Dynamic Stability Research Articles

Half‐Metallic Ferromagnetism in 2D Janus Monolayers: Mn2GeX (X = As, Sb)

Two‐dimensional (2D) Janus materials are a fascinating class of materials resulting from their unique electronic and magnetic properties induced by mirror symmetry breaking. However, 2D Janus materials with intrinsic magnetism remain rather rare, casting a mysterious veil over magnetism. In this work, the electronic and magnetic properties of Janus Mn2GeX (X = As, Sb) monolayers using the first‐principles calculations are investigated. The results demonstrate that these Janus materials exhibit excellent mechanical and dynamic stability, indicating their potential for future applications in nanoscale spintronic devices. Interestingly, the Janus and monolayers possess exciting half‐metallic character with wide half‐metallic gaps of 0.29 and 0.18 eV, and spin gaps of 1.68 and 1.62 eV, respectively. Their calculated ground state exhibits a strong preference for ferromagnetic ordering, with a Curie temperature () of 630 and 590 K, respectively. Additionally, the ferromagnetism of Janus Mn2GeX (X = As, Sb) monolayers is robust against biaxial strain ranging from −6% to 6%. Under 6% tensile strain, the calculated of the monolayer is 639 K, which represents a 9% increase compared to the observed in the unstrained condition. All these intriguing electronic and magnetic properties make the Janus Mn2GeX (X = As, Sb) monolayers an appealing candidate for applications in nanoscale spintronic devices.

Two-dimensional BC12 as an ultra-high performance anode material for lithium-ion batteries

With the gradual development of renewable energy, search for high-performance energy storage materials as anodes for lithium-ion batteries (LIBs) has become urgent. Two-dimensional (2D) materials are considered as candidates for anode materials due to their unique structure and physicochemical properties. Based on first-principles calculations, we propose a 2D material, BC12 monolayer, as an excellent anode for LIBs. BC12 exhibits outstanding dynamic, mechanical, and thermal stability. In addition, BC12 monolayers show not only remarkably high storage capacity (2767.57 mA h g−1) but also low diffusion barrier energy (0.175 eV) and appropriate open circuit voltage (0.3 V). A small volume expansion (0.38%) is also observed during the lithiation process. Furthermore, we undertake a comprehensive analysis on the impact of carbon vacancy in BC12. The presence of carbon vacancy makes the adsorption and diffusion of Li relatively weak, which should be carefully handled in the experimental synthesis process. The above-mentioned investigation offers valuable insights and guidance for the future development and application of 2D anode materials in metal-ion batteries.

In Silico and In Vitro Evaluation of Bioactive Compounds of Vallisneria spiralis L. against Candida albicans

Background This study focused on the extraction, isolation, characterization, and molecular docking of phytochemicals from Vallisneria spiralis L. to determine its antifungal activity. Natural products and structural analogs have always played an important role in pharmacotherapy, particularly in the treatment of infections and malignancies. Methods Vallisneria spiralis L. leaves were pulverized into a fine powder and extracted using a Soxhlet apparatus, and the crude chloroform extract was separated by flash column chromatography. Thin-layer chromatography was used to assess the obtained fractions. Infrared spectra were obtained using a Perkin Elmer spectrometer. NMR spectra were collected using a Bruker spectrometer. Qualitative phytochemical investigations were performed to identify compounds in the extracts. The susceptibility of the test compound to Candida albicans was assessed using disk diffusion. A docking study was conducted to dock the three-dimensional structures of the extracted phytocompounds of Vallisneria spiralis L. into the receptor site of the target proteins using Autodock software. MD simulations were used to study the dynamic behavior, conformational changes, and stability of the proteins using the top three hit chemicals. Results These results suggest that Vallisneria spiralis L. extract contains various phytoconstituents, including carbohydrates, tannins, flavonoids, steroids, terpenoids, and glycosides. The distinctive functional groups of the extract were identified using a Fourier-Transform Infrared (FTIR) spectrophotometer. Nuclear Magnetic Resonance (NMR) spectroscopy was used to determine the structures of the isolated and purified extracts. The antifungal activity of Vallisneria spiralis L. extract against Candida albicans was found to be significantly stronger at a concentration of 200 mg/mL. Conclusion The findings of the study were obtained using in vitro and in silico methods to investigate the antifungal effect of Vallisneria spiralis L., which highlighted it as a potential natural antifungal treatment for Candida infection, which could be further investigated.

