.75 to 0.99 at 120 h. Coefficients of variation for total yeasts and molds were as high as 30.0, 30.8, and 27.2% at 48, 72, and 120 h, respectively. The general order of performance was DRBC = APDA > RYM Petrifilm > YM Petrifilm ≥ DG18 when plates were incubated for 48 h, DRBC > APDA > RYM Petrifilm > YM Petrifilm ≥ DG18 when plates were incubated for 72 h, and DRBC > APDA > RYM Petrifilm > YM Petrifilm > DG18 when plates were incubated for 120 h. Differences in performance among media are attributed to the diversity of yeasts and molds likely to be present in test foods and differences in nutrient, pH, and water activity requirements for resuscitation of stressed cells and colony development.

  18. Characterization of Ni–Cr alloys using different casting techniques and molds

    International Nuclear Information System (INIS)

    Chen, Wen-Cheng; Teng, Fu-Yuan; Hung, Chun-Cheng

    2014-01-01

    This study differentiated the mechanical properties of nickel–chromium (Ni–Cr) alloys under various casting techniques (different casting molds and casting atmospheres). These techniques were sampled by a sand mold using a centrifugal machine in ambient air (group I) and electromagnetic induction in an automatic argon castimatic casting machine (group II). The specimen casting used a graphite mold by a castimatic casting machine (group III). The characteristics of the Ni–Cr alloys, yield and ultimate tensile strength, bending modulus, microhardness, diffraction phase, grindability, ability to spring back, as well as ground microstructure and pattern under different casting conditions were evaluated. The group III specimens exhibited the highest values in terms of strength, modulus, hardness, and grindability at a grind rate of 500 rpm. Moreover, group III alloys exhibited smaller grain sizes, higher ability to spring back, and greater ductility than those casted by sand investment (groups I and II). The main factor, “casting mold,” significantly influenced all mechanical properties. The graphite mold casting of the Ni–Cr dental alloys in a controlled atmosphere argon casting system provided an excellent combination of high mechanical properties and good ability to spring back, and preserved the ductile properties for application in Ni–Cr porcelain-fused system. The results can offer recommendations to assist a prosthetic technician in selecting the appropriate casting techniques to obtain the desired alloy properties. - Highlights: • Properties of Ni–Cr alloys using various casting techniques are characterized. • Alloys cast by graphite mold exhibited higher recovery angle and more ductility. • Alloys cast by graphite mold exhibited higher strength and grinding rate. • Alloys in this study increase operative room to adjust the precision for prosthesis

  19. Increasing the resistance of common bean to white mold through recurrent selection

    Directory of Open Access Journals (Sweden)

    Monik Evelin Leite

    2016-02-01

    Full Text Available ABSTRACT White mold, caused by Sclerotinea sclerotiorum (Lib. de Bary is one of the most important diseases of the common bean (Phaseolus vulgaris L. worldwide. Physiological resistance and traits related to disease avoidance such as architecture contribute to field resistance. The aim of this study was to verify the efficiency of recurrent selection in physiological resistance to white mold, “Carioca” grain type and upright habit in common bean. Thirteen common bean lines with partial resistance to white mold were intercrossed by means of a circulant diallel table, and seven recurrent selection cycles were obtained. Of these cycles, progenies of the S0:1, S0:2 and S0:3 generations of cycles III, IV, V and VI were evaluated. The best (8 to 10 progenies of the seven cycles were also evaluated, in two experiments, one in the greenhouse and one in the field. Lattice and/or randomized block experimental designs were used. The traits evaluated were: resistance to white mold by the straw test method, growth habit and grain type. The most resistant progenies were selected based on the average score of resistance to white mold. Subsequently, they were evaluated with regard to grain type and growth habit. Recurrent selection allowed for genetic progress of about 11 % per year for white mold resistance and about 15 % per year for the plant architecture. There was no gain among cycles for grain type. Progeny selection and recurrent selection were efficient for obtaining progenies with a high level of resistance to white mold with “Carioca” grain type and upright habit.

  20. Wetting Behavior of Mold Flux Droplet on Steel Substrate With or Without Interfacial Reaction

    Science.gov (United States)

    Zhou, Lejun; Li, Jingwen; Wang, Wanlin; Sohn, Il

    2017-08-01

    The slag entrapment in mold tends to cause severe defects on the slab surface, especially for casting steels containing active alloy elements such as Al, Ti, and Mn. The wetting behavior of molten mold flux on the initial solidified shell is considered to be a key factor to determine the entrapment of mold slag on the shell surface. Therefore, the wetting behavior of mold flux droplet on the steel substrate with or without interfacial reaction was investigated by the sessile drop method. The results indicated that the melting process of mold flux has a significant influence on the variation of contact angle, and the final contact angle for Flux1 droplet on 20Mn23AlV is only 15 deg, which is lower than the other two cases due to the intensive interracial reactions occurring in this case. In addition, the thickness of the interaction layer for the case of Flux1 on 20Mn23AlV is 10- μm greater than the other two cases, which confirms that the most intensive reactions occurred at the interface area. The microstructure and element distribution at the interface analyzed by a scanning electron microscope (SEM) and energy dispersive spectrum (EDS) suggested that the increase of wettability of mold flux droplet on the steel substrate is caused by the migration of Al, Mn, and Si elements occurring in the vicinity of the interface. The results obtained in this article can reveal the mechanism of flux entrapment by hook or shell and provide theoretic guidance for mold flux design and optimization.

  1. Characterization of Ni–Cr alloys using different casting techniques and molds

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wen-Cheng, E-mail: wencchen@fcu.edu.tw [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Teng, Fu-Yuan [Department of Dentistry, Kaohsiung Armed Forces General Hospital, Kaohsiung 802, Taiwan (China); School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Hung, Chun-Cheng [School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan (China)

    2014-02-01

    This study differentiated the mechanical properties of nickel–chromium (Ni–Cr) alloys under various casting techniques (different casting molds and casting atmospheres). These techniques were sampled by a sand mold using a centrifugal machine in ambient air (group I) and electromagnetic induction in an automatic argon castimatic casting machine (group II). The specimen casting used a graphite mold by a castimatic casting machine (group III). The characteristics of the Ni–Cr alloys, yield and ultimate tensile strength, bending modulus, microhardness, diffraction phase, grindability, ability to spring back, as well as ground microstructure and pattern under different casting conditions were evaluated. The group III specimens exhibited the highest values in terms of strength, modulus, hardness, and grindability at a grind rate of 500 rpm. Moreover, group III alloys exhibited smaller grain sizes, higher ability to spring back, and greater ductility than those casted by sand investment (groups I and II). The main factor, “casting mold,” significantly influenced all mechanical properties. The graphite mold casting of the Ni–Cr dental alloys in a controlled atmosphere argon casting system provided an excellent combination of high mechanical properties and good ability to spring back, and preserved the ductile properties for application in Ni–Cr porcelain-fused system. The results can offer recommendations to assist a prosthetic technician in selecting the appropriate casting techniques to obtain the desired alloy properties. - Highlights: • Properties of Ni–Cr alloys using various casting techniques are characterized. • Alloys cast by graphite mold exhibited higher recovery angle and more ductility. • Alloys cast by graphite mold exhibited higher strength and grinding rate. • Alloys in this study increase operative room to adjust the precision for prosthesis.

