Experimental study on a breaking-enforcing floating breakwater

Floating breakwaters are moored structures that attenuate wave energy through a combination of reflection and dissipation. Studies into floating breakwaters have been generally restricted to optimising the attenuation performance. This study presents a novel floating breakwater type that was developed to have good attenuation performance while keeping wave drift loads as small as possible. The floating breakwater was designed as a submerged parabolic beach that enforces wave energy dissipation through breaking. The design was tested in a 3D shallow-water wave basin in captive and moored setups for regular and irregular wave conditions. Results are presented in terms of attenuation performance, motions, and (mooring) loads. The results show that the breaking of waves improves the attenuation performance of the floater in captive setup. However, in moored setup, the attenuation performance was dominated by diffraction and radiation of the wave field, with breaking being of secondary importance. This shows that breaking-enforcing floating breakwaters have potential, but require a high vertical hydrostatic and/or mooring stiffness in order to enforce intense breaking. Mean wave drift loads on the object showed significant difference between breaking and non-breaking waves in both setups, with breaking waves leading to lower normalized loads. This is attributed to breaking-induced set-up and set-down of the water level. As a result, the new breakwater design has a more favourable balance between wave attenuation and drift loads than common (i.e., box-, pontoon-, or mat-type) floating breakwater designs. Tests with varying surface roughness showed that floating breakwaters may benefit from dual-use functions that naturally increase the roughness (e.g., shellfish, vegetation), which have a marginal effect on the attenuation performance, but increase the added mass and hydrodynamic damping and as such, reduce mooring line loads

Colorectal liver metastases: Surgery versus thermal ablation (COLLISION) - a phase III single-blind prospective randomized controlled trial

Background: Radiofrequency ablation (RFA) and microwave ablation (MWA) are widely accepted techniques to eliminate small unresectable colorectal liver metastases (CRLM). Although previous studies labelled thermal ablation inferior to surgical resection, the apparent selection bias when comparing patients with unresectable disease to surgical candidates, the superior safety profile, and the competitive overall survival results for the more recent reports mandate the setup of a randomized controlled trial. The objective of the COLLISION trial is to prove non-inferiority of thermal ablation compared to hepatic resection in patients with at least one resectable and ablatable CRLM and no extrahepatic disease. Methods: In this two-arm, single-blind multi-center phase-III clinical trial, six hundred and eighteen patients with at least one CRLM (≤3cm) will be included to undergo either surgical resection or thermal ablation of appointed target lesion(s) (≤3cm). Primary endpoint is OS (overall survival, intention-to-treat analysis). Main secondary endpoints are overall disease-free survival (DFS), time to progression (TTP), time to local progression (TTLP), primary and assisted technique efficacy (PTE, ATE), procedural morbidity and mortality, length of hospital stay, assessment of pain and quality of life (QoL), cost-effectiveness ratio (ICER) and quality-adjusted life years (QALY). Discussion: If thermal ablation proves to be non-inferior in treating lesions ≤3cm, a switch in treatment-method may lead to a reduction of the post-procedural morbidity and mortality, length of hospital stay and incremental costs without compromising oncological outcome for patients with CRLM. Trial registration:NCT03088150 , January 11th 2017

Soil survey as a basis for land evaluation

status: publishe

Soil maps of Africa - European digital archive on the soil maps of the world (Series I)

An initiative for building up an European Archive on the soil maps of the world was adopted by transforming the existing soil map in ISRIC into digital form. In the first phase of this archive establishment, the soil maps pertaining to African continent (approximately 2034 maps) were scanned and converted into high resolution digital maps. These information rich maps need to be put in format suitable for divulgation to the wider public. Wherein, the importance of the preparation of a DVD-ROM enriched with the complete set of soil maps of the African continent ina well organised form is foreseen, The DVD-ROM will consist of digital form from the soil maps assisted with appropriate navigation tools. A print of 500 copies of the DVD-ROM is includes ad final deliverable.JRC.H.6-Spatial data infrastructure

EUROPEAN SOIL BUREAU ⎯ RESEARCH REPORT NO. 7 World Reference Base for Soil Resources – in a nutshell

Since its endorsement by the IUSS in 1998, the World Reference Base for Soil Resources has established itself as a comprehensive soil correlation system. The system has so far been translated into 9 languages and is used and tested all over the world. This paper describes the WRB in a nutshell. Although originally designed for general-purpose soil correlation at world scale, WRB is increasingly used as a classification system. The issue of strict ranking of taxa and the rationale behind ranking have been major points of debate; a ranking scenario is presented here, mainly to stimulate the discussion