bluuebunny/crossref_metadata_2025 huggingface dataset:
On-Line Liquid and Gas Density Measurement-Advantages of Frequency Domain Transducers
Authors: Agar J.
Published: November 2015

This paper discusses the advantages of frequency modulated transmission of information in plants, and how this philosophy is adapted in practice in the form of two instruments for on-line measurement of liquid and gas densities.

The importance of measuring density is well appreciated for on-line blending and various forms of quality control applications, but special attention is drawn to its necessity in gas flow metering.
The Automatic-Control System as a Communication Channel
Authors: Bell D. A.
Published: November 2015

The science of communication was pursued in mathematical form much earlier than the science of control, since the former can be traced back at least to the mid nineteenth century when Kelvin solved the differential equation of the propagation of an electric signal along a cable of negligible inductance; and in the first quarter of the nineteenth century a number of well-known applied mathematicians (for example, Heaviside, Carson, Sobel, Nyquist) were associated with telecommunications. Moreover, Shannon's elaboration and consolidation of the mathematical theory of communication came before the major developments in automatic control. It is therefore profitable to examine whether any of the theorems or techniques which have been developed in connection with telecommunications can be applied to problems in automatic control.
As Seen by a User
Authors: McGill R. J.
Published: November 2015

This paper summarises the relevant facts and problems as they appear to a user and does not claim to present new material.

The intention is simply to set the scene for more stimulating subjects which follow.
Designing Mechanised Aids to the Management of Production
Authors: Nutting David
Published: November 2015

The control engineer of today is seemingly a man of many rare virtues and attributes: he combines practical realism with ingenuity; he is a man of vision and of high intellectual calibre. Given an understanding of his company's objectives and restraints, he can engineer a productive unit in conjunction with process and other specialists, to meet its target, on specification, on quantity, with safety and with the automatic generation and preparation of the necessary production statistics.

In recent years several universities have followed the lead set by Cambridge with postgraduate and later, as at City University, first degree courses in control engineering. From the start BP has been a consistent supporter of these courses and several of the postgraduate trainees and ex-university apprentices, having read this relatively new subject, are in Control Engineering Branch. There they meet the intellectual challenge of applying the full power of modern technology on a broad front of the company's operations in production, refining and distributing.

The control engineer's dream is not of automatons nor of refineries without human beings: he is concerned with giving refinery management a reliable mechanism through which to attain its objectives as efficiently as possible.
Principles, Practice and Problems
Authors: McGill R. J.
Published: November 2015

Moisture content is one of the most important papermaking variables. Close control in the process is essential. Accurate knowledge of its absolute value, separated from that of solids, is highly desirable, for process and profit optimisation.

A wide variety of measuring equipment and control methods is in use and several installations are described.

Outstanding problems include the need to improve measurement reproducibility and independence from the effects of other variables, simplification of calibration and control, wet end measurement and cross-direction profile control.

The ultimate aim should be an overall system for moisture and substance, incorporating distribution of measurement and control points throughout the process.
Fluid Dynamic Problems Awaiting Solution
Authors: Engel F. V. A.
Published: November 2015

It is recommended that fluid dynamic problems related to specific phenomena of pulsating flow should be dealt with on the basis of non-dimensional parameters. Part I presents a survey of essential parameters. Recent research on self-induced pulsations and forced sinusoidal pulsating flow is reviewed. Investigation of the experimental results of these studies reveal crucial parameters, their correct choice and design. These few parameters are recommended as basic tools of analysis of more complex problems which are encountered in fluid flow measurement.

In Part II peculiarities in flow and the behaviour of metering devices such as orifices, Venturis, or variable area flow meters are scrutinized. Some of these features, even under steady flow conditions, are not yet well understood. They should be fully explored in future studies as they may explain residual errors under pulsating flow conditions. Suggestions for future research are mainly concerned with flow conditions in the pipe line upstream of the metering device.
Process Gas Analysis in the Iron and Steel Industry by Mass Spectrometry
Authors: Schuy Klaus D. , Reinhold Bodo
Published: November 2015

Advantages of applying mass spectrometry to the analysis of process gases in the iron and steel industry are:

Only one instrument is required for the analysis of all process gas components of interest; These components are simultaneously and quantitatively analysed; The analysis speed is the same for all components, and is extremely high; The signal produced by any one gas component is linearly proportional to the concentration of that component; For complete analyses, the analyser requires very small amounts of sample and calibration gas; The gas analyser can also be used to check the calibration gases for impurities and to control their concentration ratios.