Variable angle tow-steered fibres based rotating composite beam with rotary oscillations – Parametric excitation/instability analysis

This study is concerned with the stability analysis for various vibrational motions of tow-steered variable angle fibres based composite rotating beam with time varying speed. The formulation combines a higher order theory introducing sine function along with finite element methodology. It satisfies the plane stress condition in width direction of beam. The displacement kinematics are generic in the sense it includes various possible vibrational motions like chord and flap wise motions, torsional and axial vibration behaviours. The equilibrium equations for the proposed problem evolved adopting virtual dynamic work are then transformed into the equations of Mathieu-Hill type considering time varying harmonic rotational speed. Using Bolotin’s procedure coupled with C1 continuity-based beam element, the parametric resonance zones along with boundary limits are numerically evaluated. The eigenvalue type of solution methodology applied for the detailed study is validated for accuracy and computational efficiency against the time domain dynamic response analysis. Based on in-depth analysis, dynamic instability characteristics in terms of resonance range and origin of instability of composite beam subjected to the chord and flap wise, torsional and axial motions are studied considering curvilinear fibre path angles, beam cross section, hub radius, thickness ratio and mean rotary speed.

Tuning of optical, thermodynamic, and thermoelectric properties of Cs2CuBiX6 (X = Cl, Br, I) halide perovskites for solar cells and energy harvesting applications

The double perovskites are outstanding materials for solar cells and transport applications to clean harvest energy. Therefore, the Cs2CuBiX6 (X = Cl, Br, I) are discussed comprehensively for energy harvesting by modified Becke and Johnson (mBJ) potential. The studied DPs fit the structural, mechanical, and dynamic stability scale by tolerance factor, Born–Huang criteria, and phonon dispersion band structures. The band gaps (1.20, 1.0, 0.70) eV for (Cl, Br, I) based DPs ensure the Cs2CuBiCl6 has an absorption band in the visible region while Cs2CuBiBr6 and Cs2CuBiI6 has an absorption band in the infrared region. Heavy elements’ spin–orbit coupling effect (Cs, Bi) reduces the band gap to 0.08 eV. Thermoelectric behavior regarding the merit scale against dopant carriers and temperature has been elaborated. The ultralow lattice thermal conductivity, large Debye temperature, hardness, and melting temperature increase their implication for thermoelectric and other thermodynamic applications. The variation in band gap makes them important for diverse optoelectric and thermoelectric applications. The Cs2CuBiCl6 with a band gap of 1.20 eV is suitable for solar cells, while Cs2CuBiBr6 and Cs2CuBiI6 with band gaps of 1.0 eV and 0.70 eV are significant for thermoelectric generators.

Investigation of the dynamics of transverse oscillations of a vertical rod under gravity, friction, and thermal expansion

The paper considers the mathematical formulation of the problem of transverse oscillations of a vertical rod under gravity, friction and external pulse effect, leading to thermal expansion of the rod. The dynamics of the system under consideration corresponds to the behavior of a fuel element (FE) in a pulsed reactor and is related to the dynamic stability of the processes occurring in it.The FE dynamics is described by inhomogeneous linear differential equation of the fourth order with non-constant coefficients. Initial boundary conditions are not smooth since they correspond to the instant heating of the part of the FE surface exposed to neutron pulse radiation. The general solution of the homogeneous linear equation can be found using the concept of generalized functions expressed as a series expansion in terms of coordinate eigenfunctions dependent on p parameter. The p parameter is related with the FE mass and at some certain values results in bifurcation points of the boundary value problem for eigenfunctions. The partial solution can be found in several ways: using the Fourier transform, the method of Green's function, and in terms of series expansion by eigenfunctions.Eigenfunction expansion coefficients in an explicit form have been obtained and the numerical solution accuracy has been estimated for some important particular cases. The results of the obtained exact solutions appear to be very close to the results of the ANSYS numerical estimations. In the future the obtained exact solutions will be used as input data to simulate self-consistent system dynamics of more than 400 FE. Therefore, the advantage of the exact solution in practical use is that its calculation is much faster as compared with the finite element method done with ANSYS.

