A systematic method for the hybrid dynamic modeling of open kinematic chains confined in a closed environment

This work presents a systematic method for the dynamic modeling of multi-rigid links confined within a closed environment. The behavior of the system can be completely characterized by two different mathematical models: a set of highly coupled differential equations for modeling the confined multi-link system when it has no impact with surrounding walls; and a set of algebraic equations for expressing the collision of this open kinematic chain system with the confining surfaces. In order to avoid the Lagrangian formulation (which uses an excessive number of total and partial derivatives in deriving the governing equations of multi-rigid links), the motion equations of such a complex system are obtained according to the recursive Gibbs–Appell formulation. The main feature of this paper is the recursive approach, which is used to automatically derive the governing equations of motion. Moreover, in deriving the motion equations, the manipulators are not limited to planar motions only. In fact, for systematic modeling of the motion of a multi-rigid-link system in 3D space, two imaginary links are added to the \(n\)-real links of a manipulator in order to model the spatial rotations of the system. Finally, a 2D and a 3D case studies are simulated to demonstrate the effectiveness of the proposed approach.     

Modulation Based Combination of High Level Features Generated from SCCF & Contourlet Transforms for CBIR Applications

The need for suitable and cost-effective technologies rise with the growth of the internet of things (IoT) applications. These aim at handling voluminous data transmission in addition to minimum energy and latency cost constraints. LoRa networks are recommended for applications in confined spaces, long ranges, and less battery consumption requirements. However, the end devices in these networks communicate to all gateways in their ranges, thereby expediting energy unproductively in redundant transmissions. In our article, we explore the possibilities of whether LoRa networks could employ the advantages of clustering and propose two algorithms, path-based and data-centric, for such networks. We suggest that LoRaWAN technology with clustering can be apt for long-range, low power consumption IoT applications in the future. We study the impact of network density, node range, and cluster range on the energy consumption in data transmissions. The algorithms are compared with the inherent star-based communication of LoRa networks based on energy consumed, and our results show that, for dense deployments, clustering becomes advantageous.

     

电子战装备技术发展现状与展望

信息技术的快速发展为电子战装备技术的进步提供了巨大动力,尤其是随着人工智能等技术的广泛应用,颠覆性的电子战装备技术不断涌现,将加速现代战争模式的演变。以具有代表性的军事强国为例,综述了电子战装备技术的发展战略、主要技术特点和典型前沿技术,在此基础上,对电子战装备技术的发展趋势进行了展望。     

Biochemical studies on some non conventional sources of protein Part 3. The molasse

Among the high carbohydrate content the cane molasses contains considerable amount of nitrogen compounds including proteins and amino acids. Protein hydrolyzates showed the presence of 16 amino acids with aspartic and glutamic acids and alanine as the major acids in both states bound and free, and there were two unidentified N-containing free acids. Fe, Zn, Mn and Cu were predominant microminerals, K and P were found to be present and in smaller quantities Na.     

The impact of supplementing goats' milk with quinoa extract on some properties of yoghurt

This study investigated the impact of supplementing goats' milk with quinoa extracts, in the range of 5, 10 and 15 g/100 g on the milk fermentation. The properties of yoghurt produced from this milk, which include viscosity, microstructure and sensory acceptability, were assessed. The supplementation of goats' milk with quinoa extracts, particularly permeate extract, reduced the fermentation time and enhanced the viability of lactic acid bacteria. Supplementation of yoghurt with increased levels of quinoa extracts increased the apparent viscosity and changed the yoghurt protein matrix. Panellists highly accepted the yoghurt that contained quinoa permeate extract.     

Plasticity modeling of FRP-confined circular reinforced concrete columns subjected to eccentric axial loading

This paper presents a numerical study on FRP-wrap strengthened reinforced concrete columns subjected to eccentric axial loads using ABAQUS®. For modeling of concrete dilation under non-uniform confinement pressure, a smooth cap plasticity model was combined with concrete damaged plasticity model. This model includes different concrete compaction–dilation behaviors which is pressure-dependent. Proposed model has been calibrated and verified for concrete in number of unconfined and full-wrapped columns under combination of axial force and bending moment. Presented numerical predictions are shown to be in close agreement with existing experimental results. The effect of laminate stacking sequences and column slenderness on strength and ductility of members was examined thoroughly. The results of this study recommend taking fiber angles between zero (circumferential) and 30° can improve ultimate strength and ductility of confined short concrete columns. However, for slender concrete columns the optimum fiber orientation can be set between 15° and 30°.     

Antibacterial activity of cationically modified cotton fabric with carboxymethyl chitosan

A water‐soluble carboxymethyl chitosan was prepared with a view to develop a multifunctional finish on cotton. Carboxymethyl chitosan (CMCTS) was synthesized by chemical reaction of chitosan with monochloroacetic acid under alkaline condition. The water soluble CMCTS was applied to cationized cotton with different concentrations. The treated fabrics were characterized through monitoring the textile physical properties and for the antibacterial activity against Escherichia coli DSMZ 498 and Micrococcus luteus ATCC 9341. The results obtained show that the physical properties of the treated fabrics are improved by increasing the CMCTS concentration, as well as the antibacterial activity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Structure–property relationship of hetero‐aromatic‐electron‐donor antennas of polypyridyl Ru (II) complexes for high efficiency dye‐sensitized solar cells

Three novel heteroleptic amphiphilic polypyridyl Ru‐complexes, coded MH08–10 , with hetero‐aromatic electron‐donor ancillary ligands containing N‐benzylcarbazole ( MH08 ), dibenzofurane ( MH09 ) and benzothiophene moieties ( MH10 ) were synthesized to study the influence of different heterocyclic electron donors on the interrelationship of photophysical and electrochemical properties, and device performances for dye‐sensitized solar cells (DSSCs). MH08 showed a remarkably high molar extinction coefficient of 27,650 M⁻¹cm⁻¹. MH08–TBA was synthesized from MH08 by converted one COOH group into −COO⁻⁺N(C₄H₉)₄ to investigate the effect of deprotonating one carboxylic group on the Fermi level and electron injection. When compared under the same experimental device conditions using 0.3M t‐butylpyridine (TBP), the short‐circuit photocurrent density (J_SC) and total conversion efficiency (%η) of MH08–10 were MH08 > MH09 > MH10 . The differences in %η and J_SC of MH08–10 were ascribed to the conjugation length coupled with the electron donation and hole‐transport strength of the ancillary ligands, which were in the following order N‐benzylcarbazole>dibenzofurane>benzothiophene. Moreover, MH08–TBA showed J_SC of 19.56 mAcm⁻² and %η of 9.76% compared to 17.16 mAcm⁻² and 9.12% of the benchmark dye N719 . The superior performance of MH08–TBA was attributed to its better light harvesting and enhanced incident‐photon‐to‐current efficiency (IPCE) conversion. DFT/TD‐DFT calculations utilizing the energy functional B3LYP and the full‐electron basis set DGDZVP were performed to calculate HOMO and LUMO energies, vertical electronic excitations, lowest singlet‐singlet electronic transitions (E_0‐0), and excited state oxidation potentials. Excellent agreement was found between the experimental results and calculated data. Copyright © 2013 John Wiley & Sons, Ltd.