Journal articles on the topic 'Static concentrating'
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Muhammad-Sukki, Firdaus, Haroon Farooq, Siti Hawa Abu-Bakar, Jorge Alfredo Ardila-Rey, Nazmi Sellami, Ciaran Kilpatrick, Mohd Nabil Muhtazaruddin, Nurul Aini Bani, and Muhammad Zulkipli. "Mathematical Modelling of a Static Concentrating Photovoltaic: Simulation and Experimental Validation." Applied Sciences 11, no. 9 (April 25, 2021): 3894. http://dx.doi.org/10.3390/app11093894.
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For the past twenty years, there has been increasing interest and investment in solar photovoltaic (PV) technology. One particular area of interest is the development of concentrating PV (CPV), especially for use in building integration. Many CPV designs have been developed and investigated. This paper aims at producing a mathematical modelling using MATLAB programme to predict the current-voltage (I-V) and power-voltage (P-V) characteristics of a static CPV. The MATLAB programme could also simulate the angular response of the CPV designs-which has never been explored in the previous literature. In this paper, a CPV known as the rotationally asymmetrical dielectric totally internally reflecting concentrator (RADTIRC) was analysed. A specific RADTIRC design that has an acceptance angle of ±40° was investigated in this paper. A mathematical modelling was used to simulate the angular characteristics of the RADTIRC from −50° to 50° with an increment 5°. For any CPV, we propose that the value of opto-electronic gain, Copto-e needs to be included in the mathematical model, which were obtained from experiments. The range of incident angle (±50°) was selected to demonstrate that the RADTIRC is capable of capturing the sun rays within its acceptance angle of ±40°. In each simulation, the I-V and P-V characteristics were produced, and the short circuit current (Isc), the open-circuit voltage (Voc), the maximum power (Pmax), the fill factor (FF) and the opto-electronic gain (Copto-e) were determined and recorded. The results from the simulations were validated via experiments. It was found that the simulation model is able to predict the I-V and P-V characteristics of the RADTIRC as well as its angular response, with the highest error recorded for the Isc, Voc, Pmax, FF and Copto-e was 2.1229%, 5.3913%, 9.9681%, 4.4231% and 0.0000% respectively when compared with the experiment.
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Sellami, Nazmi, and Tapas K. Mallick. "Optical characterisation and optimisation of a static Window Integrated Concentrating Photovoltaic system." Solar Energy 91 (May 2013): 273–82. http://dx.doi.org/10.1016/j.solener.2013.02.012.
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Treece, Graham, Joel Lindop, Lujie Chen, James Housden, Richard Prager, and Andrew Gee. "Real-time quasi-static ultrasound elastography." Interface Focus 1, no. 4 (April 20, 2011): 540–52. http://dx.doi.org/10.1098/rsfs.2011.0011.
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Ultrasound elastography is a technique used for clinical imaging of tissue stiffness with a conventional ultrasound machine. It was first proposed two decades ago, but active research continues in this area to the present day. Numerous clinical applications have been investigated, mostly related to cancer imaging, and though these have yet to prove conclusive, the technique has seen increasing commercial and clinical interest. This paper presents a review of the most widely adopted, non-quantitative, techniques focusing on technical innovations rather than clinical applications. The review is not intended to be exhaustive, concentrating instead on placing the various techniques in context according to the authors' perspective of the field.
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Schultis, Brian. "Life, Movement, and Thought: Directions for Performance Philosophy and Practice as Research." Performance Philosophy 4, no. 2 (February 1, 2019): 332–44. http://dx.doi.org/10.21476/pp.2019.42231.
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This essay addresses the common goals of but also the practical differences between the emerging fields of Performance Philosophy (PP) and Practice as Research (PaR). It does so by describing them both as interposing effective and affective action into the process of thinking and knowing, thereby resisting what Gilles Deleuze calls the Dogmatic Image of Thought. The dogmatic image is described as a directional movement based on Plato’s allegory of the cave, where those who would learn turn away from phenomenal becoming and move upward and outward towards eternal Truth. This movement travels from a static unknowing to a static knowledge. Both PP and PaR resist such movement by employing techniques which forestall arriving at either stasis. Through their developments, PP and PaR have come to concentrate on resisting one of these points of stasis or the other – with PP concentrating on avoiding static knowing, and PaR concentrating on finding the proper expression to avoid static unknowing, even while presenting its findings in forms that may appear ephemeral.
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Denisov, I. S., V. V. Korotkov, and D. S. Smirnov. "Gaschromatographic monitoring of volatile pollutants of urban air: optimizing analysis and concentrating." Sanitarnyj vrač (Sanitary Doctor), no. 10 (October 1, 2020): 70–76. http://dx.doi.org/10.33920/med-08-2010-08.
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For determining 22 volatile organic compounds in the atmospheric air, the operating modes of the gas chromatographic complexes «chromatography-mass spectrometer — two-stage thermodesorber» and «gas chromatograph with 2 FID — static headspace analysis sampler» are optimized. The modes provide the values of the separation coefficients of the chromatographic peaks in the range of 1.5 ÷ 21. It has been experimentally established that the highest desorption efficiency of volatile organic compounds is registered when the sample is concentrated into Tenax TA sorption tubes.
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Alamoudi, Abdullah, Syed Muhammad Saaduddin, Abu Bakar Munir, Firdaus Muhammad-Sukki, Siti Hawa Abu-Bakar, Siti Hajar Mohd Yasin, Ridoan Karim, et al. "Using Static Concentrator Technology to Achieve Global Energy Goal." Sustainability 11, no. 11 (May 30, 2019): 3056. http://dx.doi.org/10.3390/su11113056.
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Solar energy has demonstrated promising prospects in satisfying energy requirements, specifically through solar photovoltaic (PV) technology. Despite that, the cost of installation is deemed as the main hurdle to the widespread uptake of solar PV systems due to the use of expensive PV material in the module. At this point, we argue that a reduction in PV cost could be achieved through the usage of concentrator. A solar concentrator is a type of lens that is capable of increasing the collection of sun rays and focusing them onto a lesser PV area. The cost of the solar module could then be reduced on the assumption that the cost of introducing the solar concentrator in the solar module design is much lower than the cost of the removed PV material. Static concentrators, in particular, have great promise due to their ability to be integrated at any place of the building, usually on the building facade, windows and roof, due to their low geometrical concentration. This paper provides a historic context on the development of solar concentrators and showcases the latest technological development in static PV concentrators including non-imaging compound parabolic concentrator, V-trough, luminescent solar concentrator and quantum dot concentrator. We anticipated that the static low concentrating PV (LCPV) system could serve to enhance the penetration of PV technology in the long run to achieve the Sustainable Development Goal (SDG) 7—to open an avenue to affordable, reliable, sustainable, and modern energy for all by 2030.
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Martinez, V., B. Alorda, A. Moia, and R. Pujol. "Low-cost orientation system for a concentrating solar collector with static reflector and tracking receiver." Renewable Energy and Power Quality Journal 1, no. 04 (April 2006): 80–84. http://dx.doi.org/10.24084/repqj04.241.
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Xuan, Qingdong, Guiqiang Li, Yashun Lu, Xudong Zhao, Yuehong Su, Jie Ji, and Gang Pei. "A general optimization strategy for the annual performance enhancement of a solar concentrating system incorporated in the south-facing wall of a building." Indoor and Built Environment 29, no. 10 (September 29, 2019): 1386–98. http://dx.doi.org/10.1177/1420326x19878217.
