Circular Box Research Articles

On the two-dimensional harmonic oscillator with an electric field confined to a circular box

Abstract We revisit the quantum-mechanical two-dimensional harmonic oscillator with an electric field confined to a circular box of impenetrable walls. In order to obtain the energy spectrum we resort to the Rayleigh-Ritz method with polynomial and Gaussian basis sets. We compare present results with those derived recently by other authors. We discuss the limits of large and small box radius and also do some calculations with perturbation theory.

Laboratory Study of Interface Friction between Sand and Steel Surfaces

Abstract In this study, results have been reported from a series of laboratory tests to determine the interface friction angle of steel surfaces with sand through modified direct shear testing. For completion, steel surfaces with different surface geometry to replicate the roughness have been slid against various sands compacted at different relative densities under both dry and wet conditions. The standard square shape direct shear box has been modified into circular and rectangular boxes to sufficiently enhance the contact area and to subsequently quantify its effect on interface friction angle. A mild steel interface of smooth and rough texture with a groove depth of 0.2 mm and tipping at an angle of 90° has been used in this study. The analysis of results revealed that the interface friction angles obtained from the standard direct shear box agree closely with those obtained from both modified rectangular and circular shear boxes. However, the ratio of the interface friction angle from the modified apparatus and soil’s angle of internal friction significantly depends upon the roughness of the surface in contact with the sand, its median particle size, and is independent of the effects of box size, soil’s relative density, and dry or wet condition. A comparison between existing well-accepted guidelines and current observations has been presented for use by the practicing engineers dealing with soil-structure interaction.

In-Plane Stability Analysis of Circular Box Arches with Sinusoidal Corrugated Webs

In-Plane Stability Analysis of Circular Box Arches with Sinusoidal Corrugated Webs

Spatial dispersion of post-feeding larvae of forensically important flies: Implications for medicolegal investigation

IntroductionCalliphoridae flies allow estimating the postmortem interval (PMI), as they are the first to arrive at a decomposing body. Its larvae feed on the carcass and then move away to pupate (post-feeding dispersal). Since the environment alters the physiology and behaviour of insects, the dispersal of larvae and the final location of pupae could be related to the place where the carcass is deposited. The aim of this work was to study the dispersal of post-feeding larvae in relation to environmental variables in northern Patagonia. Materials and methodsThe distribution of pupae in response to different illumination, temperature, and soil inclination conditions was evaluated. A circular box divided into quadrants was used for each treatment and a control. Post-feeding larvae were placed in the centre of each box, allowing them to disperse until they pupate. Differences in the number of pupae collected in each quadrant were evaluated by ×2 tests. ResultsAccording to the control, the dispersion of post-feeding larvae occurs randomly (p=.098). Regarding temperature, the larvae eluded the heat source (p<.01). The inclination treatments showed that larvae avoided the raised surface (p<.01). Concerning illumination conditions, no trend was observed (p=.41). ConclusionsKnowing the dispersal patterns of larvae, considering environmental variables, reduces search times and let infers the sectors with the highest probability of finding pupae. In this way, it is likely to estimate a more precise PMI in the framework of medico-legal investigations.

ENERGY ABSORPTION AND DEFORMATION PATTERN OF CIRCULAR HYBRID CRASH BOX SUBJECTED TO FRONTAL LOAD

Crashworthiness is related to the ability of a structure to reduce the effects of a collision risk of injury to passengers and the risk of damage to vital parts of the vehicle. Geometry design of crash box is one important parameter to increase crashworthiness performance by increasing energy absorption through progressive deformation. In previous studies, circular crash box absorbed higher energy than other geometry design. Besides that, another parameter is material design. In other studies, the hybrid model absorbs more energy with a less increasing mass. Hybrid crash box combine low-density and high-strength of composite materials with aluminium materials are affordable and ductile to increase energy absorption. This study aims to develop circular hybrid crash box by variating fibre orientation angle of composite and hybrid material configuration. Crash box design is investigated by using computer simulation with ANSYS Workbench. The crash box materials used are Carbon Toray T300 – Epoxy Resin (CCE) and Aluminium Alloy 6063 (AA6063). Eight of circular hybrid crash box models subjected to axial loading with a speed of 10 m/s. The frontal loading is modelled by setting impactor with mass of 100 kg. Energy absorption and deformation pattern were observed. The results showed that the Al-Ko45 model with orientation angle [45/- 45,-45/45]5 and hybrid material configuration of composite inside has highest energy absorption of 8.24 kJ. The deformation pattern in the aluminium part is mixed of concertina at the first stage then continued by diamond pattern, The deformation composite part is dominated by local buckling with transverse shearing. The fractions or folds of composite is functions like foam-filled filling folds of aluminium deformation to initiate progressive crushing folding that can increase the crashworthiness characteristic as the energy absorption.

