Every spring the Graduate School Association sponsors a research symposium to present graduate research work to the VCU and local Richmond community. The event is an excellent opportunity for graduate students to present their original research and creative projects in a professional but relaxed environment. This is the only opportunity for many graduate students to showcase their work at VCU. Participation in this event has nearly doubled every year and attracts not only VCU students and faculty, but local media, legislators, and respected members of the Richmond business community.
Hasnain Ahmad, Supriyo Bandyopadhyay, and Jayasimha Atulasimha
We are experimenting on designing a voltage-controlled ultra-low-energy Magnetic Tunneling Junction (MTJ) device using a soft single domain magnetostrictive layer (i.e. Galfenol: Fe1-xGax , x = 20 At%) coupled to a piezoelectric layer (i.e. PMN-PT). Special metal pads have been designed using photolithography to generate stress in the PMN-PT layer by applying electric field. The patterns of different shape anisotropic nano-magnets are designed using e-beam lithography and we have successfully fabricate FeGa nanomagnets with only 12 to 13 nanometer thickness by sputter deposition. These nanomagnets have been characterized by magnetic force microscopy for observing their switching capabilities. Several nano-magnets have shown magnetization reversal after applying stress. Magnetic domain pinning, shape irregularity, irregular edges in the pattern, strain gradients across the FeGa etc. are several factors that we are still trying to optimize. The next step will be to deposit a tunneling oxide layer and hard ferromagnetic layer to complete the MTJ. These simple strain controlled MTJs can act as non-volatile NAND and NOR gate depending on the shape anisotropy barrier of the soft ferromagnetic layer (FeGa) and are extremely energy-efficient.
Nour Al Ghriwati, Marcia Winter, Robin Everhart, and Barbara Fiese
OBJECTIVE: Research shows that children with asthma are at risk for behavioral
maladjustment, particularly internalizing symptoms (McQuaid et al., 2001), and that negative parenting behavior compromises child mental and physical health (Lim et al., 2011). However, pathways of effect are not clear. This study examined the relation between critical/harsh parenting and child asthma severity. A model was tested to assess whether children’s internalizing symptoms mediate the relation between maternal rejection/harshness and asthma severity.
METHODS: 215 children with asthma (ages 5-12) and their families participated. Mothers reported child internalizing symptoms (CBCL) and functional asthma severity (CHAS); a Pediatric Pulmonologist reported lung function via spirometry results. Maternal criticism was observed in a 15-minute family activity; harsh/critical behavior was coded on a 1-5 scale.
RESULTS: We conducted bootstrapping analyses, with 5000 samples, to examine the indirect effect of maternal rejection/criticism on pulmonary functioning via child internalizing symptoms, while controlling for child age, SES, and adherence, using the PROCESS SPSS Macro (Hayes, 2013). The estimate of the indirect effect between maternal rejection/criticism and objective lung functioning was supported, with a point estimate of -.03 (SE = .02; 95% CI = -.0846 to -.0007). However, the estimate of the indirect effect between maternal rejection/criticism and subjective/parent-reported lung functioning was not supported.
CONCLUSION: Results support a theorized pathway, in which critical parenting indirectly affects a child’s lung functioning by increasing his/her internalizing symptoms (Wood et al., 2007). These findings only apply to objective physiological measures of asthma severity, perhaps suggesting a unique way that internalizing symptoms may impact lung functioning. Proposed psychological interventions include helping families understand connections between emotional and physical well-being, reducing critical parenting behavior, and treating child internalizing symptoms.
