Reasonable Adjustment Research Articles

An Improved Fick Model for Predicting Carbonation Depth of Concrete

Concrete carbonation can weaken its strength, cause the corrosion of steel reinforcement, and shorten its service life. Predicting the concrete carbonation depth is a critical aspect of assessing concrete durability. Currently, mathematical models for the concrete carbonation depth, exemplified by the Fick model, suffer from a low fitting accuracy and limited applicability due to the complexity and variability of concrete materials and service environments. In light of this, this work proposes an improved Fick model that incorporates a correction term to effectively enhance the curve fitting accuracy. The correction term in the improved model provides a reasonable adjustment for deviations in the development pattern of the concrete carbonation depth from the Fick model under different conditions, thereby broadening the applicability of the new model compared to the Fick model. Several sets of experimental data on the concrete carbonation depth are used to validate the universality and superiority of the new model. The results of the case studies indicate that the average prediction error and standard deviation of the new model are significantly smaller than those of the Fick model. For the first two examples, in most situations, the average prediction error and standard deviation of the new model are less than 50% of those of the Fick model, with the lowest average prediction error being only 4% and the lowest standard deviation being only 2% of the Fick model’s respective values. For the third example, the new model demonstrates superior predictive capability for the later-stage concrete carbonation depth compared to the Fick model and the ANN model. Specifically, for the carbonation depth of the concrete on the 56th day, the relative error between the predicted value of the new model and the measured value is only 2%, which is much smaller than the 27% of the Fick model and the 12% of the ANN model. These results demonstrate the unique advantage of the proposed model in predicting the carbonation depth, especially when only a limited amount of experimental data are available.

Polydimethylsiloxanes - Based Fluorescent Probe for H2S Detection in Living Cells.

The development of fluorescent probes for H2S detection especially in living cells is of great significance due to its fundamental role as signal molecule. A promising scaffold for the development of such probes is polydimethylsiloxanes (PDMS), which is cost-effectiveness, non-toxicity, flexibility, and biocompatibility and easy to post-functionalize. Surprisingly, fluorescent probes for H2S detection based on PDMS have not been investigated. Moreover, 4-nitro - 2,1,3-benzoxadiazole (NBD) derivates provides high fluorescence quantum yield, a large molar absorption coefficient, and sensitivity to environmental changes. Through reasonable design and adjustment of substituents on the NBD group, precise control of its fluorescence properties can be achieved. Herein, a novel H2S fluorescent probe, P-NBD, was designed and synthesized by a one-step aromatic ring nucleophilic substitution of Cl-NBD with a PDMS derivative. Due to the occurrence of the cleavage reaction strategy and the intramolecular charge transfer process, P-NBD can detect H2S via a colorimetric method. The limit of detection is down to 93 nM. P-NBD demonstrated considerable detection capability comparable to other reported types of H2S probes. Moreover, the probe can also be utilized for H2S imaging in HeLa cells. This work provides new insights into the design and synthesis of novel H2S probes while also offering experimental evidence for the application of PDMS in cellular imaging.

Neurodivergent (Autism and ADHD) student experiences of access and inclusion in higher education: an ecological systems theory perspective

AbstractHigher Education (HE) can be a complicated and isolating experience for neurodivergent students. Many systemic barriers and injustices create challenges for the accessibility and inclusivity of learning environments and curriculums. However, with the appropriate accommodations, staff guided by neurodiversity-affirming practices, accessible curricula, and opportunities to connect with neurodivergent peers, it can be highly rewarding. Through 15 in-depth, lived-experience-informed interviews with neurodivergent HE students who are Autistic and/or ADHDers in Australia, we analyse experiences at different system levels. By validating the robust framework of ecological systems theory in this context, we extend the academic understanding and add to the limited research on HE experiences for this marginalised, often ignored, but important student segment. We discover pivotal micro-systems of curricula, assessments, reasonable adjustment plans, spaces, teachers, students, and support services. Further contributions are made through the first extension of ‘feedback loops’ into research of HE micro-systems, and descriptions of macro and chrono-systems. With many HE systems erected and emergent to cater to the student majority, illuminating the experiences of neurodivergent students with these intersecting HE systems provides concrete insights for leadership, teachers, and support staff to improve accessibility and inclusion in HE.

