Journal articles on the topic 'Confinement'
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1
Wang, Zhe, Xiaoguang Zhou, and Jili Feng. "An Innovative Method for Conventional Triaxial Tests of Concrete: Applications of PVC Pipes as a Mould and Sealing Membrane." Advances in Civil Engineering 2020 (August 25, 2020): 1–14. http://dx.doi.org/10.1155/2020/4125428.
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In this paper, we propose an innovative method for conventional triaxial tests of concrete with a confining cell. The polyvinyl chloride (PVC) pipe is used as a mould to cast concrete and also as a membrane to isolate the concrete specimen from oil under confinements. This method is termed as PMM (i.e., PVC pipe is used as a mould and membrane). However, a heat-shrink sleeve is used as a membrane in the traditional test method (TMM). Specimens were made from mortar without coarse aggregates in the present experiment. Under six confinements (0–70 MPa), the conventional triaxial compression tests were performed on ultrahigh-strength (150 MPa) and high-strength (82 MPa) mortar specimens by PMM and TMM. The results indicate the following: (i) there is a characteristic confinement p0; when the confinement is lower than p0, the strength by PMM is higher than that by TMM; on the contrary, when the confinement is higher than p0, the strengths by both methods are almost identical. In this work, p0 is between 0 and 5 MPa. (ii) When the confinement is 5–70 MPa, the relationship between the peak stress of high-strength mortar and confinement is characterized by a monotonically rising straight line; however, a monotonically rising upward convex curve describes the peak stress of ultrahigh-strength mortar related to the confinement. (iii) The residual strength using PMM is significantly higher than that using TMM at zero confinement or lower confinements, but the residual strengths by these two methods are approximately identical at higher confinements. (iv) The transverse cracks appear in the mortar specimen inside the PVC pipe after enduring a triaxial loading using PMM. However, there is no such phenomenon when TMM is applied.
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Demuth, Dominik, Melanie Reuhl, Moritz Hopfenmüller, Nail Karabas, Simon Schoner, and Michael Vogel. "Confinement Effects on Glass-Forming Aqueous Dimethyl Sulfoxide Solutions." Molecules 25, no. 18 (September 9, 2020): 4127. http://dx.doi.org/10.3390/molecules25184127.
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Combining broadband dielectric spectroscopy and nuclear magnetic resonance studies, we analyze the reorientation dynamics and the translational diffusion associated with the glassy slowdown of the eutectic aqueous dimethyl sulfoxide solution in nano-sized confinements, explicitly, in silica pores with different diameters and in ficoll and lysozyme matrices at different concentrations. We observe that both rotational and diffusive dynamics are slower and more heterogeneous in the confinements than in the bulk but the degree of these effects depends on the properties of the confinement and differs for the components of the solution. For the hard and the soft matrices, the slowdown and the heterogeneity become more prominent when the size of the confinement is reduced. In addition, the dynamics are more retarded for dimethyl sulfoxide than for water, implying specific guest-host interactions. Moreover, we find that the temperature dependence of the reorientation dynamics and of the translational diffusion differs in severe confinements, indicating a breakdown of the Stokes–Einstein–Debye relation. It is discussed to what extent these confinement effects can be rationalized in the framework of core-shell models, which assume bulk-like and slowed-down motions in central and interfacial confinement regions, respectively.
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Chinappi, M., and E. De Angelis. "Confined dynamics of a single DNA molecule." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 369, no. 1944 (June 13, 2011): 2329–36. http://dx.doi.org/10.1098/rsta.2011.0096.
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The effect of a slit-like confinement on the relaxation dynamics of DNA is studied via a mesoscale model in which a bead and spring model for the polymer is coupled to a particle-based Navier–Stokes solver (multi-particle collision dynamics). The confinement is found to affect the equilibrium stretch of the chain when the bulk gyration radius is comparable to or smaller than the channel height and our data are in agreement with the ( R g,bulk / h ) 1/4 scaling of the polymer extension in the wall tangential direction. Relaxation simulation at different confinements indicates that, while the overall behaviour of the relaxation dynamics is similar for low and strong confinements, a small, but significant, slowing of the far-equilibrium relaxation is found as the confinement increases.
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Ghani, Muhammad Usman, Nauman Ahmad, Kahsay Gebresilassie Abraha, Rana Zafar Abbas Manj, Muhammad Haroon Sharif, and Li Wei. "Review and Assessment of Material, Method, and Predictive Modeling for Fiber-Reinforced Polymer (FRP) Partially Confined Concrete Columns." Polymers 16, no. 10 (May 10, 2024): 1367. http://dx.doi.org/10.3390/polym16101367.
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The repairing and strengthening of concrete structures using external and internal partial confinements are inevitable in the construction industry due to the new standards and rapid developments. The conventional materials and methods of confinement are unable to meet modern safety and functional standards. The fiber-reinforced polymer (FRP) enhances the strength and ductility of deteriorating and new concrete columns by reducing lateral confinement pressure and resistance against seismic shocks. The precise methods of partial confinement are inevitable for effective FRP-concrete bonding, durability, and cost-effectiveness under different loading conditions and to cope with external environmental factors. Predictive modeling and simulation techniques are pivotal for the optimization of confinement materials and methods by investigating the FRP-concrete novel confinement configurations, stress–strain responses, and failure modes. The novel materials and methods for concrete columns’ partial confinement lack high compressive strength, ductility, chemical attack resistivity, and different fiber orientation impacts. This review provides an overview of recent confinement materials, novel methods, and advanced modeling and simulation techniques with a critical analysis of the research gaps for partial FRP confinement of concrete columns. The current challenges and future prospects are also presented.
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Sriboonma, Krissachai, and Sacharuck Pornpeerakeat. "Experimental Investigation of Steel Confinement of Clustered Large-Size Stud Shear Connector in Full-Depth Precast Bridge Deck Panel." Key Engineering Materials 856 (August 2020): 99–105. http://dx.doi.org/10.4028/www.scientific.net/kem.856.99.
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The research focuses on investigating different types of steel confinements around a clustered large-size stud shear connector using in full-depth precast concrete bridge deck panel. The tests were based on Push-off test of two main groups of specimens: (1) the specimens with 4-stud shear connector where three different types of confinement were adopted including of O-ring confinement, Wire-mesh confinement, and L-angle confinement), and (2) the specimens with 8-stud shear connector where two different types of confinement were investigated including of Plate-ring confinement and L-angle confinement. The test results concluded that L-angle confinement type of the group of specimens with 4-Stud is the most sufficient type comparing between the different types of confinement in the same group. The maximum resistance was found at 41-ton, while as the displacement was found to be the most expansible and gradually reduced until the failure point. This means that the sign of failure can be noticeable prior to a collapse of the structure. For the group of specimens with 8-Stud, the resistance of this group was higher than the group of specimens with 4-Stud about 50 - 100% increase depending on each type of confinement. The maximum resistance was found for Plate-ring confinement type at 70-ton, which was agreed with the increment of the displacement about 20 - 50%. In comparison between specimens with 8-Stud, the Plate-ring confinement showed greater resistance and more relative displacement about 15% than the L-angle confinement.
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Rezansoff, T., U. S. Konkankar, and Y. C. Fu. "Confinement limits for tension lap slices under static loading." Canadian Journal of Civil Engineering 19, no. 3 (June 1, 1992): 447–53. http://dx.doi.org/10.1139/l92-054.
