Shortwave Research Articles

Micronized versus super-conditioned corn: Effects on starch digestion, performance, and blood metabolites of Holstein dairy calves.

Micronization, a dry-heat process, generates infrared electromagnetic short waves that can affect starch granules and gelatinization. A new method of corn processing, super-conditioned corn, a moisture-heat process, has potential to increase starch digestion and performance in calves. Therefore, incorporating super-conditioned or micronized corn in starter feed may enhance growth performance by improving total-tract starch digestion. This study aimed to evaluate the impacts of heat (micronizing and super-conditioning) and conventional processing method (grinding) of corn grain on the starch digestion, skeletal growth, feeding behavior, biochemical status of blood, and performance of dairy calves. Thirty-six Holstein female dairy calves [40 ± 1.8 kg of body weight (BW)] were assigned to 3 groups that starter feed contained 58% of one of the following corn types: the control group with dry ground corn (n = 12, GC), a group receiving micronized corn (n = 12, MC), or a group receiving super-conditioned corn (n = 12, CC). Three mash starter feeds with an identical nutritional composition were blended with 5% chopped alfalfa hay and fed to individually housed calves from wk 1 to 11 of their birth. All calves were fed 4 L/d of pasteurized whole milk twice daily since d 3 to wk 8, followed by 2 L/d of morning feeding from wk 10 to 11 of age. Calves were weaned on wk 9 and remained in the study until wk 11. Intake of feed was reported weekly and body measurements were recorded on d 3, wk 9, and 11 of age. Blood samples were collected from jugular vein on the last day of wk 11 of age. Behavioral data were recorded by direct observations of all the calves equal to 12 h before (d 61 to 63 of age) and 12 h after (d 75 to 77 of age) weaning. Final BW, average daily gain (ADG) and feed efficiency (FE) increased in calves fed CC compared with GC and MC in the overall period. An interaction of treatment × week was detected for total DMI on wk 10 and 11 of age where it was lower in the CC than in the GC and MC counterparts. However, feeding starter feed containing CC increased total-tract DM and starch digestibility compared with MC and GC. Rumination time and eating time decreased in CC calves than MC and GC calves. Moreover, significant treatment × week interactions were observed for the skeletal growth. On wk 11 of age, compared with the GC and MC, wither height and hip height was greater in calves fed CC. The CC formulation increased the concentrations of insulin and glucose fraction in blood while these parameters were not different between GC and MC. In conclusion, CC improved the ADG, FE, and skeletal growth, while reduced total DM intake during post-weaning period compared with MC and GC. Based on the positive changes in ADG, FE, and skeletal growth; CC was superior to the MC and GC, due to improved starch digestion.

Experimental investigation on seakeeping performance of variable-structure SWATH in heading regular waves

The variable-structure unmanned surface vehicle (VS-USV) have high maneuverability, strong survival, and multitasking characteristics in complex sea environment. In this study, a variable-structure small waterplane area twin hull (VS-SWATH) is proposed, which combines the advantages of straight strut SWATH and inclined strut SWATH. In order to study the seakeeping performance of the VS-SWATH with rotatable strut and hydrofoils at medium to low speeds, a series of seakeeping towing model tests was conducted. A variable-structure device was installed on the test model to change the strut rotation angle, and a detachable hydrofoil adjustment device was designed for the test model enabling the exchange of wingless and winged models. The test equipment includes a seaworthiness instrument system and a data acquisition system to measure values such as pitch, heave, vertical acceleration, and monitor the fluid around the ship. The test results show that the VS-SWATH can avoid resonance by changing the strut rotation angle. Hydrofoils mainly reduce heave and pitch at longer wavelengths, but their improvement in seakeeping performance is relatively limited in short waves.

Analysis of the Influence of Clear-Sky Fluxes on the Cloud-Type Mean Cloud Radiative Effects in the Tropical Convectively Active Regions With CERES Satellite Data.

