Unit Volume Research Articles

A COMPARATIVE STUDY OF QUADRUPOLE RAIL LAUNCHER AND TWO-WING ARMATURE ELECTROMAGNETIC LAUNCHER: MAGNETIC AND PERFORMANCE METRICS

This study presents a novel two-wing armature electromagnetic launcher design that aims to overcome the limitations of conventional quadrupole railguns. The proposed TWAEL system exhibits significantly enhanced magnetic field properties, achieving a 23-fold increase in magnetic flux density, an increase in magnetic field intensity, and a 1.6-fold increase in current density compared to the QRL under identical input conditions. Consequently, the TWAEL demonstrates a 6.7-fold greater electromagnetic co-energy storage capacity per unit volume, translating to substantially higher accelerative forces, reaching up to 18,045 N. Simulations validate the TWAEL's superior performance in terms of magnetic field characteristics and energy conversion efficiency, highlighting its potential as an advanced, high-performance electromagnetic propulsion system for various applications.

Enhancing Sustainable Road Construction: Evaluation of the Mechanical and Durability Properties of Stabilized Earth-Based Pavement Materials

The materials traditionally used in the construction of flexible and rigid pavements in modern road infrastructure present challenges in achieving sustainable development goals. Advances in technology have introduced the use of different pavement material mixes, leading to the introduction of earth-based alternatives. These materials are environmentally friendly, cost-effective, recyclable, and offer excellent insulation properties. Stabilization of earth-based materials improves their mechanical properties, reducing road construction costs and increasing durability. The present study investigates the mechanical and durability properties of earth-based materials stabilized with various additives, including cement, lime, polymer, and biopolymer, over 28 and 56 days. Fresh properties are assessed using unit volume weight, flow table, air content, and fall cone tests, while hardened properties are assessed using flexural strength, compressive strength, and water absorption. Microstructural analysis is carried out using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The cement-stabilized samples show improved strength and durability, with the 5% cement group showing a 67% increase in compressive strength over the control group and the 10% cement group showing over 200% higher compressive strength. These results suggest that stabilized earth-based materials could provide a cost-effective and sustainable alternative to conventional pavements for low-traffic roads.

Scaling relationships of lamina mass per unit area, mean thickness, and leaf bulk tissue density across nine diverse species.

Although previous studies have reported a positive correlation between leaf dry mass per unit area (LMA) and mean leaf thickness (LT), the LMA versus LT scaling relationship has not been determined due to limited sample sizes, despite its importance in estimating leaf bulk tissue density (mass per unit volume). This issue was addressed using between 174 and 185 leaves from each of nine phylogenetically diverse species to investigate the LMA vs. LT scaling relationship. For each leaf, lamina thickness was measured at 12 positions (avoiding midribs and major veins) to calculate LT, and LMA was measured based on leaf area and dry mass measurements. Reduced major axis regression protocols were used to determine the LMA vs. LT scaling exponent (i.e., the slope). Bootstrap percentile methods were used to calculate the 95% confidence intervals of slopes. A statistically significant LMA vs. LT relationship was found for each species; seven of the nine scaling exponents were significantly greater than unity indicating that LMA (and thus leaf bulk tissue density) disproportionately increased with increasing LT. In addition, the conspecific variation in LMA exceeded the interspecific variation in LMA as a consequence of differences in LT. These results indicate that empirical measurements of LMA and LT can be used to accurately estimate leaf bulk tissue density, which provides insights into adaptive life-history strategies, conspecific variation, and (with sufficiently large data sets) phylogenetic trends.

