216 research outputs found

    Domestic heating: Can hemp-hurd derived pellet be an alternative?

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    Among the renewable sources, residual woody biomass from agricultural crops is becoming of great interest due to its lower environmental impact and one of the most growing agricultural sector, of the last decade, is the hemp industry which generates several kind of byproducts. In this paper, a blend of 50% of hemp-hurd and 50% of fir sawdust was pulverized and pelletized. The pellets were burned into a domestic pellet stove (9 kWth maximum nominal thermal power output) at different biomass flowrates. To compare results with a commercial-grade pellet, the tests were repeated by fueling the same stove with A2-grade pellets. Results shown that the pellet mixture 50/50 of fir sawdust and hemp-hurd is suitable for the commercial pellet stove used and that the slightly higher amount of ashes (2.7%), compared to pellet A2 (<1.2%), can be handled by the self-cleaning fire chamber. Comparable results were also obtained in regards with the stove global efficiency which ranged from 90.8-92.3% for the hemp pellets and 91-94% for the A2. A significant difference was noted in the biomass flowrate where, during the tests with hemp-hurd pellets a lower value was obtained (-20%) compared to A2. This resulted into lower power input in the stove and lower performances at the same nominal power output

    Histopathological determinants of autofluorescence patterns in oral carcinoma

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    Biological tissues (including oral mucosa) can absorb and re-emit specific light wavelengths, detectable through spectrophotometric devices. Such a phenomenon is known as \u201cautofluorescence\u201d (AF). Several devices evaluating tissue AF have been developed and commercialized in the last two decades. Among these, the VELscope\uae system has been proposed as a visual diagnostic aid for potentially malignant disorders and malignant lesions of the oral mucosa. In the present pilot study, we investigated which are the main histopathological features possibly related to variations in AF patterns in a set of 20 oral squamous cell verrucous carcinoma. Among all the histological features investigated, only the mean width of keratin was significantly different between hypofluorescent and hyperfluorescent carcinomas. The results of the present study demonstrate that AF features of oral malignant lesions are significantly associated with the width of their keratin layer

    Hand and ultrasonic instrumentation for orthograde root canal treatment of permanent teeth.

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    UNLABELLED: Root canal treatment is a frequently performed dental procedure and is carried out on teeth in which irreversible pulpitis has led to necrosis of the dental pulp. Removal of the necrotic tissue remnants and cleaning and shaping of the root canal are important phases of root canal treatment. Treatment options include the use of hand and rotary instruments and methods using ultrasonic or sonic equipment. OBJECTIVES: The objectives of this systematic review of randomized controlled trials were to determine the relative clinical effectiveness of hand instrumentation versus ultrasonic instrumentation alone or in conjunction with hand instrumentation for orthograde root canal treatment of permanent teeth. MATERIAL AND METHODS: The search strategy retrieved 226 references from the Cochrane Oral Health Group Trials Register (7), the Cochrane Central Register of Controlled Trials (CENTRAL) (12), MEDLINE (192), EMBASE (8) and LILACS (7). No language restriction was applied. The last electronic search was conducted on December 13th, 2007. Screening of eligible studies was conducted in duplicate and independently. RESULTS: Results were to be expressed as fixed-effect or random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. Heterogeneity was to be investigated including both clinical and methodological factors. No eligible randomized controlled trials were identified. CONCLUSIONS: This review illustrates the current lack of published or ongoing randomized controlled trials and the unavailability of high-level evidence based on clinically relevant outcomes referring to the effectiveness of ultrasonic instrumentation used alone or as an adjunct to hand instrumentation for orthograde root canal treatment. In the absence of reliable research-based evidence, clinicians should base their decisions on clinical experience, individual circumstances and in conjunction with patients' preferences where appropriate. Future randomized controlled trials might focus more closely on evaluating the effectiveness of combinations of these interventions with an emphasis on not only clinically relevant, but also patient-centered outcomes

