WorldWideScience

Sample records for source category veneer

  1. 40 CFR 98.410 - Definition of the source category.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Industrial Greenhouse Gases § 98.410 Definition of the source category. (a) The industrial gas supplier source category consists of any facility that...

  2. 40 CFR 98.110 - Definition of the source category.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ferroalloy Production § 98.110 Definition of the source category. The ferroalloy production source category consists of any facility that uses pyrometallurgical techniques to produce any of the following metals: ferrochromium, ferromanganese, ferromolybdenum...

  3. 6 Source Categories - Boilers (Proposed Action)

    Science.gov (United States)

    EPA is proposing options to simplify the Clean Air Act permitting process for certain smaller sources of air pollution commonly found in Indian country. This action would ensure that air quality in Indian country is protected.

  4. 40 CFR 98.360 - Definition of the source category.

    Science.gov (United States)

    2010-07-01

    ... this rule. (b) A manure management system (MMS) is a system that stabilizes and/or stores livestock... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Manure Management § 98.360 Definition of the source category. (a) This source category consists of livestock facilities with manure management systems that emit 25...

  5. 40 CFR 98.70 - Definition of source category.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Definition of source category. 98.70... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.70 Definition of source category...-based feedstock produced via steam reforming of a hydrocarbon. (b) Ammonia manufacturing processes in...

  6. 40 CFR 98.40 - Definition of the source category.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Definition of the source category. 98... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electricity Generation § 98.40 Definition of the source... category does not include portable equipment, emergency equipment, or emergency generators, as defined in...

  7. Arab Societal Awareness of Dental Veneers.

    Science.gov (United States)

    Alfouzan, Afnan; Al-Sanie, Aisha A; Al-Dhafiri, Reem A

    2018-03-01

    The aim of this study is to assess the Arab society's knowledge, awareness, and attitudes toward dental veneers. A cross-sectional study was performed by collecting data through an online questionnaire created using the Survey Monkey website and distributed among Middle Eastern societies through social media to ascertain participants' knowledge and awareness regarding dental veneers. The sample included Arab laypeople who were over 18 years old, to represent the awareness of the majority regarding dental veneers. The sample of this study included 1,332 subjects from different Middle Eastern nationalities, mainly Saudis, Kuwaitis, and Emiratis (15.6% of males and 84.4% of females). The results of this study showed that the total knowledge of dental veneers is 50.12%. The respondents with the highest level of knowledge acquired their information mainly from newspapers and magazines, followed by the Internet, then dentists, then social media, and, finally, friends and relatives. Cost was the only factor limiting 38.4% of subjects from receiving veneers, and 56% of the subjects would receive veneers if they were free of cost. In total, 72.6% of the respondents believed that veneers are currently overused. The knowledge and awareness of dental veneers were below a satisfactory level. Participants who relied on social media as a source of information had lower knowledge levels. This study emphasized the need for continual societal education regarding dental veneers.

  8. 40 CFR 98.420 - Definition of the source category.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Definition of the source category. 98.420 Section 98.420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... distribution of CO2. (4) Purification, compression, or processing of CO2. (5) On-site use of CO2 captured on...

  9. Task-Modulated Cortical Representations of Natural Sound Source Categories

    DEFF Research Database (Denmark)

    Hjortkjær, Jens; Kassuba, Tanja; Madsen, Kristoffer Hougaard

    2018-01-01

    In everyday sound environments, we recognize sound sources and events by attending to relevant aspects of an acoustic input. Evidence about the cortical mechanisms involved in extracting relevant category information from natural sounds is, however, limited to speech. Here, we used functional MRI...

  10. 40 CFR 98.240 - Definition of the source category.

    Science.gov (United States)

    2010-07-01

    ... makes methanol, hydrogen, and/or ammonia from synthesis gas is part of the petrochemical source category... hydrogen recovered as product and ammonia. The facility is part of subpart P of this part (Hydrogen... levels of both methanol and ammonia. The facility is part of subpart G of this part (Ammonia...

  11. 76 FR 4155 - National Emission Standards for Hazardous Air Pollutants for Source Categories: Gasoline...

    Science.gov (United States)

    2011-01-24

    ... 63 National Emission Standards for Hazardous Air Pollutants for Source Categories: Gasoline Distribution Bulk Terminals, Bulk Plants, and Pipeline Facilities; and Gasoline Dispensing Facilities; Final...] RIN 2060-AP16 National Emission Standards for Hazardous Air Pollutants for Source Categories: Gasoline...

  12. Preliminary data summary for the hospitals point-source category

    International Nuclear Information System (INIS)

    Strassler, E.; Hund, F.H.

    1989-09-01

    The summaries were prepared in order to allow EPA to respond to the mandate of Section 304(m) of the Clean Water Act. Summaries for categories already subject to rulemaking were developed for comparison purposes, and contain only the minimum amount of data needed to provide some perspective on the relative magnitude of the pollution problems created across the categories. The document summarizes the most current information available regarding the discharge of wastewater and solid wastes containing priority and hazardous non-priority pollutants by hospitals. The document provides a technical basis for determining whether additional national regulations should be developed pursuant to the Clean Water Act (CWA), and makes available preliminary information regarding the discharge of priority and hazardous non-priority pollutants by the hospital industry

  13. Tactics at the category level of purchasing and supply management: sourcing levers, contingencies and performance

    OpenAIRE

    Hesping, Frank

    2015-01-01

    For the ‘front-line’ purchasing agent, it is obvious that not all categories of products and supplier relationships should be managed in the same way. Rather, in a modern category management approach, firms group similar products into ‘sourcing categories’ forming coherent supply markets (e.g., ‘metal sheets’, ‘leather’, ‘displays’, ‘cables’, etc.). Thus, to achieve cost reduction targets, a tailored mix of tactical sourcing levers for each sourcing category may be required. The fundamental q...

  14. The Role of External Sources of Information in Children's Evaluative Food Categories

    Science.gov (United States)

    Nguyen, Simone P.

    2012-01-01

    Evaluative food categories are value-laden assessments, which reflect the healthfulness and palatability of foods (e.g. healthy/unhealthy, yummy/yucky). In a series of three studies, this research examines how 3- to 4-year-old children (N?=?147) form evaluative food categories based on input from external sources of information. The results…

  15. Tactics at the category level of purchasing and supply management: sourcing levers, contingencies and performance

    NARCIS (Netherlands)

    Hesping, Frank

    2015-01-01

    For the ‘front-line’ purchasing agent, it is obvious that not all categories of products and supplier relationships should be managed in the same way. Rather, in a modern category management approach, firms group similar products into ‘sourcing categories’ forming coherent supply markets (e.g.,

  16. 77 FR 11390 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories; Nevada

    Science.gov (United States)

    2012-02-27

    ... Source Categories. Subpart ZZZZZZ--NESHAP: Area Source Standards for Aluminum, Copper, and Other... Perchloroethylene Dry X X X Cleaning. N Hard and Decorative X X X Chromium Electroplating and Chromium Anodizing... Publishing X X X Industry. LL Primary Aluminum Reduction X X Plants. MM Chemical Recovery X X Combustion...

  17. 40 CFR Table 1 to Subpart Xxxxxx... - Description of Source Categories Affected by This Subpart

    Science.gov (United States)

    2010-07-01

    ... heating units, combination gas-oil burners, oil or gas swimming pool heaters, heating apparatus (except... supplies industry sector of this source category includes establishments primarily engaged in high energy...), coke and gas burning salamanders, liquid or gas solar energy collectors, solar heaters, space heaters...

  18. Current status of securing Category 1 and 2 radioactive sources in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Y-F.; Tsai, C-H. [Atomic Energy Council of Executive Yuan of Taiwan (China)

    2014-07-01

    For enhancing safe and secure management of Category 1 and 2 radioactive sources against theft or unauthorized removal, AEC (Atomic Energy Council) of Taiwan have been regulating the import/export of the sources ever since 2005, in compliance with the IAEA's (International Atomic Energy Agency) 'Guidance on the Import and Export of Radioactive Sources'. Furthermore in consulting the IAEA Nuclear Security Series No.11 report, administrative regulations on the program of securing the sources have been embodied into AECL's regulatory system since 2012, for the purpose of enforcing medical and non-medical licensees and industrial radiographers to establish their own radioactive source security programs. Regulations require that security functions such as access control, detection, delay, response and communication and security management measures are to be implemented within the programs. This paper is to introduce the current status in implementing the security control measures in Taiwan. (author)

  19. Western hemlock as a veneer resource.

    Science.gov (United States)

    Thomas D. Fahey; Jr. Woodfin

    1982-01-01

    Presents recovery of veneer grade and volume from western hemlock from Oregon and Washington. Veneer grade recovery varied by grade and size of logs. Veneer volume recovered was about 45 percent of the cubic volume of the log and varied somewhat with log diameter.

  20. Safety issues in the handling of radiation sources in category IV gamma radiation facilities

    International Nuclear Information System (INIS)

    Kohli, A.K.

    2002-01-01

    There is potential for incidents/accidents related to handling of radiation sources. This is increasing due to the fact that more number of plants that too with much larger levels of activity are now coming up. Such facilities produce very high levels of exposure rates during irradiation. A person accidentally present in the irradiation cell can receive a lethal dose within a very short time. Apart from safety requirements during operation and maintenance of these facilities, safety during loading and unloading of sources is important. Category IV type irradiators are the most common. Doubly encapsulated Co-60 slugs are employed to form the source pencils. These irradiators employ a water pool for safely storing the source pencils when irradiation of the products is not going on or when human access is needed into the irradiation cell for some maintenance or source loading/unloading operations. Safety during loading/unloading operations of source pencils is important. In design itself care needs to be taken such that all such operations are convenient and any incident will not lead to a situation where it becomes difficult to come out. Different situations, which can arise during handling of radiation sources and suggested designs to obviate such tight situations, are discussed. (Author)

  1. Influence of Thinning and Pruning on Southern Pine Veneer Quality

    Science.gov (United States)

    Mark D. Gibson; Terry R. Clason; Gary L. Hill; George A. Grozdits

    2002-01-01

    This paper presents the effects of intensive pine plantation management on veneer yields, veneer grade distribution and veneer MOE as measured by ultrasonic stress wave transmission (Metriguard). Veneer production trials were done at a commercial southern pine plywood plant to elucidate the effects of silvicultural treatments on veneer quality, yield, and modulus of...

  2. UV curing of teak veneers for decorative panel

    International Nuclear Information System (INIS)

    Gatot Trimulyadi Rekso; Darsono

    1999-01-01

    The radiation curing of surface coating of teak veneers for decorative panels has been conducted by using ultra violet (UV) as radiation source. In this experiment teak wood veneer was use as a substrate. Epoxy acrylate (import product,) and unsaturated polyester (locally product) were used as coating materials after being added with difunctional monomer TPGDA, and photo-initiator darocur 1173 or irgacure 184. Irradiation was conducted using 80 watt/cm LTV source at conveyor speed of 3,0 m/min. Parameters observed were viscosity of coating materials, hardness, adhesion, appearance, abrasion and chemical resistance of cured films. In general the results showed that viscosity of the formulations based on epoxy acrylate and unsaturated polyester resin were effected by the storage. Film cured by LTV made of epoxy acrylate and unsaturated polyester on the teak veneer wood have the same adhesion and abrasion resistant properties but the hardness and chemical resistant of epoxy acrylate are better than unsaturated polyester. From the experiment result it can be concluded the unsaturated polyester (locally product) can be used as radiation curable material for coating teak veneer panels

  3. Anthropogenic Sulfur Dioxide Emissions, 1850-2005: National and Regional Data Set by Source Category, Version 2.86

    Data.gov (United States)

    National Aeronautics and Space Administration — The Anthropogenic Sulfur Dioxide Emissions, 1850-2005: National and Regional Data Set by Source Category, Version 2.86 provides annual estimates of anthropogenic...

  4. Defining Hardwood Veneer Log Quality Attributes

    Science.gov (United States)

    Jan Wiedenbeck; Michael Wiemann; Delton Alderman; John Baumgras; William Luppold

    2004-01-01

    This publication provides a broad spectrum of information on the hardwood veneer industry in North America. Veneer manufacturers and their customers impose guidelines in specifying wood quality attributes that are very discriminating but poorly defined (e.g., exceptional color, texture, and/or figure characteristics). To better understand and begin to define the most...

  5. Anaerobic biodegradability of Category 2 animal by-products: methane potential and inoculum source.

    Science.gov (United States)

    Pozdniakova, Tatiana A; Costa, José C; Santos, Ricardo J; Alves, M M; Boaventura, Rui A R

    2012-11-01

    Category 2 animal by-products that need to be sterilized with steam pressure according Regulation (EC) 1774/2002 are studied. In this work, 2 sets of experiments were performed in mesophilic conditions: (i) biomethane potential determination testing 0.5%, 2.0% and 5.0% total solids (TS), using sludge from the anaerobic digester of a wastewater treatment plant as inoculum; (ii) biodegradability tests at a constant TS concentration of 2.0% and different inoculum sources (digested sludge from a wastewater treatment plant; granular sludge from an upflow anaerobic sludge blanket reactor; leachate from a municipal solid waste landfill; and sludge from the slaughterhouse wastewater treatment anaerobic lagoon) to select the more adapted inoculum to the substrate in study. The higher specific methane production was of 317 mL CH(4)g(-1) VS(substrate) for 2.0% TS. The digested sludge from the wastewater treatment plant led to the lowest lag-phase period and higher methane potential rate. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Journey of a Package: Category 1 Source (Co-60) Shipment with Several Border Crossings, Multiple Modes

    International Nuclear Information System (INIS)

    Gray, P. A.

    2016-01-01

    Radioactive materials (RAM) are used extensively in a vast array of industries and in an even wider breadth of applications on a truly global basis each and every day. Over the past 50 years, these applications and the quantity (activity) of RAM shipped has grown significantly, with the next 50 years expected to show a continuing trend. The movement of these goods occurs in all regions of the world, and must therefore be conducted in a manner which will not adversely impact people or the environment. Industry and regulators have jointly met this challenge, so much so that RAM shipments are amongst the safest of any product. How has this level of performance been achieved? What is involved in shipping RAM from one corner of the world to another, often via a number of in-transit locations and often utilizing multiple modes of transport in any single shipment? This paper reviews one such journey, of Category 1 Cobalt-60 sources, as they move from point of manufacture through to point of use including the detailed and multi-approval process, the stringent regulatory requirements in place, the extensive communications required throughout, and the practical aspects needed to simply offer such a product for sale and transport. Upon completion, the rationale for such an exemplary safety and security record will be readily apparent. (author)

  7. Flexural properties of laminated veneer lumber manufactured from ultrasonically rated red maple veneer : a pilot study.

    Science.gov (United States)

    Xiping Wang; Robert J. Ross; Brian K. Brashaw; Steven A. Verhey; John W. Forsman; John R. Erickson

    2003-01-01

    The study described in this report was conducted to examine the flexural properties of laminated veneer lumber (LVL) manufactured from red maple veneer. Ultrasonically rated veneer, which was peeled from low value red maple saw-logs, was fabricated into 1/2-in.-(1.3-cm-) and 2-in.-(5-cm-) thick LVL billets. The flexural properties of the billets and of corresponding...

  8. Spectral and temporal cues for perception of material and action categories in impacted sound sources

    DEFF Research Database (Denmark)

    Hjortkjær, Jens; McAdams, Stephen

    2016-01-01

    In two experiments, similarity ratings and categorization performance with recorded impact sounds representing three material categories (wood, metal, glass) being manipulated by three different categories of action (drop, strike, rattle) were examined. Previous research focusing on single impact...... correlated with the pattern of confusion in categorization judgments. Listeners tended to confuse materials with similar spectral centroids, and actions with similar temporal centroids and onset densities. To confirm the influence of these different features, spectral cues were removed by applying...

  9. Veneers

    Science.gov (United States)

    ... in many situations. They provide a much more conservative approach to changing a tooth's color, size or ... See Flaws Home | InfoBites | Find a Dentist | Your Family's Oral Health | RSS About AGD | Contact AGD | Site ...

  10. The clinical microscope and direct composite veneer

    DEFF Research Database (Denmark)

    Pascotto, Renata C; Benetti, Ana Raquel

    2010-01-01

    This paper presents the advantages and limitations related to the use of a clinical microscope in restorative dentistry, and it demonstrates the aid of magnification during preparation and restoration of a direct composite veneer. Good illumination and visibility is important to adequately viewin...... the adjacent dental tissues so that the resin composite buildup can mimic natural teeth. The reproduction of details results in a naturally esthetic direct veneer....

  11. Production of laminated veneer lumber LVL using veneer of Schizolobium amazonicum, Eucalyptus saligna and Pinus taeda

    Directory of Open Access Journals (Sweden)

    Setsuo Iwakiri

    2010-12-01

    Full Text Available This research evaluated the quality of laminated veneer lumber - LVL manufactured with veneers of Schizolobium amazonicum (paricá, Eucalyptus saligna and Pinus taeda. The LVL panels were manufactured in the laboratory conditions composed by seven veneers, 2,0 mm thickness, with different structural compositions, using phenol-formaldehyde resin. The veneers of Schizolobium amazonicum- paricá- were pre-classified by using stress wave machine. The veneers of Eucalyptus saligna and Pinus taeda were disposed in the face layer to reinforce the structural strength of LVL panels. The LVL quality was evaluated using glue line shear strength and static bending test (MOE and MOR, edge and flat. Grading of paricá veneers based on MOEd did not affected significantly the results of the glue line shear strength and MOE and MOR edge. For the MOE and MOR flat, the use of veneers of MOEd grade 1 contributed significantly to increasing the average values of these properties. In the same way, using the Eucalyptus saligna veneers on the face of LVL resulted in higher average values of MOE and MOR, edge and flat.

  12. Influence of veneer thickness on residual stress profile in veneering ceramic: measurement by hole-drilling.

    Science.gov (United States)

    Mainjot, Amélie K; Schajer, Gary S; Vanheusden, Alain J; Sadoun, Michaël J

    2012-02-01

    The veneering process of frameworks induces residual stresses and can initiate cracks when combined with functional stresses. The stress distribution within the veneering ceramic as a function of depth is a key factor influencing failure by chipping. This is a well-known problem with Yttria-tetragonal-zirconia-polycrystal based fixed partial dentures. The objective of this study is to investigate the influence of veneer thickness on the stress profile in zirconia- and metal-based structures. The hole-drilling method, often used for engineering measurements, was adapted for use with veneering ceramic. The stress profile was measured in bilayered disc samples of 20 mm diameter, with a 1 mm thick zirconia or metal framework. Different veneering ceramic thicknesses were performed: 1 mm, 1.5 mm, 2 mm, 2.5 mm and 3 mm. All samples exhibited the same type of stress vs. depth profile, starting with compressive at the ceramic surface, decreasing with depth up to 0.5-1.0 mm from the surface, and then becoming compressive again near the framework, except for the 1.5 mm-veneered zirconia samples which exhibited interior tensile stresses. Stresses in the surface of metal samples were not influenced by veneer thickness. Variation of interior stresses at 1.2 mm from the surface in function of veneer thickness was inverted for metal and zirconia samples. Veneer thickness influences in an opposite way the residual stress profile in metal- and in zirconia-based structures. A three-step approach and the hypothesis of the crystalline transformation are discussed to explain the less favorable residual stress development in zirconia samples. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  13. Effect of core/veneer thickness ratio and veneer translucency on absolute and relative translucency of CAD-On restorations

    Directory of Open Access Journals (Sweden)

    Mennatallah Mohie el-Din Wahba, (BDS, MSc

    2017-06-01

    Conclusions: Only veneer translucency had significant effect over contrast ratio values, while on the other hand, absolute translucency values were significantly affected by the core/veneer thickness ratio, veneer translucency and interaction between them. It was clear that absolute translucency measurements showed higher translucency values for the restorations than contrast ratio measurements.

  14. [Veneer computer aided design based on reverse engineering technology].

    Science.gov (United States)

    Liu, Ming-li; Chen, Xiao-dong; Wang, Yong

    2012-03-01

    To explore the computer aided design (CAD) method of veneer restoration, and to assess if the solution can help prosthesis meet morphology esthetics standard. A volunteer's upper right central incisor needed to be restored with veneer. Super hard stone models of patient's dentition (before and after tooth preparation) were scanned with the three-dimensional laser scanner. The veneer margin was designed as butt-to-butt type. The veneer was constructed using reverse engineering (RE) software. The technique guideline of veneers CAD was explore based on RE software, and the veneers was smooth, continuous and symmetrical, which met esthetics construction needs. It was a feasible method to reconstruct veneer restoration based on RE technology.

  15. Methodologies for estimating air emissions from three non-traditional source categories: Oil spills, petroleum vessel loading and unloading, and cooling towers. Final report, October 1991-March 1993

    International Nuclear Information System (INIS)

    Ramadan, W.; Sleva, S.; Dufner, K.; Snow, S.; Kersteter, S.L.

    1993-04-01

    The report discusses part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plan (SIP) area source methodologies and to develop appropriate emissions estimation methodologies and emission factors for a group of these source categories. Based on the results of the identification and characterization portions of this research, three source categories were selected for methodology and emission factor development: oil spills, petroleum vessel loading and unloading, and cooling towers. The report describes the category selection process and presents emissions estimation methodologies and emission factor data for the selected source categories. The discussions for each category include general background information, emissions generation activities, pollutants emitted, sources of activity and pollutant data, emissions estimation methodologies and data issues. The information used in these discussions was derived from various sources including available literature, industrial and trade association publications and contracts, experts on the category and activity, and knowledgeable federal and state personnel

  16. An indirect veneer technique for simple and esthetic treatment of anterior hypoplastic teeth

    Directory of Open Access Journals (Sweden)

    Amit Khatri

    2010-01-01

    Full Text Available This study describes a technique for treating anterior hypoplastic teeth using indirect nanocomposite veneer restoration. The prime advantage of an indirect veneer technique is that it provides an esthetic and conservative result. One of the most frequent reasons that patients seek dental care is discolored anterior teeth. Although treatment options such as removal of surface stains, bleaching, microabrasion or macroabrasion, veneering, and placement of porcelain crowns are available, conservative approach such as veneer preserves the natural tooth as much as possible. Full veneers are recommended for the restoration of localized defects or areas of intrinsic discoloration, which are caused by deeper internal stains or enamel defects. Indirectly fabricated veneers are much less sensitive compared to a operator′s technique and if multiple teeth are to be veneered, indirect veneers can be usually placed much more expeditiously. Indirect veneers last much longer than the direct veneers. Therefore, indirectly fabricated veneers are more advantageous than directly fabricated veneers in many cases.

  17. Veneer-log production and receipts, North Central Region, 1976.

    Science.gov (United States)

    James E. Blyth; Jerold T. Hahn

    1978-01-01

    Shows 1976 veneer-log production and receipts by species in the Lake States (Michigan, Minnesota, and Wisconsin) and in the Central States (Illinois, Indiana, Iowa, and Missouri). Comparisons are made with similar data for 1974. Includes tables showing veneer-log production and receipts (for selected years) since 1946 in the Lake States and since 1956 in the Central...

  18. Veneer-log production and receipts, North Central Region, 1974.

    Science.gov (United States)

    James E. Blyth; Jerold T. Hahn

    1976-01-01

    Shows 1974 veneer-log production and receipts by species in the Lake States (Michigan, Minnesota, and Wisconsin) and in the Central States (Illinois, Indiana, Iowa, and Missouri). Comparisons are made with similar data for 1972. Includes tables showing veneer-log production and receipts (for selected years) since 1946 in the Lake States and since 1956 in the Central...

  19. Veneer industry and timber use, North Central Region, 1980.

    Science.gov (United States)

    James E. Blyth; W. Brad Smith

    1984-01-01

    Shows 1980 veneer-log production and receipts by species in the Lake State (Michigan, Minnesota, and Wisconsin) and in the Central States (Illinois, Indiana, Iowa, and Missouri). Comparisons are made with similar data collected in 1976. Includes tables showing veneer-log production and receipts (for selected years) since 1946 in the Lake States and since 1956 in the...

  20. Yield and ultrasonic modulus of elasticity of red maple veneer

    Science.gov (United States)

    Robert J. Ross; Steven Verhey; John R. Erickson; John W. Forsman; Brian K. Brashaw; Crystal L. Pilon; Xiping Wang

    2004-01-01

    The purpose of the study was to assess the potential for using red maple sawlogs to manufacture laminated veneer lumber (LVL). The primary objective was to determine the yield of ultrasonically graded veneer from red maple logs. A sample of 48 logs was obtained from six Eastern and Lake States in the United States. The logs were visually graded and shipped to a plywood...

  1. Relationship between stress wave velocities of green and dry veneer

    Science.gov (United States)

    Brian K. Brashaw; Xiping Wang; Robert J. Ross; Roy F. Pellerin

    2004-01-01

    This paper evaluates the relationship between the stress wave velocities of green and dry southern pine and Douglas-fir veneers. A commercial stress wave timer and a laboratory signal analysis system were used to measure the transit time required for an induced stress wave to travel the longitudinal length of each veneer. Stress wave transit times were measured in the...

  2. Contested Categories

    DEFF Research Database (Denmark)

    Drawing on social science perspectives, Contested Categories presents a series of empirical studies that engage with the often shifting and day-to-day realities of life sciences categories. In doing so, it shows how such categories remain contested and dynamic, and that the boundaries they create...

  3. Advances in dental veneers: materials, applications, and techniques.

    Science.gov (United States)

    Pini, Núbia Pavesi; Aguiar, Flávio Henrique Baggio; Lima, Débora Alves Nunes Leite; Lovadino, José Roberto; Terada, Raquel Sano Suga; Pascotto, Renata Corrêa

    2012-01-01

    Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient. Clinicians should understand the latest ceramic materials in order to be able to recommend them and their applications and techniques, and to ensure the success of the clinical case. The current literature was reviewed to search for the most important parameters determining the long-term success, correct application, and clinical limitations of porcelain veneers.

  4. Evaluation of the retentive means, opacifiers and veneering materials for veneered crowns using 137 Cs

    International Nuclear Information System (INIS)

    Nour, A.M.; El-Sadeek; M.E.; Ramadan, F.A.; Eskander, M.

    1991-01-01

    The purpose of this investigation is to evaluate the best plastic veneering material, which affords initial sealing and adaptation to the metal backing. Cs chloride is used for this purpose. The effect of different retentive means, namely, under cuts, wire loops, stainless steel grills, and acrylic beads, as well as the effect of different opaquers were studied. The influence of time factor and changing temperature was considered as well. The results obtained showed the following: 1- A quantitative method for the evaluation of micro leakage is essential parallel to the semiquantitative one. 2- The tested opaquer exhibits a better sealing ability. 3- The leakage increases significantly by temperature cycling, and by time duration with all the veneering materials tested. Composite is the least leak-sensitive material to changes in temperature. 4- Beads offered the best means of retention, to obtain the best sealing qualities.1 tab., 2 fig

  5. Damage Maps of Veneered Zirconia under Simulated Mastication

    Science.gov (United States)

    Kim, Jae-Won; Kim, Joo-Hyung; Janal, Malvin N.; Zhang, Yu

    2016-01-01

    Zirconia based restorations often fracture from chipping and/or delamination of the porcelain veneers. We hypothesize that veneer chipping/delamination is a result of the propagation of near-contact induced partial cone cracks on the occlusal surface under mastication. Masticatory loading involves the opposing tooth sliding along the cuspal inner incline surface with an applied biting force. To test this hypothesis, flat porcelain veneered zirconia plates were cemented to dental composites and cyclically loaded (contact–slide–liftoff) at an inclination angle as a simplified model of zirconia based restorations under occlusion. In the light of in-situ observation of damage evolution in a transparent glass/zirconia/polycarbonate trilayer, postmortem damage evaluation of porcelain/zirconia/composite trilayers using a sectioning technique revealed that deep penetrating occlusal surface partial cone fracture is the predominant fracture mode of porcelain veneers. Clinical relevance is discussed. PMID:19029080

  6. Straight studs from southern pine veneer cores and cordwood

    Science.gov (United States)

    Peter Koch

    1968-01-01

    An economically feasible system has been developed for converting southern pine veneer cores into straight 8-foot studs (2). Prototype studs - two per core - were 100 percent SPIB stud grade and better.

  7. Six-year follow-up with Empress veneers.

    Science.gov (United States)

    Fradeani, M

    1998-06-01

    This study reports on 6 years experience with IPS Empress laminate veneers. A total of 83 anterior veneers were positioned in 21 patients from January 1991 to December 1996 in the author's private practice. Final evaluation was carried out in May and June 1997. Color match, marginal discoloration, recurrent caries, contour, and marginal integrity were evaluated using the modified U.S. Public Health Service criteria at baseline and subsequent recall appointments. On the basis of the criteria used, a large percentage of veneers were rated Alfa. Only one failure was recorded, resulting in a success rate of 98.8%. A thorough description of clinical procedures and laboratory techniques through which anterior teeth can be successfully treated with ceramic veneers is supplied. A clinical case is presented to demonstrate the satisfactory esthetic results obtained using this very conservative restorative technique.

  8. Liver transplantation from maastricht category 2 non-heart-beating donors: a source to increase the donor pool?

    Science.gov (United States)

    Otero, A; Gómez-Gutiérrez, M; Suárez, F; Arnal, F; Fernández-García, A; Aguirrezabalaga, J; García-Buitrón, J; Alvarez, J; Máñez, R

    2004-04-01

    The demand for liver transplantation has increasingly exceeded the supply of cadaver donor organs. Non-heart-beating donors (NHBDs) may be an alternative to increase the cadaver donor pool. The outcome of 20 liver transplants from Maastricht category 2 NHBD was compared with that of 40 liver transplants from heart-beating donors (HBDs). After unsuccessful cardiopulmonary resuscitation (CPR), cardiopulmonary support with simultaneous application of chest and abdominal compression (CPS; n = 6) or cardiopulmonary bypass (CPB; n = 14) was used to maintain the donors. At a minimum follow-up of 2 years, actuarial patient and graft survival rates with livers from Maastricht category 2 NHBD were 80% and 55%, respectively. Transplantation of organs from these donors was associated with a significantly higher incidence of primary nonfunction, biliary complications, and more severe initial liver dysfunction compared with organs from HBDs. The graft survival rates was 83% for livers from NHBDs preserved with CPS and 42% in those maintained with CPB.

  9. Residual stress measurement in veneering ceramic by hole-drilling.

    Science.gov (United States)

    Mainjot, Amélie K; Schajer, Gary S; Vanheusden, Alain J; Sadoun, Michaël J

    2011-05-01

    Mismatch in thermal expansion properties between veneering ceramic and metallic or high-strength ceramic cores can induce residual stresses and initiate cracks when combined with functional stresses. Knowledge of the stress distribution within the veneering ceramic is a key factor for understanding and predicting chipping failures, which are well-known problems with Yttria-tetragonal-zirconia-polycrystal based fixed partial dentures. The objectives of this study are to develop a method for measuring the stress profile in veneering ceramics and to compare ceramic-fused-to-metal compounds to veneered Yttria-tetragonal-zirconia-polycrystal ceramic. The hole-drilling method, often used for engineering measurements, was adapted for use with veneering ceramic. Because of the high sensitivity needed in comparison with industrial applications, a high sensitivity electrical measurement chain was developed. All samples exhibited the same type of stress vs. depth profile, starting with compressive at the ceramic surface, decreasing with depth and becoming tensile at 0.5-1.0mm from the surface, and then becoming slightly compressive again. The zirconia samples exhibited a stress depth profile of larger magnitude. The hole drilling method was shown be a practical tool for measuring residual stresses in veneering ceramics. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. Simplified treatment of severe dental erosion with ultrathin CAD-CAM composite occlusal veneers and anterior bilaminar veneers.

    Science.gov (United States)

    Schlichting, Luís Henrique; Resende, Tayane Holz; Reis, Kátia Rodrigues; Magne, Pascal

    2016-10-01

    Restorative treatment for patients with dental erosion requires an analysis of the degree of structural damage. Patients affected by moderate to severe dental erosion are particularly challenging because complex occlusal reconstruction will be needed. Ultrathin bonded occlusal veneers represent a conservative alternative to traditional onlays and complete coverage crowns for the treatment of severe erosion. This article describes a complete mouth rehabilitation with ultrathin computer-aided design and computer-aided manufacturing (CAD-CAM) composite resin occlusal veneers in a patient with a severely eroded dentition. In the maxillary anterior teeth, the bilaminar approach was chosen with lingual composite resin veneers and labial porcelain veneers. The main benefit of this approach is the possibility of using additive adhesive techniques, allowing only strategic reduction of sound dental structure or no preparation. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  11. Influence of heat treatment and veneering on the storage modulus and surface of zirconia ceramic

    NARCIS (Netherlands)

    Siavikis, G.; Behr, M.; van der Zel, J.M.; Feilzer, A.J.; Rosentritt, M.

    2011-01-01

    Objectives: Glass-ceramic veneered zirconia is used for the application as fixed partial dentures. The aim of this investigation was to evaluate whether the heat treatment during veneering, the application of glass-ceramic for veneering or long term storage has an influence on the storage modulus of

  12. Influence of bruxism on survival of porcelain laminate veneers.

    Science.gov (United States)

    Granell-Ruíz, Maria; Agustín-Panadero, Rubén; Fons-Font, Antonio; Román-Rodríguez, Juan-Luis; Solá-Ruíz, María-Fernanda

    2014-09-01

    This study aims to determine whether bruxism and the use of occlusal splints affect the survival of porcelain laminate veneers in patients treated with this technique. Restorations were made in 70 patients, including 30 patients with some type of parafunctional habit. A total of 323 veneers were placed, 170 in patients with bruxism activity, and the remaining 153 in patients without it. A clinical examination determined the presence or absence of ceramic failure (cracks, fractures and debonding) of the restorations; these incidents were analyzed for association with bruxism and the use of splints. Analysis of the ceramic failures showed that of the 13 fractures and 29 debonding that were present in our study, 8 fractures and 22 debonding were related to the presence of bruxism. Porcelain laminate veneers are a predictable treatment option that provides excellent results, recognizing a higher risk of failure in patients with bruxism activity. The use of occlusal splints reduces the risk of fractures.

  13. Development document for the effluent limitations and guidelines for the ore mining and dressing point source category. Volume I. Final report

    International Nuclear Information System (INIS)

    Jarrett, B.M.; Kirby, R.G.

    1978-07-01

    To establish effluent limitation guidelines and standards of performance, the ore mining and dressing industry was divided into 41 separate categories and subcategories for which separate limitations were recommended. This report deals with the entire metal-ore mining and dressing industry and examines the industry by ten major categories: iron ore; copper ore; lead and zinc ores; gold ore; silver ore; bauxite ore; ferroalloy-metal ores; mercury ores; uranium, radium and vanadium ores; and metal ores, not elsewhere classified ((ores of antimony, beryllium, pltinum, rare earths, tin, titanium, and zirconium). The subcategorization of the ore categories is based primarily upon ore mineralogy and processing or extraction methods employed; however, other factors (such as size, climate or location, and method of mining) are used in some instances. With the best available technology economically achievable, facilities in 21 of the 41 subcategories can be operated with no discharge of process wastewater to navigable waters. No discharge of process wastewater is also achievable as a new source performance standard for facilities in 21 of the 41 subcategories

  14. Masking properties of ceramics for veneer restorations.

    Science.gov (United States)

    Skyllouriotis, Andreas L; Yamamoto, Hideo L; Nathanson, Dan

    2017-10-01

    The translucency and opacity of ceramics play a significant role in emulating the natural color of teeth, but studies of the masking properties and limitations of dental ceramics when used as monolayer restorations are lacking. The purpose of this in vitro study was to determine the translucency of 6 materials used for veneer restorations by assessing their translucency parameters (TPs), contrast ratios (CRs), and potential to mask dark tooth colors. Ten square- or disk-shaped specimens (0.5-mm thickness, shade A2) were fabricated from Vitablocks Mark II (VMII; Vita Zahnfabrik), IPS e.max CAD LT (EMXC LT; Ivoclar Vivadent AG), IPS e.max CAD HT (EMXC HT; Ivoclar Vivadent AG), IPS Empress CAD LT (EMP LT; Ivoclar Vivadent AG), IPS e.max Press LT (EMXP LT; Ivoclar Vivadent AG), and CZR (CZR; Kuraray Noritake Dental Inc). Their luminance (Y) values over black and over white tiles were measured, followed by their color (CIELab) over black tiles and white tiles and shaded A2 (control group), A3.5, A4, and B4 acrylic resin blocks. All measurements were performed using a spectrophotometer in 2 different areas on each specimen. Then CRs, TPs, and color differences (over shaded backgrounds) were determined. Data were subjected to 1-way and 2-way ANOVA (α=.05) for analysis. Mean CR values of EMXP LT were significantly higher than those of the other tested materials, whereas VMII and EMXC HT had the lowest values (Pmasking properties against the A4 background. The color differences of most tested ceramics were more acceptable when tested against the B4 background (ΔE*≤3.3). Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  15. Organizational Categories as Viewing Categories

    OpenAIRE

    Mik-Meyer, Nanna

    2005-01-01

    This paper explores how two Danish rehabilitation organizations textual guidelines for assessment of clients’ personality traits influence the actual evaluation of clients. The analysis will show how staff members produce institutional identities corresponding to organizational categories, which very often have little or no relevance for the clients evaluated. The goal of the article is to demonstrate how the institutional complex that frames the work of the organizations produces the client ...

  16. Attribution of aerosol radiative forcing over India during the winter monsoon to emissions from source categories and geographical regions

    Science.gov (United States)

    Verma, S.; Venkataraman, C.; Boucher, O.

    2011-08-01

    We examine the aerosol radiative effects due to aerosols emitted from different emission sectors (anthropogenic and natural) and originating from different geographical regions within and outside India during the northeast (NE) Indian winter monsoon (January-March). These studies are carried out through aerosol transport simulations in the general circulation (GCM) model of the Laboratoire de Météorologie Dynamique (LMD). The model estimates of aerosol single scattering albedo (SSA) show lower values (0.86-0.92) over the region north to 10°N comprising of the Indian subcontinent, Bay of Bengal, and parts of the Arabian Sea compared to the region south to 10°N where the estimated SSA values lie in the range 0.94-0.98. The model estimated SSA is consistent with the SSA values inferred through measurements on various platforms. Aerosols of anthropogenic origin reduce the incoming solar radiation at the surface by a factor of 10-20 times the reduction due to natural aerosols. At the top-of-atmosphere (TOA), aerosols from biofuel use cause positive forcing compared to the negative forcing from fossil fuel and natural sources in correspondence with the distribution of SSA which is estimated to be the lowest (0.7-0.78) from biofuel combustion emissions. Aerosols originating from India and Africa-west Asia lead to the reduction in surface radiation (-3 to -8 W m -2) by 40-60% of the total reduction in surface radiation due to all aerosols over the Indian subcontinent and adjoining ocean. Aerosols originating from India and Africa-west Asia also lead to positive radiative effects at TOA over the Arabian Sea, central India (CNI), with the highest positive radiative effects over the Bay of Bengal and cause either negative or positive effects over the Indo-Gangetic plain (IGP).

  17. Fracture strengths of chair‑side‑generated veneers cemented with ...

    African Journals Online (AJOL)

    2014-06-09

    Jun 9, 2014 ... Group 1), CAD/CAM‑fabricated veneers cemented with a glass fiber ... specimens were tested with a universal testing machine after thermal cycling treatment. ... The purpose of the current in vitro study is to determine the ..... fracture resistance of fiber reinforced cups‑replacing composite restorations.

  18. The changing veneer and plywood industry of Michigan and Wisconsin.

    Science.gov (United States)

    Gary R. Lindell; Lewis T. Hendricks

    1972-01-01

    Analyzes trends in the hardwood veneer and plywood industry of Michigan and Wisconsin between 1964 and 1969. In that period, red oak and hard maple replaced yellow birch as the major species used. Log supplies were adequate. Wall paneling was the major end market with doorskins next. Excess plywood producing capacity is a chronic problem.

  19. Wettability and Impact Performance of Wood Veneer/Polyester Composites

    Directory of Open Access Journals (Sweden)

    Shayesteh Haghdan

    2015-07-01

    Full Text Available Fiber-reinforced thermosetting composites have been of interest since the 1940s due to their ease of use in processing, fast curing times, and high specific stiffness and strength. While the use of plant fibers in a polyester matrix has been thoroughly studied, only limited information is available regarding using wood as reinforcement. In this study, composites of thin wood veneer and a polyester matrix were made and the difficulties in the lamination and curing processes were investigated. Sheets of Douglas fir, maple, and oak veneers using a catalyzed polyester resin were assembled as unidirectional, balanced, and unbalanced cross-ply laminates. These were compared to control specimens using glass fiber as reinforcement. The impact properties of the samples, with respect to the laminate thicknesses, were characterized using a drop-weight impact tester. The wettability and surface roughness of unsanded and sanded wood veneers were also investigated. Results showed that Douglas fir cross-ply laminates had an impact energy equivalent to glass fiber laminates, making them an interesting alternative to synthetic fiber composites. Wood/polyester laminates absorbed a considerable amount of energy through a higher number of fracture modes. The balanced lay-up limited twisting of the wood/polyester composites. The lowest contact angle and highest wettability were observed in unsanded Douglas fir veneers.

  20. Fracture strengths of chair‑side‑generated veneers cemented with ...

    African Journals Online (AJOL)

    Introduction: CAD/CAM (computer‑aided design and computer‑aided manufacturing) systems have refreshed the idea of chair‑side production of restorations, but the fracture of ceramic veneers remains a problem. Cementation with glass fibers may improve the fracture strengths and affect the failure modes of ...

  1. Effect of Silviculture on the Yield and Quality of Veneers

    Science.gov (United States)

    Leslie H. Groom; Ray Newbold; Jim Guldin

    2002-01-01

    The structural and aesthetic value of wood is typically sacrificed in an attempt to meet demand. This paper addresses the financial and quality aspects of silvicultural choices as it relates to wood veneers. Five trees each were harvested from an uneven-aged stand and from the following even- aged stands: intensive plantation, conventional plantation, and natural...

  2. In situ polymerization of polyaniline in wood veneers.

    Science.gov (United States)

    Trey, Stacy; Jafarzadeh, Shadi; Johansson, Mats

    2012-03-01

    The present study describes the possibility to polymerize aniline within wood veneers to obtain a semi-conducting material with solid wood acting as the base template. It was determined that it is possible to synthesize the intrinsically conductive polymer (ICP) polyaniline in situ within the wood structure of Southern yellow pine veneers, combining the strength of the natural wood structure with the conductivity of the impregnated polymer. It was found that polyaniline is uniformly dispersed within the wood structure by light microscopy and FT-IR imaging. A weight percent gain in the range of 3-12 wt % was obtained with a preferential formation in the wood structure and cell wall, rather than in the lumen. The modified wood was found to be less hydrophilic with the addition of phosphate doped polyaniline as observed by equilibrium water swelling studies. While wood itself is insulating, the modified veneers had conductivities of 1 × 10(-4) to 1 × 10(-9) S cm(-1), demonstrating the ability to tune the conductivity and allowing for materials with a wide range of applications, from anti-static to charge-dispersing materials. Furthermore, the modified veneers had lower total and peak heat releases, as determined by cone calorimetry, because of the char properties of the ICP. This is of interest if these materials are to be used in building and furniture applications where flame retardance is of importance. © 2012 American Chemical Society

  3. Porcelain veneer post-bonding crack repair by resin infiltration

    NARCIS (Netherlands)

    Gresnigt, Marco; Magne, Michel; Magne, Pascal

    2017-01-01

    Ceramic laminate veneer restorations are indicated in several clinical situations. Indirect restorations are usually chosen if the less-invasive options - bleaching, resin infiltration, or composite resin restorations - are not possible, or when it is too difficult to achieve an esthetically

  4. Evaluation of a novel multiple phase veneering ceramic.

    Science.gov (United States)

    Sinthuprasirt, Pannapa; van Noort, Richard; Moorehead, Robert; Pollington, Sarah

    2015-04-01

    To produce a new veneering ceramic based on the production of a multiple phase glass-ceramic with improved performance in terms of strength and toughness. A composition of 60% leucite, 20% diopside and 20% feldspathic glass was prepared, blended and a heat treatment schedule of 930°C for 5 min was derived from differential thermal analysis (DTA) of the glasses. X-ray diffraction (XRD) and SEM analysis determined the crystalline phases and microstructure. Chemical solubility, biaxial flexural strength (BFS), fracture toughness, hardness, total transmittance and coefficient of thermal expansion (CTE) were all measured in comparison to a commercial veneering ceramic (VITA VM9). Thermal shock resistance of the leucite-diopside and VITA VM9 veneered onto a commercial high strength zirconia (Vita In-Ceram YZ) was also assessed. Statistical analysis was undertaken using Independent Samples t-test. Weibull analysis was employed to examine the reliability of the strength data. The mean chemical solubility was 6 μg/cm(2) for both ceramics (P=1.00). The mean BFS was 109 ± 8 MPa for leucite-diopside ceramic and 79 ± 11 MPa for VITA VM9 ceramic (P=0.01). Similarly, the leucite-diopside ceramic demonstrated a significantly higher fracture toughness and hardness. The average total transmittance was 46.3% for leucite-diopside ceramic and 39.8% for VITA VM9 (P=0.01). The leucite-diopside outperformed the VITA VM9 in terms of thermal shock resistance. Significance This novel veneering ceramic exhibits significant improvements in terms of mechanical properties, yet retains a high translucency and is the most appropriate choice as a veneering ceramic for a zirconia base core material. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Consumer Product Category Database

    Science.gov (United States)

    The Chemical and Product Categories database (CPCat) catalogs the use of over 40,000 chemicals and their presence in different consumer products. The chemical use information is compiled from multiple sources while product information is gathered from publicly available Material Safety Data Sheets (MSDS). EPA researchers are evaluating the possibility of expanding the database with additional product and use information.

  6. Structural and Chemical Analysis of the Zirconia-Veneering Ceramic Interface.

    Science.gov (United States)

    Inokoshi, M; Yoshihara, K; Nagaoka, N; Nakanishi, M; De Munck, J; Minakuchi, S; Vanmeensel, K; Zhang, F; Yoshida, Y; Vleugels, J; Naert, I; Van Meerbeek, B

    2016-01-01

    The interfacial interaction of veneering ceramic with zirconia is still not fully understood. This study aimed to characterize morphologically and chemically the zirconia-veneering ceramic interface. Three zirconia-veneering conditions were investigated: 1) zirconia-veneering ceramic fired on sandblasted zirconia, 2) zirconia-veneering ceramic on as-sintered zirconia, and 3) alumina-veneering ceramic (lower coefficient of thermal expansion [CTE]) on as-sintered zirconia. Polished cross-sectioned ceramic-veneered zirconia specimens were examined using field emission gun scanning electron microscopy (Feg-SEM). In addition, argon-ion thinned zirconia-veneering ceramic interface cross sections were examined using scanning transmission electron microscopy (STEM)-energy dispersive X-ray spectrometry (EDS) at high resolution. Finally, the zirconia-veneering ceramic interface was quantitatively analyzed for tetragonal-to-monoclinic phase transformation and residual stress using micro-Raman spectroscopy (µRaman). Feg-SEM revealed tight interfaces for all 3 veneering conditions. High-resolution transmission electron microscopy (HRTEM) disclosed an approximately 1.0-µm transformed zone at sandblasted zirconia, in which distinct zirconia grains were no longer observable. Straight grain boundaries and angular grain corners were detected up to the interface of zirconia- and alumina-veneering ceramic with as-sintered zirconia. EDS mapping disclosed within the zirconia-veneering ceramic a few nanometers thick calcium/aluminum-rich layer, touching the as-sintered zirconia base, with an equally thick silicon-rich/aluminum-poor layer on top. µRaman revealed t-ZrO2-to-m-ZrO2 phase transformation and residual compressive stress at the sandblasted zirconia surface. The difference in CTE between zirconia- and the alumina-veneering ceramic resulted in residual tensile stress within the zirconia immediately adjacent to its interface with the veneering ceramic. The rather minor chemical

  7. Identification and characterization of five non-traditional-source categories: Catastrophic/accidental releases, vehicle repair facilities, recycling, pesticide application, and agricultural operations. Final report, September 1991-September 1992

    International Nuclear Information System (INIS)

    Sleva, S.; Pendola, J.A.; McCutcheon, J.; Jones, K.; Kersteter, S.L.

    1993-03-01

    The work is part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plans (SIP) area source methodologies and to develop appropriate emissions estimation methodologies and emission factors for a group of these source categories. Based on the results of the identification and characterization portions of the research, five source categories were selected for methodology and emission factor development: catastrophic/accidental releases, vehicle repair facilities, recycling, pesticide application and agricultural operations. The report presents emissions estimation methodologies and emission factor data for the selected source categories. The discussions for each selected category include general background information, emissions generation activities, pollutants emitted, sources of activity and pollutant data, emissions estimation methodologies, issues to be considered and recommendations. The information used in these discussions was derived from various sources including available literature, industrial and trade association publications and contracts, experts on the category and activity, and knowledgeable federal and state personnel

  8. Evidence of yttrium silicate inclusions in YSZ-porcelain veneers.

    Science.gov (United States)

    Stoner, Brian R; Griggs, Jason A; Neidigh, John; Piascik, Jeffrey R

    2014-04-01

    This report introduces the discovery of crystalline defects that can form in the porcelain veneering layer when in contact with yttria-stabilized zirconia (YSZ). The focus was on dental prostheses and understanding the defects that form in the YSZ/porcelain system; however the data reported herein may have broader implications toward the use and stability of YSZ-based ceramics in general. Specimens were cut from fully sintered YSZ plates and veneering porcelain was applied (X-ray (EDAX) was used for microstructural and elemental analysis. EDAX, for chemical analysis and transmission electron diffraction (TED) for structural analysis were both performed in the transmission electron microscope (TEM). Additionally, in order to spatially resolve Y-rich precipitates, micro-CT scans were conducted at varying depths within the porcelain veneer. Local EDAX (SEM) was performed in the regions of visible inclusions and showed significant increases in yttrium concentration. TEM specimens also showed apparent inclusions in the porcelain and selected area electron diffraction was performed on these regions and found the inclusions to be crystalline and identified as either yttrium-silicate (Y2 SiO5 ) or yttrium-disilicate (Y2 Si2 O7 ). Micro-CT data showed that yttrium-silicate precipitates were distributed throughout the thickness of the porcelain veneer. Future studies are needed to determine whether many of the premature failures associated with this materials system may be the result of crystalline flaws that form as a result of high temperature yttrium diffusion near the surfaces of YSZ. © 2013 Wiley Periodicals, Inc.

  9. Opalescence of all-ceramic core and veneer materials.

    Science.gov (United States)

    Cho, Moon-Sang; Yu, Bin; Lee, Yong-Keun

    2009-06-01

    The enamel of natural teeth is opalescent, where there is light scattering of the shorter wavelengths of the visible spectrum, giving a tooth a bluish appearance in the reflected color and an orange/brown appearance in the transmitted color. The objective of this study was to determine the opalescence of all-ceramic core, veneer and layered specimens with a color measuring spectrophotometer. Colors of core (A2-corresponding shade), veneer (A2- and A3-corresponding shades) and layered (A2- and A3-layered) ceramics for all-ceramic restorations in clinically relevant thicknesses were measured in the reflectance and transmittance modes. The opalescence parameter (OP), which was calculated as the difference in blue-yellow coordinate (Deltab(*)) and red-green coordinate (Deltaa(*)), and the differences in blue-yellow coordinate (Deltab(*)) and in color (DeltaE(ab)(*)) between the reflected and transmitted colors were calculated. One-way ANOVA was performed for the OP values of the core, veneer and layered specimens by the kind of materials. Regression analysis was performed between the OP and Deltab(*), and the OP and DeltaE(ab)(*) values. The range of the OP value was 1.6-6.1, 2.0-7.1, 1.3-5.0 and 1.6-4.2 for the core, veneer, A2- and A3-layered specimens, respectively, all of which were significantly influenced by the kind of materials (pOpalescence varied by kind of ceramics. The OP values of ceramics were lower than those of tooth enamel. All-ceramic materials that can simulate the opalescence of natural teeth should be developed.

  10. Fracture strengths of chair-side-generated veneers cemented with glass fibers.

    Science.gov (United States)

    Turkaslan, S; Bagis, B; Akan, E; Mutluay, M M; Vallittu, P K

    2015-01-01

    CAD/CAM (computer-aided design and computer-aided manufacturing) systems have refreshed the idea of chair-side production of restorations, but the fracture of ceramic veneers remains a problem. Cementation with glass fibers may improve the fracture strengths and affect the failure modes of CAD/CAM-generated ceramic veneers. Therefore, this study compared the fracture strengths of ceramic veneers produced at chair side and cemented with or without glass fibers with those of composite veneers. Thirty intact mandibular incisors were randomly divided into three groups ( n = 10) and treated with CAD/CAM-fabricated veneers cemented with dual-cure composite resin luting cement (CRLC; Group 1), CAD/CAM-fabricated veneers cemented with a glass fiber network (GFN) and dual-cure CRLC (Group 2), and a direct particulate filler composite veneer constructed utilizing fiber and a restorative composite resin (Group 3). The specimens were tested with a universal testing machine after thermal cycling treatment. The loads at the start of fracture were the lowest for traditionally fabricated composite veneers and higher for CAD/CAM-generated. Veneers cemented either without or with the GFN. The failure initiation loads (N) for the veneers were 798.92 for Group 1, 836.27 for Group 2, and 585.93 for Group 3. The predominant failure mode is adhesive failure between the laminates and teeth for Group 1, cohesive failure in the luting layer for Group 2, and cohesive laminate failure for Group 3, which showed chipping and small fractures. Ceramic material is a reliable alternative for veneer construction at chair side. Fibers at the cementation interface may improve the clinical longevity and provide higher fracture strength values.

  11. Masking ability of bi- and tri- laminate all-ceramic veneers on tooth-colored ceramic discs.

    Science.gov (United States)

    Farhan, Daniel; Sukumar, Smitha; von Stein-Lausnitz, Axel; Aarabi, Ghazal; Alawneh, Ahmad; Reissmann, Daniel R

    2014-01-01

    A predictable esthetic outcome is imperative when placing ceramic veneers. Discolored teeth pose a major challenge as sufficient material thickness is required to achieve a good esthetic result. There is limited evidence in the literature that compares the masking ability of multi-laminate veneers. The aim of this in-vitro study was to compare the masking ability of bi-laminate (BL) and tri-laminate (TL) all-ceramic veneers cemented on tooth-colored ceramic discs. A total of 40 veneers (shade A1, 10-mm diameter, 0.8-mm thick) were manufactured-20 BL veneers (0.4-mm pressable ceramic coping veneered with 0.4-mm thick enamel layer) and 20 TL veneers (0.4-mm coping veneered with 0.2-mm thick opaque interlayer and 0.2-mm thick enamel layer). A bonding apparatus was utilized to adhesively cement all veneers on the ceramic discs (shade A1), simulating teeth of light and dark color. The resulting groups (N = 10 each) were the reference groups (shade A1 ceramic base) BL-1 and TL-1 veneers, and the test groups (shade A4 ceramic base) BL-4 and TL-4 veneers. The color of the cemented veneers was measured using a spectrophotometer. The data were converted to CIE L*a*b* coordinates, and ΔE* were calculated to allow for statistical analysis. The color differences between the samples with the A1 and A4 ceramic bases were significantly lower when covered with TL veneers (mean ΔE*: 3.2 units) than with BL veneers (mean ΔE*: 4.0 units: p bi-laminate veneers. Patients with discolored/darker teeth may benefit from a more predictable esthetic result when teeth restored with tri-laminate rather than bi-laminate veneers. © 2014 Wiley Periodicals, Inc.

  12. Influence of framework color and layering technique on the final color of zirconia veneered restorations

    NARCIS (Netherlands)

    Aboushelib, M.N.; Dozic, A.; Liem, J.K.

    2010-01-01

    Objective: To investigate the influence of colored zirconia frameworks on the overall color match of zirconia- veneered restorations. Method and Materials: Identical natural and colored zirconia frameworks (Cercon Base, Degudent) were layered using a veneer ceramic (IPS e.max Ceram Dentin, Ivoclar

  13. Physical, mechanical, and fire properties of oriented strandboard with fire retardant treated veneers

    Science.gov (United States)

    Nadir Ayrilmis; Zeki Candan; Robert White

    2007-01-01

    This study evaluated physical, mechanical and fire properties of oriented strand boards (OSB) covered with fire retardant treated veneers. The beech (Fagus orientalis Lipsky) veneers were treated with either monoammonium phosphate, diammonium phosphate, lime water or a borax/boric acid (1 : 1 by weight) mixture. Physical and mechanical properties of the specimens were...

  14. Cone calorimeter testing of foam core sandwich panels treated with intumescent paper underneath the veneer (FRV)

    Science.gov (United States)

    Mark A. Dietenberger; Ali Shalbafan; Johannes Welling

    2017-01-01

    Surfaces of novel foam core sandwich panels were adhered with intumescent fire‐retardant paper underneath the veneers (FRV) to improve their flammability properties. The panels were evaluated by means of cone calorimeter test (ASTM E 1354). Variables tested were different surface layer treatments, adhesives used for veneering, surface layer thicknesses, and processing...

  15. Ultrathin CAD-CAM Ceramic Occlusal Veneers and Anterior Bilaminar Veneers for the Treatment of Moderate Dental Biocorrosion: A 1.5-Year Follow-Up.