Spatial magnetic force and magnetic energy density analysis of microsphere medium in high gradient magnetic fields: a 3D simulation

Abstract High gradient magnetic separation technology is the key technology for green and efficient separation and purification of mineral resources. Existing studies are vague about the division of the attraction and repulsion zones of the medium, and there are fewer explorations of the effect of various conditions on the attraction zones. In this work, a novel method for calculating the magnetic force is derived, which provides an accurate calculation of the 3D magnetic force. The attraction and repulsion zones are divided clearly by analyzing the relationship between the spatial angle of the spherical medium and the magnetic force density per unit volume, with the magnetic force density per unit volume tangent to the spherical surface as the dividing line. The attraction and repulsion zones are divided by β = 30°~35°, and the attraction region accounts for 45%~50% of the total space volume. Furthermore, the influence of different conditions on the attraction zone is studied. It was found that the zone of attraction decreases as one moves away from the spherical medium, which results in an ellipsoid with the effective zone of attraction of the spherical medium having the magnetic field direction as its long axis. The attraction region increases from 45.49% to 49.87% of the space occupied with increasing the relative permeability of the spherical medium. It does not affect the proportion of the attraction zone in space by changing the background magnetic field and the size of the spherical medium, but it will change the depth of the magnetic force. It provides a theoretical basis for the design of high-efficiency magnetic media, and gives a reference for further improving the selection effect of high gradient magnetic separation technology on fine and weak magnetic particles.

Estimation of missing third-law standard entropy of apatite supergroup minerals using the optimized Volume-based Thermodynamics

The thermodynamic characterization of apatite minerals, critical for understanding geological processes and material applications, faces significant challenges due to the scarcity of experimental data, particularly standard entropy (S°) values. In this study, we address this gap by optimization of predictive method based on Volume-based Thermodynamics. In the proposed method, the optimization of the widely used Volume-based Thermodynamics is based on breaking down a single linear functional relationship of formula unit volume (Vm) with S° into a set of linear equations. The apatite supergroup splits into distinct subgroups (populations) formed by Me10(AO4)6X2 with the same Me2+ cations and tetrahedral AO43− anions but with different anions at the X position. Our approach leverages empirical correlations between Vm and S° within specific apatite subgroups. By analyzing the correlations within the subgroups, we established the system of precise linear relationships between S° and Vm, facilitating accurate S° predictions for a wide range of apatite compositions. The proposed approach represents a significant advancement over existing predictive methods offering unparalleled accuracy in estimating S° values for apatite minerals. Through rigorous regression analysis and validation against experimental data, we demonstrate the reliability and robustness of our predictive model across various apatite subgroups. Our findings provide crucial thermodynamic data for understudied apatite compositions and shed light on fundamental relationships between crystal structure and thermodynamic properties in apatite minerals. The precise estimation of S° values enables more accurate modeling of phase equilibria, reaction kinetics, and geological processes involving apatite minerals, facilitating advancements in diverse fields ranging from environmental geochemistry to material science.

Larval development of two syntopic amphibian species (Bombina orientalis, Anura, Bombinatoridae and Dryophytes japonicus, Anura, Hylidae) living separately or jointly in the Far East, based on the results of laboratory studies

Competition is known to render significant impacts both on population dynamics and community structure. As it has traditionally been believed, Dryophytes japonicus larvae inhibit Bombina orientalis larvae when cohabiting. The study is devoted to the study of the influence of these species on the development of each other in experimental conditions. The larvae were grown before metamorphosis in three variants: with single maintenance, together with conspecifics at different densities, as well as with the joint maintenance of individuals of the two species. When kept alone, B. orientalis larvae, in comparison with D. japonicus, are characterized by a higher survival rate (100% vs. 85%), a shorter duration of larval development and a longer body length of individuals during the period of metamorphosis. With an increase in the duration of larval development, the size of D. japonicus juveniles is increased. There are no differences in survival rate when growing larvae of each species at different densities. The duration of larval development varied significantly in different experimental groups. In both species, the duration of development correlated with the initial density per unit volume of water and per unit area of the bottom. With increasing density, the length and mass of the larvae are decreased. The bottom area renders a greater impact on the duration of larval development, as well as the length and body weight of B. orientalis juveniles than the volume of water. According to the results of regression analysis, with an increase in the initial planting density of B. orientalis by 100 specimens per square mof the bottom, the duration of larval development was increased by 4.7 days, the body length decreased by 0.83 mm, and the weight dropped by 0.06 g. The volume of water has a greater influence on the same indicators of larval development of D. japonicus. With an increase in the initial density by 1 specimen per water liter, the duration of larval development of D. japonicus was increased by 11.7 days, the body length decreased by 0.37 mm, and the weight dropped by 0.07 g. When the larvae of the two species were grown together with an increased proportion of one of them, a negative impact was observed neither on the survival nor the development, nor the growth of the other species. On the contrary, with an increased number of conspecifics in the container due to a decrease in the number of individuals of the other species, the development and growth of larvae of the former species was inhibited. Thus, in the laboratory conditions, no noticeable interspecific competition was observed between the larvae of B. orientalis and D. japonicus. The authors suggest that a successful coexistence of these two species is associated with pronounced intraspecific competition in each of them, this previously noted for other animal taxa.