Protocol of clinical population pharmacokinetics/pharmacodynamics analysis of alkaloids from the leaves of alstonia scholaris in acute bronchitis patients

Objective: To validate whether orally administered Alkaloid Capsules from the leaves of Alstonia scholaris (CALAS) can improve the clinical indices of acute bronchitis and to investigate the alterations in the relationship between its composition and pharmacodynamic (PD) markers, thereby providing a clinical reference for the administration of this medication. Methods: This is a prospectively planned, blinded, placebo-controlled, parallel-grouped clinical trial with aggregated population pharmacokinetics/PD (PPK/PPD) data. A total of 55 subjects will be randomly allocated into four arms; specifically, 10 of the 55 subjects will be selected randomly for the placebo arm, and will be orally administered placebo (Tid), and 45 subjects will be randomly assigned to CALAS treatment groups (20 mg, 40 mg, and 80 mg Tid, at 15 subjects per group). The medication, presence of cough and phlegm, as well as body temperature of every subject will be recorded daily during treatment. About 3–4 blood samples will be collected from each subject at the following points for PPK/PPD parameters analysis: at pre-dose (0 h) and post-dose at 15 min, 40 min, 1 h, 1.5 h, 2 h, 3 h, 4 h, 6 h, 8 h, 12 h, 24 h, 30 h, and 48 h after last dosing. All the subjects will be subjected to a laboratory examination and efficacy evaluation on day 8. Discussion: A new integrating strategy to explore the relationship among drug components, action pathways, and clinical efficacy will be established through this study. We aim to explore the mechanism of action of CALAS in the treatment of acute bronchitis on the premise of definite active ingredients and reliable clinical efficacy. It is difficult to enrol patients in classical PK research because it adopts an intensive sampling method, and it cannot quantify the variability of PK parameters (Intra-individual variation, inter-individual variation and weekly variation). Moreover, the extrapolation and prediction of dosage regimens in different species and populations cannot be achieved. Therefore, the PPK/PPD method, which takes advantage of sparse data (3–5 time points sampling per patient), is adopted to determine the measurable pathological and physiological factors that can influence dose concentration to guide reasonable dose adjustment towards achieving optimal clinical effects.

Response Surface Design Models to Predict the Strength of Iron Tailings Stabilized with an Alkali-Activated Cement

Tailing storage facilities are very complex structures whose failure generally leads to catastrophic consequences in terms of casualties, serious environmental impacts on local biodiversity, and disruptions in the mineral supply. For this reason, structures at risk must be reinforced or decommissioned. One possible option is its reinforcement with compacted filtered tailings stabilized with binders. Alkali-activated binders provide a more sustainable solution than ordinary Portland cement but require an optimization of the tailing–binder mixture, which, in some cases, can lead to a substantial experimental effort. Statistical models have been used to reduce the number of those experiments, but a rational design methodology is still lacking. This methodology to define the right mixture for a required strength should consider both the mixture components and in situ conditions. In this paper, response surface methods were used to plan and interpret unconfined compression strength test results on an iron tailing stabilized with alkali-activated binders. It was concluded that the fly ash content was the most important parameter, followed by the liquid content and sodium hydroxide concentration. From the obtained results, several statistical models were defined and compared according to the definition of a strength prediction model based on a mixture index parameter. It was interesting to observe that models with the porosity cement index still provide reasonable adjustment even when different tailings’ water contents are considered.

Support for Neurodivergent Students in Veterinary Education Part 1: Current Practice and Roundtable Discussion of Recommendations.

