esa-sceva/satcom-chunk-collection huggingface dataset:
# Buckling Test of Composite Cylindrical Shells with Large Radius Thickness Ratio
## 1 Introduction  
The scatter and deviation of the buckling load between theory and experiment have been studied since the 1960s, but the cause of the scatter and deviation has yet to be revealed. One potential cause is thought to be shape imperfection. Studies using a nonlinear finite element analysis, including of the measured shape imperfection, have given 5-10% larger results than the experimental buckling loads [1]. The method, however, cannot be used for prediction, because it requires the manufacturing of a cylinder and measurement of the shape imperfection. Regression analyses have further shown that various factors, including layup overlaps or gaps, the radius-to-thickness ratio (\(r/t\)), the length-to-radius ratio (\(L/r\)) [2], layup stiffness, and oval shape imperfection, are not statistically significant [3]. The authors investigated the effect of axisymmetric shape imperfections on the ratio of the experimental buckling load and theoretical buckling load, which is called the knockdown factor (KDF), and found that it increases with the amplitude of drum-typeshape imperfections [4]. The investigation was conducted on nine cylinders; however, they were of the same radius \(r=75\) mm, and their \(r/t\) values were similar, i.e., from 460 to 670. On the other hand, many metal cylinders were investigated over a wide range of \(r/t\) (the data summarized in Reference [5]), and it was found that the KDF decreased with the increasing \(r/t\)[6], as shown in Figure 1.  
Composite cylinders, however, show a constant relation between the KDF and \(r/t\) in a narrow range of \(r/t\)[7] (as shown later). Recently, several studies for the KDF of cylinders have been published; however, there was no study for a composite cylinder with the range of a \(r/t\) over 670 [8; 9; 10; 11; 12; 13; 14]. [PERSON] et al. [8] investigated the KDF of metal cylinders with single boundary perturbation approach. [PERSON] and [PERSON]'s [9] discussion about that led to new, improved knockdown factors for the design of cylindrical metal shells under axial compression. [PERSON] and [PERSON] [10] investigated the relationship between geometric imperfection and the KDF. [PERSON] et al. [11] presented a numerical design approach based on the reduced stiffness method for the buckling of shell structures. Although a lot of effort has gone into developing novel manufacturing and the production of composites [15; 16; 17; 18], there has been no investigation into the KDF of composite tubes. Thus, the aim of the current study was to investigate the KDF over a large range of a \(r/t\) through buckling tests with \(r=100\) mm, \(t=0.112\) mm, and \(r/t=893\). Moreover, the effect of the shape imperfections was measured before and after the buckling tests, and the relationship between the shape imperfections and the KDF was investigated.
## 3 Results
### Textile WW Treatment Performance Using SD Technology Laboratory Setup  
To investigate the efficiency of the SD technology in WW treatment, the textile effluent quality indicators were measured at different feeding WW flowrates--namely, 10, 15, 20, 25, and 30 L/h--and different disc rotational speeds--specifically 100, 250, 400, 550, 850, 1200, and 1500 rpm.  
Some values of the measured textile WW quality indicators--i.e., color (A\({}_{456}\)); suspended solids (SS); absorbance at 525 nm (A\({}_{525}\)) and 620 nm (A\({}_{620}\))- at three different disc rotational speed values of 100, 300, and 500 rpm, all at the same WW flowrate of 10 L/h--are represented in Figure 2a-c. All the graphs indicate decreasing trends, larger or smaller, depending on the rotational speed of the disc that demonstrates the spinning disc technology's effectiveness.  
Additionally, the same variation in the time of quality indicators at a WW flowrate of 30 L/h at three different disc rotational speeds of 100, 300, and 500 rpm presented in Figure 3a-c indicates similar decreasing trends.  
Based on the variation in time of the WW quality indicators, the removal efficiency, calculated using Equation (1), has been determined and graphically represented to establish, on the one hand, the most advantageous working parameters--namely, the WW flowrate and the disc rotational speed--for which the maximum removal values are performed and, on the other hand, to prove the efficiency of  
Figure 2: Variation in the time of the textile WW suspended solids (MS) and colour at 10 L/h flowrate and three different rotational speeds: (**a**) 100 rpm, (**b**) 300 rpm, (**c**) 500 rpm.  
the SD technology. Following the influence of the WW flowrate at constant disc rotational speeds and also the influence of the disc rotational speed at constant WW flowrates on the color and suspended solids removal, these quality indicators are discussed in the following subsections.  
