bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF RAPID THERMAL TREATMENT CONDITIONS ON ELECTROPHYSICAL PROPERTIES OF CROMIUM THIN FILMS ON SILICON
Authors: Solovjov J. A. , Pilipenko V. A.
Published: December 2019

Present paper is devoted the determination of the effect of the temperature of the process of rapid thermal treatment of chromium films on n-type conductivity silicon on their resistivity and contact properties of the interface. Chromium films of about 30 nm thickness were deposited by magnetron sputtering onto the surface of silicon substrates having a resistivity of 0.58 to 0.53 ohms×cm. The rapid thermal treatment was carried out in a heat balance mode by irradiating the back side of the substrates with non-coherent light flux in nitrogen ambient for 7 seconds. Quartz halogen incandescent lamps were used as the heating source. The temperature of the rapid thermal process ranged from 200 to 550 °C. The thickness of the chromium films was determined by raster electron microscopy. The surface resistance of the samples was measured by a four- probe method. The Schottky barrier height and the ideality factor were determined from I-V plots. It is shown that at the temperature of the rapid thermal process 400 °C a layer of chromium disilicide is formed, causing a sharp increase in the resistivity of chromium films to 1.2 mOhm×cm and the height of the Schottky barrier to 0.6 V. When the temperature of the rapid thermal process is further increased to 550 °C, the resistivity increases monotonically to 4.0 mOhm×cm due to the increase in the width of the interstitial boundaries increasing the scattering of charge carriers in the CrSi2 layers. It has also been shown that rapid thermal treatment of the Cr/Si structure at a temperature of 450–500 °C enables to obtain rectifying contacts with a barrier height of 0.615 V and an ideality factor of 1.1. The results obtained can be used in the technology of integrated electronics products containing Schottky contacts as well as thin film resistors.
OPERATION OF THE RADIOLOCATION ANGULAR SYSTEM IN THE CONDITIONS OF THE SIGNAL CREATED BY COHERENT SOURCES OF RADIATION FROM TWO SPOTS
Authors: Dyatko A. A. , Kostromitski S. M. , Shumski P. N. , Davydenkо I. N.
Published: December 2019

The purpose of the work, the results of which are presented within the framework of the article, was to analyze the operation of the radar goniometer system under the conditions of a signal generated by coherent radiation sources from two points in space (cross-eye interference). To achieve the goal in the present work, a study was made of the dependence of the settings of the goniometric system on the ratio of the parameters of the cross-eye jammer and the angular coordinate meter itself. As a goniometric system, an angular coordinate meter was used, operating by the method of amplitude instantaneous signal comparison. The studies were carried out by the method of theoretical analysis of the influence of the radiation pattern parameters of the antenna system of the meter on the result of measuring the angular position of a virtual radiation source. As a result, an equation is obtained that relates the angular position of the virtual radiation source with the radiation pattern parameters of the antenna system of the meter, the shape of which was approximated by a gaussian curve. To illustrate the functioning of the goniometric system at specific values of the parameters supplied to its input signals, the method of mathematical modeling was used. Modeling was performed for the given parameters, which determine both the position of the radiation sources in space and the algorithm of operation of the angular coordinate meter. Based on the results obtained, it is shown that the angular coordinate meter has three stationary states corresponding to the position of the virtual radiation source in space. It is shown that only two of these states are stable. The latter means that, depending on the initial conditions, the angular coordinate meter can fix one of the two possible positions of the virtual radiation source in space. The scientific novelty of this work is to establish a relationship between the position of the virtual radiation source in space and the parameters of the angular coordinate meter.
SYNTHESIS OF QUASI BAND LADDER TRANSFORMING HIGH ORDER FILTERS
Authors: Kurochkin A. E.
Published: December 2019

The purpose of the work, the results of which are presented in the article, was to develop a computerized mathematical model of the ladder filter to study the features of the synthesis of matching chains of any order on its basis. To achieve this goal, all the synthesis tasks were solved, including the choice of the prototype, frequency transposition, calculation of the poles of the transfer function of the prototype, calculation of the poles of the transfer function of the filter, calculation of the reflection coefficient of the filter, the calculation of the input resistance of the filter, the implementation of the ladder chain by the Cauer method and denormalization of the values of the elements of the ladder chain. Modeling of characteristics of ladder filters of any high order with frequency characteristic of Chebyshev on the computer with 32-bit operating system is carried out. It is shown that the use of standard mathematics leads to a significant increase in the error of matching of loads at increasing the order of the chain. To increase the accuracy of calculations it is proposed to use software that allows implementing mathematical operations on variables with any length of the mantissa. There are computer libraries where numbers are presented in the form of string type variables and arithmetic operations are carried out on them according to school rules “ in a column ” . Once the calculations are completed, the strings are converted back to normal numbers. The article considers the application of the variant of BigNumber library for high level JavaScript language. To estimate the accuracy of the calculation it is proposed to apply the property of antimetric ladder structure. From the presented results of the calculation it follows that in order to obtain not less than 15 reliable digits after the decimal point for the parameters of the n-th order filter it is necessary to increase the length of the variable mantissa to the value 2n.
SPECTRUMS OF SUPERCONDUCTING STATES AND TRIPLET EFFECTS IN SUPERCONDUCTOR/FERROMAGNET MULTILAYERS
Authors: Kushnir V. N.
Published: December 2019

