esa-sceva/satcom-chunk-collection huggingface dataset:
# Early-Age Cracking in Concrete: Causes, Consequences, Remedial Measures, and Recommendations
## 5 Consequences of Early-Age Cracking  
Early-age cracking is a common occurrence in concrete structures. However, early-age cracks do not cause the failure of concrete structures if the structural tolerance level is not exceeded [76]. However, these cracks affect the appearance of structures and raise public concern and attention regarding safety issues. The experts (engineers, architects, and concrete practitioners) understand that early-age cracking does not usually affect the general safety of structures. On the other hand, the public may not understand this. As a result, the image of contractors and consultant may be affected, where the public may blame the construction stakeholders for the lower construction quality. The aesthetic appearance of concrete structures is also greatly affected due to the early-age cracking in concrete surface if not repaired.  
Early-age cracking, if left unchecked, may lead to long-term maintenance issues. This early-age cracking may be a temporary shortcoming, but the owners or building management personnel assign contractors to repair early-age cracks rapidly. Improper remedial work leads to further problems, such as water ponding. If these cracks are permanent and are not solved immediately, they could also allow the ingress of aggressive agents, such as chloride, sulfate, and carbonates, which may induce the corrosion of steel reinforcement and the carbonation of concrete to shorten the service life of concrete structures [60; 77; 78].  
The function of some concrete structures may be affected over time, especially in structures like water reservoirs and roofs, due to early-age cracking. The cracking may cause leakage in these structures [79]. If the concrete cracking continues to develop, it may affect the bearing capacity of the structure and speed up fatigue failure [10; 80]. Moisture leakages are also harmful to building users and their property, especially to electronic devices. Further research in related topics is encouraged since literature in this area seems to be scarce.  
Cracking is not allowed on certain special functional structures, such as nuclear power plants, chemical and radioactive waste storages, nuclear containment vessels, liquefied natural gas tanks, and waste disposal structures. It would be a disaster if the chemicals leak through these structures [81]. These leaking agents are very aggressive and harmful, where they not only pollute the environment, but are also very harmful to humans.
## 2 System Model
### Structure of PPM Signal  
PPM is a communication technology that transmits signals through different positions of pulse signals in the time domain. It can be divided into a binary PPM signal and \(Q\)-ary PPM signal. The binary PPM signal can also be regarded as a special case of the \(Q\)-ary PPM signal. Assuming that the duration of a PPM symbol is \(T_{s}\), \(T_{s}\) is evenly divided into \(Q=2^{M}\) equal time slots and a time slot is selected from the \(Q\) time slots to transmit a pulse signal according to the data to be transmitted. For the convenience of analysis, we assume that the shape of the transmitted pulse is rectangular, and the pulse duration is equal to the time slot width. The signal model is  
\[s(t)=A\sum_{j}p(t-jT_{s}-k\delta)\,. \tag{1}\]  
where \(p(t)\) represents the pulse waveform, \(T_{s}\) is the PPM symbol duration and \(k\) is a vector composed of data to be transmitted, where \(k\in[1,2^{M}]\). \(\delta\) indicates the slot width. The PPM signal is shown in Figure 1, where (a) is a binary PPM, (b) is a 4-ary PPM and (c) is a 8-ary PPM. The mapping of the data in the figure to PPM symbols adopts the natural mapping method.
## 1 Introduction
A-WSNs [1,16] consist of a set of nodes with scanty power supplies, which moreover communicate with one another by way of low-consumption radio modules. In addition, they have one or more nodes with bigger power supplies which act as sinks. These communicate with a remote station using longer-range connections (via satellite, GPRS, _etc._). This type of network should not be confused with the ones in which each node has a large power supply and connects directly to the base station. These are isolated buoys linked to a data collection centre using satellite communications. In this case, since systems incorporate considerable computational capacities, power and communications resources they are not considered as A-WSN. A-WSNs do not present the problems described above in the case of UW-ASNs, but they do pose other problems; for example, they have to transmit via data cables running from underwater sensors to buoys on the surface. Where these sensors are located at great depths, the problems that arise can also be serious. In short, there is no ideal solution, and the most suitable technology will depend on the particulars of each case. The purpose of this article, following an introduction to the component elements of an A-WSN for oceanographic monitoring, is to provide an overview of the systems that have been developed in the last ten years based on the deployment of networks of this kind. The study looks basically at the most significant deployments that have been implemented world-wide. The most relevant information was gathered on each one, followed by a comparative and systematic analysis of the different solutions. As a result of that study, we have identified and summarized the main elements used (hw/sw infrastructure) when implementing the different monitoring systems, and their principal features (measurements taken, characteristics of deployment, harvesting systems, _etc._). Section 2 summarizes the general structure of an oceanographic A-WSN and the elements commonly used in implementing the network. Section 3 details the method used in the systematic review. Section 4 summarizes the results of the study. Section 5 presents a discussion of those results. Finally, Section 6 presents the conclusions and details the principal challenges and difficulties entailed in deploying an A-WSN for oceanographic monitoring.
