Variation Of Fraction Research Articles

Analysis of heat transfer coefficient in radiator cooling system using TiO2/CuO hybrid fluid

The automotive industry is growing, encouraging more efficient car cooling systems, especially radiators. Innovations are constantly being made to improve the performance of radiators. Choosing the correct fluid is one of the ways to increase heat transfer. This study aimed to compare the performance of coolant OBC and TiO2/CuO hybrid fluid mixed with coolant OBC to investigate the increase in heat transfer in the car's radiator. The first step is to make TiO2/CuO hybrid fluid with a two-step method, with volume fraction variations of 1.0, 2.0, 3.0, 4.0, and 5.0%, and observe stability for 30 days. Viscosity and thermal conductivity tests are used to assess the thermophysical properties of the sample. Hybrid fluid samples of TiO2 / CuO with a volume fraction of 5.0% showed the best stability and thermal conductivity, then were added to the coolant brand OBC (1:4). The results showed an increase in heat transfer rate of 23% and a heat transfer coefficient of 20% in the TiO2/CuO hybrid fluid added to the coolant OBC

Twins in diversity: understanding circumstellar disc evolution in the twin clusters of W5 complex

ABSTRACT Young star-forming regions in massive environments are ideal test beds to study the influence of surroundings on the evolution of discs around low-mass stars. We explore two distant young clusters, IC 1848-East and West located in the massive W5 complex. These clusters are unique due to their similar (distance, age and extinction) yet distinct (stellar density and far-ultraviolet radiation fields) physical properties. We use deep multiband photometry in optical, near-infrared and mid-infrared wavelengths complete down to the substellar limit in at least five bands. We trace the spectral energy distribution of the sources to identify the young pre-main sequence members in the region and derive their physical parameters. The disc fraction for the East and West clusters down to 0.1 M$_\odot$ was found to be $\sim 27\,\pm$ 2 per cent (N$_\mathrm{disc}$ = 184, N$_\mathrm{discless}$ = 492) and $\sim 17\,\pm$ 1 per cent (N$_\mathrm{disc}$ = 173, N$_\mathrm{discless}$ = 814), respectively. While no spatial variation in the disc fraction is observed, these values are lower than those in other nearby young clusters. Investigating the cause of this decrease, we find a correlation with the intense feedback from massive stars throughout the cluster area. We also identified the disc sources undergoing accretion and observed the mass accretion rates to exhibit a positive linear relationship with the stellar host mass and an inverse relationship with stellar age. Our findings suggest that the environment significantly influences the dissipation of discs in both clusters. These distant clusters, characterized by their unique attributes, can serve as templates for future studies in outer galaxy regions, offering insights into the influence of feedback mechanisms on star and planetary formation.

Distribution of Salts in Milk and Cheese: Critical Methodological Aspects

The salt fractions of milk consist of cations (e.g., Ca, Mg, and Na) and anions (e.g., phosphate, citrate, and chloride). These salts are present as free ions or in complexes with other ions or proteins, primarily the caseins. Furthermore, significant levels of Ca and phosphate are also found in insoluble form, inside the casein micelles. The distribution of salts between this micellar phase and the soluble phase is important for the stability and properties of milk and dairy products. Various processes, such as (ultra-)centrifugation, (ultra-)filtration, dialysis, and selective precipitation have been used to separate the micellar and soluble phases in milk and dairy products to allow for studying the salts’ distribution between these phases. These different methods can lead to different levels of soluble salts because the salts in the supernatant from centrifugation, the permeate from ultrafiltration, and the diffusate from dialysis can differ notably. Hence, understanding which components are fractionated with these techniques and how this affects the levels of the soluble salts determined is critical for milk and dairy products. Applying the aforementioned methods to cheese products is further challenging because these methods are primarily developed for fractionating the soluble and micellar phases of milk. Instead, methods that analyze salts in water-soluble extracts, or soluble phases expressed from cheese by pressing or centrifugation are typically used. This review focuses on the significance of salt distribution and variations in salt fractions obtained using different methodologies for both milk and cheese.