Approximately 10% of undergraduate student populations are neurodivergent. Such students have differences in executive functioning and social communication skills, which can confer both strengths and challenges in the academic environment. Specific challenges presenting in the veterinary curriculum include the intense workload, unpredictable nature of work, and high level of interpersonal and communication skills required in clinical settings. Extramural studies (EMS) occur remote from university support systems, adding further challenge for some students. A survey was sent to all current United Kingdom veterinary schools in 2022 to identify current support for neurodivergent students. An interactive roundtable discussion was held to brainstorm best practice for harnessing the power of neurodiversity in the clinical learning environment. Several consistent themes emerged. Most veterinary schools provide some degree of support for neurodivergent individuals, but support varies widely. Four of the 8 schools provide support at open days and/or following offers, with one school offering a summer school. Five schools confirmed that accommodations were made to clinical rotations and/or extramural studies in line with a support plan from their Disability Service. Despite these steps to assist neurodivergent students, support could, and should, be increased to improve the student experience. Suggested enhancements include a supportive environment for the empowerment of disclosure, neurodiversity awareness training for university staff and placement providers, provision of reasonable adjustment guidelines for EMS providers, clinical/intramural rotation orientation and support, and student access to a neurodiversity mentor/coach.

Potentially avoidable mortality among adults with intellectual disability.

Persons with intellectual disabilities (ID) face pronounced health disparities. The aim of this study was to describe premature mortality by causes of death and avoidable mortality among persons with ID compared to the general Danish population. This study is based on a Danish nationwide cohort of adults (aged 18-74 years) with ID (n = 57663) and an age- and sex-matched reference cohort (n = 607 097) which was established by linkage between several registers. The cohorts were followed in the Register of Causes of Death between 2000 and 2020. Causes of death were categorized into preventable, treatable, or unavoidable deaths using the OECD/Eurostat classification and furthermore categorized into specific interventions. We compared the observed and expected number of deaths by calculating standardized mortality ratio (SMR). Among persons with ID the number of deaths was 9400 whereof 5437 (58%) were avoidable. SMR for preventable deaths, e.g. by reducing smoking and alcohol intake or by vaccination, was 2.62 (95% CI, 2.51-2.73), and SMR for treatable deaths, e.g. by earlier diagnosis and treatment, was 6.00 (5.72-6.29). Unavoidable mortality was also six-fold increased (SMR = 6.03; 5.84-6.22). Preventable deaths were higher for persons with mild ID compared to severe ID, while treatable and unavoidable mortality were highest for persons with severe ID. The study confirmed that persons with ID have an amplified risk of mortality across all categories. There is a need for competence development of social care and healthcare personnel and reasonable adjustment of health promotion programs and healthcare services for people with ID.

Effect of electrolyte pH value on microstructure and corrosion resistance of black MAO coating on 6063 aluminum alloy

Black micro-arc oxidation (MAO) coatings were obtained on the surface of 6063 aluminum alloy by using the MAO technique in silicate electrolyte with colorant NH4VO3. The work aimed to study the effect of adjusting the electrolyte pH (pH10, pH11, pH12, and pH13) on the microstructure, mechanical properties, and corrosion resistance of black MAO coatings on 6063 aluminum alloy. The experimental results showed that the electrolyte pH had an important effect on the macroscopic morphology of the MAO coatings. As the electrolyte pH value increased, the process voltage of the sample decreased, the duration of the anodic oxidation stage and the spark discharge stage were shortened, while the duration of the micro arc oxidation stage was prolonged. Reasonable adjustment of the electrolyte pH could reduce the poriness and defects of the coatings, decrease the surface roughness of the coatings, and improve the quality and wear resistance of the coatings. The corrosion resistance of the black MAO coating obtained in the electrolyte with pH12 was superior and the corrosion current density was only 3.207×10−7 A/cm2. The immersion corrosion test further demonstrated the same results of corrosion resistance.