  2. Effect of reinforcement amount, mold temperature, superheat, and mold thickness on fluidity of in-situ Al-Mg2Si composites

    Directory of Open Access Journals (Sweden)

    Reza Vatankhah Barenji

    2018-01-01

    Full Text Available In the present study, the effects of mold temperature, superheat, mold thickness, and Mg2Si amount on the fluidity of the Al-Mg2Si as-cast in-situ composites were investigated using the mathematical models. Composites with different amounts of Mg2Si were fabricated, and the fluidity and microstructure of each were then analyzed. For this purpose, the experiments were designed using a central composite rotatable design, and the relationship between parameters and fluidity were developed using the response surface method. In addition, optical and scanning electron microscopes were used for microstructural observation. The ANOVA shows that the mathematical models can predict the fluidity accurately. The results show that by increasing the mold temperature from 25 °C to 200 °C, superheat from 50 °C to 250 °C, and thickness from 3 mm to 12 mm, the fluidity of the composites decreases, where the mold thickness is more effective than other factors. In addition, the higher amounts of Mg2Si in the range from 15wt.% to 25wt.% lead to the lower fluidity of the composites. For example, when the mold temperature, superheat, and thickness are respectively 100 °C, 150 °C, and 7 mm, the fluidity length is changed in the range of 11.9 cm to 15.3 cm. By increasing the amount of Mg2Si, the morphology of the primary Mg2Si becomes irregular and the size of primary Mg2Si is increased. Moreover, the change of solidification mode from skin to pasty mode is the most noticeable microstructural effect on the fluidity.

  3. Method for compression molding of thermosetting plastics utilizing a temperature gradient across the plastic to cure the article

    Science.gov (United States)

    Heier, W. C. (Inventor)

    1974-01-01

    A method is described for compression molding of thermosetting plastics composition. Heat is applied to the compressed load in a mold cavity and adjusted to hold molding temperature at the interface of the cavity surface and the compressed compound to produce a thermal front. This thermal front advances into the evacuated compound at mean right angles to the compression load and toward a thermal fence formed at the opposite surface of the compressed compound.

  4. The Design of 3D-Printed Lattice-Reinforced Thickness-Varying Shell Molds for Castings.

    Science.gov (United States)

    Shangguan, Haolong; Kang, Jinwu; Yi, Jihao; Zhang, Xiaochuan; Wang, Xiang; Wang, Haibin; Huang, Tao

    2018-03-30

    3D printing technologies have been used gradually for the fabrication of sand molds and cores for castings, even though these molds and cores are dense structures. In this paper, a generation method for lattice-reinforced thickness-varying shell molds is proposed and presented. The first step is the discretization of the STL (Stereo Lithography) model of a casting into finite difference meshes. After this, a shell is formed by surrounding the casting with varying thickness, which is roughly proportional to the surface temperature distribution of the casting that is acquired by virtually cooling it in the environment. A regular lattice is subsequently constructed to support the shell. The outside surface of the shell and lattice in the cubic mesh format is then converted to STL format to serve as the external surface of the new shell mold. The internal surface of the new mold is the casting's surface with the normals of all of the triangles in STL format reversed. Experimental verification was performed on an Al alloy wheel hub casting. Its lattice-reinforced thickness-varying shell mold was generated by the proposed method and fabricated by the binder jetting 3D printing. The poured wheel hub casting was sound and of good surface smoothness. The cooling rate of the wheel hub casting was greatly increased due to the shell mold structure. This lattice-reinforced thickness-varying shell mold generation method is of great significance for mold design for castings to achieve cooling control.

  5. Fabrication of combined-scale nano- and microfluidic polymer systems using a multilevel dry etching, electroplating and molding process

    DEFF Research Database (Denmark)

    Tanzi, Simone; Østergaard, Peter Friis; Matteucci, Marco

    2012-01-01

    Microfabricated single-cell capture and DNA stretching devices have been produced by injection molding. The fabrication scheme employed deep reactive ion etching in a silicon substrate, electroplating in nickel and molding in cyclic olefin polymer. This work proposes technical solutions to fabric......Microfabricated single-cell capture and DNA stretching devices have been produced by injection molding. The fabrication scheme employed deep reactive ion etching in a silicon substrate, electroplating in nickel and molding in cyclic olefin polymer. This work proposes technical solutions...

  6. The Design of 3D-Printed Lattice-Reinforced Thickness-Varying Shell Molds for Castings

    Science.gov (United States)

    Shangguan, Haolong; Kang, Jinwu; Yi, Jihao; Zhang, Xiaochuan; Wang, Xiang; Wang, Haibin; Huang, Tao

    2018-01-01

    3D printing technologies have been used gradually for the fabrication of sand molds and cores for castings, even though these molds and cores are dense structures. In this paper, a generation method for lattice-reinforced thickness-varying shell molds is proposed and presented. The first step is the discretization of the STL (Stereo Lithography) model of a casting into finite difference meshes. After this, a shell is formed by surrounding the casting with varying thickness, which is roughly proportional to the surface temperature distribution of the casting that is acquired by virtually cooling it in the environment. A regular lattice is subsequently constructed to support the shell. The outside surface of the shell and lattice in the cubic mesh format is then converted to STL format to serve as the external surface of the new shell mold. The internal surface of the new mold is the casting’s surface with the normals of all of the triangles in STL format reversed. Experimental verification was performed on an Al alloy wheel hub casting. Its lattice-reinforced thickness-varying shell mold was generated by the proposed method and fabricated by the binder jetting 3D printing. The poured wheel hub casting was sound and of good surface smoothness. The cooling rate of the wheel hub casting was greatly increased due to the shell mold structure. This lattice-reinforced thickness-varying shell mold generation method is of great significance for mold design for castings to achieve cooling control. PMID:29601543

  7. The Design of 3D-Printed Lattice-Reinforced Thickness-Varying Shell Molds for Castings

    Directory of Open Access Journals (Sweden)

    Haolong Shangguan

    2018-03-01

    Full Text Available 3D printing technologies have been used gradually for the fabrication of sand molds and cores for castings, even though these molds and cores are dense structures. In this paper, a generation method for lattice-reinforced thickness-varying shell molds is proposed and presented. The first step is the discretization of the STL (Stereo Lithography model of a casting into finite difference meshes. After this, a shell is formed by surrounding the casting with varying thickness, which is roughly proportional to the surface temperature distribution of the casting that is acquired by virtually cooling it in the environment. A regular lattice is subsequently constructed to support the shell. The outside surface of the shell and lattice in the cubic mesh format is then converted to STL format to serve as the external surface of the new shell mold. The internal surface of the new mold is the casting’s surface with the normals of all of the triangles in STL format reversed. Experimental verification was performed on an Al alloy wheel hub casting. Its lattice-reinforced thickness-varying shell mold was generated by the proposed method and fabricated by the binder jetting 3D printing. The poured wheel hub casting was sound and of good surface smoothness. The cooling rate of the wheel hub casting was greatly increased due to the shell mold structure. This lattice-reinforced thickness-varying shell mold generation method is of great significance for mold design for castings to achieve cooling control.

