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ABSTRACT Objective Method Results Conclusion Trial Registration Total hip arthroplasty (THA) is currently one of the most effective treatment methods for end‐stage hip joint disease, and its long‐term effectiveness largely depends on the accurate placement of the acetabular prosthesis. In conventional surgery, the placement of the acetabular prosthesis mainly relies on the surgeon's clinical experience and surgical techniques. To further improve the accuracy of prosthesis placement, a new robotic system for THA is designed. The purpose of this study is to verify the effectiveness and safety of THA assisted by this robotic system.A multicenter, prospective, randomized controlled, superiority study design was adopted with statistical methods of t test and Chi‐squared test. Participants undergoing primary THA have been enrolled in three centers of joint surgery in China since July 17, 2023. Robotic THA was operated in the experimental group, and conventional instruments were used in the control group. The primary outcome is the proportion of anteversion and inclination angles in the safe zone. The secondary outcomes include operation time, WOMAC score, Harris score, SF‐36 health questionnaire, dislocation rate of hip joint, and rates of adverse events and serious adverse events.A total of 138 patients were included in this study. The proportion of both anteversion and inclination angles in the safe zone was 92.2% in the experimental group and 50.8% in the control group, with significant difference (p < 0.01). The average operation time in the experimental group and control group was 116.4 and 80.5 min respectively, with significant difference (p < 0.01). There was no significant difference in WOMAC score, Harris score, and SF‐36 between the two groups (6 ± 2) weeks after operation (p > 0.05). The dislocation rate of hip joint in the experimental group and control group were 3.0% and 1.5%, respectively, without significant difference (p > 0.05). The rate of adverse events and severe adverse events in the experimental group and control group also showed no significant difference (p > 0.05). No adverse events or serious adverse events were judged to be “definitely related” to the experimental instruments.Robotic THA could prolong the operation time within an acceptable range, but more precise acetabular prosthesis positioning could be obtained when compared with conventional surgery. Besides, no significant difference was found in function scores, dislocation rate or other adverse events, which indicates that this new robot system shows both good effectiveness and safety in THA.Clinical Trials: NCT05947734 [ABSTRACT FROM AUTHOR]

An axial flow tubular heat exchanger has been experimentally investigated to augment the heat transfer rate with a novel swirl flow of air past the heated tubes. The novel design has been made on the circular baffle plates provided with trapezoidal air deflectors of various inclination angles α, which is the angle made by the deflector surface with baffle plane. The arrangement of tubes, which were supported on baffle plates, was kept the same throughout the experiment analogy with the peripheral longitudinal air flow directed on it. All the tubes were maintained at constant heat flux condition over the entire surface. There were four deflectors developed on each of the baffle plate each deflector with equal inclination angle which generates air swirls inside the circular duct carrying the heated tubes that increase air side turbulence and hence the surface heat transfer rate. For every Re the baffle plates were placed equidistant from each other at different pitch ratios (PR = 0.6, 0.8, 1.0, and 1.2). The Reynolds number Re was kept in the range of 93 500–160 500. The effect of pitch ratios and the inclination angles on the thermo-fluid performance of the heat exchanger has been studied. The investigations reveal an average improvement of 25.1% in the thermo-fluid performance for a heat exchanger provided with the deflector baffle plates (DBP) having an inclination angle of 50° and a pitch ratio of 1.2 compared to that of a heat exchanger with a segmental baffle plate (SBP) tested under similar conditions of operation. [ABSTRACT FROM AUTHOR]

Bottlenecks inherent in batch and column adsorption configurations have impeded the implementation of the adsorption technique in large-scale wastewater treatment systems. This study mainly aimed to develop an innovative wastewater treatment prototype that integrates inclined plate settlers (IPS) and composite adsorbent coating (CAC). The objective is to enable the removal of Cd2+ from aqueous solutions in a continuous setup, thereby enhancing its practicality for large-scale applications. The combined IPS-CAC system was optimized at various angle of inclination (θ), influent flow rate (Q) and adsorbate initial concentration (Co) using the Box–Behnken Design (BBD) of the Response Surface Methodology (RSM). At optimized operating parameters (θ = 45°, Q = 5 ml/min and Ci = 1.87 mg/L) the IPS-CAC Cd2+ predicted (R2 = 0.9926) and experimental removal efficiencies were 75.8% and 69.7 ± 4.67%, respectively. The IPS-CAC breakthrough adsorption capacity was 9.6 mg/g. Comparing IPS-CAC performance with a tank without plates and IPS with plain plates, the Cd2+ removal efficiencies were 2.4 ± 0.1% and 4.6 ± 1.1%, respectively, confirming the synergistic effect of IPS and CAC. Additionally, breakthrough curves were acquired for various flow rates, cadmium influent concentrations, and plate inclination angles. Only a 10% decline in the removal effectiveness (from 69.7 to 59.7%) of the CAC after three adsorption–regeneration cycles was observed, indicating its stability for heavy metal removal. The results underpin the potential of using IPS-CAC for industrial wastewater treatment and enhancing the use of adsorption on a larger scale. [ABSTRACT FROM AUTHOR]

Abstract Bottlenecks inherent in batch and column adsorption configurations have impeded the implementation of the adsorption technique in large-scale wastewater treatment systems. This study mainly aimed to develop an innovative wastewater treatment prototype that integrates inclined plate settlers (IPS) and composite adsorbent coating (CAC). The objective is to enable the removal of Cd2+ from aqueous solutions in a continuous setup, thereby enhancing its practicality for large-scale applications. The combined IPS-CAC system was optimized at various angle of inclination (θ), influent flow rate (Q) and adsorbate initial concentration (C o) using the Box–Behnken Design (BBD) of the Response Surface Methodology (RSM). At optimized operating parameters (θ = 45°, Q = 5 ml/min and C i = 1.87 mg/L) the IPS-CAC Cd2+ predicted (R 2 = 0.9926) and experimental removal efficiencies were 75.8% and 69.7 ± 4.67%, respectively. The IPS-CAC breakthrough adsorption capacity was 9.6 mg/g. Comparing IPS-CAC performance with a tank without plates and IPS with plain plates, the Cd2+ removal efficiencies were 2.4 ± 0.1% and 4.6 ± 1.1%, respectively, confirming the synergistic effect of IPS and CAC. Additionally, breakthrough curves were acquired for various flow rates, cadmium influent concentrations, and plate inclination angles. Only a 10% decline in the removal effectiveness (from 69.7 to 59.7%) of the CAC after three adsorption–regeneration cycles was observed, indicating its stability for heavy metal removal. The results underpin the potential of using IPS-CAC for industrial wastewater treatment and enhancing the use of adsorption on a larger scale.

