Investigation of phase diagrams for cylindrical Ising nanotube using cellular automata

Recent developments in the field of applied nanoscience and nanotechnology have heightened the need for categorizing various characteristics of nanostructures. In this regard, this paper establishes a novel method to investigate magnetic properties (phase diagram and spontaneous magnetization) of a cylindrical Ising nanotube. Using a two-layer Ising model and the core-shell concept, the interactions within nanotube has been modelled. In the model, both ferromagnetic and antiferromagnetic cases have been considered. Furthermore, the effect of nanotube's length on the critical temperature is investigated. The model has been simulated using cellular automata approach and phase diagrams were constructed for different values of inter- and intra-layer couplings. For the antiferromagnetic case, the possibility of existence of compensation point is observed.     

A Bayesian network structure for operational risk modelling in structured finance operations

This paper is concerned with the design of a Bayesian network structure that is suitable for operational risk modelling. The model's structure is designed specifically from the perspective of a business unit operational risk manager whose role is to measure, record, predict, communicate, analyse and control operational risk within their unit. The problem domain modelled is a functioning structured finance operations unit within a major Australian bank. The network model design incorporates a number of existing human factor frameworks to account for human error and operational risk events within the domain. The design also supports a modular structure, allowing for the inclusion of many operational loss event types, making it adaptable to different operational risk environments.     

N2O4 Chemisorbed onto n‐Propylsilica Kryptofix 21 and Kriptofix 22 as Two New Functional Polymers for the Fast Oxidation of Urazoles and 1,4‐Dihydropyridines

3‐Chloropropylsilica was reacted with Kriptofix 21 or 22 in the presence of triethylamine to form N‐propylsilica Kryptofix 21 and Kriptofix 22. Then N₂O₄ was added to each of these polymers to chemisorb onto cavity of aza‐crown ethers. These functionalized polymers were applied for the fast and simple oxidation of urazoles and 1,4‐dihydropyridines, respectively.     

A novel fuzzy C-means algorithm to generate diverse and desirable cluster solutions used by genetic-based clustering ensemble algorithms

One of the most significant discussions in the field of machine learning today is on the clustering ensemble. The clustering ensemble combines multiple partitions generated by different clustering algorithms into a single clustering solution. Genetic algorithms are known for their high ability to solve optimization problems, especially the problem of the clustering ensemble. To date, despite the major contributions to find consensus cluster partitions with application of genetic algorithms, there has been little discussion on population initialization through generative mechanisms in genetic-based clustering ensemble algorithms as well as the production of cluster partitions with favorable fitness values in first phase clustering ensembles. In this paper, a threshold fuzzy C-means algorithm, named TFCM, is proposed to solve the problem of diversity of clustering, one of the most common problems in clustering ensembles. Moreover, TFCM is able to increase the fitness of cluster partitions, such that it improves performance of genetic-based clustering ensemble algorithms. The fitness average of cluster partitions generated by TFCM are evaluated by three different objective functions and compared against other clustering algorithms. In this paper, a simple genetic-based clustering ensemble algorithm, named SGCE, is proposed, in which cluster partitions generated by the TFCM and other clustering algorithms are used as the initial population used by the SGCE. The performance of the SGCE is evaluated and compared based on the different initial populations used. The experimental results based on eleven real world datasets demonstrate that TFCM improves the fitness of cluster partitions and that the performance of the SGCE is enhanced using initial populations generated by the TFCM.     

Synthesis of different types of carbon nanohybrid and their effects in polymer composites

Research on Chemical Intermediates - Different types of carbon nanohybrid, including carbon nanotubes–graphene (CNT–G), carbon nanospheres–graphene (CNS–G), and carbon...     