We report the results of studies of triplet superconductivity in structures with alternating superconductor and ferromagnet layers, as a part of the general problem of the properties of the spectra of superconductivity states depending on the magnetic state of the multilayer structure. Ferromagnetic layers are assumed monodomain and possessing inplane magnetic moments. In numerical examples, we used the parameters of the well-studied Nb/PdNi system. The critical temperatures and distributions of singlet and triplet currents depending on the relative orientation of the magnetic moments of the ferromagnetic layers are calculated in the formalism of the Usadel equations for 5- and 3-layer irregular structures. The following results are obtained. (1) The channeling effect of triplet pairs by a narrow central layer of a superconductor with complete suppression of the singlet component in it was confirmed. (2) The “0–1”-transition between the phases of a superconducting condensate of opposite symmetry induced by the transport current is predicted. (3) The effect of a double crossover of states on the dependence of the critical temperature, Tc, versus the angle θ between the magnetic moments of the ferromagnetic layers adjacent to the central layer of the superconductor in a 3-layer structure is predicted. The crossovers are reflected by a sharp turns in the Tc (θ) curve, while the infinitely small asymmetry of the structure eliminates the non-analyticity of this characteristic.
FORMATION OF OPTIMAL PARAMETRS OF THE TRAJECTORY OF THE OVERFLIGHT OF UNMANNED AERIAL VEHICLE THROUGH THE SPECIFIED POINTS OF SPACE
Authors: Lobaty A. A. , Bumai A. Y. , Jun Du
Published: December 2019

The purpose of the scientific research, results are determinated in the article, is to analytically synthesize the control law of an unmanned aerial vehicle while guiding one along the trajectory that specified by the reference points of space in an inertial coordinate system. The analysis of various existing approaches of the formation of a given flight path of an unmanned aerial vehicle based on various mathematical formulations of the problem is carried out. To achieve the goal, the flight path is considered as separate intervals, where the control optimization problem is solved. The optimization criterion in general form is substantiated and its presentation in the form of a minimized quadratic quality functional is convenient for analytical control synthesis. As components of the functional, the parameters of the deviation of the flight path of the aircraft from the specified points of space are considered, as well as the predicted parameters of the velocity vector and the control normal acceleration. Moreover, at each specified point in space, the direction of the trajectory to the subsequent point is taken into account, that ensures optimal curvature of the trajectory by specified flight speed of the unmanned aerial vehicle. As a result of analytical synthesis, mathematical dependences are obtained to determine control acceleration, which allow us to get a specified optimal control law on board an unmanned aerial vehicle, which ultimately ensures minimum energy consumption. The validity of the proposed theoretical provisions is confirmed by a clear example, where for a simplified mathematical problem statement the optimal laws of change in control acceleration and the trajectory parameters of an unmanned aerial vehicle are calculated by computer simulation.
THE METOD OF SYNTHESIS OF MULTIBAND MATCHING DEVICE
Authors: Yantsevich M. A. , Filippovich G. A.
Published: December 2019

The purpose of this work is to provide the estimation of the potential abilities of analytic broadband matching methods for complicated load terminations. The article covers the problem of synthesis of mylti-band frequency response matching circuits. Results presented in the article are of prime interest for communications systems from one point and the lack of advanced analytic methods from another. The problem of multiband impedance matching is under consideration. Presented is the method of synthesis of multiband matching circuits for arbitrary complex loads, based on the generalized Darlington approach to the lumped circuits design. Frequency response for the synthesis is obtained as a result of double-band reactance transformation in the process of reflection coefficient factorization. The factorization results in the analytic representation of the reflection coefficient function on the complex surface. This method allows to identify functional limitations on broadband matching and for the first time to obtain analytical solutions for the loads of practical value. Application of the method is demonstrated in the detailed procedure of realization of double-band Batterworth frequency response for the resonance load (RLC-load). It would be pertinent to stress, that presented results concerning the double-band synthesis of resonance load have no coverage in technical literature. The method also features the analytic description of the design parameters as functions of load termination parameters which provides a road-map to conceptual design of multiband matching circuits.
TERAHERTZ TRAVELING-WAVE TUBE ON A RECTANGULAR WAVEGUIDE FOLDED IN A CIRCULAR SPIRAL
Authors: Kurayev A. A. , Matveyenka V. V.
Published: December 2019

The most promising in the THz range is traveling-wave tubes (TWTs) and backward-wave tubes (BWTs) on a serpentine-curved (zigzag-rolled) rectangular waveguide. They are implemented in the THz range (220 GHz), although their characteristics are far from satisfactory due to the strict restriction on the tape electron beam width, that does not allow reaching the summarizing beam current optimum level. To replace the zigzag convoluted waveguide with the spiraled for the TWT and BWT on a curved rectangular waveguide is the best way to remove the ribbon beam width restriction. In the early TWT and BWT design a waveguide planar spiral was also flat in the upper and lower parts connected by vertical idle (without beam) transitions. Proposed design can be significantly improved both in relation to the electron interaction process with the waveguide field and in relation to the TWT-BWT manufacturing technology if instead of a planar waveguide spiral, a circular one is used. The article proposes the TWT designing a terahertz rectangular waveguide folded as a circular spiral. The design differs from the previously proposed TWT with a planar-spiral waveguide by the improved interaction conditions between the electron beam and the waveguide field, as well as the manufacturing technology simplification for terahertz range. Based on numerical simulation, it is shown that proposed TWT achieves Gн = 42÷48 dB saturation gain in the 220 GHz range with the waveguide turn number n = 40÷50. The proposed TWT design on a rectangular waveguide folded in a circular spiral is more technologically advanced than the TWT on a planar-spiral waveguide. In the most necessary 220 GHz range the efficiency is very high and can provide the need for amplifiers and generators in this and other ranges. We also note that the TWT on a spirally folded waveguide can operate in the BWT mode and, moreover, simultaneously in the TWT and BWT modes.
İlkokul Dördüncü Sınıf Öğrencilerine Yönelik Özdüzenlemeli Öğrenme Envanteri’nin Geliştirilmesi: Geçerlik ve Güvenirlik Çalışması
Authors: ÇOKÇALIŞKAN Halil , Sakız Gönül , DOĞAN Midrabi Cihangir
Published: December 2019

