End Sealing Research Articles

Comparison of Root End Sealing Ability of Three Retrograde Filling Materials in Teeth with Root Apices Resected at 90° using Dye Penetration Method under Fluorescent Microscope: An In-vitro Study

Background: Inadequate seal at the apex is the substantial cause for surgical endodontic dissatisfaction. The retrograde filling material which is used should prevent the egress of potential contaminants into periradicular tissue.
 Objectives: To evaluate the ability of MTA Angelus, Zirconomer and Bioactive bone cement to seal the root end as retrograde filling material; and to compare root end sealing ability of these three different retrograde filling materials with apices resected at 900 angles using dye penetration method under fluorescent microscope.
 Methodology: Thirty six extracted upper anterior teeth are to be cut horizontally at the CEJ. After following the standard protocols of, “cleaning, shaping and obturation” with gutta percha and “AH Plus sealer”, the samples will be resected 3mm at the apical end at 90 degree angle along the long axis of the tooth with the help of diamond disc. A root end cavity of depth 3mm will be made with Diamond coated ultrasonic surgical tip S12 90 ND. The teeth will be randomly categorized in 3 groups: Group 1: MTA angelus; Group 2: Zirconomer; Group 3: Bioactive Bone Cement. Following which the roots to be coated with nail varnish except the tip. Each material will be compressed in the root end cavity with the help of small pluggers. All the samples which are retrofilled will be kept in acrydine orange for a duration of 24 hours, following which cleaning & bucco-lingual sectioning(vertical) will be done. Fluorescent microscope will be used for observation of sectioned root samples.
 Expected Results: Bioactive bone cement is expected to have better sealing ability of the retrograde cavity preparation with minimal or no microleakage followed by MTA Angelus and then Zirconomer.
 Conclusion: If this study proves correct, this would be helpful for the clinicians to choose better and the most efficient retrograde filling material with best sealing ability and minimal microleakage in a retrograde preparation which will aid in success of the root canal treatment further resolving the infection.

Availability analysis of Tube Light Manufacturing industry using numerical technique

Continuous improvement in the performance of any industrial system is highly desirable. But failure is an inevitable phenomenon. In order to run industrial systems without failure reliability and availability of each subsystem needs to be maintained. So the maintenance of the working units of the system plays a very important role to make system available for a pre define period of time. The system performance can be increased to the maximum extent by adopting the suitable maintenance strategy. In this paper a computational technique is used for the analysis of Time Dependant System Availability (TDSA) of Tube Light manufacturing system has been addressed.. This system comprises of seven subsystems namely End Sealing cum Coating Machine, Baker Machine, Wiper Machine, Sealing Machine and Exhaust Machine, Capping Machine and Activator machine. Mathematical formulation of the system is done using Markov Approach (MA). The model has been solved TDSA with the help of Adaptive step size control Runge-Kutta Method. After carrying out the TDSA analysis it is found that subsystem- II i.e Baker machine is critical subsystem having more effect on TDSA of the system on basis of repair rate on as compared to other subsystems. Further, present research is also helpful in deciding maintenance repair priorities of different subsystems.

Effects of rotor surface texture on rotary vane actuator end sealing performance

Abstract The dynamic pressure oil film is difficult to form between the end seal ring and the rotor during the hydraulic rotary vane actuator (RVA) operates, which results in the sealing surfaces sustain severe friction and wear. Thus, a series of circular micro-dimples was processed on the rotor surface using laser surface texturing technology to reduce these. The mathematical model of the end seal was established based on the fluid dynamic lubrication equation. In the meanwhile, the friction torque and leakage between the sealing clearances were calculated. In addition, verification experiments were performed. The results showed that the rotor surface texture can effectively improve the RVA end sealing performance under lubricated conditions.

Comparison of the Root End Sealing Ability of Four Different Retrograde Filling Materials in Teeth with Root Apices Resected at Different Angles - An Invitro Study.

