esa-sceva/satcom-chunk-collection huggingface dataset:
## 1 Introduction
However, the study of VIV for composite risers, the late-model risers, are rarely involved. The complexity and design variety of composite risers enhance the difficulty for the study of VIV for composite risers. A global-local analysis methodology was built to investigate the VIV responses of composite riser under semi-empirical fluid load models [31]. [PERSON] and [PERSON] et al. compared the dynamic performance of composite and steel risers using ABQUS and SHEAR7 [32; 33]. These studies normally employed empirical models and no fluid-structure interaction (FSI) was included. The design variety for the composite risers' geometries and the VIV response in every lamina of composite riser were not considered either. In this paper, the VIV responses of three different risers, i.e., conventional steel riser (Riser 1), composite riser with orthogonal reinforcements (Riser 2) and tailored composite riser (Riser 3), are investigated and compared considering the effects of 2D and 3D models and FSI. The simulation of risers' VIV was achieved by ANSYS 17.0 including modules of Geometry, ACP, Transient Structural, Fluid Flow and System Coupling. Effective modulus method (EMM) and layered-structure method (LSM) were built to model composite risers in ACP and Transient Structural and the flow situation is simulated in Fluid Flow (Fluent). System coupling with the data exchange between risers and fluids were utilized to achieve FSI. The VIV responses, such as coefficient of drag (\(C_{D}\)), coefficient of lift (\(C_{L}\)), displacement and stress under VIV, were obtained and compared for all the three risers with different modeling methods.
## 5 Conclusions  
In this paper, we present a novel study of guided light beam reflection and transmission at different waveguide discontinuities and junctions using FFT-based BPM in TE and TM cases. Two remedies are introduced to circumvent the major difficulties that preclude the applicability of the FFT-based BPM in the investigation of TM fields. An equivalent index transforms the TM problem to a TE one, and the step-like index profile of the plasmonic and dielectric guides are smoothed via a sigmoid-like function. This enables full exploitation of the advantage and simplicity that distinguish the traditional split-step FFT-BPM. To the best of the authors' knowledge, this scheme is proposed for the first time. An accurate combined spatial-spectral formalism is included in the FFT-BPM framework to calculate the reflected field at the junction plane between butt-coupled dielectric-plasmonic waveguides. The reflection characteristics of single layer and multilayer coatings at the facet of a dielectric waveguide are also investigated. The results fairly agree with previously published data. We claim that, the method can be extended to other types of interesting problems, like the transverse evanescent coupling between MIM-dielectric and MIM-MIM waveguides. Such coupling could be useful and efficient for nanoscale wavelength filters, ultra-fast optical switching and sensing, as well as graphene-based plasmonic devices.  
A.S. and L.R.G. performed calculations and writing. Y.-C.D. Review and Editing. All authors read and approved the final manuscript.  
This study was partially funded by the Allied Advanced Intelligent Biomedical Research Center (A2 IBRC) under the Higher Education Sprout Project of Ministry of Education.  
The authors would like to thank the support from the National Center for Radiation Research (NCRRT) at Atomic Energy Authority in Egypt.  
The authors declare no conflict of interest.  
Figure 8: The percentage of the transmitted power \(\eta\) compared with reference [27]. As the plasmonic waveguide width \(W_{\rm p}\) increases beyond 42 nm (point of maximum \(\eta\)), the light-collection cross section of the plasmonic guide becomes much higher than the geometrical dimension of the insulating layer, thus \(\eta\) decreases.
# 4D Printing of Multicomponent Shape-Memory Polymer Formulations
###### Abstract  
Four-dimensional (4D) printing technology, as a next-generation additive manufacturing method, enables printed objects to further change their shapes, functionalities, or properties upon exposure to external stimuli. The 4D printing of programmable and deformable materials such as thermo-responsive shape-memory polymers (trSMPs), which possess the ability to change shape by exposure to heat, has attracted particular interest in recent years. Three-dimensional objects based on SMPs have been proposed for various potential applications in different fields, including soft robotics, smart actuators, biomedical and electronics. To enable the manufacturing of complex multifunctional 3D objects, SMPs are often coupled with other functional polymers or fillers during or before the 3D printing process. This review highlights the 4D printing of state-of-the-art multi-component SMP formulations. Commonly used 4D printing technologies such as material extrusion techniques including fused filament fabrication (FFF) and direct ink writing (DIW), as well as vat photopolymerization techniques such as stereolithography (SLA), digital light processing (DLP), and multi-photon polymerization (MPP), are discussed. Different multicomponent SMP systems, their actuation methods, and potential applications of the 3D printed objects are reviewed. Finally, current challenges and prospects for 4D printing technology are summarized.  
