Rubber-like materials that are commonly used in structural applications are modelled using hyperelastic material models.Most of the hyperelastic materials are nearly incompressible,which poses challenges,i.e.,volumetr...Rubber-like materials that are commonly used in structural applications are modelled using hyperelastic material models.Most of the hyperelastic materials are nearly incompressible,which poses challenges,i.e.,volumetric locking during numerical modelling.There exist many formulations in the context of the finite element method,among which the mixed displacementpressure formulation is robust.However,such a displacement-pressure formulation is less explored in meshfree methods,which mitigates the problem associated with mesh distortion during large deformation.This work addresses this issue of alleviating volumetric locking in the element-free Galerkin method(EFGM),which is one of the popular meshfree methods.A two-field mixed variational formulation using the perturbed Lagrangian approach within the EFGM framework is proposed for modelling nearly incompressible hyperelastic material models,such as Neo-Hookean and Mooney-Rivlin.Taking advantage of the meshless nature of the EFGM,this work introduces a unique approach by randomly distributing pressure nodes across the geometry,following specific guidelines.A wide spectrum of problems involving bending,tension,compression,and contact is solved using two approaches of the proposed displacement-pressure node formulation involving regular and irregular pressure node distribution.It is observed that both approaches give accurate results compared to the reference results,though the latter offers flexibility in the pressure nodal distribution.展开更多
Electric vehicle(EV) drive trains are constantly subjected to an imbalance between demanded torque and generated electromagnetic torque due to unpredictable terrain, traffic, and other external factors. This imbalance...Electric vehicle(EV) drive trains are constantly subjected to an imbalance between demanded torque and generated electromagnetic torque due to unpredictable terrain, traffic, and other external factors. This imbalance leads to significant torsional vibrations and speed fluctuations, which not only compromise passenger comfort but also exert additional mechanical stress on the EVs. Conventional sensorless methods offer speed estimation and control;however, they provide suboptimal performance with sudden load torque disturbances and operational uncertainties, especially at low speeds and across diverse real-world driving cycles. To address these challenges and improve system robustness, this work proposes an advanced sensorless integral sliding mode control(ASISMC) that enhances performance under diverse operating conditions. The proposed ASISMC methodology shows robust performance across a wide speed range, effectively mitigating abrupt load torque disturbances while minimizing the effect of uncertainties within the system dynamics. The approach is experimentally validated for a wide range of speeds and periodic/non-periodic load torque disturbances. Additional validation through the new European driving cycle(NEDC) and urban dynamometer driving schedule(UDDS) demonstrates the method's effectiveness and reliability in real-world driving conditions.展开更多
This paper introduces dynamic mode decomposition(DMD)as a novel approach to model the breakage kinetics of particulate systems.DMD provides a data-driven framework to identify a best-fit linear dynamics model from a s...This paper introduces dynamic mode decomposition(DMD)as a novel approach to model the breakage kinetics of particulate systems.DMD provides a data-driven framework to identify a best-fit linear dynamics model from a sequence of system measurement snapshots,bypassing the nontrivial task of determining appropriate mathemat-ical forms for the breakage kernel functions.A key innovation of our method is the instilling of physics-informed constraints into the DMD eigenmodes and eigenvalues,ensuring they adhere to the physical structure of particle breakage processes even under sparse measurement data.The integration of eigen-constraints is computationally aided by a zeroth-order global optimizer for solving the nonlinear,nonconvex optimization problem that elicits system dynamics from data.Our method is evaluated against the state-of-the-art optimized DMD algorithm using both generated data and real-world data of a batch grinding mill,showcasing over an order of magnitude lower prediction errors in data reconstruction and forecasting.展开更多
The increasing integration of small-scale structures in engineering,particularly in Micro-Electro-Mechanical Systems(MEMS),necessitates advanced modeling approaches to accurately capture their complex mechanical behav...The increasing integration of small-scale structures in engineering,particularly in Micro-Electro-Mechanical Systems(MEMS),necessitates advanced modeling approaches to accurately capture their complex mechanical behavior.Classical continuum theories are inadequate at micro-and nanoscales,particularly concerning size effects,singularities,and phenomena like strain softening or phase transitions.This limitation follows from their lack of intrinsic length scale parameters,crucial for representingmicrostructural features.Theoretical and experimental findings emphasize the critical role of these parameters on small scales.This review thoroughly examines various strain gradient elasticity(SGE)theories commonly employed in literature to capture these size-dependent effects on the elastic response.Given the complexity arising from numerous SGE frameworks available in the literature,including first-and second-order gradient theories,we conduct a comprehensive and comparative analysis of common SGE models.This analysis highlights their unique physical interpretations and compares their effectiveness in modeling the size-dependent behavior of low-dimensional structures.A brief discussion on estimating additional material constants,such as intrinsic length scales,is also included to improve the practical relevance of SGE.Following this theoretical treatment,the review covers analytical and numerical methods for solving the associated higher-order governing differential equations.Finally,we present a detailed overview of strain gradient applications in multiscale andmultiphysics response of solids.Interesting research on exploring the relevance of SGE for reduced-order modeling of complex macrostructures,a universal multiphysics coupling in low-dimensional structures without being restricted to limited material symmetries(as in the case of microstructures),is also presented here for interested readers.Finally,we briefly discuss alternative nonlocal elasticity approaches(integral and integro-differential)for incorporating size effects,and conclude with some potential areas for future research on strain gradients.This review aims to provide a clear understanding of strain gradient theories and their broad applicability beyond classical elasticity.展开更多
