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Sample records for anterior edge acrylic

  1. Capsulorhexis contraction after cataract surgery: Comparison of sharp anterior edge and modified anterior edge acrylic intraocular lenses

    DEFF Research Database (Denmark)

    Corydon, C.; Lindholt, M.; Knudsen, E.B.

    2007-01-01

    eyes) were included in a prospective randomized study. All had phacoemulsification followed by implantation of an IOL with a modified anterior edge (38 eyes) or a sharp anterior edge (46 eyes). One day (baseline) and 3 months postoperatively, the area of the anterior capsule opening was measured using...... retroillumination photographs. RESULTS: There was a significant reduction in the area of the anterior capsule opening from 1 day to 3 months postoperatively in both groups (Psharp...

  2. Comparison Between Acrylic Cage and Polyetheretherketone (PEEK) Cage in Single-level Anterior Cervical Discectomy and Fusion: A Randomized Clinical Trial.

    Science.gov (United States)

    Farrokhi, Majid R; Nikoo, Zahra; Gholami, Mehrnaz; Hosseini, Khadijeh

    2017-02-01

    Prospective, single-blind randomized-controlled clinical study. To compare polyetheretherketone (PEEK) cage with a novel Acrylic cage to find out which fusion cage yielded better clinical outcomes following single-level anterior cervical discectomy and fusion (ACDF). ACDF is considered a standard neurosurgical treatment for degenerative diseases of cervical intervertebral disks. There are many options, including bone grafts, bone cement, and spacers made of titanium, carbon fiber, and synthetic materials, used to restore physiological disk height and enhance spinal fusion, but the ideal device, which would provide immediate structural support and subsequent osteointegration and stability, has not been identified yet. To overcome this, we designed a new, inexpensive Acrylic cage. A total of 64 patients were eligible to participate and were randomly allocated to undergo ACDF either with Acrylic interbody fusion cage filled with bone substitute (n=32) or PEEK cage (n=32). Nurick's grading was used for quantifying the neurological deficit. Clinical and radiologic outcome was assessed preoperatively, immediately after surgery, and subsequently at 2, 6, and 12 months of follow-up using Odom's criteria and dynamic radiographs (flexion-extension) and computed tomography scans, respectively. There was a statistically significant improvement in the clinical outcomes of the Acrylic cage group compared with the PEEK cage group (mean difference: -0.438; 95% confidence interval, -0.807 to -0.068; P=0.016). There was a statistically significant difference in disk space height increase between the 2 groups at the 6- and 12-month follow-up. The Acrylic cage achieved higher fusion rate (good fusion) than the PEEK cage (96.9% vs. 93.8%). Intervertebral angle demonstrated a significant difference among the 2 treated groups throughout the follow-up period. This study suggests that the use of Acrylic cage is associated with good clinical and radiologic outcomes and it can be therefore a

  3. Acrylic composition

    International Nuclear Information System (INIS)

    Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Meda, Yutaka.

    1969-01-01

    An acrylic composition and a process for the production of an easily hardenable coating material by irradiating with active energy, particularly electron beams and ultraviolet light, are provided using a mixture of 10%-100% by weight of an unsaturated compound and 90%-0% of a vinyl monomer. The composition has a high degree of polymerization, low volatility, low viscosity and other properties similar to thermosetting acrylic or amino alkyd resins. The aforesaid unsaturated compound is produced by primarily reacting saturated cyclocarboxylic anhydride and/or alpha-, beta-ethylene unsaturated carboxylic anhydride and by secondarily reacting an epoxy radical-containing vinyl monomer by addition reaction with polyhydric alcohols. Each reaction is conducted in the presence of a tertiary amino radical-containing vinyl monomer as a catalyst. The cross-linking is effected generally with an electron beam accelerator of 0.1-2.0 MeV or with a light beam in the 2,000-8,000A range in the presence of a photosensitive agent. In one example, 62 parts of ethylene glycol and 196 parts of maleic anhydride were dissolved in a mixture consisting of 100 parts of n-butyl methacrylate and 30 parts of styrene. To the mixture were added 5 parts of 2-methyl 5 vinyl piridine and 0.005 part of hydroquinone monomethyl ether. After the reaction at 90 0 C for 3 hours, a compound HOC:O-CH=CHC:OCH 2 CH 2 C:OOH was produced. To this solution were added 285 parts of glycidyl methacrylate. After the reaction at 90 0 C for 6 hours, 95% of the carboxylic acids reacted with epoxy radicals. Fourteen examples are given. (Iwakiri, K.)

  4. Synthesis of acrylic prepolymer

    International Nuclear Information System (INIS)

    Hussin bin Mohd Nor; Dahlan bin Haji Mohd; Mohamad Hilmi bin Mahmood.

    1988-04-01

    An acrylic prepolymer was synthesized from glycidyl methacrylate (GMA), butyl methacrylate (BMA), methyl methacrylate (MMA) and acrylic acid (AA). Butyl acetate (BAc), benzoyl peroxide (BzO), 4-methoxyphenol (MPh) and triethylamine (TEA) were used as solvent, initiator, inhibitor and catalyst respectively. Observations of the synthesis leading to the formation of acrylic prepolymer are described. (author)

  5. Acrylate Systemic Contact Dermatitis.

    Science.gov (United States)

    Sauder, Maxwell B; Pratt, Melanie D

    2015-01-01

    Acrylates, the 2012 American Contact Dermatitis Society allergen of the year, are found in a range of products including the absorbent materials within feminine hygiene pads. When fully polymerized, acrylates are nonimmunogenic; however, if not completely cured, the monomers can be potent allergens.A 28-year-old woman is presented, who had her teeth varnished with Isodan (Septodont, Saint-Maur-des-Fossés, France) containing HEMA (2-hydroxyethyl methacrylate) with no initial reaction. Approximately 1 month later, the patient developed a genital dermatitis secondary to her feminine hygiene pads. The initial reaction resolved, but 5 months later, the patient developed a systemic contact dermatitis after receiving a second varnishing.The patient was dramatically patch test positive to many acrylates. This case demonstrates a reaction to likely unpolymerized acrylates within a feminine hygiene pad, as well as broad cross-reactivity or cosensitivity to acrylates, and possibly a systemic contact dermatitis with systemic re-exposure to unpolymerized acrylates.

  6. Effects of Novel Structure Bonding Materials on Properties of Aeronautical Acrylic

    Directory of Open Access Journals (Sweden)

    LI Zhisheng

    2017-06-01

    Full Text Available Novel structure bonding materials, J-351 epoxy adhesive film with low curing temperature and liquid modified acrylate SY-50s adhesive were chosen and characterized. The effects of adhesives on the mechanical properties of acrylic were studied. The results reveal that both adhesives have excellent bonding properties to acrylic. The stress-solvent crazing value of J-351 is higher than that of SY-50s. With the application of adhesive on the surface, mechanical properties of acrylic are declined. Casting acrylic shows more drastic decline than that of oriented acrylic. Through the characterization of fracture surface, we find that fracture of tensile sample derives from the side with adhesive. Mechanical properties of acrylic are more sensitive to SY-50s, because the liquid adhesive presents integrate bonding interface with acrylic. The interface between J-351 and acrylic is clear, making acrylic insensitive to J-351 film. Edge attachment strength of samples bonded with J-351 are higher than that of samples bonded with SY-50s due to the effects of adhesives on acrylic. J-351 epoxy adhesive film presents preferable application performance in the structure bonding of aeronautical acrylic.

  7. Acrylic vessel cleaning tests

    International Nuclear Information System (INIS)

    Earle, D.; Hahn, R.L.; Boger, J.; Bonvin, E.

    1997-01-01

    The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory

  8. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  9. Management of anterior dental crossbite with removable appliances

    Directory of Open Access Journals (Sweden)

    Ayca Tuba Ulusoy

    2013-01-01

    Full Text Available This case report describes the treatment of an 8-year-old girl with anterior dental crossbite using a series of removable appliances to bring the teeth into a normal position. Clinical presentation and intervention: A removable acrylic appliance with a bite plate incorporating a screw was used to correct the anterior dental crossbite and align the incisors. The subsequent eruption of the maxillary left lateral incisor on the palatinal side was treated with a second acrylic plate incorporating a labiolingual spring. After an 8-month period, the anterior crossbite involving multiple incisors was corrected.

  10. [Acrylic resin removable partial dentures].

    Science.gov (United States)

    de Baat, C; Witter, D J; Creugers, N H J

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

  11. Comparative analysis of skin sensitization potency of acrylates (methyl acrylate, ethyl acrylate, butyl acrylate, and ethylhexyl acrylate) using the local lymph node assay.

    Science.gov (United States)

    Dearman, Rebecca J; Betts, Catherine J; Farr, Craig; McLaughlin, James; Berdasco, Nancy; Wiench, Karin; Kimber, Ian

    2007-10-01

    There are currently available no systematic experimental data on the skin sensitizing properties of acrylates that are of relevance in occupational settings. Limited information from previous guinea-pig tests or from the local lymph node assay (LLNA) is available; however, these data are incomplete and somewhat contradictory. For those reasons, we have examined in the LLNA 4 acrylates: butyl acrylate (BA), ethyl acrylate (EA), methyl acrylate (MA), and ethylhexyl acrylate (EHA). The LLNA data indicated that all 4 compounds have some potential to cause skin sensitization. In addition, the relative potencies of these acrylates were measured by derivation from LLNA dose-response analyses of EC3 values (the effective concentration of chemical required to induce a threefold increase in proliferation of draining lymph node cells compared with control values). On the basis of 1 scheme for the categorization of skin sensitization potency, BA, EA, and MA were each classified as weak sensitizers. Using the same scheme, EHA was considered a moderate sensitizer. However, it must be emphasized that the EC3 value for this chemical of 9.7% is on the borderline between moderate (10%) categories. Thus, the judicious view is that all 4 chemicals possess relatively weak skin sensitizing potential.

  12. Bonding auto-polymerising acrylic resin to acrylic denture teeth.

    LENUS (Irish Health Repository)

    Nagle, Susan

    2009-09-01

    This study investigated the effect of surface treatments on the shear bond strength of an auto-polymerising acrylic resin cured to acrylic denture teeth. The surface treatments included a combination of grit-blasting and\\/or wetting the surface with monomer. Samples were prepared and then stored in water prior to shear testing. The results indicated that the application of monomer to the surface prior to bonding did not influence the bond strength. Grit blasting was found to significantly increase the bond strength.

  13. 40 CFR 721.405 - Polyether acrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyether acrylate. 721.405 Section... § 721.405 Polyether acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polyether acrylate (PMN P-95-666) is subject to...

  14. Poly(alkyl acrylate) nonparticles

    International Nuclear Information System (INIS)

    Kreuter, J.

    1985-01-01

    This study deals with the preparation of poly(alkyl acrylic) and poly(alkyl cyanocrylic) nanoparticles. Nonoparticles are solid colloidal particles, consisting of macromolecular materials in which drugs or biologically active materials are dissolved, entrapped, and encapsulated, and/or to which the active substance is adsorbed or attached. Poly(alkyl acrylic) nanoparticles are much more slowly biodegradable than poly(alkyl cyanoacrylate) nanoparticles, and are thus more suitable for drug delivery purposes. Poly(methyl methacrylate) is the material of choice for the use of nanoparticles as an adjuvant for vaccines and are produced by emulsifier-free polymerization in aqueous media. The polymerization, which can be initiated with gamma rays or with potassium peroxodisulfate, is described

  15. Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Xiao Li-guang

    2016-01-01

    Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

  16. Radiation curing applications of palm oil acrylates

    International Nuclear Information System (INIS)

    Mohd Hilmi Mahmood; Khairul Zaman; Rida, Anak Tajau; Mek Zah Salleh; Rosley Che Ismail

    2007-01-01

    Various palm oil based urethan acrylate prepolymers (UP) were prepared from palm oil based polyols, diisocyanate compounds and hydroxyl terminated acrylate monomers by following procedure derived from established methods. The products were compared with each other in term of their molecular weights (MW), viscosities, curing speed by UV irradiation, gel contents and film hardness. The molecular structure of diisocyanate compounds and hydroxyl acrylate monomers were tend to determine the molecular weights and hence viscosities of the final products of urethan acrylate prepolymers (UP), whereas, the MW of the UP has no direct effects on the UV curing properties of the prepolymers. (author)

  17. Pigment dispersion and chronic intraocular pressure elevation after sulcus placement of 3-piece acrylic intraocular lens.

    Science.gov (United States)

    Almond, M Camille; Wu, Michael C; Chen, Philip P

    2009-12-01

    A 55-year-old man had phacoemulsification and implantation of a 3-piece acrylic intraocular lens (IOL) (AcrySof MA60AC) in the right eye. One month postoperatively, the intraocular pressure (IOP) was 48 mm Hg and peripheral transillumination defects were noted in the iris circumferentially, with the IOL optic edge visible as a silhouette. Gonioscopy showed dense pigmentation of the trabecular meshwork in the right eye, but in the left eye, only mild trabecular meshwork pigment was seen, along with a concave peripheral iris insertion. At 21 months, the right eye required 3 medications for IOP control. While pigment dispersion has been widely reported after placement of 1-piece acrylic IOLs in the ciliary sulcus, we conclude that in susceptible individuals with a concave peripheral iris insertion, pigment dispersion can occur with sulcus placement of a 3-piece acrylic model despite its thinner optic and angulated haptics.

  18. The effects of barium sufate and iodide compound on the characteristics of dental acrylic resins

    International Nuclear Information System (INIS)

    Lee, Yong Keun; Lee, Keon Il; Jung, Sung Woo

    1996-01-01

    Aspiratin or swallowing foreign bodies is a common occurrence. If they are wholly or partly radiopaque, their localization in and progress through the gastrointestinal tract can be more effective. Of the dental origin foreign materials swallowed, the most common things are fragments of anterior maxillary partial denture. But the radiopacity of denture base resins is not sufficient to determine the location of the objects. The purpose of this study was to develop a radiopaque dental acrylic resin, which has clinically detectable radiopacity with minimal change of mechanical properties and color. the radiopacity, color change (CIE E) and microhardness of acrylic resins were determined after mixing barium sulfate or iolide compound. Thermocycling course was conducted to deter mine the change of characteristic of resins after using for a long time I the mouth. Five or ten percent of barium sulfa te to total weight of cured material was mixed with heat curing dental acrylic resin or chemically curing orthodontic re sin. In the case of iodide compound, the mixing ratio was two or three percent. After mixing the high radiopaque material s, resin was cured to 20X20X2 mm plate, polished with 600 sand paper and finally polished with Microcloth (Buehler). T he specimens were thermocycled in 5 and 55 degree distilled water for 2,000 times, and the measurement of radiopacity, color and Vickers hardness was repeated every 500 times thermocycling. The radiopacity of specimens on the X-ray films was measured with densitometer (X-rite). The color change was determined with differential colorimeter (Model TC-6FX, Tokyo Denshoku), and the Vickers hardness number was measured with microhardness tester (Mitsuzawa). The following results were obtained : 1. All the three variables, the kinds of acrylic resins, the mixing or the kinds radiopaque materials and thermocycling , had combined effect on the radiopacity of the dental acrylic resins (p<0.01). 2. The two variables, the mixing or

  19. The effects of barium sufate and iodide compound on the characteristics of dental acrylic resins

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Keun; Lee, Keon Il; Jung, Sung Woo [Dept. of Oral Radiology, College of Dentistry, Wonkwang University, Iksan(Korea, Republic of)

    1996-08-15

    Aspiratin or swallowing foreign bodies is a common occurrence. If they are wholly or partly radiopaque, their localization in and progress through the gastrointestinal tract can be more effective. Of the dental origin foreign materials swallowed, the most common things are fragments of anterior maxillary partial denture. But the radiopacity of denture base resins is not sufficient to determine the location of the objects. The purpose of this study was to develop a radiopaque dental acrylic resin, which has clinically detectable radiopacity with minimal change of mechanical properties and color. the radiopacity, color change (CIE E) and microhardness of acrylic resins were determined after mixing barium sulfate or iolide compound. Thermocycling course was conducted to deter mine the change of characteristic of resins after using for a long time I the mouth. Five or ten percent of barium sulfa te to total weight of cured material was mixed with heat curing dental acrylic resin or chemically curing orthodontic re sin. In the case of iodide compound, the mixing ratio was two or three percent. After mixing the high radiopaque material s, resin was cured to 20X20X2 mm plate, polished with 600 sand paper and finally polished with Microcloth (Buehler). T he specimens were thermocycled in 5 and 55 degree distilled water for 2,000 times, and the measurement of radiopacity, color and Vickers hardness was repeated every 500 times thermocycling. The radiopacity of specimens on the X-ray films was measured with densitometer (X-rite). The color change was determined with differential colorimeter (Model TC-6FX, Tokyo Denshoku), and the Vickers hardness number was measured with microhardness tester (Mitsuzawa). The following results were obtained : 1. All the three variables, the kinds of acrylic resins, the mixing or the kinds radiopaque materials and thermocycling , had combined effect on the radiopacity of the dental acrylic resins (p<0.01). 2. The two variables, the mixing or

  20. Synthesis and characterization of acrylated Parkia biglobosa ...

    African Journals Online (AJOL)

    The results revealed that acid functional acrylic copolymers containing maleic anhydride as a functional co-monomer can successfully be used to modify alkyd resins yielding acrylated resins with better drying, flexibility, scratch hardness, impact resistance and chemical resistance properties. However there exist optimum ...

  1. 78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption

    Science.gov (United States)

    2013-09-11

    ..., 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium, potassium, ammonium..., hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium, potassium...

  2. Edge Matters

    DEFF Research Database (Denmark)

    Earon, Ofri

    2013-01-01

    of this container is to separate inside from outside and to protect and provide privacy, psychological as well as physical (Venturi, 1966). But, if dwelling phenomenon takes place both inside and outside the private house – why is the urban house an enclosed box? What is the differentiation between inside...... and outside the contemporary urban house? And what is the interplay between them? The research argues for re-thinking the edge zone between inside and outside the urban house. Therefore, although, residential buildings in the city are the objects of study, the focal point here is the edge zone along...... the building. The research explores and develops the architectural characteristics of correlations between the resident, the singular unit, the building and the given location at the edge zone. It approaches the edge zone of the urban house as a platform for dynamic interactions between these behaviours...

  3. Microstructural characterization of a novel methyl acrylate-ethyl acrylate copolymer system

    Energy Technology Data Exchange (ETDEWEB)

    Olivares, M.; Castano, V.M. [Instituto de Fisica, UNAM, A.P. 1-1010, Queretaro, Mexico (Mexico); Molina, J.P.; Vazquez, F. [Facultad de Quimica UAEMex, Paseo Tollocan esq. Paseo Colon, Toluca, Estado de Mexico (Mexico)

    1998-12-31

    A number of different compositions of a novel methyl acrylate-ethyl acrylate copolymer were prepared by emulsion polymerization with potassium persulfate as initiator. The compositions synthesized were: 100/0, 75/25, 50/50, 25/75 and 0/100 on weight of methyl acrylate/ethyl acrylate at different temperatures and concentrations of initiators. The effect of other conditions were also studied. The samples were analyzed by Transmission Electron Microscopy. It was found that the size of aggregates and dispersion on sizes are controlled by the synthesis conditions, result partially supported by light scattering. (Author)

  4. Microstructural characterization of a novel methyl acrylate-ethyl acrylate copolymer system

    International Nuclear Information System (INIS)

    Olivares, M.; Castano, V.M.; Molina, J.P.; Vazquez, F.

    1998-01-01

    A number of different compositions of a novel methyl acrylate-ethyl acrylate copolymer were prepared by emulsion polymerization with potassium persulfate as initiator. The compositions synthesized were: 100/0, 75/25, 50/50, 25/75 and 0/100 on weight of methyl acrylate/ethyl acrylate at different temperatures and concentrations of initiators. The effect of other conditions were also studied. The samples were analyzed by Transmission Electron Microscopy. It was found that the size of aggregates and dispersion on sizes are controlled by the synthesis conditions, result partially supported by light scattering. (Author)

  5. Synthesis of epoxidised soya bean oil acrylate

    International Nuclear Information System (INIS)

    Hussin bin Mohd Nor; Mohamad Hilmi bin Mahmood; Dahlan bin Haji Mohd.

    1988-10-01

    An epoxy acrylate was synthesized from Asahi's epoxy resin AER 331 which is an epoxidised soya bean oil (ESBO). Triethylamine (TEA) and Hydroquinone (HQ) were used as catalyst and inhibitor respectively. Observations of the experiment are described. (author)

  6. Crystal structure transformation in potassium acrylate

    Science.gov (United States)

    Pai Verneker, V. R.; Vasanthakumari, R.

    1983-10-01

    Potassium acrylate undergoes a reversible phase transformation around 335°K with an activation energy of 133 kcal/mole. Differential scanning calorimetry and high temperature X-ray powder diffraction techniques have been used to probe this phenomenon.

  7. The removable acrylic partial denture in primary care: the experience and satisfaction of dental surgeons

    Directory of Open Access Journals (Sweden)

    Rita de Cássia SILVA

    2017-11-01

    Full Text Available Abstract Introduction The guidelines of the National Politics of Oral Health have led to the inclusion of elemental prostheses in the list of Primary Care procedures. Objective This paper aimed to evaluate the performance and satisfaction of dental surgeons with the implementation of Acrylic Partial Dentures. Metodology The sample was composed by 159 dental surgeons (sample calculation, in Belo Horizonte, MG, Brazil, selected via raffle (simple random sampling. A structured questionnaire was built with 72 questions on the daily practice of the performance of dental surgeons, using the SurveyMonkey platform. Result The results showed that for most of dental surgeons, the inclusion on the list of primary care procedures was a positive initiative and they have enjoyed the experience of using Acrylic Partial Dentures. Dental surgeons who had graduated in private institutions reported to have had more failures than those who had graduated in public institutions. The better prepared dental surgeons reported less difficulties and failures, and the more satisfied professionals with the performance of Acrylic Partial Dentures related had also experienced fewer failures. Considering the indication, the majority of participants did it according to the protocol of the institution (only for anterior teeth but many revealed the use of dentures also for premolars. Conclusion Acrylic partial dentures have been a reality in the Brazilian social context even before their inclusion in the list of Primary Care procedures. Such inclusion indicates their relevance; however, it is necessary to have their confection systematized by a protocol in public services.

  8. Anterior open bite treatment with magnets.

    Science.gov (United States)

    Kiliaridis, S; Egermark, I; Thilander, B

    1990-11-01

    The aim of this study was to examine the effects of repelling magnets on the treatment of anterior open bite and compare them with the effects of acrylic posterior bite-blocks. Twenty patients, aged 9-16 years with skeletal anterior open bite, were randomly divided into two groups. In one group the patients wore posterior repelling magnet splints and in the other they wore acrylic posterior bite-blocks of the same thickness as the magnet splints. The patients were instructed to use their appliance as much as possible (the minimum accepted being 18 hours daily) during a 6-month period. Dental casts, intra-oral photos, and lateral cephalograms were taken before and after treatment, and the patients were also examined regularly to identify the development of any craniomandibular disorders. In the first group, the dental and skeletal vertical relation responded quickly to the magnet treatment. The open bite was generally closed in just under 4 months, especially in patients in early mixed dentition. Spacing in the labial segments decreased in some cases, while slight crowding was induced in others. Transverse problems, i.e. unilateral cross-bite, sometimes followed by scissor-bite on the opposite side, was observed in those patients who were in the early mixed dentition and had used the magnets intensively. The patients who wore acrylic posterior bite-blocks also showed improvement in the dental and skeletal vertical relationships, especially during the first months. This was followed by a 'plateau' period. No transverse problems were found in these patients.

  9. Allergic contact dermatitis to acrylates in disposable blue diathermy pads.

    Science.gov (United States)

    Sidhu, S. K.; Shaw, S.

    1999-01-01

    We report 2 cases of elicitation of allergic contact dermatitis to acrylates from disposable blue diathermy pads used on patients who underwent routine surgery. Their reactions were severe, and took approximately 5 weeks to resolve. Both patients gave a prior history of finger tip dermatitis following the use of artificial sculptured acrylic nails, which is a common, but poorly reported, cause of acrylate allergy. Patch testing subsequently confirmed allergies to multiple acrylates present in both the conducting gel of disposable blue diathermy pads, and artificial sculptured acrylic nails. We advocate careful history taking prior to surgery to avoid unnecessary exposure to acrylates in patients already sensitized. Images Figure 1 Figure 2 PMID:10364952

  10. Methacrylate and acrylate allergy in dental personnel.

    Science.gov (United States)

    Aalto-Korte, Kristiina; Alanko, Kristiina; Kuuliala, Outi; Jolanki, Riitta

    2007-11-01

    Methacrylates are important allergens in dentistry. The study aimed to analyse patch test reactivity to 36 acrylic monomers in dental personnel in relation to exposure. We reviewed the test files at the Finnish Institute of Occupational Health from 1994 to 2006 for allergic reactions to acrylic monomers in dental personnel and analysed the clinical records of the sensitized patients. 32 patients had allergic reactions to acrylic monomers: 15 dental nurses, 9 dentists, and 8 dental technicians. The dentists and dental nurses were most commonly exposed to 2-hydroxyethyl methacrylate (2-HEMA), triethyleneglycol dimethacrylate (TREGDMA), and 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA). 8 dentists and 12 dental nurses were allergic to 2-HEMA. The remaining dentist was positive to bis-GMA and other epoxy acrylates. The remaining 3 dental nurses reacted to diethyleneglycol diacrylate (DEGDA) or triethyleneglycol diacrylate (TREGDA), but not to monofunctional and multifunctional methacrylates. Our dental technicians were mainly exposed and sensitized to methyl methacrylate (MMA) and ethyleneglycol dimethacrylate (EGDMA). 1 technician reacted only to 2-HEMA, and another to ethyl methacrylate (EMA) and ethyl acrylate (EA). 2-HEMA was the most important allergen in dentists and dental nurses, and MMA and EGDMA in dental technicians. Reactions to bis-GMA, DEGDA, TREGDA, EMA and EA were relevant in some patients.

  11. Edge Detection,

    Science.gov (United States)

    1985-09-01

    PROJECT. T ASK0 Artificial Inteligence Laboratory AREA It WORK UNIT NUMBERS V 545 Technology Square ( Cambridge, HA 02139 I I* CONTOOL1LIN@4OFFICE NAME...ARD-A1t62 62 EDGE DETECTION(U) NASSACNUSETTS INST OF TECH CAMBRIDGE 1/1 ARTIFICIAL INTELLIGENCE LAB E C HILDRETH SEP 85 AI-M-8 N99SI4-8S-C-6595...used to carry out this analysis. cce~iO a N) ’.~" D LI’BL. P p ------------ Sj. t i MASSACHUSETTS INSTITUTE OF TECHNOLOGY i ARTIFICIAL INTELLIGENCE

  12. Photochemistry of acrylates at 222 nm

    International Nuclear Information System (INIS)

    Knolle, Wolfgang; Naumov, Sergej; Madani, Mohamed; Sonntag, Clemens von

    2005-01-01

    Excimer lamps as monochromatic UV sources with an intense short-wavelength emission (especially KrCl * , 222 nm) allow a photoinitiator-free initiation of the acrylate polymerisation. Laser photolysis (KrCl * excimer laser, pulse width 20 ns, up to 5 mJ per pulse) gives rise to similar transient spectra (λ max ∼ 280 nm) for all acrylates studied. As the rather unspecific spectra do not allow conclusions as to the main reaction channel, a product study has been performed by GC-MS following steady-state photolysis of acrylate solutions in acetonitrile, methanol and n-hexane. Somewhat unexpected, α-cleavage seems to be a main reaction channel, and quantum chemical calculations show that such a reaction can occur from either the excited singlet state or the unrelaxed triplet state, but not from the relaxed triplet state that is observed spectroscopically. A reaction scheme accounting for the observed products is presented

  13. The management of over closured anterior teeth due to attrition

    Directory of Open Access Journals (Sweden)

    Eha Djulaeha

    2009-12-01

    Full Text Available Background: Tooth is the hardest tissue in human body, that can be injured because of attrition process. For old people, denture attrition process is caused by psysiological process relating with the mastication function which also supported by some bad habits such an bruxism, premature contact, and consuming habit of abrasive food. Attrition or abrasion can also be happened with patien’t dentition who does not have teeth subtutition for long time due the lost of their maxillary as well as mandibulary. The pasient will loose their vertical dimension of occlusion, injure, and the lower jaw becomes over closed which is called over closure. Purpose: This article reported the management of over closured anterior teeth due to attrition. Case: a seventy six year old woman patient came to Prosthodontic Clinic in Faculty of Dentistry, Airlangga University, to rehabilitate her upper and lower severe attrited anterior teeth and her posterior teeth. The patient has experienced of wearing acrylic removable mandibular partial denture ten years ago. Unfortunaly, the denture was uncomfortable, and she did not wear it anymore since five years ago. Case management: The severe attrition of anterior teeth with the lost of occlusal vertical dimension can be treated by improving the occlusal vertical dimension gradually. The treatment is then followed by the increasing of the height of the anterior teeth by lengthening the crown teeth of upper jaw with 12 units of span bridge and the acrylic removable partial denture of lower jaw. Conclusion: The severe attrition of anterior teeth with the lost of occlusal vertical dimension can be treated by improving the occlusal vertical dimension gradually, using long span bridge and acrylic removable partial denture.

  14. Concepts for stereoselective acrylate insertion

    KAUST Repository

    Neuwald, Boris

    2013-01-23

    Various phosphinesulfonato ligands and the corresponding palladium complexes [{((PaO)PdMeCl)-μ-M}n] ([{( X1-Cl)-μ-M}n], (PaO) = κ2- P,O-Ar2PC6H4SO2O) with symmetric (Ar = 2-MeOC6H4, 2-CF3C6H4, 2,6-(MeO)2C6H3, 2,6-(iPrO)2C 6H3, 2-(2′,6′-(MeO)2C 6H3)C6H4) and asymmetric substituted phosphorus atoms (Ar1 = 2,6-(MeO)2C6H 3, Ar2 = 2′-(2,6-(MeO)2C 6H3)C6H4; Ar1 = 2,6-(MeO)2C6H3, Ar2 = 2-cHexOC 6H4) were synthesized. Analyses of molecular motions and dynamics by variable temperature NMR studies and line shape analysis were performed for the free ligands and the complexes. The highest barriers of ΔGa = 44-64 kJ/mol were assigned to an aryl rotation process, and the flexibility of the ligand framework was found to be a key obstacle to a more effective stereocontrol. An increase of steric bulk at the aryl substituents raises the motional barriers but diminishes insertion rates and regioselectivity. The stereoselectivity of the first and the second methyl acrylate (MA) insertion into the Pd-Me bond of in situ generated complexes X1 was investigated by NMR and DFT methods. The substitution pattern of the ligand clearly affects the first MA insertion, resulting in a stereoselectivity of up to 6:1 for complexes with an asymmetric substituted phosphorus. In the consecutive insertion, the stereoselectivity is diminished in all cases. DFT analysis of the corresponding insertion transition states revealed that a selectivity for the first insertion with asymmetric (P aO) complexes is diminished in the consecutive insertions due to uncooperatively working enantiomorphic and chain end stereocontrol. From these observations, further concepts are developed. © 2012 American Chemical Society.

  15. All-acrylic superelastomers: facile synthesis and exceptional mechanical behavior

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei; Goodwin, Andrew; Wang, Yangyang; Yin, Panchao; Wang, Weiyu; Zhu, Jiahua; Wu, Ting; Lu, Xinyi; Hu, Bin; Hong, Kunlun; Kang, Nam-Goo; Mays, Jimmy (Tennessee-K); (ORNL)

    2018-01-01

    All-acrylic multigraft copolymers made by a facile synthesis procedure exhibit elongation at break >1700% and strain recovery behavior far exceeding those of commercial acrylic and styrenic triblock copolymers.

  16. Anterior perineal hernia after anterior exenteration

    Directory of Open Access Journals (Sweden)

    Ka Wing Wong

    2017-10-01

    Full Text Available Perineal hernia is a rare complication of anterior exenteration. We reported this complication after an anterior exenteration for bladder cancer with bleeding complication requiring packing and second-look laparotomy. Perineal approach is a simple and effective method for repair of perineal hernia.

  17. Living edge

    DEFF Research Database (Denmark)

    Earon, Ofri

    2014-01-01

    was originally introduced to enhance indoor qualities including light and view. Throughout the paper, it is argued that these ecological motives have grown to architectural and urban dimensions. The paper analyzes the characteristics and potentials of these dimensions and their interconnections. The paper...... on the ground level, but there is a lack of recognition in the significance of communicative characters as well at the higher part of the edge. The city’s planning approach is “Consider urban life before urban space. Consider urban space before buildings” This urban strategy neglects the possible architectural...... contribution to the street atmosphere and its effect on urban life. Bay balcony has been a common architectural element in Copenhagen’s residential buildings, since the end of the twenties. It is a domestic border with an architectural thickness combining window, door, windowsill and balcony. The bay balcony...

  18. 40 CFR 721.8082 - Polyester polyurethane acrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyester polyurethane acrylate. 721... Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as polyester polyurethane acrylate...

  19. Amylase catalyzed synthesis of glycosyl acrylates and their polymerization

    NARCIS (Netherlands)

    Kloosterman, Wouter M.J.; Jovanovic, Danijela; Brouwer, Sander; Loos, Katja

    2014-01-01

    The enzymatic synthesis of novel (di)saccharide acrylates from starch and 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and 4-hydroxybutyl acrylate (2-HEA, 2-HEMA and 4-HBA) catalyzed by various commercially available amylase preparations is demonstrated. Both liquefaction and

  20. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be safely...

  1. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-ethyl acrylate copolymers. 177.1320... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1320 Ethylene-ethyl acrylate copolymers. Ethylene-ethyl acrylate copolymers may be safely used to produce packaging materials, containers...

  2. Investigation of Acrylic Acid at High Pressure using Neutron Diffraction

    DEFF Research Database (Denmark)

    Johnston, Blair F.; Marshall, William G.; Parsons, Simon

    2014-01-01

    This article details the exploration of perdeuterated acrylic acid at high pressure using neutron diffraction. The structural changes that occur in acrylic acid-d4 are followed via diffraction and rationalised using the Pixel method. Acrylic acid undergoes a reconstructive phase transition to a new...

  3. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate polymer...

  4. Radiation-induced graft copolymerization of methyl acrylate and acrylic acid onto rubber wood fiber

    International Nuclear Information System (INIS)

    Saliza Jam; Mansor Ahmad; Wan Md Zin Wan Yunus; Khairul Zaman Mohd Dahlan

    2001-01-01

    Graft copolymerization of methyl acrylate and acrylic acid monomers onto rubber wood fiber (RWF) was carried out by simultaneous radiation-induced technique. The parameters affecting the grafting reaction were investigated and the optimum conditions for both monomers obtained are as follows: impregnation time = 16 hours, total dose = 30 kGy, methanol : water ratio, 3:1, monomers concentration = 40 v/v % and sulphuric acid concentration = 0.1 mol/L. Fourier Transform Infrared (FTIR), thermogravimetry analysis (TGA), and scanning electron microscope (SEM) analyses used to characterize graft copolymers. The structural investigation by x-ray diffraction (XRD) shows the degree of crystallinity of rubber wood fiber decreased with the incorporation of poly(methyl acrylate) and poly(acrylic acid) grafts. (Author)

  5. Poly(lauryl acrylate) and poly(stearyl acrylate) grafted multiwalled carbon nanotubes for polypropylene composites

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Jankova Atanasova, Katja; Hvilsted, Søren

    2014-01-01

    Two new polymer grafts on an industrial grade multiwalled carbon nanotube (MWCNT) were prepared through a non-oxidative pathway employing controlled free radical polymerization for surface initiated polymer grafting. After photochemical introduction of an ATRP initiator onto the MWCNT......, polymerizations of lauryl or stearyl acrylate were performed, resulting in two novel polymer modifications on the MWCNT (poly(lauryl acrylate) or poly(stearyl acrylate)). The method was found to give time dependent loading of polymers as a function of time (up to 38 wt% for both acrylates), and showed a plateau...... in loading after 12 h of polymerization. The modified nanomaterials were melt mixed into polypropylene composites with very low filler loading (0.3 wt%), whereafter both the thermal and electrical properties were investigated by DSC and dielectric resonance spectroscopy. The electrical properties were found...

  6. Pressure-induced polymerization of phenoxyethyl acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, K; Wrzalik, R; Paluch, M; Ziolo, J [Institute of Physics, Silesian University, Uniwersytecka 4, 40-007 Katowice (Poland); Roland, C M [Naval Research Laboratory, Chemistry Division, Code 6120, Washington, DC 20375-5342 (United States)

    2008-06-18

    Polymerization of phenoxyethyl acrylate was induced without catalyst or initiators by the application of hydrostatic pressure at elevated temperature. Broadband dielectric and infrared spectroscopy were employed to follow the course of the reaction, which reached a degree of conversion of 60%. The structure of the obtained polymer was determined from density functional theory calculations.

  7. SYNTHESIS AND CHARACTERIZATION OF ACRYLATED PARKIA ...

    African Journals Online (AJOL)

    a

    successfully be used to modify alkyd resins yielding acrylated resins with ... superstructure of ships, the paint is also in addition to the above exposed to wind driven salt ... possibility of combining the desirable application and film forming properties of .... Then the temperature was further increased to 230 oC and the reaction.

  8. UV-Curing of Nanoparticle Reinforced Acrylates

    International Nuclear Information System (INIS)

    Bauer, F.

    2006-01-01

    Polymer reinforcement by silica and alumina nanoparticles evidently yields improved surface hardness. Single mixing of nanoparticles into an acrylate formulations, however, leads to highly viscous solutions inappropriate for coating procedures. The incompatibility of inorganic fillers and organic polymers can be avoided by surface modification providing an interface between the two dissimilar materials. For example, vinyltrimethoxysilane (VTMO) can react via hydrolysis/condensation reactions with hydroxyl groups present on the inorganic surface and should bond via the polymerisation-active vinyl group to an acrylate resin through crosslinking reactions. Grafting reactions of surface OH groups and different trialkoxysilanes were studied by thermogravimetry, infrared, and multinuclear NMR spectroscopy. The copolymeri-zation of modified nanoparticles with the acrylate matrix has been investigated by 13 C NMR spectroscopy. UV curing under nitrogen inertization revealed a lower reactivity of vinyl groups of VTMO-modified silica compared to grafted methacryloxypropyl-trimethoxysilane (MEMO) which showed complete conversion of olefinic carbons (signals at 120 - 140 ppm). Under conditions of oxygen inhibition, the effect of the kind and the concentration of photoinitiator on the photopoly-merization reaction was studied. Compared to neat polyacrylate coatings the nanocomposite materials exhibit markedly improved properties, e.g., heat, scratch, and abrasion resistance. However, a much better abrasion resistance was obtained for coatings containing both silica nano-particles and corundum microparticles. In particular cases, radiation curing with 172 nm photons generated by Xe excimer was performed to obtain structured polymer surfaces, i.e., matting of the reinforced acrylate coatings

  9. Contact allergy to epoxy (meth)acrylates.

    Science.gov (United States)

    Aalto-Korte, Kristiina; Jungewelter, Soile; Henriks-Eckerman, Maj-Len; Kuuliala, Outi; Jolanki, Riitta

    2009-07-01

    Contact allergy to epoxy (meth)acrylates, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA), 2,2-bis[4-(2-hydroxy-3-acryloxypropoxy)phenyl]-propane (bis-GA), 2,2-bis[4-(methacryl-oxyethoxy)phenyl] propane (bis-EMA), 2,2-bis[4-(methacryloxy)phenyl]-propane (bis-MA), and glycidyl methacrylate (GMA) is often manifested together with contact allergy to diglycidyl ether of bisphenol A (DGEBA) epoxy resin. To analyse patterns of concomitant allergic reactions to the five epoxy (meth)acrylates in relation to exposure. We reviewed the 1994-2008 patch test files at the Finnish Institute of Occupational Health (FIOH) for reactions to the five epoxy (meth)acrylates, and examined the patients' medical records for exposure. Twenty-four patients had an allergic reaction to at least one of the studied epoxy (meth)acrylates, but specific exposure was found only in five patients: two bis-GMA allergies from dental products, two bis-GA allergies from UV-curable printing inks, and one bis-GA allergy from an anaerobic glue. Only 25% of the patients were negative to DGEBA epoxy resin. The great majority of allergic patch test reactions to bis-GMA, bis-GA, GMA and bis-EMA were not associated with specific exposure, and cross-allergy to DGEBA epoxy resin remained a probable explanation. However, independent reactions to bis-GA indicated specific exposure. Anaerobic sealants may induce sensitization not only to aliphatic (meth)acrylates but also to aromatic bis-GA.

  10. Large Acrylic Spherical Windows In Hyperbaric Underwater Photography

    Science.gov (United States)

    Lones, Joe J.; Stachiw, Jerry D.

    1983-10-01

    Both acrylic plastic and glass are common materials for hyperbaric optical windows. Although glass continues to be used occasionally for small windows, virtually all large viewports are made of acrylic. It is easy to uderstand the wide use of acrylic when comparing design properties of this plastic with those of glass, and glass windows are relatively more difficult to fabricate and use. in addition there are published guides for the design and fabrication of acrylic windows to be used in the hyperbaric environment of hydrospace. Although these procedures for fabricating the acrylic windows are somewhat involved, the results are extremely reliable. Acrylic viewports are now fabricated to very large sizes for manned observation or optical quality instrumen tation as illustrated by the numerous acrylic submersible vehicle hulls for hu, an occupancy currently in operation and a 3600 large optical window recently developed for the Walt Disney Circle Vision under-water camera housing.

  11. Electrochemical investigation on an acrylated thiophene

    Energy Technology Data Exchange (ETDEWEB)

    Hogervorst, A.C.R. (TNO Plastics and Rubber Research Inst., Delft (Netherlands)); Kock, T.J.J.M. (TNO Plastics and Rubber Research Inst., Delft (Netherlands)); Ruiter, B. de (TNO Plastics and Rubber Research Inst., Delft (Netherlands)); Waal, A. van der (TNO Plastics and Rubber Research Inst., Delft (Netherlands))

    1993-03-22

    The electrochemical behaviour of electropolymerized 2-(3-thienyl)ethyl acrylate (PAcrT) has been investigated, and compared to the behaviour of electropolymerized thiophene and 3-n-decylthiophene (PDT). The effect of electron beam irradiation on the electrochemical properties of these three polymers has been studied. It has been found that for PAcrT the oxidation wave shifts to higher potentials upon electron beam irradiation. For PDT a similar but smaller change occurs. We suggest that the shift of the oxidation wave of PAcrT is caused by cross-links, formed between the acrylate substituents, which fixate the main chain parts in twisted states and reduce the conjugation length. (orig.)

  12. Dermal oncogenicity bioassays of monofunctional and multifunctional acrylates and acrylate-based oligomers.

    Science.gov (United States)

    DePass, L R; Maronpot, R R; Weil, C S

    1985-01-01

    Several important components of photocurable coatings were studied for dermal tumorigenic activity by repeated application to the skin of mice. The substances tested were 2-ethylhexyl acrylate (EHA) and methylcarbamoyloxyethyl acrylate (MCEA) (monomers); neopentyl glycol diacrylate (NPGDA), esterdiol-204-diacrylate (EDDA), and pentaerythritol tri(tetra)acrylate (PETA) (cross-linkers); and three acrylated urethane oligomers. For each bioassay, 40 C3H/HeJ male mice were dosed 3 times weekly on the dorsal skin for their lifetime with the highest dose of the test agent that caused no local irritation or reduction in body weight gain. Two negative control groups received acetone (diluent) only. A positive control group received 0.2% methylcholanthrene (MC). NPGDA and EHA had significant tumorigenic activity with tumor yields of eight and six tumor-bearing mice (three and two malignancies), respectively. The MC group had 34 mice with carcinomas and 1 additional mouse with a papilloma. MCEA had no dermal tumorigenic activity but resulted in early mortality. No skin tumors in the treatment area were observed in the other groups. Additional studies will be necessary to elucidate possible relationships between structure and tumorigenic activity for the acrylates.

  13. 'Weightless' acrylic painting by Jack Kroehnke

    Science.gov (United States)

    1987-01-01

    'Weightless' acrylic painting by Jack Kroehnke depicts STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) David C. Hilmers participating in extravehicular activity (EVA) simulation in JSC Weightless Environment Training Facility (WETF) Bldg 29. In the payload bay (PLB) mockup, Hilmers, wearing extravehicular mobility unit (EMU), holds onto the mission-peculiar equipment support structure in foreground while SCUBA-equipped diver monitors activity overhead and camera operator records EVA procedures. Copyrighted art work for use by NASA.

  14. MR imaging of the anatomy of the anterior horn of the medial meniscus.

    Science.gov (United States)

    De Coninck, Tineke; Vanrietvelde, Frederik; Seynaeve, Patrick; Verdonk, Peter; Verstraete, Koenraad

    2017-04-01

    Background In cadaveric and arthroscopic studies different insertion locations of the anterior horn of the medial meniscus (AHMM) have been described. Purpose To investigate if the different insertion locations of the AHMM, as described in cadaveric studies, can be determined on magnetic resonance imaging (MRI). Material and Methods MR images of 100 patients without meniscal tears on MRI were retrospectively evaluated. Two observers classified the AHMM insertion based on its position relative to the anterior tibial edge and the medial tibial spine. The association between AHMM insertion and tibial plateau slope, meniscal radial displacement, and anterior intermeniscal ligament (AIL) presence was investigated. Results The AHMM inserted posterior to the anterior tibial edge in 93 knees and anterior to the tibial edge in seven knees (= type III). Of the 93 knees with AHMM insertion posterior to the anterior tibial edge, 63 inserted lateral to the medial tibial spine (= type I) and 30 medial (= type II). The AHMMs inserting anterior to the tibial edge had a significantly ( P  0.05). A strong inter- and intra-observer agreement was observed. Conclusion Three different bony insertion locations of the AHMM, as described in cadaveric studies, could be identified on MRI. All AHMMs inserting anterior to the tibial edge displayed an AIL. Whether there is a clinical correlation with these insertion patterns remains unclear.

  15. Effect of cutter tip angle on cutting characteristics of acrylic worksheet subjected to punch/die shearing

    Directory of Open Access Journals (Sweden)

    Masami Kojima

    2016-12-01

    Full Text Available This paper aims to describe the effect of tool geometry on cutting characteristics of a 1.0 mm thickness acrylic worksheet subjected to a punch/die shearing. A set of side-wedge punch and side-wedge die which had the edge angle of 30°, 60° and/or 90° was prepared and used for cutting off the worksheet. A load cell and a CCD camera were installed in the cutting system to investigate the cutting load resistance and the side-view deformation of the worksheet. From experimental results, it was revealed that a cracking pattern at a sheared zone was remarkably affected by the edge angle of cutting tool. A cracking direction was almost coincident to the edge angle when considering the punch/die edge angle of 30°, while any matching of them was not observed in case of the punch/die edge angle of 60°, 90°. By using the 30° side-wedge tool, a flat-smooth sheared surface was generated. When combing the punch edge angle of 90° and the die edge angle of 60°, the cracking profile was characterized by the both edge angles for each part (die and punch. Carrying out an elasto-plastic finite element method analysis of cutter indentation with a few of symmetric and asymmetric punch/die edges, the stress distribution and deformation flow at the sheared zone were discussed with the initiation of surface cracks

  16. Waterborne hyperbranched alkyd-acrylic resin obtained by miniemulsion polymerization

    Directory of Open Access Journals (Sweden)

    Edwin Murillo

    Full Text Available Abstract Four waterborne hyperbranched alkyd-acrylic resins (HBRAA were synthesized by miniemulsion polymerization from a hyperbranched alkyd resin (HBR, methyl methacrylate (MMA, butyl acrylate (BA and acrylic acid (AA, by using benzoyl peroxide (BPO and ammonium persulfate (AP as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC, nuclear magnetic resonance (NMR and gel permeation chromatography (GPC. The conversion percentage, glass transition temperature (Tg, content of acrylic polymer (determined by soxhlet extraction and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly monomodal. The film properties (gloss, flexibility, adhesion and drying time of the HBRAA were good.

  17. Synthesis and characterization of acrylated Parkia biglobosa medium oil alkyds

    Directory of Open Access Journals (Sweden)

    E.T. Akintayo

    2004-12-01

    Full Text Available Acrylated Parkia biglobosa medium oil alkyd prepared by the reaction between an acid containing acrylic copolymer and a monoglyceride followed by the addition of polyol and dibasic acid has been investigated for improved properties. The results revealed that acid functional acrylic copolymers containing maleic anhydride as a functional co-monomer can successfully be used to modify alkyd resins yielding acrylated resins with better drying, flexibility, scratch hardness, impact resistance and chemical resistance properties. However there exist optimum levels for modification of alkyds with such copolymers beyond which certain film properties are adversely affected.

  18. Palm oil based polyols for acrylated polyurethane production

    International Nuclear Information System (INIS)

    Rida Tajau; Mohd Hilmi Mahmood; Mek Zah Salleh; Khairul Zaman Mohd Dahlan; Rosley Che Ismail

    2006-01-01

    Palm oil becomes important renewable resources for the production of polyols for the polyurethane manufacturing industry. The main raw materials used for the production of acrylated polyurethane are polyols, isocyanates and hydroxyl terminated acrylate compounds. In these studies, polyurethane based natural polymer (palm oil), i.e., POBUA (Palm Oil Based Urethane Acrylate) were prepared from three different types of palm oil based polyols i.e., epoxidised palm oil (EPOP), palm oil oleic acid and refined, bleached and deodorized (RBD) palm olein based polyols. The performances of these three acrylated polyurethanes when used for coatings and adhesives were determined and compared with each other. (Author)

  19. Synthesis of Poly(styrene-acrylates-acrylic acid Microspheres and Their Chemical Composition towards Colloidal Crystal Films

    Directory of Open Access Journals (Sweden)

    Luis A. Ríos-Osuna

    2016-01-01

    Full Text Available In this paper, polystyrene colloidal microspheres have been prepared using hexyl acrylate (HA, ethylhexyl acrylate (EHA, isooctyl acrylate (IOA, butyl acrylate (BA, or isobutyl acrylate (IBA as comonomers. Microspheres with diameters from 212 to 332 nm and with a polystyrene content of 65–78% were prepared. The particles prepared in this work do not present the typical core-shell structure; as a consequence, DSC analysis showed that the microspheres exhibited only one Tg. TEM images show that the particles with comonomer content below ~30% were spherical and regular. Microspheres containing comonomer between 21 to 25% produced the less brittle films showing very iridescent colors. The films prepared from microspheres containing hexyl, ethylhexyl, and isooctyl acrylate as comonomers are firmly attached to the substrate due to their adhesive properties. The large decrease of the fragility observed in these films makes them much more attractive materials in sensing applications.

  20. Electron beam curing of acrylic oligomers

    International Nuclear Information System (INIS)

    Seto, J.; Arakawa, S.; Ishimoto, C.; Miyashita, M.; Nagai, T.; Noguchi, T.; Shibata, A.

    1984-01-01

    The electron-beam curing process of acrylic oligomers, with and without γ-Fe 2 O 3 pigment filler and blended linear polymer, was investigated in terms of molecular structure and reaction mechanism. The polymerized fraction of trimethylolpropane-triacrylate (TMPTA) oligomers increases with increasing total dose, and is independent of the dose rate. Since the reaction rate is linearly dependent on the dose rate, the reaction mechanism involves monomolecular termination. The reaction rate does not depend on the number of functional groups of the oligomer at low doses, but above 0.3 Mrad the rate is slower for oligomers of higher functionality. A gel is formed more readily upon curing of a polyfunctional than a monofunctional oligomer, especially at high conversion to polymer; the resulting loss of flexibility of the polymer chains slows the reaction. Decrease of the molecular weight per functional group results in lower conversion; this is also due to the loss of chain flexibility, which is indicated as well by a higher glass-transition temperature. Modification of the acrylate oligomers with urethane results in more effective cross-linking reactions because of the more rigid molecular chains. Addition of γ-Fe 2 O 3 pigment reduces the reaction rate very little, but has the effect of providing added structural integrity, as indicated by the decrease of solvent-extractable material and the improvement of anti-abrasion properties. However, the flexibility of the coating and its adhesion to a PET base film are diminished. To increase the flexibility, linear polyvinylchloride and/or polyurethane were added to the acrylic oligomers. Final conversion to polymer was nearly 100 percent, and a higher elastic modulus and better antiabrasion properties were realized

  1. Artificial saliva effect on toxic substances release from acrylic resins

    Directory of Open Access Journals (Sweden)

    Kostić Milena

    2015-01-01

    Full Text Available Background/Aim. Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS immediately upon polymerization and incubation in different types of artificial saliva. Methods. Storage of acrylic samples in two models of artificial saliva were performed in a water bath at the temperature of 37 ± 1°C. Analysis of the surface structure of samples was carried out using scanning electronic microscopy analysis immediately after polymerization and after the 30-day incubation. The amounts of PTS per day, week and month extracts were measured using high-pressure liquid chromatography. Results. Surface design and amount of PTS in acrylic materials were different and depended on the types and duration of polymerization. The surfaces of tested acrylates became flatter after immersing in solutions of artificial saliva. The degree of acrylic materials release was not dependent on the applied model of artificial saliva. Conclusion. In order to improve biological features of acrylic resin materials, it was recommended that dentures lined with soft or hard coldpolymerized acrylates should be kept at least 1 to 7 days in water before being given to a patient. So, as to reach high degree of biocompatibility preparation of prosthetic restorations from heat-polymerized acrylate was unnecessary. [Projekat Ministarstva nauke Republike Srbije, br. 41017

  2. Congenital anterior urethral diverticulum

    International Nuclear Information System (INIS)

    Jung, Hyun Sub; Chung, Young Sun; Suh, Chee Jang; Won, Jong Jin

    1985-01-01

    Two cases of congenital anterior urethral diverticular which have occurred in a 4 year old and one month old boy are presented. Etiology, diagnostic procedures, and its clinical results are briefly reviewed

  3. Interactions between Therapeutic Proteins and Acrylic Acid Leachable.

    Science.gov (United States)

    Liu, Dengfeng; Nashed-Samuel, Yasser; Bondarenko, Pavel V; Brems, David N; Ren, Da

    2012-01-01

    Leachables are chemical compounds that migrate from manufacturing equipment, primary containers and closure systems, and packaging components into biopharmaceutical and pharmaceutical products. Acrylic acid (at concentration around 5 μg/mL) was detected as leachable in syringes from one of the potential vendors (X syringes). In order to evaluate the potential impact of acrylic acid on therapeutic proteins, an IgG 2 molecule was filled into a sterilized X syringe and then incubated at 45 °C for 45 days in a pH 5 acetate buffer. We discovered that acrylic acid can interact with proteins at three different sites: (1) the lysine side chain, (2) the N-terminus, and (3) the histidine side chain, by the Michael reaction. In this report, the direct interactions between acrylic acid leachable and a biopharmaceutical product were demonstrated and the reaction mechanism was proposed. Even thought a small amount (from 0.02% to 0.3%) of protein was found to be modified by acrylic acid, the modified protein can potentially be harmful due to the toxicity of acrylic acid. After being modified by acrylic acid, the properties of the therapeutic protein may change due to charge and hydrophobicity variations. Acrylic acid was detected to migrate from syringes (Vendor X) into a therapeutic protein solution (at a concentration around 5 μg/mL). In this study, we discovered that acrylic acid can modify proteins at three different sites: (1) the lysine side chain, 2) the N-terminus, and 3) the histidine side chain, by the Michael reaction. In this report, the direct interactions between acrylic acid leachable and a biopharmaceutical product were demonstrated and the reaction mechanism was proposed.

  4. Bond strength test of acrylic artificial teeth with prosthetic base

    Directory of Open Access Journals (Sweden)

    Erna Kurnikasari

    2008-07-01

    Full Text Available Denture consists of acrylic artificial teeth and acrylic prothesis base bond chemically with a bond strength of 315 kgF/cm2. Most of the commercial acrylic artificial teeth do not specify their specifications and all of those acrylic artificial teeth do not include mechanical data (bond strength. The aim of this study is to discover which acrylic artificial teeth meet ADA specification no. 15. This study is a descriptive analytic study performed to 5 acrylic artificial teeth posterior brands commonly used by dentists and technicians. From each brand, 3 sample teeth were taken. The acrylic artificial teeth were prepared into a rectangular shape and were attached between acrylic prothesis base simulation and jigs. The sample was given tensile load using a Universal Testing Machine. The amount of force that causes the teeth to be fractured was recorded and the bond strength was calculated. The results of the study show that the average value for the five acrylic artificial teeth for the five brands were as followed: Brand A, 125.993 kgF/cm2; B, 188.457 kgF/cm2; C, 175.880 kgF/cm2; D, 153.373 kgF/cm2; E, 82.839 kgF/cm2. The data can be tested statistically by using One Way ANOVA test and Dunnett test (alpha = 0.05. From the study, it is concluded that the five acrylic artificial teeth have a bond strength below the ADA specification no. 15.

