7,014 research outputs found

    A Photovoice Evaluation of Coping Mechanisms Among Children of Immigrants

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    In this community based participatory research, photovoice was used to shine a light on the coping mechanisms of children of immigrants. Photovoice was chosen to give the children a platform to explore and identify how they cope with difficult circumstances and situations. Eight children were chosen by convenience sampling. Children were recruited from the after-school program offered by Puentes de Salud, a non-profit organization in South Philadelphia. Participants varied in ages from 7 to 12 years old or, 3rd through 5th grade. The primary purpose of the study was to (a) provide a deeper understanding of the coping mechanisms of vulnerable children whom experience adversity and (b) provide insight to Puentes de Salud, for them to implement and/or evaluate their activities to suit those coping mechanisms of the children. The study occurred over 5 sessions with parents and children. The children were given a disposable camera with 27 frames and were given the probing question: “What or who do you turn to when things go and get tough?” The three major themes that emerged from the pictures were: Culture, Friends and Family, and Puentes (the after-school program). This research shed light on the adversity faced by these children and how they try to cope with it. There was both personal buy-in and skepticism from this vulnerable populations, given the scope of the research project. Puentes de Salud can implement strategies and activities into their education program to teach effective coping mechanisms and styles

    Velocity profiles in viscoelastic drag reducing solutions

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    Turbulent velocity profiles in viscoelastic drag reducing solutions were measured using hot-film anemometer and Pitot tube techniques. Data were obtained in a solution of one per cent aluminium [sic] dioleate in toluene and in 0.2 and 0.4 per cent solutions of polyisobutylene (PIB) L-200 in cyclohexane. Velocity profiles were also obtained for comparison in toluene and cyclohexane by both techniques. By integrating the Pitot tube velocity profiles, large flow rate discrepancies between integrated and measured flow rates were found for the drag reducing polymer and soap solutions. This discrepancy was not observed in the hot-film anemometer measurements. The hot-film anemometer results indicated flatter profiles for the drag reducing soap solutions and steeper profiles for the drag reducing polymer solutions compared with the solvents. A plot of the anemometer data at the highest Reynolds numbers in the form of uâș versus log yâș indicated an increase of thickness in the boundary layer for both soap and polymer solutions --Abstract, page 1

    Stimulatory Effect of the Magnetic Treatment on the Germination of Cereal Seeds

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    The main objective of this study is to determine the effects of 125 mT magnetic treatment on the germination of different cereals seeds. This objective has a practical application in agriculture science: early growth of seeds. Germination tests were carried out under laboratory conditions by exposing seeds to magnetic field for different times. For each treatment the number of germinated seeds was counted to determine the time necessary to achieve the final maximum percentage of germinated seeds; rate of germination was assessed by determining the mean germination time (MGT) and parameters T1, T10, T25, T50, T75, T90, time required to germinate 1 - 90 percent of seeds. An increase in the percentage and rate of germination of seeds as positive response to magnetic field treatment in rice, wheat, maize and barley seeds have been found for all treatments applied. The mean germination time and parameters were reduced for all the magnetic treatments applied. Most significant differences were obtained for time of exposure of chronically exposure and 24 hours. External magnetic fields enhance seed vigor by influencing the biochemical processes by stimulating activity of proteins and enzymes. Numerous studies suggested that magnetic field increases ions uptake and consequently improves nutrition value

    An Experimental Investigation of the Integration of Smart Building Components with Building Information Model (BIM)

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    Building Information Modeling (BIM) is a methodology to digitally represent all the physical and functional characteristics of a building. Importantly, in smart buildings smart components that are enabled with sensing and actuation need to be modeled accurately within the BIM model. This data representation needs to include multiple status of the smart component based on their performance to guide the design and construction process. However, currently there is not a clear methodology or guideline on how to embed smart components in the BIM model. Visualization techniques have been developed based on CAD technology to integrate smart components in the building model but these techniques have not been applied to BIM environment. To accurately model smart components, the component must be more than a single status representation and must contain complete and accurate dynamic data of the smart component. In this research, data properties, visualization techniques, and categorization of smart components is investigated. Then, through an experimental investigation, nine smart components across five building disciplines are modeled and embedded in a BIM model of a smart space. The model includes parameters that facilitate the data representation of the smart components. Data properties, data organization, and simulation of the smart component within the building model is explained. Challenges and future research is discussed

    Theoretical design of stable small aluminium-magnesium binary clusters

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    We explore in detail the potential energy surfaces of the AlxMgy (x, y = 1–4) systems as case studies to test the utility and limitations of simple rules based on electron counts and the phenomenological shell model (PSM) for bimetallic clusters. We find that it is feasible to design stable structures that are members of this set of small Al–Mg binary clusters, using simple electron count rules, including the classical 4n + 2 HĂŒckel model, and the most recently proposed PSM. The thermodynamic stability of the title compounds has been evaluated using several different descriptors, including the fragmentation energies and the electronic structure of the systems. Three stable systems emerge from the analysis: the Al4Mg, Al2Mg2 and Al4Mg4 clusters. The relative stability of Al4Mg is explained by the stability of the Al42− subunit to which the Mg atom donates its electrons. Here the Mg2+ sits above the aromatic 10 π-electron Al42− planar ring. The Al2Mg2 and Al4Mg4 clusters present more complicated 3D structures, and their stabilities are rationalized as a consequence of their closed shell nature in the PSM, with 10 and 20 itinerant electrons, respectively

