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This paper reports on preliminary observations of an investigation of flows associated with models that mimic serrations on the leading edge of barn owl feathers. The objective was to use particle image velocimetry measurements to determine the capacity of singular and multiple curved (three-dimensional) serration models to modify the noise-reducing indicators of a narrow-channeled flow past a cylinder. Four models were tested: 3 singular serration models of respective angles of inclination, α = 24°, 27.5° and 31°, and a model consisting of an array of 3 serrations of α = 24°, 27.5° and 31°. Each case was subjected to flow of Reynolds number (based on the serration height and maximum velocity of the flow) of ∼2,000, simulating the flow regime of local flow around barbs of real barn owl flights. A planar particle image velocimetry technique was used to capture the midspan plane velocities to determine the effects of each model. The results show that using singular serration models of inclination angles than 30° may lead to disorganized spatial structures and enhanced turbulence levels. On the other hand, an array of only 3 curved serrations of different geometries can modify the spatial flow structure into a well-ordered one, resulting in a 50% reduction in turbulence intensities. These initial results suggest that under complex flow conditions, the insertion of single and multiple curved serrations can lead to significant flow changes that may result in potential noise modifications. [ABSTRACT FROM AUTHOR]

This work reports the synthesis method and various properties of four rod-like antiferroelectric (R) laterally substituted enantiomers, with or without fluorine atoms used as substituents in the benzene ring. The influence of fluorine substitution on the mesophase temperature range was determined. The synthesized compounds are three-ring rod-like smectics with a chiral center based on (R)-(−)-2-octanol. Their chemical and optical purity was checked using high-performance liquid chromatography (HPLC). Two newly synthesized enantiomers and three previously reported (R) enantiomers were used to formulate two antiferroelectric mixtures. The mesomorphic behavior was characterized by polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction (XRD). The helical pitch and tilt angle measurements were done using the selective light reflection phenomenon and the electro-optical method, respectively. All the enantiomers exhibit a wide temperature range of the antiferroelectric phase, with a high tilt angle. Furthermore, the enantiomer with lateral fluorine substitution in the ortho position has a very long helical pitch (more than 2.0 µm), relatively low enthalpy of melting point, and a tilt angle close to 45 degrees. The designed (R) enantiomers can be useful for formulating eutectic mixtures for further use in various devices, including photonics and optoelectronics. [ABSTRACT FROM AUTHOR]

Ensuring the safety of transmission line towers is vital for human safety, power supply, economic development, and environmental protection. This study specifically examines how temperature affects tower inclination. Multifractal detrended cross-correlation analysis (MF-DCCA) is a combination of multifractal detrended fluctuation analysis (MF-DFA) and DCCA that reveals the multifractal features of two cross-correlated non-stationary signals. This paper adopts the MF-DCCA tool to investigate the cross-correlations between the internal temperature of an inclination sensor device and the posture of a transmission line tower. The tilt angle data in the x- and y-axes are used to measure the posture of the transmission line tower. We start by using Pearson correlation to assess the relationship between temperature and two inclination angles, followed by verifying their correlation with a p-value below 0.05 using first-order linear fitting. We initially assess the multifractal features of three time series using MF-DFA before MF-DCCA analysis. All exhibit multifractal traits with H (2) < 0.5 , indicating negative persistence, especially notable in the temperature series. Finally, we adopt the MF-DCCA approach to examine the multifractal cross-correlation between tilt-angle time series and temperature time series, and the results indicate the negative persistence of the cross-correlation between the time series. Furthermore, the multifractal cross-correlation of temperature and inclination data on the y-axis was also found to be stronger than on the x-axis based on features of the scaling exponent and symmetry exponent. [ABSTRACT FROM AUTHOR]

The verticality of a dynamically installed anchor (DIA) during free fall in water is vital for successful installation of the anchor within the seabed. Two lines, a deployment line and a mooring chain, are usually used to install a DIA. The mooring chain is prereleased to the seabed surface, presenting a catenary profile in the seawater. When the anchor is released and falls freely in the seawater, the verticality of the anchor is affected by the tension on the pad eye resulting from the connected mooring chain. Therefore, a vertically hanging arrangement method for the mooring chain is proposed, which is effective in reducing the tilt angle of the anchor during free fall in water compared with the traditional catenary arrangement method. Model tests are subsequently designed to justify the effectivity of the vertical-hanging arrangement of the mooring chain. Finally, a theoretical framework is established to predict not only the fall velocity but also the tilt angle of the DIA during free fall in water, with the deployment line and mooring chain taken into consideration. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper discusses a new method for measuring and calculating the angle of inclination of a railway support or a contact network support, using an unmanned aerial vehicle flying along a straight path, parallel to the railway track. A review of existing measurement methods is carried out, their advantages and disadvantages are indicated. In the method under consideration, it is proposed to measure angles and distances with six laser scanning rangefinders installed in threes on horizontal and inclined planes on an unmanned aerial vehicle. This allows you to increase the speed and accuracy of determining the angle of inclination of vertical supports. The calculations use the minimum distances from the laser scanning range finder to the top and bottom of the support surface. The formulas use geometric relationships and the cosine theorem to calculate the roll of supports taking into account their taper. Measuring distances and angles three times allows for averaging over them, which significantly increases the accuracy of calculations. A model experiment is carried out on a model of a reinforced concrete contact network support in four orientations. A comparison is made between theoretically calculated and experimentally measured distances and inclination angles. The accuracy of parameter determination complies with regulatory requirements.

