Angle Values Research Articles

Design Parameters for a Research Prototype Contactor

Rotating spiral contacting is a novel technologythat allows an excellent control of contacting between two ormore phases flowing countercurrently through spiralchannel. This method solve the issues can arise from mixingfluids by using the centrifugal effect to enforce the fluids toflow side by side in a narrow channel in parallel layerswithout mixing. In this work the wide channel model wasused to identify the design parameters for a researchprototype rotating spiral contactor, and examine theperformance within a wide range of operating conditions.The study included air – water system and started byselecting the optimum liquid layer thickness,  , that lead tooptimum specific throughput,*N  , and the appropriatemolar flow rate ratio, n q for absorption process. Drawingthe design envelope for pressure difference as a function ofchannel height was the best way of selecting the appropriatechannel height, h , and also study the effect of usingdifferent values of spiral angle, R sin . This later allowof selecting the suitable value of the distance betweenchannel revolutions, t . Finally, this work presents theeffect of using wide range of solute values, f ' on thepressure difference, phases flow rates, and the rotation ratefor fixed design parameters of a research prototype.

Effects of finisher diet nutrients density and slaughter age on energy and protein efficiency, productive and economic performance and meat quality of broilers.

The current broilers have been greatly optimized for weight gain and breast yield, which necessitates the provision of nutrients-dense diets for maximum potential. The current study aimed to evaluate the effect of finisher diet nutrients density (ND) on energy and protein efficiency, productive and economic performance and breast meat quality of broilers raised until different slaughter age. A total of 600 23-day-old broiler male chicks (Cobb-500) were assigned to 10 treatments with six replicates and 10 birds each. Experimental treatments were included factorial arrangement of five increment (2.5%) levels of finisher diet ND (92.5%, 95%, 97.5%, 100% and 102.5% as strain recommendation) and slaughtered at 38 or 46 days of age. The relative difference in the energy level of experimental diets was used to increase ND levels at the same ratio. Feed intake (FI) and breast meat quality traits exception water holding capacity (WHC) were not affected by finisher diet ND. In response to increasing finisher diet ND, energy and protein efficiency, productive traits, bio-economic index (BEI) and breast relative weight (BRW) linearly improved. However, residual feed intake and breast meat WHC improved with a quadratic trend. By using broken-line regression analysis, the optimum dietary ND was obtained at 97.5%-102% of strain recommendation. Energy and protein efficiency, feed conversion ratio and BEI deteriorated by prolonging rearing period. The BRW, meat lightness (L*), redness (a*), hue angle (h*) and WHC values for the birds slaughtered at 46 days of age were significantly higher, and cooking loss was lower than those slaughtered at 38 days old. Broilers during the finisher period are not able to regulate their FIs with diet ND. The energy and protein efficiency, productive and economic performance were reduced when broilers were fed diluted diet or the rearing period was prolonged.

Tectonic controls on the morphometry of alluvial fans in an arid region, northeast Iran

ABSTRACT The morphology of alluvial fans provides valuable information about changes in tectonic, climate, base level, and drainage basin characteristics. This study aims to evaluate the relationship between active tectonics and morphometric characteristics of alluvial fans in the less studied southern region of the Joghatay mountain, northeast Iran. The study area includes 13 alluvial fans and their corresponding catchment basins in a region with semi-arid climate. Morphometric characteristics of alluvial fans and their corresponding drainage basin including fan area, fan slope, sweep angle, fan toe length, fan radius, basin area, basin slope, fan’s width-to-length ratio, asymmetry factor, and basin shape were measured. Our results revealed a negative relationship between the slope of alluvial fans and their corresponding basin area. The weak correlation between the drainage basin area and the fans area may be attributed to the lithology and active tectonics in the study area. The small sweep angle values of the studied alluvial fans can be attributed to the activity of thrust faults and presence of an uplifting anticline that resulted in formation of elongated alluvial fans in our study area. Analysis of the relationship between the morphometric characteristics of the fans and their corresponding basins indicated a negative correlation, which can be attributed to the sediment transport efficiency of the basins.

