esa-sceva/satcom-chunk-collection huggingface dataset:
# Human Exposure to Toxic Metals (Cd, Pb, Hg) and Nitrates (NO3-) from Seaweed Consumption  
[PERSON]  
1 Public Health Laboratory of Las Palmas (Laboratorio de Salud Publika), Canary Health Service (Servicio Canario de Salud), 35004 Las Palmas de Gran Canaria, Spain;  
[EMAIL_ADDRESS] (V.M.-L.); [EMAIL_ADDRESS] (M.N.-R.)  
2 Department of Toxicology, Universidad de La Laguna, 38200 La Laguna, Spain;  
[EMAIL_ADDRESS] (P.A.D.); alju@[EMAIL_ADDRESS] (J.J.P.);  
[EMAIL_ADDRESS] (G.M.); [EMAIL_ADDRESS] (A.J.G.);  
[EMAIL_ADDRESS] (C.R.-A)  
3 Dipartimento di Scienze (DSU), University of Basilicata, 85100 Potenza, Italy  
4 Scuola di Scienze del Farmaoco dei Prodotti della Salute, Universita di Camerino, 62032 Camerino, Italy;  
[EMAIL_ADDRESS]  
4 Correspondence: [EMAIL_ADDRESS]; Tel.: +34-634-541-612  
[PERSON]  
2 Department of Toxicology, Universidad de La Laguna, 38200 La Laguna, Spain;  
[EMAIL_ADDRESS] (P.A.D.); alju@[EMAIL_ADDRESS] (J.P.);  
[EMAIL_ADDRESS] (G.M.); [EMAIL_ADDRESS] (A.J.G.);  
[EMAIL_ADDRESS] (C.R.-A)  
3 Dipartimento di Scienze (DSU), University of Basilicata, 85100 Potenza, Italy  
3 Scuola di Scienze del Farmaoco dei Prodotti della Salute, Universita di Camerino, 62032 Camerino, Italy;  
[EMAIL_ADDRESS]  
4 Correspondence: [EMAIL_ADDRESS]; Tel.: +34-634-541-612  
[PERSON]  
2 Department of Toxicology, Universidad de La Laguna, 38200 La Laguna, Spain;  
[EMAIL_ADDRESS] (P.A.D.); [EMAIL_ADDRESS] (J.P.);  
[EMAIL_ADDRESS] (G.M.); [EMAIL_ADDRESS] (A.J.G.);  
[EMAIL_ADDRESS] (C.R.-A)  
3 Dipartimento di Scienze (DSU), University of Basilicata, 85100 Potenza, Italy  
3 Scuola di Scienze del Farmaoco dei Prodotti della Salute, Universita di Camerino, 62032 Camerino, Italy;  
[EMAIL_ADDRESS]  
4 Correspondence: [EMAIL_ADDRESS]; Tel.: +34-634-541-612  
Searweed is now considered a functional food with a high nutritional value in Western countries, and the consumption of different species of edible algae has grown exponentially in recent decades. However, anthropogenic pressure on the seas has increased the presence of pollutants such as toxic metals and nitrates that can accumulate in algae. It is necessary to know the levels of these contaminants and the dietary exposure from the consumption of edible algae. The content of toxic metals (Cd, Pb, Hg) and nitrates (NO3-) was determined in 72 samples of edible algae marketed in the Canary Islands (Spain). Cd stands out in the Asian algae hijiki (1.196 mg/kg) and nori (1.005 mg/kg). Pb stands out in the Asian wakame seaweed (0.119 mg/kg). The highest mean concentration of Hg was in European name algae (0.055 mg/kg). Some samples of the nori seaweed had NO3- concentrations of >8000 mg/kg. Considering the consumption recommended by the manufacturer of 4 g/day, the maximum admissible intake values are not exceeded, and, consequently, this does not pose a risk to health. However, in the case of Cd, Pb, Hg, and NO3-, legislation is necessary to regulate their content in edible algae.  
