bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Microscalpels for Removing Proximal Composite Resin Overhangs on Class II Restorations
Authors: Wolff D , Schick S , Staehle HJ , Frese C
Published: May 2017

Introduction:

Limited access to interdental spaces complicates removal of excess material when placing class II composite resin restorations. Evidence-based recommendations on interproximal finishing are rare. We present novel microscalpels for this indication. The aim of the study was to test their fracture strength and cutting ability and to compare microscalpels with the use of a scaler, oscillating devices (G5-ProShape, G5-Proxocare), finishing strips and scalpels of sizes 12, 15, and 21 in a standardized in vitro model.

Methods and Materials:

Fracture strength (LOAD) and cutting forces (CUT) of microscalpels were evaluated at different angles (15, 30, 60, and 75 degrees; n=30 each) in a universal testing machine. Devices were compared in vitro using standardized composite overhangs. Marginal quality (QUAL; n=30) and quantity of excess/deficit (QUAN; n=30) were evaluated using scanning electron microscopy (SEM) for each device (explorative data analysis, Student t-test or analysis of variance; post hoc Scheffé).

Results:

Microscalpels showed the highest LOAD (95.8 [5.0] N) (mean [standard deviation]) and easiest cutting (CUT) (7.6 [1.5]) at 15 degrees. At all angles, LOAD was significantly higher than CUT (p<0.001). Perfect margins were seen most often with scalpel size 12 (QUAL: 37% relative frequency), while most excess (73.4%) was observed with finishing strips. QUAN was lowest with microscalpels (19.3 [4.4] μm) and highest with finishing strips (116.0 [18.8]). Use of scalers led to fractures and crack formation.

Conclusion:

Microscalpels are able to cut composite at a lower force than necessary to fracture the blades at all angles. Small and/or curved scalpels yield the best-quality margins.
Enamel Mineral Content Changes After Bleaching With High and Low Hydrogen Peroxide Concentrations: Colorimetric Spectrophotometry and Total Reflection X-ray Fluorescence Analyses
Authors: Pinto AVD , Bridi EC , Amaral FLB , França FMG , Turssi CP , Pérez CA , Martinez EF , Flório FM , Basting RT
Published: May 2017

The purpose of this study was to evaluate the calcium (Ca) and phosphorous (P) content in enamel bleached with high and low concentrations of hydrogen peroxide (HP) using Total Reflection X-Ray Fluorescence (TXRF) and colorimetric spectrophotometry (SPEC). Forty-eight sound human third molars were used. Their roots were embedded in polystyrene resin and immersed for seven days in an artificial saliva solution. Then they were distributed into six groups to receive the bleaching treatments. The agents of high HP concentration (for in-office use) evaluated were Whiteness HP Maxx/FGM (35% HP), Whiteness HP Blue/FGM (35% HP, 2% calcium gluconate), Pola Office+/SDI (37.5% HP, 5% potassium nitrate), and Opalescence Boost/Ultradent (38% HP, 1.1% ion fluoride, 3% potassium nitrate); these agents were applied to enamel in three sessions. The agents of low HP concentration (for home use) evaluated were Pola Day/SDI (9.5% HP) and White Class 10%/FGM (10% HP, potassium nitrate, calcium, fluoride), and these agents were applied for 14 days. Enamel microbiopsies were evaluated by TXRF and SPEC analysis before the bleaching treatment (baseline), during the treatment, and 14 days after the end of the treatment. For TXRF, the Kruskal-Wallis test showed that Ca and P were not influenced by agent (p>0.05). For SPEC, Pola Office+, Opalescence Boost, Pola Day, and White Class 10% caused a decrease of Ca over time; there was a significant decrease of P over time to Pola Office+ and White Class 10%. The Spearman test showed no correlation between the Ca (p=0.987; r2=−0.020) and P (p=0.728, r2=0.038) obtained by SPEC and TXRF. For TXRF and SPEC, changes in Ca and P during bleaching occurred independently of the HP concentration used.
The Survival of Class V Composite Restorations and Analysis of Marginal Discoloration
Authors: Kim J-H , Cho J , Lee Y , Cho B-H
Published: May 2017

The aims of this retrospective clinical study were to analyze the longevity of class V composite restorations and compare the results obtained from clinical and laboratory evaluation of marginal discoloration. A total of 186 restorations were evaluated with modified US Public Health Service criteria. Longevity and associated variables were analyzed with the Kaplan-Meier method and a Cox proportional hazard model. Restorations with marginal discoloration were additionally evaluated using digital photographs and epoxy resin replicas under a stereomicroscope. The mean survival time was 15.0 years, with five- and 10-year survival rates of 95.5% and 83.1%, respectively. Z250 had a higher risk of failure (hazard ratio=7.01, 95% confidence interval=2.07-23.72) than Z100. In addition, the presence of occlusal wear facets and bleeding on probing were associated with an increased risk of failure of the restorations. However, the use of an adhesive system (Scotchbond Multi-Purpose or Clearfil SE Bond) did not affect the longevity of the restorations. The results of laboratory evaluation were significantly different from clinical evaluation (p<0.001, McNemar test). Among 55 restorations rated as Bravo in the clinical evaluation, 24 restorations (43.6%) were determined to have penetrating discoloration on laboratory evaluation. When evaluating aged composite restorations, surface refurbishment and the use of a microscope are recommended, which will be helpful in determining the need for timely repair or replacement.
Biber, H. (2013). Arquitectura y medio ambiente. Lima: Editorial Universidad Nacional Federico Villarreal
Authors: Caro Zaldivar Rosario
Published: May 2017

