Tag: Cross Border

Abstract

Blue holes are part of complex water systems formed by tropical wetlands, karst aquifers, and different coastal environments. In the southeastern Yucatán Peninsula, three submerged blue holes (i.e., Lool ja’, Ch’och-ja’, and Taam-ja’) are located in the shallow tropical estuary of Chetumal Bay. This study examines the morphological features of the three blue holes and explores the seasonal variability of their physicochemical parameters through quarterly field measurements taken between 2021 and 2022. Additionally, this study represents the first documentation of the Lool-ja’ blue hole, which has the largest surface area and volume of the karst structures analyzed. Temperature and salinity profiles along the water column were measured together with surface pH and DO at the blue hole center and within its vicinity (~ 500 m apart). Time series of water temperature, conductivity, and water level were also measured between June and December 2021. Morphological features of the blue holes were explored through georeferenced echo-sounding and 3D-modelling. Seasonal variations were observed on the mixed water layer depth (MLD). During the rainy (dry) season, the surficial mixed water mass became deeper (shallower). Variability in the MLD was proportional to the area occupied by the mouth of the blue hole (r = 0.813). Further homogenized layers accompanied by density interfaces were observed at different depths inside the blue holes. Finally, temperature and salinity diagrams revealed the possible interseasonal exchange of water in the Lool-ja’ and Ch’och-ja’ blue holes with possible intrusion from marine sources.

Abstract

ESA’s Design 2 produces cross-cutting initiative includes digitalisation, process automation, interoperability, and harnessing smart embedded sensors to achieve a seamless data cycle (SDC). The SDC in digital engineering covers requirements and design, production, assembly, integration, and testing as well as in-flight operations including recycling. Nevertheless, central data and legal challenges lie in the joint research addressed Europe-wide (geo-return) and the partner network constraints covering agency, large system integrator (LSI), research and development (R&D), and high-tech SME interests. Either way, a legal enabler for digitization of the European space business can be seen in ESA's strict compliance policy with regard to the acceptance of their general terms and conditions. In fact, it is reasonable to assume that ESA declares data to be a common deliverable in the future and that the contractors accept this too. However, there are technical challenges like portability, interoperability, interconnectivity, and the need for a federated infrastructure, while all these aspects have to be solved across company and national borders. The European Gaia-X project tackles the aforementioned challenges while targeting an open, transparent, and secure digital ecosystem in which data are stored, processed, and used while retaining data sovereignty. This paper deepens these framework conditions, addresses them from the perspective of real space applications, and presents key opportunities and challenges at the implementation level. Moreover, it shows how the seamless data cycle contributes to increase freedom of design, improve overall performance, and reduce cost and lead time from concept to manufacturing while creating new high-performance space products.

Abstract

Hydropneumatic tanks can effectively safeguard pressurized systems from water hammer. In this paper, the influences of the air vessel aspect ratio (R = height/diameter) and its form, whether cylindrical (vertical or horizontal) or spherical, on the transient pressures resulting from abnormal working events of pumps are examined. The primary objectives of this study are to identify the best vessel shape and to determine the optimal value of R while minimizing water hammer effects. The Bentley HAMMER software, which uses the method of characteristics to solve momentum and continuity equations for unsteady flow, is initially verified and subsequently utilized in this analysis. Three case studies are considered. The results show that under the same operating conditions, R insignificantly affects the maximum and minimum pressures. In addition, as R increases, the extreme pressure improves slightly. Furthermore, the hydraulic performances of cylindrical (whether horizontal or vertical) and spherical air vessels under transient conditions at the same volume are identical, and the small differences in the transient results can be attributed to the changing pressures of air/gas inside the vessel resulting from the variations in the cross-sectional area of the vessel.

Abstract

A novel N,N methylene-bis-acrylamide (MBA) crosslinked tamarind gum and β-cyclodextrin graft-poly(methacrylic acid) (TG/β-CG-g-MAA) hydrogel was formulated for colon targeting. The swelling capability, mechanical strength, sol–gel fraction (%), in vitro release and in vivo toxicological screening were estimated experimentally. The effect of polymers, monomer and crosslinker on percentage drug loading, swelling and drug release was determined. TG/β-CD-g-MAA hydrogel was characterized by FTIR, thermal analysis, X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). Swelling was significant at pH 7.4 as compared to pH 1.2. Drug release studies showed that release was significant at pH 7.4 as compared to pH 1.2. Developed hydrogels were porous, thermally stable, offered uniform distribution of amorphous drug and pH-dependent capecitabine release in controlled fashion. Kinetic modelling revealed zero-order drug release and Korsmeyer-Peppas model mechanism of release. Lastly, TG/β-CD-g-MAA hydrogel (F11) can act as prospective pH-responsive carrier for colon targeting.

