scholarly journals University of Kiel Radiocarbon Measurements I

Radiocarbon ◽  
1966 ◽  
Vol 8 ◽  
pp. 235-238 ◽  
Author(s):  
H. Willkomm ◽  
H. Erlenkeuser

The C14 Laboratory at Kiel University was established in 1963. It continues measurements, which were made at the Institut für Kernphysik, Kiel, on age determination with Chlorine 36, which is produced by cosmic ray neutrons (Bagge and Willkomm, 1963, 1966). The first C14-counting apparatus was completed in 1964 and dating work started at the end of 1964 after extensive general tests of counter working conditions (Erlenkeuser, 1965). The data reported here have been obtained during the first half of 1965. During this period the dating measurements were interrupted on numerous occasions by measurements of background and the oxalic standard in order to check long-time variations of the apparatus.

2003 ◽  
Vol 21 (4) ◽  
pp. 863-867 ◽  
Author(s):  
K. Mursula ◽  
I. G. Usoskin ◽  
G. A. Kovaltsov

Abstract. It was recently suggested (Lockwood, 2001) that the cosmic ray intensity in the neutron monitor energy range is linearly related to the coronal source flux, and can be reconstructed for the last 130 years using the long-term coronal flux estimated earlier. Moreover, Lockwood (2001) reconstructed the coronal flux for the last 500 years using a similar linear relation between the flux and the concentration of cosmogenic 10 Be isotopes in polar ice. Here we show that the applied linear relations are oversimplified and lead to unphysical results on long time scales. In particular, the cosmic ray intensity reconstructed by Lockwood (2001) for the last 130 years has a steep trend which is considerably larger than the trend estimated from observations during the last 65 years. Accordingly, the reconstructed cosmic ray intensity reaches or even exceeds the local interstellar cosmic ray flux around 1900. We argue that these unphysical results obtained when using linear relations are due to the oversimplified approach which does not take into account the complex and essentially nonlinear nature of long-term cosmic ray modulation in the heliosphere. We also compare the long-term cosmic ray intensity based on a linear treatment with the reconstruction based on a recent physical model which predicts a considerably lower cosmic ray intensity around 1900.Key words. Interplanetary physics (cosmic rays; heliopause and solar wind termination) – Geomagnetism and paleomagnetism (time variations, secular and long-term)


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Rika Agustina ◽  
Rita Sunartaty ◽  
Teuku Makmur

Coconut frond ash is one of the wastes from coconut trees which has not been maximally utilized. Coconut frond ash contains MgCl2 and KCl so that it can be used as a salt substitute in the process of preserving fish. In this study coconut frond ash was used as a basic ingredient for making dried mackerel with a long time of drying to storage. The purpose of this study was to determine the effect of drying time on mackerel storage. The research design used was a Randomized Block Design (RCBD) with 2 factors studied. The first factor is the drying time consists of 3 levels, namely P1 = 3 days, P2 = 4 days, P3 = 5 days. The second factor is storage which consists of 3 levels, namely S1 = 30 days, S2 = 60 days, S3 = 90 days. Each treatment was repeated 2 times to obtain 18 experimental units to observed hedonic tests. From the results of the study it can be stated that the treatment has a very significant effect (P≥0.01) on the hedonic test which includes (color, aroma, taste and texture).


1958 ◽  
Vol 3 (25) ◽  
pp. 55-62 ◽  
Author(s):  
J. C. Barton ◽  
J. H. Stockhausen

Author(s):  
E.F. Chernikova ◽  
◽  
I.V. Fedotova ◽  
M.M. Nekrasova

Abstract: Working conditions at metallurgical enterprises are characterized by the impact of a complex of harmful production factors that do not correspond to the normalized levels, which causes the risk of developing professional and professionally conditioned pathology. Trained workers who are exposed for a long time to industrial noise that exceeds the permissible values by 10 dB or more are considered as a risk group for the development of aural (sensorineural hearing loss, SHT) and extraaural (high blood pressure, HBP) pathology. Hearing loss is an important medical and social problem, as it turns into a cognitive dissonance and a violation of verbal communication for the employee. Working conditions at one of the modern metallurgical plants were evaluated according to the data of sanitary and hygienic characteristics of working conditions. The study of the prevalence of SHT and HBP was carried out based on the materials of a medical examination and a questionnaire survey of workers (n=73, male, aged 36-75 years (57.32±0.89), with work experience of 8-58 years (34.29±1.16)). To assess the joint influence of age and seniority, an original scoring system was used, which allowed us to distinguish 3 observation groups. The severity of SHT and HBP was also assessed in points. The study showed a significant increase in the prevalence and severity of hearing loss and HBP with an increase in the duration of exposure and the age of employees. The presence of a close relationship between the analyzed pathology and working conditions is illustrated by the value of the odds ratio in groups 1-3 (ORSHT = 3.75-4.71; ORHBP = 2.0-5.0). Thus, the studied professional group of trained qualified metallurgists needs to develop health-improving measures to preserve labor longevity.


2019 ◽  
pp. 323-358
Author(s):  
P.J.E. Peebles

This chapter assesses some applications drawn from atomic and molecular structure. It deals with the structures of the lighter atoms and the simplest molecule, molecular hydrogen. The main approximation method used here is the energy variational principle, which is a powerful technique for computing the low-lying energies of a system such as an atom or molecule. The chapter then introduces the Pauli exclusion principle, which governs the symmetry of the state vector for a system of identical particles such as electrons. Two general features of the exclusion principle are worth noting. First, although the spins make only a very weak contribution to the Hamiltonians for helium, the lowest energy state with spin one is above the spin zero ground state, which is a considerable difference. Second, an electron arriving as a cosmic ray particle from a distant galaxy has to have a wave function antisymmetric with respect to the local electrons, even though the new electron has been away from us for a long time.


Changes of the energy spectrum of primary cosmic radiation can be followed through the time variations of east-west asymmetry of the μ -meson component at low latitudes. Such a study has been conducted for the first time at Ahmedabad during 1957-8. The changes of east-west asymmetry are associated with changes of the daily variation of cosmic ray in­tensity, of the daily mean neutron intensity measured at equatorial and middle latitude stations, of the index of geomagnetic disturbance and of the horizontal component of the earth’s magnetic field. The study indicates that days with high east-west asymmetry are associated with geomagnetically quiet days and a cosmic ray daily variation consistent with its being produced by an anisotropy of primary radiation outside the influence of the geomagnetic field. On such days, the daily variation produced by the anisotropy, as observed at an equatorial station, has a significant diurnal as well as a semi-diurnal component. High east-west asymmetry and associated anisotropy occur 3 to 5 days before the arrival of solar corpuscular beams which envelop the earth. Days with low east-west asymmetry occur about 3 to 4 days after the onset of cosmic ray storms associated with geomagnetic storms, usually of the SC type.


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