Out-of-Plane Stability Analysis of the Circular Box Arch with Sinusoidal Corrugated Webs

This paper presents an arch structure called the circular box arch with sinusoidal corrugated webs (CBASCW). This study investigates the out-of-plane elastic buckling behavior and elastoplastic stability capacity of the arch through a combined approach of theoretical derivation and finite element simulation. The section stiffness of the arch, including flexural stiffness, shear stiffness, and torsional stiffness, is achieved through theoretical derivation. Additionally, the elastic buckling load in both pure compression and pure bending states is derived. A simplified model is also introduced, which can conveniently simulate the internal force and deformation of the arch. The elastoplastic instability mechanism and failure mode are studied under various loading conditions, including uniform radial load, end bending moment, vertical load uniformly distributed in full-span, and vertical load uniformly distributed in half-span. Furthermore, the stability curves of the arch under conditions of pure compression and pure bending are graphed by incorporating stability coefficient and regularized slenderness ratio. According to the simulation results obtained from the simplified model and the analysis of stability curves, a design formula for stability capacity is proposed.

Dispersión espacial de larvas postalimentarias de moscas de importancia forense: implicaciones para la investigación médico-legal

IntroductionCalliphoridae flies allow estimating the post-mortem interval, as they are the first to arrive at a decomposing body. Its larvae feed on the carcass and then move away to pupate (post-feeding dispersal). Since the environment alters the physiology and behavior of insects, the dispersal of larvae and the final location of pupae could be related to the place where the carcass is deposited. The aim of this work was to study the dispersal of post-feeding larvae in relation to environmental variables in northern Patagonia. Materials and methodsThe distribution of pupae in response to different illumination, temperature and soil inclination conditions was evaluated. A circular box divided into quadrants was used for each treatment and a control. Post-feeding larvae were placed in the center of each box, allowing them to disperse until they pupate. Differences in the number of pupae collected in each quadrant were evaluated by X2 tests. ResultsAccording to the control, the dispersion of post-feeding larvae occurs randomly (p = 0.098). Regarding temperature, the larvae eluded the heat source (p < 0.01). The inclination treatments showed that larvae avoided the raised surface (p < 0.01). Concerning illumination conditions, no trend was observed (p = 0.41). ConclusionsKnowing the dispersal patterns of larvae, considering environmental variables, reduces search times and let infers the sectors with the highest probability of finding pupae. In this way, it is likely to estimate a more precise post-mortem interval in the framework of medico-legal investigations.

YOLO Network with a Circular Bounding Box to Classify the Flowering Degree of Chrysanthemum

Detecting objects in digital images is challenging in computer vision, traditionally requiring manual threshold selection. However, object detection has improved significantly with convolutional neural networks (CNNs), and other advanced algorithms, like region-based convolutional neural networks (R-CNNs) and you only look once (YOLO). Deep learning methods have various applications in agriculture, including detecting pests, diseases, and fruit quality. We propose a lightweight YOLOv4-Tiny-based object detection system with a circular bounding box to accurately determine chrysanthemum flower harvest time. The proposed network in this study uses a circular bounding box to accurately classify the degree of chrysanthemums blooming and detect circular objects effectively, showing better results than the network with the traditional rectangular bounding box. The proposed network has excellent scalability and can be applied to recognize general objects in a circular form.

Polygons of quantized vortices in Bose-Einstein condensates with a circular trap.

We consider a disk-shaped cold atom Bose-Einstein condensate with repulsive atom-atom interactions within a circular trap, described by a two-dimensional time-dependent Gross-Pitaevskii equationwith cubic nonlinearity and a circular box potential. In this setup, we discuss the existence of a type of stationary nonlinear waves with propagation-invariant density profiles, consisting of vortices located at the vertices of a regular polygon with or without an antivortex at its center. These polygons rotate around the center of the system and we provide approximate expressions for their angular velocity. For any size of the trap, we find a unique regular polygon solution that is static and is seemingly stable for long evolutions. It consists of a triangle of vortices with unit charge placed around a singly charged antivortex, with the size of the triangle fixed by the cancellation of competing effects on its rotation. There exist other geometries with discrete rotational symmetry that yield static solutions, even if they turn out to be unstable. By numerically integrating in real time the Gross-Pitaevskii equation, we compute the evolution of the vortex structures and discuss their stability and the fate of the instabilities that can unravel the regular polygon configurations. Such instabilities can be driven by the instability of the vortices themselves, by vortex-antivortex annihilation or by the eventual breaking of the symmetry due to the motion of the vortices.

