Relative Magnitude Research Articles

Genetics of Fruit Yield and Its Traits in Okra [Abelmoschus esculentus (L.) Moench

A Half-diallel mating design involving nine okra genotypes was used to study the inheritance of fruit yield and its component characters in okra. Data from the F1 generation and parents were analysed using Hayman's (1954) method of diallel analysis. The estimated component of genetic variation revealed that additive component (D) was significant for number of branches per plant and fruit girth in E1 and fruit girth in E3 environment. However, additive component was non-significant in all three environments for fruit yield per plant. The dominant components (H1 and H2) were significant for all the characters in all the environments. These results revealed the importance of both additive and non-additive component of gene action in the expression of traits under study. The relative magnitude of dominant component (H1 and H2) was higher than additive component for most of the traits indicating that dominance gene action involved in expression of most of the characters under studied. The average degree of dominance for fruit yield per plant and most of the traits was more than unity in all the three environments which suggested over dominance effect in expression of all the traits. The proportion of genes with positive and negative effects in parents was deviated from 0.25 in all three environments suggesting asymmetrical distribution of positive as well as negative alleles among the parents for fruit yield per plant. The ratio of dominant and recessive genes in the parents were also greater than unity in all the three environments, indicated excess of dominant genes were present in the parents for fruit yield per plant. In the presence of overdominance for yield, reciprocal recurrent selection is the best recurrent scheme to develop hybrids.

Genetic Component Analysis in Fruit Yield and Quality Traits in Okra [Abelmoschus esculentus (L.) Moench

A half-diallel cross involving nine okra genotypes was utilized to investigate the inheritance of fruit yield and its component traits. Data from the F1 generation and the parent genotypes were analysed using Hayman's (1954) diallel method. The additive genetic component (D) was found to be significant for the traits like days to last picking in environment E1, and for the number of fruits per plant in environments E2 and E3, but non-significant across all environments for fruit yield per plant. The dominant components (H1 and H2) were found significant for all traits studied under all environmental condition. This revealed that both additive and non-additive gene actions play a vital role in the expression of the traits studied. The dominant component's (H1 and H2) relative magnitude was greater than the additive component for most of the traits, suggesting the importance of dominance effects on expression of those traits. The average degree of dominance showed an overdominance effect for the traits studied. The ratio of dominant to recessive genes indicated that the parents had an excess of dominant genes for fruit yield per plant. Thus stated the presence of overdominance for yield, reciprocal technique is the most effective recurrent breeding scheme for producing improved hybrids.

Numerical study on the polarity change process during internal wave shoaling

Polarity change is an important mechanism for internal waves shoaling. In this study, a numerical model for simulating the real-scale internal wave passing over slope-shelf topography is established based on the Fourier pseudo-spectral method and weakly nonlinear theory. By numerical simulation, the effects of shelf height, initial wave amplitude, and inclination angle on the waveform characteristics and energy properties of the internal wave during its shoaling are investigated. In the polarity change process, the initial internal wave converts into a depression wave and a generated elevation wave behind it. The distance between the peak of the elevation wave and the trough of the depression wave is a key feature to describe the polarity change. In terms of energy properties, the energy ratio of depression and generated elevation waves compared with the initial wave as well as their relative magnitude is mainly determined by the shelf height. In addition, the initial wave amplitude also affects the generation of the elevation wave and the attenuation of the depression wave to a certain extent. The increase in the inclination angle hinders the formation of the elevation wave but has little effect on the depression wave energy.

Relating Quartz Crystallographic Preferred Orientation Intensity to Finite Strain Magnitude in the Northern Snake Range Metamorphic Core Complex, Nevada: A New Tool for Characterizing Strain Patterns in Ductilely Sheared Rocks

