Foundation Material Research Articles

New 3D Printed Scaffolds Based on Walstromite Synthesized by Sol-Gel Method.

This study explores the potential utilization of walstromite (BaCa2Si3O9) as a foundational material for creating new bioceramics in the form of scaffolds through 3D printing technology. To achieve this objective, this study investigates the chemical-mineralogical, morphological, and structural characteristics, as well as the biological properties, of walstromite-based bioceramics. The precursor mixture for walstromite synthesis is prepared through the sol-gel method, utilizing pure reagents. The resulting dried gelatinous precipitate is analyzed through complex thermal analysis, leading to the determination of the optimal calcination temperature. Subsequently, the calcined powder is characterized via X-ray diffraction and scanning electron microscopy, indicating the presence of calcium and barium silicates, as well as monocalcium silicate. This powder is then employed in additive 3D printing, resulting in ceramic scaffolds. The specific ceramic properties of the scaffold, such as apparent density, absorption, open porosity, and compressive strength, are assessed and fall within practical use limits. X-ray diffraction analysis confirms the formation of walstromite as a single phase in the ceramic scaffold. In vitro studies involving immersion in simulated body fluid (SBF) for 7 and 14 days, as well as contact with osteoblast-like cells, reveal the scaffold's ability to form a phosphate layer on its surface and its biocompatibility. This study concludes that the walstromite-based ceramic scaffold exhibits promising characteristics for potential applications in bone regeneration and tissue engineering.

Semi-Analytical Approach and Green's Function Method: A Comparison in the Analysis of the Interaction of a Moving Mass on an Infinite Beam on a Three-Layer Viscoelastic Foundation at the Stability Limit-The Effect of Damping of Foundation Materials.

In this paper, the interaction of a mass moving uniformly on an infinite beam on a three-layer viscoelastic foundation is analyzed with the objective of determining the lowest velocity at the stability limit, called, in this context, the critical velocity. This issue is important for rail transport and, in particular, for the high-speed train, because the moving mass is the basic model of a vehicle, and the infinite beam on a three-layer viscoelastic foundation is the usual mechanical representation of the railway track. In addition to this, the advantages and disadvantages of the two implemented methods, namely, the semi-analytical approach and the Green's function method, are summarized in terms of computational time, the precision of the obtained results, limitations, and the feasibility of implementation. All results are presented in a dimensionless form to cover a wide range of possible scenarios. Some results may be considered academic, however, results related to a particular railway track are also included. Particular attention is paid to the influence of the damping of materials in the foundation upon the critical velocity of the moving mass. Regarding the semi-analytical approach, it is demonstrated that the critical velocities can be obtained in an exact manner by tracing the branches of the so-called instability lines in the velocity-moving-mass plane. This analysis can be maintained within the real domain. As for the time series, they can be determined by a numerical inverse Laplace transform. Moreover, thanks to the analytical form of the final result in the Fourier domain, each value corresponding to a specific time instant can be obtained directly, that is, without the previous time history. Regarding the Green's function method, this is used to verify a few points delimiting the stable and unstable regions of the moving mass with the help of the D-decomposition approach. Additionally, a numerical algorithm based on the Green's function and convolution integral written for dimensionless quantities is used to calculate the time series of the moving mass. In addition to identifying the critical velocity of the moving mass, its connection with the critical velocity of the moving force is emphasized, and the possibility of validating the results on long finite beams using modal expansion is presented and described.

Highly oriented BN-based TIMs with high through-plane thermal conductivity and low compression modulus.

