Abstract: The invention provides an artificial cultch for mollusca formed of coal or lignite combustion by products (CCBP) such as fly ash and bottom ash with an optional binder, lime or Portland Cement The cultches are hemispherical or round-shaped and may be randomly stacked in a reef with interstitial void spaces for mollusca growth. The invention also provides a method of mass-producing these cultches.

Abstract: A writing instrument comprising a plurality of coaxial writing nibs and means for advancing and retracting the nibs relative to one another to adjust a selected nib into an operative writing position, whereby the instrument is adjustable to produce lines of different predetermined widths.

Abstract: An audio dosimeter for use by an individual for measuring exposure to sound which contains the following components:(a) an electronic microphonic sound sensor means,(b) an amplifier and weighting circuit,(c) an x-squared detector circuit,(d) a temperature compensation circuit;(e) analog to digital time converter,(f) a microcomputer which controls functions of the temperature compensator circuit and analog to digital time converter and has unique logarithmic mathematics for converting the signal from the converter into sound measurement values such as percent of dose, average and maximum decibel levels and instantaneous sound level.

Abstract: An apparatus that measures light transmitted through a fluid sample and provides a direct readout of such a measurement by electronically converting light transmitted to an electrical signal that is displayed on a readout device; the apparatus contains a power source, a light source, a photodetector, a sample holder for samples that forms a cell; the improvements used in the apparatus are as follows:(a) a color interference filter positioned between the sample and the photodetector which filters out unwanted bands of color,(b) a converter which electronically converts a current signal from the photodetector to a voltage signal,(c) a logarithmic response circuit that changes the voltage signal to a logarithmic signal proportional to the logarithm of the voltage signal; and(d) a digital voltmeter that converts the logarithm signal to a signal that is displayed on a readout device.

Abstract: An improved dosimeter designed for individual use that has a filter for collecting particles or vapors present in an air stream being pumped through the dosimeter, a variable drive pump that draws the air stream through the filter, an electric motor coupled to the variable drive pump, an electric power source for the motor, an air reservoir connected to the pump, an orifice position in a tube attached to the air reservoir which creates a pressure drop in the air stream, a differential pressure switch positioned before the orifice that is activated by a change in air pressure and creates a low voltage electrical input signal; an integrator circuit that uses the low voltage input signal of the pressure switch and integrates this signal, an amplifier circuit which amplifies the signal from the integrator circuit and feeds the signal to the electric motor thereby controlling the speed of the motor driving the pump in relationship to the signal generated by the pressure switch to maintain the air stream at a const

Abstract: An improved dosimeter for monitoring working areas in which air, preferably in a relatively large volume, is pumped through the dosimeter at a controlled constant flow and any particles or vapors in the air are collected on a filter, the improvement is the use ofA variable drive pump connected to the filter and driven by an electric motor and controlled by a feed back circuit of an integrator and an amplifier and the pump maintains a constant flow of air through the dosimeter;In the operation of the dosimeter the integrator receives a signal from a pressure switch that detects changes in the flow of the air stream through the dosimeter by a change in a pressure drop of the air which is being pumped through an orifice;The dosimeter is placed in a work area and at the termination of a period of time, such as a work day, the filter is removed and the contents collected are analyzed by conventional techniques such as gas chromatography to determine a level of exposure of individuals working in that area.