KMS states on Nica-Toeplitz algebras of product systems

We investigate KMS states of Fowler's Nica-Toeplitz algebra $\mathcal{NT}(X)$ associated to a compactly aligned product system $X$ over a semigroup $P$ of Hilbert bimodules. This analysis relies on restrictions of these states to the core algebra which satisfy appropriate scaling conditions. The concept of product system of finite type is introduced. If $(G, P)$ is a lattice ordered group and $X$ is a product system of finite type over $P$ satisfying certain coherence properties, we construct KMS$_\beta$ states of \NT(X) associated to a scalar dynamics from traces on the coefficient algebra of the product system. Our results were motivated by, and generalize some of the results of Laca and Raeburn obtained for the Toeplitz algebra of the affine semigroup over the natural numbers.Comment: Changes to Proposition 3.1 and Theorem 4.10. Major changes to section 5 starting from (and including) new Lemma 5.4 to new Example 5.1

Flow analysis of the turbine rotor tip seal on a highly rotary test rig

Workshop byl částečně podpořen projektem CZ.1.07/2.3.00/20.0139. Tento projekt je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky

Investigation of the tip-leakage losses in turbine axial stages

In turbomachinery, an influence of a tip-leakage flow on overall blade loss is crucial and its reduction is still worth striving for. In this paper a numerical analysis of the flow in tip seal of high-rotating gas turbine engine has been made. This analysis is a part of experimental research for testing the commercially used different tip seals solutions. Described test rig is predicted to be an universal tool for developing and examining different configurations of turbine blade tips. Presented numerical analysis is used to predict physical phenomena that may affect the rotor blade performance. In the numerical investigation the commercial Ansys CFX software was employed. The most important parameters were: mass flow rate at the inlet and outlet of the test bench, pressure and velocity distribution and the air temperature growth above the rotor. Also, an influence of test rig inlet and outlet geometry on flow uniformity was investigated. During the analysis the attention was focused also on minimizing the turbulence intensity in outlet area, that could cause significant difficulties in flow and stable work of the machine – generated eddies contributes to lower the mass flow rate

Partial pancreatic resection along the embryological fusion plane — no longer a fantasy

Background: The embryological connection between the dorsal and ventral pancreatic regions divides the pancreas into two segments. This anatomical dependence allows segmental pancreatic resection through the embryological fusion plane (EFP). The advantages of limited pancreatic resection are the preservation of the natural continuity and function of the gastrointestinal tract and the avoidance of the metabolic and endocrine consequences of total resectionof the pancreas and the duodenum. Materials and methods: Two patients are described who underwent anatomical segmentectomy of the pancreatic head along the EFP for the treatment of pancreatic cystic tumour and main duct intraductal papillary-mucinous neoplasm. The authors suggested diagnostic and intraoperative management leading to qualification for pancreatic resection along the EFP. Results: Pancreas and duodenum sparing surgery is an opportunity for patients in terms of the post-operative quality of life. Indications for this kind of surgery are limited and case selection is very difficult. The procedure for embryological bud resection is highly complicated includes a high rate of possible complications. On the other hand high volume centres may offer this procedure at an acceptable rate of complications in selected cases. Conclusions: Accurate diagnosis with a vascular anatomy and biliary and pancreatic duct configuration give grounds to analyse pancreas-sparing surgery. The operation plan requires careful three-dimensional planning and an experienced team. Bipolar electrocautery, micro-surgical tools and intraoperative cholangiography and pancreatography are helpful

One pot ‘click’ reactions: tandem enantioselective biocatalytic epoxide ring opening and [3+2] azide alkyne cycloaddition

Halohydrin dehalogenase (HheC) can perform enantioselective azidolysis of aromatic epoxides to 1,2-azido alcohols which are subsequently ligated to alkynes producing chiral hydroxy triazoles in a one-pot procedure with excellent enantiomeric excess.

Systematic Analysis of 22 Microlensing Parallax Candidates

We attempt to identify all microlensing parallax events for which the parallax fit improves \Delta\chi^2 > 100 relative to a standard microlensing model. We outline a procedure to identify three types of discrete degeneracies (including a new one that we dub the ``ecliptic degeneracy'') and find many new degenerate solutions in 16 previously published and 6 unpublished events. Only four events have one unique solution and the other 18 events have a total of 44 solutions. Our sample includes three previously identified black-hole (BH) candidates. We consider the newly discovered degenerate solutions and determine the relative likelihood that each of these is a BH. We find the lens of event MACHO-99-BLG-22 is a strong BH candidate (78%), event MACHO-96-BLG-5 is a marginal BH candidate (37%), and MACHO-98-BLG-6 is a weak BH candidate (2.2%). The lens of event OGLE-2003-BLG-84 may be a Jupiter-mass free-floating planet candidate based on a weak 3 sigma detection of finite-source effects. We find that event MACHO-179-A is a brown dwarf candidate within ~100 pc of the Sun, mostly due to its very small projected Einstein radius, \tilde r_E = 0.23+-0.05 AU. As expected, these microlensing parallax events are biased toward lenses that are heavier and closer than average. These events were examined for xallarap (or binary-source motion), which can mimic parallax. We find that 23% of these events are strongly affected by xallarap.Comment: 69 Pages, 10 Figures, 24 Tables, Submitted to Ap

Experimental and numerical study on the performance of the smooth-land labyrinth seal

In turbomachinery the secondary flow system includes flow phenomena occurring outside the main channel, where the gaseous medium performs work on blades. Secondary air distribution constitutes a very complex and closely interrelated system that affects most of the gas turbine components. One of the most important examples of the secondary flow is leakage occurring in seals, e.g. at the rotor and stator tips, on the shaft or on the sides of the blade rim. Owing to its simplicity, low price, easy maintenance and high temperature capability, the labyrinth seal is a prime sealing solution that may be selected from numerous types of sealing structures applied in turbomachinery. For this reason, an experimental study of this particular structure has been carried out. The paper presents leakage performance of the smooth-land labyrinth seal