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Surface Configurations (surface + configuration)
Selected AbstractsEffects of molding conditions on transcription molding of microscale prism patterns using ultra-high-speed injection moldingPOLYMER ENGINEERING & SCIENCE, Issue 9 2006H. Yokoi In this study, we performed a series of molding tests to investigate the potential of microscale transcription of polymer by ultra-high-speed injection molding (UHSIM). During the tests, the injection speed was varied up to a maximum of 995 mm/s. Polymethyl methacrylate was molded under various injection molding conditions, including cavity vacuum pumping process, so as to replicate an electroformed nickel stamper exhibiting V-grooves with a pitch of 50 ,m. Surface configurations of molded samples were observed and measured using a laser scanning microscope. The transcription ratio (TR) is defined as the ratio of the depths of V-grooves in both the molded samples and the stamper. An excellent average TR of 0.97 was performed when molding at an injection rate of 800 cm3/s (injection speed of 995 mm/s), mold temperature of 80°C, and holding pressure of 120 MPa. In addition, the effect of vacuum on transcription molding was investigated in detail; the result proved that vacuum is an important factor in the enhancement of transcription fidelity. The strong influence of injection rate on the TR indicates the applicability of UHSIM to the field of transcription molding of polymers. POLYM. ENG. SCI. 46:1140,1146, 2006. © 2006 Society of Plastics Engineers. [source] Oral implants , the futureAUSTRALIAN DENTAL JOURNAL, Issue 2008A Jokstad Abstract The current and future application of implants to support intra- and extra-oral prostheses is a function not primarily of a current or eventual future, e.g., implant surface configuration, treatment procedure or loading protocol. In contrast, it must be understood by a more complex conceptualization of the practical application of the osseointegration phenomenon. This review will attempt to address the future use of oral implants based on current cutting edge research within the fundamentals that constitute the practical applications of the osseointegration concept. [source] Preparation and Characterization of Codeposited Palladium-Nickel/Titanium Electrodes and Palladium-Nickel/Polymeric Pyrrole Film/Titanium ElectrodesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 10 2008X. Hu Abstract Palladium-nickel/titanium (Pd-Ni/Ti) and palladium-nickel/polymeric pyrrole film/titanium (Pd-Ni/PPy/Ti) electrodes were prepared by electrochemical deposition. The electrochemical characteristics of the Pd-Ni/Ti and Pd-Ni/PPy/Ti electrodes were studied by means of cyclic voltammetry (CV) based on orthogonal experiments. CV studies on the electrodes were conducted in 0.5,mol/L sulfuric acid solution. Experimental results indicate that the hydrogen adsorption peak value of the Pd-Ni/PPy/Ti electrode seen at ca. ,500,mV is larger than that of Pd-Ni/Ti electrode. Scanning electron microscope (SEM) images indicate that polymeric pyrrole film, which formed on electrode can modify the electrode surface configuration significantly and provide the surface of the Pd-Ni/PPy/Ti electrode with more layers and a larger surface area. [source] The effect of inlet subcooling on two-phase flow instabilities in a horizontal pipe system with augmented surfacesINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 2 2002lmaz Abstract This research has been conducted to investigate the effect of inlet subcooling on two-phase flow instabilities in a horizontal pipe system with augmented surfaces. Five different inlet temperatures are used to study the effect of inlet subcooling for five different heat transfer surface configurations. All experiments are carried out at constant heat input, system pressure and exit restriction. The effect of inlet subcooling on the steady-state characteristics and two-phase flow instabilities are studied for each configuration. The bound aries for the appearance of pressure-drop-type and density-wave-type instabilities are found and the effect of the inlet subcooling on these oscillations is studied for each configuration. Copyright © 2002 John Wiley & Sons, Ltd. [source] A 3D HIGH RESOLUTION MODEL OF BOUNDING SURFACES IN AEOLIAN-FLUVIAL DEPOSITS: AN OUTCROP ANALOGUE STUDY FROM THE PERMIAN ROTLIEGEND, NORTHERN GERMANYJOURNAL OF PETROLEUM GEOLOGY, Issue 3 2007C. Fischer The fluvial-aeolian