169 research outputs found
Magnetic Scanometric DNA Microarray Detection of Methyl Tertiary Butyl Ether Degrading Bacteria for Environmental Monitoring
A magnetoresistive biosensing platform based on a single magnetic tunnel junction (MTJ) scanning probe and DNA microarrays labeled with magnetic particles has been developed to provide an inexpensive, sensitive and reliable detection of DNA. The biosensing platform was demonstrated on a DNA microarray assay for quantifying bacteria capable of degrading methyl tertiary butyl ether (MTBE), where concentrations as low as 10 pM were detectable. Synthetic probe bacterial DNA was immobilized on a microarray glass slide surface, hybridized with the 48 base pair long biotinylated target DNA and subsequently incubated with streptavidin-coated 2.8 μm diameter magnetic particles. The biosensing platform then makes use of a micron-sized MTJ sensor that was raster scanned across a 3 mm by 5 mm glass slide area to capture the stray magnetic field from the tagged DNA and extract two dimensional magnetic field images of the microarray. The magnetic field output is then averaged over each 100 μm diameter DNA array spot to extract the magnetic spot intensity, analogous to the fluorescence spot intensity used in conventional optical scanners. The magnetic scanning result is compared with results from a commercial laser scanner and particle coverage optical counting to demonstrate the dynamic range and linear sensitivity of the biosensing platform as a potentially inexpensive, sensitive and portable alternative for DNA microarray detection for field applications
Hybrid GMR Sensor Detecting 950 pT/sqrt(Hz) at 1 Hz and Room Temperature.
Advances in the magnetic sensing technology have been driven by the increasing demand for the capability of measuring ultrasensitive magnetic fields. Among other emerging applications, the detection of magnetic fields in the picotesla range is crucial for biomedical applications. In this work Picosense reports a millimeter-scale, low-power hybrid magnetoresistive-piezoelectric magnetometer with subnanotesla sensitivity at low frequency. Through an innovative noise-cancelation mechanism, the 1/f noise in the MR sensors is surpassed by the mechanical modulation of the external magnetic fields in the high frequency regime. A modulation efficiency of 13% was obtained enabling a final device's sensitivity of ~950 pT/Hz1/2 at 1 Hz. This hybrid device proved to be capable of measuring biomagnetic signals generated in the heart in an unshielded environment. This result paves the way for the development of a portable, contactless, low-cost and low-power magnetocardiography device
Framing and repetition effects on risky choices: A behavioural approach
Framing effects play an important role in individual decision-making under risk. This investigation revisits framing effects caused by two versions of the choice list procedure, lottery vs. lottery (LL) and lottery vs. certainty (LC). In the first, subjects face pairwise choices between lotteries within a choice list. In the second, subjects face pairwise choices between a safe amount and a lottery. In order to measure the sensitivity of subjects’ choices to the structure of the tasks, we implement an incentive-compatible experiment using repetition in order to have a robust measure of the subjects’ propensity to make a choice. Particularly, it is tested whether variations in the number of options offered in a choice list with and without variations in the range of options affect subjects’ choices. Our results suggest that changes in framework disturb subjects’ risk preferences only in the LC version when the range of options presented has been varied
Programa “Fortaleciendo mis emociones” para mejorar las habilidades sociales en estudiantes de una institución educativa de Piura, 2023
El propósito principal de este estudio consistió en determinar si el programa
“fortaleciendo mis emociones” mejora las habilidades sociales en estudiantes del
cuarto grado de secundaria en una institución educativa de Piura 2023. El estudio
se realizó de acuerdo el enfoque cuantitativo, de tipo aplicado y diseño pre
experimental. Antes de la ejecución del programa “fortaleciendo mis emociones”
se aplicó un pre test de habilidades sociales, asimismo se aplicó un post test
después de la aplicación del referido programa para medir resultados. La
población muestra la conformaron 38 estudiantes del cuarto grado sección “C” de
una institución educativa de Castilla – Piura. En el procesamiento de datos se
empleó la estadística descriptiva (porcentajes y frecuencias). En los resultados
descriptivos se evidenció que antes de la aplicación del programa el 100% de los
estudiantes se encontraban en el nivel regular de habilidades sociales. Después
de la aplicación del programa estas habilidades se ubican en el 13.16% buenas y
el 86.84% muy buenas, lo cual evidencia que la aplicación del programa educativo
mejoró significativamente las habilidades sociales en los estudiantes de cuarto
grado “C” en una institución educativa de Piura
Control de calidad de cerámicos con procesamiento digital de Imágenes para reducir costos
El estudio tiene como finalidad desarrollar un sistema de visión por computador (visión artificial) para el control de calidad visual automática de piezas cerámicas, el cual permite una inspección confiable, por tanto, aumenta la productividad, disminuye la posibilidad de errores humanos y evita los costos que conllevan una entrega de producto en malas condiciones.
