WorldWideScience

Sample records for all-ceramic tubesheet assembly

  1. Evaluation of an all-ceramic tubesheet assembly for a hot gas filter

    Energy Technology Data Exchange (ETDEWEB)

    Bitner, J.L. [Mallett Technology, Inc., Canonsburg, PA (United States); Mallett, R.H. [Mallett Technology, Inc., Research Triangle Park, NC (United States); Eggerstedt, P.M. [Industrial Filter and Pump Mfg. Co., Cicero, IL (United States); Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    A 10-inch thick, all-ceramic tubesheet design is evaluated for differential pressure and thermal conditions. Primary stresses from differential pressure are well within a safe allowable. The calculated peak thermal stresses at local discontinuities approach the modules of rupture for the ceramic material. Kiln tests were performed to demonstrate differential temperatures between hot center and cooler rim do not cause failures or visible tensile cracks. There appear to be mitigating mechanisms and design features in the Industrial Filter and Pump (IF and P) Mfg. Co. all-ceramic tubesheet design concept that add forgiveness in accommodating differential pressure and thermal loading stresses. A material characterization program on the ceramic materials is recommended.

  2. Ceramic tubesheet design analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mallett, R.H.; Swindeman, R.W.

    1996-06-01

    A transport combustor is being commissioned at the Southern Services facility in Wilsonville, Alabama to provide a gaseous product for the assessment of hot-gas filtering systems. One of the barrier filters incorporates a ceramic tubesheet to support candle filters. The ceramic tubesheet, designed and manufactured by Industrial Filter and Pump Manufacturing Company (EF&PM), is unique and offers distinct advantages over metallic systems in terms of density, resistance to corrosion, and resistance to creep at operating temperatures above 815{degrees}C (1500{degrees}F). Nevertheless, the operational requirements of the ceramic tubesheet are severe. The tubesheet is almost 1.5 m in (55 in.) in diameter, has many penetrations, and must support the weight of the ceramic filters, coal ash accumulation, and a pressure drop (one atmosphere). Further, thermal stresses related to steady state and transient conditions will occur. To gain a better understanding of the structural performance limitations, a contract was placed with Mallett Technology, Inc. to perform a thermal and structural analysis of the tubesheet design. The design analysis specification and a preliminary design analysis were completed in the early part of 1995. The analyses indicated that modifications to the design were necessary to reduce thermal stress, and it was necessary to complete the redesign before the final thermal/mechanical analysis could be undertaken. The preliminary analysis identified the need to confirm that the physical and mechanical properties data used in the design were representative of the material in the tubesheet. Subsequently, few exploratory tests were performed at ORNL to evaluate the ceramic structural material.

  3. Thermal and structural analysis of a filter vessel ceramic tubesheet

    Energy Technology Data Exchange (ETDEWEB)

    Mallett, R.H. [Mallett Technology, Inc., Research Triangle Park, NC (United States); Swindeman, R.W. [Oak Ridge National Lab., TN (United States); Zievers, J.F. [Industrial Filter & Pump Mfg. Co., Cicero, IL (United States)

    1995-08-01

    A ceramic tubesheet assembly for a hot gas filter vessel is analyzed using the finite element method to determine stresses under differential pressure loading. The stresses include local concentration effects. Selection of the stress measures for evaluation of structural integrity is discussed. Specification of stress limits based upon limited data is considered. Stress results from this ongoing design analysis technology project are shown for one design concept.

  4. Prestresses in bilayered all-ceramic restorations

    NARCIS (Netherlands)

    M.N. Aboushelib; A.J. Feilzer; N. de Jager; C.J. Kleverlaan

    2008-01-01

    Introduction: A general trend in all ceramic systems is to use veneering ceramics of slightly lower thermal expansion coefficients compared with that of the framework resulting in a positive mismatch in thermal expansion coefficient (+ΔTEC). The concept behind this TEC mismatch is to generate compre

  5. Graded Structures for All-ceramic Restorations

    OpenAIRE

    Zhang, Y.; Chai, H.; Lawn, B.R.

    2010-01-01

    One failure mode of all-ceramic restorations is radial cracking at the cementation surface, from occlusally induced flexure of the stiffer ceramic layer(s) on the softer dentin underlayer. We hypothesize that such failure may be substantially mitigated by an appropriate grading of elastic modulus through the ceramic thickness. In this study, we fabricated graded structures by infiltrating glass into zirconia plates, with resulting diminished modulus in the outer surfaces. The plates were then...

  6. Graded structures for all-ceramic restorations.

    Science.gov (United States)

    Zhang, Y; Chai, H; Lawn, B R

    2010-04-01

    One failure mode of all-ceramic restorations is radial cracking at the cementation surface, from occlusally induced flexure of the stiffer ceramic layer(s) on the softer dentin underlayer. We hypothesize that such failure may be substantially mitigated by an appropriate grading of elastic modulus through the ceramic thickness. In this study, we fabricated graded structures by infiltrating glass into zirconia plates, with resulting diminished modulus in the outer surfaces. The plates were then bonded to a polymeric base and subjected to flexure by contact loading until fracture. Comparison of infiltrated specimens with non-infiltrated controls showed a significant increase in the fracture loads, by a factor of nearly 2. Finite element analysis revealed the cause of increase in the load-bearing capacity to be diminished tensile stresses within the lower-modulus graded zone, corresponding to an increase in material strength. The results confirmed that suitably graded structures can be highly beneficial in the design of next-generation all-ceramic restorations. PMID:20200413

  7. [Key points in anterior esthetic restorations with all ceramic].

    Science.gov (United States)

    Luo, Xiaoping; Qian, Dongdong; Yuan, Yu; Meng, Xiangfeng

    2013-04-01

    This paper introduced the key points in fabricating anterior esthetic restorations with all ceramic materials, including pre-operative smile design, standard tooth preparation, provisional restoration fabrication, all ceramic materials selection, all ceramic restoration bonding, ceramic crack and fracture prevention. And then, the authors summarized and reviewed the clinical common problems in anterior esthetic restorations.

  8. All-ceramic systems: laboratory and clinical performance.

    Science.gov (United States)

    Guess, Petra C; Schultheis, Stefan; Bonfante, Estevam A; Coelho, Paulo G; Ferencz, Jonathan L; Silva, Nelson R F A

    2011-04-01

    Several all-ceramic systems have been developed in dentistry to meet the increased expectations of patients and dentists for highly aesthetic, biocompatible, and long-lasting restorations. However, early bulk fractures or chippings have led the research community to investigate the mechanical performance of the all-ceramic systems. This overview explores the current knowledge of monolithic and bilayer dental all-ceramic systems, addressing composition and processing mechanisms, laboratory and clinical performance, and possible future trends for all-ceramic materials. PMID:21473997

  9. A Simple Tubesheet Layout Program for Heat Exchangers

    Directory of Open Access Journals (Sweden)

    S. Murali

    2008-01-01

    Full Text Available The development of tubesheet layout program for shell and tube heat exchangers is presented in this study. Program is written in AutoLISP language, which provides standard tubesheet layout drawing as per standard codes and non standard tubsheet in AutoCAD Environment. The program computes the optimal number of tube count and lays out drawing with respecting constraints, including the shell ID, number of passes, center to center distance of tubes and tube outer diameter. Tubesheet layout drawing can be used as template for actual tubesheet. Furthermore the program is validated with open literature and shown good agreement with it. Besides the tubesheet for Heat exchangers this method can be extended to the tube counts of sheave plates and perforated plates of distillation column and Cooling Towers.

  10. Fabrication of all-ceramic crowns by a new method.

    Science.gov (United States)

    Masuda, Takayuki; Kakimoto, Kazutoshi; Takahashi, Kazuya; Komasa, Yutaka

    2016-01-01

    A new method of all-ceramic production using alumina coping has been developed. The present study investigates the influence of secondary firing (glass infiltration firing) conditions. Samples of porcelain build-up without secondary firing were also assessed. The suitability of coping that included secondary firing was found to be affected by the rate of temperature increase during the secondary firing. However, cracking developed in the fired porcelain if porcelain was built up onto secondarily-fired coping. In contrast, cracking did not occur with coping that was not secondarily fired. The bending strength after porcelain build-up was 70 MPa or higher, suggesting the possibility of clinical applications as an anterior crown. These findings establish that this is method of producing all-ceramic crowns that allows for low-cost manufacture in a short period of about 1 h. PMID:27041020

  11. Anterior all-ceramic superstructures: chance or risk?

    Science.gov (United States)

    Rinke, Sven

    2015-03-01

    The use of zirconia abutments for single-tooth restorations is well documented and supported by clinical studies with observational periods of up to 5 years. However, data for fixed partial dentures (FPDs) on all-ceramic abutments are lacking. Therefore, this indication cannot yet be generally recommended. Based on the available clinical studies, it can be assumed that the treatment results for anterior restorations can be improved by using all-ceramic abutments, especially in situations with a reduced thickness of the peri-implant soft tissues (< 2 mm). Zirconia abutments for single-tooth restorations can be restored with glass-ceramic crowns on a lithium-disilicate base or crowns with oxide-ceramic structures (alumina or zirconia). If the restorations are cemented adhesively, then all of the cement residues must be carefully removed. Superstructures based on zirconia ceramics can be removed to a certain degree if they are cemented temporarily or screwfixed with directly veneered abutments. However, prior to providing a general recommendation for temporary cementation or screw-fixation of all-ceramic superstructures, additional clinical data are needed. PMID:25606583

  12. Restoration of Endodontically Treated Molars Using All Ceramic Endocrowns

    Directory of Open Access Journals (Sweden)

    Roopak Bose Carlos

    2013-01-01

    Full Text Available Clinical success of endodontically treated posterior teeth is determined by the postendodontic restoration. Several options have been proposed to restore endodontically treated teeth. Endocrowns represent a conservative and esthetic restorative alternative to full coverage crowns. The preparation consists of a circular equigingival butt-joint margin and central retention cavity into the entire pulp chamber constructing both the crown and the core as a single unit. The case reports discussed here are moderately damaged endodontically treated molars restored using all ceramic endocrowns fabricated using two different systems, namely, CAD/CAM and pressed ceramic.

  13. Bond strengths of all-ceramics: acid vs laser etching.

    Science.gov (United States)

    Gökçe, B; Ozpinar, B; Dündar, M; Cömlekoglu, E; Sen, B H; Güngör, M A

    2007-01-01

    Various applications of dental lasers on dental materials have been proposed for surface modifications. This study evaluated whether laser etching could be an alternative to hydrofluoric acid (HF) etching. One hundred and ten lithia-based all-ceramic specimens (Empress 2) (R: 4 mm, h: 4 mm) were prepared and divided into five groups (n = 22/group). The untreated specimens served as the control, while one of the experimental groups was treated with 9.5% HF for 30 seconds. Three remaining test groups were treated with different laser (Er:YAG laser wavelength:2940 nm, OpusDent) power settings: 300 mJ, 600 mJ and 900 mJ. Ten specimens in each group were luted to the other 10 specimens by a dual-curing cement (Variolink II), and shear-bond strength (SBS) tests were performed (Autograph, crosshead speed: 0.5 mm/minute). The results were statistically analyzed (Kruskal Wallis and Mann Whitney-U, alpha = .05). Mean SBS (MPa) were 31.9 +/- 4.0, 41.4 +/- 4.3, 42.8 +/- 6.2, 29.2 +/- 4.5 and 27.4 +/- 3.8 for the control and HF, 300, 600 and 900 mJ groups, respectively. SEM evaluations revealed different surface morphologies depending on the laser parameters. The differences between HF acid and 300 mJ, when compared with the control, 600 and 900 mJ groups, were significant (p < .05). The 300 mJ laser group exhibited the highest shear-bond strength values, indicating that laser etching could also be used for surface treatments.

  14. Corrosion inhibition of steam generator tubesheet by Alloy 690 cladding in secondary side environments

    Energy Technology Data Exchange (ETDEWEB)

    Hur, Do Haeng, E-mail: dhhur@kaeri.re.kr; Choi, Myung Sik; Lee, Deok Hyun; Han, Jung Ho; Shim, Hee Sang

    2013-11-15

    Denting is a phenomenon that a steam generator tube is distorted by a volume expansion of corrosion products of the tube support and tubesheet materials adjacent to the tube. Although denting has been mitigated by a modification of the design and material of the tube support structures, it has been an inevitable concern in the crevice region of the top of tubesheet. This paper provides a new technology to prevent denting by cladding the secondary surface of the tubesheet with a corrosion resistant material. In this study, Alloy 690 material was cladded onto the surface of an SA508 tubesheet to a thickness of about 9 mm. The corrosion rates of the original SA508 tubesheet and the Alloy 690 clad material were measured in acidic and alkaline simulated environments. Using Alloy 690 cladding, the corrosion rate of the tubesheet within a magnetite sludge pile decreased by a factor of 680 in 0.1 M NiCl{sub 2} solution at 300 °C, and by a factor of 58 in 2 M NaOH solution at 315 °C. This means that denting can drastically be prevented by cladding the secondary tubesheet surface with corrosion resistant materials.

  15. Refurbishment of packed tubesheets utilizing plastic ferrules embedded in epoxy cladding

    Energy Technology Data Exchange (ETDEWEB)

    Spires, G.V. [Advanced Corrosion Engineering, Inc., Kingwood, TX (United States); Price, K.L. [Tampa Electric Company, Tampa, FL (United States)

    1996-08-01

    Retubing a Type 316 Stainless tubesheet of the packed tube joint design with more noble super austenitic stainless steel tubes prompted galvanic corrosion of the lead elements comprising the packing. Preventing such attack in a warm seawater cooled condenser was crucial to condensate quality. The fact that the tubes move with respect to the tubesheet greatly complicated the general plan to use an epoxy coating to isolate the tube/tubesheet joints from the cooling water. This paper describes the unique solution that was used to correct the packing deterioration problem. An epoxy tubesheet overlay was applied in a manner that accommodated tube translation. This was achieved by replacing the packing with high density polyethylene (HDPE) plastic ferrules molded with integral crevical knurls which formed a seal with the tube ODs. A single new fiber packing ring behind the plastic ferrule proved critical to the success of this concept. 5 refs., 6 figs.

  16. The teaching of all-ceramic restorations in North American dental schools: materials and techniques employed.

    Science.gov (United States)

    Frazier, K B; Mjör, I A

    1997-01-01

    North American dental schools were surveyed to determine the types of clinical experiences and the extent of material use that predoctoral students encounter with restorative procedures that employ all-ceramic materials. The results were based on an overall response rate of 80% from the 64 surveyed schools. The majority (96%) of the 51 schools responding to the survey did offer an opportunity to become experienced with all-ceramic restorations. The selection of bases and liners for all-ceramic restorations included dentin adhesive agents, glass ionomer materials, and calcium hydroxide products, by a ratio of 5:4:1, respectively. The most commonly used impression material types were addition silicone and polyether. One or both of these materials were used by every school. Dicor glass ceramic and alumina core ceramic were the most commonly used materials by the responding schools for veneers, onlays, and crowns. Dicor glass ceramic and CAD/CAM ceramic were most commonly used for inlays. Crowns were made of more different all-ceramic material types than the other restoration classes. Fabrication of all-ceramic restorations was primarily by commercial laboratories and school technicians. Students have hands-on experience in the fabrication of all-ceramic restorations in 6% of the responding schools. Luting agents for all-ceramic restorations include dual-cured resin, in 96% of the responding schools, light-cured resin, 43%, and glass ionomer cement, 33%. Zinc phosphate, chemical-cured composite, and polycarboxylate were used by less than one fourth of the respondents. Only resin-based composite materials were used to lute ceramic veneers. Rubber dam was applied primarily during luting procedures involving all-ceramic inlays and onlays. Crowns and veneers were isolated by this method in less than 30% of the responding schools. Finishing procedures with all-ceramic restorations were accomplished with three or more instruments by 89% of the schools.

  17. LMFBR steam generator tube-to-tubesheet weld with dissimilar ferritic steels - qualification tests and inelastic analyses

    International Nuclear Information System (INIS)

    To weld steam-generating tubes of EM12 to a tubesheet provided with boss of 2.25 Cr. 1 Mo, STEIN INDUSTRIE has developed a process of internal welding without filler metal. The characterization tests carried out on test assemblies have shown the excellent metallurgical quality of welding performed by this process. High-temperature strength tests showed a safety margin as compared with the results of the finite element calculations. The hypotheses made for these calculations which take into account the elastoviscoplatic properties of materials, and particularly the extension of the properties of 2.25 Cr. 1 Mo to the weld, can therefore be applied to steam-generator sizing calutations. (orig.)

  18. The teaching of all-ceramic restorations in Scandinavian dental schools: a survey.

    Science.gov (United States)

    Jokstad, A; Mjör, I A; Frazier, K B

    1996-06-01

    The study was designed to survey the curricular requirements, types of clinical experience, and materials/ techniques used in teaching programs for all-ceramic restorations in Scandinavian dental schools. All 13 dental schools responded. Ten offered some clinical experience to pre-doctoral students, but only one required one all-ceramic restoration. The departments of fixed prosthodontics had the main teaching responsibility. All-ceramic crowns were taught at 9, veneers at 7, and inlays/onlays at 10 dental schools. A wide range of different teaching concepts, materials, and views on indications and contraindications was reported. It appears as if all-ceramic restorations are regarded as experimental by the teaching institutions, although the dental industry and some practitioners strongly recommend these types of restorations.

  19. Impact Behavior of Three Notched All-Ceramic Restorations after Soaking in Artificial Saliva

    OpenAIRE

    Min Yan; Chung-Kai Wei; Yuh-Yih Lin; Suh-Woan Hu; Shinn-Jyh Ding

    2015-01-01

    Biomechanics play a critical role in influencing the clinical applications of all-ceramic dental restorations. The restorative biomaterials have to demonstrate mechanical durability in the oral environment because they are always exposed to a variety of oral environments. This study was designed to evaluate the effect of soaking time, notch and saliva pH values on the impact energy of three commonly used all-ceramic materials for CAD/CAM. The leucite-reinforced glass ceramic (ProCAD), lithiu...

  20. The clinical potential and limits of the all-ceramic fixed partial denture restorations

    Directory of Open Access Journals (Sweden)

    Harry Laksono

    2007-12-01

    Full Text Available High-strength all-ceramic systems for fixed partial dentures (FPDs is gaining popularity as an alternative to the well established metal-ceramic FPDs. Several new framework materials and technique such as lithium disilicate, aluminum oxide and yttrium tetragonal zirconia polycrystal have been developed with improved strength, marginal discrepancy and esthetics. Since not every all-ceramic system can be used for a variety application, proper selection of the materials is an important for the success of all-ceramic FPDs. The longevity of dental restorations is an important health concern and the clinician placed great emphasis on mechanical properties to define the clinical indication of the ceramic materials because of their brittleness and low fracture toughness. The stronger and tougher framework material would improve the reliability and the longevity of dental restoration. To fabricated of an all-ceramic FPDs, material would be required with a flexural strength in excess of 300 MPa and fracture toughness 3 MPa/m½. Zirconium has a better mechanical properties than alumina and lithium disilicate glass-ceramic, result from the transformation toughening, free of glass phase and minimal flaws. Whereas lithium disilicate glass-ceramic has a better translucency than alumina and zirconium based ceramic, result from the higher content of glass phase than that two materials. The purpose of this article is to present the information that can guide the practioner in the decision making process about all-ceramic FPDs systems. It can be concluded that the all-ceramic FPDs are seems to be an acceptable clinically prosthodontic treatment according to the short-term studies and the lithium disilicate and alumina-based ceramic materials are acceptable for 3 units anterior FPDs, whereas zirconia-based ceramic are acceptable for 3–5 units anterior and posterior FPDs with 2 pontics. However, further investigation and more clinical long-term follow-up studies

  1. All-ceramic restorations for complete-mouth rehabilitation in dentinogenesis imperfecta: a case report.

    Science.gov (United States)

    Moundouri-Andritsakis, Heleni; Kourtis, Stephanos G; Andritsakis, Demetrios P

    2002-10-01

    Prosthetic treatment of patients with dentinogenesis imperfecta is a challenge for the dental practitioner because numerous factors have to be considered. The use of all-ceramic restorations to rehabilitate the dentition of a young patient with dentinogenesis imperfecta is reported. Clinical and laboratory procedures are described.

  2. Comparison of two bond strength testing methodologies for bilayered all-ceramics

    NARCIS (Netherlands)

    Dundar, Mine; Ozcan, Mutlu; Gokce, Bulent; Comlekoglu, Erhan; Leite, Fabiola; Valandro, Luiz Felipe

    2007-01-01

    Objectives. This study compared the shear bond strength (SBS) and microtensile (MTBS) testing methodologies for core and veneering ceramics in four types of all-ceramic systems. Methods. Four different ceramic veneer/core combinations, three of which were feldspathic and the other a fluor-apatite to

  3. Laser welding process tailored to tube-sheet joint requirements for heat exchangers manufacturing for nuclear power plants

    International Nuclear Information System (INIS)

    The aim of this work is to highlight the viability of the laser welding process to weld tuba to tube-sheet joints. The laser welding process provides higher welding speed, narrower weld beads and lower heat input than arc processes. So the laser welding process of tuba to tube-sheet joints will be able to reduce the cycle time of the welding process in heat exchangers manufacturing, reducing also thermal distortions.

  4. CAD/CAM fabricated single-unit all-ceramic post-core-crown restoration

    Directory of Open Access Journals (Sweden)

    Thilla Sekar Vinothkumar

    2011-01-01

    Full Text Available This case report explains about an innovative treatment strategy for the management of damaged anterior teeth with reduced incisal clearance by means of a single-unit all-ceramic post-core-crown zirconia ceramic restoration fabricated by Computer-aided designing and computer-aided manufacturing (CAD/CAM technology. The reinforced zirconia ceramics allow fabrication of durable esthetic restorations in cases with high functional loading and the unification of the post, core, and crown in a single unit decreases the frequency of failure by creating a monobloc effect. In addition, the use of CAD/CAM technology for designing and fabricating ceramic restorations offers the option of expeditiously preparing these high-strength all-ceramic restorations.

  5. CAD/CAM fabricated single-unit all-ceramic post–core–crown restoration

    Science.gov (United States)

    Vinothkumar, Thilla Sekar; Kandaswamy, Deivanayagam; Chanana, Pallavi

    2011-01-01

    This case report explains about an innovative treatment strategy for the management of damaged anterior teeth with reduced incisal clearance by means of a single-unit all-ceramic post–core–crown zirconia ceramic restoration fabricated by Computer-aided designing and computer-aided manufacturing (CAD/CAM) technology. The reinforced zirconia ceramics allow fabrication of durable esthetic restorations in cases with high functional loading and the unification of the post, core, and crown in a single unit decreases the frequency of failure by creating a monobloc effect. In addition, the use of CAD/CAM technology for designing and fabricating ceramic restorations offers the option of expeditiously preparing these high-strength all-ceramic restorations. PMID:21691515

  6. Design for minimizing fracture risk of all-ceramic cantilever dental bridge.

    Science.gov (United States)

    Zhang, Zhongpu; Zhou, Shiwei; Li, Eric; Li, Wei; Swain, Michael V; Li, Qing

    2015-01-01

    Minimization of the peak stresses and fracture incidence induced by mastication function is considered critical in design of all-ceramic dental restorations, especially for cantilever fixed partial dentures (FPDs). The focus of this study is on developing a mechanically-sound optimal design for all-ceramic cantilever dental bridge in a posterior region. The topology optimization procedure in association with Extended Finite Element Method (XFEM) is implemented here to search for the best possible distribution of porcelain and zirconia materials in the bridge structure. The designs with different volume fractions of zirconia are considered. The results show that this new methodology is capable of improving FPD design by minimizing incidence of crack in comparison with the initial design. Potentially, it provides dental technicians with a new design tool to develop mechanically sound cantilever fixed partial dentures for more complicated clinical situation. PMID:26405963

  7. Fracture Rates and Lifetime Estimations of CAD/CAM All-ceramic Restorations.

    Science.gov (United States)

    Belli, R; Petschelt, A; Hofner, B; Hajtó, J; Scherrer, S S; Lohbauer, U

    2016-01-01

    The gathering of clinical data on fractures of dental restorations through prospective clinical trials is a labor- and time-consuming enterprise. Here, we propose an unconventional approach for collecting large datasets, from which clinical information on indirect restorations can be retrospectively analyzed. The authors accessed the database of an industry-scale machining center in Germany and obtained information on 34,911 computer-aided design (CAD)/computer-aided manufacturing (CAM) all-ceramic posterior restorations. The fractures of bridges, crowns, onlays, and inlays fabricated from different all-ceramic systems over a period of 3.5 y were reported by dentists and entered in the database. Survival analyses and estimations of future life revealed differences in performance among ZrO2-based restorations and lithium disilicate and leucite-reinforced glass-ceramics. PMID:26428908

  8. Impact Behavior of Three Notched All-Ceramic Restorations after Soaking in Artificial Saliva

    Directory of Open Access Journals (Sweden)

    Min Yan

    2015-07-01

    Full Text Available Biomechanics play a critical role in influencing the clinical applications of all-ceramic dental restorations. The restorative biomaterials have to demonstrate mechanical durability in the oral environment because they are always exposed to a variety of oral environments. This study was designed to evaluate the effect of soaking time, notch and saliva pH values on the impact energy of three commonly used all-ceramic materials for CAD/CAM. The leucite-reinforced glass ceramic (ProCAD, lithium disilicate glass ceramic (IPS e.max CAD and zirconia-based ceramic materials (IPS e.max ZirCAD were used. The experimental results indicated that the impact energy of ProCAD decreased with an increase in soaking time, but not for IPS e.max CAD and IPS e.max ZirCAD. The impact energy of the zirconia system was higher than leucite-reinforced and lithium disilicate-based ceramic systems. When subjected to preformed 0.5 mm U-shape notch on the bar specimen of 3 mm thick, the impact energy of the all-ceramic restorations revealed a markedly reduction of about 80%–90%, almost irrespective of dental compositions, which indicated the effect of flaw to a great degree. No statistically significant influence (p > 0.05 of pH values (4, 7 and 9 on impact energy was found for each group. It is concluded that the no matter which all-ceramic materials were used, it was appreciably sensitive to the presence of notches. The ceramic composition and microstructure have been shown to affect mechanical durability.

  9. CAD/CAM fabricated single-unit all-ceramic post–core–crown restoration

    OpenAIRE

    Thilla Sekar Vinothkumar; Deivanayagam Kandaswamy; Pallavi Chanana

    2011-01-01

    This case report explains about an innovative treatment strategy for the management of damaged anterior teeth with reduced incisal clearance by means of a single-unit all-ceramic post-core-crown zirconia ceramic restoration fabricated by Computer-aided designing and computer-aided manufacturing (CAD/CAM) technology. The reinforced zirconia ceramics allow fabrication of durable esthetic restorations in cases with high functional loading and the unification of the post, core, and crown in a sin...

  10. 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.

  11. 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.

  12. Topological design of all-ceramic dental bridges for enhancing fracture resistance.

    Science.gov (United States)

    Zhang, Zhongpu; Chen, Junning; Li, Eric; Li, Wei; Swain, Michael; Li, Qing

    2016-06-01

    Layered all-ceramic systems have been increasingly adopted in major dental prostheses. However, ceramics are inherently brittle, and they often subject to premature failure under high occlusion forces especially in the posterior region. This study aimed to develop mechanically sound novel topological designs for all-ceramic dental bridges by minimizing the fracture incidence under given loading conditions. A bi-directional evolutionary structural optimization (BESO) technique is implemented within the extended finite element method (XFEM) framework. Extended finite element method allows modeling crack initiation and propagation inside all-ceramic restoration systems. Following this, BESO searches the optimum distribution of two different ceramic materials, namely porcelain and zirconia, for minimizing fracture incidence. A performance index, as per a ratio of peak tensile stress to material strength, is used as a design objective. In this study, the novel XFEM based BESO topology optimization significantly improved structural strength by minimizing performance index for suppressing fracture incidence in the structures. As expected, the fracture resistance and factor of safety of fixed partial dentures structure increased upon redistributing zirconia and porcelain in the optimal topological configuration. Dental CAD/CAM systems and the emerging 3D printing technology were commercially available to facilitate implementation of such a computational design, exhibiting considerable potential for clinical application in the future. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26444905

  13. Tube to tubesheet welding by electron beam for heat exchanger application

    International Nuclear Information System (INIS)

    The EB-process can successfully be used to weld in tubes into tubesheet also for those materials which are sensitiv to hot cracking. The range of qualified welding parameters has been evaluated based on a lot of metallographic and microanalysis inspections. To obtain reproducable and perfect welds a microcomputer controlled welding cycle is recommended using beam deflection, automatic seam tracking, beam current- and focus control. The results can be adopted to the specific conditions of mobile welding equipment with local vacuum. (orig.)

  14. Influence of the supporting die structures on the fracture strength of all-ceramic materials.

    Science.gov (United States)

    Yucel, Munir Tolga; Yondem, Isa; Aykent, Filiz; Eraslan, Oğuz

    2012-08-01

    This study investigated the influence of the elastic modulus of supporting dies on the fracture strengths of all-ceramic materials used in dental crowns. Four different types of supporting die materials (dentin, epoxy resin, brass, and stainless steel) (24 per group) were prepared using a milling machine to simulate a mandibular molar all-ceramic core preparation. A total number of 96 zirconia cores were fabricated using a CAD/CAM system. The specimens were divided into two groups. In the first group, cores were cemented to substructures using a dual-cure resin cement. In the second group, cores were not cemented to the supporting dies. The specimens were loaded using a universal testing machine at a crosshead speed of 0.5 mm/min until fracture occurred. Data were statistically analyzed using two-way analysis of variance and Tukey HSD tests (α = 0.05). The geometric models of cores and supporting die materials were developed using finite element method to obtain the stress distribution of the forces. Cemented groups showed statistically higher fracture strength values than non-cemented groups. While ceramic cores on stainless steel dies showed the highest fracture strength values, ceramic cores on dentin dies showed the lowest fracture strength values among the groups. The elastic modulus of the supporting die structure is a significant factor in determining the fracture resistance of all-ceramic crowns. Using supporting die structures that have a low elastic modulus may be suitable for fracture strength tests, in order to accurately reflect clinical conditions. PMID:21845404

  15. All- Ceramic Crown Preparation and the Remained wall Thickness of the Pulp Chamber

    Directory of Open Access Journals (Sweden)

    Mohammadzadeh Akhlaghi N.

    2012-12-01

    Full Text Available tatement of Problem: A minimally invasive method of preparation is essential to prevent tooth structure weakening and pulp irritation; especially for mandibular anterior single-tooth all-ceramic crowns. According to many investigations, one of the most important reasons of pulp injury caused by tooth preparation for different restorative procedures is reduced “remained wall thickness” (RWT. In order to protect the pulp from irritation, it is necessary to maintain a 0.5 mm of RWT.Purpose: The purpose of the present study was to evaluate the effect of all-ceramic crown preparation on pulp chamber RWT of mandibular incisors.Materials and Method: Mesiodistal and buccolingual initial images of 24 ex-tracted mandibular incisors were provided. The pulp chamber initial wall thick-nesses of buccal, lingual and proximal surfaces of cervical, 1and 2 mm above the cervical areas and also the incisal surfaces of incisal sections were measured using digital radiography and Photoshop software. After all-ceramic crown preparation, images were provided at the same initial positions. The initial and remained pulp chamber wall thicknesses were statistically evaluated and analyzed by ANOVA, paired t-test and a post hoc Tukey test.Results: Repeated measures ANOVA showed that the mean of pre- or post-preparation wall thicknesses were not significantly different for each surface at the three horizontal levels (p> 0.05. However, there were significant differences between the surfaces for each section. Comparison of pre- and post-preparation wall thicknesses revealed significant differences (p< 0.05. Proximal surfaces of cervical sections had the least RWT (0.42±0.12.Conclusion: According to the results of the present study, the least amount of initial and remained wall thicknesses of pulp chamber were related to the proximal surfaces, particularly in cervical areas. Therefore a reduction of preparation to 0.7 mm is suggested to prevent future pulp injury for

  16. Effect of Abutment Taper on the Fracture Resistance of all-Ceramic Three-unit Bridges

    OpenAIRE

    F. Gerami-Panah; H. Jalali; L. Sedighpour

    2005-01-01

    Statement of Problem: The connector area is the weakest zone of an all-ceramic fixed partial denture (FPD), where most catastrophic failures of the prostheses tend to occur.Purpose: The aim of the present study was to assess the effect of the convergence angle of abutments on the fracture resistance of three-unit fixed partial dentures made of IPSEmpress2.Materials and Methods: Forty extracted human premolars and molars were used to reproduce twenty, 3-unit fixed partial dentures, for the rep...

  17. Effect of pontic framework design on the fracture resistance of implant-supported all-ceramic fixed partial dentures

    OpenAIRE

    Ozgur Inan; Asli Secilmis; Oguz Eraslan

    2009-01-01

    Objective: The purpose of this study was to compare the fracture resistance of implant-supported all-ceramic fixed partial dentures, which have three different pontic designs. Material and Methods: Two implants were placed in a metal model simulating mandibular left second premolar and mandibular left second molar. Thirty standardized 3-unit all-ceramic fixed partial dentures with biconvex, convex or concave pontic designs were fabricated using IPS e.max system (n=10). Afterwards, specimens w...

  18. The Importance of the Lifelike Esthetic Appearance of All-Ceramic Restorations on Anterior Teeth

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    Daniela Micheline dos Santos

    2015-01-01

    Full Text Available The success of rehabilitation will not depend on just clinical procedures. A proper dental technique (ceramist is required as well as the respect for some biomimetic principles to obtain the desired final result. This study has the purpose of describing a prosthetic rehabilitation with laminate veneers and all-ceramic crowns of a patient unsatisfied with a previous esthetic treatment because of the negligence of some biomimetic principles. A 45-year-old female patient was admitted to the dental clinic complaining about the lifelike appearance of her all-ceramic restorations. Before the fabrication of new restorations, a mock-up was conducted to verify the patient’s satisfaction. A ceramist conducted all the fabrication process so that surface characterizations could be visually verified and the lifelike appearance of natural tooth could be reproduced. After the cementation procedure, the patient reported being satisfied with the lifelike appearance of the new restorations. Based on the clinical findings of the present case report, it can be concluded that the reproduction of the lifelike esthetic appearance of natural teeth and the visualization of the final results before definitive procedures are essential to obtain the clinical success.

  19. Effect of Zirconia Thickness on the Tensile Stress of Zirconia Based All-Ceramic Restorations

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    Masood Shiezadeh

    2015-09-01

    Full Text Available Introduction: The purpose of the presented study was to evaluate the effect of zirconia thickness on the tensile stress of zirconia based all-ceramic restorations. Methods: Twenty zirconia disks with 10mm diameter were prepared in two groups using CAD/CAM system. The thickness of zirconia was 0.5mm in first group and 0.3mm in second group. After sintering, 0.4mm glass ceramic porcelain was applied to each disk. Then, sintering and glazing of porcelain carried out. Instron testing machine with 1mm/min crosshead speed used to evaluate the failure load of the samples. Biaxial Flexural strength standard formula employed to calculate tensile stress of specimens. Statistical analysis performed using SPSS software. Results: Although data analysis showed more maximum tensile stress in 1st group, no significant differences were found between two groups. Conclusion: Zirconia with 0.5mm and 0.3mm thicknesses cause similar tensile stress in all-ceramic restorations and thickness of these laminates could be reduced to 0.7mm.

  20. Micro-CT evaluation of the marginal fit of CAD/CAM all ceramic crowns

    Science.gov (United States)

    Brenes, Christian

    Objectives: Evaluate the marginal fit of CAD/CAM all ceramic crowns made from lithium disilicate and zirconia using two different fabrication protocols (model and model-less). METHODS: Forty anterior all ceramic restorations (20 lithium disilicate, 20 zirconia) were fabricated using a CEREC Bluecam scanner. Two different fabrication methods were used: a full digital approach and a printed model. Completed crowns were cemented and marginal gap was evaluated using Micro-CT. Each specimen was analyzed in sagittal and trans-axial orientations, allowing a 360° evaluation of the vertical and horizontal fit. RESULTS: Vertical measurements in the lingual, distal and mesial views had and estimated marginal gap from 101.9 to 133.9 microns for E-max crowns and 126.4 to 165.4 microns for zirconia. No significant differences were found between model and model-less techniques. CONCLUSION: Lithium disilicate restorations exhibited a more accurate and consistent marginal adaptation when compared to zirconia crowns. No statistically significant differences were observed when comparing model or model-less approaches.

  1. [Long-term clinical results with Procera AllCeram full-ceramic crowns].

    Science.gov (United States)

    Galindo, Martha L; Hagmann, Edgar; Marinello, Carlo P; Zitzmann, Nicola U

    2006-01-01

    The aim of this prospective clinical study was to investigate the long-term survival rate of Procera AllCeram full-ceramic crowns, which were fabricated with aluminiumoxide cores. In 50 patients, 155 Procera crowns with a conventional or reduced core (porcelain collar) were placed on natural abutment teeth. 78% of this group (39 patients with 135 crowns) were examined between May and August 2005 according to the modified USPHS-Criteria. These crowns had been in place for a period of one to 92 months (mean 55 months). Almost half of the crowns were located in the molar region, while 28% were premolars and 24% anterior crowns. Due to one crown fracture the cumulative survival rate was 99% after five and seven years. The clinical success was achieved irrespective of the tooth position, tooth vitality, the preparation margin and the cementum medium used (composite resin or glasionomer cement). In addition, survival was neither influenced by the core design with reduced or conventional margin nor by the core thickness, which measured regularly 0.6 mm in the majority of the specimens. Based on the present findings, it can be concluded that Procera AllCeram is a predictable technique for metal-free, esthetic full-ceramic crowns in the anterior and posterior region. PMID:16989114

  2. A comparison between the effect of All-Ceramic and metal-ceramic restorations on the plaque accumulation

    Directory of Open Access Journals (Sweden)

    Ezatollah Jalalian

    2015-07-01

    Full Text Available Background and Aims: Tooth crowning often leads to changes in periodontal index through changes in emergence profile zone. The purpose of this study was to compare the effect of metal-ceramic with that ofAll-Ceramic restorations on the plaque a accumulation.   Materials and Methods: In this clinical trial, we used 102 teeth covered with metal-ceramic and all-ceramic restorations. Before and after crowning, plaque index (PI and gingival indexes (MGl were measured. Data were analyzed using covariance (ANCOVA test.   Results: Measured PI and MGI (Mean±SD in PFM Group prior to crowning were (1.96±0.38 and (1.45±0.48, respectively. In metal-ceramic restorations group, six months after crowning, measured PI and MGI (Mean±SD were (1.22±0.49 and (1.82±0.61, respectively. Measured PI and MGI (Mean±SD in All-Ceramic Group prior to crowning were (1.22±0.52 and (1.25±0.29, respectively. In All-Ceramic, six months after crowning, measured PI and MGI (Mean±SD were (0.88±0.51 and (1.43±0.50, respectively. ANOVA test showed statistical significance difference between metal-ceramic and All-Ceramic Groups in Indexes (P<0.001.   Conclusion: Metal-ceramic and All-Ceramic crowns were associated with inflammatory changes in gingival. Metal-ceramic restorations were associated with higher inflammatory indexes compared with All-Ceramic crowns.

  3. High-definition radiography of tube-to-tubesheet welds of steam generator of prototype fast breeder reactor

    International Nuclear Information System (INIS)

    In the steam generator of the Prototype Fast Breeder Reactor (PFBR), steam is generated by the transfer of heat from secondary sodium to water. Due to the inherent dangers of sodium-water reaction, the integrity of weld joints separating sodium and water/steam is of paramount importance. This is particularly true and very important for the tube-to-tubesheet joints. This paper discusses the use of projective magnification technique by microfocal radiography for the quality evaluation and optimisation of the welding parameters of such small tube-to-tubesheet welds of the steam generator of PFBR. (author)

  4. Thermal shock resistance of core reinforced all-ceramic crown systems.

    Science.gov (United States)

    Mora, G P; O'Brien, W J

    1994-02-01

    The coefficient of thermal expansion of core and veneer porcelains for all ceramic crowns must be compatible to prevent formation of stresses during the firing cycles. The purpose of this study was to use a thermal shock test to evaluate the crazing resistance of six all-ceramic crown systems. The systems tested were: Vita In-Ceram, Vita Hi-Ceram, Dicor veneered with Vitadur N, magnesia core veneered with Ceramco II, magnesia core veneered with Silhouette, and magnesia core veneered with Vita VMK 68. A maxillary central incisor was prepared with 1.0 mm axial and 1.5 mm incisal reduction. Refractory dies were prepared and crowns were fabricated using the manufacturers' recommendations. Six specimens of each system were placed inside a beaker in a furnace at 90 degrees C. After 15 min heat soak, ice water was poured into the beaker through a funnel. The samples were dried in air, reheated, and inspected for crazing using light microscopy. If crazing was observed, this would constitute a failure at a temperature difference (delta T) of 90 degrees C. If no failure occurred, the test was repeated at increasing temperature increments of 10 degrees C until failure. The crazing resistance of each system, expressed as the mean delta T, was: > 200 (Hi-Ceram), 163 +/- 14 (In-Ceram), 152 +/- 19 (Dicor/Vitadur N), 143 +/- 5 (magnesia core/Vita VMK 68), 122 +/- 21 (magnesia core/Silhouette), and 118 +/- 10 (magnesia core/Ceramco II) degrees C. All systems tested resisted crazing due to quenching in ice cold water from 100 degrees C. Systems with lower coefficients of expansion showed significantly greater resistance to thermal shock using ANOVA. PMID:8207030

  5. Development of LABGENE's steam generators tube to tubesheet welding qualification procedure

    International Nuclear Information System (INIS)

    The welding qualification procedure of LABGENE's Nuclear Electric Generation Laboratory - Steam Generators has special characteristics due to nuclear class 1 requirements, reduced dimensions of the LABGENE's equipment and combination of the materials involved with the tube to tubesheet welding. The welding procedure was performed using an automatic orbital welding machine without material addition. The weld joint was simulated using a sample made of a tube (ext. 12,7 BWG 18 x 90 mm) in SB-163 N08800 material and a plate (48 x 330 x 55 mm) in 20MnMoNi55 material, covered with 8 mm AWS E NiCrFe-3 cladding. For the development of the welding procedure, a lot of welding simulations were performed using machines and special devices designed for the dimensions of the pieces. Procedures related with operating, handling and cleaning conditions, essential to avoid the contamination of the pieces were issued. It was also developed a mixture of gases which contributed for the homogenising of the welding and also to avoid the appearance of cracks and defects on the weld joint. The results obtained with the performed tests fulfilled the requirements of the applied specifications and standards. The welding procedure was developed testing a lot of specimens removed from samples that were representatives of the equipment's tube to tubesheet welding. (author)

  6. Marginal fit of implant-supported all-ceramic zirconia frameworks.

    Science.gov (United States)

    Zaghloul, Hanaa Hassan; Younis, Jihan Farouk

    2013-08-01

    This study evaluated the effect of fabrication techniques and cyclic loading on the vertical marginal fit of implant-supported fixed partial denture (FPD) frameworks. Thirty implant-supported 3-unit FPD frameworks were fabricated on a model system, divided into 3 equal groups (n = 10). The first group (control) was constructed from base metal alloy; the other 2 test groups were constructed from all-ceramic zirconia using a computer-aided design/computer-aided manufacturing (CAD/CAM) Cerec 3 system and a copy milling (Zirkonzahn) system. A cyclic load of 200 N was applied to each framework for up to 50,000 cycles. Linear measurements were made in micrometers of the vertical gap between the framework and the implant-supported abutment at 16 predetermined points before and after cyclic loading. The frameworks were viewed using scanning electron microscopy to inspect any fractographic features. One-way analysis of variance was performed to compare the marginal discrepancy values of the control and the 2 test groups and for each group; a t test was applied to determine whether significant changes in the fit were observed after cyclic loading (α = 0.05). The CAD/CAM group showed significantly higher marginal gap mean values (80.58 μm) than the Zirkonzahn and control groups (50.33 μm and 42.27 μm, respectively) with no significant difference. After cyclic loading, the CAD/CAM group recorded the highest marginal gap mean value (91.50 ± 4.260 μm) followed by control group (72.00 ± 2.795 μm); the Zirkonzahn group recorded the lowest marginal gap (65.37 ± 6.138 μm). Cyclic loading significantly increased the marginal gap mean values in the control group only. A marginal chip was observed in one of the CAD/CAM ceramic frameworks. Within the limitations of this study, the fabrication technique influenced the marginal fit of the implant-supported 3-unit FPD frameworks. Cyclic loading failed to change the fit of all-ceramic zirconia frameworks, whereas significant

  7. Effect of Abutment Taper on the Fracture Resistance of all-Ceramic Three-unit Bridges

    Directory of Open Access Journals (Sweden)

    F. Gerami-Panah

    2005-12-01

    Full Text Available Statement of Problem: The connector area is the weakest zone of an all-ceramic fixed partial denture (FPD, where most catastrophic failures of the prostheses tend to occur.Purpose: The aim of the present study was to assess the effect of the convergence angle of abutments on the fracture resistance of three-unit fixed partial dentures made of IPSEmpress2.Materials and Methods: Forty extracted human premolars and molars were used to reproduce twenty, 3-unit fixed partial dentures, for the replacement of second premolars. All teeth were prepared according to the guidelines outlined for all-ceramic crowns and bridges, except for the convergence angles of the abutments. The specimens were randomly divided into two groups of 10, with total occlusal convergence angles of 12° and 22°. Fixed partial dentures with a uniform thickness of 0.8 mm were fabricated using IPS-Empress2 and were bonded to the corresponding models. Connectordimensions were set to 4 mm height and 4mm width. The radius of curvature at the gingival embrasure was carved to 0.9 mm. All specimens were exposed to 10,000 preloading cycles and a load of 40 N at a frequency of 1.3 Hz in a standardized testing machine at a cross head speed of 1mm/min. Student t-test was performed to detect any difference in the mean fracture resistance between the two groups (α = 0.05.Results: Mean failure loads (and standard deviations of the 12° and 22° groups were 1009.12 N (208.05 and 1182.72 N (144.67, respectively. Statistical analysis revealed a significant difference (P <0.04 between the mean failure loads of the two groups. Mostfractures occurred through the connectors.Conclusion: The mean failure loads of the investigated fixed partial dentures were higher in the abutments with 22° taper as compared to those with a taper of 12°.

  8. Seam-welded titanium tube as well as titanium tubesheet for all-titanium condenser of power plants

    International Nuclear Information System (INIS)

    Most of the thermal and nuclear power plants in Japan are located on the coast line, and steam turbine condenser and heat exchanger use a great quantity of sea water for cooling. This paper describes about thin wall welded tube for all-titanium condenser, development of technology for manufacturing titanium tubesheet, and the present situation of application

  9. Students’ evaluation of preclinical simulation for all ceramic preparation (In Faculty of Dentistry Universiti Kebangsaan Malaysia

    Directory of Open Access Journals (Sweden)

    Natasya Ahmad Tarib

    2008-06-01

    Full Text Available The purpose of the study is to evaluate all ceramic crown (ACC preparations those were made by dental undergraduate students during the preclinical sessions. 104 plastic teeth were prepared by 4th year dental undergraduates during the preclinical session for ACC crown examined. The teeth were placed on the frasaco arches and were mounted in the frasaco head. The preparations were examined for the tapering, presence of undercuts, incisal and cingulum reductions as well as preparation of shoulder margin. Preparations were examined using hand instruments and visual. The sample size was 92 plastic teeth. Most of the preparations were acceptable with acceptable placement and types of margins, adequate axial and incisal reductions and acceptable tapered of the axial walls. On the other hand, most of the teeth showed absence of cingulum wall. Most of the crowns prepared by the students were acceptable. It showed that they understood the principles of crown preparation. Cingulum wall preparation has to be given greater emphasis as it is important in the retention and resistance of the restoration.

  10. Modified Y-TZP core design improves all-ceramic crown reliability.

    Science.gov (United States)

    Silva, N R F A; Bonfante, E A; Rafferty, B T; Zavanelli, R A; Rekow, E D; Thompson, V P; Coelho, P G

    2011-01-01

    This study tested the hypothesis that all-ceramic core-veneer system crown reliability is improved by modification of the core design. We modeled a tooth preparation by reducing the height of proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. The CAD-based tooth preparation was replicated and positioned in a dental articulator for core and veneer fabrication. Standard (0.5 mm uniform thickness) and modified (2.5 mm height lingual and proximal cervical areas) core designs were produced, followed by the application of veneer porcelain for a total thickness of 1.5 mm. The crowns were cemented to 30-day-aged composite dies and were either single-load-to-failure or step-stress-accelerated fatigue-tested. Use of level probability plots showed significantly higher reliability for the modified core design group. The fatigue fracture modes were veneer chipping not exposing the core for the standard group, and exposing the veneer core interface for the modified group.

  11. Influence of marginal fit and cement types on microleakage of all-ceramic crown systems

    Directory of Open Access Journals (Sweden)

    Ece Yüksel

    2011-06-01

    Full Text Available The purpose of this study was to evaluate the effects of both marginal fit and cementing with different luting agents on the microleakage of all-ceramic crown systems. Thirty-six extracted upper central incisors were prepared for full-coverage crowns and were divided into three groups. Group 1: CAD/CAM-fabricated ZrO2, Group 2: Heat-pressed lithium-disilicate, and Group 3: Cast Cr-Co copings as the control group. Copings were made following standard techniques, and groups were assigned cementation with either self-adhesive resin cement (A or glass-ionomer luting cement (B. The specimens were subjected to thermocycling, immersed in basic fuchsin solution, sectioned mesiodistally and buccolingually. The surface of each section was digitally photographed under a stereomicroscope. Microleakage was scored using a five-point scale, and the marginal gap was measured using image analysis software. Data were statistically analyzed using 2-way ANOVA, Kruskal-Wallis, and Mann-Whitney U tests (α: 0.05. The marginal discrepancy of each group was 82.7 ± 7 µm, 92.6 ± 4 µm and 96.5 ± 7 µm respectively. Group 1 showed significantly smaller gaps than Group 3 (P = 0.042. Self-adhesive resin cement (A showed a lower level of microleakage than glass-ionomer luting cement (B in all groups (P = 0.029. Microleakage scores of '0' were 83% for 1A, 50% for 1B, 50% for 2A, 16% for 2B, 33% for 3A and none for 3B. Marginal discrepancy and cement type both had significant effects on microleakage. Lower levels of microleakage were recorded with self-adhesive resin cement, while CAD/CAM-fabricated ZrO2 copings showed smaller marginal discrepancy and less microleakage in comparison to cast Cr-Co.

  12. Biaxial flexural strength of Turkom-Cera core compared to two other all-ceramic systems

    Directory of Open Access Journals (Sweden)

    Bandar Mohammed Abdullah Al-Makramani

    2010-12-01

    Full Text Available Advances in all-ceramic systems have established predictable means of providing metal-free aesthetic and biocompatible materials. These materials must have sufficient strength to be a practical treatment alternative for the fabrication of crowns and fixed partial dentures. OBJECTIVES: The aim of this study was to compare the biaxial flexural strength of three core ceramic materials. MATERIAL AND METHODS: Three groups of 10 disc-shaped specimens (16 mm diameter x 1.2 mm thickness - in accordance with ISO-6872, 1995 were made from the following ceramic materials: Turkom-Cera Fused Alumina [(Turkom-Ceramic (M Sdn Bhd, Puchong, Selangor, Malaysia], In-Ceram (Vita Zahnfabrik, Bad Säckingen, Baden-Württemberg, Germany and Vitadur-N (Vita Zahnfabrik, Bad Säckingen, Baden-Württemberg, Germany, which were sintered according to the manufacturer's recommendations. The specimens were subjected to biaxial flexural strength test in an universal testing machine at a crosshead speed of 0.5 mm/min. The definitive fracture load was recorded for each specimen and the biaxial flexural strength was calculated from an equation in accordance with ISO-6872. RESULTS: The mean biaxial flexural strength values were: Turkom-Cera: 506.8±87.01 MPa, In-Ceram: 347.4±28.83 MPa and Vitadur-N: 128.7±12.72 MPa. The results were analyzed by the Levene's test and Dunnett's T3 post-hoc test (SPSS software V11.5.0 for Windows, SPSS, Chicago, IL, USA at a preset significance level of 5% because of unequal group variances (P<0.001. There was statistically significant difference between the three core ceramics (P<0.05. Turkom-Cera showed the highest biaxial flexural strength, followed by In-Ceram and Vitadur-N. CONCLUSIONS: Turkom-Cera core had significantly higher flexural strength than In-Ceram and Vitadur-N ceramic core materials.

  13. Fracture resistance of teeth restored with all-ceramic inlays and onlays: an in vitro study.

    Science.gov (United States)

    Saridag, S; Sevimay, M; Pekkan, G

    2013-01-01

    Fracture resistance of inlays and onlays may be influenced by the quantity of the dental structure removed and the restorative materials used. The purpose of this in vitro study was to evaluate the effects of two different cavity preparation designs and all-ceramic restorative materials on the fracture resistance of the tooth-restoration complex. Fifty mandibular third molar teeth were randomly divided into the following five groups: group 1: intact teeth (control); group 2: inlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press, Ivoclar Vivadent AG, Schaan, Liechtenstein); group 3: inlay preparations, zirconia ceramic (ICE Zirkon, Zirkonzahn SRL, Gais, Italy); group 4: onlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press); and group 5: onlay preparations, zirconia ceramic (ICE Zirkon). The inlay and onlay restorations were adhesively cemented with dual polymerizing resin cement (Variolink II, Ivoclar Vivadent AG). After thermal cycling (5° to 55°C × 5000 cycles), specimens were subjected to a compressive load until fracture at a crosshead speed of 0.5 mm/min. Statistical analyses were performed using one-way analysis of variance and Tukey HSD tests. The fracture strength values were significantly higher in the inlay group (2646.7 ± 360.4) restored with lithium-disilicate glass-ceramic than those of the onlay group (1673.6 ± 677) restored with lithium-disilicate glass-ceramic. The fracture strength values of teeth restored with inlays using zirconia ceramic (2849 ± 328) and onlays with zirconia ceramic (2796.3 ± 337.3) were similar to those of the intact teeth (2905.3 ± 398.8). In the IPS e.max Press groups, as the preparation amount was increased (from inlay to onlay preparation), the fracture resistance was decreased. In the ICE Zirkon ceramic groups, the preparation type did not affect the fracture resistance results.

  14. Internal fit of two all-ceramic systems and metal-ceramic crowns

    Directory of Open Access Journals (Sweden)

    Leandro Moura Martins

    2012-04-01

    Full Text Available OBJECTIVES: The aim of this study was to investigate the internal fit (IF of glass-infiltrated alumina (ICA - In-Ceram Alumina, yttria-stabilized tetragonal zirconia polycrystals (Y-TZP - IPS e.max ZirCAD, and metal-ceramic (MC - Ni-Cr alloy crowns. MATERIAL AND METHODS: Sixty standardized resin-tooth replicas of a maxillary first molar were produced for crown placement and divided into 3 groups (n=20 each according to the core material used (metal, ICA or Y-TZP. The IF of the crowns was measured using the replica technique, which employs a light body polyvinyl siloxane impression material to simulate the cement layer thickness. The data were analyzed according to the surfaces obtained for the occlusal space (OS, axial space (AS and total mean (TM using two-way ANOVA with Tukey ’s multiple comparison test (p<0.05. RESULTS: No differences among the different areas were detected in the MC group. For the Y-TZP and ICA groups, AS was statistically lower than both OS and TM. No differences in AS were observed among the groups. However, OS and TM showed significantly higher values for ICA and Y-TZP groups than MC group. Comparisons of ICA and Y-TZP revealed that OS was significantly lower for Y-TZP group, whereas no differences were observed for TM. CONCLUSIONS: The total mean achieved by all groups was within the range of clinical acceptability. However, the metal-ceramic group demonstrated significantly lower values than the all-ceramic groups, especially in OS.

  15. Design and manufacture of tube to tubesheet joints of steam generator for 500 MWe Prototype Fast Breeder Reactor

    International Nuclear Information System (INIS)

    Prototype Fast Breeder Reactor (PFBR) is 500 MWe pool type sodium cooled fast reactor. Presently this reactor is at advanced stage of construction at Kalpakkam. The main function of the steam generator is to extract the reactor heat through secondary sodium system and convert the feed water into superheated steam in the tubes of steam generators. The steam generator is a vertical shell and tube type heat exchanger with liquid sodium in the shell side and water/steam in the tube side. Operating experience of FBRs have shown that steam generator (SG) holds the key to commercial success of such reactors. Tube leakage is a serious problem and the prevention of sodium water reaction incident in the SG is essential to maintain the plant availability. In case of crack/failure in tube, high pressure water/steam reacts with shell side sodium and results in exothermic reaction with evolution of hydrogen, corrosive reaction products and intense local heat depending on leak size. This high reactive nature of sodium with water/steam requires that sodium to water/steam boundaries of steam generators must possess a high degree of reliability against failure. This is achieved in design and manufacturing by maximising the tube integrity and more importantly by proper selection of tube to tubesheet joint configuration. The principal material of construction of SG is Modified 9Cr-1Mo steel. The tubes are seamless and produced by electric arc melting followed by Electro Slag Refining (ESR) with tight control on inclusion content. Ultrasonic and eddy current testing is done on entire tube length in accordance with ASME SEC III Class I. Long seamless tubes (each 23m) are used in order to reduce the number of tube to tubesheet welds.Each SG has 547 tubes and there are 9 SG in the reactor including one spare module. There is no tube to tube joint as the aim is to minimise the number of welds to increase reliability.Tube to tubesheet joint selected for PFBR steam generator is of internal

  16. Method for calculating Average Temperature of Tubesheet in Heat Exchanger with Dual Tubesheets%双管板换热器管板平均金属温度的一种计算方法

    Institute of Scientific and Technical Information of China (English)

    袁博; 许学斌; 陈仓社

    2016-01-01

    Numerical simulation of heat transfer performance for the tubesheet and its adjacent fluid area in dual tubesheet heat exchanger was carried out in this article by using software Fluent. With heat transfer model established, the heat transfer mechanism was studied. The heat transfer equation was then provided and the method for calculating average metal temperature of tubesheet was proposed. It was shown that the simulation result was coincident with theoretical solution. Thus the correctness of heat transfer equation has been verified by simulation result.%利用FLUENT软件对双管板换热器管板及其邻近流体区域的传热特性进行了数值模拟研究,通过建立传热模型,对其传热机理进行了研究,给出了描述其传热过程的传热方程,提出了管板平均金属温度的计算方法。结果表明:管板平均金属温度的模拟结果与理论解相符,模拟结果验证了传热方程的正确性。

  17. Estimation of the reliability of all-ceramic crowns using finite element models and the stress-strength interference theory.

