Planar Part Research Articles

Unveiling the molecular association of novel benzohydrazide-substituted Schiff base complexes with human serum albumin

So far, various Schiff base zinc (II) complexes with potential applications in biomedicine have been reported as medicinal agents in diagnosis, imaging and treatment of diseases such as cancer and Alzheimer. Therefore, it is important to understand their interaction with carrier proteins, such as human serum albumin (HSA). The present paper focuses on synthesis, characterization and the binding interactions between HSA and two novel Schiff-base complexes, [Zn(SL)(N-N)](NO3)2 (SL = Schiff base ligand; N-N = 2,2′-bipyridine (bpy, C1), 1,10-phenanthroline (phen, C2)), using experimental and molecular docking techniques. The antioxidant performance of compounds increased as follows: C2 > C1 > SL. Two complexes quenched the protein fluorescence emission by the same mechanism (static quenching). The binding constant values obtained from the interaction of HSA and complexes were in the ideal range for biological applications (Kb = 0.07 × 104 M−1 for C1, 5.01 × 104 M−1 for C2 at 303 K). The binding of the C1/C2 somewhat reduced the stability of the protein structure and led to a change in polarity around tyrosine and tryptophan. In this research, we found that the increase of the planar aromatic part in the metallodrug can affect the strength of the interaction, the type of force involved during the interaction process, and the medicinal properties such as their antioxidant capabilities.

Learning accurate template matching with differentiable coarse-to-fine correspondence refinement

Template matching is a fundamental task in computer vision and has been studied for decades. It plays an essential role in manufacturing industry for estimating the poses of different parts, facilitating downstream tasks such as robotic grasping. Existing methods fail when the template and source images have different modalities, cluttered backgrounds, or weak textures. They also rarely consider geometric transformations via homographies, which commonly exist even for planar industrial parts. To tackle the challenges, we propose an accurate template matching method based on differentiable coarse-to-fine correspondence refinement. We use an edge-aware module to overcome the domain gap between the mask template and the grayscale image, allowing robust matching. An initial warp is estimated using coarse correspondences based on novel structure-aware information provided by transformers. This initial alignment is passed to a refinement network using references and aligned images to obtain sub-pixel level correspondences which are used to give the final geometric transformation. Extensive evaluation shows that our method to be significantly better than state-of-the-art methods and baselines, providing good generalization ability and visually plausible results even on unseen real data.

Lithospheric contraction concentric to Tharsis: 3D structural modeling of large thrust faults between Thaumasia highlands and Aonia Terra, Mars

Large thrust faults on Mars are caused by lithospheric planetary contraction. The geometry of these faults is linked with the mechanical behavior of the lithosphere. Tharsis, the largest volcano-tectonic province on Mars, controls the global tectonic pattern of the planet. Here, we present a study of five large thrust faults concentric to Tharsis, located between the Thaumasia Highlands and the Argyre impact basin. We applied a 3D structural modeling, using a combination of fault-parallel flow and trishear algorithms to estimate the geometry and kinematics of the faults at depth. The modeled faults show an upper planar part dipping 33° to 40°, rooting with a listric geometry into horizontal levels at 13–27 km depth, with fault slips of 801–3366 m. The general out-of-Tharsis vergence, the listric fault geometries and the deepening of the depth of faulting toward Thaumasia outline an incipient thrust wedge architecture. Assuming that the largest faults rooted at the Brittle-Ductile Transition, we calculate a heat flow at the time of faulting of 24–54 mW m−2. The obtained strength envelopes for dry and wet conditions show that all the strength of the lithosphere was located in the upper half of the crust.

Copper(II) Chelates of Schiff Bases Enriched with Aliphatic Fragments: Synthesis, Crystal Structure, In Silico Studies of ADMET Properties and a Potency against a Series of SARS-CoV-2 Proteins.