    Science.gov (United States)

    Resende, T H; Reis, K R; Schlichting, L H; Magne, P

    2018-03-27

    Dental biocorrosion can produce a devastating impact on oral health. The restorative phase of the treatment should not cause additional damage of the remaining sound tooth structure. Ultrathin occlusal veneers are a conservative alternative to traditional onlays and complete crowns for the treatment of severe biocorrosive lesions. This strategy is explained in the present case report through a full-mouth rehabilitation of a patient with moderate biocorrosion. Maxillary anterior teeth were restored using the bilaminar technique (lingual direct composite veneers with labial ceramic veneers) and posterior teeth using ultrathin CAD-CAM ceramic occlusal veneers. The technical aspects required for the implementation of this new restorative design are presented with a special emphasis on the control of tooth preparation based on diagnostic wax-up, provisionalization, and the use of CAD-CAM technology.

  16. Numerical simulation of hot-pressed veneer products: Forming - Spring back – Distortion

    DEFF Research Database (Denmark)

    Ormarsson, Sigurdur; Sandberg, Dick

    2007-01-01

    Customers demand very high quality of veneered furniture products with regard to surface appearance, shape stability and stiffness. To meet these requirements, it is important to improve the manufacturing process by a better understanding of the thermo-hygro-mechanical behaviour of the individual...... veneers. During the manufacture of strongly curved products, the veneers are exposed to large membrane and bending deformations and to high pressure in the radial fibre direction. When hot-press forming is used, the veneers are also exposed to a high surface temperature during the pressing time (curing...... time). These severe conditions can result in plastic deformation perpendicular to the veneer surface as well as mechano-sorptive strains in the curved regions, since the heating can have a significant influence on the moisture distribution. How strong an influence these factors have on the distortion...

  17. Origin and mixing timescale of Earth's late veneer

    Science.gov (United States)

    Prescher, C.; Allu Peddinti, D.; Bell, E. A.; Bello, L.; Cernok, A.; Ghosh, N.; Tucker, J.; Wielicki, M. M.; Zahnle, K. J.

    2012-12-01

    Experimental studies on the partitioning behavior of highly siderophile elements (HSE) between silicate and metallic melts imply that the Earth's mantle should have been highly depleted in these elements by core formation in an early magma ocean. However, present HSE contents of the Earth's mantle are ~3 orders of magnitude higher than that expected by experiments. The apparent over-abundance of HSE has commonly been explained by the addition of meteoritic material in the "late veneer" which describes the exogenous mass addition following the moon forming impact and concluding with the late heavy bombardment at ~3.8-3.9 Ga. The strongest evidence for this theory is that the platinum group element (PGE) contents in today's mantle are present in chondritic relative abundances, as opposed to a fractionated pattern expected with metal-silicate partitioning. Archean komatiites indicate that the PGE content of the Earth's mantle increased from about half their present abundances at 3.5 Ga to their present abundances at 2.9 Ga. This secular increase in PGE content suggests a progressive mixing of the late veneer material into the Earth's mantle. However, this time scale also implies that the whole mantle was relatively well mixed by 2.9 Ga. We use a compilation of existing isotopic and trace element data in order to constrain the origin and composition of the late veneer. We use PGE abundances, W abundances and W isotopic compositions in chondritic meteorites and the primitive upper mantle to compute the amount of mass delivered during the late veneer and find the late veneer mass to be ~0.6 % the mass of the bulk silicate Earth (consistent with earlier estimates). We also use the 187Re-187Os and 190Pt-186Os systems to constrain the composition and timing of delivery of the impacting population. We model the efficiency of mantle mixing in this time frame by using 3-dimensional numerical geodynamical simulations and geochemical constraints. Initial parameters include the

  18. Indirect veneer treatment of anterior maxillary teeth with enamel hypoplasia

    Directory of Open Access Journals (Sweden)

    Devi Eka Juniarti

    2010-09-01

    Full Text Available Background: Nowadays, aesthetic rehabilitation becomes a necessity. It is affected by patient’s background, especially career, social and economic status. The aesthetic abnormality of anterior teeth i.e discoloration, malposition and malformation can affect patient’s appearance, especially during smile. These dental abnormalities, as a result, can decrease patient’s performance. Dental malformation, for instance, can be caused by developmental tooth defect, such as enamel hypoplasia. Enamel hypoplasia is a developmental defect caused by the lack of matrix amount which leads to thin and porous enamel. Enamel hypoplasia can also be caused by matrix calcification disturbance starting from the formation and development of enamel matrix causing defect and permanent changes which can occur on one or more tooth. Purpose: The aim of the study is to improve dental discoloration and tooth surface texture on anterior maxillary teeth with enamel hypoplasia by using indirect veneer with porcelain material. Case: A 20 years-old woman with enamel hypoplasia came to the Dental Hospital, Faculty of Dentistry Airlangga University. The patient wanted to improve her anterior maxillary teeth. It is clinically known that there were some opaque white spots (chalky spotted and porous on anterior teeth’s surface. Case management: Indirect veneer with porcelain material had been chosen as a restoration treatment which has excellent aesthetics and strength, and did not cause gingival irritation. As a result, the treatment could improve the confidence of the patient, and could also make their function normal. Conclusion: Indirect veneer is an effective treatment, which can improve patient’s appearance and self confidence.Latar belakang: Saat ini perbaikan estetik menjadi suatu kebutuhan. Kebutuhan akan estetik dipengaruhi latar belakang penderita, terutama karir, status sosial dan ekonomi. Hal ini disebabkan, kelainan estetik seperti diskolorasi, malposisi

  19. Fracture mechanics analyses of ceramic/veneer interface under mixed-mode loading.

    Science.gov (United States)

    Wang, Gaoqi; Zhang, Song; Bian, Cuirong; Kong, Hui

    2014-11-01

    Few studies have focused on the interface fracture performance of zirconia/veneer bilayered structure, which plays an important role in dental all-ceramic restorations. The purpose of this study was to evaluate the fracture mechanics performance of zirconia/veneer interface in a wide range of mode-mixities (at phase angles ranging from 0° to 90°), and to examine the effect of mechanical properties of the materials and the interface on the fracture initiation and crack path of an interfacial crack. A modified sandwich test configuration with an oblique interfacial crack was proposed and calibrated to choose the appropriate geometry dimensions by means of finite element analysis. The specimens with different interface inclination angles were tested to failure under three-point bending configuration. Interface fracture parameters were obtained with finite element analyses. Based on the interfacial fracture mechanics, three fracture criteria for crack kinking were used to predict crack initiation and propagation. In addition, the effects of residual stresses due to coefficient of thermal expansion mismatch between zirconia and veneer on the crack behavior were evaluated. The crack initiation and propagation were well predicted by the three fracture criteria. For specimens at phase angle of 0, the cracks propagated in the interface; whereas for all the other specimens the cracks kinked into the veneer. Compressive residual stresses in the veneer can improve the toughness of the interface structure. The results suggest that, in zirconia/veneer bilayered structure the veneer is weaker than the interface, which can be used to explain the clinical phenomenon that veneer chipping rate is larger than interface delamination rate. Consequently, a veneer material with larger fracture toughness is needed to decrease the failure rate of all-ceramic restorations. And the coefficient of thermal expansion mismatch of the substrates can be larger to produce larger compressive

  20. 3D-characterization of the veneer-zirconia interface using FIB nano-tomography.

    Science.gov (United States)

    Mainjot, Amélie K; Douillard, Thierry; Gremillard, Laurent; Sadoun, Michaël J; Chevalier, Jérôme

    2013-02-01

    The phenomena occurring during zirconia frameworks veneering process are not yet fully understood. In particular the study of zirconia behavior at the interface with the veneer remains a challenge. However this interface has been reported to act on residual stress in the veneering ceramic, which plays a significant role in clinical failures such as chipping. The objective of this study was thus to investigate the veneer-zirconia interface using a recent 3D-analysis tool and to confront these observations to residual stress measurements in the veneering ceramic. Two cross-sectioned bilayered disc samples (veneer on zirconia), exhibiting different residual stress profiles in the veneering ceramic, were investigated using 2D and 3D imaging (respectively Scanning Electron Microscopy (SEM) and Focused Ion Beam nanotomography (FIB-nt), associated with chemical analysis by Energy Dispersive X-ray Spectroscopy (EDS). The observations did not reveal any structural change in the bulk of zirconia layer of both samples. However the presence of structural alterations and sub-surface microcracks were highlighted in the first micrometer of zirconia surface, exclusively for the sample exhibiting interior tensile stress in the veneering ceramic. No interdiffusion phenomena were observed. FIB nanotomography was proven to be a powerful technique to study the veneer-zirconia interface. The determination of the origin and the nature of zirconia alterations need to be further studied. The results of the present study support the hypothesis that zirconia surface property changes could be involved in the development of tensile stress in the veneering ceramic, increasing the risk of chipping. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  1. [A preliminary study on the color effect of IPS Empress all-ceramic veneers].

    Science.gov (United States)

    Li, Zhi-yong; Cheng, Xiang-rong; Wang, Yi-ning

    2004-09-01

    To evaluate the opaquing capacity, color compatibility and stability of IPS Empress all-ceramic veneers. A total of 86 IPS Empress all-ceramic veneers were made for 18 patients. The patients were divided into three groups: Group A was tetracycline teeth, 64 veneers for 5 patients; Group B was non-tetracycline teeth, 22 veneers for 13 patients; Group C was 22 natural vital teeth with normal color as control group. Before and after veneers were inserted, ShadeEye NCC was employed to obtain L * a * b * values of each tooth. The values of cemented veneers used as the baseline, the L * a * b * values of each veneer were measured half a year, 1 year, and 2 years after restoration respectively. All L * a * b * values at different evaluation times were analyzed by SPSS 10.0. Before and after veneers were restored, the L * a * b * values of both Group A and Group B were significantly different, the color difference being 5.01 and 4.15 respectively. The color difference between Group A and selected shade guides was 2.45. Compared with the baseline value, the L * value of Group A significantly decreased 2 years after restoration, but the DeltaE of different evaluation times was not significantly different. The color difference between Group B and Group C was 0.22 and there was no significant color difference after restoration. IPS Empress all-ceramic veneers have excellent opaquing capacity, color compatibility and stability to non-tetracycline teeth. To tetracycline teeth IPS Empress all-ceramic veneers have a certain opaquing capacity, but they cannot completely match with shade guides; the L * value is significantly different after restoration and further studies are needed to evaluate its color effect.

  2. [An in vitro study of the fracture strength of tooth preparations for Empress 2 veneers and crowns and mandibular incisors restored with Empress 2 veneers and crowns].

    Science.gov (United States)

    Wei, Xue; Li, Yan

    2009-12-01

    To compare the fracture resistance of mandibular incisors' preparations for veneers and crowns, mandibular incisors restored with Empress 2 veneers and crowns. 50 human mandibular incisors were randomly divided into five groups. Each group consisted of ten teeth and the treatment obtained as follows: A, tooth preparations for veneers; B, tooth preparations for crowns; C, teeth restored with veneers; D, teeth restored with crowns; E, untreated group. The teeth received standardized preparation and the restorations were manufactured with Empress 2 system and cemented with resin luting agent. The fracture resistances of teeth were measured by Instron universal testing machine and statistically analyzed with one-way ANOVA. The fracture resistances of A, B, C, D, E were (576.11 +/- 91.53), (204.13 +/- 85.88), (451.50 +/- 116.81), (386.16 +/- 117.75) and (566.05 +/- 121.37) N, respectively. The statistical analysis demonstrated significant differences between five groups. There were no significant differences between group A and E, group C and D. Tooth preparations for veneers did not significantly reduce the fracture resistance of mandibular incisor. The fracture resistance of teeth restored with Empress 2 veneers and crowns did not significantly differ from each other.

  3. Spherical powder for retaining thermosetting acrylic resin veneers.

    Science.gov (United States)

    Tanaka, T; Atsuta, M; Uchiyama, Y; Nakabayashi, N; Masuhara, E

    1978-03-01

    1. Nine different sizes of spherical powder were prepared, and their effectiveness as retentive devices was evaluated against those available commercially. 2. Smaller-diameter spherical powder (No. 5) gave the best results of all retaining devices tested. 3. The physical properties of the resins play an important role in the retentive strength with No. 5 retention beads. The retentive strength was reduced when brittle resin was used. 4. The retentive strength of the resin veneer was greatly affected by the angle of stress at the incisal resin. The retentive strength increased as the angle between the longitudinal axis of the specimen and the direction of stress decreased.

  4. Late Veneer consequences on Venus' long term evolution

    Science.gov (United States)

    Gillmann, C.; Golabek, G.; Tackley, P. J.; Raymond, S. N.

    2017-12-01

    Modelling of Venus' evolution is able to produce scenarios consistent with present-day observation. These results are however heavily dependent on atmosphere escape and initial volatile inventory. This primordial history (the first 500 Myr) is heavily influenced by collisions. We investigate how Late Veneer impacts change the initial state of Venus and their consequences on its coupled mantle/atmosphere evolution. We focus on volatile fluxes: atmospheric escape and mantle degassing. Mantle dynamics is simulated using the StagYY code. Atmosphere escape covers both thermal and non-thermal processes. Surface conditions are calculated with a radiative-convective model. Feedback of the atmosphere on the mantle through surface temperature is included. Large impacts are capable of contributing to atmospheric escape, volatile replenishment and energy transfer. We use the SOVA hydrocode to take into account volatile loss and deposition during a collision. Large impacts are not numerous enough to substantially erode Venus' atmosphere. Single impacts don't have enough eroding power. Swarms of small bodies (history of the planet and leads to lower present-day surface temperatures. Total depletion of the mantle seems unlikely, meaning either few large impacts (1 to 4) or low energy (slow, grazing…) collisions. Combined with the lack of plate tectonics and volatile recycling in the interior of Venus, Late Veneer collisions could help explain why Venus seems dry today.

  5. Fabrication of Hydrophobic Surface on Wood Veneer via Electroless Nickel Plating Combined with Chemical Corrosion

    Directory of Open Access Journals (Sweden)

    Zhaojun Tang

    2015-12-01

    Full Text Available Birch veneers were coated with Ni-P films by a combined process of KBH4 activation and electroless plating. The plated veneers were further chemically corroded to obtain hydrophobic surfaces on wood. The effect of chemical corrosion on the contact angle of the veneers was investigated. The hydrophobic veneers were characterized by X-ray photo electron spectroscopy (XPS, scanning electron microscopy (SEM, and X-ray diffraction (XRD. The surface contact angle of birch veneer before and after it was plated with Ni-P alloy coating was 41º and 121º, respectively. The contact angle reached 136.7º when the nickel-coated veneers were corroded in CuSO4 aqueous solution for 30 min. XPS analysis showed that Cu0 cluster doped with little CuO formed on the corroded surface of Ni-P alloy film after chemical corrosion. SEM and XRD showed that rough copper clusters formed on the surface of the wood veneer and revealed the reason of the surface hydrophobicity. This study provides a new pathway for fabricating hydrophobic wood.

  6. Cyclic testing of porcelain laminiate veneers on superficial enamel and dentin: Pressed vs. conventional layered porcelain

    Science.gov (United States)

    Tawde, Shweta

    Statement of Problem: Clinicians are inclined towards more aggressive teeth preparations to accommodate the thickness of the veneering material. The principle of conservative tooth preparation is compromised. Purpose: By using a conservative approach to treatment with porcelain veneers, long-lasting, esthetic and functional results may be achieved. Sacrificing as little tooth structure as possible and conserving the supporting tissues will facilitate prospective patients. Materials and Methods: Forty extracted human maxillary and mandibular canines were selected. The teeth were divided into one of two groups (pressable and stackable) and further subdivided according to tooth substrate (all-enamel or mixed enamel-dentin exposure). Twenty canine teeth were allotted to the pressable veneer group and 20 were allotted to the stackable veneer group. Of the 20 teeth in the pressable group, all were pressed with a lithium disilicate ceramic system (IPS e.max Press), 10 with labial tooth reduction of 0.3-0.5 mm maintaining superficial enamel (PEN) and the remaining 10 teeth with labial veneer reduction of 0.8-1.0 mm exposing superficial dentin (PDN). Of the 20 teeth in the stackable group, all were stacked/ layered with conventional feldspathic porcelain (Fortune; Williams/ Ivoclar); with labial veneer reduction of 0.3-0.5 mm maintaining superficial enamel (SEN) and the remaining 10 teeth with labial veneer reduction of 0.8-1.0 mm exposing superficial dentin (SDN). Silicon putty matrix was fabricated prior to teeth preparation to estimate the teeth reduction. The prepared facial reduction was limited to the incisal edge. No incisal or palatal/lingual reduction was performed. Impressions of the prepared teeth were taken in medium/light-bodied PVS. Master casts were made in Resin Rock. The stackable group specimens were made with fabricating refractory dies and after following the recommended steps of laboratory procedure, stackable veneers were processed. The pressable group

  7. [Preliminary study of bonding strength between diatomite-based dental ceramic and veneering porcelains].

    Science.gov (United States)

    Lu, Xiao-li; Gao, Mei-qin; Cheng, Yu-ye; Zhang, Fei-min

    2015-04-01

    In order to choose the best veneering porcelain for diatomite-based dental ceramic substrate, the bonding strength between diatomite-based dental ceramics and veneering porcelains was measured, and the microstructure and elements distribution of interface were analyzed. The coefficient of thermal expansion (CTE) of diatomite-based dental ceramics was detected by dilatometry. Three veneering porcelain materials were selected with the best CTE matching including alumina veneering porcelain (group A), titanium porcelain veneering porcelain (group B), and E-max veneering porcelain (group C). Shear bonding strength was detected. SEM and EDS were used to observe the interface microstructure and element distribution. Statistical analysis was performed using SPSS 17.0 software package. The CTE of diatomite-based dental ceramics at 25-500 degrees centigrade was 8.85×10-6K-1. The diatomite-based substrate ceramics combined best with group C. Shear bonding strength between group A and C and group B and C both showed significant differences(P<0.05). SEM and EDS showed that the interface of group C sintered tightly and elements permeated on both sides of the interface. The diatomite-based substrate ceramics combines better with E-max porcelain veneer.

  8. Sources

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1991-01-01

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  9. Example Annual Certification & Compliance Reports for Sources with and without Visible Emissions Testing: NESHAP Area Source Standards for Nine Metal Fabrication and Finishing Source Categories 40 CFR 63 Subpart XXXXXX

    Science.gov (United States)

    This page contains examples of the type of information that must be submitted to fulfill the Notification of Compliance Status requirement of 40 CFR 63, subpart XXXXXX for sources reporting and not reporting visible emissions information.

  10. Fracture and Fatigue Resistance of Cemented versus Fused CAD-on Veneers over Customized Zirconia Implant Abutments.

    Science.gov (United States)

    Nossair, Shereen Ahmed; Aboushelib, Moustafa N; Morsi, Tarek Salah

    2015-01-05

    To evaluate the fracture mechanics of cemented versus fused CAD-on veneers on customized zirconia implant abutments. Forty-five identical customized CAD/CAM zirconia implant abutments (0.5 mm thick) were prepared and seated on short titanium implant abutments (Ti base). A second scan was made to fabricate 45 CAD-on veneers (IPS Empress CAD, A2). Fifteen CAD-on veneers were cemented on the zirconia abutments (Panavia F2.0). Another 15 were fused to the zirconia abutments using low-fusing glass, while manually layered veneers served as control (n = 15). The restorations were subjected to artificial aging (3.2 million cycles between 5 and 10 kg in a water bath at 37°C) before being axially loaded to failure. Fractured specimens were examined using scanning electron microscopy to detect fracture origin, location, and size of critical crack. Stress at failure was calculated using fractography principles (alpha = 0.05). Cemented CAD-on restorations demonstrated significantly higher (F = 72, p CAD-on and manually layered restorations. Fractographic analysis of fractured specimens indicated that cemented CAD-on veneers failed due to radial cracks originating from the veneer/resin interface. Branching of the critical crack was observed in the bulk of the veneer. Fused CAD-on veneers demonstrated cohesive fracture originating at the thickest part of the veneer ceramic, while manually layered veneers failed due to interfacial fracture at the zirconia/veneer interface. Within the limitations of this study, cemented CAD-on veneers on customized zirconia implant abutments demonstrated higher fracture than fused and manually layered veneers. © 2014 by the American College of Prosthodontists.

  11. Porcelain veneer post-bonding crack repair by resin infiltration.

    Science.gov (United States)

    Gresnigt, Marco; Magne, Michel; Magne, Pascal

    Ceramic laminate veneer restorations are indicated in several clinical situations. Indirect restorations are usually chosen if the less-invasive options - bleaching, resin infiltration, or composite resin restorations - are not possible, or when it is too difficult to achieve an esthetically pleasing result in the long term. Bonded indirect partial restorations are highly dependent on their adhesive interface, as these thin restorations have a relatively low cohesive strength. Therefore, preservation of sound enamel, conditioning of the restorations and of the substrate, and luting procedures are of paramount importance for a successful outcome. Even when utmost care is taken during every step of the procedure, failures such as fractures, chipping, or marginal discoloration and defects sometimes occur. Only very few of these cases of failure are presented or are a subject of interest. In this case presentation, a fracture repair is performed using an infiltration technique with a resin composite material.

  12. Surface roughness of composite resin veneer after application of herbal and non-herbal toothpaste

    Science.gov (United States)

    Nuraini, S.; Herda, E.; Irawan, B.

    2017-08-01

    The aim of this study was to find out the surface roughness of composite resin veneer after brushing. In this study, 24 specimens of composite resin veneer are divided into three subgroups: brushed without toothpaste, brushed with non-herbal toothpaste, and brushed with herbal toothpaste. Brushing was performed for one set of 5,000 strokes and continued for a second set of 5,000 strokes. Roughness of composite resin veneer was determined using a Surface Roughness Tester. The results were statistically analyzed using Kruskal-Wallis nonparametric test and Post Hoc Mann-Whitney. The results indicate that the highest difference among the Ra values occurred within the subgroup that was brushed with the herbal toothpaste. In conclusion, the herbal toothpaste produced a rougher surface on composite resin veneer compared to non-herbal toothpaste.

  13. Study on Flexural Creep Parameters of Overlayed Particleboard by Natural and Melaminated Veneers

    Directory of Open Access Journals (Sweden)

    Abdollah Najafi

    2012-06-01

    Full Text Available In this study, effects of natural and artificial veneer on flexural creep behavior of particleboard was investigated. Particleboard panels were prepared from Pars Neopan industries with 660 kg/m3 density and then overlaid by natural and melamine veneers. Their creep behavior was compared to control particleboard. For evaluating maximum bending load in static flexural test, specimens were cut from panels according to ASTM D 1037 with dimensions of 370×50×16 mm. Then, The flexural creep tests at 20% and 40% of failure bending load was applied to test specimens. Results of flexural tests indicated that the MOR and MOE values of veneered particleboard were highest. Results of creep showed that levels of stresses are effective on all creep parameters, but showed less effect on relative creep. Also, creep parameters less effective on specimens overlaid by natural veneer.

  14. Color management of porcelain veneers: influence of dentin and resin cement colors.

    Science.gov (United States)

    Dozic, Alma; Tsagkari, Maria; Khashayar, Ghazal; Aboushelib, Moustafa

    2010-01-01

    Porcelain veneers have become an interesting treatment option to correct the shape and color of anterior teeth. Because of their limited thickness and high translucency, achieving a good color match is influenced by several variables. The aim of this work was to investigate the influence of natural dentin and resin cement colors on final color match of porcelain veneers. A preselected shade tab (A1) was chosen as the target color for a maxillary central incisor, and its color parameters (L*a*b*) were measured using a digital spectrophotometer (SpectroShade, MHT). Nine natural dentin colors (Natural Die Material, Ivoclar Vivadent) representing a wide range of tooth colors were used to prepare resin replicas of the maxillary central incisor with a standard preparation for porcelain veneers. The prepared porcelain veneers (IPS Empress Esthetic, A1, 0.6 mm thick, Ivoclar Vivadent) were cemented on the resin dies (nine groups of natural dentin colors) using seven shades of resin cement (Variolink Veneers, Ivoclar Vivadent). The L*a*b* values of the cemented veneers were measured, and DE values were calculated against the preselected target color (A1). DE greater than 3.3 was considered as a significant color mismatch detectable by the human eye. The seven shades of resin cement had no significant influence on the final color of the veneers, as the measured DE values were almost identical for every test group. On the other hand, the color of natural dentin was a significant factor that influenced final color match. None of the 63 tested combinations (nine natural dentin colors and seven resin cement colors) produced an acceptable color match. Thin porcelain veneers cannot mask underlying tooth color even when different shades of resin cement are used. Incorporation of opaque porcelain (high chroma) may improve final color match.

  15. Durability of feldspathic veneering ceramic on glass-infiltrated alumina ceramics after long-term thermocycling.

    Science.gov (United States)

    Mesquita, A M M; Ozcan, M; Souza, R O A; Kojima, A N; Nishioka, R S; Kimpara, E T; Bottino, M A

    2010-01-01

    This study compared the bond strength durability of a feldspathic veneering ceramic to glass-infiltrated reinforced ceramics in dry and aged conditions. Disc shaped (thickness: 4 mm, diameter: 4 mm) of glass-infiltrated alumina (In-Ceram Alumina) and glass-infiltrated alumina reinforced by zirconia (In-Ceram Zirconia) core ceramic specimens (N=48, N=12 per groups) were constructed according to the manufacturers' recommendations. Veneering ceramic (VITA VM7) was fired onto the core ceramics using a mold. The core-veneering ceramic assemblies were randomly divided into two conditions and tested either immediately after specimen preparation (Dry) or following 30000 thermocycling (5-55 ºC±1; dwell time: 30 seconds). Shear bond strength test was performed in a universal testing machine (cross-head speed: 1 mm/min). Failure modes were analyzed using optical microscope (x20). The bond strength data (MPa) were analyzed using ANOVA (α=0.05). Thermocycling did not decrease the bond strength results for both In-Ceram Alumina (30.6±8.2 MPa; P=0.2053) and In-Ceram zirconia (32.6±9 MPa; P=0.3987) core ceramic-feldspathic veneering ceramic combinations when compared to non-aged conditions (28.1±6.4 MPa, 29.7±7.3 MPa, respectively). There were also no significant differences between adhesion of the veneering ceramic to either In-Ceram Alumina or In-Ceram Zirconia ceramics (P=0.3289). Failure types were predominantly a mixture of adhesive failure between the veneering and the core ceramic together with cohesive fracture of the veneering ceramic. Long-term thermocycling aging conditions did not impair the adhesion of the veneering ceramic to the glass-infiltrated alumina core ceramics tested.

  16. Stiffness and Density Analysis of Rotary Veneer Recovered from Six Species of Australian Plantation Hardwoods

    Directory of Open Access Journals (Sweden)

    Robert Lee McGavin

    2015-08-01

    Full Text Available Commercial interest in Australian hardwood plantations is increasing. The timber industry is investigating alternative supplies of forest resources, and the plantation growing industry is eager to explore alternative markets to maximize financial returns. Identifying suitable processing strategies and high-value products that suit young, plantation-grown hardwoods have proven challenging; however, recent veneer processing trials using simple veneer technology have demonstrated more acceptable recoveries of marketable products. The recovered veneers have visual qualities that are suitable for structurally-based products; however, the mechanical properties of the veneer are largely unknown. Veneers resulting from processing trials of six commercially important Australian hardwood species were used to determine key wood properties (i.e., density, dynamic modulus of elasticity (MoE, and specific MoE. The study revealed that a wide variation of properties existed between species and also within species. Simple mathematical modeling, using sigmoidal curves, was demonstrated to be an effective method to model the evolution of key wood properties across the billet radius and along the resulting veneer ribbon with benefits for tree breeders and processors.

  17. The Effect of Core and Veneering Design on the Optical Properties of Polyether Ether Ketone.

    Science.gov (United States)

    Zeighami, S; Mirmohammadrezaei, S; Safi, M; Falahchai, S M

    2017-12-01

    This study aimed to evaluate the effect of core shade and core and veneering thickness on color parameters and translucency of polyether ether ketone (PEEK). Sixty PEEK discs (0.5 and 1 mm in thickness) with white and dentine shades were veneered with A2 shade indirect composite resin with 0.5, 1 and 1.5 mm thickness (n=5). Cores without the veneering material served as controls for translucency evaluation. Color parameters were measured by a spectroradiometer. Color difference (ΔE₀₀) and translucency parameters (TP) were computed. Data were analyzed using one-way ANOVA and Tukey's test (for veneering thickness) and independent t-test (for core shade and thickness) via SPSS 20.0 (p⟨0.05). Regarding the veneering thickness, white cores of 0.5 mm thickness showed significant differences in all color parameters. In white cores of 1 mm thickness and dentine cores of 0.5 and 1 mm thickness, there were statistically significant differences only in L∗, a∗ and h∗. The mean TP was significantly higher in all white cores of 1 mm thickness than dentine cores of 1 mm. Considering ΔE₀₀=3.7 as clinically unacceptable, only three groups had higher mean ΔE₀₀ values. Core shade, core thickness, and the veneering thickness affected the color and translucency of PEEK restorations. Copyright© 2017 Dennis Barber Ltd.

  18. Effect of various intermediate ceramic layers on the interfacial stability of zirconia core and veneering ceramics.

    Science.gov (United States)

    Yoon, Hyung-In; Yeo, In-Sung; Yi, Yang-Jin; Kim, Sung-Hun; Lee, Jai-Bong; Han, Jung-Suk

    2015-01-01

    The purposes of this study were to evaluate the effects of intermediate ceramics on the adhesion between the zirconia core and veneer ceramics. The polished surfaces of fully sintered Y-TZP blocks received three different treatments: (1) connector (C), (2) liner (L) or (3) wash layer (W). All the treated zirconia blocks were veneered with either (a) fluorapatite glass-ceramic (E) or (b) feldspathic porcelain (V) and divided into four groups (CE, CV, LE and WV). For the control group, the testing surfaces of metal blocks were veneered with feldspathic porcelain (VM). A half of the samples in each group (n = 21) were exposed to thermocycling, while the other half of the specimens were stored at room temperature under dry conditions. All specimens were subjected to the shear test and the failed surfaces were microscopically examined. The elemental distribution at the zirconia core/veneer interface was analyzed. The specimens in Groups CE and CV exhibited significantly greater mean bond strength values than those in Groups LE and WV, respectively (p ceramic substances into the zirconia surface. A glass-ceramic based connector is significantly more favorable to core/veneer adhesion than the other intermediate ceramics evaluated in the study. However, thermal cycling affected the bond strength at the core/veneer interface differently according to the intermediate ceramics.

  19. IDENTIFICATION AND CHARACTERIZATION OF FIVE NON- TRADITIONAL SOURCE CATEGORIES: CATASTROPHIC/ACCIDENTAL RELEASES, VEHICLE REPAIR FACILITIES, RECYCLING, PESTICIDE APPLICATION, AND AGRICULTURAL OPERATIONS

    Science.gov (United States)

    The report gives results of work that is part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plan (SIP) area source methodologies and to deve...

  20. Categories from scratch

    NARCIS (Netherlands)

    Poss, R.

    2014-01-01

    The concept of category from mathematics happens to be useful to computer programmers in many ways. Unfortunately, all "good" explanations of categories so far have been designed by mathematicians, or at least theoreticians with a strong background in mathematics, and this makes categories

  1. Testing the Late-Veneer hypothesis with selenium isotopes

    Science.gov (United States)

    Labidi, J.; Koenig, S.; Bennett, N.; Kurzawa, T.; Aierken, E.; Shahar, A.; Schoenberg, R.

    2016-12-01

    Selenium (Se) is a siderophile element displaying an excess abundance in Earth's mantle compared to experimental predictions [1], which may be attributed to the Late-Veneer. As Se is also volatile, testing the late-veneer addition of Se can constrain the origin of other volatile elements on Earth. Here we combine high-precision Se isotope measurements of metal-silicate partitioning experiments and chondrites to assess whether planetary differentiation could leave a measurable Se isotopic signature on planetary mantles. We performed Se isotopic measurements of 5 metal-silicate partitioning experiments and 20 chondrites of all major classes. Experiments were conducted at 1 GPa and 1650 C for 1 to 4 hours using the piston-cylinder apparatus at Carnegie's Geophysical Laboratory. After wet chemistry, data were obtained on a ThermoFisher Scientific™ NeptunePlus MC-ICP-MS at the University of Tübingen with a 74Se/77Se double spike technique. δ82/76Se values are given relative to NIST SRM-3149 and the external reproducibility calculated from duplicate meteorite analyses is ≤ 0.1‰ (2 s.d.). Chondrites vary over a 0.8‰ range of δ82/76Se values. CIs and CMs show evidence for heavier 82Se/76Se ratios, likely due to mixing processes in the proto-planetary nebula. When these isotopically heavier meteorites are excluded, remaining chondrites have δ82/76Se values varying over a 0.3‰ range, within uncertainty of previous results [2]. We suggest that these chondrites may be used to estimate a δ82/76Se value of bulk planets. At the conditions of our experiments, the partition coefficients for Se log Dmetal-silicate range from 0.7±0.1 to 1.9±0.1, consistent with previous work [1]. A small but resolvable Se isotopic fractionation was observed: 82Se/76Se ratios were enriched by ≤ 0.5‰ in the silicates relative to the metals. Thus, given current uncertainties for Se isotopic measurements, marginal differences between planetary mantles and chondrites may be resolved

  2. [Study on color of thermosetting resin for veneer crown].

    Science.gov (United States)

    Kamitomai, H

    1989-02-01

    Based on the viewpoint that stresses the importance of achieving natural colors and forms for veneer crown, four representative kinds of thermosetting resins were investigated colorimetrically in an attempt to clarify the relationship between the thickness and color of resins in opaque, dentin and enamel colors respectively. A spectrophotometer was used to measure the colors, the CIE colorimetric system employed to show the readings, and the CIE 1964 U*V*W* space was utilized to indicate the color differences, with the following results. 1. In the case of dentin, certain specific colors were observed for thickness of 1.3 to 1.8 mm when used alone, but when applied over opaque the range was 0.2 to 0.5 mm lower than when used alone. 2. Enamel resins were grouped into two types according to different color groups, one group similar to achromatic color with low limpidity and the other similar to the dentin color with high limpidity. The former type became more grayer with an increase in thickness when applied over dentin. The latter type showed no difference in color even when the thickness increased. This study has shown that the facing color results vary depending on the color properties of the different resins used. Therefore, it is advisable that careful consideration be given to these differencies in order to achieve the intended color facing.

  3. Effect of Sandblasting on Shear Bond Strength Composite Resin Veneer

    Directory of Open Access Journals (Sweden)

    Octarina Octarina

    2013-07-01

    Full Text Available Attachment between restoration and enamel surface in indirect resin composite veneer restoration (IRCV is obtained using multi-step (MS resin cement. Recently, a one step self-adhesive dual-cured resin cement (SADRC was introduced. Objective: To determine the effect of sandblasting on shear bond strength (SBS of IRCV to enamel using MS resin cement and SADRC. Methods: Forty specimens of buccal surface of enamel human were light-cured in Solidilite chamber and were divided into two groups: IRCV without sandblasting (n=20 and with sandblasting for 10 seconds (n=20 and then bonded to enamel using MS (n=10 and SADRC (n=10, respectively. After 24h SBS of specimens were tested using a Universal Testing Machine. Data were analyzed statistically by one-way ANOVA. Results: The average SBS value of IRCV without SB and bonded with MS was 18.95+7.80MPa and MS with SB was 19.30+ SB (4.85+2.12MPa and SADRC with SB (9.57+3.45MPa(p<0.05. Conclusion: increased SBS VIRK to enamel using MS resin cement than SADRC.  

  4. Cervical and incisal marginal discrepancy in ceramic laminate veneering materials: A SEM analysis

    Directory of Open Access Journals (Sweden)

    Hemalatha Ranganathan

    2017-01-01

    Full Text Available Context: Marginal discrepancy influenced by the choice of processing material used for the ceramic laminate veneers needs to be explored further for better clinical application. Aims: This study aimed to evaluate the amount of cervical and incisal marginal discrepancy associated with different ceramic laminate veneering materials. Settings and Design: This was an experimental, single-blinded, in vitro trial. Subjects and Methods: Ten central incisors were prepared for laminate veneers with 2 mm uniform reduction and heavy chamfer finish line. Ceramic laminate veneers fabricated over the prepared teeth using four different processing materials were categorized into four groups as Group I - aluminous porcelain veneers, Group II - lithium disilicate ceramic veneers, Group III - lithium disilicate-leucite-based veneers, Group IV - zirconia-based ceramic veneers. The cervical and incisal marginal discrepancy was measured using a scanning electron microscope. Statistical Analysis Used: ANOVA and post hoc Tukey honest significant difference (HSD tests were used for statistical analysis. Results: The cervical and incisal marginal discrepancy for four groups was Group I - 114.6 ± 4.3 μm, 132.5 ± 6.5 μm, Group II - 86.1 ± 6.3 μm, 105.4 ± 5.3 μm, Group III - 71.4 ± 4.4 μm, 91.3 ± 4.7 μm, and Group IV - 123.1 ± 4.1 μm, 142.0 ± 5.4 μm. ANOVA and post hoc Tukey HSD tests observed a statistically significant difference between the four test specimens with regard to cervical marginal discrepancy. The cervical and incisal marginal discrepancy scored F = 243.408, P < 0.001 and F = 180.844, P < 0.001, respectively. Conclusion: This study concluded veneers fabricated using leucite reinforced lithium disilicate exhibited the least marginal discrepancy followed by lithium disilicate ceramic, aluminous porcelain, and zirconia-based ceramics. The marginal discrepancy was more in the incisal region than in the cervical region in all the groups.

  5. Blocking in Category Learning

    OpenAIRE

    Bott, Lewis; Hoffman, Aaron B.; Murphy, Gregory L.

    2007-01-01

    Many theories of category learning assume that learning is driven by a need to minimize classification error. When there is no classification error, therefore, learning of individual features should be negligible. We tested this hypothesis by conducting three category learning experiments adapted from an associative learning blocking paradigm. Contrary to an error-driven account of learning, participants learned a wide range of information when they learned about categories, and blocking effe...

  6. Category I structures program

    International Nuclear Information System (INIS)

    Endebrock, E.G.; Dove, R.C.

    1981-01-01

    The objective of the Category I Structure Program is to supply experimental and analytical information needed to assess the structural capacity of Category I structures (excluding the reactor cntainment building). Because the shear wall is a principal element of a Category I structure, and because relatively little experimental information is available on the shear walls, it was selected as the test element for the experimental program. The large load capacities of shear walls in Category I structures dictates that the experimental tests be conducted on small size shear wall structures that incorporates the general construction details and characteristics of as-built shear walls

  7. Three-Point Bending Tests of Zirconia Core/Veneer Ceramics for Dental Restorations

    Directory of Open Access Journals (Sweden)

    Massimo Marrelli

    2013-01-01

    Full Text Available Introduction. The mechanical strength and the surface hardness of commercially available yttrium-doped zirconia were investigated. Furthermore, a comparative study of eight different ceramic veneers, to be used for the production of two-layered all-ceramic restorative systems, was carried out. Materials and Methods. Four types of zirconia specimens were analyzed, according to a standard ISO procedure (ISO 6872. Besides, two-layered zirconia-veneer specimens were prepared for three-point bending tests. Results. A strong effect of the surface roughness on the mechanical strength of zirconia specimens was observed. Finally, a comparative study of eight commercially available veneering ceramics shows different modes of failure between the selected veneers. Conclusion. The results indicate that close attention should be paid to the preparation of zirconia-based crowns and bridges by CAD/CAM process, because surface roughness has an important effect on the mechanical strength of the material. Finally, the results of the mechanical tests on two-layered specimens represent an important support to the choice of the veneering ceramic.

  8. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    International Nuclear Information System (INIS)

    Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T; Padipatvuthikul, P

    2011-01-01

    Silicon nitride (Si 3 N 4 ) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si 3 N 4 ceramic as a dental core material. The white Si 3 N 4 was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si 3 N 4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si 3 N 4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder ( 2 O 3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si 3 N 4 specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10 -6 deg. C -1 , rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  9. Evaluation of veneer yields and grades from yellow-poplar, white oak, and sweetgum from the southeast

    Science.gov (United States)

    Robert H. McAlister

    1980-01-01

    Dry volume yields and standard grades of veneer are given for yellow-poplar, sweetgum, and white oak by tree diameter and location within the stem. Results show that the typical stands of mixed southern pine and hardwood timer yield enough veneer to utilize almost 90 percent of the stand volume in the production of COM-PLY lumber and panels

  10. Randomized controlled split-mouth clinical trial of direct laminate veneers with two micro-hybrid resin composites

    NARCIS (Netherlands)

    Gresnigt, Marco M. M.; Kalk, Warner; Ozcan, M.; Ozcan, Mutlu

    Objectives: This randomized, split-mouth clinical study evaluated the survival rate of direct laminate veneers made of two resin-composite materials. Methods: A total of 23 patients (mean age: 52.4 years old) received 96 direct composite laminate veneers using two micro-hybrid composites in

  11. Categories and logical syntax

    NARCIS (Netherlands)

    Klev, Ansten Morch

    2014-01-01

    The notions of category and type are here studied through the lens of logical syntax: Aristotle's as well as Kant's categories through the traditional form of proposition `S is P', and modern doctrines of type through the Fregean form of proposition `F(a)', function applied to argument. Topics

  12. Computing color categories

    NARCIS (Netherlands)

    Yendrikhovskij, S.N.; Rogowitz, B.E.; Pappas, T.N.

    2000-01-01

    This paper is an attempt to develop a coherent framework for understanding, modeling, and computing color categories. The main assumption is that the structure of color category systems originates from the statistical structure of the perceived color environment. This environment can be modeled as

  13. Interfacial Adhesion and Damping Characteristics of Laminated Veneer Lumber Intercalated with Rubber Sheets

    Directory of Open Access Journals (Sweden)

    Jingquan Han

    2016-06-01

    Full Text Available Laminated wood veneer lumber intercalated with rubber sheets (LLVR was fabricated using a layered adhesive system composed of polyaryl polymethylene isocyanate (PAPI for wood-rubber inter-bonding and phenol formaldehyde (PF resin to glue the wood veneers. The optimized manufacturing process (chloroprene rubber: CR; PAPI: 80 g/m2; PF: 200 g/m2; and silane: 9.0 wt.% was determined. The process as developed was then utilized to fabricate nine-ply LLVRs of five balanced constructions with two or three CR laminates used as various layers. The physico-mechanical properties of the LLVRs were evaluated, and the results showed that LLVRs had strong shear strength, sound dimensional stability, decent bending strength, and favorable toughening and buffering performances. The newly developed product is an interesting potential alternative to traditional laminated veneer lumber or plywood.

  14. Digital workflow for virtually designing and milling ceramic lithium disilicate veneers: a clinical report.

    Science.gov (United States)

    Zandinejad, A; Lin, W S; Atarodi, M; Abdel-Azim, T; Metz, M J; Morton, D

    2015-01-01

    Laminate veneers have been routinely used to restore and enhance the appearance of natural dentition. The traditional pathway for fabricating veneers consisted of making conventional polyvinyl siloxane impressions, producing stone casts, and fabricating final porcelain prostheses on stone dies. Pressed ceramics have successfully been used for laminate veneer fabrication for several years. Recently, digital computer-aided design/computer-aided manufacturing scanning has become commercially available to make a digital impression that is sent electronically to a dental laboratory or a chairside milling machine. However, technology has been developed to allow digital data acquisition in conjunction with electronically transmitted data that enables virtual design of restorations and milling at a remote production center. Following the aforementioned workflow will provide the opportunity to fabricate a physical cast-free restoration. This new technique has been reported recently for all-ceramic IPS e.max full-coverage pressed-ceramic restorations. However, laminate veneers are very delicate and technique-sensitive restorations when compared with all-ceramic full-coverage ones made from the same material. Complete digital design and fabrication of multiple consecutive laminate veneers seems to be very challenging. This clinical report presents the digital workflow for the virtual design and fabrication of multiple laminate veneers in a patient for enhancing the esthetics of his maxillary anterior teeth. A step-by-step process is presented with a discussion of the advantages and disadvantages of this novel technique. Additionally, the use of lithium disilicate ceramic as the material of choice and the rationale for such a decision is discussed.

  15. Influence of cooling rate on residual stress profile in veneering ceramic: measurement by hole-drilling.

    Science.gov (United States)

    Mainjot, Amélie K; Schajer, Gary S; Vanheusden, Alain J; Sadoun, Michaël J

    2011-09-01

    The manufacture of dental crowns and bridges generates residual stresses within the veneering ceramic and framework during the cooling process. Residual stress is an important factor that control the mechanical behavior of restorations. Knowing the stress distribution within the veneering ceramic as a function of depth can help the understanding of failures, particularly chipping, a well-known problem with Yttria-tetragonal-zirconia-polycrystal based fixed partial dentures. The objective of this study is to investigate the cooling rate dependence of the stress profile in veneering ceramic layered on metal and zirconia frameworks. The hole-drilling method, often used for engineering measurements, was adapted for use with veneering ceramic. The stress profile was measured in bilayered disc samples 20 mm in diameter, with a 0.7 mm thick metal or Yttria-tetragonal-zirconia-polycrystal framework and a 1.5mm thick veneering ceramic. Three different cooling procedures were investigated. The magnitude of the stresses in the surface of the veneering ceramic was found to increase with cooling rate, while the interior stresses decreased. At the surface, compressive stresses were observed in all samples. In the interior, compressive stresses were observed in metal samples and tensile in zirconia samples. Cooling rate influences the magnitude of residual stresses. These can significantly influence the mechanical behavior of metal-and zirconia-based bilayered systems. The framework material influenced the nature of the interior stresses, with zirconia samples showing a less favorable stress profile than metal. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  16. Influence of firing time and framework thickness on veneered Y-TZP discs curvature.

    Science.gov (United States)

    Jakubowicz-Kohen, Boris D; Sadoun, Michaël J; Douillard, Thierry; Mainjot, Amélie K

    2014-02-01

    The objective of the present work was to study the curvature of very thinly, veneered Y-TZP discs of different framework thicknesses submitted to different firing times. Fifteen 20-mm-wide Y-TZP discs were produced in three different thicknesses: 0.75, 1, 1.5mm. One disc from each group was left unveneered while the others were layered with a 0.1mm veneering ceramic layer. All discs underwent five firing cycles for a total cumulative firing time of 30 min, 1, 2, 5 and 10h at 900°C. The curvature profile was measured using a profilometer after the veneering process and after each firing cycle respectively. A fitted curve was then used to estimate the, curvature radius. The coefficient of thermal expansion (CTE) measurements were taken on veneering, ceramic and Y-TZP beam samples that underwent the same firing schedule. Those data were used to calculate the curvature generated by CTE variations over firing time. All bilayered samples exhibited a curvature that increased over firing time inversely to framework thickness. However non-veneered samples did not exhibit any curvature modification. The results of the present study reveal that even a very thin veneer layer (0.1mm) can induce a significant curvature of Y-TZP discs. The dilatometric results showed that Tg and CTE, variations are not sufficient to explain this curvature. A chemical-induced zirconia volume, augmentation located at the framework sub-surface near the interface could explain the sample, curvature and its increase with firing time. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  17. [Effect of ceramic thickness and resin cement shades on final color of heat-pressed ceramic veneers].

    Science.gov (United States)

    Ren, D F; Zhan, K R; Chen, X D; Xing, W Z

    2017-02-09

    Objective: To analyze the effect of ceramic materials thickness and resin cement shades on the final color of ceramic veneers in the discolored teeth, and to investigate the color agreement of try-in pastes to the corresponding resin cements. Methods: Sixty artificial maxillary central incisor teeth (C2 shade) were used to simulate the natural discolored teeth and prepared according to veneer tooth preparation protocol. Veneers of different thickness in the body region (0.50 and 0.75 mm) were fabricated using ceramic materials (LT A2 shade, IPS e.max Press). The ceramic veneer specimens were bonded to the artificial teeth using the 6 shades of resin cements (Variolink Veneer: shades of LV-3, LV-2, HV+3; RelyX™ Veneer: shades of TR, A3, WO) ( n= 5). A clinical spectrophotometer was used to measure the color parameters of ceramic veneers at the cervical, body and incisal regions. Color changes of veneers before and after cementation were calculated and registered as ΔE1, and the changes between try-in paste and the corresponding resin cements were registered as ΔE2. Results: Three-way ANOVA indicated that ΔE1 and ΔE2 values were significantly affected by the ceramic thickness, resin cement shades and measuring regions ( Pceramic veneers were cemented with resin cements in shades of HV+3 and WO. The ΔE2 values of six shades ranged from 0.60-2.56. The shades of HV+3, WO and A3 resin cements were more than 1.60. Conclusions: Different thickness of ceramic materials, resin cement shades and measuring regions could affect the final color of ceramic veneers. The color differences of some resin cements and corresponding try-in pastes might be observed in clinical practice.

  18. A Step-by-Step Conservative Approach for CAD-CAM Laminate Veneers

    Directory of Open Access Journals (Sweden)

    Gerardo Durán Ojeda

    2017-01-01

    Full Text Available The use of CAD/CAM technology has allowed the fabrication of ceramic restorations efficiently and with predictable results. Lithium disilicate is a type of glass ceramic material that can be used for the elaboration of laminate veneers, being monolithic restorations which require characterization through a covering ceramic in order to achieve acceptable esthetic results. The next case report shows a predictable clinical protocol for the rehabilitation of the anterior teeth through the preparation of CAD/CAM veneers (e.max CAD, Ivoclar Vivadent, Liechtenstein which have been characterized by a nanofluorapatite ceramic (e.max Ceram, Ivoclar Vivadent, Liechtenstein through the layering technique.

  19. Relative translucency of six all-ceramic systems. Part II: core and veneer materials.

    Science.gov (United States)

    Heffernan, Michael J; Aquilino, Steven A; Diaz-Arnold, Ana M; Haselton, Debra R; Stanford, Clark M; Vargas, Marcos A

    2002-07-01

    STATEMENT OF PROBLEM All-ceramic core materials with various strengthening compositions have a range of translucencies. It is unknown whether translucency differs when all-ceramic materials are fabricated similarly to the clinical restoration with a veneered core material. This study compared the translucency of 6 all-ceramic materials veneered and glazed at clinically appropriate thicknesses. Core specimens (n = 5 per group) of Empress dentin, Empress 2 dentin, In-Ceram Alumina, In-Ceram Spinell, In-Ceram Zirconia, and Procera AllCeram were fabricated as described in Part I of this study and veneered with their corresponding dentin porcelain to a final thickness of 1.47 +/- 0.01 mm. These specimens were compared with veneered Vitadur Alpha opaque dentin (as a standard), a clear glass disc (positive control), and a high-noble metal-ceramic alloy (Porc. 52 SF) veneered with Vitadur Omega dentin (negative control). Specimen reflectance was measured with an integrating sphere attached to a spectrophotometer across the visible spectrum (380 to 700 nm); 0-degree illumination and diffuse viewing geometry were used. Measurements were repeated after a glazing cycle. Contrast ratios were calculated from the luminous reflectance (Y) of the specimens with a black (Yb) and a white backing (Yw) to give Yb/Yw with CIE illuminant D65 and a 2-degree observer function (0.0 = transparent, 1.0 = opaque). One-way analysis of variance and Tukey's multiple-comparison test were used to analyze the data (P<.05). Significant differences in contrast ratios were found among the ceramic systems tested when they were veneered (P<.0001) and after the glazing cycle (P<.0001). Significant changes in contrast ratios (P<.0001) also were identified when the veneered specimens were glazed. Within the limitations of this study, a range of translucency was identified in the veneered all-ceramic systems tested. Such variability may affect their ability to match natural teeth. The glazing cycle resulted

  20. Kubelka-Munk reflectance theory applied to porcelain veneer systems using a colorimeter.

    Science.gov (United States)

    Davis, B K; Johnston, W M; Saba, R F

    1994-01-01

    The purpose of this study was to demonstrate the ability of Kubelka-Munk reflectance theory to predict color parameters of veneer porcelain on various backings using colorimetric measurements. Tristimulus absorption and scattering coefficients were used to predict the respective tristimulus reflectance values of A1, D3, and translucent porcelain samples after they had been bonded to light and dark substrates using universal, opaque, and untinted shades of bonding resin. Observed and predicted reflectance values exhibited high correlation (r2 > or = 0.93 for each porcelain shade). Kubelka-Munk theory offers an accurate prediction for the resultant colorimetric reflectance parameters of veneer porcelain bonded to variously colored backings.

  1. Esthetic restorations of maxillary anterior teeth with orthodontic treatment and porcelain laminate veneers: a case report.

    Science.gov (United States)

    Moon, Ji-Eun; Kim, Sung-Hun; Han, Jung-Suk; Yang, Jae-Ho; Lee, Jai-Bong

    2010-06-01

    If orthodontists and restorative dentists establish the interdisciplinary approach to esthetic dentistry, the esthetic and functional outcome of their combined efforts will be greatly enhanced. This article describes satisfying esthetic results obtained by the distribution of space for restoration by orthodontic treatment and porcelain laminate veneers in uneven space between maxillary anterior teeth. It is proposed that the use of orthodontic treatment for re-distribution of the space and the use of porcelain laminate veneers to alter crown anatomy provide maximum esthetic and functional correction for patients with irregular interdental spacing.

  2. Triangulated categories (AM-148)

    CERN Document Server

    Neeman, Amnon

    2014-01-01

    The first two chapters of this book offer a modern, self-contained exposition of the elementary theory of triangulated categories and their quotients. The simple, elegant presentation of these known results makes these chapters eminently suitable as a text for graduate students. The remainder of the book is devoted to new research, providing, among other material, some remarkable improvements on Brown''s classical representability theorem. In addition, the author introduces a class of triangulated categories""--the ""well generated triangulated categories""--and studies their properties. This

  3. Analysis of rare categories

    CERN Document Server

    He, Jingrui

    2012-01-01

    This book focuses on rare category analysis where the majority classes have smooth distributions and the minority classes exhibit the compactness property. It focuses on challenging cases where the support regions of the majority and minority classes overlap.

  4. Consumer Product Category Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Chemical and Product Categories database (CPCat) catalogs the use of over 40,000 chemicals and their presence in different consumer products. The chemical use...

  5. Product Category Management Issues

    OpenAIRE

    Żukowska, Joanna

    2011-01-01

    The purpose of the paper is to present the issues related to category management. It includes the overview of category management definitions and the correct process of exercising it. Moreover, attention is paid to the advantages of brand management, the benefits the supplier and retailer may obtain in this way. The risk element related to this topics is also presented herein. Joanna Żukowska

  6. The Effect of Veneer Layers on the Bending Shear Strength and Delamination of Laminated Veneer Lumber (LVL) from Oil Palm Trunk (OPT)

    Science.gov (United States)

    Jamaludin, M. A.; Nordin, K.; Bahari, S. A.; Ahmad, M.

    2010-03-01

    The aim of this study was to evaluate the effects of the number of veneer layers on the bending shear strength and delamination of Laminated Veneer Lumber (LVL) from oil palm trunk (OPT). Five (5), Six (6) and Seven (7) veneer layers of OPT LVL were manufactured. The dimension of the boards was 45 cm by 45 cm by 1.9 cm. The boards were hot pressed for 13 minutes at a pressure of 31 kgf per m2. Urea formaldehyde (UF) supplied by a local adhesive manufacturer was used as the binder for the boards. The bending shear tests consisted of the edgewise and flatwise tests, whereas the delamination test consisted of the cold and hot water boil tests. The preparation of the test specimens and tests set-up was in accordance to the Japanese Standards, JAS-1991 [1]. Six replications were used for each test. The results were analyzed by Analysis of Variance (ANOVA) using the Duncan's Multiple Range Test to test for significant differences. The results indicated that as the number of layers increased the strength also increased. All the boards passed the standard. The difference in strength between the different types of samples was significant at 95 percent confidence level. Bending shear failures were primarily in the veneers. It is possible to use the boards as light weight interior building and furniture components. Over the years, the supply of quality timber resources from the natural forest has decrease as the wood-based industry experienced rapid growth. The supply of rubberwood for the furniture industry is also decreasing as a result of increase latex price. Accordingly, OPT LVL can be an alternative or supplementary raw material for the wood-based industry.

  7. Influence of abutment type and esthetic veneering on preload maintenance of abutment screw of implant-supported crowns.

    Science.gov (United States)

    Delben, Juliana Aparecida; Barão, Valentim Adelino Ricardo; Dos Santos, Paulo Henrique; Assunção, Wirley Gonçalves

    2014-02-01

    The effect of veneering materials on screw joint stability remains inconclusive. Thus, this study evaluated the preload maintenance of abutment screws of single crowns fabricated with different abutments and veneering materials. Sixty crowns were divided into five groups (n = 12): UCLA abutment in gold alloy with ceramic (group GC) and resin (group GR) veneering, UCLA abutment in titanium with ceramic (group TiC) and resin (group TiR) veneering, and zirconia abutment with ceramic veneering (group ZiC). Abutment screws made of gold were used with a 35 Ncm insertion torque. Detorque measurements were obtained initially and after mechanical cycling. Data were analyzed by ANOVA and Fisher's exact test at a significance level of 5%. For the initial detorque means (in Ncm), group TiC (21.4 ± 1.78) exhibited statistically lower torque maintenance than groups GC (23.9 ± 0.91), GR (24.1 ± 1.34), and TiR (23.2 ± 1.33) (p abutment type and veneering material. More irregular surfaces in the hexagon area of the castable abutments were observed. The superiority of any veneering material concerning preload maintenance was not established. © 2013 by the American College of Prosthodontists.

