Empirical Calculations Research Articles

Investigating empirical and theoretical calculations for intensity ratios of L-Shell X-ray transitions in atoms with 39 ≤ Z ≤ 94

The significance of theoretical, experimental, and analytical methods in calculating the intensity ratios of L-shell transitions for diverse elements lies in their widespread applications across various domains, including physical chemistry and medical research. In the present paper, empirical values for intensity ratios were computed through polynomial interpolations using experimental databases within the scope of atomic number 39 ≤ Z ≤ 92 for ILβILα and ILγILα, and extending to the range of 39 ≤ Z ≤ 94 for ILlILα. Additionally, new theoretical calculations were conducted using the Multiconfiguration Dirac–Fock Method for specific elements. The obtained results were compared with standard theoretical, experimental, and empirical values, showing a reasonable agreement with them.

Next-generation multicomponent SMAs: leveraging HEA empirical parameters

Empirical rule calculation, commonly used for phase selection of high entropy alloys (HEAs), provides valuable guidelines for designing multicomponent solid solutions. It is unknown whether the technique can offer a similar design strategy for multicomponent intermetallics that undergo B2−B19′ transformation. Establishing such guidelines can significantly accelerate the pace of discovery for new shape memory alloys (SMAs) by narrowing down the search area within the vast compositional design space of multicomponent alloys. In this study, we compiled hundreds of data on medium and high-entropy NiTi-based alloys exhibiting B2−B19′ transformation. Our objective was to construct a more comprehensive Ω−δ map and locate multicomponent SMAs on it. Additionally, we conducted a thorough analysis to establish a correlation between transformation temperatures and compositional features in medium and high-entropy SMAs (ME and HE-SMAs). This correlation can be leveraged to design SMAs with targeted transformation temperatures.

Multi-Source Feature-Fusion Method for the Seismic Data of Cultural Relics Based on Deep Learning.

The museum system is exposed to a high risk of seismic hazards. However, it is difficult to carry out seismic hazard prevention to protect cultural relics in collections due to the lack of real data and diverse types of seismic hazards. To address this problem, we developed a deep-learning-based multi-source feature-fusion method to assess the data on seismic damage caused by collected cultural relics. Firstly, a multi-source data-processing strategy was developed according to the needs of seismic impact analysis of the cultural relics in the collection, and a seismic event-ontology model of cultural relics was constructed. Additionally, a seismic damage data-classification acquisition method and empirical calculation model were designed. Secondly, we proposed a deep learning-based multi-source feature-fusion matching method for cultural relics. By constructing a damage state assessment model of cultural relics using superpixel map convolutional fusion and an automatic data-matching model, the quality and processing efficiency of seismic damage data of the cultural relics in the collection were improved. Finally, we formed a dataset oriented to the seismic damage risk analysis of the cultural relics in the collection. The experimental results show that the accuracy of this method reaches 93.6%, and the accuracy of cultural relics label matching is as high as 82.6% compared with many kinds of earthquake damage state assessment models. This method can provide more accurate and efficient data support, along with a scientific basis for subsequent research on the impact analysis of seismic damage to cultural relics in collections.

Development of a novel Ti35Nb25Zr15Mo15V10 high-entropy alloy for metallic biomaterials

Ti–6Al–4V alloy has been widely used as implant materials for biomedical applications. However, the inadequate corrosion resistance and the released metal ions could result in inflammation, cytotoxicity, and shorten the lifespan of implants. To extend the service life of biomaterials, the Ti35Nb25Zr15Mo15V10 high-entropy alloy was designed based on empirical and thermodynamic calculations to achieve a high-performance biomaterial with a potential to replace Ti–6Al–4V alloy. Investigations on the fabricated alloy revealed formation of body-centered cubic solid solution with no intermetallic compound. Nanoindentation experiments indicated a Young's modulus of 118 for the designed alloy which is lower than the elastic modulus of the Ti–6Al–4V alloy. Corrosion behavior of the Ti35Nb25Zr15Mo15V10 and Ti–6Al–4V alloys were investigated and the results represented a low passive current density of ∼10−2 A/m2 for the novel alloy which displayed superior corrosion resistance. In addition, the developed alloy provided higher bio-corrosion resistance compared with the Ti–6Al–4V alloy with superior pitting resistance and low concentration of released ions in a PBS solution. The Ti35Nb25Zr15Mo15V10 alloy revealed acceptable in-vitro biocompatibility performance for adhesion, viability, and proliferation of MG63 pre-osteoblasts. The preliminary benefits of the designed alloy over current metallic implants provide an opportunity to explore the development of new orthopedic-implant alloys.

