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With the introduction of distributed generators (DG), the traditional distribution system characterized by radical network becomes a multi-source one. Therefore the accuracy of the equivalent model of distributed generators directly affects the precision of fault location. To solve this problem, this paper proposed a fault location method based on complex correlation Thevenin equivalent and strong tracking filter (STF) in distribution network with DG. Strong tracking filter (STF) can be used for real-time extraction of fundamental wave phase and amplitude of single phase voltage and current, and fast track the power parameters mutation. The method of complex correlation Thevenin equivalent takes into account the randomness of measurement data, DG impedance and load to overcome measurement error caused by the uncertainty of the data, so that the construction of the DG impedance model is more accurate. Simulation results show that the method of fault location proposed in this paper has advantages of high accuracy and strong robustness.

Chaos and self-similarity are the state-of-the-art problems in various areas of modern science and technology, thus network systems are not exception from this rule. Increasing number of various network protocols, applications and services leads to the fact that network traffic becomes more complex and unpredictable. It has been shown that phenomenon of self-similarity is caused by the properties of network traffic whose origin is the behavior of ТСР protocol. And all this properties became more significant with appearing of the high-speed data transmission technologies. Finally this behavior leads to congestion in network and packet losses as the result of it. But even modern congestion control mechanisms handle such kind of situations quite unfair. For example, as shown by W. Feng et al., TCP Reno loss rate exceeds 5% in a heavily congested network. So it’s easy to calculate that over a Gigabit Ethernet link such loss rate translates into a loss of over 50 Mb/s. Obviously this level of loss rate is unacceptable. However models that describe behavior of information systems sufficiently and give a possibility for scientists to apply all set of classical methods of chaos theory and analyze particular nonlinear dynamical system have not been offered so far. Phase portraits of the studied system were built and Lyapunov exponents for different values of the basic system parameters were calculated. In the present paper a new approach in analysis of the packet switching networks behavior with ТСР protocol is proposed. These networks are analyzed as nonlinear dynamical systems that show chaotic properties at a certain value of parameters.

Hydrodeoxygenation (HDO) is an important pathway for lignin-oil upgradation to produce high quality liquid fuels, in which the high-active catalyst is the key point to achieve a high HDO efficiency. In this study, Ru/TiO2, Ru/CeO2 and Ru/TiO2-CeO2 catalysts were synthesized by a novel photochemical method with a high Ru dispersion and used for the HDO of lignin-derived phenolic compounds. Among these three catalysts, Ru/ TiO2-CeO2 showed a better performance than Ru/TiO2 and Ru/CeO2. And guaiacol was transformed into cyclohexane with conversion and product selectivity close to 100 % at 230 degrees C under 1 MPa hydrogen atmosphere. Ru/TiO2-CeO2 took the advantages of Ru/TiO2 and Ru/CeO2, namely high Ru metal dispersion, plenty of medium strength acid sites and abundance of oxygen vacancy, which promoted the guaiacol adsorption and the HDO catalytic activity. Moreover, Ru/TiO2-CeO2 catalyst showed an effective upgrading of other lignin-derived phenolic compounds. And the lignin-oil also enabled to be upgraded efficiently, producing a high content of hydrocarbons and alkylphenols.

A method of dislocation pipe diffusion parameters determination during the type B diffusion kinetics is suggested. Proposed method involves diffusion dislocation pipe kinetics for two different annealing times at the same temperature during the type B kinetics and dislocation pipe kinetics for one annealing time at other (lower) temperature during the type C kinetics. Transition time for type B kinetics to type A kinetics (volume diffusion) and kinetics law t1/6 for cone top rate are used in this method. Literature experimental data are used for separate determination of the volume diffusion activation energy and the dislocation pipe diffusion activation energy. ; Запропоновано метод визначення параметрів дифузійних процесів уздовж дислокацій, використовуючи кінетику типу В. У методі використовується дифузійна кінетика типу В вздовж дислокацій для двох різних часів відпалу при одній і тій самій температурі та дифузійна кінетика типу С вздовж дислокацій для одного часу відпалу за іншої (нижчої) температури; застосовується перехідний час від В-режиму до А-режиму (об’ємна дифузія) і кінетичний закон t1/6 для швидкості руху вершини конуса. Літературні експериментальні дані використовуються для визначення енергії активації дифузії окремо в об’ємі та вздовж дислокацій.