Bu araştırmanın
amacı dördüncü sınıf öğrencilerinin özdüzenlemeli öğrenme düzeylerini
belirlemeye yönelik bir ölçek geliştirmektir. Geçerlik ve güvenirlik
çalışmaları için 520 ilkokul dördüncü sınıf öğrencisinden veri toplanmıştır. Araştırma
sonucunda özdüzenlemeli öğrenme envanteri (ÖÖE) öndüşünme (12 madde), performans
(11 madde) ve özyansıtma (11 madde) ölçeklerinden oluşmuştur. Elde edilen
ölçeklerin faktör yükleri .52 ile .73 arasında, madde test korelasyonlarının ise
.45 ile .65 arasında değişmektedir. ÖÖE’nün öndüşünme, performans ve özyansıtma
ölçeklerinin açıkladıkları varyanlar sırasıyla % 40, % 41, % 44 ve iç tutarlık
katsayılarının ise sırasıyla .86, .84, .87 olduğu tespit edilmiştir. ÖÖE’nün
tüm maddeleri için %27’lik alt ve üst grupların ölçek puanları arasında anlamlı
fark elde edilmiştir. Ayrıca 237 kişilik farklı bir örneklem üzerinde
gerçekleştirilen doğrulayıcı faktör analizi sonucunda tespit edilen yapının
uyum indeklerinin iyi düzeyde olduğu görülmüştür. Bu sonuçlar neticesinde
ÖÖE’nün geçerli ve güvenilir bir envanter olarak kullanılabileceğine karar
verilmiştir.
Yabancılara Türkçe Öğretenlerin Başvurdukları Kelime Öğretim Stratejilerinin Belirlenmesi
Authors: MEMİŞ Muhammet
Published: December 2019

Bu araştırmanın amacı, yabancılara Türkçe öğretimi alanında
görev yapan öğreticilerin süreç boyunca işe koştukları kelime öğretim
stratejilerini belirlemek, ayrıca öğretim tecrübesi, mezuniyet alanı ve hedef
kitlenin bulunduğu dil düzeyinin öğreticilerin strateji kullanımı üzerinde
herhangi bir etkisinin olup olmadığını ortaya çıkarmaktır. Bu kapsamda, çalışma
tarama modellerinden araştırma amacına uygun olan betimsel tarama modelinde
desenlenmiş olup veriler Memiş (2019) tarafından geliştirilen Kelime Öğretim
Stratejileri Ölçeği aracılığıyla 2018-2019 eğitim-öğretim yılı içerisinde
toplanmıştır. 5’li likert tipinde bir ölçek olan KÖSÖ, öğretme stratejileri (21
madde), açıklama stratejileri (9 madde), pekiştirme stratejileri (6 madde),
beceri kazandırma stratejileri (6 madde), yönlendirme stratejileri (5 madde) ve
kontrol stratejileri (3 madde) şeklinde 6 boyuttan ve toplam 50 maddeden
oluşmaktadır. Ölçeğin Cronbach Alfa güvenirlik katsayısı ise (α)=.89’dur.
Araştırmanın evreni, Türkiye’deki resmi kurumlarda yabancılara Türkçe öğreten
öğreticiler olup örneklemde 164 öğretici bulunmaktadır. Çevrimiçi olarak elde
edilen verilerin analizinde betimsel istatistik ve tek yönlü Anova kullanılmıştır.
Araştırmada, ikinci dil olarak Türkçe öğreten öğreticilerin kelime öğretim
stratejilerini orta düzeyde kullandıkları; öğreticilerin dil öğretim tecrübesi
ile lisans mezuniyet alanlarının kelime öğretim stratejilerine başvurma
durumunu etkilediği ve hedef kitlenin bulunduğu dil seviyesinin öğreticilerin
strateji kullanım sıklığı üzerinde etkisi olduğu anlaşılmıştır.
An Application for Load Sharing in Trucks
Authors:   Professor, Department of ECE, Sona College of Technology, Salem, Tamil Nadu, India., Sabeenian* Dr. R. S. , Kumar Dr. R. Vinod ,   Senior Professor, Department of ECE, Sona College of Technology, Salem, Tamil Nadu, India., Ravi Dr. G. ,   Department of Information and Communication Engineering, Anna University, Chennai, India., Pudasaini Mr. Ashok ,   Department of Communication System, Sona College of Technology, Salem, Tamil Nadu, India.
Published: December 2019

The paradigm of the world has shifted to mobile applications. The services that you need are at your fingertips because of the mobile applications which provide online access to the services you have. Several mobile applications like uber freight, ola are present to facilitate the freight service providers. The existing freight management system depends on the model of separating the users on the basis of fleet provider, normal user and one with the large number of vehicles called as freight provider. For a user to login to the system the user can easily enter his desired destination and send his or her belongings to that destination with the online reservation platform provided by the mobile application. Though the existing system is good but it has one limitation. The limitation of all the existing system is that they don’t monitor the load in the vehicle. In order to overcome this limitation, we propose a system which will monitor the load present in the vehicle in real time. We propose a cross platform mobile application which will work on all the available platform. The main aim of the proposed system is to monitor the load present in the truck. The proposed system will use the ultrasonic sensor in the load bearing part of the truck and the total volume as well as the available space in the truck will be continuously monitored and notified to the user who wants to send the load. We will also take into consideration the density of the material so that if the user wants to add a new load the existing load won’t be affected. The path of the truck will also be monitored from origin to destination. The proposed method will develop an application for continuous monitoring of the load in the truck. The main application of the system is use in freight management system for monitoring the load of the vehicle and notifying the users whether the space is available for the vehicle to carry their loads.
Compromiso Organizacional y Riesgos Psicosociales
Authors: Salvador Moreno Janeth Elizabeth
Published: December 2019

