1,273 research outputs found
Evaluating a ZigBee Network with SMC for Hard and Concurrent Parameter Variations
One of the main issues concerning a wireless networked control system is the variable delay associated with the communicating network used to join its dispersed components. This paper presents a variable structured Sliding Mode Controller (SMC) designed for a ZigBee wireless networked control system (WNCS) in addition to the design of a standard PID controller. WNCS can improve the reliability and the effectiveness of the control system by eliminating time and costs of installation and maintenance. Presence of time delays between sensors, actuators and controllers of the controlled system can degrade the performance and destabilize the whole system. To reduce the effect of the network delay, simulation tools for WNCS are developed to help designers in studying the influence of network on performance of the control system. The TrueTime toolbox is used to analyze the effects of network delays and to evaluate the effects of ZigBee parameters on control systems such as packet loss, ACK. Timeout limit, and traffic load. It is clear from the results that SMC is superior to PID control. Keywords: NCS, SMC, PID, ZigBee, TrueTim
Electrical behavior and Optical Properties of Copper oxide thin Films
In this work the structural, electrical and optical Properties of CuO semiconductor films had been studied, which prepared at three thickness (100, 200 and 500 nm) by spray pyrolysis method at 573K substrate temperatures on glass substrates from 0.2M CuCl2•2H2O dissolved in alcohol. Structural Properties shows that the films have only a polycrystalline CuO phase with preferential orientation in the (111) direction, the dc conductivity shows that all films have two activation energies, Ea1 (0.45-0.66 eV) and Ea2 (0.055-.0185 eV), CuO films have CBH (Correlated Barrier Hopping) mechanism for ac-conductivity. The energy gap between (1.5-1.85 eV)
(2E)-1-(2,5-Dimethylthiophen-3-yl)-3-(3-nitrophenyl)prop-2-en-1-one
In the title compound, C15H13NO3S, the benzene ring and the five-membered heterocyclic ring are oriented at a dihedral angle of 12.00 (6)°. In the crystal, C—H⋯O interactions generate two types of cyclic motifs, R
2
2(14) and R
2
2(26), connecting the molecules into tapes extending along [101]. In addition, there are π–π stacking interactions between the benzene and thiophene rings with centroid-centroid distances of 3.7263 (14) and 3.7487 (14) Å
N-[(E)-Anthracen-9-ylmethylidene]-3,4-dimethyl-1,2-oxazol-5-amine
In the title compound, C20H16N2O, an intramolecular C—H⋯N forms an S(6) ring motif. In the crystal, the molecules are stacked with their anthracene ring planes in sheets along [100]
Quantum criticality in Kondo quantum dot coupled to helical edge states of interacting 2D topological insulators
We investigate theoretically the quantum phase transition (QPT) between the
one-channel Kondo (1CK) and two-channel Kondo (2CK) fixed points in a quantum
dot coupled to helical edge states of interacting 2D topological insulators
(2DTI) with Luttinger parameter . The model has been studied in Ref. 21,
and was mapped onto an anisotropic two-channel Kondo model via bosonization.
For K<1, the strong coupling 2CK fixed point was argued to be stable for
infinitesimally weak tunnelings between dot and the 2DTI based on a simple
scaling dimensional analysis[21]. We re-examine this model beyond the bare
scaling dimension analysis via a 1-loop renormalization group (RG) approach
combined with bosonization and re-fermionization techniques near weak-coupling
and strong-coupling (2CK) fixed points. We find for K -->1 that the 2CK fixed
point can be unstable towards the 1CK fixed point and the system may undergo a
quantum phase transition between 1CK and 2CK fixed points. The QPT in our model
comes as a result of the combined Kondo and the helical Luttinger physics in
2DTI, and it serves as the first example of the 1CK-2CK QPT that is accessible
by the controlled RG approach. We extract quantum critical and crossover
behaviors from various thermodynamical quantities near the transition. Our
results are robust against particle-hole asymmetry for 1/2<K<1.Comment: 17 pages, 9 figures, more details added, typos corrected, revised
Sec. IV, V, Appendix A and
Degradabilidade in situ da matéria seca de resíduos e subprodutos agroindustriais em Porto Velho, Rondônia.
Este trabalho teve o objetivo de avaliar os parâmetros de degradação in situ da matéria seca (MS) da farinha de pupunha (FP), obtida após a secagem do resíduo da extração da semente da pupunha (Bactris gasipaes Kunth), do resíduo de amêndoas de cupuaçu (RC), resultante da extração da manteiga de cupuaçu (Theobroma grandiflorum) e da torta de castanha (TC), subproduto da extração do óleo da castanha-do-Brasil (Bertholletia excelsa, H.B.K.). Foi realizado um ensaio com três novilhos fistulados no rúmen com peso vivo médio de 499 kg
Avaliação nutricional de subprodutos do processamento agroindustrial de cupuaçu, pupunha e castanha-do-brasil em Porto Velho, Rondônia.
