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A trigonometric beam theory (TBT) is developed for the bending analysis of laminated composite and sandwich beams considering the effect of transverse shear deformation. The axial displacement field uses trigonometric function in terms of thickness coordinate to include the effect of transverse shear deformation. The transverse displacement is considered as a sum of two partial displacements, the displacement due to bending and the displacement due to transverse shearing. Governing equations and boundary conditions are obtained by using the principle of virtual work. To demonstrate the validity of present theory it is applied to the bending analysis of laminated composite and sandwich beams. The numerical results of displacements and stresses obtained by using present theory are presented and compared with those of other trigonometric theories available in literature along with elasticity solution wherever possible.

Since the introduction of the implantable cardioverter defibrillator (ICD) by Michel Mirowski in the 1980's, these devices have become an important tenet in management of ventricular arrhythmias1. Numerous observational and randomized trials have demonstrated the superiority of this device over antiarrhythmic drugs in treating ventricular arrhythmias. The clinical implications of these trials are tremendous as sudden cardiac death (SCD) maybe the presenting symptom in these arrhythmias. It is estimated that in the United States alone around 350,000 deaths occur each year due to SCD alone2 . As resuscitation is seldom successful in the community, methods to identify and appropriately treat such patients alone can prevent these events. However, the public health impact of this approach is tremendous, as the ICD is extremely expensive and is out of reach for many individuals. Moreover, not all patients with structural heart disease and ventricular arrhythmias have a malignant outcome. Thus efforts to appropriately stratify patients according to their risk profile and accordingly advocate ICD implant has important fiscal implications for the state with meager health resources, especially in those patients in whom survival benefit with the ICD is modest.

The properties of unidirectional (UD) composites has been investigated by analyzing their elastic and strength characteristics under shear loading. The UD fiber‐reinforced polymer (FRP) composites usually consist of fibers randomly dispersed throughout the cross‐section in the transverse direction which is generally not accounted for. A micromechanical model based on finite element analysis (FEA) approach is utilized here to examine these properties. The study begins by identifying micro scale unit cells or repetitive unit cells (RUCs) at the micro scale, as well as representative volume elements (RVEs). The distribution of fiber volume fraction (Vf) varies among various micro scale unit cells positioned in the transverse cross‐section. The elastic properties and strength are estimated by considering the properties of the matrix and fibers, and the configuration of micro scale unit cells, which feature a fiber arrangement which is categorized as hexagonal and varying Vf at different locations (from 0.35 to 0.75). However, the overall Vf for the UD composite remains constant at 0.65. Studies are also carried out with the random distribution of fibers at micro scale unit cells. The findings reveal that the random distribution of fibers significantly impacts the shear behavior of the composite. This investigation provides valuable insights into how the mechanical properties of the UD composite are subjective by the distribution of fiber, thereby contributing to the design and development of this light weight high‐performance material. Highlights: Elastic and strength analysis of UD composites is presented.Emphasis is on fiber dispersion in transverse plane.Microscale unit cells, RUCs and RVE are identified.Studies are carried out based on micromechanical model.Influence of fiber distribution on shear behavior is investigated. [ABSTRACT FROM AUTHOR]

The disorder known as hyperdontia is characterized by an excess of teeth or teeth that appear to be added to the normal amount of teeth. With a frequency ranging from 0.1% to 3.9% in permanent dentition and from 0.3% to 1.8% in deciduous dentition, it affects males more often than women. Since children’s cognitive abilities are still developing in comparison to adults’, children freely communicate their worry and anxiety and frequently exhibit uncooperative behavior patterns while undergoing treatment. A7‑year‑old child who was emotionally immature reported with a principal complaint of missing tooth in his left upper front tooth area for 2 years. Cone‑beam computed tomography was advised to verify location and structural interaction with neighboring structures. Due to his lack of emotional sensitivity and cooperation with others, we planned the surgical extraction under general anesthesia. In the present case, it was deemed preferable to wait for a spontaneous eruption, and the patient was observed for a month on a regular basis. [ABSTRACT FROM AUTHOR]

This article proposed an off-board bidirectional battery charger for electric vehicles (EVs) that have been designed to perform various modes of operation of EVs like grid-to-vehicle (G2V) and vehicle-to-grid (V2G) while improving the grid power quality (PQ). During the charging process, the charger operates in the G2V mode. In this mode, power flows from the utility grid to the EV, ensuring a smooth and efficient transfer, which has the ability to maintain a sinusoidal grid current waveform and a unity power factor throughout the operation. This not only ensures efficient power transfer but also minimizes disruptions and distortions in the grid. On the other side of the operational spectrum lies the discharging phase, governed by the V2G mode. This mode allows the charger to deliver power from the EV's batteries back to the utility grid. This capability is a significant step toward establishing a two-way relationship between EVs and the grid, enabling EVs to act as energy reservoirs and support grid stability during peak demand or emergencies. This paper presents the proposed adaptive direct power control (ADPC) theory for the proposed electric vehicle charger (EVC), which consists of a grid-side converter and an EV side converter. The proposed control algorithm on both sides of the converters plays a significant role in various operating modes. The ADPC employs a control strategy referred to as the second-order generalized integrator to estimate the actual synchronizing voltage templates specifically designed for single-phase grid-side converters. Consequently, the appropriate current reference used by the charger is to ensure that the power factor remains unity throughout various operating modes. Similarly, for the EV side converter, the integration of the power delivery error further enhances steady-state responses with the proposed ADPC by generating actual phase shifted pulses for the DAB. The overall performance under similar conditions is studied with virtual direct power control to further check the robustness of the proposed ADPC. The adopted topology and control technique further implemented in the prototype of an off-board EVC to verify the various operating conditions to demonstrate its effectiveness and justified as per the IEEE 519-2022 standard. [ABSTRACT FROM AUTHOR]