El Maestro Henry Biber Poillevard posee una amplia experiencia en el quehacer de la enseñanza - aprendizaje, lo cual le ha permitido ingresar en el análisis del tema de la Arquitectura y su relación con el Medio Ambiente, con muy buenos resultados.En principio, el hábitat creado por el ser humano y utilizado según su necesidad ha creado desequilibrios, pero el autor presenta en su publicación un estudio enfocado a la búsqueda del equilibrio en esa relación de hábitat y ambiente, en el que no solo es suficiente la aplicación de técnicas como única solución.El autor en su obra muestra un gran interés por el microclima en el que se sitúa su proyecto, por lo tanto, uno de sus principales objetivos se centra en abordar esta asociación con lo cual busca mostrar que la arquitectura se encuentra vinculada con el contextoAlgo importante en los aportes de su estudio, es que los grandes maestros mencionados y que participaron en su formación universitaria, le inculcaron una permanente revisión y profundización de los conocimientos. A su vez el mismo ha continuado ese camino, fomentando lo mismo en todos aquellos que fuimos sus alumnos.El arquitecto Biber presenta un análisis que marca con claridad la relación del Medio Físico - Ambiental y la obra arquitectónica, desde la relación del comportamiento humano así como los materiales y sistemas empleados en la resultante arquitectónica.
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Authors: Magnussen Ida Elise
Published: May 2017

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La ecuación de Gauss y el indicador Oraqi para simulación de la calidad del aire durante la emisión de gases de combustión de un caldero
Authors: Terry Calderón Víctor , Adrianzen Matienzo Elba , Bengoa Gaby , Flores María Teresa
Published: May 2017

Para el presente trabajo se consideró los siguientes datos de una planta pesquera, cuyas emisiones gaseosas proceden de un caldero Cleaver Broke: ( CO): 0,045kg/s; (SO2) : 0,010 kg/s y (NOx) : 0,006 kg /s, consignándose la altura de la chimenea (H ):15 m, la velocidad del viento ( u): 1,62 m/s, la temperatura de los gases de chimenea (To) : 623 ºK, la temperatura del medio en 291 ºK, y para efectos del cálculo, se consideró a la atmósfera en forma estable. Las emisiones de material particulado MP10 y de hidrocarburos alifáticos CnH2n+2 se calcularon mediante lo indicadores de la tabla 1. Con todos estos datos se procedió a realizar la simulación de la dispersión de estas emisiones, a fin de determinar valores de inmisión. Se utilizó la ecuación de Gauss y sus parámetros respectivos, dando como resultado que la mayor concentración de estos gases contaminantes se localiza a 0,60 km del punto fijo de emisión.Con ese resultado se procedió a aplicar la ecuación de ORAQI, determinándose que los valores de inmisión encontrados a esa distancia no afectan la calidad del aire, pues el indicador de calidad del aire (I.C.A), da como valor 96,7%, con lo cual la actividad del caldero y sus emisiones no dañan en forma traumática al entorno. Como podrá apreciarse este método permite predecir la calidad del aire conociendo las emisiones de un caldero. Por lo cual, se convierte en una herramienta importante para los Estudios de Impacto Ambiental (EIA).Palabras claves: Gauss, ORAQI, emisiones gaseosas, simulación
Riesgo Suicida, Depresión y Personalidad en estudiantes de Psicología con y sin Dificultad Vocacional de una Universidad de Lima
Authors: De la Cruz Valdiviano Carlos
Published: May 2017

La presente investigación fue de un diseño no experimental descriptivo y comparativo de dos grupos de estudiantes con (46 sujetos) y sin dificultad vocacional (46 sujetos) que fueron evaluados con el Psicodiagnóstico de Rorschach (Sistema Comprehensivo de Exner). Los resultados indican que dentro de las características generales de personalidad existe una mayor distorsión del pensamiento (intelectualización), actitudes de dominio y autoafirmación en el grupo con dificultad vocacional (p<0,05); en donde, cualitativamente, destaca infantilismo psíquico. En indicadores de constelación de suicidio (S-Con) y niveles de riesgo suicida no registran diferencias significativas; el grupo con dificultad vocacional, cualitativamente, expresa pensamientos destructivos y características disfóricas predominantes. En DEPI y en niveles de depresión, revelan presencia similar de depresión leve (28,3%), rasgos depresivos (13%) y trastorno significativo (6,6%) sin diferencias significativas, reflejando autocrítica negativa en el grupo con dificultad vocacional asociada con contenidos mórbidos (MOR>3), inadecuación interpersonal y sentido crítico negativo. Específicamente, en el grupo con dificultad vocacional, se halló diferencias significativas (p<0,05) en indicadores según Cluster de acuerdo al subgrupo sin y con apoyo psicológico. Existiendo, en el primero, mayores interferencias emocionales e inmadurez para el ejercicio profesional en el futuro.Palabras clave: Conducta suicida, depresión, estudiante de psicología, dificultad vocacional, Psicodiagnóstico de Rorschach
Influencia climatológica en el comportamiento de taxones de moluscos fluviales y terrestres, Villa Clara-Cuba
Authors: Fimia Duarte Rigoberto , Argota Pérez George , Osés Rodríguez Ricardo , Cepero Rodríguez Omelio , González González Ramón
Published: May 2017

