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In this study, rose oil was encapsulated with stearic acid substituted polyvinyl alcohol macromolecule. In the first part of the study, stearic acid substituted polyvinyl alcohol macromolecule was synthesized and its chemical structure was elucidated by ATR-FTIR and ¹HNMR. Then, rose oil was encapsulated using this obtained polymer. The chemical structure of the obtained capsules was made by ATR-FTIR, and dimensional analysis was done by scanning electron microscope (SEM). After the obtained capsules, a paper coating formula was prepared and coated on 80 g/m² paper. The resulting scented papers were printed using the screen printing technique. The color, gloss, and deformation of the capsules on the surface of the printed and unprinted papers were determined by spectrophotometer, glossmeter and SEM. As a result, it was determined that the synthesized polymer could encapsulate the rose oil and the papers using these capsules could be printed without deformation. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to digitally measure the dimensional changes in an irreversible hydrocolloid impression material (alginate) resulting from varying storage times under optimal storage conditions. Materials and methods: A single type V dental stone control cast was used to make 25 alginate impressions using perforated stock trays. The impressions were randomly assigned into five groups of five samples each (n=5 per group) with varying storage times: Group 1, poured at 15 minutes; Group 2, poured at one hour; Group 3, poured at 24 hours (one day); Group 4, poured at 72 hours (three days); Group 5, poured at 168 hours (seven days). All impressions were stored in sealed Ziploc® plastic bags with a wet paper towel (100% relative humidity) at room temperature and stored according to the assigned group storage times. All impressions were poured in type V dental stone according to the manufacturer's instructions. The casts were scanned with a digital 3D desktop scanner and saved as electronic stereolithography (.stl) files. Each.stl file of the scanned casts were superimposed on the.stl file of the control cast using Geomagic® Control X™ software. Three preselected fixed comparison measuring points (CMP) on each cast were compared to the control cast. Point one (CMP1) was on the midfacial surface of central incisor. Point two (CMP2) and point three (CMP3) were on the mesiobuccal proximal marginal ridge areas of third molars. The discrepancies between the files at each point were analysed with colour maps, and quantified (Table 1). The tolerance was set at ±10μm. CMP scores were analysed using one-way analysis of variance (ANOVA) and Kruskal-Wallis (K-W) non-parametric H tests. Results: Average gap distances across groups ranged from 0.04mm (seven-day group) to 0.06mm (one hour and 24-hour groups). Colour maps indicated increased dimensional change with increased storage time up to one day. After three days, shrinkage up to 139μm was measured. ANOVA results for CMP1 (F[4,20] = 1.65, p = 0.020) and CMP3 (F[4,20] = 0.44, p = −0.78) were not statistically significant. Similarly, K-W results for CMP2 were not significant (χ2= 3.62, p = 0.46). Conclusions: Under optimal storage conditions, there were no significant dimensional changes in casts poured from alginate up to seven days. [ABSTRACT FROM AUTHOR]

This paper provides a corrected formulation to the mixed integer programming model proposed by Aydogan et al. (2012) [1] . They proposed a genetic algorithm to learn fuzzy rules for a fuzzy rule-based classification system and developed a Mixed Integer Programming model (MIP) to prune the generated rules by selecting the best set of rules to maximize predictive accuracy. However, their proposed MIP formulation contains errors, which are described in this technical note. We develop corrections and improvements to the original formulation and test it with non-parametric statistical tests on the same data sets used to evaluate the original model. The statistical analysis shows that the results of the correction formulation are significantly different from the original model. [ABSTRACT FROM AUTHOR]

This document is a closure response to a discussion on the topic of "Steady Flow through Gated Circular Culverts: Hydraulic Operation and Experiments." The authors express gratitude for the comments and supplementary analysis provided by the discussers. The main objective of the original paper was to develop a flow classification for steady flows through gated culverts and to study a comprehensive laboratory data set. The authors clarify certain points raised in the discussion and emphasize that their purpose was not to produce calibration to the experiments, but rather to group and describe the linked physical conditions. They also acknowledge the reanalysis of their experimental data by another model and discuss the potential impact of switching dimensionless variables on the adjustment of empirical parameters. Overall, the authors believe that a comprehensive flow classification will contribute to a better understanding of the hydraulics of steady flow solutions in gated culverts. [Extracted from the article]

Industry Foundation Classes (IFCs), as the most recognized data schema for Building Information Modeling (BIM), are increasingly combined with ontology to facilitate data interoperability across the whole lifecycle in the Architecture, Engineering, Construction, and Facility Management (AEC/FM). This paper conducts a bibliometric analysis of 122 papers from the perspective of data, model, and application to summarize the modes of IFC and ontology integration (IFCOI). This paper first analyzes the data and models of the integration from IFC data formats and ontology development models to the IfcOWL data model. Next, the application status is summed up from objective and phase dimensions, and four frequent applications with maturity are identified. Based on the aforementioned multi-dimensional analysis, three integration modes are summarized, taking into account various data interoperability requirements. Accordingly, ontology behaves as the representation of domain knowledge, an enrichment tool for IFC model semantics, and a linkage between IFC data and other heterogeneous data. Finally, this paper points out the challenges and opportunities for IFCOI in the data, domain ontology, and integration process and proposes a building lifecycle management model based on IFCOI. [ABSTRACT FROM AUTHOR]

With the extensive development of big data and social networks, the user profile field has received much attention. User profiling is essential for understanding the characteristics of various users, contributing to better understanding of their requirements in specific scenarios. User-generated contents which directly reflect people's thoughts and intention are a valuable source for profiling users, among which user reviews by nature are invaluable sources for acquiring user requirements and have drawn increasing attention from both academia and industry. However, review-based user profiling (RBUP), as an emerging research direction, has not been systematically reviewed, hindering researchers from further investigation. In this work, we carry out a systematic mapping study on review-based user profiling, with an emphasis on investigating the generic analysis process of RBUP and identifying potential research directions. Specifically, 51 out of 2478 papers were carefully selected for investigation under a standardized and systematic procedure. By carrying out in-depth analysis over such papers, we have identified a generic process that should be followed to perform review-based user profiling. In addition, we perform multi-dimensional analysis on each step of the process in order to review current research progress and identify challenges and potential research directions. The results show that although traditional methods have been continuously improved, they are not sufficient to unleash the full potential of large-scale user reviews, especially the use of heterogeneous data for multi-dimensional user profiling. [ABSTRACT FROM AUTHOR]

