Horizontal Side Research Articles

Largest unit rectangles inscribed in a convex polygon

We consider an optimization problem of inscribing a unit rectangle in a convex polygon. An axis-aligned unit rectangle is an axis-aligned rectangle whose horizontal sides are of length 1. A unit rectangle of orientation θ is a copy of an axis-aligned unit rectangle rotated by θ in counterclockwise direction. The goal is to find a largest unit rectangle inscribed in a convex polygon over all orientations in [0,π). This optimization problem belongs to shape analysis, classification, and simplification, and they have applications in various cost-optimization problems.

Illusion in Architecture: An Alternative for Creating Virtual Environment to Support Efficient Site Utilization

Virtual materiality has become a reality due to technological advancements. This affects the evolution of architecture. Land utilization in residential designs is currently unrestricted. Humans still exploit natural land and food supplies to build homes. Conversely, houses that merely use the land for viewing rather than traversing it are an example of inefficient land usage. In architecture, virtual materiality plays a part in creating an artificial world. In order to minimize land consumption, an architectural strategy that may introduce virtual materiality into the real world is required. Illusion is one tactic. Tricks and deceit are given priority in the illusion technique. This program is intended for home users who want to replace their natural surroundings with an artificial one. By using this method, nature can improve without requiring interference from the original environment. Modeling experiments and qualitative research are used in the research methodology. Create suggested concepts by using an architectural methodology. Rendering models and sketches are the research outputs. The findings demonstrate that home design can make use of illusion as a representation of virtual materiality. Through the application of matter illusion techniques, manufactured environments can be made to resemble natural ones. Implementing the material illusion in a trapezoidal home. Screen technology is used to do this. The center of the design is where screen technology is used to display environmental content. big horizontal and vertical sides are necessary. However, this can be a substitute for the natural environment for residents, especially in dwelling design.

Modeling of magnetohydrodynamic free convection in an enclosure having elliptical sinks using lattice Boltzmann method

AbstractThis paper adopted the Lattice Boltzmann Method (LBM) to compute a two‐dimensional incompressible convective flow field with two isothermal elliptical sinks attached vertically to the horizontal bottom north side of the enclosure, which is subjected to a horizontal magnetic field. The attained results show that LBM can effectively capture vortex shedding structures and other features inside such complex flow. Also, the Hartmann numbers with a panoply of heated sinks location were studied, and the results showed that fluid flow and heat transfer rate depend on the Hartmann number and are greatly influenced by the heated sinks positions. The effect of the Prandtl number on the average Nusselt number is also highlighted.

Circularly polarized 2 × 2 fractal antenna array for space borne tracking applications

A corporate feed sequentially rotated 2 × 2 circularly polarized fractal antenna array is investigated in this work. Four number of compact circular fractal antenna elements are positioned symmetrically across the geometry. The antenna elements in the subarray are incorporated with 1st order Koch fractal cuts and rotated with respect to its neighbor and the phase change thus generated becomes offset with the phase change in the excitation in the corporate feed. A 2nd order Minkowski fractal curve is implemented on the ground plane to optimize the radiation performance of the array. The proposed fractal antenna array (FAA) is powered with a coaxial feed, with its pin connected to the asymmetric line configuration placed on the top surface. The dimensional confinement of the array is limited to 0.904λ0 × 0.876λ0 × 0.012λ0 (fr = 2.27 GHz) and the overall layout of the geometry is built on a FR4 substrate having a dielectric constant of 4.4. The circularly polarized radiation characteristics of the elements are developed as a result of fractal cuts along the vertical and horizontal sides. A maximum gain response of 5.4 dBic is observed in the impedance band ranging from 2 GHz to 2.5 GHz. The measured results of the proposed array are found to be in good agreement. In quantitative comparison with a few existing arrays with respect to its diverse performance the proposed CP FAA is found to be suitable for space-borne applications operating in the S-band.

