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We show that the variety of permutative posemigroups is epimorphically closed and all subvarieties of the variety V of permutative posemigroups admitting a permutation identity x 1 x 2 ⋯ x n = x i 1 x i 2 ⋯ x i n with i n ≠ n and i 2 ≠ 2 [ i 1 ≠ 1 and i n − 1 ≠ n − 1 ] are epimorhically closed. Further, we find certain epimorphically closed subvarieties of the variety V of permutative posemigroups with i n ≠ n [ i 1 ≠ 1 ]. Finally we show that, under certain conditions, an identity is preserved under posemigroup epis in conjunction with any permutation identity. [ABSTRACT FROM AUTHOR]

Copyright of Categories & General Algebraic Structures with Applications is the property of Shahid Beheshti University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Zigzag ZnS thin films prepared by thermal evaporation method using glancing angle deposition (GLAD) technique. ZnS films with zigzag structure were produced at deposition angles of 0˚, 60˚ and 80˚ at room temperature on glass substrates. Surface morphology of the films w::as char::acterized by using field emission scanning electron microscopy (FESEM). The optical properties of the specimens were investigated by using UV-Vis spectroscopy technique. To characterize the porosity of the simulated structures, the PoreSTAT software which analyses the NASCAM software was employed. The optical transmissions of the samples were calculated by using NASCAM optics package. The simulation results are completely in agreement with the experimental results.

Graphene has been widely and extensively used in mass sensing applications. The present study focused on exploring the use of single-layer graphene (SLG) and double-layer graphene (DLG) as sensing devices. The dynamic analysis of SLG and DLG with different boundary conditions (BDs) and length was executed using the atomistic finite element method (AFEM). SLG and DLG sheets were modelled and considered as a space–frame structure similar to a 3D beam. Spring elements (Combin14) were used to identify the interlayer interactions between two graphene layers in the DLG sheet due to the van der Waals forces. Simulations were carried out to visualize the behavior of the SLG and DLG subjected to different BDs and when used as mass sensing devices. The variation in frequency was noted by changing the length and applied mass of the SLGs and DLGs. The quantity of the frequency was found to be highest in the armchair SLG (6, 6) for a 50 nm sheet length and lowest in the chiral SLG (16, 4) for a 20 nm sheet length in the bridged condition. When the mass was 0.1 Zg, the frequency for the zigzag SLG (20, 0) was higher in both cases. The results show that the length of the sheet and the various mass values have a significant impact on the dynamic properties. The present research will contribute to the ultra-high frequency nano-resonance applications.

We show that the posemigroup dominion of a commutative posemigroup is again a commutative posemigroup and all varieties of commutative posemigroups are epimorphically closed. Next, we show that certain subvarieties of the variety of all commutative posemigroups are saturated. Finally, we show that a commutative posemigroup S is saturated if S k is saturated for some positive integer k. [ABSTRACT FROM AUTHOR]

Understanding the long-term stability of MoS2 is important for various optoelectronic applications. Herein, we show that the long-term exposure to an oxygen atmosphere for up to a few months results in zigzag (zz)-directional line unzipping of the MoS2 basal plane. In contrast to exposure to dry or humid N2 atmospheres, dry O2 treatment promotes the initial formation of line defects, mainly along the armchair (ac) direction, and humid O2 treatment further promotes ac line unzipping near edges. Further incubation of MoS2 for a few months in an O2 atmosphere results in massive zz-directional line unzipping. The photoluminescence and the strain-doping plot based on two prominent bands in the Raman spectrum show that, in contrast to dry-N2-treated MoS2, the O2-treated MoS2 primarily exhibits hole doping, whereas humid-O2-treated MoS2 mainly exists in a neutral charge state with tension. This study provides a guideline for MoS2 preservation and a further method for generating controlled defects.

