bluuebunny/crossref_metadata_2025 huggingface dataset:
ESTIMATION OF SEASONAL VARIATIONS OF HARD COSMIC RAY FLUX AND ATMOSPHERIC PRESSURE IN 2004–2005
Authors: Styro Dmitrijus , Damauskaitė Jovita , Kleiza Jonas
Published: October 2010

This paper focuses on the analysis of connection between changes in hard cosmic ray flux (HCRF) and atmospheric pressure. To analyse connection between HCRF and atmospheric pressure change, the data of HCRF were obtained using a gamma spectrometer. The statistical data of measurements have been analysed. Detailed information on atmospheric pressure was presented by the Lithuanian Hydrometeorological Service. Correlation coefficients were calculated by performing a simple linear regression analysis between HCRF and atmospheric pressure in the same day. A strong inverse correlation during simultaneous measurements was determined. The correlation coefficients were defined for different seasons of the year. An empirical criterion of –20 imp/h was chosen in analysis of HCRF. Connection between HCRF decrease at 1.2–1.6 MeV energy interval and the minimum atmospheric pressure in 3–6 days at individual time intervals is defined in Vilnius. The efficiency of prognosis was 59–73% for the period 2004–2005. Santrauka Straipsnyje analizuojamas kietosios kosmines spinduliuotes srauto (KKSS) ir atmosferos slegio pokyčiu saryšis. KKSS buvo matuojamas gama spektrometru su scintiliaciniu jutikliu. Išsamia meteorologine informacija pateike Lietuvos hidrometeorologijos tarnyba. Koreliacijos koeficientai apskaičiuoti taikant tiesine regresija tarp KKSS ir atmosferos slegio pokyčiu. Nustatyta stipri atvirkštine koreliacija, kai matavimai atlikti ta pačia diena. Gauti skirtingi ivairiu metu sezonu koreliacijos koeficientai. Atliekant KKSS mažejimo analize buvo parinktas empirinis kriterijus –20 imp./h. Nustatytas saryšis tarp KKSS mažejimo 1,2–1,6 MeV energetiniame intervale ir atmosferos slegio mažejimo po 3–6 paru Vilniuje. KKSS mažejimas buvo analizuojamas per 8–9, 9–10, 11–12, 12–13 val. laiko intervalus. 2004–2005 m. atmosferos slegio mažejimo prognozes efektyvumas Vilniuje pagal KKSS mažejima buvo 59–73 %. Резюме Анализируется связь между изменениями потока жёсткого космического излучения (ПЖКИ) и атмосферного давления. ПЖКИ определялся с помощью гамма-спектрометра со сцинтилляционным детектором. Подробная метеорологическая информация была прегoставлена гидрометеорологической службой Литвы. Коэффициенты корреляции между колебаниями ПЖКИ и атмосферного давления были рассчитаны методом прямой регрессии. Установлена сильная обратная корреляция для тех случаев, когда измерения проводились одновременно. Значения коэффициентов корреляции оказались различными для разных сезонов года. При проведении анализа уменьшения ПЖКИ был выбран эмпирический критерий – 20 имп/час. Установлена прогностическая связь между уменьшением ПЖКИ в энергическом интервале 1,2–1,6 МэВ и уменьшением атмосферного давления через 3–6 суток в г. Вильнюсе. Уменьшение ПЖКИ рассматривалось в следующих временных интервалах: 8–9, 9–10, 11–12, 12–13 час. Эффективность прогноза уменьшения атмосферного давления в г. Вильнюсе по уменьшению ПЖКИ составила 59–73% в 2004–2005 гг.
Escalamiento de resultados de flotación de minerales a través de la función DTR
Authors: Magne L. , Jofré J. , Barría J. , Menacho J.
Published: October 2010

Se presenta una revisión de los principales modelos de distribución de tiempos de residencia, DTR, utilizables en flotación de minerales: modelos ideales de mezcla perfecta y flujo pistón, modelo de N reactores perfectos en serie y modelo combinado general de varias etapas. El que se utiliza más frecuentemente es el de N reactores imperfectos en serie, en el cual se atribuye una interpretación física invariante a los desplazamientos en tiempo e intensidad de la función DTR, pudiendo llevar a conclusiones erróneas respecto al régimen de mezcla y al cálculo de recuperación por flotación en planta. En este artículo se integra analíticamente la ecuación para escalar resultados de sistemas semicontinuos a planta industrial a través de la función DTR, empleando el modelo de mezcla imperfecta, y los modelos de García-Zúñiga y Klimpel para recuperación. Así, se logra una predicción más exacta del comportamiento de sistemas industriales a partir de información a menor escala, comparado con otros métodos.
Diagnosis de la defectología que de forma accidental suele presentar la laminación de tubería de altas prestaciones
Authors: Gutiérrez de Saiz-Solabarría S.
Published: October 2010

Se estudian las posibles causas que dan lugar a la defectología que, de forma accidental, suele presentarse en la laminación de tubería de altas prestaciones. En el presente trabajo se contemplan las calidades de acero de la norma API (American Petroleum Institute) en su especificación 5CT (1) para los grados C75-1 (acero al C-Mn aleado con Mo) y J55 (acero al C-Mn) y en su especificación 5L (2) para el grado A. Se caracteriza la tubería tanto química como metalúrgicamente, se diagnostican los defectos y se establecen conclusiones.
Modelización dinámica de molienda semiautógena basada en un modelo fenomenológico simplificado
Authors: Magne L. , Améstica R. , Barría J. , Menacho J.
Published: October 2010