Umbrella review of hospital passports: Their use and improvements

AbstractBackgroundThe hospital or health passport is widely acknowledged as a central element in making reasonable adjustments for patients with intellectual disabilities. Historically, the health passport has been used exclusively for patients with intellectual disabilities; however, it has wider applications for any patient requiring additional support. Commonly, it documents past medical history, communication needs and a person's means of expressing pain. There are, however, significant barriers to their use, meaning patients are unable to access adjustments to improve their experiences in a healthcare system that already marginalises and discriminates against people with intellectual disabilities. This umbrella review aims to establish whether the passport is an effective reasonable adjustment, identify barriers to its use and make recommendations to alleviate these barriers.MethodsDatabase and citation searches informed a synthesis of international evidence to address these aims. Following the removal of duplicates and screening, nine review papers originating from the United Kingdom, Australia and Ireland were identified for inclusion. Seven focus on the use of passports for patients with intellectual disabilities, one on the use of passports for autistic people, and one exploring the use of passports for patients with dementia.FindingsThe results demonstrated that the passports are effective in improving care for patients with intellectual disabilities. However, there are barriers to its routine use. We identified three main issues with the current use of the hospital passport. First, there is a need for greater managerial support to implement reasonable adjustments. Second, standardisation of the passports at a national level will make them more accessible to healthcare professionals and will ensure that information is not ‘buried’; the development of a standardised passport must involve consultation of patients, carers and staff to meet the needs of all stakeholders. Finally, education for all healthcare staff to raise awareness of the passport and ensure it is utilised appropriately will ultimately pave the way for positive, long‐lasting change.ConclusionsPassports can be an effective means of communicating reasonable adjustments. Addressing a lack of awareness of its utility, ensuring managerial commitment to implementing reasonable adjustments and making the passport accessible through a standardised format will empower patients to engage with their own care.

Research on High-Pressure Water Jet Interference for Collision Prevention of Waterway Viaduct Piers: Case Study of Guangzhou Lixinsha Bridge

In this paper, with the frequent occurrence of ship–bridge collision accidents as the context and the collision accident of the Lixinsha Bridge in China as the background, the scenario of a ship impacting a pier was simulated using ANSYS-FLUENT software, and the practical application possibility of the high-pressure water jet interference (HPWJI) anti-collision method was thoroughly investigated. Through the simulation analysis, the effectiveness of a high-pressure water jet with a total flow rate of 45 m3/s in altering the navigation direction of large-tonnage (2000 t) ships and avoiding obstacles was verified. Additionally, its impact on the stress of the ship steel plates and navigation status was also explored. It was found that, with reasonable layout and parameter adjustment, the high-pressure water jet technology could effectively intervene in the ship’s navigation trajectory while ensuring the structural safety of the ship, with minimal impact on the ship’s navigation stability and passenger comfort. Furthermore, the injection angle of the high-pressure water jet had a significant impact on the deflection and deceleration of the ship. Specifically, when the water jet impacted the ship along its forward direction, it could effectively increase the ship’s deceleration and deflection time, reducing the speed from 2.55 m/s to 1.7 m/s, a decrease of approximately 33%, significantly enhancing collision prevention effectiveness. This research provides important guidance for the practical application of high-pressure water jet collision prevention technology and is of great significance for improving the safety of waterway transportation.

Honeycomb-configured dissipative nanofluid flow within a squeezed channel with entropy generation: regression and numerical evaluations

PurposeNanosized honeycomb-configured materials are used in modern technology, thermal science and chemical engineering due to their high ultra thermic relevance. This study aims to scrutinize the heat transmission features of magnetohydrodynamic (MHD) honeycomb-structured graphene nanofluid flow within two squeezed parallel plates under Joule dissipation and solar thermal radiation impacts.Design/methodology/approachMass, energy and momentum preservation laws are assumed to find the mathematical model. A set of unified ordinary differential equations with nonlinear behavior is used to express the correlated partial differential equations of the established models, adopting a reasonable similarity adjustment. An approximate convergent numerical solution to these equations is evaluated by the shooting scheme with the Runge–Kutta–Fehlberg (RKF45) technique.FindingsThe impression of pertinent evolving parameters on the temperature, fluid velocity, entropy generation, skin friction coefficients and the heat transference rate is explored. Further, the significance of the irreversibility nature of heat transfer due to evolving flow parameters are evaluated. It is noted that the heat transference rate performance is improved due to the imposition of the allied magnetic field, Joule dissipation, heat absorption, squeezing and thermal buoyancy parameters. The entropy generation upsurges due to rising magnetic field strength while its intensification is declined by enhancing the porosity parameter.Originality/valueThe uniqueness of this research work is the numerical evaluation of MHD honeycomb-structured graphene nanofluid flow within two squeezed parallel plates under Joule dissipation and solar thermal radiation impacts. Furthermore, regression models are devised to forecast the correlation between the rate of thermal heat transmission and persistent flow parameters.