Energy absorption optimisation of an origami-shaped crash box under axial loading

The crease line formed in an origami-shaped crash box (OSCB) acts as a geometric imperfection and mode inducer. Such geometric imperfections make it possible to protect occupants by lowering the peak force in the event of a collision. The OSCB also shows desirable performance as a crashworthy structure by inducing a collapsing mode with excellent energy absorption. There are many studies on crash boxes with origami patterns applied, but few studies on performance optimisation. This article describes the structural optimisation of an OSCB to maximise the specific energy absorption (SEA) by setting the corner length c and module length l as design variables. Numerical and experimental investigations of the crashworthiness performance were conducted by comparing the optimised OSCB to a circular crash box (CCB), which is known to have the best SEA among straight tubes. The numerical and experimental results were in good agreement, with the optimised OSCB collapsing into the diamond mode. The results of the numerical comparison showed that the SEA and the crush force efficiency (CFE) of the optimised OSCB were increased by 5.94% and 115.58%, respectively. However, in a quasi-static axial crushing experiment, the SEA of the optimised OSCB was 10% lower than that of the CCB, and the CFE was increased by 88.5%. The optimised OSCB in this study displayed an improvement in the SEA compared to the reference OSCB, as well as a reduction in the difference from the CCB, indicating high maintenance performance of the CFE.

YOLO Network Optimization With a Single Circular Bounding Box for Detecting Defective Cigarettes

YOLO Network Optimization With a Single Circular Bounding Box for Detecting Defective Cigarettes

Interpretation of constant suction direct shear test

Constant suction direct shear test enables the understanding of the failure mechanism in rainfallinduced landslides. It can be conducted using a conventional direct shear apparatus with some modifications. The constant suction direct shear test is carried out in two stages. In the first stage, the unsaturated soil specimen is consolidated to the target net normal stress and matric suction then sheared in the second stage. Matric suction is usually controlled using the axis-translation principle. It is commonly observed that the shear stress of an unsaturated soil sheared in the direct shear shows a strain-hardening behaviour at large displacements making the determination of the failure stress difficult. Hence, the objective of this study is to critically examine the constant suction direct shear tests and the analysis of the test results to obtain the shear strength parameters for unsaturated soils. Constant suction direct shear test data were collated from the literature. It was found that the interpretation of the direct shear test has two inconsistencies: (1) taking failure shear stress at arbitrary displacement strain or limit, dependent on the size of the direct shear apparatus, and (2) correcting only shear stress for contact area. The effect of these two consequences on the interpretation of the direct shear test range from negligible to significant. The study shows that arbitrary determination of failure shear stress can be resolved by plotting the direct shear test results using a stresspath plot. The effects of area correction are shown to be almost negligible for small horizontal displacements of less than 2 mm for both square and circular shear boxes. A more consistent interpretation of the constant suction direct shear test is demonstrated where both these inconsistencies are considered.

A Deep Neural Network Based on Circular Representation for Target Detection

Convolutional neural network (CNN) model based on deep learning has excellent performance for target detection. However, the detection effect is poor when the object is circular or tubular because most of the existing object detection methods are based on the traditional rectangular box to detect and recognize objects. To solve the problem, we propose the circular representation structure and RepVGG module on the basis of CenterNet and expand the network prediction structure, thus proposing a high-precision and high-efficiency lightweight circular object detection method RebarDet. Specifically, circular tubular type objects will be optimized by replacing the traditional rectangular box with a circular box. Second, we improve the resolution of the network feature map and the upper limit of the number of objects detected in a single detect to achieve the expansion of the network prediction structure, optimized for the dense phenomenon that often occurs in circular tubular objects. Finally, the multibranch topology of RepVGG is introduced to sum the feature information extracted by different convolution modules, which improves the ability of the convolution module to extract information. We conducted extensive experiments on rebar datasets and used AB-Score as a new evaluation method to evaluate RebarDet. The experimental results show that RebarDet can achieve a detection accuracy of up to 0.8114 and a model inference speed of 6.9 fps while maintaining a moderate amount of parameters, which is superior to other mainstream object detection models and verifies the effectiveness of our proposed method. At the same time, RebarDet’s high precision detection of round tubular objects facilitates enterprise intelligent manufacturing processes.