Se presenta un modelo simplificado dinámico de molienda semiautogena, basado en consideraciones fenomenológicas. En dicho modelo se propone una ecuación para el transporte de pulpa a través del molino. La clasificación interna del molino se modela ajustándole una ecuación que depende del porcentaje de sólidos al interior del equipo. Se muestra la consistencia del modelo a través de resultados de una campaña experimental efectuada en un molino continuo de cascada de 1,83 m x 0,61 m (6 pies X 2 pies) (diámetro x longitud). En tal campaña se investigó el efecto del flujo de alimentación, granulometría y porcentaje de sólidos en la alimentación y la fracción de llenado de bolas sobre la respuesta metalúrgica del molino.
Adición de coque de petróleo a mezclas coquizables. Modificación de la calidad del coque metalúrgico
Authors: Menéndez J. A. , Pis J. J. , Díez M. A. , Barriocanal C. , Casal M. D. , Parra J. B. , Álvarez R.
Published: October 2010

Se estudia la influencia que la adición de un coque verde de petróleo a mezclas coquizables tiene sobre la calidad de los coques metalúrgicos resultantes. Se midieron propiedades mecánicas (ensayo IRSID), reactividad (ensayos CEE y NSC) y textura (porosidad y distribución del tamaño de poros). En general, la adición de coque de petróleo da lugar a una disminución de la porosidad de los coques obtenidos tanto a escala de laboratorio como semiindustrial. Dicha disminución se debe, en gran medida, a la disminución de microporos, lo cual contribuye a explicar la de la reactividad frente al CO2 de los coques metalúrgicos. Se desarrolla una metodología para la obtención y evaluación de las propiedades de coques metalúrgicos a escala de laboratorio, cuyos resultados se comparan con los obtenidos a escala semiindustrial.
Modelo estadístico en series temporales para la predicción de la temperatura de gas de tragante del horno alto
Authors: Martínez A. , Rieiro I. , Formoso A. , Cores A.
Published: October 2010

En el presente trabajo, a través de técnicas poco usadas en el campo siderúrgico, se establece un criterio para definir el comportamiento en el tiempo de variables de operación significativas del homo alto. Para ello, se ha desarrollado un modelo autorregresivo en series temporales que permite una adecuada predicción. La metodología ha consistido en utilizar las ecuaciones de Yule-Walker y el test de Akaike para establecer y elegir el mejor modelo, y el análisis de la función de autocorrelación para comprobarlo.
Estudio de la cinética de precipitación inducida mediante la determinación de los diagramas Precipitación-Tiempo-Temperatura (PTT) en aceros microaleados
Authors: Medina S. F.
Published: October 2010

Se describe un método desarrollado en el CENIM que permite estudiar la cinética de la precipitación inducida por la deformación en aceros microaleados. Mediante ensayos de torsión, se ha determinado la fracción recristalizada estáticamente de tres aceros microaleados con niobio, vanadio y titanio, respectivamente, a diferentes temperaturas y deformaciones. Cuando la precipitación comienza, la fracción recristalizada se desvía de la ecuación de Avrami y esto permite conocer el instante en el que la precipitación comienza (Ps) y el instante en que termina (Pf). De este modo, se pueden trazar las curvas de Precipitación-Tiempo-Temperatura (PTT) que muestran gráficamente la cinética de precipitación.
Respuesta electroquímica del cobre durante el fenómeno de corrosión por picaduras en soluciones con iones cloruro
Authors: García O. E. , Uruchurtu J. , Genescá J.
Published: October 2010

El cobre es un material frecuentemente empleado para la construcción de tuberías, sujeto a la acción de los cloruros, que ocasionan corrosión por picaduras. El presente trabajo busca determinar un posible mecanismo de corrosión por picaduras en el cobre por la acción de los cloruros, apoyándose en la información que ofrecen las técnicas electroquímicas de polarización, espectroscopia de impedancia faradaica y ruido electroquímico.
Tratamiento isotérmico de los aceros aleados al silicio Tipo SAE 92XX
Authors: Páez J. L. , Fuentes F. , Battagliese A.
Published: October 2010

La composición química de los aceros SAE 92XX es similar a la de la matriz metálica de una fundición esferoidal, por lo que se pensó en someter a un acero de ese tipo a tratamientos de austempering similares a los que se aplican para lograr una ADI (Austempered Ductile Iron), y verificar si se alcanzaban valores aceptables de plasticidad con elevados valores de resistencia a la tracción para el mismo acero, tal y como sucede con aquellas fundiciones, y comparar dichos resultados con los obtenidos en el mismo acero con tratamientos convencionales de temple y revenido. Se alcanzaron valores que demostraron que, por austempering, se logran excelentes valores de plasticidad, muy superiores a los alcanzados por temple y revenido para durezas del mismo orden.
Influencia de la microestructura en la fractura de aceros microaleados de forja
Authors: Romero J. L. , Linaza M. A. , San Martín J. I. , Rodríguez-Ibabe J. M. , Urcola J. J.
Published: October 2010

Se analiza la influencia de los tratamientos termomecánicos, en primer lugar, llevados a cabo en laboratorio y, posteriormente, en un proceso industrial, sobre las propiedades mecánicas de aceros microaleados de forja. Se han variado las temperaturas de forja y las velocidades de enfriamiento tras la misma y se ha estudiado su influencia sobre la resistencia y la tenacidad. La optimización de los tratamientos termomecánicos se ha realizado a nivel de laboratorio, probándose posteriormente las secuencias optimizadas a escala industrial. Las propiedades mecánicas se pueden explicar en términos de las microestructuras obtenidas en los diversos tratamientos termomecánicos. Así, microestructuras gruesas, obtenidas por enfriamientos lentos tras la deformación a elevadas temperaturas, muestran un comportamiento frágil. Se pueden obtener buenos valores de tenacidad, manteniendo la resistencia por afino de la microestructura, bien deformando el material a menores temperaturas de forja (ferrita+perlita finas) o enfriando aceleradamente tras la forja convencional (ferrita acicular).
Metalografía en color de los aceros inoxidables mediante la técnica de ataque coloreado
Authors: Fosca C. , Merino C. , Otero E. , Hierro P.
Published: October 2010