  8. Role of core support material in veneer failure of brittle layer structures.

    Science.gov (United States)

    Hermann, Ilja; Bhowmick, Sanjit; Lawn, Brian R

    2007-07-01

    A study is made of veneer failure by cracking in all-ceramic crown-like layer structures. Model trilayers consisting of a 1 mm thick external glass layer (veneer) joined to a 0.5 mm thick inner stiff and hard ceramic support layer (core) by epoxy bonding or by fusion are fabricated for testing. The resulting bilayers are then glued to a thick compliant polycarbonate slab to simulate a dentin base. The specimens are subjected to cyclic contact (occlusal) loading with spherical indenters in an aqueous environment. Video cameras are used to record the fracture evolution in the transparent glass layer in situ during testing. The dominant failure mode is cone cracking in the glass veneer by traditional outer (Hertzian) cone cracks at higher contact loads and by inner (hydraulically pumped) cone cracks at lower loads. Failure is deemed to occur when one of these cracks reaches the veneer/core interface. The advantages and disadvantages of the alumina and zirconia core materials are discussed in terms of mechanical properties-strength and toughness, as well as stiffness. Consideration is also given to the roles of interface strength and residual thermal expansion mismatch stresses in relation to the different joining methods. Copyright 2006 Wiley Periodicals, Inc.

  9. Ceramic Veneers and Direct-Composite Cases of Amelogenesis Imperfecta Rehabilitation.

    Science.gov (United States)

    Shibata, S; Taguchi, Cmc; Gondo, R; Stolf, S C; Baratieri, L N

    2016-01-01

    The aim of this article is to present two case reports for the treatment of patients affected with amelogenesis imperfecta. One case was treated with composite resin and the other case with ceramic veneers. Esthetic and functional results were achieved using both treatments, and a review of advantages and disadvantages is presented.

  10. Investigation on the Tribological Behavior and Wear Mechanism of Five Different Veneering Porcelains.

    Directory of Open Access Journals (Sweden)

    Jie Min

    Full Text Available The primary aim of this research was to investigate the wear behavior and wear mechanism of five different veneering porcelains.Five kinds of veneering porcelains were selected in this research. The surface microhardness of all the samples was measured with a microhardness tester. Wear tests were performed on a ball-on-flat PLINT fretting wear machine, with lubrication of artificial saliva at 37°C. The friction coefficients were recorded by the testing system. The microstructure features, wear volume, and damage morphologies were recorded and analyzed with a confocal laser scanning microscope and a scanning electron microscope. The wear mechanism was then elucidated.The friction coefficients of the five veneering porcelains differ significantly. No significant correlation between hardness and wear volume was found for these veneering porcelains. Under lubrication of artificial saliva, the porcelain with higher leucite crystal content exhibited greater wear resistance. Additionally, leucite crystal size and distribution in glass matrix influenced wear behavior. The wear mechanisms for these porcelains were similar: abrasive wear dominates the early stage, whereas delamination was the main damage mode at the later stage. Furthermore, delamination was more prominent for porcelains with larger crystal sizes.Wear compatibility between porcelain and natural teeth is important for dental restorative materials. Investigation on crystal content, size, and distribution in glass matrix can provide insight for the selection of dental porcelains in clinical settings.

  11. Esthetic Rehabilitation of Anterior Teeth with Porcelain Laminates and Sectional Veneers

    NARCIS (Netherlands)

    Gresnigt, Marco; Ozcan, Mutlu

    2011-01-01

    Full-coverage bonded porcelain restorations offer predictable treatment options in dentistry, but a certain amount of tooth material must be removed to allow space for the required thickness of the restorative material. Laminate veneers and inlays are considered minimally invasive, but they also

  12. Illuminating light-dependent color shifts in core and veneer layers of dental all-ceramics

    Science.gov (United States)

    Lee, Yong-Keun; Cha, Hyun-Suk; Yu, Bin

    2014-09-01

    The color of an object is perceived differently depending on the ambient light conditions. Since dental all-ceramic restorations are fabricated by building up several layers to reproduce the tooth shade, the optical properties of each layer should be optimized for successful shade reproduction. This study aimed to determine the separate contributions of the color shifts in each of the core and veneer layers of all-ceramics by switching the illuminating lights on the color shifts of layered ceramics. Specimens of seven kinds of core ceramics and the corresponding veneer ceramics for each core were fabricated with a layered thickness of 1.5 mm. A sintering ceramic was used as a reference core material. The Commission Internationale de l'Eclairage (CIE) color coordinates of core, veneer, and layered specimens were measured with a spectroradiometer under the CIE illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp) simulating lights. Color shifts of the layered specimens were primarily determined by the CIE a* shifts (D65 to A switch) or by the CIE b* shifts (D65 to F9 switch) of the veneer layer. The color coordinates shifts in the constituent layers differentially influenced those of the layered specimens by the kind of switched lights. Therefore, the optical properties of the constituent layers of all-ceramics should be controlled to reflect these findings.

  13. Estimating the spread rate of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer using fluorescence

    Science.gov (United States)

    Toni Antikainen; Anti Rohumaa; Christopher G. Hunt; Mari Levirinne; Mark Hughes

    2015-01-01

    In plywood production, human operators find it difficult to precisely monitor the spread rate of adhesive in real-time. In this study, macroscopic fluorescence was used to estimate spread rate (SR) of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer. This method could be an option when developing automated real-time SR measurement for...

  14. Hardwood Face Veneer and Plywood Mill Closures in Michigan and Wisconsin Since 1950

    Science.gov (United States)

    Lewis T. Hendricks

    1966-01-01

    In recent years there has been a great deal of concern about the closure of numberous hardwood face veneer and plywood mills in Michigan and Wisconsin. As part of an overall study of that industry in the northern Lake States region, the basic reasons leading to the closure of these mills were investigated. In the past 15 years, there have been eight known mill...

  15. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Science.gov (United States)

    Wananuruksawong, R.; Jinawath, S.; Padipatvuthikul, P.; Wasanapiarnpong, T.

    2011-10-01

    Silicon nitride (Si3N4) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si3N4 ceramic as a dental core material. The white Si3N4 was prepared by pressureless sintering at relative low sintering temperature of 1650 °C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si3N4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si3N4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (tube furnace between 1000-1200°C. The veneered specimens fired at 1100°C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98×10-6 °C-1, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  16. Effects of particles thickness and veneer reiforced layer in the properties of oriented strand boards OSB

    Directory of Open Access Journals (Sweden)

    Setsuo Iwakiri

    2009-03-01

    Full Text Available This work evaluated the effects of particle thickness and veneer reinforced layer on the physical and mechanicalproperties of OSB made of Pinus taeda L. The boards were manufactured with particle thickness of 0.4, 0.7 and 1.0 mm and phenolformaldehyderesin in the proportion of 6% of solid content. To the veneer reinforced layer was used veneer from Pinus taeda with 2.0mm of thickness. The increase in the slenderness (length/thickness ratio of thins particles, results in the higher values of MOE andMOR in the cross direction. The increase in the particles thickness contributed to higher values of the board internal bond. Thedifferent particles thickness did not clearly affected on the physical properties of OSB. The veneer reinforced layer results in the higheraverage values of MOE and MOR in the cross direction. All of the results of MOE and MOR obtained for boards with differentthickness attend tominimum values required per CSA 0437 (CSA, 1993. For the internal bond, the results were satisfactory to boardsmanufactured with particles thickness of 0.7 and 1.0 mm. According to the results the main conclusions were: (i The increase in theparticles thickness contributed to lower values of MOE and MOR, and higher values of the board internal bond; (ii the veneerreinforced layer increased MOE and MOR values in the cross direction.

  17. Color management of porcelain veneers: influence of dentin and resin cement colors

    NARCIS (Netherlands)

    Dozic, A.; Tsagkari, M.; Khashayar, G.; Aboushelib, M.

    2010-01-01

    Objective: Porcelain veneers have become an interesting treatment option to correct the shape and color of anterior teeth. Because of their limited thickness and high translucency, achieving a good color match is influenced by several variables. The aim of this work was to investigate the influence

  18. ESTIMATING THE SIZE OF LATE VENEER IMPACTORS FROM IMPACT-INDUCED MIXING ON MERCURY

    International Nuclear Information System (INIS)

    Rivera-Valentin, E. G.; Barr, A. C.

    2014-01-01

    Late accretion of a ''veneer'' of compositionally diverse planetesimals may introduce chemical heterogeneity in the mantles of the terrestrial planets. The size of the late veneer objects is an important control on the angular momenta, eccentricities, and inclinations of the terrestrial planets, but current estimates range from meter-scale bodies to objects with diameters of thousands of kilometers. We use a three-dimensional global Monte Carlo model of impact cratering, excavation, and ejecta blanket formation to show that evidence of mantle heterogeneity can be preserved within ejecta blankets of mantle-exhuming impacts on terrestrial planets. Compositionally distinct provinces implanted at the time of the late veneer are most likely to be preserved in bodies whose subsequent geodynamical evolution is limited. Mercury may have avoided intensive mixing by solid-state convection during much of its history. Its subsequent bombardment may have then excavated evidence of primordial mantle heterogeneity introduced by the late veneer. Simple geometric arguments can predict the amount of mantle material in the ejecta blanket of mantle-exhuming impacts, and deviations in composition relative to geometric predictions can constrain the length-scale of chemical heterogeneities in the subsurface. A marked change in the relationship between mantle and ejecta composition occurs when chemically distinct provinces are ∼250 km in diameter; thus, evidence of bombardment by thousand-kilometer-sized objects should be readily apparent from the variation in compositions of ejecta blankets in Mercury's ancient cratered terrains

  19. Influence of thermal expansion mismatch on residual stress profile in veneering ceramic layered on zirconia: Measurement by hole-drilling.

    Science.gov (United States)

    Mainjot, Amélie K; Najjar, Achref; Jakubowicz-Kohen, Boris D; Sadoun, Michaël J

    2015-09-01

    Mismatch in thermal expansion coefficient between core and veneering ceramic (Δα=αcore-αveneer, ppm/°C) is reported as a crucial parameter influencing veneer fractures with Yttria-tetragonal-zirconia-polycrystal (Y-TZP) prostheses, which still constitutes a misunderstood problem. However, the common positive Δα concept remains empirical. The objective of this study is to investigate the Δα dependence of residual stress profiles in veneering ceramic layered on Y-TZP frameworks. The stress profile was measured with the hole-drilling method in bilayered disc samples of 20mm diameter with a 0.7mm thick Y-TZP framework and a 1.5mm thick veneer layer. 3 commercial and 4 experimental veneering ceramics (n=3 per group) were used to obtain different Δα varying from -1.3ppm/°C to +3.2ppm/°C, which were determined by dilatometric analyses. Veneer fractures were observed in samples with Δα≥+2.3 or ≤-0.3ppm/°C. Residual stress profiles measured in other groups showed compressive stresses in the surface, these stresses decreasing with depth and then becoming more compressive again near the interface. Small Δα variations were shown to induce significant changes in residual stress profiles. Compressive stress near the framework was found to decrease inversely to Δα. Veneer CTE close to Y-TZP (+0.2ppm/°C Δα) gived the most favorable stress profile. Yet, near the framework, Δα-induced residual stress varied inversely to predictions. This could be explained by the hypothesis of structural changes occurrence within the Y-TZP surface. Consequently, the optimum Δα value cannot be determined before understanding Y-TZP's particular behavior when veneered. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  20. Interfacial characterization of ceramic core materials with veneering porcelain for all-ceramic bi-layered restorative systems.

    Science.gov (United States)

    Tagmatarchis, Alexander; Tripodakis, Aris-Petros; Filippatos, Gerasimos; Zinelis, Spiros; Eliades, George

    2014-01-01

    The aim of the study was to characterize the elemental distribution at the interface between all-ceramic core and veneering porcelain materials. Three groups of all-ceramic cores were selected: A) Glass-ceramics (Cergo, IPS Empress, IPS Empress 2, e-max Press, Finesse); B) Glass-infiltrated ceramics (Celay Alumina, Celay Zirconia) and C) Densely sintered ceramics (Cercon, Procera Alumina, ZirCAD, Noritake Zirconia). The cores were combined with compatible veneering porcelains and three flat square test specimens were produced for each system. The core-veneer interfaces were examined by scanning electron microscopy and energy dispersive x-ray microanalysis. The glass-ceramic systems showed interfacial zones reach in Si and O, with the presence of K, Ca, Al in core and Ca, Ce, Na, Mg or Al in veneer material, depending on the system tested. IPS Empress and IPS Empress 2 demonstrated distinct transitional phases at the core-veneer interface. In the glassinfiltrated systems, intermixing of core (Ce, La) with veneer (Na, Si) elements occurred, whereas an abrupt drop of the core-veneer elemental concentration was documented at the interfaces of all densely sintered ceramics. The results of the study provided no evidence of elemental interdiffusion at the core-veneer interfaces in densely sintered ceramics, which implies lack of primary chemical bonding. For the glass-containing systems (glassceramics and glass-infiltrated ceramics) interdiffusion of the glass-phase seems to play a critical role in establishing a primary bonding condition between ceramic core and veneering porcelain.

  1. Models as Relational Categories

    Science.gov (United States)

    Kokkonen, Tommi

    2017-11-01

    Model-based learning (MBL) has an established position within science education. It has been found to enhance conceptual understanding and provide a way for engaging students in authentic scientific activity. Despite ample research, few studies have examined the cognitive processes regarding learning scientific concepts within MBL. On the other hand, recent research within cognitive science has examined the learning of so-called relational categories. Relational categories are categories whose membership is determined on the basis of the common relational structure. In this theoretical paper, I argue that viewing models as relational categories provides a well-motivated cognitive basis for MBL. I discuss the different roles of models and modeling within MBL (using ready-made models, constructive modeling, and generative modeling) and discern the related cognitive aspects brought forward by the reinterpretation of models as relational categories. I will argue that relational knowledge is vital in learning novel models and in the transfer of learning. Moreover, relational knowledge underlies the coherent, hierarchical knowledge of experts. Lastly, I will examine how the format of external representations may affect the learning of models and the relevant relations. The nature of the learning mechanisms underlying students' mental representations of models is an interesting open question to be examined. Furthermore, the ways in which the expert-like knowledge develops and how to best support it is in need of more research. The discussion and conceptualization of models as relational categories allows discerning students' mental representations of models in terms of evolving relational structures in greater detail than previously done.

  2. Metal/silicate partitioning of Pt and the origin of the "late veneer"

    Science.gov (United States)

    Ertel, W.; Walter, M. J.; Drake, M. J.; Sylvester, P. J.

    2002-12-01

    Highly siderophile elements (HSEs) are perfect tools for investigating core forming processes in planetary bodies due to their Fe-loving (siderophile) geochemical behavior. Tremendous scientific effort was invested into this field during the past 10 years - mostly in 1 atm experiments. However, little is known about their high-pressure geochemistry and partitioning behavior between core and mantle forming phases. This knowledge is essential to distinguish between equilibrium (Magma Ocean) and non-equilibrium (heterogeneous accretion, late veneer) models for the accretion history for the early Earth. We therefore chose to investigate the partitioning behavior of Pt up to pressures of 140 kbar (14 GPa) and temperatures of 1950°C. The used melt composition - identical to melt systems used in 1 atm experiments - is the eutectic composition of Anorthite-Diopside (AnDi), a pseudo-basalt. A series of runs were performed which were internaly buffered by the piston cylinder apparatus, and were followed by duplicate experiments buffered in the AnDi-C-CO2 system. These experiments constitute reversals since they approach equilibrium from an initially higher and lower Pt solubility (8 ppm in the non-buffered runs, and essentially Pt free in the buffered runs). Experimental charges were encapsulated in Pt capsules which served as source for Pt. Experiments up to 20 kbar were performed in a Quickpress piston cylinder apparatus, while experiments at higher pressures were performed in a Walker-type (Tucson, AZ) and a Kawai-type (Misasa, Japan) multi anvil apparatus. Time series experiments were performed in piston-cylinder runs to determine minimum run durations for the achievement of equilibrium, and to guarantee high-quality partitioning data. 6 hours was found to be sufficient to obtain equilibrium. In practice, all experiments exceeded 12 hours to assure equilibrium. In a second set of runs the temperature dependence of the partitioning behavior of Pt was investigated between

  3. Categories of transactions

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This chapter discusses the types of wholesale sales made by utilities. The Federal Energy Regulatory Commission (FERC), which regulates inter-utility sales, divides these sales into two broad categories: requirements and coordination. A variety of wholesale sales do not fall neatly into either category. For example, power purchased to replace the Three Mile Island outage is in a sense a reliability purchase, since it is bought on a long-term firm basis to meet basic load requirements. However, it does not fit the traditional model of a sale considered as part of each utility's long range planning. In addition, this chapter discusses transmission services, with a particular emphasis on wheeling

  4. Additively Manufactured Titanium and Cobalt-Chromium Implant Frameworks: Fit and Effect of Ceramic Veneering.

    Science.gov (United States)

    Svanborg, Per; Eliasson, Alf; Stenport, Victoria

    The purpose of this study was to evaluate the fit of additively manufactured cobalt-chromium and titanium and CNC-milled titanium frameworks before and after ceramic veneering. Ten stone casts simulating an edentulous maxilla provided with six abutment analogs were produced. For each stone cast, one additively manufactured cobalt-chromium framework (AM CoCr) and one titanium framework (AM Ti) were fabricated. The fit was analyzed with a coordinate measuring machine in three dimensions (x, y, and z axes) using best-fit virtual matching of center point coordinates, before and after ceramic veneering. CNC-milled titanium frameworks (CNC Ti) and earlier results from CNC-milled cobalt-chromium frameworks (CNC CoCr) were used for comparison. All frameworks presented minor misfit before and after veneering in the horizontal plane (x- and y-axes) between 2.9 and 13.5 μm and in the vertical plane (z-axis) between 1.6 and 5.4 μm. Ceramic veneering affected the fit of all groups of frameworks. Both AM Ti and AM CoCr presented significantly smaller distortion in the vertical plane compared with the CNC-milled frameworks. Implant-supported frameworks can be produced in either Ti or CoCr using either CNC milling or additive manufacturing with a fit well within the range of 20 μm in the horizontal plane and 10 μm in the vertical plane. The fit of frameworks of both materials and production techniques are affected by the ceramic veneering procedure to a small extent.

  5. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Energy Technology Data Exchange (ETDEWEB)

    Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T [Research Unit of Advanced Ceramic, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Padipatvuthikul, P, E-mail: raayaa_chula@hotmail.com [Faculty of Dentistry, Srinakharinwirot University, Bangkok (Thailand)

    2011-10-29

    Silicon nitride (Si{sub 3}N{sub 4}) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si{sub 3}N{sub 4} ceramic as a dental core material. The white Si{sub 3}N{sub 4} was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si{sub 3}N{sub 4} ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si{sub 3}N{sub 4} specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y{sub 2}O{sub 3} - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si{sub 3}N{sub 4} specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10{sup -6} deg. C{sup -1}, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  6. [The effect of core veneer thickness ratio on the flexural strength of diatomite-based dental ceramic].

    Science.gov (United States)

    Jiang, Jie; Zhang, Xin; Gao, Mei-qin; Zhang, Fei-min; Lu, Xiao-li

    2015-06-01

    To evaluate the effect of different core veneer thickness ratios on the flexural strength and failure mode of bilayered diatomite-based dental ceramics. Diatomite-based dental ceramics blocks (16 mm×5.4 mm×1 mm) were sintered with different thickness of veneer porcelains: 0 mm (group A), 0.6 mm (group B), 0.8 mm (group C) and 1.0 mm (group D). Flexural strength was detected and scanning electron microscope was used to observe the interface microstructure. Statistical analysis was performed using SPSS 17.0 software package. With the increase of the thickness of the veneer porcelain, flexural strength of group C showed highest flexural strength up to (277.24±5.47) MPa. Different core veneer thickness ratios can significantly influence the flexural strength of bilayered diatomite-based dental ceramics. Supported by Science and Technology Projects of Nantong City (HS2013010).

  7. Basic category theory

    CERN Document Server

    Leinster, Tom

    2014-01-01

    At the heart of this short introduction to category theory is the idea of a universal property, important throughout mathematics. After an introductory chapter giving the basic definitions, separate chapters explain three ways of expressing universal properties: via adjoint functors, representable functors, and limits. A final chapter ties all three together. The book is suitable for use in courses or for independent study. Assuming relatively little mathematical background, it is ideal for beginning graduate students or advanced undergraduates learning category theory for the first time. For each new categorical concept, a generous supply of examples is provided, taken from different parts of mathematics. At points where the leap in abstraction is particularly great (such as the Yoneda lemma), the reader will find careful and extensive explanations. Copious exercises are included.

  8. CHURCH, Category, and Speciation

    Directory of Open Access Journals (Sweden)

    Rinderknecht Jakob Karl

    2018-01-01

    Full Text Available The Roman Catholic definition of “church”, especially as applied to groups of Protestant Christians, creates a number of well-known difficulties. The similarly complex category, “species,” provides a model for applying this term so as to neither lose the centrality of certain examples nor draw a hard boundary to rule out border cases. In this way, it can help us to more adequately apply the complex ecclesiology of the Second Vatican Council. This article draws parallels between the understanding of speciation and categorization and the definition of Church since the council. In doing so, it applies the work of cognitive linguists, including George Lakoff, Zoltan Kovecses, Giles Fauconnier and Mark Turner on categorization. We tend to think of categories as containers into which we sort objects according to essential criteria. However, categories are actually built inductively by making associations between objects. This means that natural categories, including species, are more porous than we assume, but nevertheless bear real meaning about the natural world. Taxonomists dispute the border between “zebras” and “wild asses,” but this distinction arises out of genetic and evolutionary reality; it is not merely arbitrary. Genetic descriptions of species has also led recently to the conviction that there are four species of giraffe, not one. This engagement will ground a vantage point from which the Council‘s complex ecclesiology can be more easily described so as to authentically integrate its noncompetitive vision vis-a-vis other Christians with its sense of the unique place held by Catholic Church.

  9. Visual memory needs categories

    OpenAIRE

    Olsson, Henrik; Poom, Leo

    2005-01-01

    Capacity limitations in the way humans store and process information in working memory have been extensively studied, and several memory systems have been distinguished. In line with previous capacity estimates for verbal memory and memory for spatial information, recent studies suggest that it is possible to retain up to four objects in visual working memory. The objects used have typically been categorically different colors and shapes. Because knowledge about categories is stored in long-t...

  10. Libertarianism & Category-Mistake

    OpenAIRE

    Carlos G. Patarroyo G.

    2009-01-01

    This paper offers a defense against two accusations according to which libertarianism incurs in a category-mistake. The philosophy of Gilbert Ryle will be used to explain the reasons which ground these accusations. Further, it will be shown why, although certain sorts of libertarianism based on agent-causation or Cartesian dualism incur in these mistakes, there is at least one version of libertarianism to which this criticism does not necessarily apply: the version that seeks to find in physi...

  11. Convergence semigroup categories

    Directory of Open Access Journals (Sweden)

    Gary Richardson

    2013-09-01

    Full Text Available Properties of the category consisting of all objects of the form (X, S, λ are investigated, where X is a convergence space, S is a commutative semigroup, and λ: X × S → X is a continuous action. A “generalized quotient” of each object is defined without making the usual assumption that for each fixed g ∈ S, λ(., g : X  → X is an injection.

  12. Categories and Commutative Algebra

    CERN Document Server

    Salmon, P

    2011-01-01

    L. Badescu: Sur certaines singularites des varietes algebriques.- D.A. Buchsbaum: Homological and commutative algebra.- S. Greco: Anelli Henseliani.- C. Lair: Morphismes et structures algebriques.- B.A. Mitchell: Introduction to category theory and homological algebra.- R. Rivet: Anneaux de series formelles et anneaux henseliens.- P. Salmon: Applicazioni della K-teoria all'algebra commutativa.- M. Tierney: Axiomatic sheaf theory: some constructions and applications.- C.B. Winters: An elementary lecture on algebraic spaces.

  13. The influence of felling season and log-soaking temperature on the wetting and phenol formaldehyde adhesive bonding characteristics of birch veneer

    Science.gov (United States)

    Anti Rohumaa; Christopher G. Hunt; Charles R. Frihart; Pekka Saranpää; Martin Ohlmeyer; Mark Hughes

    2014-01-01

    Most adhesive studies employing wood veneer as the substrate assume that it is a relatively uniform material if wood species and veneer thickness are constant. In the present study, veneers from rotary cut birch (Betula pendula Roth) were produced from logs harvested in spring, autumn and winter, and soaked at 20°C and 70°C prior to peeling. Firstly...

  14. Esthetic, occlusal, and periodontal rehabilitation of anterior teeth with minimum thickness porcelain laminate veneers.

    Science.gov (United States)

    da Cunha, Leonardo Fernandes; Pedroche, Lorena Oliveira; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

    2014-12-01

    Ceramic veneers of minimum thickness provide satisfactory esthetic outcomes while preserving the dental structure. Dental ceramics can both improve the esthetic appearance and reestablish the strength and function of teeth. In worn anterior teeth, functional surfaces, for example, anterior and lateral guidance, can be restored effectively. The characteristics of dental ceramics, such as color stability and mechanical and optical properties, make this material a good choice for indirect restorations, especially when optimum function and esthetics are required. This clinical report presents an occlusal, periodontal, and restorative solution with minimum thickness glass ceramic veneers for worn anterior teeth with multiple diastemas. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  15. Aesthetic composite veneers for an adult patient with amelogenesis imperfecta: a case report.

    Science.gov (United States)

    Brignall, Ian; Mehta, Shamir B; Banerji, Subir; Millar, Brian J

    2011-11-01

    This case has been presented as part of the continual assessment requirement for the MSc in Aesthetic Dentistry, King's College Dental Institute. Amelogenesis imperfecta (AI) is a hereditary disorder of enamel formation, affecting both the permanent and deciduous dentitions. It can be classified into hypoplastic, hypomaturation and hypocalcified types and presents with different hereditary patterns. The aim of this article is to provide an overview of amelogenesis imperfecta, including a detailed case report for an aesthetically concerned adult patient presenting in general practice with a Witkop's Type IA defect managed with the placement of direct, layered resin composite veneers. Amelogenesis imperfecta patients are susceptible to the restorative cycle of replacement restorations like any other patient, but start with a distinct disadvantage.This case report demonstrates a minimally invasive, relatively simple and cost-effective option for the aesthetic correction of a case of hypoplastic amelogenesis imperfecta with layered composite veneers. Dent Update 2011; 38:594-603

  16. LIBERTARISMO & ERROR CATEGORIAL

    Directory of Open Access Journals (Sweden)

    Carlos G. Patarroyo G.

    2009-01-01

    Full Text Available En este artículo se ofrece una defensa del libertarismo frente a dos acusaciones según las cuales éste comete un error categorial. Para ello, se utiliza la filosofía de Gilbert Ryle como herramienta para explicar las razones que fundamentan estas acusaciones y para mostrar por qué, pese a que ciertas versiones del libertarismo que acuden a la causalidad de agentes o al dualismo cartesiano cometen estos errores, un libertarismo que busque en el indeterminismo fisicalista la base de la posibilidad de la libertad humana no necesariamente puede ser acusado de incurrir en ellos.

  17. Libertarianism & Category-Mistake

    Directory of Open Access Journals (Sweden)

    Carlos G. Patarroyo G.

    2009-12-01

    Full Text Available This paper offers a defense against two accusations according to which libertarianism incurs in a category-mistake. The philosophy of Gilbert Ryle will be used to explain the reasons which ground these accusations. Further, it will be shown why, although certain sorts of libertarianism based on agent-causation or Cartesian dualism incur in these mistakes, there is at least one version of libertarianism to which this criticism does not necessarily apply: the version that seeks to find in physical indeterminism the grounding of human free will.

  18. Libertarismo & Error Categorial

    OpenAIRE

    PATARROYO G, CARLOS G

    2009-01-01

    En este artículo se ofrece una defensa del libertarismo frente a dos acusaciones según las cuales éste comete un error categorial. Para ello, se utiliza la filosofía de Gilbert Ryle como herramienta para explicar las razones que fundamentan estas acusaciones y para mostrar por qué, pese a que ciertas versiones del libertarismo que acuden a la causalidad de agentes o al dualismo cartesiano cometen estos errores, un libertarismo que busque en el indeterminismo fisicalista la base de la posibili...

  19. Viscoelastic finite element analysis of residual stresses in porcelain-veneered zirconia dental crowns.

    Science.gov (United States)

    Kim, Jeongho; Dhital, Sukirti; Zhivago, Paul; Kaizer, Marina R; Zhang, Yu

    2018-06-01

    The main problem of porcelain-veneered zirconia (PVZ) dental restorations is chipping and delamination of veneering porcelain owing to the development of deleterious residual stresses during the cooling phase of veneer firing. The aim of this study is to elucidate the effects of cooling rate, thermal contraction coefficient and elastic modulus on residual stresses developed in PVZ dental crowns using viscoelastic finite element methods (VFEM). A three-dimensional VFEM model has been developed to predict residual stresses in PVZ structures using ABAQUS finite element software and user subroutines. First, the newly established model was validated with experimentally measured residual stress profiles using Vickers indentation on flat PVZ specimens. An excellent agreement between the model prediction and experimental data was found. Then, the model was used to predict residual stresses in more complex anatomically-correct crown systems. Two PVZ crown systems with different thermal contraction coefficients and porcelain moduli were studied: VM9/Y-TZP and LAVA/Y-TZP. A sequential dual-step finite element analysis was performed: heat transfer analysis and viscoelastic stress analysis. Controlled and bench convection cooling rates were simulated by applying different convective heat transfer coefficients 1.7E-5 W/mm 2 °C (controlled cooling) and 0.6E-4 W/mm 2 °C (bench cooling) on the crown surfaces exposed to the air. Rigorous viscoelastic finite element analysis revealed that controlled cooling results in lower maximum stresses in both veneer and core layers for the two PVZ systems relative to bench cooling. Better compatibility of thermal contraction coefficients between porcelain and zirconia and a lower porcelain modulus reduce residual stresses in both layers. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Automated knot detection with visual post-processing of Douglas-fir veneer images

    Science.gov (United States)

    C.L. Todoroki; Eini C. Lowell; Dennis Dykstra

    2010-01-01

    Knots on digital images of 51 full veneer sheets, obtained from nine peeler blocks crosscut from two 35-foot (10.7 m) long logs and one 18-foot (5.5 m) log from a single Douglas-fir tree, were detected using a two-phase algorithm. The algorithm was developed using one image, the Development Sheet, refined on five other images, the Training Sheets, and then applied to...

  1. Effect of Provisional Cements on Shear Bond Strength of Porcelain Laminate Veneers

    OpenAIRE

    Altintas, Subutay Han; Tak, Onjen; Secilmis, Asli; Usumez, Aslihan

    2011-01-01

    Objectives: The purpose of this study was to evaluate the effect of three provisional cements and two cleaning techniques on the final bond strength of porcelain laminate veneers. Methods: The occlusal third of the crowns of forty molar teeth were sectioned and embedded in autopolymerizing acrylic resin. Dentin surfaces were polished and specimens were randomly divided into four groups (n=10). Provisional restorations were fabricated and two provisional restorations were cemented onto each to...

  2. Three-unit posterior zirconia-ceramic fixed dental prostheses (FDPs) veneered with layered and milled (CAD-on) veneering ceramics: 1-year follow-up of a randomized controlled clinical trial.

    Science.gov (United States)

    Grohmann, Philipp; Bindl, Andreas; Hämmerle, Christoph; Mehl, Albert; Sailer, Irena

    2015-01-01

    The aim of this multicenter randomized controlled clinical trial was to test posterior zirconia-ceramic fixed dental prostheses (FDPs) veneered with a computer-aided design/computer- assisted manufacture (CAD/CAM) lithium disilicate veneering ceramic (CAD-on) and manually layered zirconia veneering ceramic with respect to survival of the FDPs, and technical and biologic outcomes. Sixty patients in need of one posterior three-unit FDP were included. The zirconia frameworks were produced with a CAD/CAM system (Cerec inLab 3D/Cerec inEOS inLab). Thirty FDPs were veneered with a CAD/CAM lithium disilicate veneering ceramic (Cad-on) (test) and 30 were veneered with a layered zirconia veneering ceramic (control). For the clinical evaluation at baseline, 6, and 12 months, the United States Public Health Service (USPHS) criteria were used. The biologic outcome was judged by comparing the plaque control record (PCR), bleeding on probing (BOP), and probing pocket depth (PPD). Data were statistically analyzed. Fifty-six patients were examined at a mean follow-up of 13.9 months. At the 1-year follow-up the survival rate was 100% in the test and in the control group. No significant differences of the technical outcomes occurred. Major chipping occurred in the control group (n = 3) and predominantly minor chipping in the test group (minor n = 2, major n = 1). No biologic problems or differences were found. Both types of zirconia-ceramic FDPs exhibited very good clinical outcomes without differences between groups. Chipping occurred in both types of FDPs at small amounts, yet the extension of the chippings differed. The test FDPs predominantly exhibited minor chipping, the control FDPs major chipping.

  3. The influence of fire retardants on the properties of beech and poplar veneers and plywood

    Directory of Open Access Journals (Sweden)

    Miljković Jovan

    2005-01-01

    Full Text Available Rising demands for fire resistance properties of wood construction and elements matching new standards have been an important part of building codes during the last decade. On the other side, lack of more detailed research on interaction between wood species and selected fire retardant chemicals even with basically one is evident. This is particularly truth with domestic wood species. In this research, beech and poplar veneers were immersed in 25% solutions of monoammonium phosphate (MP and sodium acetate (SA and impregnated for different periods of time. To determine the preliminary level of fire retardancy achieved in veneers before manufacturing of finished plywood, thermo gravimetric (TG and derivative thermo gravimetric (DTG methods were used. TG and DTG analyses of treated and untreated wood, as well as of fire retardants alone, were performed. The next properties of impregnated and no impregnated veneers and plywood were determined: absorption of imp regnant solution (A, weight percent gain (WPG of imp regnant, equilibrium moisture content (EMC, pH values, and in the case of plywood, strength and fire resistance. Fire resistance of plywood was tested in accordance with standard test for resistance to the effects of fire and the most efficient fire retardant, monoammonium phosphate, had the same result as TG/DTG analyses, which pointed out the validity of TG methods in predicting fire resistance of future products.

  4. Equilibrium moisture content of OSB panels produced with veneer inclusion and different types of adhesive

    Directory of Open Access Journals (Sweden)

    Lourival Marin Mendes

    2014-03-01

    Full Text Available The aim of this study was to evaluate different statistical models to estimate the equilibrium moisture content of OSB panels exposed to different conditions of air temperature and relative humidity, And also to evaluate the influence of the adhesive and veneer inclusion in the equilibrium moisture content. The panels were produced with three different adhesive types (phenol-formaldehyde - FF, melamine-urea-formaldehyde - MUF, and phenol-melamine-urea-formaldehyde - PMUF and with and without veneer inclusion. The evaluation of the equilibrium moisture content of the panels was carried out at temperatures of 30, 40 and 50°C and relative humidity of 40, 50, 60, 70, 80 and 90%. The modeling of equilibrium moisture content was performed using the statistical non-linear and polynomial models. In general, the polynomial models are most indicated for determining the equilibrium moisture content of OSB. The models adjusted only with air relative humidity presented the best precision measurements. The type of adhesive affected the equilibrium moisture content of the panels, being observed for adhesives PMUF and FF the same trend of variation, and the highest values obtained for the panels produced with adhesive MUF. The veneer inclusion decreased the equilibrium moisture content only in the panels with MUF adhesive.

  5. [Interface bond and compatibility between GI-II glass/alumina composite and Vitadur alpha veneering porcelain].

    Science.gov (United States)

    Meng, Yukun; Chao, Yonglie; Liao, Yunmao

    2002-01-01

    Multiple layer techniques were commonly employed in fabricating all-ceramic restorations. Bond and compatibility between layers were vitally important for the clinical success of the restorations. The purposes of this study were to investigate the bond of the interface between the GI-II glass/alumina composite and Vitadur alpha veneering porcelain, and to study the thermal compatibility between them. Prepared a bar shaped specimen of GI-II glass/alumina composite 25 mm x 5 mm x 1 mm in size, with bottom surface pre-notched. The upper surface was veneered with Vitadur alpha veneering porcelain (0.2 mm opaque dentin and 0.6 mm dentin porcelain), then fractured and the fracture surface were examined under scanning electron microscope (SEM) and electron microprobe analyzer (EMPA) with electron beam of 10 micrometer in diameter; ten all-ceramic single crowns for an upper right central incisor were fabricated and the temperatures of thermal shock resistance were tested. SEM observation showed tight bond between the composite and the porcelain; The results of EMPA showed that penetration of Na, Al elements from glass/alumina into veneering porcelain and Si, K, Ca elements from veneering porcelain into glass/alumina occurred after sintering baking; The temperature of thermal shock resistance for anterior crowns in this study was 158 +/- 10.3 degrees C, cracks were mainly distributed in veneering porcelain with thicker layer. Chemical bond exists between the GI-II glass/alumina composite and Vitadur alpha veneering porcelain, and there is good thermal compatibility between them.

  6. Beyond the Categories.

    Science.gov (United States)

    Weeks, Jeffrey

    2015-07-01

    Shushu is a Turkish Cypriot drag performance artist and the article begins with a discussion of a short film about him by a Greek Cypriot playwright, film maker, and gay activist. The film is interesting in its own right as a documentary about a complex personality, but it is also relevant to wider discussion of sexual and gender identity and categorization in a country divided by history, religion, politics, and military occupation. Shushu rejects easy identification as gay or transgender, or anything else. He is his own self. But refusing a recognized and recognizable identity brings problems, and I detected a pervasive mood of melancholy in his portrayal. The article builds from this starting point to explore the problematic nature of identities and categorizations in the contemporary world. The analysis opens with the power of words and language in defining and classifying sexuality. The early sexologists set in motion a whole catalogue of categories which continue to shape sexual thinking, believing that they were providing a scientific basis for a more humane treatment of sexual variations. This logic continues in DSM-5. The historical effect, however, has been more complex. Categorizations have often fixed individuals into a narrow band of definitions and identities that marginalize and pathologize. The emergence of radical sexual-social movements from the late 1960s offered new forms of grassroots knowledge in opposition to the sexological tradition, but at first these movements worked to affirm rather than challenge the significance of identity categories. Increasingly, however, identities have been problematized and challenged for limiting sexual and gender possibilities, leading to the apparently paradoxical situation where sexual identities are seen as both necessary and impossible. There are emotional costs both in affirming a fixed identity and in rejecting one. Shushu is caught in this dilemma, leading to the pervasive sense of loss that shapes the

  7. Veneered zirconia inlay-retained fixed dental prostheses: 10-Year results from a prospective clinical study.

    Science.gov (United States)

    Rathmann, Friederike; Bömicke, Wolfgang; Rammelsberg, Peter; Ohlmann, Brigitte

    2017-09-01

    The purpose of this study was to evaluate the 10-year clinical performance of zirconia-based inlay-retained fixed dental prostheses (IRFDP). For replacement of a molar in 27 patients, 30 IRFDP were luted by use of different cements, Panavia F (Kuraray Europe GmbH) or Multilink Automix (Ivoclar Vivadent GmbH), with use of inlay/inlay, inlay/full-crown, or inlay/partial-crown retainers for anchorage. Frameworks were milled from yttria-stabilized zirconia (IPS e.maxZirCAD; Ivoclar Vivadent GmbH) and fully veneered with pressable ceramic (IPS e.max ZirPress; Ivoclar Vivadent GmbH). Before luting, the IRFDP were silica-coated (Rocatec; 3M Espe) and silanized (Monobond S; Ivoclar Vivadent GmbH). Complications (for example, chipping or delamination of the veneering ceramic, debonding, secondary caries, endodontic treatment, and abutment tooth fracture) and failure were reported, by use of standardized report forms, 2 weeks, 6 months, and 1, 2, and 10 years after cementation. Statistical analysis included Kaplan-Meier survival and success (complication-free survival) and Cox regression analysis (α=0.05 for all). During the 10-year observation period, the complications most often observed were chipping of the veneer and debonding. Twenty-five restorations failed and one participant dropped out. Cumulative 10-year survival and success were 12.1% and 0%, respectively. The design of the retainer, use of a dental dam, choice of cement, and location in the dental arch had no statistically significant effect on the occurrence of complications. Use of fully veneered zirconia-based IRFDP with this technique cannot be recommended. A large incidence of complications and poor survival were observed for fully veneered zirconia-based IRFDP, revealing an urgent need for further design improvements for this type of restoration. This, again, emphasizes the need for testing of new restoration designs in clinical trials before implementation in general dental practice. Copyright © 2017

  8. Effect of various veneering techniques on mechanical strength of computer-controlled zirconia framework designs.

    Science.gov (United States)

    Kanat, Burcu; Cömlekoğlu, Erhan M; Dündar-Çömlekoğlu, Mine; Hakan Sen, Bilge; Ozcan, Mutlu; Ali Güngör, Mehmet

    2014-08-01

    The objectives of this study were to evaluate the fracture resistance (FR), flexural strength (FS), and shear bond strength (SBS) of zirconia framework material veneered with different methods and to assess the stress distributions using finite element analysis (FEA). Zirconia frameworks fabricated in the forms of crowns for FR, bars for FS, and disks for SBS (N = 90, n = 10) were veneered with either (a) file splitting (CAD-on) (CD), (b) layering (L), or (c) overpressing (P) methods. For crown specimens, stainless steel dies (N = 30; 1 mm chamfer) were scanned using the labside contrast spray. A bilayered design was produced for CD, whereas a reduced design (1 mm) was used for L and P to support the veneer by computer-aided design and manufacturing. For bar (1.5 × 5 × 25 mm(3) ) and disk (2.5 mm diameter, 2.5 mm height) specimens, zirconia blocks were sectioned under water cooling with a low-speed diamond saw and sintered. To prepare the suprastructures in the appropriate shapes for the three mechanical tests, nano-fluorapatite ceramic was layered and fired for L, fluorapatite-ceramic was pressed for P, and the milled lithium-disilicate ceramics were fused with zirconia by a thixotropic glass ceramic for CD and then sintered for crystallization of veneering ceramic. Crowns were then cemented to the metal dies. All specimens were stored at 37°C, 100% humidity for 48 hours. Mechanical tests were performed, and data were statistically analyzed (ANOVA, Tukey's, α = 0.05). Stereomicroscopy and scanning electron microscopy (SEM) were used to evaluate the failure modes and surface structure. FEA modeling of the crowns was obtained. Mean FR values (N ± SD) of CD (4408 ± 608) and L (4323 ± 462) were higher than P (2507 ± 594) (p mechanical tests, whereas a layering technique increased the FR when an anatomical core design was employed. File splitting (CAD-on) or layering veneering ceramic on zirconia with a reduced framework design may reduce ceramic chipping

  9. Effectiveness of optical illusions 
applied on a single composite resin veneer for the diastema closure 
of maxillary central incisors.

    Science.gov (United States)

    Katsarou, Thomai; Antoniadou, Maria; Papazoglou, Efstratios

    To assess the esthetic effectiveness of four illusion techniques applied to a composite resin veneer for diastema closure between maxillary central incisors. An acrylic model with six natural maxillary anterior teeth was fabricated with a 2-mm diastema between the central incisors. Resin veneers were constructed on the left central incisor and the following cases were derived: V0: no veneer; V1: veneer without optical illusion features; V2: veneer with centralized interproximal ridges; V3: veneer with curved incisal edges; V4: veneer with gray pigment mesially/distally; V5: veneer with gray pigment on the developmental lobes. Digital printed photos of the models (13.2 x 17.8 cm, and 6.1 x 8 cm), with low, medium, and high smile lines and without a smile line (processed by Adobe Photoshop CS6) were shown to three groups of people (faculty members, senior undergraduate students, and patients; n = 25/group) for them to assess the overall size and width of the two central incisors. The results were analyzed by Pearson's and chi-square goodness of fit tests. There was no significant influence in the estimation of the two central incisors as being the same size, according to the technique used (P = 0.869) and group of evaluators (P = 0.209). The estimated probability of assessing the tested incisor as wider was indicatively lower in V2 compared to V1 (adjusted odds ratio = 0.59; P = 0.088). The height of the smile line affected the evaluation of the veneers only in the large-sized photos. No interference is the best esthetic decision concerning a 2-mm diastema closure when restoring only one central incisor with a laminate veneer. The next best option is to deliver a veneer with centralized interproximal ridges.

  10. Categories for Observing Language Arts Instruction (COLAI).

    Science.gov (United States)

    Benterud, Julianna G.

    Designed to study individual use of time spent in reading during regularly scheduled language arts instruction in a natural classroom setting, this coding sheet consists of nine categories: (1) engagement, (2) area of language arts, (3) instructional setting, (4) partner (teacher or pupil(s)), (5) source of content, (6) type of unit, (7) assigned…

  11. Influence of Different Types of Resin Luting Agents on Color Stability of Ceramic Laminate Veneers Subjected to Accelerated Artificial Aging.

    Science.gov (United States)

    Silami, Francisca Daniele Jardilino; Tonani, Rafaella; Alandia-Román, Carla Cecilia; Pires-de-Souza, Fernanda de Carvalho Panzeri

    2016-01-01

    The aim of this study was to evaluate the influence of accelerated aging (AAA) on the color stability of resin cements for bonding ceramic laminate veneers of different thicknesses. The occlusal surfaces of 80 healthy human molars were flattened. Ceramic laminate veneers (IPS e-max Ceram) of two thicknesses (0.5 and 1.0 mm) were bonded with three types of luting agents: light-cured, conventional dual and self-adhesive dual cement. Teeth without restorations and cement samples (0.5 mm) were used as control. After initial color evaluations, the samples were subjected to AAA for 580 h. After this, new color readouts were made, and the color stability (ΔE) and luminosity (ΔL) data were analyzed. The greatest color changes (p<0.05) occurred when 0.5 mm veneers were fixed with light-cured cement and the lowest when 1.0 mm veneers were fixed with conventional dual cement. There was no influence of the restoration thickness when the self-adhesive dual cement was used. When veneers were compared with the control groups, it was verified that the cement samples presented the greatest alterations (p<0.05) in comparison with both substrates and restored teeth. Therefore, it was concluded that the thickness of the restoration influences color and luminosity changes for conventional dual and light-cured cements. The changes in self-adhesive cement do not depend on restoration thickness.

  12. Evaluation of the use potential of nine species of genus Eucalyptus for production of veneers and plywood panels

    Directory of Open Access Journals (Sweden)

    Setsuo Iwakiri

    2013-06-01

    Full Text Available The objective of thisstudywas to evaluate the use potential of nine species of Eucalyptus for production of veneer sheets and multilaminated plywood panels. Veneers were cut using a pilot laminating lathe to a nominal thickness of 2.0 mm. Analysis included finding values of overall yield and yield according to three quality classes for the nine relevant species. Plywood panels were manufactured in a laboratory, consisting of five 2.0 mm veneer sheets which were bonded together with phenol-formaldehyde resin at a weight of 360 g/m2 (double line. The panels were compressed using a specific pressure of 10 kgf/cm2, a temperature of 140ºC and a pressing time of 10 minutes. Results indicated that, with the exception of E. phaeotricha and E. pellita, all other Eucalyptus species had above 50% average veneer yield after lamination. Results of glue line shear testing and static bending parallel and perpendicular demonstrated that species Eucalyptus grandis, Eucalyptus saligna, Eucalyptus dunnii, Eucalyptus globulus, Eucalyptus viminalis, Eucalyptus robusta and Eucalyptus pellita have great potential within the parameters of this study for use in the production of veneer sheets and plywood panels intended for outdoor use.

  13. Language categories in Russian morphology

    OpenAIRE

    زهرایی زهرایی

    2009-01-01

    When studying Russian morphology, one can distinguish two categories. These categories are “grammatical” and “lexico-grammatical”. Grammatical categories can be specified through a series of grammatical features of words. Considering different criteria, Russian grammarians and linguists divide grammatical categories of their language into different types. In determining lexico-grammatical types, in addition to a series of grammatical features, they also consider a series of lexico-semantic fe...

  14. Reliability and failure modes of implant-supported zirconium-oxide fixed dental prostheses related to veneering techniques

    Science.gov (United States)

    Baldassarri, Marta; Zhang, Yu; Thompson, Van P.; Rekow, Elizabeth D.; Stappert, Christian F. J.

    2011-01-01

    Summary Objectives To compare fatigue failure modes and reliability of hand-veneered and over-pressed implant-supported three-unit zirconium-oxide fixed-dental-prostheses(FDPs). Methods Sixty-four custom-made zirconium-oxide abutments (n=32/group) and thirty-two zirconium-oxide FDP-frameworks were CAD/CAM manufactured. Frameworks were veneered with hand-built up or over-pressed porcelain (n=16/group). Step-stress-accelerated-life-testing (SSALT) was performed in water applying a distributed contact load at the buccal cusp-pontic-area. Post failure examinations were carried out using optical (polarized-reflected-light) and scanning electron microscopy (SEM) to visualize crack propagation and failure modes. Reliability was compared using cumulative-damage step-stress analysis (Alta-7-Pro, Reliasoft). Results Crack propagation was observed in the veneering porcelain during fatigue. The majority of zirconium-oxide FDPs demonstrated porcelain chipping as the dominant failure mode. Nevertheless, fracture of the zirconium-oxide frameworks was also observed. Over-pressed FDPs failed earlier at a mean failure load of 696 ± 149 N relative to hand-veneered at 882 ± 61 N (profile I). Weibull-stress-number of cycles-unreliability-curves were generated. The reliability (2-sided at 90% confidence bounds) for a 400N load at 100K cycles indicated values of 0.84 (0.98-0.24) for the hand-veneered FDPs and 0.50 (0.82-0.09) for their over-pressed counterparts. Conclusions Both zirconium-oxide FDP systems were resistant under accelerated-life-time-testing. Over-pressed specimens were more susceptible to fatigue loading with earlier veneer chipping. PMID:21557985

  15. The effect of veneering and heat treatment on the flexural strength of Empress 2 ceramics.

    Science.gov (United States)

    Cattell, M J; Palumbo, R P; Knowles, J C; Clarke, R L; Samarawickrama, D Y D

    2002-05-01

    The aims of the study were to test and compare the biaxial flexural strength and reliability of Empress 2 ceramics after heat treatment and the addition of the veneering material and to characterise their microstructures. Forty disc specimens (2 x 14 mm) and forty disc specimens (1 x 14 mm) were produced by heat pressing in the EP 500 press furnace. Group 1 (2 x 14 mm Empress 2 core) was as heat pressed and group 2 (2 x 14 mm Empress 2 core) was subjected to the recommended firing cycles. Groups 3 and 4 (1 x 14 mm Empress 2 core) were veneered with the dentine material and heat-treated as per group 2. Groups 1, 2 and 3 were lapped to 800 grit silicon carbide paper on the compressive surface only and group 4 on both the compressive and tensile test surfaces. Twenty disc specimens per group were tested using the biaxial flexure test at a crosshead speed of 0.15 mm/min. Specimens were characterised using X-ray diffraction (XRD) and secondary electron imaging (SEM). Mean biaxial flexural strengths (MPa+/-SD) were group 1: 265.5+/-25.7; group 2: 251.3+/-30.2; group 3: 258.6+/-21.4 and group 4: 308.6+/-37.7. There was no statistical difference between groups 1, 2 and 3 (p>0.05), but differences for group 4 (pEmpress 2 core material and an amorphous glass and some evidence of a crystalline phase in the dentine material. CONCLUSIONS; Veneering or heat treatment of Empress 2 ceramics did not significantly affect the mean biaxial flexural strength (p>0.05) or reliability. Surface modification of the Empress 2 core material increased the mean biaxial flexural strength (p<0.05).

  16. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  17. Subject categories and scope descriptions

    International Nuclear Information System (INIS)

    2002-01-01

    This document is one in a series of publications known as the ETDE/INIS Joint Reference Series. It defines the subject categories and provides the scope descriptions to be used for categorization of the nuclear literature for the preparation of INIS and ETDE input by national and regional centres. Together with the other volumes of the INIS Reference Series it defines the rules, standards and practices and provides the authorities to be used in the International Nuclear Information System and ETDE. A complete list of the volumes published in the INIS Reference Series may be found on the inside front cover of this publication. This INIS/ETDE Reference Series document is intended to serve two purposes: to define the subject scope of the International Nuclear Information System (INIS) and the Energy Technology Data Exchange (ETDE) and to define the subject classification scheme of INIS and ETDE. It is thus the guide to the inputting centres in determining which items of literature should be reported, and in determining where the full bibliographic entry and abstract of each item should be included in INIS or ETDE database. Each category is identified by a category code consisting of three alphanumeric characters. A scope description is given for each subject category. The scope of INIS is the sum of the scopes of all the categories. With most categories cross references are provided to other categories where appropriate. Cross references should be of assistance in finding the appropriate category; in fact, by indicating topics that are excluded from the category in question, the cross references help to clarify and define the scope of the category to which they are appended. A Subject Index is included as an aid to subject classifiers, but it is only an aid and not a means for subject classification. It facilitates the use of this document, but is no substitute for the description of the scope of the subject categories

  18. Bruxism in prospective studies of veneered zirconia restorations-a systematic review.

    Science.gov (United States)

    Schmitter, Marc; Boemicke, Wolfgang; Stober, Thomas

    2014-01-01

    The objectives of this work were to systematically review the effect of bruxism on the survival of zirconia restorations on teeth and to assess the prevalence of nocturnal masseter muscle activity in a clinical sample. A Medline search was performed independently and in triplicate using the term "zirconia" and activating the filter "clinical trial." Furthermore, three other electronic databases were searched using the same term. Only papers published in English on prospective studies of veneered zirconia frameworks on teeth were included. To estimate the prevalence of sleep bruxism in clinical settings, subjects with no clinical signs of bruxism and who did not report grinding and/or clenching were examined by use of a disposable electromyographic device. The initial search resulted in 107 papers, of which 22 were included in the analysis. Bruxers were excluded in 20 of these articles. In 1 study bruxers were not excluded, and 1 study did not provide information regarding this issue. The methods used to identify bruxers were heterogeneous/not described, and no study used reliable, valid methods. Of 33 subjects without clinical signs of bruxism, nocturnal muscle activity exceeded predefined muscle activity for 63.8% of the subjects. There is a lack of information about the effect of bruxism on the incidence of technical failure of veneered zirconia restorations because all available studies failed to use suitable instruments for diagnosis of bruxism. Nocturnal muscle activity without clinical symptoms/report of bruxism was observed for a relevant number of patients.

  19. Visual versus Colorimetric Data Analysis for Color Determination in Resin Veneers

    Directory of Open Access Journals (Sweden)

    Raluca DIMA

    2012-03-01

    Full Text Available The color of natural teeth depends on their capacity to modify the incident light (to change the wave length of incident light. Mainly two types of observation modes are used: diffuse illumination 0% and 45%; the angles represent incidence of illumination and observation on the surface of the object whose color is determined. The patients have been properly selected to receive direct resin veneers on their frontal maxillary incisors. Visually we observed and determined color directly using natural incident light between 10 am and 16 pm, the observer was positioned away from patient so the tooth to examine was at the level of observer’s eye (incidence angles were mainly similar. Vita Easy Shade colorimeter was used to establish the color of the restoration before and after it was performed. The Expanded Visual Rating Scale for Appearance Match (EVRSAM supplied statistically comparable data as the literature; the comparison between visual and colorimetric data makes us suppose that visual color determination is a necessary but not sufficient tool for the esthetic success of any veneer restoration.

  20. Radiation protection in category III large gamma irradiators

    International Nuclear Information System (INIS)

    Costa, Neivaldo; Furlan, Gilberto Ribeiro; Itepan, Natanael Marcio

    2011-01-01

    This article discusses the advantages of category III large gamma irradiator compared to the others, with emphasis on aspects of radiological protection, in the industrial sector. This category is a kind of irradiators almost unknown to the regulators authorities and the industrial community, despite its simple construction and greater radiation safety intrinsic to the model, able to maintain an efficiency of productivity comparable to those of category IV. Worldwide, there are installed more than 200 category IV irradiators and there is none of a category III irradiator in operation. In a category III gamma irradiator, the source remains fixed in the bottom of the tank, always shielded by water, negating the exposition risk. Taking into account the benefits in relation to radiation safety, the category III large irradiators are highly recommended for industrial, commercial purposes or scientific research. (author)

  1. How categories come to matter

    DEFF Research Database (Denmark)

    Leahu, Lucian; Cohn, Marisa; March, Wendy

    2013-01-01

    In a study of users' interactions with Siri, the iPhone personal assistant application, we noticed the emergence of overlaps and blurrings between explanatory categories such as "human" and "machine". We found that users work to purify these categories, thus resolving the tensions related to the ...... initial data analysis, due to our own forms of latent purification, and outline the particular analytic techniques that helped lead to this discovery. We thus provide an illustrative case of how categories come to matter in HCI research and design.......In a study of users' interactions with Siri, the iPhone personal assistant application, we noticed the emergence of overlaps and blurrings between explanatory categories such as "human" and "machine". We found that users work to purify these categories, thus resolving the tensions related...

