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Streamwise velocity and wall-shear stress are acquired simultaneously with a hot-wire and an array of azimuthal/spanwise-spaced skin friction sensors in large-scale pipe and boundary layer flow facilities at high Reynolds numbers. These allow for a correlation analysis on a per-scale basis between the velocity and reference skin friction signals to reveal which velocity-based turbulent motions are stochastically coherent with turbulent skin friction. In the logarithmic region, the wall-attached structures in both the pipe and boundary layers show evidence of self-similarity, and the range of scales over which the self-similarity is observed decreases with an increasing azimuthal/spanwise offset between the velocity and the reference skin friction signals. The present empirical observations support the existence of a self-similar range of wall-attached turbulence, which in turn are used to extend the model of Baars et al. (J. Fluid Mech., vol. 823, p. R2) to include the azimuthal/spanwise trends. Furthermore, the region where the self-similarity is observed correspond with the wall height where the mean momentum equation formally admits a self-similar invariant form, and simultaneously where the mean and variance profiles of the streamwise velocity exhibit logarithmic dependence. The experimental observations suggest that the self-similar wall-attached structures follow an aspect ratio of
in the streamwise, spanwise and wall-normal directions, respectively.
Growth in total factor productivity (TFP) in the USA has slowed down significantly since the mid-2000s, reminiscent of the productivity slowdown of the 1970s. This paper investigates the implications of a productivity slowdown on macroeconomic variables using a standard real business cycle (RBC) model, extended with regime-switching in trend productivity growth and Bayesian learning regarding the growth regime. I estimate the Markov-switching parameters using US data and maximum-likelihood methods, and compute the model solution using global projection methods. Simulations reveal that, while adding a regime-switching component to the standard RBC setup increases the volatility in the system, further incorporating incomplete information and learning significantly dampens this effect. The dampening is mainly due to the responses of investment and labor in response to a switch in the trend component of TFP growth, which are weaker in the incomplete information case as agents mistakenly place some probability that the observed decline in TFP growth is due to the transient component and not due to a regime switch. The model offers an objective way to infer slowdowns in trend productivity, and suggests that macroeconomic aggregates in the USA are currently close to their potential levels given observed productivity, while counterfactual simulations indicate that the cost of the productivity slowdown to US welfare has been significant.
Taenia hydatigena, is a common parasite, lived mostly in dogs and wild carnivores in its mature stage, and the larvae, Cysticercus tenuicollis, is found on ruminants and pigs. The aim of the current study was to determine the genetic diversity in 20 isolates of the sheep and goats. After the isolation of total genomic DNA from C. tenuicollis isolates, genetic characterization of the mitochondrial NADH dehydrogenase subunit 1 gene region was amplified using specific JB11–JB12 primers in PCR and the PCR products were sequenced and haplotype and genetic diversity analyses were utilized. As a result, multiple nucleotide changes were determined in the sequence analyses of the isolates leading to detection of 16 and 15 different haplotypes in sheep and goat samples, respectively. These findings are important in terms of showing the diversity of nucleotide variation in C. tenuicollis in Turkey.
This study presents findings from a first-of-its-kind measurement campaign that includes simultaneous measurements of the full velocity and vorticity vectors in both pipe and boundary layer flows under matched spatial resolution and Reynolds number conditions. Comparison of canonical turbulent flows offers insight into the role(s) played by features that are unique to one or the other. Pipe and zero pressure gradient boundary layer flows are often compared with the goal of elucidating the roles of geometry and a free boundary condition on turbulent wall flows. Prior experimental efforts towards this end have focused primarily on the streamwise component of velocity, while direct numerical simulations are at relatively low Reynolds numbers. In contrast, this study presents experimental measurements of all three components of both velocity and vorticity for friction Reynolds numbers
ranging from 5000 to 10 000. Differences in the two transverse Reynolds normal stresses are shown to exist throughout the log layer and wake layer at Reynolds numbers that exceed those of existing numerical data sets. The turbulence enstrophy profiles are also shown to exhibit differences spanning from the outer edge of the log layer to the outer flow boundary. Skewness and kurtosis profiles of the velocity and vorticity components imply the existence of a ‘quiescent core’ in pipe flow, as described by Kwon et al. (J. Fluid Mech., vol. 751, 2014, pp. 228–254) for channel flow at lower
, and characterize the extent of its influence in the pipe. Observed differences between statistical profiles of velocity and vorticity are then discussed in the context of a structural difference between free-stream intermittency in the boundary layer and ‘quiescent core’ intermittency in the pipe that is detectable to wall distances as small as 5 % of the layer thickness.