  5. Biocompatibility of acrylic resin after being soaked in sodium hypochlorite

    Directory of Open Access Journals (Sweden)

    Nike Hendrijatini

    2009-06-01

    Full Text Available Background: Acrylic resin as basic material for denture will stay on oral mucosa for a very long time. The polymerization of acrylic resin can be performed by conventional method and microwave, both produce different residual monomer at different toxicity. Acrylic resin can absorb solution, porous and possibly absorb disinfectantt as well, that may have toxic reaction with the tissue. Sodium Hypochlorite as removable denture disinfectant can be expected to be biocompatible to human body. The problem is how biocompatible acrylic resin which has been processed by conventional method and microwave method after being soaked in sodium hypochlorite solution. Purpose: The aim of this study was to understand in vitro biocompatibility of acrylic resin which has polimerated by conventional method and microwave after being soaked in sodium hypochlorite using tissue culture. Methods: Four groups of acrylic resin plate were produced, the first group was acrylic resin plate with microwave polymeration and soaked in sodium hypochlorite, the second group was acrylic resin plate with microwave polymeration but not soaked, the thirdwas one with conventional method and soaked and the last group was one with conventional method but not soaked, and in 1 control group. Each group consists of 7 plates. Biocompatibility test was performed in-vitro on each material using fibroblast tissue culture (BHK-21 cell-line. Result: The percentage between living cells and dead cells from materials which was given acrylic plate was wounted. The data was analyzed statistically with T test. Conclusion: The average value of living cells is higher in acrylic resin poimerization using microwave method compared to conventional method, in both soaked and non soaked (by sodium hypochlorite group. This means that sodium hypochlorite 0.5% was biocompatible to the mouth mucosa as removable denture disinfectant for 10 minutes soaking and washing afterwards.

  6. FIXED OR REMOVABLE APPLIANCE FOR EARLY ORTHODONTIC TREATMENT OF FUNCTIONAL ANTERIOR CROSSBITE.

    Science.gov (United States)

    Wiedel, Anna-Paulina

    2015-01-01

    Anterior crossbite with functional shift also called pseudo Class III is a malocclusion in which the incisal edges of one or more maxillary incisors occlude with the incisal edges of the mandibular incisors in centric relationship: the mandible and mandibular incisors are then guided anteriorly in central occlusion resulting in an anterior crossbite. Early correction, at the mixed dentition stage, is recommended, in order to avoid a compromising dentofacial condition which could result in the development of a true Class III malocclusion and temporomandibular symptoms. Various treatment options are available. The method of choice for orthodontic correction of this condition should not only be clinically effective, with long-term stability, but also cost-effective and have high patient acceptance, i.e. minimal perceived pain and discomfort. At the mixed dentition stage, the condition may be treated by fixed (FA) or removable appliance (RA). To date there is insufficient evidence to determine the preferred method. The overall aim of this thesis was therefore to compare and evaluate the use of FA and RA for correcting anterior crossbite with functional shift in the mixed dentition, with special reference to clinical effectiveness, stability, cost-effectiveness and patient perceptions. Evidence-based, randomized controlled trial (RCT) methodology was used, in order to generate a high level of evidence. The thesis is based on the following studies: The material comprised 64 patients, consecutively recruited from the Department of Orthodontics, Faculty of Odontology, Malmö University, Sweden and from one Public Dental Health Service Clinic in Malmö, Skane County Council, Sweden. The patients were no syndrome and no cleft patients. The following inclusion criteria were applied: early to late mixed dentition, anterior crossbite affecting one or more incisors with functional shift, moderate space deficiency in the maxilla, no inherent skeletal Class III discrepancy, ANB

  7. Stability of edge states and edge magnetism in graphene nanoribbons

    OpenAIRE

    Kunstmann, Jens; Özdoğan, Cem; Quandt, Alexander; Fehske, Holger

    2010-01-01

    We critically discuss the stability of edge states and edge magnetism in zigzag edge graphene nanoribbons (ZGNRs). We point out that magnetic edge states might not exist in real systems, and show that there are at least three very natural mechanisms - edge reconstruction, edge passivation, and edge closure - which dramatically reduce the effect of edge states in ZGNRs or even totally eliminate them. Even if systems with magnetic edge states could be made, the intrinsic magnetism would not be ...

  8. Comparison of the Retinal Straylight in Pseudophakic Eyes with PMMA, Hydrophobic Acrylic, and Hydrophilic Acrylic Spherical Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Ya-wen Guo

    2014-01-01

    Full Text Available Purpose. To investigate the intraocular straylight value after cataract surgery. Methods. In this study, 76 eyes from 62 patients were subdivided into three groups. A hydrophobic acrylic, a hydrophilic acrylic, and a PMMA IOL were respectively, implanted in 24 eyes, 28 eyes, and 24 eyes. Straylight was measured using C-Quant at 1 week and 1 month postoperatively in natural and dilated pupils. Results. The hydrophilic acrylic IOLs showed significantly lower straylight values than those of the hydrophobic acrylic IOLs in dilated pupils at 1 week and 1 month after surgery (P0.05. Moreover, no significant difference was found in straylight between natural and dilated pupils in each group at 1 week and 1 month postoperatively (P>0.05. Conclusions. Although the hydrophobic acrylic IOL induced more intraocular straylight, straylight differences among the 3 IOLs were minimal. Pupil size showed no effect on intraocular straylight; the intraocular straylight was stable 1 week after surgery.

  9. Nanoindentation near the edge

    Science.gov (United States)

    J.E. Jakes; C.R. Frihart; J.F. Beecher; R.J. Moon; P.J. Resto; Z.H. Melgarejo; O.M. Saurez; H. Baumgart; A.A. Elmustafa; D.S. Stone

    2009-01-01

    Whenever a nanoindent is placed near an edge, such as the free edge of the specimen or heterophase interface intersecting the surface, the elastic discontinuity associated with the edge produces artifacts in the load-depth data. Unless properly handled in the data analysis, the artifacts can produce spurious results that obscure any real trends in properties as...

  10. Toughening epoxy acrylate with polyurethane acrylates and hyper-branched polyester in three dimensional printing

    Science.gov (United States)

    Fang, Chao; Li, Ning; Liu, Yang; Lu, Gang

    2018-05-01

    In order to improve the toughness of epoxy acrylate (EA) in three dimensional printing (3D-printing), bifunctional polyurethane acrylate (PUA) and trifunctional PUA were firstly blended with EA. The multi-indicators orthogonal experiment, designed with the indicators of tensile strength, elongation at break and impact strength, was used to find out the optimal formulation. Then, hyper-branched polyesters (HBPs) was added to improve the toughness of the photocurable system. The microstructures of the cured specimens were characterized by optical microscopy and scanning electron microscopy. By analyzing their mechanical properties and microstructures, it was revealed that the best addition amounts of HBP are 10 wt%. Results indicated that their toughness improved a lot comparing with pure EA. The changes of mechanical properties were characterized by DMA. The addition of HBP could cause a loss in stiffness, elasticity modulus and thermostability.

  11. Use of Acrylic Acid Sodium Acrylate Polymer to Maintain Cocoa Seed Viability

    Directory of Open Access Journals (Sweden)

    Pudji Rahardjo

    2010-08-01

    Full Text Available The main problem of cocoa seed storage is moisture content of the seeds because cocoa seeds will germinate if cocoa seeds moisture content is high. The objective of this research is to maintain the cocoa seeds viability in storage using acrylic acid sodium acrylate polymer (AASAP. The function of AASAP is to absorb humidity in storage due to their ability to retain water and to prevent water loss. The experiment was conducted in a laboratory of Indonesian Coffee and Cocoa Research Institute and in Kaliwining Experimental Garden. This experiment was arranged by factorial randomized complete design, in wich AASAP dosages 0%; 0.1% (0.1 g/100 seeds; 0.2% (0.2 g/100 seeds, 0.3% (0.3 g/100 seeds, 0,4% (0,4g/100 seeds, combined with seeds storage period 1, 2, 3 and 4 weeks. The experiment used 3 replications and each repli cation used 100 seeds. Parameter of observation consisted of percentage of seeds germinated in storage, percentage of seeds infected by fungi in storage, seeds moisture content, percentage of seeds germination after storage, and early growth of cocoa seedlings. The results of the experiment showed that AASAP application with some dosages cocoa seeds storage cause to germinate in storage during 2 weeks. AASAP application with some dosages in cocoa seeds storage for 2 weeks would not result in infection by fungi and did not significantly affect seed germination after storage for 1, 2 and 4 weeks, and percentage of germination of cocoa seed after storage for 3 weeks decreased with increase dosage of AASAP. Higher dosage of AASAP would reduce early growth of cocoa seedling. Key words : Theobroma cacao, seed, acrylic acid sodium acrylate, seed storage, viabilty.

  12. Electrochemical characterization of aminated acrylic conducting polymer

    International Nuclear Information System (INIS)

    Rashid, Norma Mohammad; Heng, Lee Yook; Ling, Tan Ling

    2015-01-01

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study

  13. Electrochemical characterization of aminated acrylic conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Norma Mohammad [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Heng, Lee Yook [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ling, Tan Ling [Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  14. Dynamical mechanical analysis of photocrosslinked hyperbranched urethane acrylates

    Directory of Open Access Journals (Sweden)

    BRANKO DUNJIC

    2004-06-01

    Full Text Available A series of acrylate functionalized samples based on hyperbranched hydroxy-terminated polyesters with different molecular weights and different degrees of acrylation were synthesized. The obtained urethane acrylates were slightly yellow viscose liquids. Their composition was characterized by FTIR and 1H-NMR spectroscopy and their molecular weights were measured by GPC. All the synthesized samples were diluted with 25 wt.% 1,4-butanediol dimethacrylate (BDDM. The rheological properties of the uncured samples and the dynamic mechanical properties of the UV cured samples were examined. All the samples exhibit Newtonian behavior, which indicates the absence of physical entanglements in these polymers. The viscosity increases with increasing number of acrylic groups per molecule. The glass transition temperature of the UV cured samples increases with increasing the number of acrylic groups per molecule. The value of the storage modulus in the rubber-elastic plateau and the cross-link density increase with increasing number of acrylic groups per molecule. The formed networks are inhomogeneous and the residual unsaturation is the highest in the samples with the largest number of acrylic groups per molecule.

  15. COMPARATIVE ANALYSIS OF WATER SORPTION BY DIFFERENT ACRYLIC MATERIALS

    Directory of Open Access Journals (Sweden)

    Milena Kostić

    2014-06-01

    Full Text Available Acrylic materials are used daily for the production of mobile dental restorations and orthodontic appliances. The presence of residual monomer, as a product of incomplete polymerisation of material, results in more porous structure of the material, which greatly reduces the mechanical and physical quality of the acrylic restorations and increases the absorption of liquids. The aim of this study was to examine the water absorption of different types of resin material. In the study it was assumed that the cold polymerized acrylates show a greater potential for absorbing fluid from the environment in relation to the hot polymerized acrylic. The study included two hot and two cold polymerized acrylates, and cold polymerized acrylate impregnated with aesthetic pearls. In order to determine the degree of water absorption, the mass of the samples was measured before and after one day, seven days and thirty days of immersion in a water bath of body temperature. The tested hot and cold polymerized acrylates after immersion in water bath showed standard values of water absorption. The degree of water absorption was not significantly influenced by the type and manner of polymerisation. Water absorption values were significantly higher after seven days and thirty days of water storage relative to the observational period of one day.

  16. Dynamically formed hydrous zirconium (IV) oxide-polyelectrolyte membranes. III: Poly(acrylic acid) and substituted poly(acrylic acid) homo, co and terpolymer membranes

    International Nuclear Information System (INIS)

    Van Reenen, A.J.; Sanderson, R.D.

    1989-01-01

    A series of acrylic acid and substituted acrylic acid homo, co and terpolymers was synthesised. These polymers were used as polyelectrolytes in dynamically formed hydrous zirconium (iv) oxide-polyelectrolyte membranes. Substitution of the acrylic acid α-hydrogen was done to increase the number of carboxylic acid groups per monomer unit and to change the acid strength of acrylic acid carboxylic acid group. None of these changes improved the salt rejection of these membranes over that of commercially used poly(acrylic acid). Improvement in rejection was found when a hydrophobic comonomer, vinyl acetate, was used in conjunction with acrylic acid in a copolymer dynamic membrane. 16 refs., 6 figs., 1 tab

  17. Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

    2015-04-10

    Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

  18. Chemo-enzymatic synthesis route to poly(glucosyl-acrylates) using glucosidase from almonds

    NARCIS (Netherlands)

    Kloosterman, Wouter M. J.; Roest, Steven; Priatna, Siti R.; Stavila, Erythrina; Loos, Katja

    2014-01-01

    Novel types of glucosyl-acrylate monomers are obtained by beta-glucosidase from almond catalyzed glycosidation reaction. The saccharide-acrylate monomers were synthesized by reaction of D-glucose with hydroxyl functional acrylates: 2-hydroxyethyl acrylate (2-HEA), 2-hydroxyethyl methacrylate

  19. An edge pedestal model

    International Nuclear Information System (INIS)

    Stacev, W.M.

    2001-01-01

    A new model for calculation of the gradient scale lengths in the edge pedestal region and of the edge transport barrier width in H-mode tokamak plasmas will be described. Model problem calculations which demonstrate the promise of this model for predicting experimental pedestal properties will be discussed. The density and Prague gradient scale lengths (L) in the edge are calculated from the particle and ion and electron energy radial transport equations, making use of (presumed) known particle and energy fluxes flowing across the edge transport barrier from the core into the SOL and of edge transport coefficients. The average values of the particle and heat fluxes in the edge transport barrier are calculated in terms of the fluxes crossing into the SOL and the atomic physics reaction rates (ionisation, charge-exchange, elastic scattering, impurity radiation) in the edge by integrating the respective transport equations from the pedestal to the separatrix. An important implication of this model is that the pedestal gradient scale lengths depend not just on local pedestal platers properties but also on particle and energy fluxes from the core plasma and on recycling neutral fluxes that penetrate into the plasma edge, both of which in turn depend on the pedestal properties. The MHD edge pressure gradient constraint α≤ α C is used to determine the pressure width of the edge transport barrier, Δ TB = Δ TB (α c ). Three different models for the MHD edge pressure gradient constraint have been investigated: (1) nominal ideal ballooning mode theory, (2) ballooning mode theory taking into account the edge geometry and shear to access He second stability region; and pedestal β-limit theory when the ballooning modes are stabilised by diamagnetic effects. A series of calculations have been made for a DIII-D model problem. The calculated gradient scale lengths and edge transport barrier widths are of the magnitude of values observed experimentally, and certain trends

  20. Automated batch emulsion copolymerization of styrene and butyl acrylate

    NARCIS (Netherlands)

    Mballa Mballa, M.A.; Schubert, U.S.; Heuts, J.P.A.; Herk, van A.M.

    2011-01-01

    This article describes a method for carrying out emulsion copolymerization using an automated synthesizer. For this purpose, batch emulsion copolymerizations of styrene and butyl acrylate were investigated. The optimization of the polymerization system required tuning the liquid transfer method,

  1. [Treatment of acrylate wastewater by electrocatalytic reduction process].

    Science.gov (United States)

    Yu, Li-Na; Song, Yu-Dong; Zhou, Yue-Xi; Zhu, Shu-Quan; Zheng, Sheng-Zhi; Ll, Si-Min

    2011-10-01

    High-concentration acrylate wastewater was treated by an electrocatalytic reduction process. The effects of the cation exchange membrane (CEM) and cathode materials on acrylate reduction were investigated. It indicated that the acrylate could be reduced to propionate acid efficiently by the electrocatalytic reduction process. The addition of CEM to separator with the cathode and anode could significantly improve current efficiency. The cathode materials had significant effect on the reduction of acrylate. The current efficiency by Pd/Nickel foam, was greater than 90%, while those by nickel foam, the carbon fibers and the stainless steel decreased successively. Toxicity of the wastewater decreased considerably and methane production rate in the biochemical methane potential (BMP) test increased greatly after the electrocatalytic reduction process.

  2. Antimicrobial activity of poly(acrylic acid) block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Gratzl, Günther, E-mail: guenther.gratzl@jku.at [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Paulik, Christian [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Hild, Sabine [Johannes Kepler University Linz, Institute of Polymer Science, Altenberger Str. 69, 4040 Linz (Austria); Guggenbichler, Josef P.; Lackner, Maximilian [AMiSTec GmbH and Co. KG, Leitweg 13, 6345 Kössen, Tirol (Austria)

    2014-05-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed.

  3. Antimicrobial activity of poly(acrylic acid) block copolymers

    International Nuclear Information System (INIS)

    Gratzl, Günther; Paulik, Christian; Hild, Sabine; Guggenbichler, Josef P.; Lackner, Maximilian

    2014-01-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed

  4. Fracture toughness of heat cured denture base acrylic resin modified with Chlorhexidine and Fluconazole as bioactive compounds.

    Science.gov (United States)

    Al-Haddad, Alaa; Vahid Roudsari, Reza; Satterthwaite, Julian D

    2014-02-01

    This study investigated the impact of incorporating Chlorhexidine and Fluconazole as bioactive compounds on the fracture toughness of conventional heat cured denture base acrylic resin material (PMMA). 30 single edge-notched (SEN) samples were prepared and divided into three groups. 10% (mass) Chlorhexidine and 10% (mass) Diflucan powder (4.5% mass Fluconazole) were added to heat cured PMMA respectively to create the two study groups. A third group of conventional heat cured PMMA was prepared as the control group. Fracture toughness (3-point bending test) was carried out for each sample and critical force (Fc) and critical stress intensity factor (KIC) values measured. Data were subject to parametric statistical analysis using one-way ANOVA and Post hoc Bonferroni test (p=0.05). Fluconazole had no significant effect on the fracture toughness of the PMMA while Chlorhexidine significantly reduced the KIC and therefore affected the fracture toughness. When considering addition of a bioactive material to PMMA acrylic, Chlorhexidine will result in reduced fracture toughness of the acrylic base while Fluconazole has no effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Advances in acrylic-alkyd hybrid synthesis and characterization

    Science.gov (United States)

    Dziczkowski, Jamie

    2008-10-01

    In situ graft acrylic-alkyd hybrid resins were formed by polymerizing acrylic and acrylic-mixed monomers in the presence of alkyds by introduction of a free radical initiator to promote graft formation. Two-dimensional NMR, specifically gradient heteronuclear multiple quantum coherence (gHMQC), was used to clarify specific graft sites of the hybrid materials. Both individual and mixed-monomer systems were produced to determine any individual monomer preferences and to model current acrylic-alkyd systems. Different classes of initiators were used to determine any initiator effects on graft location. The 2D-NMR results confirm grafting at doubly allylic hydrogens located on the fatty acid chains and the polyol segment of the alkyd backbone. The gHMQC spectra show no evidence of grafting across double bonds on either pendant fatty acid groups or THPA unsaturation sites for any of the monomer or mixed monomer systems. It was also determined that choice of initiator has no effect on graft location. In addition, a design of experiments using response surface methodology was utilized to obtain a better understanding of this commercially available class of materials and relate both the chemical and physical properties to one another. A Box-Behnkin design was used, varying the oil length of the alkyd phase, the degree of unsaturation in the polyester backbone, and acrylic to alkyd ratio. Acrylic-alkyd hybrid resins were reduced with an amine/water mixture. Hydrolytic stability was tested and viscoelastic properties were obtained to determine crosslink density. Cured films were prepared and basic coatings properties were evaluated. It was found that the oil length of the alkyd is the most dominant factor for final coatings properties of the resins. Acrylic to alkyd ratio mainly influences the resin properties such as acid number, average molecular weight, and hydrolytic stability. The degree of unsaturation in the alkyd backbone has minimal effects on resin and film

  6. Modification of hydrophobic acrylic intraocular lens with poly(ethylene glycol) by atmospheric pressure glow discharge: A facile approach

    International Nuclear Information System (INIS)

    Lin Lin; Wang Yao; Huang Xiaodan; Xu Zhikang; Yao Ke

    2010-01-01

    To improve the anterior surface biocompatibility of hydrophobic acrylic intraocular lens (IOL) in a convenient and continuous way, poly(ethylene glycol)s (PEGs) were immobilized by atmospheric pressure glow discharge (APGD) treatment using argon as the discharge gas. The hydrophilicity and chemical changes on the IOL surface were characterized by static water contact angle and X-ray photoelectron spectroscopy to confirm the covalent binding of PEG. The morphology of the IOL surface was observed under field emission scanning electron microscopy and atomic force microscopy. The surface biocompatibility was evaluated by adhesion experiments with platelets, macrophages, and lens epithelial cells (LECs) in vitro. The results revealed that the anterior surface of the PEG-grafted IOL displayed significantly and permanently improved hydrophilicity. Cell repellency was observed, especially in the PEG-modified IOL group, which resisted the attachment of platelets, macrophages and LECs. Moreover, the spread and growth of cells were suppressed, which may be attributed to the steric stabilization force and chain mobility effect of the modified PEG. All of these results indicated that hydrophobic acrylic IOLs can be hydrophilic modified by PEG through APGD treatment in a convenient and continuous manner which will provide advantages for further industrial applications.

  7. Multidisciplinary management of anterior diastemata

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; Herkrath, Fernando José; Franco, Eduardo Jacomino

    2007-01-01

    Anterior diastemata may compromise the harmony of a patient's smile. Consideration of etiologic factors, previous gingival conditioning, and individual treatment planning are essential in the proper management of anterior diastemata. An integrated orthodontic-restorative approach may enhance the ...

  8. Anterior Urethral Valves

    Directory of Open Access Journals (Sweden)

    Vidyadhar P. Mali

    2006-07-01

    Full Text Available We studied the clinical presentation and management of four patients with anterior urethral valves; a rare cause of urethral obstruction in male children. One patient presented antenatally with oligohydramnios, bilateral hydronephrosis and bladder thickening suggestive of an infravesical obstruction. Two other patients presented postnatally at 1 and 2 years of age, respectively, with poor stream of urine since birth. The fourth patient presented at 9 years with frequency and dysuria. Diagnosis was established on either micturating cystourethrogram (MCU (in 2 or on cystoscopy (in 2. All patients had cystoscopic ablation of the valves. One patient developed a postablation stricture that was resected with an end-to-end urethroplasty. He had an associated bilateral vesicoureteric junction (VUJ obstruction for which a bilateral ureteric reimplantation was done at the same time. On long-term follow-up, all patients demonstrated a good stream of urine. The renal function is normal. Patients are continent and free of urinary infections. Anterior urethral valves are rare obstructive lesions in male children. The degree of obstruction is variable, and so they may present with mild micturition difficulty or severe obstruction with hydroureteronephrosis and renal impairment. Hence, it is important to evaluate the anterior urethra in any male child with suspected infravesical obstruction. The diagnosis is established by MCU or cystoscopy and the treatment is always surgical, either a transurethral ablation or an open resection. The long-term prognosis is good.

  9. The sensitizing capacity of multifunctional acrylates in the guinea pig.

    Science.gov (United States)

    Björkner, B

    1984-10-01

    The multifunctional acrylates used in ultraviolet (UV) curable resins act as cross-linkers and "diluents". They are usually based on di(meth)acrylate esters of dialcohols or tri- and tetra-acrylate esters of polyalcohols. In UV-curable coatings, the most commonly used are pentaerythritol triacrylate (PETA), trimethylolpropane triacrylate (TMPTA) and 1,6-hexanediol diacrylate (HDDA). In other uses, such as dental composite resin materials, the dimethacrylic monomers based on n-ethylene glycol are the most useful. The sensitizing capacity of various multifunctional acrylates and their cross-reactivity pattern have been investigated with the guinea pig maximization test. The tests show that BUDA (1,4-butanediol diacrylate) and HDDA are moderate to strong sensitizers and that they probably cross-react with each other. The n-ethylene glycol diacrylates and methacrylates tested are weak or non-sensitizers. Tripropylene glycol diacrylate (TPGDA) is a moderate and neopentyl glycol diacrylate (NPGDA) a strong sensitizer, whereas neopentyl glycol dimethacrylate is a non-sensitizer. The commercial PETA is a mixture of pentaerythritol tri- and tetra-acrylate (PETA-3 and PETA-4). PETA-3 is a much stronger sensitizer than PETA-4. Simultaneous reactions were seen between PETA-3, PETA-4 and TMPTA. The oligotriacrylate OTA 480 is a moderate sensitizer, but no concomitant reactions were seen with PETA-3, PETA-4 or TMPTA. Of the multifunctional acrylates tested, the di- and triacrylic compounds should be regarded as potent sensitizers. The methacrylated multifunctional acrylic compounds are weak or non-sensitizers.

  10. Clinical Aspects of Combination of Ceramic and Acrylic Occlusal Surfaces

    Directory of Open Access Journals (Sweden)

    Z. Ozhohan

    2017-03-01

    Full Text Available The objective of the research was to develop and substantiate the methods of constructing the occlusal surfaces when manufacturing aesthetic fixed restorations through the combination of different materials. Materials and methods. The study included 65 patients with ceramic and acrylic occlusal surfaces of aesthetic fixed dental prostheses. Group I included 21 patients with a combination of ceramic and acrylic occlusal surfaces. Group II included 22 patients with a combination of ceramic occlusal surfaces. Group III included 22 patients with a combination of acrylic occlusal surfaces. The patients were observed 3, 6 and 12 months after prosthetic repair. Results. The greatest increase in the occlusal contact surface area of fixed restorations was observed in Group I, that is, when combining dental prostheses with ceramic and acrylic occlusal surfaces. Considering uneven abrasion of the occlusal surfaces, we do not recommend to combine different materials when veneering the occlusal surface of the antagonistic teeth. Conclusions. This study demonstrated the important role of the correct combination of materials when veneering the occlusal surfaces. Physical and chemical properties of materials, namely the abrasion resistance play a significant role in the long-term denture functioning. The smallest increase in the occlusal contact surface area was observed in Group II when combining ceramic occlusal surfaces. It was due to a good abrasion resistance of ceramics as compared to acrylic resin as well as the presence of the glazed layer which prevents the premature abrasion of the occlusal surfaces of the antagonistic teeth due to lower surface roughness. The combination of acrylic resin and ceramics when constructing the occlusal surfaces of fixed restorations in Group I demonstrated the highest rate of the increase in the occlusal contact surface area – 9.93%. It was due to a low hardness of acrylic resin and its high surface roughness. In

  11. Edge effects in composites

    International Nuclear Information System (INIS)

    Guz, A.N.; Kokhanenko, Yu.V.

    1995-01-01

    In the present article we survey papers on edge effects investigated by the rigorous approach. We interpret edge effects as stressed states created in a composite as a result of zones in which the stresses exhibit a rapidly changing behavior in comparison with the slow variation of the stresses outside such zones. Here the range of the edge effect is defined as the distance from the point of its inception to the boundary of the edge zone in a given direction. The transition of the stresses to the slowly varying state is determined within prescribed error limits. The size and configuration of the edge zone depends on the tolerated error. Clearly, the main difficulty associated with the rigorous approach is finding solutions of the elasticity problems. The finite-difference approach is suggested for the approximate solution of these problems. In light of the comparative time consumption of the finite-difference approach, it is best directed at certain classes of problems rather than at particular individual problems. Not too many papers on the investigation of edge effects by the rigorous approach have been published to date. Below, following in their footsteps, we formulate edge effect problems in composites, determine classes of problems, and investigate edge effects in composite materials and structural elements using them in Cartesian (planar and three-dimensional problems) and cylindrical (axisymmetric problems) coordinate frames. We note that the division of approaches to the study of edge effects into qualitative (nonrigorous) and quantitative (rigorous) reflects the authors own point of view. Of course, other schemes of classification of the approaches to the investigation of the regions of rapidly varying states in composites are possible

  12. Edge colouring by total labellings

    DEFF Research Database (Denmark)

    Brandt, Stephan; Rautenbach, D.; Stiebitz, M.

    2010-01-01

    We introduce the concept of an edge-colouring total k-labelling. This is a labelling of the vertices and the edges of a graph G with labels 1, 2, ..., k such that the weights of the edges define a proper edge colouring of G. Here the weight of an edge is the sum of its label and the labels of its...

  13. Adobe Edge Quickstart Guide

    CERN Document Server

    Labrecque, Joseph

    2012-01-01

    Adobe Edge Quickstart Guide is a practical guide on creating engaging content for the Web with Adobe's newest HTML5 tool. By taking a chapter-by-chapter look at each major aspect of Adobe Edge, the book lets you digest the available features in small, easily understandable chunks, allowing you to start using Adobe Edge for your web design needs immediately. If you are interested in creating engaging motion and interactive compositions using web standards with professional tooling, then this book is for you. Those with a background in Flash Professional wanting to get started quickly with Adobe

  14. New acrylic resin composite with improved thermal diffusivity.

    Science.gov (United States)

    Messersmith, P B; Obrez, A; Lindberg, S

    1998-03-01

    Studies have shown that physical characteristics of denture base materials may affect patient acceptance of denture prostheses by altering sensory experience of food during mastication. Thermal diffusivity is one material property that has been cited as being important in determining gustatory response, with denture base acrylic resins having low thermal diffusivity compared with denture base metal alloys. This study prepared and characterized experimental acrylic resin composite material with increased thermal diffusivity. Sapphire (Al2O3) whiskers were added to conventional denture base acrylic resin during processing to achieve loadings of 9.35% and 15% by volume. Cylindrical test specimens containing an embedded thermocouple were used to determine thermal diffusivity over a physiologic temperature range (0 degree to 70 degrees C). Thermal diffusivities of the sapphire containing composites were found to be significantly higher than the unmodified acrylic resin. Thermal diffusivity was found to increase in proportion to the volume percentage of sapphire filler, which suggested that the high aspect ratio ceramic particles formed a pathway for heat conduction through the insulating polymer matrix. The thermal diffusivity of denture base acrylic resin was increased by the addition of thermally conducting sapphire whiskers.

  15. Perawatan Ortodontik Gigitan Terbuka Anterior

    Directory of Open Access Journals (Sweden)

    Yuniar Zen

    2014-06-01

    Full Text Available Perawatan gigitan terbuka anterior telah lama dianggap sebagai tantangan bagi ortodontis. Prevalensi gigitan terbuka anterior antara 3,5% hingga 11% terdapat pada berbagai usia dan kelompok etnis, serta ada sekitar 17% pasien ortodonti memiliki gigitan terbuka. Stabilitas hasil perawatan gigitan terbuka anterior sangat sulit, karena adanya kombinasi diskrepansi anteroposterior dengan gigitan terbuka skeletal sehingga dibutuhkan tingkat keterampilan diagnosis dan klinis yang tinggi. Etiologi gigitan terbuka anterior sangat kompleks karena dapat melibatkan skeletal, dental, dan faktor-faktor habitual. Eliminasi faktor etiologi merupakan hal yang penting dalam perawatan gigitan terbuka anterior. Berbagai cara perawatan untuk koreksi gigitan terbuka anterior diantaranya bedah ortognatik dan perawatan ortodontik kamuflase, seperti high-pull headgear, chincup, bite blocks, alatfungsional, pencabutan gigi, multi-loop edgewise archwires dan mini implan. Stabilitas hasil perawatan adalah kriteria yang paling penting dalam menentukan cara perawatan gigitan terbuka anterior. Orthodontic Treatment of Anterior Open Bite. An anterior open bite therapy has long been considered a challenge to orthodontist. The prevalence of anterior openbite range from 3,5 % to 11% among various age and ethnic groups and it has been shown that approximately 17% of orthodontic patients have open bite. Stability of treatment result of anterior open bite with well-maintained results is difficult, because the combination of anteroposteriorly discrepancy with skeletal open bite requires the highest degree of diagnostic and clinical skill. The etiology is complex, potentially involving skeletal, dental and habitual factors. The importance of an anterior open bite therapy is to eliminate the cause of the open bite. Various treatment modalities for the correction of an anterior open bite have been proposed, orthognatic surgery and orthodontic camouflage treatment such as high

  16. Anterior knee pain

    International Nuclear Information System (INIS)

    LLopis, Eva; Padron, Mario

    2007-01-01

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries

  17. Anterior knee pain

    Energy Technology Data Exchange (ETDEWEB)

    LLopis, Eva [Hospital de la Ribera, Alzira, Valencia (Spain) and Carretera de Corbera km 1, 46600 Alzira Valencia (Spain)]. E-mail: ellopis@hospital-ribera.com; Padron, Mario [Clinica Cemtro, Ventisquero de la Condesa no. 42, 28035 Madrid (Spain)]. E-mail: mario.padron@clinicacemtro.com

    2007-04-15

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries.

  18. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  19. Adobe Edge Preview 3

    CERN Document Server

    Grover, Chris

    2011-01-01

    Want to use an Adobe tool to design animated web graphics that work on iPhone and iPad? You've come to the right book. Adobe Edge Preview 3: The Missing Manual shows you how to build HTML5 graphics using simple visual tools. No programming experience? No problem. Adobe Edge writes the underlying code for you. With this eBook, you'll be designing great-looking web elements in no time. Get to know the workspace. Learn how Adobe Edge Preview 3 performs its magic.Create and import graphics. Make drawings with Edge's tools, or use art you designed in other programs.Work with text. Build menus, lab

  20. Pavement edge treatment.

    Science.gov (United States)

    2013-01-01

    Four projects were built over two construction seasons using special devices attached to the paving machine that produces a 30 slope on the outside pavement edge instead of the near vertical drop-off common with conventional paving equipment. This ...

  1. Edge Simulation Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Krasheninnikov, Sergei I. [Univ. of California, San Diego, CA (United States); Angus, Justin [Univ. of California, San Diego, CA (United States); Lee, Wonjae [Univ. of California, San Diego, CA (United States)

    2018-01-05

    The goal of the Edge Simulation Laboratory (ESL) multi-institutional project is to advance scientific understanding of the edge plasma region of magnetic fusion devices via a coordinated effort utilizing modern computing resources, advanced algorithms, and ongoing theoretical development. The UCSD team was involved in the development of the COGENT code for kinetic studies across a magnetic separatrix. This work included a kinetic treatment of electrons and multiple ion species (impurities) and accurate collision operators.

  2. Preparation and Characterization of Acrylic Primer for Concrete Substrate Application

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2016-01-01

    Full Text Available This study dealt with the properties of acrylic primer for concrete substrate using acrylic syrup, made from a methyl methacrylate monomer solution of terpolymers. Terpolymer systems consisting of methyl methacrylate (MMA, 2-ethylhexyl acrylate (2-EHA, and methacrylic acid (MAA with different chemical composition ratios of MMA and 2-EHA were synthesized through bulk polymerization using azobisisobutyronitrile (AIBN as initiator. The terpolymer composition is characterized by FTIR, 1H NMR, DSC, TGA, and SEM. The glass transition temperature and the thermal stability increased with increasing amounts of MMA in the terpolymer backbone. The effect of chemical composition of terpolymers on physicomechanical properties of primer films was investigated. However, increasing the amount of MMA in terpolymer backbone increased tensile and contact angle of primer films while elongation at break, water absorption, and bond strength are decreased. In particular, the primer syrup containing 65% 2-EHA has good bonding strength with concrete substrate around 1.1 MPa.

  3. Synthesis and characterization of waterborne polyurethane acrylate copolymers

    International Nuclear Information System (INIS)

    Sultan, Misbah; Bhatti, Haq Nawaz; Zuber, Mohammad; Barikani, Mehdi

    2013-01-01

    Polyurethane acrylate copolymers were synthesized by emulsion polymerization process. To reduce the environmental hazards, organic solvents were replaced by eco-friendly aqueous system. Concentration of polyurethane and acrylate monomer was varied to investigate the effect of chemical composition on performance properties of copolymers. FTIR spectroscopy was used as a key tool to record the chemical synthesis route. The synthesized copolymer emulsions were characterized by evaluating their particle size, viscosity, dry weight content, chemical and water resistance. Thermal decomposition was studied by thermogravimetric analysis. Scanning electron microscope was used to visualize the morphological structure of copolymers. The experimental results indicate better polyurethane acrylate compatibility till the ratio of 30/70. However, these copolymers exhibited synergistic effects between the two polymers and revealed a remarkable improvement in numerous coating properties

  4. Ultrasonic velocities, densities, and excess molar volumes of binary mixtures of N,N-dimethyl formamide with methyl acrylate, or ethyl acrylate, or butyl acrylate, or 2-ethyl hexyl acrylate at T = 308.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Kondaiah, M. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Sravana Kumar, D. [Dr. V.S. Krishna Govt. Degree College, Visakhapatnam, Andhra Pradesh (India); Sreekanth, K. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Krishna Rao, D., E-mail: krdhanekula@yahoo.co.in [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India)

    2011-12-15

    Highlights: > Positive values of V{sub m}{sup E}, indicate dispersion forces between acrylic esters and DMF. > V{sub m}{sup E} values compared with Redlich-Kister polynomial. > Partial molar volumes data conclude that weak interactions exist in the systems. > Measured velocity values compared with theoretical values obtained by polynomials. - Abstract: Ultrasonic velocities, u, densities, {rho}, of binary mixtures of N,N-dimethyl formamide (DMF) with methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), and 2-ethyl hexyl acrylate (EHA), including pure liquids, over the entire composition range have been measured at T = 308.15 K. Using the experimental results, the excess molar volume, V{sub m}{sup E}, partial molar volumes, V-bar {sub m,1}, V-bar{sub m,2}, and excess partial molar volumes, V-bar{sub m,1}{sup E}, V-bar{sub m,2}{sup E} have been calculated. Molecular interactions in the systems have been studied in the light of variation of excess values of calculated properties. The excess properties have been fitted to Redlich-Kister type polynomial and the corresponding standard deviations have been calculated. The positive values of V{sub m}{sup E} indicate the presence of dispersion forces between the DMF and acrylic ester molecules. Further theoretical values of sound velocity in the mixtures have been evaluated using various theories and have been compared with experimental sound velocities to verify the applicability of such theories to the systems studied. Theoretical ultrasonic velocity data have been used to study molecular interactions in the binary systems investigated.

  5. Technology and the use of acrylics for provisional dentine protection.

    Science.gov (United States)

    Kapusevska, Biljana; Dereban, Nikola; Popovska, Mirjana; Nikolovska, Julijana; Radojkova Nikolovska, Vеrа; Zabokova Bilbilova, Efka; Mijoska, Aneta

    2013-01-01

    Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue.

  6. Elastic modulus and flexural strength comparisons of high-impact and traditional denture base acrylic resins

    Directory of Open Access Journals (Sweden)

    Nour M. Ajaj-ALKordy

    2014-01-01

    Conclusion: Within the limitations of this study, it can be concluded that the high-impact acrylic resin is a suitable denture base material for patients with clinical fracture of the acrylic denture.

  7. Ionizing radiation method for forming acrylic pressure sensitive adhesives and coated substrates

    International Nuclear Information System (INIS)

    Dowbenko, R.; Christenson, R.M.

    1975-01-01

    Pressure-sensitive adhesive having improved adhesive properties are formed by subjecting a mixture comprising a monomer selected from the group consisting of alkyl acrylates, hydroxyalkyl acrylates, alkoxyalkyl acrylates, cyanoalkyl acrylates, alkyl methacrylates, hydroxyalkyl methacrylates, alkoxyalkyl methacrylates, cyanoalkyl methacrylates, N-alkoxymethylacrylamides, and N-alkoxymethylmethacrylamides, and a homopolymer or copolymer selected from the group consisting of polymers of alkyl acrylates, hydroxyalkyl acrylates, alkoxyalkyl acrylates, cyanoalkyl acrylates, alkyl methacrylates, hydroxyalkyl methacrylates, alkoxyalkyl methacrylates, cyanoalkyl methacrylates, acrylamide, methacrylamide, N-(substituted alkyl) acrylamides, N-(substituted alkyl) methacrylamides, alkyl acrylamides, alkyl methacrylamides, and N-alkoxymethylacrylamides and N-alkoxymethylmethacrylamides to ionizing irradiation. The adhesive material finds utility as binding resins in laminates, coatings on substrates, and as film adhesives. (U.S.)

  8. The development of epoxidised palm oil acrylate (EPOLA) and its applications

    International Nuclear Information System (INIS)

    Mohd Hilmi Mahmood

    1993-01-01

    The topics are discussed briefly. Acrylated palm oil is prepared through acrylation process, whereby, acrylic acid is introduced into oxirane group of the EPOP (epoxidised palm oil products), EPOLA (epoxidised palm oil products acrylate) was found curable when subjected to UV (ultrviolet) light giving soft coatings. EPOLA is used as radiation curable filler/sealer, radiation curable pressure sensitive adhesives and satisfactorily be coated on wood substrates (rubberwood parquets)

  9. The development of epoxidised palm oil acrylate (EPOLA) and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Mahmood, Mohd Hilmi [Nuclear Energy Unit, Bangi, Selangor (Malaysia)

    1994-12-31

    The topics are discussed briefly. Acrylated palm oil is prepared through acrylation process, whereby, acrylic acid is introduced into oxirane group of the EPOP (epoxidised palm oil products), EPOLA (epoxidised palm oil products acrylate) was found curable when subjected to UV (ultrviolet) light giving soft coatings. EPOLA is used as radiation curable filler/sealer, radiation curable pressure sensitive adhesives and satisfactorily be coated on wood substrates (rubberwood parquets).

  10. Bioengineered anterior cruciate ligament

    Science.gov (United States)

    Martin, Ivan (Inventor); Altman, Gregory (Inventor); Kaplan, David (Inventor); Vunjak-Novakovic, Gordana (Inventor)

    2001-01-01

    The present invention provides a method for producing an anterior cruciate ligament ex vivo. The method comprises seeding pluripotent stem cells in a three dimensional matrix, anchoring the seeded matrix by attachment to two anchors, and culturing the cells within the matrix under conditions appropriate for cell growth and regeneration, while subjecting the matrix to one or more mechanical forces via movement of one or both of the attached anchors. Bone marrow stromal cells are preferably used as the pluripotent cells in the method. Suitable matrix materials are materials to which cells can adhere, such as a gel made from collagen type I. Suitable anchor materials are materials to which the matrix can attach, such as Goinopra coral and also demineralized bone. Optimally, the mechanical forces to which the matrix is subjected mimic mechanical stimuli experienced by an anterior cruciate ligament in vivo. This is accomplished by delivering the appropriate combination of tension, compression, torsion, and shear, to the matrix. The bioengineered ligament which is produced by this method is characterized by a cellular orientation and/or matrix crimp pattern in the direction of the applied mechanical forces, and also by the production of collagen type I, collagen type III, and fibronectin proteins along the axis of mechanical load produced by the mechanical forces. Optimally, the ligament produced has fiber bundles which are arranged into a helical organization. The method for producing an anterior cruciate ligament can be adapted to produce a wide range of tissue types ex vivo by adapting the anchor size and attachment sites to reflect the size of the specific type of tissue to be produced, and also adapting the specific combination of forces applied, to mimic the mechanical stimuli experienced in vivo by the specific type of tissue to be produced. The methods of the present invention can be further modified to incorporate other stimuli experienced in vivo by the

  11. [Anterior guidance in complete dentures].

    Science.gov (United States)

    Dubreuil, J; Trevelo, A

    1990-01-01

    Although the anterior guidance in complete dentures is not really a guide, the arrangement of the anterior maxillary and mandibular prosthetic teeth, defines a propulsive line called the virtual anterior guidance, a part from the cinematic criterias. The influence of this guide on cuspal movement is superior, in all mandibular points, to the influence of the condylar pathway. If this line is not respected, the practitioner may have to do excessive grindings during occlusal adjustments.

  12. The Edge supersonic transport

    Science.gov (United States)

    Agosta, Roxana; Bilbija, Dushan; Deutsch, Marc; Gallant, David; Rose, Don; Shreve, Gene; Smario, David; Suffredini, Brian

    1992-01-01

    As intercontinental business and tourism volumes continue their rapid expansion, the need to reduce travel times becomes increasingly acute. The Edge Supersonic Transport Aircraft is designed to meet this demand by the year 2015. With a maximum range of 5750 nm, a payload of 294 passengers and a cruising speed of M = 2.4, The Edge will cut current international flight durations in half, while maintaining competitive first class, business class, and economy class comfort levels. Moreover, this transport will render a minimal impact upon the environment, and will meet all Federal Aviation Administration Part 36, Stage III noise requirements. The cornerstone of The Edge's superior flight performance is its aerodynamically efficient, dual-configuration design incorporating variable-geometry wingtips. This arrangement combines the benefits of a high aspect ratio wing at takeoff and low cruising speeds with the high performance of an arrow-wing in supersonic cruise. And while the structural weight concerns relating to swinging wingtips are substantial, The Edge looks to ever-advancing material technologies to further increase its viability. Heeding well the lessons of the past, The Edge design holds economic feasibility as its primary focus. Therefore, in addition to its inherently superior aerodynamic performance, The Edge uses a lightweight, largely windowless configuration, relying on a synthetic vision system for outside viewing by both pilot and passengers. Additionally, a fly-by-light flight control system is incorporated to address aircraft supersonic cruise instability. The Edge will be produced at an estimated volume of 400 aircraft and will be offered to airlines in 2015 at $167 million per transport (1992 dollars).

  13. Properties on the edge: graphene edge energies, edge stresses, edge warping, and the Wulff shape of graphene flakes

    International Nuclear Information System (INIS)

    Branicio, Paulo S; Jhon, Mark H; Gan, Chee Kwan; Srolovitz, David J

    2011-01-01

    It has been shown that the broken bonds of an unreconstructed graphene edge generate compressive edge stresses leading to edge warping. Here, we investigate edge energies and edge stresses of graphene nanoribbons with arbitrary orientations from armchair to zigzag, considering both flat and warped edge shapes in the presence and absence of hydrogen. We use the second generation reactive empirical bond order potential to calculate the edge energies and stresses for clean and hydrogenated edges. Using these energies, we perform a Wulff construction to determine the equilibrium shapes of flat graphene flakes as a function of hydrogen chemical potential. While edge stresses for clean, flat edges are compressive, they become tensile if allowed to warp. Conversely, we find that edge energies change little (∼1%) with edge warping. Hydrogenation of the edges virtually eliminates both the edge energy and edge stresses. For warped edges an approximately linear relationship is found between amplitudes and wavelengths. The equilibrium shape of a graphene flake is determined by the value of the hydrogen chemical potential. For very small (and large) values of it the flakes have a nearly hexagonal (dodecagon) shape with zigzag oriented edges, while for intermediate values graphene flakes are found with complex shapes

  14. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-methyl acrylate copolymer resins. 177.1340... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used as articles or components of...

  15. Preparations and applications in UV curing coatings of epoxy acrylates containing carboxyl

    International Nuclear Information System (INIS)

    Wu Yu Min

    1999-01-01

    This paper introduces preparations of epoxy acrylates containing carboxyl through the reactions of epoxy acrylates with butanedioic anhydride, pentanedioic anhydride, cis-butenedioic anhydride, phthalic anhydride, tetrabromophthalic anhydride and -tetrahydrophthalic anhydride. These epoxy acrylates containing carboxyl have been applied to UV-curing coatings and their effects on properties of UV-curing coatings have been studied

  16. 40 CFR 180.1162 - Acrylate polymers and copolymers; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Acrylate polymers and copolymers... RESIDUES IN FOOD Exemptions From Tolerances § 180.1162 Acrylate polymers and copolymers; exemption from the requirement of a tolerance. (a) Acrylate polymers and copolymers are exempt from the requirement of a...

  17. Theory of edge radiation

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, G.; Kocharyan, V.; Saldin, E.; Schneidmiller, E.; Yurkov, M.

    2008-08-15

    We formulate a complete theory of Edge Radiation based on a novel method relying on Fourier Optics techniques. Similar types of radiation like Transition UndulatorRadiation are addressed in the framework of the same formalism. Special attention is payed in discussing the validity of approximations upon which the theory is built. Our study makes consistent use of both similarity techniques and comparisons with numerical results from simulation. We discuss both near and far zone. Physical understanding of many asymptotes is discussed. Based on the solution of the field equation with a tensor Green's function technique, we also discuss an analytical model to describe the presence of a vacuum chamber. In particular, explicit calculations for a circular vacuum chamber are reported. Finally, we consider the use of Edge Radiation as a tool for electron beam diagnostics. We discuss Coherent Edge Radiation, Extraction of Edge Radiation by a mirror, and other issues becoming important at high electron energy and long radiation wavelength. Based on this work we also study the impact of Edge Radiation on XFEL setups and we discuss recent results. (orig.)

  18. anomalous left anterior cerebral artery with hypoplastic right anterior ...

    African Journals Online (AJOL)

    2018-02-28

    Feb 28, 2018 ... We report an extremely rare anomalous variation of left anterior cerebral artery arising from the ... paraclinoid internal carotid artery and right ... Studies on the arteries of the brain: II-The anterior cerebral artery: Some anatomic ...

  19. (meth)acrylates on in situ visible light polymerization of ...

    Indian Academy of Sciences (India)

    60

    ... faster to be cured using a visible light source with a Tungsten-Halogen lamp ... ranging from 350 to 1100 nm, which even covers some UV and near IR region. .... incorporation of the acid-containing and/or acrylate-containing monomer led to.

  20. Microstructure and properties of styrene acrylate polymer cement concrete

    NARCIS (Netherlands)

    Undetermined, U.

    1995-01-01

    The paper systematically describes the evolution of the microstructure of a styrene acrylate polymer cement concrete in relation to its mechanical properties and durability. The results presented and discussed at the present paper involve the interaction of the polymer dispersion with portland

  1. Oil-Acrylic hybrid latexes as binders for waterborne coatings

    NARCIS (Netherlands)

    Hamersveld, E.M.S.; Es, van J.J.G.S.; German, A.L.; Cuperus, F.P.; Weissenborn, P.; Hellgren, A.C.

    1999-01-01

    The combination of the characteristics of oil, or alkyd, emulsions and acrylic latexes in a waterborne binder has been the object of various studies in the past. Strategies for combining the positive properties of alkyds, e.g. autoxidative curing, gloss and penetration in wood, with the fast drying

  2. Oil-acrylic hybrid latexes as binders for waterborne coatings

    NARCIS (Netherlands)

    Hamersveld, van E.M.S.; Es, van J.; German, A.L.; Cuperus, F.P.; Weissenborn, P.; Hellgren, A.C.

    1999-01-01

    The combination of the characteristics of oil, or alkyd, emulsions and acrylic latexes in a waterborne binder has been the object of various studies in the past. Strategies for combining the positive properties of alkyds, e.g. autoxidative curing, gloss and penetration in wood, with the fast drying

  3. Design and Synthesis of Novel Fluorine-containing Acrylates

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These new compounds exhibited some biological activity as preliminary bioassay indicated. A plausible reaction mechanism was outlined and discussed.

  4. Investigation into nanocellulosics versus acacia reinforced acrylic films

    Science.gov (United States)

    Yunqiao Pu; Jianguo Zhang; Thomas Elder; Yulin Deng; Paul Gatenholm; Arthur J. Ragauskas

    2007-01-01

    Three closely related cellulosic acrylic latex films were prepared employing acacia pulp fibers, cellulose whiskers and nonocellulose balls and their respective strength properties were determined. Cellulose whisker reinforced composites had enhanced strength properties compared to the acacia pulp and nanoball composites. AFM analysis indicated that the cellulose...

  5. Calibration of an Electron Linear Accelerator using an acrylic puppet

    International Nuclear Information System (INIS)

    Guzman C, C.S.; Picon C, C.

    1998-01-01

    The finality of this work is to find the dose for electron beams using acrylic puppets and inter comparing with the measurements in water, found also its respective conversion factor. With base in this, its may be realize interesting measurements for the good performance of a linear accelerator and special clinical treatments in less time. (Author)

  6. Decarboxylation-based traceless linking with aroyl acrylic acids

    DEFF Research Database (Denmark)

    Nielsen, John

    1998-01-01

    beta-Keto carboxylic acids are known to decarboxylate readily. In our pursuit to synthesize beta-indolinyl propiophenones, we have exploited this chemistry as a mean of establishing a traceless handle. 2-Aroyl acrylic acids have been esterified to a trityl resin, after which Michael-type addition...

  7. Continuous emulsion copolymerisation of styrene and methyl acrylate

    NARCIS (Netherlands)

    Boomen, van den F.H.A.M.; Meuldijk, J.; Thoenes, D.

    1996-01-01

    For emulsion polymerisation the reactor type has a strong influence on the final product properties, for example the particle size (distribution) and the polymer composition. A batch copolymerisation of styrene and methyl acrylate shows strong composition drift. The course of the batch reaction has

  8. Test of a large size acrylic scintillation counter

    International Nuclear Information System (INIS)

    Bertino, M.; De Zorzi, G.; Zanello, D.

    1984-01-01

    We have tested the behaviour of an acrylic scintillator measuring the attenuation length and the time resolution of a 7.8 m long counter. On a small sample the photon yield relative to the NE 110 plastic has been measured. (orig.)

  9. Hydrogen Bonding Interaction between 1-Propanol and Acrylic ...

    African Journals Online (AJOL)

    The association between 1-propanol and acrylic esters (methyl methacrylate, ethyl methacrylate and butyl methacrylate) in non-polar solvents, viz. n-heptane, CCl4, and benzene has been investigated by means of FTIR spectroscopy. The formation constants of the 1:1 complexes have been calculated using Nash's method.

  10. Atom transfer radical copolymerization of styrene and butyl acrylate

    NARCIS (Netherlands)

    Chambard, G.; Klumperman, B.; Matyjaszewski, K.

    2000-01-01

    Atom transfer radical polymerization of styrene and butyl acrylate has been investigated from a kinetic point of view. Attention is focused on the activation of the dormant species as well as on the termination that plays a role in these reactions. It has been shown that the activation of a styrene

  11. Acrylic Triblock Copolymers Incorporating Isosorbide for Pressure Sensitive Adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, James J.; Hillmyer, Marc A.; Reineke, Theresa M. (UMM)

    2016-05-10

    A new monomer acetylated acrylic isosorbide (AAI) was prepared in two steps using common reagents without the need for column chromatography. Free radical polymerization of AAI afforded poly(acetylated acrylic isosorbide) (PAAI), which exhibited a glass transition temperature (Tg) = 95 °C and good thermal stability (Td, 5% weight loss; N2 = 331 °C, air = 291 °C). A series of ABA triblock copolymers with either poly(n-butyl acrylate) (PnBA) or poly(2-ethylhexyl acrylate) (PEHA) as the low Tg midblocks and PAAI as the high Tg end blocks were prepared using Reversible Addition–Fragmentation chain Transfer (RAFT) polymerization. The triblock copolymers ranging from 8–24 wt % PAAI were evaluated as pressure sensitive adhesives by 180° peel, loop tack, and static shear testing. While the PAAI-PEHA-PAAI series exhibited poor adhesive qualities, the PAAI-PnBA-PAAI series of triblock copolymers demonstrated peel forces up to 2.9 N cm–1, tack forces up to 3.2 N cm–1, and no shear failure up to 10000 min. Dynamic mechanical analysis indicated that PAAI-PEHA-PAAI lacked the dissipative qualities needed to form an adhesive bond with the substrate, while the PAAI-PnBA-PAAI series exhibited a dynamic mechanical response consistent with related high performing PSAs.

  12. Comparison of classical dermatoscopy and acrylic globe magnifier dermatoscopy

    DEFF Research Database (Denmark)

    Lorentzen, Henrik F; Eefsen, Rikke Løvendahl; Weismann, Kaare

    2008-01-01

    Dermatoscopic asymmetry of melanocytic skin lesion is pivotal in most algorithms assessing the probability of melanoma. Larger lesions cannot be assessed by dermatoscopy and the Dermaphot in a single field of vision, but this can be performed using the acrylic globe magnifier. We examined the dia...

  13. Effect of acrylic acid on the properties of polyvinylpyrrolidone ...

    African Journals Online (AJOL)

    Hydrogels based on polyvinylpyrrolidone (PVP) networks grafted with acrylic acid (AAc) was prepared by using γ-rays from a Co-60 source at room temperature. The parameters like effect of radiation dose and concentration of AAc were studied. The properties such as gel content, swelling behavior and thermal stability ...

  14. High Speed Edge Detection

    Science.gov (United States)

    Prokop, Norman F (Inventor)

    2016-01-01

    Analog circuits for detecting edges in pixel arrays are disclosed. A comparator may be configured to receive an all pass signal and a low pass signal for a pixel intensity in an array of pixels. A latch may be configured to receive a counter signal and a latching signal from the comparator. The comparator may be configured to send the latching signal to the latch when the all pass signal is below the low pass signal minus an offset. The latch may be configured to hold a last negative edge location when the latching signal is received from the comparator.

