scholarly journals AN EXPERIMENTAL STUDY OF THE PENETRATION OF CYLINDRICAL PROJECTILES INTO DRY SAND

2020 ◽  
Vol 82 (3) ◽  
pp. 283-295
Author(s):  
V.V. Balandin ◽  
Vl.Vl. Balandin ◽  
V.V. Parkhachev
Keyword(s):  
Millimeter Wave ◽  
High Speed ◽  
Radio Interferometer ◽  
Wave Radio ◽  
Ballistic Experiment ◽  
Wide Range ◽  
Measurement Results ◽  
Complete Study ◽  
Direct Experiment ◽  
Dry Sand

For the most complete study of the laws of shock interaction of solids with soil barriers, further development of experimental techniques for recording the parameters of the interaction process in direct and inverse experiments is necessary. In this work, to determine the parameters of the movement of the projectile (displacement and speed) in a direct experiment, a millimeter-wave radio interferometer is used. This method allows continuous recording of the movement of the rear end of the striker with high accuracy over a wide range of movements. Using the proposed technique, experiments were carried out to record the motion parameters of cylindrical impactors made of steel and aluminum alloy when interacting with an obstacle made of dry sand. At the same time, the movement of the rear end of the striker was also controlled using high-speed filming until the full immersion of the striker. The experiments showed that the measurement results obtained using two methods coincide within the measurement error. Based on the experiments, it can be concluded that the methodology for determining the displacement and velocity of a projectile in a ballistic experiment using a millimeter-wave radio interferometer allows continuous measurement of large displacements (100 mm or more), including when completely immersed in a target with sufficient practical goals accuracy. Based on the results of the experiments, the dependences of the movement of the projectile and its speed on time are constructed. A change in the penetration law was found with a decrease in the penetration velocity to values less than 100 m/s.

scholarly journals MEASURING DISPLACEMENT AND VELOCITY OF A STRIKER USING A RADIO-INTERFEROMETER

2019 ◽  
Vol 81 (1) ◽  
pp. 118-128
Author(s):  
V. V. Balandin ◽  
V. V. Balandin ◽  
V. V. Parkhachev
Keyword(s):  
High Speed ◽  
Radio Interferometer ◽  
Experimental Investigations ◽  
X Ray ◽  
Gas Gun ◽  
Impact Interaction ◽  
Ballistic Experiment ◽  
Wide Range ◽  
Series Of Experiments ◽  
Error Of Measurement

Investigating impact interaction of solid and deformed bodies with obstacles of various physical natures requires developing experimental methodologies of registering the parameters of the interaction process. In experimental investigations of impact interaction of solids, it is common practice to measure displacement of strikers as a function of time, as well as their velocity and deceleration. To determine the displacement and velocity of a striker, a radio-interferometric methodology of registering the displacement of its rear end is proposed. In contrast with the registration methods based on high-speed filming and pulsed X-ray photography, the method using a millimeter-range radio-interferometer provides continuous high-accuracy registering of the displacement of the rear end of a striker in a wide range of displacement values. To test the effectiveness of the methodology, a series of experiments have been conducted on registering the motion of a cylindrical striker of an aluminum alloy, fired from a 20mm-dia gas gun. The displacement of the striker was also monitored using high-speed filming. The results of measuring using the two methodologies differ within the limits of the error of measurement. Based on the results of the above experiments, it has been concluded that the methodology of determining the displacement and velocity of strikers in a ballistic experiment using a mm-range radio-interferometer makes it possible to measure practically continuously large displacements (100 mm and larger) to a safe accuracy. The present methodology can be used for measuring the displacement and velocity of the rear end of a striker interacting with obstacles of various physical natures (metals, ceramics, soils, concretes, etc.).

scholarly journals High-Speed Wide-Range True-Single-Phase-Clock CMOS Dual Modulus Prescaler

Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 725
Author(s):  
Xiaoran Li ◽  
Jian Gao ◽  
Zhiming Chen ◽  
Xinghua Wang
Keyword(s):  
Low Power ◽  
High Speed ◽  
Single Phase ◽  
Logic Gates ◽  
Cmos Technology ◽  
Propagation Delay ◽  
Operating Frequency ◽  
Wide Range ◽  
Measurement Results ◽  
Phase Clock

This manuscript presents two novel low-power high-speed true-single-phase-clock (TSPC) prescalers with division ratios of 2/3 and 4/5, respectively, in a standard 90-nm CMOS technology. The logic gates incorporated between the D-flip-flops (DFFs) of a conventional 2/3 prescaler are modified to reduce the propagation delay and hence increase the maximum operating frequency. The measurement results show that the proposed divide-by-2/3 and divide-by-4/5 prescalers can operate up to 17 GHz and 15.3 GHz, respectively, which increase by 5.4 GHz and 4.3 GHz compared with conventional TSPC prescalers. The power of the proposed divide-by-2/3 prescaler is 0.67 mW and 0.92 mW, and 0.87 mW and 1.06 mW for the proposed divide-by-4/5 prescaler. The chip occupies an area of 20 × 35 μm2 and 20 × 50 μm2 for the proposed divide-by-2/3 and divide-by-4/5 prescalers.

