Structural control

Top PDF Structural control:

Editorial for Special Issue "Structural Control of Mineral Deposits: Theory and Reality"

Editorial for Special Issue "Structural Control of Mineral Deposits: Theory and Reality"

Sousa, J.A.B. Structural Control on Clay Mineral Authigenesis in Faulted Arkosic Sandstone of the Rio do Peixe Basin, Brazil. Minerals 2018, 8, 408. [ CrossRef ] 28. Sun, T.; Xu, Y.; Yu, X.; Liu, W.; Li, R.; Hu, Z.; Wang, Y. Structural Controls on Copper Mineralization in the Tongling Ore District, Eastern China: Evidence from Spatial Analysis. Minerals 2018, 8, 254. [ CrossRef ] 29. Aerden, D.G.A.M. Formation of Massive Sulfide Lenses by Replacement of folds: The Hercules Pb–Zn Mine,

5 En savoir plus

Structural control of chemoselectivity, stereoselectivity, and substrate specificity in membrane-bound fatty acid acetylenases and desaturases

Structural control of chemoselectivity, stereoselectivity, and substrate specificity in membrane-bound fatty acid acetylenases and desaturases

Desaturation to give trans double bonds co-occurs with acetylenase activity in Crep1. It is possible to argue that similar spatial accommodation of the substrates and products for the trans -desaturation and acetylenation reactions may explain this observation. trans desaturation likely requires the binding of oleate in an antiperiplanar conformation and accommodation of the relatively “linear” 18:2-9c,12t product. Similarly, although the substrate for acetylenation is cis at the active site, the product is linear from C11 to C14. It is notable, therefore, that effects on acetylenation and trans desaturation are correlated for positions 150, 183, and 259. The notable exception is the H266Q mutation. Relative to the wild type, acetylenation is much reduced in comparison to trans desaturation in this mutant. In fact, H266Q represents the “accidental engineering” of an enzyme with primarily oleate trans-Δ12 desaturase activity. This suggests that the structural control of the two activities is independent to some
En savoir plus

8 En savoir plus

Adaptive structural control

Adaptive structural control

An attempt is also made to combine AI technologies like neural networks, knowledge based systems, and fuzzy logic, with control theory in order to achieve an adaptive[r]

75 En savoir plus

Structural control of polyelectrolyte/microemulsion droplet complexes (PEMECs) with different polyacrylates

Structural control of polyelectrolyte/microemulsion droplet complexes (PEMECs) with different polyacrylates

One possible explanation for forming elongated complexes would be the transformation of many droplets into a cylinder with a diameter of one droplet. However, as mentioned before, the form factor minimum does not change, so the size and shape of the microemulsion droplets remain the same. Another way to form elongated complexes is by linking several droplets with polyelectrolyte chains in a cylindrical geometry. A comparison of the two models is given in Fig. S9,† showing the signicantly better agreement of the second model with the measured data. Accordingly, this model was used to describe the SANS data and to quantify the elongation. The structural parameters for single microemulsion droplets were xed to be those of the pure microemulsion sample. Additional parame- ters for the linear arrangement of the droplets are the number N of droplets per aggregate, the mean distance D between droplets in one aggregate and the polydispersity of this distance.
En savoir plus

14 En savoir plus

Confined in-fiber solidification and structural control of silicon and silicon−germanium microparticles

Confined in-fiber solidification and structural control of silicon and silicon−germanium microparticles

Here, a postbreakup particle is illuminated perpendicularly to the fiber axis by a focused diode laser beam at a wavelength of 808 nm, with a spot size of about 50 μm. To prevent the cracking of the cladding, which might occur as a result of the release of stresses stored in the silica cladding, we uniformly preheat and soften it with a CO 2 laser (Fig. 2A). The absorption length of silica and silicon at 808 nm is about 1.5 m and 12.5 μm, re- spectively. Therefore, the diode laser radiation is expected to be transmitted by the silica cladding but to be absorbed by the particle, which heats up. Once the particle is molten, the laser power is gradually reduced and the particle cools down and re- crystallizes, while exposed to a thermal gradient defined by the diode laser direction. The process is schematically represented in Fig. 2B. By controlling the laser shut-off rate, we can effectively control the cooling conditions and the magnitude of the imposed temperature gradient.
En savoir plus