  15. Radioinduced grafting of acrylic acid on expanded polystyrene matrices

    International Nuclear Information System (INIS)

    Postolache, C.; Simion, Corina; Dragomir, A.; Ponta, C.; Chirvasoiu, G.; Postolache, Carmen

    1998-01-01

    The unfixed surface radioactive contamination for low energy β radionuclides ( 3 H and 14 C) is determined by wiping the checked surfaces with sponge of absorbent materials. The activity built up by this sponge is measured by a liquid scintillator spectrometer. In this work, a method of obtaining sponges of expanded polystyrene with hydrophobic surface by radioinduced grafting of the acrylic acid is presented. These sponges have diameters of 28 mm, thicknesses of 1.5 - 2 mm and density of 22 mg/cm 3 . The samples were immersed in a grafting solution with the following composition: acrylic acid 30%, Cu SO 4 1%; water 69% which were deeply impregnated in repeated operations under vacuum and pressure conditions, respectively. Finally, the samples were exposed to γ radiation emitted by a 60 Co source (IETI 10 000 - IFIN-HH). The dose rates were 0.3, 0.5 and 1 Mrad/h. The range of the absorbed doses was 1 - 25 Mrad. The yields of radiochemical grafting have been determined by gravimetric, spectrophotometric and radiometric methods. The grafting agent used was 3 H labelled acrylic acid. The solvation capacity and the quenching characteristics of the grafted sponges in liquid scintillators, as well as the sampling yields have been analyzed as function of irradiation procedure and the percentage of grafted acrylic fragments. The superficial grafting of the acrylic acid has been carried out by the mentioned technique, leading to the increase of the wiping efficiency of the unfixed surface contaminating activity, without changes of polymer solubility in liquid scintillators and without the perturbation of the radioactivity detection process. (authors)

  16. Analysis and Testing of Bisphenol A-Free Bio-Based Tannin Epoxy-Acrylic Adhesives

    OpenAIRE

    Jahanshahi , Shayesteh; Pizzi , Antonio; Abdulkhani , Ali; Shakeri , Alireza

    2016-01-01

    International audience; A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET) and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, C-13-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 degrees C for 12 h. FT-MIR, C-13...

  17. Poly (ethylene oxide)-block-poly (n-butyl acrylate)-blockpoly (acrylic acid) triblock terpolymers with highly asymmetric hydrophilic blocks: synthesis and aqueous solution properties

    OpenAIRE

    Petrov, P. (Petar); Yoncheva, K. (Krassimira); Mokreva, P. (Pavlina); Konstantinov, S. (Spiro); Irache, J.M. (Juan Manuel); Müller, A.H.E. (Axel H.E.)

    2013-01-01

    The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)- block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO–PnBA–PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10–17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate ...

  18. Anionic polymerization of acrylates. XIV. Synthesis of MMA/acrylate block copolymers initiated with ester-enolate/tert-alkoxide complex

    Czech Academy of Sciences Publication Activity Database

    Vlček, Petr; Čadová, Eva; Kříž, Jaroslav; Látalová, Petra; Janata, Miroslav; Toman, Luděk; Masař, Bohumil

    2005-01-01

    Roč. 46, č. 14 (2005), s. 4991-5000 ISSN 0032-3861 Institutional research plan: CEZ:AV0Z4050913 Keywords : ligated anionic polymerization * (meth)acrylates * block copolymers Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.849, year: 2005

  19. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Ghim, Deoukchen; Kim, Jung Hyeun [University of Seoul, Seoul (Korea, Republic of)

    2016-02-15

    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T{sub g} of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  20. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    International Nuclear Information System (INIS)

    Ghim, Deoukchen; Kim, Jung Hyeun

    2016-01-01

    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T g of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  1. The Inner Urban Edge

    Science.gov (United States)

    Ferebee, Ann; Carpenter, Edward K.

    1974-01-01

    In this article, renewal of the inner urban edge is discussed. Norfolk (Virginia) is attempting to blur the difference between old and new neighbor hoods through zoning and architectural controls. Cincinnati (Ohio) is developing an environmentally sound hillside design. Reading (Pennsylvania) is utilizing old railyards for greenbelts of hiking and…

  2. Swords with Blunt Edges

    Science.gov (United States)

    Popham, W. James

    2004-01-01

    Many U.S. educators now wonder whether they're teachers or targets. This mentality stems from the specter of their school being sanctioned for failing the state accountability tests mandated under No Child Left Behind (NCLB). According to this author, most of those tests are like blunt-edged swords: They function badly in two directions. While…

  3. Center edge angle measurement for hip preservation surgery: technique and caveats.

    Science.gov (United States)

    Anderson, Lucas A; Gililland, Jeremy; Pelt, Christopher; Linford, Samuel; Stoddard, Gregory J; Peters, Christopher L

    2011-01-01

    Anterior and lateral center edge angles have traditionally been used to determine acetabular coverage, and thereby strongly influence the decision to perform acetabular reorientation versus osteochondroplasty in patients with dysplasia and/or femoroacetabular impingement. We propose templating the center of the contained articular femoral head in aspherical hips to provide reliable assessment of acetabular coverage. Digital radiographs of 30 patients with various combinations of femoral and acetabular morphologies were evaluated using 2 methods to identify the anterior center edge angle and lateral center edge angle. The control method used an estimated femoral head center for angle apex. The study technique determined the center of the femoral head by templating the congruent aspect of the femoral head contained by the acetabulum while ignoring the increasing lateral and anterior radius associated with cam deformities. Four readers measured lateral center edge angles on anteroposterior radiographs and anterior center edge angles on false-profile radiographs. Two reads were performed by each reader using both the estimated and the templated methods for a total of 4 reads. Interobserver reliability using the proposed method compared to the standard was much improved for anterior center edge angles (intraclass correlation coefficient of 0.76 vs 0.55) as well as with lateral center edge angles (ICC of 0.80 vs 0.42). Decreased correlation was most commonly associated with abnormal sourcil morphology, posterior wall deficiency combined with calcified labra, and os acetabuli. Including the anterolateral cam deformity in identifying the center of the femoral head for measuring center edge angles leads to an underestimation of acetabular coverage, which may negatively affect hip preservation surgical decision making. Copyright 2011, SLACK Incorporated.

  4. Recurrent uveitis and pigment dispersion in an eye with in-the-bag acrylic foldable intraocular lens.

    Science.gov (United States)

    Thakur, Monica; Bhatia, Prashant; Chandrasekhar, Garudadri; Senthil, Sirisha

    2016-02-26

    Phacoemulsification with in-the-bag intraocular lens (IOL) implantation is the standard procedure for cataract surgery. Pigment dispersion and uveitis can result when an IOL is placed in the sulcus. We report a case of a 64-year-old woman, with pigmentary glaucoma, who developed recurrent uveitis following uneventful cataract surgery and an in-the-bag hydrophobic acrylic IOL implant. Recurrent uveitis did not subside despite use of topical steroids over 3 months. Dilated examination revealed capsulophimosis with anterior dislocation of the IOL haptic. The mechanical trauma to the iris due to the displaced haptic was implicated as the cause of recurrent uveitis, which completely resolved after capsular excision and IOL repositioning. This case illustrates a rare cause of recurrent uveitis due to IOL haptic dislocation following severe capsulophimosis. 2016 BMJ Publishing Group Ltd.

  5. Assessment of a new hydrophilic acrylic supplementary IOL for sulcus fixation in pseudophakic cadaver eyes

    Science.gov (United States)

    Reiter, N; Werner, L; Guan, J; Li, J; Tsaousis, K T; Mamalis, N; Srinivasan, S

    2017-01-01

    Purpose Management of refractive errors after cataract surgery includes spectacles or contact lens, secondary laser vision correction, intraocular lens (IOL) exchange, or piggyback lens implantation. We evaluated for the first time a single-piece hydrophilic acrylic IOL designed for supplementary sulcus fixation in postmortem pseudophakic human eyes. Methods Pseudophakic human cadaver eyes were imaged by anterior segment optical coherence tomography (AS-OCT) to assess position of the primary IOL. Eyes were prepared as per the Miyake-Apple technique. The supplementary IOL (Medicontur A4 Addon IOL family) was then inserted into the ciliary sulcus. AS-OCT and photographs from anterior and posterior views were used to assess IOL centration, tilt, and interlenticular distance from the primary IOL. Results Data were obtained from 12 eyes having primary IOLs of varying materials and designs in the bag and representing different sizes of eyes and severity of Soemmering's ring formation. The A4 Addon IOL was successfully inserted into the ciliary sulcus and was well centered in all cases. Four cases of tilt were observed on AS-OCT: three with mild tilt due to pre-existing zonular dehiscence, and one due to a localized area of Soemmering's ring formation. Interlenticular distance ranged from 0.34 to 1.24 mm and was not dependent on severity of Soemmering's ring or type of primary IOL. Conclusions The A4 Addon IOL was designed for sulcus fixation as a supplementary lens, with a large diameter, a square-shaped optic, four smooth loop haptics, and a convex–concave optical surface. It exhibited appropriate centration and interlenticular distance with different primary in-the-bag IOLs. PMID:28106890

  6. Anterior cervical fusion: the role of anterior plating.

    Science.gov (United States)

    Daffner, Scott D; Wang, Jeffrey C

    2009-01-01

    Treatment of cervical pathology requires a clear understanding of the biomechanical benefits and limitations of cervical plates, their indications, and their associated complications. The use of anterior cervical plates has evolved significantly since their early application in cervical trauma. They have become widely used for anterior cervical decompression and fusion for cervical spondylosis. Plate design has undergone significant refinement and innovation, from the initial unlocked plates requiring bicortical purchase to the latest rotationally and translationally semiconstrained dynamic plates. Excellent clinical results have been reported for single-level anterior cervical decompression and fusion with or without plate fixation; however, the addition of an anterior cervical plate clearly leads to earlier fusion and better clinical results in longer fusions. Longer fusions should ideally consist of corpectomies and strut grafting because the decreased number of fusion surfaces tends to lead to higher fusion rates. Although anterior plate fixation leads to higher fusion rates in fusions of three or more levels, the associated pseudarthrosis rate is still high. The use of dynamic plates, through increased load sharing across the graft and decreased stress shielding, may improve fusion rates, particularly in long fusions. Nevertheless, adjuvant posterior fixation is recommended for fusions of more than three vertebral levels. Anterior plate fixation may be of particular benefit in the management of traumatic injuries, in revision settings, and in the treatment of smokers. Complications unique to plate fixation include hardware breakage and migration as well as ossification of the adjacent disk levels.

  7. Evaluation of edge enhancement effect of phase contrast imaging using newly-developed photostimulable phosphor plate

    International Nuclear Information System (INIS)

    Matsuo, Satoru; Morishita, Junji; Katafuchi, Tetsuro; Fujita, Hiroshi

    2012-01-01

    We investigated whether the use of a newly developed columnar-crystal-type photostimulable-phosphor plate (CP1M200, referred to as system C) helps to provide improved edge-enhanced effect in phase contrast imaging. Physical characteristics of 2 conventional particulate-crystal-type photostimulable-phosphor plates (RP-5PM, referred to as system A and RP-6M, referred to as system B) and system C were measured. Then, an acrylic plate phantom and RMI152 phantom were imaged using 3 types of plates, and the edge-enhancement effects were evaluated based on the profile curve of the acrylic plate phantom. Visual evaluation of the RMI152 phantom images was conducted. The results showed that the modulation transfer function (MTF) of system C was superior to those of the other systems. The WS of system C was superior to those of the other systems in the low frequency band region, and inferior to those of the other systems in the high frequency band region. The presence of an edge-enhanced image was not detectable in the profile curve of the acrylic plate in system A, although that was shown in systems B and C due to their excellent sharpness. In the visual image evaluation of the RMI152 phantom, image quality of system C was superior to those of the other systems. Phase contrast imaging with a digital detector of a columnar-crystal-type photostimulable-phosphor plate is considered to provide improved edge-enhancement over that of conventional plates. (author)

  8. Comparative Evaluation of Effect of Water Absorption on the Surface Properties of Heat Cure Acrylic: An in vitro Study

    OpenAIRE

    Chandu, G S; Asnani, Pooja; Gupta, Siddarth; Faisal Khan, Mohd.

    2015-01-01

    Background: Use of alkaline peroxide denture cleanser with different temperature of water could cause a change in surface hardness of the acrylic denture and also has a bleaching effect. The purpose of the study was to determine the effect of increased water content during thermal cycling of hot water-treated acrylic on the surface hardness of acrylic denture base when compared to warm water treated acrylic. And to compare the bleaching effect of alkaline peroxide solution on the acrylic dent...

  9. Anterior ankle arthroscopy, distraction or dorsiflexion?

    OpenAIRE

    de Leeuw, P.A.J.; Golanó, P.; Clavero, J.A.; van Dijk, C.N.

    2010-01-01

    Anterior ankle arthroscopy can basically be performed by two different methods; the dorsiflexion- or distraction method. The objective of this study was to determine the size of the anterior working area for both the dorsiflexion and distraction method. The anterior working area is anteriorly limited by the overlying anatomy which includes the neurovascular bundle. We hypothesize that in ankle dorsiflexion the anterior neurovascular bundle will move away anteriorly from the ankle joint, where...

  10. Microscopic analysis of an opacified OFT CRYL® hydrophilic acrylic intraocular lens

    Directory of Open Access Journals (Sweden)

    Bruna Vieira Ventura

    Full Text Available ABSTRACT A 51-year-old patient underwent posterior vitrectomy with perfluoropropane gas injection, phacoemulsification, and implantation of an Oft Cryl® hydrophilic acrylic intraocular lens (IOL because of traumatic retinal detachment and cataract in the right eye. On the first postoperative day, gas was filling the anterior chamber because of patient's non-compliance in terms of head positioning, and was reabsorbed within one week. Eight months later, the patient returned complaining of a significant decrease in vision. IOL opacification was noticed by slit-lamp examination. The lens was explanted to undergo gross and light microscopic analysis. The lens was also stained with the alizarin red method for calcium identification. Light microscopic analysis confirmed the presence of granular deposits, densely distributed in an overall circular pattern in the central part of the lens optic. The granules stained positive for calcium. This is the first case of the opacification of this type of hydrophilic lens. Surgeons should be aware of this potential postoperative complication, and the use of hydrophilic IOLs should be avoided in procedures involving intracameral gas because of the risk of IOL opacification.

  11. ICRF edge modeling

    International Nuclear Information System (INIS)

    1991-01-01

    This report describes the technical progress for the DOE sponsored grant, ''ICRF Edge Modeling.'' An emphasis is placed on the progress since the Technical Progress Report (January 10, 1990) was submitted to the Department of Energy. The design of ICRF antennas for C-Mod and TFTR was investigated during this period. In addition, quasilinear models for electron heating were refined and applied to the design of ICRF antennas. The relevant professional activities sponsored by this grant are given. 4 refs., 11 figs

  12. The use of acrylic resin oral prosthesis in radiation therapy of oral cavity and paranasal sinus cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, V.S.T.; Oral, K.; Aramamy, M.A.

    1982-07-01

    In radiation therapy of cancer of the oral cavity and the paranasal sinuses, the extent to which the tissues of the oral cavity are included in the radiation treatment portals will determine the severity of the oral discomfort during treatment. This will affect the nutritional status of the patients, and may eventually affect the total dose of radiation which the patients can receive for treatment of their cancers. In cooperation with the Maxillofacial Prosthetic Department, an acrylic resin oral prosthesis was developed. This prosthesis is easy to use and can be made for each individual patient within 24 hours. It allows for maximum sparing of the normal tissues in the oral cavity and can be modified for shielding of backscattered electrons from heavy metals in the teeth. We have also found that acrylic resin extensions can be built onto the posterior edge of post-maxillectomy obturators; this extension can be used as a carrier for radioactive sources to deliver radiation to deep seated tumor modules in the paranasal sinuses.

  13. The use of acrylic resin oral prosthesis in radiation therapy of oral cavity and paranasal sinus cancer

    International Nuclear Information System (INIS)

    Cheng, V.S.T.; Oral, K.; Aramamy, M.A.

    1982-01-01

    In radiation therapy of cancer of the oral cavity and the paranasal sinuses, the extent to which the tissues of the oral cavity are included in the radiation treatment portals will determine the severity of the oral discomfort during treatment. This will affect the nutritional status of the patients, and may eventually affect the total dose of radiation which the patients can receive for treatment of their cancers. In cooperation with the Maxillofacial Prosthetic Department, an acrylic resin oral prosthesis was developed. This prosthesis is easy to use and can be made for each individual patient within 24 hours. It allows for maximum sparing of the normal tissues in the oral cavity and can be modified for shielding of backscattered electrons from heavy metals in the teeth. We have also found that acrylic resin extensions can be built onto the posterior edge of post-maxillectomy obturators; this extension can be used as a carrier for radioactive sources to deliver radiation to deep seated tumor modules in the paranasal sinuses

  14. ICRF edge modeling studies

    Energy Technology Data Exchange (ETDEWEB)

    Lehrman, I.S. (Grumman Corp. Research Center, Princeton, NJ (USA)); Colestock, P.L. (Princeton Univ., NJ (USA). Plasma Physics Lab.)

    1990-04-01

    Theoretical models have been developed, and are currently being refined, to explain the edge plasma-antenna interaction that occurs during ICRF heating. The periodic structure of a Faraday shielded antenna is found to result in strong ponderomotive force in the vicinity of the antenna. A fluid model, which incorporates the ponderomotive force, shows an increase in transport to the Faraday shield. A kinetic model shows that the strong antenna near fields act to increase the energy of deuterons which strike the shield, thereby increasing the sputtering of shield material. Estimates of edge impurity harmonic heating show no significant heating for either in or out-of-phase antenna operation. Additionally, a particle model for electrons near the shield shows that heating results from the parallel electric field associated with the fast wave. A quasilinear model for edge electron heating is presented and compared to the particle calculations. The models' predictions are shown to be consistent with measurements of enhanced transport. (orig.).

  15. Anterior Knee Pain (Chondromalacia Patellae).

    Science.gov (United States)

    Garrick, James G.

    1989-01-01

    This article presents a pragmatic approach to the definition, diagnosis, and management of anterior knee pain. Symptoms and treatment are described. Emphasis is on active involvement of the patient in the rehabilitation exercise program. (IAH)

  16. Anterior approach for knee arthrography

    International Nuclear Information System (INIS)

    Zurlo, J.V.; Towers, J.D.; Golla, S.

    2001-01-01

    Objective. To develop a new method of magnetic resonance arthrography (MRA) of the knee using an anterior approach analogous to the portals used for knee arthroscopy.Design. An anterior approach to the knee joint was devised mimicking anterior portals used for knee arthroscopy. Seven patients scheduled for routine knee MRA were placed in a decubitus position and under fluoroscopic guidance a needle was advanced from a position adjacent to the patellar tendon into the knee joint. After confirmation of the needle tip location, a dilute gadolinium solution was injected.Results and conclusion. All the arthrograms were technically successful. The anterior approach to knee MRA has greater technical ease than the traditional approach with little patient discomfort. (orig.)

  17. Design considerations for the commercial production of wood acrylics

    International Nuclear Information System (INIS)

    Witt, A.E.; Bosco, L.R.

    1978-01-01

    The major application of wood acrylics is for flooring, more specifically in high traffic area. The most important property is its abrasion resistance. As for the decisions in facility design, the following considerations must be made: irradiation or heat-catalyst to polymerize, machine irradiation or isotope irradiation, and wet or dry irradiation. Then, processing considerations are made on wood type, monomer selection, dye selection, fire retardant, dose conditions and crosslinker usage. In ''PermaGrain'' production, for example, the facility has the yearly production capacity of over 4,000,000 kilograms of wood acrylic. The starting wood form is small slats or fingers. After pressure cycle, the impregnant wet wood is lowered into an irradiation pool and the product canister passes around a cobalt 60 source. After irradiation, the product is taken out of the pool and allowed to cool. Then, final sizing and finishing are carried out. (Mori, K.)

  18. Study on Tough Blends of Polylactide and Acrylic Impact Modifier

    Directory of Open Access Journals (Sweden)

    Xiaoli Song

    2014-02-01

    Full Text Available Acrylic impact modifiers (ACRs with different soft/hard monomer ratios (mass ratios were prepared by semi-continuous seed emulsion copolymerization using the soft monomer butyl acrylate and the hard monomer methyl methacrylate, which were used to toughen polylactide (PLA. The effect of soft/hard ACR monomer ratio on the mechanical properties of PLA/ACR blends was investigated. The results showed that the impact strength and the elongation at break of PLA/ACR blends increased with increasing soft/hard ACR monomer ratio, while the tensile and flexural strengths of PLA had little change. The impact strength of PLA/ACR blends could be increased about 4 times more than that of pure PLA when the soft/hard monomer ratio of ACR was 90/10, which was the optimal ratio for good mechanical properties of PLA. Additionally, the possible mechanism of ACR toughening in PLA was discussed through impact fracture phase morphology analysis.

  19. Stronger multilayer acrylic dielectric elastomer actuators with silicone gel coatings

    Science.gov (United States)

    Lau, Gih-Keong; La, Thanh-Giang; Sheng-Wei Foong, Ervin; Shrestha, Milan

    2016-12-01

    Multilayer dielectric elastomer actuators (DEA) perform worst off than single-layer DEAs due to higher susceptibility to electro-thermal breakdown. This paper presents a hot-spot model to predict the electro-thermal breakdown field of DEAs and its dependence on thermal insulation. To inhibit the electrothermal breakdown, silicone gel coating was applied as barrier coating to multilayer acrylic DEA. The gel coating helps suppress the electro-thermally induced puncturing of DEA membrane at the hot spot. As a result, the gel-coated DEAs, in either a single layer or a multilayer stack, can produce 30% more isometric stress change as compared to those none-coated. These gel-coated acrylic DEAs show great potential to make stronger artificial muscles.

  20. Plant oil-based shape memory polymer using acrylic monolith

    Directory of Open Access Journals (Sweden)

    T. Tsujimoto

    2015-09-01

    Full Text Available This article deals with the synthesis of a plant oil-based material using acrylic monolith. An acrylic monolith bearing oxirane groups was prepared via simple technique that involved the dissolution of poly(glycidyl methacrylate-comethyl methacrylate (PGMA in ethanolic – aqueous solution by heating and subsequent cooling. The PGMA monolith had topologically porous structure, which was attributed to the phase separation of the polymer solution. The PGMA monolith was impregnated by epoxidized soybean oil (ESO containing thermally-latent catalyst, and the subsequent curing produced a crosslinked material with relatively good transparency. The Young’s modulus and the tensile strength of polyESO/PGMA increased compared with the ESO homopolymer. The strain at break of polyESO/PGMA was larger than that of the ESO homopolymer and crosslinked PGMA. Furthermore, polyESO/PGMA exhibited good shape memory-recovery behavior.

  1. Analysis of poly(styrene-co-methyl acrylate) and poly(styrene-co-butyl acrylate) by high-performance liquid chromatography

    NARCIS (Netherlands)

    Sparidans, R.W.; Claessens, H.A.; van Doremaele, G.H.J.; Herk, van A.M.

    1990-01-01

    Poly(styrene—co-methyl acrylate) and poly(styrene—co-butyl acrylate) were separated according to their chemical composition by gradient elution. The chromatographic separation on silica was optimized for a gradient ranging from n-heptane as a non-solvent to dichloromethane containing a small amount

  2. Placement of implant bridge anterior maxilla post autograft (Serial case

    Directory of Open Access Journals (Sweden)

    Rifaat Nurrahma

    2016-06-01

    Full Text Available An advanced technology with implants based has now been developed in recent years.Implant with the bridge superstructure method is employed after variety of considerations where it is expected to meet its function, aesthetics, and comfortability.The alveolar bone existed is one reason for the process of adding bone (bonegraft.This case report proposes to determine the successful insertion of a superstructure anterior implant bridge post autograft.Two female patients were asked to use dental implant anterior with bridge system.The first case, the autograft application is made for a 20-year-old woman with edentulous teeth 11, 21, 22. One year later it was then inserted in the area of dental implant fixture 11 and 22. After 9 months, the healing abutments and the superstructure were inserted too.2 weeks after, the abutments of bridge and crowns of teeth 11, 21 and 22 with a pontic in the teeth 21 had been inserted. The second case, a 46-year-old woman with edentulous 11,12,21,22.They want to change the denture because they did not feel comfortable with the removable denture acrylic.Fixture placement was done a year after autograft.Insertion of healing abutments and the superstructure printing can be done after 6 months.A month later implant abutments and crowns could be inserted.Labial fullness is corrected; an implant-retained in the region of 12 and 21, 12, and 22 used the pontic.Prosthodontic rehabilitation with a fixed denture using the implant bridge after autograft anterior maxilla is an alternative fixed denture placement with satisfactory results, aesthetic correction and comfortably.

  3. Smoothness in Binomial Edge Ideals

    Directory of Open Access Journals (Sweden)

    Hamid Damadi

    2016-06-01

    Full Text Available In this paper we study some geometric properties of the algebraic set associated to the binomial edge ideal of a graph. We study the singularity and smoothness of the algebraic set associated to the binomial edge ideal of a graph. Some of these algebraic sets are irreducible and some of them are reducible. If every irreducible component of the algebraic set is smooth we call the graph an edge smooth graph, otherwise it is called an edge singular graph. We show that complete graphs are edge smooth and introduce two conditions such that the graph G is edge singular if and only if it satisfies these conditions. Then, it is shown that cycles and most of trees are edge singular. In addition, it is proved that complete bipartite graphs are edge smooth.

  4. Development of Electrically Conductive Transparent Coatings for Acrylic Plastic

    Science.gov (United States)

    1952-12-01

    after drying, but increased to 4,000 megoihms/square after 16 hours. 4. Polyacrylic-polyamine Cop-lyrrvrs Aqueous solutions of polymethacrylic acid ...methacrylic acid -methyl methaerylate copolymer re•I. The composite material, i. e., the acrylic and applied coating, retains essentially all the original...ation in 5%, NaOH solution for 5 minutes, rinsed in distilled water, immersed with agitation in 1516 nitric acid for 3 minutes and finally rinsed well

  5. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    International Nuclear Information System (INIS)

    Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik; Ibrahim, Mohammad Izzat; Yunus, Nurulhuda Mohd

    2014-01-01

    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough

  6. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    International Nuclear Information System (INIS)

    Rida Tajau; Nurulhuda Mohd Yunus; Mohd Hilmi Mahmood; Mek Zah Salleh; Nik Ghazali Nik Salleh

    2013-01-01

    Full-text: The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidized palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) for example EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80 %) than the palm oil based compounds (up to 70 %), where the different is around 10-15 %. The hardness property from this two type coatings can reached until 50 % at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newton's (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photo initiator give higher adhesion property and their also showed a higher glossiness property on the glass substrate compared to the coatings containing irgacure-819 photo initiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough. (author)

  7. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    Energy Technology Data Exchange (ETDEWEB)

    Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik [Radiation Processing Technology Division, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang, Selangor (Malaysia); Ibrahim, Mohammad Izzat [Faculty of Science, University of Malaya (UM), 50603 Kuala Lumpur (Malaysia); Yunus, Nurulhuda Mohd [Faculty of Science and Technology, National University Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2014-02-12

    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.

  8. Determining color difference thresholds in denture base acrylic resin.

    Science.gov (United States)

    Ren, Jiabao; Lin, Hong; Huang, Qingmei; Zheng, Gang

    2015-11-01

    In restorative prostheses, color is important, but the choice of color difference formula used to quantify color change in acrylic resins is not straightforward. The purpose of this in vitro study was to choose a color difference formula that best represented differences between the calculated color and the observed imperceptible to unacceptable color and to determine the corresponding perceptibility and acceptability threshold of color stability for denture base acrylic resins. A total of 291 acrylic resin denture base plates were fabricated and subjected to radiation tests from zero to 42 hours in accordance with ISO 7491:2000. Color was measured with a portable spectrophotometer, and color differences were calculated with 3 International Commission on Illumination (CIE) formulas: CIELab, CMC(1:1), and CIEDE2000. Thirty-four observers with no deficiencies in color perception participated in psychophysical perceptibility and acceptability assessments under controlled conditions in vitro. These 2 types of assessments were regressed to each observer by each formula to generate receiver operator characteristic (ROC) curves. Areas under the curves (AUCs) were then calculated and analyzed to exclude observers with poor color discrimination. AUCs were subjected to 1-way ANOVA (α=.05) to deter the statistical significance of discriminability among the 3 formulas in terms of perceptibility and acceptability judgments. Student-Newman-Keuls tests (α=.05) were used for post hoc comparison. CMC(1:1) and CIEDE2000 formulas performed better for imperceptible to unacceptable color differences, with corresponding CMC(1:1) and CIEDE2000 values for perceptibility of 2.52 and 1.72, respectively, and acceptability thresholds of 6.21 and 4.08, respectively. Formulas CMC(1:1) and CIEDE2000 possess higher discriminability than that of CIELab in the assessment of perceptible color difference threshold of denture base acrylic resin. A statistically significant difference exists

  9. The evolution of palm oil acrylates within 20 years in Nuclear Malaysia

    International Nuclear Information System (INIS)

    Mek Zah Salleh; Rida Tajau; Nurul Huda Mudri

    2016-01-01

    Acrylated palm oil was synthesized from epoxidized palm oil (EPOP), in early 1989, through acrylation/methacrylation process at Radiation Technology Division laboratory. The acrylated products namely Epoxidized Palm Oil Acrylate/Methacrylate (EPOLA/ EPOMA), with the molecular weight around 2000-3000 g/mol, was found curable when subjected to UV or EB irradiations. Isocyanation of EPOLAs resulted in a resin called Palm Oil Based Urethane Acrylate (POBUA). POBUA possess certain advantages over EPOLA such as much higher molecular weight between 5000 to 20000 g/ mol, better curing speed, crosslinking density, higher abrasion resistance and also higher pendulum hardness. Hyper branched polyurethane acrylate (HBPUA) from palm oil oleic was synthesized by a three-step reaction in 2012. The reaction was confirmed by several analytical data; hydroxyl value (OHV), FTIR, GPC and NMR spectroscopy analyses. The thermal decomposition of HBPUA formulations shows good thermal stability up to 450 degree Celsius. (author)

  10. Waterborne hyperbranched alkyd-acrylic resin obtained by mini emulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Grupo de Investigacion en Materiales Polimericos (GIMAPOL), Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia); Lopez, Betty [Grupo de Investigacion en Ciencia de los Materiales, Universidad de Antioquia, Calle, Medellin (Colombia)

    2016-10-15

    Four waterborne hyper branched alkyd-acrylic resins (HBRAA) were synthesized by mini emulsion polymerization from a hyper branched alkyd resin (HBR), methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA), by using benzoyl peroxide (BPO) and ammonium persulfate (AP) as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The conversion percentage, glass transition temperature (T{sub g}), content of acrylic polymer (determined by soxhlet extraction) and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS) showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly mono modal. The film properties (gloss, flexibility, adhesion and drying time) of the HBRAA were good. (author)

  11. Analysis and Testing of Bisphenol A—Free Bio-Based Tannin Epoxy-Acrylic Adhesives

    Directory of Open Access Journals (Sweden)

    Shayesteh Jahanshahi

    2016-04-01

    Full Text Available A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, 13C-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 °C for 12 h. FT-MIR, 13C-NMR and MALDI-TOF analysis have confirmed that the resin has been prepared under these conditions. The joints bonded with this resin were tested for block shear strength. The results obtained indicated that the best strength performance was obtained by the bioepoxy-acrylate adhesive resin prepared at 95 °C for a 12-h reaction.

  12. Competing edge networks

    Science.gov (United States)

    Parsons, Mark; Grindrod, Peter

    2012-06-01

    We introduce a model for a pair of nonlinear evolving networks, defined over a common set of vertices, subject to edgewise competition. Each network may grow new edges spontaneously or through triad closure. Both networks inhibit the other's growth and encourage the other's demise. These nonlinear stochastic competition equations yield to a mean field analysis resulting in a nonlinear deterministic system. There may be multiple equilibria; and bifurcations of different types are shown to occur within a reduced parameter space. This situation models competitive communication networks such as BlackBerry Messenger displacing SMS; or instant messaging displacing emails.

  13. Anterior ankle arthroscopy, distraction or dorsiflexion?

    NARCIS (Netherlands)

    de Leeuw, P.A.J.; Golanó, P.; Clavero, J.A.; van Dijk, C.N.

    2010-01-01

    Anterior ankle arthroscopy can basically be performed by two different methods; the dorsiflexion- or distraction method. The objective of this study was to determine the size of the anterior working area for both the dorsiflexion and distraction method. The anterior working area is anteriorly

  14. Ultraviolet curing of acrylated liquid natural rubber for surface coating application

    OpenAIRE

    Kannikar Kwanming; Pairote Klinpituksa; Wae-asae Waehamad

    2009-01-01

    Ultraviolet curable acrylated liquid natural rubber was prepared by grafting of photosensitive molecule onto liquid natural rubber for surface coating application. The liquid natural rubber (LNR) was firstly obtained by degradation of natural rubber latex with hydrogen peroxide and cobalt acetylacetonate at 65oC for 72 hrs. The preparation of acrylated natural rubber was carried out by the reaction of acrylic acid and epoxidized liquid natural rubber (ELNR) prior obtained from LNR with formic...

  15. Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

    OpenAIRE

    Bojanić Vaso

    2010-01-01

    Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in c...

  16. The transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion

    OpenAIRE

    Rianti, Devi

    2006-01-01

    A laboratoric experimental study was conducted on the transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion. The aim of this study is to know the difference of acrylic resin transverse strengths caused by immersion time variations in a concentrate solution. The study was carried out on unpolished acrylic resin plates with 65 × 10 × 2,5 mm dimension; solution with 15% Coleus amboinicus, Lour extract, and 30, 60, 90 days immersion times to measure the tra...

  17. Degenerate band edge laser

    Science.gov (United States)

    Veysi, Mehdi; Othman, Mohamed A. K.; Figotin, Alexander; Capolino, Filippo

    2018-05-01

    We propose a class of lasers based on a fourth-order exceptional point of degeneracy (EPD) referred to as the degenerate band edge (DBE). EPDs have been found in parity-time-symmetric photonic structures that require loss and/or gain; here we show that the DBE is a different kind of EPD since it occurs in periodic structures that are lossless and gainless. Because of this property, a small level of gain is sufficient to induce single-frequency lasing based on a synchronous operation of four degenerate Floquet-Bloch eigenwaves. This lasing scheme constitutes a light-matter interaction mechanism that leads also to a unique scaling law of the laser threshold with the inverse of the fifth power of the laser-cavity length. The DBE laser has the lowest lasing threshold in comparison to a regular band edge laser and to a conventional laser in cavities with the same loaded quality (Q ) factor and length. In particular, even without mirror reflectors the DBE laser exhibits a lasing threshold which is an order of magnitude lower than that of a uniform cavity laser of the same length and with very high mirror reflectivity. Importantly, this novel DBE lasing regime enforces mode selectivity and coherent single-frequency operation even for pumping rates well beyond the lasing threshold, in contrast to the multifrequency nature of conventional uniform cavity lasers.

  18. Thermogravimetric analysis of the polymer acrylate-vinyl ether mixture cured by radiation

    International Nuclear Information System (INIS)

    Danu, Sugiarto

    1998-01-01

    An experiment on thermal stability of the polymer acrylate-vinyl ether mixture cured by radiation have been done using thermogravimetric analysis. Three kinds of acrylic oligomers i.e., epoxy acrylate, urethane acrylate, and polypropylene glycol diacrylate, and vinyl ether monomers i.e., triethylene glycol divinyl ether (DVE-3), 1,4-cyclohexane dimethanol divinyl ether (CHVE), and butanediol monovinyl ether (HBVE) were used in the experiment. Reaction was taken via radical and cationic polymerisation. In case of cationic polymerisation, diphenyliodonium hexafluorophosphate fotoinisiator was used in the formulation. Thermogravimetric analysis was conducted in a nitrogen atmosphere at a flow rate of 40 ml/minute with a constant heating rate 10 o C and evaluation range were done from 25 to 500 o C. The results of thermogravimetric analysis showed that acrylate and DVE-3 mixture produced the polymer films with higher thermal stability than the mixture of acrylate with CHVE or HBVE. The composition of acrylate-vinyl ether mixture and degree of unsaturation of vinyl ether monomers influenced the thermal stability of polymer. The mixture of epoxy acrylate-vinyl ether and polypropylene glycol diacrylate-vinyl ether have 1 initial decomposition temperature whereas the urethane acrylate-vinyl ether mixture has 2 initial decomposition temperatures. (authors)

  19. (Meth)Acrylate Occupational Contact Dermatitis in Nail Salon Workers: A Case Series.

    Science.gov (United States)

    DeKoven, Samuel; DeKoven, Joel; Holness, D Linn

    Recently, many cases of acrylate-associated allergic contact dermatitis have appeared among nail salon workers. Common acrylate-containing products in nail salons include traditional nail polish, ultraviolet-cured shellac nail polish, ultraviolet-cured gel nails, and press-on acrylic nails. Nail salon technicians seen in the occupational medicine clinic in 2015 and 2016 were identified, and their patch test results and clinical features were summarized. Patch testing was done with the Chemotechnique (Meth)Acrylate nail series, and either the North American Standard series or the North American Contact Dermatitis Group screening series. Six patients were identified, all women, ages 38 to 58. Common presentations included erythematous dermatitis of the dorsa of the hands, palms, and forearms and fissures on the fingertips. Less common sites of eruptions included the periorbital region, cheeks, posterior ears, neck, sacral area, lateral thighs, and dorsa of the feet. All patients reacted to hydroxyethyl methacrylate, and 5 patients reacted to ethyl acrylate. Each patient also reacted to (meth)acrylates that are not found on either standard series, including ethyleneglycol dimethacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxyethyl acrylate. The authors report 6 cases of allergic contact dermatitis to acrylates in nail technicians seen over the past year, representing a new trend in their clinic. These cases are reflective of a growing trend of nail technicians with allergic contact dermatitis associated with occupational (meth)acrylate exposure. Efforts to improve prevention are needed.

  20. Anterior ethmoid anatomy facilitates dacryocystorhinostomy.

    Science.gov (United States)

    Blaylock, W K; Moore, C A; Linberg, J V

    1990-12-01

    The ethmoid air cell labyrinth lies adjacent to the medial orbital wall, extending even beyond the sutures of the ethmoid bone. Its anatomic relationship to the lacrimal sac fossa is important in lacrimal surgery. We evaluated computed tomographic scans of 190 orbits with normal ethmoid anatomy to define the anatomic relationship of anterior ethmoid air cells to the lacrimal sac fossa. In 93% of the orbits, the cells extended anterior to the posterior lacrimal crest, with 40% entering the frontal process of the maxilla. This anatomic relationship may be used to facilitate the osteotomy during dacryocystorhinostomy. During a 10-year period (310 cases), one of us routinely entered the anterior ethmoid air cells to initiate the osteotomy during dacryocystorhinostomy. This technique has helped to avoid lacerations of the nasal mucosa.

  1. Cheating on the edge.

    Directory of Open Access Journals (Sweden)

    Lee Alan Dugatkin

    2008-07-01

    Full Text Available We present the results of an individual agent-based model of antibiotic resistance in bacteria. Our model examines antibiotic resistance when two strategies exist: "producers"--who secrete a substance that breaks down antibiotics--and nonproducers ("cheats" who do not secrete, or carry the machinery associated with secretion. The model allows for populations of up to 10,000, in which bacteria are affected by their nearest neighbors, and we assume cheaters die when there are no producers in their neighborhood. Each of 10,000 slots on our grid (a torus could be occupied by a producer or a nonproducer, or could (temporarily be unoccupied. The most surprising and dramatic result we uncovered is that when producers and nonproducers coexist at equilibrium, nonproducers are almost always found on the edges of clusters of producers.

  2. Challenges in edge modeling

    International Nuclear Information System (INIS)

    Schneider, R.

    2007-01-01

    Fluid models like B2, UEDGE or EDGE2D are the working horses for scrape-off layer physics, both for design and experimental support. The concept of a numerical tokamak, aiming at a predictive code for ITER, triggers the need to re-assess the available tools and their necessary extensions. These additional physics issues will be summarized from a personal point-of-view. Depending on the specific problem, several complexity levels of scrape-off layer models will be needed. Therefore, a hierarchy of tools is necessary, which will be discussed. Furthermore, the experience existing in other scientific fields with multi-scale problems and modeling should be used. Here, the coupling of different length and time scales are in particular of interest for fusion problems. (author)

  3. Edge remap for solids

    Energy Technology Data Exchange (ETDEWEB)

    Kamm, James R.; Love, Edward; Robinson, Allen C; Young, Joseph G.; Ridzal, Denis

    2013-12-01

    We review the edge element formulation for describing the kinematics of hyperelastic solids. This approach is used to frame the problem of remapping the inverse deformation gradient for Arbitrary Lagrangian-Eulerian (ALE) simulations of solid dynamics. For hyperelastic materials, the stress state is completely determined by the deformation gradient, so remapping this quantity effectively updates the stress state of the material. A method, inspired by the constrained transport remap in electromagnetics, is reviewed, according to which the zero-curl constraint on the inverse deformation gradient is implicitly satisfied. Open issues related to the accuracy of this approach are identified. An optimization-based approach is implemented to enforce positivity of the determinant of the deformation gradient. The efficacy of this approach is illustrated with numerical examples.

  4. Playing on the edge

    DEFF Research Database (Denmark)

    Cermak-Sassenrath, Daniel

    2018-01-01

    and specific ways. For instance, gambling for money, party and drinking games, professional play and show sports, art installations, violent and military propaganda computer games, pervasive/mobile gaming, live-action role playing, festivals, performances, and games such as Ghosting and Planking. It is argued......Everything gets more interesting, challenging, or intense the closer it gets to the edge, and so does play. How edgy can play become and still be play? Based on Huizinga’s notion of play, this chapter discusses how a wide range of playful activities pushes the boundaries of play in different...... that in concert with a number of characteristics that mark an activity as play, play is essentially a subjective perspective and individual decision of the player. Huizinga calls this attitude the play spirit, which informs a player’s actions and is in turn sustained by them. Edgy digital or mobile games do...

  5. Competing edge networks

    International Nuclear Information System (INIS)

    Parsons, Mark; Grindrod, Peter

    2012-01-01

    We introduce a model for a pair of nonlinear evolving networks, defined over a common set of vertices, subject to edgewise competition. Each network may grow new edges spontaneously or through triad closure. Both networks inhibit the other's growth and encourage the other's demise. These nonlinear stochastic competition equations yield to a mean field analysis resulting in a nonlinear deterministic system. There may be multiple equilibria; and bifurcations of different types are shown to occur within a reduced parameter space. This situation models competitive communication networks such as BlackBerry Messenger displacing SMS; or instant messaging displacing emails. -- Highlights: ► A model for edgewise-competing evolving network pairs is introduced. ► Defined competition equations yield to a mean field analysis. ► Multiple equilibrium states and different bifurcation types can occur. ► The system is sensitive to sparse initial conditions and near unstable equilibriums.

  6. Mechanisms of Probe Tack Adhesion of Model Acrylic Elastomers

    Science.gov (United States)

    Lakrout, Hamed; Creton, Costantino; Ahn, Dongchan; Shull, Kenneth R.

    1997-03-01

    The adhesion mechanisms of model acrylate homopolymers and copolymers are studied with an instrumented probe tack test. A video camera positioned under the transparent glass substrate records the bonding and debonding process while the force displacement curve is acquired. This setup allows to couple the observation of the cavitation and fibrillation mechanisms, occurring during the debonding of the film from the stainless steel probe, with the mechanical measurement of stress and strain. The transitions between different debonding mechanisms are critically dicussed in terms of the bulk and surface properties of the adhesive and its molecular structure.

  7. 133Xe labelling of acrylate for catheter embolisation

    International Nuclear Information System (INIS)

    Endert, G.; Penzel, E.; Ritter, H.; Schumann, E.

    1983-01-01

    A method for radio-nucleide labelling of histo-acryl/lipiodol with 133 Xe gas is described. The method consists of disolving the gas in lipiodol under sterile conditions. After embolisation and angiography, the localisation of the embolising material can be determined by means of a scintillation camera. The labelling method was used in 15 patients. In all patients the position of the embolising material, as demonstrated by scintigraphy, corresponded with the radiological findings. It was not possible to demonstrate escape of the material by scintigraphy. (orig.) [de

  8. Electron beam curing polyurethane acrylate oligomer in air

    International Nuclear Information System (INIS)

    Zhu, Zhenkang; Chen, Xing; Zhou, Jichun; Ma, Zue-Teh

    1988-01-01

    It has been found according to our synthesis that a novel kind of polyurethane acrylate oligomer can be cured by electron beam in the presence of oxygen, even at normal atomospheric levels, without any additives. Irradiation of the oligomer with substantially complete cure to a solid non-tacky state is quite remarkable. It has the same gel content (90 %) in air as in nitrogen at dose of 33 kGy. Double bond conversion of the oligomer is about 50 % by I.R. (author)

  9. Electrode kinetics of ytterbium (III) in acrylate and crotonate media

    Energy Technology Data Exchange (ETDEWEB)

    Rao, A L.J.; Singh, M

    1982-07-01

    The polarographic reduction of Yb(III) in acrylate and crotonate media gives well-defined, diffusion-controlled irreversible waves. The forward rate constant (sub(f,h)Ksup(0)) and transfer coefficient (..cap alpha..) have been calculated by Koutecky's theoretical treatment as extended by Meites and Israel. This has also been made the basis of a method for the determination of Yb(III) in the presence of diverse ions and rare earth ions. Under optimum conditions. Yb(III) in the range 4 x 10/sup -4/ M to 1.6 x 10/sup -3/ M could be successfully determined in various mixtures, using any of the two acids.

  10. 78 FR 6213 - Styrene-2-Ethylhexyl Acrylate Copolymer; Tolerance Exemption

    Science.gov (United States)

    2013-01-30

    ...This regulation establishes an exemption from the requirement of a tolerance for residues of 2-propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene; also known as styrene-2-ethylhexyl acrylate copolymer when used as an inert ingredient in a pesticide chemical formulation. H. B. Fuller Company submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting an exemption from the requirement of a tolerance. This regulation eliminates the need to establish a maximum permissible level for residues of 2-propenoic acid, 2-Ethylhexyl Ester, Polymer with Ethenylbenzene on food or feed commodities.

  11. Unilateral anterior ischemic optic neuropathy

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Lund-Andersen, Henrik

    2013-01-01

    of this study was to investigate the ipRGC mediated pupil response in patients with a unilateral non-arteritic anterior ischemic optic neuropathy (NAION). Consensual pupil responses during and after exposure to continuous 20 s blue (470 nm) or red (660 nm) light of high intensity (300 cd/m(2)) were recorded...

  12. The transverse ligament as a landmark for tibial sagittal insertions of the anterior cruciate ligament: a cadaveric study.

    Science.gov (United States)

    Kongcharoensombat, Wirat; Ochi, Mitsuo; Abouheif, Mohamed; Adachi, Nobuo; Ohkawa, Shingo; Kamei, Goki; Okuhara, Atushi; Shibuya, Hoyatoshi; Niimoto, Takuya; Nakasa, Tomoyuki; Nakamae, Atsuo; Deie, Masataka

    2011-10-01

    The purpose of this study was to determine the relation between the position of the transverse ligament, the anterior edge of the anterior cruciate ligament (ACL) tibial footprint, and the center of the ACL tibial insertion. We used arthroscopy for localization of the anatomic landmarks, followed by insertions of guide pins under direct visualization, and then the position of these guide pins was checked on plain lateral radiographs. The transverse ligament and the anterior aspect of the ACL tibial footprint were identified by arthroscopy in 20 unpaired cadaveric knees (10 left and 10 right). Guide pins were inserted with tibial ACL adapter drill guides under direct observation at the transverse ligament, the anterior aspect of the tibial footprint, and the center of tibial insertion of the ACL. Then, plain lateral radiographs of specimens were taken. The Amis and Jakob line was used to define the attachment of the ACL tibial insertion and the transverse ligament. A sagittal percentage of the location of the insertion point was determined and calculated from the anterior margin of the tibia in the anteroposterior direction. The transverse ligament averaged 21.20% ± 4.1%, the anterior edge of the ACL tibial insertion averaged 21.60% ± 4.0%, and the center of the ACL tibial insertion averaged 40.30% ± 4.8%. There were similar percent variations between the transverse ligament and the anterior edge of the ACL tibial insertion, with no significant difference between them (P = .38). Intraobserver and interobserver reliability was high, with small standard errors of measurement. This study shows that the transverse ligament coincides with the anterior edge of the ACL tibial footprint in the sagittal plane. The transverse ligament can be considered as a new landmark for tibial tunnel positioning during anatomic ACL reconstruction. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  13. Válvula de uretra anterior Anterior urethral valves

    Directory of Open Access Journals (Sweden)

    Silvio Tucci Jr.

    2003-02-01

    Full Text Available Objetivo: apresentar os aspectos clínicos, diagnósticos e terapêuticos de pacientes portadores de válvula da uretra anterior. Descrição: em dois neonatos, o diagnóstico presuntivo de patologia obstrutiva do trato urinário foi sugerido pela ultra-sonografia realizada no período pré-natal, confirmando-se o diagnóstico de válvula de uretra anterior pela avaliação pós-natal. Os pacientes foram submetidos a tratamento cirúrgico paliativo, com vesicostomia temporária e, posteriormente, definitivo, pela fulguração endoscópica das válvulas. Ambos evoluíram com função renal normal. Comentários: a válvula da uretra anterior é anomalia rara que deve ser considerada em meninos com quadro radiológico pré-natal sugestivo de obstrução infravesical, secundariamente à hipótese mais comum de válvula da uretra posterior. Ressaltamos a utilização da vesicostomia como derivação urinária temporária nestes casos, prevenindo potenciais complicações pela manipulação da uretra do recém-nascido.Objective: to discuss clinical signs, diagnostic tools and therapeutics of anterior urethral valves, an obstructive anomaly of the urinary system in males. Description: signs of urinary tract obstruction were identified on pre-natal ultrasound in two male fetuses and the diagnosis of anterior urethral valves was made through post-natal evaluation. As an initial treatment, vesicostomy was performed in both patients. Later, the valves were fulgurated using an endoscopic procedure. During the follow-up period both patients presented normal renal function. Comments: anterior urethral valves are a rare form of urethral anomaly that must be ruled out in boys with pre-natal ultrasound indicating infravesical obstruction. Vesicostomy used as an initial treatment rather than transurethral fulguration may prevent potential complications that can occur due to the small size of the neonatal urethra.

  14. Cutting Edge Localisation in an Edge Profile Milling Head

    NARCIS (Netherlands)

    Fernandez Robles, Laura; Azzopardi, George; Alegre, Enrique; Petkov, Nicolai

    2015-01-01

    Wear evaluation of cutting tools is a key issue for prolonging their lifetime and ensuring high quality of products. In this paper, we present a method for the effective localisation of cutting edges of inserts in digital images of an edge profile milling head. We introduce a new image data set of

  15. Evaluation of potential substrates for restenosis and thrombosis in overlapped versus edge-to-edge juxtaposed bioabsorbable scaffolds: Insights from a computed fluid dynamic study.

    Science.gov (United States)

    Rigatelli, Gianluca; Zuin, Marco; Dell'Avvocata, Fabio; Cardaioli, Paolo; Vassiliev, Dobrin; Ferenc, Miroslaw; Nghia, Nguyen Tuan; Nguyen, Thach; Foin, Nicholas

    2018-04-01

    Multiple BRSs and specifically the Absorb scaffold (BVS) (Abbott Vascular, Santa Clara, CA USA) have been often used to treat long diffuse coronary artery lesions. We evaluate by a computational fluid dynamic(CFD) study the impact on the intravascular fluid rheology on multiple bioabsorbable scaffolds (BRS) by standard overlapping versus edge-to-edge technique. We simulated the treatment of a real long significant coronary lesion (>70% luminal narrowing) involving the left anterior descending artery (LAD) treated with a standard or edge-to-edge technique, respectively. Simulations were performed after BVS implantations in two different conditions: 1) Edge-to-edge technique, where the scaffolds are kissed but not overlapped resulting in a luminal encroachment of 0.015cm (150μm); 2) Standard overlapping, where the scaffolds are overlapped resulting in a luminal encroachment of 0.030cm (300μm). After positioning the BVS across the long lesion, the implantation procedure was performed in-silico following all the usual procedural steps. Analysis of the wall shear stress (WSS) suggested that at the vessel wall level the WSS were lower in the overlapping zones overlapping compared to the edge-to-edge zone (∆=0.061Pa, p=0.01). At the struts level the difference between the two WSS was more striking (∆=1.065e-004 p=0.01) favouring the edge-to-edge zone. Our study suggested that at both vessel wall and scaffold struts levels, there was lowering WSS when multiple BVS were implanted with the standard overlapping technique compared to the "edge-to-edge" technique. This lower WSS might represent a substrate for restenosis, early and late BVS thrombosis, potentially explaining at least in part the recent evidences of devices poor performance. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Formation of Methyl Acrylate from CO 2 and Ethylene via Methylation of Nickelalactones

    KAUST Repository

    Bruckmeier, Christian

    2010-05-24

    The nickel-induced coupling of ethylene and CO2 represents a promising pathway toward acrylates. To overcome the high bond dissociation energies of the M-O moieties, we worked out an in situ methylation of nickelalactones to realize the β-hydride elimination and the liberation of the acrylate species. © 2010 American Chemical Society.

  17. [Contact dermatitis caused by acrylates among 8 workers in an elevator factory].

    Science.gov (United States)

    Pérez-Formoso, J L; de Anca-Fernández, J; Maraví-Cecilia, R; Díaz-Torres, J M

    2010-05-01

    Acrylates are widely used low-molecular-weight substances, initially introduced in industry in the 1930s and subsequently applied also in medicine and the home. One of their main features is the ability to undergo polymerization. The most commonly used acrylic compounds are cyanoacrylates, methacrylates, and acrylates. To confirm suspicion of occupational disease in a group of workers in an elevator factory. We studied 8 patients with dermatitis of the hands and finger pads. In their work, the patients came into contact with acrylates. Patch testing was applied with an acrylate panel (BIAL-Aristegui, Bilbao, Spain). Seven of the patients (87. 5%) had a positive result with 1% ethylene glycol dimethacrylate. Positive were also observed for 2% hydroxyethyl methacrylate (5 patients, 62. 5%), 1% triethylene glycol dimethacrylate (4 patients, 50%), 10% ethyl methacrylate monomer (3 patients, 37. 5%), 10% methyl methacrylate monomer (2 patients, 25%), 1% ethyl acrylate (1 patient, 12. 5%), and 0. 1% acrylic acid (1 patient, 12. 5%). We highlight the strong sensitizing capacity of acrylates and the importance of taking all necessary preventive measures in industries where these substances are used. Such measures should include avoidance of contact with the product in cases where sensitization has been confirmed.

  18. Contact-killing of adhering streptococci by a quaternary ammonium compound incorporated in an acrylic resin

    NARCIS (Netherlands)

    Mei, Li; Ren, Yijin; Loontjens, Ton J. A.; van der Mei, Henny C.; Busscher, Henk J.

    2012-01-01

    Purpose: Acrylates for bonding of joint prostheses and stainless-steel brackets in orthopedics and orthodontics are prone to bacterial adhesion and biofilm formation, respectively, leading to serious infectious complications. Here we describe the preparation of a contact-killing acrylic resin by

  19. Enzyme-Catalyzed Synthesis of Saccharide Acrylate Monomers from Nonedible Biomass

    NARCIS (Netherlands)

    Kloosterman, Wouter M. J.; Brouwer, Sander; Loos, Katja

    Various cellulase preparations were found to catalyze the transglycosidation between cotton linters and 2-hydroxyethyl acrylate. The conversion and enzyme activity were found to be optimal in reaction mixtures that contained 5 vol% of the acrylate. The structures of the products were revealed by

  20. Synthesis of Radiation Curable Palm Oil-Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations.

    Science.gov (United States)

    Salih, Ashraf M; Ahmad, Mansor Bin; Ibrahim, Nor Azowa; Dahlan, Khairul Zaman Hj Mohd; Tajau, Rida; Mahmood, Mohd Hilmi; Yunus, Wan Md Zin Wan

    2015-08-04

    Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA) from an epoxidized palm oil product (EPOP) as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.

  1. Alkyd-acrylic hybrid systems for use as binders in waterborne paints

    NARCIS (Netherlands)

    Nabuurs, T.; Baijards, R.A.; German, A.L.

    1994-01-01

    Alkyd-acrylic hybrids were prepd. by polymg. the acrylic monomers in the presence of colloidal alkyd droplets. Polymn. in the presence of alkyd caused a retardation of the polymn. through radical delocalization following radical transfer to the unsatd. groups of the fatty acids in the alkyd. The

  2. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Science.gov (United States)

    2010-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate...

