58,260 research outputs found
The mixed Wentzel-Kramers-Brillouin-full-wave approach and its application to lower hybrid wave propagation and absorption
No full textThe mixed Wentzel-Kramers-Brillouin (WKB)-full-wave approach for the calculation of the 2D mode structure in tokamak plasmas is further developed based on our previous work [A. Cardinali and F. Zonca, Phys. Plasmas 10, 4199 (2003) and Z. X. Lu et al., Phys. Plasmas 19, 042104 (2012)]. A new scheme for theoretical analysis and numerical implementation of the mixed WKB-full-wave approach is formulated, based on scale separation and asymptotic analysis. Besides its capability to efficiently investigate the initial value problem for 2D mode structures and linear stability, in this work, the mixed WKB-full-wave approach is extended to the investigation of radio frequency wave propagation and absorption, e. g., lower hybrid waves. As a novel method, its comparison with other approaches, e.g., WKB and beam tracing methods, is discussed. Its application to lower hybrid wave propagation in concentric circular tokamak plasmas using typical FTU discharge parameters is also demonstrated. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4798408]http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000317295200016&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, Fluids & PlasmasSCI(E)EI8ARTICLE3null2
Lu=x^u+kux=x f(x,y) Eliptik denklemi için genelleştirilmiş fonksiyon sınıflarında bazı problemler
No full textThis work consists of six parts. The first part, which is the introduction part, organized to help, the other parts in the points of understanding. In the second part we have been given domain D and a solution related with the equation (1.1) given, on a part of the boundary of D. Under these conditions we examined the solution of the boundary value problem in domain D. We have also examined the properties of existency, uniticty and stability for the solution of the problem in some known spaces. In these examinations we used a priori, Galerkin and Carleman methods. In the third part we add the term K(x, y, %, tj) u (£, t|) dÇ dTj to the equation (1.1) and examined the solution of the new boundary value problem as in the second part. After this we obtained some results similar to the second part. In part four, we examined the mixed problem related with the equation (1.1 ). In part five, we examined the inverse problem of finding the pair of ( u, f ) related with the equation Lu = x f ( x, 'y ). In the last part, which is the sixth part, we examined the solution of Cauchy problem related with the equation of Lu = x f ( x, 'y ). After that we add the condition of u| = u 2 to the Cauchy problem examined the inverse problem of finding ( u, f ) pair. Key Words : Potential theory, elliptic type equation, inverse problem, mixed problem generalized function, Galerkin method.Bu çalışma altı bölümden oluşmaktadır. Birinci bölüm olan giriş bölümü, diğer bölümlerde incelenen problemlerin anlaşılmasına yardımcı olacak şekilde düzenlenmiştir. ikinci bölümde belirli bir D bölgesinin sınırının bir kısmında çözüm verildiğinde bu bölgenin içinde ( 1. 1 ) denklemi ile ilgili problemin çözümünün bulunması incelenmiştir. Problemin çözümünün varlığı, tekliği ve kararlılığı belirli uzaylarda incelenmiştir. Bu incelemelerde kullanılan yöntemler ön değerlendirmeler, Galerkin ve Carieman metodlarıdır. Üçüncü bölümde (1.1) denklemine K(x, y, £, r\) u (£, ti) d| dTj integral ifadesi ekle- nerek meydana gelen denklem için 2. bölümde olduğu gibi problem incelenip benzer sonuçlar elde edilmiştir. Dördüncü bölümde karışık problem incelenmiştir. Beşinci bölümde Lu s xf(x, *y) denkleminde belirli şartlar verildiğinde ( u, f ) çiftinin bulunması ters problemi incelenmiştir. Son bölüm olan, altıncı bölümde verilen Cauchy problemine u| _ = u2 şartı eklenerek ( u, f ) çiftinin bulunması ile ilgili ters problem incelenmiştir.ANAHTAR KELİMELER : Potansiyel teori, eliptik tip diferensiyel denklem, ters problem, karışık problem, genelleştirilmiş fonksiyon, Galerkin metodu
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Spectroscopic analysis of Nd(3+) doped (Lu (x) + Gd(1-x) )(3)Ga(5)O(12) crystal
No full textIn this paper we report a complete optical investigation of Nd(3+) doped (Lu (x) + Gd(1-x) )(3)Ga(5)O(12) crystal including the absorption and emission spectroscopy at room temperature and 10 K, the excitation spectroscopy at 10 K clearly showing the multi-site feature, and the lifetime at temperatures from 10 K to 300 K. The Judd-Ofelt theory has been applied to calculate the spontaneous transition probabilities, the branching ratio, and the radiative lifetime of the (4)F(3/2) multiplet; the calculated results are in good agreement with the experimental ones. Finally, we calculated the emission cross sections of the transitions concerned to evaluate the potential of the material in laser field application
