A Silicon Carbide Accelerometer for Extreme Environment Applications

A polycrystalline silicon carbide (poly-SiC) surface-micromachined capacitive accelerometer is designed, fabricated and tested. Leveraging the superior thermo-mechanical and chemical resistance properties of SiC, the device is a first step toward cost-effective implementation of a new class of extreme environment accelerometers, for example for high temperature vibration and shock measurements, even thought this initial work is at room temperature. The accelerometer described herein is designed for a range of 5000 g and a bandwidth of 18 kHz, specifications consistent with commercially available piezoelectric devices for high-level mechanical impact measurements. Test results demonstrate the sensor achieving a resolution of 350 mg/√Hz at 1kHz with a sensitivity of 12 μV/g and a bandwidth of 10 kHz at room temperature.

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4–20mA optical sensor at 300C using SiC and SOI integrated circuits

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/2380-4491.2021.hitec.000008 ◽

2021 ◽

Vol 2021 (HiTEC) ◽

pp. 000008-000012

Author(s):

Cheng-Po Chen ◽

Emad Andarawis

Keyword(s):

Silicon Carbide ◽

High Temperature ◽

Integrated Circuits ◽

Optical Sensor ◽

Room Temperature ◽

Silicon On Insulator ◽

Test Results ◽

Compression Technique ◽

Gain Compression ◽

Hybrid Circuit

Abstract GE is reporting test results from a hybrid circuit using high temperature capable resistors, capacitors, silicon carbide devices and silicon-on-insulator integrated circuits. The sensing circuit converts photodiode current to an industrial standard 4 to 20 mA output using a two wire configuration. Input currents at levels from 0pA to 30nA is converted to 4 to 20 mA using a gain compression technique and tested from room temperature to 300°C. Further, we show the circuit operating at 300°C for more than 2000 hours without failure.

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THE INFLUENCE OF INQUIRY AND DISCOVERY LEARNING METHOD AND CREATIVITY LEVEL IN WRITING SKILLS DESCRIPTION IN NAUTIC TARUNA AND TECHNIQUE IN SURABAYA SHIPPING POLYTECHNIC

SASTRANESIA Jurnal Program Studi Pendidikan Bahasa dan Sastra Indonesia ◽

10.32682/sastranesia.v8i1.1372 ◽

2020 ◽

Vol 8 (1) ◽

Author(s):

Ni Putu Dian Permata Prasetyaningrum

Keyword(s):

Quantitative Methods ◽

Writing Skills ◽

Discovery Learning ◽

Learning Method ◽

Test Results ◽

Learning Methods ◽

Is Research ◽

Investigation Methods ◽

High Level ◽

Discovery Method

Surabaya Shipping Polytechnic emphasizes on certain areas of expertise that Taruna must possess. This is the basis after graduating from shipping polytechnics, cadets must have expertise and skills. The purpose of this study was to study the effect of inquiry, discovery learning, and creativity levels on the ability to write descriptive essays on nautical and technical cadets at Surabaya Shipping Polytechnic. This type of research is research. This research uses quantitative methods using experiments. The location used in this research is Surabaya Shipping Polytechnic. The subjects in this study were the cadets of the Nautika A, Nautika B, Teknika A, and Teknika B. classes. Based on the results of the research and discussion, the following conclusions are obtained: There are those that can be solved looking for description essays in the cadets. learning discovery method. The test results show better investigation methods than the discovery of learning, There is a difference in the ability to write a description essay about cadets who have a high level of creativity with cadets who have a low level of creativity, the test results show better who have a high level of creativity, there are related with learning methods and descriptions of the ability to write essay descriptions, the test results show learning methods and creativity descriptions of the ability to write essay descriptions.

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High thermal conductivity of pure dense SiC ceramics prepared via HTPVT

Functional Materials Letters ◽

10.1142/s1793604719500322 ◽

2019 ◽

Vol 12 (03) ◽

pp. 1950032 ◽

Cited By ~ 2

Author(s):

Yuchen Deng ◽

Yaming Zhang ◽

Nanlong Zhang ◽

Qiang Zhi ◽

Bo Wang ◽

...