El objetivo de esta investigación fue determinar posibles impactos de variables climatológicas sobre la reproducción y supervivencia de taxones de moluscos fluviales y terrestres en la provincia Villa Clara, Cuba. Para ello el estudio se realizó en los trece municipios de la provincia entre los años 2012 y 2013. Fueron recogidos los datos de registros en archivos pertenecientes al Centro Provincial de Vigilancia y Lucha Antiventorial provincial referidos a diferentes taxones de moluscos fluviales y terrestres. En cuanto a las variables climatológicas se analizaron: humedad relativa media, humedad relativa mínima, humedad relativa máxima, precipitación, temperatura máxima, temperatura mínima y temperatura media, las cuales se midieron en el Centro Meteorológico Provincial. Se observó que las variables climáticas de mayor influencia sobre el desarrollo y reproducción fueron la humedad relativa media y temperatura media respectivamente. Los taxones fluviales y terrestres con mayor representatividad fueron la Tarebia granifera, Praticorella griseola y Pomacea poeyana, mientras que los municipios con mayor presencia fueron Placetas, Santa Clara, Encrucijada y Camajuaní respectivamente. Se concluyó que es necesario incrementar medidas de control para las especies de moluscos fluviales y terrestres identificadas, dada su epidemiología en la transmisión de enfermedades zoonóticas.Palabras clave: variables climatológicas, reproducción, supervivencia, taxones, moluscos fluviales y terrestres, Villa Clara, Cuba
Demanda social y mercado ocupacional de carreras profesionales, Facultad de Medicina “Hipólito Unanue” Universidad Nacional Federico Villarreal
Authors: Viaña Pérez José María , Bello Vidal Catalina , Añaños Castilla Dante , Seminario Rivas Ruth
Published: May 2017

La función profesional, producto de la formación universitaria, se caracteriza por un saber y un hacer específicos que permite su inserción en el mercado ocupacional. La actividad profesional nace, se desarrolla, perfecciona o desaparece en el devenir histórico, condición que se encuentra vinculada a la demanda social. El objetivo fue determinar cómo se relaciona la demanda social y el mercado ocupacional de las carreras profesionales de medicina y enfermería. El estudio fue descriptivo, con una muestra de 203 sujetos entre estudiantes, egresados de la Facultad de Medicina “Hipólito Unanue” y funcionarios de establecimientos de salud. Se aplicaron dos instrumentos con una confiabilidad Alfa de Cronbach 77% y 78% respectivamente. La edad promedio de los estudiantes fue 24±2.6, egresados 34±8.3 y funcionarios 54±8 años. Un 80% de egresados reconoce que tuvo una formación según las necesidades del país, y 96% admite que el internado fue muy importante en su formación. El 90% afirmó que su profesión es más rentable en el extranjero que en el Perú y no hubo diferencias entre ambos grupos (p>0.05). Los funcionarios reconocen destreza profesional en nuestros egresados. En la carrera de medicina se evidencia una gran demanda de vacantes, pero limitada oferta institucional; solo ingresaron en los últimos siete años entre el 5% al 9% de postulantes, en comparación con otras carreras de la salud, lo que evidencia diferencias estadísticamente significativas (p<o,oo1). Se concluye que la demanda social para los egresados de las carreras profesionales de medicina y enfermería desde la percepción de funcionarios y egresados es muy alta, dentro y fuera del país por tratarse de personal altamente capacitado.Palabras clave: demanda social, mercado ocupacional, estudiante, egresado, funcionario
Riesgo de caries dental en pacientes de tres a seis años que acuden a la clínica de la de la Universidad Nacional Federico Villarreal
Authors: Peltroche Nimia O. , Gabrielli Enrique , Vásquez Miriam , Castro Antonieta
Published: May 2017

El objetivo del presente estudio fue determinar el riesgo de caries dental que presentan los pacientes de tres a seis años que acudieron a la clínica de la Universidad Nacional Federico Villarreal en el año 2011. La muestra fue de 50 niños de ambos sexos que cumplieron con los criterios de inclusión y exclusión, a quienes se les realizó una encuesta y una evaluación del índice de higiene oral para determinar la presencia y nivel de riesgo de caries dental. Los resultados obtenidos fueron que en los factores de riesgo de caries dental estudiados en la presente investigación están presentes indistintamente la edad y el sexo. El factor de riesgo más prevalente es el cepillado dental con 21 casos, seguido del factor visita al odontólogo con 19 casos. El riesgo de caries dental más prevalente es el “Riesgo Bajo” con un 40.8%, seguido de 37.6% con un “Riesgo Mediano” y 21.8% presentan “Riesgo Alto”. Al relacionar los valores se determinó que no hay diferencias significativas de los factores de riesgo de caries dental en relación al sexo, encontrándose diferencias altamente significativas entre los niveles de caries dental y la presencia de los factores de riesgo.Palabras claves: caries dental, riesgo, factores de riesgo
Evaluación de la toxicidad letal media por exposición a cianuro libre en efluentes y relaves mineros utilizando los biomodelos Brachydanio erio Y Eisenia andrei
Authors: Argota Pérez George , Espinoza Flores Nancy , Iannacone Oliver José
Published: May 2017

El objetivo del presente trabajo fue evaluar la toxicidad letal media por exposición a cianuro libre en efluentes y relaves mineros. El estudio se realizó durante el período poca lluvia, donde fueron seleccionadas cuatro muestras representativas de efluentes, así como relaves mineros, estableciéndose tres réplicas por cada muestra ambiental para el análisis. Para la determinación de la toxicidad letal media, fueron ensayos cuatro tratamientos de dilución más un tratamiento control, así como determinadas bajo condiciones experimentales según recomendaciones de la Comunidad Económica para la Cooperación y el Desarrollo, la utilización de Brachydanio rerio y Eisenia andrei como biomodelos. Se observó, una mortalidad del 100% de los individuos de Brachydanio rerio a las 24 horas de duración del ensayo, cuya concentración letal media correspondió a 0.078mg/L-1, mientras que en Eisenia andrei la concentración letal media ocurrió a las 48 horas de duración del ensayo y correspondió a 0.016g de relave. Se concluyó que los bioensayos indicaron efectos de toxicidad inmediata en efluentes y relaves mineros expuestos a cianuro libre.Palabras clave: toxicidad letal media, exposición, cianuro libre, efluentes y relaves mineros, Brachydario rerio, Eisenia andrei, Puno-Perú.
CIGRE/CIRED JWG C4.112 – Power Quality Monitoring
Authors: M. H. J. Bollen  , J.V. Milanović  , N. Čukalevski
Published: May 2017

