Políticas educacionais: implementação ou atuação?

Nesse texto apresentamos a resenha da obra: BALL, S. J.; MAGUIRE, M.; BRAUN, A. Como as escolas fazem as políticas: atuação em escolas secundárias. Tradução Janete Bridon. Ponta Grossa: Ed. UEPG, 2016. 220 p

Mooring systems for marine energy converters

This is the author accepted manuscript. The final version is available from IEEE via the DOI in this record.This paper discusses several new technologies for mooring floating marine energy converter (MEC) devices, such as wave energy generators, tidal current turbines and floating wind turbines. The principal mooring component is a special nylon fiber rope which provides cyclic tension fatigue endurance much superior to that of conventional nylon ropes. The nylon fiber is treated with a new proprietary coating which has excellent wet yarn abrasion properties. The parallel-subrope type rope construction further reduces internal abrasion. Extensive laboratory testing was carried out on this new nylon rope design. Cyclic tension fatigue tests were conducted at mean loads and load amplitudes typical of actual service conditions and at higher mean loads and amplitudes. These tests demonstrate that the special nylon rope has essentially the same, desirable stretch characteristics as conventional nylon rope and has much better endurance performance. The mooring connection to the floating MEC device consists of a high-modulus fiber rope pendant which passes through a low-friction bell-mouth nylon fairlead on the MEC device. This eliminates the use of heavy, unreliable chain in this critical connection. A unique bag anchor system would be used on sand, clay, rock and other sea beds in which conventional drag embedment anchors and driven piles are impractical. The bag anchor consists of a large abrasion resistant carcass with lifting straps and top closure. The bag is transported to site in a collapsed form and is filled with local sand or aggregate to provide ballast weight. Several or many such bags are enclosed within a fiber rope net for deployment and are grouped together for connection to the mooring line. The paper will be of particular interest to designers of moorings for MEC systems in shallow water and severe wave environments. It will also be of interest for other mooring applications.This work would not have been possible without the funding and support of the Scottish Government, the Carbon Trust and Innovate UK.   The project was funded under the Marine Renewables Commercialization Fund (MRCF) and Marine Energy Supporting Array Technologies (MESAT).   Other partners who contributed to this project include Lloyd’s Register, DNV‐GL, TenCate, Orion Energy Centre, Nylacast, and offshore wind developer IDEOL.    Input and encouragement was provided by tidal power developer partner Bluewater, and wave energy developers AWS Ocean Energy and Pelamis.

Considering Cable Stretch in Logging Applications

This paper considers three methods for calculating the un-stretched length of a cable with significant self weight when the final static equilibrium conditions are known. The first method uses an average line tension and Hooke’s Law to estimate the un-stretched length. The second method uses a Lagrangian co-ordinate and Hooke’s Law to form an exact equation for the un-stretched length, given the assumption that the cable is linear elastic and the change in length is due to elastic stretch. The third method uses a Lagrangian coordinate; however, construction stretch is included in addition to elastic stretch. The results of this paper indicate the average tension is a suitable surrogate for a tension function that is a function of position when considering elongation to be the result of elastic stretch. When construction stretch is considered, the average tension method also performed well for cables with tensions less than one-third the minimum breaking strength

An assessment of the strength of knots and splices used as eye terminations in a sailing environment

Research into knots, splices and other methods of forming an eye termination has been limited, despite the fact that they are essential and strongly affect the performance of a rope. The aim of this study was to carry out a comprehensive initial assessment of the breaking strength of eye terminations commonly used in a sailing environment, thereby providing direction for further work in the field. Supports for use in a regular tensile testing machine were specially developed to allow individual testing of each sample and a realistic spread of statistical data to be obtained. Over 180 break tests were carried out on four knots (the bowline, double bowline, figure-of-eight loop and perfection loop) and two splices (three-strand eye splice and braid-on-braid splice). The factors affecting their strength were investigated. A statistical approach to the analysis of the results was adopted. The type of knot was found to have a significant effect on the strength. This same effect was seen in both types of rope construction (three-strand and braid-on-braid). Conclusions were also drawn as to the effect of splice length, eye size, manufacturer and rope diameter on the breaking strength of splices. Areas of development and further investigation were identified

A platform for efficient, thiol-stable conjugation to albumin's native single accessible cysteine

Herein we report the use of bromomaleimides for the construction of stable albumin conjugates via conjugation to its native, single accessible, cysteine followed by hydrolysis. Advantages over the classical maleimide approach are highlighted in terms of quantitative hydrolysis and absence of undesirable retro-Michael deconjugation