Existen múltiples investigaciones sobre compromiso organizacional, que definen los niveles de afinidad o apego entre el trabajador y la entidad, como de riesgos psicosociales, que examinan, que elementos pueden afectar su salud; por ello se realiza una revisión sistemática exploratoria con el objetivo de destacar relaciones entre ellas (compromiso y riesgo) y otros elementos que a su vez permitan mejorar el rol del trabajador dentro de su institución. La presente revisión abarca investigaciones diversas, entre artículos científicos y trabajos doctorales, que van allanando el dilucidar de las complejidades del individuo en el plano laboral y han determinado que factores, como la estabilidad contractual, el salario, el estilo de supervisión y los temas comunicacionales, están vinculados con los niveles de compromiso organizacional y además son elementos presentes en los factores de riesgo psicosocial que lesionan su salud, lo que permite inferir elementos comunes.  Esta revisión es la antesala de una investigación doctoral que aplica las mediciones de compromiso organizacional y riesgos psicosociales para determinar la existencia de correlación entre ambas.
La cultura organizacional como base para la permanencia en las organizaciones.
Authors: Palafox Soto María Olivia , Ochoa Jiménez Sergio , Jacobo Hernández Carlos Armando
Published: December 2019

Los estudios de cultura organizacional son cada vez más relevantes en el panorama actual, debido a su importancia como activo intangible de la organización, es por ello que el presente trabajo tiene como finalidad mostrar un análisis descriptivo a través de una revisión de literatura de los diversos elementos que la conforman. Los principales hallazgos afirman que el bienestar laboral, misión, visión, valores, objetivos, liderazgo, participación, entre otros elementos influyen en la permanencia de las empresas. Por ello, se recomienda que las organizaciones den primordial importancia a los aspectos que configuran la cultura, contribuyendo a que las empresas subsistan a través del tiempo, además de seguir realizando revisiones de literatura de este tipo como base importante para futuras investigaciones.
Retos y estrategias para el desarrollo del turismo de negocios en ciudades ecuatorianas
Authors: Pancorbo Sandoval José Armando , Leyva Ricardo Sonia Emilia , Rodríguez Veiguela Yanlis , Vega Falcón Vladimir
Published: December 2019

Los segmentos de mercado de naturaleza y de sol y playa, han sido el eje de la actividad turística ecuatoriana, ignorándose que el turismo de negocios es el que más crece internacionalmente en la actualidad, lo cual constituye un problema a investigar. El estudio MICE Travel Report 2018, mostró que los viajes MICE a Latinoamérica vienen creciendo notablemente, incluyendo a países sin tradición, como es el caso de Ecuador. Se tuvo en cuenta un procedimiento basado en un modelo para desarrollar un clúster turístico para la ciudad ecuatoriana de Santo Domingo Tsáchilas y los resultados de la aplicación del Método del Open Space, para lo cual se propició un taller sobre las implicaciones del turismo de negocios. El presente estudio tuvo como objetivo evaluar la relevancia del turismo de negocios en la ciudad de Santo Domingo de los Tsáchilas. Se evidenció que en dicha ciudad existe una deficiente planeación, gestión, coordinación y articulación entre las políticas públicas y privadas en materia turística. Se concluye que la ciudad de Santo Domingo cuenta con el potencial necesario para desarrollar el destino de turismo de negocios, pero para ello debe lograr la cohesión entre los sectores público y privado.
Producción científica de profesores en Universidades Peruanas: motivaciones y percepciones
Authors: Barrutia Barreto Israel , Acosta Roa Erika Raquel , Marín Velásquez Tomás Darío
Published: December 2019

El Perú ocupó en año 2018 el séptimo lugar en producción científica en Latinoamérica, según el ranking Scimago, subiendo apenas dos puestos desde el año 2008. Por lo anterior, el estudio  se centra en conocer la producción científica de docentes peruanos, comparando dos universidades, la Universidad Cesar Vallejo y Pontificia Universidad Católica del Perú. La investigación fue no experimental, descriptiva y comparativa. Se aplicó un muestreo probabilístico con n = 582 participantes en total. Se utilizaron datos del Directorio Nacional de Investigadores e Innovadores, así como un cuestionario para obtener la motivación y percepción de los docentes. Se evidencia que la producción científica se desarrolla de manera desigual, favoreciendo a la Pontificia Universidad Católica del Perú, que presenta mayor desarrollo. A la mayoría de los docentes los motivan las normativas de educación superior del país (48%) y se percibe falta de apoyo económico y asesoría técnica para la producción científica.
La competitividad en las microempresas en Manta 2019
Authors: Rodriguez Arrieta Gonzalo Andrés , Cano Lara Evelyn Dyann , Ruiz Velez Andrea Lissete
Published: December 2019

Las microempresas en el Ecuador representan el 90,78% del total de empresas, significando un conjunto de organizaciones de vital importancia para el país, destacándose el aporte en lo económico como al empleo. Pero al igual que cualquier otra empresa, la competencia en un mundo globalizado es el punto clave para lograr la supervivencia y continuidad en el tiempo. Es en este marco que se estudió el grado de competitividad de las microempresas dentro del Cantón Manta - Ecuador. Por ello se realizó un estudio descriptivo, de base cuantitativo, a fin de medir la percepción de los empresarios de microempresas a través de la adaptación de un instrumento de medición comprobado. Las características y particularidades que se han mostrado a lo largo de esta investigación se complementan en lo teórico y práctico, en cuanto a la informalidad, baja capacitación, poca planificación, dificultades financieras, entre otros. El comportamiento de los datos demuestra una proporción dos a uno en las respuestas de acuerdo con relación a las de en desacuerdo, midiendo de esta manera una competitividad aceptable por parte de las microempresas en Manta.
Riesgo físico y enfermedades profesionales en trabajadores que operan equipos de vibración en construcciones civiles
Authors: Ormeño Bazurto Luis Alfredo
Published: December 2019

