Cataphoretic velocity of colloidal particles of lyophobic sols under constant current. A new setup to measure the boundary movement under constant current

Summary The migration velocities of the boundary of As₂S₃ and Fe(OH)₃ sols have been measured under constant current. A new set up for measuring the movement of the boundary under constant current has been devised. The changes in the boundary movement with time have been observed under constant current condition and it has been discussed and suggested that measurements of cataphoretic velocity of colloidal particles under constant current is theoretically more cogent than the measurements taken under constant voltage, because the changes in the resistance shown by the changes in the potential developed across the different elements in the U-tube at constant current give a more correct picture of what happens in the cataphoretic tube when cataphorisis takes place. A potentio-valve-voltmeter has been employed to measure the instantaneous changes of voltage across the mainU-tube without any time lag. This is a new device which has not been tried before.

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Zusammenfassung Die Wanderungsgeschwindigkeit an der Grenze von As₂S₃ and FeOH₃-Solen wurde gemessen, und zwar bei konstantem Strom. Eine neue Methode zur Messung der Wanderung bei konstantem Strom wird vorgeschlagen. Die Ver?nderungen der Bewegung der Grenze mit der Zeit werden diskutiert, und es wird vermutet, da? Messungen der kataphoretischen Geschwindigkeit von Kolloidpartikeln bei konstantem Strom theoretisch mehr Aussagen geben als Messungen bei konstanter Spannung, weil Widerstands?nderungen in den einzelnen Teilabschnitten des Kataphoreserohres bei konstantem Strom ein korrekteres Bild gibt. Ein Potentialr?hrenvoltmeter wurde für die Messung des Spannungsabfalls angewendet, so da? zeitliche ?nderungen verz?gerungsfrei aufgezeichnet werden konnten.

     

Search for ZH → l+ l- bb production in 4.2 fb(-1) of pp collisions at sqrt[s] =1 .96 TeV

We present a search for the standard model Higgs boson produced in association with a Z boson in 4.2 fb(-1) of pp collisions, collected with the D0 detector at the Fermilab Tevatron at sqrt[s] =1 .96 TeV. Selected events contain one reconstructed Z → e+ e- or Z → μ+ μ- candidate and at least two jets, including at least one b-tagged jet. In the absence of an excess over the background expected from other standard model processes, limits on the ZH cross section multiplied by the branching ratios are set. The limit at M(H) = 115 GeV is a factor of 5.9 larger than the standard model prediction.     

Problems on matchings and independent sets of a graph

Let $G$ be a finite simple graph. For $X?V\left(G\right)$, the difference of $X$, $d\left(X\right)?\left|X\right|?\left|N\left(X\right)\right|$ where $N\left(X\right)$ is the neighborhood of $X$ and $max\{d\left(X\right):X?V\left(G\right)\}$ is called the critical difference of $G$. $X$ is called a critical set if $d\left(X\right)$ equals the critical difference and $\ker \left(G\right)$ is the intersection of all critical sets. $\mathrm{diadem}\left(G\right)$ is the union of all critical independent sets. An independent set $S$ is an inclusion minimal set with$d\left(S\right)>0$ if no proper subset of $S$ has positive difference.A graph $G$ is called a König–Egerváry graph if the sum of its independence number $\alpha \left(G\right)$ and matching number $\mu \left(G\right)$ equals $\left|V\left(G\right)\right|$.In this paper, we prove a conjecture which states that for any graph the number of inclusion minimal independent set $S$ with $d\left(S\right)>0$ is at least the critical difference of the graph.We also give a new short proof of the inequality $\left|\ker \left(G\right)\right|+\left|\mathrm{diadem}\left(G\right)\right|\le 2\alpha \left(G\right)$.A characterization of unicyclic non-König–Egerváry graphs is also presented and a conjecture which states that for such a graph $G$, the critical difference equals $\alpha \left(G\right)?\mu \left(G\right)$, is proved.We also make an observation about $\ker \left(G\right)$ using Edmonds–Gallai Structure Theorem as a concluding remark.     

An improved approximation algorithm for requirement cut

This note presents improved approximation guarantees for the requirement cut problem: given an n-vertex edge-weighted graph G=(V,E), and g groups of vertices X₁,…,X_g⊆V with each group X_i having a requirement r_i between 0 and |X_i|, the goal is to find a minimum cost set of edges whose removal separates each group X_i into at least r_i disconnected components. We give a tight Θ(logg) approximation ratio for this problem when the underlying graph is a tree, and show how this implies an O(logk⋅logg) approximation ratio for general graphs, where .     

Structural,magnetic, and morphological study of cosputtered FeAl thin film grown in nonreactive environment

Fe-Al alloying is a matter of interest because of its technological importance and many applications. Different growth conditions may lead to different results, ie, formation of various phases. These phases may be magnetic or nonmagnetic in nature. Cosputtering of Fe and Al with magnetron-sputtering setup provides us with a good option of alloying and to study the various phase formations. As, yet now researchers studied the alloying through cosputtering process only in oxygen environment, so a study in nonreactive environment was inevitable and interesting. Therefore, the authors went for Fe-Al thin-film synthesis using the magnetron sputtering in argon environment. Hence, this paper discusses the Fe and Al alloy formation in argon environment and annealed the samples at different temperatures for different time durations so as to allow various phase formations. The samples were characterized with grazing incidence X-ray diffraction (GIXRD), grazing incidence X-ray reflectivity (GIXRR), magneto-optical Kerr effect (MOKE), and atomic force microscopy (AFM) techniques so as to study structural, morphological, and magnetic properties. The results confirm that cosputtering provides better chances of alloying and also supports formation of various stable phases in comparison with other available techniques.     

Metabolite assignment of ultrafiltered synovial fluid extracted from knee joints of reactive arthritis patients using high resolution NMR spectroscopy

Currently, there are no reliable biomarkers available that can aid early differential diagnosis of reactive arthritis (ReA) from other inflammatory joint diseases. Metabolic profiling of synovial fluid (SF)—obtained from joints affected in ReA—holds great promise in this regard and will further aid monitoring treatment and improving our understanding about disease mechanism. As a first step in this direction, we report here the metabolite specific assignment of ¹H and ¹³C resonances detected in the NMR spectra of SF samples extracted from human patients with established ReA. The metabolite characterization has been carried out on both normal and ultrafiltered (deproteinized) SF samples of eight ReA patients (n = 8) using high-resolution (800 MHz) ¹H and ¹H─¹³C NMR spectroscopy methods such as one-dimensional ¹H CPMG and two-dimensional J-resolved¹H NMR and homonuclear ¹H─¹H TOCSY and heteronuclear¹H─¹³C HSQC correlation spectra. Compared with normal SF samples, several distinctive ¹H NMR signals were identified and assigned to metabolites in the ¹H NMR spectra of ultrafiltered SF samples. Overall, we assigned 53 metabolites in normal filtered SF and 64 metabolites in filtered pooled SF sample compared with nonfiltered SF samples for which only 48 metabolites (including lipid/membrane metabolites as well) have been identified. The established NMR characterization of SF metabolites will serve to guide future metabolomics studies aiming to identify/evaluate the SF-based metabolic biomarkers of diagnostic/prognostic potential or seeking biochemical insights into disease mechanisms in a clinical perspective.