Heterogeneous photocatalytic removal of toluene from air on building materials enriched with TiO2

This paper reports the potential of heterogeneous photocatalysis as an advanced oxidation technology for removal of toluene from air using TiO₂ as a photocatalyst in building materials. First, the photocatalytic activity of two types of TiO₂ containing building materials, i.e. roofing tiles and corrugated sheets, has been investigated at ambient conditions (T=25.0 °C; relative humidity RH=47%; toluene inlet concentration [TOL]_in=17–35 ppbv). Toluene removal efficiencies up to 63% were observed at a gas residence time (τ) of 17 s. Second, the effect of RH (1–77%), [TOL]_in (23–465 ppmv) and τ (17–115 s) on toluene removal has been systematically investigated using TiO₂ containing roofing tiles as photocatalytic building materials. Results revealed lower toluene removal efficiencies at higher RH and [TOL]_in, whereas a positive effect was observed with increased τ. Under optimal conditions, toluene removal efficiencies up to 78±2% and elimination rates higher than 100 mg h⁻¹ m⁻² roofing tile were obtained. A decline in photocatalytic activity by a factor of 2 was observed after operation at gas residence times shorter than 69 s and [TOL]_in higher than 76 ppmv. Washing the building materials with deionized water, simulating rainfall, could partially (i.e. by a factor 1.3) regenerate the catalyst activity.     

Transparent exopolymer particle removal in different drinking water production centers

Transparent exopolymer particles (TEP) have recently gained interest in relation to membrane fouling. These sticky, gel-like particles consist of acidic polysaccharides excreted by bacteria and algae. The concentrations, expressed as xanthan gum equivalents L⁻¹ (μg X_eq L⁻¹), usually reach hundred up to thousands μg X_eq L⁻¹ in natural waters. However, very few research was performed on the occurrence and fate of TEP in drinking water, this far. This study examined three different drinking water production centers, taking in effluent of a sewage treatment plant (STP), surface water and groundwater, respectively. Each treatment step was evaluated on TEP removal and on 13 other chemical and biological parameters. An assessment on TEP removal efficiency of a diverse range of water treatment methods and on correlations between TEP and other parameters was performed. Significant correlations between particulate TEP (>0.4 μm) and viable cell concentrations were found, as well as between colloidal TEP (0.05-0.4 μm) and total COD, TOC, total cell or viable cell concentrations. TEP concentrations were very dependent on the raw water source; no TEP was detected in groundwater but the STP effluent contained 1572 μg X_eq L⁻¹ and the surface water 699 μg X_eq L⁻¹. Over 94% of total TEP in both plants was colloidal TEP, a fraction neglected in nearly every other TEP study. The combination of coagulation and sand filtration was effective to decrease the TEP levels by 67%, while the combination of ultrafiltration and reverse osmosis provided a total TEP removal. Finally, in none of the installations TEP reached the final drinking water distribution system at significant concentrations. Overall, this study described the presence and removal of TEP in drinking water systems.     

The Effect of Housing Expenses and Subsidies on the Income Distribution in Flanders and the Netherlands

This study explores the role of housing expenses and subsidies with respect to income distribution in Flanders (the northern part of Belgium) and the Netherlands in 2005–2006. It analyses income poverty and inequality by comparing equivalent disposable income before and after housing expenses with a relative poverty threshold and the Gini coefficient. Poverty and income inequality increase in both ‘countries’ when equivalent disposable income is corrected for housing expenses. Furthermore, the relative position of outright owners and social tenants regarding poverty improves. Housing subsidies play a (partly) different role in Flanders and the Netherlands. The implicit social rent subsidy in Flanders and the explicit housing allowance in the Netherlands serve the same goal; however, they both redistribute income relatively strongly in favour of low-income tenants. The tax relief system on the other hand increases income inequality in society, in both Flanders and the Netherlands, whereas our comparative analysis suggests that tax relief does not have a moderating effect on net housing expenses.     

Zwitterionic‐Coated “Stealth” Nanoparticles for Biomedical Applications: Recent Advances in Countering Biomolecular Corona Formation and Uptake by the Mononuclear Phagocyte System

Nanoparticles represent highly promising platforms for the development of imaging and therapeutic agents, including those that can either be detected via more than one imaging technique (multi‐modal imaging agents) or used for both diagnosis and therapy (theranostics). A major obstacle to their medical application and translation to the clinic, however, is the fact that many accumulate in the liver and spleen as a result of opsonization and scavenging by the mononuclear phagocyte system. This focused review summarizes recent efforts to develop zwitterionic‐coatings to counter this issue and render nanoparticles more biocompatible. Such coatings have been found to greatly reduce the rate and/or extent of non‐specific adsorption of proteins and lipids to the nanoparticle surface, thereby inhibiting production of the “biomolecular corona” that is proposed to be a universal feature of nanoparticles within a biological environment. Additionally, in vivo studies have demonstrated that larger‐sized nanoparticles with a zwitterionic coating have extended circulatory lifetimes, while those with hydrodynamic diameters of ≤5 nm exhibit small‐molecule‐like pharmacokinetics, remaining sufficiently small to pass through the fenestrae and slit pores during glomerular filtration within the kidneys, and enabling efficient excretion via the urine. The larger particles represent ideal candidates for use as blood pool imaging agents, whilst the small ones provide a highly promising platform for the future development of theranostics with reduced side effect profiles and superior dose delivery and image contrast capabilities.     