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In tension lap splices, the benefit provided to the lap by stirrups placed to intercept longitudinal cracking due to bond splitting action is recognized by the American Concrete Institute code (ACI 318-89) and the design recommendations of ACI Committee 408, on which the American code provisions are partially based. However, a limit exists on the benefit that can be derived from this confinement. In Canada, Canadian Standards Association Standard CAN3 A23.3 M-84 does not directly recognize the confinement benefit provided by stirrups placed along a lap splice. The current study shows that the ACI limit of 1 bar diameter of equivalent concrete cover provided by the transverse reinforcement confinement is too restrictive under static loading. When the concrete cover is small, much larger transverse reinforcement confinement, up to 2-2.5 bar diameters of equivalent concrete cover, can be utilized, in lieu of requiring very long lap lengths. The tests also show that total confinement (actual concrete confinement plus equivalent concrete confinement provided by stirrups) is effective beyond the current limit of 3 main bar diameters, when stirrups are provided. Good performance was found with confinements of 4-4.5 bar diameters, and correspondingly shorter lap splice lengths. Key words: concrete, reinforcement, lap splices, beams, confinement, stirrups, tension, static loading.
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Fang, Ranran, Junchang Li, Jiangen Zheng, Xiaofa Wang, Rui Li, Simin Li, Shiyao Yang, Cheng Li, and Anatoliy Y. Vorobyev. "Spatiotemporal dynamics of water film confinement during spreading and evaporation in highly hierarchical wicking nano/microstructure on Si surface at 120 °C." AIP Advances 13, no. 3 (March 1, 2023): 035209. http://dx.doi.org/10.1063/5.0138916.
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Enhancing the wicking/evaporative functionality of materials by surface nano/microstructuring is a key approach in creating advanced technologies based on the liquid–vapor phase change, particularly in the field of power generation for substantial fuel savings and reducing global greenhouse gas pollution. Despite the technological importance, the capillary flow of a liquid undergoing intensive evaporation on a hot nano/microstructured surface is not well understood. During the capillary flow on a nano/microstructured surface, water confinement undergoes a dramatical spatiotemporal change. The evaporation mechanisms of water confined in capillary nano/microstructures fundamentally depend on the scale of liquid confinement, making the dynamics of water confinement one of the basic characteristics in spreading/evaporation behavior of water on a hot capillary surface. Here, we develop an experimental technique for studying the water film confinement dynamics based on different optical footprints of nanoscale and microscale water confinements found in our work. We study both water film confinement dynamics and traditional capillary flow/receding dynamics of a water drop in a highly hierarchical capillary surface nano/microstructure created in our work using femtosecond laser processing. For the first time, we obtain the spatiotemporal map of water nano/microstructural confinements that provides basic data for the identification of evaporation mechanisms. The obtained results give important guidelines for engineering advanced materials with an efficient wicking/evaporative functionality.
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Pasquetti, Silvia, and Giovanni Picker. "Urban informality and confinement: Toward a relational framework." International Sociology 32, no. 4 (April 21, 2017): 532–44. http://dx.doi.org/10.1177/0268580917701605.
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In the 21st century, a growing number of people live ‘informal’ lives within fissures between legality and informality. Concomitantly, power relations are increasingly expressed through devices of confinement. While urban informality and confinement are on the rise often occurring simultaneously, scholars have so far studied them separately. By contrast, this article proposes a new framework for analysing urban informality and confinement relationally. It generates new insights into the role of informality in the (re)production of confinement and, vice versa, the role of confinement in shaping informal practices. While these insights are valuable for urban studies in general, the article charts new lines of research on urban marginality. It also discusses how the six articles included in this special issue signal the heuristic potential of this relational framework by empirically examining distinct urban configurations of ‘confined informalities’ and ‘informal confinements’ across the Global North and the Global South.
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Okovido, J. O., and C. Kennedy. "Effect of Confining Pressures on the Dynamic Response Characteristics of Niger Delta Clay Soils." Nigerian Journal of Environmental Sciences and Technology 5, no. 2 (October 2021): 377–86. http://dx.doi.org/10.36263/nijest.2021.02.0257.
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The study investigated the earthquake potential in Niger Delta region of Nigeria. A series of resonant column and bender element test was performed on compacted clay soil samples across the investigated Niger Delta States, which showed the influence of confinement on frequency, shear modulus, shear velocity and damping ratio. The confinement in clay was high. The frequency response increases with pressure increase. Also, the resonance column test at various confinements revealed changes in shear modulus, accelerometer output and damping ratio. Thus, there was high variation in the test parameters as confinement pressure was increased. Similarly, the bender element tests also showed that pressure has effect on shear wave-velocity, shear modulus and damping ratio confinement. Although, unlike Resonance Column tests, the shear modulus and shear wave-velocity generally increased as confinement pressure was increased, while for damping ratio it decreases as confinement pressure was increased. The variations in resonance column/binder element test parameters showed that the Niger Delta region, as an oil and gas area, is susceptible to earthquake. Therefore, continuous monitoring of oil exploration activities must be put in place.
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PETER, A. JOHN. "THE EFFECTS OF QUANTUM CONFINEMENT ON THE BINDING ENERGY OF HYDROGENIC IMPURITIES IN A SPHERICAL QUANTUM DOT." Modern Physics Letters B 20, no. 18 (August 10, 2006): 1127–34. http://dx.doi.org/10.1142/s0217984906011487.
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The binding energy of a shallow hydrogenic impurity of a spherical quantum dot confined by harmonic oscillator-like and by rectangular well-like potentials, using a variational procedure within the effective mass approximation, has been determined. The calculations of the binding energy of the donor impurity as a function of the system geometry, and the donor impurity position have been investigated. The binding energy of shallow donor impurity depends not only on the quantum confinements but also on the impurity position. Our results reveal that (i) the donor binding energy decreases as the dot size increases irrespective of the impurity position, and (ii) the binding energy values of rectangular confinement are larger than the values of parabolic confinement and (iii) the rectangular confinement is better than the parabolic confinement in a spherical quantum dot.
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Okovido, J. O., and C. Kennedy. "Effect of Confining Pressures on Dynamic Response Characteristics of Silty Soils in the Niger Delta." Nigerian Journal of Environmental Sciences and Technology 5, no. 2 (October 2021): 404–12. http://dx.doi.org/10.36263/nijest.2021.02.0258.
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The probability of earthquake occurrence in the Niger Delta region of Nigeria was studied in this research. The resonant column/bender element tests were used for the study. Series of analysis were carried out on compacted silt in subsoil strata obtained from various locations in Rivers, Bayelsa, Delta and Akwa Ibom States. The effects of confinement on frequency, shear modulus, shear velocity and damping ratio were studied. The tests results revealed that confinement has effects on the investigated parameters. Thus, frequency response increases with increase in confinement pressure. Also, the resonance column test at various confinements revealed changes in shear modulus, accelerometer output and damping ratio. Accordingly, there was high disparity in the tested parameters as confinement pressure was increased. Similarly, the bender element tests also showed that pressure has effect on shear wave-velocity, shear modulus and damping ratio confinement. The shear modulus and shear wave-velocity generally increased as confinement pressure was increased, while damping ratio decreases as confinement pressure was increased. The variations in Resonance Column/Bender Element test parameters showed that the silty soil in the Niger Delta region, an oil and gas rich area, is likely to experience earthquake in the future. Therefore, geological data should be collated for monitoring, especially as several geological activities take place in the region.
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Jayasri, Gorla, V. Siva Prasad Raju, V. Srinivasa Reddy, and M. Mounika. "Studies on stress- strain behaviour of fibre reinforced self-compacting concrete in confined state." E3S Web of Conferences 309 (2021): 01054. http://dx.doi.org/10.1051/e3sconf/202130901054.
