Evidence for a floating phase of the transverse ANNNI model at high frustration

We study the transverse quantum ANNNI model in the region of high frustration (k>0.5) using the DMRG algorithm. We obtain a precise determination of the phase diagram, showing clear evidence for the existence of a floating phase, separated from the paramagnetic modulated phase by a high-order critical line ending at the multicritical point. We obtain simple and accurate formulae for the two critical lines.Comment: 20 pages, 16 figures. Major revision: numerical evidence improved, presentation clarified, discussion on KT phase transitions added, references update

Parity effects in the scaling of block entanglement in gapless spin chains

We consider the Renyi alpha-entropies for Luttinger liquids (LL). For large block lengths l these are known to grow like ln l. We show that there are subleading terms that oscillate with frequency 2k_F (the Fermi wave number of the LL) and exhibit a universal power-law decay with l. The new critical exponent is equal to K/(2 alpha), where K is the LL parameter. We present numerical results for the anisotropic XXZ model and the full analytic solution for the free fermion (XX) point.Comment: 4 pages, 5 figures. Final version accepted in PR

Improvement of Cellulose Hydrolysis Process and Cost Savings

The hydrolysis process to obtain the so-called \u201creducing sugars\u201d represents the main step involved in the production of the second generation bioethanol. This product can be obtained directly from various types of green biomass, replacing the use of cereals cultivations, with obvious benefits to the environment and the economy of agricultural production. However, it is necessary to improve the hydrolysis process of the cellulose to achieve this goal. To this purpose, we applied a chemical process formerly used. The values of sugars yield were increased by about 40% with respect to the previous study. Further significant cost savings were accomplished, resulting from the recovery of the by-product, calcium sulfate, commercially known as gypsum

Secondary Metabolites in Nectar-Mediated Plant-Pollinator Relationships

n recent years, our understanding of the complex chemistry of floral nectar and its ecological implications for plant-pollinator relationships has certainly increased. Nectar is no longer considered merely a reward for pollinators but rather a plant interface for complex interactions with insects and other organisms. A particular class of compounds, i.e., nectar secondary compounds (NSCs), has contributed to this new perspective, framing nectar in a more comprehensive ecological context. The aim of this review is to draft an overview of our current knowledge of NSCs, including emerging aspects such as non-protein amino acids and biogenic amines, whose presence in nectar was highlighted quite recently. After considering the implications of the different classes of NSCs in the pollination scenario, we discuss hypotheses regarding the evolution of such complex nectar profiles and provide cues for future research on plant-pollinator relationships

Quality Characteristics and Radioactive Contamination of Wood Pellet Imported in Italy

The problem of Caesium-137 (137 Cs) contamination of the imported wood pellet used for burning has been reported in Italy since June 2009. Since then, sampling and analysis were performed at the crossing border points of the provinces of Trieste and Gorizia, on request of the Health and Customs Border Bureau. This paper presents the results of the analysis performed on 65 samples from August 2010 to March 2012, which covered a total of products over 1500 tons of various origins, imported from Eastern Europe and the Balkans. Most of the samples showed very low 137 Cs activity concentrations; only a few hot spots showed 137 Cs activity concentrations higher than 100 Bq 19kg 121. The results of dose evaluations for wood pellet stoves users under the hypotheses assumed in this study were largely below the threshold of radiological relevance

Radiological clinical trials: Proposal of a problem-finding questionnaire to improve study success

open5AIM To develop a survey to help define the main problems in radiological clinical trials. METHODS Since 2006, we have managed seven different radio-logical clinical trials recruiting patients in academic and non-academic centres. We developed a preliminary questionnaire using a four-round Delphi approach to identify problems occurring in radiological clinical trials run at our centre. We investigated the recruitment experience, involvement of all multi-disciplinary team members and main obstacles to completing the projects. A final round of Delphi processes elucidated solutions to the identified problems.openValdora, Francesca; Bignotti, Bianca; Calabrese, Massimo; Houssami, Nehmat; Tagliafico, AlbertoValdora, Francesca; Bignotti, Bianca; Calabrese, Massimo; Houssami, Nehmat; Tagliafico, Albert

Desorption of artemisinin extracts of CIM-Arogya by supercritical carbon dioxide

Artemisinin is a drug for chloroquine resistant malaria and cerebral malaria treatments. In the recent past, there was an acute shortage of this drug and hence World Health Organization made a strategy to fulfil the Artemisinin demand. In this study, artemisinin was extracted by supercritical Carbon Dioxide (SFCO2) from CIM-Arogya, a variety of Artemisia annua, in temperature and pressure ranges of 313.1-333.1 K and 15\u201325 MPa. Artemisinin global yield isotherms were determined obtaining a maximum yield of 3.65 wt%. Artemisinin extracts were also obtained by hexane Soxhlet extraction: then, the crude extracts were purified using SFCO2, after adsorption on silica gel. Different desorption runs were performed with a 6 ml/min CO2 flow rate, in temperature and pressure ranges of 313.1\u2013333.1 K and 15\u201325 MPa. At different time intervals, extracts were collected and analysed: their yields varied from 2.75% to 4.34% function of the experimental conditions. Desorption trials were also correlated with different models