LithoSFR Model for Mapping Groundwater Potential Zones Using Remote Sensing and GIS

Groundwater is a significant source of water supply, especially with depleted and quality-deteriorated surface water. The number of drilled boreholes for groundwater has been increased, but erroneous results often occur while selecting sites for digging boreholes. This makes it necessary to follow a science-based method indicating potential zones for groundwater storage. The LithoSFR Model is a systematic approach we built to create an indicative map with various categories for potential groundwater sites. It is based mainly on retrieved geospatial data from satellite images and from available thematic maps, plus borehole data. The geospatial data were systematically manipulated in a GIS with multi-criteria applications. The novelty of this model includes the empirical calculation of the level each controlling factor (i.e., weights and rates), as well as the LithoSFR Model, adopting new factors in its design. This study was applied on a representative Mediterranean region, i.e., Lebanon. Results showed that 44% of the studied region is characterized by a very high to high potentiality for groundwater storage, mainly in areas with fractured and karstified carbonate rocks. The obtained results from the produced map were compared with datasets which were surveyed from representative boreholes to identify the discharge in the dug boreholes, and then to compare them with the potential zones in the produced map The reliability of the produced map exceeded 87%, making it a significant tool to identify potential zones for groundwater investment.

Analisis Kebutuhan Fasilitas Pedestrian di Kawasan Stasiun

The Ampera LRT Station is located in the center of Palembang City and on the banks of the Musi River. This area is a center of community activity, with the presence of hospitals, offices, restaurants, hotels, and shopping centers. The existence of the Palembang LRT is intended to overcome congestion and accommodate the mobility needs of the community in Palembang, especially in the Ampera area. However, there are several issues related to pedestrian facilities in the Ampera LRT Station area, such as the misuse of sidewalk functions, the presence of many side barriers in the form of street vendors and on-street parking, as well as the lack of safe and comfortable crossing facilities for pedestrians, especially for people with disabilities. This study analyzes the pedestrian facility needs in the Ampera LRT Station area of Palembang. The method used in this study is the calculation of the level of service (LOS) based on the Indonesian Highway Capacity Manual (MKJI) 1997 and the empirical formula calculation of pedestrian conflicts based on the pedestrian flow and vehicle traffic flow (PV2) using quantitative data. The research results show that it is necessary to repair and add pedestrian facilities under the concept of walkability, such as providing sidewalks that can be used according to their function, providing crossing facilities such as pelicans with waiting platforms on Merdeka Street, Sudirman Street, and Tengkuruk Permai Street, while on Masjid Lama Street and Palembang Darussalam Street, zebra crossings or pedestrian platforms are needed. The results of this study are expected to be input for the Palembang City Government to improve the quality of pedestrian facilities in the Ampera LRT Station area so that it can support the station's function as a center of community activity and movement in the area.