  2. The composition of category conjunctions.

    Science.gov (United States)

    Hutter, Russell R C; Crisp, Richard J

    2005-05-01

    In three experiments, the authors investigated the impression formation process resulting from the perception of familiar or unfamiliar social category combinations. In Experiment 1, participants were asked to generate attributes associated with either a familiar or unfamiliar social category conjunction. Compared to familiar combinations, the authors found that when the conjunction was unfamiliar, participants formed their impression less from the individual constituent categories and relatively more from novel emergent attributes. In Experiment 2, the authors replicated this effect using alternative experimental materials. In Experiment 3, the effect generalized to additional (orthogonally combined) gender and occupation categories. The implications of these findings for understanding the processes involved in the conjunction of social categories, and the formation of new stereotypes, are discussed.

  3. Effect of luting agent on the load to failure and accelerated-fatigue resistance of lithium disilicate laminate veneers

    NARCIS (Netherlands)

    Gresnigt, Marco M. M.; Ozcan, Mutlu; Carualho, Marco; Lazari, Priscilla; Cune, Marco S.; Razavi, Peywand; Magne, Pascal

    2017-01-01

    Objective. The aim of this study was to investigate the influence of the luting agent on the application of laminate veneers (LVs) in an accelerated fatigue and load-to-failure test after thermo-cyclic aging. Methods. Sound maxillary central incisors (N = 40) were randomly divided into four groups

  4. Effect of immediate and delayed dentin sealing on the fracture strength, failure type and Weilbull characteristics of lithiumdisilicate laminate veneers

    NARCIS (Netherlands)

    Gresnigt, Marco M.M.; Cune, Marco S.; de Roos, Joanne G.; Özcan, Mutlu

    OBJECTIVES: Adhesion on dentin is less reliable than on enamel, which could affect the durability of laminate veneers (LV). Immediate dentin sealing (IDS) is suggested instead of delayed dentin sealing (DDS) to overcome hypersensitivity and prevent debonding from dentin. This study evaluated the

  5. Foam Core Particleboards with Intumescent FRT Veneer: Cone Calorimeter Testing With Varying Adhesives, Surface Layer Thicknesses, and Processing Conditions

    Science.gov (United States)

    Mark A. Dietenberger; Johannes Welling; Ali Shalbafan

    2014-01-01

    Intumescent FRT Veneers adhered to the surface of foam core particleboard to provide adequate fire protection were evaluated by means of cone calorimeter tests (ASTM E1354). The foam core particleboards were prepared with variations in surface layer treatment, adhesives, surface layer thicknesses, and processing conditions. Ignitability, heat release rate profile, peak...

  6. The influence of log soaking temperature on surface quality and integrity performance of birch (Betula pendula Roth) veneer

    Science.gov (United States)

    Anti Rohumaa; Toni Antikainen; Christopher G. Hunt; Charles R. Frihart; Mark Hughes

    2016-01-01

    Wood material surface properties play an important role in adhesive bond formation and performance. In the present study, a test method was developed to evaluate the integrity of the wood surface, and the results were used to understand bond performance. Materials used were rotary cut birch (Betula pendula Roth) veneers, produced from logs soaked at 20 or 70 °C prior...

  7. Effect of Static and Cyclic Loading on Ceramic Laminate Veneers Adhered to Teeth with and Without Aged Composite Restorations

    NARCIS (Netherlands)

    Gresnigt, Marco M. M.; Ozcan, Mutlu; Kalk, Warner; Galhano, Graziela

    2011-01-01

    Purpose: Existing composite restorations on teeth are often remade prior to the cementation of fixed dental prostheses. The aim of this study was to evaluate the effect of static and cyclic loading on ceramic laminate veneers adhered to aged resin composite restorations. Materials and Methods:

  8. Randomized Clinical Trial of Indirect Resin Composite and Ceramic Veneers : Up to 3-year Follow-up

    NARCIS (Netherlands)

    Gresnigt, Marco M. M.; Kalk, Warner; Ozcan, Mutlu

    2013-01-01

    Purpose: This randomized controlled split-mouth clinical trial evaluated the short-term survival rate of indirect resin composite and ceramic laminate veneers. Materials and Methods: A total of 10 patients (mean age: 48.6 years) received 46 indirect resin composite (Estenia; n = 23) and ceramic

  9. Survival of ceramic veneers made of different materials after a minimum follow-up period of five years: a systematic review and meta-analysis.

    Science.gov (United States)

    Petridis, Haralampos P; Zekeridou, Alkisti; Malliari, Maria; Tortopidis, Dimitrios; Koidis, Petros

    2012-01-01

    The purpose of this systematic review was to compare the survival and complication rates of ceramic veneers produced with different techniques and materials after a minimum follow-up time of 5 years. A literature search was conducted, using electronic databases, relevant references, citations and journal researching, for clinical studies reporting on the survival of ceramic veneers fabricated with different techniques and materials with a mean followup time of at least 5 years. The search period spanned from January 1980 up to October 2010. Event rates were calculated for the following complications associated with ceramic veneers: fracture, debonding, marginal discoloration, marginal integrity, and caries. Summary estimates, and 5-year event rates were reported. Comparison between subgroups of different materials, as well as statistical significance, was calculated using a mixed effects model. Nine studies were selected for final analysis over an initial yield of 409 titles. No study directly compared the incidence of complications between ceramic veneers fabricated from different materials. Four of the included studies reported on the survival of ceramic veneers made out of feldspathic ceramics; four studies were on glass-ceramic veneers and one study included veneers fabricated from both materials. The mean observation time ranged between 5 and 10 years. Overall, the 5-year complication rates were low, with the exception of studies reporting on extended ceramic veneers. The most frequent complication reported was marginal discoloration (9% at 5 years), followed by marginal integrity (3.9-7.7% at 5 years). There was no statistically significant difference in the event rates between the subgroups of different materials (feldspathic vs. glass-ceramic). The results of this systematic review showed that ceramic veneers fabricated from feldspathic or glass-ceramics have an adequate clinical survival for at least 5 years of clinical service, with very low complication

  10. Residual stress profiles in veneering ceramic on Y-TZP, alumina and ZTA frameworks: measurement by hole-drilling.

    Science.gov (United States)

    Fukushima, K A; Sadoun, M J; Cesar, P F; Mainjot, A K

    2014-02-01

    The residual stress profile developed within the veneering ceramic during the manufacturing process is an important predicting factor in chipping failures, which constitute a well-known problem with yttria-tetragonal-zirconia polycrystal (Y-TZP) based restorations. The objectives of this study are to measure and to compare the residual stress profile in the veneering ceramic layered on three different polycrystalline ceramic framework materials: Y-TZP, alumina polycrystal (AL) and zirconia toughened alumina (ZTA). The stress profile was measured with the hole-drilling method in bilayered disk samples of 19 mm diameter with a 0.7 mm thick Y-TZP, AL or ZTA framework and a 1.5mm thick layer of the corresponding veneering ceramic. The AL samples exhibited increasing compressive stresses with depth, while compressive stresses switching into interior tensile stresses were measured in Y-TZP samples. ZTA samples exhibited compressive stress at the ceramic surface, decreasing with depth up to 0.6mm from the surface, and then becoming compressive again near the framework. Y-TZP samples exhibited a less favorable stress profile than those of AL and ZTA samples. Results support the hypothesis of the occurrence of structural changes within the Y-TZP surface in contact with the veneering ceramic to explain the presence of tensile stresses. Even if the presence of Y-TZP in the alumina matrix seems to negatively affect the residual stress profiles in ZTA samples in comparison with AL samples, the registered profiles remain positive in terms of veneer fracture resistance. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  11. How do Category Managers Manage?

    DEFF Research Database (Denmark)

    Hald, Kim Sundtoft; Sigurbjornsson, Tomas

    2013-01-01

    The aim of this research is to explore the managerial role of category managers in purchasing. A network management perspective is adopted. A case based research methodology is applied, and three category managers managing a diverse set of component and service categories in a global production...... firm is observed while providing accounts of their progress and results in meetings. We conclude that the network management classification scheme originally deve loped by Harland and Knight (2001) and Knight and Harland (2005) is a valuable and fertile theoretical framework for the analysis...

  12. Short-Term Prospective Clinical Evaluation of Monolithic and Partially Veneered Zirconia Single Crowns.

    Science.gov (United States)

    Bömicke, Wolfgang; Rammelsberg, Peter; Stober, Thomas; Schmitter, Marc

    2017-02-01

    The purpose of this study was to prospectively evaluate the short-term clinical performance and esthetics of monolithic and partially (i.e., facially) veneered zirconia single crowns (MZC and PZC, respectively). Between September 2011 and June 2013, 68 participants received 90 MZCs and 72 PZCs. Clinical study documentation was performed at crown cementation (baseline), at the 6-month follow-up, and then yearly thereafter using standardized report forms. Eight participants with 14 single crowns (eight MZCs and six PZCs) dropped out during clinical follow-up. Thus, 60 participants (28 male, mean age 62.5 ± 13.1 years) fitted with 82 MZCs and 66 PZCs were analyzed in February 2016 (Kaplan-Meier survival; mean observation time for the restorations 35.1 ± 6.3 months). Descriptive statistics were calculated for participants' and dentists' esthetic ratings on a numerical rating scale from 0 to 10 (0 = unacceptable color and shape; 10 = excellent color and shape). Complications were predominantly biological in nature. One PZC was affected by minor chipping. Cumulative 3-year failure-free survival was 98.5% (standard error (SE), 1.5%) for both MZCs and PZCs. Three-year cumulative complication-free survival (success) was 93.6% (SE 2.8%) for MZCs and 95.5% (SE 2.6%) for PZCs. Three-year cumulative fracture-free survival was 100% for MZCs and 98.5% (SE 1.5%) for PZCs. Crowns of both types were awarded high esthetic scores by participants and dentists. Monolithic and partially veneered zirconia crowns can be used clinically with excellent short-term survival and success and without compromising esthetic appearance. Longer-term follow-up is, however, desirable. During the observation time, both monolithic and partially veneered zirconia crowns showed an outstanding low technical complication rate: only one minor chipping and three losses of retention were observed. Additionally, esthetics was excellent. Based on these results the clinical use of this kind of

  13. Homological algebra in -abelian categories

    Indian Academy of Sciences (India)

    Deren Luo

    2017-08-16

    Aug 16, 2017 ... Homological algebra in n-abelian categories. 627. We recall the Comparison lemma, together with its dual, plays a central role in the sequel. Lemma 2.1 [13, Comparison lemma 2.1]. Let C be an additive category and X ∈ Ch. ≥0(C) a complex such that for all k ≥ 0the morphism dk+1. X is a weak cokernel ...

  14. Data categories for marine planning

    Science.gov (United States)

    Lightsom, Frances L.; Cicchetti, Giancarlo; Wahle, Charles M.

    2015-01-01

    The U.S. National Ocean Policy calls for a science- and ecosystem-based approach to comprehensive planning and management of human activities and their impacts on America’s oceans. The Ocean Community in Data.gov is an outcome of 2010–2011 work by an interagency working group charged with designing a national information management system to support ocean planning. Within the working group, a smaller team developed a list of the data categories specifically relevant to marine planning. This set of categories is an important consensus statement of the breadth of information types required for ocean planning from a national, multidisciplinary perspective. Although the categories were described in a working document in 2011, they have not yet been fully implemented explicitly in online services or geospatial metadata, in part because authoritative definitions were not created formally. This document describes the purpose of the data categories, provides definitions, and identifies relations among the categories and between the categories and external standards. It is intended to be used by ocean data providers, managers, and users in order to provide a transparent and consistent framework for organizing and describing complex information about marine ecosystems and their connections to humans.

  15. Occupational health and safety issues in Ontario sawmills and veneer/plywood plants: a pilot study.

    Science.gov (United States)

    Verma, Dave K; Demers, Cecil; Shaw, Don; Verma, Paul; Kurtz, Lawrence; Finkelstein, Murray; des Tombe, Karen; Welton, Tom

    2010-01-01

    A pilot study was conducted within the Ontario sawmill and veneer/plywood manufacturing industry. Information was collected by postal questionnaire and observational walk-through surveys. Industrial hygiene walk-through surveys were conducted at 22 work sites, and measurements for wood dust, noise, and bioaerosol were taken. The aim of the study was to obtain data on the current status regarding health and safety characteristics and an estimate of wood dust, noise, and bioaerosol exposures. The occupational exposure to wood dust and noise are similar to what has been reported in this industry in Canada and elsewhere. Airborne wood dust concentration ranged between 0.001 mg/m³ and 4.87 mg/m³ as total dust and noise exposure ranged between 55 and 117 dB(A). The study indicates the need for a more comprehensive industry-wide study of wood dust, noise, and bioaersols.

  16. Design of pedestrian truss bridge with Sengon-Rubber laminated veneer lumber

    Science.gov (United States)

    Herbudiman, B.; Pranata, Y. A.; Pangestu, L.

    2017-12-01

    Timber bridges are one of the bridge that has long been used, but nowadays, large dimension of sawn timber has limited supply and also it is not environmental-friendly. Laminated veneer lumber (LVL) is a engineered wood that becomes one of the promising alternative, because it is made from lower quality wood that processed to be used as a more quality one. The bridge planned to be a pedestrian truss bridge with length of 9 m, width of 3 m, height of 2.5 m, and using bolt and steel plate as its connection system. Mechanical properties of LVL obtained directly from laboratory test result. Bridge modeling and planning for wood construction refers to SNI 7973:2013, while the loading refers to SNI 1725:2016. Based on the modelling and calculation, the dimension of truss frame and girder beam which are 9 cm x 9 cm and 9 cm x 18 cm have adequate strengths and satisfy deflection requirement.

  17. Effects of multiple firings on the microstructure of zirconia and veneering ceramics.

    Science.gov (United States)

    Alkurt, Murat; Yeşil Duymus, Zeynep; Gundogdu, Mustafa

    2016-01-01

    The aim of study was to evaluate the effects of multiple firings on the microstructures of zirconia and two ceramics. Vita VM9 (VMZ) and Cerabien ZR (C-Z) ceramics on a zirconia framework and zirconia without veneering ceramic (WO-Z) were evaluated. Firing methods included firing two, five, and ten times (n=10). The effects of multiple firings on the surface hardness of the materials were evaluated using a Vickers hardness (HV) tester. Data were analyzed by two-way ANOVA and Tukey's test (α=0.05). After firing five and ten times, the hardness of VM-Z and C-Z increased significantly (p0.05). In the XRD analysis, zirconia had similar tetragonal (t)-monoclinic (m) phase transformations of Y-TZP after the different firing times. Clinically, multiple firings did not affect the microstructure of zirconia, but the structures of the two ceramics were affected.

  18. Occupational Health and Safety Issues in Ontario Sawmills and Veneer/Plywood Plants: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Dave K. Verma

    2010-01-01

    Full Text Available A pilot study was conducted within the Ontario sawmill and veneer/plywood manufacturing industry. Information was collected by postal questionnaire and observational walk-through surveys. Industrial hygiene walk-through surveys were conducted at 22 work sites, and measurements for wood dust, noise, and bioaerosol were taken. The aim of the study was to obtain data on the current status regarding health and safety characteristics and an estimate of wood dust, noise, and bioaerosol exposures. The occupational exposure to wood dust and noise are similar to what has been reported in this industry in Canada and elsewhere. Airborne wood dust concentration ranged between 0.001 mg/m3 and 4.87 mg/m3 as total dust and noise exposure ranged between 55 and 117 dB(A. The study indicates the need for a more comprehensive industry-wide study of wood dust, noise, and bioaersols.

  19. Minimally invasive restoration of a maxillary central incisor with a partial veneer.

    Science.gov (United States)

    Horvath, Sebastian; Schulz, Claus-Peter

    2012-01-01

    Minimally invasive treatment modalities allow for the preservation of sound tooth substance. However, by limiting the preparation to the extent of a defect, the transition between restoration and natural tooth may be moved to more visible areas. The materials available for the restoration of a limited defect in the anterior area are either resin composite materials or porcelain. A patient was presented who asked for the replacement of a discolored filling on the maxillary right central incisor. Tooth preparation was limited to the extent of the old filling, and a porcelain partial veneer restoration was fabricated. Despite the horizontal finish line in the middle of the clinical crown, a result could be achieved that was regarded as a success by the patient. This type of restoration proves to be a suitable alternative to direct composite restorations in the anterior area for the reconstruction of a limited defect, eg, due to a dental trauma.

  20. Ceramic materials for porcelain veneers: part II. Effect of material, shade, and thickness on translucency.

    Science.gov (United States)

    Barizon, Karine T L; Bergeron, Cathia; Vargas, Marcos A; Qian, Fang; Cobb, Deborah S; Gratton, David G; Geraldeli, Saulo

    2014-10-01

    Information regarding the differences in translucency among new ceramic systems is lacking. The purpose of this study was to compare the relative translucency of the different types of ceramic systems indicated for porcelain veneers and to evaluate the effect of shade and thickness on translucency. Disk specimens 13 mm in diameter and 0.7-mm thick were fabricated for the following 9 materials (n=5): VITA VM9, IPS Empress Esthetic, VITA PM9, Vitablocks Mark II, Kavo Everest G-Blank, IPS Empress CAD, IPS e.max CAD, IPS e.maxPress, and Lava Zirconia. VITA VM9 served as the positive control and Lava as the negative control. The disks were fabricated with the shade that corresponds to A1. For IPS e.maxPress, additional disks were made with different shades (BL2, BL4, A1, B1, O1, O2, V1, V2, V3), thickness (0.3 mm), and translucencies (high translucency, low translucency). Color coordinates (CIE L∗ a∗ b∗) were measured with a tristimulus colorimeter. The translucency parameter was calculated from the color difference of the material on a black versus a white background. One-way ANOVA, the post hoc Tukey honestly significant difference, and the Ryan-Einot-Gabriel-Welsch multiple range tests were used to analyze the data (α=.05). Statistically significant differences in the translucency parameter were found among porcelains (PPM9, Empress Esthetic>Empress CAD>Mark II, Everest, e.max CAD>e.max Press>Lava. Significant differences also were noted when different shades and thickness were compared (Pceramic systems designed for porcelain veneers present varying degrees of translucency. The thickness and shade of lithium disilicate ceramic affect its translucency. Shade affects translucency parameter less than thickness. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  1. Effect of resin shades on opacity of ceramic veneers and polymerization efficiency through ceramics.

    Science.gov (United States)

    Öztürk, Elif; Chiang, Yu-Chih; Coşgun, Erdal; Bolay, Şükran; Hickel, Reinhard; Ilie, Nicoleta

    2013-11-01

    The aim of this study was to assess the effect of different resin cement shades on the opacity and color difference of ceramics and to determine the polymerization efficiency of the resin cement at different shades after curing through ceramics. Two different ceramics (IPS e.max Press and IPS Empress(®)CAD, Ivoclar Vivadent) were used for this study. A light-cured veneer luting resin (Variolink Veneer, Ivoclar Vivadent) in four different shades of HV+1, HV+3, LV-1, and LV-3 was used for the colorimetric measurements. The color and spectral reflectance of the ceramics were measured according to the CIELab color scale relative to the standard illuminant D65 on a reflection spectrophotometer (ColorEye7000A, USA). Color differences (ΔE values) and the contrast ratios (CR) of the different groups of samples were calculated. In order to analyse the polymerization efficiency of the resin cements, the micromechanical properties of the resins were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). The results were analysed using one-way ANOVA and Tukey's HSD post hoc tests (SPSS 18.0). The one-way ANOVA test showed that the values of ΔE and CR of the different specimen groups were significantly different (p<0.05). Group 1 (20.7 ± 0.5) (IPS-CAD without resin cement) exhibited the highest and group 10 (14.8 ± 0.5) (e.max:HV+3) exhibited the lowest ΔE value. Significant differences in the micromechanical properties were identified among the tested resin cements in different shades (p<0.05). Resin cement shade is an important factor for the opacity of a restoration. Furthermore, the resin shade affects the micromechanical properties of the underlying resin cement. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. The effect of veneering on the marginal fit of CAD/CAM-generated, copy-milled, and cast metal copings.

    Science.gov (United States)

    Ates, Sabit Melih; Yesil Duymus, Zeynep; Caglar, Ipek; Hologlu, Bilal

    2017-11-01

    This in vitro study investigated the marginal fit of metal and zirconia copings before and after veneering on dies with shoulder/chamfer (s/c) finish lines. Using CAD/CAM, ten (n = 10) each s/c zirconia (NZ) copings and ten (n = 10) each s/c metal (MM) copings were generated. As controls, ten (n = 10) each s/c zirconia copings were copy-milled (ZZ) and ten (n = 10) each s/c metal copings were cast (CC). The vertical marginal discrepancy of the copings was measured at 20 predefined spots of the circular shoulder and chamfer finish lines in microns (μm) before and after a first and a second veneering firing using a stereomicroscope at ×40 magnification. Data were statistically analyzed, and the comparisons of CAD/CAM-milled (NZ, MM), copy-milled (ZZ), and cast (CC) copings before and after veneering were made at a significance level of p < 0.05. Gap width at s/c finish lines of ZZ was (91 ± 11/100 ± 28) and increased significantly (109 ± 21/141 ± 18) after the first firing (ZZ1). NZ showed significantly smaller gaps than ZZ (36 ± 6/46 ± 12) and (NZ1) after the first firing (61 ± 16/71 ± 29). Gap widths of CC groups (36 ± 8/25 ± 4) were not significantly different from NZ but were significantly lower after the (CC1) first veneering firing (40 ± 8/42 ± 7). MM copings showed gap values similar to NZ. Second firings did not significantly increase gaps in all groups except ZZ2 of chamfer finish line. Veneering increased the marginal gap width of copings. Within the limits of this in vitro study, aesthetic ceramic veneering of CAD/CAM-generated copings caused a statistically significant but tolerable loss of marginal fit precision.

  3. Category O for quantum groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Mazorchuk, Volodymyr

    2015-01-01

    We study the BGG-categories O_q associated to quantum groups. We prove that many properties of the ordinary BGG-category O for a semisimple complex Lie algebra carry over to the quantum case. Of particular interest is the case when q is a complex root of unity. Here we prove a tensor decomposition...... for simple modules, projective modules, and indecomposable tilting modules. Using the known Kazhdan–Lusztig conjectures for O and for finite-dimensional U_q-modules we are able to determine all irreducible characters as well as the characters of all indecomposable tilting modules in O_q . As a consequence......, we also recover the known result that the generic quantum case behaves like the classical category O....

  4. Hippocampal activation during episodic and semantic memory retrieval: comparing category production and category cued recall.

    Science.gov (United States)

    Ryan, Lee; Cox, Christine; Hayes, Scott M; Nadel, Lynn

    2008-01-01

    Whether or not the hippocampus participates in semantic memory retrieval has been the focus of much debate in the literature. However, few neuroimaging studies have directly compared hippocampal activation during semantic and episodic retrieval tasks that are well matched in all respects other than the source of the retrieved information. In Experiment 1, we compared hippocampal fMRI activation during a classic semantic memory task, category production, and an episodic version of the same task, category cued recall. Left hippocampal activation was observed in both episodic and semantic conditions, although other regions of the brain clearly distinguished the two tasks. Interestingly, participants reported using retrieval strategies during the semantic retrieval task that relied on autobiographical and spatial information; for example, visualizing themselves in their kitchen while producing items for the category kitchen utensils. In Experiment 2, we considered whether the use of these spatial and autobiographical retrieval strategies could have accounted for the hippocampal activation observed in Experiment 1. Categories were presented that elicited one of three retrieval strategy types, autobiographical and spatial, autobiographical and nonspatial, and neither autobiographical nor spatial. Once again, similar hippocampal activation was observed for all three category types, regardless of the inclusion of spatial or autobiographical content. We conclude that the distinction between semantic and episodic memory is more complex than classic memory models suggest.

  5. FINANCIAL CONTROL AS A CATEGORY

    Directory of Open Access Journals (Sweden)

    Andrey Yu. Volkov

    2014-01-01

    Full Text Available The article reveals the basics of “financial control” as a category. The main attention is concentrated on the “control” itself (asa term, multiplicity of interpretation of“financial control” term and its juristic-practical matching. The duality of financial control category is detected. The identity of terms “financial control” and “state financial control” is justified. The article also offers ways of development of financial control juristical regulation.

  6. The effect of core material, veneering porcelain, and fabrication technique on the biaxial flexural strength and weibull analysis of selected dental ceramics.

    Science.gov (United States)

    Lin, Wei-Shao; Ercoli, Carlo; Feng, Changyong; Morton, Dean

    2012-07-01

    The objective of this study was to compare the effect of veneering porcelain (monolithic or bilayer specimens) and core fabrication technique (heat-pressed or CAD/CAM) on the biaxial flexural strength and Weibull modulus of leucite-reinforced and lithium-disilicate glass ceramics. In addition, the effect of veneering technique (heat-pressed or powder/liquid layering) for zirconia ceramics on the biaxial flexural strength and Weibull modulus was studied. Five ceramic core materials (IPS Empress Esthetic, IPS Empress CAD, IPS e.max Press, IPS e.max CAD, IPS e.max ZirCAD) and three corresponding veneering porcelains (IPS Empress Esthetic Veneer, IPS e.max Ceram, IPS e.max ZirPress) were selected for this study. Each core material group contained three subgroups based on the core material thickness and the presence of corresponding veneering porcelain as follows: 1.5 mm core material only (subgroup 1.5C), 0.8 mm core material only (subgroup 0.8C), and 1.5 mm core/veneer group: 0.8 mm core with 0.7 mm corresponding veneering porcelain with a powder/liquid layering technique (subgroup 0.8C-0.7VL). The ZirCAD group had one additional 1.5 mm core/veneer subgroup with 0.7 mm heat-pressed veneering porcelain (subgroup 0.8C-0.7VP). The biaxial flexural strengths were compared for each subgroup (n = 10) according to ISO standard 6872:2008 with ANOVA and Tukey's post hoc multiple comparison test (p≤ 0.05). The reliability of strength was analyzed with the Weibull distribution. For all core materials, the 1.5 mm core/veneer subgroups (0.8C-0.7VL, 0.8C-0.7VP) had significantly lower mean biaxial flexural strengths (p Empress and e.max groups, regardless of core thickness and fabrication techniques. Comparing fabrication techniques, Empress Esthetic/CAD, e.max Press/CAD had similar biaxial flexural strength (p= 0.28 for Empress pair; p= 0.87 for e.max pair); however, e.max CAD/Press groups had significantly higher flexural strength (p Empress Esthetic/CAD groups. Monolithic core

  7. PRELIMINARY STUDY OF PLYWOOD PRODUCED WITH PARICÁ (Schizolobium amazonicum Huber ex Ducke VENEERS MODIFIED BY THERMO-MECHANICAL TREATMENT

    Directory of Open Access Journals (Sweden)

    Larissa Medeiros Arruda

    2011-05-01

    Full Text Available The objective of this preliminary research was to study the effects of thermo-mechanical modification in veneers of Paricá (Schizolobium amazonicum Huber ex Ducke to improve plywood hygroscopicity and mechanical properties. The amount of 24 veneers was used with the dimensions 25 x 25 cm, that were compressed under different times (5, 10 and 15 minutes at 150°C and pressure at 1 N.mm-2, constituting three treatments and one untreated. Plywood were bonded with resorcinol-formaldehyde, glue consumption of 360 g.m-2 at ambient temperature and pressure of 1 N.mm-2 for 10 hours. The samples were evaluated by colorimetric analysis and physical and mechanical properties. Colorimetric analysis showed that there was a darkening of the wood toward the increase of treatment time. The treatment was not efficient in reducing swelling, only reducing absorption of water. The mechanical properties were not significantly affected by the treatment.

  8. The Investigation on Feasibility of Oriented Strand Boards to Parquet Production from Mixed Residual Veneer Popular and Beech

    Directory of Open Access Journals (Sweden)

    Saeid Kamrani

    2013-06-01

    Full Text Available The objective of this study was to investigate of feasibility of using residual veneer (popular and beechto manufacture oriented strand board (OSB parquet. Percentage of mixed residual veneer popular to beech was 40%to 60% respectly. In this study press time (6, 8 and 10 min and press temperature (170º, 180ºwere selected as variables, other factors being kept constant. Results indicated that increase of press temperature had no significant effect on modules of rupture, modules of elasticity and hardness but had significant effect on internal bonding, water absorption and thickness swelling. However results indicated that increase of press time had significant effect on total physical and mechanical properties of boards.

  9. Rehabilitation of a patient with amelogenesis imperfecta using porcelain veneers and CAD/CAM polymer restorations: A clinical report.

    Science.gov (United States)

    Saeidi Pour, Reza; Edelhoff, Daniel; Prandtner, Otto; Liebermann, Anja

    2015-01-01

    The complete dental rehabilitation of patients with a vertical dimension loss (VDL) caused by structural enamel deficits associated with amelogenesis imperfecta (AI) represents a difficult challenge for restorative teams. Accurate analysis and treatment planning that includes esthetic and functional evaluations and adequate material selection are important prerequisites for successful results. Long-term provisional restorations play an important role in exploring and elucidating the patients' esthetic demands and functional needs. Restorative treatment options can vary from requiring only oral hygiene instructions to extensive dental restorations that include composite fillings, ceramic veneers, metal-ceramic, or all-ceramic crowns. This case report describes a full-mouth rehabilitation of a patient with amelogenesis imperfecta including the case planning, bite replacement, preparation, and restoration setting steps with an experimental CAD/CAM polymer and porcelain veneers.

  10. International Conference on Category Theory

    CERN Document Server

    Pedicchio, Maria; Rosolini, Guiseppe

    1991-01-01

    With one exception, these papers are original and fully refereed research articles on various applications of Category Theory to Algebraic Topology, Logic and Computer Science. The exception is an outstanding and lengthy survey paper by Joyal/Street (80 pp) on a growing subject: it gives an account of classical Tannaka duality in such a way as to be accessible to the general mathematical reader, and to provide a key for entry to more recent developments and quantum groups. No expertise in either representation theory or category theory is assumed. Topics such as the Fourier cotransform, Tannaka duality for homogeneous spaces, braided tensor categories, Yang-Baxter operators, Knot invariants and quantum groups are introduced and studies. From the Contents: P.J. Freyd: Algebraically complete categories.- J.M.E. Hyland: First steps in synthetic domain theory.- G. Janelidze, W. Tholen: How algebraic is the change-of-base functor?.- A. Joyal, R. Street: An introduction to Tannaka duality and quantum groups.- A. Jo...

  11. Learnable Classes of Categorial Grammars.

    Science.gov (United States)

    Kanazawa, Makoto

    Learnability theory is an attempt to illuminate the concept of learnability using a mathematical model of learning. Two models of learning of categorial grammars are examined here: the standard model, in which sentences presented to the learner are flat strings of words, and one in which sentences are presented in the form of functor-argument…

  12. Language universals without universal categories

    NARCIS (Netherlands)

    Croft, W.; van Lier, E.

    2012-01-01

    In this article, the authors present their views on an article by author Sandra Chung related to lexical categories. According to them, Chung's article critiques an analysis of word classes in Chamorro by author Donald M. Topping. They discuss the restatements made by Chung on Topping's criteria for

  13. Auditory and phonetic category formation

    NARCIS (Netherlands)

    Goudbeek, Martijn; Cutler, A.; Smits, R.; Swingley, D.; Cohen, Henri; Lefebvre, Claire

    2017-01-01

    Among infants' first steps in language acquisition is learning the relevant contrasts of the language-specific phonemic repertoire. This learning is viewed as the formation of categories in a multidimensional psychophysical space. Research in the visual modality has shown that for adults, some kinds

  14. Influence of zirconia framework thickness on residual stress profile in veneering ceramic: measurement by hole-drilling.

    Science.gov (United States)

    Mainjot, Amélie K; Schajer, Gary S; Vanheusden, Alain J; Sadoun, Michaël J

    2012-04-01

    Framework design is reported to influence chipping in zirconia-based restorations, which is an important cause of failure of such restorations. Residual stress profile in the veneering ceramic after the manufacturing process is an important predictive factor of the mechanical behavior of the material. The objective of this study is to investigate the influence of framework thickness on the stress profile measured in zirconia-based structures. The stress profile was measured with the hole-drilling method in bilayered disc samples of 20mm diameter with a 1.5 mm thick veneering ceramic layer. Six different framework thicknesses from 0.5 mm to 3 mm were studied. Two different cooling procedures were also investigated. Compressive stresses were observed in the surface, and tensile stresses in the depth of most of the samples. The slow cooling procedure was found to promote the development of interior tensile stresses, except for the sample with a 3mm thick framework. With the tempering procedure, samples with a 1.5 mm thick framework exhibited the most favorable stress profile, while thicker and thinner frameworks exhibited respectively in surface or interior tensile stresses. The measurements performed highlight the importance of framework thickness, which determine the nature of stresses and can explain clinical failures encountered, especially with thin frameworks. The adequate ratio between veneering ceramic and zirconia is hard to define, restricting the range of indications of zirconia-based restorations until a better understanding of such a delicate veneering process is achieved. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Marginal Vertical Discrepancies of Monolithic and Veneered Zirconia and Metal-Ceramic Three-Unit Posterior Fixed Dental Prostheses.

    Science.gov (United States)

    Lopez-Suarez, Carlos; Gonzalo, Esther; Pelaez, Jesus; Serrano, Benjamin; Suarez, Maria J

    2016-01-01

    The aim of this study was to investigate and compare the marginal fit of posterior fixed dental prostheses (FDPs) made of monolithic and veneered computer-aided design/computer-assisted manufacture (CAD/CAM) zirconia ceramic with metal-ceramic posterior FDPs. Thirty standardized steel dies were prepared to receive posterior three-unit FDPs. Specimens were randomly divided into three groups (n = 10): (1) metal-ceramic (control group), (2) veneered zirconia, and (3) monolithic zirconia. All FDPs were cemented using a glass-ionomer cement. The specimens were subjected to thermal cycling (5°C to 55°C). A scanning electron microscope (SEM) with a magnification of ×500 was used for measurements. The data were statistically analyzed using one-way analysis of variance and paired t test. Both zirconia groups showed similar vertical marginal discrepancies, and no significant differences (P = .661) in marginal adaptation were observed among the groups. No differences were observed in either group in marginal discrepancies between surfaces or abutments. Monolithic zirconia posterior FDPs exhibit similar vertical marginal discrepancies to veneered zirconia posterior FDPs. No influence of localization measurements was observed.

  16. Effect of autoclave induced low-temperature degradation on the adhesion energy between yttria-stabilized zirconia veneered with porcelain.

    Science.gov (United States)

    Li, Kai Chun; Waddell, J Neil; Prior, David J; Ting, Stephanie; Girvan, Liz; van Vuuren, Ludwig Jansen; Swain, Michael V

    2013-11-01

    To investigate the effect of autoclave induced low-temperature degradation on the adhesion energy between yttria-stabilized zirconia veneered with porcelain. The strain energy release rate using a four-point bending stable fracture test was evaluated for two different porcelains [leucite containing (VM9) and glass (Zirox) porcelain] veneered to zirconia. Prior to veneering the zirconia had been subjected to 0 (control), 1, 5, 10 and 20 autoclave cycles. The specimens were manufactured to a total bi-layer dimension of 30 mm × 8 mm × 3 mm. Subsequent scanning electron microscopy/energy dispersive spectrometry, electron backscatter diffraction and X-ray diffraction analysis were performed to identify the phase transformation and fracture behavior. The strain energy release rate for debonding of the VM9 specimens were significantly higher (pautoclave cycles lowered the strain energy release rate significantly (pautoclave cycles between 5 and 20. The monoclinic phase reverted back to tetragonal phase after undergoing conventional porcelain firing cycles. EBSD data showed significant changes of the grain size distribution between the control and autoclaved specimen (cycle 20). Increasing autoclave cycles only significantly decreased the adhesion of the VM9 layered specimens. In addition, a conventional porcelain firing schedule completely reverted the monoclinic phase back to tetragonal. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  17. Novel UV cured polymers for coating and recycling cellulosics, application to a unique paper / veneer from the waste banana tree

    International Nuclear Information System (INIS)

    Dennis, G.R.; Garnett, J.L.; Jarrett, K.J.

    2007-01-01

    Work involving UV curing and cure-grafting processes on material from the waste banana tree has been performed. Water compatible oligomers of unique structure and processing novel properties have been used in this treatment. The material from the waste banana tree has been obtained by a peeling process and can be treated either as a type of paper or as a modified timber veneer leading to two general lines of potential commercial products. The peeled product is coated with formulations containing the novel oligomers and UV cured. The advantages of using these unique water compatible oligomers in all general UV curing systems are discussed. The effect of including nanoparticle fillers in these coating formulations is considered. The effect of the presence of lignin in the banana ply paper on the curing process is examined by comparing the banana ply paper curing data with analogous results from a pure cellulose Whatman 41 paper. Two UV lamps have been used in these studies, a Fusion F-300 and a Con-Trol-Cure LED, the latter shown to be safer from body exposure considerations because it operates in a 385-405 nm wavelength band. A mechanism for the curing and cure-grafting process on banana ply paper/veneer has been proposed. The commercial potential of this process is discussed especially the economic advantages of using the banana ply paper/veneer which is not chemically pulped. (Author)

  18. Some properties of LVL composed of poplar and beech veneer and possibilities of their application for window frames

    Directory of Open Access Journals (Sweden)

    Zdravković Vladislav

    2017-01-01

    Full Text Available The subject of this paper was a research of physical and mechanical properties of LVL composed of peeled poplar veneers in core layers and only outer layers of beech peeled veneers, so as the examination of window frame glue joint strength produced of this material. LVL boards have been hot pressed in industrial conditions, using appropriate phenol formaldehyde (PP adhesive. Samples for corner window frame glue joint strength testing were glued with PVAc D4 class adhesive. Statistical analysis showed that there were significant differences both in moisture content and density of LVL boards regarding their thickness, while in the case of hardness this difference did not exist. Examinations of LVL glue line shear strength showed that both phenol formaldehyde (PP and PVAc D4 class adhesives fulfilled standard requirements. The results of corner window frame double tenon glue joint strength produced from combined poplar-beech veneer LVL indicated that such material could be used to produce window frame corner joint, strong enough to withstand the additional load, without an increase of the cross section.

  19. Comparison of Marginal and Internal Adaptation of Heat-Pressed and CAD/CAM Porcelain Laminate Veneers and a 2-Year Follow-Up.

    Science.gov (United States)

    Yuce, Mert; Ulusoy, Mubin; Turk, Ayse Gozde

    2017-12-22

    To compare marginal and internal adaptations of porcelain laminate veneers fabricated with heat-pressed and CAD/CAM techniques, and to evaluate the clinical performances 2 years after cementation. Thirty heat-pressed and 31 CAD/CAM porcelain laminate veneers were fabricated for 12 patients. Silicone replicas of each veneer were obtained. Replicas were sectioned into 4 parts to measure adaptations of the veneers. A stereomicroscope was used to measure from 3 locations of replicas for marginal, and 9 locations for internal adaptations at 40x magnification. Clinical evaluations were done at baseline and 6, 12, 18, and 24 months after cementation according to the modified United States Public Health Service (USPHS) criteria. Independent samples t-test compared the adaptation values between heat-pressed and CAD/CAM groups. Paired t-test was used to evaluate marginal and internal adaptations of each group. Differences between the modified USPHS criteria ratings of heat-pressed and CAD/CAM groups were determined by the Mann-Whitney U test. Kaplan-Meier analysis was used to analyze the survival ratings of the veneers (p CAD/CAM veneers were 295 and 314.98 μm, respectively, and there was no statistically significant difference (p = 0.541). Internal adaptation values of groups were not statistically different either (201.82 μm for heat pressed; 195.47 μm for CAD/CAM p = 0.734). When marginal and internal adaptation values were compared within groups, there were significant differences both for heat-pressed (p CAD/CAM (p CAD/CAM or heat-pressed, had no effect on the marginal and internal adaptation of porcelain laminate veneers. The results showed that both fabrication techniques performed well after 2 years of clinical performance. © 2017 by the American College of Prosthodontists.

  20. Grammatical Constructions as Relational Categories.

    Science.gov (United States)

    Goldwater, Micah B

    2017-07-01

    This paper argues that grammatical constructions, specifically argument structure constructions that determine the "who did what to whom" part of sentence meaning and how this meaning is expressed syntactically, can be considered a kind of relational category. That is, grammatical constructions are represented as the abstraction of the syntactic and semantic relations of the exemplar utterances that are expressed in that construction, and it enables the generation of novel exemplars. To support this argument, I review evidence that there are parallel behavioral patterns between how children learn relational categories generally and how they learn grammatical constructions specifically. Then, I discuss computational simulations of how grammatical constructions are abstracted from exemplar sentences using a domain-general relational cognitive architecture. Last, I review evidence from adult language processing that shows parallel behavioral patterns with expert behavior from other cognitive domains. After reviewing the evidence, I consider how to integrate this account with other theories of language development. Copyright © 2017 Cognitive Science Society, Inc.

  1. A Formal Calculus for Categories

    DEFF Research Database (Denmark)

    Cáccamo, Mario José

    This dissertation studies the logic underlying category theory. In particular we present a formal calculus for reasoning about universal properties. The aim is to systematise judgements about functoriality and naturality central to categorical reasoning. The calculus is based on a language which...... extends the typed lambda calculus with new binders to represent universal constructions. The types of the languages are interpreted as locally small categories and the expressions represent functors. The logic supports a syntactic treatment of universality and duality. Contravariance requires a definition...... of universality generous enough to deal with functors of mixed variance. Ends generalise limits to cover these kinds of functors and moreover provide the basis for a very convenient algebraic manipulation of expressions. The equational theory of the lambda calculus is extended with new rules for the definitions...

  2. Seismic Category I Structures Program

    International Nuclear Information System (INIS)

    Endebrock, E.G.; Dove, R.C.; Anderson, C.A.

    1984-01-01

    The Seismic Category I Structures Program currently being carried out at the Los Alamos National Laboratory is sponsored by the Mechanical/Structural Engineering Branch, Division of Engineering Technology of the Nuclear Regulatory Commission (NRC). This project is part of a program designed to increase confidence in the assessment of Category I nuclear power plant structural behavior beyond the design limit. The program involves the design, construction, and testing of heavily reinforced concrete models of auxiliary buildings, fuel-handling buildings, etc., but doe not include the reactor containment building. The overall goal of the program is to supply to the Nuclear Regulatory Commission experimental information and a validated procedure to establish the sensitivity of the dynamic response of these structures to earthquakes of magnitude beyond the design basis earthquake

  3. Different Categories of Business Risk

    Directory of Open Access Journals (Sweden)

    Simona-Valeria TOMA

    2011-11-01

    Full Text Available Every business organisation involves some element of risk. Unmitigated risks can result in lost opportunity, financial losses, loss of reputation, or loss of the right to operate in a jurisdiction. Like any other risk type, understanding business risks is quite important for every business to garner profits instead of facing losses. A business risk is a universal risk type; this means that every business in the world faces business risks. Therefore, it is imperative to understand the different categories of business risk in order to create the appropriate strategies. The aim of this paper is to describe the most important categories of business risks and to make sure that every type of risk receives equal treatment and consideration.

  4. Fracture and shear bond strength analyses of different dental veneering ceramics to zirconia

    International Nuclear Information System (INIS)

    Diniz, Alexandre C.; Nascimento, Rubens M.; Souza, Julio C.M.; Henriques, Bruno B.; Carreiro, Adriana F.P.

    2014-01-01

    The purpose of this work was to evaluate the interaction of different layering porcelains with zirconia via shear bond strength test and microscopy. Four different groups of dental veneering porcelains (VM9, Zirkonzanh, Ceramco, IPS) were fused onto forty zirconia-based cylindrical substrates (8 mm in diameter and 12 mm in height) (n = 10), according to the manufacturer's recommendations. Additionally, layered dental porcelain (D-sign, Ivoclar) was fired on ten Ni–Cr cylindrical substrates Shear bond strength tests of the veneering porcelain to zirconia or Ni–Cr were carried out at a crosshead speed of 0.5 mm/min. After the shear bond tests, the interfaces were analyzed by scanning electron microscopy (SEM). The fracture type exhibited by the different systems was also assessed. The results were statistically analyzed by ANOVA at a significant level of p < .05. The shear bond strength values of the porcelain-to-NiCr interfaces (25.3 ± 7.1 MPa) were significantly higher than those recorded for the following porcelain-to-zirconia systems: Zirkonzanh (18.8 ± 1 MPa), Ceramco (18.2 ± 4.7 MPa), and IPS (16 ± 4.5 MPa). However, no significant differences were found in the shear bond strength values between the porcelain-to-NiCr and porcelain (VM9)-to-zirconia (23.2 ± 5.1 MPa) groups (p > .05). All-ceramic interfaces revealed mixed failure type, cohesive in the porcelain and adhesive at the interface. This study demonstrated that all-ceramic systems do not attain yet the same bond strength standards equivalent to metal–ceramic systems. Therefore, despite the esthetic appeal of all-ceramic restorations, the adhesion between the porcelain and zirconia framework is still an issue considering the long term success of the restoration. - Highlights: • This study assessed the shear bond strength of different porcelains to zirconia. • The porcelain Vita VM9 showed a high shear bond strength to zirconia. • The fracture surface of all-ceramic systems revealed

  5. Fracture and shear bond strength analyses of different dental veneering ceramics to zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Diniz, Alexandre C. [School of Dentistry (DOD), Division of Prosthodontics, Universidade Federal do Rio Grande do Norte -UFRN, 59056-000, Natal (Brazil); Nascimento, Rubens M. [Materials Engineering Department, Universidade Federal do Rio Grande do Norte - UFRN, Natal (Brazil); Souza, Julio C.M. [Centre for Mechanics and Materials Technologies - CT2M, Department of Mechanical Engineering (DEM), Universidade do Minho, Campus Azurém, 4800-058, Guimarães (Portugal); Henriques, Bruno B. [Materials Engineering Department, Universidade Federal do Rio Grande do Norte - UFRN, Natal (Brazil); Centre for Mechanics and Materials Technologies - CT2M, Department of Mechanical Engineering (DEM), Universidade do Minho, Campus Azurém, 4800-058, Guimarães (Portugal); Carreiro, Adriana F.P., E-mail: adrianadafonte@hotmail.com [School of Dentistry (DOD), Division of Prosthodontics, Universidade Federal do Rio Grande do Norte -UFRN, 59056-000, Natal (Brazil)

    2014-05-01

    The purpose of this work was to evaluate the interaction of different layering porcelains with zirconia via shear bond strength test and microscopy. Four different groups of dental veneering porcelains (VM9, Zirkonzanh, Ceramco, IPS) were fused onto forty zirconia-based cylindrical substrates (8 mm in diameter and 12 mm in height) (n = 10), according to the manufacturer's recommendations. Additionally, layered dental porcelain (D-sign, Ivoclar) was fired on ten Ni–Cr cylindrical substrates Shear bond strength tests of the veneering porcelain to zirconia or Ni–Cr were carried out at a crosshead speed of 0.5 mm/min. After the shear bond tests, the interfaces were analyzed by scanning electron microscopy (SEM). The fracture type exhibited by the different systems was also assessed. The results were statistically analyzed by ANOVA at a significant level of p < .05. The shear bond strength values of the porcelain-to-NiCr interfaces (25.3 ± 7.1 MPa) were significantly higher than those recorded for the following porcelain-to-zirconia systems: Zirkonzanh (18.8 ± 1 MPa), Ceramco (18.2 ± 4.7 MPa), and IPS (16 ± 4.5 MPa). However, no significant differences were found in the shear bond strength values between the porcelain-to-NiCr and porcelain (VM9)-to-zirconia (23.2 ± 5.1 MPa) groups (p > .05). All-ceramic interfaces revealed mixed failure type, cohesive in the porcelain and adhesive at the interface. This study demonstrated that all-ceramic systems do not attain yet the same bond strength standards equivalent to metal–ceramic systems. Therefore, despite the esthetic appeal of all-ceramic restorations, the adhesion between the porcelain and zirconia framework is still an issue considering the long term success of the restoration. - Highlights: • This study assessed the shear bond strength of different porcelains to zirconia. • The porcelain Vita VM9 showed a high shear bond strength to zirconia. • The fracture surface of all-ceramic systems revealed

  6. A comparative study of progressive wear of four dental monolithic, veneered glass-ceramics.

    Science.gov (United States)

    Zhang, Zhenzhen; Yi, Yuanping; Wang, Xuesong; Guo, Jiawen; Li, Ding; He, Lin; Zhang, Shaofeng

    2017-10-01

    This study evaluated the wear performance and wear mechanisms of four dental glass-ceramics, based on the microstructure and mechanical properties in the progressive wear process. Bar (N = 40, n = 10) and disk (N = 32, n = 8) specimens were prepared from (A) lithium disilicate glass-ceramic (LD), (B) leucite reinforced glass-ceramic (LEU), (C) feldspathic glass-ceramic (FEL), and (D) fluorapatite glass-ceramic (FLU). The bar specimens were tested for three-point flexural strength, hardness, fracture toughness and elastic modulus. The disk specimens paired with steatite antagonists were tested in a pin-on-disk tribometer with 10N up to 1000,000 wear cycles. The wear analysis of glass-ceramics was performed using a 3D profilometer after every 200,000 wear cycles. Wear loss of steatite antagonists was calculated by measuring the weight and density using sensitive balance and Archimedes' method. Wear morphologies and microstructures were analyzed by scanning electron microscopy (SEM). The crystalline phase compositions were determined using X-ray diffraction (XRD). One-way analysis of variance (ANOVA) was used to analyze the data. Multiple pair-wise comparison of means was performed by Tukey's post-hoc test. LD showed the highest fracture toughness, flexural strength, elastic modulus and crystallinity, followed by LEU and FEL, and FLU showed the lowest. However, the hardness of LD was lower than all the other three types of ceramics. For steatite antagonists, LD produced the least wear loss of antagonist, followed by LEU and FEL, and FLU had the most wear loss. For glass-ceramic materials, LD exhibited similar wear loss as LEU, but more than FLU and FEL did. Moreover, fracture occurred on the wear surface of FLU. In the progressive wear process, veneering porcelains showed better wear resistance but fluorapatite veneering porcelains appeared fracture surface. Monolithic lithium disilicate glass-ceramics with higher mechanical properties showed more wear loss, however

  7. Virtue Ethics: The Misleading Category

    OpenAIRE

    Martha Nussbaum

    1998-01-01

    Virtue ethics is frequently considered to be a single category of ethical theory, and a rival to Kantianismand Utilitarianism. I argue that this approach is a mistake, because both Kantians and Utilitarians can, and do, have an interest in the virtues and the forrnation of character. But even if we focus on the group of ethical theorists who are most commonly called "virtue theorists" because they reject the guidance of both Kantianism and Utilitarianism, and derive inspiration from ancient G...

  8. Virtue Ethics: The Misleading Category

    OpenAIRE

    Nussbaum, Martha

    2013-01-01

    Virtue ethics is frequently considered to be a single category of ethical theory, and a rival to Kantianismand Utilitarianism. I argue that this approach is a mistake, because both Kantians and Utilitarians can, and do, have an interest in the virtues and the forrnation of character. But even if we focus on the group of ethical theorists who are most commonly called "virtue theorists" because they reject the guidance of both Kantianism and Utilitarianism, and derive inspiration from ancient G...

  9. 1999 who's who category index

    International Nuclear Information System (INIS)

    1999-01-01

    A classified index and alphabetical directory of Canadian corporate entities involved in the production, manufacturing, conversion, service, retail sales, research and development, transportation, insurance, legal and communications aspects of propane in Canada is provided. The alphabetical directory section provides the usual business information (name, postal address, phone, fax, e-mail and Internet addresses), names of principal officers, affiliations, products or services produced or marketed, and the category under which the company is listed in the classified index

  10. Pre-sintered Y-TZP sandblasting: effect on surface roughness, phase transformation, and Y-TZP/veneer bond strength

    Directory of Open Access Journals (Sweden)

    Carla Müller Ramos-Tonello

    Full Text Available Abstract Sandblasting is a common method to try to improve the Y-TZP/veneer bond strength of dental prostheses, however, it may put stress on zirconia surfaces and could accelerate the t→m phase transformation. Y-TZP sandblasting before sintering could be an alternative to improve surface roughness and bonding strength of veneering ceramic. Objectives. The aim of this study was to analyze the effect of Y-TZP pre-sintering sandblasting on surface roughness, phase transformation, and the Y-TZP/veneer shear bond strength. Material and Methods. The Y-TZP specimen surface underwent sandblasting with aluminum oxide (50 μm pre-sintering (Z-PRE and post-sintering (Z-POS. Z-CTR was not subjected to surface treatment. After ceramic veneer application, the specimens were subjected to shear bond testing. Surface roughness was analyzed by confocal microscopy. Y-TZP monoclinic and tetragonal phases were evaluated by micro-Raman spectroscopy. Shear bond strength and surface roughness data were analyzed by One-way ANOVA and Tukey tests (α=0.05. Differences in the wave numbers and the broadening bands of the Raman spectra were compared among groups. Results. Z-POS (9.73±5.36 MPa and Z-PRE (7.94±2.52 MPa showed the highest bond strength, significantly higher than that of Z-CTR (5.54±2.14 MPa. The Ra of Z-PRE (1.59±0.23 µm was much greater and significantly different from that of Z-CTR (0.29±0.05 µm and Z-POS (0.77±0.13 µm. All groups showed bands typical of the tetragonal (T and monoclinic (M phases. Y-TZP sandblasting before sintering resulted in rougher surfaces but did not increase the shear bond strength compared to post-sintering and increased surface defects. Conclusions. Surface treatment with Al3O2, regardless of the moment and application, improves the results of Y-TZP/veneer bonding and is not a specific cause of t→m transformation.

  11. Effect of stacking sequence on mechanical properties neem wood veneer plastic composites

    Science.gov (United States)

    Nagamadhu, M.; Kumar, G. C. Mohan; Jeyaraj, P.

    2018-04-01

    This study investigates the effect of wood veneer stacking sequence on mechanical properties of neem wood polymer composite (WPC) experimentally. Wood laminated samples were fabricated by conventional hand layup technique in a mold and cured under pressure at room temperature and then post cured at elevated temperature. Initially, the tensile, flexural, and impact test were conducted to understand the effect of weight fraction of fiber on mechanical properties. The mechanical properties have increased with the weight fraction of fiber. Moreover the stacking sequence of neem wood plays an important role. As it has a significant impact on the mechanical properties. The results indicated that 0°/0° WPC shows highest mechanical properties as compared to other sequences (90°/90°, 0°/90°, 45°/90°, 45°/45°). The Fourier Transform Infrared Spectroscopy (FTIR) Analysis were carried out to identify chemical compounds both in raw neem wood and neem wood epoxy composite. The microstructure raw/neat neem wood and the interfacial bonding characteristics of neem wood composite investigated using Scanning electron microscopy images.

  12. Effect of provisional cements on shear bond strength of porcelain laminate veneers.

    Science.gov (United States)

    Altintas, Subutay Han; Tak, Onjen; Secilmis, Asli; Usumez, Aslihan

    2011-08-01

    The purpose of this study was to evaluate the effect of three provisional cements and two cleaning techniques on the final bond strength of porcelain laminate veneers. The occlusal third of the crowns of forty molar teeth were sectioned and embedded in autopolymerizing acrylic resin. Dentin surfaces were polished and specimens were randomly divided into four groups (n=10). Provisional restorations were fabricated and two provisional restorations were cemented onto each tooth. Restorations were fixed with one of three different provisional cements: eugenol-free provisional cement (Cavex), calcium hydroxide (Dycal), and light-cured provisional cement (Tempond Clear). Provisional restorations were removed with either a dental explorer and air-water spray, or a cleaning bur (Opticlean). In the control group, provisional restorations were not used on the surfaces of specimens. IPS Empress 2 ceramic discs were luted with a dual-cured resin cement (Panavia F). Shear bond strength was measured using a universal testing machine. Data were statistically analyzed by ANOVA, Tukey's HSD and Dunnett tests. Surfaces were examined by scanning electronic microscopy. Significant differences were found between the control group and both the light-cured provisional cement groups and the eugenol-free provisional cement-cleaning bur group (Pprovisional cement showed the lowest bond strength values. Selection of the provisional cement is an important factor in the ultimate bond strength of the final restoration. Calcium hydroxide provisional cement and cleaning with a dental explorer are advisable.

  13. A category of its own?

    DEFF Research Database (Denmark)

    Elklit, Jørgen; Roberts, Nigel S.

    1996-01-01

    of these systems on the proportionality of the representation of political parties are, indeed, comparable. The four electoral systems were the basis of their countries' general elections during 1994. The results of these elections are used for analyses and discussions of the relative importance of the differences......At first sight, the electoral systems in Denmark, Germany, South Africa and Sweden may seem different and attaempt to categorize them together odd. All four, however, belong to the same category, which Arend Lijphart calls 'proportional representation two-tier districting systems', and the effects...

  14. Functional categories in comparative linguistics

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    , Roger M. 1979. Linguistic knowledge and cultural knowledge: some doubts and speculation. American Anthropologist 81-1, 14-36. Levinson, Stephen C. 1997. From outer to inner space: linguistic categories and non-linguistic thinking. In J. Nuyts and E. Pederson (eds.), Language and Conceptualization, 13......). Furthermore certain ‘ontological categories’ are language-specific (Malt 1995). For example, speakers of Kalam (New Guinea) do not classify the cassowary as a bird, because they believe it has a mythical kinship relation with humans (Bulmer 1967).       In this talk I will discuss the role of functional...