16 En savoir plus

Design of a fluid elastic actuator with application to structural control

Design of a fluid elastic actuator with application to structural control

The pneumatic air-jet developed by Hallauer and Smith-used to damp a planar truss-expelled pressurized air to generate a force (i.e. used unspecified pneumatic actuators[r]

153 En savoir plus

Deep structural control on distribution of raised beaches and Quaternary sedimentation in Brittany? A review

Deep structural control on distribution of raised beaches and Quaternary sedimentation in Brittany? A review

This paper is a review of the possible influences of deep structures on Quaternary sedimentation and the distribution of raised beaches, a problem which has never been raised before in any paper. The distri- bution of the Quaternary outcrops is very patchy in Brittany and seems to be organized in a random way, partly because the control by the short wavelength basement structures is not easy to recognize but also because the most efficient control is associated with long wavelength structures which are far beyond the scale of the usual geological maps and the immediate observations. Gravity data and terrain-levelling give far better results than the other geophysical techniques when the Moho undulations are compared with the surficial data. The two main domains involved in the long wavelength deformations are (a) the Alpine domain where all the Moho undulations are concentric with the Alps; and (b) the Armorican domain in which all the undulations are westenorthwesteeastesoutheast oriented, parallel with the axis of the initial opening of the Bay of Biscay.
En savoir plus

7 En savoir plus

Structural control in micelles of alkyl acrylate-acrylate copolymers via alkyl chain length and block length

Structural control in micelles of alkyl acrylate-acrylate copolymers via alkyl chain length and block length

-46.86 -46.35 We studied polyacrylic acid-containing polymers with n-butyl, n-hexyl and n-dodecyl alkyl chain as 20% and 40%, to have a systematic variation of the hydrophobicity of polymers. Besides hydrophobicity, pH-dependency was also investigated via changing degrees of ionization α of 0.2 and 1.0 (to make sure about complete deprotonation of the polymer we worked here with an excess amount of NaOH, i.e. α was 1.2 for each fully deprotonated sample). For the structural characterization, static light scattering and small angle neutron scattering experiments were employed, which enables us to understand the mesoscopic organization of different aqueous solutions of synthesized polymer.
En savoir plus

31 En savoir plus

Structural control of collapse events inferred by self-potential mapping on the Piton de la Fournaise volcano (La Réunion Island)

Structural control of collapse events inferred by self-potential mapping on the Piton de la Fournaise volcano (La Réunion Island)

Corwin, R.F., 1997. The self-potential method for environmental and engineering appli- cations: geotechnical and environmental geophysics. In: Ward, H. (Ed.), Investiga- tions in Geophysics: Soc. Expl. Geophys, vol. 5, p. 1. Finizola, A., Lénat, J.-F., Macedo, O., Ramos, D., Thouret, J.-C., Sortino, F., 2004. Fluid cir- culation and structural discontinuities inside Misti volcano (Peru) inferred from self-potential measurements. Journal of Volcanology and Geothermal Research 135, 343–360.