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In the present study, the stress-stain behaviour of self-compacting concrete (SCC) and fibre reinforced self-compacting concrete (FRSCC) were taken up. The stress-strain behaviour was studied for the SCC and FRSCC mixes in unconfined and confined states. The confinement was given in the form of steel hoops in the cylinders, 3 hoops (0.8%), 4 hoops (1.1%), 5 hoops (1.3%) and 6 hoops (1.6%). The addition of fibres along with confinement of FRSCC with steel hoops enhanced the compressive strength, indicating further confinement effect in the FRSCC. It is observed that the addition of fibres is helpful in lower confinements only. Beyond 1.1% confinement, the addition of any type of fibres doesn’t show any effect on compressive strengths. From the stress-strain behaviour of all types of FRSCC, it is concluded that the ultimate load-carrying capacity and strains at peak stresses are more in SFRSCC and HFRSCC for mixes up to 1.1% confinement. The addition of fibres to SCC has increased the ductility in both confined and unconfined states
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Ajay Kumar, K., A. Venkat Sai Krishna, S. Shrihari, and V. Srinivasa Reddy. "Studies on stress-strain behaviour of concrete mixes confined with BFRP rebars." E3S Web of Conferences 309 (2021): 01049. http://dx.doi.org/10.1051/e3sconf/202130901049.
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In the present study, the stress-stain behaviour of confined concrete made with basalt fibre reinforced polymer bars (BFRP) were taken up. The stress-strain behaviour was studied for the concrete mixes confined with steel rebars and BFRP rebars. The confinement was given in the form of steel hoops in the cylinders, 3 hoops (0.8%), 4 hoops (1.1%), 5 hoops (1.3%) and 6 hoops (1.6%). The addition of basalt fibres along with confinement of concrete with steel and BFRP hoops enhanced the compressive strength, indicating further confinement effect in the concrete. It is observed that the addition of fibres is helpful in lower confinements only. Beyond 1.1% confinement, the addition of any type of basalt fibres doesn’t show any effect on compressive strengths. From the stress-strain behaviour of all types of concrete mixes, it is concluded that the ultimate load-carrying capacity and strains at peak stresses are more in concrete with BFRP hoops for mixes up to 1.1% confinement. The addition of basalt fibres to concrete has increased the ductility in both confined and unconfined states
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Kumar, Kakara S. J., M. V. Seshagiri Rao, V. Srinivasa Reddy, and S. Shrihari. "Stress - strain behaviour of confined nano silica-based concrete." E3S Web of Conferences 309 (2021): 01048. http://dx.doi.org/10.1051/e3sconf/202130901048.
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In the present study, the stress-stain behaviour of confined concrete made with nano-silica (nano-SiO2) were taken up. The stress-strain behaviour was studied for the M30 and M50 grades nano-silica (nano-SiO2) concrete mixes confined with steel rebars. The confinement was given in the form of steel hoops in the cylinders, 3 hoops (0.8%), 4 hoops (1.1%), 5 hoops (1.3%) and 6 hoops (1.6%). The addition of nano-silica (nano-SiO2) along with confinement of concrete with steel hoops enhanced the compressive strength, indicating further confinement effect in the concrete. It is observed that the addition of nano-silica (nano-SiO2) is helpful in lower confinements only. Beyond 1.1% confinement, doesn’t show any effect on compressive strengths. From the stress-strain behaviour of all types of concrete mixes, it is concluded that the ultimate load-carrying capacity and strains at peak stresses are more in nano-silica (nano-SiO2) concrete with steel hoops for mixes up to 1.1% confinement. The addition of nano-silica (nano-SiO2) to concrete has increased the ductility in both confined and unconfined states
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Li, Jian Hui, and Chun Xia Miao. "Research on Bond Behavior of Corroded Reinforcing Bar in Concrete Wrapped with Carbon Fiber Reinforced Polymer Sheets." Applied Mechanics and Materials 357-360 (August 2013): 1348–52. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.1348.
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Right evaluation of the bond behavior between corroded reinforcing bar and concrete wrapped with fiber reinforced polymers (FRPs) is a chief problem to confirm the effect of FRP confinement. the pullout tests on 96 test specimens were conducted to study the effect of Carbon FRP (CFRP) confinement on the bond behavior between corroded reinforcing bar and concrete, test variables included reinforcing bar types, concrete covers, degrees of corrosion and CFRP confinements. The test results show that CFRP confinements can make the failure mode of deformed reinforcing bar specimens change from concrete splitting to bar pullout. When the degree of corrosion is less than 5%, the ultimate bond strength of corroded specimens increases by 5%~7%; and the CFRP confinement has less contribution on the ultimate bond strength, but it is effective on slowing down the bond stress descending speed and maintaining the bond strength. When the degree of corrosion is higher than 5%, the ultimate bond strength of corroded specimens drops gradually with the increase of degree of corrosion.
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Cardoso, Francieli L., Jerônimo L. Andriolo, Miriane Dal Picio, Marcieli Piccin, and Jéssica M. Souza. "Nitrogen on growth and yield of lettuce plants grown under root confinement." Horticultura Brasileira 33, no. 4 (December 2015): 422–27. http://dx.doi.org/10.1590/s0102-053620150000400003.
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ABSTRACT: The objective of this research was to test the hypothesis that when lettuce plants grow under root confinement, development and yield is reduced and that such negative effects may be compensated by increasing nitrogen availability in the rooting media. The experiment was conducted between August 11st and September 23rd 2011. Lettuce transplants, cultivar Stella, bearing five leaves, were planted in pots using sand as substrate. Treatments were three root confinement levels and five N concentrations in the nutrient solution, in a 3x5 factorial randomized experimental design with four replications. Root confinements were simulated by pot sizes of 2.5 dm³ (no confinement, the control); 1.0 dm³ (moderate) and 0.4 dm³ (severe). Nitrogen concentrations were: 5.55 (C1), 8.05 (C2), 10.55 (C3), 13.05 (C4) and 15.55 (C5) mmol/L. Interactions were observed between confinement levels and N concentrations. Plants grown under severe root confinement supplied by the nutrient solution at the concentration of 10.55 mmol/L of N reached leaf growth similar to those under no root confinement at 5.55 mmol/L of N. Increasing the N concentration in the nutrient solution enhanced shoot growth but decreased root growth. In lettuce plants grown under root confinement, plant growth is reduced and it is not compensated by increasing N fertilization rates. In both horticultural conventional or soilless production systems, managing practices for stimulate root growth has to be considered to maximize lettuce plant growth and nitrogen use efficiency.
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Sharma, Anshul, Irvine Lian Hao Ong, and Anupam Sengupta. "Time Dependent Lyotropic Chromonic Textures in Microfluidic Confinements." Crystals 11, no. 1 (December 30, 2020): 35. http://dx.doi.org/10.3390/cryst11010035.
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Nematic and columnar phases of lyotropic chromonic liquid crystals (LCLCs) have been long studied for their fundamental and applied prospects in material science and medical diagnostics. LCLC phases represent different self-assembled states of disc-shaped molecules, held together by noncovalent interactions that lead to highly sensitive concentration and temperature dependent properties. Yet, microscale insights into confined LCLCs, specifically in the context of confinement geometry and surface properties, are lacking. Here, we report the emergence of time dependent textures in static disodium cromoglycate (DSCG) solutions, confined in PDMS-based microfluidic devices. We use a combination of soft lithography, surface characterization, and polarized optical imaging to generate and analyze the confinement-induced LCLC textures and demonstrate that over time, herringbone and spherulite textures emerge due to spontaneous nematic (N) to columnar M-phase transition, propagating from the LCLC-PDMS interface into the LCLC bulk. By varying the confinement geometry, anchoring conditions, and the initial DSCG concentration, we can systematically tune the temporal dynamics of the N- to M-phase transition and textural behavior of the confined LCLC. Overall, the time taken to change from nematic to the characteristic M-phase textures decreased as the confinement aspect ratio (width/depth) increased. For a given aspect ratio, the transition to the M-phase was generally faster in degenerate planar confinements, relative to the transition in homeotropic confinements. Since the static molecular states register the initial conditions for LC flows, the time dependent textures reported here suggest that the surface and confinement effects—even under static conditions—could be central in understanding the flow behavior of LCLCs and the associated transport properties of this versatile material.