  8. RANCANG BANGUN MOLD UNTUK PROSES TERMOFORMING PROSTHETIC BELOW KNEE (B/K

    Directory of Open Access Journals (Sweden)

    Bambang Waluyo Febriantoko

    2017-10-01

    ABSTRACT   The growing of industry has the effect to the increase of plastic need.  However, the application of plastic forming process often experiences constraints. One of them is depreciation. Depreciation often occurs in the plastic forming process, especially forming with mechanical thermoforming system. So it is necessary to analyze the things that cause shrinkage on the product. Some of the things that are identified to influence the shrinkage are the molds, temperatures and types of used plastics. The used method is to make mechanical thermoforming test and make mold which will be used to analyze depreciation. There are 2 kinds of molds, namely upper foot sole mold and bottom foot sole mold. In addition to the variations of the mold, the analysis is also aimed at the temperature of polypropylene plastic (PP and PVC plastic which will be processed. The temperature variations are 1000C, 1200C and 140oC and the types of plastics that are tested is polypropylene plastic (PP and PVC plastic. The results show that on mechanical thermoforming process for polypropylene (PP plastic with 1.0 mm thickness, the percentage of shrinkage can not be analyzed because of the low viscous nature of plastic. PP type plastic can form a pattern, but not perfect. PP plastic material does not experience a good expansion after pressing process with 100ºC-120ºC plastic temperature. This is because the plastic is still elastic. At 140ºC, the plastic undergoes expansion, but when the plastic pressing process, it undergoes an imperfect pattern. The reason is the temperature is too high. Meanwhile for the PVC plastic, it was found that in the upper foot sole mold with height of 2 cm and 1.0 mm plastic thickness, the percentages of shrinkage average are 7.85% with temperature 100ºC, 9.80% with temperature 120ºC and 12.11% with temperature of 140ºC. In the bottom foot sole mold with 2 cm height and 1.0 mm plastic thickness, the percentages of shrinkage average are 10.01% with

  9. Anti-sticking behavior of DLC-coated silicon micro-molds

    International Nuclear Information System (INIS)

    Saha, B; Tor, S B; Liu, E; Khun, N W; Hardt, D E; Chun, J H

    2009-01-01

    Pure carbon- (C), nitrogen- (N) and titanium- (Ti) doped diamond-like carbon (DLC) coatings were deposited on silicon (Si) micro-molds by dc magnetron sputtering deposition to improve the tribological performance of the micro-molds. The coated and uncoated Si molds were used in injection molding for the fabrication of secondary metal-molds, which were used for the replication of micro-fluidic devices. The bonding structure, surface roughness, surface energy, critical load and friction coefficient of the DLC coatings were characterized with micro-Raman spectroscopy, atomic force microscopy (AFM), contact angle, microscratch and ball-on-disc sliding wear tests, respectively. It was observed that the doping conditions had significant effects on Raman peak positions, mechanical and tribological properties of the coatings. The G peak shifted toward a lower position with N and Ti doping. The DLC coating deposited with 1 sccm N 2 flow rate showed the lowest G peak position and the smoothest surface. The surface energies of the pure carbon and Ti-doped DLC coatings were lower than that of the N-doped DLC, which was more significant at a higher N 2 flow rate. In terms of adhesion and friction coefficient, it was observed that the Ti-doped DLC coating had the best performance. Ti incorporated in the DLC coating decreased the residual stress of the coating, which improved the adhesive strength of the coating with the Si substrate

  10. Dense vertical SU-8 microneedles drawn from a heated mold with precisely controlled volume

    International Nuclear Information System (INIS)

    Xiang, Zhuolin; Wang, Hao; Yen, Shih-Cheng; Lee, Chengkuo; Murugappan, Suresh Kanna; Pastorin, Giorgia

    2015-01-01

    Drawing lithography technology has recently become a popular technique to fabricate (3D) microneedles. The conventional drawing process shows some limitations in fabricating dense, scale-up and small microneedles. In this study, we demonstrate a new drawing lithography process from a self-loading mold which is able to overcome these challenges. Different from the conventional molds which have difficult alignment and loading issues, a released SU-8 membrane is attached onto a SU-8 coated wafer to generate an innovative self-loading mold. The physically distinct SU-8 colloid in this mold successfully avoids the merging of the microneedle tips in the drawing process. Meanwhile, the same SU-8 colloid in mold can provide microneedles with uniform lengths on a large surface area. Furthermore, a low temperature drawing process with this improved technique prevents sharp tips from bending during the solidification stage. Remarkably, this new drawing lithography technology can fabricate microneedles with various lengths and they are strong enough to penetrate the outermost skin layer, namely the stratum corneum. The spacing between two adjacent microneedles is optimized to maximize the penetration rate through the skin. Histology images and drug diffusion testing demonstrate that microchannels are successfully created and the drugs can permeate the tissue under the skin. The fabricated microneedles are demonstrated to deliver insulin in vivo and lower blood glucose levels, suggesting future possible applications for minimally invasive transdermal delivery of macromolecules. (paper)

  11. Electron beam radiation of dried fruits and nuts to reduce yeast and mold bioburden.

    Science.gov (United States)

    Ic, Erhan; Kottapalli, Bala; Maxim, Joseph; Pillai, Suresh D

    2007-04-01

    Dried fruits and nuts make up a significant portion of the commodities traded globally, and the presence of yeasts and molds on dried fruits and nuts can be a public health risk because of the potential for exposure to toxigenic fungi. Since current postharvest treatment technologies are rather limited for dried fruits and nuts, electron beam (E-beam) radiation experiments were performed to determine the doses required to reduce the yeast and mold bioburden of raisins, walnuts, and dates. The indigenous yeast and mold bioburden on a select number of commodities sold at retail ranged from 10(2) to 10(3) CFU/g. E-beam inactivation kinetics based on the linear model suggest that the decimal reduction dose required to eliminate 90% of the microbial population (D10-value) of these indigenous fungal populations ranges from 1.09 to 1.59 kGy. Some samples, however, exhibited inactivation kinetics that were better modeled by a quadratic model. The results indicate that different commodities can contain molds and yeasts of varying resistance to ionizing radiation. It is thus essential for the dried fruit and nut industry to determine empirically the minimum E-beam dose that is capable of reducing or eliminating the bioburden of yeasts and molds in their specific commodities.