seaweeds; cadmium; lead; mercury; nitrates; dietary intake; risk assessment
# A Visualization Tool for Flood Dynamics Monitoring Using a Graph-Based Approach
## 1 Introduction  
The emergence of several new Synthetic Aperture Radar (SAR) missions throughout the past decade has boosted the field of flood remote sensing. However, most studies focus on the development of new or improved flood mapping algorithms, which result in single date flood extents. These products fail to provide information on flood dynamics, which is crucial for several applications. For example, flood duration can be linked directly to the degree of economic losses and damages to structures [1; 2; 3; 4] in the context of disaster impact assessment (emergency relief, damage assessment, insurance claims...). Moreover, data assimilation for hydrodynamic forecasting could be improved by preserving information-dense regions, while removing redundant points [5; 6; 7; 8]. In this way it is possible to determine where, when, and how often remote sensing data should be acquired for flood extent assimilation to be most effective. [6]. With this research we aim at producing a unified flood map, not limited to just flood extent, but incorporating insights on dynamics.  
In [9], a visualization/analysis framework was established for flood dynamics, combining objects and graphs. This approach was based on the research of [10; 11]. In this letter, we have extended our previous work to cover larger areas. This allows for a new way of visualizing flood dynamics. In order to test the behavior of the workflow proposed in [9] at a larger scale, two floods were chosen whichextent over larger areas. These two non-similar floods were chosen because of their different origin and evolution.
## 5 Further Discussion  
The results of this study showed that citric acid undergoes alterations of its chemical structure rather easily by a mild thermal treatment or even at room temperature. Since the esterification reaction is a two-direction reaction and can be reversed, the extent of esterification depends on temperature, available water, air humidity, etc. Thus, citric acid can undergo different alterations of its structure depending on its storage conditions, subjected treatment, etc. The provided insights could assist in improving the performance and quality of food or drug formulations that involve the use of citric acid. More precisely, based on the results of this study, it is clear that citric acid does not always exhibit the very same properties, which seem to depend on the subjected treatment as well as its storage conditions. For achieving the optimum design of a food or drug formulation, it is necessary to use the proper amounts of additives such as preservatives, antioxidants, etc.; that is, there should not be an amount of additive higher than the one needed, and on the other hand, the amount of the additive should be sufficient in order to be active and adequate to fulfill its purpose of use. The alteration of the chemical structure of citric acid obviously affects its properties either directly or indirectly. An example of direct influence, as shown in this study, is the alteration of its antioxidant activity, which can be related to the ability for chelation capacity. The alteration of the chemical structure due to various treatment or storage conditions affects the pH of citric acid and thus can also affect, indirectly, its preservative activity, which is related to its pH value. Similarly, citric acid is used to improve the solubility/release of drugs that are poorly soluble in water. The alteration of the structure and the reduction of OH and COOH groups can also affect the solubility and hydrophilicity of citric acid. All in all, different batches of citric acid may exhibit different chemical structures and thus different properties. Thus, such issues should be taken into account in order to achieve the optimum performance/quality of a product.  
\begin{table}
\begin{tabular}{c c} \hline
**Product** & \(\Delta\)**G of Reaction, kJ/mol** \\ \hline E33 dim & +1.6 \\ \hline A13 & +13.9 \\ \hline A15 & +29.1 \\ \hline A13 dim & +42.9 \\ \hline E13 & +44.5 \\ \hline A11 dim & +46.1 \\ \hline A33 dim & +57.3 \\ \hline E13 dim & +58.5 \\ \hline E33 & +115.2 \\ \hline \end{tabular}
\end{table}
Table 3: \(\Delta\)G of the nine possible decomposition reactions of citric acid (formation of ester or anhydride) as calculated from DFT.
## 3 Discussion
### Difficulties of Spare Parts Management  
The fourth question (RQ4) examined in this research relates to 'the difficulties faced in spare parts management'. The review shows that spare parts are usually faced with uncertainties in terms of demand. Sometimes, material supply capability is constrained by a specific type of AM technology; therefore, its management can be different. Spare parts demand is affected by stochastic factors such as wear behaviour, the type of maintenance adopted, and failure rates [27]. One needs to know that the parts fail not only because of their own wear and tear but also because of the problem with the integrated parts. Any part failure results in downtime, which can be costly for the industry. Therefore, safety stocks are still maintained, albeit at a lower level, so that the service level can be increased. As studies showed, AM-based spare parts are usually for a short-term gap, and the trade-off between the spares and raw materials also needs to be assessed. It should be noted that some spare parts can take months or even a year, especially if it is a rare component or requires a special raw material for production [9]. Some spares can even be very costly, and some others can be so large in size that they require specific AM technology. However, in high-value businesses, the cost of spares can be a secondary issue, as the loss due to downtime could be much larger [9]. SC management challenges are faced in aircraft spare parts owing to the variability of aircraft locations. This provides challenges in terms of locating AM facilities and investing in SC management [27].
