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Добірка наукової літератури з теми "FpDBS"

Автор: Grafiati

Опубліковано: 11 березня 2023

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Статті в журналах з теми "FpDBS"

Bertaso, Anna, Daniela Sorio, Anthula Vandoros, Elio F. De Palo, Federica Bortolotti, and Franco Tagliaro. "Use of finger-prick dried blood spots (fpDBS) and capillary electrophoresis for carbohydrate deficient transferrin (CDT) screening in forensic toxicology." ELECTROPHORESIS 37, no. 21 (June 7, 2016): 2867–74. http://dx.doi.org/10.1002/elps.201500588.

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Modi, Ritesh, Shivani Kohli, K. Rajeshwari, and Shekhar Bhatia. "A three-dimension finite element analysis to evaluate the stress distribution in tooth supported 5-unit intermediate abutment prosthesis with rigid and nonrigid connector." European Journal of Dentistry 09, no. 02 (April 2015): 255–61. http://dx.doi.org/10.4103/1305-7456.156847.

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ABSTRACT Objective: The aim of the study is to evaluate the stress distribution in tooth supported 5-unit fixed partial denture (FPD) having tooth as pier abutment using rigid and nonrigid connectors respectively, under simultaneous and progressive loading. Material and Methods: The three-dimensional (3D) finite element program (ANSYS software) was used to construct the mathematical model. Two 5-unit FPD'S were simulated, one with rigid connector and another one with nonrigid connector. For analysis, each of these models were subjected to axial and oblique forces under progressive loading (180, 180, 120, 120, 80 N force on first and second molars, premolars and canine respectively) and simultaneous loading (100, 100, 100, 100, 100 N force on first and second molars, premolars and canine respectively). Results: The rigid and nonrigid connector design have effect on stress distribution in 5-unit FPDs with pier abutments. Conclusion: Oblique forces produce more stresses than vertical forces. Nonrigid connector resulted in decrease in stress at the level of prosthesis and increase in stress at the level of alveolar crest.

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Liu, Kang, Yan Li, Wu Zhao, and Wen Qiang Li. "Research of Ontology Based FPBS Design Model." Applied Mechanics and Materials 275-277 (January 2013): 2595–600. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.2595.

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The conceptual design model for mechanical product and its computer aided design are the important and focus problems. A mechanical product design process of FPBS model, function-principle-behavior-structure model, was put forward and discussed. The semantic relationships between the elements of FPBS model were studied to make foundation for the application of FPBS model. The operational demand of knowledge system for FPBS model was analyzed, and indicates the ontology can be applied effectively to knowledge system operation of FPBS model. Then, an ontology based FPBS model was established and a FPBS ontology model system was constructed. The experimental results indicate the model can be used in computer aided conceptual design for mechanical product effectively.

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Abdulaziz, O., I. Hashim, and A. Saif. "Series Solutions of Time-Fractional PDEs by Homotopy Analysis Method." Differential Equations and Nonlinear Mechanics 2008 (2008): 1–16. http://dx.doi.org/10.1155/2008/686512.

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The homotopy analysis method (HAM) is applied to solve linear and nonlinear fractional partial differential equations (fPDEs). The fractional derivatives are described by Caputo's sense. Series solutions of the fPDEs are obtained. A convergence theorem for the series solution is also given. The test examples, which include a variable coefficient, inhomogeneous and hyperbolic-type equations, demonstrate the capability of HAM for nonlinear fPDEs.

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Cristea, Ioana, Doriana Agop-Forna, Maria-Alexandra Martu, Cristina Dascălu, Claudiu Topoliceanu, Roland Török, Bianca Török, Dimitrios Bardis, Panagiota Moulavasili Bardi, and Norina Forna. "Oral and Periodontal Risk Factors of Prosthetic Success for 3-Unit Natural Tooth-Supported Bridges versus Implant-Supported Fixed Dental Prostheses." Diagnostics 13, no. 5 (February 23, 2023): 852. http://dx.doi.org/10.3390/diagnostics13050852.

