Database Of Properties Research Articles

Laser echo waveform modulation modelling from lateral structure using a mathematical formula

ABSTRACT The relationship between the axial structures of three-dimensional (3-D) targets and the signal of the remote-sensing techniques, such as the modulated echo waveform of the full-waveform light detection and ranging (FW-LiDAR), has been well established. However, the relationship between the lateral structures on modulated echo waveform has not been exploited in detail. For FW-LiDAR, the peak intensity, rather than the shape and width, of the echo waveform reflects lateral structural information. Using four typical two-dimensional shapes to approach the lateral structures, a mathematical formula bridging the peak intensity and the lateral structures is derived. Based upon the echo waveform simulated using the formula, modulations of the lateral structural information on the peak intensity are examined to establish a database of target properties, including shape, size and position. The physics regarding peak intensity dependence on target position is used for facile shape recognition. The modulation of the lateral shapes of ground and aerial targets on the FW-LiDAR can be assessed extensively following the procedure demonstrated in this paper. Owing to the conciseness, the peak intensity formula enables the retrieval of lateral structural information by inversion, promoting the applications of FW-LiDAR in domains including topological mapping, ecological monitoring and space debris detection and removal.

Soil Properties Study for the Western Side of Kut City, Iraq

Soil properties checks and classification are an important part of any engineering project as they directly affect buildings as well as agriculture and others. The research aims to create an integrated database for soil properties in the study area, which is the western side of the city of Kut, to know its relationship to groundwater in the region. Laboratory tests were conducted for five soil samples from the Bar Drilling sites to monitor the movement of groundwater in the area. Soil samples were taken when drilling and upon reaching the groundwater level, which was approximately 6 meters sieve analysis, hydrometer, specific gravity, and hydraulic conductivity were also conducted, as well as the content of chlorides and sulfates in the soil was calculated. For classifying testure of the soil, the triangle of US agriculture department was utilized, soil can be divided into groups by this triangle based on clay, silt and sand proportion. Results of examination of soil texture showed that the soil in the first was Clay loam and the second point was Silty Clay loam and in the third point, it was sandy clay loam, while in the fourth point it was silty clay loam and it was in the fifth point silt loam As shown in Table 1. The specific gravity was measured in the field, and the lowest value was 2.65 in the third well, while the highest value was 2.70 in the fifth well. The hydraulic conductivity of the five well points was calculated and was close to each other and considered as an average value of hydraulic conductivity equal to 0.013522. The content of chlorides and sulfates in the soil was calculated due to its importance in knowing the chemical properties. The results showed that the value of the chlorides ranged between (0.154 - 1.72) %, while the values of the sulfate content in the soil ranged between (0.930 - 3.11) %.

Derivation and validation of a reference data-based real gas model for hydrogen

Hydrogen plays an important role for the decarbonization of the energy sector. In its gaseous form, it is stored at pressures of up to 1000 bar at which real gas effects become relevant. To capture these effects in numerical simulations, accurate real gas models are required. In this work, new correlation equations for relevant hydrogen properties are developed based on the Reference Fluid Thermodynamic and Transport Properties Database (REFPROP). Within the regarded temperature (150–400 K) and pressure (0.1–1000 bar) range, this approach yields a substantially improved accuracy compared to other data-based correlations. Furthermore, the developed equations are validated in a numerical simulation of a critical flow Venturi nozzle. The results are in much better accordance with experimental data compared to a cubic equation of state model. In addition, the simulation is even slightly faster.