In the pursuit of effective thermal management for electronic devices, it is crucial to develop insulation thermal interface materials (TIMs) that exhibit exceptional through-plane thermal conductivity, low thermal resistance, and minimal compression modulus. Boron nitride (BN), given its outstanding thermal conduction and insulation properties, has garnered significant attention as a potential material for this purpose. However, previously reported BN-based composites have consistently demonstrated through-plane thermal conductivity below 10 W m-1 K-1 and high compression modulus, whilst also presenting challenges in terms of mass production. In this study, low molecular weight polydimethylsiloxane (PDMS) and large-size BN were utilized as the foundational materials. Utilizing a rolling-curing integrated apparatus, we successfully accomplished the continuous preparation of large-sized, high-adhesion BN films. Subsequent implementation of stacking, cold pressing, and vertical cutting techniques enabled the attainment of a remarkable BN-based TIM, characterized by an unprecedented through-plane thermal conductivity of up to 12.11 W m-1 K-1, remarkably low compression modulus (55 kPa), and total effective thermal resistance (0.16 °C in2 W-1, 50 Psi). During the TIMs performance evaluation, our TIMs demonstrated superior heat dissipation capabilities compared with commercial TIMs. At a heating power density of 40 W cm-2, the steady-state temperature of the ceramic heating element was found to be 7 °C lower than that of the commercial TIMs. This pioneering feat not only contributes valuable technical insights for the development of high-performance insulating TIMs but also establishes a solid foundation for widespread implementation in thermal management applications across a range of electronic devices.

Effect of soil-foundation interaction on the modulus of subgrade reaction

For design of raft foundations, the soil is commonly modelled by using elastic springs, which is based on the Winkler’s theory. In the static analyses, these springs are considered as a constant value k called the modulus of subgrade reaction. However, no foundation is infinitely flexible due to the interaction between the soil and foundation, which is investigated in the present work. For this purpose, the effect of foundation dimensions and foundation material on the subgrade reaction modulus is examined for square-shaped foundations with uniformly distributed load, and the results obtained from these analyses are compared with those in infinitely flexible foundations. It is shown that the effect of Young’s modulus of foundation material on the k-value can be ignored while the foundation dimensions have a great effect on the k-value. The ratio of the subgrade reaction modulus obtained from the analyses taking into account the soil-foundation interaction to the subgrade reaction modulus in infinitely flexible cases varies between 0.36 and 0.45 in the middle area of foundations as well as 0.45 and 0.76 on the edges of foundations with a width between 5 m and 20 m as well as a thickness between 0.25 m and 1.0 m.

Review on Sisal and E Glass Fiber Composites for Roof Tiles

Composite materials have emerged as a pivotal technology in mechanical and civil engineering, with matrix and reinforcement serving as fundamental components. This dynamic interplay involves one element as the foundational material and the other as an augmenting agent, unified through epoxy resin as a bonding agent. This study focuses on a comprehensive review of hybrid composites, specifically employing sisal and E Glass fiber, for roofing tile applications. Rigorous examination of various articles from diverse journals informs the material characterization process, involving meticulous sample preparation and testing. Beyond sisal and E Glass composites, the literature also explores substitute materials, broadening the scope of potential applications. Emphasizing environmental consciousness, this research aligns with the green materials paradigm, presenting eco-friendly and sustainable solutions within the prevailing environmental context. By delving into alternative composites and their potential benefits, this work contributes to the ongoing discourse on advancing materials science for environmentally responsible applications in the fields of mechanical and civil engineering.

A lag bloom pattern of phytoplankton after freshwater input events revealed by daily samples during summer in Qinhuangdao coastal water, China.