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A solar concentrating system incorporated to the south-facing wall could be a promising solution to alleviate the energy demand pressure in buildings. However, concentrating systems incorporated in south-facing walls would require wide acceptance range of concentrators with the purpose of static installation. In order to tackle this problem, this article proposes a novel unitary asymmetric concentrator structure for incorporating the concentrating system in the south-facing wall. A general optimization strategy for the annual performance enhancement of the concentrator is reported. Four kinds of concentrators were designed based on the proposed structure. The annual performance enhancement by this optimization strategy was analysed and compared through the ray-tracing simulation and experimental validation for four typical types of solar concentrators, i.e. Mirror Concentrator, Lens-Mirror Concentrator, Dielectric Concentrator and Air-Gap-Lens-Mirror Concentrator. The optical performance of these concentrators was studied and compared. Their application was analysed and validated through the analysis. The findings have illustrated the optical efficiency of the concentrators for concentrating the photovoltaics or photovoltaic-thermal system incorporated to the south-facing wall either by attachment or embedded into a building structure like a window. These concentrators can be engineered as the main component as a part of the design for a building.
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Padilla de la Rosa, J., Priscilla Ruiz-Palomino, Enrique Arriola-Guevara, Jorge García-Fajardo, Georgina Sandoval, and Guadalupe Guatemala-Morales. "A Green Process for the Extraction and Purification of Hesperidin from Mexican Lime Peel (Citrus aurantifolia Swingle) that is Extendible to the Citrus Genus." Processes 6, no. 12 (December 15, 2018): 266. http://dx.doi.org/10.3390/pr6120266.
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The processing of Mexican limes generates great amounts of peel as a by-product. Lime peel is mainly rich in the flavonoid hesperidin, whose bioactivity is oriented mainly to cardiovascular diseases and cancer. The purpose of this work was to develop a green process for the extraction and purification of hesperidin from Mexican lime peel. The extraction of hesperidin was investigated on a laboratory scale by varying the solvent composition and the solid-to-solvent ratio, and then scaling this process (volume: 20 L). Next, a purification process using adsorption resins was assessed: first through static tests to determine the adsorption efficiency with two resins (FPX66, EXA118), and then on a packed column with 80 mL of resin at 25 °C. Lab-scale extraction showed that the best conditions were a solid-to-solvent ratio of 0.33 g/mL and 60% ethanol. After using these conditions at pilot scale and concentrating the solution, the hesperidin content of the extract was 0.303 mg/mL. Through static tests, higher adsorption efficiencies were achieved with the EXA-118 resin and diluted extract (4:6 ratio with 10% dimethylsulfoxide, (DMSO)). Finally, the purification process on a packed column from the diluted extract (hesperidin concentration of 0.109 mg/mL) had a mean recovery efficiency of almost 90%.
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MAZILU, NICOLAE, PAVLOS D. IOANNOU, FOTIOS K. DIAKONOS, XANTIS N. MAINTAS, and MARICEL AGOP. "A QUARK-INDEPENDENT DESCRIPTION OF CONFINEMENT." Modern Physics Letters A 28, no. 30 (September 12, 2013): 1350126. http://dx.doi.org/10.1142/s0217732313501265.
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Currently the quantitative description of confinement inside nuclear matter is exclusively limited to computer experiments, mainly on lattices, and concentrating upon calculating the static potential. There is no independent reference for comparison and support of the results, especially when it comes to the quark potential in the continuum limit. Yet, we are entitled to be optimistic, for the basic results of these calculations seem to be correct from an entirely different point of view, suggested by Manton's geometrization of Skyrme theory. The present work shows the reasons of this point of view, and offers a static potential that might serve as independent reference for comparison and endorsement of any lattice calculations, and in fact of any structural hypotheses of nuclear matter. A historical review of the pertinent key moments in the history of modeling of nuclear matter, as well as an outlook anticipating the necessary future work, close the argument.
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Zhang, Hai Yue, Sheng Ting Han, Ying Wei, and Man Liu. "Research on Resin Separation Technology of Resveratrol and Catechin from Peanut Skin." Advanced Materials Research 610-613 (December 2012): 3450–60. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.3450.
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Research had been carried out on the technology of separating resveratrol and catechin extracted from the peanuts skin. The macroprous adsorption resin AB-8 had been selected from 3 kinds of carriers by static adsorption and deadsorption test. The single factor tests and response surface experiments had been applied to optimize the enrichment and separation condition of resveratrol and catechin. The optimum adsorption conditions were as follows: feeding rate 2mL/min, pH 6.0 with the concentration of resveratrol and catechin to be 2µg/mL and 0.5mg/mL respectively. The optimum elution conditions were elution rate 1.5 mL/min and pH5.0. Resveratrol and catechin could be purified and separated by different conditions. Resveratrol was eluted by 20% ethanol while catechin by 60% ethanol. After concentrating and drying, the contents of resveratrol and catechin were 49.63% and 91.07%, respectively.
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Lo, Wei-Chen, Ching-Hsiang Fan, Yi-Ju Ho, Chia-Wei Lin, and Chih-Kuang Yeh. "Tornado-inspired acoustic vortex tweezer for trapping and manipulating microbubbles." Proceedings of the National Academy of Sciences 118, no. 4 (January 6, 2021): e2023188118. http://dx.doi.org/10.1073/pnas.2023188118.
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Spatially concentrating and manipulating biotherapeutic agents within the circulatory system is a longstanding challenge in medical applications due to the high velocity of blood flow, which greatly limits drug leakage and retention of the drug in the targeted region. To circumvent the disadvantages of current methods for systemic drug delivery, we propose tornado-inspired acoustic vortex tweezer (AVT) that generates net forces for noninvasive intravascular trapping of lipid-shelled gaseous microbubbles (MBs). MBs are used in a diverse range of medical applications, including as ultrasound contrast agents, for permeabilizing vessels, and as drug/gene carriers. We demonstrate that AVT can be used to successfully trap MBs and increase their local concentration in both static and flow conditions. Furthermore, MBs signals within mouse capillaries could be locally improved 1.7-fold and the location of trapped MBs could still be manipulated during the initiation of AVT. The proposed AVT technique is a compact, easy-to-use, and biocompatible method that enables systemic drug administration with extremely low doses.
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Reeves, W. B., D. A. Molony, and T. E. Andreoli. "Diluting power of thick limbs of Henle. III. Modulation of in vitro diluting power." American Journal of Physiology-Renal Physiology 255, no. 6 (December 1, 1988): F1145—F1154. http://dx.doi.org/10.1152/ajprenal.1988.255.6.f1145.
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This paper considers the quantitative interplay of various factors in modulating diluting power of in vitro medullary and cortical thick ascending limbs of Henle (MTAL and CTAL, respectively) segments from mouse and rabbit. Experimentally, the measured diluting power of the in vitro rabbit CTAL is greater than that of the rabbit MTAL, although the inherent rate of net Cl- absorption at high perfusion rates is considerably greater in the rabbit MTAL than in the rabbit CTAL. Similar results apply when comparing the rabbit CTAL to the mouse MTAL exposed to antidiuretic hormone (ADH). Our calculations show that, in the rabbit CTAL, the measured static head luminal salt concentration can be accounted for quantitatively by the measured rate of net salt absorption at a high perfusion rate together with the passive permeability coefficients for Na+ and Cl-. Moreover, with perfusion rates of 10% of single-nephron glomerular filtration rate, the transport properties of the CTAL predict that, at the end of the CTAL, the static head luminal Cl- concentration occurs if the initial perfusate contains either 50 or 150 mM Cl-. Thus one can argue that, in vivo the CTAL may be the cardinal determinant of the TAL contribution to diluting power and to external salt balance. The relatively blunted diluting power of in vitro MTAL segments can be accounted for quantitatively by assuming that luminal dilution, and the attendant osmotic gradient from lumen to cell, suppresses the inherent rate of transcellular Cl- transport. Our calculations also show that prostaglandin E2 and peritubular osmolality increases blunt tubular diluting power. Thus in vivo, the MTAL segment may be the cardinal determinant of TAL contribution to concentrating power and to intrarenal salt balance.
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Rocca, Jean-Louis. "Corruption and its Shadow: An Anthropological View of Corruption in China." China Quarterly 130 (June 1992): 402–16. http://dx.doi.org/10.1017/s0305741000040807.
