Simultaneous quantification of delta-9-THC, THC-acid A, CBN and CBD in seized drugs using HPLC-DAD

An HPLC-DAD method for the quantitative analysis of Δ(9)-tetrahydrocannabinol (THC), Δ(9)-tetrahydrocannabinolic acid-A (THCA-A), cannabidiol (CBD), and cannabinol (CBN) in confiscated cannabis products has been developed, fully validated and applied to analyse seized cannabis products. For determination of the THC content of plant material, this method combines quantitation of THCA-A, which is the inactive precursor of THC, and free THC. Plant material was dried, homogenized and extracted with methanol by ultrasonication. Chromatographic separation was achieved with a Waters Alliance 2695 HPLC equipped with a Merck LiChrospher 60 RP-Select B (5μm) precolumn and a Merck LiChroCart 125-4 LiChrospher 60 RP-Select B (5μm) analytical column. Analytes were detected and quantified using a Waters 2996 photo diode array detector. This method has been accepted by the public authorities of Switzerland (Bundesamt für Gesundheit, Federal Office of Public Health), and has been used to analyse 9092 samples since 2000. Since no thermal decarboxylation of THCA-A occurs, the method is highly reproducible for different cannabis materials. Two calibration ranges are used, a lower one for THC, CBN and CBD, and a higher one for THCA-A, due to its dominant presence in fresh plant material. As provider of the Swiss proficiency test, the robustness of this method has been tested over several years, and homogeneity tests even in the low calibration range (1%) show high precision (RSD≤4.3%, except CBD) and accuracy (bias≤4.1%, except CBN).

Propiedades radiativas y ópticas de una herramienta de corte compuesta por nitruro de boro cúbico

Se ha medido la emisividad espectral (2,5-25 micras) normal de una herramienta de corte industrial, compuesta en un 55% por nitruro de boro cúbico (cBN), en el rango de temperaturas 200-1000 ºC. La emisividad medida muestra un comportamiento suavemente descendente al aumentar la longitud de onda, propio de metales, con un descenso pronunciado alrededor de 9 micras. Este valle se corresponde con la emisividad calculada para el cBN cúbico puro en la literatura, que sin embargo no exhibe el comportamiento metálico medido. Así mismo, se observa que la emisividad espectral es esencialmente independiente de la temperatura, aunque no así la emisividad total. Los resultados experimentales para el cBN puro indican que la reflectividad de dicho compuesto se puede explicar satisfactoriamente mediante un modelo de Lorentz para dieléctricos, mientras que el ajuste teórico de la reflectividad medida para la herramienta de corte necesita incluir una contribución del modelo de Drude para explicar el comportamiento metálico observado. Este modelo combinado se ajusta razonablemente bien a las medidas, y revela que la herramienta de corte se comporta como un semiconductor degenerado, con una alta densidad de portadores libres. Además, permite realizar una estimación teórica de sus constantes ópticas. Por último, se ha realizado un estudio sobre la medida y el control de la temperatura de la muestra, empleando distintos métodos de unión termopar.

Li_8SiN_4-Li_3N-BN体系中立方BN转化行为的研究

研究了高温高压下x·Li_8SiN_4-0.1(1-x)·Li_3N-0.9(1-x)·BN体系中立方氮化硼(cBN)的转化行为。Li_8SiN_4的存在可显著改善cBN晶体的发育,提高晶体质量。在4.2～5.5GPa,1340～1750℃范围内确定了x=4.8％时体系的cBN转化区,并对转化区内cBN转化率、平均生长速度、成核速度及破碎强度与转化温度和压力的关系进行了研究。

高温高压下立方氮化硼晶体的生长机制

在４．５～５．０ＧＰａ，１５００～１８００℃范围内，对在Ｌｉ基复合氮化物或氮硼化物的催化体系中以及其中添加Ｌｉ８ＳｉＮ４后合成ｃＢＮ进行了研究，探讨了ｃＢＮ晶体的表面构造和生长机制，研究了由六方氨化硼向立方氮化硼转变过程中硅的存在行为．本实验中合成的立方氮化硼为具有光泽的棕色透明单晶．