Fast pyrolysis is a promising method to convert cellulose and hemicellulose into anhydrosugars, but the current method is energy intensive and provides poor yield and selectivity for anhydrosugars. The possibility of using mineral acid pretreatment to achieve oriented pyrolysis of cellulose and xylan at low temperature was explored in this study. The pyrolysis behaviors and mechanism of cellulose and xylan were investigated by pyrolysis-gas chromatography/mass spectrometry and in-situ diffuse reflectance infrared Fourier transform spectroscopy combined with two-dimensional perturbation correlation infrared spectroscopy. The results showed that H2SO4impregnation and HCl-demineralization achieved the oriented pyrolysis of cellulose and xylan into anhydrosugars at 300 degrees C. The highest yields of levoglucosan and levoglucosenone (33.3 and 9.7%) were obtained from pyrolysis of 0.1%H2SO4-impregnated cellulose at 300 degrees C, while those of xylosan and 1,5-anhydro-4-deoxypent-1-en-3-ulose (19.4 and 8.4%) were produced from pyrolysis of HCl-demineralized xylan at 300 degrees C. It is inferred that H2SO4 could promote the condensation of hydroxyls at C6 and C1 positions and the cleavage of glycosidic bonds to form levoglucosan. And AAEMs could inhibit the intra-molecular dehydration of C3 hydroxyl and C2 hydrogen atom of levoglucosan to form levoglucosenone. The demineralization of xylan could promote the cleavage of glycosidic bonds and dehydration reactions to form xylosan and 1,5-anhydro-4-deoxypent-1-en3-ulose. These findings provide a simple method to achieve oriented pyrolysis of cellulose and xylan at low temperature.

Пандемія COVID-19 негативно впливає на досягнення більшості Цілей сталого розвитку, що призводить до суттєвої кризи, особливо відчутної в країнах з менш розвиненою економікою. Таким чином, перед урядами країн світу постають серйозні завдання. Негативний річний приріст ВВП на душу населення в Азербайджані за 2020 рік склав -4,95% (нижче за середньосвітовий показник на 0,56%). Це зумовлює необхідність не тільки відновлення короткострокового економічного зростання, а й досягнення довгострокової конкурентоспроможності, сталого розвитку та інклюзивної економіки. У статті зазначено, що Азербайджан займає 58 місце зі 141 у рейтингу глобальної конкурентоспроможності (при цьому 63 місце за інноваційним потенціалом та 73 місце за впровадження ІКТ); 55 місце зі 165 за Індексом сталого розвитку; 80 місце зі 131 у Глобальному інноваційному індексі, що свідчить про важливу роль менеджменту інновацій в Азербайджані. Основною метою статті є дослідження взаємозв'язків між інноваційним розвитком, конкурентоспроможністю та сталим розвитком країни. Для емпіричного підтвердження висунутих гіпотез була сформована вибірка з 9 країн світу (Азербайджан, Грузія, Вірменія, Німеччина, Франція, Фінляндія, Естонія, Польща, Чехія). Автором проведено аналіз низки показників, ґрунтуючись на даних статистичного відділу Департаменту з економічних та соціальних питань Організації Об'єднаних Націй, Світового банку, Світового економічного форуму та Світового організації інтелектуальної власності за період із 2010 по 2020 рр. У роботі проведено статистичний аналіз індикаторів сталого розвитку, конкурентоспроможності та інноваційного розвитку досліджуваних країн. За допомогою кореляційно-регресійного аналізу та тесту Грейнджера (з використанням програмного пакету STATA) встановлено взаємні напрямки впливу показників інноваційного розвитку, конкурентоспроможності країни та її сталого розвитку в Азербайджані та інших країнах вибірки. Побудовано регресійну модель з випадковими ефектами, формалізовано та оцінено вплив параметрів інноваційного розвитку на ...