  15. 14 CFR 23.3 - Airplane categories.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Airplane categories. 23.3 Section 23.3... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES General § 23.3 Airplane categories. (a) The normal category is limited to airplanes that have a seating configuration, excluding pilot...

  16. Aspect as a Communicative Category

    DEFF Research Database (Denmark)

    Durst-Andersen, Per

    2018-01-01

    On the basis of internal evidence from primarily the use of imperfective forms and external evidence from primarily first language acquisition, it is argued that English, Russian, and French aspect differ from one another, because they go back to an obligatory choice among three possible communic......On the basis of internal evidence from primarily the use of imperfective forms and external evidence from primarily first language acquisition, it is argued that English, Russian, and French aspect differ from one another, because they go back to an obligatory choice among three possible...... communicative directions: should a grammatical category be grounded in the speaker's experience of a situation, in the situation referred to or in the hearer as information about the situation? The progressive vs. non-progressive distinction in English is acquired in the present tense of atelic (simplex) verbs...... to the meta-distinction between atelic (simplex) and telic (complex) verbs. It is second-person oriented. The specific order arrived at reflects the Peircean categories of Firstness, Secondness, and Thirdness and their predictions. This can account for the fact that the English and Russian types can be found...

  17. Standardization of radioactive waste categories

    International Nuclear Information System (INIS)

    1970-01-01

    A large amount of information about most aspects of radioactive waste management has been accumulated and made available to interested nations in recent years. The efficiency of this service has been somewhat hampered because the terminology used to describe the different types of radioactive waste has varied from country to country and indeed from installation to installation within a given country. This publication is the outcome of a panel meeting on Standardization of Radioactive Waste Categories. It presents a simple standard to be used as a common language between people working in the field of waste management at nuclear installations. The purpose of the standard is only to act as a practical tool for increasing efficiency in communicating, collecting and assessing technical and economical information in the common interest of all nations and the developing countries in particular. 20 refs, 1 fig., 3 tabs

  18. Influence of various bonding techniques on the fracture strength of thin CAD/CAM-fabricated occlusal glass-ceramic veneers.

    Science.gov (United States)

    Yazigi, Christine; Kern, Matthias; Chaar, Mohamed Sad

    2017-11-01

    To evaluate the efficiency of immediate dentin sealing and the effects of different bonding protocols on the fracture strength of CAD/CAM occlusal veneers bonded to exposed dentin. Ninety-six extracted maxillary premolars were initially divided into three main groups with 32 specimens each: without immediate dentin sealing, immediate dentin sealing/total etching and immediate dentin sealing/selective etching. Teeth were identically prepared in the dentin to receive occlusal veneers of 0.8mm thickness, milled from lithium disilicate ceramic blocks (IPS e.max CAD). Each main group was later subdivided, according to the pre-cementation surface etching protocol (total/selective), into two subgroups with 16 specimens each. All restorations were adhesively bonded using a resin cement (Variolink Esthetic). Half of the specimens of each subgroup were subjected to thermo-dynamic loading in a chewing simulator with 1,200,000 cycles at 10kg load. The other half and the surviving specimens were subjected to quasi-static loading until failure. Statistical analysis was performed using three-way ANOVA and Tukey's post-hoc tests. All specimens except one survived the artificial aging. A significantly higher fracture strength of restorations (p ≤ 0.001) was obtained when immediate dentin sealing was followed regardless of the etching method with values ranging from a minimum of 1122 ± 336N to a maximum of 1853 ± 333N. Neither the pre-cementation treatment nor the artificial aging had a statistical significant effect on the fracture strength. Immediate dentin sealing protocol is recommended whenever dentin is exposed during the preparation for thin glass-ceramic occlusal veneers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. SEM evaluation of human gingival fibroblasts growth onto CAD/CAM zirconia and veneering ceramic for zirconia

    Science.gov (United States)

    Zizzari, Vincenzo; Borelli, Bruna; De Colli, Marianna; Tumedei, Margherita; Di Iorio, Donato; Zara, Susi; Sorrentino, Roberto; Cataldi, Amelia; Gherlone, Enrico Felice; Zarone, Fernando; Tetè, Stefano

    2013-01-01

    Summary Aim To evaluate the growth of Human Gingival Fibroblasts (HGFs) cultured onto sample discs of CAD/CAM zirconia and veneering ceramic for zirconia by means of Scanning Electron Microscope (SEM) analysis at different experimental times. Methods A total of 26 experimental discs, divided into 2 groups, were used: Group A) CAD/CAM zirconia (3Y-TZP) discs (n=13); Group B) veneering ceramic for zirconia discs (n=13). HGFs were obtained from human gingival biopsies, isolated and placed in culture plates. Subsequently, cells were seeded on experimental discs at 7,5×103/cm2 concentration and cultured for a total of 7 days. Discs were processed for SEM observation at 3h, 24h, 72h and 7 days. Results In Group A, after 3h, HGFs were adherent to the surface and showed a flattened profile. The disc surface covered by HGFs resulted to be wider in Group A than in Group B samples. At SEM observation, after 24h and 72h, differences in cell attachment were slightly noticeable between the groups, with an evident flattening of HGFs on both surfaces. All differences between Group A and group B became less significant after 7 days of culture in vitro. Conclusions SEM analysis of HGFs showed differences in terms of cell adhesion and proliferation, especially in the early hours of culture. Results showed a better adhesion and cell growth in Group A than in Group B, especially up to 72h in vitro. Differences decreased after 7 days, probably because of the rougher surface of CAD/CAM zirconia, promoting better cell adhesion, compared to the smoother surface of veneering ceramic. PMID:24611089

  20. Influence of resin cement shade on the color and translucency of ceramic veneers

    Science.gov (United States)

    HERNANDES, Daiana Kelly Lopes; ARRAIS, Cesar Augusto Galvão; de LIMA, Erick; CESAR, Paulo Francisco; RODRIGUES, José Augusto

    2016-01-01

    ABSTRACT Objective This in vitro study evaluated the effect of two different shades of resin cement (RC- A1 and A3) layer on color change, translucency parameter (TP), and chroma of low (LT) and high (HT) translucent reinforced lithium disilicate ceramic laminates. Material and Methods One dual-cured RC (Variolink II, A1- and A3-shade, Ivoclar Vivadent) was applied to 1-mm thick ceramic discs to create thin RC films (100 µm thick) under the ceramics. The RC was exposed to light from a LED curing unit. Color change (ΔE) of ceramic discs was measured according to CIEL*a*b* system with a standard illuminant D65 in reflectance mode in a spectrophotometer, operating in the light range of 360-740 nm, equipped with an integrating sphere. The color difference between black (B) and white (W) background readings was used for TP analysis, while chroma was calculated by the formula C* ab=(a*2+b*2)½. ΔE of 3.3 was set as the threshold of clinically unacceptable. The results were evaluated by two-way ANOVA followed by Tukey's post hoc test. Results HT ceramics showed higher ΔE and higher TP than LT ceramics. A3-shade RC promoted higher ΔE than A1-shade cement, regardless of the ceramic translucency. No significant difference in TP was noted between ceramic discs with A1- and those with A3-shade cement. Ceramic with underlying RC showed lower TP than discs without RC. HT ceramics showed lower chroma than LT ceramics, regardless of the resin cement shade. The presence of A3-shade RC resulted in higher chroma than the presence of A1-shade RC. Conclusions Darker underlying RC layer promoted more pronounced changes in ceramic translucency, chroma, and shade of high translucent ceramic veneers. These differences may not be clinically differentiable. PMID:27556211

  1. Influence of polyurethane resin dies on the fit and adaptation of full veneer crowns.

    Science.gov (United States)

    Lillywhite, Graeme R R; Vohra, Fahim

    2015-01-01

    Polyurethane resin is a possible alternative to type IV dental stone for fabrication of indirect restorations however its dimensional accuracy is questionable. The aim was to investigate the dimensional accuracy of silica filled polyurethane resin die material by evaluating the marginal fit and adaptation of indirect gold castings. Experimental, in vitro study. Totally 40 copper plated replicas of a nickel chrome master die analogous to a veneer gold crown preparation were made and impressions recorded using polyvinylsiloxane material. Twenty impressions were poured in type IV dental stone (control group (Vel-mix, Kerr, UK) and the remaining (n = 20) in silica filled polyurethane die material (test group) (Alpha Die MF, CA, USA). Gold castings were fabricated for each die using standardized techniques. The castings were seated on their respective copper plated dies, embedded in resin and sectioned. The specimens were analyzed by measuring marginal opening and the area beneath the casting at a ×63 magnification and using image analysis software. Data were analyzed using a Student's t-test. No significant difference was observed between the experimental groups (P > 0.05). The mean marginal opening for type IV, dental stone and polyurethane resin, was 57 ± 22.6 μm and 63.47 ± 27.1 μm, respectively. Stone displayed a smaller area beneath the casting (31581 ± 16297 μm 2 ) as compared to polyurethane resin (35003 ± 23039 μm 2 ). The fit and adaptation of indirect gold castings made on polyurethane and type IV dental stone dies were comparable.

  2. Influence of resin cement shade on the color and translucency of ceramic veneers

    Directory of Open Access Journals (Sweden)

    Daiana Kelly Lopes HERNANDES

    Full Text Available ABSTRACT Objective This in vitro study evaluated the effect of two different shades of resin cement (RC- A1 and A3 layer on color change, translucency parameter (TP, and chroma of low (LT and high (HT translucent reinforced lithium disilicate ceramic laminates. Material and Methods One dual-cured RC (Variolink II, A1- and A3-shade, Ivoclar Vivadent was applied to 1-mm thick ceramic discs to create thin RC films (100 µm thick under the ceramics. The RC was exposed to light from a LED curing unit. Color change (ΔE of ceramic discs was measured according to CIEL*a*b* system with a standard illuminant D65 in reflectance mode in a spectrophotometer, operating in the light range of 360-740 nm, equipped with an integrating sphere. The color difference between black (B and white (W background readings was used for TP analysis, while chroma was calculated by the formula C*ab=(a*2+b*2½. ΔE of 3.3 was set as the threshold of clinically unacceptable. The results were evaluated by two-way ANOVA followed by Tukey's post hoc test. Results HT ceramics showed higher ΔE and higher TP than LT ceramics. A3-shade RC promoted higher ΔE than A1-shade cement, regardless of the ceramic translucency. No significant difference in TP was noted between ceramic discs with A1- and those with A3-shade cement. Ceramic with underlying RC showed lower TP than discs without RC. HT ceramics showed lower chroma than LT ceramics, regardless of the resin cement shade. The presence of A3-shade RC resulted in higher chroma than the presence of A1-shade RC. Conclusions Darker underlying RC layer promoted more pronounced changes in ceramic translucency, chroma, and shade of high translucent ceramic veneers. These differences may not be clinically differentiable.

  3. Influence of resin cement shade on the color and translucency of ceramic veneers.

    Science.gov (United States)

    Hernandes, Daiana Kelly Lopes; Arrais, Cesar Augusto Galvão; Lima, Erick de; Cesar, Paulo Francisco; Rodrigues, José Augusto

    2016-01-01

    This in vitro study evaluated the effect of two different shades of resin cement (RC- A1 and A3) layer on color change, translucency parameter (TP), and chroma of low (LT) and high (HT) translucent reinforced lithium disilicate ceramic laminates. One dual-cured RC (Variolink II, A1- and A3-shade, Ivoclar Vivadent) was applied to 1-mm thick ceramic discs to create thin RC films (100 µm thick) under the ceramics. The RC was exposed to light from a LED curing unit. Color change (ΔE) of ceramic discs was measured according to CIEL*a*b* system with a standard illuminant D65 in reflectance mode in a spectrophotometer, operating in the light range of 360-740 nm, equipped with an integrating sphere. The color difference between black (B) and white (W) background readings was used for TP analysis, while chroma was calculated by the formula C*ab=(a*2+b*2)½. ΔE of 3.3 was set as the threshold of clinically unacceptable. The results were evaluated by two-way ANOVA followed by Tukey's post hoc test. HT ceramics showed higher ΔE and higher TP than LT ceramics. A3-shade RC promoted higher ΔE than A1-shade cement, regardless of the ceramic translucency. No significant difference in TP was noted between ceramic discs with A1- and those with A3-shade cement. Ceramic with underlying RC showed lower TP than discs without RC. HT ceramics showed lower chroma than LT ceramics, regardless of the resin cement shade. The presence of A3-shade RC resulted in higher chroma than the presence of A1-shade RC. Darker underlying RC layer promoted more pronounced changes in ceramic translucency, chroma, and shade of high translucent ceramic veneers. These differences may not be clinically differentiable.

  4. Digital Smile Design concept delineates the final potential result of crown lengthening and porcelain veneers to correct a gummy smile.

    Science.gov (United States)

    Trushkowsky, Richard; Arias, David Montalvo; David, Steven

    Prior to initiating any treatment, it is necessary to visualize the desired outcomes. It then becomes possible to formulate the steps required to achieve this result. Digital Smile Design (DSD) utilizes patient input and information gathered through diagnostic procedures to create an esthetic treatment scheme. In the case presented here, the NYUCD Esthetic Evaluation Form, intraoral and extraoral photographs, mounted diagnostic casts, physical examination, and radiographs were the diagnostic modalities. The gathered information served as a starting point for a wax-up and intraoral mock-up. This case report demonstrates how the DSD served as a template for crown lengthening procedures and design of the final porcelain veneer restorations.

  5. Time-dependent fracture probability of bilayer, lithium-disilicate-based glass-ceramic molar crowns as a function of core/veneer thickness ratio and load orientation

    Science.gov (United States)

    Anusavice, Kenneth J.; Jadaan, Osama M.; Esquivel–Upshaw, Josephine

    2013-01-01

    Recent reports on bilayer ceramic crown prostheses suggest that fractures of the veneering ceramic represent the most common reason for prosthesis failure. Objective The aims of this study were to test the hypotheses that: (1) an increase in core ceramic/veneer ceramic thickness ratio for a crown thickness of 1.6 mm reduces the time-dependent fracture probability (Pf) of bilayer crowns with a lithium-disilicate-based glass-ceramic core, and (2) oblique loading, within the central fossa, increases Pf for 1.6-mm-thick crowns compared with vertical loading. Materials and methods Time-dependent fracture probabilities were calculated for 1.6-mm-thick, veneered lithium-disilicate-based glass-ceramic molar crowns as a function of core/veneer thickness ratio and load orientation in the central fossa area. Time-dependent fracture probability analyses were computed by CARES/Life software and finite element analysis, using dynamic fatigue strength data for monolithic discs of a lithium-disilicate glass-ceramic core (Empress 2), and ceramic veneer (Empress 2 Veneer Ceramic). Results Predicted fracture probabilities (Pf) for centrally-loaded 1,6-mm-thick bilayer crowns over periods of 1, 5, and 10 years are 1.2%, 2.7%, and 3.5%, respectively, for a core/veneer thickness ratio of 1.0 (0.8 mm/0.8 mm), and 2.5%, 5.1%, and 7.0%, respectively, for a core/veneer thickness ratio of 0.33 (0.4 mm/1.2 mm). Conclusion CARES/Life results support the proposed crown design and load orientation hypotheses. Significance The application of dynamic fatigue data, finite element stress analysis, and CARES/Life analysis represent an optimal approach to optimize fixed dental prosthesis designs produced from dental ceramics and to predict time-dependent fracture probabilities of ceramic-based fixed dental prostheses that can minimize the risk for clinical failures. PMID:24060349

  6. Time-dependent fracture probability of bilayer, lithium-disilicate-based, glass-ceramic, molar crowns as a function of core/veneer thickness ratio and load orientation.

    Science.gov (United States)

    Anusavice, Kenneth J; Jadaan, Osama M; Esquivel-Upshaw, Josephine F

    2013-11-01

    Recent reports on bilayer ceramic crown prostheses suggest that fractures of the veneering ceramic represent the most common reason for prosthesis failure. The aims of this study were to test the hypotheses that: (1) an increase in core ceramic/veneer ceramic thickness ratio for a crown thickness of 1.6mm reduces the time-dependent fracture probability (Pf) of bilayer crowns with a lithium-disilicate-based glass-ceramic core, and (2) oblique loading, within the central fossa, increases Pf for 1.6-mm-thick crowns compared with vertical loading. Time-dependent fracture probabilities were calculated for 1.6-mm-thick, veneered lithium-disilicate-based glass-ceramic molar crowns as a function of core/veneer thickness ratio and load orientation in the central fossa area. Time-dependent fracture probability analyses were computed by CARES/Life software and finite element analysis, using dynamic fatigue strength data for monolithic discs of a lithium-disilicate glass-ceramic core (Empress 2), and ceramic veneer (Empress 2 Veneer Ceramic). Predicted fracture probabilities (Pf) for centrally loaded 1.6-mm-thick bilayer crowns over periods of 1, 5, and 10 years are 1.2%, 2.7%, and 3.5%, respectively, for a core/veneer thickness ratio of 1.0 (0.8mm/0.8mm), and 2.5%, 5.1%, and 7.0%, respectively, for a core/veneer thickness ratio of 0.33 (0.4mm/1.2mm). CARES/Life results support the proposed crown design and load orientation hypotheses. The application of dynamic fatigue data, finite element stress analysis, and CARES/Life analysis represent an optimal approach to optimize fixed dental prosthesis designs produced from dental ceramics and to predict time-dependent fracture probabilities of ceramic-based fixed dental prostheses that can minimize the risk for clinical failures. Copyright © 2013 Academy of Dental Materials. All rights reserved.

  7. 40 CFR 98.190 - Definition of the source category.

    Science.gov (United States)

    2010-07-01

    .... (a) Lime manufacturing plants (LMPs) engage in the manufacture of a lime product (e.g., calcium oxide, high-calcium quicklime, calcium hydroxide, hydrated lime, dolomitic quicklime, dolomitic hydrate, or... kraft pulp mill, soda pulp mill, sulfite pulp mill, or only processes sludge containing calcium...

  8. 40 CFR 98.250 - Definition of source category.

    Science.gov (United States)

    2010-07-01

    ...; asphalt blowing operations; blowdown systems; storage tanks; process equipment components (compressors... plants (i.e., hydrogen plants that are owned or under the direct control of the refinery owner and...

  9. 40 CFR 98.270 - Definition of source category.

    Science.gov (United States)

    2010-07-01

    ... this section: (1) Chemical recovery furnaces at kraft and soda mills (including recovery furnaces that burn spent pulping liquor produced by both the kraft and semichemical process). (2) Chemical recovery... into paperboard products (e.g., containers), or operate coating and laminating processes. (b) The...

  10. Color categories and color appearance

    Science.gov (United States)

    Webster, Michael A.; Kay, Paul

    2011-01-01

    We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue–green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses. PMID:22176751

  11. The Micro-Category Account of Analogy

    Science.gov (United States)

    Green, Adam E.; Fugelsang, Jonathan A.; Kraemer, David J. M.; Dunbar, Kevin N.

    2008-01-01

    Here, we investigate how activation of mental representations of categories during analogical reasoning influences subsequent cognitive processing. Specifically, we present and test the central predictions of the "Micro-Category" account of analogy. This account emphasizes the role of categories in aligning terms for analogical mapping. In a…

  12. Individual differences in attention during category learning

    NARCIS (Netherlands)

    Lee, M.D.; Wetzels, R.

    2010-01-01

    A central idea in many successful models of category learning—including the Generalized Context Model (GCM)—is that people selectively attend to those dimensions of stimuli that are relevant for dividing them into categories. We use the GCM to re-examine some previously analyzed category learning

  13. EFFECTS OF PRESS PRESSURE ON GLUE LINE THICKNESS AND PROPERTIES OF LAMINATED VENEER LUMBER GLUED WITH MELAMINE UREA FORMALDEHYDE ADHESIVE

    Directory of Open Access Journals (Sweden)

    Ramazan Kurt,

    2012-07-01

    Full Text Available Laminated veneer lumbers (LVLs were manufactured from half-round sliced I-214 hybrid poplar clone veneers with MUF adhesives using press pressures ranging from 2.5 to 15 kg cm-2. The results showed that the press pressures affected the glue line thickness (GLT and the physical and mechanical properties of the LVLs. Higher specific gravity (SG and mechanical properties, but lower GLT were developed as a result of using higher press pressures. The optimum press pressure was found to be 10 kg cm-2 in relation to GLT, SG, and mechanical properties. Significant linear correlations were found between GLT and mechanical properties. GLT can be used to determine the quality of wood bonding and may become a valuable tool for this purpose. Reliable data on the optimum GLT and press pressures can be used to design safe wood bonding applications in all aspects of wood based composites, as well as wood constructions when appropriate techniques are adopted to measure the GLT.

  14. Bundles of C*-categories and duality

    OpenAIRE

    Vasselli, Ezio

    2005-01-01

    We introduce the notions of multiplier C*-category and continuous bundle of C*-categories, as the categorical analogues of the corresponding C*-algebraic notions. Every symmetric tensor C*-category with conjugates is a continuous bundle of C*-categories, with base space the spectrum of the C*-algebra associated with the identity object. We classify tensor C*-categories with fibre the dual of a compact Lie group in terms of suitable principal bundles. This also provides a classification for ce...

  15. Photostability and moisture uptake properties of wood veneers coated with a combination of thin sol-gel films and light stabilizers

    Science.gov (United States)

    Mandla A. Tshabalala; Ryan Libert; Christian M. Schaller

    2011-01-01

    In recent years, there has been increased interest in the use of inorganic UV blocking nanoparticles for photostabilization of wood surfaces. Photostability and moisture uptake properties of wood veneers coated with a combination of hybrid inorganic-organic thin sol-gel films and organic light stabilizers was investigated. The light stabilizers were applied by brushing...

  16. Effect of log soaking and the temperature of peeling on the properties of rotary-cut birch (Betula pendula Roth) veneer bonded with phenol-formaldehyde adhesive

    Science.gov (United States)

    Anti Rohumaa; Akio Yamamoto; Christopher G. Hunt; Charles R. Frihart; Mark Hughes; Jaan Kers

    2016-01-01

    Heating logs prior to peeling positively affects the surface properties of veneer as well as the wood-adhesive bond strength. However, the mechanism behind this increase in strength is not fully understood. The aim of the present study was to separate the influence of soaking temperature and peeling temperature on the physical surface properties and bonding quality....

  17. PRECEDENCE AS A PSYCHOLINGUISTIC CATEGORY

    Directory of Open Access Journals (Sweden)

    Panarina Nadezhda Sergeevna

    2015-06-01

    . In summary, any speech act assumes particular correlation and content of meaning components. Presence of culturological component in meaning structure represents specific nature of speech activity structural elements. Therefore, precedence is a psycholinguistic category, which must be considered taking into account structural features of a particular speech activity.

  18. A randomized controlled clinical trial of 3-unit posterior zirconia-ceramic fixed dental prostheses (FDP) with layered or pressed veneering ceramics: 3-year results.

    Science.gov (United States)

    Naenni, Nadja; Bindl, Andreas; Sax, Caroline; Hämmerle, Christoph; Sailer, Irena

    2015-11-01

    The aim of the present pilot study was to test whether or not posterior zirconia-ceramic fixed dental prostheses (FDPs) with pressed veneering ceramic exhibit less chipping than FDPs with layered veneering ceramics. Forty patients (13 female, 27 male; mean age 54 years (range 26.1-80.7 years) in need of one maxillary or mandibular three-unit FDP in the second premolar or molar region were recruited and treated at two separate centers at the University of Zurich according to the same study protocol. The frameworks were made out of zirconia using a CAD/CAM system (Cerec Sirona, Bensheim, Germany). The patients were randomly assigned to either the test group (zirconia frameworks veneered with pressed ceramic; IPS e.max ZirPress, Ivoclar Vivadent AG, Schaan, Liechtenstein; n=20) or the control group (layered veneering ceramic; IPS e.max Ceram, Ivoclar Vivadent AG, Schaan, Liechtenstein; n=20). All FDPs were adhesively cemented and evaluated at baseline (i.e., cementation), at 6 months and at 1 and 3 years of clinical service. The survival of the reconstruction was recorded. The technical outcome was assessed using modified United States Public Health Services (USPHS) criteria. The biologic parameters analyzed at abutment teeth and analogous non-restored teeth included probing pocket depth (PPD), plaque control record (PCR), bleeding on probing (BOP), and tooth vitality (CO2). Data was descriptively analyzed and survival was calculated using Kaplan-Meier statistics. 36 patients (25 female, 11 male; mean age 52.3 years) with 18 test and 18 control FDPs were examined after a mean follow-up of 36 months (95% CI: 32.6-39.1 months). Comparison of groups was done by Crosstabulation showing even distribution of the respective restored teeth amidst the groups. Survival rate was 100% for both test and control FDPs. Chipping of the veneering ceramic tended to occur more frequently in test (n=8; 40%) than in control (n=4; 20%) FDPs, albeit not significantly (p=0.3). No further

  19. Procedural-Based Category Learning in Patients with Parkinson's Disease: Impact of Category Number and Category Continuity

    Directory of Open Access Journals (Sweden)

    J. Vincent eFiloteo

    2014-02-01

    Full Text Available Previously we found that Parkinson's disease (PD patients are impaired in procedural-based category learning when category membership is defined by a nonlinear relationship between stimulus dimensions, but these same patients are normal when the rule is defined by a linear relationship (Filoteo et al., 2005; Maddox & Filoteo, 2001. We suggested that PD patients' impairment was due to a deficit in recruiting ‘striatal units' to represent complex nonlinear rules. In the present study, we further examined the nature of PD patients' procedural-based deficit in two experiments designed to examine the impact of (1 the number of categories, and (2 category discontinuity on learning. Results indicated that PD patients were impaired only under discontinuous category conditions but were normal when the number of categories was increased from two to four. The lack of impairment in the four-category condition suggests normal integrity of striatal medium spiny cells involved in procedural-based category learning. In contrast, and consistent with our previous observation of a nonlinear deficit, the finding that PD patients were impaired in the discontinuous condition suggests that these patients are impaired when they have to associate perceptually distinct exemplars with the same category. Theoretically, this deficit might be related to dysfunctional communication among medium spiny neurons within the striatum, particularly given that these are cholinergic neurons and a cholinergic deficiency could underlie some of PD patients’ cognitive impairment.

  20. Feature-Based versus Category-Based Induction with Uncertain Categories

    Science.gov (United States)

    Griffiths, Oren; Hayes, Brett K.; Newell, Ben R.

    2012-01-01

    Previous research has suggested that when feature inferences have to be made about an instance whose category membership is uncertain, feature-based inductive reasoning is used to the exclusion of category-based induction. These results contrast with the observation that people can and do use category-based induction when category membership is…

  1. Cultural categories of energy use

    International Nuclear Information System (INIS)

    Barnett, S.

    1983-06-01

    Energy use patterns and attitudes are tied to more general cultural patterns, not simply to an economic or engineering rationality. To illustrate this, sharply contrasting use patterns and attitudes toward nuclear energy, coal and alternative forms of energy will be compared for India and the United States. This comparison, focussing on different perceptions of risks associated with developing energy technologies, future energy requirements, environmental concerns, and conservation patterns, will be used to develop a more extensive discussion of the above energy sources in western Europe and South America. The talk will conclude with some conjectures about the implications of cultural differences and political environments for world energy development patterns in the proximate future. Likely cultural and political influences on the direction of energy use (efficiency, rates of adoption of new technology), and energy needs for industrialization and reindustrialization will be described for North America, western Europe, and selected LDC's

  2. Main Clinical Outcomes of Feldspathic Porcelain and Glass-Ceramic Laminate Veneers: A Systematic Review and Meta-Analysis of Survival and Complication Rates.

    Science.gov (United States)

    Morimoto, Susana; Albanesi, Rafael Borges; Sesma, Newton; Agra, Carlos Martins; Braga, Mariana Minatel

    2016-01-01

    The aim of this study was to perform a systematic review and meta-analysis based on clinical trials that evaluated the main outcomes of glass-ceramic and feldspathic porcelain laminate veneers. A systematic search was carried out in Cochrane and PubMed databases. From the selected studies, the survival rates for porcelain and glass-ceramic veneers were extracted, as were complication rates of clinical outcomes: debonding, fracture/chipping, secondary caries, endodontic problems, severe marginal discoloration, and influence of incisal coverage and enamel/dentin preparation. The Cochran Q test and the I(2) statistic were used to evaluate heterogeneity. Out of the 899 articles initially identified, 13 were included for analysis. Metaregression analysis showed that the types of ceramics and follow-up periods had no influence on failure rate. The estimated overall cumulative survival rate was 89% (95% CI: 84% to 94%) in a median follow-up period of 9 years. The estimated survival for glass-ceramic was 94% (95% CI: 87% to 100%), and for feldspathic porcelain veneers, 87% (95% CI: 82% to 93%). The meta-analysis showed rates for the following events: debonding: 2% (95% CI: 1% to 4%); fracture/chipping: 4% (95% CI: 3% to 6%); secondary caries: 1% (95% CI: 0% to 3%); severe marginal discoloration: 2% (95% CI: 1% to 10%); endodontic problems: 2% (95% CI: 1% to 3%); and incisal coverage odds ratio: 1.25 (95% CI: 0.33 to 4.73). It was not possible to perform meta-analysis of the influence of enamel/dentin preparation on failure rates. Glass-ceramic and porcelain laminate veneers have high survival rates. Fracture/ chipping was the most frequent complication, providing evidence that ceramic veneers are a safe treatment option that preserve tooth structure.

  3. Secondary overprinting of S-Se-Te signatures in the Earth's mantle: Implications for the Late Veneer

    Science.gov (United States)

    Koenig, S.; Luguet, A.; Lorand, J.; Pearson, D.

    2013-12-01

    Sulphur, Selenium and Tellurium are both chalcophile and highly siderophile elements (HSE) with near-chondritic ratios and absolute abundances in the terrestrial mantle that exceed those predicted by core-mantle differentiation[1]. These 'excess' HSE abundances have been attributed to addition of ca. 0.5% of chondrite-like material that hit the Earth in its accretionary stage between 4 to 3.8 billion years ago after core-mantle differentiation (Late Veneer[2]). Therefore, like other HSE, S, Se and Te are considered potential tracers for the composition of the Late Veneer, provided that their bulk silicate Earth abundances are properly constrained. In contrast to ca. 250 ppm S, Se and Te are ultra-trace elements in the terrestrial mantle. Like all HSE, they are furthermore controlled by base metal sulphides (BMS) and micrometric platinum group minerals (PGMs)[3]. This strong control exerted by the host mineralogy and petrology on the S-Se-Te systematics at both the micro-scale and the whole-rock scale makes detailed mineralogical and petrological studies of BMS and PGM a pre-requisite to fully understand and accurately interpret the whole-rock signatures. Here we combine in-situ sulphide data and detailed mineralogical observations with whole-rock S-Se-Te-HSE signatures of both lherzolites and harburgites from different geodynamic settings. We demonstrate that the near-chondritic Se and Te signature of 'fertile' mantle rocks (Se/Te ≈9×5) is not a primitive signature of the Earth's mantle, but rather reflects strong enrichment in metasomatic HSE host phases, which erased previous pristine signatures. Consequently, current attempts to identify a potential Late Veneer composition are seriously flawed because, neither refertilisation/metasomatism nor true melt depletion (e.g. harzburgitic residues) have been taken into account for the Primitive Upper Mantle composition estimate[4]. Our combined whole rock and in-situ sulphide data indicate a refertilisation trend

  4. Effect of core ceramic grinding on fracture behaviour of bilayered zirconia veneering ceramic systems under two loading schemes.

    Science.gov (United States)

    Jian, Yu-Tao; Tang, Tian-Yu; Swain, Michael V; Wang, Xiao-Dong; Zhao, Ke

    2016-12-01

    The aim of this in vitro study was to evaluate the effect of core ceramic grinding on the fracture behaviour of bilayered zirconia under two loading schemes. Interfacial surfaces of sandblasted zirconia disks (A) were ground with 80 (B), 120 (C) and 220 (D) grit diamond discs, respectively. Surface roughness and topographic analysis were performed using a confocal scanning laser microscope (CSLM) and a scanning electron microscopy (SEM). Relative monoclinic content was evaluated using X-ray diffraction analysis (XRD) then reevaluated after simulated veneer firing. Biaxial fracture strength (σ) and Weibull modulus (m) were calculated either with core in compression (subgroup Ac-Dc) or in tension (subgroup At-Dt). Facture surfaces were examined by SEM and energy dispersive X-ray spectroscopy (EDS). Maximum tensile stress at fracture was estimated by finite element analysis. Statistical data analysis was performed using Kruskal-Wallis and one-way ANOVA at a significance level of 0.05. As grit size of the diamond disc increased, zirconia surface roughness decreased (pgrinding. No difference in initial (p=0.519 for subgroups Ac-Dc) and final fracture strength (p=0.699 for subgroups Ac-Dc; p=0.328 for subgroups At-Dt) was found among the four groups for both loading schemes. While coarse grinding slightly increased final fracture strength reliability (m) for subgroups Ac-Dc. Two different modes of fracture were observed according to which material was on the bottom surface. Components of the liner porcelain remained on the zirconia surface after fracture for all groups. Technician grinding changed surface topography of zirconia ceramic material, but was not detrimental to the bilayered system strength after veneer application. Coarse grinding slightly improved the fracture strength reliability of the bilayered system tested with core in compression. It is recommended that veneering porcelain be applied directly after routine lab grinding of zirconia ceramic, and its

  5. TV MEDIA ANALYSIS FOR BANKING CATEGORY (2012)

    OpenAIRE

    Alexandra Elena POȘTOACĂ; Dorian – Laurențiu FLOREA

    2014-01-01

    This article represents a short overview of the media landscape for the banking category in Romania in 2012. Unlike the other categories (for example FMCG – fast moving consumer goods), the banking category is more complex because every bank can communicate for a wider range of products (credits, deposits, packages dedicated to students, pensioners and other types of banking products). In the first part of this paper, there will be presented some theoretical notions about media planning a...

  6. Misremembering emotion: Inductive category effects for complex emotional stimuli.

    Science.gov (United States)

    Corbin, Jonathan C; Crawford, L Elizabeth; Vavra, Dylan T

    2017-07-01

    Memories of objects are biased toward what is typical of the category to which they belong. Prior research on memory for emotional facial expressions has demonstrated a bias towards an emotional expression prototype (e.g., slightly happy faces are remembered as happier). We investigate an alternate source of bias in memory for emotional expressions - the central tendency bias. The central tendency bias skews reconstruction of a memory trace towards the center of the distribution for a particular attribute. This bias has been attributed to a Bayesian combination of an imprecise memory for a particular object with prior information about its category. Until now, studies examining the central tendency bias have focused on simple stimuli. We extend this work to socially relevant, complex, emotional facial expressions. We morphed facial expressions on a continuum from sad to happy. Different ranges of emotion were used in four experiments in which participants viewed individual expressions and, after a variable delay, reproduced each face by adjusting a morph to match it. Estimates were biased toward the center of the presented stimulus range, and the bias increased at longer memory delays, consistent with the Bayesian prediction that as trace memory loses precision, category knowledge is given more weight. The central tendency effect persisted within and across emotion categories (sad, neutral, and happy). This article expands the scope of work on inductive category effects to memory for complex, emotional stimuli.

  7. Biased Allocation of Faces to Social Categories

    NARCIS (Netherlands)

    Dotsch, R.; Wigboldus, D.H.J.; Knippenberg, A.F.M. van

    2011-01-01

    Three studies show that social categorization is biased at the level of category allocation. In all studies, participants categorized faces. In Studies 1 and 2, participants overallocated faces with criminal features-a stereotypical negative trait-to the stigmatized Moroccan category, especially if

  8. The ethnic category from a linguistic perspective

    Directory of Open Access Journals (Sweden)

    Răzvan Săftoiu

    2017-03-01

    Full Text Available In this paper, I put forward an analysis from a linguistic perspective of an ethnic category in Romania that is defined by at least two terms: gypsy and Romany. The concept of category refers to the members of a particular group that sets apart from other groups by a set of specific elements acknowledged at the level of a larger community. In interaction, individuals frequently use categories and the set of features that a certain category is characterized by, since it is easier to deal with sets of knowledge than with references for each individual separately. The analysis is based on a series of expressions and phrases, proverbs and jokes which were (or still are getting about in the Romanian space and which delineated, at the level of the collective mentality, the image of an ethnic category whose name (still oscillates between two terms. The texts were grouped depending on the different stereotypes associated with the ethnic category under discussion, by highlighting the pejorative connotations of the uses of the term gypsy in relation to the ethnic category Romany, a significance-free category that can be ‘filled up’ by elements that can sketch a positive image.

  9. Shape configuration and category-specificity

    DEFF Research Database (Denmark)

    Gerlach, Christian; Law, Ian; Paulson, Olaf B.

    2006-01-01

    a recent account of category-specificity and lends support to the notion that category-specific impairments can occur for both natural objects and artefacts following damage to pre-semantic stages in visual object recognition. The implications of the present findings are discussed in relation to theories...

  10. Conformal field theories and tensor categories. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Chengming [Nankai Univ., Tianjin (China). Chern Institute of Mathematics; Fuchs, Juergen [Karlstad Univ. (Sweden). Theoretical Physics; Huang, Yi-Zhi [Rutgers Univ., Piscataway, NJ (United States). Dept. of Mathematics; Kong, Liang [Tsinghua Univ., Beijing (China). Inst. for Advanced Study; Runkel, Ingo; Schweigert, Christoph (eds.) [Hamburg Univ. (Germany). Dept. of Mathematics

    2014-08-01

    First book devoted completely to the mathematics of conformal field theories, tensor categories and their applications. Contributors include both mathematicians and physicists. Some long expository articles are especially suitable for beginners. The present volume is a collection of seven papers that are either based on the talks presented at the workshop ''Conformal field theories and tensor categories'' held June 13 to June 17, 2011 at the Beijing International Center for Mathematical Research, Peking University, or are extensions of the material presented in the talks at the workshop. These papers present new developments beyond rational conformal field theories and modular tensor categories and new applications in mathematics and physics. The topics covered include tensor categories from representation categories of Hopf algebras, applications of conformal field theories and tensor categories to topological phases and gapped systems, logarithmic conformal field theories and the corresponding non-semisimple tensor categories, and new developments in the representation theory of vertex operator algebras. Some of the papers contain detailed introductory material that is helpful for graduate students and researchers looking for an introduction to these research directions. The papers also discuss exciting recent developments in the area of conformal field theories, tensor categories and their applications and will be extremely useful for researchers working in these areas.

  11. Color descriptors for object category recognition

    NARCIS (Netherlands)

    van de Sande, K.E.A.; Gevers, T.; Snoek, C.G.M.

    2008-01-01

    Category recognition is important to access visual information on the level of objects. A common approach is to compute image descriptors first and then to apply machine learning to achieve category recognition from annotated examples. As a consequence, the choice of image descriptors is of great

  12. Operadic categories and duoidal Deligne's conjecture

    Czech Academy of Sciences Publication Activity Database

    Batanin, M.; Markl, Martin

    2015-01-01

    Roč. 285, 5 November (2015), s. 1630-1687 ISSN 0001-8708 Institutional support: RVO:67985840 Keywords : operadic category * duoidal category * Deligne's conjecture Subject RIV: BA - General Mathematics Impact factor: 1.405, year: 2015 http://www.sciencedirect.com/science/article/pii/S0001870815002467

  13. Conformal field theories and tensor categories. Proceedings

    International Nuclear Information System (INIS)

    Bai, Chengming; Fuchs, Juergen; Huang, Yi-Zhi; Kong, Liang; Runkel, Ingo; Schweigert, Christoph

    2014-01-01

    First book devoted completely to the mathematics of conformal field theories, tensor categories and their applications. Contributors include both mathematicians and physicists. Some long expository articles are especially suitable for beginners. The present volume is a collection of seven papers that are either based on the talks presented at the workshop ''Conformal field theories and tensor categories'' held June 13 to June 17, 2011 at the Beijing International Center for Mathematical Research, Peking University, or are extensions of the material presented in the talks at the workshop. These papers present new developments beyond rational conformal field theories and modular tensor categories and new applications in mathematics and physics. The topics covered include tensor categories from representation categories of Hopf algebras, applications of conformal field theories and tensor categories to topological phases and gapped systems, logarithmic conformal field theories and the corresponding non-semisimple tensor categories, and new developments in the representation theory of vertex operator algebras. Some of the papers contain detailed introductory material that is helpful for graduate students and researchers looking for an introduction to these research directions. The papers also discuss exciting recent developments in the area of conformal field theories, tensor categories and their applications and will be extremely useful for researchers working in these areas.

  14. Connections between realcompactifications in various categories ...

    African Journals Online (AJOL)

    The author gives a detailed analysis of the relation between the theories of realcompactications and compactications in the category of ditopological texture spaces and in the categories of bitopological spaces and topological spaces. Keywords: Bitopology, texture, ditopology, Stone-Čech compactication, Hewitt real- ...

  15. Finding biomedical categories in Medline®

    Directory of Open Access Journals (Sweden)

    Yeganova Lana

    2012-10-01

    Full Text Available Abstract Background There are several humanly defined ontologies relevant to Medline. However, Medline is a fast growing collection of biomedical documents which creates difficulties in updating and expanding these humanly defined ontologies. Automatically identifying meaningful categories of entities in a large text corpus is useful for information extraction, construction of machine learning features, and development of semantic representations. In this paper we describe and compare two methods for automatically learning meaningful biomedical categories in Medline. The first approach is a simple statistical method that uses part-of-speech and frequency information to extract a list of frequent nouns from Medline. The second method implements an alignment-based technique to learn frequent generic patterns that indicate a hyponymy/hypernymy relationship between a pair of noun phrases. We then apply these patterns to Medline to collect frequent hypernyms as potential biomedical categories. Results We study and compare these two alternative sets of terms to identify semantic categories in Medline. We find that both approaches produce reasonable terms as potential categories. We also find that there is a significant agreement between the two sets of terms. The overlap between the two methods improves our confidence regarding categories predicted by these independent methods. Conclusions This study is an initial attempt to extract categories that are discussed in Medline. Rather than imposing external ontologies on Medline, our methods allow categories to emerge from the text.

  16. Appropriate Pupilness: Social Categories Intersecting in School

    Science.gov (United States)

    Kofoed, Jette

    2008-01-01

    The analytical focus in this article is on how social categories intersect in daily school life and how intersections intertwine with other empirically relevant categories such as normality, pupilness and (in)appropriatedness. The point of empirical departure is a daily ritual where teams for football are selected. The article opens up for a…

  17. Diagnostic Categories in Autobiographical Accounts of Illness.

    Science.gov (United States)

    Kelly, Michael P

    2015-01-01

    Working within frameworks drawn from the writings of Immanuel Kant, Alfred Schutz, and Kenneth Burke, this article examines the role that diagnostic categories play in autobiographical accounts of illness, with a special focus on chronic disease. Four lay diagnostic categories, each with different connections to formal medical diagnostic categories, serve as typifications to make sense of the way the lifeworld changes over the course of chronic illness. These diagnostic categories are used in conjunction with another set of typifications: lay epidemiologies, lay etiologies, lay prognostics, and lay therapeutics. Together these serve to construct and reconstruct the self at the center of the lifeworld. Embedded within the lay diagnostic categories are narratives of progression, regression, or stability, forms of typification derived from literary and storytelling genres. These narratives are developed by the self in autobiographical accounts of illness.

  18. Modular categories and 3-manifold invariants

    International Nuclear Information System (INIS)

    Tureav, V.G.

    1992-01-01

    The aim of this paper is to give a concise introduction to the theory of knot invariants and 3-manifold invariants which generalize the Jones polynomial and which may be considered as a mathematical version of the Witten invariants. Such a theory was introduced by N. Reshetikhin and the author on the ground of the theory of quantum groups. here we use more general algebraic objects, specifically, ribbon and modular categories. Such categories in particular arise as the categories of representations of quantum groups. The notion of modular category, interesting in itself, is closely related to the notion of modular tensor category in the sense of G. Moore and N. Seiberg. For simplicity we restrict ourselves in this paper to the case of closed 3-manifolds

  19. SUSTAIN: a network model of category learning.

    Science.gov (United States)

    Love, Bradley C; Medin, Douglas L; Gureckis, Todd M

    2004-04-01

    SUSTAIN (Supervised and Unsupervised STratified Adaptive Incremental Network) is a model of how humans learn categories from examples. SUSTAIN initially assumes a simple category structure. If simple solutions prove inadequate and SUSTAIN is confronted with a surprising event (e.g., it is told that a bat is a mammal instead of a bird), SUSTAIN recruits an additional cluster to represent the surprising event. Newly recruited clusters are available to explain future events and can themselves evolve into prototypes-attractors-rules. SUSTAIN's discovery of category substructure is affected not only by the structure of the world but by the nature of the learning task and the learner's goals. SUSTAIN successfully extends category learning models to studies of inference learning, unsupervised learning, category construction, and contexts in which identification learning is faster than classification learning.

  20. Methodological Aspects of Depreciation as an Economic Category

    OpenAIRE

    Sigidov, Yuriy I.; Rybyantseva, Maria S.; Adamenko, Alexandr A.; Yarushkina, Elena A.

    2016-01-01

    Depreciation is a complex economic category, the essence of which is manifested in the duality: this cost element, and its own source of reproduction of fixed assets and intangible assets. The depreciation laid relationship with asset and liability balance sheet; it touches on aspects such as formation costs, taxation issues, and reproductive process. That is why a methodological study of the depreciation essence, the allocation of the classification of bases, principles and functions seems u...

  1. Social Vision: Visual cues communicate categories to observers

    OpenAIRE

    Johnson, Kerri L

    2009-01-01

    This information ranges from appreciating category membership to evaluating more enduring traits and dispositions. These aspects of social perception appear to be highly automated, some would even call them obligatory, and they are heavily influenced by two sources of information: the face and the body. From minimal information such as brief exposure to the face or degraded images of dynamic body motion, social judgments are made with remarkable efficiency and, at times, surprising accuracy.

  2. Can height categories replace weight categories in striking martial arts competitions? A pilot study.

    Science.gov (United States)

    Dubnov-Raz, Gal; Mashiach-Arazi, Yael; Nouriel, Ariella; Raz, Raanan; Constantini, Naama W

    2015-09-29

    In most combat sports and martial arts, athletes compete within weight categories. Disordered eating behaviors and intentional pre-competition rapid weight loss are commonly seen in this population, attributed to weight categorization. We examined if height categories can be used as an alternative to weight categories for competition, in order to protect the health of athletes. Height and weight of 169 child and adolescent competitive karate athletes were measured. Participants were divided into eleven hypothetical weight categories of 5 kg increments, and eleven hypothetical height categories of 5 cm increments. We calculated the coefficient of variation of height and weight by each division method. We also calculated how many participants fit into corresponding categories of both height and weight, and how many would shift a category if divided by height. There was a high correlation between height and weight (r = 0.91, p<0.001). The mean range of heights seen within current weight categories was reduced by 83% when participants were divided by height. When allocating athletes by height categories, 74% of athletes would shift up or down one weight category at most, compared with the current categorization method. We conclude that dividing young karate athletes by height categories significantly reduced the range of heights of competitors within the category. Such categorization would not cause athletes to compete against much heavier opponents in most cases. Using height categories as a means to reduce eating disorders in combat sports should be further examined.

  3. Observation versus classification in supervised category learning.

    Science.gov (United States)

    Levering, Kimery R; Kurtz, Kenneth J

    2015-02-01

    The traditional supervised classification paradigm encourages learners to acquire only the knowledge needed to predict category membership (a discriminative approach). An alternative that aligns with important aspects of real-world concept formation is learning with a broader focus to acquire knowledge of the internal structure of each category (a generative approach). Our work addresses the impact of a particular component of the traditional classification task: the guess-and-correct cycle. We compare classification learning to a supervised observational learning task in which learners are shown labeled examples but make no classification response. The goals of this work sit at two levels: (1) testing for differences in the nature of the category representations that arise from two basic learning modes; and (2) evaluating the generative/discriminative continuum as a theoretical tool for understand learning modes and their outcomes. Specifically, we view the guess-and-correct cycle as consistent with a more discriminative approach and therefore expected it to lead to narrower category knowledge. Across two experiments, the observational mode led to greater sensitivity to distributional properties of features and correlations between features. We conclude that a relatively subtle procedural difference in supervised category learning substantially impacts what learners come to know about the categories. The results demonstrate the value of the generative/discriminative continuum as a tool for advancing the psychology of category learning and also provide a valuable constraint for formal models and associated theories.

  4. The impact of category structure and training methodology on learning and generalizing within-category representations.

    Science.gov (United States)

    Ell, Shawn W; Smith, David B; Peralta, Gabriela; Hélie, Sébastien

    2017-08-01

    When interacting with categories, representations focused on within-category relationships are often learned, but the conditions promoting within-category representations and their generalizability are unclear. We report the results of three experiments investigating the impact of category structure and training methodology on the learning and generalization of within-category representations (i.e., correlational structure). Participants were trained on either rule-based or information-integration structures using classification (Is the stimulus a member of Category A or Category B?), concept (e.g., Is the stimulus a member of Category A, Yes or No?), or inference (infer the missing component of the stimulus from a given category) and then tested on either an inference task (Experiments 1 and 2) or a classification task (Experiment 3). For the information-integration structure, within-category representations were consistently learned, could be generalized to novel stimuli, and could be generalized to support inference at test. For the rule-based structure, extended inference training resulted in generalization to novel stimuli (Experiment 2) and inference training resulted in generalization to classification (Experiment 3). These data help to clarify the conditions under which within-category representations can be learned. Moreover, these results make an important contribution in highlighting the impact of category structure and training methodology on the generalization of categorical knowledge.

  5. A Higher-Order Calculus for Categories

    DEFF Research Database (Denmark)

    Cáccamo, Mario José; Winskel, Glynn

    2001-01-01

    A calculus for a fragment of category theory is presented. The types in the language denote categories and the expressions functors. The judgements of the calculus systematise categorical arguments such as: an expression is functorial in its free variables; two expressions are naturally isomorphic...... in their free variables. There are special binders for limits and more general ends. The rules for limits and ends support an algebraic manipulation of universal constructions as opposed to a more traditional diagrammatic approach. Duality within the calculus and applications in proving continuity are discussed...... with examples. The calculus gives a basis for mechanising a theory of categories in a generic theorem prover like Isabelle....

  6. Kuranishi spaces as a 2-category

    OpenAIRE

    Joyce, Dominic

    2015-01-01

    This is a survey of the author's in-progress book arXiv:1409.6908. 'Kuranishi spaces' were introduced in the work of Fukaya, Oh, Ohta and Ono in symplectic geometry (see e.g. arXiv:1503.07631), as the geometric structure on moduli spaces of $J$-holomorphic curves. We propose a new definition of Kuranishi space, which has the nice property that they form a 2-category $\\bf Kur$. Thus the homotopy category Ho$({\\bf Kur})$ is an ordinary category of Kuranishi spaces. Any Fukaya-Oh-Ohta-Ono (FOOO)...

  7. Categories of space in music and lifestyles

    Directory of Open Access Journals (Sweden)

    Milenković Pavle

    2015-01-01

    Full Text Available This paper discusses the connection between categories of space in music, music production and lifestyles. The relations between the symbolic space of social connections and musical contents in the social space of various status interactions is complex and contradictory. Category of space in the music exists in four forms. Categories of space in the description of the experience of the musical works, as well as in the way of music production (spacing are the integral part of the special way of consumption of these works (home Hi-Fi, and represent the social status, ways of cultural consumption and habitus in general.

  8. Dose mapping in category I irradiators

    International Nuclear Information System (INIS)

    Mondal, Sandip; Shinde, S.H.; Mhatre, S.G.V.

    2012-01-01

    Category I irradiators such as Gamma Chambers and Blood Irradiators are compact self shielded, dry source storage gamma irradiators offering irradiation volume of few hundred cubic centimeters. In the present work, dose distribution profiles along the central vertical plane of the irradiation volume of Gamma Chamber 900 and Blood Irradiator 2000 were measured using Fricke, FBX, and alanine dosimeters. Measured dose distribution profiles in Gamma Chamber 900 differed from the typical generic dose distribution pattern whereas that in Blood Irradiator 2000 was in agreement with the typical pattern. All reagents used were of analytical reagent grade and were used without further purification. Preparation and dose estimations of Fricke and FBX were carried out as recommended. Alanine pellets were directly placed in precleaned polystyrene container having dimensions 6.5 mm o.d., 32 mm height and 3 mm wall thickness. For these dosimeters, dose measurements were made using e-scan Bruker BioSpin alanine dedicated ESR spectrometer. Specially designed perspex jigs were used during irradiation in Gamma Chamber 900 and Blood Irradiator 2000. These jigs provided the reproducible geometry during irradiation, Absorbance measurements were made using a spectrophotometer calibrated as per the recommended procedure. In Gamma Chamber 900, there is a dose distribution variation of about 34% from top to the center, 18% from center to the bottom, and 15% from center to the periphery. Such a dose distribution profile is largely deviating from the typical profile wherein 15% variation is observed from center to the periphery on all sides. Further investigation showed that there was a nonalignment in the source and sample chamber. However, in Blood Irradiator 2000, there is a dose distribution variation of about 20% from top to the center, 15% from center to the bottom, and 12% from center to the periphery. This pattern is very much similar to the typical profile. Hence it is recommended

  9. Shear Bond Strengths between Three Different Yttria-Stabilized Zirconia Dental Materials and Veneering Ceramic and Their Susceptibility to Autoclave Induced Low-Temperature Degradation

    Directory of Open Access Journals (Sweden)

    Manoti Sehgal

    2016-01-01

    Full Text Available A study was undertaken to evaluate the effect of artificial aging through steam and thermal treatment as influencing the shear bond strength between three different commercially available zirconia core materials, namely, Upcera, Ziecon, and Cercon, layered with VITA VM9 veneering ceramic using Universal Testing Machine. The mode of failure between zirconia and ceramic was further analyzed as adhesive, cohesive, or mixed using stereomicroscope. X-ray diffraction and SEM (scanning electron microscope analysis were done to estimate the phase transformation (m-phase fraction and surface grain size of zirconia particles, respectively. The purpose of this study was to simulate the clinical environment by artificial aging through steam and thermal treatment so as the clinical function and nature of the bond between zirconia and veneering material as in a clinical trial of 15 years could be evaluated.

  10. Words can slow down category learning.

    Science.gov (United States)

    Brojde, Chandra L; Porter, Chelsea; Colunga, Eliana

    2011-08-01

    Words have been shown to influence many cognitive tasks, including category learning. Most demonstrations of these effects have focused on instances in which words facilitate performance. One possibility is that words augment representations, predicting an across the-board benefit of words during category learning. We propose that words shift attention to dimensions that have been historically predictive in similar contexts. Under this account, there should be cases in which words are detrimental to performance. The results from two experiments show that words impair learning of object categories under some conditions. Experiment 1 shows that words hurt performance when learning to categorize by texture. Experiment 2 shows that words also hurt when learning to categorize by brightness, leading to selectively attending to shape when both shape and hue could be used to correctly categorize stimuli. We suggest that both the positive and negative effects of words have developmental origins in the history of word usage while learning categories. [corrected

  11. Category-specificity in visual object recognition

    DEFF Research Database (Denmark)

    Gerlach, Christian

    2009-01-01

    Are all categories of objects recognized in the same manner visually? Evidence from neuropsychology suggests they are not: some brain damaged patients are more impaired in recognizing natural objects than artefacts whereas others show the opposite impairment. Category-effects have also been...... demonstrated in neurologically intact subjects, but the findings are contradictory and there is no agreement as to why category-effects arise. This article presents a Pre-semantic Account of Category Effects (PACE) in visual object recognition. PACE assumes two processing stages: shape configuration (the...... binding of shape elements into elaborate shape descriptions) and selection (among competing representations in visual long-term memory), which are held to be differentially affected by the structural similarity between objects. Drawing on evidence from clinical studies, experimental studies...

  12. Visual object recognition and category-specificity

    DEFF Research Database (Denmark)

    Gerlach, Christian

    This thesis is based on seven published papers. The majority of the papers address two topics in visual object recognition: (i) category-effects at pre-semantic stages, and (ii) the integration of visual elements into elaborate shape descriptions corresponding to whole objects or large object parts...... (shape configuration). In the early writings these two topics were examined more or less independently. In later works, findings concerning category-effects and shape configuration merge into an integrated model, termed RACE, advanced to explain category-effects arising at pre-semantic stages in visual...... in visual long-term memory. In the thesis it is described how this simple model can account for a wide range of findings on category-specificity in both patients with brain damage and normal subjects. Finally, two hypotheses regarding the neural substrates of the model's components - and how activation...

  13. Uniform Reserve Training and Retirement Category Administration

    National Research Council Canada - National Science Library

    Kohner, D

    1997-01-01

    This Instruction implement policy as provided in DoD Directive 1215.6, assigns responsibilities and prescribes procedures that pertain to the designation and use of uniform Reserve component (RC) categories (RCCs...

  14. Topoi the categorial analysis of logic

    CERN Document Server

    Goldblatt, Robert

    2013-01-01

    A classic exposition of a branch of mathematical logic that uses category theory, this text is suitable for advanced undergraduates and graduate students and accessible to both philosophically and mathematically oriented readers.

