Endosseous dental implant fractures an analysis of 21 cases

Implant fracture is an infrequent cause of implant failure. The present study evaluates 21 fractured implants, with an analysis of patient age and sex, the type, length and diameter of the implant, positioning in the dental arch, the type of prosthetic rehabilitation involved, the number of abutments and pontics, the presence or absence of distal extensions or cantilevers, and loading time to fracture. Implant fracture was more common in males than in females (15:4), and the mean patient age was 56.9 years. Most cases (n = 19) corresponded to implant-supported fixed prostheses - 16 with cantilevers of different lengths ? while only two fractured implants were supporting overdentures instead of fixed prostheses. The great majority of fractured implants (80.9%) were located in the molar and premolar regions, and most fractured within 3-4 years after loading. It is important to know and apply the measures required to prevent implant fracture, and to seek the best individualized solution for each case - though complete implant removal is usually the treatment of choice

Effect of Natural Pozzolan on Carbonation and Chloride Penetration in Sustainable Concrete

A study on green concrete as well as its durability is essential to promote the sustainable development of the concrete industry. Since the majority of concrete deterioration is connected to corrosion of reinforcement due to carbonation or chloride penetration into concrete, the influence of pozzolan through them must be investigated for concrete durability. This paper mainly focuses on the experimental study of the influence of Popa volcanic natural pozzolan on carbonation and chloride penetration process. The experimental tests are made on replacement of natural pozzolan 10%, 20%, 30% instead of cement and analysis show that optimized pozzolan replacement can promote on the mechanical strength of concrete along with time than reference concrete. According to the results, in the CO2 chamber and the natural condition, it contributes negatively to carbonation because the rate of carbonation increased as the amount of pozzolan increased. However, increasing the pozzolan content led to higher resistance of the concrete in chloride ion penetration

Evaluation of Safety Performance of Fractured Joints in Steel Truss Bridge

This study aims to evaluate safety performance of fractured joints and failure mechanisms of high-strength friction-grip (HSFG) bolted connections in steel bridge. As a case study, the bolted connections on the Ayeyarwady Bridge (Yadanarbon) in Myanmar have been investigated. Initial inspection of the bridge found that a number of bolts were loosened, missing or had already fractured and most were heavily corroded. The original fractured bolts have been replaced with the new ones as remedial work. The safety performance of fractured joints were evaluated based on simulation results of existing bridge by Midas Civil in accordance with AASHTO standards. The failure mechanisms of the fractured bolts were investigated by analyzing through optical and scanned electron microscopy. The main factors contributed to the failure of the bolted connections at the Ayeyarwady Bridge (Yadanarbon) include delayed fracture, stress corrosion cracking, the fluctuating loads, and the corrosive environment it was subjected to. The failure mechanisms of the fractured bolts were mainly due to pitting corrosion and fretting fatigue.

ミャンマー連邦北シャン州におけるメタンフェタミン覚醒剤の使用開始年齢と使用者のハイリスク性行動

学位の種別:課程博士University of Tokyo(東京大学

A Flow-based Method to Measure Traffic Statistics in Software Defined Network

Since software defined network became a revolution of network, many new developments and deployments are put forward. Device operating in software defined network environment will need a controller to store control policy. As a result of flow is one of traffic presentation units in software defined network, hence, this paper proposed a prototype of flow-based method to measure traffic statistics which can be used in OpenFlow network. By analysis of flow table, active flows which managed by controller can be listed, and information of each flow can be presented with developed module on the controller. After gathered port statistics from OpenFlow switch and entries in flow table, information of each flow can be presented on a developed graphic interface. By using this method, Traffic statistics of each flow may be more adaptive and realizable for measurement for observation

Study on Wind Flow Behaviours of High Rise Buildings with CFD Simulation

Wind distribution flows are very important for designer to develop new urban planning and new design buildings. The aim of this paper research was to investigate wind flow behaviours around the buildings cluster.  Present work used a three dimensional scale down model of buildings where transient flow analysis was done. CFD (Computational Fluid Dynamics) simulation is the main research method to investigate the wind environment around building complexes. Numerical investigation of air flow pattern around a cluster of existing high rise structures located in Mandalay city was carried out. It has been implemented through ANSYS Fluent 17.0 using SIMPLE algorithm as solver. Standard k- ɛ model was used for turbulence modelling. The inflow Basic Wind Speed in Mandalay is 80 mph. The inflow wind velocity profile with height is computed by power law equation and imposed by UDF (C+ program). This simulation was carried out to study the effect of wind directions on velocity distribution around the structures and wind pressure coefficient on the face of the L shape building. Analysis was performed at eight wind directions such as N, NE, E, SE, S, SW, W and NW. In these simulation results, high stream line velocities are especially entering into the east side of the Condo A building as obstacles on the wind pathway from the interval between Tower building and L-shape building. When wind strikes building, causing a positive pressure zone to be formed on the windward face and a negative pressure zone is created at the sides and leeward face of the building