A deep learning and large group consensus based cruise satisfaction evaluation model with online reviews

Cruise satisfaction assessment is pivotal for both passenger experiences and the enterprise's industry competitiveness. To do that, this research proposes a deep learning based cruise satisfaction evaluation model by integrating cruise online reviews and a large group consensus model. In order to acquire the dimensions influencing cruise passenger satisfaction, attribute extraction is employed. Unlike traditional methods that rely on word-based attribute representation, this method employs sentence-level information to comprehensively capture attributes that are of genuine concern to users, including implicit ones. Additionally, it utilizes the pre-trained language model, BART, to accurately predict sentiment polarity by treating sentiment analysis as a generation task based on online reviews from the CruiseCritic website. Subsequently, the proposed consensus model is implemented to determine the final satisfaction level, taking into consideration subgroup weights and an ideal solution-based feedback mechanism. This mechanism facilitates the provision of reasonable adjustment recommendations tailored to the context of online evaluations. Ultimately, the research findings contribute valuable insights to enhance service quality within the Royal Caribbean International cruise line.

Reasonable adjustment for inclusive development: a cautionary case study of Australian VET teachers’ experience

PurposeVocational education and training (VET) in Australia has for some time been driven by an agenda of “reasonable adjustment”, in which practices are modified to ensure equitable access and participation by disadvantaged students. However, the growing marketization of VET has instead encouraged the use of more flexible approaches to attract and retain students from diverse backgrounds. They have thus paralleled and confounded reasonable adjustment practices for inclusive development. This study sought to identify the moral dilemmas experienced by VET teachers arising from implementing reasonable adjustment practices.Design/methodology/approachThis phenomenological research project used in-depth conversational interviews with 19 experienced VET teachers from a diversity of teaching fields to identify moral dilemmas experienced as arising from changes in their workplace contexts.FindingsOne of the identified dilemmas was responding flexibly to heightened student diversity, to which study participants largely responded by prioritising the economic imperative over social inclusion. Well-intended actions thus led to unintentionally damaging outcomes, raising important ethical questions about the relative value of economic and social development outcomes and the role of reasonable adjustment in their attainment. The study also highlights the lack of appropriate VET teacher training in managing ethical conflicts to minimise risks to themselves and their employing organizations.Originality/valueAs a case study of inclusive development policies in practice, this research may be seen as a cautionary tale for inclusive development policies in other countries with similarly strong VET economic and socially inclusive development policies for sustainability. The paper thus opens a dialogue for critical reflection on the current problems in a reasonable development approach in the field of comparative and international education. Those two parallel agendas have presented VET teachers and trainers with ethically challenging situations in which the economic and social development imperatives are experienced as being conflict with each other.

Understanding dilution effects on particle-containing pesticide droplets deposition on rice leaf via developing CFD-VOF-DPM model.

Pesticide dilution is one of the essential aspects of plant protection. However, the effect of dilution on the deposition characteristics of pesticide droplets containing particulate additives on crop leaf surfaces remains unclear and warrants further research. Herein, a validated computational fluid dynamics (CFD)-volume of fluid (VOF)-discrete phase model (DPM) numerical model was developed to analyze the influence of particle content on the deposition behavior of droplets on the leaf surface comparatively, taking into account the particle content of different diluted thifluzamide solutions. Additionally, the study aimed to analyze further the kinetic behavior of pesticide droplets landing on rice leaves across different dilution conditions. Pesticide droplets diluted 100-fold had a lower retraction rate during spreading than particle-free droplets, so the solution is more easily deposited in the leaves. Moreover, the low dilution (high concentration) increased the critical adhesion rate between droplets and rice leaves, inhibiting the bouncing of droplets on the leaf surface, thus promoting their effective deposition on the surface. In addition, low dilution (high concentration) is not conducive to spreading droplets when the impact velocity is high, and it also results in a large amount of pesticide use. The actual application process can be through understanding the dilution factor of the configured pesticide solution, and reasonable adjustment of the nozzle pressure can effectively improve the utilization rate of pesticides and reduce the pollution brought by pesticides to the environment. These results provide an essential reference for studying pesticide droplet deposition characteristics, including rice plant protection and spraying technology. © 2024 Society of Chemical Industry.