This study evaluates the analysis of round inserts (Fixed and Self-Propelled Rotary Tools) when machining hardened steel. Self-propelled rotary Tools (SPRTs) exploit the entire perimeter of the insert rather than a specific cutting edge, minimizing insert wear and maximizing insert life. It is considered an environmentally friendly process. Tool and insert geometry have a direct effect on the surface roughness. Previous studies highlighted the significant effects of one inclination angle on surface roughness. Despite previous research that investigated only one inclination angle, in this research, the effect of both inclination angles has been investigated, and a new method for simultaneous application has been used. The optimal use of both inclination angles has significantly improved the quality of the machined surface. Therefore, an optimal holder has been designed and fabricated based on the cutting forces and component shapes, allowing inclination angle changes. The full factorial design of the experiment is adopted, and the effects of the horizontal and vertical inclination angles and feed rate in fixed tool and SPRT turning have been evaluated, each in 3 levels with a total of 54 experiments. The equivalent insert radius is defined using the inclination angles and an analytical model is developed concerning the equivalent insert radius to predict surface roughness. The proposed model accurately estimated roughness in fixed tool turning for an R-square of 0.81 and 0.76 for SPRT turning. In the best condition, the surface roughness has been measured at 0.472 μm in the fixed tool turning and 0.409 μm in SPRT turning.

Abstract To gain insights into the spatial distribution of non-penetrating cracks during the rock fracture process, a comprehensive uniaxial compression test is conducted on cubic gypsum specimens (100 mm × 100 mm × 100 mm) containing two non-penetrating cracks. The two pre-formed cracks are rectangular, with dimensions of 25 mm length, 2 mm width, and depths of 80 mm and 35 mm on adjacent sides of the specimen. The depth of the 80 mm crack can be adjusted from 0° to 150° in increments of 30°, while the other is fixed at a 45° angle. The results show that the spatial distribution of non-penetrating cracks can significantly influence the strength of the specimen. Initially, the strength of the specimen exhibits an upward trend and subsequently declines as the pre-crack inclination angle of the main rupture plane increases, ultimately reaching its pinnacle at 90°. The total percentage of tensile cracks in specimens with different inclinations are found to be 57%, 57%, 63%, 77%, 68%, and 61%, respectively. This change aligns seamlessly with the fluctuation in specimen strength as influenced by the angle of inclination. Non-penetrating cracks can also induce spalling on the specimen surface and give rise to anti-wing cracks, thereby exacerbating the spalling on the specimen surface. The inclinations of non-penetrating cracks can inevitably exert a certain influence on the propagation of neighboring non-penetrating cracks. Additionally, the macro-scale shear fracture of the specimen often occurs on the side of the non-penetrating crack that is deeper. The curved tensile fracture surface formed by the extension of the non-penetrating crack bears resemblance to the non-penetrating region in its ability to somewhat restrain the propagation of new cracks. Even under uniaxial compression, the spalling surface of the specimen containing spatial non-penetrating cracks frequently exhibits fracture characteristics belonging to I-III mode fracture, while its interior may display characteristics belonging to I-II-III mode fracture. These findings hold significant implications for comprehending and elucidating the genuine fracture process and three-dimensional fracture theory of rocks.

Most natural sandy deposits contain low amounts of fine content (< 10%), which is usually anisotropic and characterized by complex microstructures. The present study investigates the influence of low silt content on the anisotropic behaviour of sand. For this purpose, 30 undrained tests were performed using a hollow cylindrical apparatus with constant α° and b values on Firoozkuh sand. The specimens had silt contents of 0, 3, 5, 7 and 10%, and the inclination angle (α°) was varied from 15° to 60°. The specimens were prepared with the dry deposition method and subjected to confining pressures of 100 and 200 kPa. The equivalent intergranular relative density parameter was then introduced in order to create a comparative basis for the specimens. The experimental results show that increasing α leads to more contractive behaviour in the pure sand. By adding silt particles to the host sand up to 5%, the peak strength of the specimen is increased (18.5%, 12% and 7.7% for α = 15°, 30° and 60°, respectively), and the strength of the specimen is decreased. It should be noted that with a silt content of 10%, the strength of the specimen was lower than that of the host sand (about 12%). On the other hand, it can be seen that with the increase of α, the influence of fine grains as an important parameter in sand-fine mixtures is decreased. [ABSTRACT FROM AUTHOR]

As one the most important recovery mechanisms of steam‐assisted gravity drainage (SAGD), gravity drainage is largely dependent on the inclination angle of the steam chamber edge. The existence of solution‐gas causes an ellipsoid‐shaped chamber that has small inclination angle at the bottom, which leads to inefficient gravity drainage and slows down oil production. To address this problem, this study proposes a new scheme, variable‐pressure SAGD (VP‐SAGD). It is basically a SAGD process, at certain stages of which pressure surge is induced by controlling the operating conditions so that the shape of steam chamber can be altered. This leads to a larger slip angle in the steam chamber at the bottom and more efficient heat transport between hot steam and crude oil. Results show that VP‐SAGD is able to increase oil recovery by up to 20% and decrease cumulative steam–oil ratio (cSOR) by up to 7%. Its special oil extraction mechanisms include swabbing effect, enlarged inclination angle of steam chamber boundary at the bottom, and enhanced heat transfer. Particularly, the inclination angle is increased by up to 40%. In addition, a lower producer bottom‐hole pressure (BHP) during pressure drawdown leads to a better production incremental in later stages. The optimal timing for pressure surge is the middle stage of steam chamber growth. The lower the producer BHP decrease, the better the yield increase. Moreover, The VP‐SAGD strategy works better in heavy oil reservoirs with a permeability of k = 0.5–10 Darcy or solution gas content of greater than 2%. [ABSTRACT FROM AUTHOR]

A study investigated how a new swirl airflow design could impact the heat transfer rate in a tubular heat exchanger with axial flow. A perforated conical baffle plate with rectangular air deflectors of different inclination angles was created to generate a swirl flow. The tubes in the heat exchanger were aligned longitudinally, and the heat flux across their surface was kept constant. Each plate had four deflectors with equal deflector angles and adjustable pitch ratios, which created a swirling airflow inside the circular duct containing the heated tubes. This increased turbulence and the rate of heat transfer across the tube surface. The Reynolds number stayed within the range of 93,500 to 160,500. The result indicates that the inclination angle and Pitch ratio profoundly impact the Nusselt number, while the pitch ratio has a greater effect on the friction factor. Furthermore, the conical baffle plate design resulted in an average improvement of 2.51 in thermal efficiency compared to a segmental baffle design with a deflector angle of 30° and a pitch ratio of 1, all under similar Reynolds number, pitch ratio, and blockage ratio conditions. [ABSTRACT FROM AUTHOR]

