TESS. La banca dati on-line dei rivestimenti a mosaico

A project undertaken by the University of Padua has developed the new database system TESS for mosaics. This database system meets the national standards required by the Istituto Centrale per il Catalogo e la Documentazione – ICCD. The database is available on-line thanks to the project «Cultural heritage in the Adriatic area: knowledge, preservation and enhancement», co-financed by the Community Initiative INTERREG III A – Adriatic Cross Border Programme. In detail, the database TESS includes informative files regarding Building and Rooms, Location, relevant Bibliography and Mosaic Pavement. Each file contains plans, designs and photographs. Furthermore, all the fields have a list of univocal and exhaustive terms in the Italian language. The mosaics database aims to provide a key working tool for the identification of the origins of iconographic themes, their geographic distribution and the development of local fashions which vary according to the context. The software was developed on a FileMaker client/server environment to achieve these key goals: multiplatform availability (Windows/Macintosh), multiuser capability and remote connectivity. Making wide use of the latest tools included in FileMaker 8, the development group created a smart and complete GUI to access the complex data structure, and at the same time implemented a stringent control of user privileges by setting data-related group policies. The result is a powerful middleware application that allows data entry, analysis and publication to geographically distributed operators and will provide data consultation to other users through normal web browsers

A review on the efficient catalysts for algae transesterification to biodiesel

The depletion of fossil fuel resources and increasing environmental pollution led to a trend for using alternative, clean, green, and sustainable fuel and energy resources. To attain this aim, using biomass as an alternative resource for diesel production has been a hotspot among researchers. Biodiesel has several advantages, such as being lower toxic and more renewable, and eco-friendlier than diesel from fossil fuel resources. Several edible and non-edible bio-sources were used for the production of biodiesel from the transesterification process. Algal oil as a non-edible source is considered an abundant, low cost and green substrate for biodiesel production. Various factors such as reaction conditions and the type of catalyst affect the biodiesel production process. Different catalytic systems such as basic and acidic homogeneous and heterogeneous catalysts and biocatalysts were introduced for the process in the literature, and each proposed catalyst has its own advantages and disadvantages. For instance, in spite of the lower cost and better mass transfer of base and acid homogeneous catalysts, reaction system corrosion, non-reusability, and soap formation are serious challenges of these catalysts at an industrial scale. On the other hand, acid and base heterogenous catalysts overcame the issues of corrosion and recovery, but some matters such as mass transfer limitation, high cost, and weak performance in catalyzing both esterification of FFAs and transesterification of lipids must be taken into account. In addition, bio-catalysis as a high-cost process led to a purer product formation with less side reaction. Therefore, several significant factors should be considered for transesterification catalysts such as availability, cost, reusability, stability, mass transfer, and the possibility to manage both the transesterification of triglycerides and the esterification of FFAs, selecting a catalyst with predominant pros is viable. Here, a review of the biodiesel production from algal biomass focusing on the efficient catalyst of the process is presented

Catalytic Production of Levulinic Acid (LA) from Actual Biomass

Catalytic conversion of actual biomass to valuable chemicals is a crucial issue in green chemistry. This review discusses on the recent approach in the levulinic acid (LA) formation from three prominent generations of biomasses. Our paper highlights the impact of the nature of different types of biomass and their complex structure and impurities, different groups of catalyst, solvents, and reaction system, and condition and all related pros and cons for this process

Robust area coverage with connectivity maintenance

Robot swarms herald the ability to solve complex tasks using a large collection of simple devices. However, engineering a robotic swarm is far from trivial, with a major hurdle being the definition of the control laws leading to the desired globally coordinated behavior. Communication is a key element for coordination and it is considered one of the current most important challenges for swarm robotics. In this paper, we study the problem of maintaining robust swarm connectivity while performing a coverage task based on the Voronoi tessellation of an area of interest. We implement our methodology in a team of eight Khepera IV robots. With the assumptions that robots have a limited sensing and communication range - and cannot rely on centralized processing - we propose a tri-objective control law that outperforms other simpler strategies (e.g. a potential-based coverage) in terms of network connectivity, robustness to failure, and area coverage

Activated biochars as sustainable and effective supports for hydrogenations

Activated biochars were obtained from pyrolysis and CO2-physical activation of four different biomasses including tannery shaving waste (T), vine wood waste (W), barley waste (B) and Sargassum, brown macroalgae of Venice lagoon (A). The potential of obtained carbonaceous materials as the supports of Ni,Al catalysts was investigated in levulinic acid (LA) conversion to γ-valerolactone (GVL) as a model hydrogenation reaction. Al-containing species as the Lewis acid sites for the dehydration step were incorporated to the supports using wet impregnation or precipitation. Ni as a hydrogenation active phase was added to the supports via wet impregnation. Biochar-based supports and catalysts were characterized by AAS, elemental analysis, FTIR, N2 physisorption, XRD, SEM, EDS, TEM, He-TPD, NH3-TPD and TPR techniques. The catalysts were tested for LA hydrogenation to GVL in a batch system and aqueous medium. The results showed that Ni supported on activated biochar was not active due to a lack of Lewis acid sites for dehydration. Precipitated Al-containing species on the biochar-based supports demonstrated a better catalytic performance in the reaction compared to impregnated one because of different interactions with the support and Ni species. Among different supports, the activated biochars obtained from T and W acted as the best ones. A higher catalytic efficiency was strongly influenced by the chemical (aromaticity and stability, presence of N,O-doped and functional groups), textural (the porous texture and surface area), and morphological (higher dispersion of active phases) properties of activated biochars obtained from different biomasses with different natures