To gain insight into the organization of the underlying structures in the northern Tunisia region, detailed gravity data in combination with geological information have been investigated. Many techniques have been used, including residual, upward continuations and derivative. Results from the edge detection technique based on the tilt angle map generated from the first vertical gradient were discussed and compared with results obtained by Euler deconvolution. The compilation and comparison of gravity maps and geology maps enable the determination of major structural trends. It validates specific structural elements acquired from outcrops and specifies new ones. According to the gravity data interpretation, the area of study is impacted by several underlying structural trends. The main trend direction is NE–SW, which is closely linked to the J Chehid and Bled Tejra Akseb trends. NW–SE direction is the second significant trend that borders Bled El Ghorfa to the north. Additional determined trends include: the N–S direction, which is associated with the Lakouat fault. A strong correlation was noted between results from tilt angle method and Euler deconvolution, showing that they may both be used to delineate the main structural framework of the region. [ABSTRACT FROM AUTHOR]

In order to ascertain how explosive load influences orthotropic slabs with short span stiffeners partially positioned in the x-direction, the purpose of this study is to perform a numerical analysis. The maximum displacement of a floor surface with respect to the force of an explosive load and the angle of inclination. It is feasible to calculate the impact of the angle of inclination and the height of the blast load on the vertical deflection of the slab using the 6th order polynomial blast equation, as long as the local blast load is positioned in the center of the slab. An analysis reveals that the vertical deflection of the slab is affected by the timing of the explosion. Specifically, a more powerful explosion has a diminishing effect on the deflection of the slab. The inclination angle has no major impact on the outcomes of deflection.

The passive cotton‐based Al‐air battery adopts the cotton cloth as the flow channel to transport the electrolyte by the capillary force from the cloth. An absorbent pad is usually put at the end of the cotton cloth to keep the electrolyte continuously flowing. Once the absorbent pad is saturated, the electrolyte flow slows down or even stops. This can affect the transportation of the electrolyte and product, decreasing the battery performance. To maintain the electrolyte's continuous flow, the cotton‐based Al‐air battery with the tilt angle was presented and constructed. The effects of the catalyst loadings, tilt angles, electrolyte types, and area ratios on this battery were studied. Under the 4 mg cm−2 carbon catalyst loading, 10° tilt angle, 4 mol L−1 KOH electrolyte, and anode‐to‐cathode area ratio of 1 : 3, this battery performance was optimal, with the peak power density of 78.09±0.68 mW cm−2 and limiting current density of 213.12±0.80 mA cm−2. Finally, the battery stack was gained by connecting the two batteries with the 10° tilt angle in series. This stack with a peak power of 48.47±0.37 mW could light the 44 LEDs. [ABSTRACT FROM AUTHOR]

We investigate the nematic (N) to twist-bend nematic (NTB) phase transition in binary mixtures of a symmetric liquid crystal dimer (CB7CB) and a calamitic bi-phenyl mesogen (7OCB). As the molar concentration of 7OCB increases, both the Iso–N and N–NTB transition temperatures decrease gradually, consequently, the width of the nematic phase above the NTB phase can suitably be varied from ~12 K to 46 K. Notably, as the nematic range expands, there is a remarkable reduction in transitional entropy, eventually approaching negligible or zero values. Additionally, the heat capacity peak and the phase shift disappear when transitional entropy reaches zero. This behaviour diverges from typical N–SmA and N–SmC phase transitions, where transitional entropy decreases near the tricritical point but the heat capacity peak persists. Our findings indicate a finite positive δ(∆n) across all concentrations at the N–NTB phase transition, suggesting a gradually weakening first-order nature. This contrasts with theoretical predictions of a second-order N–NTB phase transition, as our experimental data consistently supports a first-order nature. The self-consistent mean-field Landau Model successfully validates our experimental data, establishing the universal first-order nature of the N–NTB phase transition, with experimental entropy values in good agreement with theoretical prediction. [ABSTRACT FROM AUTHOR]

Nanosecond pulsed laser etching for fabricating anti-reflective gratings and inducing synchronous laser annealing was performed on Ag/AZO films. The optimum grating pitch was determined by performance analyses of laser-etched unidirectional gratings, based on which laser-etched bidirectional gratings were fabricated to further determine the optimum grating tilt angle. The results revealed that with the increase of grating pitch, the grating ridge total-side-area was gradually decreased to cause a gradually weakened anti-reflective effect, but the superimposed heat-affected zones between adjacent grooves became smaller or even disappeared, which brought about different synchronous laser annealing effects. The unidirectional grating-textured film with a medium grating pitch of 200 μm showed the best overall performance under the combined influence from anti-reflective gratings and synchronous laser annealing. For the bidirectional gratings, although increasing the grating tilt angle did not change the grating ridge total-side-area, it would enable the laser energy to be more uniformly distributed on the whole film surface, producing a better synchronous laser annealing effect. The bidirectional grating-textured film with a grating tilt angle of 90° had the best overall performance with the highest FOM value of 2.18 × 10−2 Ω−1 that was ∼3.2 times that of the as-prepared film. The results are instructive for preparing high-performance TCO-based films. [ABSTRACT FROM AUTHOR]