## 3 Results and Discussion
### (E)-2-nonenal as an Oxidation Marker  
It is possible that monitoring the degradation progress of EVOO over time could be broadly evaluated measuring (E)-2-nonenal levels. Further, (E)-2-nonenal was found at trace levels in EVOO, and the lipoxygenase cascade--the main biochemical pathway--promotes the formation of C6 volatile compounds from linoleic and linoleic hydroperoxides, rather than the C9 compounds [47].  
Thus, (E)-2-nonenal was chosen as a predictor of oxidation. For this purpose, a polynomial fit to the (E)-2-nonenal dataset as a function of time was performed for each storage condition. That is, a linear regression fitted to the dataset was performed, finding significant correlations for conditions C4 (\(p<0.03\)) and C5 (\(p<0.00\)), obtaining the following equations:  
\[\text{C4 Condition, ($E$)-2-nonenal (mg/kg) = 0.128 (month) + 0.5105 (R^2 = 0.8005)} \tag{1}\]  
\[\text{C5 Condition, ($E$)-2-nonenal (mg/ kg) = 0.797 (month) - 0.6482 (R^2 = 0.9861)} \tag{2}\]  
Previously, it was determined that both hexanal and nonenal are good oxidation indicators for sunflower and palm oils, yielding a good linear relationship with TOTOX [42]. Furthermore, other studies identified the nonanal compound as an early oxidative marker for extra virgin olive oil [47].  
Considering that EVOO has an odor threshold for (E)-2-nonenal of 0.9 mg/kg, an oil stored at 30 \({}^{\circ}\)C in the dark would reach this odor threshold after 3 months of storage, and if stored at 40 \({}^{\circ}\)C in the dark the odor threshold would be reached after just 1.94 months  
Figure 5: Regression vector of the PLS model for relation between oils variables and (E)-2-nonenal.  
(58 days) of storage. Therefore, under the above conditions a consumer could perceive a fatty or rancid aroma in the oil, indicating an off-flavor, and the oil would lose its extra virgin category [2].
# Multilayer Model in Soil Moisture Content Retrieval Using GNSS Interferometric Reflectometry
## 3 Simulation Analysis
### Added Noise
As shown in Figure 11, spectral graphs of two different modes under different soil moisture changes are drawn in this study. Similar to Figure 6, the spectrum of the two modes and the simulation results without noise show the same trends.
## 1 Introduction  
Since the 1990s, the market for solar heat-supply systems (SHSSs) has grown tremendously in the world. In particular, the Chinese SHSS market has become the largest of them. The annual output increased to 13 million square meters in 2004 from 0.5 million square meters in 1991, with an average annual growth rate of over 28.5%. There are basically three most common types of collectors: vacuum tube collectors (heat-pipe vacuum tube collectors), flat-plate collectors, and combination collectors [1]. Today, combined solar collectors are attracting more and more attention from researchers, as they make it possible to use the advantages of some and eliminate the disadvantages of other technical solutions [2]; hybrid systems, which are relevant in times of decarbonization and increasing eco-technologies, are also receiving increased attention [3]. A particularly promising direction in the development of solar energy solutions is the combination of solar collector elements and the external protection of buildings, in particular, walls [4].  
A variety of solar panels have been designed and researched over the past few decades [5]. The main goal of these studies was to increase the efficiency of solar panels [6,7] and reduce their cost since an increase in efficiency is mainly accompanied by an increase in the price of solar panels. Therefore, it is advisable to search for the optimal parameters of the solar panel, which will make it possible to obtain maximum efficiency at minimum economic costs.  
The improvement in existing solar heat supply (SHS) systems [8,9] for their maximum integration into traditional heat-supply systems and wide application in practice is relevant today. One of the ways to solve this aspect is to use the effect of combining solar panels with the roof of a house [10]. At the same time, the issue of increasing their efficiency from the point of view of choosing the optimal design parameters (covering material, tubes, etc.)and their quantitative characteristics (diameter, distance between tubes, location, etc.) is important to consider. Known combined solar heaters do not provide the most efficient use of solar energy with a relatively low cost.  