_Int. J. Mol. Sci._**2010**, _11_, 1434-1457; doi:10.3390/ijms11041434  
International Journal of  
Molecular Sciences  
ISSN 1422-0067  
www.mdpi.com/journal/ijms  
_Article_  
Origin and Distribution of Thiophenes and Furans in Gas Discharges from Active Volcanoes and Geothermal Systems  
**[PERSON] 1,2,*, [PERSON] 2, [PERSON] 1 and [PERSON] 1,2**  
1 Department of Earth Sciences, University of Florence, Via G. La Pira, 4, 50121 Florence, Italy; E-Mails: [EMAIL_ADDRESS] (F.C.); [EMAIL_ADDRESS] (O.V.)  
2 CNR-IGG Institute of Geosciences and Earth Resources, Via G. La Pira, 4, 50121 Florence, Italy; E-Mail: [EMAIL_ADDRESS] (G.M.)  
* Author to whom correspondence should be addressed: E-Mail: [EMAIL_ADDRESS]; Tel.: +39-0552-757-477; Fax: +39-0552-84571.  
_Received: 7 January 2010; in revised form: 30 March 2010 / Accepted: 30 March 2010 / Published: 31 March 2010_  
The composition of non-methane organic volatile compounds (VOCs) determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C\({}_{2}\)-C\({}_{20}\) species pertaining to the alkanes, alkenes, aromatics and \(O\)-, \(S\)- and \(N\)-bearing classes of compounds. Thiophenes and mono- aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C\({}_{4}\)H\({}_{8}\)O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal _vs._ magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection.  
heteroaromatics; geothermal fluids; volcanic fluids; furans; thiophenes
# Options for Performing DNN-Based Causal Speech Denoising Using the U-Net Architecture +
###### Abstract  
Speech enhancement technology seeks to improve the quality and intelligibility of speech signals degraded by noise, particularly in telephone communications. Recent advancements have focused on leveraging deep neural networks (DNN), especially U-Net architectures, for effective denoising. In this study, we evaluate the performance of a 6-level skip-connected U-Net constructed using either conventional convolution activation blocks (CCAB) or innovative global local former blocks (GLFB) across different processing domains: temporal waveform, short-time Fourier transform (STFT), and short-time discrete cosine transform (ST DCT). Our results indicate that the U-Nets can receive better signal-to-noise ratio (SNR) and perceptual evaluation of speech quality (PESQ) when applied in the STFT and ST DCT domains, with comparable short-time objective intelligibility (STOI) scores across all domains. Notably, the GLFB-based U-Net outperforms its CCAB counterpart in metrics such as CSIG, CBAK, COVID, and PESQ, while maintaining fewer learnable parameters. Furthermore, we propose domain-specific composite loss functions, considering the acoustic and perceptual characteristics of the spectral domain, to enhance the perceptual quality of denoised speech. Our findings provide valuable insights that can guide the optimization of DNN designs for causal speech denoising.  
Speech denoising; causal U-Net; short-time Fourier transform; short-time discrete cosine transform; regression mapping +
Footnote †: This paper is an expanded version of [PERSON]; [PERSON]; [PERSON] Suitable domains for causal speech denoising using DNN with U-Net architecture. In Proceedings of the 7 th International Conference on Knowledge Innovation and Invention 2024 (ICKII 2024), Nagoya, Japan, 16-18 August 2024.
## 5 Results and Discussion
### Comparison of Time Series-Based Models  
Figure 3 presents a detailed comparison of MAPE values across various time series-based models, including MLP, LSTM, Bi-LSTM, ConvLSTM, ARIMA, and SARIMA. The  
Figure 2: Comparison of feature selection algorithms.  
results indicate that LSTM and ConvLSTM models consistently outperformed other time series models in capturing complex temporal dependencies and accurately forecasting SMP trends. Their ability to integrate both long-term and short-term patterns within the data enabled them to maintain lower error rates, even on dates characterized by significant volatility. ConvLSTM, which combines convolutional and recurrent layers, further demonstrated strong performance on 14 February and 9 August, effectively handling both spatial and temporal relationships in the data.  