In a response to the renewed interest in power quality monitoring and recognising cross-boundary relevance of power quality monitoring, CIGRÉ Study Committee C4 and CIRED established, in late 2010, the Join Working Group (JWG) C4.112: “Guidelines for Power quality monitoring – measurement locations, processing and presentation of data”. The JWG started work in February 2011 with the aim to address the application aspects of power-quality monitoring, in particular what to measure, how to measure and how to handle recorded data. This paper presents some of the results of the JWG achieved between February 2011 and December 2013, provides recommendations with respect to power quality monitoring depending on identified objectives of monitoring and identifies the areas requiring further development and research in order to comprehensively address the issue of power quality monitoring in contemporary and future power networks.
Implementation of an Optimal Energy Management within Islanded Microgrid
Authors: M. Marzband  , A. Sumper
Published: May 2017

This paper proposes an optimal Energy Management System (EMS) based on Mixed Integer Linear Programming (MILP) optimization technique for an islanded Microgrid (MG). A local energy market (LEM) platform is employed which attempts to obtain the best electricity market price and to maximize the utilization of existing distributed energy resources. Besides, a single side auction market structure is used for the LEM which takes the offer prices from all microsources to calculate market clearing price. Simulation and experimental results from the proposed method over a real MG are compared with those from a Modified Conventional EMS (MCEMS). The proposed algorithm is flexible, extendable and too fast to be utilized for different MG structures with various capacities. The results demonstrate the effectiveness of the proposed method to solve the optimal operation problem in an isolated MG with 25% reduction in the cost of operation.
Simulation of a small-scale electricity generation system from biomass gasification
Authors: V. Depoorter1  , P. Olivella-Rosell  , A. Sudrià-Andreu  , Jordi Giral-Guardia  , A. Sumper
Published: May 2017

The following work has been developed in the scope of the cooperation project called Pôle Goundi. This project, coordinated by the NGO Misión y Desarrollo para Goundi, with the collaboration of the technology transfer centre CITCEA-UPC and the support of the CCD-UPC, aims to electrify Goundi, a village located in the South of Chad. In this sense, the construction of a small-scale biomass gasification power plant is planned. Since the installation of the power plant will be done by stages, the first step is to demonstrate its viability by installing and operating the first 20kW of electrical power. For this, a complete commercial solution, mainly consisting of a multi-stage gasifier, an internal combustion engine and a synchronous generator, has been selected. Then, it has been modelled with Cycle-Tempo® and Matlab® simulation tools in order to analyze its operating parameters and performance. After a brief introduction about the aims and the scope of the project, this paper will proceed with a more detailed description of the system and the model and it will present some of the obtained results.
Wind Tunnel Experiments on Vertical-Axis Wind Turbines with Straight Blades
Authors: H. Dumitrescu  , A. Dumitrache  , C. L. Popescu  , M. O. Popescu  , F. Frunzulică  , A. Crăciunescu
Published: May 2017

This paper gives the experimental performances obtained in a wind tunnel for a flexible experimental model of vertical axis wind turbine (VAWT) with straight blades. The effects of blades arrangement in one or two stages, of setting angle and of blade numbers influences on the output performance were analysed. The results showed that the VAWT developed torque at low speeds is greater when the setting angle of blades is greater but the VAWT developed torque at higher speeds is greater when the setting angles of blades is less.
Design of Fast Real Time Controller for the SSSC Based on Takagi-Sugeno (TS) Adaptive Neuro-Fuzzy Control System
Authors: Mohammed Y. Suliman  , M. E. Farrag  , Sinan Bashi
Published: May 2017

FACTS (Flexible AC Transmission Systems) technology is one aspect of the power electronics revolution that is taking place in all areas of electric energy. The power transfer capability of a transmission line can be enhanced by using power electronics based system like FACTS that offer high speed and reliable control capability. The Static Synchronous Series Compensator (SSSC) is the second generation of the FACTS controller, which is used to control the power flow in the transmission line. In this paper, a new scheme to control SSSC using adaptive neuro fuzzy logic is proposed, in this controller, Takagi-Sugeno fuzzy rules are trained using off-line neuro fuzzy system, also, instantaneous power theory is used to calculate the power system parameters due to its high accuracy and less computation. The simulation and practical results show that real time application of the proposed controller is possible and robust compared to conventional controllers previously investigated. The experiment results obtained using the dSPACE data acquisition system and Matlab real time toolbox.
State and Space Vectors - Complementary Description of the 2-level VSI
Authors: J. Iwaszkiewicz  , L. Wolski
Published: May 2017

The paper deals with a generalized description system of the two level inverter. Two methods of mathematical approach to the representation of the converter’s state are presented and discussed. One method is standard space vector and the other, originally designed by authors, is state vector representation. The notational system provides a general simplification and standardization of vectors identification. It contains a novel handy proposal of notation and marking which is useful for converter description. The notation system permits to accomplish a comparison and correlation between space and state vectors. It describes state and space vectors by use of the same numbers. Thanks to these properties the proponed mathematical tool can be extremely useful in designing the control algorithms for easy implementation and fast performance of the converter
Blessures liées à une chute chez les aînés canadiens entre 2005 et 2013 : une analyse de l’Enquête sur la santé dans les collectivités
canadiennes
Authors: Do M. T. , Chang V. C. , Kuran N. , Thompson W.
Published: May 2017

Introduction

Nous décrivons l’épidémiologie et les tendances des blessures liées à une chute chez les aînés canadiens de 65 ans et plus selon le sexe et l’âge, ainsi que les
circonstances et les conséquences de ces blessures.

