Nature Of State Research Articles

Kinetics of soil re-acidification under no-tillage system

The rate and amount of Al3+ released from re-solubilization of the Al-containing polymers and minerals due to the increase in proton activity in the soil solution in subtropical regions is scarce in the literature. The objective of the present study was to track the Al3+ reappearance following its neutralization during the switch from a conventional tillage system to a no-till (NT) system. For this purpose, we evaluated a long-term lime experiment under NT on a subtropical Ultisol. The treatments included varying lime rates, with different historic of lime reapplication. Soil samples were taken at the 0–5, 5–10, and 10–15 cm depth in 1988, 1994, 1995, 1996, 2001, 2003, 2006, 2012, and 2022. The re-solubilization of Al-containing soil polymers and minerals in the 0–15 cm soil layer proceeds slowly in the first 10 years; afterwards, the rate and amount of Al3+ released increased. However, regardless of the lime treatment, the soil never returns its natural acidic state, even after 34 years of the first liming operation. A decrease in the intensity of reappearance of exchangeable Al3+ in the soil profile is clearly observed, compared to the treatment without reapplication of surface lime. We have observed that it takes 7–9 years for 10% of the effective cation exchange capacity to be occupied by Al3+ if limestone is not reapplied on the soil surface; if underdoses are reapplied this level can be maintained for 13–15 years. Furthermore, if larger and more frequent lime doses are used, a low Al3+ saturation (<10%) can be maintained permanently. These findings emphasize the importance of an appropriate liming process at the start of NT, followed with surface limestone reapplication, to ensure a very low Al3+ saturation over a long period of time in the 0–15 cm soil layer.

Reconstructing long-term natural flows by ensemble machine learning

Large-scale human activities have caused significant disruption to the natural flow regime of rivers worldwide, leading to substantial deviations from river flows’ natural state. The natural hydrological regime of rivers holds great significance for the conservation and management of riverine ecosystems, which relies on the accurate reconstruction of natural river flows. However, the application of existing high spatiotemporal resolution large-scale natural flow datasets at the regional scale has not been adequately assessed, thereby limiting their regional-scale utility. In this study, utilizing global reanalysis datasets and observation data, in combination with ensemble machine learning models, we constructed long-term natural flow time series for inflows into the Pearl River Delta and evaluated the performance of these reconstructed inflows based on observed flow records during undisturbed periods. The reconstruction shows that the ensemble model, the AutoGluon model, indicates the best performance when compared with other machine learning models and outperforms the existing publicly available large-scale datasets in terms of evaluation metrics for the corresponding natural flows. The results of Indicator of Hydrologic Alteration and Range of Variability Analysis (IHA-RVA) indicate that climate variability, reservoir regulation and human activities have significantly altered the natural flow regime of the Pearl River Delta. Specifically, human activities generally tend to smooth natural flow variability in the Pearl River Delta. This research is expected to provide an efficient and reliable method for reconstructing natural flows and offers guidance for water resource management and ecosystem conservation.

Analysis of Factors Affecting the Choice of Implant-based or Autologous Fat Grafting Breast Augmentation: A Retrospective Study.

Breast augmentation mainly includes implant-based and autologous fat grafting augmentation. Choosing the right surgical method for the patient is particularly important. However, an analysis of the factors that may affect the choice of surgical methods among patients has not yet been performed. In this study, the authors sought to identify the factors that influence the choice of surgical methods for women who receive implant or autologous fat grafting breast augmentation. A total of 192 female patients with micromastia who were hospitalized for breast augmentation from June 2018 to June 2021 were included in the study. The enrolled patients were divided into the implant group (n=92) and the fat group (n=100). Univariate and multivariate analyses were then performed on the data. In the univariate analysis, there were statistical differences between the implant and fat group in weight, BMI, marital status, occupation, bilateral midsternal line-nipple distance difference, bilateral nipple-inframammary fold distance difference in the natural state, and others ( P <0.05). In the final logistic binary regression analysis, the statistically different factors included the acceptable number of operations, chest circumference through the armpit, and chest circumference through the inframammary fold ( P <0.05). There were several factors, such as acceptable numbers of operations, chest circumference through the armpit, and chest circumference through the inframammary fold, may affect the choice of breast augmentation surgery method for Chinese female patients. Level-III, retrospective cohort study.

