bluuebunny/crossref_metadata_2025 huggingface dataset:
Critical Aspects In Surfactant Flooding Procedure At Mixed-wet Conditions
Authors: Fjelde Ingebret , Lohne Arild , Abeysinghe Kumuduni Prasangika
Published: May 2015

The theory and procedures for surfactant flooding were developed for water-wet sandstone, but many sandstone reservoirs are today characterized as mixed-wet. The objective for the study was to carry out critical investigation of experimental methods used to evaluate the potential for surfactant flooding in mixed-wet sandstone reservoirs. Water flooding and surfactant flooding experiments were performed in mixed-wet Berea outcrop sandstone, and in reservoir sandstone rock.

During water flooding long tail-end production was observed for both the mixed-wet Berea and reservoir rock. The relative permeability (kr)-curves estimated by history matching were similar for these rocks. Since kr of oil (kro) is low at higher water saturations, the residual oil saturation (Sor) will not be reached with realistic injection volumes. The remaining oil saturation (ROS) was both in the water floods and surfactant floods strongly dependent on the volumes injected. The focus should therefore be on the alteration of kr-curves by the surfactant rather than reduction of Sor.

Solubilization of oil into the surfactant phase is challenging in relative permeability experiments at mixed-wet conditions. When injected surfactant solution was not in equilibrium with the oil, it was not possible to correct the oil production for the solubilization because the surfactant phase was not in equilibrium with the remaining oil in the rock. The estimated kr-curves should therefore have been at higher water-saturations. The uncertainty related to solubilization of oil can be reduced by flooding with surfactant systems with equilibrium between the phases.

In mixed-wet rock having negative Pc at higher water saturation (Sw), capillary forces will act to reduce the oil production rate. The effect increases in shorter core plugs and at lower injection rates and it also seems to be more important if displaced oil phase has low viscosity. It is recommended to always evaluate capillary end effects when dealing with mixed-wet rock material to secure that additional oil production due to reduced end effects is not included in the surfactant flooding potential.

Simulation of surfactant flooding in mixed-wet formations require a fair representation of the capillary number (Nc) dependent kr curvature. It is demonstrated that this is possible using a simple surfactant model available in commercial simulators and a practical cut-off value for Sor at low Nc in the model.

Recommendations are given on how to secure the quality of surfactant flooding experiments and the interpretation of these experiments to allow robust data for scaling of the laboratory results to field.
On the Relation of Interaction Semantics to Continuations and Defunctionalization
Authors: Schöpp Ulrich
Published: May 2015

In game semantics and related approaches to programming language semantics,
programs are modelled by interaction dialogues. Such models have recently been
used in the design of new compilation methods, e.g. for hardware synthesis or
for programming with sublinear space. This paper relates such semantically
motivated non-standard compilation methods to more standard techniques in the
compilation of functional programming languages, namely continuation passing
and defunctionalization. We first show for the linear {\lambda}-calculus that
interpretation in a model of computation by interaction can be described as a
call-by-name CPS-translation followed by a defunctionalization procedure that
takes into account control-flow information. We then establish a relation
between these two compilation methods for the simply-typed {\lambda}-calculus
and end by considering recursion.
On the strictness of the quantifier structure hierarchy in first-order logic
Authors: He Yuguo
Published: May 2015

We study a natural hierarchy in first-order logic, namely the quantifier
structure hierarchy, which gives a systematic classification of first-order
formulas based on structural quantifier resource. We define a variant of
Ehrenfeucht-Fraisse games that characterizes quantifier classes and use it to
prove that this hierarchy is strict over finite structures, using strategy
compositions. Moreover, we prove that this hierarchy is strict even over
ordered finite structures, which is interesting in the context of descriptive
complexity.
A Hoare logic for the coinductive trace-based big-step semantics of While
Authors: Nakata Keiko , Uustalu Tarmo
Published: May 2015

In search for a foundational framework for reasoning about observable
behavior of programs that may not terminate, we have previously devised a
trace-based big-step semantics for While. In this semantics, both traces and
evaluation (relating initial states of program runs to traces they produce) are
defined coinductively. On terminating runs, this semantics agrees with the
standard inductive state-based semantics. Here we present a Hoare logic
counterpart of our coinductive trace-based semantics and prove it sound and
complete. Our logic subsumes the standard partial-correctness state-based Hoare
logic as well as the total-correctness variation: they are embeddable. In the
converse direction, projections can be constructed: a derivation of a Hoare
triple in our trace-based logic can be translated into a derivation in the
state-based logic of a translated, weaker Hoare triple. Since we work with a
constructive underlying logic, the range of program properties we can reason
about has a fine structure; in particular, we can distinguish between
termination and nondivergence, e.g., unbounded classically total search fails
to be terminating, but is nonetheless nondivergent. Our meta-theory is entirely
constructive as well, and we have formalized it in Coq.
The Computational Complexity of Propositional Cirquent Calculus
Authors: Bauer Matthew Steven
Published: May 2015