Performance analysis and engineering application of waste rubber crumbs in concrete

Abstract This study experimentally analyzed the impact of rubber particle content and KH-570 pretreatment on the workability and mechanical properties of rubberized concrete, as well as their environmental and economic benefits. The results indicated that the addition of rubber reduced workability, but this was mitigated by KH-570 pretreatment. At a 15% rubber content, pretreated rubberized concrete maintained peak stress similar to the control group, but beyond this threshold, peak stress dropped significantly. Compared to the control, RC25 exhibited a 6.9% increase in peak strain, while KRC25 only showed a 4.3% increase; the secant modulus of RC25 decreased by 46.8%, and that of KRC25 by 34.9%. In terms of toughness, the toughness index of RC25 increased by 15.4%, and KRC25 by 8.3%, demonstrating that rubber enhances concrete toughness, albeit with pretreatment affecting the deformability of rubber particles. KH-570 pretreatment significantly reduced the drying shrinkage of concrete, with a 22.7% reduction after 60 days. Rubberized concrete significantly lowered the CO2 emissions per unit volume, with RC25 reducing CO2E by 61.0% compared to the control group, highlighting the effectiveness of rubberized concrete in reducing carbon emissions associated with concrete production.

Investigation of the Arrangement of Aluminum Fins on the Thermal Behavior of Lauric Acid as a Phase Change Material in a Two-pipe Heat Exchanger by CFD Simulation

BackgroundPhase change material (PCM) thermal storage systems store more thermal energy per unit volume than sensible heat storage systems. PCMs offer a potential solution to reduce energy consumption in various thermal engineering applications. This study aimed to examine how fin arrangement affected the thermal efficiency and melting time of PCMs. MethodsA two-dimensional numerical analysis of the melting process of lauric acid in a heat exchanger featuring two pipelines and fins was conducted using CFD simulation. In most previous investigations, the heat transfer fluid was a single-phase liquid. An enthalpy-porosity technique was used to model the solid and liquid phases of PCM. The governing equations were solved using the commercial software ANSYS Fluent 2021, and the pressure and velocity equations were coupled using the SIMPLE algorithm. Significant FindingsThe best model among the 13 tested was Model 5, which featured 6 fins and a consistent angle of 60 degrees. For Model 5, the melting time was 1818.3 seconds. Due to sensible heating, the fin's temperature (Temp) rose gradually from 300 K to 318 K. Temp then gradually increased as the PCM melted in the phase transition zone between 316.5 K and 321.2 K. Once the phase transition was complete, the PCM's Temp steadily rose from 324 K to 340 K. In Model 5, the inner wall Temp and the maximum Temp of the PCM were closest, at 327.34 K and 333.55 K, respectively. The thermal shock between the PCM and the ambient Temp caused a peak heat flux at the beginning of the PCM loading process.

Recent developments in microfluidic passive separation to enable purification of platelets for transfusion