AbstractDocumenting the magnitude of finite strain within ductile shear zones is critical for understanding lithospheric deformation. However, pervasive recrystallization within shear zones often destroys the deformed markers from which strain can be measured. Intensity parameters calculated from quartz crystallographic preferred orientation (CPO) distributions have been interpreted as proxies for the relative strain magnitude within shear zones, but thus far have not been calibrated to absolute strain magnitude. Here, we present equations that quantify the relationship between CPO intensity parameters (cylindricity and density norm) and finite strain magnitude, which we calculate by integrating quartz CPO analyses (n = 87) with strain ellipsoids from stretched detrital quartz clasts (n = 49) and macro‐scale ductile thinning measurements (n = 7) from the footwall of the Northern Snake Range décollement (NSRD) in Nevada. The NSRD footwall exhibits a strain gradient, with Rs(XZ) values increasing from 5.4 ± 1.4 to 282 ± 122 eastward across the range. Cylindricity increases from 0.52 to 0.83 as Rs increases from 5.4 to 23.5, and increases gradually to 0.92 at Rs values between 160 and 404. Density norm increases from 1.68 to 2.97 as Rs increases from 5.4 to 23.5, but stays approximately constant until Rs values between 160 and 404. We present equations that express average finite strain as a function of average cylindricity and density norm, which provide a broadly applicable tool for estimating the first‐order finite strain magnitude within any shear zone from which quartz CPO intensity can be measured. To demonstrate their utility, we apply our equations to published data from Himalayan shear zones and a Cordilleran core complex.

Systematic Experimental Evaluation of Aeroelastic Characteristics of a Highly Flexible Wing Demonstrator

This paper presents a comprehensive experimental analysis of the evolutionary modal characteristics of a highly flexible wing that exhibits bending–torsion coupling-driven instability. By implementing operational modal analysis on responses triggered by a combination of an external pulse-like stimulation and turbulence within the flow, this paper presents the airspeed-driven variations of the modal frequencies, damping ratios, and the underlying modal coupling behavior, leading to instability. This analysis is extended to varying the wing root pitch angles through which the effects of geometrical nonlinearity are exercised. Their effects are particularly noted on the hump feature of the airspeed-driven damping ratio locus of the mode responsible for instability. The decreasing critical damping ratio is shown to result in amplified turbulence-driven responses, which pose significant challenges to identification procedures by masking the visibility of other modes. Furthermore, through a novel technique used to analyze the modal coupling, the relative phase and magnitude properties of the coupled bending–torsion composition of the critical mode before and at flutter onset are evidenced experimentally. It is demonstrated that these relative participation measures provide a strong indication of the response content of the limit cycle oscillations that emerge after the flutter speed.

Closely related species differ in their traits, but competition induces high intra-specific variability.

Theories explaining community assembly assume that biotic and abiotic filters sort species into communities based on the values of their traits and are thus based on between-species trait variability (BTV). Nevertheless, these filters act on individuals rather than on species. Consequently, the selection is also influenced by intraspecific trait variability (ITV) and its drivers. These drivers may be abiotic (e.g., water availability) or biotic (e.g., competition). Although closely related species should have similar traits, many of them coexist. We investigated the relative magnitudes of BTV and ITV in coexisting closely related species and how their individual traits differ under different drivers of ITV. We manipulated conditions in a greenhouse pot experiment with four common Carex species, where individuals of each species originated from four source localities. Individuals were grown in factorial combinations of two moisture levels, with and without a competitor (grass species Holcus lanatus, a frequent competitor). We analyzed the variability of six morphological traits on individuals in the greenhouse and three morphological traits in the source localities. Species identity was the main determinant of differences in most traits. Competition exerted a greater effect than water availability. For leaf dry matter content (LDMC) and vegetative height, competition's effect even exceeded the variability among species. On the contrary, for specific leaf area (SLA) and clonal spread, the interspecific differences exceeded ITV induced by experimental treatments. SLA measured in the greenhouse closely correlated with values measured in field populations, while LDMC did not. The variability caused by source locality of ramets in the greenhouse was small, although sometimes significant. Closely related species differ in their traits, but for some traits, ITV can exceed BTV. We can expect that ITV can modify the processes of community assembly, particularly among coexisting closely related species.