Characterization of hemp seed oil emulsion stabilized by soap nuts (Sapindus mukorossi) extract

In the past years, plant-based surfactants such as plant proteins, hydrocolloids, and extracts have intrigued scientific studies of food formulations for usage in emulsion, nanoemulsion as well as microemulsion systems, mainly due to their functional benefits and low toxicity levels. In this work, a hemp seed oil-containing (HSO) emulsion system was stabilized using soap nuts (SN), also known as Sapindus mukorossi. In order to determine the formulation requirements and the optimal emulsion composition including oil and surfactant content, a Box-Behnken experimental design was applied. The compositions were evaluated in terms of their particle size distribution, stability, visual quality, turbidity, and zeta potential. Moreover, to describe the physicochemical characteristics of the emulsions, rheological tests, Fourier transform infrared spectroscopy (FTIR) analyses, and refractive index parameters were also studied. The average particle size of the emulsions (particle distribution by number) was recorded between 51 and 103 nm, and z-ave parameter reached values between 227 nm and 311 nm. The zeta potential increased when the proportion of HSO increased, and reached its highest value (−23.5 mV) when HSO was 5% v/v. Microscopic investigations confirmed the polydispersity of the prepared emulsions. Furthermore, due to further applications of the emulsions i.e. packing and delivery, wetting properties were evaluated. The wetting angle values reached maximum approx. 30° with an HSO content of 1%. However, the wetting angle values were lower with increasing HSO content. Presented results revealed that Sapindus mukorossi is indeed a good stabilizer for hemp seed oil and water emulsions.

Influence of vortex generator on performance of concentrated solar photovoltaic module in existence of heat sink

New configuration of concentrated photovoltaic thermal (CPVT) with the implementation of parabolic concentrator and heat sink combined with the vortex generator (VG) were presented in current work. The testing fluid is water and temperature-dependent features were utilized. The regime of water flow in absence and presence of VG are laminar and turbulent, respectively. Numerical simulations were done for different values of angle of VG (θ = 30°, and 60°), pitch ratio (S = 0.025, 0.0375, and 0.05), and volumetric flow rate (Q = 0.5, to 2 Lit/min). Four values for width of reflector have been applied and radiation model was utilized to derive the absorbed heat flux. The accuracy of modeling has been examined for three cases and good accommodations have been reported. The maximum values of thermal (ηth) and electrical (ηel) performance are 63.75 % and 13.96 % which happens when θ = 30°, S = 0.025, Q = 2 Lit/min. Installing VG leads to increments of ηth and ηel about 1.42 % and 2.74 %. Increase of S and θ cause performance to decrease while this function increases with rise of Q. Increase of Q causes ηth and ηel to increase about 1.17 % and 2.55 % for the best case.

Development of a Biopolymer-Based Anti-Fog Coating with Sealing Properties for Applications in the Food Packaging Sector.

The quest for sustainable and functional food packaging materials has led researchers to explore biopolymers such as pullulan, which has emerged as a notable candidate for its excellent film-forming and anti-fogging properties. This study introduces an innovative anti-fog coating by combining pullulan with poly (acrylic acid sodium salt) to enhance the display of packaged food in high humidity environments without impairing the sealing performance of the packaging material-two critical factors in preserving food quality and consumers' acceptance. The research focused on varying the ratios of pullulan to poly (acrylic acid sodium salt) and investigating the performance of this formulation as an anti-fog coating on bioriented polypropylene (BOPP). Contact angle analysis showed a significant improvement in BOPP wettability after coating deposition, with water contact angle values ranging from ~60° to ~17° for formulations consisting only of poly (acrylic acid sodium salt) (P0) or pullulan (P100), respectively. Furthermore, seal strength evaluations demonstrated acceptable performance, with the optimal formulation (P50) achieving the highest sealing force (~2.7 N/2.5 cm) at higher temperatures (130 °C). These results highlight the exceptional potential of a pullulan-based coating as an alternative to conventional packaging materials, significantly enhancing anti-fogging performance.

Piezoelectric temperature acoustic sensor of LiNbO3 crystal fibers operating at radio frequencies

This study focuses on the growth and characterization of crystalline LiNbO3 (LN) piezoelectric fibers pulled by the Laser Heated Pedestal Growth (LHPG) technique. The electrical properties of the fibers were investigated using an impedance analyzer, which yielded values for resonance frequency, anti-resonance frequency, and phase angle. Subsequently, elastic constants and coupling factor were determined through calculations based on thickness resonance modes. The accuracy of the resonance method was validated through numerical simulations utilizing COMSOL software, demonstrating a close agreement between experimental and simulated results. Additionally, a temperature sensing was conducted, subjecting the fibers to a wide temperature range from 30 °C to 236 °C to assess their sensitivity to temperature variations. The coupling factors of K = 0.37 for LN-1 and K = 0.35 for LN-2 demonstrated efficient performance of the crystalline fibers. Furthermore, the numerical simulations exhibited strong correlation between simulated and experimental data. The sensitivity analysis revealed the potential of LN fibers for temperature sensor applications, exhibiting a sensitivity of −87 Hz.°C−1. These findings underscore the promise of LN piezoelectric fibers in advanced sensing technologies.

