esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Numerical Model Development and Experimental Validation
### Numerical Model Validation
#### 2.3.2 Machine Learning
\begin{table}
\begin{tabular}{c c c c c c} \hline  & **U1** & **U2** & **U3** & **U1 + U2** & **U1 + U2 + U3** \\ \hline Case 1671 N & 464.5 & 227.1 & 406.4 & 406.2 & 461.8 \\ \hline Case 1902 N & 169.8 & 166.2 & 166.5 & 169.0 & 161.4 \\ \hline Case 2465 N & 147.7 & 161.2 & 130.7 & 159.4 & 130.1 \\ \hline Case 2587 N & 137.0 & 173.4 & 144.7 & 163.2 & 195.7 \\ \hline Case 3192 N & 225.3 & 199.7 & 163.6 & 194.4 & 156.1 \\ \hline Case 4562 N & 205.9 & 221.8 & 140.1 & 201.3 & 197.9 \\ \hline Case 5291 N & 327.6 & 286.0 & 332.8 & 280.4 & 279.6 \\ \hline Case 5670 N & 250.2 & 308.3 & 299.5 & 245.0 & 246.6 \\ \hline Case 6678 N & 415.1 & 331.9 & 349.7 & 413.7 & 415.7 \\ \hline Case 6680 N & 347.4 & 303.1 & 317.6 & 379.2 & 324.9 \\ \hline Case 7301 N & 224.3 & 267.5 & 439.4 & 325.5 & 220.8 \\ \hline Average & 265.0 & 240.6 & 262.8 & 267.0 & 253.7 \\ \hline \end{tabular}
\end{table} 
Table 1: Average error for each validation case for the three Cartesian Axes plus two others that represent an average of the results in order to represent other intermediate directions. All data are represented in MPa. It is also important to note that the experimental cases shown in this validation had a very narrow shape and thus were subjected to many reflections, this shows the robustness of the method as it was capable of detecting damage and even detecting a few of the samples to extremely close values. This test demonstrates that the use of experimental and simulated data in conjunction allows for the correct identification of damage and thus validates the use of the simulated parameters.
# Pilot Study of Microplastics in Snow from the Zhetysu Region (Kazakhstan)
## 1 Introduction
Due to the geographical location of Kyrgyzstan, Tajikistan, and Uzbekistan within Central Asia and the presence of mountain systems there with stable snow cover and activities in valleys and foothills, it can be assumed that microplastics are also deposited in the snow cover of these regions, arriving both with air masses and from local sources. Thus, despite the lack of direct snow cover studies in these countries, indirect data indicate a high probability of contamination by microplastics. This requires targeted research concepts. This study aims to fill this gap by assessing the microplastic pollution of snow cover in Kazakhstan, in particular within the Zhetysu region, for the first time. The choice of the territory was determined by the combination of the high mountain relief, industrial load, and potential influence of atmospheric transport. The aim of the study is to identify the content, morphology, and polymer composition of microplastics in snow, as well as to determine possible sources of pollution previously unstudied under the conditions of Central Asia. In the last few years, separate studies have been conducted in Kazakhstan on microplastic contamination of various components of the natural environment, but no direct publications concerning the presence of microplastics in snow cover have been presented yet. In particular, in Akmola Oblast, studies were conducted at solid domestic waste land-fills, where the presence of microplastics in the environment was detected [27, 28]. Special attention was paid to surface waters and bottom sediments of lakes and rivers in the region. Microplastic particles were detected there too. Both micro- and macroplastic contaminants expressed by fragments of fishing nets, foam plastic, plastic bags, and bottles were detected in the high-mountain lake Markakol in the east of Kazakhstan [29]. Studies of snow cover contamination in Kazakhstan have not yet been conducted or published. Nevertheless, in the adjacent regions of the southern part of Western Siberia (Russia), microplastic particles were detected in snow samples in 16 out of 18 samples, including fibers, granules, and film fragments. The results confirm atmospheric transport of microplastics over long distances and their subsequent deposition in snow [30]. Also, in southeastern Kazakhstan (including areas of Zhetysu and Almaty oblasts), studies on other types of snow cover pollutants, such as heavy metals and polychlorinated biphenyls (PCBs), were previously conducted, which proves the suitability of snow as an indicator of atmospheric pollution [31-33]. These facts confirm the relevance and necessity of comprehensive studies of microplastics in the snow environment of Kazakhstan, especially in high-mountainous and industrially loaded areas, where snow is capable of accumulating particles coming from both local sources and as a result of transboundary air mass transport.