To solve the problem where the prediction formula for vibration velocity by dynamic compaction cannot fully reflect the elevation amplification effect, the elevation amplification effect of vibration velocity by dynamic compaction was studied theoretically, and the factors that influence the elevation amplification effect of vibration velocity by dynamic compaction were systematically analyzed in this paper. The elevation amplification effect of a loess high slope under dynamic compaction is coformed by the refraction and reflection superposition effect of dynamic compaction vibration waves at the soil layer interface and the diffraction effect of dynamic compaction vibration waves. The propagation path of dynamic compaction vibration waves in soil was analyzed, and the elevation amplification effect was verified theoretically. The related physical quantities that affected the dynamic compaction vibration velocity of a loess high slope were analyzed based on the dimensional analysis method, and the calculation and improved calculation formulas that considered the elevation amplification effect of dynamic compaction vibration velocity were obtained. The multiple regression analysis of the calculation and improved calculation formula that considered the elevation amplification effect of the dynamic compaction vibration velocity was carried out using MATLAB with engineering examples. The results show that the relative error of the two formulas is small when the elevation difference is small; when the elevation difference is large, the calculation accuracy of the improved calculation formula that considered the elevation difference is higher, and it is more in line with the actual situation. Finally, according to the selected maximum allowable value of the slope particle velocity (e.g., 1.5, 2.0, and 2.5 cm/s), the allowable safe distance for dynamic compaction on a loess high slope is proposed area of northern Shaanxi Province, China. The results of this paper could provide a reliable basis for predicting vibration velocity by dynamic compaction in the Loess Plateau area of northern Shaanxi Province, China. They might have a reference value for dynamic compaction vibration control under similar terrain environments with large elevation differences and provide a safe guide for a dynamic compaction construction site in the Loess Plateau area of northern Shaanxi Province, China. [ABSTRACT FROM AUTHOR]

The Authors presented an interesting technique to decrease the errors of estimating the outflow from radial gates through the "calibration method" under submerged flow conditions. Under partially submerged flow, the I MARE i values for discharge prediction by Eq. (14) of the original paper, compared with Bijankhan et al. ([1]), increased from 3.2% to 4.2% for music note and from 5% to 5.3% for hard rubber gates. Notation Graph HT ht combined parameter of relative gate opening and submergence ratio (-) Graph HT ht jet Froude number at vena contracta (-) I n i number of data sets (-) Graph HT ht measured discharge (m SP 3 sp s SP -1 sp ) Graph HT ht predicted discharge (m SP 3 sp s SP -1 sp ) Graph HT ht gate opening (m) Graph HT ht submergence ratio (-) Graph HT ht upstream flow depth (m) References 1 Bijankhan, M., Ferro, V., & Kouchakzadeh, S. (2013). [Extracted from the article]

In this paper, the outflow process of a linear width contraction device for a free-flow condition is modeled using the dimensional analysis and the incomplete self-similarity condition. The proposed theoretical stage-discharge relationship is tested using measurements available in the literature. The proposed power stage-discharge equation is characterized by a value of the exponent close to 2 and a coefficient depending on the angle of the device sides with the channel bank. The proposed flume is characterized by simple construction, easy installation, low cost, and a good accuracy of the measured discharge (errors in the estimate ranging from − 3.84 to 1.9%). The deduced stage-discharge equation is characterized by errors in the estimate of discharge lower than or equal to ± 3% for 93.7% of the investigated cases. The main result of this paper is a stage-discharge relationship giving an accurate estimate of discharge but, at the same time, having the advantage of working regardless of the discharge coefficient estimate. [ABSTRACT FROM AUTHOR]

When studying the damage law of reinforced concrete building structures under explosive loading, the direct experimental cost is too high and numerical simulations take a long time. Based on the theoretical analysis, the dimensional analysis model of reinforced concrete members under explosive loading can be used to study the damage law of reinforced concrete members under explosive loading. It provides guidance, reduces the number of tests, improves the efficiency of the test, and has certain research significance. In this paper, a typical reinforced concrete column is taken as the main research object. Based on the dimensional analysis method, the relationship between the damage to the reinforced concrete column and the explosion equivalent and explosion distance under explosion loading is studied. The finite element simulation software LS-DYNA 18.2 is used to determine the function relationship between the disturbance in the column and the proportional explosion distance. The results show that when the proportional explosion distance Z is greater than 0.0693 m/kg1/3, the center disturbance of the blasting surface of the reinforced concrete column has a linear relationship with the reciprocal of the proportional explosion distance. The linear relationship can be used to predict the column's center disturbance under partial explosion conditions, which provides guidance for studying the damage criterion of reinforced concrete under explosion loading. [ABSTRACT FROM AUTHOR]

In the research and development of technology and equipment for bamboo products deep processing, such as filling, drying, and medicinal use of bamboo flour (BF), the poor compaction and fluidity of BF materials entails the need for accurate discrete element model (DEM) and BF parameters to provide a reference for the simulation of BF processing operationsand the development of related equipment. The average particle size of the 5 types of BFs ranges from 0.136 mm to 0.293 mm, and the small particle size of BF particles causes to the number of BF particles in bamboo processing equipment to reach tens of millions or even billions. When conventional methods are used for simulation, ordinary computers cannot provide the required computing power. To address the aforementioned challenges, this paper proposes a calibration method for the discrete element contact parameters of BFs based on dimensional analysis and a back propagation (BP) neural network. Using particle scaling theory and dimensional analysis methods, the average particle size of the BF was increased to 1 mm, and the main discrete element contact parameters of the five types of BF to be tested were used as input layers. The injection method and sidewall collapse method were used to obtain the angle of repose (AR) as the output layer. Fifty groups were randomly selected using MATLAB for EDEM simulation, and the simulation results were trained using the BP neural network algorithm; an ideal neural network model was obtained, the discrete element parameters of different BFs were predicted, and physical experiments were performed to verify two types of AR and mold hole compression under calibrated parameters. The relative error between the simulated AR obtained through calibration parameters and the physical experimental values is less than 2.3%. Through BF parameter validity verification, the simulated maximum compression displacement and compression ratio after stabilization were 34.81 mm and 0.477, which were close to the actual experimental results of 34.77 mm and 0.461, respectively, verifying the accuracy of the neural network prediction model. The research results provide a reference for the simulation of BF processing operations and the development of related equipment. [ABSTRACT FROM AUTHOR]

