Constant Values Research Articles

4'-O-MethylbavachalconeB Targeted 14-3-3ζ Blocking the Integrin β3 Early Outside-In Signal to Inhibit Platelet Aggregation and Thrombosis.

14-3-3ζ protein, the key target in the regulation and control of integrin β3 outside-in signaling, is an attractive new strategy to inhibit thrombosis without affecting hemostasis. In this study, 4'-O-methylbavachalconeB (4-O-MB) in Psoraleae Fructus was identified as a 14-3-3ζ ligand with antithrombosis activity by target fishing combined with ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) analysis. The competitive inhibition analysis showed that 4-O-MB targeted 14-3-3ζ and blocked the 14-3-3ζ/integrin β3 interaction with inhibition constant (Ki) values of 9.98 ± 0.22 μM. Molecular docking and amino acid mutation experiments confirmed that 4-O-MB specifically bound to 14-3-3ζ through LSY9 and SER28 to regulate the 14-3-3ζ/integrin β3 interaction. Besides, 4-O-MB affected the integrin β3 early outside-in signal by inhibiting AKT and c-Src phosphorylation. Meanwhile, 4-O-MB could inhibit ADP-, collagen-, or thrombin-induced platelet aggregation function but had no effect on platelet adhesion to collagen-coated surfaces in vivo. Administration of 4-O-MB could significantly inhibit thrombosis formation without disturbing hemostasis in mice. These findings provide new prospects for the antithrombotic effects of Psoraleae Fructus and the potential application of 4-O-MB as lead compounds in the therapy of thrombosis by targeting 14-3-3ζ.

A Global Seawater Density Distribution Model Using a Convolutional Neural Network.

Seawater density is an important physical property in oceanography that affects the accuracy of calculations such as gravity fields and tidal potentials and the calibration of acoustic and optical oceanographic sensors. In related studies, constant density values are frequently used, which can introduce significant errors. Therefore, this study employs a basic convolutional neural network model to construct a comprehensive model showing the seawater density distribution across the globe. The model takes into account depth, latitude, longitude, and month as inputs. Numerous real seawater datasets were used to train the model, and it has been shown that the model has an absolute mean error and root mean square error of less than 1 kg/m3 in 99% of the test set samples. The model effectively demonstrates the influence of input parameters on the distribution of seawater density. In this paper, we present a newly developed global model for distributing seawater density which is both comprehensive and accurate, surpassing previous models. The utilization of the model presented in this paper for estimating seawater density can minimize errors in theoretical ocean models and serve as a foundation for designing and analyzing ocean exploration systems.

Spatio-temporal analysis of river flow master recession curve characteristics over Ardabil province rivers

The Master Recession Curve (MRC) is a crucial tool for evaluating, managing, and utilizing rivers, particularly under low-flow conditions. Analyzing changes in the MRC of river flow is useful for water resource planning, surface water utilization, and estimating and allocating environmental flow. This study utilized daily flow data from rivers in Ardabil province, Iran over a 48-year statistical period (1970–2015). The Visual Basic program was utilized to estimate the equations and coefficients of recession curves. The trends of the constant and slope coefficients of the MRC equations were determined using the Mann-Kendall test and linear regression. Higher constant coefficient values were attributed to main rivers with higher discharge (e.g., Borran, Mashiran, and Samian, having 17.98, 13.79, and 5.64 cms, respectively. The slope of the MRC in most of the rivers in the central part of the study area exhibited a decreasing trend (p-value<0.05), which attributed to climate change, alterations in precipitation patterns, reduced rainfall/snowmelt, and water abstraction leading to less water input during non-flood periods. Additionally, most rivers in different climatic regions and areas of the study region exhibited an increasing trend (p-value<0.05) in the MRC constants, indicating reduced groundwater recharge or increased groundwater abstraction, as a common issue in the Ardabil province. Moreover, human water use and reservoir regulation (Yamci, Sabalan, Saghezchi, Givi, and small regulating reservoirs) can influence river flow patterns during non-flood periods. The occurrence of droughts and intensified surface water use by farmers, as well as unauthorized extraction of water from wells, have exacerbated this trend.

