Photoassisted sequential resonant tunneling through superlattices

We have analyzed theoretically the photoassisted tunneling current through a superlattice in the presence of an AC potential. For that purpose we have developed a new model to calculate the sequential resonant currrent trhough a superlattice based in the TRansfer Hamiltonian Method. The tunneling current presents new features due to new effective tunneling chanels coming from the photoside bands induced by the AC field. Our theoretical results are in good agreement with the available experimental evidence.Comment: Revtex 3.0 4 pages, 4 figures uuencoded compressed tar-fil

Quantum-mechanical wavepacket transport in quantum cascade laser structures

We present a viewpoint of the transport process in quantum cascade laser structures in which spatial transport of charge through the structure is a property of coherent quantum-mechanical wavefunctions. In contrast, scattering processes redistribute particles in energy and momentum but do not directly cause spatial motion of charge.Comment: 6 pages, 5 figures included in tex, to appear in Physical Review

Covariant spectator theory of np scattering: Phase shifts obtained from precision fits to data below 350 MeV

Using the covariant spectator theory (CST), we present two one boson exchange kernels that have been successfully adjusted to fit the 2007 world np data (containing 3788 data) below 350 MeV. One model (which we designate WJC-1) has 27 parameters and fits with a chi2/N = 1.06. The other model (designated WJC-2) has only 15 parameters and fits with a chi2/N = 1.12. Both of these models also reproduce the experimental triton binding energy without introducing additional irreducible three-nucleon forces. One result of this work is a new phase shift analysis, updated for all data until 2006, which is useful even if one does not work within the CST. In carrying out these fits we have reviewed the entire data base, adding new data not previously used in other high precision fits and restoring some data omitted in previous fits. A full discussion and evaluation of the 2007 data base is presented.Comment: 43 pages, 27 figures, and 13 table

Liquid Argon HEC Wheel Assembly Database

This document describes the details of the contents of the LAr Hadronic EndCap Wheel Assembly Database. This database contains the important data from the wheel assembly: mechanical alignment, electrical properties, cabling, and a summary of the readout gap failures. This document describes the final database that is intended mainly for archival purposes. This database should be viewed in conjunction with the HEC module production database that describes the modules that form the wheel and the Feedthrough database that describes the signal feedthroughs. This wheel database lists for instance the location of the modules, the amplifiers to which they are connected, and the details of the alignment measurements. It also details all non-conformances. It is important that for all non-conformances, whether they occurred during wheel assembly or in the B180 cold tests, that a single table be produced of all the non-conformances listing the non-conformance in a format suitable for making offline corrections to the data. This non-conformance table will be derived from a set of queries of this database

Nanohelices as superlattices: Bloch oscillations and electric dipole transitions

Subjecting a nanohelix to a transverse electric field gives rise to superlattice behavior with tunable electronic properties. We theoretically investigate such a system and find Bloch oscillations and negative differential conductance when a longitudinal electric field (along the nanohelix axis) is also applied. Furthermore, we study dipole transitions across the transverse-electric-field-induced energy gap, which can be tuned to the eulogized terahertz frequency range by experimentally attainable external fields. We also reveal a photogalvanic effect by shining circularly polarized light onto our helical quantum wire.We acknowledge financial support from the CNRS and from the ANR under Grant No. ANR-14-CE26-0005 Q-MetaMat, as well as the EU H2020 RISE project CoExAN (Grant No. H2020-644076), EU FP7 ITN NOTEDEV (Grant No. FP7-607521), and the FP7 IRSES projects CANTOR (Grant No. FP7-612285), QOCaN (Grant No. FP7-316432), and InterNoM (Grant No. FP7-612624)

Cyclotron resonance in a two-dimensional electron gas with long-range randomness

We show that the the cyclotron resonance in a two-dimensional electron gas has non-trivial properties if the correlation length of the disorder is larger than the de Broglie wavelength: (a) the lineshape assumes three different forms in strong, intermediate, and weak magnetic fields (b) at the transition from the intermediate to the weak fields the linewidth suddenly collapses due to an explosive growth in the fraction of electrons with a diffusive-type dynamics.Comment: A few typos correcte

