A mixed-methods study to define Textbook Outcome for the treatment of patients with uncomplicated symptomatic gallstone disease with hospital variation analyses in Dutch trial data

Background: International consensus on the ideal outcome for treatment of uncomplicated symptomatic gallstone disease is absent. This mixed-method study defined a Textbook Outcome (TO) for this large group of patients. Methods: First, expert meetings were organised with stakeholders to design the survey and identify possible outcomes. To reach consensus, results from expert meetings were converted in a survey for clinicians and for patients. During the final expert meeting, clinicians and patients discussed survey outcomes and a definitive TO was formulated. Subsequently, TO-rate and hospital variation were analysed in Dutch hospital data from patients with uncomplicated gallstone disease. Results: First expert meetings returned 32 outcomes. Outcomes were distributed in a survey among 830 clinicians from 81 countries and 645 Dutch patients. Consensus-based TO was defined as no more biliary colic, no biliary and surgical complications, and the absence or reduction of abdominal pain. Analysis of individual patient data showed that TO was achieved in 64.2% (1002/1561). Adjusted-TO rates showed modest variation between hospitals (56.6-74.9%). Conclusion: TO for treatment of uncomplicated gallstone disease was defined as no more biliary colic, no biliary and surgical complications, and absence or reduction of abdominal pain.TO may optimise consistent outcome reporting in care and guidelines for treating uncomplicated gallstone disease

A prospective cohort study to investigate cost-minimisation, of Traditional open, open fAst track recovery and laParoscopic fASt track multimodal management, for surgical patients with colon carcinomas (TAPAS study)

Contains fulltext : 87553.pdf (publisher's version ) (Open Access)BACKGROUND: The present developments in colon surgery are characterized by two innovations: the introduction of the laparoscopic operation technique and fast recovery programs such as the Enhanced Recovery After Surgery (ERAS) recovery program. The Tapas-study was conceived to determine which of the three treatment programs: open conventional surgery, open 'ERAS' surgery or laparoscopic 'ERAS' surgery for patients with colon carcinomas is most cost minimizing? METHOD/DESIGN: The Tapas-study is a three-arm multicenter prospective cohort study. All patients with colon carcinoma, eligible for surgical treatment within the study period in four general teaching hospitals and one university hospital will be included. This design produces three cohorts: Conventional open surgery is the control exposure (cohort 1). Open surgery with ERAS recovery (cohort 2) and laparoscopic surgery with ERAS recovery (cohort 3) are the alternative exposures. Three separate time periods are used in order to prevent attrition bias. Primary outcome parameters are the two main cost factors: direct medical costs (real cost price calculation) and the indirect non medical costs (friction method). Secondary outcome parameters are mortality, complications, surgical-oncological resection margins, hospital stay, readmission rates, time back to work/recovery, health status and quality of life. Based on an estimated difference in direct medical costs (highest cost factor) of 38% between open and laparoscopic surgery (alfa = 0.01, beta = 0.05), a group size of 3 x 40 = 120 patients is calculated. DISCUSSION: The Tapas-study is three-arm multicenter cohort study that will provide a cost evaluation of three treatment programs for patients with colon carcinoma, which may serve as a guideline for choice of treatment and investment strategies in hospitals. TRIAL REGISTRATION: ISRCTN44649165

The design and application of scour anticipated designs in river related and coastal structures in various countries and their effectiveness

Keynote lecture at the ICSE2006. Various types of scour can confront the engineer, who has to design and construct a hydraulic structure in a marine environment. The engineer is interested in the magnitude of the scour to be expected and its development in time. He hopes that such information, if at all available, is accurate and that he can base his design and construction method on such information without meeting any unexpected hydraulic response. In principle the engineer can react differently, according to the situation: 1 he accepts that scour will develop after completion of the structure and, given its extent and rate of development, he takes measures to prevent (or limit) damage to the structure and loss of stability; 2 he tries to prevent the scour or, in any case, takes measures to keep it away from the structure; 3 he is aware of the possibility that the works will be only exposed to scour during construction and he takes temporary measures to limit the damage; 4 he completely under-estimates or is not aware of any danger of scour and must repair the damage afterwards against high cost. In the paper is elaborated the said situations, as encountered by my colleagues and myself, by presenting five case histories. They will be presented in chronological order as one learns always from mistakes. Moreover, one starts usually by having responsibility for small projects and ends up doing large projectsHydraulic EngineeringCivil Engineering and Geoscience