Dynamics of Two Quantized Vortices Belonging to Different Components of Binary Bose–Einstein Condensates in a Circular Box Potential

This study aims to research on dynamics of two quantized vortices in miscible two-component Bose--Einstein condensates, trapped by a circular box potential by using the Gross--Pitaevskii equation. We consider a situation in which two vortices belong to different components and they are initially close. Their dynamics are significantly different from those of a vortex pair in a single-component condensate. When two vortices are initially co-located, they are split by dynamical instability or remain co-located depending on their intercomponent interaction. If the two split vortices have the same sign of circulation, they rotate around each other. Then, the angular velocity can be given as a function of the distance between two vortices, which is understood through the equations of motion and their interaction. If the circulations of two close vortices have different signs, however, they move in the same direction initially, then overlap during the dynamics. This subsequent overlap can be categorized into two types based on the initial distance between them. The mechanism of this overlapping can be understood from the interaction between the vortex and its image vortex, which makes the two vortices close to each other even if the intrinsic interaction between them is repulsive.

Formation of the quasi-planar B56 boron cluster: topological path from B12 and disk aromaticity.

Formation and stability of the B56 boron cluster were investigated using a topological approach and the disk aromaticity model. An extensive global energy minimum search for the B56 system which was carried out by means of the Mexican Enhanced Genetic Algorithm (MEGA) in conjunction with density functional theory computations, confirms a quasi-planar structure as its energetically most stable isomer. Such a structural motif is derived by applying a topological leapfrog operation to a B12 form. Its high thermodynamic stability can be explained by the disk aromaticity model in which the delocalization of its π orbitals can be assigned to the levels of a particle in a circular box with the [(1σ)2 (1π)4 (1δ)4 (1φ)4 (2σ)2 (1γ)4 (2π)4 (2δ)4 (1η)4 (2φ)4 (1θ)2] electronic configuration. This π delocalization is confirmed by other delocalization indices. While the B56 has a similar electron delocalization to that of the quasi-planar B50, they have opposite magnetic ring current properties because of the symmetry selection rules of their HOMO-LUMO electronic transitions. The π delocalization in the boron clusters is larger at long distances as compared to carbon clusters at similar sizes, but such a trend is reversed at shorter distances.

Structural Behavior of Reinforced Concrete Horizontally Curved Box Beam with Opening

This work is dedicated to survey the structural reinforced concrete's behavior horizontally curved box beams with and without opening. Seven horizontally circular box beams were examined in the experimental work, one without opening, three with vertical opening and three with transverse opening. The test program includes the main variables; direction of opening, location of opening through profile of curved beams (effect of combination of internal forces). The beams were tested as a continuous beam with two spans, each span represents a quarter circle and under the action of two point loads each load located at top face of midspan of beam. The findings indicate that the ultimate load capacity was decreased for all specimens (CB2.V37, CB3.V60, CB4.V82, CB5.T37, CB6.T60 and CB7.T82) by about (5, 11.5, 1.5,1.5, 46.4 and 18.66%) respectively, compared to the control CB1. When compared with the control specimen CB1, all specimens were indicating an increase in Service deformations in terms of deflection and twisting angle at midspan of the circular beams. The ductility was deteriorated for all specimens with opening (CB2.V37, CB3.V60, CB4.V82, CB5.T37, CB6.T60 and CB7.T82), as a percent was about (13.88, 15.3, 19.62, 0.5, 0.5 and 13.88%) respectively, compared with that of control specimen CB1. As a result, generally, a clear degradation with different percentages in overall structural behavior of box beams horizontally curved containing opening according to the location and direction of openings, in this study the transverse openings at 60°, where the opening under the combined maximum (shear and torsion) was led to a catastrophic decrease in the structural performance of horizontally curved box beam.

