Average Spacing Research Articles

Novel ultra-low NOx coal combustion technologies based on local microenvironment targeted regulation. Part 1. Selective oxygenation

Developing a novel high-efficiency coal combustion technology with ultra-low NOx emission is urgently needed to sustain the good ecological environment. Here, the targeted regulation of local microenvironment around fuel-N, such as functional groups, radicals, molecular configurations, and reaction atmosphere, is realized by the selective oxidation. The molecular configurations, including pore networks and microcrystalline structure in coal, are well characterized through synchrotron radiation-induced SAXS (small angle X-ray scattering) and WAXS (wide angle X-ray scattering) simultaneously. Furthermore, by combining density functional theory (DFT) and experiments, the effects of the local microenvironment on the nitrogen transformation and NO evolution during the thermal conversion are focused on. The results indicate that for the PPA oxidation, the H radicals attack the adjacent carbon to pyrrole/pyridine nitrogen, promoting the conversion of fuel-N to HCN. On the other hand, for the H2O2 oxidation, disrupting the π bond electron cloud by the CO and C = O on the ortho carbon of pyrrole/pyridine dominates the NH3 generation. Additionally, the increased La (average graphene layer extent), a3 (average interlayer spacing), σ3 (standard deviation of interlayer spacing) and σ1 (standard deviation of the first-neighbor distribution) induce massive smaller pores, promoting the generation of abundant reaction defects inside the particles. Importantly, the intensified adsorption on abundant active sites lead to the decreased HCN and increased NH3 evolution, which is adverse for the interaction between homogeneous and heterogeneous NO reduction. Interestingly, the PAA selective oxidation can reduce NO emission by 31.72 % - 34.30 % during the air combustion, which is far better than the H2O2 oxidation. Overall, the attack of free radicals on nitrogen-containing heterocycles promotes the conversion of fuel-N to HCN, the adsorption of which on char surfaces can further enhance the heterogeneous reduction in a lean oxygen atmosphere. The work here provides a novel route for developing high-efficiency and low-NOx combustion technologies.

Contribution of VLF electromagnetic survey to the investigation of Hessdalen lights (Norway)

Hessdalen valley in Norway is known for luminous phenomena suddenly and evenly appearing temporarily. Since several decades, these phenomena are observed by many witnesses, and they are sometimes traced by geophysical devices. The first appearance in modern times was reported in 1981 but systematic observations started during winter of 1984 when the Hessdalen project was launched. Later, Østfold University College led the project and yearly organized one to two field campaigns, with the objective to systematically record and investigate the phenomenon. Till that epoch, detailed tectonics, fault systems and superficial conductive structures remained unknown. Therefore, during the last years, VLF surveys have been performed in Hessdalen valley as part of six geophysical field campaigns which sometimes also included Total Magnetic Field and Self Potential spatial ground measurements. VLF measurements have been carried out on a 20 m average spacing along many traces totaling to100 km length. The entire covered area was about 100 km2.In this paper, we focus on the results of the VLF measurements. Several conductive zones have been found. They are mainly related to mineral deposits (mainly sulfides). The trace at the ground surface of these conductive zones could suggest that they draw an ellipse of 6 by12 km, related to the shape of the gabbro intrusion present in the area and oriented in the SW-NE direction. The results combined with other geophysical data contribute to better understand how the near surface structures (depth less than a few hundred meters) could supply the generation of the so-called Hessdalen lights (‘HL’) and explain why these lights appear inside this valley. The particular geological structure detected in Hessdalen valley may encourage similar campaigns in other areas where similar phenomena are observed.

Influence of spatial coherence on phonon transmission across aperiodically arranged interfaces

In this study, we employ the atomistic wave-packet method to directly simulate coherent phonon transport and scattering dynamics in an aperiodic superlattice structure with aperiodically arranged interfaces. Our investigation reveals that interference dynamics, contingent upon the relative magnitudes of phonon wavelength, spatial coherence length, and average interface spacing, profoundly influence transmission spectra and mode-conversion behavior. Particularly, longer-wavelength phonons possessing larger coherence lengths exhibit more pronounced destructive interference and mode-conversion, leading to generally lower transmission. The insights gained into coherent phonon wave physics from this study can significantly augment the analysis and design of phononic devices.