Probing the Dust Grain Alignment Mechanisms in Spiral Galaxies with M51 as the Case Study

Magnetic fields (B fields) in galaxies have recently been traced using far-infrared and submillimeter polarimetric observations with the Stratospheric Observatory for Infrared Astronomy, James Clerk Maxwell Telescope, and Atacama Large Millimeter/submillimeter Array. The main assumption is that dust grains are magnetically aligned with the local B-field in the interstellar medium (ISM). However, the range of physical conditions of the ISM, dust grain sizes, and B-field strengths in galaxies where this assumption is valid has not been characterized yet. Here, we use the well-studied spiral galaxy M51 as a case study. We find that the timescale for the alignment mechanism arising from magnetically aligned dust grains (B-RAT) dominates over other alignment mechanisms, including radiative precession (k-RAT) and mechanical alignment (v-MAT), as well as the randomization effect (gas damping). We estimate the sizes of the aligned dust grain to be in the range of 0.009–0.182 μm and 0.019–0.452 μm for arms and interarms, respectively. We show that the difference in the polarization fraction between arms and interarms may arise from the enhancement of small dust grain sizes in the arms resulting from large grains being broken into small grains as an effect of the grain alignment disruption (RAT-D) mechanism. We argue that the RAT-D mechanism needs to have additional effects, e.g., intrinsic variations of the B-field structure and turbulence, in the galaxy’s components to fully explain the polarization fraction variations within the arms and interarms.

Risk factors of all-cause mortality in heart failure with mildly reduced ejection fraction patients with different post-discharge left ventricular ejection fraction variation patterns

Abstract Background The identification of risk factors for all-cause mortality in patients diagnosed with heart failure with mildly reduced ejection fraction (HFmrEF) and exhibiting varying post-discharge left ventricular ejection fraction (LVEF) patterns remains incomplete. This study aimed to determine the independent risk factors of all-cause mortality among HFmrEF patients with different LVEF variation patterns post-discharge. Methods This retrospective study analyzed data from 807 HFmrEF patients admitted to our hospital between January 2015 and August 2020. Patients were categorized into three groups based on LVEF variation patterns within 6 months to one year post-discharge: Group A (transitioning to heart failure with reduced ejection fraction [HFrEF], n=225), Group B (remaining as HFmrEF, n=335), and Group C (reverting to heart failure with preserved ejection fraction [HFpEF], n=227). Patients were followed up for a mean of 33 months, with all-cause mortality as the primary endpoint. Multivariate Cox regression analysis was conducted to identify independent risk factors for all-cause mortality in each group. Results The mortality rates for Groups A, B, and C were 43.11%, 23.94%, and 24.67%, respectively (P<0.001). Independent risk factors for all-cause mortality in Group A included age (HR=1.04, P=0.007), obesity (HR=1.76, P=0.040), higher creatinine (>100 µmol/L, HR=1.83, P=0.029), higher E/e’ (HR=1.06, P=0.001), absence of PCI (HR=0.51, P=0.019), and non-use of ACEI/ARB (HR=0.039, P=0.006). In Group B, independent risk factors for all-cause mortality were age (HR=1.06, P<0.001), higher NT-proBNP (>2505 pg/ml, HR=2.50, P=0.002), and absence of PCI (HR=0.040, P=0.005). Group C exhibited age (HR=1.04, P=0.002), pleural effusion (HR=2.38, P=0.007), higher creatinine (>100 µmol/L, HR=2.84, P<0.001), and non-use of ACEI/ARB (HR=0.42, P=0.021) as significant independent risk factors associated with increased all-cause mortality risk. Conclusion This study highlights distinct risk factors associated with all-cause mortality in HFmrEF patients exhibiting different post-discharge LVEF variation patterns. Age emerged as a consistent risk factor across all groups, underscoring the importance of age-related considerations in managing HFmrEF patients. Additionally, factors such as obesity, renal function, echocardiographic parameters, and medication adherence played varying roles in influencing mortality risk depending on the evolution of LVEF following discharge. These findings emphasize the need for personalized risk stratification and tailored management strategies for HFmrEF patients to improve outcomes and reduce mortality rates.