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There has been little systematic research on corruption in China. Analyses so far often only reveal various cases of corruption and conclude by commenting on the retrograde aspect of the Chinese state. Work of this nature also tends to be too static – not considering the historical and cultural dimensions of politics – and too superficial – just concentrating on anecdotal aspects of corruption. As a result, one could quite simply conclude that what is required is a Weberian bureaucracy, which would be both rational and efficient, though without explaining how this should come about.However, in the light of works dealing with the shifting role of the state in societies which are undergoing change, the causes and nature of the phenomenon of “corruption” in China can be reassessed.
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Wang, Jiaming, Yiming Jiang, Yifan Ni, Angjian Wu, and Jin Li. "Investigation on static and dynamic corrosion behaviors of thermal energy transfer and storage system materials by molten salts in concentrating solar power plants." Materials and Corrosion 70, no. 1 (July 27, 2018): 102–9. http://dx.doi.org/10.1002/maco.201810362.
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Britton, Damon, Craig N. Mundy, Christina M. McGraw, Andrew T. Revill, and Catriona L. Hurd. "Responses of seaweeds that use CO2 as their sole inorganic carbon source to ocean acidification: differential effects of fluctuating pH but little benefit of CO2 enrichment." ICES Journal of Marine Science 76, no. 6 (April 25, 2019): 1860–70. http://dx.doi.org/10.1093/icesjms/fsz070.
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AbstractLaboratory studies that test the responses of coastal organisms to ocean acidification (OA) typically use constant pH regimes which do not reflect coastal systems, such as seaweed beds, where pH fluctuates on diel cycles. Seaweeds that use CO2 as their sole inorganic carbon source (non-carbon dioxide concentrating mechanism species) are predicted to benefit from OA as concentrations of dissolved CO2 increase, yet this prediction has rarely been tested, and no studies have tested the effect of pH fluctuations on non-CCM seaweeds. We conducted a laboratory experiment in which two ecologically dominant non-CCM red seaweeds (Callophyllis lambertii and Plocamium dilatatum) were exposed to four pH treatments: two static, pHT 8.0 and 7.7 and two fluctuating, pHT 8.0 ± 0.3 and 7.7 ± 0.3. Fluctuating pH reduced growth and net photosynthesis in C. lambertii, while P. dilatatum was unaffected. OA did not benefit P. dilatatum, while C. lambertii displayed elevated net photosynthetic rates. We provide evidence that carbon uptake strategy alone cannot be used as a predictor of seaweed responses to OA and highlight the importance of species-specific sensitivity to [H+]. We also emphasize the importance of including realistic pH fluctuations in experimental studies on coastal organisms.
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Shaymatov, Sanjar, Bobomurat Ahmedov, Zdeněk Stuchlík, and Ahmadjon Abdujabbarov. "Effect of an external magnetic field on particle acceleration by a rotating black hole surrounded with quintessential energy." International Journal of Modern Physics D 27, no. 08 (May 30, 2018): 1850088. http://dx.doi.org/10.1142/s0218271818500888.
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We investigate particle motion and collisions in the vicinity of rotating black holes immersed in combined cosmological quintessential scalar field and external magnetic field. The quintessential dark-energy field governing the spacetime structure is characterized by the quintessential state parameter [Formula: see text] characterizing its equation of state, and the quintessential field-intensity parameter [Formula: see text] determining the static radius where the black hole attraction is just balanced by the quintessential repulsion. The magnetic field is assumed to be test field that is uniform close to the static radius, where the spacetime is nearly flat, being characterized by strength [Formula: see text] there. Deformations of the test magnetic field in vicinity of the black hole, caused by the Ricci non-flat spacetime structure are determined. General expression of the center-of-mass energy of the colliding charged or uncharged particles near the black hole is given and discussed in several special cases. In the case of nonrotating black holes, we discuss collisions of two particles freely falling from vicinity of the static radius, or one such a particle colliding with charged particle revolving at the innermost stable circular orbit. In the case of rotating black holes, we discuss briefly particles falling in the equatorial plane and colliding in close vicinity of the black hole horizon, concentrating attention to the interplay of the effects of the quintessential field and the external magnetic field. We demonstrate that the ultra-high center-of-mass energy can be obtained for black holes placed in an external magnetic field for an infinitesimally small quintessential field-intensity parameter [Formula: see text]; the center-of-mass energy decreases if the quintessential field-intensity parameter [Formula: see text] increases.
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Fawcett, David, Tristan Pearce, Roland Notaina, James D. Ford, and Peter Collings. "Inuit adaptability to changing environmental conditions over an 11-year period in Ulukhaktok, Northwest Territories." Polar Record 54, no. 2 (March 2018): 119–32. http://dx.doi.org/10.1017/s003224741800027x.
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ABSTRACTCurrent understanding of climate change impacts, adaptation and vulnerability among Inuit in the Arctic is relatively static, rooted in the community and time that case studies were conducted. This paper captures the dynamism of Inuit–climate relationships by applying a longitudinal approach to assessing vulnerability to climate change among Inuit in Ulukhaktok, Northwest Territories, Canada. Data were collected in 2005 and 2016 following a consistent methodology and analytical framework. Findings from the studies are analysed comparatively together with longitudinal datasets. The data reveal that many of the climatic changes recorded in 2005 that adversely affected hunting activities have been observed to be persisting or progressing, such as decreasing sea ice thickness and extent, and stronger and more consistent summer winds. Inuit are responding by altering travel routes and equipment, taking greater pre-trip precautions, and concentrating their efforts on more efficient and accessible hunts. Increasing living and subsistence costs and time-constraints, changes in the generation and transmission of environmental knowledge and land skills, and the concentration of country food sharing networks were identified as key constraints to adaptation. The findings indicate that the connections between subsistence activities and the wage economy are central to understanding how Inuit experience and respond to climate change.
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Zehro, Khosro, and Shahram Jkhsi. "Evaluation of plastic hinges performance and the elastic stiffness factor of moment-resisting frame structures." International Journal of Advanced Engineering, Sciences and Applications 1, no. 3 (July 15, 2020): 10–17. http://dx.doi.org/10.47346/ijaesa.v1i3.30.
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Nowadays, to analyse and determine the maximum seismic lateral displacement for reinforced concrete (RC) structures, the most applicable procedure used by structural engineers is the nonlinear static (pushover) analysis. The nonlinear static procedure (NSP) is a common approach for analysing the seismic performance of construction structures. By directing this procedure, the weak points in each structural member can be examined, and it also determines whether the members are safe or need to rehabilitate. This process defines the level of performance and shear strength under seismic diffusion to construct each element of the structure. The displacement, the base shear, the plastic hinge model, and the effect of the different plan on seismic response of structures has been reported. When concentrating on the RC structures, it requires the ability to conduct lateral resistant force systems, which one of them is commonly known as moment-resisting frames (MRFs). In this paper, three models of RC structures considered for low-, medium-, and high-rise buildings were examined, and each model has been analysed for three different spans. These models have been analysed applying ETABS software by inputting and examining a wide range of structural parameters. A comprehensive study on the pushover curve, performance curve, among others have been performed. The aim of this study is to consider the effect of plastic hinges in various ranges of performance capacities to evaluate the elastic stiffness factor of structures
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Zeng, Yingying, Stefan E. Weishaar, and Oscar Couwenberg. "Absolute vs. Intensity-based Caps for Carbon Emissions Target Setting." European Journal of Risk Regulation 7, no. 4 (December 2016): 764–81. http://dx.doi.org/10.1017/s1867299x00010187.
