Side Of Plane Research Articles

Relationships between selected parameters of pelvis in children and adolescents aged 3–20 years of age in the context of gender and environment

Introduction: Pelvis is a part of the skeletal system. It is a pelvic ring composed of the sacral bone, coccygeal bone and two pelvic bones, the right one and the left one. When walking, pelvis undergoes angular displacement in the frontal, sagittal and transverse planes. 
 Material and methods: The studies were conducted in randomly selected kindergartens and schools from the urban and rural environment in the Warmia and Masuria region and the Pomerania region among 1832 male and 1974 female subjects at the age of 3 – 20 years. The photogrammetric method was applied to diagnose the angle of pelvic torsion to the left and to the right side in the frontal plane. 
 Results: The general analysis of the correlation coefficient including positive and negative correlations suggested that the values ranged between 0.43 and 0.44 for KNM and KNM-, from -0.1 to 0.1 for KNM and KSM-, and from -0.08 to -0.04 for KNM and KSM. Spearman’s rank correlation coefficient for KNM- and KSM- ranged between -0.11 and -0.1, for KNM and KSM from -0.14 to 0.11, and for KSM- and KSM -0.72 to -0.7. 
 Conclusions: A high degree of negative correlations was recorded between the angle of pelvic torsion in the transverse plane to the left and the angle of pelvis twisted to the right side. A poor degree of positive correlation was observed between the parameters of KNM and KSM- as well as KNM- and KSM. A poor negative correlation was reported between the parameters of KNM and KSM and the parameters of KNM- and KSM-. The correction procedure for the pelvic position should consider mutual interdependencies of tilt angles in the frontal plane and of torsion angles in the transverse plane.

Is location of urethral kinking a confounder of association between urethral closure pressure and stress urinary incontinence?

Intact urethral support and normal sphincter function are deemed important for urinary continence. We aimed to test whether the location of urethral kinking (as the probable anatomical correlate of maximal pressure transmission) is associated with stress urinary incontinence and/or urodynamic stress incontinence. This was a retrospective study of women seen at a tertiary urogynecological center in 2017. Patients had undergone an interview, multichannel urodynamic testing and four-dimensional translabial ultrasound examination. Those with a history of anti-incontinence surgery, absence of urethral kinking on ultrasound and/or missing or inadequate ultrasound volume data were excluded. Volume data were used to assess urethral mobility using a semi-automated Excel® urethral motion profile program. Mobility vectors were calculated using the formula √((x valsalva - x rest )2 + (y valsalva - y rest )2 ), where x and y are the coordinates of six equidistant points along the length of the urethra from the bladder neck to the external urethral meatus. The location of urethral kinking was identified as a concave contour of the urethra on the vaginal side in the midsagittal plane on maximum Valsalva maneuver. The distance between the center of the kink and the bladder neck was measured and expressed as a centile in relation to the total length of the urethra, using the formula: (distance from bladder neck/total length of urethra) × 100. Univariate and multivariate analyses were performed to test the associations of stress urinary incontinence and urodynamic stress incontinence with age, maximum urethral pressure, urethral mobility vectors and location of urethral kinking. Of 450 women seen during the study period, 61 were excluded owing to previous incontinence surgery and 82 owing to absence of urethral kinking, inadequate volume data or missing data, leaving 307 women included, of whom 227 (74%) complained of stress urinary incontinence and 211 (69%) complained of urgency urinary incontinence. 190 (62%) of the women were diagnosed with urodynamic stress incontinence. On multivariate analysis, maximum urethral pressure (36 vs 50 cmH2 O; P < 0.001), mid-urethral mobility (2.27 vs 2.03 cm; P = 0.003) and location of urethral kinking (63.1st vs 59.7th centile; P = 0.002) were associated significantly with urodynamic stress incontinence. The location of urethral kinking was associated with stress urinary incontinence on univariate analysis (P = 0.026) but not on multivariate analysis (P = 0.21). The location of urethral kinking is associated with urodynamic stress incontinence. The further urethral kinking is from the mid urethra, the more likely is urodynamic stress incontinence. This provides circumstantial evidence for the pressure-transmission theory of stress urinary continence. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Multicolor luminescence of hexagonal NaYF4:Yb3+/Ho3+/Ce3+ microcrystals with tunable morphology under 940 nm excitation for temperature-responsive anti-counterfeiting

