esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Substrate-Integrated Waveguide Leaky-Wave Antenna Design
In this SIW LWA design, a very narrow open-stopband of less than 23 MHz is achieved thanks to the unit cell asymmetry. Furthermore, the design exhibits an almost linear dispersion slope with a similar gradient for the LH and RH regions up to a phase difference of \(\pi/2\). Thus, within the operational bandwidth from 50 to 70 GHz, an almost linear relation between beam angle and radiation frequency is projected, when considering the beam steering behavior of LWAs [13]:  
\[\sin\theta\approx\beta_{-1}/k_{0}=\lambda_{0}/\lambda_{\mathrm{g}}-\lambda_{0} /D. \tag{1}\]  
In Equation (1), the dependence of the radiated beam angle \(\theta\) on the vacuum wave number \(k_{0}\) and the phase coefficient \(\beta_{-1}\) of the TE mode in the LWA is given. As denoted by the index, the modes radiated by periodic LWAs are of the \(n=-1\) space harmonic. The right side of the equation gives the beam steering behavior based on the vacuum wavelength \(\lambda_{0}\), the guided wavelength \(\lambda_{\mathrm{g}}\) and the periodicity \(D\). Since the sine function can be well approximated as linear for low angles, a linear gradient of \(\beta_{-1}\) will consequently yield approximately linear beam steering. In the next section, we want to verify the estimations on the SIW LWA beam steering behavior through antenna characterization and further provide the simulated and measured gain of the complete 12 unit cell periodic leaky-wave antenna.
## 4 Results and Discussion  
### Microstructure of Coating  
The coatings were cut into standard specimens of 10 mm \(\times\) 10 mm \(\times\) 8 mm and analysed with SEM. The etchant in this experiment was aqua regia mixed with HCl and HNO\({}_{3}\), with the volume ratio 3:1; the duration of corrosion was 15 s, and the results were shown in Figure 10. The metallographic graph of the overview of the cladding layer was shown in Figure 10a. It was found that a good metallurgical bonding was formed between the substrate and the cladding layer; additionally, there were few pores and cracks, which indicated the rationality of the method. Because the growth of the crystal morphology during solidification mainly depends on the value of \(G\)/\(R\)[9], where '\(G\)' means the temperature gradient of the liquid phase and '\(R\)' is the solidification rate of solid phase, the instantaneous value of \(G\)/\(R\) changes with the distance to the solidification interface. The cladding layer is divided into three parts: bottom, middle and top, each having a different micro-morphology [24; 25]. Figure 10b shows the bottom of the layer, and the input of laser energy. The surface temperature of the substrate increased rapidly and formed a larger temperature gradient between this layer and the base metal; meanwhile, the solidification rate was the lowest, so the flat interface and directional columnar dendrites were observed in this layer. In the middle of the layer, the solidification rate became higher and the transition region of cellular crystal and dendrite crystal appeared with a micro-segregation of the composition, which is shown in Figure 10c. As for the top of layer, the cooling rate reached the its peak and the microstructure showed an equiaxial grain structure (Figure 10d).  
Figure 10: SEM micrograph of the coating: (**a**) The overview of the cladding layer, (**b**) the bottom zone, (**c**) the middle zone and (**d**) the top zone.
