A homemade CO2-laser photoacoustic spectrometer has been used for monitoring CO2 in gas samples extracted under vacuum from the wood of old spruce disc tree-rings for a ∼60 year series. The experimental results show that (1) the CO2 concentration exhibits annual trends correlated with an increase in atmospheric CO2 in a number of cases; (2) at the time when the annual CO2 trend changes from pos...

Our understanding of the effects of elevated atmospheric CO2, singly and in combination with other environmental changes,on plant-soil interactions is incomplete. Elevated CO2 effects on C4 plants, though smaller than on C3 species, are mediated mostly via decreased stomatal conductance and thus water loss. Therefore, we characterized the interactive effect of elevated CO2 and drought on soil m...

Low-carbon public passenger transport is an important part of low carbon city. The CO2 emissions of public passenger transport in Tianjin from 1995 to 2010 are estimated with IPCC CO2 counting method, which shows that the total CO2 emissions of Tianjin public passenger transport have gradually become stable at 1,425.1 thousand tons. And then the CO2 emissions of the buses, taxies, and rail tran...

In-cylinder exhaust gas recirculation (EGR) stratification, generally achieved by supplying EGR asymmetrically into intake ports on a four-valve diesel engine, is sensitive to trapped exhaust gas in the intake manifold and intake ports that is caused by the continuous supply of EGR during the valve-close periods of the intake valves. The subject of this study is to evaluate the distribution of ...

This study presents nearly continuous air-sea CO2 flux for 7 years using the eddy covariance method for nearshore water near San Diego, California, as well as identifying environmental processes that appear to control temporal variations in air-sea CO2 flux at different time scales using time series decomposition. Monthly variations in CO2 uptake are shown to be positively influenced by photosy...

Data concerning the effects of high CO2 concentrations on marine organisms are essential for both predicting future impacts of the increasing atmospheric CO2 concentration and assessing the effects of deep-sea CO2 sequestration. Here we review our recent studies evaluating the effects of elevated CO2 concentrations in seawater on the mortality and egg production of the marine planktonic copepod...

introduction: laser surgery as an alternative for conventional surgical procedure has gained special attention. using carbon dioxide (co2) laser has some benefits like less post-operative pain, swelling and infection, decrease in risk of metastasis and edema, and less bleeding providing dry sites for surgery. case report: a 12 years old boy with lingual frenum with indication for excision was r...

climate change disturbs the distribution of precipitation patterns and affects water resources. a lot of evidences imply that the increased atmospheric concentration of greenhouse gasses in turn increases the precipitation changes around the world. thus, since iran is located in an arid zone of the earth, identifying the effects of co2 concentrations on iran precipitation rate is highly importa...