In-situ grown ZnO-nanorods of slippery liquid-injected porous surface coating on Mg alloy with hydrophobic, durable, and anti-corrosion properties

In this work, an in-situ self-grown nano-ZnO/epoxy-based slippery lubricant liquid-injected porous surface (SLIPS) coating with a unique bilayer structure is reported to achieve robustness, hydrophobicity, and anti-corrosion properties. Dense epoxy coated ZnO nanoparticles are used as the anti-corrosion barrier layer. Self-grown ZnO nanorods provide a robust micro- and nano-rough porous structure. The lubricant perfluoropolyether (PFPE) is strongly locked into the porous structure via low surface energy material pretreatment and capillary effect. This SLIPS coating has a high water contact angle (WCA) value and has excellent repellency to various liquids. The SLIPS surface maintains a high contact angle of more than 115° even after 20 days of immersion in corrosive solutions and withstand the erosion of corrosive solutions with pH = 3. It also has a very low corrosion current density of 8.97 × 10−12 A/cm2 and the Rct (the charge transfer resistance) of optimum SLIPS remained 1.41 × 108 ohm cm2 after 70 days immersion in 3.5 wt% NaCl solution, which is in the same order of magnitude as the initial value. The SLIPS coating with excellent mechanical stability, super-hydrophobicity, anti-fouling, chemical stability, and long-term corrosion resistance performance possesses tremendous application potential in long-term corrosion protection of Mg alloys.

Linear measurements and shape analysis in the calcaneus of selected dog breeds.

The vast array of dog breeds showcases a remarkable diversity that extends to osteological differences. Exploring these morphological distinctions and establishing reference data for various dog breeds are essential steps in comprehending the evolutionary changes that dogs have undergone. In this study, we conducted linear measurements of the calcaneus and performed shape analyses on selected dog breeds to elucidate distinctive characteristics among them. X-ray images of the calcaneus from six different dog breeds-Maltese Terrier, Toy Poodle, Pomeranian, Cavalier King Charles Spaniel, French Bulldog and Golden Retriever-were utilized for this investigation. Radiological images were obtained from a medio-lateral exposure, positioned 30 cm away from the x-ray device. From these images, four linear length measurements and two angle values were extracted. Additionally, a 2D geometric morphometric analysis was conducted using 32 semi landmarks placed on the radiological images. Linear measurements were assessed using ANOVA, while principal component analysis was employed to examine shape variations across all individuals. Shape differences between species were further elucidated through canonical variates analysis. The results revealed that the Golden Retriever exhibited the highest values for linear measurements, while the Pomeranian showed the lowest. Maltese Terriers displayed the highest dorsal calcaneal angle value. Notably, there were significant differences in calcaneal body length among all breeds, except for the Toy Poodle and Cavalier King Charles Spaniel. Moreover, Maltese Terriers exhibited statistically distinct angular measurements compared to other breeds. Principal component analysis unveiled that the first principal component explained 32.69% of the total variation, with the cranial edge of the calcaneal body being closer to the body in individuals with higher values. Shape variations also indicated that Golden Retrievers displayed a broader range of shapes compared to French Bulldogs, which exhibited a more conservative distribution. While there was no clear breed-specific distinction according to the first principal component, Cavalier King Charles Spaniels generally showed lower values. In canonical variates analysis, distinctions in calcaneal shape between species were apparent, with Golden Retrievers, Cavalier King Charles Spaniels and French Bulldogs displaying positive values for the first canonical variates. The highest Procrustes distance was observed between Maltese Terriers and Cavalier King Charles Spaniels. Notably, allometry was found to be statistically insignificant. This comprehensive study utilized both linear and geometric morphometric analyses based on x-ray images, yielding promising results. The integration of imaging systems in veterinary anatomy research presents numerous opportunities for studying animal welfare and health, utilizing various materials such as bones and cadavers. These advancements hold the potential for further enhancing our understanding of animal morphology and well-being.