We report two complexes [Cu(LI)2] (1) and [Cu(LII)2] (2) (HLI = N-cyclohexyl-3-methoxysalicylideneimine, HLII = N-cyclohexyl-3-ethoxysalicylideneimine). The ligands in both complexes are trans-1,5-N,O-coordinated, yielding a square planar CuN2O2 coordination core. The molecule of 1 is planar with two cyclohexyl groups oriented to the opposite sites of the planar part of a molecule, while the molecule of 2 is significantly bent with two cyclohexyl groups oriented to the same convex site of a molecule. It was established that both complexes in MeOH absorb in the UV region due to intraligand transitions and LMCT. Furthermore, the UV-vis spectra of both complexes revealed two low intense shoulders in the visible region at about 460 and 520 nm, which were attributed to d-d transitions. Both complexes were predicted to belong to a fourth class of toxicity with the negative BBB property and positive gastrointestinal absorption property. According to the molecular docking analysis results, both complexes are active against all the applied SARS-CoV-2 proteins with the best binding affinity with Nsp 14 (N7-MTase), PLpro and Mpro. The obtained docking scores of complexes are either comparable to or even higher than those of the initial ligands. Complex 1 was found to be more efficient upon interaction with the applied proteins in comparison to complex 2. Ligand efficiency scores for the initial ligands, 1 and 2 were also revealed.

A novel method to control stress distribution and machining-induced deformation for thin-walled metallic parts

Abstract In the precision machining of thin-walled planar components, the initial residual stress of the workpiece could lead to subsequent deformation after machining, which influences the geometrical accuracy of the final parts. Generally, conventional methods, such as stress-relief annealing and vibration stress relief, are implemented to reduce the magnitude of the residual stress. However, the distribution of the residual stress, which is more significant to the machining accuracy for thin-walled parts, is difficult to be adjusted in these methods. This article proposes a novel method to control the stress distribution and magnitude during the manufacturing process and thus reduce the machining-induced deformation for the thin-walled planar part of pure copper. In this method, symmetrical distribution of residual stress is introduced by multi-pass rolling, quenching, stress-relief annealing, and turnover turning. The stress field and deformation of the part are predicted by finite element modeling in the whole process. The part deformation after machining is verified by the experiments. The results show that compared with the traditional stress-relief annealing, this novel method could reduce the part deformation after machining and improve the geometrical accuracy for thin-walled parts.

Tolerance analysis of planar parts with skin modeling considering spatial distribution characteristics of surface morphology and local surface deformations

Purpose This paper aims to develop a method to improve the accuracy of tolerance analysis considering the spatial distribution characteristics of part surface morphology (SDCPSM) and local surface deformations (LSD) of planar mating surfaces during the assembly process. Design/methodology/approach First, this paper proposes a skin modeling method considering SDCPSM based on Non-Gaussian random field. Second, based on the skin model shapes, an improved boundary element method is adopted to solve LSD of nonideal planar mating surfaces, and the progressive contact method is adopted to obtain relative positioning deviation of mating surfaces. Finally, the case study is given to verify the proposed approach. Findings Through the case study, the results show that different SDCPSM have different influences on tolerance analysis, and LSD have nonnegligible and different influence on tolerance analysis considering different SDCPSM. In addition, the LSD have a greater influence on translational deviation along the z-axis than rotational deviation around the x- and y-axes. Originality/value The surface morphology with different spatial distribution characteristics leads to different contact behavior of planar mating surfaces, especially when considering the LSD of mating surfaces during the assembly process, which will have further influence on tolerance analysis. To address the above problem, this paper proposes a tolerance analysis method with skin modeling considering SDCPSM and LSD of mating surfaces, which can help to improve the accuracy of tolerance analysis.

FCA: Learning a 3D Full-Coverage Vehicle Camouflage for Multi-View Physical Adversarial Attack

Physical adversarial attacks in object detection have attracted increasing attention. However, most previous works focus on hiding the objects from the detector by generating an individual adversarial patch, which only covers the planar part of the vehicle’s surface and fails to attack the detector in physical scenarios for multi-view, long-distance and partially occluded objects. To bridge the gap between digital attacks and physical attacks, we exploit the full 3D vehicle surface to propose a robust Full-coverage Camouflage Attack (FCA) to fool detectors. Specifically, we first try rendering the nonplanar camouflage texture over the full vehicle surface. To mimic the real-world environment conditions, we then introduce a transformation function to transfer the rendered camouflaged vehicle into a photo-realistic scenario. Finally, we design an efficient loss function to optimize the camouflage texture. Experiments show that the full-coverage camouflage attack can not only outperform state-of-the-art methods under various test cases but also generalize to different environments, vehicles, and object detectors.