Los Riesgos Físicos y Enfermedades Profesionales presenta un conjunto de definiciones y criterios médicos de tipo jurídicos y técnicos ajustados a la higiene industrial, donde la prevención de riesgos laborales juega un rol importante El objetivo de este estudio es describir el riesgo físico y enfermedades profesionales en trabajadores que operan equipos de vibración en construcciones civiles. Como metodología se adoptó la revisión sistemática exploratoria con enfoque cualitativo que orienta a realizar una revisión bibliográfica sintetizada, sobre los riesgos y posibles enfermedades ocupacionales provocadas por exposición a las vibraciones en el lugar de trabajo; el método bibliográfico, fue necesario para explicar teóricamente las variables estudiadas y esquematizar la información. El estudio se basa en la Norma ISO 5349 (medida de vibraciones mano-brazo) y la ISO 2631 (de cuerpo entero). Concluye la investigación a partir de la síntesis de los resultados obtenidos, dando respuesta a lo que respecta a materia de Riesgos Físicos y enfermedades profesionales en trabajadores que operan equipos de vibración, para lo cual se requiere que los Estados impulsen políticas preventivas que orienten las actuaciones de este grupo humano.
Динамически вулканизованные нанокомпозиты на основе рандом полипропилена, бутадиен-нитрильного каучука и каолина
Authors: Кахраманов Н.Т. , Гулиев А.Д. , Песецкий С.С.
Published: December 2019

Приводятся результаты исследования влияния концентрации каолина на основные физико-механические свойства нанокомпозитов в эластопластах на основе смеси рандом полипропилена с бутадиен-нитрильным каучуком различных марок. С целью улучшения совместимости смешиваемых компонентов смеси в качестве компатибилизатора использовали привитой сополимер полипропилена с метакриловой кислотой. Рассмотрен механизм компатибилизации привитого сополимера в граничной области в зоне контакта рандом полипропилена с бутадиен-нитрильным каучуком. В качестве каучукового компонента использовали нитрильный каучук с 18, 26 и 40% содержанием нитрильных групп. Установлено влияние различных агентов вулканизации на свойства нанокомпозитов. Определены оптимальные концентрации сшивающих компонентов, при которых обеспечивается возможность получения динамически вулканизованных нанокомпозитов.
Реологические свойства композитов на основе бентонитовой глины и смесей полиэтилена высокой и низкой плотности
Authors: Мустафаева Ф.А.
Published: December 2019

В статье приводятся результаты исследования реологических характеристик композитов, полученных на основе бентонитовой глины и смесей полиэтилена высокой и низкой плотности. Установлено влияние концентрации бентонита, температуры и напряжения сдвига на закономерность изменения эффективной вязкости и скорости сдвига, определена энергия активации и показатель текучести расплава композитов. Все композитные материалы были на основе смесей полиэтилена высокой и низкой плотности, взятых в соотношении 50/50. Исследования проводились с образцами, содержащими 1, 3, 5, 10, 20 и 30 масс. % бентонита.
Угле-титановые композиты: микроструктура, прочность и трещиностойкость
Authors: Милейко С.Т. , Галышев С.Н. , Колчин А.А. , Кедров В.В. , Шахлевич О.Ф. , Никонович М.Ю. , Прокопенко Н.А.
Published: December 2019

В настоящей статье описывается иерархическая структура композитов с углеволокном и титановой матрицей, получаемая жидко-твердофазной технологической схемой, которая позволяет пропитывать волоконную ленту или ткань относительно легкоплавкой, содержащей титан, эвтектикой, в рассматриваемом случае — Ti–Ti2Ni, с формированием тонкого слоя карбида титана на границе раздела волокна и эвтектики. Титановый слой играет роль пластичной металлической матрицы. Прочность композита такого типа с технически чистым титаном в качестве матрицы превышает 1000МПа, критический коэффициент интенсивности напряжения превышает 30 МПа•м1/2. Важным является малая анизотропия характеристик прочности композитов. Композиты могут быть использованы при температурах, по крайней мере, до 700°С.
Ультравысокотемпературные композиты с матрицей карбида гафния
Authors: Акопджанян Т.Г. , Хвостунков А.А. , Милейко С.Т.
Published: December 2019

Композиты с углеволокном и карбидом гафния в качестве матрицы получены методом горячего прессования. Микроструктура полученных композитов позволяет судить об отсутствии химического взаимодействия между волокном и матрицей. Зависимости прочности при изгибе и трещиностойкости композитов от содержания углеволокна имеют максимумы. Объёмные содержания волокна, при которых достигаются максимумы величин прочности и критического коэффициента интенсивности напряжений равны ~6 и 10, соответственно. Средние максимальные величины этих характеристик равны ~340 МПа и ~8,7 МПа•м½. Эти же характеристики для неармированной матрицы, полученной в том же режиме, суть 250 МПа и 4,9 МПа•м½.
UJI AKTIVITAS ANTIOKSIDAN EKSTRAK ETANOL BEE POLLEN LEBAH TRIGONA (Trigona itama)
Authors: Wardaniati Isna , Taibah Surhiyatun
Published: December 2019