Evaluating the impacts of area closure on soil properties in south central highland of Ethiopia

Soil degradation affects its quality and productivity of the land. To control soil degradation, various soil and water conservation (SWC) measures, including area closure are implemented. Understanding the impacts of SWC measures could support planning and implementation of land management practices. This study aimed to investigate impacts of area closure on soil properties in south central highland of Ethiopia. To acquire the necessary data, we conducted interviews with 80 households. Furthermore, nine years old area closure with physical soil and water conservation (AC-SWC), open grazing with physical SWC (OG-SWC), and open grazing without physical SWC (OG) were identified and each divided into upper, middle, and lower slope positions. In each slope position, 3 sample plots were established at 25–50 m intervals. A total of 27 composite samples and other 27 core samples for bulk density (3 treatments∗3 slope position∗3 replications) were collected and analyzed for soil properties. The data were analyzed using descriptive statistics and one-way ANOVA. The results showed that about 98 % of the respondents perceived that area closure would be an effective way to restore degraded land. Majority of the farmers (86 %) believed that area closure could reduce soil erosion and replenish soil fertility and thus, is beneficial in improving land productivity. Soil test results revealed that AC-SWC had significantly greater (P < 0.05) clay fractions, pH, available potassium, and available phosphorus than OG-SWC and OG. Variations of soil organic carbon (SOC) and total nitrogen (TN) were more pronounced. The SOC in AC-SWC was 83 % and 314 % greater than OG-SWC and OG, respectively. In the AC-SWC, TN was three and seven times higher than that of OG-SWC and OG, respectively. This could be due to vegetation restoration that reduces erosion, and enhances organic matter, moisture, and nutrient. The SOC, TN, pH, available potassium, and clay were significantly greater (P < 0.05) at lower slope position than upper in all forms of land management, which could be due to deposition at downslope. About 12 % and 11 % variations of clay fractions and SOC were, respectively, observed in between upper and lower slope positions at AC-SWC, but they varied by 25 % and 57 %, respectively, in OG. These imply area closure has had a beneficial effect on soil properties even on sloping land. AC-SWC is an important option to integrate in land management for rehabilitation of degraded soil.

Multi-scale modeling of aerosol transport in a mouth-to-truncated bronchial tree system

Computational fluid particle dynamics (CFPD) is widely employed to predict aerosol transport in a truncated bronchial tree model on account of its capacity to reveal details of flow field and particle movement. However, setting a physiologically consistent boundary condition in the CFPD for the idealized or image-based truncated bronchial tree model is still a challenge. This paper proposes a multi-scale modeling method, which contains an Extend-Bronchial tree-Network (EBN) boundary condition for a mouth-to-truncated bronchi system. The comparison between EBN boundary condition and a commonly used uniform pressure (UP) boundary condition is conducted. Subsequently, EBN method is used to study the nano-micron (100 nm–10 μm) particles transport in the mouth-to-truncated bronchi model at different inhalation volume rates (15, 60, 90 L/min). Results show that EBN method is more physiologically rational and two methods differ in flow distribution in lobes, vortex structure, and particle transport. The maximum difference in flow rate distribution in lobes between two methods is about 20 %, while the maximum relative disparity of particle penetration fraction from lobes and deposition fraction in the TLB is about 93 % and 30 %, respectively. Meanwhile, this paper reveals the variation of deposition fraction and penetration fraction with the changes in particle diameter and inhalation volume. Deposition efficiency, deposition hotspots and deposition mechanism are also analyzed with inlet Stokes number (Stk) and Reynolds number (Re). This research establishes a foundation for the simulation of aerosol transport in a whole respiratory tract and provides references for inhalation drug delivery and air pollutant management.

On the stability of coherent HfRu- and ZrRu-B2 precipitates in Nb-based alloys

High temperature creep strengths of Nb-based alloys have been limited by the lack of coherent precipitates that exist at temperatures above 1200▪. In this investigation, a series of BCC Nb-based alloys with coherent HfRu- and ZrRu-B2 precipitates were investigated to determine the dependence of phase stability, misfit, and solvus temperatures on composition. Sequential anneals from 1000-1500▪ were used to determine the B2 solvus temperature (Ts,B2) of each alloy and solvus lines were constructed for each system. HfRu-B2 is found to be more thermally stable than ZrRu, with HfRu-containing alloys demonstrating higher Ts,B2 at equivalent Ru concentrations. For alloys with Ts,B2 above 1200▪, additional anneals at 1000 and 1200▪ provide insight into B2 volume fraction variations with temperature. Additional Hf- and Zr-rich tertiary phases also formed on the grain boundaries of the selected compositions at intermediate to high temperatures. Through transmission electron microscopy, the lattice misfits for the B2 precipitates were found to be ≈ 0.5% at 1000▪ and the grain boundary phases were identified as C14 Laves, L10, β-Hf, and topologically close-packed P phases. Implications for the design of Nb-based alloys strengthened by Ru-B2 precipitates, including strategies to mitigate deleterious phase formation, are discussed throughout.