This experimental investigation aimed to analyze the impact of a unique design of swirl generator airflow on the performance of a tubular heat exchanger operating with axial flow. To conduct the experiment, we utilized a custom‐built apparatus containing eight sawtooth air deflectors with differing space height ratios (e/h). These deflectors were oriented in a uniform manner (shutter type) and positioned at various inclination angles. Circular baffle plates, housing these deflectors, were equidistantly spaced at different pitch ratios. The arrangement of tubes within the heat exchanger remained constant throughout the study, while the Reynolds number ranged from 16,000 to 30,000. In addition, a consistent heat flux condition was maintained on the surface of the tubes. The research outcomes indicated that incorporating a deflector baffle plate with an inclination angle of 30°, an e/h ratio of 0.4, and a pitch ratio of 1.2 led to an average increase of 1.36 in the thermal enhancement factor when compared to a heat exchanger lacking a baffle plate, tested under similar conditions. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effect of heat load, tilt angle, and volume concentration of alumina nanofluid on the thermal performance enhancement of cylindrical screen mesh wick heat pipe in terms of thermal resistance(R) and thermal conductivity(k). Response surface methodology based on the Box–Behnken design was implemented to investigate the influence of heat input (100–200 W), tilt angle (0–90°), and volume concentration (0.05–0.25 vol%) of nanofluid as the independent variables. Second-order polynomial equations were established to predict the responses, 'R', and 'k'. The significance of the models was tested by means of analysis of variance (ANOVA). In addition, a correlation between the independent variables was derived in this study. The results revealed that the optimum heat input, inclination angle, and concentration of nanofluid were determined as 200 W, 52.72°, and 0.1773 vol. % respectively for both 'R' and 'k'. SEM analysis was performed to observe the thermal performance phenomena of the heat pipe before and after experimentation. [ABSTRACT FROM AUTHOR]

To explore the effects of fracture inclination angle θ and confining pressure c3t on the slip behaviors and friction properties of fractures, the triaxial unloading-induced slip experiments were performed on the shale fractures. The results show that the σ3t controls the slip modes of fractures, while the θ affects the occurrence of the stick-slip events during the quasi-static slip stage. With the increase in σ3t, the main slip modes of fracture transform from the stable-slip to stick-slip, and eventually to the creep-slip. The increase in θ facilitated the occurrence of stick-slip events. As the θ increased from 30° to 50°, the number of stick-slip events increased from 0 to 3 and from 2 to 4 for σ3t = 10 MPa and 20 MPa, respectively. For σ3t = 40 MPa, no stick-slip event occurred in the slipping process. The θ and σ3t have great effects on interaction modes between asperities, which directly affected the friction properties of fractures. With increasing σ3t, the void spaces between the asperities were further compacted, resulting in the transition of asperity interaction from overriding mode to shear-off mode. The transition of asperity interaction model therefore brought about the weakening of friction coefficient at the activation point and the onset of dynamic slip stage. There is a competitive relationship between the θ and a3t for the evolution of the friction properties of fractures. As the θ increase from 30° to 50°, for σ3t = 10 MPa, the mean sheared-off thickness decreased from 0.502 mm to 0.433 mm, while for σ 3t = 40 MPa, the mean sheared-off thickness decreased from 0.505 mm to 0.319 mm. With the increment of θ, the anisotropy of joint roughness coefficient was weakened. We suggested that by adjusting the fracturing angle of hydro-fracturing, the earthquakes with large seismic moments may be effectively mitigated. [ABSTRACT FROM AUTHOR]

AbstractThis work considers the peristaltic flow of non-Newtonian Prandtl-Eyring fluid via a duct having an elliptical cross-section. The elliptic conduit is taken inclined with horizontal. The mathematical model of the problem is converted into non-dimensional form using dimensionless variables with the assumptions of long wavelength approach. The perturbation approach and polynomial solutions are incorporated to solve the mathematical model analytically. The analytically achieved results are analyzed and presented using graphical representation of several physical parameters. The impact of different physical parameters on velocity, temperature, pressure gradient, and pressure rise is studied graphically. The Grashof number is found to have a significant impact on the pressure gradient and velocity profile. The flow characteristics (velocity and pressure gradient) are observed to be more prominent for the vertical channel than the horizontal and inclined conduit. The velocity profile showed a parabolic nature and achieved high values at the center of the conduit and progressively lowered near the wall of the conduit. [ABSTRACT FROM AUTHOR]

The flow of boundary layer over porous wedge nanofluids, hybrid nanofluids, and ternary hybrid nanofluids under constant transverse magnetic field and heat radiation have all been examined. The following cases are taken into consideration: Zirconium oxide + A A7072 + Polyethylene Glycol-water (Case-2); Magnesium oxide + Polyethylene Glycol-water + AA7072 + Zirconium oxide (Case-3); Polyethylene-water as base fluid; nanofluid, hybrid nanofluid, ternary hybrid nanofluid cases. The governing equations are solved using the shooting technique with the fourth-order Runge-Kutta method. The approximate relationship between temperature, velocity, heat transfer rate, and friction factor coefficient at the wedge is shown graphically for a range of values of the pertinent parameters. The flow of boundary layer over porous wedge nanofluids, hybrid nanofluids, and ternary hybrid nanofluids under constant transverse magnetic field and heat radiation have all been examined. Cases containing Polyethylene Glycol-Water + AA7072 (Case-1), Zirconium oxide + A A7072 + Polyethylene Glycol-water (Case-2), and Magnesium oxide + Polyethylene Glycol-water + AA7072 + Zirconium oxide (Case-3) are taken into consideration. Polyethylene water is used as the base fluid. The governing equations are solved using the shooting approach and Runge-Kutta fourth order. The approximate relationship between temperature, velocity, heat transfer rate, and friction factor coefficient at the wedge is shown graphically for a range of values of the pertinent parameters. Comparing Ternary hybrid nanofluid to nanofluid and hybrid nanofluid situations, it is discovered that the skin friction coefficient is higher. It has also been noted that ternary hybrid nanofluids have a higher Nusselt number than hybrid and nanofluids. When applied to specific dimensionless parameters, the basic linear regression machine learning technique using the gradient descent method accurately predicts the truth values. Finding the optimisation conditions values based on the key factors influencing the Response Function is easier with the RSM method's help. When applied to specific dimensionless parameters, simple linear regression machine learning using the gradient descent method accurately predicts the truth values.

