Prismatic Configuration Research Articles

The “Villas de Sesimbra” Aparthotel and The Importance of Training Low-Skilled Workers

This case study describes the complex process of qualifying accommodation employees at the “Villas de Sesimbra” aparthotel, in the context of an organizational change and the development of a prismatic structural configuration that favours leadership and management by teams, an organization who learns. This is, effectively, a case study of management and employee satisfaction based on the consolidation of the strategic “pillar”, par excellence, of People Management, constituted by “continuous and qualifying professional training, in practice” (Lopes, 2012), in relation to all 12-hotel staff (permanent and seasonal). By proceeding in this way, the hierarchical pyramid is considerably reduced, and may even nullify the tradition of maintaining indefinitely the organization of work based on low-skilled workers. As a result, it could evolve into project management. The qualification of these workers was assumed to be strategic by the administration, which also accepted a re-elaboration of the structure (from hierarchical centralization to evolving into a “prismatic” structure that would allow for success based on “project management”). Training would follow the “ANEFA” model, of on-the-job learning, according to the four skills considered as core (project - Saber+): (i) literacy (knowing more); (ii) citizenship (participation in business life); (iii) numeracy (mathematics for life); (iv) technology (judicious use of ICTs). The workers wrote their manual personalized work on the topic of “accommodation management”. Organizational reconversion increased management autonomy, with a dynamic focus on the events and company meetings market, while the effectiveness and productivity of accommodation workers increased, with them being hired as permanent workers and transferred to situation of multi-purpose employees, capable of serving tables and supporting breakfast services. Organizational change, developed as a function of resolving a single initial problem (Kotter, 1995; Weick and Quinn, 1999), in fact involved the entire structure and led it to a stage of organizational learning (Senge, 1990).

Insulin biotrapping using plasmofluidic optical fiber chips: A benchmark

Plasmonic optical fiber-based biosensors are currently in their early stages of development as practical and integrated devices, gradually making their way towards the market. While the majority of these biosensors operate using white light and multimode optical fibers (OFs), our approach centers on single-mode OFs coupled with tilted fiber Bragg gratings (TFBGs) in the near-infrared wavelength range. Our objective is to enhance surface sensitivity and broaden sensing capabilities of OF-based sensors to develop in situ sensing with remote interrogation. In this study, we comprehensively assess their performance in comparison to the gold-standard plasmonic reference, a commercial device based on the Kretschmann-Raether prism configuration. We present their refractive index sensitivity and their capability for insulin sensing using a dedicated microfluidics approach. By optimizing a consistent surface biotrapping methodology, we elucidate the dynamic facets of both technologies and highlight their remarkable sensitivity to variations in bulk and surface properties. The one-to-one comparison between both technologies demonstrates the reliability of optical fiber-based measurements, showcasing similar experimental trends obtained with both the prismatic configuration and gold-coated TFBGs, with an even enhanced limit of detection for the latter. This study lays the foundation for the detection of punctual molecular interactions and opens the way towards the detection of spatially and temporally localized events on the surface of optical probes.

Synthesis, Characterization, and Applications of Rare-Earth-Based Complexes with Antibacterial and Antialgal Properties.

The pursuit of environmentally friendly and highly effective antifouling materials for marine applications is of paramount importance. In this study, we successfully synthesized novel rare earth-based complexes by coordinating cerium (Ce III), samarium (Sm III), and europium (Eu III) with pyrithione (1-hydroxy-2-pyridinethione; PT). Extensive characterizations were performed, including single-crystal X-ray analysis, which revealed the intriguing binuclear structure of these complexes. This structural motif comprises two rare-earth ions intricately double-bridged by two oxygen atoms from the PT ligand, resulting in a distinctive and intriguing geometry. Furthermore, the central rare earth ion is surrounded by three sulfur atoms and two additional oxygen atoms, forming a unique distorted bicapped trigonal prismatic configuration. Compared with conventional antifouling biocides such as sodium pyrithione (NaPT), copper pyrithione (CuPT), and zinc pyrithione (ZnPT), these newly synthesized rare-earth complexes exhibited a remarkable boost in their in vitro antibacterial efficacy against both Gram-positive and Gram-negative bacteria. Additionally, these complexes demonstrated significant potential as antialgal agents, displaying impressive activity against marine planktonic organisms. These findings underscore the promising application prospects of these rare-earth complexes in the field of marine antifouling.

