18 research outputs found
(Methyldiphenylphosphoranylidene)ammonium chloride
The title compound, C13H15NP+·Cl−, was obtained by hydrolysis of the N-trimethysilyl derivative of methydiphenyliminophosphine. The dihedral angle between the phenyl rings in the cation is 61.5 (3)°. In the crystal structure, intermolecular N—H⋯Cl hydrogen bonds links the two components, forming a centrosymmetric 2 + 2 aggregate
Revaluation of agri-food waste to obtain bioethanol
Objective: Bioethanol production from the alcoholic fermentation of agri-food waste.
Design/methodology/approach: Agri-food waste was collected for a month and separated into fruit and legume residues; their size was reduced, and they were washed with hot acetone. A batch of 100 g of residue underwent acid hydrolysis with 5% H2SO4 solution at 125 °C, the hydrolysate was fermented with Saccharomyces cerevisiae at 30 °C for 48 h; the ferment was distilled at 78° C. The amount of sugars was determined by phenol-sulfuric method. The °Brix, density and % w/w of ethanol were measured in a density meter.
Results: From the fruit residues an organic fraction was obtained with a total sugar amount of 53.3 g/100 g of residue and 9.6 °Brix, generating 45 mL of distillate with 3.8 % w/w of bioethanol. The organic fraction from the legume residues had a total amount of sugar of 19.4 g and 4.140 °Brix, generating 30 mL of distillate with 2.5 % w/w of bioethanol.
Limitations on study/implications: The rapid decomposition of waste by the attack of bacteria and fungi complicates its long-term storage.
Findings/conclusions: Fermentable sugars can be obtained from the evaluated agri-food waste to obtain bioethanol. In this way they can be integrated into the value chain as feedstock, reducing their accumulation and the environmental impact generated by their final disposal.Objective: to produce bioethanol from the alcoholic fermentation of agri-food waste.Design/methodology/approach: food waste was collected for one month and separated into fruit and fabaceous waste; its size was reduced and then washed with hot acetone. A batch of 100 g of residue underwent acid hydrolysis with 5 %H 2 SO 4 at 125 °C, the hydrolysate was fermented with Saccharomyces cerevisiae at 30 °C for 48 h; the ferment was then distilled at 78 °C. The sugar content was determined following the phenol-sulfuric method. Brix degrees, density andpercentage w/w ethanol were measured with a densimeter.Results: from the fruit residues, an organic fraction was obtained with a total sugar content of 53.3 g/100 g of residue and 9.6 °Brix, generating 45 mL of distillate with 3.8 % w/w of bioethanol. From the fabaceae residues, an organic fraction was obtained with a total sugar content of 19.4 g and 4.140 °Brix, generating 30 mL of distillate with 2.54 % w/w of bioethanol.Study limitations/implications: Rapid decomposition of waste due to bacterial and fungal decomposition complicates long-term storage.Findings/conclusions: fermentable sugars can be obtained from the evaluated agri-food waste to obtain bioethanol. In this way, they can be integrated into the value chain as raw materials, reducing their accumulation and the environmental impact generated by their final disposal
Eficiencia de los residuos de pasto camalote (Paspalum fasciculatum Willd) en la adsorción del azul de metileno
El Camalote es un pasto perenne que se reproduce rápido y espontáneamente en regiones tropicales. Este pasto no tiene ningún aprovechamiento económico; por el contrario, se le considera una maleza. Sin embargo, es una buena fuente de celulosa y se da en abundancia. En este sentido, el propósito de este trabajo es aprovechar al pasto Camalote como adsorbente del azul de metileno (AM). Las pruebas de adsorción se realizaron en sistema de proceso por lotes, utilizando concentraciones de AM en un rango de 20 a 100 mg/L. La más alta capacidad de adsorción (qe) fue de 43 mg/g para la concentración de 100 mg/L de AM a un pH de 8. Para todas las concentraciones estudiadas se obtuvieron