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Liner
Kinds of Liner Selected AbstractsThe nature of the Sloan Digital Sky Survey galaxies in various classes based on morphology, colour and spectral features , III.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2010Environments ABSTRACT We present a study on the environments of the Sloan Digital Sky Survey (SDSS) galaxies divided into fine classes based on their morphology, colour and spectral features. The SDSS galaxies are classified into early-type and late-type; red and blue; passive, H ii, Seyfert and low-ionization nuclear emission-line region (LINER), which returns a total of 16 fine classes of galaxies. We estimate the local number density, target-excluded local luminosity density, local colour, close pair fraction and the luminosity and colour of the brightest neighbour, which are compared between the fine classes comprehensively. The morphology,colour class of galaxies strongly depends on the local density, with the approximate order of high-density preference: red early-type galaxies (REGs); red late-type galaxies (RLGs); blue early-type galaxies (BEGs) and blue late-type galaxies (BLGs). We find that high-density environments (like cluster environments) seem to suppress active galactic nucleus activity. The pair fraction of H ii REGs does not show a statistically significant difference from that of passive REGs, while the pair fraction of H ii BLGs is smaller than that of non-H ii BLGs. H ii BLGs show obvious double (red + blue) peaks in the distribution of the brightest neighbour colour, while red galaxies show a single red peak. The brightest neighbours of Seyfert BLGs tend to be blue, while those of LINER BLGs tend to be red, which implies that the difference between Seyfert and LINER may be related to the pair interaction. Other various environments of the fine classes are investigated, and their implications for galaxy evolution are discussed. [source] The disc-dominated host galaxy of FR-I radio source B2 0722+30MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2009B. H. C. Emonts ABSTRACT We present new observational results that conclude that the nearby radio galaxy B2 0722+30 is one of the very few known disc galaxies in the low-redshift Universe that host a classical double-lobed radio source. In this paper, we use H i observations, deep optical imaging, stellar population synthesis modelling and emission-line diagnostics to study the host galaxy, classify the active galactic nucleus (AGN) and investigate environmental properties under which a radio-loud AGN can occur in this system. Typical for spiral galaxies, B2 0722+30 has a regularly rotating gaseous disc throughout which star formation occurs. Dust heating by the ongoing star formation is likely responsible for the high infrared luminosity of the system. The optical emission-line properties of the central region identify a Low Ionization Nuclear Emission-line Region (LINER)-type nucleus with a relatively low [O iii] luminosity, in particular when compared with the total power of the Fanaroff & Riley type-I radio source that is present in this system. This classifies B2 0722+30 as a classical radio galaxy rather than a typical Seyfert galaxy. The environment of B2 0722+30 is extremely H i -rich, with several nearby interacting galaxies. We argue that a gas-rich interaction involving B2 0722+30 is a likely cause for the triggering of the radio AGN and/or the fact that the radio source managed to escape the optical boundaries of the host galaxy. [source] Why are AGN found in high-mass galaxies?MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2008Lan Wang ABSTRACT There is a strong observed mass dependence of the fraction of nearby galaxies that contain either low-luminosity [low-ionization nuclear emission-line region (LINER) type] or higher luminosity (Seyfert or composite type) active galactic nuclei (AGN). This implies that either only a small fraction of low-mass galaxies contain black holes, or that the black holes in these systems only accrete rarely or at very low rates, and hence are generally not detectable as AGN. In this paper, we use semi-analytic models implemented in the Millennium Simulation to analyse the mass dependence of the merging histories of dark matter haloes and of the galaxies that reside in them. Only a few per cent of galaxies with stellar masses less than M* < 1010 M, are predicted to have experienced a major merger. The fraction of galaxies that have experienced major mergers increases steeply at larger stellar masses. We argue that if a major merger is required to form the initial seed black hole, the mass dependence of AGN activity in local galaxies can be understood quite naturally. We then investigate when the major mergers that first create these black holes are predicted to occur. High-mass galaxies are predicted to have formed their first black holes at very early epochs. The majority of low-mass galaxies never experience a major merger and hence may not contain a black hole, but a significant fraction of the supermassive black holes that do exist in low-mass galaxies are predicted to have formed recently. [source] Multiwavelength study of the nuclei of a volume-limited sample of galaxies , I. X-ray observationsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2000P. Lira We discuss ROSAT HRI X-ray observations of 33 very nearby galaxies, sensitive to X-ray sources down to a luminosity of approximately 1038 erg s,1. The galaxies are selected from a complete, volume-limited sample of 46 galaxies with for which we have