40 research outputs found
Philip Loring Gillett, a manuscript by Hanbin Choi (ca. 2013)
No full textThis 9 page manuscript is titled "Phillip Loring Gillett" and was written by Hanbin Choi, ca. 2013. The manuscript gives biographical information on Philip Gillett, a Springfield College graduate of 1901, a timeline of his life, and a listing of the materials he used in his research. The document was created for a class assignment for the Heritage and Value of Sport class given at Springfield College.Philip Loring Gillett graduated from Colorado College in 1891 and went on to attend Yale Divinity School. After graduating from Springfield College, he was hired as the general secretary for the YMCA’s International Committee for Korea, where he is widely credited with introducing baseball and basketball. Gillett continued to serve in this capacity in Shanghai, China (1913-1915), Nanking, China (1915-1930), and Taiwan (1931-1932). On October 21, 1932, he retired. Gillett died November 26, 1938
Self-Powered Real-Time Temperature Sensing Based on Flexible Ionic Elastomer on Triboelectric Nanogenerators
No full textSelf-powered flexible thermal-management systems have garnered interests in wearable electronic devices and AI semiconductors. However, their efficiency and reliability remain limited in practical applications. In this study, an ionic temperature-sensing triboelectric nanogenerator (iTS-TENG) is proposed with an ionic elastomer containing thermoplastic polyurethane (TPU) and ionic liquids (ILs). The TPU matrix undergoes deformation of microphase separation by thermal stimulation near the glass transition temperature. Furthermore, ILs facilitate the formation of electrical double layers as charge carriers and enhance the thermal sensitivity as heat carriers under mechanical and thermal stimuli. Thus, iTS-TENG demonstrates enhanced outputs (734 V) and high thermal sensitivity (3.87 V/degrees C) from room temperature to 70 degrees C, with fast response time and reproducibility (more than 20 cycles). Finally, real-time and self-powered iTS-TENG is demonstrated, showing that the sensed temperature is comparable to a commercial temperature sensor. These results indicate that iTS-TENG is suitable for thermal-management applications in self-powered wearable electronic systems.
The study of the P4-ATPase, ATP8A2, investigating disease-causing mutants and methods for high throughput production and purification
No full textHuman diseases have been linked to genetic mutations, causing the inability of proteins to function properly. Of these proteins, membrane proteins are crucial for the function of a cell; thus, a mutation affecting these classes of proteins causes extensive harm. This study was focused on the phospholipid transporter P₄-ATPase, ATP8A2, investigating the effects of mutations associated with human diseases. Six associated mutants have been studied: I376M, K429M, K429N, A544P, R625W, and W702R. The study allowed us to differentiate between two classes of mutants: proteins which fold in a native-like conformation allowing export from endoplasmic reticulum (ER), but lacking activity; and proteins that are highly misfolded, retained in the ER, and are rapidly degraded by proteasomes.