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The goals of this research are: (1) to compare the survival and prosthetic success of metal-ceramic 3-unit tooth- versus implant-supported fixed dental prostheses; (2) to evaluate the influence of several risk factors on the prosthetic success of tooth- and implant-supported fixed dental prostheses (FPDs). A total of 68 patients with posterior short edentulous spaces (mean age 61.00 ± 1.325 years), were divided into two groups: 3-unit tooth-supported FPDs (40 patients; 52 FPD; mean follow-up 10.27 ± 0.496 years) and 3-unit implant-supported FPDs (28 patients; 32 FPD; mean follow-up 8.656 ± 0.718 years). Pearson-chi tests were used to highlight the risk factors for the prosthetic success of tooth- and implant-supported FPDs and multivariate analysis was used to determine significant risk predictors for the prosthetic success of the tooth-supported FPDs. The survival rates of 3-unit tooth- versus implant-supported FPDs were 100% and 87.5%, respectively, while the prosthetic success was 69.25% and 68.75%, respectively. The prosthetic success of tooth-supported FPDs was significantly higher for patients older than 60 years (83.3%) vs. 40–60 years old (57.1%) (p = 0.041). Periodontal disease history decreased the prosthetic success of tooth- versus implant-supported FPDs when compared with the absence of periodontal history (45.5% vs. 86.7%, p = 0.001; 33.3% vs. 90%, p = 0.002). The prosthetic success of 3-unit tooth- vs. implant-supported FPDs was not significantly influenced by gender, location, smoking, or oral hygiene in our study. In conclusion, similar rates of prosthetic success were recorded for both types of FPDs. In our study, prosthetic success of tooth- versus implant-supported FPDs was not significantly influenced by gender, location, smoking, or oral hygiene; however, history of periodontal disease is a significant negative predictor of success in both groups when compared with patients without periodontal history.

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Piovesan, Edno Moacir, Flávio Fernando Demarco, and Evandro Piva. "Fiber-reinforced fixed partial dentures: a preliminary retrospective clinical study." Journal of Applied Oral Science 14, no. 2 (April 2006): 100–104. http://dx.doi.org/10.1590/s1678-77572006000200007.

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The aim of this study was to evaluate the clinical performance (retention rate) of fiber-reinforced composite fixed partial dentures (FPDs). Polyethylene fiber (Ribbond®) was used combined with restorative composite during FPDs fabrication. FPDs were placed in thirteen patients in a private clinic. Nineteen FPDs were evaluated. The prosthetic space was filled with only one pontic using extracted teeth (2 cases), acrylic resin teeth (11 cases), or with composite resin (6 cases), combined with Polyethylene fiber. The clinical criterion used was based on retention rate of FPDs. If FPDs were in function in the mouth at the time of examination without previous repair they were classified as Complete Survival (CS) restorations. A classification of Survival with Rebonding (SR) was assigned in the event of an adhesive failure, but after rebonding the FPD still remained under evaluation. Treatment was classified as a Failure (F) if the FPD restoration was lost. The time of evaluation was 41.15 months (±15.13). The FPDs evaluated were retained (CS=94.75%), and no failure was found except for in one situation which required rebonding (SR=5.25%). According to the survival estimation method of Kaplan-Meyer the mean survival time was 42.3 months. At the time of evaluation investigated, polyethylene-reinforced FPDs showed a favorable retention rate in preliminary data.

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Kim, Jeongah, Bo-Young Kim, Seong Dae Park, Ji-Hun Seo, Chan-Jae Lee, Myong Jae Yoo, and Youngmin Kim. "Mechanical Durability of Flexible Printed Circuit Boards Containing Thin Coverlays Fabricated with Poly(Amide-Imide-Urethane)/Epoxy Interpenetrating Networks." Micromachines 12, no. 8 (August 10, 2021): 943. http://dx.doi.org/10.3390/mi12080943.