Space Efficiency in Timber Office Buildings

Timber offices indicate a growing field, principally thanks to their potential to offer noteworthy ecological and financial gains over their entire life. Like many other building types, space efficiency is a crucial design parameter in timber structures to ensure a project's feasibility. This factor is especially significant in office buildings, where maximizing rental income reflects effective planning. Currently, there is a lack of exhaustive inquiry providing a thorough insight of space efficiency in modern timber office buildings. This study fills this gap in the literature by collecting data from 33 buildings through literature reviews and case study method to investigate space efficiency with the key architectural and structural factors that influence it. The results showed that: (i) central cores stood out as the prevailing core layouts, while peripheral arrangements were noted as alternative preferences. Prismatic shapes emerged as the most favored options; (ii) timber was extensively used as a primary building material, closely followed by combinations of timber and concrete. Load-bearing systems mainly relied on shear walled frames and configurations; (iii) average space utilization across examined cases was 88%, with variances ranging from 75% to 95% among different instances; (iv) average ratio of core area to GFA was 10%, showing variations between 4% and 19% across various scenarios; and (v) there were no substantial variances noted in the effect of different core planning strategies on spatial efficiency. Similar conclusions were drawn regarding building forms and structural materials. Our paper will assist in crafting design principles customized for diverse stakeholders, including architectural designers of timber offices.

Microstructural Evolution of Highly Aligned Discontinuous Fiber Composites during Longitudinal Extension in Forming

The longitudinal extensional viscosity of a highly aligned discontinuous fiber (ADF) thermoplastic matrix composite is investigated to develop a model and validate microstructural evolutionary mechanisms. Samples stretched at constant temperature and strain rate are shown to exhibit a strain softening behavior. X-ray CT analysis and optical micrographs show that the composite microstructure deconsolidates before forming and evolves with deformation. The conventional unit cell micromechanical model includes the effects of matrix viscosity, fiber aspect ratio and fiber volume fraction. This model is modified to include the stiffening effect of fiber spacing variability, and the softening effects of porosity and decreasing fiber overlap length with elongation. Calibration of the model reveals that matrix shear strain rate is an order of magnitude higher than previously predicted due to local fiber spacing. This effect is captured by a fiber spacing variability parameter which scales average spacing down by an order of magnitude. The observed strain softening behavior is described and a combinations of fiber overlap length reduction and local fiber spacing increase.

Mining the GALAH Data. I. Study of Five Super Lithium-rich Metal-poor Giants

Abstract The presence of a large amount of Li in giants is still a mystery. Most of the super Li-rich (SLR) giants reported in recent studies are in the solar metallicity regime. Here, we study the five metal-poor SLRs from the Galactic Archeology with HERMES Data Release 3, with their [Fe/H] ranging from −1.35 to −2.38 with lithium abundance of A(Li) ≥ 3.4 dex. The asteroseismic analysis reveals that none are on the red giant branch. The average period spacing (ΔP ) values indicate giants are in the core He-burning phase. All of them are low-mass giants (M < 1.5 M ⊙). Their location in the Hertzsprung–Russell diagram suggests one of them is in the red clump (RC) phase, and interestingly, the other four are much brighter and coincide with the early asymptotic giant branch phase. The analysis of the abundance reveals that C, O, Na, Ba, and Eu are normal in giants of respective metallicities and evolutionary phases. Further, we did not find any strong evidence of the presence of dust in the form of infrared excess or binarity from the available radial velocity data. We discuss a few scenarios for the existence of SLRs at higher luminosity, including past merger events. Our findings will help in understanding the production and evolution of Li among giants, in particular, during the RC phase and the post-RC phase.