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AbstractLinking the European Union Emissions Trading System (EU ETS) to the Chinese national ETS promises considerable economic and political benefits. However, different policy choices regarding cap setting between the systems are likely to impede a potential linking. A striking distinction is that the EU ETS relies upon an absolute cap, while the Chinese national ETS appears to apply an ‘intensity-based cap’ during the early stages. The current linking literature focuses on mapping legal barriers in general and has not yet focused on EU and China, let alone the intricacies of policy design. This article seeks to fill this gap by concentrating on (static and dynamic) efficiency and environmental effectiveness implications of linking and cap design. From the analysis of the cap we derive policy implications for a hypothetical ETS linking between the EU and China. In response, comprehensive and predictable regulation is needed to ensure the attainment of ETS targets and thus facilitate better regulation.
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Schmidt-Nowara, Christopher. "Still Continents (and an Island) with Two Histories?" Law and History Review 22, no. 2 (2004): 377–82. http://dx.doi.org/10.2307/4141651.
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Historians of Latin American slavery will find de la Fuente's article to be a particularly trenchant and learned essay on familiar historiographic controversies. The archival research awakens anticipation for the author's in-depth study of the earlier period of Cuban slavery, much neglected in favor of the heyday of the sugar complex of the late eighteenth and nineteenth centuries. Concentrating on the law and “slaves' claims-making” (341) allows for an important entry into the subject, complementing recent studies of slavery in Spanish America that have focused on how slaves used the institutions of Spanish colonialism to gain freedom or greater autonomy. However, reviving the Tannenbaum thesis, even in the limited form of the law, inspires less enthusiasm. De la Fuente's interpretation of Cuban slavery, through his rereading of Tannenbuam, does not produce misrepresentations in his treatment of historiography or sources; rather, I sense in this work the static conception of New World slavery created by Tannenbaum's dichotomous vision, both among and within particular colonial and national slave societies.
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Amit, Yali, and Donald Geman. "A Computational Model for Visual Selection." Neural Computation 11, no. 7 (October 1, 1999): 1691–715. http://dx.doi.org/10.1162/089976699300016197.
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We propose a computational model for detecting and localizing instances from an object class in static gray-level images. We divide detection into visual selection and final classification, concentrating on the former: drastically reducing the number of candidate regions that require further, usually more intensive, processing, but with a minimum of computation and missed detections. Bottom-up processing is based on local groupings of edge fragments constrained by loose geometrical relationships. They have no a priori semantic or geometric interpretation. The role of training is to select special groupings that are moderately likely at certain places on the object but rare in the background. We show that the statistics in both populations are stable. The candidate regions are those that contain global arrangements of several local groupings. Whereas our model was not conceived to explain brain functions, it does cohere with evidence about the functions of neurons in V1 and V2, such as responses to coarse or incomplete patterns (e.g., illusory contours) and to scale and translation invariance in IT. Finally, the algorithm is applied to face and symbol detection.
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Su, Y. X., B. Y. Duan, R. D. Nan, and B. Peng. "Development of a pilot of an Arecibo-type large spherical radio telescope for the square kilometre array." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 215, no. 11 (November 1, 2001): 1321–29. http://dx.doi.org/10.1243/0954406011524702.
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An optomechatronics design project for the pilot of an Arecibo-type large spherical radio telescope for the square kilometre array (SKA) is proposed, concentrating on the feed-supporting system with large-span cables. The feed-supporting system consists of two parallel manipulators: the parallel cable manipulator, which provides a large workspace for the trajectory tracking and realizes the coarse tracking control, and the fine-tuning Stewart platform, which connects the parallel cable manipulator to the cabin structure and implements the high-accuracy requirement of tracking. In order to improve the real-time controllability, an approximate kinematics model of the parallel cable manipulator is developed using straight links to approximate the cables based on static equilibrium at low tracking velocity. A control strategy for the feed-supporting system is proposed using the independent control method, and the corresponding tracking accuracy of the coarse control and fine tuning is presented. The simulation results have supported the rationale of this approximate model of the parallel cable manipulator and the feasibility of this mechatronics design project for the SKA.
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MIN¯ANO, J. C. "Static Concentration." International Journal of Solar Energy 6, no. 6 (January 1988): 367–86. http://dx.doi.org/10.1080/01425918808914240.
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Guo, Rumeng, Hongfeng Yang, Yifan Zhu, Yong Zheng, Jianqiao Xu, Lupeng Zhang, and Chao An. "Narrow Rupture of the 2020 Mw 7.4 La Crucecita, Mexico, Earthquake." Seismological Research Letters 92, no. 3 (January 13, 2021): 1891–99. http://dx.doi.org/10.1785/0220200328.
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Abstract On 23 June 2020, a large (Mw 7.4) interplate thrust earthquake struck near the town of La Crucecita in the state of Oaxaca in southern Mexico, following a 55-yr interseismic period. A seismic source model is well constrained by teleseismic waveforms, static Global Positioning System offsets, and tsunami data, suggesting that the earthquake occurred on the slab interface at a dip of ∼23°, with a narrow elliptical asperity concentrating around a shallow depth of ∼20 km. The rupture propagates bilaterally from the hypocenter, and the down-dip rupture is restricted to ∼25 km by slow slip events (SSEs). The down-dip shear stress is released by SSEs during the interseismic period, limiting the earthquake magnitude and possibly resulting in the characteristic earthquake. The 2020 La Crucecita event, thus, is a good reminder to assess the seismic and tsunami potential in this region. The stress changes caused by the coseismic slip of the 2017 Mw 8.2 Chiapas earthquake are too small to trigger the 2020 La Crucecita earthquake. However, combined with the postseismic afterslip effects that play a leading role, it greatly promotes the eventual occurrence of the La Crucecita event. The results demonstrate the importance of considering postseismic afterslip, when evaluating seismic hazard and its migratory pattern.
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Sathish G, Swarnakumari P, and Ramya R. "SEAS Exercise to Treat Scoliosis and Improve Functional Activities in Children with Spastic Cerebral Palsy." International Journal of Research in Pharmaceutical Sciences 11, no. 3 (July 8, 2020): 3362–66. http://dx.doi.org/10.26452/ijrps.v11i3.2471.
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SEAS exercise to improve functional activities among the children with spastic hemiplegic cerebral palsy children. Single group pre- post experimental research design. Cerebral paralysis is a static encephalopathy which affects the immature brain and leads to permanent motor disability. Due to a combination of spasticity, muscle weakness and incompletion of muscle control, the spinal deformity occurs in rising patients with CP; it can lead to poor balance in the trunk and significantly limits patient function. SEAS exercise capacity to enhance the self-corrected posture by concentrating during everyday activities. Eighty eight subjects of spastic hemiplegic cerebral palsied children, aged 6-12, male and female with scoliosis were selected under purposive sampling technique and received SEAS exercise training for a period of eight weeks. pre and post outcome measures were assessed using Modified Ashworth scale and Scoliometer to measure the functional activity in the children Pediatric balance scale, functional gait assessment and Gross motor function were used. Significant changes in spasticity and scoliosis were observed, and functional parameters were increased. The results of the post-test mean values for all SEAS variables demonstrated substantial improved balance, reduced scoliosis and gross motor functions in those receiving SEAS protocol (p<0.05). The SEAS exercise proves there was a decrease in scoliosis and their by improvement in functional abilities among children with spastic hemiplegic cerebral palsy after eight weeks of intervention.
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Ekinci, Esra, and Adil Baykasoğlu. "Complexity and performance measurement for retail supply chains." Industrial Management & Data Systems 119, no. 4 (May 13, 2019): 719–42. http://dx.doi.org/10.1108/imds-08-2018-0342.