Some problems in the genelazed function classes for the elliptic equation Lu=x^u+kux=x f(x,y)
No full textThis work consists of six parts. The first part, which is the introduction part, organized to help, the other parts in the points of understanding. In the second part we have been given domain D and a solution related with the equation (1.1) given, on a part of the boundary of D. Under these conditions we examined the solution of the boundary value problem in domain D. We have also examined the properties of existency, uniticty and stability for the solution of the problem in some known spaces. In these examinations we used a priori, Galerkin and Carleman methods. In the third part we add the term K(x, y, %, tj) u (£, t|) dÇ dTj to the equation (1.1) and examined the solution of the new boundary value problem as in the second part. After this we obtained some results similar to the second part. In part four, we examined the mixed problem related with the equation (1.1 ). In part five, we examined the inverse problem of finding the pair of ( u, f ) related with the equation Lu = x f ( x, 'y ). In the last part, which is the sixth part, we examined the solution of Cauchy problem related with the equation of Lu = x f ( x, 'y ). After that we add the condition of u| = u 2 to the Cauchy problem examined the inverse problem of finding ( u, f ) pair. Key Words : Potential theory, elliptic type equation, inverse problem, mixed problem generalized function, Galerkin method.Bu çalışma altı bölümden oluşmaktadır. Birinci bölüm olan giriş bölümü, diğer bölümlerde incelenen problemlerin anlaşılmasına yardımcı olacak şekilde düzenlenmiştir. ikinci bölümde belirli bir D bölgesinin sınırının bir kısmında çözüm verildiğinde bu bölgenin içinde ( 1. 1 ) denklemi ile ilgili problemin çözümünün bulunması incelenmiştir. Problemin çözümünün varlığı, tekliği ve kararlılığı belirli uzaylarda incelenmiştir. Bu incelemelerde kullanılan yöntemler ön değerlendirmeler, Galerkin ve Carieman metodlarıdır. Üçüncü bölümde (1.1) denklemine K(x, y, £, r\) u (£, ti) d| dTj integral ifadesi ekle- nerek meydana gelen denklem için 2. bölümde olduğu gibi problem incelenip benzer sonuçlar elde edilmiştir. Dördüncü bölümde karışık problem incelenmiştir. Beşinci bölümde Lu s xf(x, *y) denkleminde belirli şartlar verildiğinde ( u, f ) çiftinin bulunması ters problemi incelenmiştir. Son bölüm olan, altıncı bölümde verilen Cauchy problemine u| _ = u2 şartı eklenerek ( u, f ) çiftinin bulunması ile ilgili ters problem incelenmiştir.ANAHTAR KELİMELER : Potansiyel teori, eliptik tip diferensiyel denklem, ters problem, karışık problem, genelleştirilmiş fonksiyon, Galerkin metodu
Role of the Mammalian Target of Rapamycin Pathway in Liver Cancer: From Molecular Genetics to Targeted Therapies
No full textPrimary liver cancers, including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA), are highly lethal tumors, with high worldwide frequency and few effective treatment options. The mammalian target of rapamycin (mTOR) complex is a central regulator of cell growth and metabolism that integrates inputs from amino acids, nutrients, and extracellular signals. The mTOR protein is incorporated into two distinct complexes: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Specifically, mTORC1 regulates protein synthesis, glucose and lipid metabolism, and autophagy, whereas mTORC2 promotes liver tumorigenesis through modulating the adenine/cytosine/guanine family of serine/threonine kinases, especially the protein kinase B proteins. In human HCC and iCCA samples, genomics analyses have revealed the frequent deregulation of the mTOR complexes. Both in vitro and in vivo studies have demonstrated the key role of mTORC1 and mTORC2 in liver-tumor development and progression. The first-generation mTOR inhibitors have been evaluated for effectiveness in liver-tumor treatment and have provided unsatisfactory results. Current research efforts are devoted to generating more efficacious mTOR inhibitors and identifying biomarkers for patient selection as well as for combination therapies. Here, we provide a comprehensive review of the mechanisms leading to a deregulated mTOR signaling cascade in liver cancers, the mechanisms whereby the mTOR pathway contributes to HCC and iCCA molecular pathogenesis, the therapeutic strategies, and the challenges to effectively inhibit mTOR in liver-cancer treatment. Conclusion: Deregulated mTOR signaling significantly contributes to HCC and iCCA molecular pathogenesis. mTOR inhibitors, presumably administered in association with other drugs, might be effective against subsets of human liver tumors
