Comparison of Crossflow Turbine Performance through Nozzle Position Variations Using ANSYS Simulation

The performance comparison of Crossflow turbines is greatly influenced by the position of the nozzle in the conversion of water energy into mechanical energy that occurs through the blades, runners, and shafts of Crossflow turbines. The study aims to directly examine the visualization of water fluid dynamics across the turbine runner blade and enhance the performance of the Crossflow turbine by varying the nozzle position. This study intends to investigate the impact of water flow dynamics and emission on the performance of Crossflow turbines with a combined horizontal-vertical nozzle position, specifically focusing on the magnitude of the number of turbine blades driven and the size of the runner blade area. The objective of investigating nozzle position variations in Crossflow turbines is to determine the specific nozzle position at which the turbine blade may efficiently extract maximum energy from the water flow, hence optimizing turbine performance. The research method using models made using CAD software is AutoCAD by exporting to IGES or IGS format to be compatible with ANSYS. The simulation of this research is with post-processing. There are three, namely making animations, making contours, and taking data to compare cross-turbine performance using variations in nozzle position. Crossflow turbine performance with horizontal nozzle position torque and turbine power is lower, and there is an increase in a vertical position. Then, the horizontal and vertical nozzle position is very good because the nozzle is more effective with maximum turbine performance, namely 13.811-watt turbine power 1,099 turbine torque at 120 rpm

PENGUJIAN TURBIN CROSS FLOW EMPAT NOSSEL VERTIKAL

PENGUJIAN  TURBIN  CROSS FLOW  EMPAT  NOSSEL VERTIKA

PENERAPAN PENDINGIN IKAN RAMAH LINGKUNGAN

PENERAPAN PENDINGIN IKAN RAMAH LINGKUNGA

OPTIMASI KINERJA TURBIN CROSS FLOW DENGAN TIGA NOSSEL

OPTIMASI KINERJA TURBIN CROSS FLOW DENGAN TIGA NOSSE

The role of stearic acid in ascorbic acid protection from degradation: a heterogeneous system for homogeneous thermodynamic data

International audienceA heterogeneous system between vitamin C and stearic acid was characterized by thermal and crystallographic analyses. The results showed that such a system prevents vitamin C from thermal decomposition. The evidence was provided by implementing a new protocol associating chromatic assays and thermal analyses in order to quantify the percentage of non-degraded vitamin C. The results collected with the vitamin C–stearic acid mixtures allowed deducing coherent interpretation of the results obtained with pure vitamin C at different heating scan rates. Vitamin C mainly degrades upon melting but also in the solid state for temperature close to the melting point when the heating rates are very low. Under these conditions, the temperature determined at the onset of the DSC graphs cannot be associated with the melting temperature but with a fusion-degradation phenomenon. At higher scan rates, the onset as well as the endothermic value of the signal increase to reach plateau values. These values have been identified as the temperature and enthalpy values of melting of vitamin C according to the results obtained from the heterogeneous system

Insights into the crystal structure, polymorphism and thermal behavior of menthol optical isomers and racemates

International audienceThe physico-chemical properties of the levo- and dextrorotatory menthol isomers as well as the corresponding racemic compound were studied using X-ray single-crystal or powder diffraction and differential scanning calorimetry experiments. As a result, the not yet determined crystal structure of DL-menthol was solved. Moreover, the stable and metastable experimental temperature-composition phase diagrams of the L-menthol/D-menthol binary system were determined. The thermodynamic relative stability of the different menthol polymorphs was also established. The present paper provides new physical, chemical and thermodynamic data of L-, D- and DL-menthol and offers new insight into their polymorphism as well as into the levorotatory-dextrorotatory menthol interactions. Both the thermodynamic and crystallographic approaches demonstrate unambiguously that racemic menthol is a racemate

Desarrollo y crecimiento del microcrédito en Colombia 2000- 2014 /

El presente artículo tiene como propósito analizar el crecimiento que ha experimentado el microcrédito en Colombia para el periodo comprendido entre los años 2000-2014 haciendo énfasis en su notoria presencia en los últimos años, analizando los factores que han permitido esta tendencia, determinando las incidencias de las ventajas de este producto en su propio crecimiento, contextualizando la situación actual del microcrédito en el país y visionando el comportamiento de este producto en el futuro.Incluye bibliografí

Comprehensive determination of the solid state stability of bethanechol chloride active pharmaceutical ingredient using combined analytical tools

International audienceThe use of an integrative analytical approach allowed us to establish the intrinsic solid state stability of bethanechol chloride (BC), an active pharmaceutical ingredient used in the treatment of urinary retention. First, the crystal structure of the monoclinic form has been described using single crystal X-ray diffraction studies. Second, thermal analyses revealed that the compound degrades upon melting, with an apparent melting temperature estimated to be 231 °C. No transition from the monoclinic to the orthorhombic form has been observed, suggesting that the monoclinic form is the stable one. Third, the two-step melting–decomposition process has been elucidated by liquid chromatography and thermogravimetry coupled to mass spectrometry. The first step corresponds to the sample liquefaction, which consists of the gradual dissolution of bethanechol chloride in its liquid degradant, i.e. betamethylcholine chloride. This step is in agreement with Bawn kinetics and the activation energy of the reaction has been estimated at 35.5 kcal mol−1. The second step occurs with accelerated degradation in the melt. Elucidation of secondary decomposition pathways evidenced autocatalytic properties conferred by the formation of both isocyanic acid and methyl chloride. Finally, dynamic water vapor sorption analysis showed a substantial hygroscopicity of the drug substance. A deliquescent point has been determined at 56% relative humidity at 25 °C