A Computer-Aided Design-Based Tolerance Analysis of Assemblies With Form Defects and Deformations of Nonrigid Parts

Abstract Product assemblability and functional behavior are affected by geometric deviations. These deviations consist of manufacturing errors and part deformation defects caused by external loads. Taking the sources of deviations into account in tolerance analysis yields not only to more precise and reliable results but also to more complex tasks. In this context, the modeling of assembly parts with defects in a Digital MockUp (DMU) is quite promising. In this article, an integrated decision support tool is proposed to consider the causes of multiple defects, such as tolerances and external mechanical loads, in the tolerancing process. The worst-case concept and the small displacement torsor (SDT) are used to model rigid parts with orientation and positional defects. To model the part with form defects, random positions of each toleranced face points are determined using the Gaussian perturbation method (GPM) and considering the tolerance zone limits. A computer-aided design (CAD) method based on the B-spline interpolation allows the reconstruction of realistic surfaces of parts with form defects. Realistic configurations of nonrigid components subjected to external mechanical loads are determined using the finite element analysis (FEA). The realistic assembly configurations are performed by updating the mating constraints between planar and cylindrical parts. The proposed method considers all tolerance types on CAD models (positional, orientation, and form defects) and part deformations. The tolerance analysis is performed to check the compliance with the functional requirement (FR) and to correct the initial tolerance values. An industrial case study is used to validate the steps of the proposed tolerancing method.

Disentangling the Regge Cut and Regge Pole in Perturbative QCD.

The high-energy limit of gauge-theory amplitudes features both a Regge pole and Regge cuts. We show how to disentangle these, and hence how to determine the Regge trajectory beyond two loops. While the nonplanar part of multiple Reggeon t-channel exchange forms a Regge cut, the planar part contributes to the pole along with the single Reggeon. With this, we find that the infrared singularities of the trajectory are given by the cusp anomalous dimension. By matching to recent QCD results, we determine the quark and gluon impact factors to two loops and the Regge trajectory to three loops.

Dye-Sensitized Solar Cell (DSSC) Applications based on Cyano Functional Small Molecules Dyes

This work focused on synthesizing of the electro active two small molecules ((2E)-2-Cyano-3-[4'-(2,5-di-2 thienyl-1H-pyrrol-1-yl) biphenyl-4-yl] acrylic acid (MC-20) (2E) -2-Cyano-3-5-[4-(2,5-di-2-thienyl-1H pyrrol-1 yl) phenyl] -2-thienyl acrylic acid (MC-28)) consisting of planar molecule part with different absorptions-emissions energy levels and applications of these small molecules in DSSC device to understand their performance. The optical properties of MC-20

Dps protein localization studies in nanostructured silicon matrix by scanning electron microscopy

The present work is related to the microscopic studies of the morphology of the planar and inner part of silicon nanowires arrays before and after immobilization with a natural nanomaterial, Dps protein of bacterial origin. Silicon nanowires were formed by metal-assisted wet chemical etching. To obtain the recombinant protein, Escherichia coli cells were used as excretion strain and purification were carried out using chromatography. The combination of silicon nanowires with protein molecules was carried out by layering at laboratory conditions followed by drying under air. The resulting hybrid material was studied by high-resolution scanning electron microscopy. Studies of the developed surface of the nanowires array were carried out before and after combining with the bioculture. The initial arrays of silicon wireshave a sharp boundaries in the planar part and in the depth of the array, transition layers are not observed. The diameter of the silicon nanowires is about 100 nm, the height is over a micrometer, while the distances between the nanowires are several hundred of nanometers. The pores formed in this way are available for filling with protein during the immobilization of protein.The effectiveness of using the scanning electron microscopy to study the surface morphology of the hybrid material “silicon wires – bacterial protein Dps” has been demonstrated. It is shown that the pores with an extremely developed surface can be combined with a bio-material by deposition deep into cavities. The protein molecules can easily penetrate through whole porous wires matrix array. The obtained results demonstrate the possibility of efficient immobilization of nanoscaled Dps protein molecules into an accessible and controllably developed surface of silicon nanowires.

