esa-sceva/satcom-chunk-collection huggingface dataset:
## 6 Results and Discussion
### HPN with CBS Architecture  
In this paper, the HPN is depicted as a massive MIMO equipped with a 128-antenna array. In this paradigm, the base station transmits at 46 dBm. The received power results are presented in Figure 10, showcasing that in the massive MIMO scenario, very high-power levels are reported compared to the DBS network. This is a consequence of the  
Figure 9: The simulation area (RoI), 3D model of street canyon.  
substantial number of antennas in the massive MIMO base station in contrast to the UE. The increased antenna gain effectively compensates for the high path loss at mmWave frequencies, resulting in a notable reduction in the exhibited path loss, as illustrated in Figure 11. This enhancement in gain achieved by the massive number of antennas in the HPN significantly contributes to the successful mitigation of challenges posed by mmWave propagation and ensures robust network performance.  
However, the use of massive MIMO has significantly increased the power density in the vicinity of the base station transmitter. As a result, high figures for MPE levels are reported, particularly for users located within the radiation area. These users may experience elevated temperature increases in their eyes and skin tissues due to exposure to mmWave NIR.  
Figure 12 illustrates the power density measured in W/m\({}^{2}\) received by UEs in relation to the hazard threshold according to the regulations of the IEEE and the ICNIRP. The findings show that UEs in close proximity to the massive MIMO array may be exposed to mmWave NIR, potentially leading to heat increases in their body tissues, particularly in the area below 200 m. This area (<200m) where the power density (blue line) crosses the safety standards (red line) can pose a significant hazard to living beings and needs to be addressed. Prolonged exposure to NIR in these areas can lead to even worse diseases such as tissue damage and other related consequences.  
It is important to emphasize that these radiation exposure results are based on the assumption of stationary transmitters and receivers. In scenarios where users are moving at higher speeds, lower figures of exposure are expected due to the dynamic nature of the wireless communication system. Nevertheless, this study highlights the need for careful consideration of power density levels in close proximity to massive MIMO arrays operating at a high frequency to ensure compliance with safety standards and mitigate potential health risks for users.  
Figure 10: Received power (dBm) for mMIMO and DBS. Where colors represent different signals from the massive MIMO array.
# New Insight on the Formation of 2-Aminoacetophenone in White Wines
## 2 Materials and Methods
### Experiments Using Antioxidants and Transition Metal Ions Supplementation  
#### 2.2.1 Antioxidants Addition  
Two studies investigating the effect of antioxidants on 2-AAP formation were carried out in two white wines (A and B). Both wines were initially spiked with 100 \(\mu\)g/L of 3-IAA in order to ensure 2-AAP production. Chemical parameters of wines A and B are displayed in Supplementary Data S2.  
Experiment 1 was performed in 2021 on a 2020 white blend from Slovenia (wine B). Initial free sulfite and 2-AAP concentrations were 25 mg/L and 0.75 \(\mu\)g/L, respectively. A series of different antioxidants was tested as follows: glutathione (GSH) at 12 mg/L, inactivated yeast derivatives (IYD) at 400 mg/L, gallic acid (GA) at 70 mg/L, commercial ellagitannins (TA1) at 100 mg/L, commercial mixture of ellagitannins and condensed tannins (TA2) at 100 mg/L and inactivated yeast derivatives (400 mg/L) in combination with commercial ellagitannins (100 mg/L). The targeted values of antioxidant additions were set according to supplier recommendations.  
Experiment 2 was performed in 2022 on wine A again. Initial concentrations of free sulfite, 2-AAP, Cu, Mn and Fe were 22 mg/L, 0.35 \(\mu\)g/L, 75 \(\mu\)g/L, 796 \(\mu\)g/L and 1047 \(\mu\)g/L, respectively. A series of different antioxidants were tested as follows: GSH at 12 mg/L, inactivated yeast derivatives (IYD) at 400 mg/L, commercial ellagitannin (TA1) at 10 mg/L and 100 mg/L and inactivated yeast derivatives (400 mg/L) in combination with commercial ellagitannin (100 mg/L). Each antioxidant treatment was tested alone and in combination with a mixture of metal ions to reach the final concentration as follows: Cu (II) at 1 mg/L using copper (II) sulfate pentahydrate solution; Fe(II)/Fe(III) (1:1) at 5 mg/L using iron (II) sulfate heptahydrate and iron (III) chloride hexahydrate solutions; and Mn (II) at 4 mg/L using manganese (II) sulfate monohydrate solution.  