Simultaneously guaranteeing material removal accuracy and surface quality of robotic grinding is crucial. However, existing studies of robotic grinding process optimization have mainly focused on a single indicator that solely considers contour error or surface roughness, while studies that simultaneously investigate the impact of contact force, spindle speed, feed rate, inclination angle, and path space on the material removal profile (MRP) and the surface roughness are lacking. This paper proposes a hybrid optimization method that considers dimensional accuracy and surface quality constraints. First, an MRP model that considers the coupling influence of the contact force, spindle speed, feed rate, and inclination angle is presented. Then, a surface roughness model that considers the inclination angle is established. Finally, the contact force, feed rate, inclination angle, and path space are simultaneously optimized to satisfy the hybrid constraints of MRP accuracy and surface roughness. The proposed method ensures maximum grinding efficiency while satisfying dimensional accuracy and surface quality constraints. The proposed method is verified on an industrial robotics grinding system with a pneumatic force-controlled actuator. The results show that the proposed method has higher profile accuracy and lower surface roughness than traditional methods. [ABSTRACT FROM AUTHOR]

An experiment was conducted to analyze a tubular heat exchanger's turbulent heat transfer characteristics. The heat exchanger was equipped with a newly designed perforated (rectangular) conical baffle plate consisting of two rectangular opposite-oriented flow deflectors with adjustable tilt angles. The baffle plate was installed at the entrance of the heat exchanger, resulting in a counter-swirling flow pattern downstream. Three baffle plates were installed along the flow direction with different pitch ratios (spacing between baffle plates divided by the diameter of the heat exchanger). The experiment examined the effects of pitch ratio (ranging from 0.6 to 1.2), deflector tilt angle (ranging from 30° to 50°) and Reynolds numbers (ranging from 16 500 to 30 000) on the heat transfer performance. The results showed that the pitch ratio and tilt angle significantly affected the performance of the heat exchanger. In particular, a configuration with a tilt angle of 30° and a pitch ratio of 1 resulted in an average improvement of 26.9% in the heat exchanger's performance compared to a heat exchanger without a conical baffle plate under similar operating conditions. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the heat transfer (HT) properties of a tubular heat exchanger (HX) by using innovative baffle plate arrangements. The newly designed baffle plate was circular with triangular openings and adjustable triangular flow deflectors. These deflectors were strategically placed at the inlet of the HX to create a swirling flow downstream. Three baffle plates were installed along the flow direction with different length‐to‐diameter ratios (pitch ratios) to assess their impact on HT, pressure drop, and thermal enhancement factor. The study compared these results with a smooth channel under varying Reynolds numbers (16,500–29,500). The findings revealed that both the pitch ratio (0.6–1.2) and the inclination angle of the deflectors (30⁰–50⁰) significantly affected the HX's performance. Notably, the baffle plate with a deflector inclination angle of 30° and a pitch ratio of 1 showed a remarkable average improvement of 36.5% compared to other angles and ratios. [ABSTRACT FROM AUTHOR]

An exploratory investigation was conducted to analyze a tubular heat exchanger's turbulent heat transfer characteristics using an innovative baffle plate design. The design incorporated a perforated conical baffle plate and an adjustable rectangular deflector. The strategic placement of this baffle plate at the heat exchanger inlet facilitated a swirling flow downstream. To assess the impact of this design, three baffle plates with varying pitch ratios (l/D) were positioned in the direction of the flow. The study examined the effects of pitch ratio (ranging from 0.6 to 1.2), deflector inclination angle (ranging from 30° to 50°), and Reynolds numbers (ranging from 16,500 to 29,500). Moreover, the size of the conical baffle plate (H/D) was altered (from 0.25 to 0.15). The findings highlighted the substantial influence of pitch ratio, inclination angle, and height ratio on the heat exchanger's performance. Notably, the configuration featuring an inclination angle of 50° and height ratio of 0.15 exhibited an average performance improvement of 22% compared to other height ratios, inclination angles, and pitch ratios. [ABSTRACT FROM AUTHOR]

In the present study, multiscale finite element (FE) models of half-through steel basket-handle arch bridges were established. The eigenvalue analyses were conducted to explore the dynamic characteristics of the arch bridges based on the FE models. In addition, a parametric analysis was carried out to investigate the impact of the inclination angle of the arch rib (0°, 4°, and 7°) on the longitudinal and transverse seismic performances of arch bridges. The results show that with the increase in inclination angle, the out-of-plane stiffness of half-through steel basket-handle arch bridges increases, resulting in the natural period of the structure becoming shorter from 3.09 s to 2.93 s. Adjusting the inclination angle appropriately has a beneficial impact on the overall seismic performance of the structures, affecting both displacement and internal forces, in which the most significant improvements include a 42.8% decrease in displacement and a 62.6% reduction in internal forces. Adjusting the inclination angle can cause the arch springing and transverse brace to undergo larger plastic deformation. It is advisable to judiciously enlarge the sectional dimensions and enhance the material strength of both the arch springing and the transverse bracing in seismic designs. [ABSTRACT FROM AUTHOR]

The specific heat capacity of working fluid is an important influence factor on heat transfer characteristic of the pulsating heat pipe (PHP). Due to the relatively large specific heat capacity of micro encapsulated phase change material (MEPCM) suspension, a heat transfer performance experimental facility of the PHP was established. The heat transfer characteristic with MEPCM suspension of different mass concentrations (0.5% and 1.0%) and ultra-pure water were compared experimentally. It was found that when the PHP uses MEPCM suspension as its working fluid, operating stability is impoverished under lower heating power and the operating stability is better under higher heating power. At the inclination angle of 90°, the temperature at heating side decreases compared to ultra-pure water and the temperature at heating side decreases with the raising of MEPCM suspension mass concentration. The heat transfer characteristic of the PHP is positively correlated with the inclination angle and the 90° is optimum. The unfavorable effect of the inclination angle decreases with heating power increasing. When the inclination angle is 90°, the PHP with MEPCM suspension at 1.0% of mass concentration has the lowest thermal transfer resistance and followed by ultra-pure water and MEPCM suspension at 0.5% of mass concentration has the highest thermal transfer resistance. When the inclination angles are 60° and 30°, the effect of gravity on the flow direction is reduced to 86.6% and 50% of that on the inclination angle of 90°, respectively, and the promoting effect of gravity on the working fluid is further weakened as the inclination angle further decreases. Due to the high viscosity of MEPCM suspension, the PHP with ultra-pure water has the lowest heat transfer resistance. When the inclination angles is 60°, the thermal resistance with MEPCM suspension at 0.5% of the mass concentration is lower than that at 1.0% at the heating power below 230 W. The thermal resistance of MEPCM suspension tends to be similar for heating power of 230–250 W. At the heating power above 270 W, the thermal resistance with MEPCM suspension at 1.0% of the mass concentration is lower than that at 0.5%. [ABSTRACT FROM AUTHOR]

