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Basil Lythgoe was distinguished as an organic chemist. He began his career at the University of Manchester, where he had studied for his undergraduate and PhD degrees, before moving to University of Cambridge. During this period he collaborated with Alexander Todd on the structural elucidation and total synthesis of the natural nucleosides, and was also noted for his investigation of the structure of the natural substance macrozamin. In 1953 he moved to the chair of organic chemistry at the University of Leeds, running a research group from which several graduate students went on to academic careers of the highest distinction. At Leeds he worked on the structure of the alkaloid taxine 1 and calciferol, among other natural substances. Lythgoe's work was characterized by a combination of insight and high experimental skill.

A numerical example for tutorial and possibly design exercise use is described which is concerned with the performance of household waste as a fuel in power generation.

Basil Lythgoe was distinguished as an organic chemist. He began his career at the University of Manchester, where he had studied for his undergraduate and PhD degrees, before moving to University of Cambridge. During this period he collaborated with Alexander Todd on the structural elucidation and total synthesis of the natural nucleosides, and was also noted for his investigation of the structure of the natural substance macrozamin. In 1953 he moved to the chair of organic chemistry at the University of Leeds, running a research group from which several graduate students went on to academic careers of the highest distinction. At Leeds he worked on the structure of the alkaloid taxine 1 and calciferol, among other natural substances. Lythgoe's work was characterized by a combination of insight and high experimental skill.

Crossrail is currently Europe’s largest infrastructure project. The route runs over 100 km from Reading and Heathrow in the west, through new tunnels under central London to Shenfield and Abbey Wood in the east. In addition to the re-configuration and upgrade of surface railway in existing corridors, the scheme consists of the construction of 21 km of twin bored tunnels beneath the heart of London. The Project is the first in the UK to accommodate a combined rail/wheel roughness limit for the purposes of controlling groundborne noise and vibration in overlying buildings from trains operating in the tunnels. The roughness limit is intended to be complied with during the entire operational life of the railway. This paper presents: background on the issues associated with roughness in the wavelength range of interest; the findings of the early work undertaken to identify the risks associated with the limit imposed; roughness data associated with the track designs proposed; and the methods for measuring roughness in the relevant range of wavelengths. This paper has been prepared by the Alstom TSO Costain Joint Venture, the contractor responsible for the system-wide track and fit-out of the central London section of the project, in collaboration with Crossrail Ltd.

A design exercise in chemical engineering is described which is concerned with thermocouples. Physics is the relevant discipline, a point that was made to the students doing the exercise, and accordingly an account of the exercise for the guidance of teachers and lecturers is presented as a contribution to Physics Education.

Honours project work by the second, third and fourth of the above-named authors under the supervision of the first is described. It relates to the energy return on energy invested for two hydrocarbon resources: crude oil and natural gas hydrates. Information obtained from the web has been evaluated and organised into a synthesis which, it is believed, will be of interest both to a specialist in such matters and to a reader seeking an introductory coverage.

A novel piece of apparatus is described which simulates rigorously the ‘infinite slab’ in traditional thermal ignition theory. The apparatus was applied to shavings of a particular type of wood, and the results are shown to be consistent with those from more conventional experiments using basket heating.

Swelling of low rank coals due to solvent contact is measured for a suite of such coals from different sources. The method is a simple one: the pouring of solvent on to samples of the coal in glass tubes and measurements of coal height before and after pouring on the solvent. Correlations between swelling and coal properties are discussed, and for one of the coals a ‘swelling spectrum’, displaying swelling as a function of solvent solubility parameter, is presented.

Greasy wool has a very considerable propensity towards self-heating, and two quantities relevant to such self-heating—activation energy of oxidation and thermal diffusivity—have been measured for four samples of ‘as-received’ greasy wool. For comparison, the same quantities for two cellulosic fibre materials—raw cotton and kapok—are also presented.

Wool colour is not stable and it changes during storage. This study developed wool challenge methods by using a one-week water bath incubation at 40 o C or incubation overnight at a higher temperature to promote colour changes in wool. The study showed that the bacteria present in raw wool play a significant role in colour biodegradation during challenge (storage). A stable wool colour could be obtained for wool specification after a challenge treatment before colour measurement

The oxidation of peat is monitored thermally and the ignition phenomenology investigated. Ignition theory is applied to the results and are an extrapolation made to induce safe stockpiling quantities.