Visualisation Testing of the Vertex Angle of the Spray Formed by Injected Diesel–Ethanol Fuel Blends

The internal combustion engine continues to be the main source of power in various modes of transport and industrial machines. This is due to its numerous advantages, such as easy adaptability, high efficiency, reliability and low fuel consumption. Despite these beneficial qualities of internal combustion engines, growing concerns are related to their negative environmental impacts. As a result, environmental protection has become a major factor determining advancements in the automotive industry in recent years, with the search for alternative fuels being one of the priorities in research and development activities. Among these, fuels of plant origin, mainly alcohols, are attracting a lot of attention due to their high oxygen content (around 35%). These fuels differ from diesel oil, for instance, in kinematic viscosity and density, which can affect the formation of the fuel spray and, consequently, the proper functioning of the compression–ignition engine, as well as the performance and purity of the exhaust gases emitted into the environment. The process of spray formation in direct injection compression–ignition engines is extremely complicated and requires detailed analysis of the fast-changing variables. This explains the need for using complicated research equipment enabling visualisation tests and making it possible to gain a more accurate understanding of the processes that take place. The present article aims to present the methodology for alternative fuel visualisation tests. To achieve this purpose, sprays formed by diesel–ethanol blends were recorded. A visualisation chamber and a high-speed camera were used for this purpose. The acquired video provided the material for the analysis of the changes in the vertex angle of the spray formed by the fuel blends. The test was carried out under reproducible conditions in line with the test methodology. The shape of the fuel spray is impacted by an increase in the proportional content of ethanol in the diesel and dodecanol blend. Based on the present findings, it is possible to note that the values of the vertex angle in the spray produced by the diesel–ethanol blend with the addition of dodecanol are most similar to those produced by diesel oil at an injection pressure of 100 MPa. The proposed methodology enables an analysis of the injection process based on the spray macrostructure parameters, and it can be applied in the testing of alternative fuels.

Enhancing the performance of flexible pipeline materials through polyethylene of raised temperature resistance (PE-RT) nanocomposites reinforced with reduced graphene oxide

Due to its superior mechanical properties compared to many other materials, reduced graphene oxide (rGO) shows great promise as a filler in polymer matrix nanocomposites. Through experimental investigation, this study explores the influence of rGO on the thermal and mechanical properties of high temperature resistance polyethylene (PE-RT). PE-RT/rGO nanocomposites were prepared by the melting method at 180 °C and screw speed of 100 rpm, with a residence time of 6 min. The results showed that there was an increase in the thermal stability of the nanocomposite at 8 °C. The DSC analysis did not reveal any substantial effect on the melting and crystallization temperatures or the degree of crystallinity of PE-RT; however, the XRD analysis revealed a higher crystallinity index for the sample with lower rGO content. SEM images showed that the GO nanoparticles have a good interface with PE-RT without agglomeration. The water contact angle values increased from 97.5° in the pure matrix to 102° in the nanocomposite, indicating that the nanoparticles increased the hydrophobicity of the material. Permeability assessments for CO2 showed an increase in time-lag of 6.01 hours. The aging test showed that rGO improves the performance of the PE-RT matrix against swelling. Hardness increased from 50 to 57 Shore D with 2.0 wt% rGO. Finally, the incorporation of 1.0 wt% rGO showed an increase in Young's modulus from 329±37 MPa to 419±40 MPa. The results suggest a potential gain in the use of rGO as reinforcement for PE-RT, which is beneficial for riser applications.

Effect of pocket orientation on PVP lubricated hybrid conical journal bearing system

In a MHCJB (multi-recessed hybrid conical journal bearings), the orientation of the pockets affects the oil film pressure dispersion in the clearance space of bearing thereby it affects the performance of bearing system. This article aims to analyse the influence of pocket orientation on the characteristics of MHCJB operating with PVP (piezo-viscous-polar) lubricant. To analyse the effect of pocket orientation, the study considers two configurations of MHCJB with different pocket arrangement. The modified form of Reynolds equation governing the flow of PVP lubricant in MHCJB is numerically solved by using Galerkin’s technique. The results have been computed for the value of semi-cone angle (γ =10o), piezo viscous parameter (α¯pv= 0.0, 0.3) and polar parameter (l¯cs= 0.0, 0.2). The results indicate that pocket orientation-II offers maximum enhancement of 11.77 % in stiffness coefficient (S¯xx) and 2.45 % in damping coefficient (C¯zz). Further, PVP lubricant offers substantial improvement in stability threshold speed.

