Artículos de revistas: "Inverted configuration"

1

Rashmi, M. R. y B. Anu. "Cascading of Diode Clamped Multilevel Inverter Boosters for High Voltage Applications". Applied Mechanics and Materials 313-314 (marzo de 2013): 876–81. http://dx.doi.org/10.4028/www.scientific.net/amm.313-314.876.

Texto completo

Resumen

Nonconventional energy sources are playing important role in meeting current power/energy demands. However these sources cannot provide High voltage/power. For power conditioning and voltage amplification solid state power converters are very much essential. One such approach to obtain high voltage was to use cascaded multilevel inverter but cascaded multilevel inverters require separate DC sources and they cannot be used for regenerative applications. To overcome these limitations, a novel configuration is using diode clamped multilevel inverter is proposed here. . The conditioned DC voltage from photovoltaic cells or fuel cells or batteries is boosted and inverted by means of multistage Multilevel Inverters (MLI). Three different configurations are presented in this paper. From the simulation results of all three configurations, the topology which is found to be better is implemented in the real time. A proto type is developed to boost 40 V input DC to 100 V AC and the experimental results for the same are presented.

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Köber, Helmuth y Marina Stoian. "Comments about the Seismic Behavior of “Inverted Y”- Braced Frames". Key Engineering Materials 763 (febrero de 2018): 106–15. http://dx.doi.org/10.4028/www.scientific.net/kem.763.106.

Texto completo

Resumen

Four configurations were analyzed for a ten storey “inverted Y-braced” frame with rigid and/or pined beam/column and diagonal/column connections. All considered frame configurations were sized for the forces produced by the same code seismic design force evaluated according to the in charge Romanian seismic design code. In case of two of the considered configurations, additional potentially plastic zones with reduced member cross-sections were provided along the girders and diagonals of the frame (in order to size clearly by design a global plastic failure mechanism for the “inverted Y-braced” frame). The behavior of each frame configuration during dynamic nonlinear analyses was observed. The steel consumption was estimated for each considered configuration.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Miller, D. B., R. G. Stockton y C. W. Krueger. "An inverted approach to configuration management". ACM SIGSOFT Software Engineering Notes 14, n.º 7 (noviembre de 1989): 1–4. http://dx.doi.org/10.1145/73337.73338.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Meynerd Rafael, Jusuf Wilson y Alva Yuventus Lukas. "COMPARISON STUDY OF BRACING CONFIGURATION WITH SHEAR LINK IN ECCENTRICALLY BRACED FRAME STEEL STRUCTURE". Journal Innovation of Civil Engineering (JICE) 1, n.º 1 (2 de noviembre de 2020): 7. http://dx.doi.org/10.33474/jice.v1i1.9058.

Texto completo

Resumen

The EBF structural system is identified by the use of bracing and link beams as components that work to receive lateral seismic loads. The position of the link beam makes the EBF system have several choices of bracing configuration; D-Braces, Split K-Braces, V-Braces, Split K & Inverted Split K-Braces, Inverted Y-Braces. Structural analysis was carried out on a 10-story building model for the EBF system with different type of bracing configurations using the ETABS software. All models analyzed according to Indonesian Code (SNI 1729:2015 and SNI 1726:2019) to obtain the structural element. Seismic analysis uses the response spectrum analysis method to obtain the structural response parameters in the EBF system. Result of the analysis for all of bracing configuration are shown that Split K-Braces model has the best response parameters when compared to the MRF system. The lowest value for the parameter is owned by Inverted Y-Braces, although overall it is still larger than the MRF system. The bracing configuration greatly affects the response of EBF system due to the behavior that occurs in the link beam, therefore the selection for type of bracing configuration is also important in the EBF system structure design.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Gok, K. y S. Inal. "Biomechanical comparison using finite element analysis of different screw configurations in the fixation of femoral neck fractures". Mechanical Sciences 6, n.º 2 (9 de septiembre de 2015): 173–79. http://dx.doi.org/10.5194/ms-6-173-2015.

Texto completo

Resumen

Abstract. In this research, biomechanical behaviors of five different configurations of screws used for stabilization of femoral neck fracture under axial loading have been examined, and which configuration is best has been investigated. A point cloud was obtained after scanning the human femoral model with a three dimensional (3-D) scanner, and this point cloud was converted to a 3-D femoral model by Geomagic Studio software. Femoral neck fracture was modeled by SolidWorks software for five different configurations: dual parallel, triple parallel, triangle, inverted triangle and square, and computer-aided numerical analysis of different configurations were carried out by ANSYS Workbench finite element analysis (FEA) software. For each configuration, mesh process, loading status (axial), boundary conditions and material model were applied in finite element analysis software. Von Mises stress values in the upper and lower proximity of the femur and screws were calculated. According to FEA results, it was particularly advantageous to use the fixation type of triangle configuration. The lowest values are found as 223.32 MPa at the lower, 63.34 MPa at the upper proximity and 493.24 MPa at the screws in triangle configuration. This showed that this configuration creates minimum stress at the upper and lower proximity of the fracture line. Clinically, we believe that the lowest stress values which are created by triangle configuration encompass the most advantageous method. In clinical practices, it is believed that using more than three screws does not provide any benefit. Furthermore, the highest stresses are as follows: at upper proximity 394.79 MPa in triple parallel configuration, for lower proximity 651.2 MPa in square configuration and for screw 2459 MPa in inverted triangle.

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Dziubiński, Adam. "CFD Analysis of the Tractor Propulsion Concepts for an Inverted Joined Wing Airplane". Transactions on Aerospace Research 2020, n.º 2 (1 de junio de 2020): 13–26. http://dx.doi.org/10.2478/tar-2020-0007.

Texto completo

Resumen

AbstractEfficiency is a crucial parameter for an airplane to reduce both cost of operations and emission of pollutants. There are several airplane concepts that potentially allow for increasing the efficiency. A few of them were not investigated thoroughly enough yet. The inverted joined wing configuration, with the upper wing in front of the lower one is an example of such concept. Therefore, a project consisting of development of an experimental scaled demonstrator, and its wind tunnel and flight testing, was undertaken by consortium: Institute of Aviation, Warsaw University of Technology, Air Force Institute of Technology and a MSP company. Results led to a conclusion, that the inverted joined wing configuration allows to build an airplane with excellent performance, but its advantage against the conventional airplane is marginal because of large trimming drag of the configuration with relatively high position of the thrust vector in pusher configuration. It was applied because the demonstrator was a flying model of manned airplane and the tractor configuration would affect the pilot’s field of observation. However, in case of the UAV, this reason becomes insignificant. Therefore two configurations of tractor propulsion were tested to see, if their performance is better than the performance of original design.