Background:Acute Myeloid Leukemia(AML)is a highly aggressive clonal hematological malignancy with limited treatment options.This study aimed to evaluate the therapeutic potential of nigericin,a polyether ionophore der...Background:Acute Myeloid Leukemia(AML)is a highly aggressive clonal hematological malignancy with limited treatment options.This study aimed to evaluate the therapeutic potential of nigericin,a polyether ionophore derived from Streptomyces DASNCL-29,as a mitochondrial-targeted agent for AML treatment.Methods:Nigericin was isolated from Streptomyces DASNCL-29 and characterized via chromatography and NMR.Its cytotoxicity was tested in MOLM13(sensitive and venetoclax-resistant)and HL60(sensitive and cytarabine-resistant)cells using the MTT assay.Mitochondrial dysfunction was assessed by measuring reactive oxygen species(ROS),mitochondrial membrane potential(Δψm),and mitochondrial mass.Apoptosis was evaluated with Annexin V/PI assays and immunoblotting,while proteomic analysis was conducted using Liquid Chromatography-Tandem Mass Spectrometry(LC-MS/MS)to identify differentially regulated proteins.Results:Nigericin demonstrated potent cytotoxicity with IC50 values of 57.02 nM in MOLM13-sensitive,35.29 nM in MOLM13-resistant,20.49 nM in HL60-sensitive,and 1.197 nM in HL60-cytarabine-resistant cells.Apoptosis was confirmed by Annexin V/PI staining and caspase-3/PARP cleavage,along with MCL-1 downregulation.Mitochondrial dysfunction was evident from increased ROS,reducedΔψm,and decreased mitochondrial mass.Proteomic profiling identified 264 dysregulated proteins,including a 3.8-fold upregulation of Succinate Dehydrogenase[Ubiquinone]Flavoprotein Subunit A(SDHA).Conclusion:Nigericin induces apoptosis in AML cells by disrupting mitochondrial function and enhancing oxidative stress.Its nanomolar potency highlights the need for further mechanistic studies and in vivo evaluations to explore its potential in AML treatment.展开更多
The waste management sector plays a vital role in environmental sustainability and public health.However,it faces significant challenges due to a multi-dimensional skills gap that hinders the effective management,proc...The waste management sector plays a vital role in environmental sustainability and public health.However,it faces significant challenges due to a multi-dimensional skills gap that hinders the effective management,processing and disposal of waste.Effective waste management requires increasing levels of technical expertise,analytical proficiency,behavioural skills and digital competence.However,one critical point of concern is the lack of requisite technical skills required for the optimal operation and maintenance of equipment and machinery used for waste management and disposal.Using desk research and focus group interviews of stakeholders in Nigeria and Ghana,we analyzed the skills gap in the sector in order to identify the skills that are currently short in supply in both countries.Our study revealed three broad skills need areas:(1)Skill requirements for youth employment in the waste management sector;(2)Machineries,technologies and tools used for waste management;and(3)Technical skills requirements for green waste management.The study concludes with a mapping of technologies and skills in the waste management sector while highlighting the impact of the existing skills deficit on the sector’s effectiveness and how it can be addressed through structured technical training programs for stakeholders in the sector.展开更多
BACKGROUND Spinal tuberculosis(TB),also known as Pott’s spine,remains a significant global health issue,particularly in regions with a high TB burden.The disease presents complex challenges in diagnosis,management,an...BACKGROUND Spinal tuberculosis(TB),also known as Pott’s spine,remains a significant global health issue,particularly in regions with a high TB burden.The disease presents complex challenges in diagnosis,management,and treatment,prompting a growing interest in research over recent years.The advancements in imaging,diagnostics,and treatment strategies have driven an increased focus on publishing clinical outcomes,review articles,and case series related to spinal TB(STB).AIM To perform a bibliometric analysis of STB research published over the last 5 years(2019-2023)to identify trends in publication volume,contributions by country,and the nature of the research being conducted.METHODS A comprehensive bibliometric analysis was conducted using the PubMed database,focusing on research articles published between 2019 and 2023.Keywords such as“spine tuberculosis,”“spinal TB,”“TB spine,”and“Pott’s spine”were utilized to capture relevant publications.Articles were analyzed based on the type of research(e.g.,case reports,review articles,cohort studies,randomized controlled trials[RCTs]),number of citations,and country of origin based on the corresponding author's details.Further subgroup analysis was performed according to the TB burden in various countries to assess research trends in high-burden regions.RESULTS A total of 528 articles met the inclusion criteria for this bibliometric analysis.The majority of articles were published between 2020 and 2023(440/528;83.3%),while the lowest number was published in 2019(88/528;16.7%).India led the global contributions with 25.8%of the total publications,followed by China(19.9%)and the United States(10.4%).Combined,African countries contributed 6.8%of the research on STB.Regarding the type of articles,case reports and case series dominated the literature(353/528;66.9%),followed by review articles(120/528;22.7%)and cohort studies(45/528;8.5%).Only 1.9%(10/528)of the studies were RCTs.Countries such as the United States,Germany,the United Kingdom,and Japan have pioneered the use of artificial intelligence(AI)in the diagnostic processes for STB,while India,China,South Africa,and other countries have been pivotal in conducting clinical trials and improving clinical management strategies.CONCLUSION This bibliometric analysis revealed a significant increase in STB research over the last 5 years,with India and China being the leading contributors.However,most publications are case reports or case series,with a limited number of RCTs.The results highlighted the need for more high-quality research,especially in terms of RCTs and innovations in diagnostic technologies.Additionally,the application of AI to STB diagnostics shows promise in developed countries,while high-burden countries are focusing on clinical trials and management strategies.展开更多