Thermophysical Characterization of Paraffins versus Temperature for Thermal Energy Storage

Latent heat storage systems (LHSS), using solid–liquid phase change materials (PCMs), are attracting growing interest in many applications. The determination of the thermophysical properties of PCMs is crucial for selecting the appropriate material for an LHSS and for predicting the thermal behavior of the PCM. In this context, the thermophysical characterization of four paraffins (RT21, RT27, RT35HC, RT50) at different temperatures, including the solid and liquid phases, is conducted in this investigation. This work is part of a strategic technological brick in the CERTES laboratory of the Paris Est University to build a database for phase change material properties. It contains the measurements of the thermophysical, optical and mechanical properties. It will serve as input for the numerical simulations to study the behavior of PCMs in LHSS. The temperatures and the latent heats of the phase transitions as well as the thermal dependence of the specific heat of the paraffins were evaluated by differential scanning calorimetry (DSC). In addition, the DSC measurements under successive thermal cycles revealed good reliability of the paraffins. Thermogravimetric analysis (TGA) was performed, and the results highlighted the thermal stability of the paraffins. Moreover, the evolutions of the thermal conductivities and diffusivities with temperature were measured simultaneously using the hot disk method. A discontinuity of the thermal conductivities was observed near the melting temperatures. Furthermore, the measurements of the densities of the paraffins at different temperatures were carried out. The volume changes and the coefficients of thermal expansion were assessed. The obtained outcomes of this study were compared with the available bibliographical data.

Characterization of an Iron Ore Tailing Sample and the Evaluation of Its Representativeness

The massive annual tonnage of iron ore tailings, plus the more demanding environmental policies after the catastrophic collapses of Fundão Dam in 2015 and Feijão Dam I in 2019, have forced Brazilian mining companies to search for more sustainable and safer alternatives for tailings disposal. The Brazilian mining industry has been studying the dry stacking of filtered tailings. Most companies seek the development of great dry stacks, over 200 m high, to absorb the whole tailings generation. As tailings assume a structural role, it is vital to characterize the dry stacks and understand their behaviour. This study aimed to characterize index properties, evaluate the effect of compaction on the hydraulic behaviour, and evaluate field variability of iron ore tailings from a mine in Quadrilátero Ferrífero, Brazil. Also, a database of iron ore tailings properties from Quadrilátero Ferrífero was collected and used to evaluate the results. Specimens were compacted to 93%, 95%, 97%, and 100% of Proctor’s maximum dry unit weight, and the hydraulic conductivity was defined for several confining pressures (100, 200, 400, 800, 1600 and 1900 kPa) for each degree of compaction. Index properties of the studied tailing were similar to other iron ore tailings from the Quadrilátero Ferrífero, hydraulic conductivity was proportional to the void ratio, and the field tests indicated some variability of both material properties and degree of compaction of the stacked material. The database presented in this study supplies the mining industry with a reference point for future projects.

A stochastic neural network based approach for metamodelling of mechanical asphalt concrete properties

ABSTRACT This study introduces a stochastic approach based on Convolutional Neural Networks (CNNs) for predicting mechanical Asphalt Concrete (AC) properties with dependency on the mixture composition, temperature and loading frequency. The underlying CNN metamodels were evaluated by a comprehensive database of AC properties with a total of 7400 dynamic modulus records. The CNN approach shows an improved accuracy compared to other state of the art machine learning approaches found in literature. Stochastic CNN based metamodels were developed to take into account the uncertainty of mechanical properties resulting from arbitrarily arranged aggregates and air voids in AC. The data used for the stochastic metamodels contain a total of 3645 dynamic modulus and phase angle values. They were obtained from microscale Finite Element (FE) simulations considering a heterogenous material composition and viscoelastic material behaviour of the AC binder. The developed stochastic CNN metamodels provide highly accurate predictions for the statistical characteristics such as mean values, standard deviations and empirical distribution functions of the dynamic modulus and the phase angle.

