Index Properties Research Articles

Assessing Alterations of Rainfall Variability Under Climate Change in Zengwen Reservoir Watershed, Southern Taiwan

This study aims to detect changes in rainfall variability caused by climate change for various scenarios in the CMIP6 (Coupled Model Intercomparison Project Phase 6) multi-model ensemble. Projected changes in rainfall unevenness in terms of different timescale indices using three categories, namely WD50 (number of wettest days for half annual rainfall), SI (seasonality index), and DWR (ratio of dry-season to wet-season rainfall) are analyzed in Zengwen Reservoir watershed, southern Taiwan over near future (2021–2040) and midterm future (2041–2060) relative to the baseline period (1995–2014) under SSP2-4.5 and SSP5-8.5 scenarios. The projected rainfall for both baseline and future periods is derived from 25 GCMs (global climate models). The results indicate that noticeably deteriorated rainfall unevenness is projected in the Zengwen Reservoir watershed over future periods, which include decreased WD50, increased SI, and decreased DWR. Though there were noticeable differences in the rainfall projections by the different GCMs, the overall consensus reveals that uncertainties in future rainfall should not be ignored. In addition, WD50 has the greatest deviated relative change in mean, which implies that the short-timescale rainfall unevenness index is easily affected by climate change in the study area. Distributional changes in rainfall unevenness determined by simultaneously considering alterations in relative changes in mean and standard deviation indicated that there was no single dominant category. However, the top two categories, with summed frequencies exceeding 0.5, characterize different properties of rainfall unevenness indices. The top two categories of WD50 and SI commonly have decreased mean and increased mean, respectively, but nearly equal frequencies of the top two categories in DWR exhibit opposite variations. The proposed rainfall unevenness change detection approach provides a better understanding of the impacts of climate change on rainfall unevenness, which is useful for preparing adaptive mitigation measures for coping with disasters induced by climate change.

Foundation Model Study on Inorganic and Biopolymer Nano Additives Treated Soil—A Step Forward in Nano Additive Soil Stabilization

For almost a decade, various studies have been carried out to prove the suitability of nano additives in enhancing the geotechnical properties of soil. Yet, this line of research is still in its elementary stage, restricting itself to laboratory tests to determine soil’s index and engineering properties blended with varying dosages of nano additives. In other words, research on practical applications of nano additives for soil stabilization is scarce. The present work attempts to investigate the suitability of three different nanomaterials as a load-bearing stratum for shallow foundations. The nano additives were chosen in such a way that each of them is from a different origin. One of them is nano calcium carbonate (inorganic) whereas the other two are nano-sized varieties of natural biopolymers, namely nano chitosan (crustacean-based) and nano carboxymethyl cellulose (plant-based). A series of laboratory tests were initially conducted to determine the strength of all three nano-additive-treated soils at different dosages, which were investigated for 180 days to ensure their long-term performance. This was followed by a foundation model study on untreated soil and on soil treated with optimal dosages of nano additives. The results were validated using finite element software followed by a parametric study to optimize the depth of soil stabilization. It was observed that all three nano additives exhibited a better performance when the top layer had the optimal dosage and the subsequent layers had a relatively lesser dosage.

Effect of Titanium Oxide (TiO2) Nanoparticles on the Opto-Mechanical Properties of Polyethylene Terephthalate (PET) Fibers

Polyethylene terephthalate (PET) is widely used in various applications due to its excellent mechanical properties and chemical resistance. However, PET fibers still lack specific features and functionalities that can be improved via nano-additives, particularly metal oxides. In this study, we investigate the effect of adding TiO2 nanoparticles to PET to form PET/TiO2 fibers and examine their opto-mechanical properties. This study utilizes optical interferometric techniques to assess how mechanical stretching influences the optical and mechanical properties of PET fibers treated with TiO2 nanoparticles. A Mach–Zehnder interferometric setup, integrated with a versatile device capable of mechanically stretching samples, is used to achieve this task. Variations in refractive index and birefringence along the longitudinal axis of undrawn and drawn PET/TiO2 fibers are examined. The research meticulously explores the fluctuations and spatial variations in the refractive index and birefringence properties, exhibiting anisotropy in optical behavior, along the longitudinal axis of unstretched and stretched PET/TiO2 fibers. The findings and outcomes derived from this comprehensive study provide substantive information that can facilitate the enhancement and optimization of the coupled optical and mechanical properties of materials explicitly engineered for advanced applications.