La metalografía en color mediante la técnica de ataque coloreado permite la identificación y cuantificación, por el contraste de color, de diversas fases y constituyentes presentes en la microestructura de un gran número de aleaciones. La técnica consiste en depositar una película de interferencia en la superficie del material como consecuencia de reacciones electroquímicas entre el metal y el reactivo de ataque coloreado. La aplicación de la técnica de ataque coloreado en los aceros inoxidables permite la identificación y cuantificación, mediante análisis de imagen, de fases secundarias como la ferrita en los aceros inoxidables austeníticos o la austenita secundaria y la fase sigma en los aceros inoxidables dúplex.
Conformado de aleaciones en estado semisólido. Aplicación a aleaciones hipereutécticas de Al-Si
Authors: Valer J. , Rodríguez J. M. , Urcola J. J.
Published: October 2010

Dentro de las nuevas tecnologías utilizadas para la producción de materiales, se encuentra el procesamiento de aleaciones en estado semisólido denominado, en sus distintas versiones, Rheocasting, Thixoforming, Thixoforging o Thixocasting. En este trabajo se describe el proceso, así como los fenómenos implicados en el mismo. Puesto que el conformado de aleaciones en estado semisólido requiere una preparación previa del material (para obtener una microestructura no dendrítica), se describe brevemente el proceso Osprey o Spray-forming, utilizado en este trabajo. Finalmente, se muestran los resultados microestructurales obtenidos mediante la combinación de estas dos tecnologías, en aleaciones hipereutécticas de Al-Si (Al-25%Si-5%Cu, Al-25%Si-5%Cu- 2%Mg y Al-30%Si-5%Cu) y su comparación con las microestructuras obtenidas en aleaciones similares procesadas por métodos convencionales.
Envejecimiento del aluminio anodizado insuficientemente sellado
Authors: López V. , Bautista A. , Otero E. , González J. A.
Published: October 2010

En este trabajo se estudiaron los diferentes grados de sellado de recubrimientos anódicos de aluminio obtenidos por inmersión en agua desionizada y en disoluciones de acetato y trietanolamina a 50 °C (temperatura muy inferior a la empleada en el sellado hidrotérmico tradicional). Para ello se emplearon los ensayos normalizados de absorción de la gota de colorante, inercia a la disolución acida y medida de la admitancia a 1 kHz y se realizaron medidas de espectroscopia de impedancia electroquímica (EIE). Se estudió, además, el efecto del envejecimiento en la atmósfera sobre los recubrimientos sellados en estas condiciones y el aumento de su grado de sellado que tiene lugar espontáneamente.
Propiedades de aleaciones Ag-Pd para usos odontológicos
Authors: Basualto J. , Barceló C. , Gaete A.
Published: October 2010

En la búsqueda de aleaciones para usos odontológicos, económicamente alternativas, se trabaja con tres aleaciones Ag-Pd complejas, del tipo Ag-Pd-Au-Cu-Otros, dos aleaciones experimentales y un producto comercial. Se determinan las propiedades mecánicas y químicas de estas aleaciones y se hace un análisis comparativo de los resultados. El costo, factor importante, se establece con relación a los materiales del producto comercial. Se determina la dureza Vickers de las aleaciones Ag-Pd con diversos tratamientos térmicos, lo que permite mostrar su versatilidad en cuanto a usos restauradores y clasificarlas según norma. Se determina su comportamiento electroquímico y la resistencia a la pigmentación, lo que permite comparar las tendencias exhibidas. Se concluye que las propiedades químicas son aceptables cuando se compara con aleaciones odontológicas de referencia. Se instalaron en boca aleaciones experimentales A1 y A2, hace más de un año, con resultados satisfactorios hasta ahora, lo que valida las predicciones de laboratorio.
Propuesta de un método de ordenador para resolver el ajuste a la ecuación de Zener-Hollomon (Garofalo)
Authors: Rieiro I. , Carsí M. , Peñalba F.
Published: October 2010

Se presenta un método de ordenador integrado, desarrollado por los autores, para resolver la ecuación de Zener-Hollomon. Este método resuelve el problema del ajuste de la ecuación de Zener-Hollomon para amplios rangos de tensión aplicada, velocidad de deformación y temperatura de trabajo, mediante la aplicación progresiva de tres tipos de algoritmos. En primer lugar, una regresión reiterada multivariante por planos, para obtener unos valores que serán considerados como iniciales para un segundo bloque de algoritmos, además de depurar la base experimental de datos. El segundo bloque de algoritmos realiza un ajuste por mínimos cuadrados no lineales usando una modificación del método de Gauss-Newton modificado. En tercer lugar se encadena un grupo de programas que permiten iterar a partir de la solución del programa no lineal acercándose (si es preciso) por líneas en R2 hasta alcanzar la solución óptima. Todo ello con un soporte de análisis estadístico de la bondad de cada paso, de los datos y los residuos y del ajuste final conseguido.
Estudio del comportamiento frente a la corrosión de las capas pasivas formadas sobre las aleaciones amorfas Fe-Gr-Ni-(Si, P, B)
Authors: López M. F. , Escudero M. L. , Vida E. , Pierna A. R. , Marzo F. F. , Lorenzo A.
Published: October 2010