El trabajo de investigación consta del estudio y desarrollo de un programa en Matlab, el cual procesa imágenes tomadas del cerámico e identifica los defectos de la superficie como: Fisuras, grietas, cuarteos, manchas, bifurcaciones y quiñaduras, además determina el estado final del producto si está en buenas o malas condiciones y se analizará la estimación de reducción de costos del producto; esto se analizará especialmente en cerámicos compactos en la marca San Lorenzo.
Este trabajo de investigación beneficiará principalmente a empresas del sector industrial para elaborar productos que cumplan con las normas establecidas de precisión, desempeño y calidad final del producto cerámico. Así mismo, en aumentar la productividad en el control de calidad de los cerámicos.Trabajo de investigaciónCampus Lima Centr
Simulación Del Movimiento Del Jugo En Un Intercambiador Pirotubular Para La Industria Panelera
This article presents a study to optimize tube configuration in a pirotubular reservoir used in the sugar cane industry. Optimized tube configuration should eliminate problems in the stage of juice clarification (during which juice is heated from 60ºC to 96ºC), and improve panela's quality. This study consists of: a) a mathematical model describing the macroscopic flow of juice, b) a finite-element modelling (FEM) simulation of the microscopic flow, and c) a comparison between results obtained by the two methods. The FEM simulated flow is then applied to several geometric configurations of the tubes in order to optimize tube configuration to provide an improved juice clarification stage. From the configurations tested, semielliptical tubes presented a better performance.
Las competencias profesionales y su efecto en la toma de decisiones de los trabajadores de la empresa Trecor Constructora SAC 2020
El objetivo principal de esta investigación fue determinar cómo influyen las
competencias profesionales en la toma de decisiones de los trabajadores de la
empresa Trecor Constructora SAC, 2020. Por ello, iniciamos describiendo la
realidad problemática la cual fundamenta nuestro interés por estudiar el siguiente
problema ¿ Cómo influyen las competencias profesionales en la toma de decisiones
de los trabajadores de la empresa Trecor Constructora SAC, 2020?, para dicho
problema planteamos la siguiente hipótesis, Las competencias profesionales
influyen significativamente en la toma de decisiones de los trabajadores de la
empresa Trecor Constructora SAC, 2020. La investigación es de tipo básica
correlacional, la población estuvo conformada por los 83 trabajadores de la
empresa a los cuales se les aplicó como instrumento un cuestionario, para el
desarrollo de esta tesis se plantearon los siguientes objetivos, determinar el nivel
de las competencias profesionales de los trabajadores de la empresa Trecor
Constructora SAC, 2020, identificar el nivel de conocimiento y criterio en la toma de
decisiones de los trabajadores de la empresa Trecor Constructora SAC, 2020 y
conocer cuál es la relación entre la variable competencias profesionales y la toma
de decisiones. Finalmente, se llegó a la conclusión de que las competencias
profesionales influyen significativamente en la toma de decisiones de los
trabajadores de la empresa Trecor Constructora SAC, 2020; puesto que aplicada
la prueba de chi-cuadrado arrojó un valor p resultó en 0.000 < 0.05, por lo tanto, se
aceptó la hipótesis planteada.The main objective of this research was to determine how professional
competencies influence the decision-making of the workers of the company Trecor
Constructora SAC, 2020. Therefore, we begin by describing the problematic reality
which bases our interest in studying the following problem. Do professional
competencies influence the decision-making of the workers of the company Trecor
Constructora SAC, 2020, for this problem we propose the following hypothesis,
Professional competencies significantly influence the decision-making of the
workers of the company Trecor Constructora SAC, 2020. The research is of a basic
correlational type, the population was made up of the 83 workers of the company to
whom a questionnaire was applied as an instrument, for the development of this
thesis the following objectives were proposed, to determine the level of
competencies professional company workers resa Trecor Constructora SAC, 2020,
