Heat flux calorimetry in intermetallic compound–H2(g) systems: heat measurements and modeling in the low pressures range

A heat conduction calorimeter has been used to determine enthalpies of solid–gas reactions in systems, such as intermetallic compounds–H₂(g). It is shown that the significance of the heat measurements must be carefully analyzed by controlling several parameters, which may influence the heat transfer conditions during the absorption and desorption reactions.

For this type of reaction, the measured heat flow is strongly dependent on the heat transfers through the gas phase in the low pressure range (Knudsen regime). It is demonstrated, experimentally and confirmed with simple models, that heat measurements can provide erroneous enthalpies due to our inability to account for the unavoidable modifications of the heat losses in the transition region. Experiments were carried out on the ZrNi–H₂ system.     

SBS/Pani · DBSA mixture plasticized with DOP and NCLS - Effect of the plasticizers on the probability density of volume resistivity measurements

Plasticized mixtures of styrene-butadiene-styrene block copolymer (SBS) and Polyaniline (Pani) were prepared in a Haake internal mixer. Two different plasticizers were used: dioctyl phthalate (DOP) and cashew nut shell liquid (CNSL). Pani and plasticizers were characterized by FTIR and the resistive behavior of plasticized mixtures was investigated along the electrification time. It is shown that obtained experimental data are subject to deterministic dynamic fluctuations that cannot be described by single normal probability distribution functions (PDF) along the time. The PDF analysis shows that obtained PDFs must be described as sums of at least three distinct Gaussian distributions with different areas. It is also shown that the Gaussian component with larger area may provide better representation of the measured volume resistivity values.     

Synthesis,analytical and spectral characterization for new VO (II)-triazole complexes; conformational study beside MOE docking simulation features

New triazole-derivatives were synthesized and characterized (spectral, analytical and conformational). After that, the new derivatives were coordinated with VO (II) atom to prepare new series of complexes. Distorted octahedral and square-pyramidal geometries, were the geometries suggested based on UV- Vis and ESR spectra. A neutral poly-dentate mode of bonding was proposed by 1:1 (M:L), for all complexes. TGA study supports the molecular formula of VO (II) complexes as well as, mass spectral-analysis that executed for examples. The isotropic, anisotropic, molecular orbital and Hamiltonian parameters were estimated upon ESR spectra, for selected complexes. XRD patterns were executed for three complexes, two among appeared with particulate-sizes in nanometer-range. Conformational study was executed for all synthesizes applying RTD-B3LYP-FC method. Essential physical parameters were estimated and discussed. MOE-docking that considered a bright part, was performed over all compounds towards 3s7s and 5jm5, as functional tumor proteins. The docking interaction parameters, introduced strongly some synthesizes to be anti-tumor agents.     

Definite integral registers using infinitesimals

I propose a theoretical model of representation registers for definite integral notation. The two registers, adding up pieces (AUP) and multiplicatively-based summation (MBS), are developed from modes of interpreting integral notation identified by S. Jones (2015). In this model, the AUP register affords modeling with definite integral notation, while the MBS register affords sense-making with and evaluation of integrals. These registers are illustrated in the context of a Calculus I class that used an informal infinitesimals approach; in this class differentials such as dx directly represented infinitesimal quantities instead of serving as a reminder of a quantity that existed before a limit was taken. Theoretical implications of extending Duval’s register theory (2006) in this way are also explored.     

Growth Modeling of Fiber Gratings: A Numerical Investigation

We have developed a simple method to analyze the growth process of fiber gratings (FGs) in the core of photorefractive optical fibers. It is based on the exponential saturation model and it takes into account the type of photosensitive fiber used, the exposure times, and the incident optical power. The photorefractive fiber has been characterized by two parameters: the saturation photoinduced refractive index change and the saturation energy, which can be obtained experimentally. We carry out a numerical investigation for the growth process of a uniform FG. The experimentally observed phenomena of shifting the Bragg optical frequency with exposure times and the appearance of higher-order Bragg resonances are predicted and discussed.     

Computational methods for Conway's Game of Life cellular automaton

The cellular automaton model of computation has drawn the interest of researchers from different disciplines including computer science, biology, mathematics, economy, biochemistry and philosophy. Although a cellular automaton is based on a set of simple rules, over time complex patterns may evolve. We present computational methods for implementing and optimizing a well known two-state cellular automaton, Conway's Game of Life, on a 16-core Intel Xeon. The evaluation is based on three multicore algorithms. The first algorithm is coherent and utilizes shared memory and barrier synchronization. The remaining two algorithms are distributed and utilize private memories and explicit core-to-core message passing. We provide a link to our open source simulation software.     

一种负高斯曲率的双三次Bézier曲面

负高斯曲率的曲面在建筑业、造船业及航空工业中都有广泛的应用。该文提出一种负高斯曲率双三次Ｂｅｚｉｅｒ曲面的构造方法，简单直观，几何意义明显。     

Recent progress in nanocrystalline Sm–Co based magnets

Sm–Co alloys are the most promising candidates for high temperature applications in advanced power systems owing to their high Curie temperature and high thermal stability of the magnetic performance. The recently developed nanocrystalline Sm–Co based magnets exhibit great potentials for magnetic performance enhancement and are expected to enlarge applications to services under extreme conditions. However, there have been few comprehensive reviews on the development of the nanocrystalline Sm–Co magnets so far. The efforts in this article are paid to review the recent progress in both experimental and modeling studies on the nanocrystalline Sm–Co magnets. Particularly, the latest advances in nanostructuring technologies, doping modulation, data-driven composition design and strategies for enhancement of magnetic properties have been introduced and evaluated. Finally, new challenges and opportunities regarding the future development of high-performance nanocrystalline Sm–Co based magnets are proposed.