Optimal choice of indicators for timely assessment of the prognosis of COVID-19 in hospitalized patients

The aim of the study was to identify the indicators that are most significant for predicting the features of the course of COVID-19 in hospitalized patients.Materials and methods. 250 case histories of patients aged 18 to 86 years with COVID-19 hospitalized in the hospital of the city of Nukus, Republic of Uzbekistan, redesigned to provide care to patients with COVID-19 from July 1, 2020 to March 2022, were analyzed. Patients who had a wave–like course of the disease with the development of complications, an increase in the volume of lung damage, were included in the main group (62 patients, 3 of whom were extremely severe). The patients who had stable positive dynamics (188 people) formed a comparison group.Results and discussion. Among patients over 65 years of age, 36% had a complicated course, in the 45–65 age group — 29% (p>0.05), and among patients under 45 years of age — 13% (p<0.05). The main group was dominated by men (79%). Among hospitalized villagers, an increase in the severity of the condition was noted in 30% of cases, and among patients from the city of Nukus, such patients were 20% (p<0.05). The highest values of D-dimer, interleukin-6 and C-reactive protein were in both groups, significant differences between the groups were revealed in the levels of D-dimer and interleukin-6. Significant differences between the groups were found in the levels of D-dimer, interleukin-6, ferritin, ALT, AST, and urea.Conclusion. COVID-19 has become one of the most studied diseases to date, but aspects of the course of this disease in certain population groups are still not sufficiently investigated. The complicated, progressive course of COVID-19, according to the results of our study, was recorded in all age groups of the adult population, more often in men from rural areas aged over 45 years with chronic diseases. The main prognostic markers of the complicated and progressive course of COVID-19 should be considered high levels of D-dimer, interleukin-6 and ferritin.

Ballast stiffness estimation based on measurements during dynamic track stabilization

Ballast compaction with the Dynamic Track Stabilizer (DTS) is known to improve the lateral track resistance by increasing the stiffness of the ballast. This paper presents two approaches for estimating the strain dependent ballast shear modulus G based on measurements during dynamic track stabilization. One approach uses the Hardin equation with its enhancement for coarse-grained soils to estimate the small strain shear modulus for a given grain size distribution curve. Since different shear strains are induced on an observed sleeper (with fixed location) by a bypassing DTS, the measurement of ballast shear strains with accelerometers on the top and the bottom edge of the ballast layer yield shear modulus degradation curves G/Gmax. It is shown for data from a regular maintenance operation, that these shear modulus degradation curves are in accordance with previous research. For the second approach, a SDOF model for the track-ballast interaction under harmonic loading (caused by the dynamic track stabilizer) is developed. Influence lines are used to estimate the mass, the mass moment of inertia and the geometry of an equivalent machine foundation (with spring and dashpot coefficients according to the Hall analog). An optimization algorithm is used to fit the model response to the measured data from field tests with the DTS. The resulting shear moduli show plausible values for loose and compacted ballast conditions, which proves the potential of the presented method as a basis for a future system for Intelligent Compaction (IC) with the DTS.

Analyzing Emulsion Dynamics via Direct Visualization and Statistical Methodologies.