Phytoplankton blooms have become a global concern due to their negative impacts on public health, aquaculture, tourism, and the economic stability of coastal regions. Therefore, elucidating the shifts in phytoplankton community structure and abundance, as well as their environmental drivers, is crucial. However, existing studies often fail to capture the detailed dynamics of phytoplankton blooms and their environmental triggers due to low temporal observation resolution. In this study, high temporal resolution (daily) samples were collected over 43 days to investigate the influence of environmental factors on phytoplankton in Qinhuangdao in the summer. During the observation period, a total of 45 phytoplankton species were identified, comprising 26 Bacillariophyta species, 16 Dinophyta species, 2 Euglenophyta species, and 1 Chromophyta species. Interestingly, a lag bloom pattern of phytoplankton behind freshwater input was observed across day-to-day samples. Phytoplankton blooms typically lagged 1-3 days behind periods of decreased salinity and nutrient input, suggesting that freshwater influx provides the foundational materials and benefits for these blooms. Moreover, the phytoplankton blooms were triggered by six dominant species, i.e., Chaetoceros spp., Pseudo-nitzschia delicatissima, Skeletonema costatum, Protoperdinium spp., Leptocylindrus minimus, Pseudo-nitzschia pungens, and Thalassiosira spp. Consequently, the succession of phytoplankton showed a predominant genera shift in the following sequence: Nitzschia, Protoperdinium, and Prorocentrum - Skeletonema - Pseudo-nitzschia - Gymnodinium - Leptocylindrus. Besides that, a deterministic process dominated phytoplankton community assembly across time series, and DIP is a key factor in shifting the phytoplankton community structures in this area. In summary, our study offers high-resolution observations on the succession of phytoplankton communities and sheds light on the complex and differentiated responses of phytoplankton to environmental factors. These findings enhance our understanding of the dynamics of phytoplankton blooms and their environmental drivers, which is essential for the effective management and mitigation of their adverse impacts.

Reproducibility in materials informatics: lessons from ‘A general-purpose machine learning framework for predicting properties of inorganic materials’

Reproducing results from a foundational materials informatics tool (magpie) is difficult and in this study, a failure. This failure yields tangible suggestions to promote easy adoption and trust of materials informatics in the future.

Use of high-performance reinforcement geosynthetics to stabilize access roads

With the rapid infrastructure development, the availability of competent soils is decreasing. The access roads and tracks practicability should be ensured when crossing these weak soils. The practicability of access roads and tracks is therefore important. Depending on the mechanical properties of the subgrade, the construction of access roads requires the use of granular foundation materials of significant thickness, which can result in substantial costs and construction delays. This is especially true when the runway is to be constructed on soft subgrade and possibly in the presence of water. This article presents the use of a high-performance reinforcement geosynthetic to stabilize unpaved access roads, control settlement and prevent contamination between the subgrade and the foundation. A laboratory case well documented is used. Two calculation methodologies based on the subgrade soil characteristics are provided and compared.

발달장애성인 평생교육 프로그램 운영의 어려움 탐색

This study aimed to identify key issues in the development direction of lifelong education (vocational education) programs for adults with developmental disabilities by conducting language network analysis of expert and stakeholder interview data. Interviews were conducted with five experts and stakeholders to gather information on the challenges faced in implementing lifelong education(vocational education) programs for individuals with developmental disabilities and the necessary aspects to consider in establishing development directions. The collected data underwent language network analysis using Textom and UCINET, including frequency analysis, centrality, TF-IDF, and CONCOR. The findings of this study could serve as foundational material in seeking integrated and systematic support approaches at both national and community levels, aimed at sustaining the lives of individuals with developmental disabilities.

건강한 노화를 위한 스마트 패키징 디자인 연구 동향 분석

With the advent of an ultra-aging society, there is a trend among the elderly to emphasize accessibility to product safety and nutritional information through smart packaging technology. Consequently, research in design related to this aspect has become increasingly important. This study aims to contribute to the direction of design research for the healthy aging of the elderly through an analysis of trends in smart packaging design research. Firstly, a systematic literature review was conducted, collecting and filtering textual data such as titles, keywords, abstracts, and publication years of documents selected with the search terms 'food' AND 'packaging design' OR 'elderly' OR ‘Aging Population’ from 2000 to 2023. Secondly, analysis results were derived through meta-analysis and text mining. Thirdly, conclusions and implications were proposed based on the analyzed results. The comprehensive findings of this study indicate that nanotechnology-based food packaging design is a key research area and keyword, serving as foundational material for shaping the themes and directions of smart packaging design.