extensive multiwavelength data. For an almost complete subsample with (29/31 objects) we have HRI images. Contour maps and source lists are presented within the central region of each galaxy, together with nuclear upper limits where no nuclear source was detected. Nuclear X-ray sources are found to be very common, occurring in ,35 per cent of the sample. Nuclear X-ray luminosity is statistically connected to host galaxy luminosity , there is not a tight correlation, but the probability of a nuclear source being detected increases strongly with galaxy luminosity, and the distribution of nuclear luminosities seems to show an upper envelope that is roughly proportional to galaxy luminosity. While these sources do seem to be a genuinely nuclear phenomenon rather than nuclear examples of the general X-ray source population, it is far from obvious that they are miniature Seyfert nuclei. The more luminous nuclei are very often spatially extended, and H ii region nuclei are detected just as often as LINERs. Finally, we also note the presence of fairly common superluminous X-ray sources in the off-nuclear population , out of 29 galaxies we find nine sources with a luminosity greater than 1039 erg s,1. These show no particular preference for more luminous galaxies. One is already known to be a multiple SNR system, but most have no obvious optical counterpart and their nature remains a mystery. [source] Randomized comparison of the SLIPA (Streamlined Liner of the Pharynx Airway) and the SS-LM (Soft Seal Laryngeal Mask) by medical studentsEMERGENCY MEDICINE AUSTRALASIA, Issue 5-6 2006Cindy Hein Abstract Objective:, The aim of the study was to compare the Streamlined Liner of the Pharynx Airway (SLIPA; Hudson RCI), a new supraglottic airway device, with the Soft Seal Laryngeal Mask (SS-LM; Portex) when used by novices. Methods:, Thirty-six medical students with no previous airway experience, received manikin training in the use of the SLIPA and the SS-LM. Once proficient, the students inserted each device in randomized sequence, in two separate patients in the operating theatre. Only two insertion attempts per patient were allowed. Students were assessed in terms of: device preference; success or failure; success at first attempt and time to ventilation. Results:, Sixty-seven per cent of the students preferred to use the SLIPA (95% confidence interval 49,81%). The SLIPA was successfully inserted (one or two attempts) in 94% of patients (34/36) and the SS-LM in 89% (32/36) (P = 0.39). First attempt success rates were 83% (30/36) and 67% (24/36) in the SLIPA and SS-LM, respectively (P = 0.10). Median time to ventilation was shorter with the SLIPA (40.6 s) than with the SS-LM (66.9 s) when it was the first device used (P = 0.004), but times were similar when inserting the second device (43.8 s vs 42.9 s) (P = 0.75). Conclusions:, In the present study novice users demonstrated high success rates with both devices. The SLIPA group achieved shorter times to ventilation when it was the first device they inserted, which might prove to be of clinical significance, particularly in resuscitation attempts. Although the Laryngeal Mask has gained wide recognition for use by both novice users and as a rescue airway in failed intubation, the data presented here suggest that the SLIPA might also prove useful in these areas. [source] Adhesive bonding of titanium,aluminum,niobium alloy with nine surface preparations and three self-curing resinsEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2003Hiroaki Yanagida The purpose of the current study was to evaluate the adhesive performance of metal conditioners when used for bonding between auto-polymerizing methacrylic resins and a titanium alloy. Disk specimens were cast from a titanium,aluminum,niobium (Ti,6Al,7Nb) alloy, air-abraded with alumina, and bonded with 24 combinations of eight metal conditioners (Acryl Bond, ACB; All-Bond 2 Primer B, ABB; Alloy Primer, ALP; Cesead II Opaque Primer, COP; Metafast Bonding Liner, MBL; Metal Primer II, MPII; MR Bond, MRB; Super-Bond liquid, SBL) and three autopolymerizing methacrylic resins (Repairsin, RE; Super-Bond C & B, SB; Tokuso Rebase; TR). Unprimed specimens were used as controls. Shear bond strengths were determined both before and after thermocycling (4,60°C, 20, 000 cycles). The ALP-SB group recorded the greatest post-thermocycling bond strength (21.8 MPa) followed by the COP-SB group (17.8 MPa) and the MPII-SB group. The post-thermocycling bond strengths of the unprimed-SB group and the ALP-RE group were statistically comparable. No significant differences were found among the nine TR resin groups, and these groups showed the lowest bond strength. In conclusion, the use of one of the three conditioners (ALP, COP, and MPII) in combination with the SB resin is recommended for bonding the Ti,6Al,7Nb alloy. [source] Adhesive bonding of composite material to cast titanium with varying surface preparationsJOURNAL OF ORAL REHABILITATION, Issue 2 2002H. Yanagida The purpose of the present study was to evaluate the surface preparation effects of eight metal conditioners and an adhesive system on bonding between a prosthodontic composite material and cast titanium. Eight primers designed for conditioning base metal alloys (Acryl Bond, All-Bond 2 Primer B, Alloy Primer, Cesead II Opaque Primer, Eye Sight Opaque Primer, Metafast Bonding Liner, Metal Primer II, and MR Bond) as well as a surface modification technique (Siloc) were assessed. Disk specimens cast from titanium (T-Alloy H) were either primed with one of the eight primers or treated