Contagion and interdependencies between BRICS-plus Countries on the Markets of Commodities and Derivative Financial Instruments

Purpose: This study was started on the main macroeconomic data (2010-2019), coming from the countries of the BRICS-plus group. While a significant contribution of these emerging economies to global economic output has generally been observed, this has also been accompanied by persistent domestic imbalance. Design/Methodology/Approach: Regarding the model, we state and contextualize the (long-term) risk co-incidence of the set of macroeconomic variables for this coalition of countries. Particular attention was paid to a valuation, description and forecasting model based on the calculation of the Dynamic Conditional Correlation (DCC) in a Generalized AutoRegressive Conditional Heteroscedasticity (GARCH) process on the time series of credit default swaps (CDS). Findings: The empirical analysis and calculations carried out have verified the significance of the parameters and confirmed the conditional dynamic correlation between the economies of the Brics “expanded”, especially in the presence of shocks, which also involve mutual contagion (temporary increase in DCC) and even interdependence (increasing DCC leads to new, less unstable levels). Implications/Originality/Value: The research offers a look at the most current trends in terms of international economic balances and the entire global system, focusing on commodity markets, financial derivatives and the impacts of trade at the dawn of the new BRICS-plus coalition.

Research on damage assessment of buried pipelines with circular dent defects subjected to blast loading

In order to evaluate the damage characteristics of buried natural gas pipelines with circular dent defects subjected to blast loading, based on pressure–impulse damage theory, explosion experiment and numerical simulations were implemented to evaluate the damage of a natural gas with circular dent defects buried in soil under blast loading in this research. The ALE method was used to develop a coupled pipeline-soil simulation model using LS-DYNA software, and the validity of the established model was verified correctly compared with experimental results and empirical theory equations calculations. Furthermore, according to regulations in the Assessment and Management of Pipeline Dents (American Petroleum Institute Recommended Practice 1183), the effect with different circular dent defect diameter on the mechanical properties of natural gas was also investigated and analysed. The results showed that, under the blast loading, plastic deformation happened on the surfaces of the pipeline facing the explosive, and the high-stress zone appeared in the circumferential direction with 32.27°. The range of the high-stress zone firstly expanded along the axial direction of the pipelines and then along the circumferential direction. The larger diameter of the circular dent defects had, which resulted in a failure at the defects under the condition of the depth of the defects keeping constant. The effect of the size of defect diameter on the amount of pipeline deformation was further investigated, and the mathematical formula described the maximum plastic deformation with different defect diameter was established. Meanwhile, a finite element model of pipeline with a diameter of 457 mm was established for numerical analysis, which implied that the larger diameter of pipeline with the same defect had, the lower risk of pipeline in failure subjected to blast loading had. And through mathematical analysis and considering the feasibility of the actual situation, the curve described the maximum plastic deformation of the natural gas pipeline with three different defects varying in diameter were established respectively. In addition, a formula to express the relationship between pipeline defect diameter and maximum plastic deformation was established, which can effectively predict the critical plastic dent deformation of pipelines with different defect diameter subjected to blast loading. Besides, based on the pressure-pulse damage theory and with the damage assessment criterion of dent depth–dent length ratio of 0.072, the pressure–impulse diagrams of buried natural gas pipelines with defect diameters of 30 mm, 40 mm and 50 mm were defined, which can be used to predict the damage of pipelines with different defect diameters. Moreover, with the pressure–impulse damage evaluation curves, mathematical formula for the buried natural gas pipeline with the circular defects were established. Furthermore, the critical circular defect diameters with 30 mm was confirmed and the unique formula was also established, which could be effectively used to evaluate the safety of buried natural gas pipelines with the critical circular defects.

Why is the Omicron main protease of SARS-CoV-2 less stable than its wild-type counterpart? A crystallographic, biophysical, and theoretical study