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Opathalage, Achini, Michael M. Norton, Michael P. N. Juniper, Blake Langeslay, S. Ali Aghvami, Seth Fraden, and Zvonimir Dogic. "Self-organized dynamics and the transition to turbulence of confined active nematics." Proceedings of the National Academy of Sciences 116, no. 11 (February 25, 2019): 4788–97. http://dx.doi.org/10.1073/pnas.1816733116.
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We study how confinement transforms the chaotic dynamics of bulk microtubule-based active nematics into regular spatiotemporal patterns. For weak confinements in disks, multiple continuously nucleating and annihilating topological defects self-organize into persistent circular flows of either handedness. Increasing confinement strength leads to the emergence of distinct dynamics, in which the slow periodic nucleation of topological defects at the boundary is superimposed onto a fast procession of a pair of defects. A defect pair migrates toward the confinement core over multiple rotation cycles, while the associated nematic director field evolves from a distinct double spiral toward a nearly circularly symmetric configuration. The collapse of the defect orbits is punctuated by another boundary-localized nucleation event, that sets up long-term doubly periodic dynamics. Comparing experimental data to a theoretical model of an active nematic reveals that theory captures the fast procession of a pair of +1/2 defects, but not the slow spiral transformation nor the periodic nucleation of defect pairs. Theory also fails to predict the emergence of circular flows in the weak confinement regime. The developed confinement methods are generalized to more complex geometries, providing a robust microfluidic platform for rationally engineering 2D autonomous flows.
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Story, B. "Alone inside: solitary confinement and the ontology of the individual in modern life." Geographica Helvetica 69, no. 5 (December 22, 2014): 355–64. http://dx.doi.org/10.5194/gh-69-355-2014.
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Abstract. The long-term solitary confinement of prisoners causes fundamentally debilitative psychological damage. This violence, inherent to the socio-spatial organization of solitary confinement, diminishes prisoners' capacity to function as human beings. Yet while violence might characterize the ends of solitary confinement, individuation defines the means. This paper argues that solitary confinement, while an extreme case, shares crucial characteristics with other spaces, structures, and modes of organization familiar to Western society. The actual experiences of prisoners subjected to conditions of total isolation, moreover, contradict the prevailing ontology of the individuated subject. The irreconcilability of this paradox invites inquiry into the political and material problematic of individualism itself. The violence of solitary confinement's spatial practice therefore holds important implications for a critical reassessment of any or all socially isolating institutions and individuating ideologies within the structural fabric of modern life.
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Braun, Jens, Holger Gies, and Jan M. Pawlowski. "Quark confinement from colour confinement." Physics Letters B 684, no. 4-5 (February 2010): 262–67. http://dx.doi.org/10.1016/j.physletb.2010.01.009.
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Auger, Nathalie, Antoine Lewin, Émilie Brousseau, Aimina Ayoub, Christine Blaser, and Thuy Mai Luu. "Les confinements et les blessures à vélo : une analyse temporelle des taux de blessures au Québec au cours de la première année de la pandémie." Promotion de la santé et prévention des maladies chroniques au Canada 43, no. 7 (July 2023): 366–74. http://dx.doi.org/10.24095/hpcdp.43.7.03f.
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Introduction Le vélo a gagné en popularité au cours de la pandémie de COVID-19, sans que l’on connaisse l’impact de cette situation sur les blessures chez les cyclistes. Nous avons étudié l’effet des confinements sur les hospitalisations associées à des blessures à vélo. Méthodologie Nous avons relevé les cas d’hospitalisation pour blessure à vélo au Québec (Canada) entre avril 2006 et mars 2021. Nous avons utilisé des rapports de taux (RT) et des intervalles de confiance (IC) à 95 % pour comparer les taux d’hospitalisation par type de blessure subie à vélo et par site anatomique au cours de deux vagues de la pandémie. Nous avons appliqué un modèle de régression de type séries chronologiques interrompues afin d’évaluer l’effet des confinements sur les taux mensuels d’hospitalisation associés aux blessures à vélo, en fonction de l’âge, du sexe et d’autres caractéristiques. Résultats Il y a eu 2 020 hospitalisations pour blessure à vélo entre mars 2020 et mars 2021, dont 617 pendant le premier confinement et 67 pendant le deuxième confinement. Par rapport à la période prépandémique, la plus grande augmentation du risque de blessures liées aux déplacements à vélo pendant le premier confinement a concerné les fractures (RT = 1,44; IC à 95 % : 1,26 à 1,64) et les lésions traumatiques à la tête et au cou (RT = 1,59; IC à 95 % : 1,19 à 2,12). Lors de chaque mois durant le premier confinement, les taux d’hospitalisation pour blessure à vélo ont été considérablement plus élevés qu’en période prépandémique chez les adultes, les adolescents et les personnes vivant dans des quartiers favorisés sur le plan socio-économique ainsi que dans des quartiers à faible densité de population dite racisée. Aucune association avec les blessures à vélo n’a été constatée lors du deuxième confinement. Conclusion Le premier confinement a déclenché une augmentation marquée des hospitalisations pour blessures à vélo, en particulier chez les adultes, les adolescents et les personnes vivant dans des quartiers plus favorisés sur le plan socio-économique et à plus faible densité de population dite racisée.
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Mohammad Hosseini, Mohammad Hosseini, Hassan Kaatuzian Hassan Kaatuzian, and Iman Taghavi Iman Taghavi. "Graded index separate confinement heterostructure transistor laser: analysis of various confinement structures." Chinese Optics Letters 15, no. 6 (2017): 062501. http://dx.doi.org/10.3788/col201715.062501.
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Beaugrand, Matthieu, Christophe Muehlematter, Andjela Markovic, Valérie Camos, and Salome Kurth. "Sleep as a protective factor of children’s executive functions: A study during COVID-19 confinement." PLOS ONE 18, no. 1 (January 11, 2023): e0279034. http://dx.doi.org/10.1371/journal.pone.0279034.
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Confinements due to the COVID-19 outbreak affected sleep and mental health of adults, adolescents and children. Already preschool children experienced acutely worsened sleep, yet the possible resulting effects on executive functions remain unexplored. Longitudinally, sleep quality predicts later behavioral-cognitive outcomes. Accordingly, we propose children’s sleep behavior as essential for healthy cognitive development. By using the COVID-19 confinement as an observational-experimental intervention, we tested whether worsened children’s sleep affects executive functions outcomes 6 months downstream. We hypothesized that acutely increased night awakenings and sleep latency relate to reduced later executive functions. With an online survey during the acute confinement phase we analyzed sleep behavior in 45 children (36–72 months). A first survey referred to the (retrospective) time before and (acute) situation during confinement, and a follow-up survey assessed executive functions 6 months later (6 months retrospectively). Indeed, acutely increased nighttime awakenings related to reduced inhibition at FOLLOW-UP. Associations were specific to the confinement-induced sleep-change and not the sleep behavior before confinement. These findings highlight that specifically acute changes of children’s nighttime sleep during sensitive periods are associated with behavioral outcome consequences. This aligns with observations in animals that inducing poor sleep during developmental periods affects later brain function.
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Gray, Emily. "Decades in Death’s Twilight." New Criminal Law Review 22, no. 2 (2019): 140–63. http://dx.doi.org/10.1525/nclr.2019.22.2.140.
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The average amount of time that death row inmates spend on death row has ballooned over the past decade, and for death row inmates in the state of Texas, the entire duration of that increased time will be spent in solitary confinement. This raises the following question: Is solitary confinement now considered to be part of the punishment, one that may be worse than the death penalty itself? This article discusses the history of solitary confinement in U.S. prisons and cites scientific literature which posits that long-term solitary confinement can cause serious psychological damage. It examines “death row syndrome,” a term that refers to the psychological illness or disorder exhibited by an inmate who has spent a prolonged period of time in harsh conditions on death row. The article reviews the Polunsky Unit, which currently houses Texas’s death row and has been described as one of the worst prisons in the United States. The article also discusses the long history of Lackey claims, which allege that prolonged confinements under a death sentence breach the Eighth Amendment’s prohibition against cruel and unusual punishment. The unresolved dissent within the Supreme Court regarding this subject is presented and discussed. This article contends that the prolonged solitary confinement of a Texas inmate on death row is a violation of the Eighth Amendment, and concludes that the only solution is to end the practice of automatic and permanent solitary confinement.