Introduced in 2006 by Japaridze, cirquent calculus is a refinement of sequent
calculus. The advent of cirquent calculus arose from the need for a deductive
system with a more explicit ability to reason about resources. Unlike the more
traditional proof-theoretic approaches that manipulate tree-like objects
(formulas, sequents, etc.), cirquent calculus is based on circuit-style
structures called cirquents, in which different "peer" (sibling, cousin, etc.)
substructures may share components. It is this resource sharing mechanism to
which cirquent calculus owes its novelty (and its virtues). From its inception,
cirquent calculus has been paired with an abstract resource semantics. This
semantics allows for reasoning about the interaction between a resource
provider and a resource user, where resources are understood in the their most
general and intuitive sense. Interpreting resources in a more restricted
computational sense has made cirquent calculus instrumental in axiomatizing
various fundamental fragments of Computability Logic, a formal theory of
(interactive) computability. The so-called "classical" rules of cirquent
calculus, in the absence of the particularly troublesome contraction rule,
produce a sound and complete system CL5 for Computability Logic. In this paper,
we investigate the computational complexity of CL5, showing it is
$\Sigma_2^p$-complete. We also show that CL5 without the duplication rule has
polynomial size proofs and is NP-complete.
Positive Inductive-Recursive Definitions
Authors: Ghani Neil , Forsberg Fredrik Nordvall , Malatesta Lorenzo
Published: May 2015

A new theory of data types which allows for the definition of types as
initial algebras of certain functors Fam(C) -> Fam(C) is presented. This
theory, which we call positive inductive-recursive definitions, is a
generalisation of Dybjer and Setzer's theory of inductive-recursive definitions
within which C had to be discrete -- our work can therefore be seen as lifting
this restriction. This is a substantial endeavour as we need to not only
introduce a type of codes for such data types (as in Dybjer and Setzer's work),
but also a type of morphisms between such codes (which was not needed in Dybjer
and Setzer's development). We show how these codes are interpreted as functors
on Fam(C) and how these morphisms of codes are interpreted as natural
transformations between such functors. We then give an application of positive
inductive-recursive definitions to the theory of nested data types and we give
concrete examples of recursive functions defined on universes by using their
elimination principle. Finally we justify the existence of positive
inductive-recursive definitions by adapting Dybjer and Setzer's set-theoretic
model to our setting.
Bialgebraic Semantics for Logic Programming
Authors: Bonchi Filippo , Zanasi Fabio
Published: May 2015

Bialgebrae provide an abstract framework encompassing the semantics of
different kinds of computational models. In this paper we propose a bialgebraic
approach to the semantics of logic programming. Our methodology is to study
logic programs as reactive systems and exploit abstract techniques developed in
that setting. First we use saturation to model the operational semantics of
logic programs as coalgebrae on presheaves. Then, we make explicit the
underlying algebraic structure by using bialgebrae on presheaves. The resulting
semantics turns out to be compositional with respect to conjunction and term
substitution. Also, it encodes a parallel model of computation, whose soundness
is guaranteed by a built-in notion of synchronisation between different
threads.
Modelling MAC-Layer Communications in Wireless Systems
Authors: Cerone Andrea , Hennessy Matthew , Merro Massimo
Published: May 2015

We present a timed process calculus for modelling wireless networks in which
individual stations broadcast and receive messages; moreover the broadcasts are
subject to collisions. Based on a reduction semantics for the calculus we
define a contextual equivalence to compare the external behaviour of such
wireless networks. Further, we construct an extensional LTS (labelled
transition system) which models the activities of stations that can be directly
observed by the external environment. Standard bisimulations in this LTS
provide a sound proof method for proving systems contextually equivalence. We
illustrate the usefulness of the proof methodology by a series of examples.
Finally we show that this proof method is also complete, for a large class of
systems.
Simulation in the Call-by-Need Lambda-Calculus with Letrec, Case, Constructors, and Seq
Authors: Schmidt-Schauß Manfred , Sabel David , Machkasova Elena
Published: May 2015

This paper shows equivalence of several versions of applicative similarity
and contextual approximation, and hence also of applicative bisimilarity and
contextual equivalence, in LR, the deterministic call-by-need lambda calculus
with letrec extended by data constructors, case-expressions and Haskell's
seq-operator. LR models an untyped version of the core language of Haskell. The
use of bisimilarities simplifies equivalence proofs in calculi and opens a way
for more convenient correctness proofs for program transformations. The proof
is by a fully abstract and surjective transfer into a call-by-name calculus,
which is an extension of Abramsky's lazy lambda calculus. In the latter
calculus equivalence of our similarities and contextual approximation can be
shown by Howe's method. Similarity is transferred back to LR on the basis of an
inductively defined similarity. The translation from the call-by-need letrec
calculus into the extended call-by-name lambda calculus is the composition of
two translations. The first translation replaces the call-by-need strategy by a
call-by-name strategy and its correctness is shown by exploiting infinite trees
which emerge by unfolding the letrec expressions. The second translation
encodes letrec-expressions by using multi-fixpoint combinators and its
correctness is shown syntactically by comparing reductions of both calculi. A
further result of this paper is an isomorphism between the mentioned calculi,
which is also an identity on letrec-free expressions.
Eigenvalue asymptotics for the Schrödinger operator with a matrix potential in a single resonance domain
Authors: Karakiliç Sedef , Akduman Setenay
Published: May 2015

We consider a Schr?dinger Operator with a matrix potential defined in Lm2 (F)
by the differential expression L(?(x)) = (-? + V(x))?(x) and the Neumann
boundary condition, where F is the d dimensional rectangle and V is a martix
potential, m ? 2, d ? 2. We obtain the asymptotic formulas of arbitrary order
for the single resonance eigenvalues of the Schr?dinger operator in Lm2(F).
Covering groupoids of categorical rings
Authors: Mucuk Osman , Demir Serap
Published: May 2015