Influence of the ancillary ligand on the crystalline structures and magnetic properties of mesaconato‐bridged Mn coordination polymers

Abstract{[Mn(mes)(dmb)(H2O)] ⋅ H2O}n (1) and [Mn(mes)(bpy)]n (2); (mes=mesaconato; dmb=5,5’‐dimethyl‐2,2’‐bipyridine; bpy=2,2’‐bipyridine), were obtained by self‐assembly solution reaction at ambient conditions, and structurally characterized by single crystal X‐ray diffraction. 1 crystallizes in an orthorhombic system with a Pbca space group and forms a one‐dimensional (1D) coordination polymer; the six‐coordinated Mn(II) centers display a distorted‐trigonal prismatic configuration. 2 crystallizes in an orthorhombic system with a P21212 space group yielding a two‐dimensional (2D) coordination array, their metal centers having a distorted octahedral geometry. Magnetic susceptibility measurements reveal that 1 is paramagnetic, while 2 shows weak antiferromagnetic coupling.

Optimization study of obstacles in T–T mixing channel at low Reynolds numbers

AbstractIn this study, numerical simulations were conducted to optimize obstacle geometry for improving mixing in T–T mixers at low Reynolds numbers (2 < Re < 100). The study considered obstacles of cylindrical and prismatic shapes and optimized their pitch and geometrical parameters for enhanced mixing. For cylindrical obstacles, the optimized configuration resulted in symmetrical recirculation zones at Re > 30, which led to larger mixing qualities of 80% and 85% for Re values above 30 and 50, respectively. However, the pressure drop increased in the optimized T–T mixer due to the larger size of the obstacles. On the other hand, in the case of prismatic obstacles, the mixing qualities of 80% and 85% were achieved only at relatively higher Re values of 70 and 90, respectively. The recirculation zone formed behind the obstacle was asymmetric due to the asymmetrical shape of the optimized prism. At higher Re, the optimized cylindrical obstacle configuration resulted in better mixing than the prismatic configuration. However, the choking effect in the former increased the pressure drop.

Computational investigation of the structures, properties, and host‐guest chemistry of prism[n]arenes

AbstractThe discovery of new and functional macrocyclic host compounds is an important part of supramolecular chemistry. Since the experimental synthesis, prism[n]arenes (Pr[n]As), a class of naphthol‐based macrocyclic arenes, have attracted much attention. In this work, from the perspective of theoretical calculation and research, Pr[n]As (n = 4 ~ 7) were studied by density functional theory (DFT) calculations and molecular dynamics (MD) simulations. The prismatic configuration isomers, electronic structures, absorption spectra, and host‐guest chemistry were discussed thoroughly. DFT calculation results showed that 1,5‐, 3,7‐, and “hybrid” 15,37‐Pr[n]As were the most representative configurations with the rigid prismatic molecular skeleton. Based on time‐dependent density functional theory (TD‐DFT), the absorption spectra of Pr[n]As were all in the range of ultraviolet light which were mainly attributed to π‐π* transitions. The molecular cavities of Pr[n]As were electron‐rich and capable of accommodating a variety of cations or electron‐conjugated molecules. MD simulation results showed that a Pr[n]A molecule was able to capture the guest molecule into its molecular cavity and maintain in the state of equilibrium in solvents.