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Because electronics are becoming flexible, the demand for techniques to manufacture thin flexible printed circuit boards (FPCBs) has increased. Conventional FPCBs are fabricated by attaching a coverlay film (41 μm) onto copper patterns/polyimide (PI) film to produce the structure of coverlay/Cu patterns/PI film. Given that the conventional coverlay consists of two layers of polyimide film and adhesive, its thickness must be reduced to generate thinner FPCBs. In this study, we fabricated 25-μm-thick poly(amide-imide-urethane)/epoxy interpenetrating networks (IPNs) to replace the thick conventional coverlay. Poly(amide-imide-urethane) (PAIU) was synthesized by reacting isocyanate-capped polyurethane with trimellitic anhydride and then mixed with epoxy resin to produce PAIU/epoxy IPNs after curing. Thanks to the soft segments of polyurethane, the elongation of PAIU/epoxy IPNs increased with increasing PAIU content and reached over 200%. After confirming the excellent thermal stability and chemical resistance of the PAIU/epoxy IPNs, we fabricated FPCBs by equipping them as coverlays. The mechanical durability of the FPCBs was evaluated through an MIT folding test, and the FPCB fabricated with PAIU/ep-2 was stable up to 164 folding cycles because of the balanced mechanical properties.

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Zhao, Jingjun, Jingyu Xiao, and Yang Xu. "Stability and Convergence of an Effective Finite Element Method for Multiterm Fractional Partial Differential Equations." Abstract and Applied Analysis 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/857205.

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A finite element method (FEM) for multiterm fractional partial differential equations (MT-FPDEs) is studied for obtaining a numerical solution effectively. The weak formulation for MT-FPDEs and the existence and uniqueness of the weak solutions are obtained by the well-known Lax-Milgram theorem. The Diethelm fractional backward difference method (DFBDM), based on quadrature for the time discretization, and FEM for the spatial discretization have been applied to MT-FPDEs. The stability and convergence for numerical methods are discussed. The numerical examples are given to match well with the main conclusions.

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De Angelis, Paolo, Giulio Gasparini, Francesca Camodeca, Silvio De Angelis, Margherita Giorgia Liguori, Edoardo Rella, Francesca Cannata, Antonio D’Addona, and Paolo Francesco Manicone. "Technical and Biological Complications of Screw-Retained (CAD/CAM) Monolithic and Partial Veneer Zirconia for Fixed Dental Prostheses on Posterior Implants Using a Digital Workflow: A 3-Year Cross-Sectional Retrospective Study." BioMed Research International 2021 (July 6, 2021): 1–9. http://dx.doi.org/10.1155/2021/5581435.

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Objective. The introduction of CAD/CAM and the development of zirconia-based restorations have allowed clinicians to use less expensive materials and faster manufacturing procedures. The purpose of the study was to analyze the differences, in terms of mechanical and biological complication, in multiunit zirconia fixed dental prosthesis (FPDs) on posterior implants produced using a digital workflow. Method and Materials. This study was a retrospective investigation, and patients treated with screw-retained monolithic or partial veneer FPDs on dental implants were selected. Periapical radiographs were taken at baseline and at the 3-year follow-up. Complications were recorded and classified as technical and biological ones. Results. The study population included 25 patients. The occlusal and interproximal corrections were not clinically significant. In the study sample, the survival rate and success rate of the FPDs after 3 years were 100% and 96%, respectively. One implant failed immediately after placement. Conclusion. Monolithic zirconia FPDs and partial veneer FPDs showed a 100% survival rate, presenting an interesting alternative to metal ceramic restorations. The partial veneer FPDs had a higher technical complication rate than the monolithic FPDs; however, no statistically significant difference was found.

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Arruda, Luciano, Cristiano Coimbra, and João Marco Andolfatto. "Direct and Indirect Strain Measurement of Flexible Printed Circuit Boards - fPCBs." Advanced Materials Research 655-657 (January 2013): 88–93. http://dx.doi.org/10.4028/www.scientific.net/amr.655-657.88.