Méthodolgie

Nous avons utilisé des données représentatives tirées des échantillons de 2005, de 2009-2010 et de 2013 de l’Enquête sur la santé dans les collectivités canadiennes
afin de calculer le nombre et les taux de blessures liées à une chute pour chaque année d’enquête. Nous avons combiné, dans la mesure du possible, les données d’au moins deux
échantillons afin d’estimer la proportion de blessures liées à une chute par type de blessure, partie du corps affectée, type d’activité et type de traitement.

Résultats

Le taux de blessures liées à une chute chez les aînés est passé de 49,4 à 58,8 pour 1 000 personnes entre 2005 et 2013, période durant laquelle le nombre de blessures
liées à une chute a de façon générale augmenté de 54 %. Les femmes ont présenté des taux plus élevés que les hommes pour toutes les années d’enquête, ces taux augmentant avec l’âge.
La tendance à la hausse dans les taux de blessures liées à une chute était plus marquée chez les femmes et les plus jeunes. Les cassures et les fractures (37 %) ont été les
blessures les plus courantes, et l’épaule et le bras (16 %) ont été les parties du corps les plus couramment affectées. Plusieurs blessures liées à une chute se sont produites alors
que la personne marchait sur une surface non enneigée ou glacée (45 %). Plus de 70 % des aînés qui ont cherché à obtenir des soins médicaux pour leur blessure se sont rendus au
service d’urgence d’un hôpital.

Conclusion

Compte tenu de l’augmentation du nombre et des taux de blessures liées à une chute au fil du temps, la surveillance des tendances et des profils de ces dernières
demeure nécessaire.
Circulating Hormone Levels in Hatchlings of Green Turtle, Chelonia mydas, from Ras Al-Hadd Reserve, Oman
Authors: AlKindi A. Y. A.
Published: May 2017

Post-hatching levels of plasma estradiol (E2), Progesterone (Pro), testosterone (T), Luteinizing Hormone (LH), Follicle-Stimulating Hormone (FSH) and thyroxine (T4) were monitored in hatchlings of Green Turtle, Chelonia mydas immediately after emergence. Eggs were collected at random from 5 nests. The eggs were placed in incubators 16 hr after oviposition set at 26-27oC for male producing hatchlings and at 30-31oC for female producing hatchlings. Blood was collected after sacrifice. Chemiluminescence immunoassay was used for determination of plasma hormone levels, using Beckman Coulter Access-2-immunoassay and reagents (Beckman Coulter, Inc.). Sex was determined from histological examination of gonads. In males, plasma T levels were positively correlated with temperature (rho = 0.67, P<0.001). However, plasma E2 levels were negatively correlated but not strongly with temperature (rho = -0.396, P<0.05) and there was a weak correlation between plasma LH levels and temperatures (rho = 0.38, P<0.05). Also in the males, there was no correlation between temperature and either plasma Pro or T4 levels.  In females, there was no correlation between temperature and any of the hormones. In addition, there was no significant difference in plasma concentrations of T, Pro, LH or T4 between sexes. However, plasma E2 concentrationwas significantly higher in males (P<0.05). FSH was undetectable in plasma from both sexes. The significance of these findings will be discussed.
The Conditional Fault-Diameter of the K-ary n-Cube
Authors: Day Khaled , Touzene Abderezak
Published: May 2017

We obtain the conditional fault diameter of the k-ary n-cube interconnection network. It has been previously shown that under the condition of forbidden faulty sets (i.e. assuming each non-faulty node has at least one non-faulty neighbor), the k-ary n-cube, whose connectivity is 2n, can tolerate up to 4n-3 faulty nodes without becoming disconnected. We extend this result by showing that the conditional fault-diameter of the k-ary n-cube is equal to the fault-free diameter plus two. This means that if there are at most 4n-3 faulty nodes in the k-ary n-cube and if every non-faulty node has at least one non-faulty neighbor, then there exists a fault-free path of length at most the diameter plus two between any two non faulty nodes. We also show how to construct these fault-free paths. With this result the k-ary n-cube joins a group of interconnection networks (including the hypercube and the star-graph) whose conditional fault diameter has been shown to be only two units over the fault-free diameter.
Evaluation of Seminal Fluid Parameters, Reproductive Hormones and Testicular Biopsy for non-obstructive Azoospermic Patients with Sertoli cell only Syndrome
Authors: Qhraman Naso S. , Fakhrildin Muhammad-Baqir M-R. , Bra Dhaher H.
Published: May 2017