Analytical centrifugation is a powerful technique that leverages the principles of centrifugal force and optical detection to characterize emulsion droplets in a label-free and high-throughput manner. Other advantages include minimal sample preparation effort and compatibility with a wide range of emulsion formulations. However, the resulting data can be rather complex and, thus, difficult to fully understand and interpret. To tackle this, we developed two analytical methodologies that enable an easy and intuitive understanding of the data as well as an objective, quantitative analysis and validated them using six model emulsions employing different surfactants. Through their application, insights with unprecedented clarity into dynamic emulsion behavior, stability mechanisms, and emulsion-based processes can be gained, facilitating advancements in fields such as food science, pharmaceuticals, and materials engineering.

Command-filtered incremental backstepping attitude control of spacecraft with predefined-time stability

This paper investigates the predefined-time attitude tracking control problem within the theoretical framework of incremental dynamic inversion. The utilization of the Taylor series facilitates the transformation of the attitude control system into a discrete-time plant, with the control input expressed in an incremental form. Additionally, a novel predefined-time stable dynamics system is presented and incorporated into the disturbance observer designing process, serving the purpose of estimating lumped disturbance. It is also employed in a command filter design to approximate the derivatives of the virtual control law within a predefined time. Consequently, an incremental backstepping attitude tracking control scheme is further developed, integrating the proposed predefined-time disturbance observer to ensure the system's robustness and the predefined-time filter to address challenges related to “term explosion” and singularity problem. Rigorous Lyapunov analysis affirms that the attitude control system, when using the incremental backstepping controller, remains predefined-time stable. The effectiveness of the proposed control scheme is subsequently validated through numerical simulations.

Ab-Initio calculations on physical properties of Dirac semimetal AMgBi (A=K, Rb, Cs)

This study presents a comprehensive first-principles investigation of the structural, mechanical, vibrational, thermodynamic and electronic properties of AMgBi (A = K, Rb, Cs) compounds using Density Functional Theory. Also, the effect of substituting alkali atoms on the physical properties has been discussed. The tetragonal PbClF-type structure has been confirmed by the analysis and the results revealed good agreement between calculated and experimental lattice parameters for KMgBi. The mechanical properties have been investigated for the first time for RbMgBi and CsMgBi. The mechanical stability of the materials in the ground state has been confirmed through the use of obtained elastic constants. Furthermore, derived parameters from elastic constants such as bulk modulus, shear modulus, and Poisson's ratio indicated that the materials are brittle and exhibited anisotropic mechanical behavior due to their layered structure. This study conducts a detailed analysis of phonon modes, explores their connections to thermal and elastic properties, visualizes the movements of phonon modes at the gamma point, determines Born effective charges, and discusses LO/TO splitting, which is for the first time for RbMgBi and CsMgBi. Phonon dispersion calculations confirmed the dynamical stability of the compounds and revealed the presence of phonon band gaps, supporting their quasi-two-dimensional nature. Investigation of thermodynamic properties using the quasi-harmonic approximation has shown the temperature dependence of internal energy, Helmholtz free energy, specific heat, and entropy for the first time for all compounds. The materials exhibited relatively low thermal conductivity, following the order KMgBi > RbMgBi > CsMgBi. The calculated Grüneisen parameter values were found to be 1.42, 1.44, and 1.53 for KMgBi, RbMgBi, and CsMgBi, respectively, suggesting relatively weak anharmonicity within the materials.

First principles theoretical of designing Sandwich-like Metallic BP4 Monolayer as Anode for Alkali Metal-ion Batteries.