After a brief discussion of mass spectrometer principles and instrumentation, some typical applications of mass spectrometer-based gas analysis systems as applied to the iron and steel industry are elucidated. The incorporation of a digital mini-computer results in an integrated, autonomous process gas analysis system, containing sampling and handling facilities, gas analyser, calibration setup and TTY data printout.
Isotope Gauges: An Analysis of Some Errors in Hot Metal Thickness Measurement
Authors: Macedo F. X. , Seredynski F.
Published: November 2015

Isotope gauges are particularly suitable as thickness measuring instruments for hot metal above 5 cm. thick and their application for this purpose is continuing to increase. The paper discusses some of the factors affecting the accuracy of these gauges and, in particular attempts a theoretical evaluation of the errors due to steel composition, temperature distribution and statistical variation. These errors are evaluated for three carbon steels. Errors in thickness measurement due to the different compositions of these steels are evaluated for the two isotope sources most commonly used for gauging purposes namely, Americium 241 and Caesium 137. These isotope sources are representative of those used for the entire practical range of thickness measurement. The paper considers the effect of temperature distribution across the depth of metal on the mass attenuating the γ-rays and the thickness measurements so evaluated are compared with those determined assuming a homogenous stock temperature. The principle of constant absorption is described and also some of its limitations where a wide range of measurements is required. Finally an artifice is discussed whereby some of the limitations may be overcome.
Holographic and Video Techniques Applied to Engineering Measurement
Authors: Butters J N , Leendertz J A
Published: November 2015

In a brief period, lasers have developed from curiosities of the physics laboratory to tools suited to incorporation in complex instrumentation systems. One line of progress has been through the applications of holography and holographic interferometry to engineering metrology where the potential of a precision comparator is realized without a convenient means of using it. The process, however, has formed a basis for development and the progress of holographic metrology is reviewed leading to more general concepts better described as “Coherent Optical Metrology”.

The authors' latest developments in this area are described where, by means of a coherent optical sampling technique, three dimensional data is coded onto an electronic video waveform. The method is based on speckle pattern interferometry with optical to electronic interfacing by means of a modified closed-circuit television arrangement. With this instrumentation, most of the measurement facilities of holography are retained without many of the inconveniences arising from photographic recording. The data is processed electronically and displayed or presented in a form suitable for viewing or to actuate a stage of process control.
Studies on the Control of Accommodation and Convergence
Authors: Toates F M
Published: November 2015

A control model of accommodation and convergence has been developed further, in accordance with the physiology of the eye. It is argued on control theory grounds for accommodation, and more tentatively for convergence, that effort is able to be exerted on both sides of a resting point which lies at an intermediate position between the extremes of the range. Thus convergence and active divergence, in addition to positive and negative accommodation, are examined.
Controller Design for Linear Multivariable Systems
Authors: Walker P H , Green J W
Published: November 2015

A method of designing controllers for multivariable systems is described which regards the problem from an implicit reference model point of view. The rules for the design are found to be very simple to apply and involve only proportional and integral terms if all the system state variables are available.

The method is demonstrated by means of two examples, one being a second order system with two inputs and two outputs, the other being a fourth order system also with two inputs and two outputs.
Correlation Techniques for the Identification of Non-Linear Systems
Authors: Simpson R. J. , Power H. M.
Published: November 2015

The Volterra series expansion of the response of a non-linear system is described, along with its counterpart in the frequency domain. Cross-correlation methods for identifying the kernel functions which occur in this expansion are reviewed, with particular emphasis on techniques for obtaining the linear approximant to a non-linear system. Some recent work which appears to be unrelated to the Volterra approach is also discussed.
Mass Flow Metering
Authors: Wasson R.
Published: November 2015

Mass flow measurement has many real advantages over volumetric measurement, particularly for gas flows. True and inferential methods of measuring mass flow are compared and true methods found to be significantly better. Of the different methods of measuring true mass flow, the axial flow transverse momentum method is shown to be particularly well suited to industrial application.

A short outline of the history of the Black, Sivalls and Bryson Mass Flowmeter, which uses this principle, is given and it is shown that a very considerable amount of development and industrial trials were required before the meter achieved its present position where many large users of it are very satisfied with it. The results of extensive trials with the meter and of the subsequent use of 28 meters in ICI's Petrochemicals Division are presented and it is shown that the meters have given reliable service and shown good repeatability resulting in much improved material balances. The availability of suitable calibration facilities is reviewed and an indication given of likely further developments in this field.
Humidity Effects on Fluidic Temperature Devices
Authors: Geremia John O. , Wu Chih
Published: November 2015

A fluidic temperature device, designed by and obtained from The Harry Diamond Laboratories, was tested for stability when subjected to a variation of moisture content in an air stream. The device proved highly stable over a wide range of moisture contents. Slight variations in frequency were consistent with the variation predicted by the ideal gas behaviour of an air-water vapour mixture. The device is stable enough to be calibrated with dry air and corrected to any other humidity condition by application of the thermodynamic equations governing ideal gas mixtures.
Discrete PID Controller with a Single Tuning Parameter
Authors: Roberts P. D. , Dallard K. E.
Published: November 2015

