esa-sceva/satcom-chunk-collection huggingface dataset:
## 1 Introduction
Considering the importance of the location, a modern multi-constellation and multi-frequency GISTM receiver (Septentrio-PolaRx5S) has been established recently in the year 2021 that records the slant TEC from all the available constellations along with the scintillation indices and several other parameters [68]. Preliminary observations from this high-end monitoring unit confirmed instances of scintillations and loss of lock scenarios due to intense scintillation activity in October 2022 [69; 70; 71]. However, most of the earlier investigations conducted at this particular location are based on observation, modeling and forecasting of GPS scintillation indices and belong to the previous solar cycle, i.e., Solar cycle 24. To the best of our knowledge, the multi-constellation scintillation indices and TEC depletion characteristics are barely explored at this location. Hence, in this work, we focus on probing the presence of EPBs over the present location by analyzing the satellite to the receiver slant TEC (sTEC) depletions as well as phase and amplitude scintillation indices across multi-constellation and multi-frequency GNSS signals prevailing during the most geomagnetically disturbed days (Dst \(<-100\) nT) under the 25 th solar cycle. It involves addressing the influence of geomagnetic storms on EPBs in the equinoctial storm days when the regular EPB occurrences prevail over low latitudes. Our results revealed the strengthening of EPBs on the 23 April 2023 storm event amongst the three most disturbed equinoctial geomagnetic periods considered in this study by substantiating the relationship between TEC depletion and scintillation intensities across multi-constellation and multi-frequency GNSS signals which are discussed in detail in the rest of the sections. Section 2 provides Materials and Methods, and Section 3 provides Results and Discussion followed by Summary and Conclusions in Section 4.
# GPS + BDS Network Real-Time Differential Positioning Using a Position Domain Estimation Method
## 4 Discussion
It should be noted that, using the same weighting strategy for both GPS and BDS satellites is not appropriate in some cases. A proper weighting strategy must be found to provide a better positioning performance of GPS + BDS solution. The least-squares variance component estimation [43], the cross correlations between different frequencies and the time correlations between epochs have been considered to build stochastic models of GPS and BDS [44]. [PERSON] et al. [45] further pointed out that different elevation-dependent models should be used for GEO (Geostationary Earth Orbit), IGSO (Inclined Geosynchronous Satellite Orbit) and MEO (Medium Earth Orbit) satellites in BDS. Following the above researches, a proper stochastic model for GPS + BDS combination will be investigated in the future. The corrections of the BDS satellite-induced code bias obtained by the model in [PERSON] et al. [28] may be different from those obtained by other models (e.g., the model in [PERSON] et al. [46]). The difference is caused by the different data and methods used in modeling, and it is usually small [47]. Since the BDS IGSO and BDS MEO satellite-induced code biases can almost be canceled by single-differencing between receivers [48], and the maximum theoretical residual of BDS GEO satellite-induced code bias after single-differencing between receivers is only a few centimeters for 300 km baseline [47]; the model differences can hardly influence the differential positioning.
# The Current Development Status of Agricultural Machinery
## 5 Summary and Future Perspectives
### Integrated Intelligent Perception Systems
#### 5.3.1 High-Precision and Adaptive Upgrades for Leveling Systems  
Leveling systems are essential components for ensuring the safe operation of agricultural machinery in hilly and mountainous terrains. Their performance has a direct impact on machine stability, operational accuracy, and safety within complex topographies. In environments characterized by steep slope variations and diverse soil conditions, traditional leveling systems often demonstrate slow response times and low precision, which can result in machinery tilt, diminished operational quality, or even rollover accidents.  
To address these challenges, research into high-precision adaptive leveling systems emphasizes the optimization of attitude adjustment mechanisms and control algorithms. By incorporating technological innovations such as multi-sensor fusion and advanced control strategies, these enhanced systems achieve millisecond-level response times and ultra-high leveling precision. This significantly improves machinery stability, operational safety, and travel performance in hilly regions.  
Such advancements not only ensure operational safety but also enhance the mechanization level and economic efficiency of agricultural production in these areas, thereby laying a foundation for the intelligent development of modern agricultural equipment. However, domestic research in this field remains at an early stage. A comprehensive systematic analysis of machinery dynamics--integrating mathematical principles with mechanical and kinematic theories--is necessary to further advance the development of intelligent and reliable leveling control systems tailored to meet the unique demands posed by hilly terrain.
