Electron energy-loss spectrometry on lithiated graphite

Transmission electron energy-loss spectrometry was used to investigate the electronic states of metallic Li and LiC6, which is the Li-intercalated graphite used in Li-ion batteries. The Li K edges of metallic Li and LiC6 were nearly identical, and the C K edges were only weakly affected by the presence of Li. These results suggest only a small charge transfer from Li to C in LiC6, contrary to prior results from surface spectra obtained by x-ray photoelectron spectroscopy. Effects of radiation damage and sample oxidation in the transmission electron microscopy are also reported

Study of behavioral modifications resulting from exposure to high let radiation

Animal irradiations, behavioral studies, neurological studies, and nuclear medicine studies are discussed

Helicopter Parents of Community College Students: How Community College Professionals Operationally Define and Address This Phenomenon

This study examined whether the phenomenon of parental over-involvement occurred in the Virginia Community College System. Concern has been expressed in the popular and academic literature in recent years over the increased level of parental involvement at four year institutions whose student bodies consist almost exclusively of traditional-aged students. With a mix of traditional-aged and non-traditional students at community colleges, this study investigated whether or not community college employees expressed similar concerns as their counterparts at senior institutions. The study was designed using a mixed methods approach and utilized a triangulation of results in order to answer four research questions. 1) How do student services staff and administrators in Virginia community colleges define parental over-involvement? 2) To what extent does parental over-involvement exist in Virginia community colleges? 3) How do Virginia community colleges respond to over-involved parents? And 4) how do student services staff and administrators in Virginia community colleges describe an ideal collaboration with parents? Results of the study led to the development of an operational definition of helicopter parent that has been absent in the literature. In addition, the study showed that over-involved, or helicopter, parents were an increasing presence at Virginia\u27s community colleges. College student services employees who participated in the study indicated that their colleges had done very little to respond to this growing segment of involved parents and they were still learning how to work collaboratively with parents in order to ensure the best environment for student academic success and personal development. Student services employees expressed an interest in receiving systematic training and administrative support with respect to developing positive ways to work with students and their over-involved parents. The investigator developed a Collaborative Student Support Model for Student Services Employees, Students, & Parents as a suggestion on how to partner with parents to help support student academic success and psychosocial development

Electrochemical Evaluation of LaNi_(5–x)Ge_x Metal Hydride Alloys

We report a detailed evaluation of Ge-substituted LaNi_5 for electrochemical application as a negative electrode in alkaline rechargeable cells. Alloys with small substitutions of Ge for Ni show operating pressures, chargeability, cyclic lifetime, and kinetics for hydrogen absorption and desorption all superior to those found in many other substituted LaNi_5 alloys. These improved properties were achieved with a minimal reduction in hydrogen storage capacity

Electrochemical Studies on LaNi5–xSnx Metal Hydride Alloys

Electrochemical studies were performed on LaNi5–xSnx with 0 <= x <= 0.5. We measured the effect of the Sn substituent on the kinetics of charge-transfer and diffusion during hydrogen absorption and desorption, and the cyclic lifetimes of LaNi5–-xSnx electrodes in 250 mAh laboratory test cells. We report beneficial effects of making small substitutions of Sn for Ni in LaNi5 on the performance of the metal hydride alloy anode in terms of cyclic lifetime, capacity, and kinetics. The optimal concentration of Sn in LaNi5–xSnx alloys for negative electrodes in alkaline rechargeable secondary cells was found to lie in the range 0.25 <= x <= 0.3

Electrochemical Properties of LaNi5–xGex Alloys in Ni-MH Batteries

Electrochemical studies were performed on LaNi5–xGex metal hydride alloys with 0 <= x <= 0.5. We carried out single-electrode studies to understand the effects of the Ge substituent on the hydrogen absorption characteristics, the electrochemical capacity, and the electrochemical kinetics of hydrogen absorption and desorption. The electrochemical characteristics of the Ge-substituted alloys are compared to those of the Sn-substituted alloys reported earlier. LaNi5–xGex alloys show compositional trends similar to LaNi5–xSnx alloys, but unlike the Sn-substituted alloys, Ge-substituted alloys continue to exhibit facile kinetics for hydrogen absorption/desorption at high solute concentrations. Cycle lives of LaNi5–xGex electrodes were measured in 300 mAh laboratory test cells and were found to be superior to the Sn-substituted LaNi5 and comparable to a Mm(Ni,Co,Mn,Al)5 alloy. The optimum Ge content for LaNi5–xGex metal hydride alloys in alkaline rechargeable cells is in the range 0.4 <= x <= 0.5