177 research outputs found
Energy and environmental assessment of hydrogen from biomass sources: Challenges and perspectives
Hydrogen is considered as one of the pillars of the European decarbonisation strategy, boosting a novel concept of the energy system in line with the EU's commitment to achieve clean energy transition and reach the European Green Deal carbon neutrality goals by 2050. Hydrogen from biomass sources can significantly contribute to integrate the renewable hydrogen supply through electrolysis at large-scale production. Specifically, it can cover the non-continuous production of green hydrogen coming from solar and wind energy, to offer an alternative solution to such industrial sectors necessitating of stable supply. Biomass-derived hydrogen can be produced either from thermochemical pathways (i.e., pyrolysis, liquefaction, and gasification) or from biological routes (i.e., direct or indirect-biophotolysis, biological water–gas shift reaction, photo- and dark-fermentation). The paper reviews several production pathways to produce hydrogen from biomass or biomass-derived sources (biogas, liquid bio-intermediates, sugars) and provides an exhaustive review of the most promising technologies towards commercialisation. While some pathways are still at low technology readiness level, others such as the steam bio-methane reforming and biomass gasification are ready for an immediate market uptake. The various production pathways are evaluated in terms of energy and environmental performances, highlighting the limits and barriers of the available LCA studies. The paper shows that hydrogen production technologies from biomass appears today to be an interesting option, almost ready to constitute a complementing option to electrolysis
Quantification of the carbon intensity of electricity produced and used in Europe
The EU has a comprehensive legislation to facilitate the energy transition towards a low carbon energy system and achieve the EU's Paris Agreement commitments for reducing greenhouse gas emissions. The European Green Deal is an integral part of the EU strategy for a sustainable and climate neutral economy by 2050. The decarbonisation of the power generation is essential to achieve the goal of decarbonising the energy and transport sectors. This paper presents a study conducted to quantify the carbon emissions associated to the production of electricity produced and used in European countries, based on a comprehensive methodology developed for this purpose. A spreadsheet model has been developed that considers the various sources for electricity generation, the type of plants, conversion efficiencies, upstream emissions and emissions from power plant construction, as well as the electricity trade. The results show the greenhouse gas emissions from the production and use of electricity in all European countries, revealing significant variations between countries. The carbon intensity of electricity shows a clear reduction trend since 1990, for most of the European countries. In the European Union, carbon intensity of electricity used at low voltage degreased from 641 gCO2eq/kWh in 1990 to 334 gCO2eq/kWh in 2019, and this trend is expected to continue in the coming years
Potential and limiting factors in the use of alternative fuels in the European maritime sector
The maritime sector is a key asset for the world economy, but its environmental impact represents a major concern. The sector is primarily supplied with Heavy Fuel Oil, which results in high pollutant emissions. The sector has set targets for deacrbonisation, and alternative fuels have been identified as a short-to medium-term option. The paper addresses the complexity related to the activities of the maritime industry, and discusses the possible contribution of alternative fuels. A sector segmentation is proposed to define the consumption of each sub-segment, so to compare it with the current alternative fuel availability at European level. The paper shows that costs and GHG savings are fundamental enablers for the uptake of alternative fuels, but other aspects are also crucial: technical maturity, safety regulation, expertise needed, etc. The demand for alternative fuels has to be supported by an existing, reliable infrastructure, and this is not yet the case for many solutions (i.e. electricity, hydrogen or methanol). Various options are already available for maritime sector, but the future mix of fuels used will depend on technology improvements, availability, costs and the real potential for GHG emissions reduction.(c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
Soils of Mississippi County, Arkansas
Along with air and water, soil contributes essential processes to the natural order of global cycles. With the exception of edibles from the sea, virtually everything we, and most other land-based animals, eat is derived from soil. Soil is a storage medium of essential minerals and nutrients for fulfilling our agricultural and nutritional needs. Humans work the soil to provide the basics of food, clothing, and shelter. We also use the soil as a medium to store and discard our waste. Virtually everything we do is in some way connected to soi
Are algae ready to take off? GHG emission savings of algae-to-kerosene production
Aviation alternative fuels are perceived as an effective short-term mean to decarbonise our flights. Sustainable aviation fuels from algae have been recently approved for commercial flights, and here we present an assessment of their greenhouse gas (GHG) savings. Three case studies have been investigated with different plant designs and cultivation strategies. The Carbon Offsetting and Reduction Scheme for International Aviation's Life Cycle Assessment methodology is used as a guideline to assess the GHG saving potential of aviation fuels from algae. The approach here presented allows having a sound comparison with other alternative fuel production pathways. We show that the cultivation strategy based on oil maximisation does not necessarily provide significant advantages in terms of GHG savings. The assessed GHG savings fall in a wide range, being dependent on the inputs and cultivation strategy considered. In the best-case scenario, up to 68% of GHG savings can be achieved, therefore offering a substantial advantage over traditional fuels. When compared with the GHG saving of kerosene from other traditional bio-based feedstocks, like rapeseed, the results confirm algae as an interesting alternative, provided that certain conditions for their cultivation, such as high process optimisation, nutrient recycling and use of renewable energy to meet input demand, are met. The study also assessed the area potentially needed for an algae production plant able to supply large volumes of raw material to an existing commercial biorefinery. The findings confirm the potential of this feedstock to mitigate land abandonment on the coasts of the Mediterranean basin
Влияние пиелонефрита на эндоэкологическое состояние организма матери и метаболизм аминокислот
Laboratorul Ştiinţific de Obstetrică şi Ginecologie, Institutul de Cercetări Ştiinţifice în Domeniul Ocrotirii Sănătăţii Mamei şi Copilului, Chişinău, Conferinţa Ştiinţifico-Practică „Medicina modernă, actualităţi şi perspective”, consacrată aniversării de 40 de ani ai Spitalului Clinic al Ministerului Sănătăţii, 27-28 mai, 2010, Chişinău, Republica MoldovaAccording to the WHO, the frequency of nefro-urinary diseases occupies the second place in the structure of somatic diseases. During recent
years the incidence of renal disease has increased 2-3 times, including pyelonephritis which is 80% of the total. During pregnancy, birth and
childbed, a number of complications caused by gestational pyelonephritis appeared (severe gestosis, foeto-placental impairment, intrauterine
retardation of fetal development, imminence of premature birth). After the initiation of complex stimulation of lymphatic drainage therapy,
prematurity was reduced by 12%, severe gestatosis decreased by 18%. Fetal retardation was identical in both study groups.По данным ВОЗ, частота заболеваний мочевыделительных путей занимает второе место в структуре соматических патологий. В
последние годы заболеваемость почек возросла в 2-3 раза, в том числе пиелонефрита, который составляет 80% от всей заболеваемости.