4D printing; additive manufacturing; layered structures; multi-material; polymer-based composites; polymer blends; interpenetrated networks; shape memory polymers +
Footnote †: journal: Applied sciences
# Fusion of Bilateral 2 DPCA Information for Image Reconstruction and Recognition
## 5 Results
### Image Reconstruction
The average reconstruction errors of the two unilateral algorithms are much larger than those of DB2 DPCA; this is because 2 DPCA only projects the rows of images onto its projection matrix and A2 DPCA only projects the columns of images onto \begin{table}
\begin{tabular}{l r r r r r} \hline \hline
**Database** & **PCA** & **2 DPCA** & **A2 DPCA** & **(2D)2 PCA** & **BD2 DPCA** \\ \hline Extended Yale B face & 952.2 & 894.4 & 676.2 & 594.5 & **385.8** \\ AR face & 1557.9 & 1056.9 & 1142.0 & 1021.2 & **708.1** \\ Binary Alphadigits & 6.9 & 4.2 & 4.7 & 4.6 & **3.1** \\ PolyU 3D palmprint & 199.7 & 111.0 & 112.9 & 97.9 & **66.2** \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Average reconstruction errors of the five algorithms on four databases. Figure 7: Average reconstruction errors of the five algorithms. (**a**) Extended Yale B face database. (**b**) AR face database. (**c**) Binary Alphadigits database. (**d**) PolyU 3D palmprint databse. its projection matrix. Since the noises in the reconstructed images of 2 DPCA and A2 DPCA exist in different directions, these noises counteract with each other when they are averaged by DB2 DPCA. Therefore, DB2 DPCA has better reconstruction performance than the two unilateral 2D algorithms. The reconstructed images of (2D)\({}^{2}\)PCA are also obscure. The average reconstruction errors of (2D)\({}^{2}\)PCA are much larger than those of DB2 DPCA; this is because (2D)\({}^{2}\)PCA projects the rows and columns of images onto the corresponding projection matrices simultaneously, thus mixing bilateral information together and leading to information loss. DB2 DPCA avoids this problem by averaging between the reconstruction results of the two unilateral algorithms, thus strengthening their similarities and weakening their differences. Therefore, DB2 DPCA achieves better image reconstruction performance than (2D)\({}^{2}\)PCA. The reconstructed images of DB2 DPCA highly approximate the original images, and the average reconstruction errors of DB2 DPCA are the smallest among the five algorithms. Therefore, we conclude that DB2 DPCA outperforms the other four algorithms in image reconstruction. In recent years, \(\ell_{1}\)-norm and \(\ell_{p}\)-norm were introduced to improve 2 DPCA algorithms, proposing new algorithms such as 2 DPCA-L1 [27], 2 DPCAL1-S [30] and G2 DPCA [31]. These algorithms are expected to be more robust to noise and obtain sparse results. However, they only slightly outperform 2 DPCA in image reconstruction even with optimal tuning parameters, especially when the feature number is small. Compared with these algorithms, DB2 DPCA is rather efficacious in image reconstruction.