Can limiting global temperature rise to below 2°C warming prevent the emergence of unprecedented drought?

In the context of anthropogenic global warming, unprecedented drought is expected to emerge over some regions where drought conditions exceed the variation range of the natural state. However, it is still unclear how the 1.5 °C and 2 °C warming targets proposed by the Paris Agreement will delay or even prevent the emergence of unprecedented drought. To illustrate the benefits of the two warming targets for mitigating drought conditions, this study investigated the time of emergence (TOE) of unprecedented meteorological drought as indicated by the Standardized Precipitation Evapotranspiration Index (SPEI) using the Coupled Model Intercomparison Project Phase 6 (CMIP6) model ensembles forced by 4 Shared Socioeconomic Pathways (SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5). In particular, the pattern of TOE is explored for 4 pseudo warming scenarios under which global mean surface temperature (GMST) increases by 1.5 °C, 2 °C, 3 °C, and 4 °C above pre-industrial levels, respectively. The results suggested that: (1) Under the 1.5 °C and 2 °C warming scenarios, unprecedented meteorological drought is anticipated to emerge over southern Africa, Arabian Peninsula, central Asia, Mongolia, southwestern South America, and western and eastern Australia. (2) Under the 3 °C and 4 °C warming scenarios, unprecedented meteorological drought will expand to western North America, the Amazon, and the Mediterranean. (3) The comparisons with the exposure under the 3 °C and 4 °C warming scenarios show that the aspirational 1.5 °C and 2 °C Paris Agreement warming targets can prevent at least 0.6 × 107 km2 of land area, 1.4 × 108 people, and 0.6 × 106 km2 of cropland area from suffering the emergence of unprecedented meteorological drought.

Soil improvement withsugarcane bagasse ash : technical-economic viabilityfor tertiary roads

Introduction: Economic evaluation of soil subgrade improvement using sugarcane bagasse ash case study: Propal Road - La Cabaña Sugar Mill”, developed at the Pontifical Javeriana University of Cali in 2022. Problem: Tertiary roads in Colombia are essential for mobility in rural areas and for the sugar industry, which generates waste such as sugarcane bagasse ash (SGBA). Objective: To present the results of the economic and technical feasibility study of using sugarcane bagasse ash for soil improvement in tertiary roads. Methodology: Characterization tests of natural soil state and modified Proctor, expansion index, CBR, and unconfined compression for stabilized soils at percentages of 5, 10, 15, and 20% of SGBA are carried out. Results: The mechanical properties of the soil improve with additions of ash between 5% and 15%; however, the utilization of 15% of SGBA is proposed to favor the disposal of a significant volume of this waste. Conclusion: The technical and economic feasibility of using SGBA as a promising solution to improve tertiary roads in Colombia is demonstrated. Originality: Viability of implementing sugarcane bagasse ash on rural roads of sugar mills and agricultural areas with production of this type of waste. Limitations: Similar studies should be carried out for each region to confirm the appropriate percentage for subgrade stabilization using SGBA.

Revealing the Effect of Typhoons on the Stability of Residual Soil Slope by Wind Tunnel Test

Typhoon-induced slope failure is one of the most important geological hazards in coastal areas. However, the specific influence of typhoons on the stability of residual soil slopes still remains an open issue. In this study, the Feiyunjiang catchment in Zhejiang Province of SE China was chosen as the study area, and a downscaling physical model of residual soil slopes in the region was used to carry out the wind tunnel test. Our aim was to answer the question, How does the vegetation on the slope and slope stability respond during a typhoon event? For this purpose, multiple aspects were monitored and observed under four different wind speeds (8.3 m/s, 10.3 m/s, 13.3 m/s, and 17 m/s), including vegetation damage on the slope, macrocracks on the slope surface, wind pressure, wind load, permeability coefficient of the soil layer, and slope stability. The results showed that the plants on the slope could restore to their original states when the wind speeds ranged from 8.3 m/s to 13.3 m/s, but were damaged to the point of toppling when the wind speed increased to 17 m/s. Meanwhile, evident cracks were observed on the ground under this condition, which caused a sharp increase in the soil permeability coefficient, from 1.06 × 10−5 m/s to 6.06 × 10−4 m/s. The monitored wind pressures were larger at the canopy than that at the trunk for most of the trees, and generally larger at the crown of the slope compared with the toe of the slope. Regarding the wind load to the slope ground, the total value increased significantly, from 35.4 N under a wind speed of 8.3 m/s to 166.5 N under a wind speed of 17 m/s. However, the wind load presented different vector directions at different sections of the slope. The quantitative assessment of slope stability considering the wind load effect revealed that the safety factor decreased by 0.123 and 0.1 under the natural state and saturated state, respectively, from no wind to a 17 m/s strong wind. Overall, the present results explained the mechanism of slope failure during typhoon events, which provided theoretical reference for revealing the characteristics of residual soil slope stability under typhoon conditions.

