3,035 research outputs found
Generating and using truly random quantum states in Mathematica
The problem of generating random quantum states is of a great interest from
the quantum information theory point of view. In this paper we present a
package for Mathematica computing system harnessing a specific piece of
hardware, namely Quantis quantum random number generator (QRNG), for
investigating statistical properties of quantum states. The described package
implements a number of functions for generating random states, which use
Quantis QRNG as a source of randomness. It also provides procedures which can
be used in simulations not related directly to quantum information processing.Comment: 12 pages, 3 figures, see http://www.iitis.pl/~miszczak/trqs.html for
related softwar
Generating Multimode Entangled Microwaves with a Superconducting Parametric Cavity
In this Letter, we demonstrate the generation of multimode entangled states
of propagating microwaves. The entangled states are generated by parametrically
pumping a multimode superconducting cavity. By combining different pump
frequencies, applied simultaneously to the device, we can produce different
entanglement structures in a programable fashion. The Gaussian output states
are fully characterized by measuring the full covariance matrices of the modes.
The covariance matrices are absolutely calibrated using an in situ microwave
calibration source, a shot noise tunnel junction. Applying a variety of
entanglement measures, we demonstrate both full inseparability and genuine
tripartite entanglement of the states. Our method is easily extensible to more
modes.Comment: 5 pages, 1 figures, 1 tabl
Platooning of connected automated vehicles on freeways: a bird’s eye view
A platoon of connected automated vehicles (CAVs) is defined as a group of CAVs that exchange information, so that they can drive in a coordinated way, allowing very small spacings and, still, travelling safely at relatively high speeds. The concept of vehicle platooning is not new. Scientific articles on platooning have been published since the 1970s, and the first large-scale pilot test on vehicle platooning was carried out in the mid 1990s in California. By 1992, the first vehicle platooning experiments were successfully concluded, and the four-vehicle platoon capability was demonstrated for visitors on the I-15 HOV lanes in San Diego in 1994. The main purpose of these early research works was to improve traffic efficiency and reduce vehicle consumption, as well as to develop the existing technology, which represented a strong limitation at the time. Precisely, the development of new technologies and communications in the last decade has given a new impetus to the research on vehicle platooning on freeways, as one of the most promising forms of cooperation among CAVs. These recent studies have extended the analysis beyond traffic efficiency, including safety, sustainability, business productivity, among other objectives. In this context, today, there are many scientific publications on vehicle platooning with different purposes, scopes, scenarios, and based on a wide diversity of vehicles and technologies (i.e. regular or segregated lanes, cars or trucks, vehicles with different SAE levels, etc.). In order to organize and consolidate the existing knowledge on the field, a comprehensive and systematic review must be performed. The present work represents a first approach to this ambitious objective. First, platooning is conceptualized in order to facilitate its analysis and comparison among studies. Second, key publications on platooning are analyzed to determine the most significant impacts that can be expected from its implementation. Finally, some important research gaps and disparate findings on the topic are identified.This research has been partially funded by the Spanish Ministry of Economy, Industry and Competitiveness, within the National Program for Research Aimed at the Challenges of Society (grant ref. PID2019-105331RB-I00).Peer ReviewedPostprint (published version
Durabilidad del hormigón frente a los ciclos hielo-deshielo. Evaluación de dos tipos de hormigón.