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This work is related to reliability of strain measurement in flexible printed circuit boards (fPCBs) made with polyimide substrate. It was observed that the fPCBs are very sensitive to strain mounting stiffness. The indirect measurement method will be done employing High Speed Camera (HSP). The direct method will be formulated in two ways: 1) conventional strain gauge glued in an fPCBs; 2) printed strain gauge in a polyimide substrate. This paper will point out mistakes and show advantages when using different method to extract the deformation field of the selected area in a flexible thin film.

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Дисертації з теми "FpDBS"

CAVALLINI, MARCO. "Nuove strategie analitiche per la prevenzione degli incidenti stradali alcol correlati nei conducenti di autobus." Doctoral thesis, 2017. http://hdl.handle.net/11562/963373.

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Road accidents and accidents at work are among the most important causes of death or disability in Western Countries. In Europe alcohol has been linked to 25% of road deaths, killing about 10.000 people a year. In Italy, according to data collected by the Istituto Superiore di Sanità, more than 30% of fatal or serious traffic accidents are caused by the consumption of alcoholic beverages. Although the correlation between acute alcohol intoxication and driving disability is well known since ‘70s, to the best of our knowledge, there are no studies on the correlation between chronic alcohol abuse and risk of work accidents under the influence of alcohol. The main objectives of the study were: • to implement novel analytical strategies to be applied in the specific field of workplace safety assessment; • to study the prevalence of chronic alcohol abuse in a population of bus drivers; The experimental work was a part of a 5 years longitudinal study involving the bus drivers of the Verona Public Transportation Company (ATV). In the frame of workplace safety assessment, these subjects underwent once/year medical examination and blood sampling for the determination of CDT and γGT. The determination of γGT was performed by using an immunometric method (Beckman Coulter), while CDT analysis was carried out by a validated HPLC method. In addition a CZE-UV method for CDT determination in finger prick Dried Blood Spot was developed (fpDBS). CDT value was expressed as a percentage ratio of the sum of CDT correlated glycoforms (asialo and disialo-tf) on the total transferrin. The CDT cut-off value to distinguish between “normal subjects” and “alcohol abusers” was fixed at 1,90%. The normal γGT values are within 50 U/L for males and 38 U/L for females. In the year 2014-2016, 1827 subjects were examined: 501 in 2014, 629 in 2015 and 697 in 2016. 1314 (71%) out of them underwent the blood collection by venipuncture, the remaining part underwent the blood collection by fpDBS. Every year, about 2% of the subjects showed CDT values above the cut-off (1.90%) suggesting a condition of chronic alcohol abuse. In addition, about 15% of the subjects showed γGT values above the cut-off (females: 38 U/L; males: 50 U/L). The γGT data looked more difficult to be interpreted in comparison to CDT data since γGT increases also for pathological conditions different from alcohol abuse.

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LI, YAO-NAN, and 李耀南. "Furniture pictorial database and layout system (FPDLS)." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/43202860799633663668.

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Huang, Nan-Chieh, and 黃南傑. "Effect of fiber framework designs on the fracture load of glass fiber-reinforced acrylic provisional FPDs." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/49947356870223812306.