In this study, the hexagonal NaYF4:Yb3+/Ho3+/Ce3+ microcrystals were synthesized controllably, and upconversion luminescence excited at 940 nm and its application in temperature-responsive anti-counterfeiting are reported. It is clarified that the Ln3+ (Ln = Y + Yb + Ho + Ce) density ratio of bottom plane to side plane in the unit cell can be regulated by Ce3+ doping. It is also proved that the energy transfer of Yb3+ to Ho3+ is responsible for the activation of Ho3+ under 940 nm excitation, while the cross relaxation between Ho3+ and Ce3+ participates in the redistribution of electron population of 5S2/5F4 and 5F5 levels. Both theory and experiment confirm that the intensity ratio of red to green emission (IR/IG) as a function of temperature as an independent variable has good linear characteristics in the temperature range of 300–500 K. Due to the good responsiveness of multicolor luminescence to temperature, the hexagonal NaYF4:Yb3+/Ho3+/Ce3+ with tunable morphology is a promising candidate for advanced temperature-responsive upconversion anti-counterfeiting. Our results provide a new pathway for the controllable synthesis of hexagonal NaYF4 microcrystals as well as the regulation of upconversion luminescence that is excited by wavelengths other than 980 nm and its application in anti-counterfeiting.

First-principles calculation identification of ultrahigh hydrogen storage capacity in g-Mg3N2

Due to intrinsically existing uniform periodic vacancies (hollow) and light metal ions (Mg2+), the two-dimensional (2D) g-Mg3N2 is identified as a promising candidate material for hydrogen storage from first principles calculations. The hydrogen storage mechanism is carefully analyzed through the electronic structure change of the g-Mg3N2 substrate before and after hydrogen molecule absorption. Ultrahigh hydrogen storage gravimetric density and surface area of 15.2% and 7.9 * 10−8 kg/m2 is predicted for the g-Mg3N2, without additional alkali metal decorations. The appropriate sequential adsorption energy ranging from − 0.139 to − 0.078 eV and the average adsorption energy of −0.103 eV/H2 ensures hydrogen storage has very good reversibility. Ab initio molecular dynamics simulations show that a large percentage of the hydrogen molecules can be released from the g-Mg3N2 host at elevated temperatures, indicating that the efficiency of hydrogen storage and release can be very high. Meanwhile, the g-Mg3N2 lattice is very stable upon hydrogen adsorption, showing very good cycling performance in practical applications. Benefit from the large holes in the structure of g-Mg3N2, hydrogen molecules can move easily from one side of the g-Mg3N2 plane to the other through the holes (with only 96 meV barrier height), which is also beneficial to increase the hydrogen storage efficiency.

Technical drawing

The objective of this work is to propose the use of didactic material, to facilitate the teaching and learning of orthogonal projections in the international system. Virtual files of the projection planes are created: front, left side and bottom; as well as those corresponding to three versions of the same geometric entity: point, line, area and solid. The frontal plane is fixed, and the left side and bottom are restricted with respect to it allowing its rotation to coplanar all three. In the assembly of the projection planes, versions 1, 2 and 3 of the same geometric entity are inserted; each one respectively including its frontal, right lateral and superior projections; such versions are restricted with respect to the frontal, left side and bottom plane. The restrictions between the projection planes and between them and the versions of the same geometric entity allow the animation of the assembly, showing the solution of the problem that involves representing a three-dimensional object on a sheet. The augmented, virtual, animated, and timed reality environment; according to the learning needs of students and teaching of teachers; constitutes the main contribution of this work.

Origin of the Surprising Mechanical Stability of Kinesin's Neck Coiled Coil.