Redesigning the kinetics of lysozyme amyloid aggregation by cephalosporin molecules.

In lysozyme amyloidosis, fibrillar aggregates of lysozyme are associated with severe renal, hepatic, and gastrointestinal manifestations, with no definite therapy. Current drugs are now being tested in amyloidosis clinical trials as aggregation inhibitors to mitigate disease progression. The tetracycline group among antimicrobials in use is in phase II of clinical trials, whereas some macrolides and cephalosporins have shown neuroprotection. In the present study, two cephalosporins, ceftazidime (CZD) and cefotaxime (CXM), and a glycopeptide, vancomycin (VNC), are evaluated for inhibition of amyloid aggregation of hen egg white lysozyme (HEWL) under two conditions (i) 4 M guanidine hydrochloride (GuHCl) at pH 6.5 and 37° C, (ii) At pH 1.5 and 65 °C. Fluorescence quench titration and molecular docking methods report that CZD, CXM, and VNC interact more strongly with the partially folded intermediates (PFI) in comparison to the protein's natural state (N). However, only CZD and CXM proficiently inhibit the aggregation. Transmission electron microscopy, tinctorial assessments, and aggregation kinetics all support oligomer-level inhibition. Transition structures in CZD-HEWL and CXM-HEWL aggregation are shown by circular dichroism (CD). On the other hand, kinetic variables and soluble fraction assays point to a localized association of monomers. Intrinsic fluorescence (IF),1-Anilino 8-naphthalene sulphonic acid, and CD demonstrate structural and conformational modifications redesigning the PFI. GuHCl-induced unfolding and differential scanning fluorimetry suggested that the PFI monomers bound to CZD and CXM exhibited partial stability. Our results present two mechanisms that function in both solution conditions, creating a novel avenue for the screening of putative inhibitors for drug repurposing. We extend our proposed mechanisms in the designing of physical inhibitors of amyloid aggregation considering shorter time frames and foolproof methods.Communicated by Ramaswamy H. Sarma.

Bioremediation of Hazardous Pollutants Using Enzyme-Immobilized Reactors.

Bioremediation uses the degradation abilities of microorganisms and other organisms to remove harmful pollutants that pollute the natural environment, helping return it to a natural state that is free of harmful substances. Organism-derived enzymes can degrade and eliminate a variety of pollutants and transform them into non-toxic forms; as such, they are expected to be used in bioremediation. However, since enzymes are proteins, the low operational stability and catalytic efficiency of free enzyme-based degradation systems need improvement. Enzyme immobilization methods are often used to overcome these challenges. Several enzyme immobilization methods have been applied to improve operational stability and reduce remediation costs. Herein, we review recent advancements in immobilized enzymes for bioremediation and summarize the methods for preparing immobilized enzymes for use as catalysts and in pollutant degradation systems. Additionally, the advantages, limitations, and future perspectives of immobilized enzymes in bioremediation are discussed.

Removal of cadmium and chromium heavy metals from aqueous medium using composite bacterial cellulose membrane

