the upper cretaceous carbonate sequence of ab-deraz formation is well exposed in the kopet- dagh basin. this formation comprises marly limestone and three chalky limestone units. chalky limestone of ab-deraz formation is mainly composed of calcareous dinoflagellate (pithonellid calcispher), cocolithofore and planktonic foraminifera. carbon and oxygen stable isotopes analysis of the third chalky...

to evaluate the effects of various concentration of carbon dioxide and salinity stress on morphophysiological characteristics of amaranthus tricolor l. an experiment was conducted in greenhouse conditions in faculity of agriculture ferdowsi university of mashhad. the experiment was split plot based on completely randomized design with three levels of co2 (380, 700, 1050 µl/l) and three concentr...

in this study a pseudo comprehensive carbon footprint model for fossil fuel power plants is presented. parameters which their effects are considered in this study include: plant type, fuel type, fuel transmission type, internal consumption of the plant, degradation, site ambient condition, transmission and distribution losses. investigating internal consumption, degradation and site ambient con...

biochar and activated carbon, as carbon-rich porous materials, have wide environmental applications. in the present research, rice husk (rh) was used for preparation of biochar at 400, 600, and 800 °c under simple pyrolysis, physically-activated carbon with water steam, chemically-activated carbon with potassium hydroxide (koh), and physiochemically-activated carbon with koh and steam. physical...

in this work, the adsorption of carbon dioxide from model flue gas on different adsorbents has been investigated. using simplified modeling, parameters such as the total mass transfer coefficient and the effective diffusivity have been determined. experiments were carried out in two sections: firstly, adsorption of pure carbon dioxide on different adsorbents was measured at pressures ranging fr...

Rangelands are the most important ecosystem for carbon sequestration. Knowledge of plant response to grazing is one of important requirements for rangeland management. Stocking rate is one of main factors in destruction of the vegetation cover in rangeland ecosystems. Livestock grazing has the potential to substantially alter carbon storage in grassland ecosystem. This study examined the effect...

bachground: acute carbon monoxide poisoning (cop) is a common problem that occurs more frequently during winter and leads to serious complications. in our poisoning referral center, the incidence and complications of acute cop has not been evaluated previously. therefore we designed a study to evaluate its significance in our center. methods & materials: 111 cases of acute cop admitted during f...

chlorination of natural water containing humic compounds, produce significant amount of disinfectant by - products. the most important of such compounds are thlvis and halo acetic acids, suspected to cause cancer in animals and human. studies showed that under usual processes of water treatment plants, thms can not be removed effectively. since chlorination is the final process of treatment, it...

soil organic carbon has been the most important soil quality measurement factors and has intense relation with soil physical, chemical and biological characteristics. organic matter and its components are important factors of soil aggregates constitution and stability and play significant role in its structure.so, this research has been done for achieving this purpose. this area is arounding sa...