Superconformal duality-invariant models and mathcal{N} = 4 SYM effective action

We present mathcal{N} = 2 superconformal U(1) duality-invariant models for an Abelian vector multiplet coupled to conformal supergravity. In a Minkowski background, such a nonlinear theory is expected to describe (the planar part of) the low-energy effective action for the mathcal{N} = 4 SU(N) super-Yang-Mills (SYM) theory on its Coulomb branch where (i) the gauge group SU(N) is spontaneously broken to SU(N − 1) × U(1); and (ii) the dynamics is captured by a single mathcal{N} = 2 vector multiplet associated with the U(1) factor of the unbroken group. Additionally, a local U(1) duality-invariant action generating the mathcal{N} = 2 super-Weyl anomaly is proposed. By providing a new derivation of the recently constructed U(1) duality-invariant mathcal{N} = 1 superconformal electrodynamics, we introduce its SL(2, ℝ) duality-invariant coupling to the dilaton-axion multiplet.

Efficient storage and recovery of waste heat by phase change material embedded within additively manufactured grid heat exchangers

The low thermal conductivity of organic phase change materials (PCMs) hinders their usage for energy storage purposes. We demonstrate a compact PCM-based thermal battery that employs three-dimensional (3D) printed metal surfaces for a robust thermal energy storage and recovery. The thermal battery could be utilized to store excess heat from various sources. The concept includes organic paraffin and fatty acid PCMs embedded within aluminum silicon alloy grid heat exchangers (GHE) produced via additive manufacturing. The heat exchangers consist of two parts: (i) a planar part with embedded water channels and (ii) a surface extrusion grid outside the planar part embedded in the PCM storage system. Three different grid designs are investigated and compared with a simple planar heat exchanger (PHE) without grid extension. The charging and discharging processes of the thermal battery were analyzed experimentally. The laboratory scale experiments reveal that the 3D printed grid surfaces of GHE significantly reduce the charging and discharging time from more than 240 min to less than 20 min. In contrast to PHE, the GHE may increase thermal power by a factor of ∼20 from 35 W to 670 W. Furthermore, the grid structure positively restrains the natural convection flow of the PCM melt, increasing conduction in the highly conductive grid structure and resulting in high charging-discharging power of the thermal battery. The swift charging and discharging with high power and energy density make the compact grid thermal battery a promising solution for thermal energy management.

Virtual and Physical Prototyping of Reconfigurable Parallel Mechanisms with Single Actuation

The paper presents novel models of reconfigurable parallel mechanisms (RPMs) with a single active degree-of-freedom (1-DOF). The mechanisms contain three to six identical kinematic chains, which provide three (for the tripod) to zero (for the hexapod) uncontrollable DOFs. Screw theory is applied to carry out mobility analysis and proves the existence of controllable and uncontrollable DOFs of these mechanisms. Each kinematic chain in the synthesized mechanisms consists of planar and spatial parts. Such a design provides them with reconfiguration capabilities even when the driving link is fixed. This allows reproduction of diverse output trajectories without using additional actuators. In this paper, the model of a mechanism with six kinematic chains (hexapod) has been virtually and physically prototyped. The designing and assembling algorithms are developed using the detailed computer-aided design (CAD) model, which was further used to carry out kinetostatic analysis considering complex geometry of mechanism elements and friction among all contacting surfaces of joints. The developed virtual prototype and its calculation data have been further applied to fabricate mechanism elements and assemble an actuated full-scale physical prototype for future testing.