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Yang, Yu Zhong, and Jian Bin Xin. "The Influences of Lateral Confinement on Ballistic Performance of TiC-TiB2 Composites under the Impact of Long-Rod Kinetic-Energy Projectiles." Advanced Materials Research 391-392 (December 2011): 230–35. http://dx.doi.org/10.4028/www.scientific.net/amr.391-392.230.
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Based on using combustion synthesis under high gravity to prepare TiC-TiB2 composite, the ceramic armour targets were achieved by the heat-shrunk laternal, cover and back confinements of steel sleeves and plates. Ballistic testing showed that under the impact of long-rod tungsten alloy projectile, the low-carbon-steel sleeve failed to laterally confine the ceramic due to its inadequate residual strength, resulting in poor ballistic performance of the ceramic, whereas the medium-carbon-steel sleeve had a sufficient residual strength to support lateral confinement of the ceramic as the long-rod tungsten alloy projectile makes room in the ceramic for its penetration, the confined ceramic could present its real ballistic performance, and the results of ballistic testing promised lateral confinement and cover confinement of high-strength metal would be beneficial to the improvement in ballistic performance of ceramic armour.
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Bohanek, Vječislav, Muhamed Sućeska, Mario Dobrilović, and Philipp Hartlieb. "Effect of Confinement on Detonation Velocity and Plate Dent Test Results for ANFO Explosive." Energies 15, no. 12 (June 16, 2022): 4404. http://dx.doi.org/10.3390/en15124404.
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The detonation properties of nonideal explosives are highly dependent on charge diameter and existence and properties of confinement. In this study, the effect of different confinements on the detonation velocity of ANFO explosives was experimentally determined along with the results of the plate dent test. ANFO explosive was selected as one of the most commonly used nonideal explosives. Following the measurement results, we found that the detonation velocity increased with increasing wall thickness, and the velocity increase was different for different confinement materials. A strong correlation existed between the ratio of the mass of confiner and explosive (M/C) and the detonation velocity (R = 0.995), and between (M/C) and the depth of the dent (δ) (R = 0.975). The data presented in this paper represent preliminary findings in developing a confinement model required for reliable numerical modeling of nonideal explosives.
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Li, Ming, and Jizeng Wang. "Stretching Wormlike Chains in Narrow Tubes of Arbitrary Cross-Sections." Polymers 11, no. 12 (December 10, 2019): 2050. http://dx.doi.org/10.3390/polym11122050.
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We considered the stretching of semiflexible polymer chains confined in narrow tubes with arbitrary cross-sections. Based on the wormlike chain model and technique of normal mode decomposition in statistical physics, we derived a compact analytical expression on the force-confinement-extension relation of the chains. This single formula was generalized to be valid for tube confinements with arbitrary cross-sections. In addition, we extended the generalized bead-rod model for Brownian dynamics simulations of confined polymer chains subjected to force stretching, so that the confinement effects to the chains applied by the tubes with arbitrary cross-sections can be quantitatively taken into account through numerical simulations. Extensive simulation examples on the wormlike chains confined in tubes of various shapes quantitatively justified the theoretically derived generalized formula on the force-confinement-extension relation of the chains.
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Zhao, Zhong Min, Long Zhang, Yi Gang Song, and Xue Gang Huang. "Lateral Confinement and Ballistic Performance of TiC-TiB2 Composites." Key Engineering Materials 492 (September 2011): 126–31. http://dx.doi.org/10.4028/www.scientific.net/kem.492.126.
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Based on using combustion synthesis under high gravity to prepare TiC-TiB2 composite, the ceramic armour targets were achieved by the heat-shrunk lateral, cover and back confinements of steel sleeves and plates. Ballistic testing showed that under the impact of long-rod tungsten alloy projectile, the low-carbon-steel sleeve failed to laterally confine the ceramic due to its inadequate residual strength, resulting in poor ballistic performance of the ceramic, whereas the medium-carbon-steel sleeve had a sufficient residual strength to support lateral confinement of the ceramic as the long-rod tungsten alloy projectile makes room in the ceramic for its penetration, the confined ceramic could present its real ballistic performance, and the results of ballistic testing promised lateral confinement and cover confinement of high-strength metal would be beneficial to the improvement in ballistic performance of ceramic armour.
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Cayla, Olivier. "Confinement." Grief N° 7/2, no. 2 (July 28, 2020): 11–12. http://dx.doi.org/10.3917/grief.202.0009.
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Salthun-Lassalle, Bénédicte. "Confinement." Cerveau & Psycho N° 121, no. 5 (May 17, 2020): 6–7. http://dx.doi.org/10.3917/cerpsy.121.0006.
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Touré, Ali. "Confinement." La Revue Nouvelle N° 8, no. 8 (January 16, 2023): 88. http://dx.doi.org/10.3917/rn.228.0088.
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Alatshan, Faesal, Siti Aminah Osman, Fidelis Mashiri, and Roszilah Hamid. "Explicit Simulation of Circular CFST Stub Columns with External Steel Confinement under Axial Compression." Materials 13, no. 1 (December 19, 2019): 23. http://dx.doi.org/10.3390/ma13010023.
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Concrete-filled steel tube (CFST) structural members have been widely used in engineering projects for their superior strength and ductility. However, the different lateral dilation characteristics between concrete infill and steel tube have caused imperfect composite interaction during the early loading stage. To overcome this issue, external steel confinements in the form of rings and spiral were previously suggested to minimise the lateral expansion of the steel tube and enhance the concrete confinement effects. This study presented the analytical behaviour of circular CFST short columns with an external ring or spiral confinements which are subjected to axial loading. An explicit finite element (FE) model was developed and verified based on previous experimental findings. Besides that, this study analysed the failure modes, axial load–strain relationship, stress distributions, and bond strength of the composite column components. Parametric analysis was also undertaken to evaluate the impact of material strengths, total steel ratio, and diameter-to-thickness ratio. The results suggest that the use of external steel confinement can enhance the compressive behaviour of CFSTs better than increasing the thickness of the steel tube when using the same steel ratio. Finally, simplified design formulations were developed to accurately calculate the ultimate capacity of CFST columns with and without external steel confinement.
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Chen, Wenduo, Xiangxin Kong, Qianqian Wei, Huaiyu Chen, Jiayin Liu, and Dazhi Jiang. "Compression and Stretching of Confined Linear and Ring Polymers by Applying Force." Polymers 13, no. 23 (November 30, 2021): 4193. http://dx.doi.org/10.3390/polym13234193.
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We use Langevin dynamics to study the deformations of linear and ring polymers in different confinements by applying compression and stretching forces on their two sides. Our results show that the compression deformations are the results of an interplay among of polymer rigidity, degree of confinement, and force applied. When the applied force is beyond the threshold required for the buckling transition, the semiflexible chain under the strong confinement firstly buckles; then comes helical deformation. However, under the same force loading, the semiflexible chain under the weaker confinement exhibits buckling instability and shrinks from the folded ends/sides until it becomes three-folded structures. This happens because the strong confinement not only strongly reduces the buckling wavelength, but also increases the critical buckling force threshold. For the weakly confined polymers, in compression process, the flexible linear polymer collapses into condensed states under a small external force, whereas the ring polymer only shows slight shrinkage, due to the excluded volume interactions of two strands in the crowded states. These results are essential for understanding the deformations of the ring biomacromolecules and polymer chains in mechanical compression or driven transport.
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Herrera-Velarde, Salvador, Edith C. Euán-Díaz, and Ramón Castañeda-Priego. "Ordering and Dynamics of Interacting Colloidal Particles under Soft Confinement." Colloids and Interfaces 5, no. 2 (May 17, 2021): 29. http://dx.doi.org/10.3390/colloids5020029.
