Open Configuration Research Articles

Comparative Study of Soft Tissue and Hard Tissue Variables Correlation between Two Different Racial groups: A Canonical study

Aims: The purpose of this study was to investigate the correlation between dental, skeletal, and soft tissue variables and compare the results with Saudi study and other previous studies. Material and Method: The sample size consisted of 29 adult Sudanese patients (ages 18 to 25) seeking orthodontic treatment, and 19 variables were examined. The error of the method was assessed using Student's t-test, and canonical correlation analysis was used to analyze the correlation between soft and hard tissues. Results: The study found that the Sudanese population had higher mean values in dental and soft tissue variables compared to the Saudi population, while similar mean values were found in the skeletal sagittal relationship, except for the vertical relationship, where the Saudi population had a higher tendency for an open basal configuration. The canonical analysis revealed that the upper and lower incisors' inclinations had a strong negative loading, while the nasolabial angle and lower lip thickness and position had moderate loading. Conclusion: These findings show the impact of these variables which can help the clinician in diagnosis, prediction and assessment of post treatment changes. Additionally, the multivariate statistical analysis extracted a clinically significant association between soft tissue and hard tissue.

A Multi-Path Approach to Protect DNS Against DDoS Attacks

Domain Name System (DNS) is considered a vital service for the internet and networks operations, and practically this service is configured and accessible across networks’ firewall. Therefore, attackers take advantage of this open configuration to attack a network’s DNS server in order to use it as a reflector to achieve Denial of Service (DoS) attacks. Most of protection methods such as intrusion prevention and detection systems use blended tactics such as blocked-lists for suspicious sources, and thresholds for traffic volumes to detect and defend against DoS flooding attacks. However, these protection methods are not often successful. In this paper, we propose a new method to sense and protect DNS systems from DoS and Distributed DoS (DDoS) attacks. The main idea in our approach is to distribute the DNS request mapping into more than one DNS resolver such that an attack on one server should not affect the entire DNS services. Our approach uses the Multi-Protocol Label Switching (MPLS) along with multi-path routing to achieve this goal. Also, we use threshold secret sharing to code the distributed DNS requests. Our findings and results show that this approach performs better when compared with the traditional DNS structure.

Fully Open Ring Microcavities Based on Metagratings

Open optical microcavities are crucial to precise manipulation of light–matter interaction in solid‐state and biological systems. However, only open linear microcavities are practically realized, limiting the application of open microcavities in more scenarios. Herein, an ease‐fabrication fully open ring microcavity is theoretically demonstrated that supports simultaneously multiple concentric cavity modes with coupling interaction. It comprises two orthogonal dielectric metagratings, which are a single layer of silicon rods and enable transmitted waves to travel in a negative angle. Except for fully open configuration, the open microcavity also incorporates the advantages of low absorption loss and the compatibility to the current CMOS process. It offers a unique platform for controlling the interaction between light and atoms, molecules, nanoparticles, or biomolecules and will find a broad range of applications.

Preparation and Properties of Three Plasticiser-Free Novel Di-benzo-18-Crown-6 Aldimine-Derived Lead(II) Ion-Selective Electrodes

Three novel dibenzo-18-crown-6 aldimines were successfully synthesised and structurally characterised via various spectroscopic methods (1H,13H NMR, FT-IR) and their solution phase lead binding behaviours probed via absorption spectroscopy, the results are supported by Density Functional Theoretical (DFT) modelling. These methods revealed that the asymmetric nature of these compounds is such that at equilibrium the ether cavity adopts an open configuration where the constituent oxygen atoms exhibit a highly negative electrostatic potential; hence, they spontaneously (ΔG~−58 kJ mol−1) interact/bind aqueous lead ions to form stable 2:1 metal–ligand complexes. As indicated by cyclic and square voltammetry studies, all compounds are redox active and polymerise relatively easily onto a platinum surface to form a multi-layered lead Ion-selective Membrane (ISM), the structure of which is confirmed by Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). These novel Ion-selective Electrodes (ISEs), as characterised by Differential Pulse Anodic Stripping Voltammetry (D PASV), allow selective electrochemical detection and quantification of lead at concentrations as low as 10 ppm, over a range of 15–60 ppm, with only minimal interference from mercury(II) and aluminium(III) ions at a 1:1 analyte-interferent ratio.