El presente trabajo estudia el comportamiento de dos hormigones frente al ensayo de resistencia al hielo-deshielo de hormigones endurecidos. La incorporación de un aditivo aireante mejora de forma sensible el comportamiento del hormigón frente a este ensayo. Sin embargo, en hormigón pretensado con cordón adherente está prohibido el uso de aditivos aireantes. Una estrategia adecuada es emplear humo de sílice para mejorar la impermeabilidad del hormigón. En este trabajo se compara el comportamiento de un hormigón con aditivo aireante y otro con humo de sílice frente al ensayo de resistencia al hielo-deshielo. Además, estudia la viabilidad de emplear técnicas alternativas de medida del deterioro superficial: modificación de la velocidad de pulso ultrasónico y medida de la deformación superficial con galgas extensométricas. Ambas técnicas se muestran viables y aportan ventajas frente al peso de la masa superficial desprendida por descascarillamient
Associated factors, inequalities, and spatial distribution of the use of modern contraceptive methods among women of reproductive age in Peru: a population-based cross-sectional study
Background: The use of contraceptive methods in Peru has remarkably increased in recent decades. Nevertheless, despite the completeness and accessibility of family planning methods, modern contraceptive methods utilization in Peru remains below the South American average. Thus, this study aimed to elucidate the factors associated with modern contraceptive use, as well as the presence of inequalities and the spatial distribution in Peruvian women aged 15–49 years in 2019. Methods: A secondary data analysis was conducted using information from the 2019 Peruvian Demographic and Health Survey. We performed descriptive statistics, bivariate analysis, and Poisson multiple regression. Inequalities were estimated through concentration curves and Erreygers’ normalized concentration index. Spatial analysis included choropleth map, Global Moran’s I, Kriging interpolation and Getis-Ord-Gi* statistic. Results: The prevalence of modern contraceptive use was 39.3% among Peruvian women of reproductive age. Modern contraceptive use was directly associated with youth (aPR 1.39), women having their first sexual intercourse before the age of 18 (aPR 1.41), and being married but not together (aPR 1.87). In addition, speaking Quechua or Aymara (aPR 0.87) and having no children (aPR 0.59) were inversely associated with utilization of modern contraceptives. We found the presence of inequalities in the use of contraceptive methods (pro-rich distribution), although the magnitude was low. Spatial analysis unveiled the presence of a clustered distribution pattern (Moran’s Index = 0,009); however, there was inter-departmental and intra-departmental heterogeneity in the predicted prevalence of the use of modern contraceptives. In addition, significant hot and cold spots were found in Peru. Conclusion: Two out of five Peruvian women of reproductive age used modern contraceptives. It was associated with younger women’s age, younger age at first sexual intercourse, being married or cohabitant, among others. No substantial inequality was found in modern contraceptive use. The prevalence was heterogeneous at the intra- and inter-departmental level. Those departments located in the south, south-east, and north-east had the lowest prevalence. Therefore, nonfinancial barriers must be tackled through multi- and cross-sectoral efforts and continue to universally provide modern contraceptives.Revisión por pare
INFLUENCIA ANTRÓPICA EN UN ACUÍFERO COSTERO. CONSIDERACIONES SOBRE LA GESTIÓN HÍDRICA DEL ACUÍFERO DE MOTRIL-SALOBREÑA (ESPAÑA)
El acuífero costero de Motril-Salobreña -Granada, España- está formado por
depósitos aluviales y piedemontes. El río Guadalfeo drena la vertiente sur de
Sierra Nevada y atraviesa e influye notoriamente al acuífero. La construcción de la
presa de Rules, situada aguas arriba del acuífero, producirá una alteración en el
caudal y el flujo circulante por el aluvial del río. La agricultura es la actividad
preponderante en la zona. En general, el riego se realiza con aguas del
Guadalfeo, la abundancia del recurso favorece la aplicación de dotaciones altas y
el desinterés por emplear técnicas de ahorro hídrico. Los retornos de regadío
representan un tercio de la recarga media del acuífero, correspondiendo otro tercio
a la recarga inducida por bombeos en las márgenes del río. La actividad humana
es un factor esencial en el sistema acuífero al propiciar las recargas más
importantes. El IGME analizó en primera aproximación, mediante un modelo
numérico, el impacto que en el acuífero ocasionará la presa de Rules. Este trabajo
complementa y es una extensión de aquel estudio y analiza el impacto que sobre
el acuífero produciría una modificación en la actividad agrícola. Este será aún
mayor al producido por la presa.
ABSTRACT
The Motril- Salobreña coastal aquifer -Granada, Spain- is constituted by alluvial
and piedemontite deposits. The Guadalfeo river is the most important stream in the
area and has a great influence on the groundwater system. The building of the
Rules dam will cause a strong modification on the Guadalfeo flow regime and on
the alluvial runoff whatever the conjunctive use scheme is defined in the future.
Agriculture is very important in the regional economy. The irrigation uses
exclusively water from the Guadalfeo river; surface water abundance has permitted
the use of high application rates with significant returns associated. The anthropic
action is an important factor in this groundwater system, because it generates the
greatest aquifer recharge: irrigation returns and induced recharge from the river.
IGME studied the impact of the Rules dam on the aquifer using a numeric model.