Summary: Energy is a global demand nowadays. Researchers and Scientists are trying every day to find new resources to generate energy. Mechanical energy is considered one of the most essential energy resources in the world. It can be easily generated and transferred into electrical energy. There are a lot of new technologies that are working to develop small and portable energy harvesters for electronic devices such as piezoelectric and triboelectric nanogenerators (TENGs). However, TENGs are more favorable to piezoelectric nanogenerators due to the availability of nontoxic materials. Moreover, they are cheap and exhibit high performance. This article investigates one of the TENG devices, Zigzag structure. It presents an analytical derivation for the model that addresses all aspects of the TENG such as the output voltage, the output current, the capacitance, the resistive load, the capacitive load and the harvested power step by step. The analytical derivation is also verified using COMSOL simulations to validate the results. The mismatch between the analytical derivation and COMSOL is 0.022% in the open circuit voltage and 0.33% in short circuit charge. Electrical behavior is presented afterwards using Verilog‐A in Cadence to examine the performance of the TENG devices in real life situations. For the chosen parameters, the device delivers a maximum voltage of 23 KV at nearly 90° and a maximum current of 7.5 μA at nearly 10°. The maximum reported output power for a load of 5 GΩ is 5.2 mW. [ABSTRACT FROM AUTHOR]

This contribution presents, for the first time, the design of microwave lowpass filter with ultrawide stopband and low insertion loss based on the log-periodic zig-zag defected ground structure (DGS); the design is specifically evolved from the principle of the log-periodic line antenna and the slotline based DGS. Based on the log-periodic property, studies show that ultra-wideband suppression can be realized by increasing the flare angle or the angle subtended by each element of the slotline DGS. The developed filter therefore shows low insertion loss of 0.7 dB within the passband, sharp transition between the passband and the stopband and ultra-wide suppression band from 2.61-26.5 GHz with a 20 dB suppression level. The DGS architecture is simple and easy to realize, and the design is thus useful in many microwave applications. The fabricated prototype filter validates the study, both from simulations and from measurements. [ABSTRACT FROM AUTHOR]

The purpose of this work was to conduct a numerical examination of mixed convective heat transfer in a three-dimensional triangular enclosure with a revolving circular cylinder in the cavity’s center. Numerical simulations of the hybrid Fe3O4/MWCNT-water nanofluid are performed using the finite element approach (FEM). The simulation is carried out for a range of parameter values, including the Darcy number (between 10−5 and 10−2), the Hartmann number (between 0 and 100), the angular speed of the rotation (between −500 and 1000), and the number of zigzags. The stream function, isotherms, and isentropic contours illustrate the impact of many parameters on motion, heat transfer, and entropy formation. The findings indicate that for enhancing the heat transfer rates of hybrid nanofluid in a three-dimensional triangular porous cavity fitted with a rotating cylinder and subjected to a magnetic field, Darcy number > 10−3, Hartmann number < 0, one zigzag on the hot surface, and rotation speed >500 in flow direction are recommended.

Tinea capitis (TC) is the most prevalent pediatric superficial dermatophyte infection. The culprit species differ across the continents; for instance, Microsporum canis prevails in Europe, whereas Trichophyton tonsurans dominates in North America. Oral medication is always* the main required remedy as TC does not respond well to topical therapy unaided. However, in some countries, griseofulvin is no longer available. Fungal culture should be included in the study of persistent, scalp lesions and trichoscopy can offer a speedy diagnosis by its characteristic findings. Scalp dermoscopy or “trichoscopy” represents a valuable, noninvasive technique for the evaluation of patients with hair loss due to TC. It is simple, quick, and easy to perform.

