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WHILE an aircraft is in flight, the landing gear is a liability which, by virtue of its weight and size, and demands upon power supplies, reduces the efficiency of the aircraft. However, at two of the most critical and dangerous parts of the sortie, namely take‐off and landing, the safety of the aircraft depends to a very great extent upon the landing gear working effectively. Even V.T.O.L. aircraft do not seem to be able to dispense with landing gear. In fact, with an increasing emphasis on S.T.O.L. aircraft, and the use of rough airfields, the demands on landing gear seem to be increasing. The landing gear designer is still, therefore, faced with the problem of providing equipment of minimum size and weight, to meet a specification which, in some parts, is not very well defined. In common with other members of the aerospace industry, he is constantly seeking methods of improving his product.

IT is surprising to find, in the modern aircraft industry, a technical service that has developed in a short time from informal experiments with materials and techniques, carried out by a few individuals.

Purpose – The chapter reviews, compares and contrasts the experiences of two neighbouring universities, the University of Bristol and the University of the West of England, in the introduction, pursuit and institutional embedding of widening participation (WP) policies and programmes.

Methodology/approach – Comparative analysis of, and commentary on, the historical and ongoing experiences of the two universities' WP activities.

Findings – Contextual differences in the missions and roles played by the two universities inevitably mean their experiences have different underlying logics, but in terms of the practical drivers at work and outcomes more subtle similarities are also evident.

Practical implications – Making direct comparisons between the parallel experiences of universities sharing a common geographical setting can be illuminating, as can examples of their joint working and collaboration. Other neighbouring universities could follow suit.

Social implications – The ‘takes’ on WP by different universities inevitably reflect the types of institutions they are and aim to be, but successful WP practices and policy embedding is not the prerogative of any particular university type.

Originality/value of paper – The direct inter-university comparison of WP policy offered here is rare within the literature.

DEAR SIR, I should like to add one or two points to the series of articles by Mr. Bielkowicz entitled “Evolution of Energy in Jet and Rocket Propulsion”. With reference to Tables I and III (March) mention is not made of the importance of the mixture density in choosing a rocket fuel. Although specific impulse is a major factor most rockets are designed for high speed flight involving large losses due to drag, and, as the fuel of a rocket is usually a large percentage of the total mass, it is important to use a fuel mixture with as high a density as possible. A convenient method of determining the relative merits of various fuel mixtures is by means of the “density impulse”. This is a figure obtained by multiplying the specific impulse by the relative density of the fuel mixture, this giving a measure of the impulse per unit volume. In Tables I and II are given the specific impulses, densities and density impulses for the fuels examined in the first article (Tables I and III).

In a boundary layer ingestion (BLI) propulsion system, the fan operates continuously under distorted inflow conditions, leading to an increment of aerodynamic loss and in turn impacting the potential fuel burn reduction of the aircraft. Usually, in the preliminary design stage of a BLI propulsion system, it is essential to assess the impact of fuselage boundary layer fluids on fan aerodynamic performances under various flight conditions. However, the hub region flow loss is one of the major loss sources in a fan and would greatly influence the fan performances. Moreover, the inflow distortion also results in a complex and highly nonlinear mapping relation between loss and local physical parameters. It will diminish the prediction accuracy of the commonly used low-fidelity computational approaches which often incorporate traditional physics-based loss models, reducing the reliability of these approaches in evaluating fan performances. Meanwhile, the high-fidelity full-annulus unsteady Reynolds-averaged Navier–Stokes (URANS) approach, even though it can give rather accurate loss predictions, is extremely time-consuming. This study aims to develop a fast and accurate hub loss prediction method for a BLI fan under distorted inflow conditions.

This paper develops a data-driven hub loss prediction method for a BLI fan under distorted inflows. To improve the prediction accuracy and applicability, physical understandings of hub flow features are integrated into the modeling process. Then, the key physical parameters related to flow loss are screened by conducting a sensitivity analysis of influencing parameters. Next, a quasi-steady assumption of flow is made to generate a training sample database, reducing the computational time by acquiring one single sample from the highly time-consuming full-annulus URANS approach to a cost-efficient single-blade-passage approach. Finally, a radial basis function neural network is used to establish a surrogate model that correlates the input parameters and the output loss.

The data-driven hub loss model shows higher prediction accuracy than the traditional physics-based loss models. It can accurately capture the circumferentially and radially nonuniform variation trends of the losses and the associated absolute magnitudes in a BLI fan under different blade load, inlet distortion intensity and rotating speed conditions. Compared with the high-fidelity full-annulus URANS results, the averaged relative prediction errors of the data-driven hub loss model are kept less than 10%.

The originality of this paper lies in developing a new method for predicting flow loss in a BLI fan rotor blade hub region. This method offers higher prediction accuracy than the traditional loss models and lower computational time cost than the full-annulus URANS approach, which could realize fast evaluations of fan aerodynamic performances and provide technical support for designing high-performance BLI fans.

We have observed in the reports of those engaged in the administration of the Acts several references to the practice of milking so that a portion of the milk is left in the udder of the cow, this portion being removed subsequently and not included in the milk sent out to customers. The inspector for the southern division of the county of Northampton reports that on a sample of milk being found deficient in fat to the extent of 17 per cent., a further sample was taken at the time of milking when a milkman was found to be not properly “stripping” the cows. He was warned. The analyst for the county of Notts writes: “The first strippings obtained before the milk glands have been normally excited by the milking are very low in fat yet are “genuine” milk in the sense that nothing has been added to or taken from it. It is nonsense to talk of genuine milk in the sense that everything that comes from the udder of the cow is to be taken as genuine milk fit for sale.” In a case tried before the Recorder of Middlesbrough, one witness said that among some farmers it was a common practice not to “strip” cows until after the milk was sent away.

The Equal Pay Act 1970 (which came into operation on 29 December 1975) provides for an “equality clause” to be written into all contracts of employment. S.1(2) (a) of the 1970 Act (which has been amended by the Sex Discrimination Act 1975) provides:

October 24, 1969 Factory — Statutory duty — Dangerous machinery — Dangerous combination of machinery and material — Danger arising from “nip” between moving work‐piece and stationary bar — Automatic cooling device — Danger arising from coolant applied by hand — Practice known to employers — Whether foreseeable — Whether duty to fence — Factories Act, 1961 (9 & 10 Eliz. II, c. 34), s. 14(1).

Sorting is a very important algorithm to solve problems in computer science. The most well-known divide and conquer sorting algorithm is quicksort. It starts with dividing the data into subarrays and finally sorting them.

In this paper, the algorithm named Dual Parallel Partition Sorting (DPPSort) is analyzed and optimized. It consists of a partitioning algorithm named Dual Parallel Partition (DPPartition). The DPPartition is analyzed and optimized in this paper and sorted with standard sorting functions named qsort and STLSort which are quicksort, and introsort algorithms, respectively. This algorithm is run on any shared memory/multicore systems. OpenMP library which supports multiprocessing programming is developed to be compatible with C/C++ standard library function. The authors’ algorithm recursively divides an unsorted array into two halves equally in parallel with Lomuto's partitioning and merge without compare-and-swap instructions. Then, qsort/STLSort is executed in parallel while the subarray is smaller than the sorting cutoff.

In the authors’ experiments, the 4-core Intel i7-6770 with Ubuntu Linux system is implemented. DPPSort is faster than qsort and STLSort up to 6.82× and 5.88× on Uint64 random distributions, respectively.

The authors can improve the performance of the parallel sorting algorithm by reducing the compare-and-swap instructions in the algorithm. This concept can be used to develop related problems to increase speedup of algorithms.