A note on the measurement of traffic noise in congested urban situations

In this note we briefly review the various positions adopted in the past for the measurement of traffic noise levels in different situations. The use of kerbside measurements is justified for congested urban situations where the interference from pedestrians and the obstruction caused by the measuring and recording equipment can present serious problems.     

Force distortion in resonance testing of structures with electro-dynamic vibration exciters

Harmonic input force distortion which arises when systems are excited with electrodynamic exciters is shown to be predominantly second harmonic, the major source of the harmonic distortion being due to the vibration exciter characteristics. These are examined by experimentally determining the magnetic field strength properties of a typical exciter and the results show these to be a non-linear even function. This information is used with the equations of motion of the excited which are simulated on an analog computer. The computed force characteristics are shown to compare very closely with experimental results. The amount of second harmonic force distortion generated at a system resonance is analyzed by considering a simple single degree-of-freedom model. It is shown that the amount of force distortion is related to the damping of the system under test and the ratio of the exciter stiffness to the system stiffness. It is also shown that the force input to a system near a system resonance can vary considerably, even though the input current to the exciter is constant. These effects are shown to be due to the forces arising from the mass and stiffness characteristics of the exciter being used. Experimental tests on a simple system confirm the theoretical predictions.     

Syntheses in the brazilin group by way of of indeno-coumarins

The work described in this communication was carried out in 1946–1948.Reductive acetylation of brazilein afforded, in the hands of Herzig and Pollak, a substance C₁₆H₉O(OAc)₃. We have found that hydrolysis and methylation of this substance yields the known anhydro-O-trimethylbrazilin.     

A rapid radiochemical method for antimony and arsenic : Part I. Formation of stibine and arsine by flash electrolysis

The formation of stibine and arsine affords a clean, one-step, method of separating antimony and arsenic from fission products. The development of a high-current electrolytic cell for the rapid formation of these hydrides from a hydrochloric acid electrolyte, is described. A chemical yield of 45% was achieved for both antimony and arsenic in 10 sec. The effects of pH and antimony and arsenic oxidation states were also studied. In 5 N hydrochloric acid, the chemical yield is independent of the antimony oxidation state. For arsenic however, the yield of arsine is 7 times greater for As(III) than for As(V).     

The observation of energy transitions from lower valence band states in CuGaSe2

Electroreflectance data has been obtained with CuGaSe₂ single crystals which can be associated with transitions from a band of hybridized p-d states low in the valence band. The electrically p-type crystals were produced by a zone-growth technique and compensation doping was employed in order to produce resistivity values ～2Ωcm.     

Some Systems Aspects of Strategic Planning

This paper is concerned with the strategic planning process and the contribution that analysis can make to it. It develops a conceptual model of the strategic planning process based on the traditional control system model and identifies a number of basic elements of the process. Four groups of analytical tools are presented and their relevance to the planning process discussed. It is suggested that tools from the different groups may be used concurrently at different parts of the process, although the use of analytical tools in some parts of the planning process is not well established. Finally the role of the analyst in the overall planning process is discussed.     

Decision-making in Government and the Public Service: Introduction

Journal of the Operational Research Society -     

Investigation of CuInSe2 films by the method of photoacoustic spectroscopy

We investigated the photoacoustic spectra of polycrystalline thin CuInSe₂ films obtained by the method of pulsed laser evaporation onto glass substrates at 100–450°C. The spectra were taken near the fundamental optical absorption edge using a high-resolution spectrometer and microphone-type sensor. We show the relation between the photoacoustic spectrum and the structural properties of films. The interference effect observed is discussed. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 583–586, July–August, 1999.