Pulsating heat pipes (PHPs) offer a promising solution for thermal management in diverse industries owing to their simplicity, cost-effectiveness, and impressive cooling capabilities. The angle of inclination of the heat pipe with reference to the horizontal plane significantly influences PHP performance. Unsatisfactory outcomes were observed at 90° and 180° inclination angles. A comprehensive investigation explored the impact of tilt angle and fill ratio on PHP performance indicators, specifically heat transfer rate (HTR), overall heat transfer coefficient (OHTC), and thermal resistance (TR). Tilt angles ranged from 30° to 60°, while fill ratios varied from 40 to 80%. To optimize PHP working parameters that maximize HTR, minimize TR, and enhance OHTC, a modified Taguchi approach was integrated with a robust multi-objective optimization technique. Empirical models for HTR, TR, and OHTC were developed and validated against experimental data. The recommended PHP working parameters are a 60% fill ratio and a 30° tilt angle. For the optimal parameters, HTR estimates ranged from 33.96 to 34.29 W, with the experimental value of 34.124 W falling within this range. TR estimates ranged from 0.0207 to 0.1097 °C W−1, encompassing the experimental value of 0.078 °C W−1. OHTC estimates varied between 835.8 and 958.42 W m−2 K−1, including the experimental value of 835.79 W m−2 K−1. The developed empirical relationships provide valuable insights into PHP performance for any fill ratio and tilt angle within the applicable range. PHPs find diverse applications in refrigeration, aerospace, waste heat recovery, and the utilization of low-grade energy. [ABSTRACT FROM AUTHOR]

Novel H-bonded liquid crystals (HBLCs) are synthesized and examined for their mesomorphic behavior. The HBLCs are prepared with Schiff base proton acceptors containing 8 and 18 carbons in the alkyl chain and the proton donor with 4-substituted benzoic acids. All the compounds exhibit smectic A mesophases, with one of the compounds exhibiting LC properties below 298 K. It is interesting to note that the ethoxy-substituted HBLCs exhibit a wide range of thermal stability. Density functional theory calculations revealed the formation of two hydrogen bonds between the substituted acids and the pyridine ring based on the orientation of the donor and the acceptor moieties. There are no significant changes observed in the hydrogen bond length with the increase in the chain length of the proton acceptor moiety, indicating the dilution of the cores by the longer alkyl chain lengths is compensated with the (+ I) effect of alkoxy substituents. Quantum chemical modeling studies on these molecules revealed the reduction in the HOMO–LUMO energy gap by approximately 0.3 eV for oxy-containing compounds, making them more chemically reactive by donating electrons (+ I) into the aromatic cores. These materials provide a significant breakthrough in designing innovative LC materials. This work is in support of the SDG-9 of the United Nations. [ABSTRACT FROM AUTHOR]

In the process of ascending and descending in deep-sea submerging and lifting cage nets, accompanied by changes in water pressure, pressure is one of the crucial environmental factors affecting the physiology and growth of fish. It directly relates to the comfort of farmed fish in the cage, thereby influencing the quality of aquaculture, especially for high-demanding species on the culture environment like the Larimichthys crocea. Investigating the stress level changes exhibited by L.crocea under environmental pressure variations, understanding the limit tolerance pressure, and its changes, can provide a theoretical basis for the design, application, and increased production of deep-sea submersible cage nets and L.crocea aquaculture. This study explores the effects of varying submersion depths (0–20 m) and speeds (0.6, 1, 1.3, 2, 4 m/min) on the behavioral responses of L.crocea in deep-sea cage environments. Key findings demonstrate that increased submersion depths and speeds significantly influence the physical behaviors and stress responses of the species. At submersion depths of 15 meters and 20 meters, the average swimming speed of the L.crocea exceeds 0.05 meters per second, the tail movement frequency is 1.42 times that of normal pressure, and the gasping frequency exceeds 20%., and at the highest speed of 4 m/min, the swimming speed reaches 0.0902 m/s—3.76 times greater than under normal pressure. The study determines that a submersion depth of 10 meters and a submersion speed of 0.6 meters per minute can minimize stress responses, providing critical insights for optimizing deep-sea aquaculture operations of L.crocea. These results offer valuable guidelines for the design and management of submersible cage systems. [ABSTRACT FROM AUTHOR]

The structure of the antiferroelectric smectic CA phase is investigated for two liquid crystals with almost identical molecular structures, except for chiral centers. The X-ray diffraction results determined the crystal unit cell parameters, smectic layer spacing, average distance within layers, and correlation length of the short-range positional order. The coefficients of thermal expansion are determined for the crystal phases. The molecular modeling with the semi-empirical PM7 method and density functional theory calculations with the def2TZVPP basis set and B3LYP-D3(BJ) functional are applied to determine the tilt angle of molecules from the experimental smectic layer spacing. The most probable conformations are then selected based on a comparison with the tilt angle measured by the electro-optic method, known from the previous results. In the most suitable molecular models, the chiral chain makes an approximately 90° angle with the molecular core, and some fragments in the fluorinated part of the achiral terminal chain are in the gauche conformation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is of great importance to choose low-cost, high-performance/efficient and operating and protection equipment in accordance with the applicable legislation in electrical facilities. It is necessary to make calculations for the selection of the most suitable cable/line, measuring and protection system equipment. In this study, panel-inverter compatibility calculation, voltage drop, current control, short circuit, lightning risk and protection calculations, grounding resistance and grounding conductor calculations and tilt angle calculation were made for a grid connected photovoltaic system with a power of 0.4 MWe. It has been calculated that the allowable voltage range and maximum powerpoint voltage values of the selected inverter are compatible with the panel system. With voltage drop and current control calculations, copper cable cross section for each inverter output and solar board output were found to be 3x70+35 mm2 and 2(3x185+95) mm2, respectively, and transformer low voltage busbar 60x10 mm2. In order not to deform the low voltage busbars in peak short-circuit current, they should be placed at 10 cm intervals for 80 cm length. According to the transformer low voltage side phase-earth short circuit current, the cross-section of the grounding conductor should be at least 53.97 mm2 copper conductor. In the lightning protection facility of the panels, according to the rolling sphere method, it has been calculated that the air termination rods should be at least 0.84 m above the upper point of the solar panel. The optimum fixed panel tilt angle was found to be 32.08°. The calculations used in the study will benefit the practitioners in the design of grid-connected photovoltaic systems, in the selection of the most suitable electrical equipment with minimum size. [ABSTRACT FROM AUTHOR]