Optimization and analysis of Si/SiGe strained vertically stacked heterostructure on insulator FeFinFET for high performance analog and RF applications

As semiconductor technology advances, the exploration of novel materials and device architectures becomes imperative to meet the growing demands of integrated circuits for analog and radio-frequency (RF) applications. In this paper, various advanced technologies have been amalgamated such as integration of ferroelectric layer in multigate FinFET along with the adaptation of SOI technology. Further strain technology is also used which employs a tri-layered strained-silicon channel system with the help of SiGe to form Vertically Stacked Heterostructure on Insulator Ferroelectric based FinFET (VS-HOI-FeFinFET) and on comparison with baseline FeFinFET, it is found to show remarkable improvements in terms of various measured parameters such as drain current, switching ratio, threshold voltage and subthreshold swing. Subsequently, gate stacking architecture is incorporated in VS-HOI-FeFinFET to further optimize the device performance. The four different configurations C1 to C4 are taken in terms of four different combinations of gate stack materials considered for gate oxide such as C1(SiO2+Al2O3), C2(SiO2+HfO2), C3(Al2O3), and C4(Al2O3+HfO2). It is found that the static and analog performance of VS-HOI-GS-FeFinFET enhance sequentially from configuration C1 to C4 such as switching ratio is enhanced upto around 5 times, DIBL and quality factor are improved by around 41% and 58% respectively along with significant improvement in device efficiency, early voltage, intrinsic gain, output conductance and output resistance. Subsequently performance optimization of VS-HOI-GS-FeFinFET with variation in mole fraction of germanium is also explored for various analog metrics. Further, several RF parameters are also explored and it is observed that the gain frequency product (GFP) and gain transconductance frequency product (GTFP) are augmented by around three times in magnitude along with 16% reduction in the unity gain cut off frequency in C4 configuration, exhibiting its ability of high frequency amplification with minimized noise distortion thus makes the device suitable for various high performance Analog and RF applications.

Distinguish microphase-separated structures of diblock copolymers using local order parameters

The microphase-separated structures of block copolymers are inherently highly ordered local structures, commonly characterized by differences in domain width and curvature. By focusing on diblock copolymers, we propose local order parameters (LOPs) that accurately distinguish between adjacent microphase-separated structures on the phase diagram. We used the Molecular Assembly structure Learning package for Identifying Order parameters (MALIO) to evaluate the structure classification performance of 186 candidate LOPs. MALIO calculates the numerical values of all candidate LOPs for the input microphase-separated structures to create a dataset, and then performs supervised machine learning to select the best LOPs quickly and systematically. We evaluated the robustness of the selected LOPs in terms of classification accuracy against variations in miscibility and fraction of block. The minimum local area size required for LOPs to achieve their classification performances is closely related to the characteristic sizes of the microphase-separated structures. The proposed LOPs are potentially applicable over a large area on the phase diagram.

Inactivation induced by pathogenic Cav1.3 L-type Ca2+-channel variants enhances sensitivity for dihydropyridine Ca2+ channel blockers.

Pathogenic gain-of-function mutations in Cav1.3 L-type voltage-gated Ca2+-channels (CACNA1D) cause neurodevelopmental disorders with or without endocrine symptoms. We aimed to confirm a pathogenic gain-of function phenotype of CACNA1D de novo missense mutations A749T and L271H, and investigated the molecular mechanism causing their enhanced sensitivity for the Ca2+-channel blocker isradipine, a potential therapeutic for affected patients. Wildtype and mutant channels were expressed in tsA-201 cells and their gating analysed using whole-cell and single-channel patch-clamp recordings. The voltage-dependence of isradipine action was quantified using protocols inducing variable fractions of inactivated channels. The molecular basis for altered channel gating in the mutants was investigated using in silico modelling and molecular dynamics simulations. Both mutations were confirmed pathogenic due to characteristic shifts of voltage-dependent activation and inactivation towards negative potentials (~20 mV). At negative holding potentials both mutations showed significantly higher isradipine sensitivity compared to wildtype. The affinity for wildtype and mutant channels increased with channel inactivation as predicted by the modulated receptor hypothesis (30- to 40-fold). The IC50 was indistinguishable for wildtype and mutants when >50% of channels were inactivated. Mutations A749T and L271H induce pathogenic gating changes. Like wildtype, isradipine inhibition is strongly voltage-dependent. Our data explains their apparent higher drug sensitivity at a given negative voltage by the availability of more inactivated channels due to their more negative inactivation voltage range. Low nanomolar isradipine concentrations will only inhibit Cav1.3 channels in neurons during prolonged depolarized states without selectivity for mutant channels.

