Sample records for agarose mold compliance

  1. Mold Testing or Sampling (United States)

    In most cases, if visible mold growth is present, sampling is unnecessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building's compliance with federal mold standards.

  2. Mold

    Centers for Disease Control (CDC) Podcasts


    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.

  3. Mold Allergy (United States)

    ... Ask the Allergist Health Professionals Partners Media Donate Allergies Mold Allergy What Is a Mold Allergy? If you have an allergy that occurs over ... basement. What Are the Symptoms of a Mold Allergy? The symptoms of mold allergy are very similar ...

  4. Preparation of Agarose Sulfate and Its Antithrombogenicity

    Institute of Scientific and Technical Information of China (English)

    JIE Youping; ZHANG Lingmin; CHEN Peng; MAO Xuan; TANG Shunqing


    As one of the seaweed polysaccharide,agarose has received much attention because of its biocompatibility.However,its application in biomedical field was limited with its biological inertia.Modification with some functional groups is needed to obtain agarose derivatives with biological activity and expand its applications.Consequently,agarose was sulfated with chlorosulfonic acid-pyridine with formamide as dispersing agent.The orthogonal test result showed that the optimal reaction condition was the reaction time being 4 h,the reaction temperature 65 ℃,and the ratio of chlorosulfonic acid to agarose 1-4(mL/g).Two kinds of the insoluble agarose sulfate (below 37 ℃) were synthesized with degree of substitution (DS) being 0.17 and 0.43 respectively.Infrared spectroscopy (IR) and 13C nuclear magnetic resonance (13C-NMR) spectroscopy results proved that C3-6 in agarose was sulfated.Their hydrophobic property and BSA adsorption capacity rose with increasing DS,while the adsorption of Hb was reduced.The anti-clotting properties of agarose sulfate were significantly improved,and agarose sulfate could protect red blood cells from deformation after adsorption of BSA.These findings demonstrate that the cold-water insoluble agarose sulfate has a promise for applications as heparin-like material in anticoagulation or endothelial regeneration scaffold.

  5. Allergies, asthma, and molds (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 ...

  6. Molds in the Environment (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, ...

  7. Non-toxic agarose/gelatin-based microencapsulation system containing gallic acid for antifungal application. (United States)

    Lam, P-L; Gambari, R; Kok, S H-L; Lam, K-H; Tang, J C-O; Bian, Z-X; Lee, K K-H; Chui, C-H


    Aspergillus niger (A. niger) is a common species of Aspergillus molds. Cutaneous aspergillosis usually occurs in skin sites near intravenous injection and approximately 6% of cutaneous aspergillosis cases which do not involve burn or HIV-infected patients are caused by A. niger. Biomaterials and biopharmaceuticals produced from microparticle-based drug delivery systems have received much attention as microencapsulated drugs offer an improvement in therapeutic efficacy due to better human absorption. The frequently used crosslinker, glutaraldehyde, in gelatin-based microencapsulation systems is considered harmful to human beings. In order to tackle the potential risks, agarose has become an alternative polymer to be used with gelatin as wall matrix materials of microcapsules. In the present study, we report the eco-friendly use of an agarose/gelatin-based microencapsulation system to enhance the antifungal activity of gallic acid and reduce its potential cytotoxic effects towards human skin keratinocytes. We used optimal parameter combinations, such as an agarose/gelatin ratio of 1:1, a polymer/oil ratio of 1:60, a surfactant volume of 1% w/w and a stirring speed of 900 rpm. The minimum inhibitory concentration of microencapsulated gallic acid (62.5 µg/ml) was significantly improved when compared with that of the original drug (>750 µg/ml). The anti-A. niger activity of gallic acid -containing microcapsules was much stronger than that of the original drug. Following 48 h of treatment, skin cell survival was approximately 90% with agarose/gelatin microcapsules containing gallic acid, whereas cell viability was only 25-35% with free gallic acid. Our results demonstrate that agarose/gelatin-based microcapsules containing gallic acid may prove to be helpful in the treatment of A. niger-induced skin infections near intravenous injection sites.

  8. Dynamic pressure transmission through agarose gels

    NARCIS (Netherlands)

    Berglund, LJ; An, KN; O'Driscoll, SW


    In biomedical research, agarose gel is widely used in tissue culture systems because it permits growing cells and tissues in a three-dimensional suspension. This is especially important in the application of tissue engineering concepts to cartilage repair because it supports the cartilage phenotype.

  9. Compliance Framing - Framing Compliance


    Lutz-Ulrich Haack; Martin C. Reimann


    Corporations have to install various organizational measures to comply with legal as well as internal guidelines systematically. Compliance management systems have the challenging task to make use of an internal compliance-marketing approach in order to ensure not only an adequate but also effective compliance-culture. Compliance-literature and findings of persuasive goal-framing-theory give opposite implications for establishing a rather values- versus rule-based compliance-culture respectiv...

  10. Crosslinking of agarose bioplastic using citric acid. (United States)

    Awadhiya, Ankur; Kumar, David; Verma, Vivek


    We report chemical crosslinking of agarose bioplastic using citric acid. Crosslinking was confirmed using Fourier transform infrared (FTIR) spectroscopy. The effects of crosslinking on the tensile strength, swelling, thermal stability, and degradability of the bioplastic were studied in detail. The tensile strength of the bioplastic films increased from 25.1MPa for control films up to a maximum of 52.7MPa for citric acid crosslinked films. At 37°C, the amount of water absorbed by crosslinked agarose bioplastic was only 11.5% of the amount absorbed by non-crosslinked controls. Thermogravimetric results showed that the crosslinked samples retain greater mass at high temperature (>450°C) than control samples. Moreover, while the crosslinked films were completely degradable, the rate of degradation was lower compared to non-crosslinked controls.

  11. Bleach Neutralizes Mold Allergens (United States)

    Science Teacher, 2005


    Researchers at National Jewish Medical and Research Center have demonstrated that dilute bleach not only kills common household mold, but may also neutralize the mold allergens that cause most mold-related health complaints. The study, published in the Journal of Allergy and Clinical Immunology, is the first to test the effect on allergic…

  12. Composition of agarose substrate affects behavioral output of Drosophila larvae

    Directory of Open Access Journals (Sweden)

    Anthi Aristomenis Apostolopoulou


    Full Text Available In the last decade the Drosophila larva has evolved into a simple model organism offering the opportunity to integrate molecular genetics with systems neuroscience. This led to a detailed understanding of the functional neuronal networks for a number of sensory functions and behaviors including olfaction, vision, gustation and learning and memory. Typically, behavioral assays in use exploit simple Petri dish setups with either agarose or agar as a substrate. However, neither the quality nor the concentration of the substrate is generally standardized across these experiments and there is no data available on how larval behavior is affected by such different substrates. Here, we have investigated the effects of different agarose concentrations on several larval behaviors. We demonstrate that agarose concentration is an important parameter, which affects all behaviors tested: preference, feeding, learning and locomotion. Larvae can discriminate between different agarose concentrations, they feed differently on them, they can learn to associate an agarose concentration with an odor stimulus and crawl faster on a substrate of higher agarose concentration. Additionally, we have investigated the effect of agarose concentration on three quinine based behaviors: preference, feeding and learning. We show that in all cases examined the behavioral output changes in an agarose concentration-dependent manner. Our results suggest that comparisons between experiments performed on substrates differing in agarose concentration should be done with caution. It should be taken into consideration that the agarose concentration can affect the behavioral output and thereby the experimental outcomes per se potentially due to an increased escape response on more rigid substrates.

  13. Agarose encapsulated mesoporous carbonated hydroxyapatite nanocomposites powder for drug delivery. (United States)

    Kolanthai, Elayaraja; Abinaya Sindu, P; Thanigai Arul, K; Sarath Chandra, V; Manikandan, E; Narayana Kalkura, S


    The powder composites are predominantly used for filling of voids in bone and as drug delivery carrier to prevent the infection or inflammatory reaction in the damaged tissues. The objective of this work was to study the synthesis of agarose encapsulation on carbonated hydroxyapatite powder and their biological and drug delivery properties. Mesoporous, nanosized carbonated hydroxyapatite/agarose (CHAp/agarose) powder composites were prepared by solvothermal method and subsequently calcined to study the physico-chemical changes, if it subjected to thermal exposure. The phase of the as-synthesized powder was CHAp/agarose whereas the calcinated samples were non-stoichiometric HAp. The CHAp/agarose nanorods were of length 10-80nm and width 40-190nm for the samples synthesized at temperatures 120°C (ST120) and 150°C (ST150). The calcination process produced spheres (10-50nm) and rods with reduced size (40-120nm length and 20-30nm width). Composites were partially dissolved in SBF solution followed by exhibited better bioactivity than non-stoichiometric HAp confirmed by gravimetric method. Hemo and biocompatibility remained unaffected by presence of agarose or carbonate in the HAp. Specific surface area of the composites was high and exhibited an enhanced amoxicillin and 5-fluorouracil release than the calcined samples. The composites demonstrated a strong antimicrobial activity against E. coli, S. aureus and S. epidermidis. The ST120 showed prolonged drug (AMX and 5-Fcil) release and antimicrobial efficacy than ST150 and calcined samples. This technique would be simple and rapid for composites preparation, to produce high quality crystalline, resorbable, mesoporous and bioactive nanocomposite (CHAp/agarose) powders. This work provides new insight into the role of agarose coated on bioceramics by solvothermal technique and suggests that CHAp/agarose composites powders are promising materials for filling of void in bone and drug delivery applications.

  14. Phenolic Molding Compounds (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.

  15. Mold design with simulation for chalcogenide glass precision molding (United States)

    Zhang, Yunlong; Wang, Zhibin; Li, Junqi; Zhang, Feng; Su, Ying; Wang, Zhongqiang


    Compare with the manufacturing of the traditional infrared material, such as signal crystal germanium, zinc sulfide, zinc selenide etc, chalcogenide infrared glass is suitable for precision molding for the low soften temperature to have large mass industry production. So the researches of precision glass molding are necessary, especially for the fast development of infrared product. The mold design is one of the key technologies of precision glass molding. In this paper, the mold processing of a sample chalcogenide glass from the technical drawing, mold design, molding to the lens are introduced. From the result of the precision molding, the technology of finite element simulation is a useful way to guiding the mold design. The molded lens by using mold process fit the design requirement.

  16. Silicon micro-mold (United States)

    Morales, Alfredo M.


    The present invention describes a method for rapidly fabricating a robust 3-dimensional silicon-mold for use in preparing complex metal micro-components. The process begins by depositing a conductive metal layer onto one surface of a silicon wafer. A thin photoresist and a standard lithographic mask are then used to transfer a trace image pattern onto the opposite surface of the wafer by exposing and developing the resist. The exposed portion of the silicon substrate is anisotropically etched through the wafer thickness down to conductive metal layer to provide an etched pattern consisting of a series of rectilinear channels and recesses in the silicon which serve as the silicon micro-mold. Microcomponents are prepared with this mold by first filling the mold channels and recesses with a metal deposit, typically by electroplating, and then removing the silicon micro-mold by chemical etching.

  17. Glass molding process with mold lubrication (United States)

    Davey, Richard G.


    Improvements are provided in glass forming processes of the type wherein hot metal blank molds are employed by using the complementary action of a solid film lubricant layer, of graphite dispersed in a cured thermoset organopolysiloxane, along with an overspray of a lubricating oil.

  18. Mold Image Library (United States)

    Jump to main content US EPA United States Environmental Protection Agency Search Search Mold Share Facebook Twitter Google+ ... the foundation of this house Fix: It is important that the water drain away from the foundation— ...

  19. [Methodical features of the molding of diagnostic competences in medical parasitology workers]. (United States)

    Dovgalev, A S; Astanina, S Iu; Avdiukhina, T I; Serdiuk, A P; Imamkuliev, K D


    The paper provides a rationale for a procedure to mold diagnostic competences in medical workers of the laboratories of therapeutic-and-prophylactic institutions and hygiene and epidemiology centers, Russian Federal Service for Supervision of Consumer Rights Protection and Human Welfare. The methodical features of molding diagnostic competences in the above contingents are the design and organization of an educational process by applying systems integration and competence-based approaches; increased active self-directed learning of audience; a procedure to organize its unsupervised extracurricular activities. Professional habits and skills in laboratory specialists should be molded on the basis of didactic principles and in compliance with the found methodical patterns. The eventual result (molded competences) and its compliance with the practical health care requirements is assessed using all control types (incoming, running, intermediate, and ultimate ones). This ensures the stability and predictability of molding diagnostic competences in parasitology specialists.

  20. Transferability of glass lens molding (United States)

    Katsuki, Masahide


    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.

  1. Preparation and Characterization of Chitosan—Agarose Composite Films

    Directory of Open Access Journals (Sweden)

    Zhang Hu


    Full Text Available Nowadays, there is a growing interest to develop biodegradable functional composite materials for food packaging and biomedicine applications from renewable sources. Some composite films were prepared by the casting method using chitosan (CS and agarose (AG in different mass ratios. The composite films were analyzed for physical-chemical-mechanical properties including tensile strength (TS, elongation-at-break (EB, water vapor transmission rate (WVTR, swelling ratio, Fourier-transform infrared spectroscopy, and morphology observations. The antibacterial properties of the composite films were also evaluated. The obtained results reveal that an addition of AG in varied proportions to a CS solution leads to an enhancement of the composite film’s tensile strength, elongation-at-break, and water vapor transmission rate. The composite film with an agarose mass concentration of 60% was of the highest water uptake capacity. These improvements can be explained by the chemical structures of the new composite films, which contain hydrogen bonding interactions between the chitosan and agarose as shown by Fourier-transform infrared spectroscopy (FTIR analysis and the micro-pore structures as observed with optical microscopes and scanning electron microscopy (SEM. The antibacterial results demonstrated that the films with agarose mass concentrations ranging from 0% to 60% possessed antibacterial properties. These results indicate that these composite films, especially the composite film with an agarose mass concentration of 60%, exhibit excellent potential to be used in food packaging and biomedical materials.

  2. Uptake and Recovery of Lead by Agarose Gel Polymers

    Directory of Open Access Journals (Sweden)

    Anurag Pandey


    Full Text Available Problem statement: The uptake and recovery of lead ions were investigated by using agarose gel polymers. Approach: The experimental results showed that the agarose gel were effective in removing Pb (II from solution. Biosorption equilibrium was approached within 4 h. Pseudo second-order was applicable to all the sorption data over the entire time range. Results: The sorption data conformed well to both the Langmuir and the Freundlich isotherm model. The maximum adsorption capacity (qmax onto agarose gel was 115 mg g-1 for Pb (II. The maximum uptake of metal ions was obtained at pH 2.0. At temperature 35°C, the biosorption of metal ions was found to be highest, with increase or decrease in temperature resulted in a decrease in the metal ions uptake capacity. Conclusion: Elution experiments were carried out to remove Pb (II ions from loaded agarose gel and the bound metal ions could be eluted successfully using 0.1 M EDTA solution. The results suggest that agarose gel can be used as a biosorbent for an efficient removal of Pb(II ions from aqueous solution.

  3. Dynamic of taking out molding parts at injection molding

    Directory of Open Access Journals (Sweden)

    E. Ragan


    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.

  4. Meer bekend over Black Mold

    NARCIS (Netherlands)

    Duyvesteijn, R.G.E.; Kohrman, E.


    In de vollegrondsrozenteelt zorgde Black Mold in 2007 voor een groot aantal mislukte oculaties. In 2008 waren er aanzienlijk minder problemen. Uit onderzoek is meer bekend over de oorzaak en bestrijding van Black Mold.

  5. Phase separation micro molding

    NARCIS (Netherlands)

    Vogelaar, Laura


    The research described in this thesis concerns the development of a new microfabrication method, Phase Separation Micro Molding (PSμM). While microfabrication is still best known from semiconductor industry, where it is used to integrate electrical components on a chip, the scope has immensely expan

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

    Energy Technology Data Exchange (ETDEWEB)

    Bernacki, Bruce E.


    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.

  7. Reciclagem de agarose em laboratórios de biologia molecular Recycling agarose in molecular biology laboratories

    Directory of Open Access Journals (Sweden)

    Lia Rejane Silveira Reiniger


    Full Text Available Em laboratórios de biologia molecular, a eletroforese em gel de agarose é usada, rotineiramente, para separar moléculas de ácidos nucléicos. A agarose é um polímero extraído de algas marinhas que apresenta custo elevado. O objetivo do presente trabalho consistiu na otimização de um protocolo de reciclagem deste produto, após proceder a descontaminação de brometo de etídio, possibilitando sua reutilização em eletroforese analítica. O processo, originalmente proposto por PALACIOS et al. (2000, recebeu modificações e consistiu em equilibrar a agarose em água, efetuar sua secagem e transformá-la novamente em pó, em moinho. O produto reciclado assemelhou-se ao original, apresentando grânulos ligeiramente maiores e mais escuros. Os géis foram preparados da mesma maneira que usando o produto original, não requerendo nenhum procedimento adicional. A agarose reciclada ficou disponível para uso imediato, podendo ser armazenada à temperatura ambiente, por longos períodos de tempo e ocupando uma pequena área. Presta-se à elaboração de géis analíticos das mais variadas concentrações e composições de tampão. Além disso, a reciclagem também contribui para a diminuição de resíduos sólidos descartados no meio ambiente e resulta em significativa redução de custos. Os géis com o produto reciclado mostraram desempenho semelhante na eletroforese e possibilitaram uma adequada resolução das bandas.In molecular biology laboratories, the agarose gel electrophoresis is used on a daily basis in order to separate nucleic acid molecules. The agarose is a polimere of elevated cost. The goal of the present work consisted in the optimization of a protocole of agarose recycling, transforming it, once again, into a powdery material similar to the original, after performing the decontamination of Ethidium bromide, allowing its reuse in analitycal electrophoresis. The process, originally proposed by PALACIOS et al. (2000 receveid

  8. Compliance status

    Energy Technology Data Exchange (ETDEWEB)

    Black, D.G.


    This section of the 1994 Hanford Site Environmental Report summarizes the activities conducted to ensure that the Hanford Site is in compliance with federal environmental protection statutes and related Washington State and local environmental protection regulations and the status of Hanford`s compliance with these requirements. Environmental permits required under the environmental protection regulations are discussed under the applicable statute.

  9. Agarose and methylcellulose hydrogel blends for nerve regeneration applications (United States)

    Martin, Benton C.; Minner, Eric J.; Wiseman, Sherri L.; Klank, Rebecca L.; Gilbert, Ryan J.


    Trauma sustained to the central nervous system is a debilitating problem for thousands of people worldwide. Neuronal regeneration within the central nervous system is hindered by several factors, making a multi-faceted approach necessary. Two factors contributing to injury are the irregular geometry of injured sites and the absence of tissue to hold potential nerve guides and drug therapies. Biocompatible hydrogels, injectable at room temperature, that rapidly solidify at physiological temperatures (37 °C) are beneficial materials that could hold nerve guidance channels in place and be loaded with therapeutic agents to aid wound healing. Our studies have shown that thermoreversible methylcellulose can be combined with agarose to create hydrogel blends that accommodate these properties. Three separate novel hydrogel blends were created by mixing methylcellulose with one of the three different agaroses. Gelation time tests show that the blends solidify at a faster rate than base methylcellulose at 37 °C. Rheological data showed that the elastic modulus of the hydrogel blends rapidly increases at 37 °C. Culturing experiments reveal that the morphology of dissociated dorsal root ganglion neurons was not altered when the hydrogels were placed onto the cells. The different blends were further assessed using dissolution tests, pore size evaluations using scanning electron microscopy and measuring the force required for injection. This research demonstrates that blends of agarose and methylcellulose solidify much more quickly than plain methylcellulose, while solidifying at physiological temperatures where agarose cannot. These hydrogel blends, which solidify at physiological temperatures naturally, do not require ultraviolet light or synthetic chemical cross linkers to facilitate solidification. Thus, these hydrogel blends have potential use in delivering therapeutics and holding scaffolding in place within the nervous system.

  10. Preparation and stability of agarose microcapsules containing BCG. (United States)

    Esquisabel, A; Hernandez, R M; Igartua, M; Gascón, A R; Calvo, B; Pedraz, J L


    An emulsification/internal gelation method of preparing small-sized agarose microcapsules containing Bacillus Calmette-Guerin (BCG) is reported. Agarose microcapsules have been prepared by the emulsification of the hydrogel within a vegetable oil followed by its gelation due to the cooling of the system. Four different oils (sesame, sweet almonds, camomile and jojoba) were assayed. The rheological analysis of the oils showed a Newtonian behaviour, with viscosity values of 37.7, 51.2, 59.3 and 67.1 mPa s for jojoba, camomile, sesame and sweet almonds oil, respectively. The particle size of the microcapsules obtained ranged from 23.1 microm for the microcapsules prepared with sweet almonds oil to 42.6 microm for those prepared with jojoba. The microcapsule particle size was found to be dependent on the viscosity of the oil used in the emulsification step. The encapsulated BCG was identified by the Difco TB stain set K, followed by observation under optical microscopy. Once prepared, microcapsules were freeze-dried using 5% trehalose as cryoprotectant and the stability of the microcapsules was assayed during 12 months storage at room temperature, observing that agarose microcapsules were stable after 12 months storage, since there was no evidence of alteration in the freeze-dried appearance, resuspension rate, observation under microscope, or particle size.

  11. Posing for a picture: vesicle immobilization in agarose gel (United States)

    Lira, Rafael B.; Steinkühler, Jan; Knorr, Roland L.; Dimova, Rumiana; Riske, Karin A.


    Taking a photo typically requires the object of interest to stand still. In science, imaging is potentiated by optical and electron microscopy. However, living and soft matter are not still. Thus, biological preparations for microscopy usually include a fixation step. Similarly, immobilization strategies are required for or substantially facilitate imaging of cells or lipid vesicles, and even more so for acquiring high-quality data via fluorescence-based techniques. Here, we describe a simple yet efficient method to immobilize objects such as lipid vesicles with sizes between 0.1 and 100 μm using agarose gel. We show that while large and giant unilamellar vesicles (LUVs and GUVs) can be caged in the pockets of the gel meshwork, small molecules, proteins and micelles remain free to diffuse through the gel and interact with membranes as in agarose-free solutions, and complex biochemical reactions involving several proteins can proceed in the gel. At the same time, immobilization in agarose has no adverse effect on the GUV size and stability. By applying techniques such as FRAP and FCS, we show that the lateral diffusion of lipids is not affected by the gel. Finally, our immobilization strategy allows capturing high-resolution 3D images of GUVs.

  12. Fabrication of multilayered vascular tissues using microfluidic agarose hydrogel platforms. (United States)

    Kinoshita, Keita; Iwase, Masaki; Yamada, Masumi; Yajima, Yuya; Seki, Minoru


    Vascular tissues fabricated in vitro are useful tools for studying blood vessel-related cellular physiologies and for constructing relatively large 3D tissues. An efficient strategy for fabricating vascular tissue models with multilayered, branched, and thick structures through the in situ hydrogel formation in fluidic channels is proposed. First, an aqueous solution of RGD-alginate containing smooth muscle cells (SMCs) is introduced into channel structures made of agarose hydrogel, forming a cell-embedding Ca-alginate hydrogel layer with a thickness of several hundred micrometers on the channel surface because of the Ca(2+) ions diffused from the agarose hydrogel matrix. Next, endothelial cells (ECs) are introduced and cultured for up to seven days to form hierarchically organized, multilayered vascular tissues. The factors affecting the thickness of the Ca-alginate hydrogel layer, and prepared several types of microchannels with different morphologies are examined. The fabricated vascular tissue models are easily recovered from the channel by simply detaching the agarose hydrogel plates. In addition, the effect of O2 tension (20 or 80%) on the viability and elastin production of SMCs during the perfusion culture is evaluated. This technique would pave a new way for vascular tissue engineering because it enables the facile production of morphologically in vivo vascular tissue-like structures that can be employed for various biomedical applications.

  13. Mold and Crucible Coatings (United States)


    34;" -"""-"’" " " ""’’ "" "" ’"" ’ j * AD I. AT)-E 9 7 W CONTRACTOR REPORT ARCCD-CR-86007 MOLD AND CRUCIBLE COATINGS Sylvia J. Canino Arthur L. Geary Nuclear...IFnlRpr April 1984_-_December 198, .. AUTNORfo) S. CONTRACT on CRAM? # "I MWef(e)I Sylvia J. Canino and Arthur L. Geary DAAK1O-84-C-0056 PERFORMING

  14. Nanofabrication with molds & stamps

    Directory of Open Access Journals (Sweden)

    Byron D. Gates


    Full Text Available A number of methods can be used to fabricate patterns with features having dimensions <100 nm. These techniques, however, can require specialized equipment and are often restricted to a cleanroom environment. Nanofabrication can be made accessible to multiple users by using elastomeric molds or stamps to transfer high-resolution patterns into other materials. These techniques are inexpensive and can transfer patterns into functional materials and onto a number of surfaces. This review describes recent advances in fabricating nanostructures using these techniques.

  15. Injection Compression Molding of Replica Molds for Nanoimprint Lithography

    Directory of Open Access Journals (Sweden)

    Keisuke Nagato


    Full Text Available As a breakthrough in the cost and durability of molds for nanoimprint lithography (NIL, replica molds are fabricated by injection compression molding (ICM. ICM is commonly used for optical disks such as DVDs or Blu-ray disks and is also a practical fabrication method for nanostructures. In this paper, I successfully demonstrated the fabrication of cycloolefin polymer replica molds with structures smaller than 60 nm by ICM. Furthermore, ultraviolet (UV-NIL using these replica molds was demonstrated. UV-cured resist was replicated over an area of 60 mm diameter. The degree of replication by UV-NIL in the first usage of each replica mold had good repeatability. Because ICM is a high-throughput, low-cost process, the replica mold can be disposed of after a certain time for UV-NIL. This method leads to a high-integrity UV-NIL process of patterned media because multiple large-area replica molds can be fabricated simultaneously.

  16. Enhanced Injection Molding Simulation of Advanced Injection Molds

    Directory of Open Access Journals (Sweden)

    Béla Zink


    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.

  17. Mold Materials For Permanent Molding of Aluminum Alloys

    Energy Technology Data Exchange (ETDEWEB)

    John F Wallace; David Schwam; Wen Hong


    A test that involves immersion of the potential mod materials for permanent molds has been developed that provides a thermal cycle that is similar to the experienced during casting of aluminum in permanent molds. This test has been employed to determine the relative thermal fatigue resistance of several different types of mold materials. Four commercial mold coatings have been evaluated for their insulating ability, wear resistance and roughness. The results indicate that composition and structure of the mold materials have considerable effect on their thermal fatigue cracking behavior. Irons with a gray iron structure are the most prone to thermal fatigue cracking followed by compacted graphite irons with the least thermal fatigue cracking of the cast irons experienced by ductile iron. The composition of these various irons affects their behavior.

  18. A new preclinical 3-dimensional agarose colony formation assay. (United States)

    Kajiwara, Yoshinori; Panchabhai, Sonali; Levin, Victor A


    The evaluation of new drug treatments and combination treatments for gliomas and other cancers requires a robust means to interrogate wide dose ranges and varying times of drug exposure without stain-inactivation of the cells (colonies). To this end, we developed a 3-dimensional (3D) colony formation assay that makes use of GelCount technology, a new cell colony counter for gels and soft agars. We used U251MG, SNB19, and LNZ308 glioma cell lines and MiaPaCa pancreas adenocarcinoma and SW480 colon adenocarcinoma cell lines. Colonies were grown in a two-tiered agarose that had 0.7% agarose on the bottom and 0.3% agarose on top. We then studied the effects of DFMO, carboplatin, and SAHA over a 3-log dose range and over multiple days of drug exposure. Using GelCount we approximated the area under the curve (AUC) of colony volumes as the sum of colony volumes (microm2xOD) in each plate to calculate IC50 values. Adenocarcinoma colonies were recognized by GelCount scanning at 3-4 days, while it took 6-7 days to detect glioma colonies. The growth rate of MiaPaCa and SW480 cells was rapid, with 100 colonies counted in 5-6 days; glioma cells grew more slowly, with 100 colonies counted in 9-10 days. Reliable log dose versus AUC curves were observed for all drugs studied. In conclusion, the GelCount method that we describe is more quantitative than traditional colony assays and allows precise study of drug effects with respect to both dose and time of exposure using fewer culture plates.

  19. Growth in agarose of human cells infected with cytomegalovirus. (United States)

    Lang, D J; Montagnier, L; Latarjet, R


    After infection by human cytomegalovirus (CMV), human diploid fibroblasts could grow in agarose medium for several generations. Clones of infected cells grew for weeks, although in every case they ultimately underwent lysis owing to the cytopathic effect of the virus. Virus was inoculated at high dilution and after UV irradiation in an effort to derive cells infected with noninfectious defective particles still capable of inducing cell stimulation. Dilute or irradiated virus occasionally yielded large colonies of replicating cells, although permanent transformation was not observed. One clone derived from UV-CMV-infected cells was passaged four times before undergoing lysis. During these passages the cells exhibited alterations in morphology and orientation.

  20. Orientation of the agarose gel matrix in pulsed electric fields.


    Stellwagen, J; Stellwagen, N C


    The technique of transient electric birefringence was used to investigate the effect of pulsed electric fields on the orientation of the agarose gel matrix. Orientation of the gel was observed at all electric field strengths. Very slow, time-dependent effects were observed when pulses of 10-100 V/cm were applied to 1% gels for 0.5-2 seconds, indicating that domains of the matrix were being oriented by the electric field. The sign of the birefringence reversed when the direction of the applied...

  1. Thermophilic molds: Biology and applications. (United States)

    Singh, Bijender; Poças-Fonseca, Marcio J; Johri, B N; Satyanarayana, Tulasi


    Thermophilic molds thrive in a variety of natural habitats including soils, composts, wood chip piles, nesting materials of birds and other animals, municipal refuse and others, and ubiquitous in their distribution. These molds grow in simple media containing carbon and nitrogen sources and mineral salts. Polyamines are synthesized in these molds and the composition of lipids varies considerably, predominantly containing palmitic, oleic and linoleic acids with low levels of lauric, palmiotoleic and stearic acids. Thermophilic molds are capable of efficiently degrading organic materials by secreting thermostable enzymes, which are useful in the bioremediation of industrial wastes and effluents that are rich in oil, heavy metals, anti-nutritional factors such as phytic acid and polysaccharides. Thermophilic molds synthesize several antimicrobial substances and biotechnologically useful miscellaneous enzymes. The analysis of genomes of thermophilic molds reveals high G:C contents, shorter introns and intergenic regions with lesser repetitive sequences, and further confirms their ability to degrade agro-residues efficiently. Genetic engineering has aided in ameliorating the characteristics of the enzymes of thermophilic molds. This review is aimed at focusing on the biology of thermophilic molds with emphasis on recent developments in the analysis of genomes, genetic engineering and potential applications.

  2. [Preparation, characterization and surface-enhanced Raman properties of agarose gel/gold nanoparticles hybrid]. (United States)

    Ma, Xiao-yuan; Liu, Ying; Wang, Zhou-ping


    Agarose gel/gold nanoparticles hybrid was prepared by adding gold nanoparticles to preformed agarose gel. Naniocomposite structures and properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV-Vis-NIR absorption spectroscopy. Experimental data indicated a uniform distribution of gold nanoparticles adsorbed on agarose gel network And the excellent optical absorption properties were shown. Based on the swelling-contraction characteristics of agarose gel and the adjustable localized surface plasmon resonance (LSPR) of the gold nanoparticles, the nano-composites were used as surface enhanced Raman scattering (SERS) substrate to detect the Raman signal molecules Nile blue A. Results revealed that the porous structure of the agarose gel provided a good carrier for the enrichment of the gold nanoparticles. The gold nanoparticles dynamic hot-spot effect arising from the agarose gel contraction loss of water in the air greatly enhanced the Raman signal.

  3. Handwashing compliance. (United States)

    Antoniak, Jeannie


    Undeniably, handwashing remains the single most effective and cost-efficient method for preventing and reducing the transmission of nosocomial infections. Yet the rates and outbreaks of nosocomial infections in Canadian and international healthcare institutions continue to increase. Shaikh Khalifa Medical Center developed and implemented a multidisciplinary approach to address the challenges of handwashing compliance among nurses and healthcare workers in its workplace setting. Supported by evidence-based research, the approach consisted of three components: collaboration, implementation and evaluation. The use of the alcohol-based hand rub sanitizer or "solution" was integral to the multidisciplinary approach. Ongoing education, communication and a committed leadership were essential to promote and sustain handwashing compliance.

  4. Using Linear Agarose Channels to Study Drosophila Larval Crawling Behavior. (United States)

    Sun, Xiao; Heckscher, Ellie S


    Drosophila larval crawling is emerging as a powerful model to study neural control of sensorimotor behavior. However, larval crawling behavior on flat open surfaces is complex, including: pausing, turning, and meandering. This complexity in the repertoire of movement hinders detailed analysis of the events occurring during a single crawl stride cycle. To overcome this obstacle, linear agarose channels were made that constrain larval behavior to straight, sustained, rhythmic crawling. In principle, because agarose channels and the Drosophila larval body are both optically clear, the movement of larval structures labeled by genetically-encoded fluorescent probes can be monitored in intact, freely-moving larvae. In the past, larvae were placed in linear channels and crawling at the level of whole organism, segment, and muscle were analyzed(1). In the future, larvae crawling in channels can be used for calcium imaging to monitor neuronal activity. Moreover, these methods can be used with larvae of any genotype and with any researcher-designed channel. Thus the protocol presented below is widely applicable for studies using the Drosophila larva as a model to understand motor control.

  5. 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...

  6. 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)


    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.

  7. Thermoresponsive chitosan-agarose hydrogel for skin regeneration. (United States)

    Miguel, Sónia P; Ribeiro, Maximiano P; Brancal, Hugo; Coutinho, Paula; Correia, Ilídio J


    Healing enhancement and pain control are critical issues on wound management. So far, different wound dressings have been developed. Among them, hydrogels are the most applied. Herein, a thermoresponsive hydrogel was produced using chitosan (deacetylation degree 95%) and agarose. Hydrogel bactericidal activity, biocompatibility, morphology, porosity and wettability were characterized by confocal microscopy, MTS assay and SEM. The performance of the hydrogel in the wound healing process was evaluated through in vivo assays, during 21 days. The attained results revealed that hydrogel has a pore size (90-400 μm) compatible with cellular internalization and proliferation. A bactericidal activity was observed for hydrogels containing more than 188 μg/mL of chitosan. The improved healing and the lack of a reactive or a granulomatous inflammatory reaction in skin lesions treated with hydrogel demonstrate its suitability to be used in a near future as a wound dressing.

  8. Cloning of DNA fragments: ligation reactions in agarose gel. (United States)

    Furtado, Agnelo


    Ligation reactions to ligate a desired DNA fragment into a vector can be challenging to beginners and especially if the amount of the insert is limiting. Although additives known as crowding agents, such as PEG 8000, added to the ligation mixes can increase the success one has with ligation reactions, in practice the amount of insert used in the ligation can determine the success or the failure of the ligation reaction. The method described here, which uses insert DNA in gel slice added directly into the ligation reaction, has two benefits: (a) using agarose as the crowding agent and (b) reducing steps of insert purification. The use of rapid ligation buffer and incubation of the ligation reaction at room temperature greatly increase the efficiency of the ligation reaction even for blunt-ended ligation.

  9. Growth in Agarose of Human Cells Infected with Cytomegalovirus (United States)

    Lang, David J.; Montagnier, Luc; Latarjet, Raymond


    After infection by human cytomegalovirus (CMV), human diploid fibroblasts could grow in agarose medium for several generations. Clones of infected cells grew for weeks, although in every case they ultimately underwent lysis owing to the cytopathic effect of the virus. Virus was inoculated at high dilution and after UV irradiation in an effort to derive cells infected with noninfectious defective particles still capable of inducing cell stimulation. Dilute or irradiated virus occasionally yielded large colonies of replicating cells, although permanent transformation was not observed. One clone derived from UV-CMV-infected cells was passaged four times before undergoing lysis. During these passages the cells exhibited alterations in morphology and orientation. Images PMID:4367907

  10. Onychomycosis due to opportunistic molds*


    Martínez-Herrera, Erick Obed; Arroyo-Camarena,Stefanie; Tejada-García, Diana Luz; Porras-López, Carlos Francisco; Arenas, Roberto


    Abstract BACKGROUND: Onychomycosis are caused by dermatophytes and Candida, but rarely by non- dermatophyte molds. These opportunistic agents are filamentous fungi found as soil and plant pathogens. OBJECTIVES: To determine the frequency of opportunistic molds in onychomycosis. METHODS: A retrospective analysis of 4,220 cases with onychomycosis, diagnosed in a 39-month period at the Institute of Dermatology and Skin surgery "Prof. Dr. Fernando A. Cordero C." in Guatemala City, and confirmed w...

  11. A Quick, Cost-Free Method of Purification of DNA Fragments from Agarose Gel

    Directory of Open Access Journals (Sweden)

    Yuan Sun, Kannappan Sriramajayam, Dianzhong Luo, D. Joshua Liao


    Full Text Available In this short communication we report a quick, cost-free method of purification of DNA fragments from agarose gel. Unlike those procedures that involve commercial kits, this method uses glass wool or absorbent cotton to filter agarose gel during a quick spinning-down of DNA, thus significantly simplifying the routine practice of many molecular biologists and decreasing the cost.

  12. Crosslinked agarose encapsulated sorbents resistant to steam sterilization. Preparation and mechanical properties

    NARCIS (Netherlands)

    Koning, de Henk W.M.; Chamuleau, Rob A.F.M.; Bantjes, Adriaan


    The application of agarose in hemoperfusion is hampered by the lack of a suitable sterilization method. A technique has been developed for the crosslinking of agarose encapsulated sorbents by the reaction with 1,3-dichloro-2-propanol (DCP) under strong alkaline conditions. A twofold molar excess of

  13. Prevention of Mold Contamination : Ozone Treatment


    Nakarmi, Kanchan


    Mold is a common pest that can cause diseases and decay property. Moreover, certain mold can produce toxic chemicals which leads directly or indirectly to additional health impacts and economic losses. Therefore, prevention of mold growth is a major concern, and disinfection of mold has become a center of attention. The purpose of this thesis was to study about the effect of ozone in the disinfection of mold and the method of producing ozone. The usage of ozone for disinfection in in...

  14. DNA recovery from agarose gels with a simple centrifuge-driven sephadex filtration

    Institute of Scientific and Technical Information of China (English)

    Niu Chen; Li Yun


    Conventional methods of DNA recovery from agarose gel generally require expensive equipment, extended elution times,or considerable handling of the sample after elution. We developed a simple protocol for a quick and effective recovery of DNA from agarose gels with good yield and quality. Using a Sephadex resin filled spin column, DNA fragments of 500 bp to 6 kb in an agarose gel slice were easily recovered by a 2 min centrifugation. The recovery efficiencies were over 40%-50% and the eluted DNA can be used directly for downstream application, such as polymerase chain reactions (PCR) and restriction enzyme digestion. This method could also be used to recover large DNA fragment (48 kb) without degradation. The use of Sephadex helps to remove small molecular impurities from agarose and it also reduces the chance of clogging the column filter caused by direct contact with agarose.

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

    DEFF Research Database (Denmark)

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


    We demonstrate the replication of nanosized pillars in polymer (cyclic olefin copolymer) by injection molding using nanostructured thermally cured hydrogen silsesquioxane (HSQ) ceramic coatings on stainless steel mold inserts with mold nanostructures produced by a simple embossing process...

  16. Synthesis of agarose-metal/semiconductor nanoparticles having superior bacteriocidal activity and their simple conversion to metal-carbon composites

    Indian Academy of Sciences (India)

    K K R Datta; B Srinivasan; H Balaram; M Eswaramoorthy


    Agarose, a naturally occurring biopolymer is used for the stabilization of metal, semiconductor nanoparticles. Ag and Cu nanoparticles stabilized in agarose matrix show excellent antibacterial activity against E. coli bacteria. The well dispersed metal nanoparticles within the agarose composite films can be readily converted to carbon-metal composites of catalytic importance.

  17. 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...... the molding process. The main advantage with this method is that surface treatments and chemical additives are avoided, which minimizes health risks and simplifies recycling. Another advantage is that the unique technology enables nanostructuring of free form molded parts. The functional surfaces can have...

  18. Laminin active peptide/agarose matrices as multifunctional biomaterials for tissue engineering. (United States)

    Yamada, Yuji; Hozumi, Kentaro; Aso, Akihiro; Hotta, Atsushi; Toma, Kazunori; Katagiri, Fumihiko; Kikkawa, Yamato; Nomizu, Motoyoshi


    Cell adhesive peptides derived from extracellular matrix components are potential candidates to afford bio-adhesiveness to cell culture scaffolds for tissue engineering. Previously, we covalently conjugated bioactive laminin peptides to polysaccharides, such as chitosan and alginate, and demonstrated their advantages as biomaterials. Here, we prepared functional polysaccharide matrices by mixing laminin active peptides and agarose gel. Several laminin peptide/agarose matrices showed cell attachment activity. In particular, peptide AG73 (RKRLQVQLSIRT)/agarose matrices promoted strong cell attachment and the cell behavior depended on the stiffness of agarose matrices. Fibroblasts formed spheroid structures on the soft AG73/agarose matrices while the cells formed a monolayer with elongated morphologies on the stiff matrices. On the stiff AG73/agarose matrices, neuronal cells extended neuritic processes and endothelial cells formed capillary-like networks. In addition, salivary gland cells formed acini-like structures on the soft matrices. These results suggest that the peptide/agarose matrices are useful for both two- and three-dimensional cell culture systems as a multifunctional biomaterial for tissue engineering.

  19. In vitro culture of hybridoma cells in agarose beads producing antibody secretion for two weeks. (United States)

    Cadic, C; Dupuy, B; Pianet, I; Merle, M; Margerin, C; Bezian, J H


    A new process for embedding cells in agarose is described. Beads were obtained by extruding an ultralow gelling temperature agarose solution in a capillary containing a hydrophobic medium flowthrough. The toxicity of the procedure has been evaluated by monitoring the energy status of agarose-embedded C(6) glioma cells with (31)P nuclear magnetic resonance (NMR). Suspension and microbead cultures of hybridoma cell line were compared. In suspension culture the number of cells and the antibody concentrations increased for 5 days before the stationary phase began, when the cultures were stopped. In agarose bead cultures, the gel provided an enormous support surface area (50 m(2)/ mL of gel). It was possible to seed 20-fold more cells. The gel pressure modified the proliferative process and antibody pattern secretion. In particular, the antibodies could be harvested for two weeks.

  20. Searching for the best agarose candidate from genusGracilaria,Eucheuma,Gelidium and local brands

    Institute of Scientific and Technical Information of China (English)

    Ferry Efendi; Retno Handajani; Nursalam Nursalam


    Objective:To explore the potential of local agar of genusGracilaria,Eucheuma,Gelidium and local brandsas an alternative for imported agarose forDNA electrophoresis, and to examine their ability related to separation and migration ofDNA fragments inDNA electrophoresis. Methods:Their performance at various concentrations were compared via an experimental study with a specific brand of imported commercial agarose used in molecular biology research. The measured variables were separation and migration during electrophoresis of a DNA fragment. Results: The local agar genusGracilaria gigas,Gelidium, brand "B" and brand "S" could separateDNA fragments at a concentration between 1% and 2%, with an optimum concentration of 2% w/v, as good as a specific brand of imported commercial agarose. Conclusions:Their performance were very close to that of commercial agarose and can still be improved by further agar purification as well as by pH and sulfur control.

  1. Searching for the best agarose candidate from genus Gracilaria, Eucheuma,Gelidium and local brands简

    Institute of Scientific and Technical Information of China (English)

    Ferry; Efendi; Retno; Handajani; Nursalam; Nursalam


    Objective: To explore the potential of local agar of genus Gracilaria, Eucheuma,Gelidium and local brands as an alternative for imported agarose for DNA electrophoresis, and to examine their ability related to separation and migration of DNA fragments in DNA electrophoresis.Methods: Their performance at various concentrations were compared via an experimental study with a specific brand of imported commercial agarose used in molecular biology research. The measured variables were separation and migration during electrophoresis of a DNA fragment.Results: The local agar genus Gracilaria gigas, Gelidium, brand “B” and brand “S”could separate DNA fragments at a concentration between 1% and 2%, with an optimum concentration of 2% w/v, as good as a specific brand of imported commercial agarose.Conclusions: Their performance were very close to that of commercial agarose and can still be improved by further agar purification as well as by p H and sulfur control.

  2. Surface microstructure replication in injection molding

    DEFF Research Database (Denmark)

    Theilade, Uffe Arlø; Hansen, Hans Nørgaard


    In recent years, polymer components with surface microstructures have been in rising demand for applications such as lab-on-a-chip and optical components. Injection molding has proven to be a feasible and efficient way to manufacture such components. In injection molding, the mold surface topogra...

  3. Injection Molding of Plastics from Agricultural Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, M.; Ruan, R.


    The objective of this research was to conduct a systematic study to relate injection molding parameters to properties of blends of starch and synthetic polymer. From this study, we wished to develop a thorough understanding of the injection molding process and gain significant insight into designing molds and aiding in developing products cheaply and efficiently.

  4. Planning an Injection Mold Design Training Program. (United States)

    Allyn, Edward P.

    With the increased use of plastics worldwide the shortage of trained personnel in moldmaking and design for plastic injection molds is becoming critical. Local schools and community colleges should provide courses in mold design and mold making, since most workers presently learn while working under experienced designers on the job. Following this…

  5. Is Mold the New Asbestos? (United States)

    Colgan, Craig


    Mold and indoor air quality (IAQ) are matters of major concern to architects and their educational clients. The Environmental Protection Agency's Indoor Air Quality Tools for Schools program offers help to districts seeking to tackle IAQ issues. Strengthening community relations is one way to be ready in case of a bad environmental or IAQ report.…

  6. Stochastic resin transfer molding process

    CERN Document Server

    Park, M


    We consider one-dimensional and two-dimensional models of stochastic resin transfer molding process, which are formulated as random moving boundary problems. We study their properties, analytically in the one-dimensional case and numerically in the two-dimensional case. We show how variability of time to fill depends on correlation lengths and smoothness of a random permeability field.

  7. Agarose gel shift assay reveals that calreticulin favors substrates with a quaternary structure in solution

    DEFF Research Database (Denmark)

    Boelt, Sanne Grundvad; Houen, Gunnar; Højrup, Peter


    Here we present an agarose gel shift assay that, in contrast to other electrophoresis approaches, is loaded in the center of the gel. This allows proteins to migrate in either direction according to their isoelectric points. Therefore, the presented assay enables a direct visualization, separation...... structure. It is also demonstrated that the agarose gel shift assay is useful in the study of other protein interactions and can be used as an alternative method to native polyacrylamide gel electrophoresis....