Kinesin-1 is a motor protein moving along a microtubule with its two identical motor heads dimerized by two neck linkers and a coiled-coil stalk. When both motor heads bind the microtubule, an internal strain is built up between the two heads, which is indispensable to ensure proper coordination of the two motor heads during kinesin-1's mechanochemical cycle. The internal strain forms a tensile force along the neck linker that tends to unwind the neck coiled coil (NCC). Experiments showed that the kinesin-1's NCC has a high antiunwinding ability compared with conventional coiled coils, which was mainly attributed to the enhanced hydrophobic pressure arising from the unconventional sequence of kinesin-1's NCC. However, hydrophobic pressure cannot provide the shearing force which is needed to balance the tensile force on the interface between two helices. To find out the true origin of the mechanical stability of kinesin-1's NCC, we perform a novel and detailed mechanical analysis for the system based on molecular dynamics simulation at an atomic level. We find that the needed shearing force is provided by a buckle structure formed by two tyrosines which form effective steric hindrance in the presence of tensile forces. The tensile force is balanced by the tensile direction component of the contact force between the two tyrosines which forms the shearing force. The hydrophobic pressure balances the other component of the contact force perpendicular to the tensile direction. The antiunwinding strength of NCC is defined by the maximum shearing force, which is finally determined by the hydrophobic pressure. Kinesin-1 uses residues with plane side chains, tryptophans and tyrosines, to form the hydrophobic center and to shorten the interhelix distance so that a high antiunwinding strength is obtained. The special design of NCC ensures exquisite cooperation of steric hindrance and hydrophobic pressure that results in the surprising mechanical stability of NCC.

Observations of the Beam‐Driven Whistler Mode Waves in the Magnetic Reconnection Region at the Dayside Magnetopause

AbstractWe report observations of the whistler mode waves in the magnetic reconnection region at the dayside magnetopause using the magnetospheric multiscale (MMS) mission on January 11, 2016. In this event, whistlers mostly occur on the magnetospheric side of the reconnection central plane and are closely related to counter‐streaming electron beams in the medium energy range (200–300 eV). These counter‐streaming electron beams can be attributed to the accelerated magnetosheath electrons by the reconnection. Through quantitatively testing the Landau resonance condition and solving the kinetic dispersion relations, we present the evidence for whistler excitation by electron beams in the medium energy range. Additionally, the whistlers are observed simultaneously with the pitch‐angle scattering of electrons in the high‐energy range (300–3,000 eV). The calculation results show that this scattering is likely to occur through electron cyclotron wave‐particle interactions, which can isotropize electrons and exchange energy between plasmas and waves.

Fault Development Characteristics and Their Effects on Current Gas Content and Productivity of No. 3 Coal Seam in the Zhengzhuang Field, Southern Qinshui Basin, North China

Faulting is one of the most common geological features that impacts current gas content (CGC) of coal seams, which is an important parameter for coalbed methane (CBM/gas) production. However, the detailed faulting effects on CGC and productivity have not been thoroughly investigated, because of inadequate methods for quantitative evaluation of the effects. In this study, we carry out comprehensive analysis of diverse geological coring data and experimental results and production data of exploration wells as well as the three-dimensional fault interpretation in the Zhengzhuang field. We introduce a parameter fault scale (F) to quantify the scale of faults, which is described by fault length, fault throw, and the investigated area. Then we propose a horizontal grid method to determine the faulting influence on CGC. The relationships between the CGC and the fracture density of coal core, the mechanical properties of the roof and floor of coal seam, the average gas production in a faulting system (including the upthrown side, downthrown side, and fault plain) are analyzed. In the study area, the well-developed normal faults have significant influence on CGC, but the locally developed thrust faults have negligible influence. The square grid with length of 1.5 km is probably the most effective grids for analyzing faulting effected distance on CGC. Thus, the normal faults can be divided into small- (F1.5 < 0.05), moderate- (0.05 < F1.5 < 0.15), and large-scale (F1.5 > 0.15). The evident effect of faulting on CGC can be observed up to ∼1.5 km away from the normal fault. When the coal seam is further away from the normal faults (i.e., >1.5 km), the CGC is higher or closer to 20.7 m3/t. In contrast, when the coal seam is <1.5 km from the normal faults, the CGC decreases with increasing value of F. In general, the CGC is higher on the downthrown side, with better gas preservation conditions than the upthrown side. Relatively high CGC (>20 m3/t) is necessary for good gas production of CBM wells. The CBM wells with low ADGP (<500 m3/d) and low CTGP (<105 m3) are commonly located on the fault plane and upthrown side of normal faults. In general, the places far away (>1.5 km) from the normal faults is the most favorable productivity area, and only the small-scale normal faults developed is the secondary favorable productivity area. These places have the average gas production as high as 1000 m3/d and cumulative total gas production as high as 4 × 105 m3.

