2,560 research outputs found

    Case studies to enhance online student evaluation: Bond University – Surveying students online to improve learning and teaching

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    One of the most sensible ways of improving learning and teaching is to ask the students for feedback. At the end of each teaching period (i.e. semester or term) all universities and many schools survey their students. Usually these surveys are managed online. Questions ask for student perceptions about teaching, assessment and workload. The survey administrators report four common problems

    Constraints on the perturbed mutual motion in Didymos due to impact-induced deformation of its primary after the DART impact

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    Binary near-Earth asteroid (65803) Didymos is the target of the proposed NASA Double Asteroid Redirection Test (DART), part of the Asteroid Impact & Deflection Assessment (AIDA) mission concept. In this mission, the DART spacecraft is planned to impact the secondary body of Didymos, perturbing mutual dynamics of the system. The primary body is currently rotating at a spin period close to the spin barrier of asteroids, and materials ejected from the secondary due to the DART impact are likely to reach the primary. These conditions may cause the primary to reshape, due to landslides, or internal deformation, changing the permanent gravity field. Here, we propose that if shape deformation of the primary occurs, the mutual orbit of the system would be perturbed due to a change in the gravity field. We use a numerical simulation technique based on the full two-body problem to investigate the shape effect on the mutual dynamics in Didymos after the DART impact. The results show that under constant volume, shape deformation induces strong perturbation in the mutual motion. We find that the deformation process always causes the orbital period of the system to become shorter. If surface layers with a thickness greater than ~0.4 m on the poles of the primary move down to the equatorial region due to the DART impact, a change in the orbital period of the system and in the spin period of the primary will be detected by ground-based measurement.Comment: 8 pages, 7 figures, 2 tables, accepted for publication in MNRA

    Small Quadrupole Deformation for the Dipole Bands in 112In

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    High spin states in 112^{112}In were investigated using 100^{100}Mo(16^{16}O, p3n) reaction at 80 MeV. The excited level have been observed up to 5.6 MeV excitation energy and spin \sim 20\hbar with the level scheme showing three dipole bands. The polarization and lifetime measurements were carried out for the dipole bands. Tilted axis cranking model calculations were performed for different quasi-particle configurations of this doubly odd nucleus. Comparison of the calculations of the model with the B(M1) transition strengths of the positive and negative parity bands firmly established their configurations.Comment: 10 pages, 11 figures, 2 table

    Bianchi type II models in the presence of perfect fluid and anisotropic dark energy

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    Spatially homogeneous but totally anisotropic and non-flat Bianchi type II cosmological model has been studied in general relativity in the presence of two minimally interacting fluids; a perfect fluid as the matter fluid and a hypothetical anisotropic fluid as the dark energy fluid. The Einstein's field equations have been solved by applying two kinematical ans\"{a}tze: we have assumed the variation law for the mean Hubble parameter that yields a constant value of deceleration parameter, and one of the components of the shear tensor has been considered proportional to the mean Hubble parameter. We have particularly dwelled on the accelerating models with non-divergent expansion anisotropy as the Universe evolves. Yielding anisotropic pressure, the fluid we consider in the context of dark energy, can produce results that can be produced in the presence of isotropic fluid in accordance with the \Lambda CDM cosmology. However, the derived model gives additional opportunities by being able to allow kinematics that cannot be produced in the presence of fluids that yield only isotropic pressure. We have obtained well behaving cases where the anisotropy of the expansion and the anisotropy of the fluid converge to finite values (include zero) in the late Universe. We have also showed that although the metric we consider is totally anisotropic, the anisotropy of the dark energy is constrained to be axially symmetric, as long as the overall energy momentum tensor possesses zero shear stress.Comment: 15 pages; 5 figures; matches the version published in The European Physical Journal Plu

    Cervical traction: a simple step ahead in the prevention of postpartum hemorrhage

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    Background: Postpartum hemorrhage is the most common preventable cause of maternal mortality in developing countries. The present study aimed to examine the impact of cervical traction technique in reducing the amount of postpartum blood loss and rate of PPH.Methods: This was a case-control, pilot study conducted in a tertiary hospital between June 2017 to June 2018. A total of 200 singletons, low-risk pregnant females, undergoing normal vaginal delivery, were enrolled in this study. Subjects showing a high risk for PPH were excluded. Patients were randomized as case group (n=100) and control group (n=100). The case group received sustained traction for 90 seconds to anterior and posterior lip of the cervix with active management of the third stage of labor, whereas the control group received routine active management of the third stage of labor. All subjects were followed up for 6 hours post-delivery. The amount of blood loss, hematocrit and hemoglobin post-delivery were compared between both groups.Results: The mean blood loss (ml), decrease in hemoglobin (g/L) and decrease in hematocrit post-delivery in cases were significantly low compared to controls (207±37.6 versus 340±49, P<0.01), (0.78±0.2 versus 1.4±0.3, P=0.03) and (1.7±0.2 versus 3.5±0.2, P<0.01). PPH occurred in 7 of 200 (3.5%) patients. The difference in the number of PPH was not significant (5/100; 5% versus 2/100; 2% P=0.2). There were no complications reported due to cervical traction.Conclusions: Cervical traction is a simple and safe maneuver to reduce the amount of postpartum blood loss. Larger RCT is recommended to investigate the reduction in PPH rate

    VALIDATED SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF CHLORAMPHENICOL IN PURE AND IN ITS DOSAGE FORM

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    A simple, précis, rapid sensitive and accurate spectrophotometric methods have been developed for the estimation of Chloramphenicol UV in pure form and its pharmaceutical formulations based on oxidative coupling reaction UV with MBTH reagent at P H-4 which is extractable at 620 nm. Beer's law is obeyed in the concentration range 1-6 ml (10-60 µgml-1). The developed method was applied directly and easily for the analysis of the pharmaceutical formulations. RSD was found to be 0.0194 % and recovery 99.73%. The method was completely validated and proven to be rugged. The interferences of the ingredients and excipients were not observed. The repeatability and the performance of the proved method were established by point and internal hypothesis and through recovery studies.Keywords: Spectrophotometry, Chloramphenicol, MBTH, Oxidative coupling

    VALIDATED SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF CHLORAMPHENICOL IN PURE AND IN ITS DOSAGE FORM

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    Objective: A simple, economic, selective, precise, and accurate UV-Visible spectrophotometric method for the analysis of Chloramphenicol in bulk drug and pharmaceutical formulations was developed and validated in the present study. Methods: Based on oxidative coupling reaction with MBTH reagent at PH-4.5 which is extractable at 620 nm. The Beer's law is obeyed in the concentration range 1-6 ml (10-60 µg ml-1). Results: The RSD was found to be 0.0194% and recovery is 99.73%. The method was completely validated and proven to be rugged. The interferences of the ingredients and recipients were not observed. The repeatability and the performance of the proved method were established by point and internal hypothesis and through recovery studies. Conclusion: The method was found to be accurate and precise, as indicated by recovery studies close to 100 and % RSD is not more than 2. The summery of validation parameters of proposed UV-Visible method is given
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