Fluidized bed gasification of biomass from plant-assisted bioremediation: Fate of contaminants

Fluidized-bed gasification (FBG) of Phyto-assisted Bioremediation (PABR) biomass is analyzed focusing on the contaminants' dispersion. Poplar pruning coming from an area contaminated by polychlorinated biphenyls (PCBs) and heavy metals (HM) are considered. The biomass analysis showed relevant contents in HMs, especially Cd and Cr, and no significant PCB content. FBG process was analyzed to: a) track pollutants, b) detect contaminants in the FBG and c) investigate the HMs concentration in the produced streams. The results showed that most of the metals are concentrated in the ashes collected in the bottom of the reactor (Pb, Cd, Cu, Cr), or in the cyclone (B, Na, Mg, Al, K and Fe). Interestingly, metals are also released by the olivine bed (Mg, Fe, Ni and Al) and transported downstream. Consistent fractions of Zn and Fe (also Cu) were detected in the fugitive ashes. As for the Volatile Organic Compounds (VOC) concentration, we noted similarities between PABR and virgin biomass syngas streams. A reduced-scale process was carried out in TGA-DTA to investigate the potential of such technique in reproducing the main features of the FBG process. Comparable results were obtained, thus suggesting its possible application for small-scale preliminary assessment of FBG process

Characterization of marble weathering through pore structure quantitative analysis

Y Stone weathering is strongly controlled by the intrinsic properties of the stone and by its use. Previous studies demonstrate that the response to natural or artificial ageing processes of the rocks seems to be strongly influenced by the pore structure of the stone. A better understanding of this phenomenon is provided by the study and characterization of porosity and of the pore structure at different degrees of alteration. The analysis of the evolution of the decay leads to the evaluation of the durability of marble in facades, and more generally in buildings, as well as for the protection and recovery of artistic and architectural heritage.In this paper, we apply a methodology for the geometrical characterization of the pore structure to quantify alteration induced by natural weathering on marble slabs. The approach is based on the application of a path-finding algorithm to 2D binary images representative of thin sections of marble at different degrees of alteration. Through the identification of the paths within the porous domain, the methodology allows the characterization of the pore structure in terms of pore radius distribution along the identified paths. Analysis of the results demonstrate a good agreement between the degree of alteration of the pore structure and the corresponding variation of the physical and mechanical properties of the rock samples under investigation

States of 15C via the (18O,16O) reaction

A study of the 15C states was pursued in 2008 at the Catania INFN-LNS laboratory by the 13C(18O,16O)15C reaction at 84 MeV incident energy. The 16O ejectiles were detected at forward angles by the MAGNEX magnetic spectrometer. Thanks to an innovative technique the ejectiles were identified without the need of time of flight measurements. Exploiting the large momentum acceptance (25%) and solid angle (50 msr) of the spectrometer, the 15C energy spectra were obtained with a quite relevant yield up to about 20 MeV excitation energy. The application of the powerful technique of the trajectory reconstruction did allow to get an energy resolution of about 250 keV FWHM, limited mainly by straggling effects. The spectra show several known low lying states up to about 7 MeV excitation energy as well as two unknown resonant structures at about 11.4 and 13.5 MeV. The strong excitation of these latter together with the measured width of about 2 MeV FWHM could indicate the presence of collective modes of excitation connected to the transfer of a correlated neutron pair

Harmonic Pulse Testing for Well Monitoring: application to a fractured geothermal reservoir