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Li, Jiantao, Menglin Wang, Jianfeng Zhou, Lin Han, Hao Zhang, Chen Li, Lianting Li y Ming Hao. "Optimum Configuration of Cannulated Compression Screws for the Fixation of Unstable Femoral Neck Fractures: Finite Element Analysis Evaluation". BioMed Research International 2018 (9 de diciembre de 2018): 1–10. http://dx.doi.org/10.1155/2018/1271762.

Texto completo

Resumen

Objectives. In the present study, we evaluated the mechanical outcome of different configurations of cannulated compression screws for the fixation of Pauwels type III femoral neck fracture and the stress distribution around the holes corresponding to fixation protocol after screws removal. Methods. The Pauwels type III of femoral neck fracture was created in 3-matic software and the models of cannulated compression screws were constructed using UG-NX software. Five fixation systems were assembled to the fracture models. Abaqus software was used to perform the process of finite element analysis. Values of stress distribution, maximum stress, model principal strains of proximal fragment, and stress distribution around the holes of femur model were recorded. Results. Stress of cannulated compression screws was intensely focused on the middle area of the screw near the fragment of each group. Inverted triangle model showed the highest peak stress on screws under different phases of load. Each screw dispersed some stresses, but at least one underwent the peak stress. Fracture model fixed by inverted triangle configuration showed the lowest volume of yielding strain in the proximal fragment. The area of higher stress around the holes was largest after triangle screws removal when compared with other four models. Conclusions. Our study indicated that different cannulated compression screws fixation configurations for the unstable femoral neck fractures showed the different mechanical efficiency. Inverted triangular configuration showed the mechanical advantage and being less likely to cutout. The fixation strategy of triangle configuration was least recommended if patients tended to remove the implants.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Zhang, Fujun, Xiaowei Xu, Weihua Tang, Jian Zhang, Zuliang Zhuo, Jian Wang, Jin Wang, Zheng Xu y Yongsheng Wang. "Recent development of the inverted configuration organic solar cells". Solar Energy Materials and Solar Cells 95, n.º 7 (julio de 2011): 1785–99. http://dx.doi.org/10.1016/j.solmat.2011.02.002.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Sensoz, Ersin, Fatih Mehmet Özkal, Volkan Acar y Ferit Cakir. "Finite element analysis of the impact of screw insertion distal to the trochanter minor on the risk of iatrogenic subtrochanteric fracture". Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 232, n.º 8 (20 de julio de 2018): 807–18. http://dx.doi.org/10.1177/0954411918789963.

Texto completo

Resumen

Iatrogenic subtrochanteric fractures are rarely encountered after cannulated screw fixation of femoral neck fractures; however, when they do occur, there can be several complications. Many orthopedic surgeons have concerns about the potential for iatrogenic subtrochanteric fractures after screw fixation distal to the trochanter minor; therefore, some surgeons are typically reluctant to perform this procedure. This study focused on the risk of an iatrogenic subtrochanteric fracture after treating femoral neck fractures with cannulated screws. The main purpose of the study was to understand iatrogenic subtrochanteric fractures and evaluate the effects on these fractures of an inverted triangular–shaped configuration for placement of the cannulated screws. A femur bone with an femoral neck fracture at a 40° incline to the horizontal plane was generated along with a representation of a three-dimensional finite element model, and three inverted triangular–shaped configurations for placement of the cannulated screws were investigated using finite element analyses. Statistical results indicated that the occurrence risk of ISF increases when the screw is located distal to the trochanter minor. Moreover, the risk of occurrence of intertrochanteric fracture increases when the screw is located medial to the trochanter minor because of local concentrated stress on the surface of the screw canals. To avoid the vulnerability of the subtrochanteric region, it was found that proximal placement of the screws using the inverted triangular–shaped configuration could yield better results. In addition, the results of this study provide suggestions on improved screw configurations.

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Trentin, João Francisco Silva, Tiago Peghin Cenale, Samuel da Silva y Jean Marcos de Souza Ribeiro. "Attitude control of inverted pendulums using reaction wheels: Comparison between using one and two actuators". Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 234, n.º 3 (29 de junio de 2019): 420–29. http://dx.doi.org/10.1177/0959651819857643.

Texto completo

Resumen

The attitude control using reaction wheels as actuators has been one of the most popular ways to stabilize and repel external disturbances in aerospace devices. From the controlled change of the angular momentum rate of change using reaction wheels, it is possible to control the oscillation and direction rates of change of rigid bodies in space. Thus, the main idea of this article is to present a case study with different configurations of the well-known reaction wheel pendulum. The first is based on the classical configuration, and the second, a new one, a pendulum with two reaction wheels. For both configurations, proportional–integral–derivative controllers were designed and experimental devices were built to perform real-time controllers using low-cost hardware. The simulated and experimental results have shown that the pendulums were controlled using a simple controller in the inverted position and the results were satisfactory. Four performance indices were calculated to evaluate the results for each configuration. They showed that the pendulum with two reaction wheels worked better than the pendulum with one reaction wheel. Two actuators made it easier to move and control the pendulum in the inverted position.

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Sader, John E., Cecilia Huertas-Cerdeira y Morteza Gharib. "Stability of slender inverted flags and rods in uniform steady flow". Journal of Fluid Mechanics 809 (21 de noviembre de 2016): 873–94. http://dx.doi.org/10.1017/jfm.2016.691.

Texto completo

Resumen

Cantilevered elastic sheets and rods immersed in a steady uniform flow are known to undergo instabilities that give rise to complex dynamics, including limit cycle behaviour and chaotic motion. Recent work has examined their stability in an inverted configuration where the flow impinges on the free end of the cantilever with its clamped edge downstream: this is commonly referred to as an ‘inverted flag’. Theory has thus far accurately captured the stability of wide inverted flags only, i.e. where the dimension of the clamped edge exceeds the cantilever length; the latter is aligned in the flow direction. Here, we theoretically examine the stability of slender inverted flags and rods under steady uniform flow. In contrast to wide inverted flags, we show that slender inverted flags are never globally unstable. Instead, they exhibit bifurcation from a state that is globally stable to multiple equilibria of varying stability, as flow speed increases. This theory is compared with new and existing measurements on slender inverted flags and rods, where excellent agreement is observed. The findings of this study have significant implications to investigations of biological phenomena such as the motion of leaves and hairs, which can naturally exhibit a slender geometry with an inverted configuration.

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Chapman, Talia, Dennis P. Martin, Christopher Williamson, Brian Tinsley, Mark L. Wang y Asif M. Ilyas. "Mini C-Arm Fluoroscopy: Does Its Configuration Matter for Radiation Exposure to the Surgeon?" HAND 13, n.º 5 (23 de junio de 2017): 552–57. http://dx.doi.org/10.1177/1558944717715139.

