CO2 capture at high temperature and low concentration on Li4SiO4 based sorbents

Solid sorbents based on lithium orthosilicate (Li4SiO4) have shown promise for CO2 capture at high temperature. Improved sorption properties can be obtained by appropriate doping. In this study, different promoted Li4SiO4-based sorbents were prepared by addition of potassium carbonate and binary/ternary alkali (Li, K and Na) carbonate eutectic mixtures. The CO2 sorption properties of the sorbents were investigated by thermal gravimetric analysis (TGA) at different temperatures in the range between 500 and 600 °C and at low CO2 partial pressure (0.04 atm). The results showed that all the promoters used noticeably improved the CO2 sorption capacity in comparison to no-promoted Li4SiO4. At the optimum sorption temperature of 580 °C, Li4SiO4 with addition of 30 wt% of K2CO3 showed the best CO2 adsorption proprieties with sorption capacities of 230 mg CO2/g sorbent corresponding to a conversion of about 80 %. Besides this sample maintained its original capacity during multiple CO2 sorption/desorption cycles

Employment of portable gamma-ray spectrometer in survey and mapping of intrusive complexes: a case study from the Buddusò pluton (Sardinia)

http://www.fe.infn.it/u/mantovani/CV/Proceedings/Puccini_10a.pd

Natural radioactivity in Sardinian granite dimension stones

http://www.fe.infn.it/u/mantovani/CV/Proceedings/Puccini_10b.pd

Validation of a small scale woody biomass downdraft gasification plant coupled with gas engine

In recent years, small scale cogeneration systems (< 500 kWe) distributed in different geographical locations using biomass has received special attention as economically competitive and environmentally friendly ways of producing energy. These systems can be integrated to industrial and agricultural activities where biomass residues are generated and can be converted into electricity and thermal energy by combustion or gasification. The legislations of many European countries such as Italy concerning renewable energy and energy efficiency along the taxation schemes have raised the incentives for small scale cogeneration plants. Consequently, there is a clear economic interest of the companies in this sector and there is also a scientific interest towards demonstration of their energetic efficiency, environmental performance and reliability. Among the suggested technologies for the biomass conversion into energy, downdraft gasification (using air as gasification agent), coupled with internal combustion engines, has the advantage of high electric efficiency (~ 25%) and low tar generation, making easier the gas cleaning process necessary for its use into engines. In the present work, the results of a measurement campaign performed on a commercial scale 350 kWth downdraft woodchips gasification plant, coupled with an SI internal combustion engine (ICE), are presented and discussed. The main goals of this first experimental campaign have been to verify the stability of gasifier and engine operation, operability of the plant and to determine its energy efficiency. The campaign verified a stable operation of the gasifier and the plant produced a syngas with a composition suitable for a gas engine. The energy balance resulted in a potential overall wood fuel to electricity efficiency of about 23 %

