Intermittency in Two-Dimensional Turbulence with Drag

We consider the enstrophy cascade in forced two-dimensional turbulence with a linear drag force. In the presence of linear drag, the energy wavenumber spectrum drops with a power law faster than in the case without drag, and the vorticity field becomes intermittent, as shown by the anomalous scaling of the vorticity structure functions. Using a previous theory, we compare numerical simulation results with predictions for the power law exponent of the energy wavenumber spectrum and the scaling exponents of the vorticity structure functions $\zeta_{2q}$ obtained in terms of the distribution of finite time Lyapunov exponents. We also study, both by numerical experiment and theoretical analysis, the multifractal structure of the viscous enstrophy dissipation in terms of its R\'{e}nyi dimension spectrum $D_q$ and singularity spectrum $f(\alpha)$. We derive a relation between $D_q$ and $\zeta_{2q}$, and discuss its relevance to a version of the refined similarity hypothesis. In addition, we obtain and compare theoretically and numerically derived results for the dependence on separation $r$ of the probability distribution of \delta_{\V{r}}\omega, the difference between the vorticity at two points separated by a distance $r$. Our numerical simulations are done on a $4096 \times 4096$ grid.Comment: 18 pages, 17 figure

Dynamic and Static Gesture Recognition System Using Moments

Gesture recognition is the novel idea to enhance the signs recognition of those who have speech and hearing disability .Our project discusses an improved method for gesture recognition .The algorithm extracts the gestures from the video given to it and it detects the hand using HSV skin color segmentation in the intent to eliminate the other parts of the body and detect only hands .It distinguishes between static and dynamic gestures and extracts the appropriate feature vector .We used SPHINX parser to form word from set of letters. We strive to enhance the reliability and efficiency by using faster static gesture recognition algorithm

Process involved in designing of an intelligent additional track mechanism tracked vehicle for swamp peat terrain

Different types of off road vehicles are widely used in agriculture, oil industry, mining and military operations but none of them can effectively operate over the swamp peat terrain because of its low bearing capacity of 7kN/m 2. Segmented rubber tracked vehicle and intelligent air-cushion system tracked vehicle were developed in Malaysia for swamp peat terrain.16kN/m2 of ground pressure was exerted by using the segmented rubber tracked vehicle during field operation therefore could not be operated efficiently. The air-cushion tracked vehicle increased the floatation capacity but at the same time increased the frictional effects therefore the tracks of the vehicle easily slipped out from the traction wheels during operation. Addressing these issues an intelligent additional track mechanism for tracked vehicle has been designed to improve the mobility over swamp peat terrain where the additional track would be increased the ground surface area and reduced the vehicle ground pressure. This paper presents the process involved in designing the intelligent additional track mechanism tracked vehicle for transportation of agricultural and industrial goods on the swamp peat terrain with bearing capacity of 7kN/m2. The mechanical design comprises of track vehicle frame with track mechanism. Additional track mechanism with Fuzzy expert system. The design parameters are optimized using developed mathematical model based on the dynamics and kinematics behavior of the vehicle. In order to increase the vehicle contact surface area and reduce the surface contact pressure the additional track mechanism is designed in such way that it can be folded and unfolded from its position by using the ball-screw scissor lift mechanism. While, Fuzzy expert system is used to control the movement of the lift mechanism based on 70mm critical sinkage of vehicle detected from a set of sensors. The completed to vehicle system would be used for off-road applications as required

Lower bounds on the dilation of plane spanners

(I) We exhibit a set of 23 points in the plane that has dilation at least $1.4308$, improving the previously best lower bound of $1.4161$ for the worst-case dilation of plane spanners. (II) For every integer $n\geq13$, there exists an $n$-element point set $S$ such that the degree 3 dilation of $S$ denoted by $\delta_0(S,3) \text{ equals } 1+\sqrt{3}=2.7321\ldots$ in the domain of plane geometric spanners. In the same domain, we show that for every integer $n\geq6$, there exists a an $n$-element point set $S$ such that the degree 4 dilation of $S$ denoted by $\delta_0(S,4) \text{ equals } 1 + \sqrt{(5-\sqrt{5})/2}=2.1755\ldots$ The previous best lower bound of $1.4161$ holds for any degree. (III) For every integer $n\geq6$, there exists an $n$-element point set $S$ such that the stretch factor of the greedy triangulation of $S$ is at least $2.0268$.Comment: Revised definitions in the introduction; 23 pages, 15 figures; 2 table

