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The chapter summarizes the physics issues of the demonstration toroidal fusion power plant (Demo) that can be addressed by ITER operation. These include burning plasma specific issues, i.e. energetic particle behaviour and plasma self-heating effects, and a broader class of power-plant scale physics issues that cannot be fully resolved in present experiments. A critical issue for Demo is whether MHD and energetic particle modes driven by fast particles will become unstable and affect plasma performance. Self-heating effects are expected to be especially important for control of steady-state plasmas with internal transport barriers (ITBs) and high bootstrap current fractions. Experimental data from ITER will improve strongly the physics basis of projections to Demo of major plasma parameters such as the energy confinement time, beta and density limits, edge pedestal temperature and density, and thermal loads on in-vessel components caused by ELMs and disruptions. ITER will also serve as a test bed for fusion technology studies, such as power plant plasma diagnostics, heating and current drive systems, plasma facing components, divertor and blanket modules. Finally, ITER is expected to provide benefits for the understanding of burning plasma behaviour in other magnetic confinement schemes.

The 'Progress in the ITER Physics Basis' (PIPB) document is an update of the 'ITER Physics Basis' (IPB), which was published in 1999 [1]. The IPB provided methodologies for projecting the performance of burning plasmas, developed largely through coordinated experimental, modelling and theoretical activities carried out on today's large tokamaks (ITER Physics R&D). In the IPB, projections for ITER (1998 Design) were also presented. The IPB also pointed out some outstanding issues. These issues have been addressed by the Participant Teams of ITER (the European Union, Japan, Russia and the USA), for which International Tokamak Physics Activities (ITPA) provided a forum of scientists, focusing on open issues pointed out in the IPB. The new methodologies of projection and control are applied to ITER, which was redesigned under revised technical objectives. These analyses suggest that the achievement of Q > 10 in the inductive operation is feasible. Further, improved confinement and beta observed with low shear (= high βp = 'hybrid') operation scenarios, if achieved in ITER, could provide attractive scenarios with high Q (> 10), long pulse (>1000 s) operation with beta

Children restrained with lap belts may sustain severe injuries. We investigated the frequency of each type of injury associated with seatbelt contusions. The medical records of all trauma patients with ICD-9 codes for abdominal wall contusions from January 1,1999, to December 31, 2001, were reviewed. All patients with seatbelt contusions were included in the study. Age, seat position, weight, restraint-type, sex, and mechanism of injury were noted. There were 1447 admissions for trauma over the 3-year period. Forty-six patients (ages 4-13) had a seatbelt contusion. Thirty-three wore lap belts, and 13 wore lap and shoulder harnesses. Twenty-two children required abdominal exploration. Small bowel injuries were the most common intra-abdominal injuries. Facial injuries were the most common associated injuries. Forty-eight per cent of children with seatbelt contusions in our institution required surgery. The smaller patients tend to have higher frequency of abdominal injuries. The presence of seatbelt contusion indicates the possibility of severe internal injuries.

Recruitment of tree populations on islands with and without Rattus exulans Peale, and recruitment changes on islands before and after rat eradication are compared using size-class analyses. Seedling establishment in rat-proof exclosures was compared with adjacent control areas. R. exulans depress recruitment of 11 species of coastal trees among 17 species studied: Coprosma macrocarpa, Coprosma repens, Dysoxylum spectabile, Melicytus novae-zelandiae, Nestegis apetala, Pisonia brunoniana, Pittosporum crassifolium, Pouteria costata, Pseudopanax lessonii, Rhopalostylis sapida and Streblus banksii; some to the point of local extinction. Where R. exulans has reached small islands supporting dense colonies of petrels (Procellariidae, Pelecanoididae), the numbers of some plant and animal species have been greatly reduced. Successional pathways in vegetation recovering on larger islands formerly occupied by Maori, have also been altered by this rat. Similar effects by R. exulans on the plant life of Pacific islands are probable considering the length of time R. exulans has been present.

A low-cost method to obtain and analyse digital images of prepared soil sample faces is described. Soil samples are stabilized and pore space is highlighted using a hard-setting resin. The sample faces are photographed using a 35 mm SLR camera fitted with a macro-lens and digital images of the negatives or slides are transferred on to Kodak Photo-CD. The images are analysed using custom-written software on a standard IBM-compatible PC. Various soil structural characteristics are evaluated that have previously required greater resources for evaluation. The method is illustrated with images of three contrasting soil compaction treatments from a field experiment and the results obtained are examined in relation to gas movement measurements.