with the Siloc system, and then bonded with a light-activated composite material (Artglass). Bond durability was evaluated by thermocycling (4 and 60 °C, 1 min each, 20 000 cycles). After thermocycling, two groups either primed with the Cesead II Opaque Primer material or treated with the Siloc system exhibited significantly greater bond strength (20·0 and 19·0 MPa) than the other groups (0·2,12·6 MPa, P < 0·05). These two systems are considered to be useful for improving bonding between the titanium and the composite material tested. [source] A Picture of the Floating World: Grounding the Secessionary Affluence of the Residential Cruise LinerANTIPODE, Issue 1 2009Rowland Atkinson Abstract:, A quarter century of financial deregulation, robber-baron corporatism and growing income polarisation has enabled the spatial partitioning of urban space into new and complex arrangements of micro-neighbourhood governance and privatism. These archipelagos of fortress homes and neighbourhoods increasingly lie outside the spaces of conventional state and city government. Yet while residential spaces of urban affluence have been unable to fully remove contact with the social diversity of the public realm, nomadic forms of super-affluence, flowing around a global,national urban system, have generated a form of networked extra-territoriality,a social space decoupled from the perceived risks and general dowdiness of the social world beneath it. This paper examines this space via the curious case of The World, a large residential cruise ship which, as its name suggests, roams the oceans and ports of the globe. Our title is taken from the name given to Japanese paintings of the new affluence and fantasy of life lived by the affluent and artists in late nineteenth century Japanese cities (O Ukiyo E, or pictures of the floating world). We suggest that The World forms a similarly disconnected realm, not only literally afloat, also detached from the reality of a world that has been strategically left behind. [source] Skin Abscess Model for Incision and DrainageACADEMIC EMERGENCY MEDICINE, Issue 2009Myto Duong Background: Skin and soft tissue infection diagnosis is increasing dramatically across the nation. All healthcare providers need to be trained in adequate incision and drainage of these lesions. The only descriptions of skin and soft tissue models in the literature involve the use of cadavers or chickens. We devised an inexpensive and easily assembled skin abscess model that will be invaluable for the training of this procedure for all healthcare providers. This relatively realistic skin abscess model can be assembled within minutes using materials that can be purchased in your local grocery or home improvement store. The steps required in the creation of this abscess model will be depicted in the exhibit. Supplies for assembly of the model will be available during the exhibition for participants to build their own abscess and practice incising and draining their abscess. Materials: ? Lotion (white) mixed with food coloring (red, blue, yellow) ? Baby oil gel ? 1" Urethane Foam sheeting ? Heavy cardboard or poster board ? Food handler gloves (Textra Cast Poly) ? Glue gun (low temp) ? Low temp glue gun sticks ?"Smooth Top® Easy Liner®" shelf liner ? Abscess incision and drainage kit. Conclusion: This exhibit will provide a detailed description of how to assemble a quick and easy skin abscess model for incision and drainage. This model can be used in the skills lab to demonstrate and practice this basic procedure. [source] Polyethylene cross-linking by two different methods reduces acetabular liner wear in a hip joint wear simulatorJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2003Darryl D. D'Lima Advances in cross-linking have led to the development of wear resistant ultrahigh molecular weight polyethylene for total joint replacement. This study compared wear reduction by two different cross-linking methods as measured in a hip wear simulator. One highly cross-linked polyethylene was treated with 7.5 Mrad gamma irradiation with post-irradiation annealing and a sterilization dose of 2.5 Mrad (10 Gamma), while the other used 9.5 Mrad warm irradiation with 10 MeV electron-beam (9.5 EB). Liners of the same design, made from nominally cross-linked (gamma sterilized) polyethylene were also tested. Gravimetric wear analysis was performed every 500,000 cycles for 5,000,000 cycles. After correcting for weight gain due to water absorption, the nominally cross-linked liners demonstrated mean wear rates of 15.7 (±1.7) and 12.5 (±1.0) mg/million cycles. Both highly cross-linked polyethylene liners demonstrated significantly less wear than their respective controls (with mean wear rates of 1.5 (±1.2) and ,1.4 (±1.5) mg/million cycles). The 9.5 EB liners gained weight presumably due to increased fluid absorption, in addition to that measured in loaded,soaked control implants. Any wear occurring was therefore assumed to have been more than offset by weight gain. Highly cross-linked polyethylene was significantly more wear resistant than non- or nominally cross-linked polyethylene. The differences in wear rates between the two highly cross-linked polyethylene designs (9.5 EB or 10 Gamma) are probably too small to be clinically significant. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Modified Class II open sandwich restorations: evaluation of interfacial adaptation and influence of different restorative techniquesEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2002Ingrid E. Andersson-Wenckert The sandwich technique with resin-modified glass ionomer cement (RMGIC) has been proposed to relieve the contraction stresses of direct resin composite (RC) restorations. The aim of this study was to evaluate the interfacial adaptation to enamel and dentin of modified Class II open RMGIC/RC sandwich restorations and the influence of different light curing techniques and matrix bands. Forty box-shaped Class II fillings were placed in vivo in premolars scheduled for extraction after one month. In groups I and II, a metal matrix was used; RC was inserted with horizontal (group I) and diagonal (group II) increments and cured with indirect/direct light. Group III was performed as group II, but a transparent matrix was used. Group IV was as group II, but with a separating liner between RMGIC and RC. Group V was a closed sandwich restoration. Interfacial quality was studied using SEM replica technique. Gap-free interfacial adaptation to enamel was observed for RMGIC in 70%, for RC in 70% and to dentin for RMGIC in 81%, for RC in 56%. No significant differences were seen between the experimental groups. At the cervical margins, RMGIC showed significantly better adaptation to enamel than RC, 74% and 42%, respectively. In conclusion, the investigated restorations showed a high percentage of gap-free interfacial adaptation in vivo. Interfacial adaptation to dentin and to cervical enamel was significantly better for RMGIC than for RC. [source] Industrial experiences of bending fatigue strength in table liner for cement millFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 6 2010S.-H. BAEK ABSTRACT A table liner for the vertical roller mill has been used to grind natural limestone. Unexpected fatigue failure accidents have occurred during portland cement manufacturing process. The design life of a table liner is 4 × 107 cycles, but the actual fatigue life of a table liner is 2 × 106 to 8 × 106 cycles. The fatigue crack of a table liner initiates from the outside edge of the grinding path of the limestone. When such a crack occurs, the table liner has to be replaced, and this requires 30% of the total maintenance cost of the vertical roller mill. Therefore, this study examines the fatigue failure of a table liner by plane-bending fatigue test, stress measurement test, finite element analysis and fatigue fracture analysis. [source] A New Depth-Discrete Multilevel Monitoring Approach for Fractured RockGROUND WATER MONITORING & REMEDIATION, Issue 2 2007John A. Cherry A new approach for monitoring in fractured rock was demonstrated in a contaminated (trichloroethylene and metolachlor) dolostone aquifer used for municipal water supply. The system consists of two related technologies: a continuous packer for temporary borehole seals (Flexible Liner Underground Technologies Ltd. [FLUTe] blank liner) and a depth-discrete multilevel monitoring system (MLS) (the Water FLUTe) for temporary or permanent monitoring. The continuous borehole liner consists of a urethane-coated nylon fabric tube custom sized to each hole. The FLUTe MLS consists of the same liner material with many depth-discrete intervals for monitoring hydraulic head and/or ground water quality. The FLUTe blank liner seals the entire borehole, prior to FLUTe multilevel installation, to prevent vertical cross connection while allowing borehole logging and testing. The FLUTe multilevel system also seals the entire borehole with the exception of each monitoring interval where the formation water has direct hydraulic connection to the pumping system via a thin permeable mesh sandwiched between the liner and the formation. The blank sealing liners and the multilevel systems were used in five boreholes ranging in diameter between 9.6 and 14.5 cm in the dolostone aquifer to depths of 150 m. The systems were custom designed for each borehole and included between 12 and 15 monitoring intervals. The application demonstrated the ease of installation and removability and facilitated obtaining large data sets with minimal labor. The system offers unique and versatile design features not possible with other bedrock monitoring devices and has been used at many bedrock contamination sites across North America. [source] Solute transport through a deforming porous mediumINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 7 2002Glen P. Peters Abstract Solute transport through a porous medium is typically modelled assuming the porous medium is rigid. However, many applications exist where the porous medium is deforming, including, municipal landfill liners, mine tailings dams, and land subsidence. In this paper, mass balance laws are used to derive the flow and transport equations for a deforming porous medium. The equations are derived in both spatial and material co-ordinate systems. Solute transport through an engineered landfill liner is used as an illustrative example to show the differences between the theory for a rigid porous medium, and small and large deformation analysis of a deforming porous medium. It is found that the large deformation model produces shorter solute breakthrough times, followed by the small deformation model, and then the rigid porous medium model. It is also found that it is important to include spatial and temporal void ratio variations in the large deformation analysis. It is shown that a non-linear large deformation model may greatly reduce the solute breakthrough time, compared to a standard transport analysis typically employed by environmental engineers. Copyright © 2002 John Wiley & Sons, Ltd. [source] Three-dimensional finite element analysis of lined tunnelsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 3 2001C. E. Augarde Abstract This paper describes finite element procedures that have been developed to model the ground movements that occur when a shallow tunnel is installed in a clay soil. This study is part of a wider project concerned with the development of new methods to predict the likely extent of damage to surface structures caused by nearby shallow tunnelling. This particular paper, however, is concerned only with the numerical model of tunnel installation. The structural liner is an important component of this tunnel installation model; two different ways of modelling the liner (based on continuum elements and shell elements) are discussed in the paper. A test problem consisting of the installation of a lined tunnel in an elastic continuum is used to investigate the merits of these different approaches. When continuum elements are used to model the liner, the numerical results agree well with an analytical solution to the problem. When shell elements are used to model the liner, however, the results were found to be significantly influenced by the particular formulation adopted for the shell elements. Example analyses, involving incremental tunnel construction in a clay soil where the soil is modelled using a kinematic hardening plasticity model, are described. These analyses confirm that a thin layer of continuum elements may be used, satisfactorily, to model tunnel linings in a soil,structure interaction analysis of this sort. Copyright © 2001 John Wiley & Sons, Ltd. [source] Thermal decomposition of tert -butyl peroxide in a gas chromatographic reactor: A comparison of kinetic approachesINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 7 2004Peter J. Skrdla The thermal decomposition of tert -butyl peroxide is investigated utilizing both the column and the injection port of a commercial gas chromatograph (GC) as chemical reactors. Using the injector liner as the reactor, the chromatographic peak areas of the reactant, measured at various injector temperatures, are used in the determination of the activation energy of the decomposition (Ea). With the column serving as the reactor, both the reactant peak areas and the product peak shapes are similarly utilized for this purpose. Values of Ea obtained using different mathematical treatments for each of the three approaches are found to range from 115 to 164 kJ/mol. Of these methods, the column reactor approach utilizing peak area measurements (referred to as PACR, for "peak area, column reactor") is found to be far superior in terms of its speed, robustness, and its accuracy in determining Ea. The PACR method's effectiveness can be largely attributed to the mathematical treatment that is described in the approach. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 386,393, 2004 [source] QUALITY OF MODIFIED ATMOSPHERE PACKAGED "BARTLETT" PEARS AS INFLUENCED BY TIME AND TYPE OF STORAGEJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2004S.R. DRAKE ABSTRACT Commercially mature "Bartlett" pears for this study were obtained from local commercial packing facilities. In the first year, pears were packed in modified atmosphere bags and placed in boxes or packed normally (control) with an individual paper wrap around each pear plus a polyethylene liner in the box. Boxed pears from both types of packaging were stored in regular atmosphere (RA) storage at 1C for 30 or 90 days. In the second year, pears were packed normally and stored in both RA or controlled atmosphere (CA) storage for 45 or 90 days, or packed in modified atmosphere bags and stored in RA at 1C. After 45 days, normally packed pears from both RA and CA were removed from their initial storage, placed in modified atmosphere bags and returned to RA storage for an additional 45 days. Pears stored in modified atmosphere bags were superior in quality to normally packed pears stored only in RA storage and equal in quality to pears stored in CA for periods of 90 days. The quality of pears held in modified atmosphere bags under CA conditions deteriorated after only short periods of time (<45 days). Pears in modified atmosphere bags should be stored only in RA. Little or no quality advantage was evident if use of modified atmosphere bags was delayed regardless of prior storage type. [source] Effect of an antifungal denture liner on the saliva yeast count in patients with denture stomatitis: a pilot studyJOURNAL OF ORAL REHABILITATION, Issue 9 2008G. A. V. M. GEERTS Summary, Although in vitro studies on the release of antifungal agents from tissue conditioners have been done, no in vivo research on the topic could be found. The purpose of this study was to determine the in vivo effect of an antifungal agent released from a tissue conditioner on the salivary yeast count. Forty edentulous patients with denture stomatitis caused by Candida albicans were divided in two groups. Group 1 (control) was treated with a tissue conditioner only. Group 2 was treated with a tissue conditioner incorporating 500 000 U nystatin. Oral rinses were performed by both groups before treatment and every second day during treatment for a period of 14 days. Total yeast counts of the oral rinses were performed and the averages and standard deviations for both groups calculated and logarithm-transformed data of the counts over time were statistically analysed using the Wilcoxon signed-rank test. The average oral rinse yeast count of the control group decreased up to day 4. Thereafter, the count increased till the end of the test period. At day 14, the oral rinse yeast