Texto completo

Resumen

Background: The risk of occupational radiation exposure to the surgeon associated with the use of a mini C-arm has yet to reach a wide consensus. Using a distal radius fracture surgery model, we tested the hypothesis that radiation exposure to the surgeon’s critical body parts is independent of mini C-arm configuration. Methods: An anthropomorphic mannequin (representing the upper body of a 60” male surgeon) was seated at a hand table as if operating on a volar-plated wrist Sawbone model. Thermoluminescent dosimeters measured radiation exposure to the surgeon’s eyes, thyroid, chest, hand, and groin from a mini C-arm fluoroscopy unit in 3 commonly used configurations: vertical (source above table), inverted (source below table), and horizontal (with beam parallel to table surface). The fluoroscope scanned the wrist model for 15 continuous minutes in triplicate for each orientation. Results: Radiation to the hand was significantly greatest in all mini C-arm positions compared with all other anatomic sites irrespective of C-arm position. Hand radiation exposure was greatest in the horizontal position (2887.09 mrem), versus the vertical and inverted positions (59.79 mrem, 31.10 mrem, P < .001). Eye radiation exposure was significantly greater in the inverted position (2.33 mrem) compared with the vertical (0.67 mrem, P = .024), and horizontal positions (0.33 mrem, P = .012). No significant difference in radiation exposure was found at the thyroid, chest, and groin sites, at each of the 3 C-arm configurations. Conclusions: The model’s hand received almost 1000 times more radiation exposure than all other anatomic sites with statistically greatest radiation exposure sustained in the horizontal position. Eye radiation exposure with the C-arm in the inverted position (below the table) was also significantly greater.

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Das, Saikat, Wenjin Xu, Hans-Joachim Lehmler, Anne-Frances Miller, Barbara L. Knutson y Stephen E. Rankin. "Inverted Micelle-in-Micelle Configuration in Cationic/Carbohydrate Surfactant Mixtures". ChemPhysChem 18, n.º 1 (11 de noviembre de 2016): 79–86. http://dx.doi.org/10.1002/cphc.201600908.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Young, Andrew W., Deborah Hellawell y Dennis C. Hay. "Configurational Information in Face Perception". Perception 16, n.º 6 (diciembre de 1987): 747–59. http://dx.doi.org/10.1068/p160747.

Texto completo

Resumen

A new facial composites technique is demonstrated, in which photographs of the top and bottom halves of different familiar faces fuse to form unfamiliar faces when aligned with each other. The perception of a novel configuration in such composite stimuli is sufficiently convincing to interfere with identification of the constituent parts (experiment 1), but this effect disappears when stimuli are inverted (experiment 2). Difficulty in identifying the parts of upright composites is found even for stimuli made from parts of unfamiliar faces that have only ever been encountered as face fragments (experiment 3). An equivalent effect is found for composites made from internal and external facial features of well-known people (experiment 4). These findings demonstrate the importance of configurational information in face perception, and that configurations are only properly perceived in upright faces.

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Blachnik, Roger y Kerstin Hackmann. "β-P4S3-Hydride: Eine NMR-Untersuchung / β-P4S3-Hydrides: An NMR Study". Zeitschrift für Naturforschung B 50, n.º 6 (1 de junio de 1995): 884–88. http://dx.doi.org/10.1515/znb-1995-0608.

Texto completo

Resumen

β-Tetraphosphorus-trichalcogenide hydrides have been detected in the reaction mixtures of β-P4S3X2 (X = Cl, Br, I) with (CH3)3SnH in CS2 solutions. In the first step of the reaction the configuration of the hydrogen accepting phosphorus atom is inverted and the compound β-P4S3XexoHendo is formed, as the main product. Two further isomers β-P4S3ClexoHexo and β- P4S3HexoHendo w ere found in low concentrations. The second nucleophilic substitution is slow and the configuration at the second hydrogenated phosphorus atom can be retain ed or inverted. Two products, β-P4S3HexoHendo and β -P4S3(Hendo)2, are observed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Sieradzki, Adam, Adam Dziubiński y Cezary Galiński. "Performance Comparison of the Optimized Inverted Joined Wing Airplane Concept and Classical Configuration Airplanes". Archive of Mechanical Engineering 63, n.º 3 (1 de septiembre de 2016): 455–70. http://dx.doi.org/10.1515/meceng-2016-0026.

Texto completo

Resumen

Abstract The joined wing concept is an unconventional airplane configuration, known since the mid-twenties of the last century. It has several possible advantages, like reduction of the induced drag and weight due to the closed wing concept. The inverted joined wing variant is its rarely considered version, with the front wing being situated above the aft wing. The following paper presents a performance prediction of the recently optimized configuration of this airplane. Flight characteristics obtained numerically were compared with the performance of two classical configuration airplanes of similar category. Their computational fluid dynamics (CFD) models were created basing on available documentation, photographs and some inverse engineering methods. The analysis included simulations performed for a scale of 3-meter wingspan inverted joined wing demonstrator and also for real-scale manned airplanes. Therefore, the results of CFD calculations allowed us to assess the competitiveness of the presented concept, as compared to the most technologically advanced airplanes designed and manufactured to date. At the end of the paper, the areas where the inverted joined wing is better than conventional airplane were predicted and new research possibilities were described.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

khlouf Munzer, Mohamad, Saidatul Norlyana Azemi, Azremi Abdullah Al-Hadi, Ping Jack Soh y Mohd Faizal Jamlos. "Dual Band Planar Inverted F Antenna (PIFA) with L-Shape Configuration". MATEC Web of Conferences 140 (2017): 01019. http://dx.doi.org/10.1051/matecconf/201714001019.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Salvadori, M. C., F. S. Teixeira, L. G. Sgubin, W. W. R. Araujo, R. E. Spirin, M. Cattani, E. M. Oks y I. G. Brown. "Gold ion implantation into alumina using an “inverted ion source” configuration". Review of Scientific Instruments 85, n.º 2 (febrero de 2014): 02B502. http://dx.doi.org/10.1063/1.4824755.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Christopher Litten, J., Carl Epple y Christian J. Leumann. "Bicyclo-oligonucleotides with inverted configuration at C(5′): synthesis and properties". Bioorganic & Medicinal Chemistry Letters 5, n.º 12 (junio de 1995): 1231–34. http://dx.doi.org/10.1016/0960-894x(95)00201-4.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Hill, Caleb M. y Shanlin Pan. "Efficient Analysis of Single Molecule Spectroscopic Data via MATLAB". MRS Proceedings 1493 (21 de diciembre de 2012): 309–14. http://dx.doi.org/10.1557/opl.2012.1676.

Texto completo

Resumen

ABSTRACTA MATLAB program is developed to help analyze single molecule spectroscopic data obtained with a standard inverted optical microscope. The described software has provisions to mitigate the effects of high background signals present in such data sets and greatly streamlines their analysis. Efficient single molecule image analysis and statistical blinking analysis are enabled with these programs to support single molecule imaging in an inverted configuration.