The well-studied P2-ATPases transport small ion substrates, whereas P4-ATPases transport much larger substrates across the plasma membrane (PM). ATP8A2 was further studied with its β-subunit, CDC50A, to develop a high expression system for protein structural studies. The use of 20 mM CHAPS and 0.04% GDN was the best combination of detergents to solubilize HEK 293F cells with sonication and stirring at 4°C for 45 minutes for maximal purification. Samples analyzed under a transmission electron microscope (TEM) were monodispersed and non-aggregated; however, the same peptidisc-reconstituted sample was aggregated by cryo-electron microscopy (cryo-EM). Further studies are required to prevent aggregation during freezing of ATP8A2-CDC50A for analysis by cryo-EM.Medicine, Faculty ofBiochemistry and Molecular Biology, Department ofGraduat
Skin-inspired electrochemical tactility and luminescence
No full text© 2022Animal skin is deformable, yet capable of consistently sensing external stimuli (mechanical, thermal, chemical) without morphological and functional deterioration. This high deformability and signal stability are ensured because the receptors and the signal transmission systems are based on the electrochemical change in the embedded cells. Further, in the skin of various nocturnal animals and deep-sea creatures, electrochemical changes triggered by mechanical stimuli lead to bioluminescence, which can be effective or direct visual feedback that responses to environmental stress in the biological system. In this regard, recently, researches to artificially imitate electrochemical mechanisms of tactile sensation and luminescence in the skin have made remarkable advances in the field of electronic skin (e-skin). This perspective article introduces recent pivot advances in the ion-based tactile sensors and electrochemiluminescent skins, and suggests the technological challenges, then the article ends with perspectives to the skin-inspired ionic artificial devices.11Nsciescopu
A reconfigurable piezo-ionotropic polymer membrane for sustainable multi-resonance acoustic sensing
No full textAbstract Sensorineural hearing loss is the most common form of deafness, typically resulting from the loss of sensory cells on the basilar membrane, which cannot regenerate and thus lose sensitivity to sound vibrations. Here, we report a reconfigurable piezo-ionotropic polymer membrane engineered for biomimetic sustainable multi-resonance acoustic sensing, offering exceptional sensitivity (530 kPa-1) and broadband frequency discrimination (20 Hz to 3300 Hz) while remaining resistant to “dying”. The acoustic sensing capability is driven by an ion hitching-in cage effect intrinsic to the ion gel combined with fluorinated polyurethane. In this platform, the engineered ionotropic polymer stretches under acoustic vibrations, allowing cations to penetrate the widened hard segments and engage in strong ion-dipole interactions (cation···F), thereby restricting ion flux and amplifying impedance changes. Additionally, the sensor’s sustainability is ensured through its self-healing properties and hydrophobic components, which enable effective self-repair in both conventional and aqueous environments without ion leakage, achieving a room-temperature healing speed of 0.3–0.4 μm/min. This sustainable acoustic sensing technology enables the devices to reliably identify specific sounds in everyday environments (e.g., human voices, piano notes), demonstrating their potential application as artificial basilar membranes
Radial growth response of Pinus densiflora and Quercus spp. to topographic and climatic factors in South Korea
No full textThis study aimed to develop radial growth models and to predict the potential spatial distribution of Pinus densiflora (Japanese red pine) and Quercus spp. (Oaks) in South Korea, considering topographic and climatic factors. We used a dataset of diameter at breast height and radial growth estimates of individual trees, topographic and climatic factors in systematic sample plots distributed over the whole of South Korea. On the basis that radial growth is attributed primarily to tree age, we developed a radial growth model employing tree age as an explanatory variable. We estimated standard growth (SG), defined as radial growth of the tree at age 30, to eliminate the influence of tree age on radial growth. In addition, SG estimates including the Topographic Wetness Index, temperature and precipitation were calculated by the Generalized Additive Model. As a result of variogram analysis of SG, we found spatial autocorrelation between SG, topographic and climatic factors. Incremental temperature had negative impacts on radial growth of P. densiflora and positive impacts on that of Quercus spp. Precipitation was associated with positive effects on both tree species. Based on the model, we found that radial growth of P. densiflora would be more vulnerable than that of Quercus spp. to climatic factors. Through simulation with the radial growth model, it was predicted that P. densiflora stands would be gradually replaced with Quercus spp. stands in eastern coastal and southern regions of South Korea in the future. The models developed in this study will be helpful for understanding the impact of climatic factors on tree growth and for predicting changes in distribution of P. densiflora and Quercus spp. due to climate change in South Korea