Anion Photoelectron Spectroscopy and Theoretical Studies of Al4C6-/0: Global Minimum Triangle-Shaped Structures and Hexacoordinated Aluminum.

Anion photoelectron spectroscopy and theoretical calculations were used to investigate the structural and bonding properties of Al4C6-/0 clusters. The vertical detachment energy of Al4C6- was measured to be 3.36 ± 0.08 eV. The structure of the Al4C6- anion is confirmed to be a bowl-shaped distorted triangle with an Al atom at the center and three Al atoms at the vertices. The global minimum isomer of neutral Al4C6 has a planar triangle-shaped structure with D3h symmetry. Both anionic and neutral Al4C6 have a hexacoordinated Al atom surrounded by three C≡C groups. Compared with the structure of neutral Al4C6, the structure of Al4C6- is distorted due to the addition of the excess electron. The molecular orbital analysis shows that the singly occupied molecular orbital of Al4C6- mainly locates on one side of the triangle plane and the neutral Al4C6 has a large highest occupied molecular orbital and lowest unoccupied molecular orbital gap. Theoretical calculations indicate that neutral Al4C6 has some aromaticity.

Thickness influence of veneering composites on fiber-reinforced systems

ObjectiveShort fiber reinforced composites (SFRC) require a veneering layer of conventional composite when used as restorations in the oral environment. The current study investigates the toughening effects during the path of a preexisting crack propagating through the bilayer system as it confronts the interface, through the attempted alignment of fibers and matrix-fiber interactions in the SFRC, and the distance it travels in the SFRC. MethodsBilayer systems of SFRC and conventional composite were produced with aligned fibers perpendicular to load direction. Single-edge-notched bend (SENB) specimens (25 × 5 × 2.5 mm3) with pre-crack length (a) to width (W) ratios (a/W = 0.2−0.8) were produced and tested in 3-point bending configuration until complete fracture. The specific work of fracture (we) was deduced from calculating the area under the load-displacement curves. Fiber alignment was digitally evaluated from images taken from the top and side planes of the specimen. ResultsThe toughness of the bilayer system is optimal when maximum SFRC thickness is used. EWF methods showed toughness and increasing nonessential work of fracture scaling with ligament length. A longer distance is accompanied by a higher distribution of aligned fibers bridging behind the crack wake, reducing crack driving forces at the crack tip. SignificanceSFRC materials provide increasing toughening potential with increasing thickness, and have the ability to be more anisotropic than other composite materials. Clinically, the layer must have a conventional composite cover layer, but which thickness does not affect toughness potential. Therefore the thickness of the conventional composite can be dictated by wear behavior.

Sex-specific Positioning of the Mating Structure in Scale-bearing Gametes of Monostroma angicava and Collinsiella cava (Ulvophyceae, Chlorophyta): A Possible Widespread Difference between Male and Female Gametes.

The gametes of chlorophytes can be divided into two morphological types (types α and β) based on the position of the mating structure relative to the flagella and eyespot. To elucidate the relationship between the morphological types and the sexes, we studied spatial relationships between the flagellar apparatus-eyespot-mating structures in biflagellate male and female gametes and their fate after fertilization in the anisogamous (Monostroma angicava) and the slightly anisogamous species (Collinsiella cava) using field emission scanning electron microscopy and transmission electron microscopy. The smaller male and larger female gametes of M. angicava had two basal bodies arranged at a 180° angle and the cell surface coated with square-shaped body scales, except for the flagella and mating structures. The mating structure of the female gamete was located on the same side of the flagellar beat plane as the eyespot (type β), whereas that of the male gamete was located on the opposite side (type α). This mating structure arrangement was also confirmed in C. cava. The initial fusion when male and female gametes were mixed involved the mating structures. In a fusing pair of gametes, each flagellum of one gamete lay alongside one flagellum of the other gamete. As fusion proceeded, the gamete pair transformed into a quadriflagellate planozygote, in which the four basal bodies were arranged in a cruciate pattern. The eyespots were positioned side-by-side on the same side of the cell. These results suggest that the two morphological types of gametes are intimately correlated with the particular sexes.