From seaweeds to cosmeceutics: A multidisciplinar approach

Macroalgae are widespread on the coasts of all the globe and lead to a negative ecological impact, requiring expensive remediations. Therefore, the valorization of invasive seaweed as a renewable source of bioactive products could represent a valid solution. In this context, three algal biomasses, belonging to brown, green, and red families (Sargassum muticum, Ulva lactuca, Solieria filiformis), collected in the venetian Laguna, were investigated as a source of active compounds for the formulation of cosmeceutics. Microwave (MW) and ultrasound (US) were applied to enhance the algae extraction by means of a hydroalcoholic solution. According to total phenolic content (TPC) evaluation, MW demonstrated the best performing outcomes, resulting in 19.77, 22.02, and 16.94 mgGAE/gExtr (30 min at 90◦C) for brown, green, and red algae, respectively. Antioxidant activity was tested as well, showing comparable trends (49.19, 26.24, and 3.02 mmolTrolox eq./gExtr for brown, green, and red algae, respectively). Due to natural algae predisposition to absorb contaminants, the metal content analysis helped to screen the applicability of these extracts, identifying Ulva lactuca as the most suitable source of antioxidants for cosmetic formulations. This MW extract was then adopted to formulate two different preparations, namely a gel and an emulsion. Thermal and mechanical tests confirmed the stability of each formulation, together with neutral organoleptic characteristics. Finally, the actives release was investigated by means of a tape stripping essay, showing an efficient controlled release for gel formulation, even after 7 h of test. The produced cosmeceutics merged non-conventional extraction technologies with formulation expertise, offering a valuable alternative to solve the macroalgae disposal issue

Investigation of process parameters assessment via Design of Experiments for CO2 photoreduction in two photoreactors

CO2 photoreduction with water to obtain solar fuels is one of the most innovative and sustainable processes to harvest light energy and convert it into hydrocarbons. Although photocatalytically active materials and photoreactors have been developed for this purpose, lack of standardisation in testing conditions makes the assessment of process parameters and the comparison of material performance a challenge. Therefore, this paper is aimed at investigating the effect of CO2 photoreduction parameters irradiance and reaction time on production of methane from two photocatalytic rigs. This was pursued through a design of experiments (DOE) approach, which assessed the influence of experimental conditions between different setups. Using low irradiance (40-60 W m-2), reaction time and temperature significantly affected methane production, with a maximum production of 28.50 μmol gcat-1 (40 W m-2, 4 h). When using high irradiance (60-2400 W m-2), only irradiance was found to significantly affect methane production, with a maximum production of 1.90 ∙ 10-1 μmol gcat-1 (1240 W m-2, 2 h). Considering proposed reaction mechanism for CO2 photoreduction, this paper highlights that experimental results give different yet complementary information on the two most important steps of the process, i.e. photoexcitation and surface chemical reaction

A New Green Coating for the Protection of Frescoes: From the Synthesis to the Performances Evaluation

This work presents the formulation and characterization of a new product for the protection of outdoor frescoes from aggressive environmental agents. The formulation is designed as an innovative green coating, prepared through a zero-waste one-pot-synthetic method to form silver nanoparticles (AgNPs) directly in a chitosan-based medium. The AgNPs are seeded and grown in a mixed hydrogel of chitosan, azelaic, and lactic acid, by the reduction of silver nitrate, and using calcium hydroxide as precipitating agent. The rheological properties of this coating base are optimized by the addition of a solvent mixture of glycerol and ethanol with a 1:1 volume ratio. The new formulation and two commercial products (Paraloid® B72 and Proconsol®) are then applied by brush to ad hoc mock-ups to be evaluated for chemical stability, color and gloss variations, morphological variation, hydrophobicity, and water vapor permeability via Fourier-transform infrared spectroscopy (FT-IR) in attenuated total reflection (ATR) mode, spectrophotometer analysis, stereomicroscope observations, UNI EN 15802, and UNI EN 15803, respectively. The results show that the application of the hybrid chitosan-AgNPs coating is promising for the protection of outdoor frescoes and that it can underpin the development of new products that address the lack of conservation strategies specifically designed for wall painting

In vitro systems to predict hepatotoxicity : models based on hepatocarcinoma cell lines

The liver has a major role in the metabolism of both endogenous and exogenous compounds. In drug development, reliable and reproducible results regarding the toxicity of a new compound must be obtained. The gold standard is freshly isolated primary human hepatocytes; however, these are costly, difficult to obtain regularly and cannot be cultured extensively. Secondary hepatocyte cell lines are cheaper with a much longer lifespan in culture but do not accurately reflect the expression profile of a hepatocyte. The aim of this work was to promote differentiation of hepatic carcinoma cell lines towards the in vivo hepatic profile and potentially create a well defined and easily accessible model for early stage drug testing. Initial profiling of HepG2 and Huh7 for differentiation markers, transporters and enzymes was carried out by qPCR. Differentiation was attempted by use of growth factors and dimethyl sulfoxide (DMSO) for periods of up to thirty days. Analysis of differentiation markers by qPCR indicated that 1% DMSO treatment for at least 15 days promoted maturation most effectively. Cells treated with 1% DMSO were analysed for mRNA expression of selected transporters and enzymes, followed by treatment with typical inducers, Western blotting and functional assays to assess the presence and function of certain proteins. Although initial results showed potential, further analyses of the 1% DMSO treated cells were less promising. Analysis of transporter and enzyme mRNA expression revealed that many levels did not change favourably towards those observed in liver, or significantly changed from control but remained vastly removed from liver. Results from protein and induction experiments also indicated no benefit of 15-day DMSO treatment in either cell line. In conclusion, 1% DMSO treatment does not promote differentiation towards a more representative hepatic profile in either cell line; alternative methods are needed to develop a more heptocyte-like model using these cells.EThOS - Electronic Theses Online ServiceBBSRC-CASE award in partnership with Sanofi AventisGBUnited Kingdo