173 research outputs found
The Violation of Cooperative Principle a Case of Humorous Verbal Cartoon in Kompas
This research is aimed at describing the types of maxim violated in humorous verbal cartoon in Kompas, to find out the type of the maxims that is dominantly violated in it and to find out the causes. The method of research is descriptive qualitative research. The data is analyzed by interpreting the conversations and analyzing them based on the types of the maxim violated. From the data, it was found that the violation of the maxim of quality is 12 (20.33%), the violation of the maxim of quantity is 25 (42.37%), the violation of manner is 15 (25.42%), and the violation of the maxim of relevance is 7 (11.86%). The frequency and the percentage shows that maxim of quantity is the dominant type of maxim which is violated
3-D Perturbations in Conformal Turbulence
The effects of three-dimensional perturbations in two-dimensional turbulence
are investigated, through a conformal field theory approach. We compute scaling
exponents for the energy spectra of enstrophy and energy cascades, in a strong
coupling limit, and compare them to the values found in recent experiments. The
extension of unperturbed conformal turbulence to the present situation is
performed by means of a simple physical picture in which the existence of small
scale random forces is closely related to deviations of the exact
two-dimensional fluid motion.Comment: Discussion of intermittency improved. Figure include
Structure of a Bathtub Vortex : Importance of the Bottom Boundary Layer
A bathtub vortex in a cylindrical tank rotating at a constant angular velocity [omega] is studied by meansof a laboratory experiment, a numerical experiment and a boundary layer theory. The laboratory and numerical experiments show that two regimes of vortices in the steady-state can occur depending on [omega] and the volume flux Q through the drain hole: when Q is large and [omega] is small, a potential vortex is formed in which angular momentum outside the vortex core is constant in the non-rotating frame. However, when Q is small or [omega] is large, a vortex is generated in which the angular momentum decreases with decreasing radius. Boundary layertheory shows that the vortex regimes strongly depend on the theoretical radial volume flux through the bottomboundary layer under a potential vortex : when the ratio of Q to the theoretical boundary-layer radial volume flux Qb (scaled by 2π R2([omega] ν)12 ) at the outer rim of the vortex core is larger than a critical value (of order 1), the radial flow in the interior exists at all radiiand Regime I is realized, where R is the inner radius of the tank and ν the kinematicviscosity.When the ratio is less than the critical value, the radial flow in the interior nearlyvanishes inside a critical radius and almost all of the radial volume flux occurs only in the boundary layer,resulting in Regime II in which the angular momentum is not constant with radius. This criterion is found to explain the results of the laboratory and numerical experiments very well
Active Flow Control on Vertical Tail Models
Active flow control (AFC) subscale experiments were conducted at the Lucas Wind Tunnel of the California Institute of Technology. Tests were performed on a generic vertical tail model at low speeds. Fluidic oscillators were used at the trailing edge of the main element (vertical stabilizer) to redirect the flow over the rudder and delay or prevent flow separation. Side force increases in excess of 50% were achieved with a 2% momentum coefficient (C_μ) input. The results indicated that a collective C_μ of about 1% could increase the side force by 30–50%. This result is achieved by reducing the spanwise flow on the swept back wings that contributes to early flow separation near their tips. These experiments provided the technical backdrop to test the full-scale Boeing 757 vertical tail model equipped with a fluidic oscillator system at the National Full-scale Aerodynamics Complex 40-by 80-foot Wind Tunnel, NASA Ames Research Center. The C_μ is shown to be an important parameter for scaling a fluidic oscillator AFC system from subscale to full-scale wind tunnel tests. The results of these tests provided the required rationale to use a fluidic oscillator AFC configuration for a follow-on flight test on the Boeing 757 ecoDemonstrator
Active Flow Control on Vertical Tail Models
Active flow control (AFC) subscale experiments were conducted at the Lucas Wind Tunnel of the California Institute of Technology. Tests were performed on a generic vertical tail model at low speeds. Fluidic oscillators were used at the trailing edge of the main element (vertical stabilizer) to redirect the flow over the rudder and delay or prevent flow separation. Side force increases in excess of 50% were achieved with a 2% momentum coefficient (C(sub )) input. The results indicated that a collective C(sub ) of about 1% could increase the side force by 3050%. This result is achieved by reducing the spanwise flow on the swept back wings that contributes to early flow separation near their tips. These experiments provided the technical backdrop to test the full-scale Boeing 757 vertical tail model equipped with a fluidic oscillator system at the National Full-scale Aerodynamics Complex 40-by 80-foot Wind Tunnel, NASA Ames Research Center. The C(sub ) is shown to be an important parameter for scaling a fluidic oscillator AFC system from subscale to full-scale wind tunnel tests. The results of these tests provided the required rationale to use a fluidic oscillator AFC configuration for a follow-on flight test on the Boeing 757 ecoDemonstrator
The crystal structure of human Rogdi provides insight into the causes of Kohlschutter-Tonz Syndrome
Kohlschutter-Tönz syndrome (KTS) is a rare autosomal-recessive disorder of childhood onset characterized by global developmental delay, spasticity, epilepsy, and amelogenesis imperfecta. Rogdi, an essential protein, is highly conserved across metazoans, and mutations in Rogdi are linked to KTS. However, how certain mutations in Rogdi abolish its physiological functions and cause KTS is not known. In this study, we determined the crystal structure of human Rogdi protein at atomic resolution. Rogdi forms a novel elongated curved structure comprising the ?? domain, a leucine-zipper-like four-helix bundle, and a characteristic ??-sheet domain. Within the ?? domain, the N-terminal H1 helix (residues 19-45) pairs with the C-terminal H6 helix (residues 252-287) in an antiparallel manner, indicating that the integrity of the four-helix bundle requires both N- and C-terminal residues. The crystal structure, in conjunction with biochemical data, indicates that the ?? domain might undergo a conformational change and provide a structural platform for protein-protein interactions. Disruption of the four-helix bundle by mutation results in significant destabilization of the structure. This study provides structural insights into how certain mutations in Rogdi affect its structure and cause KTS, which has important implications for the development of pharmaceutical agents against this debilitating neurological disease
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