Samarium(III) Removal by Weak Acid Exchanger Amberlite IRC-50 in (H+) and (Na+) Forms

Adsorption of samarium(III) on a weakly macroporous cation exchanger Amberlite IRC-50 (H+) and (Na+) forms is studied as a function of the initial pH of the aqueous solution, time and temperature, initial samarium(III) ion concentration, and the amount of resin at a fixed temperature (20 ± 1 °C). The concentration range was between 0.1–5 mmol/L, the pH range was between 1.8 and 10.5; the stirring time was between 2 and 60 min; and the amount of resin was between 0.025 and 0.15 g. Both the film and particle diffusion equations are applied to explain the kinetic data. The rate constant values for samarium(III) adsorption were calculated for both film and particle diffusion processes. It is observed to follow the order (Na+) &gt; (H+). Temperature is found to have an insignificant effect on both diffusional processes. Various thermodynamic parameters (ΔH°, ΔS°, and ΔG°) from samarium(III) exchange on the resin were calculated. The optimum conditions were found to be a concentration of 1 mmol/L, pH of 9.3, stirring time of 20 and 5 min for Amberlite IRC-50 (H+) and (Na+) forms, respectively, and 0.15 g of resin. The equilibrium extraction of samarium was 22.2 mg/g for Amberlite IRC-50 (H+) and 21.9 mg/g for Amberlite IRC-50 (Na+) at an initial concentration of 1 mmol/L. The results obtained show that the Amberlite IRC-50 weak cationexchange resin performed well for the removal and recovery of samarium(III). The optimization procedure provides access to industrial-scale Sm(III) removal processing.

Mechanism insight of sorption of Er(III) and Nd(III) ions onto Aluminium barium tungstate synthesized via streamlined sol–gel technique: Time-transient study

Aluminium barium tungstate powder (ABT) was chemically synthesized via streamlined sol–gel technique and exploited as a sorbent material for sorption of erbium and neodymium ions from aqueous solutions under simulated conditions using batch technique. The pH influence, time and temperature factors have been studied. The sorption of neodymium ions was found to be marginally higher than that of erbium ions and the apparent sorption capacity has a progressive influence with temperature. Thermodynamic parameters such as Gibbs free energy change (ΔG◦), enthalpy change (ΔH◦) and entropy change (ΔS◦) were calculated. The negative ΔG◦ values declines with an increase in temperature value, demonstrating that the sorption reaction for both studied ions was spontaneous and more promising at greater temperature. The positive ΔH◦ values affirm that the nature of the sorption processes is endothermic. The comparison of different time transient models applied to the sorption data was assessed for the pseudo first-order (PFO), the pseudo second-order, (PSO) and homogeneous particle diffusion (HPD) models. The results revealed that both PSO and HPD models were found to best correlate the experimental sorption rate data and a monolayer model was adopted as the best suitable model to explore the sorption mechanism for both studied ions. The attained particle diffusion coefficients and rate constant values were acquired from the graphical illustration of the anticipated models. Activation energy change (Ea) and activation entropy change (ΔS±) were also calculated from the linearized Arrhenius model and indicated that the binding process between the sorbent and the studied ions occurred through chemisorption and the sorption of both ions onto synthetic sorbent took place through associative mechanism.

Effects of temperature on the dynamic and static properties of a non-heisenberg anisotropic ferromagnet

In the mean-field approximation, the influence of both temperature and the value of the single-ion anisotropy constant of the “easy axis” type on the phase states and excitation spectra of a non-Heisenberg ferromagnet with S = 1 is studied. The temperature dependences of the vector and tensor order parameters in both the ferromagnetic and nematic phases have been determined. The dependence of excitation spectra on temperature and the value of the anisotropy constant is studied. It is shown that at a temperature different from zero, an additional (non-relaxation) branch of excitations arises in both the ferromagnetic and nematic phases. The temperature dependence of the phase diagram is studied.