When testing biological samples with atomic force microscopy (AFM) nanoindentation using pyramidal indenters, Sneddon's equation is commonly used for data processing, approximating the indenter as a perfect cone. While more accurate models treat the AFM tip as a blunted cone or pyramid, these are complex and lack a direct relationship between applied force and indentation depth, complicating data analysis. This paper proposes a new equation derived from simple mathematical processes and physics-based criteria. It is accurate for small indentation depths and serves as a viable alternative to complex classical approaches. The proposed equation has been validated for ℎ < 3R (where h is the indentation depth and R is the tip radius) and confirmed through simulations with blunted conical and pyramidal indenters, as well as experiments on prostate cancer cells. It is a reliable method for experiments where the tip radius cannot be ignored, such as in shallow indentations on thin samples to avoid substrate effects. [ABSTRACT FROM AUTHOR]

This paper introduces an enzymatic approach to estimate internal mass-transfer resistances during food digestion studies. Cellulase has been used to degrade starch cell walls (where cellulose is a significant component) and reduce the internal mass-transfer resistance, so that the starch granules are released and hydrolysed by amylase, increasing the starch hydrolysis rates, as a technique for measuring the internal mass-transfer resistance of cell walls. The estimated internal mass-transfer resistances for granular starch hydrolysis in a beaker and stirrer system for simulating the food digestion range from 2.2 × 107 m−1 s at a stirrer speed of 100 rpm to 6.6 × 107 m−1 s at 200 rpm. The reaction rate constants for cellulase-treated starch are about three to eight times as great as those for starch powder. The beaker and stirrer system provides an in vitro model to quantitatively understand external mass-transfer resistance and compare mass-transfer and reaction rate kinetics in starch hydrolysis during food digestion. Particle size analysis indicates that starch cell wall degradation reduces starch granule adhesion (compared with soaked starch samples), though the primary particle sizes are similar, and increases the interfacial surface area, reducing internal mass-transfer resistance and overall mass-transfer resistance. Dimensional analysis (such as the Damköhler numbers, Da, 0.3–0.5) from this in vitro system shows that mass-transfer rates are greater than reaction rates. At the same time, SEM (scanning electron microscopy) images of starch particles indicate significant morphology changes due to the cell wall degradation. [ABSTRACT FROM AUTHOR]

Heat dissipation has emerged as a critical challenge in server cooling due to the escalating number of servers within data centers. The potential of immersion jet technology to be applied in large-scale data center server operations remains unexplored. This paper introduces an innovative immersion jet liquid cooling system. The primary objective is to investigate the synergistic integration of immersion liquid cooling and jet cooling to enhance the heat dissipation capacity of server liquid cooling systems. By constructing a single-server liquid cooling test bench, this study compares the heat dissipation efficiencies of pure immersion and immersion jet liquid cooling systems and examines the impact of inlet water temperature, jet distance, and inlet water flow rate on system performance. The experimental outcomes show that the steady-state surface heat transfer coefficient of the immersion jet liquid cooling system is 2.6 times that of the pure immersion system, with increases of approximately 475.9 W/(m2·K) and 1745.0 W/(m2·K) upon adjustment of the jet distance and flow rate, respectively. Furthermore, the system model is streamlined through dimensional analysis, yielding a dimensionless relationship that encompasses parameters such as inlet water temperature, jet distance, and inlet water velocity. The correlation error is maintained below 18%, thereby enhancing the comprehension of the immersion jet cooling mechanism. [ABSTRACT FROM AUTHOR]

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The theory of scaling called finite similitude does not involve dimensional analysis and is founded on a transport-equation approach that is applicable to all of classical physics. It features a countable infinite number of similitude rules and has recently been extended to other types of governing equations (e.g., differential, variational) by the introduction of a scaling space Ω β , within which all physical quantities are deemed dependent on a single dimensional parameter β . The theory is presently limited to physical applications but the focus of this paper is its extension to other quantitative-based theories such as finance. This is achieved by connecting it to an extended form of dimensional analysis, where changes in any quantity can be associated with curves projected onto a dimensional Lie group. It is shown in the paper how differential similitude identities arising out of the finite similitude theory are universal in the sense they can be formed and applied to any quantitative-based theory. In order to illustrate its applicability outside physics the Black-Scholes equation for option valuation in finance is considered since this equation is recognised to be similar in form to an equation from thermal physics. It is demonstrated that the theory of finite similitude can be applied to the Black-Scholes equation and more widely can be used to assess observed size effects in portfolio performance. [ABSTRACT FROM AUTHOR]