Diversos subprodutos da agroindústria podem ser utilizados na alimentação de ruminantes, contribuindo de forma significativa na redução dos custos com a alimentação do rebanho. A composição química e bromatológica, bem como os parâmetros de degradação ruminal da matéria seca (MS) e da proteína bruta (PB) dos subprodutos das extrações do óleo da castanhado-brasil (Bertholletia excelsa, H.B.K.), da manteiga das amêndoas do cupuaçu (Theobroma grandiflorum) e da semente do fruto da pupunha (Bactris gasipaes, Kunth) foram determinados nesse estudo. Para tanto, foram realizadas análises laboratoriais e um ensaio de degradabilidade in situ com três novilhas canuladas no rúmen para incubação de amostras dos subprodutos por 2, 4, 6, 8, 12, 24 e 48 horas. A torta de cupuaçu apresentou 93,52% de MS; 12,59% de PB; 12,33% de extrato etéreo (EE); 4,36% de cinzas (CZ), coeficientes de degradabilidade potencial (DP) da MS de 55,71% e da PB de 93,22; a farinha de pupunha apresentou 94,35% de MS; 5,84% de PB, 21,95% de EE; 1,43% de CZ, DP da MS de 88,84% e da PB de 99,57; e a torta de castanha apresentou 95,32% de MS; 34,22% de PB; 43,59% de EE; 3,37% de CZ, DP da MS de 89,27% e da PB de 97,76%. De acordo com os teores de PB dos subprodutos avaliados, a torta de castanha foi classificada como concentrado proteico e os outros dois como concentrados energéticos. Com exceção da torta de cupuaçu, os subprodutos apresentaram matéria seca e proteína com elevada degradabilidade ruminal.bitstream/item/139149/1/BPD-72-alimentacaoderuminantes.pd
Enhanced reaction kinetics in biological cells
The cell cytoskeleton is a striking example of "active" medium driven
out-of-equilibrium by ATP hydrolysis. Such activity has been shown recently to
have a spectacular impact on the mechanical and rheological properties of the
cellular medium, as well as on its transport properties : a generic tracer
particle freely diffuses as in a standard equilibrium medium, but also
intermittently binds with random interaction times to motor proteins, which
perform active ballistic excursions along cytoskeletal filaments. Here, we
propose for the first time an analytical model of transport limited reactions
in active media, and show quantitatively how active transport can enhance
reactivity for large enough tracers like vesicles. We derive analytically the
average interaction time with motor proteins which optimizes the reaction rate,
and reveal remarkable universal features of the optimal configuration. We
discuss why active transport may be beneficial in various biological examples:
cell cytoskeleton, membranes and lamellipodia, and tubular structures like
axons.Comment: 10 pages, 2 figure
PHYTOCHEMICAL FINGERPRINT AND BIOLOGICAL ACTIVITIES OF THREE MALAYSIAN FICUS DELTOIDEA CULTIVARS.
Background
Ficus deltoidea (Moraceae), is a Malay Traditional Medicine locally known as Mas Cotek. Three varieties (angustifolia, deltoidea and kunslerii) has been indictincty used.
Aims
We here aim to better understand their chemistry and bioactivities to inform future scientific and agronomic research.
Methods
We extracted and analyzed samples from these varieties by HPTLC and HPLC-UV. The in vitro screening looked up to the scavenging activities against both DPPH and NO radicals, inhibitory activity upon tyrosinase and cytotoxicity against human prostate cancer cells PC3, DU145 and LNCaP using the sulforhodamine B proliferation assay and the MTT mitochondrial viability assay.
Results
We achieved to analytically differentiate the three varieties in term of the presence of flavonoids, establishing that vitexin, orientin and isoorientin may act as intraspecific and interorgan phytomarkers Their biological activities point out to the antioxidant value of extracts from the deltoidea and kunslerii varieties whilst the inhibition of tyrosinase is only present in the roots extract of the var. deltoidea which here we show is also endowed with cytotoxic activity against prostate cancer cells.
Conclusion
We suggest that the three Malaysian Ficus deltoidea botanical varieties (angustifolia, deltoidea and kunslerii) can be also considered chemovars. The least bioactive chemovar was angustifolia. The most active extract was from the roots of var. deltoidea that shows antioxidant, antimelanogenic and cytotoxic potential.
Keywords: Chemotaxonomy; Prostate Cancer; Tyrosinase; Antioxidant; Ficus
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