Voltage cycling process for the electroconversion of biomass-derived polyols

Electrification of chemical reactions is crucial to fundamentally transform our society that is still heavily dependent on fossil resources and unsustainable practices. In addition, electrochemistry-based approaches offer a unique way of catalyzing reactions by the fast and continuous alteration of applied potentials, unlike traditional thermal processes. Here, we show how the continuous cyclic application of electrode potential allows Pt nanoparticles to electrooxidize biomass-derived polyols with turnover frequency improved by orders of magnitude compared with the usual rates at fixed potential conditions. Moreover, secondary alcohol oxidation is enhanced, with a ketoses-to-aldoses ratio increased up to sixfold. The idea has been translated into the construction of a symmetric single-compartment system in a two-electrode configuration. Its operation via voltage cycling demonstrates high-rate sorbitol electrolysis with the formation of H2 as a desired coproduct at operating voltages below 1.4 V. The devised method presents a potential approach to using renewable electricity to drive chemical processes.

Two Types of Four-Compartment Tefillin Cases from the Judean Desert Caves

Approximately thirty tefillin cases were discovered in the Judean Desert. The publishers of these finds distinguished between single-compartment cases, which they identified as “arm-tefillin,” and four-compartment cases, which they identified as “head-tefillin.” Here I present a further typological distinction between two subtypes among the four-compartment tefillin cases: (1) the “simple-type,” in which a single line of stitching separates the compartments from one another, and (2) the “split-type,” in which the compartments are separated by incisions in the leather and each compartment is stitched closed individually. It seems likely that some kind of ritual issue is at stake, and an allusion to these two types as competing halakhic practices may be found in the tannaitic literature—with the rabbis ultimately rejecting the “split-type.” The Judean Desert finds may represent a synchronic debate between competing groups, a diachronic development, or perhaps practices followed contemporaneously by members of one and the same group.

Bioaccumulation of Zn and 137Cs in Glauconomya virens (Linnaeus, 176) Upon Exposure to Sigle and Mixture of Zn or 137Cs and Salinity

This study aims to determine the effect of concentrations and salinity of seawater on the bioaccumulation of zinc and cesium in the Glauconomya virens. Salinity conditions and contaminant concentrations in the marine environment can change due to weather and other inputs. A biokinetic experiment was carried out using a single compartment approach that used radiotracer 65Zn and 137Cs. The experiments conducted were biota collection, acclimatization, bioaccumulation, and elimination. Acclimatization aims for the adaptation of biota in an experimental environment. Bioaccumulation was by placing the biota in an aquarium containing seawater media spiked by 65Zn, Zn, and 137Cs radiotracer contaminants. The elimination process was the release of contaminants from the body of the biota by placing them in clean and flowing seawater. The experimental results show that the uptake and elimination of Zn and Cs were influenced by these two parameters (water concentration and salinity). The highest value of Concentration Factor (CF) for Zn was 11.14 ml.g-1 under influences its concentration of 0.7 ppm in water. In the depuration process, Zn maintained by G virens were 39.44; 31.17; 23.62; and 23.92% after these organisms accumulate this element from seawater containing 0.1; 0.3, 0.5, and 0.7 ppm, respectively. The highest of 137Cs under influences its concentration of 3 Bg.ml-1 reached 2.65 mL.g-1. The effect of salinity is directly proportional to the factor value of Zn and 137Cs concentration.

Mathematical modeling of the effects of Wnt-10b on bone metabolism

Bone health is determined by many factors including bone metabolism or remodeling. Wnt-10b has been shown to alter osteoblastogenesis through pre-osteoblast proliferation and differentiation as well as the osteoblast apoptosis rate, which collectively lead to the increase of bone density. To model this change, we adapted a previously published model of bone remodeling. The resulting model is a single compartment system that includes ordinary differential equations for active osteoclasts, pre-osteoblasts, osteoblasts, and osteocytes and a differential equation that tracks the amount of bone present at the remodeling site. Our alterations to the original model consist of extending it past a single remodeling cycle and implementing a direct relationship to Wnt-10b. Four new parameters were estimated and validated using normalized data from mice. The model connects Wnt-10b to bone metabolism and predicts the change in bone volume caused by a change in Wnt-10b. We find that this model predicts the expected increase in pre-osteoblasts and osteoblasts while also pointing to a decrease in osteoclasts when Wnt-10b is increased.

Genetic Algorithm for the Pick-up and Delivery Problem with Time Window by Multi-Compartment Vehicles

In this article we focus on multi-compartment vehicles that have to pick-up goods from suppliers and deliver them to various customers. Usually these goods cannot be transported by single-compartment vehicles due to the fact that some products are harmful to others: incompatibility between products. It is therefore a question of satisfying a set of customers while respecting the constraints linked to the capacity of each vehicle compartment, each type of product and ensuring that each supplier is visited before his customer. Our work consists firstly of mathematically modelling the problem described and secondly of solving it using methods due to its complexity. In this case we use the genetic algorithm to solve the pick-up and delivery problem of goods with a time window provided by multi-compartment vehicles. Our model allows to find a minimum distance and a minimum cost in the tour carried out by a reasonable number of vehicles.

From Biophysical to Integrate-and-Fire Modeling

This article proposes a methodology to extract a low-dimensional integrate-and-fire model from an arbitrarily detailed single-compartment biophysical model. The method aims at relating the modulation of maximal conductance parameters in the biophysical model to the modulation of parameters in the proposed integrate-and-fire model. The approach is illustrated on two well-documented examples of cellular neuromodulation: the transition between type I and type II excitability and the transition between spiking and bursting.