La resistencia a la corrosión de las aleaciones amorfas Fe62Cr10Ni8X20 (X = P, B, Si) inmersas en HCl 0,01M se evaluó usando técnicas electroquímicas. Las técnicas de espectroscopia de fotoemisión de rayos X y espectroscopia Auger se emplearon para estudiar la composición de las capas pasivas, formadas en aire sobre la superficie de las aleaciones amorfas. Del estudio realizado se concluye que el mejor comportamiento frente a la corrosión viene dado por la aleación amorfa que contiene como metaloide Si. Esto es debido a que la capa pasiva de dicha aleación está formada principalmente de óxido de cromo, lo cual confiere una alta resistencia a la corrosión.
Simulación de la fluencia en caliente de un acero microaleado con un contenido medio de carbono. I parte. Aproximación teórica
Authors: Cabrera J. M. , Prado J. M.
Published: October 2010

En la presente revisión se plantean las ecuaciones constitutivas necesarias para efectuar la modelización de la fluencia en caliente de materiales metálicos y, en particular, de un acero microaleado (Véase la II parte de este trabajo). Se hace especial hincapié en la simulación de los fenómenos de restauración y recristalización dinámica. Las ecuaciones propuestas son de base física, no empírica, y el modelo resultante es relativamente sencillo de utilizar y de implementar en un análisis por métodos numéricos. El estudio no queda circunscrito al comportamiento a fluencia sino que es capaz de predecir el tamaño de grano final.
Efecto de la temperatura, basicidad, ciclo térmico y potencial oxidante en la formación de fases minerales en briquetas de mineral de hierro
Authors: Bedolla E. , Aguilar E. A. , León C. A.
Published: October 2010

Se estudió el efecto de las condiciones de sinterización tales como temperatura, basicidad, ciclo térmico y potencial oxidante en la formación de fases minerales en briquetas de mineral de hierro magnetítico. Se encontró que un alto potencial de oxígeno (aire) favorece la reacción de oxidación de magnetita a hematites y como consecuencia la formación de calcioferrita. La calcioferrita se incrementó con el aumento de la basicidad y disminuyó con el incremento de la temperatura. Para un potencial de oxígeno medio (ρO2 = 5 x 10-3 atm.), el aglomerado estuvo compuesto en su mayor parte por magnetita con pequeñas cantidades de hematites reoxidada y cantidades insignificantes de calcioferrita. Se observó que la magnetita se incrementa y la hematites disminuye con el aumento de la basicidad. Las fases minerales presentes en briquetas sinterizadas en la mezcla gaseosa de 1 % CO, 24 % CO2 y 75 % N2, incluyen la magnetita y fases altamente oxidadas como hematites y calcioferrita.
Simulación de la fluencia en caliente de un acero microaleado con un contenido medio de carbono. III parte. Ecuaciones constitutivas
Authors: Cabrera J. M. , Al Omar A. , Prado J. M.
Published: October 2010

Siguiendo el planteamiento teórico efectuado en la I parte de este trabajo, se determinaron las ecuaciones constitutivas del comportamiento a la deformación en caliente de un acero comercial microaleado con un contenido medio de carbono. Para este objetivo se emplearon los ensayos de compresión uniaxial en caliente ya descritos en la II parte, los cuales se efectuaron en un rango de cinco órdenes de magnitud en velocidad de deformación y 300 °C de temperatura. Se comparan los resultados experimentales con el modelo teórico introducido en la I parte y se verifica que el error es inferior al 10 %. Se comprobó que la clásica ecuación del seno hiperbólico podía describir con precisión el comportamiento observado siempre y cuando las tensiones se normalicen por el módulo de Young, las velocidades de deformación por el coeficiente de autodifusión de la austenita, y se considere un efecto adicional sobre la tensión cuando el tamaño de grano inicial sea suficientemente fino.
Mapping aquifer geometry using electrical resistivity tomography: a case study from Şanlıurfa, south‐eastern Turkey
Authors: Drahor M.G. , Berge M.A. , Göktürkler G. , Kurtulmuş T.Ö.
Published: October 2010

A shallow aquifer system was investigated with 2D electrical resistivity tomography (ERT) to determine the hydrogeological setting of the Balıklı Lake region, Şanlıurfa, Turkey. Many spring waters are found in the study area where groundwater flow paths merge and reach the surface. A recreation complex was planned near the Balıklı Lake by the Municipality of Şanlıurfa. Therefore, an ERT survey was carried out to reveal the subsurface characterization, particularly to investigate the possible shallow aquifer system beneath the recreation area. Consequently, 2D resistivity data along thirteen profiles were acquired in the study area and the data were inverted by a tomographic inversion technique. The conductive layers in the ERT results indicated a shallow aquifer zone probably related to a karstic environment. The high conductivity observed in this layer might be caused by pollution resulting from the industrial and domestic wastes of the residential areas. The high resistive bottom layer was considered to be the basement in the study area. The geometry of the shallow aquifer environment was confirmed by slicing maps obtained from the ERT data. To build the conceptual geological model, a 2D forward resistivity modelling study was also achieved after the inversion studies. The inversion parameters and borehole result underlie the background of the forward model. Field and synthetic data were compared to each other and tested in means of calculation of the misfits to determine the reliability of these models.
Recurrent cholangitis in the tropics
Authors: Jain PA , Gandhi VV , Desai P , Doctor NH
Published: October 2010

