Continuous Principle Research Articles

Children are in control

We argue on the basis of recent experimental results that modular principles of universal grammar (UG) play a continuous role in the first language acquisition of control. Our results involve both comprehension and production data from 108 3- to 8-year old children who are acquiring English. The results provide evidence against the hypothesis that there is a “stage” at which children do not know fundamental grammatical principles of control, or fail to apply the basic structural analysis relevant to control. We suggest that previous proposals for this hypothesis have been misled by (1) attention to only one aspect of the knowledge of control, namely choice of antecedent in comprehension of the embedded null subject in these structures and (2) misinterpretation of the nature of the principle by which children overgeneralize the choice of object as antecedent in control structures. Although the new results do replicate delay in acquisition with the unique subject- control verb “promise”, they suggest that this delay is caused by a need to integrate modular principles of UG with language-specific principles by which the lexicon and syntax (constituent structure and case) are related. The overgeneralization of choice of object as antecedent is shown to reflect a continuous principle of syntactic minimality.

Optimization of a tubular nylon 6 reactor with radial gradients

AbstractOptimal jacket‐fluid temperature profiles for tubular Nylon 6 reactors (in the presence of radial gradients of temperature and concentration) have been obtained using an algorithm based on the continuous minimum principle developed for a distributed parameter system. A gradient search technique has been devised and implemented for obtaining these optimal profiles. The optimal temperature profiles are found to be at the maximum permissible temperature, Tmax, at the beginning of the reactor and then slowly decrease to the minimum permissible temperature, Tmin, near the end of the reactor. The effect of varying several parameters is also studied. The desired value of the chain length and the reaction time are found to be the parameters which effect the optimal profiles most significantly.

Optimal temperature policies for catalytic transport reactors under periodic operation

AbstractThe influence of inlet gas concentration cycling on the optimal temperature policy of catalytic transport reactors is studied theoretically. The model considered is based on plug flow of gas and catalyst particles with negligible interand intra‐particle diffusional resistances and concentration dependent deactivation kinetics. To utilise the concentration of the reactant and the activity of the deactivating catalyst fully a proper temperature sequence along the reactor is needed. Thus, a general optimal temperature policy using the continuous minimum principle is derived for the reactor under periodic operation. The model equations are solved analytically for gas concentration, activity and temperature profiles. Resonance behaviour (maximum in conversion with pulse width) is obtained using the optimal temperature policy for certain sets of parameters. The effects of activation energy groups, reaction and deactivation constant groups and inlet temperature on the optimal temperature policy under periodic operation are evaluated. In all cases an improvement in conversion with the optimal temperature policy under periodic operation over that with an isothermal policy under periodic operation is obtained. A suboptimal policy, comprising constant temperature over different reactor sections, which is useful for implementation purposes is also discussed.

Yoruba relativization and the continuous segment principle

This paper examines the strategies for relativisation and the Noun Phrase accessibility hierarchy and constraints in Yoruba [Keenan and Comrie 197T]. The various positions relativisable are examined. It was found that contrary to what Keenan and Comrie thought, Yoruba relativises all positions except the Object of Comparative. Attention is also focussed on the status of the coreferential pronoun found in subject relativisation. From the presence of this pronoun it appears as if Yoruba violates the continuous segment principle. However, our analysis shows that the pronoun is a surface structure phenomenon which obscures the underlying strategy for relativisation. The Yoruba data therefore supports the Hierarchy Constraints.

Optimal reflux rate policy determination for multicomponent batch distillation columns

This paper describes a procedure to obtain optimal reflux or optimal distillate rate policy for multicomponent batch distillation columns using the Pontryagin's continuous maximum principle. For application to multicomponent systems, a reduced order model is used using short-cut procedure developed specifically for analysis and design of batch columns.

The Failure of British Counter-Espionage against Germany, 1907–1914

Modern British counter-espionage effectively began in April 1907, when a joint conference of naval and military officials, formed the previous year to consider ‘the Powers Possessed by the Executive in Time of Emergency’, recommended both an immediate strengthening of the laws against espionage, and a War is Office investigation of ‘the question of police surveillance and control of aliens’. These recommendations were to prove an important initiative, and did much to determine the course of British counter-espionage before 1914, yet at the time they probably seemed little more than an airing of old grievances unlikely to find new support, for they were among the last remnants n. of the abortive ‘Emergency Powers Bill’ which the War Office intelligence department had been advocating to strengthen home defence ever since the invasion scare of 1888. The 1906 joint conference had in fact hoped to further the cause of this great legislative package, with its radically new powers of access, requisition and seizure but, faced with the Liberal administration's commitment to the ‘continuous principle’ that a full-scale landing was impossible, had been forced instead to confine itself to the purely naval and military aspects of home defence. As its report confessed in April 1907, in the prevailing climate of opinion the only hope for the great ‘Emergency Powers Bill’ was as a series of ‘small and independent measures’.