Prediction model for self-starting of hypersonic inlets with soft critical unstart mode

The acceleration self-starting performance of hypersonic inlets is of critical importance for the stable operation of scramjet engines. The occurrence of soft unstart during the transition from hard unstart to start is an important flow state that has yet to be fully elucidated. The stability mechanism and corresponding self-starting characteristics of soft unstart remain poorly understood, and there is a pressing need for detailed modeling research in this area. This paper presents a rapid prediction model for the self-starting Mach number of two-dimensional hypersonic inlets with soft critical unstart mode, fully considering the influence of various geometric parameters and Reynolds number in the internal contraction section, and achieving a quantitative analysis of the two-dimensional soft unstart critical flow field. Given the incoming flow conditions and the inlet geometry, the prediction model is capable of accurately representing the actual viscous unstart flow field. It can fully map the unstart separation bubble and its surrounding critical wave structures, and calculate the minimum pressure rise required to maintain the current scale of the main separation bubble and the pressure rise exerted on the unstart separation bubble by the current actual flow field structure. Comparing the relative magnitude of these two pressures determines whether the inlet can transition from soft unstart to start. The proposed prediction model was validated using results from unsteady numerical simulations. The predicted results align well with the simulation results and are significantly better than previous prediction methods.

Revisiting the effectiveness of diamond heat spreaders on multi-finger gate GaN HEMT using chip-to-package-level thermal simulation

The study of chip-level and package-level heat transfer in a GaN high electron mobility transistor (HEMT) is often disconnected due to limited resources and tools. In this work, device simulation from Silvaco Victory Device is carried forward to the chip-to-package-level simulation using Icepak to provide a complete picture of the proposed thermal management strategies using polycrystalline diamond (PCD) heat spreaders. The max junction temperature, Tj = 105.8 °C and the relative magnitude of max temperature on the GaN surface, ΔTj = 18 % are recorded for the original Si-GaN-Si3N4 chip inside TO-220 at 6.0 Wmm−1. Replacing the Si3N4 with PCD (thermal conductivity of 500 Wm−1 K−1) results in Tj = 98.2 °C and ΔTj = 8 %, while replacing the Si results in Tj = 97.0 °C and ΔTj = 11 %. The top layer PCD spreads the heat from hotspot regions to the surrounding epoxy, while the bottom layer PCD improves the heat path from the hotspots to the base plate. Therefore, the reduction in Tj by the bottom layer PCD is more important than the reduction in ΔTj by the top layer PCD. Implementing both the top and bottom layers of PCD results in the best offers of Tj = 92.9 °C and ΔTj = 6 %. The performance of PCD as heat spreaders in multi-finger gate GaN HEMT suggested by these chip-to-package-level simulations are more reliable than device simulation alone since they cover the complete heat path from generation, conduction within the package, and convection to the ambient air.

Using Analytical Hierarchy Process (AHP) for Developing a Performance Evaluation Model for A Human Resources Department in Private Sector in Saudi Arabia

Evaluating human resource departments discovers weak areas and supports performance measurements and continuous quality improvement. However, most research concentrates on the development of models that primarily assess the performance of individual human resources rather than focusing on the evaluation of the entire department. This study aims to formulate a model for evaluating the performance of human resource departments in Saudi Arabia's private sector. The proposed model studies HR standards using five well-known quality awards excellence models. Exploratory Factor Analysis (EFA) was then used to discover the factor structure of this model and examine its internal reliability to identify the underlying relationships between the assessment model criteria (factors). A questionnaire was designed and distributed to middle and high management levels, such as section head positions and above, in different organizations in the private sector in Jeddah. The analytic hierarchy process (AHP) was used to quantify the weights of the assessment factors and subfactors. Human resource experts estimated the relative magnitudes of the factors and sub-factors through pairwise comparisons. The results identified six main factors and seventy-eight subfactors for evaluating human resources department performance in any private sector. The findings indicated that the most substantial weight, constituting nearly 50 of the entire modules, was assigned to Factor 2, denoting "Justice and Human Development" (44.746%). This was followed by Factor 5, related to "Job Performance Management" (18.945%), and Factor 6, about "Occupational Safety" (12.554%). The factor with the lowest weight was Factor 1, representing "Career Guidance and Counseling" (7.601%).

