16 research outputs found
Evaluación económica y ambiental de un sitema de tratamiento y eliminación de los RSU en Misurata (Libia) utilizando la metodología coste/beneficio. Proyecto de vertedero controlado
Treball de Fi de Màster Universitari en Eficiència Energètica i Sostenibilitat (Pla de 2018). Codi: SJF019. Curs: 2020/2021La gestión de residuos sólidos urbanos es uno de los desafíos más importantes que enfrentan las ciudades y los ayuntamientos, especialmente en los países en desarrollo, ya que está muy influenciada por la cultura de los países y sus condiciones económicas y sociales, además de ser importantes problemas ambientales y técnicos. El éxito de cualquier país en la gestión de sus desechos es una buena indicación de la capacidad de las agencias gubernamentales interesadas y la población de este país para trabajar juntos para lograr un medio ambiente limpio. La adopción de metodologías sólidas para la gestión de residuos sólidos urbanos, que se realiza mediante el uso de métodos de tratamiento avanzados y adecuados, reduce la contaminación ambiental y las emisiones de gases de efecto invernadero. Confiar en métodos de tratamiento correctos tiene muchos beneficios, incluida la reducción del uso de recursos naturales a través de la reutilización y reciclaje de algunos desechos como papel, cartón, plástico, vidrio, metal, etc., y reducir la necesidad de áreas más grandes para vertederos o sitios de recolección, además de eliminar la reproducción de insectos, microbios dañinos y otros vectores que existen y se multiplican con los desechos. También juega un papel importante en la reducción de las tasas de contaminación ambiental y la propagación de gases de efecto invernadero como el dióxido de carbono y el metano. Esto, a su vez, reduce la contaminación del aire y los olores desagradables alrededor de los vertederos y lugares de reunión, además de mitigar el cambio climático
Surfactant-Free Peroxidase-Mediated Enzymatic Polymerization of a Biorenewable Butyrolactone Monomer via a Green Approach:Synthesis of Sustainable Biobased Latexes
A green surfactant-free one-pot horseradish peroxidase-mediated enzymatic polymerization is successfully applied to produce a sustainable and thermally stable biobased high average molar mass poly(α-methylene-γ-butyrolactone) (PMBL) at ambient conditions in water for the first time. The initiation step required only very low concentrations of hydrogen peroxide and 2,4-pentanedione water-soluble initiator to generate the keto-enoxy radicals responsible for forming the primary latex particles. The polymer nanoparticles can be seen as monodisperse, and the biobased latexes are colloidally stable and likely stabilized by the adsorption of 2,4-pentanedione moieties on the particle surfaces. Polymerizations in air produced a 98% yield of PMBL after only 3 h, highlighting the relevance of molecular oxygen. An array of characterization techniques such as dynamic light scattering (DLS), Fourier transform infrared (FTIR), 1H, 13C, and HSQC two-dimensional (2D) nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and size-exclusion chromatography (SEC) are used to confirm the properties of the synthesized latexes. The PMBL exhibited high thermal stability, with only a 5% weight loss at 340 °C and a glass-transition temperature of 200 °C, which is double that of polymethyl methacrylate (PMMA). This research provides an interesting pathway for the synthesis of sustainable biobased latexes via enzymes in a green environment using just water at ambient conditions and the potential use of the polymer in high-temperature applications.</p
Surfactant-Free Peroxidase-Mediated Enzymatic Polymerization of a Biorenewable Butyrolactone Monomer via a Green Approach:Synthesis of Sustainable Biobased Latexes