Estimating the slip rate in the North Tabriz Fault using focal mechanism data and GPS velocity field

Abstract This study delves into slip distribution on the North Tabriz Fault (NTF), a critical aspect of seismic hazard analysis due to its proximity to the Tabriz metropolis. The study operates within a uniform elastic half-space, maintaining constant values for fault geometry and regional rheological parameters throughout the research. To calculate strain boundary conditions, permanent and periodic global positioning system (GPS) data from the northwest region were utilized. The fault was constrained perpendicularly while allowing tangential movement, facilitating the determination of its annual slip rate using the boundary element method, with the Okada analytical model serving as the fundamental solution. The findings underscore the intricate relationship between the fault’s slip rate and boundary conditions, revealing a predominant right-lateral strike-slip motion. The study offers two slip rate assessments, obtained through earthquake focal mechanisms and GPS velocity data, yielding values of 5 and 5.5 mm / year {\rm{mm}}/{\rm{year}} , respectively. Importantly, the alignment of these calculated slip rates with paleo-seismological data underscores the credibility of the results generated via the boundary element method, distinguishing it as a reliable approach when compared to other numerical and analytical techniques. This research provides valuable insights into the behavior and slip dynamics of the NTF, which is pivotal for assessing seismic risks.

Synthetic exchange coupled composite for widening an in-plane ballistic switching region

This study proposes synthetic exchange coupled composites to control ballistic switching effectively. We performed macrospin simulations for the ballistic switching of in-plane magnetized nanomagnets with varying antiferromagnetic coupling constant. It was discovered that there exists an optimal value of the antiferromagnetic coupling constant at which the ballistic switching region can be widened to 3.3 times of that of the single hard nanomagnet, where the antiferromagnetic coupling field torque significantly counteracts the demagnetizing field torque of the hard nanomagnet. The ballistic switching region is also effectively widened due to the volume-averaging of saturation magnetizations; that is, the cancelation of demagnetizing fields at the large antiferromagnetic coupling beyond the optimal value.

Optimized Schwarz Waveform Relaxation method for the incompressible Stokes problem

We propose and analyse the optimized Schwarz waveform relaxation (OSWR) method for the unsteady incompressible Stokes equations. Well-posedness of the local subdomain problems with Robin boundary conditions is proved. Convergence of the velocity is shown through energy estimates; however, pressure converges only up to constant values in the subdomains, and an astute correction technique is proposed to recover these constants from the velocity. The convergence factor of the OSWR algorithm is obtained through a Fourier analysis, and allows to efficiently optimize the space-time Robin transmission conditions involved in the OSWR method. Then, numerical illustrations for the two-dimensional unsteady incompressible Stokes system are presented to illustrate the performance of the OSWR algorithm.

Highly emissive pyrrolo[1,2-a]quinoxaline based narrow band fluorescent sensors for detection of nitroaromatics and their application in spot paper test

In the modern day, explosive detection is essential to public safety, and fluorescent small molecules have gained popularity for their quick and accurate detection. Herein, we present the design and synthesis of a series of pyrrolo[1,2-a]quinoxaline-based conjugated small organic fluorophores (PQ-Ph-OH, PQ-Ph-NMe, PQ-Ph-OMe, PQ-Ph-Me, and PQ-Ph-CN) as fluorescence-based sensors for explosive molecules. The sensor molecules were synthesized in good to excellent yields using a dehomologative functionalization strategy. They exhibited excellent photophysical characteristics, which was tunable based on the substituent on the phenyl linker at position 3. DFT studies showed that the pyrroloquinoxaline moiety could act as an on-demand electron donor or acceptor, depending on the phenyl substituent. The molecules also exhibited solid state emission due to twisted geometry around the CC single bond between the heterocyclic scaffold and the phenyl derivative. This resulted in low band intense emission for the synthesized molecules. In the presence of electron-deficient nitroaromatic explosives, all the fluorophores showed excellent fluorescence quenching. Detection limits in the range of 10−4 M were obtained for all the fluorophores. Stern-Volmer plots show high values of binding constants, indicating good interaction between the fluorophores and the explosive molecules. The mechanism of sensing was confirmed by UV-PL spectral overlap and fluorescence lifetime measurements, which suggest a static quenching based on the formation of a ground state complex. Owing to solid state emissions in some of the derivatives, the synthesized molecules were applied to paper strips for spot detection of explosive molecules.

