Thermal Stabilization of Digesters of Biogas Plants by Means of Optimization of the Surface Radiative Properties of the Gasometer Domes

A new incentive scheme for power generation from biogas is favoring in Italy the construction of small plants. These ones, however, have poorer financial viability and biological stability than larger plants. In order to ensure adequate performance and a reasonable payback period it is therefore essential that every aspect of their operations is carefully designed. In this respect, summer overheating of anaerobic digesters due to solar gains must be prevented. A solution relies upon the implementation of a ‘cool’ gasometer dome with properly chosen solar reflectance, whose effectiveness was assessed through the use of a calculation code specifically built and validated by comparison with experimental data

Preliminary Investigation of Possible Biochar Use as Carbon Source in Polyacrylonitrile Electrospun Fiber Production

Electrospinning with consequent thermal treatment consists in a carbon fiber production method that spins a polymer solution to create fibers with diameters around a few hundred nanome-ters. The thermal treatments are used for the cyclization and then carbonization of the material at 1700◦C for one hour. The unique structure of micro-and nano-carbon fibers makes them a promis-ing material for various applications ranging from future battery designs to filtration. This work investigated the possibility of using milled gasification biochar, derived from a 20 kW fixed-bed gasifier fueled with vine pruning pellets, as an addictive in the preparation of electrospinning solu-tions. This study outlined that solvent cleaning and the consequent wet-milling and 32 µm sifting are fundamental passages for biochar preparation. Four different polyacrylonitrile-biochar shares were tested ranging from pure polymer to 50–50% solutions. The resulting fibers were analyzed via scanning electron microscopy, and energy-dispersive X-ray and infrared spectroscopy. Results from the morphological analysis showed that biochar grains dispersed themselves well among the fiber mat in all the proposed shares. All the tested solutions, once carbonized, exceeded 97%wt. of carbon content. At higher carbonization temperatures, the inorganic compounds naturally showing in biochar such as potassium and calcium disappeared, resulting in an almost carbon-pure fiber matrix with biochar grains in between

Airborne pathogens diffusion: A comparison between tracer gas and pigmented aerosols for indoor environment analysis

The evaluation of airborne pathogens diffusion is a crucial practice in preventing airborne diseases like COVID-19, especially in indoor environments. Through this transmission route, pathogens can be carried by droplets, droplet nuclei and aerosols and be conveyed over long distances. Therefore, understanding their diffusion is vital for prevention and curbing disease transmission. There are different techniques used for this purpose, and one of the most common is the utilization of tracer gas, however, it has limitations such as the difference in size between the gas molecules and the respiratory droplets, as well as its incapability to take into account evaporation. For this reason, a new method for evaluating the diffusion of respiratory droplets has been developed. This approach involves the use of an ultrasonic emitter to release and disperse pigmented aerosols, and a colorimeter for the following quantitative evaluation. A comparison with the tracer gas technique has been carried out, showing for the pigmented aerosols methodology a response that is dependent on different relative humidity conditions, while there is no clear difference in the dispersion of tracer gas at high or low humidity

Experimental investigation of moisture influence on biochar and biochar-soil blends thermophysical properties

Biochar is a carbonaceous and porous material obtained through pyrolysis or gasification. It can be extremely valuable as soil amendment since it increases the organic matter content and fertility, the microbial activity, the water retention, and the crop yields. Moreover, biochar soil application has the potential for long-term carbon sequestration which makes its application to soil interesting even outside agricultural crops. In recent years, the study of the variation of the thermophysical properties of the soil induced by mixing with biochar has attracted interest. In this work, the effect of the water content on thermal conductivity of biochar was investigated by means of the guarded hot plate apparatus λ-Meter EP500e. The same procedure was applied to various mixtures of biochar and soil. Furthermore, the specific heat was measured in order to obtain the thermal diffusivity in the various conditions through a calorimeter. Solar reflectance was also measured following the ASTM C1549 using a solar spectrum reflectometer SSR-ER. The obtained thermophysical properties can be used for the evaluation of the temperature trend of soil at different depths during the seasonal variations

