Synthetic polymers blend used in the production of high activated carbon for pesticides removals from liquid phase

For the activated carbon (AC) production, we used the most common industrial and consumer solid waste, namely polyethyleneterephthalate (PET), alone or blended with other synthetic polymer such polyacrylonitrile (PAN). By mixing PET, with PAN, an improvement in the yield of the AC production was found and the basic character and some textural and chemical properties were enhanced. The PET–PAN mixture was subjected to carbonisation, with a pyrolysis yield of 31.9%, between that obtained with PET (16.9%) or PAN (42.6%) separately. The AC revealed a high surface area (1400, 1230 and 1117 m2 g−1) and pore volume (0.46, 0.56 and 0.50 cm3 g−1), respectively, for PET, PAN and PET–PAN precursors. Selected ACs were successfully tested for 4- chloro-2-methylphenoxyacetic acid (MCPA) and diuron removal from the liquid phase, showing a higher adsorption capacity (1.7 and 1.2 mmol g−1, respectively, for MCPA and diuron) and good fits with the Langmuir (PET) and Freundlich equation (PAN and PET–PAN blend). With MCPA, the controlling factor to the adsorption capacity was the porous volume and the average pore size. Concerning diuron, the adsorption was controlled essentially by the external diffusion. A remarkable result is the use of different synthetic polymers wastes, as precursors for the production of carbon materials, with high potential application on the pesticides removals from the liquid phase.

Activated Carbons Produced from Mixtures of Synthetic Polymers by Physical and Chemical Activation: Application on MCPA Removal

The production of AC was achieved using the most common industrial and consumer solid waste, namely PET, alone or blended with other synthetic polymer such PAN. The PET-PAN mixture (1:1 W/W %) was subjected to carbonization, with a pyrolysis yield off 31.9%, between that obtained with PET (16.9%) or PAN (42.6%) separately. By mixing PET, as a raw material, with PAN (different ratio), an improvement in the final yield of the AC production, for the same activation time, with CO2, was found.

Activated Carbons Produced from Mixtures of Synthetic Polymers by Physical and Chemical Activation: Application on MCPA Removal

The production of AC was achieved using the most common industrial and consumer solid waste, namely PET, alone or blended with other synthetic polymer such PAN. The PET-PAN mixture (1:1 W/W %) was subjected to carbonization, with a pyrolysis yield off 31.9%, between that obtained with PET (16.9%) or PAN (42.6%) separately. By mixing PET, as a raw material, with PAN (different ratio), an improvement in the final yield of the AC production, for the same activation time, with CO2, was found.

A novel two-stage discrete crack method based on the screened Poisson equation and local mesh refinement

We propose an alternative crack propagation algo- rithm which effectively circumvents the variable transfer procedure adopted with classical mesh adaptation algo- rithms. The present alternative consists of two stages: a mesh-creation stage where a local damage model is employed with the objective of defining a crack-conforming mesh and a subsequent analysis stage with a localization limiter in the form of a modified screened Poisson equation which is exempt of crack path calculations. In the second stage, the crack naturally occurs within the refined region. A staggered scheme for standard equilibrium and screened Poisson equa- tions is used in this second stage. Element subdivision is based on edge split operations using a constitutive quantity (damage). To assess the robustness and accuracy of this algo- rithm, we use five quasi-brittle benchmarks, all successfully solved.

Production of activated carbons from single and mixtures of synthetic polymers

The production of activated carbons (ACs) involves two main steps: the carbonization of the carbonaceous of raw materials at temperatures below 1073 K in the absence of oxygen and the activation had realized at the temperature up to 1173 but the most useful temperature at 1073 K. In our study we used the most common industrial and consumer solid waste, namely PET, alone or blended with other synthetic polymer PAN. By mixing the two polymers in different ratios, an improvement of the yield of the AC production was found and some textural properties were enhanced by comparison with the AC prepared using each polymer separately. When all the samples were exposed through the carbonization process with a pyrolysis the mixture of PAN-PET (1:1w/w) yield around 31.9%, between that obtained with PET (16.9%) or PAN (42.6%) separately. The combine activation, with CO2 at 1073 K, allow ACs with a lower burn-off degree isothermally, when compared with those attained with PET or PAN alone, but with similarly chemicals or textural properties. The resultant ACs are microporous in their nature, as the activation time increase, the PET-PAN mixture AC are characterized by a better developed porous structure, when associated with the AC prepared from PAN. The AC prepared from PET-PAN mixture are characterized by basic surface characteristics, with a pHpzc around 10.5, which is an important characteristic for future applications on acidic pollutants removals from liquid or gaseous phase. In this study we had used the FTIR methods to determine the main functional groups in the surface of the activated carbons. The adsorbents prepared from PAN fibres presents an IR spectrum with similar characteristics to those obtained with PET wastes, but with fewer peaks and bands with less intensity, in particular for the PAN-8240 sample. This can be reflected by the stretching and deformation modes of NH bond in the range 3100 – 3300 cm-1 and 1520 – 1650 cm-1, respectively. Also, stretching mode associated to C–N, C=N, can contributed to the profile of IR spectrum around 1170 cm-1, 1585 – 1770 cm-1. And the TGA methods was used to study the loses of the precursors mass according to the excessive of the temperature. The results showed that, there were different decreasing of the mass of each precursors. PAN degradation started at almost 573 K and at 1073 K, PAN preserve more than 40% of the initial mass. PET degradation started at 650 K, but at 1073 K, it has lost 80% of the initial mass. However, the mixture of PET-PAN (1:1w/w) showed a thermogravimetric profile between the two polymers tested individually, with a final mass slightly less than 30%. From a chemical point of view, the carbonisation of PET mainly occurs in one step between 650 and 775 K.