Each treatment was prepared in triplicate adding the antioxidant and metal ion solutions in 20 mL vials filled with 18 mL of wine and tightly sealed with PTFE-lined caps. Vials were then exposed to artificial ageing in the oven for 4 days at 40 \({}^{\circ}\)C. Thereafter, vials were stored in the fridge for a few days prior to analysis.
# A Review of Pedestrian Indoor Positioning Systems for Mass Market Applications
###### Abstract  
In the last decade, the interest in Indoor Location Based Services (ILBS) has increased stimulating the development of Indoor Positioning Systems (IPS). In particular, ILBS look for positioning systems that can be applied anywhere in the world for millions of users, that is, there is a need for developing IPS for mass market applications. Those systems must provide accurate position estimations with minimum infrastructure cost and easy scalability to different environments. This survey overviews the current state of the art of IPSs and classifies them in terms of the infrastructure and methodology employed. Finally, each group is reviewed analysing its advantages and disadvantages and its applicability to mass market applications.  
Keywords: indoor localization; pedestrian tracking; navigation, indoor location based services +
Footnote †: journal: Sensors
## 4 Laser Scribing Machine and Parameters of Experiment
### Experiment Parameters  
The specification of the experiment plate with TC4 as base material is 300 mm \(\times\) 200 mm \(\times\) 2 mm, and its surface is covered with AC850 protective adhesive. According to the actual process requirements of laser scribing, the coating layer of laser scribing protective adhesive is 0.6 mm, which is uniform overall, and the color of AC850 protective adhesive is dark green. The scribing depth is measured by a super-high magnification lens zoom 3D microscope (Equipment model: Olympus dsk1000). The experiment plate is placed horizontally on the C-axis turntable, and the incident angle of the laser is changed by controlling the A/B rotation axis to complete the experimental processing. The test parameters of laser scribing is shown in Table 2.  
The output of the CO\({}_{2}\) laser is controlled by the Siemens SIMATIC S7-1200 module by using a PWM pulse signal. In order to accurately measure the influence of laser power  
\begin{table}
\begin{tabular}{c c c} \hline
**Num** & **Quantitative Parameters** & **Variable Parameters** \\ \hline  & Velocity: 200 mm/min; & \\
1 & Frequency: 1000 Hz; & Duty ratios (\%): 3, 7, 9, 11, 13, 15, 20 \\  & Incident angles: 0\({}^{\circ}\). & \\  & Duty ratios: 9\%; & \\
2 & Frequency: 1000 Hz. & \\  & Incident angles: 0\({}^{\circ}\) & 800, 900, 1000, 1200, 1500, 1800, 2400. \\  & Duty ratios: 9\%; & \\
3 & Velocity: 1200 mm/min; & Frequency (Hz): \\  & Incident angles: 0\({}^{\circ}\) & 1000, 2000, 4000, 6000, 10,000. \\  & Duty ratios: 9\%; & \\
4 & Velocity: 1200 mm/min; & Forward angle (\({}^{\circ}\)): \(-36\), \(-30\), \(-24\), \(-18\), \(-12\), \\  & Frequency: 1000 Hz. & \(-6\), 0, 6, 12, 18, 24, 30, 36. \\  & Duty ratios: 9\%; & \\
5 & Velocity: 1200 mm/min; & Side slope angle (\({}^{\circ}\)): 0, 7, 14, 21, 28, 35, 42. \\  & Frequency: 1000 Hz. & \\ \hline \end{tabular}
\end{table}
Table 2: Test parameters of laser scribing.  
on the scribing depth, the actual average power of different duty cycles is measured at the pulse frequency of 1000 Hz, as shown in Table 3.  
Under the condition of a 9% duty cycle, the actual average power corresponding to different pulse frequencies is measured, as shown in Table 4. The minimum pulse time of the PWM module output is 1 \(\upmu\)s. The different laser power at different frequencies is mainly due to the time constant of the PWM wave, which has a great influence on the duty cycle at different frequencies.