# An In-Line Coaxial-to-Waveguide Transition for Q-Band Single-Feed-Per-Beam Antenna Systems
###### Abstract  
An in-line transition between a coaxial cable and rectangular waveguide operating in Q-band (33-50 GHz) is presented. The aim of the work is to minimize the modifications in the waveguide to the strictly necessary to overcome the manufacturing issues due to the high frequencies involved. In addition, the transition is compact and it does not increase the space occupation on the transverse section, this suggests its application in horn antennas clusters arrangement. The operating principle consists of both a modal conversion and an impedance matching between the devices. The modal conversion is realized in an intermediate region, where the coaxial penetrates in the waveguide: the device geometry is designed so that the electric field in the transition is a trade-off between the TEM mode of the coaxial and the TE\({}_{10}\) of the guide. A shaped waveguide backshort and a reactive air gap in the coaxial cable co-participate to achieve the matching. An optimized Chebyshev stepped transformer completes the transition to fulfil the impedance mismatch with the full waveguide. The design issues and technological aspects are considered. The influences of the feeding pin misalignment, the presence of groove is included in the analysis and these practical aspects are discussed and numerically validated via the scattering parameters analysis of the proposed design. The return loss is higher than 25 dB over the whole Q-band.  
transition; waveguide; coaxial; impedance matching; end-laucher; ridge +
Footnote †: journal: Physics Letters A
## 3 Real-Building Case Study
### Pool of Data Imputation Methods  
As introduced in Section 2, the developed framework applies the ensemble method for missing data imputation, where multiple imputation methods are used as candidate methods to test the performance on the validation dataset. The method with the best validation accuracy will be the final imputation method for a specific sensor Table 4. lists a pool of the candidate data imputation methods for the real-building case study. The ensemble method is independently conducted for each sensor, meaning that one single imputation method will be selected for each sensor. As can be seen from Table 4, there are five categories of the imputation methods in the pool for the case study: (1) simple interpolation using the next, last, or nearest valid observation to fill the missing data gap (bill, ffill, and nearest); (2) linear interpolation (linear); (3) nonlinear interpolation (quadratic and cubic); (4) piecewise splines (piecewise_polynomial, from_derivatives, pchip, akima); and (5) machine-learning-based interpolation techniques (artificial neural network, or ANN). These data imputation methods are realized by Python libraries including pandas, scipy, and sklearn. It is worth mentioning that the parameters of each  
Figure 4: Example of one real missing data point and one generated validation data point in the sensor chiller energy meter.  
method from Python libraries are default and untuned in the case study. The case study is just a showcase or example of the ensemble method with a different single imputation algorithm. The single algorithms can be tuned to get better performance, and chances are that the ensemble method can also achieve better performance accordingly. However, the focus of this paper is not tuning of single algorithm so only default parameters are considered. In the next section, the results and discussion of applying the developed framework on the real-building case study are introduced.
# Experimental Research on In Situ Uniaxial Tensile Response of Silica-Based PLC Optical Splitters
###### Abstract  
In this study, the mechanical and optical properties of silica-based planar lightwave circuit (PLC) optical splitters under uniaxial tensile loading are studied by building an in situ experimental test platform. The tensile test results revealed that the adhesively-bonded fiber array-PLC chip joints are weak areas of the PLC optical splitter. Combined with the real-time monitoring of the optical performance index insertion loss (IL) during the tensile test, it was found that the changing trend of \(\Delta\)IL-time curves is related to the deformation, damage, and debonding process of the weak area. Based on the experimental results and phenomena, the correspondence between \(\Delta\)IL at 1.55 \(\upmu\)m wavelength and the damage degree of PLC optical splitters is established, that is, \(\Delta\)IL in (\(-\)5 dB; 0 dB], (\(-\)15 dB; \(-\)5 dB], and (\(-\infty\), \(-\)15 dB] belong to light damage, moderate damage, and severe damage, respectively. This research can provide a useful reference for damage characteristics analysis and reliability design of PLC optical splitters.  
failure mode; in situ monitoring; insertion loss; PLC optical splitter; tensile test +
Footnote †: journal: Applied  
0
Footnote 0: Copyright** © 2022 by the authors. Liconsee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/)]([https://creativecommons.org/licenses/py/4.0/](https://creativecommons.org/licenses/py/4.0/))).
