Proposal for an Integrated Raman-free Correlated Photon Source

We propose a dual-pump third-order nonlinear scheme for producing pairs of correlated photons that is less susceptible to Raman noise than typical spontaneous four wave mixing methods (SFWM). Beginning with the full multimode Hamiltonian we derive a general expression for the joint spectral amplitude, from which the probability of producing a pair of photons can be calculated. As an example, we demonstrate that a probability of 0.028 pairs per pulse can be achieved in an appropriately designed fused silica microfiber. As compared with single pump SFWM in standard fiber, we calculate that our process shows significant suppression of the spontaneous Raman scattering and an improvement in the signal to noise ratio.Comment: 7 pages, 3 figures (two containing 2 subfigures

The provision and utilisation of casemix and demographic data by nursing managers in seven hospitals.

The role of the nursing manager has evolved from clinician and bed manager to one with greater accountability for evidence based practice, benchmarking and more recently, budget liability. Casemix data are widely believed to be a means of providing essential information for effective decision making and financial management but have not been widely utilised by nursing managers (Diers & Bozzo, 1999). This paper will report the results of a survey of nursing managers in seven hospitals within a metropolitan area health service. The hospitals include tertiary referral hospitals, specialist public hospitals and an affiliated public hospital for aged care and rehabilitation services. The survey sought to establish what casemix and related data were provided to nurse managers, who provided these data and how supplied data were utilised by the nurse managers. Results demonstrated that the majority of nursing managers surveyed received minimal (if any) casemix and/or demographic data on a routine basis. Some were provided with data in response to specific requests. The information that was provided varied both within and across hospitals, and no consistent methods of data distribution were available. Few nursing managers believed that the information provided aided their decision-making processes partly due to the minimalist nature of provided data while some nursing managers demonstrated a lack of understanding of the potential benefit of casemix data as a resource to support management decision making

Food and feeding habits of grey Mullets (Pisces: Mugilidae) in two estuaries in Ghana

Food and feeding habits of grey mullets (Mugilidae) in the River Volta and River Pra estuaries in Ghana were studied between February 1997 and July 1998 as part of efforts to encourage their culture. Stomach contents of fish samples, obtained with a cast net and a drag net, were analysed using the ‘points’ and frequency of occurrence method. Diatoms, detrital material and sand particles were the major items in the stomachs of all the species from the two estuaries. Their diet did not show any substantial seasonality, neither did it change with size. The various species ingested sand particles of selected range with Liza dumerilii ingesting the widest range in both estuaries, 41.2-1195.8 ìm in the Volta estuary, and 33.0-1649.0 ìm in the Pra estuary. Species that ingested the same modal size of sand particles showed preferences for different food items. The shortest mean relative gut length (gut length to body length ratio) of 1.82 and 1.72 were calculated for L. dumerilii in the Volta and Pra estuaries, respectively, while the longest mean relative gut length of 4.56 was calculated for Mugil cephalus in the Volta estuary and 4.33 for Liza grandisquamis in the Pra estuary. All the species showed a diurnal feeding habit, with the main feeding period occurring between 08.00 and 12.00 h. The peak feeding time, however, differed among the species

Annealing tests of in-pile irradiated oxide coated U–Mo/Al–Si dispersed nuclear fuel

Authors do acknowledge the MERARG team for their experimental work (CEA) and F. Charollais, J. Noirot and finally B. Kapusta for their advices and comments. This study was supported by a combined Grant (FRM0911) of the Bundesministerium für Bildung und Forschung (BMBF) and the Bayerisches Staatsministerium für Wissenschaft, Forschung und Kunst (StMWFK).U–Mo/Al based nuclear fuels have been worldwide considered as a promising high density fuel for the conversion of high flux research reactors from highly enriched uranium to lower enrichment. In this paper, we present the annealing test up to 1800°C of in-pile irradiated U–Mo/Al–Si fuel plate samples. More than 70% of the fission gases (FGs) are released during two major FG release peaks around 500°C and 670°C. Additional characterisations of the samples by XRD, EPMA and SEM suggest that up to 500°C FGs are released from IDL/matrix interfaces. The second peak at 670°C representing the main release of FGs originates from the interaction between U–Mo and matrix in the vicinity of the cladding

Seasonal variation in food preference and feeding ecology of two juvenile marine fishes, Pseudotolithus senegalensis (Sciaenidae) and Brachydeuterus auritus (Haemulidae) off Cape Coast, Ghana

Aspects of the feeding habits and diet of juveniles of the cassava croaker Pseudotolithus senegalensis (Valenciennes, 1833) (Sciaenidae) and bigeye grunt Brachydeuterus auritus (Valenciennes, 1831) (Haemulidae) in the inshore waters of Cape Coast, Ghana are reported in the study. Both species had a similar diet consisting of larvae of fish, shrimps and cuttlefish. The croaker ingested prey up to 77% of its total length while the bigeye grunt consumed prey up to 70% of its total length. Analysis of the stomach contents, based on the frequency of occurrence, and numerical and gravimetric compositions of these food items indicated that shrimps were the main food of P. senegalensis while B. auritus fed mainly on fish. While shrimps constituted the predominant food of the croakers all-year-round, the bigeye grunts appeared to shift their preference for fish to shrimps from June to September. The results of the study are compared with those on croakers from other parts of the Gulf of Guinea. The study, however, appears to be the first to give a detailed account of the food preference and feeding ecology of the bigeye grunt

Accreting magnetars: a new type of high-mass X-ray binaries?

