Rectangular Cuts Research Articles

Particle identification with machine learning from incomplete data in the ALICE experiment

The ALICE experiment at the LHC measures properties of the strongly interacting matter formed in ultrarelativistic heavy-ion collisions. Such studies require accurate particle identification (PID). ALICE provides PID information via several detectors for particles with momentum from about 100 MeV/c up to 20 GeV/c. Traditionally, particles are selected with rectangular cuts. A much better performance can be achieved with machine learning (ML) methods. Our solution uses multiple neural networks (NN) serving as binary classifiers. Moreover, we extended our particle classifier with Feature Set Embedding and attention in order to train on data with incomplete samples. We also present the integration of the ML project with the ALICE analysis software, and we discuss domain adaptation, the ML technique needed to transfer the knowledge between simulated and real experimental data.

Simulation of CuO-water nanofluid flow for cooling of solar photovoltaic module

The importance of studying photovoltaic thermal (PVT) systems is underscored by their potential to harness both solar thermal and photovoltaic energy simultaneously, making them a promising avenue for sustainable power generation. The integration of a PVT system allows for enhanced energy conversion and utilization of available resources. In the context of the broader field of renewable energy, understanding and optimizing PVT systems contribute to the development of efficient and environmentally friendly power generation solutions. The introduction of CuO nanoparticles proves beneficial, contributing to an overall improvement in system performance. Throughout this exploration, the aim is to provide insights into the intricate dynamics of PVT systems under varying conditions, emphasizing the impact of key parameters on system efficiency and performance. Examining PVT systems, this study focuses on a rectangular duct equipped with a turbulator featuring rectangular cuts. The simulation considers the flow of CuO-H2O within the channel and accounts for pure conduction within the layers, employing the finite volume method with a validation test for accuracy. The mesh size has been optimized for computational efficiency. In this context, the study investigates variations in cell temperature (T PV) and efficiency components (electrical (η PV), thermal (η th), overall (η PVT)) concerning key variables: wind speed (V w (0.4, 1, 1.4 m/s)), incident irradiation (G (730, 830, 930 W/m2)), inlet velocity (0.08, 0.1, 0.12 m/s), volume fraction of CuO (ϕ = 0, 0.018). Introducing the turbulator improves T PV uniformity by about 20.43%. With increased incident irradiation in the presence of the turbulator, η PV, η th, and η PVT values enhance by approximately 1.02%, 8.18%, and 4.99%, respectively. Specifically, at G = 930 W/m2, the turbulator installation leads to a 4.35% increase in η PVT. However, certain variables demonstrate contrasting effects. Increased wind speed results in a 3.63% decrease in η PVT for tubes equipped with a turbulator. Conversely, intensifying the inlet velocity leads to an augmentation of η PVT by around 3.19%, coupled with a notable 16.34% improvement in the uniformity of T PV.

Experimental & numerical investigation of heat transfer using twisted tapes with rectangular cuts

The current work focuses on using rectangular inserts with water as the working fluid to investigate heat transfer experimentally and numerically in a horizontal circular tube [10]. The study considers variations in the number of rectangular slots within the same strip. The tube has dimensions of 0.0266 m diameter. Twisted tapes, featuring rectangular cuts, are constructed from a 3 mm thick Stainless-steel strip with a length of 1035 mm. For experimentation, two different types of rectangular inserts were considered: one with nine cuts and the other with eighteen cuts. The dimensions of the cuts were as follows: length of 1000 mm, width of 13 mm, depth of cut 8 mm, and thickness 3 mm. The heat flux applied to the horizontal tube was steady and uniform. The range of the Reynolds number was 9,000–19,000. A plain tube without an insert was used to compare the results. The horizontal tube along with rectangular insert was modelled in Ansys Fluent software with fine meshing and analysed. Initially, CFD analysis was done for plain tube with and without insert, and results have been verified by comparison with experimental values. A comprehensive comparison is established, evaluating different heat transfer parameters, including convective heat transfer coefficient (h), heat transfer rate (q), and Nusselt number (Nu).

