Integration of prebend optimization in a holistic wind turbine design tool

This paper considers the problem of identifying the optimal combination of blade prebend, rotor cone angle and nacelle uptilt, within an integrated aero-structural design environment. Prebend is designed to reach maximum rotor area at rated conditions, while cone and uptilt are computed together with all other design variables to minimize the cost of energy. Constraints are added to the problem formulation in order to translate various design requirements. The proposed optimization approach is applied to a conceptual 10 MW offshore wind turbine, highlighting the benefits of an optimal combination of blade curvature, cone and uptilt angles

Free-Form Design of Rotor Blades

This work investigates an integrated free-form approach for the design of rotor blades, where airfoil shapes are treated as unknowns. This leads to the simultaneous optimization of the chord, twist and structural design variables, together with the airfoil shapes along the blade. As airfoils are automatically tailored to the evolution of the blade, this process results in a better exploration of the solution space and relieves the user from the burden of up-front choices, leading to better final designs. The proposed approach is demonstrated by sizing a 2 MW wind turbine blade

A Research Framework for the Multidisciplinary Design and Optimization of Wind Turbines

The design of very large wind turbines is a complex task which requires the development of dedicated tools and techniques. In this chapter, we present a system-level design procedure based on the combination of multi-body numerical models of the turbine and a multilevel optimization scheme. The overall design aims at the minimization of the cost of energy (COE) through the optimization of all the characteristics of the turbine, and the procedure automatically manages all the simulations required to compute relevant loads and displacements. This unique setup allows the designer to conduct trade-off studies in a highly realistic virtual environment and is an ideal test bench for advanced research studies in which it is important to assess the economic impact of specific design choices. Examples of such studies include the impact of stall-induced vibrations on fatigue, the development of active/passive control laws for large rotors, and the complete definition of 10–20 MW reference turbines

Traffic effects on soil compaction and sugar beet (Beta vulgaris L.) taproot quality parameters

Soil compaction is a critical issue in agriculture having a significant influence on crop growth. Sugar beet (Beta vulgaris L.) is accounted as a crop susceptible to compaction. Reduction of leaf area, final yield, and root quality parameters are reported in compacted soils. The most obvious visual indicator of topsoil compaction is root depth affected by agricultural tractor and machinery traffic up on the soil. Such indicators are mainly correlated to initial soil condition, tyre features, and number of passages. Monitoring and controlling frequency and position of machine traffic across the field, in such a way that passages are completed on specific, well-defined tracks, can assist with minimization of compaction effects on soil. The objective of the present work was to analyze the subsoil compaction during the growing period of sugar beet with different farming approaches including controlled traffic passages and random traffic. To this end, tests were carried out following each agro technical operation using penetrometer readings in order to monitor the state of cone-index after each step. In addition, at the harvesting time, root quality parameters were analyzed with particular attention to length and regularity of the taproot, total length, circumference, mass, and above-ground biomass. Such parameters were usefully implemented in order to evaluate the effects of controlled traffic passages compared to the random traffic in a cultivation of sugar beet. Results highlight how an increase in crop yield, derived from samples monitored, higher than 10% can be expected with implementation of a careful traffic management

Tragovi metala u tkivima Galeus melastomus (Rafinesque, 1810) iz sjevernog dijela Tirenskog mora (SZ Mediteran)

In the last decades, the decline of coastal waters resources has forced fisheries to expand into deeper waters. However, while the increase of industrial activities make it essential to find biological models that can explain pollutants dynamics, little is still known about pollutants distribution, dynamics, and their possible effects on deep-water organisms. In this context, new information on the concentrations of trace metals (Arsenic, As; Cadmium, Cd; Copper, Cu; Mercury, Hg; Lead, Pb) in muscle, liver and gonads of blackmouth catshark, Galeus melastomus, from north-western Mediterranean (northern Tyrrhenian Sea) are presented. Significant differences between males and females were found in the concentrations of three of the five trace elements in gonads. Lower concentrations of trace metals were found in the ovaries, and this could be due to the almost continuous vitellogenic activity which could transfer contaminants to developing oocytes.Pad resursa u obalnim vodama u posljednjih nekoliko desetljeća prisilio je ribarstvo da se proširi i na dublje vode. Međutim, dok je zbog porasta industrijskih aktivnosti bitno pronaći biološke modele koji mogu objasniti dinamiku zagađivala, malo se zna o njihovoj distribuciji i dinamici te o njihovim mogućim učincima na dubokomorske organizme. U tom kontekstu, prikazane su nove informacije o koncentraciji tragova metala (arsen, As; kadmij, Cd; bakar, Cu; živa, Hg; olovo, Pb) u mišićima, jetrima i gonadama mačke crnouste, Galeus melastomus, iz sjeverozapadnog Mediterana (sjever Tirenskog mora). Značajne razlike između mužjaka i ženki uočene su u koncentracijama od tri do pet elemenata u tragovima u gonadama. Niže koncentracije tragova metala pronađene su u jajnicima, što bi mogao biti rezultat gotovo neprekidne vitelogene aktivnosti koja može dovesti do prenošenja zagađivala do oocita u razvoju

Preoperative staging of colorectal cancer using virtual colonoscopy: correlation with surgical results

The aim of this study was to evaluate the clinical usefulness of computed tomography colonography (CTC) in the preoperative staging in patients with abdominal pain for occlusive colorectal cancer (CRC) and to compare the results of CTC with the surgical ones

MRE11 complex links RECQ5 helicase to sites of DNA damage

RECQ5 DNA helicase suppresses homologous recombination (HR) possibly through disruption of RAD51 filaments. Here, we show that RECQ5 is constitutively associated with the MRE11-RAD50-NBS1 (MRN) complex, a primary sensor of DNA double-strand breaks (DSBs) that promotes DSB repair and regulates DNA damage signaling via activation of the ATM kinase. Experiments with purified proteins indicated that RECQ5 interacts with the MRN complex through both MRE11 and NBS1. Functional assays revealed that RECQ5 specifically inhibited the 3′→5′ exonuclease activity of MRE11, while MRN had no effect on the helicase activity of RECQ5. At the cellular level, we observed that the MRN complex was required for the recruitment of RECQ5 to sites of DNA damage. Accumulation of RECQ5 at DSBs was neither dependent on MDC1 that mediates binding of MRN to DSB-flanking chromatin nor on CtIP that acts in conjunction with MRN to promote resection of DSBs for repair by HR. Collectively, these data suggest that the MRN complex recruits RECQ5 to sites of DNA damage to regulate DNA repai

An iron-sulfur cluster in the family 4 uracil-DNA glycosylases

The 25-kDa Family 4 uracil-DNA glycosylase (UDG) from Pyrobaculum aerophilum has been expressed and purified in large quantities for structural analysis. In the process we observed it to be colored and subsequently found that it contained iron. Here we demonstrate that P. aerophilum UDG has an iron-sulfur center with the EPR characteristics typical of a 4Fe4S high potential iron protein. Interestingly, it does not share any sequence similarity with the classic iron-sulfur proteins, although four cysteines (which are strongly conserved in the thermophilic members of Family 4 UDGs) may represent the metal coordinating residues. The conservation of these residues in other members of the family suggest that 4Fe4S clusters are a common feature. Although 4Fe4S clusters have been observed previously in Nth/MutY DNA repair enzymes, this is the first observation of such a feature in the UDG structural superfamily. Similar to the Nth/MutY enzymes, the Family 4 UDG centers probably play a structural rather than a catalytic role

Early putamen hypertrophy and ongoing hippocampus atrophy predict cognitive performance in the first ten years of relapsing-remitting multiple sclerosis

Background The first years of relapsing-remitting multiple sclerosis (RRMS) constitute the most vulnerable phase for the progression of cognitive impairment (CImp), due to a gradual decrease of compensatory mechanisms. In the first 10 years of RRMS, the temporal volumetric changes of deep gray matter structures must be clarified, since they could constitute reliable cognitive biomarkers for diagnostic, prognostic, and therapeutic purposes. Methods Forty-five cognitively asymptomatic patients with RRMS lasting 64\u200910 years, and with a brain MRI performed in a year from the neuropsychological evaluation (Te-MRI), were included. They performed the Brief International Cognitive Assessment battery for MS. Thirty-one brain MRIs performed in the year of diagnosis (Td-MRI) and 13 brain MRIs of age- and sex-matched healthy controls (HCs) were also included in the study. The relationships between clinical features, cognitive performances, and Te- and Td-MRI volumes were statistically analyzed. Results Cognitively preserved (CP) patients had significantly increased Td-L-putamen (P\u2009=\u20090.035) and Td-R-putamen volume (P\u2009=\u20090.027) with respect to cognitively impaired (CI) ones. CI patients had significantly reduced Te-L-hippocampus (P\u2009=\u20090.019) and Te-R-hippocampus volume (P\u2009=\u20090.042) compared, respectively, with Td-L-hippocampus and Td-R-hippocampus volume. Td-L-putamen volume (P\u2009=\u20090.011) and Te-L-hippocampus volume (P\u2009=\u20090.023) were independent predictors of the Symbol Digit Modalities Test score in all patients (r2\u2009=\u20090.31, F\u2009=\u20096.175, P\u2009=\u20090.001). Conclusion In the first years of RRMS, putamen hypertrophy and hippocampus atrophy could represent promising indices of cognitive performance and reserve, and become potentially useful tools for diagnostic, prognostic, and therapeutic purposes