Intersubband gain in a Bloch oscillator and Quantum cascade laser

The link between the inversion gain of quantum cascade structures and the Bloch gain in periodic superlattices is presented. The proposed theoretical model based on the density matrix formalism is able to treat the gain mechanism of the Bloch oscillator and Quantum cascade laser on the same footing by taking into account in-plane momentum relaxation. The model predicts a dispersive contribution in addition to the (usual) population-inversion-dependent intersubband gain in quantum cascade structures and - in the absence of inversion - provides the quantum mechanical description for the dispersive gain in superlattices. It corroborates the predictions of the semi-classical miniband picture, according to which gain is predicted for photon energies lower than the Bloch oscillation frequency, whereas net absorption is expected at higher photon energies, as a description which is valid in the high-temperature limit. A red-shift of the amplified emission with respect to the resonant transition energy results from the dispersive gain contribution in any intersubband transition, for which the population inversion is small.Comment: 10 pages, 6 figure

Вибір оптимального зволожувача при розробці складу та технології отримання капсул з ніфуроксазидом

Aim. To choose the optimal moisturizer and its concentration to obtain the granulate with the necessary technological parameters and high-quality capsules with nifuroxazide.Materials and methods. The objects of the study were the substance of nifuroxazide by “SP QUIMICA” company, Spain, moisturizing agents: 15 % aqueous and alcoholic solutions of polyvinylpyrrolidone (PVP) of K-25 brand, 15 % aqueous solution of PVP of K-29/32 brand, 10 % corn paste, 64 % sugar syrup, 14 % aqueous solution of PVP of K-17 brand, the mass for encapsulation and capsules obtained from them. The following quality indicators were studied: description, average mass, mass homogeneity, uniformity of dosage units, disintegration, flowability, bulk density, fractional composition, dissolution, admixture A and related impurities, the quantitative content of nifuroxazide. The following methods were used: liquid chromatography method (SPhU, 2.2.29), absorption spectrophotometry method in the ultraviolet region (SPhU, 2.2.25).Results and discussion. The effect of the type and concentration of binders and other excipients on the physicochemical, pharmacotechnological properties of the masses for encapsulation, the quality indicators of the capsules and the “Dissolution” test in the borate buffer solution with pH 10.0 have been studied.The dependence of the quality of the finished product on the nature of the moisturizing agents introduced has been determined. It has been shown that the optimal moisturizer is 14 % aqueous solution of PVP of K-17 brand. The  ptimal amounts of excipients for obtaining a stable drug have been determined. The capsules developed are equivalent to the reference drug Enterofuril capsules, 200 mg, manufactured by Bosnalijek, Bosnia and Herzegovina by their functional characteristics.Conclusions. Based on the pharmacotechnological studies conducted and the analysis of the quality of the capsules obtained the compositions of excipients and moisturizer, as well as the method of obtaining the capsule mass, were selected. The study conducted is the necessary part of the pharmaceutical development (PD) of the drug when substantiating its composition and technology. A promising direction for further research is conducting further stages of PD, as well as the completion of section 3.2.P.2.3 “Development of the production process” of the Common Technical Documentation (CTD) format registration dossier.Цель работы. Выбор оптимального увлажнителя и его концентрации для получения гранулята с необходимыми технологическими параметрами и качественных капсул с нифуроксазидом.Материалы и методы. Объектами исследования были субстанция нифуроксазида фирмы «SP QUIMICA», Испания, увлажняющие агенты: 15 % водный и спиртовой растворы поливинилпирролидона (ПВП) К-25, 15 % водный раствор ПВП К-29/32, 10 % кукурузный клейстер, 64 % сахарный сироп, 14 % водный раствор ПВП К-17, массы для капсулирования и капсулы, полученные на их основе. Изучены показатели качества: описание, средняя масса, однородность массы, однородность дозированных единиц, распадаемость, текучесть, насыпная плотность, фракционныйсостав, растворение, примесь А и сопутствующие примеси, количественное содержание нифуроксазида. Использованы методы: метод жидкостной хроматографии (ГФУ, 2.2.29), метод абсорбционной спектрофотометрии в ультрафиолетовой области (ГФУ, 2.2.25).