Ultrasound-induced emulsification of subcritical carbon dioxide/water with and without surfactant as a strategy for enhanced mass transport

Pulsed ultrasound was used to disperse a biphasic mixture of CO2/H2O in a 1 dm3 high-pressure reactor at 30 °C/80 bar. A view cell positioned in-line with the sonic vessel allowed observation of a turbid emulsion which lasted approximately 30 min after ceasing sonication. Within the ultrasound reactor, simultaneous CO2-continuous and H2O-continuous environments were identified. The hydrolysis of benzoyl chloride was employed to show that at similar power intensities, comparable initial rates (1.6 ± 0.3 × 10–3 s–1 at 95 W cm–2) were obtained with those reported for a 87 cm3 reactor (1.8 ± 0.2 × 10–3 s–1 at 105 W cm–2), demonstrating the conservation of the physical effects of ultrasound in high-pressure systems (emulsification induced by the action of acoustic forces near an interface). A comparison of benzoyl chloride hydrolysis rates and benzaldehyde mass transport relative to the non-sonicated, ‘silent’ cases confirmed that the application of ultrasound achieved reaction rates which were over 200 times faster, by reducing the mass transport resistance between CO2 and H2O. The versatility of the system was further demonstrated by ultrasound-induced hydrolysis in the presence of the polysorbate surfactant, Tween, which formed a more uniform CO2/H2O emulsion that significantly increased benzoyl chloride hydrolysis rates. Finally, pulse rate was employed as a means of slowing down the rate of hydrolysis, further illustrating how ultrasound can be used as a valuable tool for controlling reactions in CO2/H2O solvent mixtures

Entangled symmetric states of N qubits with all positive partial transpositions

From both theoretical and experimental points of view symmetric states constitute an important class of multipartite states. Still, entanglement properties of these states, in particular those with positive partial transposition (PPT), lack a systematic study. Aiming at filling in this gap, we have recently affirmatively answered the open question of existence of four-qubit entangled symmetric states with positive partial transposition and thoroughly characterized entanglement properties of such states [J. Tura et al., Phys. Rev. A 85, 060302(R) (2012)] With the present contribution we continue on characterizing PPT entangled symmetric states. On the one hand, we present all the results of our previous work in a detailed way. On the other hand, we generalize them to systems consisting of arbitrary number of qubits. In particular, we provide criteria for separability of such states formulated in terms of their ranks. Interestingly, for most of the cases, the symmetric states are either separable or typically separable. Then, edge states in these systems are studied, showing in particular that to characterize generic PPT entangled states with four and five qubits, it is enough to study only those that assume few (respectively, two and three) specific configurations of ranks. Finally, we numerically search for extremal PPT entangled states in such systems consisting of up to 23 qubits. One can clearly notice regularity behind the ranks of such extremal states, and, in particular, for systems composed of odd number of qubits we find a single configuration of ranks for which there are extremal states.Comment: 16 pages, typos corrected, some other improvements, extension of arXiv:1203.371

Holistic Approach to Biodiversity and Bioindication in Soil

To study and investigate soil biodiversity is a difficult task because of the complex interactions that exist in soil and the need for considerable expertise to undertake the necessary investigations. The factors that influence biodiversity are diverse: some are natural, for example soil acidity, water retention, temperature and organic matter content, others are anthropogenic, for example human population pressure. This report summarises the results of the multidisciplinary BIO-BIO study of biodiversity and bioindication, conducted within the Pavia Project, which had as its principal objective the evaluation of the quality and health of soil in Pavia Province, Lombardy, in northern Italy. The area under investigation covered 3000 km2 and the project took into account of the different uses of soil. International standard methods were adopted for the identification of sampling points, the collection, treatment and analysis of the samples for heavy metals, macro-elements, dioxins, furans, soil acidity, physical properties (water retention, pore size, geochemical profile, etc.) and biological data (bacteria and terrestrial mosses). The differences in soil biodiversity that have resulted from different management practices, namely: organic or ¿biological¿ farming; conventional ¿manure¿ farming using animal excreta and mineral fertilizers; and sewage sludge ¿amended¿ applications to soil, have been studied on a seasonal basis (4 sampling per year) and analysis of soil samples taken at 0--5 cm; 0-15 cm and 15-30 cm depth. Some general ideas of what needs to be done in this field are outlined, whilst, at the same time, suggesting the basis for further studies. Bacteria, collembola and earthworms, which cover the three nutritional nets, are the most useful bio-indicators for appraising the evolution of biodiversity and assessing soil quality. To evaluate the biodiversity ¿in soil¿ means to appraise the quality of the soil. Only integrated studies, that take into consideration the chemical, physical and biological nature of soil, will lead to a full understanding of soil biodiversity.JRC.DDG.H.7-Land management and natural hazard