Preparation of parenteral nanocrystal suspensions of etoposide from the excipient free dry state of the drug to enhance in vivo antitumoral properties

Nanoparticle technology in cancer chemotherapy is a promising approach to enhance active ingredient pharmacology and pharmacodynamics. Indeed, drug nanoparticles display various assets such as extended blood lifespan, high drug loading and reduced cytotoxicity leading to better drug compliance. In this context, organic nanocrystal suspensions for pharmaceutical use have been developed in the past ten years. Nanocrystals offer new possibilities by combining the nanoformulation features with the properties of solid dispersed therapeutic ingredients including (i) high loading of the active ingredient, (ii) its bioavailability improvement, and (iii) reduced drug systemic cytotoxicity. However, surprisingly, no antitumoral drug has been marketed as a nanocrystal suspension until now. Etoposide, which is largely used as an anti-cancerous agent against testicular, ovarian, small cell lung, colon and breast cancer in its liquid dosage form, has been selected to develop injectable nanocrystal suspensions designed to be transferred to the clinic. The aim of the present work is to provide optimized formulations for nanostructured etoposide solutions and validate by means of in vitro and in vivo evaluations the efficiency of this multiphase system. Indeed, the etoposide formulated as a nanosuspension by a bottom-up approach showed higher blood life span, reduced tumor growth and higher tolerance in a murine carcinoma cancer model. The results obtained are promising for future clinical evaluation of these etoposide nanosuspensions

Degradação da vitamina C em um produto de manga (Mangifera indica L.) e lactisoro

This study aimed to determine the kinetics of vitamin C degradation in a product made from mango pulp (Mangifera indica L.) and whey protein powder, in order to determine the effect of temperature on its conservation and further evaluate the behavior of the L*, a*, b* and the total color difference (ΔE) in the powder product. Vitamin C was determined by the aoac 967.21/90 method using 2,6-dichlorophenol indophenol, and the color was quantified with a HunterLab Color Flex EZ colorimeter. Vitamin C showed greater stability in the powder product stored at 4 °C with a concentration at the end of the eighth sampling week of 13.94 ± 1.2 mg/10 0 g-1 sample and showing a first order degradation kinetics with k1 values of 0.014 and 0.041 mg/100 g/week at temperatures of 4 °C and 28 °C, respec-tively. The greatest variations in color occurred in samples stored at 28 °C, indicating the influence of the temperature change on the product compo-nents. In addition, L*, a* and b* parameters were less affected under storage temperature of 4 °C, and their values correspond to a second degree polynomial.Esta investigación buscó determinar la cinética de degradación de la vitamina C en un producto en polvo elaborado a base de pulpa de mango (Mangifera indica L. var. Hilacha) y lactosuero, con el fin de conocer el efecto de la temperatura en su conservación y además evaluar el comportamiento de los parámetros L*, a*, b* y la diferencia total del color (ΔE) en el producto. La vitamina C se determinó mediante el método aoac 967.21/90, con 2,6-diclorofenol indofenol; mientras que el color se cuantificó con un colorímetro Color Flex EZ marca HunterLab. La vitamina C exhibió mayor estabilidad en el producto en polvo almacenado a una temperatura de 4 °C, con una concentración (al término de la octava semana de muestreo) de 13,94 ± 1,2 mg/100 g por muestra, presentando una cinética de degradación de primer orden con valores de k1 de 0,014 y 0,041 mg/100 g/por semana para las temperaturas de 4 °C y 28 °C, respectivamente. Las mayores variaciones en el color se dieron en las muestras almacenadas a 28 °C, lo cual indica la influencia de la temperatura en el cambio de los componentes del producto. Los parámetros L*, a* y b* se vieron menos afectados a la temperatura de conservación de 4 °C y sus valores se ajustaron a un polinomio de segundo orden.Esta pesquisa procurou determinar a cinética de degradação da vitamina C em um produto em pó elaborado a base de polpa de manga (Mangifera indica L. var. Hilacha) e lactisoro, com o fim de conhecer o efeito da temperatura na sua conservação e ademais avaliar o comportamento dos parâmetros L*, a*, b* e a diferença total da cor (ΔE) no produto. A vitamina C determinou-se mediante o método aoac 967.21/90, com 2,6-diclorofenol indofe-nol; enquanto que a cor se quantificou com um colorímetro cor Flex EZ marca HunterLab. A vitamina C exibiu maior estabilidade no produto em pó armazenado a uma temperatura de 4 °C, com uma concentração (ao término da oitava semana de amostragem) de 13,94 ± 1,2 mg/100 g por amostra, presentando uma cinética de degra-dação de primeira ordem com valores de k1de 0,014 e 0,041 mg/100 g/por semana para as temperaturas de 4 °C e 28 °C, respectivamente. As maiores variações na cor deram-se nas amostras armazenadas a 28 °C, o qual indica a influência da temperatura na mudança dos componentes do produto. Os parâmetros L*, a* e b* viram-se menos afetados à temperatura de conservação de 4 °C e os seus valores se ajustaram a um polinômio de segunda ordem