  3. Radiation-induced grafting of acrylic acid onto polyethylene filaments

    International Nuclear Information System (INIS)

    Kaji, K.; Sakurada, I.; Okada, T.

    1981-01-01

    Radiation-induced grafting of acrylic acid onto high density polyethylene (PE) filaments was carried out in order to raise softening temperature and impart flame retardance and hydrophilic properties. Mutual γ-irradiation method was employed for the grafting in a mixture of acrylic acid (AA), ethylene dichloride and water containing a small amount of ferrous ammonium sulfate. The rate of grafting was very low at room temperature. On the other hand, large percent grafts were obtained when the grafting was performed at an elevated temperature. Activation energy for the initial rate of grafting was found to be 17 kcal/mol between 20 and 60 0 C and 10 kcal/ mol between 60 and 80 0 C. Original PE filament begins to shrink at 70 0 C, shows maximum shrinkage of 50% at 130 0 C and then breaks off at 136 0 C. When a 34% AA graft is converted to metallic salt the graft filament retains its filament form even above 300 0 C and gives maximum shrinkage of 15%. Burning tests by a wire-netting basket method indicate that graft filaments and their metallic salts do not form melting drops upon burning and are self-extinguishing. Original PE filament shows no moisture absorption; however, that of AA-grafted PE increases with increasing graft percent. (author)

  4. Characteristics and mechanisms of acrylate polymer damage to maize seedlings.

    Science.gov (United States)

    Chen, Xian; Mao, Xiaoyun; Lu, Qin; Liao, Zongwen; He, Zhenli

    2016-07-01

    Superabsorbent acrylate polymers (SAPs) have been widely used to maintain soil moisture in agricultural management, but they may cause damage to plants, and the mechanisms are not well understood. In this study, seed germination, soil pot culture, hydroponic experiments, and SAPs degradation were conducted to investigate damage characteristics and mechanisms associated with SAPs application. The Results showed that SAPs inhibited maize growth and altered root morphology (irregular and loose arrangement of cells and breakage of cortex parenchyma), and the inhibitory effects were enhanced at higher SAPs rates. After 1h SAP hydrogels treatment, root malondialdehyde (MDA) content was significantly increased, while superoxide dismutase (SOD) and catalase (CAT) content were significantly decreased. Hydroponics experiment indicated that root and shoot growth was inhibited at 2.5mgL(-1) acrylic acid (AA), and the inhibition was enhanced with increasing AA rates. This effect was exacerbated by the presence of Na(+) at a high concentration in the hydrogels. Release and degradation of AA were enhanced at higher soil moisture levels. A complete degradation of AA occurred between 15 and 20 days after incubation (DAI), but it took longer for Na(+) concentration to decrease to a safe level. These results indicate that high concentration of both AA and Na(+) present in the SAPs inhibits plant growth. The finding of this study may provide a guideline for appropriate application of SAPs in agriculture. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Radiation processing of carbon fiber-acrylated epoxy composites

    International Nuclear Information System (INIS)

    Singh, A.; Saunders, C.B.

    1992-01-01

    Advanced composites, specifically carbon fiber reinforced epoxies, are being used for a variety of demanding structural applications, primarily because of their high strength-to-weight and stiffness-to-weight ratios, corrosion resistance, and damage tolerance characteristics. For these composites the key advantages of using electron beam (EB), rather than thermal curing, are curing at ambient temperature, reduced curing times for individual components, improved resin stability, fewer volatiles, and better control of the profile of energy absorption. Epoxy compounds do, however, have to be modified to make them EB curable. The electron beam penetration limit, a function of beam energy, product density, and the thickness of any container required, must also be examined when considering EB processing. Research is being conducted to develop EB-curable carbon fiber-acrylated epoxy composites. The tensile properties of these laminates are comparable to those of thermally cured epoxy laminates. Research is continuing to develop suitable resin formulations and coupling agents to optimize the mechanical properties of EB-cured carbon fiber laminates. In this chapter the EB curing of epoxies, processing considerations, and typical properties of EB-cured carbon fiber-acrylated epoxy laminates are discussed. (orig.)

  6. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    OpenAIRE

    Jamil, Siti Nurul Ain Md; Daik, Rusli; Ahmad, Ishak

    2014-01-01

    A synthesis of acrylonitrile (AN)/butyl acrylate (BA)/fumaronitrile (FN) and AN/EHA (ethyl hexyl acrylate)/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg) and stabilization temperature was studied using Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermog...

  7. Long-Chain Diacrylate Crosslinkers and Use of PEG Crosslinks in Poly(potassium acrylate-acrylic acid)/Kaolin Composite Superabsorbents

    OpenAIRE

    Koroush Kabiri; Siavash Nafisi; Mohammad jalaledin Zohuriaan-Mehr; Ali Akbar Yousefi

    2013-01-01

    Long-chain diacrylate crosslinkers based on linear α,ω-diols were synthesized and characterized using FTIR and 1H NMR spectroscopy. The highest reaction yield (99.5%) was due to polyethylene glycol diacrylate 1000 (PEGDA-1000). Then, kaolin-containing poly(potassium acrylate-acrylic acid) superabsorbent composites and kaolin-free counterparts were synthesized using PEGDA-1000.The effect of the crosslinker concentration on swelling, rheological and thermo-mechanical properties was investigated...

  8. Development of radiation curable surface coating based on soybean oil. part I. preparation and characterization of acrylated oil

    International Nuclear Information System (INIS)

    Ibrahim, M.S.; Said, H.M.; Moussa, I.M.

    2005-01-01

    An epoxy acrylate was synthesized from epoxidized soybean oil (ESOL) by using acrylic acid monomer. Triethyl amine (TEA) and hydroquinone were used as catalyst and inhibitor respectively. The epoxidized soybean oil acrylate (ESOLA) is done by introducing acrylic acid into oxirane groups of the epoxidized oil (ESOL). This reaction was confirmed by analytical data in terms of oxirane oxygen content, acid value, viscosity and spectroscopically analysis

  9. UV-crosslinkable photoreactive self-adhesive hydrogels based on acrylics

    Directory of Open Access Journals (Sweden)

    Czech Zbigniew

    2016-06-01

    Full Text Available Hydrogels are a unique class of macromolecular networks that can hold a large fraction of an aqueous solvent within their structure. They are suitable for biomedical area including controlled drug delivery and for technical applications as self-adhesive materials for bonding of wet surfaces. This paper describes photoreactive self-adhesive hydrogels based on acrylics crosslinked using UV radiation. They are prepared in ethyl acetate through radical polymerization of monomers mixture containing 2-ethylhexyl acrylate (2-EHA, butyl acrylate (BA, acrylic acid (AA and copolymerizable photoinitiator 4-acryloyloxy benzophenone (ABP at presence of radical starter 2.2’-azobis-diisobutyronitrile AIBN. The synthesized acrylic copolymers were determined by viscosity and GPC analysis and later modified using ethoxylated amines. 4-acryloyloxy benzophenone (ABP was used as crosslinking monomer. After UV crosslinking the properties of these novel synthesized hydrogels, such as tack, peel adhesion, shears strength, elongation and water adsorption were also studied.

  10. The transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion

    Directory of Open Access Journals (Sweden)

    Devi Rianti

    2006-12-01

    Full Text Available A laboratoric experimental study was conducted on the transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion. The aim of this study is to know the difference of acrylic resin transverse strengths caused by immersion time variations in a concentrate solution. The study was carried out on unpolished acrylic resin plates with 65 × 10 × 2,5 mm dimension; solution with 15% Coleus amboinicus, Lour extract, and 30, 60, 90 days immersion times to measure the transverse strength and sterilized aquadest was used as control. Acrylic resin plates transverse strength was measured using Autograph AG-10 TE. The data was analyzed using One-Way Anova and LSD with 5% degree of significance. The result showed that longer immersion time will decrease the transverse strength of the acrylic resin plates. After 90 days immersion time, the transverse strength decrease is still above the recommended standard transverse strength.

  11. Effect of the Mitral Valve's Anterior Leaflet on Axisymmetry of Transmitral Vortex Ring.

    Science.gov (United States)

    Falahatpisheh, Ahmad; Pahlevan, Niema M; Kheradvar, Arash

    2015-10-01

    The shape and formation of transmitral vortex ring are shown to be associated with diastolic function of the left ventricle (LV). Transmitral vortex ring is a flow feature that is observed to be non-axisymmetric in a healthy heart and its inherent asymmetry in the LV assists in efficient ejection of the blood during systole. This study is a first step towards understanding the effects of the mitral valve's anterior leaflet on transmitral flow. We experimentally study a single-leaflet model of the mitral valve to investigate the effect of the anterior leaflet on the axisymmetry of the generated vortex ring based on the three-dimensional data acquired using defocusing digital particle image velocimetry. Vortex rings form downstream of a D-shaped orifice in presence or absence of the anterior leaflet in various physiological stroke ratios. The results of the statistical analysis indicate that the formed vortex ring downstream of a D-shaped orifice is markedly non-axisymmetric, and presence of the anterior leaflet improves the ring's axisymmetry. This study suggests that the improvement of axisymmetry in presence of the anterior leaflet might be due to coupled dynamic interaction between rolling-up of the shear layer at the edges of the D-shaped orifice and the borders of the anterior leaflet. This interaction can reduce the non-uniformity in vorticity generation, which results in more axisymmetric behavior compared to the D-shaped orifice without the anterior leaflet.

  12. Edge instabilities of topological superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Johannes S. [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg (Germany); Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Assaad, Fakher F. [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg (Germany); Schnyder, Andreas P. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

    2016-07-01

    Nodal topological superconductors display zero-energy Majorana flat bands at generic edges. The flatness of these edge bands, which is protected by time-reversal and translation symmetry, gives rise to an extensive ground state degeneracy and a diverging density of states. Therefore, even arbitrarily weak interactions lead to an instability of the flat-band edge states towards time-reversal and translation-symmetry broken phases, which lift the ground-state degeneracy. Here, we employ Monte Carlo simulations combined with mean-field considerations to examine the instabilities of the flat-band edge states of d{sub xy}-wave superconductors. We find that attractive interactions induce a complex s-wave pairing instability together with a density wave instability. Repulsive interactions, on the other hand, lead to ferromagnetism mixed with spin-triplet pairing at the edge. We discuss the implications of our findings for experiments on cuprate high-temperature superconductors.

  13. Synthesis of Highly Porous Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) Asymmetric Membranes

    KAUST Repository

    Xie, Yihui; Moreno Chaparro, Nicolas; Calo, Victor M.; Cheng, Hong; Hong, Pei-Ying; Sougrat, Rachid; Behzad, Ali Reza; Tayouo Djinsu, Russell; Nunes, Suzana Pereira

    2016-01-01

    For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymers membranes used in this method, which were mainly based on polystyrene blocks. Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) (PtBA30k-b-PSU14k-b-PtBA30k) with a low polydispersity of 1.4 was synthesized by combining step-growth condensation and RAFT polymerization. Various advanced electron microscopies revealed that PtBA30k-b-PSU14k-b-PtBA30k assembles into worm-like cylindrical micelles in DMAc and adopts a “flower-like” arrangement with the PSU central block forming the shell. Computational modeling described the mechanism of micelle formation and morphological transition. Asymmetric nanostructured membranes were obtained with a highly porous interconnected skin layer and a sublayer with finger-like macrovoids. Ultrafiltration tests confirmed a water permeance of 555 L m-2 h-1 bar-1 with molecular weight cut-off of 28 kg/mol. PtBA segments on the membrane surface were then hydrolyzed and complexed with metals, leading to cross-linking and enhancement of antibacterial capability.

  14. Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

    Directory of Open Access Journals (Sweden)

    Keslarek Amauri José

    2004-01-01

    Full Text Available Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM. Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the particles, while S is uniformly distributed within then. The Na and N elemental maps show that the respective monovalent ions (Na+ and NH4+ have different distributions, in the latex: Na signal within the particles is stronger than in the background, while N is accumulated at the particle borders. The distributions of surfactant and counter-ions are thus different from some current assumptions, but they support recent results on the distribution of ionic constituents in latex films, by scanning electric potential microscopy.

  15. Synthesis of Highly Porous Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) Asymmetric Membranes

    KAUST Repository

    Xie, Yihui

    2016-03-24

    For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymers membranes used in this method, which were mainly based on polystyrene blocks. Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) (PtBA30k-b-PSU14k-b-PtBA30k) with a low polydispersity of 1.4 was synthesized by combining step-growth condensation and RAFT polymerization. Various advanced electron microscopies revealed that PtBA30k-b-PSU14k-b-PtBA30k assembles into worm-like cylindrical micelles in DMAc and adopts a “flower-like” arrangement with the PSU central block forming the shell. Computational modeling described the mechanism of micelle formation and morphological transition. Asymmetric nanostructured membranes were obtained with a highly porous interconnected skin layer and a sublayer with finger-like macrovoids. Ultrafiltration tests confirmed a water permeance of 555 L m-2 h-1 bar-1 with molecular weight cut-off of 28 kg/mol. PtBA segments on the membrane surface were then hydrolyzed and complexed with metals, leading to cross-linking and enhancement of antibacterial capability.

  16. Epidermoid cyst in Anterior, Middle

    Directory of Open Access Journals (Sweden)

    Kankane Vivek Kumar

    2016-09-01

    Full Text Available Epidermoid cysts are benign slow growing more often extra-axial tumors that insinuate between brain structures, we present the clinical, imaging, and pathological findings in 35 years old female patients with atypical epidermoid cysts which was situated anterior, middle & posterior cranial fossa. NCCT head revealed hypodense lesion over right temporal and perisylvian region with extension in prepontine cistern with mass effect & midline shift and MRI findings revealed a non-enhancing heterogeneous signal intensity cystic lesion in right frontal & temporal region extending into prepontine cistern with restricted diffusion. Patient was detoriated in night of same day of admission, emergency Fronto-temporal craniotomy with anterior peterousectomy and subtotal resection was done. The histological examination confirms the epidermoid cyst. The timing of ectodermal tissue sequestration during fetal development may account for the occurrence of atypical epidermoid cysts.

  17. Anterior ankle arthroscopy, distraction or dorsiflexion?

    Science.gov (United States)

    de Leeuw, Peter A J; Golanó, Pau; Clavero, Joan A; van Dijk, C Niek

    2010-05-01

    Anterior ankle arthroscopy can basically be performed by two different methods; the dorsiflexion- or distraction method. The objective of this study was to determine the size of the anterior working area for both the dorsiflexion and distraction method. The anterior working area is anteriorly limited by the overlying anatomy which includes the neurovascular bundle. We hypothesize that in ankle dorsiflexion the anterior neurovascular bundle will move away anteriorly from the ankle joint, whereas in ankle distraction the anterior neurovascular bundle is pulled tight towards the joint, thereby decreasing the safe anterior working area. Six fresh frozen ankle specimens, amputated above the knee, were scanned with computed tomography. Prior to scanning the anterior tibial artery was injected with contrast fluid and subsequently each ankle was scanned both in ankle dorsiflexion and in distraction. A special device was developed to reproducibly obtain ankle dorsiflexion and distraction in the computed tomography scanner. The distance between the anterior border of the inferior tibial articular facet and the posterior border of the anterior tibial artery was measured. The median distance from the anterior border of the inferior tibial articular facet to the posterior border of the anterior tibial artery in ankle dorsiflexion and distraction was 0.9 cm (range 0.7-1.5) and 0.7 cm (range 0.5-0.8), respectively. The distance in ankle dorsiflexion significantly exceeded the distance in ankle distraction (P = 0.03). The current study shows a significantly increased distance between the anterior distal tibia and the overlying anterior neurovascular bundle with the ankle in a slightly dorsiflexed position as compared to the distracted ankle position. We thereby conclude that the distracted ankle position puts the neurovascular structures more at risk for iatrogenic damage when performing anterior ankle arthroscopy.

  18. Anterior spinal cord syndrome of unknown etiology

    OpenAIRE

    Klakeel, Merrine; Thompson, Justin; Srinivasan, Rajashree; McDonald, Frank

    2015-01-01

    A spinal cord injury encompasses a physical insult to the spinal cord. In the case of anterior spinal cord syndrome, the insult is a vascular lesion at the anterior spinal artery. We present the cases of two 13-year-old boys with anterior spinal cord syndrome, along with a review of the anatomy and vasculature of the spinal cord and an explanation of how a lesion in the cord corresponds to anterior spinal cord syndrome.

  19. Anterior fixation of the axis.

    Science.gov (United States)

    Traynelis, Vincent C; Fontes, Ricardo B V

    2010-09-01

    Although anterior fixation of the axis is not commonly performed, plate fixation of C2 is an important technique for treating select upper cervical traumatic injuries and is also useful in the surgical management of spondylosis. To report the technique and outcomes of C2 anterior plate fixation for a series of patients in which the majority presented with symptomatic degenerative spondylosis. Forty-six consecutive patients underwent single or multilevel fusions over a 7-year period; 30 of these had advanced degenerative disease manifested by myelopathy or deformity. Exposure was achieved with rostral extension of the standard anterior cervical exposure via careful soft tissue dissection, mobilization of the superior thyroid artery, and the use of a table-mounted retractor. It was not necessary to remove the submandibular gland, section the digastric muscle, or make additional skin incisions. Screws were placed an average of 4.6 mm (+/- 2.3 mm) from the inferior C2 endplate with a mean sagittal trajectory of 15.7 degrees (+/- 7.6 degrees). Short- and long-term procedure-related mortality was 4.4%, and perioperative morbidity was 8.9%. Patients remained intubated an average of 2.5 days following surgery. Dysphagia was initially reported by 15.2% of patients but resolved by the 8th postoperative week in all patients. Arthrodesis was achieved in all patients available for long-term follow-up. Multilevel fusions were not associated with longer hospitalization or morbidity. Anterior plate fixation of the axis for degenerative disease can be accomplished with acceptable morbidity employing an extension of the standard anterolateral route.

  20. "Meniscus Sign" to Identify the Lenticule Edge in Small-Incision Lenticule Extraction.

    Science.gov (United States)

    Titiyal, Jeewan S; Kaur, Manpreet; Brar, Anand S; Falera, Ruchita

    2018-06-01

    To describe our technique of lenticule edge identification in small-incision lenticule extraction using the "meniscus sign" to prevent lenticule misdissection. Femtosecond laser application for small-incision lenticule extraction was performed. A "double ring" was visible, signifying the edge of the cap cut (outer ring) and lenticule cut (inner ring). The anterior and posterior lamellar planes were delineated in 2 different directions. During creation of the posterior lamellar channel, the lenticule edge was slightly pushed away from the surgeon to create a gap between the inner ring (diameter of the lenticule cut) and the lenticule edge. The lenticule edge assumed a frilled wavy appearance, and the meniscus sign was observed as a gap between the lenticule edge and the inner ring. The meniscus-shaped gap served as a landmark to identify the lenticule edge, and the relationship between the frilled lenticule edge and surgical instruments further acted as a guide to identify the correct plane of dissection. This technique was successfully undertaken in 50 eyes of 25 patients. The meniscus sign was observed in all cases, and no case had cap lenticular adhesions. The meniscus sign helps to identify the lenticule edge and correct dissection planes and provides a visual landmark during the entire surgical procedure.

  1. 38 CFR 3.379 - Anterior poliomyelitis.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Anterior poliomyelitis. 3... Specific Diseases § 3.379 Anterior poliomyelitis. If the first manifestations of acute anterior poliomyelitis present themselves in a veteran within 35 days of termination of active military service, it is...

  2. Fenestration of the anterior cerebral artery

    International Nuclear Information System (INIS)

    Ito, J.; Washiyama, K.; Hong Kim, C.; Ibuchi, Y.

    1981-01-01

    Three cases of angiographically demonstrated fenestration of the anterior cerebral artery are reported. Fenestration occurred at the medial half of the horizontal segment of the anterior cerebral artery in all cases. Its embryology and clinical significance are briefly discussed, and the anatomical and radiological literature on fenestration of the anterior cerebral artery is reviewed. (orig.)

  3. Evaluation of local muscle soreness treatment with anterior bite splint made of soft putty impression material

    Directory of Open Access Journals (Sweden)

    Harry Laksono

    2013-03-01

    Full Text Available Background: Local muscle soreness is the most common temporomandibular disorders complaint of patients seeking treatment in the dental clinics. The emergency treatment that can be done in the clinics to manage this disorder is by making anterior bite splint. Anterior bite splint is usually made of acrylic, but currently there is a soft putty impression material that can also be used for making anterior bite splint. The effectiveness of soft putty anterior bite splint in local muscle soreness treatment still has not clear. Purpose: To determine the effectiveness of the soft putty impression material as a material used for making anterior bite splint in the treatment of local muscle soreness. Case: Six patients was reported five female patients aged 20-40 years old and one male patient aged 37 years old with local muscle soreness. Four female patients with a “click” sound on TMJ. Case management: Make differential diagnosis with screening history (anamnesis, clinical examination consists of extra oral examination such as muscle and temporomandibular joint palpation, measure the mandibular movement, end-feel, load test, intra oral examination and radiographic evaluation. Record the results and make the diagnosis. Make a soft putty anterior bite splint, adjusted and inserted in the maxillary anterior teeth. Record the results based on signs and symptoms. Conclusion: It can be concluded that anterior bite splint made of soft putty impression material is effective for treatment the local muscle soreness.Latar belakang: Salah satu tipe temporomandibular disorders yang paling sering dijumpai di klinik dokter gigi adalah local muscle soreness. Perawatan yang dapat dengan segera dilakukan di klinik untuk mengelola gangguan tersebut adalah dengan pembuatan anterior bite splint. Biasanya anterior bite splint terbuat dari akrilik, namun saat ini telah ada bahan cetak soft putty yang memungkinkan untuk dipakai sebagai bahan pembuatan anterior bite splint

  4. A simple method for quantitative evaluation of the missing area of the anterior glenoid in anterior instability of the glenohumeral joint

    Energy Technology Data Exchange (ETDEWEB)

    Barchilon, Vidal S. [Sapir Medical Center, Department of Orthopedic Surgery, Shoulder Service, Kfar-Saba (Israel); Kotz, Eugene [Sapir Medical Center, Department of Imaging, Kfar-Saba (Israel); Barchilon Ben-Av, Mercedes [Achva College of Education, Department of Mathematics, MP Shikmim (Israel); Glazer, Ernesto [Rabin Medical Center, Department of Imaging, Petah Tikva (Israel); Nyska, Meir [Sapir Medical Center, Department of Orthopedic Surgery, Kfar-Saba (Israel)

    2008-08-15

    The objective of this study was to describe and validate a simple method to quantitatively calculate the missing area of the anterior part of the glenoid in anterior glenohumeral instability. The calculations were developed from three-dimensional (3D)-reconstructed computerized tomography en face images of the glenoid with 'subtraction' of the humeral head in 13 consecutive cases with known anterior glenohumeral joint instability diagnosed by history and clinical examination. The inferior portion of the glenoid was approximated to a true circle whose center was determined by means of a femoral head gauge. The eroded anterior area was calculated as the ratio between the depth (a perpendicular line from the center of the circle to the eroded edge of the anterior glenoid) and the radius of the inferior glenoid circle. This data was then compared to the results obtained by two additional different methods: direct computerized measurements of the missing area and direct computerized measurement of the ratio between the radius and depth, on two dimensional computed tomography (CT) en face view reconstructions of the glenoid. We provide a function that correlates the ratio between depth and radius of the inferior glenoid circle and the area of the missing anterior glenoid. The results obtained by three different methods were comparable. Simple trigonometric calculations showed that a 5% area defect corresponds to 0.8 (12.5%) of the radius of the inferior glenoid, while a 20% area defect corresponds to 0.5 (50%) of the same radius. Using this simple method and the function provided, the eroded area of the anterior part of the glenoid in anterior glenohumeral instability can be calculated preoperatively using a 3D CT reconstruction of the glenoid with 'subtraction' of the humeral head, obviating the need for sophisticated software to obtain this critical information for preoperative decision making. (orig.)

  5. A prospective study of the short-term treatment effects of the acrylic-splint rapid maxillary expander combined with the lower Schwarz appliance.

    Science.gov (United States)

    Wendling, Lisa K; McNamara, James A; Franchi, Lorenzo; Baccetti, Tiziano

    2005-01-01

    This prospective clinical study evaluated the short-term treatment effects of acrylic-splint rapid maxillary expander in conjunction with lower Schwarz appliance (RME-Sz) therapy to the acrylic-splint rapid maxillary expansion alone (RME-only group). Pretreatment and posttreatment lateral cephalograms were analyzed for 25 RME patients and 19 RME-Sz patients. The average time between films ranged between nine and 12 months. Statistical comparisons of the treatment changes in the RME-only and RME-Sz groups were performed by means of independent sample t-tests (P < .05). The largest difference between the two groups was in lower anterior facial height (LAFH). The normally occurring increase in LAFH was not observed in the RME-only group during the treatment period, indicating that the acrylic-splint expander had a posterior "bite block effect" on the developing craniofacial complex. LAFH increased by 1.7 mm in the RME-Sz group, a value similar to that observed in untreated individuals. Slight forward displacement of the maxilla was observed when RME was used alone, and the sagittal position of the maxilla remained unchanged in the RME-Sz group. A significant amount of intrusion of the maxillary molars (-0.8 mm) was noted in the RME-only group, whereas the maxillary molars were prevented from erupting in the RME-Sz group. The lower dentition showed a significantly greater amount of extrusion in the RME-Sz group than in the RME-only group. Finally, the Sz appliance prevented the mesial movement of the lower molars during the treatment period.

  6. The edge of space time

    International Nuclear Information System (INIS)

    Hawking, S.

    1993-01-01

    What happened at the beginning of the expansion of the universe. Did space time have an edge at the Big Bang. The answer is that, if the boundary conditions of the universe are that it has no boundary, time ceases to be well-defined in the very early universe as the direction ''north'' ceases to be well defined at the North Pole of the Earth. The quantity that we measure as time has a beginning but that does not mean spacetime has an edge, just as the surface of the Earth does not have an edge at the North Pole. 8 figs

  7. Novel polymer coatings based on plasma polymerized 2-methoxyethyl acrylate

    DEFF Research Database (Denmark)

    Wu, Zhenning; Jiang, Juan; Benter, Maike

    2008-01-01

    plasma system[4]. The system named SoftPlasma™ is equipped with unique three-phase pulsed AC voltage. Low energy plasma polymerization has almost no thermal load for sensitive polymer materials[5]. Plasma polymerized coatings are highly cross-linked, pin-hole free and provide hydrophilic or hydrophobic...... properties[4-6]. We have exploited these possibilities and prepared plasma polymerized 2-methoxyethyl acrylate (PPMEA) coatings on various polymer substrates. The PPMEA coatings were optimized using various plasma polymerization conditions and characterized by X-ray photoelectron spectroscopy......, Fouriertransform infrared spectroscopy, Atomic force spectroscopy and Water contact-angle measurements. The microstructures ofPPMEA coatings with different thicknesses were also studied. For practical applications in mind, the coating stability was tested in different media (air, water, acetone, phosphate...

  8. Scintillation properties of acrylate based plastic scintillator by photoploymerization method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hwan [Dept. of Radiological Science, Cheongju University, Cheongju (Korea, Republic of); Lee, Joo Il [Dept. of of Radiology, Daegu Health College, Daegu (Korea, Republic of)

    2016-12-15

    In this study, we prepared and characterized a acrylate based UV-curable plastic scintillator. It was used co-polymers TMPTA, DHPA and Ultima GoldTM LLT organic scintillator. The emission spectrum of the plastic scintillator was located in the range of 380⁓520 nm, peaking at 423 nm. And the scintillator is more than 50% transparent in the range of 400⁓ 800 nm. The emission spectrum is well match to the quantum efficiency of photo-multiplier tube and the fast decay time of the scintillation is 12 ns, approximately. This scintillation material provides the possibility of combining 3D printing technology, and then the applications of the plastic scintillator may be expected in human dosimetry etc.

  9. Eco-friendly Crosslinking Agent for Acid Functional Acrylic Resin

    Directory of Open Access Journals (Sweden)

    Archana Shah

    2009-01-01

    Full Text Available Oil from J. multifida was extracted and it was first converted into N,N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA. HEJFA has been synthesized by reaction between Jatropha oil and diethanol amine in presence of zinc oxide as a catalyst. The reaction is relatively rapid and proceeded to high yield at 200±5 OC. The resulting HEJFA was used to formulate thermosetting coating compositions. Films were cured at ambient (air drying and elevated (stove drying temperatures using N, N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA as eco-friendly crosslinking agent for acrylic resin. The coating performance of the various compositions was tested by measurement of scratch hardness, impact strength and chemical resistance. The results show better performance of the HEJFA based compositions compared to butylated melamine formaldehyde (MF based compositions.

  10. Synthesis and characterization of acrylate copolymer containing fluorescein functional group

    Energy Technology Data Exchange (ETDEWEB)

    Hui, Guodong; Huang, Weiyun; Song, Yunzhao; Chen, Deben; Zhong, Anyong [Sichuan University, Chengdu (China)

    2013-08-15

    We report a novel method to fabricate fluorescent polymer (F-CPA) based on the esterification between acrylate copolymer (CPA) and fluorescein using N, N-dicyclohexylcarbodiimide (DCC)/4-dimethylaminopyridine (DMAP) as catalyst. The resulting copolymer was characterized by Fourier transform-infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), ultraviolet-visible spectroscopy (UV-Vis) and fluorescence spectroscopy. In addition, the influences of concentration, solvents, pH and metal cations (Cu{sup 2+}, Fe{sup 3+} and Zn{sup 2+}) on the fluorescent behaviors of F-CPA are discussed in detail. All those observations suggest that the synthesized F-CPA is an excellent luminescent macromolecular material with simple synthesis method and excellent solubility. Moreover, its sensitive fluorescence response behaviors to solvents, pH and metal cations make it to become a polymer-based probe.

  11. Synthesis and characterization of acrylate copolymer containing fluorescein functional group

    International Nuclear Information System (INIS)

    Hui, Guodong; Huang, Weiyun; Song, Yunzhao; Chen, Deben; Zhong, Anyong

    2013-01-01

    We report a novel method to fabricate fluorescent polymer (F-CPA) based on the esterification between acrylate copolymer (CPA) and fluorescein using N, N-dicyclohexylcarbodiimide (DCC)/4-dimethylaminopyridine (DMAP) as catalyst. The resulting copolymer was characterized by Fourier transform-infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), ultraviolet-visible spectroscopy (UV-Vis) and fluorescence spectroscopy. In addition, the influences of concentration, solvents, pH and metal cations (Cu"2"+, Fe"3"+ and Zn"2"+) on the fluorescent behaviors of F-CPA are discussed in detail. All those observations suggest that the synthesized F-CPA is an excellent luminescent macromolecular material with simple synthesis method and excellent solubility. Moreover, its sensitive fluorescence response behaviors to solvents, pH and metal cations make it to become a polymer-based probe

  12. Radiation curable coatings from palm oil acrylated polyester prepolymer

    International Nuclear Information System (INIS)

    Azam Ali, M.; Ooi, T.L.; Salmiah, A.; Ishiaku, U.S.; Mohd Ishak, Z.A.

    2002-01-01

    Radiation (ultra-violet, UV) curable coatings were prepared by using palm oil acrylated polyester prepolymer (PEPP-1) in combination with different reactive diluents in the presence of photoinitiator Irgacure 184 (Irg184). The effects of viscosity of coating materials, radiation dose and curing behavior were investigated. The UV cured polymeric films properties such as pendulum hardness, wettability (contact angle), gel ,content, swelling character, tensile strength, elongation at break, and deformation stability were then determined. The optimum formulations were also coated on wood substrates after which the gloss and hardness of the cured film on the wood substrate were measured. Some formulations showed promising coatings properties and has a good potential application for the wood coating industry. (Author)

  13. [Acrylic resin reinforcement with metallic and nonmetallic inserts].

    Science.gov (United States)

    Preoteasa, Elena; Murariu, Cătălina Măgureanu; Ionescu, Ecaterina; Preoteasa, Cristina Teodora

    2007-01-01

    In the current use of acrylic resin for removable dentures and orthodontic treatments we are frequently facing the fact of base fracture. The repairing of this, determine most of the time, discomfort of the patient, by excluding the prosthetic device, affecting the treatment, loosing patient's time, doctor's time, implying the dental laboratory and extra expenses. The causes of fractures are many, from clinical cases with some specific anatomic and functional particularities, or parafunctional, to the incorrect designing, manufacturing or wearing of the prosthetic part, being connected with the materials characteristics. The consequences and costs of these fractures are leading to unsatisfying results in some of the clinical cases, in presence of parafunctions like bruxism or clenching and specifically for the new types of prosthetic rehabilitation, on natural teeth or implants.

  14. Dental Acrylics - Potential Agent for a Myriad of Diseases

    Directory of Open Access Journals (Sweden)

    Shivangi Gajwani

    2007-01-01

    Full Text Available An allergic reaction also known as a hypersensitivity reaction is caused by the immune system in response to a foreign substance (or allergen. Allergenic chemicals can be found in many products used in the dental operatory. With repeated exposure, these chemicals can cause allergic reactions in dental professionals, resulting in local as well as systemic manifestations. According to various studies done, it became evident that the prevalence of acrylic allergy most commonly in the form of allergic contact dermatitis is affecting the dental personnel to a much greater degree than is believed. Awareness of this disease complex in the form of any new symptoms and potential exposure is paramount for dental personals.

  15. Water absorbency of chitosan grafted acrylic acid hydrogels

    Science.gov (United States)

    Astrini, N.; Anah, L.; Haryono, A.

    2017-07-01

    Acrylic acid (AA) monomer was directly grafted onto chitosan (CTS) using potassium persulfate (KPS) as an initiator and methylenebisacrylamide (MBA) as a crosslinking agent under an inert atmosphere. One factor affecting the swelling capacity of the obtained hydrogel, KPS concentration, were studied. The hydrogel products were characterized using Fourier Transform Infrared spectroscopy (FTIR) for chemical structure and scanning electron microscopy (SEM) for morphology. Swelling of the hydrogel samples in distilled water and saline solution ( 9% NaCl ) was examined. Swelling capacity of the CTS-g-PAA hydrogels in distilled water (88.53 g/g) was higher than in NaCl solution (29.94 g/g) The highest swelling capacity value was obtained when the grafted reaction was carried out using 2.5wt% initiator

  16. Crosslinkers of Different Types in Precipitation Polymerization of Acrylic Acid

    Directory of Open Access Journals (Sweden)

    H. Eshaghi

    2013-01-01

    Full Text Available Crosslinked poly(acrylic acids were prepared using two types of crosslinker by precipitation polymerization method in a binary organic solvent. N,N’-methylenebisacrylamide (MBA and polyethylene glycol dimethacrylate (PEGDMA-330 were used as low-molecular weight and long-chain crosslinkers, respectively. The effect of various types of crosslinkers on polymer characteristics (i.e., gel content, equilibrium swelling, glass transition temperature, and rheological properties was investigated. Maximum amount of viscosity was obtained by using long-chain crosslinker. The Flory-Rehner equation and rubber elasticity theory were used to discuss the network structure of polymer. It was observed that, the glass transition temperature (Tg of the synthesized polymer containing PEGDMA-330 is higher than that of polymer containing MBA. Apparent and rotational viscosity were used to determine the optimal crosslinker type. In addition, the consistencycoefficient (m and flow behavior index (n parameter of Ostwald equation were investigated as well.

  17. Reduction of airfoil trailing edge noise by trailing edge blowing

    International Nuclear Information System (INIS)

    Gerhard, T; Carolus, T; Erbslöh, S

    2014-01-01

    The paper deals with airfoil trailing edge noise and its reduction by trailing edge blowing. A Somers S834 airfoil section which originally was designed for small wind turbines is investigated. To mimic realistic Reynolds numbers the boundary layer is tripped on pressure and suction side. The chordwise position of the blowing slot is varied. The acoustic sources, i.e. the unsteady flow quantities in the turbulent boundary layer in the vicinity of the trailing edge, are quantified for the airfoil without and with trailing edge blowing by means of a large eddy simulation and complementary measurements. Eventually the far field airfoil noise is measured by a two-microphone filtering and correlation and a 40 microphone array technique. Both, LES-prediction and measurements showed that a suitable blowing jet on the airfoil suction side is able to reduce significantly the turbulence intensity and the induced surface pressure fluctuations in the trailing edge region. As a consequence, trailing edge noise associated with a spectral hump around 500 Hz could be reduced by 3 dB. For that a jet velocity of 50% of the free field velocity was sufficient. The most favourable slot position was at 90% chord length

  18. Preliminary observation about anterior capsular changes in different patients after cataract phacoemulsification

    Directory of Open Access Journals (Sweden)

    Min Wang

    2013-09-01

    Full Text Available AIM: To compare changes of anterior capsular opening size between complicated and simple cataract patients who underwent phacoemulsification and foldable IOL implantation.METHODS:Patients complicated with high myopia, primary angle-closure glaucoma(PACG, diabetic cataract and simple cataract(control groupwere selected, 25 case in each group. All patients accepted phacoemulsification by the doctor with operation experience of more than 5 000 cases, and the same 1-piece hydrophilic acrylic IOL was implanted without any complicated happened. The measured value about anterior capsular area by Image-pro plus 6.0 was greater than 23mm2. Every patient was checked regularly through dilated pupil, take photos by slit-lamp camera and area was measured after operation 1 week, 1 month, 3 and 6 months, then to record the biological changes about anterior capsular in 4 groups.RESULTS: The average anterior capsular area in 4 groups 1 week after operation had no difference(P>0.05; No difference was found between simple and complicated high myopia group 6 months after operation(P>0.05. Capsule contraction was observed in complicated POAG group 3 months after operation and in diabetes mellitus group 6 months postoperatively, the average anterior capsular area become smaller than 1 week postoperatively(PCONCLUSION: Cataract patients who complicated PACG or diabetes mellitus maybe the high-risk groups, capsule contraction will be happened 1 month after operation. For high-risk groups, we should prolong the follow-up time, enrich the observation data, and provide the clinical basis for reasonable and preventive intervention.

  19. Polyurethane acrylate networks including cellulose nanocrystals: a comparison between UV and EB- curing

    Science.gov (United States)

    Furtak-Wrona, K.; Kozik-Ostrówka, P.; Jadwiszczak, K.; Maigret, J. E.; Aguié-Béghin, V.; Coqueret, X.

    2018-01-01

    A water-based polyurethane (PUR) acrylate water emulsion was selected as a radiation curable matrix for preparing nanocomposites including cellulose nanocrystals (CNC) prepared by controlled hydrolysis of Ramie fibers. Cross-linking polymerization of samples prepared in the form of films or of 1 mm-thick bars was either initiated by exposure to the 395 nm light of a high intensity LED lamp or by treatment with low energy electron beam (EB). The conversion level of acrylate functions in samples submitted to increasing radiation doses was monitored by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were used to characterize changes in the glass transition temperature of the PUR-CNC nanocomposites as a function of acrylate conversion and of CNC content. Micromechanical testing indicates the positive effect of 1 wt% CNC on Young's modulus and on the tensile strength at break (σ) of cured nanocomposites. The presence of CNC in the PUR acrylate matrix was shown to double the σ value of the nanocomposite cured to an acrylate conversion level of 85% by treatment with a 25 kGy dose under EB, whereas no increase of σ was observed in UV-cured samples exhibiting the same acrylate conversion level. The occurrence of grafting reactions inducing covalent linkages between the polysaccharide nanofiller and the PUR acrylate matrix during the EB treatment is advanced as an explanation to account for the improvement observed in samples cured under ionizing radiation.

  20. An ORMOSIL-Containing Orthodontic Acrylic Resin with Concomitant Improvements in Antimicrobial and Fracture Toughness Properties

    Science.gov (United States)

    Rueggeberg, Frederick A.; Niu, Li-na; Mettenberg, Donald; Yiu, Cynthia K. Y.; Blizzard, John D.; Wu, Christine D.; Mao, Jing; Drisko, Connie L.; Pashley, David H.; Tay, Franklin R.

    2012-01-01

    Global increase in patients seeking orthodontic treatment creates a demand for the use of acrylic resins in removable appliances and retainers. Orthodontic removable appliance wearers have a higher risk of oral infections that are caused by the formation of bacterial and fungal biofilms on the appliance surface. Here, we present the synthetic route for an antibacterial and antifungal organically-modified silicate (ORMOSIL) that has multiple methacryloloxy functionalities attached to a siloxane backbone (quaternary ammonium methacryloxy silicate, or QAMS). By dissolving the water-insoluble, rubbery ORMOSIL in methyl methacrylate, QAMS may be copolymerized with polymethyl methacrylate, and covalently incorporated in the pressure-processed acrylic resin. The latter demonstrated a predominantly contact-killing effect on Streptococcus mutans ATCC 36558 and Actinomyces naselundii ATCC 12104 biofilms, while inhibiting adhesion of Candida albicans ATCC 90028 on the acrylic surface. Apart from its favorable antimicrobial activities, QAMS-containing acrylic resins exhibited decreased water wettability and improved toughness, without adversely affecting the flexural strength and modulus, water sorption and solubility, when compared with QAMS-free acrylic resin. The covalently bound, antimicrobial orthodontic acrylic resin with improved toughness represents advancement over other experimental antimicrobial acrylic resin formulations, in its potential to simultaneously prevent oral infections during appliance wear, and improve the fracture resistance of those appliances. PMID:22870322

  1. Recovery of Acrylic Acid Using Calcium Peroxide Nanoparticles: Synthesis, Characterisation, Batch Study, Equilibrium, and Kinetics

    Directory of Open Access Journals (Sweden)

    B. S. De

    2018-03-01

    Full Text Available Recovery of acrylic acid from aqueous solution using low-cost CaO2 nanoparticles was investigated. CaO2 nanoparticles were synthesized by co-precipitation technique and characterised using XRD and FTIR. A mechanism was proposed for adsorption of acrylic acid onto CaO2 nanoparticles based on FTIR analysis. Acrylic acid recovery is highly dependent on contact time, CaO2 nanoparticle dosage, initial acrylic concentration, and temperature. Langmuir, Freundlich, Dubinin-Radushkevich, Tempkin, Hill, Redlich-Peterson, Sips and Toth isotherms were used and well represented by Redlich-Peterson isotherm (R2 = 0.9998 as compared to other isotherms. Kinetic studies revealed pseudo-second-order kinetics (k2 = 1.962·10–4 g mg–1 min–1 for adsorption of acrylic acid onto CaO2 nanoparticles. CaO2 nanoparticles exhibited high acrylic acid recovery over varied concentration ranges. The acrylic acid can be regenerated by desorption from the surface of adsorbent and utilised for numerous applications. The presented results may be useful for the design of adsorption system using nanoparticles, which can be extended to other systems.

  2. Immediate loading of subcrestally placed dental implants in anterior and premolar sites.

    Science.gov (United States)

    Henningsen, Anders; Smeets, Ralf; Köppen, Kai; Sehner, Susanne; Kornmann, Frank; Gröbe, Alexander; Heiland, Max; Gerlach, Till

    2017-11-01

    Immediate loading of dental implants has been evolving into an appropriate procedure for the treatment of partially edentulous jaws. The purpose of this study was to evaluate the clinical success and radiological outcome of immediately and delayed loaded dental implants in anterior and premolar sites. In this retrospective study, data of 163 individuals requiring tooth removal with subsequent implant placement in anterior and premolar sites were analyzed. Implants were immediately loaded by provisional acrylic resin bridges or loaded with delay. Implants were followed up annually for up to 9 years including intraoral radiographs. A total of 285 implants in 163 patients were placed. 218 implants were immediately loaded and 67 implants with delay. Fifteen implants failed during the follow-up period resulting in survival rates of 94.5% for immediate loading and 95.5% for delayed loading. After an initial decrease of 0.3 mm in the first 12 months the marginal bone level remained stable. No statistically significant differences were found in marginal bone loss between immediately and delayed loaded implants (P = 0.518, 95% CI). Within the limits of this study, immediate loading of immediately subcrestally placed dental implants in anterior and premolar sites is a reliable treatment option for dental rehabilitation. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  3. Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

    Directory of Open Access Journals (Sweden)

    Bojanić Vaso

    2010-01-01

    Full Text Available Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in cellulose Y = 80.7%, and the degree of substitution of cellulose acrylate DS = 2.4 was determined. The grafting reaction of acrylate vinyl monomers onto cellulose in acetonitrile with initiator azoisobutyronitrile (AIBN in a nitrogen atmosphere was performed, by mixing for 5 h at acetonitrile boiling temperature. Radical copolymerization of synthesized cellulose acrylate and 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidinone and 9-vinylcarbazole, cellulose-poly-4-vinylpyridine (Cell-PVP, cellulose-poly-1- vinylimidazole (Cell-PVIm and cellulose-poly-1-vinyl-2-pyrrolidinone (Cell-P1V2P and cellulose-poly-9-vinylcarbazole (Cell-P9VK were synthesized. Acrylate cellulose and cellulose grafted copolymers were confirmed by IR spectroscopy, based on elementary analysis and the characteristics of grafted copolymers of cellulose were determined. The mass share of grafted copolymers, X, the relationship of derivative parts/cellulose vinyl group, Z, and the degree of grafting copolymers of cellulose (mass% were determined. In reaction of methyl iodide and cellulose-poly-4-vinylpyridine (Cell-PVP the cellulose-1-methyl-poly-4-vinylpyridine iodide (Cell-1-Me-PVPJ was synthesized. Cellulose acrylate and grafted copolymers were obtained with better thermal, electrochemical and ion-emulation properties for bonding of noble metals Au, Pt, Pd from water solutions. The synthesis optimization of cellulose acrylate was applied as a model for the synthesis of grafted

  4. STRATIFICATION TECHNIQUE IN MAXILLARY ANTERIOR INCISORS RESTORATION

    Directory of Open Access Journals (Sweden)

    Janet Kirilova

    2014-08-01

    Full Text Available Background: Because of their main characteristics: transparency, opalescence and color density, the tooth structures are extremely difficult to restore by means of completely inconspicuous restorations of the natural tooth tissue characteristics. The aim is to show successful aesthetic restoration of III Class dental lesions in upper incisors by means of high quality composites. Materials and method: A female patient visited the clinic being not satisfied with the esthetics of her front teeth. The intraoral examination showed previous restorations and carious lesions in 12, 11, 21, 22. After defining the tooth color a silicone key was made. The treatment was performed under anesthesia, the existing restorations were removed and the carious lesions in teeth 11, 12, 21, 22 were treated with restorations using Vanini edge preparation. The teeth were restored by means of stratification technique. After etching and rinsing, bonding was applied for 20 sec. and then polymerized. After fixing the silicone key enamel shade was applied and then dentine shades UD2, UD3, UD4 of 0.5mm thickness each. The polymerization was done layer by layer. Applied were 10 to 15 layers in total. The composite material was preheated in oven up to 55. Teeth 21 and 22 are restored with Enamel Plus HRi (Micerium. Results and Discussion: Excellent aesthetics is achieved with composite material. They have enamel and dentine shades and allow high quality aesthetics. The polishing is excellent in Enamel Plus HRi (Micerium which is typical for this type of composite. The result of the carious lesion treatment in this patient is real improvement of the dental appearance of her anterior incisors. Conclusion: Materials show excellent aesthetic results due to their characteristics and the stratification technique used.

  5. Diffraction at a Straight Edge

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 5. Diffraction at a Straight Edge: A Gem from Sommerfeld's Work in Classical Physics. Rajaram Nityananda. General Article Volume 20 Issue 5 May 2015 pp 389-400 ...

  6. DAVs: Red Edge and Outbursts

    Science.gov (United States)

    Luan, Jing

    2018-04-01

    As established by ground based surveys, white dwarfs with hydrogen atmospheres pulsate as they cool across the temperature range, 12500Kred edge is a two-decade old puzzle. Recently, Kepler discovered a number of cool DAVs exhibiting sporadic outbursts separated by days, each lasting several hours, and releasing \\sim 10^{33}-10^{34} {erg}. We provide quantitative explanations for both the red edge and the outbursts. The minimal frequency for overstable modes rises abruptly near the red edge. Although high frequency overstable modes exist below the red edge, their photometric amplitudes are generally too small to be detected by ground based observations. Nevertheless, these overstable parent modes can manifest themselves through nonlinear mode couplings to damped daughter modes which generate limit cycles giving rise to photometric outbursts.

  7. Edge Fracture in Complex Fluids.

    Science.gov (United States)

    Hemingway, Ewan J; Kusumaatmaja, Halim; Fielding, Suzanne M

    2017-07-14

    We study theoretically the edge fracture instability in sheared complex fluids, by means of linear stability analysis and direct nonlinear simulations. We derive an exact analytical expression for the onset of edge fracture in terms of the shear-rate derivative of the fluid's second normal stress difference, the shear-rate derivative of the shear stress, the jump in shear stress across the interface between the fluid and the outside medium (usually air), the surface tension of that interface, and the rheometer gap size. We provide a full mechanistic understanding of the edge fracture instability, carefully validated against our simulations. These findings, which are robust with respect to choice of rheological constitutive model, also suggest a possible route to mitigating edge fracture, potentially allowing experimentalists to achieve and accurately measure flows stronger than hitherto possible.

  8. Electron beam curable branched chain polyurethane acrylates for magnetic media coatings

    International Nuclear Information System (INIS)

    Ukachi, Takashi; Haga, Kei-ichi; Matsumura, Yoshio

    1989-01-01

    Electron beam curable binder resins have been studied to realize the high quality magnetic coatings. It was supposed that resins with a higher crosslink density could lead to magnetic coatings with higher abrasion resistance. Branched chain polyurethane acrylates show a higher degree of cure by irradiation with an electron beam in comparison with linear polyurethane acrylates. This paper describes the potential wear resistance between properties of magnetic coatings and the physical properties of the cured unpigmented branched chain polyurethane acrylates that were used as the binder resins. (author)

  9. Durability and Mechanical Performance of PMMA/Stone Sludge Nanocomposites for Acrylic Solid Surface Applications

    Directory of Open Access Journals (Sweden)

    Samah EL-Bashir

    2017-11-01

    Full Text Available Acrylic solid surface sheets were prepared by mixing different kinds of stone sludge fillers (SSF in Poly (methyl methacrylate (PMMA nanocomposites. PMMA nanocomposite syrups were made using free radical polymerization of methylmethacrylate (MMA, then two kinds of nanofillers were added, namely, hydrophilic nanosilica and clay Halloysite nanotubules (HNTs. Acrylic solid surface sheets were manufactured by mixing the syrups with SSFs. The morphology of the produced sheets was studied using optical, and Scanning Electron Microscopy (SEM that revealed the uniform distribution of stone sludge in the polymeric matrix. The study of the physical properties showed promising mechanical performance and durability of PMMA/SSF nanocomposites for acrylic solid surface applications.

  10. rac-tert-Butyl{2-hydroxy-2-[4-hydroxy-3-(hydroxymethylphenyl]ethyl}azanium acrylate

    Directory of Open Access Journals (Sweden)

    Wenju Liu

    2017-08-01

    Full Text Available The title salt, C13H22NO3+·C3H3O2−, comprises one salbutamol cation and an acrylate anion. The acrylate anion is linked to the salbutamol cation via an O—H...O and an N—H...O hydrogen bond. The C=C group of the acrylate anion is disordered over two positions, with refined site occupancies of 0.812 (7 and 0.188 (7. The crystal structure is stabilized by N—H...O and O—H...O hydrogen-bonding interactions.

  11. Strong composition dependence of adhesive properties of ultraviolet curing adhesives with modified acrylates

    Science.gov (United States)

    Feng, Yefeng; Li, Yandong; Wang, Fupeng; Peng, Cheng; Xu, Zhichao; Hu, Jianbing

    2018-05-01

    Ultraviolet (UV) curable adhesives have been widely researched in fields of health care and electronic components. UV curing systems with modified acrylic ester prepolymers have been frequently employed. In order to clarify composition dependence of adhesive properties of adhesives containing modified acrylates, in this work, several UV curing adhesives bearing urethane and epoxy acrylates were designed and fabricated. The effects of prepolymer, diluent, feed ratio, initiator and assistant on adhesive performances were investigated. This work might offer a facile route to gain promising high-performance UV curable adhesives with desired adhesive traits through regulating their compositions.

  12. Edge of polar cap patches

    Science.gov (United States)

    Hosokawa, K.; Taguchi, S.; Ogawa, Y.

    2016-04-01

    On the night of 4 December 2013, a sequence of polar cap patches was captured by an all-sky airglow imager (ASI) in Longyearbyen, Norway (78.1°N, 15.5°E). The 630.0 nm airglow images from the ASI of 4 second exposure time, oversampled the emission of natural lifetime (with quenching) of at least ˜30 sec, introduce no observational blurring effects. By using such high-quality ASI images, we succeeded in visualizing an asymmetry in the gradients between the leading/trailing edges of the patches in a 2-D fashion. The gradient in the leading edge was found to be 2-3 times steeper than that in the trailing edge. We also identified fingerlike structures, appearing only along the trailing edge of the patches, whose horizontal scale size ranged from 55 to 210 km. These fingers are considered to be manifestations of plasma structuring through the gradient-drift instability (GDI), which is known to occur only along the trailing edge of patches. That is, the current 2-D observations visualized, for the first time, how GDI stirs the patch plasma and such a mixing process makes the trailing edge more gradual. This result strongly implies a close connection between the GDI-driven plasma stirring and the asymmetry in the large-scale shape of patches and then suggests that the fingerlike structures can be used as markers to estimate the fine-scale structure in the plasma flow within patches.

  13. Use of anterior maxillary distraction osteogenesis in two cleft lip and palate patients

    Science.gov (United States)

    Srivastava, Dhirendra; Ghassemi, Alireza; Ghassemi, Mehrangiz; Showkatbakhsh, Rahman; Jamilian, Abdolreza

    2015-01-01

    Distraction osteogenesis (DO) has become a mainstream surgical technique for patients with jaw deformities. The aim of this study was to report the effect of DO done by a hyrax screw incorporated in an acrylic plate in the treatment of two maxillary deficient cases with cleft lip and palate. Two patients, a 24-year-old female and a 29-year-old male who suffered from maxillary deficiency and cleft lip and palate, were treated by DO. After making vertical cuts between the premolars on both sides and horizontal cuts similar to Le Fort 1, a hyrax screw was mounted on an acrylic plate for the slow anteroposterior expansion of maxillary arch. The expansion was achieved by turning the hyrax screw 0.8 mm per day after the latency period. Treatment was discontinued after achieving satisfactory over jet and occlusion. This study showed that anterior maxillary distraction is a reliable technique for correction of midfacial deformity arising out of cleft lip and palate. Incidences of complications are negligible compared to total maxillary distraction. PMID:26668459

  14. Use of anterior maxillary distraction osteogenesis in two cleft lip and palate patients.

    Science.gov (United States)

    Srivastava, Dhirendra; Ghassemi, Alireza; Ghassemi, Mehrangiz; Showkatbakhsh, Rahman; Jamilian, Abdolreza

    2015-01-01

    Distraction osteogenesis (DO) has become a mainstream surgical technique for patients with jaw deformities. The aim of this study was to report the effect of DO done by a hyrax screw incorporated in an acrylic plate in the treatment of two maxillary deficient cases with cleft lip and palate. Two patients, a 24-year-old female and a 29-year-old male who suffered from maxillary deficiency and cleft lip and palate, were treated by DO. After making vertical cuts between the premolars on both sides and horizontal cuts similar to Le Fort 1, a hyrax screw was mounted on an acrylic plate for the slow anteroposterior expansion of maxillary arch. The expansion was achieved by turning the hyrax screw 0.8 mm per day after the latency period. Treatment was discontinued after achieving satisfactory over jet and occlusion. This study showed that anterior maxillary distraction is a reliable technique for correction of midfacial deformity arising out of cleft lip and palate. Incidences of complications are negligible compared to total maxillary distraction.

  15. Gnathostomiasis of the anterior chamber

    Directory of Open Access Journals (Sweden)

    Barua P

    2007-01-01

    Full Text Available Ocular involvement with Gnathostoma spinigerum occurs years after the initial infection that is acquired by ingestion of poorly cooked, pickled seafood or water contaminated with third stage larvae. Here we report a case of gnathostomiasis of the left eye of a 32-year-old lady hailing from Meghalaya, India. Her vision had deteriorated to hand movement. Slit lamp examination revealed a live, actively motile worm in the anterior chamber, which was extracted by supra temporal limbal incision and visual acuity was restored.

