esa-sceva/satcom-chunk-collection huggingface dataset:
# Adsorption of Ni2+ and Cd2+ from Water by Calcium Alginate/Spent Coffee Grounds Composite Beads
## 3 Results and Discussion
### Kinetic Experiments
The swelling could be the reason of why the CA-SCGs beads did not show any improvement in the kinetics versus the CA beads during the adsorption of Ni\({}^{2+}\). On the contrary, the swelling was greater in the CA-SCGs beads because they have less alginate relative to the concentration of Ni\({}^{2+}\) and it could explain why the adsorption of Ni\({}^{2+}\) by CA-SCGs beads was slower than the adsorption by CA beads. It could also describe why the EDX spectra showed more similar contents of Ni\({}^{2+}\) between the CA beads and CA-SCGs beads, but a large difference in the content of Cd\({}^{2+}\), because only the alginate portion of the bead is swelled, not the portion of SCCs. This phenomenon is more visible at the lowest dose of adsorbent because the adsorbent is exposed to a much more amount of Ni\({}^{2+}\). Figure 14 shows photos of this swelling. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Adorbent**} & \multirow{2}{*}{\(\mathbf{R^{2}}\)} & **q\({}_{\mathbf{e}}\) Experimental** & **q\({}_{\mathbf{e}}\) Calculated** & \multirow{2}{*}{**k\({}_{2}\) (g/mg-min)**} & \multirow{2}{*}{**h (mg/g-min)**} \\  & & **(mg/g)** & & & \\ \hline CA–SCGs beads (Cd\({}^{2+}\) 10 ppm) & 0.9992 & 1.8320 & 1.8702 & 0.0212 & 0.0742 \\ CA beads (Cd\({}^{2+}\) 10 ppm) & 0.9994 & 1.7233 & 1.7844 & 0.0209 & 0.0665 \\ CA–SCGs beads (Ni\({}^{2+}\) 10 ppm) & 0.9993 & 1.6240 & 1.6556 & 0.0271 & 0.0742 \\ CA beads (Ni\({}^{2+}\) 10 ppm) & 0.9988 & 1.1400 & 1.1685 & 0.0304 & 0.0415 \\ CA–SCGs beads (Cd\({}^{2+}\) 100 ppm) & 0.9994 & 16.8640 & 17.2414 & 0.0022 & 0.6536 \\ CA beads (Cd\({}^{2+}\) 100 ppm) & 0.9981 & 15.2940 & 15.8730 & 0.0016 & 0.3953 \\ CA–SCGs beads (Ni\({}^{2+}\) 100 ppm) & 0.9963 & 9.5436 & 9.8425 & 0.0033 & 0.3149 \\ CA beads (Ni\({}^{2+}\) 100 ppm) & 0.9956 & 7.4822 & 7.7280 & 0.0047 & 0.2810 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Adsorption kinetic parameters.
# GRACE/GFO and Swarm Observation Analysis of the 2023-2024 Extreme Drought in the Amazon River Basin
## 3 Data and Methods
### Data
#### 3.1.3 Global Precipitation Measurement (GPM) Data  
GPM is a collaborative international satellite mission between the National Aeronautics and Space Administration and Japan Aerospace Exploration Agency that utilizes multiple sensors, satellites, and algorithms in combination with a satellite network and rain gauge inversion to obtain more accurate PRE data, which provides a global grid of half-hourly, daily, and monthly average PRE. Integrated multi-satellite retrievals for GPM is an algorithm for generating tertiary products for GPM that combines data from all passive  
Figure 1: (**a**) Topographic map of the ARB and (**b**) sea temperature anomaly regions represented by NINO indices.  
microwave instruments in GPM to provide rainfall estimates [38]. In this study, we used 0.1\({}^{\circ}\)\(\times\) 0.1\({}^{\circ}\) monthly total PRE gridded data to analyze the 2023 extreme drought in the ARB.