Improvement of pear slices drying by pretreatments and microwave-assisted convective drying method: drying characteristics, modeling of artificial neural network, principal component analysis of quality parameters

The drying process has been widely used for the preservation of foodstuffs. Among the drying methods, convective drying is frequently preferred. Although frequently used, various techniques need to be developed to overcome the existing disadvantages. The study aimed to enhance the drying and quality parameters of the pear slices by microwave-assisted convective drying and pretreatments (citric acid, ethanol, and ultrasound) and compare thin-layer and artificial neural network modeling (ANN). Microwave-assisted convective drying and pretreatments reduced drying time compared to convective-dried samples. The lowest drying time was obtained from the samples pretreated with 100% ethanol. On the other hand, ANN modeling gave the best prediction results for drying curves. Additionally, L* values decreased, whereas a* and b* values increased after the drying process. The citric acid pretreatment provided the lowest color change. Moreover, chroma values increased; however, hue angle values of the samples decreased compared to the 90.08 value of the fresh samples. An increase in the color intensity and a decrease in the yellowness were observed after drying. Total phenolic content (TPC) and antioxidant activity (AA) were highly affected by drying processes and pretreatments compared to fresh samples. The highest losses of TPC and AA were determined after ethanol and ultrasound after pretreatments. According to PCA results in terms of total phenolic content, antioxidant activity, and color values, ethanol and ultrasound-pretreated samples share a similar plane, while control and citric acid-pretreated samples exhibit a similar arrangement. Additionally, fresh and microwave-assisted convective-dried samples stand apart from each other and the rest of the examples, showcasing a unique positioning. In conclusion, microwave-assisted convective drying and pretreatments had a positive effect on drying time. However, these methods need to be enhanced in terms of quality parameters. Besides, ANN may be suggested for the prediction of the drying process.

Preserving plum perfection: Buckwheat starch edible coating with xanthan gum and lemongrass essential oil

The research focused on the fabrication of composite coatings using buckwheat starch (BS) and xanthan gum (XG) with incorporation of lemongrass (Cymbopogon citratus) essential oil (LEO) with varying concentration (0.75 %, 1.0 % and 1.25 % (w/v). BS was extracted from buckwheat groats (Fagopyrum esculentum) and its physico-chemical characteristics were determined. BS showed spherical and polygonal morphology and its XRD pattern was similar to starch extracted from other cereal sources. The amount of reducing sugar, starch and amylose content in extracted BS were 0.99 ± 0.33 %, 86.32 ± 0.22 % and 21.02 ± 1.89 % respectively, which indicates that BS is a suitable base material for the formation of edible coatings. XG was mixed with BS in different ratios (1:1, 2:1, 3:1 and 4:1) to optimize the best ratio of combination for composite coatings. The coating with a ratio of 2:1 was very smooth and was chosen for incorporation of LEO and the coatings physical, functional, mechanical, thermal and micro-structural characteristics were examined. The coating S5 with 1.25 % (w/v) concentration of LEO showed the best results with least moisture content (MC), minimum water vapor permeability (WVP) and maximum contact angle value. Moreover, the S5 formulation had the highest antioxidant (73.3 %) ability and maximum antimicrobial efficiency with inhibition zones of 22.09 ± 0.06 mm and 28.65 ± 0.14 mm against S. aureus and E. coli respectively. The coatings were then coated on plum fruit, and various parameters like weight loss, pH, shrinkage and TSS were calculated every 4th day during the 20 days of refrigeration period. The coated plums' ripening pace was delayed by the S5 formulation which improved moisture retention, maintained the plums' TSS value and overall pH. Therefore, composite coatings made up of BS, XG and 1.25 % (w/v) can be used as a cost-effective bio-active coating material for plum preservation under refrigeration conditions.

Effect of Anionic Surfactants on the Oil-Water-Rock Interactions by an Improved Washburn Method.