A total of 393 potholes(368 fluvial and 25 marine potholes)were studied at seven different sites in both the fluvial and marine environments.Diverse bedrock properties and large-scale delivery of tools and grinders re...A total of 393 potholes(368 fluvial and 25 marine potholes)were studied at seven different sites in both the fluvial and marine environments.Diverse bedrock properties and large-scale delivery of tools and grinders regulate the dynamic growth,truncation,and amalgamation of potholes.Therefore,the principal objectives of the study are(i)to examine the relationship between the growth of potholes and substrate lithological with structural characteristics(applying geospatial and Schmidt hammer for rock strength analysis)and(ii)to measure the morphology,and size of tools and grinders,processes of truncation and amalgamation in hydro-geomorphic environment using various indices and field techniques.The result showed that large potholes are stretched in the direction of lineament axes and roughly parallel to the river flow direction.Here,the steady growth of pothole depth-diameter is controlled by active bedrock structures,tools,or grinders,and monsoonal high-velocity bank full discharge.Consequently,the deepening and widening of potholes are relatively slow at Bindu,Deuli,and marine beach Neil Island due to fewer structures and little supply of tools or grinders.In small stretches,(Damodar,Subarnarekha,and Rarhu)canyons and gorge-like features(bedrock incision)are formed at Rajrappa,Bhakuyadi,and Guridih sites due to cyclic truncation and amalgamation.Truncation and amalgamation processes restrict the vertical depth threshold value of potholes within 3m,particularly at Rajrappa,Bhakuyadi,and Guridih sites.Scientific study of the pothole's dynamic growth is greatly necessary for the different environmental engineering and river hydraulic projects like excavation,dredging,and dam or barrage construction.Successively,it is essential to compute the cost of rock excavation or dredging,primarily for the mechanical strength of the bedrock river channel and its stability.展开更多
Cleanliness control of advanced steels is of vital importance for quality control of the products.In order to understand and control the inclusion removal during refining process in molten steel,its motion behaviors a...Cleanliness control of advanced steels is of vital importance for quality control of the products.In order to understand and control the inclusion removal during refining process in molten steel,its motion behaviors at the multiple steel/gas/slag interfaces have attracted the attention much of metallurgical community.The recent development of the agglomeration of non-metallic inclusions at the steel/Ar and steel/slag interfaces has been summarized,and both the experimental as well as theoretical works have been surveyed.In terms of in situ observation of high-temperature interfacial phenomena in the molten steel,researchers utilized high-temperature confocal laser scanning microscopy to observe the movement of more types of inclusions at the interface,i.e.,the investigated inclusion is no longer limited to Al_(2)O_(3)-based inclusions but moves forward to rare earth oxides,MgO-based oxides,etc.In terms of theoretical models,especially the model of inclusions at the steel/slag interface,the recent development has overcome the limitations of the assumptions of Kralchevsky-Paunov model and verified the possible errors caused by the model assumptions by combining the water model and the physical model.Last but not least,the future work in this topic has been suggested,which could be in combination of thermal physical properties of steels and slag,as well as utilize the artificial intelligence-based methodology to implement a comprehensive inclusion motion behaviors during a comprehensive metallurgical process.展开更多
High-temperature confocal laser scanning microscopy(HT-CLSM)is a robust characterization tool which can provide in situ real-time studies of materials processing.This facility has been applied in investigating interfa...High-temperature confocal laser scanning microscopy(HT-CLSM)is a robust characterization tool which can provide in situ real-time studies of materials processing.This facility has been applied in investigating interfacial phenomena in ironmaking and steelmaking as well as phase transformations during heat treatment of metallic materials.The pioneering work on the application of HTCLSM dates back to twenty-five years ago,to directly observe the crystallization of undercooled steel melt.展开更多
Hepatocellular carcinoma(HCC) is one of the most common malignancies leading to high mortality rates in the general population and the sixth most common cancer worldwide. HCC is characterized by deregulation of multip...Hepatocellular carcinoma(HCC) is one of the most common malignancies leading to high mortality rates in the general population and the sixth most common cancer worldwide. HCC is characterized by deregulation of multiple genes and signalling pathways. These genetic effects can involve both protein coding genes as well as non-coding RNA genes. Long noncoding RNAs(lnc RNAs) are transcripts longer than 200 nt, constituting a subpopulation of nc RNAs. Their biological effects are not well understood comparedto small non-coding RNA(micro RNAs), but they have been recently recognized to exert a crucial role in the regulation of gene expression and modulation of signalling pathways. Notably, several studies indicated that lnc RNAs contribute to the pathogenesis and progression of HCC. Investigating the molecular mechanisms underlying lnc RNAs expression opens potential applications in diagnosis and treatment of liver disease. This editorial provides three examples(MALAT-1 metastasis associated lung adenocarcinoma transcript, HULC highly upregulated in liver cancer and HOTAIR HOX transcript antisense intergenic RNA) of well-known lnc RNAs upregulated in HCC, whose mechanisms of action are known, and for which therapeutic applications are delineated. Targeting of lnc RNAs using several approaches(siR NA-mediated silencing or changing their secondary structure) offers new possibility to treat HCC.展开更多
Laser cladding of powder mixture of TiN and SS304 is carried out on an SS304 substrate with the help of fibre laser.The experiments are performed on SS304,as per the Taguchi orthogonal array(L^(16))by different combin...Laser cladding of powder mixture of TiN and SS304 is carried out on an SS304 substrate with the help of fibre laser.The experiments are performed on SS304,as per the Taguchi orthogonal array(L^(16))by different combinations of controllable parameters(microhardness and clad thickness).The microhardness and clad thickness are recorded at all the experimental runs and studied using Taguchi S/N ratio and the optimum controllable parametric combination is obtained.However,an artificial neural network(ANN)identifies different sets of optimal combinations from Taguchi method but they both got almost the same clad thickness and hardness values.The micro-hardness of cladded layer is found to be6.22 times(HV_(0.5)752)the SS304 hardness(HV_(0.5)121).The presence of nitride ceramics results in a higher micro hardness.The cladded surface is free from cracks and pores.The average clad thickness is found to be around 0.6 mm.展开更多
