Absorption of Pulsed Terahertz and Optical Radiation in Earthworm Tissue and Its Heating Effect

The transmission of THz, near-infrared (1030 nm), and green (515 nm) pulses through Eisenia andrei body wall is studied, which consists of epithelial layer and circular and longitudinal muscles. Samples with the full-body cross-section were also investigated. The transmitted power for the green pulses followed the Beer-Lambert law of exponential attenuation for all thicknesses and tissue structures. Different body wall and body center absorption coefficients were found in case of infrared pulses. In the THz range, the body wall absorption coefficient steadily increases from about 80 cm–1 at 0.2 THz to about 273 cm–1 at 2.5 THz. Numerical estimation indicates that THz pulses of 5-μJ energy and 1-kHz repetition rate (5-mW average power) cause only a small temperature increase of about 0.4 K, suggesting that heating has minor contribution to biological effectiveness.

Numerical Analysis and Parameter Optimization of a Portable Two-Body Attenuator Wave Energy Converter

Easily portable, small-sized ocean wave energy converters (WECs) may be used in many situations where large-sized WEC devices are not necessary or practical. Power maximization for small-sized WECs amplifies challenges that are not as difficult with large-sized devices, especially tuning the device’s natural frequency to match the wave frequency and achieve resonance. In this study, power maximization is performed for a small-sized, two-body attenuator WEC with a footprint constraint of about 1m. A thin, submerged tuning plate is added to each body to increase added mass without significantly increasing hydrostatic stiffness in order to reach resonance. Three different body cross-section geometries are analyzed. Device power absorption is determined through time domain simulations using WEC-Sim with a simplified two-degree-of-freedom (2DOF) model and a more realistic three-degree-of-freedom (3DOF) model. Different drag coefficients are used for each geometry to explore the effect of drag. A mooring stiffness study is performed with the 3DOF model to investigate the mooring impact. Based on the 2DOF and 3DOF power results, there is not a significant difference in power between the shapes if the same drag coefficient is used, but the elliptical shape has the highest power after assigning a different approximate drag coefficient to each shape. The mooring stiffness study shows that mooring stiffness can be increased in order to increase relative motion between the two bodies and consequently increase the power.

Aerodynamic Characteristic Optimization on The Design of Anti - Ship Missile for Indonesian Fast - Attack Boat

Missile is one of Indonesia 7 self – reliant main weapon system programs. Therefore research on the anti – surface ship missile system concept had been carried out at the Faculty of Defense Technology, Defense University. This research aims to abtain optimal design of anti – ship missile concept from previous research, i.e. 2 stages cruise missile with diameter of 0.36 m, total length of 5.19 m, cruise flight altitude of 17 m, and cruise flight speed of 0.88 Mach. The optimation is done on the missile’s aerodynamics characteristics to maximize its lift to drag ratio, which is one of the factor that determine the missile’s performance. Variables of nose cone shapes, number of wings, and body cross sections were chosen for evaluation of lift to drag ratio. The research found that nose cone shape did not affect the aerodynamic characteristics since the flight speed is subsonic. From the rest of the variables, it is found that the best configuration is missile with 2 wings with root length of 1.18 m, height of 0.79 m, and tip length of 0.71 m, elliptical body cross section, and the missile is to be flown at 6o angle of attack.

The Basic Performance Analysis of the Rail Vehicle Body

The design and manufacture of the vehicle structure determines of the safety and suitability during operation. For most designers, the bearing capacity of the vehicle body is not completely understood. The initial estimate of the vehicle is simply a uniform simply supported overhang beam structure. With the development of computer technology, people can use more complex and closer to the actual body computational model, but it generally requires a lot of work, and designers are often only able to see the final result. It is not clear that the factors affect Load-carrying properties of the body structure. Designers often can not look find a process of improving the design. This method to scan the body structure by a computer calculation and analysis, the geometry, mechanical properties of parameters of the body cross-section has been plotted map. You can quickly and accurately understand the overall performance of the body, analysis the performance difference of different body cross-section. Reasonableness and balance of the body can be measured and awarded. In general, it is very important for the designer of the vehicle.

Influence of Fin Shape and Temperature on Conventional and Strained MuGFETs’ Analog Parameters

This work evaluates two important technological variations of Triple-Gate FETs: the use of strained silicon and the occurrence of non-rectangular body cross-section. The anaysis is focused on the electrical parameters for analog applications, and covers a temperature range from 150 K to 400 K. The comparison of the intrinsic voltage gain between the different trapezoidal fin shapes showed that the fin shape can have a major role in some analog parameters than the use of the strained silicon technology, helping to improve those parameters under certain circumstances. The highest intrinsic voltage gains were obtained for strained devices with top fin width larger than bottom at low temperature. Besides the intrinsic voltage gain, were also studied: the threshold voltage, subthreshold swing, drain induced barrier lowering, channel resistance, total harmonic distortion, transconductance, transconductance to drain current ratio, output conductance, Early voltage, drain voltage saturation and unity gain frequency.