The wall effect in cavity flow

A non-linear theory for the calculation of the flow field of an oblique flat plate under blockage condition is given using the techniques of integral equations. Numerical results are obtained with the aid of a high speed digital computer for the plate situated mid-channel at values of the angle of attack from 50 to 90° and the channel width-chord ratio from 3 to 20. Also obtained are results for the plate situated at two different off-center positions for a channel width-chord ratio 5 and angles of attack less than 30°

Construction of nested space-filling designs

New types of designs called nested space-filling designs have been proposed for conducting multiple computer experiments with different levels of accuracy. In this article, we develop several approaches to constructing such designs. The development of these methods also leads to the introduction of several new discrete mathematics concepts, including nested orthogonal arrays and nested difference matrices.Comment: Published in at http://dx.doi.org/10.1214/09-AOS690 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

A Computer Method for Calculation of the Complete and Incomplete Elliptic Integrals of the Third Kind

Numerical approximations and a Fortran IV program are given for the calculation by an IBM 7090 computer of the complete and incomplete elliptic integrals of the third kind. In its present form results are limited to six decimal places, but the method is valid for all values of amplitude φ, modulus k and real values of the parameter a^2. For the purpose of completeness, adaptations of other programs for complete and incomplete elliptic integrals of the first and second kind are also presented

Malaria among antenatal clients attending primary health care facilities in Kano state, Nigeria

Background: Malaria in pregnancy remains a major public health problem especially in sub-Saharan Africa. However, the prevalence of clinical and asymptomatic infection among antenatal client (ANC) attendees is largely unknown, especially at primary health care (PHC) level in northern Nigeria. This study assessed the prevalence of fever, malarial parasitemia and anemia among pregnant women attending PHC facilities in Kano, northern Nigeria.Methods: A cross-sectional descriptive study was conducted among 360 ANCs attending PHC facilities in two Local Government Areas (LGAs) in Kano state. Data were collected using a pre-tested semi-structured interviewer administered questionnaire. Blood samples were also obtained for thin blood smear for malaria parasite using Giemsa staining technique. Hemoglobin was estimated from the Packed Cell Volume (PCV) determined using hematocrit.Results: Age of the subjects ranged from 15 to 42 years with a mean } SD of 24.0 } 6.0. Up to 39.2% (n = 141) (95% Confi dence Interval = 34.1.44.4%) of the subjects were found to have malarial parasitemia. Exactly 36.2% (n = 51) of those with parasitemia had fever (temperature . 37.5oC) while 63.8% (n = 90) of them were asymptomatic. Anemia,(hemoglobin of .11 g/dl) was found in 48.1% (n = 173) of the  respondents. A higher proportion of primigravid and secondigravid clients (61% vs. 39%) and younger pregnant women (54.6% vs. 45.4%) had malarial parasitemia compared to multigravid and older women, respectively. Similarly, a signifi cantly higher proportion (67.6%) ofanemic ANC clients had malarial parasitemia. (ƒÔ2 = 113.25, df = 1, P < 0.05).Conclusion: Malarial infection is common among the ANC clients attending PHC facilities in Kano state and the infection is commonly associated with anemia. Intermittent Preventive Treatment (IPT) should be provided especially among primigravid, secondigravid and younger mothers at PHC centres

Active interaction control applied to a lower limb rehabilitation robot by using EMG recognition and impedance model

Purpose – The purpose of this paper is to propose a seamless active interaction control method integrating electromyography (EMG)-triggered assistance and the adaptive impedance control scheme for parallel robot-assisted lower limb rehabilitation and training. Design/methodology/approach – An active interaction control strategy based on EMG motion recognition and adaptive impedance model is implemented on a six-degrees of freedom parallel robot for lower limb rehabilitation. The autoregressive coefficients of EMG signals integrating with a support vector machine classifier are utilized to predict the movement intention and trigger the robot assistance. An adaptive impedance controller is adopted to influence the robot velocity during the exercise, and in the meantime, the user’s muscle activity level is evaluated online and the robot impedance is adapted in accordance with the recovery conditions. Findings – Experiments on healthy subjects demonstrated that the proposed method was able to drive the robot according to the user’s intention, and the robot impedance can be updated with the muscle conditions. Within the movement sessions, there was a distinct increase in the muscle activity levels for all subjects with the active mode in comparison to the EMG-triggered mode. Originality/value – Both users’ movement intention and voluntary participation are considered, not only triggering the robot when people attempt to move but also changing the robot movement in accordance with user’s efforts. The impedance model here responds directly to velocity changes, and thus allows the exercise along a physiological trajectory. Moreover, the muscle activity level depends on both the normalized EMG signals and the weight coefficients of involved muscles

Decoherence-Based Quantum Zeno Effect in a Cavity-QED System

We present a decoherence-based interpretation for the quantum Zeno effect (QZE) where measurements are dynamically treated as dispersive couplings of the measured system to the apparatus, rather than the von Neumann's projections. It is found that the explicit dependence of the survival probability on the decoherence time quantitatively distinguishes this dynamic QZE from the usual one based on projection measurements. By revisiting the cavity-QED experiment of the QZE [J. Bernu, et al., Phys. Rev. Lett, 101, 180402 (2008)], we suggest an alternative scheme to verify our theoretical consideration that frequent measurements slow down the increase of photon number inside a microcavity due to the nondemolition couplings with the atoms in large detuning.Comment: 4 pages, 3 figure

Mise en évidence des valeurs nutritionnelles de dix (10) variétés de patate douce [Ipomea batatas (L.) Lam.] du Burkina Faso

Cette étude a été réalisée dans le but d’évaluer les paramètres biochimiques des tubercules de dix (10) variétés de patate douce Ipomea batatas (L.) Lam. Des analyses réalisées au laboratoire ont permis de déterminer les teneurs en sucres, en protéines, en vitamine A, en sels minéraux et en cendres. Des résultats, il ressort que la variété Jewel qui enregistre 25,02% de sucres totaux, 9,62% de sucres réducteurs et 854,25 μg/g de β carotène est plus riche en sucres. La variété BF 13 se distingue des autres par une teneur plus élevée en protéine soit environ 2,54%. Par contre, la variété BF 140 a montré une teneur en calcium (266,75 mg /100 g), en fer (44,74 mg/100 g), en zinc (2,31 mg/100 g) et en cendres (6,57%) plus importante comparativement aux autres variétés. La variété BF 40 a une teneur plus élevée en phosphore (286,75 mg/100 g). Cependant, la variété BF 142 a la plus forte teneur en potassium soit 2341,50 mg/100 g.Mots clés : Ipomea batatas, variétés, matière minérale, matière organique