scholarly journals Quantification of Trace-Level Silicon Doping in Al x Ga1–xN Films Using Wavelength-Dispersive X-Ray Microanalysis

2021 ◽  
pp. 1-9
Author(s):  
Lucia Spasevski ◽  
Ben Buse ◽  
Paul R. Edwards ◽  
Daniel A. Hunter ◽  
Johannes Enslin ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Cost Effective ◽  
Silicon Doping ◽  
Contrast Imaging ◽  
Time Saving ◽  
X Ray ◽  
Combining Data ◽  
Calibration Relation ◽  
Electron Probe Microanalyser ◽  
Si Content

Abstract Wavelength-dispersive X-ray (WDX) spectroscopy was used to measure silicon atom concentrations in the range 35–100 ppm [corresponding to (3–9) × 1018 cm−3] in doped Al x Ga1–xN films using an electron probe microanalyser also equipped with a cathodoluminescence (CL) spectrometer. Doping with Si is the usual way to produce the n-type conducting layers that are critical in GaN- and Al x Ga1–xN-based devices such as LEDs and laser diodes. Previously, we have shown excellent agreement for Mg dopant concentrations in p-GaN measured by WDX with values from the more widely used technique of secondary ion mass spectrometry (SIMS). However, a discrepancy between these methods has been reported when quantifying the n-type dopant, silicon. We identify the cause of discrepancy as inherent sample contamination and propose a way to correct this using a calibration relation. This new approach, using a method combining data derived from SIMS measurements on both GaN and Al x Ga1–xN samples, provides the means to measure the Si content in these samples with account taken of variations in the ZAF corrections. This method presents a cost-effective and time-saving way to measure the Si doping and can also benefit from simultaneously measuring other signals, such as CL and electron channeling contrast imaging.

An efficient solution for the single-step synthesis of 4CaO·Al2O3·Fe2O3 powders

2009 ◽  
Vol 24 (1) ◽  
pp. 245-252 ◽  
Author(s):  
Robert Ianoş
Keyword(s):  
Combustion Synthesis ◽  
Solution Combustion Synthesis ◽  
Cost Effective ◽  
Fuel Mixture ◽  
Single Step ◽  
Combustion Reaction ◽  
Exothermic Effect ◽  
Solution Combustion ◽  
Time Saving ◽  
X Ray

Single-phase nanocrystalline 4CaO·Al2O3·Fe2O3 powders were prepared directly from the combustion reaction using a new cost-effective, time-saving, and environmentally friendly version of solution combustion synthesis. Instead of a single fuel, a fuel mixture of urea and β-alanine was used. It was shown by x-ray diffraction, energy-dispersive x-ray analysis, thermogravimetric analysis, and optical microscopy that this new version of the solution combustion synthesis allows the maximization of the exothermic effect associated with the combustion reaction. On the other hand, it was shown that the traditional version of combustion synthesis involving the use of a single fuel, such as urea or β-alanine, does not ensure the formation of Ca4Al2Fe2O10 unless subsequent thermal treatments are applied. It was suggested that the occurrence of combustion reactions cannot be regarded only in terms of adiabatic temperature, as the kinetic aspects overrule the thermodynamic ones.

scholarly journals Lung Ultrasound: new Opportunities for a Cardiologist

Kardiologiia ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 81-92
Author(s):  
A. Z. Arystan ◽  
Y. T. Khamzina ◽  
V. V. Benberin ◽  
D. V. Fettser ◽  
Y. N. Belenkov
Keyword(s):  
Lung Ultrasound ◽  
Ultrasound Examination ◽  
Cost Effective ◽  
Diagnostic Value ◽  
Ultrasound Finding ◽  
Time Saving ◽  
X Ray ◽  
Cardiac Decompensation ◽  
Chest X Ray

This review focused on ultrasound examination of lungs, a useful complement to transthoracic echocardiography (EchoCG), which is superior to chest X-ray in the diagnostic value. The lung acoustic window always remains open and allows obtaining high-quality images in most cases. For a cardiologist, the major points of the method application are determination of pleural effusion and lung congestion. This method has a number of advantages: it is time-saving; cost-effective; portable and accessible; can be used in a real-time mode; not associated with radiation; reproducible; and highly informative. The ultrasound finding of wet lungs would indicate threatening, acute cardiac decompensation long before appearance of clinical, auscultative, and radiological signs of lung congestion. Modern EchoCG should include examination of the heart and lungs as a part of a single, integrative ultrasound examination.

scholarly journals An approach to categorize chest X-ray images using sparse categorical cross entropy