Platelet transfusion is a lifesaving therapy intended to prevent and treat bleeding. However, in addition to platelets, a typical unit also contains a large volume of supernatant that accumulates multiple pro-inflammatory contaminants, including residual leukocytes, microaggregates, microparticles, antibodies, and cytokines. Infusion of this supernatant is responsible for virtually all adverse reactions to platelet transfusions. Conventional methods for removing residual leukocytes (leukoreduction) and reducing the volume of transfused supernatant (volume reduction) struggle to mitigate these risks holistically. Leukoreduction filters can remove leukocytes and microaggregates but fail to reduce supernatant volume, whereas centrifugation can reduce volume, but it is ineffective against larger contaminants and damages platelets. Additionally, platelet purification based on these methods is often too logistically complex, time-consuming, and labor-intensive to implement routinely. Emerging microfluidic technologies offer promising alternatives through passive separation mechanisms that enable cell separation with minimal damage and drastically reduced instrumentation size and facility requirements. This review examines recent innovations in microfluidic cell separation that can be used for leukoreduction and volume reduction of platelets. It begins by defining the performance requirements that any separation method must meet to successfully replace conventional methods currently used to perform these tasks. Standard performance metrics are described, including leukocyte depletion efficiency, degree of volume reduction, processing throughput, and platelet recovery. Finally, the review outlines the primary challenges that must be overcome to enable simple-to-use, disposable microfluidic devices capable of both reducing the platelet unit volume and removing pro-inflammatory contaminants, while preserving most functional platelets for transfusion.

Role of microRNA in Diabetic Osteoporosis.

Diabetic osteoporosis (DOP), a complication associated with diabetes mellitus (DM), is a metabolic bone disorder characterized by a reduction in bone mass per unit volume, impaired bone tissue microarchitecture, heightened bone fragility, and increased susceptibility to fractures. Individuals with diabetes exhibit a significantly greater incidence of osteoporosis and related fractures than those without diabetes. These fractures present a significant challenge in terms of the healing process and can result in severe consequences, including fatalities. MicroRNAs (miRNAs), a class of noncoding RNAs, play a pivotal role in numerous human diseases and are implicated in the pathogenesis of DOP. This review initially elucidates the essential role of miRNAs in the pathogenesis of DOP. Next, we emphasize the potential significance of miRNAs as valuable biomarkers for diagnosing DOP and predicting DOP-related fractures. Furthermore, we explore the involvement of miRNAs in managing DOP through various pathways, including conventional pharmaceutical interventions and exercise therapy. Importantly, miRNAs exhibit potential as targeted therapeutic agents for effectively treating DOP. Finally, we highlight the use of novel materials and exosomes for miRNA delivery, which has significant advantages in the treatment of DOP and overcomes the limitations associated with miRNA delivery.

Comparative Analysis of the French-Russian Dictionary by N.P. Makarov (1910), the New French-Russian Dictionary by V.G. Gak, K.N. Ganshina (2006) and the Electronic Dictionary "Multitran"

The article is devoted to a comparison of paper and electronic French-Russian dictionaries. The material for the study was dictionary entries starting with the letter p from the French-Russian dictionary by N.P. Makarov, the new French-Russian dictionary by V.G. Gak and K.A. Ganshina and the Multitran electronic dictionary. The advantages and disadvantages of various types of dictionaries are considered. In the analyzed dictionaries there is an expansion of the semantic field. We are talking about words in which the development of the expressed meaning is noted as a result of historical, technical and scientific progress. There is no reduction in the semantic volume of lexical units in the Multitran dictionary. At the same time, the lexical meaning of words changes in the electronic dictionary. There is an increase in the number of lexical units in the New French-Russian Dictionary, as well as in the Multitran dictionary. This is due to the following factors: a change in the structure of the word as an object of social and cultural heritage; borrowing a word from another language; the emergence of new words to designate objects and phenomena that were previously absent in culture, science, technology and art. Some lexemes have seen a complete reduction in their semantic scope; in other words, some words have become obsolete and, in turn, have completely fallen out of use. Thus, some lexemes that are present in the dictionary of N.P. Makarov, were not included in the dictionaries of V.G. Gak and Multitran. We can note the appearance of a large number of borrowings and neologisms in the Multitran dictionary. The article also concludes about some advantages and disadvantages of the electronic dictionary in some respects.

