3,379 research outputs found

    Chemistry Student Perceptions of Transferable & Workplace Skills Development

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    The perceptions of transferable and workplace skills development of year one and two chemistry undergraduate students at the University of Leicester were measured using two questionnaires. This group of students is taught be a variety of approaches including Problem and Context Based Learning (C/PBL). Over 60% of respondents agreed that all discipline specific and transferable skills included in the first questionnaire were important skills for chemistry graduates to have. The perceived importance of most skills does not vary between year groups but there are small increases in perceived importance for most transferable skills. In a separate questionnaire, first year students were asked to rate their skills development following a series of Context and Problem Based Learning (C/PBL) activities. "problem solving", "time management", "working in a team“ and "oral communication" were the most developed skills based on student responses. This element of the study also provided evidence to suggest that students believe the “real-world”, authentic nature of C/PBL problems may be an important factor in determining the extent of skills development.Keywords: Transferable skills, Workplace skills, Employability, Chemistry educatio

    The Physical Conditions and Dynamics of the Interstellar Medium in the Nucleus of M83: Observations of CO and CI

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    This paper presents CI, CO J=4-3, and CO J=3-2 maps of the barred spiral galaxy M83 taken at the James Clerk Maxwell Telescope. Observations indicate a double peaked structure which is consistent with gas inflow along the bar collecting at the inner Lindblad resonance. This structure suggests that nuclear starbursts can occur even in galaxies where this inflow/collection occurs, in contrast to previous studies of barred spiral galaxies. However, the observations also suggest that the double peaked emission may be the result of a rotating molecular ring oriented nearly perpendicular to the main disk of the galaxy. The CO J=4-3 data indicate the presence of warm gas in the nucleus that is not apparent in the lower-J CO observations, which suggests that CO J=1-0 emission may not be a reliable tracer of molecular gas in starburst galaxies. The twelve CI/CO J=4-3 line ratios in the inner 24'' x 24'' are uniform at the 2 sigma level, which indicates that the CO J=4-3 emission is originating in the same hot photon-dominated regions as the CI emission. The CO J=4-3/J=3-2 line ratios vary significantly within the nucleus with the higher line ratios occurring away from peaks of emission along an arc of active star forming regions. These high line ratios (>1) likely indicate optically thin gas created by the high temperatures caused by star forming regions in the nucleus of this starburst galaxy.Comment: 15 pages with 10 figures. To appear in the August 10 1998 issue of The Astrophysical Journa

    Short-term impacts of an unconditional cash transfer program on child schooling: Experimental evidence from Malawi.

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    This study analyzes the impact of a positive income shock on child schooling outcomes using experimental data from an unconditional cash transfer program in Malawi. Since households receive the cash and parents are responsible for making spending decisions, we also examine the intervening pathways between cash transfers and child schooling. Data comes from a cluster-randomized study of Malawi’s Social Cash Transfer Program (SCTP). After a baseline survey, households in village clusters were randomly assigned to treatment and control arms with treatment villages receiving transfers immediately and control villages assigned a later entry. We test for treatment impacts on a panel of school-aged children (6–17) using a differences-in-differences model. After a years’ worth of transfers, we find the Malawi SCTP both improves enrollment rates and decreases dropouts. The main intervening pathway between the program and schooling is education expenditures, suggesting that the cash improves the demand for education by reducing financial constraints

    Paying for Happiness: Experimental Results from a Large Cash Transfer Program in Malawi

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    This study analyzes the short-term impact of an exogenous, positive income shock on caregivers’ subjective well-being (SWB) in Malawi using panel data from 3,365 households targeted to receive Malawi’s Social Cash Transfer Program that provides unconditional cash to ultra-poor, labor-constrained households. The study consists of a cluster-randomized, longitudinal design. After the baseline survey, half of these village clusters were randomly selected to receive the transfer and a follow-up was conducted 17 months later. We find that the short-term impact of household income increases from the cash transfer leads to substantial SWB gains among caregivers. After a year’s worth of transfers, caregivers in beneficiary households have higher life satisfaction and are more likely to believe in a better future. We examine whether program impacts on consumption, food security, resilience, and hopefulness could explain the increase in SWB but do not find that any of these mechanisms individually mediate our results

    A Review on Optimizing Radial Basis Function Neural Network using Nature Inspired Algorithm