The paper describes a simple procedure for tuning discrete proportional — integral — derivative control algorithms. Two recommendations which are currently employed to select controller parameters are combined. For a given sampling frequency this leaves only the controller gain to be adjusted on each control loop. The technique has been applied to the regulation of a process represented by a single time constant and time delay which is subjected to load disturbances. Digital simulation results are given which show that acceptable regulation is obtained which is comparable to tuning all three controller parameters to minimise a specified integral performance index.
Digital Simulation of the Steady State Behaviour of Moving Bed Processes;
Authors: Voskamp J. H. , Brasz J.
Published: November 2015

A mathematical description of a complicated pellet indurating machine is presented that is simple and useful for digital computation and optimisation purposes. The arguments for some of the approximations used are given together with the resulting differential equations. A short discussion is devoted to some of the computational aspects.

The verification of the model is described briefly, and typical computational results are presented from which some process conclusions are drawn.

Although the process is specialised, the approach followed in this paper may be useful to other types of packed bed processes including sintering and drying of foods.
Some Ultimate Limits on the Measurement of Surfaces Using Stylus Techniques
Authors: Whitehouse D. J.
Published: November 2015

In recent years the use of stylus instruments has progressed from mainly engineering applications into research fields. This is mainly due to the development of highly sensitive instruments. Some results of this work are shown together with the limits of measurement encountered on the surface layer, the surface-instrument interface and the instrument itself. The extension of the technique to measure mechanical as well as geometrical features of the surface skin is shown, and finally some future developments are predicted.
Electro-Optic Inspection Equipment for Measuring the Edge-Work Quality of Glass Sheets
Authors: Gallagher P. , Clarke L. T.
Published: November 2015

Problems of breakage have been encountered in production when edge-worked glass plates have been subsequently put through a thermal toughening cycle. The equipment described in this paper was designed to inspect the edge of the glass in two orthogonal directions, to differentiate between a variety of faults and to give accept/reject information which may be fed-back to the edge-working station. The information obtained from this system was initially used in production to monitor which types of faults were causing the breakages so that greater control of these could be applied by both the monitoring equipment and the actual edge-working process.
Solution of Implicit Algebraic Equations in Continuous Systems Simulation
Authors: Gulland W. G.
Published: November 2015

This paper presents a collection of techniques which the author has found useful when simulating continuous systems on analogue and digital computers. It is concerned with the solution of implicit algebraic equations of the general form:

f(x) = 0

It outlines the advantages and disadvantages of the methods. and includes an example from the author's own experience in the chemical industry. The digital programme examples are based on CSMP 360.
Timing System for a Chemical Plant by Hydrofluidics
Authors: Belforte G. , Piombo B.
Published: November 2015

A new timing system for a water treatment chemical plant is introduced here. The purpose of this system is to permit the inlet of sodium hypochlorite for 20 min at a time interval variable from 2 to 6 h. The problem is solved by a fluidic-mechanical equipment utilising as power source the same water circulating in the plant. For this purpose suitable hydrofluidic elements have been studied, and their performances are presented. Then the timing system, designed with a mechanical spring timer and two memory hydrofluidic components, is described. The spring timer drives thin plates which operate some hydrofluidic sensors; these sensors control the two memory hydrofluidic components. The first fluidic element controls the inet valve of the hypochlorite; the second element reloads the timer at the end of the cycle
The Megalithic Yard
Authors: Thom A.
Published: November 2015

A brief account is given of the reason for our belief in the existence of the megalithic yard. The statistical background is explained.

It is shown that megalithic surveyors could attain an accuracy equal to that given by modern methods. The lecture includes a brief account of megalithic astronomy and its possible motivation.
Computer Simulation of Railway Locomotives and Trains
Authors: Ashworth E. O.
Published: November 2015

An outline of the computer simulation technique is presented, along with a description of the representation of the railway locomotive/train system. This is followed by a survey of locomotive/train simulation, based mainly on work carried out at the Railway Technical Centre, Derby. Firstly, the simulation of train movement and its application to models of the working railway is described. Secondly, the simulation of train control systems within a train simulation is dealt with. Finally, an introduction is given to the computer simulation used in locomotive and train simulators. The paper concludes with some views on the reasons for computer simulation, and mentions the problems and success of the technique.
The Distribution of Force under the Human Foot—An On-Line Measuring System
Authors: Dhanendran M. , Hutton W. C. , Paker Y.
Published: November 2015