Four-qubit entangled symmetric states with positive partial transpositions

We solve the open question of the existence of four-qubit entangled symmetric states with positive partial transpositions (PPT states). We reach this goal with two different approaches. First, we propose a half-analytical-half-numerical method that allows to construct multipartite PPT entangled symmetric states (PPTESS) from the qubit-qudit PPT entangled states. Second, we adapt the algorithm allowing to search for extremal elements in the convex set of bipartite PPT states [J. M. Leinaas, J. Myrheim, and E. Ovrum, Phys. Rev. A 76, 034304 (2007)] to the multipartite scenario. With its aid we search for extremal four-qubit PPTESS and show that generically they have ranks (5,7,8). Finally, we provide an exhaustive characterization of these states with respect to their separability properties.Comment: 5+4 pages, improved version, title slightly modifie

The pgip family in soybean and three other legume species: evidence for a birth-and-death model of evolution

Polygalacturonase-inhibiting proteins (PGIPs) are leucine-rich repeat (LRR) plant cell wall glycoproteins involved in plant immunity. They are typically encoded by gene families with a small number of gene copies whose evolutionary origin has been poorly investigated. Here we report the complete characterization of the full complement of the pgip family in soybean (Glycine max [L.] Merr.) and the characterization of the genomic region surrounding the pgip family in four legume species. Results: BAC clone and genome sequence analyses showed that the soybean genome contains two pgip loci. Each locus is composed of three clustered genes that are induced following infection with the fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary, and remnant sequences of pgip genes. The analyzed homeologous soybean genomic regions (about 126 Kb) that include the pgip loci are strongly conserved and this conservation extends also to the genomes of the legume species Phaseolus vulgaris L., Medicago truncatula Gaertn. and Cicer arietinum L., each containing a single pgip locus. Maximum likelihood-based gene trees suggest that the genes within the pgip clusters have independently undergone tandem duplication in each species. Conclusions: The paleopolyploid soybean genome contains two pgip loci comprised in large and highly conserved duplicated regions, which are also conserved in bean, M. truncatula and C. arietinum. The genomic features of these legume pgip families suggest that the forces driving the evolution of pgip genes follow the birth-and-death model, similar to that proposed for the evolution of resistance (R) genes of NBS-LRR-type

Parco Nazionale dei Monti Sibillini: suoli e muschi indigeni per valutare le ricadute di elementi in tracce.