A relaxor ferroelectric crystal based Two-DOF miniature piezoelectric motor with fish body structure

Multi-dimensional movements and miniaturization are required for robotic joints motion, multi-axis optical alignments and other multiple degree-of-freedom (DOF) actuation scenes. However, it is a challenge for piezoelectric motors to guarantee multi-DOF movements, miniaturization, high load capacity and high resolution simultaneously. Inspired by synergic movement of body and caudal fin of fish in nature and the construction idea of metamaterials, we proposed a two-DOF linear piezoelectric motor (4mmHeight × 3mmLength × 3mmWidth) based on the artificial elongation 31z and shear 35x/y mode by using Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIMNT) relaxor ferroelectric single crystal as piezoelectric elements. The results demonstrate that the motor is capable of achieving bidirectional motion in both X and Y axes, with the PIMNT crystal-based motor reaching a velocity of up to 94.8 mm/s. Its mechanical loading capacity per unit volume reaches as high as 1.39 mN/mm3, which exceeds the load capacity of currently reported two-DOF motors by 10 times. Moreover, it exhibits an exceptional step resolution of 5 nm, outperforming existing two-DOF motors by 1–2 orders of magnitude in terms of precision and accuracy. Furthermore, by modulating the driving signals of this motor, it can traverse any trajectory within the XY plane. The proposed ultrasonic motor has potential for applications in micro-robots, nano-precision motion, automatic visual systems and haptic interfaces.

Quantitative and qualitative assessment of a pituitary neuroendocrine tumor's T2-signal intensity in acromegaly - a call for unification.

The T2-signal intensity (SI) of somatotroph pituitary neuroendocrine tumors (sPitNET) is associated with treatment response and granulation pattern. Our aim was to evaluate SI assessment methods and their clinical implications, including responsiveness to preoperative first-generation somatostatin analogs (SSA). This single-center, observational study included unselected, consecutive patients with newly diagnosed acromegaly. Out of 109 treatment-naïve patients, 69 were eligible. The qualitative Visual Method involved a visual comparison of the sPitNET with the temporal gray matter. The Three Tissue Method compared the quantified SI of the sPitNET, temporal white matter, and gray matter. The signal intensity ratio of the sPitNET vs. gray matter (GM-SIR) was calculated. Tumors were divided into three groups: hyperintense (HYPER), isointense (ISO), and hypointense (HYPO) according to the Visual Method, Three Tissue Method, and GM-SIR. These groups were compared in terms of demographic, radiological, and biochemical features. The SI assessment methods were investigated for their ability to predict preoperative SSA responsiveness. SI assessment methods classified SI type correspondingly in 58-75.4% of cases. ISO constituted 39-49% of the analyzed sPitNETs. All methods identified significant differences in tumor volume between the SI groups, with HYPO being more biochemically active per tumor volume unit. According to the Three Tissue Method, patients with ISO had the youngest age at diagnosis and onset. According to the Visual Method, ISO had a lower chance of achieving insulin-like growth factor 1 (IGF1) normalization compared to HYPO (odds ratio (OR) 0.089, confidence interval (CI) 0.015-0.538, p= 0.008)), with no differences between HYPER and HYPO. Only the Visual Method predicted the IGF1 normalization after SSA. HYPER and ISO sPitNETs were classified in electron microscopy as both densely and sparsely granulated. Bihormonal tumors presented only as HYPO and ISO. According to the Three Tissue Method, no HYPO was diagnosed with sparse granulation. We demonstrated discrepancies between the SI assessment methods. The Visual Method predicted the outcome of preoperative treatment with SSA. Clinically, ISO behaved similarly to HYPER. Further studies are needed to unify SI assessment and improve its clinical applicability in acromegaly.

Unveiling Morphology-Structure Interplay on Hydrothermal WO3 Nanoplatelets for Photoelectrochemical Solar Water Splitting.

Photoelectrochemical (PEC) water splitting offers a sustainable route for hydrogen production, leveraging noncritical semiconductor materials. This study introduces a seed layer-free hydrothermal synthesis approach for semiconductor photoanodes based on tungsten trioxide (WO3) nanoplatelets. Aiming to boost the efficiency of photoelectrochemical water splitting through optimization of the synthesis parameters of bare WO3, focusing on temperature, time, and layer thickness, we systematically explored their effects on the morphological, structural, and optical characteristics of WO3 photoanodes. Combining a low-temperature regime (90 °C for 12 h) with a multilayer strategy (up to six-layers) resulted in significant improvements in photocurrent. Particularly, the five-layer sample exhibited a remarkable increase of over 70% compared to the single-layer photoanode. Morphological aspects, particularly the fractal dimension of nanoplatelets and the emergence of the (220) crystalline orientation, usually neglected, were found to play pivotal roles in modulating the PEC response. Rietveld refinement of X-ray diffraction patterns further underscored the importance of crystallographic facets, volume unit cell expansion, and microstrain in influencing photocurrent outcomes. Furthermore, we adapted the Mott-Schottky equation to incorporate the fractal dimension reflecting the nanostructures' nature, usually set to a planar interface. Our findings highlight the interchange between nanoplatelet morphology and structural parameters in determining the PEC efficiency of WO3 photoanodes.