To explore the effects of fracture inclination angle θ and confining pressure σ3t on the slip behaviors and friction properties of fractures, the triaxial unloading-induced slip experiments were performed on the shale fractures. The results show that the σ3t controls the slip modes of fractures, while the θ affects the occurrence of the stick-slip events during the quasi-static slip stage. With the increase in σ3t, the main slip modes of fracture transform from the stable-slip to stick-slip, and eventually to the creep-slip. The increase in θ facilitated the occurrence of stick-slip events. As the θ increased from 30° to 50°, the number of stick-slip events increased from 0 to 3 and from 2 to 4 for σ3t = 10 MPa and 20 MPa, respectively. For σ3t = 40 MPa, no stick-slip event occurred in the slipping process. The θ and σ3t have great effects on interaction modes between asperities, which directly affected the friction properties of fractures. With increasing σ3t, the void spaces between the asperities were further compacted, resulting in the transition of asperity interaction from overriding mode to shear-off mode. The transition of asperity interaction model therefore brought about the weakening of friction coefficient at the activation point and the onset of dynamic slip stage. There is a competitive relationship between the θ and σ3t for the evolution of the friction properties of fractures. As the θ increase from 30° to 50°, for σ3t = 10 MPa, the mean sheared-off thickness decreased from 0.502 mm to 0.433 mm, while for σ3t = 40 MPa, the mean sheared-off thickness decreased from 0.505 mm to 0.319 mm. With the increment of θ, the anisotropy of joint roughness coefficient was weakened. We suggested that by adjusting the fracturing angle of hydro-fracturing, the earthquakes with large seismic moments may be effectively mitigated.

The present study focuses on the manifestation of the Doppler effect in low‐Earth orbit (LEO) satellite constellations with laser inter‐satellite links (LISLs). In this letter, the LEO satellite constellation parameters that influence the variation of the Doppler effect in LISLs are presented. The LEO satellite constellation configurations that perform LISLs with less possible Doppler effect could be designed based on the tendency of the Doppler wavelength shift (DWS) as a function of the LEO satellite constellation's parameters. The paper presents the main LEO satellite constellation parameters that involve the variation of the Doppler effect, such as the altitude of the satellites, the orbital plane number within the constellation, and the inclination angle of the orbital plane. In addition to the operating laser wavelength that is employed as a data carrier. These parameters could be helpful to control the Doppler effect in LISL before building an LEO constellation. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to establish a thermal contact conductance model of rough surfaces with inclination based on three-dimensional fractal theory. Design/methodology/approach: The effects of contact load, inclination angle, fractal dimensional and fractal roughness on thermal contact conductance of rough surfaces were studied using numerical simulation. Findings: The results show that the thermal contact conductance of the rough surface increases with the increase of contact load and fractal dimension and decreases with the increase of fractal roughness and inclination angle. The inclination angle of the rough surface has an important influence on the thermal contact conductance of the rough, and it is a factor that cannot be ignored in the study of the thermal contact conductance of rough surfaces. Originality/value: A thermal contact conductance model of rough surfaces with inclination based on three-dimensional fractal theory was established in this study. The achievements of this study provide some theoretical basis for the investigation of the thermal contact conductance of rough surfaces. [ABSTRACT FROM AUTHOR]

The influence of oriented magnetic field on the incompressible and electrically conducting flow is investigated in a square cavity with a moving top wall and a noslip constricted bottom wall. Radial basis function (RBF) approximation is employed to velocity-stream function-vorticity formulation of MHD equations. Numerical results are shown in terms of streamlines for different values of Hartmann number M, orientation angle of magnetic field θ and the height of the constricted bottom wall hc with a fixed Reynolds number. It is obtained that the number of vortices arises as either hc or M increases. However, the increase in θ leads to decrease the number of vortices. Formation of vortices depends on not only the strength and the orientation of the magnetic field but also the constriction of the bottom wall. [ABSTRACT FROM AUTHOR]

The overall performance of PV-PCM integrated with rectangular straight fins is analysed by threedimensional transient numerical simulations. The influence of fin lengths, number of fins (n), and inclination (1) of the system is investigated and compared with the PV-only system, and an optimal system configuration is then identified. Finite element analysis is used to conduct the simulations using COMSOL Multiphysics 6.0. The PV front surface is subjected to a constant flux of 1000 W/m2 for 180 min, and the PCM employed is RT25HC. The results indicate that the average PV temperature tends to drop with increasing inclination and fin length, thereby enhancing the PV efficiency, with maximum improvement attained for the full fin case for a given inclination and number of fins. Compared to the PV-only system, the highest PV temperature reduction and PV efficiency enhancement are 59.65 °C and 45.1%, respectively, for the horizontal system of full-length fins with a number of fins equal to 6. The full-fin PV-PCM system with 6 fins and 45° inclination gives the highest instantaneous power output of 14.16 W. The melting rate of PCM is strongly related to the heat transfer rate inside PCM, and the lowest melting time is obtained for the 8-finned PV-PCM system with = 45°. The peak velocity magnitude for all systems with different fin lengths is also examined to analyse the extent of convection levels within PCM. [ABSTRACT FROM AUTHOR]

In this paper, a series of comparative experiments were performed to study the upward flame spread over single and adjacent twin polyethylene-insulated copper wires from horizontal (0°) to vertical (90°). The flame morphology and flame spreading rate of single and twin wires were compared at different inclination angles, which show a larger flame size, but a lower overall flame spread rate over twin wires. As the inclination angle increases, the flame characteristic length, and flame spread rate increase with the inclination angle for both wire arrangements. The flame spreads steadily to the end of the sample without molten dripping or sliding for single-wire conditions. However, molten dripping or sliding behaviors were found during flame spreading for twin-wire conditions, and the averaged dripping or sliding frequency increases with the inclination angle. Correspondingly, the periodical variation of flame characteristic length, flame height, and flame spread rate for twin-wire conditions have been investigated in detail compared with single-wire conditions. Finally, a simplified heat transfer analysis is carried out to quantitatively study the flame spread rate for both wire arrangements, and the effects of molten dripping/sliding and overlapped area on the heat transfer and flame spread rate are qualitatively discussed. [ABSTRACT FROM AUTHOR]

Background: Our aim is to investigate the acetabular component positioning using TAL & its functional outcomes in primary THA as assessed by modified Harris Hip Score (mHHS). Materials and Methods: 30 patients were selected randomly in this prospective study after getting clearance from the research and ethical committee in a Tertiary care centre in North India. All Total Hip Arthroplasty surgeries were performed using direct lateral Hardinge's approach & used TAL was used as the guide for positioning the acetabular cup. Acetabular version and inclination were assessed using a CT scan and functional outcome was evaluated using mHHS. Results: The mean absolute position of the acetabular cup in our study population included 15.3±5.85 degrees of anteversion and 42.7±5.31 degrees of inclination angle. 86.67% of patients had both acetabular version and inclination within Lewinnek's "safe zone" with only a single case of postoperative dislocation. The correlation between the cup version and mHHS was significant (p-value=0.028) whereas the correlation between acetabular inclination and mHHS was insignificant (p-value=0.29. Conclusion: TAL is a reliable, inexpensive and patient-specific intra-operative anatomical landmark for the placement of acetabular components with efficacy comparable to that of a mechanical alignment guide (MAG). [ABSTRACT FROM AUTHOR]