Enhancing the stretchability of two-dimensional materials through kirigami: a molecular dynamics study on tungsten disulfide.

In recent years, the 'kirigami' technique has gained significant attention for creating meta-structures and meta-materials with exceptional characteristics, such as unprecedented stretchability. These properties, not typically inherent in the original materials or structures, present new opportunities for applications in stretchable and wearable electronics. However, despite its scientific and practical significance, the application of kirigami patterning on a monolayer of tungsten disulfide (WS2), an emerging two-dimensional (2D) material with exceptional mechanical, electronic, and optical properties, has remained unexplored. This study utilizes molecular dynamics (MD) simulations to investigate the mechanical properties of monolayer WS2 with rectangular kirigami cuts. We find that, under tensile loading, the WS2 based kirigami structure exhibits a notable increase in tensile strain and a decrease in tensile strength, thus demonstrating the effectiveness of the kirigami cutting technique in enhancing the stretchability of monolayer WS2. Additionally, increasing the overlap ratio enhances the stretchability of the structure, allowing for tailored high strength or high strain requirements. Furthermore, our observations reveal that increasing the density of cuts and reducing the length-to-width ratio of the kirigami nanosheet further improve the fracture strain, thereby enhancing the overall stretchability of the proposed kirigami patterned structure of WS2.

The machining torch movement for the rectangular plasma sheet metal cut.

The sheet metals can be cut into rectangular or irregular pieces, where the main objective is to minimize the sheet metal's physical waste. However, the operating time, the number of movements to cut all rectangles edges, and the cutting process quality, must be considered. The objective of this research was to compare the machining torch movement behavior using optimal and alternative solutions for rectangular plasma sheet metal cuts. A bottom-left-fill heuristic and a tabu search heuristic were used to find the alternative solution, while the optimal solution was obtained with a mixed-integer linear programming. The comparison was developed considering three parameters: the total processing time, the effective distance traveled by the machining torch to cut the metal, and the movement distance traveled by the machining torch without cutting the metal. The packing layout given by alternative solutions can reduce the operational cutting processing time and the distance covered by the machining torch movement. From an economic perspective, optimal solutions are recommended when compared to alternative solutions given the lower expenses with raw material waste.

Numerical investigation of heat transfer augmentation and frictional loss characteristics in heat exchanger tube with the use of novel perforated rectangular cut twisted tape

ABSTRACT This paper focuses on augmentation of heat transfer and thermal performance factor of tubular heat exchanger by using a novel Perforated Rectangular Cut Twisted Tape (PRCTT) and comparison was made with Plain Tube (PT), Simple Twisted Tape (STT) and Rectangular Cut Twisted Tape (RCTT). Analysis of Nusselt number and friction factor for the twisted tape insert having twist ratio (TR) of 3, rectangular cuts of 2 mm width and 1 mm depth is done. Rectangular cuts of different pitch, that is, 3 mm, 5 mm and 7 mm is used for the analysis. To reduce the friction factor, further analysis has been done with perforation of circular hole in the same RCTT with perforation ratio (d/w) of 0.55 in the core of insert. Numerical analysis shows that in turbulent zone (4000<Re > 16000), highest enhancement in Nusselt number is 2.3 times and highest enhancement of friction factor by 3.2 times with comparison to plain tube when reducing the pitch of rectangular cuts. Perforation further decreases the friction factor by 20%. Highest thermal performance factor is observed 1.48 with the use of Perforated Rectangular Twisted Tape (PRCTT) at Re = 4000.