Fusarium head blight evaluation and genetic stability in synthetic hexaploid wheats.

2016

Experimental and numerical investigation on short and long term performance of macro-synthetic fibre reinforced concrete materials

Fibre Reinforced Concretes are innovative composite materials whose applications are growing considerably nowadays. Being composite materials, their performance depends on the mechanical properties of both components, fibre and matrix and, above all, on the interface. The variables to account for the mechanical characterization of the material, could be proper of the material itself, i.e. fibre and concrete type, or external factors, i.e. environmental conditions. The first part of the research presented is focused on the experimental and numerical characterization of the interface properties and short term response of fibre reinforced concretes with macro-synthetic fibers. The experimental database produced represents the starting point for numerical models calibration and validation with two principal purposes: the calibration of a local constitutive law and calibration and validation of a model predictive of the whole material response. In the perspective of the design of sustainable admixtures, the optimization of the matrix of cement-based fibre reinforced composites is realized with partial substitution of the cement amount. In the second part of the research, the effect of time dependent phenomena on MSFRCs response is studied. An extended experimental campaign of creep tests is performed analysing the effect of time and temperature variations in different loading conditions. On the results achieved, a numerical model able to account for the viscoelastic nature of both concrete and reinforcement, together with the environmental conditions, is calibrated with the LDPM theory. Different type of regression models are also elaborated correlating the mechanical properties investigated, bond strength and residual flexural behaviour, regarding the short term analysis and creep coefficient on time, for the time dependent behaviour, with the variable investigated. The experimental studies carried out emphasize the several aspects influencing the material mechanical performance allowing also the identification of those properties that the numerical approach should consider in order to be reliable.

Neurophysiological, molecular and pathophysiological aspects of synthetic torpor

Synthetic torpor is a peculiar physiological condition resembling natural torpor, in which even non-hibernating species can be induced through different pharmacological approaches. The growing interest in the induction of a safe synthetic torpor state in non-hibernating species stems from the possible applications that it may have in a translational perspective. In particular, the deeper understanding of the functional changes occurring during and after synthetic torpor may lead to the standardization of a safe procedure to be used also in humans and to the implementation of new therapeutic strategies. Some of the most interesting and peculiar characteristics of torpor that should be assessed in synthetic torpor and may have a translational relevance are: the reversible hyperphosphorylation of neuronal Tau protein, the strong and extended neural plasticity, which may be related to Tau regulatory processes, and the development of radioresistance. In this respect, in the present thesis, rats were induced into synthetic torpor by the pharmacological inhibition of the raphe pallidus, a key brainstem thermoregulatory area, in order to assess: i) whether a reversible hyperphosphorylation of Tau protein occurs at the spinal cord level, also testing the possible involvement of microglia activation in this phenomenon; ii) sleep quality after synthetic torpor and its possible involvement in the process of Tau dephosphorylation; iii) whether synthetic torpor has radioprotective properties, by assessing histopathological and molecular features in animals exposed to X-rays irradiation. The results showed that: i) a reversible hyper-phosphorylation of Tau protein also occurs in synthetic torpor in the dorsal horns of the spinal cord; ii) sleep regulation after synthetic torpor seems to be physiological, and sleep deprivation speeds up Tau dephosphorylation; iii) synthetic torpor induces a consistent increase in radioresistance, as shown by analyses at both histological and molecular level.