  15. Comparing two K-category assignments by a K-category correlation coefficient

    DEFF Research Database (Denmark)

    Gorodkin, Jan

    2004-01-01

    Predicted assignments of biological sequences are often evaluated by Matthews correlation coefficient. However, Matthews correlation coefficient applies only to cases where the assignments belong to two categories, and cases with more than two categories are often artificially forced into two...... categories by considering what belongs and what does not belong to one of the categories, leading to the loss of information. Here, an extended correlation coefficient that applies to K-categories is proposed, and this measure is shown to be highly applicable for evaluating prediction of RNA secondary...

  16. Influence of a thin veneer of low-hydraulic-conductivity sediment on modelled exchange between river water and groundwater in response to induced infiltration

    Science.gov (United States)

    Rosenberry, Donald O.; Healy, Richard W.

    2012-01-01

    A thin layer of fine-grained sediment commonly is deposited at the sediment–water interface of streams and rivers during low-flow conditions, and may hinder exchange at the sediment–water interface similar to that observed at many riverbank-filtration (RBF) sites. Results from a numerical groundwater-flow model indicate that a low-permeability veneer reduces the contribution of river water to a pumping well in a riparian aquifer to various degrees, depending on simulated hydraulic gradients, hydrogeological properties, and pumping conditions. Seepage of river water is reduced by 5–10% when a 2-cm thick, low-permeability veneer is present on the bed surface. Increasing thickness of the low-permeability layer to 0·1 m has little effect on distribution of seepage or percentage contribution from the river to the pumping well. A three-orders-of-magnitude reduction in hydraulic conductivity of the veneer is required to reduce seepage from the river to the extent typically associated with clogging at RBF sites. This degree of reduction is much larger than field-measured values that were on the order of a factor of 20–25. Over 90% of seepage occurs within 12 m of the shoreline closest to the pumping well for most simulations. Virtually no seepage occurs through the thalweg near the shoreline opposite the pumping well, although no low-permeability sediment was simulated for the thalweg. These results are relevant to natural settings that favour formation of a substantial, low-permeability sediment veneer, as well as central-pivot irrigation systems, and municipal water supplies where river seepage is induced via pumping wells

  17. Mixed quantum states in higher categories

    Directory of Open Access Journals (Sweden)

    Chris Heunen

    2014-12-01

    Full Text Available There are two ways to describe the interaction between classical and quantum information categorically: one based on completely positive maps between Frobenius algebras, the other using symmetric monoidal 2-categories. This paper makes a first step towards combining the two. The integrated approach allows a unified description of quantum teleportation and classical encryption in a single 2-category, as well as a universal security proof applicable simultaneously to both scenarios.

  18. Derivation of plutonium-239 materials disposition categories

    International Nuclear Information System (INIS)

    Brough, W.G.

    1995-01-01

    At this time, the Office of Fissile Materials Disposition within the DOE, is assessing alternatives for the disposition of excess fissile materials. To facilitate the assessment, the Plutonium-Bearing Materials Feed Report for the DOE Fissile Materials Disposition Program Alternatives report was written. The development of the material categories and the derivation of the inventory quantities associated with those categories is documented in this report

  19. Monoidal categories and topological field theory

    CERN Document Server

    Turaev, Vladimir

    2017-01-01

    This monograph is devoted to monoidal categories and their connections with 3-dimensional topological field theories. Starting with basic definitions, it proceeds to the forefront of current research. Part 1 introduces monoidal categories and several of their classes, including rigid, pivotal, spherical, fusion, braided, and modular categories. It then presents deep theorems of Müger on the center of a pivotal fusion category. These theorems are proved in Part 2 using the theory of Hopf monads. In Part 3 the authors define the notion of a topological quantum field theory (TQFT) and construct a Turaev-Viro-type 3-dimensional state sum TQFT from a spherical fusion category. Lastly, in Part 4 this construction is extended to 3-manifolds with colored ribbon graphs, yielding a so-called graph TQFT (and, consequently, a 3-2-1 extended TQFT). The authors then prove the main result of the monograph: the state sum graph TQFT derived from any spherical fusion category is isomorphic to the Reshetikhin-Turaev surgery gr...

  20. [Effect of repeated sintering and variations in thickness on the color and microstructure of dental lithium disilicate-based glass ceramic veneers].

    Science.gov (United States)

    Cui, Huang; Jia, Yu; Shaofeng, Meng; Biyun, Gao

    2017-08-01

    Objective The aim of this study is to evaluate the effect of repeated sintering and variation in thickness on the color and microstructure of dental lithium disilicate-based glass ceramic veneers. Methods A total of 24 computer aided design and computer aided manufacturing (CAD/CAM) veneers was fabricated using the IPS e.max-CAD LS2 and then randomly divided into four groups (S0, S1, S2, S3; n=6). Each group was sintered 0, 1, 2, 3 times individually according to the manufacturer's recommendation. The color parameters (L, C, H, a, b values) of all the specimens were measured by a Vita easyshade dental colorimeter. The results were statistically analyzed using the SAS 9.1.3 software for MANOVA and LSD. Subsequently, the microstructures of the intersecting surfaces of the specimens were observed by scanning electron microscopy (SEM). Results After repeated sintering, the L value significantly decreased (P<0.05). For the C and b values, statistical differences were observed among the groups except between S2 and S3. SEM results showed that the interlocking microstructures of rod-shaped Li₂Si₂O₅ crystals became more compact when the number of sintering times was increased. Conclusion Repeated sintering exhibited significant influence on the color of the IPS e.max-CAD LS2 veneers.

  1. Evaluation of the color durability of acrylic resin veneer materials after immersion in common beverages at different time intervals: A spectrophotometric study.

    Science.gov (United States)

    Kohli, Shivani; Bhatia, Shekhar

    2015-01-01

    Proper function, esthetics, and cost are the prime factors to be considered while selecting bridge veneering materials. The purpose of the study is to evaluate color durability of acrylic veneer materials after immersion in common beverages at different time intervals. Spectrophotometer was used for taking color measurements based on the transmission of light through the specimens made of the selected materials which were Tooth moulding powder (DPI) and Acrylux (Ruthinium). Thirty specimens of standardized dimensions were prepared from each material. The specimens were divided into three groups of 10 each. One group of each material was immersed in tea (TajMahal) and another group of each material in cola (Pepsi) as the staining solutions. The remaining group of 10 from each material served as control and was stored in distilled water. Color measurements were obtained pre-immersion, and after 1, 15, and 30 days of immersion. Tooth moulding powder displayed better color durability than Acrylux over the 1 month immersion period in both staining solutions. Tea resulted in more discoloration compared to cola (Pepsi). The difference in the color durability of Acrylux and Tooth moulding powder may be attributed to the differences in the composition of tested resin veneering materials, i.e. their polar properties, which contribute to the absorption of staining solution, and the different brands and the strengths of the solutions.

  2. Evaluation of the color durability of acrylic resin veneer materials after immersion in common beverages at different time intervals: A spectrophotometric study

    Directory of Open Access Journals (Sweden)

    Shivani Kohli

    2015-06-01

    Full Text Available Background: Proper function, esthetics, and cost are the prime factors to be considered while selecting bridge veneering materials. The purpose of the study is to evaluate color durability of acrylic veneer materials after immersion in common beverages at different time intervals. Methods: Spectrophotometer was used for taking color measurements based on the transmission of light through the specimens made of the selected materials which were Tooth moulding powder (DPI and Acrylux (Ruthinium. Thirty specimens of standardized dimensions were prepared from each material. The specimens were divided into three groups of 10 each. One group of each material was immersed in tea (TajMahal and another group of each material in cola (Pepsi as the staining solutions. The remaining group of 10 from each material served as control and was stored in distilled water. Color measurements were obtained pre-immersion, and after 1, 15, and 30 days of immersion. Results: Tooth moulding powder displayed better color durability than Acrylux over the 1 month immersion period in both staining solutions. Tea resulted in more discoloration compared to cola (Pepsi. Conclusion: The difference in the color durability of Acrylux and Tooth moulding powder may be attributed to the differences in the composition of tested resin veneering materials, i.e. their polar properties, which contribute to the absorption of staining solution, and the different brands and the strengths of the solutions.

  3. Effect of bleaching and repolishing procedures on coffee and tea stain removal from three anterior composite veneering materials.

    Science.gov (United States)

    Türkün, L Sebnem; Türkün, Murat

    2004-01-01

    Discolored teeth can be treated with resin veneers, but their color changes when confronted with staining solutions. Polishing procedures can provide a remedy for highly stained composites, but they tend to remove some materials as well. However, bleaching procedures are an effective, nondestructive method for solving the problem. The aim of this study was to compare the color change of three veneer composites exposed to staining solutions and to evaluate the effectiveness of a 15% hydrogen peroxide bleaching agent and three polishing systems to remove the stain. Forty-five disks (12 x 2 mm) each of Clearfil ST (Kuraray Co. Ltd., Osaka, Japan), Esthet-X (Dentsply/Caulk, Milford DE, USA), and Filtek A110 (3M ESPE, St. Paul, MN, USA) were prepared. The specimens were polished with Sof-Lex (3M ESPE), Enhance (Dentsply/Caulk), or PoGo (Dentsply/Caulk). Five specimens for each material-polishing system combination were immersed in coffee (Nescafe Classic, Nestle SA, Vevey, Switzerland) or tea (Earl Grey, Lipton, Blackfriars-London, England) for 7 days. The remaining disks were stored in water. Color measurements were made with a spectrophotometer (X-Rite Seroice SP78, Loaner, Köln, Germany) at baseline; after 1, 3, 5, and 7 days; and after bleaching and repolishing. After 1 week, one side of the specimens was bleached with Illuminé-office (Dentsply De Trey GmbH, Konstanz, Germany) for 1 hour, and the other side was repolished for 30 seconds. All comparisons of color change for the polishing systems, times, and staining solutions were subjected to repeated measurements of analysis of variance. Paired t-test was used to examine whether significant color differences (deltaE*) occurred during immersion at the specified time intervals (p < or = .05). Filtek A110 was the least stained resin composite. Its color remained under a deltaE* value of 2 during the study. Clearfil ST exhibited the most color change after 1 week. All specimens polished with Enhance showed less

  4. 40 CFR 427.34 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Paper (Starch Binder) Subcategory § 427.34 Pretreatment standards for existing sources. Any existing source subject to...

  5. 40 CFR 427.44 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Paper (Elastomeric Binder) Subcategory § 427.44 Pretreatment standards for existing sources. Any existing source subject to...

  6. 40 CFR 417.84 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Soaps Subcategory § 417.84 Pretreatment standards for existing sources. Any existing source...

  7. Energy information data base: energy categories

    International Nuclear Information System (INIS)

    1980-03-01

    Citations entered into DOE's computerized bibliographic information system are assigned six-digit subject category numbers to group information broadly for storage, retrieval, and manipulation. These numbers are used in the preparation of printed documents, such as bibliographies and abstract journals, to arrange the citations and as searching aids in the on-line system, DOE/RECON. This document has been prepared for use by those individuals responsible for the assignment of category numbers to documents being entered into the Technical Information Center (TIC) system, those individuals and organizations processing magnetic tape copies of the files, those individuals doing on-line searching for information in TIC-created files, and others who, having no access to RECON, need printed copy. The six-digit numbers assigned to documents are listed, along with the category names and text to define the scope of interest. Asterisks highlight those categories added or changed since the previous printing, and a subject index further details the subject content of each category

  8. When does fading enhance perceptual category learning?

    Science.gov (United States)

    Pashler, Harold; Mozer, Michael C

    2013-07-01

    Training that uses exaggerated versions of a stimulus discrimination (fading) has sometimes been found to enhance category learning, mostly in studies involving animals and impaired populations. However, little is known about whether and when fading facilitates learning for typical individuals. This issue was explored in 7 experiments. In Experiments 1 and 2, observers discriminated stimuli based on a single sensory continuum (time duration and line length, respectively). Adaptive fading dramatically improved performance in training (unsurprisingly) but did not enhance learning as assessed in a final test. The same was true for nonadaptive linear fading (Experiment 3). However, when variation in length (predicting category membership) was embedded among other (category-irrelevant) variation, fading dramatically enhanced not only performance in training but also learning as assessed in a final test (Experiments 4 and 5). Fading also helped learners to acquire a color saturation discrimination amid category-irrelevant variation in hue and brightness, although this learning proved transitory after feedback was withdrawn (Experiment 7). Theoretical implications are discussed, and we argue that fading should have practical utility in naturalistic category learning tasks, which involve extremely high dimensional stimuli and many irrelevant dimensions. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  9. TV MEDIA ANALYSIS FOR BANKING CATEGORY (2012

    Directory of Open Access Journals (Sweden)

    Alexandra Elena POȘTOACĂ

    2014-04-01

    Full Text Available This article represents a short overview of the media landscape for the banking category in Romania in 2012. Unlike the other categories (for example FMCG – fast moving consumer goods, the banking category is more complex because every bank can communicate for a wider range of products (credits, deposits, packages dedicated to students, pensioners and other types of banking products. In the first part of this paper, there will be presented some theoretical notions about media planning and media analyses in order for the lecturer to easily go through the second part of the article. The second part of the paper will only refer to TV analyses. This media channel owns the highest budget share in our category, and also in the media mix of every important player, active in the Romanian market. The analyses will show which bank communicated most effectively, which is the most important spender on TV, what banking products had the largest budget allocated, which is the pattern for this category when it comes to allocating audience points for each day interval and so on. The starting point of this analyses is based on the secondary data obtained from InfoSys+ which is the world’s leading TV analyses software, used in more than 29 countries by 8000+ users.

  10. Grammatical category dissociation in multilingual aphasia.

    Science.gov (United States)

    Faroqi-Shah, Yasmeen; Waked, Arifi N

    2010-03-01

    Word retrieval deficits for specific grammatical categories, such as verbs versus nouns, occur as a consequence of brain damage. Such deficits are informative about the nature of lexical organization in the human brain. This study examined retrieval of grammatical categories across three languages in a trilingual person with aphasia who spoke Arabic, French, and English. In order to delineate the nature of word production difficulty, comprehension was tested, and a variety of concomitant lexical-semantic variables were analysed. The patient demonstrated a consistent noun-verb dissociation in picture naming and narrative speech, with severely impaired production of verbs across all three languages. The cross-linguistically similar noun-verb dissociation, coupled with little evidence of semantic impairment, suggests that (a) the patient has a true "nonsemantic" grammatical category specific deficit, and (b) lexical organization in multilingual speakers shares grammatical class information between languages. The findings of this study contribute to our understanding of the architecture of lexical organization in bilinguals.

  11. From Perceptual Categories to Concepts: What Develops?

    Science.gov (United States)

    Sloutsky, Vladimir M.

    2010-01-01

    People are remarkably smart: they use language, possess complex motor skills, make non-trivial inferences, develop and use scientific theories, make laws, and adapt to complex dynamic environments. Much of this knowledge requires concepts and this paper focuses on how people acquire concepts. It is argued that conceptual development progresses from simple perceptual grouping to highly abstract scientific concepts. This proposal of conceptual development has four parts. First, it is argued that categories in the world have different structure. Second, there might be different learning systems (sub-served by different brain mechanisms) that evolved to learn categories of differing structures. Third, these systems exhibit differential maturational course, which affects how categories of different structures are learned in the course of development. And finally, an interaction of these components may result in the developmental transition from perceptual groupings to more abstract concepts. This paper reviews a large body of empirical evidence supporting this proposal. PMID:21116483

  12. Lectures on tensor categories and modular functors

    CERN Document Server

    Bakalov, Bojko

    2000-01-01

    This book gives an exposition of the relations among the following three topics: monoidal tensor categories (such as a category of representations of a quantum group), 3-dimensional topological quantum field theory, and 2-dimensional modular functors (which naturally arise in 2-dimensional conformal field theory). The following examples are discussed in detail: the category of representations of a quantum group at a root of unity and the Wess-Zumino-Witten modular functor. The idea that these topics are related first appeared in the physics literature in the study of quantum field theory. Pioneering works of Witten and Moore-Seiberg triggered an avalanche of papers, both physical and mathematical, exploring various aspects of these relations. Upon preparing to lecture on the topic at MIT, however, the authors discovered that the existing literature was difficult and that there were gaps to fill. The text is wholly expository and finely succinct. It gathers results, fills existing gaps, and simplifies some pro...

  13. Multimedia category preferences of working engineers

    Science.gov (United States)

    Baukal, Charles E.; Ausburn, Lynna J.

    2016-09-01

    Many have argued for the importance of continuing engineering education (CEE), but relatively few recommendations were found in the literature for how to use multimedia technologies to deliver it most effectively. The study reported here addressed this gap by investigating the multimedia category preferences of working engineers. Four categories of multimedia, with two types in each category, were studied: verbal (text and narration), static graphics (drawing and photograph), dynamic non-interactive graphics (animation and video), and dynamic interactive graphics (simulated virtual reality (VR) and photo-real VR). The results showed that working engineers strongly preferred text over narration and somewhat preferred drawing over photograph, animation over video, and simulated VR over photo-real VR. These results suggest that a variety of multimedia types should be used in the instructional design of CEE content.

  14. Shape configuration and category-specificity

    DEFF Research Database (Denmark)

    Gerlach, Christian; Law, I; Paulson, Olaf B.

    2006-01-01

    and fragmented drawings. We also examined whether fragmentation had different impact on the recognition of natural objects and artefacts and found that recognition of artefacts was more affected by fragmentation than recognition of natural objects. Thus, the usual finding of an advantage for artefacts...... in difficult object decision tasks, which is also found in the present experiments with outlines, is reversed when the stimuli are fragmented. This interaction between category (natural versus artefacts) and stimulus type (outlines versus fragmented forms) is in accordance with predictions derived from...... a recent account of category-specificity and lends support to the notion that category-specific impairments can occur for both natural objects and artefacts following damage to pre-semantic stages in visual object recognition. The implications of the present findings are discussed in relation to theories...

  15. Functional categories in agrammatism: evidence from Greek.

    Science.gov (United States)

    Stavrakaki, Stavroula; Kouvava, Sofia

    2003-07-01

    The aim of this study is twofold. First, to investigate the use of functional categories by two Greek agrammatic aphasics. Second, to discuss the implications of our findings for the characterization of the deficit in agrammatism. The functional categories under investigation were the following: definite and indefinite articles, personal pronouns, aspect, tense, subject-verb agreement, wh-pronouns, complementizers and the mood marker na (=to). Based on data collected through different methods, it is argued that the deficit in agrammatism cannot be described in terms of a structural account but rather by means of difficulties in the implementation of grammatical knowledge.

  16. How to Do Things with Categories

    DEFF Research Database (Denmark)

    Krabbe, Anders Dahl

    Consumers and other audiences draw upon cognitive categories when evaluating technological products (Clark, 1985; Kaplan and Tripsas, 2008). Categories such as “mini-van” or “computer” provide labels and conceptual meaning structures that consumers and other market actors draw upon in making sense...... the majority of archival data was collected. Finally, to trace consumer reception of innovations in the design of products and technological innovations, I constructed a data set based on posts from an online hearing aid consumer forum. The initial analysis each spawned into three distinct trajectories...

  17. Fracture Resistance of Ceramic Laminate Veneers Bonded to Teeth with Class V Composite Fillings after Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Leyla Sadighpour

    2018-01-01

    Full Text Available Purpose. Porcelain laminate veneers (PLVs are sometimes required to be used for teeth with composite fillings. This study examined the fracture strength of PLVs bonded to the teeth restored with different sizes of class V composite fillings. Materials and Methods. Thirty-six maxillary central incisors were divided into three groups (n=12: intact teeth (control and teeth with class V composite fillings of one-third or two-thirds of the crown height (small or large group, resp.. PLVs were made by using IPS e.max and bonded with a resin cement (RelyX Unicem. Fracture resistance (N was measured after cyclic loading (1 × 106 cycles, 1.2 Hz. For statistical analyses, one-way ANOVA and Tukey test were used (α=0.05. Results. There was a significant difference between the mean failure loads of the test groups (P=0.004, with the Tukey-HSD test showing lower failure loads in the large-composite group compared to the control (P=0.02 or small group (P=0.05. The control and small-composite groups achieved comparable results (P>0.05. Conclusions. Failure loads of PLVs bonded to intact teeth and to teeth with small class V composite fillings were not significantly different. However, extensive composite fillings could compromise the bonding of PLVs.

  18. Remote monitoring of air movement through a high-rise, brick veneer and steel-stud wall system

    Energy Technology Data Exchange (ETDEWEB)

    Niemeyer, T.A.; Genge, G.R. [GRG Building Consultants Inc. (Canada)

    2011-07-01

    Since the early 20th century, research on building enclosures has been going on in the form of field investigations and laboratory testing, but real-time monitoring of buildings is relatively new. Compact sensors and programmable data logging equipment have allowed thorough, real-time trend analysis of occupied buildings. This paper discusses the remote monitoring of air movement using a high-rise brick veneer and steel-stud wall system. This equipment was installed across the exterior wall assembly. Temperature and air moisture content within the stud cavity and outdoor to indoor air pressure difference was measured across the entire assembly and in series across the various components of the wall. For outdoor conditions, local airport weather records were used. Comparing collected temperature data and the theoretical thermal model, it was concluded that there was air leakage. From the overall project, lessons learned included that is was important to minimize discomfort, both in aesthetics and in the number of requests for access to homes for analyses.

  19. Effect of light-curing method and indirect veneering materials on the Knoop hardness of a resin cement

    Directory of Open Access Journals (Sweden)

    Nelson Tetsu Iriyama

    2009-06-01

    Full Text Available This study evaluated the Knoop hardness of a dual-cured resin cement (Rely-X ARC activated solely by chemical reaction (control group or by chemical / physical mode, light-cured through a 1.5 mm thick ceramic (HeraCeram or composite (Artglass disc. Light curing was carried out using conventional halogen light (XL2500 for 40 s (QTH; light emitting diodes (Ultrablue Is for 40 s (LED; and Xenon plasma arc (Apollo 95E for 3 s (PAC. Bovine incisors had their buccal face flattened and hybridized. On this surface a rubber mold (5 mm in diameter and 1 mm in height was bulk filled with the resin cement. A polyester strip was seated for direct light curing or through the discs of veneering materials. After dry storage in the dark (24 h 37°C, the samples (n = 5 were sectioned for hardness (KHN measurements, taken in a microhardness tester (50 gF load 15 s. The data were statistically analyzed by ANOVA and Tukey's test (α = 0.05. The cement presented higher Knoop hardness values with Artglass for QTH and LED, compared to HeraCeram. The control group and the PAC/Artglass group showed lower hardness values compared to the groups light-cured with QTH and LED. PAC/HeraCeram resulted in the worst combination for cement hardness values.

  20. Retrospective Study of Retention of Stainless Steel Crowns and Pre-veneered Crowns on Primary Anterior Teeth.

    Science.gov (United States)

    Lopez-Loverich, Angela M; Garcia, Maria Minerva; Donly, Kevin J

    2015-01-01

    The purpose of this retrospective chart review was to explore the retention of anterior pre-veneered stainless steel crowns (NuSmile) and conventional stainless steel crowns (3M ESPE) placed on primary anterior teeth. Records for children were reviewed over four years using the electronic record system axiUm. Data collected included child's age at time of crown placement, date of placement, tooth number, type of crown, patient behavior, treatment environment, provider type, crown presence, absence, and cementation success or failure at subsequent recall visits. A total of 637 anterior crowns in children treated with either or both crown types met this study's inclusion criteria. Of these crowns, 483 were NuSmile Signature crowns and 154 were stainless steel crowns. There was a nine percent failure rate for the NuSmile Signature crowns and a seven percent failure rate for the stainless steel crowns. There was no statistically significant difference in crown retention rates between the two groups (P<0.05). A full-coverage restoration that can follow the lifespan of the primary anterior dentition in high-risk children is needed. The results from this study indicate good crown retention rates for both crown types with no statistically significant difference between them (P<0.05).

  1. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers.

    Science.gov (United States)

    Mahmood, Deyar Jallal Hadi; Linderoth, Ewa H; Wennerberg, Ann; Vult Von Steyern, Per

    2016-01-01

    To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) fixed dental prostheses (FDPs) with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP cores. A total of 110 three-unit Y-TZP FDP cores with one intermediate pontic were made. The FDP cores in groups 1-7 were made with a split-file design, veneered with manually built-up porcelain, computer-aided design-on veneers, and over-pressed veneers. Groups 8-11 consisted of FDPs with a state-of-the-art design, veneered with manually built-up porcelain. All the FDP cores were subjected to simulated aging and finally loaded to fracture. There was a significant difference (Pdesigns, but not between the different types of Y-TZP materials. The split-file designs with VITABLOCS(®) (1,806±165 N) and e.max(®) ZirPress (1,854±115 N) and the state-of-the-art design with VITA VM(®) 9 (1,849±150 N) demonstrated the highest mean fracture values. The shape of a split-file designed all-ceramic reconstruction calls for a different dimension protocol, compared to traditionally shaped ones, as the split-file design leads to sharp approximal indentations acting as fractural impressions, thus decreasing the overall strength. The design of a framework is a crucial factor for the load bearing capacity of an all-ceramic FDP. The state-of-the-art design is preferable since the split-file designed cores call for a cross-sectional connector area at least 42% larger, to have the same load bearing capacity as the state-of-the-art designed cores. All veneering materials and techniques tested in the study, split-file, over-press, built-up porcelains, and glass-ceramics are, with a great safety margin, sufficient for clinical use both anteriorly and posteriorly. Analysis of the fracture pattern shows

  2. Language specific bootstraps for UG categories

    NARCIS (Netherlands)

    van Kampen, N.J.

    2005-01-01

    This paper argues that the universal categories N/V are not applied to content words before the grammatical markings for reference D(eterminers) and predication I(nflection) have been acquired (van Kampen, 1997, contra Pinker, 1984). Child grammar starts as proto-grammar with language-specific

  3. Quantum logic in dagger kernel categories

    NARCIS (Netherlands)

    Heunen, C.; Jacobs, B.P.F.

    2009-01-01

    This paper investigates quantum logic from the perspective of categorical logic, and starts from minimal assumptions, namely the existence of involutions/daggers and kernels. The resulting structures turn out to (1) encompass many examples of interest, such as categories of relations, partial

  4. Quantum logic in dagger kernel categories

    NARCIS (Netherlands)

    Heunen, C.; Jacobs, B.P.F.; Coecke, B.; Panangaden, P.; Selinger, P.

    2011-01-01

    This paper investigates quantum logic from the perspective of categorical logic, and starts from minimal assumptions, namely the existence of involutions/daggers and kernels. The resulting structures turn out to (1) encompass many examples of interest, such as categories of relations, partial

  5. New Evidence for Infant Colour Categories

    Science.gov (United States)

    Franklin, Anna; Davies, Ian R. L.

    2004-01-01

    Bornstein, Kessen, and Weiskopf (1976) reported that pre-linguistic infants perceive colour categorically for primary boundaries: Following habituation, dishabituation only occurred if the test stimulus was from a different adult category to the original. Here, we replicated this important study and extended it to include secondary boundaries,…

  6. Ethnicity in censuses: Changeable and inconstant category

    Directory of Open Access Journals (Sweden)

    Mrđen Snježana

    2002-01-01

    Full Text Available The issue of ethnicity was set in all censuses of SFRY, as well as in the first censuses in countries that were created after its disintegration. When analyzing the censuses it can be concluded that it is a changeable category. Not only was the manner of forming the question in censuses changing, but also the number of categories of nationality and their order in published census' results. It depended on state policy and the political situation preceding the censuses. Since the answer on the issues of ethnicity is a subjective criterion, and it was written down according to the freely declared statement of the residents, guaranteed by the Constitution. It has often happened that same individuals have declared themselves differently from one census to another, and also some categories of ethnicity have vanished and some others were created. Although in SFRY nations and ethnicities were equal, still indirectly in published results, existence of these two categories was indicated. But, in newly created countries, the manner of forming the question of ethnicity was changed, their number and order were also changed and the notion of 'minority' was again introduced, indicating, beyond doubt, a different status of nationality (except the majority from the one in the former Yugoslavia.

  7. 40 CFR 2.105 - Exemption categories.

    Science.gov (United States)

    2010-07-01

    ... the mandatory disclosure requirements of 5 U.S.C. 552(a): (1)(i) Specifically authorized under... enforcement investigations or prosecutions if such disclosure could reasonably be expected to risk... for Disclosure of Records Under the Freedom of Information Act § 2.105 Exemption categories. (a) The...

  8. Reliability of Multi-Category Rating Scales

    Science.gov (United States)

    Parker, Richard I.; Vannest, Kimberly J.; Davis, John L.

    2013-01-01

    The use of multi-category scales is increasing for the monitoring of IEP goals, classroom and school rules, and Behavior Improvement Plans (BIPs). Although they require greater inference than traditional data counting, little is known about the inter-rater reliability of these scales. This simulation study examined the performance of nine…

  9. 21 CFR 330.5 - Drug categories.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Drug categories. 330.5 Section 330.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN...) Stimulants. (r) Antitussives. (s) Allergy treatment products. (t) Cold remedies. (u) Antirheumatic products...

  10. Shape configuration and category-specificity

    DEFF Research Database (Denmark)

    Gerlach, Christian; Law, Ian; Paulson, Olaf B

    2006-01-01

    in difficult object decision tasks, which is also found in the present experiments with outlines, is reversed when the stimuli are fragmented. This interaction between category (natural versus artefacts) and stimulus type (outlines versus fragmented forms) is in accordance with predictions derived from...

  11. Structural similarity and category-specificity

    DEFF Research Database (Denmark)

    Gerlach, Christian; Law, Ian; Paulson, Olaf B

    2004-01-01

    It has been suggested that category-specific recognition disorders for natural objects may reflect that natural objects are more structurally (visually) similar than artefacts and therefore more difficult to recognize following brain damage. On this account one might expect a positive relationshi...

  12. Ontological semantics in modified categorial grammar

    DEFF Research Database (Denmark)

    Szymczak, Bartlomiej Antoni

    2009-01-01

    Categorial Grammar is a well established tool for describing natural language semantics. In the current paper we discuss some of its drawbacks and how it could be extended to overcome them. We use the extended version for deriving ontological semantics from text. A proof-of-concept implementation...

  13. Semantic category interference in overt picture naming

    NARCIS (Netherlands)

    Maess, B.; Friederici, A.D.; Damian, M.F.; Meyer, A.S.; Levelt, W.J.M.

    2002-01-01

    The study investigated the neuronal basis of the retrieval of words from the mental lexicon. The semantic category interference effect was used to locate lexical retrieval processes in time and space. This effect reflects the finding that, for overt naming, volunteers are slower when naming pictures

  14. Multimedia Category Preferences of Working Engineers

    Science.gov (United States)

    Baukal, Charles E., Jr.; Ausburn, Lynna J.

    2016-01-01

    Many have argued for the importance of continuing engineering education (CEE), but relatively few recommendations were found in the literature for how to use multimedia technologies to deliver it most effectively. The study reported here addressed this gap by investigating the multimedia category preferences of working engineers. Four categories…

  15. Focal colors across languages are representative members of color categories.

    Science.gov (United States)

    Abbott, Joshua T; Griffiths, Thomas L; Regier, Terry

    2016-10-04

    Focal colors, or best examples of color terms, have traditionally been viewed as either the underlying source of cross-language color-naming universals or derived from category boundaries that vary widely across languages. Existing data partially support and partially challenge each of these views. Here, we advance a position that synthesizes aspects of these two traditionally opposed positions and accounts for existing data. We do so by linking this debate to more general principles. We show that best examples of named color categories across 112 languages are well-predicted from category extensions by a statistical model of how representative a sample is of a distribution, independently shown to account for patterns of human inference. This model accounts for both universal tendencies and variation in focal colors across languages. We conclude that categorization in the contested semantic domain of color may be governed by principles that apply more broadly in cognition and that these principles clarify the interplay of universal and language-specific forces in color naming.

  16. Typicality Mediates Performance during Category Verification in Both Ad-Hoc and Well-Defined Categories

    Science.gov (United States)

    Sandberg, Chaleece; Sebastian, Rajani; Kiran, Swathi

    2012-01-01

    Background: The typicality effect is present in neurologically intact populations for natural, ad-hoc, and well-defined categories. Although sparse, there is evidence of typicality effects in persons with chronic stroke aphasia for natural and ad-hoc categories. However, it is unknown exactly what influences the typicality effect in this…

  17. Uncovering Contrast Categories in Categorization with a Probabilistic Threshold Model

    Science.gov (United States)

    Verheyen, Steven; De Deyne, Simon; Dry, Matthew J.; Storms, Gert

    2011-01-01

    A contrast category effect on categorization occurs when the decision to apply a category term to an entity not only involves a comparison between the entity and the target category but is also influenced by a comparison of the entity with 1 or more alternative categories from the same domain as the target. Establishing a contrast category effect…

  18. Correspondence between Grammatical Categories and Grammatical Functions in Chinese.

    Science.gov (United States)

    Tan, Fu

    1993-01-01

    A correspondence is shown between grammatical categories and grammatical functions in Chinese. Some syntactic properties distinguish finite verbs from nonfinite verbs, nominals from other categories, and verbs from other categories. (Contains seven references.) (LB)

  19. Category-length and category-strength effects using images of scenes.

    Science.gov (United States)

    Baumann, Oliver; Vromen, Joyce M G; Boddy, Adam C; Crawshaw, Eloise; Humphreys, Michael S

    2018-06-21

    Global matching models have provided an important theoretical framework for recognition memory. Key predictions of this class of models are that (1) increasing the number of occurrences in a study list of some items affects the performance on other items (list-strength effect) and that (2) adding new items results in a deterioration of performance on the other items (list-length effect). Experimental confirmation of these predictions has been difficult, and the results have been inconsistent. A review of the existing literature, however, suggests that robust length and strength effects do occur when sufficiently similar hard-to-label items are used. In an effort to investigate this further, we had participants study lists containing one or more members of visual scene categories (bathrooms, beaches, etc.). Experiments 1 and 2 replicated and extended previous findings showing that the study of additional category members decreased accuracy, providing confirmation of the category-length effect. Experiment 3 showed that repeating some category members decreased the accuracy of nonrepeated members, providing evidence for a category-strength effect. Experiment 4 eliminated a potential challenge to these results. Taken together, these findings provide robust support for global matching models of recognition memory. The overall list lengths, the category sizes, and the number of repetitions used demonstrated that scene categories are well-suited to testing the fundamental assumptions of global matching models. These include (A) interference from memories for similar items and contexts, (B) nondestructive interference, and (C) that conjunctive information is made available through a matching operation.

  20. Occupational exposure to the personnel regarded by NRB-76/87 to B category

    Energy Technology Data Exchange (ETDEWEB)

    Gubatova, D; Balode, G; Nemiro, E [Medical Institute, Riga (USSR)

    1990-01-01

    During the decades use of radioactive sources in all branches of national economy has increased. Due to this tendency the number of exposed individuals from artificial sources including those exposed only occasionally (the so-called B category) increases. For this category the personnel dosimetry is not obligatory, and radioactive monitoring of their working and living places would do. Nevertheless, the thermoluminescent personnel monitoring data derived by us show that occupational exposure of this category is near, and occasionally even higher than B category exposure limit. So, for example, anesthesiologists annual exposure makes 4.5 mSv, that of surgeons 6.5 mSv, of anesthetic nurses 4.0 mSv (Traumatological and Orthopedic Institute personnel). Annual exposure of 'Medtekhnika' factory electromechanics ought to repair, set up and check up X-ray devices in 1987 was 5 mSv. (author).

  1. TO THE QUESTION OF PROFIT CATEGORY

    Directory of Open Access Journals (Sweden)

    V. V. Myamlin

    2009-08-01

    Full Text Available The economic category “profit” is considered. The discrepancies and inconsistency of the existing financial-andeconomic model of management based only upon the “profitable” paradigm is demonstrated. It is shown how a “profit” affects a discrepancy between the supply of goods and the related solvent demand. It is suggested to build the laws of economics starting not from the private interests of separate social groups but from the universal laws of the Nature. The transition from “profit” maximization to wages/salary maximization is recommended. It is proposed to exclude a category “profit” from the financial-and-economic model of management as an unnecessary and imaginary one that continuously leads the economic system to crisis.

  2. Energy Data Base: subject categories and scope

    International Nuclear Information System (INIS)

    Bost, D.E.

    1985-03-01

    The subject scope of the Energy Data Base (EDB) encompasses all DOE-sponsored research. Broadly defined, EDB subject scope includes all technological aspects of energy production, conversion, and efficient utilization, and the economic, social, and political aspects as well. Scope notes are provided to define the extent of interest in certain subject areas, particularly areas of basic research. Cross references between categories are provided to aid both the categorization of information and its retrieval. Citations entered into DOE's computerized bibliographic information system are assigned six-digit subject category numbers to broadly group information for storage, retrieval, and manipulation. These numbers are used in the preparation of printed documents, such as bibliographies and abstract journals, to arrange the citations and to aid searching on the DOE/RECON on-line system

  3. Subject categories with scope definitions and limitations

    International Nuclear Information System (INIS)

    Bost, D.E.

    1983-08-01

    Citations entered into DOE's computerized bibliographic information system are assigned six-digit subject category numbers to broadly group information for storage, retrieval, and manipulation. These numbers are used in the preparation of printed documents, such as bibliographies and abstract journals, to arrange the citations and to aid searching on the DOE/RECON on-line system. This document has been prepared for use by (1) those individuals responsible for the assignment of category numbers to documents being entered into the Technical Information Center (TIC) system, (2) those individuals and organizations processing magnetic tape copies of the files, (3) those individuals doing on-line searching for information in TIC-created files, and (4) others who, having no access to RECON, need a printed copy

  4. Health effects of risk-assessment categories

    International Nuclear Information System (INIS)

    Kramer, C.F.; Rybicka, K.; Knutson, A.; Morris, S.C.

    1983-10-01

    Environmental and occupational health effects associated with exposures to various chemicals are a subject of increasing concern. One recently developed methodology for assessing the health impacts of various chemical compounds involves the classification of similar chemicals into risk-assessment categories (RACs). This report reviews documented human health effects for a broad range of pollutants, classified by RACs. It complements other studies that have estimated human health effects by RAC based on analysis and extrapolation of data from animal research

  5. Sacrality and worldmaking: new categorial perspectives

    OpenAIRE

    William E. Paden

    1999-01-01

    The category of the sacred in particular and the role of transcultural concept-formation in general have undergone an obvious crisis. For the most part, "the sacred," if not an empty label, has been linked with theologism, and transcultural concepts have been condemned for their general non-comparability and colonialist intent. The author approaches the matter of transcultural templates through an analysis of certain concepts of sacrality. With some exceptions, the discourse of sacrality has ...

  6. 40 CFR 156.62 - Toxicity Category.

    Science.gov (United States)

    2010-07-01

    .... Acute Toxicity Categories for Pesticide Products Hazard Indicators I II III IV Oral LD50 Up to and including 50 mg/kg >50 thru 500 mg/kg >500 thru 5,000 mg/kg >5,000 mg/kg Dermal LD50 Up to and including 200 mg/kg >200 thru 2000 mg/kg >2000 thru 20,000 mg/kg >20,000 mg/kg Inhalation LC50 Up to and including...

  7. Health effects of risk-assessment categories

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, C.F.; Rybicka, K.; Knutson, A.; Morris, S.C.

    1983-10-01

    Environmental and occupational health effects associated with exposures to various chemicals are a subject of increasing concern. One recently developed methodology for assessing the health impacts of various chemical compounds involves the classification of similar chemicals into risk-assessment categories (RACs). This report reviews documented human health effects for a broad range of pollutants, classified by RACs. It complements other studies that have estimated human health effects by RAC based on analysis and extrapolation of data from animal research.

  8. Metacognitive control of categorial neurobehavioral decision systems

    Directory of Open Access Journals (Sweden)

    Gordon Robert Foxall

    2016-02-01

    Full Text Available The competing neuro-behavioral decision systems (CNDS model proposes that the degree to which an individual discounts the future is a function of the relative hyperactivity of an impulsive system based on the limbic and paralimbic brain regions and the relative hypoactivity of an executive system based in prefrontal cortex (PFC. The model depicts the relationship between these categorial systems in terms of the antipodal neurophysiological, behavioral, and decision (cognitive functions that engender classes normal and addictive responding. However, a case may be made for construing several components of the impulsive and executive systems depicted in the model as categories (elements of additional systems that are concerned with the metacognitive control of behavior. Hence, this paper proposes a category-based structure for understanding the effects on behavior of CNDS, which includes not only the impulsive and executive systems of the basic model but, a superordinate level of reflective or rational decision-making. Following recent developments in the modeling of cognitive control which contrasts Type 1 (rapid, autonomous, parallel processing with Type 2 (slower, computationally-demanding, sequential processing, the proposed model incorporates an arena in which the potentially conflicting imperatives of impulsive and executive systems are examined and from which a more appropriate behavioral response than impulsive choice emerges. This configuration suggests a forum in which the interaction of picoeconomic interests, which provide a cognitive dimension for CNDS, can be conceptualized. This proposition is examined in light of the resolution of conflict by means of bundling.

  9. Dental implant suprastructures using cobalt-chromium alloy compared with gold alloy framework veneered with ceramic or acrylic resin: a retrospective cohort study up to 18 years.

    Science.gov (United States)

    Teigen, Kyrre; Jokstad, Asbjørn

    2012-07-01

    An association between the long-term success and survival of implant-supported prostheses as a function of biomaterial combinations has not been established. The use of cast cobalt-chromium for the suprastructure framework may be an alternative to the conventional approach of using type 3 gold alloys. A retrospective chart audit of all patients who had received implant-supported fixed dental prostheses (FDP) before 1996 was identified in a private practice clinic. Data were recorded for FDPs made from four combinations of alloy frameworks and veneering material, i.e. type 3 gold and cobalt-chromium with ceramic or prefabricated acrylic teeth. The extracted data from the charts were subjected to explorative statistical tests including Kaplan-Meier survival analyses. Patients (n=198) with 270 short and extensive FDPs supported entirely by 1117 implants were identified. The average follow-up observation periods varied between 4 and 220 months, with an average of 120 months. The success and survival, as well as event rates and types of biological and technical complications, were similar for implant-supported FDPs using cobalt-chromium and type 3 gold alloy frameworks veneered with ceramics or prefabricated acrylic teeth. An influence of the suprastructure biomaterial combination on the clinical performance of the individual supporting implants could not be established. Implant-supported FDPs made from type 3 gold or cobalt-chromium frameworks and veneered with ceramic or prefabricated acrylic teeth demonstrate comparable clinical performance. The biomaterial combinations do not appear to influence the success or survival of the individual implants. © 2011 John Wiley & Sons A/S.

  10. INFLUENCE OF SILANE HEAT TREATMENT ON THE TENSILE BOND STRENGTH BETWEEN EX-3 SYNTHETIC VENEERING PORCELAIN AND COMPOSITE RESIN USING FIVE DIFFERENT ACTIVATION TEMPERATURES

    Directory of Open Access Journals (Sweden)

    Spartak Yanakiev

    2017-02-01

    Full Text Available Purpose: The purpose of the present study is to assess the effect of five different silane activation temperatures and eight activation methods on the tensile bond strength between one veneering porcelain and one composite resin material. Material and methods: A total of 81 ceramic rods were made of EX-3 veneering ceramic (Kuraray Noritake Dental, Japan. Sintered ceramic bars were grinded with diamond disks to size 10x2x2mm ± 0,05mm. The front part of each bar was polished. After ultrasonic cleaning in distilled water, the specimens were divided into nine groups. Silane was activated with air at room temperature, 38º С, 50º С, 100º С, 120º С using a custom made blow drier. In a silicone mold, a composite resin Z250 (3М ESPE, St. Paul, USA was condensed toward the bond ceramic surface. A total of 81 specimens approximately 2,0 cm long were prepared for tensile bond testing. One way ANOVA, followed by Bonferroni and Games-Howell tests were used for statistical analysis. Results: The lowest tensile bond strength was observed in the control group (3,51MPa. Group 2 yielded the highest bond strength among all groups (19,54MPa. Silane heat treatment enhanced the bond strength for all treatment methods. Within the polished specimens, the highest bond strength was yielded with warm air at 120ºС (11,31MPa. Conclusion: The most effective method for bonding Z250 composite resin to EX-3 veneering ceramic includes HF etching, silane, and adhesive resin. The most effective heat treatment method for bonding is hot air at 120ºС.

  11. Surface photo-discoloration and degradation of dyed wood veneer exposed to different wavelengths of artificial light

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yi [MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing 100083 (China); Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083 (China); MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing 100083 (China); Forest Products Development Center, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36830 (United States); Shao, Lingmin [MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing 100083 (China); Gao, Jianmin, E-mail: jmgao@bjfu.edu.cn [MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing 100083 (China); Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083 (China); MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing 100083 (China); Guo, Hongwu, E-mail: hwg5052@163.com [MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing 100083 (China); Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083 (China); MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing 100083 (China); Chen, Yao [MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing 100083 (China); Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083 (China); MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing 100083 (China); Cheng, Qingzheng; Via, Brian K. [Forest Products Development Center, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36830 (United States)

    2015-03-15

    Highlights: • Investigate the selective absorption of different wavelengths of UV–vis light by dyed wood chromophores. • Identify connection between light wavelengths and surface color changes and chemical structure degradation. • Study hypochromic effect based on surface reflectance and K/S absorption changes during UV–vis irradiation. - Abstract: The surface of dyed wood is prone to discoloration when exposed to light irradiation which significantly decreases its decorative effect and shortens its service life. The influence of light wavelength exposure to the surface of dyed wood was investigated to study the effect on discoloration and degradation. Acid Blue V and Acid Red GR dyed wood veneers were subjected to light exposure with different wavelengths from the UV to visible region (254–420 nm). Results showed that the surface discoloration of dyed wood was linearly related to lignin concentration and dyes degradation and the consequent transformation of chromophoric groups such as aromatic (C=C) and carbonyl (C=O) through methoxy reaction. The dyes, lignin and some active constituents were degraded severely, even at short exposures. Acid Blue V dyed wood exhibited greater discoloration than the Acid Red GR treatment. The reflectance and K/S absorption curve showed a hypochromic effect on the dyed wood surface. The dyes and wood chemical structure played a complex and combined role on the selective absorption of different wavelengths of light. The color change rate was apparent with 254 nm exposure in the initial stages, but a greater discoloration rate occurred on the samples irradiated at 313 and 340 nm than at 254 and 420 nm with the time prolonged. The degradation rate and degree of discoloration correlated well with the light energy and wavelength.

  12. Tracing metal-silicate segregation and late veneer in the Earth and the ureilite parent body with palladium stable isotopes

    Science.gov (United States)

    Creech, J. B.; Moynier, F.; Bizzarro, M.

    2017-11-01

    Stable isotope studies of highly siderophile elements (HSE) have the potential to yield valuable insights into a range of geological processes. In particular, the strong partitioning of these elements into metal over silicates may lead to stable isotope fractionation during metal-silicate segregation, making them sensitive tracers of planetary differentiation processes. We present the first techniques for the precise determination of palladium stable isotopes by MC-ICPMS using a 106Pd-110Pd double-spike to correct for instrumental mass fractionation. Results are expressed as the per mil (‰) difference in the 106Pd/105Pd ratio (δ106Pd) relative to an in-house solution standard (Pd_IPGP) in the absence of a certified Pd isotopic standard. Repeated analyses of the Pd isotopic composition of the chondrite Allende demonstrate the external reproducibility of the technique of ±0.032‰ on δ106Pd. Using these techniques, we have analysed Pd stable isotopes from a range of terrestrial and extraterrestrial samples. We find that chondrites define a mean δ106Pdchondrite = -0.19 ± 0.05‰. Ureilites reveal a weak trend towards heavier δ106Pd with decreasing Pd content, similar to recent findings based on Pt stable isotopes (Creech et al., 2017), although fractionation of Pd isotopes is significantly less than for Pt, possibly related to its weaker metal-silicate partitioning behaviour and the limited field shift effect. Terrestrial mantle samples have a mean δ106Pdmantle = -0.182 ± 0.130‰, which is consistent with a late-veneer of chondritic material after core formation.

  13. Shear bond strength of porcelain laminate veneers to enamel, dentine and enamel-dentine complex bonded with different adhesive luting systems.

    Science.gov (United States)

    Öztürk, Elif; Bolay, Şükran; Hickel, Reinhard; Ilie, Nicoleta

    2013-02-01

    The aim of this study was to evaluate the shear bond strength of porcelain laminate veneers to 3 different surfaces by means of enamel, dentine, and enamel-dentine complex. One hundred thirty-five extracted human maxillary central teeth were used, and the teeth were randomly divided into 9 groups (n=15). The teeth were prepared with 3 different levels for bonding surfaces of enamel (E), dentine (D), and enamel-dentine complex (E-D). Porcelain discs (IPS e.max Press, Ivoclar Vivadent) of 2mm in thickness and 4mm in diameter were luted to the tooth surfaces by using 2 light-curing (RelyX Veneer [RV], 3M ESPE; Variolink Veneer [VV], Ivoclar Vivadent) and a dual-curing (Variolink II [V2], Ivoclar Vivadent) adhesive systems according to the manufacturers' instructions. Shear bond strength test was performed in a universal testing machine at 0.5mm/min until bonding failure. Failure modes were determined under a stereomicroscope, and fracture surfaces were evaluated with a scanning electron microscope. The data were statistically analysed (SPSS 17.0) (p=0.05). Group RV-D exhibited the lowest bond strength value (5.42±6.6MPa). There was statistically no difference among RV-D, V2-D (13.78±8.8MPa) and VV-D (13.84±6.2MPa) groups (p>0.05). Group VV-E exhibited the highest bond strength value (24.76±8.8MPa). The type of tooth structure affected the shear bond strength of the porcelain laminate veneers to the 3 different types of tooth structures (enamel, dentine, and enamel-dentine complex). When dentine exposure is necessary during preparation, enough sound enamel must be protected as much as possible to maintain a good bonding; to obtain maximum bond strength, preparation margins should be on sound enamel. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Semantic category interference in overt picture naming: sharpening current density localization by PCA.

    Science.gov (United States)

    Maess, Burkhard; Friederici, Angela D; Damian, Markus; Meyer, Antje S; Levelt, Willem J M

    2002-04-01

    The study investigated the neuronal basis of the retrieval of words from the mental lexicon. The semantic category interference effect was used to locate lexical retrieval processes in time and space. This effect reflects the finding that, for overt naming, volunteers are slower when naming pictures out of a sequence of items from the same semantic category than from different categories. Participants named pictures blockwise either in the context of same- or mixed-category items while the brain response was registered using magnetoencephalography (MEG). Fifteen out of 20 participants showed longer response latencies in the same-category compared to the mixed-category condition. Event-related MEG signals for the participants demonstrating the interference effect were submitted to a current source density (CSD) analysis. As a new approach, a principal component analysis was applied to decompose the grand average CSD distribution into spatial subcomponents (factors). The spatial factor indicating left temporal activity revealed significantly different activation for the same-category compared to the mixed-category condition in the time window between 150 and 225 msec post picture onset. These findings indicate a major involvement of the left temporal cortex in the semantic interference effect. As this effect has been shown to take place at the level of lexical selection, the data suggest that the left temporal cortex supports processes of lexical retrieval during production.

  15. The role of Late Veneer impacts in the evolution of Venus

    Science.gov (United States)

    Gillmann, C.; Golabek, G.; Tackley, P.; Raymond, S.

    2017-09-01

    We study how different mechanisms contribute to changes in long term evolution. In particular, the primitive history (the first Gy) of terrestrial planets is heavily influenced by collisions. We investigate how the coupled evolution of Venus' atmosphere and mantle is modified by those impacts. We focus on volatile fluxes: atmospheric escape and mantle degassing. We observe that large impacts are unlikely to erode the atmosphere significantly. They are, on the contrary, an important source of volatiles for the primitive planet. Collisions also generate a lot of melting and rapidly dries the mantle through degassing. Without recycling of volatiles into the mantle (like in plate tectonics regime), the mantle is efficiently depleted.

  16. Radiation protection in category III large gamma irradiators; Radioprotecao em irradiadores de grande porte de categoria III

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Neivaldo; Furlan, Gilberto Ribeiro, E-mail: neivaldo@cena.usp.b, E-mail: gilfurlan@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Itepan, Natanael Marcio, E-mail: natanael.itepan@unianhanguera.edu.b [Universidade Anhanguera, Goiania, GO (Brazil)

    2011-07-01

    This article discusses the advantages of category III large gamma irradiator compared to the others, with emphasis on aspects of radiological protection, in the industrial sector. This category is a kind of irradiators almost unknown to the regulators authorities and the industrial community, despite its simple construction and greater radiation safety intrinsic to the model, able to maintain an efficiency of productivity comparable to those of category IV. Worldwide, there are installed more than 200 category IV irradiators and there is none of a category III irradiator in operation. In a category III gamma irradiator, the source remains fixed in the bottom of the tank, always shielded by water, negating the exposition risk. Taking into account the benefits in relation to radiation safety, the category III large irradiators are highly recommended for industrial, commercial purposes or scientific research. (author)

  17. Setters and samoyeds: the emergence of subordinate level categories as a basis for inductive inference in preschool-age children.

    Science.gov (United States)

    Waxman, S R; Lynch, E B; Casey, K L; Baer, L

    1997-11-01

    Basic level categories are a rich source of inductive inference for children and adults. These 3 experiments examine how preschool-age children partition their inductively rich basic level categories to form subordinate level categories and whether these have inductive potential. Children were taught a novel property about an individual member of a familiar basic level category (e.g., a collie). Then, children's extensions of that property to other objects from the same subordinate (e.g., other collies), basic (e.g., other dogs), and superordinate (e.g., other animals) level categories were examined. The results suggest (a) that contrastive information promotes the emergence of subordinate categories as a basis of inductive inference and (b) that newly established subordinate categories can retain their inductive potential in subsequent reasoning over a week's time.

  18. From groups to categorial algebra introduction to protomodular and mal’tsev categories

    CERN Document Server

    Bourn, Dominique

    2017-01-01

    This book gives a thorough and entirely self-contained, in-depth introduction to a specific approach to group theory, in a large sense of that word. The focus lie on the relationships which a group may have with other groups, via “universal properties”, a view on that group “from the outside”. This method of categorical algebra, is actually not limited to the study of groups alone, but applies equally well to other similar categories of algebraic objects. By introducing protomodular categories and Mal’tsev categories, which form a larger class, the structural properties of the category Gp of groups, show how they emerge from four very basic observations about the algebraic litteral calculus and how, studied for themselves at the conceptual categorical level, they lead to the main striking features of the category Gp of groups. Hardly any previous knowledge of category theory is assumed, and just a little experience with standard algebraic structures such as groups and monoids. Examples and exercises...

  19. Order of Presentation Effects in Learning Color Categories

    Science.gov (United States)

    Sandhofer, Catherine M.; Doumas, Leonidas A. A.

    2008-01-01

    Two studies, an experimental category learning task and a computational simulation, examined how sequencing training instances to maximize comparison and memory affects category learning. In Study 1, 2-year-old children learned color categories with three training conditions that varied in how categories were distributed throughout training and…

  20. Supervised and Unsupervised Learning of Multidimensional Acoustic Categories

    Science.gov (United States)

    Goudbeek, Martijn; Swingley, Daniel; Smits, Roel

    2009-01-01

    Learning to recognize the contrasts of a language-specific phonemic repertoire can be viewed as forming categories in a multidimensional psychophysical space. Research on the learning of distributionally defined visual categories has shown that categories defined over 1 dimension are easy to learn and that learning multidimensional categories is…

  1. Source Monitoring in Alzheimer's Disease

    Science.gov (United States)

    El Haj, Mohamad; Fasotti, Luciano; Allain, Philippe

    2012-01-01

    Source monitoring is the process of making judgments about the origin of memories. There are three categories of source monitoring: reality monitoring (discrimination between self- versus other-generated sources), external monitoring (discrimination between several external sources), and internal monitoring (discrimination between two types of…

  2. Antisocial behavior: Dimension or category(ies?

    Directory of Open Access Journals (Sweden)

    Biro Mikloš

    2008-01-01

    Full Text Available Classificatory systems (DSM-IV, ICD-10 use different criteria for defining a rather common antisocial disorder, traditionally referred as psychopathy. Most empirical studies of this phenomenon use Cleckley's operational definition that was applied and amended in Hare's revised Psychopathy Checklist (PCL-R. In modern literature, the fact that there is less than a perfect correspondence between classificatory systems and Hare's PCL-R is often cited as an indication that antisocial behavior is not confined to a distinct category of people but is rather a continuous personality dimension. In order to further elucidate the nosology of antisocial behaviors, a Psychopathy Assessment Questionnaire (PAQ based on Cleckley - Hare's criteria and consisting of 40 binary items was administered to 339 men (135 prisoners and 204 members of the general population. Four distinct clusters of respondents were identified by means of hierarchical cluster analysis: Psychopathic type (characterized by high positive scores on dimension of Unemotionality; Antisocial type (characterized by high positive scores on Social deviance dimension; Adapted type (characterized by negative scores on all dimensions; and Hyper-controlled type (characterized by extremely negative scores on dimension Social deviance accompanied with positive scores on Unemotionality dimension. Additional comparison with MMPI profiles which classified prison sample in two groups ("Psychopathic profiles" and "Non- Psychopathic profiles" shows that there is no expected compatibility between MMPI and PAQ. We conclude that Antisocial type can be treated as a distinct category, while Psychopathic type displays characteristics of dimensional distribution.