AIM:To investigate the effect of lifestyle interventions in the non-pharmacological management of type 2 diabetes via a mechanistic approach.METHODS:A randomized controlled trial was carried out on 60 type 2 diabetic ...AIM:To investigate the effect of lifestyle interventions in the non-pharmacological management of type 2 diabetes via a mechanistic approach.METHODS:A randomized controlled trial was carried out on 60 type 2 diabetic male and female volunteers that fulfilled the inclusion criteria,with their proper consent and permission of the International Electrotechnical Commission for 1 year.30 patients were included in the test group and 30 patients in the control group.Demographic details,anthropometrical status,physical activity,food habits and blood glucose lipid profile of the volunteers were recorded at baseline,the test group was directed for lifestyle intervention and final blood glucose lipid data were collected at the end of one year of patient follow-up.RESULTS:After 1 year,the test group who had a lifestyle intervention was found to show a significant improvement in blood glucose lipid profile.The fasting plasma glucose level(FPG),postprandial plasma glucose level(PPG),glycosylated hemoglobin(HbA1c) and body mass index(BMI) values of the test group were reduced significantly,up to 145 ± 2.52,174 ± 2.59,6.3 ± 0.32 and 25 ± 0.41 respectively at the end of the study period,in comparison to the control group whereFPG,PPG,HbA1c and BMI values were 193 ± 3.36,249 ± 4.24,7.2 ± 0.42 and 26 ± 0.65 respectively.Improvement in the total cholesterol(TC),triglyceride(TG),high-density lipoproteins(HDL) and low-density lipoproteins(LDL) values of the test group was also remarkable in comparison to the control group.The TC,TG,HDL and LDL values of the test group were reduced significantly,up to 149 ± 3.32,124 ± 2.16,58 ± 0.62 and 118 ± 2.31,respectively.CONCLUSION:The significant improvement in the blood glucose lipid profile of the test group after 1 year signifies the value of non-pharmacological management of type 2 diabetes via lifestyle intervention strategies.展开更多
Coal is the world＇s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-.grade coal for fulfilling energy dem...Coal is the world＇s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-.grade coal for fulfilling energy demands of modern civilization. However, due to ItS high ash and moisture content, low-grade coal exerts the substantial impact on their consumption like pyrolysis, liquefaction, gasification and combus- tion process. The present research aimed to develop the efficient technique for the production of clean coal by optimizing the operating parameters with the help of response surface methodology. The effect of three independent variables such as hydrofluoric acid （HF） concentration （10-20% by vo!ume ）,. temper- ature （60-100 ~C）, and time （90-180 min）, for ash reduction from the low-grade coal was Investigated.. A quadratic model was proposed to correlate the independent variables for maximum ash reduction at the optimum process condition by using central composite design （CC.D）method. The study reveals that HF concentration was the most effective parameter for ash reduction in comparison with time and temper- ature. It may be due to the higher F-statistics value for HF concentration, which effects to large extent of ash reduction. The characterization of coal was evaluated by Fourier transform infrared spectroscopy （FTIR） analysis and Field-emission scanning electron microscopy with energy-dispersive X-ray （FESEM- EDX） analysis for confirmation of the ash reduction.展开更多
In marine application,marine grade steel is generally used for haul and superstructures.However,aluminum has also become a good choice due to its lightweight qualities,while rusting of aluminum is minimal compared to ...In marine application,marine grade steel is generally used for haul and superstructures.However,aluminum has also become a good choice due to its lightweight qualities,while rusting of aluminum is minimal compared to steel.In this paper a study on friction stir welding of aluminum alloys was presented.The present investigation deals with the effects of different friction stir welding tool geometries on mechanical strength and the microstructure properties of aluminum alloy welds.Three distinct tool geometries with different types of shoulder and tool probe profiles were used in the investigation according to the design matrix.The effects of each tool shoulder and probe geometry on the weld was evaluated.It was also observed that the friction stir weld tool geometry has a significant effect on the weldment reinforcement,microhardness,and weld strength.展开更多
The effect of sintering temperature on the densification mechanisms, microstructural evolution and mechanical properties of spark plasma sintered （SPS） compacts of a gas atomized Al-4.5 wt.%Cu alloy was investigated...The effect of sintering temperature on the densification mechanisms, microstructural evolution and mechanical properties of spark plasma sintered （SPS） compacts of a gas atomized Al-4.5 wt.%Cu alloy was investigated. The powder particles whose size varied between 10 to 500μm was subjected to SPS at 400, 450 and 500℃ at a pressure of 30 MPa. The compact sintered at 500℃ exhibited fully dense microstructure which was characterized by a uniform distribution of the secondary phase, free of dendrites and micro-porosity. Microscopy and the SPS data reveal that the events such as particle rearrangement, localized deformation and bulk deformation appear to be the sequence of sintering mechanisms depending on the size range of powder particles used for consolidation. The compact sintered at 500℃ exhibited the highest hardness and compression strength since the microstructure was characterized by fine distribution of precipitates, large fraction of submicron grains and complete metallurgical bonding.展开更多
Thermal annealing effects on gamma irradiated Ni/4 H-SiC Schottky barrier diode(SBD) characteristics are analyzed over a wide range of temperatures(400–1100 °C). The annealing induced variations in the concentra...Thermal annealing effects on gamma irradiated Ni/4 H-SiC Schottky barrier diode(SBD) characteristics are analyzed over a wide range of temperatures(400–1100 °C). The annealing induced variations in the concentration of deep level traps in the SBDs are identified by thermally stimulated capacitance(TSCAP). A little decrease in the trap density at E_C – 0.63 eV and E_C –1.13 eV is observed up to the annealing temperature of 600 °C. Whereas, a gamma induced trap at E_C – 0.89 eV disappeared after annealing at 500 °C, revealing that its concentration(< 1013 cm-3) is reduced below the detection limit of the TSCAP technique.The electrical characteristics of irradiated SBDs are considerably changed at each annealing temperature. To understand the anomalous variations in the post-annealing characteristics, the interface state density distribution in the annealed SBDs is extracted.The electrical properties are improved at 400 °C due to the reduction in the interface trap density. However, from 500 °C, the electrical parameters are found to degrade with the annealing temperature because of the increase in the interface trap density.From the results, it is noted that the rectifying nature of the SBDs vanishes at or above 800 °C.展开更多
基金supported by the DST-SERB and VSSC,ISRO of the project titled“Functionality Enhancement through Design and Development of Advanced Finite Element Algorithms for STR tools”under IMPRINT.IIC(IMP/2019/000276)scheme.