2021 ◽  
Vol 24 (3) ◽  
pp. 1700
Author(s):  
Chaithanya B. N. ◽  
Swasthika Jain T. J. ◽  
A. Usha Ruby ◽  
Ayesha Parveen
Keyword(s):  
Machine Learning ◽  
Cost Effective ◽  
Cross Entropy ◽  
Ct Scans ◽  
Rt Pcr ◽  
Time Saving ◽  
X Ray ◽  
Proposed Model ◽  
Chest X Ray ◽  
Entropy Technique

The Coronavirus disease (COVID-19) pandemic is the most recent threat to global health. Reverse transcription-polymerase chain reaction (RT-PCR) testing, computed tomography (CT) scans, and chest X-ray (CXR) images are being used to identify Coronavirus, one of the most serious community viruses of the twenty-first century. Because CT scans and RT-PCR analyses are not available in most health divisions, CXR images are typically the most time-saving and cost-effective tool for physicians in making decisions. Artificial intelligence and machine learning have become increasingly popular because of recent technical advancements. The goal of this project is to combine machine learning, deep learning, and the health-care sector to create a categorization technique for detecting the Coronavirus and other respiratory disorders. The three conditions evaluated in this study were COVID-19, viral Pneumonia, and normal lungs. Using X-ray pictures, this research developed a sparse categorical cross-entropy technique for recognizing all three categories. The proposed model had a training accuracy of 91% and a training loss of 0.63, as well as a validation accuracy of 81% and a validation loss of 0.7108.

scholarly journals Fabrication of Ba Doped LaMnO3 Nanomaterials by Microwave Combustion Method

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Nguyen Viet Tuyen ◽  
Tran Thi Ha ◽  
Pham Nguyen Hai ◽  
Tran Thi Uyen ◽  
Nguyen Ngoc Dinh ◽  
...  
Keyword(s):  
Fossil Fuel ◽  
Hexagonal Phase ◽  
Cost Effective ◽  
Combustion Method ◽  
Diffraction Measurement ◽  
Time Saving ◽  
X Ray ◽  
Microwave Combustion ◽  
Doping Ratio ◽  
Microwave Combustion Method

The major energy sources that human are relying on are fossil fuel and it is exhausted day by day. Furthermore, exploition and usage of fossil fuel also bring in many negative impacts on environmental polution. Solid oxide fuel cell (SOFC) has been considerred as a potential solution for such environmental and energy problems. Seeking a facile, cost and time saving process to synthesize Ba doped LaMnO3 is very important for development of SOFC applications because it helps to reduce the cost of comercial SOFC. LaMnO3 doped with Ba is more cost effective than Sr doped LaMnO3 because less rare earth elements are used. At the same time, its conductivity is still good enough with an appropriate thermal expansion matched with those of other parts of SOFC based on ytrium stabilized zirconia (YSZ). In this paper, Ba doped LaMnO3 nanoparticles (LBMO), a promissing material for making cathode of SOFC, were prepared by microwave combustion method. This material has many advantages.  Effect of the amount fuel in the combustion reaction on the products was studied by various methods such as: X-ray diffraction measurement, scanning electron microscopy, energy dispersive X-ray spectroscopy. The results showed that each doping rate requires an appropriate amount of fuel to obtain pure and crystalline product. The obtained LBMO nanoparticles are crystallined in hexagonal phase at doping ratio of 0.2 and orthohombic phase at doping ratio of equal or larger than 0.3.

scholarly journals Compact and cost effective lab-based edge-illumination x-ray phase contrast imaging with a structured focal spot

2016 ◽  
Vol 108 (22) ◽  
pp. 224102 ◽  
Author(s):  
D. Basta ◽  
M. Endrizzi ◽  
F. A. Vittoria ◽  
A. Astolfo ◽  
A. Olivo
Keyword(s):  
Phase Contrast ◽  
Focal Spot ◽  
Cost Effective ◽  
Phase Contrast Imaging ◽  
Contrast Imaging ◽  
X Ray

The CM120 Biotwin: a high-contrast objective lens, optimum cryo-vacuum and improved EDX performance

1995 ◽  
Vol 53 ◽  
pp. 584-585
Author(s):  
Uwe Lücken ◽  
Michael Felsmann ◽  
Wim M. Busing ◽  
Frank de Jong
Keyword(s):  
Life Science ◽  
Focal Length ◽  
Objective Lens ◽  
High Contrast ◽  
Contrast Imaging ◽  
X Ray ◽  
Forming Mechanism ◽  
Similar Image ◽  
High Contrast Imaging ◽  
Low Concentrations

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.