Nonlinear Performance Curve Estimation of Unreinforced Masonry Walls Subjected to In-Plane Rocking Behavior

This study focused on the in-plane rocking behavior of unreinforced masonry (URM) walls. Three URM wall specimens were designed and fabricated based on a typical masonry house in Korea. The experimental parameters were the layout of openings (its presence or absence) and configuration of openings (window or door). Static cyclic loading tests were conducted to investigate nonlinear performance curves of masonry walls subjected to a rocking behavior in the in-plane direction. In this paper, the mortar-joint tensile crack strength and rocking strength of masonry walls (i.e., peak and residual strengths) were evaluated, and the effects of opening configurations on the masonry wall strength were examined, due to the proposed procedure. The deformation capacity of a rocking behavior was also identified by the procedure. As a result, specimens without initial cracks showed the rocking behavior after mortar-joint tensile crack failure, whereas a specimen with initial cracks exhibited only the rocking behavior. Since no remarkable strength deterioration was found until final loading in all specimens, an in-plane rocking URM wall may have very good deformation performance. The estimated mortar-joint tensile crack strength, rocking strength, stiffness, and ultimate deformation were in good agreement with the experimental results, regardless of the layout and configuration of openings.

Suppression of bremsstrahlung losses from relativistic plasma with energy cutoff.

We study the effects of redistributing superthermal electrons on bremsstrahlung radiation from hot relativistic plasma. We consider thermal and nonthermal distribution of electrons with an energy cutoff in the phase space and explore the impact of the energy cutoff on bremsstrahlung losses. We discover that the redistribution of the superthermal electrons into lower energies reduces radiative losses, which is in contrast to nonrelativistic plasma. Finally, we discuss the possible relevance of our results for open magnetic field line configurations and prospects of the aneutronic fusion based on proton-boron-11 (p-B11) fuel.

Experimental study of fire containment using water mist curtains in a reduced-scale deck of a ro-ro ship

Experiments have been conducted to evaluate the containment of smoke and heat using water mist curtains in a model setup of a ro-ro ship's cargo deck with a scale of 1:13, providing practical insights into the application of such fire protection systems in the cargo deck as well as valuable data for future numerical simulations. In this regard, the requirements of the international convention of Safety of Life at Sea (SOLAS) are studied for the side openings of so-called ‘open decks’ in comparison with ‘closed decks’, especially to examine the feasibility of using water mist curtains for creating isolated subdivisions in the ro-ro space as a fire management strategy. The water mist curtains are created with one or two rows of water mist nozzles at pressures ranging from 3 to 8 bar, while the source of smoke and heat is a liquid pool fire, and inert cargo items are used in some experiments. Correspondingly, the interaction between the water mist curtain(s) and the fire is evaluated in terms of its heat release rate, and the containment effect is quantified via measurements of smoke flow through the deck and through the windows, concentrations of gaseous species, as well as gas temperatures at various key locations. The study shows that water mist curtains have a strong effect on fire dynamics and smoke propagation, but containment is dependent on the configuration of side openings and the location of fire, among other important factors.

Numerical analysis of conjugate convection heat transfer in an open cavity with different phase change materials surrounded by plexiglass

Phase change (PC) process and convection inside an open cavity equipped with two different PCMs are analyzed with the finite volume method with ANSYS Fluent. The analysis is conducted for three different Grashof number (Gr) values for fully and partly open configurations. It is observed that the PC becomes fast when the object is closer to the exit for the fully open case. The partly open case results in higher thermal performance improvements while the average Nusselt number (Nu) increment is 94.5% for PCM-18. PC and heat transfer characteristics are influenced by both material and location of the PCM. At Gr = 3.79 × 108, the average Nu rises by about 50% when PCM-22 is used instead of PCM-18. Location and type of PCM provide excellent tool for controlling the phase transition and heat transfer dynamics with a fully and or partly open cavity.