Tensile strength and durability performances-based evaluation of 3D-printed and mold-cast fibrous geopolymer composites produced at various alkaline activator combinations

This study aimed to investigate the effects of the sodium silicate-to-sodium hydroxide ratio, SH molarity, and carbon fiber volume fraction on the tensile strength and durability properties of mold-cast and 3D-printed geopolymer composites, including flexural and splitting tensile strengths, ultrasonic pulse velocity, water absorption, sorptivity index, and chloride penetration properties. For that purpose, the ground-granulated blast furnace slag and fly ash were employed as alumino-silicate-rich raw material. In order to activate the alumino-silicate-rich raw material, two sodium silicate/sodium hydroxide ratios of 1 and 2 and three sodium hydroxide molarities of 8M, 10M, and 12M were designated. Furthermore, carbon fiber was incorporated into the geopolymer composites at three volume fractions: 0%, 0.3%, and 0.6%. In total, 18 nonfibrous and fibrous geopolymer composites were manufactured in two different ways: mold-cast and 3D-printed. The findings demonstrated that the strength and durability characteristics of 3D-printed specimens were inferior to those of mold-cast specimens, attributed to the presence of weak interfacial bonds between layers. It has been observed that the incorporation of carbon fiber has the effect of improving tensile strength performance. Nevertheless, the addition of carbon fiber led to a slight decrease in UPV values, and an increase in water absorption and sorptivity index values. Also, it adversely influenced the chloride penetration of geopolymer composites. The findings of the study also indicated that increasing the sodium hydroxide molarity had a positive impact on the strength and durability properties of the composites. Nevertheless, it was observed that increasing the sodium silicate-to-sodium hydroxide ratio led to a decrease in both tensile strength and durability performances. Additionally, the microstructure of the geopolymer composites was analyzed using scanning electron microscope (SEM) images.

Contributions to Generalized Oscillation Theory of Linear Hamiltonian Systems

In this paper we present several new contributions to the oscillation theory of linear differential equations, in particular of linear Hamiltonian systems, when the traditional Legendre condition is absent. Following our recent work (Discrete Contin. Dyn. Syst. 43(12):4139–4173, 2023), we introduce the multiplicity of a generalized right focal point and derive the corresponding local Sturmian separation theorem. We also examine the relation between the existence of finitely many generalized right focal points, or in the special case the nonexistence of generalized right focal points, with the Legendre condition. As the main tools we use new notions of the minimal multiplicities at a given point and the dual comparative index — an object from matrix analysis or differential geometry (Maslov index theory). Furthermore, we study local limit properties of the dual comparative index and the comparative index and apply them for deriving new oscillation results phrased in terms of the generalized right and left focal points. The investigation of the interplay between generalized right and left focal points leads to conditions characterizing the situation, when in the local Sturmian separation theorem the corresponding multiplicities attain the minimal possible value. This also provides a generalization of the concepts of the right and left proper focal point defined by Kratz (Analysis 23(2):163–183, 2003) and Wahrheit (Int. J. Differ. Equ. 2(2):221–244, 2007) to the setting, which does not impose the Legendre condition. The results are new even for completely controllable linear Hamiltonian systems, including the Sturm–Liouville differential equations of arbitrary even order.

Uncertainty reduction in MASW inversion and ground response analysis using a-priori information

Multi-channel analysis of surface waves (MASW) method is commonly used for estimating the shear wave velocity (Vs) profile of soil and subsequent ground response analysis (GRA). However, the uncertainties from inversion non-uniqueness in MASW testing and the absence of soil type information in GRA can undermine their accuracy and affect seismic designs. Incorporating a-priori information from geotechnical investigations can be a potential solution, but its effectiveness in MASW testing is not well understood. This study aims to quantify the uncertainty reduction achieved by incorporating a-priori information in MASW testing and GRA. Extensive numerical simulations of MASW and GRA for nine idealized soil profiles were carried out. Subsequently, the findings were validated by carrying out field testing with and without a-priori information. The a-priori information included number and thickness of soil layers, soil type and index properties. The findings demonstrate that incorporating a-priori information significantly reduces inversion uncertainty in MASW and GRA, enhancing the reliability and accuracy of the analyses. This work provides a quantitative assessment of uncertainty reduction using a-priori information for different possible site and earthquake scenarios. The findings have important implications for design of earthquake-resistant structures and for improving the safety of people and infrastructure in earthquake-prone areas.