  12. Electrical and dielectric properties of foam injection-molded polypropylene/multiwalled carbon nanotube composites

    Energy Technology Data Exchange (ETDEWEB)

    Ameli, A.; Nofar, M.; Saniei, M.; Hossieny, N.; Park, C. B. [Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, Ontario, Canada M5S 3G8 (Canada); Pötschke, P. [Leibniz-Institut für Polymerforschung Dresden e.V. (IPF), Hohe Strasse 6, D-01069 Dresden (Germany)

    2015-05-22

    A combination of high dielectric permittivity (ε′) and low dielectric loss (tan δ) is required for charge storage applications. In percolative systems such as conductive polymer composites, however, obtaining high ε′ and low tan δ is very challenging due to the sharp insulation-conduction transition near the threshold region. Due to the particular arrangement of conductive fillers induced by both foaming and injection molding processes, they may address this issue. Therefore, this work evaluates the application of foam injection molding process in fabricating polymer nanocomposites for energy storage. Polypropylene-multiwalled carbon nanotubes (PP-MWCNT) composites were prepared by melt mixing and foamed in an injection molding process. Electrical conductivity (σ), ε′ and tan δ were then characterized. Also, scanning and transmission electron microscopy (SEM and TEM) was used to investigate the carbon nanotube’s arrangement as well as cellular morphology. The results showed that foam injection-molded composites exhibited highly superior dielectric properties to those of solid counterparts. For instance, foamed samples had ε′=68.3 and tan δ =0.05 (at 1.25 vol.% MWCNT), as opposed to ε′=17.8 and tan δ=0.04 in solid samples (at 2.56 vol.% MWCNT). The results of this work reveal that high performance dielectric nanocomposites can be developed using foam injection molding technologies for charge storage applications.

  13. Micro-ball lens structure fabrication based on drop on demand printing the liquid mold

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaoyang, E-mail: zhuxy1026@163.com; Zhu, Li, E-mail: zhuli@njust.edu.cn; Chen, Hejuan; Yang, Lijun; Zhang, Weiyi

    2016-01-15

    Graphical abstract: - Highlights: • The glycerol micro-ball droplet was introduced to be as liquid mold to fabricate micro-ball lens. • A molding process was used to fabricate the micro-ball lens and the scales of them can be controlled. • The accurate molding process is mainly attributed to the ultrahigh adhesion of the treated substrate. • The micro-ball lenses with contact angle of 120° and 150° were fabricated, analyzed and discussed. - Abstract: In this paper, we demonstrated a simple micro-ball lens array (MBLA) fabrication method using a drop-on-demand (DOD) droplet printing technique and liquid mold. The micro-ball droplet array on the hydrophobic surface is used as the liquid mold to fabricate the MBLA. The ultrahigh adhesion force between the micro-ball droplet and the substrate is ascribed to the Wenzel state of the micro-ball droplet, while the replication process with low position error is attributed to the ultrahigh adhesion force between the micro-ball droplet and the substrate and the high viscosity of the micro-ball droplet and polydimethylsiloxane (PDMS) liquid. The micro-ball lenses (MBLs) with a contact angle of 120° and 150° were fabricated and the important fabrication details were discussed. The optical performance and scanning electron microscope (SEM) data of the MBLs showed that the MBLs had high quality surface morphology and good optical performance.

  14. Gas-Assisted Heating Technology for High Aspect Ratio Microstructure Injection Molding

    Directory of Open Access Journals (Sweden)

    Shia-Chung Chen

    2013-01-01

    Full Text Available A hot gas is used for heating the cavity surface of a mold. Different mold gap sizes were designed. The mold surface temperature was heated to above the glass transition temperature of the plastic material, and the mold then closed for melt filling. The cavity surface can be heated to 130°C to assist the melt filling of the microfeatures. Results show that hot gas heating can improve the filling process and achieve 91% of the high aspect ratio microgrooves (about 640.38 μm of the maximum of 700 μm. The mold gap size strongly affects the heating speed and heating uniformity. Without surface preheating, the center rib is the highest. When the heating target temperature is 90°C or 100°C, the three microribs have a good uniformity of height. However, when the target temperature exceeds 100°C, the left side rib is higher than the other ribs.

  15. Analysis of Deformation and Equivalent Stress during Biomass Material Compression Molding

    Science.gov (United States)

    Xu, Guiying; Wei, Hetao; Zhang, Zhien; Yu, Shaohui; Wang, Congzhe; Huang, Guowen

    2018-02-01

    Ansys is adopted to analyze mold deformation and stress field distribution rule during the process of compressing biomass under pressure of 20Mpa. By means of unit selection, material property setting, mesh partition, contact pair establishment, load and constraint applying, and solver setting, the stress and strain of overall mold are analyzed. Deformation and equivalent Stress of compression structure, base, mold, and compression bar were analyzed. We can have conclusions: The distribution of stress forced on compressor is not completely uniform, where the stress at base is slightly decreased; the stress and strain of compression bar is the largest, and stress concentration my occur at top of compression bar, which goes against compression bar service life; the overall deformation of main mold is smaller; although there is slight difference between upper and lower part, the overall variation is not obvious, but the stress difference between upper and lower part of main mold is extremely large so that reaches to 10 times; the stress and strain in base decrease in circular shape, but there is still stress concentration in ledge, which goes against service life; contact stress does not distribute uniformly, there is increasing or decreasing trend in adjacent parts, which is very large in some parts. in constructing both.

  16. Surface Quality Improvement of AA6060 Aluminum Extruded Components through Liquid Nitrogen Mold Cooling

    Directory of Open Access Journals (Sweden)

    Andrea Francesco Ciuffini

    2018-06-01

    Full Text Available 6xxx aluminum alloys are suitable for the realization of both structural applications and architectural decorative elements, thanks to the combination of high corrosion resistance and good surface finish. In areas where the aesthetic aspects are fundamental, further improvements in surface quality are significant. The cooling of the extrusion mold via internal liquid nitrogen fluxes is emerging as an important innovation in aluminum extrusion. Nowadays, this innovation is providing a large-scale solution to obtain high quality surface finishes in extruded aluminum semi-finished products. These results are also coupled to a significant increase in productivity. The aim of the work is to compare the surface quality of both cooled liquid nitrogen molds and classically extruded products. In this work, adhesion phenomena, occurring during the extrusion between the mold and the flowing material, have been detected as the main causes of the presence of surface defects. The analysis also highlighted a strong increase in the surface quality whenever the extrusion mold was cooled with liquid nitrogen fluxes. This improvement has further been confirmed by an analysis performed on the finished products, after painting and chromium plating. This work on the AA6060 alloy has moreover proceeded to roughness measurements and metallographic analyses, to investigate the eventual occurrence of other possible benefits stemming from this new extrusion mold cooling technology.

  17. Finite element analysis and simulation of rheological properties of bulk molding compound (BMC)

    Science.gov (United States)

    Ergin, M. Fatih; Aydin, Ismail

    2013-12-01

    Bulk molding compound (BMC) is one of the important composite materials with various engineering applications. BMC is a thermoset plastic resin blend of various inert fillers, fiber reinforcements, catalysts, stabilizers and pigments that form a viscous, molding compound. Depending on the end-use application, bulk molding compounds are formulated to achieve close dimensional control, flame and scratch resistance, electrical insulation, corrosion and stain resistance, superior mechanical properties, low shrink and color stability. Its excellent flow characteristics, dielectric properties, and flame resistance make this thermoset material well-suited to a wide variety of applications requiring precision in detail and dimensions as well as high performance. When a BMC is used for these purposes, the rheological behavior and properties of the BMC is the main concern. In this paper, finite element analysis of rheological properties of bulk molding composite material was studied. For this purpose, standard samples of composite material were obtained by means of uniaxial hot pressing. 3 point flexural tests were then carried out by using a universal testing machine. Finite element analyses were then performed with defined material properties within a specific constitutive material behavior. Experimental and numerical results were then compared. Good correlation between the numerical simulation and the experimental results was obtained. It was expected with this study that effects of various process parameters and boundary conditions on the rheological behavior of bulk molding compounds could be determined by means of numerical analysis without detailed experimental work.

