On a mild generalization of the Schönemann - Eisenstein - Dumas irreducibility criterion

We state a mild generalization of the classical Schönemann and Eisenstein- Dumas irreducibility criterion in ?[x] and provide an elementary proof. In the end of the paper, we also provide a concrete example of a polynomial which is irreducible by the main result of the paper but whose irreducibility does not follow from existing criteria.     

Sheath formation in the presence of non-extensive electron distribution

The main aim of this article is to recognize the sheath formation in the presence of non-extensive electron distribution. The role of ion–neutral collision parameter K and the non-extensive parameter “q” has been discussed. Existing literature suggests that the presence of non-extensive electrons potentially modifies the plasma sheath behaviour. However, numerical calculations over the full plasma range, jointly addressing the sheath and presheath, are rare. Sheath formation, being a very fundamental phenomenon, deserves enough investigation in the region of non-extensive distribution of particles. This study attempts to bridge the gap in understanding the formation of the sheath in collisional plasma in the light of both Boltzmann and q-distributed non-extensive electrons.     

Iron-catalyzed cross-dehydrogenative CN coupling of thiohydantoins with various amines

A novel iron-catalyzed CN bond construction method for the hetero-cross-dehydrogenative coupling (CDC) of diverse thiohydantoins with amines utilizing TBHP as the oxidant was developed. This sp³ CH amination at the carbons alpha to carbonyl groups of thiohydantoin tolerates the presence of a wide range of functional groups and provides the corresponding N-substituted amines in moderate to good yields. Various substrate scopes and optimum reaction conditions leads inside in organic synthesis.     

Phenolate- and acetate (both mu(2)-1,1 and mu(2)-1,3 mode)-bridged face-shared trioctahedral linear Ni(II)(3), Ni(II)(2)M(II) (M = Mn, Co) complexes: ferro- and antiferromagnetic coupling

The complexes [(L)(2)Ni(II)(2)M(II)(mu(2)-1,3-OAc)(2)(mu(2)-1,1-OAc)(2)(S)(2)] x xMeOH [HL = N-methyl-N-(2-hydroxybenzyl)-2-aminoethyl-2-pyridine; M = Ni, S = MeOH, x = 6 (1); M = Mn, S = H(2)O, x = 0 (2); M = Co, S = MeOH, x = 6 (3)] have been synthesized. Crystal structures reveal that three octahedral MII ions form a linear array with two terminal moieties {(L)Ni(II)(mu(2)-1,3-OAc)(mu(2)-1,1-OAc)(MeOH/H(2)O)}(-) in a facial donor set and a central MII ion which is connected to the terminal ions via bridging phenolate and two types of bridging acetates. Magnetic measurements reveal that the Ni(II)(3) and Ni(II)(2)Co(II) centers are ferromagnetically and Ni(II)(2)Mn(II) center is antiferromagnetically coupled. An attempt has been made to rationalize the observed magneto-structural behavior.     

Self-assembled ultra-thin coatings of octadecyltrichlorosilane (OTS) formed at the surface of iron oxide nanoparticles

In a series of experiments, we coated iron oxide nanoparticles, which were originally stabilized with lauric acid, with a polymer layer of Octadecyltrichlorosilane (OTS). Characterization of the different coated nanoparticles was accomplished by Static and Dynamic Light Scattering, acoustic spectroscopy, and Atomic Force Microscopy. In various experiments, we systematically investigated the effect of different parameters such as the OTS concentration and iron oxide content on the particle size of the coated nanoparticles. It was recognized that the size of the coated nanoparticles mainly depend on the concentration of OTS (C _OTS) measured with respect to the concentration of the iron oxide particles (C _mag.). Below a well-defined threshold value of C _OTS /C _mag, we did not observe any adsorption of OTS on the surface of iron oxide nanoparticles. The particle size of OTS-coated iron oxide nanoparticles increased rapidly at concentration ratios above the threshold concentration and reached a typical plateau value for long periods of time.     

Eggshell Nanosheets: Synthesis,Properties, and Their Forensic Applications in Latent Friction Ridges Development

Since waste materials are used to identify, individualize, and evaluate evidence like fingerprints, palmprints, footprints, etc. that are found at a crime scene, they have a substantial impact on the field of forensic science. Many waste powders have recently been employed in fingerprint recognition. Nanosheets made up of eggshells have been put forward as an application in friction ridge development. Eggshell is a biochemical substance made up of chemical compounds like calcium carbonate, which is considered as a waste product. For the formation of an eggshell nanosheet (ESN), shells are dried and crushed into a fine powder and to get this powder in the form of a nanosheet, the Ball milling technique is used. The synthesis of pure ESN is confirmed by Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) techniques. The size of nanosheets ranged from 30 to 90 nm as shown in SEM images. Developed powder is then used for the application of fingerprint development and it provides excellent results on all porous, non-porous, and semi-porous surfaces. Thus, this newly synthesized ESN powder can be used as a significant powder method in latent fingerprint technology.     

Elementary Properties of the Finite Ranks

This note investigates the class of finite initial segments of the cumulative hierarchy of pure sets. We show that this class is first-order definable over the class of finite directed graphs and that this class admits a first-order definable global linear order. We apply this last result to show that FO(<, BIT) = FO(BIT).     

Consolidating Maintenance Spares

The inventory of spare parts that a firm holds depends on the number of working parts and age of the equipment to be serviced, the expected failure rate associated with each working part, and the acceptable level of service. We model the problem of consolidation of spare parts to reduce overall inventory as an integer program with a nonlinear objective function. A linear reformulation of this model is obtained that helps solve some practical instances. A more compact implicit formulation is developed and solved using a specialized branch-and-price technique. We also demonstrate how this specialized branch-and-price technique is modified to devise a very effective heuristic procedure with a prespecifiable guarantee of quality of solution produced. This provides a practical and efficient methodology for maintenance spare consolidation.     

Mixed metal MgO–ZrO2 nanoparticle‐catalyzed O‐tert‐Boc protection of alcohols and phenols under solvent‐free conditions

An environmentally benign method for O‐tert‐Boc protection of alcohols and phenols catalyzed by MgO–ZrO₂ nanoparticles under solvent‐free conditions is described. A variety of phenols, alcohols (aliphatic and aromatic) were converted to corresponding O‐tert‐Boc products in good to excellent yield (50–95%). The present protocol is expedient, simple, and efficient under solvent‐free conditions. The MgO–ZrO₂ Nps are easily prepared from inexpensive precursors, and are reusable, recyclable and chemoselective. Copyright © 2012 John Wiley & Sons, Ltd.     

Direct construction of novel dispiro heterocycles through 1,3-dipolar cycloaddition of azomethine ylides

The 1,3-dipolar cycloaddition of 2-oxo-(2H)-acenaphthylen-1-ylidene-malononitrile and 2-fluoren-9-ylidene-malononitrile as dipolarophiles have been investigated for the first time with the azomethine ylides generated in situ from N-substituted isatin and sarcosine to furnish novel dispiro heterocycles. The structure and relative stereochemistry of both types of cycloadducts were confirmed by single crystal X-ray diffraction, as well as with the help of ¹H, ¹³C, and HMBC spectroscopic methods.