Statistical analysis and forecasting of solar wind parameters across solar cycles

This study investigated the statistical properties of solar wind parameters spanning Solar Cycles 20–24, elucidating periodicities that closely aligned with the solar cycle. Significantly, correlations between the smoothed 27-day average value of solar wind parameters and sunspot numbers (SSN) were discerned, shedding light on the intricate interplay between solar activity and solar wind characteristics. Furthermore, the study employed an optimized Long Short-Term Memory (LSTM+) model for forecasting Solar Cycle 25, demonstrating promising predictive capabilities. The analysis predicted the occurrence time of the peak value of SSN in Solar Cycle 25 to be on 27 October 2024 ± 136 days, based on the average relationship with the occurrence time of the trough of Plasma Beta. Notably, observations revealed a double peak in SC-25’s solar activity, introducing uncertainty regarding the relative magnitude of each peak.

Interpretation of the stress dip test as a means of characterizing backstress: Experiments and backstress-aided crystal plasticity modeling of polycrystalline tantalum

Backstresses, associated with certain dislocation arrangements and their inter-dislocation long-range stresses, are known to contribute significantly to deformation response of metals, including kinematic hardening, the Bauschinger effect (BE) and the Hall-Petch effect. Various methods have been employed to quantify these backstresses at the macro-scale. One of these approaches, which has received relatively little attention, is the stress dip test. The strain rate observed during a load dip and hold, after previous plastic deformation, can be positive or negative, depending upon the level at which the load is held, and the relative magnitudes of competing friction and backstresses. The most direct interpretation of previously reported tests indicates a surprisingly high level of backstress in common materials, and which is generally also higher than the value extracted from an unload-reload test. In this paper, stress dip tests are performed on pure polycrystalline tantalum, along with unload-reload tests. A plateau is seen in the strain rate observed during the stress dip test, which has not been previously reported. If the backstress is interpreted to correspond with the stress level associated with the middle point of the plateau, in line with the friction/backstress model of the unload-reload test, the resulting backstress obtained from both tests are very similar. A novel crystal plasticity model, incorporating backstress, reversible dislocations and non-Schmid effects, is used to help justify this new approach. The model predicts the observed plateau in strain rate, and provides a slip-level interpretation of the macroscopically observed backstress. The slip-level backstress (when considered as a fraction of the stress prior to the dip) is reasonably similar to the values interpreted from the dip test experiment. The ∼23% lower value in the simulation may be due to the lack of certain aspects of the actual physics in the model.

Long-term stability of sediment routing on an active continental margin: Insights from detrital zircon U-Pb ages and measured stratigraphy of Carboniferous to Miocene strata, Sierra de Narváez, NW Argentina

The complex Phanerozoic tectonic evolution of the western margin of South America, including extensional, neutral, and contractional deformation regimes, provides an opportunity to test how sedimentary systems were affected by variable tectonics on a long-lived active margin. Here, we report new geologic mapping, measured stratigraphic sections, paleocurrent measurements, and detrital zircon U-Pb ages from the Fiambalá area, NW Argentina, that together constrain the evolution of sediment routing and basin systems of the northern Sierras Pampeanas during Carboniferous to Miocene time. Carboniferous to Triassic strata of the Paganzo Group include fluvial, lacustrine, and eolian intervals deposited in an extensional setting with SSW-directed paleocurrent orientations. The Mesozoic El Pedernal Formation consists of a lower, basalt interval and an upper, conglomerate and sandstone interval, which has a new detrital zircon maximum depositional age of ca. 88 Ma. Observed strata of the Miocene Tambería Formation include fluvial to eolian sandstones of the lower member of the formation and alluvial conglomerates of the middle member. Whereas lower member Tambería fluvial strata have SSW-oriented paleocurrents, middle member conglomerates indicate broadly E-directed paleoflow.Detrital zircon age distributions of the Paganzo Group, El Pedernal Formation, and Tambería Formation are remarkably consistent, with dominant age peaks ca. 1.3–0.9 Ga and ca. 660-450 Ma. The ages and relative magnitudes of these peaks are consistent with derivation from igneous sources associated with Choiyoi magmatism (330-215 Ma), the Famatinian (490-450 Ma) and Pampean (540-510 Ma) orogens, basement of the MARA block (ca. 1.3–0.9 Ga), and recycling of Neoproterozoic to Cambrian sedimentary successions derived from central Gondwana (ca. 1.3–0.9 Ga, 650-590 Ma, 540-510 Ma).The consistent paleocurrent orientations and detrital zircon U-Pb ages of the Carboniferous Paganzo Group to the Miocene lower member of the Tambería Formation suggest that a S-directed axial drainage network with a consistent sediment source area persisted in the region for ∼300 Myr. This axial drainage network was succeeded by an E-directed transverse drainage network initiated between 15 Ma and 8 Ma due to growth of the Andean thrust wedge, coeval with tectonic compartmentalization and drainage modification of nearby foreland depocenters. These findings highlight the potential for long-term persistence of drainage networks on continental margins under changing tectonic regimes.