Design and 3D Printing of Controllable and Gradient Porous Supports for Solid Oxide Fuel Cells

A controllable and gradient porous structure is desirable for many applications including solid oxide fuel cells (SOFC) electrodes. A SOFC contains a minimum three basic ceramic thin films with a thin yet dense electrolyte layer separates the adjacent porous anode and cathode layers. In general, the thinner the electrolyte layer, the smaller the ohmic resistance would be. The anode and cathode layers need to be porous so to allow gases (e.g. H2 and O2) to easily penetrate to the triple-phase boundary (TPB). At the same time the anode and cathode layers serve as the paths of removing the electrons generated at the TPBs. Properly design and fabricated porous electrode microstructure could greatly increase the connectedness of gas, electrons and/or protons/oxygen ions, and therefore reduce the gas diffusion and ohmic resistances of the SOFC electrodes and boost the overall fuel cell performance.Although there are electrolyte- and cathode- supported SOFC developers, the most used configuration is anode-supported or additional component-supported, for example metal-supported or ceramic-supported with a planar or tubular geometry. Conventionally, the porosity is generated by using sacrificial templates or pyrolyzable pore-formers for pore formation. Pores are formed after the burning off these sacrificial templates or pyrolyzable pore-formers at elevated temperatures. The size, shape and amount of the pore-formers can be controlled. However, the connectivity and orientation of these pores are not easily controllable, leaving significant amount of closed and isolated pores. These isolated and/or closed pores do not contribute to the TBP. Freeze casting of water-based suspension slurries could generate aligned pores, the low connectivity and weak mechanical strength challenges remain.This paper focuses on the design and fabrication of a desired gradient porous microstructure for use as a SOFC support. The pore size and shape, porosity and connectivity could be determined and strictly controlled by design. Tubular and planar parts with metal, cermet and/or ceramic materials are to be fabricated. Additive manufacturing (AM, or 3D printing) process enables the fabrication of the complicated parts with the desired microstructure directly from the computer-aided design (CAD) models. The morphology, porosity, permeability and tortuosity of the 3D printed parts are investigated and results are discussed.

Interaction of new tri-, tetra-, and pentacyclic azaphenothiazine derivatives with calf thymus DNA: Spectroscopic and molecular docking studies

Azaphenothiazines (AZA), modified phenothiazine derivatives, have been reported to exhibit a wide spectrum of biological activities, including anticancer activities, but the mechanisms of their interactions with biomolecules are not fully recognized. In this work, the mode of interaction of selected AZA with calf thymus DNA was investigated using UV–Vis absorption, fluorescence spectroscopy (competition experiment with ethidium bromide, quenching of fluorescence) and molecular docking. The investigated AZA represent dipyrido[3,4-b;3′4′-e][1,4]thiazine, quino[3,2-b]benzo[1,4]thiazine and diquino[3,2-b;2′,3′-e][1,4]thiazine possessing tricyclic, tetracyclic and pentacyclic ring system with the additional N,N-dimethylaminopropyl group at the nitrogen atom in the 1,4 thiazine ring. The results obtained from spectroscopic studies showed that AZA bind to DNA by insertion of a fragment of the fused rings system between the base pair stack in the double helix of DNA. In addition, the number of rings in the AZA structures seemed to be related to the strength of the interaction, because pentacyclic AZA (binding constant Kb = 6.31 × 106 L/mol) demonstrated 10-fold higher affinity towards DNA than the tetracyclic AZA and about 100-fold higher affinity than that of tricyclic AZA. The molecular docking results showed that the binding mode of AZA to DNA helix was an intercalation mode with the partial insertion of one planar part of the AZA structure (the pyridine or quinoline ring) into the neighboring bases of one of the DNA chains with additional hydrogen bonding with the minor groove through the positively charged N,N-dimethylaminopropyl group. Chemical potential (μ), chemical hardness (ƞ), electronegativity (χ) and the value of electrons transferred from one system to another (ΔN) calculated from the HOMO and LUMO energies by the density functional theory method indicated that AZA acted as the electron acceptors to the DNA bases.