Featured Application: Additive Manufacturing (AM) represents new and very promising manufacturing processes. The results can be applied immediately in the manufacturing industry in order to obtain significant decreases of the costs in some specific domains. By means of its facilities, AM brings several advantages in comparison with the classical manufacturing technologies. Nowadays, there are a huge number of unexplored directions, which assure AM will become a very powerful manufacturing process in the next period, with an undoubted low cost and reduced material consumption, as well as optimal stiffness and competitiveness technology. Between the unexplored (or less-explored) directions, one has to mention the dimensional methods' involvement in gaining an optimal, highly competitive final product. This means that instead of the real structural element, named the prototype, the engineers will perform high-accuracy tests on the attached reduced-scale models, whose experimental results are extended to the prototype by means of the deduced model law (ML). The authors, based on their previous theoretical research as well as experimental investigations, offer a new approach, which is less implemented in AM technologies. Based on the obtained results, these dimensional methods are very promising, especially the last one, the so-called Modern Dimensional Analysis (MDA), conceived by Thomas Szirtes and described in the following paper. Starting with the nowadays-applied dimensional methods' critical analysis, the authors will present evidence for the advantages of MDA, especially on the polymer-based AM technology. They will prove that MDA represents a very promising, as well as easy approach, which through its implementation can offer a higher competitiveness for AM technologies. As an illustration of the advantages of MDA, the authors conceived several MDA approaches for a given structural element's case (a cantilever beam, with an internal-ribbed structure loaded at its free end by means of a vertical concentrated load), which, through their high accuracy in experimental-validated MLs, offer very good accuracy in model–prototype correlation. The deviations between the effective measured values of the displacements on the prototypes and those predicted, based on the values of the measurements on the models assigned to the prototypes by the validated MLs, were 1.06, 1.60, and 2.35%, respectively. In the authors' opinion, MDA can represent a starting point for conceiving a highly competitive product with an optimal filling, as well as the deposition of layers using AM technologies. Based on the authors' best knowledge, up to this moment, it seems that this engineering area does not fully apply the advantages of MDA, only in few limited cases, analyzed in the following. [ABSTRACT FROM AUTHOR]

10.1119/5.0133767.1 Timescales spanning 24 orders of magnitude smaller than one second can be studied experimentally, and each range is packed with different physical phenomena. This rich range of timescales offers a great context for an innovative undergraduate physics course which introduces modern physics and technology from an unconventional perspective. Based on the author's experience in lecturing on these topics to different audiences, this paper proposes a syllabus of a semester-long timescale-based undergraduate physics course. Editor's Note: Did you know that state-of-the-art experiments could measure timescales down to a few rontoseconds (such things do actually exist and correspond to 10 − 27 s)? In the spirit of Physics for Future Presidents, this paper uses the theme of fast timescales to build a semester-long syllabus to introduce undergraduate science majors to various physics concepts, ranging from condensed matter to particle physics, and to examples of commonly used technology (ink-jet printing, ultrasound imaging, high-speed cameras, etc.). Such a course could also be used for outreach, and it emphasizes the use of dimensional analysis and orders of magnitude. [ABSTRACT FROM AUTHOR]

Hydraulic structures at river crossings, especially culverts in ephemeral streams, are susceptible to damage during floods due to culvert scour, caused by various factors. It is essential to implement preventive measures to ensure the longevity and safety of these structures. This paper aims to present a comprehensive review of the factors influencing local scour downstream of culverts, offering a thorough understanding of this phenomenon. Consequently, a thorough review of the experimental studies and their corresponding outcomes documented in the literature is conducted. The analysis is divided into two main sections. The first section discusses dimensional analysis, while the second section delves into the key parametric factors affecting scouring, including flow regime, scour time, and experimental studies documented in the literature. The methods used in the second section are categorized into three distinct categories: channel and culvert dimensions, flow conditions, and sediment characteristics. This article not only provides a platform for researchers to conduct laboratory research but also assists hydraulic engineers in identifying crucial factors in culvert design. [ABSTRACT FROM AUTHOR]

This paper introduces a rigorous and comprehensive approach to the assessment of marine shafting systems through the utilization of an advanced π-Theorem-based scaling methodology. Integrating journal-bearing similarity assessment and shaft-line scaling methodology with advanced dimensional analysis, the study aims to provide a methodology foundation for systematic replication and analysis of marine shafting systems through scaled models. The proposed scaling methodology ensures geometric and mechanical similarity in terms of shaft-line deflection, considering key scaling parameters such as shaft length, diameter, weight, loads, rotational speed, material properties, bearing locations, and offsets. The advanced dimensional analysis computes specific non-dimensional ratios to guarantee a close resemblance between a real-size system and a scaled lab model. The methodology is analytically derived and validated with numerical simulations for a case study, conducting comparative analysis, evaluating discrepancies, and utilizing the integrated framework for experimentation. [ABSTRACT FROM AUTHOR]

Many advanced driver assistance schemes or autonomous vehicle controllers are based on a motion model of the vehicle behavior, i.e., a function predicting how the vehicle will react to a given control input. Data-driven models, based on experimental or simulated data, are very useful, especially for vehicles difficult to model analytically, for instance, ground vehicles for which the ground-tire interaction is hard to model from first principles. However, learning schemes are limited by the difficulty of collecting large amounts of experimental data or having to rely on high-fidelity simulations. This paper explores the potential of an approach that uses dimensionless numbers based on Buckingham's π theorem to improve the efficiency of data for learning models, with the goal of facilitating knowledge sharing between similar systems. A case study using car-like vehicles compares traditional and dimensionless models on simulated and experimental data to validate the benefits of the new dimensionless learning approach. Preliminary results from the case study presented show that this new dimensionless approach could accelerate the learning rate and improve the accuracy of the model prediction when transferring the learned model between various similar vehicles. Prediction accuracy improvements with the dimensionless scheme when using a shared database, that is, predicting the motion of a vehicle based on data from various different vehicles was found to be 480% more accurate for predicting a simple no-slip maneuver based on simulated data and 11% more accurate to predict a highly dynamic braking maneuver based on experimental data. A modified physics-informed learning scheme with hand-crafted dimensionless features was also shown to increase the improvement to precision gains of 917% and 28% respectively. A comparative study also shows that using Buckingham's π theorem is a much more effective preprocessing step for this task than principal component analysis (PCA) or simply normalizing the data. These results show that the use of dimensionless variables is a promising tool to help in the task of learning a more generalizable motion model for vehicles, and hence potentially taking advantage of the data generated by fleets of vehicles on the road even though they are not identical. [ABSTRACT FROM AUTHOR]