Rotliegend succession exposed in a quarry near Magdeburg (Flechtinger Höhenzug, Northern Germany) is an analogue for deeply-buried gas-bearing Rotliegend sandstones in the Southern Permian Basin. The spatial configuration of bounding surfaces within this succession was reconstructed with reference to twelve profiles with 926 sample points. Generally sub-horizontal interdune migration surfaces were surveyed, and the areal extent of small-scale superimposition surfaces and the thicknesses of intervening strata were measured. Based on these observations and also on the extent of different lithofacies types and on corresponding porosity and permeability data, a 3D lithofacies model (including bounding surface configurations) incorporating porosity and radial permeability was created using PETRELTÔ software. In the quarry, aeolian sandstones approximately 12 m thick (,, 5-11 vol. %, ,radial, 0.01-10mD) are separated into a number of tabular bed sets by sub-horizontal interdune migration surfaces. The surfaces are often associated with thin pelitic intervals with low permeabilities which originate from deflation and sheet flow events. Aeolian deposits consist mainly of two lithotypes: low-angle cross-bedded, and steeply cross-bedded medium-grained sandstones. Superimposition surfaces occur at the base of the low-angle cross-bedded sandstone bodies. The highest porosities and permeabilities occur within the steeply cross-bedded sandstones, reflecting intense eodiagenetic calcite and quartz cementation with subsequent calcite dissolution. The low-angle cross-bedded sandstones may act as flow baffles. This outcrop-derived, high resolution model may contribute to a better understanding of the subsurface architecture and reservoir properties of aeolian-fluvial successions. Taking into consideration the centimetre- to metre-scaled inhomogeneities observed at outcrop, lithotype modelling with reference to the occurrence of bounding surfaces may help to predict how similar reservoir rocks are partitioned. [source] Morphology of Symmetric Diblock Copolymers Confined Between Two Stripe-Patterned Surfaces , Tilted Lamellae and MoreMACROMOLECULAR THEORY AND SIMULATIONS, Issue 2 2005Qiang Wang Abstract Summary: We report the first Monte Carlo simulations on the thin-film morphology of symmetric diblock copolymers confined between either symmetrically or antisymmetrically stripe-patterned surfaces. Under suitable surface configurations (where the lamellae can comply with the surface patterns and can have a period close to the bulk lamellar period L0), tilted lamellae are observed for film thicknesses D,,,2L0; the checkerboard morphology is obtained for smaller film thicknesses. The A-B interfaces in the tilted lamellae are basically perpendicular to the surfaces in their immediate vicinity, and exhibit undulations away from them. In some cases, the severe frustration imposed by the two patterned surfaces leads to irregular or unexpected morphologies, which represent locally stable states. The efficient sampling of our expanded grand-canonical Monte Carlo technique enables us to observe more than one locally stable morphologies and the flipping between them during a single simulation run. Tilted lamellae between symmetrically patterned surfaces (perpendicular to z) with a surface pattern period of 1.5L0 and a film thickness of 2.67L0. L0 is the bulk lamellar period and the black curves mark the A-B interfaces. [source] Development of the Tarsometatarsal Skeleton by the Lateral Fusion of Three Cylindrical Periosteal Bones in the Chick Embryo (Gallus gallus)THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 9 2010Yuichi Namba Abstract An avian tarsometatarsal (TMT) skeleton spanning from the base of toes to the intertarsal joint is a compound bone developed by elongation and lateral fusion of three cylindrical periosteal bones. Ontogenetic development of the TMT skeleton is likely to recapitulate the changes occurred during evolution but so far has received less attention. In this study, its development has been examined morphologically and histologically in the chick, Gallus gallus. Three metatarsal cartilage rods radiating distally earlier in development became aligned parallel to each other by embryonic day 8 (ED8). Calcification initiated at ED8 in the midshaft of cartilage propagated cylindrically along its surface. Coordinated radial growth by fabricating bony struts and trabeculae resulted in the formation of three independent bone