  16. Bubble-point measurement for the binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Baek, Seung-Hyun; Byun, Hun-Soo

    2016-01-01

    Highlights: • Phase behaviours for the (CO_2 + propargyl (meth)acrylate) systems by static method were measured. • (P, x) isotherms is obtained at pressures up to 19.14 MPa and at temperature of (313.2 to 393.2) K. • The (CO_2 + propargyl acrylate) and (CO_2 + propargyl methacrylate) systems exhibit type-I behaviour. - Abstract: Acrylate and methacrylate (acrylic acid type) are compounds with weak polarity which show a non-ideal behaviour. Phase behaviour of these systems play a significant role as organic solvents in industrial processes. High pressure phase behaviour data were reported for binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide. The bubble-point curves for the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) mixtures were measured by static view cell apparatus at temperature range from 313.2 K to 393.2 K and at pressures below 19.14 MPa. The (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) systems exhibit type-I phase behaviour. The (carbon dioxide + (meth)acrylate) systems had continuous critical mixture curves with maximums in pressure located between the critical temperatures of carbon dioxide and propargyl acrylate or carbon dioxide and propargyl methacrylate. The solubility behaviour of propargyl (meth)acrylate in the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl acrylate) systems increases as the temperature increases at a fixed pressure. The experimental results for the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) systems correlate with the Peng–Robinson equation of state using a van der Waals one-fluid mixing rule. The critical properties of propargyl acrylate and propargyl methacrylate were predicted with the Joback–Lyderson group contribution and Lee–Kesler method.

  17. Anterior haptic flexing and in-the-bag subluxation of an accommodating intraocular lens due to excessive capsular bag contraction.

    Science.gov (United States)

    Kramer, Gregory D; Werner, Liliana; Neuhann, Tobias; Tetz, Manfred; Mamalis, Nick

    2015-09-01

    We describe the case of a patient who had cataract surgery with implantation of the hydrophilic acrylic Tetraflex accommodating intraocular lens (IOL), with subsequent development of capsulorhexis phimosis and in-the-bag IOL subluxation. Contraction of the capsular bag secondary to fibrosis resulted in significant anterior flexing of the lens haptic component. Explantation of the IOL-capsular bag complex was required 7 years after implantation. Histopathologic analysis demonstrated multiple areas of thick anterior subcapsular fibrosis. Pseudoexfoliative material was present throughout the surface of the lens capsule. Intraocular lenses manufactured from hydrophilic acrylic material are highly flexible and may be more susceptible to capsule contraction, even in the absence of predisposing ocular and systemic conditions. This case highlights the importance of developing guidelines regarding patient screening and selection for the appropriate use of accommodating and other highly flexible IOLs. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  18. Laparoscopic anterior resection and total mesorectal excision for rectal cancer: a prospective nonrandomized study.

    Science.gov (United States)

    Palanivelu, C; Sendhilkumar, K; Jani, Kalpesh; Rajan, P S; Maheshkumar, G S; Shetty, Roshan; Parthasarthi, R

    2007-04-01

    The purpose of this study was to present our experience of laparoscopic total mesorectal resection, including ultralow resection and coloanal anastomosis. Between 1993 and 2005, patients fit for general anesthesia, with resectable cancers, and with lower edge of tumor beyond 5 cm of the anal verge were subjected to laparoscopic anterior resection with sphincter preservation. Double stapling technique is used to establish bowel continuity. A total of 170 patients, 88 males and 82 females, were subjected to successful laparoscopic anterior resection, which included high anterior resection (n=90), low anterior resection (n=52), ultralow anterior resection (n=20), and coloanal anastomosis (n=8). The average age of patients was 58.4 years (12-90 years). Mean operating time was 130 min and mean hospital stay was 7 days. The morbidity was 13.5% with nil mortality. With an average follow-up of 49 months (range 9 years to 3 months), 9 patients developed local recurrence and 45 patients developed distant metastasis. In selected cases, laparoscopic anterior resection is possible for all levels of rectal tumors, allowing sphincter preservation and maintaining oncological safety.

  19. Anterior chest wall examination reviewed

    Directory of Open Access Journals (Sweden)

    F. Trotta

    2011-09-01

    Full Text Available Anterior chest wall involvement is not infrequently observed within inflammatory arthropaties, particularly if one considers seronegative spondiloarthritides and SAPHO syndrome. Physical examination is unreliable and conventional X-rays analysis is an unsatisfactory tool during diagnostic work-up of this region. Scintigraphic techniques yield informations both on the activity and on the anatomical extent of the disease while computerized tomography visualize the elementary lesions, such as erosions, which characterize the process. Moreover, when available, magnetic resonance imaging couple the ability to finely visualize such lesions with the possibility to show early alterations and to characterize the “activity” of the disease, presenting itself as a powerful tool both for diagnosis and follow-up. This review briefly shows the applications of imaging techniques for the evaluation of the anterior chest wall focusing on what has been done in the SAPHO syndrome which can be considered prototypical for this regional involvement since it is the osteo-articular target mainly affected by the disease.

  20. Carbon fiber reinforced thermoplastic composites from acrylic polymer matrices: Interfacial adhesion and physical properties

    Directory of Open Access Journals (Sweden)

    H. Kishi

    2017-04-01

    Full Text Available Acrylic polymers have high potential as matrix polymers for carbon fiber reinforced thermoplastic polymers (CFRTP due to their superior mechanical properties and the fact that they can be fabricated at relatively low temperatures. We focused on improving the interfacial adhesion between carbon fibers (CFs and acrylic polymers using several functional monomers for co-polymerization with methyl methacrylate (MMA. The copolymerized acrylic matrices showed good adhesion to the CF surfaces. In particular, an acrylic copolymer with acrylamide (AAm showed high interfacial adhesive strength with CFs compared to pure PMMA, and a hydroxyethyl acrylamide (HEAA copolymer containing both amide and hydroxyl groups showed high flexural strength of the CFRTP. A 3 mol% HEAA-copolymerized CFRTP achieved a flexural strength almost twice that of pure PMMA matrix CFRTP, and equivalent to that of an epoxy matrix CFRP.

  1. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ...-methyl acrylate copolymers identified in this section may be safely used as components of articles... Applied Nutrition (HFS-200), Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740...

  2. Biobased composites from thermoplastic polyurethane elastomer and cross-linked acrylated-epoxidized soybean oil

    Science.gov (United States)

    Soybean oil is an important sustainable material. Crosslinked acrylated epoxidized soybean oil (AESO) is brittle without flexibility and the incorporation of thermoplastic polyurethane improves its toughness for industrial applications. The hydrophilic functional groups from both oil and polyurethan...

  3. Color Stability of Heat‑cure Acrylic Resin Subjected to Simulated ...

    African Journals Online (AJOL)

    for effective plaque control, and these cleansers alter the physical properties of acrylic resin over a period of time. ... This is an open access article distributed under the terms of the Creative ..... Phillips' Science of Dental Materials. 11th ed.

  4. Surface coating of jeungjing wood (Paraserianthes Falcataria (L) NIELSEN) with acrylate resins by using radiation technique

    International Nuclear Information System (INIS)

    Suhariyono, Gatot

    1998-01-01

    An experiment on surface coating with acrylate resins has been done by using radiation technique to improve the quality and added value of jeunjing wood (Paraserianthes Falcataria (L) NIELSEN). Doses used in Electron Beam (BE) radiation were 20, 40, and 60 kGy. Epoxy acrylate and ester acrylate resins were used as coating materials after added with tripropylene glycol diacylate (TPGDA) monomer, 2,2-dimethyl-2hidroxy acetophenone (Darocur 1173) photoinitiator and talc as base coat. Top coat consists of este acrylate Setacure AM 548, after added with titanium dioxide OK 412 as additive respectively. Titanium dioxides in the mixture were varied at the concentration level of 0, 2, 4 and 6 % by weight. Conventional coating as comparison was carried out by using varnish as coating material. The results showed that the properties of film on jeunjing wood by EB curing are better than that of conventional one. (authors)

  5. Synthesis and characterization of copolymers 4,5-dihydroisoxazole and (-)-menthyl acrylates

    International Nuclear Information System (INIS)

    Passo, Joel A.; Merlo, Aloir A.; Eccher, Juliana; Bechtold, Ivan H.; Kelly, Stephen M.

    2012-01-01

    Five monomers 5-[4-(5-cyano-4,5-dihydroisoxazol-3-yl)phenoxy]undecyl acrylate (7a); n-alkyl 3-{4-[5-(acryloyloxyundecyl)oxyphenyl]}-4,5-dihydroisoxazole-5-carboxylate (7b,c for n-butyl and n-hexyl, respectively); 3-{4-[5-(acryloyloxyundecyl) oxyphenyl]}-4,5-dihydroisoxazole-5-carboxylic acid (7d) and (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl acrylate (9) and the corresponding copolymers 10a-d,11 and homopolymers 12 from 7a and 13 from 9 were designed and synthesized. Except for acrylate 9 which is derived from (-)-menthol, all of the monomers belong to the series containing the isoxazoline ring linked to the acrylate unit by a flexible spacer chain of eleven methylene units. They presented low glass temperature and despite birefringence behavior, these copolymers showed no mesomorphic properties. (author)

  6. Preparation and characterization of emulsifier-free polyphenylsilsesquioxane-poly (styrene–butyl acrylate) hybrid particles

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Ruiqin; Qiu, Teng, E-mail: qiuteng@mail.buct.edu.cn; Han, Feng; He, Lifan; Li, Xiaoyu, E-mail: lixy@mail.buct.edu.cn

    2013-10-01

    The core–shell polyphenylsilsesquioxane-poly (styrene–butyl acrylate) hybrid latex paticles with polyphenylsilsesquioxane as core and poly (styrene–butyl acrylate) as shell were successfully synthesized by seeded emulsion polymerization using polyphenylsisesquioxane (PPSQ) latex particles as seeds. X-ray diffraction (XRD) indicated that the polyphenylsilsesquioxane (PPSQ) had ladder structure, and PPSQ had incorporated into the hybrid latex particles. Transmission electron microscopy (TEM) confirmed that the resultant hybrid latex particles had the core–shell structure. TEM and dynamic light scattering (DLS) analysis indicated that the polyphenylsisesquioxane latex particles and obtained core–shell hybrid latex particles were uniform and possessed narrow size distributions. X-ray photoelectron spectroscopy (XPS) analysis also indicated that the PPSQ core particles were enwrapped by the polymer shell. In addition, compared with pure poly (styrene–butyl acrylate) latex film, the polyphenylsilsesquioxane-poly (styrene–butyl acrylate) hybrid latex film exhibited lower water uptake, higher pencil hardness and better thermal stability.

  7. Effect of microwave cured acrylic resin on candidal growth in complete denture

    International Nuclear Information System (INIS)

    Rasmy, A.H.M.

    2009-01-01

    This study was conducted to evaluate the effect of heat-cured acrylic resin denture base and microwave-cured acrylic resin denture base on candidal growth . Seven completely edentulous male patients with on history of denture wearing participated in this study. all the selected patients were re-habilitated by mucosa supported complete dentures .The dentures were constructed from conventional heat-cured acrylic resin denture base following monoplane concept of occlusion. Before dismissing the patients and one month after denture insertion, salivary samples were collected according to oral rinse technique. one month resting period was allowed so as candidal count can reach to normal, then dentures were re based using microwave-cured acrylic denture base, before denture insertion and one month after denture insertion, salivary sample were collected before and one month following the same oral rinse technique.

  8. Extraction of metal cations by polyterephthalamide microcapsules containing a poly(acrylic acid) gel.

    Science.gov (United States)

    Laguecir, A; Ernst, B; Frère, Y; Danicher, L; Burgard, M

    2002-01-01

    Polyterephthalamide microcapsules containing a poly(acrylic acid) gel as a macromolecular ligand (PAA-CAPS) were prepared using an original two step polymerization process in a water-in-oil inverse emulsion system. A polyamide microcapsule containing acrylic acid, initiator and cross-linking agent, is formed by interfacial polycondensation of terephthaloyl dichloride with hexamethylenediamine. In situ radical polymerization of the microcapsule core acrylic acid is initiated to obtain encapsulated poly(acrylic acid) gel. Reference polyamide microcapsules, i.e. without ligand (CAPS), were also synthesized. The mean diameter of synthesized microcapsules was 210 microm, and the microcapsule wall thickness was evaluated by SEM and TEM observations of microcapsule cross-section cuts. The microcapsule water content was determined by thermogravimetric experiments. The extractabilities of Cu(II), Ni(II), Co(II) and Zn(II) into PAA-CAPS were examined. The stripping of the various cations can be promoted in diluted hydrochloric acid solutions.

  9. Effects of water on starch-g-polystyrene and starch-g-poly(methyl acrylate) extrudates

    International Nuclear Information System (INIS)

    Henderson, A.M.; Rudin, A.

    1982-01-01

    Polystyrene and poly(methyl acrylate) were grafted onto wheat starch by gamma radiation and chemical initiation, respectively. The respective percent add-on values were 46 and 45; 68% of the polystyrene formed was grafted to starch, and corresponding proportion of poly(methyl acrylate) was 41%. The molecular weight distributions of the homopolymer and graft portions were characterized, and extrusion conditions were established for production of ribbon samples of starch-g-PS and starch-g-PMA. Both copolymer types were considerably weakened by soaking in water, and this effect was more immediate and drastic for starch-g-poly(methyl acrylate). Both graft copolymers regained their original tensile strengths on drying, but the poly(methyl acrylate) specimens did not recover their original unswollen dimensions and retained high breaking elongations characteristic of soaked specimens. Tensile and dynamic mechanical properties of extruded and molded samples of both graft polymers are reported, and plasticizing effects of water are summarized

  10. Synthesis and characterization of amylose grafted poly(acrylic acid) and its application in ammonia adsorption.

    Science.gov (United States)

    Chen, Qing; Yu, Haojie; Wang, Li; Abdin, Zain-Ul; Yang, Xinpeng; Wang, Junhua; Zhou, Weidong; Zhang, Hongtao; Chen, Xiao

    2016-11-20

    Amylose grafted poly(acrylic acid) (Am-g-PAA) was synthesized by graft copolymerization of amylose with acrylic acid. The structure of Am-g-PAA was confirmed by (1)H NMR and FT-IR spectra. The morphology, crystallinity and thermal properties of amylose and Am-g-PAA were investigated by SEM, XRD and TGA, respectively. The highest degree of substitution (DS) of carboxyl group was 1.96 which was obtained after reacted for 1h at 60°C. Acrylic acid to anhydroglucose mole ratio for DS was 19.81. It was found that a large number of carboxyl groups were grafted on the backbone of amylose. It was also found that ammonia adsorption capacity of amylose increased by grafting poly(acrylic acid) on the backbone of amylose. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Analysis of low-energy and high-frequency femtosecond laser for the construction of deep anterior donor corneal lamellae

    Directory of Open Access Journals (Sweden)

    Gustavo Victor

    2014-04-01

    Full Text Available Purpose: To evaluate the efficacy and reliability of a low-energy femtosecond laser with a high repetition rate for construction of deep anterior donor corneal lamellae. Methods: This was a prospective laboratory investigation. Twenty-five human corneal buttons were femtosecond laser cut to create thick anterior lamellae (diameter, 10mm; thickness, 500µm. The laser cuts were made using an LDV® femtosecond laser in a Ziemer® anterior chamber. To obtain a better edge, the lamellae were trephined with an 8mm trephine (Katena®. The central corneal thickness and the anterior lamellae were measured using a Mitutoyo® thickness gauge with an accuracy of 0.001mm. Results: The central thickness of the 25 corneas ranged from 500 to 705µm (mean, 584 ± 51µm. The thickness of the anterior lamellae ranged from 420 to 480µm (mean, 455 ± 12.7µm. The anterior lamellae diameters were 7.90 ± 0.1mm, and all laser cuts were round. The lamellar interfaces appeared regular by surgical microscopy. There were no cases of inter-lamellar adhesion. Conclusion: The LDV® femtosecond laser appears to be a safe and reliable instrument for cutting deep anterior lamellae from donor corneoscleral buttons. Minimal variation in donor lamellar depth with the laser will be useful for creating donor corneal tissue for deeper anterior lamellar keratoplasty or endothelial keratoplasty surgery or both from a single donor cornea.

  12. Polyurethane acrylate networks including cellulose nanocrystals: a comparison between UV and EB- curing

    International Nuclear Information System (INIS)

    Furtak-Wrona, K.; Kozik-Ostrówka, P.; Jadwiszczak, K.; Maigret, J.E.; Aguié-Béghin, V.; Coqueret, X.

    2018-01-01

    A water-based polyurethane (PUR) acrylate water emulsion was selected as a radiation curable matrix for preparing nanocomposites including cellulose nanocrystals (CNC) prepared by controlled hydrolysis of Ramie fibers. Cross-linking polymerization of samples prepared in the form of films or of 1 mm-thick bars was either initiated by exposure to the 395 nm light of a high intensity LED lamp or by treatment with low energy electron beam (EB). The conversion level of acrylate functions in samples submitted to increasing radiation doses was monitored by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were used to characterize changes in the glass transition temperature of the PUR-CNC nanocomposites as a function of acrylate conversion and of CNC content. Micromechanical testing indicates the positive effect of 1 wt% CNC on Young's modulus and on the tensile strength at break (σ) of cured nanocomposites. The presence of CNC in the PUR acrylate matrix was shown to double the σ value of the nanocomposite cured to an acrylate conversion level of 85% by treatment with a 25 kGy dose under EB, whereas no increase of σ was observed in UV-cured samples exhibiting the same acrylate conversion level. The occurrence of grafting reactions inducing covalent linkages between the polysaccharide nanofiller and the PUR acrylate matrix during the EB treatment is advanced as an explanation to account for the improvement observed in samples cured under ionizing radiation. - Highlights: • Nanocomposites were prepared from o/w PUR acrylate emulsion and CNC suspension. • Nanocomposite and reference materials were cured to the same conversion by UV or EB. • Introducing 1 wt% CNC in EB-cured composites doubles the tensile strength. • UV-cured nanocomposites did not show significant improvement in tensile strength.

  13. Evaluation of thermal conductivity of heat-cured acrylic resin mixed with A1203

    OpenAIRE

    Ebadian B.; Parkan MA.

    2002-01-01

    One of the most important characteristics of denture base is thermal conductivity. This property has a major role in secretions of salivary glands and their enzymes, taste of the food and gustatory response. Polymethyl methacrylate used in prosthodontics is relatively an insulator. Different materials such as metal fillers and ceramics have been used to solve this problem. The aim of this study was the evaluation of AI2O3 effect on thermal conductivity of heat-cured acrylic resin. Acrylic res...

  14. Characterization and bacterial anti-adherent effect on modified PMMA denture acrylic resin containing platinum nanoparticles

    OpenAIRE

    Nam, Ki-Young

    2014-01-01

    PURPOSE This study characterized the synthesis of a modified PMMA (Polymethyl methacrylate) denture acrylic loading platinum nanoparticles (PtN) and assessed its bacterial inhibitory efficacy to produce novel antimicrobial denture base material. MATERIALS AND METHODS Polymerized PMMA denture acrylic disc (20 mm × 2 mm) specimens containing 0 (control), 10, 50, 100 and 200 mg/L of PtN were fabricated respectively. The obtained platinum-PMMA nanocomposite (PtNC) was characterized by TEM (transm...

  15. Synthesis and Properties of IPN Hydrogels Based on Konjac Glucomannan and Poly(acrylic acid)

    Institute of Scientific and Technical Information of China (English)

    Bing LIU; Zhi Lan LIU; Ren Xi ZHUO

    2006-01-01

    Novel interpenetrating polymer network (IPN) hydrogels based on konjac glucomannan (KGM) and poly(acrylic acid) (PAA) were prepared by polymerization and cross-linking of acrylic acid (AA) in the pre-fabricated KGM gel. The IPN gel was analyzed by FT-IR. The studies on the equilibrium swelling ratio of IPN hydrogels revealed their sensitive response to environmental pH value. The results of in vitro degradation showed that the IPN hydrogels retain the enzymatic degradation character of KGM.

  16. Intra-oral electron therapy for carcinoma of the oral cavity using transparent acrylic tubes

    International Nuclear Information System (INIS)

    Terashima, Hiromi; Nakata, Hajime; Yoshiura, Takao; Ogawa, Masato; Yoshida, Akio; Ikemura, Kunio

    1986-01-01

    Intra-oral electron therapy for carcinoma of the oral cavity is a well-established treatment modality. However, the conventional metallic tubes were inconvenient to use because the irradiation field had to be confirmed by a side mirror. We devised transparent acrylic tubes which enable the positioning easy by confirming the tumor and irradiation field directry. Seven cases of various intra-oral carcinomas were treated with these new transparent acrylic tubes and good results were obtained. (author)

  17. In vitro cytotoxicity of self-curing acrylic resins of different colors

    Directory of Open Access Journals (Sweden)

    Luciana Borges Retamoso

    2014-08-01

    Full Text Available OBJECTIVE: The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. METHODS: Specimens were divided into 4 groups (n = 6 according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil: Group 1: clear acrylic resin; group 2: pink acrylic resin; group 3: blue acrylic resin and group 4: green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+, a glass specimen (C- and cell control (CC. Specimens were immersed in Minimum Eagle's Medium (MEM and incubated for 24 h at 37o C. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at 4 different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA with a 492-nm wavelength λ=492 nm. RESULTS: There were no statistical differences between the experimental groups and the CC and C- groups. CONCLUSION: Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material.

  18. Preparation and Property of Acrylic Acid Rare Earth Complex and Its Hydrosilylation

    Institute of Scientific and Technical Information of China (English)

    Zhang Ming; Chen Haiyan; Chen Xiaosong; Dai Shaojun; Inoue Shinich; Okamoto Hiroshi

    2004-01-01

    Acrylic acid rare earth complex was prepared. Its chemical composition was determined by chemical and elemental analysis, and its structure as well as properties was characterized using IR, Fluorescence and UV spectrum, and its solubility was also investigated. Meanwhile a kind of elastic functional polymer with rare earth units in the side chains was produced. It is confirmed by IR spectrum that the Si-H bonds really react with acrylic acid rare earth.

  19. Allergic contact dermatitis caused by nail acrylates in Europe. An EECDRG study

    DEFF Research Database (Denmark)

    Gonçalo, Margarida; Pinho, André; Agner, Tove

    2018-01-01

    BACKGROUND: Allergic contact dermatitis (ACD) caused by nail acrylates, also including methacrylates and cyanoacrylates here, is being increasingly reported. METHODS: A retrospective study in 11 European Environmental Contact Dermatitis Research Group (EECDRG) clinics collected information on cases......-hydroxypropyl methacrylate (88.6%), ethylene glycol dimethacrylate (69.2%), and ethyl cyanoacrylate (9.9%). CONCLUSIONS: Nail cosmetics were responsible for the majority of ACD cases caused by acrylates, affecting nail beauticians and consumers, and therefore calling for stricter regulation and preventive...

  20. Structure and properties of binary polystyrene-epoxy acrylate oligomer mixtures irradiated by electron beams

    International Nuclear Information System (INIS)

    Lomonosova, N.V.

    1995-01-01

    The change in the structure of oriented polymer-oligomer systems based on polystyrene (PS) with M > 10 6 and epoxy acrylate oligomers (aliphatic and aromatic) under irradiation by accelerated electrons was studied using birefringence, isometric heating, IR dichroism, and thermooptical analysis. Mechanical properties of these systems were investigated. It was found that, by adding aliphatic epoxy acrylate to PS and further irradiating this mixture, one can obtain both isotropic and oriented composites with higher strengths, elasticity moduli, and glass transition temperatures

  1. Protected Edge Modes without Symmetry

    Directory of Open Access Journals (Sweden)

    Michael Levin

    2013-05-01

    Full Text Available We discuss the question of when a gapped two-dimensional electron system without any symmetry has a protected gapless edge mode. While it is well known that systems with a nonzero thermal Hall conductance, K_{H}≠0, support such modes, here we show that robust modes can also occur when K_{H}=0—if the system has quasiparticles with fractional statistics. We show that some types of fractional statistics are compatible with a gapped edge, while others are fundamentally incompatible. More generally, we give a criterion for when an electron system with Abelian statistics and K_{H}=0 can support a gapped edge: We show that a gapped edge is possible if and only if there exists a subset of quasiparticle types M such that (1 all the quasiparticles in M have trivial mutual statistics, and (2 every quasiparticle that is not in M has nontrivial mutual statistics with at least one quasiparticle in M. We derive this criterion using three different approaches: a microscopic analysis of the edge, a general argument based on braiding statistics, and finally a conformal field theory approach that uses constraints from modular invariance. We also discuss the analogous result for two-dimensional boson systems.

  2. Imaging findings of anterior hip dislocations

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Kyle [Mallinckrodt Institute of Radiology, Department of Radiology, St. Louis, MO (United States); Leslie, Michael [Yale School of Medicine, Department of Orthopedics and Rehabilitation, New Haven, CT (United States); Menn, Kirsten; Haims, Andrew [Yale University School of Medicine, Department of Radiology and Biomedical Imaging, New Haven, CT (United States)

    2017-06-15

    Anterior hip dislocations are rare orthopedic emergencies resulting from high-energy trauma and have unique imaging characteristics on radiography, computed tomography (CT), and magnetic resonance imaging (MRI). Imaging findings on CT and MRI allow for the prompt recognition and classification of anterior hip dislocations, which guides patient management and reduces complications. The purpose of this article is to review imaging findings of anterior hip dislocations, specifically focusing on CT and MRI. (orig.)

  3. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

    Science.gov (United States)

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

    2016-06-01

    Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

  4. In situ reactive compatibilization of natural rubber/acrylic-bentonite composites via peroxide-induced vulcanization

    International Nuclear Information System (INIS)

    Fu, Lihua; Lei, Zhiwen; Xu, Chuanhui; Chen, Yukun

    2016-01-01

    To achieve good interfacial interaction between fillers and rubber matrix is always a hot topic in rubber reinforcing industry. In this paper, acid activated bentonite (Bt) was alkalified to be alkaline calcium-bentonite (ACBt), then acrylic acid (AA) was employed to modify ACBt to obtain acrylic-bentonite (ABt). The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) illustrated that acrylate groups were chemically boned onto the surface of Bt and the layer spacing of Bt was increased. During peroxide-induced vulcanization, in situ compatibilization of ABt was realized via the reaction between the unsaturated bonds of acrylate groups on the surface of Bt and the natural rubber (NR) chains. This resulted in an enhanced cross-linked network which contributed to the improved mechanical properties of NR/ABt composites. - Highlights: • Acrylate groups were chemically boned onto the surface of bentonite. • In situ compatibilization was realized via the reaction of acrylate group and NR. • ABt particles participated in forming the NR crosslink network. • A potential reinforcing material options for “white” rubber products.

  5. In situ reactive compatibilization of natural rubber/acrylic-bentonite composites via peroxide-induced vulcanization

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Lihua; Lei, Zhiwen [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Xu, Chuanhui, E-mail: xuhuiyee@gxu.edu.cn [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Chen, Yukun, E-mail: cyk@scut.edu.cn [The Key Laboratory of Polymer Processing Engineering, Ministry of Education, China(South China University of Technology), Guangzhou, 510640 (China)

    2016-02-15

    To achieve good interfacial interaction between fillers and rubber matrix is always a hot topic in rubber reinforcing industry. In this paper, acid activated bentonite (Bt) was alkalified to be alkaline calcium-bentonite (ACBt), then acrylic acid (AA) was employed to modify ACBt to obtain acrylic-bentonite (ABt). The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) illustrated that acrylate groups were chemically boned onto the surface of Bt and the layer spacing of Bt was increased. During peroxide-induced vulcanization, in situ compatibilization of ABt was realized via the reaction between the unsaturated bonds of acrylate groups on the surface of Bt and the natural rubber (NR) chains. This resulted in an enhanced cross-linked network which contributed to the improved mechanical properties of NR/ABt composites. - Highlights: • Acrylate groups were chemically boned onto the surface of bentonite. • In situ compatibilization was realized via the reaction of acrylate group and NR. • ABt particles participated in forming the NR crosslink network. • A potential reinforcing material options for “white” rubber products.

  6. Peculiarities of the photoinitiator-free photopolymerization of pentabrominated and pentafluorinated aromatic acrylates and methacrylates.

    Science.gov (United States)

    Daikos, Olesya; Naumov, Sergej; Knolle, Wolfgang; Heymann, Katja; Scherzer, Tom

    2016-11-30

    Pentabrominated and fluorinated aromatic (meth)acrylates as well as their non-halogenated counterparts have been studied with the aim to avoid conventional photoinitiators and to overcome some negative consequences related to their use. Therefore, RTIR spectroscopy, laser flash photolysis and GC/MS were utilized. Even low concentrations (1 to 5 wt%) of brominated (meth)acrylates in the model varnish lead to initiation of a photopolymerization reaction under exposure to UV light with λ > 300 nm. This is due to the fact that excitation of the aryl moiety leads to the homolysis of bromine-phenyl bonds with a high quantum yield of ∼0.15-0.3. Both, bromine radicals released from either ortho, meta or para position as well as the corresponding tetrabromoaryl radicals, may initiate the polymerization of brominated aromatic (meth)acrylates. In contrast, fluorinated aromatic (meth)acrylates undergo α-cleavage of the carboxyl group (as in the case of non-halogenated aromatic (meth)acrylates), if excitation of the acrylic double bonds is done with UV-C light (λ fluorinated) and 0.16-0.36 (non-halogenated compounds), despite the different pathway of fragmentation. Thus, in all cases the efficiency of initiation is comparable to conventional photoinitiators. Quantum chemical calculations of orbitals involved and of the Gibbs free energy of transients and products support the suggested reaction pathway.

  7. Effect of autoclave postpolymerization treatments on the fracture toughness of autopolymerizing dental acrylic resins.

    Science.gov (United States)

    Durkan, Rukiye; Gürbüz, Ayhan; Yilmaz, Burak; Özel, M Birol; Bağış, Bora

    2012-06-26

    Microwave and water bath postpolymerization have been suggested as methods to improve the mechanical properties of heat and autopolymerizing acrylic resins. However, the effects of autoclave heating on the fracture properties of autopolymerizing acrylic resins have not been investigated. The aim of this study was to assess the effectiveness of various autoclave postpolymerization methods on the fracture properties of 3 different autopolymerizing acrylic resins. Forty-two specimens of 3 different autopolymerizing acrylic resins (Orthocryl, Paladent RR and Futurajet) were fabricated (40x8x4mm), and each group was further divided into 6 subgroups (n=7). Control group specimens remained as processed (Group 1). The first test group was postpolymerized in a cassette autoclave at 135°C for 6 minutes and the other groups were postpolymerized in a conventional autoclave at 130°C using different time settings (5, 10, 20 or 30 minutes). Fracture toughness was then measured with a three-point bending test. Data were analyzed by ANOVA followed by the Duncan test (α=0.05). The fracture toughness of Orthocryl and Paladent-RR acrylic resins significantly increased following conventional autoclave postpolymerization at 130°C for 10 minutes (Pautoclave postpolymerized Futurajet was not significantly different than its control specimens (Pautoclaved at 130°C for 10 minutes. Within the limitations of this study, it can be suggested that autoclave postpolymerization is an effective method for increasing the fracture toughness of tested autoploymerized acrylic resins.

  8. Allergic contact dermatitis from sculptured acrylic nails: special presentation with an airborne pattern

    Science.gov (United States)

    Maio, Paula; Carvalho, Rodrigo; Amaro, Cristina; Santos, Raquel; Cardoso, Jorge

    2012-01-01

    Methylmethacrylate was first reported in 1941 as a cause of contact dermatitis. Since then, occupational contact allergies to acrylates in dentistry, orthopedic surgery, printing industry and industry have been reported, but few reports are found in the literature as a consequence of the contact with sculptured artificial acrylic nails which are increasingly popular. We describe here 3 patients with contact allergy to acrylates in artificial sculptured nails. Patch tests were performed with the Portuguese baseline series of contact allergens and an extended series of acrylates were applied. In particular, we tested three female patients with allergic contact dermatitis from sculptured acrylic nails. Two of these patients were both customers and also technical nail beauticians. Two patients developed periungual eczema; one presented only with face and eyelid dermatitis had no other lesions. The tests showed positive reaction to 2-hydroxyethylmethacrylate (2-HEMA) and 2-hydroxypropylmethacrylate (2-HPMA) in all the three patients. Our cases demonstrate the variety of clinical presentations of allergic contact dermatitis from acrylic sculptured nails. They show the need to warn patients of persistent and sometimes permanent side effects of these products. They also emphasize the importance of cosmetic ingredient labeling. PMID:25386316

  9. Steel Protective Coating Based on Plasticized Epoxy Acrylate Formulation Cured by Electron Beam Irradiation

    International Nuclear Information System (INIS)

    Ibrahim, M.S.; Said, H.M.; Mohamed, I.M.; Mohamed, H.A.; Kandile, N.G.

    2011-01-01

    Electron beam (EB) was used to cure coatings based on epoxy acrylate oligomer (EA) and different plasticizers such as epoxidized soybean oil, glycerol and castor oil. The effect of irradiation doses (10, 25, 50 kGy) on the curing epoxy acrylate formulations containing plasticizers was studied. In the addition, the effect of the different plasticizers on the end use performance properties of epoxy acrylate coatings such as hardness, bending, adhesion, acid and alkali resistance tests were investigated. It was observed that the incorporation of castor oil in epoxy acrylate, diluted by 1,6 hexandiol diacrylate monomer (HD) with a ratio (EA 70%, HD 20%, castor oil 10%) under the dose 10 kGy improved the physical, chemical and mechanical properties of cured films than the other plasticizers. On the other hand, sunflower free fatty acids were epoxidized in-situ under well established conditions and then was subjected to react with aniline in sealed ampoules under inert atmosphere at 140 degree C. The produced adduct was added at different concentrations to epoxy acrylate coatings under certain EB irradiation dose and then evaluated as corrosion inhibitors for carbon steel surfaces in terms of weight loss measurements and corrosion resistance tests. It was observed that the formula containing 0.4 gm of aniline adduct / 100 gm epoxy acrylate resin gave the best corrosion protection for carbon steel

  10. Shoulder Magnetic Resonance Arthrography: A Prospective Randomized Study of Anterior and Posterior Ultrasonography-Guided Contrast Injections

    Energy Technology Data Exchange (ETDEWEB)

    Koivikko, M.P.; Mustonen, A.O.T. (Dept. of Radiology, Helsinki Univ. Central Hospital, Helsinki (Finland))

    2008-10-15

    Background: Magnetic resonance (MR) arthrography is an accurate imaging method for internal shoulder derangements and rotator cuff pathologies. Both anterior and posterior contrast injection techniques, under palpatory, fluoroscopic, or ultrasonographic guidance have been described in the literature. However, clinical comparisons of the injection techniques remain few. Purpose: To compare the performance of anterior and posterior ultrasonography (US)-guided arthrography injections of the shoulder regarding patient discomfort and influence on diagnostic MR reading, and to illustrate the typical artifacts resulting from contrast leakage in the respective techniques. Material and Methods: 43 MR arthrographies were prospectively randomized into anterior and posterior US-guided contrast injections and performed by two radiologists, with the study of artifacts from contrast leakage. Pain from the injections was assessed by a survey utilizing a 100-mm visual analogue scale (VAS). Results: Of the 23 anterior injections, nine caused contrast artifacts in the subscapular tendon, and in three the leakage extended further anteriorly. Of the 20 posterior injections, 12 showed injection artifacts of the rotator cuff, extending outside the cuff in seven. Two of the anterior and none of the posterior artifacts compromised diagnostic quality. In posterior injections, the leakage regularly occurred at the caudal edge of the infraspinatus muscle and was easily distinguishable from rotator cuff tears. All patients completed the pain survey. Mean VAS scores were 25.0 (median 18, SD 22) for anterior, and 25.4 (median 16, SD 25) for posterior injections. The two radiologists achieved different mean VAS scores but closely agreed as to anterior and posterior VAS scores. Conclusion: Arthrography injections were fairly simple to perform under US guidance. Patient discomfort for anterior and posterior injections was equally minor. A tailored approach utilizing anterior or posterior injections

  11. Inner Synovial Membrane Footprint of the Anterior Elbow Capsule: An Arthroscopic Boundary

    Directory of Open Access Journals (Sweden)

    Srinath Kamineni

    2015-01-01

    Full Text Available Introduction. The purpose of this study is to describe the inner synovial membrane (SM of the anterior elbow capsule, both qualitatively and quantitatively. Materials and Methods. Twenty-two cadaveric human elbows were dissected and the distal humerus and SM attachments were digitized using a digitizer. The transepicondylar line (TEL was used as the primary descriptor of various landmarks. The distance between the medial epicondyle and medial SM edge, SM apex overlying the coronoid fossa, the central SM nadir, and the apex of the SM insertion overlying the radial fossa and distance from the lateral epicondyle to lateral SM edge along the TEL were measured and further analyzed. Gender and side-to-side statistical comparisons were calculated. Results. The mean age of the subjects was 80.4 years, with six male and five female cadavers. The SM had a distinctive double arched attachment overlying the radial and coronoid fossae. No gender-based or side-to-side quantitative differences were noted. In 18 out of 22 specimens (81.8%, an infolding extension of the SM was observed overlying the medial aspect of the trochlea. The SM did not coincide with the outer fibrous attachment in any specimen. Conclusion. The humeral footprint of the synovial membrane of the anterior elbow capsule is more complex and not as capacious as commonly understood from the current literature. The synovial membrane nadir between the two anterior fossae may help to explain and hence preempt technical difficulties, a reduction in working arthroscopic volume in inflammatory and posttraumatic pathologies. This knowledge should allow the surgeon to approach this aspect of the anterior elbow compartment space with the confidence that detachment of this synovial attachment, to create working space, does not equate to breaching the capsule. Alternatively, stripping the synovial attachment from the anterior humerus does not constitute an anterior capsular release.

  12. Herniation of the anterior lens capsule

    Directory of Open Access Journals (Sweden)

    Pereira Nolette

    2007-01-01

    Full Text Available Herniation of the anterior lens capsule is a rare abnormality in which the capsule bulges forward in the pupillary area. This herniation can be mistaken for an anterior lenticonus where both the capsule and the cortex bulge forward. The exact pathology behind this finding is still unclear. We report the clinical, ultrasound biomicroscopy (UBM and histopathological findings of a case of herniation of the anterior lens capsule. UBM helped to differentiate this entity from anterior lenticonus. Light microscopy revealed capsular splitting suggestive of capsular delamination and collection of fluid (aqueous in the area of herniation giving it a characteristic appearance.

  13. All-graphene edge contacts

    DEFF Research Database (Denmark)

    Jacobsen, Kåre Wedel; Falkenberg, Jesper Toft; Papior, Nick Rübner

    2016-01-01

    Using ab-initio methods we investigate the possibility of three-terminalgraphene "T-junction" devices and show that these all-graphene edge contactsare energetically feasible when the 1D interface itself is free from foreignatoms. We examine the energetics of various junction structures as a func......Using ab-initio methods we investigate the possibility of three-terminalgraphene "T-junction" devices and show that these all-graphene edge contactsare energetically feasible when the 1D interface itself is free from foreignatoms. We examine the energetics of various junction structures...... to be in therange of 1-10 kΩμm which is comparable to the best contact resistance reportedfor edge-contacted graphene-metal contacts. We conclude that conductingall-carbon T-junctions should be feasible....

  14. Toxic Anterior Segment Syndrome (TASS

    Directory of Open Access Journals (Sweden)

    Özlem Öner

    2011-12-01

    Full Text Available Toxic anterior segment syndrome (TASS is a sterile intraocular inflammation caused by noninfectious substances, resulting in extensive toxic damage to the intraocular tissues. Possible etiologic factors of TASS include surgical trauma, bacterial endotoxin, intraocular solutions with inappropriate pH and osmolality, preservatives, denatured ophthalmic viscosurgical devices (OVD, inadequate sterilization, cleaning and rinsing of surgical devices, intraocular lenses, polishing and sterilizing compounds which are related to intraocular lenses. The characteristic signs and symptoms such as blurred vision, corneal edema, hypopyon and nonreactive pupil usually occur 24 hours after the cataract surgery. The differential diagnosis of TASS from infectious endophthalmitis is important. The main treatment for TASS formation is prevention. TASS is a cataract surgery complication that is more commonly seen nowadays. In this article, the possible underlying causes as well as treatment and prevention methods of TASS are summarized. (Turk J Oph thal mol 2011; 41: 407-13

  15. Improving color constancy by photometric edge weighting

    NARCIS (Netherlands)

    Gijsenij, A.; Gevers, T.; van de Weijer, J.

    2012-01-01

    Edge-based color constancy methods make use of image derivatives to estimate the illuminant. However, different edge types exist in real-world images, such as material, shadow, and highlight edges. These different edge types may have a distinctive influence on the performance of the illuminant

  16. The knife-edge chamber

    International Nuclear Information System (INIS)

    Barasch, E.F.; Bowcock, T.J.V.; Drew, M.M.; Elliott, S.M.; Lee, B.; McIntyre, P.M.; Pang, Y.; Popovic, M.; Smith, D.D.

    1990-01-01

    In this paper the design for a new technology for particle track detectors is described. Using standard IC fabrication techniques, a pattern of microscopic knife edges and field-shaping electrodes can be fabricated on a silicon substrate. The knife-edge chamber uniquely offers attractive performance for the track chambers required for SSC detectors, for which no present technology is yet satisfactory. Its features include: excellent radiation hardness (10 Mrad), excellent spatial resolution (∼20 μm), short drift time (20 ns), and large pulse height (1 mV)

  17. Radiolysis of poly(acrylic acid) in aqueous solution

    Science.gov (United States)

    Ulanski, Piotr; Bothe, Eberhard; Hildenbrand, Knut; Rosiak, Janusz M.; von Sonntag, Clemens

    1995-02-01

    Poly(acrylic acid), PAA, reacts with OH-radicals yielding -CHCH(CO 2H)- (β-radicals) and -CH 2C(CO 2H)- (α-radicals) in a ratio of approximately 2:1. This estimate is based on pulse radiolysis data where the absorption spectrum of the PAA-radicals was compared with the spectra of α-radicals from model systems. The β-radicals convert slowly into α-radicals ( k = 0.7 s -1 at pH 10). This process has also been observed by ESR. At PAA-concentrations of 10 -2 mol dm -3 chain scission dominates over other competing reactions except at low pH. The rate of chain scission was followed by pulse conductometry and in the pH range 7-9 k = 4 × 10 -2s -1 was observed. Oxygen reacts with PAA-radicals with k = 3.1 × 10 8 dm 3 mol -1 s -1 at pH 3.5 and k = 1.0 × 10 8 dm 3 mol -1 s -1 at pH 10. The corresponding peroxyl radicals undergo slow intramolecular H-transfer yielding a UV-absorbing product whose properties are that of 1,3-diketones.

  18. Radiolysis of poly(acrylic acid) in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Ulanski, P [Max-Planck-Institut fuer Strahlenchemie, Muelheim an der Ruhr (Germany); [Politechnika Lodzka, Lodz (Poland); Bothe, E; Hildenbrand, K; Sonntag, C von [Max-Planck-Institut fuer Strahlenchemie, Muelheim an der Ruhr (Germany); Rosiak, J M [Politechnika Lodzka, Lodz (Poland)

    1995-10-01

    Poly(acrylic acid), PAA, reacts with OH-radicals yielding -CH-CH(CO{sub 2}H)- ({beta}-radicals) and -CH{sub 2}-C(CO{sub 2}H)-({alpha}-radicals) in a ratio of approximately 2:1. This estimate is based on pulse radiolysis data where the absorption spectrum of the PAA-radicals was compared with the spectra of {alpha}-radicals from model systems. The {beta}-radicals convert slowly into {alpha}-radicals (k = 0.7s {sup -1} at pH 10). This process has also been observed by ESR. At PAA-concentrations of 10{sup -2} mol dm{sup -3} chain scission dominates over other competing reactions except at low pH. The rate of chain scission was followed by pulse conductometry and in the pH range 7-9 k = 4 x 10{sup -2}s{sup -1} was observed. Oxygen reacts with PAA-radicals with k = 3.1 x 10{sup 8} dm{sup 3} mol{sup -1} s{sup -1} at pH 3.5 and k = 1.0 x 10{sup 8} dm{sup 3} mol{sup -1} s{sup -1} at pH 10. The corresponding peroxyl radicals undergo slow intramolecular H-transfer yielding a UV-absorbing product whose properties are that of 1,3-diketones. (Author).

  19. Perancangan Aplikasi Monitoring Produksi pada Perusahaan yang Memproduksi Acrylic

    Directory of Open Access Journals (Sweden)

    Nilo Legowo

    2012-06-01

    Full Text Available A lot of problems often occur in production monitoring, because companies still rely on manual processing system. Therefore, this research is objected to facilitate the monitoring of production processes, to minimize human error in the production process, to make automatic the process of existing transactions, toclarify the duties of production monitoring of an acrylic manufacturer. The research methodology used is literature study by reviewing previous theories and studies related to the topic. Furthermore, analysis method by studying the running system of the company as well as evaluating the distributed questionnaire and analyzing the results. And finally is the design method using the Object-Oriented with UML. The research resulted in an application design of a production monitoring system. The result of this design has been implemented into the selected DBMS. The new monitoring system helps monitoring the production system properly, as well as makes the transaction run systematically. The each production process starting from project orders, sample orders,sales orders, material releases, production, assembly, and delivery order within can be monitored quickly and properly. The activity reports can also be generated more systematically and comprehensibly.

  20. Radiation-induced synthesis of poly(acrylic acid) nanogels

    Science.gov (United States)

    Matusiak, Malgorzata; Kadlubowski, Slawomir; Ulanski, Piotr

    2018-01-01

    Nanogel is a two-component system of a diameter in the range of tens of nanometers, consisting of an intramolecularly crosslinked polymer chain and solvent, typically water, filling the space between segments of the macromolecule. Microgels are bigger than nanogels and their size range is between 100 nm to 100 μm. One of the methods used for synthesizing nanogels is linking the segments of a single macromolecule with the use of ionizing radiation, by intramolecular recombination of radiation-generated polymer radicals. The main advantage of this technique is absence of monomers, catalysts, surfactants or crosslinking agents. This method is an interesting alternative way of synthesizing polymeric carriers for biomedical applications. The aim of the study was radiation synthesis and characterization of poly(acrylic acid) - PAA - nanogels and microgels. The physico-chemical properties were described by determination of weight-average molecular weight and dimensions (radius of gyration, hydrodynamic radius) of the nanogels and microgels. Influence of polymer concentration and dose on these parameters was analyzed. Adjusting the PAA concentration and absorbed dose, one can control the molecular weight and dimensions of nanogels. The solutions of PAA were irradiated with two sources of ionizing radiation: γ-source and electron accelerator. The former method yields mainly microgels due to prevailing intermolecular crosslinking, while the latter promotes intramolecular recombination of PAA-derived radicals and in consequence formation of nanogels. In the future radiation-synthesized PAA nanogels, after functionalization, will be tested as carriers for delivering radionuclides to the tumor cells.

  1. INFIBRA: machine vision inspection of acrylic fiber production

    Science.gov (United States)

    Davies, Roger; Correia, Bento A. B.; Contreiras, Jose; Carvalho, Fernando D.

    1998-10-01

    This paper describes the implementation of INFIBRA, a machine vision system for the inspection of acrylic fiber production lines. The system was developed by INETI under a contract from Fisipe, Fibras Sinteticas de Portugal, S.A. At Fisipe there are ten production lines in continuous operation, each approximately 40 m in length. A team of operators used to perform periodic manual visual inspection of each line in conditions of high ambient temperature and humidity. It is not surprising that failures in the manual inspection process occurred with some frequency, with consequences that ranged from reduced fiber quality to production stoppages. The INFIBRA system architecture is a specialization of a generic, modular machine vision architecture based on a network of Personal Computers (PCs), each equipped with a low cost frame grabber. Each production line has a dedicated PC that performs automatic inspection, using specially designed metrology algorithms, via four video cameras located at key positions on the line. The cameras are mounted inside custom-built, hermetically sealed water-cooled housings to protect them from the unfriendly environment. The ten PCs, one for each production line, communicate with a central PC via a standard Ethernet connection. The operator controls all aspects of the inspection process, from configuration through to handling alarms, via a simple graphical interface on the central PC. At any time the operator can also view on the central PC's screen the live image from any one of the 40 cameras employed by the system.

  2. Synthesis, characterization and antimicrobial activity of important heterocyclic acrylic copolymers

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available The acrylate monomer, 7-acryloyloxy-4-methyl coumarin (AMC has been synthesized by reacting 7-hydroxy-4-methyl coumarin, with acryloyl chloride in the presence of NaOH at 0–5°C. Copolymers of 7-acryloyloxy-4-methyl coumarin (AMC with vinyl acetate (VAc were synthesized in DMF (dimethyl formamide solution at 70±1°C using 2,2′-azobisisobutyronitrile (AIBN as an initiator with different monomer-to-monomer ratios in the feed. The copolymers were characterized by Fourier transform infra red (FTIR spectroscopy. The copolymer composition was evaluated by 1H-NMR (proton nuclear magnetic resonance and was further used to determine reactivity ratios. The monomer reactivity ratios for AMC (M1-VAc (M2 pair were determined by the application of conventional linearization methods such as Fineman-Ross (r1 = 0.6924; r2 = 0.6431, Kelen-Tüdõs (r1 = 0.6776; r2 = 0.6374 and extended Kelen-Tüdõs (r1 = 0.6657; r2 = 0.6256. Thermo gravimetric analysis showed that thermal decomposition of the copolymers occurred in single stage in the temperature range of 263–458°C. The molecular weights of the polymers were determined using gel permeation chromatography. The homo and copolymers were tested for their antimicrobial properties against selected microorganisms.

  3. Strategic design and fabrication of acrylic shape memory polymers

    Science.gov (United States)

    Park, Ju Hyuk; Kim, Hansu; Ryoun Youn, Jae; Song, Young Seok

    2017-08-01

    Modulation of thermomechanics nature is a critical issue for an optimized use of shape memory polymers (SMPs). In this study, a strategic approach was proposed to control the transition temperature of SMPs. Free radical vinyl polymerization was employed for tailoring and preparing acrylic SMPs. Transition temperatures of the shape memory tri-copolymers were tuned by changing the composition of monomers. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analyses were carried out to evaluate the chemical structures and compositions of the synthesized SMPs. The thermomechanical properties and shape memory performance of the SMPs were also examined by performing dynamic mechanical thermal analysis. Numerical simulation based on a finite element method provided consistent results with experimental cyclic shape memory tests of the specimens. Transient shape recovery tests were conducted and optical transparence of the samples was identified. We envision that the materials proposed in this study can help develop a new type of shape-memory devices in biomedical and aerospace engineering applications.

  4. Dewatering of Yoghurt Using Permeable Membrane and Acrylic Superabsorbent Hydrogel

    Directory of Open Access Journals (Sweden)

    A. Ahmadpour

    2008-02-01

    Full Text Available Conventional processes of food dewatering, such as thermal, have undesirable and destruction effects on vitamins, aromatic compounds and pigments. In addition, they are accompanied with some technological complications and energy consumption. Thus, food concentration processes are directed to non-thermal techniques or methods with reduced heat effects. Superabsorbents are highly hydrophilic polymer networks which can absorb water and aqueous solutions some hundred times of their weights and retain them. These materials are subgroups of hydrogel family that are transformed into gels after absorbing water. In the present research, the possibilities of yoghurt dewatering using superabsorbents have been investigated for the first time in Iran and some remarkable results are obtained for this vital product. In the experiments carried out to investigate the effect of these absorbents on normal method of yoghurt concentration (use of permeable membrane, type of bed (wide and vertical and time are also studied. The percentage of total soluble solids and dry solids of dewatered samples were measured in different time intervals up to 180 min. The results showed that superabsorbent on a wide bed would reduce the concentration time to one third. In other words, in a certain time interval, more than 70% increase in yoghurt dry solids was observed compared to normal method. These results show that acrylic superabsorbent hydrogel can be applied as highly hydrophilic material in non-thermal food dewatering methods.

  5. Characterization of Functionalized Acrylic acid /4- Vinyl Pyridine Graft Copolymers

    International Nuclear Information System (INIS)

    Kamal, H.; Mahmoud, Gh.A.; Hegazy, D.E.

    2009-01-01

    Properties and characterization of the membranes prepared by radiation grafting of acrylic acid (AAc) or/ and 4-vinyl pyridine (4VP) onto low density polyethylene (LDPE) and polypropylene (PP) films were carried out. The FTIR spectra for the grafted membranes were studied to evaluate the structure change as a result of grafting. The swelling behaviour of the graft copolymer in methanol was studied. It was found that the grafting of AAc and/ or 4- VP onto LDPE and PP resulted in introducing good hydrophilic properties to such polymer substrates. The hydrophilic properties were directly proportional to the amount of functional groups. The mechanical properties (Young's modulus, elongation percent and tensile strength) of the grafted membranes also, have been investigated. As the grafting degree increases, the modulus also increases. Increasing the hydrophilicity of the membranes by chemical treatment enhances its mechanical properties. The thermal parameters of the grafted membranes such as δH m1 . δH m2 , and T rc have been also studied by using DSC

  6. Synthesis of acrylates and methacrylates from coal-derived syngas

    Energy Technology Data Exchange (ETDEWEB)

    Spivey, J.J.; Gogate, M.R.; Jang, B.W.L. [Bechtel, San Francisco, CA (United States)] [and others

    1995-12-31

    Acrylates and methacrylates are among the most widely used chemical intermediates in the world. One of the key chemicals of this type is methyl methacrylate. Of the 4 billion pounds produced each year, roughly 85% is made using the acetone-cyanohydrin process, which requires handling of large quantities of hydrogen cyanide and produces ammonium sulfate wastes that pose an environmental disposal challenge. The U.S. Department of Energy and Eastman Chemical Company are sharing the cost of research to develop an alternative process for the synthesis of methyl methacrylate from syngas. Research Triangle Institute is focusing on the synthesis and testing of active catalysts for the condensation reactions, and Bechtel is analyzing the costs to determine the competitiveness of several process alternatives. Results thus far show that the catalysts for the condensation of formaldehyde and the propionate are key to selectively producing the desired product, methacrylic acid, with a high yield. These condensation catalysts have both acid and base functions and the strength and distribution of these acid-base sites controls the product selectivity and yield.

  7. Acoustic Performance of Resilient Materials Using Acrylic Polymer Emulsion Resin.

    Science.gov (United States)

    Kim, Haseog; Park, Sangki; Lee, Seahyun

    2016-07-19

    There have been frequent cases of civil complaints and disputes in relation to floor impact noises over the years. To solve these issues, a substantial amount of sound resilient material is installed between the concrete slab and the foamed concrete during construction. A new place-type resilient material is made from cement, silica powder, sodium sulfate, expanded-polystyrene, anhydrite, fly ash, and acrylic polymer emulsion resin. Its physical characteristics such as density, compressive strength, dynamic stiffness, and remanent strain are analyzed to assess the acoustic performance of the material. The experimental results showed the density and the dynamic stiffness of the proposed resilient material is increased with proportional to the use of cement and silica powder due to the high contents of the raw materials. The remanent strain, related to the serviceability of a structure, is found to be inversely proportional to the density and strength. The amount of reduction in the heavyweight impact noise is significant in a material with high density, high strength, and low remanent strain. Finally, specimen no. R4, having the reduction level of 3 dB for impact ball and 1 dB for bang machine in the single number quantity level, respectively, is the best product to obtain overall acoustic performance.

  8. Acoustic Performance of Resilient Materials Using Acrylic Polymer Emulsion Resin

    Directory of Open Access Journals (Sweden)

    Haseog Kim

    2016-07-01

    Full Text Available There have been frequent cases of civil complaints and disputes in relation to floor impact noises over the years. To solve these issues, a substantial amount of sound resilient material is installed between the concrete slab and the foamed concrete during construction. A new place-type resilient material is made from cement, silica powder, sodium sulfate, expanded-polystyrene, anhydrite, fly ash, and acrylic polymer emulsion resin. Its physical characteristics such as density, compressive strength, dynamic stiffness, and remanent strain are analyzed to assess the acoustic performance of the material. The experimental results showed the density and the dynamic stiffness of the proposed resilient material is increased with proportional to the use of cement and silica powder due to the high contents of the raw materials. The remanent strain, related to the serviceability of a structure, is found to be inversely proportional to the density and strength. The amount of reduction in the heavyweight impact noise is significant in a material with high density, high strength, and low remanent strain. Finally, specimen no. R4, having the reduction level of 3 dB for impact ball and 1 dB for bang machine in the single number quantity level, respectively, is the best product to obtain overall acoustic performance.

  9. New poly(dimethylsiloxane)/poly(perfluorooctylethyl acrylate) block copolymers: structure and order across multiple length scales in thin films

    KAUST Repository

    Martinelli, Elisa; Galli, Giancarlo; Krishnan, Sitaraman; Paik, Marvin Y.; Ober, Christopher K.; Fischer, Daniel A.

