123 research outputs found
Experimental and theoretical evaluations on Oleuropein as a natural origin corrosion inhibitor for copper in acidic environment
none5siCopper corrosion in acidic cleaning solutions is a major worry for heat exchangers. Corrosion inhibitors derived from natural sources might be a viable option. The isolation of Oleuropein compound from olive leaf and investigation of its anticorrosion potential for copper in 1.0 M H2SO4 solution are reported here. All experimental results from LC-MS, FT-IR, 1H and 13C-NMR characterizations support the molecular structure of Oleuropein. Electrochemical and gravimetric tests were used to evaluate the corrosion inhibition capabilities of Oleuropein. According to polarization investigation, Oleuropein is a mixed-type inhibitor. Oleuropein's inhibitory efficacy increases with concentration, attaining an optimum value (98.92%) at 100 mg L-1. At high temperatures, Oleuropein can be considered an efficient inhibitor. Thermodynamic variables for the activation operation and copper dissolution were computed and addressed as well. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) examinations revealed that Oleuropein produced an outer layer on the copper surface, shielding it from severe acid damage. Quantum chemical simulations were employed to propose molecular explanations for Oleuropein's inhibitory actions.Deyab, M A; Mohsen, Q; Bloise, E; Lazzoi, M R; Mele, GDeyab, M A; Mohsen, Q; Bloise, E; Lazzoi, M R; Mele,
Dysnatremia is a predictor for morbidity and mortality in hospitalized patients with COVID-19
Context:
Dysnatremia is an independent predictor of mortality in patients with bacterial pneumonia. There is paucity of data about the incidence and prognostic impact of abnormal sodium concentration in patients with coronavirus disease 2019 (COVID-19).
Objective:
This work aimed to examine the association of serum sodium during hospitalization with key clinical outcomes, including mortality, need for advanced respiratory support and acute kidney injury (AKI), and to explore the role of serum sodium as a marker of inflammatory response in COVID-19.
Methods:
This retrospective longitudinal cohort study, including all adult patients who presented with COVID-19 to 2 hospitals in London over an 8-week period, evaluated the association of dysnatremia (serum sodium 145 mmol/L, hyponatremia, and hypernatremia, respectively) at several time points with inpatient mortality, need for advanced ventilatory support, and AKI.
Results:
The study included 488 patients (median age, 68 years). At presentation, 24.6% of patients were hyponatremic, mainly due to hypovolemia, and 5.3% hypernatremic. Hypernatremia 2 days after admission and exposure to hypernatremia at any time point during hospitalization were associated with a 2.34-fold (95% CI, 1.08-5.05; P = .0014) and 3.05-fold (95% CI, 1.69-5.49; P < .0001) increased risk of death, respectively, compared to normonatremia. Hyponatremia at admission was linked with a 2.18-fold increase in the likelihood of needing ventilatory support (95% CI, 1.34-3.45, P = .0011). Hyponatremia was not a risk factor for in-hospital mortality, except for the subgroup of patients with hypovolemic hyponatremia. Sodium values were not associated with the risk for AKI and length of hospital stay.
