OCEAN-An EXCEL add-in for O correction using a novel approximation.

In this publication, an alternative mathematical approach for correction is presented. It is shown comprehensively how the newly developed formulas are derived and what the differences are to the established algorithm recommended by Brand et al. Additionally, two simulations are presented, which demonstrate the performance (in terms of accuracy and precision) of the approach.

An advancement of the gravimetric isotope mixture method rendering the knowledge of the spike purity superfluous.

The gravimetric isotope mixture method is the primary method to determine absolute isotope ratios. This method, however, depends on the existence of suitable spike materials and knowledge of their purities. Determining the purity of the spikes can be tedious and labour-intensive.

Re-determination of R(C/C) for Vienna Peedee belemnite (VPDB).

Rationale: The isotope ratio for the internationally agreed but virtual zero-point of the carbon isotope-delta scale, Vienna Peedee belemnite (VPDB), plays a critical role in linking carbon isotope delta values to the SI. It is also a quantity used for various data processing procedures including 'O correction', clumped isotope analysis and conversion of carbon isotope delta values into other expressions of isotopic composition. A value for R(C/C) with small uncertainty is therefore desirable to facilitate these procedures.

Structures and Properties of -1,3,3,3-Tetrafluoro- propene (HFO-1234ze) and 2,3,3,3-Tetrafluoropropene (HFO-1234yf) Refrigerants.

The refrigerant 1,3,3,3-tetrafluoropropene (HFO-1234ze) is used as a replacement for former cooling agents that have been phased-out due to their global warming potential or ozone depleting potential. Although it is used on a large scale, only a few vibrational data and no structural data of HFO-1234ze are known. We report structure determinations based on low-temperature single-crystal X-ray diffraction data as well as gas-phase diffraction data of HFO-1234ze and HFO-1234yf (2,3,3,3-tetrafluoropropene).