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Precision field management and modeling crop growth requires precise, efficient, timely, nondestructive, and cost-effective measurements of structural component including leaf area index (LAI) and leaf orientation based on the foliage mean tilt angle (MTA), which is defined as the average leaf inclination angle of a canopy. Two experiments were carried out to investigate 1) the influence of different nitrogen (N) fertigation levels and 2) cycles of water deficit on leaf orientation (specifically, MTA) of young tomato (Solanum lycopersicum cv. Florida 47). N rates were 10, 50, 100, 200, and 300 mg·L−1 (mg N per liter of water) and irrigation treatments were well-watered and deficit irrigation. MTA was measured using the LAI-2200C Plant Canopy Analyzer. Across the experimental period, low N supply to leaves reduced the angle between leaf petiole and stem (high MTA) and produced plants with more erect leaves compared with N-sufficient plants. The MTA for the 10 mg·L−1–N treatment ranged from 54.3° to 73.6° and higher levels of N (50 to 300 mg·L−1–N) had MTA between 36.4° and 51.9°. Compared with lower N level (10 mg·L−1), LAI of tomato plants fertigated with a nutrient solution containing 300 mg·L−1–N increased by 3.6- to 4.9-fold across the study period. Similarly, canopy normalized difference vegetation index (NDVI) and leaf N% values at 300 mg·L−1–N were 2- to 3-fold higher than at 10 mg·L−1–N. However, MTA did not consistently differ across the 100 to 300 mg·L−1–N rates. In terms of water treatments, MTA of well-watered plants ranged from 32.3° to 40.5° whereas the same plants at water-deficit level had MTA between 45.7° and 51.8°. Although the relationship between MTA and canopy LAI, NDVI as well as leaf N was inconsistent or not significant under well-watered and water-deficit conditions, leaf gas exchange components (photosynthesis, stomatal conductance, and transpiration) showed a significant negative relationship (R2, 0.39–0.81, P < 0.001) with MTA. Overall, leaf orientation, specifically MTA, was modulated by N levels (highest at 10 mg·L−1; lowest at 300 mg·L−1–N) and cycles of water deficit and therefore, MTA determination hold promise as a nondestructive method to assess N and water deficit in young tomato plants.

This paper reports on preliminary observations of an investigation of flows associated with models that mimic serrations on the leading edge of barn owl feathers. The objective was to use particle image velocimetry measurements to determine the capacity of singular and multiple curved (three-dimensional) serration models to modify the noise-reducing indicators of a narrow-channeled flow past a cylinder. Four models were tested: 3 singular serration models of respective angles of inclination, α = 24°, 27.5° and 31°, and a model consisting of an array of 3 serrations of α = 24°, 27.5° and 31°. Each case was subjected to flow of Reynolds number (based on the serration height and maximum velocity of the flow) of ∼2,000, simulating the flow regime of local flow around barbs of real barn owl flights. A planar particle image velocimetry technique was used to capture the midspan plane velocities to determine the effects of each model. The results show that using singular serration models of inclination angles than 30° may lead to disorganized spatial structures and enhanced turbulence levels. On the other hand, an array of only 3 curved serrations of different geometries can modify the spatial flow structure into a well-ordered one, resulting in a 50% reduction in turbulence intensities. These initial results suggest that under complex flow conditions, the insertion of single and multiple curved serrations can lead to significant flow changes that may result in potential noise modifications.

Fermented cassava roasting is an energy-intensive process that is commonly used to produce gari, a popular food in Nigeria made from cassava. Traditional roasting methods use firewood as an energy source, which is inefficient and harmful to the health of those who inhale the smoke (mainly women and children in rural communities) and contributes to deforestation. This work aims to investigate a developed fermented cassava roasting system driven by a concentrated parabolic solar collector. Important data on the gari production food chain was obtained from a work-study in a rural community: temperatures and moisture content. The roasting temperatures range between 85oC - 100oC. The parabolic dish solar collector was designed and fabricated to achieve temperatures between 118oC-154oC at optimum tilt angles at Port Harcourt (4°54′ 22.86″N, 6°55′ 27.52″E) climatic conditions. The focal length ranges between 50 mm and 80 mm, and the fluctuation of the focal point position was considered for the thermal storage system design. Gravel was used as a thermal storage, and heat transfer was enhanced through small internally placed mild steel rods. The experimentally obtained average total fry/roast time per batch (40g) was 24 min, which is greater than the theoretically obtained value of 8.5 min. The fermented cassava roasting experiment was conducted for three days with favourable weather conditions, achieving a maximum temperature of 101oC. This innovation is important in addressing the health risks associated with traditional fermented cassava roasting methods and moving towards zero-emission and zero-poverty innovative systems.

In the present work, a new configuration of the three-part blade (3-PB) Vertical Axis Wind Turbine (VAWT) is introduced. This new configuration is designed to further improve the aerodynamic performance of the 3-PB VAWT by tilting all three parts of every single blade along its central chord line. An optimization process is conducted to find the best tilt angle of blade parts in order to maximize the average total torque coefficient. The optimization process is applied to reference 3-PB VAWT with the help of a Genetic Algorithm (GA) and Artificial Neural Network (ANN) using the solutions of three-dimensional Reynolds averaged Navier-Stokes (RANS) equations at wind speed of 7 m/s and tip speed ratios from 0.44 to 1.77. Having analyzed different sets of tilt angles, a configuration with tilt angles of 30°, 31° , and 30° with respect to part 1, 2, and 3 was detected to be the best choice. The tilted 3-PB VAWT shows promising improvements in most tip speed ratios. Among them, a maximum improvement of 42.99% on the average of the total torque coefficient occurred at tip speed ratio of 0.89.