  3. Three-year clinical follow-up of posterior teeth restored with leucite-reinforced ips empress onlays and partial veneer crowns.

    Science.gov (United States)

    Murgueitio, Rafael; Bernal, Guillermo

    2012-07-01

    The aim of this study was to analyze the survival rate and failure mode of IPS leucite-reinforced ceramic onlays and partial veneer crowns regarding thickness under the following clinical conditions: vital versus nonvital teeth, tooth location, and type of opposing dentition. Teeth were prepared according to established guidelines for ceramic onlays and partial veneer crowns. Before cementation, the restorations were measured for occlusal thickness at the central fossa, mesial, and distal marginal ridges, and functional and nonfunctional cusps. A total of 210 ceramic restorations were cemented in 99 patients within a mean observation period of 2.9 ± 1.89 years. The mode of failure was classified and evaluated as (1) adhesive, (2) cohesive, (3) combined failure, (4) decementation, (5) tooth sensitivity, and (6) pulpal necrosis. Kaplan, log-rank, and Cox regression tests were used for statistical analysis. The failure rate was 3.33% (7/210). Increased material thickness produced less probability of failures. Vital teeth were less likely to fail than nonvital teeth. Second molars were five times more susceptible to failure than first molars. Tooth sensitivity postcementation and the type of opposing dentition were not statistically significant in this study. In this study, thickness of the restorations, tooth vitality, and location of teeth in the dental arch influenced restoration failures. © 2012 by the American College of Prosthodontists.

  4. Encoding tasks dissociate the effects of divided attention on category-cued recall and category-exemplar generation.

    Science.gov (United States)

    Parker, Andrew; Dagnall, Neil; Munley, Gary

    2012-01-01

    The combined effects of encoding tasks and divided attention upon category-exemplar generation and category-cued recall were examined. Participants were presented with pairs of words each comprising a category name and potential example of that category. They were then asked to indicate either (i) their liking for both of the words or (ii) if the exemplar was a member of the category. It was found that divided attention reduced performance on the category-cued recall task under both encoding conditions. However, performance on the category-exemplar generation task remained invariant across the attention manipulation following the category judgment task. This provides further evidence that the processes underlying performance on conceptual explicit and implicit memory tasks can be dissociated, and that the intentional formation of category-exemplar associations attenuates the effects of divided attention on category-exemplar generation.

  5. The helpfulness of category labels in semi-supervised learning depends on category structure.

    Science.gov (United States)

    Vong, Wai Keen; Navarro, Daniel J; Perfors, Amy

    2016-02-01

    The study of semi-supervised category learning has generally focused on how additional unlabeled information with given labeled information might benefit category learning. The literature is also somewhat contradictory, sometimes appearing to show a benefit to unlabeled information and sometimes not. In this paper, we frame the problem differently, focusing on when labels might be helpful to a learner who has access to lots of unlabeled information. Using an unconstrained free-sorting categorization experiment, we show that labels are useful to participants only when the category structure is ambiguous and that people's responses are driven by the specific set of labels they see. We present an extension of Anderson's Rational Model of Categorization that captures this effect.

  6. 40 CFR 407.74 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE CATEGORY Canned and Preserved Vegetables Subcategory § 407.74 Pretreatment standards for existing sources...

  7. 40 CFR 415.115 - New source performance standards (NSPS).

    Science.gov (United States)

    2010-07-01

    ... GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Potassium Metal Production... achieve the following new source performance standards (NSPS): There shall be no discharge of process...

  8. On the (possible range of the category house

    Directory of Open Access Journals (Sweden)

    Dilparić Branislava M.

    2014-01-01

    Full Text Available This paper reports a study whose aim was to determine whether / confirm that the category house also includes those buildings divided into (many separate dwelling units and consisted of a (very large number of storeys and whether / that they can also serve as a whole decomposed in the research on the house meronomy. The study was based on general dictionaries of the English language, picture dictionaries, dictionaries of architecture and building construction, as well as various non-dictionary sources dealing with houses, buildings, structures and/or offering examples of use of the lexeme house in its basic sense. The results of the study show that 'house' is indifferent to the observed physical features of the structures made for human habitation.

  9. Sacrality and worldmaking: new categorial perspectives

    Directory of Open Access Journals (Sweden)

    William E. Paden

    1999-01-01

    Full Text Available The category of the sacred in particular and the role of transcultural concept-formation in general have undergone an obvious crisis. For the most part, "the sacred," if not an empty label, has been linked with theologism, and transcultural concepts have been condemned for their general non-comparability and colonialist intent. The author approaches the matter of transcultural templates through an analysis of certain concepts of sacrality. With some exceptions, the discourse of sacrality has indeed been dominated by a single model, where "the sacred" became a reified noun—a substantive term for a supernatural reality, a label for the transcendent, or even an epithet for divinity, mystery, the wholly other. As such, the expression has functioned to bestow a sense of unity to the diversity of cultures, link that unity with a transcendent reality, and offer a simple way of making sense of otherwise foreign beliefs and practices by giving them a familiar, generic referent.

  10. The structure and formation of natural categories

    Science.gov (United States)

    Fisher, Douglas; Langley, Pat

    1990-01-01

    Categorization and concept formation are critical activities of intelligence. These processes and the conceptual structures that support them raise important issues at the interface of cognitive psychology and artificial intelligence. The work presumes that advances in these and other areas are best facilitated by research methodologies that reward interdisciplinary interaction. In particular, a computational model is described of concept formation and categorization that exploits a rational analysis of basic level effects by Gluck and Corter. Their work provides a clean prescription of human category preferences that is adapted to the task of concept learning. Also, their analysis was extended to account for typicality and fan effects, and speculate on how the concept formation strategies might be extended to other facets of intelligence, such as problem solving.

  11. Radiation hardness assurances categories for COTS technologies

    International Nuclear Information System (INIS)

    Hash, G.L.; Shaneyfelt, M.R.; Sexton, F.W.; Winokur, P.S.

    1997-01-01

    A comparison of the radiation tolerance of three commercial, and one radiation hardened SRAM is presented for four radiation environments. This work has shown the difficulty associated with strictly categorizing a device based solely on its radiation response, since its category depends on the specific radiation environment considered. For example, the 3.3-V Paradigm SRAM could be considered a radiation-tolerant device except for its SEU response. A more useful classification depends on the methods the manufacturer uses to ensure radiation hardness, i.e. whether specific design and process techniques have been used to harden the device. Finally, this work has shown that burned-in devices may fail functionally as much as 50% lower in total dose environments than non-burned-in devices. No burn-in effect was seen in dose-rate upset, latchup, or SEE environments. The user must ensure that total dose lot acceptance testing was performed on burned-in devices

  12. Housekeeping category corrective action unit work plan

    International Nuclear Information System (INIS)

    1996-08-01

    The purpose of this Corrective Action Unit (CAU) Work Plan is to provide a strategy to be used by the US Department of Energy Nevada Operations Office (DOE/NV), the US Department of Defense (DoD) Defense Special Weapons Agency (DSWA) (formerly the Defense Nuclear Agency), and contractor personnel for conducting corrective actions at the Nevada Test Site (NTS) and Nevada off-site locations including the Tonopah Test Range (TTR), the Project Shoal Area, and the Central Nevada Test Area. This Work Plan applies to housekeeping category CAUs already listed in the Federal Facility Agreement and Consent Order (FFACO) Appendices (FFACO, 1996) as well as newly identified Corrective Action Sites (CASs) that will follow the housekeeping process

  13. Classification versus inference learning contrasted with real-world categories.

    Science.gov (United States)

    Jones, Erin L; Ross, Brian H

    2011-07-01

    Categories are learned and used in a variety of ways, but the research focus has been on classification learning. Recent work contrasting classification with inference learning of categories found important later differences in category performance. However, theoretical accounts differ on whether this is due to an inherent difference between the tasks or to the implementation decisions. The inherent-difference explanation argues that inference learners focus on the internal structure of the categories--what each category is like--while classification learners focus on diagnostic information to predict category membership. In two experiments, using real-world categories and controlling for earlier methodological differences, inference learners learned more about what each category was like than did classification learners, as evidenced by higher performance on a novel classification test. These results suggest that there is an inherent difference between learning new categories by classifying an item versus inferring a feature.

  14. The role of grammatical category information in spoken word retrieval.

    Science.gov (United States)

    Duràn, Carolina Palma; Pillon, Agnesa

    2011-01-01

    We investigated the role of lexical syntactic information such as grammatical gender and category in spoken word retrieval processes by using a blocking paradigm in picture and written word naming experiments. In Experiments 1, 3, and 4, we found that the naming of target words (nouns) from pictures or written words was faster when these target words were named within a list where only words from the same grammatical category had to be produced (homogeneous category list: all nouns) than when they had to be produced within a list comprising also words from another grammatical category (heterogeneous category list: nouns and verbs). On the other hand, we detected no significant facilitation effect when the target words had to be named within a homogeneous gender list (all masculine nouns) compared to a heterogeneous gender list (both masculine and feminine nouns). In Experiment 2, using the same blocking paradigm by manipulating the semantic category of the items, we found that naming latencies were significantly slower in the semantic category homogeneous in comparison with the semantic category heterogeneous condition. Thus semantic category homogeneity caused an interference, not a facilitation effect like grammatical category homogeneity. Finally, in Experiment 5, nouns in the heterogeneous category condition had to be named just after a verb (category-switching position) or a noun (same-category position). We found a facilitation effect of category homogeneity but no significant effect of position, which showed that the effect of category homogeneity found in Experiments 1, 3, and 4 was not due to a cost of switching between grammatical categories in the heterogeneous grammatical category list. These findings supported the hypothesis that grammatical category information impacts word retrieval processes in speech production, even when words are to be produced in isolation. They are discussed within the context of extant theories of lexical production.

  15. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers

    Directory of Open Access Journals (Sweden)

    Mahmood DJH

    2016-02-01

    Full Text Available Deyar Jallal Hadi Mahmood, Ewa H Linderoth, Ann Wennerberg, Per Vult Von Steyern Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden Aim: To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP fixed dental prostheses (FDPs with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP cores. Materials and methods: A total of 110 three-unit Y-TZP FDP cores with one intermediate pontic were made. The FDP cores in groups 1–7 were made with a split-file design, veneered with manually built-up porcelain, computer-aided design-on veneers, and over-pressed veneers. Groups 8–11 consisted of FDPs with a state-of-the-art design, veneered with manually built-up porcelain. All the FDP cores were subjected to simulated aging and finally loaded to fracture. Results: There was a significant difference (P<0.05 between the core designs, but not between the different types of Y-TZP materials. The split-file designs with VITABLOCS® (1,806±165 N and e.max® ZirPress (1,854±115 N and the state-of-the-art design with VITA VM® 9 (1,849±150 N demonstrated the highest mean fracture values. Conclusion: The shape of a split-file designed all-ceramic reconstruction calls for a different dimension protocol, compared to traditionally shaped ones, as the split-file design leads to sharp approximal indentations acting as fractural impressions, thus decreasing the overall strength. The design of a framework is a crucial factor for the load bearing capacity of an all-ceramic FDP. The state-of-the-art design is preferable since the split-file designed cores call for a cross-sectional connector area at least 42% larger, to have the same load bearing capacity as the state-of-the-art designed

  16. Investigating cross-category brand loyalty behavior in FMCG

    DEFF Research Database (Denmark)

    Boztug, Yasemin; Hildebrandt, Lutz; Silberhorn, Nadja

    category depend on purchases in other categories. The aspect of cross-category related brand loyalty has been somewhat neglected so far. We concentrate on cross-category relationships of strong national brands and on how customers' brand choice decisions are related across several product categories.......In competitive markets, customer retention is more efficient than trying to attract new customers. Brand loyalty is an intrinsic commitment to repeatedly purchase a particular brand. But most analyses have been conducted in one specific category only. It has been shown that product purchases in one...

  17. 利用响应面法研究微孔处理杨木单板的胶合性能%Bonding Properties of Poplar Veneer Punched with Micro-holes by Response Surface Methodology

    Institute of Scientific and Technical Information of China (English)

    唐忠荣; 黄健; 戴玉玲; 丰江拓

    2015-01-01

    利用响应面法分析研究了经微孔处理后的杨木单板的胶合性能。通过对杨木单板进行微孔处理,可使胶黏剂通过微孔渗入单板体内,增加杨木单板的本体强度,同时也可使相邻胶层透过微孔形成一体而增加单板的胶合强度等,以期制造出一种高性能的地板基材。结果表明:在试验范围内,随微孔孔径增大,孔距减小和施胶量的增加,其胶合强度增加;随热压压力增加,胶合强度先增强,当压力超过0.8 MPa,胶合强度反而降低。%We studied the bonding properties of poplar veneer punched with micro-holes by using response surface experiment. The permeability of poplar veneer increased after micro-hole punching.The adhesive could penetrate into the veneer through these micro holes, and the poplar veneer was strengthened.Through micro holes, the neighboring glue lines formed a whole to increase the bonding strength of veneers.Expecting to produce a high performance floor material.The bonding strength of poplar plywood increased with the increasing of micro-hole diameter,resin content , and the decreasing of holes distance.With the increasing of hot pressing pressure, the bonding strength was improved firstly, however, it declined when the pressure exceeded 0.8 MPa.

  18. Ad Hoc Categories and False Memories: Memory Illusions for Categories Created On-The-Spot

    Science.gov (United States)

    Soro, Jerônimo C.; Ferreira, Mário B.; Semin, Gün R.; Mata, André; Carneiro, Paula

    2017-01-01

    Three experiments were designed to test whether experimentally created ad hoc associative networks evoke false memories. We used the DRM (Deese, Roediger, McDermott) paradigm with lists of ad hoc categories composed of exemplars aggregated toward specific goals (e.g., going for a picnic) that do not share any consistent set of features. Experiment…

  19. Category Specificity in Normal Episodic Learning: Applications to Object Recognition and Category-Specific Agnosia

    Science.gov (United States)

    Bukach, Cindy M.; Bub, Daniel N.; Masson, Michael E. J.; Lindsay, D. Stephen

    2004-01-01

    Studies of patients with category-specific agnosia (CSA) have given rise to multiple theories of object recognition, most of which assume the existence of a stable, abstract semantic memory system. We applied an episodic view of memory to questions raised by CSA in a series of studies examining normal observers' recall of newly learned attributes…

  20. Category Formation in Autism: Can Individuals with Autism Form Categories and Prototypes of Dot Patterns?

    Science.gov (United States)

    Gastgeb, Holly Zajac; Dundas, Eva M.; Minshew, Nancy J.; Strauss, Mark S.

    2012-01-01

    There is a growing amount of evidence suggesting that individuals with autism have difficulty with categorization. One basic cognitive ability that may underlie this difficulty is the ability to abstract a prototype. The current study examined prototype and category formation with dot patterns in high-functioning adults with autism and matched…

  1. [Wear intensity and surface roughness of microhybrid composite and ceramic occlusal veneers on premolars after the thermocycling and cyclic mechanical loading tests].

    Science.gov (United States)

    Zhang, H Y; Jiang, T; Cheng, M X; Zhang, Y W

    2018-02-18

    To evaluate the wear intensity and surface roughness of occlusal veneers on premolars made of microhybrid composite resin or two kinds of ceramics in vitro after the thermocycling and cyclic mechanical loading tests. In the study,24 fresh extracted human premolars without root canal treatment were prepared (cusps reduction of 1.5 mm in thickness to simulate middle to severe tooth wear, the inclinations of cusps were 20°). The prepared teeth were restored with occlusal veneers made of three different materials: microhybrid composite, heat-pressed lithium disilicate ceramic and computer-aided design/computer-aided manufacturing (CAD/CAM) lithium disilicate ceramic in the thickness of 1.5 mm. The occlusal veneers were cemented with resin cement. The specimens were fatigued using the thermocycling and cyclic mechanical loading tests after being stored in water for 72 h. The wear of specimens was measured using gypsum replicas and 3D laser scanner before and after the thermocycling and cyclic mechanical loading tests and the mean lost distance (mm) was used to indicate the level of wear. The surfaces of occlusal contact area were observed and the surface roughness was recorded using 3D laser scanning confocal microscope before and after the fatigue test. Differences between the groups were compared using ONE-way ANOVA(Pcomposite group, heat-pressed lithium disilicate ceramic group, and CAD/CAM lithium disilicate ceramic group was (-0.13±0.03) mm, (-0.05±0.01) mm and (-0.05±0.01) mm, the wear of microhybrid composite was significantly higher than the two ceramic groups(Pcomposite was significantly higher than the two ceramic groups(Pcomposite(P=0.005) and CAD/CAM lithium disilicate ceramic (P=0.010). From the view of wear speed, microhybrid composite was significantly higher than the two kinds of ceramics, but it was similar to enamel when the opposing tooth was natural. The surface roughness before the themocycling and cyclic mechanical loading test of microhybrid

  2. Correlation of the verb transitivity with other grammatical categories

    OpenAIRE

    LIUBCHENKO TATIANA VIKTOROVNA

    2016-01-01

    The correlation of the verb transitivity with other categories, including voice and aspect is specified in investigation. The article also deals with interpretation of categories “voice” and “diathesis” in linguistics.

  3. School based assessment module for invasion games category in ...

    African Journals Online (AJOL)

    School based assessment module for invasion games category in physical education. ... This study identify the level of basic skills of invasion games category when using School Based Assessment Module. ... AJOL African Journals Online.

  4. AMUC: Associated Motion capture User Categories.

    Science.gov (United States)

    Norman, Sally Jane; Lawson, Sian E M; Olivier, Patrick; Watson, Paul; Chan, Anita M-A; Dade-Robertson, Martyn; Dunphy, Paul; Green, Dave; Hiden, Hugo; Hook, Jonathan; Jackson, Daniel G

    2009-07-13

    The AMUC (Associated Motion capture User Categories) project consisted of building a prototype sketch retrieval client for exploring motion capture archives. High-dimensional datasets reflect the dynamic process of motion capture and comprise high-rate sampled data of a performer's joint angles; in response to multiple query criteria, these data can potentially yield different kinds of information. The AMUC prototype harnesses graphic input via an electronic tablet as a query mechanism, time and position signals obtained from the sketch being mapped to the properties of data streams stored in the motion capture repository. As well as proposing a pragmatic solution for exploring motion capture datasets, the project demonstrates the conceptual value of iterative prototyping in innovative interdisciplinary design. The AMUC team was composed of live performance practitioners and theorists conversant with a variety of movement techniques, bioengineers who recorded and processed motion data for integration into the retrieval tool, and computer scientists who designed and implemented the retrieval system and server architecture, scoped for Grid-based applications. Creative input on information system design and navigation, and digital image processing, underpinned implementation of the prototype, which has undergone preliminary trials with diverse users, allowing identification of rich potential development areas.

  5. Health and morality: two conceptually distinct categories?

    Science.gov (United States)

    Tengland, Per-Anders

    2012-03-01

    When seeing immoral actions, criminal or not, we sometimes deem the people who perform them unhealthy. This is especially so if the actions are of a serious nature, e.g. involving murder, assault, or rape. We turn our moral evaluation into an evaluation about health and illness. This tendency is partly supported by some diagnoses found in the DMS-IV, such as Antisocial personality disorder, and the ICD-10, such as Dissocial personality disorder. The aim of the paper is to answer the question: How analytically sound is the inclusion of morality into a theory of health? The holistic theory of Lennart Nordenfelt is used as a starting point, and it is used as an example of a theory where morality and health are conceptually distinct categories. Several versions of a pluralistic holistic theory are then discussed in order to see if, and if so, how, morality can be conceptually related to health. It is concluded that moral abilities (and dispositions) can be seen as being part of the individual's health. It is harder to incorporate moral virtues and moral actions into such a theory. However, if immoral actions "cluster" in an individual, and are of a severe kind, causing serious harm to other people, it is more likely that the person, for those reasons only, be deemed unhealthy.

  6. Licensing system for primary category radioactive installations

    International Nuclear Information System (INIS)

    Ramirez Riquelme, Angelica Beatriz

    1997-01-01

    The development of a licensing system for primary category radioactive installations is described, which aims to satisfy the needs of the Chilean Nuclear Energy Commission's Department of Nuclear and Radiological Safety, particularly the sections for Licensing Outside Radioactive Installations and Safety Control. This system involves the identification, control and inspection of the installations, their personnel and connected activities, for the purpose of protecting the population's health and the environment. Following the basic cycle methodology, a systems analysis and engineering stage was prepared, establishing the functions of the system's elements and defining the requirements, based on interviews with the users. This stage was followed by the design stage, focusing on the data structure, the software architecture and the procedural detail. The codification stage followed, which translated the design into legible machine-readable format. In the testing stage, the entries that were defined were proven to produce the expected data. Finally and operational and maintenance stage was developed, when the system was installed and put to use. All the above generated a useful system for the Licensing section of the Department of Nuclear and Radiological Safety, since it provides faster and easier access to information. A project is described that introduces new development tools in the Computer department following standards established by the C.CH.E.N. (author)

  7. Identifying demand effects in a large network of product categories

    NARCIS (Netherlands)

    Gelper, S.E.C.; Wilms, I.; Croux, C.

    2016-01-01

    Planning marketing mix strategies requires retailers to understand within- as well as cross-category demand effects. Most retailers carry products in a large variety of categories, leading to a high number of such demand effects to be estimated. At the same time, we do not expect cross-category

  8. A note on thick subcategories of stable derived categories

    OpenAIRE

    Krause, Henning; Stevenson, Greg

    2013-01-01

    For an exact category having enough projective objects, we establish a bijection between thick subcategories containing the projective objects and thick subcategories of the stable derived category. Using this bijection, we classify thick subcategories of finitely generated modules over strict local complete intersections and produce generators for the category of coherent sheaves on a separated Noetherian scheme with an ample family of line bundles.

  9. 14 CFR 61.159 - Aeronautical experience: Airplane category rating.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience: Airplane category... Transport Pilots § 61.159 Aeronautical experience: Airplane category rating. (a) Except as provided in... certificate with an airplane category and class rating must have at least 1,500 hours of total time as a pilot...

  10. 47 CFR 36.126 - Circuit equipment-Category 4.

    Science.gov (United States)

    2010-10-01

    ... separating property associated with special services, circuit equipment included in Categories 4.12 (other... Equipment Excluding Wideband—Category 4.13—The cost of Circuit Equipment associated with exchange line plant... 47 Telecommunication 2 2010-10-01 2010-10-01 false Circuit equipment-Category 4. 36.126 Section 36...

  11. Quasi-coherent Hecke category and Demazure descent

    DEFF Research Database (Denmark)

    Arkhipov, Sergey; Kanstrup, Tina

    2015-01-01

    Let G be a reductive algebraic group with a Borel subgroup B. We define the quasi-coherent Hecke category for the pair (G,B). For any regular Noetherian G- scheme X we construct a monoidal action of the Hecke category on the derived category of B-equivariant quasi-coherent sheaves on X. Using the...

  12. An Analysis of Category Management of Service Contracts

    Science.gov (United States)

    2017-12-01

    comprised of four steps to guide future category management teams in analyzing data and applying Category Management principles through the use of...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA MBA PROFESSIONAL REPORT AN ANALYSIS OF CATEGORY MANAGEMENT OF SERVICE CONTRACTS December 2017...Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project

  13. Prior knowledge of category size impacts visual search.

    Science.gov (United States)

    Wu, Rachel; McGee, Brianna; Echiverri, Chelsea; Zinszer, Benjamin D

    2018-03-30

    Prior research has shown that category search can be similar to one-item search (as measured by the N2pc ERP marker of attentional selection) for highly familiar, smaller categories (e.g., letters and numbers) because the finite set of items in a category can be grouped into one unit to guide search. Other studies have shown that larger, more broadly defined categories (e.g., healthy food) also can elicit N2pc components during category search, but the amplitude of these components is typically attenuated. Two experiments investigated whether the perceived size of a familiar category impacts category and exemplar search. We presented participants with 16 familiar company logos: 8 from a smaller category (social media companies) and 8 from a larger category (entertainment/recreation manufacturing companies). The ERP results from Experiment 1 revealed that, in a two-item search array, search was more efficient for the smaller category of logos compared to the larger category. In a four-item search array (Experiment 2), where two of the four items were placeholders, search was largely similar between the category types, but there was more attentional capture by nontarget members from the same category as the target for smaller rather than larger categories. These results support a growing literature on how prior knowledge of categories affects attentional selection and capture during visual search. We discuss the implications of these findings in relation to assessing cognitive abilities across the lifespan, given that prior knowledge typically increases with age. © 2018 Society for Psychophysiological Research.

  14. Predicting Success Study Using Students GPA Category

    Directory of Open Access Journals (Sweden)

    Awan Setiawan

    2015-07-01

    Full Text Available Abstract. Maintaining student graduation rates are the main tasks of a University. High rates of student graduation and the quality of graduates is a success indicator of a university, which will have an impact on public confidence as stakeholders of higher education and the National Accreditation Board as a regulator (government. Making predictions of student graduation and determine the factors that hinders will be a valuable input for University. Data mining system facilitates the University to create the segmentation of students’ performance and prediction of their graduation. Segmentation of student by their performance can be classified in a quadrant chart is divided into 4 segments based on grade point average and the growth rate of students performance index per semester. Standard methodology in data mining i.e CRISP-DM (Cross Industry Standard Procedure for Data Mining will be implemented in this research. Making predictions, graduation can be done through the modeling process by utilizing the college database. Some algorithms such as C5, C & R Tree, CHAID, and Logistic Regression tested in order to find the best model. This research utilizes student performance data for several classes. Parameters used in addition to GPA also included the master's students data are expected to build the student profile data. The outcome of the study is the student category based on their study performance and prediction of graduation. Based on this prediction, the  university may recommend actions to be taken to improve the student  achievement index and graduation rates.Keywords: graduation, segmentation, quadrant GPA, data mining, modeling algorithms

  15. Predicting Success Study Using Students GPA Category

    Directory of Open Access Journals (Sweden)

    Awan Setiawan

    2015-06-01

    Full Text Available Abstract. Maintaining student graduation rates are the main tasks of a University. High rates of student graduation and the quality of graduates is a success indicator of a university, which will have an impact on public confidence as stakeholders of higher education and the National Accreditation Board as a regulator (government. Making predictions of student graduation and determine the factors that hinders will be a valuable input for University. Data mining system facilitates the University to create the segmentation of students’ performance and prediction of their graduation. Segmentation of student by their performance can be classified in a quadrant chart is divided into 4 segments based on grade point average and the growth rate of students performance index per semester. Standard methodology in data mining i.e CRISP-DM (Cross Industry Standard Procedure for Data Mining will be implemented in this research. Making predictions, graduation can be done through the modeling process by utilizing the college database. Some algorithms such as C5, C & R Tree, CHAID, and Logistic Regression tested in order to find the best model. This research utilizes student performance data for several classes. Parameters used in addition to GPA also included the master's students data are expected to build the student profile data. The outcome of the study is the student category based on their study performance and prediction of graduation. Based on this prediction, the university may recommend actions to be taken to improve the student achievement index and graduation rates. Keywords: graduation, segmentation, quadrant GPA, data mining, modeling algorithms

  16. EDUCATIONAL EVENT AS THE PEDAGOGICAL CATEGORY

    Directory of Open Access Journals (Sweden)

    Victor V. Lobanov

    2015-01-01

    Full Text Available The aim of the investigation is to reveal the essence of the educational event as a pedagogical category. The reason to study the issue is the methodological generality of the term that came into pedagogical everyday life, but which semantic content is still not clear enough. Methods. The methods involve a theoretical analysis of the philosophical and pedagogical literature on the study, the categorical analysis, surveys of students and teachers. Results. The concept content of «event» is looked upon in both historical scholarship and pedagogy, «educational event» is analyzed in unity with the «educational situation» and «educational process». The attitude of students and teachers to educational events was clarified through the surveys; emotional and rational responses of the respondents were differentiated and the peculiarities of events organization in the education system were classified. While teachers and students are considered as subjects of educational events, their goals are delineated. Scientific novelty. The author's own definition of is given. Educational event is defined as a specially organized and unique pedagogical fact limited, but not rigidly determined by the educational situation, and capable of changing the educational process going beyond the boundaries of its conformism. The formulation above is the result of analysis how the concepts of «event», «situation» and «process» may interact in pedagogical discourse. Practical significance. The results can be used while designing the educational programs and projects, as well as in the development of academic courses of innovative pedagogy. 

  17. Preschool Children Differentiation According to the Lingua- Grammatical Categories Development

    Directory of Open Access Journals (Sweden)

    Z. V. Polivara

    2012-01-01

    Full Text Available The parallel existence of languages and cultures brings forward the necessity of studying this linguistic phenomenon and designing special methods of speech development for the bilingual children. The particular attention should be given to the preschool age, for according to A. A. Leontyev’s study, the parallel acquiring of two languages often results in insufficient development of socio-linguistic speech standards. The research is devoted to the phenomenon of the two language systems coexistence in a bilingual person’s consciousness, both of them functioning and encoding the same subjects and phenomena. The peculiarities of language interference are described with the reference to the Russian-Tatar bilingual environment. The author believes that the bilingual interference problems are not caused by the phonetic and grammar system differences of the two languages. To find out the potential source of inter-language transition and interrelations between the native and non-native languages, it is necessary to identify the cognitive, neurolinguistic and psycho-linguistic aspects. Therefore, the regional phenomenon of mass bilingualism among the Tatar population is examined by the author in the framework of the psycho-linguistic and cognitive approaches. The paper presents the model of the lexical and grammar categories formation based on differentiated preschool teaching of the bilingual children. The proposed model makes it possible to overcome the limited viewpoint on the general speech dysfunctions, as well as the specifics of lexical and grammar categories development. It can be used for the further development of educational programs in psycho-linguistics, ethno-linguistics, onto-linguistics, cognitive linguistics, social-linguistics, contrastive linguistics and the language theory by means of extending the teaching course content. 

  18. Risk as economic category: systematics scientific approach and refinement contents

    Directory of Open Access Journals (Sweden)

    V.G. Vygovskyy

    2015-03-01

    Full Text Available The paper studies the categorical-conceptual apparatus of risk and its refinement based on a critical analysis of existing systematic scientific approaches. Determined that in the refinement of the economic nature of the risk of a number of controversial issues: the definition of the objective or subjective nature of risk; matching of concepts such as «risk», «danger», «loss», «probability of loss»; definition of negative or positive consequences of risk; identification of risk with its consequences, or source of origin, which makes the relevance of research topics. As a result of scientific research has been refined interpretation of risk as an economic category, the characteristics of the company associated with the probability of unforeseen situations that may lead to negative and positive impacts, assessment of which requires the development of alternatives for management decisions. Clarification of the definition focuses on the possibility (probability of a favorable (unfavorable events which require certain corrective action management unit of the enterprise. The author emphasizes the mandatory features of the category of «risk», in particular: the concept of risk is always associated with the uncertainty of the future; event occurring has implications for the enterprise (both negative and positive; consequences for necessitates the development of a number of alternative solutions to the possible elimination of the negative consequences of risky events; risk – a mandatory attribute of modern management (its value is enhanced in terms of market conditions; subject to risk assessment and management by the company. Dedicated and updated features contribute to the clarification of the nature of the economic risk and categorical conceptual apparatus of risk management.

  19. Sol-gel dip coating of yttria-stabilized tetragonal zirconia dental ceramic by aluminosilicate nanocomposite as a novel technique to improve the bonding of veneering porcelain.

    Science.gov (United States)

    Madani, Azamsadat; Nakhaei, Mohammadreza; Karami, Parisa; Rajabzadeh, Ghadir; Salehi, Sahar; Bagheri, Hossein

    2016-01-01

    The aim of this in vitro study was to evaluate the effect of silica and aluminosilicate nanocomposite coating of zirconia-based dental ceramic by a sol-gel dip-coating technique on the bond strength of veneering porcelain to the yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) in vitro. Thirty Y-TZP blocks (10 mm ×10 mm ×3 mm) were prepared and were assigned to four experimental groups (n=10/group): C, without any further surface treatment as the control group; S, sandblasted using 110 μm alumina powder; Si, silica sol dip coating + calcination; and Si/Al, aluminosilicate sol dip coating + calcination. After preparing Y-TZP samples, a 3 mm thick layer of the recommended porcelain was fired on the coated Y-TZP surface. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis were used to characterize the coating and the nature of the bonding between the coating and zirconia. To examine the zirconia-porcelain bond strength, a microtensile bond strength (μTBS) approach was chosen. FT-IR study showed the formation of silica and aluminosilicate materials. XRD pattern showed the formation of new phases consisting of Si, Al, and Zr in coated samples. SEM showed the formation of a uniform coating on Y-TZP samples. Maximum μTBS values were obtained in aluminosilicate samples, which were significantly increased compared to control and sandblasted groups (P=0.013 and Pcoating can be considered as a convenient, less expensive reliable method for improving the bond strength between dental Y-TZP ceramics and veneering porcelain.

  20. Shear bond strength of veneering porcelain to zirconia: Effect of surface treatment by CNC-milling and composite layer deposition on zirconia.

    Science.gov (United States)

    Santos, R L P; Silva, F S; Nascimento, R M; Souza, J C M; Motta, F V; Carvalho, O; Henriques, B

    2016-07-01

    The purpose of this study was to evaluate the shear bond strength of veneering feldspathic porcelain to zirconia substrates modified by CNC-milling process or by coating zirconia with a composite interlayer. Four types of zirconia-porcelain interface configurations were tested: RZ - porcelain bonded to rough zirconia substrate (n=16); PZ - porcelain bonded to zirconia substrate with surface holes (n=16); RZI - application of a composite interlayer between the veneering porcelain and the rough zirconia substrate (n=16); PZI - application of a composite interlayer between the porcelain and the zirconia substrate treated by CNC-milling (n=16). The composite interlayer was composed of zirconia particles reinforced porcelain (30%, vol%). The mechanical properties of the ceramic composite have been determined. The shear bond strength test was performed at 0.5mm/min using a universal testing machine. The interfaces of fractured and untested specimens were examined by FEG-SEM/EDS. Data was analyzed with Shapiro-Wilk test to test the assumption of normality. The one-way ANOVA followed by Tukey HSD multiple comparison test was used to compare shear bond strength results (α=0.05). The shear bond strength of PZ (100±15MPa) and RZI (96±11MPa) specimens were higher than that recorded for RZ (control group) specimens (89±15MPa), although not significantly (p>0.05). The highest shear bond strength values were recorded for PZI specimens (138±19MPa), yielding a significant improvement of 55% relative to RZ specimens (p<0.05). This study shows that it is possible to highly enhance the zirconia-porcelain bond strength - even by ~55% - by combining surface holes in zirconia frameworks and the application of a proper ceramic composite interlayer. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Evaluation of Bond Strength between Grooved Titanium Alloy Implant Abutments and Provisional Veneering Materials after Surface Treatment of the Abutments: An In vitro Study.

    Science.gov (United States)

    Venkat, Gowtham; Krishnan, Murugesan; Srinivasan, Suganya; Balasubramanian, Muthukumar

    2017-01-01

    Titanium has become the material of choice with greater applications in dental implants. The success of the dental implant does not only depend on the integration of the implant to the bone but also on the function and longevity of the superstructure. The clinical condition that demands long-term interim prosthesis is challenging owing to the decreased bond between the abutment and the veneering material. Hence, various surface treatments are done on the abutments to increase the bond strength. This study aimed to evaluate the bond strength between the abutment and the provisional veneering materials by surface treatments such as acid etching, laser etching, and sand blasting of the abutment. Forty titanium alloy abutments of 3 mm diameter and 11 mm height were grouped into four groups with ten samples. Groups A, B, C, and D are untreated abutments, sand blasted with 110 μm aluminum particles, etched with 1% hydrofluoric acid and 30% nitric acid, and laser etched with Nd: YAG laser, respectively. Provisional crowns were fabricated with bis-acrylic resin and cemented with noneugenol temporary luting cement. The shear bond strength was measured in universal testing machine using modified Shell-Nielsen shear test after the cemented samples were stored in water at 25°C for 24 h. Load was applied at a constant cross head speed of 5 mm/min until a sudden decrease in resistance indicative of bond failure was observed. The corresponding force values were recorded, and statistical analysis was done using one-way ANOVA and Newman-Keuls post hoc test. The laser-etched samples showed higher bond strength. Among the three surface treatments, laser etching showed the highest bond strength between titanium alloy implant abutment and provisional restorations. The sand-blasted surfaces demonstrated a significant difference in bond strength compared to laser-etched surfaces. The results of this study confirmed that a combination of surface treatments and bond agents enhances the

  2. Comparative Evaluation of Effects of Laser Modalities on Shear Bond Strengths of Veneering Porcelains to Laser Sintered Substructures: An In Vitro Study.

    Science.gov (United States)

    Gorler, Oguzhan; Saygin, Aysegul Goze

    2017-06-01

    Laser modalities and direct metal laser sintering (DMLS) have a potential to enhance micromechanical bonding between dental super- and infrastructures. However, the effect of different manufacturing methods on the metal-ceramic bond strength needs further evaluation. We investigated the effect of surface treatment with Er:YAG, Nd:YAG, and Ho:YAG lasers on the shear bond strength (SBS) of high-fusion dental porcelains (Vita and G-Ceram) to infrastructures prepared with DMLS in vitro settings. Study specimens (n = 128) were randomly divided into study subsets (n = 8), considering treatment types applied on the surface of infrastructures, including sandblasting and selected laser modalities; infrastructure types as direct laser sintered (DLS) and Ni-Cr based; and superstructure porcelains as Vita and G-Ceram. The SBS test was performed to assess the effectiveness of surface modifications that were also examined with a stereo microscope. Considering laser procedure types, the highest SBS values were obtained by Er:YAG laser, followed by, with a decreasing efficiency, Ho:YAG laser and sandblasting procedures, and Nd:YAG laser procedure (p laser decreases the bonding of Vita and G-Ceram in all the infrastructures compared with sandblasting. Considering porcelains, the highest SBS values were obtained by Vita (p laser procedures caused surface irregularities as revealed by the stereo microscopic examination. In current experimental settings, Er:YAG laser applied to DLS infrastructure veneered with Vita porcelain increases bonding strength more distinctly, and Nd:YAG laser applied to Ni-Cr-based infrastructure veneered with G-Ceram porcelain alters bonding strength unfavorably.

  3. Prescriptions for category D and X drugs during pregnancy in Taiwan: a population-based study.

    Science.gov (United States)

    Kao, Li-Ting; Chen, Yi-Hua; Lin, Herng-Ching; Chung, Shiu-Dong

    2014-10-01

    This study aimed to investigate the most prescribed medications and principle diagnoses for category D and X drugs during pregnancy using a population-based dataset in Taiwan. The data for the present study were sourced from the Taiwan Longitudinal Health Insurance Database 2000. We selected 14 125 women who had live singleton births between 1 January 2009 and 31 December 2011. In total, 217 226 prescriptions prescribed to these pregnant women were identified. Of the total 217 226 prescriptions, 1.1% were category D or X drugs; in the first, second, and third trimesters of pregnancy, 1.8%, 0.7%, and 0.5% of prescriptions were category D or X drugs, respectively. Progestins (15.3%) and propylthiouracil (10.7%) were the two most frequently prescribed category D or X drugs during pregnancy. In particular, progestins (20.4%) and estrogens (15.6%) were the most frequently prescribed category D or X drug in the first trimester of pregnancy. Propylthiouracil was the most prescribed category D or X drug in the second (20.3%) and third trimesters (23.1%) of pregnancy, respectively. The most common principal diagnosis during pregnancy was "disorders of menstruation and other abnormal bleeding from the female genital tract" (22% of all principal diagnoses for prescribing category D and X drugs). Our study found that the physicians obviously reduced the use of category D and X drugs for women after becoming aware that they were pregnant. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Chromatic Perceptual Learning but No Category Effects without Linguistic Input.

    Science.gov (United States)

    Grandison, Alexandra; Sowden, Paul T; Drivonikou, Vicky G; Notman, Leslie A; Alexander, Iona; Davies, Ian R L

    2016-01-01

    Perceptual learning involves an improvement in perceptual judgment with practice, which is often specific to stimulus or task factors. Perceptual learning has been shown on a range of visual tasks but very little research has explored chromatic perceptual learning. Here, we use two low level perceptual threshold tasks and a supra-threshold target detection task to assess chromatic perceptual learning and category effects. Experiment 1 investigates whether chromatic thresholds reduce as a result of training and at what level of analysis learning effects occur. Experiment 2 explores the effect of category training on chromatic thresholds, whether training of this nature is category specific and whether it can induce categorical responding. Experiment 3 investigates the effect of category training on a higher level, lateralized target detection task, previously found to be sensitive to category effects. The findings indicate that performance on a perceptual threshold task improves following training but improvements do not transfer across retinal location or hue. Therefore, chromatic perceptual learning is category specific and can occur at relatively early stages of visual analysis. Additionally, category training does not induce category effects on a low level perceptual threshold task, as indicated by comparable discrimination thresholds at the newly learned hue boundary and adjacent test points. However, category training does induce emerging category effects on a supra-threshold target detection task. Whilst chromatic perceptual learning is possible, learnt category effects appear to be a product of left hemisphere processing, and may require the input of higher level linguistic coding processes in order to manifest.

  5. An introduction to the language of category theory

    CERN Document Server

    Roman, Steven

    2017-01-01

    This textbook provides an introduction to elementary category theory, with the aim of making what can be a confusing and sometimes overwhelming subject more accessible. In writing about this challenging subject, the author has brought to bear all of the experience he has gained in authoring over 30 books in university-level mathematics. The goal of this book is to present the five major ideas of category theory: categories, functors, natural transformations, universality, and adjoints in as friendly and relaxed a manner as possible while at the same time not sacrificing rigor. These topics are developed in a straightforward, step-by-step manner and are accompanied by numerous examples and exercises, most of which are drawn from abstract algebra. The first chapter of the book introduces the definitions of category and functor and discusses diagrams, duality, initial and terminal objects, special types of morphisms, and some special types of categories, particularly comma categories and hom-set categories. Chap...

  6. What drives consumer involvement? The relative impact of product category and product attribute

    DEFF Research Database (Denmark)

    de Barcellos, Marcia Dutra; Kügler, Jens Oliver; Scholderer, Joachim

    2009-01-01

    , foods, household appliances, alcoholic beverages) and on two involvement dimensions (interest and importance). The results indicate that in three of the four super-categories the predominant source of variation in product involvement were the attributes of the products, not the product category...... they belong to. Only for foods, the traditional conceptualisation of involvement held. The findings suggest that parts of previous research on involvement may have to be re-interpreted and that future research should adopt more complex conceptualisations of involvement. From a managerial point of view...

  7. None of the above: A Bayesian account of the detection of novel categories.

    Science.gov (United States)

    Navarro, Daniel J; Kemp, Charles

    2017-10-01

    Every time we encounter a new object, action, or event, there is some chance that we will need to assign it to a novel category. We describe and evaluate a class of probabilistic models that detect when an object belongs to a category that has not previously been encountered. The models incorporate a prior distribution that is influenced by the distribution of previous objects among categories, and we present 2 experiments that demonstrate that people are also sensitive to this distributional information. Two additional experiments confirm that distributional information is combined with similarity when both sources of information are available. We compare our approach to previous models of unsupervised categorization and to several heuristic-based models, and find that a hierarchical Bayesian approach provides the best account of our data. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. A Bulk Microphysics Parameterization with Multiple Ice Precipitation Categories.

    Science.gov (United States)

    Straka, Jerry M.; Mansell, Edward R.

    2005-04-01

    A single-moment bulk microphysics scheme with multiple ice precipitation categories is described. It has 2 liquid hydrometeor categories (cloud droplets and rain) and 10 ice categories that are characterized by habit, size, and density—two ice crystal habits (column and plate), rimed cloud ice, snow (ice crystal aggregates), three categories of graupel with different densities and intercepts, frozen drops, small hail, and large hail. The concept of riming history is implemented for conversions among the graupel and frozen drops categories. The multiple precipitation ice categories allow a range of particle densities and fall velocities for simulating a variety of convective storms with minimal parameter tuning. The scheme is applied to two cases—an idealized continental multicell storm that demonstrates the ice precipitation process, and a small Florida maritime storm in which the warm rain process is important.

  9. Social categories as markers of intrinsic interpersonal obligations.

    Science.gov (United States)

    Rhodes, Marjorie; Chalik, Lisa

    2013-06-01

    Social categorization is an early-developing feature of human social cognition, yet the role that social categories play in children's understanding of and predictions about human behavior has been unclear. In the studies reported here, we tested whether a foundational functional role of social categories is to mark people as intrinsically obligated to one another (e.g., obligated to protect rather than harm). In three studies, children (aged 3-9, N = 124) viewed only within-category harm as violating intrinsic obligations; in contrast, they viewed between-category harm as violating extrinsic obligations defined by explicit rules. These data indicate that children view social categories as marking patterns of intrinsic interpersonal obligations, suggesting that a key function of social categories is to support inferences about how people will relate to members of their own and other groups.

  10. Category mistakes: A barrier to effective environmental management.

    Science.gov (United States)

    Wallace, Ken J; Jago, Mark

    2017-09-01

    How entities, the things that exist, are defined and categorised affects all aspects of environmental management including technical descriptions, quantitative analyses, participatory processes, planning, and decisions. Consequently, ambiguous definitions and wrongly assigning entities to categories, referred to as category mistakes, are barriers to effective management. Confusion caused by treating the term 'biodiversity' variously as the property of an area, the biota of an area, and a preferred end state (a value) - quite different categories of entities - is one example. To overcome such difficulties, we develop and define four entity categories - elements, processes, properties, and values - and two derived categories - states and systems. We argue that adoption of these categories and definitions will significantly improve environmental communication and analysis, and thus strengthen planning and decision-making. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Categorial compositionality: a category theory explanation for the systematicity of human cognition.

    Directory of Open Access Journals (Sweden)

    Steven Phillips

    Full Text Available Classical and Connectionist theories of cognitive architecture seek to explain systematicity (i.e., the property of human cognition whereby cognitive capacity comes in groups of related behaviours as a consequence of syntactically and functionally compositional representations, respectively. However, both theories depend on ad hoc assumptions to exclude specific instances of these forms of compositionality (e.g. grammars, networks that do not account for systematicity. By analogy with the Ptolemaic (i.e. geocentric theory of planetary motion, although either theory can be made to be consistent with the data, both nonetheless fail to fully explain it. Category theory, a branch of mathematics, provides an alternative explanation based on the formal concept of adjunction, which relates a pair of structure-preserving maps, called functors. A functor generalizes the notion of a map between representational states to include a map between state transformations (or processes. In a formal sense, systematicity is a necessary consequence of a higher-order theory of cognitive architecture, in contrast to the first-order theories derived from Classicism or Connectionism. Category theory offers a re-conceptualization for cognitive science, analogous to the one that Copernicus provided for astronomy, where representational states are no longer the center of the cognitive universe--replaced by the relationships between the maps that transform them.

  12. Categorial compositionality: a category theory explanation for the systematicity of human cognition.

    Science.gov (United States)

    Phillips, Steven; Wilson, William H

    2010-07-22

    Classical and Connectionist theories of cognitive architecture seek to explain systematicity (i.e., the property of human cognition whereby cognitive capacity comes in groups of related behaviours) as a consequence of syntactically and functionally compositional representations, respectively. However, both theories depend on ad hoc assumptions to exclude specific instances of these forms of compositionality (e.g. grammars, networks) that do not account for systematicity. By analogy with the Ptolemaic (i.e. geocentric) theory of planetary motion, although either theory can be made to be consistent with the data, both nonetheless fail to fully explain it. Category theory, a branch of mathematics, provides an alternative explanation based on the formal concept of adjunction, which relates a pair of structure-preserving maps, called functors. A functor generalizes the notion of a map between representational states to include a map between state transformations (or processes). In a formal sense, systematicity is a necessary consequence of a higher-order theory of cognitive architecture, in contrast to the first-order theories derived from Classicism or Connectionism. Category theory offers a re-conceptualization for cognitive science, analogous to the one that Copernicus provided for astronomy, where representational states are no longer the center of the cognitive universe--replaced by the relationships between the maps that transform them.

  13. Application of Monte-Carlo method in definition of key categories of most radioactive polluted soil

    International Nuclear Information System (INIS)

    Mahmudov, H.M.; Valibeyova, G.; Jafarov, Y.D.; Musaeva, Sh.Z.

    2006-01-01

    Full text: The principle of analysis by Monte Carlo method consists of a choice of random variables of coefficients of an exposition doze capacities of radiation and data on activity within the boundaries of their individual density of frequency distribution upon corresponding sizes of exposition doses capacities. This procedure repeats for many times using computer and results of each round of calculations create universal density of frequency distribution of exposition doses capacities. The analysis using Monte Carlo method can be carried out at the level of radiation polluted soil categories. The analysis by Monte Carlo method is useful for realization of sensitivity analysis of measured capacity amount of an exposition dose in order to define the major factors causing uncertainty in reports. Reception of such conceptions can be valuable for definition of key categories of radiation polluted soil and establishment of priorities to use resources for enhancement of the report. Relative uncertainty of radiation polluted soil categories determined with the help of the analysis by Monte Carlo method in case of their availability can be applied using more significant divergence between average value and a confidential limit in case when borders of a confidential interval are asymmetric. It is important to determine key categories of radiation polluted soil to establish priorities to use reports of resources available for preparation and to prepare possible estimations for the most significant categories of sources. Usage of the notion u ncertainty i n reports also allows to set threshold value for a key category of sources, if it is necessary, for exact reflection of 90 percent uncertainty in reports. According to radiation safety norms level of radiation background exceeding 33 mkR/hour is considered dangerous. By calculated Monte Carlo method much more dangerous sites and sites frequently imposed to disposals and utilization were chosen from analyzed samples of

  14. Application of Monte-Carlo method in definition of key categories of most radioactive polluted soil

    Energy Technology Data Exchange (ETDEWEB)

    Mahmudov, H M; Valibeyova, G; Jafarov, Y D; Musaeva, Sh Z [Institute of Radiation Problems, Azerbaijan National Academy of Sciences, Baku (Azerbaijan)

    2006-11-15

    Full text: The principle of analysis by Monte Carlo method consists of a choice of random variables of coefficients of an exposition doze capacities of radiation and data on activity within the boundaries of their individual density of frequency distribution upon corresponding sizes of exposition doses capacities. This procedure repeats for many times using computer and results of each round of calculations create universal density of frequency distribution of exposition doses capacities. The analysis using Monte Carlo method can be carried out at the level of radiation polluted soil categories. The analysis by Monte Carlo method is useful for realization of sensitivity analysis of measured capacity amount of an exposition dose in order to define the major factors causing uncertainty in reports. Reception of such conceptions can be valuable for definition of key categories of radiation polluted soil and establishment of priorities to use resources for enhancement of the report. Relative uncertainty of radiation polluted soil categories determined with the help of the analysis by Monte Carlo method in case of their availability can be applied using more significant divergence between average value and a confidential limit in case when borders of a confidential interval are asymmetric. It is important to determine key categories of radiation polluted soil to establish priorities to use reports of resources available for preparation and to prepare possible estimations for the most significant categories of sources. Usage of the notion {sup u}ncertainty{sup i}n reports also allows to set threshold value for a key category of sources, if it is necessary, for exact reflection of 90 percent uncertainty in reports. According to radiation safety norms level of radiation background exceeding 33 mkR/hour is considered dangerous. By calted Monte Carlo method much more dangerous sites and sites frequently imposed to disposals and utilization were chosen from analyzed samples of

  15. Right away: A late, right-lateralized category effect complements an early, left-lateralized category effect in visual search.

    Science.gov (United States)

    Constable, Merryn D; Becker, Stefanie I

    2017-10-01

    According to the Sapir-Whorf hypothesis, learned semantic categories can influence early perceptual processes. A central finding in support of this view is the lateralized category effect-namely, the finding that categorically different colors (e.g., blue and green hues) can be discriminated faster than colors within the same color category (e.g., different hues of green), especially when they are presented in the right visual field. Because the right visual field projects to the left hemisphere, this finding has been popularly couched in terms of the left-lateralization of language. However, other studies have reported bilateral category effects, which has led some researchers to question the linguistic origins of the effect. Here we examined the time course of lateralized and bilateral category effects in the classical visual search paradigm by means of eyetracking and RT distribution analyses. Our results show a bilateral category effect in the manual responses, which is combined of an early, left-lateralized category effect and a later, right-lateralized category effect. The newly discovered late, right-lateralized category effect occurred only when observers had difficulty locating the target, indicating a specialization of the right hemisphere to find categorically different targets after an initial error. The finding that early and late stages of visual search show different lateralized category effects can explain a wide range of previously discrepant findings.

  16. Categorical perception of color: evidence from secondary category boundary

    Directory of Open Access Journals (Sweden)

    Al-rasheed AS

    2015-11-01

    Full Text Available Abdulrahman Saud Al-rasheed Department of Psychology, King Saud University, Riyadh, Kingdom of Saudi Arabia Abstract: Despite a plethora of behavioral research exploring the phenomenon of color categorical perception (CP known as "better discrimination between pair of colors stimuli from different categories and pair of colors stimuli from the same category even when the stimulus differences between the pairs of stimuli are equal", most of the evidence for the CP of color was derived from Roman or top-to-down script readers and very rarely from right-to-left script readers in primary category. To date, no studies of color CP have been conducted on right-to-left script readers in secondary category boundary to support this theory. Three experiments have been conducted: Experiments 1 and 2 established the Arabic blue–purple secondary category boundary, and Experiment 3 tested the CP of color in the blue–purple category boundary. Sixty participants (30 men and 30 women took part in this study. All spoke Arabic as their first language, and all were undergraduate or postgraduate students at King Saud University. Their ages ranged from 18–35 years with a mean age of 21.9 years (SD =5.2. The result indicated that for Experiments 1 and 2, it appeared that the Arabic blue–purple category boundary was approximately 10PB and it is in the same location as for English. For Experiment 3, reaction times in the between-categories condition were significantly faster than those in the within-category condition; this suggested that CP of color was shown in the Arabic's blue–purple secondary category boundary. Keywords: categorical perception, CP of color, categorization, blue–purple category boundary, secondary category boundary

  17. Generic task problem descriptions: Category B, C, and D tasks

    International Nuclear Information System (INIS)

    1978-06-01

    This document contains information relating to Category B, C, and D generic technical activities. The specific information provided for each task includes the reactor type to which the generic issue applies, the NRC division with lead responsibility and a description of the problem to be addressed by the task. Also provided in this document is a listing of Category A generic technical activities and definitions of Priority Categories A, B, C, and D

  18. Nature of Emotion Categories: Comment on Cowen and Keltner.

    Science.gov (United States)

    Barrett, Lisa Feldman; Khan, Zulqarnain; Dy, Jennifer; Brooks, Dana

    2017-12-22

    Cowen and Keltner (2017) published the latest installment in a longstanding debate about whether measures of emotion organize themselves into categories or array themselves more continuously along affective dimensions. We discuss several notable features of the study and suggest future studies should consider asking questions more directly about physical and psychological variation within emotion categories as well as similarities between categories. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A Category Based Threat Evaluation Model Using Platform Kinematics Data

    Directory of Open Access Journals (Sweden)

    Mustafa Çöçelli

    2017-08-01

    Full Text Available Command and control (C2 systems direct operators to make accurate decisions in the stressful atmosphere of the battlefield at the earliest. There are powerful tools that fuse various instant piece of information and brings summary of those in front of operators. Threat evaluation is one of the important fusion method that provides these assistance to military people. However, C2 systems could be deprived of valuable data source due to the absence of capable equipment. This situation has a bad unfavorable influence on the quality of tactical picture in front of C2 operators. In this paper, we study on the threat evaluation model that take into account these deficiencies. Our method extracts threat level of various targets mostly from their kinematics in two dimensional space. In the meantime, classification of entities around battlefield is unavailable. Only, category of targets are determined as a result of sensors process, which is the information of whether entities belong to air or surface environment. Hereby, threat evaluation model is consist of three fundamental steps that runs on entities belongs to different environment separately: the extraction of threat assessment cues, threat selection based on Bayesian Inference and the calculation of threat assessment rating. We have evaluated performance of proposed model by simulating a set of synthetic scenarios.

  20. Categories of relations as models of quantum theory

    Directory of Open Access Journals (Sweden)

    Chris Heunen

    2015-11-01

    Full Text Available Categories of relations over a regular category form a family of models of quantum theory. Using regular logic, many properties of relations over sets lift to these models, including the correspondence between Frobenius structures and internal groupoids. Over compact Hausdorff spaces, this lifting gives continuous symmetric encryption. Over a regular Mal'cev category, this correspondence gives a characterization of categories of completely positive maps, enabling the formulation of quantum features. These models are closer to Hilbert spaces than relations over sets in several respects: Heisenberg uncertainty, impossibility of broadcasting, and behavedness of rank one morphisms.

  1. Abrupt category shifts during real-time person perception.

    Science.gov (United States)

    Freeman, Jonathan B

    2014-02-01

    Previous studies have suggested that real-time person perception relies on continuous competition, in which partially active categories smoothly compete over time. Here, two studies demonstrated the involvement of a different kind of competition. In Study 1, before participants selected the correct sex category for morphed faces, their mouse trajectories often exhibited a continuous attraction toward the incorrect category that increased with sex-category ambiguity, indicating continuous competition. On other trials, however, trajectories initially pursued the incorrect category and then abruptly redirected toward the correct category, suggesting early incorrect category activation that was rapidly reversed later in processing. These abrupt category reversals also increased with ambiguity. In Study 2, participants were presented with faces containing a sex-typical or sex-atypical hair cue, in a context in which the norm was either sex-typical targets (normative context) or sex-atypical targets (counternormative context). Sex-atypical targets induced greater competition in the normative context, but sex-typical targets induced greater competition in the counternormative context. Together, these results demonstrate that categorizing others involves both smooth competition and abrupt category shifts, and that these flexibly adapt to the social context.