Study of methods used for closure of tidal channels, first interim report

Within the context of Development Co-operation the Government of the Netherlands is providing Technical Assistance to the Government of Bangladesh for projects in the field of irrigation and flood control. One of the Projects in South West Bangladesh which was proposed by the BWDB for early implementation concerns the closure of the tidal river Madargong in order to complete Polder no. 5. Methods of closing tidal channels as at present applied in Bangladesh have been developed in an empirical manner. As in the future the size of closure gaps will increase a more systematic approach will be required to close those bigger gaps without mishaps. It was therefore agreed that a study would be made of closure methods in Bangladesh. This first Interim Report deals with the Madargong Closure. In addition it describes the closure methods applied in Bangladesh in detail and indicates similar techniques developed in the past in The Netherlands. The following conclusions were drawn after making a field visit to South-West Bangladesh in June 1976 and discussions with BWDB officers and closure contractors. The closure of Madargong River can be carried out as proposed by the BWDB by a local contractor on a Lump Sum basis provided that the principle "no cure no pay" is amended in a satisfactory way. The closure methods at present employed in South-West Bangladesh in general can be considered to be sound from a technical point of view as a remarkable result is reached in a short time practically without basic technical data and by making full use of local labour, local materials and local skill. In order to obtain more detailed information on various hydraulic and soilmechanic characteristics of Bangladesh' closure methods it is proposed to have two experts carrying out measurements and making observations during the forthcoming closure of Madargong River. Having obtained this information it will be possible to consider the introduction of elements of Dutch closure methods for the wider gaps to be closed during future polderization schemes

Fighting Against the Current: Restoring dike breaches and closing tidal channels by simple means - from past to present

The dissertation focussed on the kind of closure methods used, in the past and at present, to repair breached dikes and to close tidal channels by simple means. By simple means one must think about the application by (mainly) manual labour of local materials and small-scale tools and equipment. The closure of tidal channels is also required in reclamation schemes and to construct dams between islands or from an island to the mainland.This research was in the first place aimed at Dutch closure methods as practised in the Netherlands, Germany (Schleswig Holstein) and Ghana/Bangladesh (20th century). But it was also considered useful to check the closure methods used in other countries than the ones just mentioned. Typical topics addressed have been hydraulic features, materials and equipment applied, the importance of manual labour in these closures and their output.Related topics addressed in this dissertation are the development in time of closure methods and the reasons why sometimes closures failed. Though flood embankments and sea defences as part of reclamation works have been constructed from the 11th/12th century onward, limited technical information about their construction as well as possible subsequent repairs after breaching, could only be traced for six projects carried out during a period of more than 400 years (1263 – 1675). More information could be traced about the methods and constructions used in general but not for specific projects.The closure methods used during the period 1200 – 1700, nearly always started by dumping a horizontal sill of clay clods up to the level of Low tide. Subsequently, the gap was narrowed by dumping clay clods, and the actual closure was, finally, effected by lowering constructions made up of sink-fascines (fascines imprisoning a gravel core or clay clods) and clay clods.. Alternatively, a cofferdam could be constructed across the flow gap. In case of low tidal ranges, a row of sheet piles or piles, closely placed to each other, was driven across the gap. Sometimes, ships were ballasted and sunk on top of the sill.At the end of the 17th century floating fascine mattresses were introduced in closure works. They were ballasted and immersed in the breach or tidal channel and functioned as bed protection of the easily erodible soil. Moreover, the aforementioned sill could now be constructed by stacking fascine mattresses on top of each other, again up to the level of Low tide. Subsequently, the closure was performed gradually in a horizontal direction by constructing a bund in sections, comprising fascines, clay clods, stones and wattle work.From the end of the 19th century up to the middle of the 20th century jetties were constructed across the gap to be closed. A narrow gauge railway track on the jetty enabled the dumping of clay clods or stones in the gap from side tip wagons. Until the Second World war the side tip wagons were loaded by hand and in most cases pushed by manual labour. During past centuries in many cases simple means were not adequate to close dike breaches and, consequently, the flooded polders could not be reclaimed and had to be given back to the sea.In the period 1969 – 1985 Dutch closure techniques based on the principles described above were introduced for tidal closures in Ghana and Bangladesh. This required the adaptation of the said closure techniques to locally available construction materials, equipment and skills. Also here, a significant input of manual labour was part of the closure operation.Closure techniques applied in China, East-Pakistan (which, later became independent as Bangladesh), England and Japan were also studied. It was surprizing to learn that the sink-fascine (having in each country another name, other dimensions and composition) had a major role in closure projects in China and East-Pakistan and, to a lesser extent, in Japan. Moreover, the application of ropes and hawsers (as in the Dutch fascine constructions) turned out to be of vital importance. In China and Japan the closures were required to repair dike breaches along non-tidal rivers. In East-Pakistan and England the closures studied were in the tidal zone. Finally, a tidal closure performed in Bangladesh (at the Nalian River) by manual labour and simple means in the year 2020, has been studied. The 75 case histories presented in this dissertation reflect the art of river and tidal closures by simple means over a period of nearly 760 years (1263 – 2020) in six countries. In most cases the area of the tidal basin which could be closed by simple means was less than 2 km2 while the tidal volumes were less than 2 million m3. Production rates in tidal closures varied between 0.26 and 0.62 m3 of fill placed per manhour.But most of the simple means described can be considered as history. There are, however, countries where cheap manual labour is abundantly available and tidal closures could still be constructed by simple means. Such closures by simple means have been described for the year 1969 (Ghana) and the period 1979 – 2020 (Bangladesh). The insights from this dissertation will therefore also be useful for future closures constructed by using simple means.Hydraulic Structures and Flood Ris