###### Abstract
A viability PMA-qPCR (v-qPCR) has been recently published [18] and it integrates a dead-cell standard to compensate for the variable residual PCR signal of dead cells [19; 20]. As [21] reported in 2019, v-qPCR allows an efficient and a reliable quantification of viable thermophilic _Campylobacter_. Digital PCR (dPCR), as the third generation of PCR technology has been proven to offer a new approach for its absolute quantification of copies of target molecules [22; 23]. It offers an alternative to qPCR to obtain precise quantification of nucleic acids without a standard curve, and it is not dependent on the number of amplification cycles to determine the initial amount of nucleic acids in the sample [24; 25]. Chamber-based dPCR (cdPCR) and droplet-based dPCR (ddPCR) are presently two basic approaches for conducting dPCR. In ddPCR, the compartmentalization of the reaction mix is achieved by using plastic-consumables (generator cartridges) with ultra-thin capillaries (microfluidics) in order to prepare a water-in-oil emulsion prior to the PCR; heat stable droplets are formed [26]. Microfluidics, i.e., miniaturization of fluid-handling, has enabled the massively-parallel sample partitioning and the advent of dPCR platforms [27]. In ddPCR, the sample is partitioned into approximately 20,000 droplets before the PCR cycles, subsequently, each droplet consists of ideally single (or few) copies of the target molecules and some others contain no copy of target molecules [28]. The absolute number of target nucleic acid molecules contained in the original sample before partitioning can be calculated from the ratio of positive events to total partitions, using binomial Poisson statistics [24]. Partitioning the sample into droplets before PCR holds the potential to overcome the inhibitory effects present in the sample matrix [28]. Finally, ddPCR enables the detection and the quantification of even low copy numbers due to the independent end-point PCR reaction occurring on every droplet from the sample [29]. In the current study, the combination of the sample pre-treatment with PMA dye was explored prior to DNA extraction and quantification of viable _C. jejuni_ and _C. coli_ in a viability ddPCR (v-ddPCR). The v-ddPCR method was optimized successfully in-house, validated according to ISO 16140-2:2016 [30], and evaluated on naturally contaminatedchicken samples. The results showed a significant correlation between the v-ddPCR, the reference microbiological ISO [7], and the recently published v-qPCR methods [18]. Furthermore, the technical measurement uncertainty was assessed based on ISO 19036:2019 [31], using QuoData statistical analysis. Finally, v-ddPCR may be used as an additional technique for rapid and easy monitoring in routine applications.
###### Abstract
Most of the above-referenced studies indicate that the temperature of the heat transfer fluid flowing from solar collectors to the absorption cooling system chiller greatly affects the overall performance of the absorption cooling system. Schematics of proposed absorption cooling systems in most of the above-referenced studies clearly indicating that only one flow scheme for circulation of heat transfer fluid was used between storage tank to chiller (i.e., flow of HTF directly form the storage tank to the chiller's generator and then back to storage tank). As it is revealed from preceding studies [19; 20] that the performance of the chiller was mainly affected by the inlet temperature to the generator unit of the chiller. Therefore, the main idea of the current study is to examine different ways of feeding heat transfer fluid to the generator of the chiller and analyzed their effects on the performance of the cooling system. In the light of the above-reviewed literature, the lack of research related to various flow schemes of heat transfer fluid (HTF) between components of SACS is perceptible and still there have more options of different flow schemes for heat transfer fluid to enhance the system's performance. The general significance and core purpose of the current study is to compare all possible flow patterns of heat transfer fluid that can be exercised between the storage-chiller loop of SACS and analyze their effects on the performance of SACS and in doing so, obtain an optimized TRNSYS model by replacing an installed conventional compression chiller of 108 kW cooling capacity having COP value 3 (by Dunham-Bush manufacturer) in an educational building located at the city (having the highest monthly averaged radiations) of Pakistan and finally decide the flow scheme of best performance, with an efficient solar collector.
## Abbreviations  
The following abbreviations are used in this manuscript:  
AM Annual Maximum  
COMS/MI Communication, Ocean, and Meteorological Satellite/Meteorological Imager  
Envisat Environmental Satellite  
ERS-1 European Remote Sensing-1  
ERS-2 European Remote Sensing-2  
EVA extreme value analysis  
GPD generalized Pareto distribution  
GFO Geosat Follow-On  
IORS leedo Ocean Research Station  
IDM Initial Distribution Method  
IFREMER Institut Francais de Recherche pour l'Exploitation de la Mer  
IBTrACS International Best Track Archive for Climate Stewardship  
Jason-1 Joint Altimetry Satellite Oceanography Network-1  
Jason-2 Joint Altimetry Satellite Oceanography Network-2  
KMA Korea Meteorological Administration  
PoT Peak over Threshold  
PDF probability density function  
RMSE root-mean-square error  
SARAL Satellite for Argos and Altika  
SWH significant wave height  
TOPEX Topography Experiment
## 5 Conclusions  
Corrosion potentials both in standard test specimens and in test specimens with LFS became more negative as the humidity of the test specimens and the percentage of chloride ions increased, reaching values which indicate a probability of corrosion which is over 90% for chloride ion percentages above 0.4% by weight of cement.  
The corrosion rates increased with the humidity content of the test specimens and with the chloride ion percentage introduced at the time of kneading, both in standard test specimens and in those with LFS, reaching values characteristic of the active state for chloride ion percentages above 0.4% by weight of cement.  
