Numerical Study of Extremely Wideband-Modified Biconical Radiation Structures for Electronic Support Measures Application

Using the finite difference time domain (FD-TD) method, this paper studies radiation structures that can have multiple tunable frequency bands between 0.4 GHz and 4 GHz, a fixed band in [3.97, 5.36] GHz and an extremely wideband from 6.14 GHz to 68.27 GHz, where a frequency band is defined by the voltage standing wave ratio (VSWR) less than or equal to two. The base radiation structure has a modified-biconical antenna configuration, called base MBA, and is fed by a square-coaxial line with characteristic impedance close to 50 ohms. A dielectric ring and an outer dielectric cover are used between the two modified cones to enlarge the frequency band and strengthen the structure. An equal number of metallic-rings can be stacked at both circular-ends of cones in the base MBA to tune the positions of the frequency bands that are lower than 4 GHz and to alter their vertical polarization (V-pol) patterns. However, compared with those of the base MBA, these stacked metallic rings do not make significant changes to the VSWR in the [3.97, 5.36] GHz and [6.14, 28.27] GHz bands and the radiation patterns in the [6.14, 28.27] GHz band. The simulation results show that the base MBA and its metallic-ring-loaded versions all have V-pol radiation characteristics at all frequency bands and have donut-shaped omnidirectional patterns only when the wavelength is bigger than the length of the structure. When the wavelength is less than the size of the radiation structure, the donut shape is modified with ripples on the V-pol radiation pattern. Sometimes deep notches could be observed when MBAs operated at the higher end of the extremely wideband. A 0.2 mm cube was used to construct the antenna structures with the consideration of using the 3D metal/dielectric printer technology to build the antennas in the future.

Plate-impact-driven ring expansion test (PIDRET) for dynamic fragmentation

A new experimental set-up mounted at the muzzle of a singlestage gas gun has been designed in order to study the fragmentation of metallic rings under dynamic radial expansion. This concept takes advantage of the quasi-incompressibility of HDPE whose radial flow under plate impact-like loading is used to apply a pressure boundary condition at the ring’s inner surface. For the experimental configurations considered in the present work, the average strain rate in the ring reaches values close to 104 s-1. The repeatability and the reliability of the experiments are verified for rings made of steel and aluminium.

Reconfigurable Antenna Design for Dual Band to Operate in UWB Applications

Reconfigurable antennas wires are equipped for working in various groups by recurrence re-configurability or polarization re-configurability. A recurrence reconfigurable fix reception apparatus with two rectangular metallic rings is utilized by changing the transmitting surface of antenna. The switches are presented at the focal point of the essential fix. This antenna can work in 1.8 GHz, 2.2 GHz and 2.7GHz recurrence groups, when the switches are turned ON and OFF. The emanating surface zone increments when the switches are turned ON and thus change the working recurrence of antenna. The switches are displayed for equal circuit of PIN diodes. In this paper the radio wire can work from 1.8GHz to 2.7 GHz. The antenna is created and reproduced in HFSS Software.

About Metal Rings of the “Zubovsky-Vozdvizhenskaya Type” Adorned with Sculptured Anthropomorphic and Zoomorphic Images

Metallic rings with sculpture images of anthropomorphic and zoomorphic types are known from the turn of the 19th and 20th centuries amongst findings in Sarmatian burials of “Golden Cemetery” burial ground in the region of the Kuban river. These days they present a distinctive feature of the material culture of the Zubovsky-Vozdvizhenskaya group sites. Some analogous artifacts were found in mounds of the Volga river and Don river regions. There is no single definition for the functional use of such rings. The main reason for that is the fact that they had been found mostly in graves plundered in ancient times. The researchers assume them to be finials for some wooden structure, supports for vessels or elements of horsey harness. The hypothesis concerning harness seems to be better justified. In his first reports about findings of the rings with sculptured images N.I. Veselovskiy mentioned some fragments of leather remaining around the rings. Since in many cases those findings form pairs, it seems reasonable to assume them to be some symmetrical distributors of the belts for the horsey head harness.

Assessment of the Carcass Role in Designing Deepwater Riser Connectors

Technically, in deep water, the most challenging task is the end-fitting design of pipes. This connector has two main functions: It ensures sealing of the pipe fluid and transfers the loads from the pipe to the connecting system unit. High pressure and harsh environment condition raise the pressure on the connector; therefore, this pressure should be endured by a segment which is the carcass. Carcass holder and installation rings are components of the connectors in termination of the carcass layer. This paper assesses the role of the carcass in a sealing system of riser connectors. The sealing method is based on dividing the termination of risers into two devices; inner liner that is the mechanical restraint on the polymer barrier, and the seal system that is applied to seal the fluid of riser. This seal system includes many ring joint gaskets separated by metallic rings, and they should be placed on the carcass.

Planar Lens Antenna for High Data Rate Applications

A low-profile lens antenna formed by 2 metallic rings with strips short-circuiting both rings is presented. The theory of characteristic modes is used to facilitate the design, optimization, and analysis of the structure. Simulations and measurements are presented for the optimized single-layer metallic lens antenna. Measured results show a large operating bandwidth (14.7% relative -14 dB impedance bandwidth) with a maximum directivity above 13.70 dBi and a return loss better than 14 dB.

Bottle neck around penile neck-3 rare case reports

A variety of metallic and non-metallic rings causing constriction to the external genitalia have been described in the literature across all ages. The adult population frequently reports erotic or autoerotic goals when intentionally placing constricting devices. In adults these constricting bands are placed deliberately by the person himself to influence blood circulation and thereby obtain prolonged erection and/or sexual pleasure. A compilation of 3 rare case presentations in the casualty of JJM Medical College Davangere were collected and studied. The present case series shows that sexual perversions can present as rare surgical emergencies and need aggressive early intervention to avoid vascular compromise and its squeal.