Bee pollen memiliki kandungan bahan kimia yang kompleks dan beragam membuat bee pollen mempunyai khasiat yang bermacam-macam, salah satunya adalah sebagai antioksidan. Bee pollen merupakan salah satu bahan yang mengandung antioksidan alami berupa flavonoid, polifenol dan karotenoid. Kandungan Antioksidan berfungsi sebagai menetralisasi radikal bebas, sehingga tubuh terlindungi dari berbagai macam penyakit degeneratif dan kanker. Adapun tujuan dari penelitian ini adalah untuk mengetahui aktivitas antioksidan (AA) ekstrak etanol bee pollen lebah trigona (Trigona itama) menggunakan metode β-karoten bleaching secara spektrofotometri Uv-Vis. Hasil penelitian menunjukkan bahwa ektrak etanol bee pollen lebah trigona (Trigona itama) memiliki   nilai   aktivitas antioksidan (AA) sebesar 66,2% (intermediate) sedangkan asam askorbat sebagai kontrol positif sebesar 97,7% (antioksidan kuat). Dari hasil penelitian dapat disimpulkan bahwa ektrak etanol bee pollen lebah trigona (Trigona itama) memiliki khasiat sebagai antioksidan dengan golongan aktivitas antioksidan (AA) intermediet (sedang).
Crisis Normativas y Circunstanciales del Sistema Familiar de Hijos de Personas Privadas de La Libertad
Authors: Villacís Tania
Published: December 2019

El objetivo del estudio es describir las crisis normativas y circunstanciales de las familias con miembros privados de la libertad. De enfoque cualitativo; se aplicó entrevista de Montalvo y Soria, test proyectivos, terapia de Juego y observación directa a los participantes en su microsistema y mesosistema, la población de estudio es una muestra de casos tipo de niños, adolescentes y familias de la Fundación Somos Familia-Cuenca. La información recolectada indica que entre las crisis que experimentan se identifica ciclo vital de familia con hijos escolares, con hijos adolescentes y con hijos adultos, sin embargo, por los cambios en el acogimiento y transición de una familia a otra, los menores en especial hijos primogénitos y mujeres asumen la parentalización. De igual manera, vivencian crisis circunstanciales como la pérdida, separación, enfermedad y económica, que repercuten en el desarrollo integral de los niños, niñas y adolescentes, además de la repetición de patrones transgeneracionales en el círculo de la violencia y actos delictivos. De acuerdo con otros estudios y el análisis de los casos presentados, se evidencia que no se cuentan con procesos de rehabilitación social y mucho menos proyectos que integren a los hijos e hijas y familias de las personas privadas de la libertad.
Should We Fear Ourselves? A Discussion about the Future of Our Species: Will Science and Technology Redeem Our Specie in the Future? Or Will Science and Technology Be the Source of Our Collective Downfall?
Authors: Hernández Martha
Published: December 2019

When looking back into our history, science and technology have been the tools used by our species to fight its survival battle against its old enemies (diseases, famine, epidemics, etc.). But, ever since human discovered genetics and NBIC technologies (nanotechnology, biotechnology, information technology and cognitive science), our ambitions went one step further. We do not longer limit ourselves to ‘fix’ the Homo sapiens. Now we dream of enhancing the Homo sapiens and bring it into the next level: the Homo Deus. The consequences of our desires remain uncertain; but whatever they are, we need to accept that in a not too distant future the notions and understandings about ‘being human’ will appear less straight forward and even start to fade away. This paper discusses the senses in which science and technology have made humanity more distinctive as a species. As constructors of our own future, we need to question: will science and technology redeem humanity in the future? Or will they be the source of our collective downfall?
Relación de la Economía Circular, la Tecnología Cero Desechos, la Bioeconomía, la Biorrefinería y el Desarrollo Sostenible y Sustentable
Authors: Orejuela Lourdes
Published: December 2019

Este artículo es una revisión bibliográfica y responde a la preocupación de que el crecimiento poblacional y el estilo de vida moderno basado en la industrialización de materia prima no renovable están llevando al agotamiento de los recursos naturales y no será ni sustentable ni sostenible indefinidamente. Por lo tanto, es necesario buscar alternativas que produzcan bienes y servicios que generen menor impacto ambiental. Este documento explica la relación entre de Economía Circular, Tecnología Cero Desechos y el procesamiento de biomasa residual, como parte de la Diversidad Biológica, en las llamadas Biorrefinerías para lograr un desarrollo sostenible. Primero, se analiza la población mundial y los grandes volúmenes de desechos agroindustriales que impactan negativamente el ambiente. De ahí que la FAO promueva la Bioeconomía y la Economía Circular basada en la Tecnología Cero Desechos como una estrategia de Desarrollo Sostenible y Sustentable
Conexión de Programa en Java con Circuito de una Alarma en Arduino Uno con la Libreria Panama Hitek Arduino 2.8
Authors: Peralta Valeria , Faicán Diana , Pinos Jéssica
Published: December 2019

El siguiente proyecto tiene como propósito utilizar la librería PanamaHitek_Arduino-2.8.1 para realizar conexiones de un circuito eléctrico en Arduino con un programa realizado en Java, lo que permite aplicar una técnica diferente en el uso de circuitos eléctricos conectados a interfaces gráficas. Para realizar la comunicación con un circuito eléctrico con programación Java se utilizaba microprocesadores programados en C++ para lo cual es necesario conocer este lenguaje de programación además de saber el correcto funcionamiento de los microprocesadores. Sin embargo, con la librería propuesta se puede optimizar el trabajo y costos del circuito ya que no es necesario el uso de microprocesadores lo que da como resultado un circuito muy sencillo y óptimo. Para demostrar lo dicho se realizará un programa que enciende una alarma cada vez que detecta movimiento dentro de la casa, para lo cual se utilizó un circuito hecho con Arduino Uno, el cual se comunica con el software en Java mediante una clase que usa métodos de la librería PanamaHitek_Arduino-2.8.1.
Corte de Encendido de un Vehículo ante la Presencia de Alcohol
Authors: Urgilés Pablo , Cárdenas Guillermo , Castro Néstor , Chuchuca Jhonny , Encalada Edgar , Morocho Byron
Published: December 2019