A COMPACT 1 &amp;times; 2 MIMO ELLIPTICAL PATCH ANTENNA FOR 5G 3.5 GHz APPLICATIONS

For 5G 3.5 GHz applications, a compact 1&amp;times;2 multiple inputs and multiple outputs (MIMO) elliptical patch antenna is proposed. An antenna that has dimensions of 21.5 &amp;times; 43 &amp;times; 1.6 mm3 with MIMO is constructed on a FR4 substrate with 4.4 relative permittivity. Rectangular cuts are employed on an elliptical patch, and antenna elements are arranged orthogonally to achieve a better isolation of -20.08 dB at the resonant frequency of 3.5 GHz. A 3.29-3.8 GHz bandwidth is produced below -10 dB through ground plane construction. The proposed antenna gain is 2.36 dB. The MIMO features are calculated with good results, including ECC &amp;#60; 0.003, DG &amp;#62; 9.9998, TARC &amp;#60; -10 dB, CCL &amp;#60; 0.3, and MEG.

Wideband improvement for hybrid plasmonic fractal patch nanoantenna

A wideband improvement for hybrid plasmonic fractal patch nanoantenna is presented for use in intra/inter chip optical interconnects. The suggested fractal patch antenna covering a part of U-band (1625-1675), L-band (1565-1625nm), C-band (1530-¬1565nm), S-band (1460-1530nm), E-band (1360-1460nm) and most of O-band (1260-1360nm) optical communication bands. The proposed antenna has a promising future use in inter and intra chip optical communications to eliminate electrical interconnection limitations such as interconnect density, power consumption and also increasing data rate. The performance of this antenna has been evaluated using full wave simulation computer simulation technology (CST) Microwave software. The impedance bandwidth is largely enhanced by applying rectangular fractal cuts to the both sides of patch. The proposed antenna achieves a wider bandwidth from 168 THz to 228 THz (B.W.=60 THz), which is about 8 times greater the bandwidth of reference antenna with a good gain and more than 95% radiation efficiency throughout the operational bandwidth.

Mathematical modeling of planar physically nonlinear inhomogeneous plates with rectangular cuts in the three-dimensional formulation

Mathematical models of planar physically nonlinear inhomogeneous plates with rectangular cuts are constructed based on the three-dimensional (3D) theory of elasticity, the Mises plasticity criterion, and Birger’s method of variable parameters. The theory is developed for arbitrary deformation diagrams, boundary conditions, transverse loads, and material inhomogeneities. Additionally, inhomogeneities in the form of holes of any size and shape are considered. The finite element method is employed to solve the problem, and the convergence of this method is examined. Finally, based on numerical experiments, the influence of various inhomogeneities in the plates on their stress–strain states under the action of static mechanical loads is presented and discussed. Results show that these imbalances existing with the plate’s structure lead to increased plastic deformation.

Hydrothermal performance improvement of an inserted double pipe heat exchanger with Ionanofluid

To meet the growing energy demand, double pipe heat exchangers (DPHEX), which are used in a variety of energy and thermal engineering applications, require improved heat transfer performance. In this study, a new class of surfactant-free Ionanofluid is formulated at three different concentrations of 0.01, 0.05 and 0.10 wt% and thermophysical and rheological properties are assessed. Zeta potential analysis is executed to assess the dispersion stability. An optimum concentration has been selected to investigate the hydrothermal performance of an insert fitted DPHEX at varying Re from 400 to 2000. The conventional twisted tape (TT) insert is modified by introducing different types of geometrical (triangular, rectangular, and circular) cuts on its surface. According to the Ionanofluid characterization, 0.10 wt % Ionanofluid has the highest thermal conductivity enhancement of 64% and heat capacity of 16.1% when compared to the base fluid, with a maximum enhancement in Nu of about 116–136% at varying Re. The rectangular-cut TT imparts highest heat transfer enhancement as the additional vortices is more intensive than other cut-inserts. Nevertheless, the value of PEC for the combination of Ionanofluid and RCTT insert, remaining between 1.61 and 1.68 over the entire range of Re, is greater than other combinations.

