Physical Sciences and Mathematics Commons^™

Utilizing Concept Mapping As A Teaching And Learning Tool To Prepare For The Science Taks Test, Rosa Linda Zuniga

Theses and Dissertations - UTB/UTPA

Concept mapping was used with Donna High School students to determine its effect on the Texas Assessment of Knowledge and Skills (TAKS) test. Concept mapping was used with models such as the Sheltered Instruction Observation Protocol model (SIOP), the 5- E model, and the Learning Groups model. This measure was taken because the models used have not helped students improve their TAKS scores significantly. The findings of this research reveals that using the process of concept mapping together with the SIOP model helps students clearly see related concepts and motivates them to think more deeply. Students quickly realize what concepts …

Effects Of Adding An Enhanced Material Instructional Model To A Collaborative Grouping Instructional Strategy In A College Preparatory Chemistry Course, Chinyere Fidelia Shaw-Nnajiofor

Theses and Dissertations - UTB/UTPA

This research study investigated comparable academic achievement outcomes between an experimental group (EG) and a control group (CG) in a college preparatory chemistry course using a mixture of instructional pedagogies. The subjects comprised native and non-native English speakers, often identified as Limited English Proficiency (LEP) students. The study found no statistically significant difference between the pre-test scores of EG and CG students and a significant difference between the post-test scores of students in the experimental group compared to those of the control group. No significant difference was observed when comparing the test scores of the post-tests of the LEP-EG students …

Electrospinning Polystyrene Reinforced With Multi-Walled Carbon Nanotubes: Parameters For Obtaining Nanofibers With Enhanced Thermal Properties, Ana Veronica Rodriguez Ybarra

Theses and Dissertations - UTB/UTPA

Various concentrations of multi-walled carbon nanotubes (MWCNTs) were dispersed in a polystyrene matrix in order to determine the optimal MWCNT concentration that would enhance the thermal properties of the composite. The MWCNTs were dispersed in the polystyrene matrix by high energy sonication and then electrospun. The microstructural characterization such as fiber diameter, fiber orientation, fiber morphology, porosity, cross-section shape, and surface roughness of the nanofibers electrospun from these composites were made by scanning electron microscopy and transmission electron microscopy. Spectroscopic characterization for these nanofibers was conducted using Fourier Transform infrared spectroscopy and Raman spectroscopy was utilized to establish a nanotube/matrix …

Synthesis And Characterization Of Two Metal-Organic Frameworks, Roxanna Schaffino Moore

Theses and Dissertations - UTB/UTPA

Herein, the design and synthesis of two metal-organic frameworks, Zn 4O(FMA)3 (FMA = fumaric acid) and Zn2(CNC) 2(DPT) (CNC = 4-carboxycinnamic acid; DPT = 3,6-Di-4-pyridy1-1,2,4,5-tetrazine) via solvothermal methods are reported. Zn4O(FMA)3 was isolated as light yellow cubic crystals and Zn2(CNC)2(DPT) as light pink-block shaped crystals. The structures of both MOFs were characterized by single X-ray diffraction. Integrity of both MOFs were determined via powder X-ray diffraction and thermal gravimetric analysis. Zn4O(FMA) 3 is an isoreticular MOF exhibiting 6.8 Å pores taking up 5.2 wt % of hydrogen gas at 40 bar and 77K. Zn2(CNC)2(DPT) is a 3D primative cubic net …

Completing Chemistry Taks Objective 4(9d): The Effect Of Flash Animation, Judith B. Dano

Theses and Dissertations - UTB/UTPA

This study examines the effect of flash animation on learning effectiveness. The main goal of the study was to verify if using flash animation on learning chemistry concepts particularly Chemistry TAKS Objective 4 (9D) will have an impact on students learning achievement. The subjects in this study were 10th grade students from PSJA Memorial High School. Two class sections were randomly assigned as the treatment group each with 20 subjects (n=40) and another two class sections were assigned as the control group (n=40). The treatment group was exposed to flash animation while the control group had the traditional lecture type …

Electronic Spectroscopy And Dissociation Dynamics Of Gasphase Transition Metal Containing Cations And Dications, Kanchana Manori Perera

Doctoral Dissertations 1896 - February 2014

Studies of gas-phase ionic clusters have become an integral component in understanding microsolvation and catalysis by transition metal cations. Further interest in this field is due to the possibility of bridging the gap between the condensed and gas phases by developing our understanding of clusters and the possibility that small clusters can have unique chemical and catalytic properties. Most gas phase studies have focused on singly charged ions. Electrospray allows for the production of multiply charged ions solvated by a few solvent molecules. Understanding smaller reactive species such as metal centered clusters with well-defined, gas phase conditions also allows for …

Molecular Designs Toward Improving Organic Photovoltaics, Arpornrat Nantalaksakul

Doctoral Dissertations 1896 - February 2014

Organic photovoltaics (OPVs) that have been studied to date have poor power conversion efficiencies. This dissertation focuses on various molecular designs that could lead to both a fundamental understanding of photoinduced charge separation at a molecular level and also provide a solution to improve bulk properties of organic materials to overcome the poor efficiencies of OPV devices.

The effect of molecular architectures on the efficiency of electron transfer, a primary step in OPVs functioning, is evaluated in this work. We have shown that even though dendrimer provides an interesting architecture for efficient electron transfer due to the presence of multiple …

Functionalized Nanoparticles For Biological Imaging And Detection Applications, Bing C Mei

Doctoral Dissertations 1896 - February 2014

Semiconductor quantum dots (QDs) and gold nanoparticles (AuNPs) have gained tremendous attention in the last decade as a result of their size-dependent spectroscopic properties. These nanoparticles have been a subject of intense study to bridge the gap between macroscopic and atomic behavior, as well as to generate new materials for novel applications in therapeutics, biological sensing, light emitting devices, microelectronics, lasers, and solar cells. One of the most promising areas for the use of these nanoparticles is in biotechnology, where their size-dependent optical properties are harnessed for imaging and sensing applications. However, these nanoparticles, as synthesized, are often not stable …

The Effect Of Adsorbent Geometry And Surface Chemistry On Hplc Retention, Zhaoxia Liu

Seton Hall University Dissertations and Theses (ETDs)

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