The ITER Threshold Database, which at present comprises data from nine divertor tokamaks, is described. The main results are presented and discussed. The properties and dependences of the power threshold in individual devices are reviewed. In particular, the analysis shows a rather general linear dependence on magnetic field, but a non-monotonic density dependence that varies from device to device. Investigation of the combined database suggests that the threshold dependence Pthres approximately=0.3neBT2.5 shows reasonable agreement with the data. This expression yields Pthres approximately=150 MW at a density of 0.5*1020 m-3 for ITER. Other expressions with weaker size dependence, and therefore lower threshold power for ITER, are also discussed. Their agreement with the present data is poorer than that of the above expression. In addition, the database is investigated by statistical discriminant analysis. The edge data included at present are described and discussed. Finally, there is a discussion of the implications of the results for ITER

A comparison of conventional, reduced ground pressure and zero traffic systems for grass silage production was made from 1990 to 1993. In 1990, the systems comparison was continued unchanged from that conducted on the same soil and sward from 1986 to 1989. Thereafter, variations were introduced in the treatment and management of the grass (1991, timing of cut) and of the soil (1992 and 1993, slotting). A detailed analysis of soil structure revealed a larger volume and number of macropores in the topsoil of the two novel systems than in the conventional system. The herbage dry matter yields and offtake of nitrogen from the novel systems, between which there was little difference, were significantly larger than from the conventional system. On average, over the 4-yr period, 13% more dry matter and 18% more nitrogen were yielded by the novel traffic systems than by the conventional system. Relationships were identified between the compaction penalties in yield and N-offtake inherent in the conventional system and both soil wetness at preceding harvests and the amount of rainfall after fertilizer application. Cutting the grass for earlier harvests in the zero system did not prejudice superiority in annual yield relative to the conventional system. With the exception of the second harvest in 1 yr (1992), soil slotting did not lead to significant improvements in dry matter yield or nitrogen offtake. The absence of slotting effects on those parameters suggested that grass root growth or function did not benefit from the amount, type or persistence of soil pore space formed by the aerator. Supply of a proportion of the applied nitrogen in the form of slurry did not alter the patterns of yield or nitrogen recovery between or within traffic systems.

In a perennial ryegrass crop, grown for conservation as silage, two novel traffic management systems, zero and reduced ground pressure, were compared with a conventional system over a 4 year period (1986–1989). In the zero system, the grass was managed in traffic-free beds 2.4 m wide using machinery operating on permanently positioned wheeltracks at 2.8 m wheel centres. In the reduced ground pressure system, all equipment was fitted with larger-than-standard, low inflation pressure tyres. Vehicle traffic in the first year created soil compaction in the reduced ground pressure system, and especially, in the conventional system. Measurements of soil bulk density, strength, and water content indicated that poorer soil structural conditions in the conventional system compared with that in the reduced ground pressure system persisted through the four years of the experiment. The soil in the zero traffic beds remained relatively uncompacted compared with the soil in the reduced ground pressure and conventional systems. Herbage dry matter yields were heavier from the novel systems than from the conventional system at eight of the twelve harvests, and 15–16% heavier overall. The largest benefits from the zero and reduced ground pressure systems were gained at first cut in each year. The demonstrated advantages in crop productivity were attributable to enhanced soil aeration and more efficient use of applied nitrogen in the novel systems. A reduced ground pressure traffic system could be adopted readily at a farm scale, using available machinery and tyres. An efficient system for grass silage cropping which fully exploits the advantages of zero traffic requires further machinery developments.

Commercial potato production in the UK requires considerable traffic associated with primary and secondary cultivations and harvesting with consequent problems of topsoil compaction. The extent of these soil and crop effects were examined for a conventional traffic system and for an experimental zero traffic system which was developed from standard machines modified to have all wheels running on permanent wheeltracks at 2.8 m centres. Three rows of potatoes were grown between the wheeltracks, the central row only being traffic-free, as the edge effects of the wheeltracks influenced the outer rows. Results for three seasons showed that the zero system gave mean increases of 14% and 18% in total and marketable potato yields, respectively, as a result of greater soil air-filled porosity in wet seasons and lower soil strength in dry seasons. During harvest, the conventional system produced 30% more soil clods and, after harvest, required a 70% greater draught force for cultivation. Commercial exploitation of the zero system will depend on the development of an economically viable, wide-track machine.

