Coplanar Arrangement Research Articles

Change of fundamental properties of dielectric barrier discharge due to the alumina-based barrier layer composition

Dielectric barrier discharges (DBDs) are widely used in various branches of industry. One of the main characteristics of the DBD is the material of the dielectric barrier–in present days, alumina ceramic is the most frequently used material. Basic plasma parameters are affected by the chemical composition of these dielectric barriers, and also by their surface properties. These surface properties are even more dominant in a coplanar arrangement of the DBD (CDBD). Due to this fact, we studied the effect of adding several types of oxides into a pure alumina ceramic (Al2O3). The aim was to determine the impact of the chemical composition of the dielectric barrier and to see complex changes in respect to the surface morphology of the CDBD barrier layer. In the presented study, we focused mainly on determining ignition voltage and quenching voltage. With the help of atomic force microscopy (AFM) images, the results of these measurements were put into correlation with the surface structure of the DBD barrier.

Conformation change significantly affected the optical and electronic properties of arylsulfonamide-substituted anthraquinones.

Drastic changes in the optical and electronic properties of arylsulfonamide-substituted anthraquinones were induced by simple N-methylation. N-Methylation at the congested peri-position of the anthraquinone unit induced a drastic conformational change from a coplanar arrangement to an orthogonal relationship between the anthraquinone scaffold and arylsulfonamide substituents. As a result, the contribution of the substituents on the anthraquinone unit was spectroscopically suppressed, as demonstrated by UV-Vis absorption spectra and cyclic voltammograms.

Comparison of the Operating Conditions of Electric Arc Furnaces with Short and Long Arc Discharges

A mathematical model is developed to describe the electromagnetic energy transfer between the phases of an electric arc furnace. This model is used to study the efficiency of operation of a DSP-100 electric arc furnace with the coplanar arrangement of a secondary current lead for short, medium, and long arc discharges. The energy processes in the furnace are found to be determined by both the potential gradients in arc discharges and the electromagnetic coupling of the phases, which causes redistribution of the total power released in arc discharges between the phases. Recommendations for the application of a phase-by-phase controlled reactor during long-arc operation are made.

Preclinical dose verification using a 3D printed mouse phantom for radiobiology experiments.

Dose verification in preclinical radiotherapy is often challenged by a lack of standardization in the techniques and technologies commonly employed along with the inherent difficulty of dosimetry associated with small-field kilovoltage sources. As a consequence, the accuracy of dosimetry in radiobiological research has been called into question. Fortunately, the development and characterization of realistic small-animal phantoms has emerged as an effective and accessible means of improving dosimetric accuracy and precision in this context. The application of three-dimensional (3D) printing, in particular, has enabled substantial improvements in the conformity of representative phantoms with respect to the small animals they are modeled after. In this study, our goal was to evaluate a fully 3D printed mouse phantom for use in preclinical treatment verification of sophisticated therapies for various anatomical targets of therapeutic interest. An anatomically realistic mouse phantom was 3D printed based on segmented microCT data of a tumor-bearing mouse. The phantom was modified to accommodate both laser-cut EBT3 radiochromic film within the mouse thorax and a plastic scintillator dosimeter (PSD), which may be placed within the brain, abdomen, or 1-cm flank subcutaneous tumor. Various treatments were delivered on an image-guided small-animal irradiator in order to determine the doses to isocenter using a PSD and validate lateral- and depth-dose distributions using film dosimeters. On-board cone-beam CT imaging was used to localize isocenter to the film plane or PSD active element prior to irradiation. The PSD irradiations comprised a 3×3mm2 brain arc, 5×5mm2 parallel-opposed pair (POP), and 5-beam 10×10mm2 abdominal coplanar arrangement while two-dimensional (2D) film dose distributions were acquired using a 3×3mm2 arc and both 5×5 and 10×10mm2 3-beam coplanar plans. A validated Monte Carlo (MC) model of the source was used as to verify the accuracy of the film and PSD dose measurements. computer-aided design (CAD) geometries for the mouse phantom and dosimeters were imported directly into the MC code to allow for highly accurate reproduction of the physical experiment conditions. Experimental and MC-derived film data were co-registered and film dose profiles were compared for points above 90% of the dose maximum. Point dose measurements obtained with the PSD were similarly compared for each of the candidate (brain, abdomen, and tumor) treatment sites. For each treatment configuration and anatomical target, the MC-calculated and measured doses met the proposed 5% agreement goal for dose accuracy in radiobiology experiments. The 2D film and MC dose distributions were successfully registered and mean doses for lateral profiles were found to agree to within 2.3% in all cases. Isocentric point-dose measurements taken with the PSD were similarly consistent, with a maximum percentage deviation of 3.2%. Our study confirms the utility of 3D printed phantom design in providing accurate dose estimates for a variety of preclinical treatment paradigms. As a tool for pretreatment dose verification, the phantom may be of particular interest to researchers for its ability to facilitate precise dosimetry while fostering a reduction in cost for radiobiology experiments.