1834년 신빈민법의 이데올로기적 양면성과 그 실제

This paper seeks to trace the ideological trends surrounding the enactment of the New Poor Law and explore the essence of the act itself and the changes it brought about. The Swing Riots of 1830 sparked a substantial demand for reforming poor laws, resulting in the organisation of the Royal Commission into the Operation of the Poor Laws. Edwin Chadwick, a Benthamite, and Nassau Senior, a liberal political economist, played key roles in leading the compilation of the final report of the commission that served as the foundational material for the New Poor Law. Their divergent ideological orientations translated into the dual nature of the act. Utilitarian Benthamites prioritised expanding government functions, the growth of bureaucracy, and the restructuring and rationalisation of administrative structures as needed. On the other hand, advocates of classical liberalism, who championed laissez-faire, emphasized minimizing government intervention, local autonomy, and economic individualism. The specific legal provisions of the New Poor Law and the socio-economic changes following its enactment were an exquisite compromise between these two ideologies. According to the act, a central authority specialising in poor administration was established. Locally, the parish-based Old Poor Law system was dismantled, and poor law unions took the place of parishes, establishing large joint workhouses. These structural changes clearly aligned with the direction pursued by the Benthamites. At the same time, in specific matters, the New Poor Law, however, embodied elements of classical liberalism. The newly established central authority performed only a passive supervisory role, and the operation of local unions still remained under the influence of local elites. The ultimate goal of the union workhouses was not the expected rehabilitation of or care for the poor but rather a deterrent effect. In conclusion, the 19th-century New Poor Law system encapsulated elements of classical liberalism within the Benthamite framework.

영유아교사의 놀이중심 과학교육에 대한 인식과 어려움

This research aims to analyze the perceptions and challenges faced by early childhood teachers regarding play-based science education and seeks to explore implications and strategies for enhancing science education. To achieve these goals, the study conducted a collaborative learning community with 11 teachers (5 for toddlers and 6 for kindergartners) working in 4 childcare centers in A City. The researchers collected scientific activity videos, educational materials, childcare records, teachers’ journals, and other data from the participating teachers. Using a thematic coding analysis method, the study categorized the perceptions of early childhood teachers regarding science education into three main themes: 'Understanding play-based science education,' 'Science education with the goal of knowledge transmission,' and 'Challenges and difficulties in science education.' Furthermore, in the field of early childhood education, teachers were found to recognize difficulties in implementing play-based science education. These difficulties included challenges related to "Finding and supporting science within play," "Psychological and physical challenges faced by teachers," and "Challenges with principals, other teachers, and parents." The significance of this study lies in its potential to serve as foundational material for understanding teachers' perceptions of science education and addressing the challenges they face in teaching science.

Removal of heavy metals from wastewater by aerogel derived from date palm waste

Cellulose that has been sourced from date palm leaves as a primary component was utilised. This cellulose served as the foundational material for the development of an aerogel composite. During this process, MXene (Ti3C2Tx) played a pivotal role in enhancing the overall composition of the aerogel. To ensure the stability and durability of the resulting aerogel structure, calcium ions were introduced to the mix. These ions facilitated the cross-linking process of sodium alginate molecules, ultimately leading to the formation of calcium alginate. This cross-linking step is crucial for the enhanced mechanical and chemical stability of the aerogel. Incorporating alginate and Ti3C2Tx into the cellulose aerogel enhanced its structural integrity in aqueous conditions and increased its adsorption capacity. When evaluated with synthetic wastewater, this composite exhibited remarkable adsorption capacities of 72.9, 114.4, 92.9, and 123.9 mg/g for As, Cd, Ni, and Zn ions, respectively. A systematic study was carried out to see the effect of various parameters, including contact time, MXene concentration, pH, and temperature on the adsorption of these elements. Peak adsorption was achieved at 60 min, favoring a pH range between 6 and 8 and exhibited optimal sorption efficiency at lower temperatures. The adsorption kinetics adhered closely to a pseudo-second-order, while the Freundlich model adeptly described the adsorption isotherms. An interesting result of this research was the aerogel's regenerative potential. After undergoing a basic acid treatment, the MXene/cellulose/alginate aerogel composite could be restored and reused for up to three cycles, all while maintaining its core performance capabilities even after the rigorous cross-linking processes. In three consecutive cycles, the removal percentages for As, Cd, Ni, and Zn were 48.15%, 80.38%, 56.51%, and 86.12% in cycle 1; 37.35%, 65.63%, 45.97%, and 78.42% in cycle 2; and 28.60%, 56.22%, 34.70%, and 65.83% in cycle 3, respectively. The composite was tested in conditions resembling seawater salinity. Impressively, the aerogel continued to demonstrate a significant ability to adsorb metals, reinforcing its potential utility in real-world aquatic scenarios. These findings suggest that the composite aerogel, integrating MXene, cellulose, and alginate, is an effective medium for the targeted removal of heavy metals from aquatic environments.