This paper complements and is the continuation of that first study. This work
studies the impacts on the aquifer if the agricultural activities are modified. Such
impacts will be more important than the ones created by the dam construction
DIAGNÓSTICO NUTRICIONAL DE NIÑOS ENTRE 3 Y 5 AÑOS QUE ASISTEN AL JARDÍN INFANTIL “LA GOTITA” DE PUERTO MONTT, DURANTE EL PRIMER SEMESTRE DEL AÑO 2006. VALDIVIA. CHILE
Infantile obesity is an important problem of public health whose prevention measures should start in the early stages of life, where parents should be involved. If parents are not able to detect overweight or obesity in their own children, measures carried out to prevent the infantile obesity will be hardly successful.
Te aim of the present quantitative, cross-section, and descriptive investigation, not experimental, was to determine the nutritional state of children that attend the Kindergarten La Gotita, in Puerto Montt, during the first semester of 2006, regarding age, gender, weight and size.
The studied population, after having applied exclusion criteria, was constituted by 107 children, of which 56% were men and the remaining 44% were women. According to nutritional state, by age, children in risk of undernourished were 8% and it decreased to 0% at the age of 5. Within this group of children in risk of undernourished, none of them presented size deficit. Additionally, the children with overweight dropped from 14% in March to 9% in July, obese children also dropped from 10% in March to 9% in July. Overweight was observed in all ages in both genders and a deficit in children of 3 and 4 years old in both genders.
The proportion of obese women was higher than in men in every month of the study and at all ages.
Less than half (20%) of obese children’s parents did not presented chronic illnesses no-communicable, risk factors, considered inside the norm of outpatient handling with overweight due to undernourishment. Therefore, it is extremely important while evaluating an obese child.
The children of this study, at all ages and in both genders have high percentages of overweight and obesity. Less than half (7.4%) that is managed at national level, thus it becomes necessary to adopt preventive measures from an early age such as, motivating mothers to maintain their children controlling their health constantly during the previous preschool years, developing specific educational programs about appropriate feeding for each age, promoting healthy habits, and avoiding little physical activity, since those factors may lead to complications in the adulthood.La obesidad infantil es un problema importante de salud pública cuyas medidas de prevención deben iniciarse en etapas tempranas de la vida, en las que deben involucrarse los padres. Si éstos no son capaces de percibir el sobrepeso o la obesidad en sus hijos preescolares, difícilmente las medidas destinadas a prevenir la obesidad infantil podrán tener éxito.
La presente investigación cuantitativa, transversal, descriptiva, no experimental, buscó determinar el estado nutricional de los niños que asisten al Jardín Infantil La Gotita, de Puerto Montt, durante el primer semestre del año 2006, en relación a la edad, sexo, peso y talla.
La población en estudio, luego de aplicar criterios de exclusión, quedó conformada por 107 niños, de los cuales el 56% corresponde a hombres y el restante 44% a mujeres. Según estado nutricional, por año de edad, los niños en riesgo de desnutrir son el 8% y disminuyen a 0% a los 5 años. De este grupo de niños con riesgo de desnutrir, ninguno presentaba déficit de talla. Los niños con sobrepeso disminuyen de 14% en marzo, a un 9% en julio; los niños obesos también disminuyen de 10% en marzo, a 9% en julio. Se observa exceso de peso en todas las edades en ambos sexos. Y déficit en niños de 3 a 4 años, también en ambos sexos.
La proporción de mujeres con obesidad es mayor que la de los hombres, en todos los meses del estudio y en todas las edades.
El 20% de los padres de niños obesos, presentó enfermedades crónicas no transmisibles, factores de riesgo considerados dentro de la norma para el “manejo ambulatorio de la malnutrición por exceso” del ministerio y, por lo tanto, muy importante en el momento de evaluar a un niño obeso.
Por lo que se refiere a los niños de este estudio, en todas las edades y en ambos sexos encontramos alta prevalencia de sobrepeso y obesidad, por sobre el 7.4% que se maneja a nivel nacional, lo que amerita adoptar medidas preventivas desde temprana edad: incentivar a las madres a mantener a sus hijos en control de salud constante durante la etapa preescolar; desarrollar programas educativos específicos sobre alimentación adecuada para cada edad; fomentar hábitos saludables y evitar el sedentarismo, ya que ellos, son factores conducentes a complicaciones en la edad adulta
Covariant derivative of the curvature tensor of pseudo-K\"ahlerian manifolds
It is well known that the curvature tensor of a pseudo-Riemannian manifold
can be decomposed with respect to the pseudo-orthogonal group into the sum of
the Weyl conformal curvature tensor, the traceless part of the Ricci tensor and
of the scalar curvature. A similar decomposition with respect to the
pseudo-unitary group exists on a pseudo-K\"ahlerian manifold; instead of the
Weyl tensor one obtains the Bochner tensor. In the present paper, the known
decomposition with respect to the pseudo-orthogonal group of the covariant
derivative of the curvature tensor of a pseudo-Riemannian manifold is refined.