Insufficient apical seal is the significant reason for surgical endodontic disappointment. The root-end filling material utilized should avoid egress of potential contaminants into periapical tissue. The aim of this study was to compare the sealing ability of four root-end filling materials MTA, Portland cement, IRM, RMGIC in teeth with root apices resected at 0 and 45 angle using dye penetration method under fluorescent microscope. Hundred extracted human maxillary anterior teeth were sectioned horizontally at the cement-enamel junction. After cleaning, shaping and obturation with gutta-percha and AH Plus sealer, the tooth samples were randomly divided in two groups (the root apices resected at 0° and 45° to the long axis of the root). The root resections were carried out by removing 2 mm and 1 mm in both the groups. Following which 3 mm deep root-end cavities were prepared at the apices and the root were coated with nail varnish except the tip. The teeth in both the group were randomly divided into four subgroups each (Pro root MTA, Portland cement, IRM and Light cure nano GIC Ketac N-100). All the retrofilled samples were stored in acrydine orange for 24 hours after which they were cleaned and vertically sectioned buccolingually. The sectioned root samples were observed under fluorescent microscope. The root apex sealing ability of Mineral Trioxide Aggregate (MTA) was superior to Portland cement, Intermediate Restorative Material (IRM) and LC GIC. IRM demonstrated the maximum apical leakage value among all the materials. Portland cement and LC GIC showed comparable sealing ability. The angulation whether 0° or 45° angle did not affect the sealing ability of all the four materials used, MTA proved to be one of the superior materials for root-end filling.

Effect of Tree Species and End Seal on Attractiveness and Utility of Cut Bolts to the Redbay Ambrosia Beetle and Granulate Ambrosia Beetle (Coleoptera: Curculionidae: Scolytinae)

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a non-native invasive pest and vector of the fungus that causes laurel wilt disease in certain trees of the family Lauraceae. This study assessed the relative attractiveness and suitability of cut bolts of several tree species to X. glabratus. In 2009, female X. glabratus were equally attracted to traps baited with swampbay (Persea palustris (Rafinesque) Sargent) and camphortree (Cinnamomum camphora (L.) J. Presl), which were more attractive than avocado (Persea americana Miller), lancewood (Ocotea coriacea (Swartz) Britton), and sweetbay (Magnolia virginiana L.). These species were more attractive than loblolly bay (Gordonia lasianthus (L.) J. Ellis). X. glabratus entrance hole density and emergence from caged bolts were highest on swampbay and camphortree. In 2010, swampbay was significantly more attractive to X. glabratus than sassafras (Sassafras albidum (Nuttall) Nees), yellow poplar (Liriodendron tulipifera L.), and eastern redbud (Cercis canadensis L.). Sassafras bolts end sealed with a liquid wax-and-water emulsion were more attractive to X. glabratus than end-sealed bolts of yellow poplar and redbud. Relative to unsealed bolts, end seal decreased X. glabratus entrance hole density on swampbay and decreased granulate ambrosia beetle (Xylosandrus crassiusculus (Motschulsky)) trap catch, entrance hole density, and adult emergence from swampbay. X. crassiusculus was not attracted to sassafras, yellow poplar, and redbud and was not more attracted to manuka oil than to unbaited traps. Sassafras was more attractive to X. glabratus than previously reported and supported reproducing populations of the insect. End sealing bolts with a wax-and-water emulsion may not be optimal for attracting and rearing ambrosia beetles in small logs.

Movement of hot loads due to their heat

Construction of a cooled container is presented with a detachable loading vessel and a sealed heat exchange cavity. With the aim of increasing the endurance of the end sealing under high temperature conditions and reducing air flow through the container the end seal it is made in the form of a circular collector with a steam generator with circular orifice, that is directed at an angle to the wall of the pipeline and in a direction opposite to container movement.

Identification of Force Coefficients in a Squeeze Film Damper With a Mechanical End Seal—Centered Circular Orbit Tests

The damping capability of squeeze film dampers (SFDs) relies on adequate end sealing to prevent air ingestion and entrapment. The paper presents the parameter identification procedure and force coefficients of a test SFD featuring a mechanical seal that effectively eliminates lubricant side leakage. The test damper reproduces an aircraft application intended to contain the lubricant in the film lands for extended periods of time. The test damper journal is 2.54cm in length and 12.7cm in diameter, with a nominal clearance of 0.127mm. The SFD feed end is flooded with oil, while the discharge end contains a recirculation groove and four orifice ports. In a companion paper (San Andrés and Delgado, 2006, ASME J. Eng. Gas Turbines Power, 119, to be published) single frequency–unidirectional load excitation tests were conducted, without and with lubricant in the squeeze film lands, to determine the seal dry-friction force and viscous damping force coefficients. Presently, tests with single frequency excitation loads rendering circular centered orbits excitations are conducted to identify the SFD force coefficients. The identified parameters include the overall system damping and the individual contributions from the squeeze film, dry friction and structural damping. The identified system damping coefficients are frequency and motion amplitude dependent due to the dry friction interaction at the mechanical seal interface. Identified squeeze film force coefficients, damping, and added mass, are in good agreement with predictions based on the full film, short length damper model.

Identification of Force Coefficients in a Squeeze Film Damper With a Mechanical End Seal—Part I: Unidirectional Load Tests

Squeeze film dampers (SFDs) with low levels of external pressurization and poor end sealing are prone to air entrapment, thus not generating enough damping capability. Single frequency, unidirectional load tests were conducted on a SFD test rig replicating a commercial jet-engine configuration. The damper journal is 2.54cm in length and 12.7cm in diameter, with nominal clearance of 0.127mm. The SFD feed end is flooded with oil, while the discharge end contains a recirculation groove and four orifice ports, and a mechanical seal ring in contact with the damper journal. A wave spring pushes the ring ensuring tight sealing to prevent gas ingestion. The mechanical seal also serves to contain the lubricant within the squeeze film land for extended periods of time and; while in operation, to prevent contamination of the ball bearing cartridge. The measurements conducted without and with lubricant in the squeeze film lands, along with a frequency domain identification procedure, render the mechanical seal dry-friction force and viscous damping force coefficients as functions of frequency and motion amplitude. The end seal arrangement is quite effective in eliminating side leakage and preventing air entrainment into the film lands. Importantly enough, the dry friction force, arising from the contact forces in relative motion, increases significantly the test element equivalent viscous damping coefficients. The identified system damping coefficients are thus frequency and motion amplitude dependent, albeit decreasing rapidly as the motion parameters increase. Identified squeeze film force coefficients, damping and added mass, agree well with predictions based on the full film, short length damper model.

Temperature Pattern and Thermal Distortion in End Sealing Rings

Temperature Pattern and Thermal Distortion in End Sealing Rings

Single step end seal and retention gap procedure for preparation of fused silica capillary columns

We have used this end sealing technique on over fifty fused silica columns ranging in internal diameter from 0.1 mm to 0.54 mm. Only two of these were unsatisfactory and required resealing. We have also used the technique on a few glass capillaries and found it to work equally well. The procedure is simple, quick, effective, and allows for the incorporation of a retention gap when desired

VOC Emission Controls for Can End Sealing Compounds

Regulations require that emissions of VOC from the application of can end sealing compounds be limited to 440 grams per liter. One can manufacturer has investigated the cost and feasibility of a VOC capture/control system and the availability and efficacy of water-based and high solids end sealing compounds. After characterizing and optimizing VOC evaporation rates, a prototype VOC containment system was tested on one can end sealing compound line. An 83 percent VOC capture efficiency was obtained at approximately 950 acfm. A cost analysis for a full facility capture and control system gave cost-effectiveness values of $1.21 to $2.36 per pound of VOC controlled. An evaluation oflow-VOC end sealing compounds, including long term pack tests, produced a water-based compound that could be implemented on pet food can ends by early 1986. Continuation of pack tests could allow full facility conversion to zero VOC water-based compounds by mid- to late-1987. Using an innovative averaging technique, the can manufac...