Constraints on the Ratio between Tropical Land and Ocean Precipitation Derived from a Conceptual Water Balance Model

Abstract Which processes control the mean amounts of precipitation received by tropical land and ocean? Do large-scale constraints exist on the ratio between the two? We address these questions using a conceptual box model based on water balance equations. With empirical but physically motivated parameterizations of the water balance components, we construct a set of coupled differential equations that describe the dynamical behavior of the water vapor content over land and ocean as well as the land’s soil moisture content. For a closed model configuration with one ocean and one land box, we compute equilibrium solutions across the parameter space and analyze their sensitivity to parameter choices. The precipitation ratio χ, defined as the ratio between mean land and ocean precipitation rates, quantifies the land–sea precipitation contrast. We find that χ is bounded between zero and one as long as the presence of land does not affect the relationship between water vapor path and precipitation. However, for the tested parameter values, 95% of the obtained χ values are even larger than 0.75. The sensitivity analysis reveals that χ is primarily controlled by the efficiency of atmospheric moisture transport rather than by land surface parameters. We further investigate under which conditions precipitation enhancement over land (χ > 1) would be possible. An open model configuration with an island between two ocean boxes and nonzero external advection into the domain can yield χ values larger than one, but only for a small subset of parameter choices, characterized by small land fractions and a sufficiently large moisture influx through the windward boundary.

Enteric glia: genomically open, poised, and ready to make neurons.

The heterogeneity and multiple functions of enteric glia have recently been recognized. Guyer et al. have now confirmed the neurogenetic potential of enteric glial cells and have also found that some have an open chromatin configuration, suggesting that some glial cells are poised and ready to differentiate into neurons.

Proximal segmental ostectomy under standing sedation for treatment of open comminuted axially displaced fractures of the fourth metatarsal bone in two horses

SummaryTwo cases with open, comminuted, axially displaced fractures of the proximal third of the fourth metatarsal bone were referred to the University Equine Hospital Vienna. Due to concerns regarding the risk of injury to the suspensory ligament and risk of implant infection with an open configuration, surgical treatment with proximal ostectomy of the fractured fourth metatarsal bone was performed in both cases. Based on telephone follow‐up, Case 1 was reported to be sound with no significant reaction at the surgical site 22 months following the procedure and Case 2 exhibited intermittent lameness, radiographically evident irregular new bone formation and some residual ultrasonographic changes of the proximal suspensory ligament 17 months after the procedure. Based on the results of this report, a proximal ostectomy facilitated by standing sedation and regional anaesthesia is a valid treatment option in cases of open, axially displaced fractures of the fourth metatarsal bone, minimising perioperative complications but not excluding long‐term postoperative complications.

Shape parameters optimisation of a quayside heaving rectangular wave energy converter

In order to increase the competitiveness of wave energy industry, device’s efficiency and cost have to be both optimised. This study is a contribution to this approach by presenting the optimisation of a quayside rectangular float. This configuration has been chosen since quayside systems present the advantage of greatly reducing maintenance and grid connection costs. Moreover, rectangular shapes enable us to validate the optimisation algorithm with a linear potential model. Thus, the evolutionary algorithm CMA-ES (Covariance Matrix Adaptation-Evolutionary Strategy) is used to perform Capture Width (CW) optimisations in regular and irregular waves. Results with and without a vertical wall are compared. In an open sea configuration, at a given frequency, the shape that maximises efficiency is a horizontal flat rectangle with a minimum draft and a breadth equals to a half wavelength. The presence of the wall doubles the CW compared to the case in open sea. Moreover, for a quayside case, one optimal shape for a given draft has a breadth twice smaller than the open sea case. In addition, the resonances of the water column in the gap between the float and the dike, that occur in regular waves, lead to various possible optimised shapes. However, only the shape corresponding to a minimum draft and a quarter of the wavelength wide is also recovered in irregular waves. This shape also appears to be less dependent to the clearance distance between the float and the vertical wall. Finally, bi-objective optimisation results are realised in irregular waves for a rectangular quayside float in order to maximise the CW and minimise the WEC (Wave Energy Converter) cost. A significant cost reduction is possible by reducing the float immersed surface and volume. It is shown that a reduction of the float’s breadth of 50% from the optimal value only reduces the CW of about 7%.

