Search

A novel approach has been developed by applying queueing theory to hydrologic modeling. A queueing situation is characterized by a flow of customers arriving randomly at one or more service facilities. In this case, the customers are represented by water and the service time is the time it takes to move through the soil and over the land. This approach has the potential to be simpler and more efficient than some previously developed models. Another important attribute of queueing theory is its ability to model almost unlimited detail. Many simulation languages based on queueing theory have been developed and tested and are available. Applications of the languages include manufacturing operations, transportation systems, computer systems, financial planning, and health care systems. A model was developed, using a simulation language, to predict runoff hydrographs from storms occurring on small homogeneous watersheds. With continued development, queueing theory could provide an effident, detailed approach to simulating many natural processes.

PREDICTIONS of water-table positions and drain spacings computed using theoretical transient drain spacing equations were compared with the measured performance of subsurface drains installed in a relatively shallow lacustrine soil in southern Alberta, Canada. Results from empirical drain spacing equations, which were developed by measuring the performance of subsurface drains installed at depths of 0.76, 1.22 and 1.68 m, were compared with computations using theoretical drainage equations. The Bouwer and van Schilfgaarde equation, using a C-factor of 1.0, most closely predicted the measured performance of the existing drains under all conditions. The accuracy of the equations, and the range in average absolute deviation in drain spacing predictions (in brackets), was Bouwer and van Schilfgaarde, C=1.0 (4 to 9%) > van Schilfgaarde (6 to 13%) > Modified Glover (10 to 16%) > Bouwer and van Schilfgaarde, C=0.8 (11 to 19%) > Glover for drains placed on the barrier (23 to 40%) > Hammad, thick layers (40 to 59%) > Hammad, thin layers (35 to 110%). Individual equations generally predicted according to theory, provided the theoretical assumptions of the equations approximated field conditions.

A single-photon counting system has been developed for measuring gas laser parameters. A linear accelerator provides nanosecond-wide pulses of heavy charged particles which are injected into a specially designed cell. The charged particles excite gas mixtures, and the temporal response of the emitted radiation is observed as a function of wavelength. The resulting data is analyzed to obtain pertinent parameters such as excited-state lifetimes, reaction rate constants, and quenching rate constants. At the present time nuclear pumper laser candidate gases are being examined.

The integration testing and system testing strategies used in the development of the Traffic Service Position System No. 1B (TSPS No. 1B) are described in this article. It discusses novel methods developed for the integration and testing of the first embedded application of the 3B20D Processor and DMERT operating system. The new testing techniques and project management aides, which were vital to the achievement of system quality for the Bell System service, are described. The first TSPS No. 1B went into service on November 20, 1981, in Fresno, California.

Fifty-two survivors of childhood cancer and their families were assessed by questionnaire and interview to determine survivors' psychosocial status two years or more after treatment. Most were functioning well and serious psychosocial problems were relatively rare. Communication patterns during treatment were most predictive of psychosocial outcome whereas indicators of medical severity were least predictive. The heterogeneity of effective coping styles, appropriate to varied personality types, was noted.

Relative excitation efficiencies are reported for the fluorescence at 173 nm in liquid xenon excited by 0.5 MeV electrons (β particle), 6 MeV alpha particles (α particle), and 90 MeV fission fragments (ff). Efficiencies at 173 nm are also reported for alpha particle and fission fragment excitation of high pressure xenon. Results are presented in the form of ratios which compare the fluorescent output per unit energy for excitation by the different particles. The β/α and α/ff ratios for liquid xenon are 1.25±0.5 and 3.5±1.2, respectively. For xenon at 2000, 3000, and 4000 Torr, the α/ff ratios are 0.60±0.25, 0.61±0.23, and 0.63±0.24, respectively.

This study provides a tentative explanation of the spatial distribution of economic activity in Canada, with a focus upon the role of inter-industry linkages. Location of economic activity for each of one hundred and nine three-digit S.I.C. manufacturing industries is explained by use of a “tobit” model incorporating backward and forward linkage variables. The two sets of linkage variables in each tobit equation were reduced by extraction of one principal component from each set, using the matrix of cosines of the variables. A set of control variables completes the set of explanatory variables. The overall explanatory power of our equations was remarkably high and the role of inter-industry linkages is unmistakable.