Bacterial cellulose (BC) membranes produced from biomass are emerging as an eco-friendly solution for water decontamination. The abundance of hydroxyl groups and the high surface-to-volume ratio of this material allow for the integration of diverse functional groups, providing the potential for targeted water purification applications. Beyond their intriguing mechanical properties and unique complex structure, bacterial cellulose membranes are biodegradable into sugar molecules and can be processed with minimal handling and using mild chemicals. Taken together, these features make them a compelling choice for water filtration in the context of environmental responsibility. In their natural state, BC membranes have limited potential for targeted wastewater treatment. One strategy for enhancing their functionality is to graft customized molecules onto their surface. Therefore, this study aims to impart multifunctionality to BC membrane for water filtration. Hence a novel precursor with hard and soft base functionalities consisting of amines, carbonyls, amides, hydroxyls etc. is designed and grafted onto BC membranes, grown to ensure surface uniformity and membrane-to-membrane repeatability of the properties. The structure of the synthesized precursors and the effective functionalization of the membrane are then validated through various structural characterization techniques. Changes in the morphology of BC membranes are examined using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Both the pristine and modified BC membranes undergo a series of tests to assess their filtration capabilities under low-pressure regime and their efficiency in removing representative cadmium and chromium ions. The modified BC membrane exhibits superior filtration performance and water permeability than pristine-BC. The targeted metal ions were rejected more than 90% from the effluent. The modified membranes demonstrated a flux recovery of above 90% maintaining its effectiveness even after five successive cleaning-filtration cycles.

Study on the Influence of Moisture Content and Void Ratio on the Disintegration of Red Clay

Guilin is a famous karst area, and currently the view that the disintegration of red clay will cause soil cave collapse is increasingly recognized. In order to study the influence of the coupling effect of moisture content and void ratio on the disintegration of red clay, different moisture contents and void ratios of Guilin red clay were placed on a self-made disintegration apparatus to record the real-time disintegration amount and observe the disintegration phenomenon. Images of the structural characteristics of soil were obtained by a scanning electron microscope (SEM). Additionally, nuclear magnetic resonance (NMR) was applied to analyze the distribution of water in both natural and saturated states. The results show that the disintegration rate of red clay decreases as the initial moisture content increases, but increases with the increase of void ratio. Both moisture content and void ratio affect the structural characteristics of red clay. When the moisture content remains constant, the soil changes from a three-peak to a two-peak structure as the void ratio increases. The total area and secondary peak area of the T2 spectrum increase, while the starting T2 value of the main peak shifts to the right and the area decreases. Meanwhile, the starting T2 value of the secondary peak shifts to the right and the area increases. When the void ratio remains constant, the starting T2 value of the main peak gradually shifts to the left and the area decreases as the moisture content increases. However, the starting T2 value of the secondary peak shifts to the right and the area decreases or first decreases and then increases. The disintegration rate does not exhibit a significant relationship with either pore volume or macropore volume. The combined water saturation shows a bilinear relationship with both the moisture content and void ratio, where it increases as the initial moisture content increases, but decreases as the void ratio increases, with a correlation coefficient of 0.9929. The disintegration rate has an exponential relationship with the combined water saturation, and it decreases as the combined water saturation increases, with a correlation coefficient of 0.9934.

Spatio-Temporal Prediction of Three-Dimensional Stability of Highway Shallow Landslide in Southeast Tibet Based on TRIGRS and Scoops3D Coupling Model

National Highway G559 is the first highway in Southeast Tibet into Motuo County, which has not only greatly improved the difficult situation of local roads, but also promoted the economic development of Tibet. However, rainfall-induced shallow landslides occur frequently along the Bomi–Motuo section, which seriously affects the safe operation and construction work of the highway. Therefore, it is urgent to carry out geological disaster assessment and zoning along the highway. Based on remote-sensing interpretation and field investigation, the distribution characteristics and sliding-prone rock mass of shallow landslides along the Bomi–Motuo Highway were identified. Three-dimensional stability analysis of regional landslides along the Bomi-Motuo Highway under different rainfall scenarios was carried out based on the TRIGRS and Scoops3D coupled model (T-S model). The temporal and spatial distribution of potential rainfall landslides in this area is effectively predicted, and the reliability of the predicted results is also evaluated. The results show that: (1) The slope structure along the highway is mainly composed of loose gravel soil on the upper part and a strong weathering layer of bedrock on the lower part. The sliding surface is mostly a circular and plane type, and the main failure types are creep–tensile failure and flexural–tensile failure. (2) Based on the T-S coupling model, it is predicted that the potential landslide along the Bomi–Motuo Highway in the natural state is scattered. The distribution area of extremely unstable and unstable areas accounts for 4.92% of the total area. In the case of extreme rainfall once in a hundred years, the proportion of instability area (Fs &lt; 1) predicted by the T-S coupling model 1 h after rainfall is 7.74%, which is 1.57 times that of the natural instability area. The instability area (Fs &lt; 1) accounted for 43.40% of the total area after 12 h of rainfall. The potential landslides were mainly distributed in the Bangxin–Zhamu section and the East Gedang section. (3) The TRIGRS and T-S coupling model is both suitable for predicting the temporal–spatial distribution of rainfall-induced shallow landslides, but the TRIGRS model has the problem of over-prediction. The instability area predicted by the T-S coupling model accounted for 43.30%, and 74% of the historical landslide disaster points in the area were correctly predicted. (4) In terms of rainfall response, the T-S coupling model shows higher sensitivity. The %LRclass (Fs &lt; 1) index of the T-S coupling model is above 50% in different time periods, and its landslide-prediction effect (%LRclass = 78.80%) was significantly better than that of the one-dimensional TRIGRS model (%LRclass = 45.50%) under a 12 h rainfall scenario. The research results have important reference significance for risk identification and disaster reduction along the G559 Bomi–Motuo Highway.