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Confinement can induce substantial changes in the physical properties of macromolecules in suspension. Soft confinement is a particular class of restriction where the boundaries that constraint the particles in a region of the space are not well-defined. This scenario leads to a broader structural and dynamical behavior than observed in systems enclosed between rigid walls. In this contribution, we study the ordering and diffusive properties of a two-dimensional colloidal model system subjected to a one-dimensional parabolic trap. Increasing the trap strength makes it possible to go through weak to strong confinement, allowing a dimensional transition from two- to one-dimension. The non-monotonic response of the static and dynamical properties to the gradual dimensionality change affects the system phase behavior. We find that the particle dynamics are connected to the structural transitions induced by the parabolic trap. In particular, at low and intermediate confinement regimes, complex structural and dynamical scenarios arise, where the softness of the external potential induces melting and freezing, resulting in faster and slower particle diffusion, respectively. Besides, at strong confinements, colloids move basically along one direction, and the whole system behaves structurally and dynamically similar to a one-dimensional colloidal system.
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Liu, Haihu, Yan Ba, Lei Wu, Zhen Li, Guang Xi, and Yonghao Zhang. "A hybrid lattice Boltzmann and finite difference method for droplet dynamics with insoluble surfactants." Journal of Fluid Mechanics 837 (December 21, 2017): 381–412. http://dx.doi.org/10.1017/jfm.2017.859.
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Droplet dynamics in microfluidic applications is significantly influenced by surfactants. It remains a research challenge to model and simulate droplet behaviour including deformation, breakup and coalescence, especially in the confined microfluidic environment. Here, we propose a hybrid method to simulate interfacial flows with insoluble surfactants. The immiscible two-phase flow is solved by an improved lattice Boltzmann colour-gradient model which incorporates a Marangoni stress resulting from non-uniform interfacial tension, while the convection–diffusion equation which describes the evolution of surfactant concentration in the entire fluid domain is solved by a finite difference method. The lattice Boltzmann and finite difference simulations are coupled through an equation of state, which describes how surfactant concentration influences interfacial tension. Our method is first validated for the surfactant-laden droplet deformation in a three-dimensional (3D) extensional flow and a 2D shear flow, and then applied to investigate the effect of surfactants on droplet dynamics in a 3D shear flow. Numerical results show that, at low capillary numbers, surfactants increase droplet deformation, due to reduced interfacial tension by the average surfactant concentration, and non-uniform effects from non-uniform capillary pressure and Marangoni stresses. The role of surfactants on the critical capillary number ($Ca_{cr}$) of droplet breakup is investigated for various confinements (defined as the ratio of droplet diameter to wall separation) and Reynolds numbers. For clean droplets,$Ca_{cr}$first decreases and then increases with confinement, and the minimum value of$Ca_{cr}$is reached at a confinement of 0.5; for surfactant-laden droplets,$Ca_{cr}$exhibits the same variation in trend for confinements lower than 0.7, but, for higher confinements,$Ca_{cr}$is almost a constant. The presence of surfactants decreases$Ca_{cr}$for each confinement, and the decrease is also attributed to the reduction in average interfacial tension and non-uniform effects, which are found to prevent droplet breakup at low confinements but promote breakup at high confinements. In either clean or surfactant-laden cases,$Ca_{cr}$first remains almost unchanged and then decreases with increasing Reynolds number, and a higher confinement or Reynolds number favours ternary breakup. Finally, we study the collision of two equal-sized droplets in a shear flow in both surfactant-free and surfactant-contaminated systems with the same effective capillary numbers. It is identified that the non-uniform effects in the near-contact interfacial region immobilize the interfaces when two droplets are approaching each other and thus inhibit their coalescence.
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Meglis, I. L., P. M. Melanson, and I. J. Jordaan. "Microstructural change in ice: II. Creep behavior under triaxial stress conditions." Journal of Glaciology 45, no. 151 (1999): 438–48. http://dx.doi.org/10.3189/s0022143000001295.
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AbstractThis work investigates the deformation of ice under deviatoric stresses and confining pressures expected during ice–structure interaction. Granular ice was tested under a range of confining pressures (5–60 MPa) and deviatoric stresses (up to 25 MPa), with sample temperatures between –8° and –10°C. Samples were deformed to increasing end-levels of axial strain, and were thin-sectioned and photographed immediately following testing.At all confinement levels, the original texture of the sample is completely transformed within the first 10–15% strain, to a fine-grained matrix with a few larger, isolated grains. At low confinements, grain-size reduction is associated with extensive microcracking. At high confinements, few cracks are observed. Observations suggest that microcracking, melting and recrystallization are active at all levels of confinement, though the relative importance of each depends on the confinement, stress and accumulated strain.Deviatoric stress is a strong factor in controlling the creep, reflected in both the time required for the sample to reach accelerated creep and the tertiary creep rate itself. Two exceptions to this pattern were noted. First, some samples experienced strain localization and eventual rupture. These specimens tended to have higher creep rates even in the initial stages of strain. Second, prior damage resulted in rapid softening compared with the behavior of undamaged specimens. However, when strain rates are compared among all samples at a given level of cumulative axial strain, the creep behavior obeys a power law over the whole range of strain levels tested. Effective viscosity decreased from 107.8 to l06.4 MPa−n s within the first 10% strain, during which the most substantial microstructural changes occurred, and then stayed relatively stable. The stress exponent, n, remained within the range 4.0–4.6.The dominant deformation mechanism appears to depend strongly on confining pressure (cracking at low pressure and dynamic recrystallization at high pressure). Creep rates at high confinement appear to increase relative to those at intermediate confinement, but the influence of temperature must be addressed further.
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Meglis, I. L., P. M. Melanson, and I. J. Jordaan. "Microstructural change in ice: II. Creep behavior under triaxial stress conditions." Journal of Glaciology 45, no. 151 (1999): 438–48. http://dx.doi.org/10.1017/s0022143000001295.
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AbstractThis work investigates the deformation of ice under deviatoric stresses and confining pressures expected during ice–structure interaction. Granular ice was tested under a range of confining pressures (5–60 MPa) and deviatoric stresses (up to 25 MPa), with sample temperatures between –8° and –10°C. Samples were deformed to increasing end-levels of axial strain, and were thin-sectioned and photographed immediately following testing.At all confinement levels, the original texture of the sample is completely transformed within the first 10–15% strain, to a fine-grained matrix with a few larger, isolated grains. At low confinements, grain-size reduction is associated with extensive microcracking. At high confinements, few cracks are observed. Observations suggest that microcracking, melting and recrystallization are active at all levels of confinement, though the relative importance of each depends on the confinement, stress and accumulated strain.Deviatoric stress is a strong factor in controlling the creep, reflected in both the time required for the sample to reach accelerated creep and the tertiary creep rate itself. Two exceptions to this pattern were noted. First, some samples experienced strain localization and eventual rupture. These specimens tended to have higher creep ratesevenin the initial stages of strain. Second, prior damage resulted in rapid softening compared with the behavior of undamaged specimens. However, when strain rates are compared among all samples at a given level of cumulative axial strain, the creep behavior obeys a power law over the whole range of strain levels tested. Effective viscosity decreased from 107.8to l06.4MPa−ns within the first 10% strain, during which the most substantial microstructural changes occurred, and then stayed relatively stable. The stress exponent,n, remained within the range 4.0–4.6.The dominant deformation mechanism appears to depend strongly on confining pressure (cracking at low pressure and dynamic recrystallization at high pressure). Creep rates at high confinement appear to increase relative to those at intermediate confinement, but the influence of temperature must be addressed further.
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Rezansoff, T., and B. F. Sparling. "Correlation of the bond provisions of CSA A23.3-94 with tests on tension lap splices in beams." Canadian Journal of Civil Engineering 22, no. 4 (August 1, 1995): 755–69. http://dx.doi.org/10.1139/l95-086.