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Xie, Ya, Qiongxuan Tan, Zhitao Zhang, Kuankuan Lu, Miaozi Li, Wei Xu, Donghuan Qin, Yangdong Zhang, Lintao Hou y Hongbin Wu. "Improving performance in CdTe/CdSe nanocrystals solar cells by using bulk nano-heterojunctions". Journal of Materials Chemistry C 4, n.º 27 (2016): 6483–91. http://dx.doi.org/10.1039/c6tc01571a.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Yin, Xinxing, Scott A. McClary, Zhaoning Song, Dewei Zhao, Brian Graeser, Changlei Wang, Niraj Shrestha et al. "A Cu3PS4 nanoparticle hole selective layer for efficient inverted perovskite solar cells". Journal of Materials Chemistry A 7, n.º 9 (2019): 4604–10. http://dx.doi.org/10.1039/c8ta12100a.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Freire, Alejo, Kang Lee y Lawrence A. Symons. "The Face-Inversion Effect as a Deficit in the Encoding of Configural Information: Direct Evidence". Perception 29, n.º 2 (febrero de 2000): 159–70. http://dx.doi.org/10.1068/p3012.

Texto completo

Resumen

We report four experiments leading to conclusions that: (i) the face-inversion effect is mainly due to the deficits in processing of configural information from inverted faces; and (ii) this effect occurs primarily at the encoding stage of face processing, rather than at the storage stage. In experiment 1, participants discriminated upright faces differing primarily in configuration with 81% accuracy. Participants viewing the same faces presented upside down scored only 55%. In experiment 2, the corresponding discrimination rates for faces differing mainly in featural information were 91% (upright) and 90% (inverted). In experiments 3 and 4, the same faces were used in a memory paradigm. In experiment 3, a delayed matching-to-sample task was used, in which upright-face pairs differed either in configuration or features. Recognition rates were comparable to those for the corresponding upright faces in the discrimination tasks in experiments 1 and 2. However, there was no effect of delay (1 s, 5 s, or 10 s). In experiment 4, we repeated experiment 3, this time with inverted faces. Results were comparable to those of inverted conditions in experiments 1 and 2, and again there was no effect of delay. Together these results suggest that an ‘encoding bottleneck’ for configural information may be responsible for the face-inversion effect in particular, and memory for faces in general.

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Yamamuro, Kazuyuki, Minoru Tachiki y Takeshi Kobayashi. "Pt/SrBi4Ti4O15/Si-MOS system: preliminary study employing an inverted MOS configuration". Materials Science and Engineering: B 41, n.º 1 (octubre de 1996): 174–77. http://dx.doi.org/10.1016/s0921-5107(96)01647-9.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Monllau, Juan C., Juan I. Erquicia, Federico Ibañez, Maximiliano Ibañez, Pablo E. Gelber, Angel Masferrer-Pino y Xavier Pelfort. "Open-Wedge Valgus High Tibial Osteotomy Technique With Inverted L-Shaped Configuration". Arthroscopy Techniques 6, n.º 6 (diciembre de 2017): e2161-e2167. http://dx.doi.org/10.1016/j.eats.2017.08.009.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Li, Dan, Shuangfeng Wang y Qiang Wang. "Experimental Investigation of Buoyant Laminar Jet Diffusion Flames in an Inverted Configuration". Microgravity Science and Technology 30, n.º 6 (18 de agosto de 2018): 877–83. http://dx.doi.org/10.1007/s12217-018-9647-0.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Galinski, Cezary, Grzegorz Krysztofiak, Marek Miller, Pawel Ruchala, Marek Kalski, Mateusz Lis, Adam Dziubinski, Krzysztof Bogdanski, Lukasz Stefanek y Jaroslaw Hajduk. "Wind tunnel tests of the inverted joined wing and a comparison with CFD results". Aircraft Engineering and Aerospace Technology 90, n.º 4 (8 de mayo de 2018): 586–601. http://dx.doi.org/10.1108/aeat-11-2016-0195.

Texto completo

Resumen

Purpose The purpose of this paper is to present the methodology and approach adapted to conduct a wind tunnel experiment on the inverted joined-wing airplane flying model together with the results obtained. Design/methodology/approach General assumptions underlying the dual-use model design are presented in this paper. The model was supposed to be used for both wind tunnel tests and flight tests that significantly drive its size and internal structure. Wind tunnel tests results compared with the outcome of computational fluid dynamics (CFD) were used to assess airplane flying qualities before the maiden flight was performed. Findings Extensive data about the aerodynamic characteristics of the airplane were collected. Clean configurations in symmetric and asymmetric cases and also configurations with various control surface deflections were tested. Practical implications The data obtained experimentally made it possible to predict the performance and stability properties of the unconventional airplane and to draw conclusions on improvements in further designs of this configuration. Originality/value The airplane described in this paper differs from frequently analyzed joined-wing configurations, as it boasts a front lifting surface attached at the top of the fuselage, whereas the aft one is attached at the bottom. The testing technique involving the application of a dual-use model is also innovative.

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Bayram, Atilla, Firat Kara y Mehmet Nuri Almali. "Design of Spatial Inverted Pendulum System". MATEC Web of Conferences 291 (2019): 02004. http://dx.doi.org/10.1051/matecconf/201929102004.

Texto completo

Resumen

Pendulum-based systems which are highly non-linear and unstable have become one of the most widely studied subject of control theory. The close interest of researchers on inverted pendulum problem arises from its strong representation ability with real engineering applications. This study focuses on the design and production of an experimental setup in which a spatial inverted pendulum can be balanced by means of a planar mechanism in RRRRP configuration. A mechanism with two different motion inputs (rotational and linear) that no studies were performed on before was prototyped. This system is highly unstable and shows non-linear dynamic behavior. The mechanical parts that forms the system were manufactured by a 3D printer and a CNC milling machine. At the end of study, a four-degree of freedom spatial inverted pendulum experimental setup has been established on which the control works can be carried out, by installing the electronic and electro-mechanical equipment.

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Carnate, Jose. "Inverted Ductal Papilloma of the Salivary Gland". Philippine Journal of Otolaryngology Head and Neck Surgery 36, n.º 1 (30 de mayo de 2021): 67. http://dx.doi.org/10.32412/pjohns.v36i1.1663.