Evaluation of echocardiography and computed tomography characteristics related to aortic valve replacement technique through the right anterior thoracotomy at the 2nd intercostal space

Objective: evaluate echocardiographic and computed tomography characteristics related to minimally invasive aortic valve replacement technique through the right anterior thoracotomy at the 2nd intercostal space. Methods: study on 74 patients undergoing aortic valve replacement surgery through the right anterior thoracotomy at the 2nd intercostal space at Hanoi Heart Hospital and 108 Military Central Hospital, from October 2019 to December 2022. Patients underwent preoperative echocardiography and multiple slices computed tomography to assess the lessons of aortic valve, valve annulus diameter, and intercostal space width. Results: The ratio of aortic valve stenosis is 55.4%, stenosis combined with regurgitation is 31.1%, and aortic regurgitation is 13.5%. The average valve annulus diameter on computed tomography scans is 26.5 ± 3.1 mm (smallest 20; largest 36); average 2nd intercostal space width 18.1 ± 3.1 mm (smallest 11; largest 25). Valve annulus diameter measured by computed tomography correlates closely with actual prosthetic valve size (r = 0.54, p < 0.001); measured by echocardiography had a weak correlation and not statistically significant. The prosthetic valve size to be replaced is smaller than the valve annulus diameter measured on computed tomography, with an average of 4.8 ± 2.7 mm in aortic valve stenosis, 5.7 ± 2.0 mm in combined stenosis and regurgitation, and 7.2 ± 2.9 mm in aortic regurgitation, in which the difference between valve stenosis and regurgitation is statistically significant (p = 0.01). Conclusions: Minimally invasive aortic valve replacement technique through the 2nd intercostal space right thoracotomy, with cutting the 3rd rib, is suitable for Vietnamese anatomy. Valve annulus diameter measured by computed tomography has a good linear correlation and can be a predictor for prosthetic valve size before surgery.

Realized dynamic effect of retrofits on energy consumption in Soviet-era multi-apartment buildings

Retrofit programs for old and highly energy-inefficient housing stock from the Soviet era are widely believed to offer a rare win-win opportunity for mitigating climate change and addressing acute energy poverty issues in Eastern European urban neighborhoods. However, despite government subsidies and a push for greater energy efficiency, many people do not undertake retrofits. This raises the question: do these retrofits truly deliver the promised returns? This paper aims to examine the effects of retrofit programs on old Soviet-era multi-apartment buildings' realized dynamic energy savings in Lithuania by analyzing monthly energy bills. Our findings suggest that retrofits are associated with a 50% to 59% reduction in average space heating consumption across various post-retrofit periods. Additionally, retrofits have a short-term effect on electricity savings of 3% to 3.6%. However, our cost-benefit analysis indicates that the energy savings were not sufficiently large to cover the initial investment costs.

Enhanced Fe(OH)2-driven reductive Dechlorination via shortened Fe-O bonds and colloidal medium

Fe2+ is usually adsorbed to the surface of iron-bearing clay, and iron (hydr)oxide in groundwater. However, the reductive activity of Fe(OH)2, a prevalent intermediate during the transformation of Fe2+, remains unclear. In this study, high-purity Fe(OH)2 was synthesized and tested for its activity in the degradation of carbon tetrachloride (CT). XRD data confirm that the synthesized material is a pure Fe(OH)2 crystal, exhibiting sharp peaks of (001) and (100) facets. Zeta potential analysis confirms that the off-white Fe(OH)2 is a colloidal suspension with a positive charge of ∼+35-50 mV. FTIR spectra reveal the formation of a coordination compound Fe2+ with OH−/OD−, derived from NaOH/OD. SEM and HRTEM results demonstrate that the Fe(OH)2 crystal has a regular octahedral structure with a size of ∼30-70 nm and average lattice spacings of 2.58 Å. Mössbauer spectrum verifies that the Fe2+ in Fe(OH)2/Fe(OD)2 is hexacoordinated with six Fe-O bonds. XAFS data demonstrate that the Fe-O bonds become shorter as the OH−:Fe(II) ratios increase. DFT results indicate that the (100) crystal face of Fe(OH)2 more readily transfers electrons to CT. In addition to being adsorbed to iron compounds, structural Fe2+ compounds such as Fe(OH)2 could also accelerate the electron transfer from Fe2+ to CT through shortened Fe-O bonds. The rate constant of CT reduction by Fe(OH)2 is as high as 0.794 min−1 when the OH−:Fe(II) ratio is 2.5 in water. This study aims to enhance our understanding of the structure-reactivity relationship of Fe2+ compounds in groundwater, particularly in relation to electron transfer mechanisms.

