Experimental Evaluation of Multi-scale Tactile Maps Created with SIM, a Web App for Indoor Map Authoring.

In this article, we introduce Semantic Interior Mapology (SIM), a web app that allows anyone to quickly trace the floor plan of a building, generating a vectorized representation that can be automatically converted into a tactile map at the desired scale. The design of SIM is informed by a focus group with seven blind participants. Maps generated by SIM at two different scales have been tested by a user study with 10 participants, who were asked to perform a number of tasks designed to ascertain the spatial knowledge acquired through map exploration. These tasks included cross-map pointing and path finding, and determination of turn direction/walker orientation during imagined path traversal. By and large, participants were able to successfully complete the tasks, suggesting that these types of maps could be useful for pre-journey spatial learning.

Numerical Optimization on Char Conversion and NOx Emission under Various Operating Conditions in a Retrofit Biomass Boiler.

Retrofitting retirement or existing fossil boiler with biomass is an important method of curbing electricity shortage and lowering the cost of modern power plants. However, the use of biomass combustion is hampered by operational problems, such as the resulting high unburned carbon, amount of bottom ash, and nitrogen oxide (NOx) release. In this study, we investigated the burning of pulverized biomass in a retrofitting boiler power plant using computational fluid dynamics of commercial software fluent ANSYS to determine the optimal combustion conditions. The objective of this study was to investigate a 125 MWe pulverized biomass boiler that was retrofitted from an anthracite down-fired boiler. The air distribution, including the influence of the secondary air ratio and the location of the burner standby, was evaluated. Key factors such as biomass ash mass at the hopper, char conversion, and high zone temperature relating to NOx formation/reduction were calculated. The adjustment of the secondary air ratio from 30 to 50% of the total air and the mass ash at the hopper significantly decreased to a low value at 247 kg/h and a high value of char conversion at 97.33% in case R (SA40%). The standard deviation temperature was 240 K at the BNR B-A level for case R, which was significantly lower than in other cases. This implies that the best mixing of air and biomass occurs in case R at 40%. Comparative analysis of the burner standby conditions showed that the NOx emission was similar at the boiler outlet (approximately 94-116 ppm). Burner A on standby, with a secondary air ratio of 40%, was used as the optimal case with the highest value of char conversion at 98.43%, the lowest bottom ash release of 204 kg/h, and a low-NOx emission of 106 ppm.

Comparative Study of the Synergistic Effects of Blending Raw/Torrefied Biomass and Vietnamese Anthracite Using Co-pyrolysis.

Biomass can be upgraded via torrefaction, and torrefied kenaf (TK) is a fuel that allows blending with coal at high ratios. In the present study, raw kenaf (Hibiscus cannabinus L.) (RK) was torrefied at 523 K for 30 min and then mixed with Vietnamese anthracite (NinhBinh, NB) before co-pyrolysis. Thermogravimetric (TG) analysis was used to evaluate the behavior of RK, TK, and blended RK/TK during co-pyrolysis at biomass blending ratios (BBRs) of 0, 25, 50, 75, and 100 wt %. The TG and derivative thermogravimetry curves of a mixture of NB and RK (NBRK) were similar to those of RK. The decomposition curves of a mixture of NB and TK (NBTK) depended on the mass fraction of TK. Based on weight loss differences between the experimental and calculated data for the fuel blends, no interaction between the RK and anthracite was observed for all BBRs, whereas anthracite involving 50 and 75% TK exhibited synergistic effects. The temperature range for synergy and degree of synergy for NB and TK depended on the heating rate and mass ratio of TK. Kinetic parameters were calculated using the Friedman-non-isothermal free kinetic method at heating rates of 10, 20, and 40 K/min. The results showed that the activation energy (E) values of the NBRK at conversion ratios of 0.2-0.5 were equal to those of the RK, whereas they were superior at NB decomposition ratios of 0.6-0.8. NBTK1-1 (BBR of 50%) showed E values higher than those of NB at some conversion ratios, thus demonstrating a negative impact of blending. Further, NBTK1-3 (BBR of 75%) and NBTK3-1 (BBR of 25%) exhibited E values between those of NB and TK. The present study suggests that a high TK mass fraction (75%) in the blend for co-pyrolysis is optimal for the activation energy and volatile matter yield.

Effect of Torrefaction on Thermal and Kinetic Behavior of Kenaf during Its Pyrolysis and CO2 Gasification.

Torrefaction is an appealing pretreatment method for improving the fuel properties of kenaf biomass before its utilization in thermochemical processes. This study evaluated and compared the impact of torrefaction on thermal behavior and kinetics during pyrolysis and gasification. Thermogravimetric analysis experiments were conducted at temperatures of 300-1173 K at several heating rates under N2 and CO2 atmospheres. The raw and torrefied kenaf (RK and TK) during CO2 gasification in the low-temperature region (<900 K) was found to exhibit a tendency that was similar to that of N2. However, TK during CO2 gasification resulted in a lower maximum mass loss rate, delayed initiating temperature, and lower devolatilization index due to lower reactivity. In addition, the gasification reaction of CO2 and char was observed to occur in the high-temperature region (> 900 K), thus improving conversion efficiencies. The activation energy for TK in a CO2 atmosphere depending on the conversion was calculated using the distributed activation energy method. The activation of RK during CO2 gasification was higher than that of N2. However, TK during CO2 gasification exhibited a lower activation energy compared to that of N2, indicating its potential as a better feedstock during the CO2 gasification process and the ability to save energy.