The aims of this study were (i) to determine the seminal fluid parameters, levels of serum reproductive hormones, testicular size and diameter of seminiferous tubules depending on multiple testicular biopsies from non-obstructive azoospermic (NOA) patients, and (ii) to assess the effect of smoking on concentrations of serum reproductive hormones. Thirty four NOA patients were involved in the present study. The selection of patients was based on an average of 2 pelleting seminal analysis, reproductive hormones profile and diagnostic testicular biopsy.  A detailed questionnaire was used to obtain a thorough history from the patients. The results of this study showed that the mean age of NOA patients with Sertoli cell only syndrome (SCOS) was 33.875 years, and 47.05 % of NOA patients have had 2-4 years duration of infertility. Macroscopic examination of seminal fluid appeared to have normal values as reported by WHO. Non-significant (P>0.05) difference was observed for testicular size and diameter of seminiferous tubules between right and left testis. High and abnormal concentrations of serum FSH were registered for NOA patients with SCOS. However, non-significant (P>0.05) differences were reported for concentrations of serum reproductive hormones between smokers and non smokers. In conclusion, testicular biopsy is the useful and predictable diagnostic tool for NOA patients with SCOS. Further studies are needed to explain the etiology, management and prognosis of NOA patients with SCOS.
Limits of the Efficiency of Imaging with Obstructing Apertures
Authors: Mohammed A.T.
Published: May 2017

Two-dimensional numerical solutions are carried out to asses the quality of obstructing apertures in terms of the diffraction limited resolution. This include the quality of the point spread function (psf), the modulation transfer function (MTF), and an image of  double lines. These are average intensity of the psf (AI), maximum intensity of the psf,(MI), full width at half maximum of the psf (FW) average frequency components of MTF (AFC), and average side loops of an image of a double lines. The results indicate that the separation of the two lines becomes recognizable using central obstruction of radius equal to or greater than approximately 0.6 times the radius of the primary aperture.
An Overview of Some Practical Quasi-Newton Methods for Unconstrained Optimization
Authors: Al-Baali M. , Khalfan H.
Published: May 2017

Quasi-Newton methods are among the most practical and efficient iterative methods for solving unconstrained minimization problems. In this paper we give an overview of some of these methods with focus primarily on the Hessian approximation updates and modifications aimed at improving their performance.
On Markov Modulated Mean-Reverting Price-Difference Models
Authors: Malcom W. P. , Aggoun Lakhdar , Al-Lawati Mohamed
Published: May 2017

In this paper we develop a stochastic model incorporating a double-Markov modulated mean-reversion model. Unlike a price process the basis process X can take positive or negative values. This model is based on an explicit discretisation of the corresponding continuous time dynamics. The new feature in our model is that we suppose the mean reverting level in our dynamics as well as the noise coefficient can change according to the states of some finite-state Markov processes which could be the economy and some other unseen random phenomenon.
PCR Based Detection of Genetically Modified Soy in Processed Foods Commercially Available in Saudi Arabia
Authors: Alaraidh Ibrahim Abdullah
Published: May 2017

In this research, PCR (polymerase chain reaction) technique was applied to detect the presence of GMO sold in the Saudi Arabian market. This method was applied to detect genetically modified soy (GM-soy) in particular the roundup ready soy (RRS). To confirm the presence of soy, samples were first tested for the existence of the soy specific lectin gene.  A total of eighty samples were tested out of which two samples tested positive as GM-soy. Not surprisingly, the findings showed the existence of GM-soy in food products in Saudi. This supports the necessity of developing precise quantitative and qualitative ways for routine analyses and detection of GMO products in the Saudi Arabian market. With the discovery of GM products in the Saudi Arabian market it would be of no surprise that other Middle Eastern nations also knowingly or unknowingly import GM crops.
Anisotropy in RFe2 Intermetallics: An NMR Study
Authors: Carboni C
Published: May 2017

The anisotropy of the Ho3+, Tb3+ and Tm3+ rare-earth ions in RFe2 compounds is investigated using the field dependence of the NMR spectra of 169Tm, 159Tb and 165Ho in polycrystalline TmFe2, TbFe2, HoFe2 and related pseudo-binary compounds. The very large hyperfine interaction in these ions dominates the NMR spectrum; the NMR frequencies in the 2 to 7 GHz range provide therefore a measure of the localized  moment and its orientation in the crystal field. We compare the NMR measurements to single ion computations that include magnetostriction. KEYWORDS:
Study of Ground water Groundwater Potentiality and Sea Water Intrusion Along along the Coastal Plain, Wadi Thuwal, KSA- A Case Study Based on DC Resistivity
Authors: Al-Garni Mansour A. , Hassanein Hamdy I.E.
Published: May 2017

The present study mainly aims to outline zones that have groundwater potentiality with good quality and those which are affected by sea water intrusion. The electrical resistivity data were acquired over an area of about 170 km2 of a coastal plain, Wadi Thuwal, which is bounded by the Red Sea in the west and the volcanic hills in the east.  In such an area, resistivity measurements, using n-layering model, reveal generally reveal a wide range of resistivity values which do not reflect the reality. Hence, the statistical analysis has to be involved to overcome this problem and to make the final interpretation reliable.  In our case, the n-layer models were modified to another statistical geoelectric models (SLM), consisting of  a number of layers equivalent to the stratigraphic layering beneath each VES site. The modified models were used to outline the depth to the bed rock, groundwater accumulation zones and  water table as well as to define the effect of sea water intrusion through the study area. Check alignment above
Filtering and M-ary Detection of Markov Modulated Mean Reverting Model
Authors: Aggoun Lakhdar , Al-Lawati Mohamed , Malcolm W.P.
Published: May 2017

In an earlier paper we developed a stochastic model incorporating a double-Markov modulated mean-reversion model. The model is based on an explicit discretisation  of the corresponding continuous time dynamics. Here we discuss parameter estimation via the technique of M-ary detection.
Environmental Aspects of the Accelerated Urbanization in Sana’a, Yemen
Authors: Alderwish Ahmed M. , Alderwish Fayad A.
Published: May 2017