Conformational Effects of [Ni2 (μ-ArS)2 ] Cores on Their Electrocatalytic Activity.

Two nickel complexes supported by tridentate NS2 ligands, [Ni2 (κ-N,S,S,S'-NPh {CH2 (MeC6 H2 R')S}2 )2 ] (1; R'=3,5-(CF3 )2 C6 H3 ) and [Ni2 (κ-N,S,S,S'-NiBu {CH2 C6 H4 S}2 )2 ] (2), were prepared as bioinspired models of the active site of [NiFe] hydrogenases. The solid-state structure of 1 reveals that the [Ni2 (μ-ArS)2 ] core is bent, with the planes of the nickel centers at a hinge angle of 81.3(5)°, whereas 2 shows a coplanar arrangement between both nickel(II) ions in the dimeric structure. Complex 1 electrocatalyzes proton reduction from CF3 COOH at -1.93 (overpotential of 1.04 V, with icat /ip ≈21.8) and -1.47 V (overpotential of 580 mV, with icat /ip ≈5.9) versus the ferrocene/ferrocenium redox couple. The electrochemical behavior of 1 relative to that of 2 may be related to the bent [Ni2 (μ-ArS)2 ] core, which allows proximity of the two Ni⋅⋅⋅Ni centers at 2.730(8) Å; thus possibly favoring H+ reduction. In contrast, the planar [Ni2 (μ-ArS)2 ] core of 2 results in a Ni⋅⋅⋅Ni distance of 3.364(4) Å and is unstable in the presence of acid.

Mathematical expression for the capacitance of coplanar strips

Knowledge of the capacitance for the coplanar arrangement of long conducting strips is relevant for transmission lines and micro-antenna design for communications and medical applications. More generally, the evaluation of capacitances for non-trivial geometries is of continuous interest in electrostatics since the dawn of the discipline. The problem of finding an exact mathematical expression for the capacitance of coplanar conducting strips has not been solved. The purpose of this article is to show the corresponding derivation and its solution. The method used here starts from the charge density at the electrodes from the solution of the electrostatic integral equation, and subsequently computes the total charge and bias voltage at each electrode, from which the expression for the capacitance follows. The main result is an exact analytical expression for the capacitance as a function of the strips width and their separation. Moreover, the capacitance is found to depend non-trivially only on a single lumped dimensionless parameter that can be written in terms of the width and the separation of the strips. To gain insight into the dependence of the capacitance on geometrical parameters, we evaluate the analytical expression and also compare it with limiting standard geometries.

Triptycene End-Capped Quinoxalinophenanthrophenazines (QPPs): Influence of Substituents and Conditions on Aggregation in the Solid State.