## 3 Data Collection and Processing
### Coupling Mechanism Analysis
#### 3.1.1 Investigation into the Mechanism of Blast Furnace Permeability  
Blast furnace permeability denotes the ability of gas to flow within the furnace. It is influenced by various factors, including pore space size, connectivity, and resistance to gas flow within the particle accumulation present in the blast furnace. The formation  
Figure 2: Blast furnace structure.  
mechanism of blast furnace permeability is related to the following factors, as shown in Figure 3[17; 18; 19]:  
1. Physical properties of the charge particles: The physical characteristics of the blast furnace charge, including particle size, shape, and surface roughness, impact the interparticle compactness within the blast furnace, consequently influencing its permeability.
2. Blast furnace operating parameters: The operational variables of the blast furnace encompass factors such as temperature, gas flow rate, and air outlet conditions. These parameters exert a direct influence on the gas flow dynamics and the configuration of particle accumulation within the blast furnace, consequently impacting its permeability.
3. Charge properties: The mineral composition, bonding characteristics, and other properties of the blast furnace charge play a crucial role in the flowability and discharge behavior of the charge material. Consequently, these properties have a direct impact on the permeability of the blast furnace.
4. Cylinder structure: The configuration of the blast furnace cylinder also influences the gas flow patterns and the arrangement of particle accumulation within the furnace. These factors, in turn, have an impact on the permeability of the blast furnace.
5. Furnace dust: There are a large number of furnace dust particles in the blast furnace, and these particles affect the gas flow state and the arrangement of particle accumulation within the blast furnace, subsequently impacting its permeability.  
The formation mechanism of blast furnace air permeability is an interrelated and complex issue, which is related to various factors such as physical properties of charge particles, blast furnace operating parameters, charge properties, furnace cylinder structure, and dust in the furnace. Gaining a comprehensive understanding and effectively managing these factors can significantly enhance the air permeability of the blast furnace, thereby ensuring smooth and uninterrupted production.
## 2 Methods  
### Extended Dual-Focus Optics Configuration  
A diagram showing the overall combination of the bifocal plane imaging system and lens oscillation scheme proposed in this study is as demonstrated in Figure 2. Based on the dual-focus optics scheme [11], the camera image sensor can simultaneously collect the images acquired from two optical paths having slightly different focal lengths, at a certain imaging position determined by the axial position of the objective lens. Here, \(\epsilon\) is the difference in positions of image planes established by adjusting the relay lens position. Furthermore, the distance between two adjacent imaging positions, \(d\), can be set and adjusted by tuning the amplitude of the piezo actuator that accommodates the objective lens, which is driven by an input voltage. At first glance, it seems to be advantageous to set the imaging positions broadly as possible along the axial direction to cover the entire range of the cell.  
Figure 2: Overall concept of combined dual-focus optics with objective lens oscillation. (**A**) Schematics of optical path and objective lens-mounted piezo actuator system. For dual-focus optics in fluorescence microscopy, light reflected from the labeled organelle in the sample cell is divided by two optical paths having different focal lengths, adjusted by the position of relay lenses [11]. The difference in focal length created by the lens position determines the distance \(\epsilon\). The distance \(d\) is determined by the axial position of objective lens, the step size of which can be controlled by an external controller; (**B**) Cell images taken at each imaging positions for \(\epsilon=d=1.0\,\mathrm{\SIUnitSymbolMicro m}\).  
However, there exists a trade-off between the position detection resolution and the imaging range. First of all, because the axial position of the moving organelle is computed based on the intensity ratio acquired from the pair of the focal planes, the separation between focal planes, \(\epsilon\), should be determined considering the target organelle size and the calculation accuracy in the range of calibration [11]. In addition, in the case where \(\epsilon\ll d\), not only does the probability of missing or misconceiving the target organelle between the nearest imaging positions significantly increase, but also the resolution of axial position calculation cannot be improved upon the combined imaging scheme. Therefore, investigation on the value of \(\epsilon\) and design of the distance \(d\) are prerequisites for an efficient and accurate imaging. First, \(\epsilon\) should be determined so as to yield fine resolution for detection of the target particle position. Then, the distance between the adjacent imaging positions which is determined by the objective lens oscillation step, \(d\), can be designed to vertically concatenate the axial range evaluated based on \(\epsilon\).
