Individual weight, development time and yield of different stages of Tropodiaptomus incognitus (Crustacea: Copepoda). [Translation from: Cahiers ORSTOM, Serie Hydrobiologie 4(1) 63-70, 1970. ]

Observations of individual weight, duration of development and production of different stages of Tropodiaptomus incognitus are presented. The study is based on data gathered from Lake Chad in 1968

Optical properties of Southern Hemisphere aerosols: Report of the joint CSIRO/NASA study

This study was made in support of the LAWS and GLOBE programs, which aim to design a suitable Doppler lidar system for measuring global winds from a satellite. Observations were taken from 5 deg S to 45 deg S along and off the E and SE Australian coast, thus obtaining representative samples over a large latitude range. Observations were made between 0 and 6 km altitude of aerosol physical and chemical properties in situ from the CSIRO F-27 aircraft; of lidar backscatter coefficients at 10.6 micron wavelength from the F-27 aircraft; of lidar backscatter profiles at 0.694 microns at Sale, SE Australia; and of lidar backscatter profiles at 0.532 microns at Cowley Beach, NE Australia. Both calculations and observations in the free troposphere gave a backscatter coefficient of 1-2 x 10 to the -11/m/sr at 10.6 microns, although the accuracies of the instruments were marginal at this level. Equivalent figures were 2-8 x 10 to the -9/m/sr (aerosol) and 9 x 10 to the -9 to 2 x 10 to the -8/m/sr (lidar) at 0.694 microns wavelength at Sale; and 3.7 x 10 to the -9/m/sr (aerosol) and 10 to the -8 to 10 to the -7/m/sr (lidar) at 0.532 microns wavelength at Cowley Beach. The measured backscatter coefficients at 0.694 and 0.532 microns were consistently higher than the values calculated from aerosol size distributions by factors of typically 2 to 10

Haze in the Klang Valley of Malaysia

Continuous measurements of dry aerosol light scattering (Bsp) were made at two sites in the Klang Valley of Malaysia between December 1998 and December 2000. In addition 24-h PM2.5 samples were collected on a one-day-in-six cycle and the chemical composition of the aerosol was determined. Periods of excessive haze were defined as 24-h average Bsp values greater than 150 Mm-1 and these occurred on a number of occasions, between May and September 1999, during May 2000, and between July and September 2000. The evidence for smoke being a significant contributor to aerosol during periods of excessive haze is discussed and includes features of the aerosol chemistry, the diurnal cycle of Bsp, and the coincidence of forest fires on Sumatra during the southwest (SW) monsoon period, as well as transport modelling for one week of the southwest Monsoon of 2000. The study highlights that whilst transboundary smoke is a major contributor to poor visibility in the Klang Valley, smoke from fires on Peninsular Malaysia is also a contributor, and at all times, the domestic source of secondary particle production is present

A study on elasto-plastic impact friction

A purpose-built pendulum machine was used to study the oblique impact and the behaviour of the surface layers of a normalized low alloy steel subjected to the impact of hard [alpha]-alumina balls. The effect of relative tangential velocity on impulses, restitution coefficient and impact energy loss, was analysed. The morphology of the impact indentations was characterized and related to the impulses obtained. There was lip formation in the target material with ejection of a small fragile oxidized chip, at a certain critical sliding speed. The impact duration and the impulse ratio have maximum values. These values seem to be related to the critical angle of attack, common in abrasive and erosive ductile processes. The experimental results were compared with some impact models and theories.http://www.sciencedirect.com/science/article/B6V5B-3WRC3G0-4/1/41e4c5269f22928dae6bfa3fb640fd0

Beam profile measurements at 40 MHz in the PS to SPS transfer channel

Bunch to bunch beam profile measurements provide a valuable tool to control the injection lines to the SPS. A fast profile monitor based on a 2.5 µm Mylar coated with Aluminium Optical Transition Radiation (OTR) radiator, has been developed, installed and tested in the transfer line between the PS and SPS. The OTR beam image is focused onto a fast Linear Multianode Photo Multiplier Tube and the associated electronics sample and store profiles every 25 ns. The paper describes the detector design, the electronic processing, and presents the results of different measurements made with bunches of 109-1011 protons at 26 GeV, and bunches of 106 Pb82 ions at 5.11 GeV/u

Control and monitoring of the SPS proton and ion extractions

For the fixed target program of the SPS, protons and ions are accelerated and extracted towards seven target stations in the NORTH and WEST experimental areas. These extractions range from 106 Lead ions to 1013 protons with durations of 5 or 2.5 s and are controlled by a closed loop system. The intensity monitoring for this system is done with fast screens observed with Photo Multipliers and Secondary Emission Monitors sampled every 100 µs. Along the beam lines, the intensities of the extracted beams are monitored with fast screens at 100 ns intervals. Time and frequency domain information are extracted for diagnosis from the acquired data. A slower observation system, with a 1 ms sampling interval, is also available for assessing the evolution of the centre of charge, the intensity and the losses along the beam lines during an extraction

Screens versus SEM grids for single pass measurements in SPS, LEP and LHC

When the transfer channels of the SPS and LEP were designed in the 70¹s and early 80¹s, it was foreseen to use screens to observe qualitatively the beam positions and shapes and Secondary Emission Grids and Split Foils to perform precision profile and position measurements. Foils covering the whole aperture were installed for measuring the beam intensities. The original screens were 1 mm thick, which blows up the low energy beams and limits the number of screens which can be used simultaneously. With the use of different screen materials, image acquisition hardware and processing software, the TV screens are now competing with the SEM Grids for precision measurements. The screens are simpler in construction, have a large spatial resolution, typically 105 points, and are more sensitive. The use of fast luminescent material and thin Optical Transition Radiation screens are extending the screen monitor field to bunch length and time structure measurements. Limitations of Secondary Emission Monitors and results obtained with screens with hadrons and leptons are reported. Future applications are considered