Synthesis, Crystal Structure and Thermal decomposition of Copper(II) and Manganese(II) Complexes Based on Bipyridine Dicarboxylate and 1,10-Phenanthroline

Two novel transition metal complexes of the formulae [Cu(5,5′-bpdc)(phen)]n (1) and [Mn(6,6′-bpdc)(phen)(H2O)]·H2O (2) (where phen = 1,10-phenanthroline, 5,5′-H2bpdc = 2,2′-bipyridine-5,5′-dicarboxylic acid, 6,6′-H2bpdc = 2,2′-bipyridine-6,6′-dicarboxylic acid) were synthesized by hydrothermal reaction. The complexes were characterized by elemental analysis, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetry and differential scanning calorimetry. The X-ray crystallographic investigation reveals that 1 is a coordination polymer, and its asymmetric structural units are connected by oxygen atoms in the carboxyl group of 5,5′-bpdc2– anion. 2 is a heptacoordination monomer complex with mono-capped trigonal prismatic configuration and its mononuclear molecules are connected by hydrogen bonds to form supramolecular structure. The result of fluorescence shows that 2 has fluorescent property.

Intrinsic Magnetic (EuIn)As Nanowire Shells with a Unique Crystal Structure.

In the pursuit of magneto-electronic systems nonstoichiometric magnetic elements commonly introduce disorder and enhance magnetic scattering. We demonstrate the growth of (EuIn)As shells, with a unique crystal structure comprised of a dense net of Eu inversion planes, over InAs and InAs1-xSbx core nanowires. This is imaged with atomic and elemental resolution which reveal a prismatic configuration of the Eu planes. The results are supported by molecular dynamics simulations. Local magnetic and susceptibility mappings show magnetic response in all nanowires, while a subset bearing a DC signal points to ferromagnetic order. These provide a mechanism for enhancing Zeeman responses, operational at zero applied magnetic field. Such properties suggest that the obtained structures can serve as a preferred platform for time-reversal symmetry broken one-dimensional states including intrinsic topological superconductivity.

Study on the Bandgap Characteristics and Vibration-Reduction Mechanism of Symmetric Power-Exponent Prismatic Phononic Crystal Plates

In this paper, a symmetric power-exponent prismatic phononic crystal configuration was proposed for the vibration reduction of thin plate structures, and the mechanism of bandgap generation and the influencing factors of the band gaps were analyzed. The results showed that the proposed symmetric power-exponent prismatic phononic crystal structure has three complete band gaps of bending waves, where the width of the second band gap can go up to 1639 Hz. The band gaps of bending waves of the phononic crystal were verified using a combination of numerical simulations and experimental methods, and subsequently, the bandgap characteristics and energy-focusing effect of the phononic crystals were effectively used to suppress the bending vibration of the thin plate. With the increase in prismoid height of the structure, the width of the first band gap expanded, while the bandwidths of the other two band gaps narrowed down. It was observed that an increase in the power of the power-exponent prismoid would reduce the starting and ending frequencies of the band gaps, whereas an increase in the prismoid edge thickness would weaken the energy-focusing effect and narrow the band gaps gradually. Our research results provide a new technique and a pathway to realize vibration reduction in thin plate structures.

Research on the flow field and film cooling effectiveness of the endwall with swirling film cooling

In order to obtain the effect of endwall secondary flow on the swirling film cooling, a geometric model of cascade is established to research the endwall swirling film cooling and swirling flow induced by prismatic jet impingement configurations. Numerical simulation is applied to investigate three jet flow configurations on the endwall film cooling performance at the compound angles of film hole γ = 0° and 30° and blowing ratios M = 0.5–2.0. The influence of complex vortex structures near endwall for jet flow is analyzed in detail; the strong transverse cross flow near the endwall is the main reason affecting the film cooling effectiveness. The variation laws of endwall film cooling effectiveness with the compound angle of film hole, jet flow configuration, and the blowing ratio are obtained. As the blowing ratio increases, the spanwise average film cooling effectiveness increases first and then decreases. While the blowing ratio is M =1.0, the endwall film cooling effectiveness is the best. Increasing the compound angle of the film hole leads to a decrease in the endwall cooling effectiveness. The spanwise average cooling effectiveness of γ = 30° decreases by 35% compared to the γ = 0°.