    Science.gov (United States)

    Li, Yan; Chen, Jianjun; Liu, Jipeng; Zhang, Lei; Wang, Weiguo; Zhang, Shaofeng

    2013-09-01

    The reliability of all-ceramic crowns is of concern to both patients and doctors. This study introduces a new methodology for quantifying the reliability of all-ceramic crowns based on the stress-strength interference theory and finite element models. The variables selected for the reliability analysis include the magnitude of the occlusal contact area, the occlusal load and the residual thermal stress. The calculated reliabilities of crowns under different loading conditions showed that too small occlusal contact areas or too great a difference of the thermal coefficient between veneer and core layer led to high failure possibilities. There results were consistent with many previous reports. Therefore, the methodology is shown to be a valuable method for analyzing the reliabilities of the restorations in the complicated oral environment.

  18. Full Contoured Tooth-Implant Supported 3-Pointic All-Ceramic Denture During Occlusal Load Transfer in Lateral Region

    Directory of Open Access Journals (Sweden)

    Żmudzki J.

    2016-06-01

    Full Text Available Implant and a tooth supported dentures are avoided by dentists because of uneven distribution of occlusal loads between a stiffer implant and a more pliable tooth. The hypothesis was that a 3-point all-ceramic bridge supported on a natural second premolar tooth and a two-pieces typical implant bears safely mastication loads. The finite element analysis showed that the implant splinted by all-ceramic zirconium bridge with the second premolar was safe under lateral mastication load, but there was found an overload at wide zone of bone tissue around the implant under the load of 800 N. The patients can safely masticate, but comminution of hard food should be avoided and they should be instructed that after such an indiscretion they need to contact a dental professional, because, in spite of integrity of the prosthesis, the bone tissue around the implant may fail and there is a hazard of intrusion of the tooth.

  19. Comparison of Fracture Toughness of All-Ceramic and Metal–Ceramic Cement Retained Implant Crowns: An In Vitro Study

    OpenAIRE

    Rao, S.; Chowdhary, R.

    2014-01-01

    To evaluate the fracture toughness of cement-retained implant-supported metal–ceramic molar crown with that of all-ceramic crowns, fabricated using IPS Empress 2 and yttria-stabilized zirconia copings. An dental implant and abutment was embedded in a clear polymethyl methacrylate model. A wax pattern reproducing the anatomy and dimension of a mandibular molar was made using inlay wax. Copings were made from the manufacturers guidelines for zirconia, metal ceramic and empress crown, in total o...

  20. Internal bore welding of 2/one quarter/Cr-1 Mo steel tube-to-tubesheet joints

    International Nuclear Information System (INIS)

    The most critical weldments in the steam supply system for a liquid metal fast breeder reactor are those that join the steam generator tubes to the tube-sheets. A modified internal welding tip with a Ta 10% W collet as well as a fused quartz gas cup was used. The pressure differential between the inside and outside of tubular welds (determined with a water manometer) is critical in controlling weld bead geometry. 8 refs

  1. Effect of pontic framework design on the fracture resistance of implant-supported all-ceramic fixed partial dentures

    Directory of Open Access Journals (Sweden)

    Ozgur Inan

    2009-10-01

    Full Text Available OBJECTIVE: The purpose of this study was to compare the fracture resistance of implant-supported all-ceramic fixed partial dentures, which have three different pontic designs. MATERIAL AND METHODS: Two implants were placed in a metal model simulating mandibular left second premolar and mandibular left second molar. Thirty standardized 3-unit all-ceramic fixed partial dentures with biconvex, convex or concave pontic designs were fabricated using IPS e.max system (n=10. Afterwards, specimens were centrally loaded on the pontics until failure with a universal testing machine. Results were analyzed by Kruskal-Wallis and Mann-Whitney U tests at 5% significance level. RESULTS: The fracture resistance values of all-ceramic fixed partial dentures designed with biconvex, convex or concave pontics were 349.71, 438.20 and 300.78 N, respectively. There were no statistically significant differences between the fracture resistances of the groups (p>0.05, except for convex and concave groups (p<0.05 and p=0.009, respectively. CONCLUSIONS: Convex design showed the best mechanical properties as demonstrated by the high values of fracture resistance.

  2. ALL-CERAMIC AND PORCELAIN-FUSED-TO-METAL FIXED PARTIAL DENTURES: A COMPARATIVE STUDY BY 2D FINITE ELEMENT ANALYSES

    OpenAIRE

    Andréa Barreira Motta; Luiz Carlos Pereira; da Cunha, Andréia R.C.C

    2007-01-01

    All-ceramic fixed partial dentures (FPDs) have an esthetic approach for oral rehabilitation. However, metal-ceramic FPDs are best indicated in the posterior area where the follow-up studies found a lower failure rate. This 2D finite element study compared the stress distribution on 3-unit all-ceramic and metal-ceramic FPDs and identified the areas of major risk of failure. Three FPD models were designed: (1) metal-ceramic FPD; (2) All-ceramic FPD with the veneering porcelain on the occlusal a...

  3. Laser all-ceramic crown removal and pulpal temperature--a laboratory proof-of-principle study.

    Science.gov (United States)

    Rechmann, P; Buu, N C H; Rechmann, B M T; Finzen, F C

    2015-11-01

    The objective of this proof-of-principle laboratory pilot study was to evaluate the temperature increase in the pulp chamber in a worst case scenario during Er:YAG laser debonding of all-ceramic crowns. Twenty extracted molars were prepared to receive all-ceramic IPS E.max CAD full contour crowns. The crowns were bonded to the teeth with Ivoclar Multilink Automix. Times for laser debonding and temperature rise in the pulp chamber using micro-thermocouples were measured. The Er:YAG was used with 560 mJ/pulse. The irradiation was applied at a distance of 5 mm from the crown surface. Additional air-water spray for cooling was utilized. Each all-ceramic crown was successfully laser debonded with an average debonding time of 135 ± 35 s. No crown fractured, and no damage to the underlying dentin was detected. The bonding cement deteriorated, but no carbonization at the dentin/cement interface occurred. The temperature rise in the pulp chamber averaged 5.4° ± 2.2 °C. During 8 out of the 20 crown removals, the temperature rise exceeded 5.5 °C, lasting 5 to 43 s (average 18.8 ± 11.6 s). A temperature rise of 11.5 °C occurred only once, while seven times the temperature rise was limited to 6.8 ± 0.5 °C. Temperature rises above 5.5 °C occurred only when the laser was applied from one side and additional cooling from the side opposite the irradiation. Er:YAG laser energy can successfully be used to efficiently debond all-ceramic crowns from natural teeth. Temperature rises exceeding 5.5 °C only occur when an additional air/water cooling from a dental syringe is inaccurately directed. To avoid possible thermal damage and to allow further heat diffusion, clinically temperature-reduced water might be applied.

  4. Internal welding of tube-to-tubesheet joints of steam generator for sodium-cooled fast breeder reactor

    International Nuclear Information System (INIS)

    In the steam generator for a sodium-cooled fast breeder reactor, there are many joints of tubes and tube sheets. For the internal welding of small diameter, thick walled tubes and tubesheets, welding method has been developed, which gives high quality welding with good reproducibility. In this method, the pressure of shield gas is controlled suitably, and consideration is given to the composition of the shield gas. As a means to ensure the quality of welds, the technique of internal radiographic test has also been established. Both the welding method and the test were able to be applied successfully to the steam generator of practical size. (Mori, K.)

  5. Helium mass spectrometry leak inspection of steam generator tube-to-tubesheet welds using the accumulation method

    International Nuclear Information System (INIS)

    A test has been developed utilizing the Helium Mass Spectrometry Accumulation Method to test steam generator tube-to-tubesheet welds. The test utilizes a chamber with an external circulation system which minimizes accumulation time and allows for higher test sensitivity. In addition to the higher leak rate sensitivity, the helium leak test is less hazardous than the conventional bubble immersion test which requires high gas pressures. This test was employed on two S6W Steam Generators, which were manufactured for use in the primary power loop of the Navy's Seawolf Nuclear Submarine

  6. 全瓷修复材料的老化性研究%Research on the Aging of All-ceramics Restoration Materials

    Institute of Scientific and Technical Information of China (English)

    张东姣

    2011-01-01

    全瓷修复材料以良好的美学特性、生物相容性和机械性能在临床上得到了广泛的应用,但全瓷冠桥在复杂的口腔环境下常出现老化现象,致使全瓷材料的颜色及机械性能产生变化.研究全瓷材料的老化现象及其规律可为临床全瓷冠桥的可靠性和耐久性评价及其改进提供有效的理论依据.本文就全瓷材料的老化现象对其颜色和机械性能的影响及影响老化的因素作一综述和评价.%All-ceramic crowns and bridges have been widely used for dental restorations owing to their excellent func-tionalityt aesthetics and biocompatibility. However, the premature clinical failure of all-ceramic crowns and bridges may easily occur when they are subjected to the complex environment of oral cavity. In the oral environment, all-ceramic materials are prone to aging. Aging can lead all-ceramic materials to change color, to lower bending strength, and to reduce anti-fracture toughness. There are many factors affecting the aging of the all-ceramic materials, for example, the grain size, the type of stabilizer, the residual stress and the water environment. In order to analyze the aging behavior, to optimize the design of all-ceramic crowns and bridges, and to evaluate the reliability and durability, we review in this paper recent research progress of aging behavior for all-ceramics restoration materials.

  7. All-ceramic and porcelain-fused-to-metal fixed partial dentures: a comparative study by 2D finite element analyses

    Directory of Open Access Journals (Sweden)

    Andréa Barreira Motta

    2007-10-01

    Full Text Available All-ceramic fixed partial dentures (FPDs have an esthetic approach for oral rehabilitation. However, metal-ceramic FPDs are best indicated in the posterior area where the follow-up studies found a lower failure rate. This 2D finite element study compared the stress distribution on 3-unit all-ceramic and metal-ceramic FPDs and identified the areas of major risk of failure. Three FPD models were designed: (1 metal-ceramic FPD; (2 All-ceramic FPD with the veneering porcelain on the occlusal and cervical surface of the abutment tooth; (3 All-ceramic FPD with the veneering porcelain only on the occlusal surface. A 100 N load was applied in an area of 0.5 mm² on the working cusps, following these simulations: (1 on the abutment teeth and the pontic; (2 only on the abutment teeth; and (3 only on the pontic. Relative to the maximum stress values found for the physiological load, all-ceramic FPD with only occlusal veneering porcelain produced the lowest stress value (220 MPa, followed by all-ceramic FPD with cervical veneering porcelain (322 MPa and metal-ceramic FPD (387 MPa. The stress distribution of the load applied on the abutments was significantly better compared to the other two load simulations. The highest principal stress values were low and limited in a small area for the three types of models under this load. When the load was applied on the pontic, the highest stress values appeared on the connector areas between the abutments and pontic. In conclusion, the best stress values and distribution were found for the all-ceramic FPD with the veneering porcelain only on the occlusal surface. However, in under clinical conditions, fatigue conditions and restoration defects must be considered.

  8. Effect of Taper on Stress Distribution of All Ceramic Fixed Partial Dentures: a 3D-FEA Study

    Directory of Open Access Journals (Sweden)

    F. Gerami-Panah

    2005-09-01

    Full Text Available Statement of Problem: Mechanical failure of ceramic materials is controlled by brittle fracture, mostly occurred in tension. In 3-unit all-ceramic FPDs the connector area is considered to be at fracture risk because of tensile stress concentrations.Purpose: The aim of this FE analysis was to evaluate the effect of taper on stress distribution in all-ceramic FPDs.Materials and Methods: In this experimental study two 3-D finite element models of thee-unit IPS-Empress 2 FPDs replacing mandible second premolar were created by means of finite element software. The digital images were obtained from CT scan of human skull. Abutment was reduced with 12 and 22 degrees of taper. The cement layer,PDL, cancellous bone and cortical bone were also modeled. Frameworks of core material were fabricated. A static load of 100 N was applied at mid pontic area.Resolved stresses were calculated according to the Von Mises criterion and principal stresses.Results: In both models stresses were concentrated at the connectors. The maximum stresses were lower in the model with larger taper. The maximum Von Mises stress was recorded at the connector region of the premolar and the pontic. In model with larger taper the patterns of stresses were also more distributed and less concentrated.Conclusion: The highest Von Mises and principal stress were recorded at the connectors. Tensile stresses developed at the gingival connector of premolar and pontic was higher than molar. The stress level in model with 22-degree taper was lower compare to 12-degree and the stress pattern was more distributed, lowered the risk ofconcentrations.

  9. 加氢精制装置换热器管板裂纹分析及改型设计%The Analysis of Tubesheet Cracks and Update Design of Reactor Effluent-Hydrogen Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    周玲; 马金华; 胡明东; 曾文海; 杨晓冬

    2001-01-01

    In this paper the analysis for U-tubesheet cracking in gasket groove surface by means of 2-dimmentional finite of ANSYS software was given.The stress check result of structure showed the update-design is reasonable.

  10. The reproducibility and accuracy of internal fit of Cerec 3D CAD/CAM all ceramic crowns.

    LENUS (Irish Health Repository)

    D'Arcy, Brian L

    2009-06-01

    The objective of this study was to evaluate the reproducibility and accuracy of internal fit using Cerec 3D CAD\\/CAM (computer aided design\\/computer aided manufacturing) all-ceramic crowns and to investigate the proximal contact point areas between the crowns and neighbouring teeth, in terms of location and the presence or absence of contact. A total of 48 crowns were milled and divided into two groups of twenty-four each. One group consisted of testing a Control die and the other group consisted of testing single Replica stone die duplicates of the Control die. The Internal Marginal Gap, Axio-Occlusal Transition Gap and Occlusal Gap were measured on each crown in both groups. No significant differences were identified between the mean thickness of the Marginal Gap, the Axio-Occlusal Transition Gap and the Occlusal Gap of the Control die when compared with the Replica dies indicating uniformity and consistency of the accuracy of fit and therefore die replication.

  11. Adhesive luting of all-ceramic restorations--the impact of cementation variables and short-term water storage on the strength of a feldspathic dental ceramic.

    LENUS (Irish Health Repository)

    Addison, Owen

    2008-08-01

    To investigate the impact of resin cement luting variables and short-term water storage on the strength of an adhesively luted all-ceramic restorative material. An understanding of the strengthening mechanisms will result in optimisation of operative techniques and materials selection criteria.

  12. Review and prospect of digital all-ceramic restorations%数码全瓷修复技术的现状及展望

    Institute of Scientific and Technical Information of China (English)

    万乾炳

    2011-01-01

    In recent twenty years, the physical and mechanical properties and the operation process of dental ceramic materials have gotten a huge development. All-ceramic restorations have good esthetics and biocompati-bility, so they are replacing porcelain fused metal restoration gradually. Technology of digital all-ceramic restorations use computer aided design and computer aided manufacture (CAD/CAM) to manufacture all-ceramic restorations. At present, a lot of all-ceramic restorations are completed by digital technology which is a hot spot in recent researches and clinical applications. This article will summary and prospect of digital all-ceramic restorations by necessity of digital all-ceramic restorations, CAD/CAM, design and manufacture of restoration, material selection, all-ceramic bonding techniques.%近二十多年口腔瓷材料的物理机械性能和操作工艺得到了巨大的发展,全瓷修复技术因具有良好的美观效果和生物相容性,正在逐渐取代金瓷修复技术.数码全瓷修复技术是指采用计算机辅助设计和计算机辅助制造(CAD/CAM)技术制作完成全瓷修复体的技术,目前大量的全瓷修复体都是采用数码技术完成的,是近年来研究和临床应用的热点.本文将从数码全瓷技术的必要性、CAD/CAM技术、牙体预备与修复体的设计和制作、材料选择、全瓷粘接技术等方面讨论数码全瓷修复技术的现状和发展.

  13. OPTIMAL PREPARATION JUNCTIONS FOR ALL-CERAMIC FIXED RESTORATIONS MADE BY CAM 5 – S 2 IMPRESSION, VHF

    Directory of Open Access Journals (Sweden)

    Angelina Vlahova

    2015-12-01

    Full Text Available Introduction: The type of the preparation junction is determined by a number of factors that need to be taken in consideration with CAD/CAM Fixed Prosthodontics: the material of which the construction will be made; the type and condition of the retainer teeth, of their periodontium and the occlusion; the design software, the CAM setting and the type of drills; the working protocol; the type of the cement and the method of cementation.Purpose: The aim of this publication is to describe the optimal preparation junctions for all-ceramic crown and bridge restorations made by CAM 5 - S 2 Impression, VHF.Materials and methods: Suitable are chamfer and shoulder preparation junction with rounded inner angle (width 1 - 1, 5 mm. Trimming of 1.5 – 2 mm dental tissues is necessary on the occlusal surface. The homothetic reduction of teeth is optimal.Results and discussion: The width depends on the size and vitality of the tooth. In stained teeth and those built with metal pins the removal of more tissues provides a greater volume needed to disguise the dark color. Vestibular preparation under the level of the gingiva is preferable to ensure optimal aesthetics. Preparation junction is determined also by the CAD/CAM technology - the type of drills and protocol of impression taking (classical or digital. The creation of a working model with TRIOS, 3Shape intraoral scanner is greatly facilitated by preparation junctions made above the gingival margin.Conclusion: Knowledge about the criteria for selection the preparation junctions is essential for fabrication accurate and aesthetic CAD/CAM restorations.

  14. Influence of all-ceramic and porcelain-fused-to-metal restorations on peri-implant gingival discoloration:a spectrophotometric comparison

    DEFF Research Database (Denmark)

    Peng, Min; Fei, Wei; Hosseini, Mandana;

    2013-01-01

    PURPOSE: To compare the gingival discoloration of implant supported all-ceramic and Porcelain-Fused-to-Metal (PFM) restorations in anterior maxillary region by spectrophotometric evaluation. METHODS: Eighteen patients with 29 implant-supported single crowns (11 all-ceramic restorations, 9 PFM...... restorations with titanium abutment and 9 PFM restorations with gold alloy abutment) in anterior maxillary area were recruited. The color difference between peri-implant gingival and contra-lateral/neighboring tooth mucosa were assessed using a spectrophotometer in CIELab coordinates. Subjective gingival...... restorations with titanium abutment (3.5+2.5) as regard to spectrophotometric evaluation of gingival discoloration, and no significant difference was found between the PFM restorations with titanium abutment and PFM restorations with gold alloy abutment (6.3+3.8) either. There was, however, significant...

  15. Mechanical Properties of a new Dental all-ceramic Material-zirconia Toughened Nanometer-ceramic Composite

    Institute of Scientific and Technical Information of China (English)

    CHAI Feng; XU Ling; CHAO Yong-lie; LIAO Yun-mao; ZHAO Yi-min

    2003-01-01

    Objectives:All-ceramic dental restorations are attractive to the dental community because of their advantages.But they're also challenged by relatively low flexural strength and intrinsic poor resistance to fracture.This paper aims to investigate mechanical properties of a new dental all-ceramic material, i.e. zirconia toughened nanometer-ceramic composite (α-Al2O3/nZrO2).Methods:α-Al2O3/nZrO2 ceramics powder (W) was processed with combined methods of chemical co-precipitation method and ball milling. Scanning electron microscopy (SEM)was used to determine the particle size distribution and to characterize the particle morphology of the powders. Four kinds of powders with different ZrO2 content (5wt%, 10wt%, 15wt% and 20wt%) were prepared by using α-Al2O3 powder to dilute the higher ZrO2 content powder (W). The ceramic matrix compacts were made by slip-casting technique and sintering to 1 200~1 600 ℃. The flexural strength and the fracture toughness of the matrix materials were measured via three-point bending test and single-edge notch beam methods, respectively.Results:1) The particle distribution of the Al2O3/nZrO2 powder ranged from 0.02~3.0 μm, with the superfine particles almost accounting for 20%;2) There is a significant difference of flexural strength (P<0.05) between the groups with 1 450 ℃ and 1 600 ℃ sintering temperature and 1 200 ℃;3) There is a significant difference of flexural strength (P<0.05) between different zirconia volume fraction groups with the same sintering temperature, the ceramic matrix samples with higher nZrO2 (W) content had much better mechanical properties than those of pure α-Al2O3 ceramics.Conclusions:The studied nanometer α-Al2O3/nZrO2 powder was homogeously distributed within the matrix and had reasonable powder-size gradation to improve mechanical properties of ceramics.%目的:口腔全瓷修复体以其独特优越性受到医患青睐,但脆性问题一直限制其应用范围及使用可靠性.本研

  16. The effect of ceramic thickness and number of firings on the color of a zirconium oxide based all ceramic system fabricated using CAD/CAM technology

    OpenAIRE

    Bachhav, Vinay Chila; Aras, Meena Ajay

    2011-01-01

    PURPOSE Ceramics have a long history in fixed prosthodontics for achieving optimal esthetics and various materials have been used to improve ceramic core strength. However, there is a lack of information on how color is affected by fabrication procedure. The purpose of this study was to evaluate the effects of various dentin ceramic thicknesses and repeated firings on the color of zirconium oxide all-ceramic system (Lava™) fabricated using CAD/CAM technology. MATERIALS AND METHODS Thirty disc...

  17. Tube to Tubesheet Welding of 1000 MW Nuclear Power Steam Generator%1000 MW 核电蒸汽发生器管子管板焊接

    Institute of Scientific and Technical Information of China (English)

    孙志远; 张茂龙; 胡欢

    2016-01-01

    Tube to tubesheet welding is the key sequence during fabrication of primary loop main equip-ment steam generator,quality of tube to tubesheet welding directly affect the service time of the steam gen-erator and fabricating schedules.Development of tube to tubesheet welding procedure of 1000 MW steam generator was described,the problems arising during welding were analysed,especially root discontinuity. Welding parameters were re-optimised,meanwhile welding procedure control was emphasized,then weld joints which have stable quality and good shape that conform to design requirement were obtained.%管子管板焊接是核电站一回路主设备蒸汽发生器制造过程中的关键工序,管子管板焊接质量直接影响着蒸汽发生器的使用寿命和制造进度。分别对二代改进型压水堆和三代压水堆1000 MW 蒸汽发生器管子管板焊接工艺进行介绍,比较了 RCC -M规范和 ASME 规范对管子管板焊接要求的异同,针对焊接过程中出现的问题,分析了缺陷产生的根本原因,对焊接参数重新进行优化,同时加强了焊接过程控制,得到了质量稳定、焊缝形状和尺寸均满足设计要求的焊接接头。

  18. An interdisciplinary approach to reconstruct a fractured tooth under an intact all ceramic crown: Case report with four years follow up

    Directory of Open Access Journals (Sweden)

    Sudhir Bhandari

    2011-01-01

    Full Text Available Trauma causing the fracture of a restored tooth with the extracoronal full coverage prosthesis remaining intact is a common occurrence in dental practice. Reconstruction of the damaged tooth foundation and recementation of the crown can pose quite a challenge for the restorative dentist. This case report describes an innovative interdisciplinary chairside technique for the recementation of an all-ceramic crown on a fractured maxillary central incisor. The course of care described is effective, affordable, and saves time in comparison with other treatment options for such clinical situations.

  19. The Evolution and Fabrication of Implant-supported Full-arch Hybrid Prostheses. From Conventional Casted Metal to an All-Ceramic Zirconia.

    Science.gov (United States)

    Ouzer, Amanda

    2015-11-01

    Implant-supported, full-arch hybrid prostheses have developed from cast-metal frameworks with acrylic or porcelain to all-ceramic zirconia frameworks. CAD/CAM manufacturing removed the inaccuracies seen with casting and made use of zirconia possible. The materials and processes for prosthodontic fabrication are explained. Zirconia is highly opaque and versatile. However, porcelain-veneered zirconia frameworks have shown higher enamel wear, among other problems. Lithium disilicate has been shown to be more translucent than zirconia. Improved stained and more translucent zirconia frameworks have been produced as well. These promising new methods have gained popularity, but long-term studies are scarce and, thus, more research is required.

  20. The effect of ceramic thickness and number of firings on the color of a zirconium oxide based all ceramic system fabricated using CAD/CAM technology

    Science.gov (United States)

    Aras, Meena Ajay

    2011-01-01

    PURPOSE Ceramics have a long history in fixed prosthodontics for achieving optimal esthetics and various materials have been used to improve ceramic core strength. However, there is a lack of information on how color is affected by fabrication procedure. The purpose of this study was to evaluate the effects of various dentin ceramic thicknesses and repeated firings on the color of zirconium oxide all-ceramic system (Lava™) fabricated using CAD/CAM technology. MATERIALS AND METHODS Thirty disc-shaped cores, 12 mm in diameter with a 1 mm thickness were fabricated from zirconium oxide based all ceramic systems (Lava™, 3M ESPE, St Paul, MN, USA) and divided into three groups (n = 10) according to veneering with dentin ceramic thicknesses: as 0.5, 1, or 1.5 mm. Repeated firings (3, 5, 7, or 9) were performed, and the color of the specimens was compared with the color after the initial firing. Color differences among ceramic specimens were measured using a spectrophotometer (VITA Easyshade, VITA Zahnfabrik, Bad Säckingen, Germany) and data were expressed in CIELAB system coordinates. A repeated measures ANOVA and Bonferroni post hoc test were used to analyze the data (n = 10, α=.05). RESULTS L*a*b* values of the ceramic systems were affected by the number of firings (3, 5, 7, or 9 firings) (P<.001) and ceramic thickness (0.5, 1, or 1.5 mm) (P<.001). Significant interactions were present in L*a*b* values between the number of firings and ceramic thickness (P<.001). An increase in number of firings resulted in significant increase in L* values for both 0.5 mm and 1.5 mm thicknesses (P<.01, P=.013); however it decreased for 1 mm thickness (P<.01). The a* values increased for 1 mm and 1.5 mm thicknesses (P<.01), while it decreased for 0.5 mm specimens. The b* values increased significantly for all thicknesses (P<.01, P=.022). As the dentin ceramic thickness increased, significant reductions in L* values (P<.01) were recorded. There were significant increases in both a

  1. CAD/CAM ZIRCONIA VS. SLIP-CAST GLASS-INFILTRATED ALUMINA/ZIRCONIA ALL-CERAMIC CROWNS: 2-YEAR RESULTS OF A RANDOMIZED CONTROLLED CLINICAL TRIAL

    OpenAIRE

    Murat Cavit Çehreli; Ali Murat Kökat; Kivanç Akça

    2009-01-01

    The aim of this randomized controlled clinical trial was to compare the early clinical outcome of slip-cast glass-infiltrated Alumina/Zirconia and CAD/CAM Zirconia all-ceramic crowns. A total of 30 InCeram® Zirconia and Cercon® Zirconia crowns were fabricated and cemented with a glass ionomer cement in 20 patients. At baseline, 6-month, 1-year, and 2-year recall appointments, Californian Dental Association (CDA) quality evaluation system was used to evaluate the prosthetic replacements, and p...

  2. Design and Fabrication of Heat Exchangers with Double Tubesheets%双管板换热器设计及制造

    Institute of Scientific and Technical Information of China (English)

    涂俊宏; 于东兴

    2001-01-01

    The purpose of this article is to introduce the material selection of the tubesheet, the strength calculation method, method of structure design and tube expanded fit, and the process assessment of expanding tube. What stated in this article can referenced by the engineers.%本文就管板的选材,强度计算、结构设计及胀管方法、胀接的工艺评定等问题作了介绍。仅供设计人员参考。

  3. All-Ceramic Single Crown Restauration of Zirconia Oral Implants and Its Influence on Fracture Resistance: An Investigation in the Artificial Mouth

    Directory of Open Access Journals (Sweden)

    Ralf-Joachim Kohal

    2015-04-01

    Full Text Available The aim of the current investigation was to evaluate the fracture resistance of one-piece zirconia oral implants with and without all-ceramic incisor crowns after long-term thermomechanical cycling. A total of 48 implants were evaluated. The groups with crowns (C, 24 samples and without crowns (N, 24 samples were subdivided according to the loading protocol, resulting in three groups of 8 samples each: Group “0” was not exposed to cyclic loading, whereas groups “5” and “10” were loaded with 5 and 10 million chewing cycles, respectively. This resulted in 6 different groups: C0/N0, C5/N5 and C10/N10. Subsequently, all 48 implants were statically loaded to fracture and bending moments were calculated. All implants survived the artificial aging. For the static loading the following average bending moments were calculated: C0: 326 Ncm; C5: 339 Ncm; C10: 369 Ncm; N0: 339 Ncm; N5: 398 Ncm and N10: 355 Ncm. To a certain extent, thermomechanical cycling resulted in an increase of fracture resistance which did not prove to be statistically significant. Regarding its fracture resistance, the evaluated ceramic implant system made of Y-TZP seems to be able to resist physiological chewing forces long-term. Restauration with all-ceramic single crowns showed no negative influence on fracture resistance.

  4. 扭曲管换热器管板的有限元分析%Finite Element Analysis of the Tubesheet of Twisted Tube Heat Exchangers

    Institute of Scientific and Technical Information of China (English)

    杨旭; 钱才富

    2014-01-01

    采用有限元分析软件ANSYS,对扭曲管换热器的管板在三种工况下的应力进行计算,分析了扭曲管轴向刚度削弱系数对管板应力强度及扭曲管轴向应力的影响。结果表明,扭曲管的轴向变形补偿能力优于普通直管,可以降低在温差载荷作用下管板中的应力,但会提高压力作用下的管板应力。在压力载荷作用下,扭曲管上的平均应力大小与普通直管差别不大,但扭曲管的轴向应力在管子横截面上的分布不均匀,局部的轴向应力远远高于平均应力水平,因此扭曲管抗疲劳和应力腐蚀开裂的能力不如直管。不同厚度的管板受扭曲管管束轴向刚度的影响不同,当管板厚度较小时,扭曲管管束轴向刚度的影响较大。%Finite element analysis with the software ANSYS was performed on the tubesheet of a twisted tube heat exchanger under three loading cases.Effects of the axial stiffness of the twisted tubes on the strength of the tubesheet were investigated.It is found that as the axial deformation compensation of the twisted tubes is better than that of the plain straight tube,stresses at the tubesheet are decreased when using twisted tubes under the thermal loading,but the stresses are increased under the pressure loadings. Although the average axial stress at the twisted tubes is almost the same as that at the straight tubes,the stress distribution at the cross section of the twisted tubes is not uniform and the maximum stress is much larger than the average stress,which implies that ability of the twisted tubes to resist fatigue or stress cor-rosion cracking is much weaker than the straight tubes.For different thickness of the tubesheet,the effect of the axial stiffness of the twisted tubes is different.The smaller the thickness of the tubesheet,the stron-ger the effect is.

  5. Selection and application of oral all-ceramic crown materials%口腔全瓷冠修复材料的选择及应用

    Institute of Scientific and Technical Information of China (English)

    程谨春

    2011-01-01

    BACKGROUND: Compared with porcelain fused to metal crown, the all-ceramic crown materials have been more and more applied in clinical anterior teeth restoration due to natural and stable color, low thermal conductivity, non-electric conductivity, wear resistance, good biocompatibility, non-transparent metallic, and relatively simple operations.OBJECTIVE: To summarize the characteristics, production methods and clinical application of different all-ceramic crown materials.METHODS: A computer-based online retrieval was performed in Wanfang database and Medline database between 2001 and 2011 for articles regarding the characteristics, production methods, physical and mechanical strength, chemical and biological compatibility, aesthetic appearance and clinical application of different all-ceramic crown materials.RESULTS AND CONCLUSION: Currently, the clinically used all-ceramic materials can be divided into slip casting porcelain,casting ceramic, heat-pressed glass ceramic, glass-infiltrated ceramics, densely-sintered aluminum oxide polycrystalline, partially stabilized tetragonal zirconium oxide polycrystalline, and nano-composite ceramic. Different materials have its specific mechanical properties and clinical indications, so clinical selection must be based on specific conditions. With the advance of high-strength ceramic studies, all-ceramic restorations become widely applied, and high-aluminum ceramic represented by In-ceram and zirconia all-ceramic crowns can achieve good effects within a short and long term, foreign clinical experiments have conducted the enlargement from anterior crown to rear crown and bridge. To insure optimum long-term clinical results of all-ceramic crown restorations, the key is to overcome the fragmentation of dental prosthesis, mainly through modifying the composition, improving the anti -smash property of ceramic materials, and a series of prevention measures.%背景:相对于金属烤瓷冠而言,全瓷冠具有色泽稳定自然,导

  6. 全瓷冠与金属烤瓷冠的临床应用分析%Clinical application on all ceramic crowns and metal ceramic crowns

    Institute of Scientific and Technical Information of China (English)

    代伟; 刘阳

    2015-01-01

    Objective:To investigate the aesthetic effect and the change of periodontal tissue in the restoration of all ceramic crowns and metal ceramic crowns.Methods:108 cases of dental restoration restoration on a total of 168 teeth were selected,they were divided into two groups,with 84 teeth in each group,patients in the observation group were treated with zirconia all ceramic dental restoration,while in the control with Ni Cr alloy porcelain dental restoration.Results:After 1 years,the observation group did not appear cervical margin black line,while 39 teeth in the control group had appear black or marginal discoloration problem. Conclusion:Compared with metal ceramic crowns,all ceramic crowns can reduce the damage to the periodontal tissues,and the appearance and color are excellent,with higher simulation,however,in the crown and bridge it is not as good as the metal porcelain teeth.%目的:探讨全瓷冠与金属烤瓷冠修复的美学效果及牙周组织变化.方法:收治牙齿修复患者 108 例,共计168颗牙,随机分为两组,各84颗,观察组进行二氧化锆全瓷牙修复,对照组进行镍铬合金烤瓷牙修复.结果:1年后,观察组未出现颈缘黑线情况,对照组有39颗出现颈缘发黑、变色问题.结论:全瓷冠相较于金属烤瓷冠用于牙体修复可减少对牙周组织的损伤,而且外观与色泽较为优良,有更高的仿真性,然而在冠桥折断方面不如金属烤瓷牙.

  7. Investigation of shade selection on all-ceramic restorations of anterior teeth%全瓷修复体前牙比色现况调查

    Institute of Scientific and Technical Information of China (English)

    刘莹莹; 王芳; 钟晓霞; 邓华颉

    2013-01-01

    Objective: The aim of the survey was to obtain the basic information of shade selection on all-ceramic restorations of the anterior teeth so as to enhance doctor's understanding of color matching and improve their quality of shade selection. Method:474 pieces of anterior teeth working authorizations of all-ceramic restorations were divided into three groups according to the level of consignor. The questionnaire included tooth position, patient age, gender, including doctor partition colorimetric, whether digital photography auxiliary colorimetric or whether to record color special anatomical structure of the patient characteristics including stained, cracked, developmental ditch projects. Result: The statistical test showed there was significant difference in patient age, gender, doctor partition colorimetric and digital photography auxiliary colori- metric among these three groups. Conclusion: In this survey, the quality of shade selection on all-ceramic restorations of anterior teeth is generally ignored by dentists. Doctors for the partition colorimetric and digital photography auxiliary colorimet- ric technique needs to be future strengthened.%目的:了解全瓷修复体前牙比色情况,增强医生对全瓷牙与天然牙颜色匹配度的认识,进一步提高修复体比色质量.方法:搜集全瓷修复体前牙加工单共474份,根据医生所在单位等级将加工单分为3组,对其比色信息进行调查.调查内容包括患者牙位、年龄、性别,包括医生是否分区比色或特殊配色、是否有数码摄影辅助比色、是否记录患者特征色,特殊解剖结构,包括染色、隐裂、发育沟等项目.结果:3组调查项目的差异主要集中在年龄、性别、分区比色或特殊配色、数码摄影辅助比色方面.结论:全瓷修复体前牙的比色表达情况受到普遍忽视,医生对于全瓷材料前牙的分区比色或数码摄影辅助比色等技术有待进一步加强.

  8. The Evolution and Fabrication of Implant-supported Full-arch Hybrid Prostheses. From Conventional Casted Metal to an All-Ceramic Zirconia.

    Science.gov (United States)

    Ouzer, Amanda

    2015-11-01

    Implant-supported, full-arch hybrid prostheses have developed from cast-metal frameworks with acrylic or porcelain to all-ceramic zirconia frameworks. CAD/CAM manufacturing removed the inaccuracies seen with casting and made use of zirconia possible. The materials and processes for prosthodontic fabrication are explained. Zirconia is highly opaque and versatile. However, porcelain-veneered zirconia frameworks have shown higher enamel wear, among other problems. Lithium disilicate has been shown to be more translucent than zirconia. Improved stained and more translucent zirconia frameworks have been produced as well. These promising new methods have gained popularity, but long-term studies are scarce and, thus, more research is required. PMID:26749784

  9. CAD/CAM Zirconia vs. slip-cast glass-infiltrated Alumina/Zirconia all-ceramic crowns: 2-year results of a randomized controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Murat Cavit Çehreli

    2009-02-01

    Full Text Available The aim of this randomized controlled clinical trial was to compare the early clinical outcome of slip-cast glass-infiltrated Alumina/Zirconia and CAD/CAM Zirconia all-ceramic crowns. A total of 30 InCeram® Zirconia and Cercon® Zirconia crowns were fabricated and cemented with a glass ionomer cement in 20 patients. At baseline, 6-month, 1-year, and 2-year recall appointments, Californian Dental Association (CDA quality evaluation system was used to evaluate the prosthetic replacements, and plaque and gingival index scores were used to explore the periodontal outcome of the treatments. No clinical sign of marginal discoloration, persistent pain and secondary caries was detected in any of the restorations. All InCeram® Zirconia crowns survived during the 2-year period, although one nonvital tooth experienced root fracture coupled with the fracture of the veneering porcelain of the restoration. One Cercon® Zirconia restoration fractured and was replaced. According to the CDA criteria, marginal integrity was rated excellent for InCeram® Zirconia (73% and Cercon® Zirconia (80% restorations, respectively. Slight color mismatch rate was higher for InCeram® Zirconia restorations (66% than Cercon® Zirconia (26% restorations. Plaque and gingival index scores were mostly zero and almost constant over time. Time-dependent changes in plaque and gingival index scores within and between groups were statistically similar (p>0.05. This clinical study demonstrates that single-tooth InCeram® Zirconia and Cercon® Zirconia crowns have comparable early clinical outcome, both seem as acceptable treatment modalities, and most importantly, all-ceramic alumina crowns strengthened by 25% zirconia can sufficiently withstand functional load in the posterior zone.

  10. CAD/CAM ZIRCONIA VS. SLIP-CAST GLASS-INFILTRATED ALUMINA/ZIRCONIA ALL-CERAMIC CROWNS: 2-YEAR RESULTS OF A RANDOMIZED CONTROLLED CLINICAL TRIAL

    Science.gov (United States)

    Çehreli, Murat Cavit; Kökat, Ali Murat; Akça, Kivanç

    2009-01-01

    The aim of this randomized controlled clinical trial was to compare the early clinical outcome of slip-cast glass-infiltrated Alumina/Zirconia and CAD/CAM Zirconia all-ceramic crowns. A total of 30 InCeram® Zirconia and Cercon® Zirconia crowns were fabricated and cemented with a glass ionomer cement in 20 patients. At baseline, 6-month, 1-year, and 2-year recall appointments, Californian Dental Association (CDA) quality evaluation system was used to evaluate the prosthetic replacements, and plaque and gingival index scores were used to explore the periodontal outcome of the treatments. No clinical sign of marginal discoloration, persistent pain and secondary caries was detected in any of the restorations. All InCeram® Zirconia crowns survived during the 2-year period, although one nonvital tooth experienced root fracture coupled with the fracture of the veneering porcelain of the restoration. One Cercon® Zirconia restoration fractured and was replaced. According to the CDA criteria, marginal integrity was rated excellent for InCeram® Zirconia (73%) and Cercon® Zirconia (80%) restorations, respectively. Slight color mismatch rate was higher for InCeram® Zirconia restorations (66%) than Cercon® Zirconia (26%) restorations. Plaque and gingival index scores were mostly zero and almost constant over time. Time-dependent changes in plaque and gingival index scores within and between groups were statistically similar (p>0.05). This clinical study demonstrates that single-tooth InCeram® Zirconia and Cercon® Zirconia crowns have comparable early clinical outcome, both seem as acceptable treatment modalities, and most importantly, all-ceramic alumina crowns strengthened by 25% zirconia can sufficiently withstand functional load in the posterior zone. PMID:19148406

  11. Influence of Different Framework Designs on the Fracture Properties of Ceria-Stabilized Tetragonal Zirconia/Alumina-Based All-Ceramic Crowns

    Directory of Open Access Journals (Sweden)

    Tomofumi Sawada

    2016-05-01

    Full Text Available The aim of this study was to evaluate the fracture load and failure mode of all-ceramic crowns with different ceria-stabilized tetragonal zirconia/alumina nanocomposite (Ce-TZP/A framework designs. Four frameworks (anatomical shape: AS, with a buccal or lingual supporting structure: BS and LS, or buccal and lingual supporting structures: BLS were fabricated. All frameworks were veneered with porcelain to fabricate all-ceramic crowns followed by cementation to tooth analogs. The fracture load of each crown either without or with pre-loading (1.2 million cycles, 49 N was measured. The failure mode was classified into partial or complete fracture. Differences were tested for significance (p < 0.05 by a two-way Analysis of Variance (ANOVA, followed by Tukey’s test and by Fisher’s exact test, respectively. Without pre-loading, supporting structures did not influence the fracture load or failure mode. Partial fractures were the most common failure mode. Pre-loading promoted the severity of the failure mode, although the fracture load among the framework designs was not influenced. In the AS group, prefailures were observed during pre-loading, and complete fractures were significantly increased after pre-loading. In contrast, the failure mode of the BLS group remained unchanged, showing only partial fracture even after pre-loading. This Ce-TZP/A framework design, comprised of an anatomical shape with additional buccal and lingual structures, has the potential to reduce the chipping of the veneering porcelain.

  12. 前牙全瓷冠饰瓷崩裂断口形貌分析%Fractographic analysis of clinically failed anterior all ceramic crowns

    Institute of Scientific and Technical Information of China (English)

    杜倩; 周敏波; 张新平; 赵克

    2012-01-01

    Objective To identify the site of crack initiation and propagation path of clinically failed all ceramic crowns by fractographic analysis.Methods Three clinically failed anterior IPS Empress Ⅱ crowns and two anterior In-Ceram alumina crowns were retrieved.Fracture surfaces were examined using both optical stereo and scanning electron microscopy.Fractographic theory and fracture mechanics principles were applied to disclose the damage characteristics and fracture mode.Results All the crowns failed by cohesive failure within the veneer on the labial surface.Critical crack originated at the incisal contact area and propagated gingivally. Porosity was found withiu the veneer because of slurry preparation and the sintering of veneer powder.Conclusions Cohesive failure within the veneer is the main failure mode of all ceramic crown.Veneer becomes vulnerable when flaws are present. To reduce the chances of chipping,multi-point occlusal contacts are recommended,and layering and sintering technique of veneering layer should also be improved.%目的 通过断口形貌观察分析临床失效的前牙全瓷冠,分析疲劳损伤的起源和发展,以期为优化全瓷冠桥修复体的临床设计及修复工艺提供依据.方法 收集临床失效前牙二硅酸锂基瓷冠( IPS EmpressⅡ)3例,玻璃渗透氧化铝瓷冠(In-Ceram)2例,采用体视显微镜和扫描电子显微镜观察断裂面,分析特征形貌.结果 5例全瓷冠主要失效模式均为唇侧饰瓷内聚破坏,裂纹起源于切端咬合接触区,并由切端向龈端扩展,裂纹源附近饰瓷内部见较多气孔缺陷.结论 饰瓷内聚破坏是全瓷修复失效的重要原因;饰瓷内部易出现制作缺陷,成为双层瓷修复体的薄弱环节;改良饰瓷制作及烧结工艺,设计多点咬合接触将有助于减少饰瓷崩瓷.

  13. The differentiation of materials and methods of all-ceramic restorations%全瓷修复材料和方法的分化

    Institute of Scientific and Technical Information of China (English)

    刘峰

    2011-01-01

    全瓷修复材料包括玻璃基质陶瓷、玻璃渗透氧化物陶瓷、致密氧化铝陶瓷和氧化锆陶瓷4类,全瓷修复方法包括全冠、贴面、瓷粘接修复等。不同的材料和方法搭配,获得的治疗效果差异明显。确定最适宜的搭配形式,可以明显降低临床选择治疗方案的难度。对于活髓牙修复,最佳治疗方案是采用玻璃基质陶瓷材料,进行瓷贴面或瓷粘接修复;死髓前牙一般不采用玻璃基质陶瓷全冠修复,大部分可采用的治疗方案是氧化锆陶瓷全冠修复,如果基牙变色严重可选择玻璃渗透氧化物陶瓷全冠修复;死髓后牙修复常规采用氧化锆陶瓷材料全冠修复,通过增加轴沟或钉洞辅助固位设计提高固位力,通过采用高颈环设计或者全锆冠设计提高修复体的强度。%All-ceramic materials include glass-ceramics, glass-infiltrated ceramics, pure alumina core system and zirconia core system; and all-ceramic restoration methods include crown, veneer and ceramic-bonding restorations. Different match of materials and methods will lead to different treatment result. The most suitable match can help dentists lower the risk. For most vital teeth, the most suitable design is veneers or bonded-ceramic restorations; but for unvital anterior teeth, glass-ceramic is not suitable, and in most cases zirconia crown is the best choice, or in serious strained teeth glass-infiltrated ceramic could be used; in vital posterior teeth, zirconia crown is the most suitable treatment plan, whose retention force can be increased by assistant retention form like axis grooves or pin hole, and strength can be enhanced by high cervical rings or full-zirconia design.

  14. Introduction to Heat Medium Heat Exchanger Constructed with Double Tube and Double Tubesheet (Safe Heat Exchanger)%双管双管板热媒热交换器(安全热交换器)

    Institute of Scientific and Technical Information of China (English)

    朱敏

    2012-01-01

    双管双管板热媒热交换器是近代在双管板基础上发展起来的一种新型管壳式热交换器,也称安全热交换器,适用于管、壳程介质严禁掺混的场合.结合双管板热交换器,对双管双管板热媒热交换器的有关要点做了简要介绍,可为此类热交换器的设计、制造及使用者提供一定的参考.%Heat medium heat exchanger constructed with double tube and double tube-sheet is a new type of tubular heat exchanger developed on the basis of double tube-sheet type in recently times, it is also called safe heat exchanger. This kind of heat exchanger is able to be applied to such occasions where the fluid is strictly prohibited to blend and mix between tube side and shell side. Based on double tube-sheet heat exchanger, some key points of designing and manufacturing for heat medium heat exchanger are introduced, so it can be a reference for designer, manufacturer and uses for this kind of heat exchanger.

  15. Effect of abutment shade, ceramic thickness, and coping type on the final shade of zirconia all-ceramic restorations: in vitro study of color masking ability

    Science.gov (United States)

    Oh, Seon-Hee

    2015-01-01

    PURPOSE The aim of the study was to evaluate the effect of abutment shade, ceramic thickness, and coping type on the final shade of zirconia all-ceramic restorations. MATERIALS AND METHODS Three different types of disk-shaped zirconia coping specimens (Lava, Cercon, Zirkonzahn: ø10 mm × 0.4 mm) were fabricated and veneered with IPS e.max Press Ceram (shade A2), for total thicknesses of 1 and 1.5 mm. A total of sixty zirconia restoration specimens were divided into six groups based on their coping types and thicknesses. The abutment specimens (ø10 mm × 7 mm) were prepared with gold alloy, base metal (nickel-chromium) alloy, and four different shades (A1, A2, A3, A4) of composite resins. The average L*, a*, b* values of the zirconia specimens on the six abutment specimens were measured with a dental colorimeter, and the statistical significance in the effects of three variables was analyzed by using repeated measures analysis of variance (α=.05).The average shade difference (ΔE) values of the zirconia specimens between the A2 composite resin abutment and other abutments were also evaluated. RESULTS The effects of zirconia specimen thickness (P<.001), abutment shade (P<.001), and type of zirconia copings (P<.003) on the final shade of the zirconia restorations were significant. The average ΔE value of Lava specimens (1 mm) between the A2 composite resin and gold alloy abutments was higher (close to the acceptability threshold of 5.5 ΔE) than th ose between the A2 composite resin and other abutments. CONCLUSION This in-vitro study demonstrated that abutment shade, ceramic thickness, and coping type affected the resulting shade of zirconia restorations. PMID:26576252

  16. In Vitro Effect of Porcelain Firing Cycle and Different Thicknesses of IPS E.max CAD Core on Marginal Accuracy of All-Ceramic Restorations

    Science.gov (United States)

    Jalalian, Ezatollah; Zarbakhsh, Arash; Mohtashamrad, Zahra; Nourbakhsh, Nazanin; Jafarpour, Esmat

    2015-01-01

    Objectives: Marginal adaptation is important for long-term success of full-coverage restorations. The aim of this study was to determine the effect of porcelain firing cycle and different thicknesses of IPS e.max core on marginal accuracy of all-ceramic restorations. Materials and Methods: A standard stainless steel die with 0.8 mm classic chamfer finish line and 10° taper was used in this in vitro study. An impression was taken from the stainless steel die to fabricate 20 epoxy resin dies, which were then scanned and IPS e.max CAD cores were fabricated using computer-aided design/computer-aided manufacturing (CAD/CAM) technique in two groups of 10 with 0.7 mm (group A) and 0.4mm (group B) core thickness. Copings were then placed on their respective dies and randomly numbered. The amount of marginal gap was measured in 10 points under a stereomicroscope (×90 magnification) before and after porcelain veneering. Results: The mean gap in 0.7mm and 0.4mm core thicknesses was 15.62±2.55μm and 19.68±3.09μm before porcelain firing and 32.01±3.19μm and 35.24±3.8μm after porcelain firing. The difference in marginal gap between the two thicknesses was significant before porcelain firing but not significant after veneering. Significant differences were also found in the marginal gap before and after porcelain veneering in each group. Conclusion: The porcelain firing cycle increases marginal gap in IPS e.max CAD restorations; 0.3 mm decrease in core thickness slightly increased marginal discrepancy, however it was not significant. PMID:27507992

  17. Rotational accuracy of all-ceramic restorations on ceraone components = Liberdade rotacional de restaurações totalmente cerâmicas sobre componentes ceraone

    Directory of Open Access Journals (Sweden)

    Webster, Jacqueline

    2005-01-01

    Full Text Available Objetivo: Este estudo avaliou a desadaptação interna de sistemas cerâmicos em prótese sobre implantes em relação à liberdade rotacional das restaurações após várias cocções da porcelana. Materiais e métodos: Foram analisados três sistemas cerâmicos: Procera AllCeram, In-Ceram e CeraOne sobre análogo e intermediário CeraOne. A liberdade rotacional foi medida com um dispositivo acoplado a um relógio comparador em quatro tempos: fase de coifa, após aplicação do corpo da porcelana e glaze, e após duas queimas adicionais. Os dados foram analisados por testes de Friedman, de Kruskal-Wallis e de Wilcoxon, α = 0,01. Resultados: As médias de liberdade rotacional em graus foram: 0,08 para In-Ceram/Análogo; 1,64 para Procera/ Intermediário; 1,72 para CeraOne/Intermediário; 1,88 para CeraOne/Análogo e 1,97 para Procera/Análogo. O sistema In-Ceram sobre o análogo apresentou níveis de liberdade rotacional dez a vinte vezes menores que CeraOne e Procera. Não houve diferença entre as fases de confecção da restauração para In-Ceram. O comportamento de CeraOne e Procera foi similar, com aumento da liberdade rotacional sobre intermediário e análogo com a progressão da confecção da restauração. A liberdade rotacional sobre intermediário foi menor que sobre análogo. Conclusão: A liberdade rotacional variou em função da etapa do processo de fabricação dependendo do sistema totalmente cerâmico

  18. Fabrication of all-ceramic dental restorations with CEREC 3D CAD/CAM system%CEREC 3D系统制作全瓷修复体的临床研究

    Institute of Scientific and Technical Information of China (English)

    赵堂民; 王莹; 夏璐; 关丽娜; 刘戈边

    2013-01-01

    Objective:To observe clinical effect of all - ceramic dental restorations fabricated by CEREC 3D CAD/CAM system. Methods: Forty - one patients with 67 all - ceramic restorations were involved in this study. After one year, the clinical performance of the restoration was evaluated by the same dentist using modified USPHS criteria. Results; 86. 57% of all -ceramic restorations scored grade A by the modified USPHS criteria. The color matching of the restoration was satisfactory in 97. 01% patients with grade A by the criteria. Conclusion: The CEREC 3D CAD/CAM system could offer easy, accurate and quick fabrication of all -ceramic dental restorations with natural color.%目的:观察椅旁CAD/CAM系统CEREC 3D制作的各类全瓷修复体的临床应用效果.方法:选取41名患者,按照CAD/CAM系统CEREC 3D标准程序制作完成各类全瓷修复体67个.修复后追踪观察1年,由同一位医师按照改良的USPHS标准对修复体进行评价.结果:86.57%的全瓷修复体各项检查标准都达到了改良的USPHS标准的A类,颜色匹配方面最令人满意,达到A类标准者为97.01%.结论:CEREC 3D CAD/CAM系统能够便捷、精准、高效地制作具有天然牙色的全瓷修复体,临床效果令人满意.

  19. Finite element analysis of residual stress in a bilayered all-ceramic crown%饰瓷与基底瓷双层结构全瓷冠残余应力的三维有限元分析

    Institute of Scientific and Technical Information of China (English)

    马新扬; 辛海涛; 侯兵; 吴张

    2011-01-01

    目的 探讨全瓷冠高温烧结后冷却过程中,冠内不同部位以及结合界面处残余应力的分布及影响因素.方法 三维光学面扫描仪对全瓷修复体基底冠与最终牙冠表面分别进行扫描,获取冠内外点云数据;Geomagic Studio8与UG NX5将扫描后的壳体模型转成三维实体模型;运用有限元分析软件ABAQUS6.7热位移偶合单元对模型进行网格划分,施加温度载荷,模拟全瓷冠高温烧结后冷却过程,分析全瓷冠残余应力分布,并以修饰瓷与基底瓷热膨胀系数相同模型进行对比.结果 建立起饰瓷与基底瓷双层结构的全瓷冠三维有限元模型.残余应力在全瓷冠颈缘处修饰-基底瓷结合界面分布最大,在修饰瓷较厚部位残余应力分布较小.随着烧结温度的降低,残余应力逐渐增大.结论 运用三维面扫描建立的双层全瓷冠三维有限元模型精确,方法简便;全瓷冠残余应力分布较高部位与临床修复体的易破坏部位一致,提示,在进行全瓷冠修复时要注意基底瓷与修饰瓷热膨胀系数的匹配并且要保证冠边缘保持足够的瓷层厚度.%Objective To investigate the residual stress distribution of a bilayered all-ceramic crown during the cooling process using the finite element method. Methods The 3D point picture of a bilayered all-ceramic crown was obtained through three dimentional sensing system (3DSS). G eomagic Studio8 and UG NX5 were employed to transform the 3D point picture of a bilayered all-ceramic crown into a 3D solid model. The residual stress of the model was analyzed. The results were compared when the coefficient values of the veneer and core were the same. Results A 3D finite element model of bilayered dental ceramic crown was established. The maximum residual stress was found at the interface between the core and veneer on the margin of all-ceramic crown. The residual stress was minimum where the veneer ceramic was thickest. The residual stress also

  20. Effects of Number of Firings on the Microstructure and Color Difference of Dental All-ceramic Systems%烧结次数对牙科全瓷微结构和色差的影响

    Institute of Scientific and Technical Information of China (English)

    庞莉苹; 姚江武

    2012-01-01

    Objective: To evaluate the effects of number of firings on the microstructure and color difference of dental all-ceramic systems. Methods: Specimens were made of three kinds of all- ceramics systems i. e. heat pressed all-ceramic (IPS Empress Ⅱ) . alumina all-ceramic (In-Cream alumina) and zirconia all -ceramic (Cer-con CAD/CAM zirconia). Specimens after firings were characterised using X-ray diffractQmer(XRD) and scanning electron microscope (SEM)and color difference (AE * ab) of all-ceramic after firings was measured and calculated by spectrophotometer. Results: XRD and SEM revealed the transformation of core and veneering material of Empress H from an amorphous glass to a crystalline phase and the change of alumina and zirconia in reverse after 5 firings. Significant interactions were present between the number of firings and the brand and △E * ab (P the change of color difference after 5 firings was still within perceptible and acceptable range.%目的:评价烧结次数对牙科全瓷微结构和色差的影响.方法:样本由3种品牌的全瓷材料制作,即:热压全瓷(IPS EmpressⅡ)、氧化铝全瓷(In-Cream alumina)和氧化锆全瓷(Cercon CAD/CAM zirconia).通过X射线衍射仪(x- ray diffractomer,XRD)和扫描电子显微镜(scanning electron microscope,SEM)表征烧结后全瓷样本,分光光谱仪上测量和计算烧结后全瓷样本的色差(△E* ab).结果:XRD和SEM结果显示5次烧结后热压全瓷基底冠和饰面瓷均发生由无定形玻璃相向晶相的转变,而氧化铝全瓷和氧化错全瓷的转变则相反.烧结次数与全瓷品牌和△E* ab之间存在交互作用(P<0.05).氧化铝全瓷5次烧结后的色差最大(1.9),已接近临床可接受色差的域值.结论:烧结次数因玻璃相与晶相之间的相互转变对色差造成影响,5次烧结后热压全瓷发生了玻璃相向晶相的转化,氧化锆全瓷几乎不受影响.但5次烧结后的3种全瓷的色差变化仍在视觉可接受范围内.