Mixed Ionic Electronic Conduction Caused by Phase Transformation and Interfacial Segregation in an Entropy Stabilized Oxide

Research on entropy-stabilized oxides (ESO) [1] has primarily focused on exploring new single-phase structures with diverse chemistries, or unique properties, such as high Li-ion conductivity, high dielectric constant, low thermal conductivity, good electrochemical cycling stability, and high storage capacity retention [2]. However, few studies discuss the impact of secondary phase formation on functionality such as electrical conductivity [3] despite the fact that annealing this single-phase ESO causes it to undergo a phase transformation leading to the formation of Cu-rich and Co-rich secondary phases [4]. To address this gap, this work [5] investigates the electrical transport mechanisms in the canonical entropy-stabilized oxide (Co,Cu,Mg,Ni,Zn)O as a function of secondary phase content. Here, the structure and composition of single-phase and multiphase ESOs, and their GBs and HIs are probed using atomic-resolution imaging by scanning transmission electron microscopy (STEM) coupled with nanoscale spectroscopy by electron energy-dispersive spectroscopy (EDS) and electron energy-loss spectroscopy (EELS). Our findings suggest that when single-phase, the oxide is an oxygen ion conductor. After 2 h of heat treatment, Cu-rich tenorite particles form at some grain boundaries, turning the grain interior rocksalt oxide into a mixed ionic-electronic conductor via oxygen ions and small hole polaron Co2+/Co3+ and Cu2+/Cu+ pairs. 24 h of heat treatment leads to the full coverage of Cu-rich tenorite particles at all grain boundaries and the formation of anisotropic Cu-rich tenorite and equiaxed Co-rich spinel particles in the grains. While the grain interiors exhibit similar mixed ionic-electronic conduction, Cu-rich tenorite grain boundary phases create a pathway for Cu2+/Cu3+ small hole polarons. The ability to selectively grow secondary phases nucleated at grain boundaries enables tuning of electrical properties in entropy-stabilized and complex concentrated oxides using microstructure design, nanoscale engineering, and heat treatment, paving the way to develop many novel materials.[1] C. M. Rost, J.-P. Maria, Nat Commun, 2015.[2] A. Salian, S. Mandal, Critical Reviews in Solid State and Materials Sciences, 2022.[3] M. Moździerz, K. Świerczek, Acta Materialia, 2021.[4] A. D. Dupuy, J. M. Schoenung, Journal of the European Ceramic Society, 2021.[5] H. Vahidi...W. J. Bowman (submitted). Acknowledgments This research was primarily supported by the National Science Foundation Materials Research Science and Engineering Center program through the UC Irvine Center for Complex and Active Materials (DMR-2011967). WJB and HV acknowledge partial support from the UCI new faculty startup funding. The authors acknowledge the use of facilities and instrumentation at the UC Irvine Materials Research Institute (IMRI) supported in part by the National Science Foundation Materials Research Science and Engineering Center program through the UC Irvine Center for Complex and Active Materials (DMR-2011967).