Large-Amplitude Vibrations of a Slender Cantilevered Beam

We present a geometrically exact beam model for a cantilevered beam undergoing large-amplitude motions, motivated by recent wind-energy capture systems that exploit vortex-induced vibrations. The derivation of this model leads to a single nonlinear 2nd-order ordinary differential equation that appears similar to a Duffing oscillator with additional nonlinear acceleration terms. For prismatic configurations, the formulation is characterized by its linear natural frequency and a normalization constant of the shape-function. A brief parametric study is conducted to demonstrate the softening effects of the nonlinear acceleration terms. Continuation methods are used to construct the amplitude versus forcing frequency plots to capture the nonlinear response.

Fabrication and testing of sodium-ion full cell with P2-Na0.67 Ni0.167Co0.167 Mn0.67O2 (Na-NCM) and hard carbon in coin cell and 2 Ah prismatic cell configuration

Fabrication of sodium-ion full cell (SIFC) with optimized anode and cathode material is in the initial phases. The successful fabrication of full cell is depended on effective improvement in electrode materials and performance of sodium-ion half-cells. Cathode material plays crucial role in the performance of full cell. Sodium-ion full cell was fabricated based P2-type Na0.67Ni0.167Co0.167Mn0.67O2 (Na-NCM) material synthesized by sol-gel process and commercially available hard carbon. The electrochemical properties of Na-NCM material and hard carbon were systematically investigated. The hard carbon material achieved a reversible capacity of 210.82 mAh g−1 with initial columbic efficiency of 81.15% in Na/Hard Carbon half-cell. The Na-NCM material exhibits a discharge capacity of 149.27 mAh g−1 at C/20 rate in Na/Na-NCM half cell. The fabricated SIFC in coin cell configuration delivers a specific capacity of 74.6 mAh g−1 at C/20 rate, with 40% of the initial discharge capacity delivered after 100 cycles at C/20 and the columbic efficiency is more than 90%. The coin cell in full cell configuration displays reasonable performance at the rates of C/20 to 3C indicating the capability of high rate performance of anode and cathode materials. The first discharge capacity of fabricated SIFC in prismatic configuration is 2.16Ah.

Experimental Study on Influence of Temperature and C-Rate of Discharge on Performance of In-House-Fabricated 30-Ah Li-Ion Prismatic Cell Made With Lithium Iron Phosphate and MCMB

Abstract An experimental study was carried out to quantify the influence of temperature and different C-rate of discharge on in-house fabricated lithium-ion (Li-ion) cell. A 30-Ah Li-ion cell is made of lithium iron phosphate (LFP) cathode and meso carbon microbeads (MCMB) anode in prismatic configuration. The capability of Li-ion cell is defined by discharge capacity, voltage, and power at different C-rate of discharge. Influence of 4 different current rates (C/5, C/2, 1C, and 2C) at 5 different temperatures (–20, 0, 20, 40, and 60 °C) were studied. High discharge rate increases the current density of cell which affect mass transport at electrode surface and electrolyte. Increased ohmic and concentration polarization at a high rate of discharge decrease the original capacity. The average discharge voltage of the cell is reduced gradually as operating temperature drops to below 20 °C. Electrochemical impedance (EI) were measured on Li-ion cell in the different frequency domain at different temperatures (–20, 0, 20, and 60 °C). The obtained impedance spectra were examined with an equivalent circuit using the Zman software. The ohmic and charge-transfer resistance displayed a solid dependence with respect to temperature.