Correlated normal state fermiology and topological superconductivity in UTe2

UTe2 is a promising candidate for spin-triplet superconductors, in which a paramagnetic normal state becomes superconducting due to spin fluctuations. Here, we theoretically show that electron correlation induces a dramatic change in the normal state fermiology with an emergent correlated Fermi surface (FS) driven by Kondo resonance at low temperatures. This emergent correlated FS can account for various unconventional superconducting properties in a unified way. In particular, the geometry of the correlated FS can naturally host topological superconductivity in the presence of odd-parity pairings, which become the leading instability due to strong ferromagnetic spin fluctuations. Moreover, two pairs of odd-parity channels appear as nearly degenerate solutions which may lead to time-reversal breaking multicomponent superconductivity. The resulting time-reversal-breaking superconducting state is a Weyl superconductor in which Weyl points migrate along the correlated FS as the relative magnitude of nearly degenerate pairing solutions varies.

Anisotropic Third Harmonic Generation in 2D Tin Sulfide

AbstractThe in‐plane anisotropic properties of 2D group IV monochalcogenides offer an additional degree of freedom which can be advantageous in optoelectronic applications. Here, it is demonstrated that the third harmonic generation (THG) produced by ultrathin tin (II) sulfide (SnS) is in‐plane anisotropic with respect to the direction of the excitation linear polarization. The polarization‐resolved THG (P‐THG) measurements are described with a nonlinear optics model, which accounts for the orthorhombic crystal structure of the 2D SnS. The relative magnitudes of the χ(3) tensor components are calculated by recording and simultaneously fitting two orthogonal polarization components of the P‐THG signals. Furthermore, the “THG anisotropy ratio” is introduced, which compares the THG intensity produced when the excitation linear polarization is along the armchair crystallographic direction, with the case when it is along the zigzag direction. The experimental findings provide quantitative information on the anisotropic nature of the THG process in various SnS flakes. Nonlinear anisotropic 2D materials can be used in future optoelectronic devices, where anisotropic polarization sensitivity is required. Having an optical tool that quantitatively probes the effect of the in‐plane anisotropy among different 2D materials, could be of considerable importance for evaluating the performance of such materials and devices.

Data-driven prediction of future melt pool from built parts during metal additive manufacturing

Smart manufacturing in metal additive manufacturing (MAM) relies on real-time process optimization through the prediction of unbuilt parts using data from built parts. Melt pool dynamics are intimately associated with the development of various microstructures during the MAM. In this paper, we demonstrate the idea by establishing a machine learning (ML) model to predict the melt pool of future parts, based on the experimental data from the National Institute of Standards and Technology (NIST) where 80 % is used for the training (built parts) and 20 % for testing (future parts). The ML model integrates both data denoising and predictive modeling. First, a convolutional neural network (CNN) is used to process a large dataset of raw melt pool images, enabling the automatic removal of noises (e.g., splash and plume) and thereof extraction of high-quality melt pool data. Following that, a novel data-driven melt pool model based on multi-layer perceptron (MLP) is trained by incorporating raw, long scanning history as input features, which best accounts for the effects of printing history (e.g., intertrack heating) on melt pool development. It takes complete advantage of MLP in handling high-dimensional regression problems in conjunction with a large dataset. Upon testing under various manufacturing conditions, the average relative error magnitude (AREM) of predicting melt pool size drops to 2.8 %, compared to 14.8 % of the prior art – the Neighboring Effect Modeling Method model (NBEM). This research thus represents a significant step towards reliable melt-pool-guided AM process optimization for smart manufacturing, enabled by advanced, flexible, and maximum use of ML techniques.