From an environmental viewpoint, the prevailing health problems must be a “first priority” in all major development projects. Public water supply provides only 36% of domestic water. Disinfection of public water supply from the south well field is essential to avoid health problems. About 60% of the drinking water sold by ‘hygienic’ stations is of questionable quality. Expansion and upgrading in hospitals, pharmacies and industries (waste producers) will have an immediate impact on the amount of hazardous waste that will have to be disposed of. To achieve a sustainable urban development and to avoid environment/resources degradation, care should be taken now to monitor and improve handling and management of hazardous waste. Initiating management programs for reducing or preventing the generation of waste during production processes or other operations would be the first step to an economically and environmentally sound way of dealing with hazardous wastes. As complete elimination cannot be realized, ways to recycle the wastes should be sought. Major air pollutants in Sana’a include dust and SPM, carbon monoxide, photochemical oxidants, hydrogen sulfide and ammonia, sulfur oxides and hydrocarbons. The main sources of pollution in the cities are the mobile sources. The emissions of gases from oil consumption are exceeding the permissible level and it is essential that the gases be monitored, at least in the congested areas of the cities. Integration of environmental concerns with economic growth in Yemen should occur at the planning stage, adopting a positive approach and focusing on improvement in the health and welfare of the residents of the program area. Mitigating measures relating to the protection of the urban environment and improving public health must be primary objectives of EIA investigation for any upgrading project within urban areas and any other projects impacting on an urban environment.
Surface Morphology of Cus Thin Films Observed by Atomic Force Microscopy
Authors: Kassim Anuar , Min Ho Soon , Siang Lim Kian , Nagalingam Saravanan
Published: May 2017

CuS thin films were deposited onto microscope glass substrates using the chemical bath deposition method in the presence of tartaric acid as a complexing agent. The objective of this paper was to study the influence of the deposition time on the morphology of thin films. The surface morphology of the thin films was investigated using atomic force microscopy. The thin films deposited for the shortest time were found to be   uniform,  without  cracks and with a dense  surface  morphology covering the entire substrate surface area. However, the films prepared for 60 min and above indicated incomplete coverage of the material over the substrate surface. The surface roughness and film thickness values that were observed depended mainly on the deposition time.
Synthesis of Highly Ordered Crystalline Wurtzite (ZnO) Membrane for Selenium-Chromium Separation
Authors: Labib Sh. , Tadros N.A.
Published: May 2017

Pure ZnO and composite ZnO-CeO2 coated thin films on titania substrates were prepared using a chelating sol-gel method under controlled conditions to be used in the separation and/or rejection of Se(IV) and Cr(VI). XRD and SEM studies confirmed the formation of highly ordered arrays of crystalline wurtzite microstructure with mixed orientation. An increase in average particle size of the prepared membranes from 1.25 to 3 µm with increasing CeO2 percent was observed indicating the vital role of CeO2 as secondary phase in improving the crystallinity of the coated films formed. Detailed study of the separation performance of the selected membranes toward Se(IV)-Cr(VI) was studied. A high separation performance for the different membranes prepared was observed toward Se(IV) with respect to Cr(VI). The polar characteristic of ZnO thin films played an essential role in Se(IV) separation. However, a high permeation flow of Cr(VI) through the membranes was governed by the capillary pressure induced within the porous structure of the membranes.
Ground Radiometric Method as a Tool for Determining the Surface Boundary of a Buried Bauxitic Karst
Authors: Kareem Ali Kamal , Awadh Salih Muhammad , Hemad Jassim Muhammad
Published: May 2017

Forty two ground radiometric measurements along nine traverses within a rectangular network area were taken across a bauxitic karst within the Ubaid Formation (Lower Jurassic) in the Western Desert of Iraq. A 4-Channel Gamma Ray Spectrometer (GAD-6) with sodium iodide NaI (Tl) crystal (GSP-4S) was used in the field to measure the total radioactivity of the surface soil. Soil samples collected from the surface at each measurement point and core samples collected from a test well penetrating the karst were analyzed by Gamma ray spectrometer. The main objective of this study was to detect the hidden bauxitic karst and determine its surface boundary. The radioactivity on the surface of the karst was ranging between 60 and 80 count per second (c/s), while the background radioactivity of the Ubaid Formation, which hosts the karst, was ranging between 100 and150 c/s. Chemical weathering, especially dissolution and leaching moved uranium (238U) and thorium(232Th) from the overburden downward. Accordingly, these elements have been adsorbed on the surface of clay minerals and bauxite buried at a depth of about 5m causing enrichment with radioactivity. The leached overburden lack radioelements, so its radioactivity was less than background radioactivity level. The gamma ray spectroanalysis showed that the radioactivity of 238U and 232Th in the overburden was 0.5 and 3 Bq/Kg, whereas, in the bauxite and flint clay bed, it was 240 and 160 Bq/Kg respectively. Based on the radioactivity anomaly contrast on the surface, an isorad map was plotted and the karst diameter which represents low anomaly was determined to be ranging from 150 to 200m. The current study demonstrates that the ground radiometric method is quite useful for detecting the bauxitic karst and inferring its surface boundaries.
Solving the Flood Propagation Problem with Newton Algorithm on Parallel Systems
Authors: Triki Chefi
Published: May 2017

In this paper we propose a parallel implementation for the flood propagation method Flo2DH. The model is built on a finite element spatial approximation combined with a Newton algorithm that uses a direct LU linear solver. The parallel implementation has been developed by using the standard MPI protocol and has been tested on a set of real world problems.
Preconditioning Large Indefinite Linear Systems
Authors: Fasano Giovanni , Roma Massimo
Published: May 2017