## 3 Results and Discussion
### Ascorbic Acid Content  
The content of vitamin C in _Kalanchoe daigremontiana_ significantly affects the quality of the raw herbal material. The concentration of ascorbic acid in plant material depends on the plant species, the conditions of cultivation, as well as the activity of abiotic factors occurring during plant growth. One of the abiotic factors affecting vitamin C content is gaseous ozone; applied in an appropriate way, it modifies the levels of this compound in the raw material [23].  
Ozone treatment applied to alligator plants affected the content of vitamin C in the leaves (Figure 3). The value, however, was varied relative to the concentration of gaseous ozone applied and the duration of alligator plant exposure to its activity. Ozone treatment applied at a low rate of 5 ppm, irrespective of the process duration, contributed to a decrease in vitamin C content in the leaves. This decrease may have resulted from the activation of ascorbate oxidase, which is responsible for the degradation of ascorbic acid [33].  
Figure 1: Antioxidant activity ABTS (2,2\({}^{\prime}\) -Azino-bis-(3-ethylbenzothazoline-6-sulfonic acid) test (**A**) and DPPH (2,2-Diphenyl-1-picrylhydrazyl) test (**B**) in _Kalanchoe daigremontiana_ leaves depending on the duration of ozone treatment (n = 20): differences between the results for duration of ozone treatment on specific days are marked with small letters, and differences between dose of ozone (ppm) measurement are marked with capital letters; significance level is defined as \(p\) < 0.05.  
On the other hand, the samples treated with gaseous ozone at a higher rate of 10 ppm for 5 or 10 min were found with higher contents of vitamin C. However, the highest increase of 7%, compared to the content in the leaves of untreated plants (0 ppm 0 min), was observed in the samples exposed to ozone for 10 min.  
The effect of ozonation on ascorbic acid content was also reported by other researchers. [PERSON] et al. [34] exposed raspberries to gaseous ozone, with a concentration of 0.3 and 0.9 mg L\({}^{-1}\) for 60 and 120 min. The researchers found that the contents of vitamin C in the fruit decreased in storage as a result of L-ascorbic acid oxidation into dehydroproascorbic acid. However, the decrease was significantly lower in the fruit subjected to treatment with gaseous ozone.  
Figure 3: Ascorbic acid content in _Kalanchoe diagramontiana_ leaves depending on the duration of ozone treatment (n = 20): differences between the results for duration of ozone treatment on specific days are marked with small letters, and differences between dose of ozone (ppm) measurements are marked with capital letters; significance level is defined as \(p<0.05\).  
Figure 2: Total polyphenolic content in _Kalanchoe diagramontiana_ leaves depending on the duration of ozone treatment (n = 20): differences between the results for duration of ozone treatment on specific days are marked with small letters, and differences between dose of ozone (ppm) measurements are marked with capital letters; significance level is defined as \(p<0.05\).
## 4 Proposed LVRT Enhancement Strategies
### Reactive Power Injection Scheme
The algorithm first checks the phase fault conditions individually, based on the RMS value of the voltage value. When the PCC voltage drops below 0.9 p.u, the SPV system injects the active power (P) and reactive power equal capacity. If the PCC voltage lies between 0.5 and 0.9 pu, the active power is fixed to the nominal value, and the reactive power during LVRT is represented in Q_LVRT. Otherwise, if the voltage is below 0.5 pu, the active power is disabled and the whole capacity of the inverter is used to inject the maximum reactive power (Qmax) into the grid to boost the PCC voltage. ```
1:Measuring Vg,rms value in per unit (pu);
2:Nominal Vg,rms = = 1.01;
3:If (Vg,rms < 0.9)
4:P = = P* && Q = = Q*; % P* and Q* are the post-fault active and reactive powers
5:else if (0.5 < Vg,rms < 0.9)
6:P = = P* && Q = Q_LVRT; % P is the pre-fault active power and Q_LVRT is the Q at LVRT
7:else if (Vg,rms < 0.5)
8:P = = 0&& Q = Q_max; % Q max is the maximum reactive power injection into the grid
9:else

detecting Vg-rms value in per unit (pu);