Triptycene end-capped quinoxalinophenanthrophenazine reveals a coplanar arrangement with a high overlap of the π planes. Four structurally related model compounds bearing electron-withdrawing or -donating groups were synthesized, and their optoelectronic properties were characterized by using cyclovoltammetry, absorption- and emission spectroscopy as well as theoretical calculations. The directional robustness of the triptycene end-capping of these compounds was tested by using single-crystal X-ray diffraction. The impact of solvents and crystallization conditions has also been investigated. In total, 17 single-crystal structures were obtained. Each structure was evaluated for its potential charge-transfer capability taking into account the overall molecular packing, solvent enclathration and the structural overlap of the π planes of adjacent molecules. For this purpose, charge-transfer integrals were also calculated for every π-stacked dimer.

Interaction of Two Micro-Propellers in Coplanar and Coaxial Arrangement for UAV Application

In the present work, we have focused on the understanding of the effect of gap between micro propellers in coplanar and in coaxial arrangements on the thrust generation experimentally. In a way it’s a preliminary optimization of the spacing and placement of the micro propellers in a multirotor UAV system. APC 12-inch diameter (D) (12X8 E) and Master air screw (MAS) 11-inch diameter (11X6) propellers each 2 in numbers were considered in the study. A static testing rig was built with a provision to mount the propellers in coplanar and in coaxial arrangements. A thrust was measured using a single component load cell. Parameters like current consumption by BLDC motors and propeller RPM were also monitored. For coplanar arrangement, there is no influence of gap (G) between the propellers on the coefficient of thrust (CT). However, for G/D<0.2 random variation in CT is observed. Similarly, for propellers in coaxial arrangement, for smaller gap between the propellers along the axis is found to generate higher thrust. This optimization of the gap between the propellers may be lead to a compact multi-rotor UAV system having higher payload carrying capacity or higher endurance.

Reactivity of 2-(Hydroxyimino)-1-pyridylbutane-1,3-diones in the Synthesis of p-Nitrosophenols

Completely substituted p-nitrosophenols were synthesized by cyclocondensation of dimethyl 3-oxopentanedioate with 2-(hydroxyimino)-1-pyridylbutane-1,3-diones. The yield of the final product depended on the position of the nitrogen atom in the pyridyl substituent and was considerably lower for the pyridin-2-yl derivative. According to the DFT B3LYP-D3/6-311G(d,p) quantum chemical calculations, the reason for the reduced reactivity of the carbonyl group linked to C2 of the pyridine ring is their nearly coplanar arrangement. Pyridin-3-yl and pyridin-4-yl substituents are located at a larger angle with respect to the carbonyl group, so that the reactivity of the latter increases.

Dicyanomethyl Radical-Based Near-Infrared Thermochromic Dyes with High Transparency in the Visible Region

In this work, we prepared novel three dicyanomethyl radicals hav-ing a triphenylamine skeleton, which show thermochromism in the near-infrared (NIR) region based on the reversible dimerization–dissociation reactions. We demonstrated that the coplanar arrange-ment of the amino group to the benzene ring bearing the dicy-anomethyl radical by O or S bridges causes the drastic batho-chromic shift of the radical absorption bands toward the NIR region. In particular, the radical with two bridging O atoms has the most red-shifted radical band of (λmax = 1059 nm compared to that of the radical with no bridging O atoms (λmax = 712 nm). Due to the significant bathochromic shift of the radical bands, these radicals have a wide optical window in the visible region. In particular, the radical with the two O bridge shows almost no perceptible color change to the naked eye and keeps high transparency over all tem-perature ranges, whereas the intensity of the NIR absorption drasti-cally changes. These radicals maintained ...