The discovery of very slow pulsations (Pspin=5560s) has solved the long-standing question of the nature of the compact object in the high-mass X-ray binary 4U 2206+54 but has posed new ones. According to spin evolutionary models in close binary systems, such slow pulsations require a neutron star magnetic field strength larger that the quantum critical value, suggesting the presence of a magnetar. We present the first XMM-Newton observations of 4U 2206+54 and investigate its spin evolution. We find that the observed spin-down rate agrees with the magnetar scenario. We analyse ISGRI/INTEGRAL observations of 4U 2206+54 to search for the previously suggested cyclotron resonance scattering feature at ~30 keV. We do not find a clear indication of the presence of the line, although certain spectra display shallow dips, not always at 30 keV. The association of these dips with a cyclotron line is very dubious because of its apparent transient nature. We also investigate the energy spectrum of 4U 2206+54 in the energy range 0.3-10 keV with unprecedented detail and report for the first time the detection of very weak 6.5 keV fluorescence iron lines. The photoelectric absorption is consistent with the interstellar value, indicating very small amount of local matter, which would explain the weakness of the florescence lines. The lack of matter locally to the source may be the consequence of the relatively large orbital separation of the two components of the binary. The wind would be too tenuous in the vicinity of the neutron star.Comment: accepted for publication in MNRA

Effect of Biozyme T.F. on yield and quality of tomato (Lycopersicon esculentum)

The effect of Biozyme T.F., a foliar fertilizer, on the growth and yield of tomato was determined. Plants were treated with Biozyme T.F. concentrations of 250, 500 and 700 cc ha-1. Plants treated with Biozyme T.F. increased percent fruit set, mean number of fruits per plant, fruit weight, fruit diameter, mean number of locules per fruit, and number of seeds per fruit. Applying Biozyme T.F., especially at 500 cc ha-1, resulted in significantly higher fruit yield. Biozyme T.F. did not affect fruit pH. Une expérience était entreprise pour déterminer l'effet de Biozyme T.F., un engrais foliaire, sur la croissance et le rendement de tomate. Les plantes étaient traitées avec Biozyme T.F. de concentrations de 250, 500 et 700 cc ha-1. Les plantes traitées de Biozyme augmentaient le pourcentage de nouaison de fruit, nombre moyen de fruit/plante, poids de fruit, diamètre de fruit, nombre moyen de loges / fruit et nombre de graines/fruits. Appliquant Biozyme T.F. surtout à 500 cc ha-1, résultait en un rendement de fruit considérablement plus élevé. Biozyme T.F. n'a pas touché le pH de fruit. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 113-11

A simple derivation of Kepler's laws without solving differential equations

Proceeding like Newton with a discrete time approach of motion and a geometrical representation of velocity and acceleration, we obtain Kepler's laws without solving differential equations. The difficult part of Newton's work, when it calls for non trivial properties of ellipses, is avoided by the introduction of polar coordinates. Then a simple reconsideration of Newton's figure naturally leads to en explicit expression of the velocity and to the equation of the trajectory. This derivation, which can be fully apprehended by beginners at university (or even before) can be considered as a first application of mechanical concepts to a physical problem of great historical and pedagogical interest

Managing Barriers to Online Learning: Towards a Framework for Resilient and Inclusive Virtual Classroom

This paper identifies the barriers to online learning faced by students and explores the strategies they employ to manage them in the face of this international crisis. From the narratives of the learners and the literature, a framework for a resilient and inclusive virtual classroom is developed. A descriptive mixed-method design is employed. Data are gathered from the students during the second term of SY2020-21 using a researchers-made questionnaire which is content, and face validated by experts and tested for reliability and consistency. The questionnaire is deployed online using the college’s official learning management system.In conclusion, the barriers to online learning as accounted for by the students are classified in this research into personal, educational, relational, technological, and social. On the other hand, the coping mechanisms employed are social support and accepting responsibility. At the center and front of the students’ struggles and successful handling of this emergency remote learning are the teachers. Thus, the respondents' barriers are dealt with primarily by themselves and their teachers who unleash the pedagogy of care that made them resilient during this pandemic. A caring and accommodating teacher and strong and flexible online learners are the primary components of a resilient and inclusive virtual classroom.The framework can be a template for designing future virtual classrooms and capacity-building activities to prepare teachers and learners for major education disruptions like this pandemic. Keywords: barriers, resilient, inclusive, educational, technological, virtual, framework DOI: 10.7176/JEP/14-12-04 Publication date: April 30th 202