The distribution of force under foot is an important parameter for assessing different surgical procedures on it. In order to develop a clinical tool to do this completely and accurately, a system has been developed based on resistance strain gauge load cells. These have an exposed area 15 × 15 mm square and have been assembled in square modules of 16. Eight such modules (128 load cells in all) have been brought together in a 4 × 2 arrangement to form a load sensitive area 250 × 125 mm. To condition and process the data the load cells have been connected through amplifiers, a multiplexer and an analogue to digital converter to a PDP 11/40 minicomputer. This has been programmed to give as one option a hard copy graphic representation of the actual outline of the foot with the force readings printed in a superposed matrix. Force/time curves can also be plotted for individual cells.
Low-Flow Valve Sizing and Selection
Authors: Marcadet L.
Published: November 2015

Processes calling for low flows usually require a high degree of precision which, in turn, depends on the final element of the control loop, ie, the control valve. This paper demonstrates the difficulties as well as the interest for accurate sizing of low-flow control valves and shows how a new solution solves the problem.
Commercially Available Flowmeters and Future Trends
Authors: Furness R A , Heritage J E
Published: November 2015

This article classifies flowmetering devices into 12 groups. Over 70 types are tabulated and many of the different measuring techniques are briefly reviewed. Some guidelines are given on flowmeter selection and commercial availability. Finally, new methods at the research stage are indicated and possible future trends and developments are discussed.
The Calibration of Flowmeters
Authors: Pursley W C
Published: November 2015

The paper presents an account of all the main methods in current use for the calibration of liquid and gas flowmeters both in the laboratory and in the field. Also included is a description of the traceability hierarchy for flow measurement in the United Kingdom and the paper ends with an estimation of the calibration accuracies which might be expected at various levels in the traceability hierarchy.
Signal Analysis and Intelligent Flowmeters
Authors: Higham E H , Fell R , Ajaya A
Published: November 2015

In general, the instruments used for process measurement provide an acceptable level of performance, but there are occasions when the process operators suspect the integrity of the measurement signal and feel obliged to call on the instrument staff to check the span and zero of the transmitter. Quite apart from the cost of making such a test, experience shows that many of the transmitters checked in this way, and shown to be functioning correctly, subsequently become defective. Even if it were possible to devise a remotely controlled means for checking the span and zero, it is doubtful whether it could ever become a practical proposition.

An entirely different approach is to use active sensors, such as resonant elements, in place of the traditional passive devices and to apply signal analysis techniques, which can be implemented by microprocessors. The measurement signal for these and other types of sensor can be derived from the time interval between successive zero crossings and this avoids the need for A/D conversion. Furthermore, analysis of the signal enables information regarding the status of the sensor as well as the operation of the associated process plant to be determined. This has been demonstrated by the application of these SFT to the signals generated by a turbine flowmeter.
Evolution of Communication Standards for the Process Industry
Authors: Wood G G
Published: November 2015

This paper gives a chronological introduction to the main areas of standardisation activity and developments for local area communications in the process control and automation industries.
Remote Boundary Pressure Control
Authors: Arden W J B , Cox C S
Published: November 2015

In recent years the emphasis within British Gas PLC has moved from the construction aspects of the natural gas transmission system, to one of investigating methods of optimising the operational efficiency of the existing pipline network. In particular, the developments which have taken place in the area of microprocessor technology have provided the opportunity to implement improved control strategies in areas where existing pneumatic based systems are somewhat limited in terms of performance. This paper describes a problem associated with the control of pressure, at a remote point, which can be a considerable distance downstream from the main pressure regulating station. In addition, it illustrates how a series of simulation studies have enabled the evaluation of the revised control philosophy, quickly, efficiently and at minimal cost.

This paper is based on previously published work entitled ‘Investigations into the Remote Pressure Control of Gas Transmission Pipelines’, by C S Cox, W J B Arden and I Fletcher. Presented at Int AMSE Conf ‘Modelling and Simulation’, Sorrento (Italy) Sept 29th-Oct 1st, 1986.
Challenging Areas in Flow Measurement
Authors: Kinghorn F C
Published: November 2015

Flow measurement has many applications and a wide range of techniques is used. In many industrial sectors there are particular difficulties in measuring flowrate and often special solutions are required. Some of the problems in the oil and gas, biotechnology, automobile and water supply industries are described and the shortcomings or difficulties associated with the methods currently being used are identified.