Cloud radiative effects (CREs) and cloud-type mean CREs depend upon how clear-sky fluxes are computed over a large area: those of the immediate environment of clouds or the regional mean clear-sky fluxes. Five convectively active regions in the Tropics, two over land (Africa and Amazon) and three over ocean (eastern and western Pacific and Atlantic), are selected to understand the influence of immediate environment of clouds on CREs. Fluxes derived from 19years of high-resolution CERES satellite data, categorized by cloud type, are utilized. The cloud types are classified based on the joint cloud top pressure and cloud optical depth distribution. For the entire tropical region, differences in cloud-type mean CRE with regional mean and immediate environment clear skies range from -7.8 to 10.7Wm-2 for shortwave (SW), 2.9 to 15.8Wm-2 for longwave (LW), and 6.1 to 17.9Wm-2 for net, respectively. The oceanic and Amazonia regions have negative (positive) SW (LW) CRE differences, typically 2-6Wm-2 in SW but 7-10Wm-2 in LW, whereas Africa has positive SW and LW CRE differences (typically 20-30Wm-2, up to 40-50Wm-2). The influence of immediate environment reduces the regionally averaged, that is, cloud-type mean CREs weighted by cloud fractions, SW cloud cooling, and LW cloud warming in four of the five regions except for Africa. For Africa, it increases the SW cloud cooling and greatly reduces the LW cloud warming, resulting in net cloud cooling as in other regions instead of warming. The implications of these findings for observational and modeling studies are discussed.

Comparative analysis of high-temperature targets retrieved from SWIR and TIR data

IntroductionForest fires, grassland fires, heap coking, straw burning, and volcanic eruptions are thermal anomalies. They attract attention and are designated as high-temperature targets. They can be retrieved macroscopically and quickly by remote sensing technology.MethodsIn temperature inversion, the mid-infrared (MIR, 3∼5 μm) and thermal infrared (TIR, 8∼14 μm) band data are most commonly used for temperature inversion. However, it is difficult to effectively retrieve the temperature of small-area high-temperature targets with them; the SWIR band data can perform this task more effectively. Additionally, inversion methods for short-wave infrared (SWIR, 1.3∼2.5 μm) and TIR band data are different. These differences lie in the mechanisms and models. Therefore, we use SWIR and TIR band data to retrieve heap coking temperature with Landsat 7 and Landsat 8 data.ResultsSWIR data obtained the results 496∼651 K and 912 K, and TIR data obtained the results 313∼334 K and 320 K.ConclusionThe SWIR inversion results have higher accuracy than the TIR inversion results. The inversion results are closer to the actual temperature of local coking. For this reason, SWIR is more suitable for temperature inversion of small-area high-temperature targets.

Linear instability in thermally stratified quasi-Keplerian flows

Quasi-Keplerian flow, a special regime of Taylor–Couette co-rotating flow, is of great astrophysical interest for studying angular momentum transport in accretion disks. The well-known magnetorotational instability (MRI) successfully explains the flow instability and generation of turbulence in certain accretion disks, but fails to account for these phenomena in protoplanetary disks where magnetic effects are negligible. Given the intrinsic decrease of the temperature in these disks, we examine the effect of radial thermal stratification on three-dimensional global disturbances in linearised quasi-Keplerian flows under radial gravitational acceleration mimicking stellar gravity. Our results show a thermo-hydrodynamic linear instability for both axisymmetric and non-axisymmetric modes across a broad parameter space of the thermally stratified quasi-Keplerian flow. Generally, a decreasing Richardson or Prandtl number stabilises the flow, while a reduced radius ratio destabilises it. This work also provides a quantitative characterisation of the instability. At low Prandtl numbers $Pr$ , we observe a scaling relation of the linear critical Taylor number $Ta_c\propto Pr^{-6/5}$ . Extrapolating the observed scaling to high $Ta$ and low $Pr$ may suggest the relevance of the instability to accretion disks. Moreover, even slight thermal stratification, characterised by a low Richardson number, can trigger the flow instability with a small axial wavelength. These findings are qualitatively consistent with the results from a traditional local stability analysis based on short wave approximations. Our study refines the thermally induced linearly unstable transition route in protoplanetary disks to explain angular momentum transport in dead zones where MRI is ineffective.

