20 research outputs found
REMOVED: Gas Permeation through PDMS Membranes Covered by 1 or 3nm Thick Carbon Nanomembranes (CNMs)
This article has been removed: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been removed at the request of the Executive Publisher.This article has been removed because it was published without the permission of the author(s)
Polyimide hollow fiber membranes for CO2 separation from wet gas mixtures
Matrimid®5218 hollow fiber membranes were prepared using the dry-wet spinning process. The transport properties were measured with pure gases (H2, CO2, N2, CH4 and O2) and with a mixture (30% CO2 and 70% N2) in dry and wet conditions at 25 ºC, 50 ºC, 60 ºC and 75 ºC and up to 600 kPa. Interesting values of single gas selectivity up to 60 ºC (between 31 and 28 for CO2/N2 and between 33 and 30 for CO2/CH4) in dry condition were obtained. The separation factor measured for the mixture was 20% lower compared to the single gas selectivity, in the whole temperature range analyzed. In saturation conditions the data showed that water influences the performance of the membranes, inducing a reduction of the permeance of all gases. Moreover, the presence of water caused a decrease of single gas selectivity and separation factor, although not so significant, highlighting the very high water resistance of hollow fiber membrane modules
REMOVED: Stability of Pebax® or Polyactive® Blended with Low Molecular Weight PEG as Materials for CO2 Selective Membranes
Charge Air Separation for the Reduction of Marine Diesel Engine Emissions by Means of Poly(Vinyl Trimethylsilane) Membranes
REMOVED: Gas Permeation through PDMS Membranes Covered by 1 or 3 nm Thick Carbon Nanomembranes (CNMs)
The method of selecting the operating mode of multi-antenna military radiocommunication systems
У статті запропоновано методику вибору режимів роботи багатоантенних систем військового радіозв’язку в залежності від сигнально-завадової обстановки, яка заснована на адаптивному управлінні режимами роботи та параметрами режимів багатоантенних систем. Розроблена методика дозволяє здійснювати вибір режимів роботи багатоантенних систем військового радіозв’язку за схемами МІМО та МІМО-OFDM.В статье предложена методика выбора режимов работы многоантенных систем военной радиосвязи в зависимости от сигнально-помеховой обстановки, которая основана на адаптивном управлении режимами работы и параметрами режимов многоантенных систем. Разработанная методика позволяет осуществлять выбор режимов работы многоантенных систем военного радиосвязи по схемам МІМО и МІМО-OFDM.The article proposes a technique for selecting the modes of operation of multi-antenna systems of military radio communication, depending on the signal-interference situation, which is based on adaptive control of operating modes and parameters of multi-antenna systems. The developed technique allows to select the modes of operation of multi-antenna systems of military radio communication according to the schemes MIMO and MIMO-OFDM
Functionalized Carbon Nanotube Mixed Matrix Membranes of Polymers of Intrinsic Microporosity (PIMs) for Gas Separation
Method of selection rational values of parameters of multi-antenna systems of military radio communications with pseudo-random reconstruction of operating frequency
У статті запропоновано удосконалену методику вибору раціональних значень параметрів багатоантенних систем військового радіозв’язку з псевдовипадковою перестройкою робочої частоти в залежності від сигнально-завадової обстановки. Зазначена методика дозволяє здійснювати прогнозування сигнальнозавадової обстановки, обирати найбільш придатні робочі частоти, а також дозволяє не тільки змінювати швидкість перестройки робочої частоти але й змінювати вид та тривалість розширювальної послідовності, а також початкове заповнення формуючого поліному.В статье предложено усовершенствованную методику выбора рациональных значений параметров многоантенных систем военной радиосвязи с псевдослучайной перестройкой рабочей частоты в зависимости от сигнальнопомеховой обстановки. Указанная методика позволяет осуществлять прогнозирование сигнально-помеховой обстановки, выбирать наиболее подходящие рабочие частоты, а также позволяет не только изменять скорость перестройки рабочей частоты, но и изменять вид и продолжительность расширительной последовательности, а также начальное заполнение формирующего полинома.In the article offered an improved method of selecting rational values of the parameters of multi-antenna systems of military radio communication with pseudo-random reconstruction of the operating frequency, depending on the signalinterference situation. This technology makes it possible to predict the signal-noise environment, choose the most suitable operating frequencies, and also is not only change speed of the reconstruction of the operating frequency, but also to change form and duration of the expansion sequence, and also initial filling of the forming polynomial
A Bayesian detection and attribution analysis of extreme temperature changes during 1951-2010
Synthesis, Characterization, and Properties of Poly(1-trimethylsilyl-1-propyne)-<i>block</i>-poly(4-methyl-2-pentyne) Block Copolymers
Poly(1-trimethylsilyl-1-propyne)-<i>block</i>-poly(4-methyl-2-pentyne)
(PTMSP-<i>b</i>-PMP) block copolymers of different composition
were synthesized through sequential living polymerization by catalytic
systems based on niobium pentachloride with organometallic cocatalysts
in cyclohexane. Mechanical, thermal, and gas transport properties
of synthesized block copolymers are investigated. The morphology of
PTMSP-<i>b</i>-PMP can be described as a two-phase supramolecular
structure which includes regions with an increased level of ordering,
distributed in an amorphous phase. The observed structure of block
copolymers is explained by the presence of densely packed poly(4-methyl-2-pentyne)
(PMP) blocks and less ordered poly(1-trimethylsilyl-1-propyne) (PTMSP)
blocks. The correlation of morphology of block copolymers with gas
transport parameters as well as with resistance toward organic solvents
is discussed. As result of this study, novel polymeric materials based
on PTMSP and PMP combining resistance toward aromatic and aliphatic
hydrocarbons with high gas transport parameters are synthesized