There are also numerous technical difficulties which span several industrial sectors and the topics of multi-phase flow, direct mass flow measurement, pipework configuration effects and computational fluid dynamics are covered, although it is recognised that these are only a few of a very much larger number of difficult areas.
Installation Effects on Vortex Flowmeters
Authors: Mottram R C , Rawat M S
Published: November 2015

Most types of flowmeter are affected by flow disturbances caused by nearby pipe fittings. In the case of the vortex flowmeter, users currently have to rely on manufacturers' recommendations on minimum straight pipe lengths on either side of the meter as there are no relevant standards or codes of practice and little published experimental data. The paper presents some experimental results on the effects of upstream pipe roughness, single 90† bends, and pairs of 90† offset bends on the calibration in air of a vortex meter with a rectangular section bluff body. The results show that this particular vortex meter is sensitive to the roughness of the upstream pipework and required straight pipe lengths of about 55 diameters to avoid significant calibration changes caused by upstream bends.

Installation lengths can be reduced by placing a flow straightener upstream of a meter particularly if the straightener-meter package can be calibrated as a unit. This concept has been explored using a Mitsubishi flow straightener with the vortex meter and promising results have been obtained with a package of 10 diameters overall length.
Loss Prevention through Process Instrumentation — The Continuous Thermocouple
Authors: Smith Cyril
Published: November 2015

A different breed of thermocouple provides enhanced temperature sensing and fire prevention, without the limitations of other sensing systems.
Metrological Analysis and Optimization of Electronic Transducers Based on Universal Programs for CAA of Electronic Circuits
Authors: Sidor Tadeusz
Published: November 2015

CAA programs of electronic circuits widely employed in electronics can also be used for evaluation of the metrological properties of various measuring transducers. For this, certain additional options are required which are not necessarily met by the most popular programs. The paper discusses this and compares the usefulness of three programs — SPICE, MICRO-CAP and NAP-2 – for complex metrological analysis of electronic transducers.
Using Ultrasonics to Measure Process Variables
Authors: McKnight J A , Clare A
Published: November 2015

Ultrasonics can be used in industrial processes to measure a number of variables. Liquid level can be determined by pulse-echo techniques. Flowrates can be measured by time-of-flight or doppler methods. The latter can also provide flow distributions. Fluid temperature and solute concentrations can be deduced from the sonic velocity. Particle and gas contents can also be monitored. Ultrasonics is essentially a non-invasive technique, and technology suitable for high temperature or corrosive conditions is available.
Use of Fixed Airflow Monitors in Coal Mines
Authors: Unwin I D
Published: November 2015

This paper consists of edited extracts taken from a book entitled The Measurement of Air Flow in Coal Mines which in turn was derived from a thesis presented by the author to Nottingham University in 1988 for the award of the degree of Master of Philosophy, work which was undertaken with the sponsorship of the British Coal Corporation. The book is published by the author, from whom copies are available at 1 Primrose Meadow, Midway, Burton on Trent, Staffs DE11 0XH. Tel: 0283 221892
Galvanometers and the Invention of Self-Balancing Recorders
Authors: Matsumoto Eiju
Published: November 2015

This paper describes the history of ink recorders from their use with the first submerged transatlantic cable to the invention of self-balancing recorders. At the time of submarine telegraphy, Kelvin galvanometers, as well as siphon recorders, were used as telegraphic receivers. Direct-driven thread recorders and self-balancinig recorders, such as the Callendar recorder and the mechanically sensing potentiometric recorder, also employed galvanometers as detectors. Before the advent of vacuum tubes and semiconductors, the galvanometer was the key component of measuring instruments.
Religious Instruction — An Anachronism?
Authors: Hill Brian V.
Published: November 2015

The time has come to remove poetry from the curriculum of general education. For too long we have imposed on students a form of experience — poetry — which is the plaything chiefly of a particular social group, a cultural elite. At the least, in a democratic society, the study of poetry should be available merely as an option, certainly not as a compulsory subject. At best, it should probably be deleted altogether. The enjoyment and production of poetry are very personal things, depending more on subjective inclination than pedagogic instruction. Again, literary criticism is notoriously subjective; more a product of one's own imagination than a valid analysis of someone else's. For these and other reasons, poetry cannot legitimately be regarded as a form of knowledge, amenable to proof. Treated as a school subject, poetry either functions as a holiday from serious work or degenerates into a mechanical sifting of metaphors and similes from unnecessary cryptic stanzas. We cannot allow a curriculum for democratic education to be hamstrung by such an anachronism. Let those who still believe in the teaching of poetry teach it in their own way to whomever they can cajole to listen, outside the boundary of the public school.
Three Dimensional Analysis and Resulting Design Recommendations for Unidirectional and Multidirectional End-Notched Flexure Tests
Authors: Davidson B. D. , Kruger R. , König M.
Published: November 2015