Some basic mathematical properties of the misbalance hadeg index of graphs

Some basic mathematical properties of the misbalance hadeg index of graphs

Topological Edge Spectrum Along Curved Interfaces

Abstract We prove that if the boundary of a topological insulator divides the plane into two regions, each containing arbitrarily large balls, then it acts as a conductor. Conversely, we construct a counterexample to show that topological insulators that fit within strips do not need to admit conducting boundary modes. This constitutes a new setup where the bulk-edge correspondence is violated. Our proof relies on a seemingly paradoxical and underappreciated property of the bulk indices of topological insulators: they are global quantities that can be locally computed.

Crude oil price behavior and the adoption of sustainable measures in companies before and after COVID-19

The objectives achieved in the Paris Agreement to reduce greenhouse gas emissions and reduce dependence on fossil fuels have caused, in recent years, a growing importance on sustainability in companies in order to reduce Environmental, social and economic impacts. This study is focused on understanding how the variation in West Texas Intermediate crude oil prices affects the Dow Jones Sustainability Index, and therefore the companies included in it, and vice versa. The research aims to examine the statistical properties of both indices, using fractional integration methods, the fractional cointegration vector autoregressive (FCVAR) approach and the continuous wavelet transform (CWT) technique. The results warn of a change in trend, with the application of extraordinary measures being necessary to return to the original trend, while the analysis of cointegration and wavelet analysis measures reflect that an increase in those adopted based on sustainability by the different companies that make up the index imply a drop in the price of crude oil.

Skip index: Supporting efficient inter-block queries and query authentication on the blockchain

Decentralized applications, the driving force behind the new Web3 paradigm, require continuous access to blockchain data. Their adoption, however, is hindered by the constantly increasing size of blockchains and the sequential scan nature of their read operations, which introduce a clear inefficiency bottleneck. Also, the growing amount of data recorded on the blockchain makes resource-constrained light nodes dependent on untrusted full nodes for fetching information, with a consequent need for query authentication protocols ensuring result integrity. Motivated by these reasons, in this paper we propose the skip index, an indexing data structure that allows users to quickly retrieve information simultaneously from multiple blocks of a blockchain. Our solution is also designed to be used as an authenticated data structure to guarantee the integrity of query results for light nodes. We discuss the theoretical properties of skip indices, propose efficient algorithms for their construction and querying, and detail their computational complexity. Finally, we assess the effectiveness of our proposal through an experimental evaluation on the Ethereum blockchain. As a reference use case, we focus on the popular CryptoKitties application and simulate a scenario where users seek to retrieve the events generated by the service. Our experimental results suggest that the use of skip indices offers a constant multiplicative speedup, thanks to search times that are at most logarithmic within a chosen search window. This allows to reduce the number of visited blocks by up to two orders of magnitude if compared to the naive sequential approach currently in use.

Measurement of validity and reliability of Bengali-translated Incontinence Severity Index questionnaire

ObjectiveThe purpose of the study was to verify the psychometric properties of the Bengali-translated Incontinence Severity Index (ISI) questionnaire.Materials and methodsA test–retest data collection method was conducted with 47 respondents using the Bengali-translated ISI questionnaire.ResultsThe mean age of the respondents was 41.4 years; standard deviation (S.D.) ± 9.90. Most of the women were suffering with moderate severity of urinary incontinence 48.9% (n = 23). The present study determined that Bengali-translated ISI questionnaire was valid and reliable. In addition, present study reflected on the content validity of the Bengali version of ISI questionnaire was 1 > 0.75; internal consistency α = 0.80 and intra-class correlation (ICC) = 0.86 respectively.ConclusionThe Bengali version of ISI questionnaire is valid and reliable measurement tool to extent the severity of urinary incontinence in the cultural context of Bangladesh.