Bis(μ-phenyl­methano­lato)bis­({4-[(E)-(4-tert-butyl­phen­yl)(2-pyrid­ylmethyl­imino)meth­yl]-3-methyl-1-phenyl-1H-pyrazol-5-olato}zinc(II))

In the title centrosymmetric dimeric ZnII complex, [Zn2(C27H27N4O)2(C7H7O)2], the ZnII center is coordinated by two N atoms and one O atom of the ketiminate ligand and two bridging O atoms of the benzyl­alkoxy groups. The geometry around the ZnII ions is distorted trigonal-bipyramidal

Assessment of HIV testing among young methamphetamine users in Muse, Northern Shan State, Myanmar

Background Methamphetamine (MA) use has a strong correlation with risky sexual behaviors, and thus may be triggering the growing HIV epidemic in Myanmar. Although methamphetamine use is a serious public health concern, only a few studies have examined HIV testing among young drug users. This study aimed to examine how predisposing, enabling and need factors affect HIV testing among young MA users. Methods A cross-sectional study was conducted from January to March 2013 in Muse city in the Northern Shan State of Myanmar. Using a respondent-driven sampling method, 776 MA users aged 18-24 years were recruited. The main outcome of interest was whether participants had ever been tested for HIV. Descriptive statistics and multivariate logistic regression were applied in this study. Results Approximately 14.7% of young MA users had ever been tested for HIV. Significant positive predictors of HIV testing included predisposing factors such as being a female MA user, having had higher education, and currently living with one’s spouse/sexual partner. Significant enabling factors included being employed and having ever visited NGO clinics or met NGO workers. Significant need factors were having ever been diagnosed with an STI and having ever wanted to receive help to stop drug use. Conclusions Predisposing, enabling and need factors were significant contributors affecting uptake of HIV testing among young MA users. Integrating HIV testing into STI treatment programs, alongside general expansion of HIV testing services may be effective in increasing HIV testing uptake among young MA users

The Development of Spatial Attention U-Net for The Recovery of Ionospheric Measurements and The Extraction of Ionospheric Parameters

We train a deep learning artificial neural network model, Spatial Attention U-Net to recover useful ionospheric signals from noisy ionogram data measured by Hualien's Vertical Incidence Pulsed Ionospheric Radar. Our results show that the model can well identify F2 layer ordinary and extraordinary modes (F2o, F2x) and the combined signals of the E layer (ordinary and extraordinary modes and sporadic Es). The model is also capable of identifying some signals that were not labeled. The performance of the model can be significantly degraded by insufficient number of samples in the data set. From the recovered signals, we determine the critical frequencies of F2o and F2x and the intersection frequency between the two signals. The difference between the two critical frequencies is peaking at 0.63 MHz, with the uncertainty being 0.18 MHz.Comment: 17 pages, 7 figures, 3 table

Critical Behavior of Frustrated Josephson Junction Arrays with Bond Disorder

The scaling behavior of the current-voltage ($IV$) characteristics of a two-dimensional proximity-coupled Josephson junction array (JJA) with quenched bond disorder was investigated for frustrations $f=1/5$, 1/3, 2/5, and 1/2. For all these frustrations including 1/5 and 2/5 where a strongly first-order phase transition is expected in the absence of disorder, the $IV$ characteristics exhibited a good scaling behavior. The critical exponent $\nu$ indicates that bond disorder may drive the phase transitions of frustrated JJA's to be continuous but not into the Ising universality class, contrary to what was observed in Monte Carlo simulations. The dynamic critical exponent $z$ for JJA's was found to be only 0.60 - 0.77.Comment: RevTeX4, 4 pages, 4 figures, the manuscript is replaced with the published versio