Smart Walker

The Smart Walker is a roller walker that provides assistance for elders who are visually challenged. Every time the elders are on a stroll, the product will allow the elders to get alerted, whenever there is an obstacle ahead on the road, with a sound and visual notification on the screen of a smartphone or a tablet attached to the product.  Our product will include distance sensor to detect an obstacle, a camera to capture the picture and a brake system for emergency purposes. Elders can use their own smartphone or a tablet and run our Android application to access all the information, which will be transferred via Bluetooth

Fracture Toughness Characteristics of High-Manganese Austenitic Steel Plate for Application in a Liquefied Natural Gas Carrier

High-manganese austenitic steel was developed to improve the fracture toughness and safety of steel under cryogenic temperatures, and its austenite structure was formed by increasing the Mn content. The developed high-manganese austenitic steel was alloyed with austenite-stabilizing elements (e.g., C, Mn, and Ni) to increase cryogenic toughness. It was demonstrated that 30 mm thickness high-manganese austenitic steel, as well as joints welded with this steel, had a sufficiently higher fracture toughness than the required toughness values evaluated under the postulated stress conditions. High-manganese austenitic steel can be applied to large offshore and onshore LNG storage and fuel tanks located in areas experiencing cryogenic conditions. Generally, fracture toughness decreases at lower temperatures; therefore, cryogenic steel requires high fracture toughness to prevent unstable fractures. Brittle fracture initiation and arrest tests were performed using 30 mm thickness high-manganese austenitic steel and SAW joints. The ductile fracture resistance of the weld joints (weld metal, fusion line, fusion line + 2 mm) was investigated using the R-curve because a crack in the weld joint tends to deviate into the weld metal in the case of undermatched joints. The developed high-manganese austenitic steel showed little possibility of brittle fracture and a remarkably unstable ductile fracture toughness

Fracture Toughness Characteristics of High-Manganese Austenitic Steel Plate for Application in a Liquefied Natural Gas Carrier

High-manganese austenitic steel was developed to improve the fracture toughness and safety of steel under cryogenic temperatures, and its austenite structure was formed by increasing the Mn content. The developed high-manganese austenitic steel was alloyed with austenite-stabilizing elements (e.g., C, Mn, and Ni) to increase cryogenic toughness. It was demonstrated that 30 mm thickness high-manganese austenitic steel, as well as joints welded with this steel, had a sufficiently higher fracture toughness than the required toughness values evaluated under the postulated stress conditions. High-manganese austenitic steel can be applied to large offshore and onshore LNG storage and fuel tanks located in areas experiencing cryogenic conditions. Generally, fracture toughness decreases at lower temperatures; therefore, cryogenic steel requires high fracture toughness to prevent unstable fractures. Brittle fracture initiation and arrest tests were performed using 30 mm thickness high-manganese austenitic steel and SAW joints. The ductile fracture resistance of the weld joints (weld metal, fusion line, fusion line + 2 mm) was investigated using the R-curve because a crack in the weld joint tends to deviate into the weld metal in the case of undermatched joints. The developed high-manganese austenitic steel showed little possibility of brittle fracture and a remarkably unstable ductile fracture toughness

FIELD-INDUCED THZ WAVE EMISSION WITH NANOMETER RESOLUTION

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Robust Thin-Film Wire-Grid THz Polarizer Fabricated Via a Low-Cost Approach

A robust thin-film wire-grid terahertz (THz) polarizer was fabricated via a low-cost, mass-producible manufacturing approach. This polarizer is built on a very thin silica layer structurally supported by a silicon substrate. In addition, the metal grating is protected by a polymer thin film, which eliminates the multireflection effect and enhances the robustness of the polarizer for easy packaging. The polarizer can be easily mounted onto a Newport rotation holder for immediate use. A THz time-domain spectrometer is used to characterize its performance, and an excellent agreement is found between the FDTD-simulated results and the experimental results. The polarizer offered 20-40 dB and 0.8 dB of extinction ratio and transmission loss over a frequency range of 0.2-2.0 THz, respectively

Terahertz properties of liquid crystals

Liquid crystals (LCs) represent a very interesting material in the visible range but their properties in the terahertz (THz) range have not been extensively investigated yet. In this paper, we have investigated the THz properties of a set of LCs E7, BL037, and RDP97304 using terahertz time-domain spectroscopy. Refractive indices and absorption coefficients of ordinary and extraordinary axis of LCs are extracted from the measurements. We find that RDP97304 has the largest birefringence and smallest absorption in the THz range compared to E7 and BL037. Thus, RDP97304 is useful for developing efficient and fast THz devices