Exploring the influence of pressure-induced semiconductor-to-metal transition on the physical properties of cubic perovskites FrXCl3 (X = Ge and Sn)

Even though lead halide perovskites have outstanding physiochemical properties and improved power conversion efficiency, most of these compounds threaten their future commercialization because of their instability and highly toxic nature. Thus, it is preferable to use stable alternative elements rather than lead to make environmentally friendly perovskite material that will have comparable optical and electronic properties to those constructed from Pb-based perovskites. However, devices constructed from lead-free perovskites typically display a lower power conversion efficiency. Applying hydrostatic pressure could be deemed an effective method to alter the physical properties of these compounds. This not only improves their performance in application but also reveals significant correlations between structure and properties. This work uses DFT to investigate the structural, electronic, optical, and elastic properties of non-toxic, francium-based halide perovskites FrXCl3 (X = Ge, Sn) at different levels of hydrostatic pressures that vary from 0 to 10 GPa. The estimated structural parameter's strong correlation with the data from earlier studies ensures the accuracy of the current findings. Pressure causes the Fr−Cl and Ge (Sn)–Cl bonds to shorten and become stronger. The electronic property calculations demonstrated that both compounds are direct band-gap semiconductors. The application of pressure leads to a linear reduction in the band gap (semiconducting to metallic state) and raises the electronic density of states around the Fermi level by forcing the valence band electrons upward, indicating that the optoelectronic device's performance can be tuned and improved. The values of the dielectric constant, absorptivity and reflectivity showed an increasing tendency with pressure. As the pressure applied to the compounds increases, the absorption spectra show a redshift. These findings suggested that the FrXCl3 (X = Ge and Sn) compound becomes more appropriate for usage in optoelectronic applications under pressure. Furthermore, our examination of the mechanical properties indicates that both FrGeCl3 and FrSnCl3 exhibit mechanically stability, and ductility. Interestingly, we observe an increase in ductility as pressure levels rise.

Mechanism of formation of p-benzylenephenol peroxide radical (p-PhC(O2•)HPhOH).

The reactions of radicals with O2 play the important role in the biological, medicinal, and industrial processes. The mechanism of this reaction is studied previously for the alkane, alkene, alkyne, phenols, and close-related radicals. According to these studies, the formation of intermediates in these reactions is predicted only for the aromatic radicals. Thus, the Van der Waals complexes of O2 with phenyl or benzyl radicals are predicted, as well as the π-π cluster for benzene. However, the possibility of the formation of such intermediate π-π clusters in the case of bisphenol radicals and the thermochemistry of its formation is not studied. Bisphenols are one of the main components of bio-oil, produced during pyrolysis of lignin-contained biomass. Synthetic bisphenols are used in polycarbonate plastics, epoxy resins, and thermal papers. Their mechanism of oxidation is important for the determination of fire safety of these materials, the possibility of using them as additives for fuels for the decreasing and the description of the ignition delays, as well as for the determination of its health risk assessment in medicine. The five DFT (M06-2X (i = 1), B3LYP (i = 2), wB97XD (i = 3), M08HX (i = 4), MN15 (i = 5)) approaches with 6-311 + + G(d,p) basis set are used for the determination of standard enthalpies of atomization (ΔraHo(Yi)) of considered compounds (molecules, radicals, and transition states). These values of ΔraHo(Yi) are corrected using the empirical linear calibration dependencies, reported previously. The different calibration dependencies are used for the hydrocarbons (including the aromatics and simple oxygenated derivatives) and for the peroxides. The corrected values of ΔraHo(Yi, CORR) are used according to Hess's law for the determination of ΔfHo(Yi, CORR). The most consistent values of ΔfHo(Y, MEAN) are derived from the coordination of the values of ΔfHo(Yi, CORR) using the intersection of their values of standard deviations (3SDi). These values of ΔfHo(Y, MEAN), as well as the B3LYP values of So(Y), which are accounting the frequency correction and internal rotations, as well as their temperature dependencies, are used for the determination of thermochemistry of considered reactions and of the calculation, within transition state theory (TST), of the values of high-pressure limits of the rate constant. The values of Ho(Yi), So(Yi), and Go(Yi) are calculated using the Gaussian 16w program. The temperature dependencies of thermochemical properties and the values of rate constants are determined using the ChemRate program (v.1.5). The optimized structures are visualized using the Chemcraft.