In cotton–wheat cropping system of Pakistan, wheat (Triticum aestivum L.) is harvested in late April; however, the optimum sowing time of Bt cotton is mid-March. This indicates a time difference of 4–6 weeks between the harvest of wheat and cotton sowing. It is hypothesized that this overlapping period may be managed by transplanting cotton seedlings (30–45 days old) in late April, after the harvest of wheat due to better performance of already established seedlings. To this end, this study was conducted to evaluate the allometric traits and fiber quality of transplanted Bt cotton after harvesting wheat in the cotton–wheat cropping system. The Bt cotton–wheat cropping systems were flat sown wheat (FSW)–conventionally tilled cotton, FSW–zero tilled cotton, ridge sown wheat–ridge transplanted cotton using 30- and 45-days-old seedlings, and bed sown wheat (BSW)–bed transplanted cotton (BTC) also using 30- and 45-days-old seedlings. The study was conducted at Vehari and Multan in Punjab, Pakistan. Bt cotton in BSW–BTC with 45-days-old seedlings showed better performance for allometric (leaf area index; (LAI), net assimilation rate; (NAR), and crop growth rate; (CGR)), seed cotton yield, and fiber traits (fiber uniformity, fiber length, fiber strength, and fiber fineness) in comparison to other treatments. Most of the fiber quality traits were positively correlated with allometric traits and biological yield (dry matter yield at maturity) at both locations, except correlations of CGR and LAI with fiber fineness and fiber length and NAR with fiber length. As plant growth and fiber quality of transplanted cotton was significantly higher than conventionally grown cotton, our data indicate transplanting is an interesting management practice for improving productivity in wheat–cotton cropping systems.
This paper aims to give an overview of education of librarians, professional associations, publications and the types of libraries in Turkey. In addition, the activities of the Turkish Platform of Law Librarians and law librarianship in Turkey are presented.
This paper presents the results of the geophysical prospection conducted at the site of Meninx (Jerba) in 2015. This was the first step in a Tunisian-German project (a cooperation between the Institut National du Patrimoine, Tunis, and the Institut für Klassische Archäologie der Ludwig-Maximilans-Universität München), the aim of which is to shed light on the urban history of the most important city on the island of Jerba in antiquity.
Meninx, situated on the SE shore of the island (fig. 1), was the largest city on Jerba during the Roman Empire and eponymous for the island's name in antiquity. The outstanding importance of this seaport derived from the fact that it was one of the main production centers of purple dye in the Mediterranean. With the earliest secure evidence dating to at least the Hellenistic period, Meninx saw a magnificent expansion in the 2nd and 3rd c. A.D. It was inhabited until the 7th c. when the city was finally abandoned.
Smartphone Apps are one of the tools available to support patients who wish to quit smoking. Content analysis studies have indicated multiple deficiencies within these Apps including minimal use of evidence-based research and Nicotine Dependence Treatment Provider (NDTP) in App development. The aim of this study was to determine quality and features of smoking cessation Apps available on Android® and iOS® platforms.
The first fifty free smoking cessation Apps available for download using the search term smoking cessation on Google Play Store and Apple App Store were chosen. Each of these Apps was analyzed and categorized based on ratings, target audience age, language, and a variety of tracking functionalities noted on the Apps. Indications and suggestions regarding either the use of NDTP or evidence-based behavior change protocols were noted.
There were no significant differences in the features of smoking cessation Apps on Android and iOS. Only 15 percent of all Apps analyzed on both platforms indicated some involvement of NDTP and there was no difference between the two platforms. More than 50 percent of Apps studied were downloaded over half a million times and the average user rating was 3.89/5.00 for Android and 3.72/5.00 for iOS with no significant difference.
Most smoking cessation Apps in both platforms offer basic tracking functionalities with limited motivational tips. Only a handful of Apps have moved beyond this role and while their development is applaudable much innovation remains.
In this paper, a parametric analysis of the inverse dynamics of an upright partially unloaded walking is performed. This motion is produced through a gait-training machine emulating the over-ground walking using a body weight support mechanism and a cable-driven robot. The input motion is the kinematics of a normal gait, and the ultimate output result is the required tensions to be generated by the cable robot in order to drive the lower limb. The dynamic analysis is carried out based on the Newton–Euler approach. A Matlab Simscape model is also built to validate the analytical results. The obtained dynamic model is used to investigate the effect of the variation of the gait simulation parameters on the actuation wrench and the cable tensions. The obtained results could be used to determine the optimal design of the gait trainer actuators and they are useful in estimating optimal gait training parameters.