DLP 3D printing of alumina catalyst architectures: Design, kinetics and modeling of structure effects on catalyst performance

The impact of the 3D structural design on the catalytic performance was investigated in this work. Four catalyst architectures (squared honeycomb, Schwartz P, face centered cubic and gyroid), made of alumina, were designed and printed with the Digital Light Processing (DLP) printing technology. The obtained shaped catalysts were loaded in a tubular reactor and their activities were evaluated in continuous ethanol dehydration to diethyl ether. The kinetic experiments revealed that both the conversion per unit of the reactor volume and the specific activity were highly affected by the selected design of the catalyst geometry. An advanced 1-D heterogeneous mathematical model employing geometrical features of the catalyst structures was proposed to describe the experimental data. The model included local variations of contact perimeters and cross-section areas to describe the periodic architectures. The assumption of plug flow pattern in the catalyst channels was revealed to be inadequate in predicting the structure effects, thus axial dispersion effects were included to obtain a successful and statistically significant description of the experimental observations. The proposed approach forms a solid basis to describe chemical processes operated with 3D printed catalyst structures.

Comparative Study on the Impact of Various Non-Metallic Fibres on High-Performance Concrete Properties

The performance of high-performance concrete has been enhanced in the present study by incorporating non-metallic fibres without altering the binder content. The impact of these fibres on high-performance concrete flexural and compression characteristics and the arrangement of fibres within the composite were systematically analysed. Unlike conventional practices, the authors of the research introduce various non-metallic fibres, including alkali-resistant glass fibres, carbon microfibers, three types of polypropylene microfibers, and one type of polyvinyl alcohol fibre while maintaining an equal amount of binder. The research aims to comprehensively evaluate the fibre’s influence on cement composite properties. Various types of non-metallic fibres, highlighting differences in diameters and their physical-mechanical properties with a constant amount by volume, have been considered in the research. Alkali-resistant glass and carbon fibres exhibit low values of residual post-cracking force but polyvinyl alcohol fibres demonstrate the best post-cracking behaviour, with a residual post-cracking force value. This detailed examination of fibre distribution and composition sheds light on the nuanced effects on fresh and hardened concrete properties. Notably, this work diverges from existing research by maintaining a constant binder amount and considering the quantitative distribution of fibres in a unit volume of the cement matrix, along with their aspect ratio. These findings provide valuable insights for selecting the most suitable non-metallic fibres for enhancing high-performance concrete properties.

Comparative experimental performance research on parameter optimization of foam metal radiators

As a new type of plate fin radiator, foam metal radiators can be widely applied in the automobile and petrochemical industry field. The foam metal fin structure has great influence on the heat exchange performance. In this paper, a parameterized optimization method to optimize the airside heat exchange structure of foam metal has been presented. Comparative experimental performance research on the initial and optimized foam metal radiators have been carried out. Results showed the unit volume heat dissipation rate and airside heat transfer coefficient of the optimized foam metal radiator compared with the initial radiator has a maximum increase of 6.5 % and 1.43 %, respectively, under the airflow rate from 800 m3/h to 2800 m3/h at the ambient pressure of 58 kPa and room temperature. The optimized radiator has the better overall performance at higher airflow rate, where the comprehensive evaluation factor (i.e. JF) of optimized radiator is larger than that of the initial radiator. The optimized radiator has better heat dissipation performance and needs lower fan power consumption under the same gas side resistance. The effectiveness of the parameter optimization method has been validated by experimental results and can be used to optimize the structure of foam metal radiator.