Frequency-based electric fingerprint and thermal properties of the NWA 869 chondrite

The NWA 869 chondrite is among many common stony regolith breccia meteorites that have been collected from northwest Africa (NWA). It is composed of Fe sulphide and Fe-Ni metallic phase inclusions embedded in a silicate stony matrix (primarily pyroxene). Although the physical properties of meteorites are the implementation of their mineral and chemical compositions, their electric and dielectric properties (electric conductivity σ, dielectric constant ε′, and dielectric loss ε") are rarely studied, while no literature has been published on their thermal properties (thermal conductivity K, thermal diffusivity α, specific heat capacitance Cp, and thermal effusivity e). Consequently, the present study deals with studying the electric and dielectric properties of the NWA 869 chondrite at a frequency range (4.0 Hz-8.0 MHz), and their behavior against the applied frequency (fingerprint) was matched. Also, the thermal properties were measured at the ambient conditions. The porosity and density of the chondrite were also measured using helium injection technique. To explain the electric and thermal properties of the meteorite sample, its internal structure as well as its mineral and chemical compositions were revealed using the environmental Scanning electron microscopy (ESEM) supported by the EDAX technique. It is indicated that the chondrite is composed of iron sulphide and Fe-Ni inclusions scattered in a stony silicate matrix; it is characterized by moderate density (3.5069 g/cc) with a considerable porosity value (2.12 %). It is also characterized by moderate electric conductivity (σ), dielectric constant (ε′), and dielectric loss (ε") values (0.50 < σ < 2037.3 ohmm, 67.0 < ε' < 1713.7, and 0.22 < ε" < 12,432 at frequency range 4 Hz-8MHz, respectively). Also, it is characterized by thermal conductivity (K), thermal diffusivity (α), thermal capacitance (Cp), and thermal effusivity (e) values of average 1.5185 W/(K.m), 1.5425 mm2/s, 286 J/(K.kg), and 2628 W(s)0.5/m2K, respectively.

Photocatalytic dye degradation and hydrogen peroxide sensing by a novel copper-Schiff base complex prepared via mechanochemical method