valores de porcentaje de remoción mayor a 80 % en un tiempo de contacto de 30 minutos. Los datos de equilibrio se correlacionaron con los modelos de Langmuir y Freundlich. Los valores de qmax para la isoterma de Langmuir se encuentran en el rango de 19,79 a 94,51 mg g-1 y b entre 0,10 a 0,05 L mg-1. Mientras que para la isoterma de Freundlich se obtienen valores de K que van de 3,79 a 5,13 (mgg-1(L mg-1)-1/n y n entre 2,6 y 1,27, lo que indica que en los sitios activos el AM se retiene por quimisorción, a través de puentes de hidrógeno. Los resultados demostraron que el pasto Camalote en un material eficiente y económicamente viable para remover colorantes de medios acuosos
Using discarded oyster shells to obtain biodiesel
Biodiesel production was studied through the transesterification of used edible vegetable oil, using a calcium oxide (CaO) catalyst derived from Crassostrea Virginica oyster shells. Which were calcined at 900 ° C for 2 hours and characterized by scanning electron microscopy (SEM-EDX), X-ray diffraction (XRD) and infrared spectroscopy (FT-IR). The efficiency of conversion to methyl esters was evaluated using 2%, 3% and 4% of catalyst and they were analyzed by 1H NMR. The results showing that concentrations greater than 2% of CaO generate biodiesel conversions greater than 90%.Objective: To evaluate the CaO made from oyster shell (C. virginica) as a heterogeneous catalyst in the transesterification of edible vegetable oil used for the production of biodiesel.
Design / methodology / approach: A completely randomized experimental design was used, which grouped 3 treatments with 3 repetitions, generating a total of 9 experimental units. The response variable was the performance of the transesterification reaction that was evaluated with 2%, 3% and 4% of CaO obtained from oyster shells. The density, kinematic viscosity, acidity, and conversion efficiency to methyl esters were determined by 1H NMR of the products of each treatment.
Results: The treatment with 3% catalyst showed the highest reaction yield (92.2%) compared to the treatments with 2% (86.8%) and 4% catalyst (87.13%). The 1H NMR spectra confirmed the presence of methyl esters in the product of the three treatments. The treatment with 3% and 4% by weight of catalyst presented products with similar characteristics with acceptable values of density, viscosity and acid number in accordance with the ASTM D6751 and EN1421 standards.
Study limitations / implications: A concentration of 2% by weight of CaO generates a conversion percentage far from the content of methyl esters established by the ASTM D6751 and EN14214 Standards (> 96.5%).
Findings / conclusions: 1H NMR results indicate that the conversion efficiency to methyl esters is positively affected by the amount of catalyst. In the treatments with catalyst loading greater than 2%, the conversion to methyl esters increased significantly to values around 90%
Preparación y caracterización de bioplástico a partir de almidón del fruto de pan de sopa (Artocarpus altilis (s. park) fosberg)
Objective: Obtain and characterize a biodegradable material, using as raw material the breadfruit (Artocarpus altillis (s. park) fosberg) starch.
Desing/methodology/approach: The breadfruit starch was extracted using wet method. The dried starch was mixed with glycerol, water and HCl 1N approx. at 75 °C until obtaining the bioplastic, which was characterized by FT-IR and SEM-EDX spectroscopy.
Results: The highest starch content is obtained in the intermediate stage of fruit development (mature-green) with a 10% yield. Infrared and SEM-EDX tests were performed on both the starch and the bioplastic obtained. The SEM-EDX showed that for the starch the average granule diameter is between 2.5 ± 0.2 to 8.4 ± 0.2 µm with a spherical geometry, with cuts in random directions.
Limitations on study/implications: There are no significant technological limitations, but there are implications that impact the accelerated development of the bioplastics trade.