Phosphorene has been widely used as anode material for batteries. However, the huge volume change during charging and discharging process, the semiconductor properties, and the high open circuit voltage limit its application. Based on this, by introducing the electron-deficient boron atoms into blue phosphorene, we proposed a P-rich sandwich-like BP4 monolayer by density functional theory calculation and particle swarm optimization. The BP4 monolayer shows good thermodynamic and dynamic stability, as well as chemical stability in O2 atmosphere, mainly due to the strengthened P-P bond of the outer layer by the middle boron atoms adopting sp3 hybridization. According to the band structure, the BP4 monolayer shows metallic property, which is beneficial to electron conductivity. Furthermore, compared with blue phosphorene and black phosphorene, the P-rich BP4 monolayer shows higher theoretical capacity for Li, Na, and K of 1193.90, 1119.28, and 397.97 mA·h·g-1, respectively. The lattice constant of BP4 monolayer increases only 3.73 (Li), 2.52 (Na) after Li/Na fully adsorbed on the anode. More importantly, the wettability of BP4 monolayer in the electrolyte is comparable to that of graphene. These findings show that the stable sandwich-like BP4 monolayer has potential as a lightweight anode material.

Systematic investigation of physical properties of Mg3XO4 (X = Cr, Mn, Fe, Co, Ni); a computational approach

Material development is primarily dependent on their design and theoretical exploration. Density functional theory is a great tool to achieve this goal. Here, Mg3XO4 (X = Cr, Mn, Fe, Co, Ni) are considered in order to reveal their full characteristics using density functional theory. Mg3XO4 (X = Cr, Mn, Fe, Co, Ni) are investigated in terms of their structural, elastic, mechanical, thermodynamic, electronic, and dynamic properties. The formation energies for Mg3XO4 (X = Cr, Mn, Fe, Co, Ni) are found to be negative implying synthesisability and dynamic stability of these materials. The evolution of elastic constants of materials demonstrates that all materials satisfy the Born stability criterion, hence Mg3XO4 (X = Cr, Mn, Fe, Co, Ni) are mechanically stable. Several polycrystalline parameters are derived by using elastic constants and evaluated. All materials are found be brittle, hard (Vickers hardness) and magnetic. They exhibit some degree of anisotropy in Young/Shear modulus and Poisson’s ratio. The electronic band structures for Mg3CrO4, Mg3MnO4 and Mg3FeO4 indicated a semi-metallic nature whereas for Mg3CoO4 and Mg3NiO4 indicated metallic nature because both the majority and minority energy bands cut the Fermi level. The phonon modes are found to be in positive frequencies that confirms dynamical stability. The materials’ free energy, entropy, specific heat capacity, Debye and melting temperatures, minimum thermal conductivity and Grüneisen parameters are also obtained and discussed.

Mechanism of reinforced interfacial adhesion between steel slag and highly devulcanized waste rubber modified asphalt and its influence on the volume stability in steel slag asphalt mixture

The volume expansion risk of steel slag is a predominant challenge hindering its usage as an alternative aggregate in road pavements. In this study, the interfacial adhesion properties of base asphalt-basalt, base asphalt-steel slag, rubber modified asphalt (RMA) -basalt and RMA-steel slag were compared employing both experiment and molecular dynamics simulation. The volume stability and road performance of the asphalt mixture was also explored. The results showed that the residue rate of the RMA asphalt mixed with steel slag aggregates showed an increase from 87.5 % to 95.7 % compared to base asphalt after 100°C boiling water test. The interfacial adhesion between steel slag and asphalt surpasses that of basalt and asphalt, with the use of rubber modified asphalt further enhancing the adhesion with steel slag aggregates, as investigated through quantitative evaluation of interface adhesive work. The enhanced interaction between steel slag and RMA was primarily due to the integration of acidic functional groups from rubber chain with the alkaline active constituents (f-CaO) of steel slag aggregates, as confirmed by molecular dynamics simulations and accurate density functional theory calculations. Furthermore, the volume stability and road performance of the steel slag stone mastic asphalt were also greatly improved compared with basalt asphalt mixture. The dynamic average stability of RMA steel slag mixture was 9218 cycles/mm and the expansion rate of steel slag asphalt mixture under did not exceed 1.2 % after 216 hours water immersion. Therefore, this study provides an alternative aggregate for road pavement and a sustainable recycling strategy for the steel slag waste.