  1. Clinical research of long-term aesthetic results of the anterior region of zirconia all-ceramic crown%氧化锆全瓷冠在前牙美学修复中的临床应用研究

    Institute of Scientific and Technical Information of China (English)

    王红梅; 杨永进; 蔡兴伟; 郭军; 吕晓宁

    2012-01-01

    目的:探讨氧化锆全瓷冠在前牙美学修复中的应用效果和美学效果的稳定性及其相关影响因素.方法:应用CAD/CAM技术,对20例前牙要求美学修复的患者,共44颗前牙进行氧化锆全瓷冠修复,修复后定期随访2年,通过观察患者对全瓷冠颜色的满意程度,全瓷冠颜色的口内适应情况,颜色的改变情况及牙龈组织的健康状况等,来综合评价氧化锆全瓷冠在前牙美学修复中的应用效果.结果:氧化锆的比色效果在口内的适应性较好,自然美观;两年内患者对其美学效果的评价一致,满意程度高;两年随访观察中只有2例吸烟的男性患者发生颜色改变,其余患者颜色均未发生明显改变,牙龈健康状况良好.结论:氧化锆全瓷冠的前牙美学修复效果良好且稳定,患者满意,具有广阔的应用前景.%Objective To study the repair effect, stability of aesthetic effect and its related factors of zirconia all-ceramic crowns in the anterior dental esthetics restoration. Methods 20 patients who with requirements of anterior teeth aesthetics restoration, a total of 44 anterior teeth of zirconia all-ceramic crown restoration using the CAD/CAM tecnolory, and regular follow-up of 2 years after repair. Then compare the patients' satisfactions on all-ceramic crown color, all-ceramic crown color intraoral adaptation, color changes and the gum tissue health to evaluate the application effect of zirconia all-ceramic crowns in the anterior dental esthetics repair comprehensively. Results The colorimetric effect of zirconia is natural appearance in the mouth; all the patients show high levels of satisfaction during two years follow-up observation on the aesthetic evaluation of the effect of consistent.Only two smoking male patients with color change and the remaining patients had no obvious color change.and the gingival health is good. Conclusion The repair effect of zirconia all-ceramic crown of anterior dental esthetics is

  2. 氧化锆基台在种植体支持的全瓷修复中的应用%The application of zirconia abutment in implant supported all - ceramic restoration

    Institute of Scientific and Technical Information of China (English)

    王大山; 杨建军; 邓悦; 吴品林; 杨振; 杨凤丽; 张慧敏

    2011-01-01

    目的 探讨氧化锆基台的应用及种植体支持的全瓷修复体的临床效果.方法 选择安多键内连接种植系统φ4.0×10ram种植体植入缺牙区,上颌植入6个月、下颌植入3个月后安装自制的氧化锆基台;将基台予以磨改预留修复间隙,取印模,灌制石膏模型;应用CAD/CAM制作全瓷冠、桥;将全瓷修复体与基台粘接固位;应用MINRAY口内数字X线摄片系统和X线摄片定位仪,拍摄安装氧化锆基台时和全瓷修复体粘接后36个月时的X线片进行测量,对比分析.结果 自制的氧化锆基台能与种植体顺利装配,应用该基台和CAD/CAM制作的全瓷冠、桥修复体完成的15例患者18颗种植义齿全瓷修复的即刻效果满意,追踪30-36个月,所有患者的种植义齿使用良好,修复体和基台均无松动脱落与折裂、折断,牙周无炎症及牙槽骨吸收,部分患者的牙槽骨显示增高,患者满意度高.结论 应用氧化锆基台配合CAD/CAM氧化锆全瓷冠、桥修复体,不仅可获得满意的美学效果,还有益于种植义齿周围组织的健康.%Objective ThiS study is to discuss the application of zirconia abutment and Lhe clinical results of the implant supponed all - ceramic restoration.Methods Embed the Anthogyr inter - joins implant system ( φ 4.0 × 10mm)into the edentulous region, install the self - made zirconia abutment after 6 months maxilla implantation or 3 months mandible implantation; Then the abutment is ground to reserve restoration space and the impression is made to cast plaster mould; Make the all - ceramic crown/ bridge by CAD/CAM before adhere and fix the all - ceramic restoration with the abutment; Use MINRAY digital X - ray shooting system and X - ray holders system to shoot X - ray at the time of zirconia abutment installation and 36 months after the adhesion of the all - ceramic restoration then carry out measurement and comparative analysis.Results The self - made zirconia abutment can match well

  3. 应用BEATIFIT口内修补全瓷牙崩瓷效果分析%Analysis of the effect of BEATIFIT applicated in intraoral repair porcelain of all ceramic dental

    Institute of Scientific and Technical Information of China (English)

    刘慧丽

    2015-01-01

    目的:探讨应用BEATIFIT口内修补全瓷牙崩瓷的应用效果。方法:收治需进行牙修复患者64例,随机分为试验组和对照组,各32例,试验组给予BEATIFIT口内修补全瓷牙崩瓷法治疗,对照组给予常规治疗。结果:试验组治疗效果显著优于对照组(P<0.05)。结论:应用BEATIFIT口内修补全瓷牙崩瓷,不仅恢复了患者原有牙的外形,同时也恢复了原有牙的色泽,临床效果显著。%Objective:To explore the effect of BEATIFIT applicated in intraoral repair porcelain of all ceramic dental.Methods:64 patients who needed dental restoration were selected.They were randomly divided into the experimental group and the control group with 32 cases in each.Patients in the experimental group were given BEATIFIT repair in all ceramic dental porcelain therapy,while patients in the control group were given routine treatment.Results:The treatment effect of the experimental group was significantly better than that of the control group(P<0.05).Conclusion:Application of BEATIFIT in intraoral repair porcelain of all ceramic dental not only can restore the original appearance of dental,but also restore the original color of the teeth,so it has a significant clinical effect.

  4. 全瓷修复技术治疗职业性牙酸蚀病的研究%The research in the treatment of occupational dental erosion using all-ceramic dental restorations

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    目的:探讨用全瓷修复技术治疗职业性牙酸蚀病的临床效果。方法:2010年3月-2013年3月来我院就诊的23例职业性牙酸蚀病患者采用全瓷修复技术治疗。分别于修复后3个月、6个月、1年、3年复查。复查内容包括:修复体边缘、解剖外形、表面光滑度、颜色、患者使用满意度。结果:整个随访期间,23例职业性牙酸蚀病患者面部外形改善,咀嚼功能恢复良好,患者对修复体的美观及舒适性均较为满意。结论:用全瓷修复技术治疗职业性牙酸蚀病能恢复患者美观,提高咀嚼效率。同时还应加强口腔健康和个人防护宣教。%Objective To evaluate the clinical outcomes of therapy using all- ceramic dental restorations for patients with occupational dental erosion. Methods From March 2010 to March 2013, twenty- three patients with occupational dental erosion were treated with all- ceramic dental restorations.The edge of the restorations, anatomical shape,smoothness,color,patients'satisfaction had been observed at 3months,6months,1 year and 3 years after treatment. Results During the follow-up period,all patients with all-ceramic dental satisfied with the appearance and masticatory function. Conclusion The all-ceramic dental restorations showed good clinical effects in improving appearance and masticatory efficiency,at the same time the oral health education and personal protection should be strengthened.

  5. Study of using all ceramic restoration to correct anterior mild malocclusion in adult%全瓷修复体应用于成人前牙轻度错(牙合)畸形的临床分析

    Institute of Scientific and Technical Information of China (English)

    欧祥林; 张雅蓉; 樊弘毅; 朱卓立

    2012-01-01

    Objective Through using modern all ceramic technique, we are able to correct anterior mild malocclusion in adult, at the same time achieve a great cosmetic result in a very short course of treatment. Methods 134 patients, total of 478 anterior teeth that had mild malocclusion and discoloration were involved in the study. All patients did not accept or not suitable for lengthy orthodontic treatment. Study model impression was taken and poured, by all ceramic standard procedure, two kinds of all ceramic restorations fabricated, included 108 anterior veeners and 370 full crowns were made, luting composite resins were used for seating the restoration. Results Patients total gratification achieved 93%, with the degree of comfort being the hightest which was achieved 100% and 96.65% restorations scored A using modified United States Public Health Service criteria, after three months of study and research. Conclusion It was found that all ceramic restoration may achieve the satisfied and stability result by using correct anterior mild malocclusion in adult.%目的 运用现代全瓷修复技术,通过短期治疗.,矫正成人轻度前牙错(牙合)畸形并达到临床美学修复的效果.方法 选择具有轻度拥挤或牙体变色及咬合不良,不愿或不适合进行长期正畸治疗,无烤瓷冠修复禁忌证的134例成年患者的478颗前牙进行全瓷修复体美学修复.首先制取研究模型,通过标准全瓷修复程序,制作全瓷修复体,包括全冠370个,贴面108个.使用光敏全瓷粘接树脂材料完成粘接.结果 通过3个月的临床追踪调查,修复患者的总满意度达到93%,舒适度达到100%,96.65%的修复体达到了美国公共健康协会修正标准结果中的A级标准.结论 全瓷修复体适用于矫正轻度牙列拥挤、变色或咬合关系错乱,因年龄等原因不再适宜运用正畸疗法的患者.

  6. Effect of different luting spaces on marginal fit of all-ceramic crowns%不同隙料厚度对全瓷冠适合性的影响

    Institute of Scientific and Technical Information of China (English)

    申丹凤; 王小林; 王璐; 吴恙; 徐凌

    2012-01-01

    目的 研究InLab MC XL系统不同隙料厚度对Cerec Blocs全瓷冠边缘和内部适合性的影响.方法 制备右上颌第一磨牙全冠预备体模型并翻制硅橡胶阴模,分别灌制全瓷石膏、超硬石膏预备体模型各30个.30个全瓷石膏预备体用于光学印模采集,获得30个数字化代型并完全随机分为6组分别设置不同隙料厚度值:0(A组)、10(B组)、20(C组)、30(D组)、40 μm(E组)和50 μm(F组),每组5个.30个超硬石膏预备体用于全瓷冠黏结,经包埋、剖开后,体式显微镜扫描试件剖面.结果 C、D组边缘适合性均介于30~ 120 μm,内部适合性均介于30 ~ 300 μm.C组与D组冠边缘适合性比较有统计学差异(P<0.05).C、D组冠内部适合性不均匀,(牙合)面适合性相对较大.结论 当隙料厚度为20、30 μm时,全瓷冠的边缘和内部适合性均在临床可接受范围内;30 μm的冠边缘适合性优于20 μm,但20、30 μm的冠(牙合)面适合性较差.%Objective To determine the effect of different luting spaces on marginal and internal fit of Cerec Blocs all-ceramic crowns in InLab MC XL system. Methods A right maxillary first molar in the standard model was prepared and subsequently replicated into silicone rubber negative mold. Respectively, 30 preparations of all-ceramic plaster and die stone were irrigated. Thirty all-ceramic plasters were used for optical impression, and then 30 three-dimensional digital images were obtained and randomly and equally divided into 6 groups, with their luting spaces were set to 0 (group A) , 10 (group B) , 20 (group C) , 30 (group D) , 40 (group E) and 50 um (group F) respectively by computer software. In addition, 30 die stones were prepared for bonding of the all-ceramic crowns. After being bonded, embedded and slitted, these specimens were scanned by stereo microscopy. Results The marginal fit was ranging from 30 to 120 um and the internal one from 30 to 300 um in groups C and D. There were

  7. 牙本质保护膜在全瓷冠牙体预备后的作用%The dental adhesive resin cement after dental preparation of all-ceramic crown

    Institute of Scientific and Technical Information of China (English)

    黄田河; 刘继华

    2012-01-01

    Objective To evaluate the protective effect of dental adhesive resin cement on dentin surface afterpreparation for all-ceramic crown.Methods 63 patients with 82 teeth prepared for all-ceramic crown were divided intogroups A and B in time sequence.Group A ( 32 patients,42 teeth )was applied with dental adhesive resin cement and group B ( 31 patients,40 teeth )was applied with Gluma desensitizer.Visual analog scale ( VAS )was used to assess th e sensitivity degree of the prepared teeth using tactile test and air blast test.The results were analyzed using a statistics software.Results In groups A and B,significant differences were found between the baseline VAS value of tactile test and air blast test ( pre-treatment ) and the value gained after both tests ( P< 0.05 ).No significant difference was fo und between group A and group B in the VAS value ( P> 0.05 ).Conclusions Dental adhesive resin cement can markedlyrelieve the symptoms of dentin hypersensitivity after dental preparation of all-ceramic crown.%目的 评价牙本质保护膜在全瓷冠修复的活髓牙备牙后牙本质面的保护作用.方法 选择63例行全瓷冠修复的患者,共82颗活髓牙,按就诊顺序随机分为A组和B组.A组32例(42颗牙),备牙后涂布牙本质保护膜;B组31例(40颗牙),备牙后涂布Gluma脱敏剂.采用可视分级评价法(VAS)评价探针刺激以及空气刺激预备牙的敏感程度.结果 A组:治疗前、后探针刺激以及空气刺激VAS值比较差异有统计学意义(P<0.05).B组:治疗前、后探针刺激以及空气刺激VAS值比较差异有统计学意义(P<0.05).A组和B组间,探针刺激以及空气刺激VAS值比较差异无统计学意义(P>0.05).结论 牙本质保护膜能显著降低全瓷冠修复的活髓牙牙体预备后的牙本质敏感症状.

  8. Clinical application of double gingival retraction technique for all- ceramic restorations of CAD / CAM.%改良化学机械去龋技术对援非人员龋病治疗评估

    Institute of Scientific and Technical Information of China (English)

    张敬雷

    2011-01-01

    Objection: To evaluate double gingival retraction technique of all-ceramic restorations in CAD/CAM.Method: 30 patients,48 restorations in CAD/CAM were used with double gingival retraction technique, observed gingival、prepared tooth, digital impression and all-ceramic restoration. Result: The rates of satisfaction with double gingival retraction were 97.91%,95.83 % and 100 %. Conclusion:Double gingival retraction technique was an effective method in CAD/ CAM restoration.%目的:总结便携式牙科电钻结合Carisolv技术的改良化学机械去龋方法对援非工作人员龋病的防治效果.方法:援非人员35例,54个龋齿,应用便携式牙科电钻、Carisolv工具及凝胶的改良微创去龋技术去龋备洞,玻璃离子充填,对治疗效果进行半年随访.结果:改良化学去龋技术去龋充填均顺利进行,48个牙获得成功,成功率88.9%.结论:改良化学去龋技术可用于无综合治疗台的简易环境中的龋病治疗,是边远地区理想、有效、便捷的一项应急龋病治疗方法.

  9. 上釉对IPS e.max全瓷修复体颜色及透射率的影响%Effect of glazing on the transmittance and color of IPS e.max all-ceramic restorations

    Institute of Scientific and Technical Information of China (English)

    刘晓艳; 韩影; 白乐康

    2015-01-01

    目的:探讨上釉对IPS e.max全瓷修复体颜色及透射率的影响.方法:将IPS e.max铸瓷材料制作成厚度为2.0mm、直径为15mm的圆盘状试件,测量其颜色及透射率后继续常规上釉、烧结,再次测量其颜色参数及透射率.结果:上釉后IPS e.max 全瓷修复体的a*、b*值增大,L*值、TP值无明显变化,上釉前后的色差ΔE小于1.5,透射率较上釉前有所降低.结论:上釉使IPS e.max全瓷修复体的色调偏向黄红,透射率呈降低趋势.%Objective To study the effect of glazing to the color and transmittance of IPS e.max all-ceramic restoration. Methods Make IPS e.max into 20 discal specimens with 15mm in diameter and 2.0mm thick.Then glaze,measure the L*a*b* color parameters and transmittance of specimens before and after glazing. Results After glazing,a* and b* values increase,the L* and TP values had no obvious change,ΔE value was less than 1.5,the transmittance reduced than before. Conclusion Glazing makes the color yellow and red.And the transmittance of IPS e.max all-ceramic restoration reduces after glazing.

  10. CEREC3D制作全瓷嵌体修复后牙Ⅱ类洞临床研究%Clinical study on CEREC3D all ceramic inlay restorations for posterior tooth

    Institute of Scientific and Technical Information of China (English)

    王忠朝; 范丽苑; 兰玉燕; 王频

    2015-01-01

    目的:探讨CEREC3D CAD/CAM系统制作全瓷嵌体修复后牙Ⅱ类洞的临床效果.方法:选取28例33颗Ⅱ类洞后牙,按照CEREC3D CAD/CAM系统标准程序制作全瓷嵌体,修复1年后复诊,由同一医师按照改良USPHS标准对修复体进行评价.结果:各项标准中表面质地最令人满意,达到A标准者为90.91%,其次是颜色匹配,达到A标准者为87.88%,外形稍差,边缘适合性表现最差,有2颗患牙嵌体有破裂.结论:CEREC3D CAD/CAM系统制作全瓷嵌体修复后牙Ⅱ类洞有较好的临床效果.%Objective To approach clinical effect of all ceramic inlay restorations fabricated by CEREC3D CAD/CAM system. Methods 28 patients with 33 all inlay restorations were involved in the study.After one year,the doctor make the clinical evaluation for the restorations using modified USPHS criteria. Results Among the results,the most satisfactory criteria was external texture,90.09%inlay restorations scored A using modified USPHS criteria.Second satisfactory color match problem that achieved 87.88%of A criteria.Margin fitness was worse,2 inlays burst. Conclusion It is satisfactory for classⅡcavity ofposterior tooth that all ceramic inlay wag made by CEREC3D CAD/CAM system.

  11. Clinical evaluation of selective double gingival retraction technique for anterior all-ceramic crown prosthesis%选择性双线排龈技术在前牙全瓷冠修复中的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘思言; 牟雁东

    2016-01-01

    目的:评价选择性双线排龈技术在前牙全瓷冠修复中的临床应用效果。方法选择126例门诊患者258颗前牙行全瓷冠修复,简单随机法分为两组各63例,试验组130颗基牙采用选择性双线排龈技术排龈,对照组128颗采用单线排龈技术排龈,评价牙龈止血效果满意率、预备体边缘和肩台暴露、游离龈与牙面分离满意率。结果选择性双线排龈技术的牙龈止血效果满意率、预备体边缘和肩台暴露、游离龈与牙面分离满意率分别为96.92%、96.15%及95.38%,明显高于单线排龈技术的83.59%、82.03%及81.25%。差异有统计学意义( P<0.05)。结论在前牙全瓷冠修复中,选择性双线排龈技术有很好的临床应用效果。%Objective To evaluate the clinical application effect of selective double gingival retraction technique for anterior all-ceramic crown prosthesis .Methods Two hundred and fifty-eight anterior all-ceramic crowns from 126 patients were randomly divid-ed into experimental or control groups ,63 cases in each group.Selective gingival retraction technique was used in the experimental group (130 teeth) while singlet gingival retraction technique was used in the control group (128 teeth).The effect on satisfaction rates of gingival hemostasis ,prepared teeth margins and shoulder exposure ,and satisfaction rates of separation of free gingiva and tooth sur-face were evaluated .Results The rates of satisfaction of gingival hemostasis ,prepared teeth margins and shoulder exposure and separa-tion of free gingiva and tooth surface in the selective double gingival retraction group were 96.92%,96.15%and 95.38%,respective-ly,that were significantly higher than that with singlet gingival retraction technique (83.59%,82.03%and 81.25%,respectively) (P<0.05 ) .Conclusion Selective double gingival retraction technique is an effective method for anterior all -ceramic crown prosthesis .

  12. 切牙单端铸瓷粘接桥的临床应用初探%Clinical application of anterior all-ceramic cantilevered resin-bonded fixed partial dentures

    Institute of Scientific and Technical Information of China (English)

    张磊; 聂宇光; 谢秋菲

    2008-01-01

    Objective To explore a fabricating method of incisor all-ceramic cantilevered resinbonded fixed partial denture(RBFPD)and evaluate their clinical performances.Methods All-ceramic cantilevered RBFPDs were made to replace 1 missing incisor in each of 10 patients.The RBFPDs with lingual surface retainer were made of Empress Ⅱ ceramic materials and luted with resin cement.The prostheses were examined at 2 weeks,1 year and 2 years after denture insertion.Examining criteria included:fracture of bridge,marginal adaptation,secondary caries,and color match.Results The average follow-up period was 14.7 months.No framework fracture and retainer debonding were observed and margihal adaptation was evaluated as good.Seven RBFPDs matched the color of adjacent teeth,and other three did not match well but within the acceptable range of tooth shade difference.Conclusions The results of this preliminary study suggest that the clinical performances of all-ceramic cantilevered RBFPDs are good in short-term evaluation,but their long-term success needs to be further investigated.%目的 探索切牙单端铸瓷粘接桥的治疗方法,观察其临床效果,以期为单端粘接桥的临床应用提供参考.方法 选择单颗切牙缺失病例10例,制作舌侧翼板固位的单端铸瓷粘接桥,共制作10件粘接桥,分别于修复后2周、1年、2年复查,复查内容包括:修复体折裂情况、边缘适合性、继发龋、颜色匹配性.结果 10例患者平均观察14.7个月.10件单端铸瓷粘接桥均无支架及饰瓷折断、裂纹,无松动;10颗基牙和固位体边缘密合,无边缘着色,无继发龋;7例修复体颜色匹配为A级,3例修复体颜色匹配为B级.结论 单端铸瓷粘接桥可修复单颗切牙缺失,牙体组织磨除量小,短期内临床效果良好,但其强度及粘接效果能否满足临床要求尚需进一步观察.

  13. IPS e.max Press全瓷冠和三单位固定桥的临床评价%Clinical evaluation of IPS e.max Press all-ceramic crowns and three-unit fixed partial dentures

    Institute of Scientific and Technical Information of China (English)

    郭玲; 郑树灿; 罗祖凤; 覃峰; 徐亚娟; 付强

    2009-01-01

    Objective To evaluate the clinical performance of IPS e.max Press all-ceramic crowns and three-unit fixed partial dentures(FPDs)and to investigate the periodontal response to the presence of the restorations.Methods According to the inclusion criteria,19 patients with dental defects or singletooth loss were recruited,including 25 crowns and 6 all-ceramic FPDs.The modified United States Public Health Service criteria were used for follow-up evaluation.Plaque index(PI)and sulcus bleeding index (SBI)were recorded for the ceramic restorations and the control teeth.Results No crown and FPD fractures were observed during the evaluation period.There was no statistically significant difference regarding PLI and SBI scores between restorative teeth and the control teeth.And the difference between different recalled times of PLI and SBI of the restorations was no statistically significant.Conclusion IPS e.max Press crowns and three-unit fixed partial dentures exhibit a satisfactory clinical performance.%目的 探讨在牙科美容修复中应用IPS e.max Press全瓷冠桥的临床疗效及其对基牙牙周组织的影响,总结相关影响因素.方法 采用前瞻性研究的方法,对符合纳入标准的19例患者行IPS e.max Press全瓷冠或全瓷三单位固定桥修复,其中全瓷冠25例,全瓷三单位固定桥6例,参照改良美国公共健康协会标准,对其临床效果进行追踪评价,并记录修复体及对照牙菌斑指数(plague index,PLI)及龈沟出血指数(suleus bleading index,SBI).结果 经过3~12个月的临床追踪观察,无1例IPS e.maxPress修复体松动、折裂、脱落或被替换,修复体组和对照牙组的PLI及SBI的差异无统计学意义,修复体组在不同复诊时间PLI及SBI前后差异无统计学意义.结论 IPS e.max Press全瓷冠桥可获良好的近期临床效果.

  14. Clinical outcome of implant-supported all-ceramic fixed partial prostheses for posterior tooth restoration%氧化锆全瓷固定桥在后牙种植修复中的临床效果观察

    Institute of Scientific and Technical Information of China (English)

    解涓; 林盛筱; 谢超; 刘艳; 宋应亮; 马威; 李德华

    2014-01-01

    目的:对氧化锆全瓷固定桥在后牙种植区的临床应用效果进行初步评估。方法:随访2011-07~2012-06采用种植体支持的全瓷固定桥修复后牙缺失的47位患者(53个修复体,共120枚种植体)的临床资料。记录种植体的失败数量、修复体失败数量、机械及生物并发症情况。结果:37例43个修复体、100个种植体随访12~24个月。随访病例中共有9个修复体(20.9%)出现崩瓷,9颗种植体(9.0%)存在种植体周围黏膜炎。修复体存留率100%,种植体存留率100%。所有种植体和修复体均未出现松动、脱落、折断等现象。结论:种植体支持的氧化锆全瓷固定桥用于后牙种植修复是可行的。%Objective:To evaluate the outcome of implant-supported all-ceramic fixed partial prostheses (FPPs)in posterior area. Methods:The clinical data of 1 20 implants-supported 53 fixed dentures in 47 patients were collected from July 201 1 to June 201 2 and prospectively studied.Complication and failure of implants and /or prosthesis,biological and technical complications were evaluated. Results:43 restorations with 1 00 implants in 37 cases were followed up for 1 2 -24 months.Veneering ceramic chipping was observed in 9(20.9%)prostheses.Inflamed marginal gingivitis was found around 3(7.0%)prostheses.No implant was involved in technical complication.Cumulative survival rate was 1 00% for implant-based analysis and 1 00% for prostheses-based analysis.Conclusion:Implant-supported all-ceramic fixed partial dentures may be a feasible treatment modality for posterior dental restoration.

  15. ALL CERAMIC VENEERS: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Dileep Soni

    2016-07-01

    Full Text Available Porcelain veneers are one of the best restorative treatment options available from biological, functional, mechanical and esthetic perspectives. The use of porcelain laminate veneers to solve esthetic and/or functional problems has been shown to be a valid management option, especially in the anterior esthetic zone. The present case reports the case of attrition, anterior teeth in a healthy dentition by means of sectional porcelain veneers simply cemented onto the natural teeth and with minimal tooth preparation. In cases when patients decline orthodontic treatment, adhesively bonded porcelain veneers are a viable treatment

  16. Enhanced aesthetics with all ceramics restoration.

    Science.gov (United States)

    Nayar, Sanjna; Aruna, U; Bhat, Wasim Manzoor

    2015-04-01

    The demand for the dentist to achieve excellence in esthetics and function has driven modern advances in materials and restoration fabrication. The development of various casting alloys and precise casting systems has contributed to the successful use of metal-based restorations. However, patient requests for more aesthetic and biologically "safe" materials that have led to an increased demand for metal-free restorations. The following case presentation illustrates a successful aesthetic and functional application of this exciting computer-aided design/computer-aided manufacturing-digital zirconia-based system for a natural smile. PMID:26015733

  17. Enhanced aesthetics with all ceramics restoration

    Directory of Open Access Journals (Sweden)

    Sanjna Nayar

    2015-01-01

    Full Text Available The demand for the dentist to achieve excellence in esthetics and function has driven modern advances in materials and restoration fabrication. The development of various casting alloys and precise casting systems has contributed to the successful use of metal-based restorations. However, patient requests for more aesthetic and biologically "safe" materials that have led to an increased demand for metal-free restorations. The following case presentation illustrates a successful aesthetic and functional application of this exciting computer-aided design/computer-aided manufacturing-digital zirconia-based system for a natural smile.

  18. Enhanced aesthetics with all ceramics restoration

    OpenAIRE

    Sanjna Nayar; Aruna, U.; Wasim Manzoor Bhat

    2015-01-01

    The demand for the dentist to achieve excellence in esthetics and function has driven modern advances in materials and restoration fabrication. The development of various casting alloys and precise casting systems has contributed to the successful use of metal-based restorations. However, patient requests for more aesthetic and biologically "safe" materials that have led to an increased demand for metal-free restorations. The following case presentation illustrates a successful aesthetic and ...

  19. 瓷修复体循环疲劳失效行为的实验研究方法%Experimental research methods in fatigue failure behavior of dental all-ceramic restorations

    Institute of Scientific and Technical Information of China (English)

    潘娱

    2011-01-01

    牙科陶瓷材料的原始断裂强度远高于口腔正常咬合力,但由于材料的低应力疲劳破坏行为,致使全瓷修复体在口腔长期反复咀嚼功能状态下仍会出现崩裂。采用循环疲劳试验方法分析全瓷修复体的疲劳失效行为,可为其临床可靠性评价和寿命预测提供有力依据。体外实验方法和参数选择对研究口腔修复体循环疲劳失效行为至关重要。%In spite of the strength of dental ceramics far exceeds the occlusal stress, one severe concern for all-ceramic systems is their susceptibility to fatigue damage caused from long-term mastication. Mechanical simulation of a laboratory test is often used for pre-clinical investigations of dental materials and restorations, aiming at describing the fatigue behavior and predicting the catastrophic failures. This article presents a review of the experimental methods in research of dental restorations.

  20. 换热器管板角焊缝相控阵自动超声检测技术研究%Research on Phased Array Automatically Ultrasonic Testing Technique of Tube to Tube-sheet Welds in Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    郭伟灿; 钱盛杰; 凌张伟

    2015-01-01

    在换热器的制作过程中,换热管与管板常采用焊接形式,焊缝的质量是保证换热器长期正常运行的关键。常规的超声检测方法具有系统复杂、检测效率低等缺点。因此,提出了相控阵超声检测技术,并开发了相控阵超声检测系统,以实现对管板角焊缝的自动超声检测。系统由周向步进电机实现周向扫查,纵向扫查采用相控阵探头电子线扫查,从而实现超声 C 扫描检测。通过带有气孔、未熔合等典型缺陷对检测系统进行试验研究。结果表明,该技术可以有效地检测出换热器管板角焊缝中的典型缺陷。%In the process of produce heat exchangers,heat exchanger′s tube and tube sheet conjunction adopt the form of welding,the quality of welding is the key insurance for the long and normal operation of the heat exchangers.The conventional ultrasonic testing method has many disadvantages like complicated system and low efficiency of detection.Thus,it puts forward the phased array ultrasonic testing technique and develops the ultrasonic testing system to accomplish the automatically ultrasonic testing of the tube to tube-sheet welds.The ultrasonic C-scan was carried out by the ultrasonic testing system with its circumfer-ential scanning by a mechanical scanning device while the axial electronic linear scanning by the phased array probe.At last,the tests on samples with typical flaws such as porosity flaws and the incomplete fu-sion flaws were performed by the ultrasonic testing system.Experiment results showed that the phased ar-ray ultrasonic technique could effectively detect the typical flaws in the tube to tube-sheet welds of heat exchanger.

  1. Numerical simulation of flow and heat transfer in double tube-double tubesheet heat exchanger%双套管双管板换热器流动及传热性能数值模拟

    Institute of Scientific and Technical Information of China (English)

    周玲; 刘雪东; 李岩; 梁立军; 刘莺歌

    2011-01-01

    Heat transfer and flow behavior of double tube-double tubesheet heat exchanger were studied by CFD method. The simulation of heat transfer was performed by filling the safety chamber and the annular gap between inside and outside tubes with four different media including air, water, toluene gas and argon. The result shows that different media lead to different heat transfer results. Among which water has the best effect for heat transfer, while toluene is the worst. Backflow and around flow exist in both inlet and outlet pipe nozzles of shell side, and the fluid in tube side is well-distributed. Because of the wall boundary layer effects, the velocity is higher at the center but is lower near the wall. Different Reynolds number results in different overall heat transfer coefficients. Compared with the theoretical formula results, the simulation results are better by 15%-30%. The existing formula of overall heat transfer coefficient is not suitable for double tube-double tubesheet heat exchanger. The optimization of conventional calculation by simulating and experimental method is the focal task in the future.%采用CFD软件方法,研究双套管双管板换热器传热及流动特性.对隔绝腔连同内外套管的环形间隙内分别充入空气、水、甲苯气体和氩气4种介质进行模拟.结果表明:不同介质对传热有不同影响,充入水时的换热效果最好,甲苯气体的最差;壳程介质在流体接管进、出口附近存在回流和绕流且速度较小,管程介质流动较为均匀,受壁面边界层影响,速度在管中心处较高,在管壁处较低;采用模拟和传统计算方法分别得到不同雷诺数下的总传热系数,模拟得到的值比用常规设计计算结果好15% -30%,因此传统计算公式不能很好地解决此类换热器在实际中应用问题,通过模拟实验等手段优化传统计算方法是今后研究重点.

  2. Comparison of Different Gingival Retraction Techniques for Zirconia All-Ceramic Restorations%不同排龈方法对氧化锆全瓷冠临床修复效果的影响

    Institute of Scientific and Technical Information of China (English)

    夏芬

    2015-01-01

    Objective To evaluate the effects of different gingival retraction techniques on zir-conia all-ceramic restorations.Methods Totally 120 teeth were randomly treated with one-cord retraction technique,two-cord retraction technique or Er,Cr:YSGG laser,with 40 teeth in each group.The situation of preparation,gingival bleeding,impression and restoration adaptation were compared among the three groups.Furthermore,gingival health was evaluated 3 months after treatment.Results There were no significant differences in the satisfaction with impression and master cast and the gingival health among the three groups (P >0.05).The two-cord retraction technique achieved a higher satisfaction with tooth preparation than other techniques (P <0.05). Er,Cr:YSGG laser and one-cord retraction technique achieved the highest and lowest satisfaction with hemostatic effect,respectively (P <0.01).Conclusion All the three gingival retraction tech-niques are effective for zirconia all-ceramic restorations.However,Er,Cr:YSGG laser has better hemostatic effect than cord retraction technique,and two-cord retraction technique is more effec-tive for tooth preparation than one-cord retraction technique.%目的:评价不同排龈方法对氧化锆全瓷冠临床修复效果的影响。方法将120颗需修复的牙按随机数字表法分为单线排龈组、双线排龈组和激光排龈组,每组40颗牙。单线排龈组用单线排龈法排龈,双线排龈组用双线排龈法排龈,激光排龈组用 Er,Cr:YSGG 激光排龈。对3组的牙预备体、牙龈止血效果、印模、修复体适应性及3个月后牙龈状况进行评估。结果3组印模、模型满意度以及3个月后牙龈健康状况比较差异无统计学意义(P>0.05);双线排龈组牙体预备满意度高于其他2组(P <0.05);激光排龈组止血效果满意度最高,单线组最低(P <0.01)。结论3种排龈方法均能取得较好的临床修复效果,激光排龈止血

  3. 全瓷牙在前牙美容修复中的应用体会%Clinical experience with the application of all-ceramic dental restoration of anterior teeth beauty

    Institute of Scientific and Technical Information of China (English)

    朱芒

    2014-01-01

    Objective Cosmetic restoration of anterior teeth in the clinical effects of the application of porcelain teeth, Summarize the clinical experience Methods Our hospital in January 2012 to June 2012 Anterior tooth of 56 patients for the study, 28 cases were randomly selected as a control group, another 28 cases as the observation group and control group patients metal alloy porcelain repair, observe group of patients with all - ceramic dental restoration, repair effect two groups were compared. Results After the restoration of the two groups of patients overall appearance, countenance improve aspects of color and shape, psychological improvement prostheses were significant differences ( <0.05); incidence of periodontitis and gingivitis patients in the observation group were significantly lower in the control group ( <0.05). Conclusion Anterior tooth application of porcelain teeth can achieve the desired aesthetic effect, and higher security, significant clinical value.%目的:探讨前牙美容修复中应用全瓷牙的临床效果。方法:选取我院收治的56例行前牙美容修复治疗的患者,从中随机抽取28例作为对照组,另28例作为观察组,对照组患者采用金属合金烤瓷修复,观察组患者则采用全瓷牙修复,并对两组患者的修复效果进行比较。结果:两组患者修复后其整体美观、面容改善、修复体色泽及外形、心理改善等方面比较,均有较大的差异(P<0.05),有统计学意义;且观察组患者的牙周炎及牙龈炎发病率均显著低于对照组(P<0.05)。结论:采用全瓷牙进行前牙美容修复可取得理想的美学效果,且安全性较高,其临床价值显著,应予广泛应用。

  4. Evaluation of alumina effects on the mechanical property and translucency of nano-zirconia all-ceramics%添加相氧化铝对牙科纳米氧化锆陶瓷性能的影响

    Institute of Scientific and Technical Information of China (English)

    蒋丽; 赵永旗; 张静超; 廖运茂; 李伟

    2010-01-01

    目的 通过测定不同Al2O3含量的牙科纳米氧化锫复合陶瓷材料的烧结密度、力学性能和可见光积分透射比,探讨Al2O3添加量对复合陶瓷力学性能及半透明性的影响.方法 分别测量Al2O3质量百分数分别为2.5%、5.0%、7.5%、10.0%的Al2O3组和对照组(不含Al2O3)氧化锆陶瓷试件的烧结密度、三点弯曲强度和断裂韧性,采用分光光度计测量可见光积分透射比,扫描电镜观察试件断面形貌.结果 对照组试件常压烧结下烧结密度为(6.04±0.03)g/cm3,接近理论密度,三点弯曲强度为(1100.27±54.82)MPa,断裂韧性为(4.96±0.35)MPa·m1/2,透射比高达17.03%;2.5%、5.0%、7.5%、10.0%Al2O3组随Al2O3含量的增加,试件的烧结密度和透射比下降,断裂韧性有所提高;Al2O3 4组间三点弯曲强度的差异无统计学意义(P>0.05);10.0%Al2O3组试件的断裂韧性为(6.13±0.44)MPa·m1/2,透射比明显降低至6.21%.Al2O3对四方氧化锆晶粒的大小和分布无明显影响.结论 添加Al2O3可影响氧化锆复合陶瓷的力学性能和半透明性,添加复合相需兼顾临床对陶瓷材料力学性能和透光性的要求.%Objective To study the effects of alumina content on sintered density, mechanical property and translucency of zirconia nanocomposite all-ceramics. Methods Specimens of zirconia nanocomposite all-ceramics were divided into five groups based on their alumina content which are 0% (control group), 2. 5% , 5. 0% , 7. 5% and 10. 0% respectively. The sintered densities were measured using Archimedes' method. Specimens' bending strengths were measured with three-point bending test( ISO 6872). The visible light transmittances were measured with spectrophotometric arrangements and the fractured surfaces were observed using scanning electron microscope (SEM).Results The control group of pure zirconia could be sintered to the theoretical density under pressure-less sintering condition. The bending strength was (1100.27 ±54

  5. 有限元方法模拟不同全瓷冠破坏过程初探%Analysis of the fracture processes in all-ceramic crowns by finite element analysis

    Institute of Scientific and Technical Information of China (English)

    刘亦洪; 冯海兰; 包亦望; 邱岩

    2008-01-01

    目的 用有限元方法模拟不同材料和形态的基底冠全瓷冠破坏过程,分析材料和形态对全瓷冠破坏机制的影响.方法 分别建立均匀厚度、不均匀厚度、带颈环3种基底冠形态的氧化铝和氧化锆全瓷冠模型,用BFPA'2D有限元分析软件模拟加载后全瓷冠的破坏过程.结果 6种模型均由拉应力引发破坏,裂纹始于牙尖顶的饰瓷表面,并沿基底冠与饰瓷的界面扩展.在本项研究加载条件下,仅饰瓷破坏,无基底瓷破坏,加载压强5 MPa时氧化锆模型破坏,加载6 MPa时氧化铝模型破坏.加载开始时有颈环模型呈现颈环处最小主应力集中,不均匀厚度基底冠模型呈现颈部最大主应力集中.结论 氧化锫模型的基底瓷与饰瓷界面存在更大的应力.不均匀厚度基底冠设计未增加全瓷冠破坏的风险,有颈环基底冠模型的颈部是拉应力集中的薄弱环节.%Objective To analyze the effects of core material and design on the fracture mechanism of veneered all-ceramic crowns. Methods The fracture process of 6 veneered alumina or zirconia crowns with different core design (well-distributed core, not well distributed core, and core with cervical ring) under load was analyzed by RFPA'2D finite element analysis software. Results All the six tested crowns fractured due to tension failure, and the crack started at the porcelain in the cusp and spread along the interface between core and porcelain. Under the conditions of this test, the break was only related to the porcelain and not the core, and the crack of porcelain took place earlier in zirconia crowns than in alumina crowns. Minimum stress distribution in cervical ring core design crown and maximum stress distribution in not well distributed core design crown could be seen at the neck area. Conclusions Zircania crowns presented greater stress at the interface between core and porcelain than alumina crowns. The not well distributed core design did not

  6. 3种全瓷系统冠边缘适合性的比较%A comparison of three-dimensional marginal adaptation among three all-ceramic crown systems

    Institute of Scientific and Technical Information of China (English)

    张艳; 李江; 薛小琴; 陈振宇; 李小菊

    2011-01-01

    m and 85.1μm. CONCLUSIONS: The horizontal marginal discrepancies, vertical marginal discreparicies and absolute marginal discrepancies of the three all-ceramic crown systems were within the clinically acceptable standard. However, the IPS e.max system and the Kavo Everest System showed a better marginal fit compared with the In-Ceram alumina system. Supported by Grant from Science and Technology Projects of Changchun City(06GG163).

  7. The effects of firing numbers on the opening total pore volume, translucency parameter and color of dental all-ceramic systems%烧结次数对牙科全瓷开放性总孔体积、透明度和色度的影响

    Institute of Scientific and Technical Information of China (English)

    李水根; 庞莉苹; 姚江武

    2012-01-01

    目的 评价烧结次数对牙科全瓷开放性总孔体积(TPV)、透明度(TP)和色度的影响.方法 采用热压全瓷(IPS Empress Ⅱ)、氧化铝全瓷(In-Cream alumina blanks)和氧化锆全瓷(Cercon CAD/CAM zirconia)3种材料制作试样,使用分光光谱仪与表面积和孔隙率仪测量计算试样经过1、3、5次烧结后的TP、明度(ΔL)、彩度(ΔC)和TPV变化.应用SAS 8.0软件对数据进行统计分析.结果 相同烧结次数下,3种全瓷试件的TPV、TP、ΔL和ΔC间均存在统计学差异(P<0.05),其中TPV为热压全瓷大于氧化铝全瓷和氧化锆全瓷(P<0.05);TP和ΔL均为热压全瓷最高,氧化锆全瓷其次,氧化铝全瓷最低(P<0.05);ΔC为热压全瓷和氧化铝全瓷大于氧化锆全瓷(P<0.05).不同烧结次数下,同一全瓷试件TPV、TP、ΔL和ΔC间也存在统计学差异(P<0.05).随着烧结次数的增加,TPV逐渐减小,TP、ΔL和△C逐渐增加.烧结次数与TPV、TPV与TP和ΔL均呈负相关(P<0.05).结论 重复烧结可通过TPV变化影响全瓷修复体的TP和ΔL的稳定性.%Objective To evaluate the effects of firing numbers on the total opening pore volume (TPV), translucency parameter (TP) and color of dental all-ceramic systems. Methods Specimens of three kinds of all-ceramics systems were made, i.e. heat pressed all-ceramic (IPS Empress E), alumina all-ceramic (In-Cream alumina blanks) and zirconia all-ceramic (Cercon CAD/CAM zirconia). The specimens' TP, lightness (AL), chroma (AC) and TPY after 1, 3 and 5 firings were measured and calculated by spectrophotometer and surface area/porosity system. The data were analyzed statistically using SAS 8.0 software. Results There were significant differences in TPV, TP, AL and AC for all-ceramic specimens at same number of firings (Palumina and zirconia for TPV(Pzirconia>alumina for TP and AL(Pzirconia for AC(P<0.05). The significant differences also presented in TPV, TP, AL and AC for a same specimen at different

  8. 前牙IPS热压铸造全瓷粘接桥修复的3年临床应用研究%All-ceramic resin bonded fixed partial denture made of IPS hot-pressed casting porcelain restore anterior missing teeth: a three years clinical observation

    Institute of Scientific and Technical Information of China (English)

    周团锋; 王新知; 张桂荣

    2011-01-01

    Objective :To clinic observation of IPS Empress2 and IPS e. max all ceramic resin bonded fixed partial dentures used in one anterior teeth lost in upper jaw or less than two anterior tooth lost in lower jaw. Methods : 22 patients, 26 restorations had been made, which included 16 single-retainer all ceramic resin bonded fixed partial dentures and 10 two-retainers all ceramic resin bonded fixed partial dentures. Secondary caries of the abutments, shade in the margin of the retainers and the integrity of the restorations had been observed at 3 months, 6 months, 1 year, 2 years and 3 years after all ceramic resin bonded fixed partial dentures having been bonded. Results : In the 3 years of clinic observation of the anterior all ceramic resin bonded fixed partial dentures, 1 two-retainers restoration lost bond after it had been made for 3 months, a retainer of one two-retainers restoration was broken after 6 months, but they are still used after modified as one-retainer all ceramic resin bonded fixed partial dentures, 1 two-retainers restoration lost bond two year later, It was integrity and re-bonded again that was still stable. No secondary carries and no shade in margin of the retainers had been found. Their color matches with the nature teeth excellently. The success rate was 88.5% . Conclusion: IPS Empress 2 and IPS e. max all ceramic resin bonded fixed partial dentures should be a good selection in one or two teeth lose in anterior jaws.%目的:观察单个上前牙或下颌2个以内前牙缺失采用IPS Empress 2或IPS e.max热压铸造全瓷粘接桥的临床修复效果.方法:22位患者,共制作26件前牙热压铸造全瓷粘接桥,包括16例单翼全瓷粘接桥和10例双翼全瓷粘接桥,修复后3个月、6个月、1年,2年和3年观察修复体的完整性,基牙的继发龋,边缘着色及修复体的颜色匹配.结果:1例双翼全瓷粘接桥修复后3个月脱落;1例双翼全瓷粘接桥6个月后一侧连接体折断,均改为单翼

  9. Sequence assembly

    DEFF Research Database (Denmark)

    Scheibye-Alsing, Karsten; Hoffmann, S.; Frankel, Annett Maria;

    2009-01-01

    and plays an important role in processing the information generated by these methods. Here, we provide a comprehensive overview of the current publicly available sequence assembly programs. We describe the basic principles of computational assembly along with the main concerns, such as repetitive sequences...

  10. Clinical therapeutic effect comparison between Sirona Cerec 3D all-ceramic crowns and porcelain fused to metal crown in anterior teeth restoration%Sirona Cerec3D全瓷冠与金属烤瓷冠修复前牙的临床对比

    Institute of Scientific and Technical Information of China (English)

    汤琼

    2012-01-01

    目的 评价Sirona Cerec 3D全瓷冠进行前牙修复的临床效果.方法 将81例(145颗前牙)患者进行随机分组,参照美国加利福尼亚牙科协会(CDA)评价标准,对使用1年的牙冠进行评价,并与同期治疗的金属烤瓷冠进行对比.结果 Sirona Cerec 3D全瓷冠修复组在边缘完整性、解剖外形、颜色和表面的成功率分别为97.5%、95%、100%、97.5%,而金属烤瓷冠对照组成功率为97.6%、92.6%、87.8%和95.1%.修复组在解剖外形和颜色方面明显优于对照组(P<0.05),且牙龈炎等副反应发生率小.结论Sirona Cerec 3D全瓷冠进行前牙修复效果良好,值得临床广泛推广.%Objective To evaluate the clinical therapeutic effect ofSirona Cerec 3D all-ceramic crowns in anterior teeth restoration.Methods 81 patients(145 anterior teeth) were divided randomly into two groups.The clinical evaluation criteria of CDA was performed 6 months to two years after wearing.And we compared the effects with porcelain fused to metal (PFM) crowns in the same period.Results On the integrity of crown margin,anatomical shape,color and surface,the succeed rate of all-ceramic crowns group were 97.5%,95%,100% and 97.5% respectively while PFM crowns group were 97.6%,92.6%,87.8% and 95.1% respectively.All-ceramic crowns group was better than PFM crowns group on the anatomical shape and color ( P < 0.05 ) and had less side effects.Conclusion Sirona Cerec 3D all-ceramic crowns has a good effect in anterior teeth restoration,worthy in expanded clinical use.

  11. Furnace assembly

    Science.gov (United States)

    Panayotou, Nicholas F.; Green, Donald R.; Price, Larry S.

    1985-01-01

    A method of and apparatus for heating test specimens to desired elevated temperatures for irradiation by a high energy neutron source. A furnace assembly is provided for heating two separate groups of specimens to substantially different, elevated, isothermal temperatures in a high vacuum environment while positioning the two specimen groups symmetrically at equivalent neutron irradiating positions.

  12. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    5th April, 2016 – Ordinary General Assembly of the Staff Association! In the first semester of each year, the Staff Association (SA) invites its members to attend and participate in the Ordinary General Assembly (OGA). This year the OGA will be held on Tuesday, April 5th 2016 from 11:00 to 12:00 in BE Auditorium, Meyrin (6-2-024). During the Ordinary General Assembly, the activity and financial reports of the SA are presented and submitted for approval to the members. This is the occasion to get a global view on the activities of the SA, its financial management, and an opportunity to express one’s opinion, including taking part in the votes. Other points are listed on the agenda, as proposed by the Staff Council. Who can vote? Only “ordinary” members (MPE) of the SA can vote. Associated members (MPA) of the SA and/or affiliated pensioners have a right to vote on those topics that are of direct interest to them. Who can give his/her opinion? The Ordinary General Asse...

  13. 两种粘结剂粘结CAD/CAM氧化锆全瓷冠边缘微渗漏的研究%A comparative study of marginal microleakage using two kinds of cements in CAD/CAM zirconia all ceramic crown

    Institute of Scientific and Technical Information of China (English)

    梁天文; 王珏; 李英

    2012-01-01

    目的 评价两种不同粘结剂在CAD/CAM氧化锆全瓷冠修复中的边缘微渗漏情况.方法 制作10个CAD/CAM氧化锆全瓷冠,随机分成2组,分别采用磷酸锌水门汀粘结剂和Panavia F树脂粘结剂粘固于前磨牙,经温度循环试验后,将样本浸入2%品红溶液中24h,用体视显微镜观察牙-粘结剂界面边缘微渗漏状况,并进行分级评估.结果 采用SPSS 17.0软件对2组的微渗漏程度进行统计分析,得出Panavia F树脂粘结剂微渗漏小于磷酸锌水门汀粘结剂(x2=81.142,P<0.05).结论 Panavia F树脂粘结剂具有较优越的抗边缘微渗漏性能.%Objective To evaluate the marginal microleakage of CAD/CAM zirconia all ceramic crown using two different cements. Methods Ten CAD/CAM zirconia all ceramic crowns were built and randomly divided into two groups, cohered onto standard prepared human forward molars using two different cements (zinc phosphate cement and Panavia F resin cement). After temperature cycling test, all the crowns were then submerged in 2% fuchsin for 24h. The marginal microleakage at tooth cement interfaces was observed using light stereomicroscopy and evaluated in classification index. Results The marginal microleakage grade of two groups were analyzed by SPSS 17.0. The result showed that the marginal microleakage of Panavia F was less than zinc phosphate cement (x2=81.142,P<0.05). Conclusion Panavia F resin cement was suited to cement CAD/CAM zireonia all ceramic crown.

  14. Clinical application of the surgical crown lengthening combining all ceramic crown after failure of the anterior teeth PFM crown restoration%牙冠延长术结合全瓷冠修复在前牙烤瓷冠失败病例的应用

    Institute of Scientific and Technical Information of China (English)

    李雪峰

    2013-01-01

    目的:探讨应用牙冠延长术结合全瓷冠技术治疗前牙生物学宽度不足导致不良烤瓷冠修复的临床疗效。方法选取26例因生物学宽度不足导致的前牙修复失败病例,进行完善牙周治疗,根管治疗,并进行牙冠延长术后全瓷冠修复,观察术前,术后六周以及修复后三个月以及修复六个月的PD(探诊深度), SBI(出血指数)并予以记录。结果24例患者治疗效果较好,两例术后牙龈高度不对称,患者不甚满意。结论牙冠延长术结合全瓷冠修复可以较好的解决前牙不良烤瓷冠修复的再治疗问题。%Objective To investigate the effect after crown lengthening surgery combining all ceramic crown on anterior teeth failure of PFM crown restoration because of insufficient biological width Methods Select 26 failure cases of anterior teeth caused by insufficient biological width , repair to perfect the periodontal treatment, root canal treatment, and crown lengthening surgery. After treatment all teeth were restored by all ceramic crown, At baseline, 6 weeks after surgery and 3 months and 6 months after the restoration BOP and PD were recorded and analyzed. Results 24 patients treatment effect is good, two cases of postoperative were not very satisfied because of gum hight asymmetric. Conclusion Crown lengthening sursery combining all ceramic crown restoration can solve the failure PFM restoration on anterior teeth.

  15. Evaluation of the effect of zirconia all-ceramic fixed dental prostheses designed and manufactured by CAD/CAM in restoration of posterior teeth%CAD/CAM二氧化锆全瓷固定桥的修复效果评价

    Institute of Scientific and Technical Information of China (English)

    宓勇

    2015-01-01

    To observe the 36 months follow-up outcome of zirconia all-ceramic posterior fixed dental prostheses(FDPs)designed and manu-factured by computer aided design and computer aided manufacture (CAD /CAM)from clinical aspect,and to evaluate the success rate of zirconia framework and veneering porcelain.78 patients with less than three teeth lost which had natural opposing teeth were included.A to-tal of ninty-two zirconia all-ceramic FDPs (59 three-unit FDPs,20 four-unit FDPs and 13 five-unit FDPs)were made by CAD /CAM.Three years after cementation of the restorations,the reasons for complication and failure of FDPs in different lengths were analysed.Six FDPs were removed (frame fracture:1;porcelain fracture:1;secondary caries:2;vertical root fractures and post-core fracture after root canal therapy of premolars:2).The success rate of these FDPs was 93.5%.The success rate of zirconia all-ceramic crowns and bridges was higher.Their clinical effect was satisfactory.The main complications of these FDPs were porcelain fracture and de-bonding.%选择78名口内最多缺失2颗牙且存在对颌牙用 CAD/CAM氧化锆固定桥修复的患者,制作92件固定桥:3单位桥59件,4单位桥20件,5单位桥13件。在修复体粘接后,随访3年,分析不同长度的全瓷桥并发症的发生和失败原因的差异。6件固定桥需要拆除,修复成功率93.5%;1例因支架断裂拆除,1例由于崩瓷面积较大而拆除,2例因继发龋脱落而不能重新粘接,另外 2例前磨牙根管治疗后牙根纵裂和核折断导致修复失败。二氧化锆全瓷冠桥具有较高的成功率,临床效果满意,主要并发症是崩瓷和脱粘接。

  16. CAD/CAM全瓷嵌体与复合树脂嵌体修复后牙II类洞临床疗效对比分析%Comparison of clinical efficacy of CAD/CAM all-ceramic inlay and composite resin inlay in restoration of posterior ClassⅡcavity

    Institute of Scientific and Technical Information of China (English)

    董丽平; 孙璐; 杨洋; 陈丽娜; 尚丹丹

    2014-01-01

    Objective:To compare the clinical efficacy of CAD/CAM all-ceramic inlay and composite resin inlay in restoring ClassⅡcavity of posterior teeth. Methods:226 posterior teeth of ClassⅡcavity from 193 patients were recruited in our clinical trial. 101 teeth of the selected teeth were restored with CAD/CAM all-ceramic inlays, and the rest was restored by composite resin inlays. Prosthesis abrasion, prosthesis fracture, prosthesis off, marginal adapta-tion, edge coloring, and secondary caries of the two groups were evaluated during 6-month, 12-month and 18-month follow-up appointments, respectively. Results: There were significant differences in prosthesis abrasion and edge coloring between the two groups (P0.05). The success rate of CAD/CAM all-ceramic inlay is 96.84%, and the composite resin inlay is 81.05%. There was significant difference between the success rates (P<0.05). Conclusion:The efficacy of CAD/CAM all-ceramic inlay is better than that of composite resin inlay during the treatment of the posterior ClassⅡcavities.%目的:对比分析CAD/CAM全瓷嵌体与复合树脂嵌体修复后牙Ⅱ类洞的临床疗效。方法:选择在解放军总医院口腔内科就诊的后牙Ⅱ类洞患者193例(共226颗牙),根据患者意愿,其中101颗采用CAD/CAM全瓷嵌体修复,其余125颗采用复合树脂嵌体修复,分别在术后6个月、12个月、18个月进行随访,观察其修复体磨耗、折裂、脱落、边缘密合性、边缘着色及继发龋等情况。结果:2种嵌体在修复体磨耗及边缘着色的差异有统计学意义(P<0.05),在修复体折裂、修复体脱落、继发龋和边缘密合性的差异无统计学意义(P>0.05)。 CAD/CAM 全瓷嵌体的成功率为:96.84%,树脂嵌体的成功率为:81.05%,两组之间成功率的差异有统计学意义(P<0.05)。结论:在后牙Ⅱ类洞缺损的修复治疗中, CAD/CAM全瓷嵌体的效果优于复合树脂嵌体。

  17. Assembling consumption

    DEFF Research Database (Denmark)

    Assembling Consumption marks a definitive step in the institutionalisation of qualitative business research. By gathering leading scholars and educators who study markets, marketing and consumption through the lenses of philosophy, sociology and anthropology, this book clarifies and applies...... the investigative tools offered by assemblage theory, actor-network theory and non-representational theory. Clear theoretical explanation and methodological innovation, alongside empirical applications of these emerging frameworks will offer readers new and refreshing perspectives on consumer culture and market...... societies. This is an essential reading for both seasoned scholars and advanced students of markets, economies and social forms of consumption....