Cohesin SMC1β promotes closed chromatin and controls TERRA expression at spermatocyte telomeres.

Previous data showed that meiotic cohesin SMC1β protects spermatocyte telomeres from damage. The underlying reason, however, remained unknown as the expressions of telomerase and shelterin components were normal in Smc1β -/- spermatocytes. Here. we report that SMC1β restricts expression of the long noncoding RNA TERRA (telomeric repeat containing RNA) in spermatocytes. In somatic cell lines increased TERRA was reported to cause telomere damage through altering telomere chromatin structure. In Smc1β -/- spermatocytes, we observed strongly increased levels of TERRA which accumulate on damaged chromosomal ends, where enhanced R-loop formation was found. This suggested a more open chromatin configuration near telomeres in Smc1β -/- spermatocytes, which was confirmed by ATAC-seq. Telomere-distal regions were not affected by the absence of SMC1β but RNA-seq revealed increased transcriptional activity in telomere-proximal regions. Thus, SMC1β promotes closed chromatin specifically near telomeres and limits TERRA expression in spermatocytes.

Experimental study and structural analysis of tapered steel beams with cellular openings

As cellular beams are increasingly used in steel construction, different configurations, including tapered cellular beams, are emerging. Steel beams with cellular openings that are tapered have several benefits, as they combine the benefits of an optimally tapered cross-section with practical cellular advantages. To the best of the author's knowledge, the existing literature only contained analytical and numerical studies on tapered cellular beams. Due to the lack of experimental data, an experimental investigation of six tapered specimens with various circular web opening configurations is presented. The geometry of the tested specimens was discussed, and all specimens have narrow web-posts. The tapered cellular I-sections were tested as cantilevers with fixed support and under a vertical concentrated load. Material properties, manufacturing, supports and test-setup were provided. Factors affecting the behavior of the tested specimens, such as taper angles, optimizing the opening diameter and the opening arrangements, were investigated. The results showed that changing the taper angles had an effect on the buckling strength of the investigated beams. In the meantime, optimizing the opening diameter increases the ultimate strength. A structural analysis of a single web-post was presented, and the experimental specimens' web buckling resistance was determined using the simple strut model. The buckling lengths presented in literature were discussed. The results of the analytical methods demonstrated that the change made by Panedpojaman et al. [1] for estimating the buckling strength was visible and more conservative for tapered cellular beams.

Characterization, LCA and FEA for an efficient ecodesign of novel stainless steel woven wire mesh reinforced recycled aluminum alloy matrix composite