Summary form only given:In November 2006, ministers representing the world's major fusion communities signed the agreement formally establishing the international project ITER. Sited at Cadarache in France, the project involves the European Union, China, India, Japan, the Russian Federation, South Korea and the United States. ITER is a critical step in the development of fusion energy: its role is to confirm the feasibility of exploiting magnetic confinement fusion for the production of energy for peaceful purposes by providing an integrated demonstration of the physics and technology required for a fusion power plant. The ITER tokamak is designed to achieve a fusion amplification factor, Q, of 10 for several hundreds of seconds with a nominal fusion power output of 500MW. It is also intended to allow the study of steady-state plasma operation at Q=5 by means of non- inductive current drive, in anticipation of a requirement for fusion power plants to operate continuously. Accompanying the ITER engineering design activities, an extensive international physics collaboration has addressed the key physics issues for ITER and has assembled a comprehensive physics basis which supports the design. Nevertheless, several key operational aspects remain the subject of focussed R&D activities which aim to ensure the reliable operation of the device at or beyond its design capability. These include control of plasma-wall interactions to ensure that plasma facing components achieve their design lifetime under the stationary and transient loads expected in ITER, the mitigation or stabilization of mhd instabilities to guarantee long duration operation, and the development of candidate steady-state regimes towards ITER-relevant parameters. Operation of ITER will open new frontiers in fusion research involving the influence of a significant a-particle population on plasma heating, confinement properties and stability. Studies in steady-state scenarios will be of particular significance and should provide access to novel aspects of non-linear phenomena in magnetically confined plasmas. To develop plasma scenarios in which high fusion power production is combined with high confinement and plasma pressure, control of heat and particle fluxes, active control of mhd stability and fully non-inductive current drive, the fusion community will need to confront a range of challenges involving plasma physics understanding, plasma measurement techniques, auxiliary heating and current drive systems, and plasma control. The presentation will summarize the current status of the project, discuss key physics issues which are the subject of ongoing R&D, and review the opportunities and challenges involved in successful operation of ITER.

An experimental zero-traffic system was compared with a conventional-traffic system over four seasons in Scotland for both ploughed and direct-drilled winter barley seedbeds. A mouldboard plough was used for primary cultivation in both zero- and conventional-traffic plots in the first season, but a chisel plough was used in the ploughed treatments in subsequent seasons. After mouldboard ploughing in the first season, all wheels of both zero-traffic systems were restricted to permanent wheel tracks and all crops were sown in the bed between them. The crop yield for the ploughed zero-traffic system was never exceeded, although in the second season all yields were similar. Overall mean yield decreased with increasing rainfall in the spring and with decreasing soil permeability to air close to the soil surface. Soil compaction by wheels depressed plant populations under direct drilling in wet autumns, especially below wheel tracks in the direct-drilled conventional traffic system. Compaction also occurred in the absence of traffic under direct drilling. Vertical migration of earthworms was assumed to be responsible for some soil structural improvement at depth and, hence, successful direct drilling for both traffic systems, but after wet seasons crop establishment may also require shallow cultivation prior to drilling. After the fourth harvest, the draught force for primary cultivation averaged 17% more for each conventional-traffic system than for the corresponding zero system.

The semiconductor industry as a whole is growing increasingly concerned about the possible presence of delay-inducing defects. There exist structured test generation and application techniques which can detect them, but there are many practical issues associated with their use. These problems are particularly acute when using low cost test equipment. In this paper, we describe an overall approach for implementing scan-based delay testing with emphasis on low-cost test.

