نتایج جستجو برای: ozone concentration

تعداد نتایج: 399270  

2003
Azadeh Tabazadeh Eugene C. Cordero

About 90% of the ozone in the Earth’s atmosphere resides in the stratosphere, forming the ‘‘ozone layer’’ which shields life on Earth from harmful ultraviolet radiation. In the mid-1970s, it was recognized that anthropogenic chlorofluorocarbons (CFCs) could deplete the ozone layer. Observations of the ozone layer indicated that depletion was occurring due to the buildup of CFCs and Halons in th...

Hydrocarbon Processing Industries (HPIs) emit large amounts of highly reactive hydrocarbons and Nitrogen Oxides to the atmosphere. Such simultaneous emissions of ozone precursors result in rapid and high yields ozone (O3) formation downwind. The climate of the Middle East has been shown to be favorable for O3 formation in summer. There are also vast activities in processing oil and gas in this ...

2007
J. D. SKALNY G. HORVATH N. L. MASON

Mass spectrometric analysis of small negative ions (e/m < 100) produced by DC negative corona discharge in ozonised wet air both in flow and flow-stopped regimes was conducted at pressure of 30 kPa. The point-to-plain electrode system has been used. The yield of individual ions is strongly affected by trace concentrations of ozone in both regimes. Ozone concentration greater than 25 ppm is suff...

ژورنال: افق دانش 2020

Aims Myostatin and Myocyte Enhancer Factor 2C (MEF2C) are involved in muscle changes associated with bone problems. The aim of the present study was to determine the effect of three therapeutic methods of exercise, ozone, and stem cells on MEF-2C gene expression and myostatin levels of femoral muscle tissue in osteoarthritis rats. Methods & Materials This experimental study was done on 63 male...

Journal: :مجله میکروب شناسی پزشکی ایران 0
حمیدرضا توکلی hamidreza tavakoli department of nutrition, health research center, baqiyatallah university of medical sciences. tehran- iranگروه تغذیه، مرکز تحقیقات بهداشت نظامی، دانشگاه علوم پزشکی بقیه الله (عج) ، تهران رضا رنجبر reza ranjbar research center of molecular biology, baqiyatallah university of medical sciences. tehran- iranمرکز بیولوژیکی مولکولی، دانشگاه علوم پزشکی بقیه الله (عج) ، تهران حسین رستمی hossein rostami department of nutrition, health research center, baqiyatallah university of medical sciences. tehran- iranگروه تغذیه، مرکز تحقیقات بهداشت نظامی، دانشگاه علوم پزشکی بقیه الله (عج) ، تهران مرجان دلخوش marjan delkhosh department of health, faculty of nursing and midwifery, tehran university of medical sciences,, tehran- iranگروه بهداشت، دانشکده پرستاری و مامایی، دانشگاه علوم پزشکی تهران مهدی نوزآبادی mehdi noorabadi dvm in food quality controlکارشناس کنترل کیفی مواد غذایی فریده رستمی farideh rostami research center for health sciences, mazandaran university of medical sciences, mazandarn-iranمرکز تحقیقات علوم بهداشتی، دانشگاه علوم پزشکی مازندران جمشید یزدانی

background and objectives: survey on bacterial contamination is one of the most important ways for hygienic evaluation of meats at different points of processing and marketing. in the last decade application of ozone as an antiseptic agent was proposed in foods (meats, vegetables, fruits, etc.) processing. the aim of this study was to evaluate the effects of ozone gas for reduction of bacterial...

The purpose of the current study is to evaluate formaldehyde degradation ratio with various methods in a batch reactor. In this work, the ozonation, sonolysis (ultrasonic), and ozone sonolysis, sono catalytic ozonation (SCO), and nano zero-valent iron catalyst processes were investigated for removal of formaldehyde. In addition, the influence of important factors such as pH (5–9), ultrasonic po...

Journal: :caspian journal of environmental sciences 2014
al et m. masoudi

in the present study, air quality analyses for ozone (o3) were conducted in ahvaz, a city in the south of iran. the measurements were taken from 2009 through 2010 in two different locations to prepare average data in the city. relations between the air pollutant and some meteorological parameters were calculated statistically using the daily average data. the wind data (velocity, direction), re...

Journal: :Environmental Health Perspectives 2000
A S Geyh J Xue H Ozkaynak J D Spengler

The Harvard Southern California Chronic Ozone Exposure Study measured personal exposure to, and indoor and outdoor ozone concentrations of, approximately 200 elementary school children 6-12 years of age for 12 months (June 1995-May 1996). We selected two Southern California communities, Upland and several towns located in the San Bernardino mountains, because certain characteristics of those co...

2002
Sunil Ojha Ashok Kumar

This paper presents the development of two empirical ozone-forecasting models for predicting hourly ozone concentrations near Cincinnati, Ohio. This study examined the hourly ozone data collected between 1995 and 1999 at an ozone monitoring station in the Cincinnati area. Two different models, the KZ model and the NN model, were developed using data from 1995 to 1998. The KZ model was developed...

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