Obesity and lipid metabolism in the development of osteoporosis (Review).

Osteoporosis is a common bone metabolic disease that causes a heavy social burden and seriously threatens life. Improving osteogenic capacity is necessary to correct bone mass loss in the treatment of osteoporosis. Osteoblasts are derived from the differentiation of bone marrow mesenchymal stem cells, a process that opposes adipogenic differentiation. The peroxisome proliferator‑activated receptor γ and Wnt/β‑catenin signaling pathways mediate the mutual regulation of osteogenesis and adipogenesis. Lipid substances play an important role in the occurrence and development of osteoporosis. The content and proportion of lipids modulate the activity of immunocytes, mainly macrophages, and the secretion of inflammatory factors, such as IL‑1, IL‑6 and TNF‑α. These inflammatory effectors increase the activity and promote the differentiation of osteoclasts, which leads to bone imbalance and stronger bone resorption. Obesity also decreases the activity of antioxidases and leads to oxidative stress, thereby inhibiting osteogenesis. The present review starts by examining the bidirectional differentiation of BM‑MSCs, describes in detail the mechanism by which lipids affect bone metabolism, and discusses the regulatory role of inflammation and oxidative stress in this process. The review concludes that a reasonable adjustment of the content and proportion of lipids, and the alleviation of inflammatory storms and oxidative damage induced by lipid imbalances, will improve bone mass and treat osteoporosis.

Effect of impeller structure on aerodynamic performance and noise reduction of a small multi-blade centrifugal fan

In this study, the numerical simulation and orthogonal test are combined to study the effects of blade outlet angle, blade inlet angle, and blade number on the centrifugal fan flow characteristics, stress distribution, and noise control. The experimental tests were carried out to confirm the accuracy of the computational model. The computational fluid dynamics (CFD) technology was used to establish 16 groups of impeller models and derive the optimal parameter combination form. The results show that the blade inlet angle and outlet angle have more significant effects on efficiency and flow rate of fans. Among different optimize structures, the A8 fan with an inlet angle of 60°, an outlet angle of 180°, and a blade number of 45, has the best aerodynamic performance, with a 17.4% increase in flow rate, a 3.3% increase in efficiency, a 7.6% reduction in noise and a 23.0% reduction in impeller stress, compared to the original fan. Reasonable adjustment of the inlet and outlet angles greatly improves fluid distribution and suppresses flow separation. Furthermore, the noise can be reduced by lessening the disturbance between the volute tongue and wake flow, so the flow state gets greatly improved at the volute tongue region.

Combination of multiple strengthening mechanisms facilitates excellent strength-ductility balance in metastable β titanium alloy

A remarkable balance between the strength (844 MPa) and ductility (35.6%) of the Ti–4V–2Mo–2Fe alloy was achieved by hot rolling. Notably, alloy specimens rolled at 700 °C exhibited a yield strength exceeding 1 GPa. This outstanding yield strength from several factors: fine-grain strengthening, dislocations strengthening in the non-recrystallized region, and precipitation strengthening of α phase and isothermal ω phase. Within the 750–900 °C temperature range, a notable enhancement in yield strength, uniform elongation, total elongation, and work hardening rate was observed as rolling temperature decreased. This enhancement can be attributed to the “dynamic Hall-Petch effect” caused by the stress-induced {332}<113> twins. Additionally, grain refinement and stress-induced ω phase further enhanced ductility and work hardening capacity. These findings show that reasonable adjustment of microstructure and deformation mechanism is an effective strategy to achieve excellent strength-ductility balance of metastable β titanium alloys.