A categorical group is a kind of categorization of group and similarly a
categorical ring is a categorization of ring. For a topological group X, the
fundamental groupoid ?X is a group object in the category of groupoids,
which is also called in literature group-groupoid or 2-group. If X is a path
connected topological group which has a simply connected cover, then the
category of covering groups of X and the category of covering groupoids of
?X are equivalent. Recently it was proved that if (X, x0) is an H-group,
then the fundamental groupoid ?X is a categorical group and the category of
the covering spaces of (X, x0) is equivalent to the category of covering
groupoids of the categorical group ?X. The purpose of this paper is to
present similar results for rings and categorical rings.
The unions of dense metrizable subspaces with certain local properties
Authors: Arhangel’skii A.V. , Tokgöz S.
Published: May 2015

Many important examples of topological spaces can be represented as a union
of a finite or countable collection of metrizable subspaces. However, it is
far from clear which spaces in general can be obtained in this way.
Especially interesting is the case when the subspaces are dense in the union.
We present below several results in this direction. In particular, we show
that if a Tychonoff space X is the union of a countable family of dense
metrizable locally compact subspaces, then X itself is metrizable and locally
compact. We also prove a similar result for metrizable locally separable
spaces. Notice in this connection that the union of two dense metrizable
subspaces needn?t be metrizable. Indeed, this is witnessed by a well-known
space constructed by R.W. Heath.
Characterization of topologically transitive attractors for analytic plane flows
Authors: Shoptrajanov Martin , Shekutkovski Nikita
Published: May 2015

We give necessary conditions for a set to be topologically transitive
attractor of an analytic plane flow using topological characterization of
?-limit sets and the concept of upper semi-continuity of multi valued maps.
Some bounds for the pseudocharacter of the space Cα (X,Y)
Authors: Vural Çetin
Published: May 2015

Let C? (X,Y) be the set of all continuous functions from X into Y endowed
with the set-open topology where ? is a hereditarily closed, compact network
on X. We obtain that: i-) ? (f,C? (X,Y)? w?c (X)? sup A?? (?(f(A),Y))?
sup A?? (w(f(A)))) ii-) ? (f,C? (X,Y)? w?c (X)? pswe(f(X),Y).
Some remarks on incomplete gamma type function γ*(α, x_)
Authors: Özcağ Emin , Egeb İnci
Published: May 2015

The incomplete gamma type function ?*(?, x_) is defined as locally summable
function on the real line for ?>0 by ?*(?,x_) = {?x0 |u|?-1 e-u du, x?0;
0, x > 0 = ?-x_0 |u|?-1 e-u du the integral divergining ? ? 0
and by using the recurrence relation ?*(? + 1,x_) = -??*(?,x_) - x?_ e-x the definition of ?*(?, x_) can be extended to the negative non-integer values of ?. Recently the authors [8] defined ?*(-m, x_) for m = 0, 1, 2,... . In this paper we define the derivatives of the incomplete gamma type function ?*(?, x_) as a distribution for all ? < 0.
Countable dense homogeneous rimcompact spaces and local connectivity
Authors: Milla van
Published: May 2015

We prove that every nonmeager connected Countable Dense Homogeneous space is
locally connected under some additional mild connectivity assumption. As a
corollary we obtain that every Countable Dense Homogeneous connected
rimcompact space is locally connected.
Unsteady flow around a two-dimensional section of a vertical axis turbine for tidal stream energy conversion
Authors: Jung Hyun Ju , Lee Ju Hyun , Rliee Shin Hyung , Song Museok , Hyun Beom-Soo
Published: May 2015

The two-dimensional unsteady flow around a vertical axis turbine for tidal stream energy' conversion was investigated using a computational fluid dynamics tool solving the Reynolds-Averaged Navier-Stokes equations. The geometry' of the turbine blade section was NACA653-01S airfoil. The computational analysis was done at several different angles of attack and the results were compared with the corresponding experimental data for validation and calibration. Simulations were then carried out for the two-dimensional cross section of a vertical axis turbine. The simulation results demonstrated the usefulness of the method for the typical unsteady flows around vertical axis turbines. The optimum turbine efficiency was achieved for carefully selected combinations of the number of blades and tip speed ratios.
In vitro anthelmintic activity of Heliotropium indicum, Senna fistula and Spigelia anthelmia used as worm expeller in South West Nigeria
Authors: Sobiyi Oluwakemi K. , Ashafa A.O. Tom
Published: May 2015

The anthelmintic potential of Heliotropium indicum, Senna fistula and Spigelia anthelmia were investigated using nematodes larvae from sheep and adult earthworms in order to justify the folkloric claim of the plants as worm expeller in south west of Nigeria. The acetone, ethanol, hydro-alcohol and distilled water extracts showed dose-dependent anthelmintic activities at the different concentrations (0.25, 0.50, 1.0 mg/ml) when tested against nematodes larvae. The order of anthelmintic effect for the plants was H. indicum> S. fistula> S. anthelmia. Acetone and ethanol extracts of the three plants showed the most effective activity (100% mortality) against adult earth worm (Pheretima posthuma) after 30 min of exposure The reference standard drug (Vermox®) showed less effectiveness compared to the medicinal plants used in the study. Overall, the study indicates that Heliotropium indicum, Senna fistula and Spigelia anthelmia are potential anthelmintic herbal drugs, which in turn validates the use of the three species as worm expellers by the Yorubas tribe of South West Nigeria.
TLC-Direct Bioautography as a High Throughput Method for Detection of Antimicrobials in Plants
Authors: Choma Irena , Jesionek Wioleta
Published: May 2015