Crosstalk optimization and gate oxide reliability analysis in intercalation doped MLGNR with reduced vertical thickness

In this paper, the performance of intercalation doped multilayer graphene nanoribbons (MLGNR) with reduced vertical thickness is investigated, and the impact of crosstalk on latency and gate oxide reliability is analyzed. An unconditionally stable FDTD method is used to analyze the transient output of the circuit. Several cases of MLGNR with reduced vertical thickness under different doping materials, stacking directions and contact modes have been discussed. The experimental data show that the Li-doped MLGNR interconnect with horizontal stacking and side contact (SC) has the most outstanding performance, and the delay fluctuation caused by crosstalk is improved by 17.8 % ∼ 68.1 % compared with the Cu interconnect. When specularity p = 0.2, the PDCP (power delay crosstalk product) is found 44.2 % ∼ 61.5 % lower than the Cu interconnect. In addition, the AFR (average failure rate) has also been investigated, and the data showed that the AFR of Li-doped SC-MLGNR remained lowest among all interconnects discussed, for comparison the Cu interconnect is 4.2–5 times larger than the former. In summary, the vertical thickness reduced Li-doped horizontally stacked SC-MLGNR is very promising as carbon nano interconnects in the next generation of integrated circuits.

AFM probe with the U-shaped cross-sectional cantilever for measuring the ultra-low coefficient of friction of 10−6

Accurately measuring the coefficient of friction (COF) is the fundamental prerequisite of superlubricity research. This study aimed to reduce the COF measurement resolution Δμ of atomic force microscopy (AFM). Based on the theoretical model, a distinctive strategy was adopted to reduce Δμ by optimizing the cantilever’s cross-section of the AFM probe, inspired by civil engineering. Δμ can be reduced by decreasing the width of the horizontal side wR and the wall thickness t and increasing the width of the vertical side wH. Moreover, the I-shape demonstrates the highest reduction in Δμ, followed by the U-shape. Considering the processability, the AFM probe with the U-shaped cross-sectional cantilever was investigated further, and the dimensions are 35 µm wR, 3.5 µm wH, 0.5 µm t, 50 µm l (cantilever length), and 23 µm htip (tip height). The finite element analysis results confirm its reliability. After being fabricated and calibrated, the AFM probe achieves the minimal Δμ of 1.9×10−6 under the maximum normal force so far. Additionally, the friction detection capability of the fabricated AFM probe improves by 78 times compared to the commercial tipless-force modulation mode (TL-FM) AFM probe with the conventional solid rectangular cross-sectional cantilever. This study provides a powerful tool for measuring 10−6 COF.

Numerical investigation of thermal-mixing characteristics at vertically oriented T-junction pipelines

When hot and cold fluids are mixed at pipeline tees, temperature fluctuations are generated and can lead to thermal fatigue damage in the piping materials. At the University of Stuttgart in Germany, experimental investigations have been performed for understanding the flow mixing mechanism causing thermal fatigue. It was found that the inlet flow rate is one of the decisive factors on the mixing behaviors at a horizontal T-junction.In this study, the influence of the inlet flow rate on the flow mixing behaviors at the vertical T-junction is investigated using the large-eddy simulation (LES) method. The simulations are validated with the previous experiments and provide a good overview of the mixing flow. The LES method shows the advantage of illustrating the collision of two flow streams at the T-junction, which leads to different behaviors of the mixing flow. Generally, the temperature fluctuation in the mixing flow as well as the stability of thermal stratification decreases along the flow direction due to the dissipation of the turbulent kinetic energy in the mixing flow. The decrease in the main flow rate shows the impact of the increase in thermal stratification stability and the reverse flow distance. The decrease in the branch flow leads to a slight increase of the thermal stratification stability downstream of the T-junction and significant turbulent penetration in the branch pipe. The maximum temperature fluctuation at the pipeline inner surface is located at the joint position of the pipelines with a value higher than 30 K. Moreover, the flow collision at the T-junction leads to significant secondary flow in the mixing region, which can be influenced by the variations in the inlet flow rate. In particular, the secondary flow due to cold fluid presents a phenomenon of counter-rotating vortex pair (CRVP), and generates a temperature fluctuation with a frequency of approximately 1.1 Hz, which is recorded by the monitor points at both horizontal sides of the pipeline. In comparison with the previous work at the horizontal T-junction, the complete flow collision at the vertical T-junction is the reason for the totally different mixing phenomenon.