Development of novel magnetic solid-phase extraction sorbent based on Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>/carbon nanosphere/polypyrrole composite and their application to the enrichment of polycyclic aromatic hydrocarbons from water samples prior to GC–FID analysis

We describe a magnetic nanocomposite that consists of Fe₃O₄/carbon nanosphere/polypyrrole (Fe₃O₄/CNS/PPy). The synthesized nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. The nanocomposite was successfully applied to extract of the polycyclic aromatic hydrocarbons (PAHs) from water samples. Compared to Fe₃O₄/PPy, the Fe₃O₄/CNS/PPy nanocomposite exhibits improved properties in terms of extraction. The amount of adsorbent, salt effect, extraction time, desorption time, type, and the volume of desorption solvent were optimized. Following the desorption of the extracted analytes, the PAHs (i.e., naphthalene, 2-methylnaphthalene, 2-bromonaphthalene, fluorene, and anthracene) were quantified by gas chromatography–flame ionization detector. The PAHs can be determined in 0.05–100.00 ng mL^?1 concentration range, with limits of detection (at an S/N ratio of 3) ranging from 0.01 to 0.05 ng mL^?1. The repeatability of the method was investigated with relative standard deviations of lower than 9.9% (n = 5). Also, the recoveries from spiked real water samples were in the range of 88.9–99.0%. The results indicate that the novel material can be successfully applied for the extraction and analysis of PAHs from water samples.     

A note on best proximity point theory using proximal contractions

In this paper, a reduction technique is used to show that some recent results on the existence of best proximity points for various classes of proximal contractions can be concluded from the corresponding results in fixed point theory.     

A photocatalytic green system for chemoselective reduction of nitroarenes

A highly efficient photocatalytic reduction of nitroarenes using TiO₂/polyethylene glycol 400-water (TiO₂/PEG–H₂O) is reported. This system at deoxygenated and illuminated (sunlight or violet LED) conditions efficiently reduced nitroarenes using oxalic acid or ammonium formate as a sacrificial electron donor. Reducible functional groups such as chloro, hydroxy, flouro, bromo and carbonyl were intact under the optimized reaction conditions. The 0.1 and 0.5–1 mmol amount of nitroarenes was used under sunlight and violet LED (400 nm) irradiation, respectively. Reusability of the nanotitania was successfully carried out four times. The analyses of the recovered catalyst after five runs including TEM, XRD, TGA and CHN were done and results showed that PEG is located on TiO₂; no change in morphology, crystallinity and particle sizes was observed.     

Fast removal and determination of doxycycline in water samples and honey by Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> magnetic nanoparticles

Adsorption characteristics and doxycycline (DC) removal efficiency of Fe₃O₄ magnetic nanoparticles as adsorbents have been determined by investigating the effects of pH, concentration of the DC, amount of adsorbents, contact time, ionic strength and temperature. The mechanism of adsorption was also studied. The adsorption of DC to the Fe₃O₄ magnetic nanoparticles could be described by Langmuir-type adsorption isotherms. Short contact time between the reagents, reusability of Fe₃O₄ for three times after recycling of the nanoparticles, good precision and accuracy, wide working pH range and high breakthrough volume are among the highlights of this procedure. The proposed extraction and determination procedure based on magnetic nanoparticles as adsorbent was successfully applied to the determination of DC spiked in honey and various water samples. The method presented here is fast, simple, cheap and robust, and it does not require the use of organic solvents. Also, the method needs only a magnet and can be performed in any laboratory without sophisticated equipment.     

Cache Oblivious Algorithms for the RMQ and the RMSQ Problems

In the Range Minimum/Maximum Query (RMQ) and Range Maximum-Sum Segment Query (RMSQ) problems, we are given an array which we can preprocess in order to answer subsequent queries. In the RMQ query, we are given a range on the array and we need to find the maximum/minimum element within that range. On the other hand, in RMSQ query, we need to return the segment within the given query range that gives the maximum sum. In this paper, we present cache oblivious optimal algorithms for both of the above problems. In particular, for both the problems, we have presented linear time data structures having optimal cache miss. The data structures can answer the corresponding queries in constant time with constant cache miss.