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


    Hobæk, Thor Christian; Matschuk, Maria; Kafka, Jan; Pranov, Henrik J.; Larsen, Niels Bent


    We demonstrate the replication of nanosized pillars in polymer (cyclic olefin copolymer) by injection molding using nanostructured thermally cured hydrogen silsesquioxane (HSQ) ceramic coatings on stainless steel mold inserts with mold nanostructures produced by a simple embossing process. At isothermal mold conditions, the average pillar height increases by up to 100% and a more uniform height distribution is observed compared to a traditional metal mold insert. Thermal heat transfer simulat...

  9. Implementation of Molding Constraints in Topology Optimization

    DEFF Research Database (Denmark)

    Marx, S.; Kristensen, Anders Schmidt


    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...

  10. Precision injection molding of freeform optics (United States)

    Fang, Fengzhou; Zhang, Nan; Zhang, Xiaodong


    Precision injection molding is the most efficient mass production technology for manufacturing plastic optics. Applications of plastic optics in field of imaging, illumination, and concentration demonstrate a variety of complex surface forms, developing from conventional plano and spherical surfaces to aspheric and freeform surfaces. It requires high optical quality with high form accuracy and lower residual stresses, which challenges both optical tool inserts machining and precision injection molding process. The present paper reviews recent progress in mold tool machining and precision injection molding, with more emphasis on precision injection molding. The challenges and future development trend are also discussed.

  11. Silane based coating of aluminium mold

    DEFF Research Database (Denmark)


    comprising a chemically bonded monolayer of silane compounds on the at least one surface wherein the silane is a halogenated silane. The at least one surface coated with the anti-stiction coating may be configured to withstand an injection molding process at a pressure above 100 MPa. Furthermore, a mold......A method of preparing an aluminum mold for injection molding is provided, the method comprises the steps of providing an aluminum mold having a least one surface, subjecting the at least one surface to a gas or liquid phase silane to thereby form an anti-stiction coating, the anti-stiction coating...... 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...

  12. Numerical Analysis of Mold Deformation Including Plastic Melt Flow During Injection Molding

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Joon Tae; Lee, Bong-Kee [Chonnam National University, Gwangju (Korea, Republic of)


    In the present study, a numerical analysis of an injection molding process was conducted for predicting the mold deformation considering non-Newtonian flow, heat transfer, and structural behavior. The accurate prediction of mold deformation during the filling stage is important to successfully design and manufacture a precision injection mold. While the local mold deformation can be caused by various factors, a pressure induced by the polymer melt is considered to be one of the most significant ones. In this regard, the numerical simulation considering both the melt filling and the mold deformation was carried out. A mold core for a 2D axisymmetric center-gated disk was used for the demonstration of the present study. The flow behavior inside the mold cavity and temperature distribution were analyzed along with the core displacement. Also, a Taguchi method was employed to investigate the influence of the relevant parameters including flow velocity, mold core temperature, and melt temperature.

  13. Compression molding of aerogel microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Pekala, Richard W. (Pleasant Hill, CA); Hrubesh, Lawrence W. (Pleasanton, CA)


    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50-800 kg/m.sup.3 (0.05-0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization.

  14. Compression molding of aerogel microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Pekala, R.W.; Hrubesh, L.W.


    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner is disclosed. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50--800 kg/m{sup 3} (0.05--0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization. 4 figs.

  15. Onychomycosis due to opportunistic molds* (United States)

    Martínez-Herrera, Erick Obed; Arroyo-Camarena, Stefanie; Tejada-García, Diana Luz; Porras-López, Carlos Francisco; Arenas, Roberto


    BACKGROUND: Onychomycosis are caused by dermatophytes and Candida, but rarely by non- dermatophyte molds. These opportunistic agents are filamentous fungi found as soil and plant pathogens. OBJECTIVES: To determine the frequency of opportunistic molds in onychomycosis. METHODS: A retrospective analysis of 4,220 cases with onychomycosis, diagnosed in a 39-month period at the Institute of Dermatology and Skin surgery "Prof. Dr. Fernando A. Cordero C." in Guatemala City, and confirmed with a positive KOH test and culture. RESULTS: 32 cases (0.76%) of onychomycosis caused by opportunistic molds were confirmed. The most affected age group ranged from 41 to 65 years (15 patients, 46.9%) and females were more commonly affected (21 cases, 65.6%) than males. Lateral and distal subungual onychomycosis (OSD-L) was detected in 20 cases (62.5%). The microscopic examination with KOH showed filaments in 19 cases (59.4%), dermatophytoma in 9 cases (28.1%), spores in 2 cases (6.25%), and filaments and spores in 2 cases (6.25%). Etiologic agents: Aspergillus sp., 11 cases (34.4%); Scopulariopsis brevicaulis, 8 cases (25.0%); Cladosporium sp., 3 cases (9.4%); Acremonium sp., 2 cases (6.25%); Paecilomyces sp., 2 cases (6.25%); Tritirachium oryzae, 2 cases (6.25%); Fusarium sp., Phialophora sp., Rhizopus sp. and Alternaria alternate, 1 case (3.1%) each. CONCLUSIONS: We found onychomycosis by opportunistic molds in 0.76% of the cases and DLSO was present in 62.5%. The most frequent isolated etiological agents were: Aspergillus sp. and Scopulariopsis brevicaulis. PMID:26131862

  16. Agarose-based microfluidic device for point-of-care concentration and detection of pathogen. (United States)

    Li, Yiwei; Yan, Xinghua; Feng, Xiaojun; Wang, Jie; Du, Wei; Wang, Yachao; Chen, Peng; Xiong, Liang; Liu, Bi-Feng


    Preconcentration of pathogens from patient samples represents a great challenge in point-of-care (POC) diagnostics. Here, a low-cost, rapid, and portable agarose-based microfluidic device was developed to concentrate biological fluid from micro- to picoliter volume. The microfluidic concentrator consisted of a glass slide simply covered by an agarose layer with a binary tree-shaped microchannel, in which pathogens could be concentrated at the end of the microchannel due to the capillary effect and the strong water permeability of the agarose gel. The fluorescent Escherichia coli strain OP50 was used to demonstrate the capacity of the agarose-based device. Results showed that 90% recovery efficiency could be achieved with a million-fold volume reduction from 400 μL to 400 pL. For concentration of 1 × 10(3) cells mL(-1) bacteria, approximately ten million-fold enrichment in cell density was realized with volume reduction from 100 μL to 1.6 pL. Urine and blood plasma samples were further tested to validate the developed method. In conjugation with fluorescence immunoassay, we successfully applied the method to the concentration and detection of infectious Staphylococcus aureus in clinics. The agarose-based microfluidic concentrator provided an efficient approach for POC detection of pathogens.

  17. Gating of Permanent Molds for ALuminum Casting

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang


    This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

  18. Plasticizing effect of choline chloride/urea eutectic-based ionic liquid on physicochemical properties of agarose films

    Directory of Open Access Journals (Sweden)

    Ahmad Adlie Shamsuri


    Full Text Available Agarose films were formed with the addition of 30 to 70 wt% choline chloride/urea eutectic-based ionic liquid (ChCl/Urea. The ChCl/Urea was prepared through complexation at a 1:2 mole ratio. The films were prepared by dissolving ChCl/Urea in distilled water followed by dispersion of the agarose at 95 °C. The solution was gelled at room temperature, and the formed gel was dried in an oven overnight at 70 °C. Mechanical testing indicated that the agarose film containing 60 wt% ChCl/Urea had higher tensile extension and tensile strain at break compared to the pristine agarose film. The addition of ChCl/Urea also reduced the glass transition temperature (Tg of agarose films. Cross-section SEM images of the agarose films showed that surface roughness disappeared with the incorporation of ChCl/Urea. FTIR spectra confirmed the presence of intermolecular hydrogen bonding between agarose and ChCl/Urea. XRD patterns demonstrated that an amorphous phase was obtained when ChCl/Urea was added. Agarose films containing more ChCl/Urea exhibited higher transparency, as measured by a UV-Vis spectrometer. In summary, the physicochemical properties of agarose films were evidently affected by the incorporation of the ChCl/Urea as a plasticizing agent.

  19. 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...

  20. Agarose- and alginate-based biopolymers for sample preparation: Excellent green extraction tools for this century. (United States)

    Sanagi, Mohd Marsin; Loh, Saw Hong; Wan Ibrahim, Wan Nazihah; Pourmand, Neda; Salisu, Ahmed; Wan Ibrahim, Wan Aini; Ali, Imran


    Recently, there has been considerable interest in the use of miniaturized sample preparation techniques before the chromatographic monitoring of the analytes in unknown complex compositions. The use of biopolymer-based sorbents in solid-phase microextraction techniques has achieved a good reputation. A great variety of polysaccharides can be extracted from marine plants or microorganisms. Seaweeds are the major sources of polysaccharides such as alginate, agar, agarose, as well as carrageenans. Agarose and alginate (green biopolymers) have been manipulated for different microextraction approaches. The present review is focused on the classification of biopolymer and their applications in multidisciplinary research. Besides, efforts have been made to discuss the state-of-the-art of the new microextraction techniques that utilize commercial biopolymer interfaces such as agarose in liquid-phase microextraction and solid-phase microextraction.

  1. Porous media heat transfer for injection molding

    Energy Technology Data Exchange (ETDEWEB)

    Beer, Neil Reginald


    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.

  2. Deadline Compliance Status Reports (United States)

    Department of Housing and Urban Development — These monthly Deadline Compliance Status Reports assist Participating Jurisdictions and HUD Field Offices in monitoring compliance with the 2-year commitment and...

  3. Enzymatic liquefaction of agarose above the sol-gel transition temperature using a thermostable endo-type β-agarase, Aga16B. (United States)

    Kim, Jung Hyun; Yun, Eun Ju; Seo, Nari; Yu, Sora; Kim, Dong Hyun; Cho, Kyung Mun; An, Hyun Joo; Kim, Jae-Han; Choi, In-Geol; Kim, Kyoung Heon


    The main carbohydrate of red macroalgae is agarose, a heterogeneous polysaccharide composed of D-galactose and 3,6-anhydro-L-galactose. When saccharifying agarose by enzymes, the unique physical properties of agarose, namely the sol-gel transition and the near-insolubility of agarose in water, limit the accessibility of agarose to the enzymes. Due to the lower accessibility of agarose to enzymes in the gel state than to the sol state, it is important to prevent the sol-gel transition by performing the enzymatic liquefaction of agarose at a temperature higher than the sol-gel transition temperature of agarose. In this study, a thermostable endo-type β-agarase, Aga16B, originating from Saccharophagus degradans 2-40(T), was characterized and introduced in the liquefaction process. Aga16B was thermostable up to 50 °C and depolymerized agarose mainly into neoagarooligosaccharides with degrees of polymerization 4 and 6. Aga16B was applied to enzymatic liquefaction of agarose at 45 °C, which was above the sol-gel transition temperature of 1 % (w/v) agarose (∼35 °C) when cooling agarose. This is the first systematic demonstration of enzymatic liquefaction of agarose, enabled by determining the sol-gel temperature of agarose under specific conditions and by characterizing the thermostability of an endo-type β-agarase.

  4. Analysis of optical properties in injection-molded and compression-molded optical lenses. (United States)

    Wang, Chung Yen; Wang, Pei Jen


    Numerical mold-flow simulations and experimental measurements for injection-molded lenses have been investigated in form accuracy on a two-cavity mold with various process conditions. First, form profiles of the molded lenses have been measured together with the corresponding simulated mold-temperature distribution and displacement distribution of the lens in the z direction. A flow-through type layout of cooling channels has been devised for balance of mold-temperature distribution in mold cavities with various parametric distances for assessments in uniformity of temperature distribution. Finally, a compression-molding process is proposed for the post-process of birefringence relaxation as well as adequate form accuracy of lenses. In conclusion, optimization of process parameters to achieve good form accuracy in a multicavity mold with symmetric geometry but nonuniform cooling conditions is difficult. A good design of cooling channels plus optimized process conditions could provide uniform mold-temperature distribution so that molded lenses of good quality would be possible. Then, the profile deviation of lenses could be further compensated by profile geometry corrections. In conclusion, the post-compression-molding process could make birefringence-free plastic lenses with good form accuracy.

  5. Comparison of viability of adipose-derived Mesenchymal stem cells on agarose and fibrin glue scaffolds

    Directory of Open Access Journals (Sweden)

    Farzaneh Tafvizi


    Full Text Available Background & aim: Utilizing tissue engineering techniques and designing similar structures of the damaged tissues require the use of tools such as scaffolds, cells, and bioactive molecules in vitro. Meanwhile, appropriate cell cultures with the ability to divide and differentiate on the natural scaffolds lacking features like immunogenicity and tumorgenesis is particularly important. Adipose tissue has attracted researchers’ attention due to its abundance of mesenchymal stem cells and its availability through a liposuction. The purpose of the present study was to investigate the reproducibility and viability of the adipose-derived stem cells on natural scaffolds of fibrin glue and agarose. Methods: In the present experimental study, the isolation and identification of the mesenchymal stem cells was performed on tissue obtained from liposuction. The tissues were extensively washed with PBS and were digested with collagenase I, then the mesenchymal stem cells were isolated. The cells were cultured in RPMI medium supplemented with antibiotic. Subsequently, the expression of cell surface markers including CD34, CD44, CD90, and CD105 were analyzed by flow cytometry to confirm the mesenchymal cells. After preparing fibrin glue and agarose scaffolds, the viability and proliferation of the adipose tissue-derived mesenchymal stem cells were examined at the period of 24, 48, and 72 hours by MTT and ELISA assays. The obtained results were analyzed by SPSS ver.19. Results: The results of adipose tissue-derived mesenchymal stem cells culture on the fibrin glue and agarose scaffolds indicated that cell viability on fibrin glue and agarose scaffold were 68.22% and 89.75% in 24 hrs, 64.04% and 66.97% in 48 hours, 222.87% and 1089.68% in 72 hours respectively. Significant proliferation and viability cells on a synthesized agarose scaffold were seen compared to the fibrin glue scaffold after 72 hrs. The viability of the cells significantly increased on the

  6. Micropatterning of a stretchable conductive polymer using inkjet printing and agarose stamping

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Hassager, Ole; Larsen, Niels Bent


    A highly conducting stretchable polymer material has been patterned using additive inkjet printing and by subtractive agarose stamping of a deactivation agent (hypochlorite). The material consisted of elastomeric polyurethane combined in an interpenetrating network with a conductive polymer, poly(3......,4-ethylenedioxythiophene) (PEDOT). The agarose stamping produced 50 μm wide conducting lines with high spatial fidelity. The deactivation agent was found to cause some degradation of the remaining conducting lines, as revealed by a stronger increase in resistance upon straining compared to the pristine polymer material...

  7. Ag-nanoparticle fractionation by low melting point agarose gel electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Guarrotxena, Nekane, E-mail: [Consejo Superior de Investigaciones Cientificas (CSIC), Instituto de Ciencia y Tecnologia de Polimeros (ICTP) (Spain); Braun, Gary [University of California, Santa Barbara, Department of Chemistry and Biochemistry (United States)


    The separation of surface-enhanced raman scattering (SERS)-active Ag-multi-nanoparticle (NP) assemblies by low melting point agarose gel electrophoresis was accomplished here by controlling surface charge using NP capping agents, and the pore size of agarose gel matrix. Detailed transmission electron microscopy analysis of excised gel fractions showed dimers and small clusters to have the greatest SERS activity and a mobility in between the monomers and large aggregates. This strategy enables one to: (1) stabilize small multispherical Ag clusters against further aggregation during purification; (2) fractionate and recover spherical assemblies by nuclearity; and (3) analyze SERS-enhancements for each fraction to optimize purification conditions.

  8. Mold (United States)

    ... all, may produce toxins or poisonous substances called mycotoxins that may cause effects in humans. Although there are many types of mycotoxins, aflatoxins are probably the best known and most ...

  9. 40 CFR 63.5714 - How do I demonstrate compliance if I use filled resins? (United States)


    ... use filled resins? 63.5714 Section 63.5714 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Molding Resin and Gel Coat Operations § 63.5714 How do I demonstrate compliance if I use filled resins? (a) If you are using a filled production resin or filled tooling resin, you must demonstrate...

  10. Mechanical Properties of Injection Molded and Compression Molded Samples from Nature-Butadiene Rubber

    Directory of Open Access Journals (Sweden)

    Skrobak Adam


    Full Text Available The aim of this paper is to show what extent there is an impact on the mechanical properties (tensile strength and tear strength of a standardized testing sample made of rubber compound based on nature rubber and butadiene rubber produced by injection molding in comparison with a sample produced by classic preparation (cutting out a compression molded plate according to the standard ISO 23529. For realization of this study it was necessary to design and produce an injection mold for all types testing samples. Subsequently, mechanical properties such as the tensile stress-strain and tear strenght of compression molded samples and injection molded samples were studied, compared and discussed.

  11. Nonlinear Modeling of a High Precision Servo Injection Molding Machine Including Novel Molding Approach

    Institute of Scientific and Technical Information of China (English)

    何雪松; 王旭永; 冯正进; 章志新; 杨钦廉


    A nonlinear mathematical model of the injection molding process for electrohydraulic servo injection molding machine (IMM) is developed.It was found necessary to consider the characteristics of asymmetric cylinder for electrohydraulic servo IMM.The model is based on the dynamics of the machine including servo valve,asymmetric cylinder and screw,and the non-Newtonian flow behavior of polymer melt in injection molding is also considered.The performance of the model was evaluated based on novel approach of molding - injection and compress molding,and the results of simulation and experimental data demonstrate the effectiveness of the model.

  12. The Thermal Distortion of a Funnel Mold (United States)

    Hibbeler, Lance C.; Thomas, Brian G.; Schimmel, Ronald C.; Abbel, Gert


    This article investigates the thermal distortion of a funnel mold for continuous casting of thin slabs and explores the implications on taper and solidification of the steel shell. The three-dimensional mold temperatures are calculated using shell-mold heat flux and cooling water profiles that were calibrated with plant measurements. The thermal stresses and distorted shape of the mold are calculated with a detailed finite-element model of a symmetric fourth of the entire mold and waterbox assembly, and they are validated with plant thermocouple data and measurements of the wear of the narrow-face copper mold plates. The narrow-face mold distorts into the typical parabolic arc, and the wide face distorts into a "W" shape owing to the large variation in bolt stiffnesses. The thermal expansion of the wide face works against the applied narrow-face taper and funnel effects, so the effect of thermal distortion must be considered to accurately predict the ideal mold taper.

  13. Nanostructuring steel for injection molding tools

    DEFF Research Database (Denmark)

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


    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...

  14. Mold Remediation in Schools and Commercial Buildings. (United States)

    Environmental Protection Agency, Washington, DC. Office of Radiation and Indoor Air.

    This document describes how to investigate and evaluate moisture and mold problems in educational facilities, and presents the key steps for implementing a remediation plan. A checklist is provided for conducting mold remediation efforts along with a resource list of helpful organizations and governmental agencies. Appendices contain a glossary,…

  15. Effect of alternation of agar and agarose on the green plant differentiation frequency of calli from wild rice

    Institute of Scientific and Technical Information of China (English)


    @@ In vitro culture of wild rice was difficult. Recently, we found that high agarose concentration of different media could improve the green plant differentiation frequency of calli from wild rice. We tested the effectiveness of alternation of agar and agarose in different media.

  16. The use of IR thermography to show the mold and part temperature evolution in injection molding (United States)

    Bula, Karol; Różański, Leszek; Marciniak-Podsadna, Lidia; Wróbel, Dawid


    This study concerns the application of infrared camera for injection molding analysis by measuring temperatures of both injection molded parts and injection mold cavities in a function of injection cycles. The mold with two cavities, differing in thickness (1 and 3 mm), and a cold direct runner was used. Isotactic polypropylene homopolymer was utilized to produce parts. Mold temperature was set at 22°C and controlled by a water chiller. Five measuring points were determined: SP1, SP2 (placed in the 3 mm cavity), SP3, SP4 (located in the 1 mm cavity) and SP5 around an injection molding gate. Our investigations showed that the highest temperature is localized around SP2 point and the lowest at SP4. Also, it was proved that even after 62 injection molding cycles, temperatures of cavities were not stable, revealing their further increase with each cycle.

  17. The use of IR thermography to show the mold and part temperature evolution in injection molding

    Directory of Open Access Journals (Sweden)

    Bula Karol


    Full Text Available This study concerns the application of infrared camera for injection molding analysis by measuring temperatures of both injection molded parts and injection mold cavities in a function of injection cycles. The mold with two cavities, differing in thickness (1 and 3 mm, and a cold direct runner was used. Isotactic polypropylene homopolymer was utilized to produce parts. Mold temperature was set at 22°C and controlled by a water chiller. Five measuring points were determined: SP1, SP2 (placed in the 3 mm cavity, SP3, SP4 (located in the 1 mm cavity and SP5 around an injection molding gate. Our investigations showed that the highest temperature is localized around SP2 point and the lowest at SP4. Also, it was proved that even after 62 injection molding cycles, temperatures of cavities were not stable, revealing their further increase with each cycle.

  18. IC chip stress during plastic package molding

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, D.W.; Benson, D.A.; Peterson, D.W.; Sweet, J.N.


    Approximately 95% of the world`s integrated chips are packaged using a hot, high pressure transfer molding process. The stress created by the flow of silica powder loaded epoxy can displace the fine bonding wires and can even distort the metalization patterns under the protective chip passivation layer. In this study the authors developed a technique to measure the mechanical stress over the surface of an integrated circuit during the molding process. A CMOS test chip with 25 diffused resistor stress sensors was applied to a commercial lead frame. Both compression and shear stresses were measured at all 25 locations on the surface of the chip every 50 milliseconds during molding. These measurements have a fine time and stress resolution which should allow comparison with computer simulation of the molding process, thus allowing optimization of both the manufacturing process and mold geometry.

  19. Enhanced Resolution of DNA Separation Using Agarose Gel Electrophoresis Doped with Graphene Oxide (United States)

    Li, Jialiang; Yang, Yushi; Mao, Zhou; Huang, Wenjie; Qiu, Tong; Wu, Qingzhi


    In this work, a novel agarose gel electrophoresis strategy has been developed for separation of DNA fragments by doping graphene oxide (GO) into agarose gel. The results show that the addition of GO into agarose gel significantly improved the separation resolution of DNA fragments by increasing the shift distances of both the single DNA fragments and the adjacent DNA fragments and completely eliminating the background noise derived from the diffusion of the excessive ethidium bromide (EB) dye in the gel after electrophoresis. The improved resolution of DNA fragments in GO-doped agarose gel could be attributed to the successive adsorption-desorption processes between DNA fragments and GO sheets, while the elimination of the background noise could be attributed to the adsorption of the excessive EB dye on the surface of GO sheets and high fluorescence quenching efficiency of GO. These results provide promising potential for graphene and its derivate utilized in various electrophoresis techniques for separation and detection of DAN fragments and other biomolecules.

  20. Drying techniques for the visualisation of agarose-based chromatography media by scanning electron microscopy. (United States)

    Nweke, Mauryn C; Turmaine, Mark; McCartney, R Graham; Bracewell, Daniel G


    The drying of chromatography resins prior to scanning electron microscopy is critical to image resolution and hence understanding of the bead structure at sub-micron level. Achieving suitable drying conditions is especially important with agarose-based chromatography resins, as over-drying may cause artefact formation, bead damage and alterations to ultrastructural properties; and under-drying does not provide sufficient resolution for visualization under SEM. This paper compares and contrasts the effects of two drying techniques, critical point drying and freeze drying, on the morphology of two agarose based resins (MabSelect™/dw ≈85 µm and Capto™ Adhere/dw ≈75 µm) and provides a complete method for both. The results show that critical point drying provides better drying and subsequently clearer ultrastructural visualization of both resins under SEM. Under this protocol both the polymer fibers (thickness ≈20 nm) and the pore sizes (diameter ≈100 nm) are clearly visible. Freeze drying is shown to cause bead damage to both resins, but to different extents. MabSelect resin encounters extensive bead fragmentation, whilst Capto Adhere resin undergoes partial bead disintegration, corresponding with the greater extent of agarose crosslinking and strength of this resin. While freeze drying appears to be the less favorable option for ultrastructural visualization of chromatography resin, it should be noted that the extent of fracturing caused by the freeze drying process may provide some insight into the mechanical properties of agarose-based chromatography media.

  1. A simple immunoblotting method after separation of proteins in agarose gel

    DEFF Research Database (Denmark)

    Koch, C; Skjødt, K; Laursen, I


    A simple and sensitive method for immunoblotting of proteins after separation in agarose gels is described. It involves transfer of proteins onto nitrocellulose paper simply by diffusion through pressure, a transfer which only takes about 10 min. By this method we have demonstrated the existence ...

  2. Impact of saccharides on the drying kinetics of agarose gels measured by in-situ interferometry (United States)

    Mao, Bosi; Divoux, Thibaut; Snabre, Patrick


    Agarose gels are viscoelastic soft solids that display a porous microstructure filled with water at 90% w/w or more. Despite an extensive use in food industry and microbiology, little is known about the drying kinetics of such squishy solids, which suffers from a lack of time-resolved local measurements. Moreover, only scattered empirical observations are available on the role of the gel composition on the drying kinetics. Here we study by in-situ interferometry the drying of agarose gels of various compositions cast in Petri dishes. The gel thinning is associated with the displacement of interference fringes that are analyzed using an efficient spatiotemporal filtering method, which allows us to assess local thinning rates as low as 10 nm/s with high accuracy. The gel thinning rate measured at the center of the dish appears as a robust observable to quantify the role of additives on the gel drying kinetics and compare the drying speed of agarose gels loaded with various non-gelling saccharides of increasing molecular weights. Our work shows that saccharides systematically decrease the agarose gel thinning rate up to a factor two, and exemplifies interferometry as a powerful tool to quantify the impact of additives on the drying kinetics of polymer gels. PMID:28112236

  3. Mold Simulator Study of the Initial Solidification of Molten Steel in Continuous Casting Mold: Part II. Effects of Mold Oscillation and Mold Level Fluctuation (United States)

    Zhang, Haihui; Wang, Wanlin


    The surface quality of the continuous casting strands is closely related to the initial solidification of liquid steel in the vicinity of the mold meniscus, and thus the clear understanding of the behavior of molten steel initial solidification would be of great importance for the control of the quality of final slab. With the development of the mold simulator techniques, the complex interrelationship between the solidified shell surface profile, heat flux, shell thickness, mold level fluctuation, and the infiltrated slag film was well illustrated in our previous study. As the second part, this article investigated the effect of the mold oscillation frequency, stroke, and mold level fluctuation on the initial solidification of the molten steel through the conduction of five different experiments. Results suggested that in the case of the stable mold level, the oscillation marks (OMs) exhibit equally spaced horizon depressions on the shell surface, where the heat flux at the meniscus area raises rapidly during negative strip time (NST) period and the presence of each OMs on the shell surface is corresponding to a peak value of the heat flux variation rate. Otherwise, the shell surface is poorly defined by the existence of wave-type defects, such as ripples or deep depressions, and the heat flux variation is irregular during NST period. The rising of the mold level leads to the longer-pitch and deeper OMs formation; conversely, the falling of mold level introduces shorter-pitch and shallower OMs. With the increase of the mold oscillation frequency, the average value of the low-frequency heat flux at the meniscus increases; however, it decreases when the mold oscillation stroke increases. Additionally, the variation amplitude of the high-frequency temperature and the high-frequency heat flux decreases with the increase of the oscillation frequency and the reduction of the oscillation stroke.

  4. Multiple depositions of Ag nanoparticles on chemically modified agarose films for surface-enhanced Raman spectroscopy (United States)

    Zhai, Wen-Lei; Li, Da-Wei; Qu, Lu-Lu; Fossey, John S.; Long, Yi-Tao


    A facile and cost-effective approach for the preparation of a surface-enhanced Raman spectroscopy (SERS) substrate through constructing silver nanoparticle/3-aminopropyltriethoxysilane/agarose films (Ag NPs/APTES/Agar film) on various solid supports is described. The SERS performance of the substrate was systematically investigated, revealing a maximum SERS intensity with four layers of the Ag NP deposition. The enhancement factor of the developed substrate was calculated as 1.5 × 107 using rhodamine 6G (R6G) as the probe molecule, and the reproducibility of the SERS signals was established. A high throughput screening platform was designed, manufactured and implemented which utilised the ability to cast agarose to assemble arrays. Quantitative analysis of 4-aminobenzoic acid (4-ABA) and 4-aminothiophenol (4-ATP) was achieved over a ~0.5 nM-0.1 μM range.A facile and cost-effective approach for the preparation of a surface-enhanced Raman spectroscopy (SERS) substrate through constructing silver nanoparticle/3-aminopropyltriethoxysilane/agarose films (Ag NPs/APTES/Agar film) on various solid supports is described. The SERS performance of the substrate was systematically investigated, revealing a maximum SERS intensity with four layers of the Ag NP deposition. The enhancement factor of the developed substrate was calculated as 1.5 × 107 using rhodamine 6G (R6G) as the probe molecule, and the reproducibility of the SERS signals was established. A high throughput screening platform was designed, manufactured and implemented which utilised the ability to cast agarose to assemble arrays. Quantitative analysis of 4-aminobenzoic acid (4-ABA) and 4-aminothiophenol (4-ATP) was achieved over a ~0.5 nM-0.1 μM range. Electronic supplementary information (ESI) available: the chemical structure of agarose, the SEM characterization of the synthesised Ag NPs, the calculation of the EF, the stability of the SERS substrate. See DOI: 10.1039/c1nr10956a

  5. Thermoplastic blow molding of metals

    Directory of Open Access Journals (Sweden)

    Jan Schroers


    Full Text Available While plastics have revolutionized industrial design due to their versatile processability, their relatively low strength has hampered their use in structural components. On the other hand, while metals are the basis for strong structural components, the geometries into which they can be processed are rather limited. The “ideal” material would offer a desirable combination of superior structural properties and the ability to be precision (net shaped into complex geometries. Here we show that bulk metallic glasses (BMGs, which have superior mechanical properties, can be blow molded like plastics. The key to the enhanced processability of BMG formers is their amenability to thermoplastic forming. This allows complex BMG structures, some of which cannot be produced using any other metal process, to be net shaped precisely.

  6. Challenges in mold manufacturing for high precision molded diffractive optical elements (United States)

    Pongs, Guido; Bresseler, Bernd; Schweizer, Klaus; Bergs, Thomas


    Isothermal precision glass molding of imaging optics is the key technology for mass production of precise optical elements. Especially for numerous consumer applications (e.g. digital cameras, smart phones, …), high precision glass molding is applied for the manufacturing of aspherical lenses. The usage of diffractive optical elements (DOEs) can help to further reduce the number of lenses in the optical systems which will lead to a reduced weight of hand-held optical devices. But today the application of molded glass DOEs is limited due to the technological challenges in structuring the mold surfaces. Depending on the application submicrometer structures are required on the mold surface. Furthermore these structures have to be replicated very precisely to the glass lens surface. Especially the micro structuring of hard and brittle mold materials such as Tungsten Carbide is very difficult and not established. Thus a multitude of innovative approaches using diffractive optical elements cannot be realized. Aixtooling has investigated in different mold materials and different suitable machining technologies for the micro- and sub-micrometer structuring of mold surfaces. The focus of the work lays on ultra-precision grinding to generate the diffractive pattern on the mold surfaces. This paper presents the latest achievements in diffractive structuring of Tungsten Carbide mold surfaces by ultra-precision grinding.

  7. Characterization of fiberglass-filled diallyl phthalate plastic molding resins and molded parts

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, R.B.; Glaub, J.E.; Bonekowski, N.R.; Gillham, P.D.


    Characterization of diallyl phthalate (DAP) molding resins was undertaken by differential scanning calorimetry (DSC) and by combined size exclusion chromatography (SEC)/low angle laser light scattering (LALLS) in order to better predict moldability and storage life limits. Completeness of cure of molded parts, before and after any post-curing, was also determined by thermal analysis. Molecular weights and molecular weight distributions of the DAP molding resins by SEC/LALLS indicated that the better molding resins have lower M/sub w//M/sub n/ ratios. Association effects were observed, which could not be overcome by solvent modification alone. Determination of DAP molding resin heats of reaction by DSC indicated a linear relation between R/ and weight percent filler for the good molding resins. DSC analyses of molded DAP parts showed that 95% cure was achieved in some as-molded parts, with a post-cure temperature of 165/sup 0/C being required to complete the cure to 100%. Thickness of the parts was a factor, with the thicker parts being 100% cured as molded. The glass transition temperature (T/sub g/) of the molded parts increased as cure was completed, to approx. 160 to 165/sup 0/C maximum. These results are consistent with a model of thermoset resin curing behavior which states that 100% cure can be achieved only if a post-curing operation is conducted above the T/sub g infinity/ (T/sub g/ at complete cure) of the polymer.

  8. Cooling simulation of plastic injection molding

    Institute of Scientific and Technical Information of China (English)


    Analyses the cooling of mold and plastic part during injectionmolding and the continued cooling of plastic part after being ejected from mold using the heat transfer theory and Boundary Element Method (BEM) to predict the temperature distribution in both mold and plastic part,and presents the experiments carried out with plates of ABS (Acrylonitrile-Butadiene-Styrene) to verify the validity of the cooling analysis software used to simulate the temperature distribution in ABS plate parts, and concludes that the analysis software agree qualitatively well with actual experimental findings.

  9. Fast prototyping of injection molded polymer microfluidic chips

    DEFF Research Database (Denmark)

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


    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...

  10. Evaluation of stability for monolayer injection molding tools coating

    DEFF Research Database (Denmark)

    Cech, Jiri; Taboryski, Rafael J.


    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...... and especially suitable for rapid prototyping and mold geometry testing....

  11. Solving depressions formed during production of plastic molding

    Directory of Open Access Journals (Sweden)

    J. Dobránsky


    Full Text Available This article deals with improvement of design properties of molded plastic parts. It can be achieved by modifying construction of metal injection mold and optimization of parameters in injection process. The subject of our examination was depressions formed on molded plastic parts which are inacceptable in the process of approval. The problem which has arisen was solved in two phases. The first phase consisted in alteration of injection mold design – enlargement of injection molding gate. In the second phase, we have changed the location of injection molding gate. After performing constructional modifications, new molded plastic parts were manufactured and assessed.

  12. A new insight into foaming mechanisms in injection molding via a novel visualization mold

    Directory of Open Access Journals (Sweden)

    V. Shaayegan


    Full Text Available The complex mechanisms of bubble nucleation and dynamics in foam injection molding have not been uncovered despite many previous efforts due to the non-steady stop-and-flow nature of injection molding and the non-uniform temperature and pressure distributions in the mold. To this end, a new visualization mold was designed and manufactured for the direct observation of bubble nucleation and growth/collapse in foam injection molding. A reflective prism was incorporated into the stationary part of the injection mold with which the nucleation and growth behaviors of bubbles were successfully observed. The mechanisms of bubble nucleation in low- and high-pressure foam injection molding, with and without the application of gas-counter pressure, was investigated. We identified how the inherently non-uniform cell structure is developed in low-pressure foam injection molding with gate-nucleated bubbles, and when and how cell nucleation occurs in high-pressure foam injection molding with a more uniform pressure drop.

  13. Custom molded thermal MRg-FUS phantom (United States)

    Eames, Matthew D. C.; Snell, John W.; Hananel, Arik; Kassell, Neal F.


    This article describes a method for creating custom-molded thermal phantoms for use with MR-guided focused ultrasound systems. The method is defined here for intracranial applications, though it may be modified for other anatomical targets.

  14. Rozen : steeds meer bekend over Black Mold

    NARCIS (Netherlands)

    Smits, A.P.; Kohrman, E.


    Onderzoek naar Black Mold heeft al veel informatie opgeleverd over de verspreiding, bestrijding en ontwikkeling van de oculatieschimmel. In dit artikel de nieuwste resultaten van PPO en Cultus Agro Advies

  15. Three-Dimensional Pneumatic Molding of Veneers

    Directory of Open Access Journals (Sweden)

    Milan Gaff


    Full Text Available The goal of this paper is to introduce a new testing method suitable for the evaluation of the three-dimensional (3-D moldability of veneers and to use this method to test the impact of specific factors on the 3-D pneumatic molding process. The tested factors included veneer moisture content, wood species, shape of test piece, and fixing method on the maximum wood deflection. Veneers were molded using compressed air on equipment designed by our group for the sole purpose of this experiment. The results indicated that the monitored factors had an effect on deflection during the 3-D molding process. The results of this investigation extend the state-of-the-art knowledge regarding this technology and indicate the possibility of utilizing this innovative testing method for 3-D molded veneers.

  16. Injection molded optical backplane for broadcast architecture (United States)

    Rosenberg, Paul; Mathai, Sagi; Sorin, Wayne V.; McLaren, Moray; Straznicky, Joseph; Panotopoulos, Georgios; Warren, David; Morris, Terry; Tan, Michael R. T.


    A low cost, blind mate, injection molded optical backplane is presented. The optical backplane is comprised of 12 channel optical broadcast buses, operating at 10Gbps/channel with six blindmate optical output ports spaced 1U apart.

  17. Molds on Food: Are They Dangerous? (United States)

    ... green dots on bread, white dust on Cheddar, coin-size velvety circles on fruits, and furry growth ... below the surface. Moldy foods may also have bacteria growing along with the mold. Hard salami and ...

  18. National Allergy Bureau Pollen and Mold Report (United States)

    ... the Expert Search Search AAAAI National Allergy Bureau Pollen and Mold Report Date: April 11, 2017 Location: ... 11, 2017 Click Here to View Most Recent Pollen and Spore Levels (04/10/2017) If you ...

  19. 21 CFR 133.184 - Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk. (United States)


    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk. 133.184 Section 133.184 Food and Drugs FOOD AND DRUG ADMINISTRATION..., sheep's milk blue-mold, and blue-mold cheese from sheep's milk. (a) Description. (1) Roquefort...

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

    Directory of Open Access Journals (Sweden)

    Li Yuanyuan


    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.

  1. Recovery of DNA from Agarose Gel with Home-made Silica Milk

    Institute of Scientific and Technical Information of China (English)


    An usefulness of silica milk made with waste ultraviolet light tube for recovery of DNA fragment from agarose gel was represented. The glass milk is a water suspension of 50% fine silica powder prepared by grinding the crushed waste ultraviolet light tube with a porcelain mortar.It was showed that one microliter of the glass milk could bind more than 1 μg of DNA fragment,and DNA fragment in length from 125 bp to 23 kb could be efficiently recovered from agarose gel. The bound DNA could be eluted from the particle of SiO2 in the glass milk with a yield of about 60%-80%.The eluted DNA could be used in all manipulations in molecular cloning.

  2. Preparation and structural characterization of O-acetyl agarose with low degree of substitution

    Directory of Open Access Journals (Sweden)

    Rosangela B. Garcia


    Full Text Available Among the biodegradable polymers, the polysaccharides have been found to be promising carriers for bioactive molecules. From a general standpoint, they present several reactive groups, such as hydroxyl, carboxyl and amine, that can be modified in a number of ways, giving rise to suitable devices for controlled release. In this paper, agarose was submitted to O-acetylation reactions under heterogeneous conditions, using acetic anhydride and pyridine, aiming to observe the effect of acetyl groups on the agarose properties. The products were characterized by Infrared and ¹H NMR spectroscopies. In the range of average acetylation degrees (DA 0.07-0.48, the polymers presented partial solubility in boiling water and in common organic solvents. The ¹H NMR spectra presented evidences of non-homogeneous acetyl group distribution along the chains, as concluded from the solubility of only one of the fractions with DA<0.09, in boiling water .

  3. Mapping Tax Compliance

    DEFF Research Database (Denmark)

    Boll, Karen


    Tax compliance denotes the act of reporting and paying taxes in accordance with the tax laws. Current social science scholarship on tax compliance can almost entirely be divided into behavioural psychology analyses and critical tax studies. This article, which presents two cases of how tax...

  4. Integrated mold/surface-micromachining process

    Energy Technology Data Exchange (ETDEWEB)

    Barron, C.C.; Fleming, J.G.; Montague, S.; Sniegowski, J.J.; Hetherington, D.L.


    We detail a new monolithically integrated silicon mold/surface-micromachining process which makes possible the fabrication of stiff, high-aspect-ratio micromachined structures integrated with finely detailed, compliant structures. An important example, which we use here as our process demonstration vehicle, is that of an accelerometer with a large proof mass and compliant suspension. The proof mass is formed by etching a mold into the silicon substrate, lining the mold with oxide, filling it with mechanical polysilicon, and then planarizing back to the level of the substrate. The resulting molded structure is recessed into the substrate, forming a planar surface ideal for subsequent processing. We then add surface-micromachined springs and sense contacts. The principal advantage of this new monolithically integrated mold/surface-micromachining process is that it decouples the design of the different sections of the device: In the case of a sensitive accelerometer, it allows us to optimize independently the proof mass, which needs to be as large, stiff, and heavy as possible, and the suspension, which needs to be as delicate and compliant as possible. The fact that the high-aspect-ratio section of the device is embedded in the substrate enables the monolithic integration of high-aspect-ratio parts with surface-micromachined mechanical parts, and, in the future, also electronics. We anticipate that such an integrated mold/surface micromachining/electronics process will offer versatile high-aspect-ratio micromachined structures that can be batch-fabricated and monolithically integrated into complex microelectromechanical systems.


    Directory of Open Access Journals (Sweden)

    Tomasz Garbacz


    Full Text Available In a study of cellular injection, molding process uses polyvinylchloride PVC. Polymers modified with introducing blowing agents into them in the Laboratory of the Department of Technologies and Materiase of Technical University of Kosice. For technological reasons, blowing agents have a form of granules. In the experiment, the content of the blowing agent (0–2,0 % by mass fed into the processed polymer was adopted as a variable factor. In the studies presented in the article, the chemical blowing agents occurring in the granulated form with a diameter of 1.2 to 1.4 mm were used. The view of the technological line for cellular injection molding and injection mold cavity with injection moldings are shown in Figure 1. The results of the determination of selected properties of injection molded parts for various polymeric materials, obtained with different content of blowing agents, are shown in Figures 4-7. Microscopic examination of cross-sectional structure of the moldings were obtained using the author's position image analysis of porous structure. Based on analysis of photographs taken (Figures 7, 8, 9 it was found that the coating containing 1.0% of blowing agents is a clearly visible solid outer layer and uniform distribution of pores and their sizes are similar.

  6. Hierarchically designed agarose and poly(ethylene glycol) interpenetrating network hydrogels for cartilage tissue engineering. (United States)

    DeKosky, Brandon J; Dormer, Nathan H; Ingavle, Ganesh C; Roatch, Christopher H; Lomakin, Joseph; Detamore, Michael S; Gehrke, Stevin H


    A new method for encapsulating cells in interpenetrating network (IPN) hydrogels of superior mechanical integrity was developed. In this study, two biocompatible materials-agarose and poly(ethylene glycol) (PEG) diacrylate-were combined to create a new IPN hydrogel with greatly enhanced mechanical performance. Unconfined compression of hydrogel samples revealed that the IPN displayed a fourfold increase in shear modulus relative to a pure PEG-diacrylate network (39.9 vs. 9.9 kPa) and a 4.9-fold increase relative to a pure agarose network (8.2 kPa). PEG and IPN compressive failure strains were found to be 71% ± 17% and 74% ± 17%, respectively, while pure agarose gels failed around 15% strain. Similar mechanical property improvements were seen when IPNs-encapsulated chondrocytes, and LIVE/DEAD cell viability assays demonstrated that cells survived the IPN encapsulation process. The majority of IPN-encapsulated chondrocytes remained viable 1 week postencapsulation, and chondrocytes exhibited glycosaminoglycan synthesis comparable to that of agarose-encapsulated chondrocytes at 3 weeks postencapsulation. The introduction of a new method for encapsulating cells in a hydrogel with enhanced mechanical performance is a promising step toward cartilage defect repair. This method can be applied to fabricate a broad variety of cell-based IPNs by varying monomers and polymers in type and concentration and by adding functional groups such as degradable sequences or cell adhesion groups. Further, this technology may be applicable in other cell-based applications where mechanical integrity of cell-containing hydrogels is of great importance.

  7. High Resolution Microsatellite Marker Analysis of Some Rice Landraces Using Metaphor Agarose Gel Electrophoresis


    K. Kristamtini; T. Taryono; Panjisakti Basunanda; Rudi Hari Murti


    Microsatellite markers or simple sequences repeats are DNA - based molecular techniques that are used to see the different among accessions and inbred lines. There are three methods to analysis the results of the polymerase chain reaction of microsatellite markers namely polyacrylamide gel electrophoresis (PAGE), capillary electroforesis, and Metaphor Agarose Gel Electroforesis (MAGE), and the Use of MAGE assessed more easily and economically the polymorphic pattern of DNA markers...

  8. Quantitation of Alkaline Phosphatase Isoenzymes Using Agarose Containing Wheat Germ Lectin (United States)


    Trizma (50 mmol)/barbital (14 mmol)/sodium barbital (50 mmol) buffer at pH 8.9 is available prepackaged from Sigma (710-1). Dissolve one 10 g vial in...materials. The separation of AP isoenzymes requires that the buffer pH be maintained at 8.9 +0.1. Electrophoresis 53 54 conducted using trizma ...21 Electrophoresis Buffer ........................... 21 AMP-Metal Ion Buffer ............................. 21 Agarose

  9. High throughput generation and trapping of individual agarose microgel using microfluidic approach

    KAUST Repository

    Shi, Yang


    Microgel is a kind of biocompatible polymeric material, which has been widely used as micro-carriers in materials synthesis, drug delivery and cell biology applications. However, high-throughput generation of individual microgel for on-site analysis in a microdevice still remains a challenge. Here, we presented a simple and stable droplet microfluidic system to realize high-throughput generation and trapping of individual agarose microgels based on the synergetic effect of surface tension and hydrodynamic forces in microchannels and used it for 3-D cell culture in real-time. The established system was mainly composed of droplet generators with flow focusing T-junction and a series of array individual trap structures. The whole process including the independent agarose microgel formation, immobilization in trapping array and gelation in situ via temperature cooling could be realized on the integrated microdevice completely. The performance of this system was demonstrated by successfully encapsulating and culturing adenoid cystic carcinoma (ACCM) cells in the gelated agarose microgels. This established approach is simple, easy to operate, which can not only generate the micro-carriers with different components in parallel, but also monitor the cell behavior in 3D matrix in real-time. It can also be extended for applications in the area of material synthesis and tissue engineering. © 2013 Springer-Verlag Berlin Heidelberg.