During the continuing evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the Omicron variant of concern emerged in the second half of 2021 and has been dominant since November of that year. Along with its sublineages, it has maintained a prominent role ever since. The Nsp5 main protease (Mpro) of the Omicron virus is characterized by a single dominant mutation, P132H. Here we determined the X-ray crystal structures of the P132H mutant (or O-Mpro) as a free enzyme and in complex with the Mpro inhibitor, the alpha-ketoamide 13b-K, and we conducted enzymological, biophysical, as well as theoretical studies to characterize the O-Mpro. We found that O-Mpro has a similar overall structure and binding with 13b-K; however, it displays lower enzymatic activity and lower thermal stability compared to the WT-Mpro (with “WT” referring to the prototype strain). Intriguingly, the imidazole ring of His132 and the carboxylate plane of Glu240 are in a stacked configuration in the X-ray structures determined here. Empirical folding free energy calculations suggest that the O-Mpro dimer is destabilized relative to the WT-Mpro due to less favorable van der Waals interactions and backbone conformations in the individual protomers. All-atom continuous constant-pH molecular dynamics (MD) simulations reveal that His132 and Glu240 display coupled titration. At pH 7, His132 is predominantly neutral and in a stacked configuration with respect to Glu240 which is charged. In order to examine whether the Omicron mutation eases the emergence of further Mpro mutations, we also analyzed the P132H+T169S double mutant, which is characteristic of the BA.1.1.2 lineage. However, we found little evidence of a correlation between the two mutation sites.

High-throughput assessment of stability and mechanical properties of medium- and high-entropy carbides: Bridging empirical criteria and ab-initio calculations

This study assesses the effectiveness of empirical stability descriptors — the normalized geometric packing parameter, lattice size difference, electronegativities mismatch, and the convex hull analysis based on information on mutually dissolving components, and ab-initio calculated entropy forming ability (EFA) for high-throughput materials discovery in high-entropy ceramics. A sample containing 53,130 medium and high-entropy carbide combinations from the Materials Project database has been analyzed, comparing solid solutions selected based on empirical descriptors and EFA calculations. The suitability of various electronegativity scales is evaluated, while Automatic FLOW (AFLOW) partial occupation (AFLOW-POCC) and special quasirandom structures (SQS) calculations provide insights into enthalpies, bulk moduli, and lattice parameters. It is shown that local distortions play a role in determining the stability of high-entropy ceramics and estimated lattice parameters, Young’s modulus, fracture toughness, and Vickers hardness by computational and experimental approaches. Our analysis demonstrates the efficacy of density functional theory (DFT) approaches for high-throughput screening and highlights the need for the further exploration of the cocktail effect on high-entropy ceramics’ mechanical properties.

Cooling characteristics of thermochromic powder modified sand fog seal on asphalt pavement in summer high-temperature environment

Reversible optical response can occur in thermochromic materials with temperature changes, which has great potential in the field of pavement temperature regulation. The thermochromic sand fog seal (TP-SFS) was proposed in this study, which has the functions of pavement repair and temperature control. In this study, different types (red, blue, black) and contents (0 %, 2 %, 4 %, 6 %, and 8 %) of thermochromic powders (TP) were used to prepare TP-SFS. Secondly, the cooling characteristics of different TP-SFS was explored from the perspectives of temperature change rate, cooling temperature, and temperature gradient, based on the designed indoor and outdoor multi-cycle illumination test. Then, the prediction model of the outdoor cooling effect was proposed. In addition, the conservation and environmental benefits of different TP-SFS were calculated according to the empirical formula. It is found that after spraying TP-SFS, the heating rate of pavement decreases and the cooling rate increases. The cooling effect at 2 cm depth of the pavement sprayed with TP-SFS is the most significant, and the temperature gradient of the pavement is reduced. The cooling temperature of the pavement increases with the increase of TP content. In the outdoor environment, the more obvious cooling effect occurs as the process of pavement temperature increases and decreases. Additionally, the reliability of the designed indoor test is high, and the cooling effect of TP-SFS in outdoor environment can be well predicted according to the proposed model. The results of empirical formula calculation show that TP-SFS has a significant effect on delaying rutting development and alleviating urban heat island effect.