  18. Characterization of Ni-Cr alloys using different casting techniques and molds.

    Science.gov (United States)

    Chen, Wen-Cheng; Teng, Fu-Yuan; Hung, Chun-Cheng

    2014-02-01

    This study differentiated the mechanical properties of nickel-chromium (Ni-Cr) alloys under various casting techniques (different casting molds and casting atmospheres). These techniques were sampled by a sand mold using a centrifugal machine in ambient air (group I) and electromagnetic induction in an automatic argon castimatic casting machine (group II). The specimen casting used a graphite mold by a castimatic casting machine (group III). The characteristics of the Ni-Cr alloys, yield and ultimate tensile strength, bending modulus, microhardness, diffraction phase, grindability, ability to spring back, as well as ground microstructure and pattern under different casting conditions were evaluated. The group III specimens exhibited the highest values in terms of strength, modulus, hardness, and grindability at a grind rate of 500 rpm. Moreover, group III alloys exhibited smaller grain sizes, higher ability to spring back, and greater ductility than those casted by sand investment (groups I and II). The main factor, "casting mold," significantly influenced all mechanical properties. The graphite mold casting of the Ni-Cr dental alloys in a controlled atmosphere argon casting system provided an excellent combination of high mechanical properties and good ability to spring back, and preserved the ductile properties for application in Ni-Cr porcelain-fused system. The results can offer recommendations to assist a prosthetic technician in selecting the appropriate casting techniques to obtain the desired alloy properties. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Transferencia de calor en la colada continua de aceros. I parte. El molde

    Directory of Open Access Journals (Sweden)

    Cicutti, C.

    1997-10-01

    Full Text Available The continuous casting mold plays the important role of receiving the liquid steel and allowing an uniform and defect free solidified skin to be developed. In this work, the different heat transfer mechanisms which are present from the liquid steel to the mold cooling water are reviewed. The effect of operating variables on heat extraction and the relationship between global and distributed heat flux are also analyzed.

    El molde de colada continua cumple la importante función de recibir el acero líquido y permitir que se desarrolle una capa solidificada uniforme y libre de defectos. En este trabajo se revisan los distintos mecanismos implicados en el proceso de transferencia de calor, desde el acero líquido hasta el agua de refrigeración del molde. Se analiza también el efecto de las distintas variables de funcionamiento en la extracción calórica producida y la relación entre el flujo global de calor y su distribución a lo largo del molde.

  20. Optimization of injection molding process parameters for a plastic cell phone housing component

    Science.gov (United States)

    Rajalingam, Sokkalingam; Vasant, Pandian; Khe, Cheng Seong; Merican, Zulkifli; Oo, Zeya

    2016-11-01

    To produce thin-walled plastic items, injection molding process is one of the most widely used application tools. However, to set optimal process parameters is difficult as it may cause to produce faulty items on injected mold like shrinkage. This study aims at to determine such an optimum injection molding process parameters which can reduce the fault of shrinkage on a plastic cell phone cover items. Currently used setting of machines process produced shrinkage and mis-specified length and with dimensions below the limit. Thus, for identification of optimum process parameters, maintaining closer targeted length and width setting magnitudes with minimal variations, more experiments are needed. The mold temperature, injection pressure and screw rotation speed are used as process parameters in this research. For optimal molding process parameters the Response Surface Methods (RSM) is applied. The major contributing factors influencing the responses were identified from analysis of variance (ANOVA) technique. Through verification runs it was found that the shrinkage defect can be minimized with the optimal setting found by RSM.

  1. Au-pattern fabrication on a cellulose film using a polyurethane acrylate mold

    International Nuclear Information System (INIS)

    Han, Kwangjoon; Kang, Kwang-Sun; Kim, Jaehwan

    2009-01-01

    This paper deals with a gold micro-patterning process on a cellulose film using a polyurethane acrylate (PUA) mold. Recently, cellulose electro-active paper (EAPap) has been found to be a smart material that can be used for biodegradable sensors, actuators and MEMS devices. However, the hydrophilic and flexible characteristics of cellulose EAPap are major drawbacks for applying a conventional lithography process to fabricate MEMS devices. To overcome these drawbacks, an unconventional lithography process, the so-called micro-transfer printing technique based on a PUA mold, was employed. A master pattern for the PUA mold was fabricated using the conventional photolithography process with an SU-8 photoresist, and the replica of the master pattern was fabricated using PUA. Gold was deposited onto the PUA mold, and a mercaptopropyltrimethoxysilane (MPTMS) self-assembly monolayer was made on the gold surface to securely transfer the gold layer onto the cellulose film. The effect of MPTMS was investigated. Further investigation of the factors to optimize the repeated stamping process will lead to a practical, reusable mold

  2. Development and Characterization of a Metal Injection Molding Bio Sourced Inconel 718 Feedstock Based on Polyhydroxyalkanoates

    Directory of Open Access Journals (Sweden)

    Alexandre Royer

    2016-04-01

    Full Text Available The binder plays the most important role in the metal injection molding (MIM process. It provides fluidity of the feedstock mixture and adhesion of the powder to keep the molded shape during injection molding. The binder must provide strength and cohesion for the molded part and must be easy to remove from the molded part. Moreover, it must be recyclable, environmentally friendly and economical. Also, the miscibility between polymers affects the homogeneity of the injected parts. The goal of this study is to develop a feedstock of superalloy Inconel 718 that is environmentally friendly. For these different binders, formulations based on polyethylene glycol (PEG, because of his water solubility property, and bio sourced polymers were studied. Polyhydroxyalkanoates (PHA were investigated as a bio sourced polymer due to its miscibility with the PEG. The result is compared to a standard formulation using polypropylene (PP. The chemical and rheological behavior of the binder formulation during mixing, injection and debinding process were investigated. The feedstock was characterized in the same way as the binders and the interactions between the powder and the binders were also studied. The results show the well adapted formulation of polymer binder to produce a superalloy Inconel 718 feedstock.

  3. Warpage of QFN Package in Post Mold Cure Process of integrated circuit packaging

    Science.gov (United States)

    Sriwithoon, Nattha; Ugsornrat, Kessararat; Srisuwitthanon, Warayoot; Thonglor, Panakamon

    2017-09-01

    This research studied about warpage of QFN package in post mold cure process of integrated circuit (IC) packages using pre-plated (PPF) leadframe. For IC package, epoxy molding compound (EMC) are molded by cross linking of compound stiffness but incomplete crosslinked network and leading the fully cured thermoset by post mold cure (PMC) process. The cure temperature of PMC can change microstructure of EMC in term of stress inside the package and effect to warpage of the package due to coefficient of thermal expansion (CTE) between EMC and leadframe. In experiment, cure temperatures were varied to check the effect of internal stress due to different cure temperature after completed post mold cure for TDFN 2×3 8L. The cure temperature were varied with 180 °C, 170 °C, 160 °C, and 150°C with cure time 4 and 6 hours, respectively. For analysis, the TDFN 2×3 8L packages were analyzed the warpage by thickness gauge and scanning acoustic microscope (SAM) after take the test samples out from the oven cure. The results confirmed that effect of different CTE between EMC and leadframe due to different cure temperature resulting to warpage of the TDFN 2×3 8L packages.

