Electron-correlation driven capture and release in double quantum dots

We recently predicted that the interatomic Coulombic electron capture (ICEC) process, a long-range electron correlation driven capture process, is achievable in gated double quantum dots (DQDs). In ICEC an incoming electron is captured by one QD and the excess energy is used to remove an electron from the neighboring QD. In this work we present systematic full three-dimensional electron dynamics calculations in quasi-one dimensional model potentials that allow for a detailed understanding of the connection between the DQD geometry and the reaction probability for the ICEC process. We derive an effective one-dimensional approach and show that its results compare very well with those obtained using the full three-dimensional calculations. This approach substantially reduces the computation times. The investigation of the electronic structure for various DQD geometries for which the ICEC process can take place clarify the origin of its remarkably high probability in the presence of two-electron resonances

Controlled energy-selected electron capture and release in double quantum dots

Highly accurate quantum electron dynamics calculations demonstrate that energy can be efficiently transferred between quantum dots. Specifically, in a double quantum dot an incoming electron is captured by one dot and the excess energy is transferred to the neighboring dot and used to remove an electron from this dot. This process is due to long-range electron correlation and shown to be operative at rather large distances between the dots. The efficiency of the process is greatly enhanced by preparing the double quantum dot such that the incoming electron is initially captured by a two-electron resonance state of the system. In contrast to atoms and molecules in nature, double quantum dots can be manipulated to achieve this enhancement. This mechanism leads to a surprisingly narrow distribution of the energy of the electron removed in the process which is explained by resonance theory. We argue that the process could be exploited in practice.Comment: Lette

Ecophysiological and agronomic response of Abaca (Musa textilis) to different resource conditions in Leyte Island, Philippines