Harmonization of Trading Partners Between Indonesia–Italy: Empirical Calculations of Selected Agricultural Commodities

Initially, exports were perceived as the prestige and dignity of a nation. However, in terms of terminology, the essence of export flows is complementarity between countries, where each party has advantages, competition and excess production of a particular product to offer. The orientation of this study is to examine the relationship between tobacco exports, coffee exports, and wine exports to GDP growth in Italy–Indonesia. There are key variables which are divided into two case studies including tobacco export volume, FoB on tobacco exports, coffee export volume, FoB on coffee exports, green grape export volume, CIF on green grape exports, red wine export volume, CIF on red wine exports, GDP share of agriculture in Indonesia and Italy. The fundamental difference in wine exports from the two is that Indonesia uses green grapes and for Italy it uses red wine. The method is set through a panel data regression approach and samples for the 2013–2021. The econometric results explain that tobacco exports and coffee exports have a significant effect on the GDP share of agriculture in Indonesia–Italy. Likewise, CIF on exports of green grapes and red wines which have a significant effect on the GDP share of agriculture in both nations. These findings inspire more urgent implications for the topic of agricultural commodity exports and become an integrated whole.

Monitoring of fresh water consumption and energy needs for hot tap water heating in residential buildings

The study addresses discrepancies between design and measured values in building energy systems, focusing on water heating inside buildings in Central and Eastern Europe. Using data measured by the authors from 2010 to 2019 in Czech cities, a novel empirical calculation relationship for water flow estimation in apartment buildings is introduced, which is different from the outdated 1940 equation. The proposed calculation is refined and validated based on the measured values, allowing for accurate specification of daily and hourly water demands. The innovative approach is expected to result in tangible savings and a 10–20 % reduction in energy consumption for hot water heating, emphasising its significance for sustainable energy supply to buildings.

Multi-methodological analysis of hydrogen desorption from graphene

Chemisorption of hydrogen on graphene has been extensively investigated in last decades, but the reported values of over several eV, depending on different factors, such as the local structural environment, substrates or previously bound hydrogen.In this work, we combine Temperature-Programmed Desorption experiments with simulations using empirical reactive force fields and Density Functional Theory calculations. We observe that desorption occurs through processes with different activation energies, which we are able to identify by analyzing simulation data and post-processing experimental ones through a procedure based on Arrhenius fit with feedback. The result is the assignment of experimentally observed desorption peaks to different desorption processes, namely desorption from isolated sp3 H, or couples of H in conformation cis or trans, or edge sp3 or sp2 H.The protocol we outline is generally applicable and might be particularly useful in more complex cases with larger multiplicity of desorption peaks.

The Use of Multipliers in Assessing the Economic Effects of Digital Transformation of Territories (Case Study: Novosibirsk Region)

Development of the digital transformation of the state, the economy in general, business and society creates the need to quantify its results and assess the level of impact on the economy. The paper explains a methodological approach to calculating digital economy multipliers for territories based on the calculation of total income (direct and indirect) from digital activity. The multiplier measures the impact of the digital economy on macroeconomic and regional indicators, helps assess the extent of this impact and study its dynamics. The authors calculated digital economy multipliers for the Russian Federation and at the regional level (using the example of the Novosibirsk region) and estimated total digital sector income with a multiplier effect. The paper concludes with the contribution of digital transformation to the economic growth of the Russian Federation and the development of the Novosibirsk region about the multiplier dynamics and the ratio of direct and indirect effects in the total income of the digital sector. Rosstat data for 2017–2021 served as the information base for empirical calculations.

ET cool home: innovative educational activities on evapotranspiration and urban heat

Abstract. Teaching evapotranspiration (ET) in university courses often focuses on either oversimplified process descriptions or complex empirical calculations, both of which lack grounding in students' real-world experiences and prior knowledge. This calls for a more applied approach to teaching about ET that connects concepts to experience for improved educational outcomes. One such opportunity exists at the intersections between ET and heat in cities, where a growing majority of the world's population lives, including many of our students. In this work we describe an ET educational activity that integrates theory with practical design, taking advantage of the close link between ET processes and urban heat patterns. In a benchtop experiment, students measure ET variations across common land surfaces (e.g., asphalt, grass, and mulch) through water and energy balance approaches. The experiment is paired with an “urban heat tour” in the campus environment, facilitated by portable infrared cameras, offering firsthand observation of urban heat patterns. These two activities, together, provide context in which students can understand the difference in ET across various land covers, describe the relationship between ET and land surface temperatures, and explain the impacts of urban design on heat dynamics. The activities are adaptable to serve a diversity of student backgrounds and to different educational contexts, including public demonstrations and pre-university classrooms.