Факторы прочности лучевой кости после формирования краевого дефекта

Purpose To determine the effect of biometrical parameters of the radial bone and due to edge defect formed on the radius strength properties using calculation methods. Materials and methods The study of bone strength affecting factors was conducted with the aid of experimental and calculation methods. Biometrical parameters were studied in 10 pairs of the human cadaveric radius as an intact bone initially and after the formation of rectangular or triangle-shaped edge cuts. To determine the stress-strain behaviour, mathematical calculations were performed based on the beam flexural theory for isotropic materials. Computation study were conducted using the finite element method with the NX Siemens software package. Based on assumed mathematical models, the actual areas of safe loads in the presence of cuts and values of destructive loads depending on the depth and shape of a cut taking into account the initial curvature of the bone as well as the criteria of a required residual strength in variation of influencing parameters were identified by means of calculations. Results It was established that an increase in bone curvature results in the reduction of longitudinal destructive loads and in increasing values of the normal strength. The 0.05 bone curvature combined with the 0.5 cut causes a decrease in the ultimate load by 20 times (up to 4.8 % for a rectangular cut and to 5.4 % for a triangular cut). A 0.5-deep cut in the bone which curvature is 0.05 enhances the normal stress by 6.9 times for a triangular cut and by 7.8 times for a rectangular one as compared to a bone without curvature. The critical values for the curvature and depth of the cut were established which permit to avoid additional bone reinforcement. Conclusion The strength of the radius with a maginal defect depends not only on the depth of a cut but on its location, shape and on the radius curvature.

Vibrations of Plates with Complex Shape: Experimental Modal Analysis, Finite Element Method, and R-Functions Method

In this paper, the dynamic behavior of 3D-printed plates with different shapes and boundary conditions is investigated. The natural frequencies and mode shapes were determined using three different methods: the experimental analysis, the finite element method, using Nastran, and the R-functions method. The experimental and theoretical results are compared. The specimens tested included four cases. The test procedure is deeply described, and the material properties of the plates are given. The fixed-fixed configuration shows a better agreement both in the rectangular plate and in the plate with rectangular cuts, and the R-functions method gives better convergence with respect to the experimental and finite element analysis. The simply supported arrangement indicates some uncertainty in the boundary realization of the specimen.

Multi-modal tuning of vibrating bars with simplified undercuts using an evolutionary optimization algorithm

We present a method to tune the natural frequencies of a generic bar of mallet percussion instruments (e.g. marimba, vibraphone), for a set of predefined target frequencies, using a global optimization algorithm. The bar is modelled as a one-dimensional Timoshenko beam and its natural frequencies are calculated via 1-D finite elements. The undercut is made up of a series of rectangular cuts, which aside from reducing the dimension of the optimization problem to a few pairs of variables (height and length of each cut) also generates shapes that are easy to manufacture. Moreover, two penalty terms are added to the objective function, in a weighted manner, to (1) minimize the amount of extracted material and (2) minimize abrupt changes in profile height, aimed to alleviate the complexity and accelerate the manufacturing process.An evolutionary optimization algorithm is developed and extensive computational experiments are carried out to assess the algorithm’s performance and find appropriate parameter values for a faster convergence.The results illustrate the effect of the different penalties on the solutions obtained. Additionally, optimized shapes for various unorthodox and demanding tuning targets are presented and compared to previously published results, illustrating the benefits of the simplified undercut model.

Experimental investigation of heat transfer enhancement of a heat exchanger tube equipped with double-cut twisted tapes

An Experimental study has been performed to investigate the heat transfer characteristics and friction factors of fluid flow through a heat exchanger tube equipped with double-cut twisted tapes (DCTT) with different cut ratios. The rectangular cuts have ratio values ranging from 0.25 to 0.90. This study is carried out under turbulent flow regime (5000 ≤ Re ≤ 15,000) and water is selected as the working fluid. Due to swirl flows, DCTTs lead to more fluid mixing between the tube wall and core regions, which has considerable effects on the heat transfer inside heat exchanger tubes. The results show that by increasing the cut ratio from 0.25 to 0.90, the Nusselt number (Nu) enhances up to 177.4%. The thermal performance varies from 1.63 to 1.44 for the cut ratio of 0.90. Three correlations based on the experimental data are developed to predict Nu, f and η as functions of design parameters under turbulent flow regimes. These results provide evidence that the use of DCTTs is an effective technique to enhance heat transfer in a heat exchanger tube.