    2011-01-01

    Three sets of a new class of low surface tension block copolymers were synthesized consisting of a poly(dimethylsiloxane) (PDMS) block and a poly(perfluorooctylethyl acrylate) (AF8) block. The polymers were prepared using a bromo-terminated PDMS macroinitiator, to which was attached an AF8 block grown using atom transfer radical polymerization (ATRP) in such a designed way that the molecular weight and composition of the two polymer blocks were regularly varied. The interplay of both the phase separated microstructure and the mesomorphic character of the fluorinated domains with their effect on surface structure was evaluated using a suite of analytical tools. Surfaces of spin-coated and thermally annealed films were assessed using a combination of X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) studies. Both atomic force microscopy (AFM) measurements and grazing incidence small angle X-ray scattering (GISAXS) studies were carried out to evaluate the microstructure of the thin films. Even in block copolymers in which the PDMS block was the majority component, a significant presence of the lower surface energy AF8 block was detected at the film surface. Moreover, the perfluorooctyl helices of the AF8 repeat units were highly oriented at the surface in an ordered, tilted smectic structure, which was compared with those of the bulk powder samples using wide-angle X-ray powder diffraction (WAXD) studies. © 2011 The Royal Society of Chemistry.

  10. Preparation and magnetic properties of polymer magnetic composites based on acrylate resin filled with nickel plating graphite nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yi, E-mail: zhangyi520love@yahoo.com.cn [Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi' an 710072 (China); Qi Shuhua; Zhang Fan; Yang Yongqing; Duan Guochen [Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi' an 710072 (China)

    2011-11-01

    Nickel plating graphite nanosheets (Ni/GNs) were prepared by electroless plating method using graphite nanosheets (GNs). Then a novel polymer magnetic composites based on acrylate pressure-sensitive adhesive (acrylate PSA) filled with Ni/GNs were fabricated by solution blend method. The Ni/GNs and acrylate PSA/Ni/GNs composites were characterized by scanning electron microscope (SEM)/energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscope (TEM). All results showed that relatively uniform and compact Ni layer is successfully coated onto GNs under the given conditions, furthermore, Ni/GNs are homogeneously dispersed in acrylate PSA. The VSM results showed that the saturation magnetization of acrylate PSA/Ni/GNs composites increases with an increasing content of Ni/GNs while the coercivity decreases with an increasing content of Ni/GNs. When the content of GNs is 20 wt%, acrylate PSA/Ni/GNs composites exhibites good mechanical properties.

  11. Preparation and magnetic properties of polymer magnetic composites based on acrylate resin filled with nickel plating graphite nanosheets

    International Nuclear Information System (INIS)

    Zhang Yi; Qi Shuhua; Zhang Fan; Yang Yongqing; Duan Guochen

    2011-01-01

    Nickel plating graphite nanosheets (Ni/GNs) were prepared by electroless plating method using graphite nanosheets (GNs). Then a novel polymer magnetic composites based on acrylate pressure-sensitive adhesive (acrylate PSA) filled with Ni/GNs were fabricated by solution blend method. The Ni/GNs and acrylate PSA/Ni/GNs composites were characterized by scanning electron microscope (SEM)/energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscope (TEM). All results showed that relatively uniform and compact Ni layer is successfully coated onto GNs under the given conditions, furthermore, Ni/GNs are homogeneously dispersed in acrylate PSA. The VSM results showed that the saturation magnetization of acrylate PSA/Ni/GNs composites increases with an increasing content of Ni/GNs while the coercivity decreases with an increasing content of Ni/GNs. When the content of GNs is 20 wt%, acrylate PSA/Ni/GNs composites exhibites good mechanical properties.

  12. Mild toxic anterior segment syndrome mimicking delayed onset toxic anterior segment syndrome after cataract surgery

    Directory of Open Access Journals (Sweden)

    Su-Na Lee

    2014-01-01

    Full Text Available Toxic anterior segment syndrome (TASS is an acute sterile postoperative anterior segment inflammation that may occur after anterior segment surgery. I report herein a case that developed mild TASS in one eye after bilateral uneventful cataract surgery, which was masked during early postoperative period under steroid eye drop and mimicking delayed onset TASS after switching to weaker steroid eye drop.

  13. Atom transfer radical polymerization of n-butyl acrylate catalyzed by atom transfer radical polymerization of n-butyl acrylate catalyzed by

    NARCIS (Netherlands)

    Zhang, H.; Linde, van der R.

    2002-01-01

    The homogeneous atom transfer radical polymerization (ATRP) of n-butyl acrylate with CuBr/N-(n-hexyl)-2-pyridylmethanimine as a catalyst and ethyl 2-bromoisobutyrate as an initiator was investigated. The kinetic plots of ln([M]0/[M]) versus the reaction time for the ATRP systems in different

  14. Novel spatula and dissector for safer deep anterior lamellar keratoplasty

    Directory of Open Access Journals (Sweden)

    Gustavo ,2,3 Bonfadini

    2014-10-01

    Full Text Available Objective: We describe a novel spatula and dissector to facilitate the big-bubble technique in deep anterior lamellar keratoplasty (DALK. Methods: A 29-year-old man who was diagnosed with bilateral keratoconus underwent deep anterior lamellar keratoplasty (DALK. After 350μm partial thickness incision of the recipient cornea, the Bonfadini dissector was inserted at the deepest point in the peripheral incision and could be advanced to the center of the cornea safely because of its "semi-sharp" tip. After achieving the big-bubble (BB separation of Descemet membrane (DM from the overlying stroma, the anterior stromal disc was removed. Viscoelastic material was placed on the stromal bed to prevent uncontrolled collapse and perforation of DM during the paracentesis blade incision into the BB. We could detect the safe opening of the BB using the Bonfadini dissector by the leakage of air bubbles into the viscoelastic material. After injecting viscoelastic material into the BB space, we inserted the Bonfadini spatula into the bigbubble safely because of its curved profile and blunt edges. The groove along the length of the Bonfadini spatula enables safe and efficient incision or the residual stromal tissue using the pointed end of a sharp blade while protecting the underlying DM. After removal of posterior stroma, the donor button was sutured with 16 interrupted 10-0 nylon sutures. Results: This technique and the use of the Bonfadini spatula and dissector facilitate exposure of Descemet membrane. Conclusion: The smooth Bonfadini DALK spatula and dissector facilitate safe and efficient completion of DALK surgery.

  15. At the edge of intonation

    DEFF Research Database (Denmark)

    Niebuhr, Oliver

    2012-01-01

    The paper is concerned with the 'edge of intonation' in a twofold sense. It focuses on utterance-final F0 movements and crosses the traditional segment-prosody divide by investigating the interplay of F0 and voiceless fricatives in speech production. An experiment was performed for German with four...

  16. Capillary Sharp Inner Edge Manufacturing

    Czech Academy of Sciences Publication Activity Database

    Hošek, Jan; Studenovský, K.; Najdek, D.

    2009-01-01

    Roč. 19, č. 35 (2009), s. 19-25 ISSN 1584-5982. [MECAHITECH 09 /1./. Bukurešť, 08.10.2009-09.10.2009] R&D Projects: GA AV ČR IAA200760905 Institutional research plan: CEZ:AV0Z20760514 Keywords : capillary * edge * manufacturing Subject RIV: JR - Other Machinery

  17. Development of edge effects around experimental ecosystem hotspots is affected by edge density and matrix type

    Science.gov (United States)

    Ecological edge effects are sensitive to landscape context. In particular, edge effects can be altered by matrix type and by the presence of other nearby edges. We experimentally altered patch configurations in an African savanna to determine how edge density and matrix type influence edge effect de...

  18. Anterior capsular rupture following blunt ocular injury

    Science.gov (United States)

    Gremida, Anas; Kassem, Iris; Traish, Aisha

    2011-01-01

    Summary A 10-year-old boy suffered a large, oblique anterior capsular tear following blunt injury to his right eye. The boy was followed daily for hyphema resolution and progressive traumatic cataract formation. After the hyphema had resolved, the lens was removed using an anterior approach and an intraocular lens was placed with excellent visual outcome. PMID:23362402

  19. Totally thrombosed giant anterior communicating artery aneurysm

    Directory of Open Access Journals (Sweden)

    V R Roopesh Kumar

    2015-01-01

    Full Text Available Giant anterior communicating artery aneurysmsarerare. Apatient presented with visual dysfunction, gait ataxia and urinary incontinence. MRI showed a giant suprasellar mass.At surgery, the lesion was identified as being an aneurysm arising from the anterior communicating artery.The difficulty in preoperative diagnosis and relevant literature are reviewed.

  20. Structural degradation of acrylic bone cements due to in vivo and simulated aging.

    Science.gov (United States)

    Hughes, Kerry F; Ries, Michael D; Pruitt, Lisa A

    2003-05-01

    Acrylic bone cement is the primary load-bearing material used for the attachment of orthopedic devices to adjoining bone. Degradation of acrylic-based cements in vivo results in a loss of structural integrity of the bone-cement-prosthesis interface and limits the longevity of cemented orthopedic implants. The purpose of this study is to investigate the effect of in vivo aging on the structure of the acrylic bone cement and to develop an in vitro artificial aging protocol that mimics the observed degradation. Three sets of retrievals are examined in this study: Palacos brand cement retrieved from hip replacements, and Simplex brand cement retrieved from both hip and knee replacement surgeries. In vitro aging is performed using oxidative and acidic environments on three acrylic-based cements: Palacos, Simplex, and CORE. Gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR) are used to examine the evolution of molecular weight and chemical species within the acrylic cements due to both in vivo and simulated aging. GPC analysis indicates that molecular weight is degraded in the hip retrievals but not in the knee retrievals. Artificial aging in an oxidative environment best reproduces this degradation mechanism. FTIR analysis indicates that there exists a chemical evolution within the cement due to in vivo and in vitro aging. These findings are consistent with scission-based degradation schemes in the cement. Based on the results of this study, a pathway for structural degradation of acrylic bone cement is proposed. The findings from this investigation have broad applicability to acrylic-based cements and may provide guidance for the development of new bone cements that resist degradation in the body. Copyright 2003 Wiley Periodicals, Inc.

  1. Computational study of chain transfer to monomer reactions in high-temperature polymerization of alkyl acrylates.

    Science.gov (United States)

    Moghadam, Nazanin; Liu, Shi; Srinivasan, Sriraj; Grady, Michael C; Soroush, Masoud; Rappe, Andrew M

    2013-03-28

    This article presents a computational study of chain transfer to monomer (CTM) reactions in self-initiated high-temperature homopolymerization of alkyl acrylates (methyl, ethyl, and n-butyl acrylate). Several mechanisms of CTM are studied. The effects of the length of live polymer chains and the type of monoradical that initiated the live polymer chains on the energy barriers and rate constants of the involved reaction steps are investigated theoretically. All calculations are carried out using density functional theory. Three types of hybrid functionals (B3LYP, X3LYP, and M06-2X) and four basis sets (6-31G(d), 6-31G(d,p), 6-311G(d), and 6-311G(d,p)) are applied to predict the molecular geometries of the reactants, products and transition sates, and energy barriers. Transition state theory is used to estimate rate constants. The results indicate that abstraction of a hydrogen atom (by live polymer chains) from the methyl group in methyl acrylate, the methylene group in ethyl acrylate, and methylene groups in n-butyl acrylate are the most likely mechanisms of CTM. Also, the rate constants of CTM reactions calculated using M06-2X are in good agreement with those estimated from polymer sample measurements using macroscopic mechanistic models. The rate constant values do not change significantly with the length of live polymer chains. Abstraction of a hydrogen atom by a tertiary radical has a higher energy barrier than abstraction by a secondary radical, which agrees with experimental findings. The calculated and experimental NMR spectra of dead polymer chains produced by CTM reactions are comparable. This theoretical/computational study reveals that CTM occurs most likely via hydrogen abstraction by live polymer chains from the methyl group of methyl acrylate and methylene group(s) of ethyl (n-butyl) acrylate.

  2. Atraumatic Anterior Dislocation of the Hip Joint

    Directory of Open Access Journals (Sweden)

    Tadahiko Ohtsuru

    2015-01-01

    Full Text Available Dislocation of the hip joint in adults is usually caused by high-energy trauma such as road traffic accidents or falls from heights. Posterior dislocation is observed in most cases. However, atraumatic anterior dislocation of the hip joint is extremely rare. We present a case of atraumatic anterior dislocation of the hip joint that was induced by an activity of daily living. The possible causes of this dislocation were anterior capsule insufficiency due to developmental dysplasia of the hip, posterior pelvic tilt following thoracolumbar kyphosis due to vertebral fracture, and acetabular anterior coverage changes by postural factor. Acetabular anterior coverage changes in the sagittal plane were measured using a tomosynthesis imaging system. This system was useful for elucidation of the dislocation mechanism in the present case.

  3. Long anterior zonules and pigment dispersion.

    Science.gov (United States)

    Moroi, Sayoko E; Lark, Kurt K; Sieving, Paul A; Nouri-Mahdavi, Kouros; Schlötzer-Schrehardt, Ursula; Katz, Gregory J; Ritch, Robert

    2003-12-01

    To describe pigment dispersion associated with long anterior zonules. Multicenter observational case series. Fifteen patients, seven of whom were treated for glaucoma or ocular hypertension, were identified with long anterior zonules and pigment dispersion. Transmission electron microscopy was performed on one anterior capsule specimen. All patients had anterior zonules that inserted centrally on the lens capsule. Signs of pigment dispersion included corneal endothelial pigmentation, loss of the pupillary ruff, and variable trabecular meshwork pigmentation. Ultrasound biomicroscopy verified the lack of posterior iris insertion and concavity. There was no exfoliation material. Transmission electron microscopy showed zonular lamellae with adherent pigment granules, and no exfoliation material. Long anterior zonules inserted onto the central lens capsule may cause mechanical disruption of the pigment epithelium at the pupillary ruff and central iris leading to pigment dispersion.

  4. Anterior capsulotomy using the CO2 laser

    Science.gov (United States)

    Barak, Adiel; Ma-Naim, Tova; Rosner, Mordechai; Eyal, Ophir; Belkin, Michael

    1998-06-01

    Continuous circular capsulorhexis (CCC) is the preferred technique for removal of the anterior capsule during cataract surgery due to this technique assuring accurate centration of the intraocular lens. During modern cataract surgery, especially with small or foldable intra ocular lenses, centration of the lens is obligatory. Radial tears at the margin of an anterior capsulotomy may be associated with the exit of at least one loop of an intraocular lens out of the capsular bag ('pea pod' effect) and its subsequent decentration. The anterior capsule is more likely to ream intact if the continuous circular capsulorhexis (CCC) technique is used. Although manual capsulorhexis is an ideal anterior capsulectomy technique for adults, many ophthalmologists are still uncomfortable with it and find it difficult to perform, especially in complicated cases such as these done behind small pupil, cataract extraction in children and pseudoexfoliation syndrome. We have developed a technique using a CO2 laser system for safe anterior capsulotomy and tested it in animal eyes.

  5. Anterior capsular staining with trypan blue for capsulorhexis in mature and hypermature cataracts. A preliminary study

    Directory of Open Access Journals (Sweden)

    Kothari Kulin

    2001-01-01

    Full Text Available Purpose: To study the efficacy and safety of 0.1% Trypan Blue dye to stain the anterior capsule for capsulorhexis in mature and hypermature cataracts. Methods: This preliminary study included 25 eyes of 25 patients with a unilateral mature or hypermature cataract, including one case of traumatic mature cataract. In all these cases 0.2ml of 0.1% trypan blue dye was used to stain the anterior capsule. The efficacy and safety of the dye was evaluated on the basis of intraoperative and postoperative observations. Results: In all 25 eyes the capsulorhexis was completed. There was peripheral extension of the capsulorhexis in the eye with traumatic cataract and the stained edge of the anterior capsule helped identification and redirection of the capsulorhexis. Successful phacoemulsification with intraocular lens implantation was performed in all eyes. Adverse reactions related to the dye such as raised intraocular pressure, anterior chamber inflammation and endothelial damage were not observed in the immediate postoperative period or at the end of mean follow-up of 3 months. Conclusion: Trypan blue dye staining of the anterior capsule appears to be a very useful and safe technique that simplifies capsulorhexis in mature and hypermature cataracts.

  6. Maxillary anterior en masse retraction using different antero-posterior position of mini screw: a 3D finite element study

    Directory of Open Access Journals (Sweden)

    Zohreh Hedayati

    2016-10-01

    Full Text Available Abstract Background Nowadays, mini screws are used in orthodontic tooth movement to obtain maximum or absolute anchorage. They have gained popularity among orthodontists for en masse retraction of anterior teeth after first premolar extraction in maximum anchorage cases. The purpose of this study was to determine the type of anterior tooth movement during the time when force was applied from different mini screw placements to the anterior power arm with various heights. Methods A finite element method was used for modeling maxillary teeth and bone structure. Brackets, wire, and hooks were also designed for modeling. Two appropriate positions for mini screw in the mesial and distal of the second premolar were designed as fixed nodes. Forces were applied from the mini screw to four different levels of anterior hook height: 0, 3, 6, and 9 mm. Initial tooth movement in eight different conditions was analyzed and calculated with ANSYS software. Results Rotation of anterior dentition was decreased with a longer anterior power arm and the mesial placement of the mini screw. Bodily movements occurred with the 9-mm height of the power arm in both mini screw positions. Intrusion or extrusion of the anterior teeth segment depended on the level of the mini screw and the edge of the power arm on the Z axis. Conclusions According to the findings of this study, the best control in the sagittal plane during anterior en masse retraction was achieved by mesial placement of the mini screw and the 9-mm height of the anterior power arm. Where control in the vertical plane was concerned, distal placement of the mini screw with the 6-mm power arm height had minimum adverse effect on anterior dentition.

  7. Pulse radiolysis of butyl acrylate in aqueous solution

    International Nuclear Information System (INIS)

    Kujawa, P.; Ulanski, P.; Rosiak, J.M.; Mohid, N.; Zaman, K.; Manshol, W.

    1998-01-01

    The pulse radiolysis of n-butyl acrylate (nBA) in aqueous solution was studied. The rate constant of the reaction of nBA with hydroxyl radicals was calculated as 1.5x10 10 dm 3 mol -1 s -1 . The absorption spectrum of the OH · -nBA adduct appeared to have a broad maximum at 300 nm. This spectrum was attributed to the α-carbon centred radicals. It decayed with the first-order rate constant k=1.5x10 4 s -1 (pH 10.8). The rate constant of the nBA reaction with hydrated electrons was determined as k=1.6x10 10 dm 3 mol -1 s -1 . The spectrum of H · -nBA adduct was similar to that recorded for OH · adduct. It decayed with first-order kinetics at k=1.0x10 4 s -1 . Spectra of the electron adduct were characterised by the band with a maximum at 285 nm (pH 10.0) or at 280 nm (pH 4.0) with ε=10500 dm 3 mol -1 cm -1 . In acidic solution, radical anion formed upon addition of hydrated electrons to the nBA molecule, undergoes fast, reversible protonation. The decay of the reversibly protonated electron adduct was a second-order process at k=2.5x10 9 dm 3 mol -1 s -1 . This reaction took place at the carbonyl oxygen. Slow, irreversible protonation of the electron adduct at high pH takes place at the β-carbon atom at k=2.9x10 4 s -1

  8. SET-LRP of the Hydrophobic Biobased Menthyl Acrylate.

    Science.gov (United States)

    Bensabeh, Nabil; Ronda, Joan C; Galià, Marina; Cádiz, Virginia; Lligadas, Gerard; Percec, Virgil

    2018-04-09

    Cu(0) wire-catalyzed single electron transfer-living radical polymerization (SET-LRP) of (-)-menthyl acrylate, a biobased hydrophobic monomer, was investigated at 25 °C in ethanol, isopropanol, ethyl lactate, 2,2,2-trifluoroethanol (TFE), and 2,2,3,3-tetrafluoropropanol (TFP). All solvents are known to promote, in the presence of N ligands, the mechanistically required self-regulated disproportionation of Cu(I)Br into Cu(0) and Cu(II)Br 2 . Both fluorinated alcohols brought out their characteristics of universal SET-LRP solvents and showed the proper polarity balance to mediate an efficient polymerization of this bulky and hydrophobic monomer. Together with the secondary alkyl halide initiator, methyl 2-bromopropionate (MBP), and the tris(2-dimethylaminoethyl)amine (Me 6 -TREN) ligand, TFE and TPF mediated an efficient SET-LRP of MnA at room temperature that proceeds through a self-generated biphasic system. The results presented here demonstrate that Cu(0) wire-catalyzed SET-LRP can be used to target polyMnA with different block lengths and narrow molecular weight distribution at room temperature. Indeed, the use of a combination of techniques that include GPC, 1 H NMR, MALDI-TOF MS performed before and after thioetherification of bromine terminus via "thio-bromo" click chemistry, and in situ reinitiation copolymerization experiments supports the near perfect chain end functionality of the synthesized biobased hydrophobic polymers. These results expand the possibilities of SET-LRP into the area of renewable resources where hydrophobic compounds are widespread.

  9. Edge-injective and edge-surjective vertex labellings

    DEFF Research Database (Denmark)

    Brandt, Stephan; Rautenbach, D.; Regen, F.

    2010-01-01

    For a graph G = (V, E) we consider vertex-k-labellings f : V → {1,2, ,k} for which the induced edge weighting w : E → {2, 3,., 2k} with w(uv) = f(u) + f(v) is injective or surjective or both. We study the relation between these labellings and the number theoretic notions of an additive basis and ...

  10. Generalized Multi-Edge Analysis for K-Edge Densitometry

    International Nuclear Information System (INIS)

    Collins, M.

    1998-01-01

    In K-edge densitometry (KED), a continuous-energy x-ray beam is transmitted through a liquid sample. The actinide content of the sample can be measured through analysis of the transmitted portion of the x-ray beam. Traditional methods for KED analysis allow the simultaneous calculation of, at most, two actinide concentrations. A generalized multi-edge KED analytical method is presented, allowing up to six actinide concentrations to be calculated simultaneously. Applications of this method for hybrid KED/x-ray fluorescence (HKED) systems are discussed. Current HKED systems require the operator to know the approximate actinide content of each sample, and manually select the proper analysis mode. The new multi-edge KED technique allows rapid identification of the major actinide components in a sample, independent of actinide content. The proper HKED analysis mode can be selected automatically, without requiring sample content information from the user. Automatic HKED analysis would be especially useful in an analytical laboratory setting, where samples with truly unknown characteristics are encountered. Because this technique requires no hardware modifications, several facilities that use HKED may eventually benefit from this approach

  11. Ultraviolet curing of acrylated liquid natural rubber for surface coating application

    Directory of Open Access Journals (Sweden)

    Kannikar Kwanming

    2009-01-01

    Full Text Available Ultraviolet curable acrylated liquid natural rubber was prepared by grafting of photosensitive molecule onto liquid natural rubber for surface coating application. The liquid natural rubber (LNR was firstly obtained by degradation of natural rubber latex with hydrogen peroxide and cobalt acetylacetonate at 65oC for 72 hrs. The preparation of acrylated natural rubber was carried out by the reaction of acrylic acid and epoxidized liquid natural rubber (ELNR prior obtained from LNR with formic acid and hydrogen peroxide in the ratio of 2:1 by weight in toluene at 80oC for 6, 9, 12, 18, and 24 hrs. It was found that the percentage of acrylate grafted onto liquid natural rubber depended on the reaction time. Surface coating was performed by using acrylated liquid natural rubber and 1,6-hexanediol diacrylate (HDDA or tripropylene glycol diacrylate (TPGDA as a crosslinker and Irgarcure 184 or Irgarcure 651 as a photoinitiator under UV exposure for 30, 60, and 90 seconds. The hardness test of cured products was investigated using the Pencil hardness test at pencil level of 2B to 6H. It was found that the highest hardness of surface coating was at pencil level of 4H for the product using TPGDA and Irgacure 651 in the ratio of 80:10 parts per hundred of rubber (phr. The cured products were able to resist to 2% H2SO4 and distilled water for more than 24 hrs.

  12. Direct Synthesis of Hyperbranched Poly(acrylic acid-co-3-hydroxypropionate

    Directory of Open Access Journals (Sweden)

    Efkan Çatıker

    2015-01-01

    Full Text Available Hyperbranched poly(acrylic acid-co-3-hydroxypropionate (PAcHP was synthesized by base-catalyzed hydrogen transfer polymerization of acrylic acid through one step. The copolymers obtained through solution and bulk polymerization were insoluble in water and all organic solvents tried. Structural and compositional characterizations of hyperbranched PAcHP were performed by using FTIR, solid 13C-NMR, TGA, and titrimetric analysis. Acrylate fraction of the hyperbranched PAcHP obtained via bulk polymerization was determined as 60–65% by comparing TGA curves of hyperbranched PAcHP and pure poly(3-hydroxy propionate (PHP. However, analytical titration of the same sample revealed that acrylic acid units were about 47.3%. The results obtained from TGA and analytical titration were used to evaluate the chemical structure of the copolymer. Hyperbranched PAcHP exhibited hydrogel properties. Swelling behavior of the copolymer was investigated at a wide pH range and ionic strength. The dynamic swelling profiles of hyperbranched PAcHP exhibited a fast swelling behavior in the first hour and achieved the equilibrium state within 12 h in PBS. Depending on the conditions, the copolymers exhibited swelling ratios up to 2100%. As the copolymer has easily biodegradable propionate and versatile functional acrylic acid units, it can be used as not only biodegradable material in medical applications but also raw material in personal care commodities.

  13. Cast Partial Denture versus Acrylic Partial Denture for Replacement of Missing Teeth in Partially Edentulous Patients

    Directory of Open Access Journals (Sweden)

    Pramita Suwal

    2017-03-01

    Full Text Available Aim: To compare the effects of cast partial denture with conventional all acrylic denture in respect to retention, stability, masticatory efficiency, comfort and periodontal health of abutments. Methods: 50 adult partially edentulous patient seeking for replacement of missing teeth having Kennedy class I and II arches with or without modification areas were selected for the study. Group-A was treated with cast partial denture and Group-B with acrylic partial denture. Data collected during follow-up visit of 3 months, 6 months, and 1 year by evaluating retention, stability, masticatory efficiency, comfort, periodontal health of abutment. Results: Chi-square test was applied to find out differences between the groups at 95% confidence interval where p = 0.05. One year comparison shows that cast partial denture maintained retention and stability better than acrylic partial denture (p< 0.05. The masticatory efficiency was significantly compromising from 3rd month to 1 year in all acrylic partial denture groups (p< 0.05. The comfort of patient with cast partial denture was maintained better during the observation period (p< 0.05. Periodontal health of abutment was gradually deteriorated in all acrylic denture group (p

  14. [Hydrogen peroxide, chloramine T and chlorhexidrine in the disinfection of acrylic resin].

    Science.gov (United States)

    Czerwińska, W; Kedzia, A; Kałowski, M

    1978-01-01

    The effectiveness of 3% h drogen peroxide, 5% chloramine T and 0,5% chlorhexidine gluconate solutions in disinfection of acrylic resine plates massively infected with oral flora was analysed. The acrylic resine plates used for investigations, were infected in vitro with mixed salivary flora characterized by small numbers of yeast-like fungi (1st group), or great number of these microorganisms (2nd group). Infected plates were exposed to solutions of analysed disinfectants during various time periods. After rinsing or inactivation of disinfectant residues, acrylic plates were put into bacteriological medium and incubated during 7 days period in 37 degrees C. The results of this study indicated the effectiveness of acrylic plates disinfection to be dependent on used disinfectant, time of exposition, and microorganisms present on the surface of acrylic resine. The solutions of disinfectants were less active in the cases of plates infected with material containing great numbers of yeast-like microorganisms. Among analysed disinfectants 0,5% solution of chlorhexidine was characterized by most effective and rapid activity, whereas 3% solution of hydrogen peroxide was found to be the least effective.

  15. Environmental Impacts on the Strength Parameters of Mineral-Acrylic (PMMA/ATH Facade Panels

    Directory of Open Access Journals (Sweden)

    Aleksander Byrdy

    2015-01-01

    Full Text Available Composite mineral-acrylic panels consist in 80% of natural minerals produced from bauxite (aluminium hydroxides (ATH and in 20% from acrylic resin (polymethyl methacrylate (PMMA. This material due to high usability is widely used in interior finishes. Recently, the mineral-acrylic panels have been used as external claddings of buildings. So far, there are several dozen elevations realized worldwide. Due to the variability of the strength parameters of PMMA acrylic resins depending on the environmental influence, a number of tests on samples of mineral-acrylic panels to verify their suitability for use in climate conditions in Central Europe were performed. The studies determined the change of the material parameters after being subjected to aging process in conditions of high temperature, high relative humidity, freeze-thaw cycles, and UV radiation. In the studies parameters such as flexural strength and modulus of elasticity were measured at a reference temperature of 23°C. In raised and lowered temperatures only the tensile strength tests were conducted. Due to the lack of information in the available literature, the authors carried out tests of the temperature influence on the PMMA/ATH composite modulus of elasticity and flexural strength which is crucial in designing process.

  16. Surface morphology changes of acrylic resins during finishing and polishing phases

    Directory of Open Access Journals (Sweden)

    Glaucio Serra

    2013-12-01

    Full Text Available INTRODUCTION: The finishing and polishing phases are essential to improve smoothness and shining on the surface of acrylic resins used to make removable orthodontic appliances. A good surface finishing reduces roughness, which facilitates hygiene, prevents staining and provides greater comfort to the patients. OBJECTIVE: The aim of this paper was to analyze the changes on surface morphology of acrylic resins during finishing and polishing phases. METHODS: Thirty discs (10 mm in diameter and 5 mm in length were made with acrylic resin and randomly divided into ten groups. The control group did not receive any treatment while the other groups received gradual finishing and polishing. The last group received the entire finishing and polishing procedures. Surface morphology was qualitatively analyzed through scanning electron microscopy and quantitatively analyzed through a laser profilometer test. RESULTS: The acrylic resin surfaces without treatment showed bubbles which were not observed in the subsequent phases. Wearing out with multilaminated burs, finishing with wood sandpaper and finishing with water sandpaper resulted in surfaces with decreasing irregularities. The surfaces that were polished with pumice and with low abrasive liquids showed high superficial smoothness. CONCLUSION: Highly smooth acrylic resin surfaces can be obtained after mechanical finishing and polishing performed with multilaminated burs, wood sandpaper, water sandpaper, pumice and low abrasive liquids.

  17. Edge imaging in intense beams

    Directory of Open Access Journals (Sweden)

    S. Bernal

    2002-06-01

    Full Text Available The appearance of rings of charge observed near the edge of beams from high-perveance guns is described with a simple ray tracing technique inspired by the particle-core model. We illustrate the technique, which has no analog in light optics, with examples from experiments employing solenoid focusing of an electron beam. The rings of charge result from the combined effects of external focusing and space-charge forces acting on paraxial fringe particles with relatively large initial transverse velocities. The model is independent of the physical mechanisms responsible for the fringe particles. Furthermore, the focal length for edge imaging in a uniform focusing channel is derived using a linearized trajectory equation for the motion of fringe particles. Counterintuitively, the focal length decreases as the beam current increases.

  18. Nonreference Medical Image Edge Map Measure

    Directory of Open Access Journals (Sweden)

    Karen Panetta

    2014-01-01

    Full Text Available Edge detection is a key step in medical image processing. It is widely used to extract features, perform segmentation, and further assist in diagnosis. A poor quality edge map can result in false alarms and misses in cancer detection algorithms. Therefore, it is necessary to have a reliable edge measure to assist in selecting the optimal edge map. Existing reference based edge measures require a ground truth edge map to evaluate the similarity between the generated edge map and the ground truth. However, the ground truth images are not available for medical images. Therefore, a nonreference edge measure is ideal for medical image processing applications. In this paper, a nonreference reconstruction based edge map evaluation (NREM is proposed. The theoretical basis is that a good edge map keeps the structure and details of the original image thus would yield a good reconstructed image. The NREM is based on comparing the similarity between the reconstructed image with the original image using this concept. The edge measure is used for selecting the optimal edge detection algorithm and optimal parameters for the algorithm. Experimental results show that the quantitative evaluations given by the edge measure have good correlations with human visual analysis.

  19. Gyrosheath near the tokamak edge

    International Nuclear Information System (INIS)

    Hazeltine, R.D.; Xiao, H.; Valanju, P.M.

    1993-03-01

    A new model for the structure of the radial electric field profile in the edge during the H-mode is proposed. Charge separation caused by the difference between electron and ion gyromotion, or more importantly in a tokamak, the banana motion (halo effect) can self-consistently produce an electric dipole moment that causes the sheared radial electric field. The calculated results based on the model are consistent with D-III D and TEXTOR experimental results

  20. Anatomical evidence for the anterior plate fixation of sacroiliac joint.

    Science.gov (United States)

    Bai, Zhibiao; Gao, Shichang; Liu, Jia; Liang, Anlin; Yu, Weihua

    2018-01-01

    The iatrogenic injuries to the lumbar nerves during the fixation the sacroiliac (SI) joint fractures with anterior plates were often reported. No specific method had been reported to avoid it. This study was done to find a safer way of placing the anterior plates and screws for treating the sacroiliac (SI) joint fracture and/or dislocation. The research was performed using 8 male and 7 female normal corpse pelvic specimens preserved by 10% formalin solution. Try by measuring the horizontal distance from L4, L5 nerve roots to the sacroiliac joint and perpendicular distance from L4, L5 nerve roots to the ala sacralis, the length of L4, L5 nerve roots from intervertebral foramen to the edge of true pelvis, the diameter of L4, L5 nerve roots. The angles between the sacroiliac joint and sagittal plane were measured on the CT images. The horizontal distance between the lateral side of the anterior branches of L4, L5 nerve roots and the sacroiliac joint decreased gradually from the top to the bottom. The widest distances for L4,5 were 2.1 cm (range, 1.74-2.40) and 2.7 cm (range, 2.34-3.02 cm), respectively. The smallest distances for L4, 5 were 1.2 cm (range, 0.82-1.48 cm) and 1.5 cm (range, 1.08-1.74 cm), respectively. On CT images, the angle between the sacroiliac joint and sagittal plane was about 30°. If we use two anterior plates to fix the sacroiliac joint, It is recommended to place one plate on the superior one third part of the joint, with exposing medially no more than 2.5 cm and the other in the middle one third part of the joint, with elevating periosteum medially no more than 1.5 cm. The screws in the sacrum are advised to incline medially about 30° directing to the true pelvis. Copyright © 2017. Published by Elsevier B.V.

  1. Knife-edge seal for vacuum bagging

    Science.gov (United States)

    Rauschl, J. A.

    1980-01-01

    Cam actuated clamps pinch bagging material between long knife edge (mounted to clamps) and high temperature rubber cushion bonded to baseplate. No adhesive, tape, or sealing groove is needed to seal edge of bagging sheet against base plate.

  2. Environmental Dataset Gateway (EDG) REST Interface

    Data.gov (United States)

    U.S. Environmental Protection Agency — Use the Environmental Dataset Gateway (EDG) to find and access EPA's environmental resources. Many options are available for easily reusing EDG content in other...

  3. Organizing on the Edge: Appreciation and Critique

    National Research Council Canada - National Science Library

    Scott, W. R

    2006-01-01

    .... Hayes, "Power to the Edge: Command, Control in the Information Age" (2003). The author places the "edge" perspective in the broader context of organizational studies, noting both its strengths and limitations...

  4. Edge effect on weevils and spiders

    Directory of Open Access Journals (Sweden)

    R. Horváth

    2002-05-01

    Full Text Available The edge effect on weevils and spiders was tested along oak forest – meadow transects using sweep-net samples at the Síkfökút Project in Hungary. For spiders the species richness was significantly higher in the forest edge than either in the meadow or the forest interior. For weevils the species richness of the forest edge was higher than that of the meadow, but the difference was not statistically significant whereas the species richness of the forest interior was significantly lower than that of the forest edge and the meadow. The composition of the spider assemblage of the edge was more similar to the forest, while the composition of weevils in the edge was more similar to the meadow. Our results based on two invertebrate groups operating on different trophic levels suggest that there is a significant edge effect for the studied taxa resulting in higher species richness in the edge.

  5. Synthesis of acrylated palm oil nanoparticles using microemulsion polymerization initiated by gamma ray

    International Nuclear Information System (INIS)

    Rida Tajau; Wan Md Zin Wan Yunus; Khairul Zaman Mohd Dahlan; Mohd Hilmi Mahmood; Kamaruddin Hashim; Sim, Flora; Sharila Muhd Faizal

    2010-01-01

    The use of microemulsion in the development of nanoparticle based on acrylated palm oil product is demonstrated. The microemulsion polymerization was initiated by gamma ray for synthesizing crosslinked nanoparticle. Polymerization of acrylated palm oil in three-component ionic microemulsions was prepared with sodium dodecyl sulphate (SDS) and water. The resulted nanoparticle, before and after initiated by gamma ray, were evaluated in terms of particle diameter, surface charge and molecular structure. Type and concentration of surfactants, monomer concentration, radiation dose and time of storage strongly affected the size, charge and size stability of the particles. For the development of new microscopic polymer acrylated palm oil can be synthesized into nano sized particle and it has potential to be developed in medical devices and controlled-drug-release-applications. (author)

  6. Radiation Induced Grafting of Acrylate onto Waste Rubber: The Effect of Monomer Type

    Directory of Open Access Journals (Sweden)

    Shirajuddin Siti Salwa M.

    2017-01-01

    Full Text Available The effect of three different acrylate group monomers, namely n-butyl acrylate, methacrylic acid and tripropylene glycol diacrylate of radiation induced grafting onto waste rubber was studied. The electron beam accelerator operated at voltage of 2MeV was used to irradiate the waste rubber at 10 kGy and 100 kGy absorbed radiation dose, respectively. The formation of grafting was observed from the increase in the grafting yield and confirmed by Transformed Infra-Red Spectroscopy results. According to the result obtained, only tripropylene glycol diacrylate was selected to graft onto waste rubber. The carbonyl bond from acrylate groups was seen at 1726 cm-1 band which confirmed the presence of TPGDA in the polymer matrix. This indicates the successful preparation of the TPGDA-grafted waste rubber via radiation induced grafting techniques.

  7. Effects of acrylamide and acrylic acid on creatine kinase activity in the rat brain

    International Nuclear Information System (INIS)

    Kohriyama, Kazuaki; Matsuoka, Masato; Igisu, Hideki

    1994-01-01

    In vitro, both acrylamide and acrylic acid inhibited creatine kinase (CK) activity in rat brain homogenates, and acrylic acid was more potent than acrylamide. In vivo, however, when given i.p. 50 mg/kg per day for 8 days to rats, only acrylamide inhibited CK activity in the brain and caused apparent neurological signs. 14 C in the brain 24 h after the injection of 14 C-labelled chemicals was more than 7 times greater with acrylamide than with acrylic acid. The inhibition of CK activity by acrylamide varied in eight regions of the brain; from 54% in hypothalamus to 27% in cerebellar vermis. The regional difference of CK inhibition, however, did not agree well with either 14 C distribution or with the distribution in regions which appear clinically or pathologically vulnerable to acrylamide. (orig.)

  8. Investigation of UV curing reaction of dicyclopentadienyl acrylate by FT-IR

    International Nuclear Information System (INIS)

    Lu Qiting; Hou Yibin

    1999-01-01

    Dicyclopentadienyl acrylate (DCPA) is characterized by low odor, low volatility, high flash point, low toxicity and low shrinkage on cure. Another advantage of DCPA is its insensitiveness to the inhibiting effect of oxygen. DCPA have wide industrial applications. It was used for the preparation of adhesives, UV-curable coatings and polymer concreted). The advantages of DCPA result from its particular structure. There are two unsaturated bonds, one acrylic double bond and one cyclic double bond, in each DCPA molecule. But, few reports on reaction behavior of the two type double bonds were issued up to date. In this paper, reaction behavior of the acrylic and the cyclic double bond of DCPA during and after LTV-curing were investigated by Fourier Transform-Infrared(FT-IR)

  9. Applications of Blue Light-curing Acrylic Resin to Forensic Sample Preparation and Microtomy.

    Science.gov (United States)

    Groves, Ethan; Palenik, Christopher S

    2016-03-01

    This study discusses the results of an evaluation of a one-part blue light-curing acrylic resin for embedding trace evidence prior to the preparation of thin sections with a microtome. Through a comparison to several epoxy resins, the physical properties relevant to both trace evidence examination and analytical microscopy in general, including as viscosity, clarity, color, hardness, and cure speed, were explored. Finally, thin sections from paint samples embedded in this acrylic resin were evaluated to determine if, through smearing or impregnation, the resin contributed to the infrared spectra. The results of this study show that blue light-curing acrylic resins provide the desired properties of an embedding medium, generate high-quality thin sections, and can significantly simplify the preparation of paint chips, fibers and a multitude of other types of microscopic samples in the forensic trace evidence laboratory. © 2015 American Academy of Forensic Sciences.

  10. High-impact strength acrylic denture base material processed by autoclave.

    Science.gov (United States)

    Abdulwahhab, Salwan Sami

    2013-10-01

    To investigate the effect of two different cycles of autoclave processing on the transverse strength, impact strength, surface hardness and the porosity of high-impact strength acrylic denture base material. High Impact Acryl was the heat-cured acrylic denture base material included in the study. A total of 120 specimens were prepared, the specimens were grouped into: control groups in which high-impact strength acrylic resins processed by conventional water-bath processing technique (74°C for 1.5 h then boil for 30 min) and experimental groups in which high-impact strength acrylic resins processed by autoclave at 121°C, 210 kPa .The experimental groups were divided into (fast) groups for 15 min, and (slow) groups for 30 min. To study the effect of the autoclave processing (Tuttnauer 2540EA), four tests were conducted transverse strength (Instron universal testing machine), impact strength (Charpy tester), surface hardness (shore D), and porosity test. The results were analyzed to ANOVA and LSD test. In ANOVA test, there were highly significant differences between the results of the processing techniques in transverse, impact, hardness, and porosity test. The LSD test showed a significant difference between control and fast groups in transverse and hardness tests and a non-significant difference in impact test and a highly significant difference in porosity test; while, there were a highly significant differences between control and slow groups in all examined tests; finally, there were a non-significant difference between fast and slow groups in transverse and porosity tests and a highly significant difference in impact and hardness tests. In the autoclave processing technique, the slow (long) curing cycle improved the tested physical and mechanical properties as compared with the fast (short) curing cycle. The autoclave processing technique improved the tested physical and mechanical properties of High Impact Acryl. Copyright © 2013 Japan Prosthodontic Society

  11. Cytotoxicity Evaluation of Two Bis-Acryl Composite Resins Using Human Gingival Fibroblasts.

    Science.gov (United States)

    Gonçalves, Fabiano Palmeira; Alves, Gutemberg; Guimarães, Vladi Oliveira; Gallito, Marco Antônio; Oliveira, Felipe; Scelza, Míriam Zaccaro

    2016-01-01

    Bis-acryl resins are used for temporary dental restorations and have shown advantages over other materials. The aim of this work was to evaluate the in vitro cytotoxicity of two bis-acryl composite resins (Protemp 4 and Luxatemp Star), obtained at 1, 7 and 40 days after mixing the resin components, using a standardized assay employing human primary cells closely related to oral tissues. Human gingival fibroblast cell cultures were exposed for 24 h to either bis-acryl composite resins, polystyrene beads (negative control) and latex (positive control) extracts obtained after incubation by the different periods, at 37 °C under 5% CO2. Cell viability was evaluated using a multiparametric procedure involving sequential assessment (using the same cells) of mitochondrial activity (XTT assay), membrane integrity (neutral red test) and total cell density (crystal violet dye exclusion test). The cells exposed to the resin extracts showed cell viability indexes exceeding 75% after 24 h. Even when cells were exposed to extracts prepared with longer conditioning times, the bis-acryl composite resins showed no significant cytotoxic effects (p>0.05), compared to the control group or in relation to the first 24 h of contact with the products. There were no differences among the results obtained for the bis-acryl composite resins evaluated 24 h, 7 days and 40 days after mixing. It may be concluded that the bis-acryl resins Protemp 4 and Luxatemp Star were cytocompatible with human gingival fibroblasts, suggesting that both materials are suitable for use in contact with human tissues.

  12. Do patients prefer mesh or anterior colporrhaphy for primary correction of anterior vaginal wall prolapse: a labelled discrete choice experiment

    NARCIS (Netherlands)

    Notten, K. J. B.; Essers, B. A.; Weemhoff, M.; Rutten, A. G. H.; Donners, J. J. A. E.; van Gestel, I.; Kruitwagen, R. F. M. P.; Roovers, J. P. W. R.; Dirksen, C. D.

    2015-01-01

    We investigated patients' preferences for anterior colporrhaphy or mesh surgery as surgical correction of anterior vaginal wall prolapse. Labelled discrete choice experiment. Three Dutch teaching hospitals. Women with anterior vaginal wall prolapse Pelvic Organ Prolapse Quantification stage 2 or

  13. CFAR Edge Detector for Polarimetric SAR Images

    DEFF Research Database (Denmark)

    Schou, Jesper; Skriver, Henning; Nielsen, Allan Aasbjerg

    2003-01-01

    Finding the edges between different regions in an image is one of the fundamental steps of image analysis, and several edge detectors suitable for the special statistics of synthetic aperture radar (SAR) intensity images have previously been developed. In this paper, a new edge detector for polar...

  14. Energetics of highly kinked step edges

    NARCIS (Netherlands)

    Zandvliet, Henricus J.W.

    2010-01-01

    We have determined the step edge free energy, the step edge stiffness and dimensionless inverse step edge stiffness of the highly kinked < 010> oriented step on a (001) surface of a simple square lattice within the framework of a solid-on-solid model. We have found an exact expression for the step

  15. Acyclicity in edge-colored graphs

    DEFF Research Database (Denmark)

    Gutin, Gregory; Jones, Mark; Sheng, Bin

    2017-01-01

    A walk W in edge-colored graphs is called properly colored (PC) if every pair of consecutive edges in W is of different color. We introduce and study five types of PC acyclicity in edge-colored graphs such that graphs of PC acyclicity of type i is a proper superset of graphs of acyclicity of type...

  16. MRI of tibialis anterior tendon rupture

    International Nuclear Information System (INIS)

    Gallo, Robert A.; DeMeo, Patrick J.; Kolman, Brett H.; Daffner, Richard H.; Sciulli, Robert L.; Roberts, Catherine C.

    2004-01-01

    Ruptures of the tibialis anterior tendon are rare. We present the clinical histories and MRI findings of three recent male patients with tibialis anterior tendon rupture aged 58-67 years, all of whom presented with pain over the dorsum of the ankle. Two of the three patients presented with complete rupture showing discontinuity of the tendon, thickening of the retracted portion of the tendon, and excess fluid in the tendon sheath. One patient demonstrated a partial tear showing an attenuated tendon with increased surrounding fluid. Although rupture of the tibialis anterior tendon is a rarely reported entity, MRI is a useful modality in the definitive detection and characterization of tibialis anterior tendon ruptures. (orig.)

  17. Anterior pseudoarthrectomy for symptomatic Bertolotti's syndrome.

    Science.gov (United States)

    Malham, Gregory M; Limb, Rebecca J; Claydon, Matthew H; Brazenor, Graeme A

    2013-12-01

    Painful L5/S1 pseudoarthrosis has been previously managed with posterior excision and/or lumbar fusion. To our knowledge, the anterior approach for L5/S1 pseudoarthrectomy in the treatment of Bertolotti's syndrome has not been described. We present two patients with severe symptomatic L5/S1 pseudoarthroses that were successfully excised via an anterior retroperitoneal approach with 2 year clinical and radiological follow-up. The literature regarding surgical treatments for Bertolotti's syndrome is reviewed. The technique for an anterior retroperitoneal approach is described. This approach has been safe and effective in providing long term symptomatic relief to our two patients. Further studies comparing the outcomes of anterior versus posterior pseudoarthrectomy will guide the management of this condition. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. In vitro evaluation of fracture resistance of Fiber-Reinforced Composite inlay bridges in upper anterior and lower posterior teeth

    Directory of Open Access Journals (Sweden)

    Jalalian E.

    2007-07-01

    Full Text Available Background and Aim: Considering flexural strength of fiber-reinforced composites (FRC and also the role of conservative cavities in protecting sound tissue of abutments, the aim of this study was to evaluate the fracture resistance of these bridges by handmade samples in vitro.Materials and Methods: In this experimental in vitro study, 44 sound newly extracted teeth were used to make 22 fixed inlay bridges including 11 three unit anterior upper inlay bridges substituting clinical model of upper central and 11 three unit posterior lower inlay bridges substituting clinical model of lower first molar. Specimens were prepared with FRC and mounted with artificial PDL in acryl. Cases were exposed to final load by using Universal Testing Machine (Instron 1195 with the speed of 1 mm/min. Statistical analysis was performed by Kolmogorov- Smirnov, independent sample T and Kaplan-Meier tests with p<0.05 as the level of significance.Results: Based on the statistical tests, the 95% confidence interval of mean was 450-562 N in anterior and  1473- 1761 N in posterior area. Fracture strength was high in the studied groups. Fractures in both groups occurred on composite facing, and the framework remained intact. The highest percentage of fracture in posterior teeth was in the middle of pontic towards the distal connector and in the anterior teeth in the lateral connector, between central pontic and lateral abutment. Using the independent sample T  test a significant statistical difference was observed between two groups (P<0.001. The fracture resistance of anterior samples was lower than the posterior ones.Conclusion: Based on the results of this study regarding the high fracture resistance in both areas FRC inlay bridges could be recommended for upper anterior and lower posterior teeth in clinical dentistry certainly more studies are needed to ascertain this treatment option.

  19. Analysis of femtosecond laser assisted capsulotomy cutting edges and manual capsulorhexis using environmental scanning electron microscopy.

    Science.gov (United States)

    Serrao, Sebastiano; Lombardo, Giuseppe; Desiderio, Giovanni; Buratto, Lucio; Schiano-Lomoriello, Domenico; Pileri, Marco; Lombardo, Marco

    2014-01-01

    Purpose. To investigate the structure and irregularity of the capsulotomy cutting edges created by two femtosecond (FS) laser platforms in comparison with manual continuous circular capsulorhexis (CCC) using environmental scanning electron microscopy (eSEM). Methods. Ten anterior capsulotomies were obtained using two different FS laser cataract platforms (LenSx, n = 5, and Victus, n = 5). In addition, five manual CCC (n = 5) were obtained using a rhexis forceps. The specimens were imaged by eSEM (FEI Quanta 400, OR, USA). Objective metrics, which included the arithmetic mean deviation of the surface (Sa) and the root-mean-square deviation of the surface (Sq), were used to evaluate the irregularity of both the FS laser capsulotomies and the manual CCC cutting edges. Results. Several microirregularities were shown across the FS laser capsulotomy cutting edges. The edges of manually torn capsules were shown, by comparison of Sa and Sq values, to be smoother (P < 0.05) than the FS laser capsulotomy edges. Conclusions. Work is needed to understand whether the FS laser capsulotomy edge microirregularities, not seen in manual CCC, may act as focal points for the concentration of stress that would increase the risk of capsular tear during phacoemulsification as recently reported in the literature.

  20. Analysis of Femtosecond Laser Assisted Capsulotomy Cutting Edges and Manual Capsulorhexis Using Environmental Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Sebastiano Serrao

    2014-01-01

    Full Text Available Purpose. To investigate the structure and irregularity of the capsulotomy cutting edges created by two femtosecond (FS laser platforms in comparison with manual continuous circular capsulorhexis (CCC using environmental scanning electron microscopy (eSEM. Methods. Ten anterior capsulotomies were obtained using two different FS laser cataract platforms (LenSx, n=5, and Victus, n=5. In addition, five manual CCC (n=5 were obtained using a rhexis forceps. The specimens were imaged by eSEM (FEI Quanta 400, OR, USA. Objective metrics, which included the arithmetic mean deviation of the surface (Sa and the root-mean-square deviation of the surface (Sq, were used to evaluate the irregularity of both the FS laser capsulotomies and the manual CCC cutting edges. Results. Several microirregularities were shown across the FS laser capsulotomy cutting edges. The edges of manually torn capsules were shown, by comparison of Sa and Sq values, to be smoother (P<0.05 than the FS laser capsulotomy edges. Conclusions. Work is needed to understand whether the FS laser capsulotomy edge microirregularities, not seen in manual CCC, may act as focal points for the concentration of stress that would increase the risk of capsular tear during phacoemulsification as recently reported in the literature.

  1. Electroactive behavior assessment of poly(acrylic acid)-graphene oxide composite hydrogel in the detection of cadmium

    NARCIS (Netherlands)

    Bejarano-Jimenez, A.; Escobar-Barrios, V.A.; Kleijn, J.M.; Oritz-Ledon, C.A.; Chazaro-Ruiz, L.F.

    2014-01-01

    Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous

  2. Deposition of indium tin oxide films on acrylic substrates by radiofrequency magnetron sputtering

    International Nuclear Information System (INIS)

    Chiou, B.S.; Hsieh, S.T.; Wu, W.F.

    1994-01-01

    Indium tin oxide (ITO) films were deposited onto acrylic substrates by rf magnetron sputtering. Low substrate temperature (< 80 C) and low rf power (< 28 W) were maintained during sputtering to prevent acrylic substrate deformation. The influence of sputtering parameters, such as rf power, target-to-substrate distance, and chamber pressure, on the film deposition rate, the electrical properties, as well as the optical properties of the deposited films was investigated. Both the refractive index and the extinction coefficient were derived. The high reflection at wavelengths greater than 3 μm made these sputtered ITO films applicable to infrared mirrors

  3. Self-Compacting Concrete Incorporating Micro-SiO2 and Acrylic Polymer

    Directory of Open Access Journals (Sweden)

    Ali Heidari

    2014-01-01

    Full Text Available This study examined the effects of using acrylic polymer and micro-SiO2 in self-compacting concrete (SCC. Using these materials in SCC improves the characteristics of the concrete. Self-compacting samples with 1-2% of a polymer and 10% micro-SiO2 were made. In all cases, compressive strength, water absorption, and self-compacting tests were done. The results show that adding acrylic polymer and micro-SiO2 does not have a significant negative effect on the mechanical properties of self-compacting concrete. In addition using these materials leads to improving them.

  4. Self-Compacting Concrete Incorporating Micro-SiO2 and Acrylic Polymer

    OpenAIRE

    Heidari, Ali; Zabihi, Marzieh

    2014-01-01

    This study examined the effects of using acrylic polymer and micro-SiO2 in self-compacting concrete (SCC). Using these materials in SCC improves the characteristics of the concrete. Self-compacting samples with 1-2% of a polymer and 10% micro-SiO2 were made. In all cases, compressive strength, water absorption, and self-compacting tests were done. The results show that adding acrylic polymer and micro-SiO2 does not have a significant negative effect on the mechanical properties of self-compa...

  5. Radioluminescence of polyester resin modified with acrylic acid and its salts

    Science.gov (United States)

    Szalińska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

    Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77 K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60Co radiation.

  6. Radioluminescence of polyester resin modified with acrylic acid and its salts

    International Nuclear Information System (INIS)

    Szalinska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

    1987-01-01

    Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60 Co radiation. (author)

  7. Synthesis of poly(N-isopropylacrylamide-co-acrylic acid) model compounds for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens; Christensen, Morten Lykkegaard; Scales, Peter

    2005-01-01

    rheometry indicates that the blocks of poly(acrylic acid) are placed on the surface of the microgels. The combination of these three results reveal that the microgels have a core mainly consisting of poly(N-isopropylacrylamide) and a diffuse/cloudy surface consisting mainly of poly(acrylic acid).   The core/shell......  Theoretical development within solid/liquid separation in colloidal systems is largely based on inorganic, low charged and incompressible particles. These do not reflect the properties in biosolid/organic systems. There is therefore a need for a development of colloidal and particles which mimic...

  8. Chemical Fixation of CO{sub 2} to Acrylates Using Low-Valent Molybdenum Sources

    Energy Technology Data Exchange (ETDEWEB)

    Bernskoetter, Wesley

    2013-09-30

    The kinetic, mechanistic, and reactivity experiments to access the viability and possible reaction design of coupling of carbon dioxide and ethylene at a zerovalent molybdenum for the production of acrylates are described. A general model of the reaction mechanism has been outlined, including assessment of the rate limiting step in the reaction. Kinetic and computational data have valuated the influence of a range of tridentate ligand platforms on the rate of coupling. An in situ reduction and acrylate formation activity screen protocol has also been developed to aid in the technology development of this process. Portions of descriptions of the research products presented here have also been adapted with permission from journal publications.

  9. Preparation of poly (vinyl alcohol) membranes grafted with n-vinyl pyridine/ acrylic acid binary monomers

    International Nuclear Information System (INIS)

    Ajji, A.; Ali, A.