Our recent discovery of hazardous concentrations of arsenic in shallow sedimentary aquifers in Cambodia raises the spectre of future deleterious health impacts on a population that, particularly in non-urban areas, extensively use untreated groundwater as a source of drinking water and, in some instances, as irrigation water. We present here small-scale hazard maps for arsenic in shallow Cambodian groundwaters based on >1000 groundwater samples analysed in the Manchester Analytical Geochemistry Unit and elsewhere. Key indicators for hazardous concentrations of arsenic in Cambodian groundwaters include: (1) well depths greater than 16 m; (2) Holocene host sediments; and (3) proximity to major modern channels of the Mekong (and its distributary the Bassac). However, high-arsenic well waters are also commonly found in wells not exhibiting these key characteristics, notably in some shallower Holocene wells, and in wells drilled into older Quaternary and Neogene sediments.It is emphasized that the maps and tables presented are most useful for identifying current regional trends in groundwater arsenic hazard and that their use for predicting arsenic concentrations in individual wells, for example for the purposes of well switching, is not recommended, particularly because of the lack of sufficient data (especially at depths >80 m) and because, as in Bangladesh and West Bengal, there is considerable heterogeneity of groundwater arsenic concentrations on a scale of metres to hundreds of metres. We have insufficient data at this time to determine unequivocally whether or not arsenic concentrations are increasing in shallow Cambodian groundwaters as a result of groundwater-abstraction activities.

Trains give rise to vibration which propagates through the ground to nearby buildings. At low frequencies (about 4–80 Hz) ‘whole body’ vibration is generated which may be felt, while at higher frequencies (about 30–200 Hz) a rumbling sound is radiated from vibrating walls and floors into the rooms of buildings. Low-frequency vibration is primarily associated with heavy axle-load freight trains running on lines on the ground surface. Structure-borne noise is most often perceptible from trains running in cut-and-cover or bored tunnels where the direct airborne sound of the train is absent at the receiver. For either phenomenon, numerical models for the transmission of vibration through the ground are required to predict the effect of structural alterations to cuttings, embankments and tunnels, or of foundation engineering. To address this, a coupled boundary element/finite element model for vibration propagation has been developed. By restricting analysis to two dimensions, trend analysis can be performed with models that require much lower computing resources than would be required for three dimensions. Here the method is applied to study the effect of design alterations of a bored tunnel and a cut-and-cover tunnel on the transmission of vibration for a frequency range up to 200 Hz.

The noise radiated by railway bridges and viaducts may add to the environmental impact of railways. Statutory requirements for environmental impact assessment of new railway schemes have led to the development of different methods for calculating such noise. A rapid calculation method is presented that is based on a particular form of statistical energy analysis. The method takes account of the origin of the noise, i.e. the relative roughness at the wheel-rail interface, and provides a framework for the calculation of the propagation, dissipation and final radiation of vibrational energy as noise. Validation of the method is provided for a particular form of composite concrete and steel viaduct. The elements of the structure contributing most to the levels of structure-radiated sound under the soffit are identified, along with means for reducing that noise by track and bridge or viaduct design.

The stiffness of the rail pad is a critical parameter in determining the noise from the track. Both theoretical and experimental studies show that a stiff pad, by coupling the rail to the sleeper, leads to a high attenuation of rail vibration with distance along the track and an increase in the sleeper vibration. In this way the rail-radiated component of noise is reduced but the sleeper component is increased. Conversely a soft pad leads to a low sleeper noise component but greater rail noise, as the rail can vibrate over a greater length. In modern track, soft pads are used, as they lead to reduced track forces and less damage to track components such as sleepers. In this paper, measured vibration characteristics of track are presented and compared with predictions. A recent study of the effect of the load dependence of the rail pad and ballast stiffnesses on the dynamic behaviour of the track is extended to give a practical assessment of the effects on the noise radiation. It is shown that, for a typical soft pad with a high load dependence, neglect of the preloading effect would lead to a significant overprediction of the track noise component. It is thus shown that soft pads need not be so disadvantageous for noise as has been suggested.