Liquid-Phase Templateless Synthesis of Pt-on-Pd0.85Bi0.15 Nanowires and PtPdBi Porous Nanoparticles with Superior Electrocatalytic Activity
No full textThis article reports the synthesis of Pt-on-Pd0.85Bi0.15 nanowires (NWs) and PtPdBi porous nanoparticles (PNPs) by a facile, one-pot, wet-chemical, and templateless method in the presence of oleylamine (OAm) and NH4Br. The relationship between the morphology and composition in the PtPdBi trimetallic system was systematically studied. Interestingly, it is verified that adding only 5% Bi will produce Pd NWs, which offers a novel approach to synthesize Pd NWs in the oil phase without any template. On the basis of the fact of synthesizing Pd0.85Bi0.15 NWs, Pt-on-Pd0.85Bi0.15 NWs with hetero-nanostructures were successfully synthesized by a one-step method. Furthermore, the number of Pt nanobranches for Pt-on-Pd0.85Bi0.15 NWs could be easily controlled via simply changing the synthetic parameters, which could tune the catalytic properties. PtPdBi PNPs were obtained by the acid pickling of PtPdBi2 intermetallic compounds. Most importantly, a catalytic study indicates that the as-obtained Pt-on-Pd0.85Bi0.15 NWs and PtPdBi PNPs exhibited much higher electrocatalytic activity and durability for the oxygen reduction reaction (ORR) than the commercial Pt/C catalyst. We expect that this work will provide a promising strategy for the development of efficient ORR electrocatalysts and can also be extended to the preparation of other nanowires or hetero-nanostructures with desirable functions.Chemistry, PhysicalMaterials Science, MultidisciplinarySCI(E)EI17ARTICLE3457-4652
Numerical analysis of the effect of the scan strategy on the residual stress in the multi-laser selective laser melting
No full textThe inevitably formed residual stress in the Selective Laser Melting (SLM) process leads to distortion, crack and even delamination of the workpiece. Single laser is commonly applied during SLM processing. However, its productivity is much lower than multiple lasers. In addition, the research of residual stress with multi-laser condition currently is limited in the open documents. In this paper, a three-dimensional (3D) thermo-mechanical model, with considerations of temperature dependent properties of Ti-6Al-4V, phase change and convective flow, is developed at first. Then, the numerical results of maximum temperature and dimensions of the molten pool are validated by available experimental data. Furthermore, a parametric study in regards to a series of scan strategies is investigated. According to the simulation results, the residual stress increases significantly when the laser number reaches four. The “two-zone technique” scan strategy decreases the equivalent residual stress by 10.6% compared to the successive scan strategy. With a shortening scan length, the residual stress first increases slightly, then decreases dramatically and attains the minimum when it is a quarter. Furthermore, for the multi-laser SLM process, carefully planning the scanning sequence and the sweeping direction to decrease heat concentration is beneficial in controlling the residual stress.Support Marine and Transport Techolog
Synthesis and electrocatalytic properties of PtBi nanoplatelets and PdBi nanowires
No full textWe have demonstrated a one-pot, facile and rapid strategy to synthesize novel PtBi nanoplatelets (NPLs) and PdBi nanowires (NWs) with controlled shape, size, and composition in the presence of oleylamine (OAm) and NH4Br. In contrast to the conventional face centered cubic (fcc) structure of Pt-based NPs, PtBi possesses a chemically ordered intermetallic hexagonal dose packed (hcp) structure. Using this uniaxial crystal structural character of PtBi, we succeed in synthesizing two-dimensional (2-D) PtBi NPLs. Significantly, the electrochemical studies indicate that the as-prepared 2-D PtBi NPLs exhibit enhanced electrocatalytic activity toward formic acid and methanol oxidation with Larger oxidation current density, higher tolerance to CO poisoning, and more negative onset potential in comparison with the commercial Pt/C catalyst. This is attributed to the addition of second metal Bi. In addition, to the best of our knowledge, this is the first time that synthesis of one-dimensional (1-D) PdBi alloy NWs has been reported. The as-synthesized 1-D PdBi bimetallic NWs may find promising potential applications in various fields, such as fuel cells, electrochemical sensors, and organocatalysis.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000328892300055&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Chemistry, MultidisciplinaryNanoscience & NanotechnologyMaterials Science, MultidisciplinaryPhysics, AppliedSCI(E)[email protected]