    Unsteady state series CSTR modeling of removal of ammonia nitrogen from domestic wastewater treated in a vertical flow constructed wetland

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    This work shows simulation results for subsurface vertical flow constructed wetland (VFCW) using a series CSTR model. The VFCW considered received the outflow from a domestic wastewater treatment plant. In addition, it was planted with Cyperus sp. and filter media was unsaturated. The model was based on an unsteady state mass balance for ammonia, nitrites, and nitrates, using one to three series CSTRs. Nitrogen transformation mechanisms considered were ammonification, nitrification, plant uptake and denitrification. The following effects were evaluated: the number of reacting CSTRs from one to three; the occurrence of the reaction in second and third CSTRs for the case that three CSTRs hold; the use of either equal or different values of reaction rate parameters between CSTRs; and the discretization of the reaction rate parameters. The inflow and outflow measurements of ammonium, nitrites, and nitrates were used for model calibration. The estimated parameters included the reaction rate coefficients and reactor water volume. The coefficient of determination (R2) evidenced a satisfactory capability of simulating outlet pollutant concentrations. Two and three reacting CSTRs achieved similar R2 value (0.54-0.55), whereas one reacting CSTR achieved an R2 of 0.39, and three CSTRs with reaction only in the first tank achieved an R2 of 0.42. Discretization of the nitrification rate for the case of two reacting CSTRs led to an R2 of 0.94. The parameter sensitivity analysis revealed a significant effect of model parameters on the R2 value

    Microsolvation of Mg2+, Ca2+: Strong influence of formal charges in hydrogen bond networks

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    A stochastic exploration of the quantum conformational spaces in the microsolvation of divalent cations with explicit consideration of up to six solvent molecules [Mg (H 2 O) n )]2+, (n = 3, 4, 5, 6) at the B3LYP, MP2, CCSD(T) levels is presented. We find several cases in which the formal charge in Mg2+ causes dissociation of water molecules in the first solvation shell, leaving a hydroxide ion available to interact with the central cation, the released proton being transferred to outer solvation shells in a Grotthus type mechanism; this particular finding sheds light on the capacity of Mg2+ to promote formation of hydroxide anions, a process necessary to regulate proton transfer in enzymes with exonuclease activity. Two distinct types of hydrogen bonds, scattered over a wide range of distances (1.35–2.15 Å) were identified. We find that in inner solvation shells, where hydrogen bond networks are severely disturbed, most of the interaction energies come from electrostatic and polarization+charge transfer, while in outer solvation shells the situation approximates that of pure water clusters

    Scorpions (Chelicerata) from Colombia. III. The scorpio-fauna of pacific region (Choco), with some biogeographic considerations

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    The tropical lowlands of the Choco region of western Colombia and adjacent Ecuador constitute the wettest part of the Neotropics and perhaps of the world. The fauna of this region has been poorly known until very recently. Progress on the study of the scorpion fauna of this region suggests an important species diversity with noticeable rates of endemism. Four families are present: Buthidae, Chactidae, Diplocentridae and Ischnuridae. Predominant distributional patterns show an Amazonian origin for most of the Buthidae and Chactidae species; Centruroides gracilis representing an exception. This species of Buthidae and Tarsoporosus kugleri anchicaya new subsspecies, the only Diplocentridae observed, have affinities with Central America. The only species of Ischnuridae present, Opisthacanthus lepturus, belongs to a Gondwanian group and has a complex origin. Scorpion biogeographic patterns in the Choco region today correspond closely with the observations of PRANCE (1982), HAFFER (1982) and GENTRY (1982), and complement previous conclusions regarding scorpion biogeography

    Cryogenic System for the Origins Space Telescope: Cooling a Large Space Telescope to 4K with Today's Technology

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    The Origins Space Telescope (OST) concept is one of four NASA Science Mission Directorate, Astrophysics Division, observatory concepts being studied for launch in the mid 2030's. OST's wavelength coverage will be from the midinfrared to the sub-millimeter, 6-600 microns. To enable observations at the zodiacal background limit the telescope must be cooled to about 4 K. Combined with the telescope size (currently the primary is 9 m in diameter) this appears to be a daunting task. However, simple calculations and thermal modeling have shown the cooling power required is met with several currently developed cryocoolers. Further, the telescope thermal architecture is greatly simplified, allowing simpler models, more thermal margin, and higher confidence in the final performance values than previous cold observatories. We will describe design principles to simplify modeling and verification. We will argue that the OST architecture and design principles lower its integration and test time and reduce its ultimate cost
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