The numerical calculation model for the aero-acoustic analysis of a tilt rotor was established by combining the free wake method and the FW-H (Ffowcs Williams-Hawkings) equation. The numerical method was validated by using the tilt rotor′s aero-acoustic test results. The aero-acoustic characteristics of dual tilt rotors that take into account the force and moment trim of an aircraft in its typical transition path were calculated. The unsteady air load of a rotor blade and its noise data in different observational positions were acquired. The acoustic directivity and sound pressure level of the tilt rotor in its different tilt angles were analysed. The results show that: the acoustic directivity characteristics of an isolate tilt rotor and dual tilt rotors were quite different due to the superposition and offset during noise radiation; the sound pressure level first increases and then decreases along with the rotor′s tilt angle; the maximum sound pressure level occurs at the tilt angle of 30 degree; the acoustic directivity and sound pressure level in different tilt angles vary due to multiple factors such as the Mach number at the rotor tip, air load and rotor orientation.

This article provides an overview of recent advancements in the design and performance of flat plate solar collectors (FPSCs) for solar thermal power plants. The article highlights various strategies that have been explored to improve the efficiency of FPSCs, including the use of Micro Heat pipe Arrays, nano-materials, phase change materials, and novel tube geometries. The study emphasizes the importance of keeping costs low while improving overall collector efficiency and highlights the research gap in distinct aspects of FPSCs for heat enhancement. The article concludes that these advancements have the potential to significantly increase the use of solar thermal power, which could play a critical role in reducing our dependence on fossil fuels and mitigating climate change. This study examines the power potential and carbon emission reduction capabilities of solar collectors in India, taking into account the local climatic conditions and geographical location. The study also identifies major challenges and opportunities in the current research domain. Based on the analysis, the study highlights the opportunities for commercializing low cost solar plants in India. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this research paper, a well‐performing solar pump at the minimum cost of project life is designed and installed. Initially, the capacity of submersible pumps and discharge have been determined based on the water requirement of the crop and the size of the field. The total number of solar panels, inverter size, and motor pump system have been designed based on the law of conservation of energy. The two optimization techniques genetic algorithm (GA) and response surface methodology (RSM) have been used for analyzing the pump performance parameters and total cost. The GA tool has been used to determine the optimum tilt angle on which responses namely solar flux, solar panel efficiency, exergy, and pump efficiency should be maximum. Moreover, the performance of the solar pump at the optimum tilt angle has been compared with the 28° fixed tilt angle (latitute of location). For the experimental study solar pump experimental setup of 5 hp power has been installed in Faculty of Engineering and Technology, MJP Rohilkhand University at 28.36°N, 79.43°E. The total cost of the solar pump has been optimized with the help of RSM based on the discharge and head of the solar pump. The new optimization approach reduced the levelized cost of electricity (LCOE) from 0.041 to 0.035 $/kWh and the payback period is reduced from 4 to 3 years. The annual increment in average solar flux and overall efficiency has been recorded to be from 606 to 697 W/m2 and 11% to 14% respectively. [ABSTRACT FROM AUTHOR]

The operating temperature increase in solar photovoltaic modules is a major problem, which affects their performance negatively. This numerical study introduces the effect of natural convection air‐cooling on the performance a novel hybrid photovoltaic/thermal collector. The standard k‐ε turbulence model is implemented for describing the turbulent natural convection. For improving the heat transfer rate of a novel photovoltaic/thermal collector system (PV/T), a sloped entrance channel (SEC) and an aluminum flat plate (AFP) were installed. The effects of SEC geometry parameters, the number of AFP and their distance to the photovoltaic module (PV) on the average Nusselt number are investigated. In addition, the effect of the PV/T system tilt angle and Rayleigh number on the thermo‐hydrodynamic flow behavior has been discussed. The results indicated that the heat transfer rate of the new hybrid PV/T system was improved by up to 20%, compared to the reference case without an aluminum flat plate. In addition, increasing the tilt angle of the PV/T system boosts airflow velocity, particularly for high Rayleigh number values (with and without AFP). Furthermore, several correlations, as functions of Rayleigh numbers and inlet channel dimensions, have been developed to predict the average Nusselt number. [ABSTRACT FROM AUTHOR]

The design of a floating wind turbine (FWT) should satisfy the serviceability limit state (SLS) requirement for an efficient and safe operation throughout the entire work life. The SLS requirements are introduced by the owner/developer of the wind turbine facility to achieve serviceability (production of power) or an efficient operation of the facility or a "first step" towards ensuring safety. Currently, there is limited information about SLS requirements in design standards. This study deals with an assessment of current methods, criteria, and procedure for the SLS design check with an emphasis on tilt/pitch and nacelle accelerations in view of power production and its fluctuations. Moreover, other criteria, on the borderline between serviceability and safety criteria, e.g., relating to clearance, are briefly discussed. The criteria relating to power production are illustrated in a case study with a 10-MW semi-submersible FWT considered for an offshore site in the Northern North Sea. Simplified static/dynamic analysis methods for use in the global design phase and high fidelity integrated, dynamic analysis methods for detailed design in terms of serviceability are presented, discussed, and applied in the case study. A good understanding of wind turbine dynamic performance associated with serviceability is essential to facilitate design decision-making. The relative contribution of wind and wave loads to the different SLS criteria is investigated. Finally, the main conclusions are summarized. In lieu of the current state of the art regarding SLS requirements for FWTs, we hope that this study provides a basis for improving design standards and guiding research and engineering practice for the semi-submersible floater design of FWTs. [ABSTRACT FROM AUTHOR]