Results are presented from a theoretical investigation of the effects of stacking sequence on the energy release rate in laminated composite end-notched flexure test specimens. Deflections and energy release rates of unidirectional and multidirectional ENF specimens are obtained by classical laminated plate theory, shear deformable plate theory, and three dimensional finite element analyses. It is shown that the distribution of energy release rate varies across the front of an initially straight delamination. The percentage of mode II and mode III energy release rates for the specimen, as well as the local peak values of the mode II, mode III and total energy release rates that occur at the specimen's free edges are shown to correlate with a nondimensional ratio comprised of the specimen's flexural rigidities. The results of the study are used as a basis for a proposed “ENF test design procedure” that may be used for the determination of appropriate specimen stacking sequences and test geometries for studying delamination growth at interfaces between plies at various orientations. The test design procedure minimizes the contributions to the energy release rate from residual thermal stresses, geometric nonlinearities, local mode II concentrations at the specimen's free edges and local mode III effects.
Sitting and Smiling Behavior of Baganda Infants
Authors: Kilbride Janet E. , Kilbride Philip L.
Published: November 2015

Previous research has noted that the Baganda of Uganda are comparatively accelerated in the rate of their psychomotor development. As part of a longitudinal study of mother-infant interaction and infant psychomotor development during the first six months of life, when precocity had been found to be greatest, the present investigation reports on two psychomotor skills, smiling and sitting, which are socially significant to the Baganda themselves. Infants are encouraged and/or specifically trained in the development of these skills and perform them at an earlier age than the American norms on the Bayley Scales of Infant Development, the assessment instruments used. These findings provide additional support for the proposition that culturally constituted experience is importantly related to the psychomotor development of infants.
Recent Trends in Dental Caries in U.S. Children and the Effect of Water Fluoridation
Authors: Brunelle J.A. , Carlos J.P.
Published: November 2015

The decline in dental caries in U.S. schoolchildren, first observed nationwide in 1979–1980, was confirmed further by a second national epidemiological survey completed in 1987. Mean DMFS scores in persons aged 5–17 years had decreased about 36% during the interval, and, in 1987, approximately 50% of children were caries-free in the permanent dentition.

Children who had always been exposed to community water fluoridation had mean DMFS scores about 18% lower than those who had never lived in fluoridated communities. When some of the “background” effect of topical fluoride was controlled, this difference increased to 25%. The results suggest that water fluoridation has played a dominant role in the decline in caries and must continue to be a major prevention methodology.
An Evaluation of the Use of Professional (Operator-applied) Topical Fluorides
Authors: Ripa L.W.
Published: November 2015

Application of fluoride solutions, gels, varnishes, and prophylaxis pastes is reviewed as well as the sequential APF/SnF2 office-rinse method. The most widely-used technique is with 1.23% APF gel (12,300 ppm F) in trays. Clinical results from this method are similar to those achieved with an APF solution of the same fluoride concentration. A professional APF gel/tray application need not be preceded by a prophylaxis, should last four min, and should not be followed by a water rinse for 30 min. Fluoride varnishes are newer topical fluoride agents, but their relative efficacy, compared with other proven caries-inhibitory methods, remains to be fully determined. In general, fluoride prophylaxis pastes have not been shown to inhibit caries; however, their use is justified by the ability of some to replenish fluoride lost from the abrasive action of the paste on tooth enamel. The sequential office-rinse method has not been tested in randomized clinical trials, and its use cannot be recommended.
Developing Computer Assisted Interviewing (CAI) for the National Household Survey on Drug Abuse
Authors: Lessler Judith T. , Caspar Rachel A. , Penne Michael A. , Barker Peggy R.
Published: November 2015

The National Household Survey on Drug Abuse (NHSDA) is the nation's primary data source for information on the scope and dimensions of drug abuse in the United States. To improve data collection, the NHSDA was converted to a computer-assisted interview (CAI) format in 1999. This paper reports on the research that was done to guide the conversion. The main focus of the paper is on a large (n=1,982) field experiment that examined different audio computer-assisted self-interviewing (ACASI) procedures in the fourth quarter of 1997. This field experiment showed that ACASI is likely to increase reporting of drug use among youth; that respondents can, on their own, correct inconsistencies in responses that are detected by the computer; and that ACASI eases the response task for poor readers and less well educated respondents.
Response Reliability and the Study of Adolescent Substance Use Progression
Authors: Golub Andrew , Labouvie Erich , Johnson Bruce D.
Published: November 2015