ABSTRACT Water pollution, primarily caused due to hazardous organic and inorganic substances, is a cause of concern for human health and development, for it manifests adverse repercussions across health, economic, and social dimensions. The footprints of its adverse effects are also left on aquatic/marine life forms. In the light of the negative impacts of such substances, the development of efficient remediation techniques becomes pertinent. In this article, we report a water-soluble glutamic acid Schiff base copper complex (Cu-GSb) that has been synthesised by taking recourse to a mechanochemical approach, relying upon solid-state reagent interactions in a benign environmental setting, eluding a rigorous refluxing condition and overuse of solvents. The experimental results revealed that the ligand coordinates to the metal centre in a bidentate fashion through the imine nitrogen and carboxylate oxygen, respectively, adopting a distorted square planar geometry. Further, the complex’s utility in mitigating chemical hazards has been demonstrated through the studies involving degradation of organic dyes like methylene blue and bromocresol green, and decomposition/sensing of H2O2. Notably, as a photocatalyst towards the degradation of above-mentioned dyes under visible light irradiation, our study showed the photocatalytic efficiency of Cu-GSb to be ~95% in 50–60 min. The rate of degradation reaction has been found to follow first-order kinetics with rate constant values of 6 × 10−2 and 5.66 × 10−2 min−1 for MB and BCG, respectively. Furthermore, the results of H2O2 sensing evaluation revealed that the complex is capable of potentially decomposing H2O2 in about 20–30 min. The compounds have been routinely characterised by UV–visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and proton nuclear magnetic resonance (1H NMR).

AnMePa: development of a new method for preparing trousers pattern by using the antropometric measurement system

PurposeThis study establishes the principles and process steps of a new basic trousers pattern using measurements obtained according to the rules of the anthropometric measurement system. The newly developed pattern-making system in this study will be called the “Anthropometric Measurements Based Pattern Making System” (AnMePa). It is aimed at producing trousers that are more fitting to the body, thanks to this pattern-making system.Design/methodology/approachIn this research, four pattern-making systems used in many parts of the world were compared with the “Anthropometric Measurements Based Pattern Making System” (AnMePa) with regard to the overall appearance and body fit of trousers prepared according to these systems. 10 virtual mannequins (VM) with different adult female body measurements were created, and trousers patterns were prepared for these mannequins. The trousers’ patterns were made and dressed on the mannequins in a 3D virtual dressing system. The body fit of the virtual garments was evaluated by five experts. The scores given by the experts were evaluated using the fuzzy logic method.FindingsAccording to the results, it is seen that the new basic trousers pattern developed by utilizing the anthropometric measurement system, AnMePa, provides the best body fit among the basic trousers patterns created according to the other examined pattern-making systems. The combination of 3D virtual dressing and fuzzy logic in the evaluation of garment body fit is considered an innovative method for the future of fashion design and production.Originality/valueIn the developed AnMePa, unlike the existing pattern-making systems, values that can be associated with the body measurements of individuals in a way that could be suitable for each community were used instead of constant values in the pattern-making process. Furthermore, the integration of 3D virtual fitting and fuzzy logic in assessing garment fit is considered a pioneering approach with significant implications for the future landscape of fashion design and production.

The Polya f-curvature of plane curves

We introduce and study a new curvature function for plane curves inspired by the weighted mean curvature of M. Gromov. We call it Pólya, being the difference between the usual curvature and the inner product of the normal vector field with the Pólya vector field of a given planar function f. We computed it for several examples, since the general problem of vanishing or constant values of this new curvature involves the general expression of f. Mathematics Subject Classification (2010): 53A04, 53A45, 53A55. Received 03 May 2023; Accepted 17 January 2024

A DFT study for physical properties and hydrogen storage capability of indium-based hydride perovskites XInH3 (X = Li, K) for hydrogen storage application

The physical properties and hydrogen storage capability of indium-based hydride perovskites XInH3 (X = Li, K) have been assessed in the present study. The HSE06 hybrid functional inside the CASTEP code based on DFT is used for the investigation of both materials. Both the compounds are found thermodynamically stable which is confirmed by the phonon dispersion curves. The negative values of the cohesive energy also show that both the materials are thermodynamically stable. Both the materials have zero band gap and possess metallic nature with the lattice constant values of 4.37 and 4.32 Å for LiInH3 and KInH3, respectively. The spin polarized band structure and density of states show that both the materials have antiferromagnetic nature. The optical properties show that both materials have a higher absorption and conductivity in the lower energy region. LiInH3 possesses higher values of static reflectivity and refractive index than KInH3. Both the materials are found mechanically stable, anisotropic, hard, and ductile in nature. The value of gravimetric ratio is found to be 2.42% and 1.92% for LiInH3 and KInH3, respectively. Both the materials can store sufficient hydrogen, however, LiInH3 is recommended as a preferred material for hydrogen storage application.