Effects of Lime on Bagasse Ash-Stabilised Expansive Soils

Management of agricultural wastes and improvement of construction soils have become increasingly necessary for sustainable development. This study therefore stabilised selected expansive soils using bagasse ash (BA) and lime, with a view to determining the effect of lime on BA-stabilised soils. Two soil samples (identified as Sample A and Sample B) were collected from two identified locations characterised with expansive soils in Ile-Ife, Osun State, Southwestern Nigeria. Using standard procedures, the following preliminary and geotechnical tests were conducted on the soil samples in their natural state: moisture content determination, particle size analysis, specific gravity, Atterberg limits, compaction and unconfined compressive strength (UCS). BA was then introduced to the soils in 5 %, 10 % and 15 % proportions by weight of dry soil. Thereafter, Atterberg limits and UCS tests were conducted on the BA-stabilised soils. Also 2.5 % lime was introduced to each proportion of BA earlier used. Atterberg limits and UCS tests were then conducted on the BA-lime stabilised soils. Results showed that the two soils in their natural state have high plasticity and they both belong to the A-2-7 group. For both BA and BA-lime stabilised soil samples, plasticity reduced with increase in the stabilisers, which implies an improvement in the soil properties. Also, UCS of both BA and BA-lime stabilised soil samples increased with optimum values at 10 % BA content. Expectedly, addition of lime increased the values of UCS for each combination of stabilisers. It was concluded that BA could be used to improve the properties of expansive soils and that the addition of certain proportions of lime does not have a negative impact on the stabilisation properties of BA, but rather improves it.

On Maximum Guaranteed Payoff in a Fuzzy Matrix Decision-Making Problem with a Fuzzy Set of States

The current study delves into a fuzzy matrix decision-making problem involving fuzzy sets of states. It establishes that a maximum guaranteed payoff constitutes a type-2 fuzzy set defined on the real line. Additionally, it provides the associated type-2 membership function. Moreover, the paper illustrates that the maximum guaranteed payoff type-2 fuzzy set of the decision-making problem can be broken down, based on the secondary membership grades, into a finite collection of fuzzy numbers. Each of these fuzzy numbers represents the maximum guaranteed payoff of the corresponding decision-making problem with a crisp set of states. This set corresponds to a specific cut of the original fuzzy set of states. Some properties of the maximum guaranteed payoff type-2 fuzzy set are investigated, and illustrative examples are provided. Since the problem formulation is symmetrical with respect to alternatives and states of nature, the results obtained can be used in the case of a fuzzy set of alternatives.

Experimental Study of Macro- and Micro-Scopic Damage in Red Sandstone under Dry and Wet Cycling

The high-strength red sandstone in its natural state is subjected to significant strength deterioration under alternating wet and dry conditions, which can cause many catastrophic problems in the process of engineering construction. It is important to deeply understand the damage mechanism of red sandstone under the action of dry and wet cycles. Therefore, this paper explores the mechanism of red sandstone’s uniaxial deformation and failure through indoor uniaxial compression tests, studies the damage to the microstructure of red sandstone under wet–dry cycles using scanning electron microscopy, and establishes a damage variable based on fractal dimension. The results show that with the increase of wet–dry cycles, the peak stress of red sandstone shows a decreasing trend, and the minimum peak stress is 17.3 MPa, which is a 46.62% decrease compared to the sample with 0 wet–dry cycles. During the wet–dry cycle process, there are four deformation characteristics of red sandstone samples, namely, crack compression, crack extension, progressive fracture, and crack penetration. SEM images show that the porosity, pore area, and fractal dimension all show a nonlinear increase, and the maximum damage variable can reach 10.41%. The research results can provide guidance for engineering design and slope failure mechanism research in red sandstone areas.