Currently, there are a significant number of installations that use solar energy as well as circuit solutions of solar heat-supply systems with such elements [11; 12]. Several designs of solar installations have been developed [13; 14], but each of them works most efficiently only in certain conditions. Therefore, an analysis of the known methods of increasing the efficiency of such installations and solar heat-supply systems [15; 16] as a whole is necessary for the selection of their rational schematic solutions. It is also important to study not only each element separately [17; 18] but also the entire system together in order to obtain the maximum possible information on improving the efficiency of this system.
# Frequency Comb-Based WDM Transmission Systems Enabling Joint Signal Processing
## 2 Comb-Based Superchannels
### Superchannel Transmitter Requirements
#### 2.1.2 Guard Bands  
While the bandwidth of electronics is increasing rapidly, several Tb/s line rates are not feasible using a single wavelength channel, and thus, multiplexing is required [81]. In such scenarios, dense packing is required to avoid the loss of spectral efficiency due to inter-channel guard bands [75]. This is a promising use case for frequency combs as the phase-locked carriers avoid channel drifts and allow for dense packing beyond what can be achieved using free-running lasers. This can be fully utilized in coherent superchannels, since the subchannels are routed together, and no guard bands are needed to account for the limited granularity of wavelength demultiplexers.  
The advantage of combs can be seen by considering a required guard band of 1 GHz in the case of free-running lasers. For a 100-Gbaud channel, this results in 1% loss of spectral efficiency. Considering slicing this channel into 10 subcarriers using free-running lasers, the equivalent guard-band penalty is then 10% of the channel width. However, if frequency combs are employed, the required guard bands can be as low as 100 MHz [82], again resulting in an equivalent guard-band penalty of 1% of the channel width. Thus, a comb-based superchannel using 100 \(\times\) 10 Gbaud channels and a system using free-running lasers and 10 \(\times\) 100 Gbaud have an equivalent guard-band overhead. This can be exploited to ease the requirements for very high spectral efficiency transmission as the effective number of bits (ENOBs) usually is highly limited at high symbol rates [81]. At the expense of employing additional transmitters, combs can therefore enable higher spectral efficiency by simply allowing for forming a superchannel containing more lower-symbol rate channels.
## 2 Materials and Methods
### System Communication  
The six core components are interconnected modules that communicate with each other and with external elements using different interfaces and standards (see Figure 2).  
The cloud backend is a pivotal component of the V-Cockpit system, responsible for data management and processing. The backend infrastructure is built on scalable cloud services, providing robust storage and computational capabilities. REST APIs are used for seamless communication between the VR client (2), third-party plugins (1), dashboard (6), and the cloud backend (4). The system supports the structuring of different activities into projects with various user types to handle administrative roles, design tasks, and to manage customer testing, with access to backend services granted through user logins and JWT authorization. This approach ensures secure and controlled interactions tailored to the specific roles and responsibilities of each user.  
Data synchronization between the VR client (2) and cloud backend (4) ensures that all components are up to date with the latest changes. This synchronization is crucial for collaborative design processes, where multiple stakeholders might be working on the same project simultaneously. Immediate feedback and iteration enhance the overall efficiency of the design process.  
A communication layer (h), consisting of custom drivers and middleware, facilitates communication between the VR client (2) and both physical (b) and emulated (a) hardware. This layer ensures that inputs from physical controls are accurately reflected in the virtual environment and vice versa. Custom-developed hardware boards (3) convert automotive FPD-Link III video streams, generated by the embedded board (b) running the native IVI software, to HDMI signals which are captured by frame grabbers (f) and transferred to the VR client (2). Interaction with the embedded board is supported over Ethernet or CAN Bus (g), depending on the target embedded system. This bidirectional communication is essential for creating a realistic and interactive user experience. In the case of emulated  
Figure 2: System components communication.  
hardware (a), the communication layer also supports video streaming (c) and manages event streams (d) to enable interaction.  
External sensors (e) play a crucial role in supporting analytics. Devices such as Bitalino use Bluetooth to transmit physiological signals to the VR client during simulations. Additionally, if available, gaze sensors embedded in VR headsets like the HTC Vive Eye Pro or Meta Quest Pro are supported, providing precise tracking of the gaze (user's eye movements) to further enrich analytics.