## 4 Performance Evaluation
### Comparison Study  
Our model is compared with other state-out-of-art models commonly used for classification, including Resnext [54], a variant of ResNet, fine-grained visual categorization [55], which combines the attention mechanism, and MobileViT, used as a base model of MobileViT-Plus. The results are not as good as the model obtained by our model.  
Table 2 shows the comparison results between some widely adopted models in medical images on varying evaluation metrics. Among them, Resnext101 performed the worst in all indicators, even worse than ResNet101, indicating that the improvements in Resnext may not be suitable for medical image processing. Se_resnet101, Se_resnet50, and Senet154 are CNNs with attention mechanisms added, which exhibit improvements relative to ResNet. Se_resnet50 and Senet154 also outperform MobileViT, which uses self-attention. The metrics of MobileViT and MobileViT-Plus are similar, but MobileViT-Plus is more economical regarding computational resources. Figure 6 shows the training loss and test loss of each epoch and the ROC curves of the comparison models. The disparity is still evident compared with our model's ROC curve in Figure 5c.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Model** & **Accuracy** & **Precision** & **Recall** & **F\({}_{1}\) Score** & **AUC** \\ \hline MobileViT-Plus & 88.00\% & 87.97\% & 88.00\% & 0.8797 & 0.963 \\ ResNet101 & 81.33\% & 81.31\% & 81.33\% & 0.8123 & 0.943 \\ Our model & 93.67\% & 93.71\% & 93.67\% & 0.9366 & 0.994 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Our model and ablation study.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Model** & **Accuracy** & **Precision** & **Recall** & **F\({}_{1}\) Score** & **AUC** \\ \hline Resnext101 & 79.83\% & 80.40\% & 79.83\% & 0.7943 & 0.947 \\ Se\_resnet101 & 86.50\% & 86.47\% & 86.50\% & 0.8640 & 0.963 \\ Se\_resnet50 & 90.17\% & 90.30\% & 90.16\% & 0.9020 & 0.973 \\ Senet154 & 88.00\% & 88.17\% & 88.00\% & 0.8796 & 0.961 \\ MobileViT & 87.33\% & 87.54\% & 87.33\% & 0.8721 & 0.967 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Comparing base models and other classic models.  
Figure 5: The loss and ROC curves of three models for comparison. (**a**) MobileViT-Plus, (**b**) ResNet101, and (**c**) Our model.  
Figure 6: _Cont._
## 2 Simulation Models of Human Body and HBC Devices
### Transmitter and Receiver Models  
A wearable transmitter worn on the human wrist was modeled as shown in Figure 3. The transmitter model consisted of a signal source with an output impedance of 50 \(\Omega\), a conductive plate representing a circuit board, electrodes that are in contact with the human body, and conductive wires. The one-electrode transmitter had a signal electrode connected to the signal source, as shown in Figure 3a, and the two-electrode transmitter had a signal electrode and a ground electrode as shown in Figure 3b. The dimensions of the circuit board and electrodes were 40 mm \(\times\) 24 mm, and 8 mm \(\times\) 24 mm, respectively, and the distance between the electrodes and the board was 10 mm. The circuit board, electrodes, and wires were modeled as perfect electric conductors with no electrical resistance. A sinusoidal signal with an amplitude of 1 V and a frequency of 10 MHz was applied between the transmitter circuit board and the signal electrode.  
Figure 2: Location of the transmitter and the receiver electrode around the arm: (**a**) One-electrode transmitter; (**b**) Two-electrode transmitter.  
The stationary receiver was modeled as shown in Figure 1a,b. The receiver consisted of a frame, a receiver electrode and an input resistor. The dimensions of the receiver electrode were \(5\) mm \(\times\)\(5\) mm. A 2000 \(\Omega\) resistor was installed between the top of the frame and the electrode, as shown in Figure 1b. The voltage measured across this resistor during signal reception was regarded as the received voltage. The frame of the receiver and the receiving electrode were modeled as perfect electric conductors.