Texto completo

Resumen

This is a case consult of slides stated to be from an excision of a buccal mucosa mass in a 58-year-old-man. The specimen was described as a 3 cm diameter roughly oval tan-gray tissue with a 2 x 1.5 cm mucosal ellipse on the surface that has a central ulcerated punctum. Cut section showed an underlying 1.7 cm diameter roughly oval well-circumscribed mass with a granular tan surface. Histological sections show a papillary lesion with an orifice on the mucosal surface and with epithelial nests invaginating into the underlying lamina propria in a non-infiltrative pattern. (Figure 1) The lesion is composed of papillary epithelial fronds with cleft-like spaces between the fronds. (Figure 2) The papillary fronds are lined by non-keratinizing basaloid stratified squamous cells with a superficial layer of columnar glandular cells along with mucous goblet cells interspersed among the squamous cells. (Figure 3) All the cellular components are devoid of cytologic atypia and mitoses. Based on these microscopic features we signed the case out as inverted ductal papilloma (IDP). Ductal papillomas are uncommon benign epithelial tumors with a papillary configuration that originate from the excretory ductal system of salivary gland acini.1-3 The World Health Organization recognizes two sub-types depending on the growth pattern: an intraductal papilloma (IP) and an IDP.1 An IDP usually presents as an asymptomatic submucosal nodule, measuring about 1.5 centimeters in diameter, and most commonly involving the buccal mucosa, followed by the lips, palate, and floor of the mouth.2,3 Histological sections typically show an unencapsulated though well-circumscribed epithelial proliferation with a papillary configuration on the luminal surface, and a nodular, endophytic or invaginating (“inverted”) configuration at its interface with the underlying lamina propria.2 Both the papillary and the invaginating areas are composed of basaloid, non-keratinizing stratified squamous epithelium that are often covered with a cuboidal or columnar ductal cell layer.2 Scattered among these are mucous goblet cells which can form microcysts.1,2 There is an overall morphological similarity to the sinonasal inverted papilloma.3 A relationship to trauma has been proposed.1,4 Association with Human Papilloma Virus (HPV) has also been reported.1 Others, however, have not been able to demonstrate this association.4 Differential diagnoses primarily include IP - which is differentiated from IDP architecturally by being a unicystic intraluminal papillary proliferation within a dilated excretory duct 2 – and sialadenoma papilliferum – which is predominantly polypoid and pedunculated with a verrucoid surface rather than a submucosal nodule, and an over-all morphologic similarity to the cutaneous tumor syringocystadenoma papilliferum.1,4 An important differential diagnosis that has to be ruled out is mucoepidermoid carcinoma (MECA) because of the presence of both squamous and mucin-secreting cells. MECA is distinguished by poor circumscription, and an infiltrative solid-cystic growth pattern.2,4 IDP is benign and non-recurrent. Unlike the nasal tumor, there has been no report of malignant transformation.2,3 Complete surgical excision is considered curative.1,2 Reporting these cases is encouraged to further our knowledge of the entity and elucidate a potential association with HPV.

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Toledo, Rafael Cardoso, Chen Y. An, Irajá Newton Bandeira y Filipe Estevão de Freitas. "The Influence of Gravity on Eutectic PbSn Alloy Grown by the Vertical Bridgman Method". Materials Science Forum 869 (agosto de 2016): 637–42. http://dx.doi.org/10.4028/www.scientific.net/msf.869.637.

Texto completo

Resumen

Composition profiles of eutectic alloy Pb25.9Sn74.1 atomic % grown by the normal and inverted Bridgman methods are presented and the study of the solute alloy redistribution is made. The inverted vertical Bridgman method, where the solidification occurs from the top to the bottom of the melt under a destabilizing thermal gradient, allows the growth of crystals with buoyancy-driven convection different from that with the usual vertical Bridgman configuration. The scope of this work is to study the influence of the gravity acceleration in the convection process.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Wang, Qun, Sicao Yu, Wei Qin y Xiaohong Wu. "Isopropanol-assisted synthesis of highly stable MAPbBr3/p-g-C3N4 intergrowth composite photocatalysts and their interfacial charge carrier dynamics". Nanoscale Advances 2, n.º 1 (2020): 274–85. http://dx.doi.org/10.1039/c9na00634f.

Texto completo

Resumen

Isopropanol-assisted synthesis MAPbBr₃ wrapped/entrapped p-g-C₃N₄ intergrowth microcrystals have inverted type-I core/shell band configuration which leads to enhanced interfacial charge transfer and molecular oxygen activation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Spellings, Matthew, Michael Engel, Daphne Klotsa, Syeda Sabrina, Aaron M. Drews, Nguyen H. P. Nguyen, Kyle J. M. Bishop y Sharon C. Glotzer. "Shape control and compartmentalization in active colloidal cells". Proceedings of the National Academy of Sciences 112, n.º 34 (7 de agosto de 2015): E4642—E4650. http://dx.doi.org/10.1073/pnas.1513361112.

Texto completo

Resumen

Small autonomous machines like biological cells or soft robots can convert energy input into control of function and form. It is desired that this behavior emerges spontaneously and can be easily switched over time. For this purpose we introduce an active matter system that is loosely inspired by biology and which we term an active colloidal cell. The active colloidal cell consists of a boundary and a fluid interior, both of which are built from identical rotating spinners whose activity creates convective flows. Similarly to biological cell motility, which is driven by cytoskeletal components spread throughout the entire volume of the cell, active colloidal cells are characterized by highly distributed energy conversion. We demonstrate that we can control the shape of the active colloidal cell and drive compartmentalization by varying the details of the boundary (hard vs. flexible) and the character of the spinners (passive vs. active). We report buckling of the boundary controlled by the pattern of boundary activity, as well as formation of core–shell and inverted Janus phase-separated configurations within the active cell interior. As the cell size is increased, the inverted Janus configuration spontaneously breaks its mirror symmetry. The result is a bubble–crescent configuration, which alternates between two degenerate states over time and exhibits collective migration of the fluid along the boundary. Our results are obtained using microscopic, non–momentum-conserving Langevin dynamics simulations and verified via a phase-field continuum model coupled to a Navier–Stokes equation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Park, Kibeom, Jingon Joung, Sungjoon Lim y Han Lim Lee. "A Compact Crossed Inverted-V Antenna with a Common Reflector for Polarization Diversity in the IoT". Electronics 8, n.º 6 (6 de junio de 2019): 637. http://dx.doi.org/10.3390/electronics8060637.

Texto completo

Resumen

This article presented a compact and high gain antenna with reconfigurable polarization based on two inverted-V dipoles fabricated in a crossed configuration, and with a common planar reflector. The proposed antenna could generate four different types of polarizations, such as vertical polarization (VP), horizontal polarization (HP), right-hand circular polarization (RHCP), and left-hand circular polarization (LHCP). A pair of inverted-V dipoles drove the polarization diversity, where each dipole had an integrated matching circuit and a microstrip balun. Using a crossed inverted-V configuration with a ground plane as the common reflector, we could achieve compactness in size, high directivity, and a wider beamwidth than a normal dipole antenna. To verify the performance of the proposed antenna, we fabricated a sub-6GHz antenna with a Taconic TLX-9 substrate, which had a relative permittivity of 2.5. The proposed antenna showed a measured 10-dB impedance bandwidth of 752 MHz (5.376 GHz to 6.128 GHz). The peak gains for the VP, HP, RHCP and LHCP operations at 5.8 GHz were about 5.2 dBi, 4.61 dBi, 5.25 dBic, and 5.51 dBic, respectively. In addition, the half-power beamwidth (HPBW) for all the polarizations were greater than 78° in the operation band.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Ohhara, Takashi, Hidehiro Uekusa, Yuji Ohashi, Ichiro Tanaka, Shintaro Kumazawa y Nobuo Niimura. "Direct observation of deuterium migration in crystalline-state reaction by single-crystal neutron diffraction. III. Photoracemization of 1-cyanoethyl cobaloxime complexes". Acta Crystallographica Section B Structural Science 57, n.º 4 (24 de julio de 2001): 551–59. http://dx.doi.org/10.1107/s0108768101006838.