Copyright of Al Malweah for Archaeological & Historical Studies is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Five isostructural tetranuclear lanthanide complexes with the general formula [Ln4(teaH2)2(teaH)2(NO3)6]·2CH3OH [Ln3+ = Dy3+ (1), Tb3+ (2), Ho3+ (3), Er3+ (4), and Gd3+ (5)] were successfully synthesized by the reaction of various lanthanide nitrate and triethanolamine (teaH3) ligand. Single crystal X‐ray analyses reveal the eight‐coordinate Ln3+ centers adopt a slightly distorted triangular dodecahedron geometry and nine‐coordinate Ln3+ ions own an approximately capped square antiprism environment in similar zigzag Ln4 core. Magnetic studies demonstrate the presence of anitferromagnetic interactions between Ln3+ centers without obvious SMM behavior. [ABSTRACT FROM AUTHOR]

A novel one-dimensional zigzag chain-like CoII coordination polymer constructed from 4,4' -bipyridine (4,4' -bpy) and 2-hydroxybenzoate (2-OHbenz) ligands, namely, catena-poly[[(4,4'-bipyridine-KN)(μ-2-hydroxybenzoato- K² O:O0 )(k²-hydroxybenzoato-K² O,O' )cobalt(II)]μ--4,4' -bipyridine-K² N:N'-[aquahemi(-4,4' -bipyridine-2 N:N' )(2-hydroxybenzoato-O(2-hydroxybenzoato-K ² O:O' )cobalt(II)], [Co2(C7H5O3)4(C10H8N2)2.5(H2O)]n, has been synthesized by reacting cobalt(II) nitrate trihydrate, 4,4' -bpy and 2-hydroxybenzoic acid in a mixture of water and methanol at room temperature. There are two independent CoII centers, Co1 and Co2, in the asymmetric unit, revealing a distorted octahedral geometry with chromophore types of [CoN2O4] and [CoN2O3O0 ], respectively. The Co1 ions are doubly bridged by 2-OHbenz ligands with syn–anti coordination mode, generating a dinuclear unit. The bridging 4,4'-bpy ligands connect these dinuclear units and the mononuclear Co2 chromophores, providing a one-dimensional alternating zigzag chain-like structure. In the crystal, intermolecular hydrogen bonds, C—H. . .πand π–π stacking interactions are observed and these help to consolidate the packing. In addition, the physical properties of the title compound are reported [ABSTRACT FROM AUTHOR]

Mouse dorsal coat hair types, guard, awl, auchene and zigzag, develop in three consecutive waves. To date, it is unclear if these hair types are determined genetically through expression of specific factors or can change based on their mesenchymal environment. We undertook a novel approach to this question by studying individual hair type in 67 Collaborative Cross (CC) mouse lines and found significant variation in the proportion of each type between strains. Variation in the proportion of zigzag, awl and auchene, but not guard hair, was largely due to germline genetic variation. We utilised this variation to map a quantitative trait locus (QTL) on chromosome 12 that appears to influence a decision point switch controlling the propensity for either second (awl and auchene) or third wave (zigzag) hairs to develop. This locus contains two strong candidates, Sostdc1 and Twist1, each of which carry several ENCODE regulatory variants, specific to the causal allele, that can influence gene expression, are expressed in the developing hair follicle, and have been previously reported to be involved in regulating human and murine hair behaviour, but not hair subtype determination. Both of these genes are likely to play a part in hair type determination via regulation of BMP and/or WNT signalling. [ABSTRACT FROM AUTHOR]

Equivalent single layer theories for layered beams effectively and accurately predict global displacements and internal force and moment resultants using a limited number of displacement variables. However, they cannot reproduce local effects due to material architecture or weak/imperfect bonding of the layers, such as zigzag displacement fields, displacement jumps at the layer interfaces and complex transverse stress fields, nor can they simulate delamination damage growth. In this work we will present some applications and discuss advantages and limitations of a recently formulated zigzag model. The model, through a modification of the equilibrium equations of an equivalent single layer theory, which maintains the same number of variables, reproduces local effects and delamination fracture under mode II dominant conditions. The approach is based on a local enrichment of the displacement field of first order shear deformation theory, the introduction of cohesive interfaces and homogenization. [ABSTRACT FROM AUTHOR]