Simulated Slidequakes: Insights From DEM Simulations Into the High‐Frequency Seismic Signal Generated by Geophysical Granular Flows

AbstractGeophysical granular flows generate seismic signals known as “slidequakes” or “landquakes”, with low‐frequency components whose generation by mean forces is widely used to infer hazard‐relevant flow properties. Many more such properties could be inferred by understanding the fluctuating forces that generate slidequakes' higher frequency components and, to do so, we conducted discrete‐element simulations that examined the fluctuating forces exerted by steady, downslope‐periodic granular flows on fixed, rough bases. Unlike our previous laboratory experiments, our simulations precluded basal slip. We show that, in its absence, simulated basal forces' power spectra have high‐frequency components more accurately predicted using mean shear rates than using depth‐averaged flow velocities, and can have intermediate‐frequency components which we relate to chains of prolonged interparticle contacts. We develop a “minimal model”, which uses a flow's collisional properties to even more accurately predict the high‐frequency components, and empirically parametrize this model in terms of mean flow properties, for practical application. Finally, we demonstrate that the bulk inertial number determines not only the magnitude ratio of rapidly fluctuating and mean forces on a unit basal area, consistent with previous experimental results, but also the relative magnitudes of the high and intermediate‐frequency force components.

Forest cover lessens hurricane impacts on peak streamflow

AbstractCyclonic storms (i.e., hurricanes) are powerful disturbance events that often cause widespread forest damage. Storm‐related canopy damage reduces rainfall interception and evapotranspiration, but impacts on streamflow regimes are poorly understood. We quantify streamflow changes in Puerto Rico following Hurricane Maria in September 2017, and evaluate whether forest cover and storm‐related canopy damage account for the differences. Streams are particularly vulnerable to flooding in early post‐disturbance stages during hurricane season, so we focus on 3 months (Oct–Dec) following the hurricane. To discern changes in rainfall responses, we partitioned streamflow into baseflow and quickflow using a digital filter. We collected 2010–2017 streamflow and rainfall data from 18 watersheds and compared the relative magnitude of post‐ to pre‐hurricane double mass curve slopes of baseflow and quickflow volumes against rainfall. Several watersheds displayed higher post‐hurricane quickflow and baseflow, however, the response was variable. The magnitude of quickflow increase was greater in watersheds with high forest damage. Under the same level of relative damage, watersheds with low initial forest cover had greater quickflow increases than highly forested ones. Conversely, baseflow generally increased, but increases were greater in highly forested watersheds and smaller in highly damaged watersheds. These results suggest that post‐storm baseflow increases were due to recharge of hurricane‐related rainfall, as well as forest transpiration interruption and soil disturbance enhancing recharge of post‐hurricane rainfall, while increases to quickflow are related to loss of canopy rainfall interception and higher soil saturation decreasing infiltration. Our research demonstrates that forest damage from disturbance lowers quickflow and elevates baseflow in highly forested watersheds, and elevates quickflow and lowers baseflow in less‐forested watersheds. Less‐forested watersheds may be closer to the forest cover loss threshold needed to elicit a streamflow response following disturbance, suggesting higher flooding potential downstream, and a lower storm‐related forest disturbance threshold than in heavily forested watersheds.

Mean-flow structures of the turbulent boundary layers bounding a two-dimensional separation bubble