  18. Heater assembly

    International Nuclear Information System (INIS)

    An electrical resistance heater, installed in the H1 borehole, is used to thermally perturb the rock mass through a controlled heating and cooling cycle. Heater power levels are controlled by a Variac power transformer and are measured by wattmeters. Temperatures are measured by thermocouples on the borehole wall and on the heater assembly. Power and temperature values are recorded by the DAS described in Chapter 12. The heater assembly consists of a 3.55-m (11.6-ft) long by 20.3-cm (8-in.) O.D., Type 304 stainless steel pipe, containing a tubular hairpin heating element. The element has a heated length of 3 m (9.84 ft). The power rating of the element is 10 kW; however, we plan to operate the unit at a maximum power of only 3 kW. The heater is positioned with its midpoint directly below the axis of the P2 borehole, as shown in the borehole configuration diagram. This heater midpoint position corresponds to a distance of approximately 8.5 m (27.9 ft) from the H1 borehole collar. A schematic of the heater assembly in the borehole is shown. The distance from the borehole collar to the closest point on the assembly (the front end) is 6.5 m (21.3 ft). A high-temperature inflatable packer, used to seal the borehole for moisture collection, is positioned 50 cm (19.7 in.) ahead of the heater front end. The heater is supported and centralized within the borehole by two skids, fabricated from 25-mm (1-in.) O.D. stainless steel pipe. Thermocouples are installed at a number of locations in the H1 borehole. Four thermocouples that are attached to the heater skin monitor temperatures on the outer surface of the can, while three thermocouples that are held in place by rock sections monitor borehole wall temperatures beneath the heater. Temperatures are also monitored at the heater terminal and on the packer hardware

  19. General Assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : 1- Adoption de l’ordre du jour. 2- Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. 3- Présentation et approbation du rapport d’activités 2014. 4- Présentation et approbation du rapport financier 2014. 5- Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. 6- Programme 2015. 7- Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. 8- Pas de modifications aux Statuts de l'Association du personnel proposée. 9- Élections des membres de la Commission é...

  20. General assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. Présentation et approbation du rapport d’activités 2014. Présentation et approbation du rapport financier 2014. Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. Programme 2015. Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. Pas de modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commission électorale. &am...

  1. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    Mardi 5 avril à 11 h 00 BE Auditorium Meyrin (6-2-024) Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 mai 2015. Présentation et approbation du rapport d’activités 2015. Présentation et approbation du rapport financier 2015. Présentation et approbation du rapport des vérificateurs aux comptes pour 2015. Programme de travail 2016. Présentation et approbation du projet de budget 2016 Approbation du taux de cotisation pour 2017. Modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commissio...

  2. Fuel assembly

    International Nuclear Information System (INIS)

    Since the neutron flux distribution and the power distribution of a fuel assembly in which short fuel rods vary greatly in the vicinity of a boundary where the distribution of uranium amount is different, the reading value of local power range monitors, having the detectors positioned in the vicinity of the boundary is varied. Then in the present invention, the upper end of the effective axial length of fuel rod is so made as not approaching with the detection position of the local power range monitor in a reactor core. Further, the upper end of the effective axial length of fuel rods in a 4 x 4 fuel rod lattice positioned at the corner on the side of the local power range monitor is so made as not approaching the detection position of the local power range monitor. As a result, the change of the neutron flux distribution and power distribution in the vicinity of the position where the detector of the local power range monitor is situated can be extremely reduced. Accordingly, there is no scattering and fluctuation for the reading value by the local power range monitor, to improve the monitoring performance for thermal characteristics in the reactor core. (N.H.)

  3. Fuel assembly

    International Nuclear Information System (INIS)

    Purpose: To reconstruct a BWR type reactor into a high conversion reactor with no substantial changes for the reactor inner structure such as control rod structure. Constitution: The horizontal cross sectional shape of a channel box is reformed into a square configuration and the arrangement of fuel rods is formed as a trigonal lattice-like configuration. As a method of improving the conversion ratio, there is considered to use a dense lattice by narrowing the distance between fuel rods and trigonal lattice arrangement for fuel rod is advantageous therefor. A square shape cross sectional configuration having equal length both in the lateral and longitudinal directions is suitable for the channel box as a guide upon movement of the control rod. Fuel rods can be arranged with no loss by the trigonal lattice configuration, by which it is possible to improve the neutron moderation, increase the reactor core reactivity and conduct effective fuel combustion. In this way, it is possible to attain the object by inserting the follower portion of the control rod at the earier half and extracting the same at the latter half during the operation period in the reactor core comprising fuel assemblies suitable to a high conversion BWR type reactor having average conversion ratio of about 0.8. (Kamimura, M.)

  4. 粘接剂种类对全瓷桩核冠修复效果影响的三维有限元分析%Numerical analysis of the influence of agglomerant classes on stress distribution in all-ceramic post-core crown

    Institute of Scientific and Technical Information of China (English)

    李冰; 武秀萍; 马雅静; 邓菁菁; 武啸

    2015-01-01

    目的:分析不同粘接剂类型对前牙全瓷桩核冠系统在荷载作用下的应力分布情况的影响。方法:采用螺旋CT断层扫描技术和CAD建模软件相结合的方法,构建上颌中切牙的全瓷桩核冠三维有限元模型,加载牙合力,分析桩核冠经3种不同粘结剂(Panavia,3M RelyX Unicem,磷酸锌水门汀)粘固后,粘结剂层,核瓷层,饰瓷层的最大主应力分布。结果:在不同粘结材料的情况下,剩余牙本质的Von Mises应力和最大主应力分布情况基本一致。Von Mises应力主要集中在唇侧根颈1/3处,最大主应力(S1)主要集中在舌侧根颈1/3处。剩余牙本质的应力随着粘结剂弹性模量的增大而减小,粘结层的应力随着粘结剂弹性模量的增大而增大。结论:临床上在进行根管预备时,应尽量向近远中向扩展而保留更多的唇舌侧牙体组织,减小根颈1/3处根折发生的危险性。选择低弹性模量的粘结剂对保护桩粘结界面是有利的。%Objective:To provide the basis for the design of clinical treatment of all-ceramic post-core crown of ante-rior teeth prosthodontics,the influence of agglomerant classes on the stress distribution in all-ceramic crowns under load was studied numerically. Method:The finite element analysis (FEA) model of a standard all-ceramic post-core crown of the upper mandible central incisor was established using spiral CT and CAD software ,strength was loaded,and ANSYS software was used to analyze the stress values of the core layer、the veneer layer and the agglomerant layer on three variety type of agglomerant,including the Panavia,the 3M RelyX Unicem,and the the zinc phosphate cement. Result:According to distri-bution of the stress pattern,Von mises stress is located on the lip side of the 1/3 root and the maximal tensile stress on the lingual side of the 1/3 root.Under the load,the stress in residual dentine was shown to be decreasing

  5. Dynamically compacted all-ceramic lithium-ion batteries

    Science.gov (United States)

    Jak, Michiel J. G.; Ooms, Frans G. B.; Kelder, Erik M.; Legerstee, Waiter J.; Schoonman, Joop; Weisenburger, Alfons

    This paper deals with a cell design and a unique manufacturing process for all solid-state lithium-ion batteries. Detailed analyses of the manufacturing of the components for such a battery and the compaction of the green battery are presented. The electrodes were made of coatings of LiMn 2O 4 on metal foils. The electrolyte was a free-standing foil of the ceramic electrolyte Li-doped BPO 4 in a polymer matrix. The different layers were wound and compacted by using magnetic pulse compaction. Several characteristics of the compacted batteries are presented.

  6. Adaptation of all-ceramic fixed partial dentures

    Science.gov (United States)

    Borba, Márcia; Cesar, Paulo F.; Griggs, Jason A.; Della Bona, Álvaro

    2011-01-01

    Objectives To measure the marginal and internal fit of three-unit fixed partial dentures (FPDs) using the micro-CT technique, testing the null hypothesis that there is no difference in the adaptation between the ceramic systems studied. Methods Stainless steel models of prepared abutments were fabricated to design the FPDs. Ten FPDs were produced from each framework ceramic (YZ - Vita In-Ceram YZ and IZ - Vita In-Ceram Zirconia) using CEREC inLab according to the manufacturer instructions. All FPDs were veneered using the recommended porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross-sections images. Five measuring locations were used as follows: MG – marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. The horizontal marginal discrepancy (HMD) was evaluated in another set of images. Results were statistically analyzed using ANOVA and Tukey tests (α=0.05). Results The mean values for MG, CA, AW, OA and HMD were significantly different for all tested groups (p<0.05). IZ exhibited greater mean values than YZ for all measuring locations except for AW and AOT. OA showed the greatest mean gap values for both ceramic systems. MG and AW mean gap values were low for both systems. Significance The ceramic systems evaluated showed different levels of marginal and internal fit, rejecting the study hypothesis. Yet, both ceramic systems showed clinically acceptable marginal and internal fit. PMID:21920595

  7. Restoration of Endodontically Treated Molars Using All Ceramic Endocrowns

    OpenAIRE

    Roopak Bose Carlos; Mohan Thomas Nainan; Shamina Pradhan; Roshni Sharma; Shiny Benjamin; Rajani Rose

    2013-01-01

    Clinical success of endodontically treated posterior teeth is determined by the postendodontic restoration. Several options have been proposed to restore endodontically treated teeth. Endocrowns represent a conservative and esthetic restorative alternative to full coverage crowns. The preparation consists of a circular equigingival butt-joint margin and central retention cavity into the entire pulp chamber constructing both the crown and the core as a single unit. The case reports discussed h...

  8. 分光光度仪比较四种常用全瓷冠在三种基底表面的色度学参数%Spectrophotometric comparison of the colorimetric data of three dark color abutments overlaid by four types of all-ceramic crowns

    Institute of Scientific and Technical Information of China (English)

    陈奕帆; 李晓敏; 张琳; 王剑

    2015-01-01

    AIM:To evaluate the colorimetric parameter of 3 dark color abutments overlaid by 4 all-ceramic crowns using a digital dental spectrophotometer. METHODS: Abutments of Co-Cr alloys, Au-Pt alloys and ND8 (n=10) were made and were respectively tried in 4 groups of all-ceramic crowns (Procera aluminia, Procera zirconi-a, Lava zirconia and IPS E. max glass-ceramic lithium disilicate-reinforced monolithic crown) (n=10) respectively. The colorimetric data of the cervical, body and incisal sites of the samples were recorded and analyzed by a spectropho-tometer. The CIE L∗a∗b∗ values were measured again after veneer. The unglazed A2 ( Vitapan Classical) shade tab was used as the control. The L∗a∗b∗values and the color difference between the samples and control were calculated and statistically analyzed. RESULTS: There was significant difference of the lightness and saturation among 3 abut-ments. But after all-ceramic copings were tried in, the difference of the L∗values of the Pro-Alu copings and E. max HO copings decreased greatly. TheΔE value of the Pro-Alu copings was the smallest among all ceramic copings. And the ΔE value of the copings on the ND8 abutment was smallest among 3 abutments. After veneer, the consistency of the L∗ a∗b∗ values of all the copings increased, the IPS E. max HO crowns had very close L∗ values and the Pro-Zir crowns had similar a∗b∗ values in 3 groups of abutments. CONCLUSION:4 ceramic copings can promote the light-ness and hue of the dark abutments. All the copings on the ND8 abutment had small ΔE values. Veneering porcelain can increase the colorimetric match between the abutments to some extent. IPS E. max HO crowns have little difference of lightness and Procera zirconia has little difference of saturation among the abutmens.%目的::采用分光光度比色仪比较3种深色基底表面4种全瓷冠各部分的色度学参数。方法:制作钴铬合金、金铂合金及ND8色基牙预备体,分别戴

  9. 有限元法分析不同粘接剂对全瓷冠应力分布的影响%Effect of different bonding agents on the stress distribution of all-ceramic crown by three-dimension finite element analysis

    Institute of Scientific and Technical Information of China (English)

    李冰; 张晔; 武秀萍; 邓菁菁; 吴婷婷; 张并生

    2014-01-01

    目的:探讨不同种类粘接剂对双层结构的全瓷冠及粘接剂应力分布的影响,为临床修复设计提供依据。方法利用螺旋CT断层图像,构建双层结构的全瓷冠(核瓷层和饰瓷层)、粘接剂层、牙体组织、牙根、牙周膜和牙槽骨6部分的三维有限元模型,设计垂直集中载荷600N的加载方式,分析全瓷冠经3种不同粘接剂(Panavia,3M RelyX Unicem,3M RelyX Luting)粘固后,粘接剂层、核瓷层和饰瓷层的最大主应力分布。结果粘接层应力集中部位为近中颊侧肩台和腭侧面近牙合面部分。核瓷层应力主要集中在核瓷内部,饰瓷层应力主要集中在加载点附近。随着粘接材料弹性模量的增加,位于饰瓷层的最大主应力呈现出下降的趋势,而位于核瓷层和粘接层的最大主应力出现上升的趋势。结论全瓷冠在不同粘接材料粘固后受到力的作用时,最大主应力分布区域相对固定,但分布范围有向加载侧分布的趋势。在某些条件下,高弹性模量的粘接剂可能会降低全瓷冠崩瓷的发生,并在一定程度上降低核瓷层的抗折能力。%Objective To investigate the relationship between the bonding agents and the stress distribu-tion of all-ceramic crown and then provide the basis for clinical restoration design. Methods The tomography im-ages of spiral CT were used to construct the finite element analysis mode, which was composed of six parts:double layer structure of all-ceramic crown(include the core layer and the veneer layer), adhesive layer, tooth tissues, tooth root, periodontal ligament, and alveolar bone. The loading way was designed as follows:600N load was verti-cally concentrated, and ANSYS software was used to analyze the stress values of the core layer、the veneer layer and the adhesive layer with three bonding agents including the Panavia,the 3M RelyX Unicem and the3M RelyX Luting cement. Results The distribution

  10. Experiment and Application of Digital Control Pulse Tungsten Inert Gas Welding+Wire Filling Welding on Flexible Tubesheet and Tube of Sulfur Condenser%硫冷凝器柔性管板与换热管数控脉冲钨极氩弧焊填丝焊焊接工艺

    Institute of Scientific and Technical Information of China (English)

    王麒; 郭保平; 张鹰; 陈晶

    2015-01-01

    分析了大型硫冷凝器柔性管板与换热管的焊接接头结构特点,制定了3种焊接方案,详细介绍了按照焊接方案进行的焊接性试验,并进行了比较分析。选用效果较好的数控脉冲钨极氩弧焊填丝焊焊接工艺进行了焊接工艺评定,验证了拟定焊接工艺的正确性,并成功应用于产品生产中。%The welded joint of flexible tubesheet and heat exchanger tube of large sulfur con-denser are analyzed,3 welded solutions are developed,weldability test conducted by the 3 solu-tions is introduced in detail and compared,the weld procedure of best effect is selected to conduct welding procedure specification (WPS),the correctness of proposed WPS is verified and has been successfully used in production.

  11. Probe tip heating assembly

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Roger William; Oh, Yunje

    2016-10-25

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably received and clamped within the socket.

  12. Newnes electronics assembly handbook

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

  13. Inlet nozzle assembly

    Science.gov (United States)

    Christiansen, David W.; Karnesky, Richard A.; Precechtel, Donald R.; Smith, Bob G.; Knight, Ronald C.

    1987-01-01

    An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

  14. Tilt assembly for tracking solar collector assembly

    Science.gov (United States)

    Almy, Charles; Peurach, John; Sandler, Reuben

    2012-01-24

    A tilt assembly is used with a solar collector assembly of the type comprising a frame, supporting a solar collector, for movement about a tilt axis by pivoting a drive element between first and second orientations. The tilt assembly comprises a drive element coupler connected to the drive element and a driver, the driver comprising a drive frame, a drive arm and a drive arm driver. The drive arm is mounted to the drive frame for pivotal movement about a drive arm axis. Movement on the drive arm mimics movement of the drive element. Drive element couplers can extend in opposite directions from the outer portion of the drive arm, whereby the assembly can be used between adjacent solar collector assemblies in a row of solar collector assemblies.

  15. Assembly plans for ITER

    International Nuclear Information System (INIS)

    The assembly of ITER represents an extrapolation of a factor of two or more in size over existing large tokamaks. An assembly plan has been developed based on the ITER Outline Design. This plan was reviewed by technical experts and critical issues were identified. Alternate designs are being developed to address the most serious concerns and to minimize cost and assembly schedule. Because ITER has many characteristics of a full-scale nuclear reactor its assembly has challenges not faced previously by the fusion community. Careful assembly planning and well-designed tooling are required to insure success in the assembly of ITER

  16. Firearm trigger assembly

    Science.gov (United States)

    Crandall, David L.; Watson, Richard W.

    2010-02-16

    A firearm trigger assembly for use with a firearm includes a trigger mounted to a forestock of the firearm so that the trigger is movable between a rest position and a triggering position by a forwardly placed support hand of a user. An elongated trigger member operatively associated with the trigger operates a sear assembly of the firearm when the trigger is moved to the triggering position. An action release assembly operatively associated with the firearm trigger assembly and a movable assembly of the firearm prevents the trigger from being moved to the triggering position when the movable assembly is not in the locked position.

  17. Autonomous electrochromic assembly

    Science.gov (United States)

    Berland, Brian Spencer; Lanning, Bruce Roy; Stowell, Jr., Michael Wayne

    2015-03-10

    This disclosure describes system and methods for creating an autonomous electrochromic assembly, and systems and methods for use of the autonomous electrochromic assembly in combination with a window. Embodiments described herein include an electrochromic assembly that has an electrochromic device, an energy storage device, an energy collection device, and an electrochromic controller device. These devices may be combined into a unitary electrochromic insert assembly. The electrochromic assembly may have the capability of generating power sufficient to operate and control an electrochromic device. This control may occur through the application of a voltage to an electrochromic device to change its opacity state. The electrochromic assembly may be used in combination with a window.

  18. Three-year follow-up study of survival rates of IPS e.max Press all-ceramic crowns and three-unit fixed partial dentures%IPS e.max Press全瓷冠和三单位固定桥的3年存留率临床研究

    Institute of Scientific and Technical Information of China (English)

    李宁; 刘兵; 钟鸣

    2012-01-01

    Objective To evaluate the survival rate of IPS e. Max Press all - ceramic crowns and three - unit fixed partial dentures (FPDs) followed up for three years. Methods Forty -five patients with dental defects or single tooth loss were included in this study. A total of 46 crowns were placed in molar or premolar areas. 21 all - ceramic FPDs were placed in anterior and premolar areas. Follow - up examinations took place 6 , 12, 24, and 36 months after the placement. Results One crown and six FPD fractures were observed during the evaluation. The survival rate was 97.8% for crowns and 71.4% for FPDs . Framework fractures were recorded in FPD where the connector dimensions did not meet the manufacture's specifications. Conclusions Within the observation period of three years, IPS e. Max Press crowns exhibit satisfactory performance. Indications should be taken into serious consideration before the use of three - unit fixed partial dentures made from IPS e. Max Press.%目的 评估IPS e.max Press全瓷冠和三单位固定桥3年的存留率.方法 选择45例,男24例,女21例,全部病例均行IPS e.max Press全瓷冠或三单位固定桥修复,共67单位IPS e.max Press全瓷冠.其中46个单冠,21个三单位固定桥,单冠设计在双尖牙和第一磨牙,固定桥设计在前牙及双尖牙区.分别在修复体戴入后6、12、24、36个月对其是否发生脱落和折裂进行临床观察.结果 在修复后的3年观察期间,单冠有1例崩瓷,存留率为97.8%;固定桥6例失败,存留率为71.4%,固定桥失败原因为断裂,其中4例发生在连接体部分,1例基牙折断,1例为基牙松动.结论 在临床应用中,IPS e.max Press全瓷单冠的存留率很高,是一种美学和舒适度具佳的修复体,但在固定桥修复设计上应注意严格掌握临床适应证,避免修复失败.

  19. 数字化口腔修复(12)--CAD/CAM全瓷嵌体修复楔状缺损(附病例报告)%Digital restorative dentistry and prosthodontics (12)--Restoration of wedge-shaped defect by CAD/CAM all ceramic inlay (case report)

    Institute of Scientific and Technical Information of China (English)

    金地; 姚江武

    2016-01-01

    Objective:The clinical effects were observed on the restoration of wedge-shaped defect teeth by using two lithium silicate inlay by (computer aided design/computer aided manufacturing,CAD/CAM). Method:The clinical case was a patient who had a wedge-shaped defect teeth reached deep below free gingival margin, which was going to restore with all ceramic inlay by CAD/CAM. The clinical effect assessment was made after 6 and 12 months respectively, according to modified USPHS standard. Result:The results in each review stage showed that there were no undesirable effects such as fall off, fracture and cleav-age occurred on inlay. The clinical indexes had up to A class. Conclusion:Better clinical effect can be achieved in treating teeth with wedge-shaped defect using two lithium silicate inlay by CAD/CAM, but the long-term follow-up result still had to be fur-ther observed.%目的:观察计算机辅助设计和制作(CAD/CAM)二矽酸锂全瓷嵌体修复牙颈部缺损的临床疗效。方法:临床病例为1颗牙颈部继发龋坏深达龈下的患牙,采用CAD/CAM全瓷嵌体修复,按照改良的USPHS标准分别进行6个月和1年的临床疗效评价。结果:各个复查阶段:嵌体无脱落,折断、劈裂等不良现象,临床指标均达到A级指标。结论:CAD/CAM嵌体修复牙颈部楔状缺损是一种效果良好的修复方法。

  20. Efficacy and Long-term Prognosis of Zirconia All-ceramic Crown Plus Fiber Post for Repair of Ante-rior Teeth Complex Crown Root Fracture%氧化锆全瓷冠加纤维桩修复前牙复杂冠根折的疗效及远期预后分析

    Institute of Scientific and Technical Information of China (English)

    周凌燕; 毛艳; 苏宗佑; 陈俊文; 罗家威; 吕夏

    2016-01-01

    Objective To analyze the efficacy and long-term prognosis zirconia all-ceramic crown plus fiber post to repair anterior teeth complex crown root fracture.Methods From Feb.2008 to Jan.2010 in Affiliated Stomatology Hospital of Guangxi Medical University 110 patients for treatment of anterior teeth crown root fracture were included as research objects,and were divided into observation group and control group according to random number table method,55 cases each.The observation group adopted zirconia all-ceramic crown plus fiber post restoration treatment,an the control group adopted conventional orthodontic traction plus crown lengthening surgery for treatment.The tooth mobility,periodontal probing depth,gingival sulcus bleeding index of the two groups before and after treatment were compared,and 5 years of follow-up was done to compare the long-term prognosis.Results After treatment the tooth mobility,the sulcus bleeding index of the observation group were significantly lower than the control group [ ( 0.19 ±0.04 ) vs ( 0.40 ± 0.11),(0.78 ±0.16) vs (2.01 ±0.27),P <0.01],probing depth of the observation group was signifi-cantly higher than the control group[(5.99 ±0.14) mm vs (3.97 ±0.10) mm,P<0.01],the difference was statistically significant ( P <0.05 );the repair success rate of the observation group was significantly higher than the control group [92.73% (51/55) vs 54.55% (30/55)],the difference was statistically sig-nificant ( P <0.05 ) .Root fracture, secondary caries and periodontal disease incidence of the observation group were significantly lower than the control group [1.82%(1/55) vs 14.55%(8/55),1.82%(1/55) vs 9.09%(7/55),3.64%(2/55) vs 18.18%(10/55)],the differences were statistically significant(P<0.05).Conclusion Zirconia all-ceramic crowns plus fiber post has good clinical efficacy for anterior teeth complex crown root fracture,which can promote tooth mobility,probing depth,and improve sulcus bleeding index,with good long-term prognosis,thus is

  1. Polymer Directed Protein Assemblies

    NARCIS (Netherlands)

    van Rijn, Patrick

    2013-01-01

    Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e. g., virus particles. Viruses are a multi-protein assembly of which the morphology is

  2. Sensor mount assemblies and sensor assemblies

    Science.gov (United States)

    Miller, David H.

    2012-04-10

    Sensor mount assemblies and sensor assemblies are provided. In an embodiment, by way of example only, a sensor mount assembly includes a busbar, a main body, a backing surface, and a first finger. The busbar has a first end and a second end. The main body is overmolded onto the busbar. The backing surface extends radially outwardly relative to the main body. The first finger extends axially from the backing surface, and the first finger has a first end, a second end, and a tooth. The first end of the first finger is disposed on the backing surface, and the tooth is formed on the second end of the first finger.

  3. Effects of Over-burn on Corrosion Resistance of Hastelloy-C-276 Heat Exchanger Tube-sheet Welding%哈氏合金热交换器管板焊接过烧对耐腐蚀性能影响

    Institute of Scientific and Technical Information of China (English)

    魏化中; 熊仲营; 周超

    2011-01-01

    Hastelloy-C-276 is a kind of material with good corrosion resistance, which is gradually applied to the chemical field of key equipment since 1960s.Owing to unreasonable welding process, it is easy to produce an over-burn phenomenon existing in heat exchanger's tube and tube-sheet joints of Hastelloy-C-276 material.In order to find rule of over-burn on corrosion resistance of C-276 and avoid its endangerment, the normal welded tube specimens, over-burn specimens and over-burn repair specimens near welding line have been investigated by means of metallurgical structure comparison and intergranular corrosion test.%Hastelloy-C-276具有较好的抗腐蚀性能,自20世纪60年代以来逐步应用到化工领域的关键设备中.在管板与换热管连接接头的焊接过程中,由于某些原因容易出现连接接头过烧的现象.通过Hastelloy-C-276管板焊接中的正常焊接试件、过烧试件、过烧修补试件焊缝附近的金相组织比较及晶间腐蚀试验,对过烧对哈氏合金耐腐蚀性能的影响进行了简要分析.

  4. Soldering in electronics assembly

    CERN Document Server

    Judd, Mike

    2013-01-01

    Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem

  5. 饰瓷工艺对氧化锆陶瓷颜色和透光性的影响%Effect of veneering technologies on color and translucency of Y2O3 stabilized tetragonal zirconia polycrystals all-ceramic restorations

    Institute of Scientific and Technical Information of China (English)

    张蕾; 骆小平; 石玉娟

    2008-01-01

    Objective To compare color parameters and transmittance of Y2O3 stabilized tetragonal zirconia polycrystals(Y-TZP)all-ceramic restorations using different veneering technologies.Methods Fifteen disc specimens with 10 mm in diameter and(0.50±0.01)mm in thickness were fabricated of IPS e.max ZirCAD core material,and ZL1 IPS e.max ZirLiner was layered in 0.10 mm thickness.The specimens were divided into three groups randomly(n=5 per group).Group ZP was veneered 0.60 mm by heat-pressing;group ZC was veneered 0.60 mm by layering;group ZPC was veneered 0.30 mm by heatpressing and then 0.30 mm by layering.Color parameters L*,a*,b*and transmittance of zirconia specimens were measured before and after veneering with ShadeEye NCC dental chromameter and spectrophotometer.Color saturation C*ab and color difference ΔE were calculated in the following formulae:C*ab=[(a*)2+(b*)2]1/2,ΔE=[(△L*)2+(△a+)2+(△b*)2]1/2.One-way analysis of variance and Turkey's multiple comparison test were used to analyze data(α=0.05)by SPSS 10.0 statistic software.Color parameters of A2 shade tabs were measured,and color differences between each group and tab were calculated.Results As to ZP、ZPC、ZC groups,the value of a*increased(-1.35±0.07,-0.64±0.06,-0.36±0.05)(P<0.05),the value of b*decreased(27.01±0.07,25.48±0.11,23.28±0.25)(P<0.05),and the value of C*ab decreased(27.04±0.08,25.49±0.11,23.28±0.25)(P<0.05).L*and transmittance were maximum in ZP group(87.53±0.48,1.64±0.03)and minimum in ZPC group(82.14±0.18,1.47±0.01)(P<0.05).Compared with standard A2 shade tab,the color difference of ZC group was minimum(ΔE=1.04),and the color difference of ZP group was maximum (ΔE=4.86).Conclusions Y-TZP all-ceramic restoration veneered by heat-pressing was the most transparent and lightest;while veneered by both heat-pressing and layering,the restoration was worst in translucency and the least light.The color of zirconia all-ceramic restoration veneered by layering was the most

  6. Evaluation on effect of glass fiber pile combined with all-ceramic crown in restoration for defect of anterior teeth%玻璃纤维桩联合全瓷冠修复前牙牙体缺损的效果评价

    Institute of Scientific and Technical Information of China (English)

    邹红

    2013-01-01

    目的 探讨玻璃纤维桩联合全瓷冠修复前牙牙体缺损的临床疗效.方法 将我院收治的因前牙缺损行美容修复的患者52 例(136 颗牙)随机分为治疗组(26 例70 颗)和对照组(26 例66 颗)两组,在根管治疗后分别采用玻璃纤维桩全瓷冠修复和铸造桩加钴铬烤瓷冠修复.观察两组修复成功率,对修复前后局部龈沟液(GCF)和龈沟液中碱性磷酸酶(ALP)水平进行检测,并对患者随访1 年,评估其远期疗效.结果 治疗组和对照组的修复成功率分别为95.7%、90.0% (P>0.05);治疗后4 周、12 周,对照组局部GCF、ALP水平均较治疗前显著升高,且显著高于同期治疗组的水平(P0.05);治疗1 年后,治疗组的修复体完整度、边缘适合度、颜色匹配均显著优于对照组(P0.05. After treatment for 4 weeks and 12 weeks, the levels of GCF and ALP was significantly increased in the control group compared with before treatment, while there was no significant difference on these indicators in the treatment group before and after treatment (t=0.65, 0.74, P>0.05). The levels after treatment were significantly higher in the control group than the treatment group (P<0.05). After restoration for 1 year, the integrity, marginal adaptation, and color match in the treatment group were all significantly better than those in the control group (P< 0.05). Conclusion Glass fiber pile combined with all-ceramic crown has relatively small stimulation on periodonti-um, with good aesthetic and biological characteristics, which can be used as an ideal restoration method for defect of anterior teeth.

  7. Target Assembly Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Target Assembly Facility integrates new armor concepts into actual armored vehicles. Featuring the capability ofmachining and cutting radioactive materials, it...

  8. Assembly of ISX

    Energy Technology Data Exchange (ETDEWEB)

    Durfee, N.W.

    1977-01-01

    The Impurity Study Experiment, a moderate size tokamak, was recently assembled at ORNL. Demountable toroidal field coils allowed for the assembly of major components at remote locations and rapid installation into ISX. A discharge cleaning plasma was generated in ISX six weeks after the arrival of the final toroidal field coil. A chronological summary of the assembly is presented, emphasizing features designed to aid in assembly and maintenance. A cross-section of the machine showing the major mechanical components to be discussed is given.

  9. Composite turbine bucket assembly

    Science.gov (United States)

    Liotta, Gary Charles; Garcia-Crespo, Andres

    2014-05-20

    A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to be attached to the turbine rotor or disk.

  10. Extending reference assembly models

    DEFF Research Database (Denmark)

    Church, Deanna M.; Schneider, Valerie A.; Steinberg, Karyn Meltz;

    2015-01-01

    The human genome reference assembly is crucial for aligning and analyzing sequence data, and for genome annotation, among other roles. However, the models and analysis assumptions that underlie the current assembly need revising to fully represent human sequence diversity. Improved analysis tools...

  11. Assembly of primary cilia

    DEFF Research Database (Denmark)

    Pedersen, Lotte B; Veland, Iben R; Schrøder, Jacob M;

    2008-01-01

    in primary cilia assembly or function have been associated with a panoply of disorders and diseases, including polycystic kidney disease, left-right asymmetry defects, hydrocephalus, and Bardet Biedl Syndrome. Here we provide an up-to-date review focused on the molecular mechanisms involved in the assembly...

  12. Perspective: Geometrically frustrated assemblies

    Science.gov (United States)

    Grason, Gregory M.

    2016-09-01

    This perspective will overview an emerging paradigm for self-organized soft materials, geometrically frustrated assemblies, where interactions between self-assembling elements (e.g., particles, macromolecules, proteins) favor local packing motifs that are incompatible with uniform global order in the assembly. This classification applies to a broad range of material assemblies including self-twisting protein filament bundles, amyloid fibers, chiral smectics and membranes, particle-coated droplets, curved protein shells, and phase-separated lipid vesicles. In assemblies, geometric frustration leads to a host of anomalous structural and thermodynamic properties, including heterogeneous and internally stressed equilibrium structures, self-limiting assembly, and topological defects in the equilibrium assembly structures. The purpose of this perspective is to (1) highlight the unifying principles and consequences of geometric frustration in soft matter assemblies; (2) classify the known distinct modes of frustration and review corresponding experimental examples; and (3) describe outstanding questions not yet addressed about the unique properties and behaviors of this broad class of systems.

  13. Fuel Assembly Damping Summary

    International Nuclear Information System (INIS)

    This paper summary the fuel assembly damping data in air/in still water/under flow, released from foreign fuel vendors, compared our data with the published data. Some technical issues in fuel assembly damping measurement testing are also briefly discussed. Understanding of each fuel assembly damping mechanisms according to the surrounding medium and flow velocity can support the fuel design improvement in fuel assembly dynamics and structural integrity aspect. Because the upgraded requirements of the newly-developed advanced reactor system will demands to minimize fuel design margin in integrity evaluation, reduction in conservatism of fuel assembly damping can contribute to alleviate the fuel design margin for sure. Damping is an energy dissipation mechanism in a vibrating mechanical structure and prevents a resonant structure from having infinite vibration amplitudes. The sources of fuel assembly damping are various from support friction to flow contribution, and it can be increased by the viscosity or drag of surrounding fluid medium or the average velocity of water flowing. Fuel licensing requires fuel design evaluation in transient or accidental condition. Dynamic response analysis of fuel assembly is to show fuel integrity and requires information on assembly-wise damping in dry condition and under wet or water flowing condition. However, damping measurement test for the full-scale fuel assembly prototype is not easy to carry out because of the scale (fuel prototype, test facility), unsteadiness of test data (scattering, random sampling and processing), instrumentation under water flowing (water-proof response measurement), and noise. LWR fuel technology division in KAERI is preparing the infra structure for damping measurement test of full-scale fuel assembly, to support fuel industries and related research activities. Here is a preliminary summary of fuel assembly damping, published in the literature. Some technical issues in fuel assembly damping

  14. Self-assembled nanostructures

    CERN Document Server

    Zhang, Jin Z; Liu, Jun; Chen, Shaowei; Liu, Gang-yu

    2003-01-01

    Nanostructures refer to materials that have relevant dimensions on the nanometer length scales and reside in the mesoscopic regime between isolated atoms and molecules in bulk matter. These materials have unique physical properties that are distinctly different from bulk materials. Self-Assembled Nanostructures provides systematic coverage of basic nanomaterials science including materials assembly and synthesis, characterization, and application. Suitable for both beginners and experts, it balances the chemistry aspects of nanomaterials with physical principles. It also highlights nanomaterial-based architectures including assembled or self-assembled systems. Filled with in-depth discussion of important applications of nano-architectures as well as potential applications ranging from physical to chemical and biological systems, Self-Assembled Nanostructures is the essential reference or text for scientists involved with nanostructures.

  15. Constrained space camera assembly

    Science.gov (United States)

    Heckendorn, Frank M.; Anderson, Erin K.; Robinson, Casandra W.; Haynes, Harriet B.

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  16. Clinical evaluation of zirconia all-ceramic crowns and bridges designed and manufactured by computer aided design and computer aided manufacture system%计算机辅助设计与制作氧化锆全瓷冠桥的临床应用

    Institute of Scientific and Technical Information of China (English)

    柳正明; 骆小平; 俞青; 丁晨

    2011-01-01

    that zirconia frameworks demonstrated sufficient stability for all-ceramic fixed partial denture using individual-design processing technology.

  17. Effects of try-in paste and luting agent on the resultant color of all-ceramic veneers%试色糊剂和黏结剂对瓷贴面修复体颜色影响的一致性研究

    Institute of Scientific and Technical Information of China (English)

    徐镔亭; 李清; 李蓉; 王贻宁

    2011-01-01

    Objective The purposes of this study was to investigate the effects of luting agents on the resultant color of IPS e.max all-ceramic veneer restorations, and to evaluate the similarity of try-in pastes and the corresponding luting agents on the final color.Methods Disc-shaped ceramic specimens were fabricated and seated on four shades of resin specimens to mimic the complex of ceramic veneer laying on tooth substrates.Try-in pastes and luting agents(Shades of TR, B0.5, A1, A3, WO) were applied into the inter-layer of ceramic and resin specimens,respectively.The color of the combinations was measured using a spectrophotometer and subsequently converted to CIE L*a*b* values Color changes after luting agent applied, and between try-in paste and corresponding luting agent were calculated and registered as △Eremin and △Epatke-remin Results △Emin value of A2, A3 backgrounds was more than 1.0.△Eremin value of A4, A5 backgrounds was less than 1.0.The △Epatke-remin value of A3 backgrounds was more than 1.0, whereas, A2 was less than 1.0(except for shade WO).The △Epatke-remin value of shade WO was significantly different from other shades of luting agents.Conclusion The color of ceramic veneer restorations were affected by luting agents with A2, and A3 background colors.The agreement of the try-in paste and the corresponding luting agent was excellent for A2 background(except for WO).%目的 观察试色糊剂和相应色号树脂黏结剂对IPS e.max瓷贴面修复体最终颜色的影响及影响的一致性.方法 叠加IPS e.max热压铸瓷片和复合树脂块模拟瓷贴面覆盖预备后的基牙.在瓷试样和树脂试样之间分别加入试色糊剂和树脂黏结剂(TR、B0.5、A1、A3和WO色)形成试样复合体.使用分光光谱仪测量复合体颜色,并分别用△Ereain代表使用黏结剂前后的色差和△Epaste-reain代表使用试色糊剂与使用黏结剂的色差.结果 基底为A2、A3色时,△Ereain值大于1.0,A4、A5

  18. Effect of the veneer porcelain thickness on the color and transmissivity of IPS e.max all-ceramic restoration%饰面瓷厚度对IPS e.max全瓷修复体颜色及透射率的影响

    Institute of Scientific and Technical Information of China (English)

    李莉; 刘晓艳

    2014-01-01

    目的:探讨不同饰面瓷厚度对IPS e.max全瓷修复体颜色及透射率的影响,发现规律,为完善全瓷修复体制作工艺及临床实践提供参考依据。方法将IPS e.max铸瓷材料制作成核瓷厚度为0.8 mm、牙本质瓷厚度为1.2 mm的总厚度为2.0 mm、直径为15 mm的圆盘状试件。试件表面每次均匀磨去0.2 mm,至其厚度为1.4 mm。每一厚度均测量其L*a*b*颜色参数及透射率,并对结果进行统计学分析。结果随着饰面瓷厚度的增加,IPS e.max全瓷修复体的L*值呈降低趋势,a*值和b*值无明显变化趋势;ΔE值呈降低趋势,且各厚度组间色差ΔE均大于1.5;TP值逐渐降低,CR值逐渐增加,可见光积分透射率逐渐降低。结论随着饰面瓷厚度的增加,IPS e.max全瓷修复体的色调无明显变化,明度、半透性和可见光积分透射率逐渐降低,对背景颜色的遮盖能力逐渐增强。%Objective Study the influence of different veneer porcelain thickness to the color and transmissivity of IPS e.max all-ceramic restoration, discover the rule, in order to get vivid color and ideal restoration effect. Methods Make IPS e.max into discal specimens with 15mm in diameter and 2.0mm thick including 0.8mm thick nuclear porcelain and 1.2mm dentin porcelain. And then they are grinded 0.2 mm each time, to the thickness of 1.4 mm. Measure the L*a*b* parameters and transmissivity of each thickness,and proceed statistical analysis. Results With dentin porcelain thickness increasing, the L*values reduce, the a*values and b*values of IPS e.max have no obvious change trend;ΔE and TP values gradually reduce, while CR values increase, the transmissivity gradually reduce. Conclusion With the dentin porcelain thickness increasing,value, translucency and transmissivities gradually reduce while hue has no obvious change.

  19. DC source assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Jeremy B; Newson, Steve

    2013-02-26

    Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

  20. Steam separator latch assembly

    Science.gov (United States)

    Challberg, Roy C.; Kobsa, Irvin R.

    1994-01-01

    A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof.

  1. Nuclear reactor spacer assembly

    International Nuclear Information System (INIS)

    A fuel assembly for a nuclear reactor is disclosed wherein the fuel element receiving and supporting grid is comprised of a first metal, the guide tubes which pass through the grid assembly are comprised of a second metal and the grid is supported on the guide tubes by means of expanded sleeves located intermediate the grid and guide tubes. The fuel assembly is fabricated by inserting the sleeves, of initial outer diameter commensurate with the guide tube outer diameters, through the holes in the grid assembly provided for the guide tubes and thereafter expanding the sleeves radially outwardly along their entire length such that the guide tubes can subsequently be passed through the sleeves. The step of radial expansion, as a result of windows provided in the sleeves having dimensions commensurate with the geometry of the grid, mechanically captures the grid and simultaneously preloads the sleeve against the grid whereby relative motion between the grid and guide tube will be precluded

  2. Spent fuel assembly hardware

    International Nuclear Information System (INIS)

    When spent nuclear fuel is disposed of in a repository, the waste package will include the spent fuel assembly hardware, the structural portion of the fuel assembly, and the fuel pins. The spent fuel assembly hardware is the subject of this paper. The basic constituent parts of the fuel assembly will be described with particular attention on the materials used in their construction. The results of laboratory analyses performed to determine radionuclide inventories and trace impurities also will be described. Much of this work has been incorporated into a US Department of Energy (DOE) database maintained by Oak Ridge National Laboratory (ORNL). This database is documented in DOE/RW-0184 and can be obtained from Karl Notz at ORNL. The database provides a single source for information regarding wastes that may be sent to the repository

  3. High speed door assembly

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.

    1991-12-31

    This invention is comprised of a high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  4. Assemblies of gold icosahedra

    OpenAIRE

    Bilalbegovic, G.

    2004-01-01

    Low-dimensional free-standing aggregates of bare gold clusters are studied by the molecular dynamics simulation. Icosahedra of 55 and 147 atoms are equilibrated at T=300 K. Then, their one- and two-dimensional assemblies are investigated. It is found that icosahedra do not coalescence into large drops, but stable amorphous nanostructures are formed: nanowires for one-dimensional and nanofilms for two-dimensional assemblies. The high-temperature stability of these nanostructures is also invest...

  5. Human Assisted Assembly Processes

    Energy Technology Data Exchange (ETDEWEB)

    CALTON,TERRI L.; PETERS,RALPH R.

    2000-01-01

    Automatic assembly sequencing and visualization tools are valuable in determining the best assembly sequences, but without Human Factors and Figure Models (HFFMs) it is difficult to evaluate or visualize human interaction. In industry, accelerating technological advances and shorter market windows have forced companies to turn to an agile manufacturing paradigm. This trend has promoted computerized automation of product design and manufacturing processes, such as automated assembly planning. However, all automated assembly planning software tools assume that the individual components fly into their assembled configuration and generate what appear to be a perfectly valid operations, but in reality the operations cannot physically be carried out by a human. Similarly, human figure modeling algorithms may indicate that assembly operations are not feasible and consequently force design modifications; however, if they had the capability to quickly generate alternative assembly sequences, they might have identified a feasible solution. To solve this problem HFFMs must be integrated with automated assembly planning to allow engineers to verify that assembly operations are possible and to see ways to make the designs even better. Factories will very likely put humans and robots together in cooperative environments to meet the demands for customized products, for purposes including robotic and automated assembly. For robots to work harmoniously within an integrated environment with humans the robots must have cooperative operational skills. For example, in a human only environment, humans may tolerate collisions with one another if they did not cause much pain. This level of tolerance may or may not apply to robot-human environments. Humans expect that robots will be able to operate and navigate in their environments without collisions or interference. The ability to accomplish this is linked to the sensing capabilities available. Current work in the field of cooperative

  6. 核瓷表面处理对二硅酸锂、氧化锆双层瓷失效行为的影响%Effect of core ceramic surface treatment on the failure behavior of two bilayered all-ceramic structures

    Institute of Scientific and Technical Information of China (English)

    唐天宇; 王晓东; 简裕涛; 赵克

    2015-01-01

    目的 探讨核瓷表面处理对二硅酸锂、氧化锆双层瓷失效行为的影响,为其临床加工制作提供依据.方法 二硅酸锂和氧化锆核瓷试件均按随机数字表分为4个组(每组样本量为12),碳化硅砂纸逐级打磨至1 000目(A组)、600目(B组)、320目(C组)或行喷砂后不打磨(D组)处理并测定表面粗糙度.两种核瓷烧结饰瓷后测定断裂强度并计算韦布尔模数(m值),分析失效模式.结果 对于二硅酸锂双层瓷,4组断裂强度差异无统计学意义(F=0.406,P=0.750),4组m值95%置信区间重叠,各组均以饰瓷内聚失效为主.对于氧化锆双层瓷,D组断裂强度[(640±95) MPa]显著高于其他3组[A、B、C组分别为(541±75)、(533±73)、(529±78) MPa] (P<0.05),4组m值95%置信区间重叠,各组均以饰瓷剥脱失效为主.结论 二硅酸锂核瓷的表面处理对双层瓷结构失效行为无显著影响;喷砂有助于提高氧化锆双层瓷结构的断裂强度,减少界面处饰-核瓷的分层.%Objective To evaluate the effect of core ceramic surface treatment on the failure behaviors of two bilayered all-ceramic structures.Methods Lithium disilicate glass-ceramic(LDG,IPS e.max Press) and Zirconia(Cercon) specimens were divided into 4 groups(n=12) according to the following surface treatment methods:ground successively to 1 000(group A),600(group B) and 320(group C)grit silicon carbide(SiC) papers and sandblasted with 110 μm aluminum oxide particle(group D,as control).Surface roughness was measured using a profilometer.After veneer sintering,the flexural strength σ was measured with biaxial flexure test and the reliability of strength was analyzed with Weibull distribution.Failure modes and fractographic patterns were analyzed by optical stereo and scanning electron microscopy (SEM).Results For LDG,no significant difference was found for the flexural strength values among groups (F=0.406,P=0.750).No significant difference was found in Weibull modulus

  7. The application of all ceramic restoration to correct anterior mild malocclusion in adult and its clinical aesthetic restoration%全瓷修复技术在矫正成人轻度前牙错畸形及临床美学修复中的应用

    Institute of Scientific and Technical Information of China (English)

    邱伟江; 郑学汜; 刘智飞; 孟秋菊

    2014-01-01

    . Experimental group were treated by repairing the all-ceramic restoration, control group were treated by nickel-chromium alloy PFM crown restoration. Compared two groups of 6 months after treatment in patients with visual analogue scale (VAS) satisfaction score, before and 6, 12 months after treatment gingival index and 6 months after treatment restoration the revised standard rating of the American Public Health Association (USPHS score). Result After treatment in experimental group patients with the cut end of the trial defect, tooth surface defect and deformity of small teeth, tooth clearance, tooth staining and total satisfaction VAS scores were signiifcantly higher than that of control group (P<0.05). 6 months after treatment in both groups of GI were signiifcantly higher than before treatment, 12 months treatment after of GI were signiifcantly less than 6 months after treatment (P < 0.05);experimeutal group 6 months and 12 months after treatment of GI were signiifcantly lower than control group (P<0.01). Experimental group after treatment for 6 months ago dental restoration edge coloring and ift score was signiifcantly higher than control group (P < 0.05). Conclusion The whole porcelain restoration technique before orthodontic adult mild tooth occlusal wrong deformity curative effect is distinct, better than that of nickel-chromium alloy PFM crowns, suitable for mild crowded displacement before, bad bite or tooth discoloration of mild deformity, worthy of clinical application.

  8. An update on complex I assembly: the assembly of players

    OpenAIRE

    Vartak, Rasika S.; Semwal, Manpreet Kaur; Bai, Yidong

    2014-01-01

    Defects in Complex I assembly is one of the emerging underlying causes of severe mitochondrial disorders. The assembly of Complex I has been difficult to understand due to its large size, dual genetic control and the number of proteins involved. Mutations in Complex I subunits as well as assembly factors have been reported to hinder its assembly and give rise to a range of mitochondria disorders. In this review, we summarize the recent progress made in understanding the Complex I assembly pat...

  9. Photovoltaic self-assembly.

    Energy Technology Data Exchange (ETDEWEB)

    Lavin, Judith; Kemp, Richard Alan; Stewart, Constantine A.

    2010-10-01

    This late-start LDRD was focused on the application of chemical principles of self-assembly on the ordering and placement of photovoltaic cells in a module. The drive for this chemical-based self-assembly stems from the escalating prices in the 'pick-and-place' technology currently used in the MEMS industries as the size of chips decreases. The chemical self-assembly principles are well-known on a molecular scale in other material science systems but to date had not been applied to the assembly of cells in a photovoltaic array or module. We explored several types of chemical-based self-assembly techniques, including gold-thiol interactions, liquid polymer binding, and hydrophobic-hydrophilic interactions designed to array both Si and GaAs PV chips onto a substrate. Additional research was focused on the modification of PV cells in an effort to gain control over the facial directionality of the cells in a solvent-based environment. Despite being a small footprint research project worked on for only a short time, the technical results and scientific accomplishments were significant and could prove to be enabling technology in the disruptive advancement of the microelectronic photovoltaics industry.

  10. Modular Fixture Assembly Model for Virtual Assembly Design

    Institute of Scientific and Technical Information of China (English)

    PENG Gao-liang; CHEN Guang-feng; LIU Xin-hua

    2009-01-01

    To support modular fixture assembly design in virtual environment, a multi-view based modular fixture virtual assembly model is proposed. Instead of squeezing all assembly related information into a single model, three complementary views of assembly model, element information, function and structure, and assembly relationship are proposed to be used. The first view contains the detailed element information, while the other two explicitly capture the hierarchical function relationships and mating relationships respectively. These views are complementary in the sense that each view only contains a specific aspect of assembly related information while together they include required assembly related information. The proposed assembly model is specialized to accommodate the features of modular fixture virtual assembly design and applied in our developed prototype system.

  11. Power module assembly

    Science.gov (United States)

    Campbell, Jeremy B.; Newson, Steve

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  12. Blade attachment assembly

    Science.gov (United States)

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  13. In vitro kinetochore assembly

    Science.gov (United States)

    Miell, Matthew D D; Straight, Aaron F

    2016-01-01

    The kinetochore is the primary site of interaction between chromosomes and microtubules of the mitotic spindle during chromosome segregation. The kinetochore is a complex of more than 100 proteins that transiently assemble during mitosis at a single defined region on each chromosome, known as the centromere. Kinetochore assembly and activity must be tightly regulated to ensure proper microtubule interaction and faithful chromosome segregation because perturbation of kinetochores often results in aneuploidy and cell lethality. As such, cell free and reconstituted systems to analyze kinetochore formation and function are invaluable in probing the biochemical activities of kinetochores. In vitro approaches to studying kinetochores have enabled the manipulation of kinetochore protein structure, function, interactions and regulation that are not possible in cells. Here we outline a cell-free approach for the assembly of centromeres and recruitment of functional kinetochores that enables their manipulation and analysis. PMID:27193846

  14. Assembling Sustainable Territories

    DEFF Research Database (Denmark)

    Vandergeest, Peter; Ponte, Stefano; Bush, Simon

    2015-01-01

    The authors show how certification assembles ‘sustainable’ territories through a complex layering of regulatory authority in which both government and nongovernment entities claim rule-making authority, sometimes working together, sometimes in parallel, sometimes competitively. It is argued...... that territorialisation is accomplished not just through (re)defining bounded space, but more broadly through the assembling of four elements: space, subjects, objects, and expertise. Four case studies of sustainability certification in seafood are analyzed to show that ‘green gabbing’ is not necessarily the central...... dynamic in assembling sustainable territories, and that certification always involves state agencies in determining how the key elements that comprise it are defined. Whereas some state agencies have been suspicious of sustainability certification, others have embraced it or even used it to extend...

  15. Integrated magnetic transformer assembly

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to an integrated magnetics transformer assembly comprising a first magnetically permeable core forming a first substantially closed magnetic flux path and a second magnetically permeable core forming a second substantially closed magnetic flux path. A first input...... inductor winding is wound around a first predetermined segment of the first magnetically permeable core and a second input inductor winding is wound around a first predetermined segment of the second magnetically permeable core. The integrated magnetics transformer assembly further comprises a first output......-winding of the first output inductor winding and the first half-winding of the second output inductor winding are configured to produce aligned, i.e. in the same direction, magnetic fluxes through the first substantially closed magnetic flux path. The integrated magnetics transformer assembly is well- suited for use...

  16. Transfer of fuel assemblies

    International Nuclear Information System (INIS)

    Fuel assemblies of a nuclear reactor are transferred during fueling or refueling or the like by a crane. The work-engaging fixture of the crane picks up an assembly, removes it from this slot, transfers it to the deposit site and deposits it in its slot at the deposit site. The control for the crane includes a strain gauge connected to the crane line which raises and lowers the load. The strain gauge senses the load on the crane. The signal from the strain gauge is compared with setpoints; a high-level setpoint, a low-level setpoint and a slack-line setpoint. If the strain gauge signal exceeds the high-level setpoint, the line drive is disabled. This event may occur during raising of a fuel assembly which encounters resistance. The high-level setpoint may be overridden under proper precautions. The line drive is also disabled if the strain gauge signal is less than the low-level setpoint. This event occurs when a fuel assembly being deposited contacts the bottom of its slot or an obstruction in, or at the entry to the slot. To preclude lateral movement and possible damage to a fuel assembly suspended from the crane line, the traverse drive of the crane is disabled once the strain-gauge exceets the lov-level setpoint. The traverse drive can only be enabled after the strain-gauge signal is less than the slack-line set-point. This occurs when the lines has been set in slack-line setting. When the line is tensioned after slack-li ne setting, the traverse drive remains enabled only if the line has been disconnected from the fuel assembly

  17. Low inductance connector assembly

    Science.gov (United States)

    Holbrook, Meghan Ann; Carlson, Douglas S

    2013-07-09

    A busbar connector assembly for coupling first and second terminals on a two-terminal device to first and second contacts on a power module is provided. The first terminal resides proximate the first contact and the second terminal resides proximate the second contact. The assembly comprises a first bridge having a first end configured to be electrically coupled to the first terminal, and a second end configured to be electrically coupled to the second contact, and a second bridge substantially overlapping the first bridge and having a first end electrically coupled to the first contact, and a second end electrically coupled to the second terminal.

  18. Fire resistant PV shingle assembly

    Science.gov (United States)

    Lenox, Carl J.

    2012-10-02

    A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

  19. An Interactive Assembly Process Planner

    Institute of Scientific and Technical Information of China (English)

    廖华飞; 张林鍹; 肖田元; 曾理; 古月

    2004-01-01

    This paper describes the implementation and performance of the virtual assembly support system (VASS), a new system that can provide designers and assembly process engineers with a simulation and visualization environment where they can evaluate the assemblability/disassemblability of products, and thereby use a computer to intuitively create assembly plans and interactively generate assembly process charts. Subassembly planning and assembly priority reasoning techniques were utilized to find heuristic information to improve the efficiency of assembly process planning. Tool planning was implemented to consider tool requirements in the product design stage. New methods were developed to reduce the computation amount involved in interference checking. As an important feature of the VASS, human interaction was integrated into the whole process of assembly process planning, extending the power of computer reasoning by including human expertise, resulting in better assembly plans and better designs.

  20. A Method for Designing Assembly Tolerance Networks of Mechanical Assemblies

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2012-01-01

    Full Text Available When designing mechanical assemblies, assembly tolerance design is an important issue which must be seriously considered by designers. Assembly tolerances reflect functional requirements of assembling, which can be used to control assembling qualities and production costs. This paper proposes a new method for designing assembly tolerance networks of mechanical assemblies. The method establishes the assembly structure tree model of an assembly based on its product structure tree model. On this basis, assembly information model and assembly relation model are set up based on polychromatic sets (PS theory. According to the two models, the systems of location relation equations and interference relation equations are established. Then, using methods of topologically related surfaces (TTRS theory and variational geometric constraints (VGC theory, three VGC reasoning matrices are constructed. According to corresponding relations between VGCs and assembly tolerance types, the reasoning matrices of tolerance types are also established by using contour matrices of PS. Finally, an exemplary product is used to construct its assembly tolerance networks and meanwhile to verify the feasibility and effectiveness of the proposed method.

  1. Radiographic testing of tube-to-tubesheet of heatexchanger

    International Nuclear Information System (INIS)

    Most of the heat exchangers used for thermal and nuclear power plants are of shell and tube type, and when tubes and tube plates are welded, high reliability is required for the welded parts. As the intermediate heat exchangers for high temperature liquid sodium of FBRs, the similar construction is considered, therefore, the inspection of high accuracy is indispensable. There are various welded joint types for tubes and tube plates. Toshiba Corp. has developed and put in practical use the inspection techniques for the welded joints of tubes and tube plates using the small focus x-ray apparatuses of rod anode type, and very high reliability was able to be obtained. By applying these techniques, the skill of welders can be tested and certified, and the quality of welded parts can be heightened. With the small focus x-ray apparatuses, the energy can be changed by the tube voltage, high sharpness and contrast can be obtained, and inspection can be carried out in a short time. The principle, specification, targets and test results of these apparatuses are described. The radiography of the butt-welded joints, inserted type joints and other types of tubes and tube plates is explained. The procedure of radiography is shown. (Kako, I.)