Hemodynamic and Flow Recirculation Effect on Rupture Prediction of Middle Cerebral Artery Aneurysm

The mortality and morbidity rate due to the severe effect of intracranial aneurysm (IA) is increasing, which has driven research trend on aneurysm rupture risk. By understanding the nature and causes of the aneurysm rupture, preventive measures could be taken in avoiding rupture besides recommending proper treatments such as endovascular coiling. However, the presence of flow recirculation causes the aneurysm wall to degenerate and weakened. The weakened wall is due to the haemodynamic factors such as velocity, wall shear stress (WSS), time average WSS (TAWSS), OSI and RRT, which were analysed in this study. In the present study, the flow model simulated a human patient-specific aneurysm at the apex of the bifurcation in the middle cerebral artery (MCA) in the transient state. Experimental results of full-scale models were collected on a median, side plane to study the flow behaviour and validation to the numerical simulation settings, which resulted in good agreement with only 8% difference. The simulation results obtained showed several interesting findings. The jet flow into the aneurysm led to complex vortex formation due to impinging flow behaviour within the aneurysm dome. Additionally, the area that recorded low velocity was at 30% of low TAWSS with only 1% of OSI that was more than 0.3, while the OSI critical value and 0.27% area exceeded RRT threshold, which caused the large oscillating blood flow direction and activated the atherosclerosis progression. These results suggest that the jet flow into the dome may cause further damage to the wall of the MCA aneurysm, which will help in providing an insight towards completing a guidance system assessment of rupture risk for medical practitioners in future work.

Correlation between Microstructure and Chemical Composition of Zinc Oxide Gas Sensor Layers and Their Gas-Sensitive Properties in Chlorine Atmosphere.

In this article, we present results concerning the impact of structural and chemical properties of zinc oxide in various morphological forms and its gas-sensitive properties, tested in an atmosphere containing a very aggressive gas such as chlorine. The aim of this research was to understand the mechanism of chlorine detection using a resistive gas sensor with an active layer made of zinc oxide with a different structure and morphology. Two types of ZnO sensor layers obtained by two different technological methods were used in sensor construction. Their morphology, crystal structure, specific surface area, porosity, surface chemistry and structural defects were characterized, and then compared with gas-sensitive properties in a chlorine-containing atmosphere. To achieve this goal, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL) methods were used. The sensing properties of obtained active layers were tested by the temperature stimulated conductance method (TSC). We have noticed that their response in a chlorine atmosphere is not determined by the size of the specific surface or porosity. The obtained results showed that the structural defects of ZnO crystals play the most important role in chlorine detection. We demonstrated that Cl2 adsorption is a concurrent process to oxygen adsorption. Both of them occur on the same active species (oxygen vacancies). Their concentration is higher on the side planes of the zinc oxide crystal than the others. Additionally, ZnO sublimation process plays an important role in the chlorine detection mechanism.

Planar capacitive imaging for composite delamination damage characterization

The objective of this study is to develop and validate a noncontact, nondestructive inspection and imaging method for rapidly assessing the subsurface condition of carbon fiber-reinforced polymer (CFRP) composite structures. The method works on the principle of planar electrical capacitance tomography (ECT). Unlike conventional ECT systems, electrodes are arranged on a rectangular planar surface in the form of a grid. The volume on one side of the electrode plane is interrogated with an electric field, and the mutual capacitances between the electrodes are measured. The volumetric electrical permittivity distribution of the interrogated region is then reconstructed from the measured capacitance responses. In this work, an ECT image reconstruction algorithm was implemented, and a customized planar capacitive imaging system was prototyped. First, different objects were placed near the electrode array, and the corresponding volumetric change in electrical permittivity was successfully captured. Second, the planar ECT system was employed for detecting artificially introduced subsurface defects in 3D-printed objects. Third, CFRP specimens with different sizes of single-layer delamination were fabricated and subjected to ECT interrogation. The results confirmed that the planar ECT system could detect the location and size of delamination in CFRP panels. The accuracy and resolution of the planar ECT prototype were also characterized.