Keyword(s):

Thermal Conductivity ◽

Silicon Carbide ◽

Grain Size ◽

Phase Composition ◽

Room Temperature ◽

Vapor Transport ◽

Physical Vapor Transport ◽

Growth Substrate ◽

Sic Ceramics ◽

Evolution Of Microstructure

Pure dense silicon carbide (SiC) ceramics were obtained via the high-temperature physical vapor transport (HTPVT) method using graphite paper as the growth substrate. The phase composition, the evolution of microstructure, the thermal diffusivity and thermal conductivity at RT to 200∘C were investigated. The obtained samples had a relative density of higher than 98.7% and a large grain size of 1[Formula: see text]mm, the samples also had a room-temperature thermal conductivity of [Formula: see text] and with the temperature increased to 200∘C, the thermal conductivity still maintained at [Formula: see text].

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Children’s Astronomy. Development of the Shape of the Earth Concept in Polish Children between 5 and 10 Years of Age

Education Sciences ◽

10.3390/educsci11020075 ◽

2021 ◽

Vol 11 (2) ◽

pp. 75

Author(s):

Jan Amos Jelinek

Keyword(s):

Mental Model ◽

Cultural Influences ◽

Test Results ◽

The Earth ◽

Spherical Earth ◽

The Individual ◽

High Level ◽

Cognitive Problems ◽

Teaching Situations ◽

Model Approach

The Earth’s shape concept develops as consecutive cognitive problems (e.g., the location of people and trees on the spherical Earth) are gradually resolved. Establishing the order of problem solving may be important for the organisation of teaching situations. This study attempted to determine the sequence of problems to be resolved based on tasks included in the EARTH2 test. The study covered a group of 444 children between 5 and 10 years of age. It captured the order in which children solve cognitive problems on the way to constructing a science-like concept. The test results were compared with previous studies. The importance of cultural influences connected to significant differences (24%) in test results was emphasised. Attention was drawn to the problem of the consistency of the mental model approach highlighted in the literature. The analysis of the individual sets of answers provided a high level of consistency of indications referring to the same model (36%), emphasising the importance of the concept of mental models.

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Erbium/Ytterbium-Doped Waveguide Amplifier (EYDWA) for extended reach of Wavelength Division Multiplexing based free space optics system (WDM/FSO)

Journal of Optical Communications ◽

10.1515/joc-2019-0274 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Bentahar Attaouia ◽

Kandouci Malika ◽

Ghouali Samir

Keyword(s):

Wavelength Division Multiplexing ◽

Free Space ◽

Cost Effective ◽

Weather Conditions ◽

Free Space Optical ◽

Wavelength Division ◽

Space Optics ◽

Effective Implementation ◽

Transmission Distance ◽

The Cost

AbstractThis work is focused to carry out the investigation of wavelength division multiplexing (WDM) approach on free space optical (FSO) transmission systems using Erbium Ytterbium Doped Waveguide Amplifier (EYDWA) integrated as post-or pre-amplifier for extending the reach to 30 Km for the cost-effective implementation of FSO system considering weather conditions. Furthermore, the performance of proposed FSO-wavelength division multiplexing (WDM) system is also evaluated on the effect of varying the FSO range and results are reported in terms of Q factor, BER, and eye diagrams. It has been found that, under clear rain the post-amplification was performed and was able to reach transmission distance over 27 Km, whereas, the FSO distance has been limited at 19.5 Km by using pre-amplification.