A single-phase incompressible bicomponent transient oil mixing model was established based on the mechanism of flow, heat, and mass transfer of refined oils to obtain the flow field and concentration distribution of the component at the mixed segment during the batch transportation process. A new model for the axial diffusion coefficient was proposed, which included the turbulent diffusion coefficient and the coefficients derived from the differences in fluid physical properties. The new diffusion coefficient calculation formula presented in this paper could make the error very small when the calculated concentration distribution value of the mixing section is compared with the experimental value. Based on the many factors that affect the flow features during the oil replacement process in the mixed-oil section, the main dimensionless parameters (Reynolds, Peclet, Prandtl, Richardson, Schmidt) are selected by using the dimensional analysis method. The mixed segment had a high Pr and Pe. With an increasing concentration of lighter oil, the Pr decreased while the Pe and Re increased. The Ri was always less than 1, which implied that the buoyancy is not important, and the gravity effect can be ignored during the generation process of oil mixing according to the definition of Ri that buoyancy is dominant when it is greater than 1. The change of Sc versus the concentration of gasoline was small, and Sc was always close to 100, which indicated that the momentum diffusion was greater than the mass diffusion in the process of oil mixing. Sensitivity analysis was carried out based on the tailing amount and tailing length of the mixed section. It was concluded that the influence of pipe diameter, flow rate, temperature, and diffusion coefficient on the tailing amount and tailing length had the same trend. A single-phase incompressible two-component transient oil-mixing model is established to obtain the flow field and component concentration distribution in the mixing section during batch transportation in this paper. The flow characteristics and tailing phenomena of the mixed-oil section are determined by studying the dimensionless numbers (Reynolds, Peclet, Prandtl, Richardson, Schmidt) in the oil change process of the mixed-oil section. The experimental results could predict the distribution of oil mixture concentration under specific working conditions. The influences of the difference of oil physical properties, turbulence effect as well as the adsorption effect of the pipe wall on the distribution of oil mixture concentration have also been discussed. The research results show that this technology provides the location and concentration distribution of the mixed oil segment when it is applied to practical cases, which gives technical support for detecting and cutting the mixed oil segment during the process of batch transportation and also guides the accurate cutting of the mixing segment. [ABSTRACT FROM AUTHOR]

Assessing sensitivity to unmeasured confounding is an important step in observational studies, which typically estimate effects under the assumption that all confounders are measured. In this paper, we develop a sensitivity analysis framework for balancing weights estimators, an increasingly popular approach that solves an optimization problem to obtain weights that directly minimizes covariate imbalance. In particular, we adapt a sensitivity analysis framework using the percentile bootstrap for a broad class of balancing weights estimators. We prove that the percentile bootstrap procedure can, with only minor modifications, yield valid confidence intervals for causal effects under restrictions on the level of unmeasured confounding. We also propose an amplification—a mapping from a one-dimensional sensitivity analysis to a higher dimensional sensitivity analysis—to allow for interpretable sensitivity parameters in the balancing weights framework. We illustrate our method through extensive real data examples. [ABSTRACT FROM AUTHOR]

Introduction: In this study, the spatial bending vibration of macro- and/or micro- scale cantilevered fluid-conveying pipes is investigated through finite dimensional analysis. Methods: Firstly, the Galerkin method is employed to discretize the partial differential equations of motion of the system into a system of ordinary differential equations. Then, the projection method based on center manifold- normal form theory is adopted to derive the coefficient formula that determines the pipe's nonlinear dynamic behaviors, i.e., the change rate of the real part of the critical eigenvalue with respect to the flow velocity and the nonlinear resonance term, thereby obtaining reduced-order equations. Compared to previous studies that relied on the numerical solution of ordinary differential equations to determine the existence and stability of periodic motion, this paper concludes the existence and stability of periodic motion by utilizing the coefficients of the Galerkin discretized equations and the reduced-order equations, significantly saving time in determining the dynamic properties of pipes. Results and discussion: Subsequently, by investigating the reduced-order equations under specific parameters, the existence and stability of the two types of periodic motion of the pipe are studied. For macro pipes, the truncated mode numbers are set incrementally to calculate the coefficients of the reduced-order equations, investigate the distribution of the stability of the two types of periodic motions with the mass ratio, and carry out a longitudinal comparison (i.e., the comparison between the results obtained under different truncated mode numbers) as well as a horizontal comparison (i.e., the comparison of results between the finite dimensional analysis and the infinite dimensional analysis). It is found that the reasonable truncated mode number required to study this type of system is 15. Previous studies primarily focused on the convergence of frequency and amplitude when determining the truncated mode numbers. On this basis, our study further examines the convergence of motion forms with respect to the truncated mode numbers. Finally, based on the Galerkin discretization equations of 15 modes, the distribution of the stability of two types of the periodic motion of micro pipes with the mass ratio is analyzed. For macro- and micro-scale pipes, when the truncated mode number is 15, the error between the finite dimensional analysis results and the infinite dimensional analysis results is calculated to be about 7%. The above results are verified by obtaining the numerical solution to Galerkin discretization equations. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study on the dimensional accuracy analysis of models produced by 3D printing technology—Fused Filament Fabrication (FFF). Geometric measurements were conducted using a dial caliper, a 3D scanner and a coordinate measuring machine. In addition, a statistical analysis of the test results was carried out, considering the division into different numbers of test samples (3, 5, 10, 20, 30). The analysis of the test results made it possible to assess the influence of the measuring tools used and the number of samples tested on the final measurement result, as well as to determine the consequences associated with it. [ABSTRACT FROM AUTHOR]

This paper introduces Buckingham's theorem in the context of Non-Destructive Testing & Evaluation (NDT&E). Its application leads to easier problems to handle by reducing the number of variables involved. In this sense, dimensional analysis can provide the foundation for in-line, real-time and low-cost inspection methods that are fully compatible with the requirements of the Industry 4.0 and NDE 4.0 paradigms. In order to show the impact of the Buckingham's theorem in NDT&E, we consider a practical case of interest, i.e. the simultaneous estimation of thickness and electrical conductivity of metallic plates via Eddy Current Testing. An initial numerical analysis is carried out with the aim to show the metrological performance of the method. The results obtained show that the method combines good accuracy with low computational costs. [ABSTRACT FROM AUTHOR]