# Geospatial Simulation System of Mountain Area Black Ice Accidents
## 5 Discussion  
As described in the previous chapter, our black ice risk assessment system anticipated 71% of black-ice-related traffic accidents based on meteorological, spatial, and road structure information. That is to say, if the system had been in operation during the testing period, precautionary practices or warnings could have been established for 71% of accidents. This result has significance in that our system can prepare a preventive measure for black-ice-related traffic accidents occurring on local roads. This is because, unlike other existing systems that deal with relatively large regional units due to the sparse distribution of the observation equipment, the proposed system used local road management systems and local topographic maps. In addition, our system enabled localized special treatment as it segmented the road into three cases according to the possibility of black ice formation based on real-time hillshade.  
The black-ice-related issues are mainly addressed in countries that have specific regional and climatic characteristics. However, the fatality rate of black ice in traffic accidents is much higher than that of snow in those countries. According to the Korea Transport Institute, the number of deaths from traffic accidents caused by black ice was 170 from 2015 to 2019, which is far higher than that of traffic accidents caused by snow (46 people), as shown in Table 2[27]. This phenomenon is similarly found in other countries [28]. In this respect, our system is expected to contribute to reducing traffic accidents and deaths caused by black ice in countries with similar climatic and topographical conditions to Korea.
## 3 Temporal Discretization and Time Discontinuous Galerkin Finite Element Method  
### Time Discontinuous Galerkin Finite Element Method  
The final matrix form of the fluid-solid interaction problem can be rewritten as  
\[\mathbf{M}\ddot{\mathbf{d}}(t)+\mathbf{C}\dot{\mathbf{d}}(t)+\mathbf{K}\mathbf{d}(t)=\mathbf{f}(t),\;\;\;\; \;t\in I=(0,T) \tag{15}\]  
In which,  
\[\mathbf{M}=\begin{bmatrix}\mathbf{M}_{s}&0\\ 0&\mathbf{M}_{f}\end{bmatrix};\;\mathbf{C}=\begin{bmatrix}\mathbf{C}_{11}&\mathbf{C}_{12}\\ \mathbf{C}_{21}&\mathbf{C}_{22}\end{bmatrix};\;\mathbf{K}=\begin{bmatrix}\mathbf{K}_{11}&\mathbf{ K}_{12}\\ \mathbf{K}_{21}&\mathbf{K}_{22}\end{bmatrix};\] (16) \[\mathbf{f}(t)=\begin{bmatrix}f_{u}\\ f_{uL}\end{bmatrix}\stackrel{{..}}{{\
ot\!\!\!\!\!\!\!\  
The weak form of the semi-discrete equation and the constraints of the system \(\dot{\mathbf{d}}-\mathbf{v}=\mathbf{0}\), as well as the discontinuity conditions \(\mathbf{d},\mathbf{v}\) for the typical time subdomain can be expressed as  
\[\int\limits_{\mathbf{l_{n}}}\mathbf{\delta v^{T}}\big{(}\mathbf{M}\dot{\mathbf{v}}+\mathbf{C}\mathbf{v}+ \mathbf{K}\mathbf{d}-\mathbf{Q}\big{)}\mathbf{d}\mathbf{t}+\int\limits_{\mathbf{l_{n}}}\mathbf{\delta d^{T} }\mathbf{K}\big{(}\dot{\mathbf{d}}-\mathbf{v}\big{)}\mathbf{d}\mathbf{t}+\mathbf{\delta d^{T}}\mathbf{K} \big{[}\mathbf{d_{n}}\big{]}+\mathbf{\delta v^{T}}\mathbf{M}\mathbf{v_{n}}\big{]}=\mathbf{0} \tag{22}\]  
Substituting Equations (11) and (13) into Equation (14) yields the following DGFM matrix equation for solving from the independent changes.  