Geochronology of late Variscan magmatism of Sardinia: a review

Sardinia represents a southern transect of the Variscan Belt and is classically divided from SW to NE into a fold and thrust belt Foreland, Nappe zone and Axial zone. This latter high-grade domain is separated from the Nappe zone by the so-called Posada-Asinara Line. The whole metamorphic basement is intruded by many calc-alkaline coalescent plutons forming the Corsica-Sardinia Batholith. The timing of magmatism, in Sardinia, is broadly referable to a large interval in the range of 320-280 Ma. Recent geological maps coupled to several chronological systematics, point out to recognize two main post-collisional magmatic peaks clustered at about 305 Ma (Older Magmatic Peak, OMP) and at 285 Ma (Young Magmatic Peak, YMP), respectively. Plutons intruding different parts of the Sardinian basement show different geological styles. Among the OMP, main differences regard: (a) the granodiorite/granite volume ratio in the main plutons; (b) the abundance of peraluminous rock-types; (c) the occurrence of mafic intrusions; (d) the abundance of late-magmatic dyke swarms. The Axial zone is dominated by monzogranites and subordinate granodiorites and leucogranites (320-307 Ma); tonalites and granodiorites (305-300 Ma), along with peraluminous granites, characterize the inner Nappe zone (i.e., Goceano, Baronie, Barbagia). Remarkably, the oldest intrusions (i.e., Barrabisa and Santa Maria: 320 Ma) are foliated and may represent a prebatholith magmatic phase. Plutons occurring in the external Nappe zone and the Foreland are generally dominated by granodiorites (e.g., Arbus, Ogliastra, Sàrrabus: 305-300 Ma) associated to small gabbronoritic bodies. The YMP is marked in the Axial zone by large leucogranite intrusions (Monte Lerno); gabbroic intrusions are present at 285-280 Ma. The YMP is dominant in the external Nappe zone and in the Foreland. This peak include monzogranites and leucogranites with minor granodiorites; specific characters are: (a) common occurrence of F-bearing, ferroan, ilmeniteseries granitoids; (b) slightly peraluminous character; (c) very shallow emplacement levels, with common greisen alteration; (d) presence of Sn-W-Mo and F ores; (e) association to swarms of tholeiitic mafic dikes. The timing and distribution of Sardinian intrusive magmatism are tentatively framed during the post-collisional evolution of the chain, in response to progressive lithospheric delamination along a N-S direction. In this model, the passive upwelling of hot astenosphere triggered dehydration melting at lower to intermediate crustal levels, associated with minor melting of the lithospheric mantle. Several major issues emerge from this schematic picture, including (a) the precise timing of the magmatic peaks, (b) the significance of the gap between them, (c) the difference in volumes and spatial distribution of the main rock-suites, (d) the geological and petrological frame at the district- to single pluton-, up to regional scale, and (e) the age of mafic dyke swarms

Conversion of the hydrochar recovered after levulinic acid production into activated carbon adsorbents

Levulinic acid production by acid-catalyzed hydrothermal conversion of (ligno)cellulosic biomass generates significant amounts of carbonaceous hydrochar, which is currently considered a final waste. In this work, the hydrochar recovered after the levulinic acid production, was subjected to cascade pyrolysis and chemical activation treatments (by H3PO4 or KOH), to synthesize activated carbons. The pyrolysis post-treatment was already effective in improving the surface properties of the raw hydrochar (Specific Surface Area: 388 m2/g, VP: 0.22 cm3/g, VMESO: 0.07 cm3/g, VMICRO: 0.14 cm3/g), by removing volatile compounds. KOH activation resulted as the most appropriate for further improving the surface properties of the pyrolyzed hydrochar, showing the best surface properties (Specific Surface Area: 1421 m2/g, VP: 0.63 cm3/g, VMESO: 0.10 cm3/g, VMICRO: 0.52 cm3/g), which synergistically makes it a promising system towards adsorption of CO2 (∼90 mg/g) and methylene blue (∼248 mg/g). In addition, promising surface properties can be achieved after direct chemical activation of the raw hazelnut shells, preferably by H3PO4 (Specific Surface Area: 1918 m2/g, VP: 1.34 cm3/g, VMESO: 0.82 cm3/g, VMICRO: 0.50 cm3/g), but this choice is not the smartest, as it does not allow the valorization of the cellulose fraction to levulinic acid. Our approach paves the way for possible uses of these hydrochars originating from the levulinic acid chain for new environmental applications, thus smartly closing the biorefinery loop of the hazelnut shells

Are Vascularized Fibula Autografts a Long-lasting Reconstruction After Intercalary Resection of the Humerus for Primary Bone Tumors?