The richness of bioactive compounds in plant materials encourages continuous development of separation methods and bioassays for their isolation and identification. Thin-layer chromatography-direct bioautography links separation on the adsorbent layer with biological tests performed directly on it. Therefore, the method is very convenient for searching plant constituents with biological activity, such as antibiotics. Test bacteria grow directly on a plate surface excluding places where antibacterials are located. They can be detected with reagents converted by living bacteria. TLC-DB is a high throughput method enabling analyses of many samples in parallel and the comparison of their activity. Both screening and semi-quantitative analysis is possible. The targeted compounds can be identified using spectroscopic methods, mostly mass spectrometry, that can be performed directly on a TLC plate. This paper discusses all above mentioned aspects of TLC-DB, illustrating them with literature, schemes and our own results.
A Methodology for Assessing Islanding of Microgrids: Between Utility Dependence and Off-Grid Systems
Authors: Colmenar-Santos Antonio , De Palacio Carlos , Enríquez-García Lorenzo , López-Rey África
Published: May 2015

This paper presents a novel methodology for assessing islanding microgrids from the economical and functional perspective, for various stakeholders. The paper proposes the triggers for competitive deployment of microgeneration, storage, microgrid islanding, the market conditions that apply, and discusses the future tendencies and the policy recommendations to foster microgrid benefits. The validation of the proposed scheme is based on real market cases, where the triggers for autogeneration and islanding microgrids are present. Additionally, the new concept of grid independence cycle is presented and analyzed. The policy implications of a situation where grid consumption reduction leads to higher energy prices are presented and discussed. The paper concludes with a summary of prioritized technical and regulatory recommendations, proposed as a result of the assessment.
Adventitial Tertiary Lymphoid Organs as Potential Source of MicroRNA Biomarkers for Abdominal Aortic Aneurysm
Authors: Spear Rafaelle , Boytard Ludovic , Blervaque Renaud , Chwastyniak Maggy , Hot David , Vanhoutte Jonathan , Staels Bart , Lemoine Yves , Lamblin Nicolas , Pruvot François-René , Haulon Stephan , Amouyel Philippe , Pinet Florence
Published: May 2015

Abdominal aortic aneurysm (AAA) is an inflammatory disease associated with marked changes in the cellular composition of the aortic wall. This study aims to identify microRNA (miRNA) expression in aneurysmal inflammatory cells isolated by laser microdissection from human tissue samples. The distribution of inflammatory cells (neutrophils, B and T lymphocytes, mast cells) was evaluated in human AAA biopsies. We observed in half of the samples that adventitial tertiary lymphoid organs (ATLOs) with a thickness from 0.5 to 2 mm were located exclusively in the adventitia. Out of the 850 miRNA that were screened by microarray in isolated ATLOs (n = 2), 164 miRNAs were detected in ATLOs. The three miRNAs (miR-15a-3p, miR-30a-5p and miR-489-3p) with the highest expression levels were chosen and their expression quantified by RT-PCR in isolated ATLOs (n = 4), M1 (n = 2) and M2 macrophages (n = 2) and entire aneurysmal biopsies (n = 3). Except for the miR-30a-5p, a similar modulation was found in ATLOs and the two subtypes of macrophages. The modulated miRNAs were then evaluated in the plasma of AAA patients for their potential as AAA biomarkers. Our data emphasize the potential of miR-15a-3p and miR-30a-5p as biomarkers of AAA but also as triggers of ATLO evolution. Further investigations will be required to evaluate their targets in order to better understand AAA pathophysiology.
Immunohistochemical Analysis of Paraoxonases and Chemokines in Arteries of Patients with Peripheral Artery Disease
Authors: Hernández-Aguilera Anna , Sepúlveda Julio , Rodríguez-Gallego Esther , Guirro Maria , García-Heredia Anabel , Cabré Noemí , Luciano-Mateo Fedra , Fort-Gallifa Isabel , Martín-Paredero Vicente , Joven Jorge , Camps Jordi
Published: May 2015

Oxidative damage to lipids and lipoproteins is implicated in the development of atherosclerotic vascular diseases, including peripheral artery disease (PAD). The paraoxonases (PON) are a group of antioxidant enzymes, termed PON1, PON2, and PON3 that protect lipoproteins and cells from peroxidation and, as such, may be involved in protection against the atherosclerosis process. PON1 inhibits the production of chemokine (C–C motif) ligand 2 (CCL2) in endothelial cells incubated with oxidized lipoproteins. PON1 and CCL2 are ubiquitously distributed in tissues, and this suggests a joint localization and combined systemic effect. The aim of the present study has been to analyze the quantitative immunohistochemical localization of PON1, PON3, CCL2 and CCL2 receptors in a series of patients with severe PAD. Portions of femoral and/or popliteal arteries from 66 patients with PAD were obtained during surgical procedures for infra-inguinal limb revascularization. We used eight normal arteries from donors as controls. PON1 and PON3, CCL2 and the chemokine-binding protein 2, and Duffy antigen/chemokine receptor, were increased in PAD patients. There were no significant changes in C–C chemokine receptor type 2. Our findings suggest that paraoxonases and chemokines play an important role in the development and progression of atherosclerosis in peripheral artery disease.
Correlation between Patient-Reported Symptoms and Ankle-Brachial Index after Revascularization for Peripheral Arterial Disease
Authors: Je Hyung , Kim Bo , Cho Kyoung , Jang Jae , Park Yong , Spertus John
Published: May 2015