  2. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2011-01-01

    Tuesday 12 April at 14.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 20 April 2010 Presentation and approval of the Activity Report 2010 Presentation and approval of the Financial Report 2010 Presentation and approval of the Auditors Report 2010 Programme for 2011 Presentation et and approval of the draft budget and subscription rate 2012 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly ma...

  3. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2011-01-01

    Tuesday 12 April at 14.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 20 April 2010 Presentation and approval of the Activity Report 2010 Presentation and approval of the Financial Report 2010 Presentation and approval of the Auditors Report 2010 Programme for 2011 Presentation and approval of the draft budget and subscription rate 2012 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly may r...

  4. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2010-01-01

    Tuesday 20 April at 10.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 12 May 2009 Presentation and approval of the Activity Report 2009 Presentation and approval of the Financial Report 2009 Presentation and approval of the Auditors Report 2009 Programme for 2010 Presentation et and approval of the draft budget and subscription rate 2010 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly may require t...

  5. Rotary shaft sealing assembly

    Science.gov (United States)

    Dietle, Lannie L.; Schroeder, John E.; Kalsi, Manmohan S.; Alvarez, Patricio D.

    2010-09-21

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  6. Corium protection assembly

    Science.gov (United States)

    Gou, Perng-Fei; Townsend, Harold E.; Barbanti, Giancarlo

    1994-01-01

    A corium protection assembly includes a perforated base grid disposed below a pressure vessel containing a nuclear reactor core and spaced vertically above a containment vessel floor to define a sump therebetween. A plurality of layers of protective blocks are disposed on the grid for protecting the containment vessel floor from the corium.

  7. Spool assembly support analysis

    International Nuclear Information System (INIS)

    This document provides the wind/seismic analysis and evaluation for the pump pit spool assemblies. Hand calculations were used for the analysis. UBC, AISC, and load factors were used in this evaluation. The results show that the actual loads are under the allowable loads and all requirements are met

  8. Turbomachine blade assembly

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Crespo, Andres Jose

    2016-11-01

    Embodiments of the present disclosure include a system comprising a turbomachine blade assembly having a blade portion, a shank portion, and a mounting portion, wherein the blade portion, the shank portion, and the mounting portion comprise a first plurality of plies extending from a tip of the airfoil to a base of the dovetail.

  9. Top-down assembly design using assembly features

    Institute of Scientific and Technical Information of China (English)

    石万凯; DENEUX; Dominique; 等

    2002-01-01

    The primary task of top-down assembly desig is to define a product's detailed physical description satisfying its functional requirements identified during the functional design phase.The implementation of this design process requires two things,that is ,product functional representation and a general assembly model.Product functions are not only the formulation of a customer's needs,but also the input data of assembly design.A general assembly model is to support the evolving process of the elaboration of a product structure.The assembly feature of extended concept is taken as a functional carrier,which is a generic relation among assembly-modeled entities.The model of assembly features describes the link between product functions and form features of parts.On the basis of this link,the propagation of design modifications is discussed so as to preserve the functionality and the coherence of the assembly model.The formal model of assembly design process describes the top-down process of creating an assembly model.This formal model is represented by the combination of assembly feature operations,the assembly model and the evaluation process.A design case study is conducted to verify the applicability of the presented approaches.

  10. Optical Space Telescope Assembly Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Optical Space Telescope Assembly (OSTA) task is to demonstrate the technology readiness of assembling large space telescopes on orbit in 2015. This task is an...

  11. School Assemblies: The Lost Art.

    Science.gov (United States)

    Beach, Daniel R.

    1979-01-01

    Guidelines and suggestions are offered for successful school assemblies. The school assembly should be a positive event; an occasion for developing unity, group loyalty, and desirable audience habits. (Author/MLF)

  12. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  13. Reflector-moderated critical assemblies

    International Nuclear Information System (INIS)

    Experiments with reflector-moderated critical assemblies were part of the Rover Program at the Los Alamos Scientific Laboratory (LASL). These assemblies were characterized by thick D2O or beryllium reflectors surrounding large cavities that contained highly enriched uranium at low average densities. Because interest in this type of system has been revived by LASL Plasma Cavity Assembly studies, more detailed descriptions of the early assemblies than had been available in the unclassified literature are provided. (U.S.)

  14. Measurement Technology for Engine Assembly

    Institute of Scientific and Technical Information of China (English)

    GAO Li; ZHENG Zeyu; DAI Shangping

    2006-01-01

    In many industrial, it is often necessary to analyze the engine assembly. This paper introduces three kinds of new technologies on the assembly line of engine in recent years, it have played the positive role in improving the quality of assembling.

  15. Low inductance busbar assembly

    Science.gov (United States)

    Holbrook, Meghan Ann

    2010-09-21

    A busbar assembly for electrically coupling first and second busbars to first and second contacts, respectively, on a power module is provided. The assembly comprises a first terminal integrally formed with the first busbar, a second terminal integrally formed with the second busbar and overlapping the first terminal, a first bridge electrode having a first tab electrically coupled to the first terminal and overlapping the first and second terminals, and a second tab electrically coupled to the first contact, a second bridge electrode having a third tab electrically coupled to the second terminal, and overlapping the first and second terminals and the first tab, and a fourth tab electrically coupled to the second contact, and a fastener configured to couple the first tab to the first terminal, and the third tab to the second terminal.

  16. Fuel assemblies chemical cleaning

    International Nuclear Information System (INIS)

    NPP Paks found a thermal-hydraulic anomaly in the reactor core during cycle 14 that was caused by corrosion product deposits on fuel assemblies (FAs) that increased the hydraulic resistance of the FAs. Consequently, the coolant flow through the FAs was insufficient resulting in a temperature asymmetry inside the reactor core. Based on this fact NPP Paks performed differential pressure measurements of all fuel assemblies in order to determine the hydraulic resistance and subsequently the limit values for the hydraulic acceptance of FAs to be used. Based on the hydraulic investigations a total number of 170 FAs was selected for cleaning. The necessity for cleaning the FAs was explained by the fact that the FAs were subjected to a short term usage in the reactor core only maximum of 1,5 years and had still a capacity for additional 2 fuel cycles. (authors)

  17. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Purpose: To increase the fuel assembly rigidity while making balance in view of the dimension thereby improving the earthquake proofness. Constitution: In a nuclear fuel assembly having a control rod guide thimble tube, the gap between the thimble tube and fuel insert (inner diameter of the guiding thimble tube-outer diameter of the fuel insert) is made greater than 1.0 mm. Further, the wall thickness of the thimble tube is made to about 4 - 5 % of the outer diameter, while the flowing fluid pore cross section S in the thimble tube is set as: S = S0 x A0/A where S0: cross section of the present flowing fluid pore, A: effective cross section after improvement, = Π/4(d2 - D2) in which d is the thimble tube inner diameter and the D is the fuel insert outer diameter. A0: present effective cross section. (Seki, T.)

  18. Fuel nozzle assembly

    Science.gov (United States)

    Johnson, Thomas Edward; Ziminsky, Willy Steve; Lacey, Benjamin Paul; York, William David; Stevenson, Christian Xavier

    2011-08-30

    A fuel nozzle assembly is provided. The assembly includes an outer nozzle body having a first end and a second end and at least one inner nozzle tube having a first end and a second end. One of the nozzle body or nozzle tube includes a fuel plenum and a fuel passage extending therefrom, while the other of the nozzle body or nozzle tube includes a fuel injection hole slidably aligned with the fuel passage to form a fuel flow path therebetween at an interface between the body and the tube. The nozzle body and the nozzle tube are fixed against relative movement at the first ends of the nozzle body and nozzle tube, enabling the fuel flow path to close at the interface due to thermal growth after a flame enters the nozzle tube.

  19. Uniform Test Assembly

    Science.gov (United States)

    Belov, Dmitry I.

    2008-01-01

    In educational practice, a test assembly problem is formulated as a system of inequalities induced by test specifications. Each solution to the system is a test, represented by a 0-1 vector, where each element corresponds to an item included (1) or not included (0) into the test. Therefore, the size of a 0-1 vector equals the number of items "n"…

  20. REACTOR NOZZLE ASSEMBLY

    Science.gov (United States)

    Capuder, F.C.; Dearwater, J.R.

    1959-02-10

    An improved nozzle assembly useful in a process for the direct reduction of uranium hexafluoride to uranium tetrafluoride by means of dissociated ammonia in a heated reaction vessel is descrlbed. The nozzle design provides for intimate mixing of the two reactants and at the same time furnishes a layer of dissociated ammonia adjacent to the interior wall of the reaction vessel, thus preventing build-up of the reaction product on the vessel wall.

  1. Fourth Doctoral Student Assembly

    CERN Multimedia

    Ingrid Haug

    2016-01-01

    On 10 May, over 130 PhD students and their supervisors, from both CERN and partner universities, gathered for the 4th Doctoral Student Assembly in the Council Chamber.   The assembly was followed by a poster session, at which eighteen doctoral students presented the outcome of their scientific work. The CERN Doctoral Student Programme currently hosts just over 200 students in applied physics, engineering, computing and science communication/education. The programme has been in place since 1985. It enables students to do their research at CERN for a maximum of three years and to work on a PhD thesis, which they defend at their University. The programme is steered by the TSC committee, which holds two selection committees per year, in June and December. The Doctoral Student Assembly was opened by the Director-General, Fabiola Gianotti, who stressed the importance of the programme in the scientific environment at CERN, emphasising that there is no more rewarding activity than lear...

  2. IAHS Third Scientific Assembly

    Science.gov (United States)

    The International Association of Hydrological Sciences (IAHS) convened its Third Scientific Assembly in Baltimore, Md., May 10-19, 1989. The Assembly was attended by about 450 scientists and engineers. The attendance was highest from the U.S., as could be expected; 37 were from Canada; 22 each, Netherlands and United Kingdom; 14, Italy; 12, China; 10, Federal Republic of Germany; 8 each from France, the Republic of South Africa, and Switzerland; 7, Austria; 6 each, Finland and Japan; others were scattered among the remainder of 48 countries total.one of the cosponsors and also handled business matters for the Assembly. Other cosponsors included the International Association of Meteorology and Atmospheric Physics (IAMAP), United Nations Environmental Program (UNEP), United Nations Educational, Scientific, and Cultural Organization (UNESCO), World Meteorological Organization (WMO), and U.K. Overseas Development Authority (ODA). U.S. federal agencies serving as cosponsors included the Environmental Protection Agency, National Aeronautics and Space Administration, National Science Foundation, National Weather Service, Department of Agriculture, Department of State, and U.S. Geological Survey.

  3. Ordinary General Assembly

    CERN Multimedia

    Association du personnel

    2010-01-01

    Tuesday 20 April at 10.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 12 May 2009 Presentation and approval of the Activity Report 2009 Presentation and approval of the Financial Report 2009 Presentation and approval of the Auditors Report 2009 Programme for 2010 Presentation et and approval of the draft budget and subscription rate 2010 Modifications to the statutes of the association Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda...

  4. SCT Barrel Assembly Complete

    CERN Multimedia

    L. Batchelor

    As reported in the April 2005 issue of the ATLAS eNews, the first of the four Semiconductor Tracker (SCT) barrels, complete with modules and services, arrived safely at CERN in January of 2005. In the months since January, the other three completed barrels arrived as well, and integration of the four barrels into the entire barrel assembly commenced at CERN, in the SR1 building on the ATLAS experimental site, in July. Assembly was completed on schedule in September, with the addition of the innermost layer to the 4-barrel assembly. Work is now underway to seal the barrel thermal enclosure. This is necessary in order to enclose the silicon tracker in a nitrogen atmosphere and provide it with faraday-cage protection, and is a delicate and complicated task: 352 silicon module powertapes, 352 readout-fibre bundles, and over 400 Detector Control System sensors must be carefully sealed into the thermal enclosure bulkhead. The team is currently verifying the integrity of the low mass cooling system, which must be d...

  5. Spatially confined assembly of nanoparticles.

    Science.gov (United States)

    Jiang, Lin; Chen, Xiaodong; Lu, Nan; Chi, Lifeng

    2014-10-21

    The ability to assemble NPs into ordered structures that are expected to yield collective physical or chemical properties has afforded new and exciting opportunities in the field of nanotechnology. Among the various configurations of nanoparticle assemblies, two-dimensional (2D) NP patterns and one-dimensional (1D) NP arrays on surfaces are regarded as the ideal assembly configurations for many technological devices, for example, solar cells, magnetic memory, switching devices, and sensing devices, due to their unique transport phenomena and the cooperative properties of NPs in assemblies. To realize the potential applications of NP assemblies, especially in nanodevice-related applications, certain key issues must still be resolved, for example, ordering and alignment, manipulating and positioning in nanodevices, and multicomponent or hierarchical structures of NP assemblies for device integration. Additionally, the assembly of NPs with high precision and high levels of integration and uniformity for devices with scaled-down dimensions has become a key and challenging issue. Two-dimensional NP patterns and 1D NP arrays are obtained using traditional lithography techniques (top-down strategies) or interfacial assembly techniques (bottom-up strategies). However, a formidable challenge that persists is the controllable assembly of NPs in desired locations over large areas with high precision and high levels of integration. The difficulty of this assembly is due to the low efficiency of small features over large areas in lithography techniques or the inevitable structural defects that occur during the assembly process. The combination of self-assembly strategies with existing nanofabrication techniques could potentially provide effective and distinctive solutions for fabricating NPs with precise position control and high resolution. Furthermore, the synergistic combination of spatially mediated interactions between nanoparticles and prestructures on surfaces may play

  6. Robotic Thumb Assembly

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Bridgwater, Lyndon (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor); Goza, S. Michael (Inventor)

    2013-01-01

    An improved robotic thumb for a robotic hand assembly is provided. According to one aspect of the disclosure, improved tendon routing in the robotic thumb provides control of four degrees of freedom with only five tendons. According to another aspect of the disclosure, one of the five degrees of freedom of a human thumb is replaced in the robotic thumb with a permanent twist in the shape of a phalange. According to yet another aspect of the disclosure, a position sensor includes a magnet having two portions shaped as circle segments with different center points. The magnet provides a linearized output from a Hall effect sensor.

  7. ULTRASONIC ASSEMBLY [REVIEW

    Directory of Open Access Journals (Sweden)

    PORAV Viorica

    2015-05-01

    Full Text Available The paper exposes the possibility of machine producesers to optimize the costs of clothes assembling. Ultrasonic systems being frequently utilized have many advantages on semi products of synthetic textile and technical textile. First of all, sewing – cutting process can be accomplished under high speeds and rate of losses can be minimized. Cutting seal applications are frequently used for underwear and sportswear. Slicing and unit cutting machines, as well as portable sealing machines are available for labeling sector. Products such as bag, pocket and cover can be sewed in a seamless manner for promotion purposes. All objects in terms of accessories are obtained in same standard. Our quilting machines are preferred in worldwide due to its threadless, high quality sealing. An alternative to the classic sewing assembly, with thread and needles is ultrasonic seaming. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. Ultrasonic is defined as acoustic frequencies above the range audible to the human ear. Ultrasonic frequencies are administered to the fabric from the sonotrode of bonding machine. The high frequency and powerful energy produced, when is release in one special environment, the ultrasound heating this environment. The ability to ultrasonic weld textiles and films depend on their thermoplastic contents and the desired end results. The paper defines the weld ability of more common textiles and films. The welding refers to all types of bonding and sealing, as in point bonding of fabric, or continuous sealing of film.

  8. Progress of EMBarrel assembly

    CERN Multimedia

    Chalifour, M

    2002-01-01

    The assembly of the sixteen "M" modules into a vertical axis cylinder has been achieved last Friday, completing the first wheel of the Electromagnetic Barrel Calorimeter (see picture). With this, an important milestone in the construction of the ATLAS detector has been reached. Future steps are the rotation of the cylinder axis into horizontal position, in order to integrate the presamplers and heat exchangers by the end of October. The transportation of the wheel and its insertion into the cryostat is the next major milestone, and is planned for the beginning of 2003. The construction of the modules (the so-called "P" modules) of the second wheel is ongoing at Saclay, Annecy and CERN, and will be completed in the coming months. The assembly of the second wheel should start at CERN in February, and its insertion in the cryostat is scheduled for June 2003. This achievement is the result of a successful collaboration of all institutes involved in the construction of the EM Barrel, namely Annecy, Saclay and CE...

  9. ANNUAL GENERAL ASSEMBLY

    CERN Multimedia

    2001-01-01

    All members and beneficiaries of the Pension Fund are invited to attend the Annual General Asssembly to be held in the CERN Auditorium on Wednesday 3 October 2001 at 14.30 hrs The Agenda comprises:   Opening Remarks (P. Levaux) Some aspects of risk in a pension fund (C. Cuénoud) Annual Report 2000: Presentation and results (C. Cuénoud) Copies of the Report are available from divisional secretariats. Results of the actuarial reviews (G. Maurin) Questions from members and beneficiaries Persons wishing to ask questions are encouraged to submit them, where possible, in writing in advance, addressed to Mr C. Cuénoud, Administrator of the Fund. Conclusions (P. Levaux) As usual, participants are invited to drinks after the assembly. NB The minutes of the 2000 General Assembly are available from the Administration of the Fund (tel. + 41 22 767 91 94; e-mail Graziella.Praire@cern.ch) The English version will be published next week.

  10. Fuel assembly supporting structure

    International Nuclear Information System (INIS)

    For use in forming the core of a pressurized-water reactor, a fuel assembly supporting structure for holding a bundle of interspaced fuel rods, is formed by interspaced end pieces having holes in which the end portions of control rod guide tubes are inserted, fuel rod spacer grids being positioned by these guide tubes between the end pieces. The end pieces are fastened to the end portions of the guide tubes, to integrate the supporting structure, and in the case of at least one of the end pieces, this is done by means which releases that end piece from the guide tubes when the end pieces receive an abnormal thrust force directed towards each other and which would otherwise place the guide tubes under a compressive stress that would cause them to buckle. The spacer grids normally hold the fuel rods interspaced by distances determined by nuclear physics, and buckling of the control rod guide tubes can distort the fuel rod spacer grids with consequent dearrangement of the fuel rod interspacing. A sudden loss of pressure in a pressurized-water reactor pressure vessel can result in the pressurized coolant in the vessel discharging from the vessel at such high velocity as to result in the abnormal thrust force on the end pieces of each fuel assembly, which could cause buckling of the control rod guide tubes when the end pieces are fixed to them in the normal rigid and unyielding manner

  11. Selecting Operations for Assembler Encoding

    Directory of Open Access Journals (Sweden)

    Tomasz Praczyk

    2010-04-01

    Full Text Available Assembler Encoding is a neuro-evolutionary method in which a neural network is represented in the form of a simple program called Assembler Encoding Program. The task of the program is to create the so-called Network Definition Matrix which maintains all the information necessary to construct the network. To generate Assembler Encoding Programs and the subsequent neural networks evolutionary techniques are used.
    The performance of Assembler Encoding strongly depends on operations used in Assembler Encoding Programs. To select the most effective operations, experiments in the optimization and the predator-prey problem were carried out. In the experiments, Assembler Encoding Programs equipped with different types of operations were tested. The results of the tests are presented at the end of the paper.

  12. Ribosome Assembly as Antimicrobial Target.

    Science.gov (United States)

    Nikolay, Rainer; Schmidt, Sabine; Schlömer, Renate; Deuerling, Elke; Nierhaus, Knud H

    2016-01-01

    Many antibiotics target the ribosome and interfere with its translation cycle. Since translation is the source of all cellular proteins including ribosomal proteins, protein synthesis and ribosome assembly are interdependent. As a consequence, the activity of translation inhibitors might indirectly cause defective ribosome assembly. Due to the difficulty in distinguishing between direct and indirect effects, and because assembly is probably a target in its own right, concepts are needed to identify small molecules that directly inhibit ribosome assembly. Here, we summarize the basic facts of ribosome targeting antibiotics. Furthermore, we present an in vivo screening strategy that focuses on ribosome assembly by a direct fluorescence based read-out that aims to identify and characterize small molecules acting as primary assembly inhibitors. PMID:27240412

  13. Self-assembly via microfluidics

    OpenAIRE

    Wang, Lei; Sánchez, Samuel

    2015-01-01

    The self-assembly of amphiphilic building blocks has attracted extensive interest in myriad fields in recent years, due to their great potential in the nanoscale design of functional hybrid materials. Microfluidic techniques provide an intriguing method to control kinetic aspects of the self-assembly of molecular amphiphiles by the facile adjustment of the hydrodynamics of the fluids. Up to now, there have been several reports about one-step direct self-assembly of different building blocks w...

  14. Coded nanoscale self-assembly

    Indian Academy of Sciences (India)

    Prathyush Samineni; Debabrata Goswami

    2008-12-01

    We demonstrate coded self-assembly in nanostructures using the code seeded at the component level through computer simulations. Defects or cavities occur in all natural assembly processes including crystallization and our simulations capture this essential aspect under surface minimization constraints for self-assembly. Our bottom-up approach to nanostructures would provide a new dimension towards nanofabrication and better understanding of defects and crystallization process.

  15. Seismic behaviour of fuel assembly

    International Nuclear Information System (INIS)

    A general approach for the dynamic time-history analysis of the reactor core is presented in this paper as a part of the fuel assembly qualification program. Several detailed core models are set up to reflect the placement of the fuel assemblies within the core shroud. Peak horizontal responses are obtained for each model for the motions induced from earthquake. The dynamic responses such as fuel assembly shear force, bending moment and displacement, and spacer grid impact loads are carefully investigated. Also, the sensitivity responses are obtained for the earthquake motions and the fuel assembly non-linear response characteristics are discussed. (Author) 9 refs., 24 figs., 1 tab

  16. Seismic behaviour of fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Song, Heuy Gap; Jhung, Myung Jo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1993-11-01

    A general approach for the dynamic time-history analysis of the reactor core is presented in this paper as a part of the fuel assembly qualification program. Several detailed core models are set up to reflect the placement of the fuel assemblies within the core shroud. Peak horizontal responses are obtained for each model for the motions induced from earthquake. The dynamic responses such as fuel assembly shear force, bending moment and displacement, and spacer grid impact loads are carefully investigated. Also, the sensitivity responses are obtained for the earthquake motions and the fuel assembly non-linear response characteristics are discussed. (Author) 9 refs., 24 figs., 1 tab.

  17. Methanation assembly using multiple reactors

    Science.gov (United States)

    Jahnke, Fred C.; Parab, Sanjay C.

    2007-07-24

    A methanation assembly for use with a water supply and a gas supply containing gas to be methanated in which a reactor assembly has a plurality of methanation reactors each for methanating gas input to the assembly and a gas delivery and cooling assembly adapted to deliver gas from the gas supply to each of said methanation reactors and to combine water from the water supply with the output of each methanation reactor being conveyed to a next methanation reactor and carry the mixture to such next methanation reactor.

  18. JWST NIRCam flight mirror assemblies

    Science.gov (United States)

    Mammini, Paul V.; Holmes, Howard C.; Huff, Lynn; Jacoby, Mike S.; Lopez, Frank

    2011-10-01

    The Near Infrared Camera (NIRCam) instrument for NASA's James Webb Space Telescope (JWST) has an optical prescription which includes numerous fold mirror assemblies. The instrument will operate at 35K after experiencing launch loads at ~293K. The optic mounts must accommodate all associated thermal and mechanical stresses, plus maintain exceptional optical quality during operation. Lockheed Martin Space Systems Company (LMSSC) conceived, designed, analyzed, assembled, tested, and integrated the mirror assemblies for the NIRCam instrument. This paper covers the design, analysis, assembly, and test of two of the instruments key fold mirrors.

  19. Geometric reasoning about assembly tools

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, R.H.

    1997-01-01

    Planning for assembly requires reasoning about various tools used by humans, robots, or other automation to manipulate, attach, and test parts and subassemblies. This paper presents a general framework to represent and reason about geometric accessibility issues for a wide variety of such assembly tools. Central to the framework is a use volume encoding a minimum space that must be free in an assembly state to apply a given tool, and placement constraints on where that volume must be placed relative to the parts on which the tool acts. Determining whether a tool can be applied in a given assembly state is then reduced to an instance of the FINDPLACE problem. In addition, the author presents more efficient methods to integrate the framework into assembly planning. For tools that are applied either before or after their target parts are mated, one method pre-processes a single tool application for all possible states of assembly of a product in polynomial time, reducing all later state-tool queries to evaluations of a simple expression. For tools applied after their target parts are mated, a complementary method guarantees polynomial-time assembly planning. The author presents a wide variety of tools that can be described adequately using the approach, and surveys tool catalogs to determine coverage of standard tools. Finally, the author describes an implementation of the approach in an assembly planning system and experiments with a library of over one hundred manual and robotic tools and several complex assemblies.

  20. Rocket Assembly and Checkout Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Integrates, tests, and calibrates scientific instruments flown on sounding rocket payloads. The scientific instruments are assembled on an optical bench;...

  1. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Mantha, Pallavi [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-05-01

    In this project, the Consortium for Advanced Residential Buildings (CARB) team evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls. Wall assemblies evaluated included code minimum walls using spray foam insulation and fiberglass batts, high R-value walls at least 12 in. thick (R-40 and R-60 assemblies), and brick walls with interior insulation.

  2. Airfoil nozzle and shroud assembly

    Science.gov (United States)

    Shaffer, James E.; Norton, Paul F.

    1997-01-01

    An airfoil and nozzle assembly including an outer shroud having a plurality of vane members attached to an inner surface and having a cantilevered end. The assembly further includes a inner shroud being formed by a plurality of segments. Each of the segments having a first end and a second end and having a recess positioned in each of the ends. The cantilevered end of the vane member being positioned in the recess. The airfoil and nozzle assembly being made from a material having a lower rate of thermal expansion than that of the components to which the airfoil and nozzle assembly is attached.

  3. Next-generation transcriptome assembly

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Jeffrey A.; Wang, Zhong

    2011-09-01

    Transcriptomics studies often rely on partial reference transcriptomes that fail to capture the full catalog of transcripts and their variations. Recent advances in sequencing technologies and assembly algorithms have facilitated the reconstruction of the entire transcriptome by deep RNA sequencing (RNA-seq), even without a reference genome. However, transcriptome assembly from billions of RNA-seq reads, which are often very short, poses a significant informatics challenge. This Review summarizes the recent developments in transcriptome assembly approaches - reference-based, de novo and combined strategies-along with some perspectives on transcriptome assembly in the near future.

  4. Conduit coupling assembly

    International Nuclear Information System (INIS)

    A conduit coupling assembly for coupling pipes with an interposed seal has a first part for receiving a pipe and is in splined engagement with a bush fixed to a pipe. A second part having radial fingers so that it can be turned by a manipulator, has a threaded engagement with the first part which is the same hand but different pitch to a threaded engagement between the second part and the bush. Pitches of 8:7 for couplings will give a mechanical advantage of 56:1 thus reducing the force needed to obtain a given axial movement of the bush and thus of the pipe and compression of the seal. (author)

  5. Subcritical nuclear assembly

    International Nuclear Information System (INIS)

    A Subcritical Nuclear Assembly is a device where the nuclear-fission chain reaction is initiated and maintained using an external neutron source. It is a valuable educational and research tool where in a safe way many reactor parameters can be measured. Here, we have used the Wigner-Seitz method in the six-factor formula to calculate the effective multiplication factor of a subcritical nuclear reactor Nuclear Chicago model 9000. This reactor has approximately 2500 kg of natural uranium heterogeneously distributed in slugs. The reactor uses a 239PuBe neutron source that is located in the center of an hexagonal array. Using Monte Carlo methods, with the MCNP5 code, a three-dimensional model of the subcritical reactor was designed to estimate the effective multiplication factor, the neutron spectra, the total and thermal neutron fluences along the radial and axial axis. With the neutron spectra in two locations outside the reactor the ambient dose equivalent were estimated. (Author)

  6. Cilium assembly and disassembly

    Science.gov (United States)

    2016-01-01

    The primary cilium is an antenna-like, immotile organelle present on most types of mammalian cells, which interprets extracellular signals that regulate growth and development. Although once considered a vestigial organelle, the primary cilium is now the focus of considerable interest. We now know that ciliary defects lead to a panoply of human diseases, termed ciliopathies, and the loss of this organelle may be an early signature event during oncogenic transformation. Ciliopathies include numerous seemingly unrelated developmental syndromes, with involvement of the retina, kidney, liver, pancreas, skeletal system and brain. Recent studies have begun to clarify the key mechanisms that link cilium assembly and disassembly to the cell cycle, and suggest new possibilities for therapeutic intervention. PMID:27350441

  7. Photovoltaic cell assembly

    Science.gov (United States)

    Beavis, Leonard C.; Panitz, Janda K. G.; Sharp, Donald J.

    1990-01-01

    A photovoltaic assembly for converting high intensity solar radiation into lectrical energy in which a solar cell is separated from a heat sink by a thin layer of a composite material which has excellent dielectric properties and good thermal conductivity. This composite material is a thin film of porous Al.sub.2 O.sub.3 in which the pores have been substantially filled with an electrophoretically-deposited layer of a styrene-acrylate resin. This composite provides electrical breakdown strengths greater than that of a layer consisting essentially of Al.sub.2 O.sub.3 and has a higher thermal conductivity than a layer of styrene-acrylate alone.

  8. Fluid cooled electrical assembly

    Science.gov (United States)

    Rinehart, Lawrence E.; Romero, Guillermo L.

    2007-02-06

    A heat producing, fluid cooled assembly that includes a housing made of liquid-impermeable material, which defines a fluid inlet and a fluid outlet and an opening. Also included is an electrical package having a set of semiconductor electrical devices supported on a substrate and the second major surface is a heat sink adapted to express heat generated from the electrical apparatus and wherein the second major surface defines a rim that is fit to the opening. Further, the housing is constructed so that as fluid travels from the fluid inlet to the fluid outlet it is constrained to flow past the opening thereby placing the fluid in contact with the heat sink.

  9. Assembly sequencing with toleranced parts

    Energy Technology Data Exchange (ETDEWEB)

    Latombe, J.C. [Stanford Univ., CA (United States). Robotics Lab.; Wilson, R.H. [Sandia National Labs., Albuquerque, NM (United States). Intelligent Systems and Robotics Center

    1995-02-21

    The goal of assembly sequencing is to plan a feasible series of operations to construct a product from its individual parts. Previous research has thoroughly investigated assembly sequencing under the assumption that parts have nominal geometry. This paper considers the case where parts have toleranced geometry. Its main contribution is an efficient procedure that decides if a product admits an assembly sequence with infinite translations that is feasible for all possible instances of the components within the specified tolerances. If the product admits one such sequence, the procedure can also generate it. For the cases where there exists no such assembly sequence, another procedure is proposed which generates assembly sequences that are feasible only for some values of the toleranced dimensions. If this procedure produces no such sequence, then no instance of the product is assemblable. Finally, this paper analyzes the relation between assembly and disassembly sequences in the presence of toleranced parts. This work assumes a simple, but non-trivial tolerance language that falls short of capturing all imperfections of a manufacturing process. Hence, it is only one step toward assembly sequencing with toleranced parts.

  10. The Bicycle Assembly Line Game

    Science.gov (United States)

    Klotz, Dorothy

    2011-01-01

    "The Bicycle Assembly Line Game" is a team-based, in-class activity that helps students develop a basic understanding of continuously operating processes. Each team of 7-10 students selects one of seven prefigured bicycle assembly lines to operate. The lines are run in real-time, and the team that operates the line that yields the…

  11. WHATS IN A CELL ASSEMBLY

    NARCIS (Netherlands)

    DALENOORT, GJ; DEVRIES, PH

    1995-01-01

    The cell assembly as a simple attractor cannot explain many cognitive phenomena. It must be a highly structured network that can sustain highly structured excitation patterns. Moreover, a cell assembly must be more widely distributed in space than on a square millimeter.

  12. What was the Assembly Line?

    DEFF Research Database (Denmark)

    Nye, David

    2010-01-01

    The assembly line is still evolving a century after its invention, and it was not a distinct historical stage, nor was it part of an inevitable sequence that followed "Taylorism."......The assembly line is still evolving a century after its invention, and it was not a distinct historical stage, nor was it part of an inevitable sequence that followed "Taylorism."...

  13. Newnes electronics assembly pocket book

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Produced in association with the Engineering Training Authority with contributions from dozens of people in the electronics industry. The material covers common skills in electrical and electronic engineering and concentrates mainly on wiring and assembly. 'Newnes Electronics Assembly Pocket Book' is for electronics technicians, students and apprentices.

  14. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, L.; Mantha, P.

    2013-05-01

    The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

  15. Advanced gray rod control assembly

    Science.gov (United States)

    Drudy, Keith J; Carlson, William R; Conner, Michael E; Goldenfield, Mark; Hone, Michael J; Long, Jr., Carroll J; Parkinson, Jerod; Pomirleanu, Radu O

    2013-09-17

    An advanced gray rod control assembly (GRCA) for a nuclear reactor. The GRCA provides controlled insertion of gray rod assemblies into the reactor, thereby controlling the rate of power produced by the reactor and providing reactivity control at full power. Each gray rod assembly includes an elongated tubular member, a primary neutron-absorber disposed within the tubular member said neutron-absorber comprising an absorber material, preferably tungsten, having a 2200 m/s neutron absorption microscopic capture cross-section of from 10 to 30 barns. An internal support tube can be positioned between the primary absorber and the tubular member as a secondary absorber to enhance neutron absorption, absorber depletion, assembly weight, and assembly heat transfer characteristics.

  16. ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    B. Gorpani

    2000-06-26

    The Assembly Transfer System (ATS) receives, cools, and opens rail and truck transportation casks from the Carrier/Cask Handling System (CCHS). The system unloads transportation casks consisting of bare Spent Nuclear Fuel (SNF) assemblies, single element canisters, and Dual Purpose Canisters (DPCs). For casks containing DPCs, the system opens the DPCs and unloads the SNF. The system stages the assemblies, transfer assemblies to and from fuel-blending inventory pools, loads them into Disposal Containers (DCs), temporarily seals and inerts the DC, decontaminates the DC and transfers it to the Disposal Container Handling System. The system also prepares empty casks and DPCs for off-site shipment. Two identical Assembly Transfer System lines are provided in the Waste Handling Building (WHB). Each line operates independently to handle the waste transfer throughput and to support maintenance operations. Each system line primarily consists of wet and dry handling areas. The wet handling area includes a cask transport system, cask and DPC preparation system, and a wet assembly handling system. The basket transport system forms the transition between the wet and dry handling areas. The dry handling area includes the dry assembly handling system, assembly drying system, DC preparation system, and DC transport system. Both the wet and dry handling areas are controlled by the control and tracking system. The system operating sequence begins with moving transportation casks to the cask preparation area. The cask preparation operations consist of cask cavity gas sampling, cask venting, cask cool-down, outer lid removal, and inner shield plug lifting fixture attachment. Casks containing bare SNF (no DPC) are filled with water and placed in the cask unloading pool. The inner shield plugs are removed underwater. For casks containing a DPC, the cask lid(s) is removed, and the DPC is penetrated, sampled, vented, and cooled. A DPC lifting fixture is attached and the cask is placed

  17. Development of a tuneable test problem generator for assembly sequence planning and assembly line balancing

    OpenAIRE

    Ab Rashid, Mohd Fadzil Faisae; Hutabarat, Windo; Tiwari, Ashutosh

    2012-01-01

    Assembly optimisation activities that involve assembly sequence planning and assembly line balancing have been extensively studied because of the importance of optimal assembly efficiency to manufacturing competitiveness. Numerous research works in assembly sequence planning and assembly line balancing mainly focus on developing algorithms to solve problems and to optimise assembly sequence planning and assembly line balancing. However, there is a scarcity in works that focus on developing pr...

  18. Subcritical nuclear assembly

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-08-15

    A Subcritical Nuclear Assembly is a device where the nuclear-fission chain reaction is initiated and maintained using an external neutron source. It is a valuable educational and research tool where in a safe way many reactor parameters can be measured. Here, we have used the Wigner-Seitz method in the six-factor formula to calculate the effective multiplication factor of a subcritical nuclear reactor Nuclear Chicago model 9000. This reactor has approximately 2500 kg of natural uranium heterogeneously distributed in slugs. The reactor uses a {sup 239}PuBe neutron source that is located in the center of an hexagonal array. Using Monte Carlo methods, with the MCNP5 code, a three-dimensional model of the subcritical reactor was designed to estimate the effective multiplication factor, the neutron spectra, the total and thermal neutron fluences along the radial and axial axis. With the neutron spectra in two locations outside the reactor the ambient dose equivalent were estimated. (Author)

  19. ITER assembly and maintenance

    International Nuclear Information System (INIS)

    This document is intended to describe the work conducted by the ITER Assembly and Maintenance (A and M) Design Unit and the supporting home teams during the ITER Conceptual Design Activities, carried out from 1988 through 1990. Its content consists of two main sections, i.e., Chapter III, which describes the identified tasks to be performed by the A and M system and a general description of the required equipment; and Chapter IV, which provides a more detailed description of the equipment proposed to perform the assigned tasks. A two-stage R and D program is now planned, i.e., (1) a prototype equipment functional tests using full scale mock-ups and (2) a full scale integration demonstration test facility with real components (vacuum vessel with ports, blanket modules, divertor modules, armor tiles, etc.). Crucial in-vessel and ex-vessel operations and the associated remote handling equipment, including handling of divertor plates and blanket modules will be demonstrated in the first phase, whereby the database needed to proceed with the engineering phase will be acquired. The second phase will demonstrate the ability of the overall system to execute the required maintenance procedures and evaluate the performance of the prototype equipment

  20. Flexible Foot Test Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, C.H.; /Fermilab

    1987-04-27

    A test model of the flexible foot support was constructed early in the design stages to check its reactions to applied loads. The prototype was made of SS 304 and contained four vertical plates as opposed to the fourteen Inconel 718 plates which comprise the actual structure. Due to the fact that the prototype was built before the design of the support was finalized, the plate dimensions are different from those of the actual proposed design (i.e. model plate thickness is approximately one-half that of the actual plates). See DWG. 3740.210-MC-222376 for assembly details of the test model and DWG. 3740.210-MB-222377 for plate dimensions. This stanchion will be required to not only support the load of the inner vessel of the cryostat and its contents, but it must also allow for the movement of the vessel due to thermal contraction. Assuming that each vertical plate acts as a column, then the following formula from the Manual of Steel Construction (American Institute of Steel Construction, Inc., Eigth edition, 1980) can be applied to determine whether or not such columns undergoing simultaneous axial compression and transverse loading are considered safe for the given loading. The first term is representative of the axially compressive stress, and the second term, the bending stress. If the actual compressive stress is greater than 15% of the allowable compressive stress, then there are additional considerations which must be accounted for in the bending stress term.

  1. Bearing assemblies, apparatuses, and motor assemblies using the same

    Science.gov (United States)

    Sexton, Timothy N.; Cooley, Craig H.; Knuteson, Cody W.

    2015-12-29

    Various embodiments of the invention relate to bearing assemblies, apparatuses and motor assemblies that include geometric features configured to impart a selected amount of heat transfer and/or hydrodynamic film formation. In an embodiment, a bearing assembly may include a plurality of superhard bearing pads distributed circumferentially about an axis. At least some of the plurality of superhard bearing pads may include a plurality of sub-superhard bearing elements defining a bearing surface. At least some of the plurality of sub-superhard bearing elements may be spaced from one another by one or more voids to impart a selected amount of heat transfer and hydrodynamic film formation thereon during operation. The bearing assembly may also include a support ring that carries the plurality of superhard bearing pads. In addition, at least a portion of the sub-superhard bearing elements may extend beyond the support ring.

  2. Drive piston assembly for a valve actuator assembly

    Science.gov (United States)

    Sun, Zongxuan

    2010-02-23

    A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

  3. Illustrating how mechanical assemblies work

    KAUST Repository

    Mitra, Niloy J.

    2013-01-01

    How-things-work visualizations use a variety of visual techniques to depict the operation of complex mechanical assemblies. We present an automated approach for generating such visualizations. Starting with a 3D CAD model of an assembly, we first infer the motions of the individual parts and the interactions across the parts based on their geometry and a few user-specified constraints. We then use this information to generate visualizations that incorporate motion arrows, frame sequences, and animation to convey the causal chain of motions and mechanical interactions across parts. We demonstrate our system on a wide variety of assemblies. © 2013 ACM 0001-0782/13/01.

  4. Illustrating how mechanical assemblies work

    KAUST Repository

    Mitra, Niloy J.

    2010-07-26

    How things work visualizations use a variety of visual techniques to depict the operation of complex mechanical assemblies. We present an automated approach for generating such visualizations. Starting with a 3D CAD model of an assembly, we first infer the motions of individual parts and the interactions between parts based on their geometry and a few user specified constraints. We then use this information to generate visualizations that incorporate motion arrows, frame sequences and animation to convey the causal chain of motions and mechanical interactions between parts. We present results for a wide variety of assemblies. © 2010 ACM.

  5. Multiple complementary gas distribution assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Tuoh-Bin; Melnik, Yuriy; Pang, Lily L; Tuncel, Eda; Nguyen, Son T; Chen, Lu

    2016-04-05

    In one embodiment, an apparatus includes a first gas distribution assembly that includes a first gas passage for introducing a first process gas into a second gas passage that introduces the first process gas into a processing chamber and a second gas distribution assembly that includes a third gas passage for introducing a second process gas into a fourth gas passage that introduces the second process gas into the processing chamber. The first and second gas distribution assemblies are each adapted to be coupled to at least one chamber wall of the processing chamber. The first gas passage is shaped as a first ring positioned within the processing chamber above the second gas passage that is shaped as a second ring positioned within the processing chamber. The gas distribution assemblies may be designed to have complementary characteristic radial film growth rate profiles.

  6. Direct hierarchical assembly of nanoparticles

    Science.gov (United States)

    Xu, Ting; Zhao, Yue; Thorkelsson, Kari

    2014-07-22

    The present invention provides hierarchical assemblies of a block copolymer, a bifunctional linking compound and a nanoparticle. The block copolymers form one micro-domain and the nanoparticles another micro-domain.

  7. Chromatin assembly using Drosophila systems.

    Science.gov (United States)

    Fyodorov, Dmitry V; Levenstein, Mark E

    2002-05-01

    To successfully study chromatin structure and activity in vitro, it is essential to have a chromatin assembly system that will prepare extended nucleosome arrays with highly defined protein content that resemble bulk chromatin isolated from living cell nuclei in terms of periodicity and nucleosome positioning. The Drosophila ATP-dependent chromatin assembly system described in this unit meets these requirements. The end product of the reaction described here has highly periodic extended arrays with physiologic spacing and positioning of the nucleosomes.

  8. Another successful Doctoral Student Assembly

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    On Wednesday 2 April, CERN hosted its third Doctoral Student Assembly in the Council Chamber.   CERN PhD students show off their posters in CERN's Main Building. Speaking to a packed house, Director-General Rolf Heuer gave the assembly's opening speech and introduced the poster session that followed. Seventeen CERN PhD students presented posters on their work, and were greeted by their CERN and University supervisors. It was a very successful event!

  9. Assembly delay line pulse generators

    CERN Multimedia

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  10. DNA controlled assembly of liposomes

    DEFF Research Database (Denmark)

    Vogel, Stefan; Jakobsen, Ulla; Simonsen, Adam Cohen

    2009-01-01

    DNA-encoding of solid nanoparticles requires surfacechemistry, which is often tedious and not generally applicable. In the present study non-covalently attached DNA are used to assemble soft nanoparticles (liposomes) in solution. This process displays remarkably sharp thermal transitions from...... assembled to disassembled state for which reason this method allows easy and fast detection of polynucleotides (e.g. DNA or RNA), including single nucleotide polymorphisms as well as insertions and deletions....

  11. Los Alamos Critical Assemblies Facility

    International Nuclear Information System (INIS)

    The Critical Assemblies Facility of the Los Alamos National Laboratory has been in existence for thirty-five years. In that period, many thousands of measurements have been made on assemblies of 235U, 233U, and 239Pu in various configurations, including the nitrate, sulfate, fluoride, carbide, and oxide chemical compositions and the solid, liquid, and gaseous states. The present complex of eleven operating machines is described, and typical applications are presented

  12. Personal Factors Determining Patient Satisfaction with All-Ceramic Crown Treatment for Single Anterior Teeth.

    Science.gov (United States)

    Zou, Yun; Zhan, DeSong

    2016-01-01

    The Eysenck Personality Questionnaire's (EPQ) N value (neuroticism) was used to evaluate information from 158 patients before ceramic crown treatment. Patient satisfaction was also evaluated using a satisfaction questionnaire 2 weeks post treatment. Patient expectations were not correlated with sex, age, or N value, and sex was not correlated with patient satisfaction other than in relation to crown shape. Total esthetic satisfaction and feature improvement were positively correlated with age, while satisfaction for five specific criteria was negatively correlated with N value and overall expectation. These observations underscore the importance of considering the physical and psychologic aspects of patient care when planning dental treatment. PMID:27611752

  13. Effect of etchant variability on shear bond strength of all ceramic restorations - an in vitro study

    OpenAIRE

    Pattanaik, Seema; Wadkar, Aarti P.

    2011-01-01

    The present study was carried out to evaluate the effect of pre-luting surface treatments by 3 different etchant used at 3 different etching periods and their effect on shear bond strength of IPS Empress 2 luted to tooth by dual cure resin cement. Fifty samples of ceramic were divided into four groups as group I control group: No surface treatment, group II: Etched with Hydrofluoric (HF) acid (4.9%), group III: Etched with Ammonium bifluoride acid (9.4%) and group IV: Etched with Phosphoric a...

  14. Effect of etchant variability on shear bond strength of all ceramic restorations - an in vitro study.

    Science.gov (United States)

    Pattanaik, Seema; Wadkar, Aarti P

    2011-03-01

    The present study was carried out to evaluate the effect of pre-luting surface treatments by 3 different etchant used at 3 different etching periods and their effect on shear bond strength of IPS Empress 2 luted to tooth by dual cure resin cement. Fifty samples of ceramic were divided into four groups as group I control group: No surface treatment, group II: Etched with Hydrofluoric (HF) acid (4.9%), group III: Etched with Ammonium bifluoride acid (9.4%) and group IV: Etched with Phosphoric acid (37%). Group II, III and IV were further divided into 3 Subgroups; namely A, B and C according to the etching periods (20, 60 and 120 s) respectively. The shear bond strength was determined by using a Universal testing Machine. The morphological changes of the surface treated ceramic samples prior to luting to tooth and mode of the fracture failure after shear bond test were observed by using a Scanning Electron Microscope. The mean shear bond strength was highest when IPS Empress 2 ceramic samples were surface treated using 4.9% Hydrofluoric acid gel and 9.4% Ammonium bifluoride acid for 120 s. The least mean shear bond strength was noticed in case of control group, where no surface treatment was done and samples treated by 37% Phosphoric acid. Thus it could be concluded, that Ammonium bifluoride could be an appropriate alternative to be used instead of HF acid. 120 s etching showed highest bond strength values for HF acid (4.9%) and Ammonium bifluoride (9.4%).

  15. CAD/CAM All Ceramic Dental Restorations on Implants: A Panacea or a Challenge?

    OpenAIRE

    Tamaki Yukimichi; Hotta Yasuhiro; Kunii Jun; Kuriyama Soichi; Higuchi Daisuke; Miyazaki Takashi

    2010-01-01

    機械的耐久力を評価するために母橋脚歯モデルに付けるCAD/CAM粉砕陶材の破面検査を行い、ブリッジ修復のため角度のついた骨組みのCAD/CAM粉砕・焼結後ジルコニアのフィット性を評価するために、骨組みと橋脚歯の切断面の辺縁セメントスペースを測定した。陶材とジルコニアの結合力は、ジルコニア試験品に接着させたと陶材とジルコニア試験品に融合させた陶材の曲げ強度を測定することで評価した。CAD/CAMで加工した或いは焼結後ジルコニアの骨組みのフィット性は優秀で、インプラントのセメント保留上部構造物の臨床採用の基準を満足するものであった。しかし、従来法でのジルコニア骨組みへの陶材融合はいくつかの欠点を有する。CAD/CAM全セラミック修復のみではまだ解決策にはなっていないが、インプラント義歯用の大変有用な材料である。...

  16. CAD/CAM Solutions for Minimally Invasive All-Ceramic Rehabilitation of Extended Erosive Lesions.

    Science.gov (United States)

    Guess Gierthmuehlen, Petra C; Steger, Enrico

    2016-05-01

    Dental erosion is a global oral health problem that can lead to significant functional and esthetic impairments of the affected patients. Treatment of severe cases with augmented loss of the vertical dimension of occlusion (VDO) represents a challenge for both the dental team and the patient. CAD/CAM technology was used in the presented case to analyze the interocclusal space. Based on a virtual wax-up of the final restorations, CAD/CAM-fabricated preparation splints served as a guide and ensured a most minimally invasive preparation design. Milled polymer provisionals enabled the patient to visualize the final treatment outcome and served as a fracture-resistant temporary restoration to test the increased VDO. Monolithic lithium-disilicate ceramic, defect-oriented restorations with reduced ceramic thickness enabled a functional and reliable reconstruction of the severely compromised dentition. This case report documents a practical, digital approach and discusses the advantages related to treatment time, ease of treatment, and predictability. PMID:27419357

  17. Molecular self-assembly advances and applications

    CERN Document Server

    Dequan, Alex Li

    2012-01-01

    In the past several decades, molecular self-assembly has emerged as one of the main themes in chemistry, biology, and materials science. This book compiles and details cutting-edge research in molecular assemblies ranging from self-organized peptide nanostructures and DNA-chromophore foldamers to supramolecular systems and metal-directed assemblies, even to nanocrystal superparticles and self-assembled microdevices

  18. 49 CFR 572.186 - Abdomen assembly.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Abdomen assembly. 572.186 Section 572.186... Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000) is part of the dummy assembly shown in drawing 175-0000 including load sensors specified in §...

  19. 49 CFR 572.113 - Neck assembly.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Neck assembly. 572.113 Section 572.113... 50th Percentile Male § 572.113 Neck assembly. The head/neck assembly consists of the parts 78051-61X...) Test procedure. (1) Soak the head and neck assembly in a test environment at any temperature between...

  20. 48 CFR 239.7409 - Special assembly.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Special assembly. 239.7409... Services 239.7409 Special assembly. (a) Special assembly is the designing, manufacturing, arranging... general use equipment. (b) Special assembly rates and charges shall be based on estimated costs....

  1. 49 CFR 572.112 - Head assembly.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly...

  2. A lightweight suction gripper for micro assembly

    NARCIS (Netherlands)

    Bos, E.J.C.; Bullema, J.E.; Delbressine, F.L.M.; Schellekens, P.H.J.; Dietzel, A.H.

    2008-01-01

    Assembly is a crucial part in the realization of a product. Compared to assembly in the macro world, assembly in the micro world is influenced by scaling effects. These include surface forces, high requirements on placement uncertainty and small product dimensions. Conventional high-speed assembly i

  3. Product lifecycle-oriented virtual assembly technology

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-hua; NING Ru-xin; YAO Jun; WAN Bi-le

    2006-01-01

    VA (virtual assembly) provides a more efficient,intuitive and convenient method for assembly process modeling,simulation and analysis.Previous researches about VA are almost isolated and dispersive,and have not established the understanding and definition of VA from a macroscopical and integrated view.Based on the analysis of the connotations of VA,a PLO-VATA (product lifecycle-oriented virtual assembly technology architecture) is proposed,in this architecture,VA is decomposed into four basic elements:principles and methodology of DFA (design for assembly),assembly analysis and evaluation,virtual assembly model and virtual assembly toolkits.Immersion,concurrence,integration and collaboration are the four main characteristics of VA being put forward.The key techniques of VA including virtual assembly model,virtual assembly analysis and evaluation,and virtual assembly process planning are discussed.Finally,a prototype system is built to validate the feasibility of the proposed method.

  4. Assembly of lamins in vitro

    Institute of Scientific and Technical Information of China (English)

    MINGUNGWEI; XIANGJUNTONG; 等

    1996-01-01

    After lamins A,B and C were isolated and purified from rat liver,their assembly properties were examined by electron microscopy and scanning tunneling microscopy by electron microscopy and scanning tunneling microscopy using negative staining and the glycerol coating method,respectively.By varying the assembly time or the ionic conditions under which polymerization takes place,we have observed different stages of lamin assembly,which may provide clues on the structure of the 10 nm lamin filaments.At the first level of structural organization,two lamin polypeptides associate laterally into dimers with the two domains being parallel and in register.At the second level of structural organization,two dimers associate in a half-staggered and antiparallel fashion to form a tetramer 75 nm in length.At the third level of structural organization,4-10 lamin tetramers associate laterally in register to form 75 nm long 10nm filaments,which in turn combine head to head into long,fully assembled lamin filaments.The assembled lamin filaments are nonpolar.

  5. Dynamics of assembly production flow

    CERN Document Server

    Ezaki, Takahiro; Nishinari, Katsuhiro

    2015-01-01

    Despite recent developments in management theory, maintaining a manufacturing schedule remains difficult because of production delays and fluctuations in demand and supply of materials. The response of manufacturing systems to such disruptions to dynamic behavior has been rarely studied. To capture these responses, we investigate a process that models the assembly of parts into end products. The complete assembly process is represented by a directed tree, where the smallest parts are injected at leaves and the end products are removed at the root. A discrete assembly process, represented by a node on the network, integrates parts, which are then sent to the next downstream node as a single part. The model exhibits some intriguing phenomena, including overstock cascade, phase transition in terms of demand and supply fluctuations, nonmonotonic distribution of stockout in the network, and the formation of a stockout path and stockout chains. Surprisingly, these rich phenomena result from only the nature of distr...

  6. FUEL ASSEMBLY SHAKER TEST SIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Klymyshyn, Nicholas A.; Sanborn, Scott E.; Adkins, Harold E.; Hanson, Brady D.

    2013-05-30

    This report describes the modeling of a PWR fuel assembly under dynamic shock loading in support of the Sandia National Laboratories (SNL) shaker test campaign. The focus of the test campaign is on evaluating the response of used fuel to shock and vibration loads that a can occur during highway transport. Modeling began in 2012 using an LS-DYNA fuel assembly model that was first created for modeling impact scenarios. SNL’s proposed test scenario was simulated through analysis and the calculated results helped guide the instrumentation and other aspects of the testing. During FY 2013, the fuel assembly model was refined to better represent the test surrogate. Analysis of the proposed loads suggested the frequency band needed to be lowered to attempt to excite the lower natural frequencies of the fuel assembly. Despite SNL’s expansion of lower frequency components in their five shock realizations, pretest predictions suggested a very mild dynamic response to the test loading. After testing was completed, one specific shock case was modeled, using recorded accelerometer data to excite the model. Direct comparison of predicted strain in the cladding was made to the recorded strain gauge data. The magnitude of both sets of strain (calculated and recorded) are very low, compared to the expected yield strength of the Zircaloy-4 material. The model was accurate enough to predict that no yielding of the cladding was expected, but its precision at predicting micro strains is questionable. The SNL test data offers some opportunity for validation of the finite element model, but the specific loading conditions of the testing only excite the fuel assembly to respond in a limited manner. For example, the test accelerations were not strong enough to substantially drive the fuel assembly out of contact with the basket. Under this test scenario, the fuel assembly model does a reasonable job of approximating actual fuel assembly response, a claim that can be verified through

  7. Workload analyse of assembling process

    Science.gov (United States)

    Ghenghea, L. D.

    2015-11-01

    The workload is the most important indicator for managers responsible of industrial technological processes no matter if these are automated, mechanized or simply manual in each case, machines or workers will be in the focus of workload measurements. The paper deals with workload analyses made to a most part manual assembling technology for roller bearings assembling process, executed in a big company, with integrated bearings manufacturing processes. In this analyses the delay sample technique have been used to identify and divide all bearing assemblers activities, to get information about time parts from 480 minutes day work time that workers allow to each activity. The developed study shows some ways to increase the process productivity without supplementary investments and also indicated the process automation could be the solution to gain maximum productivity.

  8. Assembly of Aditya upgrade tokamak

    International Nuclear Information System (INIS)

    The existing Aditya tokamak, a medium sized tokamak with limiter configuration is being upgraded to a tokamak with divertor configuration. At present the existing ADITYA tokamak has been dismantled up to bottom plinth on which the whole assembly of toroidal field (TF) coils and vacuum vessel rested. The major components of ADITYA machine includes 20 TF coils and its structural components, 9 Ohmic coils and its clamps, 4 BV coils and its clamps as well as their busbar connections, vacuum vessel and its supports and buckling cylinder, which are all being dismantled. The re-assembly of the ADITYA Upgrade tokamak started with installation and positioning of new buckling cylinder and central solenoid (TR1) coil. After that the inner sections of TF coils are placed following which in-situ winding, installation, positioning and support mounting of two pairs of new inner divertor coils have been carried out. After securing the TF coils with top I-beams the new torus shaped vacuum vessel with circular cross-section in 2 halves have been installed. The assembly of TF structural components such as top and bottom guiding wedges, driving wedges, top and bottom compression ring, inner and outer fish plates and top inverted triangle has been carried out in an appropriate sequence. The assembly of outer sections of TF coils along with the proper placements of top auxiliary TR and vertical field coils with proper alignment and positioning with the optical metrology instrument mainly completes the reassembly. Detailed re-assembly steps and challenges faced during re-assembly will be discussed in this paper. (author)

  9. DNA-guided nanoparticle assemblies

    Science.gov (United States)

    Gang, Oleg; Nykypanchuk, Dmytro; Maye, Mathew; van der Lelie, Daniel

    2013-07-16

    In some embodiments, DNA-capped nanoparticles are used to define a degree of crystalline order in assemblies thereof. In some embodiments, thermodynamically reversible and stable body-centered cubic (bcc) structures, with particles occupying <.about.10% of the unit cell, are formed. Designs and pathways amenable to the crystallization of particle assemblies are identified. In some embodiments, a plasmonic crystal is provided. In some aspects, a method for controlling the properties of particle assemblages is provided. In some embodiments a catalyst is formed from nanoparticles linked by nucleic acid sequences and forming an open crystal structure with catalytically active agents attached to the crystal on its surface or in interstices.