Studies of adolescent substance use progression typically infer a sequence of initiation from self-reported ages at first use of alcohol, tobacco, marijuana, and hard drugs. This paper examines the reliability of this procedure for a sample of 892 New Jersey youths interviewed on two occasions separated by three years. Individual responses on the second occasion differed substantially from those provided on the first. However, the inferred sequences were consistent as long as 1) first use of alcohol and/or tobacco was considered a single stage, and 2) cases in which individuals initiated the use of two substances in the same year were considered as ambiguous regarding order. The sequences reported were also consistent with the gateway theory that suggests alcohol/tobacco precedes any possible use of marijuana and hard drugs.
Investigating Potential Differences between Cocaine Users and Distributors Using the Ion Mobility Spectrometer
Authors: Mieczkowski Tom , Hussey Barbara , Mumm Rosemary , Connick Harry F.
Published: November 2015

This article examines the possibility of using the ion mobility spectrometer (IMS) to discern the difference between persons who distribute cocaine and those who do not distribute cocaine based on their patterns of cocaine contamination. Criminal justice practitioners who monitor offenders rely primarily upon urinalysis to detect drug use by their clientele. However, since drug distribution is a profitable enterprise for many, persons may continue to engage in drug sales even after desisting from use. In this paper we attempt to determine whether or not a distinct contamination profile exists for persons who admit continued involvement in drug sales and drug sales and use when contrasted to those who deny drug sales but continue to use or deny any drug involvement whatsoever. The findings of our examination and analysis are only moderately supportive of the discernable difference between users and distributors but sufficient, in our view, to continue examining the technology for a potential application to this problem.
Estimation of Heroin Prevalence in Michigan Using Capture-Recapture and Heroin Problem Index Methods
Authors: Calkins Richard F. , Aktan Georgia B.
Published: November 2015

Valid estimates of illicit drug use prevalence are essential for substance abuse treatment and prevention services planning. This study utilizes capture-recapture and heroin problem index methods to estimate heroin use prevalence for specific geographic areas and time periods in Michigan and compares the estimates with those obtained from a previous study that utilized an identical methodology as well as with estimates from an adult household telephone survey. The results show significant increases in heroin use in Michigan and in the city of Detroit from 1975 to 1992. The results also demonstrate that estimates of heroin use prevalence from capture-recapture and heroin problem index methods provide much higher estimates of heroin use than can be obtained from surveys alone and better agreement with known numbers from administrative records. Capture-recapture and heroin problem index methods are useful in the prevalence estimation of heroin use and possibly other illicit drug use, such as cocaine or crack, which may be underestimated in surveys.
Anonymity and Confidentiality in School Surveys on Alcohol, Tobacco, and Cannabis Use
Authors: Bjarnason Thoroddur , Adalbjarnardottir Sigrun
Published: November 2015

School surveys are currently the most important method of collecting data on alcohol and drug use among youth. Although methodological studies suggest that school surveys yield reliable and valid estimates of substance use among youth, it has been argued that results will be affected by the level of perceived anonymity. Longitudinal research designs raise an important question in this respect since follow-up makes complete anonymity impossible. In fact, responses to such surveys should be regarded as confidential rather than anonymous. This study compares the reported use of cigarettes, alcohol and cannabis between an anonymous, cross-sectional survey and a confidential, longitudinal survey. Both females and males in the confidential survey have a slightly higher rate of non-response for lifetime cannabis use. Furthermore, females tend to be slightly less likely to admit to any use of alcohol and cannabis in the confidential survey, and those who do admit to having used cigarettes and alcohol, report slightly fewer occasions. The correlations between use of cigarettes, alcohol, and cannabis are not affected by this bias. These results add further support to earlier research that has found school surveys to be a robust method of data collection, and suggests that the bias introduced by identification numbers in longitudinal research has limited practical significance.
Impact of Case Management on Use of Health Services by Rural Clients in Substance Abuse Treatment
Authors: Vaughan-Sarrazin Mary S. , Hall James A. , Rick Gary S.
Published: November 2015

This research evaluates the effect of case management on the utilization of substance abuse, medical, and mental health services by substance abuse treatment clients subsequent to initiating residential treatment. The study also evaluates whether the proximity of the case manager to the treatment facility and use of a telecommunication system are related to case management effectiveness. Clients were randomly assigned to one of four conditions. Three conditions received case management according to the Iowa Case Management model and differed according to the location of the case manager and use of a telecommunication system. A fourth condition received standard treatment services. Clients provided feedback regarding service use for 12 months. Results indicated that when case managers were located at the treatment facility, they had an impact on clients' use of substance abuse treatment and medical services. Clients who were assigned to case managers located at the treatment facility used more treatment aftercare and medical services after admission to residential treatment than clients who received standard treatment. These effects were not found for clients assigned to case managers not located at the facility. Case management was not related to the use of mental health services subsequent to treatment.
Prostitution, Drug Use, and Coping with Psychological Distress
Authors: Young Amy M. , Boyd Carol , Hubbell Amy
Published: November 2015