  2. On Anaphora and the Binding Principles in Categorial Grammar

    Science.gov (United States)

    Morrill, Glyn; Valentín, Oriol

    In type logical categorial grammar the analysis of an expression is a resource-conscious proof. Anaphora represents a particular challenge to this approach in that the antecedent resource is multiplied in the semantics. This duplication, which corresponds logically to the structural rule of contraction, may be treated lexically or syntactically. Furthermore, anaphora is subject to constraints, which Chomsky (1981) formulated as Binding Principles A, B, and C. In this paper we consider English anaphora in categorial grammar including reference to the binding principles. We invoke displacement calculus, modal categorial calculus, categorial calculus with limited contraction, and entertain addition of negation as failure.

  3. On the (un)suitability of semantic categories

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    2009-01-01

    Since Greenberg’s groundbreaking publication on universals of grammar, typologists have used semantic categories to investigate (constraints on) morphological and syntactic variation in the world’s languages and this tradition has been continued in the WALS project. It is argued here that the emp......Since Greenberg’s groundbreaking publication on universals of grammar, typologists have used semantic categories to investigate (constraints on) morphological and syntactic variation in the world’s languages and this tradition has been continued in the WALS project. It is argued here...... that the employment of semantic categories has some serious drawbacks, however, suggesting that semantic categories, just like formal categories, cannot be equated across languages in morphosyntactic typology. Whereas formal categories are too narrow in that they do not cover all structural variants attested across...... languages, semantic categories can be too wide, including too many structural variants. Furthermore, it appears that in some major typological studies semantic categories have been confused with formal categories. A possible solution is pointed out: typologists first need to make sure that the forms...

  4. MOST SOLD CATEGORIES FOOD SUPPLEMENTS IN BULGARIAN PHARMACIES - RESEARCH

    OpenAIRE

    Elina Petkova1, Kalin Ivanov2, Stanislava Ivanova2*, Stanislav Gueorguiev3, Radiana Staynova3

    2017-01-01

    The aim of this study is to investigate which are the most sold categories food supplements in Bulgarian pharmacies. The survey covers 820 pharmacies across the country. We have found that the leading category of food supplements is “Immune and digestive health” (41.5%). The second place is for the “Bone and joint health” (12.9%). The “Urology” category (consisted mainly by plant extracts) is about 7.9%. Food supplements in the “Urology” category are not only recommended by pharmacists but of...

  5. Mere exposure alters category learning of novel objects

    Directory of Open Access Journals (Sweden)

    Jonathan R Folstein

    2010-08-01

    Full Text Available We investigated how mere exposure to complex objects with correlated or uncorrelated object features affects later category learning of new objects not seen during exposure. Correlations among pre-exposed object dimensions influenced later category learning. Unlike other published studies, the collection of pre-exposed objects provided no information regarding the categories to be learned, ruling out unsupervised or incidental category learning during pre-exposure. Instead, results are interpreted with respect to statistical learning mechanisms, providing one of the first demonstrations of how statistical learning can influence visual object learning.

  6. Mere exposure alters category learning of novel objects.

    Science.gov (United States)

    Folstein, Jonathan R; Gauthier, Isabel; Palmeri, Thomas J

    2010-01-01

    We investigated how mere exposure to complex objects with correlated or uncorrelated object features affects later category learning of new objects not seen during exposure. Correlations among pre-exposed object dimensions influenced later category learning. Unlike other published studies, the collection of pre-exposed objects provided no information regarding the categories to be learned, ruling out unsupervised or incidental category learning during pre-exposure. Instead, results are interpreted with respect to statistical learning mechanisms, providing one of the first demonstrations of how statistical learning can influence visual object learning.

  7. Color categories only affect post-perceptual processes when same- and different-category colors are equally discriminable.

    Science.gov (United States)

    He, Xun; Witzel, Christoph; Forder, Lewis; Clifford, Alexandra; Franklin, Anna

    2014-04-01

    Prior claims that color categories affect color perception are confounded by inequalities in the color space used to equate same- and different-category colors. Here, we equate same- and different-category colors in the number of just-noticeable differences, and measure event-related potentials (ERPs) to these colors on a visual oddball task to establish if color categories affect perceptual or post-perceptual stages of processing. Category effects were found from 200 ms after color presentation, only in ERP components that reflect post-perceptual processes (e.g., N2, P3). The findings suggest that color categories affect post-perceptual processing, but do not affect the perceptual representation of color.

  8. Application of monte-carlo method in definition of key categories of most radioactive polluted soil

    Energy Technology Data Exchange (ETDEWEB)

    Mahmudov, H M; Valibeyova, G; Jafarov, Y D; Musaeva, Sh Z [Institute of Radiation Problems, Azerbaijan National Academy of Sciences, Baku (Azerbaijan); others, and

    2006-10-15

    Full text: The principle of analysis by Monte Carlo method consists of a choice of random variables of coefficients of an exposition doze capasites of radiation and data on activity within the boundaries of their individual density of frequency distribution of exposition doses capacities.The analysis using Monte Carlo method is useful for realization of sensitivity analysis of measured capacity amount of an exposition dose in order to define the major factors causing uncertainly in reports.Reception of such conceptions can be valuable for definition of key categories of radiation polluted soil and establishment of priorities to use resources for enhancement of the report.Relative uncertainly of radiation polluted soil categories determined with the help of the analysis by Monte Carlo method in case of their availability can be applied using more significant divergence between average value and a confidential limit in case when borders of resources available for preparation and to prepare possible estimations for the most significant categories of sources.Usage of the notion {sup u}ncertainty{sup i}n reports also allows to set threshold value for a key category of sources, if it necessary, for exact reflection of 90 per cent uncertainty in reports.According to radiation safety norms level of radiation backgrounds exceeding 33 mkR/hour is considered dangerous.By calculated Monte Carlo method much more dangerous sites and sites frequently imposed to disposals and utilization were chosen from analyzed samples of polluted soil.

  9. Application of monte-carlo method in definition of key categories of most radioactive polluted soil

    International Nuclear Information System (INIS)

    Mahmudov, H.M; Valibeyova, G.; Jafarov, Y.D; Musaeva, Sh.Z

    2006-01-01

    Full text: The principle of analysis by Monte Carlo method consists of a choice of random variables of coefficients of an exposition doze capasites of radiation and data on activity within the boundaries of their individual density of frequency distribution of exposition doses capacities.The analysis using Monte Carlo method is useful for realization of sensitivity analysis of measured capacity amount of an exposition dose in order to define the major factors causing uncertainly in reports.Reception of such conceptions can be valuable for definition of key categories of radiation polluted soil and establishment of priorities to use resources for enhancement of the report.Relative uncertainly of radiation polluted soil categories determined with the help of the analysis by Monte Carlo method in case of their availability can be applied using more significant divergence between average value and a confidential limit in case when borders of resources available for preparation and to prepare possible estimations for the most significant categories of sources.Usage of the notion u ncertainty i n reports also allows to set threshold value for a key category of sources, if it necessary, for exact reflection of 90 per cent uncertainty in reports.According to radiation safety norms level of radiation backgrounds exceeding 33 mkR/hour is considered dangerous.By calculated Monte Carlo method much more dangerous sites and sites frequently imposed to disposals and utilization were chosen from analyzed samples of polluted soil.

  10. Chandra Source Catalog: User Interface

    Science.gov (United States)

    Bonaventura, Nina; Evans, Ian N.; Rots, Arnold H.; Tibbetts, Michael S.; van Stone, David W.; Zografou, Panagoula; Primini, Francis A.; Glotfelty, Kenny J.; Anderson, Craig S.; Chen, Judy C.; Davis, John E.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G., II; Grier, John D.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; He, Helen; Houck, John C.; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Nowak, Michael A.; Plummer, David A.; Refsdal, Brian L.; Siemiginowska, Aneta L.; Sundheim, Beth A.; Winkelman, Sherry L.

    2009-09-01

    The Chandra Source Catalog (CSC) is intended to be the definitive catalog of all X-ray sources detected by Chandra. For each source, the CSC provides positions and multi-band fluxes, as well as derived spatial, spectral, and temporal source properties. Full-field and source region data products are also available, including images, photon event lists, light curves, and spectra. The Chandra X-ray Center CSC website (http://cxc.harvard.edu/csc/) is the place to visit for high-level descriptions of each source property and data product included in the catalog, along with other useful information, such as step-by-step catalog tutorials, answers to FAQs, and a thorough summary of the catalog statistical characterization. Eight categories of detailed catalog documents may be accessed from the navigation bar on most of the 50+ CSC pages; these categories are: About the Catalog, Creating the Catalog, Using the Catalog, Catalog Columns, Column Descriptions, Documents, Conferences, and Useful Links. There are also prominent links to CSCview, the CSC data access GUI, and related help documentation, as well as a tutorial for using the new CSC/Google Earth interface. Catalog source properties are presented in seven scientific categories, within two table views: the Master Source and Source Observations tables. Each X-ray source has one ``master source'' entry and one or more ``source observation'' entries, the details of which are documented on the CSC ``Catalog Columns'' pages. The master source properties represent the best estimates of the properties of a source; these are extensively described on the following pages of the website: Position and Position Errors, Source Flags, Source Extent and Errors, Source Fluxes, Source Significance, Spectral Properties, and Source Variability. The eight tutorials (``threads'') available on the website serve as a collective guide for accessing, understanding, and manipulating the source properties and data products provided by the catalog.

  11. THE CATEGORY OF COUNTABILITY IN THE CROATIAN LANGUAGE

    Directory of Open Access Journals (Sweden)

    Marija Znika

    2005-01-01

    Full Text Available This paper considers the category of countability as a category established on the lexical meaning of nouns. The lexical meaning of nouns can be dually structured, in a unit and mass forms, relative to the opposition one ≠ many. The category of countability has its content and expression. The content of the category of countability consists of the feature [± countable], and its marker [+ countable] and [- countable]. A noun is countable if its content can be conceived as a unit opposed to mass (table, apple. A noun is uncoutable if its content cannot be perceived as a unit that could be opposed to mass (water, sugar. The expression of the category of countability depends on its content. In the Croatian language the category of countability has its expression in the grammatical category of number and its grammems: singular and plural. These two grammems are formally, and frequently accentually, distinctive from the majority of nouns. The analysis focuses on the meaning of nouns, while their expression is considered as a possible indicator of semantic relationships the category of countability is based on. The paper analyses pluralia tantum and singularia tantum, and their different status countability-wise. It points out the possibility of semantic recategorization of nouns and thus demonstrates a dynamic quality of the category of countability. It also analyses the process of appelativisation (eponomisation of personal names, and the process of appelative deappelativisation. It shows the relationship between the category of countability and the category of definiteness, when definiteness is expressed by an adjectival aspect.

  12. 40 CFR 407.76 - Pretreatment standards for new sources.

    Science.gov (United States)

    2010-07-01

    ... GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE CATEGORY Canned and Preserved Vegetables Subcategory § 407.76 Pretreatment standards for new sources. Any new source...

  13. 40 CFR 407.66 - Pretreatment standards for new sources.

    Science.gov (United States)

    2010-07-01

    ... GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE CATEGORY Canned and Preserved Fruits Subcategory § 407.66 Pretreatment standards for new sources. Any new source...

  14. Normal and abnormal category-effects in visual object recognition

    DEFF Research Database (Denmark)

    Gerlach, Christian

    2017-01-01

    Are all categories of objects recognized in the same manner visually? Evidence from neuropsychology suggests they are not, as some brain injured patients are more impaired in recognizing natural objects than artefacts while others show the opposite impairment. In an attempt to explain category-sp...

  15. Accounting for a Functional Category: German "Drohen" "to Threaten"

    Science.gov (United States)

    Heine, Bernd; Miyashita, Hiroyuki

    2008-01-01

    In many languages there are words that behave like lexical verbs and on the one hand and like functional categories expressing distinctions of tense, aspect, modality, etc. on the other. The grammatical status of such words is frequently controversial; while some authors treat them as belonging to one and the same grammatical category, others…

  16. Can Semi-Supervised Learning Explain Incorrect Beliefs about Categories?

    Science.gov (United States)

    Kalish, Charles W.; Rogers, Timothy T.; Lang, Jonathan; Zhu, Xiaojin

    2011-01-01

    Three experiments with 88 college-aged participants explored how unlabeled experiences--learning episodes in which people encounter objects without information about their category membership--influence beliefs about category structure. Participants performed a simple one-dimensional categorization task in a brief supervised learning phase, then…

  17. Lifting to cluster-tilting objects in higher cluster categories

    OpenAIRE

    Liu, Pin

    2008-01-01

    In this note, we consider the $d$-cluster-tilted algebras, the endomorphism algebras of $d$-cluster-tilting objects in $d$-cluster categories. We show that a tilting module over such an algebra lifts to a $d$-cluster-tilting object in this $d$-cluster category.

  18. 29 CFR 4044.11 - Priority category 1 benefits.

    Science.gov (United States)

    2010-07-01

    ... priority category 1 with respect to that participant is the present value of that annuity. ... 29 Labor 9 2010-07-01 2010-07-01 false Priority category 1 benefits. 4044.11 Section 4044.11 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION PLAN TERMINATIONS ALLOCATION OF...

  19. 41 CFR 105-62.101 - Security classification categories.

    Science.gov (United States)

    2010-07-01

    ... three categories: Namely, Top Secret, Secret, or Confidential, depending on its degree of significance... provided by statute. The three classification categories are defined as follows: (a) Top Secret. Top Secret... with the utmost restraint. (b) Secret. Secret refers to that national security information or material...

  20. Towards the development of a salinity impact category for South ...

    African Journals Online (AJOL)

    DRINIE

    2003-07-03

    Jul 3, 2003 ... nature from existing categories to warrant a separate salinity impact category. A conceptual method is ... compounds to the environment from all stages of a product's life- cycle are ... Marine. - Terrestrial. • Photo-oxidant formation. • Acidification .... algae. Reduced light input. Oxygen depletion near bottom.

  1. CATEGORY OF CIRCUMVENTION OF THE LAW IN RUSSIAN CIVIL LAW

    OpenAIRE

    Kamyshanskiy V. P.

    2014-01-01

    This article examines the concept of "circumvention of the law" with respect to Treaty law. The author finds that the direct loan category "circumvention of the law" in Treaty law can be estimated ambiguously. The specified category which is fragmentary reflected in the active Civil codex indicates a regulatory gap

  2. The size of patent categories: USPTO 1976-2006

    NARCIS (Netherlands)

    Lafond, F.D.

    2014-01-01

    Categorization is an important phenomenon in science and society, and classification systems reflect the mesoscale organization of knowledge. The Yule-Simon-Naranan model, which assumes exponential growth of the number of categories and exponential growth of individual categories predicts a power

  3. What Does the Right Hemisphere Know about Phoneme Categories?

    Science.gov (United States)

    Wolmetz, Michael; Poeppel, David; Rapp, Brenda

    2011-01-01

    Innate auditory sensitivities and familiarity with the sounds of language give rise to clear influences of phonemic categories on adult perception of speech. With few exceptions, current models endorse highly left-hemisphere-lateralized mechanisms responsible for the influence of phonemic category on speech perception, based primarily on results…

  4. Porcament : category management in de verse varkensvleesketen : AKK eindrapport

    NARCIS (Netherlands)

    Immink, V.M.; Heijden, van der C.H.T.M.

    2004-01-01

    Dit rapport geeft inzichten in de belangrijkste aspecten die een rol spelen bij de introductie van category management in de 'vers-vlees' categorie. Het biedt een overzicht van de leerervaringen en hoe daar in de praktijk mee omgegaan kan worden

  5. 34 CFR 75.264 - Transfers among budget categories.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Transfers among budget categories. 75.264 Section 75.264 Education Office of the Secretary, Department of Education DIRECT GRANT PROGRAMS How Grants Are Made Miscellaneous § 75.264 Transfers among budget categories. A grantee may, notwithstanding any...

  6. 14 CFR 1206.701 - Categories of requesters.

    Science.gov (United States)

    2010-01-01

    ... are representatives of the news media. NASA shall provide documents to requesters in this category for... scientific institutions; representatives of the news media; and all other requesters. The Act prescribes specific levels of fees for each of these categories: (a) Commercial use requesters. When NASA receives a...

  7. Representation of categories: metaphorical use of the container schema

    NARCIS (Netherlands)

    Boot, I.; Pecher, D.

    2011-01-01

    In the present study we investigated whether the mental representation of the concept categories is represented by the container image schema (Lakoff & Johnson, 1980). In two experiments participants decided whether two pictures were from the same category (animal or vehicle). Pictures were

  8. 14 CFR 61.68 - Category III pilot authorization requirements.

    Science.gov (United States)

    2010-01-01

    ...) The addition of another type of aircraft to the applicant's Category III pilot authorization. (2) To... height, as applicable, including use of a radar altimeter; (iii) Recognition of and proper reaction to... an aircraft of the same category and class, and type, as applicable, as the aircraft for which the...

  9. 5 CFR 575.104 - Ineligible categories of employees.

    Science.gov (United States)

    2010-01-01

    ... INCENTIVES Recruitment Incentives § 575.104 Ineligible categories of employees. An agency may not pay a recruitment incentive to an employee in— (a) A position to which an individual is appointed by the President... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Ineligible categories of employees. 575...

  10. A review of functional imaging studies on category-specificity

    DEFF Research Database (Denmark)

    Gerlach, Christian

    2007-01-01

    such as familiarity and visual complexity. Of the most consistent activations found, none appear to be selective for natural objects or artefacts. The findings reviewed are compatible with theories of category-specificity that assume a widely distributed conceptual system not organized by category....

  11. Lexical categories in African languages: The case of adjectives word ...

    African Journals Online (AJOL)

    An endeavor to establish typical lexical categories in individual languages as well as a typology of word-classes yields contradictory conclusions. In this paper we provide evidence to substantiate the existence of an independent and indispensable open category of adjectives in the Bantu language Nyakyusa. An argument ...

  12. 3D quantification of clinical marginal and internal gap of porcelain laminate veneers with minimal and without tooth preparation and 2-year clinical evaluation.

    Science.gov (United States)

    Karagözoğlu, İrem; Toksavul, Suna; Toman, Muhittin

    2016-01-01

    The aims of this clinical study were to compare internal three-dimensional (3D) adaptation of porcelain laminate veneers (PLV) with minimal tooth preparation and without tooth preparation (prepless) and to evaluate the clinical outcomes at baseline and following 6, 12, and 24 months after luting. Thirty-one prepless PLV and 31 PLV with minimal tooth preparation were fabricated using lithium disilicate glass-ceramic material and placed in 12 patients (8 women, 4 men; 18 to 40 years old). All PLV were luted with an adhesive luting system (Variolink veneer). A silicone replica was obtained to measure internal adaptation of each PLV using a low viscosity polyvinyl siloxane impression material just before luting. Silicone replicas were scanned in x-ray micro computerized tomography (micro CT). Clinical evaluations took place at baseline (2 days after luting) and following 6, 12, and 24 months after luting. Marginal integrity, marginal discoloration, secondary caries, tooth sensitivity, and fracture were evaluated following FDI criteria. Replica scores were analyzed using Mann-Whitney U and Student's t test (α = .05). Kaplan-Meier statistical analysis was done for the survival rate of PLV. FDI criteria scores were analyzed using Pearson's chi-square test (α = .05). The median marginal gaps for PLV-without-tooth-preparation and PLV-with-minimal-tooth-preparation groups were 100 μm and 140 μm respectively. There was a statistically significant difference between the two groups with respect to marginal gap (P = .04). The mean internal adaptation for the PLV-without-tooth-preparation group was 217.17 ± 54.72 μm, and was 170.67 ± 46.54 μm for the PLV-with-minimaltooth- preparation group. There was a statistically significant difference between the two groups (P = .001). Based on FDI criteria, 100% of the PLV were rated satisfactory during the 2-year period. In this in-vivo study, mean and median values of marginal gap and internal adaptation for PLV with minimal tooth

  13. Evaluation of bond strength between grooved titanium alloy implant abutments and provisional veneering materials after surface treatment of the abutments: An in vitro study

    Directory of Open Access Journals (Sweden)

    Gowtham Venkat

    2017-01-01

    Full Text Available Introduction: Titanium has become the material of choice with greater applications in dental implants. The success of the dental implant does not only depend on the integration of the implant to the bone but also on the function and longevity of the superstructure. The clinical condition that demands long-term interim prosthesis is challenging owing to the decreased bond between the abutment and the veneering material. Hence, various surface treatments are done on the abutments to increase the bond strength. Aim: This study aimed to evaluate the bond strength between the abutment and the provisional veneering materials by surface treatments such as acid etching, laser etching, and sand blasting of the abutment. Materials and Methods: Forty titanium alloy abutments of 3 mm diameter and 11 mm height were grouped into four groups with ten samples. Groups A, B, C, and D are untreated abutments, sand blasted with 110 μm aluminum particles, etched with 1% hydrofluoric acid and 30% nitric acid, and laser etched with Nd: YAG laser, respectively. Provisional crowns were fabricated with bis-acrylic resin and cemented with noneugenol temporary luting cement. The shear bond strength was measured in universal testing machine using modified Shell–Nielsen shear test after the cemented samples were stored in water at 25°C for 24 h. Load was applied at a constant cross head speed of 5 mm/min until a sudden decrease in resistance indicative of bond failure was observed. The corresponding force values were recorded, and statistical analysis was done using one-way ANOVA and Newman–Keuls post hoc test. Results: The laser-etched samples showed higher bond strength. Conclusion: Among the three surface treatments, laser etching showed the highest bond strength between titanium alloy implant abutment and provisional restorations. The sand-blasted surfaces demonstrated a significant difference in bond strength compared to laser-etched surfaces. The results of this

  14. Violence against adolescents: an analysis based on the categories gender and generation

    OpenAIRE

    Gessner, Rafaela; Fonseca, Rosa Maria Godoy Serpa da; Oliveira, Rebeca Nunes Guedes de

    2014-01-01

    Exploratory and descriptive study based on quantitative and qualitative methods that analyze the phenomenon of violence against adolescents based on gender and generational categories. The data source was reports of violence from the Curitiba Protection Network from 2010 to 2012 and semi-structured interviews with 16 sheltered adolescents. Quantitative data were analyzed using SPSS software version 20.0 and the qualitative data were subjected to content analysis. The adolescents were victims ...

  15. Categorical perception of color: evidence from secondary category boundary

    Science.gov (United States)

    Al-rasheed, Abdulrahman Saud

    2015-01-01

    Despite a plethora of behavioral research exploring the phenomenon of color categorical perception (CP) known as “better discrimination between pair of colors stimuli from different categories and pair of colors stimuli from the same category even when the stimulus differences between the pairs of stimuli are equal”, most of the evidence for the CP of color was derived from Roman or top-to-down script readers and very rarely from right-to-left script readers in primary category. To date, no studies of color CP have been conducted on right-to-left script readers in secondary category boundary to support this theory. Three experiments have been conducted: Experiments 1 and 2 established the Arabic blue–purple secondary category boundary, and Experiment 3 tested the CP of color in the blue–purple category boundary. Sixty participants (30 men and 30 women) took part in this study. All spoke Arabic as their first language, and all were undergraduate or postgraduate students at King Saud University. Their ages ranged from 18–35 years with a mean age of 21.9 years (SD =5.2). The result indicated that for Experiments 1 and 2, it appeared that the Arabic blue–purple category boundary was approximately 10PB and it is in the same location as for English. For Experiment 3, reaction times in the between-categories condition were significantly faster than those in the within-category condition; this suggested that CP of color was shown in the Arabic’s blue–purple secondary category boundary. PMID:26648764

  16. In Vitro Comparison of Marginal and Internal Fit of Press-on-Metal Ceramic (PoM) Restorations with Zirconium-Supported and Conventional Metal Ceramic Fixed Partial Dentures Before and After Veneering.

    Science.gov (United States)

    Varol, Seda; Kulak-Özkan, Yasemin

    2015-07-01

    To compare marginal and internal fit between 3- and 4-unit press-on-metal (PoM) ceramic, zirconia-supported, and conventional metal ceramic fixed partial dentures (FPDs) before and after veneering. Ten pieces for each 3- and 4-unit MC, IPS InLine PoM, and IPS e.max ZirCAD/Zir Press FPDs were produced. Cross-sections from silicone replicas were examined and measured with a light microscope. Occlusal, axial, intermarginal, and marginal mean adaptation scores of cross-sectioned replicas and means of measurements obtained from 4 sites were calculated independently. Mean values for molars were 78.44 ± 32.01 μm (MC), 89.84 ± 29.20 μm (PoM), and 85.17 ± 28.49 μm (Zir). Premolar values were 76.08 ± 27.92 μm (MC), 89.94 ± 23.49 μm (PoM), and 87.18 ± 28.25 μm (Zir). No difference existed between the means of 3- and 4-unit FPDs except the molar-intermarginal region. The mean value of 4-unit FPDs (93.88 ± 25.41 μm) was less than the 3-unit FPDs (103.68 ± 24.55 μm) at the molar-inter marginal region. A gap increase was observed in all sites except the molar-axio-occlusal region after veneering. According to the mean difference, gap increases at the molar-marginal, molar-intermarginal, and premolar-intermarginal regions were statistically significant. A statistical difference was found at the molar-marginal region for 4-unit MCR (p = 0.041) and 4-unit PoM FPDs (p = 0.042) before and after veneering. Gap increase after veneering of 4-unit metal ceramics at molar-intermarginal, premolar-marginal, and premolar-intermarginal regions (p = 0.020; p = 0.015; p = 0.004) was significant. The gap measurements of the IPS InLine PoM and IPS e.max ZirCAD/Zir Press groups were all clinically acceptable. No studies on marginal and internal fit in the IPS InLine PoM system have been published to date. This study should be supported with future studies. No significant increase was observed after press-veneering the IPS e.max ZirCAD frameworks with an IPS e.max ZirPress material

  17. Categorization of radiation sources

    International Nuclear Information System (INIS)

    Antonova, M.

    2000-01-01

    Through one-parameter (factor) analysis it is proved a hypothesis that the value of a radiation source (RS) activity of an application correlates with the category (the rank) given to it by the IAEA categorization although it is based on other parameters of the RS applications (practices like devices with radiation sources in industry, science, medicine and agriculture). The principles of the new IAEA categorization, taking into account the potential harm the sources may cause and the necessary regulatory control, are described. (author)

  18. The Role of Corticostriatal Systems in Speech Category Learning.

    Science.gov (United States)

    Yi, Han-Gyol; Maddox, W Todd; Mumford, Jeanette A; Chandrasekaran, Bharath

    2016-04-01

    One of the most difficult category learning problems for humans is learning nonnative speech categories. While feedback-based category training can enhance speech learning, the mechanisms underlying these benefits are unclear. In this functional magnetic resonance imaging study, we investigated neural and computational mechanisms underlying feedback-dependent speech category learning in adults. Positive feedback activated a large corticostriatal network including the dorsolateral prefrontal cortex, inferior parietal lobule, middle temporal gyrus, caudate, putamen, and the ventral striatum. Successful learning was contingent upon the activity of domain-general category learning systems: the fast-learning reflective system, involving the dorsolateral prefrontal cortex that develops and tests explicit rules based on the feedback content, and the slow-learning reflexive system, involving the putamen in which the stimuli are implicitly associated with category responses based on the reward value in feedback. Computational modeling of response strategies revealed significant use of reflective strategies early in training and greater use of reflexive strategies later in training. Reflexive strategy use was associated with increased activation in the putamen. Our results demonstrate a critical role for the reflexive corticostriatal learning system as a function of response strategy and proficiency during speech category learning. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Categories of fruit and vegetables: Attributes and definitions in Serbian

    Directory of Open Access Journals (Sweden)

    Dilparić Branislava M.

    2011-01-01

    Full Text Available According to the results of an empirical investigation performed by E. Rosch and K. Mervis (1975, the prototype structures of the categories FRUIT and VEGETABLES, the two superordinate and neighbouring categories with no clear-cut boundaries between them, are formed by family resemblances. Each category has only two attributes ('(part of a plant' and 'edible' which are common to all its members and yet not sufficient to define the category and separate it from other categories of edible (parts of plants. Through the analysis and comparison of a number of definitions for FRUIT and VEGETABLES (obtained in a questionnaire-based survey from a hundred native speakers of Serbian; taken from Lexicography and Conceptual Analysis by A. Wierzbicka; taken from five general dictionaries of the Serbian language, the author of this paper attempts to determine the group of attributes that could play a key role in differentiating the observed categories and to search for the most appropriate way to define the two categories in Serbian which would hopefully be acceptable to both modern (prototype semantics and practical lexicography.

  20. Typicality effects in artificial categories: is there a hemisphere difference?

    Science.gov (United States)

    Richards, L G; Chiarello, C

    1990-07-01

    In category classification tasks, typicality effects are usually found: accuracy and reaction time depend upon distance from a prototype. In this study, subjects learned either verbal or nonverbal dot pattern categories, followed by a lateralized classification task. Comparable typicality effects were found in both reaction time and accuracy across visual fields for both verbal and nonverbal categories. Both hemispheres appeared to use a similarity-to-prototype matching strategy in classification. This indicates that merely having a verbal label does not differentiate classification in the two hemispheres.

  1. Probability based load combinations for design of category I structures

    International Nuclear Information System (INIS)

    Reich, M.; Hwang, H.

    1985-01-01

    This paper discusses a reliability analysis method and a procedure for developing the load combination design criteria for category I structures. For safety evaluation of category I concrete structures under various static and dynamic loads, a probability-based reliability analysis method has been developed. This reliability analysis method is also used as a tool for determining the load factors for design of category I structures. In this paper, the load combinations for design of concrete containments, corresponding to a target limit state probability of 1.0 x 10 -6 in 4 years, are described. A comparison of containments designed using the ASME code and the proposed design criteria is also presented

  2. The Category of Time in English, Russian and French Phraseology

    Directory of Open Access Journals (Sweden)

    Elena A. Makleeva

    2017-09-01

    Full Text Available In the paper we make an attempt to analyze linguistic and cultural descriptions of phraseological units of English, Russian and French reflecting the category of time. In the study of each language about 200 of phraseological units associated with the category of time were taken, which were divided into 5 groups representing different phraseo-semantic concepts. We have carried out a semantic analysis of the data of phraseological units identified by national-cultural peculiarities of expression of time category. The results can be used in the practice of teaching English, Russian and French as foreign languages, in courses on linguistics, and are also taken into account compiling dictionaries.

  3. Solving the Selective Multi-Category Parallel-Servicing Problem

    DEFF Research Database (Denmark)

    Range, Troels Martin; Lusby, Richard Martin; Larsen, Jesper

    In this paper we present a new scheduling problem and describe a shortest path based heuristic as well as a dynamic programming based exact optimization algorithm to solve it. The Selective Multi-Category Parallel-Servicing Problem (SMCPSP) arises when a set of jobs has to be scheduled on a server...... (machine) with limited capacity. Each job requests service in a prespecified time window and belongs to a certain category. Jobs may be serviced partially, incurring a penalty; however, only jobs of the same category can be processed simultaneously. One must identify the best subset of jobs to process...

  4. Solving the selective multi-category parallel-servicing problem

    DEFF Research Database (Denmark)

    Range, Troels Martin; Lusby, Richard Martin; Larsen, Jesper

    2015-01-01

    In this paper, we present a new scheduling problem and describe a shortest path-based heuristic as well as a dynamic programming-based exact optimization algorithm to solve it. The selective multi-category parallel-servicing problem arises when a set of jobs has to be scheduled on a server (machine......) with limited capacity. Each job requests service in a prespecified time window and belongs to a certain category. Jobs may be serviced partially, incurring a penalty; however, only jobs of the same category can be processed simultaneously. One must identify the best subset of jobs to process in each time...

  5. Client contribution in negotiations on employability – categories revised?

    DEFF Research Database (Denmark)

    Eskelinen, L.; Olesen, Søren Peter; Caswell, D.

    2010-01-01

    worker–client talk: how the category unemployed is shaped and ‘translated’ when the client negotiates her situation with the social worker. Two types of category revisions are identified. First, the employability of the client, rather than her unemployment situation, is the issue under negotiation......In this article, we explore how the institutional category ‘unemployed’ is specified in everyday practice when implementing an active employment policy. We illustrate the process of categorisation as an aspect of the in situ positioning and self-representation of the client by examining one social...

  6. Basis for category B designation for K basins

    International Nuclear Information System (INIS)

    Jensen, M.A.

    1994-01-01

    This Supporting Document analyzes the various fissile material configurations in the 105-K East and K West fuel storage basins to determine the proper firefighting category. Firefighting categories are assigned to fissionable material facilities to provide guidance to firefighters in the allowable uses of water and other extinguishing materials to prevent inadvertent rearrangement of fissile materials or addition of neutron moderators which could lead to a criticality. This document concludes the appropriate category is B, which does not impose any restrictions on the use of water for firefighting purposes

  7. Developing and Evaluating Composites Based on Plantation Eucalyptus Rotary-cut Veneer and High-density Polyethylene Film as Novel Building Materials

    Directory of Open Access Journals (Sweden)

    Wei Song

    2016-02-01

    Full Text Available To achieve value-added utilizations of plantation timbers, eucalyptus veneer/high-density polyethylene film composites were prepared, with process-factors (PF (hot-pressing temperature, HT; hot-pressing duration, HD; hot-pressing pressure, HP; HDPE-film content, HC and composite-properties (CP (water-resistant bonding-strength, BS; modulus of rupture, MOR; modulus of elasticity, MOE investigated. According to thermal analyses, 140 to 180 °C was appropriate for HT. Based on statistical analyses, HD was easier to affect CP, while MOE was easier to be affected by PF. Quantitative relationships between PF and CP were determined by the neural-network (ANN modeling. In ANN simulation surveys, CP displayed Gaussian distributions (R2 > 0.9 when PF changed in current ranges, with positive correlations between BS and MOR (R2 ≈ 0.5. Combining ANN and the genetic-algorithm, optimal processes (HT, 160 °C; HD, 50 s/mm; HP, 1.3 MPa; HC, 6 layers were found, and optimal results (BS, 1.30 MPa; MOR, 86.94 MPa; MOE, 8.33 GPa were comparable to various reported poplar-plywoods. Microscopic images demonstrated that composite interfaces were formed by the mechanical interlocking. The optimal BS attained Chinese standards for water-resistant plywoods, so proposed composites can serve as water-resistant and formaldehyde-free building materials for furniture and interior design.

  8. 40 CFR 427.35 - Standards of performance for new sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Paper (Starch Binder) Subcategory § 427.35 Standards of performance for new sources. The following standards of...

  9. 40 CFR 427.45 - Standards of performance for new sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Paper (Elastomeric Binder) Subcategory § 427.45 Standards of performance for new sources. The following standards of...

  10. Geospatial Information Categories Mapping in a Cross-lingual Environment: A Case Study of “Surface Water” Categories in Chinese and American Topographic Maps

    Directory of Open Access Journals (Sweden)

    Xi Kuai

    2016-06-01

    Full Text Available The need for integrating geospatial information (GI data from various heterogeneous sources has seen increased importance for geographic information system (GIS interoperability. Using domain ontologies to clarify and integrate the semantics of data is considered as a crucial step for successful semantic integration in the GI domain. Nevertheless, mechanisms are still needed to facilitate semantic mapping between GI ontologies described in different natural languages. This research establishes a formal ontology model for cross-lingual geospatial information ontology mapping. By first extracting semantic primitives from a free-text definition of categories in two GI classification standards with different natural languages, an ontology-driven approach is used, and a formal ontology model is established to formally represent these semantic primitives into semantic statements, in which the spatial-related properties and relations are considered as crucial statements for the representation and identification of the semantics of the GI categories. Then, an algorithm is proposed to compare these semantic statements in a cross-lingual environment. We further design a similarity calculation algorithm based on the proposed formal ontology model to distance the semantic similarities and identify the mapping relationships between categories. In particular, we work with two GI classification standards for Chinese and American topographic maps. The experimental results demonstrate the feasibility and reliability of the proposed model for cross-lingual geospatial information ontology mapping.

  11. 40 CFR 421.246 - Pretreatment standards for new sources.

    Science.gov (United States)

    2010-07-01

    ... GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Nickel Subcategory... reclaim leaching belt filter backwash. PSNS for the Secondary Nickel Subcategory Pollutant or pollutant...

  12. 40 CFR 417.166 - Pretreatment standards for new sources.

    Science.gov (United States)

    2010-07-01

    ... GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid... standard shall be: (1) For normal liquid detergent operations the following values pertain: Pollutant or...

  13. The effect of midazolam on implicit and explicit memory in category exemplar production and category cued recall.

    Science.gov (United States)

    Arndt, Jason; Passannante, Anthony; Hirshman, Elliot

    2004-03-01

    Transfer-appropriate processing theory (Roediger, Weldon, & Challis, 1989) proposes that dissociations between performance on explicit and implicit memory tests arise because these tests often rely on different types of information processing (e.g., perceptual processing vs conceptual processing). This perspective predicts that implicit and explicit memory tasks that rely primarily on conceptual processing should show comparable results, not dissociations. Numerous studies have demonstrated such similarities. It is, however, possible that these results arise from explicit memory contamination of performance on implicit memory tasks. To address this issue, an experiment was conducted in which participants were administered the sedative midazolam prior to study. Midazolam is known to create a temporary, but dense, period of anterograde amnesia. The effects of blocking stimulus materials by semantic category at study and generation at study were investigated on category exemplar production and category-cued recall. The results of this study demonstrated a dissociation of the effects of midazolam on category exemplar production and category-cued recall. Specifically, midazolam reduced the effect of blocking stimulus materials in category-cued recall, but not in category exemplar production. The differential effect of midazolam on explicit and implicit memory is at odds with transfer-appropriate processing theory and suggests that theories of memory must distinguish the roles of different types of conceptual processing on implicit and explicit memory tests.

  14. Reconceptualizing 'extremism' and 'moderation': from categories of analysis to categories of practice in the construction of collective identity.

    Science.gov (United States)

    Hopkins, Nick; Kahani-Hopkins, Vered

    2009-03-01

    Much psychological research employs the categories of extremism and moderation as categories of analysis (e.g. to identify the psychological bases for, and consequences of, holding certain positions). This paper argues these categorizations inevitably reflect one's values and taken-for-granted assumptions about social reality and that their use as analytic categories limits our ability to explore what is really important: social actors' own constructions of social reality. In turn we argue that if we are to focus on this latter, there may be merit in exploring how social actors themselves use the categories of moderation and extremism to construct their own terms of reference. That is we propose to re-conceptualize the categories of moderation and extremism as categories of practice rather than analysis. The utility of this approach is illustrated with qualitative data. We argue that these data illustrate the importance of respecting social actors' own constructions of social reality (rather than imposing our own). Moreover, we argue that categories of moderation and extremism may be employed by social actors in diverse ways to construct different terms of reference and so recruit support for different identity-related projects.

  15. ABOUT THE CORRELATION OF THE CATEGORIES «GUILT», «SHAME» AND «DISGRACE»

    Directory of Open Access Journals (Sweden)

    Екатерина Валерьевна Юрчак

    2013-12-01

    Full Text Available Category of "guilt" "shame" and "disgrace" in the theory of law is traditionally considered together because of the commonality of functionality. It is therefore necessary to determine how they relate to each other in the legal field .The purpose of this research provide a comparative description of categories of "guilt", "shame", "disgrace".Scientific and practical significance of the research lies in the fact that comparative studies of this nature help to reach a balance between the studied categories.The author uses an analytical, logical, philosophical and comparative- historical methods .The article analyzes the correlation of categories "guilt", "shame", "disgrace".The author concludes that shame and guilt have a different source of origin, are experienced differently by the individual , but may be tested simultaneously. Tradition shame is the most severe form of atonement , as a devotee must demonstrate publicly shame shame for their actions and apologize to the public.The results of this study provide scientific and practical value , since they can be used in teaching students of legal and philosophical disciplines and practitioners of the judicial and penal systems to achieve the purpose of maximum efficiency of the criminal punishment.DOI: http://dx.doi.org/10.12731/2218-7405-2013-10-18

  16. COGNITIVE-COMMUNICATIVE PERSONALITY CATEGORY IN THE KAZAKH LANGUAGE

    Directory of Open Access Journals (Sweden)

    Orynay Sagingalievna Zhubaeva

    2018-02-01

    Full Text Available The purpose of the research is to reveal the character of anthropocentricity of grammatical categories in their meaning and functioning. Materials and methods. According to the research objectives and goals, the methods used were as follows: the descriptive method, general scientific methods of analysis and synthesis, cognitive analysis, method of experiment, contextual analysis, structural-semantic analysis, transformation technique, comparative analysis. Results. For the first time in the Kazakh linguistics the substantial aspect of grammatical categories is characterized being a result of both conceptualization and categorization processes. Based on generalization and the comparative analysis of nature and forms of the human factor reflection in the Kazakh grammatical categories there has been revealed the national-cultural specific character of grammatical categories. Practical implications. The research materials can be used in theoretical courses onf grammar and linguistics, as well as in the development of special courses on cognitive linguistics, cognitive grammar, etc.

  17. Category 3 threshold quantities for hazard categorization of nonreactor facilities

    International Nuclear Information System (INIS)

    Mandigo, R.L.

    1996-01-01

    This document provides the information necessary to determine Hazard Category 3 threshold quantities for those isotopes of interest not listed in WHC-CM-4-46, Section 4, Table 1.''Threshold Quantities.''

  18. Effects of task and category membership on representation stability

    Directory of Open Access Journals (Sweden)

    Céline Manetta

    2011-01-01

    Full Text Available This study examined the within-subject stability of 150 participants who performed both a sorting task and a property-generation task over multiple sessions, focusing on three concrete concept categories (food, animals and bathroom products. We hypothesized that (1 the within-subject stability would be higher in the sorting task than in the property-generation task and (2 the nature of the category would influence both the within-subject stability of the classification groups in the sorting task and the properties generated to define these groups. The results show that the within-subject stability of conceptual representations depends both on the task and on the nature of the category. The stability of the representations was greater in the sorting task than in the property-generation task and in the food category. These results are discussed from a longitudinal perspective.

  19. Remanufacture Systems for Category 1 and 2 Marine Diesel Engines

    Science.gov (United States)

    EPA maintains a list of remanufacture systems, or “kits”, certified for use with Category 1 and 2 marine diesel engines according to the provisions of 40 CFR Part 1042, Subpart I, and is periodically updated.

  20. 77 FR 20281 - Designation of Product Categories for Federal Procurement

    Science.gov (United States)

    2012-04-04

    ... derived from imported oil and natural gas. When USDA designates by rulemaking a product category (a...: Vehicular Products--re-refined lubricating oils. USDA is requesting that manufacturers of these qualifying...

  1. LexGram - a practical categorial grammar formalism -

    OpenAIRE

    Koenig, Esther

    1995-01-01

    We present the LexGram system, an amalgam of (Lambek) categorial grammar and Head Driven Phrase Structure Grammar (HPSG), and show that the grammar formalism it implements is a well-structured and useful tool for actual grammar development.

  2. Goguen categories a categorical approach to l-fuzzy relations

    CERN Document Server

    Winter, Michael; Mundici, Daniele

    2007-01-01

    Goguen categories extend the relational calculus and its categorical formalization to the fuzzy world. Starting from the fundamental concepts of sets, binary relations and lattices this book introduces several categorical formulations of an abstract theory of relations such as allegories, Dedekind categories and related structures. It is shown that neither theory is sufficiently rich to describe basic operations on fuzzy relations. The book then introduces Goguen categories and provides a comprehensive study of these structures including their representation theory, and the definability of norm-based operations. The power of the theory is demonstrated by a comprehensive example. A certain Goguen category is used to specify and to develop a fuzzy controller. Based on its abstract description as well as certain desirable properties and their formal proofs, a verified controller is derived without compromising the - sometimes - intuitive choice of norm-based operations by fuzzy engineers.

  3. Correlation of Persistence, Initiative and Career Anchors Categories of Students

    Directory of Open Access Journals (Sweden)

    I A Novikova

    2008-03-01

    Full Text Available The article is devoted to the analysis of the results of comparative empirical study of persistence, initiative and Career Anchors categories of the students on the basis of the systemic-functional approach.

  4. Monoidal categories and the Gerstenhaber bracket in Hochschild cohomology

    CERN Document Server

    Hermann, Reiner

    2016-01-01

    In this monograph, the author extends S. Schwede's exact sequence interpretation of the Gerstenhaber bracket in Hochschild cohomology to certain exact and monoidal categories. Therefore the author establishes an explicit description of an isomorphism by A. Neeman and V. Retakh, which links \\mathrm{Ext}-groups with fundamental groups of categories of extensions and relies on expressing the fundamental group of a (small) category by means of the associated Quillen groupoid. As a main result, the author shows that his construction behaves well with respect to structure preserving functors between exact monoidal categories. The author uses his main result to conclude, that the graded Lie bracket in Hochschild cohomology is an invariant under Morita equivalence. For quasi-triangular bialgebras, he further determines a significant part of the Lie bracket's kernel, and thereby proves a conjecture by L. Menichi. Along the way, the author introduces n-extension closed and entirely extension closed subcategories of abe...

  5. Online Consumer Reviews: The Moderating Effect of Product Category

    OpenAIRE

    Bjering, Einar; Havro, Lars Jaakko

    2014-01-01

    This paper tests a previously proposed model for assessing consumer generated online reviews effect on sales, the review impact continuum. Product category is found to play an important role as a moderating factor of several properties concerning user generated online reviews - including its impact on sales. The authors introduce a novel method for product category classification using natural language processing (NLP), and by applying this method show that reviews are more influential for su...

  6. Calabi-Yau structures on categories of matrix factorizations

    Science.gov (United States)

    Shklyarov, Dmytro

    2017-09-01

    Using tools of complex geometry, we construct explicit proper Calabi-Yau structures, that is, non-degenerate cyclic cocycles on differential graded categories of matrix factorizations of regular functions with isolated critical points. The formulas involve the Kapustin-Li trace and its higher corrections. From the physics perspective, our result yields explicit 'off-shell' models for categories of topological D-branes in B-twisted Landau-Ginzburg models.

  7. Tangent mappings and convergent sequences in the lipschitz category

    OpenAIRE

    Hyman, Daniel M.

    2012-01-01

    The standard definition of a derivative in linear spaces is extended to a definition of tangency in the Lipschitz category, without any assumed algebraic structure on the underlying spaces.  Tangency is characterized topologically, that is, solely in terms of continuity, without using any algebraic concepts or other analytical concepts. The mappings in the Lipschitz category are characterized as the class of functions that preserve topologically convergent sequences of finite variation.

  8. Converging modalities ground abstract categories: the case of politics.

    Science.gov (United States)

    Farias, Ana Rita; Garrido, Margarida V; Semin, Gün R

    2013-01-01

    Three studies are reported examining the grounding of abstract concepts across two modalities (visual and auditory) and their symbolic representation. A comparison of the outcomes across these studies reveals that the symbolic representation of political concepts and their visual and auditory modalities is convergent. In other words, the spatial relationships between specific instances of the political categories are highly overlapping across the symbolic, visual and auditory modalities. These findings suggest that abstract categories display redundancy across modal and amodal representations, and are multimodal.

  9. A Bayesian Model of Category-Specific Emotional Brain Responses

    Science.gov (United States)

    Wager, Tor D.; Kang, Jian; Johnson, Timothy D.; Nichols, Thomas E.; Satpute, Ajay B.; Barrett, Lisa Feldman

    2015-01-01

    Understanding emotion is critical for a science of healthy and disordered brain function, but the neurophysiological basis of emotional experience is still poorly understood. We analyzed human brain activity patterns from 148 studies of emotion categories (2159 total participants) using a novel hierarchical Bayesian model. The model allowed us to classify which of five categories—fear, anger, disgust, sadness, or happiness—is engaged by a study with 66% accuracy (43-86% across categories). Analyses of the activity patterns encoded in the model revealed that each emotion category is associated with unique, prototypical patterns of activity across multiple brain systems including the cortex, thalamus, amygdala, and other structures. The results indicate that emotion categories are not contained within any one region or system, but are represented as configurations across multiple brain networks. The model provides a precise summary of the prototypical patterns for each emotion category, and demonstrates that a sufficient characterization of emotion categories relies on (a) differential patterns of involvement in neocortical systems that differ between humans and other species, and (b) distinctive patterns of cortical-subcortical interactions. Thus, these findings are incompatible with several contemporary theories of emotion, including those that emphasize emotion-dedicated brain systems and those that propose emotion is localized primarily in subcortical activity. They are consistent with componential and constructionist views, which propose that emotions are differentiated by a combination of perceptual, mnemonic, prospective, and motivational elements. Such brain-based models of emotion provide a foundation for new translational and clinical approaches. PMID:25853490

  10. Category learning in the color-word contingency learning paradigm.

    Science.gov (United States)

    Schmidt, James R; Augustinova, Maria; De Houwer, Jan

    2018-04-01

    In the typical color-word contingency learning paradigm, participants respond to the print color of words where each word is presented most often in one color. Learning is indicated by faster and more accurate responses when a word is presented in its usual color, relative to another color. To eliminate the possibility that this effect is driven exclusively by the familiarity of item-specific word-color pairings, we examine whether contingency learning effects can be observed also when colors are related to categories of words rather than to individual words. To this end, the reported experiments used three categories of words (animals, verbs, and professions) that were each predictive of one color. Importantly, each individual word was presented only once, thus eliminating individual color-word contingencies. Nevertheless, for the first time, a category-based contingency effect was observed, with faster and more accurate responses when a category item was presented in the color in which most of the other items of that category were presented. This finding helps to constrain episodic learning models and sets the stage for new research on category-based contingency learning.

  11. 75 FR 68296 - Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources...

    Science.gov (United States)

    2010-11-05

    ... Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Sewage... ``Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Sewage... performance standards for new units and emission guidelines for existing units for specific categories of...

  12. Incidental Learning of Sound Categories is Impaired in Developmental Dyslexia

    Science.gov (United States)

    Gabay, Yafit; Holt, Lori L.

    2015-01-01

    Developmental dyslexia is commonly thought to arise from specific phonological impairments. However, recent evidence is consistent with the possibility that phonological impairments arise as symptoms of an underlying dysfunction of procedural learning. The nature of the link between impaired procedural learning and phonological dysfunction is unresolved. Motivated by the observation that speech processing involves the acquisition of procedural category knowledge, the present study investigates the possibility that procedural learning impairment may affect phonological processing by interfering with the typical course of phonetic category learning. The present study tests this hypothesis while controlling for linguistic experience and possible speech-specific deficits by comparing auditory category learning across artificial, nonlinguistic sounds among dyslexic adults and matched controls in a specialized first-person shooter videogame that has been shown to engage procedural learning. Nonspeech auditory category learning was assessed online via within-game measures and also with a post-training task involving overt categorization of familiar and novel sound exemplars. Each measure reveals that dyslexic participants do not acquire procedural category knowledge as effectively as age- and cognitive-ability matched controls. This difference cannot be explained by differences in perceptual acuity for the sounds. Moreover, poor nonspeech category learning is associated with slower phonological processing. Whereas phonological processing impairments have been emphasized as the cause of dyslexia, the current results suggest that impaired auditory category learning, general in nature and not specific to speech signals, could contribute to phonological deficits in dyslexia with subsequent negative effects on language acquisition and reading. Implications for the neuro-cognitive mechanisms of developmental dyslexia are discussed. PMID:26409017

  13. Adherence to oral contraception in women on Category X medications.

    Science.gov (United States)

    Steinkellner, Amy; Chen, William; Denison, Shannon E

    2010-10-01

    Over 6% of women become pregnant when taking teratogenic medications, and contraceptive counseling appears to occur at suboptimal rates. Adherence to contraception is an important component in preventing unwanted pregnancy and has not been evaluated in this population. We undertook a pharmacy claims-based analysis to evaluate the degree to which women of childbearing age who receive Category X medications adhere to their oral contraception. We evaluated the prescription medication claims for over 6 million women, age 18-44 years, with prescription benefits administered by a pharmacy benefits manager. Women with 2 or more claims for a Category X medication and 2 or more claims for oral contraception were evaluated in further detail. Adherence to oral contraception was measured by analyzing pharmacy claims. Multivariable logistic regression was performed to identify factors associated with adherence. There were 146,758 women of childbearing age who received Category X medications, of which 26,136 also took oral contraceptive medication. Women who received Category X medications were prescribed oral contraception (18%) at rates similar to others of childbearing age (17%). Women prescribed both Category X and oral contraception demonstrated adherence similar to the overall population. Age, class of Category X medication, number of medications, prescriber's specialty, and ethnicity correlated with lower adherence rates. Despite added risk associated with unintended pregnancy, many women who receive Category X medications have refill patterns suggesting nonadherence to oral contraception. Compared with all women age 18-44 years, women receiving teratogenic medications do not have better adherence to oral contraception. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Incidental learning of sound categories is impaired in developmental dyslexia.

    Science.gov (United States)

    Gabay, Yafit; Holt, Lori L

    2015-12-01

    Developmental dyslexia is commonly thought to arise from specific phonological impairments. However, recent evidence is consistent with the possibility that phonological impairments arise as symptoms of an underlying dysfunction of procedural learning. The nature of the link between impaired procedural learning and phonological dysfunction is unresolved. Motivated by the observation that speech processing involves the acquisition of procedural category knowledge, the present study investigates the possibility that procedural learning impairment may affect phonological processing by interfering with the typical course of phonetic category learning. The present study tests this hypothesis while controlling for linguistic experience and possible speech-specific deficits by comparing auditory category learning across artificial, nonlinguistic sounds among dyslexic adults and matched controls in a specialized first-person shooter videogame that has been shown to engage procedural learning. Nonspeech auditory category learning was assessed online via within-game measures and also with a post-training task involving overt categorization of familiar and novel sound exemplars. Each measure reveals that dyslexic participants do not acquire procedural category knowledge as effectively as age- and cognitive-ability matched controls. This difference cannot be explained by differences in perceptual acuity for the sounds. Moreover, poor nonspeech category learning is associated with slower phonological processing. Whereas phonological processing impairments have been emphasized as the cause of dyslexia, the current results suggest that impaired auditory category learning, general in nature and not specific to speech signals, could contribute to phonological deficits in dyslexia with subsequent negative effects on language acquisition and reading. Implications for the neuro-cognitive mechanisms of developmental dyslexia are discussed. Copyright © 2015 Elsevier Ltd. All rights

  15. 40 CFR 433.10 - Applicability; description of the metal finishing point source category.

    Science.gov (United States)

    2010-07-01

    ..., Electrochemical Machining, Electron Beam Machining, Laser Beam Machining, Plasma Arc Machining, Ultrasonic...) Nonferrous forming (40 CFR part 471) Electrical and electronic components (40 CFR part 469) (c) This part...

  16. 75 FR 8807 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories...

    Science.gov (United States)

    2010-02-26

    ... Perchloroethylene Dry X X X X Cleaning. N Hard and Decorative X X X X Chromium Electroplating and Chromium Anodizing... Furniture X X X X Manufacturing Operations. KK Printing and Publishing X X X X Industry. LL Primary Aluminum... Primary Copper Smelting X X X RRR Secondary Aluminum X X X Production. TTT Primary Lead Smelting.. X X X...

  17. 76 FR 14807 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories...

    Science.gov (United States)

    2011-03-18

    ... Aluminum, Copper, and Other Nonferrous Foundries On December 14, 2010, EPA granted delegation to Maricopa... Electroplating and Chromium Anodizing Tanks. O Ethylene Oxide X X X X Sterilization Facilities. Q Industrial... Printing and Publishing X X X X Industry. LL Primary Aluminum X X Reduction Plants. MM Chemical Recovery X...

  18. 77 FR 41075 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories...

    Science.gov (United States)

    2012-07-12

    ... Decorative Chromium Electroplating and Chromium Anodizing Tanks. O Ethylene Oxide X X X X X Sterilization... Operations. KK Printing and X X X X X Publishing Industry. LL Primary Aluminum X X X Reduction Plants. MM... X X Production. QQQ Primary Copper X X X X Smelting. RRR Secondary X X X X Aluminum Production. TTT...

  19. 77 FR 11039 - Proposed Confidentiality Determinations for the Petroleum and Natural Gas Systems Source Category...

    Science.gov (United States)

    2012-02-24

    ... liquids (NGLs) or non-methane gases from produced natural gas, or the separation of NGLs into one or more... than or reveal the composition of the hydrocarbon equal to 10 barrels per liquid or the reporter's... composition of the hydrocarbon equal to 10 barrels per liquid or the reporter's productivity. Data on day...

  20. 75 FR 67625 - Delegation of National Emission Standards for Hazardous Air Pollutants for Source Categories...

    Science.gov (United States)

    2010-11-03

    ... Equipment Leaks--Control X X Level 2. VV Oil-Water Separators and X X Organic-Water Separators. WW Storage... Air X X Pollutants: Equipment Leaks. I Organic Hazardous Air X X Pollutants: Certain Processes Subject to the Negotiated Regulation for Equipment Leaks. J Polyvinyl Chloride and X X Copolymers Production...