identify the level of knowledge and criteria in the decision-making of the workers of
the company Trecor Constructora SAC, 2020 and know what is the relationship
between the variable professional competencies and decision-making. Finally, it
was concluded that professional skills significantly influence the decision-making of
the workers of the company Trecor Constructora SAC, 2020; since applied the chisquare test, it yielded a p-value that resulted in 0.000 <0.05, therefore, the proposed
hypothesis was accepted.Tesi
Risk attitude elicitation using a multi-lottery choice task: Real vs. hypothetical incentives
We present a bi-dimensional multi lottery choice task which can be used in order to elicit the agents' risk attitudes in financial environments. This task is implemented both with hypothetical and real monetary incentives in a between-subjects and a within-subjects experiment. We observe choices involving significantly lower risk aversion on aggregate when incentives are real. The differences grow with the stakes at play. We also obtain significant differences between hypothetical and real rewards in both utility weighting and probability weighting estimated parameters. We find that the use of hypothetical incentives in multi-lottery choice tasks for evaluating individual risk aversion can be misleading
Individual Characteristics vs. Experience: An Experimental Study on Cooperation in Prisoner's Dilemma
Cooperative behavior is often assumed to depend on individuals’ characteristics, such
as altruism and reasoning ability. Evidence is mixed about what the precise impact
of these characteristics is, as the subjects of study are generally randomly paired,
generating a heterogeneous mix of the two characteristics. In this study we ex-ante
create four different groups of subjects by factoring their higher or lower than the median
scores in both altruism and reasoning ability. Then we use these groups in order to
analyze the joint effect of the two characteristics on the individual choice of cooperating
and on successful paired cooperation. Subjects belonging to each group play first 10
one-shot prisoner’s dilemma (PD) games with ten random partners and then three
consecutive 10-round repeated PD games with three random partners. In all games,
we elicit players’ beliefs regarding cooperation using an incentive compatible method.
Individuals with high altruism are more optimistic about the cooperative behavior of the
other player in the one-shot game. They also show higher individual cooperation and
paired cooperation rates in the first repetitions of this game. Contrary to the one-shot
PD games where high reasoning ability reduces the probability of playing cooperatively,
the sign of the relationship is inverted in the first repeated PD game, showing that
high reasoning ability individuals better adjust their behavior to the characteristics of the
game they are playing. In this sense, the joint effect of reasoning ability and altruism
is not linear, with reasoning ability counteracting the cooperative effect of altruism in
the one-shot game and reinforcing it in the first repeated game. However, experience
playing the repeated PD games takes over the two individual characteristics in explaining
individual and paired cooperation. Thus, in a (PD) setting, altruism and reasoning ability
significantly affect behavior in single encounters, while in repeated interactions individual
and paired cooperation reach similarly high levels independently of these individual
characteristics.Financial support by Universitat Jaume I (project P1.1B2015-
48) and the Spanish Ministry of Economics and Competitiveness
(projects ECO2013-44409-P and ECO2015-68469-R) is gratefully
acknowledged
Oxidación cíclica a alta temperatura de un recubrimiento de aluminio depositado sobre un astm a53 grado b
Probetas de acero ASTM A53 grado B fueron recubiertas con metcoloy por rociado térmico por arco eléctrico EATS (por sus siglas en inglés), y
sometidas a la prueba experimental de oxidación cíclica a 500°C y 700°C, con el fin de estudiar su comportamiento protector contra la oxidación a altas temperaturas. Se estudió la formación de óxidos por medio de la técnica de varianza de masa y también se analizó por medio de Microscopía Óptica(OM) y Microscopía Electrónica de Barrido (SEM) ..
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