    2014-03-01

    Poly(vinyl alcohol) films were grafted with two monomers using gamma radiation, acrylic acid and N-vinyl pyridine. The influence of different parameters on the grafting yield was investigated as: the comonomer concentration and composition, and irradiation dose. The suitable conditions of the process had been determined to prepare PVA membranes have both properties of the two monomers, acrylic acid and vinyl pyridine as comonomer concentration and composition, and irradiation dose. Some properties of the membranes had been investigated as maximum swelling and grafting. Also the ability of the grafted films to adsorb some heavy metals and dyes was elaborated and discussed.(author)

  10. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly(epsilon-caprolactone)-b-poly(acrylic acid)

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Hvilsted, Søren

    2009-01-01

    ) of tent-butyl acrylate (tBA) in a controlled fashion by use of NiBr2(PPh3)(2) catalyst to produce Prot-PCL-b-PtBA with narrow polydispersities (1.17-1.39). Subsequent mild deprotection protocols provided HS-PCL-b-PAA. Reduction of a gold salt in the presence of this macroligand under thiol......Amphiphilic poly(epsilon-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) with a thiol functionality in the PCL terminal has been prepared in a novel synthetic cascade. Initially, living anionic ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) employing the difunctional...

  11. Application of Functionalized SWCNTs for Increase of Degradation Resistance of Acrylic Paint for Cars

    Directory of Open Access Journals (Sweden)

    Osiel Lucas Flores

    2013-01-01

    Full Text Available Physical properties of automotive acrylic paint are improved by incorporation of three different types of carbon nanotubes: single-wall carbon nanotubes (SWCNTs, OH-functionalized single-wall carbon nanotubes (OH-SWCNTs, and aniline-functionalized single-wall carbon nanotubes (aniline-SWCNTs. The formed composites are studied by electron miscroscopy methods and Raman spectrometry. It is found that the acrylic paints with addition of OH-SWCNTs and aniline-SWCNTs show better quality for their applications. In particular, the resistance against degradation by electron beam increased in ~500%.

  12. Catalytic Cracking of Lactide and Poly(Lactic Acid) to Acrylic Acid at Low Temperatures.

    Science.gov (United States)

    Terrade, Frédéric G; van Krieken, Jan; Verkuijl, Bastiaan J V; Bouwman, Elisabeth

    2017-05-09

    Despite being a simple dehydration reaction, the industrially relevant conversion of lactic acid to acrylic acid is particularly challenging. For the first time, the catalytic cracking of lactide and poly(lactic acid) to acrylic acid under mild conditions is reported with up to 58 % yield. This transformation is catalyzed by strong acids in the presence of bromide or chloride salts and proceeds through simple S N 2 and elimination reactions. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  13. Synthesis, Characterization, and Aqueous Lubricating Properties of Amphiphilic Graft Copolymers Comprising 2-Methoxyethyl Acrylate

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Røn, Troels; Jankova Atanasova, Katja

    2014-01-01

    Amphiphilic anionic and cationic graft copolymers possessing poly(2-hydroxyethyl methacrylate) (PHEMA) backbone and poly(methacrylic acid), poly(2-methoxyethyl acrylate-co-methacrylic acid), and poly(2-methoxyethyl acrylate-co-2-(dimethylamino)ethyl methacrylate) grafts are constructed by merging...... of the corresponding monomers followed by deblocking reaction leads to well-defined amphiphiles with narrow molecular weight distributions (PDI ≤ 1.29) and varying content of methacrylic acid. The graft copolymers showed effective surface adsorption and lubrication for self-mated poly(dimethylsiloxane) (PDMS) contacts...

  14. Glycerol oxidehydration into acrolein and acrylic acid over W/V/Nb bronzes with hexagonal structure

    Energy Technology Data Exchange (ETDEWEB)

    Basile, F.; Cavani, F.; Chieregato, A. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali; CIRI Energia e Ambiente, Bologna (Italy); Concepcion, P.; Lopez Nieto, J.M.; Soriano, M.D. [Univ. Politecnica de Valencia (Spain). Inst. de Tecnologia Quimica; Liosi, G.; Trevisanut, C. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali

    2012-07-01

    This paper deals with an investigation of hexagonal W-V-Nb-O and W-V-Mo-O bronzes as catalysts for the one-pot oxidehydration of glycerol into acrylic acid. In a previous work, we reported a study on a bi-component bronze W-V-O that allowed us to obtain a 25% acrylic acid selectivity; in the current work, the incorporation of either Nb or Mo in a tri-component bronze structure allowed us to tune the acid and redox properties of the catalyst, so as to study their influence on the overall reaction scheme. (orig.)

  15. Acrylic kyphoplasty in recent nonosteoporotic fractures of the thoracolumbar junction: a prospective clinical and 3D radiologic study of 54 patients.

    Science.gov (United States)

    Saget, Mathieu; Teyssedou, Simon; Prebet, Remi; Vendeuvre, Tanguy; Gayet, Louis-Etienne; Pries, Pierre

    2014-08-01

    Prospective clinical and radiological study. To evaluate the impact of stand-alone acrylic kyphoplasty in the treatment of recent traumatic fractures of the thoracolumbar spine in young patients. The management of fractures of the thoracolumbar spine without neurological deficit remains controversial. For a long time clinicians could only chose between functional treatment, orthopedic treatment, and traditional surgery. The recent advent of minimally invasive surgical techniques is an interesting alternative. Fifty-four patients with a mean age of 45.8±18.2 years and who had recently sustained a fracture of the thoracolumbar junction were enrolled into the study. Balloon kyphoplasty was performed using acrylic cement. Radiologic assessments (computed tomography scans) and clinical assessments (including Visual Analog Scale and Oswestry Disability Index scores) were used to determine kyphoplasty success and measure patient recovery over 2 years. Kyphoplasty reduced mean vertebral kyphosis from 12.8±5.0 degrees at trauma to 8.2±5.1 degrees at 2-year follow-up. Mean vertebral kyphosis was corrected by -5.7±4.7 degrees (P=0.0001) at the point of first verticalization, with no significant change at the 2-year follow-up visit (+1.1±4.3 degrees, P=0.1058). Kyphoplasty significantly augmented the height of the 6 anterior and intermediate segments. Maximum mean augmentation of intermediate vertebral height after 6 months was (11.6%±15.5%, P<0.0001). Patients tolerated the procedure well and 56% of them returned to work 3 months after kyphoplasty. Kyphoplasty is safe and effective in the correction of nonosteoporotic fractures of the thoracolumbar junction in young patients, and remains stable for at least 2 years postsurgery.

  16. Long-Chain Diacrylate Crosslinkers and Use of PEG Crosslinks in Poly(potassium acrylate-acrylic acid/Kaolin Composite Superabsorbents

    Directory of Open Access Journals (Sweden)

    Koroush Kabiri

    2013-01-01

    Full Text Available Long-chain diacrylate crosslinkers based on linear α,ω-diols were synthesized and characterized using FTIR and 1H NMR spectroscopy. The highest reaction yield (99.5% was due to polyethylene glycol diacrylate 1000 (PEGDA-1000. Then, kaolin-containing poly(potassium acrylate-acrylic acid superabsorbent composites and kaolin-free counterparts were synthesized using PEGDA-1000.The effect of the crosslinker concentration on swelling, rheological and thermo-mechanical properties was investigated. Absorption capacity of the composite hydrogels (having ~38% kaolin was unexpectedly higher than that of kaolin-free hydrogels. This was attributed to an interfering effect of kaolin during the polymerization. Glass transition temperature was increased with crosslinker concentration enhancement and addition of kaolin up to about 10oC and 28oC, respectively. Making such K-containing superabsorbents may be taken as an effective action to achieve more durable and cheaper superabsorbents for agricultural uses.

  17. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid

    Directory of Open Access Journals (Sweden)

    Hongzhu Liu

    2017-01-01

    Full Text Available Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE, vinyl acetate (VAc, n-butyl acrylate (BA, Veova 10, and acrylic acid (AA. The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  18. Edge and coupled core/edge transport modelling in tokamaks

    International Nuclear Information System (INIS)

    Lodestro, L.L.; Casper, T.A.; Cohen, R.H.

    1999-01-01

    Recent advances in the theory and modelling of tokamak edge, scrape-off-layer (SOL) and divertor plasmas are described. The effects of the poloidal E x B drift on inner/outer divertor-plate asymmetries within a 1D analysis are shown to be in good agreement with experimental trends; above a critical v ExB , the model predicts transitions to supersonic flow at the inboard midplane. 2D simulations show the importance of E x B flow in the private-flux region and of ∇ B-drifts. A theory of rough plasma-facing surfaces is given, predicting modifications to the SOL plasma. The parametric dependence of detached-plasma states in slab geometry has been explored; with sufficient pumping, the location of the ionization front can be controlled; otherwise only fronts near the plate or the X-point are stable. Studies with a more accurate Monte-Carlo neutrals model and a detailed non-LTE radiation-transport code indicate various effects are important for quantitative modelling. Detailed simulations of the DIII-D core and edge are presented; impurity and plasma flow are discussed and shown to be well modelled with UEDGE. (author)

  19. Edge and coupled core-edge transport modelling in tokamaks

    International Nuclear Information System (INIS)

    Lodestro, L.L.; Casper, T.A.; Cohen, R.H.

    2001-01-01

    Recent advances in the theory and modelling of tokamak edge, scrape-off-layer (SOL) and divertor plasmas are described. The effects of the poloidal ExB drift on inner/outer divertor-plate asymmetries within a 1D analysis are shown to be in good agreement with experimental trends; above a critical v ExB, the model predicts transitions to supersonic SOL flow at the inboard midplane. 2D simulations show the importance of ExB flow in the private-flux region and of ∇ B-drifts. A theory of rough plasma-facing surfaces is given, predicting modifications to the SOL plasma. The parametric dependence of detached-plasma states in slab geometry has been explored; with sufficient pumping, the location of the ionization front can be controlled; otherwise only fronts near the plate or the X-point are stable. Studies with a more accurate Monte-Carlo neutrals model and a detailed non-LTE radiation-transport code indicate various effects are important for quantitative modelling. Detailed simulations of the DIII-D core and edge are presented; impurity and plasma flow are discussed and shown to be well modelled with UEDGE. (author)

  20. The role of sodium-poly(acrylates) with different weight-average molar mass in phosphate-free laundry detergent builder systems

    OpenAIRE

    Milojević, Vladimir S.; Ilić-Stojanović, Snežana; Nikolić, Ljubiša; Nikolić, Vesna; Stamenković, Jakov; Stojiljković, Dragan

    2013-01-01

    In this study, the synthesis of sodium-poly(acrylate) was performed by polymerization of acrylic acid in the water solution with three different contents of potassium-persulphate as an initiator. The obtained polymers were characterized by using HPLC and GPC analyses in order to define the purity and average molar mass of poly(acrylic acid). In order to investigate the influence of sodium-poly(acrylate) as a part of carbonate/zeolite detergent builder system, secondary washing characteristics...

  1. Preparation, Characterization and Permeation Behavior of Poly(methyl acrylate-Poly(dimethyl siloxane-Poly(methyl acrylate Block Copolymer/Poly(vinyl acetate Blend Membranes

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Semsarzadeh

    2015-03-01

    Full Text Available Structure of polymeric materials is of the most important factors in determination of the characteristics and properties of the membranes. Various research and developments on polymeric membranes confirm the direct correlation between structure-properties of polymeric membranes. In this research, the structural outcome of poly(methyl acrylate-poly(dimethyl siloxane-poly(methyl acrylate/poly(vinyl acetate blend membranes and its relationship with gas permeation behavior of the blends were investigated. The flexible block copolymer of poly(methyl acrylate-poly(dimethyl siloxane-poly(methyl acrylate (PMA-PDMS-PMA was synthesized via atom transfer radical polymerization. Morphology and chemical structure of the synthesized block copolymer was investigated by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, X-ray diffraction analysis, differential scanning calorimetry and scanning electron microscopy. Blend membranes of PMA-PDMS-PMA and poly(vinyl acetate (PVAc were prepared by solution casting method in different compositions. By adding poly(vinyl acetate to PMA-PDMS-PMA block copolymer, the selectivity of the membranes for carbon dioxide/methane pair gases were increased by 55%. Fractional free volume (an indication of chain packing efficiency in blend membranes and dielectric constant (an indication of the molar volume and molar polarization of the blend membranes were obtained as the factors reflected the microstructural effect of PMA-PDMS-PMA and PVAc blend membranes. The efforts were directed toward expressing more precise structure-properties relationship of PMA-PDMS-PMA/PVAc blend membranes. The experimental permeability values of the blend membranes reported in this research were compared with the modified logarithmic model. The modified logarithmic model was evaluated for other blend membranes.

  2. Mammographic x-ray unit kilovoltage test tool based on k-edge absorption effect.

    Science.gov (United States)

    Napolitano, Mary E; Trueblood, Jon H; Hertel, Nolan E; David, George

    2002-09-01

    A simple tool to determine the peak kilovoltage (kVp) of a mammographic x-ray unit has been designed. Tool design is based on comparing the effect of k-edge discontinuity of the attenuation coefficient for a series of element filters. Compatibility with the mammography accreditation phantom (MAP) to obtain a single quality control film is a second design objective. When the attenuation of a series of sequential elements is studied simultaneously, differences in the absorption characteristics due to the k-edge discontinuities are more evident. Specifically, when the incident photon energy is higher than the k-edge energy of a number of the elements and lower than the remainder, an inflection may be seen in the resulting attenuation data. The maximum energy of the incident photon spectra may be determined based on this inflection point for a series of element filters. Monte Carlo photon transport analysis was used to estimate the photon transmission probabilities for each of the sequential k-edge filter elements. The photon transmission corresponds directly to optical density recorded on mammographic x-ray film. To observe the inflection, the element filters chosen must have k-edge energies that span a range greater than the expected range of the end point energies to be determined. For the design, incident x-ray spectra ranging from 25 to 40 kVp were assumed to be from a molybdenum target. Over this range, the k-edge energy changes by approximately 1.5 keV between sequential elements. For this design 21 elements spanning an energy range from 20 to 50 keV were chosen. Optimum filter element thicknesses were calculated to maximize attenuation differences at the k-edge while maintaining optical densities between 0.10 and 3.00. Calculated relative transmission data show that the kVp could be determined to within +/-1 kV. To obtain experimental data, a phantom was constructed containing 21 different elements placed in an acrylic holder. MAP images were used to determine

  3. Mammographic x-ray unit kilovoltage test tool based on k-edge absorption effect

    International Nuclear Information System (INIS)

    Napolitano, Mary E.; Trueblood, Jon H.; Hertel, Nolan E.; David, George

    2002-01-01

    A simple tool to determine the peak kilovoltage (kVp) of a mammographic x-ray unit has been designed. Tool design is based on comparing the effect of k-edge discontinuity of the attenuation coefficient for a series of element filters. Compatibility with the mammography accreditation phantom (MAP) to obtain a single quality control film is a second design objective. When the attenuation of a series of sequential elements is studied simultaneously, differences in the absorption characteristics due to the k-edge discontinuities are more evident. Specifically, when the incident photon energy is higher than the k-edge energy of a number of the elements and lower than the remainder, an inflection may be seen in the resulting attenuation data. The maximum energy of the incident photon spectra may be determined based on this inflection point for a series of element filters. Monte Carlo photon transport analysis was used to estimate the photon transmission probabilities for each of the sequential k-edge filter elements. The photon transmission corresponds directly to optical density recorded on mammographic x-ray film. To observe the inflection, the element filters chosen must have k-edge energies that span a range greater than the expected range of the end point energies to be determined. For the design, incident x-ray spectra ranging from 25 to 40 kVp were assumed to be from a molybdenum target. Over this range, the k-edge energy changes by approximately 1.5 keV between sequential elements. For this design 21 elements spanning an energy range from 20 to 50 keV were chosen. Optimum filter element thicknesses were calculated to maximize attenuation differences at the k-edge while maintaining optical densities between 0.10 and 3.00. Calculated relative transmission data show that the kVp could be determined to within ±1 kV. To obtain experimental data, a phantom was constructed containing 21 different elements placed in an acrylic holder. MAP images were used to determine

  4. Tratamiento de la mordida cruzada anterior con plano inclinado anterior. Efecto sobre los arcos dentales

    OpenAIRE

    Carolina Rodríguez Manjarrés; Jesús Alberto Hernández Silva

    2017-01-01

    Objetivo: Evaluar los cambios dimensionales de los arcos dentales primarios tratados con plano inclinado anterior como método de corrección de la mordida cruzada anterior. Métodos: Se trataron 10 pacientes con edades entre 3 y 5 años afectados con mordida cruzada anterior completa, se colocó un plano inclinado anterior elaborado en acrílico, que estuvo en posición en promedio 8.5 semanas. Se obtuvieron modelos de estudio en 3 momentos T0: antes del tratamiento; T1: 6 meses después de iniciado...

  5. Image Edge Tracking via Ant Colony Optimization

    Science.gov (United States)

    Li, Ruowei; Wu, Hongkun; Liu, Shilong; Rahman, M. A.; Liu, Sanchi; Kwok, Ngai Ming

    2018-04-01

    A good edge plot should use continuous thin lines to describe the complete contour of the captured object. However, the detection of weak edges is a challenging task because of the associated low pixel intensities. Ant Colony Optimization (ACO) has been employed by many researchers to address this problem. The algorithm is a meta-heuristic method developed by mimicking the natural behaviour of ants. It uses iterative searches to find the optimal solution that cannot be found via traditional optimization approaches. In this work, ACO is employed to track and repair broken edges obtained via conventional Sobel edge detector to produced a result with more connected edges.

  6. K-edge densitometer (KED)

    Energy Technology Data Exchange (ETDEWEB)

    Sprinkle, J.K.; Hansen, W.J.

    1993-02-11

    In 1979, a K-edge densitometer (KED) was installed by the Safeguards Assay group from Los Alamos National Laboratory in the PNC reprocessing plant at Tokai-mura, Japan. It uses an active nondestructive assay technique, KED, to measure the plutonium concentration of the product solution. The measurement uncertainty of an assay depends on the count time chosen, but can be 0.5% or better. The computer hardware and software were upgraded in 1992. This manual describes the operation of the instrument, with an emphasis on the user interface to the software.

  7. Instant Adobe Edge Inspect starter

    CERN Document Server

    Khan, Joseph

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. This easy-to-understand Starter guide will get you up to speed with Adobe Edge Inspect quickly and with little effort.This book is for frontend web developers and designers who are developing and testing web applications targeted for mobile browsers. It's assumed that you have a basic understanding of creating web applications using HTML, CSS, and JavaScript, as well as being familiar with running web pages from local HTTP servers. Readers are a

  8. Homogeneous synthesis of cellulose acrylate-g-poly (n-alkyl acrylate) solid-solid phase change materials via free radical polymerization.

    Science.gov (United States)

    Qian, Yong-Qiang; Han, Na; Bo, Yi-Wen; Tan, Lin-Li; Zhang, Long-Fei; Zhang, Xing-Xiang

    2018-08-01

    A novel solid-solid phase change materials, namely, cellulose acrylate-g-poly (n-alkyl acrylate) (CA-g-PAn) (n = 14, 16 and 18) were successfully synthesized by free radical polymerization in N, N-dimethylacetamide (DMAc). The successful grafting was confirmed by fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (NMR). The properties of the CA-g-PAn copolymers were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The phase change temperatures and the melting enthalpies of CA-g-PAn copolymers are in the range of 10.1-53.2 °C and 15-95 J/g, respectively. It can be adjusted by the contents of poly (n-alkyl acrylate) and the length of alkyl side-chain. The thermal resistant temperatures of CA-g-PA14, 16 and 18 copolymers are 308 °C, 292 °C and 273 °C, respectively. It show that all of grafting materials exhibit good thermal stability and shape stability. Therefore, it is expected to be applied in the cellulose-based thermos-regulating field. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Effect of chemical composition on corneal tissue response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw

    2014-01-01

    The purpose of this work was to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and hydrogel material compatibility towards ocular anterior segment tissues, particularly the corneal endothelium. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Then, the 7-mm-diameter membrane implants made from photopolymerized materials were placed into the ocular anterior chamber for 4 days and assessed by biomicroscopic examinations, corneal thickness measurements, and quantitative real-time reverse transcription polymerase chain reaction analyses. The poly(HEMA-co-AAc) implants prepared from the solution mixture containing 0–10 vol.% AAc displayed good biocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the enhanced inflammatory response, decreased endothelial cell density, and increased ocular score and corneal thickness were observed, probably due to the influence of surface charge of copolymer membranes. On the other hand, the ionic pump function of corneal endothelium exposed to photopolymerized membranes was examined by analyzing the Na{sup +},K{sup +}-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of the implants having higher amount of AAc incorporated in the copolymers (i.e., 15.1 to 24.7 μmol) and zeta potential (i.e., -38.6 to − 56.5 mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal tissue responses to polymeric biomaterials. - Highlights: • We examine the corneal tissue responses to photopolymerized biomaterials. • Carboxyl groups in copolymers increased with increasing volume ratio of AAc/HEMA. • 15–20 vol.% AAc raised ocular score and caused corneal endothelial loss and edema. • High anionic charge density stimulated inflammation

  10. Characterisation of UV-cured acrylate networks by means of hydrolysis followed by aqueous size-exclusion combined with reversed-phase chromatography

    NARCIS (Netherlands)

    Peters, R.; Litvinov, V. M.; Steeman, P.; Dias, A. A.; Mengerink, Y.; van Benthem, R.; de Koster, C. G.; van der Wal, S. J.; Schoenmakers, P.

    2007-01-01

    UV-cured networks prepared from mixtures of di-functional (polyethylene-glycol di-acrylate) and mono-functional (2-ethylhexyl acrylate) acrylates were analysed after hydrolysis, by aqueous size-exclusion chromatography coupled to on-line reversed-phase liquid-chromatography. The mean network density

  11. The mean visible labial length of maxillary and mandibular anterior teeth at rest

    International Nuclear Information System (INIS)

    Khan, F.; Abbas, M.

    2014-01-01

    To determine the mean visible labial length of maxillary and mandibular anterior teeth at rest. Study Design: Cross-sectional study. Place and Duration of Study: Department of Prosthodontics, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Karachi, from October 2012 to March 2013. Methodology: A total of 200 subjects were included. Measurements were carried out using digital caliper from the border of the lip to the incisal edges of incisor and to the cusp tip for the canines. The length of the upper lip was measured from subnasale to stomion. Statistical analyses were performed by Mann Whitney-U test and Kruskal Walli's test. Results: The age of the participant ranged between 20 and 65 years. At rest, females significantly displayed more of the maxillary central incisor (2.93 +- 1.57 mm; p=0.003), lateral incisor (1.87 +- 1.12 mm; p=0.005) and canine (0.59 +- 0.62 mm; p=0.031). With increasing age, the amount of maxillary anterior teeth visible at rest significantly decreased (p < 0.001), and increased for the mandibular teeth (p < 0.001). Subjects with shorter upper lips significantly displayed more maxillary anterior incisor structure than subjects with longer upper lip (p < 0.001). Conclusion: Females displayed significantly more labial length of the maxillary anterior teeth. The mean visible labial length of maxillary anterior teeth significantly decreased with increasing age and increased for the mandibular teeth. As the upper lip length increased, the mean visible labial length of maxillary anterior teeth significantly decreased. (author)

  12. How Forest Inhomogeneities Affect the Edge Flow

    DEFF Research Database (Denmark)

    Boudreault, Louis-Étienne; Dupont, Sylvain; Bechmann, Andreas

    2016-01-01

    Most of our knowledge on forest-edge flows comes from numerical and wind-tunnel experiments where canopies are horizontally homogeneous. To investigate the impact of tree-scale heterogeneities (>1 m) on the edge-flow dynamics, the flow in an inhomogeneous forest edge on Falster island in Denmark...... is investigated using large-eddy simulation. The three-dimensional forest structure is prescribed in the model using high resolution helicopter-based lidar scans. After evaluating the simulation against wind measurements upwind and downwind of the forest leading edge, the flow dynamics are compared between...... the scanned forest and an equivalent homogeneous forest. The simulations reveal that forest inhomogeneities facilitate flow penetration into the canopy from the edge, inducing important dispersive fluxes in the edge region as a consequence of the flow spatial variability. Further downstream from the edge...

  13. Energetics of edge oxidization of graphene nanoribbons

    Science.gov (United States)

    Yasuma, Airi; Yamanaka, Ayaka; Okada, Susumu

    2018-06-01

    On the basis of the density functional theory, we studied the geometries and energetics of O atoms adsorbed on graphene edges for simulating the initial stage of the edge oxidization of graphene. Our calculations showed that oxygen atoms are preferentially adsorbed onto the graphene edges with the zigzag portion, resulting in a large adsorption energy of about 5 eV. On the other hand, the edges with armchair shape are rarely oxidized, or the oxidization causes substantial structural reconstructions, because of the stable covalent bond at the armchair edge with the triple bond nature. Furthermore, the energetics sensitively depends on the edge angles owing to the inhomogeneity of the charge density at the edge atomic sites.

  14. Haptic Edge Detection Through Shear

    Science.gov (United States)

    Platkiewicz, Jonathan; Lipson, Hod; Hayward, Vincent

    2016-03-01

    Most tactile sensors are based on the assumption that touch depends on measuring pressure. However, the pressure distribution at the surface of a tactile sensor cannot be acquired directly and must be inferred from the deformation field induced by the touched object in the sensor medium. Currently, there is no consensus as to which components of strain are most informative for tactile sensing. Here, we propose that shape-related tactile information is more suitably recovered from shear strain than normal strain. Based on a contact mechanics analysis, we demonstrate that the elastic behavior of a haptic probe provides a robust edge detection mechanism when shear strain is sensed. We used a jamming-based robot gripper as a tactile sensor to empirically validate that shear strain processing gives accurate edge information that is invariant to changes in pressure, as predicted by the contact mechanics study. This result has implications for the design of effective tactile sensors as well as for the understanding of the early somatosensory processing in mammals.

  15. Assessment of surface hardness of acrylic resins submitted to accelerated artificial aging.

    Science.gov (United States)

    Tornavoi, D C; Agnelli, J A M; Lepri, C P; Mazzetto, M O; Botelho, A L; Soares, R G; Dos Reis, A C

    2012-06-01

    The aim of this study was to assess the influence of accelerated artificial aging (AAA) on the surface hardness of acrylic resins. The following three commercial brands of acrylic resins were tested: Vipi Flash (autopolymerized resin), Vipi Wave (microwave heat-polymerized resin) and Vipi Cril (conventional heat-polymerized resin). To perform the tests, 21 test specimens (65x10x3 mm) were made, 7 for each resin. Three surface hardness readings were performed for each test specimen, before and after AAA, and the means were submitted to the following tests: Kolmogorov-Smirnov (P>0.05), Levene Statistic, Two-way ANOVA, Tukey Post Hoc (Paging, the autopolymerized acrylic resin Vipi Flash showed lower hardness values when compared with the heat-polymerized resin Vipi Cril (P=0.001). After aging, the 3 materials showed similar performance when compared among them. The Vipi Cril was the only one affected by AAA and showed lower hardness values after this procedure (Pp=0.003). It may be concluded that accelerated artificial aging influenced surface hardness of heat-polymerized acrylic resin Vipi Cril.

  16. Back-biting termination in methyl methacrylate/tert-butyl acrylate anionic block copolymerization

    Czech Academy of Sciences Publication Activity Database

    Čadová, Eva; Dybal, Jiří; Kříž, Jaroslav; Vlček, Petr; Janata, Miroslav; Toman, Luděk

    2008-01-01

    Roč. 209, č. 16 (2008), s. 1657-1665 ISSN 1022-1352 Institutional research plan: CEZ:AV0Z40500505 Keywords : acrylates * anionic polymerization * spontaneous termination Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.202, year: 2008

  17. Acrylated Palm Oil Resins for Radiation (UV) Curing of Over Print Varnish (OPV)

    International Nuclear Information System (INIS)

    Norshamsul Arif; Mohd Hilmi Mahmood; Khairul Zaman Mohd Dahlan; Rosley Che Ismail; Flora Sim; Sharilla Muhammad Faizal

    2010-01-01

    The purpose of this project was to determine the effects of Acrylated Epoxidized Palm Oil (EPOLA) on a radiation (UV) curing Over Print Varnish (OPV) application. The initial target was to produce an environmentally friendly resin (non-VOC) and reduce the dependence on petroleum (hydrocarbon) based products which are more toxic. Toxicity was determined via Acute Oral Toxicity (LD50), OECD 401 and Acute Toxicity (Dermal), OECD 402 technique whilst the reactivity, chemical resistance and other physical properties were obtained from actual printing application test. The developed EPOLA resin was combined with acrylated monomers, photo initiator(s) and additives in typical OPV formulation before being chemically converted into protective glossy printed film under Ultra Violet (UV-C) light. The gloss, flexibility and adhesion effects are significantly greater than conventional OPV epoxy based coupled with further extremely low irritancy to skin. The contributions of this project are twofold. First, the toxicity of developed acrylated Palm Oil resin is certainly lower than conventional epoxy acrylates resin. Secondly, the benefits towards radiation curing OPV applications were significantly demonstrated. (author)

  18. Color Stability of Heat‑cure Acrylic Resin Subjected to Simulated ...

    African Journals Online (AJOL)

    Background: Regular usage of denture cleansers is recommended in complete denture wearers for effective plaque control, and these cleansers alter the physical properties of acrylic resin over a period of time. Thus, an in vitro study was carried out to assess the effect of denture cleansers on the color stability of heat‑cure ...

  19. The influence of cyclic loading on gentamicin release from acrylic bone cements

    NARCIS (Netherlands)

    Hendriks, JGE; Neut, D; Hazenberg, JG; Verkerke, GJ; van Horn, [No Value; van der Mei, HC; Busscher, HJ

    Antibiotic-loaded acrylic bone cement is widely used in total joint replacement to reduce infections. Walking results in cyclic loading, which has been suggested to stimulate antibiotic release. The goal of this study is to compare antibiotic release from cyclically loaded bone cement with the

  20. Heat-cured Acrylic Resin versus Light-activated Resin: A Patient ...

    African Journals Online (AJOL)

    2018-01-30

    Jan 30, 2018 ... the performance of a mandibular implant‑supported overdenture constructed from a heat‑cured ... on evaluating different aspects of the denture and overall satisfaction. The second ... Any type of acrylic denture base fracture presents a .... occlusion, and ability to chew after using the assigned denture for 6 ...

  1. The Cherenkov correlated timing detector: beam test results from quartz and acrylic bars

    International Nuclear Information System (INIS)

    Kichimi, H.; Sugaya, Y.; Yamaguchi, H.; Yoshimura, Y.; Kanda, S.; Olsen, S.; Ueno, K.; Varner, G.; Bergfeld, T.; Bialek, J.; Lorenc, J.; Palmer, M.; Rudnick, G.; Selen, M.; Auran, T.; Boyer, V.; Honscheid, K.; Tamura, N.; Yoshimura, K.; Lu, C.; Marlow, D.; Mindas, C.; Prebys, E.; Asai, M.; Kimura, A.; Hayashi, S.

    1996-01-01

    Several prototypes of a Cherenkov correlated timing (CCT) detector have been tested at the KEK-PS test beam line. We describe the results for Cherenkov light yields and timing characteristics from quartz and acrylic bar prototypes. A Cherenkov angle resolution is found to be 15 mrad at a propagation distance of 100 cm with a 2 cm thick quartz bar prototype. (orig.)

  2. Extraction Equilibrium of Acrylic Acid by Aqueous Two-Phase Systems Using Hydrophilic Ionic Liquids

    International Nuclear Information System (INIS)

    Lee, Yong Hwa; Lee, Woo Youn; Kim, Ki-Sub; Hong, Yeon Ki

    2014-01-01

    As an effective method for extraction of acrylic acid, aqueous two-phase systems based on morpholinium ionic liquids were used in this study. Effects of the alkyl chain length of cation in morpholinium ionic liquids on phase diagram and extraction efficiencies were investigated. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of morpholinium ionic liquids to aqueous K 2 HPO 4 solutions. It can be found that the ability of morpholinium ionic liquids for phase separation followed the order [HMMor][Br]>[OMMor][Br]>[BMMor][Br]>[EMMor][Br]. There was little difference between binodal curves of imidazolium ionic liquids and those of morpholinium ionic liquids. 50-90% of the extraction efficiency was observed for acrylic acid by aqueous two phase extraction of acrylic acid with morpholinium ionic liquids. It can be concluded that morpholinium ionic liquids/K 2 HPO 4 were effective for aqueous two phases extraction of acrylic acid comparing to imidazolium ionic liquids/K 2 HPO 4 systems because of their lower cost

  3. Effect of Microwave Cured Acrylic Resin on Candidal Growth in Complete denture

    International Nuclear Information System (INIS)

    Rasmy, A.H.M.

    2009-01-01

    This study was conducted to evaluate the effect of heat-cured acrylic resin denture base and microwave-cured acrylic resin denture base on Candidal growth. Seven completely edentulous male patients with no history of denture wearing participated in this study. All the selected patients were re-habilitated by mucosa supported complete dentures. The dentures were constructed from conventional heat-cured acrylic resin denture base following monoplane concept of occlusion. Before dismissing the patients and one month after denture insertion, salivary samples were collected according to oral rinse technique. One month resting period was allowed so as Candidal count can reach to normal. Then dentures were re based using microwave-cured acrylic denture base, before denture insertion and one month after denture insertion, salivary sample were collected before and one month following the same oral rinse technique. In the oral rinse technique, the patients were instructed to rinse their mouths with 10 mL of sterile phosphate buffered saline for 60 seconds. The rinse was then expectorated into a universal container and immediately transported to the laboratory for concentration by centrifugation, then cultured on sabouraud's dextrose agar plates which were incubated at 37 degree C for 48 hours. Microscopic examination and germ tube test were carried out for laboratory investigations. In addition, the morphological features of the isolated Candida from the samples tested in this study, were investigated using the scanning electron microscope(SEM)

  4. Evaluation of thermal conductivity of heat-cured acrylic resin mixed with A1203

    Directory of Open Access Journals (Sweden)

    Ebadian B.

    2002-08-01

    Full Text Available One of the most important characteristics of denture base is thermal conductivity. This property has a major role in secretions of salivary glands and their enzymes, taste of the food and gustatory response. Polymethyl methacrylate used in prosthodontics is relatively an insulator. Different materials such as metal fillers and ceramics have been used to solve this problem. The aim of this study was the evaluation of AI2O3 effect on thermal conductivity of heat-cured acrylic resin. Acrylic resin was mixed with AI2O3 in two different weight rates (15 and 20 % of weight. So, group 1 and 2 were divided on this basis. Samples with pure acrylic resin were considered as control group. 18 cylindrical patterns were made in 9x9 mm dimensions and thermocouple wires embedded in each sample to act as conductor. The specimens were put in water with 70±1°C thermal range for 10 minutes. Then, thermal conductivity was measured. The results were analyzed with variance analysis and Dunken test. There was significant difference between thermal conductivity of all groups in all period times. It the first seconds, thermal conductivity in groups 1 and 2 were more than control group. Therefore, for developing of thermal conductivity of acrylic resin, A1203 can be used. Certainly, other characteristic of new resin should be evaluated.

  5. Formation of Methyl Acrylate from CO 2 and Ethylene via Methylation of Nickelalactones

    KAUST Repository

    Bruckmeier, Christian; Lehenmeier, Maximilian W.; Reichardt, Robert; Vagin, Sergei; Rieger, Bernhard

    2010-01-01

    The nickel-induced coupling of ethylene and CO2 represents a promising pathway toward acrylates. To overcome the high bond dissociation energies of the M-O moieties, we worked out an in situ methylation of nickelalactones to realize the β

  6. Titanium, zirconium- and hafnium containing initiators in the polymerization of acrylic monomers to ''living'' polymers

    International Nuclear Information System (INIS)

    Farnham, W.B.; Hertler, W.R.

    1988-01-01

    This patent describes a process for preparing ''living'' polymer. The process comprises contacting one or more acrylic monomers under polymerizing conditions with a polymerization-initiating amount of a tetra-coordinate organotitanium, organozirconium or organo-hafnium polymerization initiator, and ''living'' polymers produced thereby

  7. The protection of different Italian marbles with two partially flourinated acrylic copolymers

    Science.gov (United States)

    Poli, T.; Toniolo, L.; Chiantore, O.

    Committing stone protection to polymeric materials started in the sixties but the study and knowledge of the complex and multiple interactions between stone and polymers has only been carried out recently. It's important to note that, together with the factors related to the polymeric system itself, intrinsic properties of the stone substrate, like composition, porosity, and crystalline characteristics, play a relevant role. In this paper the issues related to protection of three different Italian marbles have been investigated: Candoglia marble, employed in the building of the Milan Cathedral, Carrara marble, widely used in sculpture and historical architecture, and S. Giuliano marble, used in the building of the Pisa Cathedral and its famous leaning tower. Specimens coming from blocks of the three quarried stones have been characterized, treated with two new partially fluorinated acrylic copolymers, 2,2,2-trifluoroethyl methacrylate/methyl acrylate (TFEMA/MA), and trifluoromethyl-2,2,2-trifluorethyl methacrylate/methyl acrylate (HFIMA/MA), and tested according to UNI-Normal Italian protocol. All the measurements including capillary water absorption, static contact angles, colour variation, water vapour permeability, and SEM morphological analysis have been carried out before and after the polymeric treatment. The aim of this work is to evaluate the protective efficacy of these two new partially fluorinated acrylic copolymers on the three different marbles, and to correlate the different behaviours with the polymers' properties and with the stone substrates characteristics.

  8. Propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Il [Kangwon National University, Chuncheon (Korea, Republic of); Choi, Bok Kyoung [Maritime Security Research Center, KIOST, Ansan (Korea, Republic of)

    2014-12-15

    The present study aims to investigate the propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom. The velocities of the guided waves in a 5-mm-thick acrylic plate were measured by using the axial transmission technique. A pure A0 Lamb mode could be successfully launched in the 5-mm-thick acrylic plate through a time reversal process of Lamb waves, consistent with the fact that the time reversal process can automatically compensate for the dispersive nature of Lamb waves. The experimental velocities of the slow guided wave (SGW) and the time-reversed Lamb wave were found to be in reasonable agreement with the theoretical group velocity of the A0 Lamb mode, suggesting that both the SGW and the time-reversed Lamb wave excited in the 5-mm-thick acrylic plate correspond to the A0 Lamb mode. These results suggest that the time reversal process of Lamb waves can be usefully applied to noninvasive characterization of long cortical bones.

  9. Investigation of crafting polymerization of acrylic acid to cellulose materials under the action of accelerated electrons

    International Nuclear Information System (INIS)

    Valiev, A.; Bazhenov, L.G.; Asamov, M.K.; Sagatov, Eh.A.

    1996-01-01

    Crafting polymerization of acrylic acid (AA) to cellulose materials in the presence of copper, zinc and silver salts under the action of accelerated electrons has been investigated with the aim to attach anti microbe properties to these materials. (author). 2 refs., 1 tab

  10. Emulsion (Co)polymerization of styrene and butyl acrylate monitored by On-line Raman Spectroscopy

    NARCIS (Netherlands)

    van den Brink, H.J.T.; Pepers, M.L.H.; Herk, van A.M.; German, A.L.

    2000-01-01

    The homo- and copolymerizations of styrene and n-butyl acrylate were studied by on-line in-situ Raman spectroscopy.Results from the solution (homo)polymerizations proved to be very useful in the quantification of the Raman data from the emulsion homopolymerization. From the homopolymerization data

  11. Characterization of Z-RAFT star polymerization of butyl acrylate by size-exclusion chromatography

    NARCIS (Netherlands)

    Boschmann, D.; Edam, R.; Schoenmakers, P.J.; Vana, P.

    2009-01-01

    Z-RAFT star polymerization of butyl acrylate using multifunctional trithiocarbonate-type RAFT agents carrying methyl propionate as the leaving group were used to form star polymers having 3, 4, and 6 arms. The polymerizations showed well controlled behavior up to high monomer conversions. By using a

  12. Continuous ARGET ATPR of methyl methacrylate and butyl acrylate in a stirred tank reactor

    NARCIS (Netherlands)

    Chan, N.; Meuldijk, J.; Cunningham, M.F.; Hutchinson, R.A.

    2013-01-01

    ARGET ATRP (activator regenerated by electron transfer atom transfer radical polymerization) of butyl acrylate (BA) and methyl methacrylate (MMA) was successfully adapted from a batch process to a continuous stirred tank reactor (CSTR) with 50 ppm copper. A series of batch polymerizations were first

  13. Critically evaluated rate coefficients for free-radical polymerization, 5. Propagation rate coefficient for butyl acrylate

    NARCIS (Netherlands)

    Asua, J.M.; Beuermann, S.; Buback, M.; Castignolles, P.; Charleux, B.; Gilbert, R.G.; Hutchinson, R.A.; Leiza, J.R.; Nikitin, A.N.; Vairon, J.P.; Herk, van A.M.

    2004-01-01

    Propagation rate coefficients, kp, for free-radical polymerization of butyl acrylate (BA) previously reported by several groups are critically evaluated. All data were determined by the combination of pulsed-laser polymerization (PLP) and subsequent polymer analysis by size exclusion (SEC)

  14. Propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom

    International Nuclear Information System (INIS)

    Lee, Kang Il; Choi, Bok Kyoung

    2014-01-01

    The present study aims to investigate the propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom. The velocities of the guided waves in a 5-mm-thick acrylic plate were measured by using the axial transmission technique. A pure A0 Lamb mode could be successfully launched in the 5-mm-thick acrylic plate through a time reversal process of Lamb waves, consistent with the fact that the time reversal process can automatically compensate for the dispersive nature of Lamb waves. The experimental velocities of the slow guided wave (SGW) and the time-reversed Lamb wave were found to be in reasonable agreement with the theoretical group velocity of the A0 Lamb mode, suggesting that both the SGW and the time-reversed Lamb wave excited in the 5-mm-thick acrylic plate correspond to the A0 Lamb mode. These results suggest that the time reversal process of Lamb waves can be usefully applied to noninvasive characterization of long cortical bones.

  15. Long-term toughness of photopolymerizable (meth)acrylate networks in aqueous environments.

    Science.gov (United States)

    Smith, Kathryn E; Trusty, Phillip; Wan, Beatrice; Gall, Ken

    2011-02-01

    Photopolymerizable (meth)acrylate networks are potentially advantageous biomaterials due to their ability to be formed in situ, their fast synthesis rates and their tailorable material properties. The objective of this study was to evaluate how immersion time in phosphate-buffered saline (PBS) affects the toughness of photopolymerizable methyl acrylate (MA)-co-methyl methacrylate-co-poly(ethylene glycol) dimethacrylate networks containing various concentrations of MA. Stress-strain behavior was determined by performing tensile strain to failure testing after soaking in PBS for different periods (1 day up to 9 months). In tandem, differential scanning calorimetry and PBS content measurements were undertaken at each time point in order to determine whether time-dependent changes in toughness were related to changes in T(g) or PBS absorption. The effect of immersion time on network toughness was shown to be dependent upon composition in a manner related to the viscoelastic state of the polymer upon initial immersion in PBS. The results demonstrate that tough acrylate-based materials may not maintain their toughness after several months in PBS. In addition, decreasing the PBS content by changing the network hydrophobicity resulted in better toughness maintenance after 9 months. The results provide a possible means to toughen various amorphous acrylate-based implant materials that are being explored for load-bearing biomedical applications, beyond the systems considered in this work. Published by Elsevier Ltd.

  16. Rheological Behavior of Reaction Mixtures during the Graft Copolymerization of Cassava Starch with Acrylic Acid

    NARCIS (Netherlands)

    Witono, J.R.; Noordergraaf, Inge; Heeres, Hero; Janssen, L.P.B.M.

    2017-01-01

    Literature data on the rheological behavior of a reaction mixture during the graft copolymerization of acrylic acid onto gelatinized starch are scarce. Yet, such information is important for process design. In this work, continuous torque recording was found to be a suitable method to monitor the

  17. A green-emitting CdSe/Poly(butyl acrylate) nanocomposite

    NARCIS (Netherlands)

    Peres, M.; Costa, L.C.; Neves, A.; Soares, M.J.; Monteiro, T.; Carvalho Esteves, de A.C.; Barros-Timmons, A.M.M.V.; Trindade, T.; Kholkin, A.; Alves, E.

    2005-01-01

    CdSe/poly(butyl acrylate) nanocomposites were synthesized by in situ miniemulsion polymerization. The hybrid nanomaterial is very stable and presents a bright green photoluminescence at 2.29 eV under ultraviolet excitation. With the excitation conditions used the intensity of the emission band keeps

  18. Catalytic acetoxylation of lactic acid to 2-acetoxypropionic acid, en route to acrylic acid

    NARCIS (Netherlands)

    Beerthuis, R.; Granollers, M.; Brown, D.R.; Salavagione, H.J.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    We present an alternative synthetic route to acrylic acid, starting from the platform chemical lactic acid and using heterogeneous catalysis. To improve selectivity, we designed an indirect dehydration reaction that proceeds via acetoxylation of lactic acid to 2-acetoxypropionic acid. This

  19. Simulation of 20-year deterioration of acrylic IOLs using severe accelerated deterioration tests.

    Science.gov (United States)

    Kawai, Kenji; Hayakawa, Kenji; Suzuki, Takahiro

    2012-09-20

    To investigate IOL deterioration by conducting severe accelerated deterioration testing of acrylic IOLs. Department of Ophthalmology, Tokai University School of Medicine Methods: Severe accelerated deterioration tests performed on 7 types of acrylic IOLs simulated 20 years of deterioration. IOLs were placed in a screw tube bottle containing ultra-pure water and kept in an oven (100°C) for 115 days. Deterioration was determined based the outer appearance of the IOL in water and under air-dried conditions using an optical microscope. For accelerated deterioration of polymeric material, the elapse of 115 days was considered to be equivalent to 20 years based on the Arrhenius equation. All of the IOLs in the hydrophobic acrylic group except for AU6 showed glistening-like opacity. The entire optical sections of MA60BM and SA60AT became yellowish white in color. Hydrophilic acrylic IOL HP60M showed no opacity at any of the time points examined. Our data based on accelerated testing showed differences in water content to play a major role in transparency. There were differences in opacity among manufacturers. The method we have used for determining the relative time of IOL deterioration might not represent the exact clinical setting, but the appearance of the materials would presumably be very similar to that seen in patients.

  20. The application of FT-IR spectrum method in photocuring process for polyester acrylate

    International Nuclear Information System (INIS)

    Cao Jin; Lu Xianliang; Zhang Zhenli

    1995-01-01

    This paper describes that the UV curing process of polyester acrylate can be monitored by measuring the degree of double bonds conversion with FT-IR spectroscopy. The various factors effect the UV curing rate. The relation between the curing rate and the concentration of photoinitiator, crosslinking agent, UV light intensity was discussed. (author)

  1. Polymer coating comprising 2-methoxyethyl acrylate units synthesized by surface-initiated atom transfer radical polymerization

    DEFF Research Database (Denmark)

    2011-01-01

    Source: US2012184029A The present invention relates to preparation of a polymer coating comprising or consisting of polymer chains comprising or consisting of units of 2-methoxyethyl acrylate synthesized by Surface-Initiated Atom Transfer Radical Polymerization (SI ATRP) such as ARGET SI ATRP...

  2. Syntheses of monomers in the reaction of hexamethylolmelamine with 2-hydroxyethyl acrylate and their photocuring

    International Nuclear Information System (INIS)

    Huhui Houlianbo Hufei

    1999-01-01

    A process has been developed for the syntheses of monomers from 2-hydroxyethyl acrylate and hexamethylolmelamine. Their structure were identified by IR and sub 1H-NMR. The photocuring characteristics of these compound and properties of the UV-cured films have been studied

  3. Acrylic acid surface-modified contact lens for the culture of limbal stem cells.

    Science.gov (United States)

    Zhang, Hong; Brown, Karl David; Lowe, Sue Peng; Liu, Guei-Sheung; Steele, David; Abberton, Keren; Daniell, Mark

    2014-06-01

    Surface treatment to a biomaterial surface has been shown to modify and help cell growth. Our aim was to determine the best surface-modified system for the treatment of limbal stem cell deficiency (LSCD), which would facilitate expansion of autologous limbal epithelial cells, while maintaining cultivated epithelial cells in a less differentiated state. Commercially available contact lenses (CLs) were variously surface modified by plasma polymerization with ratios of acrylic acid to octadiene tested at 100% acrylic acid, 50:50% acrylic acid:octadiene, and 100% octadiene to produce high-, mid-, and no-acid. X-ray photoelectron spectroscopy was used to analyze the chemical composition of the plasma polymer deposited layer. Limbal explants cultured on high acid-modified CLs outgrew more cells. Immunofluorescence and RT2-PCR array results indicated that a higher acrylic acid content can also help maintain progenitor cells during ex vivo expansion of epithelial cells. This study provides the first evidence for the ability of high acid-modified CLs to preserve the stemness and to be used as substrates for the culture of limbal cells in the treatment of LSCD.

  4. The adhesion of SiNx thin layers on silica-acrylate coated polymer substrates

    NARCIS (Netherlands)

    Abdallah, Amir; Lu, K.; Ovchinnikov, C.D.; Bulle-Lieuwma, C.W.T.; Bouten, P.C.P.; With, de G.

    2009-01-01

    Plasma Enhanced Chemical Vapor Deposition (PECVD) was used to grow 200, 300 and 400 nm thick silicon nitride layers (SiN x ) on a high temperature aromatic polyester substrate spin coated with a silica-acrylate hybrid coating (hard coat). Layers deposited without oxygen plasma treatment remained

  5. Dielectric properties of solution-grown-undoped and acrylic-acid ...

    Indian Academy of Sciences (India)

    Dielectric capacities and losses were measured, in the temperature (50–170°C) and frequency (01–100 kHz range), for undoped and acrylic acid (AA) doped ethyl cellulose (EC) films (thickness about 20 m) with progressive increase in the concentration of dopant in the polymer matrix. The variation of capacity with ...

  6. Allergic contact dermatitis caused by isobornyl acrylate in OmniPod, an innovative tubeless insulin pump.

    Science.gov (United States)

    Raison-Peyron, Nadia; Mowitz, Martin; Bonardel, Nathalie; Aerts, Olivier; Bruze, Magnus

    2018-04-10

    The frequency of allergic contact dermatitis caused by (meth)acrylates is increasing worldwide, and isobornyl acrylate (IBOA) has been identified as a culprit sensitizer in FreeStyle Libre, a medical device used by diabetic patients. To report on 4 patients sensitized to IBOA contained in OmniPod, a new, tubeless insulin pump, and to describe the clinical and chemical analytical work-up. Four patients with eczematous skin eruptions after using OmniPod, including 2 with previous adverse skin reactions to FreeStyle Libre, were patch tested with a baseline series and additional (meth)acrylates, including IBOA in several concentrations and/or vehicles. Gas chromatography-mass spectrometry (GC-MS) was used to identify the presence of IBOA in OmniPod. All patients were shown to be sensitized to IBOA. GC-MS identified IBOA in OmniPod, with the highest concentrations being found in the unit itself and not in the adhesive patch. The OmniPod tubeless insulin pump is another source of IBOA, and its use may lead to primary sensitization to this acrylate, or may provoke elicitation of allergic contact dermatitis in previously sensitized patients. Our cases highlight the need to obtain satisfactory cooperation from pharmaceutical companies involved in the manufacture of these widely used medical devices. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Deep UV patterning of acrylic masters for molding biomimetic dry adhesives

    International Nuclear Information System (INIS)

    Sameoto, D; Menon, C

    2010-01-01

    We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance

  8. In vitro release of doxycycline from bioabsorbable materials and acrylic strips

    DEFF Research Database (Denmark)

    Larsen, T

    1990-01-01

    Treatment of marginal periodontitis may include use of local antibiotics. In the present in vitro study the bioabsorbable materials Surgicel, Tissell, and CollaCote and acrylic strips were examined for release of doxycycline into liquids and residual antibacterial activity of the materials. Pieces...

  9. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, coco, N-[3-(dibutylamino... Specific Chemical Substances § 721.10192 Amides, coco, N-[3-(dibutylamino)propyl], acrylates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides...

  10. Preprosthetic therapy utilizing a temporary occlusal acrylic splint: a case report.

    Science.gov (United States)

    Badel, Tomislav; Kraljeviç, Sonja; Panduriç, Josip; Marotti, Miljenko

    2004-05-01

    This case report describes the complex occlusal rehabilitation of a patient with signs and symptoms of temporomandibular disorders with utilization of an occlusal acrylic splint as a means of initial treatment for neuromuscular reprogramming and repositioning of the condyle within the mandibular fossa for occlusal stability, thus allowing adaptation to a new occlusal vertical dimension.

  11. Thermal behavior of flax and jute reinforced in matrix acrylic composite

    Czech Academy of Sciences Publication Activity Database

    Samal, Sneha Manjaree; Stuchlík, M.; Petrikova, I.

    2017-01-01

    Roč. 131, č. 2 (2017), s. 1-6 ISSN 1388-6150 Institutional support: RVO:68378271 Keywords : flax * jute * acrylic resin * composite * DMA * TG * FTIR Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.953, year: 2016

  12. Termite and fungal resistance of in situ polymerized tributyltin acrylate and acetylated Indonesian and USA wood

    Science.gov (United States)

    Rebecca E. Ibach; Yusuf Sudo Hadi; Dodi Nandika; Sulaeman Yusuf; Yuliati Indrayani

    2000-01-01

    Wood [Indonesian pine (IP), Indonesian Jabon (IJ) and USA southern yellow pine (USP)] was either in situ polymerized with tributyltin acrylate (TBTA) or acetylated and then exposed to termite and fungal degradation both in laboratory tests and field exposure. The TBTA woods had an average weight percent gain (WPG) of 11% for IP, 12% for IJ, and 10% for USP. The...

  13. Effect of silver nano particles on flexural strength of acrylic resins.

    Science.gov (United States)

    Sodagar, Ahmad; Kassaee, Mohammad Zaman; Akhavan, Azam; Javadi, Negar; Arab, Sepideh; Kharazifard, Mohammad Javad

    2012-04-01

    Poly(methyl methacrylate), PMMA, is widely used for fabrication of removable orthodontic appliances. Silver nano particles (AgNps) have been added to PMMA because of their antimicrobial properties. The aim of this study is to investigate the effect of AgNps on the flexural strength of PMMA. Acrylic liquid containing 0.05% and 0.2% AgNps was prepared for two kinds of acrylic resins: Rapid Repair &Selecta Plus. Two groups without AgNps were used as control groups. For each one, flexural strength was investigated via Three Point Bending method for the 15 acrylic blocks. Two-way ANOVA, one way ANOVA and Tukey tests were used for statistical analysis. Rapid Repair without AgNps showed the highest flexural strength. Addition of 0.05% AgNps to Rapid Repair, significantly decreased its flexural strength while, continuing the addition up to 0.2% increased it nearly up to its primary level. In contrast, addition of AgNps to Selecta Plus increased its flexural strength but addition of 0.05% nano particles was more effective than 0.2%. The effect of AgNps on flexural strength of PMMA depends on several factors including the type of acrylics and the concentrations of nano particles. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  14. Siloxane urethane acrylate radiation curable compounds for use in coating compositions

    International Nuclear Information System (INIS)

    Friedlander, C.B.; McMullen, J.C.

