Dynamics of SAMs in Boundary Lubrication

Surfactant molecules have some properties responsible for a number ofremarkable phenomena, such as oriented adsorption of surfactants at surfaces and interfaces. The capability to self -assemble into well- defined structures is often seen as being more important than their surface activity. When a surfactant solution is in contact with a solid surface, the surfactant molecules adsorb onto the surface, ideally forming an adsorbed layer of a high order, termed as a self- assembled monolayer (SAM). Many surface properties are influenced bysuch a film, and therefore, SAMs offer the capability to form ordered organic surface coatings, suitable for various applications, such as wetting or corrosion protection. Due to the flexibility in choosing the molecular architecture, organic molecules have many interesting applications, such as biosensors, in Photoelectronics, in controlling water adsorption or boundary lubricant coating. This paper Focuses on cationic surfactants (quaternary ammonium surfactants) with some unique properties that are not present in other surfactants

Sharp oscillation criteria for fourth order sub-half-linear and super-half-linear differential equations

This paper is concerned with the oscillatory behavior of the fourth-order nonlinear differential equation $$\bigl(p(t)|x^{\prime\prime}|^{\alpha-1}\,x^{\prime\prime}\bigr)^{\prime\prime} +q(t)|x|^{\beta-1}x=0\,,\tag{E}$$ where $\alpha>0$, $\beta>0$ are constants and $p,q:[a,\infty)\to(0,\infty)$ are continuous functions satisfying conditions $$\int_a^{\infty}\left( \frac{t}{p(t)}\right)^{\frac{1}{\alpha}}\,dt<\infty, \int_a^{\infty}\frac{t}{\left(p(t)\right)^{\frac{1}{\alpha}}}\,dt<\infty .$$ We will establish necessary and sufficient condition for oscillation of all solutions of the sub-half-linear equation (E) (for $\beta\alpha$)

Creation operators and algebraic Bethe ansatz for the elliptic quantum group Eτ,η(so3)E_{\tau,\eta}(so_3)

We define the elliptic quantum group $E_{\tau,\eta}(so_3)$ and the transfer matrix corresponding to its simplest highest weight representation. We use Bethe anstaz method to construct the creation operators as polynomials of the Lax matrix elements expressed through a recurrence relation. We give common eigenvectors and eigenvalues of the family of commuting transfer matrices.Comment: 13 page

Supplementary data for the article: Dimitrijević, T.; Vulić, P.; Manojlović, D.; Nikolić, A. S.; Stanković, D. M. Amperometric Ascorbic Acid Sensor Based on Doped Ferrites Nanoparticles Modified Glassy Carbon Paste Electrode. Analytical Biochemistry 2016, 504, 20–26. https://doi.org/10.1016/j.ab.2016.03.020

Supplementary material for: [https://doi.org/10.1016/j.ab.2016.03.020]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1950

Gravitational waves and dragging effects

Linear and rotational dragging effects of gravitational waves on local inertial frames are studied in purely vacuum spacetimes. First the linear dragging caused by a simple cylindrical pulse is investigated. Surprisingly strong transversal effects of the pulse are exhibited. The angular momentum in cylindrically symmetric spacetimes is then defined and confronted with some results in literature. In the main part, the general procedure is developed for studying weak gravitational waves with translational but not axial symmetry which can carry angular momentum. After a suitable averaging the rotation of local inertial frames due to such rotating waves can be calculated explicitly and illustrated graphically. This is done in detail in the accompanying paper. Finally, the rotational dragging is given for strong cylindrical waves interacting with a rotating cosmic string with a small angular momentum.Comment: Scheduled to appear in Class. Quantum Grav. July 200

The isolation, analytical characterization by HPLC-UV and NMR spectroscopy, cytotoxic and antioxidant activities of baeomycesic acid from Thamnolia vermicularis var. subuliformis

The aim of this work was the analytical characterization of the β-orcinol depside, baeomycesic acid in lichens extracts. The extract of Thamnolia vermicularis var. subuliformis was analyzed by the two different methods, namely HPLC-UV and 1H NMR analysis. The results showed that baeomycesic acid was the most abundant depside in the lichens. These results could be of use for rapid identification of this metabolite in other lichen species. Besides baeomycesic acid, three depsides and one monocyclic phenolic compound were isolated from the lichen extract on the chromatographic column. The structure of baeomycesic acid was confirmed by HPLC-UV and spectroscopic methods. In addition, antioxidant and cytotoxic activities of baeomycesic acid were determined. The result of the testing showed that baeomycesic acid exhibited a moderate radical scavenging activity (IC50 = 602.10 ± 0.54 μg/mL) and good cytotoxic activity. This is the first report of detailed analytical characterization, isolation, as well as antioxidant and cytotoxic activities of baeomycesic acid from Thamnolia vermicularis. These results may be helpful in future industrial production of herbal medicines that include this important natural product

