Supported nickel catalyst from hydroxycarbonate of nickel and aluminium

The hydroxycarbonate of nickel and aluminium (Ni/ Al = 3) with a hydrotalcite-like structure is an outstanding precursor of the active component of supported nickel catalysts. Good mechanical strength and suitable nickel content of these catalysts, which are necessary for practical applications, can be achieved by mechanical mixing of this compound with an additional support. The catalyst prepared from a mixture of 56.5 wt-% of nickel-aluminium hydroxycarbonate and 43.5 wt-% of γ-alumina was proven to have a stable catalytic activity in the methanation reaction at 2 MPa and 800 K.     

Portosystemic shunt in Budd-Chiari syndrome: long-term survival and factors affecting shunt patency in 25 patients in Western countries

BACKGROUND: In Budd-Chiari syndrome (BCS) treated by portosystemic shunt, postoperative shunt thrombosis is associated with high morbidity and mortality rates. The aim of this study was to determine factors associated with shunt thrombosis. METHODS: From 1985 to 1991, 25 patients underwent portosystemic shunt for BCS. According to the patency of the shunt during the postoperative period and follow-up, patients were divided into two groups including 17 patients with patent shunt and 8 (32%) with shunt thrombosis. RESULTS: In patients with patent shunt, actuarial survival rate at 5 years was 87% versus 38% in patients with shunt thrombosis (p < 0.05). Duration of symptoms before operation was higher in patients with shunt thrombosis than in patients with patent shunt (315 +/- 483 vs 109 +/- 168 days, p < 0.05). In patients with patent shunt, extensive fibrosis or cirrhosis was observed in 3 of 17 (18%) versus in 5 of 8 (63%) of patients with shunt thrombosis (p < 0.05). Shunt thrombosis was observed in 3 of 3 patients (100%) with the combination of myeloproliferative disorder, duration of symptoms more than 100 days, and cirrhosis versus 0 of 6 (0%) patients without this combination (p < 0.05). CONCLUSIONS: In acute form of BCS (with short history of the disease and absence of extensive fibrosis or cirrhosis), early portal decompression is mandatory, with low risk of shunt thrombosis and good long-term results. In chronic form of BCS, the risk of shunt thrombosis is high and long-term results are bad; in these patients, orthotopic liver transplantation must be considered.     

Grey-level hit-or-miss transforms—part II: Application to angiographic image processing

The <em>hit-or-miss transform</em> (HMT) is a fundamental operation on binary images, widely used since 40 years. As it is not increasing, its extension to grey-level images is not straightforward, and very few authors have considered it. Moreover, despite its potential usefulness, very few applications of the grey-level HMT have been proposed until now. Part I of this paper [B. Naegel, N. Passat, C. Ronse, Grey-level hit-or-miss transforms—part I: unified theory. Pattern Recogn., in press doi:10.1016/j.patcog.2006.06.004] was devoted to the description of a theory enabling to unify the main definitions of the grey-level HMT, mainly proposed by Ronse and Soille, respectively. Part II of this paper, developed hereafter, deals with the applicative potential of the grey-level HMT, illustrated by its use for vessel segmentation from 3D angiographic data. Different HMT-based segmentation methods are then described and analysed, leading to concrete analysis techniques for brain and liver vessels, but also providing algorithmic strategies which could further be used for many other kinds of image processing applications.     

A new approach to predict ulcerative colitis activity through standard clinical–biological parameters using a robust neural network model

Neural Computing and Applications - Colonoscopy is the “gold” standard for evaluating disease activity in ulcerative colitis (UC). An important area of research is finding a...     

The stable topology for residuated lattices

The spectrum of a residuated lattice <em>L</em> is the set <em>Spec</em>(<em>L</em>) of all prime i-filters. It is well known that <em>Spec</em>(<em>L</em>) can be endowed with the spectral topology. The main scope of this paper is to introduce and study another topology on <em>Spec</em>(<em>L</em>),?the so called <em>stable topology</em>, which turns out to be coarser than the spectral one. With this and in view, we introduce the notions of <em>pure</em> i-filter for a residuated lattice and the notion of <em>normal</em> residuated lattice. So, we generalize to case of residuated lattice some results relative to <em>MV</em>-algebras (Belluce and Sessa in Quaest Math 23:269–277, <span class="a-plus-plus citation-ref citationid-c-r3">2000</span>; Cavaccini et?al. in Math Japonica 45(2):303–310, <span class="a-plus-plus citation-ref citationid-c-r6">1997</span>) or <em>BL</em>-algebras (Eslami and Haghani in Kybernetika 45:491–506, <span class="a-plus-plus citation-ref citationid-c-r13">2009</span>; Leustean in Central Eur J Math 1(3): 382–397, <span class="a-plus-plus citation-ref citationid-c-r20">2003</span>; Turunen and Sessa in Mult-Valued Log 6(1–2):229–249, <span class="a-plus-plus citation-ref citationid-c-r24">2001</span>).     