Improvement in quality of life (QoL) is a primary treatment goal for patients with peripheral arterial disease (PAD). The current study aimed to quantify improvement in the health status of PAD patients following peripheral revascularization using the peripheral artery questionnaire (PAQ) and ankle-brachial index (ABI), and to evaluate possible correlation between the two methods. The PAQ and ABI were assessed in 149 symptomatic PAD patients before, and three months after peripheral revascularization. Mean PAQ summary scores improved significantly three months after revascularization (+49.3 ± 15 points, p < 0.001). PAQ scores relating to patient symptoms showed the largest improvement following revascularization. The smallest increases were seen in reported treatment satisfaction (all p’s < 0.001). As expected the ABI of treated limbs showed significant improvement post-revascularization (p < 0.001). ABI after revascularization correlated with patient-reported changes in the physical function and QoL domains of the PAQ. Twenty-two percent of PAD patients were identified as having a poor response to revascularization (increase in ABI < 0.15). Interestingly, poor responders reported improvement in symptoms on the PAQ, although this was less marked than in patients with an increase in ABI > 0.15 following revascularization. In conclusion, data from the current study suggest a significant correlation between improvement in patient-reported outcomes assessed by PAQ and ABI in symptomatic PAD patients undergoing peripheral revascularization.
The Effects of Different Fine Recycled Concrete Aggregates on the Properties of Mortar
Authors: Fan Cheng-Chih , Huang Ran , Hwang Howard , Chao Sao-Jeng
Published: May 2015

The practical use of recycled concrete aggregate produced by crushing concrete waste reduces the consumption of natural aggregate and the amount of concrete waste that ends up in landfills. This study investigated two methods used in the production of fine recycled concrete aggregate: (1) a method that produces fine as well as coarse aggregate, and (2) a method that produces only fine aggregate. Mortar specimens were tested using a variety of mix proportions to determine how the characteristics of fine recycled concrete aggregate affect the physical and mechanical properties of the resulting mortars. Our results demonstrate the superiority of mortar produced using aggregate produced using the second of the two methods. Nonetheless, far more energy is required to render concrete into fine aggregate than is required to produce coarse as well as fine aggregate simultaneously. Thus, the performance benefits of using only fine recycled concrete aggregate must be balanced against the increased impact on the environment.
Antidiabetic Activity of Differently Regioselective Chitosan Sulfates in Alloxan-Induced Diabetic Rats
Authors: Xing Ronge , He Xiaofei , Liu Song , Yu Huahua , Qin Yukun , Chen Xiaolin , Li Kecheng , Li Rongfeng , Li Pengcheng
Published: May 2015

The present study investigated and compared the hypoglycemic activity of differently regioselective chitosan sulfates in alloxan-induced diabetic rats. Compared with the normal control rats, significantly higher blood glucose levels were observed in the alloxan-induced diabetic rats. The differently regioselective chitosan sulfates exhibited hypoglycemic activities at different doses and intervals, especially 3-O-sulfochitosan (3-S). The major results are as follows. First, 3,6-di-O-sulfochitosan and 3-O-sulfochitosan exhibited more significant hypoglycemic activities than 2-N-3, 6-di-O-sulfochitosan and 6-O-sulfochitosan. Moreover, 3-S-treated rats showed a more significant reduction of blood glucose levels than those treated by 3,6-di-O-sulfochitosan. These results indicated that –OSO3− at the C3-position of chitosan is a key active site. Second, 3-S significantly reduced the blood glucose levels and regulated the glucose tolerance effect in the experimental rats. Third, treatment with 3-S significantly increased the plasma insulin levels in the experimental diabetic rats. A noticeable hypoglycemic activity of 3-S in the alloxan-induced diabetic rats was shown. Clinical trials are required in the future to confirm the utility of 3-S.
Effect of COD:SO4 2− Ratio, HRT and Linoleic Acid Concentration on Mesophilic Sulfate Reduction: Reactor Performance and Microbial Population Dynamics
Authors: Moon Chungman , Singh Rajesh , Veeravalli Sathyanarayan , Shanmugam Saravanan , Chaganti Subba , Lalman Jerald , Heath Daniel
Published: May 2015