文摘Rubber-like materials that are commonly used in structural applications are modelled using hyperelastic material models.Most of the hyperelastic materials are nearly incompressible,which poses challenges,i.e.,volumetric locking during numerical modelling.There exist many formulations in the context of the finite element method,among which the mixed displacementpressure formulation is robust.However,such a displacement-pressure formulation is less explored in meshfree methods,which mitigates the problem associated with mesh distortion during large deformation.This work addresses this issue of alleviating volumetric locking in the element-free Galerkin method(EFGM),which is one of the popular meshfree methods.A two-field mixed variational formulation using the perturbed Lagrangian approach within the EFGM framework is proposed for modelling nearly incompressible hyperelastic material models,such as Neo-Hookean and Mooney-Rivlin.Taking advantage of the meshless nature of the EFGM,this work introduces a unique approach by randomly distributing pressure nodes across the geometry,following specific guidelines.A wide spectrum of problems involving bending,tension,compression,and contact is solved using two approaches of the proposed displacement-pressure node formulation involving regular and irregular pressure node distribution.It is observed that both approaches give accurate results compared to the reference results,though the latter offers flexibility in the pressure nodal distribution.
文摘Electric vehicle(EV) drive trains are constantly subjected to an imbalance between demanded torque and generated electromagnetic torque due to unpredictable terrain, traffic, and other external factors. This imbalance leads to significant torsional vibrations and speed fluctuations, which not only compromise passenger comfort but also exert additional mechanical stress on the EVs. Conventional sensorless methods offer speed estimation and control;however, they provide suboptimal performance with sudden load torque disturbances and operational uncertainties, especially at low speeds and across diverse real-world driving cycles. To address these challenges and improve system robustness, this work proposes an advanced sensorless integral sliding mode control(ASISMC) that enhances performance under diverse operating conditions. The proposed ASISMC methodology shows robust performance across a wide speed range, effectively mitigating abrupt load torque disturbances while minimizing the effect of uncertainties within the system dynamics. The approach is experimentally validated for a wide range of speeds and periodic/non-periodic load torque disturbances. Additional validation through the new European driving cycle(NEDC) and urban dynamometer driving schedule(UDDS) demonstrates the method's effectiveness and reliability in real-world driving conditions.
基金supported by the Ramanujan Fellowship from the Science and Engineering Research Board,Government of India(Grant No.RJF/2022/000115).
文摘This paper introduces dynamic mode decomposition(DMD)as a novel approach to model the breakage kinetics of particulate systems.DMD provides a data-driven framework to identify a best-fit linear dynamics model from a sequence of system measurement snapshots,bypassing the nontrivial task of determining appropriate mathemat-ical forms for the breakage kernel functions.A key innovation of our method is the instilling of physics-informed constraints into the DMD eigenmodes and eigenvalues,ensuring they adhere to the physical structure of particle breakage processes even under sparse measurement data.The integration of eigen-constraints is computationally aided by a zeroth-order global optimizer for solving the nonlinear,nonconvex optimization problem that elicits system dynamics from data.Our method is evaluated against the state-of-the-art optimized DMD algorithm using both generated data and real-world data of a batch grinding mill,showcasing over an order of magnitude lower prediction errors in data reconstruction and forecasting.
基金support from the Anusandhan National Research Foundation(ANRF),erstwhile Science and Engineering Research Board(SERB),India,under the startup research grant program(SRG/2022/000566).
文摘The increasing integration of small-scale structures in engineering,particularly in Micro-Electro-Mechanical Systems(MEMS),necessitates advanced modeling approaches to accurately capture their complex mechanical behavior.Classical continuum theories are inadequate at micro-and nanoscales,particularly concerning size effects,singularities,and phenomena like strain softening or phase transitions.This limitation follows from their lack of intrinsic length scale parameters,crucial for representingmicrostructural features.Theoretical and experimental findings emphasize the critical role of these parameters on small scales.This review thoroughly examines various strain gradient elasticity(SGE)theories commonly employed in literature to capture these size-dependent effects on the elastic response.Given the complexity arising from numerous SGE frameworks available in the literature,including first-and second-order gradient theories,we conduct a comprehensive and comparative analysis of common SGE models.This analysis highlights their unique physical interpretations and compares their effectiveness in modeling the size-dependent behavior of low-dimensional structures.A brief discussion on estimating additional material constants,such as intrinsic length scales,is also included to improve the practical relevance of SGE.Following this theoretical treatment,the review covers analytical and numerical methods for solving the associated higher-order governing differential equations.Finally,we present a detailed overview of strain gradient applications in multiscale andmultiphysics response of solids.Interesting research on exploring the relevance of SGE for reduced-order modeling of complex macrostructures,a universal multiphysics coupling in low-dimensional structures without being restricted to limited material symmetries(as in the case of microstructures),is also presented here for interested readers.Finally,we briefly discuss alternative nonlocal elasticity approaches(integral and integro-differential)for incorporating size effects,and conclude with some potential areas for future research on strain gradients.This review aims to provide a clear understanding of strain gradient theories and their broad applicability beyond classical elasticity.
