Adrian Villalta-Cerdas

Sam Houston State University | SHSU · Department of Chemistry

This investigation sought to elucidate the influence of students' academic legacy on their prior knowledge and course outcomes providing crucial insights for educators who teach general chemistry. This six-semester analysis involved 6,914 students enrolled in classes across nine Texas universities. Explored were personal circumstances associated wi...

The Networking for Science Advancement (NSA) team's institutions consist of nine universities located in one large southwestern state. This study evaluated students enrolled from Spring 2017 to Fall 2019 in first- and second-semester general chemistry. Over 90% of the students (n = 6,694) have been exposed to a secondary school isomorphic curriculu...

The Math-Up Skills Tests (MUST) has been used in multiple research projects conducted by the Networking for Science Advancement (NSA) team to determine how automaticity skills (what can be done without a calculator) in arithmetic can be used to predict if students will be successful (course average = 69.5%+) in general chemistry. This study expands...

This contribution reports the process and outcomes of a multiyear effort that supported institutions in reforming general chemistry using multidimensional learning approaches in the form of performance expectations. Performance expectations are based on evidence-centered assessment design principles and describe what learners should be able to do w...

One particular challenge in chemistry learning is developing students’ atomic level understanding of chemical processes. It is necessary to help students learn how to critique atomic models rather than accept them as “truth.” In this study, we used a resources-based framework to examine how students made sense of macroscopic level information to ac...

This mixed method study investigation uses eye tracking and qualitative analysis to investigate the impact of animation variation and visual feedback on the critique of submicroscopic representations of experimental phenomena. Undergraduate General Chemistry students first viewed an experimental video of a precipitation or oxidation reduction (redo...

The work herein presents a laboratory experience designed to foster clear connections between chemistry concepts, experimental measurements, and laboratory techniques. The experience consists of three different experiments to be completed in sequence over several laboratory sessions. First the density of the samples is determined, then the specific...

In this qualitative study, we examined how a group of seventeen first semester General Chemistry students responded when they were shown contrasting molecular animations of a reduction-oxidation (redox) reaction between solid copper and aqueous silver nitrate for which they first viewed a video of the actual experiment. The animations contrasted in...

Self-explaining refers to the generation of inferences about causal connections between objects and events for one's own consumption. Self-explaining is amongst the practices of science deemed essential for scientific competence; therefore, a valued learning outcome in itself. Nonetheless, generation of authentic explanations is seldom promoted in...

RateMyProfessors.com (RMP) is the most popular commercial website to evaluate instructors, and houses a wealth of student-generated information in the form of ratings and reviews. This study investigated whether general chemistry students who use RMP were different from other students, and their reasons to use and contribute to the site. A pool of...

Self-explaining refers to the generation of inferences about causal connections between objects and events. In science, this may be summarised as making sense of how and why actual or hypothetical phenomena take place. Research findings in educational psychology show that implementing activities that elicit self-explaining improves learning in gene...

The inflammatory effects of carbon nanoparticles (NPs) are highly disputed. Here it is demonstrated that endotoxin-free preparations of raw carbon nanotubes (CNTs) are very limited in their capacity to promote inflammatory responses in vitro, as well as in vivo. Upon purification and selective oxidation of raw CNTs, a higher dispersibility is achie...

This chapter focuses exclusively on the most recent electrochemical studies and advances toward promising applications of fullerenes and some of their closest relatives: endohedral metallofullerenes (EMFs) and carbon nano-onions (CNOs). C60 and C70 are the most abundant and consequently the subject of most research, but many different cage sizes an...

Commercial online instructor evaluations have gained traction in influencing students’ decisions on professor and course selections at universities. RateMyProfessors.com (RMP) is the most popular of such evaluation tools and houses a wealth of information from the students’ viewpoint. The purpose of this study was to determine whether RMP data coul...

The generation and evaluation of scientific evidence and explanations is a fundamental scientific competency that science education should foster. As a learning strategy, self-explaining refers to students’ generation of inferences about causality, which in science can be related to making-sense of how and why phenomena happen. Substantial empirica...

The prevalent trend in chemistry instruction relies on the “classroom game” which posits students in a passive role. In this model, the instructor does all the explaining (thinking), and learning is trivialized to knowing the correct answers (memorizing) and being able to produce them when prompted (regurgitating). Engaging learners in active self-...

The room temperature oxidation of carbon nano-onions (CNOs) with ozone was investigated. The reaction was performed under mild conditions and oxidized products with high concentrations of oxygen-containing functional groups were obtained. The reaction products were characterized by Boehm titrations, additional oxidant/reductant treatments, and Rama...

The electrochemical reactions of carboxylic and lactone groups on carbon nano-onions (CNOs) in aqueous solutions result in non-Kolbe products: alcohols, ketones, ethers and epoxides. The anodic/cathodic conversion of ox-CNOs was assessed by Boehm titrations and by Raman and DRIFTS-FTIR (diffuse reflectance infrared Fourier transform spectroscopy)....

With the constant growing complexity of electronic devices, the top-down approach used with silicon based technology is facing both technological and physical challenges. Carbon based nanomaterials are good candidates to be used in the construction of electronic circuitry using a bottom-up approach, because they have semiconductor properties and di...

The preparation and electrochemical properties of a novel type of composite made of small carbon nano-onions (CNOs) with poly(diallyldimethylammonium chloride) (PDDA) or chitosan (Chit) were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Composite films on glassy carbon electrode surfaces were deposited by a coating...