# UAV-BS Site Planning Based on Circular Coverage Strategy
## 2 Background and Related Work
### UAV Air Subscriber  
The multi-rotor \"Bee\" UAV developed at the Beijing Institute of Technology is used for agricultural plant protection, urban planning, mine surveying, and other work [26]. In the field of logistics, UAVs are used for tasks such as express delivery and material transportation [9]. In the field of environmental protection, UAVs are used for tasks such as environmental monitoring and waste disposal. In the security field, UAVs can be used for patrolling, surveillance, and other tasks. The \"Rainbow\" series UAV, jointly developed by the Chinese Air Force, Aerospace Science and Technology Corporation, and other units, can perform reconnaissance, listening, intelligence collection, communication relay, electronic  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Role in** & **Effect** & **Application Scenario** & **Research Progress** \\ \hline Air subscriber & Directly connected to the ground network to communicate with other users and accessible worldwide; operators can remotely direct UAV behavior, thereby reducing human resource investment and improving network efficiency. & Emergency communications, agricultural protection, [9, 10, 11, 12] & Emergency communications, agricultural protection, [9, 10, 11, 12] & Emergency communications, traffic monitoring, large public events, urban peak hours, crowded places \\  & The UAV acts as an intermediate node to transmit communication signals from the sender to the receiver to expand the range and improve the quality of communication. & & \\  & It undertakes the communication function of the space-based network layer and provides communication services to ground users and air users. Interconnection with satellite constellations and sea-based networks to achieve global coverage is an important link in the future network. & Emergency communication, earthquake mitigation, field exploration, Marine QoS guarantee, logistics distribution, ground network supplement \\ \hline \hline \end{tabular}
\end{table}
Table 1: Research status of UAV communication.  
jamming, and other tasks in the air [10]. In the field of construction engineering, UAVs can perform inspection, measurement, and monitoring of buildings and infrastructure. For example, they can perform exterior wall inspection at high altitudes, or perform on-site monitoring and building surveying on construction sites [11]. In the field of emergency communication, UAVs can be used for search and rescue, fire monitoring, etc. [12]. UAVs can enter dangerous areas to search and monitor them, and provide real-time data and intelligence to rescue workers; for example, the Philo UAV developed by the Italian National Research Council can provide real-time image and video data at the scene of a fire to assist firefighters in fighting the blaze.
# Research on Freight Transportation Carbon Emission Reduction Based on System Dynamics
## 3 System Flow Diagram and Structural Equation
### Simulation Analysis
#### 4.2.2 Railway Freight Environmental Protection Investment  
Set three states:  
State 1: Initial state.  
State 2: Increase the railway freight environmental protection investment, with an investment coefficient of 5.6e + 07 (obtained based on historical data).  
State 3: Add railway freight environmental protection investment, with an investment coefficient of 7.6e + 07.  
From the curves in Figure 5 of the comparison of the three states, it can be seen that increasing environmental protection investment can reduce carbon dioxide emissions to a certain extent. This is also the reason why the government has always insisted on using funds for environmental protection management. The carbon dioxide emissions are reduced as the investment coefficient increases.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline
**Year** & **Actual Data** & **Simulation Data** & **Error** & **Year** & **Actual Data** & **Simulation Data** & **Error** \\ \hline
2001 & 110,863 & 110,863 & 0 & 2011 & 487,940 & 455,609 & \(-\)0.06626 \\
2002 & 121,717 & 122,563 & 0.006951 & 2012 & 538,580 & 539,431 & 0.00158 \\
2003 & 137,422 & 134,562 & \(-\)0.02081 & 2013 & 592,963 & 595,415 & 0.004135 \\
2004 & 161,840 & 151,924 & \(-\)0.06127 & 2014 & 643,563 & 655,536 & 0.018604 \\
2005 & 187,319 & 178,919 & \(-\)0.04484 & 2015 & 688,858 & 711,475 & 0.032833 \\
2006 & 219,439 & 207,087 & \(-\)0.05629 & 2016 & 746,395 & 761,563 & 0.020322 \\
2007 & 270,092 & 242,596 & \(-\)0.1018 & 2017 & 832,036 & 825,229 & \(-\)0.00818 \\
2008 & 319,245 & 298,595 & \(-\)0.06468 & 2018 & 919,281 & 919,552 & 0.000295 \\
2009 & 348,518 & 352,934 & 0.012671 & 2019 & 990,865 & 1,016,750 & 0.026124 \\
2010 & 412,119 & 385,296 & \(-\)0.06509 & & & & \\ \hline \end{tabular}
\end{table}
Table 8: Error comparison.  
