Feasibility of monitoring large wind turbines using photogrammetry

Photogrammetry, which is a proven measurement technique based on determination of the 3D coordinates of the points on an object by using two or more images taken from different positions, is proposed to be a promising and cost efficient alternative for monitoring the dynamic behavior of wind turbines. The pros and cons of utilizing this measurement technique for several applications such as dynamic testing or health monitoring of large wind turbines are discussed by presenting the results of the infield tests performed on a 2.5 MW - 80 m diameter - wind turbine.     

Child maltreatment moderates the association of MAOA with symptoms of depression and antisocial personality disorder.

There is a growing body of data indicating that Gene × Child Maltreatment interactions at monoamine oxidase A (MAOA) play a role in vulnerability to symptoms of antisocial personality disorder (ASPD) but not major depression (MD). Using a sample of 538 participants from the Iowa Adoption Studies, we introduce a conceptual model that highlights two distinct pathways from child maltreatment to symptoms of MD, suggesting that maltreatment has different effects depending on genotype and highlighting the importance of including the indirect pathway through ASPD. As predicted by the model, high activity alleles predispose to symptoms of MD in the context of child maltreatment whereas low activity alleles predispose to symptoms of ASPD. We conclude that the Gene × Environment interplay at this locus (MAOA) contributes to both symptoms of ASPD and MD and that careful specification of child maltreatment may be essential if genetic association research is to produce replicable results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerical Modeling of Turbulent Melt Flow in a Continuous Casting Mold Affected by an Electromagnetic Brake

The current work combines numerical and experimental investigations based on a small-scale mockup using the eutectic alloy GaInSn.The jet flow discharging from the submerged entry nozzle was exposed perpendicularly to a DC magnetic field across the entire wide face of the mold.Numerical calculations were performed by using the commercial package CFX with an implemented RANS-SST turbulence model.The anisotropic properties of the MHD turbulence were taken into account by specific modifications of the turbulence model.The comparison between our numerical calculations and the experimental results shows a very well agreement.In particular,the modified RANS-SST turbulence model is capable to reconstruct the peculiar phenomenon of the excitation of non-steady,non-isotropic large-scale flow perturbations caused by the application of the DC magnetic field.Another important finding of our study is the feature that the electrical boundary conditions,namely the wall conductivity ratio,have a great impact on the mold flow subjected to an external magnetic field.     

Japanese Manufacturing Techniques: Nine Hidden Lessons in Simplicity

Compound orthogonal arrays (COAs) and single arrays are alternatives to the inner–outer arrays advocated by Taguchi for robust parameter design experiments. A criterion based on the word type pattern and strength of COAs is proposed to select optimal COAs. Single arrays are classified into prodigal single arrays (PSAs) and economical single arrays (ESAs) according to their relative estimation capacities, and various optimality criteria, again based on the word type pattern, are proposed for selecting optimal single arrays. Useful optimal COAs, PSAs, and ESAs are constructed and tabulated as convenient references for experimenters in practice.     

Rational protein design of ThDP-dependent enzymes-engineering stereoselectivity

Benzoylformate decarboxylase (BFD) from Pseudomonas putida is an exceptional thiamin diphosphate-dependent enzyme, as it catalyzes the formation of (S)-2-hydroxy-1-phenylpropan-1-one from benzaldehyde and acetaldehyde. This is the only currently known S-selective reaction (92 % ee) catalyzed by this otherwise R-selective class of enzymes. Here we describe the molecular basis of the introduction of S selectivity into ThDP-dependent decarboxylases. By shaping the active site of BFD through the use of rational protein design, structural analysis, and molecular modeling, optimal steric stabilization of the acceptor aldehyde in a structural element called the S pocket was identified as the predominant interaction for adjusting stereoselectivity. Our studies revealed Leu461 as a hot spot for stereoselectivity in BFD. Exchange to alanine and glycine resulted in variants that catalyze the S-stereoselective addition of larger acceptor aldehydes, such as propanal with benzaldehyde and its derivatives-a reaction not catalyzed by the wild-type enzyme. Crystal structure analysis of the variant BFDL461A supports the modeling studies.     