Calculation of Homogenized Mechanical Coefficients of Fiber-Reinforced Composite Using Finite Element Method.

Determining the mechanical properties of a composite material represents an important stage in its design and is generally a complicated operation. These values are influenced by the topology and geometry of the resulting composite and the values of the elastic constants of the components. Due to the importance of this subject and the increasing use of composite materials, different calculation methods have been developed over the last fifty years. Some of the methods are theoretical, with results that are difficult to apply in practice due to difficulties related to numerical calculation. In the current paper, using theoretical results offered by the homogenization theory, values of engineering elastic constants are obtained. The finite element method (FEM) is used to determine the stress and strain field required in these calculations; this is an extremely powerful and verified calculation tool for the case of a material with any type of structure and geometry. In order to minimize errors, the paper proposes the method of least squares, a mathematical method that provides the best estimate for the set of values obtained by calculating FEM. It is useful to consider as many load cases as possible to obtain the best estimates. The elastic constants for a transversely isotropic material (composite reinforced with cylindrical fibers) are thus determined for a real case.

Mineralogical and magnetic variations of periglacial loess in SE Tibet reveal mid-Pleistocene expansion of Tibetan glacial activity

The formation and evolution of the cryosphere on the Tibetan Plateau is of great significance in understanding the Earth's carbon and climatic system. Periglacial loess deposits in southeastern Tibet offer a means to constrain this history as they contain critical information on glacial grinding and frost shattering processes in high-altitude mountain regions through time, which yield lithogenic fractions of largely loess silts and sands. Based on combined analyses of lithogenic magnetic properties and mineralogical composition, here we find that increasing high mountain production and supply of fresh detrital components since the mid-Pleistocene climate transition (MPT, 1.2–0.7 Ma) led to a substantial increase of the lithogenic susceptibility and decrease in chemical weathering intensity of periglacial loess in southeastern Tibet. The agreement of these findings with similar results from eolian loess on the northern margins of the Tibetan Plateau suggests a plateau-wide glacier expansion during the MPT. Enhanced glacial erosion and freeze-thaw activities occurred in the high-altitude mountain regions of the plateau during the MPT, thereby providing vast amounts of fresh detritus for the formation of loess deposits. High and constant values of lithogenic magnetic parameters in the loess deposits after 0.7–0.6 Ma further indicate that the Middle Pleistocene is a critical period for the establishment of modern-like glacial and periglacial landforms on the Tibetan Plateau. Our results further suggest that enhanced Quaternary glaciation in SE Tibet occurred earlier than in the north, which we attribute to climate cooling combined with regional seasonal snowline lowering. As such, a close relationship exists between global climate changes, development of pan-Tibetan glaciations, and large-scale dust emission.

Combined force decomposition approach and CFD simulation methods for 2D water entry and exit problem

The force decomposition approach is extended to solve the two-dimensional (2D) water entry and exit problems. Two typical scenarios, direct water exit and continuous water entry and exit, are examined. It reveals that the total force is irrelevant to the body velocity but to the acceleration. More specifically, the force can be expressed as the multiplication of constant values, body acceleration and a non-dimensional coefficient, and the coefficient is related only to the displacement and immersion condition of the body while independent of its motion condition. Two typical body shapes, a widely used wedge model and a practical ship section model, are examined here. CFD simulation is employed here to directly extract the non-dimensional coefficients, which avoids complex calculations for the wetted length of body by analytical models. The force decomposition approach with the obtained coefficients provides a means to quickly and accurately predict the hydrodynamic force acting on body for water exit scenarios. The proposed method is verified by comparing its results with CFD simulations in the complicated motion cases with varying acceleration. Furthermore, this work provides a potential tool to calculate the total force acting on any entire 3D hull that is divided into several independent 2D slices.