Enhancing photocatalytic degradation of the cyanotoxin microcystin-LR with the addition of sulfate-radical generating oxidants.

This study investigated the coupling of sulfate radical generating oxidants, (persulfate, PS and peroxymonosulfate, PMS) with TiO2 photocatalysis for the degradation of microcystin-LR (MC-LR). Treatment efficiency was evaluated by estimating the electrical energy per order (EEO). Oxidant addition at 10 mg/L reduced the energy requirements of the treatment by 60% and 12% for PMS and PS, respectively compared with conventional photocatalysis. Quenching studies indicated that both sulfate and hydroxyl radicals contributed towards the degradation of MC-LR for both oxidants, while Electron Paramagnetic Resonance (EPR) studies confirmed that the oxidants prolonged that lifetime of both radicals (concentration maxima shifted from 10 to 20min), allowing for bulk diffusion and enhancing cyanotoxin removal. Structural identification of transformation products (TPs) formed during all treatments, indicated that early stage degradation of MC-LR occurred mainly on the aromatic ring and conjugated carbon double bonds of the ADDA amino acid. In addition, simultaneous hydroxyl substitution of the aromatic ring and the conjugated double carbon bonds of ADDA (m/z= 1027.5) are reported for the first time. Oxidant addition also increased the rates of formation/degradation of TPs and affected the overall toxicity of the treated samples. The detoxification and degradation order of the treatments was UVA/TiO2/PMS > UVA/TiO2/PS>> UVA/TiO2

Effects of Acetate on Cation Exchange Capacity of a Zn-Containing Montmorillonite:Physicochemical Significance and Metal Uptake

Fundamental properties such as cation exchange capacity (CEC), permanent charge, pH(PZC), and metal uptake of a Zn-containing montmorillonite are modified, in a predictable manner, by a mild chemical treatment using acetate. Acetate treatment allows a controllable increase of the CEC of montmorillonite up to 180 mequiv/100 g. The CEC of the clay is increasing for decreasing Zn content, with a slope of Delta[Zn/Delta[CEC] approximate to -2. X-ray powder diffraction analysis shows that the lamellar structure of the clay remains unaltered by the acetate treatment, while XPS substantiates the removal of Zn. H(+) uptake data show that the intrinsic protonation pK values and concentration of the variable charge sites ( SOH) are not modified by the acetate treatment. In contrast, the concentration of the permanent charge sites ( X(-)) increased linearly with Zn removal by acetate, leading to a significant H(+) and Cd(2+) uptake enhancement. A physical model is suggested where acetate removes Zn ions strongly bound in the clay, and this in turn modulates the permanent charge and the CEC of the clay

Coping with floods: impacts, preparedness and resilience capacity of Greek micro-, small- and medium-sized enterprises in flood-affected areas

Purpose: This paper aims to investigate aspects of flood experience, attitudes and responses of micro-, small- and medium-sized enterprises (MSMEs) in Greece and to indicate a typology of strategies associated with their relative effort to build flood resilience capacity. Design/methodology/approach: A qualitative study protocol was used, based on pertinent literature that considers how business entities withstand, adapt and/or recover from non-linear climate change impacts, natural hazards and extreme weather. Data was obtained by conducting semi-structured interviews with 82 MSMEs’ owners-managers who had recently experienced flooding. Findings: The study reports limited activities of MSMEs towards flood resilience capacity despite the threat of relevant disasters. Findings suggest that most owners-managers of these enterprises are not adequately preparing their businesses for the impacts of flooding. Research limitations/implications: The findings call for multi-level and dynamic perspectives to be examined in assessing MSME resilience capacity to floods. It is attitudinal, managerial, organisational, behavioural and regulatory (as well as other institutional) factors that merit further investigation. Such an investigation would allow a better understanding as to whether these factors hinder or enable conditions for microeconomic flood preparedness and resilience as well as how they may interact with each other or create feedback loops. Practical implications: The study carries managerial implications and policy recommendations in terms of nurturing opportunities towards awareness-raising campaigns for reducing deficits in managerial knowledge and competencies. It also encapsulates practical implications in terms of emphasising supporting mechanisms from key institutional stakeholders to allow MSMEs scan available options they have in effectively reinforcing the business premises from the forces of rising waters. Originality/value: Most of the related studies have examined flood impacts, responses and/or resilience capacity at the household- or community-level. Empirical work that is conducted to ascertain how MSMEs cope with flooding remains thin on the ground. In response to this, the current study and the typology of MSMEs’ strategic postures that are suggested seek to contribute to this under-researched topic

Pythagoras project: Development of an innovative training package on Indoor Environment Quality

The aim of the Pythagoras project is the development and assessment of Greek national training material in the sector of indoor environmental quality. The need for education in this specific sector is dictated by the significant indoor environment deterioration and associated health hazards, which are caused by low ventilation levels, combined with the use of many modern building materials that aggravate pollutants emissions. Early in the project, a review is undertaken of the international literature and the syllabuses of foreign research and educational institutions active in indoor environment quality issues. At the same time, the requirements of the Greek educational and broader society, related to issues of indoor pollution and health, are determined. A training methodology is consequently developed, with the objective to optimally cover all the parameters associated with the indoor environment quality, for trainees of various disciplines. The training material is produced both in printed (book) and integrated electronic (e-learning) format. Additionally, four seminars are organized covering the respective sections of the training package. The training package is being assessed both by the trainees but also by international experts in the sector of indoor environment quality