level was higher than the pre-treatment level. The average yeast count of the test group decreased up to day 7. Thereafter, the count increased but remained significantly lower (P = 0·01) than the control group and did not return to its pre-treatment level. A nystatin-containing short-term denture liner significantly decreases the salivary yeast count of patients with denture stomatitis compared with a liner without nystatin. [source] Changes in surface roughness and colour stability of soft denture lining materials caused by denture cleansersJOURNAL OF ORAL REHABILITATION, Issue 2 2003C. Jin summary, Soft denture lining materials were immersed into solutions of denture cleansers for 8 h at room temperature, and immersed into distilled water for the remainder of the 24-h period at 37 °C. Surface roughness of the soft denture lining materials was measured by contact type surface roughness instrument. For the colour stability test, soft denture lining materials were immersed in the denture cleansers as described above for 180 days. Finally, the colour changes of each material were quantitatively measured by a photometrical instrument to obtain the colour differences between newly processed specimen and immersed specimens (P < 0·01). An autopolymerizing silicone material, Evatouch, exhibited severe changes in surface roughness by all denture cleanser, and the generic material GC Denture Relining showed the minimal changes. Severe colour changes were also observed with some liner and cleanser combinations (P < 0·01). Except for Evatouth, the four silicone soft liners were more stable in surface roughness and in colour change than the two acrylic soft liners. One autopolymerizing silicone (GC denture relining) and one heat curing silicone (Molloplast B) demonstrated the best stability. [source] Effect of viscoelastic properties of resilient denture liners on pressures under denturesJOURNAL OF ORAL REHABILITATION, Issue 11 2001N. Taguchi In order to evaluate the influence of viscoelastic properties of resilient denture liners on the pressures under dentures, a series of creep and stress relaxation tests were carried out using a simplified mandibular edentulous model and denture model. Two diaphragm pressure sensors were attached to the edentulous model so that they contacted the residual ridge and the buccal slope. The results may be summarized as follows: (i) The use of resilient denture liners is effective for stress relief under dentures. (ii) The thickness increase of each denture liners causes the effect of stress relaxation. (iii) The material exhibited viscoelastic behaviour after applying the stress and has the ability to distribute stress or stress relaxation. It is important to understand the viscoelastic behaviours of each resilient denture liner and choose the material according to the clinical situation. The information obtained should be useful to clinicians when they select materials for their patients. [source] Effect of cavity varnish, amalgam liner or dentin bonding agents on the marginal leakage of amalgam restorationsJOURNAL OF ORAL REHABILITATION, Issue 5 2001S. Belli The purpose of this in vitro study was to compare marginal leakage of Class II amalgam restorations lined with different agents (two new generation dentin bonding systems, a cavity varnish and an amalgam liner). Forty freshly extracted human molar teeth were divided into five groups. Class II preparations were prepared in the mesial and distal surfaces of each molar. While the cavities in two groups were lined with two new generation bonding systems, the other two groups were treated with an amalgam lining material and a cavity varnish. Fifth group was used as control, without any lining. Amalgam* was hand-condensed into each preparation. Specimens were thermocycled, stained and sectioned. Microleakage was graded using a stereomicroscope. Mean microleakage scores for occlusal and cervical margins were calculated and analised. For the leakage values on occlusal margins, Kruskal,Wallis test indicated no significant difference in all groups. For the leakage values on cervical margins, Kruskal,Wallis test indicated significant difference in four groups when compared with controls (P < 0·001). On the other hand, there was no significant difference between the occlusal and cervical leakage values in each group. [source] Finite element analysis of stress relaxation in soft denture linerJOURNAL OF ORAL REHABILITATION, Issue 8 2000Y. Sato To gather knowledge related to establishing criteria for selecting soft denture liners for individual patients, the effects of certain properties of soft denture liners on stress distribution were evaluated by two-dimensional finite element analysis. A partial mandibular edentulous ridge crest was modelled. Six combinations of thickness (mucosa: 1 or 2 mm; soft denture liner: 1, 2, or 3 mm) and 18 combinations of Young's modulus (mucosa: three kinds; soft denture liner: six kinds) were analysed. The ratio of maximum to minimum stress in the mucosa (stress ratio) was calculated to estimate stress concentration. In the case of thin mucosa (1 mm thickness), the lower the Young's modulus of the soft denture liner, the lower the stress ratio. However, if the soft denture liner had a lower Young's modulus than the mucosa, stress concentrated adversely. These results suggest that the elasticity of the soft denture liner should match the elasticity of the mucosa to obtain the optimum cushioning effect. [source] Release liner removal method for transdermal drug delivery systems (TDDS)JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2010Anna M. Wokovich Abstract A release liner removal test is a valuable test for assessing the quality of a transdermal drug delivery system (i.e., TDDS, patch). This test measures the force required to remove the release liner from a patch. The objective of the present study was to establish sample preparation and instrument parameters for measuring release liner removal adhesion for TDDS. Ten TDDS were evaluated (six drugs for a total of 29 lots). Patches which had a rate-controlling membrane were run as-is, since they could not be cut to a precise width without sacrificing their structural integrity. Patches that were square or rectangular in shape were run as-is, and the width of these patches was determined using a digital caliper. Patches which were not square or rectangular in shape and did not have a rate-controlling membrane were cut to a precise width using a specimen cutter. Double-sided tape was used to adhere the liner side of the transdermal system to a clean stainless steel test panel. A release liner peel adhesion method for TDDS is proposed using a dwell time of approximately 3,min, a peel angle of 90°, and a peel speed of 300,mm/min. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:3177,3187, 2010 [source] Sumatriptan succinate transdermal delivery systems for the treatment of migraineJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2008C. Balaguer-Fernández Abstract We have successfully obtained sumatriptan transdermal systems with different polymer compositions: methyl cellulose (MC), polyvinyl pyrrolidone (PVP) and a polyvinyl pyrrolidone (PVP)-polyvinyl alcohol (PVA) mixture. The systems contained 1,2-propilenglycol (MC) or sorbitol as a plasticizer (PVP and PVP-PVA), methacrylate copolymer as an adhesive agent, and an occlusive liner. Azone® (5%, w/w) was incorporated into all the systems as a percutaneous enhancer. Transdermal systems are thin, transparent and non-adhesive when in a dry state. The permeation of sumatriptan succinate across pig ear skin was studied using the systems prepared. The formulation with MC polymer produced a statistically significant increment with respect to the PVP and PVP-PVA formulations (p,<,0.05). Azone® incorporation into the systems produced an increment in the sumatriptan flux values of all three transdermal systems with respect to those of the controls (p,<,0.05). In addition, the application of iontophoresis to the wet methyl cellulose-Azone® formulation produced a much higher increase of sumatriptan transdermal flux. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:2102,2109, 2008 [source] Effect of Aging on Coronal Microleakage in Access Cavities through Metal Ceramic Crowns Restored with Resin CompositesJOURNAL OF PROSTHODONTICS, Issue 5 2010Ali Abdullah Alwan Al-Maqtari BDS Abstract Purpose: The purpose of this in vitro study was to determine if packable resin composite with/without flowable resin composite has the ability to prevent coronal leakage in restored endodontic access openings following aging. Materials and Methods: Eighty simulated standardized access cavities of metal-ceramic crowns were fabricated and fixed on Vitrebond cavities filled with an epoxy resin. The specimens were randomly divided into two main groups: (1) Group A,Access cavities filled with only packable composite (Filtek P60); (2) Group B,Access cavities filled with Filtek P60 and a flowable composite (Filtek Z350) as liner. Each main group was further subdivided randomly into four subgroups according to water storage and thermocycling periods. All specimens were immersed in blue ink solution for 24 hours and then sectioned into quadrants. The extension of blue ink along the metal-ceramic crown/composite resin interface was measured linearly using image analyzer and then analyzed by three-way ANOVA and independent t -test with a Mann-Whitney test. The level of significance was set at p < 0.05. Results: All tested subgroups demonstrated different levels of microleakage. There was no significant difference related to restorative technique; however, there was a significant difference related to water storage and thermocycling. Conclusions: All tested techniques and materials in this study showed microleakage. Packable composite while a flowable liner showed a marginally better result than packable composite alone. Excessive thermocycling resulted in significant differences among the test groups. [source] Effect of Net Fiber Reinforcement Surface Treatment on Soft Denture Liner Retention and LongevityJOURNAL OF PROSTHODONTICS, Issue 4 2010MPhil, Muhanad M. Hatamleh BSc Abstract Purpose: To evaluate shear bond strength of Molloplast-B soft liner attached to different acrylic surfaces (smooth, rough, and Sticktech net fiber-reinforced interfaces) after 3000 thermal cycles. Materials and Methods: Sixty-nine specimens were fabricated by attaching Molloplast-B soft liner to acrylic bases of three interfaces (n= 23); smooth (Group 1, control), rough (Group 2), and Sticktech net fiber-reinforced interface (Group 3). The specimens underwent 3000 thermocycles (5 and 55°C) before being subject to a shear bond test at 2 mm/min crosshead speed. Debonding sites were investigated using an optical microscope at 40× magnification. Bond failures were categorized as adhesive, cohesive, or mixed. Results: Mean (SD) bond strength values (MPa) were: 0.71 (0.15); 0.63 (0.07); and 0.83 (0.12) for smooth, rough, and fiber-reinforced acrylic interfaces, respectively. The mean values were analyzed using one-way ANOVA and Bonferroni post hoc test