Probabilistic risk assessments (PRAs) have been widely used in nuclear, chemical, petrochemical, and several other industries. The probability and/or frequency results of most PRAs are based on average component unavailabilities during the mission of interest. While these average results are useful, they provide no indication of the significance of the facility's current status when one or more components are known to be out of service. Recently, several interactive computational models have been developed for nuclear power plants to allow the user to specify the plant's status at a particular time and then to receive updated PRA information. As with conventional PRA results, there are uncertainties associated with the numerical updated results. These uncertainties stem from a number of sources, including parameter uncertainty. The paper presents an analysis of the impact of parameter uncertainties on the updated PRA results for nuclear power plants. >

Note: Proc. 19th Symposium on Fusion Technology, Lisbon, Portugal, September 1996, 989 - 992 (1996) Reference CRPP-CONF-1997-066 Record created on 2008-05-13, modified on 2017-05-12

Summary Accurate predictions of the net economic benefits to be gained from the adoption of modifications to vehicles and their running gear are required if compaction problems in commercial crop production are to be overcome. The modifications most readily available to the farmer are: (1) reduction of load on running gear; (2) reduction of ground contact pressure by using wider tires or additional wheels and axles; (3) reduction in the area of fields subjected to traffic, particularly when soils are wet. The likely economic success of these options will depend closely on farm and vehicle size. Apart from the need to quantify, in economic terms, the benefits in crop yield and quality from such changes in management, it is essential to identify and evaluate all primary and secondary costs. Site factors, such as soil type, cultivation system, rainfall, cropping system and farm size, are likely to have a profound influence on the economics of the system. The extrapolation of experimental data obtained on small plots to a farm-scale basis requires great caution, due to the dominant influence of vehicle traffic distribution on overall changes in soil compactness. A number of computer-based models, capable of analysing the whole-farm economic responses to changes in machinery management, have been developed in Canada, the U.S.A. and Sweden. Such models are powerful tools for exploring the multi-factorial interactions between the numerous machinery options and site factors, but there is a shortage of accurate data to verify predictions.

Summary Bulk density and some related terms which quantify soil compactness are defined and discussed. Methods for measuring bulk density are considered in two groups. Direct methods involve the measurement of sample mass and volume, while indirect methods are based on the effect of soil on nuclear radiation. Methods outlined and discussed include core sampling, frame sampling, sand replacement, rubber balloon and clod direct methods and both backscatter and transmission radiation methods. Methods are compared in relation to the selection of a method for a particular purpose. Consideration is given to statistical problems arising from equipment calibration, the number of test samples, and the presence of stones, and to problems associated with the use of gamma radiation. Attention is given to the alternative ways in which test results can be presented. In conclusion, some unresolved problems of bulk density measurement are discussed.

Spectral analysis is applied firstly to an artificial time series to illustrate the technique. This is further exemplified by an analysis of migratory and locomotory behaviour in Teleogryllus commodus . A biological rhythm with a number of harmonics which were not apparent on visual examination of the experimental data, are revealed by the method.

Both ploughed and direct-drilled winter barley seedbeds on a sandy clay loam were compacted by an unladen tractor with all tyre pressures at either the minimum or rather less than half the minimum recommended values. These traffic treatments were applied uniformly across the width of the same plots in each of three seasons. In the first year, when the crop was drilled into the compacted seedbed on ploughed soil only, reduced tyre pressures were shown to result in similar soil cone resistances and vane shear strengths, but noticeably higher values of soil airfilled porosity, plant emergence and yield. In the second and third years, when the compacted seedbeds on ploughed soil were cultivated to 40 mm before sowing, treatment effects on establishment were negligible but compaction below the seedbed was rather less for the reduced pressure treatment and grain yield tended to be higher. Effects on direct-drilled soil were very much smaller or nonexistent. It was concluded that for maximum benefit to be gained from a reduction in tyre pressure the contribution of the carcass stiffness to the mean ground pressure should be low. Although the pressure reductions considered here cannot be recommended for commercial agriculture, the results should be of value to tyre designers, and also show the potential of any device which allows tyre pressure to be altered from the tractor cab.