A DFT-based finite element model to study the elastic, buckling and vibrational characteristics of monolayer bismuthene

PurposeIn this paper, based on the density functional theory (DFT) and finite element method (FEM), the elastic, buckling and vibrational behaviors of the monolayer bismuthene are studied.Design/methodology/approachThe computed elastic properties based on DFT are used to develop a finite element (FE) model for the monolayer bismuthene in which the Bi-Bi bonds are simulated by beam elements. Furthermore, mass elements are used to model the Bi atoms. The developed FE model is used to compute Young's modulus of monolayer bismuthene. The model is then used to evaluate the buckling force and fundamental natural frequency of the monolayer bismuthene with different geometrical parameters.FindingsComparing the results of the FEM and DFT, it is shown that the proposed model can predict Young's modulus of the monolayer bismuthene with an acceptable accuracy. It is also shown that the influence of the vertical side length on the fundamental natural frequency of the monolayer bismuthene is not significant. However, vibrational characteristics of the bismuthene are significantly affected by the horizontal side length.Originality/valueDFT and FEM are used to study the elastic, vibrational and buckling properties of the monolayer bismuthene. The developed model can be used to predict Young's modulus of the monolayer bismuthene accurately. Effect of the vertical side length on the fundamental natural frequency is negligible. However, vibrational characteristics are significantly affected by the horizontal side length.

Augmentation of solar still distillation performance using waste heat energy and guiding vanes: A field study

This research proposes a new approach for increasing the productivity of solar still distillation units (SSDUs) while reducing environmental pollution and global warming by exploiting the wasted thermal energies from industrial and domestic applications as an additional heating source for the SSDU. This field study is accomplished by testing two SSDUs simultaneously; the first is a conventional SSDU, and the second is attached with an air duct beneath its base inside which a set of guide vanes is fitted on the lower horizontal side of the duct at several angles (0°–135°). Hot air flows through the duct simulating the waste heat source at several mass fluxes (1.45–6 kg/m2.s). The findings show that the heating airflow raised the temperatures and enhanced freshwater production and system thermal efficiency. The improvements are boosted by increasing the airflow rate and expanding the vane angle up to 120°. After a full day of testing, the modified SSDU achieved maximum productivity of 17.13 L/m2 and thermal efficiency of 34.2 %. Compared to the conventional SSDU, the modified SSDU showed maximum enhancements of 442 % in freshwater productivity and 66.8 % in thermal efficiency, leading to a reduction of the total cost of producing 1 L of freshwater by 70.5 %.

High-resolution seismic velocity structure using induced inter-event interferometry at the geothermal sites, Geysers, Eastern California

The possibility of retrieving Rayleigh wave empirical Green's functions (EGFs) using virtual seismometers provides an opportunity to calculate high-resolution velocity models without a set of dense stations and/or expensive seismic imaging/monitoring. The high-resolution tomographic map can give an overview of the fracturing within the saturated rock. Theoretically, the cross-correlations of earthquakes contain significant information about the EGFs between event-pairs. In this work, we developed an application of virtual seismometers on a very small scale in superficial layers where anthropogenic seismicity occurred. To test this method's capabilities, we applied it to investigate the NW-part of The Geysers (TG) geothermal field. We used 1276 micro-earthquakes, occurred in a cuboid with the horizontal side of ∼1 × ∼2 km and the vertical edge at a depth from 0.9 to 2.2 km, to obtain the high-resolution (100 × 100 m) velocity structure. A group of strict criteria was imposed separately for single event waveform and event pairs to stabilize the tomographic results. After retrieving the inter-event EGF signal and calculating the Rayleigh wave group velocity dispersion curves, we obtained the group velocity maps for each horizontal layer. The tomographic maps as a function of depth indicated a low-velocity anomaly related to existing inactive faults, topography variation of the top of the steam zone, and low-velocity anomalies possibly stimulated by fluid injection. The topography of the top of the steam varies from ∼1.0 km to 1.3 km of maps, and also anomalies connected with fluid migration appear at the depth of injection wells (1.5–1.9 km).