Optimal Configuration of Physical Process Parameterization Scheme Combination for Simulating Meteorological Variables in Weather Research and Forecasting Model: Based on Orthogonal Experimental Design and Comprehensive Evaluation Method

The weather research and forecasting (WRF) model is frequently used to investigate the meteorological field around nuclear installations. The configuration of physical process parameterization schemes in the WRF model has a significant impact on the accuracy of the simulation results. Consequently, carrying out a pre-experiment to quickly obtain the optimal combination of parameterization schemes is essential before conducting meteorological parameter research. To obtain the optimal combination of physical process parameterization schemes from the planetary boundary layer (PBL), land surface (LSF), microphysical (MP), long-wave (LW), and short-wave (SW) radiation processes of the WRF model for simulating the near-surface meteorological variables near a nuclear power plant in Sanshan Town, Fuqing City, Fujian Province, China on 4 June 2019 were observed. Orthogonal experimental design (OED), a comprehensive evaluation method based on the CRiteria Import Through Intercriteria Correlation (CRITIC) weight analysis, and comprehensive balance method were employed for the first time to conduct the research. The sensitivity of meteorological variables to physical processes was first discussed. The findings revealed that the PBL scheme configuration had a profound impact on simulating wind fields. Furthermore, the LSF scheme configuration had a significant influence on simulating near-surface temperature and relative humidity, which was much greater than that of other physical processes. In addition, the choice of the radiation scheme had a significant impact on how the temperature was distributed close to the ground and how the wind field was simulated. Furthermore, the configuration of the MP scheme was found to exert a certain influence on the simulation of relative humidity; however, it demonstrated a weak influence on other meteorological variables. Secondly, The MYNN3 scheme for PBL process, the NoahMP scheme for LSF process, the WSM5 scheme for MP process, the RRTMG scheme for LW process, and the Dudhia scheme for SW process are found to be the comprehensive optimal physical process parameterization scheme combination for simulating meteorological variables in the research area selected in this study. As evident from the findings, the use of the OED method to obtain the combinations of the optimal physical process parameterization scheme could successfully reproduce the wind field, temperature, and relative humidity in the current study. Thus, this method appears to be highly reliable and effective for use in the WRF models to explore the optimal combinations of the physical process parameterization scheme, which could provide theoretical support to quickly analyzing accurate meteorological field data for longer periods and contribute to deeply investigating the migration and diffusion behavior of airborne pollutants in the atmosphere.

Investigating the “Too Bright” Issue Pertaining to Non‐PBL Clouds Over the South Pacific Trade‐Wind Region in CMIP6 Global Climate Models

AbstractThis paper examines the “too bright” issue pertaining to non‐planetary boundary layer (PBL) clouds over the South Pacific trade‐wind region and its potential link to the falling ice radiative effects (FIREs). We run sensitivity experiments with CESM2‐CAM6 (CESM2) global climate model with FIREs on (SON) and off (NOS). The model exhibits more in‐cloud liquid water content (CLWC) and droplet above the PBL in NOS, leading to larger shortwave (SW) reflectivity at the top of the atmosphere than in SON over the trade wind regions. CMIP6 models are divided into three subsets: separately calculates the radiative effects of cloud ice and falling ice (SON2), combined (SON1) and without falling ice (NOS). SON2 models exhibit improved CLWC and SW reflectivity similar to CESM2‐SON, while NOS and SON1 models are akin to CESM2‐NOS owing to weaker surface wind stress and warmer ocean surface, caused by the lack of FIREs over the convective zones.

Angle insensitive filters based on Fabry–Pérot resonance structures

Filters based on plasmon resonance suffer from low efficiency due to inevitable metal loss. Moreover, their operational limitations, particularly their inability to function effectively at large incident angles, significantly restrict their practical applications. To address these challenges, we propose an all-dielectric filter characterized by relatively small Ohmic loss and remarkably high efficiency, even at wide incident angles. The filter is based on Fabry–Pérot cavity resonance, with narrow bandwidth and high transmittance. The transmittance in the near-infrared band is as high as 99%, and the transmittance in the shortwave band is highly suppressed. This filter offers ease of manufacture coupled with exceptional efficiency. It is expected to gain application prospects in different fields such as liquid crystal displays, optical communications, sensor detection, and imaging.