The paper reports a study of the chemical composition of 25400 grass silages produced in England and Wales, of which 1040 were from the period 1961–63, 17900 (15480 clamped and 2420 baled) were from 1982–88 and 6460 (5640 clamped and 820 baled) were from 1992–93. A sample of each silage had been analysed for dry matter (DM), pH, crude protein (CP) and volatile N and in most cases for ash.The baled silages were drier on average than the clamped silages, with a wider spread of DM contents. The clamped silages with the lowest pH on average were those with a DM content of c. 240 g/kg; clamped silages wetter than this were progressively higher in pH with reduction in DM content; clamped and baled silages drier than 240 g/kg were progressively higher in pH with increase in DM content, up to pH 5·9 in baled silages of 580 g DM/kg. At a given DM content pH was on average 0·6 units higher in baled than in clamped silages. The ash content of baled silages was similar to that of clamped silages. There was an increase in the mean CP content of clamped silages between 1961–63 and 1992–93 and a reduction in the proportion of CP which was volatile. The relationship between DM and volatile N as a proportion of total N was a curve rather than a straight line, with the steepest part of the curve at the lower end of the DM range. The wet silages harvested in 1961–63 were particularly high in volatile N. At a given DM content in the range 170–320 g/kg, volatile N was rather higher in baled than in clamped silages in both 1982–88 and 1992–93. Clamped silages with a DM content of at least 250 g/kg and baled silages with a DM content of at least 310 g/kg were typically well preserved in the sense of having

A suite of brown coals from different sources was examined for solvent-induced swelling in two forms: oven-dried whole coal and pyridine-extraced coal. This enabled the swelling to be resolved into the component due to imbibition of solvent by the crosslinked part and the component due to the non-crosslinked part.

Objective: The purpose of this multicenter, add-on, double-blind, randomized, active-control study was to compare the efficacy and safety of presumably therapeutic (high) vagus nerve stimulation with less (low) stimulation. Background: Chronic intermittent left vagus nerve stimulation has been shown in animal models and in preliminary clinical trials to suppress the occurrence of seizures. Methods: Patients had at least six partial-onset seizures over 30 days involving complex partial or secondarily generalized seizures. Concurrent antiepileptic drugs were unaltered. After a 3-month baseline, patients were surgically implanted with stimulating leads coiled around the left vagus nerve and connected to an infraclavicular subcutaneous programmable pacemaker-like generator. After randomization, device initiation, and a 2-week ramp-up period, patients were assessed for seizure counts and safety over 3 months. The primary efficacy variable was the percentage change in total seizure frequency compared with baseline. Results: Patients receiving high stimulation (94 patients, ages 13 to 54 years) had an average 28% reduction in total seizure frequency compared with a 15% reduction in the low stimulation group (102 patients, ages 15 to 60 year; p = 0.04). The high-stimulation group also had greater improvements on global evaluation scores, as rated by a blinded interviewer and the patient. High stimulation was associated with more voice alteration and dyspnea. No changes in physiologic indicators of gastric, cardiac, or pulmonary functions occurred. Conclusions: Vagus nerve stimulation is an effective and safe adjunctive treatment for patients with refractory partial-onset seizures. It represents the advent of a new, nonpharmacologic treatment for epilepsy.

Mixed-sex blue tilapia Oreochromis aureus fry were produced from indoor spawns in March and April. Fry were stocked in May at an average weight of 0.5 g at 0, 250, 750, or 2,500/ha into ponds which had been stocked previously with three catfish strains at a combined density of 10,000 fingerlings/ha. After a 167-d culture period, from 15 May until 4 November, tilapia stocked at 250 or 750/ha grew to average harvest size approaching 0.45 kg. No significant difference in average size was observed between males and females except at the 2,500 tilapia/ha stocking density. Sixty percent of the tilapia polyculture ponds yielded no reproduction at harvest and maximum reproduction observed was 13.5 kg/ha. Lack of reproduction and the undeveloped state of sampled female ovaries indicated that most females had yet to attain sexual maturity. Catfish production and catfish feed conversion was not significantly different between tilapia polyculture and catfish monoculture ponds (P > 0.05). First seine hauls yielded over 88% of the total catfish harvest, but only an average of 3.9% of the marketable tilapia. Tilapia had no measurable impact on the incidence of catfish off-flavor at any of three sample intervals. Overall average levels of TAN and nitrites did not differ significantly between treatments; however, mean chlorophyll a concentration was significantly higher (P > 0.05) in the 2,500 tilapia/ha treatment than at lower tilapia densities.