  10. Stability of beating frequency in cardiac myocytes by their community effect measured by agarose microchamber chip

    Directory of Open Access Journals (Sweden)

    Yasuda Kenji


    Full Text Available Abstract To understand the contribution of community effect on the stability of beating frequency in cardiac myocyte cell groups, the stepwise network formation of cells as the reconstructive approach using the on-chip agarose microchamber cell microcultivation system with photo-thermal etching method was applied. In the system, the shapes of agarose microstructures were changed step by step with photo-thermal etching of agarose-layer of the chip using a 1064-nm infrared focused laser beam to increase the interaction of cardiac myocyte cells during cultivation. First, individual rat cardiac myocyte in each microstructure were cultivated under isolated condition, and then connected them one by one through newly-created microchannels by photo-thermal etching to compare the contribution of community size for the magnitude of beating stability of the cell groups. Though the isolated individual cells have 50% fluctuation of beating frequency, their stability increased as the number of connected cells increased. And finally when the number reached to eight cells, they stabilized around the 10% fluctuation, which was the same magnitude of the tissue model cultivated on the dish. The result indicates the importance of the community size of cells to stabilize their performance for making cell-network model for using cells for monitoring their functions like the tissue model.

  11. A rapid sandwich immunoassay for human fetuin A using agarose-3-aminopropyltriethoxysilane modified microtiter plate. (United States)

    Vashist, Sandeep Kumar; Schneider, E Marion; Luong, John H T


    A rapid sandwich immunoassay (IA) with enhanced signal response for human fetuin A (HFA) was developed by modifying the surface of a KOH-treated polystyrene microtiter plate (MTP) with agarose and 3-aminopropyltriethoxysilane (APTES). The agarose-APTES complex binds covalently to the hydroxyl moiety of the MTP plate to serve as a binding platform for bioconjugation of EDC-activated anti-HFA antibody (Ab) via carbodiimide coupling. The one-step kinetics-based sandwich enzyme-linked immunosorbent assay (ELISA) enabled the detection of HFA in 30 min with a limit of detection (LOD) and a linear range of 0.02 ng mL(-1) and 1-243 ng mL(-1), respectively. It detected HFA spiked in diluted human whole blood and serum, and HFA in ethylenediaminetetraacetic acid (EDTA)-plasma of patients with high precision similar to that of conventional ELISA. The anti-HFA Ab-bound agarose-functionalized MTPs retained their functional activity after 6 weeks of storage in 0.1 M PBS, pH 7.4 at 4 °C.

  12. Method Development for Extraction of Butyrylcholin- esterase using Protein-G Agarose Spin Columns

    Directory of Open Access Journals (Sweden)

    Amruta S. Indapurkar


    Full Text Available Butyrylcholinesterase (BuChE is a biomarker of organophosphate (OP poisoning and can be used as a diagnostic marker to measure exposure to OP compounds. The purpose of this study was to develop a method to extract BuChE from human plasma. BuChE was extracted from plasma using the NAb protein-G Agarose Spin Kit. Factors affecting extraction like incubation time, plasma volume and cross-linking of antibodies to agarose beads were evaluated. All samples were analyzed for BuChE activity using the Ellman’s assay. The incubation times of plasma and anti-BuChE antibodies marginally affected the extraction efficiency of BuChE whereas a decrease in plasma volume increased the extraction efficiency. Cross-linking of anti-BuChE antibodies on agarose increased the extraction efficiency. The NAb protein-G Spin Kit can be used successfully to extract BuChE from human plasma. This extraction technique may be coupled to downstream analytical analyses for diagnosing exposure to OP compounds.

  13. Fenugreek hydrogel–agarose composite entrapped gold nanoparticles for acetylcholinesterase based biosensor for carbamates detection

    Energy Technology Data Exchange (ETDEWEB)

    Kestwal, Rakesh Mohan; Bagal-Kestwal, Dipali; Chiang, Been-Huang, E-mail:


    A biosensor was fabricated to detect pesticides in food samples. Acetylcholinesterase was immobilized in a novel fenugreek hydrogel–agarose matrix with gold nanoparticles. Transparent thin films with superior mechanical strength and stability were obtained with 2% fenugreek hydrogel and 2% agarose. Immobilization of acetylcholinesterase on the membrane resulted in high enzyme retention efficiency (92%) and a significantly prolonged shelf life of the enzyme (half-life, 55 days). Transmission electron microscopy revealed that, gold nanoparticles (10–20 nm in diameter) were uniformly dispersed in the fenugreek hydrogel–agarose–acetylcholinesterase membrane. This immobilized enzyme-gold nanoparticle dip-strip system detected various carbamates, including carbofuran, oxamyl, methomyl, and carbaryl, with limits of detection of 2, 21, 113, and 236 nM (S/N = 3), respectively. Furthermore, the fabricated biosensor exhibited good testing capabilities when used to detect carbamates added to various fruit and vegetable samples. - Highlights: • Acetylcholinesterase (AChE) dip-strip biosensor fabricated to detect carbamates. • AChE entrapped in fenugreek hydrogel–agarose matrix with gold nanoparticles (GNPs). • High enzyme retention efficiency (92%) and shelf life (half-life, 55 days). • Detection limits of carbofuran, oxamyl and methomyl: 2, 21 and 113 nM. • The biosensor had good testing capabilities to detect carbamates in food samples.

  14. Compliance and Enforcement Actions (CEA) - (United States)

    Department of Transportation — Compliance and Enforcement Actions application provides process assistance / improvements for conducting investigation and enforcement activities. The Compliance and...

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

    DEFF Research Database (Denmark)

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


    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...

  16. Development of sheet molding compound solar collectors with molded-in silvered glass reflective surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Champion, R. L.; Allred, R. E.


    The reflecting concentrator of a parabolic trough solar collector system comprises approximately 40% of initial system cost. The parabolic concentrator structure is also the most influential component in determining overall system efficiency. Parabolic test moldings have been fabricated from a general purpose sheet molding compound with flat chemically strengthened glass, flat annealed glass, and thermally formed glass. The test panel configuration was a 1.22 m x 0.61 m, 45/sup 0/ rim angle (0.762 m focal length) parabola. Attempts to mold with annealed sheet glass (1 mm thick) and thermally formed glass (1.25 mm thick) were unsuccessful; only the chemically strengthened glass (1.25 mm thick) was strong enough to survive molding pressures. Because of the mismatch in thermal expansion between glass and sheet molding compound, the as-molded panels contained a sizeable residual stress. The results are given of dimensional changes taking place in the panels under accelerated thermal cycling and outdoor aging conditions; these results are compared to an analytical model of the laminate. In addition, the sheet molding compound has been examined for thermomechanical properties and flow behavior in the rib sections. Results indicated that lowering the thermal expansion coefficient of the sheet molding compound through material modifications would produce a more stable structure.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Faiz, E-mail:; Aslam, Muhammad, E-mail:; Altaf, Khurram, E-mail:; Shirazi, Irfan, E-mail: [Mechanical Engineering Universiti Teknologi PETRONAS Malaysia (Malaysia)


    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.

  18. Study On The External Gas-Assisted Mold Temperature Control For Thin Wall Injection Molding

    Directory of Open Access Journals (Sweden)

    ThanhTrung Do


    Full Text Available Dynamic mold surface temperature control (DMTC has many advantages in micro-injection molding as well as thin-wall molding product. In this paper, DMTC will be applied for the thin-wall molding part with the observation of the weldline appearance and the weldline strength. The heating step of DMTC will be achieved by the hot air flow directly to the weldline area. The results show that the heating rate could be reached to 4.5C/s, which could raising the mold surface from 30C to over 120C within 15 s. The melt filling was operated with high temperature at the weldline area; therefore, the weldline appearance was eliminated. In addition, the weldline strength was also improved. The results show that the thinner part had the higher strength of the weldline

  19. 40 CFR 63.7734 - How do I demonstrate initial compliance with the emissions limitations that apply to me? (United States)


    ... used to demonstrate compliance. (1) For each electric arc metal melting furnace, electric induction... cupola metal melting furnace or electric arc metal melting furnace at a new iron and steel foundry, (i... each TEA cold box mold or core making line in a new or existing iron and steel foundry, the average...

  20. Injection molding simulation with variothermal mold temperature control of highly filled polyphenylene sulfide (United States)

    Birkholz, A.; Tschiersky, M.; Wortberg, J.


    For the installation of a fuel cell stack to convert chemical energy into electricity it is common to apply bipolar plates to separate and distribute reaction gases and cooling agents. For reducing manufacturing costs of bipolar plates a fully automated injection molding process is examined. The high performance thermoplastic matrix material, polyphenylene sulfide (PPS), defies against the chemical setting and the operation temperature up to 200 °C. To adjust also high electrical and thermal conductivity, PPS is highly filled with various carbon fillers up to an amount of 65 percentage by volume. In the first step two different structural plates (one-sided) with three different gate heights and molds are designed according to the characteristics of a bipolar plate. To cope with the approach that this plate should be producible on standard injection molding machines with variothermal mold temperature control, injection molding simulation is used. Additionally, the simulation should allow to formulate a quality prediction model, which is transferrable to bipolar plates. Obviously, the basis for a precise simulation output is an accurate description of the material properties and behavior of the highly filled compound. This, the design of the structural plate and mold and the optimization via simulation is presented, as well. The influence of the injection molding process parameters, e.g. injection time, cycle times, packing pressure, mold temperature, and melt temperature on the form filling have been simulated to determine optimal process conditions. With the aid of the simulation and the variothermal mold temperature control it was possible to reduce the required melt temperature below the decomposition temperature of PPS. Thereby, hazardous decomposition products as hydrogen sulfide are obviated. Thus, the health of the processor, the longevity of the injection molding machine as well as the material and product properties can be protected.

  1. Environmental impact estimation of mold making process (United States)

    Kong, Daeyoung

    Increasing concern of environmental sustainability regarding depletion of natural resources and resulting negative environmental impact has triggered various movements to address these issues. Various regulations about product life cycle have been made and applied to industries. As a result, how to evaluate the environmental impact and how to improve current technologies has become an important issue to product developers. Molds and dies are very generally used manufacturing tools and indispensible parts to the production of many products. However, evaluating environmental impact in mold and die manufacturing is not well understood and not much accepted yet. The objective of this thesis is to provide an effective and straightforward way of environmental analysis for mold and die manufacturing practice. For this, current limitations of existing tools were identified. While conventional life cycle assessment tools provide a lot of life cycle inventories, reliable data is not sufficient for the mold and die manufacturer. Even with comprehensive data input, current LCA tools only provide another comprehensive result which is not directly applicable to problem solving. These issues are critical especially to the mold and die manufacturer with limited resource and time. This thesis addresses the issues based on understanding the needs of mold and die manufacturers. Computer aided manufacturing (CAM) is the most frequently used software tool and includes most manufacturing information including the process definition and sometimes geometric modeling. Another important usage of CAM software tools is problem identification by process simulation. Under the virtual environment, possible problems are detected and solved. Environmental impact can be handled in the same manner. To manufacture molds and dies with minimizing the associated environmental impact, possible environmental impact sources must be minimized before the execution in the virtual environment. Molds and dies

  2. Agarose gels (United States)


    Discovered in 17th-century Japan, agar is a jelly-like substance obtained by boiling algae, and it is widely used as a gelling agent for desserts in Japanese, Indian, Philippine and Vietnamese cuisine.

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

    DEFF Research Database (Denmark)

    Cech, Jiri; Taboryski, Rafael J.


    The injection molding industry often employs prototype molds and mold inserts from melt spun (rapid solidification processing [1,2]) aluminum, especially for applications in optics [3,4], photonics [5] and microfludics. Prototypes are also used for verification of mold filling. The use of aluminum...... tools has reduced lead time (days instead of weeks) and manufacturing cost (30% of conventional mold). Moreover, for aluminum, a surface roughness (RMS) below 5 nm can be obtained with diamond machining [3,4,6]. Conventional mold coatings add cost and complexity, and coatings with thicknesses of a few...

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

    DEFF Research Database (Denmark)

    Matschuk, Maria; Larsen, Niels B


    with FDTS. Reduced adhesion forces are consistent with lowered friction that reduces the risk of fracturing the nanoscopic pillars during demolding. Optimized mold surface chemistry and associated injection molding conditions permitted the fabrication of square arrays of 40 nm wide and 107 nm high (aspect......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...

  5. Environmental Compliance Guide

    Energy Technology Data Exchange (ETDEWEB)



    The Guide is intended to assist Department of Energy personnel by providing information on the NEPA process, the processes of other environmental statutes that bear on the NEPA process, the timing relationships between the NEPA process and these other processes, as well as timing relationships between the NEPA process and the development process for policies, programs, and projects. This information should be helpful not only in formulating environmental compliance plans but also in achieving compliance with NEPA and various other environmental statutes. The Guide is divided into three parts with related appendices: Part I provides guidance for developing environmental compliance plans for DOE actions; Part II is devoted to NEPA with detailed flowcharts depicting the compliance procedures required by CEQ regulations and Department of Energy NEPA Guidelines; and Part III contains a series of flowcharts for other Federal environmental requirements that may apply to DOE projects.

  6. Compliance for Green IT

    CERN Document Server

    Calder, Alan


    The growing range of Green IT regulations are challenging more and more organisations to take specific steps to ensure they are in compliance with sometimes complex regulations, ranging from cap & trade requirements through to regulations concerning IT equipment disposal.

  7. Gating of Permanent Molds for Aluminum Casting

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang


    This report summarizes a two-year project, DE-FC07-011D13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was to determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings. Equipment and procedure for real time X-Ray radiography of molten aluminum flow into permanent molds have been developed. Other studies have been conducted using water flow and behavior of liquid aluminum in sand mold using real time photography. This investigation utilizes graphite molds transparent to X-Rays making it possible to observe the flow pattern through a number of vertically oriented grating systems. These have included systems that are choked at the base of a rounded vertical sprue and vertical gating systems with a variety of different ingates into the bottom of a mold cavity. These systems have also been changed to include gating systems with vertical and horizontal gate configurations. Several conclusions can be derived from this study. A sprue-well, as designed in these experiments, does not eliminate the vena contracta. Because of the swirling at the sprue-base, the circulating metal begins to push the entering metal stream toward the open runner mitigating the intended effect of the sprue-well. Improved designs of

  8. Modelling and monitoring in injection molding

    DEFF Research Database (Denmark)

    Thyregod, Peter


    -conforning unit is only expected very rarely during sampling, a moving sum chart and a CUSUM chart are equivalent. Finally, the correlation structure of 21 process variables has been studied prior to monitoring the process. Is is illustrated how the process can be analysed with multivariate techniques......This thesis is concerned with the application of statistical methods in quality improvement of injection molded parts. The methods described are illustrated with data from the manufacturing of parts for a medical device. The emphasis has been on the variation between cavities in multi-cavity molds...... taken within the same machine set-point did not cause great variation compared to the two preceding sources of variation. A simple graphical approach is suggested for finding patterns in the cavity differences. Applying this method to data from a 16 cavity mold, a clear connection was found between...

  9. Double blind placebo controlled exposure to molds

    DEFF Research Database (Denmark)

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


    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....... 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...... to placebo in eight sensitive school employees. However, a statistical type II error cannot be excluded because of the small sample size. PRACTICAL IMPLICATIONS: In this double blind, placebo controlled study of mold exposure changes in symptoms, objective measurements and blood samples were small and mostly...

  10. 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...

  11. Single gate optimization for plastic injection mold

    Institute of Scientific and Technical Information of China (English)

    LI Ji-quan; LI De-qun; GUO Zhi-ying; LV Hai-yuan


    This paper deals with a methodology for single gate location optimization for plastic injection mold. The objective of the gate optimization is to minimize the warpage of injection molded parts, because warpage is a crucial quality issue for most injection molded parts while it is influenced greatly by the gate location. Feature warpage is defined as the ratio of maximum displacement on the feature surface to the projected length of the feature surface to describe part warpage. The optimization is combined with the numerical simulation technology to find the optimal gate location, in which the simulated annealing algorithm is used to search for the optimum. Finally, an example is discussed in the paper and it can be concluded that the proposed method is effective.

  12. High rate fabrication of compression molded components

    Energy Technology Data Exchange (ETDEWEB)

    Matsen, Marc R.; Negley, Mark A.; Dykstra, William C.; Smith, Glen L.; Miller, Robert J.


    A method for fabricating a thermoplastic composite component comprises inductively heating a thermoplastic pre-form with a first induction coil by inducing current to flow in susceptor wires disposed throughout the pre-form, inductively heating smart susceptors in a molding tool to a leveling temperature with a second induction coil by applying a high-strength magnetic field having a magnetic flux that passes through surfaces of the smart susceptors, shaping the magnetic flux that passes through surfaces of the smart susceptors to flow substantially parallel to a molding surface of the smart susceptors, placing the heated pre-form between the heated smart susceptors; and applying molding pressure to the pre-form to form the composite component.

  13. Neonatal Ear Molding: Timing and Technique. (United States)

    Anstadt, Erin Elizabeth; Johns, Dana Nicole; Kwok, Alvin Chi-Ming; Siddiqi, Faizi; Gociman, Barbu


    The incidence of auricular deformities is believed to be ∼11.5 per 10,000 births, excluding children with microtia. Although not life-threatening, auricular deformities can cause undue distress for patients and their families. Although surgical procedures have traditionally been used to reconstruct congenital auricular deformities, ear molding has been gaining acceptance as an efficacious, noninvasive alternative for the treatment of newborns with ear deformations. We present the successful correction of bilateral Stahl's ear deformity in a newborn through a straightforward, nonsurgical method implemented on the first day of life. The aim of this report is to make pediatric practitioners aware of an effective and simple molding technique appropriate for correction of congenital auricular anomalies. In addition, it stresses the importance of very early initiation of ear cartilage molding for achieving the desired outcome.

  14. Ultrasonically-assisted Polymer Molding: An Evaluation (United States)

    Moles, Matthew; Roy, Anish; Silberschmidt, Vadim

    Energy reduction in extrusion and injection molding processes can be achieved by the introduction of ultrasonic energy. Polymer flow can be enhanced on application of ultrasonic vibration, which can reduce the thermal and pressure input requirements to produce the same molding; higher productivity may also be achieved. In this paper, a design of an ultrasound-assisted injection mold machine is explored. An extrusion-die design was augmented with a commercial 1.5 kW ultrasonic transducer and sonotrode designed to resonate close to 20 kHz with up to 100 μm vibration amplitude. The design was evaluated with modal and thermal analysis using finite-element analysis software. The use of numerical techniques, including computational fluid dynamics, fluid-structure interaction and coupled Lagrangian-Eulerian method, to predict the effect of ultrasound on polymer flow was considered. A sonotrode design utilizing ceramic to enhance thermal isolation was also explored.

  15. The Elastic Mold Deformation During the Filling and Packing Stage of the Injection Molding Process

    Directory of Open Access Journals (Sweden)

    Stefan Kleindel


    Full Text Available The accurate numerical prediction of the mold filling process of long and thin walled parts is dependent on numerous factors. This paper investigates the effect of various influencing variables on the filling pattern by means of simulation and experimental validation. It was found that mold temperature, process settings and venting conditions have little effect on the predicted filling pattern. However, in the actual case study, the filling behavior observed during the experiments was significantly different compared to the numerical prediction. A structural finite element analysis of the moving mold half showed an unacceptable large deformation of the mold plates under injection pressure. A very good correlation between simulation and experiment was attained after improving the stiffness of the mold. Therefore it can be concluded, that the elasticity of the mold may have a significant influence on the filling pattern when long and thin walled products are considered. Furthermore, it was shown, that even an apparently stiff mold can exhibit a distinct deformation during filling and packing stage.

  16. Mold Simulator Study of Heat Transfer Phenomenon During the Initial Solidification in Continuous Casting Mold (United States)

    Zhang, Haihui; Wang, Wanlin


    In this paper, mold simulator trials were firstly carried out to study the phenomena of the initial shell solidification of molten steel and the heat transfer across the initial shell to the infiltrated mold/shell slag film and mold. Second, a one-dimensional inverse heat transfer problem for solidification (1DITPS) was built to determine the temperature distribution and the heat transfer behavior through the solidifying shell from the measured shell thickness. Third, the mold wall temperature field was recovered by a 2DIHCP mathematical model from the measured in-mold wall temperatures. Finally, coupled with the measured slag film thickness and the calculations of 1DITPS and 2DIHCP, the thermal resistance and the thickness of liquid slag film in the vicinity of the meniscus were evaluated. The experiment results show that: the total mold/shell thermal resistance, the mold/slag interfacial thermal resistance, the liquid film thermal resistance, and the solid film thermal resistance is 8.0 to 14.9 × 10-4, 2.7 to 4.8 × 10-4, 1.5 to 4.6 × 10-4, and 3.9 to 6.8 × 10-4 m2 K/W, respectively. The percentage of mold/slag interfacial thermal resistance, liquid film thermal resistance, and solid film thermal resistance over the total mold/shell thermal resistance is 27.5 to 34.4, 17.2 to 34.0, and 38.5 to 48.8 pct, respectively. The ratio of radiation heat flux is around 14.1 to 51.9 pct in the liquid slag film.

  17. Acoustic transfer of protein crystals from agarose pedestals to micromeshes for high-throughput screening

    Energy Technology Data Exchange (ETDEWEB)

    Cuttitta, Christina M. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); The City University of New York, 2800 Victory Boulevard, Staten Island, NY 10314 (United States); Ericson, Daniel L. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); University at Buffalo, SUNY, 12 Capen Hall, Buffalo, NY 14260 (United States); Scalia, Alexander [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Binghamton University, 4400 Vestal Parkway East, Binghamton, NY 11973-5000 (United States); Roessler, Christian G. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Teplitsky, Ella [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Stony Brook University, Stony Brook, NY 11794-5215 (United States); Joshi, Karan [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); PEC University of Technology, Chandigarh (India); Campos, Olven [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33414 (United States); Agarwal, Rakhi; Allaire, Marc [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Orville, Allen M. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Sweet, Robert M.; Soares, Alexei S., E-mail: [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)


    An acoustic high-throughput screening method is described for harvesting protein crystals and combining the protein crystals with chemicals such as a fragment library. Acoustic droplet ejection (ADE) is an emerging technology with broad applications in serial crystallography such as growing, improving and manipulating protein crystals. One application of this technology is to gently transfer crystals onto MiTeGen micromeshes with minimal solvent. Once mounted on a micromesh, each crystal can be combined with different chemicals such as crystal-improving additives or a fragment library. Acoustic crystal mounting is fast (2.33 transfers s{sup −1}) and all transfers occur in a sealed environment that is in vapor equilibrium with the mother liquor. Here, a system is presented to retain crystals near the ejection point and away from the inaccessible dead volume at the bottom of the well by placing the crystals on a concave agarose pedestal (CAP) with the same chemical composition as the crystal mother liquor. The bowl-shaped CAP is impenetrable to crystals. Consequently, gravity will gently move the crystals into the optimal location for acoustic ejection. It is demonstrated that an agarose pedestal of this type is compatible with most commercially available crystallization conditions and that protein crystals are readily transferred from the agarose pedestal onto micromeshes with no loss in diffraction quality. It is also shown that crystals can be grown directly on CAPs, which avoids the need to transfer the crystals from the hanging drop to a CAP. This technology has been used to combine thermolysin and lysozyme crystals with an assortment of anomalously scattering heavy atoms. The results point towards a fast nanolitre method for crystal mounting and high-throughput screening.

  18. Acoustic transfer of protein crystals from agarose pedestals to micromeshes for high-throughput screening. (United States)

    Cuttitta, Christina M; Ericson, Daniel L; Scalia, Alexander; Roessler, Christian G; Teplitsky, Ella; Joshi, Karan; Campos, Olven; Agarwal, Rakhi; Allaire, Marc; Orville, Allen M; Sweet, Robert M; Soares, Alexei S


    Acoustic droplet ejection (ADE) is an emerging technology with broad applications in serial crystallography such as growing, improving and manipulating protein crystals. One application of this technology is to gently transfer crystals onto MiTeGen micromeshes with minimal solvent. Once mounted on a micromesh, each crystal can be combined with different chemicals such as crystal-improving additives or a fragment library. Acoustic crystal mounting is fast (2.33 transfers s(-1)) and all transfers occur in a sealed environment that is in vapor equilibrium with the mother liquor. Here, a system is presented to retain crystals near the ejection point and away from the inaccessible dead volume at the bottom of the well by placing the crystals on a concave agarose pedestal (CAP) with the same chemical composition as the crystal mother liquor. The bowl-shaped CAP is impenetrable to crystals. Consequently, gravity will gently move the crystals into the optimal location for acoustic ejection. It is demonstrated that an agarose pedestal of this type is compatible with most commercially available crystallization conditions and that protein crystals are readily transferred from the agarose pedestal onto micromeshes with no loss in diffraction quality. It is also shown that crystals can be grown directly on CAPs, which avoids the need to transfer the crystals from the hanging drop to a CAP. This technology has been used to combine thermolysin and lysozyme crystals with an assortment of anomalously scattering heavy atoms. The results point towards a fast nanolitre method for crystal mounting and high-throughput screening.

  19. Generation of Multicellular Tumor Spheroids with Microwell-Based Agarose Scaffolds for Drug Testing.

    Directory of Open Access Journals (Sweden)

    Xue Gong

    Full Text Available Three dimensional multicellular aggregate, also referred to as cell spheroid or microtissue, is an indispensable tool for in vitro evaluating antitumor activity and drug efficacy. Compared with classical cellular monolayer, multicellular tumor spheroid (MCTS offers a more rational platform to predict in vivo drug efficacy and toxicity. Nevertheless, traditional processing methods such as plastic dish culture with nonadhesive surfaces are regularly time-consuming, laborious and difficult to provide uniform-sized spheroids, thus causing poor reproducibility of experimental data and impeding high-throughput drug screening. In order to provide a robust and effective platform for in vitro drug evaluation, we present an agarose scaffold prepared with the template containing uniform-sized micro-wells in commercially available cell culture plates. The agarose scaffold allows for good adjustment of MCTS size and large-scale production of MCTS. Transparent agarose scaffold also allows for monitoring of spheroid formation under an optical microscopy. The formation of MCTS from MCF-7 cells was prepared using different-size-well templates and systematically investigated in terms of spheroid growth curve, circularity, and cell viability. The doxorubicin cytotoxicity against MCF-7 spheroid and MCF-7 monolayer cells was compared. The drug penetration behavior, cell cycle distribution, cell apoptosis, and gene expression were also evaluated in MCF-7 spheroid. The findings of this study indicate that, compared with cellular monolayer, MCTS provides a valuable platform for the assessment of therapeutic candidates in an in vivo-mimic microenvironment, and thus has great potential for use in drug discovery and tumor biology research.

  20. Natural latex (Hevea brasiliensis) mold for neovaginoplasty



    OBJETIVO: avaliar a utilização do molde de látex natural (Hevea brasiliensis) como modificação à neovaginoplastia de McIndoe e Bannister em pacientes portadoras da síndrome de Mayer-Rokitansky-Küster-Hauser (MRKH). MÉTODOS: análise retrospectiva de nove pacientes com o diagnóstico de síndrome de MRKH, submetidas à neovaginoplastia pela técnica de McIndoe e Bannister com molde de látex natural. Foram avaliadas epitelização, amplitude e profundidade das neovaginas, ocorrência de coitos bem como...

  1. Powder injection molding of pure titanium

    Institute of Scientific and Technical Information of China (English)

    GUO Shibo; DUAN Bohua; HE Xinbo; QU Xuanhui


    An improved wax-based binder was developed for powder injection molding of pure titanium. A critical powder loading of 69 vol.% and a pseudo-plastic flow behavior were obtained by the feedstock based on the binder. The injection molding, debinding, and sintering process were studied. An ideal control of carbon and oxygen contents was achieved by thermal debinding in vacuum atmosphere (10-3 Pa). The mechanical properties of as-sintered specimens were less than those of titanium made by the conventional press-sintering process. Good shape retention and ±0.04 mm dimension deviation were achieved.

  2. Streptavidin Capture and Detection Using Individual Agarose Bead-based Microfluidic Immunoassay Devices

    Institute of Scientific and Technical Information of China (English)

    Xiaoguang Du


    @@ A single microwell on polycarbonate substratc was fabricated using hot embossing by silicon master.The silicon master (85 μm in top,100 μm in bottom,53 μm in height) and 0.25 mm-thick polycarbonate substrate were sandwiched between two glass plates in hot embossing system.The system was heated to 155-160℃ and pressed with a force of 300 psi for 10-30 s.The single microwell was stampted on polycarbonate substrate.Apply a~0.2 μL aliquot of agarose beads to the single microwell.

  3. The preparation of low electroendosmosis agarose and its physico-chemical property

    Institute of Scientific and Technical Information of China (English)


    Studies on Gelidium amansii agar fractionations were carried out in this paper. Gelidium amansii agar was fractionated on DEAE-Cellulose, and four fractions were obtained sequentially. The fractions were analyzed on physical and chemical properties, and IR and 13C-NMR spectroscopy applied for elucidating the chemical structure. Among the four fractions obtained, water fraction measured up to the standard of low EEO agarose. The sulfate content, ash content, electroendosmosis and gel strength(1%) of water fraction were 0.16%, 0.34%, 0.12 and 1 130g/cm2 respectively, similar to those of the Sigma products.

  4. Agarose gel investigation of quantum dots conjugated with short ssDNA. (United States)

    Wu, Tsai-Chin; Dutta, Mitra; Stroscio, Michael A


    Herein, we investigate the migration distance of quantum-dot-functionalized complexes in electrophoresis. The quantitative study of these moving particles in an electrophoretic environment is modeled using an extended Smoluchowski equation. An extended Smoluchowski equation is proposed to addressed the D(m) to Ln(N) plot slope variation issue present in previous work and agreement between experiment and theory is found. The procedures underlying this work then discusses the potential of using agarose electrophoresis as a mean of monitoring the composition of nano-complexes consisting of quantum dots functionalized with differing numbers of DNA molecules.

  5. Characterization of agarose as immobilization matrix model for a microbial biosensor

    Directory of Open Access Journals (Sweden)

    Pernetti Mimma


    Full Text Available Microbial biosensors are promising tools for the detection of specific substances in different fields, such as environmental, biomedical, food or agricultural. They allow rapid measurements, no need for complex sample preparation or specialized personnel and easy handling. In order to enhance the managing, miniaturization and stability of the biosensor and to prevent cell leaching, bacteria immobilization is desirable. A systematic characterization procedure to choose a suitable immobilization method and matrix, was proposed in this study. Physical properties, storage stability mass transport phenomena and biocompatibility were evaluated, employing agarose as the model matrix. Preliminary essays with bioluminescent bacteria detecting Tributyltin were also carried out.

  6. Relationship Between Casting Distortion, Mold Filling, and Interfacial Heat Transfer in Sand Molds

    Energy Technology Data Exchange (ETDEWEB)

    J. K. Parker; K. A. Woodbury; T. S. Piwonka; Y. Owusu


    This project sought to determine the relationship between casting dimensions and interfacial heat transfer in aluminum alloy sand castings. The program had four parts; measurement of interfacial heat transfer coefficients in resin bonded and green sand molds, the measurement of gap formation in these molds, the analysis of castings made in varying gatings, orientations and thicknesses, and the measurement of residual stresses in castings in the as-cast and gate removed condition. New values for interfacial heat transfer coefficients were measured, a novel method for gap formation was developed, and the variation of casting dimensions with casting method, gating, and casting orientation in the mold was documented.

  7. Reduction of Injection Pressure for Thin Walled Molding using the Laser Metal Sintered Mold


    米山, 猛; 内藤, 圭亮; 阿部, 諭; 宮丸, 充


    Using milling combined laser metal sintering, porous surface has been fabricated on the thin walled cavity closed by the surrounded thick cavity in the injection mold. Resin flows into the cavity of 2mm thick at first around the thin part and then flows into the thin cavity of 0.2mm thick with 11mm square by packing pressure. The packing pressure for filling the thin part was compared among laser metal sintered mold with or without porous surface, steel mold with or without porous block. The ...

  8. Tool steel quality and surface finishing of plastic molds

    Directory of Open Access Journals (Sweden)

    Rafael Agnelli Mesquita


    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. Affordable, Precision Reflector Mold Technology (PDRT08-029) Project (United States)

    National Aeronautics and Space Administration — Advances in replication mold technology that reduce material costs, grinding time, and polishing time would enable fabrication of large, precision molds and possibly...

  10. Enhancing dry adhesives and replica molding with ethyl cyano-acrylate (United States)

    Bovero, E.; Menon, C.


    The use of cyano-acrylate to improve the performance of dry adhesives and their method of fabrication is investigated. Specifically, the contributions of this work are: (1) a new adhesion method to adhere to a large variety of surfaces, (2) a strategy to increase the compliance of dry adhesives, and (3) an improved fabrication process for micro-structured dry adhesives based on replica molding. For the first contribution, the adhesion method consists of anchoring a micro-structured dry adhesive to a surface through a layer of hardened ethyl cyano-acrylate (ECA). This method increases the adhesion of the orders of magnitude at the expense of leaving residue after detachment. However, this method preserves reusability. For the second contribution, a double-sided dry adhesive is obtained by introducing a substrate with a millimeter-sized pillar structure, which enabled further increasing adhesion. For the third contribution, an ECA layer is used as a mold for the fabrication of new adhesives. These new types of molds proved able to produce dry adhesives with high reproducibility and low degradation.

  11. Exploring the problem of mold growth and the efficacy of various mold inhibitor methods during moisture sorption isotherm measurements. (United States)

    Yu, X; Martin, S E; Schmidt, S J


    Mold growth is a common problem during the equilibration of food materials at high relative humidity values using the standard saturated salt slurry method. Exposing samples to toluene vapor and mixing samples with mold inhibitor chemicals are suggested methods for preventing mold growth while obtaining isotherms. However, no published research was found that examined the effect of mold growth on isotherm performance or the efficacy of various mold inhibitor methods, including their possible effect on the physicochemical properties of food materials. Therefore, the objectives of this study were to (1) explore the effect of mold growth on isotherm performance in a range of food materials, (2) investigate the effectiveness of 4 mold inhibitor methods, irradiation, 2 chemical inhibitors (potassium sorbate and sodium acetate), and toluene vapor, on mold growth on dent corn starch inoculated with A. niger, and (3) examine the effect of mold inhibitor methods on the physicochemical properties of dent corn starch, including isotherm performance, pasting properties, gelatinization temperature, and enthalpy. Mold growth was found to affect starch isotherm performance by contributing to weight changes during sample equilibration. Among the 4 mold inhibitor methods tested, irradiation and toluene vapor were found to be the most effective for inhibiting growth of A. niger on dent cornstarch. However, both methods exhibited a significant impact on the starches' physiochemical properties, suggesting the need to probe the efficacy of other mold inhibitor methods and explore the use of new rapid isotherm instruments, which hamper mold growth by significantly decreasing measurement time.

  12. 240 Mold Sensitization in Chronic Rhinosinusitis Patients



    Background It is estimated that about 10% of the population have IgE antibodies to common inhalant molds. Exposure to fungal allergens could be linked to the presence and persistence of asthma, rhinitis and atopic dermatitis. Mold sensitization is a risk factor for development and deterioration of upper airway allergy, especially chronic rhinosinusitis. We addressed the incidence of mold allergy measured as specific IgE to molds and skin prick tests in chronic sinusitis patients. We assessed ...


    Directory of Open Access Journals (Sweden)



    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.

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

    DEFF Research Database (Denmark)

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


    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, ...

  15. 21 CFR 874.3430 - Middle ear mold. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Middle ear mold. 874.3430 Section 874.3430 Food... DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3430 Middle ear mold. (a) Identification. A middle ear mold is a preformed device that is intended to be implanted to reconstruct the middle...

  16. Tailor-made cell patterning using a near-infrared-responsive composite gel composed of agarose and carbon nanotubes. (United States)

    Koga, Haruka; Sada, Takao; Fujigaya, Tsuyohiko; Nakashima, Naotoshi; Nakazawa, Kohji


    Micropatterning is useful for regulating culture environments. We developed a highly efficient near-infrared-(NIR)-responsive gel and established a new technique that enables cell patterning by NIR irradiation. As a new culture substratum, we designed a tissue culture plate that was coated with a composite gel composed of agarose and carbon nanotubes (CNTs). A culture plate coated with agarose only showed no response to NIR irradiation. In contrast, NIR laser irradiation induced heat generation by CNTs; this permitted local solation of the CNT/agarose gel, and consequently, selective cell-adhesive regions were exposed on the tissue culture plate. The solation area was controlled by the NIR intensity, magnification of the object lens and CNT concentration in the gel. Furthermore, we formed circular patterns of HeLa cells and linear patterns of 3T3 cells on the same culture plate through selective and stepwise NIR irradiation of the CNT/agarose gel, and we also demonstrated that individual 3T3 cells migrated along a linear path formed on the CNT/agarose gel by NIR irradiation. These results indicate that our technique is useful for tailor-made cell patterning of stepwise and/or complex cell patterns, which has various biological applications such as stepwise co-culture and the study of cell migration.

  17. Poly-lactic acid and agarose gelatin play an active role in the recovery of spinal cord injury

    Institute of Scientific and Technical Information of China (English)


    Objective To investigate the role of poly-lactic acid and agarose gelatin in promoting the functional recovery of the injured spinal cord. Methods Poly-lactic acid (PLA) or agarose was embedded in the space between two stumps of the hemisectioned spinal cord. Immunohistochemistry was used to show astroglia proliferation and the infiltration of RhoA-positive cells. Locomotor activity recovery was evaluated by testing the function of hindlimbs. Results Astroglias and RhoA labeled non-neuronal cells accumulated in the area adjacent to the implant, while the number of RhoA-positive cells was decreased dramatically in the absence of implant. Animals implanted with agarose gelatin recovered more quickly than those with PLA, concomitant with a higher survival rate of the neurons. Conclusion Both PLA and agarose gelatin benefited the recovery of spinal cord after injury by providing a scaffold for astroglia processes. Modulation of the rigidity, pore size and inner structure of PLA and agarose gelatin might make these biodegradable materials more effective in the regeneration of the central nervous system (CNS).

  18. Utilization of an Ionic Liquid/Urea Mixture as a Physical Coupling Agent for Agarose/Talc Composite Films

    Directory of Open Access Journals (Sweden)

    Rusli Daik


    Full Text Available An ionic liquid, 1-n-butyl-3-methylimidazolium chloride (BmimCl was blended with urea at 1:1 mole ratio to create a BmimCl/Urea mixture. The agarose/talc composite films containing the BmimCl/Urea mixture were then acquired through a gelation method. The weight ratio of agarose and talc was fixed at 4:1, while the content of BmimCl/Urea was varied from 0 to 10 wt % relative to the overall weight of the composite films. The tensile stress and modulus results showed the optimum BmimCl/Urea content in the composite film lies at 8 wt %. The talc particles are embedded in the agarose matrix and there are no pullouts for the composite films containing BmimCl/Urea as demonstrated by SEM micrographs. The addition of BmimCl/Urea increased the glass transition temperature of the composite films, however, the thermal decomposition temperature decreased drastically. FTIR and FT-Raman spectra indicated the existence of interaction between agarose and talc, which improves their interfacial adhesion. As a conclusion, a BmimCl/Urea mixture can be utilized as a coupling agent for agarose/talc composite films.

  19. ICIS FE&C Compliance Monitoring Screens (United States)

    U.S. Environmental Protection Agency — Web Based Training for Integrated Compliance Information System Updated Compliance Monitoring Training for ICIS Federal Enforcement and Compliance User. This...

  20. Onychomycosis by molds. Report of 78 cases. (United States)

    Bonifaz, Alexandro; Cruz-Aguilar, Pamela; Ponce, Rosa María


    A retrospective study of onychomycohosis by molds was carried out during a 14-year period (1992-2005). All cases were clinically and mycologically proven (repetitive KOH and culture) and then each of the molds was identified. A total of 5,221 cases of onychomycosis were evaluated, 78 of which were molds (1.49%). Mean patient age was 44.1 years. 75/78 cases occurred in toenails. Associated factors were detected in 39/78 (50.0%) cases, with the major ones being: peripheral vascular disease, contact with soil, and trauma. The most frequent clinical presentation was distal and lateral subungual onychomycosis (DLSO), in 54/78 cases (69%). The most frequent causative agents were: Scopulariopsis brevicaulis in 34/78 cases and Aspergillus niger in 13/78 cases. Onychomycoses by molds are infrequent; in this study they accounted for 1.49% of cases. The clinical features are virtually similar to those caused by dermatophytes, which makes the clinicomycological tests necessary.

  1. Mold Die Making. 439-322/324. (United States)

    Yunke, P.; And Others

    Each unit in this curriculum guide on mold die making contains an introduction, objectives, materials required, lessons, space for notes, figures, and diagrams. There are 10 units in this guide: (1) introduction to Electrical Discharge Machining (EDM); (2) EDM principles; (3) the single pulse; (4) EDM safety; (5) electrode material; (6) electrode…

  2. Progress in Titanium Metal Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Randall M. German


    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.

  3. Residual stresses in injection molded products

    NARCIS (Netherlands)

    Jansen, K.M.B.


    During the molding process residual stresses are formed due to thermal contraction during cooling as well as the local pressure history during solidification. In this paper a simple analytical model is reviewed which relates residual stresses, product shrinkage as well as warpage to the temperature

  4. Molding cork sheets to complex shapes (United States)

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


    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.

  5. Flexible Interior-Impression-Molding Tray (United States)

    Anders, Jeffrey E.


    Device used inside combustion chamber of complicated shape for nondestructive evaluation of qualities of welds, including such features as offset, warping, misalignment of parts, and dropthrough. Includes flexible polypropylene tray trimmed to fit desired interior surface contour. Two neodymium boron magnets and inflatable bladder attached to tray. Tray and putty inserted in cavity to make mold of interior surface.

  6. Fabrication of silicon molds for polymer optics

    DEFF Research Database (Denmark)

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


    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...


    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...

  8. Residual thermal stresses in injection molded products

    NARCIS (Netherlands)

    Zoetelief, W.F.; Douven, L.F.A.; Ingen Housz, A.J.


    Nonisothermal flow of a polymer melt in a cold mold cavity introduces stresses that are partly frozen-in during solidification. Flow-induced stresses cause anisotropy of mechanical, thermal, and optical properties, while the residual thermal stresses induce warpage and stress-cracking. In this study

  9. Injection molding of micro patterned PMMA plate

    Institute of Scientific and Technical Information of China (English)

    Yeong-Eun YOO; Tae-Hoon KIM; Tae-Jin JE; Doo-Sun CHOI; Chang-Wan KIM; Sun-Kyung KIM


    A plastic plate with surface micro features was injection molded to investigate the effect of pressure rise of melt on the replication of the micro structures. Prism pattern, which is used in many optical applications, was selected as a model pattern. The prism pattern is 50 μm in pitch and 108° in the vertical angle. The overall size of the plate was 335 mm×213 mm and the thickness of the plate varied linearly from 2.6 mm to 0.7 mm. The prism pattern was firstly machined on the nickel plated core block using micro diamond tool and this machined pattern core was installed in a mold for injection molding of prism patterned plate. Polymethyl methacrylate (PMMA) was used as a molding material. The pressure and temperature of the melt in the cavity were measured at different positions in the cavity and the replication of the pattern was also measured at the same positions. The results show that the pressure or temperature profile through the process depends on the shape and the size of the plate. The replication is affected by the temperature and pressure profiles at the early stage of filling, which is right after the melt reaches the position to be measured.

  10. Pravastatin Improves Glucose Regulation and Biocompatibility of Agarose Encapsulated Porcine Islets following Transplantation into Pancreatectomized Dogs

    Directory of Open Access Journals (Sweden)

    Lawrence S. Gazda


    Full Text Available The encapsulation of porcine islets is an attractive methodology for the treatment of Type I diabetes. In the current study, the use of pravastatin as a mild anti-inflammatory agent was investigated in pancreatectomized diabetic canines transplanted with porcine islets encapsulated in agarose-agarose macrobeads and given 80 mg/day of pravastatin (n=3 while control animals did not receive pravastatin (n=3. Control animals reached preimplant insulin requirements on days 18, 19, and 32. Pravastatin-treated animals reached preimplant insulin requirements on days 22, 27, and 50. Two animals from each group received a second macrobead implant: control animals remained insulin-free for 15 and 21 days (AUC = 3003 and 5078 mg/dL/24 hr days 1 to 15 and reached preimplant insulin requirements on days 62 and 131. Pravastatin treated animals remained insulin-free for 21 and 34 days (AUC = 1559 and 1903 mg/dL/24 hr days 1 to 15 and reached preimplant insulin requirements on days 38 and 192. Total incidence (83.3% versus 64.3% and total severity (22.7 versus 18.3 of inflammation on tissue surfaces were higher in the control group at necropsy. These findings support pravastatin therapy in conjunction with the transplantation of encapsulated xenogeneic islets for the treatment of diabetes mellitus.

  11. Covalent attachment of lipases on glyoxyl-agarose beads: application in fruit flavor and biodiesel synthesis. (United States)

    Mendes, Adriano A; de Castro, Heizir F; Giordano, Raquel L C


    The aim of this work was to prepare biocatalysts to catalyze the synthesis of butyl butyrate by esterification reaction, and the synthesis of biodiesel by transesterification of palm and babassu oils with ethanol. Lipase preparations Lipolase® (TLL1) and Lipex® 100 L (TLL2) from Thermomyces lanuginosus and Lipase AK from Pseudomonas fluorescens (PFL) were immobilized on glyoxyl-agarose beads prepared by activation with glycidol (Gly) and epichlorohydrin (Epi). The influence of immobilization time, lipase source and activating agents on the catalytic activity of the biocatalysts were evaluated in both aqueous and organic media. TLL1 immobilized on glyoxyl-agarose by 24 h of incubation resulted biocatalysts with high hydrolytic activity (varying from 1347.3 to 1470.0 IU/g of support) and thermal-stability, around 300-fold more stable than crude TLL1 extract. The maximum load of immobilized TLL1 was around 20 mg of protein/g of support. The biocatalyst prepared exhibited high activity and operational stability on the butyl butyrate synthesis by esterification after five successive cycles of 24 h each (conversion around 85-90%). Immobilized TLL1 and PFL were active in the synthesis of biodiesel by transesterification reaction. Maximum transesterification yield (≥98.5% after 48 h of reaction at 45°C) was provided by using palm oil as feedstock.