Virginia Organizing is a non-profit, non-partisan statewide grassroots community organization aimed at empowering people to affect change in their communities. They celebrated their 20th anniversary in 2015 and this process evaluation identifies the unique role that the Virginia Organizing State Governing Board has had in governing the organization. It determined the historical themes from this governing body’s 20 years of meeting minutes and assessed its membership diversity over time. In attempting to answer these questions: What themes emerge from the first 20 years of Virginia Organizing State Governing Board meeting minutes? How has the diversity of the membership of the State Governing Board of Virginia Organizing changed or not changed over time and is it presently diverse?, the study used a convergent parallel design from a mixed-methods approach to interpret the two sets of data in light of each other and in comparison to the literature on non-profit governance and board diversity. The Virginia Organizing State Governing Board has a keen awareness of the importance of diversity to the organization’s success and has made strides in assuring their own diversity for 20 years. This research contributes to the literature on board diversity, community organizing, and non-profit structure and affirms Virginia Organizing for their strategic efforts to maintain diversity.
In the age of technology, educators are encouraged to incorporate online resources into their teaching, but the impact of these resources on learning is rarely considered. To create a foundation for assessment, this poster reviews theories and research on how students learn across oral, written, and online modes of communication. It then reviews methods of assessing various elements of online resources. Lastly, this poster suggests an implementation approach to enhance the use of resources.
Tess K. Drazdowski and Wendy Kliewer
Recent results from a nationally representative sample indicated that young adults exhibited the greatest illicit drug use (SAMHSA, 2013b). The non-medical use of prescription drugs (NMUPD) is the second most commonly reported form of illicit substance use by young adults, preceded only by marijuana (SAMHSA, 2013b). This is a growing public health concern with an estimated 2.4 million Americans engaged in NUMPD for the first time within the past year in 2010, an average of 6,600 initiates per day (SAMHSA, 2013b). Prescription opioid abuse alone was estimated to cost the U.S. $55.7 billion in 2007 (Birnbaum et al., 2011). NMUPD has been linked with abuse and dependence, and a variety of other negative outcomes, including mental illness, (e.g., Bavarian et al., 2013), poor school performance (Arria et al., 2011), emergency room visits (SAMHSA, 2013a, 2013b), more frequent sexual risk behaviors (Benotsch et al., 2011), and death (CDC, 2012; Paulozzi et al., 2012). Additionally, young adults who engage in NMUPD are significantly more likely than their peers to use other illicit drugs and to combine prescription drugs with alcohol and other substances. These practices increase the risk of potentially dangerous drug interactions, and their negative outcomes (Garnier et al., 2009; McCabe et al., 2006; SAMHSA, 2006). Therefore, prevention is key to reducing this great public health concern and its grave costs to society. One way to prevent substance use and abuse is to investigate why specific groups of people use and to target interventions specifically to modifiable predictors. The current study focuses on such potential predictors.
The sample included 193 undergraduate students (70.4% female) from diverse ethnic groups (55% White) attending a large public university who endorsed NMUPD of either pain or stimulant medications in the past year. Participants completed an online questionnaire that assessed their ratings of their problematic NMUPD use, sleep problems, emotion regulation difficulties, depressive symptoms, and post-traumatic stress disorder (PTSD) symptoms from reliable and valid measures. Using regression models run separately for users of pain and stimulant medications, emotion regulation difficulties and PTSD symptoms were found to predict non-medical problematic use of both pain and stimulant medications (betas ranged from .22 - .32, ps < .05). Sleep problems and depressive symptoms were found to only predict problematic use of stimulants (betas = .33, ps < .01). When all the significant predictors were entered into a multiple regression for each prescription category, no one predictor was significant above and beyond other predictors (see Table 1). However, PTSD symptoms explained the most variance in both models.
These results suggest that all of these predictors are important to consider when investigating NMUPD in young adults. Since results from treatment research investigating abuse of other substances have found that integrated approaches that combine mental health and substance use are more effective than interventions that address substance use and mental health problems separately (e.g., Drake et al., 2008), future prevention and intervention efforts should consider all of the variables investigated. If resources are limited targeting PTSD symptoms may be the most effective.