Study on failure modes and calculation method of the cast steel joint with branches in treelike structure

The treelike structure links members and transfers loads via its solitary cast steel joint with branches. Therefore, the joint’s bearing capacity significantly affects the treelike structure’s stability, security, and economics. This paper utilized experimental verification and numerical modeling to examine the mechanical behavior of cast-steel joints with branches in the treelike structure under various loading conditions. Then, researchers investigated the failure process and mechanism of joints, and the three most common failure modes were outlined. Furthermore, the researchers proposed the bearing capacity calculation formula based on the common failure modes. The results show that the three common failure modes of the cast-steel joints with branches under different loading conditions are the failure in the joint core area under the axial load, the failure in the main pipe compression side under eccentric load, and the failure in the compression side of the single branch pipe root when the single branch pipe is under the uneven load. The suggested empirical calculation method can serve as a reference point for similar engineering practices design.

Evaluation the Shielding Properties of Various Water Equivalent Materials Using Different Calculation Methods and Monte Carlo

In this study, the linear attenuation coefficients (LAC), mass attenuation coefficients (MAC), half-value layer (HVL), and mean free path (MFP) of various materials such as water equivalent, ABS, Presage, RMI457, RW3, SW557, Epoxy, A150, Rhizophora spp., and Nylon-12 have been calculated using the Monte Carlo simulation method, EpiXS, Phy-X/PSD, and XCOM. Additionally, the fast neutron effective removal cross sections (ΣR) have been calculated using the empirical calculation method, Phy-X/PSD, MRCsC program, experimental and MNCP5 with the help of fast neutron mass removal cross sections. Among all the materials studied, Nylon-12 has the highest ΣR value. The calculated values of HVL, MFP, LAC, and MAC reveal that RW3, Epoxy, and Presage are the best materials in terms of their shielding properties, respectively.

Fine- and hyperfine structure semi-empirical studies of atomic cobalt. Even-parity configurations system

We present the results of multiconfiguration semi–empirical calculations of the fine structure (fs) and the hyperfine structure (hfs) for the even-parity level system of atomic cobalt (Co I), using all available experimental data. These results were obtained using our proprietary software package designed for complex atom structure analysis. Through the iterative fine-structure calculation procedure, predictions of energy levels along with their Landé gJ factors and wave functions were obtained for each electronic state. Good agreement was achieved between the theoretical hyperfine structures and the experimental constants, which confirmed the validity of the propositions in the spectroscopic descriptions of observed Co I levels. For some levels no experimental hfs constants were known; in such cases these values are predicted.

Diverse high-pressure chemistry in Y-NH3BH3 and Y-paraffin oil systems.

The yttrium-hydrogen system has gained attention because of near-ambient temperature superconductivity reports in yttrium hydrides at high pressures. We conducted a study using synchrotron single-crystal x-ray diffraction (SCXRD) at 87 to 171 GPa, resulting in the discovery of known (two YH3 phases) and five previously unknown yttrium hydrides. These were synthesized in diamond anvil cells by laser heating yttrium with hydrogen-rich precursors-ammonia borane or paraffin oil. The arrangements of yttrium atoms in the crystal structures of new phases were determined on the basis of SCXRD, and the hydrogen content estimations based on empirical relations and ab initio calculations revealed the following compounds: Y3H11, Y2H9, Y4H23, Y13H75, and Y4H25. The study also uncovered a carbide (YC2) and two yttrium allotropes. Complex phase diversity, variable hydrogen content in yttrium hydrides, and their metallic nature, as revealed by ab initio calculations, underline the challenges in identifying superconducting phases and understanding electronic transitions in high-pressure synthesized materials.