The reaction of CO2 hydration/dehydration controls the oxygen isotopic composition in both carbonate minerals and atmospheric CO2 through the exchange of oxygen isotopes with water. The use of O as an environmental indicator typically assumes isotopic equilibrium, namely full oxygen isotope exchange between CO2 and water. Clumped isotopes is a new isotopic tracer that is used in both CaCO3 and ...

Neutron-rich Zr and Mo isotopes were populated as fission fragments produced by the 238Usa, fd fusionfission reaction. The level schemes of these nuclei have been extended beyond the first band crossing region, which can be ascribed to the h11/2 neutron pair alignment. The spin alignment and signature splitting for the nh11/2 orbitals in term of triaxiality is addressed. The crossing frequency ...

a three-step selective photo-ionization for gd155 and gd157 isotopes by pulsed laser wasevaluated numerically. due to large thermal neutron absorption cross sections, these two isotopes innatural gadolinium are good candidates as burnable poison to control reactivity early in the fuel cycleand allow extended fuel burn up. rate equations have been used to calculate the dynamics of the isotopepop...

for more than half a century isotopes have been employed as a powerful tool in studying various aspects of water resources in a largenumber of countries. however, in developing countries like iran the application of such techniques is in its infancy. the first research iniran was carried out in 1975 to identify the source of saline groundwaters in south iran, and the first national conference o...

Analyzing variations in silicon (Si) isotopes can help elucidate the biogeochemical Si cycle and Si accumulation processes of higher plants. Importantly, the composition of Si isotopes in higher plants has yet to be studied comprehensively and our knowledge of the distribution of Si isotopes in higher plants lags behind that of Si isotopes in marine organisms, such as diatoms. In the present st...

The use of neutrons for cargo interrogation has the potential to drastically improve threat detection. Previous research has focussed on the production of (24)Na, based on the isotopes produced in pharmaceuticals and medical devices. For both the total activity and the ingestion dose we show that a variety of isotopes contribute and that (24)Na is only dominant under certain conditions. The com...

[1] The toxicity of mercury’s methylated species and its biomagnification in aquatic food chains and global dispersion by the atmosphere are the cause of worldwide health problems. Recent reports have observed natural mass-dependent fractionation in mercury isotopes, and recent theoretical work has demonstrated that isotopic separation in mercury is due primarily to nuclear field shifts (nuclea...

Tracking migratory animals has benefitted using measurements of naturally occurring stable isotopes of hydrogen (δ (2)H) in keratinous tissues such as hair and feathers to link animal origins to continental patterns or isoscapes of δ (2)H in precipitation. However, for most taxa, much less information exists on the use of stable oxygen isotope ratios (δ (18)O) despite the fact that δ (2)H and δ...

Coral skeletal boron isotopes have been established as a proxy for seawater pH, yet it remains unclear if and how this proxy is affected by seawater temperature. Specifically, it has never been directly tested whether coral bleaching caused by high water temperatures influences coral boron isotopes. Here we report the results from a controlled bleaching experiment conducted on the Caribbean cor...

Here we present methods for production of new and existing isotopes for SPECT (Single Photon Emission Computed Tomography) and PET (Positron Emission Tomography) imaging using accelerator-based systems. Such isotopes are already widely used in medical diagnostics and research, and there is constant development of new drugs and isotopes. However the main production method for Tc, is currently in...