The Mixed WKB-Full-Wave Approach and its Application to Lower Hybrid Wave Propagation and Absorption
No full textThe mixed WKB-full-wave approach for calculating the 2D mode structure in tokamak plasmas is further developed based on our previous work [A. Cardinali et al., Phys. Plasmas 10, 4199 (2003) and Z. X. Lu et al., Phys. Plasmas, 19, 042104 (2012)]. A new scheme for theoretical analysis and numerical implementation of the mixed WKB-full-wave approach is formulated, based on scale separation and asymptotic analysis, to investigate lower hybrid wave (LHW) propagation and absorption. As a novel method, its comparison with other approaches is discussed. Its application to LHW propagation in concentric circular tokamak plasmas using typical FTU discharge parameters, is also demonstrated.Physics, AppliedPhysics, Fluids & PlasmasEICPCI-S(ISTP)
Relations between x-ray timing features and spectral parameters of galactic black hole x-ray binaries
No full textWe present a study of correlations between spectral and timing parameters for a sample of black hole X-ray binary candidates. Data are taken from GX
339-4, H 1743-322, and XTE J1650-500, as the Rossi X-ray Timing Explorer
(RXTE) observed complete outbursts of these sources. In our study we investigate outbursts that happened before the end of 2009 to make use of the high-energy coverage of the HEXTE detector and select observations that
show a certain type of quasi-periodic oscillations (type-C QPOs). The spectral parameters are derived using the empirical convolution model simpl to model the Comptonized component of the emission together with a disc blackbody for the emission of the accretion disc. Additional spectral features, namely a reflection component, a high-energy cut-off, and excess emission at 6.4 keV, are taken into account. Our investigations confirm the known positive
correlation between photon index and centroid frequency of the QPOs and reveal an anti-correlation between the fraction of up-scattered photons and the QPO frequency. We show that both correlations behave as expected in the “sombrero”
geometry. Furthermore, we find that during outburst decay the correlation between photon index and QPO frequency follow a general track, independent of individual outbursts
Impact of metalloporphyrin-based porous coordination polymers on catalytic activities for the oxidation of alkylbenzene
No full textSeven metalloporphyrin-based porous coordination polymers: Feш (TZP)Poly (CP1), CoII (TZP)Poly (CP2), NiII (TZP)Poly (CP3), CuII (TZP)Poly (CP4), ZnII (TZP)Poly (CP5), MnII (TZP)Poly (CP6), PbII (TZP)Poly (CP7) (TZP = 5,10,15,20- tetrakis[4-(2,3,4,5-tetrazolylphenyl)] porphyrin) were prepared and characterized. CP1−CP7 are amorphous aggregation supported with lower crystallinity by scanning electron microscopy, Brunauer−Emmett−Teller and powder X-ray diffraction. These coordination polymers exhibit effective dye scavenging and catalytic activities toward the oxidation of alkylbenzene to ketones and can be reused by filtration with a slight decreasing of catalytic activities. Metal atoms metalloporphyrin polymers have a great influence on the catalytic activities of metalloporphyrin polymers
The use of lignin for sustainable asphalt pavements: A literature review
No full textNowadays, one of the most interests of modern society is to replace increasingly larger quantities of petroleum derived products, which is a non-renewable source progressively depleting, so promoting both environmental and economic benefits. In this context, the practice to employ renewable sources to replace part of the bituminous materials is an effective approach in pavement engineering. Among different biomasses which are recognized as possible sources mixable with bitumen, lignin can represent a valid material. Lignin is a naturalresource commonly deriving from the by-product of the production of pulp and paper industry. It is the secondbmost common biopolymer on Earth and represents a potentially attractive alternative as partial substitute ofbbitumen. However, in order to understand the environmental and technical feasibility of the application of lignin in bituminous pavement applications, a multi-scale approach must be adopted. For this purpose, the paper aims at providing an overview of the use of lignin as renewable source in bituminous binders and mixtures, byinvestigating chemical, rheological and mechanical properties of lignin modified asphalt materials. Moreover, based on the available literature, field application experiences and Life Cycle Assessment (LCA) analysis are also discussed
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