Effect of Water Immersion on The Resistance to Sliding of Coated Orthodontic Archwires

Objectives: The objective of this in vitro study is to compare the resistance to sliding (RS) of coated and uncoated orthodontic archwires in ceramic brackets at various water-immersion times and bracket angulations. Background: Tooth-colored orthodontic systems have been developed to meet the patient’s esthetic needs. Ceramic brackets and polymer-coated archwires have been shown to demonstrate higher RS than metal brackets and archwires in dry conditions. However, there is no study to address the RS of coated archwires depending on water-immersion times as in the oral cavity. Therefore, it is necessary to examine RS of coated archwires sliding in ceramic brackets up to 4 weeks of water immersion. Methods: Four groups of 0.019 x 0.025inch stainless-steel archwires: uncoated (group U), Parylene-coated (group P), epoxy-coated (group E), and Teflon-coated (group T) were used. They were immersed for 0 week (T0), 2 weeks (T2), and 4 weeks (T4), in distilled deionized water at 37°C. The RS was measured by sliding the archwires in 0.022inch-slot sapphire ceramic brackets in 0° or 3° bracket angulation. Two general linear models were created to look for differences in RS with Tukey’s HSD for all post-hoc comparisons. The integrity of the archwires was observed under microscope after the sliding test. Results: At 0° bracket angulation, there was no difference in RS between T0, T2, and T4 in groups T & U. In group P, RS at T4 was higher than RS at T0 & T2. In group E, RS at T2 was higher than RS at T0 & T4. At 3° bracket angulation, there was no difference in RS between T0, T2, and T4 in groups P & U. In groups T & E, RS at T4 was highest following RS at T0, and RS at T2 in descending order. All groups showed a higher RS at 3° bracket angulation than RS at 0° bracket angulation in all water immersion times, with exceptions of group T at T2 as no difference was noticed between two bracket angulations, and of group E at T2 as RS at 3° was lower than RS at 0°. Comparing to other groups, group P showed the highest RS in various bracket angulations and water-immersion times. At 0° bracket angulation, group T showed less percentage of coating delamination than the other groups after sliding test. At 3° bracket angulation, all archwires of all groups showed similar coating delamination after sliding test. Conclusions: Resistance to sliding was changed when coated archwires were immersed in water for periods of time. Among the independent variables, surface coating and bracket angulation played a major role in the resistance to sliding

SDN-based Coordination for IoT-Cloud Connectivity employing Wired/Wireless Multi-Access SmartX Boxes

Diversified Internet of Things (IoT) -related services typically require networking to the cloud/edge-cloud resources to process and store data from distributed IoT device boxes. In addition, various IoT-related services encourage leveraging different access networking, so IoT device boxes having multiple interfaces are becoming typical configuration. In order to efficiently provide IoT-cloud connectivity via multiple interfaces, multi-access networking is becoming a popular research keyword. And supporting reliable data transmission  of IoT data to the cloud is an important feature of multi-access networking. In this paper, to cope with the emerging multi-access networking, we propose SmartX miniBox and SDN-based coordination functionality. SmartX miniBox is a physical box designed to support multi-access networking with SDN-enabled wired interface and OVS-integrated WiFi interfaces. And SDN-based Coordination functionality coordinates SmartX miniBox and IoT device boxes in order to enhance reliability in data transmission. The coordination includes alternating access interfaces in IoT devices boxes and changing networking paths in multi-path wired topology when networking failures occur

An asymptotic analysis of composite beams with kinematically corrected end effects

AbstractA finite element-based beam analysis for anisotropic beams with arbitrary-shaped cross-sections is developed with the aid of a formal asymptotic expansion method. From the equilibrium equations of the linear three-dimensional (3D) elasticity, a set of the microscopic 2D and macroscopic 1D equations are systematically derived by introducing the virtual work concept. Displacements at each order are split into two parts, such as fundamental and warping solutions. First we seek the warping solutions via the microscopic 2D cross-sectional analyses that will be smeared into the macroscopic 1D beam equations. The variations of fundamental solutions enable us to formulate the macroscopic 1D beam problems. By introducing the orthogonality of asymptotic displacements to six beam fundamental solutions, the end effects of a clamped boundary are kinematically corrected without applying the sophisticated decay analysis method. The boundary conditions obtained herein are applied to composite beams with solid and thin-walled cross-sections in order to demonstrate the efficiency and accuracy of the formal asymptotic method-based beam analysis (FAMBA) presented in this paper. The numerical results are compared to those reported in literature as well as 3D FEM solutions

Tsunami Flooding Probability determined by Probability Distribution Type

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Temperature dependence of Mott transition in VO_2 and programmable critical temperature sensor

The temperature dependence of the Mott metal-insulator transition (MIT) is studied with a VO_2-based two-terminal device. When a constant voltage is applied to the device, an abrupt current jump is observed with temperature. With increasing applied voltages, the transition temperature of the MIT current jump decreases. We find a monoclinic and electronically correlated metal (MCM) phase between the abrupt current jump and the structural phase transition (SPT). After the transition from insulator to metal, a linear increase in current (or conductivity) is shown with temperature until the current becomes a constant maximum value above T_{SPT}=68^oC. The SPT is confirmed by micro-Raman spectroscopy measurements. Optical microscopy analysis reveals the absence of the local current path in micro scale in the VO_2 device. The current uniformly flows throughout the surface of the VO_2 film when the MIT occurs. This device can be used as a programmable critical temperature sensor.Comment: 4 pages, 3 figure

Simulation of Flood Propagation Due to Levee Break Using the Cartesian Cut Cell Method

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Semi-analytical study of transient electroosmotic flow of Maxwell fluids in nanochannels grafted with a strong polyelectrolyte layer having layered distribution of charges

We theoretically study transient electroosmotic flow of general Maxwell fluids through polyelectrolyte grafted nanochannel with a layered distribution of charges. By applying the method of Laplace transform, we semi-analytically obtain transient electroosmotic flow from Cauchy momentum equation and Maxwell constitutive equation. For nanochannels grafted with polyelectrolyte layers having different layered distribution of charges, we study the influence of dimensionless relaxation time, dimensionless polyelectrolyte layer thickness and dimensionless drag coefficient on transient electroosmotic flow. We verify that adjusting charge distributions of the layer can control intentionally the direction of the flows as well as strength of electroosmotic flow