11 En savoir plus

Broadband active structural control using collocated piezoelectric sensors and actuators

Broadband active structural control using collocated piezoelectric sensors and actuators

Heat was applied by placing a Watlow flexible heater to the opposite side of the panel (inside the testbed). The required pressure was applied by means of a typical [r]

105 En savoir plus

Conceptual design of adaptive structural control systems

Conceptual design of adaptive structural control systems

An attempt to use a simple solenoid to create forces large enough to be used in civil structures or even in maglev operations would require enormously large input[r]

148 En savoir plus

Placement of Piezoelectric Laminate Actuator for Active Structural Acoustic Control

Placement of Piezoelectric Laminate Actuator for Active Structural Acoustic Control

3.4 Placement strategy for structural control This technique addresses the problem of modal control. The aim is to select a minimal number of actuators that would control, as accurately as possible, the targeted modes. In the case of an actual structure, the procedure must take into account geometrical constraints that may limit the number of candidate locations. Assuming that sensors are placed at all candidate locations ( C is then fixed for comparison purpose only), the principle of the method is to compute, for each possible actuator location, the placement index σ ik . This index quantifies the excitation efficiency of the k th ( n n )
En savoir plus

14 En savoir plus

Structural tuning of organoruthenium compounds allows oxidative switch to control ER stress pathways and bypass multidrug resistance

Structural tuning of organoruthenium compounds allows oxidative switch to control ER stress pathways and bypass multidrug resistance

noteworthy that the structural tuning also impacted its ability to bypass cancer cell MDR mechanisms, as seen in the two-fold difference in the resistance factor between RAS-1H and RAS-1T. These factors should be taken into consideration when designing such compounds as anticancer agents to improve the treatment outcome for MDR cancers. Based on the current study, we hypothesized that the structural change to the RAS complexes could have affected the selectivity of binding to their target, especially if the cellular target contains several homol- ogous isoforms. This could have caused the observed differ- ences in the mode-of-action between the two complexes. Nevertheless, more studies are required to identify the cellular target(s) of RAS-1H and RAS-1T before this can be validated.
En savoir plus

9 En savoir plus

Structural safety

Structural safety

Today, most structures are designed by a more rational, direct method involving an understanding of Newtonian mechanics, external actions or loads acting on a structure, and material behaviour. The basic idea is to make the structure sufficiently strong to withstand the loads that will be applied to it. Loads and structural strength are, however, to some extent unpredictable and this is where the risk comes in. To reduce risk of collapse to an acceptable level, safety factors - ratios between calculated strength and applied loads - are introduced and stipulated in building codes and structural standards. Table II gives some of the safety factors used in the National Building Code of Canada 1970 (1). They have been arrived at primarily on the basis of experience, and have been gradually reduced over the years through improved knowledge and workmanship.
En savoir plus

7 En savoir plus

Optimization of primary flight control actuation system using parametric sizing models of actuators, power electronics and structural analysis

Optimization of primary flight control actuation system using parametric sizing models of actuators, power electronics and structural analysis

Department of Avionics and Actuation Safran Electronics & Defense ABSTRACT The design of aerospace actuation systems is an exciting challenge in terms of integration and performance requirements, engineering specializations, technological limits and numerical tools. The investigation of future flight control actuation system technologies and architectures has to evaluate the impact of new concepts on each subsystem in a tightly coupled manner. This paper presents an investigation of the effect of control surface splitting on an aileron using a Multidisciplinary System Design Optimization technique. The investigation is then extended to a primary flight control actuation system. Parametric sizing models help determine geometries and performances of rotary on hinge electromechanical actuator, associated power electronics and structural analysis. Promising preliminary results about effects of control surface splitting on aileron and on primary flight control surface layout are presented.
En savoir plus

8 En savoir plus

Adaptable structural surfaces

Adaptable structural surfaces

optimally, the radius of the column expands under the initial load relatively regularly over the entire height of the column, until the maximal load is being reached. [r]

56 En savoir plus

Décomposition de l'équilibre structural

Décomposition de l'équilibre structural

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignemen[r]

10 En savoir plus

Structural accessibility and structural observability of nonlinear networked systems

Structural accessibility and structural observability of nonlinear networked systems