Two-Level Stability Analysis of Complex Circuits

A new methodology is proposed for the small- and large-signal stability analysis of complex microwave systems, containing multiple active blocks. It is based on a calculation of the system characteristic determinant that ensures that this determinant does not exhibit any poles on the right-hand side (RHS) of the complex plane. This is achieved by partitioning the structure into simpler blocks that must be stable under either open-circuit (OC) or short-circuit (SC) terminations. Thus, the system stability is evaluated using a two-level procedure. The first level is the use of pole-zero identification to define the OC- or SC-stable blocks, which, due to the limited block size, can be applied reliably. In large-signal operation, the OC- or SC-stable blocks are described in terms of their outer-tier conversion matrices. The second level is the calculation and analysis of the characteristic determinant of the complete system at the ports defined in the partition. The roots of the characteristic determinant define the stability properties. The Nyquist criterion can be applied since, by construction, the determinant cannot exhibit any poles in the RHS. In addition, one can use pole-zero identification to obtain the values of the determinant zeroes. Because the determinant is calculated at a limited number of ports, the analysis complexity is greatly reduced.

Counter-realities and conflicted place: Gee Vaucher’s The Feeding of the Five Thousand in the punk art tradition

Abstract This article celebrates and critically examines Gee Vaucher’s artwork for the Crass album The Feeding of the Five Thousand (1978), drawing upon the enduring fascination that the work retains. Vaucher’s work is complex, disconcerting and mesmeric, and my intention is to pin down the facets of the work that achieve these qualities. The work sits in a tradition of collage and montage taken up in British punk and post-punk scenes, and I examine a selection of classic punk artworks in comparison to Dada artworks that represent the origins of radical montage art. Whilst acknowledging the established mode of interpreting this work through indexical context of elements and the force of juxtaposition (e.g. Linder Stirling’s punk work), I argue that Vaucher’s work achieves something more and requires additional methods of analysis. By developing a formalist approach of illusionistic harmony and integrity, I consider the space of the picture plane, as a traditional art concept and the space and place of the depicted behind the picture plane. Vaucher’s work offers an enduring feeling of a conflicted, disrupted and corrupted space – you feel you can step into a real space within the picture but prefer to hover on the safe side of the picture plane. This property embodies what the author Mark Fisher calls the ‘weird and the eerie’. I then examine a number of artworks from within and around the canon of art – Alison and Peter Smithson, Martha Rosler and Tish Murtha – finding images that I feel have a strong resonance with Vaucher’s work in terms of the spaces they construct and the mode of construction. These canonical works offer some developed critical dialogue to bring to bear on Vaucher’s work in order to fully understand the power of this iconic record sleeve.

Delocalized Surface Electronic States on Polar Facets of Semiconductor Nanocrystals.

Wurtzite CdSe@CdS dot@platelet nanocrystals with (001) and (00-1) polar facets as the basal planes and (100) family of nonpolar facets as the side planes are applied for studying surface defects on semiconductor nanocrystals. When they are terminated with cadmium ions coordinated with carboxylate ligands, a single set of absorption features and band-edge photoluminescence (PL) with near unity PL quantum yield and monoexponential PL decay dynamics (lifetime ∼28 ns) are observed. In addition to these spectral signatures, when the surface is converted to sulfur-terminated, a second set of sharp absorption features with decent extinction coefficients and a secondary band-edge PL with low PL quantum yield and long-lifetime (>78 ns) PL decay dynamics are reproducibly recorded. Photochemical analysis confirms that the secondary UV-vis and PL spectral features are quantitatively correlated with each other. Chemical analysis and X-ray photoelectron spectroscopy measurements confirm that such secondary spectral features are well correlated with the sulfide (such as -SH) and disulfide (such as -S-S-) surface sites of a basal plane, which likely form surface hole electronic states delocalized on the entire basal plane. Results suggest that, for studying surface defects on semiconductor nanocrystals, it is essential to prepare a nearly monodisperse surface structure in terms of facets and surface chemical bonding.