10: return to step 3
```  
**Algorithm 1** Proposed LVRT method based on reactive power injection.
# A Low Phase Noise Frequency Synthesizer with a Fourth-Order RLC Loop Filter
###### Abstract  
The current work employs the HMC830 phase-locked loop chip to design a frequency synthesizer operating in the L-band. The frequency synthesizer can provide a local oscillation signal for the RF receiver front end. This article employs the phase-locked synthesis technique to describe the design scheme. Due to the advantages of the passive loop filters, such as simplicity, low cost, and low phase noise, a passive fourth-order RLC loop filter is proposed to improve the output signal quality and reduce phase noise. The performance of this loop filter is compared with the passive fourth-order RC loop filter. The effects of these two loop filters on phase noise, loop capture time, and spur suppression are analyzed. Subsequently, the design scheme, simulation analysis, and test results of the frequency synthesizer are presented under these two loop filters. The test results indicate that the passive fourth-order RLC loop filter outperforms the passive fourth-order RC loop filter; its output signal phase noise is higher than \(-100\) dBc/Hz@1 kHz, loop capture time is less than \(100\) us, and spur suppression is better than \(60\) dBc. This frequency synthesizer can provide high-performance local oscillation signals for wireless communication equipment such as transmitters and receivers. It meets the application requirements of many radio communication circuit structures and has good application prospects.  
PLL; loop filter; phase noise; frequency synthesizer +
Footnote †: journal: Electronics Letters  
18 November 2022  
Revised: 22 December 2022  
Accepted: 29 December 2022  
Published: 2 January 2023
# Direct-Write Spray Coating of a Full-Duplex Antenna for E-Textile Applications
## Materials and Methods
### Dielectric Constant Test  
Traditional techniques for permittivity measurements at microwave frequencies can be divided into non-resonant methods and resonant methods [36]. Non-resonant methods mainly use transmission/reflection measurements, but have limited resolution. For our analysis, we used the split post dielectric resonator (SPDR) method to test the permittivity of the samples without damaging them. A 2.45 GHz SPDR was connected to a two-port vector network analyzer (VNA) by high-precision coaxial cables to analyze the samples [37]. The device resonates at a specific frequency with a quality factor (Q-factor) over 2000. Because of the high Q factor, it is more sensitive to the dielectric samples than a conventional coil-and-capacitor resonant circuit [38]. The sample size requirement for the SPDR test is at least 5 cm \(\times\) 5 cm, and the sample thickness should be less than 2 mm. The dielectric constant measurements were repeated five times. This method can provide rapid and accurate results at high frequency.
## 3 The Proposed Model and Methods
### ANN-Based Embedded Data-Driven Controller Design  
The primary advantage of data-driven controller design lies in its approach of handling the impact of control variables on the outputs to be controlled through a black box model, rather than analyzing the system with its sub-components. The fundamental starting point of data-driven controller design involves establishing a data acquisition setup to collect the necessary data for controller design and collecting discrete data in a uniformly randomized manner.  
The system to be controlled using proportional pressure variation is a pressing unit. The system consists of a PAM serving as a single-acting actuator, along with two springs employed to accelerate the return to the initial position. Additionally, there is a mass constructed of a rigid aluminum block that interconnects all components within the system. In the pressing unit, the control variable is the compressed air to be applied with the assistance of a proportional regulator. The pneumatic schematic of the PAM used as an actuator is illustrated in Figure 5.  
Figure 4: Modular pressing unit: (**a**) physical system; (**b**) CAD model; (**c**) system model.