  10. Oscillations in molecular motor assemblies

    CERN Document Server

    Vilfan, A; Vilfan, Andrej; Frey, Erwin

    2005-01-01

    Autonomous oscillations in biological systems may have a biochemical origin or result from an interplay between force-generating and visco-elastic elements. In molecular motor assemblies the force-generating elements are molecular engines and the visco-elastic elements are stiff cytoskeletal polymers. The physical mechanism leading to oscillations depends on the particular architecture of the assembly. Existing models can be grouped into two distinct categories: systems with a {\\em delayed force activation} and {\\em anomalous force-velocity relations}. We discuss these systems within phase plane analysis known from the theory of dynamic systems and by adopting methods from control theory, the Nyquist criterion.

  11. A generalized macro-assembler

    International Nuclear Information System (INIS)

    The objective of this research is to study existing macro assemblers, and to create a generalized macro assembler, MAG-I, which is a system independent of a source language, and provides the following possibilities: development of any existing language, translation from a language to another, and creation of a new language. The user can choose his own notations to define macros. The system is implemented on an IBM 360/91 computer. Programs are written in symbolic language and the input/output software is written in Fortran

  12. STAR: a simple TAL effector assembly reaction using isothermal assembly.

    Science.gov (United States)

    Gogolok, Sabine; Garcia-Diaz, Claudia; Pollard, Steven M

    2016-01-01

    Transcription activator-like effectors (TALEs) contain modular programmable DNA binding domains. Fusing TALEs with effector domains creates synthetic transcription factors (TALE-TFs) or nucleases (TALENs), enabling precise gene manipulations. The construction of TALEs remains challenging due to their repetitive sequences. Here we report a simple TALE assembly reaction (STAR) that enables individual laboratories to generate multiple TALEs in a facile manner. STAR uses an isothermal assembly ('Gibson assembly') that is labour- and cost-effective, accessible, rapid and scalable. A small 68-part fragment library is employed, and the specific TALE repeat sequence is generated within ~8 hours. Sequence-verified TALENs or TALE-TF plasmids targeting 17 bp target sequences can be produced within three days, without the need for stepwise intermediate plasmid production. We demonstrate the utility of STAR through production of functional TALE-TFs capable of activating human SOX2 expression. STAR addresses some of the shortcomings of existing Golden Gate or solid-phase assembly protocols and enables routine production of TALE-TFs that will complement emerging CRISPR/Cas9-based reagents across diverse applications in mammalian stem cell and synthetic biology. PMID:27615025

  13. STAR: a simple TAL effector assembly reaction using isothermal assembly.

    Science.gov (United States)

    Gogolok, Sabine; Garcia-Diaz, Claudia; Pollard, Steven M

    2016-09-12

    Transcription activator-like effectors (TALEs) contain modular programmable DNA binding domains. Fusing TALEs with effector domains creates synthetic transcription factors (TALE-TFs) or nucleases (TALENs), enabling precise gene manipulations. The construction of TALEs remains challenging due to their repetitive sequences. Here we report a simple TALE assembly reaction (STAR) that enables individual laboratories to generate multiple TALEs in a facile manner. STAR uses an isothermal assembly ('Gibson assembly') that is labour- and cost-effective, accessible, rapid and scalable. A small 68-part fragment library is employed, and the specific TALE repeat sequence is generated within ~8 hours. Sequence-verified TALENs or TALE-TF plasmids targeting 17 bp target sequences can be produced within three days, without the need for stepwise intermediate plasmid production. We demonstrate the utility of STAR through production of functional TALE-TFs capable of activating human SOX2 expression. STAR addresses some of the shortcomings of existing Golden Gate or solid-phase assembly protocols and enables routine production of TALE-TFs that will complement emerging CRISPR/Cas9-based reagents across diverse applications in mammalian stem cell and synthetic biology.

  14. Focal Plane Image Assembly of Subpixel

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper describes the scanning assembly principle and construction of scanning assembly sample.The factors that affect assembly accuracy are analyzed.There are two steps in CCD focal plane scanning assembly.The first is rough assembly,and the second is accurate assembly.In this paper,the moiré fringe is introduced in judging assembly accuracy directly and accurately.The equation for optical transmission characteristics of CCD Moiré fringes is presented.The measurement of Moiré fringes can be completed when some conditions are satisfied.2D-assembly error can be obtained by using digital correlation filtering technique.Finally,the result of focal plane scanning assembly is presented.The result is in good accordance with theory.

  15. Assembly Sequence Planning for Mechanical Products

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A method for assembly sequence planning is proposed in this paper. First, two methods for assembly sequence planning are compared, which are indirect method and direct method. Then, the limits of the previous assembly planning system are pointed out. On the basis of indirect method, an improved method for assembly sequence planning is put forward. This method is composed of four parts, which are assembly modeling for products, assembly sequence representing, assembly sequence planning, and evaluation and optimization. The assembly model is established by human machine interaction, and the assembly model contains components' information and the assembly relation among the components. The assembly sequence planning is based on the breaking up of the assembly model. And/or graph is used to represent assembly sequence set. Every component which satisfies the disassembly condition is recorded as a node of an and/or graph. After the disassembly sequence and/or graph is generated, heuristic algorithm - AO* algorithm is used to search the disassembly sequence and/or graph, and the optimum assembly sequence planning is realized. This method is proved to be effective in a prototype system which is a sub-project of a state 863/CIMS research project of China - ‘Concurrent Engineering’.

  16. Quantum magnetism through atomic assembly

    NARCIS (Netherlands)

    Spinelli, A.

    2015-01-01

    This thesis presents an experimental study of magnetic structures, composed of only a few atoms. Those structures are first built atom-by-atom and then locally probed, both with a low-temperature STM. The technique that we use to assemble them is vertical atom manipulation, while to study their phy

  17. Directed Assembly of Gold Nanoparticles

    DEFF Research Database (Denmark)

    Westerlund, Axel Rune Fredrik; Bjørnholm, Thomas

    2009-01-01

    As a complement to common "top-down" lithography techniques, "bottom-up" assembly techniques are emerging as promising tools to build nanoscale structures in a predictable way. Gold nanoparticles that are stable and relatively easy to synthesize are important building blocks in many such structures...

  18. Self-assembly of cyclodextrins

    DEFF Research Database (Denmark)

    Fülöp, Z.; Kurkov, S.V.; Nielsen, T.T.;

    2012-01-01

    The design of functional cyclodextrin (CD) nanoparticles is a developing area in the field of nanomedicine. CDs can not only help in the formation of drug carriers but also increase the local concentration of drugs at the site of action. CD monomers form aggregates by self-assembly, a tendency...

  19. Monolithic fiber optic sensor assembly

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, Scott

    2015-02-10

    A remote sensor element for spectrographic measurements employs a monolithic assembly of one or two fiber optics to two optical elements separated by a supporting structure to allow the flow of gases or particulates therebetween. In a preferred embodiment, the sensor element components are fused ceramic to resist high temperatures and failure from large temperature changes.

  20. In vitro assembly of catalase.

    Science.gov (United States)

    Baureder, Michael; Barane, Elisabeth; Hederstedt, Lars

    2014-10-10

    Most aerobic organisms contain catalase, which functions to decompose hydrogen peroxide. Typical catalases are structurally complex homo-tetrameric enzymes with one heme prosthetic group buried in each subunit. It is not known how catalase in the cell is assembled from its constituents. The bacterium Enterococcus faecalis cannot synthesize heme but can acquire it from the environment to form a cytoplasmic catalase. We have in E. faecalis monitored production of the enzyme polypeptide (KatA) depending on the availability of heme and used our findings to devise a procedure for the purification of preparative amounts of in vivo-synthesized apocatalase. We show that fully active catalase can be obtained in vitro by incubating isolated apoprotein with hemin. We have characterized features of the assembly process and describe a temperature-trapped hemylated intermediate of the enzyme maturation process. Hemylation of apocatalase does not require auxiliary cell components, but rapid assembly of active enzyme seemingly is assisted in the cell. Our findings provide insight about catalase assembly and offer new experimental possibilities for detailed studies of this process.

  1. Pattern formation in centrosome assembly.

    Science.gov (United States)

    Mahen, Robert; Venkitaraman, Ashok R

    2012-02-01

    A striking but poorly explained feature of cell division is the ability to assemble and maintain organelles not bounded by membranes, from freely diffusing components in the cytosol. This process is driven by information transfer across biological scales such that interactions at the molecular scale allow pattern formation at the scale of the organelle. One important example of such an organelle is the centrosome, which is the main microtubule organising centre in the cell. Centrosomes consist of two centrioles surrounded by a cloud of proteins termed the pericentriolar material (PCM). Profound structural and proteomic transitions occur in the centrosome during specific cell cycle stages, underlying events such as centrosome maturation during mitosis, in which the PCM increases in size and microtubule nucleating capacity. Here we use recent insights into the spatio-temporal behaviour of key regulators of centrosomal maturation, including Polo-like kinase 1, CDK5RAP2 and Aurora-A, to propose a model for the assembly and maintenance of the PCM through the mobility and local interactions of its constituent proteins. We argue that PCM structure emerges as a pattern from decentralised self-organisation through a reaction-diffusion mechanism, with or without an underlying template, rather than being assembled from a central structural template alone. Self-organisation of this kind may have broad implications for the maintenance of mitotic structures, which, like the centrosome, exist stably as supramolecular assemblies on the micron scale, based on molecular interactions at the nanometer scale. PMID:22245706

  2. TWOWS Assembly Convenes in Beijing

    Institute of Scientific and Technical Information of China (English)

    SONG Jianlan

    2010-01-01

    @@ "Women are still under-represented in the fields of science and technology,"remarked HE Naledi Pandor,minister of science and technology of South Africa,at her invited speech heralding the opening of the Fourth General Assembly and International Conference of the Third World Organization for Women in Science(TWOWS)on the morning of June 27 in Beijing.

  3. ATLAS Assembly Hall Open Day

    CERN Multimedia

    Patrice Loiez

    2004-01-01

    To mark the 50th Anniversary of the founding of CERN, a day of tours, displays and presentations was held in October 2004. The assembly halls for the experiments that were waiting to be installed on the LHC, such as ATLAS shown here, were transformed into display areas and cafés.

  4. DESIGN REUSE METHOD FOR ASSEMBLIES IN CONCEPT DESIGN

    Institute of Scientific and Technical Information of China (English)

    Dong Yan; Tan Jianrong; Xu Jing

    2005-01-01

    Aiming at difficult sorting and retrieving complicated structure assemblies in assembly lib,a method for compartmentalizing assembly design resource by conceptual product structure model is presented. The similar assembly retrieval mechanisms of symbol assembly relation graph matching and symbol assembly relation graph similarity are discussed. The method is validated by taking valve rod assemblies as example.

  5. Minimus: a fast, lightweight genome assembler

    Directory of Open Access Journals (Sweden)

    Salzberg Steven L

    2007-02-01

    Full Text Available Abstract Background Genome assemblers have grown very large and complex in response to the need for algorithms to handle the challenges of large whole-genome sequencing projects. Many of the most common uses of assemblers, however, are best served by a simpler type of assembler that requires fewer software components, uses less memory, and is far easier to install and run. Results We have developed the Minimus assembler to address these issues, and tested it on a range of assembly problems. We show that Minimus performs well on several small assembly tasks, including the assembly of viral genomes, individual genes, and BAC clones. In addition, we evaluate Minimus' performance in assembling bacterial genomes in order to assess its suitability as a component of a larger assembly pipeline. We show that, unlike other software currently used for these tasks, Minimus produces significantly fewer assembly errors, at the cost of generating a more fragmented assembly. Conclusion We find that for small genomes and other small assembly tasks, Minimus is faster and far more flexible than existing tools. Due to its small size and modular design Minimus is perfectly suited to be a component of complex assembly pipelines. Minimus is released as an open-source software project and the code is available as part of the AMOS project at Sourceforge.

  6. Hydraulic Experiment for Simulative Assemblies of Blanket Assembly and Np Transmutation Assembly of China Experimental Fast Reactor

    Institute of Scientific and Technical Information of China (English)

    CHENG; Dao-xi; QI; Xiao-guang; ZHAI; Wei-ming; YANG; Bing; ZHOU; Ping

    2013-01-01

    The out-of reactor hydraulic experiment of fast reactor assembly is one of the important experiments in the process of the development of the fast reactor assembly.In this experiment,the size of the throttling element in the foot of the assembly is decided which is fit for the flow division in the reactor and the

  7. Self-assembly of self-assembled molecular triangles

    Indian Academy of Sciences (India)

    Mili C Naranthatta; V Ramkumar; Dillip Kumar Chand

    2014-09-01

    A rare variety of self-assembledmolecular triangle [Pd3(bpy)3(imidazolate)3](NO3)3, 1 is prepared by the combination of Pd(bpy)(NO3)2 with imidazole, at 1:1 ratio, in acetonitrile-water. Deprotonation of imidazole happened during the course of the complexation reaction where upon the metallomacrocycle is formed. The bowl-shaped trinuclear architecture of 1 is crafted with three peripheral bpy units capable of - stacking interactions. While the solution state structure of 1 can be best described as a trinuclear complex, in the solidstate well-fashioned intermolecular - and CH- interactions are observed. Thus, in the solid-state further self-assembly of already self-assembled molecular triangle is witnessed. The triangular panels are arranged in a linear manner utilizing intermolecular - interactions where upon two out of three bpy units of each molecule participated in the chain formation.

  8. Compact MCP assemblies for mass spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Matsuura, S. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.; Umebayashi, S. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.; Kusuyama, Y. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.; Natsume, Y. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.; Oba, K. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.

    1995-09-01

    We have developed compact microchannel plate (MCP) assemblies which have a high gain, good pulse height resolution and a fast response for MS applications. In this paper, these new assemblies are described referring to their structures, functions and characteristics. (orig.).

  9. The Procedure for Assembling the EAST Tokamak

    Institute of Scientific and Technical Information of China (English)

    Wu Songtao

    2005-01-01

    Due to the complicated constitution and high precision requirements of the EAST superconducting tokamak, a meticulous assembling procedure and measurement scheme must be established. The big size and mass of the EAST machine's components and complicated configuration with tight installation tolerances call for a highly careful assembling procedure. The assembling procedure consists of three main sub-procedures for the assembling of the base, of the tori of the VV, the vacuum vessel TS and the TF, and of the peripheral parts respectively. Before the assembly, a reference framework has been set up by means of an industrial measurement system with reference fiducial targets fixed on the wall of the test hall. In this paper, the assembling procedure is described in detail, the survey control system of the assembly is discussed, and progress in the assembly work is also reported.

  10. STAR: a simple TAL effector assembly reaction using isothermal assembly

    Science.gov (United States)

    Gogolok, Sabine; Garcia-Diaz, Claudia; Pollard, Steven M.

    2016-01-01

    Transcription activator-like effectors (TALEs) contain modular programmable DNA binding domains. Fusing TALEs with effector domains creates synthetic transcription factors (TALE-TFs) or nucleases (TALENs), enabling precise gene manipulations. The construction of TALEs remains challenging due to their repetitive sequences. Here we report a simple TALE assembly reaction (STAR) that enables individual laboratories to generate multiple TALEs in a facile manner. STAR uses an isothermal assembly (‘Gibson assembly’) that is labour- and cost-effective, accessible, rapid and scalable. A small 68-part fragment library is employed, and the specific TALE repeat sequence is generated within ~8 hours. Sequence-verified TALENs or TALE-TF plasmids targeting 17 bp target sequences can be produced within three days, without the need for stepwise intermediate plasmid production. We demonstrate the utility of STAR through production of functional TALE-TFs capable of activating human SOX2 expression. STAR addresses some of the shortcomings of existing Golden Gate or solid-phase assembly protocols and enables routine production of TALE-TFs that will complement emerging CRISPR/Cas9-based reagents across diverse applications in mammalian stem cell and synthetic biology. PMID:27615025

  11. United assembly algorithm for optical burst switching

    Institute of Scientific and Technical Information of China (English)

    Jinhui Yu(于金辉); Yijun Yang(杨教军); Yuehua Chen(陈月华); Ge Fan(范戈)

    2003-01-01

    Optical burst switching (OBS) is a promising optical switching technology. The burst assembly algorithm controls burst assembly, which significantly impacts performance of OBS network. This paper provides a new assembly algorithm, united assembly algorithm, which has more practicability than conventional algorithms. In addition, some factors impacting selections of parameters of this algorithm are discussed and the performance of this algorithm is studied by computer simulation.

  12. Virtual Reality and Haptics for Product Assembly

    Directory of Open Access Journals (Sweden)

    Maria Teresa Restivo

    2012-01-01

    Full Text Available Haptics can significantly enhance the user's sense of immersion and interactivity. An industrial application of virtual reality and haptics for product assembly is described in this paper, which provides a new and low-cost approach for product assembly design, assembly task planning and assembly operation training. A demonstration of the system with haptics device interaction was available at the session of exp.at'11.

  13. Hybrid Assembly for Ultra-Precise Manufacturing

    OpenAIRE

    Steinecker, Alexander

    2010-01-01

    International audience This paper presents a European integrated project in the domain of innovative hybrid assembly - the combination of self-assembly and robotics. Robotics allows for high precision and flexibility with full control of the assembly process. Self-assembly, on the other hand, offers massively parallel, unsupervised processing and thus provides high throughputs that cannot be reached with simple robotics alone. The combination of these approaches thus offers robust, high-sp...

  14. Simultaneous Assembly of Multiple Test Forms

    NARCIS (Netherlands)

    Linden, van der Wim J.; Adema, Jos J.

    1998-01-01

    An algorithm for the assembly of multiple test forms is proposed in which the multiple-form problem is reduced to a series of computationally less intensive two-form problems. At each step, one form is assembled to its true specifications; the other form is a dummy assembled only to maintain a balan

  15. 24 CFR 3285.601 - Field assembly.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Field assembly. 3285.601 Section... § 3285.601 Field assembly. Home manufacturers must provide specific installation instructions for the proper field assembly of manufacturer-supplied and shipped loose ducts, plumbing, and fuel supply...

  16. 49 CFR 572.182 - Head assembly.

    Science.gov (United States)

    2010-10-01

    .... The head shall be tested per procedure specified in 49 CFR § 572.112(a). (c) Performance criteria. (1... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.182 Section 572.182... Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the...

  17. 49 CFR 572.184 - Shoulder assembly.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Shoulder assembly. 572.184 Section 572.184... Dummy, 50th Percentile Adult Male § 572.184 Shoulder assembly. (a) The shoulder (175-3000) is part of the body assembly shown in drawing 175-0000. When subjected to impact tests specified in paragraph...

  18. 49 CFR 572.183 - Neck assembly.

    Science.gov (United States)

    2010-10-01

    ... CFR 572.33) at the time the pendulum makes contact with the decelerating mechanism. The velocity-time... 49 Transportation 7 2010-10-01 2010-10-01 false Neck assembly. 572.183 Section 572.183... Dummy, 50th Percentile Adult Male § 572.183 Neck assembly. (a) The neck assembly consists of parts...

  19. Snowball: Strain aware gene assembly of Metagenomes

    NARCIS (Netherlands)

    Gregor, I.; Schoenhuth, A.; McHardy, A.C.

    2015-01-01

    Gene assembly is an important step in functional analysis of shotgun metagenomic data. Nonetheless, strain aware assembly remains a challenging task, as current assembly tools often fail to distinguish among strain variants or require closely related reference genomes of the studied species to be av

  20. Shock buffer for nuclear control assembly

    International Nuclear Information System (INIS)

    A shock buffer is provided for the gradual deceleration of a rapidly descending control element assembly in a nuclear reactor. The interactive buffer components are associated respectively with the movable control element assembly and part of the upper guide structure independent of and spaced from the fuel assemblies of the reactor

  1. LHC Magnet Assembly Facility in building 181

    CERN Multimedia

    CERN Video Productions

    2005-01-01

    Hall 181 activities for the LHC machine * Reception of the American magnets : quadrupoles and separation dipoles * Assembly of the string Low-Beta Triplet -Q2-Q3-DFBX-D1 * Insertion quadrupoles cold masses assembly * Magnets reception type MQM, MQY, MCBC et MCBY * Assembly in the shell * Longitudinal welding under the press * Equipment with end covers in the finishing area

  2. Regenerator cross arm seal assembly

    Science.gov (United States)

    Jackman, Anthony V.

    1988-01-01

    A seal assembly for disposition between a cross arm on a gas turbine engine block and a regenerator disc, the seal assembly including a platform coextensive with the cross arm, a seal and wear layer sealingly and slidingly engaging the regenerator disc, a porous and compliant support layer between the platform and the seal and wear layer porous enough to permit flow of cooling air therethrough and compliant to accommodate relative thermal growth and distortion, a dike between the seal and wear layer and the platform for preventing cross flow through the support layer between engine exhaust and pressurized air passages, and air diversion passages for directing unregenerated pressurized air through the support layer to cool the seal and wear layer and then back into the flow of regenerated pressurized air.

  3. Combinatorial pathway assembly in yeast

    Directory of Open Access Journals (Sweden)

    Khalil Essani

    2015-10-01

    Full Text Available With the emergence of synthetic biology and the vast knowledge about individual biocatalytic reactions, the challenge nowadays is to implement whole natural or synthetic pathways into microorganisms. For this purpose balanced enzyme activities throughout the pathway need to be achieved in addition to simple functional gene expression to avoid bottlenecks and to obtain high titers of the desired product. As the optimization of pathways in a specific biological context is often hard to achieve by rational design, combinatorial approaches have been developed to address this issue. Here, current strategies and proof of concepts for combinatorial pathway assembly in yeasts are reviewed. By exploiting its ability to join multiple DNA fragments in a very efficient and easy manner, the yeast Saccharomyces cerevisiae does not only constitute an attractive host for heterologous pathway expression, but also for assembling pathways by recombination in vivo.

  4. Reversibly assembled cellular composite materials.

    Science.gov (United States)

    Cheung, Kenneth C; Gershenfeld, Neil

    2013-09-13

    We introduce composite materials made by reversibly assembling a three-dimensional lattice of mass-produced carbon fiber-reinforced polymer composite parts with integrated mechanical interlocking connections. The resulting cellular composite materials can respond as an elastic solid with an extremely large measured modulus for an ultralight material (12.3 megapascals at a density of 7.2 milligrams per cubic centimeter). These materials offer a hierarchical decomposition in modeling, with bulk properties that can be predicted from component measurements and deformation modes that can be determined by the placement of part types. Because site locations are locally constrained, structures can be produced in a relative assembly process that merges desirable features of fiber composites, cellular materials, and additive manufacturing.

  5. Multifunctional self-assembled monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Zawodzinski, T.; Bar, G.; Rubin, S.; Uribe, F. [Los Alamos National Lab., NM (United States); Ferrais, J. [Texas Univ., Dallas, TX (United States)

    1996-06-01

    This is the final report of at three year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The specific goals of this research project were threefold: to develop multifunctional self-assembled monolayers, to understand the role of monolayer structure on the functioning of such systems, and to apply this knowledge to the development of electrochemical enzyme sensors. An array of molecules that can be used to attach electrochemically active biomolecules to gold surfaces has been synthesized. Several members of a class of electroactive compounds have been characterized and the factors controlling surface modification are beginning to be characterized. Enzymes have been attached to self-assembled molecules arranged on the gold surface, a critical step toward the ultimate goal of this project. Several alternative enzyme attachment strategies to achieve robust enzyme- modified surfaces have been explored. Several means of juxtaposing enzymes and mediators, electroactive compounds through which the enzyme can exchange electrons with the electrode surface, have also been investigated. Finally, the development of sensitive biosensors based on films loaded with nanoscale-supported gold particles that have surface modified with the self-assembled enzyme and mediator have been explored.

  6. Self-assembled plasmonic metamaterials

    Science.gov (United States)

    Mühlig, Stefan; Cunningham, Alastair; Dintinger, José; Scharf, Toralf; Bürgi, Thomas; Lederer, Falk; Rockstuhl, Carsten

    2013-07-01

    Nowadays for the sake of convenience most plasmonic nanostructures are fabricated by top-down nanofabrication technologies. This offers great degrees of freedom to tailor the geometry with unprecedented precision. However, it often causes disadvantages as well. The structures available are usually planar and periodically arranged. Therefore, bulk plasmonic structures are difficult to fabricate and the periodic arrangement causes undesired effects, e.g., strong spatial dispersion is observed in metamaterials. These limitations can be mitigated by relying on bottom-up nanofabrication technologies. There, self-assembly methods and techniques from the field of colloidal nanochemistry are used to build complex functional unit cells in solution from an ensemble of simple building blocks, i.e., in most cases plasmonic nanoparticles. Achievable structures are characterized by a high degree of nominal order only on a short-range scale. The precise spatial arrangement across larger dimensions is not possible in most cases; leading essentially to amorphous structures. Such self-assembled nanostructures require novel analytical means to describe their properties, innovative designs of functional elements that possess a desired near- and far-field response, and entail genuine nanofabrication and characterization techniques. Eventually, novel applications have to be perceived that are adapted to the specifics of the self-assembled nanostructures. This review shall document recent progress in this field of research. Emphasis is put on bottom-up amorphous metamaterials. We document the state-of-the-art but also critically assess the problems that have to be overcome.

  7. AGORA: Assembly Guided by Optical Restriction Alignment

    Directory of Open Access Journals (Sweden)

    Lin Henry C

    2012-08-01

    Full Text Available Abstract Background Genome assembly is difficult due to repeated sequences within the genome, which create ambiguities and cause the final assembly to be broken up into many separate sequences (contigs. Long range linking information, such as mate-pairs or mapping data, is necessary to help assembly software resolve repeats, thereby leading to a more complete reconstruction of genomes. Prior work has used optical maps for validating assemblies and scaffolding contigs, after an initial assembly has been produced. However, optical maps have not previously been used within the genome assembly process. Here, we use optical map information within the popular de Bruijn graph assembly paradigm to eliminate paths in the de Bruijn graph which are not consistent with the optical map and help determine the correct reconstruction of the genome. Results We developed a new algorithm called AGORA: Assembly Guided by Optical Restriction Alignment. AGORA is the first algorithm to use optical map information directly within the de Bruijn graph framework to help produce an accurate assembly of a genome that is consistent with the optical map information provided. Our simulations on bacterial genomes show that AGORA is effective at producing assemblies closely matching the reference sequences. Additionally, we show that noise in the optical map can have a strong impact on the final assembly quality for some complex genomes, and we also measure how various characteristics of the starting de Bruijn graph may impact the quality of the final assembly. Lastly, we show that a proper choice of restriction enzyme for the optical map may substantially improve the quality of the final assembly. Conclusions Our work shows that optical maps can be used effectively to assemble genomes within the de Bruijn graph assembly framework. Our experiments also provide insights into the characteristics of the mapping data that most affect the performance of our algorithm, indicating the

  8. Robust, directed assembly of fluorescent nanodiamonds

    CERN Document Server

    Kianinia, Mehran; Shimoni, Olga; Randolph, Steven J; Toth, Milos; Aharonovich, Igor; Lobo, Charlene J

    2016-01-01

    Arrays of fluorescent nanoparticles are highly sought after for applications in sensing and nanophotonics. Here we present a simple and robust method of assembling fluorescent nanodiamonds into macroscopic arrays. Remarkably, the yield of this directed assembly process is greater than 90% and the assembled patterns withstand ultra-sonication for more than three hours. The assembly process is based on covalent bonding of carboxyl to amine functional carbon seeds and is applicable to any material, and to non-planar surfaces. Our results pave the way to directed assembly of sensing and nanophotonics devices.

  9. Nuclear fuel assembly identification using computer vision

    International Nuclear Information System (INIS)

    This report describes an improved method of remotely identifying irradiated nuclear fuel assemblies. The method uses existing in-cell TV cameras to input an image of the notch-coded top of the fuel assemblies into a computer vision system, which then produces the identifying number for that assembly. This system replaces systems that use either a mechanical mechanism to feel the notches or use human operators to locate notches visually. The system was developed for identifying fuel assemblies from the Fast Flux Test Facility (FFTF) and the Clinch River Breeder Reactor, but could be used for other reactor assembly identification, as appropriate

  10. Trapping of Hepatitis B Virus capsid assembly intermediates by phenylpropenamide assembly accelerators

    OpenAIRE

    Katen, Sarah P.; Chirapu, Srinivas Reddy; Finn, M.G.; Zlotnick, Adam

    2010-01-01

    Understanding the biological self-assembly process of virus capsids is key to understanding the viral life cycle, as well as serving as a platform for the design of assembly-based antiviral drugs. Here we identify and characterize the phenylpropenamide family of small molecules, known to have antiviral activity in vivo, as assembly effectors of the Hepatitis B Virus (HBV) capsid. We have found two representative phenylpropenamides to be assembly accelerators, increasing the rate of assembly w...

  11. Genome Sequence Databases (Overview): Sequencing and Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, Alla L.

    2009-01-01

    From the date its role in heredity was discovered, DNA has been generating interest among scientists from different fields of knowledge: physicists have studied the three dimensional structure of the DNA molecule, biologists tried to decode the secrets of life hidden within these long molecules, and technologists invent and improve methods of DNA analysis. The analysis of the nucleotide sequence of DNA occupies a special place among the methods developed. Thanks to the variety of sequencing technologies available, the process of decoding the sequence of genomic DNA (or whole genome sequencing) has become robust and inexpensive. Meanwhile the assembly of whole genome sequences remains a challenging task. In addition to the need to assemble millions of DNA fragments of different length (from 35 bp (Solexa) to 800 bp (Sanger)), great interest in analysis of microbial communities (metagenomes) of different complexities raises new problems and pushes some new requirements for sequence assembly tools to the forefront. The genome assembly process can be divided into two steps: draft assembly and assembly improvement (finishing). Despite the fact that automatically performed assembly (or draft assembly) is capable of covering up to 98% of the genome, in most cases, it still contains incorrectly assembled reads. The error rate of the consensus sequence produced at this stage is about 1/2000 bp. A finished genome represents the genome assembly of much higher accuracy (with no gaps or incorrectly assembled areas) and quality ({approx}1 error/10,000 bp), validated through a number of computer and laboratory experiments.

  12. Dynamic pathways for viral capsid assembly

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, Michael F.; Chandler, David

    2006-02-09

    We develop a class of models with which we simulate the assembly of particles into T1 capsid-like objects using Newtonian dynamics. By simulating assembly for many different values of system parameters, we vary the forces that drive assembly. For some ranges of parameters, assembly is facile, while for others, assembly is dynamically frustrated by kinetic traps corresponding to malformed or incompletely formed capsids. Our simulations sample many independent trajectories at various capsomer concentrations, allowing for statistically meaningful conclusions. Depending on subunit (i.e., capsomer) geometries, successful assembly proceeds by several mechanisms involving binding of intermediates of various sizes. We discuss the relationship between these mechanisms and experimental evaluations of capsid assembly processes.

  13. Integrated Virtual Assembly Process Planning System

    Institute of Scientific and Technical Information of China (English)

    LIU Jianhua; HOU Weiwei; HOU Weiwei; SHANG Wei; SHANG Wei; NING Ruxin; NING Ruxin

    2009-01-01

    Assembly process planning(APP) for complicated products is a time-consuming and difficult work with conventional method. Virtual assembly process planning(VAPP) provides engineers a new and efficiency way. Previous studies in VAPP are almost isolated and dispersive, and have not established a whole understanding and discussed key realization techniques of VAPP from a systemic and integrated view. The integrated virtual assembly process planning(IVAPP) system is a new virtual reality based engineering application, which offers engineers an efficient, intuitive, immersive and integrated method for assembly process planning in a virtual environment. Based on analysis the information integration requirement of VAPP, the architecture of IVAPP is proposed. Through the integrated structure, IVAPP system can realize information integration and workflow controlling. In order to model the assembly process in IVAPP, a hierarchical assembly task list(HATL) is presented, in which different assembly tasks for assembling different components are organized into a hierarchical list. A process-oriented automatic geometrical constraint recognition algorithm(AGCR) is proposed, so that geometrical constraints between components can be automatically recognized during the process of interactive assembling. At the same time, a progressive hierarchical reasoning(PHR) model is discussed. AGCR and PHR will greatly reduce the interactive workload. A discrete control node model(DCNM) for cable harness assembly planning in IVAPP is detailed. DCNM converts a cable harness into continuous flexed line segments connected by a series of section center points, and designs can realize cable harness planning through controlling those control nodes. Mechanical assemblies (such as transmission case and engine of automobile) are used to illustrate the feasibility of the proposed method and algorithms. The application of IVAPP system reveals advantages over the traditional assembly process planning method

  14. A self-assembled ionophore

    Science.gov (United States)

    Tirumala, Sampath K.

    1997-11-01

    Ionophores are compounds that bind and transport ions. Ion binding and transport are fundamental to many biological and chemical processes. In this thesis we detail the structural characterization and cation binding properties of a self-assembled ionophore built from an isoguanosine (isoG) derivative, 5sp'-t-butyldimethylsilyl-2sp',3sp'-isopropylidene isoG 30. We begin with a summary of the themes that facilitate ionophore design and the definitions of "self-assembly" and "self-assembled ionophore" in Chapter 1. In Chapter 2, we describe the structural characterization of the isoG 30 self-assembly. IsoG possesses complementary hydrogen bond donor and acceptor sites suitable to form a Csb4-symmetric tetramer, (isoG)sb4 51, that is stable even in high dielectric organic solvents such as CDsb3CN and dsb6-acetone. The isoG tetramer 51 has been characterized by vapor phase osmometry, UV spectroscopy, and by 1D and 2D NMR spectroscopy. The isoG tetramer 51 organizes by hydrogen bonding between the Watson-Crick face of one isoG base and the complementary bottom edge of another purine. The tetramer 51 is stabilized by an inner and outer ring of hydrogen bonds. The inner ring forms between the imino NH1 proton of one monomer and the C2 carbonyl oxygen of an adjacent monomer, while the outer ring is made up of four NH6-N3 hydrogen bonds. The isoG tetramer 51 is thermodynamically stable, with an equilibrium constant (Ksba) of ca. 10sp9-10sp{10} Msp{-3} at room temperature, and a DeltaGsp° of tetramer formation of -12.5 kcal molsp{-1} in dsb6-acetone at 25sp°C. The van't Hoff plots indicated that the thermodynamic parameters for tetramer formation were DeltaHsp° = -18.2 ± 0.87 kcal molsp{-1} and DeltaSsp°sb{298} = -19.1 ± 5.45 eu. In Chapter 3, we describe the cation binding properties of isoG tetramer 51. The isoG tetramer 51 has a central cavity, containing four oxygen atoms, that is suitable for cation coordination. Depending on the cation, the resulting iso

  15. Piston and connecting rod assembly

    Science.gov (United States)

    Brogdon, James William (Inventor); Gill, David Keith (Inventor); Chatten, John K. (Inventor)

    2001-01-01

    A piston and connecting rod assembly includes a piston crown, a piston skirt, a connecting rod, and a bearing insert. The piston skirt is a component separate from the piston crown and is connected to the piston crown to provide a piston body. The bearing insert is a component separate from the piston crown and the piston skirt and is fixedly disposed within the piston body. A bearing surface of a connecting rod contacts the bearing insert to thereby movably associate the connecting rod and the piston body.

  16. Computer-aided lens assembly.

    Science.gov (United States)

    Tomlinson, Richard; Alcock, Rob; Petzing, Jon; Coupland, Jeremy

    2004-01-20

    We propose a computer-aided method of lens manufacture that allows assembly, adjustment, and test phases to be run concurrently until an acceptable level of optical performance is reached. Misalignment of elements within a compound lens is determined by a comparison of the results of physical ray tracing by use of an array of Gaussian laser beams with numerically obtained geometric ray traces. An estimate of misalignment errors is made, and individual elements are adjusted in an iterative manner until performance criteria are achieved. The method is illustrated for the alignment of an air-spaced doublet. PMID:14765916

  17. Chemoselective approaches to glycoprotein assembly

    International Nuclear Information System (INIS)

    Oligosaccharides on proteins and lipids play central roles in human health and disease. The molecular analysis of glycoconjugate function has benefited tremendously from new methods for their chemical synthesis, which provides homogeneous material not attainable from biosynthetic systems. Still, glycoconjugate synthesis requires the manipulation of multiple stereocenters and protecting groups and remains the domain of a few expert laboratories around the world. This account summarizes chemoselective approaches for assembling homogeneous glycoconjugates that attempt to reduce the barriers to their synthesis. The objective of these methods is to make glycoconjugate synthesis accessible to a broader community, thereby accelerating progress in glycobiology

  18. Nanoengineered membrane electrode assembly interface

    Science.gov (United States)

    Song, Yujiang; Shelnutt, John A

    2013-08-06

    A membrane electrode structure suitable for use in a membrane electrode assembly (MEA) that comprises membrane-affixed metal nanoparticles whose formation is controlled by a photochemical process that controls deposition of the metal nanoparticles using a photocatalyst integrated with a polymer electrolyte membrane, such as an ionomer membrane. Impregnation of the polymer membrane with the photocatalyst prior to metal deposition greatly reduces the required amount of metal precursor in the deposition reaction solution by restricting metal reduction substantially to the formation of metal nanoparticles affixed on or near the surface of the polymer membrane with minimal formation of metallic particles not directly associated with the membrane.

  19. PAVE: Program for assembling and viewing ESTs

    Directory of Open Access Journals (Sweden)

    Bomhoff Matthew

    2009-08-01

    Full Text Available Abstract Background New sequencing technologies are rapidly emerging. Many laboratories are simultaneously working with the traditional Sanger ESTs and experimenting with ESTs generated by the 454 Life Science sequencers. Though Sanger ESTs have been used to generate contigs for many years, no program takes full advantage of the 5' and 3' mate-pair information, hence, many tentative transcripts are assembled into two separate contigs. The new 454 technology has the benefit of high-throughput expression profiling, but introduces time and space problems for assembling large contigs. Results The PAVE (Program for Assembling and Viewing ESTs assembler takes advantage of the 5' and 3' mate-pair information by requiring that the mate-pairs be assembled into the same contig and joined by n's if the two sub-contigs do not overlap. It handles the depth of 454 data sets by "burying" similar ESTs during assembly, which retains the expression level information while circumventing time and space problems. PAVE uses MegaBLAST for the clustering step and CAP3 for assembly, however it assembles incrementally to enforce the mate-pair constraint, bury ESTs, and reduce incorrect joins and splits. The PAVE data management system uses a MySQL database to store multiple libraries of ESTs along with their metadata; the management system allows multiple assemblies with variations on libraries and parameters. Analysis routines provide standard annotation for the contigs including a measure of differentially expressed genes across the libraries. A Java viewer program is provided for display and analysis of the results. Our results clearly show the benefit of using the PAVE assembler to explicitly use mate-pair information and bury ESTs for large contigs. Conclusion The PAVE assembler provides a software package for assembling Sanger and/or 454 ESTs. The assembly software, data management software, Java viewer and user's guide are freely available.

  20. Plasma Pyrolysis Assembly Regeneration Evaluation

    Science.gov (United States)

    Medlen, Amber; Abney, Morgan B.; Miller, Lee A.

    2011-01-01

    In April 2010 the Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS). This technology requires hydrogen to recover oxygen from carbon dioxide. This results in the production of water and methane. Water is electrolyzed to provide oxygen to the crew. Methane is vented to space resulting in a loss of valuable hydrogen and unreduced carbon dioxide. This is not critical for ISS because of the water resupply from Earth. However, in order to have enough oxygen for long-term missions, it will be necessary to recover the hydrogen to maximize oxygen recovery. Thus, the Plasma Pyrolysis Assembly (PPA) was designed to recover hydrogen from methane. During operation, the PPA produces small amounts of carbon that can ultimately reduce performance by forming on the walls and windows of the reactor chamber. The carbon must be removed, although mechanical methods are highly inefficient, thus chemical methods are of greater interest. The purpose of this effort was to determine the feasibility of chemically removing the carbon from the walls and windows of a PPA reactor using a pure carbon dioxide stream.

  1. Types for DSP Assembler Programs

    DEFF Research Database (Denmark)

    Larsen, Ken

    2006-01-01

    In this dissertation I present my thesis: A high-level type system is a good aid for developing signal processing programs in handwritten Digital Signal Processor (DSP) assembler code. The problem behind the thesis is that it if often necessary to programing software for embedded systems in assem......In this dissertation I present my thesis: A high-level type system is a good aid for developing signal processing programs in handwritten Digital Signal Processor (DSP) assembler code. The problem behind the thesis is that it if often necessary to programing software for embedded systems...... hearing aids. I present a baseline type system which is the type system of DTAL adapted to Featherweight DSP. I then explain two classes of programs that uncovers some shortcomings of the baseline type systesm. The classes of problematic programs are exemplified by a procedure that initialises an array...... for reuse, and a procedure that computes point-wise vector multiplication. The latter uses a common idiom of prefetching memory resulting in out-of-bounds reading from memory. I present two extensions to the baseline type system: The first extension is a simple modification of some type rules to allow out...

  2. Nanoparticle Assemblies at Fluid Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Thomas P.

    2015-03-10

    A systematic study of the structure and dynamics of nanoparticles (NP) and NP-surfactants was performed. The ligands attached to both the NPs and NP-surfactants dictate the manner in which the nanoscopic materials assemble at fluid interfaces. Studies have shown that a single layer of the nanoscpic materials form at the interface to reduce the interactions between the two immiscible fluids. The shape of the NP is, also, important, where for spherical particles, a disordered, liquid-like monolayer forms, and, for nanorods, ordered domains at the interface is found and, if the monolayers are compressed, the orientation of the nanorods with respect to the interface can change. By associating end-functionalized polymers to the NPs assembled at the interface, NP-surfactants are formed that increase the energetic gain in segregating each NP at the interface which allows the NP-surfactants to jam at the interface when compressed. This has opened the possibility of structuring the two liquids by freezing in shape changes of the liquids.

  3. Dynamic-Model Assembly Line Scheduling

    Directory of Open Access Journals (Sweden)

    Aaima Najam

    2013-07-01

    Full Text Available The assembly line scheduling solution is restricted to two assembly lines that fulfill the requirement of small manufacturing industry by identifying the least cost path. Problem arises when large manufacturing industry comes under discussion where more than two assembly lines say three to fulfill the job, In this case two types of assembly line cost are involve: switching from one assembly line to another; switching from one station to the next. This study considers a solution for above mentioned scenario by least cost path identification, path cost calculation through back tracking, and a derived solution formula in order to reduce the computational complexity of scheduling at latter stages for n station. That provides the understanding for m number of assembly lines at the same time.

  4. Attomolar DNA detection with chiral nanorod assemblies

    OpenAIRE

    Ma, Wei; Kuang, Hua; Xu, Liguang; Ding, Li; Xu, Chuanlai; Wang, Libing; Kotov, Nicholas A.

    2013-01-01

    Nanoscale plasmonic assemblies display exceptionally strong chiral optical activity. So far, their structural design was primarily driven by challenges related to metamaterials whose practical applications are remote. Here we demonstrate that gold nanorods assembled by the polymerase chain reaction into DNA-bridged chiral systems have promising analytical applications. The chiroplasmonic activity of side-by-side assembled patterns is attributed to a 7–9 degree twist between the nanorod axes. ...

  5. Optics assembly for high power laser tools

    Science.gov (United States)

    Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.

    2016-06-07

    There is provided a high power laser rotational optical assembly for use with, or in high power laser tools for performing high power laser operations. In particular, the optical assembly finds applications in performing high power laser operations on, and in, remote and difficult to access locations. The optical assembly has rotational seals and bearing configurations to avoid contamination of the laser beam path and optics.

  6. Control model for reconfigurable assembly systems

    Institute of Scientific and Technical Information of China (English)

    Yu Jianfeng; Yin Yuehong; Chen Zhaoneng

    2005-01-01

    This paper proposes knowledge based object-oriented timed colored Petri net, a modeling method for reconfigurable assembly systems. Combining knowledge and object-oriented method into timed colored Petri net, a comprehensive and powerful representation model for control of RAS is obtained. With object-oriented method the whole system can be decomposed into concrete objects explicitly, and their relationships are constructed according to the system assembly requirements. Finally, a simple assembly system modeled by the KTCOPN is presented.

  7. Morphological Analysis of Forest Tractor Assemblies

    OpenAIRE

    Šušnjar, Marijan; Horvat, Dubravko; Kristić, Andrija; Pandur, Zdravko

    2008-01-01

    The results of this paper present the morphological analysis of nine different types of tractor assemblies used in forestry practice in timber forwarding from thinning operations of lowland forests. Among these tractor assemblies 4 types are older, equipped mechanical cranes. The remaining 5 tractor assemblies, manufactured more recently, are equipped with hydraulic cranes, and two of them are additionally equipped with double-drum winches. According to the research results, older tractor ass...

  8. Design for Un-heterogeneous Critical Assembly

    Institute of Scientific and Technical Information of China (English)

    WANG; Fan; ZHOU; Qi

    2013-01-01

    In order to study the nuclear criticality issues in the dissolving process,a new critical assembly is designed by theoretical calculation to satisfy the heterogeneous critical experimental demands based on the existed YSR assembly(Fig.1).The experiment plans,geometry structure of the assembly,solution contents and fuel rods arrangements are determined.The parameters for each scheme are listed in Table 1.

  9. Efficient synergistic single-cell genome assembly

    Directory of Open Access Journals (Sweden)

    Narjes S. Movahedi

    2016-05-01

    Full Text Available As the vast majority of all microbes are unculturable, single-cell sequencing has become a significant method to gain insight into microbial physiology. Single-cell sequencing methods, currently powered by multiple displacement genome amplification (MDA, have passed important milestones such as finishing and closing the genome of a prokaryote. However, the quality and reliability of genome assemblies from single cells are still unsatisfactory due to uneven coverage depth and the absence of scattered chunks of the genome in the final collection of reads caused by MDA bias. In this work, our new algorithm Hybrid De novo Assembler (HyDA demonstrates the power of co-assembly of multiple single-cell genomic data sets through significant improvement of the assembly quality in terms of predicted functional elements and length statistics. Co-assemblies contain significantly more base pairs and protein coding genes, cover more subsystems, and consist of longer contigs compared to individual assemblies by the same algorithm as well as state-of-the-art single-cell assemblers SPAdes and IDBA-UD. Hybrid emph{De novo} Assembler (HyDA is also able to avoid chimeric assemblies by detecting and separating shared and exclusive pieces of sequence for input data sets. By replacing one deep single-cell sequencing experiment with a few single-cell sequencing experiments of lower depth, the co-assembly method can hedge against the risk of failure and loss of the sample, without significantly increasing sequencing cost. Application of the single-cell co-assembler HyDA to the study of three uncultured members of an alkane-degrading methanogenic community validated the usefulness of the co-assembly concept. HyDA is open source and publicly available at http://chitsazlab.org/software.html and the raw reads are available at http://chitsazlab.org/research.html.

  10. Hierarchical assembly of diphenylalanine into dendritic nanoarchitectures.

    Science.gov (United States)

    Han, Tae Hee; Oh, Jun Kyun; Lee, Gyoung-Ja; Pyun, Su-Il; Kim, Sang Ouk

    2010-09-01

    Highly ordered, multi-dimensional dendritic nanoarchitectures were created via self-assembly of diphenylalanine from an acidic buffer solution. The self-similarity of dendritic structures was characterized by examining their fractal dimensions with the box-counting method. The fractal dimension was determined to be 1.7, which demonstrates the fractal dimension of structures generated by diffusion limited aggregation on a two-dimensional substrate surface. By confining the dendritic assembly of diphenylalanine within PDMS microchannels, the self-similar dendritic growth could be hierarchically directed to create linearly assembled nanoarchitectures. Our approach offers a novel pathway for creating and directing hierarchical nanoarchitecture from biomolecular assembly. PMID:20605423

  11. Self-assembled nanomaterials for photoacoustic imaging

    Science.gov (United States)

    Wang, Lei; Yang, Pei-Pei; Zhao, Xiao-Xiao; Wang, Hao

    2016-01-01

    In recent years, extensive endeavors have been paid to construct functional self-assembled nanomaterials for various applications such as catalysis, separation, energy and biomedicines. To date, different strategies have been developed for preparing nanomaterials with diversified structures and functionalities via fine tuning of self-assembled building blocks. In terms of biomedical applications, bioimaging technologies are urgently calling for high-efficient probes/contrast agents for high-performance bioimaging. Photoacoustic (PA) imaging is an emerging whole-body imaging modality offering high spatial resolution, deep penetration and high contrast in vivo. The self-assembled nanomaterials show high stability in vivo, specific tolerance to sterilization and prolonged half-life stability and desirable targeting properties, which is a kind of promising PA contrast agents for biomedical imaging. Herein, we focus on summarizing recent advances in smart self-assembled nanomaterials with NIR absorption as PA contrast agents for biomedical imaging. According to the preparation strategy of the contrast agents, the self-assembled nanomaterials are categorized into two groups, i.e., the ex situ and in situ self-assembled nanomaterials. The driving forces, assembly modes and regulation of PA properties of self-assembled nanomaterials and their applications for long-term imaging, enzyme activity detection and aggregation-induced retention (AIR) effect for diagnosis and therapy are emphasized. Finally, we conclude with an outlook towards future developments of self-assembled nanomaterials for PA imaging.

  12. Metagenomic Assembly: Overview, Challenges and Applications

    Science.gov (United States)

    Ghurye, Jay S.; Cepeda-Espinoza, Victoria; Pop, Mihai

    2016-01-01

    Advances in sequencing technologies have led to the increased use of high throughput sequencing in characterizing the microbial communities associated with our bodies and our environment. Critical to the analysis of the resulting data are sequence assembly algorithms able to reconstruct genes and organisms from complex mixtures. Metagenomic assembly involves new computational challenges due to the specific characteristics of the metagenomic data. In this survey, we focus on major algorithmic approaches for genome and metagenome assembly, and discuss the new challenges and opportunities afforded by this new field. We also review several applications of metagenome assembly in addressing interesting biological problems. PMID:27698619

  13. Ultrasound transducer assembly and method for manufacturing an ultrasound transducer assembly

    NARCIS (Netherlands)

    Dekker, R.; Henneken, V.A.; Louwerse, M.C.; Raganato, M.F.

    2015-01-01

    The present invention relates to an ultrasound transducer assembly (10), in particular for intravascular ultrasound systems. The ultrasound transducer assembly comprises at least one silicon substrate element (30) including an ultrasound transducer element (14) for emitting and receiving ultrasound

  14. Low inductance power electronics assembly

    Science.gov (United States)

    Herron, Nicholas Hayden; Mann, Brooks S.; Korich, Mark D.; Chou, Cindy; Tang, David; Carlson, Douglas S.; Barry, Alan L.

    2012-10-02

    A power electronics assembly is provided. A first support member includes a first plurality of conductors. A first plurality of power switching devices are coupled to the first support member. A first capacitor is coupled to the first support member. A second support member includes a second plurality of conductors. A second plurality of power switching devices are coupled to the second support member. A second capacitor is coupled to the second support member. The first and second pluralities of conductors, the first and second pluralities of power switching devices, and the first and second capacitors are electrically connected such that the first plurality of power switching devices is connected in parallel with the first capacitor and the second capacitor and the second plurality of power switching devices is connected in parallel with the second capacitor and the first capacitor.

  15. Reconfigurable optical assembly of nanostructures.

    Science.gov (United States)

    Montelongo, Yunuen; Yetisen, Ali K; Butt, Haider; Yun, Seok-Hyun

    2016-01-01

    Arrangements of nanostructures in well-defined patterns are the basis of photonic crystals, metamaterials and holograms. Furthermore, rewritable optical materials can be achieved by dynamically manipulating nanoassemblies. Here we demonstrate a mechanism to configure plasmonic nanoparticles (NPs) in polymer media using nanosecond laser pulses. The mechanism relies on optical forces produced by the interference of laser beams, which allow NPs to migrate to lower-energy configurations. The resulting NP arrangements are stable without any external energy source, but erasable and rewritable by additional recording pulses. We demonstrate reconfigurable optical elements including multilayer Bragg diffraction gratings, volumetric photonic crystals and lenses, as well as dynamic holograms of three-dimensional virtual objects. We aim to expand the applications of optical forces, which have been mostly restricted to optical tweezers. Holographic assemblies of nanoparticles will allow a new generation of programmable composites for tunable metamaterials, data storage devices, sensors and displays. PMID:27337216

  16. Dual contact pogo pin assembly

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, Stephen McGarry

    2016-06-21

    A contact assembly includes a base and a pair of electrical contacts supported by the base. A first end of the first electrical contact corresponds to a first end of the base and is configured to engage a first external conductive circuit element. A first end of the second electrical contact also corresponds to the first end of the base and is configured to engage a second external conductive circuit element. The first contact and the second contact are electrically isolated from one another and configured to compress when engaging an external connector element. The base includes an aperture positioned on a second end of the base outboard of a second end of the first and second electrical contacts. The aperture presents a narrowing shape with a wide mouth distal the electrical contacts and a narrow internal through-hole proximate the electrical contacts.

  17. Reconfigurable optical assembly of nanostructures

    Science.gov (United States)

    Montelongo, Yunuen; Yetisen, Ali K.; Butt, Haider; Yun, Seok-Hyun

    2016-01-01

    Arrangements of nanostructures in well-defined patterns are the basis of photonic crystals, metamaterials and holograms. Furthermore, rewritable optical materials can be achieved by dynamically manipulating nanoassemblies. Here we demonstrate a mechanism to configure plasmonic nanoparticles (NPs) in polymer media using nanosecond laser pulses. The mechanism relies on optical forces produced by the interference of laser beams, which allow NPs to migrate to lower-energy configurations. The resulting NP arrangements are stable without any external energy source, but erasable and rewritable by additional recording pulses. We demonstrate reconfigurable optical elements including multilayer Bragg diffraction gratings, volumetric photonic crystals and lenses, as well as dynamic holograms of three-dimensional virtual objects. We aim to expand the applications of optical forces, which have been mostly restricted to optical tweezers. Holographic assemblies of nanoparticles will allow a new generation of programmable composites for tunable metamaterials, data storage devices, sensors and displays. PMID:27337216

  18. Nanocrystal assembly for tandem catalysis

    Science.gov (United States)

    Yang, Peidong; Somorjai, Gabor; Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu

    2014-10-14

    The present invention provides a nanocrystal tandem catalyst comprising at least two metal-metal oxide interfaces for the catalysis of sequential reactions. One embodiment utilizes a nanocrystal bilayer structure formed by assembling sub-10 nm platinum and cerium oxide nanocube monolayers on a silica substrate. The two distinct metal-metal oxide interfaces, CeO.sub.2--Pt and Pt--SiO.sub.2, can be used to catalyze two distinct sequential reactions. The CeO.sub.2--Pt interface catalyzed methanol decomposition to produce CO and H.sub.2, which were then subsequently used for ethylene hydroformylation catalyzed by the nearby Pt--SiO.sub.2 interface. Consequently, propanal was selectively produced on this nanocrystal bilayer tandem catalyst.

  19. The APOLLO assembly spectrum code

    International Nuclear Information System (INIS)

    The APOLLO code was originally developed as a design tool for HTR's, later it was aimed at the calculation of PWR lattices. APOLLO is a general purpose assembly spectrum code based on the multigroup integral transport equation; refined collision probability modules allow the computation of 1D geometries with linearly anisotropic scattering and two term flux expansion. In 2D geometries modules based on the substructure method provide fast and accurate design calculations and a module based on a direct discretization is devoted to reference calculations. The SPH homogenization technique provides corrected cross sections performing an equivalence between coarse and refined calculations. The post processing module of APOLLO generate either APOLLIB to be used by APOLLO or NEPLIB for reactor diffusion calculation. The cross section library of APOLLO contains data and self-shielding data for more than 400 isotopes. APOLLO is able to compute the depletion of any medium accounting for any heavy isotope or fission product chain. 21 refs

  20. Photonic-powered cable assembly

    Science.gov (United States)

    Sanderson, Stephen N.; Appel, Titus James; Wrye, IV, Walter C.

    2013-01-22

    A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

  1. Self assembly of interlocked architectures

    CERN Document Server

    Schergna, S

    2002-01-01

    An area of great interest is the synthesis and characterisation of molecules possessing moving parts, with the goal that they can act as 'molecular machine' carrying out tasks that molecules with fixed conventional architectures cannot do. Rotaxanes and catenanes (mechanically interlocked architectures) represent one approach toward achieving these aims as their component wheels and / or threads are connected together but can still move, in certain, controlled directions. This thesis focused on the study of structural rigidity and the preorganisation of thread binding sites as factors of major influence on template efficiency in the synthesis of hydrogen bond assembled supramolecular structures (rotaxanes and catenanes). Chapter One gives a brief outline of the common synthetic approaches to interlocked architectures (catenanes and rotaxanes) that are now being developed to address the problems outlined above. Chapter Two and Chapter Three concerns the synthesis of novel amide-based rotaxanes containing vario...