BackgroundA vascularized fibula graft (VFG) is the vascular autograft most frequently used to restore large segmental long bone defects, particularly in the upper limb. Because the use of a vascularized fibula involves an operation in an uninvolved extremity with potential morbidity, it is important to document that this type of reconstruction is successful in restoring function to the humerus. However, the long-term results of VFG after intercalary resection of the humeral diaphysis for bone tumors are still unknown.Questions/purposes(1) What was the complication rate of reconstruction? (2) What was the functional result after surgical treatment, as assessed by the Musculoskeletal Tumor Society (MSTS) score, the American Shoulder and Elbow Society (ASES) score, and Constant score? (3) What was the survivorship of these grafts free from revision and graft removal at 5, 10, and 15 years?MethodsBetween 1987 and 2021, 127 patients were treated at our institution with en bloc resection for a primary malignant or an aggressive benign bone tumor of the humerus; we excluded patients treated with extra-articular resection or amputation. Of those, 14% (18 of 127) were treated with intercalary resection of the humeral diaphysis for primary bone tumors and reconstruction with VFG, with or without a bulk allograft, and were analyzed in this retrospective study. Generally, our indications for reconstruction with VFG are intercalary resection of the humerus for primary malignant or aggressive benign bone tumors in patients with long life expectancy and high functional demands, in whom adequate bone stock of the proximal and distal epiphysis can be preserved. In 13 patients, VFG was used alone, whereas in five patients, a massive allograft was used. Our policy was to use VFG combined with a massive allograft in patients undergoing juxta-articular joint-sparing resections in which proximal osteotomy was performed close to the anatomic neck of the humerus to obtain more stable fixation and better tendinous reattachment of the rotator cuff and deltoid. All 18 patients who were treated with a VFG were available for follow-up at a minimum of 2 years (median follow-up 176 months, range 26 to 275 months), and although three have not been seen in the past 5 years and are not known to have died, they had 172, 163, and 236 months of follow-up, and were included. The median age at surgery was 25 years (range 2 to 63 years), the median humeral resection length was 15 cm (range 8 to 21 cm), and the median fibular length was 16 cm (range 12 to 23 cm). Complications and functional scores were ascertained by chart review that was performed by an individual not involved in patient care. Functional results were assessed with the MSTS score (range 0 to 30), the ASES score (range 0 to 100), and the Constant score (range 0% to 100%). Survivorship was estimated using a Kaplan-Meier survivorship estimator, which was suitable because there were few deaths in this series.ResultsSeven patients underwent a revision procedure (one radial nerve transient palsy because of screw impingement, four nonunions in three patients with one humeral head avascular necrosis, treatment for screw-related pain in one patient, and two VFG fractures), and one patient underwent VFG removal. Donor site complications were observed in four patients (one ankle valgus deformity and three claw toes - the first toe in two patients and the other toes in the third). At the final clinical control, at a median follow-up of 176 months (range 26 to 275 months), the median MSTS score was 30 of 30 (range 28 to 30), the median ASES score was 98.3 (range 93 to 100), and the median Constant score was 93.5% (range 79% to 100%). Revision-free survival was 71% (95% CI 53% to 96%) at 5 years and 57% (95% CI 37% to 88%) at 10 and 15 years; VFG removal-free survival was 94% (95% CI 83% to 100%) at 5, 10, and 15 years.ConclusionVFG appears to be an effective reconstructive option after humeral intercalary resection for primary bone tumors. These are complex procedures and should be performed by an experienced team of surgeons who recognize that complications may occur frequently in the first years after the procedure. The frequency of mechanical complications observed in the first 5 years postoperatively may be lessened by using long spanning-plate fixation, and if successful, this reconstruction provides a long-term, durable reconstruction with excellent functional results.Level of EvidenceLevel IV, therapeutic study

Tear production, intraocular pressure, ultrasound biometric features and conjunctival flora identification in clinically normal eyes of two italian breeds of chicken (Gallus gallus domesticus)

Given the abundance of chickens in Italy, it is important for veterinarians to know the normal state of chickens’ eyes in order to identify any ophthalmic pathological changes. The aim of this study was to determine the normal values of select ocular parameters and to evaluate conjunctival microflora in two Italian chicken breeds. Sixty-six healthy chickens underwent a complete ophthalmic examination, which included a phenol red thread test (PRTT) for the evaluation of tear production and the assessment of intraocular pressure by rebound tonometry. B-mode ultrasound biometric measurements and conjunctival microflora identification were also performed in twenty-seven chickens. Mean PRTT was 23.77 ± 2.99 mm/15 s in the Livorno breed and 19.95 ± 2.81 mm/15 s in the Siciliana breed. Mean intraocular pressure was 14.3 ± 1.17 mmHg in the Livorno breed and 14.06 ± 1.15 mmHg in the Siciliana breed. Reference ranges for morphometric parameters were reported in the two breeds. Twenty-three chickens (85.18%) were bacteriologically positive. Chlamydia spp. antigen was detected in 14.81% of chickens. No positive cultures were obtained for fungi. Normal reference range values for selected ophthalmic parameters were obtained in clinically healthy chickens, which could facilitate accurate diagnosis and better management of ophthalmic diseases in these animals