Quasi-balanced two-wave mixing interferometer for remote ultrasound detection

We present an improved detection scheme for a two-wave mixing interferometer with a Bi₁₂SiO₂₀ crystal. The proposed detection scheme allows quasi-balanced detection of ultrasonic signals whereby electrical disturbances are suppressed. Quasi-balancing is achieved by changing the polarity of the high voltage at the photorefractive crystal, leading to an inversion of the optical interference signal, in combination with inversion of the detector signal using a signal inverter before the data acquisition device. The polarity of the high voltage is changed by utilizing an H-bridge consisting of five high-voltage relays. Microcontrollers are used to synchronize the reversion of the high voltage at the photorefractive crystal and the inversion of the measured signals. We demonstrate remote measurement of ultrasonic waves and shown that electrical disturbances are suppressed using the quasi-balanced mode.     

Synthese eines geschützten cyclischen Disulfidoktapeptides A6–13 der (Ala12)-Schafinsulin-A-Kette

Synthesis of a Protected Cyclic Disulphide Octapeptide A6-13 of the (Ala¹²)-Sheep Insulin-A-Chain The synthesis of a protected (Ala¹²)-sheep insulin-A-chain octapeptide with a 6,11-disulphide ring using the combination of A6,11-S-trityl/A 7-S-diphenylmethyl thiol protecting groups is described. For the formation of the cyclic disulphide octapeptide 2 the linear octapeptide, Boc-Cys(Trt)Cys(Dpm)AlaGlyValCys(Trt)Ala-Leu-OH ( 1 ), is prepared by a 4 + 4- as well as a 3 + 2 + 3-fragment condensation scheme followed by treatment with iodine in methanol. Most of the peptide coupling reactions were performed using the azide technique obtaining the intermediate peptide fragments in good yields. For the characterization of the cyclic disulphide peptide 2 the ¹³C-n.m.r.-spectroscopy was used in combination with other usual methods.     

Optische Diagnostik an Vakuumlichtbögen

Advanced optical diagnostics of vacuum arc plasma for switching applications Vacuum technology provides environmentally compatible and emission-free solutions for switching in power grids. A high number of operations under standard load conditions, safe and reproducible short-circuit current interruption capability, and maintenance-free operation are few examples of advantages of vacuum circuit breakers. Further development of such devices requires fundamental knowledge about the switching process and interaction of materials used with the working medium – the vacuum arc plasma. The optical diagnostics offers numerous methods for the characterization of the arc plasma and surrounding components, like e.g. electrodes and chamber walls. Studies of plasma and electrode phenomena by combination of optical and electrical diagnostics allow for material qualification, choice of design and arc extinguishing mechanisms.     

Optimising online review inspired product attribute classification using the self-learning particle swarm-based Bayesian learning approach

Bowing to the burgeoning needs of online consumers, exploitation of social media content for extrapolating buyer-centric information is gaining increasing attention of researchers and practitioners from service science, data analytics, machine learning and associated domains. The current paper aims to identify the structural relationship between product attributes and subsequently prioritise customer preferences with respect to these attributes while exploiting textual social media data derived from fashion blogs in Germany. A Bayesian Network Structure Learning model with the K2score maximisation objective is formulated and solved. A self-tailored metaheuristic approach that combines self-learning particle swarm optimisation (SLPSO) with the K2 algorithm (SLPSOK2) is employed to decipher the highest scored structures. The proposed approach is implemented on small, medium and large size instances consisting of 9 fashion attributes and 18 problem sets. The results obtained by SLPSOK2 are compared with the particle swarm optimisation/K2score, Genetic Algorithm/K2 score and ant colony optimisation/K2 score. Results verify that SLPSOK2 outperforms its hybrid counterparts for the tested cases in terms of computational time and solution quality. Furthermore, the study reveals that psychological satisfaction, historical revival, seasonal information and facts and figure-based reviews are major components of information in fashion blogs that influence the customers.     

Creep and fatigue behavior of a novel 2-component paste-like formulation of acrylic bone cements

The fatigue and creep performance of two novel acrylic bone cement formulations (one bone cement without antibiotics, one with antibiotics) was compared to the performance of clinically used bone cements (Osteopal V, Palacos R, Simplex P, SmartSet GHV, Palacos R+G and CMW1 with Gentamicin). The preparation of the novel bone cement formulations involves the mixing of two paste-like substances in a static mixer integrated into the cartridge which is used to apply the bone cement. The fatigue performance of the two novel bone cement formulations is comparable to the performance of the reference bone cements. The creep compliance of the bone cements is significantly influenced by the effects of physical ageing. The model parameters of Struik’s creep law are used to compare the creep behavior of different bone cements. The novel 2-component paste-like bone cement formulations are in the group of bone cements which exhibit a higher creep resistance.     

Functional and multivalued dependencies in nested databases generated by record and list constructor

The impact of the list constructor on two important classes of relational dependencies is investigated. Lists represent an inevitable data structure whenever order matters and data is allowed to occur repeatedly. The list constructor is therefore supported by many advanced data models such as genomic sequence, deductive and object-oriented data models including XML. The article proposes finite axiomatisations of functional, multivalued and both functional and multivalued dependencies in nested databases supporting record and list constructor. In order to capture different data models at a time, an abstract algebraic approach based on nested attributes is taken. The presence of the list constructor calls for a new inference rule which allows to infer non-trivial functional dependencies from multivalued dependencies. Further differences to the relational theory become apparent when the independence of the inference rules is investigated. The extension of the relational theory to nested databases allows to specify more real-world constraints and increases therefore the number of application domains. * Results of this article were partly presented at the 3rd International Symposium on Foundations of Information and Knowledge Systems (FoIKS), Vienna, Austria, 2004 [58], and the 23rd International Symposium on Principles of Database Systems (PODS), Paris, France, 2004 [54]. ** Sebastian Link was supported by Marsden Funding, Royal Society of New Zealand.