The generation of bending sequences in a CAPP system for sheet-metal components

An important process-planning task in sheet-metal manufacturing is the determination of bending sequences for individual components. Computer-aided generation of these sequences, as part of a computer-aided process-planning (CAPP) system, can relieve the workload of process-planning departments, this being especially important in small batch manufacturing environments. This paper discusses the functions that have to be performed during the determination of bending sequences, focusing on accuracy aspects. The generation of bending sequences is also put into the broader perspective of an integrated CAPP system such as PART-S, which is under development presently in the author's laboratory

Structured education can improve primary-care management of headache: the first empirical evidence, from a controlled interventional study

Headache disorders are under-recognized and under-diagnosed. A principal factor in their suboptimal management is lack of headache-related training among health-care providers, especially in primary care. In Estonia, general practitioners (GPs) refer many headache patients to neurological specialist services, mostly unnecessarily. GPs request diagnostic investigations, which are usually unhelpful and therefore wasteful. GP-made headache diagnoses are often arcane and non-specific, and treatments based on these are inappropriate. The aim of this study was to develop, implement and test an educational model intended to improve headache-related primary health care in Estonia.This was a controlled study consisting of baseline observation, intervention and follow-up observation using the same measures of effect. It involved six GPs in Põlva and the surrounding region in Southern Estonia, together with their future patients presenting consecutively with headache as their main complaint, all with their consent. The primary outcome measure was referral rate (RR) to neurological specialist services. Secondary measures included number of GP-requested investigations, GP-made headache diagnoses and how these conformed to standard terminology (ICD-10), and GP-recommended or initiated treatments.RR at baseline (n = 490) was 39.5 %, falling to 34.7 % in the post-intervention group (n = 295) (overall reduction 4.8 %; p = 0.21). In the large subgroup of patients (88 %) for whom GPs made clearly headache-related ICD-10 diagnoses, RR fell by one fifth (from 40 to 32 %; p = 0.08), but the only diagnosis-related RR that showed a statistically significant reduction was (pericranial) myalgia (19 to 3 %; p = 0.03). There was a significant increase towards use of more specific diagnoses. Use of investigations in diagnosing headache reduced from 26 to 4 % (p < 0.0001). Initiation of treatment by GPs increased from 58 to 81 % (p < 0.0001).These were modest changes in GPs entrenched behaviour. Nevertheless they were empirical evidence that GPs practice in the field of headache could be improved by structured education. Furthermore, the changes were likely to be cost-saving. To our knowledge this study is the first to produce such evidence

Improving the utilization of silver carp (Hypopthalmichthys molitrix) and other under-utilized fish species : fact finding and goal establishing mission to the Islamic Republic of Iran (31 january - 5 february 2004)

In recent years a scientific cooperation between Wageningen-UR and the Iranian Fisheries Research Organisation (IFRO), related to the Iran Fishery Organisation Shilat about processing has been started. In February 1999 a draft memorandum of understanding on fisheries co-operation has been signed. Identified fields of co-operation were for instance Research and Development, especially of value added products, e.g. kilka, promotion of trade of fish and fisheries products between the two countries and also training. Referring to the memorandum the scientific program for collaboration on processing of fish has started on 25 February 2002 (paragraph 3. Production, processing and trade of aquatics/ research). In the Netherlands this cooperation has been made concrete by the project approval of ¿Improving the utilization of Silver Carp and other under-utilized fish species; phase 1: fact finding and goal establishing mission to Iran¿ as part of the DWK 404 project. In this project are involved: ¿Netherlands: Animal Science Group Fishery Research, (Frans Veenstra and Jeroen Kals), Agrotechnology &Food Innovations (Paul Bartels en René Koster), Dir. Visserijen (Pieter de Rijk) and the Dutch embassy in Tehran (Cees Gravendaal). ¿Iran: Iranian Fisheries Research organisation (IFRO) Hamid R. Alizadeh, Ali Farzanfar, Mansour Sadrian and Mr. Arshad from the Iranian national aquatic processing centre. The mission to Iran was made at 31 January ¿ 5 February. Three institutes has been visited for discussion of a bilateral research proposal in the north of Iran: - The National Aquatic Processing Center at Anzali Port - International Sturgeon Research Institute affiliated to IFRO at Rasht City ¿ Sanga - Iranian Fisheries Research Organization (IFRO) at Tehran Also the Iranian Fisheries Organization (Shilat) at Tehran has been visited for this purpose. Goal of the mission has been the definition of the objectives for the bilateral research that gives the highest added value to the economy of Iran and the Netherlands, in such a form that the research creates scientific collaboration on processing of fish. As a result of the discussions a proposal has been written for further research based on the processing of the fresh water Silver Carp (Hypopthalmichthys Molitrix). Important items are: -Production of a proper fillet without the unpleasant fatty tissue bones and skin and fresh preservation of this fillet for distribution -Processing of mince and the development of new products for better distribution and utilization of the fish meat. In the Netherlands small scale research will be carried out and contacts with industry will be made for further development. Pilot experiments for implementation of the new processes and products will be made at the IFRO. IFRO will put the same amount of effort to the project as in the Netherlands will be budgete