Biological sulfate (SO42−) reduction was examined in anaerobic sequential batch reactors (ASBRs) operated under different hydraulic retention times (HRTs) ranging from 12 to 36 h and COD (Chemical Oxygen Demand)/SO42−) ratios of 2.4, 1.6 and 0.8. Competition between SO42− reducing bacteria (SRBs), methane producing archaea (MPAs) and homoacetogens (HACs) was examined in controls and cultures treated with linoleic acid (LA). The ASBR performance was influenced by the COD/SO42− ratio in control cultures with a SO42− reduction of 87% at a COD/SO42− ratio of 0.8. At a 12 h HRT, in both control and LA treated cultures, greater than 75% SO42− removal was observed under all the conditions examined. In control reactors operating at a 36 h HRT, high levels of MPAs belonging to Methanobacteriales and Methanosarcinales were detected; however, in comparison, under low COD/SO42− ratio and with decreasing HRT conditions, a relative increase in SRBs belonging to Desulfovibrio and Desulfatibacillum was observed. Adding 0.5 g·L−1 LA suppressed Methanobacteriales, while increasing the LA concentration to 1 g·L−1 completely suppressed MPAs with a relative increase in SRBs. HACs belonging to Bacteroidetes were observed in the control and in cultures operated at 12 h HRT with a COD/SO42− ratio of 1.6 and fed 0.5 g·L−1 LA; however, with all other LA levels (0.5 and 1.0 g·L−1) and HRTs (12, 24 and 36 h), HACs were not detected.
La difficile mutation des transports maritimes dans la C.E.I. (The difficult change of maritime transports in the C.I.S.)
Authors: Thorez Pierre
Published: May 2015

Résumé. - Le démantèlement du territoire soviétique et le nouvel environnement économique bouleversent le fonctionnement des transports maritimes. Les structures ont été morcelées. Après une phase de repli, les ports cherchent à reconquérir leurs arrière-pays, certains avec succès. Les armements affrontent plus difficilement la concurrence. La flotte se rétracte par vente de navires et immatriculations sous pavillon de complaisance. Les équipages s'embauchent sur le marché international.
La Russie est-elle encore une grande puissance maritime ? (Is still Russia a great maritime power ?)
Authors: Vigarié André
Published: May 2015

Résumé. - Les événements marquant la fin de l'URSS ont eu de profondes répercussions sur les aptitudes de la nouvelle Russie à gérer ses problèmes maritimes : elle a hérité d'une puissance sur mer qui fut considérable, mais transmise à une Russie très sensiblement affaiblie par la partition territoriale et diverses difficultés économiques et administratives. On cherche à faire le point pour la flotte de commerce et aussi pour la flotte militaire, en montrant que l'une et l'autre, malgré bien des interrogations, continuent d'être des sources de puissance et méritent une attention soutenue.
Les marges littorales nord-ouest de la Russie (The maritime access of Russia to Baltic sea and Arctic ocean)
Authors: Guineberteau Thierry
Published: May 2015

Résumé. - La Russie dispose d'une ouverture maritime au nord-ouest de son territoire, sur la mer Baltique et l'océan Arctique. Ces fronts pionniers de l'époque tsariste puis soviétique présentent toujours un intérêt économique et stratégique indéniable. Ces régions sont aujourd'hui confrontées aux perturbations issues de la nouvelle donne territoriale et des nouvelles orientations économiques. Cette façade maritime, loin de présenter une image homogène, s'organise autour de trois foyers distincts : l'agglomération de Saint-Pétersbourg qui cherche à affirmer sa vocation de pôle régional dominant ; le duo côtier Mourmansk/Arkhangelsk excentré vers les plus hautes latitudes ; l'isolât de Kaliningrad entre Pologne et Lituanie. Issus de politiques volontaristes en matière de peuplement et de mise en valeur, ces foyers cherchent aujourd'hui leurs propres voies de développement en misant principalement sur les potentialités liées à cette position littorale.
L'encaissement du réseau hydrographique dans le bassin de la Loire supérieure (Rivers entrenchment in the upper Loire valley)
Authors: Defive Emmanuelle
Published: May 2015

Résumé. - L'étude du bassin supérieur de la Loire met en évidence le rôle primordial du compartimentage tectonique comme préalable nécessaire à l'encaissement, mais affirme celui du climat dans l'efficacité des dynamiques d'incision ainsi que dans le style de l'érosion responsable du creusement des vallées et, donc, de la forme de ces dernières. Quant au volcanisme, son rôle apparaît profondément perturbateur dès lors que les épanchements laviques aboutissent à un ennoiement généralisé et durable de la topographie. Outre ces facteurs, le rôle de la lithologie ou celui des héritages ne doit pas non plus être négligé. Tous contribuent au caractère compartimenté, dans le temps comme dans l'espace, du travail de l'érosion linéaire.
Peptide–polymer ligands for a tandem WW-domain, an adaptive multivalent protein–protein interaction: lessons on the thermodynamic fitness of flexible ligands
Authors: Koschek Katharina , Durmaz Vedat , Krylova Oxana , Wieczorek Marek , Gupta Shilpi , Richter Martin , Bujotzek Alexander , Fischer Christina , Haag Rainer , Freund Christian , Weber Marcus , Rademann Jörg
Published: May 2015

Three polymers, poly(N-(2-hydroxypropyl)methacrylamide) (pHPMA), hyperbranched polyglycerol (hPG), and dextran were investigated as carriers for multivalent ligands targeting the adaptive tandem WW-domain of formin-binding protein (FBP21). Polymer carriers were conjugated with 3–9 copies of the proline-rich decapeptide GPPPRGPPPR-NH2 (P1). Binding of the obtained peptide–polymer conjugates to the tandem WW-domain was investigated employing isothermal titration calorimetry (ITC) to determine the binding affinity, the enthalpic and entropic contributions to free binding energy, and the stoichiometry of binding for all peptide–polymer conjugates. Binding affinities of all multivalent ligands were in the µM range, strongly amplified compared to the monovalent ligand P1 with a KD > 1 mM. In addition, concise differences were observed, pHPMA and hPG carriers showed moderate affinity and bound 2.3–2.8 peptides per protein binding site resulting in the formation of aggregates. Dextran-based conjugates displayed affinities down to 1.2 µM, forming complexes with low stoichiometry, and no precipitation. Experimental results were compared with parameters obtained from molecular dynamics simulations in order to understand the observed differences between the three carrier materials. In summary, the more rigid and condensed peptide–polymer conjugates based on the dextran scaffold seem to be superior to induce multivalent binding and to increase affinity, while the more flexible and dendritic polymers, pHPMA and hPG are suitable to induce crosslinking upon binding.
Determination of PFOR gene expression in strains of G. intestinalis with different inhibitory concentrations of metronidazole
Authors: Begaydarova Rozalia , Yukhnevich Yekaterina , Babenko Dmitry , Kaliyeva Sholpan , Azizov Iliya , Muldaeva Gulmira , Omarkulov Baurzhan
Published: May 2015