\[\mathbf{d}^{+}_{n}=\mathbf{d}^{-}_{n} \tag{23}\]  
\[\begin{bmatrix}\mathbf{M}+\frac{\Delta t}{6}\mathbf{C}-\frac{\Delta t^{2}}{12}\mathbf{K}&- \frac{\Delta t}{6}\mathbf{C}-\frac{\Delta t^{2}}{12}\mathbf{K}\\ \frac{\Delta t}{2}\mathbf{C}+\frac{\Delta t^{2}}{3}\mathbf{K}&\mathbf{M}+\frac{\Delta t}{2 }\mathbf{C}+\frac{\Delta t^{2}}{6}\mathbf{K}\end{bmatrix}\begin{Bmatrix}\mathbf{v}_{n}\\ \mathbf{v}_{n+1}\end{Bmatrix}=\begin{Bmatrix}\mathbf{f}^{\prime}_{1}-\mathbf{f}^{\prime}_{2 }+\mathbf{Mv}^{-}_{n}\\ \mathbf{f}^{\prime}_{1}+\mathbf{f}^{\prime}_{2}+\mathbf{Mv}^{-}_{n}-\Delta t\mathbf{K}\mathbf{d}^{ -}_{n}\end{Bmatrix} \tag{24}\]  
\[d^{-}_{n+1}=\mathbf{d}^{-}_{n}+\frac{1}{2}\Delta t(\mathbf{v}_{n}+\mathbf{v}_{n+1}) \tag{25}\]  
In which, \(\mathbf{f}^{\prime}_{1}=\frac{\Delta t}{3}\mathbf{f}^{\prime}_{n}+\frac{\Delta t}{6} \mathbf{f}^{\prime}_{n+1}\), \(\mathbf{f}^{\prime}_{2}=\frac{\Delta t}{6}\mathbf{f}^{\prime}_{n}+\frac{\Delta t}{3} \mathbf{f}^{\prime}_{n+1}\).  
The above formula shows that the continuity of the node displacement vector \(\{\mathbf{d}\}\) can be automatically satisfied at any time. While the nodal derivative vector \(\{\mathbf{v}\}\) at discrete time level is discontinuous.
# Susceptibility to Expansive Reactions of a _Greener_ Uhpc: Micro to Macro-Scale Study
### Research Significance and Objectives  
Alkalis silica reaction (ASR) is a slow, expansive reaction which can take 10-15 years to manifest in concrete structures or elements [44; 45]. However, deleterious expansions associated with ASR have been recurrently reported among the main causes of deterioration of important concrete structures and infrastructures, such as dams, nuclear/power plant, pavements, bridges, walls, and barriers. This expansive deleterious reaction can gradually reduce the service life, the load-carrying capacity, and even the safety of the concrete structures, which can lead to high replacement costs or even the structure's demolition [46; 47; 48; 49; 50; 51]. Due to the high cement content employed, the equivalent alkali content (Na2 Oeq) in UHPFRC mixtures usually exceeds 8 kg/m\({}^{3}\). Thus, it seems necessary to evaluate the risk of damage due to ASR in UHPFRC. Due to the very low permeability of UHPFRC, the external sulphate attack is not expected, however, it needs to be confirmed. Sulphate attack is rarely the only phenomenon responsible for concrete deterioration [51]; it often co-occurs when reactive aggregates are used and are typically observed in structures or elements exposed to sulphate-rich solutions, such as rivers, seawater, and groundwaters [52]. Considering the rehabilitation or strengthening of sea structures has been an exciting application field for UHPFRC, durability against expansive reactions must be evaluated. However, it is still missing from the literature survey.  
In CONSTRUCT-LABEST, research projects have been conducted to make UHPFRC a more practical, cost-effective, eco-efficient, and widely accepted material/solution. One of the aims was to develop a UHPFRC using locally available raw materials, incorporating local non-value-added by-products or waste materials and simple manufacturing and curing methods [53; 54; 55]. Those features can reduce the cost and ecological footprint of UHPFRC and contribute to a circular economy. The current work evaluated the durability of the non-property and greener UHPC (with no fibres) against expansive reactions, namely, alkali-silica reactions and expansion due to external sulphates, by macro and micro-scale integrative analysis. At the macro level, linear expansion tests were performed according to ASTM C 1260 and LNEC E\(-\)364 to access the mitigation effect of UHPC against ASR and external sulphates, respectively. After ASR and sulphate tests, SEM observations and EDX analysis were carried out. In addition, porosity and microstructure analyses on sound UHPC samples were performed.