Empirical Correlation of Hossaena Town Soil Index Properties with California Bearing Ratio (CBR) Values

California bearing ratio (CBR) is a key input factor in pavement structural design that is used to determine character size, the strength of unbound materials, and subgrade soils. The construction of a straightforward and logical regression model to forecast the CBR of unbound materials as a function of the index properties of the material. This work explains the relationship between compaction parameters and Atterberg limit tests. Laboratory test was conducted to get the independent (percent finer, liquid limit, plastic limit, plastic index, maximum dry density and moisture content), and dependent variables (CBR). A statistical package for social science software (SPSS) used to develop the mathematical model both in single and multiple regression. The viability of using multiple linear regression analysis to relate CBR values to soil index features was investigated. In this study, SPSS is used to examine each independent variable's significance individually. The multiple linear regression analysis was used to create the correlation, which had an eighteen-person sample size and a modest determination coefficient of R2 = 0.821. The CBR has good relation with maximum dry density and optimum moisture content compared to other parameters. This model applicable for small structure in the specified soil type, MH.

The Multiplicative Sum Zagreb Indices of Graphs with Given Clique Number

The multiplicative sum Zagreb index is a modified version of the well-known Zagreb indices. The multiplicative sum Zagreb index of a graph G is the product of the sums of the degrees of pairs of adjacent vertices. The mathematical properties of the multiplicative sum Zagreb index of graphs with given graph parameters deserve further study, as they can be used to detect chemical compounds and study network structures in mathematical chemistry. Therefore, in this paper, the maximal and minimal values of the multiplicative sum Zagreb indices of graphs with a given clique number are presented. Furthermore, the corresponding extremal graphs are characterized.

The Influence of Claystone Type on Landslide Hazard: A Case Study

The landslide is more common in locations with steep slopes and is unstable. Developing an early warning system is the aim of this study, which focuses on Nanggulan, Yogyakarta Special Region-Indonesia. The Nanggulan has a wavy shape with a minor slope and is made up of Eocene sedimentary rocks. The landslide indicators, such as curved walls, cracked roads, fractured building walls, subsided building floors, sinkholes, and the creation of crown scarps, were discovered at various sites. X-Ray Diffraction (XRD) analysis and soil index properties of rock and soil samples, were used in the research. The XRD examination revealed the presence of smectite-group clay minerals (monmorillonite and saponite). Calculating the soil index parameters yielded that the soil has a specific gravity of 2.173–2.62, water content of 18.207–47.653%, liquid limit of 45–77%, plastic limit of 21–43%, plasticity index of 18–42%, cohesiveness of 1–91 kPa, and a friction angle of 10°–54°. The direction of the slope is more than 20°, so there is little possibility of planar failure, and the Nanggulan is stable. However, from the smectite-group clay minerals, the plasticity index and the liquid limit value indicate that the rock is cohesive and easy to move when it is wet. This form of landslide typically occurs on gently sloping terrain, is controlled by expansive lithology, has a relatively slow movement rate, and indicates that the landslide type was creep.

Point Load Strength Index and Slake Durability Index of Marbles from the Kanti Highway, Central Nepal LesserHimalaya

Point Load Strength Index (PLSI) is determined to obtain the strength of the rock, while Slake Durability Index (SDI) offers quantitative data on the mechanical behavior of rocks exposed to cyclic wetting and drying. This study aims to find out such index properties of marbles from the Markhu Formation of Central Nepal, Lesser Himalaya. The study of the strength and durability of marbles is crucial to classifying strength and identifying resistance to weathering, deterioration patterns, and rock quality. Fresh rock samples were collected from 20 different locations within the Markhu Formation, exposed across the Kanti Highway. The SDI and PLSI tests were carried out. The study reveals that the PLSI ranges from 2.54 to 9.08 MPa, and the test samples belong to strong to very strong rock categories according to the calculated value of UCS, indicating that the marbles from the Markhu Formation are of good quality and are strong enough to withstand the load, contributing to rock mass quality. The marbles have extremely high second cycle SDI (Id2) of 98.92% to 99.50%, and therefore, a high resistance to the wetting and drying cycle, showing slow slaking behavior. Between the second and the fifth cycle, SDI (Id5) was deduced by about 1%. It implies that the marbles are highly resistant to weathering and erosion. Marble shows two kinds of disintegration after the second cycle and deteriorates under three types of patterns under five cycles.