Development of Novel Coating on Metallic Bipolar Plates for Proton Exchange Membrane Water Electrolyzer Application

Considering the demand for a more environmentally friendly system, renewable and sustainable energy sources, such as wind and solar power are regarded as a promising substitute for fossil fuels in the generation of electricity. Since these energy sources exhibit intermittency and unpredictability, there is a need to develop a highly efficient and rapidly responsive energy conversion system for the purpose of storing this energy as a chemical fuel. Due to their ability to manage the variability of intermittent energy sources, proton exchange membrane electrolyzer cells (PEMECs) are garnering considerable interest. However, their broad commercial adoption is hindered by their relatively modest performance and elevated costs. PEM electrolysis is a promising technology for generating substantial quantities of hydrogen from surplus electricity generated by renewable sources. Nonetheless, the expense of the electrolyzer stack arises primarily from the metallic bipolar plates, because it possesses heavy weight and expensive precious metal coatings. Significant efforts have been performed on the development of titanium-based bipolar plates, but it has high base material and fabrication cost. In recent years, there has been a substantial focus on stainless steel bipolar plates for PEM electrolyzer application. Stainless steel can serve as an alternative, but it requires a coating to enhance its anti-corrosion properties. Electroplated chromium coatings exhibit favorable mechanical characteristics and find extensive application in precision mechanical components such as molds and surgical instruments. Their outstanding wear resistance, high hardness, impressive corrosion resistance, and glossy finish make them appropriate for many other applications, including both decorative and functional coatings. As a result, chromium electroplating has emerged as one of the most extensively employed techniques within the electroplating sector. The dense pack chromium layer is prepared on a 316L stainless steel substrate to enhance the anti-corrosion property and electronic conductivity.Herein, the role of gold striking underlayer, and thick chromium coating is studied for preparing the anti-corrosive stainless steel bipolar plates. First, a gold striking film as an underlayer on the stainless-steel substrate is electroplated to passivate the chromium-based oxides. Further, a thick and dense chromium layer is deposited on the gold underlayer by electroplating. The electroplating bath is operated using platinized titanium felt as an anode and 316L stainless steel as a working electrode without the separation of anodic and cathodic compartments. The electroplating solution is consisting of Cr (VI) oxide and H2SO4 (pH = 2). The nanocrystalline chromium coating with a thickness of approximately 2 µm is bright and uniform. Furthermore, gold as a protective layer of thickness approximately 1 µm is coated by electroplating on the chromium surface. The Cr and Au/Cr coatings are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron microscopy (XPS) analysis. Subsequently, the protective layer-coated substrates were analyzed in a simulated PEM electrolyzer environment, and these coatings facilitated promising protective properties on the stainless-steel substrate. The corrosion testing was carried out in 0.5 M H2SO4 + 2 ppm HF solution at 70 0C purged with oxygen. The stable passive film and high corrosion resistance were obtained by gold striking underlayer and chromizing the 316L stainless steel substrate. As a result, the potentiodynamic polarization analysis showed the corrosion current density of 0.84 µA/cm2 for the Au/Cr-Au underlayer sample in a simulated operating environment. In contrast, the absence of the gold striking underlayer between Cr and stainless steel causes the pitting corrosion. The Au/Cr coating is tested in an acidic corrosion media for a long duration of 24 hours and it showed lower degradation as compared to without gold striking underlayer and without Cr film. The findings presented in this study illustrate the feasibility of employing stainless steel as the foundational material for the bipolar plate of a PEM electrolyzer.