A Multi-scale Embossed Map Authoring Tool for Indoor Environments.

We introduce a multi-scale embossed map authoring tool (M-EMAT) that produces tactile maps of indoor environments from the building's structural layout and its 3D-scanned interiors on demand. Our tool renders indoor tactile maps at different spatial scales, representing a building's structure, a zoomed-in of a specific area, or an interior of a room. M-EMAT is very easy to use and produces accurate results even in the case of complex building layouts.

Competition or cooperation in transboundary fish stocks management: Insight from a dynamical model.

An idealized system of a shared fish stock associated with different exclusive economic zones (EEZ) is modelled. Parameters were estimated for the case of the small pelagic fisheries shared between Southern Morocco, Mauritania and the Senegambia. Two models of fishing effort distribution were explored. The first one considers independent national fisheries in each EEZ, with a cost per unit of fishing effort that depends on local fishery policy. The second one considers the case of a fully cooperative fishery performed by an international fleet freely moving across the borders. Both models are based on a set of six ordinary differential equations describing the time evolution of the fish biomass and the fishing effort. We take advantage of the two time scales to obtain a reduced model governing the total fish biomass of the system and fishing efforts in each zone. At the fast equilibrium, the fish distribution follows the ideal free distribution according to the carrying capacity in each area. Different equilibria can be reached according to management choices. When fishing fleets are independent and national fishery policies are not harmonized, in the general case, competition leads after a few decades to a scenario where only one fishery remains sustainable. In the case of sub-regional agreement acting on the adjustment of cost per unit of fishing effort in each EEZ, we found that a large number of equilibria exists. In this last case the initial distribution of fishing effort strongly impact the optimal equilibrium that can be reached. Lastly, the country with the highest carrying capacity density may get less landings when collaborating with other countries than if it minimises its fishing costs. The second fully cooperative model shows that a single international fishing fleet moving freely in the fishing areas leads to a sustainable equilibrium. Such findings should foster regional fisheries organizations to get potential new ways for neighbouring fish stock management.

Multidimensional Hybridization of Dark Surface Plasmons.

Synthetic three-dimensional (3D) nanoarchitectures are providing more control over light-matter interactions and rapidly progressing photonic-based technology. These applications often utilize the strong synergy between electromagnetic fields and surface plasmons (SPs) in metallic nanostructures. However, many of the SP interactions hosted by complex 3D nanostructures are poorly understood because they involve dark hybridized states that are typically undetectable with far-field optical spectroscopy. Here, we use experimental and theoretical electron energy loss spectroscopy to elucidate dark SPs and their interactions in layered metal-insulator-metal disc nanostructures. We go beyond the established dipole SP hybridization analysis by measuring breathing and multipolar SP hybridization. In addition, we reveal multidimensional SP hybridization that simultaneously utilizes in-plane and out-of-plane SP coupling. Near-field classic electrodynamics calculations provide excellent agreement with all experiments. These results advance the fundamental understanding of SP hybridization in 3D nanostructures and provide avenues to further tune the interaction between electromagnetic fields and matter.

Enhancement of clavulanic acid by replicative and integrative expression of ccaR and cas2 in Streptomyces clavuligerus NRRL3585.

Clavulanic acid (CA) is an inhibitor of beta-lactamase that is produced from Streptomyces clavuligerus NRRL3585 and is used in combination with other antibiotics in clinical treatments. In order to increase the production of CA, the replicative and integrative expressions of ccaR (encoding for a specific regulator of the CA biosynthetic operon) and cas2 (encoding for the rate-limiting enzyme in the CA biosynthetic pathway) were applied. Six recombinant plasmids were designed for this study. The pIBRHL1, pIBRHL3, and pIBRHL13 were constructed for overexpression, whereas pNQ3, pNQ2, and pNQ1 were constructed for chromosomal integration with ccaR, cas2, and ccaR-cas2, respectively. All of these plasmids were transformed into S. clavuligerus NRRL3585. CA production in transformants resulted in a significantly enhanced amount greater than that of the wild type, a 2.25-fold increase with pIBRHL1, a 9.28-fold increase with pNQ3, a 5.06-fold increase with pIBRHL3, a 2.93-fold increase with pNQ2 integration, a 5.79-fold increase with pIBRHL13, and a 23.8-fold increase with pNQ1. The integrative pNQ1 strain has been successfully applied to enhance production.

Characterization of pbpA and pbp2 encoding penicillin-binding proteins located on the downstream of clavulanic acid gene cluster in Streptomyces clavuligerus.

Two genes, pbpA (orf18) and pbp2 (orf19) located on the downstream of clavulanic acid (CA) gene cluster of Streptomyces clavuligerus were cloned into pET-28a(+), and confirmed to encode a family of high molecular-weight penicillin-binding proteins (PBPs). Both genes were amplified from genomic DNA by PCR and expressed in E. coli BL21 (DE3). Hydropathy plots of the proteins revealed a single stretch of hydrophobic amino acids indicating them to be transmembrane proteins. Pbp2 had lower affinity to penicillin G compared to PbpA, and was essential to the cell growth in contrast to PbpA.