立方氮化硼的振动光谱及反射光谱的研究

将黑色、黄色、棕色三种小于50μm立方氮化硼粉末为样品,研究了其红外光谱、拉曼光谱、反射光谱,结果表明: (1)样品的红外光谱中,1818cm~(-1)和1548cm~(-1)属于cBN的晶格本征振动,而立方氮化硼的晶格本征振动外的晶体缺陷吸收则发生在～800cm~(-3),1580cm~(-1)～1740cm~(-1)和大于2400cm~(-1)处。 (2)拉曼光谱测试表明,在1052cm~(-1)和1304cm~(-1)附近出现的散射与cBN不具有反演中心及cBN具有立方结构这样的事实相一致,并且这种散射伴随着布里渊区中心声子的横向和纵向发射。144cm~(-1)附近出现的散射,被认为是由于局部振荡模式的出现,在反斯托克斯区造成的信号,这与晶格中杂质缺陷有关。 (3)依据得到的反射光谱,计算了cBN单晶禁带宽度,发现这三种cBN都具有大于金刚石的禁带宽度值,分别为:E_s(黑)=6.21eV,E_s(黄)=5.73eV,E_s(棕)=5.71eV。

Enabling ultra high precision on hard steels using surface defect machining

This paper is an extension to an idea coined during the 13th EUSPEN Conference (P6.23) named "surface defect machining" (SDM). The objective of this work was to demonstrate how a conventional CNC turret lathe can be used to obtain ultra high precision machined surface finish on hard steels without recourse to a sophisticated ultra precision machine tool. An AISI 4340 hard steel (69 HRC) workpiece was machined using a CBN cutting tool with and without SDM. Post-machining measurements by a Form Talysurf and a Scanning Electron Microscope (FEI Quanta 3D) revealed that SDM culminates to several key advantages (i) provides better quality of the machined surface integrity and offers (ii) lowering feed rate to 5μm/rev to obtain a machined surface roughness of 30 nm (optical quality).

Prediction of surface roughness during hard turning of AISI 4340 steel (69 HRC)

In this study, 39 sets of hard turning (HT) experimental trials were performed on a Mori-Seiki SL-25Y (4-axis) computer numerical controlled (CNC) lathe to study the effect of cutting parameters in influencing the machined surface roughness. In all the trials, AISI 4340 steel workpiece (hardened up to 69 HRC) was machined with a commercially available CBN insert (Warren Tooling Limited, UK) under dry conditions. The surface topography of the machined samples was examined by using a white light interferometer and a reconfirmation of measurement was done using a Form Talysurf. The machining outcome was used as an input to develop various regression models to predict the average machined surface roughness on this material. Three regression models - Multiple regression, Random Forest, and Quantile regression were applied to the experimental outcomes. To the best of the authors’ knowledge, this paper is the first to apply Random Forest or Quantile regression techniques to the machining domain. The performance of these models was compared to each other to ascertain how feed, depth of cut, and spindle speed affect surface roughness and finally to obtain a mathematical equation correlating these variables. It was concluded that the random forest regression model is a superior choice over multiple regression models for prediction of surface roughness during machining of AISI 4340 steel (69 HRC).

Parametric design optimization of hard turning of AISI 4340 steel (69 HRC)

Continuous research endeavors on hard turning (HT), both on machine tools and cutting tools, have made the previously reported daunting limits easily attainable in the modern scenario. This presents an opportunity for a systematic investigation on finding the current attainable limits of hard turning using a CNC turret lathe. Accordingly, this study aims to contribute to the existing literature by providing the latest experimental results of hard turning of AISI 4340 steel (69 HRC) using a CBN cutting tool. An orthogonal array was developed using a set of judiciously chosen cutting parameters. Subsequently, the longitudinal turning trials were carried out in accordance with a well-designed full factorial-based Taguchi matrix. The speculation indeed proved correct as a mirror finished optical quality machined surface (an average surface roughness value of 45 nm) was achieved by the conventional cutting method. Furthermore, Signal-to-noise (S/N) ratio analysis, Analysis of variance (ANOVA), and Multiple regression analysis were carried out on the experimental datasets to assert the dominance of each machining variable in dictating the machined surface roughness and to optimize the machining parameters. One of the key findings was that when feed rate during hard turning approaches very low (about 0.02mm/rev), it could alone be most significant (99.16%) parameter in influencing the machined surface roughness (Ra). This has, however also been shown that low feed rate results in high tool wear, so the selection of machining parameters for carrying out hard turning must be governed by a trade-off between the cost and quality considerations.