A green surfactant-free one-pot horseradish peroxidase-mediated enzymatic polymerization is successfully applied to produce a sustainable and thermally stable biobased high average molar mass poly(α-methylene-γ-butyrolactone) (PMBL) at ambient conditions in water for the first time. The initiation step required only very low concentrations of hydrogen peroxide and 2,4-pentanedione water-soluble initiator to generate the keto-enoxy radicals responsible for forming the primary latex particles. The polymer nanoparticles can be seen as monodisperse, and the biobased latexes are colloidally stable and likely stabilized by the adsorption of 2,4-pentanedione moieties on the particle surfaces. Polymerizations in air produced a 98% yield of PMBL after only 3 h, highlighting the relevance of molecular oxygen. An array of characterization techniques such as dynamic light scattering (DLS), Fourier transform infrared (FTIR), 1H, 13C, and HSQC two-dimensional (2D) nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and size-exclusion chromatography (SEC) are used to confirm the properties of the synthesized latexes. The PMBL exhibited high thermal stability, with only a 5% weight loss at 340 °C and a glass-transition temperature of 200 °C, which is double that of polymethyl methacrylate (PMMA). This research provides an interesting pathway for the synthesis of sustainable biobased latexes via enzymes in a green environment using just water at ambient conditions and the potential use of the polymer in high-temperature applications.</p
Surfactant-Free Peroxidase-Mediated Enzymatic Polymerization of a Biorenewable Butyrolactone Monomer via a Green Approach:Synthesis of Sustainable Biobased Latexes
A green surfactant-free one-pot horseradish peroxidase-mediated enzymatic polymerization is successfully applied to produce a sustainable and thermally stable biobased high average molar mass poly(α-methylene-γ-butyrolactone) (PMBL) at ambient conditions in water for the first time. The initiation step required only very low concentrations of hydrogen peroxide and 2,4-pentanedione water-soluble initiator to generate the keto-enoxy radicals responsible for forming the primary latex particles. The polymer nanoparticles can be seen as monodisperse, and the biobased latexes are colloidally stable and likely stabilized by the adsorption of 2,4-pentanedione moieties on the particle surfaces. Polymerizations in air produced a 98% yield of PMBL after only 3 h, highlighting the relevance of molecular oxygen. An array of characterization techniques such as dynamic light scattering (DLS), Fourier transform infrared (FTIR), 1H, 13C, and HSQC two-dimensional (2D) nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and size-exclusion chromatography (SEC) are used to confirm the properties of the synthesized latexes. The PMBL exhibited high thermal stability, with only a 5% weight loss at 340 °C and a glass-transition temperature of 200 °C, which is double that of polymethyl methacrylate (PMMA). This research provides an interesting pathway for the synthesis of sustainable biobased latexes via enzymes in a green environment using just water at ambient conditions and the potential use of the polymer in high-temperature applications.</p
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Optimizacija kompozitne lopatice vetroturbine sa horizontalnom osovinom na osnovu analize interakcije fluida i strukture
Recently, the world demand has been increased of the energy through a rise of human life level.
The results of the oil price raise and its environment influence, the scientific researches have been
performed on the renewable energy as the alternatives of fossil fuels which are the wind energy one
of renewable energy applications and it is the most promising sources of the renewable energy...Последњих је година дошло до повећања потражње за енергијом махом због пораста
животног стандарда људи широм света. Услед поскупљења нафте и њеног лошег утицаја на
животну средину, научна истраживања се данас усмеравају ка обновљивим изворима
енергије који би требало да замене фосилна горива, а међу њима се енергија ветра издваја
као најперспективнији извор обновљиве енергије..
Optimizacija kompozitne lopatice vetroturbine sa horizontalnom osovinom na osnovu analize interakcije fluida i strukture
Recently, the world demand has been increased of the energy through a rise of human life level.
The results of the oil price raise and its environment influence, the scientific researches have been
performed on the renewable energy as the alternatives of fossil fuels which are the wind energy one
of renewable energy applications and it is the most promising sources of the renewable energy...Последњих је година дошло до повећања потражње за енергијом махом због пораста
животног стандарда људи широм света. Услед поскупљења нафте и њеног лошег утицаја на
животну средину, научна истраживања се данас усмеравају ка обновљивим изворима
енергије који би требало да замене фосилна горива, а међу њима се енергија ветра издваја
као најперспективнији извор обновљиве енергије..