###### Abstract  
Massive multiple-input multiple-output (massive-MIMO) is foreseen as a potential technology for future 5G cellular communication networks due to its substantial benefits in terms of increased spectral and energy efficiency. These advantages of massive-MIMO are a consequence of equipping the base station (BS) with quite a large number of antenna elements, thus resulting in an aggressive spatial multiplexing. In order to effectively reap the benefits of massive-MIMO, an adequate estimate of the channel impulse response (CIR) between each transmit-receive link is of utmost importance. It has been established in the literature that certain specific multipath propagation environments lead to a sparse structured CIR in spatial and/or delay domains. In this paper, implicit training and compressed sensing based CIR estimation techniques are proposed for the case of massive-MIMO sparse uplink channels. In the proposed superimposed training (SiT) based techniques, a periodic and low power training sequence is superimposed (arithmetically added) over the information sequence, thus avoiding any dedicated time/frequency slots for the training sequence. For the estimation of such massive-MIMO sparse uplink channels, two greedy pursuits based compressed sensing approaches are proposed, viz: SiT based stage-wise orthogonal matching pursuit (SiT-StOMP) and gradient pursuit (SiT-GP). In order to demonstrate the validity of proposed techniques, a performance comparison in terms of normalized mean square error (NCMSE) and bit error rate (BER) is performed with a notable SiT based least squares (SiT-LS) channel estimation technique. The effect of channels' sparsity, training-to-information power ratio (TIR) and signal-to-noise ratio (SNR) on BER and NCMSE performance of proposed schemes is thoroughly studied. For a simulation scenario of: 4 \(\times\) 64 massive-MIMO with a channel sparsity level of 80% and signal-to-noise ratio (SNR) of 10 dB, a performance gain of 18 dB and 13 dB in terms of NCMSE over SiT-LS is observed for the proposed SiT-StOMP and SiT-GP techniques, respectively. Moreover, a performance gain of about 3 dB and 2.5 dB in SNR is achieved by the proposed SiT-StOMP and SiT-GP, respectively, for a BER of \(10^{-2}\), as compared to SiT-LS. This performance gain NCME and BER is observed to further increase with an increase in channels' sparsity.  
massive MIMO; superimposed training; compressed sensing; estimation; sparse channel; 5G communications +
Footnote †: journal: Applied Soft 2017
## 5 Case Studies and Applications  
Nanosensors have found a significant application in real-world bridge monitoring scenarios, revealing insights that have broad implications for structural health monitoring (SHM).  
The application of graphene in creating self-sensing cementitious composites has opened up new frontiers in bridge health monitoring, as evidenced in another case study that explored the capabilities of graphene-infused ultra-high-performance concrete (UHPC) [99]. Graphene, incorporated into the concrete, enhanced its electrical properties while concurrently bolstering its mechanical attributes. This hybrid material, when subjected to stress, modified its electrical properties, thereby enabling a nuanced self-sensing capability under varying load conditions. The material could adeptly detect and report both tension and compression, providing a continuous stream of data that are crucial for assessing the structural integrity of the bridge.  
Finite element simulations played an instrumental role in designing a bridge health monitoring system, adept at recognizing and responding to high-stress conditions inbridge structures. The advantages of using this graphene-based nanosensor are closely tied to its self-sensing capabilities, which not only facilitate continuous monitoring but also significantly contribute towards early detection of potential structural issues, thereby aiding in proactively maintaining and enhancing bridge safety.  
These case studies stand as a testament to the potential and efficacy of nanosensors in structural health monitoring, highlighting not only their capability to provide vital, real-time data on structural health, strain, and deformation but also their pivotal role in enabling early detection and intervention in bridge maintenance scenarios.
# A Sibelobe Suppressing Beamformer for Coherent Plane Wave Compounding
###### Abstract  
Contrast degradation is a critical problem in ultrasound plane wave imaging (PWI) resulting from signals leakage from the sidelobes. An ideal sidelobe reduction method may enhance the contrast without remarkably increasing computational load. To this end, we introduce a new singular value decomposition (SVD) sidelobe reduction beamformer for coherent plane wave compounding (CPWC) based on a previous work. The SVD takes advantage of the benefits of the different features of the mainlobe and sidelobe in terms of spatio-angular coherence and removes the sidelobes before the final coherent summation. This SVD-based method provides a three-dimensional approach (2D in the space and 1D in the angle) while the computation load is kept satisfactory by a dimension-reduced operation before the SVD. To directly observe the sidelobe level, we demonstrate the performance of our SVD method with a point spread function (PSF) simulation. Compared to CPWC, our method shows a 6.2 dB reduction in the peak sidelobe level (PSL). We also applied our method to the anechoic cyst inside the speckle for the imaging contrast. Both in the simulation and phantom studies, our method enhances the contrast-to-noise ratio (CNR) by more than 10%. Therefore, this new beamformer can be an efficient way to suppress sidelobes in PWI.  