Water transport is of paramount importance to the cold start of proton exchange membrane fuel cells (PEMFCs). Analysis of water transport in cathode catalyst layer (CCL) during cold start reveals the distinct characteristics from the normal temperature operation. This work studies the effect of CCL mesoscopic poremorphology on PEMFC cold start. The CCL mesoscale morphology is characterized by two tortuosity factors of the ionomer network and pore structure, respectively. The simulation results demonstrate that the mesoscale morphology of CCL has a significant influence on the performance of PEMFC cold start. It was found that cold-starting of a cell with a CCL of less tortuous mesoscale morphology can succeed, whereas starting up a cell with a CCL of more tortuous mesoscale morphology may fail. The CCL of less tortuous pore structure reduces the water back diffusion resistance from the CCL to proton exchange membrane (PEM), thus enhancing the water storage in PEM, while reducing the tortuosity in ionomer network of CCL is found to enhance the water transport in and the water removal from CCL. For the sake of better cold start performance, novel preparation methods, which can create catalyst layers of larger size primary pores and less tortuous pore structure and ionomer network, are desirable.

A novel parallel random number generator(RNG) based on two dimensions feedback shift register(2-DFSR), genetic algorithm(GA) and cellular automaton(CA) algorithms is proposed for wireless medical security applications. The measurement results demonstrated that the RNG can successfully pass the NIST800-22 statistical test suite. The highest bit rate is16 Mbps. The typical power consumption is61.81μW. Its energy efficiency is3.86 pJ/bit.?2011 IEEE.

Biodiesel has been identified as a promising substitute for diesel derived from petroleum. Both edible and non-edible oils are used in the production of biodiesel. Used cooking oil can be a promising feedstock for low-cost biodiesel production. Moreover, the production of biodiesel from used cooking oil will not only avoid the competition of the same oil resources for food and fuel but will also overcome the waste cooking oil disposal problems. In this study, γ-Al2O3 was modified with 5-20wt% of KOH to form γ-Al2O3-KOH bifunctional heterogeneous support. The supports were then impregnated with 5wt% Mn and tested for biodiesel production from used palm cooking oil. The catalyst which shows the highest biodiesel yield was then further modified with Mn, Sn and Zn to form bimetallic catalysts and the activity of these catalysts were tested for biodiesel production. Among different catalysts tested, Mo-Mn/γ-Al2O3-20 wt% KOH catalyst shows the highest biodiesel yield of 85.6% in 4 h reaction at 110 °C, methanol to oil molar ratio of 30:1, catalyst loading of 7 wt% and agitation speed of 600 rpm. Moreover, the catalyst shows substantial chemical stability and could be used for at least 6 times without any major loss in its catalytic activity. The physicochemical properties of the synthesized biodiesel were further studied and compared with ASTM and the European biodiesel specifications. The results show that the properties of the biodiesel produced comply with the international standard specifications.

The Hamiltonian of the zinc-blende quantum rods in the framework of eight-band effective-mass approximation in the presence of external homogeneous magnetic field is given. The electronic structure, optical properties and electron g factors of GaAs quantum rods are investigated. We found that the electron g factors are very sensitively dependent on the dimensions of the quantum rods. As some of the three dimensions increase, the electron g factors decrease. The more the dimensions increase, the more the electron g factors decrease. The dimensions perpendicular to the direction of the magnetic field affect the electron g factors more than the other dimension. (c) 2006 Elsevier B.V. All rights reserved.