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碩士
高雄醫學大學
牙醫學研究所
97
Objectives: The aim of this study was to evaluate the effect of fiber framework designs on the initial and final fracture loads of glass fiber-reinforced acrylic provisional fixed partial dentures (FPDs). Materials & Methods: A total of 105 standardized mandibular four-units Poly Methyl Methacrylate (PMMA) FPDs were fabricated. The stainless steel mandibular first premolar and first molar were as abutments. The specimens were divided into S-glass fiber Fibrekor®(F) and E-glass fiber Stick®(S) groups, and each group was divided into 3 subgroups(each n=15) according to fiber length and fiber framework designs. Subgroup 1B, two bundles of 1 cm length fiber in connector between pontics (Bar type); subgroup 3H, two bundles of 3cm length fibers are parallel between abutments (H type); subgroup 3X, two bundles of 3 cm fibers are cross between abutments (X type). Unreinforced specimens served as the control. After thermal cycling (600*5℃/55℃, 2 min/cycle), the specimens were temporarily fixed with provisional cement (Temp Bond) on the stainless steel abutments. All FPDs were subjected to load with a 6mm steel ball on the middle fossa of first molar pontic by a universal testing machine (5mm/min). The acoustic emission (AE) signals were used to detect initial fracture point and measured as initial fracture load. The final fracture load and fracture patterns were recorded when FPDs were totally fractured. The initial and final fracture load were analyzed using analysis of variance (ANOVA, One-way, Two-way with cross effect) and Tukey’s method (α=.05). The fracture patterns were analyzed using χ2 test for trend. Results: Mean initial fracture load varied from 333.1N (S1B) to 556.6N (S3H). Mean final fracture load varied from 626.2N (Control) to 1078.9N (S3H). Significant differences were identified between each group (P<.001). The initial and final fracture load of reinforced groups were found statistically significantly influenced by fiber framework designs (P<.001, P<.0001, respectively), whereas no significant difference was indicated between Fibrekor® and Stick® glass fibers. The fracture patterns of reinforced specimens were significantly changed from catastrophic fracture to bended or partial fracture. Conclusion: This study revealed that glass fiber can improve initial and final fracture load and change fracture patterns of acrylic provisional FPDs. The reinforcing effect was mainly influenced by different fiber framework designs, and H type has the highest fracture load.

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Книги з теми "FpDBS"

United States. General Services Administration and Federal Procurement Data Center (U.S.), eds. FPDS-- the competitor's edge. Washington, D.C. (7th and D Sts., SW, Rm. 5652, Washington 20407): U.S. General Services Administration, Federal Procurement Data Center, 1994.

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Roefi'ie, Masduki. Evaluasi efektivitas perkuliahan FPBS, FPMIPA, FPTK IKIP Surabaya semester genap 1995/1996: Laporan penelitian. [Surabaya]: Departemen Pendidikan dan Kebudayaan, Institut Keguruan dan Ilmu Pendidikan Surabaya, Lembaga Penelitian, 1996.

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Ano, Karsana, ed. Lir cahya nyorot eunteung: Cipta sastra warga Jurusan Pendidikan Bahasa Daerah (Sunda), FPBS, Universitas Pendidikan Indonesia. Bandung: Sonagar Press, 2008.

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Mengapa musik tradisional terpinggirkan?: Studi latar belakang mahasiswa program studi pendidikan seni musik, Jurusan Sendratasik FPBS IKIP Bandung : laporan penelitian. Bandung: Jurusan Pendidikan Bahasa Inggeris, Fakultas Pendidikan Bahasa dan Seni, Institut Keguruan dan Ilmu Pendidikan, 1997.

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Indonesia) Seminar dan Musda Guru/Alumni Seni Rupa dan Kerajinan se-Sumatera Barat (1st 1989 Padang. Kumpulan makalah seminar pendidikan dan pengajaran seni rupa dalam rangka HUT ke 26, Jurusan Pendidikan Seni Rupa dan Kerajinan, FPBS IKIP Padang. Padang: Jurusan Pendidikan Seni Rupa dan Kerajinan FPBS IKIP Padang, 1989.

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Suryatna, Ayat. Laporan penelitian makna reformasi bagi mahasiswa IKIP Bandung: Studi kasus mengenai aksi demonstrasi, corat-coret, dan dialog terbuka mahasiswa Jurusan Pendidikan Seni Rupa FPBS IKIP Bandung. [Bandung]: Fakultas Pendidikan Bahasa dan Seni, Institut Keguruan dan Ilmu Pendidikan Bandung, 1998.