sidelobe reduction; beamformer; coherence; singular value decomposition; low complexity
# Pulsed Nanoelectrospray Ionization Boosts Ion Signal in Whole Protein Mass Spectrometry
## 2 Materials and Methods
### Mass Spectrometry  
Most of the mass spectrometry experiments were performed using a linear quadrupole ion trap mass spectrometer (LTQ XL, Thermo Fisher Scientific, San Jose, CA, USA), which is modified with an electrodynamic ion funnel (Heartland Mobility, Wichita, KS, USA). The stainless-steel capillary entrance was heated to 120 \({}^{\circ}\)C. The ion funnel conditions were optimized for a'maximum' ion signal for DC nESI prior to pulsed nESI. Specifically, the RF frequency and 'drive' were tuned between 700-900 kHz and 10-24 a.u. corresponding to a sinusoidal RF waveform of 100-400 V\({}_{\text{p-p}}\). Voltages applied to the MS inlet and the ion funnel electrode were set between 100-250 V. A second LTQ XL with an unmodified ion source (i.e., with the stock capillary-skimmer source) was used for nESI-MS experiments with the protein mixture. Nanoelectrospray ionization emitters were pulled from glass capillaries (1.0 mm o.d.; 0.78 i.d., Harvard Apparatus, UK) to an inner diameter of \(\sim\)250 nm using a Flaming/Brown micropipette puller (Model P-97, Sutter Instrument, Novato, CA, USA). The inner diameters of emitters were confirmed by use of scanning electron microscopy as described elsewhere [34]. The nanoelectrospray emitter was positioned about 2-5 mm from the capillary inlet to the MS. A platinum wire with a diameter of 0.005\" (SDR Scientific, Chatswood, NSW, Australia) was inserted into an uncoated glass capillary filled with \(\sim\)15 \(\upmu\)L of sample solution. A DC voltage of \(\sim\)1.5 kV was applied to the platinum wire relative to the capillary entrance to the MS to initiate and maintain electrospray for conventional nESI-MS experiments. For pulsed nESI, the experiment was performed using the same conditions, except that a pulsed voltage of 0.8 to 1.5 kV was applied to the platinum wire.
# Hot Carrier Photocurrent through MOS Structure
## 4 Conclusions  
Experimental research revealed that pulsed CO2 laser (wavelength 10.6 \(\upmu\)m) causes rise of photocurrent through the metal-oxide-silicon structure when the photon energy is much less than the forbidden energy gap of the semiconductor. In the case of a perfect insulator of the MOS structure, the photocurrent originates from the hot carrier phenomenon and no carrier generation is present. Laser light causes redistribution of carriers at the semiconductor surface. The magnitude of this displacement current is related to the capacitance of the structure and it depends on the rate of the laser pulse change. This effect can be applied to detect fast infrared laser pulses as well as to develop infrared photovaractors. In contrast with most traditional semiconductor detectors working on the basis of interband carrier generation within the long-wavelength infrared region (8-14 \(\upmu\)m atmospheric window), these ones would not require cryogenic cooling since their operation is based on the hot carrier phenomenon.  
In the case of imperfect insulator, the photocurrent through the MOS structure is related to the change of the leakage current.  
Conceptualization, analysis, writing--review and editing, J.G. and S.A.; methodology, investigation, writing--original draft preparation, visualization, J.G.; supervision, project administration, funding acquisition, S.A. All authors have read and agreed to the published version of the manuscript.  
This work was in part supported by the Research Council of Lithuania, grant No. 01.2.2-LMT-K-718-01-0050.  
Not applicable.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
# The Impact of Pitch Error on the Dynamics and Transmission Error of Gear Drives
###### Abstract  
Gear whine noise is governed not only by intentional microgeometry modifications but also by unavoidable pitch (indexing) deviation. This study presents a workflow that couples a tooth-resolved surface scan with a calibrated pitch-deviation table, both imported into a multibody dynamics (MBD) model built in MSC Adams View. Three operating scenarios were evaluated--ideal geometry, measured microgeometry without pitch error, and measured microgeometry with pitch error--at a nominal speed of 1000 r min\({}^{-1}\). Time domain analysis shows that integrating the pitch table increases the mean transmission error (TE) by almost an order of magnitude and introduces a distinct 16.66 Hz shaft order tone. When the measured tooth topologies are added, peak-to-peak TE nearly doubles, revealing a non-linear interaction between spacing deviation and local flank shape. Frequency domain results reproduce the expected mesh-frequency side bands, validating the mapping of the pitch table into the solver. The combined method therefore provides a more faithful digital twin for predicting tonal noise and demonstrates why indexing tolerances must be considered alongside profile relief during gear design optimization.  