How much is US Office Building Space Reduced per Teleworker?

As office workers shift to telework, office building space requirements should decrease, but this relationship has not been empirically studied. We construct a dataset describing historical office building space, number of office workers, and number of teleworkers from 2003-2019 in the US, and use linear regression to estimate the effect of telework on office building space. The results show that the average office building space required for an additional office worker and teleworker is 32 and 18 square meters (340 and 191 square feet), respectively, suggesting an average 44% reduction in office building space when an office worker transitions to telework.

Flexural behaviour of post-tensioned precast beams manufactured with basalt-fibre-reinforced recycled concrete–conventional concrete

To promote the sustainable development of the ecological environment, facilitate the recycling of recycled concrete and explore efficient approaches to enhance the performance of structural components, this study proposes a post-tensioned precast beam model manufactured with basalt-fiber-reinforced recycled concrete–conventional concrete. Flexural performance tests were conducted on 12 beams with different concrete strength grades (C40, C50, C60), basalt-fiber-reinforced recycled concrete layer thicknesses (200 mm, 250 mm, 300 mm), and basalt fiber volume fractions (0%, 0.1%, 0.2%). The results show that the incorporation of basalt fiber can effectively inhibit crack development, and improve the stiffness and flexural strength of components. Through theoretical analysis, the factors affecting the ultimate stress formula for high-strength prestressing steel strands are attributed to the comprehensive reinforcement index and prestressed reinforcement index, thereby obtaining a flexural strength formula. Coefficients describing the influences of basalt fiber and recycled coarse aggregate were introduced and combined with average crack spacing and width measurements to derive a post-tensioned precast beam model of average crack spacing and width. Based on the derived calculation model, the average deviation between the tested and calculated results of the ultimate bending moment is less than 6%, and the average deviation between the tested and calculated results of the average crack width is less than 9%. The proposed model has good prediction accuracy for evaluating the flexural strength and average crack width, which provides a theoretical basis for assessing the flexural performance of composite beams.

The microstructure and precipitated phase dependence of plastic deformation and fracture mechanism in repaired IN718 alloy by directed energy deposition

This work studied microstructural evolution, precipitate behaviors, and micro-hardness distribution along the built direction of directed energy deposited IN718 alloy. In combination with digital image correlation and crystallographic orientation analysis, the plastic deformation and fracture mechanisms of coarse columnar grains were explored in detail. The columnar grains in the deposition zone (DZ) grow along the <001> direction in the crystallography and gradually widen with increasing built height. The misorientation angle per unit length within individual columnar grains first decreases and then slows down to ~ 0.07 °/μm when the deposition height is ~ 1.8mm. The micro-hardness in the DZ is gradually decreased along the built direction, which may be due to the increasing average columnar grain width and primary dendrite arm spacing, as well as reducing the volume fraction of the γ'' + γ' phases. During the uniaxial tensile loading, most plastic deformation always occurs in the DZ irrespective of the lowest hardness in the heat-affected zone (HAZ). The nucleation of microvoids is ascribed to the granular Laves phase debonding from the γ matrix. The number of microvoids gradually decreases with increasing distance from the fracture surface, which may be attributed to the strain-controlled nucleation of microvoids. EBSD results substantiated that the columnar grains near the fracture surface occur to severe lattice rotation, leading to the Kernel misorientation angle distribution in each grain interior increasing to about 1° ~ 4°.

