A SURVEY OF THE C-14 CONTENT OF DISSOLVED INORGANIC CARBON IN CHINESE LAKES

We present radiocarbon (C-14) measurements of dissolved inorganic carbon (DIC) from surface waters of 11 lakes, widely distributed in China. Surface lake water DIC (FC)-C-14 values show distinct differences, and we relate these to the physical exchange character ("open" or "closed") of each lake. Open lakes studied here generally have lower DIC (FC)-C-14 values than closed lakes. We present a simple model of a lake water cycle to calculate an average residence time for each lake. Comparisons between lake DIC (FC)-C-14 and average residence time shows that the DIC (FC)-C-14 increases with the average residence time and reflects a steady-state

Cosmogenic C-14 in Antarctic and non-Antarctic meteorites and lunar samples

We were able to develop measurements of C-14 in meteorites as a useful tool for estimates of terrestrial age. Prior to this accomplishment, only a few measurements of C-14 terrestrial ages had been made. The sample sizes were larger, and there had been no systematic study of the various parameters affecting production of C-14, such as depth dependence, and the production cross sections for C-14 from spallation amounted to a few data points. Presently, C-14 ages are an accepted terrestrial age estimate in the meteorite community, whereas before this work the few data available were difficult to interpret. We have obtained terrestrial ages not only on groups of meteorites from different geographic areas but also information on unique meteorites from particularly interesting groups, such as meteorites originating from the Moon, or SNC meteorites, which many researchers believe are derived from Mars

Preliminary analysis of an extensive one year survey of trace elements and compounds in the suspended particulate matter in Cleveland, Ohio

Beginning in 1971 a cooperative program has been carried on by the City of Cleveland Division of Air Pollution Control and NASA Lewis Research Center to study the trace element and compound concentrations in the ambient suspended particulate matter in Cleveland Ohio as a function of source, monitoring location and meteorological conditions. The major objectives were to determine the ambient concentration levels at representative urban sites and to develop a technique using trace element and compound data in conjunction with meteorological conditions to identify specific pollution sources which could be developed into a practical system that could be readily utilized by an enforcement agency

Solar control of Southwest monsoon on centennial timescales

Solar forcing is proposed to be a major governing factor for the southwest monsoon (SWM) strength during the Holocene. The southeastern Arabian Sea is significantly affected by monsoon run-off and is an ideal testing ground. We analysed stable oxygen isotopic composition (δ18O) of three species of planktonic foraminifera (Globigerinoides ruber, Gs. sacculifer and Globarotalia menardii) with high time-resolution (~50 yrs) in a sediment core raised from the region, and documented past variations in SWM precipitation. High-resolution isotopic and spectral analyses show that solar forcing indeed played a major role in governing the past variations in SWM precipitation on centennial timescales

Beings in their own right? Exploring Children and young people's sibling and twin relationships in the Minority World

This paper examines the contributions that the sociological study of sibship and twinship in the Minority World can make to childhood studies. It argues that, in providing one forum within which to explore children and young people's social relationships, we can add to our understanding of children and young people's interdependence and develop a more nuanced understanding of agency. As emergent subjects, children, young people and adults are in a process of ‘becoming’. However, this does not mean that they can ‘become’ anything they choose to. The notion of negotiated interdependence (Punch 2002) is useful in helping us to grasp the contingent nature of children and young people's agency