transmission error (TE); pitch error; microgeometry; multibody dynamics Article
###### Abstract  
Climate change amplifies the intensity and occurrence of dry periods leading to drought stress in vegetation. For monitoring vegetation stresses, sun-induced chlorophyll fluorescence (SIF) observations are a potential game-changer, as the SIF emission is mechanistically coupled to photosynthetic activity. Yet, the benefit of SIF for drought stress monitoring is not yet understood. This paper analyses the impact of drought stress on canopy-scale SIF emission and surface reflectance over a lettuce and mustard stand with continuous field spectrometer measurements. Here, the SIF measurements are linked to the plant's photosynthetic efficiency, whereas the surface reflectance can be used to monitor the canopy structure. The mustard canopy showed a reduction in the biochemical component of its SIF emission (the fluorescence emission efficiency at 760 nm--e\({}_{760}\)) as a reaction to drought stress, whereas its structural component (the Fluorescence Correction Vegetation Index--FCOVI) barely showed a reaction. The lettuce canopy showed both an increase in the variability of its surface reflectance at a sub-daily scale and a decrease in \(e_{760}\) during a drought stress event. These reactions occurred simultaneously, suggesting that sun-induced chlorophyll fluorescence and reflectance-based indices sensitive to the canopy structure provide complementary information. The intensity of these reactions depend on both the soil water availability and the atmospheric water demand. This paper highlights the potential for SIF from the upcoming FLUorescence EXplorer (FLEX) satellite to provide a unique insight on the plant's water status. At the same time, data on the canopy reflectance with a sub-daily temporal resolution are a promising additional stress indicator for certain species.  
SIF; photosynthesis; photochemical reflectance index; isohydricity; non-photochemical quenching; water limitation; light limitation; soil water availability; vapour pressure deficit; vegetation index +
Footnote †: journal: Remote Sensing  
1
## 3 Results and Discussion
### Effects of Operating Conditions on Reaction Responses  
#### 3.4.1 Main Effect Plots for \(Y_{1}\) and \(Y_{2}\)  
Graphs of the main effects were plotted in order to identify the factor level providing the minimum response value, as shown in Figure 9. Figure 9 presents the mean changes that occurred in both responses (\(Y_{1}\) and \(Y_{2}\)) when the levels of the main factors were changed from the lower level, passing through the central point, to a higher level. The reference line represents the overall mean. A main effect is present when the mean response changes across the levels of a factor. This plot shows that the \(Y_{1}\) and \(Y_{2}\) changes depend on the levels of factor E (phenol concentration) with the steepest line. The steeper the slope of the line, the greater the magnitude of the main effect. Therefore, the concentration of phenol should be studied in detail. It can be seen that for the temperature there were great changes in the mean phenol conversion (\(Y_{1}\)) and hydrogen yield (\(Y_{2}\)), characterized by a great degree of departure from the horizontal (but less than the phenol concentration main effect). Therefore, a higher temperature is desirable to get higher phenol conversion and hydrogen yield. This is because of the favorable hydrocarbon conversion at high temperatures [56]. Feed flow rate and Ni/Co ratio showed slight negative changes in mean \(Y_{1}\) and \(Y_{2}\). \(Y_{1}\) and \(Y_{2}\) decreased from 39.8% and 40.1% to 27.6% and 33.5% with the increase of feed flow rate from 0.16 to 0.46 mL/min, respectively. On the other hand, \(Y_{1}\) and \(Y_{2}\) also decreased from 39.5% and 40.6% to 28.02% and 32.97% with the increase of the Ni to Co ratio from 0 to 1. [PERSON] et al. [52] used Ni\({}_{x}\)Co\({}_{y}\)/Al\({}_{2}\)O\({}_{3}\) catalysts to investigate the activity of glycerin liquid reforming. They noticed that an increase in Co content results in maximum H\({}_{2}\) and minimum CH\({}_{4}\) production. They mentioned that low content of Ni is unfavorable for carbon-carbon breaking. Consequently, the performance of the reforming process was lowered. Hence, it can be concluded that temperature and phenol concentration variables highly influenced \(Y_{1}\) and \(Y_{2}\), whereas feed flow rate, Ni/Co ratio, and catalyst weight had minor effects due to their lines being less sharp against the \(x\)-axis. These patterns were previously identified by statistical significance (Pareto charts and analysis of the regression coefficient data).