This article reports on a new Multi-dimensional model of graduate student coursework writing in two applied science disciplines from a corpus containing 1,108 texts and 2,008,316 words. The Exploratory Factor Analysis (EFA) revealed five dimensions: (1) Conceptual Information vs. Process-Focused Actions (2) Human/Subjective- vs. Entity/Objective- Focus, (3) Attitudinal Monoglossia vs. Precisely Measured Information, (4) Social vs. Physical Science Approaches, and (5) Speculative vs. Finalized Events. The dimensions are analyzed functionally in terms of both register and discipline. The results demonstrate that course papers exhibit distinct patterns of language use, often attributed to the varying purposes of the texts but also related to disciplinary ways of knowing. Findings have implications for disciplinary writing research and representativeness of student writing corpora while contributing to an exploration of register as a continuous construct. The research provides an enhanced understanding of academic coursework writing for stakeholders such as professors, graduate students, writing consultants. (150 words) [ABSTRACT FROM AUTHOR]

Dimensional analysis is a tool used to understand and analyze various problems in engineering. This analysis is useful for calculating dimensionless parameters and gives an answer as to which group of parameters affects the problem. Dimensional analysis can be represented using Buckingham's p-theorem. This paper provides an overview of the literature on the application of dimensional analysis and Buckingham's p theorem for various processing processes. The review period is observed in the period from 2007 until today. The main focus remains of the production process, performance and parameters of process, dimension and years of publication. Review work in this area aims to provide ready-made information in one place that can be very useful to future researchers in this direction of research. [ABSTRACT FROM AUTHOR]

Cationic collectors are widely used in the flotation of iron ore, silicate, oxides, and so forth. At this stage, so much research has been carried out on flotation column cells, but more attention needs to be paid to the hydrodynamic properties in the presence of cationic collectors in cells. In order to study foaming performance and hydrodynamic characteristics in the presence of GE609, the bubble characteristics are studied in an experimental scale flotation column. A high‐speed camera recorder is used to take bubbles' images, and the bubble size and shape under different conditions is measured by image analysis. This paper aims to explore the effect of dispersed gas and continuous liquid velocities on the bubble size and aspect ratio at different axial heights in a countercurrent flotation column in the presence and absence of GE609. In the systems, the bubble size distributions and shapes at different axial positions were obtained by using high‐speed camera technology in the superficial gas velocity (Ug) ranges of 0.0021–0.0106 m/s and superficial liquid velocity (UL) ranges of 0.00123–0.00209 m/s. Through the comparison with relevant papers and studying the experiment data, the relationship between the Sauter mean diameter and Ug, UL and axial heights have been analyzed by using multiple linear regression and dimensional analysis. The experimental data have been adopted to establish the correlation between the bubble diameter and the dimensionless array, which have been compared with other literature. And the predicted values/results of Weber and Morton number correlation in this work are relatively close to the experimental values. [ABSTRACT FROM AUTHOR]

Hydraulic conductivity determination plays an essential role in the investigation of groundwater flow regime which can then influence many field problems such as pumping capabilities in the area, transport of contaminant or heat and soil internal erosion. Numerous equations based on dimensional analysis or experimental measurements have been published since the end of the 19th century for the determination of hydraulic conductivity. However, not all of these formulae are applicable for every material and all of them bring some uncertainty in the value of hydraulic conductivity. This paper contains a description of experimental research carried out concerning the determination of hydraulic conductivity for four types of sand with different grain size distribution curves and variable porosity. Obtained values of hydraulic conductivity ranged from 1·1004 to 4·1003 according to the sample porosity. The series of experiments consisted of 160 separate tests conducted in order to obtain relevant statistical sets. In this paper, the experimental data are discussed and compared with hydraulic conductivities obtained from 6 empirical formulae recommended in a previous study. The comparison showed that some empirical formulae provide a good agreement with the experimental data (the most precise were formulae published by Terzaghi and by Sauerbrey). However, some formulae showed high deviation from measured data (formula published by Zamarin). [ABSTRACT FROM AUTHOR]

Void fraction is one of the most important parameters in gas-liquid two-phase flow, which plays a crucial role in the pressure gradient calculation and the flow pattern analysis. In this paper, a new coaxial line phase sensor based on the electromagnetic wave propagation is designed and phase shift principle is proposed for the void fraction measurement, and the function relationship between the void fraction and phase difference is derived. By the theoretical analysis and 56 static calibration experiments, the measurement model is proposed in this paper. Air-water two-phase flow experiments have been conducted in a vertical tube at 48 flow conditions in a stainless-steel tubular test section which has an inside diameter of 50.0mm. The dimensionless quantities related to the void fraction, e.g. dynamic viscosity ratio, gas-liquid density ratio, gas-phase Froud number (Frg) and Lockhart-Martinelli parameter (${\mathrm {X}}_{{\mathrm {LM}}}$), are dimensional analyzed. According to the $\Pi $ theorem, a new void fraction correlation which could acceptably handle all the available data of different flow conditions (authors’ and literature) is proposed. Laboratory results indicate that the mean absolute error (MAE) of the correlation is 6.46% within an error band of ±10% and 8.03% (183 literature data points) within an error band of ±15%. The void fraction correlation has good prediction accuracy and a certain extrapolation for different flow regimes and fluid characteristic parameters. [ABSTRACT FROM AUTHOR]