Introduction: Giardia intestinalis is the most important and common diarrhea-causing parasitic protozoa worldwide with growing clinical relevance in public health. There are many documented cases of G. intestinalis resistance to metronidazole (MZ). Pyruvate: ferredoxin oxidoreductase (PFOR), the membrane-localized enzyme, plays a key role in the development of resistance to drugs. The aim of the present study was to evaluate the difference in the levels of PFOR gene expression between MZ-resistant and MZ-susceptible strains of G. intestinatlis. Methodology: From 159 samples with G. intestinalis cysts, 48 strains were successfully cultivated. Using specific pair primers, PFOR gene expressions were estimated in different groups of Giardia. The polymerase chain reaction (PCR) data were analyzed with Bayesian analysis of qRT-PCR data using MCMC.qpcr package, with relative expression software tool (REST) and quantitative PCR CopyCount web source. Results: In the group of Giardia with minimum inhibitory concentration (MIC) of 6.3 µM, the level of PFOR gene expression was downregulated and compared with controls, differed by 1.5 to 2.8 times. At the same time, there was no significant difference in PFOR gene expression between the control (susceptible) group and the group with MIC of 3.2 µM. Conclusions: Though there is association between PFOR gene expression and metronidazole resistance of Giardia intestinalis, the level of PFOR gene expression cannot be a strong genetic marker to predict level of resistance to metronidazole based on MICs.
Performance Enhancement of Differential Evolution by Incorporating Lévy Flight and Chaotic Sequence for the Cases of Satellite Images
Authors: Dhal Krishna Gopal , Quraishi Md. Iqbal , Das Sanjoy
Published: May 2015

Differential Evolution (DE) is a simple but powerful evolutionary algorithm. Crossover Rate (CR) and Mutation Factor (F) are the most important control parameters in DE. Mutation factor controls the diversification. In traditional DE algorithm CR and F are kept constant. In this paper, the values of CR and F are modified to enhance the capability of traditional DE algorithm. In the first modified algorithm chaotic sequence is used to perform this modification. In the next modified algorithm Lévy Flight with chaotic step size is used for such enhancement. In the second modified DE, population diversity has been used to build population in every generation. As a result the algorithm does not converge prematurely. Both modified algorithms have been applied to optimize parameters of the parameterized contrast stretching function. The algorithms are tested for satellite image contrast enhancement and the results are compared, which show that DE via chaotic Lévy and population diversity information outperforms the traditional and chaotic DE in the image enhancement domain.
Replacing Project Managers in Information Technology Projects
Authors: Liikamaa Kirsi , Vartiainen Tero , Pirhonen Maritta , Aramo-Immonen Heli
Published: May 2015

According to anecdotal evidence, project managers working on information technology (IT) projects are occasionally replaced, although the literature on information systems (IS) and project management (PM) makes little mention of it. With a view to narrowing this knowledge gap the authors examined the reasons behind the practice. The authors took an interpretive approach to the data gathering and analysis, and collected descriptions about replacing project managers (RPM) from interviews and questionnaires (n=43). The concept of contradiction served as a lens through which to identify the underlying reasons. Contradiction refers to statements asserting or expressing the opposite of another statement. The authors identified four contradictions explaining why RPM occurs in IT projects. These contradictions show that RPM appears to be a simplistic solution when there are more fundamental issues to consider. The implications extend to education, practice, and research in the context of IT project management.
Understanding the Turnover Intentions of Information Technology Personnel
Authors: Uzoka Faith-Michael E. , Shemi Alice P. , Mgaya K.V. , Obot Okure
Published: May 2015

Most of the studies on IT personnel turnover intentions were carried out in the developed countries. Only a few researchers have focused on developing countries. The authors' study makes a comparative study of IT personnel turnover intentions in two sub-Saharan African countries (Botswana and Nigeria) using the Igbaria and Greenhaus turnover model. The intent was to find out if the same model elements affect turnover intentions in the two countries. The results show that demographic variables (age and length of service), the role stressors (role ambiguity and role conflict), the career related variables (growth opportunity, supervisor support and external career opportunities), job satisfaction and career satisfaction have direct effect on turnover intentions in these two developing countries, while other affectors in the research model do not hold equally for the two countries, except for growth opportunity.
Implementation of Electronic Health Record (EHR) System in the Healthcare Industry
Authors: Schumaker Robert P , Reganti Kavya P.
Published: May 2015

