The oxidation on Si surface were carried out by (i) the thermal oxidation in dry and wet oxidizing gases (ii) the thermal decomposition of ethyltriethoxysilane (iii) the vacuum evaporation of SiO and quartz. The growth rates of thermal oxidation on Si surface have been studied both by interference fringe and by microbalance methods. It was found that the thermal oxidation growth curves as a function of time follow the parabolic law regardless of the kinds of oxidizing gases such as saturated water vapor etc. Crystal structure of the oxide films produced by various oxidation methods have been analysed by the electron diffraction method. According to the results of the electron diffraction, optical absorption and photoresponse measurements using step etching procedures for various oxide films, the cause of the n-type conversion due to oxidation on Si surface is discussed.

https://iopscience.iop.org/article/10.1143/JJAP.2.765/pdf

Growth and Structure of Si Oxide Films on Si Surface

Resume Ce papier concerne la diffusion de certains elements des groupes III et V dans le silicium a la pression atmospherique. Les trois elements, gallium, bore et phosphore ont ete etudies en detail. Des resultats quantitatifs sont donnes sur l'effet de protection d'une couche de silice, la temperature d'evaporation de l'impurite et la nature du gaz porteur. Les phenomenes d'oxydation et de reduction associes a la diffusion du gallium sont discutes, ainsi que l'affinite du bore pour l'oxyde de silicium.

Sur la diffusion des éléments des colonnes III et V dans le silicium

Several studies have examined how the lockdown restrictions enforced to halt the spread of COVID-19 have affected adults’ movement behaviors; however, there is limited information regarding the effects on youth. This study aimed to report on the lifestyle habits of adolescents during COVID-19 pandemic remote learning and explore associations between the participants’ bodyweight and lifestyle behaviors. We used a cross-sectional study applied to 285 students studying in the gymnasium. The response rate was 74.21%. They completed an online questionnaire regarding lifestyle, eating habits, and nutritional status (assessed by the Body Mass Index—BMI). The study was conducted in January–February 2021. The percentage of overweight and obese was higher among boys (p = 0.001). The mean sleep duration was 8.12 (SD:1.284) hours per night, and was higher in boys than in girls. The respondents met the physical activity (PA) recommendation for their age, based mainly on unorganized PA. The screen time was 4–6 h or more for the majority of the respondents. Dietary habits included a high consumption of comfort food, like cereals, sweets, soft drinks, snacks, and fried food, but a lower consumption of vegetables and fast food. The regression analyses showed that the BMI was correlated with the BMI of the parents and the number of hours spent in front of the computers in free time. The study identified behavioral and environmental factors that can be modified with effective strategies to reduce overweight and obesity among school students and to promote a healthy lifestyle.

/pdf/adolescents-lifestyle-determinants-in-relation-to-their-240ljz47.pdf

Adolescents’ Lifestyle Determinants in Relation to Their Nutritional Status during COVID-19 Pandemic Distance Learning in the North-Western Part of Romania—A Cross-Sectional Study

Objective Ongoing pediatric cohort studies offer opportunities to investigate the impact of the COVID-19 pandemic on children's health. With well-characterized data from tens of thousands of US children, the Environmental influences on Child Health Outcomes (ECHO) Program offers such an opportunity. Methods ECHO enrolled children and their caregivers from community- and clinic-based pediatric cohort studies. Extant data from each of the cohorts were pooled and harmonized. In 2019, cohorts began collecting data under a common protocol, and data collection is ongoing with a focus on early life environmental exposures and five child health domains: birth outcomes, neurodevelopment, obesity, respiratory, and positive health. In April of 2020, ECHO began collecting a questionnaire designed to assess COVID-19 infection and the pandemic's impact on families. We describe and summarize the characteristics of children who participated in the ECHO Program during the COVID-19 pandemic and novel opportunities for scientific advancement. Results This sample (n = 13,725) was diverse by child age (31% early childhood, 41% middle childhood, and 16% adolescence up to age 21), sex (49% female), race (64% White, 15% Black, 3% Asian, 2% American Indian or Alaska Native, <1% Native Hawaiian or Pacific Islander, 10% Multiple race and 2% Other race), Hispanic ethnicity (22% Hispanic), and were similarly distributed across the four United States Census regions and Puerto Rico. Conclusion ECHO data collected during the pandemic can be used to conduct solution-oriented research to inform the development of programs and policies to support child health during the pandemic and in the post-pandemic era.

