37 research outputs found

    Small-Size Biogas Technology Applications for Rural Areas in the Context of Developing Countries

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    The world’s rural population surpasses the three billion people mainly located in Africa and Asia; roughly half the global population lives in the countryside. Access to modern fuels is a challenge for rural people compared to their urban counterparts, which can easily access infrastructures and commercial energy. In developing countries rural populations commonly depend on traditional biomass for cooking and heating. A key strategy in tackling the energy needs of those rural populations is to advance their energy ladder from the inefficient, traditional domestic burn of biomass, organic waste, and animal manure. Governments and non-governmental institutions have supported small biogas digesters in rural areas, mainly in Asia, South America, and Africa, over the last 50 years. This chapter reviews the literature to offer an overview of experimental and theoretical evidence regarding the characteristics of design, construction material, feedstock, and operation parameters that made anaerobic digestion in small digesters a valuable source. Small-scale rural biogas digesters can generate environmental, health, and social benefits to rural areas with a net positive impact on energy access. Remarkable improvement in living standards was achieved with small inputs of the methane, produced via anaerobic digestion; however, challenges associated with lack of technical skills, awareness, and education remain and obstruct biogas’ full potential in rural areas, mainly in developing countries

    Fine-tuning synthesis of fluorescent silver thiolate nanoclusters

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    Noble metal thiolate nanoclusters are a new class of nanomaterials with molecular-like properties such as high dispersibility and fluorescence in the visible and infrared spectral region, properties highly requested in biomedicine for imaging, sensing and drug delivery applications. We report on three new silver phenylethane thiolate nanoclusters, differing for slight modifications of the preparation, i.e., the reaction solvent and the thiolate quantity, producing changes in the nanocluster composition as well as in the fluorescence behavior. All samples, excited in the range 250-500 nm, emit around 400 and 700 nm differing in the emission maxima and behavior. The silver thiolate nanoclusters have been characterized by way of C, H, S elemental analyses and Thermal Gravimetric Analysis (TGA) to determine the nanocluster composition, Scanning Transmission Electron Microscopy (STEM) to investigate the nanocluster morphology and UV-Vis and fluorescence spectroscopy to study their optical properties

    Exploring the effect of iron metal-organic framework particles in polylactic acid membranes for the azeotropic separation of organic/organic mixtures by pervaporation

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    A microporous carboxylate metal-organic framework MIL-100 Fe was prepared as submicron particles by microwave-assisted hydrothermal synthesis (Fe-MOF-MW). This product was explored, for the first time, for the preparation of polylactic acid (PLA) mixed matrix membranes. The produced MOF was characterised by powder X-ray diffraction (PXRD), environmental scanning electron microscopy (ESEM) as well as by thermogravimetric analysis (TGA) and nitrogen adsorption/desorption. The effect of different Fe-MOF-MW concentrations (0.1 and 0.5 wt%) on the membrane properties and performance were evaluated. These membranes were used in the pervaporation process for the separation of methanol/methyl tert-butyl-ether mixtures at the azeotropic point. The influence of the feed temperature and vacuum pressure on the membrane performance was evaluated and the results were compared with PLA pristine membranes. Moreover, the produced membranes have been characterised in terms of morphology, MOF dispersion in the polymeric membrane matrix, wettability, thickness, mechanical resistance and swelling propensity. The presence of Fe-MOF-MW was found to have a beneficial effect in improving the selectivity of mixed matrix membranes towards methanol at both concentrations. The highest selectivity was obtained for the PLA membranes embedded with 0.5 wt% of Fe-MOF-MW and tested at the temperature of 25 C and vacuum pressure of 0.09 mbar

    Parathyroidectomy and survival in a cohort of Italian dialysis patients: results of a multicenter, observational, prospective study