Dynamic behavior and stability control of skyrmionium in periodic PMA/damping gradient nanowires

Magnetic skyrmioniums—with a composite structure comprising two skyrmions with opposite topological charges, exhibit unique dynamic behaviors that are crucial for technological advancements and have application potential for high-density and nonvolatile memory. This study explores the impact of periodic perpendicular magnetic anisotropy (PMA) and damping gradients on skyrmioniums. Utilizing the object oriented micromagnetic framework for detailed simulations, the effective control and enhancement of the skyrmionium stability and mobility through the periodic modulation of PMA and damping gradients is demonstrated. The results demonstrate the dynamic behavior and stability control of skyrmioniums in periodic PMA/damping gradient nanowires. Moreover, the critical influence of the periodic gradient on the skyrmionium motion and stability is highlighted. The results present new avenues for developing advanced memory technologies, leveraging skyrmionium's unique nonlinear behaviors to improve the device performance and reliability.

Analysis of Transient Stability through a Novel Algorithm with Optimization under Contingency Conditions

Predicting the need for modeling and solutions is one of the largest difficulties in the electricity system. The static-constrained solution, which is not always powerful, is provided by the Gradient Method Power Flow (GMPF). Another benefit of using both dynamic and transient restrictions is that GMPF will increase transient stability against faults. The system is observed under contingency situations using the Dynamic Stability for Constrained Gradient Method Power Flow (DSCGMPF). The population optimization technique is the foundation of a recent algorithm called Training Learning Based Optimization (TLBO). The TLBO-based approach for obtaining DSCGMPF is implemented in this work. The total system losses and the cost of the individual generators have been optimized. Analysis of the stability limits under contingency conditions has been conducted as well. To illustrate the suggested approaches, a Standard 3 machine 5-bus system is simulated using the MATLAB 2022B platform.

The influence of acid rain on asphalt and its mixture performance, simulation and micro-mechanism exploration

Acid rain will destroy asphalt roads and affect human production and life. Therefore, this study has designed a new indoor simulated acid rain erosion test, and explored the effects of acid rain on the properties of 70# petroleum asphalt, SBS asphalt and their mixtures and the acid rain erosion mechanism from the micro and macro perspectives. In this paper, the influence of acid rain erosion on the microscopic properties of asphalt has been revealed through microscopic experiments. Through the combination with the basic performance test of asphalt, the effect of acid rain erosion on the conventional properties of asphalt was studied. The effects of acid rain on the properties of road asphalt mixtures were studied by Marshall immersion and high-temperature rutting tests. The results show that there is no obvious chemical reaction between the two kinds of asphalt after acid rain erosion, but the surface structure and morphology have changed significantly. There was a mass loss, the decreases of the softening point and ductility, and an increase of the penetration; the residual stability and high temperature resistance of both asphalt mixtures were reduced. In the worst case, the quality of petroleum asphalt was lost by 82.2%, the softening point and ductility decreased by 9.6% and 16.9% respectively, the penetration degree increased by 3.1% and the residual stability and dynamic stability of petroleum asphalt mixture decreased by 8.82% and 27.9% respectively. The mass loss of SBS asphalt was 82.5%, the softening point and ductility decreased by 5% and 3.3% respectively, the penetration increased by 2.6%, and the residual stability and dynamic stability of SBS asphalt mixture decreased by 4.82% and 25.4% respectively. In general, under the action of acid rain, the performance of 70# oil asphalt, SBS asphalt and their mixtures are affected to varying degrees. The specific performance is to destroy the original shape of asphalt, resulting in the loss of quality of asphalt, the reduction of deformation resistance, high temperature stability and low temperature stability of asphalt, weakening the high temperature stability and water stability of asphalt mixture, and leading to the decline of road performance.