Miniaturized open-ended dual-band band-pass filter with series stepped capacitance and shunt meandered line inductance for microwave frequency applications

AbstractIn this paper, a miniaturized open-ended dual-band band-pass filter with stepped series capacitance and shunt meandered line inductance for microwave frequency applications has been designed and discussed. In order to offer ease of fabrication and uniplanar configuration, coplanar waveguide feeding arrangement has been used. Zeroth order resonance, a special phenomenon of composite right/left handed transmission line has been utilized to miniaturize the filter size. The designed filter structure offers miniaturization with overall footprint size of 0.26λg × 0.19λg, where λg is the guided wavelength at the center frequency of 1.46 GHz. It offers 58.90% (1.03–1.89 GHz) and 25.93% (2.55–3.31 GHz) measured −3 dB fractional bandwidth with respect to the center frequencies of 1.46 and 2.93 GHz, respectively. Dispersion plot has been utilized to discuss the metamaterial properties for the proposed dual-band band-pass filter. In addition to above, the proposed filter structure presents almost flat group delay curve within both passbands. The proposed filter structure can be suitably utilized for distinct wireless applications, for example global navigation satellite system (1.559–1.610 GHz), GSM1800 (1.7–1.8 GHz), Wi-MAX (2.5–2.7 GHz), and naval radar and air traffic control (2.7–2.9 GHz).

Dual-Band Eight-Element MIMO Array Using Multi-Slot Decoupling Technique for 5G Terminals

This paper presents a dual-band eight-element multiple-input multiple-output (MIMO) array using a multi-slot decoupling technique for the fifth generation (5G) mobile communication. By employing a compact dual-loop antenna element, the proposed array obtains two broad bandwidths of 12.2% and 15.4% for sub-6GHz operation. To reduce the mutual coupling between antenna elements, a novel dual-band decoupling method is proposed by employing a multi-slot structure. The proposed MIMO array achieves 15.5-dB and 19.0-dB isolations across the two operating bands. Furthermore, three decoupling modes generated by different bent slots can be independently tuned. Zero ground clearance is also realized by the coplanar arrangement of the antenna elements and decoupling structures. The proposed MIMO array was simulated, fabricated, and measured. Experimental results agree well with the simulations, showing that the dual-band MIMO array has good impedance matching, high isolation, and high efficiency. In addition, the envelope correlation coefficient and channel capacity are calculated and analyzed to validate the MIMO performance of the 5G terminal array. Such a dual-band high-isolation eight-element MIMO array with zero ground clearance is a promising candidate for 5G or future mobile applications.

Nanostructures of functionalized zinc phthalocyanines prepared with colloidal lithography: Evaluation of surface orientation and dimensions using scanning probe microscopy

Patterned arrays of nanoholes and nanorings were prepared using colloidal lithography combined with steps of solution immersion and vapor deposition of organosilanes. Samples prepared with colloidal lithography exhibit millions of reproducible test structures with a periodic arrangement throughout areas of the surface according to the dimensions and spacing of the particle mask. Views of the size and morphology of nanopatterns obtained with atomic force microscopy (AFM) can provide information of progressive steps of chemical reactions as nanostructures are grown within spatially confined areas surrounded by a resist film. A surface mask of colloidal latex or silica spheres was used to protect discrete areas of a Si(111) substrate from the deposition of organosilanes. When the mask was removed, the uncovered areas of the surface revealed regularly-shaped, small sites of uncovered substrate available for further reaction steps to build hierarchical surface structures. Nanostructures of zinc phthalocyanines (ZnPcs) were constructed using amine-terminated nanopatterns as sites for binding. Spatial selectivity was achieved for directing the attachment of ZnPcs to the surface using resist films of 2-methoxy(polyethyleneoxy)propyl]trichlorosilane (PEO-silane) and also with octadecyltrimethoxysilane (OTMS). The molecule chosen as a linker was (3-aminopropyl)triethoxysilane (APTES) which presents an amine group at the interface. In general, phthalocyanine molecules tend to bind in a coplanar orientation by physisorption to the surface and can stack together through pi-pi interactions between adjacent macrocycles. However, the nature of the substituents will also influence whether the molecules assemble on surfaces in a side-on orientation or with the macrocycle oriented in a coplanar arrangement. Hydroxyl and isothiocyanate pendant groups were attached to the macrocycles of ZnPcs chosen for this study, to investigate conformational differences when attached to APTES nanopatterns. The size and morphology of nanostructures was visualized and sensitively measured with tapping-mode AFM. The elastic response of samples patterned with ZnPc was mapped with force modulation AFM. Changes in the height of nanostructures indicate whether the macrocycles are oriented upright or parallel to the surface plane, or if multilayers were formed.

