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Probably the most interesting public library discussion of last month occurred in the Holborn Borough Council on April 12th. At this meeting the Library Committee reported that they had considered what further economies could be effected during the war in connexion with the Local Government Board circular. They found that no substantial saving could be made by suspending the issue of fiction. On the other hand, the four remaining assistants were either attested, or single men who would be required for military service. In these circumstances they recommended, “That, for the period of the war, or until further order, the Holborn Public Library be closed to the public.” This subject was referred to the Law and Parliamentary Committee, which submitted a report. This report seems to us to be so logical and important in its arguments and decisions that we are giving it a place in these editorial columns, as we believe it will be of value not only to London librarians but to others throughout the country, who are faced with similar issues :—

In the United Kingdom the special library, in the modern connotation, developed in a world where public libraries were mature, well‐established and vigorous. In India, however, the special library for the most part has preceded the development of the public library system.

Lawrence Clark Powell's words describe the premise of this article:

The communication concerning situations of project marketing (space industry, train construction, engineering, building construction, …) does not lead to a lot of researches and publications. An attempt will be made in this article, to establish the link between project and corporate communication considering the various steps in the development of a particular project strategy. This induces the development of the identity of the firm, the definition of the main targets (sociogram approach) and the development of particular tools at both an internal and an external level. It appeared in this study that the traditional communication mix arrives late after the management communication and the organizational communication. Concerning the tools, the relational network seems to be the best adapted to the particular situation and the targeting allows a good despatching of the resources at this level. The firms have in fact to develop both a functional and a relational positioning.

The purpose of this paper is to construct a numerical model for the numerical analysis of the hydraulic transient profile in Trabalhador channel for filling and emptying maneuvers and to determine the water level in time. Model results support operational managers in the decision-making process.

Physical data were provided for the construction and calibration of the numerical model. The equations of Saint-Venant were approximated by a finite difference scheme and the numerical model was written in Fortran. The results of filling and emptying of the channel simulations were compared with the measured water levels.

Measured water levels and those simulated by the numerical model have shown good correlation. The time recorded for the filling and emptying of the canal was also close between the measured and simulated data. The simulation design flow pointed to inundation in the channel banks. Simulation water levels were slightly higher than those measured.

In this model, the combination of canals and pressure conduits was not considered.

The findings confirm the measured time for filling and emptying of the canal, as well as inundation of canal banks for the maximum design flow. These results help in the management process.

This paper presents a numerical model for hydraulic transient analysis in channels with good agreement with the field data.

The unstable dynamic propagation of multistage hydrofracturing fractures leads to uneven development of the fracture network and research on the mechanism controlling this phenomenon indicates that the stress shadow effects around the fractures are the main mechanism causing this behaviour. Further studies and simulations of the stress shadow effects are necessary to understand the controlling mechanism and evaluate the fracturing effect.

In the process of stress-dependent unstable dynamic propagation of fractures, there are both continuous stress fields and discontinuous fractures; therefore, in order to study the stress-dependent unstable dynamic propagation of multistage fracture networks, a series of continuum-discontinuum numerical methods and models are reviewed, including the well-developed extended finite element method, displacement discontinuity method, boundary element method and finite element-discrete element method.

The superposition of the surrounding stress field during fracture propagation causes different degrees of stress shadow effects between fractures and the main controlling factors of stress shadow effects are fracture initiation sequence, perforation cluster spacing and well spacing. The perforation cluster spacing varies with the initiation sequence, resulting in different stress shadow effects between fractures; for example, the smaller the perforation cluster spacing and well spacing are, the stronger the stress shadow effects are and the more seriously the fracture propagation inhibition arises. Moreover, as the spacing of perforation clusters and well spacing increases, the stress shadow effects decrease and the fracture propagation follows an almost straight pattern. In addition, the computed results of the dynamic distribution of stress-dependent unstable dynamic propagation of fractures under different stress fields are summarised.

A state-of-art review of stress shadow effects and continuum-discontinuum methods for stress-dependent unstable dynamic propagation of multiple hydraulic fractures are well summarized and analysed. This paper can provide a reference for those engaged in the research of unstable dynamic propagation of multiple hydraulic structures and have a comprehensive grasp of the research in this field.

Pressure pulsations and vibration working condition lead to dynamic troubles in hydraulic devices. It is highly desirable to be able to estimate the durability at the design stage so that appropriate maintenance period can be determined for safety and reliability. The purpose of this paper is to propose a quantitative evaluation method for pulsation and vibration based on reliability.

Pressure pulsations are approximately treaded as a stationary random process. The principle of transform function and fluid network chain rules are used to disassemble the hydraulic power unit into the series‐system. Mean square deviation of dynamic stress under the pumping source white noise exciting was calculated based on frequency responses. Statistical regularity of displacement and stress responses of pipelines under external random vibration are obtained by the spectrum analysis. Both the first‐passage failure criterion and fatigue damage accumulation failure criterion are adopted to analyze the dynamic pressure reliability of hydraulic pipelines.

The terminal joint, bellow pipe and pipe clamps are verified as the weak location of the pipelines. The mean square deviations of pulsations and vibration response influence the pipelines reliability. The results indicated that the preventative design method of controlling the pressure below 10 per cent of rated pressure does not meet the security specification of the hydraulic power unit.

The paper proposes a quantitative evaluation method for random pressure pulsation and external vibration based on reliability, which provides a new approach for the safety assessment and design of hydraulic pipelines.