  12. Modification of a neuronal network direction using stepwise photo-thermal etching of an agarose architecture

    Directory of Open Access Journals (Sweden)

    Jimbo Yasuhiko


    Full Text Available Abstract Control over spatial distribution of individual neurons and the pattern of neural network provides an important tool for studying information processing pathways during neural network formation. Moreover, the knowledge of the direction of synaptic connections between cells in each neural network can provide detailed information on the relationship between the forward and feedback signaling. We have developed a method for topographical control of the direction of synaptic connections within a living neuronal network using a new type of individual-cell-based on-chip cell-cultivation system with an agarose microchamber array (AMCA. The advantages of this system include the possibility to control positions and number of cultured cells as well as flexible control of the direction of elongation of axons through stepwise melting of narrow grooves. Such micrometer-order microchannels are obtained by photo-thermal etching of agarose where a portion of the gel is melted with a 1064-nm infrared laser beam. Using this system, we created neural network from individual Rat hippocampal cells. We were able to control elongation of individual axons during cultivation (from cells contained within the AMCA by non-destructive stepwise photo-thermal etching. We have demonstrated the potential of our on-chip AMCA cell cultivation system for the controlled development of individual cell-based neural networks.

  13. Finite difference time domain model of ultrasound propagation in agarose scaffold containing collagen or chondrocytes. (United States)

    Inkinen, Satu I; Liukkonen, Jukka; Malo, Markus K H; Virén, Tuomas; Jurvelin, Jukka S; Töyräs, Juha


    Measurement of ultrasound backscattering is a promising diagnostic technique for arthroscopic evaluation of articular cartilage. However, contribution of collagen and chondrocytes on ultrasound backscattering and speed of sound in cartilage is not fully understood and is experimentally difficult to study. Agarose hydrogels have been used in tissue engineering applications of cartilage. Therefore, the aim of this study was to simulate the propagation of high frequency ultrasound (40 MHz) in agarose scaffolds with varying concentrations of chondrocytes (1 to 32 × 10(6) cells/ml) and collagen (1.56-200 mg/ml) using transversely isotropic two-dimensional finite difference time domain method (FDTD). Backscatter and speed of sound were evaluated from the simulated pulse-echo and through transmission measurements, respectively. Ultrasound backscatter increased with increasing collagen and chondrocyte concentrations. Furthermore, speed of sound increased with increasing collagen concentration. However, this was not observed with increasing chondrocyte concentrations. The present study suggests that the FDTD method may have some applicability in simulations of ultrasound scattering and propagation in constructs containing collagen and chondrocytes. Findings of this study indicate the significant role of collagen and chondrocytes as ultrasound scatterers and can aid in development of modeling approaches for understanding how cartilage architecture affects to the propagation of high frequency ultrasound.

  14. [Frequency dependance of compliance]. (United States)

    Gayrard, P


    Resistance of peripheral or "small" airways is only a small part of the total pulmonary resistance (Raw). Even considerable obstruction in these airways will have little effect on total resistance. Conversely this will lead to inequality in the time constants of units in parallel, and dynamic lung compliance (C dyn) shall fall as respiratory frequence increases. C dyn is measured from simultaneous recordings of transpulmonary pressure (esophageal balloon) and volume obtained from a volume displacement plethysmograph. If Raw and static compliance are found to be normal, the frequency dependance of compliance will result from peripheral airway obstruction only. Early stages of chronic airway obstruction can be established by this method. However this appear not suitable for wide-scale studies.

  15. Characteristics and influence factors of mold filling process in permanent mold with a slot gating system

    Institute of Scientific and Technical Information of China (English)

    Chang Qingming; Chen Xia; Chen Changjun; Bao Siqian; David Schwam


    The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. In this study, the slot gating system is employed to improve mold filling 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 flowing into permanent molds have been developed. Graphite molds transparent to X-rays are utilized which make it possible to observe the flow pattern through a number of vertically oriented gating systems. The investigation discovers that there are many influencing factors on the mold filling 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 fill 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 filling 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 solidification.

  16. Computer simulation for centrifugal mold filling of precision titanium castings

    Institute of Scientific and Technical Information of China (English)


    Computer simulation codes were developed based on a proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings (CASM-3D for Windows). Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings under a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section precision castings.

  17. Testing single point incremental forming molds for thermoforming operations (United States)

    Afonso, Daniel; de Sousa, Ricardo Alves; Torcato, Ricardo


    Low pressure polymer processing processes as thermoforming or rotational molding use much simpler molds then high pressure processes like injection. However, despite the low forces involved with the process, molds manufacturing for this operations is still a very material, energy and time consuming operation. The goal of the research is to develop and validate a method for manufacturing plastically formed sheets metal molds by single point incremental forming (SPIF) operation for thermoforming operation. Stewart platform based SPIF machines allow the forming of thick metal sheets, granting the required structural stiffness for the mold surface, and keeping the short lead time manufacture and low thermal inertia.

  18. The Facility and Process Technics of Polyethylene Rotational Molding

    Institute of Scientific and Technical Information of China (English)


    @@ 1. Introduction Rotational molding is the process by which hollow plastic parts are formed. It mainly processes the product which Injection molding and Blow molding can not process medium-sized, large-sized and super large-sized plastic parts. The technics may turn out a tub, dustbin, stock tank, sailboat. The research institute of Lanzhou introduces a suit of RS-16 Rotational Molding Machine from Germany Reinhadt Co. on 1990. It mainly put up experiment and smallscale production. RS-16 rotational molding machine is a single arm and di-axial equipment. It is consisting of a gas heated sintering oven, cooling chamber, mouldcarrying carriage and a controlling unit.

  19. Fabrication and Optimization of a PAGATA Gel Dosimeter: Increasing the Melting Point of the PAGAT Gel Dosimeter with Agarose Additive

    Directory of Open Access Journals (Sweden)

    Bakhtiar Azadbakht


    Full Text Available Introduction: The PAGAT polymer gel dosimeter melts at 30 ˚C and even at room temperature during the summer, so it needs to be kept in a cool place such as a refrigerator. To increase the stability of the PAGAT gel, different amounts of agarose were added to the PAGAT gel composition and the PAGATA gel was manufactured. Material and Methods: The PAGATA gel vials were irradiated using a Co-60 machine. Then, the samples were evaluated using a 1.5 T Siemens MRI scanner. The ingredients of the PAGATA normoxic gel dosimeter were 4.5% N-N' methylen-bis-acrylamide, 4.5% acrylamide, 4.5% gelatine, 5 mM tetrakis (THPC, 0.01 mM hydroquinone (HQ, 0.5% agarose and 86% de-ionized water (HPLC. Results: Melting point and sensitivity of the PAGAT gel dosimeter with addition of 0.0, 0.3, 0.5, 1.0, 1.5 and 2.0% of agarose were measured, in which the melting points were increased to 30, 82, 86, 88, 89 and 90°C and their sensitivities found to be 0.113, 0.1059, 0.125, 0.122, 0.115 and 0.2  respectively. Discussion and Conclusions: Adding agarose increased the sensitivity and background R2 of the evaluated samples. The optimum amount of agarose was found to be 0.5% regarding these parameters and also the melting point of the gel dosimeter. A value of 0.5% agarose was found to be an optimum value considering the increase of sensitivity to 0.125 and melting point to 86°C but at the expense of increasing the background R2 to 4.530.

  20. Wavelet Packet Decomposition to Characterize Injection Molding Tool Damage

    Directory of Open Access Journals (Sweden)

    Tomaž Kek


    Full Text Available This paper presents measurements of acoustic emission (AE signals during the injection molding of polypropylene with new and damaged mold. The damaged injection mold has cracks induced by laser surface heat treatment. Standard test specimens were injection molded, commonly used for examining the shrinkage behavior of various thermoplastic materials. The measured AE burst signals during injection molding cycle are presented. For injection molding tool integrity prediction, different AE burst signals’ descriptors are defined. To lower computational complexity and increase performance, the feature selection method was implemented to define a feature subset in an appropriate multidimensional space to characterize the integrity of the injection molding tool and the injection molding process steps. The feature subset was used for neural network pattern recognition of AE signals during the full time of the injection molding cycle. The results confirm that acoustic emission measurement during injection molding of polymer materials is a promising technique for characterizing the integrity of molds with respect to damage, even with resonant sensors.

  1. Ultra-precision molding of chalcogenide glass aspherical lens (United States)

    Zhang, Feng; Wang, Zhibin; Zhang, Yunlong; Su, Ying; Guo, Rui; Xu, Zengqi; Liu, Xuanmin


    With the development of infrared optical systems in military and civil areas, chalcogenide glass aspherical lens possess some advantages, such as large infrared transmission, good thermal stability performance and image quality. Aspherical lens using chalcogenide glass can satisfy the requirements of modern infrared optical systems. Therefore, precision manufacturing of chalcogenide glass aspheric has received more and more attention. The molding technology of chalcogenide glass aspheric has become a research hotspot, because it can achieve mass and low cost manufacturing. The article of molding technology is focusing on a kind of chalcogenide glass aspherical lens. We report on design and fabrication of the mold that through simulation analysis of molding. Finally, through molding test, the fabrication of mold's surface and parameters of molding has been optimized, ensuring the indicators of chalcogenide glass aspherical lens meet the requirements.

  2. Direct molding of pavement tiles made of ground tire rubber (United States)

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


    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.

  3. Pluripotential differentiation capability of human adipose-derived stem cells in a novel fibrin-agarose scaffold. (United States)

    Nieto-Aguilar, R; Serrato, D; Garzón, I; Campos, A; Alaminos, M


    The potentiality of adipose-derived stem cells (ASCs) cultured on 2D systems has been previously established. Nevertheless, very little is known so far about the differentiation potentiality of ASCs in 3D culture systems using biomaterials. In this work, we have evaluated the transdifferentiation capabilities of ASCs cultured within a novel fibrin-agarose biomaterial by histological analysis, histochemistry and immunofluorescence. Our results showed that 3D fibrin-agarose biomaterial is highly biocompatible and supports the transdifferentiation capabilities of ASCs to the osteogenic, chondrogenic, adipogenic, and neurogenic lineages.

  4. Making corporate compliance programs work. (United States)

    Chibbaro, M J; Colyer, C


    Healthcare organizations have created corporate compliance programs in an effort to adhere to Federal government recommendations, minimize the risk of wrongful behavior, and possibly reduce fines that may result from a government investigation. Compliance programs may have undetected weaknesses. Corporate compliance officers, executives, and board members need to be certain that their organization's program has sufficient infrastructure, oversight, and resources; effective education and training; an effective mechanism (hotline) to receive reports of compliance problems; and ongoing auditing and monitoring capabilities.

  5. Environmental compliance and cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Black, D.G.


    This section of the 1994 Hanford Site Environmental Report summarizes the roles of the principal agencies, organizations, and public in environmental compliance and cleanup of the Hanford Site. Regulatory oversight, the Federal Facility Agreement and Consent Order, the role of Indian tribes, public participation, and CERCLA Natural Resource Damage Assessment Trustee Activities are all discussed.

  6. Interpersonal Communication and Compliance

    NARCIS (Netherlands)

    Fennis, Bob M.; Das, Enny; Pruyn, Ad Th.H.


    Two field experiments examined the impact of the Disrupt-Then-Reframe (DTR) technique on compliance. This recently identified technique consists of a subtle, odd element in a typical scripted request (the disruption) followed by a persuasive phrase (the reframing). The authors argued that its impact

  7. An education belief worth reflection: Molding intellectuals

    Institute of Scientific and Technical Information of China (English)

    Lu Jie


    Molding intellectuals is one of the expectations people have,which comes from a deep-rooted belief in education.The humanity hypothesis of this belief is to take knowledge and the pursuit of knowledge as the only prescription for human beings.This hypothesis overturns the relation of knowledge and life.Intellectuals make scientific paradigm as the limit of knowledge.Experience and consciousness outside the paradigm are ejected from the scope of knowledge.Accordingly,knowledge of intellectuals is broken away from a human being's life.Under the domination of this conception of knowledge,the world of intellectuals has become a world deficient of meaning.The belief that education molds intellectuals should be deconstructed gradually,with criticism in both practice and theory.

  8. Hydrolysis of chickpea proteins with Flavourzyme immobilized on glyoxyl-agarose gels improves functional properties. (United States)

    del Mar Yust, María; del Carmen Millán-Linares, María; Alcaide-Hidalgo, Juan María; Millán, Francisco; Pedroche, Justo


    Chickpea protein isolate was hydrolyzed using Flavourzyme immobilized on glyoxyl-agarose beads by multipoint covalent attachment. This Flavourzyme-glyoxyl derivative, produced after 1 h of immobilization at 4 °C followed by 5.5 h at room temperature, presented approximately 51% of the endoprotease activity of Flavourzyme but was around 700 times more stable than soluble enzyme. Chickpea protein hydrolysates ranging from 1% to 10% degree of hydrolysis were produced and their chemical composition was very close to that of protein isolate used as starting material. Solubility, oil absorption, emulsifying activity and stability, and foaming capacity and stability were determined. All protein hydrolysates showed higher solubility than intact proteins, especially at pHs near isoelectric point of native chickpea proteins. Moreover, all hydrolysates had better functional properties, except emulsifying activity, than the original protein isolate.

  9. Fractionation of SWNT/nucleic acid complexes by agarose gel electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Vetcher, Alexandre A [Institute of Biomedical Sciences and Technology and Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083 (United States); Srinivasan, Srimeenakshi [Institute of Biomedical Sciences and Technology and Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083 (United States); Vetcher, Ivan A [Institute of Biomedical Sciences and Technology and Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083 (United States); Abramov, Semen M [NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083 (United States); Kozlov, Mikhail [NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083 (United States); Baughman, Ray H [NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083 (United States); Levene, Stephen D [Institute of Biomedical Sciences and Technology and Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083 (United States)


    We show that aqueous dispersions of single-walled carbon nanotubes (SWNTs), prepared with the aid of nucleic acids (NAs) such as RNA or DNA, can be separated into fractions using agarose gel electrophoresis. In a DC electric field, SWNT/NA complexes migrate in the gel in the direction of positive potential to form well-defined bands. Raman spectroscopy as a function of band position shows that nanotubes having different spectroscopic properties possess different electrophoretic mobilities. The migration patterns for SWNT/RNA and SWNT/DNA complexes differ. Parallel elution of the SWNT/NA complexes from the gel during electrophoresis and subsequent characterization by AFM reveals differences in nanotube diameter, length and curvature. The results suggest that fractionation of nanotubes can be achieved by this procedure. We discuss factors affecting the mobility of the nanotube complexes and propose analytical applications of this technique.

  10. Fractionation of SWNT/nucleic acid complexes by agarose gel electrophoresis. (United States)

    Vetcher, Alexandre A; Srinivasan, Srimeenakshi; Vetcher, Ivan A; Abramov, Semen M; Kozlov, Mikhail; Baughman, Ray H; Levene, Stephen D


    We show that aqueous dispersions of single-walled carbon nanotubes (SWNTs), prepared with the aid of nucleic acids (NAs) such as RNA or DNA, can be separated into fractions using agarose gel electrophoresis. In a DC electric field, SWNT/NA complexes migrate in the gel in the direction of positive potential to form well-defined bands. Raman spectroscopy as a function of band position shows that nanotubes having different spectroscopic properties possess different electrophoretic mobilities. The migration patterns for SWNT/RNA and SWNT/DNA complexes differ. Parallel elution of the SWNT/NA complexes from the gel during electrophoresis and subsequent characterization by AFM reveals differences in nanotube diameter, length and curvature. The results suggest that fractionation of nanotubes can be achieved by this procedure. We discuss factors affecting the mobility of the nanotube complexes and propose analytical applications of this technique.

  11. Kinetic model for whey protein hydrolysis by alcalase multipoint-immobilized on agarose gel particles

    Directory of Open Access Journals (Sweden)

    Sousa Jr R.


    Full Text Available Partial hydrolysis of whey proteins by enzymes immobilized on an inert support can either change or evidence functional properties of the produced peptides, thereby increasing their applications. The hydrolysis of sweet cheese whey proteins by alcalase, which is multipoint-immobilized on agarose gel, is studied here. A Michaelis-Menten model that takes into account competitive inhibition by the product was fitted to experimental data. The influence of pH on the kinetic parameters in the range 6.0 to 11.0 was assessed, at 50ºC. Initial reaction-rate assays in a pHstat at different concentrations of substrate were used to estimate kinetic and Michaelis-Menten parameters, k and K M. Experimental data from long-term batch assays were used to quantify the inhibition parameter, K I. The fitting of the model to the experimental data was accurate in the entire pH range.

  12. Manufacturing Science of Improved Molded Optics (United States)


    a physical point shear thinning is an unlikely explanation. In a study of friction mechanisms in polymer extrusion , Joshi et al.27 present a...41 Appendix C2 – glass extrusion paper draft 61 Appendix C3 - ring compression test paper draft (Navier law) 97 D. Protective coatings...complex thermo-mechanical behavior of an optical glass during simulation of the lens molding, extrusion and other glass forming processes. This

  13. Comparison of potassium and sodium binding in vivo and in agarose samples using TQTPPI pulse sequence (United States)

    Schepkin, Victor D.; Neubauer, Andreas; Nagel, Armin M.; Budinger, Thomas F.


    Potassium and sodium specific binding in vivo were explored at 21.1 T by triple quantum (TQ) magnetic resonance (MR) signals without filtration to achieve high sensitivities and precise quantifications. The pulse sequence used time proportional phase increments (TPPI). During simultaneous phase-time increments, it provided total single quantum (SQ) and TQ MR signals in the second dimension at single and triple quantum frequencies, respectively. The detection of both TQ and SQ signals was performed at identical experimental conditions and the resulting TQ signal equals 60 ± 3% of the SQ signal when all ions experience sufficient time for binding. In a rat head in vivo the TQ percentage relative to SQ for potassium is 41.5 ± 3% and for sodium is 16.1 ± 1%. These percentages were compared to the matching values in an agarose tissue model with MR relaxation times similar to those of mammalian brain tissue. The sodium TQ signal in agarose samples decreased in the presence of potassium, suggesting a competitive binding of potassium relative to sodium ions for the same binding sites. The TQTPPI signals correspond to almost two times more effective binding of potassium than sodium. In vivo, up to ∼69% of total potassium and ∼27% of total sodium can be regarded as bound or experiencing an association time in the range of several milliseconds. Experimental data analyses show that more than half of the in vivo total sodium TQ signal could be from extracellular space, which is an important factor for quantification of intracellular MR signals.

  14. Carbon dots rooted agarose hydrogel hybrid platform for optical detection and separation of heavy metal ions. (United States)

    Gogoi, Neelam; Barooah, Mayuri; Majumdar, Gitanjali; Chowdhury, Devasish


    A robust solid sensing platform for an on-site operational and accurate detection of heavy metal is still a challenge. We introduce chitosan based carbon dots rooted agarose hydrogel film as a hybrid solid sensing platform for detection of heavy metal ions. The fabrication of the solid sensing platform is centered on simple electrostatic interaction between the NH3+ group present in the carbon dots and the OH- groups present in agarose. Simply on dipping the hydrogel film strip into the heavy metal ion solution, in particular Cr6+, Cu2+, Fe3+, Pb2+, Mn2+, the strip displays a color change, viz., Cr6+→yellow, Cu2+→blue, Fe3+→brown, Pb2+→white, Mn2+→tan brown. The optical detection limit of the respective metal ion is found to be 1 pM for Cr6+, 0.5 μM for Cu2+, and 0.5 nM for Fe3+, Pb2+, and Mn2+ by studying the changes in UV-visible reflectance spectrum of the hydrogel film. Moreover, the hydrogel film finds applicability as an efficient filtration membrane for separation of these quintet heavy metal ions. The strategic fundamental feature of this sensing platform is the successful capability of chitosan to form colored chelates with transition metals. This proficient hybrid hydrogel solid sensing platform is thus the most suitable to employ as an on-site operational, portable, cheap colorimetric-optical detector of heavy metal ion with potential skill in their separation. Details of the possible mechanistic insight into the colorimetric detection and ion separation are also discussed.

  15. Diagnosis parameters of mold filling pattern for optimization of a casting system



    For optimal design of a gating system, the setting of diagnosis parameters is very important. In this study, the permanent mold casting process was selected because most of the other casting processes have more complicated factors that influence the mold filling pattern compared to the permanent mold casting process, such as the surface roughness of mold, gas generation from the mold wash and binder of sand mold, and the gas permeability through a sand mold, etc. Two diagnosis parameters (fl...

  16. Gastroresistant capsular device prepared by injection molding. (United States)

    Zema, Lucia; Loreti, Giulia; Melocchi, Alice; Maroni, Alessandra; Palugan, Luca; Gazzaniga, Andrea


    In the present work, the possibility of manufacturing by injection molding (IM) a gastro-resistant capsular device based on hydroxypropyl methyl cellulose acetate succinate (HPMCAS) was investigated. By performing as an enteric soluble container, such a device may provide a basis for the development of advantageous alternatives to coated dosage forms. Preliminarily, the processability of the selected thermoplastic polymer was evaluated, and the need for a plasticizer (polyethylene glycol 1500) in order to counterbalance the glassy nature of the molded items was assessed. However, some critical issues related to the physical/mechanical stability (shrinkage and warpage) and opening time of the device after the pH change were highlighted. Accordingly, an in-depth formulation study was carried out taking into account differing release modifiers potentially useful for enhancing the dissolution/disintegration rate of the capsular device at intestinal pH values. Capsule prototypes with thickness of 600 and 900 μm containing Kollicoat(®) IR and/or Explotab(®) CLV could be manufactured, and a promising performance was achieved with appropriate gastric resistance in pH 1.2 medium and break-up in pH 6.8 within 1h. These results would support the design of a dedicated mold for the development of a scalable manufacturing process.

  17. Fractal phenomena in powder injection molding process

    Institute of Scientific and Technical Information of China (English)

    郑洲顺; 曲选辉; 李云平; 雷长明; 段柏华


    The complicated characteristics of the powder were studied by fractal theory. It is illustrated that powder shape, binder structure, feedstock and mold-filling flow in powder injection molding process possess obvious fractal characteristics. Based on the result of SEM, the fractal dimensions of the projected boundary of carbonylic iron and carbonylic nickel particles were determined to be 1.074±0.006 and 1.230±0.005 respectively by box counting measurement. The results show that the fractal dimension of the projected boundary of carbonylic iron particles is close to smooth curve of one-dimension, while the fractal dimension of the projected boundary of carbonylic nickel particle is close to that of trisection Koch curve, indicating that the shape characteristics of carbonylic nickel particles can be described and analyzed by the characteristics of trisection Koch curve. It is also proposed that the fractal theory can be applied in the research of powder injection molding in four aspects.

  18. No Evidence of Viral Transmission following Long-Term Implantation of Agarose Encapsulated Porcine Islets in Diabetic Dogs

    Directory of Open Access Journals (Sweden)

    Lawrence S. Gazda


    Full Text Available We have previously described the use of a double coated agarose-agarose porcine islet macrobead for the treatment of type I diabetes mellitus. In the current study, the long-term viral safety of macrobead implantation into pancreatectomized diabetic dogs treated with pravastatin (n=3 was assessed while 2 dogs served as nonimplanted controls. A more gradual return to preimplant insulin requirements occurred after a 2nd implant procedure (days 148, 189, and >652 when compared to a first macrobead implantation (days 9, 21, and 21 in all macrobead implanted animals. In all three implanted dogs, porcine C-peptide was detected in the blood for at least 10 days following the first implant and for at least 26 days following the second implant. C-peptide was also present in the peritoneal fluid of all three implanted dogs at 6 months after 2nd implant and in 2 of 3 dogs at necropsy. Prescreening results of islet macrobeads and culture media prior to transplantation were negative for 13 viruses. No evidence of PERV or other viral transmission was found throughout the study. This study demonstrates that the long-term (2.4 years implantation of agarose-agarose encapsulated porcine islets is a safe procedure in a large animal model of type I diabetes mellitus.

  19. Direct electrochemistry of horseradish peroxidase on Nafion/[bmim]PF(6)/agarose composite film modified glassy carbon electrode. (United States)

    Fan, Da-He; Sun, Jun-Yong; Huang, Ke-Jing


    A new strategy to construct electrochemical biosensor for direct electrochemistry of horseradish peroxidase (HRP) on glassy carbon electrode (GCE) based on Nafion, agarose hydrogel and hydrophobic room-temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF(6)) composite as sensing platform has been described. [bmim]PF(6) has good conductivity and wide electrochemical windows and agarose can maintain biological activity well. Nafion/[bmim]PF(6)/agarose composite combines the advantages of [bmim]PF(6) and agarose. Electrochemical impedance spectroscopy (EIS), ultraviolet visible spectroscopy (UV-vis), fourier transform infrared (FT-IR) spectroscopy and cyclic voltammetry (CV) were used to characterize the composite film, showing that the composite film could be effectively constructed on the GCE surface and greatly enhance the electron transfer between HRP and electrode. The factors influencing the performance of the resulting biosensor were studied in detail. The biosensor responded to H(2)O(2) in the linear range from 2x10(-6) to 1.6x10(-4)M with a detection limit of 1.2x10(-7)M (based on the S/N=3). The studied biosensor exhibited good accuracy and high sensitivity. Moreover, the proposed method was economical and efficient.

  20. Use of biotin-labeled nucleic acids for protein purification and agarose-based chemiluminescent electromobility shift assays. (United States)

    Rodgers, J T; Patel, P; Hennes, J L; Bolognia, S L; Mascotti, D P


    We have employed biotin-labeled RNA to serve two functions. In one, the biotin tethers the RNA to streptavidin-agarose beads, creating an affinity resin for protein purification. In the other, the biotin functions as a label for use in a modified chemiluminescent electromobility shift assay (EMSA), a technique used to detect the formation of protein-RNA complexes. The EMSA that we describe avoids the use not only of radioactivity but also of neurotoxic acrylamide by using agarose as the gel matrix in which the free nucleic acid is separated from protein-nucleic acid complexes. After separation of free from complexed RNA in agarose, the RNA is electroblotted to positively charged nylon. The biotin-labeled RNA is readily bound by a streptavidin-alkaline phosphatase conjugate, allowing for very sensitive chemiluminescent detection ( approximately 0.1-1.0 fmol limit). Using our system, we were able to purify both known iron-responsive proteins (IRPs) from rat liver and assess their binding affinity to RNA containing the iron-responsive element (IRE) using the same batch of biotinylated RNA. We show data indicating that agarose is especially useful for cases when large complexes are formed, although smaller complexes are even better resolved.

  1. Water modeling of mold powder entrapment in slab continuous casting mold

    Institute of Scientific and Technical Information of China (English)


    The optimal parameters were determined by the water modeling of slab casting. It was found that there are mainly three types of mold powder entrapment in slab continuous casting, i.e., the entrapment caused by the shearing flow near the narrow face of mold, the entrapment caused by vortexes around the submerged entry nozzle (SEN), and the entrapment caused by the Ar bubbling.Both the velocity of the surface flow and the level fluctuation of the liquids are enlarged with increasing the casting speed, reducing the submersion depth of SEN, decreasing the downward angles of the nozzle outlets, and increasing the Ar flowrate, all of which increase the tendency of mold powder entrapment. Among the four above-mentioned factors, casting speed has the largest effect.

  2. Orchestrated Session Compliance

    Directory of Open Access Journals (Sweden)

    Franco Barbanera


    Full Text Available We investigate the notion of orchestrated compliance for client/server interactions in the context of session contracts. Devising the notion of orchestrator in such a context makes it possible to have orchestrators with unbounded buffering capabilities and at the same time to guarantee any message from the client to be eventually delivered by the orchestrator to the server, while preventing the server from sending messages which are kept indefinitely inside the orchestrator. The compliance relation is shown to be decidable by means of 1 a procedure synthesising the orchestrators, if any, making a client compliant with a server, and 2 a procedure for deciding whether an orchestrator behaves in a proper way as mentioned before.

  3. Checking Security Policy Compliance

    CERN Document Server

    Gowadia, Vaibhav; Kudo, Michiharu


    Ensuring compliance of organizations to federal regulations is a growing concern. This paper presents a framework and methods to verify whether an implemented low-level security policy is compliant to a high-level security policy. Our compliance checking framework is based on organizational and security metadata to support refinement of high-level concepts to implementation specific instances. Our work uses the results of refinement calculus to express valid refinement patterns and their properties. Intuitively, a low-level security policy is compliant to a high-level security policy if there is a valid refinement path from the high-level security policy to the low-level security policy. Our model is capable of detecting violations of security policies, failures to meet obligations, and capability and modal conflicts.

  4. Agent Architectures for Compliance (United States)

    Burgemeestre, Brigitte; Hulstijn, Joris; Tan, Yao-Hua

    A Normative Multi-Agent System consists of autonomous agents who must comply with social norms. Different kinds of norms make different assumptions about the cognitive architecture of the agents. For example, a principle-based norm assumes that agents can reflect upon the consequences of their actions; a rule-based formulation only assumes that agents can avoid violations. In this paper we present several cognitive agent architectures for self-monitoring and compliance. We show how different assumptions about the cognitive architecture lead to different information needs when assessing compliance. The approach is validated with a case study of horizontal monitoring, an approach to corporate tax auditing recently introduced by the Dutch Customs and Tax Authority.

  5. Effect of mold treatment by solvent on PDMS molding into nanoholes (United States)

    Con, Celal; Cui, Bo


    Polydimethylsiloxane (PDMS) is the most popular and versatile material for soft lithography due to its flexibility and easy fabrication by molding process. However, for nanoscale patterns, it is challenging to fill uncured PDMS into the holes or trenches on the master mold that is coated with a silane anti-adhesion layer needed for clean demolding. PDMS filling was previously found to be facilitated by diluting it with toluene or hexane, which was attributed to the great reduction of viscosity for diluted PDMS. Here, we suggest that the reason behind the improved filling for diluted PDMS is that the diluent solvent increases in situ the surface energy of the silane-treated mold and thus the wetting of PDMS to the mold surface. We treated the master mold surface (that was already coated with a silane anti-adhesion monolayer) with toluene or hexane, and found that the filling by undiluted PMDS into the nanoscale holes on the master mold was improved despite the high viscosity of the undiluted PDMS. A simple estimation based on capillary filing into a channel also gives a filling time on the millisecond scale, which implies that the viscosity of PMDS should not be the limiting factor. We achieved a hole filling down to sub-200-nm diameter that is smaller than those of the previous studies using regular Sylgard PDMS (not hard PDMS, Dow Corning Corporation, Midland, MI, USA). However, we are not able to explain using a simple argument based on wetting property why smaller, e.g., sub-100-nm holes, cannot be filled, for which we suggested a few possible factors for its explanation.

  6. Rheological and mechanical behavior of polyacrylamide hydrogels chemically crosslinked with allyl agarose for two-dimensional gel electrophoresis. (United States)

    Suriano, R; Griffini, G; Chiari, M; Levi, M; Turri, S


    Two-dimensional (2-D) gel electrophoresis currently represents one of the most standard techniques for protein separation. In addition to the most commonly employed polyacrylamide crosslinked hydrogels, acrylamide-agarose copolymers have been proposed as promising systems for separation matrices in 2-D electrophoresis, because of the good resolution of both high and low molecular mass proteins made possible by careful control and optimization of the hydrogel pore structure. As a matter of fact, a thorough understanding of the nature of the hydrogel pore structure as well as of the parameters by which it is influenced is crucial for the design of hydrogel systems with optimal sieving properties. In this work, a series of acrylamide-based hydrogels covalently crosslinked with different concentrations of allyl agarose (0.2-1%) is prepared and characterized by creep-recovery measurements, dynamic rheology and tensile tests, in the attempt to gain a clearer understanding of structure-property relationships in crosslinked polyacrylamide-based hydrogels. The rheological and mechanical properties of crosslinked acrylamide-agarose hydrogels are found to be greatly affected by crosslinker concentration. Dynamic rheological tests show that hydrogels with a percentage of allyl agarose between 0.2% and 0.6% have a low density of elastically effective crosslinks, explaining the good separation of high molecular mass proteins in 2-D gel electrophoresis. Over the same range of crosslinker concentration, creep-recovery measurements reveal the presence of non-permanent crosslinks in the hydrogel network that justifies the good resolution of low molecular mass proteins as well. In tensile tests, the hydrogel crosslinked with 0.4% of allyl agarose exhibits the best results in terms of mechanical strength and toughness. Our results show how the control of the viscoelastic and the mechanical properties of these materials allow the design of mechanically stable hydrogels with improved

  7. Tuning mechanical performance of poly(ethylene glycol) and agarose interpenetrating network hydrogels for cartilage tissue engineering. (United States)

    Rennerfeldt, Deena A; Renth, Amanda N; Talata, Zsolt; Gehrke, Stevin H; Detamore, Michael S


    Hydrogels are attractive for tissue engineering applications due to their incredible versatility, but they can be limited in cartilage tissue engineering applications due to inadequate mechanical performance. In an effort to address this limitation, our team previously reported the drastic improvement in the mechanical performance of interpenetrating networks (IPNs) of poly(ethylene glycol) diacrylate (PEG-DA) and agarose relative to pure PEG-DA and agarose networks. The goal of the current study was specifically to determine the relative importance of PEG-DA concentration, agarose concentration, and PEG-DA molecular weight in controlling mechanical performance, swelling characteristics, and network parameters. IPNs consistently had compressive and shear moduli greater than the additive sum of either single network when compared to pure PEG-DA gels with a similar PEG-DA content. IPNs withstood a maximum stress of up to 4.0 MPa in unconfined compression, with increased PEG-DA molecular weight being the greatest contributing factor to improved failure properties. However, aside from failure properties, PEG-DA concentration was the most influential factor for the large majority of properties. Increasing the agarose and PEG-DA concentrations as well as the PEG-DA molecular weight of agarose/PEG-DA IPNs and pure PEG-DA gels improved moduli and maximum stresses by as much as an order of magnitude or greater compared to pure PEG-DA gels in our previous studies. Although the viability of encapsulated chondrocytes was not significantly affected by IPN formulation, glycosaminoglycan (GAG) content was significantly influenced, with a 12-fold increase over a three-week period in gels with a lower PEG-DA concentration. These results suggest that mechanical performance of IPNs may be tuned with partial but not complete independence from biological performance of encapsulated cells.

  8. Tuning mechanical performance of poly(ethylene glycol) and agarose interpenetrating network hydrogels for cartilage tissue engineering (United States)

    Rennerfeldt, DA; Renth, AN; Talata, Z; Gehrke, SH; Detamore, MS


    Hydrogels are attractive for tissue engineering applications due to their incredible versatility, but they can be limited in cartilage tissue engineering applications due to inadequate mechanical performance. In an effort to address this limitation, our team previously reported the drastic improvement in the mechanical performance of interpenetrating networks (IPNs) of poly(ethylene glycol) diacrylate (PEG-DA) and agarose relative to pure PEG-DA and agarose networks. The goal of the current study was specifically to determine the relative importance of PEG-DA concentration, agarose concentration, and PEG-DA molecular weight in controlling mechanical performance, swelling characteristics, and network parameters. IPNs consistently had compressive and shear moduli greater than the additive sum of either single network when compared to pure PEG-DA gels with a similar PEG-DA content. IPNs withstood a maximum stress of up to 4.0 MPa in unconfined compression, with increased PEG-DA molecular weight being the greatest contributing factor to improved failure properties. However, aside from failure properties, PEG-DA concentration was the most influential factor for the large majority of properties. Increasing the agarose and PEG-DA concentrations as well as the PEG-DA molecular weight of agarose/PEG-DA IPNs and pure PEG-DA gels improved moduli and maximum stresses by as much as an order of magnitude or greater compared to pure PEG-DA gels in our previous studies. Although the viability of encapsulated chondrocytes was not significantly affected by IPN formulation, glycosaminoglycan (GAG) content was significantly influenced, with a 12-fold increase over a three-week period in gels with a lower PEG-DA concentration. These results suggest that mechanical performance of IPNs may be tuned with partial but not complete independence from biological performance of encapsulated cells. PMID:23932504

  9. Mold deformation in soft UV-nanoimprint lithography

    Institute of Scientific and Technical Information of China (English)


    UV-nanoimprint lithography (UV-NIL) using a soft mold is a promising technique with low cost and high throughput for producing the submicron scale large-area patterns. However, the deformations of the soft mold during imprinting process which can cause serious consequences have to be understood for the practical application of the process. This paper investigated the deformation of the soft mold by theoretical analyses, numerical simulations, and experimental studies. We simulated the mold deformation using a simplified model and finite element method. The simulation and the related experimental results agree well with each other. Through the investigation, the mechanism and affected factors of the mold deformation are revealed, and some useful conclusions have been achieved. These results will be valuable in optimizing the imprinting process conditions and mold design for improving the quality of transferred patterns.

  10. Three-Dimensional Modeling of Glass Lens Molding

    DEFF Research Database (Denmark)

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


    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...

  11. Snow molds: A group of fungi that prevail under snow. (United States)

    Matsumoto, Naoyuki


    Snow molds are a group of fungi that attack dormant plants under snow. In this paper, their survival strategies are illustrated with regard to adaptation to the unique environment under snow. Snow molds consist of diverse taxonomic groups and are divided into obligate and facultative fungi. Obligate snow molds exclusively prevail during winter with or without snow, whereas facultative snow molds can thrive even in the growing season of plants. Snow molds grow at low temperatures in habitats where antagonists are practically absent, and host plants deteriorate due to inhibited photosynthesis under snow. These features characterize snow molds as opportunistic parasites. The environment under snow represents a habitat where resources available are limited. There are two contrasting strategies for resource utilization, i.e., individualisms and collectivism. Freeze tolerance is also critical for them to survive freezing temperatures, and several mechanisms are illustrated. Finally, strategies to cope with annual fluctuations in snow cover are discussed in terms of predictability of the habitat.

  12. Replication of optical microlens arrays using photoresist coated molds

    DEFF Research Database (Denmark)

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


    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...... the light engine. Polymer injection molded microlens arrays were produced from both the rough and coated molds and have been characterized for lenslet parameters, surface quality, light scattering, and acceptance angle. The surface roughness (Ra) is improved approximately by a factor of two after...... the coating process and the light scattering is reduced so that the molded microlens array can be used for the color mixing application. The measured accepted angle of the microlens array is 40° which is in agreement with simulations....

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

    DEFF Research Database (Denmark)

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


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

  14. Shape retention of injection molded stainless steel compacts

    Institute of Scientific and Technical Information of China (English)

    LI Yi-min; K.A.Khalil; HUANG Bai-yun


    The effects of the binder composition, the powder loading, the thermal properties of feedstocks, and the injection molding parameters on the compact shape retention for metal injection molding 17-4PH stainless steel were investigated. The high-density polyethylene is more effective than ethylene vinyl acetate as a second component of the wax-based binder to retain compact shape due to its higher pyrolytic temperature and less heat of fusion. The compact distortion decreases with increasing the powder loading, molding pressure and molding temperature. There exists an optimal process combination including the powder loading of 68%, molding pressure of 120 MPa and molding temperature of 150 ℃. Under this process condition, the percentage of distorted compacts is the lowest.

  15. Effect of superheat, mold, and casting materials on the metal/mold interfacial heat transfer during solidification in graphite-lined permanent molds (United States)

    Prabhu, K. Narayan; Suresha, K. M.


    Heat transfer during the solidification of an Al-Cu-Si alloy (LM4) and commercial pure tin in single steel, graphite, and graphite-lined metallic (composite) molds was investigated. Experiments were carried out at three different superheats. In the case of composite molds, the effect of the thickness of the graphite lining and the outer wall on heat transfer was studied. Temperatures at known locations inside the mold and casting were used to solve the Fourier heat conduction equation inversely to yield the casting/mold interfacial heat flux transients. Increased melt superheats and higher thermal conductivity of the mold material led to an increase in the peak heat flux at the metal/mold interface. Factorial experiments indicated that the mold material had a significant effect on the peak heat flux at the 5% level of significance. The ratio of graphite lining to outer steel wall and superheat had a significant effect on the peak heat flux in significance range varying between 5 and 25%. A heat flux model was proposed to estimate the maximum heat flux transients at different superheat levels of 25 to 75 °C for any metal/mold combinations having a thermal diffusivity ratio (α R) varying between 0.25 and 6.96. The heat flow models could be used to estimate interfacial heat flux transients from the thermophysical properties of the mold and cast materials and the melt superheat. Metallographic analysis indicated finer microstructures for castings poured at increased melt superheats and cast in high-thermal diffusivity molds.

  16. Virtual Mold Technique in Thermal Stress Analysis during Casting Process

    Institute of Scientific and Technical Information of China (English)

    Si-Young Kwak; Jae-Wook Baek; Jeong-Ho Nam; Jeong-Kil Choi


    It is important to analyse the casting product and the mold at the same time considering thermal contraction of the casting and thermal expansion of the mold. The analysis considering contact of the casting and the mold induces the precise prediction of stress distribution and the defect such as hot tearing. But it is difficult to generate FEM mesh for the interface of the casting and the mold. Moreover the mesh for the mold domain spends lots of computational time and memory for the analysis due to a number of meshes. Consequently we proposed the virtual mold technique which only uses mesh of the casting part for thermal stress analysis in casting process. The spring bar element in virtual mold technique is used to consider the contact of the casting and the mold. In general, a volume of the mold is much bigger than that of casting part, so the proposed technique decreases the number of mesh and saves the computational memory and time greatly. In this study, the proposed technique was verified by the comparison with the traditional contact technique on a specimen. And the proposed technique gave satisfactory results.

  17. 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)


    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. Effect of mold rotation on the bifilar electroslag remelting process (United States)

    Shi, Xiao-fang; Chang, Li-zhong; Wang, Jian-jun


    A novel electroslag furnace with a rotating mold was fabricated, and the effects of mold rotational speed on the electroslag remelting process were investigated. The results showed that the chemical element distribution in ingots became uniform and that their compact density increased when the mold rotational speed was increased from 0 to 28 r/min. These results were attributed to a reasonable mold speed, which resulted in a uniform temperature in the slag pool and scattered the metal droplets randomly in the metal pool. However, an excessive rotational speed caused deterioration of the solidification structure. When the mold rotational speeds was increased from 0 to 28 r/min, the size of Al2O3 inclusions in the electroslag ingot decreased from 4.4 to 1.9 μm. But the excessive mold rotational speed would decrease the ability of the electroslag remelting to remove the inclusions. The remelting speed gradually increased, which resulted in reduced power consumption with increasing mold rotational speed. This effect was attributed to accelerated heat exchange between the consumable electrode and the molten slag, which resulted from mold rotation. Nevertheless, when the rotational speed reached 28 r/min, the remelting speed did not change because of limitations of metal heat conduction. Mold rotation also improved the surface quality of the ingots by promoting a uniform temperature distribution in the slag pool.

  19. A hybrid optimization approach in non-isothermal glass molding (United States)

    Vu, Anh-Tuan; Kreilkamp, Holger; Krishnamoorthi, Bharathwaj Janaki; Dambon, Olaf; Klocke, Fritz


    Intensively growing demands on complex yet low-cost precision glass optics from the today's photonic market motivate the development of an efficient and economically viable manufacturing technology for complex shaped optics. Against the state-of-the-art replication-based methods, Non-isothermal Glass Molding turns out to be a promising innovative technology for cost-efficient manufacturing because of increased mold lifetime, less energy consumption and high throughput from a fast process chain. However, the selection of parameters for the molding process usually requires a huge effort to satisfy precious requirements of the molded optics and to avoid negative effects on the expensive tool molds. Therefore, to reduce experimental work at the beginning, a coupling CFD/FEM numerical modeling was developed to study the molding process. This research focuses on the development of a hybrid optimization approach in Non-isothermal glass molding. To this end, an optimal configuration with two optimization stages for multiple quality characteristics of the glass optics is addressed. The hybrid Back-Propagation Neural Network (BPNN)-Genetic Algorithm (GA) is first carried out to realize the optimal process parameters and the stability of the process. The second stage continues with the optimization of glass preform using those optimal parameters to guarantee the accuracy of the molded optics. Experiments are performed to evaluate the effectiveness and feasibility of the model for the process development in Non-isothermal glass molding.

  20. New active site oriented glyoxyl-agarose derivatives of Escherichia coli penicillin G acylase

    Directory of Open Access Journals (Sweden)

    Terreni Marco


    Full Text Available Abstract Background Immobilized Penicillin G Acylase (PGA derivatives are biocatalysts that are industrially used for the hydrolysis of Penicillin G by fermentation and for the kinetically controlled synthesis of semi-synthetic β-lactam antibiotics. One of the most used supports for immobilization is glyoxyl-activated agarose, which binds the protein by reacting through its superficial Lys residues. Since in E. coli PGA Lys are also present near the active site, an immobilization that occurs through these residues may negatively affect the performance of the biocatalyst due to the difficult diffusion of the substrate into the active site. A preferential orientation of the enzyme with the active site far from the support surface would be desirable to avoid this problem. Results Here we report how it is possible to induce a preferential orientation of the protein during the binding process on aldehyde activated supports. A superficial region of PGA, which is located on the opposite side of the active site, is enriched in its Lys content. The binding of the enzyme onto the support is consequently forced through the Lys rich region, thus leaving the active site fully accessible to the substrate. Different mutants with an increasing number of Lys have been designed and, when active, immobilized onto glyoxyl agarose. The synthetic performances of these new catalysts were compared with those of the immobilized wild-type (wt PGA. Our results show that, while the synthetic performance of the wt PGA sensitively decreases after immobilization, the Lys enriched mutants have similar performances to the free enzyme even after immobilization. We also report the observations made with other mutants which were unable to undergo a successful maturation process for the production of active enzymes or which resulted toxic for the host cell. Conclusion The desired orientation of immobilized PGA with the active site freely accessible can be obtained by increasing

  1. Investigations on injection molded, glass-fiber reinforced polyamide 6 integral foams using breathing mold technology (United States)

    Roch, A.; Kehret, L.; Huber, T.; Henning, F.; Elsner, P.


    Investigations on PA6-GF50 integral foams have been carried out using different material systems: longfiber- and shortfiber-reinforced PA6 as well as unreinforced PA6 as a reference material. Both chemical and physical blowing agents were applied. Breathing mold technology (decompression of the mold) was selected for the foaming process. The integral foam design, which can be conceived as a sandwich structure, helps to save material in the neutral axis area and maintains a distance between load-bearing, unfoamed skin layers. For all test series an initial mold gap of 2.5 mm was chosen and the same amount of material was injected. In order to realize different density reductions, the mold opening stroke was varied. The experiments showed that, at a constant mass per unit area, integral polyamide 6 foams have a significantly higher bending stiffness than compact components, due to their higher area moment of inertia after foaming. At a constant surface weight the bending stiffness in these experiments could be increased by up to 600 %. Both shortfiber- and longfiber-reinforced polyamide 6 showed an increase in energy absorption during foaming.