This paper aims to obtain a relation for estimating the median size of bed sediment, d 50 , at the bends of meandering rivers based on real data. To achieve such a purpose, field data, including topographic, sediment sampling, and flow measurements, were collected from various rivers in Iran at different times of the year. Then, the Buckingham Π-theorem was applied to identify the effective dimensionless numbers such as the Shields function, Reynolds particle number, Froude number, submerged specific gravity of sediment, and aspect and curvature ratios. A correlation analysis was conducted between such factors to eliminate those dependent on others. In the following, three regression techniques, containing the power function approach, the general additive model (GAM), and the multivariate adaptive regression spline (MARS), were chosen to achieve the best relation. The obtained results indicated that the developed MARS model produced a better result than the others and was much more satisfactory, with a coefficient of determination (R2) of 0.96 and 0.95 and root-mean-square error (RMSE) of 140.64 and 140.47 for the training and testing phases, respectively. Furthermore, the MARS outputs were validated with an analytical method, which showed that MARS fitted with the field data much better. Consequently, the distinguished merit of this study is the development of a relation for determining d 50 that shows which geometric and hydraulic parameters have the most effect on sediment size in the river bend. [ABSTRACT FROM AUTHOR]

Urban flooding is a problem faced by most countries because of climate change. Without storm drainage systems, negative impacts may occur, such as traffic problems and increasing groundwater levels, especially in lowlands. The implementation of storm drainage networks and their fittings in poor countries is affecting their economic development. Therefore, improving the efficiency of the storm drainage network is an important issue that should be considered. This paper aims to study the most appropriate position or arrangements of grate inlets to upgrade drainage efficiency at less cost. Different arrangements of grates were studied and their efficiency was determined. A comparison between the total grate's efficiency was conducted and the best arrangement was selected. Additionally, a dimensional analysis equation was developed to determine the total efficiency of the system. Finally, the FLOW-3D program was used to simulate the laboratory results using different discharges and numbers of inlets. The error of calculation ranged between 5% and 8%. Therefore, the results indicated that this program is a powerful tool for predicting the discharge efficiency and velocity direction for large discharges. A comparison was made between this study and previous studies. The results indicated that the same trend existed. A new equation was developed to correlate discharge efficiency (E) with relative total discharge Q and number of inlets. The equation can be used by planning engineers to conduct initial planning of storm drainage layout systems and achieve cost saving. [ABSTRACT FROM AUTHOR]

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In this paper, the AUTODYN/Smoothed Particle Hydrodynamics (SPH) method was used to study the impact of reactive fragments on three-layer equidistant steel plates. The perforation characteristics of equidistant three-layer steel plates were investigated along with the parameters of combustion energy release from reactive fragments under varied impact velocities and shape conditions. The modification of the steel plates' perforation diameter was investigated using the dimensional analysis approach. The shock wave pressure and chemical reaction characteristics were examined using the shock wave theory. The results show that within the examined impact velocity range, the perforation diameter initially increased and then decreased as the impact velocity of the reactive fragment rose. In addition, the perforation diameter was approximately 1.5–3 times the diameter of the reactive fragment. As the impact speed increased, the active reaction generated by the reactive fragments became more sufficient. The energy released contributed to the impact's pressure rise; in addition, the temperature of the steel plate was raised in part by the reactive fragment impact, making the steel plate more prone to melting. The results of this investigation provide important support for a detailed understanding of the rules governing the failure of steel plates under the impact of reactive fragments as well as the combustion of reactive fragments under impact. [ABSTRACT FROM AUTHOR]

Bridges are structures subjected to multiple types of loads and combinations during their service life. The uncertainties linked with the materials' behavior and manufacturing processes often necessitate the testing of produced elements on a real scale. This is particularly true for bridge concrete precast girders, which are frequently tested to predict the ultimate carrying load. Testing procedures are time-consuming, expensive in terms of both time and money, and involve a large amount of logistics and auxiliary equipment and devices. Thus, testing scaled-down models in laboratory conditions and extrapolating the obtained results with respect to the real-scale element using similitude theory has become a very common alternative method in the last decade. In this paper, experimental data regarding the efficiency of dimensional analysis computation are discussed. The proposed method involves comparing the values at which failure in bending and shear occurs for a 1:10 cementitious concrete bridge beam model with respect to the values computed for the prototype beam. Regarding the obtained results, a very small difference between the test results and the calculated values can be noticed. [ABSTRACT FROM AUTHOR]

The study focuses on the critical concern of designing secure and resilient bridge piers, especially regarding scour phenomena. Traditional equations for estimating scour depth are limited, often leading to inaccuracies. To address these shortcomings, modern data-driven models (DDMs) have emerged. This research conducts a comprehensive comparison involving DDMs, including support vector machine (SVM), gene expression programming (GEP), multilayer perceptron (MLP), gradient boosting trees (GBT) and multivariate adaptive regression spline (MARS) models, against two regression equations for predicting scour depth around cylindrical bridge piers. Evaluation employs statistical indices, such as root-mean-square error (RMSE), coefficient of determination (R2), mean average error (MAE) and normalized discrepancy ratio (S(DDRmax)), to assess their predictive performance. A total of 455 datasets from previous research papers are employed for assessment. Dimensionless parameters Froude number F r = U gy , Pier Froude number F r P = U g ′ D , and the ratio of scour depth to pier diameter (y D) are carefully selected as influential model inputs through dimensional analysis and the gamma test. The results highlight the superior performance of the SVM model. In the training phase, it exhibits an RMSE of 0.1009, MAE of 0.0726, R2 of 0.9401, and SDDR of 2.9237. During testing, the SVM model shows an RMSE of 0.023, MAE of 0.017, R2 of 0.984, and SDDR of 5.301. Additionally, it has an average error of − 0.065 and a total error of − 20.642 in the training set and an average error of − 0.005 and a total error of − 0.707 in the testing set. Conversely, the M5 model exhibits the lowest accuracy. The statistical metrics unequivocally establish the SVM model as significantly outperforming the experimental models, placing it in a higher echelon of predictive accuracy. [ABSTRACT FROM AUTHOR]