Findings/conclusions: Breadfruit starch was isolated and characterized with Infrared and SEM-EDX techniques. A bioplastic material was obtained from starch, using glycerol and water as plasticizer, finding that the ratio (1:10, starch: water) generates a material with the best thermoplastic characteristics.Objetivo: Obtener y caracterizar un material biodegradable, utilizando como materia prima el almidón del fruto del pan de sopa (Artocarpus altillis (s. park) fosberg)
Diseño/metodología/aproximación: Se extrajo el almidón del fruto del pan de sopa por el método húmedo. El almidón seco, se mezcló con glicerol, agua y HCl 1N aproximadamente a 75 °C hasta obtener un bioplástico, el cual se caracterizó por espectroscopia de FT-IR y SEM-EDX.
Resultados: El mayor contenido de almidón se obtiene en la etapa intermedia de desarrollo del fruto (verde-maduro) con un 10% de rendimiento. Se realizaron pruebas de infrarrojo y SEM-EDX, tanto del almidón como del bioplástico obtenido. El SEM-EDX mostró que para el almidón el diámetro de granulo promedio es entre 2.5 ± 0.2 a 8.4 ± 0.2 µm con una geometría de tipo esférica, con cortes en direcciones aleatorias.
Limitaciones del estudio/implicaciones: No se observan limitaciones tecnológicas importantes, pero si implicaciones que impactan en el desarrollo acelerado del comercio de bioplásticos.
Hallazgos/conclusiones: Se aisló almidón del fruto pan de sopa y se caracterizó con técnicas de Infrarrojo y SEM-EDX. Se obtuvo un material bioplástico a partir del almidón, empleando como plastificante glicerol y agua, encontrándose que la proporción (1:10, almidón:agua) genera un material con las mejores características de termoplástico
Procurement and characterization of cellulose nanocrystals from cassava bagasse (Manihot esculenta Crantz)
ABSTRACT
Objective:
Obtaining and characterizing cellulose nanocrystals from cassava bagasse.
Design/methodology/approach:
Cellulose nanocrystals were obtained from cassava bagasse by acid hydrolysis (HCI), ultrasonication, centrifugation, dialysis, deep freezing and lyophilization. The cassava bagasse and the cellulose nanocrystals obtained were physiochemically characterized by Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy with Coupled Elemental Analysis (SEM-EDS). As an additional technique, Atomic Force Microscopy (AFM) was used.
Results:
The analyzes performed show that the cellulose obtained was type Iβ. This study reports a percentage of crystallinity of cassava bagasse cellulose of 37.1%, increasing the percentage to 48% of crystallinity in cellulose nanocrystals. The diameters of the cassava bagasse fibers were reported to be 2 μm and their elemental composition (SEM-EDS) mainly constituted by carbon (C), oxygen (O) and traces of (N). The morphology observed through AFM of the nanocrystals of cassava bagasse (Manihot esculenta) was rod-shaped, with a helical appearance without residual charge, with diameters between 8.7 and 9.3 nm.
Limitations on study/implications:
The acid hydrolysis process showed a low percentage of crystallinity, although higher than other works reported for cassava bagasse.
Findings/conclusions:
The results obtained show the possibility of obtaining cellulose nanocrystals from cassava bagasse ().
Objective: To procure and characterize cellulose nanocrystals from cassava bagasse.
Design/methodology/approach: Cellulose nanocrystals were obtained from cassava bagasse by acid hydrolysis (HCI), ultrasonication, centrifugation, dialysis, deep freezing and lyophilization. The cassava bagasse and the cellulose nanocrystals obtained were physicochemically characterized by Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy with Coupled Elemental Analysis (SEM-EDS). As an additional technique, Atomic Force Microscopy (AFM) was used.
Results: The analyses performed show that the cellulose obtained was type Iβ. This study reports a percentage of crystallinity of the cassava bagasse cellulose of 37.1%, increasing the percentage to 48% crystallinity in cellulose nanocrystals. The diameters of the cassava bagasse fibers were reported to be 2 μm and their elemental composition (SEM-EDS) mainly constituted by carbon (C), oxygen (O) and traces of nitrogen (N). The morphology observed through AFM of the nanocrystals of cassava bagasse (Manihot esculenta) was rod-shaped, with helicoidal appearance without residual charge, with diameters between 8.7 and 9.3 nm.