Natural compound plumbagin based inhibition of hIAPP revealed by Markov state models based on MD data along with experimental validations.

Human islet amyloid polypeptide (amylin or hIAPP) is a 37 residue hormone co-secreted with insulin from β cells of the pancreas. In patients suffering from type-2 diabetes, amylin self-assembles into amyloid fibrils, ultimately leading to the death of the pancreatic cells. However, a research gap exists in preventing and treating such amyloidosis. Plumbagin, a natural compound, has previously been demonstrated to have inhibitory potential against insulin amyloidosis. Our investigation unveils collapsible regions within hIAPP that, upon collapse, facilitates hydrophobic and pi-pi interactions, ultimately leading to aggregation. Intriguingly plumbagin exhibits the ability to bind these specific collapsible regions, thereby impeding the aforementioned interactions that would otherwise drive hIAPP aggregation. We have used atomistic molecular dynamics approach to determine secondary structural changes. MSM shows metastable states forming native like hIAPP structure in presence of PGN. Our in silico results concur with in vitro results. The ThT assay revealed a striking 50% decrease in fluorescence intensity at a 1:1 ratio of hIAPP to Plumbagin. This finding suggests a significant inhibition of amyloid fibril formation by plumbagin, as ThT fluorescence directly correlates with the presence of these fibrils. Further TEM images revealed disappearance of hIAPP fibrils in plumbagin pre-treated hIAPP samples. Also, we have shown that plumbagin disrupts the intermolecular hydrogen bonding in hIAPP fibrils leading to an increase in the average beta strand spacing, thereby causing disaggregation of pre-formed fibrils demonstrating overall disruption of the aggregation machinery of hIAPP. Our work is the first to report a detailed atomistic simulation of 22 μs for hIAPP. Overall, our studies put plumbagin as a potential candidate for both preventive and therapeutic candidate for hIAPP amyloidosis.

A high-density genetic linkage map and QTL identification for growth traits in dusky kob (Argyrosomus japonicus)

High-density genetic linkage maps provide a foundational genomic resource for quantitative trait locus (QTL) mapping, candidate gene localisation, and comparative genomic analysis. Data from such studies, in turn, can be incorporated into marker or genomics assisted selective breeding strategies for increased efficiency of aquaculture production. This study aimed to construct the first high-density genetic linkage map for dusky kob (Argyrosomus japonicus) a commercially important marine finfish in Asia, Australia, and South Africa. Using 2b-restriction site-associated DNA (2b-RAD) sequencing for genome-wide single nucleotide polymorphism (SNP) genotyping, in three full-sib F1 families (Family 1, n = 69 offspring; Family 2, n = 73 offspring; and Family 3, n = 70 offspring), led to the discovery and genotyping of 22,789 SNPs. Among these, 3992 quality filtered and informative SNPs were mapped to 24 linkage groups (LGs), aligning with the species' proposed haploid chromosome number. The total integrated genetic map spanned a length of 2550 cM with an average marker spacing of 0.68 cM, achieving a genome coverage of 98.61%. Male and female specific maps highlighted differential map lengths and recombination rates between the sexes, with the female map slightly longer and a lower recombination frequency than for the male. QTL analysis for growth-related traits, weight (W), standard length (sL), and Fulton's condition factor (K), identified a total of 25 QTLs of which five QTLs were found to be consistently shared across the traits. Collectively, these shared QTLs explained a substantial proportion of the phenotypic variance, accounting for between 9.30 and 19.30% of the observed variation, suggesting potential major genes for growth. These QTL regions led to the discovery of 65 potential candidate genes, including 11 genes that were specifically located within the shared QTLs. These genes were linked to essential biological processes, including metabolism, immunity, stress response, development, and vascular function. The establishment of this high-density genetic linkage map represents an important genomic resource for comprehending the genetic determinants of economically important traits in A. japonicus, with implications for advancing and optimising ongoing marker-assisted selection (MAS) initiatives in the species.