  4. Micro Machining of Injection Mold Inserts for Fluidic Channel of Polymeric Biochips

    Directory of Open Access Journals (Sweden)

    Myeong-Woo Cho

    2007-08-01

    Full Text Available Recently, the polymeric micro-fluidic biochip, often called LOC (lab-on-a-chip, has been focused as a cheap, rapid and simplified method to replace the existing biochemical laboratory works. It becomes possible to form miniaturized lab functionalities on a chip with the development of MEMS technologies. The micro-fluidic chips contain many micro-channels for the flow of sample and reagents, mixing, and detection tasks. Typical substrate materials for the chip are glass and polymers. Typical techniques for micro-fluidic chip fabrication are utilizing various micro pattern forming methods, such as wet-etching, micro-contact printing, and hot-embossing, micro injection molding, LIGA, and micro powder blasting processes, etc. In this study, to establish the basis of the micro pattern fabrication and mass production of polymeric micro-fluidic chips using injection molding process, micro machining method was applied to form micro-channels on the LOC molds. In the research, a series of machining experiments using micro end-mills were performed to determine optimum machining conditions to improve surface roughness and shape accuracy of designed simplified micro-channels. Obtained conditions were used to machine required mold inserts for micro-channels using micro end-mills. Test injection processes using machined molds and COC polymer were performed, and then the results were investigated.

  5. 3D printed metal molds for hot embossing plastic microfluidic devices.

    Science.gov (United States)

    Lin, Tung-Yi; Do, Truong; Kwon, Patrick; Lillehoj, Peter B

    2017-01-17

    Plastics are one of the most commonly used materials for fabricating microfluidic devices. While various methods exist for fabricating plastic microdevices, hot embossing offers several unique advantages including high throughput, excellent compatibility with most thermoplastics and low start-up costs. However, hot embossing requires metal or silicon molds that are fabricated using CNC milling or microfabrication techniques which are time consuming, expensive and required skilled technicians. Here, we demonstrate for the first time the fabrication of plastic microchannels using 3D printed metal molds. Through optimization of the powder composition and processing parameters, we were able to generate stainless steel molds with superior material properties (density and surface finish) than previously reported 3D printed metal parts. Molds were used to fabricate poly(methyl methacrylate) (PMMA) replicas which exhibited good feature integrity and replication quality. Microchannels fabricated using these replicas exhibited leak-free operation and comparable flow performance as those fabricated from CNC milled molds. The speed and simplicity of this approach can greatly facilitate the development (i.e. prototyping) and manufacture of plastic microfluidic devices for research and commercial applications.

  6. Welding lines formation in holes obtained by low pressure injection molding of ceramic parts

    Directory of Open Access Journals (Sweden)

    C. A. Costa

    Full Text Available Abstract This work presents a study to evaluate the process of producing internal holes in ceramic disks produced by low pressure injection molding (LPIM process. Two process conditions defined as pre-injection and post-injection were used to test the proposition. In the first one the pin cores that produce the holes were positioned in the cavity before the injection of the feedstock; and in the second one, the pin cores were positioned in the cavity, just after the feeding phase of the injection mold. An experimental injection mold designed and manufactured to test both processes was developed to produce ceramic disk with Ø 50 x 2 mm with four holes of Ø 5 mm, equally and radially distributed through the disk. The feedstock was composed of 86 wt% alumina (Al2O3 and 14 wt% organic vehicle based on paraffin wax. Heating and cooling systems controlled by a data acquisition system were included in the mold. The results showed that there were no welding lines with the post-injection process, proving to be an option for creating holes in the ceramic parts produced by LPIM. It was observed that best results were obtained at 58 °C mold temperature. The pins extraction temperature was about 45 °C, and the injection pressure was 170 kPa.

  7. Rapid prototyping of biodegradable microneedle arrays by integrating CO2 laser processing and polymer molding

    International Nuclear Information System (INIS)

    Tu, K T; Chung, C K

    2016-01-01

    An integrated technology of CO 2 laser processing and polymer molding has been demonstrated for the rapid prototyping of biodegradable poly-lactic-co-glycolic acid (PLGA) microneedle arrays. Rapid and low-cost CO 2 laser processing was used for the fabrication of a high-aspect-ratio microneedle master mold instead of conventional time-consuming and expensive photolithography and etching processes. It is crucial to use flexible polydimethylsiloxane (PDMS) to detach PLGA. However, the direct CO 2 laser-ablated PDMS could generate poor surfaces with bulges, scorches, re-solidification and shrinkage. Here, we have combined the polymethyl methacrylate (PMMA) ablation and two-step PDMS casting process to form a PDMS female microneedle mold to eliminate the problem of direct ablation. A self-assembled monolayer polyethylene glycol was coated to prevent stiction between the two PDMS layers during the peeling-off step in the PDMS-to-PDMS replication. Then the PLGA microneedle array was successfully released by bending the second-cast PDMS mold with flexibility and hydrophobic property. The depth of the polymer microneedles can range from hundreds of micrometers to millimeters. It is linked to the PMMA pattern profile and can be adjusted by CO 2 laser power and scanning speed. The proposed integration process is maskless, simple and low-cost for rapid prototyping with a reusable mold. (paper)

  8. Rapid fabrication method of a microneedle mold with controllable needle height and width.

    Science.gov (United States)

    Lin, Yen-Heng; Lee, I-Chi; Hsu, Wei-Chieh; Hsu, Ching-Hong; Chang, Kai-Ping; Gao, Shao-Syuan

    2016-10-01

    The main issue of transdermal drug delivery is that macromolecular drugs cannot diffuse through the stratum corneum of skin. Many studies have pursued micro-sized needles encapsulated with drugs to overcome this problem, as these needles can pierce the stratum corneum and allow drugs to enter the circulatory system of the human body. However, most microneedle fabrication processes are time-consuming and require expensive equipment. In this study, we demonstrate a rapid method for fabricating a microneedle mold using drawing lithography and a UV-cured resin. The mold was filled with a water-soluble material, polyvinylpyrrolidone (PVP), which was then demolded to produce a water-soluble microneedle array. The results of an in vitro skin insertion test using PVP microneedles and pig ear skin demonstrated the feasibility of the microneedle mold. In addition, by controlling the viscosity of the UV-cured resin through various heat treatments, microneedles with different heights and aspect ratios were produced. Compared with other methods, this technology significantly simplifies and accelerates the mold fabrication process. In addition, the required equipment is relatively simple and inexpensive. Through this technology, we can rapidly fabricate microneedle molds with controllable dimensions for various applications.

