Fortnightly modulation of the estuarine circulation in Juan de Fuca Strait

Riverine discharge into the Strait of Georgia sets up a well-defined estuarine circulation within Juan de Fuca Strait, the main path for the freshwater outflow to the continental shelf. At the landward end of Juan de Fuca Strait, the water flows through narrow channels in which strong tidal currents are known to induce significant mixing of the water column, and a spring-neap modulation of the estuarine exchange. A three-dimensional prognostic numerical model has been developed to study the circulation around Vancouver Island, British Columbia. In a series of simulations, the estuarine circulation within Juan de Fuca Strait is established by the Fraser River freshwater discharge. A fortnightly modulation is imposed on the mixing over the various sills to simulate the spring-neap tidal mixing regime. The resulting variation in the estuarine circulation is found to be largely limited to the eastern section of Juan de Fuca Strait, in the vicinity of the sills. Data from current meter moorings and surface salinity data from lighthouse stations compare favorably with the model results. The effect of local wind forcing on the estuarine exchange is also examined. The model is capable of simulating those rare events during which a concurrence of river freshet, neap tide and northwest wind allows a stronger pulse of fresh surface water to escape relatively unmixed into the eastern end of Juan de Fuca Strait. The disturbance then propagates along the northern shore of the strait as a first mode internal Kelvin wave. Finally, the effect of the fortnightly modulation on the export of freshwater onto the continental shelf is examined. It is found that small amplitude coastal trapped waves are generated near the mouth of Juan de Fuca. However, this fortnightly signal is weak in comparison to the energetic wind-induced variations typically found over the shelf

Observations and modeling of seasonal variability in the Straits of Georgia and Juan de Fuca

The Strait of Georgia is a large semi-enclosed basin on the southern coast of British Columbia. Its main connection to the Pacific is to the south, through Juan de Fuca Strait. Abundant freshwater discharge, mainly from the Fraser River, forces an estuarine exchange with oceanic shelf water. The resulting circulation is modulated by tides and winds. Both the coastal wind stress and the flux of freshwater are subject to strong seasonal modulations, producing a marked seasonal cycle in the water properties and circulation of the region. The seasonal variability of the Strait of Georgia and Juan de Fuca Strait is described using data from a series of recent cruises conducted over a five-year period, in addition to longer term historical data sets. To complement the observations, the data are compared with numerical simulations based on the Princeton Ocean Model (POM). Forced with tides, freshwater discharge and seasonal wind stress, the model is integrated over a few years until the system approaches statistical equilibrium. Results show good agreement with observations from Juan de Fuca Strait, as well as over the upper part of the water column within the Strait of Georgia. However, simulation of the seasonal cycle of the deeper waters of the Strait of Georgia is more problematic. The deep water properties apparently are determined by a delicate balance between dense intrusions from the sill area and local vertical mixing

Glamočak (Marina), La transition guerrière yougoslave

« L’ouvrage de Marina Glamočak, tiré de sa thèse, richement documenté, va faire date parce qu’il remonte aux causes de la décomposition sanglante de l’ex-Yougoslavie » (p. 7). Cette première phrase de la préface d’Alain Joxe résume parfaitement la démarche intellectuelle de M. Glamočak. Sociologue, l’auteur a voulu sortir des cadres “étriqués” des théories existantes sur la « transition à la démocratie » et proposer une grille de lecture différente de l’éclatement de la Fédération yougoslave...

NMR study of structure and mechanisms of superabsorbent polymers

Commercially important superabsorbent polymers are crosslinked polymers of partially neutralised acrylic acid which can typically absorb and retain up to a hundred times their own weight in water. Superabsorbent polymers are most widely used in the personal hygiene industry where they are found in the core of disposable nappies, external feminine sanitary products and adult incontinence pads as absorbents for bodily fluids. Many other applications have been found through their amazing absorptive properties including artificial snow, artificial muscles and the prevention of water leakage into underground transmission cables. Superabsorbent polymers have many important industrial uses although little investigation into their structure and mechanisms has been done to date. As a result of superabsorbent polymers being totally insoluble in all NMR solvents solid state ¹³C CP/MAS NMR was used to investigate various structural aspects of the polymer in both dry and hydrated states. The NMR work carried out on the structure of the superabsorbent polymers suggests differences in structure between polymers neutralised before and after polymerisation takes place. It also suggests different tacticity within the polymer, seen as the polymer becomes more hydrated. ²³Na relaxational studies have given an insight into the change in the sodium ion environment as the polymer becomes more hydrated. The effect of increasing neutralisation of the polymer was also investigated. Nuclear Magnetic resonance imaging was also used to try and investigate the mechanism of absorption of liquid by the polymer. From the images produced it was seen that the liquid is not absorbed homogeneously throughout the polymer sample and a more intense region is seen at the front of the image suggesting a solvent front. Commercial superabsorbent polymers are usually coated to enhance their absorptive properties. Experiments were carried out using a sodium ion-selective electrode to try and determine whether or not this coating provided the polymer with an osmotic ion-exclusion membrane. The sodium ion-selective electrode allowed differences in [Na⁺] before and after the addition of polymer to a solution of NaCl to be detected, and consequently allowed the presence of an osmotic ion-exclusion membrane to be determined