HLA-DR Expression in Natural Killer Cells Marks Distinct Functional States, Depending on Cell Differentiation Stage.

HLA-DR-positive NK cells, found in both healthy individuals and patients with different inflammatory diseases, are characterized as activated cells. However, data on their capacity for IFNγ production or cytotoxic response vary between studies. Thus, more precise investigation is needed of the mechanisms related to the induction of HLA-DR expression in NK cells, their associations with NK cell differentiation stage, and functional or metabolic state. In this work, HLA-DR-expressing NK cell subsets were investigated using transcriptomic analysis, metabolic activity assays, and analysis of intercellular signaling cascades. We demonstrated that HLA-DR+CD56bright NK cells were characterized by a proliferative phenotype, while HLA-DR+CD56dim NK cells exhibited features of adaptive cells and loss of inhibitory receptors with increased expression of MHC class II trans-activator CIITA. The activated state of HLA-DR-expressing NK cells was confirmed by higher levels of ATP and mitochondrial mass observed in this subset compared to HLA-DR- cells, both ex vivo and after stimulation in culture. We showed that HLA-DR expression in NK cells in vitro can be induced both through stimulation by exogenous IL-2 and IL-21, as well as through auto-stimulation by NK-cell-produced IFNγ. At the intracellular level, HLA-DR expression depended on the activation of STAT3- and ERK1/2-mediated pathways, with subsequent activation of isoform 3 of the transcription factor CIITA. The obtained results broaden the knowledge about HLA-DR-positive NK cell appearance, diversity, and functions, which might be useful in terms of understanding the role of this subset in innate immunity and assessing their possible implications in NK cell-based therapy.

Experimental test and mechanism analysis of soil crust erosion resistance of rammed earth Great Wall in rainy season

Rammed earth is a kind of cleaning material, widely used in all kinds of buildings in the world. The Great Wall of ancient China is a typical world cultural site built from rammed earth. The rammed earth Great Wall of Shanhaiguan is close to Bohai Bay, which has suffered from long-term erosion by rain, causing a series of problems such as soil loss, collapse and gully flushing. The protection materials of the rammed earth site have always puzzled scholars. However, during the rainy season, it was found that some of the walls at Xiaowan Gouge and Nantuzhuang Gouge in the Shanhaiguan Great Wall had unwashed traces, the soil surface of the walls was intact, and the anti-erosion ability of the walls was significantly higher than that of other places. In order to explore the reasons for its strong anti-erosion ability in the natural state of rammed earth wall, guide the protection of rammed earth Great Wall, and carry out different experimental tests to explore its anti-erosion reasons and internal mechanisms. Firstly, the characteristics of rammed soil were understood through the composition test of rammed soil, and the indoor and outdoor erosion test was carried out to determine that the anti-erosion reason was the protection of gray-green soil crust. The property and composition of soil crust were determined through the immersion test and genome sequencing. Finally, the protection mechanism of soil crust was analyzed by scanning electron microscopy.

Towards a Reliable Uncertainty Quantification in Residual Stress Measurements with Relaxation Methods: Finding Average Residual Stresses is a Well-Posed Problem

BackgroundIn a previous work, the problem of identifying residual stresses through relaxation methods was demonstrated to be mathematically ill-posed. In practice, it means that the solution process is affected by a bias-variance tradeoff, where some theoretically uncomputable bias has to be introduced in order to obtain a solution with a manageable signal-to-noise ratio.ObjectiveAs a consequence, an important question arises: how can the solution uncertainty be quantified if a part of it is inaccessible? Additional physical knowledge could—in theory—provide a characterization of bias, but this process is practically impossible with presently available techniques.MethodsA brief review of biases in established methods is provided, showing that ruling them out would require a piece of knowledge that is never available in practice. Then, the concept of average stresses over a distance is introduced, and it is shown that finding them generates a well-posed problem. A numerical example illustrates the theoretical discussionResultsSince finding average stresses is a well-posed problem, the bias-variance tradeoff disappears. The uncertainties of the results can be estimated with the usual methods, and exact confidence intervals can be obtained.ConclusionsOn a broader scope, we argue that residual stresses and relaxation methods expose the limits of the concept of point-wise stress values, which instead works almost flawlessly when a natural unstressed state can be assumed, as in classical continuum mechanics (for instance, in the theory of elasticity). As a consequence, we are forced to focus on the effects of stress rather than on its point-wise evaluation.