A NUMERICAL STUDY OF JOULE HEATING EFFECT IN ELECTRODEPOSITION PROCESS-CASE OF COPPER ELECTRODEPOSITION

The electrochemical process in the presence of heat dissipation effect (Joule heating effect) is highly detected in practical electroplating solutions such as 0.6 M CuSO4+0.5 M H2SO4 electrolyte, where currents passing through the cathode-anode-electrolyte increase temperature in the electrolyte and electrodes. Due to the complex nature of such systems and the diversity of physics describing it, a theoretical approach of appearance for natural convection on vertical and horizontal sides of a cathode in the presence and absence of Joule effect under unsteady state condition was observed using Comsol Multiphysics. It was found that the onset of natural convection on a vertical side depends on the Joule effect, and the time (tn) for appearance is longer on the edges than in other areas. The horizontal side of a cathode assists the appearance of natural convection in the presence and absence of the Joule effect. The Rayleigh (Ra) number has larger values on the vertical side than the horizontal side due to the effect of surface concentration distribution Cs. A Sherwood, Sh-Ra mathematical relation such that Sh=0.03Ra0.86 was proposed where natural convection had no pronounced effect on the deposition process. It was found that the Joule heating effect negatively affects the electrodeposition process by reducing the local current values.

Technical Evaluation of a New Medical Device Based on Rigenase in the Treatment of Chronic Skin Lesions.

Chronic wound is characterized by slow healing time, persistence, and abnormal healing progress. Therefore, serious complications can lead at worst to the tissue removal. In this scenario, there is an urgent need for an ideal dressing capable of high absorbency, moisture retention and antimicrobial properties. Herein we investigate the technical properties of a novel advanced non-woven triple layer gauze imbibed with a cream containing Rigenase, an aqueous extract of Triticum vulgare used for the treatment of skin injuries. To assess the applicability of this system we analyzed the dressing properties by wettability, dehydration, absorbency, Water Vapor Transmission Rate (WVTR), lateral diffusion and microbiological tests. The dressing showed an exudate absorption up to 50%. It created a most environment allowing a proper gaseous exchange as attested by the WVTR and a controlled dehydration rate. The results candidate the new dressing as an ideal medical device for the treatment of the chronic wound repairing process. It acts as a mechanical barrier providing a good management of the bacterial load and proper absorption of abundant wound exudate. Finally, its vertical transmission minimizes horizontal diffusion and side effects on perilesional skin as maceration and bacterial infection.

Analisis Business Model Canvas pada Perusahaan Ready Mix Concrete PT XYZ

The purpose of this study is to analyze the business model canvas (BMC) at ready mix concrete company PT. XYZ. This study used purposive sampling, the informants in this study were directors and heads of divisions. Data collection was carried out by observation, interviews, Forum Group Discussion (FGD) and literature studies. The research phase begins with the Business Model Canvas and SWOT, problem identification, data collection, data analysis, interpretation of results and conclusions. Through the analysis described above, the result is that PT. XYZ has implemented a Business Model Canvas. Results of the SWOT matrix by writing down opportunities and threats on the vertical side and strengths and weaknesses on the horizontal side. Based on the results of the SWOT matrix, there are 13 alternative strategies that PT XYZ can choose from. After conducting a Swot analysis of the business model canvas, then a new business model canvas is formed for the company's business model. The limitations of this study are limited to only using the Business Model Canvas analysis method and SWOT analysis, it is recommended to use the analytical method using QSPM to get better results. The informants in this study only focused on informants who came from internal company PT. XYZ. Suggested further research by adding informants from external parties PT. XYZ company.

Application of the Six Sigma Method to Minimize Leaking in Pillow Pack Cooking Oil Packaging at PT. ABC

PT. ABC is a company that has a cooking oil production business. In order to remain competitive with similar companies, the quality of the product must be maintained and improved. One of the problems of PT. ABC is the existence of leakage in the pillow pack packaging. The Six Sigma method can be used to identify the triggers for the leaking. This community service activity provides suggestions for improving the pillow pack cooking oil packaging process so that the amount of leaking can be reduced. Proposals are prepared by identifying the packaging process with reference to the Six Sigma method assisted by several statistical tools (check sheets, stratification, Pareto diagrams as well as fishbone diagrams). It was found that the highest leakage occurred on the horizontal side of the pillow pack (55%). On the basis of these findings, the proposed improvements lead to making a machine repair schedule at certain hours and then carrying out maintenance on the filling machine.