Limitations on study/implications: The acid hydrolysis process showed a low percentage of crystallinity, although higher than other works reported for cassava bagasse.
Findings/conclusions: The results obtained confirm the possibility of obtaining cellulose nanocrystals from cassava bagasse (Manihot esculenta)
Blanqueo de la fibra de celulosa de paja de caña de azúcar (Saccharum spp.) con peróxido de hidrógeno
Objective: Optimize the treatment of cellulose bleaching, replacing the use of sodium hypochlorite with hydrogen peroxide.
Design/methodology/approach: A completely randomized design was used, the treatments were six processes of cellulose bleaching, which were carried out with 18 repetitions. To extract the cellulose, the artisanal method and 40 g of straw were used per treatment. The extraction and yield of cellulose and cellulose fiber, whiteness, crystallinity, granule size, purity of the cellulose and an economic analysis of the cost of the bleaching process were evaluated.
Results: The average cellulose fiber extracted was 14 g, meaning that the yield of cellulose fiber was 35%. The average cellulose was 8 g, which represents a yield of 39.9% cellulose. The whiteness with sodium hypochlorite was 86.6 %, with a crystallinity of 65.9% and the cellulose granule size was 2.6 nm, and with hydrogen peroxide whiteness was 83%, the crystallinity was 68 % and the average granule size was 2.7 nm, according to the XRD method. This means similarity in both bleaching process. According to the FTIR analysis, the cellulose bleached in both processes is similar to the cellulose structure.
Limitations on study/implications: Cellulose bleaching is more expensive with hydrogen peroxide process.
Findings/conclusions: The cellulose extracted from the sugar cane straw, bleached with hydrogen peroxide presents acceptable characteristics to produce artisanal paperObjetivo: Optimizar el tratamiento de blanqueo de celulosa, sustituyendo el uso de hipoclorito de sodio por peróxido de hidrógeno.
Diseño/metodología/aproximación: Se utilizó un diseño completamente al azar, donde los tratamientos fueron seis procesos de blanqueo de celulosa, que se realizaron con 18 repeticiones. Para extraer la celulosa se usó el método artesanal y 40 g de paja por tratamiento. Se evaluó la extracción y rendimiento de fibra de celulosa y celulosa, blancura, cristalinidad, tamaño de gránulo, pureza de la celulosa y un análisis económico del costo del proceso de blanqueo.
Resultados: El promedio de fibra de celulosa extraída fue de 14 g, esto significa que el rendimiento de fibra de celulosa fue 35 %. El promedio de celulosa fue de 8 g que representa un rendimiento de 39.9 % de celulosa. La blancura con hipoclorito de sodio fue del 86.6%, la cristalinidad de 65.9 % y un tamaño de granulo de celulosa de 2.6 nm, y con peróxido de hidrógeno fue del 83 %, la cristalinidad del 68% y el tamaño de granulo promedio fue 2.7 nm, según el método de XRD, indicando resultados similares. De acuerdo al análisis de FTIR, la celulosa blanqueada en ambos procesos, es similar a la estructura de celulosa reportada en la literatura.
Limitaciones del estudio/implicaciones: Se observó un costo más elevado en el blanqueo de la celulosa con el peróxido de hidrógeno.
Hallazgos/conclusiones: La celulosa de la paja de caña de azúcar blanqueada con peróxido de hidrógeno presenta características adecuadas para elaborar papel artesanal
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
(tert-Butyl)(2-hydroxyethyl)ammonium chloride
In the cation of the title molecular salt, C6H16NO+·Cl−, the N—C—C—O torsion angle is 176.5 (2)°. In the crystal, the cations and chloride ions are linked by N—H...O and O—H...O hydrogen bonds, generating a two-dimensional network parallel to (100)