Therefore, increasing railway freight environmental protection investment is an effective policy to reduce carbon emissions in the transportation industry.
# Low-Complexity Channel Codes for Reliable Molecular Communication via Diffusion
###### Abstract  
It is envisioned that healthcare systems of the future will be revolutionized with the development and integration of body-centric networks into future generations of communication systems, giving rise to the so-called \"Internet of Bio-nano things\". Molecular communications (MC) emerge as the most promising way of transmitting information for in-body communications. One of the biggest challenges is how to minimize the effects of environmental noise and reduce the inter-symbol interference (ISI) which in an MC via diffusion scenario can be very high. To address this problem, channel coding is one of the most promising techniques. In this paper, we study the effects of different channel codes integrated into MC systems. We provide a study of Tomlinson, Cercas, Hughes (TCH) codes as a new attractive approach for the MC environment due to the codeword properties which enable simplified detection. Simulation results show that TCH codes are more effective for these scenarios when compared to other existing alternatives, without introducing too much complexity or processing power into the system. Furthermore, an experimental proof-of-concept macroscale test bed is described, which uses pH as the information carrier, and which demonstrates that the proposed TCH codes can improve the reliability in this type of communication channel.  
future wireless networks; 6G; molecular communications; diffusion-based; channel coding; TCH codes +
Sensors
## 2 Materials and Methods
### Polymer Modification  
Synthesis of PLGA-PEG-FA was carried out in two steps: PLGA activation and coupling of PEG, followed by FA conjugation [43; 44], as shown schematically in Figure 1. Briefly, PLGA was activated by DCC and NHS in DCM with a molar ratio of PLGA:DCC:NHS = 1:5:5, where reaction was carried out overnight at room temperature under nitrogen atmosphere. The resultant solution was filtered (Watman #1 filter) to remove dicyclohexylurea. For PEG coupling, activated PLGA solution was treated with PEG at a molar ratio of 1:5 and left to react overnight under nitrogen atmosphere. Polymer was washed by three cycles of precipitation using three volumes of cold organic mixture of methanol-diethylether (50/50) followed by centrifugation, discarding supernatant and resuspending in DCM. In the last cycle, after centrifugation and removal of supernatant, polymer was dried under vacuum. To attach FA to polymer, PLGA-PEG was dissolved in DMSO and treated with FA in DMSO at a molar ratio of 1:5 with overnight stirring at room temperature under nitrogen atmosphere. Then, the solution was filtrated (Watman #1 filter) and set to dialyze in a Spectra/Por(r) Membrane MWCO 3500 in 5 mM sodium carbonate (pH 8.0) buffer for four hours. Next, buffer was replaced and sample was dialyzed for four more hours, followed by overnight dialysis in deionized water. Finally, PLGA-PEG-FA was lyophilized to remove water and trace amounts of organic solvent in lyophilized Freezone 4.5 (Laboconco, Kansas City, MO, USA). The structure of the copolymer was confirmed by Fourier transform infrared spectroscopy in the equipment FT-IR spectrometer spectrum (Perkin Elmer, Lantrisant, UK). For FT-IR measurements, polymer was set directly onto an attenuated total reflectance (ATR) crystal and spectrum was collected in a range between 4000 and 550 cm\({}^{-1}\) with a resolution of 4 cm\({}^{-1}\) (16 scans per sample).