Optimization of heat transfer in PCM based triple tube heat exchanger using multitudinous fins and eccentric tube

This study aims to analyze the effect of incorporating a hybrid concept of heat transfer enhancement using extended surfaces and eccentricity of the inner tube in an RT-82 phase change material-based horizontal triple tube heat exchanger. Three types of fins were used, namely longitudinal, arc and triangular shape fins, as per suitability for better heat transfer. Moreover, the concept of eccentricity was also implemented to make PCM melt faster. The novelty of the present study lies in optimizing the heat transfer enhancement by proper placement of the fins and eccentric inner tube arrangement. A conduction-convection model was used to examine the thermal performance of a triple tube heat exchanger. The natural convection of PCM was employed using the Boussinesq approximation. The governing equations were solved using finite volume-based Ansys Fluent 2021 R2 software. The performance study of phase change material was based on transient variation of liquid fraction and average temperature. The optimum model showed a 63.87 % reduction in melting time and a 175.16 % improvement in heat transfer rate compared to a simple triple tube heat exchanger to achieve the unit liquid fraction. It is also observed from the calculation of the Rayleigh number that the conduction became more dominant than the convection phenomenon in the fin based model. The main finding of the present study is the use of triangular fins on the base along with the curved fins at the lower middle section because this arrangement shows high heat penetration capability. The results indicate that fins selection and placement significantly enhance the heat transfer rate.

Modeling pore fluid pressure and deformation in unsaturated soils under gravitational compaction and cyclic loading

Cyclic loading of fluid-bearing soils often induces excess pore water pressure, leading to accumulation of strain in the solid matrix. Additionally, variations in material density and volumetric fraction due to gravitational effects generate momentum forces, which subsequently cause deformation in the soil. In this paper, we present a mathematical framework of poroelasticity that generalizes the simultaneous action of gravitational body forces and cyclic loading to analyze solid deformation and fluid pressure dissipation in partially-saturated porous media. To account for the effect of gravity, the gradient of the vertical displacement needs to be treated as an additional dependent variable alongside pore air and water pressures.We numerically solve a mixed strain-controlled and pressure-prescribed boundary-value problem using a finite difference scheme as a representative example to quantify the impact of gravitational forces. Our results show that gravitational compaction affects both total settlement and excess pore water pressure, with its influence being particularly significant at lower water saturations, regardless of excitation frequency, soil depth, or type. The effect of gravity is more pronounced in soils with higher compressibility but appears insensitive to excitation frequency. Notably, the gravitational effect correlates linearly with the depth of the soil deposit and, therefore, should be well integrated into the consolidation theory of poroelasticity.

Investigation on heat transfer enhancement of PCM by tree-like fins

Abstract The limited thermal conductivity of PCM significantly hampers the potential applications of phase change heat storage. To enhance heat transfer efficiency, fins can be incorporated into the phase change unit. In this study, two tree-like fins were designed based on fractal principles, and a transient model for fin-lauric acid phase change was established. Through numerical simulations, we investigated and compared the variations in liquid fraction of units equipped with fractal fins, traditional rectangular fins, and without any fins. In order to explore the variation of the heat transfer process in the units, the solid-liquid interface and temperature distribution were analyzed. The results demonstrate that due to their superior enhancement effect on heat conduction outweighing any inhibitory effects from natural convection, fractal fins exhibit significant improvements in heat transfer performance by shortening the complete melting time by 33.72% and 29.17%, respectively, for each type of tree-like fin.

Strong large‐scale structure–function coupling in benthic bacteria is mediated by algae in a geodiverse river network