Fractal nature in fat crystal networks

The determination of the mechanical and rheological characteristics of several plastic fats requires a detailed understanding of the microstructure of the fat crystal network aggregates. The fractal approach is useful for the characterization of this microstructure. This review begins with information on fractality and statistical self-similar structure. Estimations for fractal dimension by means of equations relating the volume fraction of solid fat to shear elastic modulus G’ in linear region are described. The influence of interesterification on fractal dimension decrease (from 2,46 to 2,15) for butterfat-canola oil blends is notable. This influence is not significant for fat blends without butterfat. The need for an increase in research concerning the relationship between fractality and rheology in plastic fats is emphasized.La determinación de las características mecánicas y reológicas de ciertas grasas plásticas requiere conocimientos detallados sobre las microestructuras de los agregados que forman la red de cristales grasos. El estudio de la naturaleza fractal de estas microestructuras resulta útil para su carac­terización. Este artículo de información se inicia con descripciones de la dimensión fractal y de la "autosimilitud estadística". A continuación se describe el cálculo de la dimensión fractal mediante ecuaciones que relacionan la fracción en volumen de grasa sólida con el módulo de recuperación (G') dentro de un comportamiento viscoelástico lineal. Se destaca la influencia que la interesterificación ejerce sobre la dimensión fractal de una mezcla de grasa láctea y aceite de canola (que pasa de 2,64 a 2,15). Esta influencia no se presenta en mezclas sin grasa láctea. Se insiste sobre la necesidad de incrementar las investi­gaciones sobre la relación entre reología y estructura fractal en grasas plásticas.Peer reviewe

Report Task 2.3: Particulate waste and turbidity in (marine) RAS

Particulate waste management and removal is one of the most problematic parts of recirculation aquaculture systems (RAS). Particulate waste and thereby turbidity originates from three major sources: fish (faeces), feed and biofilm (heterotrophic bacteria and fungi). Based on size and density there are roughly four categories of particulate waste: settable, suspended, floatable and fine or dissolved solids. Specific problems related to high turbidity are a decreasing feed intake by fish, causing lower growth and increasing feed loss; an increasing risk regarding pathogens increasing disease problems and gill irritation; a higher oxygen consumption of the system and more complicate visual observation of fish, which is a necessity for good farm management. Good particulate matter and turbidity control is one of the key factors determining the success of RAS. The goal of this task is to get a better understanding of the nature of turbidity and the role of the different water treatment units within RAS and finally find ways to achieve a better control of turbidity

De samenstelling van discards in de pelagische visserij voor valorisatie doeleinden

Vanaf januari 2015 wordt de discard regelgeving vanuit de EU aangepast, dit betekent dat de sector zich moet committeren aan deze regelgeving. Hierdoor zullen de bijvangsten die op dit moment nog overboord gaan, aangeland moeten worden. Er is een traject ingezet om de kansen tot valorisatie van de bijvangsten te ontwikkelen

Potentiele soorten voor de Nederlandse Aquacultuur: rapportage deelproject 2

In deze studie naar potentiële nieuwe vis, schaal- en schelpdiersoorten voor de aquacultuur in Nederland is een selectiemethode ontwikkeld aan de hand van de methode zoals beschreven door Le Francois. De selectieprocedure bestaat uit 4 rondes die gebaseerd zijn op basis van criteria van zowel technische als economische aard. Daarnaast is meegewogen of een soort op verantwoorde wijze te kweken is. De ontwikkelde selectieprocedure resulteert in een top 93 van de meest potentiële vis en schaaldiersoorten en een top 43 van de meest potentiële schelpdiersoorten voor de aquacultuur in Nederland. Van de top 10 van beide lijsten, zoals weergegeven in onderstaande tabel, is per soort een fact sheet gemaakt met daarin een introductie, informatie rondom de teelt, de markt en kort wat opmerkingen met betrekking tot de tekortkomingen, kansen en of bedreigingen. Onder een potentiële soort wordt verstaan een soort waarvan de kans groot geacht wordt dat commerciële productie in Nederland binnen enkele jaren succesvol ontwikkeld kan worden. Ten behoeve van de daadwerkelijke realisatie van de teelt van een potentiële soort zal in veel gevallen verregaand technisch, biologisch, markt dan wel economisch onderzoek noodzakelijk zijn. Belangrijk te vermelden is dat binnen het kader van deze studie geen berekeningen zijn gemaakt met betrekking tot de verwachte productiekosten voor de potentiële soorten onder Nederlandse omstandigheden. Het is daarom mogelijk dat uit vervolgonderzoek alsnog blijkt dat commerciële productie van een soort in Nederland niet mogelijk is