A new flood risk assessment framework for evaluating the effectiveness of policies to improve urban flood resilience

This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this record.To better understand the impacts of flooding such that authorities can plan for adapting measures to cope with future scenarios, we have developed a modified Drivers-Pressures-State-Impact-Response (DPSIR) framework to allow policy makers to evaluate strategies for improving flood resilience in cities. We showed that this framework proved an effective approach to assessing and improving urban flood resilience, albeit with some limitations. This framework has difficulties in capturing all the important relationships in cities, especially with regards to feedbacks. There is therefore a need to develop improved techniques for understanding components and their relationships. While this research showed that risk assessment is possible even at the mega-city scale, new techniques will support advances in this field. Finally, a chain of models engenders uncertainties. However, the resilience approach promoted in this research, is an effective manner to work with uncertainty by providing the capacity to cope and respond to multiple scenariosResearch on the CORFU (Collaborative research on flood resilience in urban areas) project was funded by the European Commission through Framework Programme 7, Grant Number 244047. The work in this paper was partially funded by the PEARL (Preparing for Extreme And Rare events in coastaL regions) project, supported by the European Union's Seventh Framework Programme under Grant Agreement No 603663

Robust, Universal Tree Balance Indices

Balance indices that quantify the symmetry of branching events and the compactness of trees are widely used to compare evolutionary processes or tree-generating algorithms. Yet existing indices are not defined for all rooted trees, are unreliable for comparing trees with different numbers of leaves, and are sensitive to the presence or absence of rare types. The contributions of this article are twofold. First, we define a new class of robust, universal tree balance indices. These indices take a form similar to Colless’ index but can account for population sizes, are defined for trees with any degree distribution, and enable meaningful comparison of trees with different numbers of leaves. Second, we show that for bifurcating and all other full m-ary cladograms (in which every internal node has the same out-degree), one such Colless-like index is equivalent to the normalised reciprocal of Sackin’s index. Hence we both unify and generalise the two most popular existing tree balance indices. Our indices are intrinsically normalised and can be computed in linear time. We conclude that these more widely applicable indices have potential to supersede those in current use

Elemental Profile of Hashimoto’s Thyroiditis: Thyroid Tissue, Blood, and Urine Analysis

Hashimoto’s thyroiditis (HT) is the most prevalent autoimmune disorder of the thyroid gland [1]. As a result of the continuous deterioration of the gland caused by HT, more than 90% of patients develop thyroid insufficiency and hypothyroidism [2]. It has been noted that genetic and/or environmental factors play an important role in the etiology of HT [3]. The most prevalent environmental and hazardous risk factors that were linked to the pathogenesis of HT include Se deficit, pollutants, and irradiation [4]. The focus of this research was to determine which trace elements could have a role in the pathophysiology of HT. In this regard, the essential trace elements for thyroid homeostasis (Mn, Cu, Zn, Se) and the main hazardous toxic trace elements (Ni, As, Pb, Cd, U) were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) in the thyroid tissue, blood, and urine samples of patients with diagnosed HT. Control samples of blood and urine were collected from healthy donors. Moreover, the effects of relevant parameters on element profiles were examined and addressed in terms of environmental concerns. This investigation discovered a variation in the elemental profile of HT and control samples. Thyroid tissue and HT blood samples had significantly increased As and Pb levels. The obtained negative correlations between As and Pb and Se potentially indicates the antagonistic influence of As and Pb on the extrusion of essential Se from the HT tissue. The absence of Se in HT could be further explained by the obtained lower levels of Se in blood and higher Se in urine samples. Importantly, the findings could provide the understanding of the as-yet unresolved molecular basis of HT, and also highlight the role of these elements on thyroid homeostasis

The Geroch group in the Ashtekar formulation

We study the Geroch group in the framework of the Ashtekar formulation. In the case of the one-Killing-vector reduction, it turns out that the third column of the Ashtekar connection is essentially the gradient of the Ernst potential, which implies that the both quantities are based on the ``same'' complexification. In the two-Killing-vector reduction, we demonstrate Ehlers' and Matzner-Misner's SL(2,R) symmetries, respectively, by constructing two sets of canonical variables that realize either of the symmetries canonically, in terms of the Ashtekar variables. The conserved charges associated with these symmetries are explicitly obtained. We show that the gl(2,R) loop algebra constructed previously in the loop representation is not the Lie algebra of the Geroch group itself. We also point out that the recent argument on the equivalence to a chiral model is based on a gauge-choice which cannot be achieved generically.Comment: 40 pages, revte