Determination of the Influence of Ventilation Device Geometry on Inertia of the Brake Disc

The variety of brake discs is determined by the presence of different geometries of the ventilation device. Modern brake discs are subdivided according to the geometry of the ventilation device by the presence of fins, which form channels and studs for heat transfer to the cooling air. In turn, ventilation channels can be radial and curved. Studs are subdivided by geometry into cylindrical, prismatic and complex configuration. The paper proposes the calculation of the power required to overcome the inertial forces of the brake disc for various variants of the ventilation device. The power expended to overcome the inertial forces of a brake disc with radial channels is 44 % less than that of a brake disc with curved channels. Brake discs with a ventilation device with prismatic studs have 1.22 times less power required to overcome inertial forces than with cylindrical studs and 1.31 times with DBA studs. When comparing the results of the method for determining the moments of inertia of brake discs with various ventilation devices and CFD models of similar brake discs created in the ANSYS Workbench Mechanical program, the discrepancy was 5.52 %. The study shows the dependence of the power of overcoming inertia forces on the number of ribs. With an increase in the number of ribs by 60, the power to overcome the inertial forces of the radial channels of the disk increased by 1.16 times, while the power of the curved channels of the disk increased by 1.07 times. With an increase in the number of studs by 50 pieces for a disc with cylindrical studs of the apparatus, the power expended to overcome inertial forces increases by 1.15 times, while for prismatic studs there is an increase of 1.05 times. With an increase in the number of studs by 50 pieces, the power to overcome the inertial forces of the ventilated brake disc from DBA increases by 1.17 times. When designing ventilation brake discs, in addition to the heat dissipation parameters, it is necessary to take into account the parameters of the power to overcome the inertial forces of the brake discs, which affect the operational parameters of the braking system as a whole.

Gold Nanorod Assisted Enhanced Plasmonic Detection Scheme of COVID-19 SARS-CoV-2 Spike Protein.

The beautiful interplay between light and matter can give rise to many striking physical phenomena, surface plasmon resonance (SPR) being one of them. Plasmonic immunosensors monitor refractive index changes that occur as a result of specific ligand–analyte or antibody–antigen interactions taking place on the sensor surface. The coronavirus disease (COVID‐19) pandemic has jeopardized the entire world and has resulted in economic slowdown of most countries. In this work, a model of a sandwich plasmonic biosensor that utilizes gold nanorods (Au NRs) for the detection of COVID‐19 SARS‐CoV‐2 spike protein is presented. Simulation results for different prismatic configurations for the basic Kretschmann layout are presented. It is found that a BK7 glass prism‐based SPR sensor has an incremental sensitivity of 111.11 deg RIU−1. Additionally, using Comsol Multiphysics the electric field enhancement observed for various aspect ratios and layouts of Au NRs are discussed in depth.

Surface plasmon resonance measurement of arsenic in low concentration using polypyrrole-graphene quantum dots layer

A surface plasmon resonance method based on a prismatic configuration can be considered as a versatile accurate technique, which can be utilized in detecting chemical toxins. In this study, layers of polypyrrole-graphene dots nanocomposite were produced at different deposition times using the electrodeposition method. Characterization methods such as the field emission-scanning microscopy, X-ray diffraction spectroscopy, and the Fourier transform infrared spectroscopy were employed to obtain and verify the morphology and chemical elements present in the composite layer. The thickness and refractive index of polypyrrole-graphene quantum dots layer ranged between 3.2 nm and 65.2 nm and 1.6895+i 0.112 to 1.6076+i 0.163, respectively. The layer was utilized to measure the low concentration of arsenic (As+3) ions in the range of 0.005–10 ppm and the results have been compared with the response of sensor in the presence of mercury (Hg+2) and lead (Pb+2) ions. However, it must be noted that the sensor’s limit was 0.005 ppm, and the sensitivity of arsenic detection was larger than that of mercury and lead ions.