Energiewaterbouwkunde

Vraag en aanbod van electriciteit, waterkracht uit rivieren, stuwmeren, reservoirs, stuwdammen, turbines, voorbeelden (Kainji, Opac, PAC), kleinschalige waterkracht, waterkracht in Nederland. Koelwatersystemen, windenergiesystemen, golfenergie, OTEC.Hydraulic EngineeringCivil Engineering and Geoscience

Feni closure dam, final design report

Overview report of the final design of the Feni closure dam in Banglades

Een Nederlands Watermerk op het culturele erfgoed van de Europese Unie

Twee artikelen ovr de geschiedenis van de Nederlandse Waterbouw als aanzet voor een project over hierover geïnitieerd door de Provincie Noord-Holland. Het eerste artikel gaat over de Nederlandse inbreng in de waterbouw in de periode tot 1800, het tweede gaat over de meer recente periode

Design and contract documents for closing of the Madargong in Polder 5 in Khulna District

The Madargong is located in Syamnagar Police Station of Satkhira Division, Khulna District. The closure of the Madargong was approved in 1975 to be executed as part of the Early Implementation Projects, under the Technical Assistance Programme of the Netherlands Government. The work was to be carried out by the Syamnagar SubDivision of the Bangladesh Water Development Board. However, the subseguent attempt to close the Madargong (1977-1978) failed, as was the case in 1970. It should be noted that these two closure attempts failed due to negligence and mismanagement of the Contractor. The 1978 attempt was done after having protected the river bed. The mattresses prevented scouring and another attempt could be made after the first failure. The introduction of bottom protection was done as a first phase of a Study regarding different closure methods suitable to be executed by manual labour. The methods are based on a combination of practices as used formerly in The Netherlands and those used locally at present. The methods should be applicable for closures of larger estuaries, The result of the study and a description of the conducted field experiments are given in three interim reports: "Study of Methods used for Closing Tidal Channels", Early Implementation Projects on Flood Control and Irrigation in Bangladesh, October 1976, August 1977 and August 1978. The report on the Chakamaya closure is still under preparation. It has been suggested to again take up the closure of the Madargong. Technical Assistance would then be provided under the Delta Development Project, while construction costs should be covered by funds originating from Early Implementation Projects. Haskoning has prepared this report, having received the assignment from the Netherlands Authorities to provide technical assistance concerning the closure component of the Delta Development Project. The closure will be designed as a vertical closure with gunny bags and mattresses, more or less similar to the Chakamaya closure, implemented in 1979