The complex and variable structure of subsurface oil reservoirs as well as the small pore throat size of reservoirs make it extremely important to investigate the effect of oil-water-rock interactions for enhancing oil recovery. In this paper, the powder wettability of oil sand with different polar solvents was investigated using the improved Washburn capillary rise method, and the surface free energy of oil sand was calculated in combination with the OWRK method. In addition, the wettability of anionic surfactants HABS and PS solutions on the surface of oil sand was determined, and it showed that their wetting rates showed different trends after CMC (critical micelle concentration). The C×cosθ value of HABS decreased significantly with increasing concentration, whereas PS showed little changes. This may be related to the aggregate structure formed by HABS on the oil sand surface. Meanwhile, the interfacial free energy between crude oil and oil sand was obtained by crude oil-to-oil sand wetting experiments, and found that the wetting rate of crude oil to oil sand was much lower than that of solvents and surfactants. In combination with the above results and the oil-water interfacial tension (IFT), the oil-water-rock three-phase contact angle and the work of adhesion between the crude oil and the solid were obtained by Young's equation. From the three-phase contact angle results, it can be found that the contact angle values of both HABS and PS are obviously higher than that of the simulated water, and both HABS and PS have the ability to significantly reduce the work of adhesion, which shows a strong ability to strip the oil film on the surface of the solid. The research results of this paper are helpful to understand the oil displacement mechanism of chemical flooding in reservoir pores, which is of great significance for improving oil recovery.

Influence of Abrasive Grit Size on Surface Wettability in Kelempayan (Neolamarckia cadamba) and Petai (Parkia speciosa) Wood Sanding

The environmental implications of sanding processes, including energy consumption and waste generation, are increasingly significant considerations. Therefore, identifying sustainable sanding practices involves finding ways to minimize energy consumption, reduce waste generation, and mitigate environmental impacts while maintaining or improving product quality. The study aimed to assess the impact of grit size on the surface quality of Neolamarckia cadamba and Parkia speciosa wood. Three sanding methods with varying grit sizes a) single stage 100-grit, b) two stage 100+150-grit, and c) three stage with 100+150+180-grit were employed, and surface quality was evaluated using three different liquids (water, oil and formamide) medias. SEM analysis was carried out for every grit size sanded sample of both species. The sanding process has been done 30 times on each surface with a constant force. The measurements are carrying out with a view parallel to the grain. Results showed that surfaces sanded with 100+150+180-grit had lower mean contact angle values for water, oil, and formamide for both Neolamarckia cadamba and Parkia speciosa. The choice of abrasive and grit sequence significantly affects coating absorption time, surface finishing, and wood damage during sanding. Smoother surfaces exhibited higher wettability and absorbency, highlighting the significant influence of sanding on wood surface properties. This study provides valuable insights for bonding and finishing processes in the wood industry, aiming to promote environmentally responsible practices in Malaysia.

ANALYZING THE PROPERTIES OF A COMPOSITE OF PCL-GRAPHITE BY THE INJECTION MOLDING

Coral reefs are vulnerable to several natural phenomena such as ocean warming, acidification, coral diseases, and plastic pollution. In order to tackle these problems, scientists are now working on the development of biocomposites utilizing biodegradable polymers such as polycaprolactone (PCL). Graphite can be used in conjunction with PCL to enhance its characteristics. The work is centered around conducting water absorption experiments on a composite material consisting of PCL and graphite. The investigation employs PCL granular and graphite powdered materials. The materials undergo heating, crushing, and weighing processes to ascertain weight ratios. Next, the mixture is shaped into specimens. The product's shape and distribution of chemical constituents are analyzed using water absorption, hydrophobicity, FTIR, and SEM testing. The findings indicate that the water absorption diminishes as the concentration of graphite powder increases. An alloy containing 10% graphite had the highest water absorption rate. The hydrophobicity test assesses the ability of a specimen's surface to repel water by introducing NaCl droplets and observing droplet production. The contact angle value exhibits a direct correlation with the increase in graphite content. The FTIR study indicates that there are no changes in the functional groups, resulting in a limited connection between the PCL matrix and the graphite filler. The temperature during the injection molding process affects the microstructure of the polymer. Lower temperatures lead to reduced crystallization, whereas higher temperatures result in denser molecular groupings. Graphite is a highly suitable choice for use as a filler in a PCL matrix because of its layered structure, large surface area, and excellent capacity to effectively fill voids within the matrix.