  2. Injection-molded capsular device for oral pulsatile release: development of a novel mold. (United States)

    Zema, Lucia; Loreti, Giulia; Macchi, Elena; Foppoli, Anastasia; Maroni, Alessandra; Gazzaniga, Andrea


    The development of a purposely devised mold and a newly set up injection molding (IM) manufacturing process was undertaken to prepare swellable/erodible hydroxypropyl cellulose-based capsular containers. When orally administered, such devices would be intended to achieve pulsatile and/or colonic time-dependent delivery of drugs. An in-depth evaluation of thermal, rheological, and mechanical characteristics of melt formulations/molded items made of the selected polymer (Klucel® LF) with increasing amounts of plasticizer (polyethylene glycol 1500, 5%-15% by weight) was preliminarily carried out. On the basis of the results obtained, a new mold was designed that allowed, through an automatic manufacturing cycle of 5 s duration, matching cap and body items to be prepared. These were subsequently filled and coupled to give a closed device of constant 600 μm thickness. As compared with previous IM systems having the same composition, such capsules showed improved closure mechanism, technological properties, especially in terms of reproducibility of the shell thickness, and release performance. Moreover, the ability of the capsular container to impart a constant lag phase before the liberation of the contents was demonstrated irrespective of the conveyed formulation.

  3. Mold Filling Analysis in Vacuum Infusion Molding Process Based on a High-Permeable Medium

    Institute of Scientific and Technical Information of China (English)

    Yingdan ZHU; Hua TAN; Jihui WANG


    The objective of this paper is to understand the flow mechanism through visualization experiments and discuss theinfluence of process parameters on mold filling process. A 2D leakage flow model is developed to simulate the moldingprocess, and the simulation results show good agreement with experiments.

  4. The flexible resin transfer molding (FRTM) process (United States)

    Foley, Michael F.


    An innovative composite manufacturing process, FRTM, which is based on detailed cost analysis intended to be 'cost effective by design', is described. FRTM is based on a combination of the technical characteristics and respective favorable economics of diaphragm forming, and resin transfer molding. The process control system determines the optimal time for compaction and forming using an empirical resin polymerization model, a fluid flow model, and dielectric sensing of in-situ resin properties. The modified FRTM process is capable of producing high-quality parts with low thickness variation, low void content, and high fiber volume.

  5. Extrinsic incentives and tax compliance


    Sour, Laura; Gutiérrez Andrade, Miguel Ángel


    This paper models the impact of extrinsic incentives in a tax compliance model. It also provides experimental evidence that confirms the existence of a positive relationship between rewards and tax compliance. If individuals are audited, rewards for honest taxpayers are effective in increasing the level of tax compliance. These results are particularly relevant in countries where there is little respect for tax law since rewards can contribute to crowding in the intrinsic motivation to comply.

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



    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 obs...

  7. Integrally cored ceramic investment casting mold fabricated by ceramic stereolithography (United States)

    Bae, Chang-Jun

    Superalloy airfoils are produced by investment casting (IC), which uses ceramic cores and wax patterns with ceramic shell molds. Hollow cored superalloy airfoils in a gas turbine engine are an example of complex IC parts. The complex internal hollow cavities of the airfoil are designed to conduct cooling air through one or more passageways. These complex internal passageways have been fabricated by a lost wax process requiring several processing steps; core preparation, injection molding for wax pattern, and dipping process for ceramic shell molds. Several steps generate problems such as high cost and decreased accuracy of the ceramic mold. For example, costly tooling and production delay are required to produce mold dies for complex cores and wax patterns used in injection molding, resulting in a big obstacle for prototypes and smaller production runs. Rather than using separate cores, patterns, and shell molds, it would be advantageous to directly produce a mold that has the casting cavity and the ceramic core by one process. Ceramic stereolithography (CerSLA) can be used to directly fabricate the integrally cored ceramic casting mold (ICCM). CerSLA builds ceramic green objects from CAD files from many thin liquid layers of powder in monomer, which are solidified by polymerization with a UV laser, thereby "writing" the design for each slice. This dissertation addresses the integrally cored casting ceramic mold (ICCM), the ceramic core with a ceramic mold shell in a single patternless construction, fabricated by ceramic stereolithography (CerSLA). CerSLA is considered as an alternative method to replace lost wax processes, for small production runs or designs too complex for conventional cores and patterns. The main topic is the development of methods to successfully fabricate an ICCM by CerSLA from refractory silica, as well as related issues. The related issues are the segregation of coarse fused silica powders in a layer, the degree of segregation parameter to

  8. Upregulation of matrix synthesis in chondrocyte-seeded agarose following sustained bi-axial cyclic loading

    Directory of Open Access Journals (Sweden)

    Belinda Pingguan-Murphy


    Full Text Available OBJECTIVES: The promotion of extracellular matrix synthesis by chondrocytes is a requisite part of an effective cartilage tissue engineering strategy. The aim of this in vitro study was to determine the effect of bi-axial cyclic mechanical loading on cell proliferation and the synthesis of glycosaminoglycans by chondrocytes in threedimensional cultures. METHOD: A strain comprising 10% direct compression and 1% compressive shear was applied to bovine chondrocytes seeded in an agarose gel during two 12-hour conditioning periods separated by a 12-hour resting period. RESULTS: The bi-axial-loaded chondrocytes demonstrated a significant increase in glycosaminoglycan synthesis compared with samples exposed to uni-axial or no loading over the same period (p<0.05. The use of a free-swelling recovery period prior to the loading regime resulted in additional glycosaminoglycan production and a significant increase in DNA content (p<0.05, indicating cell proliferation. CONCLUSIONS: These results demonstrate that the use of a bi-axial loading regime results in increased matrix production compared with uni-axial loading.

  9. Stabilization of Candida antarctica Lipase B (CALB Immobilized on Octyl Agarose by Treatment with Polyethyleneimine (PEI

    Directory of Open Access Journals (Sweden)

    Sara Peirce


    Full Text Available Lipase B from Candida antarctica (CALB was immobilized on octyl agarose (OC and physically modified with polyethyleneimine (PEI in order to confer a strong ion exchange character to the enzyme and thus enable the immobilization of other enzymes on its surface. The enzyme activity was fully maintained during the coating and the thermal stability was marginally improved. The enzyme release from the support by incubation in the non-ionic detergent Triton X-100 was more difficult after the PEI-coating, suggesting that some intermolecular physical crosslinking had occurred, making this desorption more difficult. Thermal stability was marginally improved, but the stability of the OCCALB-PEI was significantly better than that of OCCALB during inactivation in mixtures of aqueous buffer and organic cosolvents. SDS-PAGE analysis of the inactivated biocatalyst showed the OCCALB released some enzyme to the medium during inactivation, and this was partially prevented by coating with PEI. This effect was obtained without preventing the possibility of reuse of the support by incubation in 2% ionic detergents. That way, this modified CALB not only has a strong anion exchange nature, while maintaining the activity, but it also shows improved stability under diverse reaction conditions without affecting the reversibility of the immobilization.

  10. Agarose Microchambers for Long-term Calcium Imaging of Caenorhabditis elegans. (United States)

    Turek, Michal; Besseling, Judith; Bringmann, Henrik


    Behavior is controlled by the nervous system. Calcium imaging is a straightforward method in the transparent nematode Caenorhabditis elegans to measure the activity of neurons during various behaviors. To correlate neural activity with behavior, the animal should not be immobilized but should be able to move. Many behavioral changes occur during long time scales and require recording over many hours of behavior. This also makes it necessary to culture the worms in the presence of food. How can worms be cultured and their neural activity imaged over long time scales? Agarose Microchamber Imaging (AMI) was previously developed to culture and observe small larvae and has now been adapted to study all life stages from early L1 until the adult stage of C. elegans. AMI can be performed on various life stages of C. elegans. Long-term calcium imaging is achieved without immobilizing the animals by using short externally triggered exposures combined with an electron multiplying charge-coupled device (EMCCD) camera recording. Zooming out or scanning can scale up this method to image up to 40 worms in parallel. Thus, a method is described to image behavior and neural activity over long time scales in all life stages of C. elegans.

  11. Dense Pellicular Agarose-Glass Beads for Expanded Bed Application: Flow Hydrodynamics and Solid Phase Classifications

    Institute of Scientific and Technical Information of China (English)

    周鑫; 史清洪; 白姝; 孙彦


    Two dense pellicular agarose-glass matrices of different sizes and densities, i.e., AG-S and AG-L, have been characterized for their bed expansion behavior, flow hydrodynamics and particle classifications in an expanded bed system. A 26 mm ID column with side ports was used for sampling the liquid-solid suspension during expanded bed operations. Measurements of the collected solid phase at different column positions yielded the particle size and density distribution data. It was found that the composite matrices showed particle size as well as density classifications along the column axis, i.e., both the size and density of each matrix decreased with increasing the axial bed height. Their axial classifications were expressed by a correlation related to both the particle size and density as a function of the dimensionless axial bed height. The correlation was found to fairly describe the solid phase classifications in the expanded bed system. Moreover, it can also be applied to other two commercial solid matrices designed for expanded bed applications.

  12. In vivo remineralization of dentin using an agarose hydrogel biomimetic mineralization system (United States)

    Han, Min; Li, Quan-Li; Cao, Ying; Fang, Hui; Xia, Rong; Zhang, Zhi-Hong


    A novel agarose hydrogel biomimetic mineralization system loaded with calcium and phosphate was used to remineralize dentin and induce the oriented densely parallel packed HA layer on defective dentin surface in vivo in a rabbit model. Firstly, the enamel of the labial surface of rabbits’ incisor was removed and the dentin was exposed to oral environment. Secondly, the hydrogel biomimetic mineralization system was applied to the exposed dentin surface by using a custom tray. Finally, the teeth were extracted and evaluated by scanning electron microscopy, X-ray diffraction, and nanoindentation test after a certain time of mineralization intervals. The regenerated tissue on the dentin surface was composed of highly organised HA crystals. Densely packed along the c axis, these newly precipitated HA crystals were perpendicular to the underlying dental surface with a tight bond. The demineralized dentin was remineralized and dentinal tubules were occluded by the grown HA crystals. The nanohardness and elastic modulus of the regenerated tissue were similar to natural dentin. The results indicated a potential clinical use for repairing dentin-exposed related diseases, such as erosion, wear, and dentin hypersensitivity.

  13. Purification of prenylated proteins by affinity chromatography on cyclodextrin-modified agarose (United States)

    Chung, Jinhwa A.; Wollack, James W.; Hovlid, Marisa L.; Okesli, Ayse; Chen, Yan; Mueller, Joachim D.; Distefano, Mark D.; Taton, T. Andrew


    Although protein prenylation is widely studied, there are few good methods for isolating prenylated proteins from their non-prenylated relatives. We report that crosslinked agarose (e.g., Sepharose) chromatography media that has been chemically functionalized with β-cyclodextrin (β-CD) is extremely effective in affinity chromatography of prenylated proteins. In this study, a variety of proteins with C-terminal prenylation target (“CAAX box”) sequences were enzymatically prenylated in vitro with natural and non-natural prenyl diphosphate substrates. The prenylated protein products could then be isolated from starting materials by gravity chromatography or fast protein liquid chromatography (FPLC) on a β-CD-Sepharose column. One particular prenylation reaction—farnesylation of a mCherry-CAAX fusion construct—was studied in detail. In this case, purified farnesylated product was unambiguously identified by electrospray mass spectrometry. In addition, when mCherry-CAAX was prenylated with a non-natural, functional isoprenoid substrate, the functional group was maintained by chromatography on β-CD-Sepharose, such that the resulting protein could be selectively bound at its C terminus to complementary functionality on a solid substrate. Finally, β-CD-Sepharose FPLC was used to isolate prenylated mCherry-CAAX from crude HeLa cell lysate, as a model for purifying prenylated proteins from cell extracts. We propose that this method could be generally useful to the community of researchers studying protein prenylation. PMID:18834849

  14. Penetration Deep into Tissues of Reactive Oxygen Species Generated in Floating-Electrode Dielectric Barrier Discharge (FE-DBD): in Vitro Agarose Gel Model Mimicking an Open Wound

    CERN Document Server

    Dobrynin, Danil; Friedman, Gary; Fridman, Alexander


    In this manuscript we present an in vitro model based on agarose gel that can be used to simulate a dirty, oily, bloody, and morphologically complex surface of, for example, an open wound. We show this models effectiveness in simulating depth of penetration of reactive species generated in plasma deep into tissue of a rat and confirm the penetration depths with agarose gel model. We envision that in the future such a model could be used to study plasma discharges (and other modalities) and minimize the use of live animals: plasma can be optimized on the agarose gel wound model and then finally verified using an actual wound.

  15. Formalizing and applying compliance patterns for business process compliance

    NARCIS (Netherlands)

    Elgammal, A.F.S.A.; Türetken, O.; van den Heuvel, W.J.A.M.; Papazoglou, M.


    Today’s enterprises demand a high degree of compliance of business processes to meet diverse regulations and legislations. Several industrial studies have shown that compliance management is a daunting task, and organizations are still struggling and spending billions of dollars annually to ensure a

  16. Composite fabrication via resin transfer molding technology

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  17. Rotational molding of bio-polymers (United States)

    Greco, Antonio; Maffezzoli, Alfonso; Forleo, Stefania


    This paper is aimed to study the suitability of bio-polymers, including poly-lactic acid (PLLA) and Mater-Bi, for the production of hollow components by rotational molding. In order to reduce the brittleness of PLLA, the material was mixed with two different plasticizers, bis-ethyl-hexyl-phthalate (DEHP) and poly-ethylene-glycol (PEG). The materials were characterized in terms of sinterability. To this purpose, thermomechanical (TMA) analysis was performed at different heating rates, in order to identify the endset temperatures of densification and the onset temperatures of degradation. Results obtained indicated that the materials are characterized by a very fast sintering process, occurring just above the melting temperature, and an adequately high onset of degradation. The difference between the onset of degradation and the endset of sintering, defined as the processing window of the polymer, is sufficiently wide, indicating that the polymers can be efficiently processed by rotational molding. Therefore, a laboratory scale apparatus was used for the production of PLLA and Mater-Bi prototypes. The materials were processed using very similar conditions to those used for LLDPE. The production of void-free samples of uniform wall thickness was considered as an indication of the potentiality of the process for the production of biodegradable containers.

  18. Production of Liquid Metal Spheres by Molding

    Directory of Open Access Journals (Sweden)

    Mohammed G. Mohammed


    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.

  19. Lighting molded optics: Design and manufacturing

    Directory of Open Access Journals (Sweden)

    Kočárková H.


    Full Text Available Proper design and manufacturing of glass molded lenses need to be performed in several steps. The whole process from customer requirements to f nal functional product is shown on two examples - a lens for street light and a lens for spot light with narrow lighting angle. After discussing customer requirements, optical design is made. Thanks to various commercial softwares with optimization, manufacturer of the lens can work as well as a designer which enables simplif cation and acceleration of lens manufacturing, since limitations of the manufacturing process are considered during creation of the design. When the prototype is made, its functionality needs to be evaluated. This work shows measurement of light distribution for street light lens in a dark room using goniometer and measurement of light intensity for spot lens f xed on an optical bench. These measurements can reveal the root cause in case of lens malfunction, which enables to optimize manufacturing process or modify lens design accordingly. Designing, manufacturing and evaluation of molded optics under one roof enables creation of easily manufacturable design and fast solution of problems.

  20. Sinterability of Zirconia Top Coat of Investment Mold for Ti Alloy

    Institute of Scientific and Technical Information of China (English)


    In this paper, zirconia is used as top mold material for Ti investment casting. Top mold samples are made by proper mold building technology. The effect of different sintering temperature on chemical composition, microstructure and residual bending strength of the top mold sample is studied. The volume and homogeneity of the air holes in the top mold are determined by sintering temperature, and finally determined the residual bending strength of the mold sample was determined.

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


    J. Tepić; V. Todić; Lukić, D.; Milošević, M.; Borojević, S.


    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-...

  2. Optimization of Mold Yield in MultiCavity Sand Castings (United States)

    Shinde, Vasudev D.; Joshi, Durgesh; Ravi, B.; Narasimhan, K.


    The productivity of ductile iron foundries engaging in mass production of castings for the automobile and other engineering sectors depends on the number of cavities per mold. A denser packing of cavities, however, results in slower heat transfer from adjacent cavities, leading to delayed solidification, possible shrinkage defects, and lower mechanical properties. In this article, we propose a methodology to optimize mold yield by selecting the correct combination of the mold box size and the number of cavities based on solidification time and mold temperature. Simulation studies were carried out by modeling solid and hollow cube castings with different values of cavity-wall gap and finding the minimum value of the gap beyond which there is no change in casting solidification time. Then double-cavity molds were modeled with different values of cavity-cavity gap, and simulated to find the minimum value of gap. The simulation results were verified by melting and pouring ductile iron in green sand molds instrumented with thermocouples, and recording the temperature in mold at predetermined locations. The proposed approach can be employed to generate a technological database of minimum gaps for various combinations of part geometry, metal and process, which will be very useful to optimize the mold cavity layouts.

  3. Vacuum Infusion Molding Process (Part 2 VIMP Based on Grooves)

    Institute of Scientific and Technical Information of China (English)

    ZHU Ying-dan; DENG Jing-lan; WANG Ji-hui; TAN Hua


    The optimal parameters for flow grooves and supply grooves were determined by a series of experiments , and the influences of various molding conditions on the mold filling process were analyzed. Furthermore ,the whole VIMP procedure based on grooves was introduced in detail taking the manufacture of a sandwich panel as an example.

  4. A fabrication method of microneedle molds with controlled microstructures. (United States)

    Wang, Qi Lei; Zhu, Dan Dan; Chen, Yang; Guo, Xin Dong


    Microneedle (MN) offers an attractive, painless and minimally invasive approach for transdermal drug delivery. Polymer microneedles are normally fabricated by using the micromolding method employing a MN mold, which is suitable for mass production due to high production efficiency and repeat-using of the mold. Most of the MN molds are prepared by pouring sylgard polymer over a MN master to make an inverse one after curing, which is limited in optimizing or controlling the MN structures and failing to keep the sharpness of MNs. In this work we describe a fabrication method of MN mold with controlled microstructures, which is meaningful for the fabrication of polymer MNs with different geometries. Laser micro-machining method was employed to drill on the surface of PDMS sheets to obtain MN molds. In the fabrication process, the microstructures of MN molds are precisely controlled by changing laser parameters and imported patterns. The MNs prepared from these molds are sharp enough to penetrate the skin. This scalable MN mold fabrication method is helpful for future applications of MNs.

  5. Two component micro injection molding for MID fabrication

    DEFF Research Database (Denmark)

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


    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 ...


    Although molds have demonstrated the ability to induce allergic asthma-like responses in mouse models, their role in human disease is unclear. This study was undertaken to provide insight into the prevalence of human IgE-reactivity and identify the target mold protein(s). The st...


    Molds have been associated with various health effects including asthma, but their role in induction of asthma is unclear. However, the presence of mold-specific IgE indicates their capacity to induce allergic responses and possibly exacerbate asthma symptoms. This study was und...

  8. 21 CFR 177.2410 - Phenolic resins in molded articles. (United States)


    ... 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...

  9. Effect of processing conditions on shrinkage in injection molding

    NARCIS (Netherlands)

    Jansen, K.M.B.; Dijk, van D.J.; Husselman, M.H.


    A systematic study on the effect of processing conditions on mold shrinkage was undertaken for seven common thermoplastic polymers. It turned out that the holding pressure was always the key parameter. The effect of the melt temperature is slightly less important. Injection velocity and mold tempera

  10. Multi-height structures in injection molded polymer

    DEFF Research Database (Denmark)

    Andersen, Nis Korsgaard; Taboryski, Rafael J.


    We present the fabrication process for injection molded multi-height surface structures for studies of wetting behavior. We adapt the design of super hydrophobic structures to the fabrication constrictions imposed by industrial injection molding. This is important since many super hydrophobic sur...

  11. Taxonomic re-evaluation of black koji molds

    NARCIS (Netherlands)

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


    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 Oki

  12. Cross-linked agarose for separation of low molecular weight natural products in hydrophilic interaction liquid chromatography. (United States)

    Tan, Tianwei; Su, Zhi-Guo; Gu, Ming; Xu, Jun; Janson, Jan-Christer


    Following its market introduction in 1982, the cross-linked 12% agarose gel media Superose 12 has become widely known as a tool for size exclusion chromatography of proteins and other biological macromolecules. In this review it is shown that, when appropriate mobile phases are used, Superose possesses adsorption properties similar to that of traditional media for hydrophilic interaction liquid chromatography (HILIC). This is illustrated by the separation and purification of low molecular weight compounds such as polyphenols including active components of traditional Chinese medicinal herbs and green tea. Structural features of the cross-linked agarose that likely cause the observed adsorption effects are discussed as well. These are identified as being primarily ether bonds acting as strong hydrogen bond acceptors as well as hydrophobic residues originating from the cross-linking reagents.

  13. Preparation of a novel pH optical sensor using orange (II) based on agarose membrane as support. (United States)

    Heydari, Rouhollah; Hosseini, Mohammad; Amraei, Ahmadreza; Mohammadzadeh, Ali


    A novel and cost effective optical pH sensor was prepared using covalent immobilization of orange (II) indicator on the agarose membrane as solid support. The fabricated optical sensor was fixed into a sample holder of a spectrophotometer instrument for pH monitoring. Variables affecting sensor performance including pH of dye bonding to agarose membrane and dye concentration were optimized. The sensor responds to the pH changes in the range of 3.0-10.0 with a response time of 2.0 min and appropriate reproducibility (RSD ≤ 0.9%). No significant variation was observed on sensor response after increasing the ionic strength in the range of 0.0-0.5M of sodium chloride. Determination of pH using the proposed optical sensor is quick, simple, inexpensive, selective and sensitive in the pH range of 3.0-10.0.

  14. Standard Molded Composite Rocket Pyrogen Igniter - A progress report (United States)

    Lucy, M. H.


    The pyrogen igniter has the function to furnish a controlled, high temperature, high pressure gas to ignite solid propellant surfaces in a rocket motor. Present pyrogens consist of numerous inert components. The Standard Molded Pyrogen Igniter (SMPI) consists of three basic parts, a cap with several integrally molded features, an ignition pellet retainer plate, and a tube with additional integrally molded features. A description is presented of an investigation which indicates that the SMPI concept is a viable approach to the design and manufacture of pyrogen igniters for solid propellant rocket motors. For some applications, combining the structural and thermal properties of molded composites can result in the manufacture of lighter assemblies at considerable cost reduction. It is demonstrated that high strength, thin walled tubes with high length to diameter ratios can be fabricated from reinforced plastic molding compound using the displacement compression process.


    Energy Technology Data Exchange (ETDEWEB)

    Post, Brian K [ORNL; Love, Lonnie J [ORNL; Duty, Chad [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Vaidya, Uday [University of Tennessee, Knoxville (UTK); Pipes, R. Byron [Purdue University; Kunc, Vlastimil [ORNL


    Oak Ridge National Laboratory s Big Area Additive Manufacturing (BAAM) technology permits the rapid production of thermoplastic composite molds using a carbon fiber filled Acrylonitrile-Butadiene-Styrene (ABS) thermoplastic. Demonstration tools (i.e. 0.965 m X 0.559 m X 0.152 m) for composite part fabrication have been printed, coated, and finished with a traditional tooling gel. We present validation results demonstrating the stability of thermoplastic printed molds for room temperature Vacuum Assisted Resin Transfer Molding (VARTM) processes. Arkema s Elium thermoplastic resin was investigated with a variety of reinforcement materials. Experimental results include dimensional characterization of the tool surface using laser scanning technique following demolding of 10 parts. Thermoplastic composite molds offer rapid production compared to traditionally built thermoset molds in that near-net deposition allows direct digital production of the net geometry at production rate of 45 kg/hr.

  16. Injection molding of bushes made of tribological PEEK composites

    Directory of Open Access Journals (Sweden)


    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.

  17. Injection-molded nanocomposites and materials based on wheat gluten. (United States)

    Cho, S-W; Gällstedt, M; Johansson, E; Hedenqvist, M S


    This is, to our knowledge, the first study of the injection molding of materials where wheat gluten (WG) is the main component. In addition to a plasticizer (glycerol), 5 wt.% natural montmorillonite clay was added. X-ray indicated intercalated clay and transmission electron microscopy indicated locally good clay platelet dispersion. Prior to feeding into the injection molder, the material was first compression molded into plates and pelletized. The filling of the circular mold via the central gate was characterized by a divergent flow yielding, in general, a stronger and stiffer material in the circumferential direction. It was observed that 20-30 wt.% glycerol yielded the best combination of processability and mechanical properties. The clay yielded improved processability, plate homogeneity and tensile stiffness. IR spectroscopy and protein solubility indicated that the injection molding process yielded a highly aggregated structure. The overall conclusion was that injection molding is a very promising method for producing WG objects.

  18. Mold Flora of Traditional Cheeses Produced in Turkey

    Directory of Open Access Journals (Sweden)

    Musa Yalman


    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.

  19. The Facility and Process Technics of Polyethylene Rotational Molding

    Institute of Scientific and Technical Information of China (English)

    LI; BaiShun


    1. Introduction Rotational molding is the process by which hollow plastic parts are formed. It mainly processes the product which Injection molding and Blow molding can not process medium-sized, large-sized and super large-sized plastic parts. The technics may turn out a tub, dustbin, stock tank, sailboat.  The research institute of Lanzhou introduces a suit of RS-16 Rotational Molding Machine from Germany Reinhadt Co. on 1990. It mainly put up experiment and smallscale production. RS-16 rotational molding machine is a single arm and di-axial equipment. It is consisting of a gas heated sintering oven, cooling chamber, mouldcarrying carriage and a controlling unit.  ……

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

  1. In Situ Observations of Thermoreversible Gelation and Phase Separation of Agarose and Methylcellulose Solutions under High Pressure. (United States)

    Kometani, Noritsugu; Tanabe, Masahiro; Su, Lei; Yang, Kun; Nishinari, Katsuyoshi


    Thermoreversible sol-gel transitions of agarose and methylcellulose (MC) aqueous solutions on isobaric cooling or heating under high pressure up to 400 MPa have been investigated by in situ observations of optical transmittance and falling-ball experiments. For agarose, which undergoes the gelation on cooling, the application of pressure caused a gradual rise in the cloud-point temperature over the whole pressure range examined, which is almost consistent with the pressure dependence of gelling temperature estimated by falling-ball experiments, suggesting that agarose gel is stabilized by compression and that the gelation occurs nearly in parallel with phase separation under ambient and high-pressure conditions. For MC, which undergoes the gelation on heating, the cloud-point temperature showed a slight rise with an initial elevation of pressure up to ∼150 MPa, whereas it showed a marked depression above 200 MPa. In contrast, the gelling temperature of MC, which is nearly identical to the cloud-point temperature at ambient pressure, showed a monotonous rise with increasing pressure up to 350 MPa, which means that MC undergoes phase separation prior to gelation on heating under high pressure above 200 MPa. Similar results were obtained for the melting process of MC gel on cooling. The unique behavior of the sol-gel transition of MC under high pressure has been interpreted in terms of the destruction of hydrophobic hydration by compression.

  2. Templated agarose scaffolds for the support of motor axon regeneration into sites of complete spinal cord transection. (United States)

    Gao, Mingyong; Lu, Paul; Bednark, Bridget; Lynam, Dan; Conner, James M; Sakamoto, Jeff; Tuszynski, Mark H


    Bioengineered scaffolds have the potential to support and guide injured axons after spinal cord injury, contributing to neural repair. In previous studies we have reported that templated agarose scaffolds can be fabricated into precise linear arrays and implanted into the partially injured spinal cord, organizing growth and enhancing the distance over which local spinal cord axons and ascending sensory axons extend into a lesion site. However, most human injuries are severe, sparing only thin rims of spinal cord tissue in the margins of a lesion site. Accordingly, in the present study we examined whether template agarose scaffolds seeded with bone marrow stromal cells secreting Brain-Derived Neurotrophic Factor (BDNF) would support regeneration into severe, complete spinal cord transection sites. Moreover, we tested responses of motor axon populations originating from the brainstem. We find that templated agarose scaffolds support motor axon regeneration into a severe spinal cord injury model and organize axons into fascicles of highly linear configuration. BDNF significantly enhances axonal growth. Collectively, these findings support the feasibility of scaffold implantation for enhancing central regeneration after even severe central nervous system injury.

  3. Public health and economic impact of dampness and mold

    Energy Technology Data Exchange (ETDEWEB)

    Mudarri, David; Fisk, William J.


    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.


    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar


    Full Text Available Nowadays injection molding is probably the most important method of Processing of consumer and industrial goods, and is performed everywhere in the world. The developing of injection molding becomes a competition from day to day. This Process now integrated with computer control make the production better in quality and Better quantity. The trends of producing a plastics product in injection molding industries are recently changing from traditional method to using the FEA analysis. For injection molding industries, time and cost is very important aspects to consider because these two aspectswill directly related to the profits at a company. The next issue toconsider, to get the best parameter for the injection molding process, plastics has been waste. Through the experiment, operator will use large amount of plastics material to get the possibly parameters to setup the machine.To produce the parts with better quality and quantity these molding defects are the major obstacles in achieving the targets with quality & quantity. Various defects like Short shot, colour streaks and low productivity rates are associated with the material mixing and feeding as molded plastics are often a blend of two or more materials. Colors (master batch and other additives are often mixed (blended with the raw plastic material prior to the molding process in molding plants. So it is very necessary to work out auto blending and auto feeding of plasticgranules to the machine hopper. This paper will cover the studyof automatic blending unit & central conveying system for plasticgranule feeding to machine & will help in optimizing the injection molding process.

  5. Compliance with Segment Disclosure Initiatives

    DEFF Research Database (Denmark)

    Arya, Anil; Frimor, Hans; Mittendorf, Brian


    Regulatory oversight of capital markets has intensified in recent years, with a particular emphasis on expanding financial transparency. A notable instance is efforts by the Financial Accounting Standards Board that push firms to identify and report performance of individual business units...... (segments). This paper seeks to address short-run and long-run consequences of stringent enforcement of and uniform compliance with these segment disclosure standards. To do so, we develop a parsimonious model wherein a regulatory agency promulgates disclosure standards and either permits voluntary...... compliance or mandates strict compliance from firms. Under voluntary compliance, a firm is able to credibly withhold individual segment information from its competitors by disclosing data only at the aggregate firm level. Consistent with regulatory hopes, we show that mandatory compliance enhances welfare...

  6. Compliance with physical exercise

    DEFF Research Database (Denmark)

    Gram, Anne Sofie; Bønnelycke, Julie; Rosenkilde Larsen, Mads


    Aims: Sixty-one healthy, sedentary, moderately overweight young men participated in a randomised controlled trial to examine the effects of two different doses of endurance exercise on health behaviour and exercise compliance. Methods: Participants were randomised to a sedentary control group......, a moderate (MOD; 300 kcal/day) or a high-dose (HIGH; 600 kcal/day) endurance exercise group for 12 weeks. A sub-set of the subjects were interviewed using pre-determined, qualitative questions to elucidate physical activity and health behaviour. In combination with the Theory of Planned Behaviour (TPB...... improved various metabolic health parameters. The MOD group was untroubled by the exercise load and had a positive attitude towards exercise. The HIGH group expressed increased fatigue, less positivity and perceived exercise as time-consuming. The MOD group described themselves as more energetic...

  7. Specific mold filling characteristics of highly filled phenolic injection molding compounds


    Scheffler, Thomas; Englich, Sascha; Gehde, Michael


    Thermosets show excellent mechanical properties and chemical resistance (for most automotive fluids) even at high temperatures up to 300 °C. Furthermore they can be highly efficient processed by injection molding. So they should be particularly suited for e.g. under the bonnet applications. However, the reality shows that thermosets are, except fiber reinforced composites, heavily underrepresented in technical applications. E.g. thermosetting components only account 0,2 % to a vehicle’s weigh...

  8. Chondrocyte Morphology in Stiff and Soft Agarose Gels and the Influence of Fetal Calf Serum. (United States)

    Karim, Asima; Hall, Andrew C


    Changes to chondrocyte volume/morphology may have deleterious effects on extracellular matrix (ECM) metabolism potentially leading to cartilage deterioration and osteoarthritis (OA). The factors controlling chondrocyte properties are poorly understood, however, pericellular matrix (PCM) weakening may be involved. We have studied the density, volume, morphology, and clustering of cultured bovine articular chondrocytes within stiff (2% w/v) and soft (0.2% w/v) three-dimensional agarose gels. Gels with encapsulated chondrocytes were cultured in Dulbecco's Modified Eagle's Medium (DMEM; fetal calf serum (FCS) 1-10%;380 mOsm) for up to 7 days. Chondrocytes were fluorescently labeled after 1, 3, and 7 days with 5-chloromethylfluorescein-diacetate (CMFDA) and propidium iodide (PI) or 1,5-bis{[2-(di-methylamino)ethyl]amino}-4,8-dihydroxyanthracene-9,10-dione (DRAQ5) to identify cytoplasmic space or DNA and imaged by confocal laser scanning microscopy (CLSM). Chondrocyte density, volume, morphology, and clustering were quantified using Volocity™ software. In stiff gels after 7 d with 10% FCS, chondrocyte density remained unaffected and morphology was relatively normal with occasional cytoplasmic processes. However, in soft gels by day 1, chondrocyte volume increased (P = 0.0058) and by day 7, density increased (P = 0.0080), along with the percentage of chondrocytes of abnormal morphology (P stiff gels. FCS exacerbated changes to density (P stiffness and/or increased FCS concentrations promoted chondrocyte proliferation and clustering, increased cell volume, and stimulated abnormal morphology, producing similar changes to those occurring in OA. The increased penetration of factors in FCS into soft gels may be important in the development of these abnormal chondrocyte properties. J. Cell. Physiol. 232: 1041-1052, 2017. © 2016 Wiley Periodicals, Inc.

  9. Glyoxyl-disulfide agarose: a tailor-made support for site-directed rigidification of proteins. (United States)

    Godoy, Cesar A; de las Rivas, Blanca; Grazú, Valeria; Montes, Tamara; Guisán, José Manuel; López-Gallego, Fernando


    A new strategy has been developed for site-directed immobilization/rigidification of genetically modified enzymes through multipoint covalent attachment on bifunctional disulfide-glyoxyl supports. Here the mechanism is described as a two-step immobilization/rigidification protocol where the enzyme is directly immobilized by thiol-disulfide exchange between the β-thiol of the single genetically introduced cysteine and the few disulfide groups presented on the support surface (3 μmol/g). Afterward, the enzyme is uniquely rigidified by multipoint covalent attachment (MCA) between the lysine residues in the vicinity of the introduced cysteine and the many glyoxyl groups (220 μmol/g) on the support surface. Both site-directed immobilization and rigidification have been possible only on these novel bifunctional supports. In fact, this technology has made possible to elucidate the protein regions where rigidification by MCA promoted higher protein stabilizations. Hence, rigidification of vicinity of position 333 from lipase 2 from Geobacillus thermocatenulatus (BTL2) promoted a stabilization factor of 33 regarding the unipunctual site-directed immobilized derivative. In the same context, rigidification of penicillin G acylase from E. coli (PGA) through position β201 resulted in a stabilization factor of 1069. Remarkably, when PGA was site-directed rigidified through that position, it presented a half-life time of 140 h under 60% (v/v) of dioxane and 4 °C, meaning a derivative eight times more stable than the PGA randomly immobilized on glyoxyl-disulfide agarose. Herein we have opened a new scenario to optimize the stabilization of proteins via multipoint covalent immobilization, which may represent a breakthrough in tailor-made tridimensional rigidification of proteins.

  10. IPN hydrogel nanocomposites based on agarose and ZnO with antifouling and bactericidal properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingjing, E-mail:; Hu, Hongkai; Yang, Zhonglin; Wei, Jun; Li, Juan


    Nanocomposite hydrogels with interpenetrating polymer network (IPN) structure based on poly(ethylene glycol) methyl ether methacrylate modified ZnO (ZnO-PEGMA) and 4-azidobenzoic agarose (AG-N{sub 3}) were prepared by a one-pot strategy under UV irradiation. The hydrogels exhibited a highly macroporous spongelike structure, and the pore size decreased with the increase of the ZnO-PEGMA content. Due to the entanglement and favorable interactions between the two crosslinked networks, the IPN hydrogels exhibited excellent mechanical strength and light transmittance. The maximum compressive and tensile strengths of the IPN hydrogels reached 24.8 and 1.98 MPa respectively. The transparent IPN hydrogels transmitted more than 85% of visible light at all wavelengths (400–800 nm). The IPN hydrogels exhibited anti-adhesive property towards Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), and the bactericidal activity increased with the ZnO-PEGMA content. The incorporation of ZnO-PEGMA did not reduce the biocompatibility of the IPN hydrogels and all the IPN nanocomposites showed negligible cytotoxicity. The present study not only provided a facile method for preparing hydrogel nanocomposites with IPN structure but also developed a new hydrogel material which might be an excellent candidate for wound dressings. - Highlights: • IPN hydrogel nanocomposites were prepared by a one-pot strategy. • The maximum compressive and tensile strengths reached 24.8 and 1.98 MPa. • IPN hydrogels displayed excellent antibacterial activity and cytocompatibility. • This study provided a facile method for preparing IPN hydrogel nanocomposites.

  11. Automatic polishing process of plastic injection molds on a 5-axis milling center

    CERN Document Server

    Pessoles, Xavier; 10.1016/j.jmatprotec.2008.08.034


    The plastic injection mold manufacturing process includes polishing operations when surface roughness is critical or mirror effect is required to produce transparent parts. This polishing operation is mainly carried out manually by skilled workers of subcontractor companies. In this paper, we propose an automatic polishing technique on a 5-axis milling center in order to use the same means of production from machining to polishing and reduce the costs. We develop special algorithms to compute 5-axis cutter locations on free-form cavities in order to imitate the skills of the workers. These are based on both filling curves and trochoidal curves. The polishing force is ensured by the compliance of the passive tool itself and set-up by calibration between displacement and force based on a force sensor. The compliance of the tool helps to avoid kinematical error effects on the part during 5-axis tool movements. The effectiveness of the method in terms of the surface roughness quality and the simplicity of impleme...

  12. Star Mapping with Slime Mold Physarum Polycephalum (United States)

    Mihklepp, M.; Domnitch, E.; Gelfand, D.; Foing, B. H.; van der Heide, E.


    Human curiosity and exploration towards outer space has led to many fantastic inventions and given way to alternative scenarios about the origins of life. In the Space Science in the Arts course together with ESTEC with support from ILEWG. I got interested about unicellular slime mold Physarum polycephalum. There has been and still is a lot of research on Physarum polycephalum. This brainless eucaryotic microbe has its smartness and external memory strategies. Physarum can navigate through a maze made of agar using the shortest route possible when two pieces of food are placed at two separate exits of the maze. It can build efficient networks - Physarum created network similar to the existing Tokyo train system. It is being used to control a robot, in USB-sensor and in sound synthesis. Right now there is a lot of research about using Physarum in bio-computing.


    Directory of Open Access Journals (Sweden)

    David Garcia


    Full Text Available This work follows the general framework of polymer injection moulding simulation whose objectives are the mastering of the injection moulding process. The models of numerical simulation make it possible to predict the propagation of the molten polymer during the filling phase from the positioning of one point of injection or more. The objective of this paper is to propose a particular way to optimize the geometry of mold cavity in accordance with physical laws. A direct correlation is pointed out between geometric parameters issued from skeleton transformation and Hausdorff's distance and results provided by implementation of a classical model based on the Hele-Shaw equations which are currently used in the main computer codes of polymer injection.

  14. [Biological monitoring in the molding of plastics and rubbers]. (United States)

    Fustinoni, S; Campo, L; Cirla, A M; Cirla, P E; Cutugno, V; Lionetti, C; Martinotti, I; Mossini, E; Foà, V


    This survey was carried out in the molding of plastics and rubbers, in the "Professional Cancer Prevention Project" sponsored by the Lombardy region with the objective of developing and implementing protocols for evaluating exposure to carcinogens through the biological monitoring. The realities of molding the thermoplastic polymer ABS, rubber, and thermosetting plastics containing formaldehyde were examined. The carcinogenic substances identified in these processes were: 1,3-butadiene, acrylonitrile and styrene in molding ABS, polycyclic aromatic hydrocarbons (PAH) in molding rubber, and formaldehyde in molding the thermosetting plastics. Only for some of these substances biological indicators are available. The limited exposure to airborne chemicals in molding ABS and the intrinsic characteristics of biological indicators available for 1-3 butadiene have determined the non applicability of biological monitoring to this situation. The absence of a biological indicator of exposure to formaldehyde has made this situation not investigable. Exposure in the rubber molding was studied in 19 subjects applying the determination not metabolized PAH in urine. The levels of these indicators were similar to those measured in other groups of subjects without occupational exposure to PAH, confirming a low airborne contamination in this workplace.

  15. Thermomechanical Behavior in Continuous Bloom Casting with Different Mold Tapers

    Institute of Scientific and Technical Information of China (English)

    LUO Xin; CHEN Yong; SHEN Houfa


    A two-dimensional finite element model was used to analyze the thermal and mechanical behavior dunng solidification of the strand in a continuous bloom casting mold.The coupled heat transfer and defermation were analyzed to simulate the formation of the air gap between the mold and the strand.The model was used to investigate the influence of mold taper on the temperature and stress distributions in the strand.The results show that the air gap mainly forms around the strand corner,causing a hoRer and thinner solidifying shell in this region.The mold taper partially compensates for the strand shell shnnkage and reduces the infiuence of the air gap on the heat transfer.The mold taper compresses the shell and changes the stress state around the stmnd comer region.As the strand moves down into the mold,the mold constraint causes compressive stress beneath the comer surface.which reduces the hot tear that forms on the strand.

  16. Review of small aspheric glass lens molding technologies (United States)

    Yin, Shaohui; Jia, Hongpeng; Zhang, Guanhua; Chen, Fengjun; Zhu, Kejun


    Aspheric lens can eliminate spherical aberrations, coma, astigmatism, field distortions, and other adverse factors. This type of lens can also reduce the loss of light energy and obtain high-quality images and optical characteristics. The demand for aspheric lens has increased in recent years because of its advantageous use in the electronics industry, particularly for compact, portable devices and high-performance products. As an advanced manufacturing technology, the glass lens molding process has been recognized as a low-cost and high-efficiency manufacturing technology for machining small-diameter aspheric lens for industrial production. However, the residual stress and profile deviation of the glass lens are greatly affected by various key technologies for glass lens molding, including glass and mold-die material forming, mold-die machining, and lens molding. These key technical factors, which affect the quality of the glass lens molding process, are systematically discussed and reviewed to solve the existing technical bottlenecks and problems, as well as to predict the potential applicability of glass lens molding in the future.

  17. A New Type Machine of Mixing-molding for Polyblends

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan-sheng; LI Li; BIAN Hui-guang


    This paper introduces a new type machine for polyblends with excellent mixing capabilities of internal mixer and continuous molding character of extruder. The machine includes two functions -- mixing and extrusion molding that have been composed together by rational design, so a tandem production mode -- "batch + continuous" are opened up. The mathematical model of continuous mixing molding was established and verified availably by experimental research. The main physical mechanical property of vuicanizate, which had met national waterproof material standard, verified the machine practicability. The essential difference from other similar type machines is that this machine is not only suitable in producing granular and powder rubbers but also lumpish tablets.

  18. Desarrollo de moldes de prensado con recubrimientos antidesgaste


    Poyatos, A.; Tur, F.; Pérez, José Antonio; Rodríguez, Miguel A.


    [ES] El objetivo del presente trabajo ha sido el desarrollo de una nueva concepción de moldes de prensado para la industria del pavimento y revestimiento cerámicos. El empleo de recubrimientos con materiales compuestos metal-cerámica ha permitido, además de multiplicar la vida útil de los moldes por un factor entre 2 y 3 (1.000.000 – 1.500.000 ciclos de prensado), emplear aceros más económicos en la producción del molde, su reutilización, eliminar etapas de alto consumo energético, c...

  19. Development of Integrated Simulation System for Plastic Injection Molding

    Institute of Scientific and Technical Information of China (English)

    CHENGXue-wen; LIDe-qun; ZHOUHua-min


    Numerical simulation of injection molding have had success in predicting the behavior of polymer melt in extremely complicated geometries. Most of the current numerical solutions are based on finite-element/finite-difference/boundary-element/volume-control methods and the surface model. This paper discusses the development of an integrated CAE system for injection molding in detail, and presents the mathematics for numerical simulation of filling, packing,cooling, stress and warpage in injection molding. The developed system named as HsCAE3D is introduced at the end.

  20. The analysis of injection molding defects caused by gate vestiges

    Directory of Open Access Journals (Sweden)

    T. Tabi


    Full Text Available Issues of product safety are the most serious problems of an injection molded product due to their risk to human health. Such a safety problem can be the needle-shaped vestige at the gate zone of injection molded products, called a gate vestige. Only observations of the formation of gate vestiges can be found in the literature, but the processing parameters influencing their dimensions, especially their height have not been studied yet. Our goal was to study the effect of various injection molding processing parameters and gate constructions on gate vestige formation.

  1. Recent Developments and Trends in Powder Injection Molding

    Institute of Scientific and Technical Information of China (English)

    Hermina Wang


    Injection molding is a productive and widely used technology for shaping plastics. The use of this shaping technique to metal and ceramics powders is termed powder injection molding (PIM). This process combines a certain quantity of a polymer with a metallic or ceramic powder to form a feedstock that can be molded. After shaping, the polymeric binder is extracted and the powder is sintered. When proper powder size or/and its distribution are used, sintered densities of 95% or more, often to near-theoretical densities, are reached and the mechanical properties are, therefore, generally superior to those of traditional PM parts.

  2. Fabrication of micro gear wheels by micropowder injection molding

    Institute of Scientific and Technical Information of China (English)

    Haiqing Yin; Xuanhui Qu; Chengchang Jia


    The micropowder injection molding technology was investigated to fabricate the microsized gear wheels on a conventional injection molding machine. The feedstock comprised of carbonyl ferrum powder and a wax-based thermoplastic binder. Microinjection molding was fulfilled at about 423 K under 100 MPa. The heating system was applied to the die to improve the fluidity of the feedstock and subsequently the cooling system was used to enhance the strength of the green compacts after injection by decreasing the temperature of the die. The gear wheels were realized successfully with their addendum circle diameter ranging from 800 to 200 m and with the center hole as small as 60 μtm.

  3. Rapid and low-cost prototyping of medical devices using 3D printed molds for liquid injection molding. (United States)

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


    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.

  4. 40 CFR 63.5728 - What standards must I meet for closed molding resin operations? (United States)


    ... molding resin operations? 63.5728 Section 63.5728 Protection of Environment ENVIRONMENTAL PROTECTION... Standards for Closed Molding Resin Operations § 63.5728 What standards must I meet for closed molding resin operations? (a) If a resin application operation meets the definition of closed molding specified in §...