El propósito de este trabajo es desarrollar un sistema que permita detectar la presencia de alcohol para implementarlo en el circuito de encendido de un vehículo y evitar que el motor de éste encienda cuando detecte al conductor en estado etílico. Se desarrolla el sistema bajo la plataforma de hardware y software libre con código abierto, esto mediante Arduino Uno, un sensor de distancia que evita que el conductor u ocupantes burlen la acción del sistema y un sensor de tipo electroquímico que comercialmente se lo conoce como MQ-3. Los resultados del sistema desarrollado muestran una adecuada implementación en las pruebas desarrolladas por el sistema y contrastadas por un instrumento de medición homologado. El margen de error entre ambos sistemas no alcanza el 1% cuando se pone a prueba al sistema en diferentes personas y diferentes tipos de licores luego de los primeros 15 minutos de haber ingerido una medida de licor. El sistema se instala en la parte superior del tablero, frente a frente con el conductor, junto con la pantalla display la cual detallará los siguientes valores: nivel de alcohol, distancia de separación entre el conductor y la placa.
Proximal Migration of Lumboperitoneal Shunt Catheter Up To Cervical Spine
Authors: UMERANI MUHAMMAD SOHAIL , MOSTAFA GABR AHMED , FARAG AHMED ADEL ABDELLATIF , LATIF FARAG ABDEL , ABBAS ASAD
Published: December 2019

Lumboperitoneal (LP) shunt had been in use as an internal cerebrospinal fluid (CSF) diversion for a variety of different indications, namely benign intracranial hypertension, communicating hydrocephalus, slit ventricle syndrome and CSF fistulas. Generally considered to be a simple surgical procedure but certain potential complications are associated with this technique, including chronic subdural hematoma, subarachnoid haemorrhage, acquired Chiari malformations and migration of the shunt tubing.1, 2 Proximal intrathecal migration of LP shunt catheter tip, high up in the cervical spine is a rare reported complication.3, 4, 5, 6, 7, 8 If doubtful on X-rays, Computed Topography (CT) scan confirms the diagnosis. Although multi factorial, this proximal migration is usually because of a faulty technique when anchoring sutures are loosened or cut. Measures employed to avoid this potential complication include appropriate technique for securing the LP shunt tube at the proximal lumbar and the distal peritoneal insertion sites with suture collars, thus enabling fixation of the tube. We report a case of an obese middle age female who developed proximal migration of the lumbar tube up to cervical spine, after having undergone LP shunt for pseudotumor cerebri.
Clinical Outcome of Percutaneous Radiofrequency Rhizotomy for Trigeminal Neuralgia at a Tertiary Care Hospital.
Authors: Raza Muhammad Hassan , Hassan Adeeb ul , Ali Omair Afzal , Mahmood Khalid
Published: December 2019

Background: - Trigeminal neuralgia is a disease typically characterized by involuntary attacks of lancinating pain in the distribution of the trigeminal nerve that are activated by non-noxious stimuli. Numerous anticonvulsants, either alone or in combination, remain the first choice in the medical treatment of trigeminal neuralgia.3If the disease becomes non responsive, there are numerous surgical options like micro vascular decompression or minimally invasive percutaneous lesioning of the trigeminal nerve, such as glycerol rhizolysis, Radiofrequency Rhizotomy, and balloon compression. Objective: - To determine efficacy of percutaneous Radiofrequency Rhizotomy for trigeminal neuralgia in terms of early pain relief in a tertiary care hospital. Methods: -  62 patients with refractory trigeminal neuralgia or lancinating, recurrent episodes of pain in the distribution of Ophthalmic (V1) and Mandibular (V3) branches of trigeminal nerve, not responsive to 6 months of conservative treatment were included. Study was completed in one year i.e. from March 2015 to Feb 2016. Result: - In our study population, 62 included patients were had mean age 56.08 ± 7.39 years. 44 patients (71%) were male. Our treatment was effective in 58 patients (93.5%) while there was recurrence among 4 (6.5%) only. Conclusion: - It is concluded that the efficacy of percutaneous Radiofrequency Rhizotomy for trigeminal neuralgia in terms of complete relief of pain with intact sensations in treated branch region is excellent (93.5%).
Intracranial Low Grade Glioma: a Clinical Study of 35 Cases in a Teaching Institute
Authors: AMIR SOHAIL , ALI GOHAR , MEHMOOD KHALID , HAQ NAEEM-UL
Published: December 2019

Objective: To determine the clinical manifestation and surgical outcome of patients with low grade Glioma.Material and Methods: This descriptive (cross sectional) study was done at the Neurosurgery Department, Mardan Medical Complex Mardan. The study period was March 2017 to February 2018. Patient of any age and gender presented to outpatient department or referred from some other medical facility and diagnosed as low grade Glioma on clinical and radiological grounds and later confirmed by histopathology were included. Results: Out of 35 patients, 20 (57%) were male and 15 (42%) were female. 20 to 80 years was the age range and mean age was 46.36 ± 17.11 years. Frontal lobe was the most frequent area of location, followed by parietal 9 (25%) and temporal 8 (22%) lobe. Pre-operativeKarnofsky score was 90 in 16 (45%), 80 in 8 (22%), 70 in 6 (17%) and 60 in 5 (14%) of patients. Gross total resection was achieved in 13 (37%), radical subtotal resection in 10 (28%), subtotal resection in 10 (28%) and biopsy taken in 02 (5%) patients. histopathology revealed Astrocytoma in 15 (42%), mixed Oligoastrocytoma in 12 (34%) and Oligodendroglioma in 8 (22%) number of patients. Post operatively surgical outcome was measured by improvement in symptomatology, Karnofsky score and seizure control. Conclusion: Conscious level, Karnofsky Performance score, seizure control are important parameters for surgical outcome in patients with low grade Gliomas. Gross total resection of the tumor is a better option for good surgical outcome.
Outcome of Microsurgical Clipping of Ruptured Anterior Circulation Aneurysms
Authors: JAHANGIR KHAN MUHAMMAD , HAMMAD NASIR MUHAMMAD , ALI SIKANDAR , KHAN SARFRAZ , WAQAS MUHAMMAD , AHMED KHAN ZUBAIR
Published: December 2019