Exploring the impact and influence of melanin on frequency-domain near-infrared spectroscopy measurements.

Near-infrared spectroscopy (NIRS) is a non-invasive optical method that measures changes in hemoglobin concentration and oxygenation. The measured light intensity is susceptible to reduced signal quality due to the presence of melanin. We quantify the influence of melanin concentration on NIRS measurements taken with a frequency-domain near-infrared spectroscopy system using 690 and 830nm. Using a forehead NIRS probe, we measured 35 healthy participants and investigated the correlation between melanin concentration indices, which were determined using a colorimeter, and several key metrics from the NIRS signal. These metrics include signal-to-noise ratio (SNR), two measurements of oxygen saturation (arterial oxygen saturation, , and tissue oxygen saturation, ), and optical properties represented by the absorption coefficient ( ) and the reduced scattering coefficient ( ). We found a significant negative correlation between the melanin index and the SNR estimated in oxy-hemoglobin signals ( , ) and levels ( , ). However, no significant changes were observed in the optical properties and ( , ). We found that estimated SNR and values show a significant decline and dependence on the melanin index, whereas and optical properties do not show any correlation with the melanin index.

Aqueous extract of CAP-ash: A greener benchmark for Suzuki-Miyaura coupling reaction in palladium catalyzed ligand-free condition

Synthesis, molecular, spectroscopic properties, and electronic structure calculations of biphenyls derivatives have been achieved using a highly efficient catalytic amount of Pd(OAc)2 in aqueous extract of custard apple peels (CAP)-ash (AECAP) a green, highly cost-effective, operationally convenient and environmentally benign media at ambient temperature. The analytical reports showed the presence of metal oxides which are probably extracted in water produces corresponding hydroxides, which provide alkaline media in water which shows dual performance (solvent and base) for said cross-coupling transformation. The catalytic system is generated in situ based on aqueous extract and Pd(OAc)2 which requires no external base and ligand. Moreover, the study also offers insights into the frontier molecular orbitals (FMO), electronegativity, chemical potential, global electrophilicity index, ionization potential, electron affinity, chemical hardness, and softness properties of the synthesized biphenyl derivatives for understanding their stability, active sites, and biological activity using density functional theory (DFT) at the B3LYP/6–311G(d,p) level/basis.

Translation, cross-cultural adaptation and validation of psychometric properties of foot function index in Urdu-speaking population with ankle and foot disorders

BackgroundFoot and ankle problems are frequently prevalent, especially among the elderly, ranging from 70 to 80%. In primary care, foot, and ankle complaints stand out as one of the most frequent reasons for orthopedic consultations. Patient-reported outcome measures are significant in the assessment burden of any condition on the effects of intervention as well as research. The Foot Function Index (FFI) is a region-specific tool that was identified as one of the most commonly used evaluation tools for foot complaints. This study aimed to translate, cross-cultural adapt, and test the psychometric properties of FFI in the Urdu language.MethodologyThe FFI was translated into Urdu language (FFI-U) following Beaton et al. translation guidelines. The data were collected from 230 Urdu-speaking participants with different foot and ankle pathologies. Data collection started after the written informed consent from the participants. All participants completed the FFI-U, Visual Analogue Scale (VAS), SF-36, and the Foot and Ankle Outcome Score (FAOS) at baseline while only 30 participants completed ULFI-U after one week for test-retest reliability. The psychometric properties involved reliability and validity testing. Reliability was assessed where internal consistency was measured using Cronbach’s alpha and test-retest reliability through the intra-class correlation coefficient (ICC). FFI-U was tested for face validity and construct validity (convergent and discriminant). Psychometric criteria were examined against priori hypotheses, and alpha level (p-value < 0.05) was considered statistically significant.ResultsFFI-U demonstrated good reliability with internal consistency (α = 0.86) and test-retest reliability with intra-class correlation coefficient = 0.845 (0.78–0.89). A moderate correlation was found using Pearson correlation between FFI-U total score and physical components of SF-36, VAS (pain, disability), and FAOS (γ= -0.65, 0.72, 0.71, -0.68) respectively, indicating convergent validity however, a weak correlation was found with mental components of SF-36 (γ=-0.25) demonstrating discriminant validity. Face validity was assessed at the pre-final testing stage by interviewing patients. There were no floor and ceiling effects found for FFI-U.ConclusionThe FFI-U has been found reliable, valid, and feasible tool to be used as a patient-reported outcome measure to assess functional levels with different foot and ankle disorders in Urdu speaking population.