Elastocaloric Performance of Natural Rubber in Solid State Cooling: Evaluation of the Effect of Crosslinking Density

Elastocaloric cooling is recognized as a promising alternative to modern vapor-compression cooling systems, which often rely on environmentally hazardous refrigerants. Natural rubber (NR), a well-known renewable resource, stands out among elastomers exhibiting elastocaloric behavior due to a peculiar combination of nontoxicity, low cost, softness, long-life fatigue and high caloric power. Despite these properties, research on the refrigeration potential of NR is still in its early stages, and several aspects require attention. This work investigates, for the first time, the effect of crosslinking density on the elastocaloric properties of NR. Samples with three different crosslinking densities (2.9, 4.0 and 5.2 mol·10−4/cm3) were produced by internal compounding and hot pressing, and thermo-mechanically characterized. The assessment of the elastocaloric effect of the produced samples revealed that reducing the crosslinking degree significantly enhanced the elastocaloric properties. To compare the cooling capacity of the samples, a qualitative coefficient of performance (COPmat) was evaluated as the ratio between extracted thermal energy and deformational work per unit volume. The results highlight that the least crosslinked sample achieved the higher COPmat, equal to 2.4. These results underscore the significance of crosslinking density as one of the primary factors to be considered to enhance the refrigeration potential of NR.

Design of A PFR For the Production of 1,000,000 Tons Per Year of Ethyl Acetate from Esterification of Acetic Acid and Ethyl Alcohol

The research considered the design or size of a plug flow reactor for the production of 1,000,000 tons of ethyl acetate per year from the esterification of acetic acid and ethyl alcohol in the presence of an acid catalyst. The PFR design models for volume, height, diameter, space time, space velocity, quantity of heat generated, quantity of heat generated per unit volume of the reactor as well as the temperature effect models were developed using the conservation principle of mass and energy at steady state operation of the reactor. The developed models were simulated using MATLAB at initial feed and operating temperature of 299.830k and 343.15k respectively and fractional conversion variation between 0 to 0.95 at an interval of 0.05. At a maximum conversion of 0.95, the PFR size specification for volume, height, diameter, space time, space velocity, quantity of heat generated and the quantity of heat generated per unit volume of the reactor was 15.2774m3, 4.2691m, 2.1346m, 2.9956sec., 0.3338sec-1, 12821.5800j/s and 839.2536j/sm3 respectively. The effect of the operating parameters on the performance or functional parameters of the reactor are presented in profiles as shown in figure 2 to 12 and the profile behaviour or trend were in agreement with process behaviour of PFR steady state operation in various literatures. The research have shown that in order to ensure sustainability and continuous production of ethyl acetate to meet the global demand of the economic and viable product, the plug flow reactor have demonstrated a good performance characteristics as a reacting media for the esterification process especially in the energy efficiency of the process as well as the product yield.

Fingering inhibition triggered by CO2 dissolution and viscosity reduction in water-alternating-CO2 injection

As a CO2 capture, utilization, and storage (CCUS) technology, water-alternating-CO2 (WAG) injection has demonstrated excellent results in enhancing oil recovery. Current research on WAG injection primarily focused on factors such as increasing injection pressure and optimizing the water–gas slug ratio (W:G) to enhance the driving force, reduce instability due to the significant viscosity difference between oil and CO2, thereby inhibiting fingering phenomenon and improving oil recovery. However, in immiscible flooding, CO2 dissolution reduces the viscosity of the oil, changing the instability of the interfaces and affecting oil recovery. We employed computational fluid dynamics to study the effect of CO2 dissolution and viscosity reduction on fingering patterns and its effect on enhanced oil recovery (EOR) under capillary numbers Ca = 0.12 × 10−2–1.14 × 10−2 and W:G = 1:3–3:3. The results indicated that: (1) the dissolution of CO2 reduced oil viscosity, inhibiting the fingering phenomenon, promoting stable displacement and enhancing oil recovery. (2) The viscosity reduction effect of CO2 dissolution was more effective in viscous fingering. (3) Analysis of the EOR capacity after injecting a unit volume of displacement fluid confirmed that the optimal W:G remains 1:3. These findings highlight the importance of considering CO2 dissolution and its viscosity reduction effect to optimize WAG injection strategies for enhanced oil recovery.