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Kuswari, Usep. Model tes profisiensi bahasa Sunda: Studi deskriptif pada mahasiswa Program Studi Pendidikan Bahasa Sunda, FPBS, Universitas Pendidikan Indonesia tahun akademik 2001/2002 : laporan penelitian dosen muda. Bandung: Jurusan Pendidikan Bahasa Daerah, Fakultas Pendidikan Bahasa dan Seni, Universitas Pendidikan Indonedia [i.e. Indonesia], 2002.

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Wahyu, Ucu. Hubungan antara kemampun membaca pemahaman dengan prestasi belajar: Studi deskriptif pada mahasiswa Jurusan Pendidikan Bahasa Daerah, FPBS Universitas Pendidikan Indonesia tahun 1999/2000 : laporan hasil penelitian mandiri. Bandung: Jurusan Pendidikan Bahasa Daerah, Fakultas Pendidikan Bahasa dan Seni, Universitas Pendidikan Indonesia, 1999.

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Danasasmita, Wawan. Hubungan antara sikap terhadap bahasa Jepang dengan prestasi belajar: Studi deskriptif analitis pada mahasiswa Program Studi Pendidikan Bahasa Jepang, FPBS, UPI Bandung, Tingkat I semester ganjil 1999/2000 : laporan hasil penelitian hibah bersaing dana rutin. Bandung: Program Pendidikan Bahasa Jepang, Jurusan Pendidikan Bahasa Asing, Fakultas Pendidikan Bahasa dan Seni, Universitas Pendidikan Indonesia, 2000.

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[OMB and GSA: FPDS improvements]. Washington, D.C: The Office, 1994.

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Частини книг з теми "FpDBS"

Prakash, Ch, A. K. Sharma, and P. C. Rastogi. "Diagnosis of cast-in-situ piles resting on rock by FPDS." In Application of Stress-Wave Theory to Piles, 305–10. London: Routledge, 2022. http://dx.doi.org/10.1201/9781315137544-43.

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Тези доповідей конференцій з теми "FpDBS"

Li, Zhigang, Jun Li, and Zhenping Feng. "Numerical Investigations on the Leakage and Rotordynamic Characteristics of Pocket Damper Seals: Part II — Effects of Partition Wall Type, Partition Wall Number and Cavity Depth." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-25301.

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Effects of partition wall type, partition wall number and cavity depth on the leakage and rotordynamic characteristics of the pocket damper seal (PDS) were numerically investigated using a presented 3D transient CFD method based on the multi-frequency elliptical whirling orbit model. The accuracy and availability of this transient CFD method and the multi-frequency elliptical whirling orbit model were demonstrated with the experimental data of the experimental eight-bladed fully-partitioned pocket damper seal (FPDS). The leakage flow rates and frequency-dependent rotordynamic coefficients of PDS were computed for two types of partition wall (namely conventional PDS and fully-partitioned PDS), four partition wall numbers including the labyrinth seal (no partition wall) and six cavity depths including the plain smooth seal (zero cavity depth) at operational conditions with or without inlet preswirl and 15000rpm rotational speed. The numerical results show that the FPDS has the similar leakage performance and more superior stability capacity than the conventional PDS. The FPDS possesses slightly larger leakage flow rate (∼2.6–4.0% larger) compared to the labyrinth seal. Eight is a preferable value for the partition wall number to gain the best leakage performance of the FPDS with the least manufacturing cost. The FPDS possesses significantly larger stiffness and damping than the labyrinth seal. Increasing partition wall number results in a significant increase in the direct stiffness but limited desirable effect on the effective damping. The FPDS possesses the lowest leakage flow rate when the cavity depth is about 2.0mm. Compared to the plain smooth seal, the FPDS possesses larger positive direct stiffness and significantly less direct damping and effective damping. Increasing cavity depth results in a significant decrease in the stabilizing direct damping and the magnitude of the destabilizing cross-coupling stiffness. H = 3.175mm is a preferable value of the cavity depth for which the effective damping of the FPDS is largest, especially for the concerned frequencies (80–120Hz) where most multistage high-pressure centrifugal compressors have stability problem.