Enhancing Deep Excavation Optimization: Selection of an Appropriate Constitutive Model

To minimize the impact on nearby structures during deep excavations, choosing an appropriate soil constitutive model for analysis holds significant importance. This study aims to conduct a comparative analysis of various constitutive soil models—namely, the Mohr–Coulomb (MC) model, the hardening soil (HS) model, the hardening soil small strain (HSS) model, and the soft soil (SS) model—to identify the most suitable model for the lacustrine deposit. To implement these models, the soil’s index properties and mechanical behavior were evaluated from undisturbed soil samples. The numerical simulation and verification of these properties were carried out by comparing the laboratory test results with the outcome of the finite element method; the most suitable constitutive soil model for the soil was identified as the HSS model. Upon analyzing the wall deflection and ground settlement profiles obtained from respective constitutive models, it was observed that the HS and HSS models exhibit similar characteristics and are well-suited for analyzing typical lacustrine soil. In contrast, the MC and SS models yield overly optimistic results with lower wall deflection and ground settlement and fail to predict realistic soil behavior. As a result, this research highlights the significance of selecting the appropriate constitutive soil model and refining the parameters. This optimization process contributes significantly to the design of support systems, enhancing construction efficiency and ensuring overall safety in deep excavation projects.

Effects of elevated temperature and treatment duration on selected index and engineering properties of lateritic soils

Lateritic soils are important to various engineering applications, especially in tropical regions, where they serve as key components in road construction, embankments, and other geotechnical structures. This study investigated the combined effects of elevated temperature and heating duration on the index and engineering properties of lateritic soils derived from two distinct parent rocks (charnockite and quartzite) in Ado-Ekiti, Nigeria. Disturbed lateritic soil samples were heated in a furnace at various temperatures (100, 200, 300, and 400 °C) for two designated durations (2 and 3 h). Standard geotechnical tests were conducted to evaluate Atterberg limits, compaction parameters, and unconfined compressive strength. The results showed that elevated temperature led to a decrease in the plastic limit, liquid limit, plasticity index, optimum moisture content (OMC), and UCS for both soils, though the extent varied between the two parent rocks. For instance, at 400 °C for 3 h, the plasticity index decreased by 47.82% for charnockite-derived soil and 55.22% for quartzite-derived soil. At the same temperature for 2 h, it decreased by 38.79% for charnockite-derived soil and 48.92% for quartzite-derived soil. Similarly, UCS decreased by 29.83% for charnockite-derived soil and 25.97% for quartzite-derived soil at 400 °C for 3 h, while at 400 °C for 2 h, UCS decreased by 21.20% for charnockite-derived soil and 23.48% for quartzite-derived soil. Conversely, maximum dry density (MDD) increased with temperature, rising by up to 20.64% for charnockite-derived soil and 14.66% for quartzite-derived soil at 400 °C for 3 h, and by 18.29% for charnockite-derived soil and 12.62% for quartzite-derived soil at 400 °C for 2 h. Longer heating durations (3 h) generally caused more pronounced changes in soil properties compared to shorter durations (2 h). For instance, OMC decreased by 13.41% for charnockite and 14.18% for quartzite at 400 °C for 3 h compared to a 2-h duration. Statistical analyses indicated that temperature had a significant influence on most properties, while the effect of heating duration was less consistent. These findings highlight the need to consider both temperature and heating duration when evaluating the engineering behavior of lateritic soils exposed to elevated temperatures. Practical implications include potential adjustments in construction practices and design parameters for road construction and embankments in regions prone to high temperatures, such as those experiencing frequent forest fires.