  2. Reconfigurable optical assembly of nanostructures

    Science.gov (United States)

    Montelongo, Yunuen; Yetisen, Ali K.; Butt, Haider; Yun, Seok-Hyun

    2016-06-01

    Arrangements of nanostructures in well-defined patterns are the basis of photonic crystals, metamaterials and holograms. Furthermore, rewritable optical materials can be achieved by dynamically manipulating nanoassemblies. Here we demonstrate a mechanism to configure plasmonic nanoparticles (NPs) in polymer media using nanosecond laser pulses. The mechanism relies on optical forces produced by the interference of laser beams, which allow NPs to migrate to lower-energy configurations. The resulting NP arrangements are stable without any external energy source, but erasable and rewritable by additional recording pulses. We demonstrate reconfigurable optical elements including multilayer Bragg diffraction gratings, volumetric photonic crystals and lenses, as well as dynamic holograms of three-dimensional virtual objects. We aim to expand the applications of optical forces, which have been mostly restricted to optical tweezers. Holographic assemblies of nanoparticles will allow a new generation of programmable composites for tunable metamaterials, data storage devices, sensors and displays.

  3. Snubber assembly for turbine blades

    Science.gov (United States)

    Marra, John J

    2013-09-03

    A snubber associated with a rotatable turbine blade in a turbine engine, the turbine blade including a pressure sidewall and a suction sidewall opposed from the pressure wall. The snubber assembly includes a first snubber structure associated with the pressure sidewall of the turbine blade, a second snubber structure associated with the suction sidewall of the turbine blade, and a support structure. The support structure extends through the blade and is rigidly coupled at a first end portion thereof to the first snubber structure and at a second end portion thereof to the second snubber structure. Centrifugal loads exerted by the first and second snubber structures caused by rotation thereof during operation of the engine are at least partially transferred to the support structure, such that centrifugal loads exerted on the pressure and suctions sidewalls of the turbine blade by the first and second snubber structures are reduced.

  4. Product-internal assembly functions: a novel micro-assembly concept applied to optical interconnects

    OpenAIRE

    Henneken, V.A.

    2008-01-01

    In this project, the technical feasibility of a novel assembly concept was explored, in which microsystem-based self-assembly functionality is added to an existing product. The case considered is the accurate alignment of an optical fibre relative to a telecommunication laser source. In the most demanding cases this requires alignment accuracies down to 0.1 µm to achieve adequate optical coupling. This is very difficult to achieve using conventional assembly, making the assembly cost up ...

  5. Unification of the a priori inconsistencies checking among assembly constraints in assembly sequence planning.

    OpenAIRE

    Perrard, Christophe; Bonjour, Eric

    2013-01-01

    International audience Sequence planning generation is an important problem in assembly line design. A good assembly sequence can help to reduce the cost and time of the manufacturing process. This paper focuses on assembly sequence planning (ASP) known as a hard combinatorial optimization problem. Although the ASP problem has been tackled via even more sophisticated optimization techniques, these techniques are often inefficient for proposing feasible assembly sequences that satisfy the a...

  6. Self-assembly of azide containing dipeptides.

    Science.gov (United States)

    Yuran, Sivan; Razvag, Yair; Das, Priyadip; Reches, Meital

    2014-07-01

    Functional structures and materials are formed spontaneously in nature through the process of self-assembly. Mimicking this process in vitro will lead to the formation of new substances that would impact many areas including energy production and storage, biomaterials and implants, and drug delivery. The considerable structural diversity of peptides makes them appealing building blocks for self-assembly in vitro. This paper describes the self-assembly of three aromatic dipeptides containing an azide moiety: H-Phe(4-azido)-Phe(4-azido)-OH, H-Phe(4-azido)-Phe-OH, and H-Phe-Phe(4-azido)-OH. The peptide H-Phe(4-azido)-Phe(4-azido)-OH self-assembled into porous spherical structures, whereas the peptides H-Phe(4-azido)-Phe-OH and H-Phe-Phe(4-azido)-OH did not form any ordered structures under the examined experimental conditions. The azido group of the peptide can serve as a photo cross-linking agent upon irradiation with UV light. To examine the effect of this group and its activity on the self-assembled structures, we irradiated the assemblies in solution for different time periods. Using electron microscopy, we determined that the porous spherical assemblies formed by the peptide H-Phe(4-azido)-Phe(4-azido)-OH underwent a structural change upon irradiation. In addition, using FT-IR, we detected the chemical change of the peptide azido group. Moreover, using indentation experiments with atomic force microscopy, we showed that the Young's modulus of the spherical assemblies increased after 20 min of irradiation with UV light. Overall, irradiating the solution of the peptide assemblies containing the azido group resulted in a change both in the morphology and mechanical properties of the peptide-based structures. These ordered assemblies or their peptide monomer building blocks can potentially be incorporated into other peptide assemblies to generate stiffer and more stable materials. PMID:24889029

  7. MetaVelvet-SL: an extension of the Velvet assembler to a de novo metagenomic assembler utilizing supervised learning

    OpenAIRE

    , Afiahayati; Sato, Kengo; Sakakibara, Yasubumi

    2014-01-01

    The assembly of multiple genomes from mixed sequence reads is a bottleneck in metagenomic analysis. A single-genome assembly program (assembler) is not capable of resolving metagenome sequences, so assemblers designed specifically for metagenomics have been developed. MetaVelvet is an extension of the single-genome assembler Velvet. It has been proved to generate assemblies with higher N50 scores and higher quality than single-genome assemblers such as Velvet and SOAPdenovo when applied to me...

  8. Formal Verification of Self-Assembling Systems

    CERN Document Server

    Sterling, Aaron

    2010-01-01

    This paper introduces the theory and practice of formal verification of self-assembling systems. We interpret a well-studied abstraction of nanomolecular self assembly, the Abstract Tile Assembly Model (aTAM), into Computation Tree Logic (CTL), a temporal logic often used in model checking. We then consider the class of "rectilinear" tile assembly systems. This class includes most aTAM systems studied in the theoretical literature, and all (algorithmic) DNA tile self-assembling systems that have been realized in laboratories to date. We present a polynomial-time algorithm that, given a tile assembly system T as input, either provides a counterexample to T's rectilinearity or verifies whether T has a unique terminal assembly. Using partial order reductions, the verification search space for this algorithm is reduced from exponential size to O(n^2), where n x n is the size of the assembly surface. That reduction is asymptotically the best possible. We report on experimental results obtained by translating tile ...

  9. Uracil Excision for Assembly of Complex Pathways

    DEFF Research Database (Denmark)

    Cavaleiro, Mafalda; Nielsen, Morten Thrane; Kim, Se Hyeuk;

    2015-01-01

    Despite decreasing prices on synthetic DNA constructs, higher-order assembly of PCR-generated DNA continues to be an important exercise in molecular and synthetic biology. Simplicity and robustness are attractive features met by the uracil excision DNA assembly method, which is one of the most in...

  10. Assembly of the CMS hadronic calorimeter

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The hadronic calorimeter is assembled on the end-cap of the CMS detector in the assembly hall. Hadronic calorimeters measure the energy of particles that interact via the strong force, called hadrons. The detectors are made in a sandwich-like structure where these scintillator tiles are placed between metal sheets.

  11. Preliminary High-Throughput Metagenome Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Dusheyko, Serge; Furman, Craig; Pangilinan, Jasmyn; Shapiro, Harris; Tu, Hank

    2007-03-26

    Metagenome data sets present a qualitatively different assembly problem than traditional single-organism whole-genome shotgun (WGS) assembly. The unique aspects of such projects include the presence of a potentially large number of distinct organisms and their representation in the data set at widely different fractions. In addition, multiple closely related strains could be present, which would be difficult to assemble separately. Failure to take these issues into account can result in poor assemblies that either jumble together different strains or which fail to yield useful results. The DOE Joint Genome Institute has sequenced a number of metagenomic projects and plans to considerably increase this number in the coming year. As a result, the JGI has a need for high-throughput tools and techniques for handling metagenome projects. We present the techniques developed to handle metagenome assemblies in a high-throughput environment. This includes a streamlined assembly wrapper, based on the JGI?s in-house WGS assembler, Jazz. It also includes the selection of sensible defaults targeted for metagenome data sets, as well as quality control automation for cleaning up the raw results. While analysis is ongoing, we will discuss preliminary assessments of the quality of the assembly results (http://fames.jgi-psf.org).

  12. 49 CFR 570.63 - Wheel assemblies.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Wheel assemblies. 570.63 Section 570.63 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... 10,000 Pounds § 570.63 Wheel assemblies. (a) Wheel integrity. A tire rim, wheel disc or spider...

  13. Fibril assembly in whey protein mixtures

    NARCIS (Netherlands)

    Bolder, S.G.

    2007-01-01

    The objective of this thesis was to study fibril assembly in mixtures of whey proteins. The effect of the composition of the protein mixture on the structures and the resulting phase behaviour was investigated. The current work has shown that beta-lactoglobulin is responsible for the fibril assembly

  14. Microfabricated field calibration assembly for analytical instruments

    Science.gov (United States)

    Robinson, Alex L.; Manginell, Ronald P.; Moorman, Matthew W.; Rodacy, Philip J.; Simonson, Robert J.

    2011-03-29

    A microfabricated field calibration assembly for use in calibrating analytical instruments and sensor systems. The assembly comprises a circuit board comprising one or more resistively heatable microbridge elements, an interface device that enables addressable heating of the microbridge elements, and, in some embodiments, a means for positioning the circuit board within an inlet structure of an analytical instrument or sensor system.

  15. Aerodynamic seal assemblies for turbo-machinery

    Energy Technology Data Exchange (ETDEWEB)

    Bidkar, Rahul Anil; Wolfe, Christopher; Fang, Biao

    2015-09-29

    The present application provides an aerodynamic seal assembly for use with a turbo-machine. The aerodynamic seal assembly may include a number of springs, a shoe connected to the springs, and a secondary seal positioned about the springs and the shoe.

  16. Self-assembled nanogaps for molecular electronics

    DEFF Research Database (Denmark)

    Tang, Qingxin; Tong, Yanhong; Jain, Titoo;

    2009-01-01

    A nanogap for molecular devices was realized using solution-based self-assembly. Gold nanorods were assembled to gold nanoparticle-coated conducting SnO2:Sb nanowires via thiol end-capped oligo(phenylenevinylene)s (OPVs). The molecular gap was easily created by the rigid molecule itself during se...

  17. 49 CFR 572.192 - Head assembly.

    Science.gov (United States)

    2010-10-01

    ... CFR 572.112(a). (c) Performance criteria. (1) When the head assembly is dropped from either the right...) and a set of three (3) accelerometers in conformance with specifications in 49 CFR 572.200(d) and... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.192 Section...

  18. Space Science Assembly Convenes in Beijing

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The opening ceremony for the 36th Scientific Assembly of the Committee on Space Research (COSPAR) was held on the evening of July 17 in Beijing. Chinese President HU Jintao sent his congratulations to the assembly. Chinese Vice Premier ZENG Peiyan spoke at the opening ceremony.

  19. Encoding network states by striatal cell assemblies.

    Science.gov (United States)

    Carrillo-Reid, Luis; Tecuapetla, Fatuel; Tapia, Dagoberto; Hernández-Cruz, Arturo; Galarraga, Elvira; Drucker-Colin, René; Bargas, José

    2008-03-01

    Correlated activity in cortico-basal ganglia circuits plays a key role in the encoding of movement, associative learning and procedural memory. How correlated activity is assembled by striatal microcircuits is not understood. Calcium imaging of striatal neuronal populations, with single-cell resolution, reveals sporadic and asynchronous activity under control conditions. However, N-methyl-d-aspartate (NMDA) application induces bistability and correlated activity in striatal neurons. Widespread neurons within the field of observation present burst firing. Sets of neurons exhibit episodes of recurrent and synchronized bursting. Dimensionality reduction of network dynamics reveals functional states defined by cell assemblies that alternate their activity and display spatiotemporal pattern generation. Recurrent synchronous activity travels from one cell assembly to the other often returning to the original assembly; suggesting a robust structure. An initial search into the factors that sustain correlated activity of neuronal assemblies showed a critical dependence on both intrinsic and synaptic mechanisms: blockage of fast glutamatergic transmission annihilates all correlated firing, whereas blockage of GABAergic transmission locked the network into a single dominant state that eliminates assembly diversity. Reduction of L-type Ca(2+)-current restrains synchronization. Each cell assembly comprised different cells, but a small set of neurons was shared by different assemblies. A great proportion of the shared neurons was local interneurons with pacemaking properties. The network dynamics set into action by NMDA in the striatal network may reveal important properties of striatal microcircuits under normal and pathological conditions. PMID:18184883

  20. Some Questions about Feature Re-Assembly

    Science.gov (United States)

    White, Lydia

    2009-01-01

    In this commentary, differences between feature re-assembly and feature selection are discussed. Lardiere's proposals are compared to existing approaches to grammatical features in second language (L2) acquisition. Questions are raised about the predictive power of the feature re-assembly approach. (Contains 1 footnote.)

  1. Conducting Assemblies in Botswana Public Schools

    Science.gov (United States)

    Baamphatlha, Dinama

    2011-01-01

    In this paper, the author explored the teachers' experiences and their views regarding how assemblies are conducted in Botswana public schools. The author indicates that assemblies are a common feature in Botswana primary and secondary schools. The author adopted the Christian Privilege as the conceptual framework as espoused by Blumenfeld (2006)…

  2. On optimization of interference fit assembly

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2016-01-01

    Assembly of shaft and hub by an interference fitis a classical connection with known advantages and disadvantages.The advantage being the level of possible torque transfer while the disadvantage is a possible fretting fatigue failure at the points of stress concentration. To improve the assembly ...

  3. ATLAS: End-cap Toroid assembly

    CERN Multimedia

    2006-01-01

    In building 191 and building 180- assembly of this massive piece.To reach the top of the end-cap the cranes has to be used and during the assembly you can see welding and hear many tools running background.

  4. MTI Focal Plane Assembly Design and Performance

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, M.; Rienstra, J.L.

    1999-06-17

    The focal plane assembly for the Multispectral Thermal Imager (MTI) consists of sensor chip assemblies, optical filters, and a vacuum enclosure. Sensor chip assemblies, composed of linear detector arrays and readout integrated circuits, provide spatial resolution in the cross-track direction for the pushbroom imager. Optical filters define 15 spectral bands in a range from 0.45 {micro}m to 10.7 {micro}m. All the detector arrays are mounted on a single focal plane and are designed to operate at 75 K. Three pairs of sensor chip assemblies (SCAs) are required to provide cross-track coverage in all 15 spectral bands. Each pair of SCAs includes detector arrays made from silicon, iridium antimonide, and mercury cadmium telluride. Read out integrated circuits multiplex the signals from the detectors to 18 separate video channels. Optical filter assemblies defining the spectral bands are mounted over the linear detector arrays. Each filter assembly consists of several filter strips bonded together side-by-side. The MTI focal plane assembly has been integrated with the rest of the payload and has undergone detailed testing and calibration. This paper includes representative test data for the various spectral bands and the overall performance of the focal plane assembly.

  5. Assembly jig assures reliable solar cell modules

    Science.gov (United States)

    Ofarrell, H. O.

    1966-01-01

    Assembly jig holds the components for a solar cell module in place as the assembly is soldered and bonded by the even heat of an oven. The jig is designed to the configuration of the planned module. It eliminates uneven thermal conditions caused by hand soldering methods.

  6. CT Performance Evaluation Using Multi Material Assemblies

    DEFF Research Database (Denmark)

    Stolfi, Alessandro; De Chiffre, Leonardo

    2015-01-01

    This paper concerns an investigation of the accuracy of Computed Tomography measurements using multi-material assemblies. In this study, assemblies involving similar densities for elementary parts were considered. The investigation includes dimensional and geometrical measurements of two 10 mm high...

  7. Hydrodynamically driven colloidal assembly in dip coating.

    Science.gov (United States)

    Colosqui, Carlos E; Morris, Jeffrey F; Stone, Howard A

    2013-05-01

    We study the hydrodynamics of dip coating from a suspension and report a mechanism for colloidal assembly and pattern formation on smooth substrates. Below a critical withdrawal speed where the coating film is thinner than the particle diameter, capillary forces induced by deformation of the free surface prevent the convective transport of single particles through the meniscus beneath the film. Capillary-induced forces are balanced by hydrodynamic drag only after a minimum number of particles assemble within the meniscus. The particle assembly can thus enter the thin film where it moves at nearly the withdrawal speed and rapidly separates from the next assembly. The interplay between hydrodynamic and capillary forces produces periodic and regular structures below a critical ratio Ca(2/3)/sqrt[Bo] particles in suspension. The hydrodynamically driven assembly documented here is consistent with stripe pattern formations observed experimentally in dip coating.

  8. Human Contamination in Public Genome Assemblies.

    Science.gov (United States)

    Kryukov, Kirill; Imanishi, Tadashi

    2016-01-01

    Contamination in genome assembly can lead to wrong or confusing results when using such genome as reference in sequence comparison. Although bacterial contamination is well known, the problem of human-originated contamination received little attention. In this study we surveyed 45,735 available genome assemblies for evidence of human contamination. We used lineage specificity to distinguish between contamination and conservation. We found that 154 genome assemblies contain fragments that with high confidence originate as contamination from human DNA. Majority of contaminating human sequences were present in the reference human genome assembly for over a decade. We recommend that existing contaminated genomes should be revised to remove contaminated sequence, and that new assemblies should be thoroughly checked for presence of human DNA before submitting them to public databases. PMID:27611326

  9. Hapsembler: An Assembler for Highly Polymorphic Genomes

    Science.gov (United States)

    Donmez, Nilgun; Brudno, Michael

    As whole genome sequencing has become a routine biological experiment, algorithms for assembly of whole genome shotgun data has become a topic of extensive research, with a plethora of off-the-shelf methods that can reconstruct the genomes of many organisms. Simultaneously, several recently sequenced genomes exhibit very high polymorphism rates. For these organisms genome assembly remains a challenge as most assemblers are unable to handle highly divergent haplotypes in a single individual. In this paper we describe Hapsembler, an assembler for highly polymorphic genomes, which makes use of paired reads. Our experiments show that Hapsembler produces accurate and contiguous assemblies of highly polymorphic genomes, while performing on par with the leading tools on haploid genomes. Hapsembler is available for download at http://compbio.cs.toronto.edu/hapsembler.

  10. Human Contamination in Public Genome Assemblies

    Science.gov (United States)

    Kryukov, Kirill; Imanishi, Tadashi

    2016-01-01

    Contamination in genome assembly can lead to wrong or confusing results when using such genome as reference in sequence comparison. Although bacterial contamination is well known, the problem of human-originated contamination received little attention. In this study we surveyed 45,735 available genome assemblies for evidence of human contamination. We used lineage specificity to distinguish between contamination and conservation. We found that 154 genome assemblies contain fragments that with high confidence originate as contamination from human DNA. Majority of contaminating human sequences were present in the reference human genome assembly for over a decade. We recommend that existing contaminated genomes should be revised to remove contaminated sequence, and that new assemblies should be thoroughly checked for presence of human DNA before submitting them to public databases. PMID:27611326

  11. Controlling and imaging biomimetic self-assembly

    Science.gov (United States)

    Aliprandi, Alessandro; Mauro, Matteo; de Cola, Luisa

    2016-01-01

    The self-assembly of chemical entities represents a very attractive way to create a large variety of ordered functional structures and complex matter. Although much effort has been devoted to the preparation of supramolecular nanostructures based on different chemical building blocks, an understanding of the mechanisms at play and the ability to monitor assembly processes and, in turn, control them are often elusive, which precludes a deep and comprehensive control of the final structures. Here the complex supramolecular landscape of a platinum(II) compound is characterized fully and controlled successfully through a combination of supramolecular and photochemical approaches. The supramolecular assemblies comprise two kinetic assemblies and their thermodynamic counterpart. The monitoring of the different emission properties of the aggregates, used as a fingerprint for each species, allows the real-time visualization of the evolving self-assemblies. The control of multiple supramolecular pathways will help the design of complex systems in and out of their thermodynamic equilibrium.

  12. Forwardly movable assembly for a firearm

    Science.gov (United States)

    Crandall, David L.; Watson, Richard W.

    2007-06-05

    A forwardly movable assembly for a firearm, the forwardly movable assembly adapted to be disposed in operative relationship relative to the other operative parts of a firearm, the firearm having in operative relationship each with one or more of the others: a barrel, a receiver, and at least one firing mechanism; the forwardly movable assembly comprising: the barrel and the receiver operatively connected with each other; a movable hand support structure to which at least one of the barrel and the receiver is connected, the barrel being movable therewith, the movable hand support structure being adapted to be gripped by an operator of the firearm; the forwardly movable assembly being adapted to be moved forward by an operator upon gripping the movable hand support structure and manually maneuvering the hand support structure forwardly; and, as the forwardly movable assembly is moved forwardly, the firing mechanism is completely disengaged therefrom and held substantially stationary relative thereto.

  13. Modular fuel-cell stack assembly

    Science.gov (United States)

    Patel, Pinakin

    2010-07-13

    A fuel cell assembly having a plurality of fuel cells arranged in a stack. An end plate assembly abuts the fuel cell at an end of said stack. The end plate assembly has an inlet area adapted to receive an exhaust gas from the stack, an outlet area and a passage connecting the inlet area and outlet area and adapted to carry the exhaust gas received at the inlet area from the inlet area to the outlet area. A further end plate assembly abuts the fuel cell at a further opposing end of the stack. The further end plate assembly has a further inlet area adapted to receive a further exhaust gas from the stack, a further outlet area and a further passage connecting the further inlet area and further outlet area and adapted to carry the further exhaust gas received at the further inlet area from the further inlet area to the further outlet area.

  14. Cable Harness Assembly Planning in Virtual Environment

    Institute of Scientific and Technical Information of China (English)

    LIU Jianhua; NING Ruxin; BAI Shuqing; WANG Bile

    2006-01-01

    Based on the analysis of characteristic of cable harness planning in virtual environment, a discrete control node modeling (DCNM) method of cable harness in virtual environment and the cable harness assembly routing technique based on it are proposed. DCNM converts a cable harness into continuous flexed line segments connected by a series of section center points, and the design can realize cable harness planning through controlling those control nodes. This method of cable harness routing in the virtual environment breaks the status that virtual assembly process planning is just suitable for the rigid components at present, and impulse the virtual assembly process planning to be more practical. Relation algorithms have been verified in a self-developed system named virtual cable harness assembly planning (VCHAP) system, and this VCHAP system has been applied in assembly process planning of aerospace-related products.

  15. Classification of assembly techniques for micro products

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Tosello, Guido; Gegeckaite, Asta;

    2005-01-01

    Industrial production of micro products to be introduced in the market has to be reliable, fast, carried out at a reasonable price and in an acceptable quantity. One of the crucial steps in the process chain related to micro product manufacture is the assembly phase. Here components are handled...... and assembled into sub-assemblies or final products. Because of the small size these processes are complex and often difficult to automate. It is therefore important to take into account the possible challenges of assembly already in the product development stage, because here the decisions regarding number....... The methodology furthermore assists the designer in describing possibilities, potentials and limits available when dealing with micro product manufacture involving assembly....

  16. Effects of radial void distribution within fuel assembly on assembly neutronic characteristics

    International Nuclear Information System (INIS)

    The effect of radial subchannel-wise void distribution in a fuel assembly on assembly neutronic characteristics has been investigated using the assembly calculation code SRAC95 and the subchannel analysis code THERMIT2. With the iterative calculation of assembly calculation and the subchannel analysis (Method 1), subchannel-wise void fraction distribution, pin-power distribution and the infinite multiplication factor of the assembly are calculated. The results are compared with the result of the assembly calculation using uniform void distribution as input (Method 2). The calculation is performed for two assembly configurations in the present study: one is a fuel assembly that does not include a water rod (Case 1) and the other is the assembly that includes a water rod (Case 2). The differences in the infinite multiplication factor and pin-power peaking factor between the two methods are small in both cases. In typical BWR fuel assemblies that are investigated in the present study, the method that does not consider the radial subchannel-wise void fraction distribution within a fuel assembly (Method 2) is accurate enough for practical applications. (author)

  17. Tolerance Analysis in Straight-Build Mechanical Assemblies Using a Probabilistic Approach-2D Assembly

    Directory of Open Access Journals (Sweden)

    Tanweer Hussain

    2013-04-01

    Full Text Available Product quality in mechanical assemblies is determined by the dispersion of manufacturing variance during the structure building. This paper focuses on straight-build assembly and proposes a probabilistic approach based on connective assembly model to analyze the effect of individual component variations on the eccentricity of the straight-build assembly. The probabilistic approach calculates the pdf (probability density function of key assembly variation of rotor assembly of high speed rotating machines. The probabilistic approach considers two straight-build scenarios: (i Best Build; and (ii Direct Build, for 2D (Two-Dimensional "axi-symmetric" assemblies. Numerical examples are presented to investigate the probabilistic approach for its efficiency and accuracy in comparison to MCS (Monte Carlo simulation.

  18. Solution assembly of conjugated polymers

    Science.gov (United States)

    Bokel, Felicia A.

    This dissertation focuses on the solution-state polymer assembly of conjugated polymers with specific attention to nano- and molecular-scale morphology. Understanding how to control these structures holds potential for applications in polymer-based electronics. Optimization of conjugated polymer morphology was performed with three objectives: 1) segregation of donor and acceptor materials on the nanometer length-scale, 2) achieving molecular-scale ordering in terms of crystallinity within distinct domains, and 3) maximizing the number and quality of well-defined donor/acceptor interfaces. Chapter 1 introduces the development of a mixed solvent method to create crystalline poly(3-hexyl thiophene) (P3HT) fibrils in solution. Chapter 2 describes fibril purification and approaches to robust and functional fibrils, while chapters 3 and 4 demonstrate the formation of hybrid nanocomposite wires of P3HT and cadmium selenide (CdSe) nanoparticles by two methods: 1) co-crystallization of free and P3HT-grafted CdSe for composite nanowires and 2) direct attachment of CdSe nanoparticles at fibril edges to give superhighway structures. These composite structures show great potential in the application of optoelectronic devices, such as the active layer of solar cells. Finally, ultrafast photophysical characterization of these polymers, using time-resolved photoluminescence and transient absorption, was performed to determine the aggregation types present in suspended fibrils and monitor the formation and decay of charged species in fibrils and donor-acceptor systems.

  19. Combustor bulkhead heat shield assembly

    Energy Technology Data Exchange (ETDEWEB)

    Zeisser, M.H.

    1990-06-19

    This paper describes a gas turbine engine having an annular combustion chamber defined by an annular, inner liner, a concentric outer liner, and an upstream annular combustor head, wherein the head includes a radially extending bulkhead having circumferentially distributed openings for each receiving an individual fuel nozzle therethrough. It comprises: a segmented heat shield assembly, disposed between the combustion chamber interior and the bulkhead, including generally planar, sector shaped heat shields, each shield abutting circumferentially with two next adjacent shields and extending radially from proximate the inner liner to proximate the outer liner, the plurality of shields collectively defining an annular protective barrier, and wherein each sector shaped shield further includes an opening, corresponding to one of the bulkhead nozzle openings for likewise receiving the corresponding nozzle therethrough, the shield opening further including an annular lip extending toward the bulkhead and being received within the bulkhead opening, raised ridges on the shield backside, the ridges contacting the facing bulkhead surface and defining a flow path for a flow of cooling air issuing from a sized supply opening disposed in the bulkhead, the flow path running ultimately from adjacent the annular lip to the edges of each shield segment, wherein the raised edges extend fully along the lateral, circumferentially spaced edges of each shield segment and about the adjacent shield segments wherein the raised ridges further extend circumferentially between the annular lip and the abutting edge ridges.

  20. Halliburton Composite Bridge Plug Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Starbuck, J.M.; Luttrell, C.R.; Aramayo, G.

    2005-01-15

    The overall objectives of this CRADA were to assist Halliburton in analyzing a composite bridge plug and to determine why their original design was failing in the field. In Phase 1, finite element analyses were done on the original composite slip design and several alternative designs. The composite slip was the component in the bridge plug that was failing. The finite element code ABAQUS was used for these calculations and I-DEAS was used as the pre- and post-processor in the analyses. Several different designs and materials were analyzed and recommendations were made towards improving the design. In Phase 2, the objective was to develop finite element models that would accurately represent the deformations in the entire all-composite 4-1/2' diameter bridge plug assembly. The finite element code LS-DYNA was used and the results from this effort were intended to expand Halliburton's composite design and analysis capabilities with regard to developing future composite components for downhole tools. In addition to the finite element modeling, this effort involved the utilization of micromechanics to determine the necessary composite material properties that were needed as input for finite element codes.

  1. Assembly of high voltage devices

    Energy Technology Data Exchange (ETDEWEB)

    Cameroni, R.; Granata, C.; Calamari, L.; Gatti, P. [ABB PTPH U.O. ADDA, Lodi (Italy)

    2008-07-01

    Electric utilities are required to provide high quality power delivery. ABB has developed a new type of switching device that combines a circuit breaker and one or more disconnectors and their control gears. These high voltage switchgear components are based either on air-insulated technology (AIS), or on gas-insulated technology (GIS) or a combination of both. The use of hybrid switchgear has enabled the development of simplified substations with many advantages, such as less space required due to GIS technology; higher flexibility of layout versus AIS; bus reconfiguration for increased system reliability and reduced outages; easier engineering; reduced maintenance and costs; easier integration of secondary systems; fast installation; and easy replacement in case of failure. The life cycle cost of the ABB hybrid modules has been evaluated on the basis of different network configuration scenarios, including indoor and outdoor installations. The International Electrotechnical Commission is preparing a new standard IEC 62271-205 to classify the combination of switching devices as assemblies of high voltage devices. 2 refs., 12 figs.

  2. Flashback resistant pre-mixer assembly

    Science.gov (United States)

    Laster, Walter R.; Gambacorta, Domenico

    2012-02-14

    A pre-mixer assembly associated with a fuel supply system for mixing of air and fuel upstream from a main combustion zone in a gas turbine engine. The pre-mixer assembly includes a swirler assembly disposed about a fuel injector of the fuel supply system and a pre-mixer transition member. The swirler assembly includes a forward end defining an air inlet and an opposed aft end. The pre-mixer transition member has a forward end affixed to the aft end of the swirler assembly and an opposed aft end defining an outlet of the pre-mixer assembly. The aft end of the pre-mixer transition member is spaced from a base plate such that a gap is formed between the aft end of the pre-mixer transition member and the base plate for permitting a flow of purge air therethrough to increase a velocity of the air/fuel mixture exiting the pre-mixer assembly.

  3. Mechanical Self-Assembly Science and Applications

    CERN Document Server

    2013-01-01

    Mechanical Self-Assembly: Science and Applications introduces a novel category of self-assembly driven by mechanical forces. This book discusses self-assembly in various types of small material structures including thin films, surfaces, and micro- and nano-wires, as well as the practice's potential application in micro and nanoelectronics, MEMS/NEMS, and biomedical engineering. The mechanical self-assembly process is inherently quick, simple, and cost-effective, as well as accessible to a large number of materials, such as curved surfaces for forming three-dimensional small structures. Mechanical self-assembly is complementary to, and sometimes offer advantages over, the traditional micro- and nano-fabrication. This book also: Presents a highly original aspect of the science of self-assembly Describes the novel methods of mechanical assembly used to fabricate a variety of new three-dimensional material structures in simple and cost-effective ways Provides simple insights to a number of biological systems and ...

  4. Self and directed assembly: people and molecules.

    Science.gov (United States)

    James, Tony D

    2016-01-01

    Self-assembly and directed-assembly are two very important aspects of supramolecular chemistry. As a young postgraduate student working in Canada with Tom Fyles my introduction to Supramolecular Chemistry was through the self-assembly of phospholipid membranes to form vesicles for which we were developing unimolecular and self-assembling transporter molecules. The next stage of my development as a scientist was in Japan with Seiji Shinkai where in a "Eureka" moment, the boronic acid templating unit (directed-assembly) of Wulff was combined with photoinduced electron transfer systems pioneered by De Silva. The result was a turn-on fluorescence sensor for saccharides; this simple result has continued to fuel my research to the present day. Throughout my career as well as assembling molecules, I have enjoyed bringing together researchers in order to develop collaborative networks. This is where molecules meet people resulting in assemblies worth more than the individual "molecule" or "researcher". My role in developing networks with Japan was rewarded by the award of a Daiwa-Adrian Prize in 2013 and I was recently rewarded for developing networks with China with an Inaugural CASE Prize in 2015. PMID:27340435

  5. Constraints on Assembly Bias from Galaxy Clustering

    CERN Document Server

    Zentner, Andrew R; Bosch, Frank C van den; Lange, Johannes U; Villarreal, Antonio

    2016-01-01

    We constrain the newly-introduced decorated Halo Occupation Distribution (HOD) model using SDSS DR7 measurements of projected galaxy clustering or r-band luminosity threshold samples. The decorated HOD is a model for the galaxy-halo connection that augments the HOD by allowing for the possibility of galaxy assembly bias: galaxy luminosity may be correlated with dark matter halo properties besides mass, Mvir. We demonstrate that it is not possible to rule out galaxy assembly bias using DR7 measurements of galaxy clustering alone. Moreover, galaxy samples with Mr < -20 and Mr < -20.5 favor strong central galaxy assembly bias. These samples prefer scenarios in which high-concentration are more likely to host a central galaxy relative to low-concentration halos of the same mass. We exclude zero assembly bias with high significance for these samples. Satellite galaxy assembly bias is significant for the faintest sample, Mr < -19. We find no evidence for assembly bias in the Mr < -21 sample. Assembly bi...

  6. Directed Self-Assembly of Nanodispersions

    Energy Technology Data Exchange (ETDEWEB)

    Furst, Eric M [University of Delaware

    2013-11-15

    Directed self-assembly promises to be the technologically and economically optimal approach to industrial-scale nanotechnology, and will enable the realization of inexpensive, reproducible and active nanostructured materials with tailored photonic, transport and mechanical properties. These new nanomaterials will play a critical role in meeting the 21st century grand challenges of the US, including energy diversity and sustainability, national security and economic competitiveness. The goal of this work was to develop and fundamentally validate methods of directed selfassembly of nanomaterials and nanodispersion processing. The specific aims were: 1. Nanocolloid self-assembly and interactions in AC electric fields. In an effort to reduce the particle sizes used in AC electric field self-assembly to lengthscales, we propose detailed characterizations of field-driven structures and studies of the fundamental underlying particle interactions. We will utilize microscopy and light scattering to assess order-disorder transitions and self-assembled structures under a variety of field and physicochemical conditions. Optical trapping will be used to measure particle interactions. These experiments will be synergetic with calculations of the particle polarizability, enabling us to both validate interactions and predict the order-disorder transition for nanocolloids. 2. Assembly of anisotropic nanocolloids. Particle shape has profound effects on structure and flow behavior of dispersions, and greatly complicates their processing and self-assembly. The methods developed to study the self-assembled structures and underlying particle interactions for dispersions of isotropic nanocolloids will be extended to systems composed of anisotropic particles. This report reviews several key advances that have been made during this project, including, (1) advances in the measurement of particle polarization mechanisms underlying field-directed self-assembly, and (2) progress in the

  7. Object-Oriented Modeling of Virtual Assembly Process

    Institute of Scientific and Technical Information of China (English)

    ZhengTaixiong; HeYulin; 等

    2002-01-01

    Virtual assembly is a Virtual Reality(VR) based engineering application which allows engineers to evaluate,analyze,and plan the assembly of mechanical systems,To model the virtual assembly process,new methodology must be applied.Based on the idea that the virtual assembly system is an event driven system,the interactive behavior and information model is proposed to describe the dynamic process of virtual assembly.Definition of the objectoriented model of virtual assembly is put forward.

  8. Seismic response of nuclear fuel assembly

    Directory of Open Access Journals (Sweden)

    Hlaváč Z.

    2014-06-01

    Full Text Available The paper deals with mathematical modelling and computer simulation of the seismic response of fuel assembly components. The seismic response is investigated by numerical integration method in time domain. The seismic excitation is given by two horizontal and one vertical synthetic accelerograms at the level of the pressure vessel seating. Dynamic response of the hexagonal type nuclear fuel assembly is caused by spatial motion of the support plates in the reactor core investigated on the reactor global model. The modal synthesis method with condensation is used for calculation of the fuel assembly component displacements and speeds on the level of the spacer grid cells.

  9. System and method for conveying an assembly

    KAUST Repository

    Eitelhuber, Georg

    2015-01-15

    An apparatus, system, and method for conveying an assembly along a track. A rail can include a first planar side, a second planar side, and a third planar side. The first, second, and third planar sides can be arranged to form at least two acute angles. A carriage assembly can include a drive wheel and at least two roller sets. The drive wheel can be configured to contact the first planar side and is configured to translate the carriage assembly along the rail. The at least two roller sets can be configured to contact the two other sides to maintain the carriage in contact with the rail.

  10. Mudular Product Families and Assembly Systems

    DEFF Research Database (Denmark)

    Thyssen, Jesper

    modular product families and the interacting assembly system.   The thesis reviews extant theory and provides various classifications and discussions guided by the overall theme of product modularity and assembly systems. The empirical system analysis, based upon a longitudinal single case study......, articulates a system model incorporating both structural and performance elements. The extensive and detailed case analysis provides the necessary insight into the specific variables associated with the complex configuration of modular products and assembly systems.   Based upon the system model a number of...

  11. Recent development of peptide self-assembly

    Institute of Scientific and Technical Information of China (English)

    Xiubo Zhao; Fang Pan; Jian R. Lu

    2008-01-01

    Amino acids are the building blocks to build peptides and proteins. Recent development in peptide synthesis has however enabled us to mimic this natural process by preparing various long and short peptides possessing different conformations and biological functions. The self-assembly of short designed peptides into molecular nanostructures is becoming a growing interest in nanobiotechnology. Self-assembled peptides exhibit several attractive features for applications in tissue regeneration, drug delivery, biological surface engineering as well as in food science, cosmetic industry and antibiotics. The aim of this review is to introduce the readers to a number of representative studies on peptide self-assembly.

  12. An IBM 370 assembly language program verifier

    Science.gov (United States)

    Maurer, W. D.

    1977-01-01

    The paper describes a program written in SNOBOL which verifies the correctness of programs written in assembly language for the IBM 360 and 370 series of computers. The motivation for using assembly language as a source language for a program verifier was the realization that many errors in programs are caused by misunderstanding or ignorance of the characteristics of specific computers. The proof of correctness of a program written in assembly language must take these characteristics into account. The program has been compiled and is currently running at the Center for Academic and Administrative Computing of The George Washington University.

  13. Nuclear fuel assembly identification using computer vision

    International Nuclear Information System (INIS)

    A new method of identifying fuel assemblies has been developed. The method uses existing in-cell TV cameras to read the notch-coded handling sockets of Fast Flux Test Facility (FFTF) assemblies. A computer looks at the TV image, locates the notches, decodes the notch pattern, and produces the identification number. A TV camera is the only in-cell equipment required, thus avoiding complex mechanisms in the hot cell. Assemblies can be identified in any location where the handling socket is visible from the camera. Other advantages include low cost, rapid identification, low maintenance, and ease of use

  14. Computer organization and assembly language programming

    CERN Document Server

    Peterson, James L

    1978-01-01

    Computer Organization and Assembly Language Programming deals with lower level computer programming-machine or assembly language, and how these are used in the typical computer system. The book explains the operations of the computer at the machine language level. The text reviews basic computer operations, organization, and deals primarily with the MIX computer system. The book describes assembly language programming techniques, such as defining appropriate data structures, determining the information for input or output, and the flow of control within the program. The text explains basic I/O

  15. Lightweight IMM PV Flexible Blanket Assembly

    Science.gov (United States)

    Spence, Brian

    2015-01-01

    Deployable Space Systems (DSS) has developed an inverted metamorphic multijunction (IMM) photovoltaic (PV) integrated modular blanket assembly (IMBA) that can be rolled or z-folded. This IMM PV IMBA technology enables a revolutionary flexible PV blanket assembly that provides high specific power, exceptional stowed packaging efficiency, and high-voltage operation capability. DSS's technology also accommodates standard third-generation triple junction (ZTJ) PV device technologies to provide significantly improved performance over the current state of the art. This SBIR project demonstrated prototype, flight-like IMM PV IMBA panel assemblies specifically developed, designed, and optimized for NASA's high-voltage solar array missions.

  16. Research of the Assembly Model Based on Petri Net

    Institute of Scientific and Technical Information of China (English)

    LI Rong; FU Yili; MA Yulin; FENG Haibo

    2006-01-01

    Assembly model plans an important role in assembly sequence planning. Flexible assembly system(FAS) is a discrete event system(DES), so Petri net, as an important analytical tool for the DES, is used for modeling of an FAS. All of the feasible assembly sequences can be obtained by firing the Petri net model. In order to enhancing the efficiency of the assembly sequence planning, knowledge-based Petri net, combining an usual Petri net with expert's knowledge and experiences, is proposed to construct the assembly model. So the feasible assembly sequences can be reduced greatly, and the optimum assembly sequence could be generated without the combinatorial explosion of solutions.

  17. Virtual Teaching Simulation for Robot Assembly Accuracy Analysis

    Institute of Scientific and Technical Information of China (English)

    张征; 周宏甫; 刘斌

    2004-01-01

    In this paper, by teaching a 3D robot unit model and playing back to simulate the assembly process in a virtual assembly environment, errors in robot assembly are analyzed. The paper also presents a visualization method for analyzing accuracy of the robot assembly, and studies the influence of the spatial pose of a robot on the success rate of an axis-hole assembly, and accuracy of the robot teaching program in particular. Through integration of various errors and on the basis of assembly accuracy, tolerance of error sources can be reasonably distributed to meet the assembly accuracy requirement, therefore the planning of robot assembly unit can be improved.

  18. Self assembly of interlocked architectures

    International Nuclear Information System (INIS)

    An area of great interest is the synthesis and characterisation of molecules possessing moving parts, with the goal that they can act as 'molecular machine' carrying out tasks that molecules with fixed conventional architectures cannot do. Rotaxanes and catenanes (mechanically interlocked architectures) represent one approach toward achieving these aims as their component wheels and / or threads are connected together but can still move, in certain, controlled directions. This thesis focused on the study of structural rigidity and the preorganisation of thread binding sites as factors of major influence on template efficiency in the synthesis of hydrogen bond assembled supramolecular structures (rotaxanes and catenanes). Chapter One gives a brief outline of the common synthetic approaches to interlocked architectures (catenanes and rotaxanes) that are now being developed to address the problems outlined above. Chapter Two and Chapter Three concerns the synthesis of novel amide-based rotaxanes containing various saturated and unsaturated skeletons in their templating core. These new amide-based rotaxanes (muconic, hydromuconic and glutaconic) were synthesised by a clipping strategy in high yields. Chapter Four concerns the synthesis of a novel class of rotaxanes containing a naphthalene tetramide macrocycle that has a larger cavity (102). Several rotaxanation experiments based on macrocycle 102 precursors and threads containing several possible templating motifs were examined. Chapter Five report on the use of rotaxane wheels as a non-covalent protecting group able to influence the chemical behaviour of the functional groups in the central part of the axle. Chapter Six several heterocircuit [2]catenanes functionalised with various sulphide groups were synthesised and their monolayer forming capability on a gold surface studied. Another approach involving covalent attachment of macrocycles and catenanes on a pre-formed monolayer was also investigated. (author)

  19. Biomolecular Assembly of Gold Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Micheel, Christine Marya [Univ. of California, Berkeley, CA (United States)

    2005-05-20

    Over the past ten years, methods have been developed to construct discrete nanostructures using nanocrystals and biomolecules. While these frequently consist of gold nanocrystals and DNA, semiconductor nanocrystals as well as antibodies and enzymes have also been used. One example of discrete nanostructures is dimers of gold nanocrystals linked together with complementary DNA. This type of nanostructure is also known as a nanocrystal molecule. Discrete nanostructures of this kind have a number of potential applications, from highly parallel self-assembly of electronics components and rapid read-out of DNA computations to biological imaging and a variety of bioassays. My research focused in three main areas. The first area, the refinement of electrophoresis as a purification and characterization method, included application of agarose gel electrophoresis to the purification of discrete gold nanocrystal/DNA conjugates and nanocrystal molecules, as well as development of a more detailed understanding of the hydrodynamic behavior of these materials in gels. The second area, the development of methods for quantitative analysis of transmission electron microscope data, used computer programs written to find pair correlations as well as higher order correlations. With these programs, it is possible to reliably locate and measure nanocrystal molecules in TEM images. The final area of research explored the use of DNA ligase in the formation of nanocrystal molecules. Synthesis of dimers of gold particles linked with a single strand of DNA possible through the use of DNA ligase opens the possibility for amplification of nanostructures in a manner similar to polymerase chain reaction. These three areas are discussed in the context of the work in the Alivisatos group, as well as the field as a whole.

  20. Fuel fire tests of selected assemblies

    Science.gov (United States)

    Kydd, G.; Spindola, K.; Askew, G. K.

    1982-04-01

    A varing assortment of clothing assemblies was tested in the Fuel Fire Test Facility at the Naval Air Development Center. Included was a Nomex-Kevlar Cloque Coverall which had relatively good protection from fuel flames.

  1. Two LHC dipole magnets in assembly hall

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    The final LHC components are completed in the assembly hall, prior to installation in the tunnel. These pictures show two 15-m long LHC cryogenic magnets, both before and after insertion into their blue vacuum vessel.

  2. Optimal production planning for PCB assembly

    CERN Document Server

    Ho, William

    2006-01-01

    Focuses on the optimization of the Printed circuit board (PCB) assembly lines' efficiency. This book integrates the component sequencing and the feeder arrangement problems together for the pick-and-place machine and the chip shooter machines.

  3. Molecular motor assembly of a biomimetic system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.

  4. Methods of making membrane electrode assemblies

    Science.gov (United States)

    Kim, Yu Seung; Lee, Kwan -Soo; Rockward, Tommy Q. T.

    2015-07-28

    Method of making a membrane electrode assembly comprising: providing a membrane comprising a perfluorinated sulfonic acid; providing a first transfer substrate; applying to a surface of the first transfer substrate a first ink, said first ink comprising an ionomer and a catalyst; applying to the first ink a suitable non-aqueous swelling agent; forming an assembly comprising: the membrane; and the first transfer substrate, wherein the surface of the first transfer substrate comprising the first ink and the non-aqueous swelling agent is disposed upon one surface of the membrane; and heating the assembly at a temperature of 150.degree. C. or less and at a pressure of from about 250 kPa to about 3000 kPa or less for a time suitable to allow substantially complete transfer of the first ink and the second ink to the membrane; and cooling the assembly to room temperature and removing the first transfer substrate and the second transfer substrate.

  5. Biophysical Regulation of Vascular Differentiation and Assembly

    CERN Document Server

    Gerecht, Sharon

    2011-01-01

    The ability to grow stem cells in the laboratory and to guide their maturation to functional cells allows us to study the underlying mechanisms that govern vasculature differentiation and assembly in health and disease. Accumulating evidence suggests that early stages of vascular growth are exquisitely tuned by biophysical cues from the microenvironment, yet the scientific understanding of such cellular environments is still in its infancy. Comprehending these processes sufficiently to manipulate them would pave the way to controlling blood vessel growth in therapeutic applications. This book assembles the works and views of experts from various disciplines to provide a unique perspective on how different aspects of its microenvironment regulate the differentiation and assembly of the vasculature. In particular, it describes recent efforts to exploit modern engineering techniques to study and manipulate various biophysical cues. Biophysical Regulation of Vascular Differentiation and Assembly provides an inter...

  6. BWR Assembly Optimization for Minor Actinide Recycling

    Energy Technology Data Exchange (ETDEWEB)

    G. Ivan Maldonado; John M. Christenson; J.P. Renier; T.F. Marcille; J. Casal

    2010-03-22

    The Primary objective of the proposed project is to apply and extend the latest advancements in LWR fuel management optimization to the design of advanced boiling water reactor (BWR) fuel assemblies specifically for the recycling of minor actinides (MAs).

  7. Rack assembly for mounting solar modules

    Science.gov (United States)

    Plaisted, Joshua Reed; West, Brian

    2010-12-28

    A rack assembly is provided for mounting solar modules over an underlying body. The rack assembly may include a plurality of rail structures that are arrangeable over the underlying body to form an overall perimeter for the rack assembly. One or more retention structures may be provided with the plurality of rail structures, where each retention structure is configured to support one or more solar modules at a given height above the underlying body. At least some of the plurality of rail structures are adapted to enable individual rail structures o be sealed over the underlying body so as to constrain air flow underneath the solar modules. Additionally, at least one of (i) one or more of the rail structures, or (ii) the one or more retention structures are adjustable so as to adapt the rack assembly to accommodate solar modules of varying forms or dimensions.

  8. The Assembly Hall in Lab II

    CERN Multimedia

    1974-01-01

    Magnets and components of all types for the SPS were delivered and stored in this hall during 1974. There also took place the testing, assembly and final preparation of components to be installed in the ring tunnel.

  9. Defining of the BDX930 Assembly Language

    Science.gov (United States)

    Boyer, R. S.; Moore, J. S.

    1983-01-01

    A definition of the BDX930 assembly language is presented. Various definition problems and suggested solutions are included. A class of defined recognizers based on boolean valued nowrecursive functions is employed in preprocessing.

  10. SolidWorks 2011 Assemblies Bible

    CERN Document Server

    Lombard, Matt

    2011-01-01

    A fan of the SolidWorks Bible, but want more detail on assemblies? Here you go. SolidWorks fans have long sought more detail on SolidWorks topics, and now you have it. We took our popular SolidWorks Bible, divided it into two books (SolidWorks 2011 Assemblies Bible and SolidWorks 2011 Parts Bible) and packed each new book with a host of items from your wish lists, such as more extensive coverage of the basics, additional tutorials, and expanded coverage of topics largely ignored by other books. This SolidWorks 2011 Assemblies Bible shows you how to organize parts data to create assemblies or s

  11. V-GAP: Viral genome assembly pipeline

    KAUST Repository

    Nakamura, Yoji

    2015-10-22

    Next-generation sequencing technologies have allowed the rapid determination of the complete genomes of many organisms. Although shotgun sequences from large genome organisms are still difficult to reconstruct perfect contigs each of which represents a full chromosome, those from small genomes have been assembled successfully into a very small number of contigs. In this study, we show that shotgun reads from phage genomes can be reconstructed into a single contig by controlling the number of read sequences used in de novo assembly. We have developed a pipeline to assemble small viral genomes with good reliability using a resampling method from shotgun data. This pipeline, named V-GAP (Viral Genome Assembly Pipeline), will contribute to the rapid genome typing of viruses, which are highly divergent, and thus will meet the increasing need for viral genome comparisons in metagenomic studies.

  12. Photonic hybrid assembly through flexible waveguides

    Science.gov (United States)

    Wörhoff, K.; Prak, A.; Postma, F.; Leinse, A.; Wu, K.; Peters, T. J.; Tichem, M.; Amaning-Appiah, B.; Renukappa, V.; Vollrath, G.; Balcells-Ventura, J.; Uhlig, P.; Seyfried, M.; Rose, D.; Santos, R.; Leijtens, X. J. M.; Flintham, B.; Wale, M.; Robbins, D.

    2016-05-01

    Fully automated, high precision, cost-effective assembly technology for photonic packages remains one of the main challenges in photonic component manufacturing. Next to the cost aspect the most demanding assembly task for multiport photonic integrated circuits (PICs) is the high-precision (±0.1 μm) alignment and fixing required for optical I/O in InP PICs, even with waveguide spot size conversion. In a European research initiative - PHASTFlex - we develop and investigate an innovative, novel assembly concept, in which the waveguides in a matching TriPleX interposer PIC are released during fabrication to make them movable. After assembly of both chips by flip-chip bonding on a common carrier, TriPleX based actuators and clamping functions position and fix the flexible waveguides with the required accuracy.

  13. Nozzle and shroud assembly mounting structure

    Science.gov (United States)

    Faulder, Leslie J.; Frey, deceased, Gary A.; Nielsen, Engward W.; Ridler, Kenneth J.

    1997-01-01

    The present nozzle and shroud assembly mounting structure configuration increases component life and reduces maintenance by reducing internal stress between the mounting structure having a preestablished rate of thermal expansion and the nozzle and shroud assembly having a preestablished rate of thermal expansion being less than that of the mounting structure. The mounting structure includes an outer sealing portion forming a cradling member in which an annular ring member is slidably positioned. The mounting structure further includes an inner mounting portion to which a hooked end of the nozzle and shroud assembly is attached. As the inner mounting portion expands and contracts, the nozzle and shroud assembly slidably moves within the outer sealing portion.

  14. Fathead minnow genome sequencing and assembly

    Data.gov (United States)

    U.S. Environmental Protection Agency — The dataset provides the URLs for accessing the genome sequence data and two draft assemblies as well as fathead minnow genotyping data associated with estimating...

  15. Constraints on Assembly Bias from Galaxy Clustering

    OpenAIRE

    Zentner, Andrew R.; Hearin, Andrew; Bosch, Frank C. van den; Lange, Johannes U.; Villarreal, Antonio

    2016-01-01

    We constrain the newly-introduced decorated Halo Occupation Distribution (HOD) model using SDSS DR7 measurements of projected galaxy clustering or r-band luminosity threshold samples. The decorated HOD is a model for the galaxy-halo connection that augments the HOD by allowing for the possibility of galaxy assembly bias: galaxy luminosity may be correlated with dark matter halo properties besides mass, Mvir. We demonstrate that it is not possible to rule out galaxy assembly bias using DR7 mea...

  16. From Self-Assembled Vesicles to Protocells

    OpenAIRE

    Chen, Irene A.; Walde, Peter

    2010-01-01

    Self-assembled vesicles are essential components of primitive cells. We review the importance of vesicles during the origins of life, fundamental thermodynamics and kinetics of self-assembly, and experimental models of simple vesicles, focusing on prebiotically plausible fatty acids and their derivatives. We review recent work on interactions of simple vesicles with RNA and other studies of the transition from vesicles to protocells. Finally we discuss current challenges in understanding the ...

  17. Optimal Assembly for High Throughput Shotgun Sequencing

    OpenAIRE

    Bresler, Guy; Bresler, Ma'ayan; Tse, David

    2013-01-01

    Abstract We present a framework for the design of optimal assembly algorithms for shotgun sequencing under the criterion of complete reconstruction. We derive a lower bound on the read length and the coverage depth required for reconstruction in terms of the repeat statistics of the genome. Building on earlier works, we design a de Brujin graph based assembly algorithm which can achieve very close to the lower bound for repeat statistics of a wide range of seque...

  18. Fourier-Bessel Reconstruction of Helical Assemblies

    OpenAIRE

    Diaz, Ruben; Rice, William; Stokes, David L.

    2010-01-01

    Helical symmetry is commonly used for building macromolecular assemblies. Helical symmetry is naturally present in viruses and cytoskeletal filaments and also occurs during crystallization of isolated proteins, such as Ca-ATPase and the nicotinic acetyl choline receptor. Structure determination of helical assemblies by electron microscopy has a long history dating back to the original work on three-dimensional reconstruction. A helix offers distinct advantages for structure determination. Not...

  19. Establishment of China Nuclear Fuel Assembly Database

    Institute of Scientific and Technical Information of China (English)

    CHENPeng; ZHANGYing-chao; LIUTing-jin; JINYong-li

    2003-01-01

    During researching, designing, manufacturing and post irradiation, a large amount of data on fuel assembly of China nuclear power plants has been accumulated. It is necessary to collect the data together,so that the researchers, designers, manufactures and managers could use the data conveniently. It was proposed to establish a China Nuclear Fuel Assembly Database through the Internet on workstations during the year of 2003 to 2006, so the data would be shared in China nuclear industry.

  20. Mössbauer spectra of assembled complex

    International Nuclear Information System (INIS)

    Applications of Mössbauer spectrometry, which reveals a detail in stepwise spin transition in binuclear, trinuclear, and tetranuclear complex, are introduced to the study of spin-crossover phenomena. The appearance of spin-crossover phenomenon by enclathrating guest molecule in the assembled complex is introduced. A variety of assembled structures are obtained by changing conformer of bridging ligand. The reversible structural change of host framework triggered by desorption and adsorption of guest benzene molecules was also introduced. (author)

  1. Thermal Analysis of a TREAT Fuel Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Papadias, Dionissios [Argonne National Lab. (ANL), Argonne, IL (United States); Wright, Arthur E. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-07-09

    The objective of this study was to explore options as to reduce peak cladding temperatures despite an increase in peak fuel temperatures. A 3D thermal-hydraulic model for a single TREAT fuel assembly was benchmarked to reproduce results obtained with previous thermal models developed for a TREAT HEU fuel assembly. In exercising this model, and variants thereof depending on the scope of analysis, various options were explored to reduce the peak cladding temperatures.

  2. Uniform yeast cell assembly via microfluidics

    OpenAIRE

    Chang, Ya-Wen; He, Peng; Marquez, Samantha M.; Cheng, Zhengdong

    2012-01-01

    This paper reports the use of microfluidic approaches for the fabrication of yeastosomes (yeast-celloidosomes) based on self-assembly of yeast cells onto liquid-solid or liquid-gas interfaces. Precise control over fluidic flows in droplet- and bubble-forming microfluidic devices allows production of monodispersed, size-selected templates. The general strategy to organize and assemble living cells is to tune electrostatic attractions between the template (gel or gas core) and the cells via sur...

  3. Interactive Assembly Guide using Augmented Reality

    DEFF Research Database (Denmark)

    Andersen, Martin; Andersen, Rasmus Skovgaard; Larsen, Christian Lindequist;

    2009-01-01

    This paper presents an Augmented Reality system for aiding a pump assembling process at Grundfos, one of the leading pump producers. Stable pose estimation of the pump is required in order to augment the graphics correctly. This is achieved by matching image edges with synthesized edges from CAD...... norm. A dynamic visualization of the augmented graphics provides the user with guidance. Usability tests show that the accuracy of the system is sufficient for assembling the pump....