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Data on beams with tension lap splices tested under static loading at the same institution over the past two decades are correlated with the bond provisions of the Canadian concrete standard CAN/CSA A23.3-94 (detailed design approach), as well as with the recommendations of ACI Committee 408, on which the Canadian standard appears to be largely based. The correlations show that transverse reinforcement is more effective than the new bond provisions allowed in cases where the bond failure is governed by splitting rather than bar pullout. Extending the effective limits for confinement provides a more accurate estimate of the bond resistance available at higher levels of confinement, resulting in a more uniform factor of safety over a wide range of confinements. Lap splices with no transverse confinement showed relatively poorer performance than lap splices with varying degrees of transverse confinement when correlated with resistances predicted on the basis of the new CAN/CSA A23.3-94 provisions. Weaker relative splice performance in the absence of transverse confinement raises a concern for the development lengths required by the CAN/CSA A23.3-94 provisions. With highly stressed lap splices, a class factor of 1.3 is applied to the basic development length to determine the lap length. Published information, on the other hand, has shown that lap splice lengths and development lengths should be the same for transferring or developing the same level of stress in tension reinforcement when the same level of confinement is provided along the anchorage. In contrast, the ACI Committee 408 recommendations use a larger factor of safety on development length and lap splice length, rather than applying class factors for splices only, making splice and development lengths the same for the same confinement and required strength transfer. For the data considered, required lap lengths are similar using both the CSA Standard CAN/CSA A23.3-94 (including the 1.3 class factor) and the ACI 408 recommendations, and only small differences in overall prediction accuracy were found. Differences in the definition of the concrete confinement term for close bar spacing by the two design models, different limits on the total confinement that can be considered effective, as well as a further modification factor for bar size in the CAN/CSA A23.3-94 provisions, result in only small differences in lap length requirements for most of the data considered. Key words: anchorage (structural), bond, confinement, lap splices, reinforced concrete, standards, static loading, tension.
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Sahu, Anupam, and Dharmendra Kumar. "Effect of Confinement Strength on the Conversion Efficiency of Strained Core-Shell Quantum Dot Solar Cell-=SUP=-*-=/SUP=-." Журнал технической физики 128, no. 10 (2020): 1534. http://dx.doi.org/10.21883/os.2020.10.50027.1026-20.
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In this paper, the conversion efficiency (CE) of core-shell quantum dot (CSQD) solar cell is investigated within weak and strong confinements strength, using detailed balance model. The weak and strong confinement strength in solar cell structure is modeled using ZnTe/ZnSe and PbS/CdS CSQD, respectively. Considering size-dependent strain results of CE of CSQD solar cell for varying core radius is plotted with and without considering multiple exciton generation (MEG), and the results show the improvement in CE with MEG, thus indicating its importance in the low-dimensional system. The numerical results demonstrate that for the same CSQD size, the solar cell with a stronger confinement strength achieves the higher CE in comparison to the weaker confinement. Also, the MEG significantly increases the CE of stronger confined CSQD solar cell. The results plotted are in good agreement with the literature. Keywords: conversion efficiency, quantum dot, core-shell, solar cell, multiple exciton generation.
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Barfety-Servignat, Véronique, Anne Bera-Louville, Céline Taylor, Véronique Delêtre, Thibaud Liegeard, and Antoine Bioy. "Douleur et retentissement psychologique en période Covid-19 : deux enquêtes sur un an de pandémie Covid-19 en France." Perspectives Psy 62, no. 1 (January 2023): 73–83. http://dx.doi.org/10.1051/ppsy/2023621073.
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Nous avons étudié le retentissement psychologique des confinements à partir des réponses d’une étude réalisée en deux phases sur une année dans une population de patients douloureux chroniques. Ce travail montre l’impact en termes de majoration importante des douleurs, des troubles de l’humeur et des conduites instinctuelles dans les populations de patients douloureux chroniques. Pour la moitié des répondants, l’expérience de confinement a produit angoisse, troubles de l’humeur et du sommeil, fatigue. Les liens entre durée prolongée du confinement et risque accru de troubles anxio-dépressifs témoignent également de la nécessité d’être vigilant à cette symptomatologie dans les cas de re-confinement, même lorsqu’ils sont partiels. Dans ces espaces de restriction, les psychologues auront sans doute à mettre en travail le rapport au corps, à mobiliser la résistance vitale individuelle chez les patients et dans les équipes de soins – puisque nous partageons cette même expérience – et chercher à mobiliser les capacités d’imagination et de rêverie individuelle et collective.
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Demuth, Dominik, Matthias Sattig, Elisa Steinrücken, Max Weigler, and Michael Vogel. "2H NMR Studies on the Dynamics of Pure and Mixed Hydrogen-Bonded Liquids in Confinement." Zeitschrift für Physikalische Chemie 232, no. 7-8 (July 26, 2018): 1059–87. http://dx.doi.org/10.1515/zpch-2017-1027.
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Abstract2H NMR is used to ascertain dynamical behaviors of pure and mixed hydrogen-bonded liquids in bulk and in confinement. Detailed comparisons of previous and new results in broad dynamic and temperature ranges reveal that confinement effects differ for various liquids and confinements. For water, molecular reorientation strongly depends on the confinement size, with much slower and less fragile structural relaxation under more severe geometrical restriction. Moreover, a dynamical crossover occurs when a fraction of solid water forms so that the dynamics of the fraction of liquid water becomes even more restricted and, as a consequence, changes from bulk-like to interface-dominated. For glycerol, by contrast, confinement has weak effects on the reorientation dynamics. Mixed hydrogen-bonded liquids show even more complex dynamical behaviors. For aqueous solutions, the temperature dependence of the structural relaxation becomes discontinuous when the concentration changes due to a freezing of water fractions. This tendency for partial crystallization is enhanced rather than reduced by confinement, because different liquid-matrix interactions of the molecular species induce micro-phase segregation, which facilitates ice formation in water-rich regions. In addition, dynamical couplings at solvent-protein interfaces are discussed. It is shown that, on the one hand, solvent dynamics are substantially slowed down at protein surfaces and, on the other hand, protein dynamics significantly depend on the composition and, thus, the viscosity of the solvent. Furthermore, a protein dynamical transition occurs when the amplitude of water-coupled restricted backbone dynamics vanishes upon cooling.
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Issifu, Adamu, and Francisco A. Brito. "Confinement of Fermions in Tachyon Matter." Advances in High Energy Physics 2020 (April 25, 2020): 1–18. http://dx.doi.org/10.1155/2020/1852841.
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In this paper, we develop a phenomenological model inspired by QCD that mimics the QCD theory. We use the gauge theory in color dielectric medium (Gϕ) coupled with fermion fields to produce scalar and vector confinements in the chromoelectric flux tube scenario. The Abelian theory will be used to approximate the non-Abelian QCD theory in a consistent manner. We will calculate vector and scalar glueballs and compare the result to the existing simulation and experimental results and projections. The QCD-like vacuum associated with the model will be calculated and its behavior studied relative to changing quark masses. We will also comment on the relationship between tachyon condensation, dual Higgs mechanism, QCD monopole condensation, and their association with confinement. The behavior of the QCD string tension obtained from the vector potential of the model will be studied to establish vector dominance in confinement theories.
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Pasquet, Guy-Noël. "Enfance du confinement et confinement de l’enfance." Le sociographe N°71, no. 3 (2020): 4. http://dx.doi.org/10.3917/graph.071.0004.
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Lin, Shao-Zhen, Dapeng Bi, Bo Li, and Xi-Qiao Feng. "Dynamic instability and migration modes of collective cells in channels." Journal of The Royal Society Interface 16, no. 156 (July 2019): 20190258. http://dx.doi.org/10.1098/rsif.2019.0258.
