scholarly journals The Principle of Formation of Metal-dielectric Micro-sized Metastructures

2020 ◽  
Vol 7 (4) ◽  
pp. 97-101
Author(s):  
A. A. Adzhibekov ◽  
◽  
A. A. Zhukov ◽  
O. A. Alekseev ◽  
◽  
...  
Keyword(s):  
Electromagnetic Radiation ◽  
High Frequency ◽  
Radiation Source ◽  
Power Level ◽  
Electromagnetic Signal ◽  
Dielectric Layers ◽  
Numerical Assessment ◽  
Deposited Metal ◽  
Alignment Marks

The principle of formation of layered metal-dielectric micro-sized metastructures, which are dielectric layers with deposited metal patterns, is proposed. The principle consists in the production of individual layers by photolithographic methods, followed by their assembly and alignment on a special installation using a source of high-frequency electromagnetic radiation with an antisymmetric field. The criterion for the accuracy of the alignment of layers is the power level of the received high-frequency electromagnetic signal at the output of the receiver, which fixes the field of the radiation source, scattered by the metal alignment marks applied to each matched layer. When applying the proposed principle, it is possible to combine optically opaque metaldielectric layers of metastructures, without the use of pins. A numerical assessment of the quality of layer alignment showed that the error of layer alignment when using a centimeter wavelength range for field sensing is no more than 3–4 µm.

Research on electromagnetic visualization method

2020 ◽  
Vol 11 (05) ◽  
pp. 2050037
Author(s):  
Fan Yang ◽  
Zhenghong Dong
Keyword(s):  
Electromagnetic Radiation ◽  
Radiation Source ◽  
Linear Interpolation ◽  
Tracking Algorithm ◽  
The Other ◽  
Visualization Method ◽  
Low Efficiency

It is significantly important to have the knowledge of electromagnet situation of battlefield, because it contains a lot of useful information to understand the situation of the whole battlefield. Electromagnet situation visualization would be very useful to help people to understand the situation, and handle battlefield situation, such as the size and quality of the electromagnetic radiation source, target objects, and operational purposes by the two parties engaged in combat scale. This paper proposes two electromagnet situation visualization methods, one is an isoline tracking algorithm based on floating rectangle and the other is an isoline filling algorithm based on linear interpolation, which also solves the problem of low accuracy and low efficiency. This paper also implements and displays the visualization results using different ways of demonstration modules, which show that the visualization results are more intuitive.

Simulation of vibration piercing of pipe blank at press

2020 ◽  
Vol 76 (11) ◽  
pp. 1128-1138
Author(s):  
S. R. Rakhmanov
Keyword(s):  
High Frequency ◽  
Deformation Zone ◽  
Pipe Blank ◽  
Equipment Operation ◽  
Metal Deformation ◽  
Technological Tool ◽  
High Frequency Vibrations ◽  
Pipe Blanks ◽  
Wave Phenomena

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.

Dynamics of the processes in metal machining

1998 ◽  
Vol 2 ◽  
pp. 115-122
Author(s):  
Donatas Švitra ◽  
Jolanta Janutėnienė
Keyword(s):  
High Frequency ◽  
Machine Tools ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Low Frequency ◽  
Metal Cutting Machine ◽  
Cutting Machine ◽  
Metal Machining

In the practice of processing of metals by cutting it is necessary to overcome the vibration of the cutting tool, the processed detail and units of the machine tool. These vibrations in many cases are an obstacle to increase the productivity and quality of treatment of details on metal-cutting machine tools. Vibration at cutting of metals is a very diverse phenomenon due to both it’s nature and the form of oscillatory motion. The most general classification of vibrations at cutting is a division them into forced vibration and autovibrations. The most difficult to remove and poorly investigated are the autovibrations, i.e. vibrations arising at the absence of external periodic forces. The autovibrations, stipulated by the process of cutting on metalcutting machine are of two types: the low-frequency autovibrations and high-frequency autovibrations. When the low-frequency autovibration there appear, the cutting process ought to be terminated and the cause of the vibrations eliminated. Otherwise, there is a danger of a break of both machine and tool. In the case of high-frequency vibration the machine operates apparently quiently, but the processed surface feature small-sized roughness. The frequency of autovibrations can reach 5000 Hz and more.

Optimizing Gas-Assisted FIB Processes: The Importance of Oft-Ignored Secondary Parameters

2004 ◽  
Author(s):  
C. Rue ◽  
S. Herschbein ◽  
C. Scrudato ◽  
L. Fischer ◽  
A. Shore
Keyword(s):  
Focused Ion Beam ◽  
Vacuum Chamber ◽  
Ion Beam ◽  
Memory Capacity ◽  
Metal Films ◽  
Deposited Metal ◽  
Influence Process ◽  
Focused Beams ◽  
Gas Pressures