Inversion relaxation cross sections for the J=3, K=2 upper state of NH3 were measured using a beam maser spectrometer. Scattering gases were NH3, ND3, HCl, and H2O. For NH3–NH3 scattering the angular resolution was varied from 1.5° to 0.2° with little effect on cross sections. Cross sections for NH3 and ND3 as scattering gases were equal within experimental error. The result that beam maser cross sections are relatively independent of angular resolution is discussed. Calaculated angular resolution corrections are compared with values of beam attenuation cross sections and total cross sections obtained from the present data. Comparison is made between our pure state (σ1) and superposition state (σ11) cross sections and recent gas‐cell data.

A randomised pilot study is reported of d(15) + Be neutrons compared with 4 MV photons in the treatment of patients with astrocytoma. Sixteen patients were treated by photons and 18 by neutrons. Both treatments were well tolerated by patients. The median survival after photons was 11 months and after neutrons, 7 months. It was demonstrated that four of nine patients treated by neutrons had evidence at autopsy of radiation-induced brain damage. All had residual cancer. No patient treated by photons had signs of radiation-related morbidity. The trial was, therefore, discontinued prematurely.

The attributes of sexual differentiation of host-relationships in certain species ofAphelinidae whose females develop as primary parasites and whose males develop hyperparasitically are described with the aid of an example. The relevance of the phenomenon to population regulation and to biological control is discussed.

The effect of the initial substrate surface condition, as indicated by the critical surface tension for wetting, on the rate of attachment of marine bacteria to a variety of solid surfaces has been measured. The techniques used to determine the number of bacteria attached per unit surface area were a lipopolysaccharide test utilizing Limulus lysate and direct examination of the surface by scanning electron microscopy. The results obtained by the two techniques are compared and their significance to the control of microbiological slime film formation (microfouling) is discussed.

The (n,2n) excitation function for 50Cr and the (n,2n) and (n,p) excitation functions for 52Cr have been measured in the energy range 14.2-18.2 MeV. Activation techniques using the mixed-powder method and a Ge(Li) detector gamma-ray spectrometer were utilized in the measurements. Neutrons were produced by the 3H(d,n)4He reaction. Using the 27Al(n, alpha )24Na reaction to monitor the neutron flux, the measured cross section values at the respective neutron energies of 14.2+or-0.2, 15.2+or-0.2, 16.2+or-0.2, 17.2+or-0.2 and 18.2+or-0.2 MeV were found to be 13+or-1, 33+or-3, 56+or-4, 66+or-6 and 78+or-6 mb for the 50Cr(n,2n)49Cr reaction, 285+or-26, 415+or-37, 456+or-40, 456+or-40 and 511+or-48 mb for the 52Cr(n,2n)51Cr reaction and 67+or-6, 63+or-5, 57+or-4, 46+or-5 mb for the 52Cr(n,p)52V reaction. The associated-particle method was also used to determine the neutron flux at 14.2 MeV in order to check the mixed-powder results. The average cross section values for four associated-particle measurements at 14.2 MeV were found to be 14+or-1 mb for the 50Cr(n,2n)49Cr reaction, 284+or-24 mb for the 52Cr(n,2n)51Cr reaction and 70+or-6 mb for the 52Cr(n,p)52V reaction.

Introduction The measurement of in situ stresses is now much easier and more reliable than seven or eight years ago. This is primarily due to improvements, both in the solid state electronics of read out devices and in the epoxy glues used to attach strain gauges to rock. In addition the micro computer now facilitates immediate evaluation of field test data. This paper discusses the results of a field investigation into the measurement of locked-in stress in a massive sandstone. In addition, the geological factors affecting the behaviour of the sandstone, including changes of loading and geometry due to a road cutting excavation, are examined. Finally, a remedial treatment is proposed to overcome problems which developed after construction and as a consequence of the locked-in stress. A major road cutting constructed by the Department of Main Roads, New South Wales is located south of Wyong within the Sydney Basin of eastern Australia (Fig. 1). The general profile of the road cutting incorporating the site stratigraphy is shown in Fig. 2.> Thirty-five metres of shale overlie a massive sandstone exposed for 25 m of a known 30-m thickness. Underlying the sandstone is additional shale. Excavation of the cutting was achieved by ripping in the shale layers and by blasting in the massive Wyong sandstone. The sandstone was presplit prior to blasting. Two years after excavation, and before the road has been opened to public traffic, continual spailing of the 1/4:1 sandstone batter has occurred and become steadily worse. Over a three

The No. 1 ESS ADF magnetic tape subsystem provides a high-volume, low-cost storage medium in which user messages are filed, and from which current message copies can be automatically retrieved upon user request. Message handling and statistical information concerning all message switching transactions are also filed on tape, providing a journal record for the switching center. Emphasis on maintenance and defensive programming techniques enables the tape subsystem to provide continuous and excellent service. This article describes the tape equipment and program package.