The development of biliary casts is very rare, especially in non-liver transplant patients. The etiology of these casts is uncertain but several factors have been proposed which lead to bile stasis and/or gallbladder hypo-contractility and promote cast formation. Here, we report a 54-year-old male, with diabetes and ischemic heart disease, who presented with recurrent attacks of cholangitis. Magnetic resonance cholangiopancreatography revealed linear T1 hyperintense and T2 hypointense filling defects in the right and left hepatic ducts extending into the common hepatic duct, and a calculus in the lower common bile duct, raising a suspicion of worm in the biliary tree. In view of failed attempts at extraction on endoscopy, patient underwent surgery. At exploration, biliary casts and stones were extracted from the proximal and the second order bile ducts, with the help of intraoperative choledochoscopy and a bilio-enteric anastomosis was accomplished. Although endoscopic retrieval of the biliary cast can be employed as first-line management, surgery should be considered in case it fails.
Identification of a novel mutation in an Indian patient with CAII deficiency syndrome
Authors: Shivaprasad C , Paliwal P , Khadgawat R , Sharma A
Published: October 2010

Carbonic anhydrase II (CAII) deficiency syndrome characterized by osteopetrosis (OP), renal tubular acidosis (RTA), and cerebral calcifications is caused by mutations in the carbonic anhydrase 2 (CA2) gene. Severity of this disorder varies depending on the nature of the mutation and its effect on the protein. We present here, the clinical and radiographic details along with, results of mutational analysis of the CA2 gene in an individual clinically diagnosed with renal tubular acidosis, osteopetrosis and mental retardation and his family members to establish genotype-phenotype correlation. A novel homozygous deletion mutation c.251delT was seen in the patient resulting in a frameshift and a premature stop codon at amino acid position 90 generating a truncated protein leading to a complete loss of function and a consequential deficiency of the enzyme making this a pathogenic mutation. Confirmation of clinical diagnosis by molecular methods is essential as the clinical features of the CAII deficiency syndrome are similar to other forms of OP but the treatment modalities are different. Genetic confirmation of the diagnosis at an early age leads to the timely institution of therapy improving the growth potential, reduces other complications like fractures, and aids in providing prenatal testing and genetic counseling to the parents planning a pregnancy.
Issues in pharmacotherapy of 2009 H1N1 influenza infection
Authors: Gupta YK , Padhy BM
Published: October 2010

The pandemic caused by the 2009 H1N1 influenza A virus has been a cause of great concern for healthcare professionals and the scientific community worldwide. Due to the widespread resistance of the virus to adamantanes, pharmacotherapy is currently limited to neuraminidase inhibitors, oseltamivir and zanamivir. The use of neuraminidase inhibitors in India is primarily associated with issues of patient and physician awareness, variability in disease management guidelines, safety and efficacy in the Indian population, need for active drug safety monitoring, and development of resistance due to possible misuse. In addition, other issues like availability of the drugs in retail and stockpiling by the public health authorities need careful introspection. The development of influenza vaccines in India and its adequate availability to the country's populace also poses significant challenges in the management of the pandemic. In light of the limited therapeutic options available for the management of the disease, research on novel targets and pharmacological agents would also be beneficial in addressing the challenges of future outbreaks.
Tardive oculogyric crisis associated with amisulpride monotherapy
Authors: Mendhekar DN , Lohia D , Kataria P
Published: October 2010

Oculogyric crisis (OGC) is a dystonic and distressing side- effect which occurs immediately after the administration of high-potency antipsychotic drugs and is usually reported as a subtype of dystonia. We report a case of a young woman with schizophrenia who presented with tardive OGC related to amisulpride.
Thymoquinone Attenuates Diethylnitrosamine Induction of Hepatic Carcinogenesis Through Antioxidant Signaling
Authors: Sayed-Ahmed Mohamed M. , Aleisa Abdulaziz M. , Al-Rejaie Salim S. , Al-Yahya Abdulaziz A. , Al-Shabanah Othman A. , Hafez Mohamed M. , Nagi Mahmoud N.
Published: October 2010

Hepatocellular carcinoma accounts for about 80–90% of all liver cancer and is the fourth most common cause of cancer mortality. Although there are many strategies for the treatment of liver cancer, chemoprevention seems to be the best strategy for lowering the incidence of this disease. Therefore, this study has been initiated to investigate whether thymoquinone (TQ), Nigella sativa derived‐compound with strong antioxidant properties, supplementation could prevent initiation of hepatocarcinogenesis‐induced by diethylnitrosamine (DENA), a potent initiator and hepatocarcinogen, in rats. Male Wistar albino rats were divided into four groups. Rats of Group 1 received a single intraperitoneal (I.P.) injection of normal saline. Animals in Group 2 were given TQ (4 mg/kg/day) in drinking water for 7 consecutive days. Rats of Group 3 were injected with a single dose of DENA (200 mg/kg, I.P.). Animals in Group 4 were received TQ and DENA. DENA significantly increased alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin, thiobarbituric acid reactive substances (TBARS) and total nitrate/nitrite (NOx) and decreased reduced glutathione (GSH), glutathione peroxidase (GSHPx), glutathione‐s‐transferase (GST) and catalase (CAT) activity in liver tissues. Moreover, DENA decreased gene expression of GSHPx, GST and CAT and caused severe histopathological lesions in liver tissue. Interestingly, TQ supplementation completely reversed the biochemical and histopathological changes induced by DENA to the control values. In conclusion, data from this study suggest that: (1) decreased mRNA expression of GSHPx, CAT and GST during DENA‐induced initiation of hepatic carcinogenesis, (2) TQ supplementation prevents the development of DENA‐induced initiation of liver cancer by decreasing oxidative stress and preserving both the activity and mRNA expression of antioxidant enzymes.
Insulin Resistance is an Independent Correlate of High Serum Levels of Advanced Glycation End Products (AGEs) and Low Testosterone in Non‐Diabetic Men
Authors: Tahara Nobuhiro , Imaizumi Tsutomu , Takeuchi Masayoshi , Yamagishi Sho-ichi
Published: October 2010