Based on Global Coupled Ionosphere‐Thermosphere‐Electrodynamics Model, the solution of the 3‐dimensional current in the ionospheric region, the equivalent sheet current and filed‐aligned current are examined. The simulation study enables a comprehensive analysis of the effect of the geomagnetic field configuration, especially the non‐dipole component and tilt angle, on the ionospheric electrodynamics phenomena. Different geomagnetic field configurations are specified in the present work, including realistic geomagnetic field (RGF), tilted dipole geomagnetic field (TDGF) and zero‐declination dipole geomagnetic field (ZDGF). Our simulation focuses on the seasonal variation of Sq current, primarily governed by annual and semi‐annual variation. The modulation of the tilt angle of the geomagnetic field is globally distributed, whereas the modulation of the geomagnetic anomaly is localized. At mid‐latitudes, the annual mean and semi‐annual amplitudes of the Sq current are negatively correlated with the magnetic field strength, especially shown in geomagnetic anomaly area, while there is the opposite effect in the geomagnetic conjugate regions of the opposite hemispheres. The annual variation of Sq current system is more affected by the offset of the geomagnetic latitudes and geographical latitudes. The seasonal variation of the total Sq current is also modulated by the geomagnetic field. The annual mean, the annual and semi‐annual components of the total Sq current are negatively correlated with the magnetic field strength, while the annual variation is also controlled by the tilt angle of the geomagnetic field. The solar radiation affects the semi‐annual variation of the current more strongly than the annual variation. Plain Language Summary: Ionospheric currents and magnetic fields exert significant influences on energy and material transport within the ionosphere, playing a pivotal role in Earth's electromagnetic environment, which is the primary focus of ionospheric research. To investigate the impact of the geomagnetic field on the ionospheric current system, we employ a theoretical model (GCITEM) for simulation work. In this simulation, we consider both the realistic geomagnetic field configuration and two hypothetical idealized configurations of the geomagnetic field: one excluding non‐dipole terms and the other further aligning the geomagnetic axis with Earth's spin axis. The analysis of the longitude and the seasonal variation of the simulated currents under realistic magnetic field conditions has been validated through previous observation results. In comparison to simulation results obtained under hypothetical configurations, we discern and analyze the modulation and mechanism of non‐dipole terms and the tilt angle of geomagnetic field on the variability of the ionospheric current system, which are discussed in detail within this paper. This study facilitates the analysis and prediction of long‐term changes in the geomagnetic field's effects on ionospheric current generation and the impact on space's electromagnetic environment. Key Points: The geomagnetic field intensity exerts a significant influence on the Sq currents and exhibits a negative correlation with Sq currentThe annual mean and annual variation amplitude of Sq current are positively correlated with the geomagnetic anomaly at conjugate pointsThe tilt angle of the geomagnetic field affects the annual variation of Sq current globally, but hardly effects the semiannual variation [ABSTRACT FROM AUTHOR]

In this research article, the objective of the work is to maximize the performance of solar pump based on input variables. The solar panel and motor pump set are the important parts of solar pump. The overall performance of the solar pump has been depending on the performance of solar panels and motor pump set. The tilt angle, surface azimuth angle, module temperature and speed of motor are most important input parameters on which whole performance of solar pump depends. So, for fulling these objectives a 5 hp (horsepower) solar pump has been installed in FET MJP Rohilkhand University, Bareilly located at 28.36° N, 79.43° E. The experimental data of output parameters at the different settings of input parameters and data generated by model equations have been optimized by the Response Surface Methodology (RSM) tool of Design of Experiments (DOE). The optimum setting of input parameters are Tilt Angle (TA) (36.22°), Surface Azimuth Angle (SA) (−1.26°), Module Temperature (MT), and speed of the motor (2169.69 RPM). On the optimum setting of input parameters, the values of the response are maximum Solar Flux (SF) (762 W/m2), maximum power output (3661.4578 W), minimum discharge (19.2681 m3/h), head developed (55.17 m), maximum motor efficiency (90.7488%), maximum exergetic efficiency (15.3799%), minimum Levelized cost of electricity (LCOE) (0.0361 $/KWh), maximum panel efficiency (17.1774%) and maximum overall efficiency (15.0117%). [ABSTRACT FROM AUTHOR]

This experimental study aims to track the changes in electrical properties and energy behavior of two technically identical photovoltaic modules of the RAGGIE type (RG-M165W model) under different operating conditions. The first is the reference photovoltaic module, while the second is the targeted photovoltaic module. Both modules were tested under the same climatic conditions in the Algerian region of El-Oued. Numerous practical experiments were conducted to demonstrate the effect of using a solar tracking system (a horizontal single-axis tracking system manually moved from east to west), changing the tilt angle of the photovoltaic modules, and the cleanliness of the effective photovoltaic module area on their productivity. The study results showed a convergence between experimental and theoretical results. The optimal tilt angle of the photovoltaic modules in El-Oued during the study days is 33°, and any inaccurate selection of this angle results in an efficiency loss of 19.31 %. Additionally, manually tracking the solar path improved the photovoltaic module efficiency by 1.63 %. A decrease in energy productivity by 34.68 % was recorded due to dust deposition of 14.5 g.m−2. Economically, it was shown that installing a photovoltaic system consisting of 14 RAGGIE modules can feed a typical Algerian house with 136.6 MWh over 25 years, with a Levelized Cost of Energy of $0.037/kWh, and the CO2 mitigation is 59.15 tons with a saving of $858.