A molecular beam maser spectrometer was used to measure hyperfine structure on the J=1→ 0 rotational transitions in CH3CN and CD3CN. Measured nitrogen quadrupole coupling strengths are 1eqaaQ(N)=−4224.4 ± 1.5 kHz for CH3CN and eqaaQ(N)=−4229.3 ± 1.5 kHz for CD3CN. The deuterium quadrupole coupling strength along the C–D bond direction is eqzzQ(D)=167.5 ± 4.0 kHz Nitrogen quadrupole coupling is discussed in relation to the electronic structure. Spin‐rotation interaction strengths are reported. A convenient method for calculating matrix elements for hyperfine interactions in an arbitrary coupling scheme is presented.

Brenthia leptocosma is a Microlepidopteron which feeds upon the Boraginaceous bush, Cordia macrostachya. This plant, since its accidental introduction into Mauritius about 1900, has become a pest of considerable agricultural importance. Other food-plants are C. myxa, C. abyssinica and C. holstii, which are all unimportant trees. B. leptocosma has been recorded only from Mauritius. It is not likely to be indigenous for it is restricted to Cordia species, none of which are considered to be native to Mauritius.The morphology and biology of the various stages are described.The distribution of B. leptocosma is that of its food-plants: it is extremely numerous in all regions below about 1,500 feet, which is the upper limit for C. macrostachya. The abundance of the moth is due to the excessive growth of C. macrostachya. Owing to its mode of life, it is of no value as a controlling agent of C. macrostachya.Larval and pupal parasites are recorded.

Predicting the length of time mechanical foam liquids can be held in storage before the liquid deteriorates is difficult. Temperature extremes, oxidation, evaporation, dilution and contamination affect the period of their useful life. A new method of determining thermal degradation of foam liquids indicates that a theoretical relationship between degradation time and temperature may be helpful in estimating storage life of protein-base foam liquids.

An account is given of the biology of the phytophagous Chalcidoid, Eurytoma sp. near howardi D.T., and of its bionomics in Mauritius. The insect was introduced into Mauritius from Trinidad to supplement the activity of the Galerucid beetle, Schematiza cordiae Barber, in the control of Cordia macrostachya, an introduced shrub, indigenous to Central America and the Caribbean Islands. The egg and larval stages are described and figured.The entire development of Eurytoma takes place within the fruit of Cordia, which contains usually only one seed when mature and has a very hard and stony endocarp and a soft and fleshy mesocarp. Oviposition by Eurytoma takes place before the endocarp hardens; the egg is laid inside the seed and the larva feeds on the nucellus and endosperm and later on the developing cotyledons, until the entire seed, except for the seed coat, has been consumed. The attacked fruit continues to grow and its endocarp hardens, but final swelling of the mesocarp does not take place. Although more than one egg may be laid in a seed, only a small percentage of the many seeds dissected contained two mature larvae or two pupae. Pupation takes place within the seed, from which the adult escapes by boring a round hole through the endocarp.Development from egg to adult occupies about 23 days in the hot season (November–April), but in the cooler months (June–September) the fully-grown larva enters a resting period, which may last several months.Adults kept in jars, and provided with honey in water, at a mean temperature of 25°C, lived for an average of 11 days (males) or 20 days (females). A newly emerged female contains about 12 fully developed eggs. Virgin females oviposit readily, all the progeny being male.Releases of adults from material received from Trinidad were made between October 1949 and May 1950; by the latter date it was evident that the insect had become established at the first liberation site and further colonies were established in various parts of the island from material collected there. Estimates of infestation of samples of fruit collected in October 1951 at or near 22 liberation points ranged from 16 to 81 per cent, (mean, 53·7). The latest island-wide estimates, in February, June and October 1953, showed averages of 64·7, 40·8 and 48·7 per cent, infestation, respectively.Infestation of fruits is highest (70–80%) in the hot season, when fruit production is at its maximum, and lowest in the cooler months, when, although the rate of fruiting declines, the life-cycle of Eurytoma is prolonged.Schematiza cordiae had achieved a high degree of control of Cordia before Eurytoma became widely established, and it is difficult to assess the contribution made by the latter, which has no known specific natural enemies in Mauritius; but the two unrelated insects acting jointly are likely to stabilise control more effectively than would one insect alone.In an appendix, P. 0. Wiehe gives notes on the present ecological status of Cordia in Mauritius and contrasts it with that prevailing before the introduction of Schematiza and Eurytoma. He concludes that the secondary succession of vegetation has now reverted to its former course.

