The relation between preset distinguishing sequences and synchronizing sequences

We study the relation between synchronizing sequences and preset distinguishing sequences which are some special sequences used in finite state machine based testing. We show that the problems related to preset distinguishing sequences can be converted into related problems of synchronizing sequences. Using the results existing in the literature for synchronizing sequences, we offer several reflections of these results for preset distinguishing sequences. Although computing a preset distinguishing sequence is PSPACE-hard , we do identify a class of machines for which computing a preset distinguishing sequence can be performed in polynomial time and argue that this class is practically relevant. We also present an experimental study to compare the performance of exponential brute-force and polynomial heuristic algorithms to compute a preset distinguishing sequence.     

Metal-Containing Polymers Synthesized via Acyclic Diene Metathesis (ADMET) Polymerization Using Electrochemically Reduced Tungsten-Based Catalyst: Polycarbogermanes

Various germanium-containing dienes, bis(4-pentenyl)diethylgermanium (1), bis(4-pentenyl)dimethylgermanium (2) and bis(3-butenyl)diethylgermanium (3), were synthesized and polymerized using an electrochemically reduced tungsten-based catalyst system via acyclic diene metathesis (ADMET) polymerization. All polymer structures were characterized by ¹H- and ¹³C-NMR spectroscopy. These results indicate the retention of the double bonds in the polymer structure with high trans content (57–70%) as expected from a step condensation reaction. These polymers have low molecular weight (M _W) that range from 7400 to 19,100. The thermal stability of polymers was evaluated by thermogravimetric analysis. The glass transition temperatures of the polymer of monomer 1, 2 and 3 were −24, −9 and −47°C, respectively. Synthesis, characterization and the general limitations of ADMET polymers obtained by this catalyst are discussed. An erratum to this article can be found at     

Preparation of single-site tin(IV) compounds and their use in the polymerization of ε-caprolactone

Butyltin(IV) carboxylate compounds were obtained by reactions of butyltrichlorotin(IV) with potassium pivalate, perfluoroheptanoate, methacrylate, 2,6-pyridinedicarboxylate, and phthalate. The synthesized complexes were fully characterized by nuclear magnetic resonance (¹H-, ¹³C-NMR), Fourier transform infrared (FTIR), mass spectroscopies (MS) and elemental analysis. These tin complexes were used as catalysts for the ring opening polymerization of ε-caplolactone and the conversion of monomers to polymers was completed in just 1 h. The structures of polymers were characterized by a combination of spectroscopic techniques (NMR, FTIR, MS), differential scanning calorimeter (DSC) and gel permeation chromatography. In this study, the ε-caplolactone polymers with different average molecular weights between 5000 and 40,000 Da having a regular structure were obtained.     

Potential application of microalga Spirulina platensis as a protein source

The high protein level of various microalgal species is one of the main reasons to consider them an unconventional source of this compound. Spirulina platensis stands out for being one of the richest protein sources of microbial origin (460–630 g kg^?1, dry matter basis), having similar protein levels when compared to meat and soybeans. The use of S. platensis in food can bring benefits to human health owing to its chemical composition, since it has high levels of vitamins, minerals, phenolics, essential fatty acids, amino acids and pigments. Furthermore, the development of new protein sources to supply the shortage of this nutrient is an urgent need, and protein from S. platensis plays an important role in this scenario. In this sense, extraction processes that allow maximum protein yield and total utilization of biomass is an urgent need, and ultrasonic waves have proven to be an effective extraction technique. The number of scientific papers related to protein fraction from S. platensis is still limited; thus further studies on its functional and technological properties are needed. © 2016 Society of Chemical Industry     

Processing Conditions and Aging Effect on the Morphology of PZT Electrospun Nanofibers, and Dielectric Properties of the Resulting 3–3 PZT/Polymer Composite

Lead zirconate titanate (PZT) nanofibers are obtained by electrospinning a sol–gel based solution and polyvinyl pyrrolidone (PVP) polymer, and by subsequent sintering of the electrospun precursor fibers. The average diameter of the precursor PZT/PVP green fibers has increased with the aging of the precursor solution along with an increase in the viscosity. Bead-free uniform green PZT/PVP fibers were collected at about an ∼230 nm average fiber diameter using a 28 wt% PVP ratio solution with a viscosity of 290 mPa. Shrinkage of 40% was recorded on the fiber diameter after sintering. The X-ray diffraction pattern of the annealed PZT fibers exhibits no preferred orientation and a perovskite phase. Preparation of 3–3 nanocomposites by the infusion of polyvinylester into the nanofiber mat facilitates successful handling of the fragile mats and enables measurements of the dielectric properties. The dielectric constant of the PZT/polyvinylester nanocomposite of about 10% fiber volume fraction was found to be fairly stable and vary from 72 to 62 within the measurement range. The dielectric loss of the composite is below 0.08 at low frequencies and reaches a stable value of 0.04 for most of the measured frequencies.     

Determination of metals in fish and mussel species by inductively coupled plasma-atomic emission spectrometry

The concentrations of cadmium, iron, lead, zinc, copper, manganese, nickel, chromium and cobalt were determined by ICP-AES in muscles, livers, gills and skins of two fish (Clarias gariepinus and Carasobarbus luteus), and in muscles and gills of two mussel species (Unio terminalis and Potamida littoralis) sampled from the Lake Gölba??. Iron showed the highest levels in all examined tissues of both fish species. Following Fe; Zn showed the second highest levels in all examined tissues of both fish species except Mn levels in muscle and gill of C. luteus. In both mussel species, to the contrary fish, manganese showed the highest levels in examined tissues, and followed by Fe. In both fish species, the all metal concentrations in livers were higher than those in muscles. Concentrations in tissues of the analyzed metals were significantly affected by species. There were differences between the metal levels in the similar tissues of the different species (p < 0.05). At the same time, there was also the differences between the metal concentrations in different tissues of the same species (p < 0.05). Metal levels in tissues were compared with national and international permissible limits. Metal concentrations in both edible and other tissues of the sampled species were within the permissible safety levels for human uses.     

Torsional dynamics of coaxial nanotubes with different lengths in viscoelastic medium

Microsystem Technologies - Torsional vibration analysis of double-walled carbon nanotube system embedded in viscoelastic medium is carried out in the present work. Hamilton’s Principle is...