The production of metal matrix composites generally requires higher energy and raw materials consumption, while generating more waste than conventional material processing. The possibility of reusing recycled aluminum as an alternative in the production of metal matrix composites has led to the interest in this research as it can contribute to aluminum waste and raw reduction as well as to environmental impact mitigation. This paper provides an in-depth investigation of a brand-new metal matrix composite that is produced by gravity casting. In turn, the process is based on recycled aluminum EN AW 6082 for the matrix that is reinforced with stainless steel AISI 304 woven wire mesh that is intended for industrial and commercial use. A detailed description of the production procedure is reviewed, as are the vales of toughness, yield and tensile strengths that were determined by standardized tensile and Charpy tests. Life Cycle Assessment and Finite Element Analysis were used to determine, respectively, the environmental impact and the residual stresses generated during the production of the specimens for the above mentioned tests. Five different opening and wire diameter configurations for the AISI 304 woven wires were studied in this work. In a comparison to recycled aluminum alloy EN AW 6082 without reinforcement, the best results were provided by the 2.177 mm × 0.6 mm configuration. These results were the following: (1) Yield, tensile strength and toughness showed an increase of 245.5%, 13.62% and 175.0% respectively. (2) Life Cycle Assessment increased 8.31% for the highest environmental impact obtained (Human Toxicity). (3) The Finite Element Analysis showed that the residual stresses increased in their compressive values in −10.83 MPa, −9.925 MPa and −3.84 MPa, respectively, for the stainless steel wires, aluminum matrix and wire/matrix interfaces. From the mechanical properties, the environmental impacts and the residual stresses that were obtained, one can conclude that this study has demonstrated a technically feasible practical approach to the use of the recycled aluminum alloy EN AW 6082 using AISI 304 stainless steel woven wires as materials in the metal matrix composites production. This could lead to a substantial reduction in the volume of aluminum used and, consequently, provide environmental and economic benefits.

Effects of open space configurations and development patterns on future urban wildlife habitats and populations

The viability of wildlife populations in cities is strongly associated to the qualities of urban open spaces and development patterns. Open space systems can serve as armatures to address adverse effects of urbanization on biodiversity. Landscape planners and designers use spatial concepts to translate principles of landscape ecology into working diagrams of land use and land cover to anticipate ecological effects. This paper investigates the consequences of adopting different open space spatial concepts (corridors, patches, and network) in combination with development patterns (compact and dispersed), simulated in eight alternative future scenarios with computer model Envision. Two approaches were used to quantify the effects of the different spatial concepts and urban patterns on Red-legged frog (RLF), Western meadowlark (WML), and Douglas squirrel (DSQ) habitats and populations in an area of urban expansion. First, the amount of habitats was assessed for the initial landscape (ca. 2010) and for the eight future scenarios (year 2060). Second, using the Individual-Based Model (IBM) HexSim, populations of the three species were quantified. All scenarios had increased sums of habitat area, but results showed that differences in open space spatial concepts played a greater role in determining population sizes and were more influential than different development patterns. Network scenarios presented more habitats and the largest populations of RLF. Park and network scenarios showed the most habitats and populations for the WML. No open space and greenway scenarios did not have enough habitats for the WML, but presented the best results for the DSQ. Populations in compact development scenarios showed a small advantage over most dispersed development scenarios. However, in park and network scenarios, dispersed development showed a large influence in the increase of WML population. The study shows that the adopted framework is useful to predict the consequences of landscape plans on wildlife species populations, evaluate trade-offs, and inform planning decisions.

SOLPS-ITER simulations of a vapour box design for the linear device Magnum-PSI

A vapour box (VB) is a physical device currently being considered to reduce the high heat and particle fluxes typically impacting the divertor in tokamaks. This system usually consists of a series of boxes that retains neutral particles to increase the amount of collision events with the impacting plasma. The neutral particles come from recycling and recombination of the plasma, gas puffing inside the box and by the evaporation of a liquid metal, typically Li or Sn. Currently, an VB is being constructed for testing in the linear plasma generator Magnum-PSI, operated at DIFFER. Its modular design will allow for open (not enclosing the target) and closed (enclosing the target) configurations, as well as evaporating a liquid metal to create a vapour cloud inside the box. The experiments carried out with this device will investigate its capabilities to reduce the plasma flux towards the target. This work presents a numerical study performed with SOLPS-ITER about the effectiveness of the current VB design in its open configuration to retain neutrals and its effect on the plasma beam properties. This is a first step before validation against experiments and studying closed configurations to ensure that the VB can successfully operate in a wide range of plasma parameters. Simulations show that the VB is capable of retaining neutrals and reducing fluxes to the target without requiring additional gas puffing in High and Low plasma flux scenarios. When lithium is evaporated from inside the box, the hydrogen plasma is completely extinguished and replaced by a low temperature Li plasma with lower flux. The fraction of Li and Li+ transported upstream the VB is three orders of magnitude below the amount evaporated form the central box, as most of the lithium is condensed in the side boxes and another small portion (two orders of magnitude below the amount evaporated) is deposited on the target. The VB design in its open configuration can mitigate incoming plasma peak heat flux by , which represents a fraction of and for the High and Low flux scenarios. This effect is expected to be higher when a closed configuration is employed, which could result in a significant reduction of heat fluxes on the divertor of tokamaks once that this design is extrapolated to the toroidal geometry, with just a minimal amount of Li and Li+ reaching the core.