Harmonic Pulse Testing (HPT) has been developed as a type of well testing applicable during ongoing field operations because a pulsed signal is superimposed on background pressure trend. Its purpose is to determine well and formation parameters such as wellbore storage, skin, permeability and boundaries within the investigated volume. Compared to conventional well testing, HPT requires more time to investigate the same reservoir volume. The advantage is that it does not require the interruption of well and reservoir injection/production before and/or during the test because it allows the extraction of an interpretable periodic signal from measured pressure potentially affected by interference. This makes it an ideal monitoring tool. Interpretation is streamlined through diagnostic plots mimicking conventional well test interpretation methods. To this end, analytical solutions in the frequency domain are available. The methodology was applied to monitor stimulation operations performed at an Enhanced Geothermal System (EGS) site in Pohang, Korea. The activities were divided into two steps: first a preliminary sequence of tests, injection/fall‐off and two HPTs, characterized by low injection rates and dedicated to estimate permeability prior to stimulation operations; then stimulation sequence characterized by higher injection rate. During the stimulation operations other HPTs were performed to monitor formation properties behavior. The interpretation of HPT data through the derivative approach implemented in the frequency domain provided reliable results in agreement with the injection test. Moreover, it provided an estimation of hydraulic properties without cessation of stimulation operations, thus confirming the effectiveness of HPT application for monitoring purposes

Preliminary study of the 19F(7Li,7Be)19O reaction at 52 MeV with MAGNEX

The 19F(7Li,7Be)19O charge-exchange reaction at 52 MeV incident energy has been performed at INFN-LNS in Catania using the MAGNEX spectrometer. The use of an algebraic ray-reconstruction technique has allowed to extract the 19O excitation energy spectrum and the experimental angular distributions obtained with a single angular setting of the spectrometer

Obstetric anal sphincter injury: a systematic review of information available on the internet.

OBJECTIVE: There is no systematic evaluation of online health information pertaining to obstetric anal sphincter injury. Therefore, we evaluated the accuracy, credibility, reliability, and readability of online information concerning obstetric anal sphincter injury. MATERIALS AND METHODS: Multiple search engines were searched. The first 30 webpages were identified for each keyword and considered eligible if they provided information regarding obstetric anal sphincter injury. Eligible webpages were assessed by two independent researchers for accuracy (prioritised criteria based upon the RCOG Third and Fourth Degree Tear guideline); credibility; reliability; and readability. RESULTS: Fifty-eight webpages were included. Seventeen webpages (30%) had obtained Health On the Net certification, or Information Standard approval and performed better than those without such approvals (p = 0.039). The best overall performing website was http://www.pat.nhs.uk (score of 146.7). A single webpage (1%) fulfilled the entire criteria for accuracy with a score of 18: www.tamesidehospital.nhs.uk . Twenty-nine webpages (50%) were assessed as credible (scores ≥7). A single webpage achieved a maximum credibility score of 10: www.meht.nhs.uk . Over a third (21 out of 58) were rated as poor or very poor. The highest scoring webpage was http://www.royalsurrey.nhs.uk (score 62). No webpage met the recommended Flesch Reading Ease Score above 70. The intra-class coefficient between researchers was 0.98 (95% CI 0.96-0.99) and 0.94 (95% CI 0.89-0.96) for accuracy and reliability assessments. CONCLUSION: Online information concerning obstetric anal sphincter injury often uses language that is inappropriate for a lay audience and lacks sufficient accuracy, credibility, and reliability

How underground systems can contribute to meet the challenges of energy transition

The paper provides an overview of the several scientific and technical issues and challenges to be addressed for underground storage of carbon dioxide, hydrogen and mixtures of hydrogen and natural gas. The experience gained on underground energy systems and materials is complemented by new competences to adequately respond to the new needs raised by transition from fossil fuels to renewables. The experimental characterization and modeling of geological formations (including geochemical and microbiological issues), fluids and fluid-flow behavior and mutual interactions of all the systems components at the thermodynamic conditions typical of underground systems as well as the assessment and monitoring of safety conditions of surface facilities and infrastructures require a deeply integrated teamwork and fit-for-purpose laboratories to support theoretical research. The group dealing with large-scale underground energy storage systems of Politecnico di Torino has joined forces with the researchers of the Center for Sustainable Future Technologies of the Italian Institute of Technology, also based in Torino, to meet these new challenges of the energy transition era, and evidence of the ongoing investigations is provided in this paper