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    Radial Basis Function (RBF) is a type of feed forward neural network .This function can be applied to interpolation, chaotic time-series modeling, control engineering, image restoration, data fusion etc. In RBF network, parameters of basis functions (such as width, the position and number of centers) in the nonlinear hidden layer have great influence on the performance of the network. Common RBF training algorithms cannot possibly find the global optima of nonlinear parameters in the hidden layer, and often have too many hidden units to reach certain approximation abilities, which will lead to too large a scale for the network and decline of generalization ability. Also, RBF neural network has the advantages of adaptive and self-learning ability, but it is difficult to determine the number of hidden layer neurons, and the weights learning ability from hidden layer to the output layer is low; these deficiencies easily lead to decreasing learning ability and recognition precision. Secondly, the Swarm Intelligence Algorithms are (Meta-Heuristic) development Algorithms, which attracted much attention and appeared its ability in the last ten years within many applications such as data mining, scheduling, improve the performance of artificial neural networks (ANN) and classification. So, in this paper the work of Artificial Bee Colony (ABC), Genetic algorithm(GA), Particle swarm optimization(PSO) and Bat algorithm(BA) have been reviewed, which optimized the RBF neural network in their own terms

    Molecular Gas Kinematics in Barred Spiral Galaxies

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    To quantify the effect that bar driven mass inflow can have on the evolution of a galaxy requires an understanding of the dynamics of the inflowing gas. In this paper we study the kinematics of the dense molecular gas in a set of seven barred spiral galaxies to determine which dynamical effects dominate. The kinematics are derived from observations of the CO J=(1-0) line made with the Berkeley-Illinois-Maryland Association (BIMA) millimeter array. We compare the observed kinematics to those predicted by ideal gas hydrodynamic and ballistic cloud-based models of gas flow in a barred potential. The hydrodynamic model is in good qualitative agreement with both the current observations of the dense gas and previous observations of the kinematics of the ionized gas. The observed kinematics indicate that the gas abruptly changes direction upon entering the dust lanes to flow directly down the dust lanes along the leading edge of the bar until the dust lanes approach the nuclear ring. Near the location where the dust lanes intersect the nuclear ring, we see two velocity components: a low velocity component, corresponding to gas on circular orbits, and a higher velocity component, which can be attributed to the fraction of gas flowing down the bar dust lane which sprays past the contact point toward the other half of the bar. The ballistic cloud-based model of the ISM is not consistent with the observed kinematics. The kinematics in the dust lanes require large velocity gradients which cannot be reproduced by an ISM composed of ballistic clouds with long mean-free-paths. Therefore, even the dense ISM responds to hydrodynamic forces.Comment: To be published in the Astrophysical Journal, Nov. 20, 199

    Gas Dynamics in the LINER Galaxy NGC 5005: Episodic Fueling of a Nuclear Disk

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    We report high-resolution CO(1-0) observations in the central 6 kpc of the LINER galaxy NGC 5005 with the Owens Valley Radio Observatory millimeter array. Molecular gas is distributed in three components - a ring at a radius of about 3 kpc, a strong central condensation, and a stream to the northwest of the nucleus but inside the 3 kpc ring. The central condensation is a disk of about 1 kpc radius with a molecular gas mass of 2 x 10^9 M_sun. The stream between the 3 kpc ring and the nuclear disk lies on a straight dust lane seen in the optical. If this material moves in the plane of the galaxy, it has a velocity offset by up to ~ 150 km/s from galactic rotation. We suggest that an optically inconspicuous stellar bar lying within the 3 kpc ring can explain the observed gas dynamics. This bar is expected to connect the nuclear disk and the ring along the position angle of the northwest stream. A position-velocity cut in this direction reveals features which match the characteristic motions of gas in a barred potential. Our model indicates that gas in the northwest stream is on an x_1 orbit at the bar's leading edge; it is falling into the nucleus with a large noncircular velocity, and will eventually contribute about 2 x 10^8 M_sun to the nuclear disk. If most of this material merges with the disk on its first passage of pericenter, the gas accretion rate during the collision will be 50 M_sun/yr. We associate the nuclear disk with an inner 2:1 Lindblad resonance, and the 3 kpc ring with an inner 4:1 Lindblad resonance. The high rate of bar-driven inflow and the irregular appearance of the northwest stream suggest that a major fueling event is in progress in NGC 5005. Such episodic (rather than continuous) gas supply can regulate the triggering of starburst and accretion activity in galactic nuclei. (abridged)Comment: 26 pages, 12 figures, AASTeX, ApJ in press (Feb. 10, 2000). For full-resolution figures, see http://www.ovro.caltech.edu/mm/science/science.htm
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