  4. The assembly and structure of self-assembling peptides: molecular to supramolecular

    OpenAIRE

    Morris, Kyle

    2012-01-01

    Self-assembling molecules are central to a plethora of processes found in nature, biotechnology and even disease. The importance of the non-covalent interaction of monomers to the formation of fibrillar assemblies is evident in the repeated use of this mechanism throughout nature, from essential cellular processes such as the formation of the cytoskeleton to the production of silk. Further, it has been recognised in the last two decades that a self-assembly mechanism, that is t...

  5. Assisted Assembly: How to Improve a De Novo Genome Assembly By Using Related Species

    OpenAIRE

    Gnerre, Sante; Lindblad-Toh, Kerstin; Jaffe, David B; Lander, Eric Steven

    2009-01-01

    We describe a new assembly algorithm, where a genome assembly with low sequence coverage, either throughout the genome or locally, due to cloning bias, is considerably improved through an assisting process via a related genome. We show that the information provided by aligning the whole-genome shotgun reads of the target against a reference genome can be used to substantially improve the quality of the resulting assembly.

  6. Self-assembly micro optical filter

    Science.gov (United States)

    Zhang, Ping (Cerina); Le, Kevin; Malalur-Nagaraja-Rao, Smitha; Hsu, Lun-Chen; Chiao, J.-C.

    2006-01-01

    Optical communication and sensor industry face critical challenges in manufacturing for system integration. Due to the assembly complexity and integration platform variety, micro optical components require costly alignment and assembly procedures, in which many required manual efforts. Consequently, self-assembly device architectures have become a great interest and could provide major advantages over the conventional optical devices. In this paper, we discussed a self-assembly integration platform for micro optical components. To demonstrate the adaptability and flexibility of the proposed optical device architectures, we chose a commercially available MEMS fabrication foundry service - MUMPs (Multi-User MEMS Process). In this work, polysilicon layers of MUMPS are used as the 3-D structural material for construction of micro component framework and actuators. However, because the polysilicon has high absorption in the visible and near infrared wavelength ranges, it is not suitable for optical interaction. To demonstrate the required optical performance, hybrid integration of materials was proposed and implemented. Organic compound materials were applied on the silicon-based framework to form the required optical interfaces. Organic compounds provide good optical transparency, flexibility to form filters or lens and inexpensive manufacturing procedures. In this paper, we have demonstrated a micro optical filter integrated with self-assembly structures. We will discuss the self-assembly mechanism, optical filter designs, fabrication issues and results.

  7. Mitochondrial ribosome assembly in health and disease.

    Science.gov (United States)

    De Silva, Dasmanthie; Tu, Ya-Ting; Amunts, Alexey; Fontanesi, Flavia; Barrientos, Antoni

    2015-01-01

    The ribosome is a structurally and functionally conserved macromolecular machine universally responsible for catalyzing protein synthesis. Within eukaryotic cells, mitochondria contain their own ribosomes (mitoribosomes), which synthesize a handful of proteins, all essential for the biogenesis of the oxidative phosphorylation system. High-resolution cryo-EM structures of the yeast, porcine and human mitoribosomal subunits and of the entire human mitoribosome have uncovered a wealth of new information to illustrate their evolutionary divergence from their bacterial ancestors and their adaptation to synthesis of highly hydrophobic membrane proteins. With such structural data becoming available, one of the most important remaining questions is that of the mitoribosome assembly pathway and factors involved. The regulation of mitoribosome biogenesis is paramount to mitochondrial respiration, and thus to cell viability, growth and differentiation. Moreover, mutations affecting the rRNA and protein components produce severe human mitochondrial disorders. Despite its biological and biomedical significance, knowledge on mitoribosome biogenesis and its deviations from the much-studied bacterial ribosome assembly processes is scarce, especially the order of rRNA processing and assembly events and the regulatory factors required to achieve fully functional particles. This article focuses on summarizing the current available information on mitoribosome assembly pathway, factors that form the mitoribosome assembly machinery, and the effect of defective mitoribosome assembly on human health.

  8. Metrology Techniques for the Assembly of NCSX

    International Nuclear Information System (INIS)

    In support of the National Compact Stellerator Experiment (NCSX), stellerator assembly activities continued this past year at the Princeton Plasma Physics Laboratory (PPPL) in partnership with the Oak Ridge National Laboratory (ORNL). The construction program saw the completion of the first two Half Field-Period Assemblies (HPA), each consisting of three modular coils. The full machine includes six such sub-assemblies. A single HPA consists of three of the NCSX modular coils wound and assembled at PPPL. These geometrically-complex three dimensional coils were wound using computer-aided metrology and CAD models to tolerances within +/- 0.5mm. The assembly of these coils required similar accuracy on a larger scale with the added complexity of more individual parts and fewer degrees of freedom for correction. Several new potential positioning issues developed for which measurement and control techniques were developed. To accomplish this, CAD coordinate-based computer metrology equipment and software similar to the solutions employed for winding the modular coils was used. Given the size of the assemblies, the primary tools were both interferometer aided and Absolute Distance Measurement (ADM)-only based laser trackers. In addition, portable Coordinate Measurement Machine (CMM) arms and some novel indirect measurement techniques were employed. This paper will detail both the use of CAD coordinate-based metrology technology and the techniques developed and employed for dimensional control of NSCX subassemblies. The results achieved and possible improvements to techniques will be discussed.

  9. Metrology Techniques for the Assembly of NCSX

    Energy Technology Data Exchange (ETDEWEB)

    C. Priniski, T. Dodson, M. Duco, S. Raftopoulos, R. Ellis, and A. Brooks

    2009-09-24

    In support of the National Compact Stellerator Experiment (NCSX), stellerator assembly activities continued this past year at the Princeton Plasma Physics Laboratory (PPPL) in partnership with the Oak Ridge National Laboratory (ORNL). The construction program saw the completion of the first two Half Field-Period Assemblies (HPA), each consisting of three modular coils. The full machine includes six such sub-assemblies. A single HPA consists of three of the NCSX modular coils wound and assembled at PPPL. These geometrically-complex threedimensional coils were wound using computer-aided metrology and CAD models to tolerances within +/- 0.5mm. The assembly of these coils required similar accuracy on a larger scale with the added complexity of more individual parts and fewer degrees of freedom for correction. Several new potential positioning issues developed for which measurement and control techniques were developed. To accomplish this, CAD coordinate-based computer metrology equipment and software similar to the solutions employed for winding the modular coils was used. Given the size of the assemblies, the primary tools were both interferometeraided and Absolute Distance Measurement (ADM)-only based laser trackers. In addition, portable Coordinate Measurement Machine (CMM) arms and some novel indirect measurement techniques were employed. This paper will detail both the use of CAD coordinate-based metrology technology and the techniques developed and employed for dimensional control of NSCX subassemblies. The results achieved and possible improvements to techniques will be discussed.

  10. Subchannel Analysis of Wire Wrapped SCWR Assembly

    Directory of Open Access Journals (Sweden)

    Jianqiang Shan

    2014-01-01

    Full Text Available Application of wire wrap spacers in SCWR can reduce pressure drop and obtain better mixing capability. As a consequence, the required coolant pumping power is decreased and the coolant temperature profile inside the fuel bundle is flattened which will obviously decrease the peak cladding temperature. The distributed resistance model for wire wrap was developed and implemented in ATHAS subchannel analysis code. The HPLWR wire wrapped assembly was analyzed. The results show that: (1 the assembly with wire wrap can obtain a more uniform coolant temperature profile than the grid spaced assembly, which will result in a lower peak cladding temperature; (2 the pressure drop in a wire wrapped assembly is less than that in a grid spaced assembly, which can reduce the operating power of pump effectively; (3 the wire wrap pitch has significant effect on the flow in the assembly. Smaller Hwire/Drod will result in stronger cross flow a more uniform coolant temperature profile, and also a higher pressure drop.

  11. Spontaneous Assembly of Exopolymers from Phytoplankton

    Directory of Open Access Journals (Sweden)

    Yong-Xue Ding

    2009-01-01

    Full Text Available Phytoplankton exopolymeric substances (EPS contribute significantly to the dissolved organic car bon (DOC pool in the ocean, playing crucial roles in the surface ocean car bon cycle. Recent studies have demonstrated that ~10% of marine DOC can self-assemble as microgels through electro static Ca bonds providing hotspots of enriched microbial substrate. How ever, the question whether EPS can self-assemble and the formation mechanisms for EPS microgels have not been examined. Here were port that EPS from three representative phytoplankton species, Synechococcus, Emiliania huxleyi, and Skeletonema costatum can spontaneously self assemble in artificial sea water (ASW, forming microscopic gels of ~ 3 - 4 _ in diameter. Different from the marine DOC polymers assembly, these EPS samples can self-assemble in Ca2+-free ASW. Further experiments from fluorescence enhancement and chemical composition analysis confirmed the existence of fair amounts of hydrophobic domains in these EPS samples. These results suggest that hydrophobic interactions play a key role in the assembly of EPS from these three species of marine phytoplankton.

  12. SparseAssembler2: Sparse k-mer Graph for Memory Efficient Genome Assembly

    CERN Document Server

    Ye, Chengxi; Ma, Zhanshan Sam; Yu, Douglas W; Pop, Mihai

    2011-01-01

    Motivation: To tackle the problem of huge memory usage associated with de Bruijn graph-based algorithms, upon which some of the most widely used de novo genome assemblers have been built, we released SparseAssembler1. SparseAssembler1 can save as much as 90% memory consumption in comparison with the state-of-art assemblers, but it requires rounds of denoising to accurately assemble genomes. In this paper, we introduce a new general model for genome assembly that uses only sparse k-mers. The new model replaces the idea of the de Bruijn graph from the beginning, and achieves similar memory efficiency and much better robustness compared with our previous SparseAssembler1. Results: Based on the sparse k-mers graph model, we develop SparseAssembler2. We demonstrate that the decomposition of reads of all overlapping k-mers, which is used in existing de Bruijn graph genome assemblers, is overly cautious. We introduce a sparse k-mer graph structure for saving sparse k-mers, which greatly reduces memory space requirem...

  13. Identifying wrong assemblies in de novo short read primary sequence assembly contigs

    Indian Academy of Sciences (India)

    VANDNA CHAWLA; RAJNISH KUMAR; RAVI SHANKAR

    2016-09-01

    With the advent of short-reads-based genome sequencing approaches, large number of organisms are being sequencedall over the world. Most of these assemblies are done using some de novo short read assemblers and other relatedapproaches. However, the contigs produced this way are prone to wrong assembly. So far, there is a conspicuousdearth of reliable tools to identify mis-assembled contigs. Mis-assemblies could result from incorrectly deleted orwrongly arranged genomic sequences. In the present work various factors related to sequence, sequencing andassembling have been assessed for their role in causing mis-assembly by using different genome sequencing data.Finally, some mis-assembly detecting tools have been evaluated for their ability to detect the wrongly assembledprimary contigs, suggesting a lot of scope for improvement in this area. The present work also proposes a simpleunsupervised learning-based novel approach to identify mis-assemblies in the contigs which was found performingreasonably well when compared to the already existing tools to report mis-assembled contigs. It was observed that theproposed methodology may work as a complementary system to the existing tools to enhance their accuracy.

  14. New tools for generation IV assemblies modelling

    International Nuclear Information System (INIS)

    Full text of publication follows: In the framework of the development of generation IV concepts, the need of new assembly modelling tools arises. These concepts present more geometrical and spectral heterogeneities (radially and axially). Moreover thermal-hydraulics and neutronics aspects are so closely related that coupled computations are necessary. That raises the need for more precise and flexible tools presenting 3D features. The 3D-coupling of the thermal-hydraulic code FLICA4 with the Monte-Carlo neutronics code TRIPOLI4 was developed in that frame. This new tool enables for the first time to obtain realistic axial and radial power profiles with real feedback effects in an assembly where thermal-hydraulics and neutronics effects are closely related. The BWR is the existing concept presenting the closest heterogeneous characteristics to the various new proposed concepts. This assembly design is thus chosen to compare this new tool, presenting real 3D characteristics, to the existing ones. For design studies, the evaluation of the assembly behavior, currently necessitate a depletion scheme using a 3D thermal-hydraulics assembly calculation coupled with a 1D axial neutronics deterministic calculation (or an axial power profile chosen as a function of the assembly averaged burn-up). The 3D neutronics code (CRONOS2) uses neutronic data built by 2D deterministic assembly calculations without feedback. These cross section libraries enable to take feedbacks into account via parameters such as fuel temperature, moderator density and temperature (history parameters such as void and control rod are not useful in design evaluation). Recently, the libraries build-up has been replaced by on line multi-2D deterministic assembly calculations performed by a cell code (APOLLO2). That avoids interpolation between pre-determined parameters in the cross-section data used by the 1D axial neutronics calculation and enable to give a radial power map to the 3D thermal

  15. 32 CFR 644.460 - Supplemental agreement assembly.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Supplemental agreement assembly. 644.460 Section... Supplemental agreement assembly. (a) Composition. Supplemental agreement assembly, covering agreement for... Government. (b) Distribution. An executed copy of the assembly will be retained by the DE. An executed...

  16. 21 CFR 890.3500 - External assembled lower limb prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External assembled lower limb prosthesis. 890.3500... External assembled lower limb prosthesis. (a) Identification. An external assembled lower limb prosthesis... the lower extremity. Examples of external assembled lower limb prostheses are the following:...

  17. Assembly auxiliary system for narrow cabins of spacecraft

    Science.gov (United States)

    Liu, Yi; Li, Shiqi; Wang, Junfeng

    2015-09-01

    Due to the narrow space and complex structure of spacecraft cabin, the existing asssembly systems can not well suit for the assembly process of cabin products. This paper aims to introduce an assembly auxiliary system for cabin products. A hierarchical-classification method is proposed to re-adjust the initial assembly relationship of cabin into a new hierarchical structure for efficient assembly planning. An improved ant colony algorithm based on three assembly principles is established for searching a optimizational assembly sequence of cabin parts. A mixed reality assembly environment is constructed with enhanced information to promote interaction efficiency of assembly training and guidance. Based on the machine vision technology, the inspection of left redundant objects and measurement of parts distance in inner cabin are efficiently performed. The proposed system has been applied to the assembly work of a spacecraft cabin with 107 parts, which includes cabin assembly planning, assembly training and assembly quality inspection. The application result indicates that the proposed system can be an effective assistant tool to cabin assembly works and provide an intuitive and real assembly experience for workers. This paper presents an assembly auxiliary system for spacecraft cabin products, which can provide technical support to the spacecraft cabin assembly industry.

  18. The construction of the CMS electromagnetic calorimeter: crystal assembly

    CERN Multimedia

    2005-01-01

    This photogallery describes the whole sequence of crystal assembly up to the so-called supermodules of 1700 PWO crystals each. Figures 1-6: submodule (10 crystals + their APDs) assembly with alveola structures. Figs. 7-11: module assembly. Each module is composed by 400 or 500 crystals. Figs. 13-17: supermodule assembly, thermal screen and monitoring, transport.

  19. Templated Self Assemble of Nano-Structures

    Energy Technology Data Exchange (ETDEWEB)

    Suo, Zhigang [Harvard University

    2013-04-29

    This project will identify and model mechanisms that template the self-assembly of nanostructures. We focus on a class of systems involving a two-phase monolayer of molecules adsorbed on a solid surface. At a suitably elevated temperature, the molecules diffuse on the surface to reduce the combined free energy of mixing, phase boundary, elastic field, and electrostatic field. With no template, the phases may form a pattern of stripes or disks. The feature size is on the order of 1-100 nm, selected to compromise the phase boundary energy and the long-range elastic or electrostatic interaction. Both experimental observations and our theoretical simulations have shown that the pattern resembles a periodic lattice, but has abundant imperfections. To form a perfect periodic pattern, or a designed aperiodic pattern, one must introduce a template to guide the assembly. For example, a coarse-scale pattern, lithographically defined on the substrate, will guide the assembly of the nanoscale pattern. As another example, if the molecules on the substrate surface carry strong electric dipoles, a charged object, placed in the space above the monolayer, will guide the assembly of the molecular dipoles. In particular, the charged object can be a mask with a designed nanoscale topographic pattern. A serial process (e.g., e-beam lithography) is necessary to make the mask, but the pattern transfer to the molecules on the substrate is a parallel process. The technique is potentially a high throughput, low cost process to pattern a monolayer. The monolayer pattern itself may serve as a template to fabricate a functional structure. This project will model fundamental aspects of these processes, including thermodynamics and kinetics of self-assembly, templated self-assembly, and self-assembly on unconventional substrates. It is envisioned that the theory will not only explain the available experimental observations, but also motivate new experiments.

  20. Efficient Synergistic Single-Cell Genome Assembly.

    Science.gov (United States)

    Movahedi, Narjes S; Embree, Mallory; Nagarajan, Harish; Zengler, Karsten; Chitsaz, Hamidreza

    2016-01-01

    As the vast majority of all microbes are unculturable, single-cell sequencing has become a significant method to gain insight into microbial physiology. Single-cell sequencing methods, currently powered by multiple displacement genome amplification (MDA), have passed important milestones such as finishing and closing the genome of a prokaryote. However, the quality and reliability of genome assemblies from single cells are still unsatisfactory due to uneven coverage depth and the absence of scattered chunks of the genome in the final collection of reads caused by MDA bias. In this work, our new algorithm Hybrid De novo Assembler (HyDA) demonstrates the power of coassembly of multiple single-cell genomic data sets through significant improvement of the assembly quality in terms of predicted functional elements and length statistics. Coassemblies contain significantly more base pairs and protein coding genes, cover more subsystems, and consist of longer contigs compared to individual assemblies by the same algorithm as well as state-of-the-art single-cell assemblers SPAdes and IDBA-UD. Hybrid De novo Assembler (HyDA) is also able to avoid chimeric assemblies by detecting and separating shared and exclusive pieces of sequence for input data sets. By replacing one deep single-cell sequencing experiment with a few single-cell sequencing experiments of lower depth, the coassembly method can hedge against the risk of failure and loss of the sample, without significantly increasing sequencing cost. Application of the single-cell coassembler HyDA to the study of three uncultured members of an alkane-degrading methanogenic community validated the usefulness of the coassembly concept. HyDA is open source and publicly available at http://chitsazlab.org/software.html, and the raw reads are available at http://chitsazlab.org/research.html. PMID:27243002

  1. Lipid nanoparticle interactions and assemblies

    Science.gov (United States)

    Preiss, Matthew Ryan

    Novel liposome-nanoparticle assemblies (LNAs) provide a biologically inspired route for designing multifunctional bionanotheranostics. LNAs combine the benefits of lipids and liposomes to encapsulate, transport, and protect hydrophilic and hydrophobic therapeutics with functional nanoparticles. Functional nanoparticles endow LNAs with additional capabilities, including the ability to target diseases, triggered drug release, controlled therapeutic output, and diagnostic capabilities to produce a drug delivery system that can effectively and efficiently deliver therapeutics while reducing side effects. Not only could LNAs make existing drugs better, they could also provide an avenue to allow once promising non-approved drugs (rejected due to harmful side effects, inadequate pharmacokinetics, and poor efficacy) to be safely used through targeted and controlled delivery directly to the diseased site. LNAs have the potential to be stimuli responsive, delivering drugs on command by external (ultrasound, RF heating, etc.) or internal (pH, blood sugar, heart rate, etc.) stimuli. Individually, lipids and nanoparticles have been clinically approved for therapy, such as Doxil (a liposomal doxorubicin for cancer treatment), and diagnosis, such as Feridex (an iron oxide nanoparticle an MRI contrast enhancement agent for liver tumors). In order to engineer these multifunctional LNAs for theranostic applications, the interactions between nanoparticles and lipids must be better understood. This research sought to explore the formation, design, structures, characteristics, and functions of LNAs. To achieve this goal, different types of LNAs were formed, specifically magnetoliposomes, bilayer decorated LNAs (DLNAs), and lipid-coated magnetic nanoparticles (LMNPs). A fluorescent probe was embedded in the lipid bilayer of magnetoliposomes allowing the local temperature and membrane fluidity to be observed. When subjected to an electromagnetic field that heated the encapsulated iron

  2. CRBRP modular steam generator tube-to-tubesheet and shell-closure welding

    International Nuclear Information System (INIS)

    The original Modular Steam Generator (MSG), whiand inh was designed, built, and tested by the Energy Systems Group (ESG) of Rockwell International, was a departure from conventional boilers or heat exchangers. The design was a hockeystick concept - the upper section of the generator is curved 900. Factors affecting operating parameters were considered and incorporated in the original MSG design. The MSG was fully instrumented and functionally tested at the Energy Technology Engineering Center at Rockwell. The MSG steamed continuously for over 4000 h, and at the conclusion of the 9000-h test cycle, it was systematically dismantled and examined for wear to critical components. This paper explains the solutions to several manufacturing challenges presented by the unique design of the MSG

  3. Development of a new tube-to-tubesheet welding type for FBR's heat exchangers

    International Nuclear Information System (INIS)

    The intermediate heat exchanger for exchanging heat between primary and secondary sodium and the steam generator are required to guarantee the performance and the reliability of construction over long term under the environment of high temperature sodium peculiar to a FBR. With the increase of power output of FBR plants, the number of heating tubes and the size of tube plates of the intermediate heat exchangers of shell and tube type increase. In order to improve the reliability and the production process of the tube to tube plate welding, a new method was developed, according to which heating tubes are inserted into tube plate holes by about their thickness, and the welding of perfect penetration is carried out internally with an automatic TIG welder. At the same time, in order to confirm the reliability of the welded joints by this method, the tests for evaluating the strength for short time and long term were carried out. It was confirmed that the satisfactory performance of the welded joints was able to be obtained, and the method would be applicable to actual heat exchangers. As for the nondestructive inspection of welded joints, the radiographic method was established, and ultrasonic and eddy current flaw detection methods are being developed now. (Kako, I.)

  4. An Approach to Finite Element Analysis of Boiler Tube-Sheet

    Directory of Open Access Journals (Sweden)

    R. D. Patil, Dr. Bimlesh Kumar

    2013-08-01

    Full Text Available This paper work deals with the stress analysis of plates perforated by holes in square pitch pattern. For this consider the in plane loading condition. In this paper, for in plane loading a 4 x 4 pattern of hole i.e. 16 holes arranged in square pattern and subjected to uniaxial tension is considered. For this case first photo elasticmodels are fabricated by using photo elastic materials. Then the same models are analyzing by using the photo elastic method. The same configuration is used and tested for uniaxial tension by using the finite element method.

  5. Novel Interface for Simulation of Assembly Operations in Virtual Environments

    Directory of Open Access Journals (Sweden)

    CRACIUN, E.-G.

    2013-02-01

    Full Text Available The objective of this paper is to propose a new interface based on human gestures for simulation of assembly operation inside virtual environments. Using as a guide the current context for assembly simulation, we have analyzed the existing techniques used in developing gesture-based interface and extracted the constituent elements for an assembly gesture interface. The interface we propose offers support for assembly/disassembly operation, replace or delete components inside a virtual scene. To improve the current practice in virtual assembly simulation, our interface is an efficient method for assembly operations and a competitive approach for the current assembly simulation techniques.

  6. Fracture resistance of a selection of full-contour all-ceramic crowns: an in vitro study.

    Science.gov (United States)

    Zesewitz, Tim F; Knauber, Andreas W; Northdurft, Frank P

    2014-01-01

    This study aimed to evaluate the fracture resistance of monolithic single crowns made from zirconia (ZI), lithium disilicate (LS2), or feldspar ceramic (FC). Five groups of crowns representing a maxillary first molar were made with the appropriate dimensions according to the manufacturer's instructions. The ZI and LS2 crowns were luted adhesively or cemented conventionally on a metal abutment tooth analog. The feldspar ceramic crowns were luted adhesively. All specimens underwent axial loading until fracture. The crowns in the ZI groups possessed the highest fracture resistance independent of the mode of fixation.

  7. Microfractures in metal-ceramic and all-ceramic implant-supported fixed dental prostheses caused by superstructure fixation.

    Science.gov (United States)

    Karl, Matthias; Graef, Friedrich; Wichmann, Manfred; Beck, Nina

    2012-01-01

    The effect of ceramic veneering on the passivity of fit of cast metal and CAD/CAM-fabricated zirconia ceramic implant-supported three-unit cement-retained restorations was investigated, as well as the effect of misfit stress on the marginal integrity of ceramic veneers. Superstructures were fabricated using cast metal or by CAD/CAM milling of presintered or HIP zirconia ceramic (n=10). Before and after veneering, strain gages were used to measure in vitro the strain developed in all the restorations as a result of superstructure fixation. Fluorescent penetrant method was used to detect microcracks developed in ceramic veneers. Cast frameworks showed significantly higher strain values than CAD/CAM frameworks (p=0.000). Veneering significantly increased strain development in all CAD/CAM frameworks (p=0.000). Compared to zirconia ceramic restorations, significantly more microcracks were observed in cast restorations (p=0.000) both before and after superstructure fixation. PMID:22673463

  8. Fracture strength of custom-fabricated Celay all-ceramic post and core restored endodontically treated teeth

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-xing; ZHANG Wei-hong; LU Zhi-yue; WANG Ke-li

    2006-01-01

    Background The increased use of ail-ceramic crown provides a rationale for tooth-colored core. Due to superior mechanicai properties, Vita Celay infiltration ceramic developed for crown and bridge works presents the potential for fabricating ail-ceramic posts and cores in one piece. This study was conducted to compare the fracture strength of endodontically treated teeth which were thereafter given different types of posts and cores and crowns restoration, respectively. The evaluated post-and-core systems are: custom-fabricated Celay ail-ceramic post-core, custom cast metal post-core, and prefabricated stainless steel post (Parapost) with and without 2.0 mm dentine ferrule.Methods Sixty freshly extracted human maxillary central incisors were endodonticaily treated and randomly divided into five groups with 12 samples each. Group A: Celay ceramic post-cores restored teeth with 2.0 mm dentine ferrule. Group B: Celay ceramic post-cores restored teeth with no dentine ferrule. Group C: cast metal post-cores restored teeth with 2.0 mm dentine ferrule. Group D: cast metal post-cores restored teeth with no dentine ferrule. Group E: prefabricated post and composite cores restored teeth with 2.0 mm dentine ferrule. All teeth were restored with Celay ceramic crowns. Each specimen was subjected to a load at a 45-degree angle to the long axis on MTS 810 material testing machine until failure, at crosshead speed of 0.02 em/minute. Analysis of variance followed by the Newman-Keuls pairwise multiple comparison tests were used to compare the results of the groups tested.Results There was a statistically significant difference among the five groups (P<0.01). Celay ceramic post-cores restored teeth with 2.0 mm dentine ferrule [(758.35±119.26) N] and cast metal post-cores restored teeth with 2.0 mm dentine ferrule [(756.63 ±166.22) N] had a significantly greater mean fracture strength than the other three groups in which no significant difference was observed. The 2.0 mm dentine ferrule could cause significant fracture resistance alteration of Celay post-core restored teeth.Conclusions When covered with Celay ceramic crowns, Celay post-cores restored teeth with 2.0 mm dentine ferrule and cast metal post-cores restored teeth with 2.0 mm dentine ferrule have similar fracture strength. There was a statistically significant difference between the fracture resistance of Celay post-core restored teeth with and without 2.0 mm dentine ferrule.

  9. Chairside Fabrication of an All-Ceramic Partial Crown Using a Zirconia-Reinforced Lithium Silicate Ceramic.

    Science.gov (United States)

    Rinke, Sven; Pabel, Anne-Kathrin; Rödiger, Matthias; Ziebolz, Dirk

    2016-01-01

    The chairside fabrication of a monolithic partial crown using a zirconia-reinforced lithium silicate (ZLS) ceramic is described. The fully digitized model-free workflow in a dental practice is possible due to the use of a powder-free intraoral scanner and the computer-aided design/computer-assisted manufacturing (CAD/CAM) of the restorations. The innovative ZLS material offers a singular combination of fracture strength (>370 Mpa), optimum polishing characteristics, and excellent optical properties. Therefore, this ceramic is an interesting alternative material for monolithic restorations produced in a digital workflow. PMID:27042362

  10. Chairside Fabrication of an All-Ceramic Partial Crown Using a Zirconia-Reinforced Lithium Silicate Ceramic

    Directory of Open Access Journals (Sweden)

    Sven Rinke

    2016-01-01

    Full Text Available The chairside fabrication of a monolithic partial crown using a zirconia-reinforced lithium silicate (ZLS ceramic is described. The fully digitized model-free workflow in a dental practice is possible due to the use of a powder-free intraoral scanner and the computer-aided design/computer-assisted manufacturing (CAD/CAM of the restorations. The innovative ZLS material offers a singular combination of fracture strength (>370 Mpa, optimum polishing characteristics, and excellent optical properties. Therefore, this ceramic is an interesting alternative material for monolithic restorations produced in a digital workflow.

  11. Restauraciones estéticas de porcelana pura: Sistema Cercon Aesthetic all-ceramic restorations: Cercon System

    Directory of Open Access Journals (Sweden)

    E. Fernández Bodereau

    2011-10-01

    Full Text Available La estética en odontología está orientada a imitar la naturaleza, a tratar de conservar las proporciones, las formas, el color, la simetría. La tecnología ha desarrollado materiales cerámicos libres de metal que han reemplazado a los materiales tradicionales, capaces de imitar mejor a la naturaleza. El óxido de circonio parcialmente estabilizado con itrio, no solo es extremadamente resistente, sino que posee la ventaja de ser altamente translucido. Su translucidez de aproximadamente el 50% de la luz incidente, permite la elaboración de restauraciones con apariencia natural. La duración del proceso de escaneado y fresado dependerá del tamaño del objeto, del número de objetos procesados y de los pasos seleccionados (CAM o CAD/CAM. La estructura de óxido de circonio densamente sinterizado con su preciso ajuste, se cubre con la cerámica de recubrimiento que ha sido especialmente desarrollada para este propósito. En casi todos los casos que se nos plantean hay un solo diagnóstico, pero distintas alternativas de plantear el tratamiento. El éxito de estas restauraciones será predecible siempre que se fundamente en el conocimiento de los principios biológicos que la sustentan. El objetivo de esta publicación es exponer de manera concisa las bases teóricas a modo esquemático y las imágenes de la secuencia del tratamiento clínico.Aesthetic dentistry is dedicated to imitate nature by maintaining the size, shape, colour and symmetry. Technology has developed metal-free ceramic materials so capable of reproducing a natural appearance, that traditional materials have been replaced by them. The yttrium partially-stabilized zirconium oxide does not only have the advantage of being extremelly resistant, but it is also highly translucent. It has a translucency that allows about 50% of the incident light to pass through, a characteristic that is vital for providing a more natural appearance to restorations. The duration of scanning and milling procedures will depend on the size of the object, the number of objects proccessed and the steps selected (CAM or CAD/CAM. The framework of the densely sintered zirconium oxide with its precise fit is veneered with the veneering ceramic developed especially for this purpose. Almost in all cases, there are several treatment alternatives for the same diagnosis. The success of these restorations will be predicted as long as it is founded on sustaining biological principles. The aim of this paper is to concisely present the sequences for a clinical treatment in a schematic and illustrative manner.

  12. Chairside Fabrication of an All-Ceramic Partial Crown Using a Zirconia-Reinforced Lithium Silicate Ceramic

    OpenAIRE

    Sven Rinke; Anne-Kathrin Pabel; Matthias Rödiger; Dirk Ziebolz

    2016-01-01

    The chairside fabrication of a monolithic partial crown using a zirconia-reinforced lithium silicate (ZLS) ceramic is described. The fully digitized model-free workflow in a dental practice is possible due to the use of a powder-free intraoral scanner and the computer-aided design/computer-assisted manufacturing (CAD/CAM) of the restorations. The innovative ZLS material offers a singular combination of fracture strength (>370 Mpa), optimum polishing characteristics, and excellent optical prop...

  13. Marginal adaptation of 1 fiber-reinforced composite and 2 all-ceramic inlay fixed partial denture systems

    OpenAIRE

    Monaco, Carlo; Krejci, Ivo; Bortolotto Ibarra, Tissiana; Perakis, Nikolaos; Ferrari,Marco; Scotti, Roberto

    2006-01-01

    The aim of this in vitro study was to evaluate the marginal adaptation and retention of inlay fixed partial dentures (IFPDs) made with 1 fiber-reinforced composite and 2 different ceramic materials using quantitative scanning electron microscope analysis after thermal cycling and mechanical loading, which simulated approximately 5 years of oral service.

  14. Research advances on all-ceramic fixed partial dentures%全瓷固定桥的研究进展

    Institute of Scientific and Technical Information of China (English)

    高文玲; 夏海斌; 李智勇

    2008-01-01

    尽管受脆性、抗弯强度和断裂韧性等材料性能的影响,全瓷固定桥目前尚未成为常规的固定修复手段,但其临床应用和研究报道越来越多,并显示出良好的应用前景.本文对硅酸盐陶瓷、玻璃渗透氧化铝陶瓷和氧化锆陶瓷全瓷桥材料的基础研究和临床研究进行了综述.

  15. Preparation of All-Ceramic, High Performance Li-ion Batteries for Deep Space Power Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lithium (Li) ion batteries are among the most promising power sources for many civilian, military and space applications due to their high power and high energy...

  16. Chairside Fabrication of an All-Ceramic Partial Crown Using a Zirconia-Reinforced Lithium Silicate Ceramic

    Science.gov (United States)

    Pabel, Anne-Kathrin; Rödiger, Matthias

    2016-01-01

    The chairside fabrication of a monolithic partial crown using a zirconia-reinforced lithium silicate (ZLS) ceramic is described. The fully digitized model-free workflow in a dental practice is possible due to the use of a powder-free intraoral scanner and the computer-aided design/computer-assisted manufacturing (CAD/CAM) of the restorations. The innovative ZLS material offers a singular combination of fracture strength (>370 Mpa), optimum polishing characteristics, and excellent optical properties. Therefore, this ceramic is an interesting alternative material for monolithic restorations produced in a digital workflow. PMID:27042362

  17. Method of making hermetic seals for hermetic terminal assemblies

    Science.gov (United States)

    Hsu, John S.; Marlino, Laura D.; Ayers, Curtis W.

    2010-04-13

    This invention teaches methods of making a hermetic terminal assembly comprising the steps of: inserting temporary stops, shims and jigs on the bottom face of a terminal assembly thereby blocking assembly core open passageways; mounting the terminal assembly inside a vacuum chamber using a temporary assembly perimeter seal and flange or threaded assembly interfaces; mixing a seal admixture and hardener in a mixer conveyor to form a polymer seal material; conveying the polymer seal material into a polymer reservoir; feeding the polymer seal material from the reservoir through a polymer outlet valve and at least one polymer outlet tube into the terminal assembly core thereby filling interstitial spaces in the core adjacent to service conduits, temporary stop, and the terminal assembly casing; drying the polymer seal material at room temperature thereby hermetically sealing the core of the terminal assembly; removing the terminal assembly from the vacuum chamber, and; removing the temporary stops, shims.

  18. Realization Techniques of Virtual Assembly Process Planning System

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-hua; NING Ru-xin; TANG Cheng-tong

    2005-01-01

    The key realization techniques of virtual assembly process planning (VAPP) system are analyzed,including virtual assembly model, real-time collision detection, automatic constraint recognition algorithm, cable harness assembly process planning and visual assembly process plan at the workshop. A virtual assembly model based on hierarchical assembly task list (HATL) is put forward, in which assembly tasks are defined to express component assembling operations and are sequentially and hierarchically organized according to different subassemblies, which can perfectly model the construction process of product. And a multi-layer automatic geometry constraint recognition algorithm of how to identify assembly constraint relations in the virtual environment is proposed, then a four-layer collision detection algorithm is discussed. A VAPP system is built and some simple mechanical assemblies are used to illustrate the feasibility of the proposed method and algorithms.

  19. RESEARCH ON THE CONSTRAINT MAPPING FROM FUNCTION TO ASSEMBLY

    Institute of Scientific and Technical Information of China (English)

    Tan Jianrong; Ji Yangjian; Liu Zhenyu; Chen Hongliang; Yue Xiaoli

    2003-01-01

    Assembly sketch is not only the visualization of abstract function, but also the template of detail design. Two kinds of information are needed to create assembly sketch: structure and assembly constraint. Most researches are aimed at how to obtain structures from function, but the problem of how to obtain assembly constraint from function is ignored. Following the definition of assembly unit and the classification of function, a hierarchical mapping method from function to assembly constraint is put forward, and the mapping method includes two steps. The first step is the mapping from function to assembly semantics which is assembly expression and accordant with engineer's design habit. The second one is the mapping from assembly semantics to basic assembly constraints that are convenient for computer to handle. The mapping method is applied to DDMS (design, drafting and management system) successfully.

  20. Product-internal assembly functions: a novel micro-assembly concept applied to optical interconnects

    NARCIS (Netherlands)

    Henneken, V.A.

    2008-01-01

    In this project, the technical feasibility of a novel assembly concept was explored, in which microsystem-based self-assembly functionality is added to an existing product. The case considered is the accurate alignment of an optical fibre relative to a telecommunication laser source. In the most dem

  1. A Magnetic Assembly, a Fluid-Flow Assembly and an Indicator

    DEFF Research Database (Denmark)

    2011-01-01

    The invention provides a magnetic assembly, the assembly comprising: a magnet (4); and a ferromagnetic component (6) having at least two regions of different Curie temperature, the magnet (4) and the ferromagnetic component being movable with respect to each other in dependence on the temperature...

  2. Ultrasonic Examination of Jet Pump Diffuser Assemblies

    International Nuclear Information System (INIS)

    In October 1997 the Boiling Water REactor Vessel and Internals Project (BWRVIP) issued the BWR Jet Pump Assembly Inspection and Flaw Evaluation Guidelines (BWRVIP-41). This document identified several welds on the jet pump diffuser assembly that are susceptible to Intergranular Stress Corrosion Cracking (IGSCC) or fatigue, and whose failure could result in jet pump disassembly. Based on the potential for failures, the document recommends inspection of 50% of the high priority welds at the next refueling outage for each BWR, with 100% expansion if flaws are identified. Because each diffuser assembly contains as many as six high priority welds, and access to these welds from the annulus is very restricted, implementing these recommendations can have a significant impact on outage critical path. In an effort to minimize the impact of implementing these recommendations, Framatome Technologies, Inc (FTI) developed a method to perform ultrasonic examinations of the jet pump diffuser assembly welds utilizing remotely operated equipment from the inner diameter (ID) of the diffuser assembly. This paper will discuss the tooling, ultrasonic methods, and delivery techniques used to perform the examinations, as well as the results obtained from a spring 1998 deployment of the system at a U.S. Nuclear Generating Plant. (Author)

  3. Appearance detection device for fuel assembly

    International Nuclear Information System (INIS)

    The present invention concerns a device for detecting the appearance of fuel assemblies for a power plant, in which the device photographs corners of fuel assemblies by a TV-camera to perform detection with higher reliability. Namely, heretofore, fuel assembly to substantially square pillar shape for a BWR and a PWR has been rotated and one or two faces have been detected from the front by the TV-camera. In the present invention, a TV-camera used exclusively for corners is additionally disposed on or near the diagonal line of the corners. With such a constitution, corners of the fuel assemblies can be photographed simultaneously with the conventional appearance test. As a result, since appearance test for the front and the corners can be conducted at the same time, extremely effective detection can be conducted in terms of detection of a rupture of grids and prevention of dead angle. The corners of assemblies which tend to undergo damages upon charge/discharge of fuels can be detected carefully. Accordingly, a highly reliable detection can be conducted. (I.S.)

  4. Self-assembly of smallest magnetic particles.

    Science.gov (United States)

    Mehdizadeh Taheri, Sara; Michaelis, Maria; Friedrich, Thomas; Förster, Beate; Drechsler, Markus; Römer, Florian M; Bösecke, Peter; Narayanan, Theyencheri; Weber, Birgit; Rehberg, Ingo; Rosenfeldt, Sabine; Förster, Stephan

    2015-11-24

    The assembly of tiny magnetic particles in external magnetic fields is important for many applications ranging from data storage to medical technologies. The development of ever smaller magnetic structures is restricted by a size limit, where the particles are just barely magnetic. For such particles we report the discovery of a kind of solution assembly hitherto unobserved, to our knowledge. The fact that the assembly occurs in solution is very relevant for applications, where magnetic nanoparticles are either solution-processed or are used in liquid biological environments. Induced by an external magnetic field, nanocubes spontaneously assemble into 1D chains, 2D monolayer sheets, and large 3D cuboids with almost perfect internal ordering. The self-assembly of the nanocubes can be elucidated considering the dipole-dipole interaction of small superparamagnetic particles. Complex 3D geometrical arrangements of the nanodipoles are obtained under the assumption that the orientation of magnetization is freely adjustable within the superlattice and tends to minimize the binding energy. On that basis the magnetic moment of the cuboids can be explained.

  5. A global assembly of cotton ESTs.

    Science.gov (United States)

    Udall, Joshua A; Swanson, Jordan M; Haller, Karl; Rapp, Ryan A; Sparks, Michael E; Hatfield, Jamie; Yu, Yeisoo; Wu, Yingru; Dowd, Caitriona; Arpat, Aladdin B; Sickler, Brad A; Wilkins, Thea A; Guo, Jin Ying; Chen, Xiao Ya; Scheffler, Jodi; Taliercio, Earl; Turley, Ricky; McFadden, Helen; Payton, Paxton; Klueva, Natalya; Allen, Randell; Zhang, Deshui; Haigler, Candace; Wilkerson, Curtis; Suo, Jinfeng; Schulze, Stefan R; Pierce, Margaret L; Essenberg, Margaret; Kim, Hyeran; Llewellyn, Danny J; Dennis, Elizabeth S; Kudrna, David; Wing, Rod; Paterson, Andrew H; Soderlund, Cari; Wendel, Jonathan F

    2006-03-01

    Approximately 185,000 Gossypium EST sequences comprising >94,800,000 nucleotides were amassed from 30 cDNA libraries constructed from a variety of tissues and organs under a range of conditions, including drought stress and pathogen challenges. These libraries were derived from allopolyploid cotton (Gossypium hirsutum; A(T) and D(T) genomes) as well as its two diploid progenitors, Gossypium arboreum (A genome) and Gossypium raimondii (D genome). ESTs were assembled using the Program for Assembling and Viewing ESTs (PAVE), resulting in 22,030 contigs and 29,077 singletons (51,107 unigenes). Further comparisons among the singletons and contigs led to recognition of 33,665 exemplar sequences that represent a nonredundant set of putative Gossypium genes containing partial or full-length coding regions and usually one or two UTRs. The assembly, along with their UniProt BLASTX hits, GO annotation, and Pfam analysis results, are freely accessible as a public resource for cotton genomics. Because ESTs from diploid and allotetraploid Gossypium were combined in a single assembly, we were in many cases able to bioinformatically distinguish duplicated genes in allotetraploid cotton and assign them to either the A or D genome. The assembly and associated information provide a framework for future investigation of cotton functional and evolutionary genomics. PMID:16478941

  6. Radiological characterization of spent control rod assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Lepel, E.A.; Robertson, D.E.; Thomas, C.W.; Pratt, S.L.; Haggard, D.L. [Pacific Northwest Lab., Richland, WA (United States)

    1995-10-01

    This document represents the final report of an ongoing study to provide radiological characterizations, classifications, and assessments in support of the decommissioning of nuclear power stations. This report describes the results of non-destructive and laboratory radionuclide measurements, as well as waste classification assessments, of BWR and PWR spent control rod assemblies. The radionuclide inventories of these spent control rods were determined by three separate methodologies, including (1) direct assay techniques, (2) calculational techniques, and (3) by sampling and laboratory radiochemical analyses. For the BWR control rod blade (CRB) and PWR burnable poison rod assembly (BPRA), {sup 60}Co and {sup 63}Ni, present in the stainless steel cladding, were the most abundant neutron activation products. The most abundant radionuclide in the PWR rod cluster control assembly (RCCA) was {sup 108m}Ag (130 yr halflife) produced in the Ag-In-Cd alloy used as the neutron poison. This radionuclide will be the dominant contributor to the gamma dose rate for many hundreds of years. The results of the direct assay methods agree very well ({+-}10%) with the sampling/radiochemical measurements. The results of the calculational methods agreed fairly well with the empirical measurements for the BPRA, but often varied by a factor of 5 to 10 for the CRB and the RCCA assemblies. If concentration averaging and encapsulation, as allowed by 10CFR61.55, is performed, then each of the entire control assemblies would be classified as Class C low-level radioactive waste.

  7. [INVITED] Self-assembled optical metamaterials

    Science.gov (United States)

    Baron, Alexandre; Aradian, Ashod; Ponsinet, Virginie; Barois, Philippe

    2016-08-01

    Self-assembled metamaterials constitute a promising platform to achieving bulk and homogenous optical materials that exhibit unusual effective medium properties. For many years now, the research community has contemplated lithographically fabricated metasurfaces, with extraordinary optical features. However, achieving large volumes at low cost is still a challenge by top-down fabrication. Bottom-up fabrication, that relies both on nanochemistry and self-assembly, is capable of building such materials while greatly reducing the energy footprint in the formulation of the metamaterial. Self-assembled metamaterials have shown that they are capable of reaching unprecedented values of bulkiness and homogeneity figures of merit. This feat is achieved by synthesizing plasmonic nanoresonators (meta-atoms in the sense of artificial polarizable units) and assembling them into a fully three-dimensional matrix through a variety of methods. Furthermore it has been shown that a wide range of material parameters can be tailored by controlling the geometry and composition of the meta-atoms as well as the volume fraction of the nano-objects in the metamaterial. Here we conduct a non-comprehensive review of some of the recent trends in self-assembled optical metamaterials and illustrate these trends with our recent work.

  8. Self-Assembly of Tetraphenylalanine Peptides.

    Science.gov (United States)

    Mayans, Enric; Ballano, Gema; Casanovas, Jordi; Díaz, Angélica; Pérez-Madrigal, Maria M; Estrany, Francesc; Puiggalí, Jordi; Cativiela, Carlos; Alemán, Carlos

    2015-11-16

    Three different tetraphenylalanine (FFFF) based peptides that differ at the N- and C-termini have been synthesized by using standard procedures to study their ability to form different nanoassemblies under a variety of conditions. The FFFF peptide assembles into nanotubes that show more structural imperfections at the surface than those formed by the diphenylalanine (FF) peptide under the same conditions. Periodic DFT calculations (M06L functional) were used to propose a model that consists of three FFFF molecules defining a ring through head-to-tail NH3(+)⋅⋅⋅(-)OOC interactions, which in turn stack to produce deformed channels with internal diameters between 12 and 16 Å. Depending on the experimental conditions used for the peptide incubation, N-fluorenylmethoxycarbonyl (Fmoc) protected FFFF self-assembles into a variety of polymorphs: ultra-thin nanoplates, fibrils, and star-like submicrometric aggregates. DFT calculations indicate that Fmoc-FFFF prefers a parallel rather than an antiparallel β-sheet assembly. Finally, coexisting multiple assemblies (up to three) were observed for Fmoc-FFFF-OBzl (OBzl = benzyl ester), which incorporates aromatic protecting groups at the two peptide terminals. This unusual and noticeable feature is attributed to the fact that the assemblies obtained by combining the Fmoc and OBzl groups contained in the peptide are isoenergetic. PMID:26419936

  9. Attomolar DNA detection with chiral nanorod assemblies

    Science.gov (United States)

    Ma, Wei; Kuang, Hua; Xu, Liguang; Ding, Li; Xu, Chuanlai; Wang, Libing; Kotov, Nicholas A.

    2013-10-01

    Nanoscale plasmonic assemblies display exceptionally strong chiral optical activity. So far, their structural design was primarily driven by challenges related to metamaterials whose practical applications are remote. Here we demonstrate that gold nanorods assembled by the polymerase chain reaction into DNA-bridged chiral systems have promising analytical applications. The chiroplasmonic activity of side-by-side assembled patterns is attributed to a 7-9 degree twist between the nanorod axes. This results in a strong polarization rotation that matches theoretical expectations. The amplitude of the bisignate ‘wave’ in the circular dichroism spectra of side-by-side assemblies demonstrates excellent linearity with the amount of target DNA. The limit of detection for DNA using side-by-side assemblies is as low as 3.7 aM. This chiroplasmonic method may be particularly useful for biological analytes larger than 2-5 nm which are difficult to detect by methods based on plasmon coupling and ‘hot spots’. Circular polarization increases for inter-nanorod gaps between 2 and 20 nm when plasmonic coupling rapidly decreases. Reaching the attomolar limit of detection for simple and reliable bioanalysis of oligonucleotides may have a crucial role in DNA biomarker detection for early diagnostics of different diseases, forensics and environmental monitoring.

  10. Solar central receiver heliostat reflector assembly

    Science.gov (United States)

    Horton, Richard H.; Zdeb, John J.

    1980-01-01

    A heliostat reflector assembly for a solar central receiver system comprises a light-weight, readily assemblable frame which supports a sheet of stretchable reflective material and includes mechanism for selectively applying tension to and positioning the sheet to stretch it to optical flatness. The frame is mounted on and supported by a pipe pedestal assembly that, in turn, is installed in the ground. The frame is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e. central receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The frame may include a built-in system for testing for optical flatness of the reflector. The preferable geometric configuration of the reflector is octagonal; however, it may be other shapes, such as hexagonal, pentagonal or square. Several different embodiments of means for tensioning and positioning the reflector to achieve optical flatness are disclosed. The reflector assembly is based on the stretch frame concept which provides an extremely light-weight, simple, low-cost reflector assembly that may be driven for positioning and tracking by a light-weight, inexpensive drive system.

  11. Preparation of the magnet sub-assemblies

    CERN Multimedia

    maximilien Brice

    2001-01-01

    Photo 01: On a rotation bench, preparation of the lower half-yoke with the bus bars and the pre-curved shell. The components are put on a dummy half-yoke in view of being rotated upside down. Photo 02: On a rotation bench, preparation of the lower half-yoke with the bus bars and the pre-curved shell. The components are put on a dummy half-yoke in view of being rotated upside down. Photo 03: The half-yoke assembly is made of short packs that are assembled together and locked with 15-m long tie-rods on a dedicated bench. Photo 04: The collared-coils assembly is equipped with magnetic inserts and special shims on a rotation bench in view of its installation in the yoke, operation that is called "yoking". At that stage of the assembly, the collared-coils assembly is equipped with the end plates and the electrical connections between the poles and between dipole I and dipoe II are made.

  12. Assembling and Installing LRUs for NIF

    Energy Technology Data Exchange (ETDEWEB)

    Bonanno, R E

    2003-12-31

    Within the 192 National Ignition Facility (NIF) beamlines, there are over 7000 large (40 x 40 cm) optical components, including laser glass, mirrors, lenses, and polarizers. These optics are held in large opto-mechanical assemblies called line-replaceable units (LRUs). Each LRU has strict specifications with respect to cleanliness, alignment, and wavefront so that once activated, each NIF beamline will meet its performance requirements. NIF LRUs are assembled, tested, and refurbished in on-site cleanroom facilities. The assembled LRUs weigh up to 1800 kilograms, and are about the size of a phone booth. They are transported in portable clean canisters and inserted into the NIF beampath using robotic transporters. This plug and play design allows LRUs to be easily removed from the beampath for maintenance or upgrades. Commissioning of the first NIF quad, an activity known as NIF Early Light (NEL), has validated LRU designs and architecture, as well as demonstrated that LRUs can be assembled and installed as designed. Furthermore, it has served to develop key processes and tools forming the foundation for NIF s long-term LRU production and maintenance strategy. As we look forward to building out the rest of NIF, the challenge lies in scaling up the production rate while maintaining quality, implementing process improvements, and fully leveraging the learning and experience gained from NEL. This paper provides an overview of the facilities, equipment and processes used to assemble and install LRUs in NIF.

  13. RESEARCH OF MOVEMENT NAVIGATION BASED ON ASSEMBLY CONSTRAINT RECOGNITION

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The requirements and features of virtual assembly movement navigator are analyzed to help operators flexibly manipulate virtual objects, precisely locate or assemble virtual parts in virtual environment. With the degree-of-freedom analysis, the assembly constraint hierarchical model is constructed and the system's constraints are built dynamically. Thus, all objects in virtual environment can be located reasonally by the navigator. Moreover, the assembly constraint recognition in the process of assembly and movement correction is also discussed.

  14. Research overview on vibration damping of mistuned bladed disk assemblies

    OpenAIRE

    Zhang, Liang; Liu, Tiejian; Li, Xin; Xuyao HUO

    2016-01-01

    Bladed disk assemblies are very important parts in auto engine and gas turbine, and is widely used in practical engineering. The mistuning existing commonly in the bladed disk assemblies can destroy the vibration characteristics of the bladed disk assemblies, which is one of the reasons for the high cycle fatigue failure of bladed disk assemblies, so it is necessary to research how to reduce the vibration of the bladed disk assemblies. On the basis of the review of relevant research at home a...

  15. DETERMINANTS OF THE HIV-1 CORE ASSEMBLY PATHWAY

    OpenAIRE

    López, Claudia S.; Eccles, Jacob D.; Still, Amelia; Sloan, Rachel E.; Barklis, Robin Lid; Tsagli, Seyram M.; Barklis, Eric

    2011-01-01

    Based on structural information, we have analyzed the mechanism of mature HIV-1 core assembly and the contributions of structural elements to the assembly process. Through the use of several in vitro assembly assay systems, we have examined details of how capsid (CA) protein helix 1, β-hairpin and cyclophilin loop elements impact assembly-dependent protein interactions, and we present evidence for a contribution of CA helix 6 to the mature assembly-competent conformation of CA. Additional exp...

  16. Fe-S Cluster Assembly Pathways in Bacteria

    OpenAIRE

    Ayala-Castro, Carla; Saini, Avneesh; Outten, F. Wayne

    2008-01-01

    Summary: Iron-sulfur (Fe-S) clusters are required for critical biochemical pathways, including respiration, photosynthesis, and nitrogen fixation. Assembly of these iron cofactors is a carefully controlled process in cells to avoid toxicity from free iron and sulfide. Multiple Fe-S cluster assembly pathways are present in bacteria to carry out basal cluster assembly, stress-responsive cluster assembly, and enzyme-specific cluster assembly. Although biochemical and genetic characterization is ...

  17. Nuclear fuel assembly top nozzle with improved arrangement of hold-down leaf spring assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, C.N.

    1991-06-26

    A fuel assembly has a top nozzle which includes a lower adapter plate and a plurality of guide structures which are attached to an extend along the periphery of the lower plate and upwardly therefrom. The top nozzle also includes an upper hold-down plate supported by a plurality of leaf spring assemblies. The upper plate is mounted to the guide structures for vertical slidable movement relative thereto. The leaf spring assemblies are provided in a non-peripheral arrangement relative to the periphery of the lower plate in which the assemblies are provided in a non-peripheral arrangement relative to the periphery of the lower plate in which the assemblies cross the interior of the lower plate in a diagonal fashion between adjacent ones of the guide structures. (author).

  18. Agents, assemblers, and ANTS: scheduling assembly with market and biological software mechanisms

    Science.gov (United States)

    Toth-Fejel, Tihamer T.

    2000-06-01

    Nanoscale assemblers will need robust, scalable, flexible, and well-understood mechanisms such as software agents to control them. This paper discusses assemblers and agents, and proposes a taxonomy of their possible interaction. Molecular assembly is seen as a special case of general assembly, subject to many of the same issues, such as the advantages of convergent assembly, and the problem of scheduling. This paper discusses the contract net architecture of ANTS, an agent-based scheduling application under development. It also describes an algorithm for least commitment scheduling, which uses probabilistic committed capacity profiles of resources over time, along with realistic costs, to provide an abstract search space over which the agents can wander to quickly find optimal solutions.

  19. Assembly and Assessment of DNA Scaffolded Vaccines.

    Science.gov (United States)

    Liu, Xiaowei; Wang, Lili; Yan, Hao; Chang, Yung

    2016-01-01

    Vaccines play an important role in preventing many life-threatening infectious diseases. To meet the demand of vaccination for treating a wide range of diseases, rational vaccine design has been recognized as a desirable and necessary strategy for development of safe and effective vaccines. DNA nanostructures are advantageous in the design and construction of synthetic vaccines, owing to their robust self-assembly, programmability, and precision control in complex organization, as well as their intrinsic adjuvant activity. Here, we describe a modular assembly of DNA scaffolded vaccine complex, composing of a model antigen, streptavidin, and adjuvant, CpG oligonucleotide. The DNA-assembled vaccines were found to elicit strong antigen-specific antibody responses, but causing little or no adverse reactions. Conceivably, this vaccine platform can be further optimized for improved immunogenicity and extended to the construction of various subunit vaccines. PMID:27076307

  20. Hierarchical silica particles by dynamic multicomponent assembly

    DEFF Research Database (Denmark)

    Wu, Z. W.; Hu, Q. Y.; Pang, J. B.;

    2005-01-01

    Abstract: Aerosol-assisted assembly of mesoporous silica particles with hierarchically controllable pore structure has been prepared using cetyltrimethylammonium bromide (CTAB) and poly(propylene oxide) (PPO, H[OCH(CH3)CH2],OH) as co-templates. Addition of the hydrophobic PPO significantly...... influences the delicate hydrophilic-hydrophobic balance in the well-studied CTAB-silicate co-assembling system, resulting in various mesostructures (such as hexagonal, lamellar, and hierarchical structure). The co-assembly of CTAB, silicate clusters, and a low-molecular-weight PPO (average M-n 425) results...... in a uniform lamellar structure, while the use of a high-molecular-weight PPO (average M-n 2000), which is more hydrophobic, leads to the formation of hierarchical pore structure that contains meso-meso or meso-macro pore structure. The role of PPO additives on the mesostructure evolution in the CTAB...