A study on posidonia residue in seawater intakes

The reliability of a sea-water desalination plant relies largely on an efficient intake system. This is not easily ensured in large areas of the Mediterranean, where the residue of a particular seagrass, Posidonia 0ceanica, is often found in large quantities. To separate or avoid this residue, which can cause operational problems, considerable technical and economical efforts are required.

This paper presents the results of a design and operation-oriented experimental study on Posidonia. This study deals with aspects such as concentration in sea-water, distribution of sizes in residue samples, sedimentation properties, bulk densities and resistance of sea-grass cakes to sea-water flow, and is supported by direct practice in desalination in Libya. Experience confirms that the analysis of the behaviour and physical properties of Posidonia residue, together with accurate site survey, enable one to design a tailored solution, thus avoiding an unreliable standardized system or an uneconomical sophisticated or over-dimensioned solution, not necessarily reliable when unassisted by field data.     

Impact of new materials and construction systems on fire test technology

New construction techniques and the growing number of building materials have resulted in the modification of old fire test methods and the development of new ones. Many otherwise useful materials have failed the highly restrictive noncombustibility test that is in use today. The author suggests that tests more basis than the full scale fire endurance tests must be devised to more accurately evaluate the effects of combustible materials under fire conditions. Note: This paper was presented at the annual meeting of the Society fo Fire protection Enginneers at Washington, D. C., May 19, 1965, as part of a program arranged by the Chesapeake Chapter of SFPE.     

An Approach for Enhancement of Saturation Magnetization in Cobalt Ferrite Nanoparticles by Incorporation of Terbium Cation

Cobalt ferrite nanoparticles were synthesized by a reverse micelle process. The optimum processing conditions required to fabricate nanocrystalline cobalt ferrite using a reverse micelle technique, especially the effect of water-to-surfactant molar ratios including w = 8, 10, 12, and 14, pH values in the range of 8 to 11, and annealing temperatures in the range of 400°C to 800°C, were evaluated. x-Ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), vibrating-sample magnetometry, and superconducting quantum interference device analysis were employed to evaluate the structural and magnetic properties of synthesized nanoparticles. XRD analysis confirms that the nanoparticles have a single-phase cubic spinel structure. The average particle size increases with increasing pH value and annealing temperature. Magnetization study reveals that the cobalt ferrite nanoparticles exhibit a superparamagnetic trend. The zero-field-cooled magnetization curves of cobalt ferrite nanoparticles indicated that, with an increase in pH value, the blocking temperature increases. Based on the obtained optimum parameters, terbium-substituted cobalt ferrite nanoparticles with composition CoFe_2?x Tb _x O₄ (x = 0.1 to 0.5) were prepared by a reverse micelle process. XRD and field-emission scanning electron microscopy evaluation demonstrated that single-phase spinel ferrites with narrow size distribution were obtained. Mössbauer spectroscopy was used to determine the site preference of terbium cation. The results confirm that terbium cations were distributed at tetrahedral and octahedral sites, but with a preference for the former. It was observed that, with an increase in terbium content, the saturation magnetization increases.     

Herausforderungen im modernen Tagebaubetrieb

The article gives ideas for the further development of planning and operation in surface mining. The key role play integrated approaches, like integrated mine planning considering the cutting resistances, integrated planning and operation, integration of exploration, extraction and processing, and integrated consideration of environmental impacts, e.g. geohydrochemical aspects in dumping. The integration approach to consolidate separate processes can contribute to discover new potentials to guarantee safety, environmental acceptability, public acceptance and economy of the system as a whole. Important bricks in these developments are efficient navigation systems, which are today widely accessible, like GPS, sensors to identify process controlling parameters, e.g. rock characteristics for selective mining and dumping, and powerful information technologies for data storage and processing. Additional topics are new developments in mining machines, mining technologies and automation, which are mentioned only in general, on the example of new cutting tool design.     

Generic Management – Agile Unternehmensführung in einem dynamischen UmfeldHubert Biedermann1 und Thomas Schneeberger2

For 50 years teaching and research at the Department of Economic and Management Sciences has been dealing with the management of companies and their units based on the economic principle. Since the early 1990s, the aspects of quality and of environment as well as of risk and security have played an increasing role in the orientation of the companies. The focus on production factors has therefore been expanded, and a general model of leadership has been developed, which includes economic, environmental, and social objectives and is able to structure the management with regard to the dynamics and complexity of the business environment. In addition to resource efficiency, competitive aspects are addressed that contribute to long-term growth and meet the expectations of stakeholders. Complemented by a transformation model, the Generic Management Model provides a framework of models, methods, and tools for agile corporate governance mastering complexity.     

Optimal trajectory planning with application to industrial robots

A procedure is presented for planning optimal trajectories for application to industrial robots. First, trajectories are optimised by considering the nominal dynamics of a robot with rigid links and joints and with constraints on joint torque and speed. The minimum-time optimisation criterion is complemented by a miminal dynamic energy criterion that leads to smoother actuator inputs that do not excite joint vibrations. Weighting factors for these cost functions are then determined by trial simulations. By these means the effect of controller characteristics and elasticity, friction and backlash in the joints may be taken into account. A minimum-time movement for the real-world robot is obtained which displays the dynamical behaviour predicted in the planning procedure. Results from measurements and simulations for a PUMA 562 robot illustrate the approach. Further improvements may be achieved by a custom controller with the feedforward torques as shown in a comparison of trajectories executed with a VAL2 controller and a custom controller.     

Intelligent measurement in clinical medicine — Analysis and examples

The paper analyses the concepts of intelligent measurement and instrumentation in relation to artificial intelligence. It describes examples of the application of intelligent measurement in clinical medicine: in particular, inferential measurement, the learning of patterns and measurement interpretation and its use in decision support in the total medical information system.