Abstract The efficiency of Gas-Assisted Etching (GAE) and depositions performed using the Focused Ion Beam (FIB) technique is subject to numerous factors. Besides the wellknown primary parameters recommended by the FIB manufacturer (pixel spacing, dwell time, and gas pressures), certain secondary factors can also have a pronounced effect on the quality of these gas-assisted FIB operations. The position of the gas delivery nozzle during XeF2 mills on silicon is examined and was found to affect both the milling speed and the texture on the floor of the FIB trench. Limitations arising from the memory capacity of the FIB computer can also influence process times and trench quality. Exposing the FIB vacuum chamber to TMCTS during SiO2 depositions is found to temporarily impede the performance of subsequent tungsten depositions, especially following heavy or prolonged TMCTS exposure. A delay period may be required to achieve optimal tungsten depositions following TMCTS use. Finally, the focusing conditions of the ion beam are found to have a significant impact on the resistance of FIB-deposited metal films. This effect is attributed to partial milling of the deposition film due to the intense current density of the collimated ion beam. The resistances of metal depositions performed with intentionally defocused ion beams were found to be lower than those performed with focused beams.

Analisis Soal Matematika Tipe Higher Order Thinking Skills (HOTS) Tingkat SMP

2020 ◽  
Vol 2 (2) ◽  
pp. 112-129
Author(s):  
Lelly Oktafiana ◽  
Iis Holisin ◽  
Himmatul Mursyidah
Keyword(s):  
Power Level ◽  
Thinking Skills ◽  
Higher Order Thinking Skills ◽  
National Examination ◽  
Class Viii ◽  
Valid Test ◽  
Grade Material ◽  
Data Collection Technique ◽  
High Level

This study aims to describe the quality of the 2018 Mathematics National Examination (UN) in the HOTS types at the junior high level in terms of the level of validity, reliability, problem differentiation power, level of difficulty and distractor. This type of research is a descriptive study. The research was conducted at SMP Muhammadiyah 4 Surabaya and SMP Negeri 13 Surabaya for students in class VIII. The data collection technique used is a test. The test was taken from the 2018 math UN questions in odd semester VIII grade material including HOTS type. The number of UN mathematics questions in 2018 in the odd semester VIII class material consisted of 12 questions with 25% including LOTS types and 75% including HOTS types. The results showed: (1) 100% valid test questions, (2) high question reliability, (3) good problem differentiation power, (4) the difficuly level of the question 77,77% categorized as moderate and 2 question 22,23% are categorized as difficult, (5) there are 2 questions with one of the answer options do not work.

Systematic literature review of clinical outcomes in adults with metastatic or advanced synovial sarcoma

2020 ◽  
Vol 16 (35) ◽  
pp. 2997-3013
Author(s):  
Kentaro Kogushi ◽  
Michael LoPresti ◽  
Shunya Ikeda
Keyword(s):  
Synovial Sarcoma ◽  
High Frequency ◽  
Clinical Evidence ◽  
Systemic Treatment ◽  
Progression Free Survival ◽  
Treatment Modalities ◽  
Free Survival ◽  
New Treatment ◽  
Poor Outcomes

Background: Synovial sarcoma (SS) is a rare, aggressive soft tissue sarcoma with a poor prognosis after metastasis. The objective of this study was to conduct a systematic review of the clinical evidence for therapeutic options for adults with metastatic or advanced SS. Materials & methods: Relevant databases were searched with predefined keywords. Results: Thirty-nine publications reported clinical data for systemic treatment and other interventions. Data on survival outcomes varied but were generally poor (progression-free survival: 1.0–7.7 months; overall survival: 6.7–29.2 months) for adults with metastatic and advanced SS. A high frequency of neutropenia with systemic treatment and low quality of life post-progression were reported. Conclusion: Reported evidence suggests poor outcomes in adults with metastatic and advanced SS and the need for the development of new treatment modalities.

scholarly journals How Good Is the STW Sensor? An Account from a Larger Shipping Company

2021 ◽  
Vol 9 (5) ◽  
pp. 465
Author(s):  
Angelos Ikonomakis ◽  
Ulrik Dam Nielsen ◽  
Klaus Kähler Holst ◽  
Jesper Dietz ◽  
Roberto Galeazzi
Keyword(s):  
High Frequency ◽  
Additional Data ◽  
Empirical Method ◽  
Influential Factor ◽  
Sensor Data ◽  
Sea State ◽  
Shipping Company ◽  
Frequency Sensor ◽  
Semi Empirical

This paper examines the statistical properties and the quality of the speed through water (STW) measurement based on data extracted from almost 200 container ships of Maersk Line’s fleet for 3 years of operation. The analysis uses high-frequency sensor data along with additional data sources derived from external providers. The interest of the study has its background in the accuracy of STW measurement as the most important parameter in the assessment of a ship’s performance analysis. The paper contains a thorough analysis of the measurements assumed to be related with the STW error, along with a descriptive decomposition of the main variables by sea region including sea state, vessel class, vessel IMO number and manufacturer of the speed-log installed in each ship. The paper suggests a semi-empirical method using a threshold to identify potential error in a ship’s STW measurement. The study revealed that the sea region is the most influential factor for the STW accuracy and that 26% of the ships of the dataset’s fleet warrant further investigation.

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