A comparison between South African agricultural exports to the European union and those of other selected southern hemisphere countries

Primary Eurostat data of EU imports of agricultural products from selected southern hemisphere countries - namely, South Africa, Argentina, Chile, Australia and New Zealand - was used to compare the exports from those countries to the EU for the period 1988 to 2000. The study starts with a general overview of the total and agricultural export performance of these selected countries in a global context and their specialization indexes for food. This is followed by a comparison of the total value, total mass and value per tonne of agricultural exports to the EU and of their exploitation of seasonal differences with the northern hemisphere in terms of relative emphasis on particular product groups and value/mass ratios of their major products. Comparison is made of the impact of their location relative to EU ports in terms of transport cost and duration of trips and the efficiency of their own ports. The conclusions reached is that in order to remain competitive, South Africa will have to add value to carefully selected non-seasonal products. Seasonal production will have to expand with a sharper focus on market windows becoming narrower due to research and development conducted by both northern and southern hemisphere competitors. The overview motivates an even more aggressive research and development (R&D) programme by South African agriculture and food industries in order to remain competitive on export markets, especially given the rapidly changing environment. For example, the introduction of much faster ships which will decrease South AfricaÂ’s present advantage of having the shortest distance to the EU among the other southern hemisphere competitors.International Relations/Trade,

Fault: A Viable Means of Re-Injuecting Responsibility in Marital Relations

The era of marital fault being the only grounds for divorce in the United States has passed, and its passing brings few tears to the eyes of most. As evidenced by the passage above, the airing of marital fault in open court, even in the days when such practices were the norm, at times shocked the sensibilities and conscience of those who had to listen to the evidence and then issue decisions based upon it

Can We Estimate Air Density of the Thermosphere with CubeSats?

The measurement of air density in the Earth’s thermosphere has a wide range of scientific applications from space weather to upper atmosphere dynamics, but also technical applications from satellite control to predictions of atmospheric reentry of space debris. This study models the torques applying on a three-unit CubeSat in low Earth orbit to infer the capability of such platforms to measure the air density along their orbit. Realistic noise levels of available CubeSat components are used, and sensitivity to the various noise sources is presented. The precise knowledge of the spacecraft attitude, angular acceleration, residual magnetic dipole, and center of gravity is critical to allow proper air density retrieval. Winds in the thermosphere also have a significant impact on the thermosphere density retrieval, suggesting that this parameter can also be constrained. Attitude control is not necessary if the attitude itself is properly known. The application to the EntrySat CubeSat predicts that such retrieval is possible at altitudes lower than 200 km with errors lower than 30%. The air density retrieval from CubeSat platforms will open new capabilities to infer upper atmosphere dynamics

Model predictive control of compact combined cycles in offshore power plants integrating a wind farm

Model predictive control of compact combined cycles in offshore power plants integrating a wind farmCombined cycle gas turbine plants (CCGTs) fulfill an important role in emission reduction of offshore power systems as the bottoming cycle (BC) produces additional power from exhaust heat of the gas turbines (GTs). With increasing integration of wind turbines, CCGTs offshore must be flexible and provide variation management to the offshore energy system across multiple time scales. This work proposes a model predictive controller (MPC) sending setpoints to the CCGT to satisfy demand in the offshore power system under fluctuating wind power. A high-speed surrogate model suitable for optimizing in an MPC is identified. A linear MPC using a quadratic cost function with process constraints is formulated. The model-based control structure is then validated in simulation for satisfying a constant power demand under disturbances introduced by fluctuating wind power.acceptedVersio

Patient socioeconomic determinants for the choice of the cheapest molecule within a cluster: evidence from Belgian prescription data