文摘Background:Acute Myeloid Leukemia(AML)is a highly aggressive clonal hematological malignancy with limited treatment options.This study aimed to evaluate the therapeutic potential of nigericin,a polyether ionophore derived from Streptomyces DASNCL-29,as a mitochondrial-targeted agent for AML treatment.Methods:Nigericin was isolated from Streptomyces DASNCL-29 and characterized via chromatography and NMR.Its cytotoxicity was tested in MOLM13(sensitive and venetoclax-resistant)and HL60(sensitive and cytarabine-resistant)cells using the MTT assay.Mitochondrial dysfunction was assessed by measuring reactive oxygen species(ROS),mitochondrial membrane potential(Δψm),and mitochondrial mass.Apoptosis was evaluated with Annexin V/PI assays and immunoblotting,while proteomic analysis was conducted using Liquid Chromatography-Tandem Mass Spectrometry(LC-MS/MS)to identify differentially regulated proteins.Results:Nigericin demonstrated potent cytotoxicity with IC50 values of 57.02 nM in MOLM13-sensitive,35.29 nM in MOLM13-resistant,20.49 nM in HL60-sensitive,and 1.197 nM in HL60-cytarabine-resistant cells.Apoptosis was confirmed by Annexin V/PI staining and caspase-3/PARP cleavage,along with MCL-1 downregulation.Mitochondrial dysfunction was evident from increased ROS,reducedΔψm,and decreased mitochondrial mass.Proteomic profiling identified 264 dysregulated proteins,including a 3.8-fold upregulation of Succinate Dehydrogenase[Ubiquinone]Flavoprotein Subunit A(SDHA).Conclusion:Nigericin induces apoptosis in AML cells by disrupting mitochondrial function and enhancing oxidative stress.Its nanomolar potency highlights the need for further mechanistic studies and in vivo evaluations to explore its potential in AML treatment.
基金supported by the European Commission(EC)under EC grant agreement 101092386 for the Green-VETAfrica project.
文摘The waste management sector plays a vital role in environmental sustainability and public health.However,it faces significant challenges due to a multi-dimensional skills gap that hinders the effective management,processing and disposal of waste.Effective waste management requires increasing levels of technical expertise,analytical proficiency,behavioural skills and digital competence.However,one critical point of concern is the lack of requisite technical skills required for the optimal operation and maintenance of equipment and machinery used for waste management and disposal.Using desk research and focus group interviews of stakeholders in Nigeria and Ghana,we analyzed the skills gap in the sector in order to identify the skills that are currently short in supply in both countries.Our study revealed three broad skills need areas:(1)Skill requirements for youth employment in the waste management sector;(2)Machineries,technologies and tools used for waste management;and(3)Technical skills requirements for green waste management.The study concludes with a mapping of technologies and skills in the waste management sector while highlighting the impact of the existing skills deficit on the sector’s effectiveness and how it can be addressed through structured technical training programs for stakeholders in the sector.
文摘BACKGROUND Spinal tuberculosis(TB),also known as Pott’s spine,remains a significant global health issue,particularly in regions with a high TB burden.The disease presents complex challenges in diagnosis,management,and treatment,prompting a growing interest in research over recent years.The advancements in imaging,diagnostics,and treatment strategies have driven an increased focus on publishing clinical outcomes,review articles,and case series related to spinal TB(STB).AIM To perform a bibliometric analysis of STB research published over the last 5 years(2019-2023)to identify trends in publication volume,contributions by country,and the nature of the research being conducted.METHODS A comprehensive bibliometric analysis was conducted using the PubMed database,focusing on research articles published between 2019 and 2023.Keywords such as“spine tuberculosis,”“spinal TB,”“TB spine,”and“Pott’s spine”were utilized to capture relevant publications.Articles were analyzed based on the type of research(e.g.,case reports,review articles,cohort studies,randomized controlled trials[RCTs]),number of citations,and country of origin based on the corresponding author's details.Further subgroup analysis was performed according to the TB burden in various countries to assess research trends in high-burden regions.RESULTS A total of 528 articles met the inclusion criteria for this bibliometric analysis.The majority of articles were published between 2020 and 2023(440/528;83.3%),while the lowest number was published in 2019(88/528;16.7%).India led the global contributions with 25.8%of the total publications,followed by China(19.9%)and the United States(10.4%).Combined,African countries contributed 6.8%of the research on STB.Regarding the type of articles,case reports and case series dominated the literature(353/528;66.9%),followed by review articles(120/528;22.7%)and cohort studies(45/528;8.5%).Only 1.9%(10/528)of the studies were RCTs.Countries such as the United States,Germany,the United Kingdom,and Japan have pioneered the use of artificial intelligence(AI)in the diagnostic processes for STB,while India,China,South Africa,and other countries have been pivotal in conducting clinical trials and improving clinical management strategies.CONCLUSION This bibliometric analysis revealed a significant increase in STB research over the last 5 years,with India and China being the leading contributors.However,most publications are case reports or case series,with a limited number of RCTs.The results highlighted the need for more high-quality research,especially in terms of RCTs and innovations in diagnostic technologies.Additionally,the application of AI to STB diagnostics shows promise in developed countries,while high-burden countries are focusing on clinical trials and management strategies.