Development of interactive guidance for cold exposure using a thermoregulatory model

ABSTRACT For decades, the Wind Chill Temperature Index (WCT) and its various iterations have been used to assess the risk of frostbite on unclothed body parts. This paper presents an innovative knowledge-based Cold Weather Ensemble Decision Aid (CoWEDA) that can be used to guide the selection of the most appropriate cold weather ensemble(s) relative to anticipated mission physical activities and environmental conditions. CoWEDA consists of a validated six-cylinder thermoregulatory model, a database of clothing properties, algorithms for calculating the whole ensemble properties from individual garments and a graphical user interface. The user-friendly CoWEDA allows users to select from an inventory of clothing items to build an ensemble suitable for their needs. CoWEDA predicts the risks of both frostbite and hypothermia and ensures that a selected clothing ensemble will provide adequate protection to prevent cold injury. CoWEDA predictions provide not only estimates of frostbite risk similar to WCT tables but also hypothermia times and clothing required to prevent cold injuries. In addition, a CoWEDA model variant can predict survivability and clothing requirements during cold water immersion. Thus, CoWEDA represents a significant enhancement of the WCT-based guidance for cold weather safety and survival by providing greater individual fidelity in cold injury predictions.

Ecotoxicological QSAR study of fused/non-fused polycyclic aromatic hydrocarbons (FNFPAHs): Assessment and priority ranking of the acute toxicity to Pimephales promelas by QSAR and consensus modeling methods

Fused/non-fused polycyclic aromatic hydrocarbons (FNFPAHs) have a variety of toxic effects on ecosystems and human body, but the acquisition of their toxicity data is greatly limited by the limited resources available. Here, we followed the EU REACH regulation and used Pimephales promelas as a model organism to investigate the quantitative structure-activity relationship (QSAR) between the FNFPAHs and their toxicity for the aquatic environment for the first time. We developed a single QSAR model (SM1) containing five simple and interpretable 2D molecular descriptors, which met the validation of OECD QSAR-related principles, and analyzed their mechanistic relationships with toxicity in detail. The model had good degree of fitting and robustness, and had better external prediction performance (MAEtest = 0.4219) than ECOSAR model (MAEtest = 0.5614). To further enhance its prediction accuracy, the three qualified single models (SMs) were used for constructing consensus models (CMs), the best one CM2 (MAEtest = 0.3954) had a significantly higher prediction accuracy for test compounds than SM1, and also outperformed the T.E.S.T. consensus model (MAEtest = 0.4233). Subsequently, the toxicity of 252 true external FNFPAHs from Pesticide Properties Database (PPDB) was predicted by SM1, the prediction results showed that 94.84 % compounds were reliably predicted within the model's application domain (AD). We also applied the best CM2 to predict the untested 252 FNFPAHs. Furthermore, we provided a mechanistic analysis and explanation for pesticides ranked as top 10 most toxic FNFPAHs. In summary, all developed QSAR and consensus models can be used as efficient tools for predicting the acute toxicity of unknown FNFPAHs to Pimephales promelas, thus being important for the risk assessment and regulation of FNFPAHs contamination in aquatic environment.

A comparison of cabbage crop growth parameters and harvest maturity indices under different planting methods, with an emphasis on mechanical harvesting

The predominant method of cabbage harvesting in India is manual labor, which is both time-consuming and physically demanding. However, the introduction of mechanical harvesting could offer a viable solution to this problem. A plant physical properties database is needed before the developing mechanical harvesting system design. In view of this, a study was conducted to examine the effect of planting methods (flat, ridge-furrow and ridge-furrow with plastic mulch) on physical growth and harvesting age of crop and thereby find out the most suitable planting method for mechanical harvesting. For two cabbage cultivars (Syngenta BC-79 and S-996), the effect of planting methods on physical growth parameters (plant height, plant diameter, length of leaf stem, length of stem, stem diameter, head diameter, and head weight) and harvest maturity indices (compactness, specific gravity, total soluble solids, pH, and pattern of wrapper leaves) was studied. The planting methods had shown a significant effect on growth parameters such as plant height (270.56 mm), plant diameter (549.39 mm), stem length (58.61 mm), stem diameter (34.58 mm), head diameter (144.89 mm) and head weight (1.12 kg) at harvest. The maximum number of matured heads (83.66%) was recorded in ridge-furrow with mulch planting. The interaction effect of planting methods and cultivars was found to be non-significant for all physical growth indicators. The findings of this study provide a valuable planting method for cabbage growers from the perspective of mechanical harvesting.