Carrier aggregation in long term evolution advanced
Long Term Evolution-Advanced (LTE-Advanced)
provides considerably higher data rates than even early releases
of LTE. One key enhancement feature is bandwidth extension by
the use of multicarrier technology to support deployment
bandwidth up to 100 MHz. In order to achieve up to 1 Gb/s peak
data rate in IMT-Advanced mobile systems, carrier aggregation
technology is introduced by the 3GPP to support very-high-datarate
transmissions over wide frequency bandwidths (e.g., up to
100 MHz) in its new LTE-Advanced standards. The carrier
aggregation (CA) technology allows scalable expansion of
effective bandwidth provided to a user terminal through
simultaneous utilization of radio resources across multiple
carriers. The CA in LTE-Advanced is designed to support
aggregation of a variety of different arrangements of component
carriers (CCs) , including CCs of the same or different
bandwidths, contiguous or non- contiguous CCs in the same
frequency band, and CCs in different frequency bands. The CA
is supported by both formats of LTE, specifically the frequency
Division Duplex (FDD) and Time Division Duplex (TDD)
variants. This guarantees that both FDD LTE and TDD LTE are
able to meet the high data throughput requirements placed upon
them. This paper provides an outline of carrier aggregation
including aggregation structure, deployment scenarios,
implementation, main design features and backward
compatibility with legacy LTE systems
Surfactant-Free Peroxidase-Mediated Enzymatic Polymerization of a Biorenewable Butyrolactone Monomer via a Green Approach:Synthesis of Sustainable Biobased Latexes
A green surfactant-free one-pot horseradish peroxidase-mediated enzymatic polymerization is successfully applied to produce a sustainable and thermally stable biobased high average molar mass poly(α-methylene-γ-butyrolactone) (PMBL) at ambient conditions in water for the first time. The initiation step required only very low concentrations of hydrogen peroxide and 2,4-pentanedione water-soluble initiator to generate the keto-enoxy radicals responsible for forming the primary latex particles. The polymer nanoparticles can be seen as monodisperse, and the biobased latexes are colloidally stable and likely stabilized by the adsorption of 2,4-pentanedione moieties on the particle surfaces. Polymerizations in air produced a 98% yield of PMBL after only 3 h, highlighting the relevance of molecular oxygen. An array of characterization techniques such as dynamic light scattering (DLS), Fourier transform infrared (FTIR), 1H, 13C, and HSQC two-dimensional (2D) nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and size-exclusion chromatography (SEC) are used to confirm the properties of the synthesized latexes. The PMBL exhibited high thermal stability, with only a 5% weight loss at 340 °C and a glass-transition temperature of 200 °C, which is double that of polymethyl methacrylate (PMMA). This research provides an interesting pathway for the synthesis of sustainable biobased latexes via enzymes in a green environment using just water at ambient conditions and the potential use of the polymer in high-temperature applications.</p
Solid State NMR a Powerful Technique for Investigating Sustainable/Renewable Cellulose-Based Materials
Solid state nuclear magnetic resonance (ssNMR) is a powerful and attractive characterization method for obtaining insights into the chemical structure and dynamics of a wide range of materials. Current interest in cellulose-based materials, as sustainable and renewable natural polymer products, requires deep investigation and analysis of the chemical structure, molecular packing, end chain motion, functional modification, and solvent–matrix interactions, which strongly dictate the final product properties and tailor their end applications. In comparison to other spectroscopic techniques, on an atomic level, ssNMR is considered more advanced, especially in the structural analysis of cellulose-based materials; however, due to a dearth in the availability of a broad range of pulse sequences, and time consuming experiments, its capabilities are underestimated. This critical review article presents the comprehensive and up-to-date work done using ssNMR, including the most advanced NMR strategies used to overcome and resolve the structural difficulties present in different types of cellulose-based materials