It is worth mentioning that, after the application of the SD technology to the studied textile wastewater, only very low changes in pH (no more than \(\pm\)0.5 units) and temperature (no more than \(\pm\)4 \({}^{\circ}\)C) took place; thus, one can conclude that no significant changes in the treated WW pH and temperature by SD technology at room temperature and the usual collected textile WW pH are obtained.
## 2 Materials and Methods
### Gait Analysis and sEMG Activity  
The kinematic analysis of gait was performed using the SMART Motion Capture System (BTS, by Bioengineering, Milano, Italy) equipped with 4-optoelectronic cameras able to perform a 3D reconstruction of the trajectories, provided by reflective markers placed on the body according to a previous protocol [13; 64; 65]. Specifically, the markers were placed on the anterior superior iliac spines, greater trochanters, lateral femoral condyles, calcaneus, lateral malleoli, and fifth metatarsal. The cameras were calibrated in static and dynamic modality by determining the shooting volume around the treadmill; data were collected with a sampling rate of 60 Hz. The participant walked on a treadmill for 60 s at each selected speed (1, 2, and 3 km/h). The participant walked without plantar orthosis and the gait pattern was determined by hip-knee and knee-ankle angle cyclograms [13; 64; 66; 67]. The data of three angles, plotted by the sagittal motion plane over time, were considered in the analysis of the lower limbs using the SMART Analyser (BTS, Bioengineering). The absolute hip angle is formed by the thigh axis and the vertical hip passing through the pelvis, the relative knee angle is formed by the extension of the thigh axis and the shank axis, while the relative ankle angle is formed by the shank axis and axis through the foot. The angle-angle diagrams were drawn by interpolating five points representative of the gait cycle: toe off (TO), maximum knee flexion (MKF), maximum hip flexion (MHF), foot support (FS), and maximum flexion of the knee during the contact phase (MKF-C) [66]. For TO and FS, the frames considered corresponded to those in which the value of the X vector of velocity changed from negative to positive and vice versa [68]. AutoCAD 2023 (Autodesk, San Rafael, CA, USA) enabled us to calculate the area and the perimeters of the angle-angle diagrams, as reported in previous studies [13; 64; 65]. The shape of the loops formed by the angle-angle diagrams was calculated by dividing the perimeter by the square root of the area (\(Perimeter/\sqrt{Area}\)) [69]. The kinematic data were synchronized with the wireless sEMG system (MuscleLab 6000, Ergotest-innovation, Porsgrunn, Norway), recording the muscle activity of the VL, BF, TA, and LG. The sEMG\({}_{\text{RMS}}\) considered a full wave (Figure 3) of stance phase in two consecutive steps (extrapolated in the central part of the recording) for the weakest and strongest leg. The peak sEMG\({}_{\text{RMS}}\) value of the respective muscle during the stance phase of walking was used to normalize the sEMG\({}_{\text{RMS}}\) signals of the muscles during walking [70].
## 6 Conclusions and Perspectives  
A new compact lightweight spectrometer (1.8 kg) called AMUISE has been developed based on near-infrared laser technology and an open-path multipass cell. The spectrometer is dedicated to measurement of the vertical profiles of carbon dioxide in the atmosphere up to 10 km under meteorological and stratospheric balloons. We have demonstrated during the campaign high precision of 0.96 ppm for 1-s integration time (1o), i.e., high temporal and spatial resolution (\(\sim\)1 Hz and 5 m). This instrument is autonomous, easy to use in a strap plug and play mode and is highly robust. Hence, the instrument was launched 17 times and was successfully recovered without any damage. The pre-localization prediction of Meteo--France allowed prepositioning on the recovery site after each flight so a 100% instrument recovery rate was achieved.  
The instrument optimization is underway and the newer version of the AMUISE will allow a simultaneous measurement of CH\({}_{4}\) and CO\({}_{2}\) up to 35 km altitude. This new dual-gas version of AMUISE will still complies with the light weights (\(<\)2.5 kg) required to be operated with weather balloons. It will furthermore feature real time onboard concentration retrieval. The preliminary results are promising with a precision of 0.3 ppm instead of 0.96 ppm in 1-s integration time for the CO\({}_{2}\) channel based on 3 hours' time series measurement and the Allan variance study (laboratory work). Several stratospheric flights are already programmed with this new version of AMUISE in Kiruna--Sweden (September 2016) and in Aire sur l'Adour--France (Fall 2016) with the CNES (Centre National d'Etudes Spatiales--Paris, France).