Advanced glycation end products (AGEs) are involved in cardiovascular disease. Low testosterone level is associated with increased risks of cardiometabolic disorders as well. However, which anthropometric and metabolic variables, including AGEs, are independently correlated with low testosterone is largely unknown. In this study, we investigated whether high serum level of AGEs is one of the independent determinants of low testosterone in non‐diabetic men. One hundred thirteen non‐diabetic men who did not receive any drugs for hypertension and dyslipidemia underwent a complete history and physical examination, determination of blood chemistries, including serum AGEs and testosterone. Univariate analysis showed that testosterone levels were associated with waist circumference (inversely), diastolic blood pressure (BP) (inversely), mean BP (inversely), triglycerides (inversely), HDL‐cholesterol, fasting plasma glucose (inversely), fasting insulin (inversely), homeostasis model assessment of insulin resistance (HOMA‐IR) (inversely), AGEs (inversely) and uric acid (inversely). By the use of multiple stepwise regression analyses, HOMA‐IR (p = 0.005) and triglycerides levels (p < 0.05) remained significant and were independently related to testosterone levels (R2 = 0.168). HOMA‐IR index was one of the independent determinants of serum levels of AGEs as well. The present study demonstrated for the first time that HOMA‐IR was independently associated with high serum levels of AGEs and low testosterone in non‐diabetic men. Insulin resistance could link elevation of AGEs to testosterone deficiency in non‐diabetic men.
Going Beyond Patterns: Involving Cognitive Analysis in the Learning of Collocations
Authors: LIU DILIN
Published: October 2010

Since the late 1980s, collocations have received increasing attention in applied linguistics, especially language teaching, as is evidenced by the many publications on the topic. These works fall roughly into two lines of research (a) those focusing on the identification and use of collocations (Benson, 1989; Hunston, 2002; Hunston & Francis, 2000; Smadja & McKeown, 1991; Wouden, 1997) and (b) those focusing on the learning and teaching of collocations, including the development of reference books and textbooks (Bahns & Eldaw, 1993; Benson, Benson, & Ilson, 1997; Crowther, Dignen, & Lea, 2002; Hill & Lewis, 2002; Keshavarz & Salimi, 2007; Lewis, 2000, 2002; McCarthy & O'Dell, 2005; Nesselhauf, 2003; O'Dell & McCarthy, 2008; Sun & Wang, 2003; Webb & Kagimoto, 2009). Although these publications have greatly enhanced our understanding of collocations and their role learning and teaching, a close look at them indicates a lack of critical examination of the definition and the nature of collocations and the way collocations are taught. This article aims to address the issue through (a) a close critical examination of the collocations in existing teaching or reference materials and the typical way they are taught and (b) a corpus‐based analysis of some representative collocations. On the basis of the examination and analysis, the article argues for a more effective pedagogical approach to collocations that involves corpus‐based cognitive analysis of collocations.
Research Digest: Tesol Topics in other Journals
Authors: MICHAEL‐LUNA SARA
Published: October 2010

This section presents brief synopses of empirical research and theoretical discussions in peer reviewed journals. The aim is to disseminate findings and perspectives in fields related to TESOL and to provide access to the diverse conversations among scholars in the field.
Learning Phrasal Verbs Through Conceptual Metaphors: A Case of Japanese EFL Learners
Authors: YASUDA SACHIKO
Published: October 2010

Recent research in cognitive linguistics has shown that idiomatic phrases are decomposable and analyzable and that the individual words in idiomatic phrases systematically contribute to the overall figurative interpretations. This cognitive linguistic view suggests that enhancing awareness of conceptual metaphors embedded in the individual words may help second language students to learn idioms. This study examined whether enhancing awareness of orientational metaphors of particles facilitates acquisition of phrasal verbs by Japanese English as a foreign language (EFL) students. The students in the control group learned a set of phrasal verbs through traditional instruction, whereas those in the experimental group received the same input through a cognitive linguistic approach. The students in both groups were then asked to fill in the missing adverbial particles of the phrasal verbs. Results showed that the students in the experimental group performed significantly better than those in the control group, implying that when the target idioms are not stored as a unit in learners' mental lexicon, learners who are aware of conceptual metaphors may rely on metaphorical thought to produce an appropriate adverbial particle. This highlights the implications that EFL learners need to be explicitly taught about the notion of orientational metaphors before they can actively comprehend and produce appropriate phrasal verbs.
Falling on Sensitive Ears? The Influence of Musical Ability on Extreme Raters' Judgments of L2 Pronunciation
Authors: ISAACS TALIA , TROFIMOVICH PAVEL
Published: October 2010

TESOL Quarterly invites readers to submit short reports and updates on their work. These summaries may address any areas of interest to Quarterly readers.
A Dynamic Metacognitive Systems Account of Chinese University Students' Knowledge About EFL Reading
Authors: ZHANG LAWRENCE JUN
Published: October 2010