# Enhancing PAPR and Throughput for DFT-s-OFDM System Using FTN and IOTA Filtering
## 2 Signal Model and Performance Metrics
### Performance Metrics
#### 2.2.1 Peak-to-Average Power Ratio  
Denote \(x(n)\) as the transmit signal. The performance metric PAPR is defined as the ratio of the peak value to the average value of \(x(n)\), which is given by  
\[\text{PAPR}=\frac{\max\lvert x(n)\rvert^{2}}{\text{mean}\,\lvert x(n)\rvert^{2}}. \tag{2}\]  
Due to the limited dynamic range of the power amplifier in high frequency transmission, the signal with high PAPR suffers from non-linear distortion. Therefore, PAPR is a key indicator of the power efficiency of the multi-carrier system.  
The OFDM signal is composed of multiple independently modulated sub-carrier signals. When the phases of the sub-carriers are the same or similar, the superimposed signal will be modulated by the same initial phase signal, resulting in a larger instantaneous power peak value, which further causes a high PAPR. Due to the high PAPR, the OFDM signal can easily reach the boundary of the dynamic range of a power amplifier [26]. This can cause unexpected distortion, especially in high frequency transmissions, and may even cause inter-carrier interference due to the leakage. This has hindered the application of OFDM-like waveforms in mmWave and THz communication systems [27; 28].
## 2 Materials and Methods  
Ba\({}_{1-x}\)Ca\({}_{x}\)Ti\({}_{0.9}\)Zr\({}_{0.1}\)O\({}_{3}\) solid solutions (\(x\) = 0.10, 0.15, 0.18) were prepared by conventional solid state method. BaCO\({}_{3}\) (99.0%, Analytyca, Monterrey, Mexico), CaCO\({}_{3}\) (99.0%, Fluka, Seelze, Germany), TiO\({}_{2}\) (99.0%, Aldrich, St. Louis, MO, USA) and ZrO\({}_{2}\) (99.0%, Riedel-deHaen, Seelze, Germany) were used as starting materials. Reagents were dried at 200 \({}^{\circ}\)C for 2 h, weighted according to the stoichiometry ratio and mixed for 30 min in an agate mortar using acetone. Afterwards, the mixture was calcined at 1250 \({}^{\circ}\)C for 2 h, followed by a ball-milling process (product ground by zirconia balls using ethanol as grinding media for 24 h). Finally, powders were uniaxially pressed into pellets (\(\sim\)13.0 mm diameter; \(\sim\)1.5 mm thickness, 40 MPa) and sintered at 1400 \({}^{\circ}\)C for 2 h in air.  
Phase structure of BCTZ ceramics was identified using X-ray diffraction (D-8 Advance, Bruker Co., Billerica, MA, USA) with Cu K\(\alpha\) radiation, 0.016\({}^{\circ}\) step size (20) and 1 s of integration time. The microstructure of samples was analyzed by field emission scanning electron microscope (JSM-7600F, JEOL, Peabody, MA, USA). The EDS spectra were recorded with an INCA X-ray microanalysis system (EDX, Oxford Instruments plc., Oxfordshire, UK). Average grain size of a large sample area was determined using a computer-aided image analysis (Image) software, National Institutes of Health (NIH), Bethesda, MD, USA).  
To measure electrical properties, sintered samples were polished and coated on both sides with gold tincture and fired at 700 \({}^{\circ}\)C for 30 min to form electrodes.  
Temperature-dependent dielectric permittivity and losses were performed with a precision impedance analyzer Agilent 4294A (Keysight Tech. Inc., Santa Rosa, CA, USA). Complex impedance measures were achieved with an impedance gain/phase analyzer SI 1260 (Solartron Analytical, Hampshire, UK) connected to a dielectric interface 1296 (Solartron Analytical). Experiments were completed using a computer-controlled temperature furnace 47760 (Thermo Fisher Scientific Inc., Waltham, MA, USA) evaluating from 30 \({}^{\circ}\)C to 700 \({}^{\circ}\)C. The impedance fitting analysis was performed using ZView software (ver. 3.2c Scribner Associates, Inc., Southern Pines, NC, USA).