# The State of Ethereum Smart Contracts Security: Vulnerabilities, Countermeasures, and Tool Support
## 4 Smart-Contracts Vulnerabilities and Countermeasures
### Vulnerabilities and Countermeasures
#### 4.2.8 Mismdled Exceptions  
In Solidity, the require, assert, try/catch could be utilized to verify all kinds of information to ensure that the smart contract behaves as it is designed to. However, some low-level functions such as address.send(), call(), delegatcall(), staticcall() find another way when an error comes up. Normally, when an exception is found, the transactions are reverted and gas is consumed, but if low-level functions encounter errors (e.g., the call stack is depleted), they will return a false value without any exceptions. Any transactions executed before those functions will not be reverted, and gas is spent. In other words, when using low-level functions, a false return value should be noted and properly handled; otherwise, the security of the smart contract will be affected.  
_Countermeasures_. As suggested by Solidity Documentation [83], low-level functions should not be used whenever possible. The transfer function can be used to transfer Ether to other accounts. If those low-level functions must be used, it is better to check every return value of those functions and handle the false ones.
# D-Limonene: Promising and Sustainable Natural Bioactive Compound
## 4 Antimicrobial Mechanism of D-Limonene
### Antibiofilm Mechanism of D-Limonene  
#### 4.2.1 The Effects of D-Limonene on EPS Secretion and Gene Regulation  
Curli is recognized as a key factor in biofilm formation and D-limonene concentrations at 12.5 \(\mu\)L/mL and 25 \(\mu\)L/mL inhibited _E. coli_ biofilm formation by 55% and 92%, respectively, EPS production was reduced by 35% and 60%, and no curli were observed after 25 \(\mu\)L/mL D-limonene treatment, which is probably due to inhibition of the transcription of _E. coli_ curli production genes (_csgA_, _csgB_, _csgC_, and _csgD_) [74]. The MIC of D-limonene against _C. albicans_ was reported to be 300 \(\mu\)g/mL, at which concentration the secretion of proteinases and phospholipases, adhesion ability, and biofilm formation were significantly reduced by 73%, 53%, 91%, and 87%, respectively, and, furthermore, a good docking score was obtained in the molecular docking analysis with virulence-associated proteins (Plb1 and Tec1), indicating that D-limonene may inhibit the adhesion ability, biofilm-forming ability, and morphological transition of _Candida_ by associating with key _Candida_ pathogenicity proteins [84].
## 5 Conclusions  
Hypercrosslinked porous materials, in particular hypercrosslinked polystyrene, HPS, are already widely used in a variety of industrial processes, mainly as excellent adsorbents. Considerable knowledge has been also accumulated on their application as support for heterogeneous catalysts, including the processes of biomass processing and transformations of platform compounds. Platform chemicals, also known as chemical building blocks, are substances that serve as starting materials for the synthesis of various value-added products. The volume of platform chemicals derived from biomass is constantly growing due to the demand of sustainability for chemical industry.  
This review focused on the recent advances in this field, giving several examples of the use of catalysts based on nanoparticles of catalytically active metals stabilized by a polymer matrix of HPS. The main advantages of HPS-based catalysts could be summarized as following: (1) large specific surface area with macro-, meso-, and microporosity;(2) chemical and thermal stability; (3) the possibility of functionalization for controlling surface hydrophobicity and interaction with metal precursors; (4) the possibility of synthesizing catalytic composites with magnetic properties for easy separation and reuse; (5) the ability to control morphology of active nano-particles; and (6) low cost of the HPS supports, which increases economic feasibility of the processes under development.  
At the same time, some problems are associated with the HPS as catalytic support. Drawbacks include: (1) difficult access of big reagent molecules into the small pores of the catalyst; (2) the absence of surface acid sites, which are important for some reactions, like hydrolysis; (3) a special attention is required to the nature of the active phase precursor (due to its interaction with the hydrophobic polymer); and (4) the limited temperature regime (below 300 \({}^{\circ}\)C), which could be applied during catalyst synthesis and chemical reactions. These challenges need to be overcome to extend the industrial applications of HPS-based catalysts for novel processes of biomass transformations into platform chemicals.  
