Analysis of a homologous series of non-reducing oligosaccharides from Arnica montana L. Roots

The oligosaccharide component compositions of a series of non-reducing oligosaccharides extracted from the roots of Arnica montana L. has been determined by gel permeation chromatography (g.p.c.). The range of oligosaccharides present was found to extend beyond the octasaccharide previously reported. with 16% to 19% of the oligosaccharides having a degree of polymerisation of between 11 and 19 and almost 3% having a degree of polymerisation greater than 20. The chromatographic behaviour of this series of oligosaccharides is compared with that observed for series of D-gluco-oligosaccharides.     

STUDIES ON YEAST ESTERASE

An esterase (carboxylic acid hydrolase EC 3 1.1.1.) has been prepared from Saccharomyces cerevisiae. This esterase is active at pH 4.4 and, though it is unstable in solution, it can be maintained in an active form either by lyophilization or by coupling to an affinity gel. At pH 4.4, yeast esterase can hydrolyse between 20 and 40% of the esters commonly present in beer, and it is capable of synthesizing ethyl acetate from ethanol and acetic acid in a simple buffered solution without the provision of a co-factor. Different yeast strains yield different amounts of esterase, and there appears to be a positive correlation between the ability of the yeast to form esterase and the level of esters present in fermentations accomplished by that yeast.     

Influence new-to-old concrete interface qualities on the behaviour of support zones of composite concrete beams

The paper describes the investigations of concrete composite units consisting of two concrete parts. In each test series the interface was differently arranged and characterised by different strength parameters. They were: non-reinforced interface with existing adhesion, reinforced interface with existing adhesion and reinforced interface with broken adhesion. Simply-supported beams were subjected to four point bending. The failure of all beams was the result of exceeding the shear resistance of the support zones, but the cracks pattern in each series was different. The paper presents the results of the tests, in particular: deflection, stresses in the longitudinal and transverse reinforcement and strains of concrete. The distribution of strains along the height of the beam and the slip between the connected parts are also described.On the basis of these data a classification of failure mechanisms of concrete composite beams is proposed, as well as the analytical criteria allowing to predict failure manner of a composite beam.     

A practical procedure to assess critical defects in pressure vessels subjected to fatigue loads

PSA pressure vessels are equipments used in refining industries for cleaning the hydrogen upcoming from the reforming or hydrogen generation unities. In one regular inspection, some embedded cracks were found in the entrance nozzle-head weld. Then, instead of advance its decommissioning and waste much time until the refinery purchase a new vessel, a structural stress analysis using the finite element method was performed in order to obtain the stress field at the site of the crack, considering the real loading cycle. Despite the acting load is only the internal pressure, the nozzle-head weld is a region where a complex stress state is present (bending and axial stresses). ASME VIII Division 2, Appendix 5 addresses this issue by applying a rule for multiaxial fatigue life estimation for non-proportional loading. With ASME estimated fatigue life results, it was applied the British Standard 7910 procedure to decide if the equipment can operate safely. The calculation also assesses the crack growing by using a modified bi-linear Paris law. Finally, it was computed how long the cracks would take to get to their critical size and then retire definitively the equipment.     

Electrochemical characterization of alternate conducting carbazole-bisthiophene units

An electrochemical and theoretical character of alternate copolymer of carbazole and bithiophene units was investigated. Polymerization is processed as two steps bielectronic oxidation of molecule. With monoelectronic oxidation is connected stable radical cation with spin located mainly on carbazole. The electrochemical properties of polymer are dependent on thickness of film deposited on electrode. In case of the thin layers one it is observed characteristic redox couple of carbazole oxidation to radical cation. Analysis of polymer behavior and results of spectrochemical measurements indicate on mixed type of electroconductivity.Molecular structures, HOMO-LUMO gaps and nature of highest occupied and lowest unoccupied molecular orbitals were also studied in presented work for oligomers ranging from monomer to octamer. The studies applied density functional theory (DFT).     

When public opposition defeats alternative water projects - The case of Toowoomba Australia

Located approximately 100 km west of Brisbane, Toowoomba is home to approximately 95,000 people. Surface water from dams is the main source of water for the city. In 2006 the residents of Toowoomba were invited to vote in a referendum (plebiscite) concerning whether or not an indirect potable wastewater reuse scheme should be constructed to supply additional water to the area. At that stage dam levels in Toowoomba were at approximately twenty percent of capacity. Toowoomba residents, after intense campaigning on both sides of the referendum debate, voted against the proposal. In July 2008 dam levels dropped to eleven percent. Stage 5 water restrictions have been in place since September 2006, subsequently mains water must not be used for any outdoor uses. This paper describes in detail how public opposition in the case of Toowoomba's referendum, defeated the proposal for a water augmentation solution. Reasons for the failure are analysed. In so doing, the paper provides valuable insights with respect to public participation in indirect potable reuse proposals, and discusses factors including politics, vested interest and information manipulation. This paper is significant because of the lack of detailed information published about failed water infrastructure projects.     

New sources of resistance to Acanthoscelides obtectus (Say) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae) in mature seeds of five species of Phaseolus

The importance of carefully applied bioassay techniques is highlighted for identifying resistance of Phaseolus spp to the bruchids Acanthoscelides obtectus (Say) and Zabrotes subfasciatus Boheman. Two potential sources of resistance are identified amongst the varieties of P. vulgaris screened. In one the presence of a lectin-like protein (LLP) was identified, which has previously been associated with resistance, while in the other, resistance may be linked to the presence of a novel protein, similar to but not the same as LLP. The use of anti-LLP antibodies are suggested as a useful tool for distinguishing between resistant and susceptible varieties. Five varieties of P. lunatus and six of P. acutifolius are shown to be resistant to A. obtectus, and the potential is recognized for transferring resistant genes to P. vulgaris via interspecific crosses.     

PNET “ONDM 2019” special issue

Photonic Network Communications -