Modern systems of crop production are tending to increase both the number of passes and the loads carried on the wheels of agricultural vehicles. Therefore, compaction problems may arise, especially in seedbed preparation, spraying and harvesting operations. Because of the difficulty and cost of subsoil cultivation it appears likely that more importance will be attached to the avoidance of subsoil compaction since there is widespread evidence that such compaction may persist for many years even when deep freezing is a regular occurrence in winter. Compaction from wheel traffic has often been found to influence adversely all stages of crop growth, responses being particularly marked in the early phases of establishment. However, in some situations crop responses to compaction are beneficial. In both cases crop responses show marked interaction with weather conditions, particularly water status, during the growing period of the crop. Opportunities exist for reducing the compaction from vehicles. Apart from the combination of field operations to permit fewer wheel passes there would be additional benefits from reductions in load and tyre inflation pressure and by confining some or all traffic to pre-arranged strips for use solely as unplanted wheel tracks (“controlled traffic”). Changes in the demand for traction and in the amounts of applied sprays, amendments and fertilisers may permit a radical departure from current tractor design which could greatly reduce the incidence of compaction problems. The financial disadvantages attributable to the incidence of compaction in crop production are increasingly recognised but quantitative information is rarely sufficient to permit a cost/benefit analysis to be undertaken for those techniques which allow compaction to be avoided rather than ameliorated.

1. The stability of nineteen classes of drugs or their metabolites in urine specimens, for the purpose of toxicological screening has been studied for periods of up to thirty-six weeks. 2. The effect of specimen preservation by refrigation and by the addition of boric acid, chloroform, sodium fluoride, mercuric chloride, and buffers, has been assessed. 3. With the exception of flurazepam, glutethimide, and secobarbital, specimens may be retained at room temperature for periods in excess of six weeks without deterioration. 4. Preservation by the addition of sodium fluoride (5 g/l) followed by freezing, thawing, and filtration significantly prevents specimen deterioration, and may be used as the method of choice.

A penetrometer was devised to allow a rapid empirical assessment of clod strength to be made by measuring the maximum resistance met by a pneumatically driven penetration tool as it passed vertically through the clod. The penetrometer and its operating procedure are described and factors affecting the results obtained from it are investigated. A penetration tool comprising a 60° cone with a base dia of 50 mm, operated at a rate of penetration of 30 mm/s, has been adopted as standard for routine clod strength measurements made in the study of potato harvesting problems. In this form the penetrometer has been used to test more than 16,000 clods.

This paper outlines a four-step approach, that, if followed, will make the results of completed probabilistic risk assessments (PRAs) valuable for prioritizing the NRC's inspection resources so that they have their maximum risk-reduction effect. The paper also describes current work to apply the procedure. The product of the current work will be a computer program that displays important PRA results using decision-oriented, user-friendly personal computer software.

Sheep renin substrate was prepared 28% pure, labelled with 125I and then diluted in concentrated unlabelled sheep substrate. Ten percent of the 125I-label was released as a small fragment on incubation with excess human renin. Adequate separation of the labelled fragment from the parent protein was accomplished with charcoal precipitation or gel filtration. Renin concentration in human plasma was assayed by incubating the 125I-labelled substrate with plasma under zero-order kinetic conditions. Renin was assayed in plasma that had been either acidified or untreated. The acidification procedure was employed to activate inactive renin which accounted for more than half of the total plasma renin concentration. The results of this radiochemical assay correlated closely with the results of bioassay. Specificity of the method was established with antirenin. The assay was sufficiently sensitive to measure suppressed plasma renin levels. The iodinated substrate was stable on storage at -10 degrees C over a six-month period. Because of its high affinity for human renin, ease of purification and stability of the iodinated product, sheep substrate provides a convenient means for routine determination of plasma renin concentration by radiochemical assay.

This is a documentary article describing the Institute's work concerning terramechanics. A brief history of the Soil Section outlines its purpose in relating the characteristics of agricultural machinery, the physical properties of soils and crop growth behaviour. The facilities of the Soil Section are described and its success in developing a high-resolution gamma-ray probe to measure soil bulk density and a recording penetrometer is described. Soil compaction measurements have been carried out for alternatives to the conventional tractor wheel and use of a drop-cone to measure soil plastic limit has been developed. Current efforts are focused on performance measurements of multiple-wheel configurations, four-wheel-drive tractors, consideration of soil compaction under modern crawler tracks and research on the effects on crop yield of soil loosening below normal ploughing depth. Development of prediction models for soil compaction is a major interest.