Octacoordinated tin(IV) complexes bearing oxy-p-benzoquinone and oxy-p-iminobenzoquinone ligands: Structural investigations and dynamics of coordination sphere in solution

Two new hypercoordinated tin(IV) complexes bearing 2-hydroxy-3,6-di-tert-butyl-p-benzoquinone (L1H) and 2-hydroxy-3,6-di-tert-butyl-N-phenyl-p-iminobenzoquinone (L2H) ligands were synthesized and investigated using IR-, UV–Vis, NMR spectroscopy and X-ray diffraction. The rare examples of octacoordinated tin compounds are realized by four bidentate ligands L1 (in 1) or L2 (in 2) bonded with metal center. Complexes are characterized by irregular bicapped trigonal prismatic distorted toward the idealized dodecahedron geometry of coordination polyhedron in crystals according to the X-ray diffraction. The dynamic transformation between bicapped trigonal prismatic and dodecahedron configurations of coordination polyhedra was found and investigated in solution of 1 and 2 by means of Variable Temperature NMR spectroscopy.

Interfacial Shear Bond Strength between Steel H-Piles and Polymer Concrete Jackets

Steel H-piles have been used widely in bridge construction throughout the U.S. because of their relatively large load-carrying capacity while occupying a small area. However, many H-piles suffer from corrosion, which may lead to abrupt collapse. A cost-effective repair technique, including encasing the corroded region of the steel pile into a concrete jacket, which acts as an alternative load path for the applied axial load, has been used by several state Departments of Transportation. Methyl methacrylate polymer concrete (MMA-PC) is a type of concrete that is commonly used as a repair material. However, there is limited research on the assessment of bond strength between MMA-PC and steel elements. This paper investigates experimentally the bond behavior of seven full-scale steel H-piles encased in concrete jackets. The jackets were cast using either MMA-PC or Portland cement concrete (CC). Different embedment lengths of 63.5 mm (2.5 in.), 127 mm (5 in.), and 190.5 mm (7.5 in.) were used for the MMA-PC and one embedment length of 254 mm (10 in.) was used for the CC jacket. Cylindrical and prismatic jacket configurations were used and tested using push-out. The experimental results revealed that using the MMA-PC jacket was more effective compared with the CC jacket in relation to the load-carrying capacity. For design purposes, a shear bond stress of 2.96 MPa [0.43 kips per square inch (ksi)] can be used for MMA-PC jackets having an embedment length of at least 127 mm (5 in.) whereas a value of 0.83 MPa (0.12 ksi) can be used for CC.

A capped trigonal prismatic cobalt(ii) complex as a structural archetype for single-ion magnets.

Two mononuclear, seven-coordinate Co(ii) and Fe(ii) complexes [CoII(BPA-TPA)](BF4)2 (1-Co) and [FeII(BPA-TPA)](ClO4)2 (2-Fe) with a capped trigonal prismatic coordination geometry have been synthesized from the pentapyridyldiamine (BPA-TPA) ligand. 1-Co exhibits easy plane anisotropy in which slow magnetic relaxation is observed under a 1.0 kOe dc field. It is the first example of a single-ion magnet (SIM) of a 3d transition metal ion with a capped trigonal prismatic configuration. 2-Fe is not a SIM at 1.8 K.

Structural Parameters and Thermodynamics of the Formation of Molecular Water Clusters

The formation of molecular water clusters is simulated using the theoretical density functional theory/ B3LYP/6-311+G(d,p) method. The spatial configurations of 29 clusters with 2 to 28 water molecules are calculated. The dipole moments, the complete complex-formation enthalpy, and the enthalpy of the successive joining of water molecules are determined with the basis-set superposition error taken into account. The features of the geometric structure and the hydrogen-bond strength of water clusters are analyzed on the basis of the obtained theoretical data. The complex-formation enthalpy is revealed to depend periodically on the number of water molecules in a cluster. It is found that clusters with molecules whose number is a multiple of four are energetically most advantageous. When a molecular cluster is built starting with 17 molecules, the cluster structure is changed, resulting in that one end of the complex rolls up into a prismatic configuration.