Minimal but potentially clinically relevant anteroinferior position of the humeral head following traumatic anterior shoulder dislocations: A 3D-CT analysis.

In unstable shoulders, excessive anteroinferior position of the humeral head relative to the glenoid can lead to a dislocation. Measuring humeral head position could therefore be valuable in quantifying shoulder laxity. The aim of this study was to measure (1) position of the humeral head relative to the glenoid and (2) joint space thickness during passive motion in unstable shoulders caused by traumatic anterior dislocations and in contralateral uninjured shoulders. A prospective cross-sectional CT-study was performed in patients with unilateral anterior shoulder instability. Patients underwent CT scanning of both injured and uninjured side in supine position (0° abduction and 0° external rotation) and in 60°, 90°, and 120° of abduction with 90° of external rotation without an external load. Subsequently, 3D virtual models were created of the humerus and the scapula to create a glenoid coordinate system to identify poster-anterior, inferior-superior, and lateral-medial position of the humeral head relative to the glenoid. Joint space thickness was defined as the average distance between the subchondral bone surfaces of the humeral head and glenoid. Fifteen consecutive patients were included. In supine position, the humeral head was positioned more anteriorly (p = 0.004), inferiorly (p = 0.019), and laterally (p = 0.021) in the injured compared to the uninjured shoulder. No differences were observed in any of the other positions. A joint-space thickness map, showing the bone-to-bone distances, identified the Hill-Sachs lesion footprint on the glenoid surface in external rotation and abduction, but no differences on average joint space thickness were observed in any position.

First-principles study on the effects of fast neutron irradiation and fast neutron irradiation under the external electric field on carbon-based material AB bilayer graphene

The irradiation damage mechanism of fast neutron irradiation and the fast neutron irradiation under the practical application of an additional electric field on carbon-based material AB bilayer graphene is not yet clear. This paper systematically investigates the impact of fast neutron irradiation and fast neutron irradiation under the practical application of the additional electric field (−0.2 V/Å) on carbon-based material AB bilayer graphene through density functional theory and molecular dynamics simulations. The research results indicate that the changes in the configuration of AB bilayer graphene and the appearance of surface ripples induced by fast neutron irradiation are the two main reasons for the alterations in the system's microstructure, band structure, Young's modulus, and optical properties, which may lead to performance degradation and damage of carbon-based devices. The further variation in the average interlayer spacing of the system under external electric field irradiation leads to the diversity of the system configuration, which ultimately leads to the diversity of the band structure of the system. The uncertainty in the type and width of the bandgap in AB bilayer graphene under fast neutron irradiation with an external electric field may be one of the reasons for the performance degradation and permanent damage of carbon based devices in practical applications. In the fast neutron irradiation environment, the precise control of the bandgap of AB bilayer graphene by an applied electric field will fail.

Flexural Behavior of Alkali-Activated Ultra-High-Performance Geopolymer Concrete Beams

Ultra-high-performance geopolymer concrete (UHPGC) emerges as a sustainable and cost-effective alternative to Portland cement-based UHPC, offering similar mechanical properties while significantly reducing carbon footprint and energy consumption. Research on UHPGC components is extremely scarce. This study focuses on the flexural and crack behavior of UHPGC beams with different steel fiber contents and longitudinal reinforcement ratios. Five UHPGC beams were tested under four-point bending. The test results were evaluated in terms of the failure mode, load–deflection relationship, flexural capacity, ductility, average crack spacing, and short-term flexural stiffness. The results show that all the UHPGC beams failed due to crack localization. Increases in the reinforcement ratio and steel fiber content had favorable effects on the flexural capacity and flexural stiffness. When the reinforcement ratio increased from 1.18% to 2.32%, the flexural capacity and flexural stiffness increased by 60.5% and 12.3%, respectively. As the steel fiber content increased from 1.5% to 2.5%, the flexural capacity and flexural stiffness increased by 4.7% and 4.4%, respectively. Furthermore, the flexural capacity, flexural stiffness, and crack spacing of the UHPGC beams were evaluated using existing methods. The results indicate that the existing methods can effectively predict flexural capacity and flexural stiffness in UHPGC beams but overestimate crack spacing. This study will provide a reference for the structural design of UHPGC.