AbstractBenthic bacteria in stream ecosystems drive organic matter mineralization. However, knowledge on how this ecosystem function is driven by bacterial community composition in interaction with environmental conditions and organic matter resources is poor. This is especially true when considering the regional scale of river networks, at which environmental conditions vary in a scale‐dependent manner and are spatially structured due to asymmetrical water flow. Similarly, organic matter resources may have a terrestrial origin in remote headwaters or be sourced locally from algae living in close proximity to bacteria in benthic biofilms. We investigated benthic biofilm meta‐community structure and function across the &gt; 6700 km2 river network of the near‐natural Vjosa in Albania and Greece and found a strong control of the benthic algal community on bacterial community composition (13.4% of variability explained). In addition, bacterial community composition has linkages to water chemistry, which itself is strongly shaped by the diverse geology in the catchment, and to dispersal, shaping metacommunity structure as a neutral process. Notably, bacterial community composition explained the largest single fraction of variability (31.5%) in extracellular enzymatic activities, while there was no dependency of enzyme ratios on organic matter nor environmental conditions. Synergistic effects between bacteria and algae accounted for additional 47.3% of variability in heterotrophic functioning, emphasizing the importance of algal–bacterial interactions in benthic biofilms. Our findings shed new light on bacterial structure–function coupling highlighting the importance of algal–bacterial interactions at the river network scale.

Investigation of the insoluble impurities' impact on flow boiling heat transfer in aluminum microchannel heat exchangers

Microchannel flat-tube heat exchangers are known for their high heat transfer efficiency and compact size. In practical applications, the predominantly adverse influence of insoluble impurities on the condensation process necessitates further exploration into the underlying mechanisms affecting the flow boiling process. The effect of common insoluble impurities on the flow boiling of R410A refrigerant in a microchannel flat-tube heat exchanger has been investigated, and variation of the impurity volume fraction on heat transfer, mass transfer, pressure drop, and bubble formation are analyzed. Additionally, an adaptive modification method for the mass transfer factor is proposed. The numerical model of flow boiling heat transfer in a microchannel is validated through experimental data and empirical correlations. Thermo-hydraulic performance evaluation incorporates efficiency index and area goodness ratio metrics. Results reveal that the presence of insoluble impurities complicates the boiling heat transfer mechanism by influencing bubble evolution and multiphase flow patterns. Air impurities at a volume fraction not exceeding 5% prove beneficial for enhancing flow boiling efficiency in microchannels; however, a 38.5% decrease in efficiency index is observed with 1% oil impurities present. Optimal thermo-hydraulic performance is achieved with approximately 2%–3% water impurities.

Evaluating common supply air temperature setpoint reset strategies with varying occupancy patterns and behaviours

The supply air temperature (SAT) setpoint of a multi-zone variable air volume (VAV) air handling unit (AHU) systems significantly affects the system’s performance. ASHRAE Guideline 36 introduces a so-called trim and respond logic defining the SAT reset behaviour of these systems. The trim and respond logic for SAT reset relies on demand-based feedback. Many studies have assessed ASHRAE Guideline 36, however there is a literature gap in addressing the performance of the trim and respond SAT reset with varying occupancy patterns and behaviours. This paper studies four SAT reset strategies under different thermal preferences and irregular occupancy patterns: (1) constant 13°C SAT, (2) SAT reset based on outdoor air temperature (OAT), (3) trim and respond, and (4) trim and respond combined with OAT reset. Different cases of zone-level setpoints and irregular occupancy schedules have been simulated in EnergyPlus with the studied SAT setpoint reset methods. The results show that varying setpoints across different zones lead to higher energy use with all studied SAT reset strategies. The highest variation in energy use was accompanied with constant SAT, with a standard deviation of 16 kWh/m2, and the highest variation in averaged discomfort fraction was accompanied with OAT reset, with a standard deviation of 5.3%. Both trim and respond methods achieved better comfort results with varying setpoints. These findings establish a basis for future work on developing a SAT reset strategy that utilizes occupant-centric control (OCC) that optimally balances thermal comfort and energy use.

Diverse magmatism along the northern margin of Tarim during the Ediacaran: Transition from Rodinian dispersing to Gondwana assemblage

