The Evolution of Cost Control Systems: a Cultural Phenomenon

This paper only aims at stimulating research and debate, starting from two ideas:• historically, cost control systems have undergone major changes by integrating an increasing level of instability;• the same pattern of evolution can be found in other areas.Evolutions seem to have gone through four stages:1. A static period. Individuals think in terms of a stable environment in which there is only one truth. Problems are solved through an analytical approach.2. A period of static balance. Although there is some movement, unchanging laws prevail. The environment is a deterministic one in which the future is modelled on the past. The only systems that can be conceived are closed , dependent ones.3. A period of dynamic balance. Some change is introduced in the laws regulating trends. The environment may thus be transformed and tentatively brought under control. Systems tend to become open ended and adaptable.4. A period when the probabilistic order of confusion prevails. Although the movement has become widespread, it cannot be foreseen in detail. However, major events are somehow predictable according to statistical laws. Overall transformations remain undetermined. Systems improve and become more effective by constant updating and upgrading.Those four stages have been observed in five different fields:• cost control systems in organisations• the history of economic theory• natural sciences• information technology• philosophy.This evolution of course did not affect the five fields in the same manner or at the same pace. It is however important to note that the stages are identical whatever the field i.e. that changes in thinking patterns shifted from one stage to another.management control

Magnetic induction and diffusion mechanisms in a liquid sodium spherical Couette experiment

We present a reconstruction of the mean axisymmetric azimuthal and meridional flows in the DTS liquid sodium experiment. The experimental device sets a spherical Couette flow enclosed between two concentric spherical shells where the inner sphere holds a strong dipolar magnet, which acts as a magnetic propeller when rotated. Measurements of the mean velocity, mean induced magnetic field and mean electric potentials have been acquired inside and outside the fluid for an inner sphere rotation rate of 9 Hz (Rm 28). Using the induction equation to relate all measured quantities to the mean flow, we develop a nonlinear least square inversion procedure to reconstruct a fully coherent solution of the mean velocity field. We also include in our inversion the response of the fluid layer to the non-axisymmetric time-dependent magnetic field that results from deviations of the imposed magnetic field from an axial dipole. The mean azimuthal velocity field we obtain shows super-rotation in an inner region close to the inner sphere where the Lorentz force dominates, which contrasts with an outer geostrophic region governed by the Coriolis force, but where the magnetic torque remains the driver. The meridional circulation is strongly hindered by the presence of both the Lorentz and the Coriolis forces. Nevertheless, it contributes to a significant part of the induced magnetic energy. Our approach sets the scene for evaluating the contribution of velocity and magnetic fluctuations to the mean magnetic field, a key question for dynamo mechanisms

Spark plasma sintered carbon electrodes for electrical double layer capacitor applications

The spark plasma sintering (SPS) is an emerging process for shaping any type of materials (metals, ceramic, polymers and their composites). The advantage of such a process is to prepare densified ceramic materials in a very short time, while keeping the materials internal porosity. In the present work, we have used the SPS technique to prepare activated carbon-based electrodes for Electrochemical Double Layer Capacitor applications (EDLC). Self-supported 600 and 300µm-thick electrodes were prepared and characterized using of Electrochemical Impedance Spectroscopy and galvanostatic cycling in a non-aqueous 1.5MNEt4BF4 in acetonitrile electrolyte. Electrochemical performance of these sintered electrodes were found to be in the same range – or even slightly better – than the conventional tape-casted activated carbon electrodes. Although organic liquid electrolyte was used to characterize the electrochemical performance of the sintered electrodes, these results demonstrate that the SPS technique could be worth of interest in the ultimate goal of designing solid-state supercapacitors

Original Conductive Nano-Co3O4 Investigated as Electrode Material for Hybrid Supercapacitors

Cobalt oxides have been extensively used as conductive additives for Ni-MH batteries. We report in this paper the performances of an original nanometric cobalt oxide, close to Co3O4, as electrode material for hybrid supercapacitors. This spinel type phase contains hydrogen, lithium, cobalt vacancies, and especially Co4þ ions within the structure, leading to a high electronic conductivity. Cyclic voltammetry and impedance spectroscopy measurements show interesting capacitance (320 F/g in 8M-KOH), as well as good electrochemical cycling with a small amount of carbon black (5%)

Horizontal Cylindrical Structures in an Unconsolidated Quaternary Deposit at Saint-Joachim, Near Québec City (Canada)

Two series of six horizontal cylindrical structures (pipes) were discovered recently in a Late Pleistocene (11‑10 ka BP) emerged delta deposit about 40 km NE of Québec City, Canada. The pipes occur at a depth of 19 m in a slightly oxydized layer of fine sand which is interlayered with two strata of compact blue silty clay, respectively 35 and 45 cm in thickness. The maximum length of the pipes is not known, but the remaining exhumed pipes measure 34 to 59 cm. Their diameter ranges from 6.5 to 14.5 cm. The pipe core generally consists of clean and loose medium to coarse sand whereas the outer ring, made of oxydized fine sand, is semi-consolidated. Pipes are the result of water flow in a permeable sand layer enclosed between two non-permeable layers; water enclosed in a shallow basin created by local collapsing was under hydraulic pressure and forced to drain out on the delta front. These water escape features are possibly the first known site of horizontal cylindrical structures observed in unconsolidated Quaternary sediments.Deux séries de structures cylindriques horizontales ont été observées récemment dans un dépôt deltaïque émergé mis en place à la fin du Pléistocène (11‑10 ka BP), à une quarantaine de kilomètres au nord-est de la municipalité de Québec. Sises à 19 m de profondeur, les structures cylindriques occupent un lit de sable fin, légèrement oxydé, inséré entre deux couches d’argile silteuse, bleue, compacte, respectivement de 35 et 45 cm d’épaisseur. La longueur maximale atteinte par les structures est inconnue en raison de l’exploitation avancée de la gravière. Toutefois, dans la partie restante, dégagée manuellement, elles ont une longueur minimale comprise entre 34 et 59 cm. Le centre des cylindres est composé de sable, moyen à grossier, non stratifié alors que l’enveloppe extérieure de quelques centimètres d’épaisseur est constituée de sable fin, oxydé et semi-induré. Les structures horizontales ont été formées après la mise en place du dépôt par un écoulement souterrain d’eau sous pression hydraulique provenant d’une cuvette peu profonde produite par un affaissement local. La pression a été suffisamment forte pour créer des cavités de type suffosion. Lors de la baisse de pression, elles ont été comblées par des sédiments plus grossiers que la couche encaissante. L’eau, qui a migré parallèlement aux couches, devait s’écouler sur le front du delta. Ces structures cylindriques horizontales semblent les premières du genre à avoir été observées dans un dépôt meuble quaternaire