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Migrating cells constantly experience geometrical confinements in vivo , as exemplified by cancer invasion and embryo development. In this paper, we investigate how intrinsic cellular properties and extrinsic channel confinements jointly regulate the two-dimensional migratory dynamics of collective cells. We find that besides external confinement, active cell motility and cell crowdedness also shape the migration modes of collective cells. Furthermore, the effects of active cell motility, cell crowdedness and confinement size on collective cell migration can be integrated into a unified dimensionless parameter, defined as the cellular motility number (CMN), which mirrors the competition between active motile force and passive elastic restoring force of cells. A low CMN favours laminar-like cell flows, while a high CMN destabilizes cell motions, resulting in a series of mode transitions from a laminar phase to an ordered vortex chain, and further to a mesoscale turbulent phase. These findings not only explain recent experiments but also predict dynamic behaviours of cell collectives, such as the existence of an ordered vortex chain mode and the mode selection under non-straight confinements, which are experimentally testable across different epithelial cell lines.
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Martínez-Patiño, María José, Francisco Javier Blas Lopez, Michel Dubois, Eric Vilain, and Juan Pedro Fuentes-García. "Effects of COVID-19 Home Confinement on Behavior, Perception of Threat, Stress and Training Patterns of Olympic and Paralympic Athletes." International Journal of Environmental Research and Public Health 18, no. 23 (December 3, 2021): 12780. http://dx.doi.org/10.3390/ijerph182312780.
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Background: The aims of this study were to analyze the effects of the COVID-19 pandemic and its subsequent confinement on behaviors, perception of threat, stress, state of mind and training patterns among Olympic and Paralympic level athletes. Methods: Data gathering was performed utilizing an online questionnaire during imposed confinement. A correlational design with incidental sampling for convenience was used. All the variables were analyzed by age, gender, academic training, type of participation and sport specialty on a population composed of 447 Olympic (age: 26.0 ± 7.5 years) and 64 Paralympic (age: 28.4 ± 10.5 years) athletes. Results: The athletes trained more than twice as many hours before than during confinement. Most of the athletes recognized that their best athletic performance diminished due to the COVID-19 confinement but that will recover after the pandemic and its confinements. Almost half of the athletes declared they were more tired than normal and had difficulty sleeping, while more than half ate more or less as usual. Paralympic athletes reported they felt more capable to cope with personal problems and life events and felt less lonely during the confinement than the Olympians. The athletes from team sports reported to be more affected in their training routine than athletes of individual sports, seeing their athletic performance more affected. Athletes in individual sports felt more able to cope with personal problems than athletes in team sports. Female athletes were significantly more tired and reported more difficulty sleeping than male athletes. Conclusion: The situation caused by COVID-19 has had significant effects on the behavior, perception of threat, stress and training patterns of Olympic and Paralympic athletes preparing for the 2020 Tokyo Olympics. It is necessary that sports institutions reinforce mechanisms of help for athletes during future situations of confinement.
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Joseph, Lakshmi, Mini K. Madhavan, Karingamanna Jayanarayanan, and Alessandro Pegoretti. "Evaluation of Hybrid Fiber Multiscale Polymer Composites for Structural Confinement under Cyclic Axial Compressive Loading." Journal of Composites Science 7, no. 4 (April 9, 2023): 152. http://dx.doi.org/10.3390/jcs7040152.
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Fiber reinforced polymer (FRP) confinement is recognized as the most promising technique for the strengthening and retrofitting of concrete structures. In order to enhance the performance of conventional epoxy-based FRP composites, nano filler modification of the epoxy matrix was implemented in the current study. In particular, the cyclic loading response of standard concrete specimens externally confined by epoxy-based natural and hybrid fiber reinforced polymer systems was investigated. The confinements were realized with sisal fiber reinforced polymer (SFRP) and hybrid sisal basalt fiber reinforced polymer (HSBFRP). Moreover, the effects of multiwalled carbon nanotubes (MWCNT) were also investigated. Three different specimen sets were considered for study: (i) unconfined specimens, (ii) epoxy-based FRP confined specimens and (iii) MWCNT incorporated epoxy-based FRP confined specimens. The specimens were tested in repeated compressive mode in loading-unloading cycles at increasing displacement levels. The test results revealed that FRP wrapping could enhance the mechanical behavior of unconfined columns in terms of strength and ductility. Moreover, it was evident that the mechanical properties of the epoxy matrix were enhanced by MWCNT incorporation. The developed epoxy-based FRP confinement containing MWCNT ensures improvement in axial strength by 71% when compared with unconfined specimens. The epoxy-based FRP confinement, with and without MWCNT, exhibited a high strain redistribution behavior around the concrete core. In comparison to the unconfined specimens, the confinement could increase the sustained axial strain from 0.6 to 1.4% using epoxy-based FRP confinement and to 1.6% with MWCNT incorporated epoxy-based FRP confinement. Further, an empirical model was developed to predict the ultimate axial stress of concrete columns confined externally with FRP jackets. The ultimate compressive strength obtained from the experimental study was compared with the proposed model, and the observed deviation was lower than 1%.
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Clavero, Cristina, and Berta Ausin. "Psychological effects of lockdown due to the Covid-19 pandemic in the year 2020: A systematic review." Behavioral Psychology/Psicología Conductual 30, no. 2 (September 9, 2022): 565–95. http://dx.doi.org/10.51668/bp.8322214s.
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The aim was to systematically review studies on the psychological impact of confinement by Covid-19 on the general Spanish population and health professionals in the first year of the pandemic. The review includes the 18 studies published between January and December 2020. Findings indicate that the psychological impact increases as confinement progresses, with percentages of affectation ranging from 3-30% in anxiety symptoms (37-72% in healthcare professionals), 6-57% in depressive symptoms (27-61% in healthcare professionals), 2-40% in symptoms of stress (14-47% in healthcare professionals), 15-20% in symptoms associated with post-traumatic stress (15.8% in healthcare professionals), 12-53% in sleep problems (29% in healthcare professionals), and 9-37% in feelings of loneliness. The groups at risk identified are women, young people, the unemployed and people with previous mental health problems. The Covid-19 has had important repercussions on the mental health of the general Spanish population and health professionals, and it is necessary to establish assessment and intervention protocols that allow the detection and intervention on the affected population after confinement and during future confinements.
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Simonov, Yurii A. "The confinement." Uspekhi Fizicheskih Nauk 166, no. 4 (1996): 337–62. http://dx.doi.org/10.3367/ufnr.0166.199604a.0337.
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García-del-Castillo, José A., Irene Ramos-Soler, and Fernando García-Castillo. "Confinement Behavior." Journal of Psychology and Psychotherapy Research 8 (2021): 37–47. http://dx.doi.org/10.12974/2313-1047.2021.08.5.
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Paris, Yago. "Escaping Confinement." Interactive Film and Media Journal 2, no. 1 (January 30, 2022): 32–47. http://dx.doi.org/10.32920/ifmj.v2i1.1512.
Full textAbstract:
One of the most representative aspects of fiction films that address the COVID-19 pandemic is the insistent appearance of electronic devices (laptops, tablets, smartphones) to allow virtual communication between the main characters of the story. I claim that, in those films, the use of these devices and the images they produce is different from those that appeared in pre-pandemic cinema, and, as such, conveys different meanings to the filmed images. In order to explore these ideas, I will first study the ontology of phone footage imagery, to establish the main traits of this type of image. Afterwards, I will signal the differences between pre-pandemic and pandemic phone footage imagery, in order to understand the key formal traits that imply different meanings for each case. Finally, by analyzing some of the most relevant commercial films about the COVID-19 pandemic that have been produced so far (Songbird (2020), Locked Down (2021), Safer at Home (2021), Host (2020), and Ctrl+Alt+Trick/treat (2020)), I will intend to prove that in these fictions phone footage (as opposed to other electronic-device footage) addresses the desire to gain certain freedom in a scenario of confinement.