# Blockage Effects in Wind Tunnel Tests for Tall Buildings with Surrounding Buildings
## 5 Discussion on the Existing Definition of Blockage Ratio  
The existing calculation methods for the blockage ratio mainly include the projection blockage ratio and the section blockage ratio. The definition of the projection blockage ratio is shown in Equation (1). The section blockage ratio is defined as the ratio of the windward area of all models at the section where the target pressure model is located compared to the sectional area of the wind tunnel. Taking the medium model as an example, Table 5 shows the projection blockage ratio, section blockage ratio, and relative error of the drag coefficient. Figure 19 shows the relative error of the drag coefficient varying with the blockage ratio.  
According to the results in Table 5 and Figure 19, the \(\Delta C_{D}\) does not increase uniformly with an increase of the projection blockage ratio and section blockage ratio. For example, the projection blockage ratio of test condition 1-3 was the same, while the \(\Delta C_{D}\) was not equal, which is a contradictory phenomenon. The same phenomenon occurred in test conditions 5-8. Similarly, the section blockage ratio of test conditions 1-3 was the same, but the \(\Delta C_{D}\) showed significant differences. Furthermore, the section blockage ratio of test condition 8 was smaller than that of test conditions 1 and 3, but the \(\Delta C_{D}\) was significantly larger than in those tests. The above results show that there will be contradictory phenomenon of a'same blockage ratio, different blockage effect' or a'small blockage ratio, large blockage effect' when the existing definitions of the blockage ratio are used to evaluate the blockage effect.  
Figure 19: \(\Delta C_{D}\) varying with blockage ratio. (**a**) \(\Delta C_{D}\) varying with projection blockage ratio; (**b**) \(\Delta C_{D}\) varying with section blockage ratio.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Test Condition** & **Projection Blockage Ratio** & **Section Blockage Ratio** & **Relative Error of Drag Coefficient (\(\Delta C_{D}\))** \\ \hline
1 & 4.76\% & 4.76\% & 19.7\% \\
2 & 4.76\% & 4.76\% & 21.2\% \\
3 & 4.76\% & 2.38\% & 18.2\% \\
4 & 4.76\% & 4.76\% & 15\% \\
5 & 7.14\% & 7.14\% & 23.5\% \\
6 & 7.14\% & 2.38\% & 16\% \\
7 & 7.14\% & 2.38\% & 14.4\% \\
8 & 7.14\% & 2.38\% & 24.5\% \\ \hline \end{tabular}
\end{table}
Table 5: The relative error of drag coefficient of the medium model.  
It can be seen from the above analysis that neither the projection blockage ratio nor the section blockage ratio can be used to directly evaluate the severity of the blockage effect. That is to say, the value of these two ratios does not correspond to the severity of the blockage effect of tall buildings with surrounding buildings.
## 3 Results and Discussion
### Characterization of the Membranes
#### 3.2.3 Surface Charge  
The zeta potential versus the pH of the reference and lignin-modified membranes are presented in Figure 4. As can be seen, the fabricated membranes possess generally a negatively charged surface over a wide pH range (3-8), which increases with a successive rise of pH. It can be seen clearly that membranes with less negative charge are attained as the dosage of lignin in the dope solution increases. The reduction of surface charge in the modified membrane compared to the virgin membrane can be  
Figure 3: The effect of different lignin dosages (wt %) on the optical properties of fabricated membranes; (**A**) L\({}^{*}\) (lightness/darkness), (**B**) a\({}^{*}\) (greenness/redness), (**C**) b\({}^{*}\) (blueness/yellowness), (**D**) ISO brightness (R457 C).  
explained by the fact that there are negatively and positively charged functional groups in the structure of lignin (phenolic, carboxyl, and methyl groups). Due to the interaction between lignin and the polyethersulfone polymer chain through hydrogen bonding, the available negatively charged group on the surface of the membrane can be reduced, and the zeta potential will thus decrease. In addition, it has been demonstrated in several studies that the lower absolute values of the zeta potential can stem from improvement in surface hydrophilicity [47; 48], which is also in accordance with the contact angle (i.e., hydrophilicity) of fabricated membranes. The negative surface charge of lignin can be induced significantly by increasing the pH through different functional groups present in the structure of lignin [49; 50]. Therefore, as can be seen in Figure 4, the surface charge of the modified membrane increases as the pH increases.