Objective: The objective of the study was to analyze the operative outcome of microsurgical clipping in Ruptured Anterior Circulation Aneurysms.Materials and Methods: Twenty patients with Ruptured Anterior Circulation aneurysms were treated with surgical clipping. All the patients were evaluated pre-operatively according to Hunt & Hess and WFNS grading scales. Patients with grade I, II, and III were operated. All the aneurysms were clipped through Pterional approach under General anesthesia and Yasargil Aneurysm clips of appropriate sizes were used in each patient. Outcome was analyzed according to Glasgow Outcome Scale at the end of six months of follow up in each patient.Results: In this series of twenty cases, the mean patient age was 49 years. Lesion location included, the ACA/A. Com 55% (n = 11), the Middle Cerebral artery 25% (n = 5), P. Com 15% (n = 3), Ophthalmic artery 5% (n = 1). Sex distribution, female 55% (n = 11) and male 45% (n = 9). Per-operative complications, rupture of aneurysm 20% (n = 4), and damage to perforating branches of MCA 5% (n = 1). Conclusions: Surgical clipping still is the most efficient treatment of Ruptured Anterior Circulation aneurysm at the beginning of the new millennium. Anterior Communicating Artery is the commonest location of aneurysms. Major determinants of outcome are Hunt & Hess, WFNS grades on admission and the age of the patient.
Visual Improvement after Endoscopic Endonasal Transsphenoidal Excision of Pituitary Gland Tumor
Authors: AHMED KHAN ZUBAIR , SULTAN HABIB , WAQAS MUHAMMAD , KHAN SARFRAZ , AHMED TOQEER , CHAUDHRY ANWAR
Published: December 2019

Objective: To evaluate the frequency of improved visual acuity after Endoscopic Endonasal Transsphenoidal excision of pituitary gland tumor.Study Design: Descriptive case series.Materials and Methods: In our study, Pre-operative visual acuity was noted by using the Snellen’s chart. Then patients underwent pituitary gland excision though Endoscopic Endonasal Transsphenoidal approach under general anesthesia. After surgery, patients were shifted in postsurgical wards and then will be discharged from there and were examinedfor 3 months in OPD. Snellen’s chart was used to evaluate patents for visual acuity after 3 months by an experienced ophthalmologist having at least 4 years residency experience If visual acuity increased ? 1 line, then improved visual acuity was labeled.Results: Improved visual acuity after pituitary gland tumor excision was seen in 59(89.39%) patients. Age and gender of patients did not show any statistically significant association for improved visual acuity.Conclusions: Results of this study showed that pituitary gland tumor excision through Endoscopic Endonasal Transsphenoidal approach is effective in terms of visual acuity improvement. Our main objectives in pituitary surgery are protection and reinstatement of vision and this surgical approach give maximum cover to vision restoration.
Consequences of Streptococcal Pneumoniae Meningitis When it Remains Undiagnosed – Suggested Model of Investigational Process
Authors: ABBAS JAFFRI SAMAR , RIDA E ZEHRA SYEDA , SULTAN SADIA
Published: December 2019

Background: Whenever any patient presents with headache and slightly high total leukocytic counts, the pertinent question gets raised is either prompt lumbar puncture (LP) is indicated or not. Usually patients with bacterial meningitis characteristically exhibit fever, neck rigidity and deranged mental status or headache. In majority of cases the causes are non-infective. Whilst meningococcal meningitis has a distinctive non-blanching rash and is promptly diagnosable from the CSF. Our report describes disease presentation with merely one aspect of the triad for acute bacterial meningitis and it raises query regarding reliance on guidelines based on the triad.
Post Traumatic Mask Face, Diagnostic Dilemma in Bilateral Traumatic Facial Palsy. Case Report
Authors: UD-DIN SHAMS- , AHMAD ISHFAQ
Published: December 2019

Traumatic temporal bone fractures, most of the time presents with complications in the form of cerebrospinal fluid leak, facial nerve injury as it enters the petrous part of temporal bone and also sometimes hearing loss due to concomitant vestibulocochlear nerve injury.2,3,4 Second most vulnerable nerve in head injury is facial nerve, with olfactory nerve being the first, and one reason for this is the tortuous bony course in the skull base and temporal bone.8-12 Evaluating facial nerve injury in head injury patient start with an inspection of the temporal bone for any signs of injury, i.e. laceration or visible auditory cartilage or any hematomas or bruises over mastoid, which is called Battle sign.10-12 Functional testing of facial nerve should be recorded in head injury with temporal bone fracture as soon as possible.1, 3- D CT reconstruction of the skull and temporal bone should be carried out when there is suspicion of facial nerve injury.11,12 Complementary electro diagnostic testing should also be performed in order to assess the severity of facial nerve injury.2,3,4 These all helps in early detection and further management of facial nerve injury.5,6,7,11 We presented a case of 18years old male who had road traffic accident on 29.10.2018. This patient suffered with the head injury with bleeding from nose and right ear.