The aim of this investigation is to study the effect of using two different trapped gasses at the same time within two glazing and absorber plate in which the inner layer adjacent to the absorber plate was filled with Helium and the outer layer was filled with Argon to augment the heat gain and prevent heat missing that lead to 12.39 % enhancement in the performance of Gas Filled Double Glazed Flat Plate Solar Collector (GFDGFPSC) in comparison to Air Filled DGFPSC. As Collectors have to be installed at the best angle to gain the maximum irradiation, variation of DGFPSC's angle and both optical thicknesses were evaluated. On the basis of findings, AFDGFPSC's efficiency increased to more than 37 % when the angle was 60° while it was about 31 % at the angle of 30°. Efficiency of the Gas Filled DGFPSC increased a bit lower from 46.7 % to 49.6 % as the angle increased from 30 to 60°. Variations of both inner and outer optical thicknesses were examined at the angle of 60° where growth of the outer optical thickness made low effect on GFDGFPSC performance whereas inner optical thickness increment boosted the useful energy reservation and thus thermal efficiency up to 53.44 %.

This paper introduces a dual-polarized spline-loop antenna element and array. The antenna element consists of two pairs of cross spline-ring dipoles, each with four thin metal strips connected to the adjacent dipole arms, serving as antenna radiators. These radiators resonate within the frequency band n78 (3300-3800 MHz). To achieve one wavelength resonance, the radiators are designed as spline-loop to increase the resonant path. Each spline-loop is fed by an integrated balun connected to a $50~\Omega $ SMA. The thin strips connect the ends of the spline-ring dipoles to form a full-wave spline-loop. An integrated balun circuit is utilized to improve impedance matching and enhance the antenna’s operating bandwidth (approximately 36%). Moreover, to fulfill the electrical down-tilt range of 0 to 10 degrees for the 4-element dual-polarized antenna array used in base stations, a series-connected 4-way power divider is incorporated into the feed network. Each output Port of the power divider has a phase difference of 45 degrees, thereby inducing beam steering effects for the antenna array. Based on actual measurement results, the operating bandwidth of this antenna array covers the range of 2740 to 3910 MHz (approximately 34%), with isolation of 15 dB or greater, an electrical down-tilt of 10 degrees, and an antenna gain of approximately 11 dBi.

Ensuring the safety of transmission line towers is vital for human safety, power supply, economic development, and environmental protection. This study specifically examines how temperature affects tower inclination. Multifractal detrended cross-correlation analysis (MF-DCCA) is a combination of multifractal detrended fluctuation analysis (MF-DFA) and DCCA that reveals the multifractal features of two cross-correlated non-stationary signals. This paper adopts the MF-DCCA tool to investigate the cross-correlations between the internal temperature of an inclination sensor device and the posture of a transmission line tower. The tilt angle data in the x- and y-axes are used to measure the posture of the transmission line tower. We start by using Pearson correlation to assess the relationship between temperature and two inclination angles, followed by verifying their correlation with a p-value below 0.05 using first-order linear fitting. We initially assess the multifractal features of three time series using MF-DFA before MF-DCCA analysis. All exhibit multifractal traits with H(2)<0.5, indicating negative persistence, especially notable in the temperature series. Finally, we adopt the MF-DCCA approach to examine the multifractal cross-correlation between tilt-angle time series and temperature time series, and the results indicate the negative persistence of the cross-correlation between the time series. Furthermore, the multifractal cross-correlation of temperature and inclination data on the y-axis was also found to be stronger than on the x-axis based on features of the scaling exponent and symmetry exponent.

The performance and durability of proton‐exchange membrane fuel cells (PEMFCs) are constrained by fuel delivery and water management. Based on parallel and serpentine flow fields, the effects of triangular baffles (30°, 45°, and 60°) and conical runners (1°, 2°, and 3°) on the performance output of PEMFC at different angles are studied. The three‐dimensional and multi‐phase models are established by using the simulation software package (ANSYS FLUENT). The findings demonstrate that the battery's output performance reaches its peak when the baffle angle is set at 45°. When the output current density is 0.7 A/cm2, the power density of the 45° baffle increases by 18.87%. The pressure loss is not only lower than that of the 60° baffle but also exhibits no significant difference when compared to the 30° baffle. In addition, the introduction of conical channels has enhanced the output performance of PEMFCs in comparison to the traditional serpentine flow field. The power density of the 2°tapered channel exhibits a 12.65% increase when the output current density reaches 0.8 A/cm2. However, the performance output of the 3°tapered channel is inferior to that of the conventional serpentine flow field. [ABSTRACT FROM AUTHOR]

KCFLC 7S, a ferroelectric liquid crystal (FLC) shows improved dielectric and electro-optic properties by the incorporation of alloyed quaternary ZnCuGaS2/ZnS core/shell (ZCZ) quantum dots (QDs). Four different Zn alloyed ZCZ QDs (ZCZ-0, ZCZ-0.5, ZCZ-1, and ZCZ-1.5) incorporated in FLC and have been studied with the help of optical, dielectric and ferroelectric characterisations. Substantial changes of optical contrast, molecular ordering, photoluminescence, dielectric constant, dielectric loss factor, response time, and helical pitch of FLC are observed and attributed to varying molecular ordering. The effective confinement of exciton wavefunction in core of QDs results in improved molecular ordering of FLC material. The Zn alloyed ZCZ QDs incorporated FLC may be resulted for future brighter, high contrast, large viewing angle and memory based display device. [ABSTRACT FROM AUTHOR]

