The relationship between temperature and O content relative to that for a Cretaceous belemnite of the Pee Dee formation previously reported (Epstein, Buchsbaum, Lowenstam, and Urey, 1951) has been redetermined using modified procedures for removing organic matter from shells, and is found to be t (°O = 16.5 4.38 + 0.145*, where 8 is the difference in per mil of the O to O ratio between the samp...

The relationship between temperature and O content relative to that for a Cretaceous belemnite of the Pee Dee formation previously reported (Epstein, Buchsbaum, Lowenstam, and Urey, 1951) has been redetermined using modified procedures for removing organic matter from shells, and is found to be t (°O = 16.5 4.38 + 0.145*, where 8 is the difference in per mil of the O to O ratio between the samp...

Lack of sufficient information on conservation tillage systems leads to the dominating use of conventional tillage practice in most parts of Iran. Testing other management practices may help in decision making regarding the types of tillage systems that reduce soil deterioration. A three- years field experiment was conducted to study the effects of conventional (CT), reduced (RT) and no-till (N...

since particulate matter (total suspended particles and particulate matter with median aerodynamic diameter less than 10 µm) is one of the important pollutants in the ambient air of tehran, the capital of iran, organic substances, inorganic substances and lead levels in tsp and pm10, correlation between tsp and pm10 concentrations, ratio among the two fractions and relation between tsp and pm10...

Rising temperatures enhance microbial decomposition of soil organic matter (SOM) and thereby increase the soil CO2 efflux. Elevated decomposition rates might differently affect distinct SOM pools, depending on their stability and accessibility. Soil fractions derived from density fractionation have been suggested to represent SOM pools with different turnover times and stability against microbi...

Research on nitrogen (N) mineralization from organic residues is important to understand N cycling in soils. Here we review research on factors controlling net N mineralization as well as research on laboratory and field modeling efforts, with the objective of highlighting areas with opportunities for additional research. Among the factors controlling net N mineralization are organic compositio...

the potential risk of metal accumulation in periurban agricultural areas is a matter for concern.the climate characteristics and carbonate content of calcareous agricultural mediterranean soils typical inthese areas favour metal accumulation at the surface level; however there is also a risk of potential metalmobility. our study focuses on the soil properties affecting metal mobility in these s...

application of antagonistic agents in the rhizosphere of plants is an important approach in control of soil-borne pathogens. establishment and persistence of biocontrol agents in the soil is a major concern in biological control. this study aimed to determine the effect of plant debris of oak forests on activity of pseudomonas fluorescens and trichoderma vierns against meloidogyne javanica in t...

results the batch kinetics experiments showed that nom adsorption by the adsorbents followed the pseudo-second order model. results showed that the acidic ph is optimum for adsorption of nom by smz. conclusions the findings of this study show that natural zeolite modified with sodium dodecyl sulfate, as a cationic surfactant, is a promising adsorbent for removal of nom. materials and methods in...

A specific objective of this paper was to evaluate seasonal changes in bioactive compounds level (carotenoids and polyphenols) in juice prepared from organic and non-organic tomatoes in Poland. In the examined tomato juice, the content of dry matter, vitamin C, carotenoids as well as polyphenols (by HPLC method) has been measured. The presented results indicate the impact of the growing system ...