Texto completo

Resumen

The H atoms bonded to the chiral C atoms (stereogenic center) of the 1-cyanoethyl groups in two cobalt complexes, [(R)-1-cyanoethyl]bis(dimethylglyoximato)(pyridine)cobalt(III) (2) and [(R,S)-1-cyanoethyl]bis(dimethylglyoximato)(piperidine)cobalt(III) (3), were replaced with D atoms, such as Co—C*D(CH3)CN. The crystals of the two cobalt complexes were irradiated with a xenon lamp for 72 h and 27 d, respectively. The unit-cell dimensions were gradually changed with retention of the single-crystal form. The crystal structures after irradiation were determined by neutron diffraction. In each crystal the chiral 1-cyanoethyl group of one of the two crystallographically independent molecules was partly inverted to the opposite configuration, whereas that of the other molecule kept the original configuration. The C*—D bond in the inverted group was completely conserved in the process of the inversion of the chiral alkyl group. This suggests that the inversion of the chiral 1-cyanoethyl group proceeds with the rotation of the cyanoethyl radical after the Co—C bond cleavage by photo-irradiation so that the opposite side of the radical faces the Co atom. This is followed by recombination of the Co—C bond to form the inverted 1-cyanoethyl group.

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Fan, Boyu, Cecilia Huertas-Cerdeira, Julia Cossé, John E. Sader y Morteza Gharib. "Effect of morphology on the large-amplitude flapping dynamics of an inverted flag in a uniform flow". Journal of Fluid Mechanics 874 (10 de julio de 2019): 526–47. http://dx.doi.org/10.1017/jfm.2019.474.

Texto completo

Resumen

The stability of a cantilevered elastic sheet in a uniform flow has been studied extensively due to its importance in engineering and its prevalence in natural structures. Varying the flow speed can give rise to a range of dynamics including limit cycle behaviour and chaotic motion of the cantilevered sheet. Recently, the ‘inverted flag’ configuration – a cantilevered elastic sheet aligned with the flow impinging on its free edge – has been observed to produce large-amplitude flapping over a finite band of flow speeds. This flapping phenomenon has been found to be a vortex-induced vibration, and only occurs at sufficiently large Reynolds numbers. In all cases studied, the inverted flag has been formed from a cantilevered sheet of rectangular morphology, i.e. the planform of its elastic sheet is a rectangle. Here, we investigate the effect of the inverted flag’s morphology on its resulting stability and dynamics. We choose a trapezoidal planform which is explored using experiment and an analytical theory for the divergence instability of an inverted flag of arbitrary morphology. Strikingly, for this planform we observe that the flow speed range over which flapping occurs scales approximately with the flow speed at which the divergence instability occurs. This provides a means by which to predict and control flapping. In a biological setting, leaves in a wind can also align themselves in an inverted flag configuration. Motivated by this natural occurrence we also study the effect of adding an artificial ‘petiole’ (a thin elastic stalk that connects the sheet to the clamp) on the inverted flag’s dynamics. We find that the petiole serves to partially decouple fluid forces from elastic forces, for which an analytical theory is also derived, in addition to increasing the freedom by which the flapping dynamics can be tuned. These results highlight the intricacies of the flapping instability and account for some of the varied dynamics of leaves in nature.

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Kasal, Alexander, Milos̆ Budĕs̆ı́nský y Pavel Dras̆ar. "Analogues of androgen hormones with inverted configuration at carbons 5, 9, and 10". Steroids 67, n.º 1 (enero de 2002): 57–70. http://dx.doi.org/10.1016/s0039-128x(01)00135-0.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Courtney, Amy, Luke M. Alvey, George O. T. Merces, Niamh Burke y Mark Pickering. "The Flexiscope: a low cost, flexible, convertible and modular microscope with automated scanning and micromanipulation". Royal Society Open Science 7, n.º 3 (marzo de 2020): 191949. http://dx.doi.org/10.1098/rsos.191949.

Texto completo

Resumen

With technologies rapidly evolving, many research institutions are now opting to invest in costly, high-quality, specialized microscopes which are shared by many researchers. As a consequence, the user may not have the ability to adapt a microscope to their specific needs and limitations in experimental design are introduced. A flexible work-horse microscopy system is a valuable tool in any laboratory to meet the diverse needs of a research team and promote innovation in experimental design. We have developed the Flexiscope; a multi-functional, adaptable, efficient and high-performance microscopy/electrophysiology system for everyday applications in a neurobiology laboratory. The core optical components are relatively constant in the three configurations described here: an upright configuration, an inverted configuration and an upright/electrophysiology configuration. We have provided a comprehensive description of the Flexiscope. We show that this method is capable of oblique infrared illumination imaging, multi-channel fluorescent imaging and automated three-dimensional scanning of larger specimens. Image quality is conserved across the three configurations of the microscope, and conversion between configurations is possible quickly and easily, while the motion control system can be repurposed to allow sub-micrometre computer-controlled micromanipulation. The Flexiscope provides similar performance and usability to commercially available systems. However, as it can be easily reconfigured for multiple roles, it can remove the need to purchase multiple microscopes, giving significant cost savings. The modular reconfigurable nature allows the user to customize the system to their specific needs and adapt/upgrade the system as challenges arise, without requiring specialized technical skills.

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Eatherington, Carla J., Lieta Marinelli, Miina Lõoke, Luca Battaglini y Paolo Mongillo. "Local Dot Motion, Not Global Configuration, Determines Dogs’ Preference for Point-Light Displays". Animals 9, n.º 9 (6 de septiembre de 2019): 661. http://dx.doi.org/10.3390/ani9090661.

