Recognizing misplacement of a dialysis catheter in the azygos vein

Uneventful central venous catheterization for hemodialysis patients may not always result in a correct tip position. A case of inadvertent cannulation of the azygos vein is described. Radiographic features for its early recognition are emphasized and mechanisms related with azygos unintended catheterization are discussed.     

A multi-objective GRASP for partial classification

Metaheuristic algorithms have been used successfully in a number of data mining contexts and specifically in the production of classification rules. Classification rules describe a class of interest or a subset of this class, and as such may also be used as an aid in prediction. The production and selection of classification rules for a particular class of the database is often referred to as partial classification. Since partial classification rules are often evaluated according to a number of conflicting objectives, the generation of such rules is a task that is well suited to a multi-objective (MO) metaheuristic approach. In this paper we discuss how to adapt well known MO algorithms for the task of partial classification. Additionally, we introduce a new MO algorithm for this task based on a greedy randomized adaptive search procedure (GRASP). GRASP has been applied to a number of problems in combinatorial optimization, but it has very seldom been used in a MO setting, and generally only through repeated optimization of single objective problems, using either linear combinations of the objectives or additional constraints. The approach presented takes advantage of some specific characteristics of the data mining problem being solved, allowing for the very effective construction of a set of solutions that form the starting point for the local search phase of the GRASP. The resulting algorithm is guided solely by the concepts of dominance and Pareto-optimality. We present experimental results for our partial classification GRASP and other MO metaheuristics. These show that such algorithms are generally very well suited to this data mining task and furthermore, the GRASP brings additional efficiency to the search for partial classification rules.     

Surface hardness behaviour of Ti-Al-Mo alloys

The microhardness characteristics of various micro-constituents formed in the Ti-Al-Mo alloys have been investigated. Four alloys having compositions, Ti-40Al-2Mo, Ti-42Al-2Mo, Ti-40Al-6Mo and Ti-42Al-6Mo, have been chosen for this purpose. All of these were heat treated at 1300°C and 1400°C for 1 h and water quenched. All the specimens after above heat treatments have displayed load independent Vickers hardness values (VHN) around 300 g of applied load. The average surface hardness characteristic of the alloys is largely found to be dictated by the phases that are present. The microstructural specific VHN values vary between 600 and 750. The indentation behaviour, however, is governed by the morphologies and length scales of microstructures. The most remarkable finding of the present study pertains to the formation of shear bands around the periphery of the indenter for a finer basket weave microstructure in the Ti-40Al-2Mo. The cluster of finely located slip steps was clearly seen. Such a report is lacking in literature in this class of alloys.     

The lack of reproducibility of different distillation techniques and its impact on pear spirit composition

We analysed the impact of operation variability on the composition of pear spirits obtained with a Charentais alembic and a packed distillation column. Lack of reproducibility significantly affected the spirits’ compositions, with batch distillation columns more difficult to operate reproducibly vs. traditional alembics. The composition of column distilled spirits differed more in esters, such as ethyl octanoate, ethyl decanoate and ethyl palmitate. In turn, alembic spirit compositions differed more in acetaldehyde and acetal. Moreover, column distilled spirits contained four times more esters, 20% more higher alcohols, 40% less acetaldehyde and 10% less methanol than alembic spirits. Spirits distilled with a rectification column were more concentrated in ethanol than alembic distilled spirits, although both distillation systems recovered the same amount of ethanol in the heart fraction.     

A closed-form solution for a two-server heterogeneous retrial queue with threshold policy

In this paper, we reconsider a two-server heterogeneous retrial queue with threshold policy. However, the computation time with the existing method is prohibitively large for certain values of the threshold parameter. Applying the spectral expansion method, we derive a closed-form expression for the eigenvalues and eigenvectors matrix that are needed to determine the steady-state distribution of a quasi-birth-death process describing the queue. As a result, the computation time for the performance measures does not depend on the threshold parameter.     

The Potential of Proteins for Producing Food Packaging Materials: A Review

The problems associated with obtaining conventional plastic materials and with their accumulation have led to a constant search for new materials derived from renewable sources. Materials made from proteins stand out among them all because of the many ways in which they can be modified enzymatically, chemically or physically, giving rise to materials with improved physicochemical properties that are adjustable to each specific application. This paper reviews the state of the art with regard to the use of proteins for the manufacture of packaging materials, including: the main protein sources that have been used; manufacturing methods (coating on conventional materials, thermoforming, extrusion), with special emphasis on materials made by extrusion; possible strategies for improving the physicochemical properties of the materials and the main future prospects and limitations of materials of this kind.     

Amphiphilic 2‐ethyl hexyl methacrylate‐b‐N,N′‐dimethylacrylamide diblock copolymer monolayer behaviour at the air − water interface†

The surface activities of two amphiphilic diblock copolymers containing 2‐ethyl hexyl methacrylate‐b‐N,N′‐dimethylacrylamide (EHMA‐b‐DMA) possessing hydrophobic segments of different chain lengths were studied. Toward this end, surface pressure?area (π?A) isotherms, static and dynamic elasticities and the ν exponent of the excluded volume of polymers forming monolayers at the air?water interface were measured. The degree of hydrophobicity of the diblock copolymers was estimated by determining their surface energy values from contact angle measurements. The morphology of the monolayer at different surface pressures was studied by Brewster angle microscopy. Both copolymers were observed to form stable and elastic monolayers, and their collapse was observed to occur at similar surface pressures. Langmuir?Blodgett films were successfully deposited onto mica and silicon wafers and analysed by atomic force microscopy. © 2014 Society of Chemical Industry