Biological analysis of the in-vitro effects of homologous recombination inhibition and its use in cancer treatment through synthetic lethality

Synthetic lethality represents an anticancer strategy that targets tumor specific gene defects. One of the most studied application is the use of PARP inhibitors (e.g. olaparib) in BRCA1/2-less cancer cells. In BRCA2-defective tumors, olaparib (OLA) inhibits DNA single-strand break repair, while BRCA2 mutations hamper homologous recombination (HR) repair. The simultaneous impairment of those pathways leads BRCA-less cells to death by synthetic lethality. The projects described in this thesis were aimed at extending the use of OLA in cancer cells that do not carry a mutation in BRCA2 by combining this drug with compounds that could mimic a BRCA-less environment via HR inhibition. We demonstrated the effectiveness of our “fully small-molecule induced synthetic lethality” by using two different approaches. In the direct approach (Project A), we identified a series of neo-synthesized compounds (named RAD51-BRCA2 disruptors) that mimic BRCA2 mutations by disrupting the RAD51-BRCA2 interaction and thus the HR pathway. Compound ARN 24089 inhibited HR in human pancreatic adenocarcinoma cell line and triggered synthetic lethality by synergizing with OLA. Interestingly, the observed synthetic lethality was triggered by tackling two biochemically different mechanisms: enzyme inhibition (PARP) and protein-protein disruption (RAD51-BRCA2). In the indirect approach (Project B), we inhibited HR by interfering with the cellular metabolism through inhibition of LDH activity. The obtained data suggest an LDH-mediated control on HR that can be exerted by regulating either the energy supply needed to this repair mechanism or the expression level of genes involved in DNA repair. LDH inhibition also succeeded in increasing the efficiency of OLA in BRCA-proficient cell lines. Although preliminary, these results highlight a complex relationship between metabolic reactions and the control of DNA integrity. Both the described projects proved that our “fully small-molecule-induced synthetic lethality” approach could be an innovative approach to unmet oncological needs.

Multifarious tumor-oriented small molecules: development of synthetic methodologies and application for diagnostic platforms

Cancer represents one of the most relevant and widespread diseases in the modern age. In this context, integrin receptors are important for the interactions of cells with extracellular matrix and for the development of both inflammation and carcinogenic phenomena. There are many tricks to improve the bioactivity and receptor selectivity of exogenous ligands; one of these is to integrate the amino acid sequence into a cyclic peptide to restrict its conformational space. Another approach is to develop small peptidomimetic molecules in order to enhance the molecular stability and open the way to versatile synthetic strategies. Starting from isoxazoline-based peptidomimetic molecules we recently reported, in this thesis we are going to present the synthesis of new integrin ligands obtained by modifying or introducing appendages on already reported structures. Initially, we are going to introduce the synthesis of linear and cyclic α-dehydro-β-amino acids as scaffolds for the preparation of bioactive peptidomimetics. Subsequently, we are going to present the construction of small molecule ligands (SMLs) based delivery systems performed starting from a polyfunctionalised isoxazoline scaffold, whose potency towards αVβ3 and α5β1 integrins has already been established by our research group. In the light of these results and due to the necessity to understand the behaviour of a single enantiomer of the isoxazoline-based compounds, the research group decided to synthesise the enantiopure heterocycle using a 1,3-dipolar cycloaddiction approach. Subsequently, we are going to introduce the synthesis of a Reporting Drug Delivery System composed by a carrier, a first spacer, a linker, a self-immolative system, a second spacer and a latent fluorophore. The last part of this work will describe the results obtained during the internship abroad in Prof. Aggarwal’s laboratory at the University of Bristol. The project was focused on the Mycapolyol A synthesis.

Comparazione performance di un'applicazione enterprise basata su service mesh

Ultimamente si stanno sviluppando tecnologie per rendere più efficiente la virtualizzazione a livello di sistema operativo, tra cui si cita la suite Docker, che permette di gestire processi come se fossero macchine virtuali. Inoltre i meccanismi di clustering, come Kubernetes, permettono di collegare macchine multiple, farle comunicare tra loro e renderle assimilabili ad un server monolitico per l'utente esterno. Il connubio tra virtualizzazione a livello di sistema operativo e clustering permette di costruire server potenti quanto quelli monolitici ma più economici e possono adattarsi meglio alle richieste esterne. Data l'enorme mole di dati e di potenza di calcolo necessaria per gestire le comunicazioni e le interazioni tra utenti e servizi web, molte imprese non possono permettersi investimenti su un server proprietario e la sua manutenzione, perciò affittano le risorse necessarie che costituiscono il cosiddetto "cloud", cioè l'insieme di server che le aziende mettono a disposizione dei propri clienti. Il trasferimento dei servizi da macchina fisica a cloud ha modificato la visione che si ha dei servizi stessi, infatti non sono più visti come software monolitici ma come microservizi che interagiscono tra di loro. L'infrastruttura di comunicazione che permette ai microservizi di comunicare è chiamata service mesh e la sua suddivisione richiama la tecnologia SDN. È stato studiato il comportamento del software di service mesh Istio installato in un cluster Kubernetes. Sono state raccolte metriche su memoria occupata, CPU utilizzata, pacchetti trasmessi ed eventuali errori e infine latenza per confrontarle a quelle ottenute da un cluster su cui non è stato installato Istio. Lo studio dimostra che, in un cluster rivolto all'uso in produzione, la service mesh offerta da Istio fornisce molti strumenti per il controllo della rete a scapito di una richiesta leggermente più alta di risorse hardware.