Во время беременности, родов и послеродового периода возникает целый ряд осложнений, вызванных гестационным пиелонефритом
(тяжелые гестозы, плодо-плацентарные нарушения, задержка внутриутробного развития плода, преждевременные роды). После начала
терапии комплексной стимуляцией дренажа лимфы, недоношенность была уменьшена на 12%, тяжелые гестозы снизилась на 18%.
Задержка внутриутробного развития плода осталась одинаковой в обеих группах исследования
CORSIA Lower Carbon Aviation Fuels: An Assessment of the Greenhouse Gas Emission Reduction Potential
Curbing aviation emissions is clear goal for the aviation sector, but it is a challenging task. At international level, the ICAO CORSIA initiative promotes the use of alternative fuels as a means to decarbonise flights. Among alternative fuels, lower carbon aviation fuels (LCAF) have been proposed under CORSIA. LCAF refers to a fossil fuel, which have been produced in a way that results in at least 10% lower lifecycle GHG emissions compared to a benchmark value. This paper analyses potential LCAF solutions for reducing GHG emissions of kerosene production and evaluates them relative to the ICAO baseline of 89.0 gCO2eq/MJ of fuel. The study analyses the levers that can reduce GHG upstream emissions (emissions from crude oil production) and refining emissions as well. This study shows that no one lever can reduce emissions to a sufficient level to meet the requirement of being a CORSIA-eligible fuel, and therefore that the deployment of multiple levers needed. Since jet fuel comprises only around 10% of total refining output, the LCAF measures could support the implementation of large, high-abatement cost changes, such as refinery-wide carbon capture and storage that affects multiple fuels
Современные взгляды на преждевременный разрыв амниотического мешка
Laboratorul Ştiinţific de Obstetrică şi Ginecologie, Institutul de Cercetări Ştiinţifice în Domeniul Ocrotirii Sănătăţii Mamei şi Copilului, Chişinău, Conferinţa Ştiinţifico-Practică „Medicina modernă, actualităţi şi perspective”, consacrată aniversării de 40 de ani ai Spitalului Clinic al Ministerului Sănătăţii, 27-28 mai, 2010, Chişinău, Republica MoldovaTraditionally, fetal membrane rupture was attributed to increased physical stress, which weakens the membranes. At the molecular level,
premature rupture of the amniotic sac occurs as a result of collagen synthesis and alteration of the collagen structure in order to accelerate its
degradation. In addition, these biochemical changes can be amplified by biophysical stress as well. The priorities of this research include elucidating
the normal biological processes of fetal membranes, including extracellular matrix remodeling and apoptosis.Традиционно считается, что разрыв фетальных оболочек обусловлен увеличением физических нагрузок. На молекулярном уровне,
преждевременный разрыв амниотического мешка происходит в результате нарушения синтеза коллагена, изменения структуры
коллагена путем ускорения его деградации. Кроме того, биохимические изменения могут быть усилены биофизическим стрессом.
Приоритеты этого исследования включают выяснение нормальный биологической активности плодных оболочек, в том числе
ремоделирование внеклеточного матрикса и апоптоз
Nanostructured Polypyrrole Powder: A Structural and Morphological Characterization
Polypyrrole (PPY) powder was chemically synthesized using ferric chloride (FeCl3) and characterized by X-ray diffraction (XRD), Le Bail Method, Fourier Transform Infrared Spectrometry (FTIR), and Scanning Electron Microscopy (SEM). XRD pattern showed a broad scattering of a semicrystalline structure composed of main broad peaks centered at 2θ = 11.4°, 22.1°, and 43.3°. Crystallinity percentage was estimated by the ratio between the sums of the peak areas to the area of amorphous broad halo due to the amorphous phase and showed that PPY has around 20 (1)%. FTIR analysis allowed assigning characteristic absorption bands in the structure of PPY. SEM showed micrometric particles of varying sizes with morphologies similar to cauliflower. Crystal data (monoclinic, space group P 21/c, a=7.1499 (2) Å, b=13.9470 (2) Å, c=17.3316 (2) Å, α=90 Å, β=61.5640 (2) Å and γ=90 Å) were obtained using the FullProf package program under the conditions of the method proposed by Le Bail. Molecular relaxation was performed using the density functional theory (DFT) and suggests that tetramer polymer chains are arranged along the “c” direction. Average crystallite size was found in the range of 20 (1) Å. A value of 9.33 × 10−9 S/cm was found for PPY conductivity
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