# Decentralized Storage with Access Control and Data Persistence for e-Book Stores
## 2 Distributed Ledger Technology
### Ethereum as a Decentralized Platform  
Ethereum [13] is another cryptocurrency with the notion of blockchain, but it is widely recognized as a decentralized platform designed for the execution of self-executing programs known as smart contracts [14; 15]. The description language for these smart contracts is considered Turing-complete, allowing for the support of various types of computations. This subsection provides an overview of Ethereum as a decentralized platform and its capabilities.  
The concept of accounts is crucial in the context of smart contracts. Accounts are categorized into two types: externally owned accounts (EOAs) and contract accounts, each assigned a unique address as an identifier. EOAs are accounts managed by regular users using their private keys. Conversely, contract accounts are specialized accounts responsible for executing smart contracts, housing internal code and data storage (note that in Ethereum, once a contract account is created, its internal code is fixed and cannot be altered).  
In the Ethereum network, each node is equipped with a virtual machine called an Ethereum virtual machine (EVM), which executes the code embedded in a contract account on each node. The execution of the internal code within a contract account is triggered by transactions initiated by an EOA. In these transactions, the contract account serves as the counterparty of the EOA, and the desired functions and parameters are included in the transaction as supplementary data. To prevent infinite execution of loops and reduce the burden on the network, each instruction in the code is assigned a predetermined cost (e.g., 3 for ADD, 5 for MUL, etc.), and the execution of an instruction consumes a specific amount of gas, which corresponds to the transaction fee. This gas mechanism ensures that resource usage is controlled during code execution. However, it is important to note that this mechanism can increase the gas costs associated with writing data, making Ethereum less feasible as a data repository for large files, such as e-books, due to potential high costs. On the other hand, simple data fetching without state transitions or money transfers can be performed without creating a transaction, leading to no gas consumption in such cases.  
One important application of smart contracts is non-fungible tokens (NFTs) [16]. In the NFT standard, ERC721 [17], each token is identified by a uint256 token ID, and the owner of each token is recorded on the blockchain through mappings on the contract. The owner of an NFT has the right to transfer their NFT to another address so that the NFT can be used as a digital collector's item that can be bought and sold, such as games or art. The most notable feature of NFTs is that ownership is managed on the blockchain, so information about the item and its owner is never lost.
# Evaluating 60 GHz FWA Deployments for Urban and Rural Environments in Belgium
## 3 Evaluation Framework
### User Density and Traffic  
We define the users' traffic based on the operator's inputs. The typical home subscriber's internet consumption is 30 Mbps, while the TV consumption is 6 Mbps, based on data from the network operator. The model defines that 80% of home users use TV and Internet services (36 Mbps), and the other 20% only use the Internet (30 Mbps). In addition, a headroom allows home users to have a peak internet connection of 1 Gbps, meaning that a user could made a speed test and the network should provide this speed.  
The point of presence (PoP) is defined to support a maximum of 100 user connections for an aggregated bit rate of 4.48 Gbps/PoP. This explains that the area of interest should contain only 100 connected homes. In addition, user density is determined by the density of houses in the area and the desired penetration ratio of the operator in the investigated area. These are detailed in the Use Cases subsection.