Md Iftekhar I. Hossain, Supriyo Bandyopadhyay, Jayasimha Atulasimha, and Saumil Bandyopadhyay
We have proposed a spintronic infrared photodetector backed by experimental evidence and matched with theoretical prediction obtained in our labs. Unlike conventional photodetectors, it can work at room temperature with ideally infinite light-to-dark contrast ratio, infinite detectivity and zero dark current. The proposed idea is based on smart implementation of spin polarized transport. Electrons while travelling through one-dimensional channel show long spin relaxation length if they can be confined to a single conduction subband because of the elimination of major spin relaxation mechanism, namely the D’yakonov-Perel’ mechanism. With infrared light, electrons can be excited to higher subbands, resulting in the revival of DP mechanism which shortens the spin relaxation length. A noticeable change in current in a nanowire spin-valve (a semiconductor nanowire with two ferromagnetic contacts) can be observed due to this shortening and this phenomenon can be manipulated to implement infrared photo-detection. An array of tri-layer nanowires have been fabricated using electrodeposition where a narrow band semiconductor InSb has been sandwiched between two ferromagnetic contacts, Cobalt and Nickel. The two magnetic contacts act as spin injector and detector, where in the InSb layer, spin polarization is modulated using infrared light. The spin-valve effect and the Hanle effect have been demonstrated in these structures, which gives the confidence that the proposed device is indeed capable of injecting, coherently transporting and detecting spin of the electrons at room temperature even in the presence of thermal drift, background magnetoresistance, low spin injection and detection efficiency. When the same experiment was done under the infrared light, spin-valve effect was still there but muted, which means, infrared light is responsible weakening the spin polarization of carriers in the InSb layer. With choice of other materials, which show better spin injection and detection efficiency, the detectivity and sensitivity can be made more prominent.
Sarah E. Kleinman
Voz Alta is a participatory, voice-activated public light installation designed by Rafael Lozano-Hemmer as a memorial for the Tlatelolco massacre, which occurred on October 2, 1968 in the Plaza de las Tres Culturas in Tlatelolco, Mexico. In the Plaza, Lozano-Hemmer has synchronized a megaphone with a 10 kW Xenon robotic searchlight. As each participant speaks into the megaphone, the searchlight shines to the uppermost floor of the towering Centro Cultural Tlatelolco (CCT) building where three additional searchlights instantaneously strobe, dim, and brighten, illuminating the nocturnal landscape in horizontally fixed, tangential beams. Although the aesthetic, social, historical, and political aspects of Voz Alta have been discussed extensively in existing scholarship, the role of sound as a mechanism for power, control, and disruption has been sparsely addressed. This paper examines the metaphorical and literal manifestations of sound in Voz Alta and build upon Diana Sorenson’s discussion of the literary and verbal insurgencies that emerged after the massacre, as well as Michael Soldatenko’s analysis of the “oppositional imaginary,” which was catalyzed by the public in the informational vacuum imposed by the ruling Partido Revolucionario Institucional (PRI) regime. By incorporating the memory of a charged national event into spaces already imbued with meaning, Voz Alta operates on multiple levels, deliberately exceeding the parameters of artistic practice and becoming a platform for social activism. The paper’s aim is to achieve consensus on what Voz Alta achieves for its participants; its correlation and activation of memory associated with the massacre; and its potential to supplement the incomplete history that haunts the contemporary Mexican state.
“Rip It!”: A Juxtapositional and Critical Discourse Analysis of Gender Violence in 3 Tyler Perry Films
This qualitative study uses juxtapositional, intersectional and critical discourse analyses as one composite framework to assess Black female victimness and matriarchy in three Tyler Perry films. Findings exposed a transitional archetype model consisting of 5 domains (Victim, Bitterfruit, Matriarch, Forgiver and Princess) whereby victimized characters are portrayed using racist and sexist stereotypes. Additionally, rich juxtapositions in the films with regard to Black female victimness and matriarchy were also revealed. These juxtapositions play out in the transitional archetype model and reiterate a harmful racist gendered stereotype: strong, Black women (matriarchs) are not and cannot, by way of their strength, aggressiveness and violent dispositions be legitimate victims. This major finding, in addition to other findings based on the model and juxtapositional discourse analysis, expose important implications for social work practice, education and future scholarship.