Strategizing the industrial core of the national economy

Strategic provision of technological sovereignty and economic security for the long term are of the highest importance for any state. The availability of its own critically important technologies and high-tech production of products in priority economic areas increase the state’s resilience to external challenges and threats, as well as orient the economy towards the realization of national values and the interests of innovative development of emerging strategic opportunities. The formation of an industrial core as a vector for the implementation of a strategy to ensure technological sovereignty and economic security is a critically important strategic goal of Russia. At the national level, the need to strengthen and strategize the industrial core is confirmed, in which the industry should be based, not only ensuring stable dynamics of the national economy, but also stimulating its development focused on innovative priorities. However, the results of the strategic diagnosis indicate the existing imbalance in the sectoral structure of the national economy caused by premature processes of deindustrialization and primitivization of production capacities. The consequence of this is an increase in the negative impact of outdated technologies and organizational systems on the functioning and development of Russian industries. The study of the regulatory environment and methodological base of modern strategizing of priority industries in Russia conducted in this article indicates the presence of systemic errors in the preparation and implementation of strategic documents for long-term industrial development. In the article, the authors come to the conclusion about the imperfection and fragmentation of the applied methodology for the development and implementation of strategies for the development of industries, including errors of an essential, structural and methodological nature, or the lack of a methodology for strategizing in general. As a solution, the author proposes the use of industrial strategizing methodology, based on the theory of strategy and strategizing methodology of the Russian scientific school developed by the Center for Strategic Research at the Institute of Mathematical Research of Complex Systems and the Economic and Financial Strategy Department at Moscow School of Economics at Lomonosov Moscow State University, and has a number of advantages for the targeted development of industrial sectors and the formation of the industrial core of the national economy based on focusing on the search and implementation of strategic opportunities and the use of existing and newly created competitive advantages.

Network topology planning method for interconnecting large-scale renewable generators considering dynamic stability limitations

It is well-known that the connection of renewable generators (RGs) can result in stability issues. However, existing network topology planning methods primarily focus on economic factors and static safety constraints, often neglecting dynamic stability considerations. The aim of this study is to avoid the risk of oscillations at the planning stage, rather than addressing them through damping control after their occurrence. First, an index is proposed for numerically evaluating the impact of different network topologies on the stability of connecting RGs, concluding that parallel connection is the most stable among various topologies. Then, in scenarios involving multiple collection regions of RGs, a method is proposed to select the connection locations of RGs. This indicates that the distribution of wind generators should consider the transmission line length of collection nodes, rather than connecting all wind generators to one of them. Finally, the network topology planning steps from a dynamic stability perspective are summarized. It is meaningful to improve the stability of a power system connected by large-scale RGs without the need for additional damping control. Two case studies are conducted to validate the accuracy of the analyzed results, but in the future, more applicable examinations will be conducted.

Arthroscopic Dorsal Round-Block Capsulo-Ligamentoplasty for Dynamic Scapholunate Instability: An Anatomical Study and Case Series

Abstract Background Chronic dynamic scapholunate (SL) instability remains difficult to treat. Several treatment options exist. Purpose We propose an arthroscopic dorsal round-block capsulo-ligamentoplasty technique to treat dynamic scapholunate instability: a dorsal purse-string-like suture around the dorsal aspect of the proximal row, following the course of the dorsal intercarpal ligament (DICL). A Fiberwire suture travels between the radiocarpal and midcarpal space, piercing the attachments of the DICL on the triquetrum and of the scaphotrapezial ligament on the distal scaphoid. It reinforces the DICL and the dorso-capsuloscapholunate septum, also inducing a fibrotic healing. Moreover, it produces an extension lever correcting the scaphoid flexion/pronation. Compared with other capsulodesis techniques, the all-inside dorsal round-block capsulo-ligamentoplasty is theoretically likely to produce less stiffness, without additional damage to the SL complex. The wrist remains practically undamaged after surgery: no bone tunnels, bone anchors, or tendon grafts are required, thus enabling all possible secondary procedures. Data of a cadaveric study and case series illustrate the technique. Conclusion The arthroscopic dorsal round-block capsulo-ligamentoplasty can be considered to treat chronic dynamic scapholunate instability.