Abaca (Musa textilis Née) is closely related to edible bananas (Musa acuminata Colla and M. balbisiana Colla). Abaca usually thrives in the shade beneath tall trees, especially important for protecting the young plants from the sun and the older, taller plants from wind breakage. However, there is still disagreement on the need for shade trees in abaca cultivation. Hence, this study was conducted to ascertain the ecophysiological and agronomic response of abaca grown in different shade conditions, water and nutrient management systems in Leyte Island, Philippines. The objectives of the study were to: (a) explore the influence of shade and irrigation-fertilization on the morphological and physiological performance of abaca; (b) investigate the effect of reducing light intensities by 30%, 40% and 50% of full sunlight on fiber yield and fiber quality; (c) determine the optimum light requirement of abaca plants to attain the optimum yield without affecting the quality of the fiber for industrial use; (d) examine the effect of shade and irrigation-fertilization on biomass production and allocation as well as on NPK absorption and distribution among abaca organs; and (e) find out if irrigation and fertilization could offset the effect of shade on biomass production, NPK absorption and fiber yield of abaca. Field trials were established where light infiltration was reduced by 30%, 40%, and 50% of full sunlight using polypropylene shade nets. Irrigation was applied at a rate of 5 liters plant-1 application-1 day-1. The frequency of irrigation was applied two times per day at seedling stage (1-3 months after planting), three times at the early vegetative stage (4-6 MAP), four times at the late vegetative stage (7-9 MAP), and five times at flagleaf stage (10-12 MAP). On the other hand, placement application of N, P2O5, K2O using complete fertilizer was done at 14 g plant-1 in every three months for the first six months and was increased to 40 g plant-1 in every three months for the next six months after planting. The results of this study showed that plant height, cumulative leaf area, pseudostem length and base girth of abaca significantly improved when the light was further reduced to 50%. The application of NPK fertilizer and combination of irrigation-fertilization further enhanced the growth performance of abaca. Statistical analysis showed that shade, NPK fertilization and combination of irrigation-fertilization positively affected dry matter production, crop growth rate, leaf area ratio and net assimilation rate from seedling to flagleaf stage. Furthermore, biomass allocation and NPK distribution among abaca organs was significantly affected by high radiation and/or temperature at seedling and early vegetative stages, and differential leaf senescence at flagleaf stage where shade plays a considerable function. The amount of NPK absorbed by each organ was influenced by the growth made during the different stages of crop development. Meanwhile, irrigation and fertilizer application further improved biomass allocation that considerably increased NPK absorption and distribution among plant parts. With regards to agronomic response, the abaca planted under different light regimes showed that 50% shade had significantly higher fiber yield compared to those that were under other light treatments since the plants pseudostem under such treatment were longer, bigger and heavier. The combination of irrigation and fertilization could further enhance fiber yield to as much as 141% (compared to the control) but this was not enough to offset the effects of shade on the physiological performance of the plant which significantly increased fiber yield to as much as 265% (compared to the control). Statistical analysis showed that shade and irrigation-fertilizer application had no significant effect on fiber fineness and tensile strength. The superior productivity of abaca in response to shade was due to the avoidance of photoinhibition and photooxidative damage that negatively affected the abaca grown under full sunlight at seedling and early vegetative stage. Likewise, the detrimental effect of photoinhibition on the photosynthetic capacity of abaca grown in full sunlight significantly decreased biomass production and allocation among abaca organs. The amount of NPK absorbed by each organ was influenced by high radiation causing photooxidative damage at seedling stage and differential leaf senescence at flagleaf stage. This significantly affected the pattern of biomass allocation and NPK distribution among abaca plant organs. On the other hand, the application of fertilizer considerably enhanced biomass production but did not change the usual pattern of biomass and NPK distribution. The results showed that irrigation and fertilizer application cannot offset or equalize the positive effect of shade on the vegetative growth, physiological performance, and NPK absorption among plant organs.Abaca (Musa textilis Née) ist nahe verwandt mit den Essbananen (Musa acuminata Colla und M. balbisiana Colla) und im Unterwuchs des tropischen, immergrünen Flachland-Regenwaldes auf den Philippinen heimisch. Abaca gedeiht normalerweise im Schatten unter großen Bäumen, was vor allem den jungen Pflanzen Schutz vor Sonneneinstrahlung bietet und ältere, größere Pflanzen vor Windbruch schützt. Dennoch ist die Notwendigkeit schattenspendender Bäume für den Anbau von Abaca umstritten. Aufgrund dessen wurde in der vorliegenden Arbeit primär der Einfluss der Beschattung auf ökophysiologische und argonomische Parameter von Abaca untersucht, aber auch der Einfluss des Nährstoff- und Wassermanagements. Die Versuche wurden als Freilandstudien auf der Insel Leyte, Philippinen, durchgeführt. Die spezifischen Fragestellungen der Arbeit lauteten: (a) Einfluss der Beschattung, der Bewässerung und der Düngung auf morphologische und physiologische Eigenschaften von Abaca; (b) Einfluss der Lichtintensität (50, 60, 70 und 100 % volles Sonnenlicht) auf Faserertrag und -qualität; (c) Ermittlung der optimalen Lichtbedürfnisse von Abaca-Pflanzen für eine optimale Ertragsleistung bei gleichbleibender Faserqualität für industrielle Nutzung; (d) Einfluss der Beschattung, der Bewässerung und der Düngung auf die Biomasseproduktion und -verteilung sowie die NPK-Absorption und -Verteilung zwischen Pflanzenorganen; und (e) Inwieweit durch Bewässerung und Düngung der Einfluss der Beschattung auf die Biomasseproduktion, die NPK-Absorption und den Faserertrag von Abaca kompensiert werden kann. Zur Klärung dieser Fragestellungen wurden Feldversuche durchgeführt bei denen die Belichtung der Abaca-Bestände durch Sonnenlicht mit Beschattungsnetzen um 30, 40 und 50 % reduziert wurde. Die Bewässerungsintensität betrug 5 L Pflanze-1 Applikation-1 und es wurde im Keimlingsstadium [1-3 Monate nach Pflanzung (MNP)] zweimal pro Tag bewässert, im frühen vegetativen Stadium (4-6 MNP) dreimal pro Tag, im späten vegetativen Stadium (7-9 MNP) viermal pro Tag und im Fahnenblattstadium (10-12 MNP) fünfmal pro Tag. Die Düngung mit N, P2O2 und K2O wurde als NPK-Volldüngung alle drei Monate durchgeführt mit 14 g Pflanze-1 für die ersten sechs Monate nach der Pflanzung und anschließend mit 40 g Pflanze-1. Die Untersuchungen zeigten, dass die Höhe der Abaca-Pflanzen, die kumulierte Blattfläche sowie die Länge und der Umfang des Scheinstamms signifikant erhöht waren wenn die Intensität des Sonnenlichts auf 50 % reduziert war. Die Applikation des NPK-Volldüngers sowie eine Kombination von Düngung und Bewässerung verbesserten die Wuchsleistung von Abaca ebenfalls. Die statistische Auswertung zeigte, dass Beschattung, NPK-Düngung und eine Kombination von Düngung und Bewässerung einen signifikant positiven Effekt ausübte auf Trockenmassebildung, Wachstumsrate, Blattflächenanteil und Netto-Assimilationsrate zwischen Keimlings- und Fahnenblattstadium. Darüber hinaus ergab sich für das Keimlingsstadium und das frühe vegetative Stadium ein signifikanter Einfluss einer hohen Beleuchtungsintensität (und/oder Temperatur) auf die Verteilung der Biomasse und der NPK-Nährstoffe zwischen den Pflanzenorganen und auch die differentielle Blattseneszenz im Fahnenblattstadium, wo Beschattung eine wichtige Rolle spielt, zeigte eine signifikante Beeinflussbarkeit. Die absorbierte NPK-Menge in den verschiedenen Pflanzenorganen variierte jedoch auch in Abhängigkeit vom Wachstum in den einzelnen Entwicklungsphasen und konnte hier jeweils durch Bewässerung und Düngung und die damit verbundene verbesserte Biomasseverteilung gesteigert werden. In Bezug auf agronomische Parameter zeigten Abaca-Pflanzen, die einer 50 %igen Beschattung ausgesetzt waren, signifikant höhere Fasererträge als Pflanzen, die höheren Belichtungsintensitäten ausgesetzt waren, da bei starker Beschattung die Scheinstämme länger, größer und schwerer waren. Eine Kombination von Bewässerung und Düngung konnte den Faserertrag auf 141 % der Kontrolle steigern, jedoch war diese Steigerung geringer als der Effekt einer Beschattung, der den Faserertrag signifikant auf bis zu 265 % der Kontrolle steigerte. Dagegen zeigte die statistische Analyse, dass Beschattung, Bewässerung und Düngung keinen signifikanten Einfluss auf die Feinheit und die Reißfestigkeit der Fasern hatte. Die beobachtete erhöhte Produktivität von Abaca als Reaktion auf Beschattung ist auf eine Vermeidung von Photoinhibition und photooxidativen Schäden zurückzuführen, welche vor allem im Keimlingsstadium und frühen vegetativen Stadium die Pflanzen bei vollem Sonnenlicht negativ beeinflussten. Die nachteiligen Auswirkungen der Photoinhibition auf die photosynthetische Kapazität von Abaca in vollem Sonnenlicht führten zu einer signifikanten Abnahme der Biomasseproduktion und -verteilung