The role of both intercalation and groove binding at AT-rich DNA regions in the interaction process of a dinuclear Cu(I) complex probed by spectroscopic and simulation analysis

In this research paper, the synthesis process and characterization of a dinuclear Cu(I) phosphine complex, as well as spectroscopic and simulation analysis of its interaction with DNA helix, are presented. The monoclinic phase [Cu(PPh3)(L0.5)(I)]2 with a tetrahedral molecular geometry was elucidated based on X-ray single-crystal diffraction data. The significant association constant (6.88 × 105) and remarkable hyperchromism as obtained from UV–Visible spectra indicated a high binding affinity of the Cu(I) complex for DNA, which is in accordance with both intercalation and groove binding modes. The results of competitive fluorescence experiments along with molecular docking simulation proved that the planar part of the complex can insert into the core of adenine nucleobases and compete with methylene blue for the intercalative binding sites, while the bulky substituent binds in the minor groove of DNA via replacement of Hoechst molecules at A-T rich regions. According to thermodynamic parameters (the negative values of ΔH° and ΔS°), it is quite clear that the interaction process is enthalpy-favored while disfavored by entropy and van der Walls and hydrophobic forces play a major role in stabilization of right-handed B-DNA form during the interaction, as shown in the circular dichroism spectra. Based on the above findings partial intercalation mode at A-T rich region of DNA was proposed. The cytotoxicity and apoptosis results on MCF-7 cell line indicated positive effect of the Cu(I) complex in controlling growth and viability of breast cancer more than cisplatin.

A bijection for essentially 3-connected toroidal maps

We present a bijection for toroidal maps that are essentially 3-connected (3-connected in the periodic planar representation). Our construction actually proceeds on certain closely related bipartite toroidal maps with all faces of degree 4 except for a hexagonal root-face. We show that these maps are in bijection with certain well-characterized bipartite unicellular maps. Our bijection, closely related to the recent one by Bonichon and Lévêque for essentially 4-connected toroidal triangulations, can be seen as the toroidal counterpart of the one developed in the planar case by Fusy, Poulalhon and Schaeffer, and it extends the one recently proposed by Fusy and Lévêque for essentially simple toroidal triangulations. Moreover, we show that rooted essentially 3-connected toroidal maps can be decomposed into two pieces, a toroidal part that is treated by our bijection, and a planar part that is treated by the above-mentioned planar case bijection. This yields a combinatorial derivation for the bivariate generating function of rooted essentially 3-connected toroidal maps, counted by vertices and faces.

Understanding the Impedance of CNOs-Graphene hybrid electrode through both experimental and simulated electrochemical impedance spectrum

Using a combination of experimental measurements and molecular dynamic (MD) simulations, we study the impedance of hybrid electrode composed of graphene and carbon nanometer onions (CNOs). On the experiment’s side, electrochemical measurements are conducted on the electrodde sample prepared from growing CNOs onto the graphitic plane. The general trend of impedance’s variations with frequencies is identified at different temperatures and ion concentration. Parameter fitting of equivalent circuit is accomplished with the assistance from machine learning technique using neural network. On the simulation’s side, electrode geometries including concave slit-pore and convex CNO-pore surfaces are modeled to investigate ion movements. Based on trajectories of ion dynamics, the physical origin of corresponding equivalent circuit component such as constant phase element is revealed. Regarding the geometry of electrode surface, the divide between planar and nonplanar part is observed in terms of charging level and charging time constant. Between the slit-pore and CNO-pore geometries, the differences in impedance spectrum is quantitatively characterized by solving the topology of and parameter of transmission line model of the equivalent circuit. In the branch of transmission line model, the resistance and capacitance are both larger for the space closer to the pore bottom or further from pore mouth.

Spatial Stiffness Analysis of the Planar Parallel Part for a Hybrid Model Support Mechanism

The hybrid aircraft model support mechanism is subjected to six directional forces in the experiment, and high spatial stiffness requirement of the parallel part is the guarantee for the stability of the aircraft model. The purpose of this paper is to obtain a planar parallel part with relatively good spatial stiffness and to explore the influence of components on the stiffness characteristics. We employed screw theory and virtual work principle to establish the spatial stiffness model of two possible parallel parts for the support mechanism. The stiffness characteristics of the two parallel mechanisms were evaluated by a desired trajectory sub-workspace deformation distribution and two novel stiffness indexes. According to deformation distributions of the sub-workspace, the deformation of typeI is smaller than that of type II. The proposed indexes indicate that the influence of the hydraulic cylinder range on the stiffness of type II is more significant; RVR of ASI is 263.5%, RVR of CSI is 18.1%. These reveal type I has better spatial stiffness than type II. The reason is that the guideway of type I provides a part of the ability to resist external forces.