Optimization of Rhombus Opening Area of Shear Walls On Tall Buildings

This research was designed to determine the optimum percentage and configuration of rhombus opening on shear wall of tall building. A residential tall building of 12-storeys having base size of 20m × 10m with height of floor of 3m was analyzed. In this paper, percentages of 12%, 24%, 36%, 42%, and 54% concentric rhombus opening in a shear wall in tall buildings were modeled. The effect of the opening size on the lateral displacement, base shear, and stress at the opening was determined. It was found that the opening of 12% has less lateral displacement, base shear, and stress at the opening. This indicates that this opening delivers the best performance among the other percentages. Five models with the same percentage of rhombus opening of 12% at different configuration on the shear wall in tall buildings were modeled to determine the optimum configuration of opening on shear walls. It was found that Model-1 is the optimum configuration since this model has the lowest lateral displacement and stress at the opening. It can be concluded that Model-1 with 12% opening area is the optimum size and configuration to resist lateral force on tall buildings.

Influence on Structural Loading of a Wave Energy Converter by Controlling Variable-Geometry Components and the Power Take-Off

AbstractOceans are harsh environments and can impose significant loads on deployed structures. A wave energy converter (WEC) should be designed to maximize the energy absorbed while ensuring the operating wave condition does not exceed the failure limits of the device itself. Therefore, the loads endured by the support structure are a design constraint for the system. Furthermore, the WEC should be adaptable to different sea states. This work uses a WEC-Sim model of a variable-geometry oscillating wave energy converter (VGOSWEC) mounted on a support structure simulated under different wave scenarios. A VGOSWEC resembles a paddle pitching about a fixed hinge perpendicular to the incoming wave fronts. The geometry of the VGOSWEC is varied by opening a series of controllable flaps on the pitching paddle when the structure experiences threshold loads. It is hypothesized that opening the flaps should result in load shedding at the base of the support structure by reducing the moments about the hinge axis. This work compares the hydrodynamic coefficients, natural periods, and response amplitude operators from completely closed to completely open configurations of the controllable flaps. This work shows that the completely open configuration can reduce the pitch and surge loads on the base of the support structure by as much as 80%. Increased loads at the structure’s natural period can be mitigated by an axial power take-off damping acting as an additional design parameter to control the loads at the WEC’s support structure.

Theoretical and experimental studies of W-band relativistic surface-wave oscillator of planar geometry

This paper presents the results of theoretical and experimental studies of a surface-wave oscillator (SWO) of planar geometry excited by a ribbon high-current relativistic electron beam. Within the framework of the quasi-optical approach and direct three-dimensional particle-in-cell modeling, we demonstrate the advantages of open transverse edged configuration against the closed one for effective mode selection at a fairly large oversize factor. In the experiments carried out on the basis of the SINUKI accelerator (Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, 1 kA/650 keV/17 ns), we form a magnetically guided ribbon electron beam with a cross-section of 0.3 × 20 mm2, which moves parallel to a slow-wave structure with a period of 1.75 mm. A planar W-band SWO both of open and closed edged configuration has been experimentally tested. In full agreement with modeling, the open configuration exhibits much more stable operation, where at a frequency of 75 GHz, we observe pulse generation with duration of about 7 ns. The output power measured by the calorimetric method reaches 25 MW.