  9. Rapid prototyping of biodegradable microneedle arrays by integrating CO2 laser processing and polymer molding

    Science.gov (United States)

    Tu, K. T.; Chung, C. K.

    2016-06-01

    An integrated technology of CO2 laser processing and polymer molding has been demonstrated for the rapid prototyping of biodegradable poly-lactic-co-glycolic acid (PLGA) microneedle arrays. Rapid and low-cost CO2 laser processing was used for the fabrication of a high-aspect-ratio microneedle master mold instead of conventional time-consuming and expensive photolithography and etching processes. It is crucial to use flexible polydimethylsiloxane (PDMS) to detach PLGA. However, the direct CO2 laser-ablated PDMS could generate poor surfaces with bulges, scorches, re-solidification and shrinkage. Here, we have combined the polymethyl methacrylate (PMMA) ablation and two-step PDMS casting process to form a PDMS female microneedle mold to eliminate the problem of direct ablation. A self-assembled monolayer polyethylene glycol was coated to prevent stiction between the two PDMS layers during the peeling-off step in the PDMS-to-PDMS replication. Then the PLGA microneedle array was successfully released by bending the second-cast PDMS mold with flexibility and hydrophobic property. The depth of the polymer microneedles can range from hundreds of micrometers to millimeters. It is linked to the PMMA pattern profile and can be adjusted by CO2 laser power and scanning speed. The proposed integration process is maskless, simple and low-cost for rapid prototyping with a reusable mold.

  10. Redesign and Automation of a mold for manufacturing of refrigerated display cases using Polyurethane Foam Injection

    Directory of Open Access Journals (Sweden)

    Eugenio Yime

    2016-10-01

    Full Text Available Context: To stay competitive over time, a company must continually submit their processes to improvements and updates. Herein are proposed some improvements with regard to safety at work and the reduction of time that occurs during the operation of a mold for manufacturing refrigerators. Method: Some operating conditions of the mold are analyzed and then some factors affecting the processing time and the safety of operating personnel are established. The weaknesses found are related to the intrinsic design of the mold, which raises the need for a structural redesign that also includes automation. Results: It is presented a new design and way to operate the mold which reduces the risk of accidents at having no heavy loads over operator heads. Another contribution of the redesign is the increase in the system rigidity which helps to reduce manufacturing defects. Finally, it is show a automation design which helps to reduce manufacturing times. Conclusions: Significant improvements were obtained in the operation of the mold, such as the reduction of occupational hazards and reduced manufacturing time of refrigerators. These improvements translate into benefits for the company, by reducing costs and increasing production. Both benefits help strengthen the competitiveness of the company.

  11. Deep UV patterning of acrylic masters for molding biomimetic dry adhesives

    International Nuclear Information System (INIS)

    Sameoto, D; Menon, C

    2010-01-01

    We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance

  12. Application of atmospheric-pressure argon plasma jet for bread mold decontamination

    Science.gov (United States)

    Thonglor, P.; Amnuaycheewa, P.

    2017-09-01

    Atmospheric-pressure argon plasma (APAP) is a promising non-thermal technology for microbial control and prevention minimally affecting quality of foods. Effect of APAP jet on the growth of bread molds, including two Aspergillus sp., Rhizopus stolonifer, and Penicillium roqueforti, isolated from white bread were investigated. The molds were isolated, verified, cultured to fully grown on potato dextrose agar (PDA), and subsequently treated with APAP jet using plasma generating power at 24 W for 5, 10, and 20 min, respectively. The inhibition of mold growth was investigated by comparing fungal dry weights and the effect on fungal cell structure was observed using compound light microscope. The results indicated that the 20-min treatment time is most effective in retarding the growth of the three bread molds. However, this level of generating power did not lead to destruction of the cellular structures for all the four fungi. Plasma generating power and treatment time are significant parameters determining the success of bread mold decontamination and further investigation on real bread matrix is needed.

  13. Parameter Optimization Of Natural Hydroxyapatite/SS316l Via Metal Injection Molding (MIM)

    Science.gov (United States)

    Mustafa, N.; Ibrahim1, M. H. I.; Amin, A. M.; Asmawi, R.

    2017-01-01

    Metal injection molding (MIM) are well known as a worldwide application of powder injection molding (PIM) where as applied the shaping concept and the beneficial of plastic injection molding but develops the applications to various high performance metals and alloys, plus metal matrix composites and ceramics. This study investigates the strength of green part by using stainless steel 316L/ Natural hydroxyapatite composite as a feedstock. Stainless steel 316L (SS316L) was mixed with Natural hydroxyapatite (NHAP) by adding 40 wt. % Low Density Polyethylene and 60 %wt. Palm Stearin as a binder system at 63 wt. % powder loading consist of 90 % wt. of SS316 L and 10 wt. % NHAP prepared thru critical powder volume percentage (CPVC). Taguchi method was functional as a tool in determining the optimum green strength for Metal Injection Molding (MIM) parameters. The green strength was optimized with 4 significant injection parameter such as Injection temperature (A), Mold temperature (B), Pressure (C) and Speed (D) were selected throughout screening process. An orthogonal array of L9 (3)4 was conducted. The optimum injection parameters for highest green strength were established at A1, B2, C0 and D1 and where as calculated based on Signal to Noise Ratio.

  14. Real-time parameter optimization based on neural network for smart injection molding

    Science.gov (United States)

    Lee, H.; Liau, Y.; Ryu, K.

    2018-03-01

    The manufacturing industry has been facing several challenges, including sustainability, performance and quality of production. Manufacturers attempt to enhance the competitiveness of companies by implementing CPS (Cyber-Physical Systems) through the convergence of IoT(Internet of Things) and ICT(Information & Communication Technology) in the manufacturing process level. Injection molding process has a short cycle time and high productivity. This features have been making it suitable for mass production. In addition, this process is used to produce precise parts in various industry fields such as automobiles, optics and medical devices. Injection molding process has a mixture of discrete and continuous variables. In order to optimized the quality, variables that is generated in the injection molding process must be considered. Furthermore, Optimal parameter setting is time-consuming work to predict the optimum quality of the product. Since the process parameter cannot be easily corrected during the process execution. In this research, we propose a neural network based real-time process parameter optimization methodology that sets optimal process parameters by using mold data, molding machine data, and response data. This paper is expected to have academic contribution as a novel study of parameter optimization during production compare with pre - production parameter optimization in typical studies.