A decomposition with respect to the pseudo-unitary group of the covariant
derivative of the curvature tensor for pseudo-K\"ahlerian manifolds is
obtained. This defines natural classes of spaces generalizing locally symmetric
spaces and Einstein spaces. It is shown that the values of the covariant
derivative of the curvature tensor for a non-locally symmetric
pseudo-Riemannian manifold with an irreducible connected holonomy group
different from the pseudo-orthogonal and pseudo-unitary groups belong to an
irreducible module of the holonomy group.Comment: the final version accepted to Annals of Global Analysis and Geometr
Analysis of al-2 Mutations in Neurospora
The orange pigmentation of the fungus Neurospora crassa is due to the accumulation of the xanthophyll neurosporaxanthin and precursor carotenoids. Two key reactions in the synthesis of these pigments, the formation of phytoene from geranylgeranyl pyrophosphate and the introduction of β cycles in desaturated carotenoid products, are catalyzed by two domains of a bifunctional protein, encoded by the gene al-2. We have determined the sequence of nine al-2 mutant alleles and analyzed the carotenoid content in the corresponding strains. One of the mutants is reddish and it is mutated in the cyclase domain of the protein, and the remaining eight mutants are albino and harbor different mutations on the phytoene synthase (PS) domain. Some of the mutations are expected to produce truncated polypeptides. A strain lacking most of the PS domain contained trace amounts of a carotenoid-like pigment, tentatively identified as the squalene desaturation product diapolycopene. In support, trace amounts of this compound were also found in a knock-out mutant for gene al-2, but not in that for gene al-1, coding for the carotene desaturase. The cyclase activity of the AL-2 enzyme from two albino mutants was investigated by heterologous expression in an appropriately engineered E. coli strain. One of the AL-2 enzymes, predictably with only 20% of the PS domain, showed full cyclase activity, suggesting functional independence of both domains. However, the second mutant showed no cyclase activity, indicating that some alterations in the phytoene synthase segment affect the cyclase domain. Expression experiments showed a diminished photoinduction of al-2 transcripts in the al-2 mutants compared to the wild type strain, suggesting a synergic effect between reduced expression and impaired enzymatic activities in the generation of their albino phenotypes
Experimental Investigation of Metal-Based Calixarenes as Dispersed Catalyst Precursors for Heavy Oil Hydrocracking
Slurry-phase hydrocracking utilizing metal-containing oil-soluble compounds as precursors of dispersed catalysts is an effective approach for heavy oil upgrading. We propose applying metal-based p-tert-butylcalix[6]arene (TBC[6]s) organic species as dispersed catalyst precursors to enhance catalytic hydrogenation reactions involved in the upgrading of vacuum gas oil (VGO). Co- and Ni-based TBC[6]s were synthesized and characterized by SEM-EDX, ICP, XRD, and FT-IR. The thermogravimetric and calorimetric behaviors of the synthesized complexes, which are key properties of dispersed hydrocracking catalysts, were also explored. The experimental evaluation of the synthesized catalyst precursors show that the synthesized metal-based TBC[6] catalyst precursors improved the catalytic hydrogenation reactions. A co-catalytic system was also investigated by adding a commercial, first-stage hydrocracking supported catalyst in addition to the dispersed catalysts. The naphtha yields increased from 10.7 wt.% for the supported catalyst to 11.7 wt.% and 12 wt.% after adding it along with Ni-TBC[6] and Co-TBC[6], respectively. Mixing the metal-based precursors resulted in elevated yields of liquid products due to the in situ generation of highly active Co–Ni bimetallic dispersed catalysts.This research was funded by Deanship of Research Oversight and Coordination (DROC) at King Fahd University of Petroleum and Minerals (KFUPM), grant number DF181018
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