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    Background: Severe secondary hyperparathyroidism (SHPT) is associated with mortality in end stage kidney disease (ESKD). Parathyroidectomy (PTX) becomes necessary when medical therapy fails, thus highlighting the interest to compare biochemical and clinical outcomes of patients receiving either medical treatment or surgery. Methods: We aimed to compare overall survival and biochemical control of hemodialysis patients with severe hyperparathyroidism, treated by surgery or medical therapy followed-up for 36 months. Inclusion criteria were age older than 18 years, renal failure requiring dialysis treatment (hemodialysis or peritoneal dialysis) and ability to sign the consent form. A control group of 418 patients treated in the same centers, who did not undergo parathyroidectomy was selected after matching for age, sex, and dialysis vintage. Results: From 82 Dialysis units in Italy, we prospectively collected data of 257 prevalent patients who underwent parathyroidectomy (age 58.2 ± 12.8 years; M/F: 44%/56%, dialysis vintage: 15.5 ± 8.4 years) and of 418 control patients who did not undergo parathyroidectomy (age 60.3 ± 14.4 years; M/F 44%/56%; dialysis vintage 11.2 ± 7.6 y). The survival rate was higher in the group that underwent parathyroidectomy (Kaplan–Meier log rank test = 0.002). Univariable analysis (HR 0.556, CI: 0.387–0.800, p = 0.002) and multivariable analysis (HR 0.671, CI:0.465–0.970, p = 0.034), identified parathyroidectomy as a protective factor of overall survival. The prevalence of patients at KDOQI targets for PTH was lower in patients who underwent parathyroidectomy compared to controls (PTX vs non-PTX: PTH < 150 pg/ml: 59% vs 21%, p = 0.001; PTH at target: 18% vs 37% p = 0.001; PTH > 300 pg/ml 23% vs 42% p = 0.001). The control group received more intensive medical treatment with higher prevalence of vitamin D (65% vs 41%, p = 0.0001), calcimimetics (34% vs 14%, p = 0.0001) and phosphate binders (77% vs 66%, p = 0.002). Conclusions: Our data suggest that parathyroidectomy is associated with survival rate at 36 months, independently of biochemical control. Lower exposure to high PTH levels could represent an advantage in the long term. Graphical abstract: [Figure not available: see fulltext.]

    Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

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    Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

    The Impact of COVID-19 on Energy Start-Up Companies: The Use of Global Financial Crisis (GFC) as a Lesson for Future Recovery

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    Purpose: The study discusses COVID-19’s short-term impact on Israel’s renewable energy start-up sector from March to July 2020. Results and contributions: The interviewed companies were experiencing supply chain disruption, logistical issues, and restrictions in work access, all of which negatively impacted business operations. Moreover, companies reported revenue losses and difficulty in securing funding, interpreted here as financial distress. In some cases, companies cut back on staff. Insights from the literature on the global financial crisis (GFC) were used here to discuss patterns discerned from the interviews. Policy recommendations are presented at the end based on both the interpretation of data and a literature review. Methodology: This paper combined the qualitative research analysis of COVID-19’s impacts on energy start-up companies assessed by a questionnaire during interviews with a literature analysis on the previous GFC. Gap: This study aimed to clarify the issues experienced by the start-up companies in the renewable energy sector in Israel during the first months of the pandemic and contributes to the COVID-19 narrative in the energy sector, focusing on a topic that has not been thoroughly discussed at present. Relevance: The paper contains unique primary data on the short-term financial impact of COVID-19 on renewable energy start-up companies, and recommends policies to assist these companies and effectively respond to their financial needs in times of crisis. The paper points out that the absence of such a financial policy for start-up companies might pose risks to the companies’ growth and innovation, and have harmful consequences for the renewable energy sector, energy transition, and climate goals. The attention currently given to initial short-term measures should shift toward a more structural and long-term approach. Impact: The paper wants to capture the attention of policymakers and the research community in evaluating and adequately addressing the financial needs of the start-up sector, which is a crucial segment of the economy, and is indispensable for achieving long-term goals such as energy transition

    Microemulsions: The Renaissance

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    Tailoring MOFs to Biomedical Applications: A Chimera or a Concrete Reality? The Case Study of Fe-BTC by bio-friendly Mechanosynthesis

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    We point-out an exceptional tailorability of iron(III) trimesate metalorganic framework to bio-friendly conditions. This is particularly attractive in sight of one-pot immobilization of biomolecules for biomedical applications. Synthesis is carried out via mechanochemical approach under green, biocompatible conditions without additional solvents, in just 1 hour, at room temperature. Solvents are proven to be unnecessary to build the framework, in contrast to solution-based methods. Microstructure and thermal stability of the material are not affected by pH. Conversely, textural properties can be tuned by simply varying the amount of base

    High Energy Ball Milling and Liquid Crystal Template Method: A Successful Combination for the Preparation of Magnetic Nano-Platforms

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    : In this study, we present the preparation of superparamagnetic ordered mesoporous silica (SOMS) for biomedical applications by the combination of high energy ball milling (HEBM) and the liquid crystal template method (LCT) to produce a material comprised of room temperature superparamagnetic Fe\u2083O\u2084 nanoparticles in a MCM-41 like mesostructured silica. In a typical synthesis, a mixture of Fe\u2082O\u2083 and silica was sealed in a stainless-steel vial with steel balls. Ball milling experiments were performed in a vibratory mill apparatus. The milling process produced nanocomposites with an average size ranging from 3c100-200 nm, where the Fe\u2083O\u2084 nanoparticles (4.8 nm size) are homogeneously dispersed into the amorphous SiO\u2082 matrix. The obtained nanocomposite has been used for the preparation of the SOMS through the LCT method. Structural, morphological and textural characterization were performed using X-ray powder diffraction, transmission electron microscopy and nitrogen sorption analysis. Field dependence of magnetization was investigated and showed superparamagnetic behaviour at 300 K with a value of saturation magnetization (Ms) that is of interest for biomedical applications
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