The extent to which clods are a problem in different areas of the U.K. is summarized and the possible future extent and importance of the clod problem in these areas is discussed. Methods of measuring the size distribution, strength and bulk density of clods are described. The effects of primary and secondary tillage, soil properties, the weather and ridging and spraying operations on the clod populations in potato ridges and on harvester picking belts are detailed. The influence of clods on potato yield, potato damage and harvester design are discussed. It is concluded that clods create a problem in the mechanical harvesting of potatoes on the heavy soils in some areas of the U.K.; that satisfactory methods exist for the measurement of clod physical properties such that clod populations can be compared; that the soil water content at which tillage operations are undertaken can affect the clod population produced at planting, but soil plasticity index dominates any such effect by harvest; that the effect of weather on clod formation and destruction is complex; that wide spacing of potato rows can greatly reduce the generation of clods by ridging and spraying traffic; that although clods contribute much to the complexity of modern harvester design, such machines are not only inefficient at breaking harvested clods but may also damage tubers; and that, despite techniques recently developed to alleviate the clod problem such as clod and stone windrowing, problem soils are less often used for potato production than previously in some areas.

In each of four seasons, zero, one, two, four and six passes of an unladen tractor were applied uniformly over the whole plot area both to ploughed and secondary cultivated and to direct-drilled winter barley seedbeds before sowing on a sandy clay loam. In addition, a one-pass treatment was applied in which tractor-type inflation pressures were reduced to around half the minimum recommended values. A mouldboard plough was used in the first season and a chisel plough replaced it in the final three seasons. After the traffic treatments, the chisel-ploughed soil, but not the mouldboard-ploughed or direct-drilled soils, were cultivated to sowing depth and the crop then sown, grown and harvested without further traffic on all seedbeds. Traffic substantially increased soil strength and bulk density and reduced air-filled porosity in the top 300 mm of soil and reduced permeability to air and gaseous relative diffusivity at seed depth. On direct-drilled soil, because of cumulative effects from season to season and because multiple wheel passes were more effective than on ploughed soil, compaction was, for all traffic treatments except the zero pass, greater than on ploughed soil. Plant populations were severely depressed, especially after more than two wheel passes, when transient waterlogging of ploughed or direct-drilled seedbeds occurred during establishment. Grain yield was markedly reduced by traffic when this resulted in inadequate plant populations or excessive soil strength below sowing depth. Annual variations in traffic effects on plant population and grain yield were related to variation in rainfall. Under-inflation of conventional tractor tyres, when soil conditions were generally critical, gave worthwhile improvements in soil strength and aeration and hence crop establishment and yield, especially on ploughed seedbeds. Although the soil has been classified an unsuitable for direct drilling with conventional traffic because it is readily compacted, direct drilling was satisfactory with zero traffic. During sequential direct drilling with other than zero traffic, yields improved progressively and, after three years, equalled or exceeded those after ploughing, due to improvement in soil structure.

The Probabilistic Safety Information Management System (PRISIM) for Arkansas Nuclear One—Unit 1 (ANO-1) is a personal computer program that allows operations personnel, safety engineers and plant managers to easily access PSA results and related information useful for operational safety management. The PRISIM database contains both pre-processed information that has been obtained from the baseline PSA results and a plant safety model that allows assessment of changes in plant safety caused by changes in plant conditions. This paper cites examples of how PRISIM can be used to make informed decisions about operational problems, design modifications and overall plant safety.

The increase in soil bulk density and cone resistance and the rut geometries produced by a tractor fitted with a “Yieldwheel” on the rear, and each of four alternative front tyres, were measured in a simulated seedbed in an indoor soil tank. The four tyres were a conventional cross-ply, a wide section cross-ply, a wide section radial and a very wide section low pressure tyre. With front-end weights fitted to the tractor and at low draught force, both the radial and low pressure tyres compacted the soil significantly less than did either of the two other tyres. Without front-end weights, there was little difference in seedbed compaction caused by the four tyres. Reduction of the tyre pressures to half their minimum recommended values had no significant effect on either the magnitude or rank order of the soil compaction effects. Rut geometries were always similar for all four wheels because of the overriding effect of the rear wheel.

Inspectors must make many decisions on the allocation of their efforts. To date, these decisions have been made based upon their own judgment and guidance from inspection procedures. The program described in this paper provides PRA information as an additional aid to inspectors. A structured approach for relating PRA information to specific inspection decisions has been developed. The use of PRA information as an aid in optimal decision making (1) in response to the current plant status and (2) in the scheduling of effort over an extended period of time is considered.