The Gulf of İzmit, which is in the northeast of the Marmara Sea, has significant implications for seismic hazard predictions due to its location on the northern branch of the North Anatolian Fault. The structural lineaments of the Gulf of Izmit were defined using high-resolution magnetic data. Initially, the data were corrected diurnal correction and filters were applied to remove noise effects. In addition, first vertical derivative, analytical signal, tilt angle, tilt angle of horizontal gradient (TAHG), softsign function (SF) filter methods were applied to the data to extract the lineaments of İzmit Gulf, and the boundaries of structural elements. TAHG and SF filters produced sharp and clear edges in the identification of structural elements causing magnetic anomalies. The main trend of the obtained lineaments is in the E-W and NE-SW directions in the gulf. The findings obtained from this study were also evaluated with seismic reflection sections and it was observed that the faults and lineaments in the sections were quite compatible. Thus, magnetic results provide a reliable structural map for a better understanding of the tectonic and structural framework of the İzmit Gulf. Thus, it is clear that the linearity map of the region obtained from the study will contribute to new research to be carried out in the future. [ABSTRACT FROM AUTHOR]

In this study, the optimum panel tilt angles were determined monthly in order to benefit from solar energy more effectively for solar energy applications to be carried out in Iğdır province. For this purpose, the monthly average daily total solar radiation (HT) values on the solar panels were calculated according to the tilt angle of the panel. The tilt angle was changed from 0° to 90° in 1° increments for each month. The angle giving the highest HT value in each month was taken as the optimum angle. Then, the HT values at monthly optimum angles and the HT values obtained when the panels are placed horizontally, with latitude angle, latitude angle ±15° and seasonal average optimum angle were compared. While the optimum angle was obtained as 0° in June, it was observed that the optimum angle was 58° in January and December. Placing the panels with monthly optimum angles provided 0.02% to 55.61% more solar radiation to reach the surface compared to other conditions. Compared to the latitude angle, an energy gain of 13.35%, 20.89% and 17.46% was achieved in May, June and July, respectively. The lowest solar radiation gain was obtained in October, compared to the seasonal average optimum angle, and the highest gain was obtained in January, compared to the placing horizontally throughout the year. [ABSTRACT FROM AUTHOR]

Detecting the boundaries of geologic structures is one of the main tasks in interpreting gravity anomalies. Many methods based on the derivatives of gravity anomalies have been introduced to map the source boundaries. The drawbacks of traditional methods are that the estimated boundaries are divergent or false boundaries appear in the output map. Here, we use the exponential transform of the tilt angle of the horizontal gradient to improve the edge detection results. The robustness of the presented method is illustrated using synthetic data and real examples from the Voisey's Bay Ni-Cu-Co deposit (Canada) and the Tuan Giao (Vietnam). The findings show that the presented technique can produce more precise and clear boundaries. [ABSTRACT FROM AUTHOR]

In this paper, the control problem for a novel walking assistance training robot is considered where the main objective is utilizing the robot to control the tilt angle and the position of a user. First, the novel walking assistance training robot together with a user is modeled as a nonlinear dynamical system in state space form with control input where the control input includes two elements standing for pulling forces on two straps which attach to the chest and back, respectively, of the user. Then, based on the nonlinear dynamical system and some results proposed in this paper, a feedback control system is developed, and a nonlinear state feedback control algorithm is designed where the control input includes two parts, namely, a dynamical part and a constant part. By doing this, it is ensured that the feedback control system is stable, and achieves the main objective under some limits for the control input. A simulation example is given to illustrate the effectiveness and performance of the proposed nonlinear state feedback control algorithm. [ABSTRACT FROM AUTHOR]

The analytic signal (AS1) has been widely used for mapping geological features from magnetic data. Some enhanced versions of the AS1 have been introduced to improve its effectiveness. Here, we compare the performance of these filters and introduce a filter obtained from the tilt angle and the directional analytic signals. For better performance on low latitudes, the directional analytic signals are obtained from the vertical integral of the magnetic anomaly rather than its magnetic potential. The proposed filter shows an apparent performance improvement in mapping the edges of magnetic sources, as shown with synthetic models and real example from the Olympic Peninsula, USA. The great advantage of the proposed technique is that the obtained result has lower influence from the magnetization vector direction than the AS1 and other related techniques. The findings demonstrate that the present method not only outlines the boundaries more precisely and clearly, but also reveals the presence of several structures obscured by nonmagnetic sediment in the study area, which are not determined by other methods. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Computational Mechanics / Jisuan Lixue Xuebao is the property of Chinese Journal of Computational Mechanics Editorial Office, Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Vickers and Knoop testers are the most common tools used to measure the hardness of materials. However, a very small tilt in the sample surface even in the order of a fraction of a degree produces a noticeable asymmetry, which affects the accuracy of the measured hardness. In this investigation, a mathematical approach has been used to correct asymmetry in the Vickers and Knoop indentations in both metallic and ceramic materials. Measurements were taken for metals such as aluminium 6061(Al-6061), 304 stainless steel as well as various zirconia toughened ceramic materials including tetragonal zirconia doped with: 2.5 mol% Y2O3 (TZ2.5Y), 3 mol% Y2O3 (TZ3Y) and the composite containing 20 wt% alumina (TZ3Y20A), all prepared from commercial powders. A hardness tester equipped with Vickers and Knoop indenters was used for hardness and elastic modulus determination. Optical and scanning electron microscopes have been used to get the indentation micrographs. The method enabled accurate determination of both hardness and elastic modulus from corrected Vickers and Knoop indentations. The hardness and elastic modulus values obtained in this study are in good agreement with reported data for similar materials. The results obtained in this study have been successfully validated using the Zwick reference block. The developed method is readily applicable for the most widely used Vickers hardness machines for the correction of asymmetric indentations if existing, consequently leading to accurate determination of the hardness.Article highlights: A simple correction method for asymmetrical Vickers and Knoop indentations was developed and applied on metallic and ceramic materials. This method enabled precise determination of hardness and elastic modulus values. The obtained hardness and elastic modulus values were consistent with those obtained by other techniques for similar materials. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)