Super-heavy fermion material as metallic refrigerant for adiabatic demagnetization cooling

Low-temperature refrigeration is of crucial importance in fundamental research of condensed matter physics, as the investigations of fascinating quantum phenomena, such as superconductivity, superfluidity and quantum criticality, often require refrigeration down to very low temperatures. Currently, cryogenic refrigerators with $^3$He gas are widely used for cooling below 1 Kelvin. However, usage of the gas is being increasingly difficult due to the current world-wide shortage. Therefore, it is important to consider alternative methods of refrigeration. Here, we show that a new type of refrigerant, super-heavy electron metal, YbCo$_2$Zn$_{20}$, can be used for adiabatic demagnetization refrigeration, which does not require 3He gas. A number of advantages includes much better metallic thermal conductivity compared to the conventional insulating refrigerants. We also demonstrate that the cooling performance is optimized in Yb$_{1-x}$Sc$_x$Co$_2$Zn$_{20}$ by partial Sc substitution with $x\sim$0.19. The substitution induces chemical pressure which drives the materials close to a zero-field quantum critical point. This leads to an additional enhancement of the magnetocaloric effect in low fields and low temperatures enabling final temperatures well below 100 mK. Such performance has up to now been restricted to insulators. Since nearly a century the same principle of using local magnetic moments has been applied for adiabatic demagnetization cooling. This study opens new possibilities of using itinerant magnetic moments for the cryogen-free refrigeration

Last Men Standing: Chlamydatus Portraits and Public Life in Late Antique Corinth

Notable among the marble sculptures excavated at Corinth are seven portraits of men wearing the long chlamys of Late Antique imperial office. This unusual costume, contemporary portrait heads, and inscribed statue bases all help confirm that new public statuary was created and erected at Corinth during the 4th and 5th centuries. These chlamydatus portraits, published together here for the first time, are likely to represent the Governor of Achaia in his capital city, in the company of local benefactors. Among the last works of the ancient sculptural tradition, they form a valuable source of information on public life in Late Antique Corinth

Alzheimer's Aβ Peptides with Disease-Associated N-Terminal Modifications: Influence of Isomerisation, Truncation and Mutation on Cu2+ Coordination

coordination of various Aβ peptides has been widely studied. A number of disease-associated modifications involving the first 3 residues are known, including isomerisation, mutation, truncation and cyclisation, but are yet to be characterised in detail. In particular, Aβ in plaques contain a significant amount of truncated pyroglutamate species, which appear to correlate with disease progression. coordination modes between pH 6–9 with nominally the same first coordination sphere, but with a dramatically different pH dependence arising from differences in H-bonding interactions at the N-terminus. coordination of Aβ, which may be critical for alterations in aggregation propensity, redox-activity, resistance to degradation and the generation of the Aβ3–× (× = 40/42) precursor of disease-associated Aβ3[pE]–x species

Eutrophication control using a novel bentonite humic-acid composite material Bephos™

The main objective of the present study was to estimate the efficiency of Bephos™ as an active capping agent preventing the phosphate release from eutrophic lake sediments. Bephos™ was compared with unmodified bentonite (N-bentonite) and natural zeolite (N-zeolite), in a ratio 1/10/10 respectively. Bephos™ as a P-inactivation agent resulted in about ∼96.6% reduction of the phosphate flux and ∼75.2% reduction of the ammonium flux from the sediments respectively. N-Zeolite and N-bentonite as capping materials resulted in about 64% and 91.8% reduction of the phosphorus flux and in about 70% and 35.6% reduction of the ammonium flux from the sediments respectively. Moreover, an additional purpose of this study was to investigate the different P-forms present in sediments, their contributions to the P-loadings of the ecosystem and also the effect of Bephos™ amendment on P-binding properties of sediments. The results show that Bephos™ restrained P release from the sediments, reducing the proportion of P-mobile in sediments, which was transformed into non-reactive species. The application of Bephos™ caused an increase in the mass of P present in the more refractory 'apatite bound P' fraction compared to P-mobile, and also more P was stored in the residual P fraction of sediment post-application

A novel bentonite-humic acid composite material Bephos™ for removal of phosphate and ammonium from eutrophic waters

A novel low-cost composite material was prepared (Bephos™) by embedding Fe, Cu ions and humic acid using in the interlayer space of a natural bentonite. Bench-scale batch experiments were performed to examine its efficiency as adsorbent for phosphate and ammonium removal from natural waters. Phosphate and ammonium uptake was evaluated vs. pH in adsorption kinetics and adsorption isotherms. The effect of salinity (fresh, brackish and marine waters) and adsorption thermodynamics were also investigated. Bephos™ exhibits higher adsorption than other pertinent materials. Moreover Bephos™ is cable for simultaneous adsorption of both phosphorus and ammonia and this is an important advantage against other materials used to restore eutrophic water bodies. The maximum phosphate and ammonium adsorption capacities were 26.5. mg/g and 202.1. mg/g respectively. Bephos™ can function efficiently within a wide range of pH, e.g. 5-9. Adsorption kinetics showed that more than 90% and 70% removal of phosphate and ammonium respectively from water within 30. min. Bephos™ is potent for remediation of phosphate and ammonium at low concentrations that occur in natural water ecosystems. © 2013 Elsevier B.V