    Experimental investigation of chestnut shells gasification

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    Fossil fuels substitution with renewable energy sources is necessary for an effective decarbonization. Biomass can represent a valid alternative to fossil fuels, reducing greenhouse gas emissions. Furthermore, bioenergy generation avoids costs and problems related to biomass disposal. This study presents the energetic valorisation of chestnut shells, a byproduct of the chestnut transformation processes. Through a thermo-conversion system based on gasification, this material was considered not as a waste, but as a resource to be exploited to produce bioenergy and biochar. The fuel gas produced through the gasification process can partially replace the LPG currently used to meet the energy required for the brulage and steam peeling processes. Experimental gasification tests were carried out to evaluate this biomass by means of a laboratory scale micro-gasifier (Imbert downdraft type). Chestnut shells were pelletized with a pelletizer machine to avoid the bridging effect inside the gasifier and increase its energy density. The fuel gas obtained was sampled and analyzed to measure its composition and HHV. In addition, the gasification efficiency was calculated obtaining a value of 70%, a result in line with the ones obtained with higher quality biomasses

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

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    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

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    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

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

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    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

    Nomophobia in healthcare: an observational study between nurses and students

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    BACKGROUND AND AIM: The abuse of technical devices can be considered a form of addiction that is defined in current literature as Nomophobia. The phenomenon appears to be quite widespread among nurses and nursing students, and nomophobic behaviours of professionals can lead to a reduction in the quality of the care provided. The aim of this study is to investigate the situation in a University and in a hospital in northern Italy and evaluate the levels of nomophobia among nurses and students. METHODS: An observational study was conducted with a questionnaire using a sample of nursing students and nurses.  Both of the studies had the common goal of investigating the levels of nomophobia and   evaluate the comparison between the two groups. RESULTS: In general, neither nurses nor students seem to demonstrate nomophobia's critical levels. The comparison of the daily use of the smartphone between nurses and students shows that the frequent use of students is balanced by the nurses' daily trend line that progressively decreases. Both nurses and students affirm to use their smartphones at work with a certain frequency although, especially among the students, it is usually for appropriate and justified reasons. CONCLUSIONS: It is necessary to consider the development of an educational project that regulates the use of smartphones, explaining the meaning of nomophobia, right from the first year of the University experience so as to correctly address the students'  (and future professionals') behaviours  to make them aware of the misuse of mobile phones, especially in the clinical setting that can easily cause distractions and consequently irreversible  errors

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

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    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

    The usefulness of Moynihan questionnaire in the evaluation of knowledge on healthy diet of patients undergoing cardiology rehabilitation

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    BACKGROUND: The aim of study was to test the usefulness of Moynihan questionnaire in the evaluation of knowledge on healthy diet of patients undergoing cardiology rehabilitation. METHODS: We enrolled 51 patients (pts): 41 men and 10 women, mean age 67.97 +/-11.2 years. The case study included: 21 pts that underwent coronary bypass surgery, 16 pts replaced plastic tube, 14 pts had surgery for the other reasons. All pts underwent nutritional investigation by a dietitian. Anthropometric and biochemical parameters were detected and, by the end, the Moynihan questionnaire was administrated. Pts underwent nutritional coaching, and questionnaire and dietary assessment were rechecked after 3 months. RESULTS: At baseline, the mean Questionnaire score was 22.4 +/- 3.2 points, decreased to 20.6 +/-3.1 points after 3 months (p<0.05). A detailed analysis of the questions showed that the major informations gaps were related to consumption of fruits and vegetables, consumption of fat and salt. In addition pts have acquired more general knowledge about food composition. CONCLUSIONS: The Moynihan questionnaire is an useful instrument of evaluation of dietary knowledge even in selected patients population. In the present study involving patients after cardiac surgery the main difficulties were related to high age of pts, the low cultural level and, mainly, to the post-surgery stress. However, an increase of correct answers as well as an increased knowledge about food composition were detected after educational intervention performed by the dietitian
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