Efficient heat transfer in modern microelectronic devices plays an essential part in improving the devices functionality and lifetime. Microchannel heat sinks offer excellent heat transfer properties, and have widespread applications in highly integrated electronic devices. The flow and heat transfer properties of single crystal diamond zigzag double-layer microchannel heat sinks (DL-MCHSs) were investigated by numerical simulation. The mechanism of enhanced heat transfer in zigzag DL-MCHSs was analyzed by the velocity, temperature and pressure fields, and the geometric parameters of the single crystal diamond DL-MCHSs were evaluated and optimized by means of performance evaluation criteria. The results illustrate that the zigzag channel not only increases the convective area, but also enhances the fluid disturbance leading to higher degree of fluid blending, which greatly enhance the heat transfer of the single crystal diamond DL-MCHSs. Upper zigzag and lower zigzag single crystal diamond DL-MCHSs can offer the highest performance evaluation criteria among the four structures. When Re = 700, the relative height of zigzag (α), the number of zigzag cycles (β), and the height ratio of upper to lower channels (γ) are 0.5, 45, and 1.2, respectively, the optimized upper zigzag and lower single crystal diamond zigzag DL-MCHSs achieve the 38 % enhancement in comprehensive performance. This work contributes to the corresponding scientific instruction for the management and implementation of the single crystal diamond DL-MCHSs. • The heat transfer mechanism of DL-MCHSs were investigated using temperature, velocity, and pressure fields. • Upper zigzag and lower zigzag sDL-MCHSs can offer the highest comprehensive performance. • The effects of α, β and γ on their thermal and hydraulic characteristics were investigated. [ABSTRACT FROM AUTHOR]

In the present study, the motion and interaction of a bubble pair rising in a stationary liquid are simulated in two dimensions using the volume of fluid method (VOF) in the open-source CFD package OpenFOAM. For validation, the single bubble rising for different regimes was simulated. Comparing the present study results and previous numerical and experimental results showed that the results have a good agreement. In the present study, the bubble pair is arranged along a horizontal line, and results showed that in 2D domain four different interactions happen between the bubble pair rising based on the Bond (Bo) and Morton (Mo) numbers which are: coalescence, bouncing, zigzagging, and breakup. The simulations are done at three different slopes of the line connecting the center of two bubbles (θ =[ 0 ° , 45 ° , and 90 ° ]), which shows the different arrangements of bubble pairs. At θ = 90 ° , due to the attraction created by the wake of the leading bubble, the trailing bubble gets a significant acceleration in its motion, and will coalesce in the absence of surfactants. The results showed that the value of the trailing bubble velocity increases with decreasing the separation distance between the bubbles. Also, the rising velocity of the trailing bubble is always greater than the velocity of a single bubble due to the attraction effect of the leading bubble's wake. The drag force of a trailing bubble decreases with decreasing the separation distance between the bubbles. Finally, a general criterion based on dimensionless numbers of Bo and Mo is presented to determine the type of interaction between bubble pair. [ABSTRACT FROM AUTHOR]

We developed a 17.3" FHD 360HZ high‐end electronic competitive LCD in IGZO. For reducing the risk of pixel capacitance undercharge, we designed zigzag pixel structure and used pre‐charge driving mode. In addition, this product uses fast response liquid crystal and dynamic OD technology to reduce response time. Moreover, the downward backlit Local Dimming partition control is designed to meet HDR specifications. [ABSTRACT FROM AUTHOR]