Metacognition, conceptualized as a set of dynamic systems, has been recognized as an important area of academic and pedagogical inquiry in applied linguistics from both theoretical and practical perspectives. Nonetheless, literature on students' metacognition about EFL reading is still cursory, and that is particularly true as regards Chinese EFL students. In response to globalization, many students whose first language is Chinese have become transnationals and are pursuing academic studies in English. The current study focuses on these second language (L2) learners. By reporting findings from an interview study of 20 Chinese students' EFL reading experiences framed within a dynamic metacognitive systems perspective, it attempts to account for the learner behavior and thinking that are normally reported under the rubric of language learning strategy research, which has courted criticism recently. The results suggest that there is a strong relationship between metacognition and successful EFL reading comprehension, and that the successful and the less successful L2 students are different in the amount and the quality of the metacognitive knowledge they possess. These results are discussed for possible insights into research on such learners and the pedagogical practices of teachers working with them.
Occurrence of gas phase ammonia in the area of Beijing (China)
Authors: Ianniello A. , Spataro F. , Esposito G. , Allegrini I. , Rantica E. , Ancora M. P. , Hu M. , Zhu T.
Published: October 2010

Abstract. The atmospheric concentrations of gaseous ammonia have been measured during two field campaigns in the winter and in the summer of 2007 at Beijing (China). These measurements were carried out by means of diffusion annular denuders coated with phosphorous acid. The results were discussed from the standpoint of temporal and diurnal variations and meteorological effects. The daily average NH3 concentrations were in the range of 0.20–44.38 μg/m3 and showed regular temporal variations with higher concentrations during summer and with lower during winter. The temporal trends seemed to be largely affected by air temperature because of agricultural sources. No diurnal variability was observed for gaseous NH3 levels in both winter and summer seasons. The highest ammonia value of 105.67 μg/m3 was measured in the early morning during the summer period when stable atmospheric conditions occurred. The diurnal winter and summer trends of ammonia showed a weak dependence on the air temperature and they were affected nearly by wind direction suggesting regional and local source influences. Ammonia was also correlated with the atmospheric mixing in the boundary layer, and, with NOx, CO and PM2.5 air concentrations supporting the hypothesis that the traffic may be also an important source of ammonia in Beijing.
Influence of convection and aerosol pollution on ice cloud particle effective radius
Authors: Jiang J. H. , Su H. , Zhai C. , Massie S. T. , Schoeberl M. R. , Colarco P. R. , Platnick S. , Gu Y. , Liou K.-N.
Published: October 2010

Abstract. Satellite observations show that ice cloud effective radius (re) increases with ice water content (IWC) but decreases with aerosol optical thickness (AOT). Using least-squares fitting to the observed data, we obtain an analytical formula to describe the variations of re with IWC and AOT for several regions with distinct characteristics of re-IWC-AOT relationships. As IWC directly relates to convective strength and AOT represents aerosol loading, our empirical formula provides a means to quantify the relative roles of dynamics and aerosols in controlling re in different geographical regions, and to establish a framework for parameterization of aerosol effects on re in climate models.
Lower-thermospheric wind fluctuations measured with an FPI during pulsating aurora at Tromsø, Norway
Authors: Oyama S. , Shiokawa K. , Kurihara J. , Tsuda T. T. , Nozawa S. , Ogawa Y. , Otsuka Y. , Watkins B. J.
Published: October 2010

Abstract. Simultaneous observations were conducted with a Fabry-Perot Interferometer (FPI) at a wavelength of 557.7 nm, an all-sky camera at a wavelength of 557.7 nm, and the European Incoherent Scatter (EISCAT) UHF radar during the Dynamics and Energetics of the Lower Thermosphere in Aurora 2 (DELTA-2) campaign in January 2009. This paper concentrated on two events during periods of pulsating aurora. The lower-thermospheric wind velocity measured with the FPI showed obvious fluctuations in both vertical and horizontal components. Of particular interest is that the location of the fluctuations was found in a darker area that appeared within the pulsating aurora. During the same time period, the EISCAT radar observed sporadic enhancements in the F-region backscatter echo power, which suggests the presence of low-energy electron (1 keV or lower) precipitation coinciding with increase in amplitude of the electromagnetic wave (at the order of 10 Hz or higher). While we have not yet identified the dominant mechanism causing the fluctuations in FPI-derived wind velocity during the pulsating aurora, the frictional heating energy dissipated by the electric-field perturbations may be responsible for the increase in ionospheric thermal energy thus modifying the local wind dynamics in the lower thermosphere.
Social perceptions of floods and flood management in a Mediterranean area (Costa Brava, Spain)
Authors: Lara A. , Saurí D. , Ribas A. , Pavón D.
Published: October 2010

Abstract. Taking as an example three study cases in the Costa Brava area, this paper examines the social perception of floods through surveys, interviews and Focus Group sessions. Perception is then related to vulnerability, flood management, and citizen's preferences regarding alternatives to curb flood losses in the future. The study concludes that flood awareness and the willingness to take actions regarding this hazard are clearly related to the degree of social involvement with the affairs of the local community. Furthermore, participatory settings such as Focus Group sessions appear to enable a better environment for assessing and implementing flood management options that attempt to modify human activities rather than modify natural processes as has been frequently the case in the past.
Some possible correlations between electro-magnetic emission and seismic activity during West Bohemia 2008 earthquake swarm
Authors: Kolář P.
Published: October 2010