A technical-economic analysis of integrating vine prunings energy conversion systems for CHP production in local wineries

This study proposes the energy conversion of vine prunings to supply energy to local wineries, with a focus on the Riunite & CIV branch winery located in Carpi (Modena, Italy), exploring the possibility of generating both electricity and heat through biomass gasification. A Matlab-Simulink model is used to evaluate the energy savings that can be achieved when an energy storage system is coupled with the combined heat and power generation system. Within this context, the results showed that it is possible to save approximate to 60% of the thermal energy demanded by the winery. However, the economic viability of the project is hindered by high investment and operation costs. DPB is strongly affected by the cost of biomass and the energy prices, resulting in a profitable investment for electricity prices higher than 0.30(sic)> 0.57 euro/kWh according to the different scenarios investigated

Cognitive reserve index and functional and cognitive outcomes in severe acquired brain injury: A pilot study

Background: Many variables affect outcome after brain injury. Cognitive reserve (CR) is a subjective factor that reflects a set of personal characteristics and that differentiates individuals. It may influence an individual’s capacity to react to brain injury. Objective: To study the effects of cognitive reserve on functional and cognitive outcome at the end of rehabilitation, in patients with severe acquired brain injury (sABI), by means of the Cognitive Reserve Index questionnaire (CRIq). Methods: We report a retrospective study of a continuous series of sABI patients on first admission to a rehabilitation center. Disability and cognitive outcomes were recorded. Results: In the 94 patients enrolled, the assessments after rehabilitation showed a significant gain measured with the disability Rating Scale for patients with a higher CR (CRIq≥ 85). A significant negative correlation was found: between CRIq scores and the interval elapsing before first access to neuropsychological assessment, between CRIq scores, especially level of education, and tests that measure the same domain (attention). Conclusions: Improvements in overall and cognitive disability emerged, but CR did not seem to substantially influence outcome in this sample of patients. This result may be partly due to the clinical severity of the population studied and the sample’s dimension, although quantitatively representative of the population

The impact of transanal local excision of early rectal cancer on completion rectal resection without neoadjuvant chemoradiotherapy: a systematic review

Background The impact of transanal local excision (TAE) of early rectal cancer (ERC) on subsequent completion rectal resection (CRR) for unfavorable histology or margin involvement is unclear. The aim of this study was to provide a comprehensive review of the literature on the impact of TAE on CRR in patients without neoadjuvant chemoradiotherapy (CRT). Methods We performed a systematic review of the literature up to March 2020. Medline and Cochrane libraries were searched for studies reporting outcomes of CRR after TAE for ERC. We excluded patients who had neoadjuvant CRT and endoscopic local excision. Surgical, functional, pathological and oncological outcomes were assessed. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. Results Sixteen studies involving 353 patients were included. Pathology following TAE was as follows T0 = 2 (0.5%); T1 = 154 (44.7%); T2 = 142 (41.2%); T3 = 43 (12.5%); Tx = 3 (0.8%); T not reported = 9. Fifty-three percent were > T1. Abdominoperineal resection (APR) was performed in 80 (23.2%) patients. Postoperative major morbidity and mortality occurred in 22 (11.4%) and 3 (1.1%), patients, respectively. An incomplete mesorectal fascia resulting in defects of the mesorectum was reported in 30 (24.6%) cases. Thirteen (12%) patients developed recurrence: 8 (3.1%) local, 19 (7.3%) distant, 4 (1.5%) local and distant. The 5-year cancer-specific survival was 92%. Only 1 study assessed anal function reporting no continence disorders in 11 patients. In the meta-analysis, CRR after TAE showed an increased APR rate (OR 5.25; 95% CI 1.27-21.8; p 0.020) and incomplete mesorectum rate (OR 3.48; 95% CI 1.32-9.19; p 0.010) compared to primary total mesorectal excision (TME). Two case matched studies reported no difference in recurrence rate and disease free survival respectively. Conclusions The data are incomplete and of low quality. There was a tendency towards an increased risk of APR and poor specimen quality. It is necessary to improve the accuracy of preoperative staging of malignant rectal tumors in patients scheduled for TAE