Study on Electrochemical Corrosion of Q235 Steel in Sand Containing HA Solution under a Natural Air-Dried State

To explore the corrosion of Q235 steel in sand containing a simulated haze aqueous solution (HA solution) under a natural air-dried state, the effect of moisture (age) on the corrosion of Q235 steel in sand was comprehensively studied by EIS, polarization curve, SEM, EDS and XPS. The physical and chemical properties of the sand showed that the sand containing the HA solution was basically neutral under natural air drying, and the temperature was around 20 °C. After 14 days, the moisture content gradually decreased from 30% to 0%, and the salinity decreased from 1.26% to 0.04%. With the increase in age, the Eocp gradually positively skews, indicating the corrosion kinetics of the Q235 steel decrease. The impedance spectra showed that in the frequency of 10−2–103 Hz, the impedance spectra exhibited a flat capacitive loop, and the corrosion of Q235 steel was the strongest in the sand containing HA solution on the 8 d. The polarization curves showed that with increasing age, the degree of corrosion of Q235 steel changed from medium or above to slight corrosion in the sand containing HA solution. The pitting characteristics of anode branch for polarization curve also indicate the faster corrosion kinetics of Q235 steel in the early age (1–5 d). The corrosion current density Io first increased and then decreased, and the highest value was 3.44 × 10−5 A/cm2 at 6 d. The average corrosion rate was 0.1629 mm/a. HA solution accelerates the corrosion of Q235 steel in sand without HA solution (average corrosion rate, 1.51 × 10−2 mm/a). A large amount of brown-yellow corrosion products (iron oxides, about 70–200 μm) presented on the surface of the Q235 steel. The corrosion of Q235 steel belonged to local corrosion, and the corrosion pits were connected to form a large dimple-like area. The HA solution and the porous structure of sand jointly affect the electrochemical corrosion of Q235 steel.

Tourism Color Run Party Event Management in Ngawi

With every city, big or small, hosting a steady schedule of fresh events each year, events or festivals have become an integral element of Indonesian culture. A prime example is Ngawi City, East Java's Color Run Party. Even then, this event brings up several concerns, including the buildup of trash and the degradation of Indonesian culture due to the absence of regional components. The impact of the Color Run Party on society and culture, as well as destination and visitor management, are covered in this article. A qualitative technique is employed as the primary instrument in this research method, which describes the object's natural state. Findings indicate that although destination management and other event-related factors have been well-organized, some areas, such as trash management and the absence of regional cultural components, still need improvement. So that this event not only concentrates on quantity but also considers the effects on the environment and culture, more cautious management is required. Keywords: local culture, tourism destination management, Color Run Party, festival, and event management.

Thermal runaway and soot production of lithium-ion batteries: Implications for safety and environmental concerns

Global energy shortages are becoming increasingly severe, and lithium-ion batteries are becoming an important substitute for fossil fuels. However, thermal runaway of a battery is a significant factor impacting battery industry development. Here, we conducted tests on battery thermal runaway using a combustion test chamber, analysing the effects of natural aging and state of charge (SOC) on battery thermal runaway. Additionally, EDS and XPS were used to analyse the soot particles formed during thermal runaway. Four stages in thermal runaway, e.g., battery bulge, smoke release, jet fire, and fire extinction. LiFePO4 with a higher SOC is more likely to cause thermal runaway. In addition, natural aging has an obvious impact on the intensity of thermal runaway. The gas products generated during a battery fire are identified as C1–C4 hydrocarbons. The soot generated by battery combustion presents a typical “core-shell” structure. The soot surface exhibits C–C, C–O, and O–H bonds, while the soot from early manufactured batteries also contains O–CO and π bonds. Soot contains not only C and O but also trace amounts of Li, F, P and Fe. These results reveal the characteristics of soot emission during thermal runaway of batteries, providing valuable insights for evaluating their toxicity and environmental impact.