Alteration and mineralization features of the Akcal Epithermal Gold Deposit, Biga Peninsula, Western Anatolia, Turkey: Evidence for low-sulfidation Au-Ag-Sb mineralization

The Akcal epithermal Au-Ag deposit, located on the Biga Peninsula, southwestern Turkey is estimated to contain 32.5 million tonnes of mineralization at an average grade of 1.03 g/t Au, equivalent to 1.2 million ounces of gold. Epigenetic mineralization is hosted by the lower Miocene Sapci volcanic suite, a calc-alkaline subduction-related volcanic arc consisting mainly of andesitic and basaltic andesitic rocks, while the coeval Soma Formation is composed of sandstone, claystone, conglomerate, marl-limestone, siltstone, and tuffite. Near the base of the volcanic pile, the Karakaya Complex is represented by limestone blocks of various sizes (from a few millimetres to several kilometres) within the Sapci volcanic suite. Short wave infrared (SWIR) and X-ray diffraction (XRD) analyses have shown that kaolinite, illite-smectite, montmorillonite, illite, beidellite, gypsum, vermiculite, quartz, and chlorite are the most common alteration minerals at Akcal. The alteration mineralogy indicates that the temperature of hydrothermal fluids broadly varied from 150° to 230°C, with a mildly acidic pH range of 5.0 to 6.5; these conditions accompanied by a lack of alunite suggest low-sulfidation epithermal conditions for the formation of the Akcal epithermal Au-Ag deposit. Petrographic examination and microanalysis by scanning electron microscopy indicate that mineralization at Akcal consists of pyrite and arsenopyrite with lesser hematite, ilmenite, rutile, and apatite. The occurrence of pyrite and hematite on cleavage planes of hydrothermal biotite is evidence of replacement of an earlier potassic alteration phase. Further petrographic examination of the basal limestone reveals replacement by sulfides displaying complex colloform intergrowths of pyrite and marcasite. The lack of skarn alteration and marble supports a carbonate-replacement origin for sulfides occurring in the basal limestone and is likely related to epithermal mineralization at Akcal. Geochemical results show that an Au-Ag-As-Sb±Pb±Zn signature is dominant across the volcanic-hosted epithermal mineralization and carbonate-replacement occurrences in the basal limestone; the lack of Cu mineralization (< 92 ppm) is typical of low-sulfidation epithermal systems. Strong positive correlations between Au and Ag (r′=0.77), As (0.80), and Sb (0.86) indicate that gold is likely hosted as a sub-microscopic phase within pyrite, arsenian pyrite, and arsenopyrite; visible gold (or free gold) and (or) electrum were not identified at Akcal. A model of fluid mixing involving shallow circulating meteoric waters with deeper magmatic-hydrothermal fluids is proposed for the genesis of gold mineralization at Akcal; a positive Au correlation with Mo (r′=0.74) and Mo concentrations of up to 582 ppm, support the involvement of magmatic-hydrothermal fluids in the epithermal system. Boiling as a mechanism for gold precipitation is unlikely given paleodepths of greater than 250 meters (3.0-5.0 MPa) and model temperatures of 150° to 230 °C. Mineralogical and textural evidence of boiling, such as adularia, bladed calcite, and lattice-texture quartz, have not been observed at Akcal. However, the presence of a silica-rich blanket with chalcedony (at Akcal surface) and having formed near the paleo water table may indicate some involvement of CO 2 – rich steam-heated waters, which could suggest some influence from boiling at depth, although evidence of boiling has not been confirmed in samples from Akcal. Precipitation of gold during the fluid mixing process would have occurred through a shift to higher f O 2 conditions and destabilization Au-thiosulphide complexes. This shift towards higher f O 2 is supported by the occurrence of gypsum and hematite with gold mineralization at depth.

Approximation of the Absorption Spectrum of Indium Phosphide in the Context of Simulation of the Process of Sensitivity Enhancement

Examines the fundamental rights of Phosphide of India, legitimized by Tellur and, in the last resort, compensated for. Data on the composition of four high-quality images of the InP: Cu photoelectronic spectrum are presented in the individual layers. The work is characterized by the semi-empiric approach to photoconduction of InP: Cu oxide films. It is concluded that the photoresistance Iph (α(ћω)) was analytically approximated as the function of the experimental-complete spectral distribution of the coefficiency phosphorus india. It is proposed to use five approximating functions with the aim of analyzing the coefficient of absorption of Indian phosphorus α(ћω). Completed 5 locations with different signs of median isolation. On the basis of analytical amplitudes, the complete analytical amplitude Iph(α(ћω)) is modelled. Analogously, five conclusions were drawn that indicate a sign of median isolation. Five non-stationary measures of IF photometry have been taken (as two functions: co-efficiency of exposure, as photo energy functions, and time-consuming observations) in normal situations. The answer to the question is the most mathematical and physical solution of the proximate function α(ћω). Obviously, it shows that this the degree of variance is optimal for its implementation (inclusion of this degree of variance in the structure Iph = f(α) and α = f(ћω)) of the complete analytical description of the process photoconductivity. It should be noted that subsequent research may be based on the establishment of physical bases of photoconductivity in the short wave of fundamental transfers of phosphorus from India, as well as research into the properties of air on the high InP: Cu layer, with its stability and stability.