Cyclic performance of bolted end-plate RWS connection with vertical-slits

The reduced beam section (RBS) connections are widely used in construction buildings due to their desirable ductility and strength. The current reduced web section (RWS) connections are produced by a reduction in the beam web as circular or rectangular cuts or as horizontal slits. This article has proposed a new detail for the RWS bolted connection by creating vertical-slits in the beam web. The aim of this investigation is the evaluation of its cyclic performance in comparison with the conventional RBS connection. Two specimens, one with vertical-slits in the web (VS-RWS) and the other one with a radial-cut in the flange (RC-RBS), were experimentally tested and the results were compared. Moreover, numerical models were employed to evaluate the behavior of connections in detail. These two connections were able to move the plastic hinge region away from the column face, exhibit good hysteresis behavior, and satisfy the AISC requirements for special moment-resisting frames. The results also showed that the flexural capacity of the proposed VS-RWS connection is 10% higher than that of the conventional RC-RBS one, while their ductility and energy dissipation were almost the same. An important advantage of VS-RWS over RC-RBS is its ability to prevent the lateral-torsional instability. Besides, a numerical study was conducted to investigate the performances of various cut shapes RWS connections with certain overall dimensions and location of the cutting region in terms of hysteresis curves, rupture index and end-plate deformations.

Improving the Reliability of Eddy-Current Quality Control of Soldering in Current-Carrying Copper Joints and Expanding the Nomenclature of Inspected Joints in Energy Equipment

The possibilities of increasing the reliability of eddy-current quality control of soldering in current-carrying copper joints of the stator windings of electrical machines and expanding the nomenclature of inspected joints by using an improved eddy current transducer with a U-shaped core are investigated. To achieve this goal, rectangular cutouts were made in the poles of the U-shaped core, made of transformer steel plates, to allow the transducer to be mounted on a tested solder joint in two mutually perpendicular directions. Using such a transducer for testing allows one to induce closedloop eddy currents in the solder joint along these two directions, thus significantly improving the reliability of testing by virtue of all soldered surfaces in the joint contributing to the eddy-current transducer signal. The use of such a transducer also significantly expands the range of tested joints due to the possibility of exciting closed-loop eddy currents perpendicular to the direction of such joints (testing the side walls of the joints). It is shown that despite local changes in the distribution of electromagnetic field in the interpole space as compared to the case of no cuts, the presence of rectangular cuts in the poles of the U-shaped core of the eddy current transducer practically does not affect the accuracy of determining the degree of soldering of tested joints along and perpendicular to their direction.

Usage of machine learning for the separation of electroweak and strong Zγ production at the LHC experiments

Separation of electroweak component from strong component of associated Zγ production on hadron colliders is a very challenging task due to identical final states of such processes. The only difference is the origin of two leading jets in these two processes. Rectangular cuts on jet kinematic variables from ATLAS/CMS 8 TeV Zγ experimental analyses were improved using machine learning techniques. New selection variables were also tested. The expected significance of separation for LHC experiments conditions at the second datataking period (Run2) and 120 fb−1 amount of data reaches more than 5σ. Future experimental observation of electroweak Zγ production can also lead to the observation physics beyond Standard Model.

Log-periodic dipole array-based MIMO antenna for the mobile handsets

A novel design of multiple input–multiple output (MIMO) antenna based on the log-periodic dipole array (LPDA) for the mobile handsets is presented. The antenna operates in a wide frequency range of 1.86–3.84 GHz compatible with GSM, LTE, WLAN, and WiMAX. The MIMO design consists of two symmetrical and orthogonal radiating elements and a neutralization line (NL). The radiating element comprises a LPDA having a series of printed dipoles connected together with a microstrip line. Triangular and rectangular cuts on ground plane are carried out in accordance with the LPDAs so as to increase the impedance bandwidth and isolation. The antenna elements are linked with the NL to further enhance the isolation between the radiating elements. The performance of the MIMO antenna is analyzed in terms of S-parameters, radiation pattern, gain, total efficiency, envelope correlation coefficient, mean effective gain, multiplexing efficiency; and then it is verified through the measurements. The results demonstrate that the proposed MIMO antenna has good characteristics of wideband, gain, radiation pattern, isolation, and diversity.