Il monitoraggio dell’inquinamento atmosferico è comunemente effettuato impiegando apparecchiature a volte complesse e sofisticate: le centraline elettroniche di rilevamento. Tali strumenti forniscono, in tempo reale e con risultati precisi, l’andamento della concentrazione degli inquinanti. Si tratta di un rilevamento di tipo puntiforme e richiede alti costi di gestione; è necessario cercare nuovi strumenti, che siano in grado di considerare la dispersione, il trasporto e le ricadute degli elementi su vaste aree. Solo i bioindicatori forniscono indicazioni sugli effetti biologici di una determinata situazione di inquinamento, tenendo in considerazione in modo “naturale“ il sinergismo tra le varie sostanze tossiche. Il biomonitoraggio offre, inoltre, garanzie di buona attendibilità, essendo possibile impiegare organismi diversi per vari inquinanti e fornisce informazioni retroattive, poiché i sintomi possono essere riscontrati anche ad una certa distanza dall’episodio di inquinamento. Le piante superiori offrono notevoli possibilità come indicatori, in quanto, avendo scambi gassosi con l’ambiente molto superiori a quelli dell’Uomo e degli animali ed una minor complessità dei sistemi di difesa se si escludono la detossificazione e la riparazione, presentano una sensibilità maggiore nei confronti di molte sostanze inquinanti. La maggior parte delle piante vascolari previene l’assorbimento e la traslocazione degli inquinanti presenti nel suolo, immobilizzandoli nella membrana plasmatica delle radici o nelle ife delle micorrizie. Grazie a questa capacità di “esclusione”, moltissime specie di piante superiori riescono a prevenire eventuali effetti tossici degli inquinanti presenti nel suolo ed a mantenere piuttosto costante la composizione elementare dei loro tessuti. Molti contaminanti atmosferici sono associati al “particolato” e, negli ecosistemi terrestri, le foglie degli alberi e le piante erbacee costituiscono la componente biotica più esposta alla sedimentazione, all’impatto e alla intercettazione degli aerosol. L’intercettazione dipende dalla disposizione e morfologia delle foglie e da ”effetti di superficie” impossibili da riprodurre nelle apparecchiature di campionamento del particellato atmosferico. L’analisi delle piante vascolari è un valido approccio per valutare il trasferimento dei contaminanti ai consumatori primari e ai livelli più elevati delle catene trofiche terrestri. La maggior parte degli alberi tollera concentrazioni piuttosto elevate di inquinanti atmosferici fitotossici; alcune specie sono state introdotte in quasi tutti i continenti e, grazie alla propagazione vegetativa, sono caratterizzate da notevole uniformità genetica. Tra le applicazioni delle piante vascolari, si può ricordare l’uso delle piante del tabacco per biomonitorare l’ozono, l’uso delle Leguminose (erba medica, trifoglio) e di alcune cultivar di bulbose da fiore (tulipano e gladiolo) per valutare, rispettivamente, inquinamento da biossido di zolfo (SO2) e fluoruri. L’utilizzo dei muschi come bioaccumulatori offre notevoli vantaggi nel monitoraggio di elementi in tracce, in quanto essi ricevono prevalentemente le sostanze per il loro sostentamento direttamente dall’ambiente aeriforme che li circonda, riuscendo a vivere in ambienti ad elevata contaminazione. Inoltre, i risultati ottenuti con questa tecnica sono stati confermati da quelli acquisiti con le centraline di monitoraggio convenzionale. Occorre tuttavia precisare che affinchè i dati acquisiti mediante i bioindicatori siano accettati a pieno titolo occorre che tutte le procedure, dal campionamento all'elaborazione dei risultati, seguano in modo scrupoloso norme con un protocollo uniformato. Nel caso specifico, per le informazioni che si volevano trarre, è stata privilegiata la tecnica che vede l’utilizzo dei muschi indigeni (memoria passata) per valutare le deposizioni atmosferiche di origine antropica. Il suolo influisce in minima parte in quanto i muschi sono privi di vere radici e di un tessuto di conduzione per l’acqua; il substrato deve in ogni caso venire raccolto per valutare l’effetto suolo. Il presente studio intende valutare l’accumulo di elementi in tracce derivanti da attività antropiche e/o crostali mediante campioni di suolo e muschio indigeno. Il muschio utilizzato appartiene alla specie Hypnum cupressiforme, che è stata preferita in quanto ubiquitaria su quasi tutto il territorio europeo

Uso de atmosfera controlada para conservação pós-colheita do mamão "Golden".

Frutos de mamoeiro 'Golden' colhidos no estádio 3 de maturação foram armazenados sob controle de atmosfera (3%O2 e 3%CO2 , 3%O2 e 6%CO2 ou 8%CO2 , 5%O2 e 8%CO2) e sob atmosfera ambiente (70% ou 90% U.R.), por 20 ou 25 dias, seguidos de mais 5 dias em atmosfera ambiente, a 10º C. Após 4 dias a 22º C não se verificaram muitas diferenças entre tratamentos, porém o maior teor de sólidos solúveis em frutos armazenados sob 3%O2/3%CO2, e os maiores índices de maturidade nos frutos armazenados sob 3%O2/6%CO2, por 20 dias, sugerem que novos estudos possam ser realizados adotando-se tais concentrações

Feeding Frequency Affects Cultured Rat Pituitary Cells in Low Gravity

In this report, we describe the results of a rat pituitary cell culture experiment done on STS-65 in which the effect of cell feeding on the release of the six anterior pituitary hormones was studied. We found complex microgravity related interactions between the frequency of cell feeding and the quantity and quality (i.e. biological activity) of some of the six hormones released in flight. Analyses of growth hormone (GH) released from cells into culture media on different mission days using gel filtration and ion exchange chromatography yielded qualitatively similar results between ground and flight samples. Lack of cell feeding resulted in extensive cell clumping in flight (but not ground) cultures. Vigorous fibroblast growth occurred in both ground and flight cultures fed 4 times. These results are interpreted within the context of autocrine and or paracrine feedback interactions. Finally the payload specialist successfully prepared a fresh trypsin solution in microgravity, detached the cells from their surface and reinserted them back into the culture chamber. These cells reattached and continued to release hormone in microgravity. In summary, this experiment shows that pituitary cells are microgravity sensitive and that coupled operations routinely associated with laboratory cel1 culture can also be accomplished in low gravity