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Fabrication and characterization of cellulose acetate nanofibers
No full textIn this study, CA fibers were fabricated using electrospinning technique with the mixture of acetic acid/acetone as the solvent system with the ratio of 3:1. The morphological structure of the fibers obtained was observed using scanning electron microscope (SEM). The SEM results showed that 10% of CA produced beads only, 12% of CA produced spindle beads with few fibers, 13% of CA produced fibers with few beads and 14% w/v concentration of CA produced continuous and smooth ribbon-like fibers with average diameter of 199.23nm
Natural-synthetic polymer blend composite scaffold for bone tissue engineering: Study of in vitro degradation and protein adsorption
No full textIn the current study, poly(hydroxy butyrate-co-hydroxy-valerate) (PHBV) was blended with a synthetic polymer poly (L-lactic acid) (PLLA), to control the degradation rate and process of composite scaffolds, as PLLA has a much higher degradation rate than PHBV. PHBV/PLLA blends were used as polymer matrices for composite scaffolds. Emulsion freezing/freeze-drying technique was used to fabricate composite scaffolds based on these blends and containing nano-sized hydroxyapatite (nHA). In vitro degradation tests of composite scaffolds were conducted by immersing samples in phosphate buffered saline (PBS) for various periods of time. It was found that the composition of polymer blends affected water uptake of scaffolds. Composite scaffolds exhibited enhanced adsorption of bovine serum albumin (BSA), a model protein. © (2014) Trans Tech Publications, Switzerland
Fabrication and in vitro evaluation of nanosized hydroxyapatite/chitosan- based tissue engineering scaffolds
No full textComposite scaffolds based on biodegradable natural polymer and osteoconductive hydroxyapatite (HA) nanoparticles can be promising for a variety of tissue engineering (TE) applications. This study addressed the fabrication of three-dimensional (3D) porous composite scaffolds composed of HA and chitosan fabricated via thermally induced phase separation and freeze-drying technique. The scaffolds produced were subsequently characterized in terms of microstructure, porosity, and mechanical property. In vitro degradation and in vitro biological evaluation were also investigated. The scaffolds were highly porous and had interconnected pore structures. The pore sizes ranged from several microns to a few hundred microns. The incorporated HA nanoparticles were well mixed and physically coexisted with chitosan in composite scaffold structures. The addition of 10% (w/w) HA nanoparticles to chitosan enhanced the compressive mechanical properties of composite scaffold compared to pure chitosan scaffold. In vitro degradation results in phosphate buffered saline (PBS) showed slower uptake properties of composite scaffolds. Moreover, the scaffolds showed positive response to mouse fibroblast L929 cells attachment. Overall, the findings suggest that HA/chitosan composite scaffolds could be suitable for TE applications. © 2014 Tao Sun et al
Analysis of power flow on power system with wind power grid
No full textWith the continuous development of wind energy resources, wind power technology has been integrated into the modern power system. In this paper, according to the Power System Incorporating Wind Farm, selecting typical data distributed Power flow calculation of Built power network. According to data from the results show that grid-connected wind power system, Due to the directly affected by the influence of the wind speed size into the injection power, cause the whole trend distribution network is presented in a state of random changes, thereby affecting the network power loss of change. In order to improve the network voltage change, this paper puts forward some feasible measures to improve the network voltage method. © (2014) Trans Tech Publications, Switzerland
Panther - January 2014 - Vol. XCIV No. 11
Get PDFhttps://digitalcommons.pvamu.edu/pv-panther-newspapers/1404/thumbnail.jp
Panther - February 2014 - Vol. XCIV No. 13
Get PDFhttps://digitalcommons.pvamu.edu/pv-panther-newspapers/1398/thumbnail.jp
The relationship between intrinsic motivation and academic achievement for first generation Latino college students
No full textHispanic students are pursuing higher education more than in previous years and they often represent their family as the first member to attend college (Strage in Coll Stud J 33:198-205, 1999). Past educational research has studied the influence of intrinsic motivation on academic achievement in various ethnically diverse elementary, middle school and high school student populations (Areepattamannil in Soc PsycholEduc 15:367-386, 2012; Crumpton and Gregory in J Educ Psychol 104:42-53, 2011; Lepper et al. in J Educ Psychol 92:184-196, 2005). Despite the fact that many studies using college student samples have also shown the positive role of intrinsic motivation with achievement outcomes (Harackiewicz et al. in Educ Psychol 33:1-21, 1998; Simons et al. in Br J Educ Psychol 74:343-360, 2004; Vallerand and Bissonnette in J Pers 60:599-620, 1992), few studies focus on Latino samples. We expect that intrinsic motivation may play an important role in the academic achievement of Latino students, particularly first generation college students. The current review will examine self-determination theory, including intrinsic motivation and extrinsic motivation, as well as relevant research pertaining to the connection between intrinsic motivation and academic achievement. The relationship between intrinsic motivation and academic achievement for first generation Latino college students will be examined along with ways to increase intrinsic motivation and academic achievement in turn. Implications for future research will be discussed. © 2014 Springer Science+Business Media Dordrecht
The Juvenile Adjudicative Competence Interview (JACI): Current Usage in Juvenile Competence to Stand Trial Evaluations
Get PDFExperimental Community-Based Interventions for Delinquent Youth: An Evaluation of Recidivism and Cost-Effectiveness
Get PDFInterception losses in three non-native Hawaiian forest stands
No full textInterception losses in stands of non-native trees in Hawaiian forests and their potential negative impacts on fresh water availability are poorly understood. In this study, a canopy water balance analysis was conducted to estimate interception losses using measurements of rainfall (RF), throughfall (TF), and stemflow (SF) at three locations, each dominated by one or more of the following non-native tree species: Psidium cattleianum Sabine (Strawberry guava), Schinus terebinthifolius Raddi (Christmas berry), Syzygium cumini (L.) Skeels (Java plum), and Coffea arabica L. (Coffee). Mean TF expressed as percentage of total RF was the lowest (43.3%) under a monotypic stand of P. cattleianum and the highest (56.5%) under mixture of S. terebinthifolius, P. cattleianum, and S. cumini. Observed SF was highest (33.9%) under P. cattleianum and lowest (3.6%) under a mixture of S. terebinthifolius, P. cattleianum, and S. cumini. The relatively high SF under P. cattleianum can be attributed to its smooth bark, stem density, and steep branching. The mean observed canopy interception varied between 23% under P. cattleianum and 45% at the site dominated by C. arabica. Mean direct TF coefficients from individual events at each location ranged from a low of 0.36 under the canopy dominated by C. arabica to a high of 0.51 under the canopy dominated by S. terebinthifolius, P. cattleianum, and S. cumini. In contrast, the mean SF partitioning coefficients from individual storm events at each location ranged from a low of 0.05 under the canopy dominated by S. terebinthifolius, P. cattleianum, and S. cumini to a high of 0.37 under P. cattleianum. Mean canopy storage capacity was highest (1.90) at the site dominated by S. terebinthifolius, P. cattleianum, and S. cumini whereas trunk storage capacity was highest (0.54) under the P. cattleianum. © 2012 John Wiley & Sons, Ltd