  5. The use of birefringence for predicting the stiffness of injection molded polycarbonate discs

    NARCIS (Netherlands)

    Neves, N.M.; Pouzada, A.S.; Voerman, J.H.D.; Powell, P.C.


    Polycarbonate discs were injection molded with different sets of molding conditions. The parameters studied were the flow rate, melt- and mold-temperature. The discs were subjected to three point support flexural tests. Those tests are specially intended for injection molded discs because of their i

  6. Mold Simulator Study on the Initial Solidification of Molten Steel Near the Corner of Continuous Casting Mold (United States)

    Lyu, Peisheng; Wang, Wanlin; Zhang, Haihui


    Corner cracks are one of the most widespread surface defects of continuous casting slabs, and they are especially severe for peritectic steels and low-alloy steels. Therefore, a clear understanding of molten steel initial solidification around mold corner would be of great importance for the inhibition of corner cracks. This paper has been conducted with the aim to elucidate this understanding, by using a novel mold simulator equipped with a right-angle copper mold. The responding temperatures and heat fluxes across the mold hot-face and corner were firstly calculated through a 2D-inverse heat conduction program mathematical model, and the results suggested that the cooling ability and the fluctuation of heat fluxes around the mold corner are stronger than those for mold hot-face. With the help of power spectral density analysis and fast Fourier transformation, the four characteristic signals of heat fluxes were discussed in this paper. Next, the relation between the thickness of solidified shell and solidification time was fitted with the solidification square root law; as a result, the average solidification factor bar{K} for the hot-face shell is 2.32 mm/s1/2, and it is 2.77 mm/s1/2 for the shell near-corner. For the same oscillation marks (OMs), it appeared that the OMs positions on the shell corner are lower than those on the shell hot-face along the casting direction, because the stronger shrinkage of shell at the corner allows the overflowing steel to penetrate deeper into the larger gap between the shell corner and mold, which is demonstrated through the heat transfer analysis and metallographic examination. Finally, the interrelation between shell profile, mold oscillation, variation rate of heat flux, high-frequency heat flux and high-frequency temperature was discussed for above two cases, and the results suggested that meniscus conditions (heat transfer and melt flow) around the mold corner are more unsteady.

  7. Mold Simulator Study on the Initial Solidification of Molten Steel Near the Corner of Continuous Casting Mold (United States)

    Lyu, Peisheng; Wang, Wanlin; Zhang, Haihui


    Corner cracks are one of the most widespread surface defects of continuous casting slabs, and they are especially severe for peritectic steels and low-alloy steels. Therefore, a clear understanding of molten steel initial solidification around mold corner would be of great importance for the inhibition of corner cracks. This paper has been conducted with the aim to elucidate this understanding, by using a novel mold simulator equipped with a right-angle copper mold. The responding temperatures and heat fluxes across the mold hot-face and corner were firstly calculated through a 2D-inverse heat conduction program mathematical model, and the results suggested that the cooling ability and the fluctuation of heat fluxes around the mold corner are stronger than those for mold hot-face. With the help of power spectral density analysis and fast Fourier transformation, the four characteristic signals of heat fluxes were discussed in this paper. Next, the relation between the thickness of solidified shell and solidification time was fitted with the solidification square root law; as a result, the average solidification factor bar{K} for the hot-face shell is 2.32 mm/s1/2, and it is 2.77 mm/s1/2 for the shell near-corner. For the same oscillation marks (OMs), it appeared that the OMs positions on the shell corner are lower than those on the shell hot-face along the casting direction, because the stronger shrinkage of shell at the corner allows the overflowing steel to penetrate deeper into the larger gap between the shell corner and mold, which is demonstrated through the heat transfer analysis and metallographic examination. Finally, the interrelation between shell profile, mold oscillation, variation rate of heat flux, high-frequency heat flux and high-frequency temperature was discussed for above two cases, and the results suggested that meniscus conditions (heat transfer and melt flow) around the mold corner are more unsteady.

  8. 10 CFR 434.604 - Compliance. (United States)


    ... energy consumption shall be measured at the building five foot line for all fuels. Energy consumed from... BUILDINGS Building Energy Compliance Alternative § 434.604 Compliance. 604.1 Compliance with this section is... 10 Energy 3 2010-01-01 2010-01-01 false Compliance. 434.604 Section 434.604 Energy DEPARTMENT...

  9. 40 CFR 469.11 - Compliance dates. (United States)


    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Compliance dates. 469.11 Section 469... Compliance dates. The compliance deadline for the BAT fluoride limitation shall be as soon as possible as... determined by the permit writer, but in no event later than July 1, 1984. The compliance date for PSES...

  10. 40 CFR 469.21 - Compliance dates. (United States)


    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Compliance dates. 469.21 Section 469....21 Compliance dates. The compliance date for the BAT fluoride limitation is as soon as possible as determined by the permit writer but in no event later than November 8, 1985. The compliance date for PSES...

  11. 14 CFR 26.49 - Compliance plan. (United States)


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Compliance plan. 26.49 Section 26.49... Data for Repairs and Alterations § 26.49 Compliance plan. (a) Compliance plan. Except for applicants... January 11, 2008, each person identified in §§ 26.43, 26.45, and 26.47, must submit a compliance...

  12. Air Compliance Complaint Database (ACCD) (United States)

    U.S. Environmental Protection Agency — THIS DATA ASSET NO LONGER ACTIVE: This is metadata documentation for the Region 7 Air Compliance Complaint Database (ACCD) which logs all air pollution complaints...

  13. Integrated Compliance Information System (ICIS) (United States)

    U.S. Environmental Protection Agency — The purpose of ICIS is to meet evolving Enforcement and Compliance business needs for EPA and State users by integrating information into a single integrated data...


    Directory of Open Access Journals (Sweden)

    Tomasz Jachowicz


    Full Text Available This paper presents the rotational molding process. The general principles of this polymer processing technology have been described. The main applications have been introduced and leading advantages and typical disadvantages of rotational molding process have been discussed. Based on the conducted experimental tests, the influence of changing one selected technological parameter, which characterized rotational molding process, on selected geometrical features of the polymer cast has been determined. Rotational mold’s speed around axes was changed and a thickness of cast walls has been measured. Laboratory test stand, processing properties of polymer, also test program and experimental test methodology have been described.

  15. A corneal mold to restore normal corneal dimensions. (United States)

    Swinger, C A; Kornmehl, E W; York, S; Forman, J S


    A corneal mold is described that provides an MK corneal button of normal thickness and curvature from an edematous, post-mortem button. The uniform, processed tissue can then be used for experimental refractive surgery.

  16. Brief Guide to Mold, Moisture, and Your Home (United States)

    Jump to main content US EPA United States Environmental Protection Agency Search Search Mold Share Facebook Twitter Google+ ... promptly and fix the water problem. It is important to dry water-damaged areas and items within ...

  17. Cork is used to make tooling patterns and molds (United States)

    Hoffman, F. J.


    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.

  18. Moldability Evaluation for Molded Parts Based on Fuzzy Reasoning

    Institute of Scientific and Technical Information of China (English)


    Moldability evaluation for molded parts, which is the basis of concurrent design, is a key design stage in injection molding design. By moldability evaluation the design problems can be found timely and an optimum plastic part design achieved. In this paper, a systematic methodology for moldability evaluation based on fuzzy logic is proposed. Firstly, fuzzy set modeling for six key design attributes of molded parts is carried out respectively. Secondly, on the basis of this, the relationship between fuzzy sets for design attributes and fuzzy sets for moldability is established by fuzzy rules that are based on domain experts' experience and knowledge. At last the integral moldability for molded parts is obtained through fuzzy reasoning. The neural network based fuzzy reasoning approach presented in this paper can improve fuzzy reasoning efficiency greatly, especially for system having a large number of rules and complicated membership functions. An example for moldability evaluation is given to show the feasibility of this proposed methodology.

  19. Residual stresses in injection molded shape memory polymer parts (United States)

    Katmer, Sukran; Esen, Huseyin; Karatas, Cetin


    Shape memory polymers (SMPs) are materials which have shape memory effect (SME). SME is a property which has the ability to change shape when induced by a stimulator such as temperature, moisture, pH, electric current, magnetic field, light, etc. A process, known as programming, is applied to SMP parts in order to alter them from their permanent shape to their temporary shape. In this study we investigated effects of injection molding and programming processes on residual stresses in molded thermoplastic polyurethane shape memory polymer, experimentally. The residual stresses were measured by layer removal method. The study shows that injection molding and programming process conditions have significantly influence on residual stresses in molded shape memory polyurethane parts.

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

    Energy Technology Data Exchange (ETDEWEB)

    Josh A. Salmond


    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.

  1. Cavity air flow behavior during filling in microinjection molding

    DEFF Research Database (Denmark)

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


    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...... mounted inside the mold. The influence of four μIM parameters, melt temperature, mold temperature, injection speed, and resistance to air evacuation, on two air flow-related output parameters is investigated by carrying out a design of experiment study. The results provide empirical evidences about...

  2. Smart plastic functionalization by nanoimprint and injection molding

    DEFF Research Database (Denmark)

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


    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...... the pattern. With this approach, we demonstrate the transfer of down to 140 nm wide holes on large areas with good structure fidelity on an injection molding steel insert. The durability of the sub-micrometer structures on the inserts have been investigated by running two production series of 102,000 and 73......,000 injection molded parts, respectively, on two different inserts and inspecting the inserts before and after the production series and the molded parts during the production series....

  3. Method and mold for casting thin metal objects

    Energy Technology Data Exchange (ETDEWEB)

    Pehrson, Brandon P; Moore, Alan F


    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.

  4. Hazardous Waste Compliance Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    Potter, G.L.; Holstein, K.A.


    The Hazardous Waste Compliance Program Plan (HWCPP) describes how the Rocky Flats Plant institutes a more effective waste management program designed to achieve and maintain strict adherence to the Resource Conservation and Recovery Act (RCRA) requirements. Emphasis is given to improve integration of line operations with programmatic and functional support activities necessary to achieve physical compliance to RCRA regulated equipment, facilities and operations at the floor level. This program focuses on specific activities occurring or which need to occur within buildings containing RCRA regulated units and activities. The plan describes a new approach to achieving and maintaining compliance. This approach concentrates authority and accountability for compliance with the line operating personnel, with support provided from the programmatic functions. This approach requires a higher degree of integration and coordination between operating and program support organizations. The principal changes in emphases are; (1) increased line operations involvement, knowledge and accountability in compliance activities, (2) improved management systems to identify, correct and/or avoid deficiencies and (3) enhanced management attention and employee awareness of compliance related matters.

  5. Stabilization of a raw starch digesting amylase from Aspergillus carbonarius via immobilization on activated and non-activated agarose gel. (United States)

    Nwagu, Tochukwu N; Okolo, Bartho N; Aoyagi, Hideki


    Applications of raw starch digesting amylases (RSDAs) are limited due to instability, product inhibition of enzyme and contamination. RSDA from Aspergillus carbonarius was stabilized through immobilization on agarose gel by adsorption, spontaneous crosslinking and conjugation using glycidol, glutaraldehyde or polyglutaraldehyde. Effects of immobilization on kinetics, catalytic, storage and operational stability of immobilized enzyme were evaluated. Polyglutaraldehyde activated agarose RSDA (PGAg-RSDA) gave the highest immobilization yield (100%) with expressed activity of 86.7% while that of glycidol activated RSDA (GlyAg-RSDA) was 80.4%. A shift in pH from optimum of 5 for the soluble enzyme to 6 for RSDA adsorbed on agarose followed by crosslinking with glutaraldehyde (AgRSDA-CROSS) and simultaneous adsorption and crosslinking (AgRSDA-RET), and pH 7 for PGAg-RSDA was seen. PGAg-RSDA and AgRSDA-CROSS were most pH stable and retained over 82% of their activities between pH 3.5 and 9 compared to 59% for the soluble enzyme. Thermoinactivation studies showed that immobilized RSDAs with the exception of GAg-RSDA retained over 90% of their activities at 60°C for 120 min while soluble enzyme retained only 76% activity under the same condition. AgRSDA-CROSS, PGAg-RSDA, Gly-RSDA and GAg-RSDA retained approximately 100% of their activities after 30 days storage at 4°C. GlyAg-RSDA retained 99.6%, PGAg-RSDA 94%, AgRSDA-CROSS 90%, GAg-RSDA 86.5% and Ag-RSDA-RET 80% activity after 10 batch reactions. Immobilization stabilized RSDA and permits processing at higher temperatures to reduce contamination.

  6. 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)


    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.

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

    DEFF Research Database (Denmark)

    Tanzi, Simone; Matteucci, Marco; Christiansen, Thomas Lehrmann;


    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...... the injection-molded polymer device were in good agreement with data obtained from the commercial system....

  8. Bioprospection of yeasts as biocontrol agents against phytopathogenic molds

    Directory of Open Access Journals (Sweden)

    Márcia Maria Rosa-Magri


    Full Text Available Yeasts isolated from sugar cane and maize rhizosphere, leaves and stalks were screened against the phytopathogenic molds Colletotrichum sublineolum and Colletotrichum graminicola, both causal agents of the anthracnose disease in sorghum and maize, respectively. Strains identified as Torulaspora globosa and Candida intermedia were able to inhibit the mold growth, with the first species also exhibiting killer activity. No previous report on the application and potentiality of these yeasts as biocontrol agents were found neither the killer phenotype in Torulaspora globosa.

  9. Bioprospection of yeasts as biocontrol agents against phytopathogenic molds


    Márcia Maria Rosa-Magri; Sâmia Maria Tauk-Tornisielo; Sandra Regina Ceccato-Antonini


    Yeasts isolated from sugar cane and maize rhizosphere, leaves and stalks were screened against the phytopathogenic molds Colletotrichum sublineolum and Colletotrichum graminicola, both causal agents of the anthracnose disease in sorghum and maize, respectively. Strains identified as Torulaspora globosa and Candida intermedia were able to inhibit the mold growth, with the first species also exhibiting killer activity. No previous report on the application and potentiality of these yeasts as bi...

  10. The Simulation and Optimization of Aspheric Plastic Lens Injection Molding

    Institute of Scientific and Technical Information of China (English)

    WEN Jialing; WEN Pengfei


    For the purpose of reducing the volumetric shrinkage and volumetric shrinkage variation, the process in injection molding of aspheric plastic lens was simulated, and several process parameters which include holding pressure, melt temperature, mold temperature, fill time, holding pressure time and cooling time were optimized by using an orthogonal experimental design method. Finally, the optimum process parameters and the influence degree of process parameters on the average volumetric shrinkage and the volumetric shrinkage variation are obtained.

  11. Material flow data for numerical simulation of powder injection molding (United States)

    Duretek, I.; Holzer, C.


    The powder injection molding (PIM) process is a cost efficient and important net-shape manufacturing process that is not completely understood. For the application of simulation programs for the powder injection molding process, apart from suitable physical models, exact material data and in particular knowledge of the flow behavior are essential in order to get precise numerical results. The flow processes of highly filled polymers are complex. Occurring effects are very hard to separate, like shear flow with yield stress, wall slip, elastic effects, etc. Furthermore, the occurrence of phase separation due to the multi-phase composition of compounds is quite probable. In this work, the flow behavior of a 316L stainless steel feedstock for powder injection molding was investigated. Additionally, the influence of pre-shearing on the flow behavior of PIM-feedstocks under practical conditions was examined and evaluated by a special PIM injection molding machine rheometer. In order to have a better understanding of key factors of PIM during the injection step, 3D non-isothermal numerical simulations were conducted with a commercial injection molding simulation software using experimental feedstock properties. The simulation results were compared with the experimental results. The mold filling studies amply illustrate the effect of mold temperature on the filling behavior during the mold filling stage. Moreover, the rheological measurements showed that at low shear rates no zero shear viscosity was observed, but instead the viscosity further increased strongly. This flow behavior could be described with the Cross-WLF approach with Herschel-Bulkley extension very well.

  12. CAE for Injection Molding — Past, Present and the Future (United States)

    Wang, Kuo K.


    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

  13. Localized rapid heating process for precision chalcogenide glass molding (United States)

    Li, Hui; He, Peng; Yu, Jianfeng; Lee, L. James; Yi, Allen Y.


    Precision glass molding is an important process for high volume optical fabrication. However, conventional glass molding is a bulk heating process that usually requires a long thermal cycle, where molding assembly and other mechanical parts are heated and cooled together. This often causes low efficiency and other heating and cooling related problems, such as large thermal expansion in both the molds and molded optics. To cope with this issue, we developed a localized rapid heating process to effectively heat only very small part of the glass. This localized rapid heating study utilized a fused silica wafer coated with a thin graphene layer to heat only the surface of the glass. The graphene coating functions as an electrical resistant heater when a power source was applied across the thin film coating, generating heat on and near the coating. The feasibility of this process was validated by both experiments and numerical simulation. To demonstrate the advantages of the localized rapid heating, both localized rapid heating process and bulk heating process were performed and carefully compared. The uniformity and quality of the molded sample by localized rapid heating process was also demonstrated. In summary, localized rapid heating process by using graphene coated fused silica wafer was characterized and can be readily implemented in replication of micro scale chalcogenide glasses. A fused silica wafer coated with a thin graphene layer was utilized for localized rapid heating only the surface of the glass. The graphene coating functions as an electrical resistant heater when a power source was applied across the thin film coating, generating high temperature on and near the coating. This process is fast and efficient since only interested areas are heated without affecting the entire glass substrate or the mold assembly. The uniformity and quality of the molded sample by localized rapid heating process was demonstrated by comparing both localized rapid heating

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

    Directory of Open Access Journals (Sweden)

    Chinmay Naphade


    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.

  15. Frequency of Mold Allergens in Allergic Rhinitis Patients

    Directory of Open Access Journals (Sweden)

    Bonyadi, MR. (PhD


    Full Text Available Background and Objective: Allergic rhinitis can be stimulated by several allergens. Molds are among these allergens and it is important to assess their frequency in different geographic area. Hence, we aimed at determining the frequency of mold allergens in allergic rhinitis patients referred to specialized clinics of Tabriz Imam Reza hospital, 2011. Material and Methods: This cross-sectional study was conducted on the serums of 90 rhinitis patients diagnosed by specialized physician. Using Immunoblotting method, the level of specific IgE against four molds including Penicillium, Aspergillus, Alternaria and Cladosporium were investigated. Results: Of 90 Patients, 40 were men (44.4% and 50 were women (55.6%. The participants were between 6 to 53 years and the most were 28-31years. The allergy was related to Penicillium (3.3%, Aspergillus (5.6%, Alternaria (13.3% and Cladosporium (4.4%. There was a significant statistical relation between age and allergic rhinitis to Alternaria (P=0.011. Conclusion: Molds can grow and proliferate in very humid environments. Because of low humidity climate in Tabriz (in the northwest of Iran, allergy to molds is relatively low in this region. Key words: Rhinitis Allergic; Mold; Allergy

  16. Precision glass molding of high-resolution diffractive optical elements (United States)

    Prater, Karin; Dukwen, Julia; Scharf, Toralf; Herzig, Hans P.; Plöger, Sven; Hermerschmidt, Andreas


    The demand of high resolution diffractive optical elements (DOE) is growing. Smaller critical dimensions allow higher deflection angles and can fulfill more demanding requirements, which can only be met by using electron-beam lithography. Replication techniques are more economical, since the high cost of the master can be distributed among a larger number of replicas. The lack of a suitable mold material for precision glass molding has so far prevented an industrial use. Glassy Carbon (GC) offers a high mechanical strength and high thermal strength. No anti-adhesion coatings are required in molding processes. This is clearly an advantage for high resolution, high aspect ratio microstructures, where a coating with a thickness between 10 nm and 200 nm would cause a noticeable rounding of the features. Electron-beam lithography was used to fabricate GC molds with highest precision and feature sizes from 250 nm to 2 μm. The master stamps were used for precision glass molding of a low Tg glass L-BAL42 from OHARA. The profile of the replicated glass is compared to the mold with the help of SEM images. This allows discussion of the max. aspect-ratio and min. feature size. To characterize optical performances, beamsplitting elements are fabricated and their characteristics were investigated, which are in excellent agreement to theory.

  17. Development of mold for biodegradable materials

    Energy Technology Data Exchange (ETDEWEB)

    Japitana, F.H.; Jabrica, A.M. [Metals Industry Research and Develeopment Center, Manila (Philippines). Dept. of Science and Technology; Komatsu, M. [Komatsu Consulting Engineer Office, Iwaki City, Fukushima (Japan); Takeuchi, Y. [Osaka Univ., Osaka (Japan). Dept. of Mechanical Engineering


    The improper disposal of non-biodegradable plastics adversely affect global environmental factors, principles of sustainability, industrial ecology and ecoefficiency. Therefore, a new generation of bio-based polymeric products has been developed. These polylactides (PLA), cellulose esters, starch plastics and polyhydroxyalkanoates (PHAs) are made from renewable natural resources and are biodegradable. They meet environmental conditions and can compete with their petrochemical counterparts. Among them, PLA is particularly attractive as a sustainable alternative to synthetic polymers and a potential candidate for the fabrication of biocomposites. Certain blends have proved successful in medical implants, sutures and drug delivery systems because of their capacity to dissolve away with time. However, widespread use of PLA is limited because of cost. Biodegradable plastic products are currently 6 to 10 times more expensive than traditional plastics. Environmentalists argue that the cheaper price of traditional plastics does not reflect their true cost when their impact is considered. This paper presented a solution to reduce the production cost of biodegradable plastics. In particular, it described a newly developed plastic injection mold for biodegradable materials which can produce a scrapless product. The system reduces processing time because it is not necessary to remove any gating or runners after the injection process. Takeout robots ensure that the quality of the product is maintained. 12 figs.

  18. Determination of heat transfer coefficients at the polymer-mold-interface for injection molding simulation by means of calorimetry (United States)

    Stricker, M.; Steinbichler, G.


    Appropriate modeling of heat transfer from the polymer material to the injection mold is essential to achieve accurate simulation results. The heat transfer is commonly modeled using convective heat transfer and applying heat transfer coefficients (HTC) to the polymer-mold-interface. The set HTC has an influence on the results for filling pressure, cooling performance and shrinkage, among others. The current paper, presents a new strategy to measure HTC in injection molding experiments using Newtons law of cooling. The heat flux is calculated out of demolding heat (measured by means of calorimetry), injection heat (measured by means of an IR-sensor), cooling time and part mass. Cavity surface area, average mold surface temperature and average part surface temperature lead to the HTC.

  19. 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


    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....

  20. Investigation of Heat Transfer at the Mold/Metal Interface in Permanent Mold Casting of Light Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Robert D. Pehlke; John T. Berry


    Accurate modeling of the metal casting process prior to creating a mold design demands reliable knowledge of the interfacial heat transfer coefficient at the mold metal interface as a function of both time and location. The phenomena concerned with the gap forming between the mold and the solidifying metal are complex but need to be understood before any modeling is attempted. The presence of mold coatings further complicates the situation. A commercial casting was chosen and studied in a gravity permanent mold casting process. The metal/mold interfacial heat transfer coefficient (IHTC) was the focus of the research. A simple, direct method has been used to evaluate the IHTC. Both the simulation and experiments have shown that a reasonably good estimate of the heat transfer coefficient could be made in the case studied. It has been found that there is a good agreement between experiments and simulations in the temperature profiles during the solidification process, given that the primary mechanism of heat transfer across the gap in permanent mold casting of light alloys is by conduction across the gap. The procedure utilized to determine the interfacial heat transfer coefficient can be applied to other casting processes. A recently completed project involving The University of Michigan and Mississippi State University, together with several industrial partners, which was supported by the USDOE through the Cast Metals Coalition, examined a number of cases of thermal contact. In an investigation which gave special consideration to the techniques of measurement, several mold coatings were employed and results presented as a function of time. Realistic conditions of coating thickness and type together with an appropriate combination of mold preheat and metal pouring temperature were strictly maintained throughout the investigation. Temperature sensors, in particular thermocouples, play an important part in validating the predictions of solidification models. Cooling

  1. Foaming morphology control of microcellular injection molded parts with gas counter pressure and dynamic mold temperature control (United States)

    Shiu, Tai-Yi; Huang, Chao-Tsai; Chang, Rong-Yu; Hwang, Shyh-Shin


    Microcellular injection molding process is a promising solution for products with special requirements such as weight reduction, extra thin wall, high dimensional stability, clamping force reduction, etc. Despite microcellular foaming application used in reciprocating screw injection molding machine was built more than a decade, some limitations, such as poor surface quality or poor foaming control, confine the usage of this technology. Earlier CAE simulation tool for microcellular injection molding was not successful due to insufficient physical and computational considerations, limited by complicated bubble growth mechanism; so that, an economic and efficient tool for examining foaming quality of injection foaming product was lack. In this study, a recent developed three-dimensional simulation tool is used to predict injection foaming process. Predictions are carried out with commodity polypropylene and polystyrene with nitrogen and carbon dioxide supercritical fluids (SCFs). Comparisons of simulations between microcellular injection molding with and without counter pressure are discussed to provide insights into the correlation of surface quality and cell size distribution near the surface of product. Furthermore, comparisons between simulation predictions and experimental results of molding process, which is featured with dynamic mold temperature and gas counter pressure, are given for understanding quality improvement by controlling foaming morphology, and benefit of industrial application.

  2. 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


    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.

  3. Effect of cross sectional geometry on PDMS micro peristaltic pump performance: comparison of SU-8 replica molding vs. micro injection molding. (United States)

    Graf, Neil J; Bowser, Michael T


    Two different fabrication methods were employed to fabricate micropumps with different cross-sectional channel geometries. The first was to fabricate rectangular cross-sectional microchannel geometries using the well known fabrication method of replica molding (REM). The second, and far less utilized fabrication technique, was to create microchannel molds using an in-house fabricated handheld micro injection molding apparatus. The injection mold apparatus was designed for use with elastomeric room temperature vulcanization (RTV) polymers, as opposed to most other injection molding machines, which are designed for use with thermoplastic polymers. The injection mold's bottom plate was used as a microchannel molding template. The molding template was created by threading a small-diameter wire (150 μm or less) through the injection mold's bottom plate, with subsequent adhesion and smoothing of a thin piece of aluminum foil over the wire-raised injection mold template. When molded against, the template produced a rounded/Gaussian-shaped PDMS microchannel. The design of the injection mold will be presented, along with a direct comparison for micropump performance metrics such as flow rate, valving characteristics, and maximum backpressures attainable for each of the respective micropump channel geometries.

  4. Agarose gel as biomaterial or scaffold for implantation surgery: characterization, histological and histomorphometric study on soft tissue response. (United States)

    Varoni, Elena; Tschon, Matilde; Palazzo, Barbara; Nitti, Paola; Martini, Lucia; Rimondini, Lia


    Maxillofacial, orthopedic, oral, and plastic surgery require materials for tissue augmentation, guided regeneration, and tissue engineering approaches. In this study, the aim was to develop and characterize a new extrudable hydrogel, based on agarose gel (AG; 1.5% wt) and to evaluate the local effects after subcutaneous implantation in comparison with collagen and hyaluronic acid. AG chemical-physical properties were ascertained through Fourier transform infrared (FT-IR) spectroscopy and rheological analysis. In vivo subcutaneous implants were performed, and histological and histomorphometric evaluations were done at 1, 4, 12, and 16 weeks. FT-IR confirmed that spectroscopic properties were the same for the baseline agarose and rheological characterization established that AG is a weak hydrogel. Subcutaneous AG implants induced new vessels and fibrous tissue formation rich in neutrophils; the capsule thickness around AG increased until the 12th week but remained thinner than those around hyaluronic acid and collagen. At 16 weeks, the thickness of the capsule significantly decreased around all materials. This study confirmed that 1.5% wt AG possesses some of the most important features of the ideal biocompatible material: safety, effectiveness, costless, and easily obtained with specific chemical and geometrical characters; the AG can represent a finely controllable and biodegradable polymeric system for cells and drug delivery applications.

  5. Supplementation of exogenous adenosine 5'-triphosphate enhances mechanical properties of 3D cell-agarose constructs for cartilage tissue engineering. (United States)

    Gadjanski, Ivana; Yodmuang, Supansa; Spiller, Kara; Bhumiratana, Sarindr; Vunjak-Novakovic, Gordana


    Formation of tissue-engineered cartilage is greatly enhanced by mechanical stimulation. However, direct mechanical stimulation is not always a suitable method, and the utilization of mechanisms underlying mechanotransduction might allow for a highly effective and less aggressive alternate means of stimulation. In particular, the purinergic, adenosine 5'-triphosphate (ATP)-mediated signaling pathway is strongly implicated in mechanotransduction within the articular cartilage. We investigated the effects of transient and continuous exogenous ATP supplementation on mechanical properties of cartilaginous constructs engineered using bovine chondrocytes and human mesenchymal stem cells (hMSCs) encapsulated in an agarose hydrogel. For both cell types, we have observed significant increases in equilibrium and dynamic compressive moduli after transient ATP treatment applied in the fourth week of cultivation. Continuous ATP treatment over 4 weeks of culture only slightly improved the mechanical properties of the constructs, without major changes in the total glycosaminoglycan (GAG) and collagen content. Structure-function analyses showed that transiently ATP-treated constructs, and in particular those based on hMSCs, had the highest level of correlation between compositional and mechanical properties. Transiently treated groups showed intense staining of the territorial matrix for GAGs and collagen type II. These results indicate that transient ATP treatment can improve functional mechanical properties of cartilaginous constructs based on chondrogenic cells and agarose hydrogels, possibly by improving the structural organization of the bulk phase and territorial extracellular matrix (ECM), that is, by increasing correlation slopes between the content of the ECM components (GAG, collagen) and mechanical properties of the construct.

  6. Cross-linked poly(acrylic acids) microgels and agarose as semi-interpenetrating networks for resveratrol release. (United States)

    Tunesi, Marta; Prina, Elisabetta; Munarin, Fabiola; Rodilossi, Serena; Albani, Diego; Petrini, Paola; Giordano, Carmen


    Carbomers, cross-linked poly(acrylic acid) microgels, have been widely used in pharmaceutical formulations as swollen hydrogels. Agarose, whose thermoreversibility may be exploited for drug loading, forms a gel with a mechanism involving coil-helix transition at about 36 °C. In this work carbomer microgels were combined with agarose networks in a semi-interpenetrating polymer network structure, aiming at obtaining suitable delivery systems for the loading and release of molecules with poor bioavailability but high therapeutic interest, like resveratrol. The rheological properties of the formulations and their in vitro cytocompatibility were studied and optimized acting on the neutralizing agent (triethylamine (N,N-diethylethanamine), triethanolamine (tris(2-hydroxyethyl)amine) and sodium hydroxide) and amount of OH donors (1,2-propanediol and glycerol). As a preparation method, autoclaving was introduced to simultaneously obtain heating and sterilising. Among the different neutralizing agents, NaOH was chosen to avoid the use of amines, considering the final application. Without the addition of alcohols as typical OH donors to induce Carbomer gelification, gels with appropriate rheological properties and stability were produced. For this formulation, the release of resveratrol after 7 days was about 80 % of the loaded mass, suggesting it is an interesting approach to be exploited for the development of innovative resveratrol delivery systems.

  7. Analysis of Injection Molding Process Based on MoldFlow/MPI for Large Plastic Pallet%基于MoldFlow/MPI的大型塑料托盘注射成型分析

    Institute of Scientific and Technical Information of China (English)



    运用MoldFlow/MPI模块对大型塑料托盘注射成型过程进行模流分析,预测了可能出现的注射短射等缺陷,根据分析结果,提出了工艺优化方案,从而缩短模具设计制造周期。%Used MoldFlow/MPI to analyze the mold flow for the large plastic pallet molding process, and predict the possible injection molding defects such as injection molding short shot. According to the analysis, it gives process optimization to reduce the mold design and manufacture cycle.

  8. Disease management and medication compliance. (United States)

    Cohen, Joshua; Christensen, Kathyrn; Feldman, Lanna


    Lack of medication compliance is harmful to health care systems from both a clinical and economic perspective. This study examines the methods that disease management organizations employ to identify nonadherent patients and to measure effectiveness of compliance programs for patients with diabetes, hyperlipidemia, and cystic fibrosis. In addition, this study investigates the degree to which disease managers assume risk in their contracts, and whether compliance strategies are being coordinated with payers' use of value-based insurance design, in which patient cost sharing is a function of the relative value of pharmaceuticals. This study's findings suggest that disease management may be falling short in terms of: (a) comprehensive commitment to expert-recommended at-home devices used to self-diagnose and measure health indicators; (b) early adoption of expert-recommended new technologies to measure and improve compliance; (c) intensity of use of standard tests in outpatient clinics; (d) coordination of compliance strategies with payers' use of value-based insurance design; and (e) the proportion of risk assumed in disease management contracts.

  9. Residual stress distribution in injection molded parts

    Directory of Open Access Journals (Sweden)

    P. Postawa


    Full Text Available Purpose: The paper presents the results of the investigations of influence of the amorphous polystyrene (PSprocessing on the diversity of the internal stresses observed in the injection moulded piece.Design/methodology/approach: For the tests, the standardized mould piece designed for the investigations ofthe processing shrinkage of thermoplastics materials has been used. The samples have been prepared using theDesign of Experiment (DoE theory.The state of internal stresses has been analysed by means of photoelastic method (used stress viewer equipmenton the basis of the layout and size of the isochromatics (fields with the same colour, which determine the mouldpiece’s areas where the same value for the difference of main tensions. In the article the results of investigationsof influence of 5 chosen processing parameters such as injection temperature Tw, mould temperature Tf,clamping pressure pd, cooling time tch and the injection speed vw on the changes in isochromatics layout as adeterminant for diversity of internal stresses in injection moulded pieces have been presented.Findings: The performed investigations of the influence of injection conditions on the state of internal stressesreached for injection mould pieces were to determine the parameters of injection at which the achieved state ofthe stresses in the mould piece (described by the difference of main tensions will show the lowest values.Practical implications: Effects of examinations of influence of processing conditions on residual stress ininjection molded parts (presented in the article could find practical application in polymer industry, both smalland large enterprises.Originality/value: New approach to fast estimation of value of residual stresses were present in the paper.

  10. The thermal distortion of continuous-casting billet molds (United States)

    Samarasekera, I. V.; Anderson, D. L.; Brimacombe, J. K.


    Preliminary mathematical analyses involving plate bending theory and two-dimensional elastic calculations have revealed that the dominant component contributing to the distortion of continuous-casting billet molds is thermal expansion in the transverse directions. A three-dimensional, elasto-plastic, finite-element analysis of the mold wall has then shown that localized yielding initiates in a region close to the meniscus. The plastic flow is a result of the high thermal stresses induced by the geometric restraint to bending coupled with the locally high temperatures. The resultant distortion profile of the mold down the centerline of a face exhibits a maximum outward bulge of 0.1 to 0.3 mm, which is bounded above by a region of negative taper (1˜2 pct/m) and below by a region of positive taper (˜0.4 pct/m). Measurements of mold wall movement in an operating billet caster using linear displacement transducers compare favorably with model predictions, except in the meniscus region. Case studies of several industrial billet molds have shown that lowering the meniscus level with respect to the location of constraints, or modifying the method of support of the mold tube within its housing so as to reduce the restraint to thermal expansion in the meniscus region, may minimize the extent of permanent distortion. Also, wall thickness can have a significant effect on thermal distortion. Increasing wall thickness results in an increase in both peak wall temperatures and thermal gradients. The former increases the local distortion while the latter causes higher thermal stress levels and possibly permanent distortion. Of the casting variables that can be manipulated to major advantage, cooling water flow rate is the most important. Increasing the water velocity reduces mold wall temperatures, as well as both the total and permanent distortion of the wall.

  11. Diagnosis parameters of mold filling pattern for optimization of a casting system

    Directory of Open Access Journals (Sweden)

    Jun-Ho Hong


    Full Text Available For optimal design of a gating system, the setting of diagnosis parameters is very important. In this study, the permanent mold casting process was selected because most of the other casting processes have more complicated factors that influence the mold filling pattern compared to the permanent mold casting process, such as the surface roughness of mold, gas generation from the mold wash and binder of sand mold, and the gas permeability through a sand mold, etc. Two diagnosis parameters (flow rate difference and arrival time difference of molten metal flow pattern in the numerical simulation are suggested for design of an optimum casting system with a permanent mold. The results show that the arrival time difference can be used as one important diagnosis parameter of the complexity of the runner system and its usefulness has been verified via making aluminum parts using permanent mold casting (Fig. 9.

  12. Improvement of machining quality of copper-plated roll mold by controlling temperature variation

    Institute of Scientific and Technical Information of China (English)

    Tae-Jin JE; Eun-Chae JEON; Sang-Cheon PARK; Doo-Sun CHOI; Kyung-Hyun WHANG; Myung-Chang KANG


    Micro prism film used in LCD industry can be manufactured by roll to roll method with copper-plated roll mold. As copper-plated roll mold is getting larger, pitch error is getting severer. The pitch error drops the quality of micro prism film. The main cause of the pitch error was investigated during machining large roll mold whose machined length was 1 200 mm. The temperature of machining system was elevated during machining roll mold, and this elevation induced thermal expansion of the system. The temperature variation around the roll mold also made thermal expansion of the roll mold. The amount of thermal expansion had strong relationship to the amount of pitch error. Therefore, the roll mold was machined after warming-up of machining system and precise temperature controller around copper-plated roll mold was installed, which minimized the temperature variation. Finally,precise micro prism patterns without pitch error were machined on the large roll mold.

  13. Orientation of Carbon Fibers in Copper matrix Produced by Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Irfan Shirazi M.


    Full Text Available Fiber orientation is a big challenge in short fiber reinforced composites. Powder injection molding (PIM process has some intrinsic fiber alignment associated with it. During PIM process fibers in skin region of moldings are aligned as these regions experience higher shear flow caused by the mold walls. Fibers in the core region remain randomly aligned as these regions are far from mold walls and experience lesser shear flow. In this study short carbon fiber (CF reinforced copper matrix composite was developed by PIM process. Two copper composite feedstock formulations were prepared having 5 vol% and 10 vol% CFs and a wax based binder system. Fiber orientation was controlled during injection molding by using a modified mold that has a diverging sprue. The sprue creates converging flow when feedstock enters into the mold cavity. Fiber orientation was analysed after molding using FESEM. The orientation of fibers can be controlled by controlling flow of feedstock into the mold.

  14. Corporate compliance and voluntary disclosure. (United States)

    Schiff, A B


    In any event, the decision to institute a corporate compliance program is a relatively simple one. In view of the ambiguity surrounding certain fraud and abuse provisions, and the corporate "death sentence" that may result from program exclusion, a compliance program is always sound corporate policy. To be sure, if the compliance program is administered improperly, it can actually increase the likelihood of whistleblower actions and create a body of potentially hurtful documentation. But these dangers can be minimized by structuring the program to protect the self-evaluative process through relevant privileges. The risks also pale in comparison to the exposure to criminal or exclusionary sanctions when improper conduct goes undetected by an organization.

  15. Tax Compliance Inventory: TAX-I Voluntary tax compliance, enforced tax compliance, tax avoidance, and tax evasion. (United States)

    Kirchler, Erich; Wahl, Ingrid


    Surveys on tax compliance and non-compliance often rely on ad hoc formulated items which lack standardization and empirical validation. We present an inventory to assess tax compliance and distinguish between different forms of compliance and non-compliance: voluntary versus enforced compliance, tax avoidance, and tax evasion. First, items to measure voluntary and enforced compliance, avoidance, and evasion were drawn up (collected from past research and newly developed), and tested empirically with the aim of producing four validated scales with a clear factorial structure. Second, findings from the first analyses were replicated and extended to validation on the basis of motivational postures. A standardized inventory is provided which can be used in surveys in order to collect data which are comparable across research focusing on self-reports. The inventory can be used in either of two ways: either in its entirety, or by applying the single scales independently, allowing an economical and fast assessment of different facets of tax compliance.

  16. Social influence: compliance and conformity. (United States)

    Cialdini, Robert B; Goldstein, Noah J


    This review covers recent developments in the social influence literature, focusing primarily on compliance and conformity research published between 1997 and 2002. The principles and processes underlying a target's susceptibility to outside influences are considered in light of three goals fundamental to rewarding human functioning. Specifically, targets are motivated to form accurate perceptions of reality and react accordingly, to develop and preserve meaningful social relationships, and to maintain a favorable self-concept. Consistent with the current movement in compliance and conformity research, this review emphasizes the ways in which these goals interact with external forces to engender social influence processes that are subtle, indirect, and outside of awareness.

  17. UG Mold Wizard in injection mold design application%UG MoldWizard在注射模具设计中的应用

    Institute of Scientific and Technical Information of China (English)

    陆龙福; 黄常翼


    Currently plastics increasingly broad application areas, plastic products has become the automotive, aerospace, electrical and electronics, packaging, building materials, agriculture and other fields indispensable parts and plastic parts are produced almost all through the plastic mold molding to obtain The. As technology advances and high-tech product development and continuous innovation, the technical plastics increasingly high demand, relying on manual mold design and manufacturing engineers is difficult to meet the needs of the development of production. UG mold soft-ware emergence and development, has become a contemporary mold design and manufacture of an important and indis-pensable auxiliary tools.%目前塑料制品的应用领域日益广阔,塑料产品已成为汽车、航空航天、电子电气、包装、建材、农业等领域中不可缺少的部分,而塑料制件的生产几乎都是通过塑料模具的成型来获得的。随着技术进步以及高科技产品的不断开发与创新,对塑料制品的各项技术要求越来越高,仅靠模具工程师手工设计与制造很难满足生产发展的需要。 UG模具软件的出现与发展,已成为当代模具设计与制造中不可缺少的重要辅助工具之一。

  18. Mold and mycotoxin problems encountered during malting and brewing. (United States)

    Wolf-Hall, Charlene E


    Fusarium infections in grains can have severe effects on malt and beer. While some degree of Fusarium mycotoxins, such as deoxynivalenol, present in infected barley may be lost during steeping, the Fusarium mold is still capable of growth and mycotoxin production during steeping, germination and kilning. Therefore, detoxification of grain before malting may not be practical unless further growth of the mold is also prevented. Methods to reduce the amount of mold growth during malting are needed. Physical, chemical and biological methods are reviewed. Irradiation looks very promising as a means to prevent Fusarium growth during malting, but the effect on the surviving mold to produce mycotoxins and the effect on malt quality needs further study. Chemical treatments such as ozonation, which would not leave residual chemical in the beer also appear to be promising. Although biological control methods may be desirable, due to the use of "natural" inhibition, the effects of these inhibitors on malt and beer quality requires further investigation. It may also be possible to incorporate detoxifying genes into fermentation yeasts, which would result in detoxification of the wort when mold growth is no longer a problem. Development of these types of technological interventions should help improve the safety of products, such as beer, made from Fusarium infected grain.

  19. Relevant Aspects in Modeling of Micro-injection Molding (United States)

    Nguyen-Chung, Tham; Jüttner, Gábor; Pham, Tung; Mennig, Günter


    Growing demands in the manufacturing of micro and precision components in plastics require new concepts for molding machines and micro molds on the one hand. On the other hand, a deeper understanding of the filling and solidification process in a micro mold is indispensable. In this work, the filling process of a micro spiral was analyzed by modeling the compressible flow using pressure dependent viscosity and adjusted heat transfer coefficients. At the same time, experimental filling studies were carried out on an accurately controlled micro-injection molding machine. Based on the relationship between the injection pressure and the filling degree, essential factors for the quality of the simulation can be identified. It can be shown that the flow behavior of the melt in a micro cavity of high aspect ratio is extremely dependent on the melt compressibility in the injection cylinder which needs to be considered in the simulation in order to predict an accurate flow rate. Moreover, the heat transfer coefficients between the melt and the mold wall vary significantly when changing cavity thickness and processing conditions. It is believed that a pressure dependent model for the heat transfer coefficient would be able to improve the quality of the process simulation.

  20. Measuring mechanical stresses on inserts during injection molding

    Directory of Open Access Journals (Sweden)

    Martina Heinle


    Full Text Available Assembly molding presents an interesting approach to innovative product solutions. Here, individual components can be simultaneously positioned, affixed, and provided with a casing. However, while overmolding elements in the mold cavity with hot polymer melt, high mechanical loads occur on, in some cases, very sensitive components such as electronic devices. For the design of such systems, it is important to know these stresses, the influences on their quantities, and mathematical options for their prediction. In this article, a new measurement method for determining the forces acting on a small element in the cavity during the injection molding process in three dimensions is presented. Therefore, a new installation method for a force sensor was developed. The results in this article concentrate on force changes during one molding cycle. Our research shows that there are different mechanical load spectra in the different phases of the molding process. For example, the force component in flow direction on an element in the cavity is positive in the direction of the flow during filling. However, after the filling step, the force becomes negative due to the contraction of the injected material and results in a continuously increasing permanent force.

  1. Computer Texture Mapping for Laser Texturing of Injection Mold

    Directory of Open Access Journals (Sweden)

    Yongquan Zhou


    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.

  2. An investigation into the injection molding of PMR-15 polyimide (United States)

    Colaluca, M. A.


    The chemorheological behavior of the PRM-15 molding compounds were characterized, the range of suitable processing parameters for injection molding in a reciprocating screw injection molding machine was determined, and the effects of the injection molding processing parameters on the mechanical properties of molded PMR-15 parts were studied. The apparatus and procedures for measuring viscosity and for determining the physical response of the material during heating are described. Results show that capillary rheometry can be effectively used with thermosets if the equipment is designed to overcome some of the inherent problems of these materials. A uniform temperature was provided in the barrel by using a circulating hot oil system. Standard capillary rheometry methods can provide the dependence of thermoset apparent viscosity on shear rate, temperature, and time. Process conditions resulting in complete imidization should be carefully defined. Specification of controlled oven temperature is inadequate and can result in incomplete imidization. For completely imidized PMR-15 heat at 15 C/min melt flow without gas evolution occurs in the temperature range of 325 C to 400 C.

  3. An in-mold packaging process for plastic fluidic devices. (United States)

    Yoo, Y E; Lee, K H; Je, T J; Choi, D S; Kim, S K


    Micro or nanofluidic devices have many channel shapes to deliver chemical solutions, body fluids or any fluids. The channels in these devices should be covered to prevent the fluids from overflowing or leaking. A typical method to fabricate an enclosed channel is to bond or weld a cover plate to a channel plate. This solid-to-solid bonding process, however, takes a considerable amount of time for mass production. In this study, a new process for molding a cover layer that can enclose open micro or nanochannels without solid-to-solid bonding is proposed and its feasibility is estimated. First, based on the design of a model microchannel, a brass microchannel master core was machined and a plastic microchannel platform was injection-molded. Using this molded platform, a series of experiments was performed for four process or mold design parameters. Some feasible conditions were successfully found to enclosed channels without filling the microchannels for the injection molding of a cover layer over the plastic microchannel platform. In addition, the bond strength and seal performance were estimated in a comparison with those done by conventional bonding or welding processes.