Fully resolved measurements of turbulent boundary layers are reported for the Reynolds number range
. Despite several decades of research in wall-bounded turbulence there is still controversy over the behaviour of streamwise turbulence intensities near the wall, especially at high Reynolds numbers. Much of it stems from the uncertainty in measurement due to finite spatial resolution. Conventional hot-wire anemometry is limited for high Reynolds number measurements due to limited spatial resolution issues that cause attenuation in the streamwise turbulence intensity profile near the wall. To address this issue we use the nano-scale thermal anemometry probe (NSTAP), developed at Princeton University to conduct velocity measurements in the high Reynolds number boundary layer facility at the University of Melbourne. The NSTAP has a sensing length almost one order of magnitude smaller than conventional hot-wires. This enables us to acquire fully resolved velocity measurements of turbulent boundary layers up to
. Results show that in the near-wall region, the viscous-scaled streamwise turbulence intensity grows with
in the Reynolds number range of the experiments. A second outer peak in the streamwise turbulence intensity is also shown to emerge at the highest Reynolds numbers. Moreover, the energy spectra in the near-wall region show excellent inner scaling over the small to moderate wavelength range, followed by a large-scale influence that increases with Reynolds number. Outer scaling in the outer region is found to collapse the energy spectra over high wavelengths across various Reynolds numbers.
The importance of parasites as a selective force in host evolution is a topic of current interest. However, short-term ecological studies of host–parasite systems, on which such studies are usually based, provide only snap-shots of what may be dynamic systems. We report here on four surveys, carried out over a period of 12 years, of helminths of spiny mice (Acomys dimidiatus), the numerically dominant rodents inhabiting dry montane wadis in the Sinai Peninsula. With host age (age-dependent effects on prevalence and abundance were prominent) and sex (female bias in abundance in helminth diversity and in several taxa including Cestoda) taken into consideration, we focus on the relative importance of temporal and spatial effects on helminth infracommunities. We show that site of capture is the major determinant of prevalence and abundance of species (and higher taxa) contributing to helminth community structure, the only exceptions being Streptopharaus spp. and Dentostomella kuntzi. We provide evidence that most (notably the Spiruroidea, Protospirura muricola, Mastophorus muris and Gongylonema aegypti, but with exceptions among the Oxyuroidae, e.g. Syphacia minuta), show elements of temporal-site stability, with a rank order of measures among sites remaining similar over successive surveys. Hence, there are some elements of predictability in these systems.
This paper , which was published online on 1 June 2011, has been retracted by agreement between the authors, the journal’s Editor-in-Chief Derek Holt, the London Mathematical Society and Cambridge University Press. The retraction was agreed to prevent other authors from using incorrect mathematical results. (In this paper, we compute and verify the positivity of the Li coefficients for the Dirichlet
-functions using an arithmetic formula established in Omar and Mazhouda, J. Number Theory 125 (2007) no. 1, 50–58; J. Number Theory 130 (2010) no. 4, 1109–1114. Furthermore, we formulate a criterion for the partial Riemann hypothesis and we provide some numerical evidence for it using new formulas for the Li coefficients.)
Cystic echinococcosis (CE) is a severe parasitic disease caused by the species complex Echinococcus granulosus sensu lato. Human infections are most commonly associated with E. granulosus sensu stricto (s.s.), comprising genotypes G1 and G3. The objective of the current study was to provide first insight into the genetic diversity and phylogeography of genotype G3. Despite the epidemiological importance of the genotype, it has remained poorly explored due to the ambiguity in the definition of the genotype. However, it was recently demonstrated that long sequences of mitochondrial DNA (mtDNA) provide a reliable method to discriminate G1 and G3 from each other. Therefore, we sequenced near-complete mtDNA of 39 G3 samples, covering most of the known distribution range and host spectra of the genotype. The phylogenetic network revealed high genetic variation within E. granulosus s.s. G3 and while G3 is significantly less prevalent worldwide than G1, the genetic diversity of both of the genotypes is equally high. We also present the results of the Bayesian phylogeographic analysis, which yielded several well-supported diffusion routes of genotype G3 originating from Turkey and Iran, suggesting the Middle East as the origin of the genotype.