Field-Induced Dysprosium Single-Molecule Magnet Based on a Redox-Active Fused 1,10-Phenanthroline-Tetrathiafulvalene-1,10-Phenanthroline Bridging Triad.

Tetrathiafulvalene and 1,10-phenanthroline moieties present, respectively remarkable redox-active and complexation activities. In this work, we investigated the coordination reaction between the bis(1,10-phenanthro[5,6-b])tetrathiafulvalene triad (L) and the Dy(hfac)3·2H2O metallo precursor. The resulting {[Dy2(hfac)6(L)]·CH2Cl2·C6H14}3 (1) dinuclear complex showed a crystal structure in which the triad L bridged two terminal Dy(hfac)3 units and the supramolecular co-planar arrangement of the triads is driven by donor-acceptor interactions. The frequency dependence of the out-of-phase component of the magnetic susceptibility highlights three distinct maxima under a 2000 Oe static applied magnetic field, a sign that 1 displays a Single-Molecule Magnet (SMM) behavior with multiple magnetic relaxations. Ab initio calculations rationalized the Ising character of the magnetic anisotropy of the DyIII ions and showed that the main anisotropy axes are perpendicular to the co-planar arrangement of the triads. Single-crystal rotating magnetometry confirms the orientation of the main magnetic axis. Finally combining structural analysis and probability of magnetic relaxation pathways through Quantum Tunneling of the Magnetization (QTM) vs. excited states (Orbach), each DyIII center has been attributed to one of the three observed magnetic relaxation times. Such coordination compound can be considered as an ideal candidate to perform redox-magnetic switching.

A Straightforward Synthesis to Novel 1,10-Phenanthrolines with Fused Thiophene Structure

We report here a straightforward synthesis for a series of new structures with fused 1,10-phenanthroline-thiophene connection. They are synthesized with a modified Hinsberg thiophene procedure, followed by successive modification to yield several 5,7-disubstituted thieno[3,4-f][1,10]phenanthrolines, most notable thiophene-substituted compounds that could be potentially of use for organic electronics ­applications. For some selected examples, crystal structures were ­obtained, showing a nearly coplanar arrangement around the fused connection, also beneficial for an effective electron transfer in organic electronics or solar cells.

Benzofuran-/Benzothiophene-Incorporated NIR-Absorbing Triphyrins(2.1.1).

Novel benzofuran-/benzothiophene-incorporated triphyrins(2.1.1) were synthesized using readily available precursors under mild reaction conditions. The X-ray structure revealed that the benzofuran-incorporated triphyrin(2.1.1) macrocycle was slightly ruffled. The triphyrins(2.1.1) exhibit more absorption in the NIR region compared to previously reported dibenzofuran-/dibenzothiophene-incorporated hybrid macrocycles. The benzofuran-incorporated triphyrin shows significant red shift in absorption bands compared to that of benzothiophene-based triphyrin due to its more coplanar arrangement as supported by X-ray and DFT studies.

An evaluation of systematic errors on marker-based registration of computed tomography and magnetic resonance images of the liver.

We demonstrated a general method to evaluate systematic errors related to Magnetic Resonance (MR) imaging sequences in marker-based co-registration of MR and Computed Tomography (CT) images, and investigated the effect of MR image quality in the co-registration process using clinical MR and CT protocols for stereotactic ablative body radiotherapy (SABR) planning of the liver. Small systematic errors (under 1.6 mm) were detected, unlikely to be a clinical risk to liver SABR. The least favourable marker configuration was found to be a co-planar arrangement parallel to the transaxial image plane.