This paper studied the energy absorption performance of conical tubes subjected to dynamic axial loading based on numerical finite element calculations. The influence of geometric parameters and material properties on the collapse behavior and energy absorption was discussed. The results showed that the two materials considered in this study have little effect on deformation mode of conical tubes, while the taper angle has a significant effect on deformation mode of conical tubes, and a classification chart of deformation modes for conical tubes was proposed. It was found that the conical tubes with TM mode have the best energy absorption characteristics, and the aluminum alloy conical tubes is more effective than similar tubes made from mild steel. Based on dimensional analysis, a model was proposed to predict the dynamic response of conical tubes under axial loading, including deformation displacement, energy absorption, specific energy absorption and mean crushing force. The results predicted by the proposed model were found to match well with the finite element analysis results. Furthermore, the equivalent substitution method between the aluminum alloy and mild steel conical tubes was studied, which concluded that the energy absorption equivalence method is better for lightweight design of energy-absorbing conical tubes. [ABSTRACT FROM AUTHOR]

The deduction of the weir flow stage-discharge relationship is a hydraulic problem generally solved by energy considerations and using the discharge coefficient to correct the gap between theoretical results and experimental measurements. In this context, the dimensional analysis represents an alternative to find simple and reliable equations to obtain the rating curve. In this study, the outflow process of vegetated weirs is investigated applying the Π-Theorem of dimensional analysis and the incomplete self-similarity theory. The aim of this paper is to propose a new theoretically-based stage-discharge relationship, and test its applicability by measurements recently published in the literature. The results showed that the errors in discharge estimate obtained by the proposed stage-discharge relationship are always less than or equal to ± 10% and less than or equal to ± 5% for 97–100% of cases. The main advantage of the proposed relationships is providing a single stage-discharge relationship, which has better performances than the equations reported in the literature and excludes the use of discharge coefficient. [ABSTRACT FROM AUTHOR]

Due to the size limitations of shaking tables, dynamic scale models of large-span space structures for engineering have small cross-sections and thin wall thicknesses. It is difficult to use the structural steels commonly used in prototypes to make dynamic scale models. In this paper, 304 stainless steel is proposed for making the scale model, and the similarity relationship between the structural-steel prototype and the 304-stainless-steel dynamic scale model was studied. Firstly, a uniaxial test was conducted to study the elastic modulus similarity and the yielding stress similarity. The test results demonstrated that the elastic modulus similarity ratio was 1:1, and the stress similarity ratios of the 304 stainless steel and the three typical structural steels were 1:1 (Q235 steel), 1:1.5 (Q355 steel) and 1:1.8 (Q420 steel). Then, the similarities of other variables were derived using the dimensional analysis method. In the end, a numerical analysis was conducted to verify the similarity relationship between the structural-steel prototype and the 304-stainless-steel dynamic scale model. In the numerical analysis, a single-layer spherical reticulated shell structure and a dynamic scale model with a length similarity ratio of 1:20 were established by using the ABAQUS 2021 software, and the node displacement, the element internal force and natural vibration characteristics were analyzed. The results show that standard deviations of the displacements, the internal forces and the natural vibration frequencies between the prototype and the scale model were within 5%. It turns out that the proposed similarity between the structural-steel prototype and the 304-stainless-steel dynamic scale model was applicable in the elastic stage. The findings provide a reference for designing a dynamic scale model of large-span space structures for engineering by using 304 stainless steel. [ABSTRACT FROM AUTHOR]

The study carried out aims to determine the way in which the heat transfer occurs from the front part of the orifice of the extrusion nozzle of the thermoplastic material to the component elements of such an assembly. The paper considers the study in the introductory part of the current situation in the specialized literature. The second part is affected by the analysis of their geometric and dimensional structure and the way of their realization and their interconnection. Further, in the analysis, the way in which the discretization of the process of calculating the temperature values is carried out in the simulation program was considered, and last but not least, the way of its evolution. Based on the graphic simulation for the extrusion temperatures considering poly lactic acid (PLA) and respectively acrylonitrile butadiene styrene (ABS) it was possible to highlight that the area where the extruded material in the part of the structure modification has an increasing temperature trend towards the upper part of cooling it. [ABSTRACT FROM AUTHOR]

Soil swelling in road layer is the complex phenomenon. The paper aims to derive a concise expression for two challenging design parameters when the subgrade layer is expansive in geotextile-reinforced unpaved road. The design parameters considered in the present study are the mobilized bearing capacity and swelling pressure for expansive soil. Herein the dimensional analysis via Buckingham's π method is applied to derive the design parameters by forming the dimensionless group for prototype and model system. The model testing for the swelling pressure and mobilized bearing capacity are carried out in the laboratory by using consolidometer ring and CBR set up. The test results reveal the swelling pressure of 22.03kN/m2 for the soil sample having 76% as degree of saturation. A linear relation is observed between swelling pressure and degree of saturation and becomes equal upon surcharge. The mobilized bearing capacity for the expansive soil sample is 0.47kg/cm2. The failure pattern observed during testing is general shear failure in unsoaked condition and punching soil failure in soaked condition. The paper provides geometric ratio of 1:6 for model and prototype and also suggests modification in Giroud and Han generic equation by including the developed dimensionless group. [ABSTRACT FROM AUTHOR]

Acoustic Emission (AE) is a non-destructive evaluation method that uses transient elastic waves produced by the sudden release of mechanical energy in a material or structure. This method generates multiple AE events during testing; therefore, it is important to develop parameters that capture the characteristics of each event (AE hit). The paper introduces new dimensionless parameters to characterize the waveform of AE signals: Earliness, Transitoriness, and Early Transitoriness. The study shows that these parameters provide an accurate description of AE waveforms, in some respects, better than traditional parameters, which makes them suitable for filtering with simple rules or in combination with machine-learning techniques. Two examples of the application of AE hit filtering from sedimentation and soil compression experiments are provided. In the sedimentation test analysis, the proposed parameters were used with K-means clustering to filter AE hits from outside the zone of interest and to calculate the rate of sedimentation. In the compression test of a sand sample under oedometric conditions, a simple filtering rule was applied to discriminate AE hits from unwanted sources and obtain a clear AE energy cumulative curve. In both cases, the dimensionless parameters have shown the capacity to discriminate between different AE sources and paths and the possibility of filtering hits from unwanted sources. [ABSTRACT FROM AUTHOR]