This investigation is focused on the effect of inclination angle with respect to the horizontal of a hydrophobic silicone insulation, on the rate of its creepage distance's wetting by natural rain. The constellation of rainwater drops obtained on the de-energized site is then reproduced in the laboratory, to quantify the effect of their volume on the humidification intensity of the inclined insulation's creepage distance, and therefore its electrical performance under different alternating voltage levels. For this purpose, two different experimental devices allowing the variation of the insulation's inclination angle were set-up. The first one is dedicated to the on-site display of silicone samples in natural rain. The second one allows the study of the applied voltage's effect on the wetting degree of the insulation's surface. All the performed tests were supported by camera visualization. On-site measurement results show a decline in the length of the creepage distance of the natural rain-wetted insulation with increasing its inclination angle. Laboratory results also show a decrease in the size of the insulation's wet surface with increasing its inclination angle. These two characteristics reveal two different intervals of critical inclination angles of the insulation, unfavorable and favorable, for the dimensioning of the insulators' sheds corresponding respectively to their minimum and maximum electrical performance. [ABSTRACT FROM AUTHOR]

Experimental analysis was conducted to investigate the turbulent heat transfer behaviors within a tubular heat exchanger, incorporating a novel baffle plate design. The new design includes a perforated circular baffle plate with a rectangular flow deflector that can be adjusted to different inclination angles. The baffle plate is strategically positioned at the entrance of the heat exchanger, resulting in a swirling flow downstream. To assess the impact of the baffle plate design, three baffle plates were placed longitudinally along the flow, with varying pitch ratios (l/D). The effects of pitch ratio (ranging from 0.6 to 1.2), deflector inclination angle (ranging between 30° to 50°), and Reynolds numbers (ranging between 16000 to 29000) were examined. The outcomes highlighted the substantial impact of pitch ratio and inclination angle on the thermal enhancement factor. In particular, compared to single segmental baffle plates working under similar operating conditions. The result indicates that an inclination angle of 30° and a pitch ratio of 1 exhibited an average 41.49% augmentation in thermal-fluidic performance compared with an exchanger with a segmental baffle plate. [ABSTRACT FROM AUTHOR]

Various engineering applications, such as heat exchangers, air conditioning systems, chemical reactors, and refrigeration systems, make use of enhanced heat transfer surfaces. Numerous methods have been explored to improve heat transfer rates and reduce the size and cost of equipment involved, particularly in heat exchangers. This review comprehensively assesses multiple continuous and discrete swirl-inducing techniques for enhancing heat transfer, achieved through geometry alterations or flow deflectors. The study showed that all angles of the swirl-inducing device effectively promoted fluid mixing, reduced thermal boundary layers, and created turbulent eddies due to swirl flows and vortices. While solid swirl flows may impede local heat transfer performance by trapping low-velocity heated fluids within thermal boundary layers, as these flows move downstream, they lead to improved fluid mixing, enhancing heat transport over large areas. This paper explores the application of other techniques for specific work environments.

Shale reservoirs, characterized by their relatively low permeability and porosity, often employ hydraulic fracturing techniques to increase production during development. However, conventional large-scale hydraulic fracturing encounters challenges such as excessive water consumption, low flowback rates, and environmental concerns. Given the increasing scarcity of water resources and increased emphasis on sustainability environmental sustainability, hydraulic fracturing no longer meets the requirements for green and environmentally friendly extraction. The utilization of supercritical CO2 fracturing technology emerges as a promising alternative, offering advantages such as reduced water usage and minimized environmental impact. Additionally, this technology allows for the sequestration of CO2 underground, presenting an integrated approach to CO2 geological storage and oil-gas extraction. Supercritical CO2 possesses many unique physical and chemical properties. However, the micro-mechanisms governing its interaction with rock during fracturing, along with the mechanisms and propagation characteristics of fracture initiation, necessitate further in-depth investigation. This study aims to explore the development mechanisms of supercritical CO2 fractures under the influence of single factor variables and natural fractures of different sizes (2 m, 4 m, and 6 m). To explore the interaction mechanisms between natural fractures and supercritical CO2 fractures, single factor variable control experiments were conducted with natural fracture angles of 30 °, 45 °, and 60 °, and in-situ stress deviations of 3, 5, 7, and 9 MPa. Our research delves into the impact of natural fracture inclination angle, in-situ stress deviation, and natural fracture size on supercritical CO2 fractures development. This comprehensive exploration unveils the intricate interaction mechanisms between natural fractures of different sizes and supercritical CO2 fractures. Various control chart were studied, considering different natural fracture under diverse ground stresses and inclinations. The findings of this study bear theoretical significance and engineering application for enhancing efficiency in shale gas production.

In this paper, thermal transfer with natural convection in a tilted annular cylinder with a Cu-water nanofluid has been numerically studied. The hot interior and cold exterior elliptical surfaces of the enclosure were maintained at constant temperatures Th and Tc , respectively. The governing equations were solved by the stream function-vorticity approach. The finite volume approach was utilized to discretise the controlling equations. The volume fraction range of the nanoparticles and the Rayleigh number was as follows: 0

Once fires occur unexpectedly at the oil-hydrogen integrated refueling stations, there is a high likelihood that they will escalate into a coupled fire, resulting in unpredictable casualties and property losses. In this work, experiments on coupled fire induced by hydrogen jet flame and a heptane pool flame were conducted with different nozzle diameters and release pressures. It has been found that there is a critical diameter above which the hydrogen jet can be ignited instantly. This critical diameter is determined by the release pressure and the location of the pool flame. The heat release rate is greater than that of the single pool flame, and it reaches its highest point at 0.2 MPa. Compared to a single fire, the height of the flame decreases while the length of the flame increases, a prediction model is proposed for the dimensionless flame length and width, taking into account the ratio of the heat release rate of the hydrogen jet flame to the heat release rate of the pool flame. The temperature of the coupled fire reaches its highest point at 0.2 MPa and increases as the nozzle diameter. And it decreases with the increase in the distance when Y= 0 m. However, it increases with the increase of the distance when Y= 0.05 m due to the inclination of the flame. [ABSTRACT FROM AUTHOR]