Conclusion:
Abnormal sodium levels during hospitalization are risk factors for poor prognosis, with hypernatremia and hyponatremia being associated with a greater risk of death and respiratory failure, respectively. Serum sodium values could be used for risk stratification in patients with COVID-19
Synthesis and antibacterial activity of 3-arylidene chromen-2, 4-dione derivatives
Abstract: Derivatives of 3-arylidene chromen-2, 4-dione 1 were synthesized to be used as a starting material for synthesizing some new fused heterocyclic compounds containing coumarin moiety. When compounds 1 reacted with hydrazine derivatives, hydroxylamine hydrochloride, urea, thiourea, semicarbazide and thiosemicarbazide it gave the corresponding compounds 2-5. Compound 4a, b reacted with methyl iodide in DMF and K2CO3 at room temperature to afford the corresponding 6a, b. All these compounds were screened InVitro for their antibacterial activity
TRIZ directed evolution for automobile fuel
Recently, Global Warming effect and Green House Gases (GHG) emissions have become one of the main concern for environment that principally come from the exhaust of fossil fuel combustion process (i.e. coal, crude oil, and natural gas). Electric Vehicles (EVs) industry has started taking the lead and showing significant competition in the market via Plug-in Hybrid Electric Vehicle (PHEV) and fully Battery Electric Vehicle (BEV) over the conventional fossil fuel powered vehicles which are going to ban (prohibit) within coming two decades as officially announced by many of global countries. Battery is the backbone of this evolution and it encourages many researchers and scientists to expedite their studies, experimental tests to discover the best reliable, sustainable, and safe resource of energy to meet the customers’ (vehicles users) values, satisfactions and expectations. This study aims to scientifically predict and analyze the future battery generation that last longer up to (500 km) with improved charging time (less than 30 min). A systematic evolution method called TRIZ (Theory of Inventive Problem Solving) was used in this paper to link the historical data with present timeline in order to improve the main characteristics of the battery (e.g. energy density, durability, charging time and safety). TRIZ has variety of inventive tools (9 – Windows, S – Curve and Function Analysis), these tools are efficiently assist to predict and achieve the next generation of the future battery. By using the tools of Directed Evolution (DE) and utilizing Level of Innovation Domains, battery development is going to be deeply illustrated. Finally, logical recommendations were proposed to those personnel in charge to move forward to approach the future battery system with targeted features and characteristics
Evaluación De La Influencia De Las Condiciones De Fondo De Pozo En El Deterioro De Un Acero API P110, En Ambientes Simulados Del Proceso De Combustión In Situ, Por Gravimetría Y EIS
RESUMEN Dada la gran cantidad de consumo del petróleo como recurso energético, tiene por consecuencia una diminución en el crudo existente a nivel mundial, la explotación del crudo pesado surge como nueva alternativa de extracción que se deja a un lado debido a las dificultades asociadas a su procesamiento. Por lo tanto el proceso de combustión in situ, es un método de extracción que facilita la producción de este tipo de crudo, pues generan un aumento en la producción a expensas de un aumento de los costos asociados a mantenimiento, pues a las condiciones operacionales se favorecen fenómenos como la corrosión de los diferentes materiales involucrados en el proceso, pues están expuestos a atmosferas de sulfuro de hierro (H2S), entre otros gases; a temperaturas y presiones elevadas, lo cual promueve la corrosión y los fenómenos de Sulfide stress cracking. Adicionalmente, los materiales se ven afectados por la acidez y la cantidad de impurezas presentes en el crudo. Por lo anterior se evaluó el comportamiento del acero API P110 expuesto a crudo pesado con diferentes contenidos de azufre (0.5 - 1.5 % en peso), TAN (2.28 - 6.84 g KOH/g crudo) a elevadas temperaturas (190 -250 °C) y presiones (8.96x106 - 11.72x106 Pa), ya que se pueden presentar estas condiciones en el proceso de extracción por combustión in situ en fondos de pozo. Se encontró que el principal mecanismo de corrosión en estas condiciones es la corrosión por sulfidación cuyos principales productos de corrosión son el FeS y óxido de hierro (Fe3O4)
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
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 middle-income 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 low-income 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 low-income, 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
Chemical Additives for Corrosion Control in Desalination Plants
The addition of chemical additives has been considered as a standard
operation in water treatment systems. This chapter discusses the chemical
additives used for the control of corrosion in desalination systems. Specifically,
corrosion inhibitors for various metallurgies, biocides, and oxygen scavengers
are covered. The pros and cons of the additive chemicals have been
highlighted. The need to utilize green corrosion inhibitors based on plants and
ionic liquids materials have been emphasized. This class of materials are
environmentally friendly, cheap, and readily available
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