289,412 research outputs found
A facile and sensitive video-analysis method for tracking floating lag-time and floating rate of gastro-retentive tablets
No full textFloating effervescent tablets are designed to rapidly float in the gastric fluids by gas formation, after an initial lag-time. We developed here a method to characterise these dosage forms. Tablets were prepared containing various concentrations of hydroxypropyl methylcellulose (HPMC), dicalcium phosphate (DCP) and sodium bicarbonate (NB) as gelling agent, high-density model compound and gassing agent, respectively. Videos of the motion of tablets exposed to fluids for 6 h were recorded and then analysed to measure: i) tablet swelling; ii) floating kinetic until lag-time and iii) residual floating rate of the tablets over time. The developed technique was able to precisely track tablet motion and thus describe the floating performance of the dosage forms. Specifically, it was found that floating lag-time and floating fluctuations were influenced by the concentration of NB, more than DCP. Moreover, both swelling volume and residual floating rate over time were not affected by tablet composition, suggesting that density developments of the tablets were similar across formulations. Floating rate also remained constant over the test duration, which correlates well with previous findings on the floating force of HPMC/NB matrices. Overall, we showcase here a simple video-recording and -analysis technique to effectively characterise the performance of floating dosage forms
A survey and comparison of leading-edge uncertainty handling methods for power grid modernization
No full textThe power grid infrastructure encounters multiple uncertainties such as unprecedented energy generation from non-dispatchable resources, erratic load, intensifying energy demand, the transition towards electric mobility, and the electricity market that exaggerate the decision-maker's difficulties in the power system. How to deal with massive real-time uncertain data is a pressing and challenging issue. To date, the art to tackle contingencies and ambiguous events has globally advanced and attained great assiduity, whereas, substantial work has been conducted on the optimization problems under uncertainties. In this regard, a comprehensive review of contemporary research is presented to identify future research trends. Moreover, the literature on the state-of-the-art uncertainty modeling methods is scrutinized, whilst a comparative assessment is stated to provide a broader overview evidencing that, so far, there is no particular preeminent uncertainty handling technique. The presented work may be adopted for the selection of the most suitable methodology in each application. In comparison to traditional approaches, robust optimization is one of the recent and adaptive uncertainty handling techniques for optimization problems owing to its salient features. Furthermore, its contributions in five crucial categories of power grid optimization problems are reviewed to highlight additional challenges and the scope of future research in the context of envisioned power networks
Ustad Rahim. Heart’s Rubab Maestro
No full textShot in the city of Heart, western Afghanistan 1994, in the period between the fall of the last leftist government and the coming of the Taliban, this is a portrait film of an outstanding musician, Ustad Rahim Khushnawaz. He was a master of the Afghan rubab, a double-chambered plucked lute with sympathetic strings. Using the observational cinema style the film shows Ustad Rahim in various contexts. These include a guided tour of the photos in his music room that recount his musical career, being at home with his wife and children, showing off his pigeons, erecting the tombstone for his father’s grave, and teaching and playing the rubab. Of particular interest is the gormani ritual, a gathering of musicians where Rahim accepts a new student
Evaluation of turbulence models for the prediction of flow properties in vegetated channels
No full textThe performance of turbulence models was investigated to predict the flow and turbulence features of the vegetated channel using computational fluid dynamics (CFD). The Ansys Fluent, CFD software was implemented for the numerical studies. The flow was three-dimensional, incompressible, steady, and turbulent. Ten turbulence models, provided by Ansys Fluent, were implemented for the comparative study. The numerical model was validated against an experimental study conducted in the literature. The numerical studies show that the Renormalization group k-ϵ model is the most successful model for predicting the flow characteristics of the vegetated channel with a Root Mean Square Error (RMSE) value of 0.2752. At the same time, the Reynolds Stress Model gives the least successful predictive performance, indicated by an RMSE value of 0.4302. Moreover, the Spalart-Allmaras (S-A) model offers the shortest computation time with a value of 6652.393 s, whereas the Shear Stress Transport k-ω model proves to be the most time-consuming with a value of 11 952.219 s. The velocity of water flow in a channel is not uniform as it is slower at the surface of leaves and faster in the free zones. The maximum velocity is observed in the middle section of the channel, below the leaf, and between the roots with the value of u = 0.1158 m/s. Furthermore, the characteristics of turbulence in a channel are influenced by several factors such as channel geometry, flow velocity, and vegetation distribution. As a result, the presence of vegetation in a channel affects the flow and turbulence characteristics of the water significantly. © 2024 Author(s)
Fleshy seeds form in the basal Angiosperm Magnolia grandiflora and several MADS-box genes are expressed as fleshy seed tissues develop
No full textOne successful mechanism of seed dispersal in plants involves production of edible fleshy structures which attract frugivorous animals and transfer this task to them. Not only Angiosperms but also Gymnosperms may use the fleshy fruit habit for seed dispersal, and a similar suite of MADS-box genes may be expressed as these structures form. Magnolia grandiflora produces dry follicles which, at maturity, open to reveal brightly colored fleshy seeds. This species thus also employs endozoochory for seed dispersal, although it produces dry fruits. Molecular analysis reveals that genes involved in softening and color changes are expressed at late stages of seed development, when the fleshy seed sarcotesta softens and accumulates carotenoids. Several MADS-box genes have also been studied and results highlight the existence of a basic genetic toolkit which may be common to all fleshy fruit-like structures, independently of their anatomic origin. According to their expression patterns, one of two AGAMOUS genes and the three SEPALLATA genes known so far in Magnolia are of particular interest. Duplication of AGAMOUS already occurs in both Nymphaeales and Magnoliids, although the lack of functional gene analysis prevents comparisons with known duplications in the AGAMOUS lineage of core Eudicots
Haciendo palabra: la poesía de Jennifer Rahim. (Traducción: Andrés Seijas).
No full textThe relationship of Jennifer¿s work Rahim with Julia Kristeva¿s ideas about the maternity in their titled works El tiempo de las mujeres and Stabat Mater constitutes a true source for the recognition of the gender, in the sense that both they are focused in the woman¿s essential aspects: as their ancestral paper in the development of the life or the inclusion of this in topics as the writing. In this sense, the present work looks for to determine the nexuses of Jennifer Rahim¿s work about the feminine writing, which is a reality that every time charges bigger value and transcendency in the literature. This topic outlines the women writers an exercise of permanent reflection. For this analysis we are based on some books of poetry of Rahim and the opinion that some critics have about these worksLa relación del trabajo de Jennifer Rahim con las ideas de Julia Kristeva sobre la maternidad en sus trabajos titulados El tiempo de las mujeres y Stabat Mater constituye una verdadera fuente para el reconocimiento del género, en el sentido de que ambos se enfocan en aspectos esenciales de la mujer, como su papel ancestral en el desarrollo de la vida o la inclusión de ésta en tópicos como la escritura. En este sentido, el presente trabajo busca desentrañar los vasos comunicantes del trabajo de Jennifer Rahim con una realidad que cada vez cobra mayor valor en la literatura, con particular trascendencia; la escritura femenina. Cabe señalar que, este tema les plantea a las mujeres escritoras un ejercicio de permanente reflexión. Para este análisis nos valemos de algunos libros de poesía de Rahim y la visión que algunas críticas dan de estos trabajos
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Impact of tree training system, branch type and position in the canopy on the ripening homogeneity of abate pear fruit
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