## 2 Results and Discussion
### Aroma Series  
According to [PERSON] et al. [30], wine aroma could be categorized into different series by the aroma wheel. Volatile compounds with OAV values higher than 0.1 were used to evaluate each  
Figure 2: Principal component analysis of volatile compounds (OAV \(>\) 1) in wine samples with different clarification treatments.  
aroma series in wine samples. In this experiment, icewine aroma was found to consist of floral, fruity, fatty, earthy, spicy, vegetative, and pungent flavor. The floral and fruity aromas were the dominant aromatic categories of 'Italian Riesling' icewine, which were mainly contributed by some terpen (including rose oxide, linalool, citronellol, \(\beta\)-damascenone, and geranyl acetone) or esters (including ethyl butyrate, isoamyl acetate, ethyl hexanoate, ethyl octanoate, and ethyl decanoate compounds) (Table 3). Another study also showed that the compounds with the highest odor activity for icewines were \(\beta\)-damascenone, 1-octen-3-ol, ethyl octanoate, cis-rose oxide and ethyl hexanoate [35], which is similar to the results of this study. Although all tested wine samples exhibited a similar aroma series order, the content of aroma series was different which indicated that clarification treatments played an important role in altering the aromatic quality of the tested wines.  
As can be seen from Figure 3, the floral was mainly influenced by mechanical clarification, where MF showed the greatest decrease followed by CF treatment. There were no observed differences between BT and SP fining wines. Fruity was the second largest category of icewine samples, in which MF treatment showed the largest decrease, followed by BT fining, while there was no significant difference between SP and CF wine samples. Fatty, earthy, spicy, vegetative, and pungent flavors could also improve wine complexity. These flavors may be contributed by fatty acids, 1-Octen-3-ol, volatile phenols, C6, and alcohol compounds, however, high levels of these flavors could also negatively influence wine aroma features [33; 35; 36]. A significant difference in these flavors was found between the control and clarified wines with the exception of earthy (not found in SP wine). MF wine showed the greatest decrease in these flavors, while CF treatment showed the most fatty, earthy, spicy and pungent flavors. Another interesting phenomenon is that clarification treatments showed the least influence in vegetative flavor, where only MF treatment showed a significant difference, but the mechanism still remains to be further studied.
# Reversible Hydrogen Storage Using Nanocomposites
## 2 Nanocomposite Materials for Hydrogen Storage
### Nanoengineered Complex Hydrides (LiBH4/MgH2)  
The dramatic enhancement of kinetics of MgH2 has also been explored through a reaction with small amounts of LiBH4 [57]. Though the MgH2 admixing increases the equilibrium plateau pressure of LiNH2 [58] or LiBH4 [59], nanoengineering of the ingredient hydrides are not widely reported. Nanocrystallinity of the ingredient hydrides and nanocatalytic doping are the two innovative methodologies that have been proposed to explore their impacts on the overall hydrogen storage behavior of complex hydrides. The mechanochemical milling discussed previously helps for the particles pulverization, in this case, MgH2 crystallites downsize into micro or nanocrystalline phases and thus leads to a lowering the activation energy required for dehydrogenation [60]. The activation energies of the hydrogenation for bulk MgH2, mechanically milled MgH2 and nanocatalyst doped MgH2 are schematically shown in Figure 10a.  
Figure 10a also demonstrates the effect of nanocatalyst doping on the hydrogenation and dehydrogenation behavior of MgH2. The transition metal nanoparticle clusters during the mechano-chemical processing disperse uniformly within the micro/nanocrystalline grains of MgH2 and serve as nuclei for H2 molecular dissociation. An optimum level of the nanocluster catalyst density, for surface coverage, can be determined by finding the rate limiting steps for maximum storage capacity via volumetric measurements. Three different reaction pathway mechanisms can be evaluated for the nanocatalyst doped nanocrystalline complex hydride system. The flow chart shown in Figure 10b gives the reaction pathway mechanisms used to optimize the effective catalyst addition for improving the sorption characteristics.  
The reversible hydrogen sorption characteristics of the nanocrystalline complex hydrides are shown in Figure 11. An extended plateau region at which the maximum reversible hydrogen content is clearly seen from this figure. Moreover, the hydrogen capacity and the plateau pressure increase with a temperature up to 375 \({}^{\circ}\)C.  
Figure 10: (**a**) Conceptual model and (**b**) flowchart for the reaction pathway schemes of the plain, nanocrystalline, and nanocatalysts doped nanocrystalline LiBH4/MgH2 cluster.