## 5 VoLTE Network Experimental Implementation
### Experimental Platform Conclusions  
Our experimental scenario took place inside a laboratory without eNB's signal amplification. The implementation of both the EPC and eNB initially utilized Linux version 16.04. However, challenges arose due to issues regarding required libraries that could not be upgraded to newer versions. This led to the need for additional installations of parallel libraries to resolve the problem. During initial testing, the base station failed to meet network requirements adequately, resulting in frequent loss of range and communication regardless of the device used. This caused the station to shut down, leaving it unable to re-coordinate, and often necessitated the reprogramming of UICC cards. Moreover, when connecting a second device, tests had to be conducted very closely to the station, while instances occurred where simultaneous connections were not supported. These issues significantly delayed the implementation process. Upon investigation, it was discovered that the specific Linux version was unsupported and could not be upgraded. Attempts to upgrade the existing version proved to be unsuccessful, leading to upgrading to Ubuntu Linux 18.04 to address the problem.  
By leveraging SDR devices instead of PCIe boards, the platform facilitates voice communication over a private LTE network. The integration of OAI software and an Asterisk server streamlines the development of a portable mobile base station, enabling seamless voice transmission and ensuring secure telecommunications. We found that the network remains stable for a small amount of UEs conducting VoLTE calls, thereby maintaining satisfactory levels of QoS and QoE. VoLTE calls between users were achieved without experiencing any delays or interruptions inside the experimental area. To achieve an improvement in the eNB's coverage area and to reach the simulation results, an intermediate amplifier needs to be applied. The output limitation of the SDR's transmit power is one of the primary causes of this constrained testing environment. In [33], the authors demonstrated how varied 4G/5G cell sizes may be created by utilizing the proper external devices, such as amplifiers, antennas, and filters that have been calibrated by the SDR device specifications. A second eNB can also help to reduce network congestion and delays and increase the coverage area, as seen in the simulation section. In our experiment, UEs were also able to send text messages and other data (e.g., photographs and video files) to each other using appropriate applications without facing any problems. Data transfer was fast without any lags or errors. Therefore, in the case of a search and rescue mission or emergency cases, the coordination center could use a laptop to manage the configured situation, enabling live communication and data transfer through the network's UE devices.
## Appendix A  
Assuming that the rotation \(\overline{\mathbf{q}}\) is accomplished during a certain period and that the corresponding body angular velocity is \(\mathbf{\omega}\), \(\dot{\overline{\mathbf{q}}}=\frac{1}{2}\overline{\mathbf{q}}\otimes\overline{\mathbf{ \omega}}\)[30], where \(\overline{\mathbf{\omega}}=[0,\mathbf{\omega}]\). The \(\mu\)-th power of \(\overline{\mathbf{q}}\) is written as \(\overline{\mathbf{q}}^{\mu}\), which is a unit quaternion that denotes scaling the rotation angle around the virtual axis with \(\mu\in[0,1]\)[32].  
A three-element vector \(\mathbf{p}\) rotating according to \(\overline{\mathbf{q}}\) is written as \(\overline{\mathbf{q}}\otimes\overline{\mathbf{p}}\otimes\overline{\mathbf{q}}^{*}\triangleq R (\overline{\mathbf{q}})\mathbf{p}\) with \(\overline{\mathbf{p}}=\left[0,\mathbf{p}^{T}\right]^{T}\).  
For general quaternions, the error between the measurement and the expectation is defined as \(\delta\overline{\mathbf{q}}\) from \(\overline{\mathbf{q}}=\dot{\overline{\mathbf{q}}}\otimes\delta\overline{\mathbf{q}}\). The derivative form is \(\delta\overline{\mathbf{q}}=\dot{\overline{\mathbf{q}}}^{*}\otimes\left(\dot{\overline {\mathbf{q}}}-\dot{\overline{\mathbf{q}}}\otimes\delta\overline{\mathbf{q}}\right)\)[16].  
According to \(R(\delta\overline{\mathbf{q}})\approx I_{3}+\left\lfloor\delta\mathbf{\omega}\times\right\rfloor\)[23], there is \(R(\overline{\mathbf{q}})=\dot{R}\big{(}\dot{\overline{\mathbf{q}}}\big{)}R(\delta \overline{\mathbf{q}})\approx\dot{R}\big{(}\dot{\overline{\mathbf{q}}}\big{)}\big{(} I_{3}+\left\lfloor\delta\mathbf{\theta}\times\right\rfloor)\).  