A CASE REPORT ON AYURVEDIC MANAGEMENT OF VICHARCHIKA (ECZEMA)

Kushtarog is classified in 2 types i.e., Mahakushta and Kshudrakushta. Vicharchika is described under Kshudrakushta. Vicharchika is the type of Kshudrakushta often encountered by Ayurvedic dermatologists characterized with symptoms, namely, Kandu, Srava, Pidaka and Shyava varna. Vicharchika is often correlated to eczema based on the clinical presentations. The modern science has greatly advanced, particularly in dermatology but there is no specific medication for sure cure of eczema but symptomatic treatments like steroids are used, but they produce serious side effects like nephrotoxicity, osteoporosis, skin cancer etc. Whereas Ayurveda treats from the root of eczema by cleansing vitiated Dosha and balancing the Dosha and Dhatus without any side effects. A 27 years old male patient approached the OPD with the chief complaints of blackish discoloration, itching, flaking, cracking and bleeding over the anterior side of b/l legs. All the complaints were from 8 months. The patient was given completely Ayurvedic treatment with Panchnimbadi vati, Haridra khand, Gandhak rasayan vati and Sukshma triphala vati, Panchnimbadi churna lepa and Jalaukavcharan and the results were remarkably seen and there was significant improvement in the symptoms. Hence this study was taken to prove that Ayurvedic management has remarkable results in Vicharchika (eczema). Observation and results were drawn on the basis of assessment criteria. Discussion was done on the basis of entire observations during research. Conclusion was drawn on the basis of result

