25,548 research outputs found
The buckling and collapse behaviour of saddle-supported cylinders - Keynote Lecture
Recent work by the present authors on the collapse conditions for horizontal cylindrical saddle supported storage vessels is described and reviewed. Attention is directed to a range of geometries, typically R/t < 200, where plastic collapse type failure may be relevant. A series of forty tests on end-supported model cylinders loaded centrally by a rigid saddle were performed and a variety of theoretical methods were used for comparison with the test results. It was found that the best agreement was obtained by using an elasticplastic finite element analysis approach. The results of a parametric survey based on the elastic-plastic finite element method are summarised. The paper reports some validation checks, which have been performed to support the parametric results
Parametric plastic collapse loads and their validation for horizontal saddle supported storage vessels
In general, progressive plastic collapse occurs in vessels with low values of R/t ratio, typically less than 200, and elastic-plastic buckling is observed in vessels with higher R/t ratios. The aim of this paper is to examine various theoretical analyses for plastic collapse loads, applicable to vessels with low values of R/t ratio, and compare these with the experimental results obtained by the authors and others
Railway Reform in China.
The purpose of this working paper is to consider the current situation of Chinese Railways, the progress of reforms to date, and possible future developments. The first section describes the current problems of Chinese Railways, as a vast organisation subject to strong central control, facing enormous and rapidly growing demands which it is unable to satisfy. The progress of reform in Chinese Railways to date, and in particular the Economic Contract Responsibility System instituted in the late 1980's and the development of joint venture companies to build new lines, are then described. In the following section the key reform models found in other countries - deregulation and privatisation of vertically integrated regional companies; separation of infrastructure from operations with open access andlor franchising competitors; or reorganisation on the basis of business sectors - are then described. None is fully suitable for China, but it is suggested that a combination of sectorisation, more commercial independence, further development of joint public/private partnerships and more contracting out, is the most likely way forward
Sound-suppressing structure with thermal relief
Sound-suppressing structure comprising stacked acoustic panels wherein the inner high frequency panel is mounted for thermal expansion with respect to the outer low frequency panel is discussed. Slip joints eliminate the potential for thermal stresses, and a thermal expansion gap between the panels provides for additional relative thermal growth while reducing heat convection into the low frequency panel
Effects of local reinforcement on nozzles in dished ends
The results of a parametric design study, to determine the optimum diameter of reinforcing pad for nozzles in the knuckle region of an ellipsoidal pressure vessel head are presented herein. The study utilised a linear elastic finite element model, created using ANSYS finite element analysis software. Nozzle parameters of diameter, offset, and wall thickness were varied to ensure the results obtained were achieved through a thorough analysis. Optimum pad sizes were obtained for thrust, in plane moment and out-of-plane moment nozzle loads. Design curves were produced, allowing maximum permitted applied stress, to be calculated for any nozzle size subject to one of the three loading conditions. Recommendations for allowable offset and treatment of loading combinations are also presented
Improved pH buffering agent for sodium hypochlorite
Sodium citrate/citric acid was found to be an effective buffer for pH control when used with sodium hypochlorite. The mixture does not corrode aluminum. The buffer appears to form a type of conversion coating that may provide corrosion-resistant properties to aluminum in other applications
Analysis and Optimization of Deep Counterfactual Value Networks
Recently a strong poker-playing algorithm called DeepStack was published,
which is able to find an approximate Nash equilibrium during gameplay by using
heuristic values of future states predicted by deep neural networks. This paper
analyzes new ways of encoding the inputs and outputs of DeepStack's deep
counterfactual value networks based on traditional abstraction techniques, as
well as an unabstracted encoding, which was able to increase the network's
accuracy.Comment: Long version of publication appearing at KI 2018: The 41st German
Conference on Artificial Intelligence
(http://dx.doi.org/10.1007/978-3-030-00111-7_26). Corrected typo in titl
On the plastic collapse of horizontal saddle supported storage vessels
The present paper summarises a comprehensive programme of work on collapse loads of horizontal cylindrical saddle supported storage vessels. A programme of tests was conducted on 40 model vessels that included both welded and loose saddles. Different collapse behaviours were observed depending largely on the radius to thickness ratio of the vessels. A range of theoretical approaches were explored and compared with the experimental results. The best theoretical comparison was then used to conduct a parametric survey covering a total of 218 cases. The results of the survey have been presented in the form of simple design graphs
Recipes for PIE: An Exploration of Psychologically Informed Environments (PIE) in Homelessness Services
Aims: Psychologically informed environments (PIE) is a broad and flexible framework developed in UK homelessness services. PIE integrates psychologically informed ideas and approaches into service design to consider the psychological and emotional needs of service-users and staff. This study aimed to explore how psychological professionals interpret and implement PIE and what this looks like in practice.
Methodology: Semi-structured interviews were conducted with 11 practitioner psychologists who use a PIE approach in homelessness services or organisations. Reflexive thematic analysis was used to explore how PIE is applied in practice.
Results: Five themes were identified through the thematic analysis: (1) āPIE is a journey, not a destinationā which describes how practitioner psychologists deciphered and implemented PIE over time. (2) āBuilding trusting relationshipsā which describes the importance and process of building trust with people experiencing homelessness and with colleagues. (3) āSystemic barriers to PIEā which describes systemic, structural, and societal barriers to the implementation of PIE. (4) āReluctance from staff teamsā which describes some staff teamsā discomfort with reflective practice sessions and the judgemental attitudes held towards service-users, and (5) āThe enormity of PIEā which describes PIE as a vast framework which can be utilised by professionals and services irrespective of formal psychological training and is challenging for a single staff member to hold and manage in their day-to-day workload.
Conclusions: This research explored the accounts of practitioner psychologists using PIE in homelessness services. The time required to decipher and implement PIE should be acknowledged by senior leaders, commissioners, and psychological professionals. Building trusting relationships with both service-users and other staff is a cornerstone of PIE and should be emphasised. Consideration should be given to policies and initiatives to reduce systemic limitations, engage staff teams, and share the responsibility of implementing PIE
Application of solar energy to air conditioning systems
The results of a survey of solar energy system applications of air conditioning are summarized. Techniques discussed are both solar powered (absorption cycle and the heat engine/Rankine cycle) and solar related (heat pump). Brief descriptions of the physical implications of various air conditioning techniques, discussions of status, proposed technological improvements, methods of utilization and simulation models are presented, along with an extensive bibliography of related literature
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