Abstract. A potential link between electromagnetic emission (EME) and seismic activity (SA) has been the subject of scientific speculations for a long time. EME versus SA relations obtained during the 2008 earthquake swarm which occurred in West Bohemia are presented. First, a brief characterisation of the seismic region and then the EME recording method and data analysis will be described. No simple direct link between EME and SA intensity was observed, nevertheless a deeper statistical analysis indicates: (i) slight increase of EME activity in the time interval 60 to 30 min before a seismic event with prevalent periods about 10 min, (ii) some gap in EME activity approximately 2 h after the event, and (iii) again a flat maximum about 4 h after the seismic events. These results qualitatively correspond with the observations from other seismically active regions (Fraser-Smith et al., 1990). The global decrease of EME activity correlating with the swarm activity decay was also observed. Due to the incomplete EME data and short observation time, these results are limited in reliability and are indicative only.
The Influence of Particle Size on the Mechanical Properties of Dental Glass Ionomer Cements
Authors: Brandt Björn , Lohbauer Ulrich , Göken Mathias , Durst Karsten
Published: October 2010

The toughening potential of a particle‐size reduction is investigated on experimental glass ionomer cements (GICs). A reduction of the particle size results in a reduced fracture toughness. The use of bimodal particle‐size distributions is proposed for the development of tough and workable cements, where small particles provide the reactive surface area and large particles are responsible for crack deflection. Characterization of a GIC‐restored tooth with reference to a composite restoration by nanoindentation demonstrates the clinical relevance of the study. The elastic properties of GICs are well adapted for application in contact with dentine.
Multi‐Gram Synthesis of a Hyaluronic Acid Subunit and Synthesis of Fully Protected Oligomers
Authors: Virlouvet Mickaël , Gartner Michael , Koroniak Katarzyna , Sleeman Jonathan P. , Bräse Stefan
Published: October 2010

Fully protected tetra‐, hexa‐ and octasaccharides of hyaluronic acid were synthesized on a scale of several 100 mg up to gram quantities using allyl (methyl 2‐O‐benzoyl‐3‐O‐benzyl‐4‐O‐levulinoyl‐β‐D‐glucopyranosyluronate)‐(1→3)‐4‐O‐acetyl‐6‐O‐benzyl‐2‐deoxy‐2‐trichloroacetamido‐β‐D‐glucopyranoside as a key building block. This disaccharide was subjected to deprotection, then glycosylation via the trichloroacetimidate method was employed to achieve the formation of the oligosaccharides.
Fully Enzymatic Peptide Synthesis using C‐Terminal tert‐Butyl Ester Interconversion
Authors: Nuijens Timo , Cusan Claudia , van Dooren Theodorus J. G. M. , Moody Harold M. , Merkx Remco , Kruijtzer John A. W. , Rijkers Dirk T. S. , Liskamp Rob M. J. , Quaedflieg Peter J. L. M.
Published: October 2010

Chemoenzymatic peptide synthesis is potentially the most cost‐efficient technology for the synthesis of short and medium‐sized peptides with some important advantages. For instance, stoichiometric amounts of expensive coupling reagents are not required and racemisation does not occur, thus rendering purification easier compared to chemical peptide synthesis. The economically most attractive synthesis runs in the N→C terminal direction wherein a cheap C‐terminally protected amino acid is employed as the building block for elongation. However, C‐terminal deprotection and activation after an elongation step – without cleavage of the side‐chain protective groups or the peptide bonds – was hitherto still a challenge. In this paper we describe a novel C‐terminal ester interconversion catalysed by the serine endopeptidase Alcalase. C‐Terminally protected peptide tert‐butyl esters were enzymatically converted into primary alkyl esters in quantitative yield and used directly in the next enzymatic elongation step with another amino acid tert‐butyl ester. This fully enzymatic N→C elongation strategy by C‐terminal ester interconversion was applied toward the synthesis of biologically active peptides up to the pentamer level.
An Efficient Synthesis of gem‐Dihydroperoxides with Molecular Oxygen and Anthracene under Light Irradiation
Authors: Tada Norihiro , Cui Lei , Okubo Hiroaki , Miura Tsuyoshi , Itoh Akichika
Published: October 2010

A new efficient dihydroperoxidation protocol of a wide variety of carbonyl compounds with molecular oxygen, anthracene, and 2‐propanol under light irradiation afforded their corresponding gem‐dihydroperoxides in high yields.
Asymmetric Synthesis of (R)‐3‐Hydroxy‐2‐methylpropanoate (‘Roche Ester’) and Derivatives via Biocatalytic CC‐Bond Reduction
Authors: Stueckler Clemens , Winkler Christoph K. , Bonnekessel Melanie , Faber Kurt
Published: October 2010

Enoate reductases from the ‘old yellow enzyme’ family were employed for the asymmetric bioreduction of methyl 2‐hydroxymethylacrylate and its O‐allyl, O‐benzyl and O‐TBDMS derivatives to furnish (R)‐configurated methyl 3‐hydroxy‐2‐methylpropionate products in up to >99% ee Variation of the O‐protective group had little influence on the stereoselectivity, but a major impact on the reaction rate.
Overcoming mass‐transfer limitations in partial hydrogenation of soybean oil using metal‐decorated polymeric membranes
Authors: Singh D. , Pfromm P. H. , Rezac M. E.
Published: October 2010

The conventional soybean oil hydrogenation process (metal catalyst on solid support particles slurried in oil, H2 bubbled through the oil) is compared with metal‐decorated integral‐asymmetric polyetherimide (PEI) membranes, as far as changes in temperature and pressure are concerned. Using metal‐decorated polymeric membranes, H2 is supplied to the catalytic sites by permeation from the membrane substructure. As opposed to the slurry process, metal‐decorated membranes show only slightly increased trans fatty acid (TFA) formation when the temperature is raised (50–90°C) to accelerate the process. This is likely due to the efficient and to some extent self‐regulating H2 supply directly to the catalytic sites on the membrane skin. The hydrogenation rate and TFA formation of the metal‐decorated membrane process show a minor dependence on pressure. © 2010 American Institute of Chemical Engineers AIChE J, 2011