Phyotochemical Analysis of Bridelia scandens Willd a folk lore herbal drug a Review

Analytical study deals with the modern pharmaceutical analysis of the leaves of the drug. Here, organoleptic characters, physico-chemical parameters, UV spectrophotometric study, chromatographic study which were carried out for the standardization of both leaf powder and leaf oil samples are documented. The leaf powder sample of the plant yielded moisture, 10.1`%, ash, 6.65%, water soluble extractive 16.5% and methanol soluble extractive 22.3%. Whereas the leaf oil sample showed specific gravity 0.9650; refractive index 1.473; acid value 1.17; saponification value 241.4; ester value 240.23 and unsaponifiable matter 0.55%. UV spectrophotometric study of the leaf powder sample showed three absorptions peaks: the absorption being maximum at 218 nm followed by 272 nm and 666 nm. The spectra of the unsaponifiable matter of the leaf oil sample also showed three absorption peaks at 209 nm, 235 nm and 287 nm. Comparison of these two spectra reveals that their pattern is different. The chromatogram of both the samples obtained in day light showed 8 spots in the leaf powder sample and no spots in the other sample. On viewing under short wave UV radiation, the leaf powder sample revealed 3 spots and the other sample 2 spots. Among the spots the spot at Rf 0.66 was present in both the samples. After exposing to Iodine vapour almost all the spots viewed in day light were revealed in the first sample and 5 spots were found in the second sample. On spraying with vanillin sulphuric acid 6 spots were revealed in leaf powder sample and 5 spots in second sample. Among these 2 spots at Rf 0.46 and 0.66 were common in both the samples.

Undular Bore Due to a Low Pressure or Bottom Trough Moving at the Critical Speed

AbstractA low pressure or bottom obstacle of negative displacement moves at the critical speed along a fluid layer of constant depth. The disturbance causes a depression of the surface at its forward position. The nonlinear dynamics generates a group of short waves attached to the disturbance. The number of two to six crests have a wavelength of 5.7–12 times the water depth. The wave height increases with the decreasing wavelength. The waves of the group do not follow the dispersion properties of cnoidal waves or Stokes waves. The group is rather characterised as an undular bore. The bore develops during a travel distance of 7–15 times the length of the disturbance. Its front eventually moves ahead of the driving disturbance where the leading crest develops into a solitary wave. A short disturbance is more powerful, but generates fewer crests compared to a long one. Comparison to the generation phase of upstream waves due to a high pressure (ship) or a bottom elevation shows that the wavelength in the two cases is approximately equal.

Experimental investigation on cross-shore profile evolution of reef-fronted beach

Physical experiments on cross-shore profile evolution of the reef-fronted beach are conducted considering various offshore wave conditions and reef settings. Cross-shore beach profile evolution, sediment transport rate, and waves at the beach toe are analyzed. The reef-fronted beach is found to be resilient to erosion induced by offshore sediment transport. In present cases, the beach evolves from a sloping profile to a reflective profile, and onshore sediment transport leads to the formation of a swash berm. Both the shortwaves and infragravity waves at the beach toe play an important role in forming the beach shape. The berm foreshore slope mainly depends on the wave energy density in the infragravity band at the beach toe. Wave energy density in the shortwave band at the beach toe increases with reef submergences, while wave energy density in the infragravity band at the beach toe increases with offshore wave heights. The temporal evolution of sediment transport rate exhibits two modes, implying complex feedbacks occur between swash flows and beach profile evolution. The bulk transport on the reef-fronted beach is parameterized by the relative height of shortwaves and wave steepness of both shortwaves and infragravity waves at the beach toe. A conceptual model of bulk transport on the beach is proposed that the bulk transport increases with the Gourlay number, indicating that reef-fronted beaches with a well-developed reef flat are resilient to increasing wave exposure.