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Delgado, Adolfo, Luis San Andrés, Jing Yang, and Jonathan Thiele. "Experimental Force Coefficients for a Fully-Partitioned Pocket Damper Seal and Comparison to Other Two Seal Types." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-83164.

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Abstract Labyrinth seals (LS), honeycomb seals (HCS) and hole-pattern seals, pocket damper seals (PDS) and fully-partitioned damper seals (FPDS) serve as balance pistons on the discharge side of barrel type centrifugal compressors. These seals, facing large pressure differentials along with significant changes in gas density, produce sizeable lateral forces that impact compressor stability and its rotordynamic performance. There is extensive archival data on the dynamic forced performance of LS and textured surface seals. However, the experimental database for a FPDS is insufficient, thus a comprehensive comparison of their dynamic force performance against that of textured surface seals is missing. The paper presents experimentally derived rotordynamic force coefficients for a FPDS along with a direct comparison to published data for an HCS and a LS, both similar in size and in operating conditions. The dynamic load tests with the FPDS include operation at a shaft speed (Ω) of 10 krpm (rotor surface speed of 60 m/s) while supplied with air at Pin = 70 bar and Tin =10 °C, and a discharge at Pout = 0.25, 0.5, and 0.65 of Pin. The pre-swirl circumferential velocity at the seal inlet is low, approximately 6% of rotor surface speed. The FPDS having eight pockets × eight axial blades produces a direct stiffness (K) increasing with excitation frequency (ω), though K < 0 for the lowest pressure ratio PR = (Pout/Pin) = 0.25. The cross-coupled stiffness (k) is invariant to frequency whereas the direct damping (C) steadily decreases as ω/Ω → 1, and then increases for larger frequencies. Hence, the effective damping coefficient (Ceff = C – k/ω) is approximately constant for ω < Ω, while increasing for higher frequencies. For the three PRs, the FPDS leakage is roughly up to 26% larger than the HCS leakage, while the 20-blade LS leaks in between both. The comparison of results shows the LS has insignificant forces compared to those from the HCS and FPDS, both producing a comparable Ceff and similar crossover frequencies (Ceff > 0). The HCS produces a large direct stiffness (K), three to four times that from the FPDS. Comparison of CFD predictions for the FPDS against the experimental force coefficients shows significant differences, in particular an over estimation of direct stiffness as the frequency grows along with a lower direct damping for frequencies equal and above the shaft speed. Besides manufacturing considerations, a FPDS is a better alternative to an HCS whose large centering stiffness (K) may affect the compressor critical speed, hence shortening the separation margin with respect to the operating speed.

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Wu, Guang-Min, and Yao-Wen Chang. "Switch-matrix architecture and routing for FPDs." In the 1998 international symposium. New York, New York, USA: ACM Press, 1998. http://dx.doi.org/10.1145/274535.274559.

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Zachery, Karen N., Gregory M. Schultz, and Leslie M. Collins. "Force protection demining system (FPDS) detection subsystem." In Defense and Security, edited by Russell S. Harmon, J. Thomas Broach, and John H. Holloway, Jr. SPIE, 2005. http://dx.doi.org/10.1117/12.603021.

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Li, Zhigang, Jun Li, and Zhenping Feng. "Numerical Investigations on the Leakage and Rotordynamic Characteristics of Pocket Damper Seals: Part I — Effects of Pressure Ratio, Rotational Speed and Inlet Preswirl." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-25300.