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Purpose The purpose of this paper is to present how complexity on retail supply chains should be recognized and its relationship with the performance. Different supply chain structures and planning horizons have been analyzed to support practitioners taking action on the short, mid and long terms. Confronted complexity in the supply chain has been categorized as system, perceived and value adding. This would also help practitioners to understand the sources of the complexity and if the complexity is useful for the system or not. Design/methodology/approach Three different retail supply chain scenarios – each concentrating on different planning horizons – have been simulated on system dynamics software STELLA. Using the new classification scheme for complexity and suggested performance metrics, a multi-perspective analysis has been performed on the STELLA output. Findings The results and the methodology can be easily applicable in practice to support decision-making process and to answer “what-if” type scenario analysis on systems design and configuration. Using the selected complexity metrics, complexity of the system considering time factor – static and dynamic – and different information levels – system, perceived and value adding – has been evaluated. Used complexity metrics indicate the problematic areas in the systems to be distinguished. Originality/value This paper uses system dynamics modeling in retail supply chains to derive insight about dynamic behavior and to represent the complex interactions and a new classification scheme for system complexity.
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De Pascalis, F., D. Pala, D. Pisu, J. Morinay, A. Benvenuti, C. Spano, A. Ruiu, L. Serra, D. Rubolini, and JG Cecere. "Searching on the edge: dynamic oceanographic features increase foraging opportunities in a small pelagic seabird." Marine Ecology Progress Series 668 (June 24, 2021): 121–32. http://dx.doi.org/10.3354/meps13726.
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Ocean mesoscale and submesoscale features, such as eddies and filaments, play a key role in the foraging ecology of marine predators, by concentrating nutrients and acting as aggregative structures for pelagic organisms. Highly pelagic seabirds may exploit these features to find profitable food patches in a dynamic and complex 3-dimensional spatial environment. Using miniaturized GPS loggers, we investigated whether foraging habitat selection of the Mediterranean storm petrel Hydrobates pelagicus melitensis, one of the smallest (ca. 28 g) seabirds worldwide, was affected by different static and dynamic oceanographic features during the breeding period. Individuals performed long foraging trips (up to 1113 km) in a relatively short time (1 to 2 d), covering large home ranges (up to 34370 km2), particularly during incubation. Different oceanographic features affected the at-sea distribution of storm petrels at different spatio-temporal scales. During incubation, individuals selected areas characterized by shallow waters and strong currents, conditions that may enhance vertical water mixing and increase food availability. During chick-rearing, they foraged closer to the colony, selecting shallow and productive areas, where increasing Lagrangian coherent structures and eddy kinetic energy enhanced foraging probability. These features could play an important role in storm petrels’ foraging habitat selection, especially during chick-rearing, given their need to find predictable food patches in a short timespan. Overall, our results suggest that marine circulation processes are key drivers of the at-sea distribution of this small pelagic surface predator.
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Hickling, Tom, and Grant Ingram. "Reynolds-averaged Navier–Stokes modelling in transonic S-ducts with passive flow control." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 234, no. 1 (May 17, 2019): 31–45. http://dx.doi.org/10.1177/0957650919845765.
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S-duct diffusers are used in aircraft with embedded engines to route ambient air to the fan face. Sizing and stealth considerations drive a need for high curvature ducts, but the curvature causes complex secondary flows that lead to total pressure distortion and swirl velocities at the engine face. These must be controlled for stable engine operation. In this paper, tubercles, a novel bio-inspired passive flow control method, are analysed numerically in a duct with transonic flow. The results are compared to experimental data obtained as part of a campaign at the Royal Military College, Canada to investigate the effects of S-duct geometry and novel passive flow control devices on the performance of transonic S-ducts. The performance of Reynolds-averaged Navier–Stokes turbulence models in the S-ducts is assessed – Menter's shear stress transport model predicts excessive losses due to the overactivity of its stress limiter. The realisable k–ɛ model gives a significant improvement in the prediction of static pressure distributions, but losses and distortion characteristics are predicted poorly due to the model's inability to resolve the effects of unsteadiness in separated regions. Large tubercle geometries are found to trigger earlier separation in the centre of the duct by concentrating low momentum fluid in valleys, but they also act as boundary layer fences away from the duct centre. Smaller geometries are found to generate vortices that re-energise the boundary layer, delaying flow separation. Methods are recommended for future computational analyses of S-ducts and new designs of tubercles.
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Bellanger, Anne-Pauline, Alexander M. Tatara, Fazal Shirazi, Teclegiorgis Gebremariam, Nathaniel D. Albert, Russell E. Lewis, Ashraf S. Ibrahim, and Dimitrios P. Kontoyiannis. "Statin Concentrations Below the Minimum Inhibitory Concentration Attenuate the Virulence ofRhizopus oryzae." Journal of Infectious Diseases 214, no. 1 (March 16, 2016): 114–21. http://dx.doi.org/10.1093/infdis/jiw090.
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Mei, Mah Pui, Yu Pei Xiao, Anthony Maraveyas, Camille Ettelaie, and Mary E. W. Collier. "Enhanced binding of tissue factor-microparticles to collagen-IV and fibronectin leads to increased tissue factor activity in vitro." Thrombosis and Haemostasis 109, no. 01 (2013): 61–71. http://dx.doi.org/10.1160/th12-05-0279.
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SummaryThe role of tissue factor (TF)-containing microparticles in clot propagation has been established, but the ability of circulating microparticles to initiate coagulation has been disputed. However, TF-bearing microparticles, particularly endothelial-microparticles generated during disease, may interact with extracellular matrices which in turn can localise circulating TF to sites of injury. In order to examine this hypothesis in vitro, microparticles were isolated from human coronary artery endothelial cells transfected to overexpress TF, tumour-necrosis factor (TNF)α-treated cells or non-transfected cells lacking TF. The ability of microparticles to bind collagen-IV, fibronectin and fibrin was examined under static conditions and arterial shear rates (650 s-1), and also in the presence of inhibitory antibodies against β1-, β3-, α3-and αv-integrins or an anti-TF antibody. TF-microparticles showed increases of up to 43% and 24% in adherence to collagen-IV and fibronectin, respectively, compared to control microparticles under shear flow. Furthermore, TF-containing microparticles, but not the transfected parent cells had increased levels of β1-integrin compared to TF-deficient microparticles. Pre-incubation of microparticles with a β1-integrin-blocking antibody counteracted the additional adhesion of TFmicroparticles compared to control microparticles. Finally, adherence of TF microparticles to collagen-IV or fibronectin resulted in increased TF activity by concentrating TF onto the surface. In conclusion, the presence of TF within microparticles enhances the interactions of endothelial cell-derived microparticles with extracellular matrices in an integrin-dependent manner. Accumulation and localisation of these microparticles in turn results in the enhancement of TF activity. This may be an innate mechanism by which TF-bearing microparticles induce coagulation upon vascular injury.
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Kobayashi, Tsutomu, Katsumi Tashiro, Ken Yamamoto, Shunichi Nitta, Shigeo Ohmura, and Yasuhiro Suzuki. "Effects of surfactant proteins SP-B and SP-C on dynamic and static mechanics of immature lungs." Journal of Applied Physiology 83, no. 6 (December 1, 1997): 1849–56. http://dx.doi.org/10.1152/jappl.1997.83.6.1849.
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Kobayashi, Tsutomu, Katsumi Tashiro, Ken Yamamoto, Shunichi Nitta, Shigeo Ohmura, and Yasuhiro Suzuki. Effects of surfactant proteins SP-B and SP-C on dynamic and static mechanics of immature lungs. J. Appl. Physiol. 83(6): 1849–1856, 1997.—To investigate the effects of surfactant proteins B (SP-B) and C (SP-C) on lung mechanics, we compared tidal and static lung volumes of immature rabbits anesthetized with pentobarbital sodium and given reconstituted test surfactants (RTS). With a series of RTS having various SP-B concentrations (0–0.7%) but a fixed SP-C concentration (1.4%), both the tidal volume with 25-cmH2O insufflation pressure and the static volume deflated to 5-cmH2O airway pressure increased, significantly correlating with the SP-B concentration: the former increased from 6.5 to 26.0 ml/kg (mean), and the latter increased from 6.4 to 31.8 ml/kg. With another series of RTS having a fixed SP-B concentration (0.7%) but various SP-C concentrations (0–1.4%), the tidal volume increased from 5.1 to 24.8 ml/kg, significantly correlating with the SP-C concentration, whereas the static volume increased from 3.4 to 32.0 ml/kg, the ceiling value, in the presence of a minimal concentration of SP-C (0.18%). In conclusion, certain doses of SP-B and SP-C were indispensable for optimizing dynamic lung mechanics; the static mechanics, however, required significantly less SP-C.