Interactions between swell and colinear wind short crested waves, following and opposing

When wind blows over a water surface during a swell, it generates short-crested, three-dimensional waves that interact with the underlying flow field through a mechanism that ultimately increases the average energy. In the present work, two test cases in which wind is flowing following and opposing a swell are analysed with experiments and are compared with wind–waves-only and swell-only cases. The analysis of the free surface fluctuation and of the flow field, with the three components of fluid velocity measured at the same time through a stereo particle image velocimetry system, leads to an accurate quantification of the energy distribution, of the structure of the oscillating, fluctuating (due to wind–waves) and turbulent kinetic energy, without assumptions on the structure of the flow. The findings demonstrate that the transverse dynamics is a pivotal factor in the transfer of energy in the near-free surface domain, and elucidate the energy transfer between wind–waves and swell. The results also confirm the reduction of oscillating kinetic energy of the swell in the presence of short wind–waves, a process interpreted with different possible mechanisms. There is evidence of the enhancement of wind action in the presence of swell compared to that in the case of wind–waves-only, confirming that energy transfer from the wind to the sea is enhanced when wind flows over a swell. Consequently, when the fetch is influenced by swells generated or propagated from different regions, and during multi-peak sea storms, wave generation models should account for this amplification.

Supercontinuum saturation of a femtosecond laser filament in pressurized gases.

Filamentation of high-power femtosecond optical pulses in high-pressure gases has gained increasing academic and practical interest from the viewpoint of studying large-scale spectral and temporal transformations occurring with pulsed laser radiation and obtaining super-broadened spectra and extremely short (attosecond) wave packets. Experimentally and theoretically, for the first time to the best of our knowledge, we show that as a result of a 45 fs Ti:sapphire laser pulse filamentation in an optical cell filled with pressurized up to 50 bar nitrogen or argon, the pulse spectrum can reach maximally about eightfold broadening. This limiting pulse spectral width is reached at a gas pressure of about 20 bar and with further pressure increase exhibits saturation and even a slight decrease relative to the limiting value. As a possible reason for this finding, we suppose the increase of pulse energy depletion in the self-created plasma at high gas pressure.

The suppression of ocean waves by biogenic slicks.

Ocean waves are significantly damped by biogenic surfactants, which accumulate at the sea surface in every ocean basin. The growth, development, and breaking of short wind-driven surface waves are key mediators of the air-sea exchange of momentum, heat and trace gases. The mechanisms through which surfactants suppress waves have been studied in great detail through careful laboratory experimentation in quasi-one-dimensional wave tanks. However, the spatial scales over which this damping occurs in structurally complex surfactant slicks on the real ocean have not been resolved. Here, we present the results of field observations of the spatial response of decimetre- to millimetre-scale waves to biogenic surfactant slicks. We found that wave damping in organic material-rich coastal waters resulted in a net (spatio-temporally averaged) reduction of approximately 50% in wave slope variance relative to the open ocean for low to moderate wind speeds. This reduction of wave slope variance is understood to result in a corresponding reduction in momentum input to the wave field. This significant effect had thus far evaded quantification due in large part to the enormous range of scales required for its description-spanning the sea surface microlayer to the ocean submesoscale.

Invariant solutions, lie symmetry analysis, bifurcations and nonlinear dynamics of the Kraenkel-Manna-Merle system with and without damping effect

This work investigates the Kraenkel-Manna-Merle (KMM) system, which models the nonlinear propagation of short waves in saturated ferromagnetic materials subjected to an external magnetic field, despite the absence of electrical conductivity. The study aims to explore and derive new solitary wave solutions for this system using two distinct methodological approaches. In the first approach, the KMM system is transformed into a system of nonlinear ordinary differential equations (ODEs) via Lie group transformation. The resulting ODEs are then solved analytically using a similarity invariant approach, leading to the discovery of various types of solitary wave solutions, including bright, dark, and exponential solitons. The second approach involves applying wave and Galilean transformations to reduce the KMM system to a system of two ODEs, both with and without damping effects. This reduced system is further analyzed to investigate its bifurcation behavior, sensitivity to initial conditions, and chaotic dynamics. The analysis reveals the presence of strange multi-scroll chaotic dynamics in the presence of damping and off-boosting dynamics without damping. In addition to these approaches, the study also applies the planar dynamical theory to obtain further new soliton solutions of the KMM system. These solitons include bright, kink, dark, and periodic solutions, each of which has been visualized through 3D and 2D graphs. The results of this research provide new insights into the dynamics of the KMM system, with potential applications in magnetic data storage, magnonic devices, material science, and spintronics.