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Effects of pressure ratio, rotational speed and inlet preswirl on the leakage and rotordynamic characteristics of a eight-bladed fully-partitioned pocket damper seal (FPDS) were numerically investigated using proposed 3D transient CFD methods based on the multi-frequency elliptical whirling orbit model. The accuracy and availability of the multi-frequency elliptical whirling orbit model and the transient CFD numerical methods were demonstrated with the experimental data of frequency-dependent rotordynamic coefficients of the FPDS at two rotational speeds with high preswirl conditions. The frequency-dependent rotordynamic coefficients of the FPDS at three pressure ratios (three inlet pressures and three outlet pressures), three rotational speeds, three inlet preswirls were computed. The numerical results show that changes in outlet pressure have only weak effects on most rotordynamic coefficients. The direct damping and effective damping slightly increase in magnitude with decreasing outlet pressure at the frequency range of 20–200Hz. The effect of inlet pressure is most prominent, and increasing inlet pressure for the FPDS results in a significant increase in the magnitudes of all rotordynamic coefficients. The magnitudes of the seal response force and effective damping are proportional to pressure drop through the seal. Increasing rotational speed and increasing inlet preswirl velocity both result in a significant decrease in the effective damping term due to the obvious increase in the magnitude of the destabilizing cross-coupling stiffness with increasing rotational speed or increasing preswirl velocity. The crossover frequency of effective damping significantly increases and the peak magnitude of effective damping decreases with increasing rotational speed or increasing preswirl velocity. The destabilizing cross-coupling stiffness is mainly caused by the circumferential swirl velocity generating from high rotational speed and inlet preswirl. Reducing swirl velocity (such as swirl brake) can greatly enhance the stabilizing capacity of the FPDS.

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Agnew, Jeff, and Dara Childs. "Rotordynamic Characteristics of a Flexure Pivot Pad Bearing With an Active and Locked Integral Squeeze Film Damper." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-68564.

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Measured rotordynamic coefficients are presented for a flexure-pivot-pad journal bearing (FPJB) in a load-between-pad configuration with: (1) an active, and (2) locked integral squeeze film damper (ISFD). Prior rotordynamic-coefficient test results have been presented for FPJBs (alone), and rotor-response results have been presented for rotors supported by FPJBS with ISFDs; however, these are the first rotordynamic-coefficient test results for FPJBs with ISFDs. A multi-frequency dynamic testing regime is employed. For both bearing configurations, quadratic curve fits provide good representation of the real portions of the dynamic-stiffness coefficients yielding a direct stiffness and a direct added-mass coefficient. The imaginary portions are well represented by linear curve fits, implying constant, frequency-independent direct-damping coefficients. Direct stiffness coefficients are ∼50% lower for the active-damper configuration, and direct damping coefficients are only modestly lower. The combination of ∼50% reduction in direct stiffness with a modest drop in direct damping indicates a very effective squeeze-film damper application. Added-mass coefficients are normally lower for the active-damper configuration, and all coefficient trends (for changes in loading and shaft speed) are “flatter” for the active flexure pivot-pad damper bearing. The measured rotordynamic coefficients are used to calculate the whirl frequency ratio and indicate high stability for both bearing configurations.

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Sola, Kenneth E. "Six success stories for FPDs in military platforms." In AeroSense '99, edited by Darrel G. Hopper. SPIE, 1999. http://dx.doi.org/10.1117/12.357613.

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Vincen, Mark R. "History and analysis of FPDs for the automobile." In AeroSense 2000, edited by Darrel G. Hopper. SPIE, 2000. http://dx.doi.org/10.1117/12.397773.

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Okumura, H. "Image compression if technologies for low power FPDs." In 2014 IEEE International Conference on Consumer Electronics (ICCE). IEEE, 2014. http://dx.doi.org/10.1109/icce.2014.6775915.

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Meng, Lin, Keisuke Matsuyama, Naoto Nojiri, Tomonori Izumi, and Katsuhiro Yamazaki. "Pipelining FPPGA-based defect detction in FPDs (abstract only)." In FPGA'14: The 2014 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays. New York, NY, USA: ACM, 2014. http://dx.doi.org/10.1145/2554688.2554729.

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