Development of an optimal linear controler for antibiotic fermentation

The optimization method based on the Pontryagin's continuous maximum principle and was used to predict the optimal specific growth rate profile for a typical antibiotic fermentation model with a given nominal set of start values and parameters. If this set is unknown or known only to be in some domains for the process, then it is necessary to use an o ptimal l inear c ontroler (OLC). The behaviour is demonstrated by simulation runs.

Development of the Different RFQ Accelerating Structures and Operation Experience

Fourteen years after the invention of the spatially continuous strong focusing principle in the USSR and five years after the start of the RFQ research program in the USA numerous (~ 15) laboratories all over the world are concerned with this new accelerator concept and many projects are under way. In this paper a brief review of these activities and the considered applications is given and the different approaches in beam dynamics, electrode configuration and resonators are outlined.

Variational Principle for Potential Fields from the Graph-Theoretic Field Model

In this paper, we derive discrete variational principles of potential field problems by applying the difference form of Tellegen's theorem to the Graph-Theoretic Field Model (GTFM) of a field. The continuous model variational principle is then obtained from its discrete counterpart by the application of a limiting process. The procedure herein is in marked contrast to the existing procedures whereby the variational principles are derived by applying mathematical operations to the partial differential system. The procedure holds promise for providing a framework for deriving variational principles of fields with anisotropic, nonlinearity or coupled processes.

Maximum cell productivity by repeated fed‐batch culture for constant yield case

AbstractOptimal operation of repeatedly fed‐batch was determined by the continuous maximum principle for the constant yield case. The objective of maximum cell productivity for a fixed cell concentration was achieved by finding the substrate feeding policy that minimized the processing time. Analytical criteria for the optimal filling policy show that an exponential policy is optimum when the specific growth rate has a maximum, and also that operation in the simple repeated batch mode is optimum when the specific growth rate is monotonic increasing. Comparisons between optimal repeated fed‐batch culture and other modes of operation were made for the case of substrate‐inhibited growth. Cell productivity by repeated fed‐batch exceeds both batch and continuous operation for the case of low residual substrate concentration.

Sources of error in spectroradiometry

Systematic errors in spectroradiometry, as in other areas of metrology, are difficult to quantify. An attempt is made here to identify potential sources of error that can occur at the various stages of the measurement process and to suggest ways in which they might be avoided or, at least, kept to a minimum. The special problems that arise in the case of sources, such as discharge lamps, with complex line spectra have led to the development of a new type of spectroradiometer system, based on a continuous scan principle.

Evaluation of an AutoAnalyzer method for quantitating anti-A and anti-B haemagglutinins in factor VIII preparations.

The continuous flow principle employed in the Technicon AutoAnalyzer has been adapted for the assay of anti-A and anti-B. The method has an acceptable degree of reproducibility and has been used, principally, for the quantitation of anti-A and anti-B in factor VIII concentrates of intermediate activity. It is, however, a method that can be applied to the assay of these antibodies in serum samples.

Optimal aeration control in a post-aeration basin

Abstract The optimal aeration policy in a post-aeration basin is investigated. The physical problem is formulated using a dispersion model to describe the dissolved oxygen and the pollutant concentrations. The mathematical model is amenable to the Pontryagin's continuous maximum principle which reduces the optimization problem to a boundary value problem. The optimal aeration policy is determined by numerically integrating the boundary value problem. Simulations are made to show the important effects of the inlet waste strength, the flow pattern and the flow retention on the optimal aeration policy.

Spectral changes of the fluorescent acriflavine--(Feulgen) DNA dye complex at different temperatures: application of a new cryostat for measurements in reflected and transmitted light.

The fluorometric behaviour of cellular objects is influenced during excitation by two nearly independent phenomena: (1) by the photochemical reaction of the DNA/AF dye complex, and (2) by the energy transfer among several DNA/AF dye complexes. Both processes show a distinct temperature-dependent behaviour and can therefore be characterized by the analysis of the fluorescence spectra at different temperatures. All microfluorometric measurements were performed with a self-constructed cooling device. The cryostat permits measurements of the cellular fluorescence within a range of temperatures between 4 K and 300 K. The cooling unit operates in accordance with the 'Continuous Flow Principle' and allows the application of objectives up to a numerical aperture of 0.6.