文摘A total of 393 potholes(368 fluvial and 25 marine potholes)were studied at seven different sites in both the fluvial and marine environments.Diverse bedrock properties and large-scale delivery of tools and grinders regulate the dynamic growth,truncation,and amalgamation of potholes.Therefore,the principal objectives of the study are(i)to examine the relationship between the growth of potholes and substrate lithological with structural characteristics(applying geospatial and Schmidt hammer for rock strength analysis)and(ii)to measure the morphology,and size of tools and grinders,processes of truncation and amalgamation in hydro-geomorphic environment using various indices and field techniques.The result showed that large potholes are stretched in the direction of lineament axes and roughly parallel to the river flow direction.Here,the steady growth of pothole depth-diameter is controlled by active bedrock structures,tools,or grinders,and monsoonal high-velocity bank full discharge.Consequently,the deepening and widening of potholes are relatively slow at Bindu,Deuli,and marine beach Neil Island due to fewer structures and little supply of tools or grinders.In small stretches,(Damodar,Subarnarekha,and Rarhu)canyons and gorge-like features(bedrock incision)are formed at Rajrappa,Bhakuyadi,and Guridih sites due to cyclic truncation and amalgamation.Truncation and amalgamation processes restrict the vertical depth threshold value of potholes within 3m,particularly at Rajrappa,Bhakuyadi,and Guridih sites.Scientific study of the pothole's dynamic growth is greatly necessary for the different environmental engineering and river hydraulic projects like excavation,dredging,and dam or barrage construction.Successively,it is essential to compute the cost of rock excavation or dredging,primarily for the mechanical strength of the bedrock river channel and its stability.
基金the National Natural Science Foundation of China(Grant No.52074179)for the financial supportNational Key Research and Development Program of China(2024YFB3713705)is also acknowledged.
文摘Cleanliness control of advanced steels is of vital importance for quality control of the products.In order to understand and control the inclusion removal during refining process in molten steel,its motion behaviors at the multiple steel/gas/slag interfaces have attracted the attention much of metallurgical community.The recent development of the agglomeration of non-metallic inclusions at the steel/Ar and steel/slag interfaces has been summarized,and both the experimental as well as theoretical works have been surveyed.In terms of in situ observation of high-temperature interfacial phenomena in the molten steel,researchers utilized high-temperature confocal laser scanning microscopy to observe the movement of more types of inclusions at the interface,i.e.,the investigated inclusion is no longer limited to Al_(2)O_(3)-based inclusions but moves forward to rare earth oxides,MgO-based oxides,etc.In terms of theoretical models,especially the model of inclusions at the steel/slag interface,the recent development has overcome the limitations of the assumptions of Kralchevsky-Paunov model and verified the possible errors caused by the model assumptions by combining the water model and the physical model.Last but not least,the future work in this topic has been suggested,which could be in combination of thermal physical properties of steels and slag,as well as utilize the artificial intelligence-based methodology to implement a comprehensive inclusion motion behaviors during a comprehensive metallurgical process.
文摘High-temperature confocal laser scanning microscopy(HT-CLSM)is a robust characterization tool which can provide in situ real-time studies of materials processing.This facility has been applied in investigating interfacial phenomena in ironmaking and steelmaking as well as phase transformations during heat treatment of metallic materials.The pioneering work on the application of HTCLSM dates back to twenty-five years ago,to directly observe the crystallization of undercooled steel melt.
文摘Hepatocellular carcinoma(HCC) is one of the most common malignancies leading to high mortality rates in the general population and the sixth most common cancer worldwide. HCC is characterized by deregulation of multiple genes and signalling pathways. These genetic effects can involve both protein coding genes as well as non-coding RNA genes. Long noncoding RNAs(lnc RNAs) are transcripts longer than 200 nt, constituting a subpopulation of nc RNAs. Their biological effects are not well understood comparedto small non-coding RNA(micro RNAs), but they have been recently recognized to exert a crucial role in the regulation of gene expression and modulation of signalling pathways. Notably, several studies indicated that lnc RNAs contribute to the pathogenesis and progression of HCC. Investigating the molecular mechanisms underlying lnc RNAs expression opens potential applications in diagnosis and treatment of liver disease. This editorial provides three examples(MALAT-1 metastasis associated lung adenocarcinoma transcript, HULC highly upregulated in liver cancer and HOTAIR HOX transcript antisense intergenic RNA) of well-known lnc RNAs upregulated in HCC, whose mechanisms of action are known, and for which therapeutic applications are delineated. Targeting of lnc RNAs using several approaches(siR NA-mediated silencing or changing their secondary structure) offers new possibility to treat HCC.
文摘Laser cladding of powder mixture of TiN and SS304 is carried out on an SS304 substrate with the help of fibre laser.The experiments are performed on SS304,as per the Taguchi orthogonal array(L^(16))by different combinations of controllable parameters(microhardness and clad thickness).The microhardness and clad thickness are recorded at all the experimental runs and studied using Taguchi S/N ratio and the optimum controllable parametric combination is obtained.However,an artificial neural network(ANN)identifies different sets of optimal combinations from Taguchi method but they both got almost the same clad thickness and hardness values.The micro-hardness of cladded layer is found to be6.22 times(HV_(0.5)752)the SS304 hardness(HV_(0.5)121).The presence of nitride ceramics results in a higher micro hardness.The cladded surface is free from cracks and pores.The average clad thickness is found to be around 0.6 mm.