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Korkut, T. B., E. Armakan, O. Ozaydin, K. Ozdemir, and A. Goren. "Design and comparative strength analysis of wheel rims of a lightweight electric vehicle using Al6063 T6 and Al5083 aluminium alloys." Journal of Achievements in Materials and Manufacturing Engineering 2, no. 99 (April 1, 2020): 57–63. http://dx.doi.org/10.5604/01.3001.0014.1776.
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Purpose: Use of aluminium alloys in critical parts of a vehicle is common since they can combine the two important properties of a material those are being strength and lightweight. The aim in this research is to guide to design process of a wheel with taking example of an electric race vehicle implementation. Design/methodology/approach: In this study, the fatigue strengths of wheels produced for a two-person racing electric vehicle (Demobil09) are evaluated by calculating maximum distortion energy criterion (Von Mises) with Finite Element Analysis. Findings: Aluminium alloy wheels are crucial safety related components and are subjected to static and dynamic loads directly. Using FEA results, the weight and equivalent stress of the wheel are both reduced. So, the energy consumption is also decreased. Modal frequencies of the wheel models are determined. Research limitations/implications: In this paper, the materials analysed are AL6063 T6 and Al5083 aluminium alloys. Different materials can be analysed in future works. Practical implications: This paper is focusing on how to reduce the energy consumption of a two-person electric vehicle concentrating on reducing the weight of vehicle wheels. The vehicle is more technological than mass production cars since it is an electric race car which uses a hub motor, the body and chassis are produced using carbon polymer composites and all electronic units are designed and produced. Although its specialities it has homologated safety equipment like seats and safety belts. Originality/value: All boundary conditions must be analysed in details and a strength analysis must be conducted during design of the wheels for different load cases to ensure the strength of a wheel while keeping the weight as low as possible. In this complex process, this paper can give some clues to designers for strengths and weights of the designs since three different wheel forms are evaluated for reducing energy consumption of the vehicle.
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Charlton-Menys, Valentine, D. John Betteridge, Helen Colhoun, John Fuller, Michael France, Graham A. Hitman, Shona J. Livingstone, et al. "Targets of Statin Therapy: LDL Cholesterol, Non-HDL Cholesterol, and Apolipoprotein B in Type 2 Diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS)." Clinical Chemistry 55, no. 3 (March 1, 2009): 473–80. http://dx.doi.org/10.1373/clinchem.2008.111401.
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Abstract Background: LDL can vary considerably in its cholesterol content; thus, lowering LDL cholesterol (LDLC) as a goal of statin treatment implies the existence of considerable variation in the extent to which statin treatment removes circulating LDL particles. This consideration is particularly applicable in diabetes mellitus, in which LDL is frequently depleted of cholesterol. Methods: Type 2 diabetes patients randomly allocated to 10 mg/day atorvastatin (n = 1154) or to placebo (n = 1196) for 1 year were studied to compare spontaneous and statin-induced apolipoprotein B (apo B) concentrations (a measure of LDL particle concentration) at LDLC and non-HDL cholesterol (non-HDLC) concentrations proposed as statin targets in type 2 diabetes. Results: Patients treated with atorvastatin produced lower serum apo B concentrations at any given LDLC concentration than patients on placebo. An LDLC concentration of 1.8 mmol/L (70 mg/dL) during atorvastatin treatment was equivalent to a non-HDLC concentration of 2.59 mmol/L (100 mg/dL) or an apo B concentration of 0.8 g/L. At the more conservative LDLC targets of 2.59 mmol/L (100 mg/dL) and 3.37 mmol/L (130 mg/dL) for non-HDLC, however, the apo B concentration exceeded the 0.9-g/L value anticipated in the recent Consensus Statement from the American Diabetes Association and the American College of Cardiology. Conclusions: The apo B concentration provides a more consistent goal for statin treatment than the LDLC or non-HDLC concentration.
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Cardilin, Tim, Joachim Almquist, Mats Jirstrand, Alexandre Sostelly, Christiane Amendt, Samer El Bawab, and Johan Gabrielsson. "Tumor Static Concentration Curves in Combination Therapy." AAPS Journal 19, no. 2 (September 28, 2016): 456–67. http://dx.doi.org/10.1208/s12248-016-9991-1.
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AL-OMARI, S. "MODELING THE CONCENTRATIONS AND EFFICIENCIES FOR THE INTERACTING SPECIES OF PYROPHEOPHORBIDE METHYL ESTER-COPPER ASSOCIATION." Biophysical Reviews and Letters 08, no. 01n02 (June 2013): 73–87. http://dx.doi.org/10.1142/s1793048013500045.
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The interaction between pyropheophorbide methyl ester (PPME) and Cu 2+ was investigated using UV-vis and fluorescence spectrscopy. Study of the binding interaction between PPME and Cu 2+ could contribute to understanding of its pharmacokinetics and pharmacodynamics. Parameters of the static and dynamic fluorescence quenching of PPME- Cu 2+ association were calculated at different temperatures. For binding site of 1:1 at 299 K, the static binding constant (kS), the static isosbestic concentration ([Formula: see text]), the dynamic binding constant (kD), and the dynamic isosbestic concentration ([Formula: see text]) are, respectively, 61 M-1, 0.0164 M, 75 M-1, and 0.0133 M. The concentrations and efficiencies of the intermediates species were modeled. Satisfactory correspondence between the experimental and calculated results was found.
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Frank, G. P., U. Dusek, and M. O. Andreae. "Technical Note: Characterization of a static thermal-gradient CCN counter." Atmospheric Chemistry and Physics 7, no. 12 (June 15, 2007): 3071–80. http://dx.doi.org/10.5194/acp-7-3071-2007.
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Abstract. The static (parallel-plate thermal-gradient) diffusion chamber (SDC) was one of the first instruments designed to measure cloud condensation nuclei (CCN) concentrations as a function of supersaturation. It has probably also been the most widely used type of CCN counter. This paper describes the detailed experimental characterization of a SDC CCN counter, including calibration with respect to supersaturation and particle number concentration. In addition, we investigated the proposed effect of lowered supersaturation because of water vapor depletion with increasing particle concentration. The results obtained give a better understanding why and in which way it is necessary to calibrate the SDC CCN counter. The calibration method is described in detail and can, in parts, be used for calibrations also for other types of CCN counters. We conclude the following: 1) it is important to experimentally calibrate SDC CCN counters with respect to supersaturation, and not only base the supersaturation on the theoretical description of the instrument; 2) the number concentration calibration needs to be performed as a function of supersaturation, also for SDC CCN counter using the photographic technique; and 3) we observed no evidence that water vapor depletion lowered the supersaturation.
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Frank, G. P., U. Dusek, and M. O. Andreae. "Technical note: Characterization of a static thermal-gradient CCN counter." Atmospheric Chemistry and Physics Discussions 6, no. 2 (March 29, 2006): 2151–74. http://dx.doi.org/10.5194/acpd-6-2151-2006.