After briefly recalling some relevant approaches for preconditioning large symmetric linear systems, we describe a novel class of preconditioners. Our proposal is tailored for large indefinite linear systems, which arise very frequently in many different contexts of numerical analysis and nonlinear optimization. Our preconditioners are built as a byproduct of the Krylov subspace method used to solve the system. We describe theoretical properties of the proposed class of preconditioners, namely their capability of both shifting some eigenvalues of the system’s matrix to controlled values, and reducing the modulus of the other ones. The results of a numerical experimentation give evidence of the good performance of our proposal.
Error Analysis of An Explicit Finite Difference Approximation for the Space Fractional Wave Equations
Authors: Sweilam N.H. , Assiri T.A.
Published: May 2017

In this paper, the space fractional wave equation (SFWE) is numerically studied, where the fractional derivative is defined in the sense of Caputo. An explicit finite difference approximation (EFDA) for SFWE is presented. The stability and the error analysis of the EFDA are discussed. To demonstrate the effectiveness of the approximated method, some test examples are presented.
Fabrication and surface characterization of poly(4-aminodiphenylamine) film modified electrode and its application for lead and cadmium determination
Authors: Al-Hinaai Mohammed M. , Al-Harthi Salim H. , Khudaish Emad A.
Published: May 2017

Poly(4-aminodiphenylamine), Padpa, film was synthesized electrochemically on a glassy carbon electrode by potentiodynamic repetitive cycling of 4‑aminodiphenylamine (4adpa) in 1.0 M HCl. The mechanistic steps involved the oxidation of the protonated monomer to  diimine species which underwent dimerization process to form the mono-charged radical intermediate which was considered as the initiation step for the progress of polymerization. The electrochemical properties and surface morphology of the film modified electrode were characterized using electrochemical and various surface scanning techniques. The XPS data demonstrated the existence of (=N-) bonding responsible for polymer formation, while the AFM image revealed a uniform and symmetrical fiber structure with low energy dissipation. The modified electrode was primarily applied as an environmental sensor for the simultaneous and selective determination of Cd2+ and Pb2+ ions in water samples. The detection limit for Cd2+ and Pb2+ ions was found 25 and 14 mg L-1, respectively.
Synthesis and spectroscopic properties of a fluorosensor for Zn2+ ions
Authors: Al-Rasbi Nawal K. , AlWihibi Bushra , AlNofali Nada
Published: May 2017

The new Schiff base ligand L: (E)-N'-(pyridin-2-ylmethylene)acetohydrazide, was synthesized, and its reaction with Zn(II) ions form the complex: [ZnL2](ClO4)2, as confirmed by X-ray crystallography. This complex is stable in polar and non-polar solvents as proven by NMR. A significant enhancement in the fluorescence was observed from L upon coordination to Zn(II) ions over other transition metals such as Fe(II), Co(II), Ni(II), Cu(II), Cd(II) and Ag(I). These results suggest that L can be used as a selective flourosensor for the detection of Zn(II) ions.
Dioxygen Binding by Cobalt(II) Complexes of 8,8'-bis(aminomethyl)-2,2'-biquinoline
Authors: Khan Muhammad S. , Al-Rasbi Nawal K. , C.Constable Edwin
Published: May 2017

A new series of Co(II) complexes of the type CoLX2 , where Lis a tetra-dentate ligand 8,8'-bis(aminomethyl)-2,2'-biquinoline  and X= SCN–, BF4–, I– or NO3– ,  have been synthesized and characterized. The complexes have magnetic moments in the range typical of a low-spin d7 Co(II) center. The interaction of these Co(II) complexes with dioxygen was studied by E.S.R. spectroscopy. A dicobalt(III) peroxo-bridged complex was formed in DMF solution, associated with the formation of an E.S.R.-silent solution compatible with the formation of low-spin d6 Co(III) species. Similar behavior was also observed for the interaction of these Co(II) complexes with dioxygen in the presence of ancillary ligands such as pyridine and 2-methylimidazole. The dioxygen complexes proved successful as oxygen carrier oxidation catalysts for tripehnylphosphine and 2,6-bis(t-butyl)phenol.
The Influence of Diets Containing Phenols and Condensed Tannins on Protein Picture, Clinical Profile and Rumen Characteristics in Omani Sheep
Authors: Mahgoub Osman , T.Kadim Isam , Babiker Hamza A. , Al-Kindi Mohammed N.
Published: May 2017

A study was carried out to investigate the effects of feeding low quality non-conventional feeds (NCF) containing phenols and condensed tannins on health and performance characteristics in Omani sheep. Twelve Omani sheep were fed one of two base roughages, urea-treated palm frond (UTPF) or Rhodesgrass hay, (RGH) plus a commercial concentrate for 63 days. Haematological, serum biochemical and urine analyses were used to assess sheep health. Serum protein fractions were measured using electrophoresis. Urea-treated palm frond contained higher levels of polyphenols and condensed tannins and fiber than Rhodesgrass hay or concentrate feed. Animals fed UTPF had lower feed intake (P<0.05) and lower body gain (P<0.001) than those fed RGH. Rumen liquor of UTPF-fed animals had higher pH, ammonia-nitrogen and butyric fatty acid but lower acetic fatty acid (P<0.05). Animals fed UTPF had  higher neutrophil (P<0.05) but lower lymphocyte (P<0.05) and monocyte (P<0.001) counts by the end of the trial than those fed RGH. There were no effects of diet on serum albumin or globulin fraction levels or albumin:globulin ratio. There were no major effects on urine analysis but there was a trend by control animals to have higher protein and specific gravity than treated ones. This study indicated that feeding low quality non-conventional feeds containing polyphenols or tannins would reduce body gain and may produce some effects on clinical parameters. Although tannins are known to influence protein digestion and absorption in ruminants, it did not significantly affect the serum protein picture in sheep.