Reconstructing Internal Tides Field Based on Sampling by Autonomous Underwater Vehicles

This article explores the challenges and solutions of using autonomous underwater vehicles (AUVs) to observe internal waves in the ocean. Internal waves are highly dynamic and complex, and their rapid spatial and temporal variability makes it difficult to accurately observe them using AUVs due to Doppler smearing and aliasing effects. To overcome these challenges, the article proposes a Sparse Approximation (SA) method that reconstructs the sectional field of internal tides using AUV sampling data on horizontal-reciprocating vertical-dimension sawtooth (i.e., yo-yo) trajectories. The SA method is validated by numerical simulations in a temperature field of internal tides, and a series of reconstructions comparing the SA and linear interpolation method are conducted. The results show that the SA method produces accurate results if the signal frequency of the field is less than the Nyquist frequency of the water column sampling near the horizontal sides of the section. Notably, it reveals that the Doppler smearing and aliasing effects in the SA reconstructions can be effectively suppressed in the vertical isotherm fluctuation frequency range which is less than the Nyquist frequency of the water column sampling near the horizontal sides of the section. Additionally, the article evaluates the robustness of the SA method under different conditions, including AUV sampling behaviors, temperature field variation, AUV sensing and navigation errors. The findings demonstrate that the SA reconstruction method can be effectively used to observe internal tides with AUVs, and provide a design principle for an AUV reciprocating yo-yo sampling trajectory to achieve feasible field reconstruction of internal tides.

Numerical analysis of Magnetohydrodynamic convection heat flow in an enclosure

This article investigates the modeling and numerical simulation of Magnetohydrodynamic (MHD) buoyancy-driven convection flow in a differentially heated, square enclosure. Left vertical side is given a high temperature and the right vertical side is sustained at a low temperature. Horizontal sides of the enclosure are insulated. A constant magnetic field is presumed horizontally. Findings of the governing differential equations are explored numerically considering the impact of Magneto-hydrodynamic (MHD). Problem is deciphered by Galerkin finite element approach in COMSOL Multiphysics. Numerical solutions are computed for different values of Rayleigh number ranging 103≤Ra≤107 and Hartmann number ranging 0≤Ha≤40. Rate of heat that passes from the heated side is affected by increasing Rayleigh and Hartmann numbers. Comportment of MHD free convection heat flow from transient to steady state is numerically examined for a period of 0 to 1 s. The numerical solutions are discussed in respect of streamlines, iso-contours, and isotherms. In addition, physical quantities such as velocity and Nusselt number are studied. It is seen that with increasing values of Rayleigh number there is increase in local Nusselt number distribution on heated side of the cavity. Velocity distribution in the flow domain decreases in variations with increasing Hartmann number.

Effect of Yoga and Pilates exercises on lumbar spine physical parameters in healthy women

Purpose: In this study, it was aimed to examine the physical effects of participation in a Yoga and Pilates-based exercise program on the endurance and flexibility of the spine in order to protect the health of the lumbar region in healthy women.
 Methods: A total of 40 healthy women with a mean age of 41.62±6.91 years were included in the study. Participants were divided into two groups as Yoga and Pilates groups randomly. Both groups participated in an exercise program for 45 minutes a day, two days a week for 12 weeks. Sit and reach test was used to evaluate flexibility, and curl up, Static back endurance test and horizontal side bridge building test were used to evaluate endurance. 
 Results: When both exercise groups were compared before and after treatment, statistically significant difference was found in favor of post-treatment in all measurements (p0.05). 
 Conclusion: According to the results of our study, it was determined that both exercise types improved both flexibility and muscle endurance performance. However, it was seen that Yoga and Pilates exercises were not superior to each other in terms of flexibility and endurance. Both Yoga and Pilates exercise methods can be used safely to protect and improve general health and especially lumbar region health.

A morphine reward generalization mouse model based on conditioned place preference and aversion.