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Abstract. The static (parallel-plate thermal-gradient) diffusion chamber (SDC) was one of the first instruments designed to measure cloud condensation nuclei (CCN) concentrations as a function of supersaturation. It has probably also been the most widely used type of CCN counter. This paper describes the detailed experimental characterization of a SDC CCN counter, including calibration with respect to supersaturation and particle number concentration. In addition, we investigated the proposed effect of lowered supersaturation because of water vapor depletion with increasing particle concentration. The results obtained gives a larger understanding why and in which way it is necessary to calibrate the SDC CCN counter. The calibration method is described in detail as well. The method can, in parts, be used for calibrations also for other types of CCN counters. We conclude the following: 1) it is important to experimentally calibrate SDC CCN counters with respect to supersaturation, and not only base the supersaturation on the theoretical description of the instrument; 2) the number concentration calibration needs to be performed as a function of supersaturation, also for SDC CCN counter using the photographic technique; and 3) we observed no evidence that water vapor depletion lowered the supersaturation.
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Rybicki, K. J., T. G. Waldrop, and M. P. Kaufman. "Increasing gracilis muscle interstitial potassium concentrations stimulate group III and IV afferents." Journal of Applied Physiology 58, no. 3 (March 1, 1985): 936–41. http://dx.doi.org/10.1152/jappl.1985.58.3.936.
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Static muscular contraction reflexly increases arterial blood pressure and heart rate. One possible mechanism evoking this reflex is that potassium accumulates in the interstitial space of a working muscle to stimulate group III and IV afferents whose activation in turn evokes a pressor response. The responses of group III and IV muscle afferents to increases in interstitial potassium concentrations within the range evoked by static contraction are unknown. Thus we injected potassium chloride into the gracilis artery of anesthetized dogs while we measured both gracilis muscle interstitial potassium concentrations with potassium-selective electrodes and the impulse activity of afferents in the gracilis nerve. We found that increasing interstitial potassium concentrations to levels similar to those seen during static contraction stimulated 14 of 16 group III and 29 of 31 group IV afferents. The responses of the afferents to potassium were concentration dependent. The typical response to potassium consisted of a burst of impulses, an effect that returned to control firing rates within 26 s, even though interstitial potassium concentrations remained elevated for several minutes. Although our results suggest that potassium may play a role in initiating the reflex cardiovascular responses to static muscular contraction, the accumulation of this ion does not appear to be solely responsible for maintaining the pressor response for the duration of the contraction.
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Teng, Tun-Ping, Yan-Bo Fang, Yu-Chun Hsu, and Li Lin. "Evaluating Stability of Aqueous Multiwalled Carbon Nanotube Nanofluids by Using Different Stabilizers." Journal of Nanomaterials 2014 (2014): 1–15. http://dx.doi.org/10.1155/2014/693459.
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The 0.5 wt.% multiwalled carbon nanotubes/water nanofluids (MWNFs) were produced by using a two-step synthetic method with different types and concentrations of stabilizers. The static position method, centrifugal sedimentation method, zeta potential measurements, and rheological experiments were used to assess the stability of the MWNFs and to determine the optimal type and fixed MWCNTs-stabilizer concentration of stabilizer. Finally, MWNFs with different concentrations of MWCNTs were produced using the optimal type and fixed concentration ratio of stabilizer, and their stability, thermal conductivity, and pH were measured to assess the feasibility of using them in heat transfer applications. MWNFs containing SDS and SDBS with MWCNTs-stabilizer concentration ratio were 5 : 2 and 5 : 4, respectively, showed excellent stability when they were evaluated by static position, centrifugal sedimentation, zeta potential, and rheological experiments at the same time. The thermal conductivity of the MWNFs indicated that the most suitable dispersing MWNF contained SDBS. MWNFs with MWCNTs concentrations of 0.25, 0.5, and 1.0 wt.% were fabricated using an aqueous SDBS solution. In addition, the thermal conductivity of the MWNFs was found to have increased, and the thermal conductivity values were greater than that of water at 25°C by 3.20%, 8.46%, and 12.49%.
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Paun, Irina Alexandra, Bogdan Stefanita Calin, Cosmin Catalin Mustaciosu, Mona Mihailescu, Antoniu Moldovan, Ovidiu Crisan, Aurel Leca, and Catalin Romeo Luculescu. "3D Superparamagnetic Scaffolds for Bone Mineralization under Static Magnetic Field Stimulation." Materials 12, no. 17 (September 3, 2019): 2834. http://dx.doi.org/10.3390/ma12172834.
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We reported on three-dimensional (3D) superparamagnetic scaffolds that enhanced the mineralization of magnetic nanoparticle-free osteoblast cells. The scaffolds were fabricated with submicronic resolution by laser direct writing via two photons polymerization of Ormocore/magnetic nanoparticles (MNPs) composites and possessed complex and reproducible architectures. MNPs with a diameter of 4.9 ± 1.5 nm and saturation magnetization of 30 emu/g were added to Ormocore, in concentrations of 0, 2 and 4 mg/mL. The homogenous distribution and the concentration of the MNPs from the unpolymerized Ormocore/MNPs composite were preserved after the photopolymerization process. The MNPs in the scaffolds retained their superparamagnetic behavior. The specific magnetizations of the scaffolds with 2 and 4 mg/mL MNPs concentrations were of 14 emu/g and 17 emu/g, respectively. The MNPs reduced the shrinkage of the structures from 80.2 ± 5.3% for scaffolds without MNPs to 20.7 ± 4.7% for scaffolds with 4 mg/mL MNPs. Osteoblast cells seeded on scaffolds exposed to static magnetic field of 1.3 T deformed the regular architecture of the scaffolds and evoked faster mineralization in comparison to unstimulated samples. Scaffolds deformation and extracellular matrix mineralization under static magnetic field (SMF) exposure increased with increasing MNPs concentration. The results are discussed in the frame of gradient magnetic fields of ~3 × 10−4 T/m generated by MNPs over the cells bodies.
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Nielsen, Elisabet I., Otto Cars, and Lena E. Friberg. "PredictingIn VitroAntibacterial Efficacy across Experimental Designs with a Semimechanistic Pharmacokinetic-Pharmacodynamic Model." Antimicrobial Agents and Chemotherapy 55, no. 4 (January 31, 2011): 1571–79. http://dx.doi.org/10.1128/aac.01286-10.
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ABSTRACTWe have previously described a general semimechanistic pharmacokinetic-pharmacodynamic (PKPD) model that successfully characterized the time course of antibacterial effects seen in bacterial cultures when exposed to static concentrations of five antibacterial agents of different classes. In this PKPD model, the total bacterial population was divided into two subpopulations, one growing drug-susceptible population and one resting drug-insensitive population. The drug effect was included as an increase in the killing rate of the drug-susceptible bacteria with a maximum-effect (Emax) model. The aim of the present study was to evaluate the ability of this PKPD model to describe and predict data fromin vitroexperiments with dynamic concentration-time profiles. Dynamic time-kill curve experiments were performed by using anin vitrokinetic system, where cultures ofStreptococcus pyogeneswere exposed to benzylpenicillin, cefuroxime, erythromycin, moxifloxacin, or vancomycin using different starting concentrations (2 and 16 times the MIC) and elimination conditions (human half-life, reduced half-life, and constant concentrations). The PKPD model was applied, and the observations for the static as well as dynamic experiments were compared to model predictions based on parameter estimation using (i) static data, (ii) dynamic data, and (iii) combined static and dynamic data. Differences in experimental settings between static and dynamic experiments did not affect the growth kinetics of the bacteria significantly. With parameter reestimation, the structure of our previously proposed PKPD model could well characterize the bacterial growth and killing kinetics when exposed to dynamic concentrations with different elimination rates of all five investigated antibiotics. Furthermore, the model with parameter estimates based on data from only the static time-kill curve experiments could predict the majority of the time-kill curves from the dynamic experiments reasonably well. Adding data from dynamic experiments in the estimation improved the model fit for cefuroxime and vancomycin, indicating some differences in sensitivity to experimental conditions among the antibiotics studied.
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CAMPBELL, CHARLES S. "Granular shear flows at the elastic limit." Journal of Fluid Mechanics 465 (August 25, 2002): 261–91. http://dx.doi.org/10.1017/s002211200200109x.