In contrast, the ARIMA and SARIMA models, while effective for traditional time series forecasting, showed limitations in handling non-linear and abrupt changes in SMP values. Their moderate to high MAPE values on 30 August and 14 September suggest that these models may not be suitable for complex non-stationary data patterns typically observed in electricity markets.
###### Abstract  
A new Fourier Series Learning Controller (FSLC) for velocity control on a Permanent Magnet Synchronous Motor (PMSM) is proposed and implemented. An analysis of the error convergence for the FSLC is presented, and the update law for the Fourier series coefficients is specified. The field-oriented control method is used as a basic element to implement three different controllers for a PMSM. The performance of the FSLC is compared with two control methods, a classical PI (Proportional Integral) controller and an artificial neural network controller. The periodic nature of torque ripple in PMSMs is considered as a periodic disturbance, which must be compensated by the controller. With the FSLC implementation, a substantial reduction of the velocity ripple is obtained. Furthermore, a higher speed of learning is achieved with the FSLC in comparison with the artificial neural network.  
fourier series; torque ripple; PMSM; learning controller; field-oriented control +
Footnote †: journal: Applied Sciences
# Hybrid Electrostatic-Atomic Accelerometer for Future Space Gravity Missions
### Overview of the Study  
In this article, first we present the numerical simulations conducted to investigate the impact of this hybrid accelerometer for gravity field retrieval [42]. These simulations were carried out in the context of GRACE-type and Bender-type missions where different level of noise specifications of the cold atom accelerometer were considered. In this study, the hybrid accelerometer takes advantage of the long-term stability of the CAI, which is assumed to benefit from a white acceleration noise. The impact of the improved scale factor from which the hybrid instrument benefits is also investigated.  
In a second step, we report some experimental demonstrations of atomic-electrostatic hybridization that have been conducted on the ground, in a lab, with a dedicated electrostatic accelerometer, whose proof-mass plays the role of the reference mirror for a cold atom gravimeter. The possibility to compensate satellite rotation by controlling the electrostatic PM was also investigated experimentally and is here briefly reported.  
Then, we present the numerical modeling of the hybrid accelerometer that was validated by the previously described experimental demonstrations. This simulator would be of great importance to extrapolate the performance of such a hybrid instrument in the context of space missions for which prior ground performance validations are hardly achievable.  
Finally, a preliminary design of a space hybrid instrument is also presented along with the first estimations of the achievable performances, taking into account the detrimental effect of satellite rotation on the atom instrument signal.
## 2 Model and Method
### Turbulence Model  
The components in the ball bearing have a relatively high-velocity difference when rotating at high speed, which will form complex turbulent flows in the bearing. Due to the influence of factors such as large curvature flow and high strain rate inside the bearing, the RNG \(\kappa\)-\(\varepsilon\) turbulence model is adopted [23]. The RNG \(\kappa\)-\(\varepsilon\) turbulence model adapts well to the VOF model. The turbulent kinetic energy and dissipation rate equations are as follows:  
\[\frac{\partial}{\partial t}(\rho k)+\frac{\partial}{\partial x_{i}}(\rho k\mu _{i})=\frac{\partial}{\partial x_{j}}\left[\alpha_{k}\mu_{eff}\frac{\partial k }{\partial x_{j}}\right]+G_{k}-\rho\varepsilon \tag{5}\]  
\[\frac{\partial}{\partial t}(\rho\varepsilon)+\frac{\partial}{\partial x_{i}} (\rho\varepsilon\mu_{i})=\frac{\partial}{\partial x_{j}}\left[\alpha_{k}\mu_ {eff}\frac{\partial\varepsilon}{\partial x_{j}}\right]+C_{1\varepsilon}G_{k} \frac{\varepsilon}{\bar{k}}-\rho C_{2\varepsilon}\frac{\varepsilon^{2}}{k} \tag{6}\]  
Among them:  
\[\mu_{eff}=\mu+\mu_{t} \tag{7}\]  
\[\mu_{t}=\rho C_{\mu}\frac{k^{2}}{\varepsilon} \tag{8}\]  
where \(k\) is turbulent kinetic energy, \(\varepsilon\) is turbulent dissipation, \(\mu_{i}\) is time-averaged velocity, \(G_{k}\) is the generation of turbulent kinetic energy due to mean velocity gradients, \(\mu_{eff}\) is effective dynamic viscosity, \(\mu_{t}\) is turbulent viscosity, \(C_{1\varepsilon}\), and \(C_{2\varepsilon}\) are constant terms.