Texto completo

Resumen

Visual perception remains an understudied area of dog cognition, particularly the perception of biological motion where the small amount of previous research has created an unclear impression regarding dogs’ visual preference towards different types of point-light displays. To date, no thorough investigation has been conducted regarding which aspects of the motion contained in point-light displays attract dogs. To test this, pet dogs (N = 48) were presented with pairs of point-light displays with systematic manipulation of motion features (i.e., upright or inverted orientation, coherent or scrambled configuration, human or dog species). Results revealed a significant effect of inversion, with dogs directing significantly longer looking time towards upright than inverted dog point-light displays; no effect was found for scrambling or the scrambling-inversion interaction. No looking time bias was found when dogs were presented with human point-light displays, regardless of their orientation or configuration. The results of the current study imply that dogs’ visual preference is driven by the motion of individual dots in accordance with gravity, rather than the point-light display’s global arrangement, regardless their long exposure to human motion.

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Maus, Horst-Moritz y Andre Seyfarth. "Walking in circles: a modelling approach". Journal of The Royal Society Interface 11, n.º 99 (6 de octubre de 2014): 20140594. http://dx.doi.org/10.1098/rsif.2014.0594.

Texto completo

Resumen

Blindfolded or disoriented people have the tendency to walk in circles rather than on a straight line even if they wanted to. Here, we use a minimalistic walking model to examine this phenomenon. The bipedal spring-loaded inverted pendulum exhibits asymptotically stable gaits with centre of mass (CoM) dynamics and ground reaction forces similar to human walking in the sagittal plane. We extend this model into three dimensions, and show that stable walking patterns persist if the leg is aligned with respect to the body (here: CoM velocity) instead of a world reference frame. Further, we demonstrate that asymmetric leg configurations, which are common in humans, will typically lead to walking in circles. The diameter of these circles depends strongly on parameter configuration, but is in line with empirical data from human walkers. Simulation results suggest that walking radius and especially direction of rotation are highly dependent on leg configuration and walking velocity, which explains inconsistent veering behaviour in repeated trials in human data. Finally, we discuss the relation between findings in the model and implications for human walking.

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Zhang, Xi-an, Song-tao Qi, Jun Fan, Guang-long Huang y Jun-xiang Peng. "Arachnoid membranes in the posterior half of the incisural space: an inverted Liliequist membrane–like arachnoid complex". Journal of Neurosurgery 121, n.º 2 (agosto de 2014): 390–96. http://dx.doi.org/10.3171/2014.3.jns132206.

Texto completo

Resumen

Object The aim of this study was to describe the similarity of configuration between the arachnoid complex in the posterior half of the incisural space and the Liliequist membrane. Methods Microsurgical dissection and anatomical observation were performed in 20 formalin-fixed adult cadaver heads. The origin, distribution, and configuration of the arachnoid membranes and their relationships with the vascular structures in the posterior half of the incisural space were examined. Results The posterior perimesencephalic membrane and the cerebellar precentral membrane have a common origin at the tentorial edge and form an arachnoid complex strikingly resembling an inverted Liliequist membrane. Asymmetry between sides is not uncommon. If the cerebellar precentral membrane is hypoplastic on one side or both, the well-developed quadrigeminal membrane plays a prominent part in partitioning the subarachnoid space in the posterior half of the incisural space. Conclusions The arachnoid complex in the posterior half of the incisural space can be regarded as an inverted Liliequist membrane. This concept can help neurosurgeons to gain better understanding of the surgical anatomy at the level of the tentorial incisura.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Venkataprasad Bhat, S., A. Govindaraj y C. N. R. Rao. "Hybrid solar cell based on P3HT–ZnO nanoparticle blend in the inverted device configuration". Solar Energy Materials and Solar Cells 95, n.º 8 (agosto de 2011): 2318–21. http://dx.doi.org/10.1016/j.solmat.2011.03.047.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Hongwei, Wang, Bao Yun, Xin Yongna, Yang Xiaoqin, Shi Qian, Lu Daru, Qiu Xinfang y Xue Jinglun. "Construction and expression of inverted configuration of retroviral vector containing intron 1 of hFIX". Chinese Science Bulletin 43, n.º 4 (febrero de 1998): 315–18. http://dx.doi.org/10.1007/bf02884546.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Pichler, Paul, Maryam Dosani, Ipek Oruç y Jason J. S. Barton. "The nature of upright and inverted face representations: An adaptation-transfer study of configuration". Cortex 48, n.º 6 (junio de 2012): 725–36. http://dx.doi.org/10.1016/j.cortex.2011.02.005.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Mehedi, Ibrahim M., Uzair Ansari, Abdulrahman H. Bajodah, Ubaid M. AL-Saggaf, Belkacem Kada y Muhyaddin J. Rawa. "Underactuated rotary inverted pendulum control using robust generalized dynamic inversion". Journal of Vibration and Control 26, n.º 23-24 (20 de marzo de 2020): 2210–20. http://dx.doi.org/10.1177/1077546320916022.

Texto completo

Resumen

The article applies the robust generalized dynamic inversion control methodology to the problem of stabilizing upright equilibrium configuration of the under-actuated rotary inverted pendulum system while tracking rotary motion of the actuated arm. The proposed robust generalized dynamic inversion control law comprised equivalent and switching control parts. The equivalent control part works to enforce a virtual constraint dynamics of the controlled state variables by means of Moore–Penrose generalized inversion. The switching control part is of the sliding mode type, and it improves robustness against unmodeled system dynamics, parametric uncertainties, and external disturbances. The robust generalized dynamic inversion control design on the linearized model of the under-actuated rotary inverted pendulum is shown to guarantee semi-global asymptotically stable tracking performance. Numerous computer simulations and experiments are conducted on the Quanser rotary inverted pendulum system, revealing that the proposed algorithm has better convergence and tracking performance than conventional sliding mode and generalized dynamic inversion control strategies when both are applied separately.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Wosińska-Hrydczuk, Marzena, Przemysław J. Boratyński y Jacek Skarżewski. "Regioselective and Stereodivergent Synthesis of Enantiomerically Pure Vic-Diamines from Chiral β-Amino Alcohols with 2-Pyridyl and 6-(2,2′-Bipyridyl) Moieties". Molecules 25, n.º 3 (7 de febrero de 2020): 727. http://dx.doi.org/10.3390/molecules25030727.