Predictors for limb amputation and reconstructive management in electrical injuries

BACKGROUND Electrical injuries follow a specific pathophysiology and may progressively damage both skin and deeper tissues, frequently ending in amputations. Type and timing of soft tissue reconstruction after electrical burns is crucial for proper outcome. The aim of this study was to assess surgical management and outcome of patients with electrical injuries treated at the Zurich Burn Center over the last 15 years, with emphasis on risk factors for amputation and reconstructive strategy. METHODS Patient charts were reviewed retrospectively to identify cases admitted at the Zurich Burns Center (2005-2019). Patient characteristics and surgical management, with a special focus on amputations, reconstruction and outcome were analyzed and risk factors for amputation were assessed. RESULTS Eighty-nine patients were identified and a total of 522 operations were performed. Escharotomy and fasciotomies were performed in 40.5% and 24.7% of cases, respectively, mainly at admission. The total amputation rate was 13.5% (23 amputations, 12 patients). Development of compartment syndrome, rhabdomyolysis, high myoglobin and CK blood levels, kidney failure, sepsis and respiratory complications during the course were related to higher risk of amputation (p < 0.001). Sixty-six flap-based reconstructions were performed (25% cases): 49 loco-regional flaps, 3 distant pedicled flaps, 14 free flaps. Two flaps were lost (flap failure rate 14%). Both flap losses occurred in cases of early reconstruction (within 5-21 days). CONCLUSIONS Electrical injuries are still cause of elevated morbidity and mortality, with high amputation rate. Predictors for amputation can support physicians in the surgical care and decision-making. Reconstruction remains challenging in this type of injury: the surgical management with early decompression, serial necrectomies and delayed early reconstruction remains the procedure of choice at our unit

Studying monogenetic volcanoes with a Terrestrial Laser Scanner: Case study at Croscat volcano (Garrotxa Volcanic Field, Spain)

Erosional processes (natural or anthropogenic) may partly destroy the relatively small-sized volcanic edifices characteristic of monogenetic volcanic zones, leaving their internal structure well exposed. Nevertheless, the study of these outcrops may be extremely challenging due to restricted accessibility or safety issues. Digital representations of the outcrop surface have been lately used to overcome such difficulties. Data acquired with terrestrial laser scanning instruments using Light Detection and Ranging technology enables the construction of such digital outcrops. The obtained high-precision 3-D terrain models are of greater coverage and accuracy than conventional methods and, when taken at different times, allow description of geological processes in time and space. Despite its intrinsic advantages and the proven satisfactory results, this technique has been little applied in volcanology-related studies. Here, we want to introduce it to the volcanological community together with a new and user-friendly digital outcrop analysis methodology for inexperienced users. This tool may be useful, not only for volcano monitoring purposes, but also to describe the internal structure of exposed volcanic edifices or to estimate outcrop erosion rates that may be helpful in terms of hazard assessment or preservation of volcanic landscapes. We apply it to the Croscat volcano, a monogenetic cone in the La Garrotxa Volcanic Field (Catalan Volcanic Zone, NE Spain), quarrying of which leads to a perfect view of its interior but restricts access to its uppermost parts. Croscat is additionally one of the most emblematic symbols of the La Garrotxa Volcanic Field Natural Park, and its preservation is a main target of the park administration

Biochar powders coating to improve evaporative cooling in Maisotsenko-cycle systems

This work presents an experimental study on the performance of biochar powder coatings on aluminum surfaces for use in indirect evaporative coolers based on the Maisotsenko cycle. The performance of the biochar coated samples was compared to cellulose-coated aluminum samples and uncoated ones. Results showed that biochar coatings improved the performance of uncoated aluminum, with the 150 μm particle size coating offering performance comparable to cellulose. However, wetting times were longer, which has implications for spraying strategies