The purpose of this research is to demonstrate the efficiency of the Electronic Health Record (EHR) software that is adopted in the healthcare industry to provide better patient care. The authors examine the impact of EHRs on the efficient delivery of healthcare services. More specifically, they detail the origin of EHR, its significance in modern healthcare delivery along with the selection and implementation criteria for EHR software. They present a survey on the extent of adoption of EHR by clinicians. They also highlight the challenges and barriers faced by organizations in adopting EHR software such as cost, workflow impact and data security. Finally, the authors contemplate the future of EHR, its role in the implementation of health information exchange and its implementation in the cloud. They conclude that the implementation of EHR in the cloud is an important step towards better health management across the population with the end-goal of better health outcomes.
Impact of Socialized Uncertainty on Group Decision Making
Authors: Strang Kenneth David , Vajjhala Narasimha Rao
Published: May 2015

Many stakeholders in society are concerned about the effectiveness of decision making behavior for our future generation of leaders. Risk taking behavior has been studied in the context of cultural factors (including gender) or decision making but rarely have both of these dimensions been examined simultaneously especially with emerging business leaders. Decision making behavior has not been studied at the group level of analysis in the context of socialized culture using samples of young emerging executives. Therefore, the authors conducted a controlled experiment with senior university students to test the impact of risk taking culture and gender on group decision making behavior in a complex project. In their experiment gender did not impact decision making behavior but the socialized uncertainty was a statistically significant casual factor. The authors conducted a controlled experiment with senior university students to test the impact of risk taking culture and gender on group decision making behavior in a complex project. Although their results agreed with the literature, one finding was completely opposite from their hypothesis. In the authors' experiment, the participant's gender did not impact decision making behavior but the socialized uncertainty factor was statistically significant in the logistic regression models.
Identification of Complex Shear Modulus of MR Layer Placed in Three-Layer Beam – Part 2: Algorithm
Authors: Romaszko Mateusz , Snamina Jacek , Pakuła Sebastian
Published: May 2015

The paper presents the procedure of identification of a complex shear modulus which describes properties of MR fluid in the pre-yield regime as a function of magnetic field. Data necessary for identification were collected basing on measurements of free vibrations of a three-layered cantilever beam at a special laboratory stand. Magnetic field exerting on MR fluid placed in the beam was generated by electromagnet. In the next step, complex modes of beam vibrations for various places of applying the magnetic field and its strength were calculated.
Adhesion of Cr/CrN Multilayers to Steel Substrates
Authors: Kot Marcin , Chronowska-Przywara Kinga , Major Łukasz , Lackner Juergen
Published: May 2015

Cr/CrN multilayers with a bilayer period λ = 62 ÷ 1000nm, were investigated. They were deposited by PLD technique on austenitic and ferritic stainless steel substrates. Coating hardness and adhesion to substrates were measured by nanoindentation and scratch testing. Multilayer properties were compared with single Cr and CrN coatings. The 2xCr/CrN and 4xCr/CrN multilayers exhibited hardness slightly lower than the hardness of a single CrN coating, while the critical load of the 4xCr/CrN multilayer, measured in the scratch test, was two times higher than for CrN. Furthermore, the character of coating failure also indicates the higher fracture toughness of multilayers than ceramic ones. The highest scratch resistance of the hardest multilayer with a bilayer period λ = 250nm is extremely interesting. The measured values of the critical loads LC1and LC2of all coatings were higher for harder ferritic than austenitic substrates. However, analysis of scratch track geometry indicated that coating failure occurred under the same deformation of the coating-substrate system, while the higher values of critical load for coatings on ferrite derived from the higher hardness of the substrate.
Analysis Based Optimization of Human Powered Vehicle Body
Authors: Dușe Dan Maniu , Ari Alexandru Radu
Published: May 2015

The human powered vehicle market is not only a larger market per unit than the automotive market, but it is one in growth. The main product of this market is the classical bicycle, which is familiar around the globe, but mainly in the urban environment. The bicycle, which in this paper will be considered a human powered vehicle, is slowly gaining ground in the field of urban transportation solutions. This paper analyzes the possibility of optimizing the body of a human powered vehicle recumbent tricycle through continuous fluid dynamics. The vehicle is already designed and built, and is fully functional. The body of the vehicle comes as a necessity to give the operator protection from the elements, but the main reason is, to give the vehicle less air resistance. This would be a great benefit to the operator and the perceived comfort. Usually the aerodynamics analysis comprise of a wind tunnel test that confirms the theoretical results. This paper shows the evolution of the body of a human powered vehicle as it is optimized after identifying the turbulent areas in its shapes. After optimization, a body is obtained which will be proposed for implementing over the built vehicle.
Modeling, Simulation and Experimental Determination of the Spine Muscle’s Activities of the Driver
Authors: Kulcsar Raul Miklos , Borozan Ion , Argesanu Veronica , Maniu Inocentiu , Jula Mihaela , Streian Felicia , Puta Tiberiu , Nagel Adrian
Published: May 2015

—Theaimofthisstudyistodeterminethespinemuscleactivitiesofthedriver.TheAnyBodysoftwarewasusedtosimulatethehumanbodymovementsduringthedriveandtodeterminethespinemuscleactivities.Tovalidatethesimulationresultatemographicalexperimentwasmadetoregisterthebackmuscleactivities.Thesimulationandthetermographicalexperimentprovedtobeusefultoolstodeterminespinemusculoskeletalaffectionsamongdrivers,andalsocanbeusedinthehuman-basedergonomicdesignofthevehicle’sinterior.