Graphical abstract

Abstract

The identification of carotid atherosclerotic lesion at risk for plaque rupture, eventually resulting in cerebral embolism and stroke, is of paramount clinical importance. High stress in the fibrous plaque cap has been proposed as risk factor. However, among others, residual strains influence said stress predictions, but quantitative and qualitative implications of residual strains in this context are not well explored. We therefore propose a multiplicative kinematics-based Growth and Remodeling (G&R) framework to predict residual strains from homogenizing tissue stress and then investigate its implication on plaque stress. Carotid vessel morphology of four patients was reconstructed from clinical Computed Tomography-Angiography (CT-A) images and equipped with heterogeneous tissue constitutive properties assigned through a histology-based artificial intelligence image segmentation tool. As compared to a purely elastic analysis and depending on patient-specific morphology and tissue distributions, the incorporation of residual strains reduced the maximum wall stress by up to \(30\%\) and resulted in a fundamentally different distribution of stress across the atherosclerotic wall. Regardless residual strains homogenized tissue stresses, the fibrous plaque cap may persistently be exposed to spots of high stress. In conclusion, the incorporation of residual strains in biomechanical studies of atherosclerotic carotids may be important for a reliable assessment of fibrous plaque cap stress.

Abstract

Sediment yield (SY) is affected by many components, such as topography, climatic phenomena, land use (LU), and soil characteristics, but it is significantly influenced by complicated interactions between climate, LU, and topography. In the current research, InVEST SDR model was utilized to investigate the climate change (CC) and land use change (LUC) contribution to sediment yield effects in a great sub-basin of the Caspian Sea in the north of Iran. Accordingly, five distinct scenarios were extracted and utilized for modeling purposes. The initial two scenarios pertained to the effects of CC, while the third scenario focused on LUC. The final two scenarios involved a combination of both CC and LUC. The results depicted a decreasing and negative impact on SY by CC, while LU had an incremental and positive impact. However, the impact of LUC was more severe comparing to CC. Under scenario 1, compared with the current situation, sediment retention increased by only 0.1%, while sediment exports and total potential soil loss decreased by 0.24% and 0.11%, respectively, but under scenario 2, sediment retention, sediment exports, and total potential soil loss decreased by 19.08%, 19.23%, and 19.25%, respectively. In scenario 3, sediment retention decreased by only 0.78%, while sediment exports and total potential soil loss increased by 22.04% and 21.48%, respectively. Under scenario 4, sediment retention decreased by only 0.76%, but sediment exports and total potential soil loss increased by 22.56% and 21.223%, respectively. Also, under scenario 5, sediment retention, sediment exports, and total potential soil loss decreased by 19.72%, 1.35%, and 1.85%, respectively. The estimation of CC/LUC influence on SY could assist managers and policymakers to have a better comprehension of sediment production processes and help them to manage and control sediment export in watersheds.

Abstract

Sustainable water resource management is a core interest for all societies. As water systems are often common resources, the management of water systems requires coordinated action among actors along the water. For flowing water, a complication for coordination is upstream–downstream relations where what happens upstream affects downstream, but not the other way around. In this study we present results from a survey experiment with politicians in Sweden, focusing on whether and to what extent their willingness to cooperate is affected by their placement upstream or downstream along a fictive water system. Our findings indicate that politicians from upstream and downstream municipalities share the view that upstream politicians bear greater responsibility for undertaking preventive actions and are willing to assume remedial responsibility for problems caused by them. These results challenge the notion that self-interest is the primary obstacle to resolving environmental collective action problems.

Abstract

Introduction

The application of blood flow restriction (BFR) to low-intensity exercise may be able to increase strength not only in the trained limb but also in the homologous untrained limb. Whether this effect is repeatable and how that change compares to that observed with higher intensity exercise is unknown.

Purpose

Examine whether low-intensity training with BFR enhances the cross-education of strength compared to exercise without BFR and maximal efforts.

Methods

A total of 179 participants completed the 6-week study, with 135 individuals performing isometric handgrip training over 18 sessions. Participants were randomly assigned to one of four groups: 1) low-intensity (4 × 2 min of 30% MVC; LI, n = 47), 2) low-intensity with blood flow restriction (LI + 50% arterial occlusion pressure; LI-BFR, n = 41), 3) maximal effort (4 × 5 s of 100% MVC; MAX, n = 47), and 4) non-exercise control (CON, n = 44).

Results

LI-BFR was the only group that observed a cross-education in strength (CON: 0.64 SD 2.9 kg, LI: 0.95 SD 3.6 kg, BFR-LI: 2.7 SD 3.3 kg, MAX: 0.80 SD 3.1 kg). In the trained hand, MAX observed the greatest change in strength (4.8 SD 3.3 kg) followed by LI-BFR (2.8 SD 4.0 kg). LI was not different from CON. Muscle thickness did not change in the untrained arm, but ulna muscle thickness was increased within the trained arm of the LI-BFR group (0.06 SD 0.11 cm).

Conclusion

Incorporating BFR into low-intensity isometric training led to a cross-education effect on strength that was greater than all other groups (including high-intensity training).

Abstract

While internationalising scholarly careers is an imperative in current academia, literature has focused on the impact of such a process at the institutional, national, and international levels. Yet, internationalisation is connected to the personal dimension of careers and, consequently, it might defy academics’ understanding of their working life. The intertwined between well-being and internationalisation in academia is understudied. Using data from qualitative interviews with social science scholars in Mexico, we argue that, seen from the periphery, internationalisation affects personal well-being and job satisfaction both positively and negatively. The challenges of internationalisation for work-life balance depend on the ability of academics to capitalise on their international experiences and their costs. Results indicate that there is no homogeneous positive position with respect to this imperative of academic life today. Hence, if higher education institutions are committed to pursue strategies for internationalisation, they must recognise the personal costs and benefits of this process.