At present, Global Navigation Satellite System (GNSS) satellites operate in medium Earth orbits (MEOs), geostationary orbits (GEOs), or inclined geosynchronous orbits (IGSOs). The QZSS consists of GEO and IGSO satellites. When we considering the QZSS skyplot in Japan and its surrounding areas, there are no satellites in the northern sky. This results in a geometric placement imbalance, and thereby, causes position errors. The fundamental method to solve this problem is to position a satellite in the vacant northern area. Therefore, in this research, the addition of navigation satellites with a highinclination, high-eccentricity orbit (a new type of orbit) is proposed. The vacant northern area can be filled effectively by adding a satellite using this orbit. Three satellites with this orbit were added to the QZSS in a simulation. Thereby, satellites were positioned effectively in the vacant northern area of the skyplot for Tokyo and Seoul. In addition, the improvement in performance was verified quantitatively through Horizontal Dilution of Precision (HDOP) and Vertical Dilution of Precision (VDOP). Accordingly, the addition of a satellite with a high-inclination, high-eccentricity orbit to the QZSS would enable more accurate positioning in Japan and its surrounding areas. [ABSTRACT FROM AUTHOR]

Trimming the scrap portion of ultra-high strength steel (UHSS) components poses a significant challenge due to the inherent high strength and hardness characteristics of the material. For UHSS components with a higher geometric complexity such consisting of inclined and curved sections, sharp tilt, and small bend radius, the large trimming load results in poor sheared quality and shape defects, which commonly happen in these areas. This research investigated the effects of applying a small inclination angle to the punch in the trimming of the UHSS parts having an inclined and curved shape. The inclined punch was modified to four sets of different degrees of inclination i.e., 1°, 3°, 5°, and 10°. A comparative analysis of the trimming load, trimming energy, sheared edge quality and shape defects was conducted between these modified punches and the normal punch for their effectiveness in the trimming operation. Results showed that the application of inclination angle significantly decreased the trimming load, reduced the trimming energy, and improved the sheared edge surface quality, as well as prevented the shape defects at the inclined and curved zones as compared to the outcomes produced when trimming using the normal punch. The study suggested that the change to the punch geometry is an effective option to improve the performance of the process as well as the quality of the part, particularly in trimming the high-strength components having complex shapes. [ABSTRACT FROM AUTHOR]

This study is aimed at comprehensively analyzing and estimating the effects in gas dynamics, as well as mechanical and optical effects, from the Kyiv meteoroid that entered the terrestrial atmosphere and exploded over Bila Tserkva raion, Kyiv oblast (Ukraine). According to the International Meteor Organization (IMO), the apparent magnitude of the meteoroid was –18. According to our estimates, the luminous power was 215 GW with an effective duration of 2.4 ± 0.2 s, the total luminous energy was 25.2 ± 2.5 GJ, and the initial kinetic energy was 0.09 ± 0.01 kt of TNT or 375 ± 35 GJ. The initial mass of the cosmic body was estimated to be 0.89 ± 0.09 t, the volume was 0.250 ± 0.025 m3, and the size was 79 ± 3 cm. The initial velocity of the meteoroid reached 29 km/s. The inclination angle, i.e., the angle that the trajectory makes with the horizontal plane, was 32°. The explosion altitude equal to 38 km and the inclination angle equal to 32° give an estimate of 3.5 t/m3 for the material density, which is close to the rock density. The energy of the processes, the gas dynamics effects, and the mechanical and optical effects from the celestial body have been analyzed. The main release of energy associated with the deceleration of the fragments of the celestial body, which was defragmented under a dynamical pressure of approximately 2.5 MPa, took place in the region with a length of 2 km at an altitude of approximately 38 km. A quasi-continuous defragmentation is suggested to produce a mass distribution that follows a power law. The main parameters of the ballistic and explosive shock waves have been estimated. For the Mach number of 97, the radius of the ballistic shock wave is estimated to be approximately 77 m, and the fundamental period to be 0.7 s, which showed a dispersive increase from 3.7 to 11.5 s with the propagation path length increasing from 50 to 5000 km. The radii of cylindrical and spherical wavefront shock waves were approximately 0.28 and 0.34 km, and their fundamental periods were approximately 2.6 and 3.2 s, respectively. These periods increased from 9.5 to 30.0 s and from 11.1 to 35.1 s with an increase in the propagation path length from 50 to 5000 km. In the vicinity of the meteoroid's explosion height, the relative excess pressure was a maximum. It decreased with a decrease in the altitude and increased with an increase in the altitude up to approximately 120–150 km, at which it attained values of approximately 6–7% and then further decreased down to a few percent. The absolute value of the excess pressure is estimated to be near the altitude of the explosion; subsequently it decreased with a decrease in the altitude down to 20–25 km and then increased further again. At the epicenter of the explosion, it is estimated to be approximately 94 Pa for the cylindrical wavefront and approximately 99 Pa for the spherical wavefront, which is not enough to damage objects on the ground. The excess pressure decreased with an increase in the altitude from 8–15 Pa to a few micropascals. Given an estimate of 2.4 s for the average duration of the effective light flash, the maximum power of the fireball is estimated to be 21 GW, and the power flux near the fireball (or more precisely, the cone 0.5 km in length and 2.4 m in diameter), is estimated to be 5.1 MW/m2. At the same time, the temperature is estimated to be approximately 3100 K, and the Wien wavelength is estimated to be 9.4 × 10–7 m. [ABSTRACT FROM AUTHOR]

The machining quality of the functional edges of inner ring groove have great influence on the performance of electro-hydraulic servo valve. The inclination angle of the functional edge is one of the most important indicators to evaluate the processing quality of functional edges. Therefore, a pneumatic measuring method based on pneumatic measuring theory for measuring the inclination angle of the edge of inner ring groove is proposed. The principle of measuring method and calculation method are analyzed. The measuring system parameters such as air source pressure, inlet nozzle diameter and slit width, which influence the measurement results are compared and analyzed, respectively. The results showed that those three measurement parameters significantly affect the slope of the measuring pressure curve. When the air source pressure, the inlet nozzle diameter and slit width are chosen as 90 kPa, 0.3 mm and 3 mm, respectively, the measurement system can be kept in a "subsonic-subsonic" state and good curve slope can be obtained. Based on the analysis, the measuring air path and other mechanical structure are designed. The experimental results indicate that the inclination angle relative to the central axis is 0.0387°. The proposed pneumatic measuring method can effectively measure the inclination angle of edge of the inner ring groove, which provides a method for evaluating the performance of the valve sleeve. [ABSTRACT FROM AUTHOR]

