Hydraulic ram method for obtaining ‘undisturbed’ core samples from quaternary cave sediments. Short communication

1984 ◽  
Vol 21 (3) ◽  
pp. A119-A120
Keyword(s):  
Short Communication ◽  
Core Samples ◽  
Cave Sediments ◽  
Undisturbed Core

scholarly journals Foraminiferal stratigraphy in a marine Eemian­Weichselian sequence at Apholm, North Jutland

1984 ◽  
Vol 32 ◽  
pp. 169-180
Author(s):  
K. L. Knudsen
Keyword(s):  
Oxygen Isotope ◽  
Marine Environment ◽  
Water Depth ◽  
Late Quaternary ◽  
Core Material ◽  
Norwegian Sea ◽  
Core Samples ◽  
First Time ◽  
Eemian Interglacial ◽  
Undisturbed Core

Undisturbed core material is investigated for the first time from a marine Quaternary sequence through the Eemian of North Jutland. Core samples were examined from 86 m-190 m depth in a 202.6 m deep boring at Apholm. The marine sequence from that interval was subdivided into 4 biozones based on its foraminiferal content. Zone AP3 (190-140 m) contains boreal and boreal-lusitanian faunas indicating a water depth of at least 60-100 m. This zone is referred to the Eemian Interglacial. The Late Saatian/Eemian transition is identified at 190.2 m depth (AP4). The faunas of zone AP2 (140-113 m) record the onset of a major deterioration in climate and a considerable shallowing of the marine environment. The climate is then seen to fluctuate between arctic and boreal-arctic in zone APl (113 m to at least 86 m). This indicates the succeeding stadia! and interstadial periods. Zones AP2 and APl are referred to the Early and Middle Weichselian. The foraminiferal zones at Apholm are compared with the marine sequence at Skrerumhede. In addition, an attempt is made to relate these zones to the oxygen isotope chronology and to the Late Quaternary climatic regimes of the Norwegian Sea.

scholarly journals Soil Water Studies on Oxisols and Ultisols of Puerto Rico: IV. A Comparison of Techniques to Determine Water Retention at Various Tensions

1969 ◽  
Vol 60 (4) ◽  
pp. 513-515
Author(s):  
James M. Wolf ◽  
Matthew Drosdoff
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Field Measurements ◽  
Soil Water Storage ◽  
Water Release ◽  
Core Samples ◽  
Soil Water Tension ◽  
Comparison Of Techniques ◽  
Water Tension ◽  
Undisturbed Core

An over estimation of soil water storage would be made by employing either disturbed sample techniques at low tensions or undisturbed core samples at high tensions. To avoid this, undisturbed core samples should be used to measure water retention in the wet range (0 to 1 bar) and disturbed samples, to measure water retention in the dry range (1 to 15 bars). It is suggested that soil water release curves be developed by relating field measurements of soil water tension with results from gravimetric sampling.

Ultrastructure of primary spermatocyte in fish (Tilapia: Oreochromis niloticus): The synaptonemal complex

1986 ◽  
Vol 44 ◽  
pp. 288-289
Author(s):  
T. Guha ◽  
A. Q. Siddiqui ◽  
P. F. Prentis
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Synaptonemal Complex ◽  
Oreochromis Niloticus ◽  
Short Communication ◽  
Primary Spermatocyte ◽  
Mitotic Division ◽  
Meiotic Cell ◽  
Electron Microscope Level ◽  
Homologous Chromosomes

The Primary Spermatocytes represent a stage in spermatogenesis when the first meiotic cell division occurs. They are derived from Spermatogonium or Stem cell through mitotic division. At the zygotene phase of meiotic prophase the Synaptonemal complex appears in these cells in the space between the paired homologous chromosomes. Spermatogenesis and sperm structure in fish have been studied at the electron microscope level in a few species? However, no work has yet been reported on ultrastructure of tilapia, O. niloticus, spermatozoa and spermatogenetic process. In this short communication we are reporting the Ultrastructure of Primary Spermatocytes in tilapia, O. niloticus, and the fine structure of synaptonemal complexes seen in the spermatocyte nuclei.

SHORT COMMUNICATION

1997 ◽  
Vol 61 (3) ◽  
pp. 275-279 ◽  
Author(s):  
S. MONNO ◽  
Y. MIZUSHIMA ◽  
N. TOYODA ◽  
T. KASHII ◽  
M. KOBAYASHI
Keyword(s):  
Short Communication

Short Communication: Synthesis of Polymer-Embedded Metal Clusters by Thermolysis of Mercaptides—Polymer Blends

Polymer News ◽  
2005 ◽  
Vol 30 (9) ◽  
pp. 296-300
Author(s):  
F. Esposito ◽  
V. Casuscelli ◽  
M. V. Volpe ◽  
G. Carotenuto ◽  
L. Nicolais
Keyword(s):  
Polymer Blends ◽  
Short Communication ◽  
Metal Clusters ◽  
Communication Synthesis

Fossil diatoms from the Volga Delta Holocene sediments (Damchik region) as indicators of the paleoecological conditions of sedimentation

2019 ◽  
pp. 270-273
Author(s):  
Yelena I. Shtyrkova ◽  
Yelena I. Polyakova
Keyword(s):  
Nature Reserve ◽  
Diatom Analysis ◽  
Volga Delta ◽  
The Core ◽  
Core Samples ◽  
Holocene Sediments ◽  
Fossil Diatoms

The results of fossil diatoms investigation from the deltaic sediments are presented. Samples were obtained from the core DM-1 and two Holocene outcrops from the Damchik region of the Astrakhan Nature Reserve. In the core samples eight periods of sedimentation based on diatom analysis were identified: the sediments formed in shallow freshwater basins and deltaic channels. The samples from the outcrops were investigated in much greater detail.

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