Assuming that there are two quaternions, \(\overline{\mathbf{q}}=\left[q_{0},\mathbf{q}^{T}\right]^{T}\) and \(\overline{\mathbf{p}}=\left[p_{0},\mathbf{p}^{T}\right]^{T}\), the following equation exists:  
\[\overline{\mathbf{q}}\otimes\overline{\mathbf{p}}=\begin{bmatrix}q_{0}&-\mathbf{q}^{T}\\ \mathbf{q}&q_{0}I_{3}+\left\lfloor\mathbf{q}\times\right\rfloor\end{bmatrix}\otimes \overline{\mathbf{p}}=\begin{bmatrix}p_{0}&-\mathbf{p}^{T}\\ \mathbf{p}&p_{0}I_{3}+\left\lfloor\mathbf{p}\times\right\rfloor\end{bmatrix}\otimes \overline{\mathbf{q}}. \tag{1}\]
## 4 Discussion
### Climatic Controls on GPP and WUE
The highest negative correlation coefficient between WUE and Pr was found in wetland among vegetation types (Figures 12 and 14d), and Pr may be the main climatic factor responsible for the decreasing trend of wetland WUE. Combined with the fact that the wetland was more distributed in the semi-humid zone of southwest China (Figure 1), and that it exhibited large \(CV\) for WUE (Table 2), we inferred that the large fluctuation of WUE in this region was caused by the effect of Pr on wetland WUE. The correlation distribution of individual vegetation WUE and RH was more consistent with Pr across arid-humid zones (Figure 14a,d). Unlike Pr, RH mostly showed a decreasing trend in China (Figure 8a). Lower RH will promote the outward transpiration of water from plants to reduce WUE. This is different from the conclusion obtained in this study that WUE showed a negative correlation with RH in each arid-humid zone, which may also be related to the contribution of other factors (e.g., Ta) to WUE. Shrubland WUE displayed a positive correlation with RH (Figures 12 and 14a). Although the correlation coefficients between shrubland WUE and the five climatic factors were similar in magnitude, it was relatively high with RH, and presumably the decline in shrubland WUE since 2001 may be related to the decrease in RH. It should be noted that the correlation analysis, which can directly reflect the correlation between the two factors, was selected for this study. However, the relationship between each climatic factor on WUE as well as GPP is complex, and the five climatic factors selected in this study are not completely independent; their interactions may also play a role in the variations of GPP and WUE [61]. Future research should consider this issue to better determine the impact of climate change on GPP and WUE. Most previous studies have focused on the correlation of GPP and WUE with Ta and Pr [16; 62]. Although this study also found a high correlation of GPP and WUE with Ta and Pr, the main climatic factors affecting GPP and WUE were somewhat different in each arid-humid zone and vegetation type. Besides the major vegetation types, there are some regional characteristics of GPP and WUE values of wetland and shrubland in response to climatic factors in different aridity gradients. Therefore, the response of GPP and WUE to climatic factors in each vegetation type can be further determined from the perspective of aridity gradient.
## 4 Classification of Energy Efficient MAC Protocols for UWSNs
### Frequency Domain
#### 4.1.3 Time Division Multiple Access (TDMA)-Based MAC Protocol  
TDMA divides time intervals into several time slots (called frames), with each frame assigned to a particular communicating sensor node, where intervals and upper bits are merged into frames [64]. These time frames act as guards that play an important role to prevent the collisions of data packets in UWSNs, from adjacent sensor node, which is allotted a separate and unique time slot [83]. The simplicity of TDMA makes it an excellent choice for UWSNs at the MAC level, but the main drawback is the presence of propagation delay and delay variance in acoustic channels. In some scenarios, this makes synchronization between nodes difficult. Furthermore, designing the guard period is a vital component that must be addressed in order to avoid data collisions [64]. Ref. [48] provides a more detailed description of the shortcomings in TDMA.