  4. Microwaves energy in curing process of water glass molding sands

    Directory of Open Access Journals (Sweden)

    Granat K.


    Full Text Available This work presents the results of investigation of microwave heating on hardening process of water glass molding sands. Essential influence of this heating process on basic properties such as: compression, bending and tensile strength as well as permeability and abrasion resistance has been found. It has been proved, that all investigated sorts of sodium water glass with a module between 2.0 and 3.3 can be used as a binder of molding sands in microwave curing process. It has been found during analysis of research results of sands with 2.5 % water glass addition that they are practically the same as in case of identical molding sands dried for 120 minutes at the temperature of 110°C, used for comparative purposes. Application of microwave curing of molding sands with water glass, however, guarantees reduction of hardening time (from 120 to 4 minutes as well as significant reduction of energy consumption. Attempts of two stage hardening of the investigated water glass molding sands have also been carried out, that is after an initial hardening during a classical CO2 process (identical sands have also been tested for comparison after CO2 blowing process and additional microwave heating. It has been found that application of this kind of treatment for curing sands with 2.5 % sodium water glass content and module from 2.0 up to 3.3 results in the improvement of properties in comparison to classical CO2 process.

  5. Surface Graphite Degeneration in Ductile Iron Castings for Resin Molds

    Institute of Scientific and Technical Information of China (English)

    Iulian Riposan; Mihai Chisamera; Stelian Stan; Torbjorn Skaland


    The objective of this paper is to review the factors influencing the formation of degenerated graph-ite layers on the surfaces of ductile iron castings for chemical rosins-acid molding and coro-making systems and how to reduce this defect. In the rosin mold technique the sulphur in the P-toluol sulphonic acid (PTSA),usually used as the hardener, has been identified as one factor causing graphite degeneration at the metal-mold interface. Less than 0.15% S in the mold (or even less than 0.07% S) can reduce the surface layer depth. Oxygen may also have an effect, especially for sulphur containing systems with turbulent flows in the mold, water-bearing no-bake binder systems, Mg-Silica reactions, or dross formation conditions. Despite the lower level of nitrogen in the iron melt after magnesium treatment (less than 90 ppm), nitrogen bearing res-ins have a profound effect on the frequency and severity of surface pinholes, but a limited influence on sur-face graphite degeneration.

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

    Directory of Open Access Journals (Sweden)

    J. Tepić


    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.

  7. Discussion on compact mechanism of air-stream and synchro-formed clamp plate impact molding

    Directory of Open Access Journals (Sweden)

    Zhenling WANG


    Full Text Available Applying the air impact molding method to mold the complicated pattern with wider opening surface and deeper concave, there always exist vaulted phenomenon and lower compactibility of sand mold over the entrance and the concave regions. Using the air-stream and synchro-formed clamp plate impact molding, however, this problem will be preferably solved. In this paper, the compact mechanism of the new molding method and the effect of some configuration factors, such as the area flowed by compressed air and the highness of the protruding block displacement around the diffluent clamp plate, on the compactibility of sand mold were discussed.

  8. Detection of mutations using microarrays of poly(C)10-poly(T)10 modified DNA probes immobilized on agarose films

    DEFF Research Database (Denmark)

    Dufva, Hans Martin; Petersen, Jesper; Stoltenborg, M.


    to an agarose film grafted onto unmodified glass. Microarrays of TC-tagged probes immobilized on the agarose film can be used to diagnose Mutations in the human P-globin gene, which encodes the beta-chains in hemoglobin. Although the probes differed widely regarding inciting point temperature (similar to 20...... degrees C), a single stringency wash still gave sufficiently high discrimination signals between perfect match and mismatch probes to allow robust mutation detection. In all, 270 genotypings were performed on patient materials, and no genotype was incorrectly classified. Quality control experiments...

  9. 24 CFR 108.25 - Compliance meeting. (United States)


    ... COMPLIANCE PROCEDURES FOR AFFIRMATIVE FAIR HOUSING MARKETING § 108.25 Compliance meeting. (a) Scheduling... the goals of the AFHM plan may not be achieved, or that the implementation of the Plan should...

  10. Mobile Source Emissions Regulatory Compliance Data (United States)

    U.S. Environmental Protection Agency — The Engine and Vehicle Compliance Certification and Fuel Economy Inventory contains measured emissions and fuel economy compliance information for all types of...

  11. Client Compliance with Homework Directives during Counseling. (United States)

    Worthington, Everett L., Jr.


    Investigated compliance as a function of counselor, client, and therapy variables. Results indicated that variables associated with the conduct of counseling more strongly influenced compliance with homework than did either counselor or client variables. (Author/BL)

  12. Clean Air Markets - Compliance Query Wizard (United States)

    U.S. Environmental Protection Agency — The Compliance Query Wizard is part of a suite of Clean Air Markets-related tools that are accessible at The Compliance module provides...

  13. Mobile Source Emissions Regulatory Compliance Data Inventory (United States)

    U.S. Environmental Protection Agency — The Mobile Source Emissions Regulatory Compliance Data Inventory data asset contains measured summary compliance information on light-duty, heavy-duty, and non-road...

  14. Developing a nursing corporate compliance program. (United States)

    Bartis, Janice A; Sullivan, Trent


    This article presents the process that a large urban tertiary care hospital engaged in when developing a corporate compliance program for nursing. The purpose of this article is to demonstrate how nurse executives can successfully implement a comprehensive and practical nursing corporate compliance program. This article describes in detail the 5 steps the hospital took to develop its nursing corporate compliance program and provides examples of tools to guide you in developing a nursing corporate compliance program.

  15. Application of Vacuum Drying to Silica Sol Ceramic Mold

    Institute of Scientific and Technical Information of China (English)

    Ming ZENG; Xinqiang YUAN; Baoluo SHEN; Yunqiu ZHENG


    Silica sol ceramic mold was made at room temperature with JN-30 silica sol, silica powder and NH4Cl. It is found that the harden time of silica sol ceramic mold is only 0.5 to 1.5 h under the amount of NH4CI solution of 7% to 8% with 15% concentration, and less surface cracks occur by using vacuum drying. The proper vacuum drying process parameters: vacuum drying temperature is 80 to 100℃, drying time is 5 h and vacuum is 0.06 to 0.07 MPa. The harden mechanics, vacuum drying mechanics and the reason of less surface cracks of silica sol ceramic mold by vacuum drying were also analyzed in this paper.

  16. Treatment principles for the management of mold infections. (United States)

    Kontoyiannis, Dimitrios P; Lewis, Russell E


    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.

  17. Injection Molding and its application to drug delivery. (United States)

    Zema, Lucia; Loreti, Giulia; Melocchi, Alice; Maroni, Alessandra; Gazzaniga, Andrea


    Injection Molding (IM) consists in the injection, under high pressure conditions, of heat-induced softened materials into a mold cavity where they are shaped. The advantages the technique may offer in the development of drug products concern both production costs (no need for water or other solvents, continuous manufacturing, scalability, patentability) and technological/biopharmaceutical characteristics of the molded items (versatility of the design and composition, possibility of obtaining solid molecular dispersions/solutions of the active ingredient). In this article, process steps and formulation aspects relevant to IM are discussed, with emphasis on the issues and advantages connected with the transfer of this technique from the plastics industry to the production of conventional and controlled-release dosage forms. Moreover, its pharmaceutical applications thus far proposed in the primary literature, intended as either alternative manufacturing strategies for existing products or innovative systems with improved design and performance characteristics, are critically reviewed.

  18. Influence of melt mixer on injection molding of thermoset elastomers (United States)

    Rochman, Arif; Zahra, Keith


    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.

  19. Modeling of Mold Filling and Solidification in Lost Foam Casting

    Institute of Scientific and Technical Information of China (English)

    Fengjun LI; Houfa SHEN; Baicheng LIU


    Based on the characteristics of the lost foam casting (LFC) and the artificial neural network technique, a mathematicalmodel for the simulation of the melt-pattern interface movement during the mold filling of LFC has been proposed andexperimentally verified. The simulation results are consistent with the experiments in both the shapes of melt frontand filling sequences. According to the calculated interface locations, the fluid flow and the temperature distributionsduring the mold filling and solidification processes were calculated, and the shrinkage defect of a lost foam ductileiron casting was predicted by considering the mold wall movement in LFC. The simulation method was applied tooptimize the casting design of lost foam ductile iron castings. It is shown that the model can be used for the defectsprediction and for casting design optimization in the practical LFC production.

  20. Long fiber polymer composite property calculation in injection molding simulation (United States)

    Jin, Xiaoshi; Wang, Jin; Han, Sejin


    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.

  1. Permanent Mold Casting of JIS-AC4C Aluminum Alloy Using a Low-Temperature Mold (United States)

    Yamagata, Hiroshi; Nikawa, Makoto


    Permanent mold casting using mold temperatures below 200° 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.

  2. 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: [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)


    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.

  3. Corporate compliance: implications for trustees. (United States)

    Commins, K


    In this era of fraud and abuse enforcement efforts, hospital trustees are facing potential liability in the event that an investigation reveals the hospital has violated state or federal provisions pertaining to fraud and abuse. This liability can be minimized, or avoided, by ensuring that an effective compliance plan is in place prior to such an investigation.

  4. Best Practices and Simultaneous Compliance (United States)

    This wrap-up presentation to the workshop covers several topics concerning how lead and copper compliance under the Lead and Copper Rule should be integrated into an overall “simultaneous compliance” framework with other organizations. The LCR requires “optimization” of lead leve...

  5. Audit-based compliance control

    NARCIS (Netherlands)

    Cederquist, J.G.; Corin, R.; Dekker, M.A.C.; Etalle, S.; Hartog, J.I. den; Lenzini, G.


    In this paper we introduce a new framework for controlling compliance to discretionary access control policies [Cederquist et al. in Proceedings of the International Workshop on Policies for Distributed Systems and Networks (POLICY), 2005; Corin et al. in Proceedings of the IFIP Workshop on Formal A

  6. Project Compliance with Enterprise Architecture

    NARCIS (Netherlands)

    Foorthuis, R.M.


    This research project set out to identify effective practices and models for working with projects that are required to comply with Enterprise Architecture (EA), and investigate the benefits and drawbacks brought about by compliance. Research methods used are canonical action research, a statistical


    Directory of Open Access Journals (Sweden)

    ANDREESCU Nicoleta Alina


    Full Text Available In this paper, we have studied the evolution of the business ethics concept through the prism of definitions from some renowned authors in the field and through the approach model of the business ethics and by implementing it in the company level. We have found out that in the last 40 years this concept has evolved from a theoretical aspect, as well as a practical one. Companies are motivated to implement ethics and compliance programs in business so that they can manage the changes that come from society. If, until recently, all that mattered for a company was profit, in the last decades, the situation changed. In order to develop a durable business, it is essential to have a good reputation. Owning and implementing an ethics and compliance program in business has become an imperative for companies, regardless of their activity sector. The role of the compliance department becomes more pregnant in each company: the employees need safety, the existence of communication lines provides comfort. From the partners in business’ point of view, owning such a program is a necessity, a condition, and not conforming to the principles of business ethics can lead to the isolation of the company. The ethics and compliance programs in business are instruments that protect the company by implementing certain proactive identification mechanisms that ensure the development of an ethical organizational culture.

  8. 240 Mold Sensitization in Chronic Rhinosinusitis Patients (United States)

    Gawlik, Radoslaw; Czecior, Eugeniusz


    Background It is estimated that about 10% of the population have IgE antibodies to common inhalant molds. Exposure to fungal allergens could be linked to the presence and persistence of asthma, rhinitis and atopic dermatitis. Mold sensitization is a risk factor for development and deterioration of upper airway allergy, especially chronic rhinosinusitis. We addressed the incidence of mold allergy measured as specific IgE to molds and skin prick tests in chronic sinusitis patients. We assessed prevalence of allergic reactions to mould among surgery treated chronic sinusitis patients. Methods A group of 28 chronic sinusitis patients after surgery were included into the study. Routine medical examination, skin prick tests with common inhaled allergens and extended mold panel (Alternaria alternate, Cladosporium herbarium, Aspergilus fumigatus, Candida albicans, Mucor mucedo, Botrytis cinerea, Rhisopus nigricans, Penicilliumi notatum, Fusarum moniliforme Pullularia pullulans (Allergopharma, Germany), tIgE, asIgE measurement were performed (Phadia, Sweden). All investigated patients were consulted by laryngologist and mycological examination was performed. Results We found that sensitization to at least one allergen was present in 43.8(14/32) of sinusitis patients. The most prevalent was sensitization to house dust mite Dermatophagoides pt., found in 21.8 % (7/32) patients. Positive results of skin prick tests with Candida albicans we observed in 18.8% (6/32), with Alternaria alternate in 15,6% (5/32), Cladosporium herbarium in 6,3% (2/32), Aspergilus fumigatus in 3,13 % (1/32). None of investigated patients presented sensitization to other mold allergens. Microbiological methods demonstrated fungal infection only in 2 patients. Conclusions Almost half of chronic sinusitis patients presented sensitization to at least one allergen. Fungal allergy is relatively rare in chronic sinusitis patients.

  9. 38 CFR 18.6 - Compliance information. (United States)


    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Compliance information... THE CIVIL RIGHTS ACT OF 1964 General § 18.6 Compliance information. (a) Cooperation and assistance... compliance reports at such times, and in such form and containing such information, as the responsible...

  10. 22 CFR 209.6 - Compliance information. (United States)


    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Compliance information. 209.6 Section 209.6... § 209.6 Compliance information. (a) Cooperation and assistance. The Administrator shall to the fullest... and accurate compliance reports at such times, and in such form and containing such information,...

  11. Tax compliance depends on voice of taxpayers

    NARCIS (Netherlands)

    Casal, Sandro; Kogler, C.; Mittone, Luigi; Kirchler, Erich


    Reducing the social distance between taxpayers and tax authorities boosts taxpayers' acceptance of tax load and tax compliance. In the present experiment participants had the opportunity to pay their tax due either as one single compliance decision or as separate compliance decisions for each type o

  12. Monitoring Compliance with Open Access policies


    Picarra, Mafalda


    In parallel to implementing Open Access policies, institutions and research funders are also engaged in developing mechanisms to monitor compliance with the existing policies. This study highlights why policy compliance must be monitored and how it can be done. A series of case studies illustrate where compliance is being effectively monitored.

  13. 40 CFR 425.05 - Compliance dates. (United States)


    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Compliance dates. 425.05 Section 425... STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY General Provisions § 425.05 Compliance dates. The compliance date for new source performance standards (NSPS) and pretreatment standards for...

  14. Corporate compliance: framework and implementation. (United States)

    Fowler, N


    The federal government has created numerous programs to combat fraud and abuse. The government now encourages healthcare facilities to have a corporate compliance program (CCP), a plan that reduces the chances that the facility will violate laws or regulations. A CCP is an organization-wide program comprised of a code of conduct and written policies, internal monitoring and auditing standards, employee training, feedback mechanisms and other features, all designed to prevent and detect violations of governmental laws, regulations and policies. It is a system or method ensuring that employees understand and will comply with laws that apply to what they do every day. Seven factors, based on federal sentencing guidelines, provide the framework for developing a CCP. First, a facility must establish rules that are reasonably capable of reducing criminal conduct. Second, high-level personnel must oversee the compliance effort. Third, a facility must use due care in delegating authority in the compliance initiative. Fourth, standards must be communicated effectively to employees, and fifth, a facility must take reasonable steps to achieve compliance. Sixth, standards must be enforced consistently across the organization and last, standards must be modified or changed for reported concerns, to ensure they are not repeated. PROMINA Health System, Inc. in Atlanta, Ga., designed a program to meet federal guidelines. It started with a self-assessment to define its areas or risk. Next, it created the internal structure and assigned organizational responsibility for running the CCP. PROMINA then developed standards of business and professional conduct, established vehicles of communication and trained employees on the standards. Finally, it continues to develop evidence of the program's effectiveness by monitoring and documenting its compliance activities.

  15. Biological Control of Olive Green Mold in Agaricus bisporus Cultivation. (United States)

    Tautorus, T E; Townsley, P M


    Successful methods to control the damaging weed mold Chaetomium olivaceum (olive green mold) in mushroom beds are not presently known. An attempt was made to control C. olivaceum by biological means. A thermophilic Bacillus sp. which showed dramatic activity against C. olivaceum on Trypticase soy agar (BBL Microbiology Systems)-0.4% yeast extract agar plates was isolated from commercial mushroom compost (phase I). When inoculated into conventional and hydroponic mushroom beds, the bacillus not only provided a significant degree of protection from C. olivaceum, but also increased yields of Agaricus bisporus.


    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin; Nguyen, Ba Nghiep; Mathur, Raj N.; Sharma, Bhisham; Sangid, Michael D.; Costa, Franco; Jin, Xiaoshi; Tucker III, Charles L.; Fifield, Leonard S.


    A set of edge-gated and center-gated plaques were injection molded with long carbon fiber-reinforced thermoplastic composites, and the fiber orientation was measured at different locations of the plaques. Autodesk Simulation Moldflow Insight (ASMI) software was used to simulate the injection molding of these plaques and to predict the fiber orientation, using the anisotropic rotary diffusion and the reduced strain closure models. The phenomenological parameters of the orientation models were carefully identified by fitting to the measured orientation data. The fiber orientation predictions show very good agreement with the experimental data.

  17. Study on Antigravity Mold Filling by Conservative Scalar Method

    Institute of Scientific and Technical Information of China (English)

    李日; 王友序; 杨根仓; 毛协民


    By SIMPLE method and Van-Leer scheme, a program on numerical simulation for 3D mold filling has been developed. The fluid flow field of gas and liquid is calculated in couples by a single phase N-S equation using SIMPLE method, and free surface control equation is handied by Van-Leer scheme. Then it is verified by an anti-gravity mold filling of thin wall plate. In order to demonstrate its ability to simulate 3D casting, an anti-gravity mould filling of a cube is computed by the program.

  18. Adsorption of human serum proteins onto TREN-agarose: purification of human IgG by negative chromatography. (United States)

    Bresolin, Igor Tadeu Lazzarotto; Borsoi-Ribeiro, Mariana; Caro, Juliana Rodrigues; dos Santos, Francine Petit; de Castro, Marina Polesi; Bueno, Sonia Maria Alves


    Tris(2-aminoethyl)amine (TREN) - a chelating agent used in IMAC - immobilized onto agarose gel was evaluated for the purification of IgG from human serum by negative chromatography. A one-step purification process allowed the recovery of 73.3% of the loaded IgG in the nonretained fractions with purity of 90-95% (based on total protein concentration and nephelometric analysis of albumin, transferrin, and immunoglobulins A, G, and M). The binding capacity was relatively high (66.63 mg of human serum protein/mL). These results suggest that this negative chromatography is a potential technique for purification of IgG from human serum.

  19. Hydrolysis Activities of the Particle of Agarose-Ce4 + Complex for Compounds Containing Phosphodiester or Peptide Bonds

    Institute of Scientific and Technical Information of China (English)

    YU Lina; WANG Dongfeng; SU Lin; LUO Yi; SUN Liping; XUE Changhu


    Hydrolysis activities of PACC (particle of agarose-Ce4+ complex, newly made through double emulsification) for compounds containing phosphodiester or peptide bonds were studied. The results showed that PACC could hydrolyze organophosphorous pesticides not only in water but also in vegetable juice or tea extract. Hydrolysis rates of methamidophos,omethoate and chlorpyrifos in water are 32.39%, 27.12% and 46.62% respectively, those of chlorpyrifos and methamidophos in mung sprout juice 38.28% and 35.45% respectively, and that of chlorpyrifos in tea extract 59.76%. Hydrolysis rates of BSA (bovine serum albumin) in water and protein in tea extract by PACC increase by 54.30% and 86.46% respectively as compared with the control.

  20. Polymer microlens array integrated with imaging sensors by UV-molding technique (United States)

    Lai, Jianjun; Zhao, Yue; Ke, Caijun; Yi, Xinjian; Zhang, TianXu


    Fabrication of Polymer microlens array based on UV-molding techniques is presented. UV-molding enables for the integration of polymer microlens array on top of arbitrary substrates like glass, silicon other polymeric films. In this technique, photoresist or glass mold is first fabricated by conventional photolithnic method and subsequently served as transparent replication tool. UV curable polymer resin is then coated on patterned or unpatterned substrates and a contact mask aligner is used to align substrates and replication mold tool and then make the mold immersed into the resin. Replication of polymer on substrates is achieved by UV photopolymerisation of the resin. Resin thickness and gap distance between mold and substrate are carefully controlled in order to obtain acceptable thickness of cured polymer base. The UV molding technique was used to molding of a polymer film carring microlens array on the surface of an experimental CCD imaging sensor chip in this paper to enhance its fill factor and sensitivity.

  1. Evaluation of the mold-filling ability of alloy melt in squeeze casting

    Institute of Scientific and Technical Information of China (English)


    The mold-filling ability of alloy melt in squeeze casting process was evaluated by means of the maximum length of Archimedes spiral line. A theoretical evaluating model to predict the maximum filling length was built based on the flowing theory of the incompressible viscous fluid. It was proved by experiments and calculations that the mold-filling pressure and velocity are prominent influencing factors on the mold-filling ability of alloy melt. The mold-filling ability increases with the increase of the mold-filling pressure and the decrease of the proper mold-filling velocity. Moreover, the pouring temperature relatively has less effect on the mold-filling ability under the experimental conditions. The maximum deviation of theoretical calculating values with experimental results is less than 15%. The model can quantitatively estimate the effect of every factor on the mold-filling ability.

  2. Finite element stress analysis of a compression mold. Final report. [Using SASL and WILSON codes

    Energy Technology Data Exchange (ETDEWEB)

    Watterson, C.E.


    Thermally induced stresses occurring in a compression mold during production molding were evaluated using finite element analysis. A complementary experimental stress analysis, including strain gages and thermocouple arrays, verified the finite element model under typical loading conditions.

  3. Application of statistical methods for analyzing the relationship between casting distortion, mold filling, and interfacial heat transfer in sand molds

    Energy Technology Data Exchange (ETDEWEB)

    Y. A. Owusu


    This report presents a statistical method of evaluating geometric tolerances of casting products using point cloud data generated by coordinate measuring machine (CMM) process. The focus of this report is to present a statistical-based approach to evaluate the differences in dimensional and form variations or tolerances of casting products as affected by casting gating system, molding material, casting thickness, and casting orientation at the mold-metal interface. Form parameters such as flatness, parallelism, and other geometric profiles such as angularity, casting length, and height of casting products were obtained and analyzed from CMM point cloud data. In order to relate the dimensional and form errors to the factors under consideration such as flatness and parallelism, a factorial analysis of variance and statistical test means methods were performed to identify the factors that contributed to the casting distortion at the mold-metal interface.

  4. The effect of mold materials on the overlay accuracy of a roll-to-roll imprinting system using UV LED illumination within a transparent mold (United States)

    Choi, Sungwoo; Kook, YunHo; Kim, ChulHo; Yoo, SoonSung; Park, Kwon-Shik; Kim, Seok-min; Kang, Shinill


    Although several studies on the roll-to-roll (R2R) imprinting process have reported achieving flexible electronics, improving the alignment accuracy in the overlay process of R2R imprinting is recognized as the biggest problem for the commercialization of this technology. For an overlay technique with high alignment accuracy, it is essential to develop a roll mold with high positional accuracy. In this study, a method for fabricating a roll mold with high positional accuracy is proposed by wrapping a thin glass substrate flexible mold around the transparent roll base, because it can provide higher mechanical strength and thermal stability than a conventional polymer substrate. To confirm the usability of the proposed process, the prepared roll mold was used to fabricate a test pattern of thin-film transistor backplane for a rollable display. The positional and overlay accuracy of the roll mold with the proposed thin glass substrate flexible mold were compared with the roll mold with a conventional polymer substrate flexible mold. Large-area transparent flexible molds with a size of 470  ×  370 mm were fabricated by an ultraviolet (UV) imprinting process on thin glass and polyethylene terephthalate substrates, and these flexible molds were wrapped around a roll base of 125 mm radius through a precision alignment process. After an anti-adhesion treatment and the wrapping process, the roll mold with the polymer substrate showed a ~180 μm positional error, whereas the thin glass substrate showed a ~30 μm positional error. After the overlay process using the R2R imprinting system with the alignment system, an average overlay error of ~3 μm was obtained when the thin glass flexible wrapped roll mold was used, whereas a ~22 μm overlay error was obtained when the polymer substrate flexible wrapped roll mold was used.

  5. Injection molding of iPP samples in controlled conditions and resulting morphology

    Energy Technology Data Exchange (ETDEWEB)

    Sessa, Nino, E-mail:; De Santis, Felice, E-mail:; Pantani, Roberto, E-mail: [Department of Industrial Engineering, University of Salerno, 84084 Fisciano (Italy)


    Injection molded parts are driven down in size and weight especially for electronic applications. In this work, an investigation was carried out on the process of injection molding of thin iPP samples and on the morphology of these parts. Melt flow in the mold cavity was analyzed and described with a mathematical model. Influence of mold temperature and injection pressure was analyzed. Samples orientation was studied using optical microscopy.

  6. Theoretical Analysis of the Solidification of Aluminum Alloy Billet in Air-Slip DC Mold

    Institute of Scientific and Technical Information of China (English)

    于赟; 马乃恒; 许振明; 李建国


    Based on the heat transfer analysis of Air-Slip DC mold, a numerical model was presented to study the quantitative relationships between critical solidification layer and casting rate, pouring temperature and mold cooling ability etc. The analytical results show that the Air-Slip mold heat transfer condition plays important roles on choices of a casting rate and the pouring temperature, and that the product of billet diameter and casting rate is a certain constant under a certain condition of the mold.

  7. Mold Species in Dust from the International Space Station Identified and Quantified by Mold Specific Quantitative PCR (United States)

    Vesper, Stephen J.; Wong, Wing; Kuo, C. Mike; Pierson, Duane L.


    Dust was collected over a period of several weeks in 2007 from various HEPA filters in the U.S. Laboratory Module of the International Space Station (ISS). The dust was returned on the Space Shuttle Atlantis, mixed, sieved, and the DNA was extracted. Using a DNA-based method called mold specific quantitative PCR (MSQPCR), 39 molds were measured in the dust. Opportunistic pathogens Aspergillus flavus and A. niger and toxin producers Penicillium chrysogenum and P. brevicompactum were found at relatively high concentrations (compared to U.S. homes). No cells of the opportunistic pathogens A. fumigatus, A. terreus, Fusarium solani or Candida albicans were detected.

  8. Quantifying mold biomass on gypsum board: Comparison of ergosterol and beta-N-acetylhexosaminidase as mold biomass parameters

    DEFF Research Database (Denmark)

    Reeslev, M.; Miller, M.; Nielsen, Kristian Fog


    Two mold species, Stachybotrys chartarum and Aspergillus versicolor, were inoculated onto agar overlaid with cellophane, allowing determination of a direct measurement of biomass density by weighing. Biomass density, ergosterol content, and beta-N-acetylhexosaminidase ( activity were...... monitored from inoculation to stationary phase. Regression analysis showed a good linear correlation to biomass density for both ergosterol content and beta-N-acetylhexosaminidase activity. The same two mold species were inoculated onto wallpapered gypsum board, from which a direct biomass measurement...

  9. Tools for NEPA compliance: Baseline reports and compliance guides

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, T.A. [Sandia National Labs., Albuquerque, NM (United States); Hansen, R.P. [Hansen Environmental Consultants, Englewood, CO (United States)


    Environmental baseline documents and NEPA compliance guides should be carried in every NEPA implementation ``tool kit``. These two indispensable tools can play a major role in avoiding repeated violations of NEPA requirements that have occurred over the past 26 years. This paper describes these tools, discusses their contents, and explains how they are used to prepare better NEPA documents more cost-effectively. Focus is on experience at Sandia Laboratories (NM).

  10. MoldFlow软件在梳子注射模结构改进及其成型缺陷分析中的应用%The Application of MoldFlow Software in the Structure Improvement and Analysis of forming Defects of Comb Injection Molding

    Institute of Scientific and Technical Information of China (English)



    MoldFlow software is applied to improve the mold structure and solve molding defects according to the problems of comb injection molding during trying mold. These will be provided some valuable references. Aunusual power is provided for the wide application of MoldFlow software in the design of injection mold.%根据梳子注射模在试模过程中存在的一些问题,采用MoldFlow软件进行分析,为改进模具结构、解决其成型缺陷提供有价值的参考。

  11. Validation of precision powder injection molding process simulations using a spiral test geometry

    DEFF Research Database (Denmark)

    Marhöfer, Maximilian; Müller, Tobias; Tosello, Guido;


    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 ...

  12. 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


    Replication of sub-micrometer structures by injection molding leads to special requirements for the mold in order to ensure proper replica and acceptable cycle time. This paper investigates the applicability of induction heating embedded into the mold for the improvement of nanopattern replicatio...

  13. 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


    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 hea...

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

  15. 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;


    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 not m...

  16. The history of molded fiber packaging: a 20th century pulp story

    NARCIS (Netherlands)

    Wever, R.; Twede, D.


    Molded fiber packaging, which is also referred to as molded pulp packaging, has been around for a little over a hundred years now. From the first patent, dating from 1903, until approximately 25 years ago molded fiber packaging was a niche product used mainly for packing eggs. However, in the last t

  17. 40 CFR Appendix - Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC... (United States)


    ... 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...

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

    DEFF Research Database (Denmark)

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


    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...... to the polymer part was mainly influenced by packing pressure level and distance from the gate....

  19. On the Injection Molding of Nanostructured Polymer Surfaces

    DEFF Research Database (Denmark)

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


    Well-defined nano-topographies were prepared by electron-beam lithography and electroplated to form nickelshims. The surface pattern consisted of square pillars repeated equidistantly within the plane of the surface in a perpendicular arrangement. The width and distance between the squares both...... mold sub-micrometer surface structures in polymers mainly relates to adhesive energy between polymer and shim....

  20. QTLs for Snow Mold Disease Resistance in Creeping Bentgrass (United States)

    Snow molds caused by Typhula spp. are the most economically important winter diseases of turfgrass in the northern and alpine regions of the United States and Canada. During winter, the psychrophilic pathogens take advantage of the weakened host plants at low temperatures under persistent snow cover...

  1. Metal Injection Molding of Alloy 718 for Aerospace Applications (United States)

    Ott, Eric A.; Peretti, Michael W.


    The metal injection molding process, used in the automotive, medical, and consumer markets for several decades, was investigated for application to superalloys for small, complex-shaped, aerospace components. With sufficient control on processing, inclusion risks, and chemistry, the process can successfully be applied to superalloy 718 components. Assessments included tensile and fatigue property evaluation, characterization of microstructure, and development of an AMS specification.

  2. Engineering Design Handbook Rotational Molding of Plastic Powders (United States)


    nozzle make up the facility for liquid honing for finishing molds. If pickling is desired, acid and water tanks, and a small heating system are all...pigments or filler materials. Certain pigments such as carbon black and titanium dioxide (white) are very hard to disperse by dry blending. Low

  3. Advanced Polymer Composite Molding Through Intelligent Process Analysis and Control (United States)


    In this project. process analysis of Resin Transfer Molding (RTM) was carried out and adaptive process control models were developed. In addition, a...aforementioned work in three separate sections: (1) process analysis and adaptive control modeling, (2) manufacturing of non-invasive sensor, end (3) list of publications resulting from this project.

  4. Precision glass molding: Toward an optimal fabrication of optical lenses (United States)

    Zhang, Liangchi; Liu, Weidong


    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.

  5. Effective Control of Molds Using a Combination of Nanoparticles (United States)

    Martínez-Castañón, Gabriel Alejandro; Slavin, Yael N.; Zhao, Wayne; Asnis, Jason; Häfeli, Urs O.


    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. PMID:28122038

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

    Energy Technology Data Exchange (ETDEWEB)

    Cech, Jiri [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345E, DK-2800 Kongens Lyngby (Denmark); Taboryski, Rafael, E-mail: [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345E, DK-2800 Kongens Lyngby (Denmark)


    Highlights: Black-Right-Pointing-Pointer We present novel and highly useful results on FDTS monolayer coating of aluminum. Black-Right-Pointing-Pointer The coating is particularly applicable for coating of prototyping injection molding tools, which often are made of Al. Black-Right-Pointing-Pointer 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.

  7. A Recurrent Neural Network for Warpage Prediction in Injection Molding

    Directory of Open Access Journals (Sweden)

    A. Alvarado-Iniesta


    Full Text Available Injection molding is classified as one of the most flexible and economical manufacturing processes with high volumeof plastic molded parts. Causes of variations in the process are related to the vast number of factors acting during aregular production run, which directly impacts the quality of final products. A common quality trouble in finishedproducts is the presence of warpage. Thus, this study aimed to design a system based on recurrent neural networksto predict warpage defects in products manufactured through injection molding. Five process parameters areemployed for being considered to be critical and have a great impact on the warpage of plastic components. Thisstudy used the finite element analysis software Moldflow to simulate the injection molding process to collect data inorder to train and test the recurrent neural network. Recurrent neural networks were used to understand the dynamicsof the process and due to their memorization ability, warpage values might be predicted accurately. Results show thedesigned network works well in prediction tasks, overcoming those predictions generated by feedforward neuralnetworks.

  8. Thermal modeling of wafer-based precision glass molding process (United States)

    Hu, Yang; Shen, Lianguan; Zhou, Jian; Li, Mujun


    Wafer based precision glass optics manufacturing has been an innovative approach for combining high accuracy with mass production. However, due to the small ratio of thickness and diameter of the glass wafer, deformation and residual stress would be induced for the nonuniform temperature distribution in the glass wafer after molding. Therefore, thermal modelling of the heating system in the wafer based precision glass molding (PGM) process is of great importance in optimizing the heating system and the technique of the process. The current paper deals with a transient thermal modelling of a self-developed heating system for wafer based PGM process. First, in order to investigate the effect of radiation from the surface and interior of the glass wafer, the thermal modeling is simulated with a discrete ordinates radiation model in the CFD software FLUENT. Temperature distribution of the glass wafer obtained from the simulations is then used to evaluate the performance of heating system and investigate some importance parameters in the model, such as interior and surface radiation in glass wafer, thermal contact conductance between glass wafer and molds, thickness to diameter ratio of glass wafer. Finally, structure modification in the molding chamber is raised to decrease the temperature gradient in the glass wafer and the effect is significant.

  9. Optimizing biomass blends for manufacturing molded packaging materials using mycelium (United States)

    Polystyrene is one of the most widely used plastics and is commonly produced in three forms: 1) Extruded polystyrene – disposable utensils, CD/DVD cases, yogurt containers, smoke alarm housing, etc.; 2) Expanded polystyrene foam – molded packaging materials and packaging "peanuts"; 3) Extruded polys...

  10. Incipient flocculation molding: A new ceramic-forming technique (United States)

    Arrasmith, Steven Reade

    Incipient Flocculation Molding (IFM) was conceived as a new near-net-shape forming technique for ceramic components. It was hypothesized that the development of a temperature-dependent deflocculant would result in a forming technique that is flexible, efficient, and capable of producing a superior microstructure with improved mechanical properties from highly reactive, submicron ceramic powders. IFM utilizes a concentrated, nonaqueous, sterically stabilized ceramic powder and/or colloidal suspension which is injected into a non-porous mold. The suspension is then flocculated by destabilizing the suspension by lowering the temperature. Flocculation is both rapid and reversible. Cooling to -20°C produces a green body with sufficient strength for removal from the mold. The solvent is removed from the green body by evaporation. The dried green body is subsequently sintered to form a dense ceramic monolith. This is the first ceramic forming method based upon the manipulation of a sterically-stabilized suspension. To demonstrate IFM, the process of grafting polyethylene glycol (PEG), with molecular weights from 600 to 8000, to alumina powders was investigated. The maximum grafted amounts were achieved by the technique of dispersing the alumina powders in molten polymer at 195°C. The ungrafted PEG was then removed by repeated centrifuging and redispersion in fresh distilled water. The rheological behavior of suspensions of the PEG-grafted powders in water, 2-propanol and 2-butanol were characterized. All of the aqueous suspensions were shear thinning. The PEG 4600-grafted alumina powder aqueous suspensions were the most fluid. Sample rods and bars were molded from 52 vol% PEG-grafted alumina suspensions in 2-butanol. The best results were obtained with a preheated aluminum mold lubricated with a fluorinated oil mold-release. The samples were dried, sintered, and their microstructure and density were compared with sintered samples dry pressed from the same alumina powder

  11. Obesity and arterial compliance alterations. (United States)

    Seifalian, Alexander M; Filippatos, Theodosios D; Joshi, Jatin; Mikhailidis, Dimitri P


    Obesity is associated with increased cardiovascular disease (CVD) risk, especially when excess body fat is distributed preferentially within the abdominal region. Obese subjects usually have increased arterial stiffness compared with non-obese subjects of similar age. The factors associated with increased arterial stiffness in obesity include endothelial dysfunction (decreased nitric oxide bioavailability), impaired smooth muscle cell function, insulin resistance, as well as elevated cholesterol and C-peptide levels. Furthermore, visceral fat, the adipose tissue-related renin-angiotensin-aldosterone system and hyperleptinaemia contribute to the obesity-associated impaired arterial compliance. Weight loss improves CVD risk factors and arterial compliance. Because increased arterial stiffness is a marker of CVD risk these findings support the concept that the presence of obesity has vascular implications.

  12. Solidification process and infrared image characteristics of permanent mold castings (United States)

    Viets, Roman; Breuer, Markus; Haferkamp, Heinz; Kruessel, Thomas; Niemeyer, Matthias


    Interdependence between the development of temperature gradients at the solid-liquid interface during solidification of metals and the formation of local defects demands for thermal investigation. In foundry practice thermocouples are used to control the die's overall cooling-rate, but fluctuations in product quality still occur. Capturing FIR- thermograms after opening the die visualizes the state, when most thermal throughput has already flattened the temperature gradients in the mold. Rapid dissipation of heat from liquid metal to the mold during solidification forces further approach of the process investigation by slowing down the heat flux or the use of transparent mold material. Aluminum gravity casting experiments under technical vacuum conditions lead to decelerated solidification by suppression of convection and image sequences containing explicit characteristics that could be assigned to local shrinkage of the casting. Hence relevant clusters are extracted and thermal profiles are drawn from image series, pointing out correlations between feeding performance from the sink heads and the appearance of local defects. Tracing thermal processes in vacuum casting can scarcely be transferred to image data in foundry practice, since only little analogies exist between atmospheric and vacuum casting. The diagnosis of the casting process requires detection of the still closed mold using a transparent silica- aerogel sheet as part of the die. Hereby thermograms of the initial heat input are recorded by adapting a NIR-camera in addition to the FIR-unit. Thus the entire thermal compensation at the joint face for each casting is visualized. This experimental set-up is used for image sequence analysis related to the intermediate casting phases of mold filling, body formation and solidification shrinkage.

  13. Estudio experimental del llenado de moldes pulvimetalúrgicos

    Directory of Open Access Journals (Sweden)

    Istúriz, A.


    Full Text Available Die filling is the first step in the process of powder compaction. The density distribution depends of the powder characteristics and method of filling. In this work we present the first results obtained with different experimental methods of the filling. Results have been analyzed using a video system which permits the observation of the powder flow. The aim of the work is to determinate the effects of size, morphology and nature of the powder, as well as shoe speed, and die geometry on the apparent density distribution in industrial dies of complex geometry.

    En el proceso de conformado pulvimetalúrgico, la consolidación del polvo se inicia con el llenado del molde en el que se fabricará la preforma porosa, el cual está caracterizado por la distribución de densidades del polvo dentro del molde y depende tanto de las propiedades del mismo como del método de llenado utilizado. A continuación, presentamos los primeros resultados obtenidos mediante un montaje experimental que reproduce el llenado de moldes y que, empleando un sistema de video, permite analizar el flujo de las partículas durante el llenado. El objetivo es determinar el efecto del tamaño, naturaleza y morfología del polvo, así como el de la velocidad del cargador y la geometría del molde en la distribución de la densidad aparente en moldes industriales de geometría compleja.

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

    Directory of Open Access Journals (Sweden)

    Fouad Fareh


    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.

  15. Effects of Process Parameters on Replication Accuracy of Microinjection Molded Cyclic Olefins Copolymers Parts (United States)

    Lin, Hsuan-Liang; Chen, Chun-Sheng; Lee, Ruey-Tsung; Chen, Shia-Chung; Chien, Rean-Der; Jeng, Ming-Chang; Hwang, Jiun-Ren


    In this study, the effects of various processing parameters of microinjection molding on the replication accuracy of the micro featured fluidic platform used for DNA/RNA tests are investigated. LIGA-like processes were utilized to prepare a silicon-based SU-8 photoresist, followed by electroforming to make a Ni-Co-based stamp. A cyclic olefin copolymer (COC) was used as the injection molding material. The molding parameters associated with the replication accuracy of micro channel parts were investigated. It was found that for microinjection molded devices, the replication accuracies of the imprint width and depth increase with increasing of mold temperature, melt temperature, injection velocity, and packing pressure.

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

    Directory of Open Access Journals (Sweden)

    S. Medić


    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.

  17. Computer precision simulation for titanium casting centrifugal mold filling of prescision titanium castings

    Directory of Open Access Journals (Sweden)

    Daming XU


    Full Text Available Computer simulation codes were developed based on proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings. Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings unde a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section prcision castings.

  18. Investigation of micro-injection molding based on longitudinal ultrasonic vibration core. (United States)

    Qiu, Zhongjun; Yang, Xue; Zheng, Hui; Gao, Shan; Fang, Fengzhou


    An ultrasound-assisted micro-injection molding method is proposed to improve the rheological behavior of the polymer melt radically, and a micro-injection molding system based on a longitudinal ultrasonic vibration core is developed and employed in the micro-injection molding process of Fresnel lenses. The verification experiments show that the filling mold area of the polymer melt is increased by 6.08% to 19.12%, and the symmetric deviation of the Fresnel lens is improved 15.62% on average. This method improved the filling performance and replication quality of the polymer melt in the injection molding process effectively.

  19. Temperature and Thermal Stress Distribution for Metal Mold in Squeeze Casting Process

    Institute of Scientific and Technical Information of China (English)

    K.H.Chang; G.C.Jang; C.H.Lee; S.H.Lee


    In the squeeze casting process, loaded high pressure (over approximately 100 MPa) and high temperature influence the thermo-mechanical behavior and performance of the used metal mold. Therefore, to safely maintain the metal molds, the thermo-mechanical characteristics (temperature and thermal stress) of metal mold in the squeeze casting must be investigated. In this paper, temperature and thermal stress distribution of steel mold in squeeze casting process were investigated by using a three-dimensional non-steady heat conduction analysis and a three-dimensional thermal elastic-plastic analysis considering temperature-dependent thermo- physical and mechanical properties of the steel mold.

  20. Effects of centrifugal and Coriolis forces on the mold-filling behavior of titanium melts in vertically rotating molds

    Institute of Scientific and Technical Information of China (English)

    Xu Daming; Jia Limin; Fu Hengzhi


    The vertical centrifugal-casting technique is widely used in the manufacture of various irregularly-shaped castings of advanced structural alloys with thin walls, complex shapes and/or large sizes. These castings are used in the increasing applications in aero-space/aviation industries, human teeth/bone repairs with near-net shaped components, etc. In a vertically rotating casting system, the mold-filling processes of alloy melts, coupled with solidification-heat transfer, may be much more complicated, because they are driven simultaneously by gravity, centrifugal and Codolis forces. In the present work, an N-S/VOF-equations-based model, solved using a SOLA-VOF algorithm, under a rotating coordinate system was applied to numerically investigate the impacts of centrifugal and Coriolis forces on metallic melt mold-filling processes in different vertical centrifugal-casting configurations with different mold-rotation rates using an authors' computer-codes system. The computational results show that the Coriolis force may cause remarkable variations in the flow patterns in the casting-part-cavities of a large horizontal-section area and directly connected to the sprue via a short ingate in a vertical centrifugal-casting process. A "turn-back" mold-filling technique, which only takes advantage of the centrifugal force in a transient rotating melt system, has been confirmed to be a rational centrifugal-casting process in order to achieve smooth and layer-by-layer casting-cavities-filling control. The simulated mold-filling processes of Ti-6Al-4V alloy melt, in a vertical centrifugal-casting system with horizontally-connected plate-casting cavities, show reasonable agreement with experimental results from the literature.

  1. Precision molding of advanced glass optics: innovative production technology for lens arrays and free form optics (United States)

    Pongs, Guido; Bresseler, Bernd; Bergs, Thomas; Menke, Gert


    Today isothermal precision molding of imaging glass optics has become a widely applied and integrated production technology in the optical industry. Especially in consumer electronics (e.g. digital cameras, mobile phones, Blu-ray) a lot of optical systems contain rotationally symmetrical aspherical lenses produced by precision glass molding. But due to higher demands on complexity and miniaturization of optical elements the established process chain for precision glass molding is not sufficient enough. Wafer based molding processes for glass optics manufacturing become more and more interesting for mobile phone applications. Also cylindrical lens arrays can be used in high power laser systems. The usage of unsymmetrical free-form optics allows an increase of efficiency in optical laser systems. Aixtooling is working on different aspects in the fields of mold manufacturing technologies and molding processes for extremely high complex optical components. In terms of array molding technologies, Aixtooling has developed a manufacturing technology for the ultra-precision machining of carbide molds together with European partners. The development covers the machining of multi lens arrays as well as cylindrical lens arrays. The biggest challenge is the molding of complex free-form optics having no symmetrical axis. A comprehensive CAD/CAM data management along the entire process chain is essential to reach high accuracies on the molded lenses. Within a national funded project Aixtooling is working on a consistent data handling procedure in the process chain for precision molding of free-form optics.


    Institute of Scientific and Technical Information of China (English)

    X.S. Zheng; M.H. Sha; J.Z. Jin


    Mold is the heart of the continuous casting machine. Heat transfer and solidification in a watercooled mold are the most important factors during the continuous casting of steel. For studying the temperature distribution of a mold wall, a simulated apparatus of mold was designed and experiments were performed by it. The measured results indicated that the mold wall temperature approaches the temperature of cooling-water. An equivalent thermal-conductivity coefficient was proposed and deduced on the basis of the conclusion of the experiments. This coefficient was applied to solve the heat transfer between the melt and cooling water, and to characterize the heat transfer capacity of the mold. By this equivalent thermal-conductivity coefficient, it is very easy and convenient to numerically simulate the solidification process of continuous casting. And the calculation results are in agreement with the experiments. The effects of casting speed and water flow rate on the mold temperature field were also discussed.