Interpretation of complement fixation test results as displayed on Auto-Analyzer charts

Abstract The Auto-Analyzer is used to perform complement fixation testing for the Brucellosis Eradication Scheme. In this system, the reactions of the complement fixation test are carried out using the continuous flow analysis principle. A colorimeter measures the transmittance of red cells left in suspension at the end of the reactions and this is traced on to the Auto-Analyzer recorder chart. The normal trace consists of a “standard” control serum, which corresponds to 50% haemolysis of red cells, followed by 39 small crests indicating negative samples. Any sample giving a peak equal to or higher than the standard serum is positive. Aberrant traces may be caused by carry-over from positive samples, poor sample preparation, and machine or reagent faults.

The design and operation of the Central Brucellosis Laboratory

Abstract The automated complement fixation test is the definitive test in New Zealand's Brucellosis Eradication Scheme. All automated complement fixation testing is carried out at the Central Brucellosis Laboratory, which receives sera from a network of 18 District Processing Centres. The Central Brucellosis Laboratory is a processing facility backed by laboratories concerned with reagent preparation, quality control, and problem-herd investigation and development. The complement fixation test is carried out using the continuous flow analysis principle of the Auto-Analyzer and is a fully automated, but rigid, system. If a titre is required for a serum sample, a semi-automated microtitre apparatus is used. Under practical working conditions, each Auto-Analyzer is capable of a sustained rate of 65 samples/hour. Thus with 30 Auto-Analyzers “on-line”, the Central Brucellosis Laboratory can maintain a rate of 15 000 tests/day. In New Zealand the maximum processing rate is likely to be approached or exceeded in...

Full-Band Low-Loss Continuous Tracking Circulation in K Band (Short Papers)

The continuous tracking principle is applied to the design of a wide-band Y-junction stripline circulator for the 18-26.5-GHz frequency band. Near octave low-loss and high isolation performance is demonstrated without the need for repeated design cycles. Design data and construction details are presented.

Measurement of carbon dioxide in blood.

The remarkable combination of physical and chemical properties displayed by carbon dioxide has enabled the development of a very wide variety of analytical methods for its measurement in blood or blood plasma. Both for historical and technical reasons, the gasometric method of Van Slyke and Neill is preeminent, but great skill is needed to realize its full precision and accuracy. The microgasometer of Natelson, however, has served the clinical laboratory well as a practicable manual means of microanalysis for total carbon dioxide. So far as automated analysis is concerned, it is highly significant that one of the first applications of Skegg's continuous flow principle was to the titrimetric determination of total carbon dioxide in serum; the AutoAnalyzer technique remains the most widely used of its kind, in spite of inherent difficulties in specimen handling, instrumental standardization, and quality control. At the same time, it has been pointed out that the routine determination of total carbon dioxide in serum does not offer a useful screening procedure for identifying or characterizing patients with acid-base disorders; full assessment of acid-base status, including pCO2 in selected patients is much more rewarding. The credit for bringing pCO2 measurements within the scope of the clinical laboratory, by means of the interpolation technique, is largely due to Astrup and his colleagues. Nevertheless, continual improvements have been made in the design and performance of the Severinghaus type of pCO2 electrode, so that reliable instruments offering direct readout of blood pCO2 are available from several manufacturers. The more elaborate versions of these instruments are rugged and work-simplified, and they offer automated self-calibration and end-point detection for pH and pO2, as well as pCO2. It will be surprising if such instruments do not come into widespread use.

A microscope stage sample holder for microfluorometric measurements of biological specimen in the range of temperature between 3.5 to 300 K

A cryostat was constructed, which permits measurements of the intracellular fluorescence within a range of temperature between 3.5 to 300 K. The cooling unit operates in accordance with the "Continuous Flow Principle" and allows the application of objectives up to a numerical aperture of 0.6. It results from measurement of BAO Feulgen stained nuclear DNA, that a decrease of fluorescence intensity is caused by two different mechanisms: (1) There is a highly temperature dependent effect, originating from phenomena of solid physics, and (2) a second effect, which is almost temperature independent, and can be explained as a photochemical reaction.

A continuous flow cooling unit for ESR experiments over the temperature range 3.7-300K

A variable temperature liquid helium cooling unit for use with ESR spectrometers is described. The unit is based on the continuous flow principle and the advantages of this method, particularly with regard to ESR experiments are explained. The unit is part of a complete cryogenic system which includes a flexible gas cooled helium transfer tube, a gas flow pump and controller and an automatic temperature controller. Sample temperatures between 3.7K and 300K can be obtained readily and the stability varies between +or-0.02K and +or-0.08K over this range. The total helium consumption of the system varies between 1.01 h-1 at 4.2K and 0.51 h-1 at 10K and decreases further with increased temperature. This compact cooling unit is well suited to other experiments with restrictive geometries.