The sphere-in-contact model of carbon materials

A sphere-in-contact model is presented that is used to build physical models of carbon materials such as graphite, graphene, carbon nanotubes and fullerene. Unlike other molecular models, these models have correct scale and proportions because the carbon atoms are represented by their atomic radius, in contrast to the more commonly used space-fill models, where carbon atoms are represented by their van der Waals radii. Based on a survey taken among 65 undergraduate chemistry students and 28 PhD/postdoctoral students with a background in molecular modeling, we found misconceptions arising from incorrect visualization of the size and location of the electron density located in carbon materials. Based on analysis of the survey and on a conceptual basis we show that the sphere-in-contact model provides an improved molecular representation of the electron density of carbon materials compared to other molecular models commonly used in science textbooks (i.e., wire-frame, ball-and-stick, space-fill). We therefore suggest that its use in chemistry textbooks along with the ball-and-stick model would significantly enhance the visualization of molecular structures according to their electron density

Use of antibiotic and prevalence of antibiotic-associated diarrhoea in-patients with spinal cord injuries: a UK national spinal injury centre experience

BACKGROUND: This was a retrospective audit, with the aims being to (1) record the use of antibiotics; (2) establish the prevalence of antibiotic-associated diarrhoea (AAD) and Clostridium difficile-associated diarrhoea (CDAD); and (3) assess if there was any seasonal variation in antibiotic use and incidence of AAD. METHODS: The study was performed at a single spinal cord injury (SCI) centre in the UK. Data were collected using a standardised questionnaire during October 2014 to June 2015. We define AAD as two or more watery stools of type 5, 6 or 7 (Bristol stool scale) over 24 h. RESULTS: Three-hundred-and-nineteen adults (mean age: 55.9 years, 29.2% female) with SCI (58.2% tetraplegia; 43.7% complete SCI) were included. Of 70 (21.9%) patients on antibiotics, the top three indications for antibiotics were urinary-tract infections, infected pressure ulcers and other skin infections. Seventeen of 78 (21.8%) developed AAD and three of 319 (0.94%) developed CDAD. AAD was more common in the summer season than in spring, autumn and winter (47.1%, 10.0%, 10.0%, 23.8%, P=0.025). AAD was associated with older adults greater than 65 years (70.6% vs 23.8%, P=0.007). Polypharmacy and the summer season were identified as independent predictors for AAD. CONCLUSION: This survey found that AAD is common in SCI patients and may be a risk factor for a poorer outcome and increased hospital costs. A multicentre study is underway to establish the incidence and risk factors for AAD

Dairy consumption and cardiometabolic diseases: systematic review and updated meta-analyses of prospective cohort studies

Purpose of Review Dairy products contain both beneficial and harmful nutrients in relation to cardiometabolic diseases. Here, we provide the latest scientific evidence regarding the relationship between dairy products and cardiometabolic diseases by reviewing the literature and updating meta-analyses of observational studies. Recent Findings We updated our previous meta-analyses of cohort studies on type 2 diabetes, coronary heart disease (CHD), and stroke with nine studies and confirmed previous results. Total dairy and low-fat dairy (per 200 g/d) were inversely associated with a 3–4% lower risk of diabetes. Yogurt was non-linearly inversely associatedwith diabetes (RR = 0.86, 95%CI: 0.83–0.90 at 80 g/ d). Total dairy and milk were not associated with CHD (RR~1.0). An increment of 200 g of daily milk intake was associated with an 8% lower risk of stroke. Summary The latest scientific evidence confirmed neutral or beneficial associations between dairy products and risk of cardiometabolic diseases

Some properties of resin treated viscose rayon

A study has been made of some physical and chemical properties of viscose rayon, and the modifications in these properties resulting from the addition of a resin. Methods of stripping a resin from a fabric have been studied and it has been shown that chemical degradation may result, hut the use of 0.1N hydrochloric acid at 6

Three-dimensional modulation instability of dust-ion-acoustic waves and rogue waves in warm nonthermal magnetized plasmas

A theoretical investigation has been made to study the modulation stability/instability of three-dimensional dust-ion-acoustic wave packets in the warm magnetized complex plasma system in the presence of nonthermal distributed electrons and positrons species. The set of equations describing our plasma system has been reduced to a (3+1)-dimensional nonlinear Schr\"odinger equation by using the reductive perturbation method that is valid for finite but small amplitude limits. It is observed that both nonlinear and dispersive coefficients of (3+1)-dimensional nonlinear Schr\"odinger equation are significantly modified by the external magnetic field and transverse velocity perturbation. The regions of stable and unstable for the modulated dust-ion-acoustic waves have been examined numerically. Moreover, the dependence of modulation instability and rogue waves on the relevant plasma parameters is discussed. The implications of our theoretical results in space and laboratories magnetized dusty plasma medium is briefly discussed.Comment: 7 pages, 9 figures, original articl