Bernard (Antonia), éd., La Slovénie et l'Europe. Contributions à la connaissance de la Slovénie actuelle

Les ouvrages en français consacrés à la Slovénie sont trop rares et chaque nouvelle parution sur cette petite république ex-yougoslave apparaîtrait presque comme un événement bibliographique. Spécialiste de la Slovénie et maître de conférences à l'INALCO, Antonia Bernard s'entoure ici de onze contributeurs de choix pour dresser un portait de ce pays aujourd'hui. Membre de l'UE et de l'OTAN, la Slovénie entend occuper une véritable place sur la scène internationale, et joue notamment un rôle m..

La péninsule de Prevlaka

Au printemps 2002, à la suite de la visite du ministre croate des Affaires étrangères Tonino Picula à Belgrade, la question de Prevlaka semblait être en voie de règlement, dix ans environ après le début de ce contentieux micro-territorial entre la Croatie et la Yougoslavie. Bien que petite par sa taille, deux kilomètres de long et 500 mètres de large, la péninsule de Prevlaka occupe une place stratégique. Située à l’extrémité méridionale du littoral croate et à deux kilomètres seulement de la..

Yves TOMIĆ, La Serbie du prince Miloš à Milošević

L'ouvrage d'Yves Tomic comble un vide bibliographique important en France, puisqu'il retrace l'histoire de la Serbie (et non des Serbes, ce qui constitue une différence majeure) depuis le début du XIXe siècle jusqu'à nos jours. La démarche de l'auteur, historien de formation, est de resituer les événements des deux dernières décennies du XXe siècle en Serbie (et dans les Balkans) dans la longue durée de la « construction nationale serbe », afin d'en permettre une meilleure compréhension. Cinq..

Anthropometric study to understand body size and shape for plus size people at work

Over 60% of the adult population in the United Kingdom is now overweight/obese or classed as ‘plus size’ and as the incidence of being plus size rises the demographics of the working population have also changed. A first stage scoping study [1] found that fit (equipment, tools, furniture, uniforms and personal protective equipment) and space (circulation and shared spaces within the working environment) were issues of concern to plus size people. This suggests that aspects of the current design of the workplace are not suitable and may exclude plus size people and a better understanding of the anthropometric requirements of plus size workers is needed. This paper will present the findings of an Anthropometric Measurement Validation Study to establish if self-measured anthropometric data (including novel measures such as knee splay) in a plus size working age population is feasible as the data collection method for a larger scale survey. A sample of 20 plus size working participants (10 male and 10 female) aged 18 years and over were recruited. Data were collected for weight and stature, and 12 anthropometric measurements recorded via self-measurement and researcher measurement for comparison. Self-measurement was completed by participants following instructions in a self-measurement guide. Data analysis using t-tests found that the two methods of measurement (self and researcher) agreed sufficiently closely for 11 of the 14 measurements. This resulted in the self-measurement method being utilised for data collection in an ongoing larger scale anthropometric study to understand the body size and shape for plus size people at work

Plus size anthropometry: Is designing for the 95th percentile enough?

Over 60% of the adult population in the United Kingdom is now overweight/obese or classed as ‘plus size’. As the incidence of being plus size rises the demographics of the working population have also changed. This paper will present, the results of a plus size anthropometry study, using self-reported anthropometric data taken for 14 key anthropometric measurements. 101 participants, recruited via a non-probability sampling strategy completed the study which aims to identify the body size and shapes of plus size working age people

Plus size and inclusivity in design

The number of people classed as ‘plus size’, meaning overweight or obese is increasing and many feel excluded from every day activities and environments. Whilst the need to cater for a diverse population in terms of anthropometry is recognized, rarely are the emotional and social aspects of interactions with design/environments taken into account. This paper presents the findings of an interview study to explore barriers affecting plus size people with regard to inclusivity in their lives. The findings suggest that emotional responses to physical issues are important to consider and will contribute to recommendations to raise awareness and facilitate empathy