Neutrino mixing model for best-fit values of θ12 and θ13

Recently, the precise observations have yielded values for the neutrino mixing angles, denoted as [Formula: see text] and [Formula: see text]. Therefore, constructing a neutrino mixing model capable of accurately reflecting these measurements is crucial. In this paper, we propose a novel neutrino mixing model similar to the trimaximal mixing model. Unlike the trimaximal model that falls short of concurrently replicating the best-fit values of [Formula: see text] and [Formula: see text], our proposed mixing model has the ability to simultaneously reproduce the best-fit values for both angles.

Effect of trapezoidal louvered winglets on increased heat transfer and exergy in tubular heat exchanger

The effect of inserting a trapezoidal louvered winglet tape (TLWT) into a uniformly heat-fluxed tube on its thermal effectiveness was studied experimentally. The exergy and entropy analyses for turbulent flows, as well as frictional loss and thermal features, were highlighted as key aspects of the experimental finding for the Reynolds number which measured between about 4700 and 30,000. Because fixing baffles to the curved shape of tube wall presented a challenge, the baffles were consequently positioned on double surfaces of a flat tape. Six values of the louver angle (θ1 = 0°, 25°, 30°, 45°, 60°, and 90°) and three values of the relative pitch of winglet (PR = 1.0, 1.5, and 2.0) were employed in the arrangement of TLWTs, with the V-apex oriented upstream (V-up). Each of these had only a fixed height (BR = 0.25) and angle of attack (α = 30°). The winglets were utilized to induce streamwise vortices which can hinder the boundary layer formation, while the louvered openings were adopted to lessen pressure drop without significantly impacting the primary vortices. The experiment results disclosed that the smallest θ1 and PR produced the largest relative friction factor (fR) and NuR, which were about 13.57 and 4.04 times higher, while PR = 1 and θ1 = 45° provide the greatest TEF of about 2.27. The greatest exergy efficiency (ηEx) resulting from the TLWT was reached at θ1 = 0°, but the generation of entropy (S˙g′) dropped with lowering θ1 and Re. A further examination, however, showed that the best scenario with α = 60° and staggered arrays is more desirable since it yields the largest TEF of 2.45 at θ1 = 45° and PR = 1. For the range of parameters under consideration, the Nu and f correlations were additionally established.

Effects of vibration on natural convection in a square inclined porous enclosure filled with Cu-water nanofluid

PurposeThe purpose of this paper is to investigate the effects of gravitational modulation on natural convection in a square inclined porous cavity filled by a fluid containing copper nanoparticles.Design/methodology/approachThe present study uses a system of equations that couple hydrodynamics to heat transfer, representing the governing equations of fluid flow in a square domain. The Boussinesq–Darcy flow with Cu-water nanofluid is considered. The dimensionless partial differential equations are solved numerically using finite difference method based on alternating direction implicit scheme. The cavity is differentially heated by constant heat flux, while the top and bottom walls are insulated. The authors examined the effects of gravity amplitude (λ), vibration frequency (σ), tilt angle (α) and Rayleigh number (Ra) on flow and temperature.FindingsThe numerical simulations, in the form of streamlines, isotherms, Nusselt number and maximum stream function for different values of amplitude, frequency, tilt angle and Rayleigh number, have revealed an oscillatory behavior in the development of flow and temperature under gravity modulation. An increase of amplitude from 0.5 to 1 intensifies the flow stream (from |ψmax| = 21.415 to |ψmax| = 25.262) and improves heat transfer (from Nu¯ = 17.592 to Nu¯ = 20.421). Low-frequency vibration below 50 has a significant impact on the flow and thermal distributions. However, once this threshold is exceeded, the flow weakens, leading to a gradual decrease in heat transfer rate. The inclination angle is an effective parameter for controlling the flow and temperature characteristics. Thus, transitioning the tilt angle from 30° to 60° can increase the flow velocity (from 22.283 to 23.288) while reducing the Nusselt number (from 16.603 to 13.874). Therefore, by manipulating the combination of vibration and inclination, it is founded that for a fixed frequency value of σ = 100 and for increased amplitude (from 0.5 to 1), the flow intensity at inclination of 60° is boosted, and an increase of the heat transfer rate at inclination of 30° is also observed. Convective thermal instabilities may arise depending on the different key factors.Originality/valueTo the best of the authors’ knowledge, this study is original in its examination of the combined effects of modulated gravity and cavity inclination on free convection in nanofluid porous media. It highlights the crucial roles of these two important factors in influencing flow and heat transfer properties.