Reduction of Watercrafts Vibroacoustic Activity by Vibration Damping Materials

Introduction. Electric machines, diesel installations, pumping units and fans, as well as working bodies of dredgers (pipelines, scoops, rippers, etc.) are the main sources of noise and vibration on watercrafts. Moreover, the main harmful factors in the operation of floating cranes and dredgers are both the vibration itself and the accompanying phenomena of infrasound and structural noise. One of the most urgent tasks for the introduction of technosphere safety methods on watercrafts is to reduce the harmful effects of vibroacoustic factors on the health of personnel. The research objective is to improve the working conditions of watercrafts drivers by introducing the method of designing vibration protection systems proposed by the authors, taking into account both the external factors (ambient temperature) and the dynamic characteristics of vibration damping materials. The possibility of choosing the most rational vibration damping material based on the engineering calculation of the required vibration insulation is shown. Materials and Methods. A passive method of vibration control has been applied, in which elastic elements and vibration damping material are used in the watercraft design. The sources of noise and vibration have been identified, and their actual exposure levels have been determined. The analysis of dynamic characteristics and properties of vibration damping materials is carried out. The factors influencing the efficiency of vibration damping are revealed. Results. A design scheme of the vibration damping model at the workplace of the watercraft driver has been developed. An analytical database of dynamic characteristics and properties of vibration damping materials has been created. An engineering method for calculating the effectiveness of vibration insulation has been adapted to watercrafts. The calculations of the effectiveness of vibration insulation using various vibration damping materials of different thicknesses have been performed, on the basis of which the advantages of vibration damping flooring made of elastomeric plate VEP20 have been proved. Discussion and Conclusion. The engineering methodology developed in Excel for calculating the effectiveness of vibration insulation is automated and has a user-friendly interface. This allows you to calculate and reasonably select multilayer structures taking into account the ambient temperature, as well as the dynamic characteristics of vibration damping materials depending on the spectrum of noise and vibration. The results obtained can be used in the design of vibration protection systems for watercraft drivers.

Set it and forget it? Financing retirement in an age of defaults

Retirement savings abandonment is a rising concern connected to defined contribution systems and default enrollment. We use tax data on Individual Retirement Accounts (IRAs) to establish that for a recent cohort, 0.4% of retirement-age individuals abandoned an aggregate of $66 million, proxied by a failure to claim over ten years after a legal requirement to do so. Analysis of state unclaimed property databases suggests that workplace defined contribution plans are abandoned at a higher rate than IRAs. Finally, regression discontinuity estimates show that certain accounts created by default enrollment are at higher risk of abandonment by passive savers.

Analysis of Scientific and Technological Perspectives on the Development of New Food Products from Family Farming

This study aimed to identify the development of new food products related to family farming from scientific and technological perspectives. Data were collected from the scientific literature and patent documents in the Scopus and National Institute of Industrial Property databases, using a combination of terms, such as “family farm* OR small-hold farm* OR agricultur* farm* labor OR farm* size OR peasant farm* OR agriculture* food* product* AND food* product*”. The asterisk (*) denotes a truncation character used in articles and patent databases to perform a search using multiple terms with the same root but different suffixes. A total of 716 articles and 532 patents were identified. The data from the scientific articles provide an overview of family farming participation in the development of food products and how products that are developed by family farmers resonate with society. The patent documents found showed the development of innovative production technologies, such as machines and production methods to improve the quality of the products sold by family farmers. Therefore, there is great potential for family farming foods to advance in this technological area, with the prospect of increasing publications and new patent applications related to this subject.