Deriving linear size relations for logic programs by abstract interpretation

We propose an automatic method for derivinglinear size relations, which specify, with respect to some given norm, linear relationships between the sizes of the arguments of atoms in the least Herbrand model of a definite Horn clause program. The method is presented as an application of abstract interpretation. Its abstract domain consists of affine subspaces or linear varieties, and operations on elements of the domain are expressed in terms of operations from linear algebra. The main application of the technique is situated in automatic termination analysis. Others are complexity and granularity analysis and the specialisation of constraints in constraint logic languages.     

Kinetic study of the initiation reaction by a dilithium initiator used for the preparation of ABA triblock copolymers in non-polar medium

The kinetics of the reaction of the bifunctional lithium initiator, Li-DIB-Li, with DPE was studied. It was shown that the kinetic order of this reaction with respect to the reactive ends of the dilithium initiator is close to zero, indicating a rather high degree of aggregation of the dilithium initiator. Possible structures of these highly aggregated species are illustrated by DFT quantum-chemical calculations and their relative stabilities are analyzed. It is concluded that the solubilization through breaking up of long intermolecular aggregates of dilithium initiator chains into small soluble ones by complexation with durene is certainly as important or more than the dissociation of the active centers of the dilithium initiator, as originally thought.     

Microwave‐Assisted Synthesis of Pyrazino[2,1‐b]quinazolines and 3‐Indolyl‐2(1H)‐pyrazinones Employing a Chemoselective Silver(I)‐ and Gold(I)‐Catalyzed Reaction

Novel microwave‐assisted syntheses of pyrazino[2,1‐b]quinazolines and 3‐indolyl‐2(1H)‐pyrazinones employing silver(I)‐ or gold(I)‐catalyzed protocols have been elaborated. The scope and limitations of these processes have been investigated.     

The ARTEMIS under‐ice AUV docking system

The ARTEMIS docking system demonstrates autonomous docking capability applicable to robotic exploration of sub‐ice oceans and sub‐glacial lakes on planetary bodies, as well as here on Earth. In these applications, melted or drilled vertical access shafts restrict vehicle geometry as well as the in‐water infrastructure that may be deployed. The ability of the vehicle to return reliably and precisely to the access point is critical for data return, battery charging, and/or vehicle recovery. This paper presents the mechanical, sensor, and software components that make up the ARTEMIS docking system, as well as results from field deployment of the system to McMurdo Sound, Antarctica in the austral spring of 2015. The mechanical design of the system allows the vehicle to approach the dock from any direction and to pitch up after docking for recovery through a vertical access shaft. It uses only a small volume of in‐water equipment and may be deployed through a narrow vertical access shaft. The software of the system reduces position estimation error with a hierarchical combination of dead reckoning, acoustic aiding, and machine vision. The system provides critical operational robustness, enabling the vehicle to return autonomously and precisely to the access shaft and latch to the dock with no operator input.     

Evaluation of biological activities of triterpenoid saponins from Maesa lanceolata

PURPOSE: This article presents a review that used three ADA studies on the distribution of dentists to determine whether the number of private practice prosthodontists in the mid 1990s has kept pace with the population in the various regions and states. RESULTS: Findings indicate that between 1987 and 1991 there was a marked national increase in numbers of prosthodontists followed by a marked decrease during the first half of the 1990s. There continued to be major differences, however, in practitioner-to-population ratios in different geographic areas. Since the mid 1980s, there has been a general increase in the number of graduates from prosthetic programs, but an increasing percentage of these graduates were foreign trained dentists. CONCLUSION: There continues to be a need to determine the adequacy of the number and distribution of prosthodontists.     

Biological Cover Mitigates Disruption of the Dermal Structure in Mechanically Expanded Skin in a Porcine Model

Tissue expansion is an integral procedure of the vast majority of breast reconstruction and has a significant impact on the final clinical outcomes. Therefore, technological advances leading to a fewer number of unfavorable outcomes and a decrease in complication rates are imperative. In this study, using a porcine model, we investigated an effect of acellular dermal matrix (ADM) used as a tissue expander cover on the dermal changes induced by mechanical forces during tissue expansion. After 14 days of expansion, skin samples were collected from one animal, while the second animal underwent radiation, and tissue was collected 8 weeks later. Tissue expanded without the use of ADM and unexpanded skin served as the controls. Collected skin biopsies were used for histological and immunohistochemical evaluation, and for gene expression analysis. We revealed that the biological cover incorporation into host tissue is facilitated by macrophages without inducing a broad inflammatory response. The utilization of ADM mitigated disruption in the dermal structure, excessive collagen deposition, and capsule formation in non-irradiated expanded skin. The protective effect was not fully maintained in irradiated skin. These results demonstrate that tissue expansion might be improved by using the tissue expander cover.