The evolution of the coronal loop structure due to the phase mixing of high and low-frequency Alfvén waves

ABSTRACT Coronal loops are known to host Alfvén waves propagating in the corona from the lower layers of the solar atmosphere and because of their internal structure, phase mixing is likely to occur. The structure of the coronal loop could be significantly affected by the thermodynamic feedback of the heating generated by phase mixing. However, this phenomenon can be sensitive to the period of the propagating Alfvén waves due to how short period waves can be easily dissipated and the way long-period waves may accumulate considerable energy in resonating coronal loops. Using the Lare2d code, a coronal loop model of a field-aligned thermodynamic equilibrium and a cross-field background heating profile is created, with an additional forcing term added to drive Alfvén waves with coronal amplitudes between $5{\!-\!}30 \, \mathrm{km} \, \mathrm{s}^{-1}$. We show that high-frequency waves can generate heating corresponding to a ${\sim} 10~{{\ \rm per\ cent}}$ increase of the initial coronal shell temperature, chromospheric upflows of up to $0.6 \, \mathrm{km} \, \mathrm{s}^{-1}$ and a coronal shell mass increase of ${\sim} 15~{{\ \rm per\ cent}}$. These changes are sufficient to alter and maintain a new coronal loop density structure, broadening the region where efficient phase mixing (and therefore heating) occurs. In contrast, low-frequency waves are unable to be effectively dissipated, resulting in minimal changes to the loop structure. We see little evidence of wave energy accumulation in the corona and are unable to conclude that the dissipation of low-frequency Alfvén waves can be an effective heating mechanism in coronal loops in the setup used in this study.

Nonlinear analysis of hydrodynamics of a shallow-draft floating wind turbine

AbstractThis study investigates numerically the dynamic responses of the T-Omega Wind novel concept of Floating Offshore Wind Turbine. The turbine is light-weight, has a shallow-draft and a relatively high centre of gravity that allows it to glide over harsh marine environments. The turbine responses are studied under regular wave excitation, considering most probable ranges of discrete sea wave heights and periods representative of real ocean conditions. A multibody virtual model is developed, simplified to a rigid 6 DOF system and experimentally validated in the state-of-art Marine Simulator to define the types of dynamical responses for both “Low” and “High” Sea States. The dynamics of coupled heave and pitch DOFs are evaluated with time histories, phase-plane portraits, Poincaré sections and FFT analyses to conclude that period-1 stable solutions exist for all studied cases of “Low Sea States”, whereas period-2, period-3 and period-4 periodic responses are identified for short wave periods of excitation under “High Sea States” conditions. Simulation results show that regions where period-1 responses exist are highly sensitive to wave height and can widen as the wave amplitude reduces. Finally, the turbines’ nonlinearities generated by the floats’ geometry are observed in this dynamical system, which are identified to be related to variation in float waterplane area and particularly observable for “High Sea States”.

Energy budget trends over the Korean peninsula in the past 20 years

The term “Energy Budget” represents the incoming solar energy, outgoing amounts of energy, and the energy retained in the Earth’s atmosphere. This article aims to analyze the energy budget trend in the Korean Peninsula over the period from 2001 to 2022, focusing on the Earth’s Energy Imbalance (EEI) and the role of cloud cover and how it influences shortwave (SW) and longwave (LW) radiation. Using the dataset obtained from NASA’s CERES satellite, the article investigates the amount of reflected and emitted energy globally and compares it with the Korean peninsula. The findings indicate that globally, the total wave which is the sum of all longwave, shortwave, and cloud shortwave radiation has increased in trend. The plot also displays a decrease in Cloud fraction (CL fraction) or cloud coverage. Contrary to this, the Korean peninsula displayed a relatively stable level of total radiation and an increase in CL fraction. However, further analysis is needed to understand the factors behind these regional differences, including the potential influence of monsoon circulation patterns.