Procedures to prevent the occurrence of potentially dangerous situations during the operation of the Mackereth 1-metre mini or short sediment corer

During the 1950s and 1960s, F.J.H. Mackereth developed and published plans for a series of pneumatic samplers for lake sediments. Unfortunately, as the equipment was continually evolving during ensuing research, no user manuals, beyond the original publication, had been produced. Over the last few years there have been a few potentially very serious accidents with the 1-metre corer, which has prompted the authors to carry out a risk assessment. This highlighted two weaknesses in the design and its later developments. They can be corrected simply by checking for screw threads that may have been added to the exhaust port on the mini-corer, and by changing the operating procedure. An A4 nine-page user manual is now available from the authors. A small charge ( pound sterling 10 in 1998) will be made to cover handling costs and postage

Evolution in cluster cores since z~1

A large fraction of the stellar mass in galaxy clusters is thought to be contained in the diffuse low surface brightness intracluster light (ICL). Being bound to the gravitational potential of the cluster rather than any individual galaxy, the ICL contains much information about the evolution of its host cluster and the interactions between the galaxies within. However due its low surface brightness it is notoriously difficult to study. We present the first detection and measurement of the flux contained in the ICL at z~1. We find that the fraction of the total cluster light contained in the ICL may have increased by factors of 2-4 since z~1, in contrast to recent findings for the lack of mass and scale size evolution found for brightest cluster galaxies. Our results suggest that late time buildup in cluster cores may occur more through stripping than merging and we discuss the implications of our results for hierarchical simulations.Comment: To appear in the Proceedings of IAU Symposium 295 - The intriguing life of massive galaxie

The Classic: On Rest and Pain: Lecture XIV

This Classic article is a reprint of the original work by John Hilton, On Rest and Pain: Lecture XIV. An accompanying biographical sketch on John Hilton, MD, is available at DOI 10.1007/s11999-009-0927-2. The Classic Article is reprinted with courtesy from Hilton J. On The Influence of Mechanical and Physiological Rest in the Treatment of Accidents and Surgical Diseases, and the Diagnostic Value of Pain. London, England: Bell and Daldy; 1863

Taber Vibration Isolator for Vacuum and Cryogenic Applications

We present a procedure for the design and construction of a passive, multipole, mechanical high-stop vibration isolator. The isolator, consisting of a stack of metal disks connected by thin wires, attenuates frequencies in the kilohertz range, and is suited to both vacuum and cryogenic environments. We derive an approximate analytical model and compare its predictions for the frequencies of the normal modes to those of a finite element analysis. The analytical model is exact for the modes involving only motion along and rotation about the longitudinal axis, and it gives a good approximate description of the transverse modes. These results show that the high-frequency behavior of a multi-stage isolator is well characterized by the natural frequencies of a single stage. From the single-stage frequency formulae, we derive relationships among the various geometrical parameters of the isolator to guarantee equal attenuation in all degrees of freedom. We then derive expressions for the attenuation attainable with a given isolator length, and find that the most important limiting factor is the elastic limit of the spring wire material. For our application, which requires attenuations of 250 dB at 1 kHz, our model specifies a six-stage design using brass disks of approximately 2 cm in both radius and thickness, connected by 3 cm steel wires of diameters ranging from 25 to 75 microns. We describe the construction of this isolator in detail, and compare measurements of the natural frequencies of a single stage with calculations from the analytical model and the finite element package. For translations along and rotations about the longitudinal axes, all three results are in agreement to within 10% accuracy.Comment: 11 pages, 13 figures, REVTe

LYNDS 379 - a new source of bipolar molecular flow

A study has been made incorporating molecular line CO J = 2-1 and optical star counting techniques of the sharp-edged Lynds dark cloud 379. It is found to lie at a distance of 200 pc, and to have an average extinction, AB, of <2 mag. Molecular mapping has revealed the presence of a new bipolar molecular flow source coincident with a strong IRAS far infrared peak. This indicates the presence of active star formation at the edge of the cloud - possibly as a consequence of the mechanism (such as an interstellar shock) which has led to compression of the edge of L379

Trans-Atlantic Slave Trade in Luanda

The chains around the border of our memorial are to memorialize and represent the enslaved African Americans that were chained together and brought onto the boat, to places like Luanda. If you examine the image closer, one would see that we designed our memorial similarly to the Holocaust Museum in Berlin. Their memorial site really inspired the group to create something similar in terms of our aesthetic aspect.https://csuepress.columbusstate.edu/historyfrombelow/1014/thumbnail.jp