نتایج جستجو برای: understanding the greenhouse effect and greenhouse gases

تعداد نتایج: 21292410  

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد یزد - دانشکده شیمی 1392

in this study, a simple, rapid and selective method was developed for the determination of dexamethasone. the proposed method is based on inhibitory effect of dexamethasone on the oxidation of orange-g by bromate in sulfuric acid media. the reaction was followed spectrophotometrically at 478.5 nm (?max). under optimum experimental conditions, (72.6 ?mol l-1 of orange-g, 0.76 mol l-1 of h2so4, 0...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده اقتصادو علوم اجتماعی 1390

today, the route for economic development in most countries is the same as international open competitive economy. economic institutes well known that supportive public economy belonged on the past and they may compete in the global economy. it is obvious that if they have no competitive potency or not familiar with competition technique, they may be devastated. banking system aims to collect t...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان - دانشکده علوم انسانی 1392

the present study is an attempt to investigate the potential impact of inspirational quotes on improving english abstract vocabulary recall. to achieve this goal, a multiple choice language proficiency test of 60 items including vocabulary and grammar component was administered to a sample of 63 second-semester male and female students whose age ranged between 17 to 22 and they were studying en...

this thesis attempts to investigate the effects of prelistening activities on enhancing iranian efl learners` listening comprehension. the present study investigated ways in which learners` background knowledge could be activated in order to enhance their l2 listening comprehension by limiting the number of possible text interpretations prior to listening. the experiments conducted in this study examined the effect of prior knowledge and vocabulary teaching on iranian efl learners listening comprehension. the current study has two purposes: one is to investigate the effect of background knowledge on the second language listening comprehension of iranian intermediates and the other is to determine whether second language is facilitated by the introduction of unknown vocabularies in the form of prelistening activities. to conduct the study different instruments such as listening proficiency test and four listening tests such as pre and posttests were used and various statistical processes and techniques including paired-sample t-test, and analysis of variance (anova) were used. the findings of this study supported all three hypotheses tested. differences were found between the means of preteaching vocabulary variable, the background knowledge activation variable, and mean difference between these two strategies variable. subjects scored higher when the unknown words were taught in advance. likewise, subjects scored higher when they were asked some relevant questions about the topic than on those without them. there was, in addition, a significant difference between the means of preteaching vocabulary strategy and background knowledge activation strategy. in fact, preteaching vocabulary had a better effect in enhancing the students’ listening comprehension, in comparison to background knowledge activation strategy.

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1390

this thesis attempts to investigate the effects of prelistening activities on enhancing iranian efl learners` listening comprehension. the present study investigated ways in which learners` background knowledge could be activated in order to enhance their l2 listening comprehension by limiting the number of possible text interpretations prior to listening. the experiments conducted in this stud...

2010
Fumitoshi Kaneko Hideaki Monjushiro Masaaki Nishiyama Toshio Kasai

An experimental system for detecting infrared absorption using the photoacoustic (PA) effect is described. It is aimed for use at high-school level to illustrate the difference in infrared (IR) absorption among the gases contained in the atmosphere in connection with the greenhouse effect. The experimental system can be built with readily available components and is suitable for small-group exp...

2013
P. A. Raymond M. Santini S. Sitch G. Vaglio Laurin G. R. van der Werf C. A. Williams

Introduction Conclusions References

2000
BRIAN CAIRNS BARBARA CARLSON

he aim is to better understand this complex system thereby improving computer models that can be used to predict the sensitivity of climate to changes produced by natural phenomena and human activities. One of the most difficult challenges in unraveling the climate puzzle is the role of aerosols in regulating planetary temperature. People from a range of disciplines and backgrounds are working ...

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2011
Martin Manning Andy Reisinger

Over the last 20 years, different greenhouse gases have been compared, in the context of climate change, primarily through the concept of global warming potentials (GWPs). This considers the climate forcing caused by pulse emissions and integrated over a fixed time horizon. Recent studies have shown that uncertainties in GWP values are significantly larger than previously thought and, while pas...

2000
James S. Risbey Milind Kandlikar David J. Karoly

This work develops and describes a formal probabilistic protocol via which the process of identifying lines of evidence for climate change, assessing likely causes for changes in the evidence, and combining the lines of evidence to make overall attributions of cause to greenhouse gases can be made. This open and detailed model of the detection and attribution process is designed to identify iss...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Gillian L Galford Jerry M Melillo David W Kicklighter Timothy W Cronin Carlos E P Cerri John F Mustard Carlos C Cerri

The Brazilian Amazon is one of the most rapidly developing agricultural areas in the world and represents a potentially large future source of greenhouse gases from land clearing and subsequent agricultural management. In an integrated approach, we estimate the greenhouse gas dynamics of natural ecosystems and agricultural ecosystems after clearing in the context of a future climate. We examine...

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