Conditioned place preference (CPP) is a common behavioral paradigm for studying the association of unconditioned stimulus reward memory with context. Generalization is a flexiblememory recall pattern developedon thebasis oforiginal memory. Drug-seeking behaviors in substance usedisorders(SUDs) exhibit diversity,which wegenerallyattribute to the highly generalizedfeaturesof SUD memory. However, to date, there are no animal models for SUD generalization studies. We design the generalization box (G-box) and the generalization retrieval process based on the conditioned place preference (CPP) model. In the memory retrieval stage, we replaced the conditioning CPP box (T-box) with a generalization box (G-box) to study drug generalization memory. For appearance, the generalized boxes have different angles and numbers of sides compared to the conditioning boxes. For the visual cues, the shapes of the symbols are different (triangle icons for the hexagonal chamber and dot icons for the round chamber), but the orientation information remains the same. To establish CPP generalization, the mice received morphine on the vertical or horizontal side of a conditioning box (T-box) andsaline on theotherside. Then, after CPP conditioning, the generalization test was performed in a generalization box (G-box: hexagonal chamber and Gr-box: round chamber) 21 days later. CPP-conditioned mice still displayed a clear preference for similar visual information in the G-box. CPA-conditioned mice behaved similarly to CPP, with mice consistently avoiding similar visual information in the G-box. We further observed that the generalization results are similar using two generalization boxes (G-box and Gr-box). In this study, we succeeded in creating a simple and effective generalization model for morphine reward. The establishment of this model provides a new tool for generalization studies of SUD and therapy in humans.

Development and testing of knife-plate connected steel panel dampers

Steel panel dampers (SPDs), consisting of the inelastic panel and elastic connecting segments, have been widely used in steel building structures commonly with brace- or stub-column-type configurations, especially in high seismic regions. The elastic connecting segments of stub-column-type SPDs were usually significantly enlarged to ensure their elasticity under the associated extreme loads of the inelastic panel. With the aim of improving the structural efficiency and ductility capability of SPDs, a novel design, named as knife-plate-connected SPD (KSPD), was proposed in the study. The proposed KSPD consisted of one steel panel and two boundary-columns on the horizontal sides with pinned column ends, which were achieved by knife-plate details, connecting to the framing systems. The designed configuration of KSPDs potentially reduced the aspect ratio of the steel panels for easily achieving shear yielding while remaining the stud-column appearance, and mitigated the deformation amplification of the steel panels usually occurred in conventional stub-column-type SPDs. Five full-scale KSPD specimens with various configurations of the panel stiffeners have been experimentally examined and compared under cyclic loadings including fatigue cycles. The feasibility of the KSPD design was experimentally validated, and the developed KSPDs were verified to achieve stable energy dissipation and significant ductility of approximate ten and cumulative plastic deformation (CPD) value up to 796. For the design purpose of the members, the width-to-thickness limits of the steel panel were established to prevent panel buckling and the sub-panel edge fracture upon the test results, respectively, and a design inequality of the knife plates upon strengths was developed to prevent the fracture of the knife plate. Finally, the design suggestions of the proposed KSPD were summarized upon the experimental results and findings of the study.

Series-Fed Millimeter-Wave Antenna Array Based on Microstrip Line Structure

This paper presents a millimeter wave series-fed microstrip line antenna array with low side lobes. For millimeter-wave beam forming applications, compact series fed arrays with very small horizontal width and low side lobes are very much required. The proposed array consists of a microstrip line with periodically placed stepped inverted-cone stub sections at a guided wavelength spacing. Surface current cancellation at each guided wavelength in an ideal microstrip line can be altered by symmetrically introducing the inverted-cone stub sections on two edges with a half wavelength offset. By controlling the dimensions and location of the inverted-cone stub sections, the equivalent surface currents can be altered and focused on the cone stub sections, resulting in an effective array radiation. The fabricated antenna array is resonating at 28 GHz and has an impedance bandwidth of 1.3 GHz. Peak realized gain of 10.2 dBi is achieved at 28 GHz and the measured side lobe levels are better than -15 dB in the E and H plane. The proposed microstrip line antenna array with low side lobes also benefits from simple fabrication and high integration ability, which makes it attractive for compact beamforming scenarios in millimeter-wave bands.