GEOMETRY, PENETRATION FORCE, AND CUTTING PROFILE OF DIFFERENT 23-GAUGE TROCARS SYSTEMS FOR PARS PLANA VITRECTOMY

To investigate the geometry, penetration force, and cutting profile of 23-gauge trocar systems for pars plana vitrectomy based on their grinding methods in a standardized laboratory setting. In this experimental study, Eleven different commercially available 23-gauge sclerotomy trocar systems were divided into 4 groups according to their needle grinding and deburring: "back" bevel, "spear" bevel, "lancet" bevel, and "spatula" bevel. The normative geometrical data of the trocar systems were systematically analyzed according to nomenclature ISO 7864 and ISO 9626. Force to penetrate a 0.4-mm thick polyurethane foil was measured by a Penetrometer, when the trocar needle was piercing, cutting, and sliding through the foil at different defined loading phases and plotted as a load-displacement diagram. Magnified images of the consecutive cut were taken under a microscope after the entire penetration through the foil. Three physicians used all trocar systems in a masked fashion on human sclera to evaluate the manual penetration force in 30° and 90°. The mean outer diameter of the trocar systems was 0.630 ± 0.009 mm, and the mean outer diameter of the trocars was 0.750 ± 0.013 mm. The mean point length was 3.11 ± 0.49 mm, and the mean length of the bevel was 1.46 ± 0.23 mm. The primary bevel angle was 10.75 ± 0.41°, and the secondary bevel angle was 65.9 ± 42.56°. The piercing forces of the back bevel and spear-pointed trocars/needles were at the same level (0.087 ± 0.028 N). The lancet-pointed needle had remarkable low piercing and cutting forces with 0.41 N (range, 0.35-0.47 N). The spatula bevel tip showed the highest penetration piercing force with 1.6 N (range, 1.59-1.73 N). The back bevel systems induced frequently triangular-shaped incisions, with two nearly rectangular cuts of short length. The spear bevels produced a regular characteristic linear cut. Especially, the lancet blade created straight cut with a linear wound apposition. Spatula trocar systems caused usually an arched accurate incision. The manual force to penetrate the human sclera in an angled and rectangular angle appeared in the surgeons hand lower with a back bevel, lancet, or spear tip, whereas higher with spatula bevel systems. Lancet and back bevel systems show less penetration force of inner needles than the spatula systems. The results of the penetration force experiments correlated well with the manual force on sclera.

A compact asymmetric slot dual band antenna fed by CPW for PCS and UWB applications

A compact slot antenna with an overall dimension of 30 × 30 × 1.6 mm3 is proposed for dual band applications. The radiating element is a hexagonal shape patch which protrudes from a Co-Planar Waveguide (CPW) feed into a step shape slot. The slot is basically rectangular in shape and is extended by inserting rectangular cuts of different sizes on the ground plane around it. The ultrawide impedance bandwidth is achieved using asymmetric feed line along with extended rectangular cuts around the slot. For realizing the second band for personal communication system applications (near 1.9 GHz), a metallic stub of quarter wave length is attached at the top of the slot. The measured impedance bandwidth (for S11 < −10 dB) is 110 MHz (1.86–1.97 GHz) for the first band and 9 GHz (3.0–12.0 GHz) for the second band. The antenna is further characterized by omnidirectional radiation patterns in the H-plane, dumb-bell shape radiation patterns in the E-plane and a peak gain of 3–5 dBi over the ultrawideband. All the measured results are found to be in good agreement with the simulated results. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:243–254, 2015.