We tested an airlift-operated floating raceway in which fry of channel catfish (Ictalurus punctatus) were raised from swim-up stage to 5 cm total length (TL) before stocking into rearing ponds. Survival of fry raised in this manner was compared with that of swim-up fry stocked directly into rearing ponds. Swim-up fry stocked into two 1.87-m3 floating raceways at a density of 21,390 fry/m3 (40,000 fry/raceway) grew to 5 cm TL within 27 d and had an average survival of 90.3%. When these fry were subsequently stocked into two 0.2-ha ponds for further rearing, 95.2% survived to 12.5-cm fingerling size. Overall, survival from swim-up stage averaged 86.1%. Survival in ponds stocked with swim-up fry averaged 84.1%. Unaccounted fish losses during the pond-rearing phase were lower in ponds stocked with raceway-reared fry than in ponds stocked with swim-up fry (4.1% versus 14.7%, respectively). Although overall survival of raceway-reared and pond-reared groups was similar, the floating raceway system offer...

Poor diabetic control was found in nearly 50% of adolescents attending two paediatric clinics. Adolescents with well and poorly controlled diabetes differed in reported parental involvement in their diabetic regime. There was little association between glycaemic control and family functioning using the McMaster Family Assessment Device (FAD) whether rated by adolescent or a parent. Neither did sufferers with diabetes differ from families of matched community controls according to the FAD overall though the families of well controlled diabetics were more likely than the other two groups to score themselves in the unhealthy range on the subscale of global functioning.

Measurements of ground vibration induced by a two-car EMU railway vehicle have been made at speeds up to 250 km/h. The results show an increasing ground vibration level with increasing speed and a clear excitation generated by each passing wheelset and the discrete sleeper support. Simulations with a multibody vehicle model on a railway track, including a ground model consisting of isotropic elastic layers, show good agreement with the measurement results.

Methanol is an attractive alternative fuel based on its engine performance and emission characteristics. Methanol can be synthesized from biomass or urban waste, and as a result, it does not contribute to the net addition of carbon dioxide to the atmosphere. Cold-starting of methanol-fueled engines is difficult at temperatures below 10°C, and at sub-zero temperatures, starting may be impractical without significant engine modifications. In this research, an attempt has been made to study and prevent the cold-starting problem by using hydrogen and carbon monoxide gas mixture produced by decomposing liquid methanol using a submerged electric arc device. The electric arc has the advantage of instantaneous gas production and the experimental data relating to the performance of the device and its design are reported. The device is capable of producing up to 0.01 cu m (10 L) per min of a gas which is primarily carbon monoxide and hydrogen with a thermal efficiency of 18 percent relative to the theoretical energy requirements for methanol decomposition. The feasibility of using this arc device is analyzed based on the simulated cold-starting data collected for a single-cylinder Kawasaki engine at −20°C.

The phase diagram of a mixture of the discogens triphenylene hexa-n-heptanoate (HET7) and triphenylene hexa-(2-methyl-4-n-decyloxy)benzoate is presented. This mixture provides a more accessible nematic temperature range than was previously possible. The refractive indices of one mixture composition are measured and a rather small, negative birefringence found. The two-parameter Haller extrapolation method is used to calculate the molecular polarizability ratio Δα/α. This has a rather small magnitude compared with calamitic mesogens, although the individual polarizabilities are much larger, due to the greater molecular mass of these compounds. The calculated value of Δα/α is used to give the uniaxial orientational order parameter S, whose value is comparable to those of calamitic examples. Tabulated bond polarizability data are used to predict a value for Δα/α, which is found to be similar to the experimental result.

Vibration from trains can cause annoyance and also concern about possible damage to property. It is a major issue in the environmental impact assessment of new railways and where new traffk is to be added on existing railways. Track designed to control vibration has been implemented on a number ofrailare effective for ways. These designs vibration at frequencies at the L w end of o the audible range. Such vibration causes re-radiated noise in buildings and is especially associated with trains in tunnels

Centrifuge crystal growth experiments under 2–6 gravity have produced crystals with microstructure indicative of diffusion controlled growth. A current hypothesis for this phenomenon is that Coriolis and gravity gradient forces produced by the centrifugal motion can effectively damp convective flows. Our research has included the study of solidification during KC-135 aircraft parabolic maneuvers which produce alternate periods of 25 s low gravity and 45 s of high (1.8 g 0 ) gravity. We, thus, examined the question of how the Coriolis and gravity gradient forces during high gravity maneuvers compare to that for common centrifuges. Microstructural examination of samples solidified during high gravity arcs has revealed no evidence of convection dampening. As a first approximation, we model the high gravity arc as a centrifuge with radius of 20,480 ft and angular speed of 0.318 rpm. Scaling analysis indicates that the Coriolis and gravity gradient expected on the aircraft high gravity arc are less than that for the centrifuges by a factor of 100. Detailed Navier-Stokes analysis of the fluid flow and thermal fields during solidification of aluminum and Cd-Te in KC-135 high gravity show that convective flows of about 1 mm/s are induced. The thermal field, however, is only slightly modified by the convection. Coriolis and gravity gradient during solidification in KC-135 high gravity arcs, even at accelerations that have been shown to produce significant convective flow dampening in some centrifuge sytems, are shown to have no significant influence on the melt thermal and flow fields. The KC-135 high gravity arc could, thus, be advantageously utilized for experiments where separation of centrifugal acceleration and Coriolis acceleration is desirable.

The fluid mechanics associated with crystal growth processes on centrifuges is modeled using 2D and 3D models. Two-dimensional calculations show that flow bifurcations exist in such crystal growth configurations where the ampoule is oriented in the same direction as the resultant gravity vector and a temperature gradient is imposed on the melt. A scaling analysis is formulated to predict the flow transition point from the natural convection dominated regime to the Coriolis force dominated regime. Results of 3D calculations are presented for two thermal configurations of the crystal growth cell: top heated and bottom heated with respect to the centrifugal acceleration. In the top heated configuration, a substantial reduction in the convection intensity within the melt can be attained by centrifuge operations, and close to steady diffusion-limited thermal conditions can be achieved over a narrow range of the imposed microgravity level. In the bottom heated configuration the Coriolis force has a stabilizing effect on fluid motion by delaying the onset of unsteady convection.

Despite the large personal and economic losses associated with the effects of falling and slipping, the etiology of falling and slipping behaviour is unknown. A major inhibition of past research has been the lack of a facility to experimentally investigate such behavior without exposing human subjects to the natural danger of injury resulting from falls. To carry out this research, a facility was constructed to investigate falling and slipping behavior. One component of this facility, a fall arresting robot, is used to experimentally research the basic mechanics involved in falls. Specifically, this robot was designed to provide passive, reactive support of a test subject, so that a reduced friction walk surface could be used to induce a fall. This fall arresting robot (FAR) is composed of two subsystems. The mechanical components are combined to provide an overhead suspension system which can be made to track a predetermined path in anticipation of arresting an induced fall. The second subsystem is an automatic control system that provides passive tracking of the test subject's movement along the path. This paper describes the design and development of the fall arresting robot and how the components are combined to provide a functional fall arresting system.

Despite the large personal and economic losses associated with the effects of falling and slipping, the etiology of falling and slipping behavior (FSB) is unknown. A major inhibition of past research has been the lack of a facility to experimentally investigate such behavior without exposing human subjects to the natural danger of injury resulting from falls. To carry out this research, a facility was constructed to investigate FSB. One component of this facility, a fall arresting system, will be used to experimentally research the basic mechanisms involved in falls. Specifically, this component must be designed to provide passive, reactive support of a person so that a reduced friction walk surface and/or a fall can be induced. This fall arresting system is composed of two subsystems. In the first, the mechanical components are combined to provide an overhead suspension system that can be made to track a predetermined path in anticipation of arresting an induced fall. The second subsystem is an automatic control system that provides passive tracking of the test subject's movement along the path. This paper describes the development of the overall system and how the components are combined to provide a functional fall-arresting system.

The swelling of a low-rank coal under the influence of various solvents is examined and results compared with those for a similar coal in briquetted form. Results are interpreted in terms of the effects of briquetting on pore structure.

Proton exchange membrane (PEM) fuel cells have the possibility of becoming the primary power source of hybrid electric vehicles. However, a fuel cell system is large, complex and expensive. Designing and building new prototypes is difficult and expensive. The alternative is to examine different systems through simulations. This paper describes a mathematical model of the fuel cell and its use to develop the auxiliary systems necessary to apply the fuel cell in an HEV. The popular simulation program Matlab and Simulink are used the model development.