# Production and Processing of a Spherical Polybutylene Terephthalate Powder for Laser Sintering
## 2 Materials and Methods
On the basis of 216 images, 51862 particles were counted and evaluated using an in-house developed imageJ script and MATLAB evaluation procedure, described in [28]. Powder flowability: characterization of the powder flowability was carried out on a Revolution Powder Analyzer (RPA) (Mercury Scientific, Newtown, CT, United States). An exact measure of 25 mL powder at tapped density was added to a rotating drum with a diameter of 50 mm. The drum was rotated with a speed of 0.6 rpm, while a camera recorded 384 avalanche events. Each time directly following an avalanche, the avalanche angle and roughness of the powder surface were evaluated. Thermal analysis: differential Scanning Calorimetry (DSC) measurements were carried out on a DSC 25 (TA Instruments, New Castle, DE, United States). All measurements were conducted under a nitrogen atmosphere, from 25 \({}^{\circ}\)C to 250 \({}^{\circ}\)C, with heating and cooling rates of 10 \({}^{\circ}\)C/min. Rheology: a RG20 high pressure capillary rheometer ([PERSON], Buchen, Germany) was used to assess rheological properties. Measurements were carried out at 250 \({}^{\circ}\)C with a nozzle with a 1 mm diameter and 20 mm length. Both channels were used simultaneously for measurement, only relative results are provided. Mechanical tests: mechanical tests were performed on a Z100 universal testing machine (Zwick Roell, Ulm, Germany). The tests were performed according to the ISO 527-1 standard, with testing geometries of type ISO 527-2A-1 BA-25. Laser Sintering: laser sintering trials were conducted on a Sinterstation 2000 commercial laser sintering machine (DTM, Austin, TX, United States) equipped with inserts on both sides of the central powder bed to allow for the processing of reduced amount of material. The machine disposes of a 50 W CO\({}_{2}\) laser operating at a wavelength of 10.6 \(\upmu\)m. New layers were deposited on the powder bed by means of a counter-rotating roller. The process parameters are listed in Table 1 below. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Symbol** & **Value** \\ \hline Powder bed temperature & T\({}_{\text{bed}}\) & 213–215 \({}^{\circ}\)C \\ Piston temperature & T\({}_{\text{piston}}\) & 160 \({}^{\circ}\)C \\ Cylinder temperature & T\({}_{\text{cylinder}}\) & 200 \({}^{\circ}\)C \\ Powder feed temperature & T\({}_{\text{feed}}\) & 170 \({}^{\circ}\)C \\ Laser power & P\({}_{\text{L}}\) & 8 W \\ Laser scan speed & v\({}_{\text{s}}\) & 5 m/s \\ Hatch distance & d\({}_{\text{s}}\) & 0.30 mm \\ Layer thickness & t\({}_{\text{l}}\) & 0.12 mm \\ Energy density & \(\rho_{\text{E}}\) & 44.4 J/cm\({}^{3}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Laser sintering process parameters.
# Key Issues on Integrating 5G into Industrial Systems
## 5 Integration of 5G with Industrial Systems
### Three Integration Paths
#### 5.1.3 Modification to the 5G Protocol  
For optimizing the 5G protocol to achieve compatibility with field bus protocols, inspiration can be drawn from the design concept of the WirelessHART protocol. Considering that the 5G protocol emphasizes the physical layer and data link layer in the wireless network architecture, necessary adjustments need to be made to achieve integration with the field bus protocol, so as to ensure the implementation of the required functions. Taking Modbus TCP/IP protocol as an example, the core components of the TCP/IP protocol are its network layer and transport layer. In the TCP/IP model, the network interface layer (corresponding to the physical layer and data link layer in the OSI model) is usually considered to be a black box. Most protocols at the network interface layer are not mandatory in the TCP/IP protocol group; therefore, these protocols are replaceable. For example, the wired communication protocols and devices (such as fiber optic, copper, Ethernet, High-level Data Link Control, Frame Relay, etc.) at the network interface layer can be replaced with wireless protocols (such as 4G, 5G, WiFi, etc.). Thus, theoretically, 5G technology can be used to replace the Hardware Layer in the Modbus TCP/IP protocol. Based on this idea, the upper layer protocol of the Modbus TCP/IP protocol can be implemented, thus forming a new communication protocol with real-time support. The modified model is shown in Figure 5.
## 3 Results and Discussion
### Artificial Neural Network Prediction Analysis
#### 3.2.2 Proposed ANN Model  
It is understood from CFD analyses that the performance indices of centrifugal fans are dependent on geometrical configurations as well as operating variables. The input factors influencing the performance are the ellipsoidal hub ratio (\(\mathrm{R_{E}}\)) and volume coefficient (\(\phi\)) for the optimized hub configuration, i.e., ellipsoidal hub model. The output parameters chosen for ANN studies are head coefficient (\(\psi\)) and relative theoretical efficiency (\(\eta_{Rt}\)). The model has an input layer, output layer and hidden layer. The input layer consists of two neurons, representing the flow coefficient and ellipsoidal ratio for an ellipsoidal hub configuration. The output layer has two neurons for head coefficient and relative theoretical efficiency for the ellipsoidal hub configurations. The range used for input and output parameters is shown in Table 4. A schematic representation of the ANN model used for the prediction of the performance of the centrifugal fan is depicted in Figure 22.