cylinders, which further became closely apposed with each other by ED13 when the periosteum began to fuse in a back-to-back orientation. Bone microstructure, especially orientation of intertrabecular channels in which blood vasculature resides, appeared related to the observed rapid longitudinal growth. Differential radial growth was considered to delineate eventual surface configurations of a compound TMT bone, but its morphogenesis preceded the fusion of bone cylinders. Bony trabeculae connecting adjacent cylinders emerged first at ED17 in the dorsal and ventral quarters of intervening tissue at the mid-diaphyseal level. Posthatch TMT skeleton had a seemingly uniform mid-diaphysis, although the septa persisted between original marrow cavities. These findings provide morphological and histological bases for further cellular and molecular studies on this developmental process. Anat Rec 293:1527,1535, 2010. © 2010 Wiley-Liss, Inc. [source] Effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the viability, proliferation and differentiation of osteoblast-like cells cultured on a chemically modified titanium surfaceCLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2009Adriane Y. Togashi Abstract Aim: The aim of the present study was to assess the influence of the chemical characteristics and roughness of titanium surfaces on the viability, proliferation and differentiation of osteoblast-like cells cultured in a medium supplemented with recombinant human bone morphogenetic protein-7 (rhBMP-7). Material and methods: Osteo-1 cells were grown on titanium disks presenting with the following surfaces: (1) machined, (2) coarse grit-blasted and acid-attacked (SLA) and (3) chemically modified SLA (SLAmod) in the absence or presence of 20 ng/ml rhBMP-7 in culture medium. The viability and number of osteo-1 cells were evaluated after 24 h. Analyses of total protein content (TP) and alkaline phosphatase (AP) activity at 7, 14 and 21 days, collagen content at 7 and 21 days and mineralized matrix formation at 21 days were performed. Results: Cell viability (P=0.5516), cell number (P=0.3485), collagen content (P=0.1165) and mineralized matrix formation (P=0.5319) were not affected by the different surface configurations or by the addition of rhBMP-7 to the medium. Osteo-1 cells cultured on SLA surfaces showed a significant increase in TP at 21 days. The ALPase/TP ratio (P=0.00001) was affected by treatment and time. Conclusion: The results suggest that the addition of rhBMP-7 to the culture medium did not exert any effect on the viability, proliferation or differentiation of osteoblast-like cells grown on the different surfaces tested. All titanium surfaces analyzed allowed the complete expression of the osteoblast phenotype such as matrix mineralization by osteo-1 cells. [source] Effect of platelet-rich plasma on the early bone formation around Ca-P-coated and non-coated oral implants in cortical boneCLINICAL ORAL IMPLANTS RESEARCH, Issue 2 2008Dimitris Nikolidakis Abstract Objectives: The purpose of the present study was to investigate the effect of local application of platelet-rich plasma (PRP) on the early healing of cortical bone around Ti implants with two different surface configurations. Material and methods: Six goats were used in this study. PRP fractions were obtained from a venous blood sample of the goats and administered immediately before implant insertion. PRP was applied via gel preparation and installation of the gel into the implant site, or via dipping of the implants in PRP fraction before insertion. A total of 36 implants (18 non-coated and 18 Ca-P-coated) were placed into the tibial cortical bone. The animals were sacrificed at 6 weeks after implantation and implants with surrounding tissue were prepared for histological examination. Histomorphometrical variables like the percentage of implant surface with direct bone,implant contact and the percentage of new and old bone adjacent to the implant were evaluated. Results: More interfacial bone-to-implant contact was observed for all the three groups of Ca-P-coated implants and the Ti/PRP liquid group. All groups revealed similar percentages of old and new bone adjacent to the implant. Conclusions: It was concluded that the additional use of PRP did not have any effect on the early cortical bone response to the Ca-P-coated implants, while PRP in a liquid form showed a tendency to increase bone apposition to roughened titanium implants. [source] | |||||||||||||