## 3 Results and Discussion
### Disturbance Boundary of TVDI-CFS from Open-Pit Mine  
The mean TVDI-CFS curve within the 1000 m buffer zone was fitted using a Logistics function (Figure 7), which showed different disturbance boundaries in various directions. The closer to the open-pit mine area boundary, the lower the TVDI-CFS values and the higher the surrounding SM. The TVDI-CFS values in most directions showed clear Logistic fitting, with R\({}^{2}\) values above 0.90, indicating that the mining impacts SM decay with distance in a predictable and nonlinear manner. The \"SW\" direction, however, showed significant anomalies with substantial fluctuations, reflecting the complexity of the local environment that requires further consideration of other influencing factors. The spatial extent of the disturbance was observed to range from approximately 420 m to 660 m (Figure 8), with the greatest disturbance observed in the \"E\" direction at 660 m and the shortest in the \"N\" direction at 420 m. This variation is hypothesized to be linked to topography, soil type, and the diffusion direction of emissions from the mining operations. Open-pit mining activities exhibit a distance decay trend, with high disturbance levels concentrated near the mine boundary and lower levels observed further away. These findings align with previous studies, which indicate that open-pit mining significantly alters terrain, landforms, and hydrological processes [53; 54; 55], thereby affecting SM dynamics, as observed in regions like eastern Inner Mongolia, where reduced vegetation cover and increased soil porosity enhance SM levels by promoting precipitation infiltration, and in the Qinghai-Tibet Plateau region, where changes in the local hydrological regime due to mining activities also increase SM in surrounding areas [56].  
Figure 6: Correlation analysis chart between TVDI and CLDAS-V2.0.
# Numerical Study on Scale Effect of Repetitive Plate-Loading Test
## 1 Introduction
In addition, although the repetitive plate-loading test was conducted in the same zone, the compaction and status of the subgrade were not exactly the same, which indicated that further studies are required as supplementary validation. Therefore, in the present study, a numerical analysis was conducted, and a correction factor for the scale effect of the loading plate of the repetitive plate-loading test was proposed through a parameter study on the diameter of the loading plate to mitigate the limitations of the aforementioned field-verification test. The results were compared with those of the existing field-verification test, and the correction factor was investigated according to the subgrade condition by classifying the soils based on the cohesion and friction angle.
## 3 Results and Discussion
### SEM Morphology of the Obtained Powders  
To verify the morphology, SEM images of the powders heat-treated at 500 \({}^{\circ}\)C and 700 \({}^{\circ}\)C were obtained (Figure 2a-f). In addition, a comparison of their morphology with those of nonannealed samples was made. The SEM images of the samples were taken at the same magnification, with a marker of 5 \(\upmu\)m. The SEM studies of the samples show different microstructural features, depending on the TiO\({}_{2}\)/ZnO molar ratio. Additionally, all the micrographs indicated that the particles obtained by the sol-gel method exhibited strong agglomeration and a less porous structure. The images of as-prepared TiO\({}_{2}\) and 90 TiO\({}_{2}\)/10 ZnO showed similarity in their particle shapes (Figure 2). These particles exhibited a plate-like or irregular shape. The estimated particle sizes varied between 15 and 80 \(\upmu\)m. However, the length of time of the annealing did not change the surface morphology of the TiO\({}_{2}\) powders. Considering the obtained results, it can be generalized that varying the annealing temperature did not significantly influence the particle size of TiO\({}_{2}\)-containing powders. Irrespective of the used component ratio of the synthesized species, the obtained data are similar to those obtained by other authors [33].  
Energy-dispersive X-ray spectroscopy was performed to confirm the presence of O, Ti, and Zn in the three catalysts: TiO\({}_{2}\), 90 TiO\({}_{2}\)/10 ZnO, and 10 TiO\({}_{2}\)/90 ZnO. A homogenous distribution of all the elements can be observed in the investigated samples, along with  
Figure 2: SEM images of the samples annealed at 500 \({}^{\circ}\)C: TiO\({}_{2}\) (**a**), 90 TiO\({}_{2}\)/10 ZnO (**b**), and 10 TiO\({}_{2}\)/90 ZnO (**c**). SEM images of the samples annealed at 700 \({}^{\circ}\)C: TiO\({}_{2}\) (**d**), 90 TiO\({}_{2}\)/10 ZnO (**e**) and 10 TiO\({}_{2}\)/90 ZnO (**f**).  
peaks that signify oxygen, titanium, and zinc. No impurities were detected in the EDS spectra, which confirms the high purity of the catalysts (Figure 3).