Manganese exposure from spring and well waters in the Shenandoah Valley: interplay of aquifer lithology, soil composition, and redox conditions.

Manganese (Mn) is of particular concern in groundwater, as low-level chronic exposure to aqueous Mn concentrations in drinking water can result in a variety of health and neurodevelopmental effects. Much of the global population relies on drinking water sourced from karst aquifers. Thus, we seek to assess the relative risk of Mn contamination in karst by investigating the Shenandoah Valley, VA region, as it is underlain by both karst and non-karst aquifers and much of the population relies on water wells and spring water.

Development and Evaluation of a Learning-based Model for Real-time Haptic Texture Rendering.

Current Virtual Reality (VR) environments lack the haptic signals that humans experience during real-life interactions, such as the sensation of texture during lateral movement on a surface. Adding realistic haptic textures to VR environments requires a model that generalizes to variations of a user's interaction and to the wide variety of existing textures in the world. Current methodologies for haptic texture rendering exist, but they usually develop one model per texture, resulting in low scalability.

Design and Evaluation of Haptic Guidance in Ultrasound-Based Needle-Insertion Procedures.

Objective: This article presents two haptic guidance systems designed to help a clinician keep an ultrasound probe steady when completing ultrasound-assisted needle insertion tasks. These procedures demand spatial reasoning and hand-eye coordination because the clinician must align a needle with the ultrasound probe and extrapolate the needle trajectory using only a 2D ultrasound image. Past research has shown that visual guidance helps the clinician align the needle, but does not help the clinician keep the ultrasound probe steady, sometimes resulting in a failed procedure.

Effects of Physical Hardness on the Perception of Rendered Stiffness in an Encountered-Type Haptic Display.

Rendering stable hard surfaces is an important problem in haptics; current haptic devices cannot render hard objects and free space together. In our previous work, we addressed these limitations using an encountered-type haptic display system, which showed significant improvements compared to traditional rendering methods. In our approach, we attach a plate with the desired hardness to the kinesthetic device's end-effector, which the user interacts with using an untethered stylus.

Electrochemistry of Uranyl Peroxide Solutions during Electrospray Ionization.

The ionization of uranyl triperoxide monomer, [(UO)(O)] (UT), and uranyl peroxide cage cluster, [(UO)(O)(OH)] (U), was studied with electrospray ionization mass spectrometry (ESI-MS). Experiments including tandem mass spectrometry with collision-induced dissociation (MS/CID/MS), use of natural water and DO as solvent, and use of N and SF as nebulizer gases, provide insight into the mechanisms of ionization. The U nanocluster under MS/CID/MS with collision energies ranging from 0 to 25 eV produced the monomeric units UO ( = 3-8) and UOH ( = 4-8, = 1, 2).