Optimal output feedback control of a class of uncertain systems with input constraints using parallel feedforward compensator

In this paper, an output feedback control approach based on online optimization for a class of constrained-input systems with uncertainties is presented. For this propose, the system is augmented with the aid of a Parallel Feedforward Compensator (PFC), which is designed based on an inaccurate linear model. The proposed method is performed by placing the transmission zeros of the augmented linear system at the left-hand side of the complex plane, creating a systematic and LMI-based procedure. It is worth noting that the method improves many commonly adopted restrictive assumptions on the linear model and is applicable for a class of nonlinear systems as well. In the augmented system, the augmented output is considered to form the external states, while the other linearly independent variables constitute the internal dynamics. The control signal is derived by finding online solution of a Quadratic Programming (QP) problem. This problem regulates the augmented output over a constrained input space, producing an optimal control law. Online solution of the QP is computed using a Recurrent Neural Network (RNN). Guaranteed stability and rapid convergence to the optimal solution are among advantages of such networks, which make the proposed control method more reliable. Furthermore, boundedness of the internal states during regulation of the external states is ensured in the presence of a class of uncertainties and nonlinearities. Effectiveness of the proposed method illustrated using a simulating example.

The Mechanism of the Intramolecular Hydrocarbyl Metathesis within a Planar Triruthenium Cluster: Combining Core Flexibility with Hydride Mobility.

The transition metal catalysed formation and cleavage of C-C bonds is of utmost importance in synthetic chemistry. While most of the existing homogeneous catalysts are mononuclear, knowledge of the behaviour of polynuclear species is much more limited. By using computational methods, here we shed light into the mechanistic details of the thermally-induced isomerization of Cp*3 Ru3 (μ-H)2 (μ3 -η2 -pentyne)(μ3 -pentylidyne) (2) into Cp*3 Ru3 (μ-H)2 (μ3 -η2 -octyne)(μ3 -ethylidyne) (3), a process that involves the migration of a C3 fragment between the hydrocarbyl ligands and across the plane formed by the three Ru centres. Our results show this to be a complex transformation that comprises of five individual rearrangements in an A→B→A→B→A order. Each so-called rearrangement A consists of the CH migration from the μ3 -η2 -alkyne into the μ3 -alkylidine ligand in the other side of the Ru3 plane. This process is facilitated by the cluster's ability to adopt open-core structures in which one Ru-Ru bond is broken and a new C-C bond is formed. In contrast, rearrangements B do not involve the formation or cleavage of C-C bonds, nor do they require the opening of the cluster core. Instead, they consist of the isomerization of the μ3 -η2 -alkyne and μ3 -alkylidyne ligands on each side of the triruthenium plane into μ3 -alkylidyne and μ3 -η2 -alkyne, respectively. Such transformation implies the migration of three H atoms within the hydrocarbyl ligands, and in this case, it is aided by the cluster's ability to behave as a H reservoir. All in all, this study highlights the plasticity of these Ru3 clusters, whereby Ru-Ru, Ru-C, Ru-H, C-C, and C-H bonds are formed and broken with surprising ease.

Semicircular shape hybrid reconfigurable antenna on Jute textile for ISM , Wi‐Fi , Wi‐MAX , and W‐LAN applications

This article presents the development of a conformal reconfigurable frequency circularly polarized jute textile antenna, working at 2.4, 3.5, 5.8, and 5.9 GHz in Wi-Fi, Wi-MAX, Industrial, Scientific and Medical radio bands and W-LAN. The antenna topology is based on a semicircular structure as the main radiating component. The conductivity is realized by using copper paint, which was brush-painted. The patch structure is rehashed in another side of the substrate against the ground with a rotation turn 180°. Two BAR64-03 W PIN diodes switches are placed in between a semi-elliptical structure and a rectangular structure on the bottom side of the ground plane. By governing the state of the switches, this antenna can operate at different operating frequencies. Furthermore, the antenna has an accomplished axial ratio (AR) of less than 3 dB for resonating frequencies at all four switching states. Other electromagnetic properties of the proposed jute textile antenna accomplished in simulations were confirmed through the measurement of the antenna in an anechoic chamber. The reconfigurable circularly-polarized jute textile antenna shows a peak gain of 4.93, 5.67, 8.86, and10.07 dBi at 2.4, 3.5, 5.8, and 5.9 GHz (Wi-Fi, Wi-MAX, ISM, W-LAN).