Nonlinear Dynamics of Capacitive Charging and Desalination by Porous Electrodes

The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by super-capacitors, water desalination and purification by capacitive deionization (or desalination), and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or specific adsorption of ions) in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory in the case of a dilute, symmetric, binary electrolyte using the Gouy-Chapman-Stern (GCS) model of the double layer, for which simple formulae are available for salt adsorption and capacitive charging of the diffuse part of the double layer. We solve the full GCS mean-field theory numerically for realistic parameters in capacitive deionization, and we derive reduced models for two limiting regimes with different time scales: (i) In the "super-capacitor regime" of small voltages and/or early times where the porous electrode acts like a transmission line, governed by a linear diffusion equation for the electrostatic potential, scaled to the RC time of a single pore. (ii) In the "desalination regime" of large voltages and long times, the porous electrode slowly adsorbs neutral salt, governed by coupled, nonlinear diffusion equations for the pore-averaged potential and salt concentration

Multiple self-healing Bloch surface wave beams generated by a two-dimensional fraxicon

Two-dimensional surface waves are a cornerstone for future integrated photonic circuits. They can also be beneficially exploited in sensing devices by offering dark-field illuminations of objects. One major problem in sensing schemes arises from the individual sensing objects: the interaction of surface waves with an object reduces the field amplitude, and the readout of other objects along the propagation path suffers from this reduced signal. Here we show in two experiments that nondiffracting and self-healing Bloch surface waves can be launched using a Fresnel axicon (i.e., fraxicon). First, we visualize the generation of an array of multiple focal spots by scanning near-field optical microscopy in the infrared. With a second device operating in the visible, we demonstrate the self-healing effect directly using a far-field readout method by placing metallic nanoantennas onto the multiple focal spots of the fraxicon. Our study extends the versatile illumination capabilities of surface wave systems

Vlasov Description Of Dense Quark Matter

We discuss properties of quark matter at finite baryon densities and zero temperature in a Vlasov approach. We use a screened interquark Richardson's potential consistent with the indications of Lattice QCD calculations. We analyze the choices of the quark masses and the parameters entering the potential which reproduce the binding energy (B.E.) of infinite nuclear matter. There is a transition from nuclear to quark matter at densities 5 times above normal nuclear matter density. The transition could be revealed from the determination of the position of the shifted meson masses in dense baryonic matter. A scaling form of the meson masses in dense matter is given.Comment: 15 pages 4 figure

Anapole Moment and Other Constraints on the Strangeness Conserving Hadronic Weak Interaction

Standard analyses of low-energy NN and nuclear parity-violating observables have been based on a pi-, rho-, and omega-exchange model capable of describing all five independent s-p partial waves. Here a parallel analysis is performed for the one-body, exchange-current, and nuclear polarization contributions to the anapole moments of 133Cs and 205Tl. The resulting constraints are not consistent, though there remains some degree of uncertainty in the nuclear structure analysis of the atomic moments.Comment: Revtex, 10 pages, 1 figur

Towards targeted dietary support for shift workers with type 2 diabetes (Shift-Diabetes study): A mixed-methods case study protocol

BACKGROUND: Blood glucose is higher in people working night-shifts compared to day-workers. Changes to eating behaviour, activity, and sleep patterns in addition to circadian disruption are likely to impact glucose management in night-shift workers with Type 2 diabetes. AIM: To investigate current dietary intake and glucose variability during night work, including barriers and facilitators to dietary behavior in this context. METHODS: A mixed-methods case study will be conducted. Shift workers with Type 2 diabetes working in a hospital setting will be recruited to this two-part study. Part 1: 70 participants will complete a 10-day observational study collecting data on continuous glucose, diet (self-report diary), sleep and physical activity during a period covering night work, rest days and non-night workdays. Mean glucose concentration and variability, and the mean healthy diet index score, will be compared between days of night work, non-night work and rest, after adjusting for other individual factors (sleep/physical activity/demographics). Part 2: A sample (n~13) will complete semi-structured interviews based on behavioural science frameworks to explore barriers/enablers to dietary behaviour when working night shifts. This will inform a quantitative survey to explore the generalisability of interview findings. DISCUSSION: Findings from Part 1 and 2 will be triangulated to identify potential intervention strategies to address key barriers and enablers to healthier eating, and in turn improved glucose control, in shift workers with Type 2 diabetes. This will be facilitated through stakeholder consultation and application of behavioural science frameworks

Laparoscopic cytoreductive nephrectomy is associated with significantly improved survival compared with open cytoreductive nephrectomy or targeted therapy alone

The aim of the present study was to compare the survival outcomes for patients with metastatic renal cell carcinoma (mRCC) who underwent laparoscopic cytoreductive nephrectomy (CN) vs. open CN vs. targeted therapy (TT) alone at our institution. A retrospective chart review was performed at our institution for patients who underwent CN prior to TT (laparoscopic, n=48; open, n=48) or who were deemed unfit for surgery and received TT alone (n=36), between January 2007 and December 2012. Kaplan-Meier estimated survival and Cox proportional hazards analyses were performed. Laparoscopic CN was associated with significantly longer survival compared with open CN or TT alone (median survival 24 vs. \u3c12 months, respectively; P\u3c0.01). On multivariate analysis, laparoscopic CN was an independent predictor of survival [hazard ratio (HR)=0.48, P\u3c0.01), controlling for preoperative risk factors, while survival was similar between open CN and TT alone (HR=0.85, P=0.54). In our experience, laparoscopic CN appears to be a significant predictor of survival in mRCC. Selection bias of the surgeon for patients with improved survival may account for clinical variables that were otherwise difficult to quantify. For patients who were not candidates for laparoscopic CN, open CN did not confer a survival benefit over TT alone, while it was associated with increased morbidity

Visual Imagery and Self-Questioning: Strategies to Improve Comprehension of Written

This research was published by the KU Center for Research on Learning, formerly known as the University of Kansas Institute for Research in Learning Disabilities.Two learning strategies, visual imagery and-self-questioning, designed to increase reading comprehension were taught to six learning disabled students using a multiple-baseline across strategies design. Results of the study indicate that LD students can learn the two strategies and can apply them in both reading-ability level and grade-level materials. The students' use of the strategies resulted in greater comprehension scores from the pretest in baseline to the posttest after training. Instructional time for each strategy ranged from five to seven hours