Oxidative dimerisation of propene to 1,5-hexadiene on Bi-Zn-O catalysts

The oxidative dimerisation of propene to 1,5-hexadiene has been investigated on Bi-Zn-O catalysts. The Bi<sub>48</sub>ZnO<sub>73</sub> phase, observed in the catalysts calcined at 700 ° C is an active and selective catalyst for the formation of 1,5-hexadiene. The best catalytic performance (1,5-hexadiene selectivity <img src="/content/q63581127352l0v7/xxlarge8776.gif" alt="ap" align="MIDDLE" BORDER="0"> 64%) has been obtained at 525 ° C, with a propene to oxygen ratio of 26, on a catalyst formed by Bi<sub>48</sub>ZnO<sub>73</sub> with a small excess of ZnO.     

Detecting Fixed Patterns in Chordal Graphs in Polynomial Time

The <span class="a-plus-plus emphasis type-small-caps">Contractibility</span> problem takes as input two graphs <em>G</em> and <em>H</em>, and the task is to decide whether <em>H</em> can be obtained from <em>G</em> by a sequence of edge contractions. The <span class="a-plus-plus emphasis type-small-caps">Induced Minor</span> and <span class="a-plus-plus emphasis type-small-caps">Induced Topological Minor</span> problems are similar, but the first allows both edge contractions and vertex deletions, whereas the latter allows only vertex deletions and vertex dissolutions. All three problems are <span class="a-plus-plus emphasis fontcategory-sans-serif">NP</span>-complete, even for certain <em>fixed</em> graphs <em>H</em>. We show that these problems can be solved in polynomial time for every fixed <em>H</em> when the input graph <em>G</em> is chordal. Our results can be considered tight, since these problems are known to be <span class="a-plus-plus emphasis fontcategory-sans-serif">W</span>[<span class="a-plus-plus emphasis fontcategory-sans-serif">1</span>]-hard on chordal graphs when parameterized by the size of <em>H</em>. To solve <span class="a-plus-plus emphasis type-small-caps">Contractibility</span> and <span class="a-plus-plus emphasis type-small-caps">Induced Minor</span>, we define and use a generalization of the classic <span class="a-plus-plus emphasis type-small-caps">Disjoint Paths</span> problem, where we require the vertices of each of the <em>k</em> paths to be chosen from a specified set. We prove that this variant is <span class="a-plus-plus emphasis fontcategory-sans-serif">NP</span>-complete even when <em>k</em>=2, but that it is polynomial-time solvable on chordal graphs for every fixed <em>k</em>. Our algorithm for <span class="a-plus-plus emphasis type-small-caps">Induced Topological Minor</span> is based on another generalization of <span class="a-plus-plus emphasis type-small-caps">Disjoint Paths</span> called <span class="a-plus-plus emphasis type-small-caps">Induced Disjoint Paths</span>, where the vertices from different paths may no longer be adjacent. We show that this problem, which is known to be <span class="a-plus-plus emphasis fontcategory-sans-serif">NP</span>-complete when <em>k</em>=2, can be solved in polynomial time on chordal graphs even when <em>k</em> is part of the input. Our results fit into the general framework of graph containment problems, where the aim is to decide whether a graph can be modified into another graph by a sequence of specified graph operations. Allowing combinations of the four well-known operations edge deletion, edge contraction, vertex deletion, and vertex dissolution results in the following ten containment relations: (induced) minor, (induced) topological minor, (induced) subgraph, (induced) spanning subgraph, dissolution, and contraction. Our results, combined with existing results, settle the complexity of each of the ten corresponding containment problems on chordal graphs.     

A new variety of low-linolenic rapeseed oil; Characteristics and room-odor tests

Two Canadian rapeseed oils, “Westar” and “low-linolenic”, supplied by the Canola Council were studied and compared with a French rapeseed. The linolenic acid content of the low-linolenic variety is about 3%. This drop in the C18∶3 is completely compensated for by an increase in the C18∶2. Seventy-two percent of the triglycerides with at least one linolenic chain disappeared. A strong increase in the OOL and OLL was observed. The room-odor tests showed that the “low-linolenic” had a significantly higher odor score than the French rapeseed and the “Westar”, both of these being very similar. A fruity odor dominated in the “low-linolenic”, and the fishy painty odors were particularly reduced.     

Effect of temperature on activity and selectivity of carbon supported Mo sulfide in simultaneous hydrodenitrogenation of pyridine and hydrodesulfurization of thiophene

Activity and selectivity of carbon supported Mo catalyst was tested in parallel hydrodenitrogenation (HDN) of pyridine and hydrodesulfurization (HDS) of thiophene in the temperature range 260–350 °C at 2 MPa of hydrogen pressure and compared with that of commercial NiMo-alumina catalyst Shell 324. The main advantages of carbon supported Mo sulfide over commercial NiMo catalyst can be summarized as follows: the markedly higher HDN and better HDS activities normalized to moles of active metals, the lower content of piperidine in the reaction products and the distinctly better selectivity towards HDN reaction.