This is a longer version, with additional material, of the biography contributed to the Introductory Volume of the new (2nd) edition of the Bibliographic Classification, the first parts of which should appear this year. It goes into Bliss's private as well as his professional life and shows for the first time in print the reasons why he devoted himself first to librarianship, and later to a life of scholarship, particularly to the study of classification and the production of an entirely new general scheme.

Summary Examination of the previously published results of laboratory compression tests on a loam and a sandy loam has shown that as the water content and degree of saturation of a soil increase, the gradient of the virgin compression line, expressed in terms of specific volume and log of spherical pressure, increases and its intercept decreases. The water contents of the soils ranged from 5% to 30% and the degrees of saturation ranged from 10% to 40%. For both soils the gradient of the recompression line for previously compressed soils was shown to decrease with decreasing initial specific volume (increasing density) and to approach zero at a specific volume of 1.5 (dry bulk density of 1750 kg/m3). It was deduced that the position of the critical state line also varies with soil water content and that the critical state theory can be extended to unsaturated soils and therefore be of use in predicting the mechanical behaviour of agricultural soil during cultivation and compaction.

The compaction produced by open, flat-lugged, steel tractor rear wheels, designed at the National Institute of Agricultural Engineering, with lugs at angles of 0°, 30° or 60° to the wheel radius, was compared with the compaction produced by a conventional 13·6-38 rubber tyre in 2 field soils and in an indoor soil tank. Compaction was assessed in terms of wheel rut geometry and changes in soil dry bulk density and cone resistance below the rut centre-line. Compaction produced by the steel wheels was always less than that produced by the tyre and increased with lug angle. It appeared that soil passed up between the lugs, especially those at 0° to the wheel radius, and that subsequent lateral movement of the lugs loosened the soil. Rut depth and changes in soil bulk density in the field soils were dependent on soil type, while changes in cone resistance were independent of soil type. In the field experiments, although the centre-lines of the tracks of the steel wheels did not coincide with the centre-line of the tractor front wheel, the rut produced by the front wheel lay within the width of that produced by the steel wheels. Subsequent tests in a soil tank, where facilities allowed the rear wheels to be tested in the presence and the absence of a front wheel, showed that, although the presence of the front wheel increased the magnitude of the compaction produced, it had no effect on the rank order of the levels of compaction produced by the rear wheels. The ratio of the maximum rut depth to the maximum rut width correlated with the magnitude of the maximum increases in bulk density and cone resistance, but was unrelated to the depths at which the maximum increases occurred.

Summary 1. Oxalic acid is precipitated from urine along with a known addition of sodium oxalate, by an excess of calcium chloride at a pH of 5, and a temperature of 4 degrees. The precipitated calcium oxalate solution is then dissolved in H 2 SO 4 . 2. The calcium content is then determined by comparison with standards by atomic absorption, and by calculation the results are expressed as milligrams oxalic acid dihydrate per 24 h urine volume.

This paper is an expanded version of the second part of my paper on ‘Unco‐operation’ given at the Aslib Annual Conference, 1969, the first part of which, dealing with unco‐operation in general, has already appeared.

The report of the Dainton Committee is the result of the first examination by a Government‐appointed committee of the national libraries. The Committee ‘early took the view that the National Libraries must be seen in relation to … other parts of the national information system’. Its proposals do not touch industrial libraries directly, but only by way of their effects on the national libraries.

The Clark & Evans (1954) and the Thompson (1956) nearest neighbour tests of significance for non-randomness, when applied to spatial distributions of singing crickets, were much less sensitive to deviations from randomness than a goodness of fit test based on Thompson's expression for the probability density function of n th neighbour distances. Probabilities obtained using these three tests were much the same for a synthetic random distribution of positions but generally were markedly different for field distributions of singing crickets. The goodness of fit test takes account of deviations from randomness, irrespective of their direction, over the whole distribution of nearest neighbour distances while the Clark & Evans and the Thompson tests are sensitive to deviations either in the direction of aggregation or the direction of regularity. This undoubtedly results in a loss of their sensitivity when used to detect the non-randomness of some complex distributions. A further advantage of the goodness of fit test is that it shows the direction of deviation when observed and expected class frequencies over the distribution are compared so that spacing trends in the population can be readily gauged. The technique of applying the tests has been discussed. Significant aggregation was established in low and high density populations of crickets using the goodness of fit test.