Reference pricing is a common cost-sharing mechanism, with the financial penalty for the use of costly drugs shifted from the third-party payer to the patient. Unintended distributional consequences might arise, if the weakest socioeconomic groups face a relatively higher financial burden. This study analyzed for a sample of Belgian individual prescription data for 4 clusters of commonly used drugs (proton pump inhibitors, statins and two groups of antihypertensives [drugs acting on renin-angiotensin system and dihydropyridine derivatives]) whether the probability to receive the least expensive molecule within a cluster was linked to the socioeconomic status of the patient. Logistic regression models included individual demographic, working, chronic illness and financial status and small area education data for 906,543 prescriptions from 1,280 prescribing general practitioners and specialists. For the 4 clusters, results show that patients with lower socioeconomic status consistently use slightly more the least expensive drugs than other patients. Larger effects are observed for patients residing in a nursing home for the elderly, patients entitled to increased reimbursement of co-payments, unemployed, patients treated in a primary care center financed per capita (and not fee-for-service) and patients having a chronic illness. Also, patients residing in neighborhoods with low education status use more less expensive drugs. The findings of the study suggest that although equity considerations were not explicitly taken into account in the design of the reference price system, there is no real equity problem, as the costly drugs with supplement are not prescribed more often in patients from lower socioeconomic classes

Os mártires e a cristianização do território na América portuguesa, séculos XVI e XVII

O artigo investiga um grupo de atores sociais bastante relevante para viabilizar a cristianização na América portuguesa: os mártires cristãos, indivíduos muito especiais, dispostos a regar a terra com seu próprio sangue, de forma a tornar definitiva e irreversível a ocupação cristã do território. Os mártires - e principalmente a narrativa em torno deles - parecem ter sido bastante acionados para integrar a América portuguesa e seus habitantes nativos à temporalidade e territorialidade cristã. Os mártires dos séculos XVI e XVII, principalmente missionários, reeditavam os martírios do início da cristandade, que espalharam o cristianismo rumo a diversas partes do mundo na antiguidade. Dessa forma, viabilizaram a cristianização das novas fronteiras, consagrando o solo com seu sangue divino e viabilizando posteriores processos de urbanização. Além da função estratégica dos mártires para os cristãos, o texto mostra que eles também tiveram significado peculiar na interlocução com as culturas ameríndias, que tinha como um de seus principais personagens o grande guerreiro, disposto a perder seu sangue em prol de seu grupo.This paper looks into a group of social agents who played a significant role in the Christianization of Portuguese America, namely, the Christian martyrs - very special individuals who were ready to wet the land with their own blood in order to make possible a definitive and irreversible occupation of the territory by Christian settlers. The martyrs, and above all the stories told about them, seem to have been called upon to integrate Portuguese America and its native inhabitants into the temporalities and territory of Christendom. Mostly made up of missionaries, this group of 16th and 17th-century martyrs reedited the martyrdom of early Christians, who spread their creed across numerous parts of the Ancient World. They enabled the Christianization of new frontiers by consecrating the soil with their divine blood and paving the way for subsequent processes of urban development. In addition to their strategic significance for Christianity, the text also shows that their martyrdom played a specific role in the Christian settlers' interaction with Amerindian culture, whose main cults included the figure of the great warrior, ever ready to shed his own blood for his group

LotaBEL:De zoetwaterkabeljauw als kweekvis in België

status: publishe

Voortplanting bij de zoetwaterkabeljauw

status: Published onlin

Control Degrees of Freedom for Optimal Operation and Extending Remaining Useful Life

While the transition to renewable energy sources is happening faster than ever, traditional energy sources such as oil and gas still make up a large part of the energy portfolio, and will continue to do so for many years to come. Subsea technology is becoming increasingly important, as it enables production from fields which were previously deemed infeasible. However, placing production and processing equipment on the seabed comes with challenges tied to reliability and automation. Maintenance costs can be very high, since maintenance intervention of a subsea installation usually involves the retrieval and replacement of entire modules with specialized lifting ships, as well as lost production. For this reasons, unplanned maintenance interventions must be avoided. Another issue is that of uncertainty. Measurements are inaccurate and scarce. Equipment degradation models are often poor or non-existing, due to the stochastic nature of degradation processes. If not dealt with properly, this uncertainty renders useless any attempt at planning production and maintenance of the plant. In this thesis, I have addressed some of the issues of subsea operation by developing strategies for integrating equipment health and reliability information into the control and production planning, to obtain a so-called health-aware control structure. To ensure that the solution is optimal despite model uncertainty, we apply robust problem formulations. I also developed a new approach to combined optimization of maintenance scheduling and production planning. I show that for certain processes, the combined problem can be formulated as a non-linear program (NLP) instead of a mixed-integer program (MIP), and be solved using standard, off-the-shelf solvers. The solution obtained this way is near globally optimal, and performs much better than a clock- or age-based maintenance schedule, which is common in industry today