Which Interfaces Matter Most? Variability in Grain Boundary Defect Chemistry and Conductivity in a Concentrated Solid Electrolyte

Inorganic solid electrolytes with fast ionic conductivity are critical components of fuel/electrolysis cells, all-solid-state batteries, membrane and separation reactors, sensors and other electrochemical devices. For example, solid oxygen ion (O2-) conductors are used in solid oxide fuel/electrolysis cells (SOFCs/SOECs) for high-efficiency conversion between chemical and electrical energy and chemical production from CO2. One major challenge in engineering such materials is the diminished grain boundary (GB) conductivity in polycrystalline oxide ceramics. This phenomenon, which was initially accredited to highly resistive silica-based glassy impurity phases, is attributed to the formation of intrinsic space charge layers (SCLs) directly adjacent to GB cores. The positive potential at the GB core (due to large concentrations of oxygen vacancies) results in a depletion of oxygen vacancies in the space charge layer as well as the segregation of charge-compensating acceptor solutes from grain interiors which ultimately reduces GB conductivity. Several strategies have been explored to improve GB conductivity by understanding and mitigating the SCL effects. While the standard Poisson–Boltzmann approach models the near-grain boundary defect behavior in dilute solid solutions and recent models by Mebane et al [1] and Virkant et al [2] incorporate the effects of defect-defect interactions (in concentrated solid solutions) and chemomechanical stress, respectively, there is yet to be a model developed that can predict individual GB conductivities in concentrated solid solutions based on direct experimental measurements of near-GB defect chemistry.Here, we present an experimental-computational framework that predicts which GBs in a polycrystalline electrolyte likely facilitate ionic conductivity. We developed a thermodynamic phase-field modeling framework and applied it to a model oxygen electrolyte Gd0.25Ce0.75O2-δ, wherein the GB-to-GB variability in defect concentrations (Gd3+ solutes, electrons localized at Ce3+, and oxygen vacancies) was measured microscopically using scanning transmission electron microscopy electron energy-loss spectroscopy (STEM EELS). These data were used to predict the GB-to-GB variability in cross-GB ionic conduction using a unique model, which prioritizes reproducing microscopically observed GB defect concentrations and considers defect-defect interactions in highly concentrated solid solutions, making the framework applicable to other technologically relevant solid electrolytes. Across the GBs studied, we revealed a non-monotonic relationship between depletion and GB conductivity, with the highest conductivity predicted for intermediate depletion amounts. This work lays the foundation for future experimental-computational research and advanced data-driven design of solid electrolytes needed for functional and energy storage/conversion devices.[1] D. S. Mebane, R. A. D. Souza, Energy & Environmental Science, 2015.[2] K. S. N. Vikrant, R. Edwin García, Energy & Environmental Science, 2018.[3] H. Vahidi, W.J. Bowman (Submitted). Acknowledgments HV and WJB acknowledge primary support from the UCI new faculty startup funding. This research was partially supported by the National Science Foundation Materials Research Science and Engineering Center program through the UC Irvine Center for Complex and Active Materials (DMR-2011967). We acknowledge the use of facilities and instrumentation at the UC Irvine Materials Research Institute (IMRI) supported in part by the same NSF MRSEC (DMR-2011967). AM, DM, and AC acknowledge funding from the NSF [WB1] [hv2] and the WVU MAE research department for the use of the Thorny Flat HPC Cluster for the numerical modeling work and computational resources.

Frost soil interaction with the cement-sand mortar of a driven precast pile

Introduction. The drilling method of pile driving represents the most common method of constructing foundations on permafrost soils. In order to reduce the tangential forces of frost heaving, the space between the pile surface and a leader well wall within the layer of seasonal freezing-thawing is filled with non-heaving sandy soil. This technology complicates the process of installing driven precast piles. In this case, a significant simplification involves filling the space between the pile and the soil with a cement-sand mortar (CSM) along the entire height of the pile. However, at present, no method is valid for calculating driven precast piles for the action of frost heaving tangential forces during CSM freezing.Aim. To develop a methodology for calculating driven precast piles for the action of frost heaving tangential forces during CSM freezing.Materials and methods. A set of laboratory tests, modeling the processes in soils during cold and warm pile installation periods, was carried out. Laboratory tests were performed using a method of a single-plane cut along the surface of a CSM freezing with clay soils, as well as with the foundation material at a constant rate in accordance with State Standard R 56726-2015 and statistical data processing according to State Standard 20522-2012.Results. The article presents the results of laboratory studies on effects, caused by frost heaving tangential forces on piles during soil and CSM freezing, taking into account various factors (clay soil liquidity index, test temperature). Based on the obtained data, the authors propose a methodology for calculating the stability of driven precast piles. The method consists in determining the heaving force per unit area by adding the products of the seasonal freezing-thawing fractional depth, obtained by thermal engineering calculations or according to the plots, given in the article, by the tangential forces of frost heaving, obtained in laboratory studies.Conclusions. The developed methodology improves the reliability and accuracy of foundation calculations, enhances the efficiency of base and foundation design solutions, and reduces the labor capacity of driven precast pile installation.

Empowering Home Buyers: A Data-Ddriven Approach to Real Estate Pricing in Ames, Iowa

The demand for both housing and investment real estate has significantly increased due to rising urbanization and growing household savings. To address the need for operable real estate pricing models, this study explores potential variables affecting the sale prices of properties in Ames, Iowa, from 2006 to 2010. Utilizing data mining techniques and regression analysis, this study develops a model incorporating 12 independent variables that can be easily obtained during property visits. By offering an easily appliable tool, this research enables potential home buyers to estimate property sale prices, even without extensive expertise in Data Science, Investment, and Economics. The findings demonstrate that analyzing 12 variables directly related to the property itself such as interior finish of the garage, foundation material, and remodeling date can explain approximately 85.2% of the variance in sale prices. Empowering consumers with this knowledge can help reduce the information gap in the real estate market and promote informed decision-making in property purchases.

Application of electrical resistivity tomography and geotechnical techniques for identification and characterization of collapsible soils in Bafoussam (Western, Cameroon)

Road failure catastrophes have increased in frequency in the West Cameroon area. The collapsed soil characteristics that contribute to these phenomena in Bafoussam have been investigated using the geophysical investigation combined with geotechnical tests. The result of electrical resistivity tomography shows water conditions and heterogeneity of road foundation materials: resistivity values higher than 200 Ωm indicate dry materials, values between 30 and 200 Ωm define wet materials, and values lower than 30 Ωm indicate the very wet or water-saturated materials. These water-saturated materials can therefore move, bounded by a sliding surface of high-resistivity materials. Geotechnical properties analysis shows that these materials are clayey-sensitive water (64% clay fraction; A-7-6), very plastic (liquid limit: 46–63% plasticity limit: 29–39%), compressible, with high porosity (e > 0.8), low shear strength, and high friction angle (24–37°). The quality of foundation materials associated with high slopes (> 40°) and heavy rainfall in wet seasons (July–October) means that seepage water is the main factor responsible for the mass movement observed on the road of Western Cameroon. The construction or rehabilitation of these roads should be carried out in compliance with the natural conditions of the project site.Article highlights- 2D Electrical Resistivity Tomography method is able to determine the nature, subsurface structure and water conditions of road foundation soils.- Geotechnical test can be used to define the physical and mechanical properties of road foundation soils.- These two techniques complement each other to understand the mass movement observed on two sections of road failures caused by seepage water.

한중 고전 소재 드라마 OST의 조식 활용에 나타난 음악적 특징 비교분석 연구

The purpose of this paper is to understand the musical features in the use of modes in Korean and Chinese classical drama OSTs, with the intention of providing assistance to music creators who wish to produce OSTs for classical dramas. To achieve this, we explore the overall musical flow of classical drama OSTs, focusing on the analysis of the main insert songs' thematic melodies. In order to grasp the commonalities and differences, we analyze the thematic melodies of key insert songs, covering the period from 2020 to 2023, selecting the top 12 OST songs from dramas that entered the top 3 viewership rankings in Korea and China. As a result, commonalities and differences in the musical characteristics of OSTs from classical dramas in Korea and China were identified. It is hoped that this will contribute to exploring ways to utilize classical drama OST production and serve as valuable information and foundational material for the development of drama music genres.