Eudorylaimus sundarus n. sp. is described and figured. It is a monodelphic species related to E. monohystera (de Man, 1880).

ONE OUTGROWTH of the quickened interest in education during the last five years has been the active serarch for better means of predicting school achievement. In this quest, personality variables are receiving extensive consideration by several investigators (2,4, 6, 7,11,12). Generally, these efforts have been rewarding either through discov ering a significant correlation between certain per sonality measures and level of achievement or by finding that some combination of personality and ability measures gives a higher correlation with the criterion than does ability test scores alone. Judging from the nature of the relationships so far disclosed between personality traits and achieve ment, one might expect that accurate prediction of achievement is not possible unless a fairly large number of personality test or "factor" (in addition to ability) scores are available for each student. If this is true, then the accumulation and analysis of test data necessary for prediction could conceivably be a forbidding task to many school systems. Un der such circumstances, a more concise means of personality assessment, if equally reliable and valid, would be welcomed. The study reported here represents an attempt by the authors to inves tigate some aspects of the scientific worth of one such method. In spite of the tang of antiquity and the often disappointing results associated with rating tech niques, this method was chosen for study. In a pre vious investigation (13), the senior author found psychiatric ratings of young adults on a personality variable to be fairly reliable under conditions where there was considerable breakdown and ex planation of the rating task. The rating of students by their teachers did not seem to present a prob lem of greater scientific magnitude. In fact, some advantage seemed to exist from the fact of long and close acquaintance usually found in the teacher student situation. To continue with this "telescopic" approach to personality measurement, it seemed necessary to choose a rather broad and familiar trait for rating. In addition to being a "recognizable composite, " it was equally desirable, for the ulterior purposes of this study, that the trait have something to recom mend it as a hypothetical influence on school achievement. While pondering these considerations, the trait of "likability" came to mind. The reality and positive influence of a trait similar to that of "likability" is not hard to docu ment in the experience of most people. A pleasing manner seems to contribute to one's effectiveness whether he be a salesman, minister, teacher, or politician. And, how many remember some fellow student from school days who seemed to please teachers to the point of getting a little extra con sideration, privilege-wise as well as grade-wise? The students who seemed to please teachers and make good grades in high school seemed also to continue to be successful in college. Were these students stupid? No?stupidity is seldom pleasing to anyone. Were they intelligent? Yes?at least average and, perhaps, above average in most cases. Are all intelligent students pleasing or "likable" to teachers? Certainly not.T Maybe in telligence (ability) and "likability" are bothfactors in school achievement, each supplementing the other. The present investigation, conceived as pre liminary to the larger task of methodological vali dation or prediction, was designed primarily to help answer the following questions: 1. To what extent are teachers' ratings of students on the trait of "likability" in agreement? 2. To what extent are these same ratings re lated to student ability and achievement?

A brief historical account is given of the spread of the Eucalyptus Snout Beetle, Gonipterus scutellatus Gyll., fron Australia, its country of origin, and of the utilisation of its natural parasite Anaphoidea nitens Gir. for its control on the African mainland.The discovery of G. scutellatus in Mauritius is described. Its entry was effected between 1935–40, and by 1944 it was threatening Eucalyptus plantations over the whole island.A. nitens was introduced in 1946 from East Africa. Establishment was extremely rapid and two years later G. scutellatus was effectively controlled.Notes are given on the bionomics of both host and parasite under Mauritian conditions.Ecological data are briefly discussed.

The search for a practical, effective extinguishing agent for fires involving water-soluble amines has resulted in the development of a new type of foam. The authors report on tests which confirm the effectiveness of the new extinguishant.

It is shown from a study of 16 GeV/c pp interactions that helicity cannot in general be conserved in the s-channel for pπ+π− systems produced diffractively and with spin-charge ΔJ ⩾ 1. Above a mass of about 1.6 GeV our results are consistent with t-channel helicity conservation.

Extinction parameters of submicron carbon, tungsten and Si particles in hydrogen measured at various temperatures, discussing scattering amplitude functions and Monte Carlo calculations