scholarly journals INVESTIGATION OF A MILLIMETER-WAVE RADIO LINK CHARACTERISTICS OF IEEE 802.11AD STANDARD IN URBAN AREAS

2021 ◽  
pp. 5-11
Author(s):  
Serhii Kravchuk ◽  
Liana Afanasieva ◽  
Irina Kravchuk
Keyword(s):  
Millimeter Wave ◽  
Urban Areas ◽  
High Speed ◽  
Experimental Testing ◽  
Wave Spectrum ◽  
Weather Conditions ◽  
Radio Link ◽  
5G Networks ◽  
Wave Radio ◽  
Ieee 802.11Ad

Background. The explosive growth in the use of mobile broadband is significantly increasing the bandwidth requirements. Millimeter-wave spectrum is necessary for 5G networks to achieve data transfer rates of the order of Gb/s, in particular, for the provision of 3D video services, and the use radio modules for millimeter-wave frequencies as picocells in the streets will expand the capabilities of existing cellular networks and provide an increase in bandwidth. Therefore, the study of the characteristics of this spectrum is an urgent task today. Objective. The purpose of the paper is to present the results of studying the characteristics of a millimeter-wave radio link to ensure high-speed user access to IP data transmission networks and the possibility of using the IEEE 802.11ad standard in open areas. Methods. Structural and functional methods of constructing a millimeter-wave wireless network in urban areas based on IEEE 802.11ad standard hardware are investigated. Results. The studies were carried out using a test bench with a point-to-point topology deployed in an urban environment (Kiev) with the line of sight without significant obstacles. The studies tested the possibility of using for millimeter-wave hardware technologies of the IEEE 802.11ad standard, which is used indoors, for applications in urban areas. The use of a narrow beam antenna based on an antenna array allows adaptive control of the radiation pattern to bypass small obstacles blocking direct transmission, which allows reducing interference and receive/transmit a signal. Conclusions. Experimental testing of the hardware capabilities of the IEEE 802.11ad standard has been carried out. Scenarios for constructing a millimeter-wave radio link under various weather conditions have been worked out. Keywords: millimeter-wave; bandwidth; IEEE 802.11ad standard; 5G networks

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Assessment of Commercial Off-the-Shelf Tissue Adhesives for Sealing Military-Relevant Corneal Perforation Injuries

2021 ◽  
Author(s):  
Eric J Snider ◽  
Lauren E Cornell ◽  
Brandon M Gross ◽  
David O Zamora ◽  
Emily N Boice
Keyword(s):  
Intraocular Pressure ◽  
High Speed ◽  
Anterior Segment ◽  
Ocular Tissue ◽  
Corneal Tissue ◽  
Corneal Perforation ◽  
Tissue Adhesives ◽  
Open Globe ◽  
Wide Range ◽  
Commercial Off The Shelf

ABSTRACT Introduction Open-globe ocular injuries have increased in frequency in recent combat operations due to increased use of explosive weaponry. Unfortunately, open-globe injuries have one of the worst visual outcomes for the injured warfighter, often resulting in permanent loss of vision. To improve visual recovery, injuries need to be stabilized quickly following trauma, in order to restore intraocular pressure and create a watertight seal. Here, we assess four off-the-shelf (OTS), commercially available tissue adhesives for their ability to seal military-relevant corneal perforation injuries (CPIs). Materials and Methods Adhesives were assessed using an anterior segment inflation platform and a previously developed high-speed benchtop corneal puncture model, to create injuries in porcine eyes. After injury, adhesives were applied and injury stabilization was assessed by measuring outflow rate, ocular compliance, and burst pressure, followed by histological analysis. Results Tegaderm dressings and Dermabond skin adhesive most successfully sealed injuries in preliminary testing. Across a range of injury sizes and shapes, Tegaderm performed well in smaller injury sizes, less than 2 mm in diameter, but inadequately sealed large or complex injuries. Dermabond created a watertight seal capable of maintaining ocular tissue at physiological intraocular pressure for almost all injury shapes and sizes. However, application of the adhesive was inconsistent. Histologically, after removal of the Dermabond skin adhesive, the corneal epithelium was removed and oftentimes the epithelium surface penetrated into the wound and was adhered to inner stromal tissue. Conclusions Dermabond can stabilize a wide range of CPIs; however, application is variable, which may adversely impact the corneal tissue. Without addressing these limitations, no OTS adhesive tested herein can be directly translated to CPIs. This highlights the need for development of a biomaterial product to stabilize these injuries without causing ocular damage upon removal, thus improving the poor vision prognosis for the injured warfighter.

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