Objective: Wound healing problems after neurosurgical procedures can lead to serious complications and may require complex revision or even reconstructive surgery. Therefore, optimal surgical management is critical to prevent complications. In a recent experimental study in animals, the authors demonstrated the superiority of a zigzag skin incision over a straight incision pattern. In this study, the authors applied these findings to clinical situations of neurosurgical patients with an indication for a coronal skin incision. The aim of this study was to objectively assess the functional and cosmetic outcomes between straight coronal and zigzag incisions in neurosurgical procedures., Methods: This prospective, randomized, controlled, single-center trial included adult patients undergoing frontal craniotomy for cerebrovascular or tumor pathologies. The study primarily included patients who were not expected to receive adjuvant radiation or chemotherapy. The zigzag incision was standardized using a template. A common straight skin incision behind the hairline served as a control. Complication rates, functional (2-point discrimination, width of the wound, Vancouver Scar Scale [VSS], and Patient and Observer Scar Assessment Scale [POSAS]), and cosmetic outcomes were assessed postoperatively and at 3-month follow-up evaluations. Additionally, all patients answered a wound-specific questionnaire and the SF-36 questionnaire., Results: Twenty-eight patients were randomized to the zigzag and 29 to the straight incision groups. Indications for surgery were cerebrovascular in 16 cases and tumors in 41 cases. Risk factors for wound healing were equally distributed in both groups. One patient in the zigzag group with poor postoperative compliance required surgery for secondary wound healing problems. Overall, the width of the scar was significantly smaller (p = 0.001) and local 2-point discrimination better (p = 0.005) in the zigzag group. Scores on the VSS (p = 0.003) and POSAS (p = 0.005) proved to be significantly superior in the zigzag group as well., Conclusions: A zigzag coronal skin incision pattern leads to significantly superior functional and cosmetic outcome scores. For certain patient groups, these findings may prove to be practice-changing.

A bottom up method for the synthesis of unique tetracene‐based nanoribbons, which incorporate cyclobutadiene moieties as linkers between the acene segments, is reported. These structures were achieved through the formal [2+2] cycloaddition reaction of ortho‐functionalized tetracene precursor monomers. The formation mechanism and the electronic and magnetic properties of these nanoribbons were comprehensively studied by means of a multitechnique approach. Ultra‐high vacuum scanning tunneling microscopy showed the occurrence of metal‐coordinated nanostructures at room temperature and their evolution into nanoribbons through formal [2+2] cycloaddition at 475 K. Frequency‐shift non‐contact atomic force microscopy images clearly proved the presence of bridging cyclobutadiene moieties upon covalent coupling of activated tetracene molecules. Insight into the electronic and vibrational properties of the so‐formed ribbons was obtained by scanning tunneling microscopy, Raman spectroscopy, and theoretical calculations. Magnetic properties were addressed from a computational point of view, allowing us to propose promising candidates to magnetic acene‐based ribbons incorporating four‐membered rings. The reported findings will increase the understanding and availability of new graphene‐based nanoribbons with high potential in future spintronics. [ABSTRACT FROM AUTHOR]

Peculiar zigzag-like Prussian blue analogue was created by anisotropic etching of PBA arising from inhomogeneous spatial distribution of FeIII during ions doping. • Zigzag-like Prussian blue analogue was created by anisotropic etching of PBA. • It arose from inhomogeneous spatial distribution of FeIII by ions doping. • The open "Z" structure endowed the catalyst with promising catalytic efficiency. Nanoscale metal–organic frameworks (nano-MOFs) with unique open architectures offer great advantages for constructing fascinating functional materials, but their configurations are largely limited to mesoporous or hollow structures. Both the rational design of nano-MOFs with sophisticated structures and the comprehensive knowledge of their formation mechanism remain an interesting research topic. In this work, we reported a highly peculiar zigzag crystal of a Prussian blue analogue (PBA) bearing the ensemble of walls with uniform thickness (∼60 nm) in three-dimensional space. Such "Z"-like PBA was acquired by the preferential etching of two opposing corners of its parent NiCo-PBA cubes that was pre-doped by metal ligand ions (i.e. , [Fe(CN) 6 ]3−). Mechanistic studies suggested that the anisotropic etching seemed to arise from the heterogeneous growth and inhomogeneous spatial distribution of the FeIII and FeII (stemming from redox reaction of FeIII) species, even though all the metal elements (including Fe, Co, and Ni) were evenly dispersed in each individual cube as indicated by HAADF-STEM and linear EDS scan analyses. The open "Z" structure provided larger surface area and a greater number of active sites to activate reagents in catalytic reaction and enhanced the degradation efficiency in removing bisphenol A from aqueous solution with PMS. The current findings are expected to pave way for a fine tuning the structures and properties of MOFs, and encourage extended research on developing novel anisotropic crystals. [ABSTRACT FROM AUTHOR]