Результаты и их обсуждение. Изучено влияние вида и концентрации связующих и других вспомогательных веществ на физико-химические, фармакотехнологические свойства масс для капсулирования, показатели качества капсул и тест «Растворение» в среде боратного буферного раствора рН 10,0. Определена зависимость качества готового лекарственного препарата от природы введенных увлажняющих агентов. Показано, что оптимальным увлажнителем является 14 % водный раствор ПВП марки К-17. Определены оптимальные количества вспомогательных веществ для получения стабильного лекарственного препарата. Разработанные капсулы являются эквивалентными референтному препарату «Энтерофурил», капсулы по 200 мг производства фирмы «Bosnalijek», Босния и Герцеговина по функциональным характеристикам.Выводы. На основании проведенных фармакотехнологических исследований и анализа качества полученных капсул выбран состав вспомогательных веществ, состав увлажнителя и способ получения капсульной массы. Проведенные исследования являются необходимой частью фармацевтической разработки (ФР) препарата при обосновании его состава и технологии. Перспективным направлением дальнейших исследований является проведение дальнейших этапов ФР, а также оформление раздела 3.2.Р.2.3 «Разработка производственного процесса» регистрационного досье формата Common Technical Documentation (CTD).Мета роботи. Вибір оптимального зволожувача і його концентрації для отримання грануляту з необхідними технологічними параметрами і якісних капсул з ніфуроксазидом.Матеріали та методи. Об’єктами дослідження були субстанція ніфуроксазиду фірми «SP QUIMICA», Іспанія, зволожуючі агенти: 15 % водний і спиртовий розчини полівінілпіролідону (ПВП) К-25, 15 % водний розчин ПВП К-29/32, 10 % кукурудзяний клейстер, 64 % цукровий сироп, 14 % водний розчин ПВП К-17, маси для капсулювання і капсули, отримані на їх основі. Вивчені показники якості: опис, середня маса, однорідність маси, однорідність дозованих одиниць, розпадання, текучість, насипна густина, фракційний склад, розчинення, домішка А і супутні домішки, кількісний вміст ніфуроксазиду. Використано методи: метод рідинної хроматографії (ДФУ, 2.2.29), метод абсорбційної спектрофотометрії в ультрафіолетовій області (ДФУ 2.2.25).Результати та їх обговорення. Вивчено вплив виду та концентрації зв’язувальних та інших допоміжних речовин на фізико-хімічні, фармакотехнологічні властивості мас для капсулювання, показники якості капсул і тест «Розчинення» в середовищі боратного буферного розчину рН 10,0. Визначено залежність якості готового лікарського препарату від природи введених зволожуючих агентів. Показано, що оптимальним зволожувачем є 14 % водний розчин ПВП марки К-17. Визначені оптимальні кількості допоміжних речовин для отримання стабільного лікарського препарату. Розроблені капсули є еквівалентними до референтного препарату «Ентерофурил», капсули по 200 мг виробництва фірми «Bosnalijek», Боснія і Герцеговина за функціональними характеристиками.Висновки. На підставі проведених фармакотехнологічних досліджень та аналізу якості отриманих капсул обрано склад допоміжних речовин, склад зволожувача і спосіб отримання капсульної маси. Проведені дослідження є необхідною частиною фармацевтичної розробки (ФР) препарату при обґрунтуванні його складу і технології. Перспективним напрямком подальших досліджень є проведення подальших етапів ФР, а також оформлення розділу 3.2.Р.2.3 «Розробка виробничого процесу» реєстраційного досьє формату Common Technical Documentation (CTD)

Perturbative fragmentation

The Berger model of perturbative fragmentation of quarks to pions is improved by providing an absolute normalization and keeping all terms in a (1-z) expansion, which makes the calculation valid at all values of fractional pion momentum z. We also replace the nonrelativistic wave function of a loosely bound pion by the more realistic procedure of projecting to the light-cone pion wave function, which in turn is taken from well known models. The full calculation does not confirm the (1-z)^2 behavior of the fragmentation function (FF) predicted in for $z>0.5$, and only works at very large z>0.95, where it is in reasonable agreement with phenomenological FFs. Otherwise, we observe quite a different z-dependence which grossly underestimates data at smaller z. The disagreement is reduced after the addition of pions from decays of light vector mesons, but still remains considerable. The process dependent higher twist terms are also calculated exactly and found to be important at large z and/or pT.Comment: 10 pages, 8 figure