Intuitive Understanding of sigma Delocalization in Loose and sigma Localization in Tight Helical Conformations of a Saturated Chain Oligosilanes

Conformational effects on the amp; 963; electron delocalization in oligosilanes are addressed by Hartree Fock and time dependent density functional theory calculations B3LYP, 6 311G at MP2 optimized geometries of permethylated uniformly helical linear oligosilanes all amp; 969; SinR2n 2 up to n 16 and for backbone dihedral angles amp; 969; 55 180 . The extent of amp; 963; delocalization is judged by the partition ratio of the highest occupied molecular orbital and is reflected in the dependence of its shape and energy and of UV absorption spectra on n. The results agree with known spectra of all transoid loose helix conformers all [ 165] SinMe2n 2 and reveal a transition at amp; 969; amp; 8776;90 from the amp; 963; delocalized limit at amp; 969; 180 toward and close to the physically non realizable amp; 963; localized tight helix limit amp; 969; 0 with entirely different properties. The distinction is also obtained in the Hückel Ladder H and C models of amp; 963; delocalization. An easy intuitive way to understand the origin of the two contrasting limits is to first view the linear chain as two subchains with alternating primary and vicinal interactions amp; 963; hyperconjugation , one consisting of the odd and the other of the even amp; 963; SiSi bonds, and then allow the two subchains to interact by geminal interactions amp; 963; conjugatio

Strong Field Control of the Interatomic Coulombic Decay Process in Quantum Dots

In recent years the laser induced interatomic Coulombic decay ICD process in paired quantum dots has been predicted [J. Chem. Phys. 138 2013 214104]. In this work we target the enhancement of ICD by scanning over a range of strong field laser intensities. The GaAs quantum dots are modeled by a one dimensional double well potential in which simulations are done with the space resolved multi configuration time dependent Hartree method including antisymmetrization to account for the fermions. As a novelty a complementary state resolved ansatz is developed to consolidate the interpretation of transient state populations, widths obtained for the ICD and the competing direct ionization channel, and Fano peak profiles in the photoelectron spectra. The major results are that multi photon processes are unimportant even for the strongest fields. Further, below pi to pi pulses display the highest ICD efficiency while the direct ionization becomes less dominan

DSBOX: herramienta docente para el diseño y simulación de entornos de red virtualizados

En este trabajo se describe DSBOX, una herramienta gráfica para el diseño y simulación empleando virtualización de pequeñas redes de computadores. Se describe el contexto que ha dado origen a esta herramienta y se detalla su arquitectura y las optimizaciones que se han realizado con el fin de dotar a los alumnos de una herramienta operativa que les facilite la realización de prácticas relacionadas con la seguridad informática y la administración de sistemas. Se presenta también un repositorio de actividades prácticas que hacen uso de la herramienta desarrollada.This paper describes DSBOX, a graphical tool for the design and simulation of small computer networks, employing virtualization software. We describe the context where this tool was created and its architecture and the optimizations that have been made in order to provide our students with a tool giving support to teaching activities in computer security and systems management. Finally, a repository with practical exer-cises using this tool is also described

A goodness-of-fit test for the functional linear model with scalar response

In this work, a goodness-of-fit test for the null hypothesis of a functional linear model with scalar response is proposed. The test is based on a generalization to the functional framework of a previous one, designed for the goodness-of-fit of regression models with multivariate covariates using random projections. The test statistic is easy to compute using geometrical and matrix arguments, and simple to calibrate in its distribution by a wild bootstrap on the residuals. The finite sample properties of the test are illustrated by a simulation study for several types of basis and under different alternatives. Finally, the test is applied to two datasets for checking the assumption of the functional linear model and a graphical tool is introduced. Supplementary materials are available online.Comment: Paper: 17 pages, 2 figures, 3 tables. Supplementary material: 8 pages, 6 figures, 10 table