The standard test specimens offered greater resistance to the passage of an electrical current than the LFS test specimens. The voltage necessary to maintain a constant current fell drastically on increasing the moisture content, increasing progressively as the degree of moistness of the test specimens decreased.  
Figure 8: Corrosion products in the test specimens without (**a**) and with LFS (**b**), with 2% chloride ions by weight of cement.  
Figure 9: i\({}_{\text{corr}}\) values of test specimens attacked by chlorides, in standard test specimens (MCC) and test specimens with LFS (MCE) after 546 days.  
The symptoms produced in standard test specimens with chloride ion percentages of 1.2% and 2.0% by weight of cement subjected to an accelerated corrosion process consisted of rust stains, initially coinciding with the central bar, which progressively lengthened until they occupied the lower face and the edge of the test specimens.  
The symptoms produced in test specimens with LFS with chloride ion percentages of 1.2% and 2.0% by weight of cement that underwent the accelerated corrosion process began with the appearance of rust stains that coincided with the central bar of the test specimens and spread over the upper and lower faces and the edge of the test specimens. The pressure exerted by the corrosive products caused progressive cracking of the test specimens, becoming more evident in the test specimens with a greater chloride ion percentage.  
The presence of chlorides in the test specimens produced localized pitting in the steel rebar, both in the standard test specimens and in the test specimens with LFS.  
From the study on the corrosion behavior through electrochemical techniques and the study of the symptoms produced in the accelerated corrosion process, it may be concluded that in mortars with the presence of mixed-in chlorides, the incorporation of LFS in the mortar at the time of kneading does not negatively affect the corrosive process of the rebar.  
M.I.P.: experimental tests, formal analysis, investigation, and writing--original draft preparation; A.C.: conceptualization, methodology, project administration, supervision, and discussion of the results; A.R.: resources, validation, and writing--review; M.d.l.N.G.: methodology, investigation, and writing--review and editing.  
This research received no external funding.  
The authors declare no conflict of interest.
# A Study on Design Requirement Development and Satisfaction for Future Virtual World Systems
## 5 Discussion  
### Architecture Comparison  
In this section, we compare the virtual world architectures in requirement satisfaction. The introduced architecture classes include C/S, P2P, Hybrid-I, and Hybrid-II, and Virtual Net. In the discussion, they are further classified as centralized architectures (C/S and Hybrid-I) and the decentralized architectures (P2P and Hybrid-II). Table 2 shows the comparison results. Sufficiency can be satisfied with the separation of client and service. In centralized architectures, since most computational complex tasks are moved to the service end, including simulation logic, physics computation, and graphics computation, a lightweight client only needs to render the results generated from servers. In contrast, decentralized architectures require client devices to play the role of both server and client, imposing large computation loads on them. A lightweight client device may not have the capability to render a highly immersive environment. Moreover, compared to the rest architectures, P2P virtual worlds may suffer from heterogeneous peer resources. Some peers may be located on low-performance or unreliable devices, which will provide fewer services to other peers and even slow down the entire system. Reliability can be satisfied with replication and synchronization. In centralized architectures, each state update will be synchronized from client to server. Since the centralized architectures preserve a copy of the user state at the server end, they can tolerate client failure. A recovered client can catch up with the latest state by retrieving the data from the server. Moreover, the database synchronization approaches can maintain replica consistency between replicated databases. However, centralized architectures only maintain a connection between a client and a server, which does not tolerate connection failure. The decentralized architectures also provide replication for backing up the client state. Thus, the client state can be recovered after client failure. However, they neither provide replica consistency guarantee nor tolerate connection failure. Content persistency can be satisfied with decentralization. The centralized architectures contain a central entity for rewarding user content, creating a single point of failure. As shown above, even if advanced fault tolerance techniques can minimize the failure of a system, the failure of the control entity will cause services to discontinue. Decentralized architectures, on the other hand, are immune from system-level failure, since such a system is not controlled by a single entity. Moreover, the underlying
## Appendix A  
The following content in Appendix A is the supplemental descriptions in the Section 2 on how to control the quality of RO profiles.  