Somewhat counter-intuitively, we find that nonlinearities render the problem of controlling or observing a networked system significantly easier. Specifically, for the class of non- linear systems with meromorphic dynamics, we prove that the conditions for nonlinear structural accessibility and observ- ability are essential in the sense that they are contained in the conditions for linear structural controllability and observabil- ity. In other words, the necessary and sufficient conditions for nonlinear meromorphic dynamics are only necessary and no longer sufficient for linear dynamics. The additional condition required for linear dynamics is rather “accidental” because it applies to the special subclass of linear dynamics. A direct consequence of this analysis is that the sets of driver and sensor nodes are smaller when compared to those necessary for linear structural controllability and linear structural observ- ability.
En savoir plus

12 En savoir plus

COST Action F3 on Structural Dynamics: Benchmarks for Structural Health Monitoring

COST Action F3 on Structural Dynamics: Benchmarks for Structural Health Monitoring

The final paper on the Z24 bridge was by Kul- laa [23] and was different in a number of ways. Al- though the features for damage detection were once more natural frequencies and modeshapes extracted from time-series by a stochastic subspace method, the method of analysis was different. A novelty anal- ysis based on Multivariate Statistical Process Con- trol (MSPC) was used. This paper shows the most explicit use of the language of pattern recognition. The process of feature extraction here produces pat- terns with too high a dimension, so subset selection (natural frequencies only) and Principal Component Analysis (PCA) were used to reduce the dimension. The paper discussed the use of a number of control charts, which are essentially a form of outlier analysis signaling when a feature departs from normal condi- tion. A univariate analysis was carried out using the first principal component from four natural frequen- cies and modeshapes and this proved to give less false positives. The multivariate analysis on four natural frequencies was more sensitive to damage but led to more false positives. Even the lowest pier settlement was detected. An on-line analysis was also conducted and the results were excellent.
En savoir plus

10 En savoir plus

Structural and functional control of surface-patch to hillslope runoff and sediment connectivity in Mediterranean dry reclaimed slope systems

Structural and functional control of surface-patch to hillslope runoff and sediment connectivity in Mediterranean dry reclaimed slope systems

4.2 Functional connectivity: formation of connected runoff and sediment fluxes Rainfall characteristics and antecedent conditions dynami- cally interact with the range of structural elements of the hillslopes to enable or enhance connected flow. Our analy- sis reveals that maximum rainfall intensity and antecedent precipitation are the most relevant storm event factors pro- viding dynamic control of surface-patch to hillslope conti- nuity (or functional connectivity) of runoff (Fig. 5). Both maximum rainfall intensity and antecedent moisture con- ditions are commonly perceived as the main rainfall fac- tors involved in the generation of runoff in Mediterranean landscapes (Calvo-Cases et al., 2003; Castillo et al., 2003; Cammeraat, 2004; Cantón et al., 2011; Mayor et al., 2011; Marchamalo et al., 2016; Martínez-Murillo et al., 2018; Rodríguez-Caballero et al., 2014). Infiltration-excess runoff triggered by high-intensity rainfall typically dominates the hydrological responses of Mediterranean hillslopes under dry conditions. Saturation-excess runoff may also occur in Mediterranean dry hillslopes, particularly on soils previously wetted by antecedent rainfall, inducing saturation of the top layer of the soil profile with moderate-intensity precipitation (Martínez-Mena et al., 1998; Puigdefabregas et al., 1999; Calvo-Cases et al., 2003; Castillo et al., 2003). The poor soil development conditions that characterize our reclaimed study sites may facilitate these two runoff generation mech- anisms (Nicolau and Asensio, 2000; Moreno-de-las-Heras, 2009). Whilst rapid formation of surface crusts in barely cov- ered patches of these reclaimed soils can largely facilitate the formation of infiltration-excess runoff, the massive structure of the soils, particularly in intermediate to deep layers show- ing moderate- to low-vegetation root activity, can also facili- tate the formation of runoff from the temporary saturation of
En savoir plus

19 En savoir plus

Show all 7176 documents...