Identification of late-stage glycosylation steps in the biosynthetic pathway of the anthracycline nogalamycin

Nogalamycin is an anthracycline antibiotic that has been shown to exhibit significant cytotoxicity. Its biological activity requires two deoxysugar moieties: nogalose and nogalamine, which are attached at C7 and C1, respectively, of the aromatic polyketide aglycone. Curiously, the aminosugar nogalamine is also connected through a C-C bond between C2 and C5'. Despite extensive molecular genetic characterization of early biosynthetic steps, nogalamycin glycosylation has not been investigated in detail. Here we show that expression of the majority of the gene cluster in Streptomyces albus led to accumulation of three new anthracyclines, which unexpectedly included nogalamycin derivatives in which nogalamine was replaced either by rhodosamine with the C-C bond intact (nogalamycin R) or by 2-deoxyfucose without the C-C bond (nogalamycin F). In addition, a monoglycosylated intermediate-3',4'-demethoxynogalose-1-hydroxynogalamycinone-was isolated. Importantly, when the remaining biosynthetic genes were introduced into the heterologous host by using a two-plasmid system, nogalamycin could be isolated from the cultures, thus indicating that the whole gene cluster had been identified. We further show that one of the three glycosyltransferases (GTs) residing in the cluster-snogZ-appears to be redundant, whereas gene inactivation experiments revealed that snogE and snogD act as nogalose and nogalamine transferases, respectively. The substrate specificity of the nogalamine transferase SnogD was demonstrated in vitro: the enzyme was able to remove 2deoxyfucose from nogalamycin F. All of the new compounds were found to inhibit human topoisomerase I in activity measurements, whereas only nogalamycin R showed minor activity against topoisomerase II.     

Design of Cyclic Peptides Featuring Proline Predominantly in the cis Conformation under Physiological Conditions

Turns are secondary‐structure elements that are omnipresent in natively folded polypeptide chains. A large variety of four‐residue β‐turns exist, which differ mainly in the backbone dihedral angle values of the two central residues i+1 and i+2. The βVI‐type turns are of particular biological interest because the i+2 residue is always a proline in the cis conformation and might thus serve as target of peptidyl prolyl cis/trans isomerases (PPIases). We have designed cyclic hexapeptides containing two proline residues that predominantly adopt the cis conformation in aqueous solution. NMR data and MD calculations indicated that the cyclic peptide sequences c‐(‐D Xaa‐Ser‐Pro‐D Xaa‐Lys‐Pro‐) result in highly symmetric backbone structures when both prolines are in the cis conformation and the D ‐amino acids are either alanine or phenylalanine residues. Replacement of the serine residue either by phosphoserine or by tyrosine compromises this symmetry, but further increases the cis conformation content of both prolines. As a result, we obtained a cyclic hexapeptide that exists almost exclusively as the cis‐Pro/cis‐Pro conformer but shows no cis/trans interconversion even in the presence of the PPIase Pin1, apparently due to an energetically quite favorable but highly restricted conformational space.     

Strong Reactivity Enhancement through Molecular Traffic Control in Zeolites

In the past, the investigation of catalytic reactivity enhancement through molecular traffic control (MTC) by means of dynamical Monte Carlo simulations of catalysis was initiated in simple, idealized zeolite channel networks. These results are reviewed here and, emphasizing more recent work, the conditions of reactivity enhancement through MTC are examined for a realistic channel topology based on the pore structure of the zeolite TNU‐9. For a wide range of reaction rates a very strong MTC effect can be found that increases with grain size. This effect is argued to be a generic feature of a certain class of zeolite pore topologies.     

In-Operation Monitoring of the Soot Load of Diesel Particulate Filters: Initial Tests

Diesel particulate filters (DPF) are indispensable parts of modern automotive exhaust gas aftertreatment systems due to the stringent emissions legislation. For a fuel-efficient control strategy, it would be beneficial to determine directly and in-operation their actual trapped soot mass. Two novel approaches—based on the electrical conductivity of trapped soot particles—emerged recently. By measuring the electrical resistance between different single walls inside the filter, the soot load is determined with local resolution. The microwave-based technique is a contactless approach that gives an integral value depending on the soot mass in the DPF. We present investigations on loading and regeneration of DPFs in a dynamometer test bench applying both methods. The results are compared with each other and correlated with the differential pressure and the soot mass. Especially the microwave-based technique has a potential for serial application.