Experiments were conducted to investigate the dynamics of an oscillating bubble generated by a spark in the presence of an inclined attached air bubble. The study primarily focused on the influence of the inclination angle on the behavior of bubble jetting orientation, air bubble shape modes, and motion characteristics of the interaction between the two bubbles. Various complex bubble jetting behaviors were observed, including the presence of multiple types of bubble jetting directions, bubble splitting, and multidirectional jets. Four types of air bubble shapes were defined, namely inclined cup cover-shaped (with and without splitting), double-peaked cup cover-shaped, and inclined L-shaped air bubbles. The formation of different types of bubble jets was analyzed using the vector synthesis principle of the Bjerknes force exerted by the inclined attached air bubble and a steel plate. To describe the diverse orientations of bubble jetting and air bubble shapes, new parameters namely the dimensionless spark bubble oscillation time T* and volume ratio V* that consider the inclination angle are proposed. The findings of this investigation contribute to the existing knowledge and have the potential to further enhance methods for mitigating cavitation damage in marine, hydraulic machinery systems, and medical fields.l fields. [ABSTRACT FROM AUTHOR]

This work studies the inclination angle effect on the two-phase closed thermosyphon (TPCT) with semicylindrical condenser internal fins. The finned thermosyphon thermal performance is studied at two different inclination angles 30o and 60o. Water is the working fluid for different filling ratios (FR) of 20, 50 and 80. The experiments are performed at different input power levels. The thermosyphon temperature is measured and both the heat transfer convection and condensation coefficients are calculated. In addition, the overall heat transfer coefficient is calculated and used as an indication of TPCT thermal performance. The lowest thermal resistance occurred at 50% FR at an inclination angle of 30o. The results showed that, at 60o inclination angle the average temperature of the thermosyphon is slightly lower than the 30o. The thermal performance of the TPCT is superior at 80% FR for 600 inclination angle as it achieves the highest overall heat transfer coefficient at this condition. Based on the overall heat transfer coefficient values, The thermal performance of inclined TPCT is higher at inclination angle 60° compared to 30o inclination angle. [ABSTRACT FROM AUTHOR]

Abstract The heat transfer characteristics of S - C O 2 are investigated at different inclination angles ( α = 15°, 30°, 45°, 60°, and 90°) and pressures (p = 8, 9, and 10 MPa ). It is found that the SST   k − ω model can more accurately predict the heat transfer of S - C O 2 in horizontal tubes. When q w / G is large, the top surface temperature will rise sharply. It is due to the gas-like film weakens the thermal absorption efficiency and impedes the fluid in the core region from taking up thermal in the near-wall area, resulting in severe heat transfer deterioration. The buoyancy criterion G r q * / G r qth shows that the buoyancy and the gas-like film thickness decrease as the inclination angle increases, which effectively improves the heat transfer performance in the top area and weakens the heat transfer deterioration phenomenon. Affected by the critical temperature and the peak of specific heat, the bulk temperature also increases when the pressure increases. In the region of θ  = 45° to 315°, raising the pressure is accompanied by higher circumferential wall temperature, whereas in contrast to the change in N u w . [ABSTRACT FROM AUTHOR]

Abstract The study of the heat exchangers in the trapezoidal channels and the rectangular channels were carried out. The trapezoidal channel has smaller friction resistance than the rectangular channel with equal section, and the friction factor (f) decreases gradually with the increase of inclination angle, when β= 25 °, the f is the smallest, which is reduced by nearly 22.6% compared to the rectangular channel with equal cross-section; when , the heat transfer factor (j) and comprehensive heat transfer performance of the trapezoidal channel are greater than those of the rectangular channel with the same section, and when , those increase by 8% and 20%, respectively. The height and length of fins have a significant impact on heat transfer performance, increased by 17.65% and 20.85% respectively; By analyzing the comprehensive performance of the trapezoidal channel, the # 8 structure (Fh=10.5mm, β=5°, Sf=3mm, Lf=45mm, tf=0.3mm) has the optimal performance. [ABSTRACT FROM AUTHOR]

Discontinuous rock mass, such as joints and fractures, have a great influence on the blasting quality and sometimes induce additional damage at the discontinuity. In deep rock engineering, high in situ stress makes the damage mechanism of rock with discontinuity under blasting loading more complicated. Quantitative analysis of blast-induced damage in discontinuous rock under high in situ stress is of great importance in guiding the fine blast design. In this paper, a series of numerical models have been established to quantitatively investigate the effect of confining stress and inclination angle on blast-induced damage of rock with discontinuity. The numerical results show that the discontinuity obviously changes the distribution mode of blast-induced damage, and there is more damage near the discontinuity. The blast-induced damage crack length of discontinuous rock decreases as hydrostatic stress rises. Under non-hydrostatic stress, the damage crack propagation appears to have a higher tendency in the higher confining stress direction. In addition, the inclination angle of discontinuity will affect the damage distribution of rock with discontinuity. The fragmentation degree is greatest when the discontinuity is perpendicular to the direction of higher confining stress. Due to the presence of discontinuity, the guiding effect of higher confining stress on damaged cracks is weakened. The results provide a reference for the tunnel fine-blasting design of rock with discontinuity. [ABSTRACT FROM AUTHOR]

This paper focuses on the result of inclined angle on bioconvection of porous media bounded by cavity wall square enclosure filled with both nanofluid and gyrotactic microorganisms passing through the media with pores. The dimensionless velocity, temperature, concentration, and mass transformation equations are solved by using the weighted residual Galerkin’s finite element method. The result of the inclination angle from δ = 0◦ to δ = 180◦ in a square cavity is interpreted. The outcomes of incli-nation on various key parameters, such as Rayleigh number, bioconvective Rayleigh number, Peclet number, Brownian motion, and the ratio of buoy-ancy, are discussed. Furthermore, the mean Nusselt number, Sherwood number, and density number are discussed at vertical walls.

In the present study, multiscale finite element (FE) models of half-through steel basket-handle arch bridges were established. The eigenvalue analyses were conducted to explore the dynamic characteristics of the arch bridges based on the FE models. In addition, a parametric analysis was carried out to investigate the impact of the inclination angle of the arch rib (0°, 4°, and 7°) on the longitudinal and transverse seismic performances of arch bridges. The results show that with the increase in inclination angle, the out-of-plane stiffness of half-through steel basket-handle arch bridges increases, resulting in the natural period of the structure becoming shorter from 3.09 s to 2.93 s. Adjusting the inclination angle appropriately has a beneficial impact on the overall seismic performance of the structures, affecting both displacement and internal forces, in which the most significant improvements include a 42.8% decrease in displacement and a 62.6% reduction in internal forces. Adjusting the inclination angle can cause the arch springing and transverse brace to undergo larger plastic deformation. It is advisable to judiciously enlarge the sectional dimensions and enhance the material strength of both the arch springing and the transverse bracing in seismic designs.