Texto completo

Resumen

In this report, we describe the synthetic elaboration of the easily available enantiomerically pure β-amino alcohols. Attempted direct substitution of the hydroxyl group by azido-functionality in the Mitsunobu reaction with hydrazoic acid was inefficient or led to a diastereomeric mixture. These outcomes resulted from the participation of aziridines. Intentionally performed internal Mitsunobu reaction of β-amino alcohols gave eight chiral aziridines in 45–82% yield. The structural and configuration identity of products was confirmed by NMR data compared to the DFT calculated GIAO values. For 1,2,3-trisubstituted aziridines slow configurational inversion at the endocyclic nitrogen atom was observed by NMR at room temperature. Moreover, when aziridine was titrated with Zn(OAc)2 under NMR control, only one of two N-epimers directly participated in complexation. The aziridines underwent ring opening with HN3 to form the corresponding azido amines as single regio- and diastereomers in 90–97% yield. Different results were obtained for 1,2-disubstituted and 1,2,3-trisubstituted aziridines. For the later aziridines ring closure and ring opening occurred at different carbon stereocenters, thus yielding products with two inverted configurations, compared to the starting amino alcohol. The 1,2-disubstituted aziridines produced azido amines of the same configuration as the starting β-amino alcohols. To obtain a complete series of diastereomeric vic-diamines, we converted the amino alcohols into cyclic sulfamidates, which reacted with sodium azide in SN2 reaction (25–58% overall yield). The azides obtained either way underwent the Staudinger reduction, giving a series of six new chiral vic-diamines of defined stereochemistries.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Xi, Xiao-Dong, Da-Xin Shi, Hui Li, Yun-Zheng Li y Qin-Pei Wu. "4,5,6-Tri-O-acetyl-2,3-di-S-ethyl-2,3-dithio-D-allose diethyl dithioacetal". Acta Crystallographica Section E Structure Reports Online 65, n.º 6 (7 de mayo de 2009): o1227. http://dx.doi.org/10.1107/s1600536809015694.

Texto completo

Resumen

The title compound, C20H36O6S4, was obtained by ethanethiolysis of 3,5,6-tri-O-acetyl-1,2-O-isopropylidene-α-D-glucofuranose. One of the ethyl groups is disordered over two sites with refined occupancies of 0.869 (6) and 0.131 (6). Compared with the precursor, the absolute configuration of the stereocenters at positions C-3 and C-2 are inverted and maintained, respectively.

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Hashidoko, Yasuyuki, Satoshi Tahara y Junya Mizutani. "Novel Bisabolanoids In Rosa Rugosa Leaves". Zeitschrift für Naturforschung C 46, n.º 5-6 (1 de junio de 1991): 349–56. http://dx.doi.org/10.1515/znc-1991-5-604.

Texto completo

Resumen

Bisaborosaol A (1), a novel sesquiterpene belonging to the bisabolane class, was isolated from Rosa rugosa leaves. The absolute configuration of 1 at C-4 was shown to be inverted in comparison with bisabolanoids from Compositae. Bisaborosaol A (1) and its corresponding carboxylic acid (2) may be biogenetically related to the carotanoids which constitute the major sesquiterpenes of R. rugosa leaves

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Ferdinand, Niyonyungu, Zhao Jianchang, Yang Qiangqiang, Guobing Wang y Xu Junjie. "Research on Application of Buckling Restrained Braces in Strengthening of Concrete Frame Structures". Civil Engineering Journal 6, n.º 2 (1 de febrero de 2020): 344–62. http://dx.doi.org/10.28991/cej-2020-03091475.

Texto completo

Resumen

This paper examines the application of BRB in strengthening of reinforced concrete frame structures to meet seismic requirements according to Chinese seismic design code. Elastic response spectrum analysis and nonlinear time history analysis are performed by taking a real engineering example that suffers weak first floor irregularity due to added loads and addition of one floor. With the method of equivalent stiffness and displacement-based design method, buckling restrained brace parameters are deduced and are used to model BRB in ETABS using plastic wen model. Three configurations of buckling restrained braces are studied together with ordinary braces. Under elastic state, the relationship between the required cross section area of BRB and ordinary braces is deduced from the formula of calculating elastic bearing capacity where it is shown that the area of the ordinary braces must be 1.25 times that of BRB for ensuring the same performance. The results show that Inverted V brace configuration demonstrated better performance over single brace and V brace configurations and X brace configuration, although not recommended by Chinese code, is simulated and used in this paper and has demonstrated better performance over other configurations, and the further research on the practical use of this brace is recommended. Also, under action of strong earthquakes, by nonlinear time history analysis, buckling restrained braces demonstrated better performance of strengthening the structure and make it meet the requirement of code. Under this same condition, ordinary braces losses their bearing capacity due to excessive buckling.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Riss, Joëlle, Juan Luis Fernández-Martínez, Colette Sirieix, Ouassima Harmouzi, Antoine Marache y Ali Essahlaoui. "A methodology for converting traditional vertical electrical soundings into 2D resistivity models: Application to the Saïss basin, Morocco". GEOPHYSICS 76, n.º 6 (noviembre de 2011): B225—B236. http://dx.doi.org/10.1190/geo2010-0080.1.

Texto completo

Resumen

We demonstrated a simple methodology for the reinterpretation of sets of electrical vertical soundings and the production of 2D resistivity models. The method is applied to the northern central part of the subsiding Saïss basin (Morocco) where a series of vertical electrical soundings (VES) were acquired in 1982 and 1984, using the Schlumberger array with current electrodes semispacings between 3 and 3000 m. We describe a methodology used to estimate and sample apparent resistivities collected from traditional single soundings acquired by using a Schlumberger configuration. We then construct a resistivity pseudosection in a format compatible with a Wenner-Schlumberger array to perform 2D electrical tomography. The methodology takes into account the lateral and vertical spatial correlations shown by the apparent resistivities. The tomographic inversions are performed using a commercial inversion software commonly used in industry. Geostatistical tools are used to quantify the spatial correlation between apparent resistivity data. The result is a series of estimated pseudosections that are inverted to produce 2D resistivity models of the basin along geophysical profiles. We focus our attention on one of these profiles (i.e., one 2D resistivity model). The inverted geoelectrical model allows us to propose a geologic model of the basin. Our methodology allows historical and current data carried out using the Schlumberger configuration, to be rapidly reinterpreted in countries where only low-cost methods, such as VES soundings, can be used due to technology and economic constraints. It can also be applied to cases where continuous or pulled-array continuous vertical soundings method, where a tail of electrodes is towed behind a small vehicle while continuously and simultaneously measuring several electrode configurations, is inoperative due to field conditions (survey length, deep layers, and local environmental conditions).

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Gong, Shuli, Ancai Zhang, Jinhua She, Xinghui Zhang y Yuanyuan Liu. "Trajectory Design and Tracking Control for Nonlinear Underactuated Wheeled Inverted Pendulum". Mathematical Problems in Engineering 2018 (24 de septiembre de 2018): 1–10. http://dx.doi.org/10.1155/2018/6134764.

Texto completo

Resumen

An underactuated wheeled inverted pendulum (UWIP) is a nonlinear mechanical system that has two degrees of freedom and has only one control input. The motion planning problem for this nonlinear system is difficult to solve because of the existence of an uncontrollable manifold in the configuration space. In this paper, we present a method of designing motion trajectory for this underactuated system. The design of trajectory is based on the dynamic properties of the UWIP system. Furthermore, the tracking control of the UWIP for the constructed trajectory is also studied. A tracking control law is designed by using quadratic optimal control theory. Numerical simulation results verify the effectiveness of the presented theoretical results.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "Inverted configuration"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros