Orthodontic Camouflage in Skeletal Class III Malocclusion: A Contemporary Review

Early orthopedic intervention can be effective in normalizing skeletal class III malocclusions if patients are treated in a timely manner. There are a large number of skeletal class III patients that either decline or cannot afford surgical treatment. The only alternative is ‘Orthodontic camouflage’ through comprehensive treatment with fixed appliances. The ultimate judgment as to whether orthodontic treatment alone, to camouflage a skeletal problem, would be an acceptable result, or whether orthognathic surgery to correct the jaw discrepancy would be required, must be made by the patient and parents. Class III camouflage logically would be the reverse of class II camouflage, based on retracting the lower incisors, advancing the upper incisors, and surgically reducing the prominence of the chin, in addition, rotating the mandible downward and backward, when the chin is prominent, can be considered a form of camouflage. Even though timing of orthodontic treatment has always been somewhat controversial, it is an agreement in the literature that prognosis is still obscure until growth is completed. A cephalometric analysis is needed to quantitatively record the severity of the class III malocclusion and to determine the underlying cause of the deformity. Although it is agreed that camouflage line of treatment is not an ideal lineof treatment, but it serves its purpose very well in mild rangeof skeletal dysplasia’s and in conditions where patient is eitherunwilling for orthognathic surgery or in cases were surgery iscontraindicated

Reverse-Traditional/Hands-On: An Alternative Method of Teaching Statistics

This paper presents a method for teaching statistics called the Reverse-Traditional/Hands-On (RT/HO) method. The method includes student-generated data, use of a statistical computing package such as MINITAB to introduce statistical terms and methods, and a statistical research component. An analytic comparison of students’ successes in courses using the Traditional and RT/HO methods is presented

Accuracy of impressions with different impression materials in angulated implants

Purpose: To evaluate the dimensional accuracy of the resultant (duplicative) casts made from two different impression materials (polyvinyl siloxane and polyether) in parallel and angulated implants.Materials and Methods: Three definitive master casts (control groups) were fabricated in dental stone with three implants, placed at equi-distance. In first group (control), all three implants were placed parallel to each other and perpendicular to the plane of the cast. In the second and third group (control), all three implants were placed at 10° and 15° angulation respectively to the long axis of the cast, tilting towards the centre. Impressions were made with polyvinyl siloxane and polyether impression materials in a special tray, using a open tray impression technique from the master casts. These impressions were poured to obtain test casts. Three reference distances were evaluated on each test cast by using a profile projector and compared with control groups to determine the effect of combined interaction of implant angulation and impression materials on the accuracy of implant resultant cast.Results: Statistical analysis revealed no significant difference in dimensional accuracy of the resultant casts made from two different impression materials (polyvinyl siloxane and polyether) by closed tray impression technique in parallel and angulated implants.Conclusion: On the basis of the results of this study, the use of both the impression materials i.e., polyether and polyvinyl siloxane impression is recommended for impression making in parallel as well as angulated implants.Key words: Angulated implants, implant impression, impression accuracy, impression materia

Impact of soft magnetic material on design of high speed permanent magnet machines

This paper investigates the effect of two soft magnetic materials on a high speed machine design, namely 6.5% Silicon Steel and Cobalt-Iron alloy. The effect of design parameters on the machine performance as an aircraft starter-generator is analysed. The material properties which include B-H characteristics and the losses are obtained at different frequencies under an experiment and used to predict the machine performance accurately. In the investigation presented in this paper, it is shown that machines designed with 6.5% Silicon Steel at a high core flux density has lower weight and lower losses than the Cobalt-Iron alloy designs. This is mainly due to the extra weight contributed by the copper content especially in the end-windings. Due to the high operating frequencies, the core-losses in the Cobalt-Iron machine designs are found to outweigh the copper-losses incurred in the Silicon Steel machines. It is also shown that change in stack length/number of turns has a considerable effect on the copper losses at starting, however has no significant advantage on rated efficiency which happens to be in a field-weakening operating point. It is also shown that the performance of the machine designs depend significantly on material selection and the operating point of the core. The implications of the variation of design parameters on the machine performance is discussed and provides insight into the influence of parameters that effect overall power density

Effect of Salt Coatings on Low Cycle Fatigue Behavior of Nickel -base Superalloy GTM-SU-718