Conceptualization, O.M., O.K., L.N. and V.M.; formal analysis, O.M., A.B. and M.S.; investigation, O.M., O.K., L.N. and V.M.; resources, O.M., O.K., L.N. and V.M.; data curation, O.M., A.B. and M.S.; writing--original draft preparation, O.M., L.K.-M., M.G., L.N., V.M. and O.K.; writing--review and editing, O.M. and L.K.-M.; visualization, O.M. and A.B.; supervision, L.K.-M.; project administration, V.M. and M.S.; and funding acquisition, V.M. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Russian Science Foundation, grant number 23-79-00009.  
The authors declare no conflict of interest.
## 4 Discussion
### Results Discussion
In the decreasing displacement range, the non-throwing arm provides the stability center for the throwing arm to circle around it as it accelerates in velocity. Indeed, the non-throwing arm played a pivot point or fulcrum for the upper trunk and the throwing arm to rotate around. The stable fulcrum provided by the non-throwing arm enhances the thrower's postural control, which is crucial for optimal force transfer, as described in the kinetic chain theory [30]. Therefore, decreasing the velocity of the non-throwing arm's joints is significant for the throwing side; it ensures higher torque on the throwing arm. Additionally, it helps decelerate the resultant velocity while the throwing arm accelerates. Faster displacement of throwing arm is produced by larger torque. Several studies have shown the shoulder of the non-throwing arm roughly unchanged position while the throwing arm displaces around it in other throwing movements [15, 31]. Therefore, the shoulder of the non-throwing arm plays an important role like the pivot point or fulcrum for the trunk and throwing arm rotating. Hence, the non-throwing arm acts as a pivot point, stabilizing the upper body and enabling the throwing arm to generate higher torques efficiently. In summary, the decreasing velocity of the non-throwing arm provides a more stable fulcrum and controls the motion of the throwing side, which can contribute to higher performance. Based on these observations, we can summarize the function of the non-throwing arm into two main components: firstly, with increasing shoulder velocity, the non-throwing arm introduces displacement regarding the center of mass; secondly, with decreasing velocity, the non-throwing arm serves as a stable pivot for trunk and arm rotation. These findings highlight the complex and nuanced role of the non-throwing arm in shot put performance, suggesting that it is not merely a passive component but plays an active role in throw mechanics. Moreover, our results underscore the critical role of the non-throwing arm, suggesting that coaches and athletes should pay more attention to its mechanics. Specifically, training programs should incorporate exercises that enhance the coordination and timing of the non-throwing arm movement. For instance, drills focusing on the synchronization of both arms during practice can improve overall performance. Coaches may consider implementing targeted strength and conditioning exercises that focus on the muscles involved in the non-throwing arm, aiming to increase its effectiveness as a stabilizing component in the throwing motion. Additionally, video analysis and biomechanical feedback can be beneficial for athletes to visualize and refine their non-throwing arm mechanics during training sessions. By closely examining the movement patterns, athletes can make real-time adjustments, ultimately enhancing their throwing technique.
# Performance Estimate of a Spin-Stabilized Drag Sail for Spacecraft Deorbiting
## Abbreviations  
The following abbreviations are used in this manuscript:  
\begin{tabular}{l l} ECI & Earth-centered inertial \\ LEO & low Earth orbit \\ MEOE & modified equinoctial orbital element \\ RTN & radial-tangential-normal \\ SRP & solar radiation pressure \\ SSO & Sun-synchronous orbit \\