Let Γ be a triangulation of a connected closed 2-dimensional (not necessarily orientable) surface. Using zigzags (closed left–right walks), for every face of Γ we define the z -monodromy which acts on the oriented edges of this face. There are precisely 7 types of z -monodromies. We consider the following two cases: (M1) the z -monodromy is identity, (M2) the z -monodromy is the consecutive passing of the oriented edges. Our main result is the following: the subgraphs of the dual graph Γ ∗ formed by edges whose z -monodromies are of types (M1) and (M2), respectively, both are forests. We apply this statement to the connected sum of z -knotted triangulations. [ABSTRACT FROM AUTHOR]

Zigzag ZnS thin films prepared by the thermal evaporation method using glancing angle deposition (GLAD) technique. ZnS films with the zigzag structure were produced at deposition angles of 0°, 70° and 80° at room temperature on glass substrates. Surface morphology of the films was characterized by using field emission scanning electron microscopy (FESEM). The optical properties of the specimens were investigated by using UVVis spectroscopy technique. To characterize the porosity of the simulated structures, the PoreSTAT software which analyses the NASCAM software was employed. The optical transmissions of the samples were calculated by using NASCAM optics package. The simulation results are completely in agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Abstract The subject of the paper is modelling of complex damage behaviour of laminated glass, which is a sandwiched polymer composite. Last 20 years have witnessed extensive growth in computational modelling of complex nonlinear behaviour of laminated glass panels with viscoelastic interlayers. Present review article is an attempt to highlight applications of finite element approach in failure analysis of laminated glasses. Evolution of modelling theories such as equivalent single layer theories, layerwise theories and zig-zag models have been presented to insight the fundamental concepts used in modelling. Finite element techniques such as erosion, cohesive zone and extended finite element methods available in FE packages are briefly reviewed alongwith material models for glass and interlayer. The systematic growth in FE models in numerical simulation of human head impact on windshields and blast loading is specifically presented. Finite element models have been proposed as useful guides to engineers for fabrication of laminated glasses with more realistic data to be used in real world situations without going for expensive and time consuming experimental set ups. Overall 223 research articles have been included exhibiting the research performed in context of laminated glass. Highlights • Systematic growth in modelling of laminated glass is briefly summarized. • Evolution of equivalent single layer theories, layerwise theories and zig-zag models is reviewed. • Fundamentals of FE modelling are presented. • Methodical growth in FE models for human head impact on windshield and blast loading is outlined. [ABSTRACT FROM AUTHOR]

The organization and dynamics of chromatin fiber play crucial roles in regulating DNA accessibility for gene expression. Here we combine cryoelectron tomography (cryo-ET), sub-volume averaging, and 3D segmentation to visualize the in vitro and in vivo chromatin fibers folding by linker histone. We discover that an increased nucleosome repeat length and prolonged fiber length do not change the two-start helical architecture in reconstituted chromatin of homogeneous composition. Additionally, an isolated chromatin fiber with heterogeneous composition was observed, which includes short-range regions compatible with two-start helix. In vivo , sub-volume averaging reveals similar subunits of two-start helical architecture in transcriptionally inactive chromatin in frog erythrocyte nuclei. Strikingly, unambiguous DNA trajectories that displayed a zigzag pattern universally between alternate N/N+2 nucleosomes were further determined by cryo-ET with voltage phase plate. Therefore, these structural similarities suggest a general folding mode of chromatin induced by linker histone, and heterogeneous compositions mainly affect local conformation rather than changing the overall architecture. [Display omitted] • Chromatin fiber both in vitro and in vivo shows a general folding mode of two-start zigzag • Unambiguous DNA trajectories indicate a universal zigzag pattern • The heterogeneity of nucleosomes mainly affects local conformation of chromatin Li et al. reveal a universal two-start zigzag architecture and a general folding mode of chromatin fiber, in which the DNA trajectories display an unambiguous zigzag pattern both in vitro and in vivo. [ABSTRACT FROM AUTHOR]