for pairwise comparisons (p, 0.05). The net fiber-reinforced acrylic interface exhibited a statistically significantly higher bond strength value when compared to smooth and rough acrylic interfaces (P= 0.003 and P= 0.000, respectively). Modes of failure were mainly cohesive (91%), followed by mixed failures (9%). Conclusions: Molloplast-B exhibited a stronger bond to StickTech Net fiber-reinforced surfaces when compared to smooth and rough acrylic interfaces after thermocycling. This may enhance prosthesis serviceability during clinical use. [source] Candida albicans colonization of surface-sealed interim soft linersJOURNAL OF PROSTHODONTICS, Issue 4 2000Luciano Olan-Rodriguez DDS Purpose This in-vivo investigation evaluated the effect of 2 denture sealer agents on the microbial colonization of a newly placed soft interim denture liner during a period of 14 days. Materials and Methods An interim soft denture liner (Coe-Soft; GC America, Alsip, IL) was coated with 2 different denture surface sealants (Palaseal [Heraeus Kulzer, Irvine, CA] and Mono-Poly [Plastodent, New York, NY]). Three rectangular wells of 1 cm wide × 2 cm long × 2 mm deep were placed in the intaglio of 10 maxillary complete dentures and filled with the soft liner material. The soft liner surface was treated with Palaseal (first well) and Mono-Poly (second well), and the unsealed (third well) was used as a control. These were exposed to the oral cavity for 14 days. The effect the sealant had in the prevention of Candidal colonization in vivo of the soft liner material was evaluated. Microbiological specimens were recovered from all samples and cultivated. Microbiological data from the control and 2-test samples in each denture were tabulated, and statistical analyses were performed. Results This investigation showed clear differences (p < .001) between the sealed and unsealed soft liners. The sealed material showed significantly less colonization by yeast and bacteria. Intercomparison of the surface denture sealers, Palaseal versus Mono-Poly, showed no statistically significant differences (p < .005) in total yeast or bacterial colonization. Conclusion Coating of Coe-Soft denture liner with either Palaseal or Mono-Poly significantly decreased yeast and bacterial colonization. [source] Functional properties of microstructured cylinder liner surfaces for internal combustion enginesLUBRICATION SCIENCE, Issue 4 2005R. Golloch Abstract Internal combustion engines are still of major importance as propulsion systems. To fulfil future market and legislative demands it is necessary to improve engine performance, reduce fuel consumption, and limit exhaust emissions. Mechanical and thermodynamic losses, wear, and the emissions caused by lubricating oil combustion are principally influenced by the tribological behaviour of the piston assembly. The trend towards compact engines with high power densities and increased thermomechanical loads increases the importance of this tribological system and requires new approaches. One promising possibility is the utilisation of liner surfaces with specially machined microstructures. This paper describes a comparison between a conventional liner surface and a laser-structured liner as regards their tribological behaviour. Measurements of wear as well as of oil film thickness and friction force in operation have been carried out. The results show better tribological behaviour for the laser-structured liner surface than for the conventional plateau-honed surface. This leads to lower fuel consumption and less wear. [source] Characterisation of Diesel Engine Cylinder Liner Deposits by Surface MeasurementsLUBRICATION SCIENCE, Issue 3 2004Řyvind Buhaug Abstract This paper briefly reviews cylinder liner deposits and describes their effect on lubricating oil consumption and surface topography. Cylinder liner deposits may be invisible to the naked eye, but can be identified by surface topography measurement. A simulation of a cylinder liner with deposits is used to identify which of the available surface characteristics is best suited as a measure of deposit severity. Surface measurements are used to detect deposits in a case study. The deposits are found to be concentrated in a belt around the mid-stroke region of the cylinder liner. The comparatively low position of the deposit may explain the slow response of a fuel additive treatment in restoring oil consumption control, as the additive treatment in this case is seen to be most effective in the uppermost part of the cylinder liner. [source] Growth of Fe doped semi-insulating GaN on sapphire and 4H-SiC by MOCVDPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2006M. Rudzi Abstract We report a study of iron doped GaN layers grown on sapphire and SiC by Metal Organic Chemical Vapor Deposition (MOCVD) using ferrocene as the Fe precursor. The influence of iron doping on the electrical, structural and morphological properties of the GaN layers was studied. A resistivity of 6x103 ,cm and higher was achieved in contrast to 3 ,cm for the undoped film. Defect selective etching showed that Fe doping increases the threading dislocation (TD) density which might be responsible for the increase in resistivity. A turn-on, turn-off effect is described and a memory effect which is responsible for a decrease of the surface quality of the samples. In situ annealing of the susceptor and the use of a clean liner after each growth run helps to reduce this effect and maintain the good quality of GaN layers. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | |||||||||||||||||||||||||