Client base as an intangible asset

Keywords: intellectual capital, goodwill, customer base, intangible asset, identifiableassets, unidentified assets, database, trade secret
 In the article, the author raises questions about one of the important components of the company's intellectual capital, which determines the company's competitiveness — the «customer base». Such an asset,according to domestic legislation, is not recognized as an intangible asset. Internationalstatistics of merger agreements (unification) of companies determine that this asset accountsfor the largest share of the value of the entire agreement. In this regard, theanalysis of the concept of «customer base», the identification of features of accountingand evaluation of the «customer base» for reporting purposes. Moreover, the study of acceptableevaluation methods in practice are tasks that are extremely relevant both fordomestic companies participating in integration processes, and for evaluators performingwork on the evaluation of relevant intangible assets.The article analyses the definition of the term «intellectual capital» and its constituentpart — the «client base» of the enterprise. The author conducted a study of theeconomic and legal tools for defining the «customer base» as an intangible asset of the enterprise.Within the scope of the research, the legislative acts defining the requirementsfor the «customer base» as an object of intellectual property rights, namely commercialsecrets and databases, were analysed. The requirements that the «customer base» mustmeet as an intangible asset within the limits of Ukrainian and international legislation,as well as the peculiarities of accounting and evaluation of the «customer base» of the enterprise,are determined. The author has defined the problems in the issue of scientificsubstantiation at the legislative level of the term «customer base», as well as its definitionas an intangible asset of the enterprise and the object of assessment. The author emphasizesthat this direction of methodical work has an actual trend, with the aim of harmonizingthe provisions of national and international legislation.

Optimal Regional Allocation of Future Population and Employment under Urban Boundary and Density Constraints: A Spatial Interaction Modeling Approach

This paper develops an optimization modeling framework to select strategies of land development and population and employment densities for a growing metropolitan area. The modeling core involves a non-linear commuting model, which accounts for spatial structure variables and is empirically estimated by Tobit regression. This commuting model is then embedded into a non-linear optimization model that allocates increments in the population and employment (activities) to available land, while minimizing the total future commuting costs under various combinations of land expansion boundaries and population and employment densities. The resulting minimum cost surface is approximated via polynomial regression and combined with land development and congestion cost functions to derive the overall optimal strategy. These models are estimated and calibrated with data from the Census Transportation Planning Package (CTPP) and Auditor’s property database, and are applied to the Fredericksburg metropolitan area, Virginia. The results demonstrate that the optimal development densities are very sensitive to the congestion cost function. A land development strategy that allows for limited sprawl might be a smart policy to reduce both regional vehicle mile travel (VMT) and related congestion and pollution.

Database of thermophysical properties of H2/CO2/CO/CH4/H2O mixtures

As a potential alternative to fossil fuel, hydrogen has attracted much attention due to its renewable and environmentally friendly properties. Systems built for hydrogen-production and hydrogen-application tend to be larger, more integrated and more complex. In order to more efficiently design the vital components of hydrogen energy systems, accurate estimations of the thermodynamic and thermophysical properties of hydrogen-containing mixtures involved is essential. In this study, we introduced methods typically for calculating the thermodynamic and thermophysical properties of H2/CO2/CO/CH4/H2O mixtures, and established the technical database covering a wide range of mole fractions, pressures and temperatures. Moreover, a user-friendly software integrating all the calculation methods called H2MixThermoDatabase is compiled, whose code has been made available on the GitHub page for other researchers to effectually facilitate the further developments of hydrogen energy system.

Test Database for Corroded Prestressing Steel Strands Recovered from Aged Bridges

To evaluate the structural safety of corroded prestressed concrete structures, it is necessary to define the deteriorated mechanical behaviors of corroded prestressing steel strands. However, no standard provides a quantified relationship between the level of corrosion and the residual mechanical properties, and no consensus for such quantification has been reached. The aim of this study was to provide a test database for the residual mechanical properties of corroded prestressing steel strands. Strands recovered from aged bridges were naturally corroded, and an evaluation method for the corrosion level was suggested. In addition, corrosion assessment criteria were suggested based on characteristics of the corrosion appearance.