An Implementation Evaluation of the Let Me Learn® Process: Leadership Practices and Cultural Conditions That Support Implementation and Sustainability
Lisa Webb, Anna Hebb, and Sarah Morris
In the 20 years since its development, the Let Me Learn Process® has been implemented in over 75 grade pre-Kindergarten through 12 schools in the United States. The Let Me Learn Process® is based on research in the field of neuroscience which explores the interface between the brain and the mind as it relates to learning (Bruer, 1997; Johnston, 2013). Throughout the twenty-year history of implementation, however, there has been no established approach to achieving implementation and sustainability of the Let Me Learn Process®. The client for this implementation evaluation was interested in better understanding the cultural conditions and leadership practices of those schools districts in which the Let Me Learn Process® has been implemented and sustained in order to formalize an implementation process. The methodology, a mixed-methods, convergent evaluation design, was used for data collection and analysis. Data was collected through interviews with school leaders and teachers, document review, and the administration of the School Cultural Elements Questionnaire (Cavanaugh and Dellar, 1998). These results were analyzed and then the evaluators reported on the extent to which they were related, divergent, and whether or not they could be combined to create a deeper understanding of the evaluation purpose. Finally, recommendations were made to the client in response to the evaluation purpose.
Nazanin R. Ghavamabadi
Between 20% to 50% of industrial energy input is lost as waste heat in the form of hot exhaust gases, cooling water and energy loss from generating equipment. Vibrations and variable heating are a common form of waste energy in motors, generators, power cables exposed to ambient temperatures, fuel exhausts from vehicles, and various types of heavy machinery. The recovery of even a fraction of this lost energy would have a transformational impact on the utility industry since the demand for energy is increasing and the impact of this demand on the environment is significant. Recent technical breakthroughs in new composite materials and energy storage devices make waste energy harvesting a practical alternative energy source. An energy harvesting system or harvester consists of a material such as a piezoelectric or pyroelectric composite to convert wasted heat or kinetic energy into electricity and the electronics and components for voltage conversion and energy storage.
In the current research we investigate and develop hybrid piezoelectric and pyroelectric systems to harvest waste energy. For this reason, six different experimental set up have been prepared to maximize the harvested energy for the hybrid case. Based on this work we provide a comprehensive review of the opportunities, potential scalability and practical limitations of energy harvesters as a new and potentially transformational alternative energy source. So, the wide-scale incorporation of energy harvesting systems to recover wasted heat and kinetic energy could have a dramatic impact on energy and environmental conservation efforts.
Negar Ghochaghi and Adetoun Taiwo
Electrospinning is a widely applicable technique that generates non-woven fibers in the micro and nano range. In this project two of its applications are highlighted namely filtration media and enhancement of wettability. The first project demonstrates that electrospinning can be used to produce new fiber filtration media with controlled microstructure. The bimodal and unimodal orthogonal and random filters were made and characterized against their filtration efficiency and pressure drop. Figure of Merit (FOM) was also calculated and discussed. It is shown that the FOM increases when the electrospun fibers are arranged into alternating layers of aligned course and fine fibers.
Secondly, surfaces were prepared by electrospinning thin, aligned polystyrene fibers onto a piezoelectric unimorph substrate. Results showed electric field induced changes in substrate curvature, which produced corresponding changes in surface wettability. From experiments, an average change in water contact angle of 7.2° ± 1.2° with 90% confidence was observed in ~2μm diameter fiber coatings electrospun for 5 minutes with applied electric field. In addition, fiber coatings electrospun with equivalent deposition showed average electric field induced changes in WCA of 2.5° ± 0.92° for lower diameter fibers (~1μm) and 3.5° ± 1.37° for higher diameter fibers (~2μm) with 90% confidence.