Mineralization of flexible mesoporous TiO2 photoanodes using two low‐temperature dielectric barrier discharges in ambient air

Two types of dielectric barrier discharges (DBDs), volume DBD (called Industrial Corona) and coplanar DBD, were used for low temperature (70 °C) atmospheric pressure plasma mineralization of mesoporous methyl‐silica/titanium dioxide nanocomposite photoanodes. The photoanodes with a thickness of approx. 300 nm were inkjet‐printed on flexible polyethylene terephthalate (PET) foils. Plasma treatments of both DBDs led to changes in the chemical stoichiometry and morphology of the mesoporous photoanodes, resulting in a significant increase of the work function from approx. 4.0 to 4.3 eV and 4.8 eV, after plasma mineralization with volume DBD and coplanar DBD, respectively. We also studied the effect of plasma mineralization on the photoelectrochemical properties of the flexible mesoporous TiO2 photoanodes. Plasma mineralization with volume DBD and coplanar DBD showed different effects on the generated photocurrent in the photoanodes. Although the plasma mineralization with volume DBD showed only a minor effect on the photocurrent, plasma mineralization with coplanar DBD led to significantly higher photocurrents. We found that the enhancement of the photoelectrochemical properties was related to the homogeneity of the plasma‐treated surfaces—arising from different spatial properties of the plasma between volume and coplanar DBDs. Furthermore, the results showed that plasma mineralization using coplanar DBD can effectively change the energy levels of the surface. This resulted in the enhancement of the work function and the photoelectrochemical properties of the mesoporous TiO2 photoanodes. This contribution shows that coplanar arrangement of electrodes in DBDs generates plasma of higher efficacy compared with standard volume DBD that is currently often used in industrial processes.

Cu(II)–N6-Alkyladenine Complexes: Synthesis, X-ray Characterization and Magnetic Properties

Three new dinuclear copper(II) complexes [Cu2(μ–HLn)2(μ-Cl)2Cl2]Cl2 (1–3) have been synthesized and structurally characterized by single-crystal X-ray diffraction, where HLx, (HL1 = N6-propyladeninium, HL2 = N6-butyladeninium and HL3 = N6-isobutyladeninium) are N6-alkyl bidentate NN donor adenine bases. Complexes 1–3 exhibit a coplanar arrangement of both N6-alkyladeninium moieties with UD conformation, with the terms U(up) or D(down) referring to the coordination of each pyrimidinic N3 atoms to the upper or lower metal center. In the three complexes, both copper atoms are five-coordinated (N2Cl3 donor set), resembling a compressed trigonal bipyramid. Each adenine moiety is protonated in N1 and the positive charge balanced by chloride counterions. Magnetic measurements of complexes 1 and 3 in the 2–300 K temperature range indicate antiferromagnetic coupling with J = −156.1(7) and J = −151(2) cm−1, respectively. Density functional theory calculations have also been performed in order to estimate the exchange coupling constants in these complexes. The theoretically calculated J values are in good agreement with the experimental values.

Activation of polycarbonate (PC) surfaces by atmospheric pressure plasma in ambient air

This paper presents the study of the ambient air atmospheric pressure plasma (APP) treatment of polycarbonate (PC) surfaces to improve the wettability. The APP was generated by dielectric barrier discharge of coplanar electrode arrangement: a Diffuse Coplanar Surface Barrier Discharge (DCSBD), and gliding arc APC 500. The changes in wettability of the PC surfaces were characterized by water contact angle measurement, hysteresis analysis of the water contact angle and surface free energy. We found that both plasma sources led to considerable decrease of water contact angle in first second of the treatments. Surface free energy analysis explained, that the decrease of the water contact angle was related to higher polar components of the surface. The modification of the PC surfaces was further evaluated by X-ray photoelectron spectroscopy that showed that both plasma sources led to increase in concentration of polar functional groups on the PC surface. The main difference between DCSBD and APC plasmas was in the surface morphology which observed by atomic force microscopy (AFM).