Getijcentrale in de Brouwersdam: De proefcentrale Brouwerssluis

DELTA NV heeft in december 2007 opdracht gegeven aan de TU Delft, Faculteit Civiele Techniek en Geowetenschappen, voor het verrichten van een verkennende studie naar de mogelijkheden van energiewinning bij introductie van een (gedempt) getij op het Grevelingenmeer. In het Eindrapport betreffende deze studie (dat in juni 2008 werd uitgebracht) wordt gesteld dat het mogelijk is om bij de Brouwersdam energie uit het getij te winnen met een jaarlijkse opbrengst van 143 to 392 GWh. De hoogte van de mogelijke opbrengst is direct afhankelijk van de maximaal toegestane peilvariatie op het Grevelingenmeer. Kort daarop is, vooruitlopend op een besluit t.a.v. een getijcentrale in de Brouwersdam, besloten op korte termijn stappen te ondernemen voor het plaatsen van een proefinstallatie in één van de kokers van de Brouwerssluis in de Brouwersdam. Vervolgens zijn er tijdens een bespreking in Middelburg afspraken gemaakt tussen Rijkswaterstaat, DELTA NV en de TU-Delft t.a.v een ‘Pilot getijde-energie in de Brouwerssluis’. In dit rapport presenteert de TU Delft zijn bevindingen t.a.v deze pilot. Omdat Rijkswaterstaat de Brouwerssluis zoveel tijd als mogelijk open wil laten staan heeft men de gedachte laten varen om de proefinstallatie in een bestaande koker te bouwen. Immers voor een dergelijke inbouw zou de betreffende sluiskoker zes maanden tot een jaar zijn afgesloten. Deze beperking leidt er toe om een turbinegenerator voor te stellen die kan worden ingebouwd in een caisson. De caisson wordt drijvend aangevoerd, vervolgens gepositioneerd en afgezonken tegen een kokerinlaat aan de meerzijde van de Brouwerssluis. Indien gewenst kan een dergelijke caisson na afloop van de proefperiode eventueel weer worden opgedreven en verwijderd. Een andere mogelijkheid zou zijn geweest om een z.g.n stroomturbine op te hangen in de inlaatopening van een koker aan de meerzijde. Met een dergelijke stroomturbine wordt echter niet voldaan aan de eis van DELTA NV ‘dat een dergelijk demonstratieprojekt alleen zinvol is als er ervaring mee kan worden opgedaan voor een toekomstige centrale als beschreven in het eerder genoemde rapport. Modelonderzoek heeft uitgewezen dat de netto jaarlijkse nergieopbrengst van de proefinstallatie bij een dubbelzijdig werkende bulb-turbine met een diameter van 3,5 m omstreeks 2,0 GWh kan zijn. De proefinstallatie kan hiermee de electriciteit leveren voor 550 tot 600 huishoudens. Het vermogen van de turbine zal 570 á 600 kW zijn. De kosten voor het bouwen van de caisson ( 33,6 (l) x 8,3(b) x 15 (h) m3), het vervoeren, plaatsen en afzinken, het leveren en inbouwen van de turbine-generator, enz. zal zo’n \u80 12 miljoen bedragen. Hoewel een afzonderlijke economische benadering voor een proefinstallatie hier in feite niet op zijn plaats is, zij vermeld dat men bij een bedrijfsperiode van 20 jaar uitkomt op een kWh-prijs van 52 eurocent, bij 40 jaar wordt dit 38 eurocent. Als men rekent met een voorbereidingstijd van een jaar en een bouwtijd van 1,5 jaar zou de proefinstallatie medio 2011 in bedrijf kunnen zijn.Hydraulic EngineeringCivil Engineering and Geoscience