  3. Analysis of the origin of periodic oscillatory flow in the continuous casting mold (United States)

    Lee, Jun-young; Kim, Yong-tae; Yi, Kyung-woo


    It is very important to understand flow patterns within the continuous casting mold because they have a significant impact on product quality. Water model experiment and particle image velocimetry were conducted to identify the fluid flow pattern in the steel slab continuous casting mold. The fluid flow pattern in the mold is not steady but instead an oscillatory flow with a specific oscillation frequencies. Many studies have been reported about oscillatory flow within the mold. However, these studies do not provide a clear explanation of physical origin of oscillatory flow. We identified the physical origins of various specific oscillation frequencies, and confirmed through experimentation and simulation that each frequency is related to the cross flow and injection stream oscillation. Moreover, the degree of oscillation at each frequency appears differently depending on the location within the mold, and is shown to have a effect near the mold wall. These results provide a better understanding of complex oscillatory flow patterns within the mold.

  4. Modeling and flow analysis of pure nylon polymer for injection molding process (United States)

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


    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.

  5. Fiber Reinforcement in Injection Molded Nylon 6/6 Spur Gears (United States)

    Senthilvelan, S.; Gnanamoorthy, R.


    Injection molded polymer composite gears are being used in many power and or motion transmission applications. In order to widen the utilization of reinforced polymers for precision motion transmission and noise less applications, the accuracy of molded gears should be increased. Since the injection molded gear accuracy is significantly influenced by the material shrinkage behaviour, there is a need to understand the influence of fiber orientation and gate location on part shrinkage behaviour and hence the gear accuracy. Unreinforced and 20% short glass fiber reinforced Nylon 6/6 spur gears were injection molded in the laboratory and computer aided simulations of gear manufacturing was also carried out. Results of the mold flow simulation of gear manufacturing were correlated with the actual fiber orientation and measured major geometrical parameters of the molded gears. Actual orientation of the fibers near the tooth profile, weld line region and injection points of molded gears were observed using optical microscope and correlated with predicted fiber orientation.


    Institute of Scientific and Technical Information of China (English)

    G.J. Xu; D.H. Li; J.C. He


    In order to know the distribution of magnetic field in a novel flow control of mold(NFC Mold) and to provide the experimental data for the electromagnetic structuredesign and the analysis of flow control in continuous casting mold, the magnetic fieldin a NFC Mold were measured by Tesla meter of Model CT-3. The method of vectorsynthesis was adopted in the measurement of magnetic fields. The results showed thatthe magnetic field in the NFC Mold was composed of two main magnetic areas thatwere symmetrical. Although there was leaking magnetic flux between the lower surfaceof the upper pole and the upper surface of the lower pole on the sides, it was restrainedby the main magnetic fields effectively. Therefore the NFC Mold was more preferablysatisfied to be used in controlling the molten steel flow in continuous casting mold.

  7. Increasing the life of molds for casting copper and its alloys (United States)

    Smirnov, A. N.; Spiridonov, D. V.


    The work of the molds intended for casting copper and copper alloys in semicontinuous casters for producing flat billets is considered. It is shown that, to increase the resistance of mold plates, the inner space of the mold should have a taper shape toward the casting direction and take into account the shrinkage of the linear dimensions of the ingot during its motion in the mold. The taper shape increases the intensity and uniformity of heat removal due to close contact between the ingot and the mold inner surface. Testing of new design molds under industrial conditions demonstrates that their resistance increases by a factor of 4.0-4.5. The taper effect of the mold plates is much more pronounced in their narrow faces.

  8. Composite materials molding simulation for purpose of automotive industry (United States)

    Grabowski, Ł.; Baier, A.; Majzner, M.; Sobek, M.


    Composite materials loom large increasingly important role in the overall industry. Composite material have a special role in the ever-evolving automotive industry. Every year the composite materials are used in a growing number of elements included in the cars construction. Development requires the search for ever new applications of composite materials in areas where previously were used only metal materials. Requirements for modern solutions, such as reducing the weight of vehicles, the required strength and vibration damping characteristics go hand in hand with the properties of modern composite materials. The designers faced the challenge of the use of modern composite materials in the construction of bodies of power steering systems in vehicles. The initial choice of method for producing composite bodies was the method of molding injection of composite material. Molding injection of polymeric materials is a widely known and used for many years, but the molding injection of composite materials is a relatively new issue, innovative, it is not very common and is characterized by different conditions, parameters and properties in relation to the classical method. Therefore, for the purpose of selecting the appropriate composite material for injection for the body of power steering system computer analysis using Siemens NX 10.0 environment, including Moldex 3d and EasyFill Advanced tool to simulate the injection of materials from the group of possible solutions were carried out. Analyses were carried out on a model of a modernized wheel case of power steering system. During analysis, input parameters, such as temperature, pressure injectors, temperature charts have been analysed. An important part of the analysis was to analyse the propagation of material inside the mold during injection, so that allowed to determine the shape formability and the existence of possible imperfections of shapes and locations air traps. A very important parameter received from

  9. Influence of mold and substrate material combinations on nanoimprint lithography process: MD simulation approach (United States)

    Yang, Seunghwa; Yu, Suyoung; Cho, Maenghyo


    A molecular dynamics (MD) study was performed to examine the effect of mold-substrate material composition on the pattern transferring and defects of the resist polymer in a thermal Nano Imprint Lithography (NIL) process. As candidate materials, single crystalline nickel (Ni), silicon (Si) and silica (SiO2, α-quartz) for the rigid mold substrate, and amorphous poly-(methylmethacrylate) (PMMA) thin film for the resist were considered for common applications in NIL processes. Three different material compositions of Si mold-Ni substrate, Ni mold-Si substrate, and quartz mold-Ni substrate were considered. In accordance with a real NIL process, a sequence of indentation-relaxation-release processes was quasi-statically simulated using isothermal ensemble simulation on tri-layer molecular structures consisting of a mold, resist, and substrate. To correlate the deformed shape and delamination of PMMA resist from the substrate in indentation and release processes, non-bond interaction energy between a rigid mold and resist was calculated for each combination of mold and substrate materials. The Si mold-Ni substrate combination shows successful pattern transfer to the resist polymer even without an anti-sticking layer as a result of the desirable balance of surface free energy for mold and substrate materials. However, Ni mold-Si substrate combination shows a critical delamination of the resist in the release process due to strong van der Waals adhesion between the resist and Ni mold. Similarly, the quartz mold-Ni substrate combination shows the same delamination in pattern transfer, but the adhesion of the resist to the quartz mold is attributed to electrostatic interaction. In order to provide guidelines for material selection in imprint-like processes where surface adsorption and wetting characteristics are critical design parameters, a simple PMMA-rigid plate model is proposed, with which consistent surface interaction characteristics in the full model NIL process

  10. Monitoring managers through corporate compliance programs


    Angelucci, C.; Han, M.A.


    Compliance programs entail monitoring of employees' behavior with the claimed objective of fighting corporate crime. (Competition) Authorities promote such intra-firm monitoring. In a three-tier hierarchy model, authority-shareholder-manager, we study the impact of monitoring through a compliance program on contracting within the firm and the authority's optimal sanctions and leniency policy. We find that compliance programs are beneficial in the fight against corporate crime if and only if t...

  11. Internal compliance investigations can reduce government sanctions. (United States)

    Mustokoff, M M; Yecies, M S


    An effective corporate compliance program is facilitated by three essential elements: a well-qualified compliance officer; a policy of immediate investigation of every report of potential fraud and abuse; and clearly defined roles for both corporate and outside counsel in conducting the investigations. A government agency is less likely to exercise the full extent of its powers when these elements are in place and three is evidence of a sincere compliance effort.

  12. Route 20, Autobahn 7, and Slime Mold: Approximating the Longest Roads in USA and Germany With Slime Mold on 3-D Terrains. (United States)

    Adamatzky, Andrew I


    A cellular slime mould Physarum polycephalum is a monstrously large single cell visible by an unaided eye. The slime mold explores space in parallel, is guided by gradients of chemoattractants, and propagates toward sources of nutrients along nearly shortest paths. The slime mold is a living prototype of amorphous biological computers and robotic devices capable of solving a range of tasks of graph optimization and computational geometry. When presented with a distribution of nutrients, the slime mold spans the sources of nutrients with a network of protoplasmic tubes. This protoplasmic network matches a network of major transport routes of a country when configuration of major urban areas is represented by nutrients. A transport route connecting two cities should ideally be a shortest path, and this is usually the case in computer simulations and laboratory experiments with flat substrates. What searching strategies does the slime mold adopt when exploring 3-D terrains? How are optimal and transport routes approximated by protoplasmic tubes? Do the routes built by the slime mold on 3-D terrain match real-world transport routes? To answer these questions, we conducted pioneer laboratory experiments with Nylon terrains of USA and Germany. We used the slime mold to approximate route 20, the longest road in USA, and autobahn 7, the longest national motorway in Europe. We found that slime mold builds longer transport routes on 3-D terrains, compared to flat substrates yet sufficiently approximates man-made transport routes studied. We demonstrate that nutrients placed in destination sites affect performance of slime mold, and show how the mold navigates around elevations. In cellular automaton models of the slime mold, we have shown variability of the protoplasmic routes might depends on physiological states of the slime mold. Results presented will contribute toward development of novel algorithms for sensorial fusion, information processing, and decision making, and

  13. Motivation for Compliance with Environmental Regulation

    DEFF Research Database (Denmark)

    Winter, Søren; May, Peter J.


    A combination of calculated, normative, and social motivations as well as awareness of rules and capacity to comply are thought to foster compliance with regulations. Hypotheses about these factors were tested with data concerning Danish farmers’ compliance with agro-environmental regulations....... Three key findings emerge: that farmers’ awareness of rules plays a critical role; that normative and social motivations are as influential as calculated motivations in enhancing compliance; and that inspectors’ enforcement style affects compliance differently from that posited in much of the literature...

  14. EPA Enforcement and Compliance History Online (United States)

    U.S. Environmental Protection Agency — The Environmental Protection Agency's Enforcement and Compliance History Online (ECHO) website provides customizable and downloadable information about environmental...

  15. Strategies for Addressing Spreadsheet Compliance Challenges

    CERN Document Server

    Weber, Brandon


    Most organizations today use spreadsheets in some form or another to support critical business processes. However the financial resources, and developmental rigor dedicated to them are often minor in comparison to other enterprise technology. The increasing focus on achieving regulatory and other forms of compliance over key technology assets has made it clear that organizations must regard spreadsheets as an enterprise resource and account for them when developing an overall compliance strategy. This paper provides the reader with a set of practical strategies for addressing spreadsheet compliance from an organizational perspective. It then presents capabilities offered in the 2007 Microsoft Office System which can be used to help customers address compliance challenges.

  16. Theory of Regulatory Compliance for Requirements Engineering

    CERN Document Server

    Jureta, Ivan; Mylopoulos, John; Perini, Anna; Susi, Angelo


    Regulatory compliance is increasingly being addressed in the practice of requirements engineering as a main stream concern. This paper points out a gap in the theoretical foundations of regulatory compliance, and presents a theory that states (i) what it means for requirements to be compliant, (ii) the compliance problem, i.e., the problem that the engineer should resolve in order to verify whether requirements are compliant, and (iii) testable hypotheses (predictions) about how compliance of requirements is verified. The theory is instantiated by presenting a requirements engineering framework that implements its principles, and is exemplified on a real-world case study.

  17. Federal government expands compliance initiatives. (United States)

    Dugan, J K


    In 1995, the Federal government initiated Operation Restore Trust to increase enforcement of fraud and abuse regulations in Medicare and Medicaid programs. With the success of the original initiative, the government is expanding the project to additional states and program areas. The initial scrutiny of home health agencies, nursing homes, hospice care, and durable medical equipment is being expanded to managed care plans and acute care hospitals with an eye toward DRG creep. To manage this increased enforcement activity, healthcare organizations should institute comprehensive corporate compliance programs. Such programs should provide a framework that delineates responsibilities and provides a systematic means to resolve issues in a timely manner.

  18. Comparison of three methods of DNA extraction in endocervical specimens for Chlamydia trachomatis infection by spectrophotometry, agarose gel, and PCR. (United States)

    Jenab, Anahita; Roghanian, Rasoul; Golbang, Naser; Golbang, Pouran; Chamani-Tabriz, Leili


    Chlamydia trachomatis is the major cause of sexually transmitted disease in the world. The aim of this study was to determine the best method of DNA extraction for detecting C. trachomatis by polymerase chain reaction (PCR) in sexually active women (n = 80) attending Shahid Beheshti Hospital in Isfahan, Iran. Endocervical swabs were collected from 80 women, 22 of whom were asymptomatic and 58 symptomatic. Three different DNA extraction methods were used in this study (phenol-chlorophorm, proteinase K, and boiling). DNA yield was evaluated by spectrophotometry, agarose gel, and PCR. The internal control was assayed by beta-globin primers (PCO4, GH20). The DNA cryptic plasmid was selected as the target for C. trachomatis and samples were examined by PCR using specific KL1 and KL2 primers. It was shown that DNA extraction by boiling was the most sensitive with the highest yield of DNA. Of the 80 samples, 17 (21.25%) showed positivity for C. trachomatis by PCR. The highest rate of C. trachomatis infection was found in the group aged between 35 and 45 years old and those who used withdrawal or an intrauterine device as methods of contraception. It was demonstrated that DNA extraction by boiling was the least expensive and a very rapid method that gave the highest DNA yield. The infection rate in the sexually active women, including symptomatic and asymptomatic, was 21.25%, with a presumably high prevalence compared with other studies done in this field.

  19. Agarose cell block technique as a complementary method in the diagnosis of fungal osteomyelitis in a dog

    Directory of Open Access Journals (Sweden)

    N.S. Rocha


    Full Text Available A 7-year-old Labrador Retriever female dog presenting left forelimb lameness for one day was admitted to the Veterinary Hospital (UNESP-Botucatu for clinical evaluation. Several tests, including blood and image analysis, microbiological culture and cytology of lytic areas of affected bone were made in order to establish a diagnosis. Serum biochemical profile revealed increased levels of liver enzymes, plasma globulin, creatine kinase (CK and calcium. Hemogram revealed anemia and leukocytosis; left humerus image analysis revealed an osteolytic lesion and cytology revealed a suppurative periostitis. Differential diagnosis was a nonspecific infectious inflammatory process or osteosarcoma. Since it was not possible to achieve a definitive diagnosis and there was a highly suspicious for an infectious agent, an agarose cell block of the bone marrow fine-needle aspiration was made. The cytological examination of cell block presented similar findings as described previously. However, additional stains including periodic acid-Schiff (PAS were positive for fungal hyphae, which rendered a diagnosis of fungal osteomyelitis due to Aspergillus spp. This case report illustrates an uncommon cause of osteomyelitis for breed that was diagnosed by an underused method in veterinary medicine.

  20. BDNF gene delivery within and beyond templated agarose multi-channel guidance scaffolds enhances peripheral nerve regeneration (United States)

    Gao, Mingyong; Lu, Paul; Lynam, Dan; Bednark, Bridget; Campana, W. Marie; Sakamoto, Jeff; Tuszynski, Mark


    Objective. We combined implantation of multi-channel templated agarose scaffolds with growth factor gene delivery to examine whether this combinatorial treatment can enhance peripheral axonal regeneration through long sciatic nerve gaps. Approach. 15 mm long scaffolds were templated into highly organized, strictly linear channels, mimicking the linear organization of natural nerves into fascicles of related function. Scaffolds were filled with syngeneic bone marrow stromal cells (MSCs) secreting the growth factor brain derived neurotrophic factor (BDNF), and lentiviral vectors expressing BDNF were injected into the sciatic nerve segment distal to the scaffold implantation site. Main results. Twelve weeks after injury, scaffolds supported highly linear regeneration of host axons across the 15 mm lesion gap. The incorporation of BDNF-secreting cells into scaffolds significantly increased axonal regeneration, and additional injection of viral vectors expressing BDNF into the distal segment of the transected nerve significantly enhanced axonal regeneration beyond the lesion. Significance. Combinatorial treatment with multichannel bioengineered scaffolds and distal growth factor delivery significantly improves peripheral nerve repair, rivaling the gold standard of autografts.

  1. Preparation of Ti-Mo getters by injection molding

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhenmei; WEI Xiuying; XIONG Yuhua; MAO Changhui


    Ti-Mo getters have been fabricated via metal injection molding (MIM) using three kinds of Ti powders with different mean particle sizes of 46 μm, 35 μm and 26 μm, respectively. The surface morphology, porosity, and hydrogen sorption properties of Ti-Mo getters formed by MIM using paraffin wax as a principal binder constituent were examined. It has been proven that the powder injection molding is a viable forming technique for porous Ti-Mo getter. The particle size of Ti powders and the powder loading influence the porosity of getters, and this affects the sorption capacity of Ti-Mo getters. Ti-Mo getters produced with the Ti powders possessing a mean particle size of 35 μm using a powder loading of 40 vol.% have a high porosity, resulting in a good sorption capacity.

  2. FPGA-Based Multiprocessor System for Injection Molding Control

    Directory of Open Access Journals (Sweden)

    Roque A. Osornio-Rios


    Full Text Available The plastic industry is a very important manufacturing sector and injection molding is a widely used forming method in that industry. The contribution of this work is the development of a strategy to retrofit control of an injection molding machine based on an embedded system microprocessors sensor network on a field programmable gate array (FPGA device. Six types of embedded processors are included in the system: a smart-sensor processor, a micro fuzzy logic controller, a programmable logic controller, a system manager, an IO processor and a communication processor. Temperature, pressure and position are controlled by the proposed system and experimentation results show its feasibility and robustness. As validation of the present work, a particular sample was successfully injected.

  3. Surviving freezing in plant tissues by oomycetous snow molds. (United States)

    Murakami, Ryo; Yajima, Yuka; Kida, Ken-ichi; Tokura, Katsuyuki; Tojo, Motoaki; Hoshino, Tamotsu


    Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling and freezing temperatures than other snow mold taxa. However, Pythium species are often found to be pathogenic on mosses in Polar Regions. We investigated the frost resistance of Pythium species from Temperate (Hokkaido, Japan) and Subantarctic Regions. Free mycelia and hyphal swellings, structures for survival, of Pythium iwayamai and Pythium paddicum lost viability within freeze-thaw 3 cycles; however, mycelia in host plants survived the treatment. It was reported that fungi in permafrost are characterized both by the presence of natural cryoprotectants in these ecotopes and by the ability to utilize their inherent mechanisms of protection. It is conceivable that plant substrates or derivatives thereof are natural cryoprotectants, enabling them to provide advantageous conditions to microorganisms under freezing conditions. Our results are the first to experimentally support this hypothesis.

  4. Pressureless sintering behavior of injection molded alumina ceramics

    Directory of Open Access Journals (Sweden)

    Liu W.


    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.

  5. Characteristics of shell thickness in a slab continuous casting mold

    Institute of Scientific and Technical Information of China (English)

    Di-feng Wu; Shu-sen Cheng; Zi-jian Cheng


    The key to reduce shell breakout in the continuous casting process is to control shell thickness in the mold.A numerical simulation on the turbulent flow and heat transfer coupled with solidification in the slab mold using the volume of fluid (VOF) model and the enthalpy-porosity scheme was conducted and the emphasis was put upon the flow effect on the shell thickness profiles in longitudinal and transverse directions.The results show that the jet acts a stronger impingement on the shell of narrow face,which causes a zero-increase of shell thickness in a certain range near the impingement point.The thinnest shell on the slab cross-section locates primarily in the center of the narrow face,and secondly near the comer of the wide face.Nozzle optimization can obviously increase the shell thickness and make it more uniform.

  6. Injection molded polymeric hard X-ray lenses

    DEFF Research Database (Denmark)

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


    A novel and economical approach for fabricating compound refractive lenses for the purpose of focusing hard X-rays is described. A silicon master was manufactured by UV-lithography and deep reactive ion etching (DRIE). Sacrificial structures were utilized, which enabled accurate control of the et......A novel and economical approach for fabricating compound refractive lenses for the purpose of focusing hard X-rays is described. A silicon master was manufactured by UV-lithography and deep reactive ion etching (DRIE). Sacrificial structures were utilized, which enabled accurate control...... 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...

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

    CERN Document Server

    Riemer, Oltmann; Gläbe, Ralf


    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...

  8. 40 CFR 160.12 - Statement of compliance or non-compliance. (United States)


    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Statement of compliance or non-compliance. 160.12 Section 160.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... non-compliance. Any person who submits to EPA an application for a research or marketing permit...

  9. Tackification of textile preforms for resin transfer molding

    Institute of Scientific and Technical Information of China (English)

    Wuyunqiqige; YI; Xiao-su


    Tackified textile fiber preforms are used widely in resin transfer molding (RTM) to produce aerospace-grade composite parts. In the present study, a new tackifier was developed to improve RTM laminate performance. The influence of tackifier concentration on spring back, thermal properties and mechanical performance was studied . It has showed that the new tackifier was compatible with the matrix resin and improved the textile handling ability; the ILSS was slightly increased without decreasing of thermal properties, modulus and flexural strength.

  10. Presurgical nasoalveolar molding in unilateral cleft lip and palate

    Directory of Open Access Journals (Sweden)

    Rahul J Hegde


    Full Text Available Unilateral cleft lip and palate (UCLP patients have an esthetic and functional compromise of the middle third of the face and nasal structures. To improve the esthetic result of lip repair, the concept of presurgical nasoalveolar molding (PNAM was brought into conception. PNAM is an easy and passive method of bringing the alveolus and lips together by redirecting the forces of natural growth. This case report documents a 2-year follow-up of PNAM in UCLP.

  11. Numerical Simulation and Water Analog of Mold Filling Processes

    Institute of Scientific and Technical Information of China (English)


    This paper demonstrates the potential of a computer code, developed by the authors, in shaping gating systems by modeling the fluid flow phenomena through a complex gating system during mold filling. A plate casting with dimension 200 mm×200 mm×50 mm was chosen as the verifying problem. Water analog studies were carried out on this casting. The comparison indicates that computer simulation could be a powerful tool in shaping gating systems.

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

    Energy Technology Data Exchange (ETDEWEB)

    Professor R. D. Pehlke, Principal Investigator, Dr. John M. Cookson, Dr. Shouwei Hao, Dr. Prasad Krishna, Kevin T. Bilkey


    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.

  13. Agarose-chitosan-C18 film micro-solid phase extraction combined with high performance liquid chromatography for the determination of phenanthrene and pyrene in chrysanthemum tea samples. (United States)

    Ng, Nyuk Ting; Sanagi, Mohd Marsin; Wan Ibrahim, Wan Nazihah; Wan Ibrahim, Wan Aini


    Agarose-chitosan-immobilized octadecylsilyl-silica (C18) film micro-solid phase extraction (μSPE) was developed and applied for the determination of phenanthrene (PHE) and pyrene (PYR) in chrysanthemum tea samples using high performance liquid chromatography-ultraviolet detection (HPLC-UV). The film of blended agarose and chitosan allows good dispersion of C18, prevents the leaching of C18 during application and enhances the film mechanical stability. Important μSPE parameters were optimized including amount of sorbent loading, extraction time, desorption solvent and desorption time. The matrix match calibration curves showed good linearity (r⩾0.994) over a concentration range of 1-500ppb. Under the optimized conditions, the proposed method showed good limits of detection (0.549-0.673ppb), good analyte recoveries (100.8-105.99%) and good reproducibilities (RSDs⩽13.53%, n=3) with preconcentration factors of 4 and 72 for PHE and PYR, respectively.

  14. Culture phases, cytotoxicity and protein expressions of agarose hydrogel induced Sp2/0, A549, MCF-7 cell line 3D cultures. (United States)

    Ravi, Maddaly; Kaviya, S R; Paramesh, V


    Advancements in cell cultures are occurring at a rapid pace, an important direction is culturing cells in 3D conditions. We demonstrate the usefulness of agarose hydrogels in obtaining 3 dimensional aggregates of three cell lines, A549, MCF-7 and Sp2/0. The differences in culture phases, susceptibility to cisplatin-induced cytotoxicity are studied. Also, the 3D aggregates of the three cell lines were reverted into 2D cultures and the protein profile differences among the 2D, 3D and revert cultures were studied. The analysis of protein profile differences using UniProt data base further augment the usefulness of agarose hydrogels for obtaining 3D cell cultures.

  15. Occurrence of Foodborne Pathogens and Molds in Turkish Foods

    Directory of Open Access Journals (Sweden)

    Sebnem Ozturkogu-Budak


    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.

  16. Characterization of mold and moisture indicators in the home. (United States)

    Mahooti-Brooks, Negar; Storey, Eileen; Yang, Chin; Simcox, Nancy J; Turner, William; Hodgson, Michael


    As studies increasingly support the presence of health risks associated with mold and moisture, understanding fungal concentrations and physical measurements as they relate to the microenvironment becomes more important. We conducted a cross-sectional study in the homes of 64 subjects. The primary objective of this study was to use trained inspectors' list of indicators in rooms (bathroom, bedroom, and basement) and determine whether these indicators are associated with higher fungal levels or physical measurements. A new category for combining the concentrations of fungal species, referred to as moisture indicator fungi (MIF), is used in the analysis. Our results show that basements with a musty odor, efflorescence, water sources, or mold have a two- to threefold increase in fungal concentrations over basements without these indicators. The regression model for the basement was highly predictive of indoor MIF concentrations (r2 = .446, p = .017). Basement water sources are substantial predictors of indoor total fungi, MIF, and Aspergillus/Penicillium spp. MIF concentrations are higher in homes with basement water sources, and most notably, the increase in MIF concentrations is significant in other living spaces (bathroom and bedroom) of the dwelling. Basement water sources are important moisture/mold indicators for epidemiologists to use in exposure assessments performed in residential dwellings.

  17. Influence of the Mold Current on the Electroslag Remelting Process (United States)

    Hugo, Mathilde; Dussoubs, Bernard; Jardy, Alain; Escaffre, Jessica; Poisson, Henri


    The electroslag remelting process is widely used to produce high value-added alloys. The use of numerical simulation has proven to be a valuable way to improve its understanding. In collaboration with Aubert & Duval, the Institute Jean Lamour has developed a numerical transient model of the process. The consumable electrode is remelted within a mold assumed to be electrically insulated by the solidified slag skin. However, this assumption has been challenged by some recent studies: the solidified slag skin may actually allow a part of the melting current to reach the mold. In this paper, the evolution of our model, in order to take into account this possibility, is presented and discussed. Numerical results are compared with experimental data, while several sensitivity studies show the influence of some slag properties and operating parameters on the quality of the ingot. Even, a weakly conductive solidified slag skin at the inner surface of the mold may be responsible for a non-negligible amount of current circulating between the slag and crucible, which in turn modifies the fluid flow and heat transfer in the slag and ingot liquid pool. The fraction of current concerned depends mainly on the electrical conductivities of both the liquid and solidified slag.

  18. Drag material change in hot runner injection molding

    Institute of Scientific and Technical Information of China (English)

    蒋炳炎; 黄伯云


    Quick material change is often encountered for the different colors or kinds of polymer in hot runner injecting molding process. Time-costing and incompleteness of material change process often affects the quality and productivity of products. In the practical production, multi-injection or white material as the transition material is often adopted for quick material change. Based on the rheological behavior of the new and the previous plastic melt, the researches on the related problems were carried out. The concept of drag material change was originally presented. The physical and mathematical model on the simultaneous flow process of the new and the previous plastic melt in hot runner were built up, which can well explain the influence of the injection speed, pressure, viscosity difference, temperature and mold structure on the drag material change efficiency. When temperature in different position in the mold was increased and adjusted, the viscosity difference between the two kinds of melt can be controlled. Therefore the material change ability can be greatly improved during the whole material change process, getting rid of more and more difficult changing in the late stage.

  19. Modeling injection molding of net-shape active ceramic components.

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Tomas (Gram Inc.); Cote, Raymond O.; Grillet, Anne Mary; Yang, Pin; Hopkins, Matthew Morgan; Noble, David R.; Notz, Patrick K.; Rao, Rekha Ranjana; Halbleib, Laura L.; Castaneda, Jaime N.; Burns, George Robert; Mondy, Lisa Ann; Brooks, Carlton, F.


    To reduce costs and hazardous wastes associated with the production of lead-based active ceramic components, an injection molding process is being investigated to replace the current machining process. Here, lead zirconate titanate (PZT) ceramic particles are suspended in a thermoplastic resin and are injected into a mold and allowed to cool. The part is then bisque fired and sintered to complete the densification process. To help design this new process we use a finite element model to describe the injection molding of the ceramic paste. Flow solutions are obtained using a coupled, finite-element based, Newton-Raphson numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. Thermal, rheological, and wetting properties of the PZT paste are measured for use as input to the model. The viscosity of the PZT is highly dependent both on temperature and shear rate. One challenge in modeling the injection process is coming up with appropriate constitutive equations that capture relevant phenomenology without being too computationally complex. For this reason we model the material as a Carreau fluid and a WLF temperature dependence. Two-dimensional (2D) modeling is performed to explore the effects of the shear in isothermal conditions. Results indicate that very low viscosity regions exist near walls and that these results look similar in terms of meniscus shape and fill times to a simple Newtonian constitutive equation at the shear-thinned viscosity for the paste. These results allow us to pick a representative viscosity to use in fully three-dimensional (3D) simulation, which because of numerical complexities are restricted to using a Newtonian constitutive equation. Further 2D modeling at nonisothermal conditions shows that the choice of

  20. Fabrication of Composite Material Using Gettou Fiber by Injection Molding (United States)

    Setsuda, Roy; Fukumoto, Isao; Kanda, Yasuyuki

    This study investigated the mechanical properties of composite using gettou (shell ginger) fiber as reinforcement fabricated from injection molding. Gettou fiber is a natural fiber made from gettou, a subtropical plant that is largely abundant in Okinawa, Japan. We used the stem part of gettou plant and made the gettou fiber by crushing the stem. The composite using gettou fiber contributed to low shrinkage ratio, high bending strength and high flexural modulus. The mechanical strength of composite using long gettou fiber showed higher value than composite using short gettou fiber. Next, because gettou is particularly known for its anti-mold characteristic, we investigated the characteristic in gettou plastic composite. The composite was tested against two molds: aspergillius niger and penicillium funiculosum. The 60% gettou fiber plastic composite was found to satisfy the JISZ2801 criterion. Finally, in order to predict the flexural modulus of composite using gettou fiber by Halpin-Tsai equation, the tensile elastic modulus of single gettou fiber was measured. The tendency of the experimental results of composite using gettou fiber was in good agreement with Halpin-Tsai equation.

  1. Penerapan Standarisasi Desain untuk Meningkatkan Kualitas dan Masa Pakai Mold Di PT. Takagi Sari Multi Utama

    Directory of Open Access Journals (Sweden)

    Andi Widodo


    Full Text Available PT. Takagi Sari Multi Utama adalah perusahaan manufaktur yang bergerak di bidang injeksi plastik untuk produk otomotif terutama pada kendaraan bermotor. Karena begitu banyaknya pelanggan yang mempercayakan produk plastik injectionnya, maka PT. Takagi Sari Multi Utama harus memperhatikan mold yang digunakan sebagai sarana atau alat produksi memiliki kualitas yang tinggi. Karena begitu pentingnya suatu kualitas mold dan daya tahan mold terhadap penjaminan kualitas produksi, maka penulis mencari masalah utama yang terjadi PT. takagi Sari Multi Utama dengan menggunakan diagram pareto. Berdasarkan diagram terebut diperoleh data penyebap kerusakan mold paling tinggi adalah Design and Mold Structur dengan 154 Kejadian. Masalah Design and Mold Structur dipetakan dalam fishbone diagram untuk mengetahui permasalahan apa saja yang menyebapkan. Permasalahan yang ditemukan dilakukan analisa menggunakan FMEA (Failure Mode and Efect Analisis sebagai landasan melakukan perbaikan. Dengan metoda FMEA (Failure Mode and Efect Analisis diperoleh kesimpulan bahwa buruknya desain dan kontruksi mold dikarenakan tidak adanya standar desain yang digunakan sebagai acuhan proses desain dan pemeriksaan mold saat proses manufacturing dengan nilai RPN 567. Oleh karena itu proses perbaikan dilakukan dengan membuat standar desain mold di PT. Takagi Sari Multi Utama kemudian mencoba menerapkannya pada desain mold Cover Side 3/4.

  2. Optimization design of wide face water slots for medium-thick slab casting mold

    Directory of Open Access Journals (Sweden)

    Xue-lin Yin


    Full Text Available A three-dimensional finite-element model has been established to investigate the thermal behavior of the medium-thick slab copper casting mold with different cooling water slot designs. The mold wall temperatures measured using thermocouples buried in different positions of the mold with the original designed cooling system were analyzed to determine the corresponding heat flux profile. This profile was then used for simulation to predict the temperature distribution and the thermal stress distribution of the molds. The predicted temperatures during operation matched the plant measurements. The results showed that the maximum temperature, about 635 K in the wide hot surface, was found about 60 mm below the meniscus and 226 mm from the center of the mold. For the mold with the type I modified design, there was an insignificant decrease in temperature of about 5 K, and for the mold with the type II modified design, the maximum temperature was decreased by about 15 K and the temperature of the hot surface was distributed more uniformly along the length of the mold. The corresponding maximum thermal stress at the hot surface of the mold was reduced from 408 MPa to 386 MPa with the type II modified design. The results indicated that the modified design II is beneficial to the increase of mold life and the quality of casting slabs.

  3. Explaining G20 and BRICS Compliance

    Directory of Open Access Journals (Sweden)

    Marina Larionova


    Full Text Available This article explores the internal and external factors influencing the compliance performance of the Group of 20 (G20 and the BRICS. The authors start with an overview of the G20 and BRICS compliance patterns using comparative data onthe number of commitments made by the two institutions, the level of institutional compliance, and distribution of commitments and compliance across issue areas. G20 compliance is traced since the leaders’ first 2008 summit in Washington. The BRICS compliance performance record includes data since the third stand alone summit in Sanya in 2011.The study then takes stock of compliance catalysts embedded in the summits’ discourse: priority placements, numerical targets, timelines, self-accountability pledges and mandates to implement and/or monitor implementation. The authors review trends in the use of catalysts in different years and issue areas and identify commonalities and differences.The analysis then turns to external causes of compliance and focuses on demand for collective actions and members’ collective power to respond and deliver on their pledges. Here the study explores whether the self-accountability mechanisms created by the institutions in response to the demand for effectiveness and legitimacy facilitate compliance.The article concludes by highlighting catalysts, causes of compliance and their combinations with the greatest power to encourage implementation, explaining trends in G20 and BRICS compliance performance. The data sets on G20 and BRICS differ in terms of scale. The G20 data set contains 1,511 commitments of which 114 have been monitored, and the BRICS data set contains 231 commitments of which 23 have been monitored.

  4. Oral contraceptive compliance during adolescence. (United States)

    Serfaty, D


    A review of the available literature suggests that adolescent lack of compliance with oral contraceptives (OCs) is a multifactorial problem that requires a multifactorial solution. Because of their lack of experience with contraception, higher frequency of intercourse, higher intrinsic fertility, and pattern of frequent stopping or switching of methods, adolescents experience higher OC failure rates than do adult women. Adolescents also are more likely to forget to take the pill or to discontinue due to side effects, without consulting their physician. A survey of European young women identified contraceptive protection without weight gain as the most necessary change in OCs. Adolescents must be counseled not to miss a single pill, observe the pill-free interval, take phasic formulations in the right order, and use a back-up method in case of diarrhea and vomiting or when certain medications (e.g., antibiotics and anti-epileptics) are used concurrently, and be informed of steps to take in the event of side effects and unprotected intercourse. The quality of the counseling appears to be more important to compliance than the quantity of information provided. Pharmacists should complete the counseling initiated by the physician and explain prescription use. The most significant predictor of consistent OC use is the adolescent's motivation.

  5. Environmental mold and mycotoxin exposures elicit specific cytokine and chemokine responses.

    Directory of Open Access Journals (Sweden)

    Jamie H Rosenblum Lichtenstein

    Full Text Available Molds can cause respiratory symptoms and asthma. We sought to use isolated peripheral blood mononuclear cells (PBMCs to understand changes in cytokine and chemokine levels in response to mold and mycotoxin exposures and to link these levels with respiratory symptoms in humans. We did this by utilizing an ex vivo assay approach to differentiate mold-exposed patients and unexposed controls. While circulating plasma chemokine and cytokine levels from these two groups might be similar, we hypothesized that by challenging their isolated white blood cells with mold or mold extracts, we would see a differential chemokine and cytokine release.Peripheral blood mononuclear cells (PBMCs were isolated from blood from 33 patients with a history of mold exposures and from 17 controls. Cultured PBMCs were incubated with the most prominent Stachybotrys chartarum mycotoxin, satratoxin G, or with aqueous mold extract, ionomycin, or media, each with or without PMA. Additional PBMCs were exposed to spores of Aspergillus niger, Cladosporium herbarum and Penicillium chrysogenum. After 18 hours, cytokines and chemokines released into the culture medium were measured by multiplex assay. Clinical histories, physical examinations and pulmonary function tests were also conducted. After ex vivo PBMC exposures to molds or mycotoxins, the chemokine and cytokine profiles from patients with a history of mold exposure were significantly different from those of unexposed controls. In contrast, biomarker profiles from cells exposed to media alone showed no difference between the patients and controls.These findings demonstrate that chronic mold exposures induced changes in inflammatory and immune system responses to specific mold and mycotoxin challenges. These responses can differentiate mold-exposed patients from unexposed controls. This strategy may be a powerful approach to document immune system responsiveness to molds and other inflammation-inducing environmental agents.

  6. Effects of DS-modified agarose gels on neurite extension in 3D scaffold through mechanisms other than changing the pore radius of the gels. (United States)

    Peng, Jin; Pan, Qian; Zhang, Wei; Yang, Hao; Zhou, Xue; Jiang, Hua


    Dermatan sulfate is widely distributed as glycosaminoglycan side chains of proteoglycans, which are the main components of glial scar and inhibit neurite regeneration after nerve injury. However its role in the inhibiting process is not clear. Understanding neurite extension in three-dimensional scaffolds is critical for neural tissue engineering. This study used agarose gels modified with dermatan sulfate as the three-dimensional culture scaffold. We explored structure-function relationship between the three-dimensional scaffold and neurite extension and examined the role of dermatan sulfate on neurite extension in the three-dimensional scaffold. A range of agarose concentrations was used to generate varied gel physical structures and the corresponding neurite extension of embryonic day (E9) chick dorsal root ganglia was examined. We measured gel stiffness and gel pore size to determine whether dermatan sulfate changed the gels' conformation. As gel concentration increased, neurite length and gel pore size decreased, and gel stiffness increased. At 1.00 and 1.25% (wt/vol) concentrations, dermatan sulfates both immobilized with agarose gels and dissolved in culture medium inhibit neurite extension. While at 1.50 and 1.75% (wt/vol) concentrations, only immobilized dermatan sulfate worked. Immobilized dermatan sulfate could modify molecular shape of agarose gels, decrease gel pore size statistically, but did not influence gel stiffness. We have proved that the decrease of gel pore size is insufficient to inhibit neurite extension. These results indicate that dermatan sulfate inhibits neurite extension not through forming a mechanical barrier. Maybe its interaction with neuron membrane is the key factor in neurite extension.

  7. Control on Quality of Molding Sand in Static Pressure Molding Line%静压造型线型砂质量控制

    Institute of Scientific and Technical Information of China (English)

    李锦荣; 令军科; 王新智


    High quantities of addition of core sands to molding sand for multiple products production in our molding line has resulted in deteriorative molding sand and batch defect of metal penetration. After adjusting the addition of sand and mix process, stable properties of molding sand have been obtained and quality problems with molding sand and metal penetration of casting defect effectively resolved.%我公司静压造型线因生产品种多,芯砂流入量大,导致型砂性能恶化,铸件出现批量粘砂;通过调整型砂配比及混制工艺,稳定了型砂性能,有效解决了型砂质量问题和铸件粘砂缺陷.

  8. Heterogeneity of human alpha-fetoprotein (HAFP) as revealed by agarose gel electrophoresis and isoelectric focusing in urea-acrylamide gels

    Energy Technology Data Exchange (ETDEWEB)

    Lester, E. P.; Miller, J. B.; Yachnin, S.


    HAFP was purified from five patients with hepatoma, one with gastric cancer, and one with an embryonal cell tumor, as well as from fetal liver and a monkey tumor cell line grown in tissue culture. The pattern of microheterogeneity of purified HAFP was defined for each HAFP isolate, and was demonstrated to be present in native sera, using crossed immunoelectrophoresis in agarose gels and isoelectric focusing in polyacrylamide gels containing 8 M urea. Three, and in one case four, species were seen in agarose, and were further resolved to reveal 6 major species with isoelectric focusing which could be correlated with the agarose gel variants. We have demonstrated a relationship between the immunosuppressive potency of certain HAFP preparations and the proportion of specific HAFP isomers which they contain as shown by these techniques. We have desialylated each of our preparations and demonstrated that this does not alter immunosuppressive potency but leaves residual complex microheterogeneity. Desialylated HAFP isolates contain six major HAFP isomers by isoelectric focusing, indicating that HAFP heterogeneity is based upon multiple charge differences in the HAFP molecule, apart from sialic acid content. The nature of these charge differences remain to be determined. We postulate that these charge differences modulate the immunosuppressive potency of HAFP.

  9. Agarose film liquid phase microextraction combined with gas chromatography-mass spectrometry for the determination of polycyclic aromatic hydrocarbons in water. (United States)

    Sanagi, Mohd Marsin; Loh, Saw Hong; Wan Ibrahim, Wan Aini; Hasan, Mohamed Noor


    Agarose film liquid phase microextraction (AF-LPME) procedure for the extraction and preconcentration of polycyclic aromatic hydrocarbons (PAHs) in water has been investigated. Agarose film was used for the first time as an interface between donor and acceptor phases in liquid phase microextraction which allowed for selective extraction of the analytes prior to gas chromatography-mass spectrometry. Using 1-octanol as acceptor phase, high enrichment factors in the range of 57-106 for the targeted analytes (fluorene, phenanthrene, fluoranthene and pyrene) were achieved. Under the optimum extraction conditions, the method showed good linearity in the range of 0.1-200 μgL(-1), good correlation coefficients in the range of 0.9963-0.9999, acceptable reproducibility (RSD 6.1-9.2%, n=3), low limits of detection (0.01-0.04 μgL(-1)) and satisfactory relative recoveries (92.9-104.7%). As the AF-LPME device was non-expensive, reuse or recycle of the film was not required, thus eliminating the possibility of analytes carry-over between runs. The AF-LPME technique is environment-friendly and compatible with the green chemistry concept as agarose is biodegradable polysaccharide extracted from seaweed and the procedure requires small volume of organic solvent and generates little waste. The validated method was successfully applied to the analysis of the four analytes in river water samples.

  10. Methods of Automatic Parting Mold and Manual Parting Mold for Injection Mold Design Based on UG%基于UG注射模设计的自动分模和手动分模方法

    Institute of Scientific and Technical Information of China (English)



    UG software is widely applied in plastic injection mold design,the basic principle of parting mold is introduced in this paper,and the UG application in plastic injection mold design is studied with a concrete case.The process of automatic parting mold and manual parting mold in UG are expatiated,the flexible application of two methods will significantly reduce mold design time and greatly improve the efficiency of injection mold design.%UG软件广泛地应用在注射模设计中,本文介绍了分模原理,并结合实例研究UG软件在注射模设计中的应用。介绍了自动分模和手动分模方法,两种方法的灵活应用可以缩短模具设计周期,提高注射模设计的效率。

  11. EPA Enforcement and Compliance History Online: Water Effluent Charts Summaries (United States)

    U.S. Environmental Protection Agency — Summary of compliance status each outfall and parameter for one Clean Water Act discharge permit. Provides the current compliance status and overall compliance...

  12. 41 CFR 60-2.30 - Corporate management compliance evaluations. (United States)


    ... Relating to Public Contracts OFFICE OF FEDERAL CONTRACT COMPLIANCE PROGRAMS, EQUAL EMPLOYMENT OPPORTUNITY, DEPARTMENT OF LABOR 2-AFFIRMATIVE ACTION PROGRAMS Miscellaneous § 60-2.30 Corporate management compliance evaluations. (a) Purpose. Corporate Management Compliance Evaluations are designed to ascertain...

  13. Culture and compliance: an anthropologist’s view


    Sampson, Steven


    The concept of "culture" is often used improperly in the literature and training on business ethics and compliance. A more sophisticated view of 'culture of compliance' is required. Published in a magazine for ethics and compliance professionals

  14. International Criminal Justice and the Politics of Compliance

    NARCIS (Netherlands)

    Lamont, Christopher


    International Criminal Justice and the Politics of Compliance provides a comprehensive study of compliance with legal obligations derived from the International Criminal Tribunal for the former Yugoslavia's (ICTY) Statute and integrates theoretical debates on compliance into international justice sc

  15. 45 CFR 80.6 - Compliance information. (United States)


    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Compliance information. 80.6 Section 80.6 Public... THE CIVIL RIGHTS ACT OF 1964 § 80.6 Compliance information. (a) Cooperation and assistance. The... reports at such times, and in such form and containing such information, as the responsible...

  16. 22 CFR 141.5 - Compliance information. (United States)


    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Compliance information. 141.5 Section 141.5... DEPARTMENT OF STATE-EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 141.5 Compliance information... such information, as a responsible Departmental official or his designee may determine to be...

  17. 40 CFR 52.1335 - Compliance schedules. (United States)


    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Compliance schedules. 52.1335 Section 52.1335 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... Effective date Final compliance date Pilot Knob Pelleting Co Pilot Knob, MO V(10 CSR 10-3.050) Oct. 19,...

  18. Tax Compliance over the Firm Life Course

    NARCIS (Netherlands)

    Stam, F.C.; Verbeeten, F.H.M.


    This article provides a new model of tax compliance over the firm life course, focusing on the dynamics in the underlying motivations and capacities for tax compliance. We review and structure the relevant literature on the early life course of firms: the traditional stages of growth models and a le

  19. 40 CFR 63.403 - Compliance dates. (United States)


    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Compliance dates. 63.403 Section 63.403 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Hazardous Air Pollutants for Industrial Process Cooling Towers § 63.403 Compliance dates. The...

  20. 30 CFR 90.207 - Compliance sampling. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compliance sampling. 90.207 Section 90.207... MANDATORY HEALTH STANDARDS-COAL MINERS WHO HAVE EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.207 Compliance sampling. (a) The operator shall take five valid respirable dust samples...