/pdf/opportunities-for-understanding-the-covid-19-pandemic-and-3t3mxoaq.pdf

Opportunities for understanding the COVID-19 pandemic and child health in the United States: the Environmental influences on Child Health Outcomes (ECHO) program

Measurements of the white noise of transistors (principally, diffused‐base structures) and diodes have been made at temperatures ranging from ∼77°K to 300°K for a range of about two decades in injection level, and from 10 kc to 10 Mc Comparisons of the noise measurements with calculated levels are presented The germanium transistors show a progressively increasing deviation from the theory as the temperature is decreased, and most of the silicon transistors exhibited excess white noise at room temperature and below

Investigation of the Temperature Variation of Noise in Diode and Transistor Structures

Sleep in childhood is affected by behavioral, environmental, and parental factors. We propose that these factors were altered during the COVID-19 pandemic. This study investigates sleep habit changes during the pandemic in 528 children 4-12 years old in the US, leveraging data from the Environmental Influences on Child Health Outcomes (ECHO) Program.Data collection occurred in July 2019-March 2020 (pre-pandemic) and two pandemic periods: December 2020-April 2021 and May-August 2021. Qualitative interviews were performed in 38 participants.We found no changes in sleep duration, but a shift to later sleep midpoint during the pandemic periods. There was an increase in latency at the first pandemic collection period but no increase in the frequency of bedtime resistance, and a reduced frequency of naps during the pandemic. Qualitative interviews revealed that parents prioritized routines to maintain sleep duration but were more flexible regarding timing. Children from racial/ethnic minoritized communities slept less at night, had later sleep midpoint, and napped more frequently across all collection periods, warranting in-depth investigation to examine and address root causes.The COVID-19 pandemic significantly impacted children sleep, but parental knowledge of the importance of sleep might have played a significant protective role.During the COVID-19 pandemic, US children changed their sleep habits, going to bed and waking up later, but their sleep duration did not change. Sleep latency was longer. Parental knowledge of sleep importance might have played a protective role. Regardless of data collection periods, children from racial/ethnic minoritized communities slept less and went to bed later. This is one of the first study on this topic in the US, including prospective pre-pandemic qualitative and quantitative data on sleep habits. Our findings highlight the pandemic long-term impact on childhood sleep. Results warrants further investigations on implications for overall childhood health. 

https://www.nature.com/articles/s41390-022-02309-z.pdf

Impact of the COVID-19 pandemic on children’s sleep habits: an ECHO study

The relative merits of two double diffused transistor structures are discussed, one of which employs a localized emitter. A process for producing the localized emitter structure is described employing the masking property of against the subsequent phosphorus diffusion. The dimensions of each emitter are controlled closely by etching away this oxide mask from only those regions not protected by a specially prepared photo resist coating. Transistors have been produced which switch 30 ma with a gain of 12, in times in which the sum of the turn‐on, storage, and turn‐off time is less than 0.1 µsec. Small signal alphas of 0.97, and alpha cut‐off frequencies in the common base connection in excess of 300 mc have been achieved.

A Double Diffused Silicon High‐Frequency Switching Transistor Produced by Oxide Masking Techniques

A diffused base, diffused emitter, n-p-n silicon switching transistor has been developed for high-current applications such as switching magnetic memories. The transistor is designed to operate as a switch at the 0.75- ampere level. For a collector current of 0.75 ampere, the large signal current gain is 20 and the saturation voltage drop 4 volts. The breakdown voltages are 75 volts collector-to-base, and 6 volts emitter-to-base. The unit shows fast switching characteristics. The rise, storage, and fall times are each of the order of 0.1 µsec. It has a common emitter unity gain frequency greater than 50 Mc. The transistor employs a localized emitter produced by photoresist techniques and oxide masked diffusion. Lead attachment is accomplished by compression bonding. The silicon wafer is bonded through a molybdenum intermediary to a massive copper stud. The design theory of the device, and the variation of device characteristics with temperature are given. The applicability of this devices to RF amplifier service is also discussed.

A silicon medium-power transistor for high-current high-speed switching applications

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

J.F. Aschner

Author Tools

Chat about Author

Papers

Impact of the COVID-19 pandemic on children’s sleep habits: an ECHO study

A Double Diffused Silicon High‐Frequency Switching Transistor Produced by Oxide Masking Techniques

A silicon medium-power transistor for high-current high-speed switching applications