**Nomenclature** & \\ \(\mathbb{A}\) & state dynamical matrix, see Equation (4) \\ \(A\) & drag sail area [m\({}^{2}\)] \\ \(a\) & osculating orbit semimajor axis [km] \\ \(\mathbf{a}_{P}\) & perturbative acceleration vector [km/s\({}^{2}\)] \\ \(\mathbf{b}\) & auxiliary vector, see Equation (5) \\ \(C_{D}\) & drag coefficient, see Equation (11) \\ \(C_{L}\) & lift coefficient, see Equation (12) \\ \(c_{r}\) & reflection coefficient \\ \(\mathfrak{D}\) & set of atmospheric density values, see Equation (22) \\ \(e\) & osculating orbit eccentricity \\ \(G\) & Earth's center of mass \\ \(J_{2}\) & Earth's second zonal harmonics \\ \(i\) & osculating orbit inclination [deg] \\ \(\{\mathbf{i},\mathbf{j},\mathbf{k}\}\) & ECI frame unit vectors \\ \(\{\hat{t}_{R},\hat{t}_{T},\hat{t}_{N}\}\) & RTN frame unit vectors \\ \(\mathbf{L}\) & lift unit vector, see Equation (10) \\ \(\ell\) & Sun-Earth distance [au] \\ \(m\) & spacecraft total mass [kg] \\ \(N\) & number of density evaluations \\ \(\mathbf{\hat{n}}\) & unit vector normal to the sail \\ \(\mathbf{\hat{n}_{\text{SRP}}}\) & normal unit vector associated with SRP perturbation, see Equation (15) \\ \(O\) & spacecraft center of mass \\ \(P_{\oplus}\) & solar radiation pressure at 1 au from the Sun [Pa] \\ \(\{p,\,f,\,g,\,h,\,k,\,L\}\) & modified equinoctial orbital elements of the osculating orbit \\ \(\mathbb{R}\) & rotational matrix from ECI frame to RTN frame \\ \(R_{\oplus}\) & Earth's equatorial radius [km] \\ \(\mathbf{r}\) & Earth-spacecraft vector [km] \\ \(r\) & Earth-spacecraft distance [km] \\ \(\mathcal{G}\) & set of time instants, see Equation (21) \\ \(\mathbf{\hat{s}}\) & Sun-spacecraft unit vector \\ \(\mathcal{T}_{\text{ECI}}\) & Earth-centered inertial frame \\ \(\mathcal{T}_{\text{RTN}}\) & radial-tangential-normal frame \\ \(T\) & osculating orbit period [hours] \\ \(t\) & time instant [days] \\ \(u\) & osculating orbit argument of latitude [deg] \\ \(V_{R}\) & ratio of particle thermal velocity to orbital velocity \\ \(\mathbf{v}\) & spacecraft orbital velocity vector [km/s] \\ \(\mathbf{x}\) & state vector \\ \(\eta\) & eclipse parameter \\ \(\mu_{\oplus}\) & Earth's gravitational parameter [km\({}^{3}\)/s\({}^{2}\)] \\ \(\
u\) & spacecraft true anomaly on the osculating orbit [deg] \\ \(\rho\) & atmospheric density, [kg/m\({}^{3}\)] \\ \(\sigma_{N}\) & normal momentum accommodation coefficient \\ \(\sigma_{T}\) & tangential momentum accommodation coefficient \\ \(\Omega\) & osculating orbit right ascension of the ascending node [deg] \\ \(\omega\) & osculating orbit argument of pericenter [deg] \\ \end{tabular}
## 2 Understanding Pediatric Fracture Overgrowth
### Mechanisms of Fracture Overgrowth  
The mechanisms behind fracture overgrowth are not fully understood, but several theories have been proposed:  
Hyperemia Theory: Following a fracture, increased blood flow (hyperemia) to the injury site facilitates healing. This increased vascularity may extend to the adjacent growth plate (physis), stimulating it to produce more cartilage cells that later ossify, thus accelerating longitudinal bone growth [13]. Hyperemia not only aids in fracture healing but may also inadvertently enhance growth plate activity.  
Mechanical Environment: Immobilization of the fractured limb reduces mechanical stress on the growth plate, potentially altering the normal inhibitory signals that regulate growth plate activity and leading to an increase in growth rate [14; 15]. Changes in muscle forces due to immobilization or altered weight-bearing can also impact growth plate stimulation.  
Biological Factors: The fracture healing process involves a complex cascade of biological events, including the release of growth factors and cytokines. Molecules such as insulin-like growth factor-1 (IGF-1), bone morphogenetic proteins ( BMPs), and vascular endothelial growth factor (VEGF) play crucial roles in bone repair and regeneration [13]. These factors may have systemic effects, enhancing growth plate activity beyond the immediate vicinity of the fracture.  
Neurovascular Mechanisms: Injury to nerves and blood vessels during a fracture could disrupt normal growth regulation. Neurovascular mechanisms influence bone growth, and damage to these systems may lead to altered signaling at the growth plate, promoting overgrowth [16].  
Genetic Factors: Emerging research suggests that genetic factors may also play a role. Variations in genes that regulate growth plate activity, bone healing, and response to injury could make some children more susceptible to overgrowth [17]. Understanding these genetic influences could lead to the identification of biomarkers for risk assessment [18].