Imaging of Al-Li-Cu alloys with a Scanning Ion Microprobe

1990 ◽  
Vol 48 (2) ◽  
pp. 314-315
Author(s):  
K.K. Soni ◽  
D.B. Williams ◽  
J.M. Chabala ◽  
R. Levi-Setti ◽  
D.E. Newbury
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Equilibrium Phase ◽  
Icosahedral Symmetry ◽  
Ion Microprobe ◽  
X Ray ◽  
Cu Alloys ◽  
Two Phases ◽  
The University ◽  
Secondary Ion

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.

Image Quality Analysis of X-ray Grating Interferometer Using Integrating-bucket Method

2020 ◽  
Vol 64 (2) ◽  
pp. 20503-1-20503-5
Author(s):  
Faiz Wali ◽  
Shenghao Wang ◽  
Ji Li ◽  
Jianheng Huang ◽  
Yaohu Lei ◽  
...  
Keyword(s):  
Image Quality ◽  
Phase Contrast ◽  
Quality Analysis ◽  
Phase Contrast Imaging ◽  
Phase Image ◽  
Contrast Imaging ◽  
High Quality ◽  
Image Quality Analysis ◽  
X Ray ◽  
Grating Interferometer

Abstract Grating-based x-ray phase-contrast imaging has the potential to enhance image quality and provide inner structure details non-destructively. In this work, using grating-based x-ray phase-contrast imaging system and employing integrating-bucket method, the quantitative expressions of signal-to-noise ratios due to photon statistics and mechanical error are analyzed in detail. Photon statistical noise and mechanical error are the main sources affecting the image noise in x-ray grating interferometry. Integrating-bucket method is a new phase extraction method translated to x-ray grating interferometry; hence, its image quality analysis would be of great importance to get high-quality phase image. The authors’ conclusions provide an alternate method to get high-quality refraction signal using grating interferometer, and hence increases applicability of grating interferometry in preclinical and clinical usage.

E-Voting Kepala Desa dan Modal Sosial

2019 ◽  
Vol 2 (6) ◽  
pp. 759
Author(s):  
Khaulah Afifah ◽  
Lala M Kolopaking ◽  
Zessy Ardinal Barlan
Keyword(s):  
Social Capital ◽  
Random Sampling ◽  
Qualitative Data ◽  
Sampling Technique ◽  
Cost Effective ◽  
Simple Random Sampling ◽  
Community Based ◽  
Time Saving ◽  
The Social ◽  
Voting System

Head of a village election with e-voting system is a new thing for community The success level of e-voting system can be reached by fulfil several principles in order to the implementation going effective and the result of the election can be accepted by all. The objectives of this research is to analyze the relation between the success level of e-voting system with social capital of the community. This research is carried out with the quantitative approach and supported by qualitative data. This research takes 60 respondents using simple random sampling technique. The results showed that the success level of e-voting has a correlation with the level of social capital of the community. Based on the field study, the social capital of the community is classified as high. The high social capital makes the implementation of e-voting successful and the success level is also high, because in the election ten years ago occurred a conflict. The community considers e-voting easier and more practical, cost effective and time-saving, and the results of e-voting are also reliable. A practical and fast of e-voting system can be a solution especially for “rural-urban” community who are busy or work outside the village.Keywords: E-voting, the success level of the system, social capital Pemilihan kepala desa dengan sistem e-voting merupakan hal yang baru bagi masyarakat. Keberhasilan penerapan sistem e-voting dilihat dari terpenuhinya beberapa prinsip agar penerapannya berlangsung efektif dan hasilnya dapat diterima oleh seluruh masyarakat. Penelitian ini bertujuan untuk menganalisis hubungan tingkat keberhasilan sistem e-voting dalam pemilihan kepala desa dengan tingkat modal sosial masyarakat. Bentuk penelitian ini adalah penelitian kuantitatif yang didukung oleh analisis data kualitatif. Penelitian ini mengambil enam puluh responden dengan teknik simple random sampling. Hasil penelitian menunjukkan bahwa tingkat keberhasilan e-voting memiliki hubungan dengan tingkat modal sosial masyarakat. Berdasarkan kajian di lapang, modal sosial masyarakat tergolong tinggi. Tingginya modal sosial tersebut membuat pelaksanaan e-voting berhasil dan tingkat keberhasilannya juga tergolong tinggi karena pada pemilihan sepuluh tahun silam sempat terjadi konflik. Masyarakat menganggap sistem evoting lebih mudah dan praktis, hemat dalam segi biaya dan waktu, serta hasil dari pemilihan juga dapat dipertanggungjawabkan. Sistem e-voting yang praktis dan cepat dapat menjadi solusi khususnya bagi masyarakat daerah “desa-kota” yang memiliki kesibukan atau pekerjaan di luar desa.Kata Kunci: E-voting, keberhasilan sistem, modal sosial. 

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