The purpose of this study was to explore the severity of substance abuse and reasons for using drugs among prostituting African American women who smoke crack cocaine. Specifically, we were interested in examining whether prostitutes use drugs as a means of coping with intra- and interpersonal experiences commonly associated with their occupation. Using a convenience sample of 203 African American women with a history of crack smoking, participants were interviewed and asked a variety of questions including whether they had ever engaged in prostitution as a source of income and the severity of and reasons for their drug use. Women who were prostituting, in contrast to those who were not, were found to have a significantly higher severity of drug use and were significantly more likely to use drugs to increase confidence, control, and closeness to others and to decrease feelings of guilt and sexual distress. We argue that women may enter prostitution in order to fund their drug use; however, prostitutes likely increase their drug use in order to deal with distress caused by activities associated with their occupation. The need to address the mental health issues of prostitutes who are abusing illicit drugs is discussed.
Gender Differences in How Intimate Partners Influence Drug Treatment Motivation
Authors: Riehman Kara S. , Hser Yih-Ing , Zeller Michelle
Published: November 2015

We examine associations between partner-related variables (i.e., partner's economic support, drug use, treatment experience, and recent partner conflict) and treatment motivation (i.e., drug use problem recognition, desire for help, and treatment readiness). Participants were 266 cohabiting or married individuals recruited from STD clinics, emergency rooms, and jails in Los Angeles County between 1992 and 1994, who reported recent drug use. Multivariate analyses show that for men, partner-related variables are not strong predictors of motivation. For women, however, several partner-related variables significantly predict motivation. Having a partner who has been in treatment increases the odds of women's desire for help and treatment readiness, and having a partner who uses drugs decreases the odds of women's treatment readiness. For both men and women, deriving a greater amount of income from self sources than from a partner is associated with increased treatment motivation.
Substance Use and Self-Reported Mental Health: The Moderating Effect of Acquaintance Use Behavior among Adults
Authors: Ford Julie
Published: November 2015

A considerable body of literature has documented the positive effects that social relationships have for mental health. Similarly, a number of studies have demonstrated the importance of peer and acquaintance networks in attempts to understand substance use. The present study brings together these disparate fields and examines the relationship between individual alcohol and marijuana use and self-reported mental health, and, in particular, whether acquaintance substance use behavior may, under certain conditions, moderate this association by providing a normative context of acceptance. Based on an analysis of a community-based sample of 23,932 adults from 41 mid-sized cities nationwide, the findings indicate that in addition to the detrimental relationship between individual's substance use and mental health, substance use on the part of acquaintances increases the odds of reporting poor mental health, irrespective of the respondent's own use or non-use. However, the relative effect of acquaintance substance use behavior is smaller for those individuals who use than for those who do not: among users of alcohol and marijuana, having acquaintances who also use is associated with a lesser increase in odds as compared to those who do not use but whose acquaintances do. These results suggest that the degree of normative congruity between individual behavior, the “local” context formed by peers and associates, and the broader societal context is a variable factor which is implicated in the relation between substance use and mental health.
Self-Perceived Job Skills and Employment Barriers among Non-Drug Using and Chronic Drug Using Welfare-to-Work Participants
Authors: Atkinson John , Lee Doohee , Dayton-Shotts Cheryl , French Catherine
Published: November 2015

This study examined the extent to which self-perceived work-related skills and barriers to employment are associated with current employment status among a sample of recipients of Temporary Aid to Needy Families (TANF). The degree to which these perceptions differed between chronic drug using and non-using women in the sample was then assessed. The probability of employment was significantly affected by conceptions of self-competencies and barriers faced. Chronic drug use independently further reduced the chances of employment. Policy implications for TANF's mandatory work requirements are discussed in light of these findings.
12-Step Program Participation and Effectiveness: Do Gender and Ethnic Differences Exist?
Authors: Hillhouse Maureen P. , Fiorentine Robert
Published: November 2015

Although 12-Step is increasingly utilized as a recovery resource and is viewed by many addiction specialists as an integral component of treatment and long-term recovery, questions regarding participation and effectiveness of 12-Step programs for women and ethnic minorities have been raised. Utilizing data from the Los Angeles Target Cites Evaluation Project (n = 356), participants in adult outpatient alcohol and drug treatment were followed for 24 months and rates of 12-Step participation and effectiveness were assessed for all gender and ethnic groups. Contrary to reports that 12-Step is more appropriate for European-American males, statistical analyses reveals that women and ethnic minorities are equally likely to attend 12-Step programs, and to recover In conjunction with such participation as European-American males. Although 12-Step may not appeal to all seeking to cease alcohol and drug use, the clinical implications for treatment providers and other addiction specialists points to the benefits of Integrating 12-Step components into traditional treatment programs and recommending 12-Step participation for clients of all gender and ethnic groups.