A Microphysics-Scheme-Consistent Snow Optical Parameterization for the Community Radiative Transfer Model

Abstract The satellite observational data assimilation community requires consistent hydrometer descriptions—including mass–size relation and particle size distribution—to be used in both the forecast model and observation operator. We develop a microphysics-scheme-consistent snow and graupel single-scattering property database to meet this requirement. In this database, snowflakes are modeled as a mixture of small column and large aggregated ice particles, the mixing ratios of which may be adjusted to satisfy a given mass–size relation. Snow single-scattering properties are computed for four different mass–size relations. Subsequently, the snow description in the Thompson microphysics scheme is used as an example to demonstrate how microphysics-scheme-consistent snow bulk optical properties are derived. The Thompson-scheme-consistent snow bulk optical properties are added to the Community Radiative Transfer Model (CRTM), version 2.4.0. With CloudSat Cloud Profiling Radar (CPR) snow and liquid precipitation retrievals as the inputs, CRTM simulations are performed over global oceans and compared with four collocated Global Precipitation Measurement (GPM) Microwave Imager (GMI) high-frequency channel observations. The CRTM simulated brightness temperatures show agreement with the GMI observed brightness temperatures in cases of light-to-moderate precipitation over extratropical and polar ice-free oceans, with root-mean-square errors of 4.3, 13.0, 1.8, and 3.3 K in the 166-GHz (vertical polarization), 166-GHz (horizontal polarization), 183 ± 3-GHz (vertical polarization), and 183 ± 7-GHz (vertical polarization) channels, respectively. The result demonstrates the potential of using the newly developed microphysics-scheme-consistent snow optical parameterization in data assimilation applications.

Study on efficient and accurate protocols of measuring sorption isotherm of porous building materials using three-dimensional hygrothermal simulation

The sorption property of porous building materials in the hygroscopic region (sorption isotherm) is an important input to hygrothermal simulation. In this study, we proposed efficient and accurate protocols to obtain sorption isotherms using the static desiccator method. We developed a calculation model for three-dimensional simultaneous heat and moisture transfer in a material corresponding to the measurement specified in ISO 12571. Using an international database of the material properties, we conducted numerical simulations of the sorption process for five types of materials. The evolution of the amount of adsorbed moisture in a specimen and the time to reach equilibrium during the measurement were calculated under various humidity levels and specimen dimensions. According to the simulated results, we improved timing and interval for weighting the specimen to confirm the attainment of equilibrium for each type of a material and for each humidity level from the viewpoint of efficiency and accuracy. Meanwhile, the influence of size of a specimen on the time necessary to obtain the results was quantitatively demonstrated. Moreover, it was demonstrated that the method used for the determination of the attainment of equilibrium provided in ISO 12571 can underestimate the moisture content of materials with low moisture content and vapor permeability, and a policy to reduce risks of the underestimation was proposed.

A Detailed Database of the Chemical Properties and Methane Potential of Biomasses Covering a Large Range of Common Agricultural Biogas Plant Feedstocks

Agricultural biogas plants are increasingly being used in Europe as an alternative source of energy. To optimize the sizing and operation of existing or future biogas plants, a better knowledge of different feedstocks is needed. Our aim is to characterize 132 common agricultural feedstocks in terms of their chemical composition (proteins, fibers, elemental analysis, etc.) and biochemical methane potential shared in five families: agro-industrial products, silage and energy crops, lignocellulosic biomass, manure, and slurries. Among the families investigated, manures and slurries exhibited the highest ash and protein contents (10.3–13.7% DM). High variabilities in C/N were observed among the various families (19.5% DM for slurries and 131.7% DM for lignocellulosic biomass). Methane potentials have been reported to range from 63 Nm3 CH4/t VS (green waste) to 551 Nm3 CH4/t VS (duck slurry), with a mean value of 284 Nm3 CH4/t VS. In terms of biodegradability, lower values of 52% and 57% were reported for lignocelluloses biomasses and manures, respectively, due to their high fiber content, especially lignin. By contrast, animal slurries, silage, and energy crops exhibited a higher biodegradability of 70%. This database will be useful for project owners during the pre-study phases and during the operation of future agricultural biogas plants.

High-throughput design of energetic molecules

High-throughput design of energetic molecules implemented by molecular docking, AI-aided molecular design, an automated computation workflow, a structure−property database, deep learning QSPRs and an easy-to-use platform.