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Public Officials’ Knowledge of Advances and Gaps for Implementing the Ecosystem Approach to Fisheries in Chile

Sustainability ◽

10.3390/su13052703 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2703

Author(s):

Rodrigo A. Estévez ◽

Stefan Gelcich

Keyword(s):

Decision Making ◽

Fisheries Management ◽

Cost Effective ◽

Ecosystem Approach ◽

Social Dimensions ◽

Public Officials ◽

Government Officials ◽

Effective Implementation ◽

Mandatory Requirement ◽

Support Decision Making

The United Nations calls on the international community to implement an ecosystem approach to fisheries (EAF) that considers the complex interrelationships between fisheries and marine and coastal ecosystems, including social and economic dimensions. However, countries experience significant national challenges for the application of the EAF. In this article, we used public officials’ knowledge to understand advances, gaps, and priorities for the implementation of the EAF in Chile. For this, we relied on the valuable information held by fisheries managers and government officials to support decision-making. In Chile, the EAF was established as a mandatory requirement for fisheries management in 2013. Key positive aspects include the promotion of fishers’ participation in inter-sectorial Management Committees to administrate fisheries and the regulation of bycatch and trawling on seamounts. Likewise, Scientific Committees formal roles in management allow the participation of scientists by setting catch limits for each fishery. However, important gaps were also identified. Officials highlighted serious difficulties to integrate social dimensions in fisheries management, and low effective coordination among the institutions to implement the EAF. We concluded that establishing clear protocols to systematize and generate formal instances to build upon government officials’ knowledge seems a clear and cost effective way to advance in the effective implementation of the EAF.

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Facile Green, Room-Temperature Synthesis of Gold Nanoparticles Using Combretum erythrophyllum Leaf Extract: Antibacterial and Cell Viability Studies against Normal and Cancerous Cells

Antibiotics ◽

10.3390/antibiotics10080893 ◽

2021 ◽

Vol 10 (8) ◽

pp. 893

Author(s):

Olufunto T. Fanoro ◽

Sundararajan Parani ◽

Rodney Maluleke ◽

Thabang C. Lebepe ◽

Jose R. Varghese ◽

...

Keyword(s):

Gold Nanoparticles ◽

Cell Viability ◽

Leaf Extract ◽

Room Temperature ◽

Klebsiella Oxytoca ◽

Cost Effective ◽

Average Diameter ◽

Antibacterial Activities ◽

Inhibition Concentration ◽

First Time

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer).

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Effect of Substrate Plate Heating on the Microstructure and Properties of Selective Laser Melted Al-20Si-5Fe-3Cu-1Mg Alloy

Materials ◽

10.3390/ma14020330 ◽

2021 ◽

Vol 14 (2) ◽

pp. 330

Author(s):

Pan Ma ◽

Pengcheng Ji ◽

Yandong Jia ◽

Xuerong Shi ◽

Zhishui Yu ◽

...

Keyword(s):

Room Temperature ◽

Internal Stresses ◽

Test Results ◽

Laser Melting ◽

Microstructure And Properties ◽

Uniform Microstructure ◽

Heat Treated ◽

Fine Microstructure ◽

Plate Heating ◽

Substrate Plate

The Al-20Si-5Fe-3Cu-1Mg alloy was fabricated using selective laser melting (SLM). The microstructure and properties of the as-prepared SLM, post-treated SLM, and SLM with substrate plate heating are studied. The as-prepared SLM sample shows a non-uniform microstructure with four different phases: fcc-αAl, eutectic Al-Si, Al2MgSi, and δ-Al4FeSi2. With thermal treatment, the phases become coarser and the δ-Al4FeSi2 phase transforms partially to β-Al5FeSi. The sample produced with SLM substrate plate heating shows a relatively uniform microstructure without a distinct difference between hatch overlaps and track cores. Room temperature compression test results show that an as-prepared SLM sample reaches a maximum strength (862 MPa) compared to the heat-treated (524 MPa) and substrate plate heated samples (474 MPa) due to the presence of fine microstructure and the internal stresses. The reduction in strength of the sample produced with substrate plate heating is due to the coarsening of the microstructure, but the plastic deformation shows an improvement (20%). The present observations suggest that substrate plate heating can be effectively employed not only to minimize the internal stresses (by impacting the cooling rate of the process) but can also be used to modulate the mechanical properties in a controlled fashion.

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