Determinantes socio-económicas de la desnutrición global infantil en la Localidad de Ciudad Bolívar (Bogotá, Colombia) en el año 2011

La desnutrición infantil y la pobreza se encuentran asociadas y estas a su vez con el progreso de los países. Conocer las determinantes sociales y económicas de la niñez que padece de bajo peso es necesario para crear escenarios propicios para el adecuado desarrollo de la primera infancia y de esta manera contribuir con la superación de la pobreza en el marco de sistemas sanitarios equitativos. Se realiza una descripción de las características socio-económicas y un análisis de posibles asociaciones entre estas y el bajo peso infantil de una muestra de infantes de uno de los sectores de mayor vulnerabilidad y pobreza de Bogotá (Colombia). La tasa del bajo peso infantil en la muestra del estudio en más alta a la presentada en Bogotá y Colombia (8.5%, 2.9% y 3.4% respectivamente). Al realizar el análisis de las posibles asociaciones entre el bajo peso y las variables de estudio, se evidencia que las relaciones son débiles entre la primera y las segundas, siendo la condición de desplazamiento la que mayor asociación positiva presenta con la deficiencia nutricional seguido del rango de edad entre los 25 y 36 meses. La situación que presenta mayor independencia con respecto al bajo peso infantil es contar con vivienda propia seguida del sexo. La desnutrición infantil se presenta en niveles importantes en sectores de mayor vulnerabilidad con implicaciones para el adecuado desarrollo de los infantes y para las intenciones de reducción de los índices de pobreza en el país. El fortalecimiento de las políticas públicas que favorezca el desarrollo infantil, la superación de la pobreza y las inequidades en los sistemas de salud deben contemplar acciones integrales dirigidas a los más vulnerables, con la participación de la sociedad civil y los sectores públicos y privados, el compromiso político y económico de los gobiernos y reglas claras que contribuyan a la solución estructural de la pobreza y que promueva el adecuado desarrollo infantil.

Variables condicionantes del éxito de los programas instruccionales para la mejora del ajuste personal y la adaptación escolar y social.

Detectar las características diferenciales de los escolares que mejor se beneficien de los programas instruccionales emotivos dirigidos a la mejora del ajuste personal y la adaptación escolar y social, así como aquellas otras características que pudieran provocar un efecto de estancamiento o, incluso empeoramiento. Investigación I: cuestionario a expertos, n: 40 psicólogos. Investigación II: muestra 1: 84 escolares de cuarto de EGB; muestra 2: 285 escolares de sexto de EGB; muestra 3: 143 escolares de octavo de EGB. Total: 512 escolares de EGB. Invest.I: respuestas experienciales dadas por psicólogos sobre aspectos favorecedores de buen pronóstico. Invest.II: Estudio 1: diseño intra e intergrupo con medidas repetidas pre y post tratamiento. Variable independiente, tratamiento. Variable dependiente, cambio en adaptación personal, escolar y social. Estudio 2: interrelación factorial del pretest, en contraste con la interrelación de los cambios operados después del tratamiento. Estudio 3: variables predictoras: edad, sexo, aptitudes técnicas y hábitos de estudio, rendimiento académico, adaptación y estilos educativos de los padres; variable criterio: cambio en la adaptación personal, escolar y social. Invest.I: Cuestionario a expertos sobre variables predictoras de un buen pronóstico. Invest.II: Test de inteligencia Lorge-Thorndike, no verbal; Banneb, EHE, PESA y ESDA, Hernández, 1983; Tamai, Hernández, 1983; EOTE y DEOTE, Hernández y García, 1985; FIS, CBS y CBN, Sección Departamental Psicología Educativa, Universidad de la Laguna. Invest. I: cómputo de respuestas y detección de coincidencias. Invest.II: Estudio 1: cuarto de EGB, ANOVA inter o intragrupo; sexto y octavo de EGB, análisis de las diferencias de medias antes-despues, T-test. Estudio 2: Correlación de Pearson. Estudio 3: Análisis de varianza; Oneway y análisis de la función discriminante; método RAO. 1. Los alumnos que más se benefician son los que expresaban mayores sentimientos de miedo, tristeza y autoculpa. Mostraban actitudes de choque con las normas y tendencia a aislarse. Sin embargo, no se detectaban dificultades en el estudio, gozando de mejores capacidades intelectivas, de menor edad y de unos padres menos restrictivos. 2. En los alumnos que empeoran se detecta un contraste entre su autoevaluación (expresan menos dificultades adaptativas) y otros criterios más externos (tendencia a sobrevalorarse, personas autosuficientes y conflictivas según sus compañeros, peor rendimiento intelectual y académico). 3. Los alumnos que se mantienen, parten de menores dificultades adaptativas y de estudio. La presente investigación nos permite realizar pronósticos diferenciales sobre qué personas pueden beneficiarse con este tipo de programas y para quienes, en cambio, no es eficaz. Nos proporciona información sobre las variables específicas sobre las que se debe incidir para optimizar los resultados.