###### Abstract  
The impacts of pollution and long-term effects of local clam populations are misunderstood in estuaries. The purpose of this study was to follow inorganic contamination in tissues, changes of physiological health indicators, such as condition factor (CF), growth index (GI), resistance in air emersion and dehydration rate, for 5 years in _Mya arenaria_ claims. The sampling scheme comprised one reference site, two sites impacted by human activity (thereafter polluted) and one site recognized as a Saint-Lawrence Estuary (SLE) beluga whale feeding area without known pollution source (Baie Sainte-Marguerite (BSM)). This study revealed that the elemental contamination profiles in claims were increased but differed between the polluted and BSM compared to the reference site. At polluted sites, clams were contaminated by Ag (2.4-fold of reference site), Mn (2.5-fold) and V (6.3-fold). With respect to BSM, clams were mainly contaminated by Ce (2.5-fold), Co (2-fold), Ga (2-fold), La (2.8-fold), Hg (2.5-fold), Ni (2.2-fold), Sm (2-fold) and V (20-fold). This contamination profile suggests sources of pollution from particulate combustion products of gasoline / diesel, crude oil and urban inputs of pollution. The CF, GI and air survival time were all reduced in clams at the polluted sites, while only the CF and dehydration rates were decreased and increased, respectively, at BSM. Long-term analysis revealed that CF and GI tended to decrease over time with episodes of strong amplitude changes and became more resilient to air survival time. In conclusion, the long-term contamination of clams towards metals and elements could compromise the health status of local clam populations. The increased contamination of clams at BSM could represent a risk to the endangered SLE beluga whale population.  
Mya arenaria; condition factor; growth index; air survival; metals; rare earths +
Footnote †: journal: Applied Sciences
# Analysis of the Scalability of UWB Indoor Localization Solutions for High User Densities
## 4 Localization Schemes and MAC Considerations
### MAC Considerations
#### 4.3.3 Hybrid TDMA/FDMA  
Another possibility is to combine multiple techniques. For example, using at the same time TDMA and FDMA, it is possible to have the anchor points working on different non-interfering channels in order to serve simultaneously more users, e.g., the UWB Decawave DW1000 chip can operate in 6 separate channels. Using different preamble codes is also an option to increase diversity.Similarly as in the TDMA-TWR case, the position will be known after ranging with all the four anchors in the cell but the localization process becomes more efficient. This is because multiple users can simultaneously communicate with different anchor points on separate channels without interfering with each other. The gain is proportional to degree of diversity, if the system is using two channels then double \(2\times n_{resources}\) will be available.  
Figure 3: Time Division Multiple Access (TDMA) time division scheme.  
In the TDoA case, however, a combination of two different MAC schemes such as TDMA and FDMA, is not a feasible solution. If there are four anchors on four different channels and one tag is broadcasting a message in one of these four channels, then the message is received by one anchor only and the position cannot be computed. Assuming a single frequency antenna, it would be necessary to deploy extra hardware to overcome this limitation. If the system has to operate on more than one channel, then each anchor node needs to have more than one device, each of them operating on a separate frequency band as every device can operate in a single frequency band at the same time only.
# Recent Advances in Optical Detection of Aminoglycosodies
## 7 Conclusions and Perspectives  
This review summarizes various optical assays, including colorimetric, FL, CL, ECL, SERS, and RRS, for the detection of AGs developed in recent years. Colorimetric assays based on HRP, DNAzyme, and metal NPs were constructed for the detection of AGs. Most AGs do not have fluorophores. Derivative reactions have been employed to generate FL AG derivatives, which can be used to quantitatively detect AGs. For the rapid detection of AGs, FL organic molecules such as Cy3, Cy5, FAM, DNA-binding FL dyes, etc., and FL-emitting nanomaterials have been employed to develop FL assays for AGs using antibodies, aptamers, metal ions, and MIPs as recognition elements. Various well-designed amplification techniques including PCR, RCA, HCR, etc., have been developed to improve the detection sensitivity for AGs. FL assays with aptamers as recognition elements performed well in the quantitative detection of AGs, with both good sensitivity and selectivity. However, FL readouts require a fluorophore. Alternatively, the results of colorimetric assays can be obtained without a specific instrument. For example, colorimetric results can be obtained through naked eye observation or smartphone images with an RGB color analyzer. Thus, the colorimetric assay should be a good choice in the development of on-site detection methods. Further improvements in the detection efficiency, sensitivity, and selectivity are needed to meet the requirement of the on-site detection of trace AGs in complex matrices.  
The authors contributed equally to the manuscript. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
We sincerely thank the support from the Collaborative Innovation Center of Chemical Science and Engineering (Tianjin).  
The authors declare no conflict of interest.