The power quality of the grid-coupled photovoltaic system (GCPVS) is enhanced using a control scheme developed by employing a robust generalized soft-root-sign (GSRS) adaptive filter. Power quality (PQ) deterioration issues are common in the distribution grid due to the mix of irregular loads. The GSRS control scheme mitigates harmonics, compensates load unbalances, achieves unity power factor at the grid, and compensates load reactive power, thus leading to balanced sinusoidal currents at the grid side. The GSRS algorithm utilizes a soft-root-sign cost function to achieve less steady-state misalignment while estimating magnitudes of fundamental frequency load current components for PQ improvement. The designed single-stage GCPVS performs smooth power flow between local loads and the grid without necessitating an energy storage system. The control scheme initially meets load demand and then sends any surplus power to the grid. However, if the generated PV power falls below the load demand due to environmental conditions, the additional power for the load is drawn from the grid. Moreover, voltage source converter used in the GCPVS also provides the functionality of DSTATCOM, thus avoiding the usage of additional equipment. The proposed GSRS control scheme and the GCPVS are modeled in MATLAB/Simulink. A laboratory-designed experimental setup is used to carry out the experimental validation of the GSRS control scheme and found to be performing satisfactorily. The behavior of GCPVS is verified during steady-state and dynamic conditions. The GCPVS performance is verified with the standard IEEE-519-2022, and a comparison of the GSRS algorithm with other filtering algorithms is provided. [ABSTRACT FROM AUTHOR]

Summary: With the increase in the penetration level of renewables into the grid, the virtual synchronous generator (VSG) concept has emerged as an attractive solution for controlling grid‐tied inverters. The variation in reactive power also affects the real power of the system as well. To address the voltage variations and phase angle variations occurring because of the energy storage elements, the control of the reactive power loop (RPL) is important. Also, it is used to maintain voltage regulation and improve the power factor of the VSG system. This paper focuses on the damping of oscillations occurring because of load variation by proper adjustment of the rotational inertia, damping coefficient, droop coefficient, and regulatory coefficient of reactive power with a proposed adaptive control strategy. Small‐signal analysis of the active and reactive power and point of common coupling (PCC) have been derived, and the detailed dynamic performances are analyzed. The influences of parameters perturbation on PCC voltage and reactive power were investigated. Furthermore, adaptive control includes optimizing dynamic indexes such as rise time, delay time, and response settling time. Finally, the performance and improvement in the results of VSG with and without adaptive control are compared. [ABSTRACT FROM AUTHOR]

Summary: This article presents an improved least mean square (LMS) algorithm‐based control approach for a three‐phase grid interfaced solar photovoltaic (GISPV) system for smart building applications. The SPV is primarily utilized to supply household loads, and the absence or intermittency of SPV is curbed by utilizing power from the grid. The majority of household loads are nonlinear loads that affect the grid power quality (PQ). However, the effects of both linear and nonlinear loads on grid PQ have been analyzed in this article. This article proposes a Gaussian Kernel function‐based normalized LMS (GKNLMS) algorithm to calculate the active peak weight component of the load current, thereby utilizing it to obtain a sinusoidal reference current. Considering a higher step size and utilizing the Gaussian Kernel function for reduced mean square error (MSE) improves both the convergence rate and accuracy of estimation in the conventional LMS. The proposed control technique effectively addresses system anomalies caused by dynamic solar irradiance, load variation, and unbalanced loading conditions. Furthermore, the system response with the GKNLMS algorithm is assessed in MATLAB/Simulink and validated by developing a laboratory setup of the system for experimentation. [ABSTRACT FROM AUTHOR]

Dental stains are pigmented deposits that can be intrinsic or extrinsic in origin and are seen on the surface of the teeth. Discoloration of teeth can be due to developmental defects, traumatic injuries, or the intake of several medications. Extrinsic stains create discoloration outside the tooth surface and lay on the surface or in the acquired pellicle, whereas stains within dentin or intrinsic discoloration sometimes come from pulpal or systemic origin. To plan a specific treatment approach and its associated result, it is important to identify the etiologic cause that is creating the stain, in an attempt to provide esthetic treatment for the same. This case report describes the successful management of intrinsic staining of anterior teeth in a 10-year-old girl. The treatment plan included esthetic rehabilitation using composite veneer. The fluoride-releasing composite used provided an acceptable color match and exceptional handling properties and was relatively easy to maintain with its antiplaque effect. This case also represents a unique histopathological finding from ground sections of a retained extracted deciduous tooth. [ABSTRACT FROM AUTHOR]