Short communication: Sodium chloride levels in pacu (Piaractus mesopotamicus) fingerling feeds free of fish meal

Aim of study: To evaluate the effects of increasing NaCl levels on the zootechnical performance of pacu fingerling. Area of study: The experiments were conducted at the Aquatic Organism Production and Reproduction Systems Laboratory belonging to the Federal University of Paraná (UFPR), in the Palotina Sector, Paraná Estate, Brazil. Material and methods: Seven hundred and fifty fingerlings with an average weight of 3.41 ± 0.09 g were distributed in circular boxes, in a completely randomized design consisting of six treatments and five replications. Treatments comprised soybean- and maize-based diets containing increasing levels of NaCl (0.00, 0.25, 0.50, 0.75, 1.00 and 1.25%). The experiments were conducted for 50 days. At the end of the experimental period the fish were fasted for 24 hours, anesthetized, weighed and measured to calculate zootechnical performances. Performance data were subjected to an analysis of variance followed by Tukey’s test when significant differences were found between the means (p&lt;0.05). Main results: The influence (p&lt;0.05) of dietary NaCl levels on final weight, feed intake, apparent feed conversion, specific growth rate, average weight gain, clean trunk production, head carcass yield, headless carcass yield, feed intake and survival was assessed. The results indicate that non-salt treated fingerlings along with the 0.25% salt inclusion treatment led to better feed use, as evidenced by apparent feed conversions of 1.64 and 2.02, respectively. Research highlights: The inclusion of NaCl in pacu fingerling soybean and maize-based diets is not recommended.

Improving Packaging Logistics System: A Study Case of Camembert Cheese

cheese using the packaging evaluation method and to propose suggestions to improve the efficiency of packaging logistics that would impact the efficiency of the entire supply chain. We engage all supply chain actors for evaluating the packaging features. The first packaging is not convenient as its weight and cost are quite high for cheese, the secondary packaging is deemed less efficient, whilst the tertiary packaging is not optimal in terms of traceability. Speaking of cost, environmental impacts, especially impact on other features in the supply chain, we propose solutions to replace the circular wooden box of the cheese with a cardboard box with a round shape. Then, only the cardboard trays will be used as secondary packaging all along the supply chain. These combined solutions reduce the handling work, the packaging material cost and provide more convenience for all actors.

Feasibility study on stereotactic radiotherapy for total pulmonary vein isolation in a canine model

We tested the feasibility of pulmonary vein (PV) and left atrial (LA) posterior wall isolation using non-invasive stereotactic ablative body radiotherapy (SABR) and investigated pathological changes in irradiated lesions in a canine model. Seven male Mongrel dogs received single-fraction 33 Gy SABR. We designed the en-bloc circular target of total PVs and LA posterior wall to avoid the esophagus. The circular box lesion included the LA roof and ridge, low posterior wall, and posterior interatrial septum. At 6 weeks or 4 months post-SABR, electrical isolation of the SABR lesion was confirmed using LA posterior wall pacing, and histopathological review was performed. Electrical isolation of all PVs and the LA posterior wall was achieved in three of five dogs in the 4-month group. There was one target failure and one sudden death at 15 weeks. Although two dogs in the 6-week group failed to achieve electrical lesion isolation, the irradiated atrial myocardium showed diffuse hemorrhage with inflammatory cell infiltration. In successfully isolated 4-month model dogs, we observed transmural fibrotic scarring with extensive fibrosis on irradiated atrial tissue. The findings suggest that this novel circular box-design radiotherapy technique using SABR could be applied to humans after further studies are conducted to confirm safety.

A detection algorithm for cherry fruits based on the improved YOLO-v4 model

"Digital" agriculture is rapidly affecting the value of agricultural output. Robotic picking of the ripe agricultural product enables accurate and rapid picking, making agricultural harvesting intelligent. How to increase product output has also become a challenge for digital agriculture. During the cherry growth process, realizing the rapid and accurate detection of cherry fruits is the key to the development of cherry fruits in digital agriculture. Due to the inaccurate detection of cherry fruits, environmental problems such as shading have become the biggest challenge for cherry fruit detection. This paper proposes an improved YOLO-V4 deep learning algorithm to detect cherry fruits. This model is suitable for cherry fruits with a small volume. It is proposed to increase the network based on the YOLO-V4 backbone network CSPDarknet53 network, combined with DenseNet The density between layers, the a priori box in the YOLO-V4 model, is changed to a circular marker box that fits the shape of the cherry fruit. Based on the improved YOLO-V4 model, the feature extraction is enhanced, the network structure is deepened, and the detection speed is improved. To verify the effectiveness of this method, different deep learning algorithms of YOLO-V3, YOLO-V3-dense and YOLO-V4 are compared. The results show that the mAP (average accuracy) value obtained by using the improved YOLO-V4 model (YOLO-V4-dense) network in this paper is 0.15 higher than that of yolov4. In actual orchard applications, cherries with different ripeness of cherries in the same area can be detected, and the fruits with larger ripeness differences can be artificially intervened, and finally, the yield of cherry fruits can be increased.