The Ediacaran igneous rocks and sedimentary sequences play a key role for our understanding the transition from dispersing of the Rodinian continents to the assemblage of the Gondwana. On the other hand, some continental massifs at the marginal area of the Rodinia and Gondwana could preserve solid evidences for deciphering the geodynamic background from the break-up of Rodinia to the assemblage of Gondwana. In this contribution, we report field observations, petrography, ages and systematic geochemistry of the diverse Ediacaran igneous activities in the northern margin of the Tarim Block, which was favored as a marginal continental massif in the Rodinia configuration by most geologists. The Ediacaran igneous rocks along the northern margin of Tarim include the Baicheng and Yangxia granites, Tiemenguan syenite, Kurle mafic dykes and the basalt layers in the Zamoketi Formation (northeastern Tarim) and the Sugetbrak Formation (northwestern Tarim). Precise zircon UPb dating revealed that these distinct rocks were broadly coeval with crystallization/eruption ages of 630–600 Ma. Bulk-rock elemental and SrNd isotope compositions as well as zircon LuHf isotope compositions demonstrate that the Baicheng and Yangxia granites were derived from Neoarchean mafic lower crust and underwent intensive fractionation before their emplacements. The Tiemenguan syenites have potassic andesitic compositions, in combination with their pronounced enriched NdHf isotopes and extremely high Zr saturation temperatures (∼900 °C), we argue that their possible shoshonitic primary magmas were derived from previously metasomatized subcontinental lithospheric mantle source (amphibole-bearing) and then, coupling with assimilation and fractional crystallization (AFC) effects in magma chamber and/or en route to the emplacement space. This can account for their intriguing geochemical features. The ca. 615 Ma Zamoketi and Sugetbrak basalts and the slightly younger porphyrite dykes (ca. 580 Ma) cutting the Zamoketi basalt layer, show typical OIB-like geochemical signatures, they were most likely derived from a depleted asthenospheric mantle source with variable fractionation of olivine and pyroxene and negligible crustal contamination before eruption. On the whole, the geochemistry of the diverse Ediacaran igneous rocks unambiguously demonstrates that they were genetically related to an extensional environment. In combination with the significant passive continental features of the Ediacaran-Cambrian sedimentary sequences, we consider that these Ediacaran igneous rocks were the latest phase of igneous activity related to the dispersing of the Tarim at the margin of the Rodinia supercontinent.The dispersing of the Rodinian supra-continent was diachronic with the assemblage of the Gondwana. Late Tonian to Ediacaran dispersing of the Tarim from northern margin of Australia induced the opening of the Proto-Tethys Ocean. Then the initiation of the southward subduction of the Proto-Tethys Ocean at ca. 530 Ma (Fortunian) led to the Tarim assemblage to Gondwana at ca. 440 Ma.

Sifat Mekanik Komposit Serat Pelepah Kelapa Sawit sebagai Penguat Komposit Terhadap Kekuatan Tarik dan Impak

Palm fronds are solid waste from oil palm plantations that contain a lot of natural fibers. One of the utilization efforts that can be done is to optimize palm frond fiber waste into composite materials. The use of natural fiber mixtures in composites has produced stronger materials, which can serve as alternative materials for car bumpers. This research was conducted with the aim of knowing the value of impact toughness, tensile strength, and the type of failure that occurs in the fracture cross section. In this study, composites were made using palm frond fibers and polyester resin. The volume fraction variation applied is 30% fiber and 70% matrix with fiber lengths of 20 mm, 40 mm, and 60 mm. Impact toughness testing refers to ASTM E23 standard and tensile strength testing refers to ASTM D638 standard. The impact toughness value obtained in the 20 mm variation was 0.0065 J/mm², 40 mm was 0.0108 J/mm², and the 60 mm variation had the highest value of 0.0164 J/mm². The tensile strength value obtained in the 20 mm variation is 6.18 MPa, the 40 mm variation is 8.26 MPa, and the 60 mm variation has the highest value of 16.45 MPa. Analysis of the fracture cross section is categorized as a splitting fracture in multiple areas and the fracture cross section also shows the occurrence of fiber pull out after the fracture.

Performance analysis of a novel gas-liquid separator with industrial application

This paper presents a novel gas-liquid separator characterized by its distinctive geometric design, capable of handling different volume fractions and mass flow rates. The separator's performance is comprehensively assessed across various gas volume fractions, bubble sizes, and mass flow rate fluctuations. The study reveals that variations in vapor volume fraction substantially affect both separation efficiency and pressure loss. An increase in vapor volume fraction from 0.1 to 0.5 leads to a 25% reduction in separation efficiency and a 3.3-fold decrease in pressure loss. In contrast, changes in mass flow rate exert a relatively minor influence on separation efficiency. Specifically, increasing the mass flow rate from 15 to 30 kg/s results in a mere 4% decrease in separation efficiency, whereas pressure loss increases by a factor of 3.2.Additionally, a reduction in bubble size from 1000 µm to 200 µm causes a 33% increase in pressure loss and a 14% decrease in separation efficiency. The incorporation of a meshpad in this design promotes the formation of a forced vortex, thereby enhancing the separation process.