Cu–Mg dilute alloys- Assessment of strengthening, internal friction, and electrical conductivity

Overcoming the strength-conductivity trade-off has long been an issue for commercial copper alloys. However, a synergy between strength and electrical conductivity can be achieved by reasonable adjustment of the microstructure. It is known that the formation of Short-Range Order (SRO) in a solid solution can change the mechanical and electrical behavior of the materials. Currently, the prediction of SRO formation is widely based on computational techniques. In the present study, Miedema's thermodynamical approach is applied for the assessment of alloying elements' potential to form SRO in the copper lattice. According to this methodology, magnesium tends to form SRO with copper. The mechanical, electrical, and structural properties of the oxygen-free copper (Cu-OFC), Cu–Mg0.14 wt%, and Cu–Mg0.50 wt% strips fabricated by continuous extrusion forming process (Conform) have been investigated. According to the optical microscopy investigations, the average grain sizes of the Mg alloyed samples were observed to be lower compared to that of OFC. The Vickers hardness measurements were carried out and the hardness values for Cu-OFC, Cu–Mg0.14, and Cu–Mg0.50 samples were recorded as 56.3 HV, 76.05 HV, and 87.68 HV, and the yield strengths as 80, 150 and 260 MPa, respectively. A decrement in electrical conductivity was observed with the increasing Mg addition. Dynamic elastic modulus test measurements, which refer to internal friction, have been performed by impulse excitation technique to elucidate the presence of SRO in the dilute Cu–Mg systems. The anomalous “bump” formation in the temperature-elastic modulus profiles of the Cu–Mg samples was remarkable which has been attributed to the SRO formation.

Influence of advance direction on surrounding rock stability of main ramp under deep high ground stress

Due to the widespread use of trackless equipment in metal mines, the main ramp has become a major development roadway in large mines. Under deep high ground stress condition, the stability of the surrounding rock of the main ramp is subject to significant variability due to the change in the advance direction, leading to structural failure in different areas of the roadway. Because the support design scheme of surrounding rock of main ramp will not pay attention to the advance direction of roadway, leading to the key support area of the surrounding rock is not clear, resulting failure of the local supporting form occur frequently. Therefore, this paper adopts the combination of on-site investigation and numerical simulation to carry out the stability analysis of the surrounding rock under different advance directions of the roadway. Through on-site investigation, various failure modes of surrounding rock induced by the change of the advance direction of the roadway are summarized, and the key supporting area of surrounding rock of main ramp is determined according to the angle change between the roadway advance direction and the intermediate principal stress. The extent of the risk zone of the roadway surrounding rock is defined based on the Drucker-Prager criterion, which can be used as the new basis for the design of roadway support parameters. The results show that: As the angle between the advance direction and the intermediate principal stress increases, the degree of deformation of the surrounding rock decreases linearly, and the volume of the plastic and risk zones of the surrounding rock decreases nonlinearly. Based on the distribution of the strain energy density of the roadway surrounding rock, when the angle between the advance direction and the intermediate principal stress is small, the roadway surrounding rock is more prone to the floor heave phenomenon. When the angle between the advance direction and the intermediate principal stress is larger, the roadway surrounding rock is prone to the full-section failure phenomenon. Based on the block theory, when the advance direction is changed, the location and production of key blocks have significant variability, leading to the need for reasonable adjustment of the support parameters for the surrounding rock. The research results of this paper are of guiding significance for the optimization of the surrounding rock support scheme of the main ramp.

Optimizing the key parameter to accelerate the recovery of AMOC under a rapid increase of greenhouse gas forcing

Atlantic Meridional Overturning Circulation (AMOC) plays a central role in long-term climate variations through its heat and freshwater transports, which can collapse under a rapid increase of greenhouse gas forcing in climate models. Previous studies have suggested that the deviation of model parameters is one of the major factors in inducing inaccurate AMOC simulations. In this work, with a low-resolution earth system model, the authors try to explore whether a reasonable adjustment of the key model parameter can help to re-establish the AMOC after its collapse. Through a new optimization strategy, the extra freshwater flux (FWF) parameter is determined to be the dominant one affecting the AMOC's variability. The traditional ensemble optimal interpolation (EnOI) data assimilation and new machine learning methods are adopted to optimize the FWF parameter in an abrupt 4×CO2 forcing experiment to improve the adaptability of model parameters and accelerate the recovery of AMOC. The results show that, under an abrupt 4×CO2 forcing in millennial simulations, the AMOC will first collapse and then re-establish by the default FWF parameter slowly. However, during the parameter adjustment process, the saltier and colder sea water over the North Atlantic region are the dominant factors in usefully improving the adaptability of the FWF parameter and accelerating the recovery of AMOC, according to their physical relationship with FWF on the interdecadal timescale.