Impact of external female urinary catheter use on urine chemistry test results

We aimed to evaluate how urine chemistry tests are impacted by collection using a female external urinary catheter employing wicking and suction, to assess this catheter's potential as an alternative to transurethral catheters for collecting urine samples from incontinent patients. We obtained 50 random 40mL refrigerated urine specimens from excess volume submitted to the Michigan Medicine Biochemical Laboratory. Specimens were split into a 10mL "control" sample simulating voided urine, and a 30mL paired "wicked" sample applied dropwise to and collected from a fresh PureWick system simulating collection from an incontinent patient. Each sample pair was tested for glucose, sodium, potassium, creatinine, urea, total protein, and derived ratios of sodium/creatinine, urea/creatinine, and protein/creatinine, then compared using Pearson correlation coefficients. Wicking materials were imaged via absorption contrast tomography on a laboratory X-ray microscope, to study the structure through which urine passes. Control and wicked urine samples had very similar results for all chemical tests evaluated: strong Pearson correlation coefficients ranging from 0.955 (potassium) to 0.997 (glucose). Microscopic assessment of the amorphous wicking materials demonstrated an average pore spacing of 95.38µm. Common urine chemistry tests were unaltered by collection using the PureWick female external catheter system. This external device can be used to collect urine for chemistry tests as an alternative to transurethral catheters.

Dynamic feedback algorithm based on spatial corner fitness for solving the three-dimensional multiple bin-size bin packing problem

AbstractTo improve cargo loading efficiency and achieve diverse needs of companies for the loading process, this paper innovatively establishes a multiple objective mixed integer programming model for the three-dimensional multiple bin-size bin packing problem (3D-MBSBPP). The model is designed to maximize container space utilization rate and cargo load balance, minimize container usage costs, and incorporates some practical constraints. On this basis, we propose a novel dynamic feedback algorithm based on spatial corner fitness (SCF_DFA) to solve this model, which consists of three stages. Specifically, Stage 1 employs a heuristic algorithm based on spatial corner fitness to optimize the search of the remaining spaces. Stage 2 employs a container type selection algorithm to dynamically adjust and optimize container types. Stage 3 uses an improved genetic algorithm to improve the quality of the solutions of the first two stages. We demonstrate the effectiveness of the proposed algorithm through comparative experiments on benchmark instances, and apply it to solve the real-life instances for the 3D-MBSBPP. The results show that the proposed algorithm can make the average container space utilization rate reach 85.38%, which is 1.48% higher than that of baseline method, while the loading results obtained are more balanced, indicating the advantages of the SCF_DFA in solving 3D-MBSBPP. Furthermore, we conduct ablation experiments to confirm the effectiveness of each component within the algorithm.

Formation of nano martensite grain with specific angle grain boundary during the drawing process of 316L stainless steel

The evolution of the deformation-induced martensite in the drawn 316L stainless steel and its effect on mechanical performance are examined. Both the yield strength and ultimate tensile strength of the 316L wire reach over 2.3 GPa at a drawing strain of 3.44. The deformation production of the wire during the drawing process is dislocation, twin and finally, deformation-induced α′-martensite. The neighboring misorientation between α′-martensite shows a preferential distribution around 60° due to variant selection limited by a double K–S orientation relationship. This preferential misorientation distribution around ∼60° is stable during the drawing process, and the α′-martensite has been refined to possess an average boundary spacing of ∼50 nm at a strain of 3.44.