1. The 9-point moving average proceeds to an electronic density (Ne) series from the bottom to the top height of the designated RO profile. After that, the average deviation between the Ne of each point and its initial value is  
\[AD=\frac{\sum\limits_{i=1}^{N}\left(\left|\left(Ne_{i}-\overline{Ne_{i}}\right) /\overline{Ne_{i}}\right|\right)}{N}<0.25 \tag{1}\]  
where \(Ne_{i}\) and \(\overline{Ne_{i}}\) are the observation and 9-point moving average of the electron density at point \(i\) above 110 km, and \(N\) is the sampling number per profile. For AD > 0.25, the unqualified profile is considered to be at a high-noise level [56].  
2. The hmF2 exists at a 150-450 km height:  
\[150\ km<hmF2<450\ km \tag{2}\]  
3. In the RO dataset, there are also profiles without obvious Nmf2 and hmf2, which is unreasonable and needs to be removed. For the quality control, two slopes (slope1 and slope2) at a height of 150-450 km are defined and should be satisfied as  
\[\left\{\begin{array}{c}\text{Slope }l=\frac{Ne(h_{1})-Nm/2}{h_{1}-hmf2}<0\\ \text{Slope }2=\frac{Ne(h_{2})-Nm/2}{h_{2}-hmf2}<0.1\ el\ cm^{-4}\end{array}\right. \tag{3}\]  
where \(h_{1}\) (\(\sim\)450 km usually) and \(h_{2}\) (\(\sim\)150 km usually) represent the top and the lowest height at each profile, respectively, and the \(Ne\) (\(h_{1}\)) and \(Ne\) (\(h_{2}\)) are the electron densities at the height of \(h_{1}\) and \(h_{2}\), respectively. Here, the maximum electron density at the height150-450 km defaults to the Nmf2 with a corresponding hmF2 as a maximum height in the F2 layer.  
4. Except for meeting the conditions of (A1)-(A3), the difference between longitudes and latitudes at the heights of 100 and 500 km should be less than \(5^{\circ}\), and if not, it must be filtered. The condition (A4) is expressed as  
\[\left\{\begin{array}{l}|\text{Lon}_{100\text{ km}}-\text{Lon}_{500\text{ km}}|<5^{\circ}\\ |\text{Lat}_{100\text{ km}}-\text{ Lat}_{500\text{ km}}|<5^{\circ}\end{array}\right.\] (A4)
## 3 Results
### Equation Fitting of Ammonia Volatilization Fluxes
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**pH**} & **Temperature** & \multicolumn{2}{c}{**SAB**} & \multirow{2}{*}{**pH**} & **Temperature** & \multicolumn{2}{c}{**SDP**} \\  & **(\({}^{\circ}\)C)** & & & & & (\({}^{\circ}\)C) & \(a\) & \(b\) & \(R^{2}\) \\ \hline \multirow{4}{*}{7.0} & 15 & 0.0030 & 0.0915 & 0.9214 & & 15 & 0.0012 & 0.0433 & 0.8932 \\  & 20 & 0.0046 & 0.0913 & 0.9664 & & 20 & 0.0026 & 0.0591 & 0.9314 \\  & 25 & 0.0070 & 0.1118 & 0.9727 & & 25 & 0.0044 & 0.0477 & 0.9877 \\  & 30 & 0.0098 & 0.1735 & 0.9513 & & 30 & 0.0071 & 0.1393 & 0.9549 \\ \hline \multirow{4}{*}{7.5} & 15 & 0.0074 & 0.1510 & 0.9651 & & 15 & 0.0050 & 0.0623 & 0.9363 \\  & 20 & 0.0114 & 0.1870 & 0.9718 & & 20 & 0.0099 & 0.0843 & 0.9759 \\  & 25 & 0.0190 & 0.2138 & 0.9779 & & 25 & 0.0143 & 0.1801 & 0.9668 \\  & 30 & 0.0268 & 0.3183 & 0.9839 & & 30 & 0.0294 & 0.2273 & 0.9659 \\ \hline \multirow{4}{*}{8.0} & 15 & 0.0235 & 0.1931 & 0.9456 & & 15 & 0.0114 & 0.1539 & 0.9527 \\  & 20 & 0.0397 & 0.2949 & 0.9650 & & 20 & 0.0202 & 0.2471 & 0.9650 \\  & 25 & 0.0606 & 0.4168 & 0.9789 & & 25 & 0.0354 & 0.3770 & 0.9712 \\  & 30 & 0.0990 & 0.4854 & 0.9869 & & 30 & 0.0749 & 0.4938 & 0.9861 \\ \hline \multirow{4}{*}{8.5} & 15 & 0.0836 & 0.2014 & 0.9537 & & 15 & 0.0483 & 0.2405 & 0.9495 \\  & 20 & 0.1251 & 0.3148 & 0.9602 & & 20 & 0.0897 & 0.3491 & 0.9799 \\ \cline{1-1}  & 25 & 0.1675 & 0.6422 & 0.9863 & & 25 & 0.1274 & 0.4277 & 0.9904 \\ \cline{1-1}  & 30 & 0.2434 & 0.7535 & 0.9897 & & 30 & 0.2103 & 0.6705 & 0.9756 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The regression coefficients between ammonia volatilization fluxes and ammonia concentration (SAB and SDP). There were differences between the coefficient of determination (\(R^{2}\)) values of the two, which shows a little variability between volatilization fluxes and concentration.