  15. Contamination of cattle feed with molds and mycotoxins

    Directory of Open Access Journals (Sweden)

    Krnjaja Vesna

    2013-01-01

    Full Text Available The total number of potentially toxigenic molds (fungi, total aflatoxins, zearalenone (ZON, and deoxynivalenol (DON, as well as the joint appearance of ZON and DON have been investigated in 67 samples of cattle feed (concentrate (n=21, silage of whole maize plant (n=18, beet pulp (n=4, brewer's malt (n=2, alfalfa and grass (n=1, alfalfa hay (n=12, meadow hay (n=7, pea and oat hay (n=1, and red clover hay (n=1 originating from private farms from 10 districts of the Republic of Serbia. The total number of fungi per 1 g feed ranged from 0 (silage of brewer’s malt to 12 x 104 (concentrate. Eight fungi genus species have been identified: Acremonium, Alternaria, Aspergillus, Fusarium, Mucor, Penicillum, Rhizopus and Trichoderma. The presence of ZON (100% was established in all the examined cattle feed samples, while 98.5% samples were contaminated with total aflatoxins and 92.5% samples were DON positive. The joint appearance of ZON and DON was established in 92.5% samples. ZON was present in the highest average concentration in the sample of alfalfa and grass silage (2477.5 μg kg-1 and in the lowest in beet pulp silage samples (64.9 μg kg-1. Total aflatoxins were established in the highest average concentration in the pea and oat hay silage sample (7.9 μg kg-1 and in the lowest average concentration in beet pulp silage samples (1.6 μg kg-1. DON was detected in the highest average concentration in concentrate samples (694.2 μg kg-1 and in the lowest average concentration in the red clover hay sample (11.0 μg kg-1, while DON was not detected in brewer's malt silage samples (0.0 μg kg-1. In all the examined cattle feed samples, between moisture content (up to 20% and the concentration of examined mycotoxins, a negative correlation was established (r=-0.26 with total aflatoxins and a positive correlation with ZON (r=0,36 and DON (r=0,60. Furthermore, a positive correlation (r=0.22 was established between ZON and DON concentrations. [Projekat

  16. Sensitization rates of airborne pollen and mold in children

    Directory of Open Access Journals (Sweden)

    So Hyun Park

    2012-09-01

    Full Text Available &lt;B&gt;Purpose:&lt;/b&gt; Aeroallergens are important causative factors of allergic diseases. Previous studies on aeroallergen sensitization rates investigated patients groups that had visited pediatric allergy clinics. In contrast, we investigated sensitization rates in a general population group of elementary school to teenage students in Incheon, Jeju, and Ulsan. &lt;b&gt;Methods:&lt;/B&gt; After obtaining parental consent, skin-prick tests were performed on 5,094 students between March and June 2010. Elementary school students were tested for 18 common aeroallergens, whereas middle and high school students were tested for 25 allergens. The 25 allergens included &lt;I&gt;Dermatophagoides pteronyssinus, Dermatophagoides farinae&lt;/I&gt;, pollen (birch, alder, oak, Japanese cedar, pine, willow, elm, maple, Bermuda grass, timothy grass, rye grass, orchard grass, meadow grass, vernal grass, mugwort, Japanese hop, fat hen, ragweed, and plantain, and mold (&lt;I&gt;Penicillatum, Aspergillus, Cladosporium, and Alternaria&lt;/I&gt;. &lt;b&gt;Results:&lt;/b&gt; The sensitization rates in descending order were 25.79% (&lt;I&gt;D. pteronyssinus&lt;/I&gt; , 18.66% (&lt;I&gt;D. farinae&lt;/I&gt; , 6.20% (mugwort, and 4.07% (willow in Incheon; 33.35% (&lt;I&gt;D. pteronyssinus&lt;/I&gt; , 24.78% (&lt;I&gt;D. farinae&lt;/I&gt;, 15.36% (Japanese cedar, and 7.33% (Alternaria in Jeju; and 32.79% (D. pteronyssinus, 30.27% (D. farinae, 10.13% (alder, and 8.68% (birch in Ulsan. The dust mite allergen showed the highest sensitization rate among the 3 regions. The sensitization rate of tree pollen was the highest in Ulsan, whereas that of Alternaria was the highest in Jeju. The ragweed sensitization rates were 0.99% in Incheon, 1.07% in Jeju, and 0.81% in Ulsan. &lt;b&gt;Conclusion:&lt;/b&gt; The

  17. Evaluation by nanoindentation of technological products manufactured by pulse injection molding process

    Directory of Open Access Journals (Sweden)

    Natova Margarita

    2018-01-01

    Full Text Available During conventional polymer injection molding, flow- and weld lines can arise at the molded parts caused by disturbed polymer melt flow when it crosses different parts of the equipment. Such processed plastic goods have discrete zones of inhomogeneities of very small dimensions. In order to stabilize the melt flow and to equalize dimensions of such defective products, an approach for pulse injection molding is applied during production of polymer packagings. Testing methods used for evaluation of macromechanical performance of processed polymer products are not readily applicable to estimate the changes in visual surface obtained during pulse injecting. To overcome this testing inconvenience the performance of processed packagings is evaluated by nanoindentation. Using this method, a quantitative assessment of the polymer properties is obtained from different parts of technological products.

  18. Experimental Investigation into Suitable Process Conditions for Plastic Injection Molding of Thin-Sheet Parts

    Directory of Open Access Journals (Sweden)

    Dyi-Cheng Chen

    2014-04-01

    Full Text Available This study performs an experimental investigation into the effects of the process parameters on the surface quality of injection molded thin-sheet thermoplastic components. The investigations focus specifically on the shape, number and position of the mold gates, the injection pressure and the injection rate. It can be seen that the gravity force entering point improved filling of the cavity for the same forming time and injection pressure. Moreover, it shows the same injection pressure and packing time, the taper-shape gate yields a better surface appearance than the sheet-shape gate. The experimental results provide a useful source of reference in suitable the process conditions for the injection molding of thin-sheet plastic components.

  19. Biological control of white mold by Trichoderma harzianum in common bean under field conditions

    Directory of Open Access Journals (Sweden)

    Daniel Diego Costa Carvalho

    2015-12-01

    Full Text Available Abstract: The objective of this work was to evaluate Trichoderma harzianum isolates for biological control of white mold in common bean (Phaseolus vulgaris. Five isolates were evaluated for biocontrol of white mold in 'Perola' common bean under field conditions, in the 2009 and 2010 crop seasons. A commercial isolate (1306 and a control treatment were included. Foliar applications at 2x109 conidia mL-1 were performed at 42 and 52 days after sowing (DAS, in 2009, and at 52 DAS in 2010. The CEN287, CEN316, and 1306 isolates decreased the number of Sclerotinia sclerotiorum apothecia per square meter in comparison to the control, in both crop seasons. CEN287, CEN316, and 1306 decreased white mold severity during the experimental period, when compared to the control.

  20. Investigation of CFRP in aerospace field and improvement of the molding accuracy by using autoclave

    Science.gov (United States)

    Minamisawa, Takunori

    2017-07-01

    In recent years, CFRP (Carbon Fiber Reinforced Plastic) has come to be used in a wide range of industries such as sporting goods, fishing tackle and cars because it has a large number of advantages. In this situation, even the passenger aircraft industry also pays attention to the material. CFRP is an ideal material for airplanes because it has a lot of advantages such as light weight and strong, chemical resistance and corrosion resistance. Generally, autoclave is used for molding CFRP in the field of aerospace engineering. Autoclave is a machine that can mold a product by heating and pressurizing material in an evacuated bag. What is examined in this paper is an observation on handmade CFRP by a polarizing microscope. In addition, mechanical characteristics were investigated. Furthermore, an improvement of accuracy in CFRP molding using an autoclave is suggested from viewpoint of thermodynamics.