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This paper describes computer simulation studies of granular materials under dense conditions where particles are in persistent contact with their neighbours and the elasticity of the material becomes an important rheological parameter. There are two regimes at this limit, one for which the stresses scale with both elastic and inertial properties (called the elastic–inertial regime), and a non-inertial quasi-static regime in which the stresses scale purely elastically (elastic–quasi-static). In these elastic regimes, the forces are generated by internal force chains. Reducing the concentration slightly causes a transition from an elastic to a purely inertial behaviour. This transition occurs so abruptly that a 2% concentration reduction can be accompanied by nearly three orders of magnitude of stress reduction. This indicates that granular flows near this limit are prone to instabilities such as those commonly observed in shear cells. Unexpectedly, there is no path between inertial (rapid) flow and quasi-static flow by varying the shear rate at a fixed concentration; only by reducing the concentration can one cause a transition from quasi-static to inertial flow. The solid concentrations at which this transition occurs as well as the magnitude of the stresses in the elastic regimes are strong functions of the particle surface friction, because the surface friction strongly affects the strength of the force chains. A parametric analysis of the elastic regime generated flowmaps showing the various regimes that might be realized in practice. Many common materials such as sand require such large shear rates to reach the elastic–inertial regime that it is unattainable for all practical purposes; such materials will demonstrate either an elastic–quasi-static behaviour or a pure inertial behaviour depending on the concentration – with many orders of magnitude of stress change between them. Finally, the effects of nonlinear contacts are investigated and an appropriate scaling is proposed that accounts for the nonlinear behaviour in the elastic–quasi-static regime.
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Pan, Junfeng, Shaohong Liu, Shuwen Wang, and Yongxue Xia. "A New Theoretical View of Rockburst and Its Engineering Application." Advances in Civil Engineering 2018 (August 16, 2018): 1–12. http://dx.doi.org/10.1155/2018/4683457.
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Traditionally, rockburst is considered as a dynamic phenomenon of sudden destruction of coal/rock mass. In this study, rockburst is treated as an event process rather than a phenomenon. This paper introduces typical rockburst process, its classification, mechanism of internal and external causes, and energy criterion. Analysis indicates that rockburst is a dynamic process that includes three sequential phases: burst start-up, burst energy transfer, and rockburst pressure behavior. Excessive static stress concentration in the strata nearby the target zone appears to be the internal cause of rockburst start-up, while the external cause is the disturbance of the static stress concentration and additional load transfer by the concentrated dynamic load occurred at further distance. Potential burst start-up area is the highest stress concentration zone within the region where stress is in the critical equilibrium state. With the identified internal and external factors that contribute to rockburst start-up, it is concluded that the rockburst preventive measures should focus on the monitoring and controlling of originating source of static and dynamic stress concentrations. Field practice proves that the reunderstanding of rockburst and the derived preventive measures are feasible and successful.
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Abler, William L. "The Serrated Teeth of Tyrannosaurid Dinosaurs, and Biting Structures in Other Animals." Paleobiology 18, no. 2 (March 1992): 161–83. http://dx.doi.org/10.1017/s0094837300013956.
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The function of serrated teeth is analyzed by experimental comparison with the action of artificially made steel blades. Serrated blades cut compliant materials with a grip-and-rip mechanism, whereas smooth, sharp blades cut by concentrating a large downward force on a tiny area.Tyrannosaurid teeth from the Cretaceous Judith River Formation bear rows of serrations that have thick, rounded enamel caps, gripping slots between neighboring serrations, thick enamel bodies inside the teeth underneath the gripping slots, and a root beneath each serration. In contrast, the carnivorous dinosaur Troodon has teeth with exposed pointed serrations, thin enamel, and possibly serration roots.Serrations on the teeth of Troodon and the fossil shark Carcharodon, cut compliant materials in the same way as a serrated hacksaw blade. In contrast, the cutting action of tyrannosaurid teeth most closely resembles that of a dull smooth blade. The spaces between the serrations act as minute frictional vises that grip and hold meat fibers; chambers between neighboring serrations receive and retain small fragments of meat, and inevitably would have acted as havens where bacteria could be stored. These spaces may therefore have led to infections in wounds, analogous to those inflicted by the living Komodo dragon or ora. By analogy, the hunting and feeding behavior of tyrannosaurs may have resembled that of the ora.Serrations and slots are widely distributed among cutting devices in the natural world, and many of these deserve further study. For example, the carnassial teeth of mammalian carnivores cut by a combination of static force at the cutting edge, a crushing or scissoring action at the advancing junction between upper and lower teeth, and by lateral gripping and compression in a slot, like that seen on a much smaller scale in tyrannosaurid serrations. Mammalian teeth operate well only when deployed with sophisticated control over jaw movement, however, and the fine neural control necessary to operate them may have formed the basis for the later development of intelligence in mammals.Previously, being interested in mammals was largely a matter of being interested in teeth, whereas being interested in reptiles was largely a matter of being interested in everything but teeth. I suggest that the teeth of at least some reptiles are as rich in information as the teeth of any mammals.
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Pazos, Patricia, Salvador Fortaner, and Pilar Prieto. "Long-term In Vitro Toxicity Models: Comparisons Between a Flow-cell Bioreactor, a Static-cell Bioreactor and Static Cell Cultures." Alternatives to Laboratory Animals 30, no. 5 (September 2002): 515–23. http://dx.doi.org/10.1177/026119290203000505.
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In vitro long-term toxicity testing is becoming an important issue in the field of toxicology, and there is a need to develop new model systems that mimic human chronic exposure and its effects. The aim of this work was to test two long-term in vitro toxicity systems which are available, a flow-cell bioreactor (Tecnomouse) and a static cell bioreactor system (CELLine CL 6-well), and to compare them with the use of conventional cell culture flasks. A human cell line, Int 407, was exposed to cadmium chloride (CdCl2; 10–7–10–8M) for 4 weeks. Cell numbers and cell viabilities were determined by the trypan blue (TB) exclusion assay and from exclusion of propidium iodide (PI) as determined by flow cytometry; and cell viability and metabolic activity were determined by the MTT assay. In addition, total protein determination and cadmium uptake measurements were performed. The results obtained with TB and PI exclusion did not show clear differences in cell viability with increasing CdCl2 concentration. However, in the static cell-culture systems, an increase in MTT reduction was found at low concentrations of CdCl2. Expression of heat-shock protein (Hsp27 and Hsp70) increased differently, depending on the CdCl2 concentration applied and the system used. In summary, of the two bioreactors, the CELLine CL 6-well bioreactor was shown to be the more efficient system for performing long-term cytotoxicity studies. It is easy to handle, it permits the assessment of several endpoints, and sufficient replicates can be made available.
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Lee, Dong-Yub, Su A. Jung, and Hyun Jung Kim. "Changes in Distance Static Stereopsis with Breath Alcohol Concentration." Journal of Korean Ophthalmic Optics Society 22, no. 1 (March 30, 2017): 65–70. http://dx.doi.org/10.14479/jkoos.2017.22.1.65.
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Wan, C. C., A. B. Harris, and Deepak Kumar. "Heisenberg antiferromagnet with a low concentration of static defects." Physical Review B 48, no. 2 (July 1, 1993): 1036–61. http://dx.doi.org/10.1103/physrevb.48.1036.
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Cardilin, Tim, Joachim Almquist, Mats Jirstand, Alexandre Soselly, Christiane Amendt, Samer El Bawab, and Johan Gabrielsson. "Erratum to: Tumor Static Concentration Curves in Combination Therapy." AAPS Journal 19, no. 2 (January 5, 2017): 596. http://dx.doi.org/10.1208/s12248-016-0035-7.
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Shimada, Takayuki, Masao Doi, and Koji Okano. "Concentration fluctuation of stiff polymers. I. Static structure factor." Journal of Chemical Physics 88, no. 4 (February 15, 1988): 2815–21. http://dx.doi.org/10.1063/1.454016.
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