# Transmission Performance Analysis of RV Reducers Influenced by Profile Modification and Load
## 2 Analytical Model of RV Reducer with Tooth Profile Modifications
### Transmission Efficiency  
Because an RV reducer is a type of precision drive, the loss of the rotation angle is extremely small. The rotation angle loss can then be neglected, and only the torque loss owing to the friction torque is used to calculate the transmission efficiency. Because the friction loss of a bearing and load independent power loss is not the scope of the present study, it is not considered herein [28]. Therefore, the efficiency of the RV reducer is defined as follows:  
\[\eta_{c}=1-\frac{T_{f}}{T_{o}}, \tag{30}\]  
where \(T_{f}\) is the friction torque of the cycloid gears, which can be calculated as follows:  
\[T_{f}=2\sum_{i=m_{1}}^{m_{2}}\left(F_{fi}^{x}y_{pi}^{\prime}+F_{fi}^{y}x_{pi}^{ \prime}\right) \tag{31}\]
## 2 Image Simulation in Remote Sensing  
[PERSON] and [PERSON] [2] fused a panchromatic image with a SAR image to improve object recognition. By learning each class independently, the improved results were compared to existing methods. This method was designed to provide a geospatial information base without a loss of information while considering differences in the image mechanism of the two images.  
[PERSON] and coauthors [3], in their paper, investigated kinematic in situ self-calibration to frequently re-calibrate a backpack-based MBL (Multi-Beam LiDAR) system using on-site data for handling unstable measurements of a sensor. Frequent in situ calibration prior to MBL data acquisition is an essential step in order to meet accuracy-level requirements and to implement these scanners for precise mobile applications. A simulator program was first utilized to generate simulation datasets with various observation settings, network configurations, test sites, and targets. Afterwards, self-calibration was carried out using the simulation datasets.  
The high operational cost of aerial images makes it difficult to acquire periodic observations of a region of interest. Satellite imagery is an alternative for this problem and, in their article, [PERSON] and coworkers [4] propose a context-based approach to simulate the 10 m resolution of Sentinel-2 imagery to produce 2.5 and 5.0 m prediction images using an aerial orthoinage. This can be considered as an alternative to providing high-resolution images in a cost-effective way in the field of remote sensing  
A rotational shearing interferometer has been proposed for the direct detection of extra-solar planets. This technique consists of the non-total cancellation of star radiation in order to improve signal magnitude. [PERSON] and coauthors [5] propose a novel method to enhance signal magnitude by means of a star-planet interference, as well as the use of interferograms that are computationally simulated to confirm the viability of the technique.  
Despite advances in SAR image processing, existing detection technologies still have limitations in boosting detection performance because of their inherently noisy characteristics. [PERSON] and collaborators [6], in their contribution, propose a novel object detection framework that combines an unsupervised denoising network and a traditional detection network to leverage a strategy for fusing region proposals extracted from both raw SAR images and synthetically denoised SAR images.  
[PERSON] and [PERSON] [7], in their paper, propose sensor level mosaicking to generate a seamless image product with geometric accuracy to meet mapping requirements. The proposed method successfully identifies and removes irregular image discrepancies between adjacent data.  
We would like to thank all the authors who contributed to the valuable research results and the reviewers who provided professional advice to ensure that a high-quality paper was published. Additionally, we place on record our gratitude to the editorial team of _Applied Sciences_.  
The authors declare no conflict of interest.