Understanding the mean-flow structures of a separated turbulent boundary layer (TBL) is crucial for turbulence modeling. This study investigates the spatial scaling properties of the total shear stress and mixing length in the TBLs bounding a two-dimensional (2D) separation bubble, aiming to derive analytical descriptions for the entire mean-velocity profiles of the TBLs. For the adverse pressure gradient (APG) TBL upstream of the separation bubble, the total shear stress possesses a two-layer structure with an inner layer adhering to a linear law and an outer layer conforming to a defect power law. In contrast, the mixing length profile consists of four layers, namely the viscous sublayer, the buffer layer, the overlap layer, and the wake region. Each of the layers exhibits a power law or a defect power law relationship with the spatial coordinate normal to the wall. In the four-layer structure, three parameters are sensitive to the variation of the APG: the buffer-layer thickness, the relative magnitude of the mixing length at the boundary layer edge, and a defect power law exponent quantifying the extent of the wake region. For the reattached TBL downstream of the separation bubble, the total shear stress consists of two parts. One part is induced by the pressure gradient and retains the two-layer structure, while the other, engendered by the intense turbulence advected from the separated shear layer, exhibits a dual-power-law distribution. The advected turbulence also significantly alters the four-layer structure of the mixing length, resulting in an augmented buffer layer, a diminished overlap layer, and a wake region that mimics a turbulent mixing layer. Via a dilation ansatz to describe the scaling transition between adjacent layers, the study formulates the complete profiles of the total shear stress and mixing length. The formulation leads to the derivation of novel analytical expressions for the entire mean-velocity profiles of the TBLs. The expressions are in precise accord with the direct numerical simulations of an incompressible 2D separation-bubble flow and a 2D impinging shock wave/TBL interaction. The elucidation of the mean-flow structures through this study is anticipated to facilitate the analysis of turbulence models, thereby enhancing their performance in simulating separated TBLs. The construction of the mean-flow descriptions by inspecting the spatial scaling properties of turbulence paves a promising way for theoretical exploration of complex nonequilibrium TBLs.

Effect of anion α-functionalization on the water affinity of thermo-responsive phosphonium acetate-derived ionic liquids

This study presents a facile method for assessing the effect of anion functional group substitution on the water affinity of phosphonium-acetate ionic liquids. By combining the same cation with three different α-substituted carboxylate anions, the effect of anion functional group substitution on the IL miscibility with water and hygroscopicity was experimentally evaluated and rationalized using COSMO-RS sigma profile analysis. Lower critical solution temperature (LCST) phase separation experiments and water vapor partial pressure measurements revealed that there is a stark α-substitution dependency on the affinity of water for acetate [AcO], pivalate [PivO], and trifluoroacetate [TFA] derived tributyl(octyl)phosphonium [P4448] ILs. It was found that the IL water affinities varied as: [P4448][AcO] > [P4448][PivO] > [P4448][TFA]. With the lowest water partial pressure and no LCST driven phase separation, [P4448][AcO] exhibited a high affinity for water. On the other hand, [P4448][PivO] and [P4448][TFA] exhibited LCST-driven phase separation and room temperature immiscibility, respectively, with higher water partial pressures, as a result of relatively weak water affinities. COSMO-RS sigma profile analysis revealed that the aliphatic carboxylate anions should incorporate apolar interactions commensurate with or greater than the polar hydrogen bond acceptor interactions for phase immiscibility of the corresponding IL with water. It was found that the relative magnitudes of apolar and polar interactions, assessed using the anion sigma profile peak intensity ratio (Ir), are directly correlated with the IL water affinity, and inversely correlated with the solution water activity coefficient. Therefore, it was concluded that Ir forms a quantitative link between the structural changes at the molecular level and the bulk water affinity exhibited by the ionic liquid as a whole.

Oblique spin injection to graphene via geometry controlled magnetic nanowires

We exploit the geometry of magnetic nanowires, which define 1D contacts to an encapsulated graphene channel, to introduce an out-of-plane component in the polarisation of spin carriers. By design, the magnetic nanowires traverse the angled sides of the 2D material heterostructure. Consequently, the easy axis of the nanowires is inclined, and so the local magnetisation is oblique at the injection point. As a result, when performing non-local spin valve measurements we simultaneously observe both switching and spin precession phenomena, implying the spin population possesses both in-plane and out-of-plane polarisation components. By comparing the relative magnitudes of these components, we quantify the angle of the total spin polarisation vector. The extracted angle is consistent with the angle of the nanowire at the graphene interface, evidencing that the effect is a consequence of the device geometry. This simple method of spin-based vector magnetometry provides an alternative technique to define the spin polarisation in 2D spintronic devices.