    1978-01-01

    Radiation curable compounds are disclosed which are derived from the reaction of siloxy-containing carbinol, a polyisocyanate and a polyfunctional compound having hydroxy and acrylic functional groups. The compounds have high cure rates, are compatible with other components of radiation curable, film forming compositions and impart good slip and other properties to cured film coatings

  15. Transdermal thiol-acrylate polyethylene glycol hydrogel synthesis using near infrared light

    Science.gov (United States)

    Chung, Solchan; Lee, Hwangjae; Kim, Hyung-Seok; Kim, Min-Gon; Lee, Luke P.; Lee, Jae Young

    2016-07-01

    Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation via a mixed-mode reaction with a small increase in temperature (~5 °C) under the optimized conditions. We also achieved successful transdermal gelation via the NIR-assisted photothermal thiol-acryl reactions. This new type of NIR-assisted thiol-acrylate polymerization provides new opportunities for in situ hydrogel formation for injectable hydrogels and delivery of drugs/cells for various biomedical applications.Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation

  16. Comparison of water sorption and solubility of Acropars and Meliodent heat cure acrylic resins

    Directory of Open Access Journals (Sweden)

    Golbidi F

    2006-06-01

    Full Text Available Background and Aim: Water sorption and solubility are important properties of acrylic resins. Denture base acrylic resins have low solubility. This solubility results from the leaching out of unreacted monomer and water soluble additives into the oral fluids. The solubility of denture bases can cause oral soft tissue reactions. In addition, water absorbed into this material acts as a plasticizer and decreases the mechanical properties such as hardness, transverse strength, fatigue limit and also can change the color and dimensional stability. The aim of this study was to compare the water sorption and solubility of Acropars and Meliodent heat cure acrylic resins. Materials and Methods: This experimental study was performed on the basis of ADA specification No.12 and ISO No.1567 and standards NO: 2571 of Institute of Standards & Industrial Research of Iran. Six disc form samples of each acrylic resin were prepared, with the dimension of 50×0.5 mm. After desiccating, the samples were kept in an oven for 24 hours and weighed. Then they were immersed in water, kept in oven for 7 days and weighed again. After this phase, the samples were carried to a dessicator, for 24 hours and kept in an oven for drying and were weighed for the third time. Data were analyzed with Mann Whitney and one sample t-test. P<0.05 was considered as the limit of significance. Results: Water sorption mean values were 30.5±0.1 µg/mm3 or 0.76±0.01 mg/cm2 for Meliodent samples and 30.7±0.87 µg/mm3 or 0.77±0.009 mg/cm2 for Acropars samples. No significant difference was observed in water sorption of these two materials (P=0.9. Meliodent acrylic resin showed lower solubility (1.7±0.097 µg/mm3 or 0.042±0.001 mg/cm2 than Acropars acrylic resin (2.5±0.13 µg/mm3 or 0.062±0.001 mg/cm2 (P=0.002. Conclusion: Acropars heat cure acrylic resin matched well with the requirements of the international standards for water sorption, but its solubility was not favorable. This problem

  17. Aphasia following anterior cerebral artery occlusion

    International Nuclear Information System (INIS)

    Shimosaka, Shinichi; Waga, Shiro; Kojima, Tadashi; Shimizu, Takeo; Morikawa, Atsunori

    1982-01-01

    We have report two cases of aphasia that had infarcts in the distribution of the left or right anterior cerebral artery, as confirmed by computed tomography. Case 1 is a right-handed, 65-year-old man in whom computerized tomographic scanning revealed an infarction of the territory of the left anterior cerebral artery after the clipping of the anterior communicating artery aneurysm. The standard language test of aphasia (SLTA) revealed non-fluent aphasia with dysarthria, good comprehension, almost normal repetition with good articulation, and a defectiveness in writing. This syndrome was considered an instance of transcortical motor aphasia. Although three years had passed from the onset, his aphasia did not show any improvement. Case 2 is a 37-year-old man who is right-handed but who can use his left hand as well. He was admitted because of subarachnoid hemorrhage from an anterior communicating aneurysm. Because of postoperative spasm, an infarction in the distribution of the right anterior cerebral artery developed. He was totally unable to express himself vocally, but he could use written language quite well to express his ideas and had a good comprehension of spoken language. This clinical picture was considered that of an aphemia. After several weeks, his vocalization returned, but the initial output was still hypophonic. (J.P.N.)

  18. Innervation of the Anterior Sacroiliac Joint.

    Science.gov (United States)

    Cox, Marcus; Ng, Garrett; Mashriqi, Faizullah; Iwanaga, Joe; Alonso, Fernando; Tubbs, Kevin; Loukas, Marios; Oskouian, Rod J; Tubbs, R Shane

    2017-11-01

    Sacroiliac joint pain can be disabling and recalcitrant to medical therapy. The innervation of this joint is poorly understood, especially its anterior aspect. Therefore, the present cadaveric study was performed to better elucidate this anatomy. Twenty-four cadaveric sides underwent dissection of the anterior sacroiliac joint, with special attention given to any branches from regional nerves to this joint. No femoral, obturator, or lumbosacral trunk branches destined to the anterior sacroiliac joint were identified in the 24 sides. In 20 sides, one or two small branches (less than 0.5 mm in diameter) were found to arise from the L4 ventral ramus (10%), the L5 ventral ramus (80%), or simultaneously from both the L4 and L5 ventral rami (10%). The length of the branches ranged from 5 to 31 mm (mean, 14 mm). All these branches arose from the posterior part of the nerves and traveled to the anterior surface of the sacroiliac joint. No statistical significance was found between sides or sexes. An improved knowledge of the innervation of the anterior sacroiliac joint might decrease suffering in patients with chronic sacroiliac joint pain. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Predicted solar cell edge radiation effects

    International Nuclear Information System (INIS)

    Gates, M.T.

    1993-01-01

    The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT

  20. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin.

    Science.gov (United States)

    Ekren, Orhun; Ozkomur, Ahmet

    2016-08-01

    The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials.

  1. Adsorption of uranium ions by crosslinked polyester resin functionalized with acrylic acid from aqueous solutions

    International Nuclear Information System (INIS)

    Cemal Oezeroglu; Niluefer Metin

    2012-01-01

    In this paper, the crosslinked polyester resin containing acrylic acid functional groups was used for the adsorption of uranium ions from aqueous solutions. For this purpose, the crosslinked polyester resin of unsaturated polyester in styrene monomer (Polipol 353, Poliya) and acrylic acid as weight percentage at 80 and 20%, respectively was synthesized by using methyl ethyl ketone peroxide (MEKp, Butanox M60, Azo Nobel)-cobalt octoate initiator system. The adsorption of uranium ions on the sample (0.05 g copolymer and 5 mL of U(VI) solution were mixed) of the crosslinked polyester resin functionalized with acrylic acid was carried out in a batch reactor. The effects of adsorption parameters of the contact time, temperature, pH of solution and initial uranium(VI) concentration for U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid were investigated. The adsorption data obtained from experimental results depending on the initial U(VI) concentration were analyzed by the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) adsorption isotherms. The adsorption capacity and free energy change were determined by using D-R isotherm. The obtained experimental adsorption data depending on temperature were evaluated to calculate the thermodynamic parameters of enthalpy (ΔH o ), entropy (ΔS o ) and free energy change (ΔG o ) for the U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid from aqueous solutions. The obtained adsorption data depending on contact time were analyzed by using adsorption models such as the modified Freundlich, Elovich, pseudo-first order and pseudo-second-order kinetic models. (author)

  2. The use of epoxidised palm oil products (EPOP) for the synthesis of radiation curable resins 1. Synthesis of epoxidised RBD palm olein acrylate

    International Nuclear Information System (INIS)

    Hussin bin Mohd Nor; Mohd Hilmi bin Mahmood; Hamirin bin Kifli; Masni bin Abdul Rahman; Azman bin Rafie

    1990-01-01

    The synthesis of acrylated olein utilizing epoxidised refined, bleached and deodorized (RBD) palm olein has been carried out by acrylation reaction. This is done by the introduction of acrylic acid into oxirane group of the epoxidised RBD palm olein. The reaction was confirmed by analytical data i.e. oxirane oxygen content, iodine value and acid value and IR spectrophotometric method. It was found that, oxirane group in triglyceride molecule of epoxidised RBD palm olein (EPOL) is attacked by acrylic acid to yield epoxidised RBD palm olein acrylate (EPOLA). The EPOLA was found curable when subjected to ultraviolet radiation

  3. An elderly man with acute anterior neck pain and odynophagia after a meal

    Directory of Open Access Journals (Sweden)

    Irfan Mohamad

    2013-12-01

    Full Text Available The upper aerodigestive tract, specifically the cricopharyngeal area, is the most common site of foreign body impaction. Anatomically, this area is the first constriction of the oesophagus. Fish bones, one of the most common foreign bodies encountered in the throat, tend to get stuck in this area. The movement of this sharp-edged foreign body upon swallowing will induce odynophagia and an acute onset of neck pain. We report a case of a healthy elderly man who complained of sudden anterior neck pain and odynophagia after eating yellowtail scad fish.

  4. Ethical decisions at the edge.

    Science.gov (United States)

    Gillett, Grant

    2008-05-01

    Medicine grows incrementally in its ability to treat patients and at the growing edge it poses problems about the appropriateness of treatments that are different from those where good practice conforms to widely agreed standards. The growth of access to medical knowledge and the diversity of contemporary theoretical and clinical medicine have spawned deep divisions in the profession and divergent opinions about what constitutes reasonable care. That hallmark of acceptable practice is also under pressures from the threat of litigation, a highly commercialised contemporary medical environment, patient demands based on medical journalism and the internet and the exponential growth of bio-medical technology. Patient empowerment can result in complaints arising in new and complex areas and expert opinion can often differ markedly depending on where on the medical spectrum the experts are aligned. This column lays out some broad-brush principles to assess the adequacy of medical advice in such a climate.

  5. Imaging edges of nanostructured graphene

    DEFF Research Database (Denmark)

    Kling, Jens; Cagliani, Alberto; Booth, T. J.

    Graphene, as the forefather of 2D-materials, attracts much attention due to its extraordinary properties like transparency, flexibility and outstanding high conductivity, together with a thickness of only one atom. However, graphene also possesses no band gap, which makes it unsuitable for many...... electronic applications like transistors. It has been shown theoretically that by nanostructuring pristine graphene, e.g. with regular holes, the electronic properties can be tuned and a band gap introduced. The size, distance and edge termination of these “defects” influence the adaptability....... Such nanostructuring can be done experimentally, but especially characterization at atomic level is a huge challenge. High-resolution TEM (HRTEM) is used to characterize the atomic structure of graphene. We optimized the imaging conditions used for the FEI Titan ETEM. To reduce the knock-on damage of the carbon atoms...

  6. URETHROPLASTY FOR COMPLICATED ANTERIOR URETHRAL STRICTURES.

    Science.gov (United States)

    Aoki, Katsuya; Hori, Shunta; Morizawa, Yosuke; Nakai, Yasushi; Miyake, Makito; Anai, Satoshi; Torimoto, Kazumasa; Yoneda, Tatsuo; Tanaka, Nobumichi; Yoshida, Katsunori; Fujimoto, Kiyohide

    2016-01-01

    (Objectives) To compare efficacy and outcome of urethroplasty for complicated anterior urethral strictures. (Methods) Twelve patients, included 3 boys, with anterior urethral stricture underwent urethroplasty after the failure of either urethral dilatation or internal urethrotomy. We evaluated pre- and post-operative Q max and surgical outcome. (Results) Four patients were treated with end-to-end anastomosis, included a case of bulbar urethral elongation simultaneously, one patient was treated with augmented anastomotic urethroplasty, three patients were treated with onlay urethroplasty with prepucial flap, one patient was treated with tubed urethroplasty with prepucial flap (Ducket procedure) and three patients were treated with onlay urethroplasty with buccal mucosal graft. Postoperative Qmax improved in all patients without major complications and recurrence during follow-up periods ranging from 17 to 102 months (mean 55 months). (Conclusions) Urethroplasty is an effective therapeutic procedure for complicated anterior urethral stricture.

  7. Anterior cruciate ligament tears: MRI versus arthroscopy

    International Nuclear Information System (INIS)

    Tosch, U.; Felix, R.; Schauwecker, W.; Dreithaler, B.

    1992-01-01

    Because of suspected rupture of the anterior cruciate ligament sixteen acute traumatised patients were investigated by MR and arthroscopy. The MR diagnosis of a lesion of the anterior cruciate ligament proved to be correct by arthroscopy in fifteen of sixteen cases. Diagnostic criteria for lesions of the anterior cruciate ligament were: increased signal intensity in T 1 - and T 2 weighted images, increased volume and discontinuity of ligamentous structures. Additional MR findings of meniscal tears were correct in three of four cases laterally and in four of four cases medially. Femoral cartilage lesions were correctly identified by MR in three cases. MR normal findings proved to be correct by arthroscopy in another five cases. (orig.) [de

  8. Magnetohydrodynamic stability of tokamak edge plasmas

    International Nuclear Information System (INIS)

    Connor, J.W.; Hastie, R.J.; Wilson, H.R.; Miller, R.L.

    1998-01-01

    A new formalism for analyzing the magnetohydrodynamic stability of a limiter tokamak edge plasma is developed. Two radially localized, high toroidal mode number n instabilities are studied in detail: a peeling mode and an edge ballooning mode. The peeling mode, driven by edge current density and stabilized by edge pressure gradient, has features which are consistent with several properties of tokamak behavior in the high confinement open-quotes Hclose quotes-mode of operation, and edge localized modes (or ELMs) in particular. The edge ballooning mode, driven by the pressure gradient, is identified; this penetrates ∼n 1/3 rational surfaces into the plasma (rather than ∼n 1/2 , expected from conventional ballooning mode theory). Furthermore, there exists a coupling between these two modes and this coupling provides a picture of the ELM cycle

  9. Nonnecrotizing anterior scleritis mimicking orbital inflammatory disease

    Directory of Open Access Journals (Sweden)

    Lynch MC

    2013-08-01

    Full Text Available Michelle Chen Lynch,1 Andrew B Mick21Optometry Clinic, Ocala West Veterans Affairs Specialty Clinic, Ocala, FL, USA; 2Eye Clinic, San Francisco VA Medical Center, San Francisco, CA, USABackground: Anterior scleritis is an uncommon form of ocular inflammation, often associated with coexisting autoimmune disease. With early recognition and aggressive systemic therapy, prognosis for resolution is good. The diagnosis of underlying autoimmune disease involves a multidisciplinary approach.Case report: A 42-year-old African American female presented to the Eye Clinic at the San Francisco Veteran Affairs Medical Center, with a tremendously painful left eye, worse on eye movement, with marked injection of conjunctiva. There was mild swelling of the upper eyelid. Visual acuity was unaffected, but there was a mild red cap desaturation. The posterior segment was unremarkable. The initial differential diagnoses included anterior scleritis and orbital inflammatory disease. Oral steroid treatment was initiated with rapid resolution over a few days. Orbital imaging was unremarkable, and extensive laboratory work-up was positive only for antinuclear antibodies. The patient was diagnosed with idiopathic diffuse, nonnecrotizing anterior scleritis and has been followed for over 5 years without recurrence. The rheumatology clinic monitors the patient closely, as suspicion remains for potential arthralgias including human leukocyte antigen-B27-associated arthritis, lupus-associated arthritis, seronegative rheumatoid arthritis, recurrent juvenile idiopathic arthritis, and scleroderma, based on her constitutional symptoms and clinical presentation, along with a positive anti-nuclear antibody lab result.Conclusion: Untreated anterior scleritis can progress to formation of cataracts, glaucoma, uveitis, corneal melting, and posterior segment disease with significant risk of vision loss. Patients with anterior scleritis must be aggressively treated with systemic anti

  10. Morphometric Study of the Anterior Thalamoperforating Arteries

    Science.gov (United States)

    Kim, Sung-Ho; Yeo, Dong-Kyu; Shim, Jae-Joon; Yoon, Seok-Mann; Chang, Jae-Chil

    2015-01-01

    Objective To evaluate the morphometry of the anterior thalamoperforating arteries (ATPA). Methods A microanatomical study was performed in 79 specimens from 42 formalin-fixed adult cadaver brains. The origins of the ATPAs were divided into anterior, middle, and posterior segments according to the crowding pattern. The morphometry of the ATPAs, including the premammillary artery (PMA), were examined under a surgical microscope. Results The anterior and middle segments of the ATPAs arose at mean intervals of 1.75±1.62 mm and 5.86±2.05 mm from the internal carotid artery (ICA), and the interval between these segments was a mean of 3.17±1.64 mm. The posterior segment arose at a mean interval of 2.43±1.46 mm from the posterior cerebral artery (PCA), and the interval between the middle and posterior segments was a mean of 3.45±1.39 mm. The mean numbers of perforators were 2.66±1.19, 3.03±1.84, and 1.67±0.98 in the anterior, middle, and posterior segments, respectively. The PMA originated from the middle segment in 66% of cases. A perforator-free zone was located >2 mm from the ICA in 30.4% and >2 mm from the PCA in 67.1% of cases. Conclusion Most perforators arose from the anterior and middle segments, within the anterior two-thirds of the posterior communicating artery (PCoA). The safest perforator-free zone was located closest to the PCA. These anatomical findings may be helpful to verify safety when treating lesions around the PCoA and in the interpeduncular fossa. PMID:26113962

  11. Inferior Oblique Overaction: Anterior Transposition Versus Myectomy.

    Science.gov (United States)

    Rajavi, Zhale; Feizi, Mohadeseh; Behradfar, Narges; Yaseri, Mehdi; Sayanjali, Shima; Motevaseli, Tahmine; Sabbaghi, Hamideh; Faghihi, Mohammad

    2017-07-01

    To compare the efficacy of inferior oblique myectomy and anterior transposition for correcting inferior oblique overaction (IOOA). This retrospective study was conducted on 56 patients with IOOA who had either myectomy or anterior transposition of the inferior oblique muscle from 2010 to 2015. The authors compared preoperative and postoperative inferior oblique muscle function grading (-4 to +4) as the main outcome measure and vertical and horizontal deviation, dissociated vertical deviation (DVD), and A- and V-pattern between the two surgical groups as secondary outcomes. A total of 99 eyes of 56 patients with a mean age of 5.9 ± 6.5 years were included (47 eyes in the myectomy group and 52 eyes in the anterior transposition group). There were no differences in preoperative best corrected visual acuity, amblyopia, spherical equivalent, and primary versus secondary IOOA between the two groups. Both surgical procedures were effective in reducing IOOA and satisfactory results were similar between the two groups: 61.7% and 67.3% in the myectomy and anterior transposition groups, respectively (P = .56). After adjustment for the preoperative DVD, there was no statistically significant difference between the two groups postoperatively. The preoperative hypertropia was 6 to 14 and 6 to 18 prism diopters (PD) in the myectomy and anterior transposition groups, respectively. After surgery, no patient had a vertical deviation greater than 5 PD. Both the inferior oblique myectomy and anterior transposition procedures are effective in reducing IOOA with similar satisfactory results. DVD and hypertropia were also corrected similarly by these two surgical procedures. [J Pediatr Ophthalmol Strabismus. 2017;54(4):232-237.]. Copyright 2017, SLACK Incorporated.

  12. CT false-profile view of the hip: a reproducible method of measuring anterior acetabular coverage using volume CT data

    International Nuclear Information System (INIS)

    Needell, Steven D.; Borzykowski, Ross M.; Carreira, Dominic S.; Kozy, John

    2014-01-01

    To devise a simple, reproducible method of using CT data to measure anterior acetabular coverage that results in values analogous to metrics derived from false-profile radiographs. Volume CT images were used to generate simulated false-profile radiographs and cross-sectional false-profile views by angling a multiplanar reformat 115 through the affected acetabulum relative to a line tangential to the posterior margin of the ischial tuberosities. The anterolateral margin of the acetabulum was localized on the CT false-profile view corresponding with the cranial opening of the acetabular roof. Anterior center edge angle (CEA) was measured between a vertical line passing through the center of the femoral head and a line connecting the center of the femoral head with the anterior edge of the condensed line of the acetabulum (sourcil). Anterior CEA values measured on CT false-profile views of 38 symptomatic hips were compared with values obtained on simulated and projection false-profile radiographs. The CT false-profile view produces a cross-sectional image in the same obliquity as false-profile radiographs. Anterior CEA measured on CT false-profile views were statistically similar to values obtained with false-profile radiographs. CT technologists quickly mastered the technique of generating this view. Inter-rater reliability indicated this method to be highly reproducible. The CT false-profile view is simple to generate and anterior CEA measurements derived from it are similar to those obtained using well-positioned false-profile radiographs. Utilization of CT to assess hip geometry enables precise control of pelvic inclination, eliminates projectional errors, and minimizes limitations of image quality inherent to radiography. (orig.)

  13. CT false-profile view of the hip: a reproducible method of measuring anterior acetabular coverage using volume CT data

    Energy Technology Data Exchange (ETDEWEB)

    Needell, Steven D.; Borzykowski, Ross M. [Boca Radiology Group, Boca Raton, FL (United States); Carreira, Dominic S.; Kozy, John [Broward Health Orthopedics and Sports Medicine, Fort Lauderdale, FL (United States)

    2014-11-15

    To devise a simple, reproducible method of using CT data to measure anterior acetabular coverage that results in values analogous to metrics derived from false-profile radiographs. Volume CT images were used to generate simulated false-profile radiographs and cross-sectional false-profile views by angling a multiplanar reformat 115 through the affected acetabulum relative to a line tangential to the posterior margin of the ischial tuberosities. The anterolateral margin of the acetabulum was localized on the CT false-profile view corresponding with the cranial opening of the acetabular roof. Anterior center edge angle (CEA) was measured between a vertical line passing through the center of the femoral head and a line connecting the center of the femoral head with the anterior edge of the condensed line of the acetabulum (sourcil). Anterior CEA values measured on CT false-profile views of 38 symptomatic hips were compared with values obtained on simulated and projection false-profile radiographs. The CT false-profile view produces a cross-sectional image in the same obliquity as false-profile radiographs. Anterior CEA measured on CT false-profile views were statistically similar to values obtained with false-profile radiographs. CT technologists quickly mastered the technique of generating this view. Inter-rater reliability indicated this method to be highly reproducible. The CT false-profile view is simple to generate and anterior CEA measurements derived from it are similar to those obtained using well-positioned false-profile radiographs. Utilization of CT to assess hip geometry enables precise control of pelvic inclination, eliminates projectional errors, and minimizes limitations of image quality inherent to radiography. (orig.)

  14. Edge and line detection of complicated and blurred objects

    OpenAIRE

    Haugsdal, Kari

    2010-01-01

    This report deals with edge and line detection in pictures with complicated and/or blurred objects. It explores the alternatives available, in edge detection, edge linking and object recognition. Choice of methods are the Canny edge detection and Local edge search processing combined with regional edge search processing in the form of polygon approximation.

  15. Reflex muscle contraction in anterior shoulder instability.

    Science.gov (United States)

    Wallace, D A; Beard, D J; Gill, R H; Eng, B; Carr, A J

    1997-01-01

    Reduced proprioception may contribute to recurrent anterior shoulder instability. Twelve patients with unilateral shoulder instability were investigated for evidence of deficient proprioception with an activated pneumatic cylinder and surface electromyography electrodes; the contralateral normal shoulder was used as a control. The latency between onset of movement and the detection of muscle contraction was used as an index of proprioception. No significant difference in muscle contraction latency was detected between the stable and unstable shoulders, suggesting that there was no significant defect in muscular reflex activity. This study does not support the use proprioception-enhancing physiotherapy in the treatment of posttraumatic anterior shoulder instability.

  16. Roentgenographic findings following anterior cervical fusion

    Energy Technology Data Exchange (ETDEWEB)

    Gore, D R; Gardner, G M; Sepic, S B; Murray, M P

    1986-10-01

    We reviewed the pre- and postoperative lateral cervical roentgenograms in 90 patients who had anterior fusions and compared their findings with age and sex-matched people without neck problems. The average interval from surgery to review was 5 years. Preoperatively, all patients had a higher incidence of degenerative spondylosis at the levels to be fused than their asymptomatic counterparts. Postoperatively, there was no difference in the incidence of degenerative change between the operated and the control group at the levels above and below the fusion with the exception of anterior osteophyte formation which was more frequent in those with fusions.

  17. Study of airfoil trailing edge bluntness noise

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Shen, Wen Zhong; Sørensen, Jens Nørkær

    2010-01-01

    This paper deals with airfoil trailing edge noise with special focus on airfoils with blunt trailing edges. Two methods are employed to calculate airfoil noise: The flow/acoustic splitting method and the semi-empirical method. The flow/acoustic splitting method is derived from compressible Navier...... design or optimization. Calculations from both methods are compared with exist experiments. The airfoil blunt noise is found as a function of trailing edge bluntness, Reynolds number, angle of attack, etc....

  18. Selective Electroless Silver Deposition on Graphene Edges

    DEFF Research Database (Denmark)

    Durhuus, D.; Larsen, M. V.; Andryieuski, Andrei

    2015-01-01

    We demonstrate a method of electroless selective silver deposition on graphene edges or between graphene islands without covering the surface of graphene. Modifications of the deposition recipe allow for decoration of graphene edges with silver nanoparticles or filling holes in damaged graphene...... on silica substrate and thus potentially restoring electric connectivity with minimal influence on the overall graphene electrical and optical properties. The presented technique could find applications in graphene based transparent conductors as well as selective edge functionalization and can be extended...

  19. Discursive Maps at the Edge of Chaos

    Science.gov (United States)

    2017-05-25

    Discursive Maps at the Edge of Chaos A Monograph by Major Mathieu Primeau Canadian Army, Royal Canadian Engineer School of Advanced Military...Master’s Thesis 3. DATES COVERED (From - To) JUN 2016 – MAY 2017 4. TITLE AND SUBTITLE Discursive Maps at the Edge of Chaos 5a. CONTRACT NUMBER 5b...meaning of boundaries and polarize conflict towards violence. The edge of chaos is the fine line between disorder and coherence. Discursive maps

  20. Edge effect on weevils and spiders

    OpenAIRE

    Horváth, R.; Magura, T.; Péter, G.; Tóthmérész, B.

    2002-01-01

    The edge effect on weevils and spiders was tested along oak forest – meadow transects using sweep-net samples at the Síkfökút Project in Hungary. For spiders the species richness was significantly higher in the forest edge than either in the meadow or the forest interior. For weevils the species richness of the forest edge was higher than that of the meadow, but the difference was not statistically significant whereas the species richness of the forest...

  1. Radiation crosslinking of poly(butyl acrylate) during polymerization and grafted copolymerization with Cr(III) crosslinked collagen

    International Nuclear Information System (INIS)

    Pietrucha, K.; Kroh, J.

    1984-01-01

    Enhanced crosslinking of synthetic polymer simultaneous with grafting and homopolymerization processes have been observed in irradiated leather tanned with Cr(III) and embedded with aqueous emulsions of butyl acrylate. Extent of poly(butyl acrylate) crosslinking during copolymerization was found to be approximately one order higher than in the case of radiation polymerization of butyl acrylate in emulsion. New method for isolation of grafted copolymer based on degradation of collagen has been developed. The extent of crosslinking was calculated from the swelling data. (author)

  2. Radiation crosslinking of poly(butyl acrylate) during polymerization and grafted copolymerization with Cr(III) crosslinked collagen

    International Nuclear Information System (INIS)

    Pietrucha, K.; Kroh, J.

    1986-01-01

    Enhanced crosslinking of synthetic polymer simultaneously with grafting and homopolymerization processes has been observed in irradiated leather tanned with Cr(III) and embedded with aqueous emulsions of butyl acrylate. The extent of poly(butyl acrylate) crosslinking during copolymerization was found to be approximately one order higher than in the case of radiation polymerization of butyl acrylate in emulsion. A new method for isolation of grafted copolymer based on degradation of collagen has been developed. The extent of crosslinking was calculated from the swelling data. (author)

  3. One-step routes from di- and triblock copolymer precursors to hydrophilic nanoporous poly(acrylic acid)-b-polystyrene

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Jankova Atanasova, Katja; Schulte, Lars

    2008-01-01

    Nanoporous polystyrene with hydrophilic pores was prepared from di- and triblock copolymer precursors. The precursor material was either a poly(tert-butyl acryl ate)-b-polystyrene (PtBA-b-PS) diblock copolymer synthesized by atom transfer radical polymerization (ATRP) or a polydimethylsiloxane......-b-poly(tertbutyl acrylate)-b-polystyrene (PDMS-b-PtBA-b-PS) triblock copolymer synthesized by a combination of living anionic polymerization and ATRP. In the latter copolymer, PS was the matrix and mechanically stable component, PtBA was converted by acidic deprotection to hydrophilic poly(acrylic acid) (PAA) providing...

  4. Separation of water and oil by poly (acrylic acid)-coated stainless steel mesh prepared by radiation crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Young Chang; Shin, Jung Woong; Park, Jong Seok; Lim, Young Mook; Jeun, Joon Pyo; Kang, Phil Hyun [Research Division for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2015-05-15

    The stainless steel mesh coated with poly(acrylic acid) hydrogel was fabricated and applied for the separation of water and oil. The stainless steel mesh was immersed in aqueous poly (acrylic acid) solution, and then irradiated by radiation to introduce poly(acrylic acid) hydrogel on the surface of mesh by crosslinking. It was possible to separate oil and water from mixtures of oil/water effectively using the hydrogel-coated mesh. The effect of irradiation dose, coating thickness, size of mesh on the separation efficiency was examined.

  5. Moveable Leading Edge Device for a Wing

    Science.gov (United States)

    Pitt, Dale M. (Inventor); Eckstein, Nicholas Stephen (Inventor)

    2013-01-01

    A method and apparatus for managing a flight control surface system. A leading edge section on a wing of an aircraft is extended into a deployed position. A deformable section connects the leading edge section to a trailing section. The deformable section changes from a deformed shape to an original shape when the leading edge section is moved into the deployed position. The leading edge section on the wing is moved from the deployed position to an undeployed position. The deformable section changes to the deformed shape inside of the wing.

  6. Visible imaging of edge turbulence in NSTX

    International Nuclear Information System (INIS)

    Zweben, S.; Maqueda, R.; Hill, K.; Johnson, D.

    2000-01-01

    Edge plasma turbulence in tokamaks and stellarators is believed to cause the radical heat and particle flux across the separatrix and into the scrape-off-layers of these devices. This paper describes initial measurements of 2-D space-time structure of the edge density turbulence made using a visible imaging diagnostic in the National Spherical Torus Experiment (NSTX). The structure of the edge turbulence is most clearly visible using a method of gas puff imaging to locally illuminate the edge density turbulence

  7. IMAGE ANALYSIS BASED ON EDGE DETECTION TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    纳瑟; 刘重庆

    2002-01-01

    A method that incorporates edge detection technique, Markov Random field (MRF), watershed segmentation and merging techniques was presented for performing image segmentation and edge detection tasks. It first applies edge detection technique to obtain a Difference In Strength (DIS) map. An initial segmented result is obtained based on K-means clustering technique and the minimum distance. Then the region process is modeled by MRF to obtain an image that contains different intensity regions. The gradient values are calculated and then the watershed technique is used. DIS calculation is used for each pixel to define all the edges (weak or strong) in the image. The DIS map is obtained. This help as priority knowledge to know the possibility of the region segmentation by the next step (MRF), which gives an image that has all the edges and regions information. In MRF model,gray level l, at pixel location i, in an image X, depends on the gray levels of neighboring pixels. The segmentation results are improved by using watershed algorithm. After all pixels of the segmented regions are processed, a map of primitive region with edges is generated. The edge map is obtained using a merge process based on averaged intensity mean values. A common edge detectors that work on (MRF) segmented image are used and the results are compared. The segmentation and edge detection result is one closed boundary per actual region in the image.

  8. Object detection using categorised 3D edges

    DEFF Research Database (Denmark)

    Kiforenko, Lilita; Buch, Anders Glent; Bodenhagen, Leon

    2015-01-01

    is made possible by the explicit use of edge categories in the feature descriptor. We quantitatively compare our approach with the state-of-the-art template based Linemod method, which also provides an effective way of dealing with texture-less objects, tests were performed on our own object dataset. Our...... categorisation algorithm for describing objects in terms of its different edge types. Relying on edge information allow our system to deal with objects with little or no texture or surface variation. We show that edge categorisation improves matching performance due to the higher level of discrimination, which...

  9. Visible imaging of edge turbulence in NSTX

    International Nuclear Information System (INIS)

    S. Zweben; R. Maqueda; K. Hill; D. Johnson; S. Kaye; H. Kugel; F. Levinton; R. Maingi; L. Roquemore; S. Sabbagh; G. Wurden

    2000-01-01

    Edge plasma turbulence in tokamaks and stellarators is believed to cause the radial heat and particle flux across the separatrix and into the scrape-off-layers of these devices. This paper describes initial measurements of 2-D space-time structure of the edge density turbulence made using a visible imaging diagnostic in the National Spherical Torus Experiment (NSTX). The structure of the edge turbulence is most clearly visible using a method of ''gas puff imaging'' to locally illuminate the edge density turbulence

  10. Longitudinal Evaluation of Wound Healing after Penetrating Corneal Injury: Anterior Segment Optical Coherence Tomography Study.

    Science.gov (United States)

    Zheng, Kang Keng; Cai, Jianhao; Rong, Shi Song; Peng, Kun; Xia, Honghe; Jin, Chuan; Lu, Xuehui; Liu, Xinyu; Chen, Haoyu; Jhanji, Vishal

    2017-07-01

    Ocular imaging can enhance our understanding of wound healing. We report anterior segment optical coherence tomography (ASOCT) findings in penetrating corneal injury. Serial ASOCT was performed after repair of penetrating corneal injury. Internal aberrations of wound edges were labeled as "steps" or "gaps" on ASOCT images. The wound type was characterized as: type 1: continuous inner wound edge or step height ≤ 80 µm; type 2: step height > 80 µm; type 3: gap between wound edges; and type 4: intraocular tissue adherent to wound. Surgical outcomes of different wound types were compared. 50 consecutive patients were included (6 females, 44 males; mean age 33 ± 12 years). The average size of wound was 4.2 ± 2.6 mm (type 1, 8 eyes; type 2, 27 eyes; type 3, 12 eyes; type 4, 3 eyes). At the end of 3 months, 70% (n = 35) of the wounds were type 1. At the end of 6 months, all type 1 wounds had healed completely, whereas about half of type 2 (48.1%) and type 3 (50%) wounds had recovered to type 1 configuration. The wound type at baseline affected the height of step (p = 0.047) and corneal thickness at 6 months (p = 0.035). ASOCT is a useful tool for monitoring wound healing in cases with penetrating corneal injury. Majority of the wound edges appose between 3 and 6 months after trauma. In our study, baseline wound configuration affected the healing pattern.

  11. Development of a novel oxirane-acrylate composite restorative resin material

    Science.gov (United States)

    Sripathi Panditaradhyula, Anuhya

    The need for resin with a long clinical life can be satiated through the novel formulation of varying concentrations of oxirane and acrylate monomers with an increase in filler loading in the sample, which will allow the creation of a resin that is less susceptible to chemical degradation along with improved mechanical properties. Various concentrations of oxirane and acrylate monomers with a three-component photoinitiation system, which is capable of both free radical (acrylate) and cationic (oxirane) initiation, are used. The resin composites were placed in the Speedmixer for 30 seconds and gravitation convection oven for one minute, repeated 5-7 times. The resin composites were used to create a 9.525 mm diameter * 1.5875 mm thick resin mold. The mold was then photocured for twenty seconds on both sides using VALO blue LED light. The Rockwell hardness and shore D durometer hardness served as relative measures of bonding between the monomers. The ideal formulation of oxirane and acrylate concentrations were used to perform the Instron 3 point bend test, as well as contact angle determination. The goal is to identify a resin with a clinical life twice that of the resins being used in practice. Potential findings include ideal oxirane and acrylate concentrations with the highest shore D durometer hardness, Rockwell hardness, contact angle values, and Instron 3 point bend test values. Ideal color, transparency and properties of the resin are taken into account. Optimization of oxirane and acrylate monomers, impact while using various filler components (salination, number of fillers), filler particle size variations and variations in using different filler concentrations are observed. Results of using micro and nano-sized monomers are also studied. Addition of fluorinated acrylate monomer to the micro and nano composite was the next goal. A comparison of all the above stated compositions to the control group 70/30 BisTEG was done. A study on the degradation behavior

  12. Edge passivation induced single-edge ferromagnetism of zigzag MoS_2 nanoribbons

    International Nuclear Information System (INIS)

    Wang, Rui; Sun, Hui; Ma, Ben; Hu, Jingguo; Pan, Jing

    2017-01-01

    We performed density functional theory study on electronic structure, magnetic properties and stability of zigzag MoS_2 nanoribbons (ZMoS_2NRs) with and without oxygen (O) passivation. The bare ZMoS_2NRs are magnetic metal with ferromagnetic edge states, edge passivation decreases their magnetism because of the decrease of edge unsaturated electrons. Obviously, the electronic structure and magnetic properties of ZMoS_2NRs greatly depend on edge states. When both edges are passivated by O atoms, ZMoS_2NRs are nonmagnetic metals. When either edge is passivated by O atoms, the systems exhibit single-edge ferromagnetism and magnetism concentrates on the non-passivated edge. Edge passivation can not only tune the magnetism of ZMoS_2NRs, but also enhance their stability by eliminating dangling bonds. These interesting findings on ZMoS_2NRs may open the possibility of their application in nanodevices and spintronics. - Highlights: • Edge passivation for tuning magnetism of zigzag MoS_2 nanoribbons (ZMoS_2NRs) is proposed. • Edge passivation can tune ZMoS_2NRs from nonmagnetic metal to ferromagnetic metal. • When either edge is passivated, the systems exhibit single-edge ferromagnetic states. • These findings may inspire great interest in the community of ZMoS_2NRs and motivate numerous experimental researches.

  13. Anterior tibial stress fractures treated with anterior tension band plating in high-performance athletes.

    Science.gov (United States)

    Cruz, Alexandre Santa; de Hollanda, João Paris Buarque; Duarte, Aires; Hungria Neto, José Soares

    2013-06-01

    The non-surgical treatment of anterior tibial cortex stress fractures requires long periods of abstention from sports activities and often results in non-union. Many different surgical techniques have already been previously described to treat these fractures, but there is no consensus on the best treatment. We describe the outcome of treatment using anterior tibial tension band plating in three high-performance athletes (4 legs) with anterior tibial cortex stress fractures. Tibial osteosynthesis with a 3.5-mm locking compression plate in the anterolateral aspect of the tibia was performed in all patients diagnosed with anterior tibial stress fracture after September 2010 at Santa Casa Hospital. All of the fractures were consolidated within a period of 3 months after surgery, allowing for an early return to pre-injury levels of competitive sports activity. There were no infection, non-union, malunion or anterior knee pain complications. Anterior tibial tension band plating leads to prompt fracture consolidation and is a good alternative for the treatment of anterior tibial cortex stress fractures. Bone grafts were shown to be unnecessary.

  14. Saturn's Rings Edge-on

    Science.gov (United States)

    1995-01-01

    In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

  15. Combination nivolumab- and cabiralizumab-associated acute bilateral anterior and posterior scleritis and anterior uveitis

    Directory of Open Access Journals (Sweden)

    John A. Gonzales

    2018-06-01

    Full Text Available Purpose: To report on a case of uveitis and scleritis resulting as an immune-mediated side effect of cancer immunotherapy with nivolumab and cabiralizumab. Observations: Bilateral anterior nongranulomatous anterior uveitis and bilateral diffuse anterior and posterior scleritis occurred following the use of combination cancer immunotherapy. The uveitis and scleritis resolved following temporary discontinuation of nivolumab and cabiralizumab as well as systemic prednisone. Conclusions and importance: Ophthalmologists should be aware of the possibility of acute ocular inflammation developing with cancer immunotherapy. Systemic corticosteroids play a first-line role in managing such immune-mediated side effects. Keywords: Uveitis, Scleritis, Cancer immunotherapy, Side effects, Nivolumab, Cabiralizumab

  16. Novel Insights into Anterior Cruciate Ligament Injury

    NARCIS (Netherlands)

    D.E. Meuffels (Duncan)

    2011-01-01

    textabstractAnterior cruciate ligament (ACL) injury is one of the most common sports injuries of the knee. ACL reconstruction has become, standard orthopaedic practice worldwide with an estimated 175,000 reconstructions per year in the United States.6 The ACL remains the most frequently studied

  17. Optical coherence tomography in anterior segment imaging

    Science.gov (United States)

    Kalev-Landoy, Maya; Day, Alexander C.; Cordeiro, M. Francesca; Migdal, Clive

    2008-01-01

    Purpose To evaluate the ability of optical coherence tomography (OCT), designed primarily to image the posterior segment, to visualize the anterior chamber angle (ACA) in patients with different angle configurations. Methods In a prospective observational study, the anterior segments of 26 eyes of 26 patients were imaged using the Zeiss Stratus OCT, model 3000. Imaging of the anterior segment was achieved by adjusting the focusing control on the Stratus OCT. A total of 16 patients had abnormal angle configurations including narrow or closed angles and plateau irides, and 10 had normal angle configurations as determined by prior full ophthalmic examination, including slit-lamp biomicroscopy and gonioscopy. Results In all cases, OCT provided high-resolution information regarding iris configuration. The ACA itself was clearly visualized in patients with narrow or closed angles, but not in patients with open angles. Conclusions Stratus OCT offers a non-contact, convenient and rapid method of assessing the configuration of the anterior chamber. Despite its limitations, it may be of help during the routine clinical assessment and treatment of patients with glaucoma, particularly when gonioscopy is not possible or difficult to interpret. PMID:17355288

  18. Treatment for acute anterior cruciate ligament tear

    DEFF Research Database (Denmark)

    Frobell, Richard B; Roos, Harald P; Roos, Ewa M

    2013-01-01

    To compare, in young active adults with an acute anterior cruciate ligament (ACL) tear, the mid-term (five year) patient reported and radiographic outcomes between those treated with rehabilitation plus early ACL reconstruction and those treated with rehabilitation and optional delayed ACL...

  19. Post caesarean section anterior abdominal wall endometriosis ...

    African Journals Online (AJOL)

    Abdominal wall endometriosis is a likely sequelae of caesarean section as viable endometrial tissue are deposited in the peritoneal cavity or anterior abdominal wall. One such case to sensitize clinicians of this rare presentation of the disease is presented. The patient was a 48 year old woman who presented with a lesion ...

  20. [Capsular retensioning in anterior unidirectional glenohumeral instability].

    Science.gov (United States)

    Benítez Pozos, Leonel; Martínez Molina, Oscar; Castañeda Landa, Ezequiel

    2007-01-01

    To present the experience of the Orthopedics Service PEMEX South Central Hospital in the management of anterior unidirectional shoulder instability with an arthroscopic technique consisting of capsular retensioning either combined with other anatomical repair procedures or alone. Thirty-one patients with anterior unidirectional shoulder instability operated-on between January 1999 and December 2005 were included. Fourteen patients underwent capsular retensioning and radiofrequency, and in 17 patients, capsular retensioning was combined with suture anchors. Patients with a history of relapsing glenohumeral dislocations and subluxations, with anterior instability with or without associated Bankart lesions were selected; all of them were young. The results were assessed considering basically the occurrence of instability during the postoperative follow-up. No cases of recurring instability occurred. Two cases had neuroma and one experienced irritation of the suture site. Six patients had residual limitation of combined lateral rotation and abduction movements, of a mean of 10 degrees compared with the healthy contralateral side. The most frequent incident was the leak of solutions to the soft tissues. Capsular retensioning, whether combined or not with other anatomical repair techniques, has proven to result in a highly satisfactory rate of glenohumeral stabilization in cases of anterior unidirectional instabilities. The arthroscopic approach offers the well-known advantages of causing less damage to the soft tissues, and a shorter time to starting rehabilitation therapy and exercises.

  1. Tunnel widening in anterior cruciate ligament reconstruction

    DEFF Research Database (Denmark)

    Clatworthy, M G; Annear, P; Bulow, J U

    1999-01-01

    We report a prospective series evaluating the incidence and degree of tunnel widening in a well-matched series of patients receiving a hamstring or patella tendon graft for anterior cruciate ligament (ACL) deficiency. We correlated tunnel widening with clinical factors, knee scores, KT-1000 and i...

  2. Anterior interbody fusion for cervical osteomyelitis

    Science.gov (United States)

    Bartal, A. D.; Schiffer, J.; Heilbronn, Y. D.; Yahel, M.

    1972-01-01

    Interbody fusion for stabilization of the cervical spine after osteomyelitic destruction of the body of C5 vertebra is reported in a patient with quadriplegia and sphincter disturbances secondary to an epidural abscess. The successful union of the bone graft along with complete neurological recovery after anterior decompression and evacuation of the epidural mass seem to justify the procedure. Images PMID:4554587

  3. Anterior process fractures of the calcaneus

    International Nuclear Information System (INIS)

    Renfrew, D.L.; El-Khoury, G.Y.

    1985-01-01

    Fractures of the anterior process of the calcaneus are often missed. This error follows from the tendency to focus exclusively on the mortise and malleoli when a history of ankle trauma is supplied. Seven patients with this fracture are presented. The anatomy, mechanism of injury, clinical presentation, and the radiographic features of this injury are discussed. (orig.)

  4. Cytological organization of the alpha component of the anterior olfactory nucleus and olfactory limbus

    Directory of Open Access Journals (Sweden)

    Jorge A Larriva-Sahd

    2012-06-01

    Full Text Available This study describes the microscopic organization of a wedge-shaped area at the intersection of the main and accessory olfactory bulbs, or olfactory limbus , and an additional component of the anterior olfactory nucleus or alpha accessory olfactory bulb that lies underneath of the accessory olfactory bulb. The olfactory limbus consists of a modified bulbar cortex bounded anteriorly by the main olfactory bulb and posteriorly by the accessory olfactory bulb. In Nissl-stained specimens the olfactory limbus differs from the main olfactory bulb by a progressive, antero-posterior decrease in thickness or absence of the external plexiform, mitral/tufted cell, and granule cell layers. On cytoarchitectual grounds the olfactory limbus is divided from rostral to caudal into three distinct components: a stripe of glomerular-free cortex or preolfactory area, a second or necklace glomerular area, and a wedge-shaped or interstitial area crowned by the so-called modified glomeruli that appear to belong to the anterior accessory olfactory bulb. The strategic location and interactions with the main and accessory olfactory bulbs, together with the previously noted functional and connectional evidence, suggest that the olfactory limbus may be related to both sensory modalities. The alpha component of the anterior olfactory nucleus, a slender cellular cluster (i.e., 650 x 150 µm paralleling the base of the accessory olfactory bulb, contains two neuron types: a pyramidal-like neuron and an interneuron. Dendrites of pyramidal-like cells organize into a single bundle that ascends avoiding the accessory olfactory bulb to resolve in a trigone bounded by the edge of the olfactory limbus, the accessory olfactory bulb and the dorsal part of the anterior olfactory nucleus. Utrastructurally, the neuropil of the alpha component contains three types of synaptic terminals; one of them immunoreactive to the enzyme glutamate decarboxylase, isoform 67.

  5. Competitive edge through technological innovation

    International Nuclear Information System (INIS)

    Gottlieb, M.

    1997-01-01

    The vital role of advanced technology in natural gas cost reduction has been described. Among advanced technologies, seismic, drilling and fracturing technologies have been singled out as being the most important. Access to new supply frontiers (aided by the application of advanced technology), and more effective business strategies were considered as the other most influential factors in efficiently exploiting oil and gas resources. In view of predictions of substantially increased demand, advanced technology is poised to be even more important in the future. With this as background, an examination of the level of investment for the development of advanced technology revealed that energy industry R and D expenditures were lowest among industries in the U.S. (only 0.7 per cent of sales). It was concluded that notwithstanding industry's ability to improve output per R and D dollar invested, the achievement of the necessary technological advancements is a strategic imperative for both the industry and the U.S. as a whole. As far as the industry is concerned, its ability to maintain a competitive edge over competing energy forms, will be determined largely on the basis of its willingness to invest in future advanced technology development. 2 refs., 14 figs

  6. CMS kinematic edge from sbottoms

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Peisi; Wagner, Carlos E. M.

    2015-01-01

    We present two scenarios in the Minimal Supersymmetric Extension of the Standard Model (MSSM) that can lead to an explanation of the excess in the invariant mass distribution of two opposite charged, same flavor leptons, and the corresponding edge at an energy of about 78 GeV, recently reported by the CMS Collaboration. In both scenarios, sbottoms are pair produced, and decay to neutralinos and a b-jet. The heavier neutralinos further decay to a pair of leptons and the lightest neutralino through on-shell sleptons or off-shell neutral gauge bosons. These scenarios are consistent with the current limits on the sbottoms, neutralinos, and sleptons. Assuming that the lightest neutralino is stable we discuss the predicted relic density as well as the implications for darkmatter direct detection. We show that consistency between the predicted and the measured value of the muon anomalous magnetic moment may be obtained in both scenarios. Finally, we define the signatures of these models that may be tested at the 13 TeV run of the LHC

  7. Anterior Segment Ischemia after Strabismus Surger

    Directory of Open Access Journals (Sweden)

    Emine Seyhan Göçmen

    2017-01-01

    Full Text Available A 46-year-old male patient was referred to our clinic with complaints of diplopia and esotropia in his right eye that developed after a car accident. The patient had right esotropia in primary position and abduction of the right eye was totally limited. Primary deviation was over 40 prism diopters at near and distance. The patient was diagnosed with sixth nerve palsy and 18 months after trauma, he underwent right medial rectus muscle recession. Ten months after the first operation, full-thickness tendon transposition of the superior and inferior rectus muscles (with Foster suture was performed. On the first postoperative day, slit-lamp examination revealed corneal edema, 3+ cells in the anterior chamber and an irregular pupil. According to these findings, the diagnosis was anterior segment ischemia. Treatment with 0.1/5 mL topical dexamethasone drops (16 times/day, cyclopentolate hydrochloride drops (3 times/day and 20 mg oral fluocortolone (3 times/day was initiated. After 1 week of treatment, corneal edema regressed and the anterior chamber was clean. Topical and systemic steroid treatment was gradually discontinued. At postoperative 1 month, the patient was orthophoric and there were no pathologic symptoms besides the irregular pupil. Anterior segment ischemia is one of the most serious complications of strabismus surgery. Despite the fact that in most cases the only remaining sequel is an irregular pupil, serious circulation deficits could lead to phthisis bulbi. Clinical properties of anterior segment ischemia should be well recognized and in especially risky cases, preventative measures should be taken.

  8. Hierarchically organized architecture of potassium hydrogen phthalate and poly(acrylic acid): toward a general strategy for biomimetic crystal design.

    Science.gov (United States)

    Oaki, Yuya; Imai, Hiroaki

    2005-12-28

    A hierarchically organized architecture in multiple scales was generated from potassium hydrogen phthalate crystals and poly(acrylic acid) based on our novel biomimetic approach with an exquisite association of polymers on crystallization.

  9. Perawatan Ortodontik Gigi Anterior Berjejal dengan Tulang Alveolar yang Tipis

    Directory of Open Access Journals (Sweden)

    Miesje K. Purwanegara

    2015-09-01

    Full Text Available Anterior teeth movement in orthodontic treatment is limited to labiolingual direction by very thin alveolar bone. An uncontrolled anterior tooth movement to labiolingual direction can cause alveolar bone perforation at its root segment. This case report is to remind us that alveolar bone thickness limits orthodontc tooth movement. A case of crowded anterior teeth with thin alveolar bone in malocclusion I is reported. This case is treated using adgewise orthodontic appliance. Protraction of anterior teeth is anticipated due to thin alveolar bone on the anterior surface. The conclusion is although the alveolar bone surrounding the crowded anterior teeth is thin, by controlling the movement the teeth reposition is allowed.

  10. LES tests on airfoil trailing edge serration

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Shen, Wen Zhong

    2016-01-01

    In the present study, a large number of acoustic simulations are carried out for a low noise airfoil with different Trailing Edge Serrations (TES). The Ffowcs Williams-Hawkings (FWH) acoustic analogy is used for noise prediction at trailing edge. The acoustic solver is running on the platform...

  11. Automatic Edging and Trimming of Hardwood Lumber

    Science.gov (United States)

    D. Earl Kline; Eugene M. Wengert; Philip A. Araman

    1990-01-01

    Studies have shown that there is a potential to increase hardwood lumber value by more than 20 percent through optimum edging and trimming. Even a small portion of this percentage can boost the profitability of hardwood lumber manufacturers substantially. The objective of this research project is to develop an automated system which would assist in correct edging and...

  12. Development of planar detectors with active edge

    International Nuclear Information System (INIS)

    Povoli, M.; Bagolini, A.; Boscardin, M.; Dalla Betta, G.-F.; Giacomini, G.; Vianello, E.; Zorzi, N.

    2011-01-01

    We report on the first batch of planar active edge sensors fabricated at Fondazione Bruno Kessler (Trento, Italy) on the way to the development of full 3D detectors with active edges. The main design and technological aspects are reported, along with selected results from the electrical characterization of detectors and test structures.

  13. Development of planar detectors with active edge

    Energy Technology Data Exchange (ETDEWEB)

    Povoli, M., E-mail: povoli@disi.unitn.it [Dipartimento di Ingegneria e Scienza dell' Informazione, Universita di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento) (Italy); Bagolini, A.; Boscardin, M. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy); Dalla Betta, G.-F. [Dipartimento di Ingegneria e Scienza dell' Informazione, Universita di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento) (Italy); Giacomini, G.; Vianello, E.; Zorzi, N. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy)

    2011-12-01

    We report on the first batch of planar active edge sensors fabricated at Fondazione Bruno Kessler (Trento, Italy) on the way to the development of full 3D detectors with active edges. The main design and technological aspects are reported, along with selected results from the electrical characterization of detectors and test structures.

  14. Annotated Bibliography of EDGE2D Use

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Strachan and G. Corrigan

    2005-06-24

    This annotated bibliography is intended to help EDGE2D users, and particularly new users, find existing published literature that has used EDGE2D. Our idea is that a person can find existing studies which may relate to his intended use, as well as gain ideas about other possible applications by scanning the attached tables.

  15. Annotated Bibliography of EDGE2D Use

    International Nuclear Information System (INIS)

    Strachan, J.D.; Corrigan, G.

    2005-01-01

    This annotated bibliography is intended to help EDGE2D users, and particularly new users, find existing published literature that has used EDGE2D. Our idea is that a person can find existing studies which may relate to his intended use, as well as gain ideas about other possible applications by scanning the attached tables

  16. Magnetism of zigzag edge phosphorene nanoribbons

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zhili, E-mail: zlzhu@zzu.edu.cn, E-mail: jiayu@zzu.edu.cn; Li, Chong; Yu, Weiyang; Chang, Dahu; Sun, Qiang; Jia, Yu, E-mail: zlzhu@zzu.edu.cn, E-mail: jiayu@zzu.edu.cn [International Joint Research Laboratory for Quantum Functional Materials of Henan, and School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001 (China)

    2014-09-15

    We have investigated, by means of ab initio calculations, the electronic and magnetic structures of zigzag edge phosphorene nanoribbons (ZPNRs) with various widths. The stable magnetic state was found in pristine ZPNRs by allowing the systems to be spin-polarized. The ground state of pristine ZPNRs prefers ferromagnetic order in the same edge but antiferromagnetic order between two opposite edges. The magnetism arises from the dangling bond states as well as edge localized π-orbital states. The presence of a dangling bond is crucial to the formation of the magnetism of ZPNRs. The hydrogenated ZPNRs get nonmagnetic semiconductors with a direct band gap. While, the O-saturated ZPNRs show magnetic ground states due to the weak P-O bond in the ribbon plane between the p{sub z}-orbitals of the edge O and P atoms.

  17. Edge separation using diffraction anomalous fine structure

    International Nuclear Information System (INIS)

    Ravel, B.; Bouldin, C.E.; Renevier, H.; Hodeau, J.L.; Berar, J.F.

    1999-01-01

    We exploit the crystallographic sensitivity of the Diffraction Anomalous Fine-Structure (DAFS) measurement to separate the fine structure contributions of different atomic species with closely spaced resonant energies. In BaTiO 3 the Ti K edge and Ba Lm edges are separated by 281 eV, or about 8.2 Angstrom -1 ), thus severely limiting the information content of the Ti K edge signal. Using the site selectivity of DAFS we can separate the two fine structure spectra using an iterative Kramers-Kronig method, thus extending the range of the Ti K edge spectrum. This technique has application to many rare earth/transition metal compounds, including many magnetic materials of technological significance for which K and L edges overlap in energy. (au)

  18. Controlled radical polymerization of acrylates by {gamma}-irradiation in the presence of 1,1-diphenylethene

    Energy Technology Data Exchange (ETDEWEB)

    Wu Zongtao [Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang Zhicheng [Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)]. E-mail: zczhang@ustc.edu.cn

    2005-12-15

    Poly (butyl acrylate) and poly (methyl acrylate) were successfully prepared in the presence of 1,1-diphenylethene (DPE) by {gamma}-irradiation-induced polymerization in both bulk and solution. The influences of polymerization time, amounts of DPE in system on conversion, molecular weight (MW) and its distribution (M{sub w}/M{sub n}) were studied. The results indicate that the polymerization initiated by {gamma}-irradiation in the presence of DPE shows the character of living radical reaction.

  19. Emulsion Polymerization of Etyl Acrylate: The Effect of Surfactant, Initiator Concentration and PolymerizationTechnique on Particle Size Distribution

    OpenAIRE

    Nitri Arinda; Emil Budianto; Helmiyati

    2009-01-01

    Emulsion polymerization was conducted using ethyl acrylate monomer. Theeffect of sodium lauryl sulfate concentration, ammonium persulfate concentration, the various of polymerizationtechniques and feeding time to the conversion, particle size and its distribution were observed. The purpose of thisresearch is to obtain the optimum condition of ethyl acrylate homopolymer with particle size around 100 nm, to get theparticle size distribution monodisperse and to get solid content value of the exp...

  20. Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction

    OpenAIRE

    Saed, Mohand O.; Torbati, Amir H.; Nair, Devatha P.; Yakacki, Christopher M.

    2016-01-01

    This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline elastomers (LCEs) with facile control over network structure and programming of an aligned monodomain. Tailored LCE networks were synthesized using routine mixing of commercially available starting materials and pouring monomer solutions into molds to cure. An initial polydomain LCE network is formed via a self-limiting thiol-acrylate Michael-addi...