AbstractNickel-base superalloys are used as components of gas turbines both of jet engines as well as marine engines. Sin e these components are subjected to high temperature and oxidizing environment, their performance is drastically affected by the environmental conditions. Marine environment further aggravates the situation due to presence of salt (NaCl) particles in air. This salt along with sulphur and vanadium present in the fuel oil, leads to formation of compounds like sodium sulfate (Na2SO4) and vanadium pentaoxide (V2O5) during combustion and causes hot corrosion and stress corrosion cracking of engine components. Strain controlled low cycle fatigue tests were conducted on the nickel base superalloy GTM-SU-718 in air, at room temperature on unexposed, exposed at 550°C for 25h, exposed at 650°C for 25h as well as on the specimens coated with layers of NaCl, 25wt.%NaCl+75wt.%Na2SO4 and 90wt.%Na2SO4+5wt.%NaCl+5wt.%V2O5 salt/salt mixtures separately and exposed at elevated temperatures for 25h. While the NaCl coated sample was exposed at 550°C, those coated with other two salt mixtures were exposed at 650°C. It was observed that fatigue life of the NaCl coated sample, exposed at 550°C for 25h was reduced, however, there was little effect on fatigue life of the other specimens referred to above, including even those coated with salt mixtures and exposed at 650°C

High speed solid rotor permanent magnet machines: concept and design

This paper proposes a novel solid rotor topology for an Interior Permanent Magnet (IPM) machine, adopted in this case for an aircraft starter-generator design. The key challenge in the design is to satisfy two operating conditions which are: a high torque at start and a high speed at cruise. Conventional IPM topologies which are highly capable of extended field weakening are found to be limited at high speed due to structural constraints associated with the rotor material. To adopt the IPM concept for high speed operation, it is proposed to adopt a rotor constructed from semi-magnetic stainless steel, which has a higher yield strength than laminated silicon steel. To maintain minimal stress levels and also minimize the resultant eddy current losses due to the lack of laminations, different approaches are considered and studied. Finally, to achieve a better tradeoff between the structural and electromagnetic constraints, a novel slitted approach is implemented on the rotor. The proposed rotor topology is verified using electromagnetic, static structural and dynamic structural Finite Element (FE) analyses. An experiment is performed to confirm the feasibility of the proposed rotor. It is shown that the proposed solid rotor concept for an IPM fulfils the design requirements whilst satisfying the structural, thermal and magnetic limitations

Intersections of Schubert varieties and eigenvalue inequalities in an arbitrary finite factor

It is known that the eigenvalues of selfadjoint elements a,b,c with a+b+c=0 in the factor R^omega (ultrapower of the hyperfinite II1 factor) are characterized by a system of inequalities analogous to the classical Horn inequalities of linear algebra. We prove that these inequalities are in fact true for elements of an arbitrary finite factor. A matricial (`complete') form of this result is equivalent to an embedding question formulated by Connes.Comment: 41 pages, many figure

Clean Energy Scorecard for Mountain West Cities, 2020

As climate change continues to affect the Mountain West, many cities are taking measures to reduce carbon emissions and dependence on fossil fuels. This fact sheet reports the rankings of Mountain West municipal governments, based on efforts to improve energy efficiency and increase their utilization of clean energy. The rankings are collected from the American Council for an Energy-Efficient Economy’s (ACEEE) “2020 City Clean Energy Scorecard.

College-Educated Young Adults in the Mountain West

This fact sheet examines data originally published in “The Young and Restless and the Nation’s Cities,” a report prepared by Joe Cortright for the City Observatory. The original report explores the percentage of college-educated young adults (or individuals aged 25 to 34 with a bachelor’s degree), as well as the percentage these individuals made up of the total population in each metro area between 2000 and 2012. This fact sheet explores data for the following Mountain West places, as reported by the original source: Denver CSA (Combined Statistical Area) Phoenix-Mesa-Glendale, AZ Metro Area Las Vegas-Paradise, NV Metro Area Salt Lake City, UT Metro Are

Tunable hybrid surface waves supported by a graphene layer

We study surface waves localized near a surface of a semi-infinite dielectric medium covered by a layer of graphene in the presence of a strong external magnetic field. We demonstrate that both TE-TM hybrid surface plasmons can propagate along the graphene surface. We analyze the effect of the Hall conductivity on the disper- sion of hybrid surface waves and suggest a possibility to tune the plasmon dispersion by the magnetic field.Comment: 3 pages, 3 figure