文摘AIM:To investigate the effect of lifestyle interventions in the non-pharmacological management of type 2 diabetes via a mechanistic approach.METHODS:A randomized controlled trial was carried out on 60 type 2 diabetic male and female volunteers that fulfilled the inclusion criteria,with their proper consent and permission of the International Electrotechnical Commission for 1 year.30 patients were included in the test group and 30 patients in the control group.Demographic details,anthropometrical status,physical activity,food habits and blood glucose lipid profile of the volunteers were recorded at baseline,the test group was directed for lifestyle intervention and final blood glucose lipid data were collected at the end of one year of patient follow-up.RESULTS:After 1 year,the test group who had a lifestyle intervention was found to show a significant improvement in blood glucose lipid profile.The fasting plasma glucose level(FPG),postprandial plasma glucose level(PPG),glycosylated hemoglobin(HbA1c) and body mass index(BMI) values of the test group were reduced significantly,up to 145 ± 2.52,174 ± 2.59,6.3 ± 0.32 and 25 ± 0.41 respectively at the end of the study period,in comparison to the control group whereFPG,PPG,HbA1c and BMI values were 193 ± 3.36,249 ± 4.24,7.2 ± 0.42 and 26 ± 0.65 respectively.Improvement in the total cholesterol(TC),triglyceride(TG),high-density lipoproteins(HDL) and low-density lipoproteins(LDL) values of the test group was also remarkable in comparison to the control group.The TC,TG,HDL and LDL values of the test group were reduced significantly,up to 149 ± 3.32,124 ± 2.16,58 ± 0.62 and 118 ± 2.31,respectively.CONCLUSION:The significant improvement in the blood glucose lipid profile of the test group after 1 year signifies the value of non-pharmacological management of type 2 diabetes via lifestyle intervention strategies.
文摘Coal is the world＇s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-.grade coal for fulfilling energy demands of modern civilization. However, due to ItS high ash and moisture content, low-grade coal exerts the substantial impact on their consumption like pyrolysis, liquefaction, gasification and combus- tion process. The present research aimed to develop the efficient technique for the production of clean coal by optimizing the operating parameters with the help of response surface methodology. The effect of three independent variables such as hydrofluoric acid （HF） concentration （10-20% by vo!ume ）,. temper- ature （60-100 ~C）, and time （90-180 min）, for ash reduction from the low-grade coal was Investigated.. A quadratic model was proposed to correlate the independent variables for maximum ash reduction at the optimum process condition by using central composite design （CC.D）method. The study reveals that HF concentration was the most effective parameter for ash reduction in comparison with time and temper- ature. It may be due to the higher F-statistics value for HF concentration, which effects to large extent of ash reduction. The characterization of coal was evaluated by Fourier transform infrared spectroscopy （FTIR） analysis and Field-emission scanning electron microscopy with energy-dispersive X-ray （FESEM- EDX） analysis for confirmation of the ash reduction.
文摘In marine application,marine grade steel is generally used for haul and superstructures.However,aluminum has also become a good choice due to its lightweight qualities,while rusting of aluminum is minimal compared to steel.In this paper a study on friction stir welding of aluminum alloys was presented.The present investigation deals with the effects of different friction stir welding tool geometries on mechanical strength and the microstructure properties of aluminum alloy welds.Three distinct tool geometries with different types of shoulder and tool probe profiles were used in the investigation according to the design matrix.The effects of each tool shoulder and probe geometry on the weld was evaluated.It was also observed that the friction stir weld tool geometry has a significant effect on the weldment reinforcement,microhardness,and weld strength.
文摘The effect of sintering temperature on the densification mechanisms, microstructural evolution and mechanical properties of spark plasma sintered （SPS） compacts of a gas atomized Al-4.5 wt.%Cu alloy was investigated. The powder particles whose size varied between 10 to 500μm was subjected to SPS at 400, 450 and 500℃ at a pressure of 30 MPa. The compact sintered at 500℃ exhibited fully dense microstructure which was characterized by a uniform distribution of the secondary phase, free of dendrites and micro-porosity. Microscopy and the SPS data reveal that the events such as particle rearrangement, localized deformation and bulk deformation appear to be the sequence of sintering mechanisms depending on the size range of powder particles used for consolidation. The compact sintered at 500℃ exhibited the highest hardness and compression strength since the microstructure was characterized by fine distribution of precipitates, large fraction of submicron grains and complete metallurgical bonding.
文摘Thermal annealing effects on gamma irradiated Ni/4 H-SiC Schottky barrier diode(SBD) characteristics are analyzed over a wide range of temperatures(400–1100 °C). The annealing induced variations in the concentration of deep level traps in the SBDs are identified by thermally stimulated capacitance(TSCAP). A little decrease in the trap density at E_C – 0.63 eV and E_C –1.13 eV is observed up to the annealing temperature of 600 °C. Whereas, a gamma induced trap at E_C – 0.89 eV disappeared after annealing at 500 °C, revealing that its concentration(< 1013 cm-3) is reduced below the detection limit of the TSCAP technique.The electrical characteristics of irradiated SBDs are considerably changed at each annealing temperature. To understand the anomalous variations in the post-annealing characteristics, the interface state density distribution in the annealed SBDs is extracted.The electrical properties are improved at 400 °C due to the reduction in the interface trap density. However, from 500 °C, the electrical parameters are found to degrade with the annealing temperature because of the increase in the interface trap density.From the results, it is noted that the rectifying nature of the SBDs vanishes at or above 800 °C.