Between the headlines of the Israeli - Arabic conflict: the coverage of CNN and Al Jazeera

The purpose of this article is to analyze the coverage made by CNN and Al Jazeera (in Arabic) to operation Caste Lead and the Goldstone Report during 2008 and 2009. This investigation is based in the theory of Qualitative Analysis of Content, by Wildemuth and Zhang. The methodology follows up with the one proposed by the authors in the main theory, complementing it with the Gamson and Modigliani´s Framing theory. The methodology mention above display the different in the coverage development, determined by the geopolitical influences; being CNN more influenced by a Western pro USA and pro Israeli speech, while Al Jazeera is more prone to support the Palestinian cause, this is the thesis of this article. During the development of the investigation, the thesis was demonstrated to be only partially accurate as CNN was not completely supportive to the Israeli arguments during the coverage, but Al Jazeera did have preferential speech for the Palestinian cause.

¿Es la concepción constructivista del Currículo Básico Nacional de Venezuela la alternativa para una enseñanza innovadora?

Resumen tomado del autor. Resumen en castellano e inglés. Notas a pie de página. Este artículo se incluye en el monográfico 'Didácticas específicas'

Cannabinol and cannabidiol exert opposing effects on rat feeding patterns

Rationale: Increased food consumption following Δ9- tetrahydrocannabinol-induced cannabinoid type 1 receptor agonism is well documented. However, possible non-Δ9- tetrahydrocannabinol phytocannabinoid-induced feeding effects have yet to be fully investigated. Therefore, we have assessed the effects of the individual phytocannabinoids, cannabigerol, cannabidiol and cannabinol, upon feeding behaviors. Methods: Adult male rats were treated (p.o.) with cannabigerol, cannabidiol, cannabinol or cannabinol plus the CB1R antagonist, SR141716A. Prior to treatment, rats were satiated and food intake recorded following drug administration. Data were analyzed for hourly intake and meal microstructure. Results: Cannabinol induced a CB1R-mediated increase in appetitive behaviors via significant reductions in the latency to feed and increases in consummatory behaviors via increases in meal 1 size and duration. Cannabinol also significantly increased the intake during hour 1 and total chow consumed during the test. Conversely, cannabidiol significantly reduced total chow consumption over the test period. Cannabigerol administration induced no changes to feeding behavior. Conclusion: This is the first time cannabinol has been shown to increase feeding. Therefore, cannabinol could, in the future, provide an alternative to the currently used and psychotropic Δ9-tetrahydrocannabinol-based medicines since cannabinol is currently considered to be non-psychotropic. Furthermore, cannabidiol reduced food intake in line with some existing reports, supporting the need for further mechanistic and behavioral work examining possible anti-obesity effects of cannabidiol.

Cassava bagasse cellulose nanofibrils reinforced thermoplastic cassava starch

Cellulose cassava bagasse nanofibrils (CBN) were directly extracted from a by-product of the cassava starch (CS) industry, viz. the cassava bagasse (CB), The morphological structure of the ensuing nanoparticles was investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), presence of other components such as sugars by high performance liquid chromatography (HPLC), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) experiments. The resulting nanofibrils display a relatively low crystallinity and were found to be around 2-11 nm thick and 360-1700 nm long. These nanofibrils were used as reinforcing nanoparticles in a thermoplastic cassava starch matrix plasticized using either glycerol or a mixture of glycerol/sorbitol (1:1) as plasticizer. Nanocomposite films were prepared by a melting process. The reinforcing effect of the filler evaluated by dynamical mechanical tests (DMA) and tensile tests was found to depend on the nature of the plasticizer employed. Thus, for the glycerol-plasticized matrix-based composites, it was limited especially due to additional plasticization by sugars originating from starch hydrolysis during the acid extraction. This effect was evidenced by the reduction of glass vitreous temperature of starch after the incorporation of nanofibrils in TPSG and by the increase of elongation at break in tensile test. On the other hand, for glycerol/sorbitol plasticized nanocomposites the transcrystallization of amylopectin in nanofibrils surface hindered good performances of CBN as reinforcing agent for thermoplastic cassava starch. The incorporation of cassava bagasse cellulose nanofibrils in the thermoplastic starch matrices has resulted in a decrease of its hydrophilic character especially for glycerol plasticized sample. (C) 2009 Elsevier Ltd. All rights reserved.

A rede de empresas voltada à viabilização de ações estratégicas de sustentabilidade em grandes bancos privados atuantes no Brasil

TEIXEIRA, Carlos Alberto Chagas. A rede de empresas voltada à viabilização de ações estratégicas de sustentabilidade em grandes bancos privados atuantes no Brasil. 2013. 159f. Dissertação (Mestrado em Administração)-Universidade Municipal de São Caetano do Sul, São Caetano do Sul, 2013.